摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMISTRYANNUAL REPORTSH. BASSETT, D.Sc., Ph.D.G. M. BENNETT, M.A., Ph.D.H. V. A. BRISCOE, D.Sc.H. M. DAWSON, D.Sc., Ph.D.Y.G. DONNAN, C.B.E., LL.D., F.R.S.A. C. G. EoERToN,M.A., F.R.S.J. J. Fox, O.B.E., D.Sc.C. S. GIBSON, O.B.E., M.A.A. J. GREENAWAY, F.I.O.W. N. HAWORTH, D.Sc., F.R.S.T. A. HENRY, D.Sc.J. T. HEwITr, D.Sc., F.K.S.C. N. HINSHELWOOD, M.A., F.R.S.C. K. INGOLD, D.Sc., F.R.S.ON THEJ. KENYON, D.Sc.H. KIRO, D.Sc.W. H. MILLS, Sc.D., F.R.S.T. S. MOORE, M.A., B.Sc.J. 0. PHILIP, O.B.N., D.Sc., F.R.S.T. 8. PRICE, O.B.E., D.Sc., F.R.S.F. L. PYMAN, D.Sc., F.R.S.E. K. RIDEAL, M.A., D.Sc., F.R.S.R. ROBINSON, D.Sc., F.R.S.J. L. SIMONSEN, D.Sc.5. SMILES, O.B.E., D.Sc., F.R.S.S. SUGDEN, D.Sc.J.F. THORPE, C.B.E., D.Sc., F.R.S.PROGRESS OF CHEMISTRYH. BASSETT, D.Sc., Ph.D., D.-&s-Sc.G. M. BENNETT, M.A., Ph.D.A. W. CHAPMAN, D.Sc.A. C. CHIBNALL, Sc.D.B. A. ELLIS, M.A.E. H. FARMER, D.Sc.J. J. Fox, O.B.E., D.Sc.0. GATTY, B.A.A. F. HALLIMOND, M.A.F 0 13(Sir) H. HARTLEY, M.C., C.B.E., M.A.,C. N. HINSHELWOOD, M.A., F.R.S.W. A. MACFARLANE, B.A.D. M. MURRAY-RUST, M.A.S. G. P. PLANT, D.Phil., M.A.J. PRYDE, M.Sc.A. S. RUSSELL, N.G, X A . , D.f%F.R.S.1930.ISSUED BY THE CHEMICAL SOCIETY@bitor :CLARENCE SMITH, D.Sc.3saiatattt aFbitor :A. D. MITCHELL, D.Sc.V O l . XXVII.L O N D O N :T H E C H E M I C A L S O C I E T Y1931PRINTED IN GREAT BRITAIN BYRlCUARD CLAY & SONS, LIMITED.BUNQAY, SUFFOLKCONTENTS.PAGEGENERAL AND PHYSICAL CHEMISTRY.By C. N. HINSRELWOOD,M.A., F.R.S. . . . . . . . . . . 11INORQANIC CHEMISTRY. By H. BASSETT, D.Sc., Ph.D. . . 52ORGANIC CHEMISTRY 1-Part I.-ALIPHATIC DIVISION. By E. H. FARMER, D.Sc. . . 82A. W. CHAPMAN, D.Sc. . . . . . . . . 114171Part II.-HOYOCYCLIC DIVISION.Part III.-HETEROCYCLIC DrvIsroN.By G. M. BENNETT, M.A., Ph.D., andBy S. G. P. PLANT, M.A., D.Phi1.By J. J. Fox, O.B.E., D.Sc., and B. A. ANALYTICAL CHEMISTRY.ELLIS, M.A. . . . . . . . . . . 203BIOCHEMISTRY. By A. C. CHIBNALL, Sc.D., and J. PKYDE, M.Sc. . 229GEOCHEMISTRY. By A. F. HALLIMOND, M.A. . . . . . 283RADIOACTIVITY AND SUB-ATOMIC PHENOMENA (1929-30). RyA. S. RUSSELL, M.C., M.A., D.Sc. . . . . . . 305ELECTRICAL CONDUCTIVITY OF SOLUTIONS.By (Sir) H.HARTLEY, &r.c., c.B.E., M.A., F.R.s., 0. GATTY, B.A., w. A.MACFARLANE, B.A., and D. M. MURRAY-RUST, M.A. . . . 32TABLE OF ABBREVIATIONS EMPLOYED I N THEREFERENCES.Abbreviated Title. FULL TITLE.A. . . . . . Abstracts in Journal of the Chemical Society (until1925) or in British Chemical Abstracts,’ Section A.Abs. Theses Univ. Chicago Abstracts of Theses, University of Chicago (ScienceAmer. Inst. Net. Eng. Tech. American Institute o f Mining and MetallurgicalAmer. J. Bot. . . . American Journal of Botany.Amer. J. Pharnz. . . American Journal of Pharmacy.Amer. J. Physwl. . . American Journal o f Physiology.Amer. J. Sci. . . . American Journal of Science.Amer. Xin. . . . Atnerican Mineralogist.Amer.Rev. Tuberculosis . American Review of Tuberculosis.Anal. Asoc. Quiina. AygentinaAnal. Bs. Quim . . Anales de la Sociedad Espan6la Fisica y Quimica.Analyst . , . . The Analyst.Annalen . . . . Justus Liebig’s Annalen der Chemie.Ann. Acad. Brasil. Sci.Ann. App?. Bot. . . Annals of Applied Botany.Ann. Bot. . . . . Annals o f Botany.Ann. Chim. . . . Annales de Chimie.Ann. Chim. Appl. . . Annali di Chimica Applicata.Ann. Inst. Anal. Phys. Annales de l’hstitute d’Analyse physico-chimique,Ann. Inst. Platine . . Annales de 1’Institut de Platine et des adtres MQtauxAnn. Physik . . . Annalen der Physik.Ann. Reports . . . Annual Reports of the Chemical Society.Apoth.-Ztg. . . . Apotheker-Zeitung.Arch. Eisenhiittenw. . . Archiv fur das Eisenhiittenwesen.Arch.ges. Physiol. . . Archiv fur die gesamte Physiologie des MenschenArch. Phurm. . . , Archiv der Pharmazie.Arch. Physique biol. , . Archives de Physique biologique.Arch.Sci. Biol. St. PeterslurgArch. Sci. phys. nut. . .Arhiv Hemiju . . . Arhiv za Hemijn i Farmaciju.Arkiv Kemi, Min., Geal. .Arp. Seminario Est. GalegosAstrophys. J. . . . Astrophysical Journal.Atti R. A c d . Lincei . . Atti (Kendiconti, Memorie) della Reale AccademiaNazionale dei Lincei, classe di scienze fisiche,matematiche e naturali, Roma.B. . . . . , British Cheniical Abstracts,* Section B.Bcin. Koh. Lapok . . Bdnytiszati ks Kohiszati Lapok.Rer. . . . . , Berichte der deutschen Chemischen Gesellschaft.Uiochem. J. . . . The Biochemical Journal.Biochcm.2. . . . Biochemische Zeitschrift.BioL Keviews . . . Biological Reviews.Brennstof.-Chem. . . Brennstoff-Chemie.Bul. SOC. Chim. Bomdnia ,Bull. Acad. Polonaise .Bull. Acad. roy. Bclg. .BdI. Acad. Sci. Roumaine .Bull. A d . Sci. Leningrad.Bull. Acad. Sci. U.S.S.R. .Bull. Chem. SOC. Japan .(Sci. Ser.) . . . Series).Pub. . . . . Engineers Technical Publications.Anales de la Asociacion Quimica Argentina.. Annals da Academia Brasileira de Sciencias.Chem. . . . . Leningrad.prikieux.und der Tiere (Pfliigers Archives).Archives des Sciences biologiqnes, St. Petersburg.Archives des Sciences physiques e t naturelles.Arkiv €3- Iiemi, Mineralogi och Geologi.Arquiros do Srminario d’Estudos Galegos.Buletinul Societgtei de Chimie din Romania.Bulletin Internationale de 1’ Acaddmie Polonaise desAcademie royale de Be1gique.-Bulletin de la ClasseBulletin de la Section Scientifique de l’Acad6mieBulletin de 1’AcadP;mie des Sciences, Leningrad.Bulletin de 1’Acadkmie des Sciences de 1’Union desBulletin of the Chemical Society of Japan.sciences et des Lettres.des Sciences.Roumaine.Rkpubliques SoviBtiques Socialistes.The year is not inserted in references t o 1930viii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.Abbreviated Title.Bull.Inst. Phys. Chem. Res.Tokyo . . . .Bull. SOC. chim. . .Bull. Soc. chim.Belg. ,Bull. Soc. Chim. 6401. .Bull. Soc.franq. illin. .Bull. Xoc. Pham. Bor-deaux . . . .Bull. U.S. Geol. SzLrvey .Bull. U.S. Nat. Museum .Bull.Wagner Inst. Sci. .Bur. Stand. J. Rcs. . .Canadian J. Bes. . .Centr. illin. . . .Chem. and Ind. . . .Chem. Erde . . .Chem. Listy . . .Chem. News . . .Chem. Reviews . . .Chem. Weekblad . .Chem. Zentr. . , .Chem.-Ztg. . . ,C‘ompt. rend. . . .Compt. rend. 90c. Bid. .Econ. Geol. . . .Gazzetta . . . .Gwrit. Chim. Ind. App2. .Helv. Chim. Acta . .Helv. Phys. Acta . .Ind. Eng. Chenz.. . .Ind. Eng. Chenz. (Aval.) .J . . . . . .J. Agric. Ees. . . .J. Amer. Chcm. SOC. . ,J. Amer. Med. Assoc. . .J . Amer. Pharm. Assoc. .J. Appl. Chem. Russia .J. Assoc. Of. Agric. CZieni. .J. Bact. . . . .J. Biol. Chem . . .J, Chem, Ind. Russia. .J. Chim. physique . .J. Czech. Chem. Cmm. .J. Dept. Agric. Kyushw .J. Elisha d.litchee2l Sci.SOC.J. Franklin Inst. . .J. Gen. Physiol. . . .J . Geol. . . . .J. Indian Chem. SOC. . .J. Indian Inst. Sci. . .J. Inst. MetaL . . .J. Marine Biol, Assoc. .PULL TITLE.Bulletin of the Institute of Physical and ChemicalBulletin de la Sociktd chimique de France.Bulletin de la Sociktd chimique de Belgique.Bulletin de la Socidtd de Chimie biologique.Rulletin de la SociBtB franqaise de Mineralogie.Bulletin des Travaux de la Sociktti de Yharmacie deI3ulletin of the United States Geological Survey.Rulletin of the United States National Museum.Bulletin of the Wagner Free Institute of Science ofBureau of Standards Journal of Research.Canadian Journal of Research.Centralblatt fur Mineralogie, Geologie, und Palaon-Chemistry and Industry.Chemie der Erde.Chemickd Listy pro VGdu a PrBmysl.Organ de la‘‘ Ceskk chemickb Spoleitnost pro VBdu aPrfiniysl. ”Chemical News.Chemical Reviews.Chemisch Weekblad.Chemisches Zentralblatt.Chemiker-Zeitung.Comptes rendus hebdomadaires des SOances de1’Acaddmie des Sciences.Comptes rendiis hebdomadaires de SBances de laSociBtd de Biology.Economic Geology.Gazzetta chimica italiana.Giornnle di Chimica Industrinle ed Applicata.Helvetica Chimica Acta.Helvetica Physica Acta.Industrial and Engineering Chemistry.Industrial and Engineering Chemistry : AnalyticalJournal of the Chemical Society.Journal of Agricultural Research.Journal of the Anierican Chemical Society.Journal of the American Medical Association.Journal of the American Pharmaceutical Association.Zhurnal prikladnoi Chimii.Journal of the Association of Official AgriculturalJournal of Bacteriology, Baltimore.Journal of Biological Chemistry.Journal of Chemical Industry of Russia.Journal de Chimie physique.Journal of Czechoslovak Chemical Coinniunications.Journal of the Department of Agriculture, liyushuImperial University.Journal of the Elisha Mitchell Scientific Society.Journal of the Franklin Institute.Journal of General Physiology..Journal of Geology.Quarterly Journal of the Indian Chemical Society.Journd of the Indian Institute of Science.Journal of the Institnte of Metals.Journal of the Marine Biological Association of theResearch, Tokyo.Bordeaux.Philadelphia.tologie.Edition.Chemists.United KingdomTABLE OF ABBREVIATIONS EMPLOYED IN TIIE REFERENCES.ixAbbreviated Title.S. Phamn. Chim. . .J. Pharm. SOC. Japan. .J. Phys. Radium . .S. Physical Chern. . J. pr. Chm. .J . Roy. Tech. CoEl. GiasgodJ. Buss. Phys. Chem. Soc. .J . Soc. Chem. Ind. . .J. Soc. Chem. 2nd. Japan .J. Soc. G2ass Tech. . .S. Washington Acad. Sci. .Jahrb. Min., BeiL-Bd. .X. Samka Vetenskapsal.Eandl. . . .Xgl. Danske bidenskabs.Selsk. Math.-phys. Med. .golloidcicam. Beih.. . .Kolloid- Z. . . .Mem. Coll. Sci. Kyoto. .Mikrochem. . . .Min. Mag. . . . .illilt. Lebensm. Eyg. . .Mmtsh. . . . .1V.J. Agric. Exp. Sta. B d l .Nach. Ges. Wiss. Gottingen.Naturwiss. . . .N'uumoetensch. Tijds. .New Phyt. .. .Nuovo Cim. . . .Oesterr. Chem.-Ztg. . ,PJiiqers Arch. . . .Phamn. Weekblad , .PJtaTm. Zentr. . . .Pham.-Ztg. . . .Phil. Mag. . . .Phil. Trana. . . .Philip?rine J . Sci. . .PhysicclRev. . . .Phyrikal. Z. . . ,Plant Physwl. . , .Planta . . . .Proc. Acad. Sci. AinsterdarnProc. Biochem. SOC. . .Proc. Camb. Phil. Soc. .Proc. K. Akad. Wetensch.Proc. Imp. Acad. Tokyo .A ntsterdmrFULL TITLE.Jounial de Pharmacie et de Chimie.Jounial of the Pharmaceutical Society of Japan,Journal de Physique e t le Radium.Journal of Physical Chemistry.Journal fur praktische Chemie.Journal of the Royal Technical College (Glasgow).Journal of the Physical and Chemical Society of(Yakugakuzasshi) .Russia.Journal of the Societv of Chemical Xndustrv.Journal of the Sociecy of Chemical Indusiry, Japan.Journal of the Society of Glass Technology.Journal of the Washington Acadenly of Sciences.Neues Jahrbuch fur Mineralogie, Geologie undKongliga Svenska Vetenskaps Akadeiniens Hand-Kongelige Danske Videnskabernes Selskab, Msthe-Kolloidchemische Beihefte.Kolloid-Zeitschrift.Memoirs of the College of Science, Kyoto ImperialUniversity .Mikrochemie.Mineralogical Magazine and Journal of the Minera-logical Society.Mitteilungen aus dem Gebiete der Lebensmittelunter-auchung und Hygiene.Monatshefte fk Chemie und verwandte Theile andererWissenschaften.(K6gy6 Kwagaku Zasshi.)Paliiontologie, Beilage-Band.lingar.matisk-fysiske Meddelelser.New Jersey Agricultural Experimental StationsBulletin.Nachrichten von der Gesellschaft der Wissenschaftenzu Gottingen.Die Naturwissenschaften.Natuurwetenschappelijk Tijdschrift.New PEytologist.I1 Nuovo Cimento.Oesterreichische Chemiker-Zeitung.Archiv fiir die gesam te Pliysiologie des Menschenund der Tiere.Pharmaceutich Weekblad.Pharmazeutische Zentralhalle.Pharmazeutische Zeitung.Philosophical Magazine (The London, Edinburgh andDublin).Philosophical Transactions of the Royal Society ofLondon.Philippine Journal of Science.Physical Review.Physikalische Zeitschrift.Plant Ph yaiol ogy .Zeitschrift fur wissenachaftliche Biologie. AbteilungE.Planta. Archiv fur wissenschaftliche Botanik.Proceedings of the Royal Academy of Sciences ofAmsterdam (English Version).Chemistry and Industry (Proceedings of BiochemiealSociety).Proceedings of the Cambridge Philosophical Society.Proceedings of the Imperial Academy of Japan.Koninklijke Akademie van Wetenschappen te Amster-dam.Proceedings (English version).AX TABLE OP ABBREVIATIONS EMPLOYED IN THE REFERENCES.Abbreviated Title.Proc. Leeds Phil. Xoc. .Proc. Nat. Acad. Sci. , .Proc. NoGa Xcotia Inst. Sci.Proc. PhysicalSoe. . .Proc. Roy. SOC. . . .Proc. U.S. Nat. Musewm .Proc. Univ. Durham Phil.SOC. . . . .Przemyst Chem. . . .Quart. J. CeoE. SOC. . .Quim.eJnd. . . .IZec. trav. chim. . . .Rev. g h . Colloid. . .Rev. Sci. Instr. . . .Rocz. Chem. . . .815. Papers Inst. Phys.Chem. Res. Tokyo . .SG~. Rep. T6hoku Imp. Univ.Semanamkd.. . .Xitzu?Lgsber. Akad. Wiss.Wien. . . . .Xitzungsber. Preuss. Akad.Wiss. Berlin . . .SuomenKem. . . .Svemk Farm. Tidskr. .S'censk Kem. Tidskr. . .Tidsskr. Kjemi Berg. . .Trans. Amer. Electrochem.SOC. . . . .Trans. Canad. Inst. Nin.Met. . . . .Trans. Ceramic Soc. . .Trans. Faraday SOC, . .Trans. Roy. 9oc. Canada .Tsch. Xin. Petr. Mitt. .Ukraine Chm. J, . .[J.S. Bur. Stand. Res. PaperVerh. Geol. Bundesanst.Wien . . . .Vers. K. Akad. Amster-dam . . . .Wiss. Verof. Siemens-Konx.2. anal. Chem. .2. angew. Chem..2. anorg. Chem. ,2. Elektrochem. .2. Oeophys. .2. Krist. . .2. Metullk. . .2. PJanz. Dung.Z. Physik . .2. physikal. C h m .* . . . . .. .. .. . . . . . . . . .2. physiol. c'hem.. .Z. tech. Physik. . . .2. Vcr. deut. Zucker-I.?id. .FULL TITLE.Proceedings of the Leeds Pldosophical and LiteraryProceedings of the National Academy of Sciences.Proceedings of the Nova Scotia Institute of Science.Proceedings of the Physical Society of London.Proceedings of the Royal Society.Proceedings of the Uni tcd States National Museum.Proceedings of the University of Durliani I'hilo-sophical Society.Przemysf Chemiczny.Quarterly Journal of the Geological Society.Quimica e Industria.Recneil des travaux chimiques des Pays-Rss et de laRevue gherale des Colloi'des.Review of Scientific Instruments.Roczniki Chemji organ Polskiego TowarzystwaChemicznego.Scientific Papers of the Tnstitute of Physical andChemical Research, Tokyo.Science Reports, Tahoku Imperial University.La Semsna medica (Bnenos Aires).Sitzungsberichte der Akademie der Wissenschaften,Sitzungsberichte der Preussischen Akademie derSuomen Kemistilehti Acta Chetnica Fennica.Svensk Farmaceutisk Tidskrift.Svensk Kemisk Tidskrift.Tidsskrift for Kemi og Bergvaesen.Transactions of the American ElectrochemicalSociety,Transactions of the Canadian Institute of Miningand Metallurgy and of the Minirig Society ofNova Scotia.Society (Scientific Section).Belgique.Wien.Wissenschaftcn zu Berlin.Transactions of the Ceramic Society.Transactions of the Faraday Society.Transactions of the Royal Society of Canada.Tschermaks minerologische und petrogrsphischeUkraine Chemical Journal.Research Papers of tlie U.S.Bnreau of Standarda.Verhandlungen der Ueologischen Bundessnstalt,Verslag Koninklijke Akademie Wetenschappen teWissenschaftliche Veroffentlichungen ails demZeitschrift fur analytische Chemie.Zeitschrift fur angewandte Chernie.Zeitschrift fur anorganische und allgemeine Chemie.Zeitschrift fiir Elektrochemie.Zeitschrift fur Geophysik.Zeitschrift fur Kristallographie.Zeitschrift fur Metallkunde.Zeitschrift fur Pflanzenorniihrung und Dungung.Zeitschrift fur Physik.Zeitschrift fur physikalische Chemie, Stijchioinetrieund Verwandtschaftslehre.Hoppe-Seyler's Zeitschrift fur ph ysiologische Cheniie.Zeitschrift fur technische Pliysik.Zeitschrift des Vereinsder deutschen Zucker-Indnstrie.Mitteilungen.Wien.Amsterdam.Siemens- Konzern

ISSN:0365-6217    

DOI:10.1039/AR9302700001

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMTSTRI'.GENERAL AND PHYSICAL CHEMISTRY.BY necessity, and by the sanction of custom, this Report is confinedto the discussion of a few matters, and can only hope to reflect somcof the dominant motives. One of these has been the interpretationof old-established chemical ideas in terms of the physics of thequantum theory. Although some of the physical theories havetheir limitations, and could perhaps never have been constructcdunless the chemical facts had already been well understood,their introduction has been not only fruitful but illuminating.No excuse, therefore, is made for the space devoted to them in theReport : but an attempt has been made t o show where they arepurely formal or even arbitrary, and where they contribute qualita-tively new ideas.The chances of success of such an attempt arenot great, but it is one which ought to be made. Another matterto which intensive study has recently been devoted is the elucidationof so-called elementary processes, by which is meant the atomicand molecular mechanisms of chemical changes : this aspect hasbeen rather fully represented in the following pages.Regret must be expressed a t the unavoidable omission ofreference to systematic thermodynamics, to the analysis of inorganiccrystal structures, to new methods of measurement, to the chemistryof the photographic process-on all of which matters valuablepapers have been published-and, especially, to many examplesillustrating themes which have been discussed too recently in theseReports to be profitably re-opened a t the present moment.The Quantum Mechanical Treatment of Chemical Forces.During the last few years the wave mechanical and quantummechanical theories of the electron, the atom, and the interactionbetween atoms have caused a profound change in physical ideas.It is not an inappropriate moment to consider what correspondin12 HINSHELWOOD :modifications in our views about fundamental problems of chemistryhave resulted from or accompanied these new physical conceptions.I n the first place, it must be said that the electron and the atomdo not a t all cease to play their traditional chemical r6les as definiteand essentially discrete entities.It is true that a beam of electronscan be diffracted in a manner analogous to a train of waves of wave-length h/mv, mv being the momentum of one of the electrons.Severalfurther convincing demonstrations of this have been forthcomingsince the last Report : indeed A. Dauvillier describes a method bywhich the diffraction of an electron beam by a film of microcrystallinezinc oxide can be rendered visible, and the de Broglie wave-lengthrelation demonstrated by changing the speed of the electrons.Not only electrons, but protons and atoms appear to be capableof diffraction. I. Estermann and 0. Stern,2 following up work byF. Knauer and Stern: have shown that, when a ray of heliumatoms or hydrogen molecules is incident on a cleavage face of lithiumfluoride, the intensity of the rays scattered in different directionscorresponds exactly to the diffraction of waves by a grating.Ifthe distance apart of two like ions in the crystal is taken as thegrating constant, the wave-length can be calculated. It is foundto vary with the speed and mass of the particles in accordancc withthe de Broglie equation A = h/mv. Investigations on the reflexionof hydrogen atoms from crystals have been made by A. J. Dempsterand T. H. Johnson.5 A summary of all diffraction experiments isgiven by S. Kikuchi.6But the most satisfactory interpretation of these phenomenaseems to be a statistical one, the relative amplitude of a wavefunction a t any point expressing the relative numbers of scatteredelectrons or atoms which occur in a small volume element in theneighbourhood of that point.* The €act that the probability ofscattering in a given direction varies in a wave-like manner is, ofcourse, a new truth of fundamental importance, but from thechemical point of view it is better to regard the wave-like characterof electrons and protons as something determining where they willgo rather than as describing what they are.Applied to systems more complex than a single electron or proton,Nuture, 1930, 125, 50; A., 129.2.Phyeik, 1930, 61, 95; A., 515.Ibid., 1929, 53, 779; A , , 1929, 490.Nature, 1930, 125, 51, 741; A., 129, 835.Physical Rev., 1928, [ii], 31, 1122; A . , 1929, 1.358; J . PrunElin Inat.,Physikul. Z., 1930, 31, 777.1029, 207, 629, 639; A., 1930, 514.* The analogous synthesis of the undulatory and quantum characters oflight is also becoming a cornrnonplace of physics13 GENEEAL AND PHYSICAL CHEMISTBY.wave mechanics (and equally Heisenberg’s quantum mechanics)is in the first instance a formal calculus for expressillg the olderquantum laws in a more convenient, more correct, and muchcompleter way than was possible before.The older laws restrictedthe possible values for the energy of a system by the arbitraryintroduction of whole-number relationships : the new methodderives the whole numbers in another way. It asserts that thepossible states of a system are determined by a function, usuallydenoted by $, which does not represent anything directly perceptibleor measurable, but which satisfies an equation for the propagationof waves.Certain of the mathematical prescriptions involved inthe calculations, e.g., the method of “ normalisation ” (or the com-mutation rule in Heisenberg’s mechanics), are not rules which suggestthemselves naturally to physical intuition, but are directly designedto retain the Bohr and Planck relations (A23 = hv). Moreover,the fact that in complex systems the ‘‘ waves ” are propagated inas many dimensions as there are co-ordinates, shows that we aredealing with something without so-called physical reality : thusit is necessary to be clear about the fact that the waves do notsubstitute a new physical picturc for the older pictures used inchemistry. But the important fact is this : the behaviour of systemsis determined or described by a function which has the character ofa wave function, and, in particular, which vibrates with a frequencyequal to E/h, where E is the energy of the system in the state con-sidered.Schrodinger’s wave equation isE is the total energy, and U is the potential energy.The point of the new mathematical formulation lies in the factthat the wave equation has solutions only for certain definite valuesof the energy (proper values or characteristic values) which representthe energy levels of the quantum theory.Now, although primarily a device for specifying possible energystates, and the conditions of transition from one to another, ratherthan a new physical theory, Schrodinger’s function, vibrating withfrequency E/h, confers certain qualitative characters upon molecularsystems which were not accounted for by older theories.* The mostimportant of these is the possibility of what is known as quantum7 Compare, c.g., Bloch, “ L’Anciennc et la Nouvelle Th6orie des Quanta,”Paris, 1930.* Heisenberg’s mechanics, although formally different in its postulates, isequivalent to Schrodinger’s, and operates with vibrating q~ant~ities its itsfundamental magnitudes14 HINSHELWOOD :mcchanical resonance, which has led to an interpretation of theforces involved in chemical combination.8The possible energy states of thetwo isolated atoms are naturally identical, and are determinedby the solution of a $-equation containing the potential energy ofone atom; $ vibrates with frequency v = E/h.Now if the twohydrogen atoms are interacting with one another they must bctreated as one system, the total potential energy which is insertedin the equation being modified by the electrostatic forces.Sincethe frequencies associated with the two separate atoms are identical,a phenomenon exactly analogous to resonance occurs, and insteadof the joint system being associated with the same frequency as thetwo isolated atoms, v assumes two values v 4 v', a well-knowneffect of resonance.* Since E = hv, there are two solutions to thewave equation expressing the possible states of a pair of hydrogenatoms, the corresponding energies being E6 + e and E,, - e, where,To is the value for two atoms, not exerting any action on each other.If , for some assigned distance apart of the two atoms, the joint systemhas a smaller energy than the separate atoms, union to a moleculetczkcs place.However, the quantum theory by itself gives no reasonto prefer the solution with smaller energy to that with larger energycorresponding to a repulsion between the atoms. Further progressdepends upon the application of the Pauli principle. This principle inConsider two hydrogen atoms.8 W. I-leitler and F. London, 2. Physik, 1927, 44, 455; d., 1927, 023;3'. London, ibid., 1928, 46, 455; A., 1928, 344; W. Heitler, Physikal. Z . ,1'930, 31, 185; A., 525; F. London, Naturwiss., 1930,17, 516.* This phenomenon is so essential to the theory that, although it is an oldolio, there may be some utility in explaining it briefly here.Suppose, forexample, we have two equal pendulums in resonance. I f they were not inresonance, their motions could be represented by the equations, - d2X/dt2 =a%, and - dZy/dtz = a2y, x and y being the respective displacements and a aconstant. Whenthey are in resonance each transmits a certain force to the other, and its ownmotion is modified by the reaction. The equations become - d2x/dt2'=a2x: + b2y and - dzyy/dtz = a2y + b2x. I f we write x = Asinpt and y =R sin (pt 4- E ) , substitute in the differential equations, and solve for p , wofind two values : one of these gives a frequency greater than the undisturbedfrequency, a / 2 ~ , and the other gives a smaller frequency. The correspondingvalues of E are 0 and T. If the phases of the two pendulums are identical orexactly opposed the pendulums vibrate jointly with the one or the otherpermissible frequency.For any other relation of the phases, both frequenciesco-exist and give rise to beats in such a way that when the amplitude of onependulum is a maximum that of the other is zero. The energy flows back-wards and forwards from one to the other in a remarkable manner as mayeasily be shown experimentally. (Something analogous to this is what thequantum physicists mean, when they talk about an " exchange " of electronsbetween two atoms.)When they are isolated the frequency of each is a / 2 ~ GENERAL AND PHYSICAL CHEMISTRY. 15its earlier form stated that no two electrons in a molecule can have allfour quantum numbers the same, and it has a strong empirical found-ation in the facts of spectroscopy.I n terms of wave mechanics itasserts that all states of a molecule are excluded of which the Schro-dinger functions depend upon several electrons (or protons) in thesame way. For example, in the present problem the two solutionscorrespond, roughly speaking, to vibrations in the same phase (sym-metrical) and in phases differing by x (antisymmetrical). The sym-metrical solution is the one which can give combination ; but it wouldbe forbidden by the Pauli principle unless the two electrons concernedcould differ in some other respect from one another. They can,however, have opposite spins. Two hydrogen atoms with oppositelyspinning electrons can unite to a molecule : two with parallel spinsrepel each other.Thus the chemical bond appears as a pair ofelectrons with opposite spins. Since only two directions of spin arepossible, the saturation of chemical valencies receives an interpreta-tion.Theperturbation of t j by the mutual interaction of the two atoms is whatcauses the splitting of the possible energy levels into two sets, thelower of which is permitted by the Pauli principle when the electronshave opposite spins. Since this perturbation is the greater thenearer the atoms approach, the energy is smaller, ie., the attractiongreater. But eventually nuclear repulsion predominates and thusthe total energy passes through a minimum for a certain nucleardistance. This is the equilibrium position of the two atoms in themolecule. It need hardly be said that the actual calculation isalmost impossible except in very simple or idealised examples.A systematic investigation of the symmetry relationships of atomswith different numbers of electrons in quantum mechanicalresonance, in conjunction with the Pauli principle, gives most of theknown facts about chemical valency in a qualitatively correctmanner.9 The 1, 3, 5, 7 valencies of the halogens, and the 2, 4, 6valencies of the oxygen group, and the restriction of the valenciesof fluorine to one are, for example, explained.It must not beforgotten that the restriction of the possibility of combination tothose cases which are in accordance with the rules of chemicalvalency depends entirely on the application of Pauli’s principle andis not contained in the quantum mechanical equations.The prin-ciple itself is in one sense just as empirical and not much morefundamental than the rules of valency which chemistry had alreadyestablished. But the great advance is that the facts of chemistryare brought into striking relation with those of spectroscopy. TheThe stability of molecules can in principle be investigated.Compare ref. 8; also M. Born, 2. Physik, 1930, 64, 72916 HINYHELWOOD :connexion is crystallised in the statement that the chemical valencyis one less than the spectral multiplicity.Two atoms which could not combine in their normal state maycombine in unexpected ways if one of them is optically excited,since the excitation changes the quantum numbers and thus maydestroy a symmetry which in the unexcited state led to chemicalsaturation.This explains certain spectra attributable to otherwiseunknown compounds.Quantum mechanical resonance is important in several otherways. The splitting of a single frequency into two explains thetwo non-combining spectral series of helium (ortho- and para-helium)and other similar spectroscopic facts. It is also possible that reson-ance effects have something to do with the occasional transferenceof energy between atoms and molecules at distances considerablygreater than the " collision " diameter of the kinetic theory. Forexample, the quenching of fluorescence of gases by other gasesappears occasionally to be so strong that there would not have beentime for normal collisions during the life of the optically excitedatom or molecule : this is expressed by saying that the deactivatingcollisions occur with a large '' collision area." l oThe chemical forces which were referred to above were naturallyof the so-called homopolar kind.The treatment of the polar forcesacting between ions in lattices is less characteristically quantummechanical and will not bc discussed here. Reference should bemade, however, to the work of J. E. Lennard-Jones and his col-laborators, which has thrown much additional light on the propertiesof ionic lattices in recent years.ll The transition from non-polarto polar linking is discussed by Ilt. Samuel and L. Lorentz.llaR. Eisenschitz and F. London 12 have recently elaborated thequantum-mechanical treatment of the interaction of two atoms, insuch a way as to give the original theory of the homopolar bond as afirst approximation and to include a treatment of the so-called vander Waals forces.The two existing theories of these forces arethose of W. H. Keesom l3 and I?. Debye.14 The former is based onthe electrostatic action of rigid dipoles or quadrupoles, the latter10 L4nr~. Reports, 1927, 24, 327, ref. 50; W. P. Baxter, J. Amer. C'hetn. SOC.,1930, 52, 3920; H. Kallmann and F. London, Z. physikal. Chem, 1920, [B],2, 207; A., 1929, 487.11 Compare J. E. Lennard-Jones and (&Iiss) B. RI. Dent, Proc. Roy. SOC.,1928, [ A ] , 121, 247; A., 1929, 17.1 l a 2. Physik, 1929, 59, 53; A., 1930, 137.12 2.Physik, 1930, 60, 491; A., 625;l3 Physikal. Z., 1921, 22, 129.l4 Ibid., 1920, 21, 178; 1921, 22, 302; A , , 1920, ii, 356.F. London, ibid., 1930, 63, 246;A . , 1239GENEBAL AND PHYSICAL CHEMI’YT’RY. 17on the modification of existing dipoles by induction. In Keesom’sthcory, the force diminishes rapidly with increasing temperature,since with increasing velocity there is less time for orientation into theposition of attraction. I n Debye’s theory, there is a term inde-pendent of temperature. Both theories have to proceed in a semi-cinpirical manner and derive the electric moments from the knownvan der Wads forces : in particular, a quadrupole moment has tobe assumed for the inert gases, which is not consistent with thespherical symmetry which these gases possess in the wave-mechanicaltheory.pole moment which in Debye’s or Keesom’s theory would have ledto far too small a value of van der Waals’s constant a, Thcquantum-mechanical problem can only be treated in a very generalway but appears to give results of the right order of magnitudc :the principle is to take into account the mutual perturbations of theperiodic electronic motions.The chemical valency forces arcaccounted for by resonance and the Pauli principle, appear in thcfirst approximation, and have a very short range : the van derWaals forces appear when the equations are solved to the secoiidapproximation, and diminish with distance much less rapidly.Another method of calculation used by J. E. Lennard-Jones 13gives the right order of magnitude for the attraction between twohydrogen atoms and agrees with Eisenschitz and London.calculates the forces between a hydrogen atomand a helium atom and between two helium atoms. The distancebetween two atoms in liquid helium thus found is approxirnatclyright.From the chemical standpoint, one of the more interesting develop-ments of the theory is the attempt by E.Huckel l7 to ajccount forthe stability of the double bond to rotation. He begins withJ. E. Lennard- Jones’s electronic structure of the oxygenimagines then two hydrogen nuclei drawn out from the oxygen togive formddehyde, and then the process repeated to give ethylene :The wave-mechanical model of hydrogen gives a quadruG. GentileA discussion of the Schrodinger functions arid of tlic mutualpotential energies of the electric charges leads to the conclusionthat there is a minimum energy for a definite orientation of theatoms, ie., the “bond” possesses “rigidity.” If the two substituentsjoined to each carbon atom are different, there arc two stablel5 Proc.Roy. SOL, 1930, [ A ] , 129, 598.16 2. Physik, 1930, 63, 795; A., 1234.1 8 Trans. Paraday Xoc., 1929, 25, 668; A , , 1929, 1360.l7 Ibid., 1930, 60, 423; A., 52518 HINSHELWOOD :plane arrangements (cis and trans), though the two energy minimaassociated with them need not be equal. The energy which mustbe employed in causing a rotation about the ‘‘ double bond ” isconnected essentially with “ the mutual electrostatic action of theelectronic clouds of the valency electrons which bind the sub-stituents, and the cloud of the two electrons of the doublebond.” The former have their maxima in the planes of the sub-stituents, and the latter in the plane perpendicular to these.Theelectronic clouds interfere with one another more when rotationoccurs than in the plane configuration. (The picture thus presenteddepends on the earlier interpretation of Schrodinger’s equation,according to which electrons in orbits of low quantum number arereplaced by continuous clouds of electricity : the validity of Huckel’scalculations does not, of course, depend upon the admissibility ofthis picture, but if we wish to avail ourselves of such help as it offers,we must combine it with the statement that, although an electronis not a cloud of electricity, there are purposes for which it is con-venient to regard it as one.)Turning from the consideration of ‘‘ chcrnical ” forces to electro-static actions, it is interesting to note that a “ collision ” betweentwo similar particles, exerting Coulomb forces on each other, occursdifferently when classical laws are superseded by wave-mechanicallaws.For example, in collisions between a-particles and heliumnuclei the amount of scattering a t 45” calculated by wave mechanicsis twice that expected from classical theory, a result predicted byN. P. Mott,lQ and confirmed experimentally by J. Chadwick.20The Elementary Processes of Chemical Change.The discussion of chemical forces a t once raises the questions, onthe one hand, of the structure of molecules and of the more complexformations which they in turn build up, and on the other hand, of theelementary processes involved in the changing partnerships ofatoms which constitute chemical transformation.A number ofaspects of this second question will be dealt with in the presentsection.The heat of activation of a chemical reaction such as 2MI =H, + I, is less than the energy required to resolve all the linkagesin the reacting molecules, and thus allow the completely free atomsto rearrange themselves into the structure of maximum stability.Resolution into atoms sometimes occurs, especially in certainreactions of the halogens. Examples are referred to in a latersection.But this process must be regarded as the limiting calse ofProc. Roy. Soc., 1930, [ A ] , 126, 259; A . , 269.2o Ibid., 1930, [ A ] , 128, 114; A., 1085GENERAL AND PHYSICAL CHEMISTRY. 19the excitation of the vibrational degrees of freedom of the molecules,which is the general form of activation and only reaches the limitof dissociation in exceptional circumstances.The energy of activation of the reaction AB + CD = AC + BDrepresents the sum of the energies possessed by the molecules ABand CD at the point where their atoms are stretched apart justenough to be able to rearrange themselves readily. Its valuedepends, therefore, on the form of the curves which represent thepotential energies of the several molecules as a fiinction of therespective nuclear separations.20a Attempts to correlate the heatof activation with a known dissociation energy must thus, in general,be unsuccessful.H. Eyring 21 has suggested a rule for calculatingheats of activation in bimolecular reactions in terms of a tabulatedseries of ‘‘ heats of linkages.” There is too much uncertainty aboutthe heats of linkage themselves, and too little experimental materialto allow a really good test of the validity of the rule, but it is clearon general theoretical grounds that such a principle can neverprovide more than an empirically valuable approximation.D. S. Villars,22 following a more generalised discussion of R. M.Langer,23 approaches the matter in a more fundamental way byconsidering the reaction 2HI = H, + I, in relation to the potentialenergy curves of the molecules H,, I, and HI.A fairly good ideaof the variation in potential energy with the separation of the atomsin a diatomic molecule can be obtained from the band spectrum andplotted in the form of a curve. The hypothesis is now made thattwo atoms in different molecules can “ change allegiance ” readilywhen the nuclear separations of the two reacting molecules, here thctwo hydrogen iodide molecules, are such that they can give riseto two of the molecules, H, and I,, with the same total energycontent as themselves, and with no change of the various nuclearseparations in the process. This condition is analogous to onewhich Franck and Condon have found to hold in the transitionswhich spectroscopy reveals.In the example considered, theequation expressing the condition has naturally an infinite numberof solutions, a very large number of which Villars tabuhtes by trialmeasurements on the potential-energy curves. But, of all thesolutions, there is none in which the sum of the initial energies ofthe two hydrogen iodide molecules is less than an amount of theorder of magnitude of the observed heat of activation.*0a H. Kallmanii and 3’. London, 2. physilcccl. Chem., 1929, [B], 2, 207;21 Ibid., 1930, [B], 7, 244; A., 546.22 J. Amer. Chem. Soc., 1930, 52, 1733; A., 832.23 Physical Rev., 1920, [ii], 34, 92; A., 1929, 983.A . , 1929, 48720 IIIRSHELWOOI) :If this picture of the process of activation be a true one, it, 4’ rives agreat chemical importance to Franck’s principle.24 It may bercrnarked here that the existence of an energy of activation canbe accounted for by the following qualitative statement of what isreally implicit in Villars’s numerical computations.The equilibriumdistance between two hydrogen atoms in the hydrogen molecule isless than that between the two hydrogen atoms in two hydrogeniodide molecules colliding in such a way as to place the iodine atomsa t a suitable distance for formation of an iodine molecule. Accortl-ing to Franck’s principle, the distance. between the two hydrogennuclei must not vary during the atomic rearrangements. If, there-fore, the chemical change is to take place, a hydrogen molecule witha considerable potential energy of atomic separation must bcproduced.This can only happen if the original hydrogen iodidemolecules were activated to a degree sufficient to provide thisenergy. The idea contained in Villars’s paper is elaborated byJ. Franck and E. Rabinowitsch 25 to a rule, vix., that the heats ofactivation of bimolecular reactions must be greater the smaller theratio of the nuclear distances of the molecules involved to thcmolecular radii, which give the distance of nearest approach incollision. This principle, as they point out, leads to very smallheats of activation for reactions between such molecules as those ofchlorine and iodine, very high ones for reactions between suchmolecules as hydrogen, nitrogen, and oxygen, and intermediatevalues where hydrogen reacts for example with iodine.Something like the above seems very probably to represent thetrue nature of activation: the energy of activation can thus becalculated only when the potential-energy curves are known, aswell as some condition determining the point a t which rearrange-ment takes place.26 Many attempts are made to analyse themechanism of reactions by resolving them into stages involving theinitial production of free atoms or radicals, and the subsequentinteraction of these with other molecules : (a) AB = A f- B,(b) A + CD = AC + D, and so on.According to observations of&I. Polanyi and others 27 on reactions of the type Na + C1, =NaCl + C1, which occur in flames, every collision between a frccatom and a molecule is successful, i.e., no activation is needed, aslong as the change is exothermic.I n these circumstances, thc totalheat of activation of a complex reaction can be determined in termsof heats of linkage. For example, H. J. Schurnacher,2s discuss-24 See this Report, p: 22.2 6 Compare also A, Olander, 2. physikal. Chem., 1930, [ B ] , 7, 311.2 7 Ibid., 1028, [ B ] , 1, 3, 21, 30; A., 1928, 491.28 J . Arney. Chem. SOC., 1930, 52, 3132; A., 1255.25 2. Elektrochem., 1930, 36, 794; A , , 1378GENERAL AND PHYSICAL CHEMISTRY. 21ing the experimental data of M. J. P o l i ~ s a r , ~ ~ on the reactionCH,I-CH,I -+ CH,:CH, -1- I, in carbon tetrachloride solution,postulates CH,I*CH2 -- as an intermediate, and with the aid ofvarious assumptions deduces the energy of the C-I link and theenergy difference between the C-C and the C=C link.Althoughthere is much direct evidence that free atoms and radicals play theirpart in halogen reactions, yet such assumptions in other casesought not to be made unless justified by some direct positiveevidence.I n connexion with the above, it must be noticed that the principleof Polanyi mentioned, although a valuable and interesting general-isation, is not absolute, and that according to G. B. Kistiakowsky 30the fraction of successful collisions in the reactions C1 + H, =HC1+ H and 0 + H, = M + OH is less than lo3.While rejecting the assumption that energies of activation canin general be expressed in terms of heats of linkage alone, it is quitepossible to concede a certain general parallelism in the sense that thetighter the binding of the atoms in a molecule the higher will bethe heat of activation for reactions in which that molecule takes part.Thus, for certain purposes of qualitative comparison we may beable to make use of a knowledge of binding energies.R. Mecke3lconsiders a series of simple chemical reactions involving moleculessuch as CO,, H,O, N,O, and so on, tabulates dissociation energiesobtained from spectroscopic data, assumes that the reactions occurby way of free atoms and radicals, and uses the principle that thatatom splits off most readily which has the smallest energy of dis-sociation. By considering the relative probability of processessuch as CO, = C + 0, and CO, = CO -1-0, he draws a generalpicture of reaction possibilities which is in harmony with chemicalfacts.This, however, hardly proves that free atoms and radicalsparticipate in the actual processes which occur.Molecular Xpectra and Chemical Change.As a method for investigating the elementary processes of chemicalchange, the study of the relation between molecular speotra andchemical, or more particularly photochemical, behaviour is receivingmuch attention.32 Molecules give band spe~tra,3~ the generalposition of a band system in the whole spectrum being determinedby the electronic energy, the separate bands of a group correspondingz9 J . Amer. Chem. SOC., 1930, 52, 956; A., 548.:30 Ibid., p. 1868; A., 871.32 Compare the report by H. S. Taylor, J. Physical C’hem., 1930, 34, 2049.31 2.physikal. Chem., 1930, [B], 7, 108.See, e.g., R. Mecke, “ Bandenspektra und ihre Bedeutung fiir die Chemie,”Berlin, 1929; and S. Rarrntt, Ann. RPporfs, 1926, 23, 29722 RINSHELWOOD :to different numbers of vibrational quanta, and the fine structureof the bands depending on the varying numbers of rotational quanta.Sometimes the band system is succeeded on the short-wave side bya continuous spectrum, the disappearance of vibrational quantis-ntion indicating that the molecule is resolved into atoms. Bycomparing the energy corresponding to the frequency where thecontinuum begins with the thermally-determined dissociationenergy, it has been fourid that a liomopolar diatomic molecule isusiially resolved into one normal atom and one atom in an electronic-ally excited state.If the optical states of the atom are knownindependently, the thermal energy of dissociation can converselyhe e~timated.~~aIf the frequency of the active light in a photochemical reaction isknown, we can tell from the nature of the spectrum in this regionwhether the primary photochemical process has produced freeatoms or an activated molecule.The relation of continuous spectrum to band spectrum is notalways quite as simple as that just described. The alkyl halides,for example, give bands a t shorter wave-lengths and a continuousspectrum at longer ~ave-lengths.~~ This can be explained bysupposing that there exist two different ezectronic states of themolecule the dissociation limits of which are different.I n thehigher electronic state, the energy of the molecule is greater thanwould correspond to dissociation had the molecule been in thelower electronic state. Thus a spontaneous transformation ispossible, involving an electronic change and simultaneous dissoci-ation. Now, it is possible also that this spontaneous transformationfrom the discrete (band) region of the higher electronic level to thecontinuum of the lower does not occur when the molecule hasa large number of vibrational quanta, but does occur when ithas a small number. This state of affairs can arise when there isan appropriate relation between the potential energy-displacementcurves for the vibrating molecules in the two electronic andis accounted for by the Franck principle already referred to. Thisprinciple, which is founded on a study of intensity relationships inband spectra, asserts that electronic changes in a molecule onlyoccur in such a way that the accompanying change in nucleardistance and relative velocity of the two atoms is small.I n thepresent example, the change in nuclear distance accompanying thechange from the higher (undissociated) to the lower (dissociated)33a Compare R. T . Birge, Trans. Paraday Soc., 1929, 25, 707 ; A , , 1930,3.34 G. Herzberg and G. Scheibe, 8. physikul. Chem., 1930, [B], '7, 390.35 G. Herzberg, 2. Physik, 1930, 61, 604;Sponer, Nach. Ges. Wiss. Giitlingen, 1928, 241.A., 831; J. Franck and HGENERAL AND PHYSICAL CHEMISTRY. 23electronic state would be too great in the higher vibrational states.Hence these are stable.I n the lower vibrational states the changein distance is not too great and transformation occurs, followedimmediately by dissociation.The phenomenon known as “ pre-dissociation ” is explicablein a similar way. Some years ago, V. Henri discovered that, withdecreasing wave-length, but before the region of continuousabsorption is reached, the rotational fine structure of bands some-times disappears, the bands themselves remaining quite distinct.It is now known that the fine structure may sometimes reappear a tstill shorter wave-lengths. The appearance of the diffuse structure-less bands means that the rotations cease to be quantised while thevibrations still remain quantised.This depends upon the fact thatafter absorption of the light there is a redistribution of the variouskinds of energy in the molecule, which occurs during a period smallcompared with the time of rotation, but long compared with thetime of vibration.36 It probably involves the actual dissociationof the molecule.37 Bonhoeff er and Farkas showed that considerablephotochemical decomposition of ammonia did indeed occur in theregion of diffuse bands. Many substances show pre-dissociation,including nitrogen peroxide, sulphur vapour, benzaldehyde, acet-aldehyde, and other aldehydes. The existence of two frequencylimits, above and below which pre-dissociation does not appear,can be explained by Franck’s principle in a manner analogousto the explanation given above of the long wave-length continuum ofthe alkyl halides-with small frequencies the energy is not greatenough for dissociation, while with frequencies above the higherlimit the change in nuclear separations involved in the transform-ation to the dissociable state would be too great.Some progress is being made towards correlating the existenceof pre-dissociation with photochemical behaviour.With aldehydes,for example, Henri suggested that absorption of light in the pre-dissociation region leads to decomposition, while absorption of lightin the region of normal band absorption gives rise to activatedmolecules which tend to polymerise rather than to decompose.M. de Hemptinne 38 obtained experimental evidence in support ofthis point of view in the case of benzaldehyde.On the other hand,G. B. Kistiakow~ky,~~ studying the photochemical decompositionof nitrosyl chloride, in which two molecules are transformed forcach quantum absorbed, finds that the mechanism probably consists36 M. Born and J. Franck, 2. Physilc, 1925, 31, 411; A., 1926, ii, 26G.37 R. F. Bonhoeffer and L. Farkas, 2. physilcal. Chem., 1027, 134, 337.38 J . Phys. Radium, 1928, 9, 357.ng ,J. Amer. Chem. SOC., 1930, 52, 102; A . , 30624 HINSHELWOOD :in an excited molecule colliding with a second molecule. Thequantum of the active light is smaller than the heat of dissociation(thermally measured), and the band spectrum possesses rotationalfine structure, showing that " pre-dissociation " is not a necessarystate for chemical activation.As with thermal reactions, thedistinction between activation and dissociation is maintained.This is a suitable place in which to refer to the very interestingwork of R. G. W. Norrish40 on the photochemical equilibriumlight2 N O 2 7 5 2N0 f-- 0,. The reaction is of great interest in thatdarkthere exists a true " photochemical threshold " in the middle of theabsorption region. I n other examples, apparent critical wave-lengths a t which the photochemical change first becomes appreciableproved to be illusory and due to a rapid fall in the actual absorptionin the vicinity of the supposed threshold ~ a v e - l e n g t h . ~ ~ R. G .Dickinson and W. P. B a ~ t e r , ~ ~ however, obscrved such a limit forthe nitrogen peroxide dissociation in the region where no fall inabsorption occurred, and Norrish showed that the limit was quite asharp one, the quantum efficiency a t 436 pp being zero and thata t 406 pp being 0.74, rising to 2 a t shorter wave-lengths.Theabsorption is high and shows fine structure. V. Henri43 reportsthat pre-dissociation sets in between 370 and 380pp (there beingalso a second limit between 245.9 and 220.0 pp). Thus Norrishsuggests that the primary process is not dissociation of NO, intoNO 4- 0 but a collision between an excited NO, molecule and anormal one. It is also important to note that, when light of greaterwave-length than the threshold value is absorbed, it is emittedagain as a fluorescence which has been detected experimentally byNorrish and further studied by W.P. Baxter 44 (who, incidentally,finds a number of interesting results on the quenching of thefluorescence by foreign gases). Baxter, however, thinks thecollision mechanism unlikely, since the quantum efficiency a t 405 ppis not diminished by addition of carbon dioxide, nor by lowering thepressure to 0.01 mm.A problem allied to those discussed above, namely, that of therotational states of molecules produced by chemical reaction, istreated by H. Beutler and E. Rabino~itsch.~~ Considering" elementary " reactions of the types A + BC = AR -b C and40 J . , 1927, 761; 1929, 1158, 1604, 1611; A., 1927, 528; 1929, 893, 1022.41 E. J. Bowen, Truns. Faraday XOC., 1926, 21, 543.42 J . A.mpr. C'hena.SOC., 1928, 50, 774; A., 1928, 491.43 Nature, 1930, 125, 202; A., 272.44 J . Amer. Chem. SOC., 1930, 52, 3920; A ., 1500.4 s %;. physilra!. Ch~m., 1930, [ T i ] , 8, 233 ; A., 975GENERAL AND PHYSICAL CHEMISTRY. 25A 4- I3 = AB, they work out the relations which must hold,according to the quantum laws and the various inechanical con-servation laws, between the energy liberated in the reaction, theeffective “ collision area ” of the reacting molecules, and therotational state of the products. The results can be applied in aninteresting, if speculative, way to the interpretation of the experi-ments of E. Gaviola and R. W. who had found that inthe fluorescence light from a mixture of mercury and water vapour,the HgH bands emitted have a distribution of intensity correspond-ing to a predominance of small rotational quanta; while in theHgH bands from a mixture of mercury, hydrogen, and nitrogen, thehigher rotational states predominate.Modifying the originalexplanation of Gaviola and Wood for various reasons, Beutler andRabinowitsch suggest that the proccsses occurring are as follows :(1) Hg’ + H, = HgH + H (exothermic),(2) Hg’ + H,O = HgH 4- OH (slightly endothermic),(4) HgH’ = HgH + light.(3) HgH + Hg’ = HgH’ + Hg,The dashes signify optically excited states. React-ion (l), there isreason to suppose from the influence of hydrogen in quenchingmercury fluorescence, talies place as though the ‘‘ collision area ”were considerably greater than the normal kinetic theory value.47Thus, in collision, there can be a large turning moment, andmolecules in high rotational states can be produced. On the otherhand, reaction (2) appears to occur only at one collision in 3000;plausibly, therefore, we can assume that the collision area is nogreater than the normal one.Thus the turning moment is smalland low rotational quantum states result. The last step in theargument is certainly not entirely convincing, but the investig a t’ 1011is a good example of the way in which attempts are being made tobring spectroscopic evidence to bear on chemical problems.The Probability of Spontaneous Molecular Tranqformation.I n a unimolecular chemical reaction the current view is thatthere is a supply of activated molecules, maintained by collision,and that there is a definite probability that a given molecule willundergo transformation before losing its energy.48 This probabilitymay or may not be a continuous function of the excess of energypossessed by the molecule over the minimum required for “ activ-ation.” It may in principIe--and especially according to quantum-46 Phil. Mug., 1928, 6, 1191; A,, 1929, 239.5 7 Compare refs.20 and 44.See Ann. Reports, 1927, 24, Section on “ Chemical Kinetics.26 HINSHELWOOD :mechanical theories-even be a continuous function of the energycontent over the whole range of values, with no sharp thresholdof activation. But according to all theories the vast majority of themolecules which are transformed possess energies in a narrow rangein the neighbourhood of the energy of activation.The probabilityof transition of these molecules is found experimentally to be suchthat the time elapsing between activation, “ classically ” regarded,and transformation is of the same order of magnitude as the periodof revolution of an electron in its orbit. M. Polanyi and E. Wigner 49arrived a t this same numerical value by a theory based upon theinterference of elastic waves in the molecule leading to a concen-tration of energy a t a particular point. More recently, attempts havebeen made to treat the problem by the application of quantum-mechanical considerations. The results are not very definite, butthe principles involved are extremely interesting.All the attempts are adaptations of the Gamow theory 50 ofradioactive disintegration, or of the wave-mechanical theory of“ radiationless transfers ” of ele~trons.~l It is first necessary t oexplain these two theories sufficiently to show the chemical analogies.First, with regard to the question of nuclear disintegration, insidean atomic nucleus an a-particle must be under the influence of anattractive force, since nuclei in general are in fact stable.Outsidethe nucleus it suffers a repulsion, which is in accordance withCoulomb’s law when the distance from the centre of the nucleusis greater than about 10-12 em. Yet, after escaping from a nucleus,the a-particle is found not to possess the kinetic energy which itshould if the repulsive forces had acted on it from the point wherethey begin to be effective.This is expressed by saying that thea-particles ‘( leak through ” the potential barrier surrounding thenucleus. In the wave-mechanical treatment of the matter, wetake a rather idealised form of potential barrier, and write downthe equations expressing the amplitude of the wave function(the square of whose absolute magnitude gives the relativenumber of a-particles in an element of volume) for three regions,vix., inside the nucleus, in the barrier itself, and outside the nucleus.These equations involve the potential energy of the particle in thevarious regions. Then in a way somewhat analogous to Fresnel’streatment of reflexion and refraction of light, 52 the conditionis written down that the wave function and its differential coefficient49 2.physikal. Chem., 1928, 139, 439; A., 1929, 404.G. Gamow, 2. Physik, 1928, 51, 204; A., 1929, 7.5 1 G. Wentzel, Physikal. Z., 1928, 29, 321; 2. Physik, 1927, 43, 524; A4.,63 Compare, e.g., Preston’s “ Light.”1927, 807GENERAL AND PHYSICAL CHEMISTXY. 27shall be continuous at the two boundaries. In this way we find theamplitude of the wave outside the nucleus, which determines theprobability of escape of the a-particle. It must be remarked thatthe wave-mechanical treatment does not explain why an a-particlecan escape from a region which it could not possibly leave in a" classical " manner : being a statistical method of calculationusing continuous equations, it automatically provides for a certainconcentration of or-particles outside the nucleus and then determinesa value for this concentration. The important success of thetheory is that it gives the Geiger-Nuttall law for the relation betweenthe energy of the particle and its rate of escape, and moreover, withthe numerical coefficients approximately correct.*If we are prepared to admit that the transformation of anactivated molecule is analogous to the disintegration of a nucleus,an analogous treatment becomes possible.53 The actual probabilityof transformation cannot be satisfactorily estimated, but theinteresting possibility arises that, just as those radioactive changesoccur most rapidly which give or-particles of the greatest energy,so those unimolecular reactions which are most exothermic shouldhave the greatest values of the constant B in the equation k =But there is no particularly good ground for assuming that thechemical changes of an activated molecule are really a t all similarto a radioactive decay.The analogy of a " radiationless transfer ''of an electronic system to a state of equal energy is perhaps closer.To understand the wave mechanics of this we must again rid ourminds of the idea that we are giving individual attention to anymember of an assemblage : the equations refer to the assemblageitself. Suppose, for simplicity, that we have a molecule AB capableof splitting up into A and B. Before and after the transformationthe parts A and B can be thought of as possessing definite totalenergies. If letters with dashes refer to the final state, EA + EB =* The classical and wave-mechanical treatments may be compared withthe aid of an analogy.I f a large number of men stood before a wall whichmany could nearly but none quite jump, classical mechanics would allownone over, but wave mechanics would let a few over, the proportion beingsmaller the more the wall was beyond the reach of the individuals classicallyconsidered. The result is inherent in the use of the equations which only dealwith assemblages. I f it is asked why even a small proportion of classicallyimpossible things occur, the only answer is that the question has no meaning.This answer fails to satisfy many people; whether because their habit ofmind is too fixed, or because the answer is an evasive one, time must show.53 S.Roginsky and L. Rosenkewitsch, 2. physikal. Chem., 1930, [BJ, 10,47 ; A., 1377 ; where references to the work of Bourgin, Oppenheimer, andLanger are also given. Compare also remarks by 0. K. Rice, Physical Rez!.,1929, [ii], 34, 1451.Be-EIRT28 IIINSHELWOOD :EAe f- EB.. Now consider an assemblage of AB molecules. Itsbehaviour is described by a wave function with a frequency obtainedby dividing E, + Ex by h. The assemblage of transformedmolecules has a wave function with the same frequency (by theconservation oE energy). Thus, even if the amplitude of its wavefunction is initially zero, it will grow by resonance.54 The rate ofchange of amplitude determines the probability of the individualtransformations. Such a treatment has been successfully appliedto the Auger effect (transfer of an electron to a new orbit withsimultaneous ejection from the atom of a second electron).I ntheir application of the method to a chemical reaction, Roginskyand Rosenkewitsch deduce as a positive consequence that, in theequation li: = Be-EiRT, the logarithm of the constant B shouldbe proportional to (& - E)/dE, where & is the heat of reaction.(The signs are such that the absolute values of & and E are addedfor exothermic reactions.) This result is similar to that inferredfrom the assumed applicability of some analogue of the Geiger-Nuttall law to chemical reactions.The experimental evidence is very doubtful. Unimolecularreactions of sufficiently varied heat of reaction are scarcely known.Roginsky and Rosenkewitsch consider the general balance ofevidence in favour of such a relation, but their analysis is not veryconvincing.* The real need is for more suitable examples by whichto test the relation.This is always the difficulty.Problems of Xtructure.We now turn from dynamical problems to questions of structure.One of the most direct ways of obtaining information about theconfiguration of simple molecules is the careful analyRis of infra-red spectra 55 or of the fine structure of visible and ultra-violetband spectra. The magnitudes which can be directly inferredfrom such measurements are the principal moments of inertia ofthe molecule. When these are known, models giving the distancesbetween the various atoms can be devised to fit them. The valueof the dipole moment of the molecule serves as a useful independent* For example, in Fig.6 of their paper, referring to imimolecular gas rc-actions, there are 8 points, through which two straight lines are drawn. Thepoint relating to Dienger’s reaction should not be included, since the reactionis almost certainly not a homogeneous change a t all. When this is omittedthe remaining points appear almost randomly grouped about a mean.54 Perhaps the clearest treatment of quantum-mechanical transitions as acase of resonance between wave functions is that of E. Schrodinger, Ann.Physik, 1927, [iv], 83, 056.5 5 Compare C. Schaeffer and P. Matossi, “Das Ultrarote Spektrum,”Berlin, 1930; R. Mecke, 2, Elektrocliem., 1930, 36, 589; A., 1343GENERAL AND PHYSICAL CHEMISTRY.29control. A perfectly symmetrical molecule has all three principalmoments of inertia equal; a molecule like a,mmonia, which has aregular pyramidal structure with the nitrogen a t the apex, has twoof the three moments equal; and a molecule like that of water hasthree different values.According to the theory of spectra, the frequency of a line is givenby hv = AE,,. + AEvib. + AErOt. where AEela, etc., represent the changesin electronic, vibrational, and rotational energy accompanying the“quantum jump.’, Since the moments of inertia determine therotationalquanta, they are found from theAEr0, terms. I n the simplestcase, a quantum jump from the mth to the (m - 1)th rotationalstate is represented by a frequency vrot.= mh/4x2A. The moment ofinertia, A , can be found from the spacing of the pure rotation bandsin the long infra-red, from the spacing of the rotational fine structureof the vibration bands in the short infra-red, from the distancebetween the maxima of intensity in the P and R branches of aninfra-red double band, and also from the fine structure of theelectronic band spectra. Not all methods are always applicable.I n an infra-red rotation vibration spectrum, the P and H brunchesrepresent respectively the parts of the band where the rotationquantum is deducted from or added to the vibrational energy. Thepresence or absence of a &-branch is significant : this branchrepresents the pure change in vibrational energy without anaccompanying change of rotational state, and is nearly alwaysabsent from the infra-red spectra of diatomic gases.The number of fundamental frequencies occurring in the infra-red vibration spectrum is also an important matter, though notalways an easy one t,o settle.It is closely connected with thestructure of the molecule : for example, if methane has the tetra-hedral form it should possess four, a triatomic non-linear moleculein general has three, whilst a diatomic molecule has one only. Avibration in which the electric moment of the molecule does notchange gives rise to no infra-red absorption band, but can combinewith another frequency and appear, for example, in the Ramaneffect.56 Two of the four theoretical frequencies of the tetrahedralmethane model would be inactive in this sense.I n the light of these general considerations, some of the recentwork can be summarised.C. R. Bailey 57 discusses afresh thequestion of the water molecule, previously treated by Eucken,Hund, Mecke, and others. The essential facts are that the infra-red spectrum gives three values for the moments of inertia, andrequires two fundamental frequencies for its interpretation (two6G See Ann. Reports, 1929.6 7 Trans. Faradny SOC., 1930, 26, 203; A . , 66130 RINSHELWOOD :of the three theoretical frequencies are equal, or one is inactive).All models are variants of a triangular one. Bailey favours anisosceles triangle, the equal sides of which are 1-07 x 104 em. andthe included angle 64".Eucken's model gave 1.03 x lo4 cm. and110" 56', Hund's 1.04 x 104 cm. and 64", and Mecke's 0.86 x lo4cm. and 96". P. I. G. R a ~ l i n s , ~ * discussing the carbon dioxidemolecule, decides in favour of the accepted linear form. Furtherwork has been done on the spectrum of ammonia : 59 all the infra-red bands are stated to be derivable from three fundamentalfrequencies. Badger and Mecke find three moments of inertia,of which two are nearly equal (2.74 and 2.79 x C.G.S. unitsrespectively)-complete symmetry of the pyramidal structurewould require two to be exactly equal. These authors estimate theheight of the pyramid to be 0.517 x lo4 cm. and the distancebetween the hydrogen atoms to be 1.43 x lo4 cm., neglecting theslight asymmetry indicated by the imperfect equality of twomoments of inertia.C. P.Snow and E. K. Rideal 6o find that the overtone of thepreviously investigated nitric oxide band has a &-branch like thefundamental, but unlike most diatomic molecules. The anomalyis connected with the presence in the nitric oxide molecule of anodd number of electrons, the existence of the electron impulseremoving the prohibition of an rn ---+ m transition. C. P. Snow 61has investigated nitrous oxide and suggests a linear structuresimilar to that of carbon dioxide and carbon disulphide.61a Atten-tion has also been given to the infra-red properties of ozone,62benzene and its halogen derivative^,^^ and a~etylene.~* The lastappears to be quasi-diatomic, with one moment of inertia, theC E C distance being 1.19 x em.V.Henri and his collaborators have attacked the problem ofpolyatomic molecules by studying the visible and ultra-violetspectra. V. Henri and S. A. Schou 65 had shown that formaldehyde5 8 Truns. Puraduy SOC., 1929, 25, 925; A., 1930, 19.ti9 R. M. Badger and R. Mecke, 2. physilcal. Chem., 1929, [ B ] , 5, 333; A.,1929, 1363; R. M. Badger, Physical Rev., 1930, [ii], 35, 1038; J. W. Ellis,J. Pmnklin Inst., 1929,208, 507; compare Robertson and Fox, Ann. Reports,1928, 25, 11.6o Proc. Roy. Soc., 1930, [ A ] , 126, 355; A., 273.G 1 Jbid., 1930, [ A ] , 128, 294; A., 1089.61a C. R. Bailey and A. 13. D. Cassie, Nature, 1930, 126, 350; A., 1346.62 0. R. Wulf, Proc. Nut. Acad. Sci., 1930, 16, 507; A,, 1226.64 K.Hedfeld and R. Mecke, 2. Physik, 1930,64, 151; A., 1235; W. H. ,T.Childs and R. Mecke, ibid., p. 162; A., 1236; R. Mecke, Z. h'Zeli$rochem.,1980,36,803; A., 1343.J. F. Daugherty, Physical Rev., 1929, [ii], 34, 1540; A., 1930, 273.O 6 Z. PhymX, 1928, 49, 774; A . , 1928, 935GENERAL AND PHYSICAL CHEMISTRY. 31has a Y-shaped molecule, the fine structure of the bands revealinga double set of rotational states. More recent work showscarbonyl chloride and thiocarbonyl chloride 66 to have structuresanalogous to that o€ formaldehyde. Among other studies of spectramay be mentioned those of chlorine,67 chlorine monoxide,68 andchlorine di~xide.~gA fundamentally new method of investigating the structure ofmolecules has been developed by Debye.It allows X-ray intev-ference measurements to be carried out with molecules in thegaseous state. The diffraction effects observed in the experimentsof Laue and Bragg depend upon the regular arrangement of scatter-ing centres in a crystal lattice, and it might be supposed that with agas the random orientation of the molecules would destroy anytrace of diffraction maxima and minima. As early as 1915, however,it was calculated by P. Debye 70 and by P. Ehrenfest 71 that, if abeam of X-rays passes through a gas the molecules of which containseveral atoms capable of exerting a scattering action, then theintensity of the scattered radiation, averaged over all possibleorientations of the molecules themselves, still shows maxima andminima a t definite angles. If the molecules contain atoms 1 .. . i ,j . . . n, the scattered intensity is given by the formula y28 is the angle between the primary and t h i scattered ray, 9 is afunction representing the scattering power of the individual atoms,and xij = 1, sin - , A being the wave-length of the radiation and1, the distance of the atom i jrom the atom j in the molecule. Theimportant term is sin x/x which gives maxima and minima with aspacing depending on 1. To a first approximation, the + terms maybe taken as constant, but a more exact treatment is given byDebye.73The maxima and minima were first detected experimentallywith the vapour of carbon tetra~hloride.~~ The principle of theapparatus is illustrated in Fig. 1.66 V.Henri and 0. R. Howell, Proc. Roy. SOC., 1930, [ A ] , 128, 178; A , ,1088.6 7 A. Elliott, Proc. Roy. SOC., 1930, [ A ] , 12’7, 638; A., 977.6 8 C. F. Goodeve and J. I. Wallace, Trans. Faruduy SOC., 1930, 26, 254;69 C. E’. Goodeve and C. P. Stein, ibid., 1929, 25, 735; A , , 1930, 11.‘O Ann. Physik, 1915, 46, 809.71 Vers. K. Akad. Amsterdam, 1915, 23, 1132.72 P. Debye, Proc. Physical SOC., 1930, 42, 340; A., 977.73 Jdem, Physikal. Z., 1930, 31, 419; A., 843.74 P. Debye, L, Bewilogua, and F. Ehrharclt, ibid., 1929, 30, 84.4n 0A 2-4 ., 66032 IJTNSHELWOOD :Three maxima coiild be observed a t 36", GCi", and 110'. Thecontribution of the carbon atoms to the scattered radiation isnegligible ; only the four chlorine atoms count. Calculation, withthe appropriate corrections, gave the value I = 2-99 x em.for the distance between any two of them.Themaxima are faint with carbon dioxide but marked with carbondisulphide.It appears that when the atoms themselves areapproximately half as big as the distance between them the effectsbecome obscured. For the distances between the chlorine atoms incis- and trans-dichloroethylene, the values found are respectively3.6 and 4.1 x cm. For ethylidene dichloride the distance is4.4 x 10-8 cm.75 It is evident, that the structure of the moleculeNo diffraction can be detected with oxygen and nitrogen.Fza. 1.H E A T C D CELLWINDOW !- x- $A%+can be searchingly investigated by this new method. Analogousresults have been found by R. Wierl 76 for the scattering by carbontetrachloride and other substances, not of X-rays), but of fast-movingelectrons.After the study of simple isolated molecules, the natural transi-tion is to that of their aggregation to form liquids and solids.Attempts have been made by Debye and H.Menke 77 to disentanglethe intermolecular from the intramolecular part of the X-ray inter-ferences from liquids, and promise to throw light on the obscure ques-tion of the true structure of liquids), but are hardly ripe for report yet.It appears, however, that in mercury certain distances of theatoms from one another are favoured at the expense of others in a" quasi-crystalline " way. With regard to solids, the X-ray analysisof crystal structure is being systematically extended to everyconceivable type of substance ; the theory of ionic lattices, originally7 5 P.Debye, Physilcal. Z., 1930, 31, 142 ; A., 400.73 Ibid., p. 366; A., 652. 7 7 Ibid., p. 797; A., 1350GENERAL AND PHYSICAL CHEMISTRY. 33attacked by Born, is gradually being developed with help fromquantum mechanics and from the infra-red investigation of ioniccrystals; and progress is being made with the theory of metals.These matters must unfortunately be passed over here with thismere reference. A few details may, however, be singled out forconsideration.Much attention has been given in the last few years to the X-rayanalysis of compounds, such as cellulose and its derivatives, whichpossess a fibrous structure resulting from an orientation of " crystal-lites " or " micelles " parallel to one particular axis.These substancesare interesting as a transition from simple molecules and structurestowards the complex organisations adapted to the functions oflife. The method of investigation 78 is essentially to examine theX-ray diagrams obtained under two sets of conditions. When therays fall on the material in the direction of the fibre axis, a Debye-Schemer pattern is obtained, because the micelles or microcrystalsmay have all possible orientations except for the direction of theirlong axes ; when, however, the rays are incident perpendicular tothe axis of the fibres, a different type of pattern is obtained, sincethe long axes are parallel to the fibres (fibre diagram).By applying this metlhod of analysis, the changes occurring incellulose under the action of chemical reagents on various physicaltreatments can be irivestigated. Most of the work is too specialisedto summarise, but may be exemplified by that of K.R. Andres~,'~who concludes that the change occurring during the " mercerisation "of natural cellulose is the rearrangement of the main chains to morestable relative positions. H. Mark and K. H. Meyer 8o distinguishtwo kinds of reaction of cellulose, " micellar surface reactions " and" permutoid " reactions. In the first kind, the reagent penetratesbetween the micelles without attacking their internal structure ;the orientation may, however, be disturbed and the '< fibre " diagramchanges to a Debye-Scherrer diagram.In the second kind ofreaction, the reagent penetrates the whole structure, attackingspecific chemical groupings a t each point of the lattice.Although they relate to a different type of structure, it is interest-ing to mention some measurements made by A. Muller.81 He hasfound that while the short axes of long-chain normal paraffinschange on the average by 6SY0 and 1.90/, respectively between thetemperature of liquid air and the melting point, the change in thelong axis is too small to measure. This indicates that the end7 8 For list of references see (Sir) W. H. Bragg, ATuture, 1030. 125, 6.74.79 2. physilcal. Chenz., 1929, [B], 4, 190; A., 1930, 280.8" Ibid., 2, 115; A., 1929, 246.81 Proc. Roy. SOC., 1930, [ A ) , 127, 417; A ., 844.EE P . -vo I,. x x v TI. I31 HINSHELWOODgroups of the molecules move apart, but that the length of thechain probably does not alter with increasing temperature.In the region of more complex systems, the investigations ofT. Svedberg,82 by means of the ultra-centrifuge, on the dispersityof protein solutions have now yielded an interesting picture. Thereare “ monodisperse ” systems (i.e., of homogeneous molecular weight)such as hzmoglobin and egg-albumin solutions, the former of whichcontains particles of molecular weight 68,000 with four iron atoms ;and there are “ polydisperse ” systems, including gelatin and casein,the particles of which vary and are in a labile condition. Haemo-cyanins, which are monodisperse, have ‘‘ molecular weights ” ofseveral millions.Xurface Chemistry.From the work of Rayleigh, Pockels, Devaux, Langmuir, andAdam, it has emerged that the unimolecular films formed by thespreading on water of insoluble substances, such as compounds withlong hydrocarbon chains and an active end group, form a state ofmatter, the properties of which may be interpreted by an adaptationtn twn dimensions of the ordinary three-dimensional kinetic theory.83The normal method of investigating the properties of these filmsis to plot the “ surface pressure,” F , i.e., the number of dynes percm.applied to a barrier compressing the film, against the area, A ,of the film. Gaseous films, condensed films, and an intermediatetype which Adam calls “ expanded films ’’ are found.I n thegaseous film there is free motion of the molecules over the surface,and in favourable examples, such as the esters of dibasic acids, thevalue of FA for low ‘‘ pressures ” approaches quite closely to thevalue, kT, derived from the two-dimensional kinetic theory. As thepressure increases, F A passes through a minimum, following acurve analogous to Amagat’s pu curves for imperfect gases.Condensed films possess very much smaller areas, even at zeroconipression, indicating that there is it powerful lateral adhesionbetween the molecules, analogous to that which keeps matter inbulk in the condensed state. The area occupied per molecule isindependent of the length of the hydrocarbon chain, as long as thenumber of carbon atoms is greater than about twelve.The smallestarea a t zero compression is about 20-5 sq. A., while the area of thebase of the corresponding hydrocarbon chain in crystals is shownby X-ray measurements to be about 18.4 sq. 8. Thus, either themolecules in the film are rather less closely packed, or the chain is82 Kolloid-Z., 1930, 51, 10; A . , 694.83 Compare N. K. Adam, “ Phvsics and Chemistry of Surfaces,)’ Oxford,1930GENERAL AND PHYSICAL CHEMISTRY. 35tilted somewhat in the film, an angle of tilt of about 27” beingrequired to account for the approximately 10% greater base area.Some compounds require bigger areas than 20.5 sq. 8., and theseareas vary under compression, indicating a rearrangement of theheads of the chain. In condensed films, allotropic changes mayoccur a t definite transition temperatures.The most interestingphenomenon is the passage from the “ gaseous ” to the “ condensed ”state in the film : a t a certain pressure, the “ vapour pressure ” of thecondensed film, the gaseous film may collapse to the small area charac-teristic of the condensed state. The collapse does not occur if the tem-perature is above the “ critical ” temperature. The curves givingthe relation between F and A for different temperatures form a seriesanalogous to Andrews’s well-known isothermals of carbon dioxide.The most recent work has dealt with the esters of fatty acids **and with long-chain amine~.*~> 85 The lower alkyl palmitates formthe normal condensed films of area 20.5 sq. A.y intermediate membersof the palmitate series form (‘ expanded films ” of about 85 sq.A.,while the higher members, e.g., n-hexadecyl palmitate, give con-densed films of area 41 sq. A. The last class clearly have doubleclose-packed chains, corresponding to the single chains of thelowest members whose alkyl groups probably plunge into the water.The abnormal behaviour of the intermediate members is explainedby a violent oscillation of the hydrocarbon chains, to which Adamattributes the existence of “expanded” films in general. (Itshould be noted that the area of the expanded type is still muchcloser to that of a condensed film than to that of a gaseous film.)Results obtained with the amines lead Lyons and Rideal to main-tain their previously suggested hypothesis of the “ interlocking ”of chains in stable films, an hypothesis which Adam criticisesadversely.The existence of two surface phases in equilibrium with eachother, which the study of films has demonstrated, has been shownby N.Semenov 86 to yield a simple theory of the rather remarkablephenomena attending the condensation of metal vapours on tosurfaces. As is well known, there exists a critical temperaturebelow which the vapour condenses on to a cold surface, but abovewhich it is entirely reflected; at the critical temperature the degreeof supersaturation of the metal vapour is already very great. Theproposed explanation is as follows. The vapour is in adsorptionequilibrium with a “ gaseous ” film on the surface : when the pressureIdem, Proc.Roy. SOC., 1930, [ A ] , 126, 366, 526; A., 408.85 C. G. Lyons and E . K. Rideal, ibid., 1930, [A], 128, 468; A . , 1110.2. physikal. Chem., 1930, [ B ] , 7, 471; A., 851; compare J. Frenkel’smore elaborate theory, Ann. Report8, 1928, 25, 35236 HTNSHELWOOT) :in the film reaches the two-dimensional critical pressure a condensedfilm is formed, which can then act as a basis for the building up ofmassive metal, if the vapour pressure of the metal in bulk is greaterthan the surface critical pressure. Analogously, there will be acritical temperature, where the pressure in the vapour correspondingto the surface critical pressure is no longer smaller than the saturatedvapour pressure.The assumption of a '' gaseous " surface film in this connexionimplies that the adsorbed molecules can move freely over the surfaceof the solid.That this is possible in certain circumstances has forsome time appeared probable from the work of Volmer. The ideaof lateral diffusion and the conception of surface gas pressure havebeen used by F. J. Wilkins and A. F. H. Ward87 in discussing thequestion of the variation with temperature of the maximum amountof gas which a surface can adsorb. According to the simpleLangmuir theory, there is no reason why the saturation limit shouldvary appreciably with temperature (except in special circumstances,such as multiple point adsorption depending very much on theexact spacing of the centres). Wilkins and Ward assume, however,that saturation is reached when the surface pressure of the adsorbedgas reaches some definite value: the temperature coefficient ofthe adsorption maximum would then be of the same order ofmagnitude as the coefficient of expansion of a gas.The actualexperimental values are said to fit in roughly with this idea : theyvary by a factor of about 3, which, however, might be expected,since the proposed criterion of saturation is an indefinite one andcan only be very roughly true.The mobility of adsorbed molecules on the surfaces of solid bodiesis a question of some general importance. Experiments 8* on thegrowth of mercury crystals from the vapour seemed to indicate thatthere were adsorbed molecules of mercury on the crystal surface,but not part of its structure, and that they possessed mobility.Italso appeared that molecules of benzophenone could move over thesurface of glass. In the light of these observations, catalyticreactions on a solid surface present a slightly different picture fromthat of Langmuir's original theory, though the essential kineticrelationships are not profoundly modified. For example, supposewe have small adsorption and proportionality between gas pressureand adsorbed amount for each of two reacting substances A and B.If the molecules of A and B are rigidly held, reaction depends upontheir alighting from the gas phase to adjacent positions on the2. physikal.8 7 2. physikal. C'hem., 1929, [ A ] , 144, 259; A., 1929, 1376.88 M. Volmer and G. Adhikeri, 2. Physik, 1925, 35, 170;Chcm., 1926,119, 46; A., 1926, 349, 467GENERAL AND PHYSICAL CHEMISTRY.37surface : the probability of which is proportional to the productof the two pressures. If A and B are freely mobile they may, onthe other hand, seek each other out in the adsorption layer : but,although the mechanism is somewhat different, the probabilityof an encounter is still proportional to the product of the pressures,In fact, it seems clear that the relation between the probability ofreaction and the gaseous concentrations ought to be the samewhether the movement of the molecules is realised by translationover the surface or by passage through the gas. Surface mobilityis formally equivalent to a shorter time of sojourn on the surface inLangmuir’s sense.It is by no means certain, however, that the powerful adsorptionforces acting between surfaces and reacting gases such as oxygen,hydrogen, or carbon monoxide will allow mobility in any degreecomparable with that found in Volmer’s experiments.M. Polanyiand K. Welke show that different parts of a charcoal surface areassociated with very different adsorption energies, and that thedensity and mobility of the adsorbed molecules must vary over acorrespondingly wide range.S9 Quite probably, the most importantcases catalytically are those where very strong binding producesgreat internal changes in the molecules and also greatly reducesor inhibits mobility. A. A. Balandin has developed an hypothesisoriginally put forward by R. E. Burk, namely, that in some catalyticreactions the molecules are adsorbed, not a t one, but a t severalpoints of the surface, and has illustrated the helpfulness of thehypothesis in a number of examples. In reactions where thisso-called ‘‘ multiplet ” adsorption is important, mobility mustpresumably not be great.This is a convenient place to refer to the work of F.P. Bowden andE. A, O’C~nnor,~~ who measure the quantity of electricity whichmust be passed in order to cause a given change in the electrodepotential of a cathode immersed in dilute acid. This quantity isassumed to be proportional to the “ accessible area ” of the cathode.This area is available for the liberation of hydrogen, which can beregarded as a catalytic surface reaction-probably depending on theunion of atoms.A fusible alloy and liquid gallium give similarresults, indicating that the accessible area of all liquid metals isthe same.A number of novel methods have been used for investigating thes9 Z. physikal. Chem., 1928, 132, 371 ; A., 1928, 580.90 For references to this work and a summary, see J. C. W. Frazer, 8thReport of the Committee on Contact Catalysis, J . Physical Chem., 1930, 34,2129.91 Proc. Roy. SOC., 1930, [ A ] , 128, 317; A., 113138 HLNSHELWOOD :nature and structure of surface layers. It is of interest to recordsome of them, although the results obtained by their application havenot yet thrown very much really fresh light on the matter. Whenelectrons are diffracted by a solid they penetrate it to a very smallextent only.Thus the diflraction effects yield information aboutthe surface layers. G. P. Thomson and C. G. Fraser92 havedescribed a suitable apparatus for such investigations, andThomson 93 gives an account of exploratory experiments withdifferent surfaces. E. Ruppg4 has measured the electron wavesdiffracted by metal surfaces charged with adsorbed gases, andobtained definite effects due to the gases, while he and E. Schmid,95applying the method to passive iron, conclude that passivity isdetermined entirely by the surface layer of atoms. J. Aharoni andF. Simon 96 have measured the magnetic susceptibilities of adsorbedgases, and, among other effects, find a discontinuity in the curveconnecting concentration and susceptibility for oxygen adsorbed oncarbon : they suggest a transition from a single to a double layerof adsorbed molecules.J. W. McBain and C. R. PeakerYs7 bystudying the conductivity due to films of fatty acids on water,show that stearic acid in a unimolecu!ar layer on water of conduct-ivity 1.2 x 10-6 reciprocal ohms is dissociated to the extent ofabout one-ninth. Optical methods have been used by J. Perrin98and by H. Zocher and F. Stiebelys9 and a photoelectric method byR. S ~ h r m a n n . ~ ~ ~ H. Dobretsberger finds an increase in the'( skin '' conductivity for high-frequency currents in platinum wires,on which nitrogen and carbon dioxide are adsorbed, which does notoccur with direct current. Hydrogen alters both kinds of con-ductivity. L. Strohhacker confirms the unimolecularity of gaslayers adsorbed on gold, using a method depending on directweighing.Some discussion continues about the appropriate form of theadsorption isotherm, and about the nature of the saturation process.H.W. Foote and J. K. Dixon,3 working with the systems water or92 Proc. Roy. SOC., 1930, [ A ] , 128, 641; A., 1082.94 Z . Elektrochem., 1929, 35, 586; A., 1929, 1357; Ann. Physik, 1930, [v],sg Natumuiss., 1930, 18, 459; A., 1230.9 6 Z . physikal. Chem., 1929, [B], 4, 175; A . , 1930, 278.9 7 PTOC. Roy. Xoc., 1929, [ A ] , 125, 394; A., 1929, 1378.9s Kolloid-Z., 1930, 51, 1 ; A., 657.09 2. physikal. Chem., 1930, 147, 401; A., 852.g90 2. Elektrochem., 1929, 35, 681; A., 1929, 1359.Ibid., p. 649; A., 1082.5, 453.2. Physik, 1930, 65, 334; A., 1605.J .Amer. Chem. Soc., 1930, 52, 2170; A., 990.Ibid., 1930, 64, 248; A,, 1364GENERAL AND PHYSICAL CHEMISTRY. 39benzene vapour-manganese dioxide, and J. N. Pearce and H. F.Johnstone 4 with methane or its chlorine derivatives-charcoal,find results in agreement with Polanyi’s theory. J. W. McBainand G. T. Britton conclude that adsorption by charcoal occursaccording to the Langmuir formula and is not adequately representedby any other. On the other hand, M. Crespi and E. Moles6conclude that the adsorption of ethylene by glass is in accordancewith Freundlich’s equation but not with Langmuir’s. R. Strom-berg finds that the adsorption of water by various surfaces increasesto very many molecular layers as the saturation vapour pressureis approached, and J.W. McBain and R. Du Bois find that theamounts of substances carried by bubbles from solutions are severaltimes greater than would correspond to a unimolecular layer ofmolecules oriented in the surface.The conclusion to be drawn from all these observations is probablythat, while the Langmuir theory represents the ideal to which manyactual examples approximate, the complexity of structure of manysurfaces, the existence of capillary condensation, and multiplelayer formation in the neighbourhood of the condensation pointof vapours introduce complications making it necessary almostalways to determine by ad hoc experiments the adsorption isothermsand saturation limits for a particular system, the behaviour of whichis required for practical purposes to be known.Many papers have been published dealing with the specificrelations of particular adsorption systems.However valuablethese may be as contributions to the inorganic chemistry of surfaces,it is impossible to summarise them under a single heading. Certaingeneral tendencies have, however, been evident. One interestingpoint is the influence of adsorbed “permanent” gases on theadsorption capacity of charcoal for vapours and substances insolution. A. J. Allmand and R. Chaplin: in the course of a detailedstudy of adsorption by various charcoals, found that traces offoreign gases on the surface of the charcoal have a very greatinfluence on the isotherms of carbon tetrachloride vapour a trelatively low pressure.Gradual elimination of gases causes adrift in the adsorption, no final steady value being attained untilthe displacement is complete. A freshly prepared active charcoal ispoisoned by oxygen, the poisoning being greatest at the most activeJ . Physical Chem., 1930, 34, 1260; A., 989.J. Arner. Chem. SOC., 1930,52, 2198; A., 990.13 Anal. Fit?. Quim., 1930, 28, 448; A., 990. ’ Kungl. Svenska Vetenskapsakad. Handl., 1928, 6, [2], 1 ; A., 151.* J . Amer. Chem. SOC., 1929, 51, 3534; A., 152.9 A. J. Allmand and R. Chaplin, Proc. Roy. SOC., 1930, CAI, 129, 235; A.,151340 HIN SHELWOODpoints on the surface. The oxygen is gradually replaced, by theaction of the carbon tetrachloride, in the form oi carbon monoxideor dioxide. The displacing action of a vapour such as carbon tetra-chloride appears sometimes to remove oxygen more effectivelythan evacuation.The chemical mechanism of adsorption also presents problems ofinterest.The adsorption of electrolytes by charcoal is supposed byN. Schilov lo to depend upon oxide films, two '' basic oxides " andan " acidic oxide '' being assumed to exist on the surface. A.Frumkin l1 takes the view that charcoal adsorbs ions from solutionin virtue of behaving like a gas electrode. Charcoal degassed ina vacuum for 48 hours at 1000" would not adsorb hydrogen chlorideor sodium hydroxide. On addition of oxygen, the adsorptioncapacity for the former reappeared, the amount taken up beingchemically equivalent to the amount of oxygen supplied. It issupposed that the adsorbed oxygen sends hydroxyl ions into solution,these being replaced at the surface by the acid anions : C,O +H,O -+ C, + 2@ + 20H'.When, on the other hand, the char-coal is heated in hydrogen, all the above effects are reversed. Thecharcoal is now supposed to be able to send hydrions into solution,remain with a negative charge, and thus to adsorb kations. Itdoes, in fact, now take up alkali but not acid. These effects areall much increased by the presence of a little platinum in the char-coal, which is not surprising-indeed it would be useful to knowthat the effects all occur quite definitely in the entire absenceof any platinum. Other observers have found that alkali can betaken up by charcoal which had been heated in air to 400".Frumkin says that different forms of oxygen union must exist(compare Schilov, above), one of which can send hydrions intosolution in presence of water.While these phenomena of ionic exchange are very interestingand probably occur by the mechanism which Prumkin suggests,they cannot give the whole picture of charcoal adsorption : indeed,the phenomenon may be a rather specialised one.H. J. Phelpsand R. A. Peters12 showed that pure ash-free charcoal adsorbs weakorganic acids and bases predominantly in the form of un-ionisedmolecules, the adsorption of acids decreasing with increasing pH10 Kolloid-Z., 1930, 52, 107; A., 1108; N. Schilov and K. Tschmutov,2. physikal. Chcm., 1930, 148, 233 ; A . , 991 ; N. Schilov, H. Schatunovskaja,and K.Tschmutov, ibid., p. 211; 150, 31; A., 1364.l1 Kolloid-Z., 1930, 51, 123; A . , 683; B. Bruns anti A. Frumkin, 2.physikal. Chem., 1929, 141, 141; A., 1929, 640; 1930, 147, 125; A . , 684;R. Burstein and A. Frumkin, ibid., 1929, [A], 141, 158; -4., 1929, 640; R.Burstein, ibid., p. 219; A., 1929, 640.l2 Proc. Roy. SOC., 1929, [ A ] , 124, 554; A . , 1929, 1000GENERAL AND PHYSICAL CHEMISTRY. 41and that of bases increasing in approximate accordance with thechange in the number of undissociated molecules present. TheFrumkin or Schilov mechanisms could be applied to explain theadsorption of the acids, but not that of bases as well. H. J. Phelps l3has found that two distinct phenomena, kation exchange in thesurface, and adsorption of un-ionised molecules, both play a partin the adsorption of weak electrolytes by fullers’ earth.Discussion of J.J. Thomson’s principle that “ if surface tensionincreases as the chemical action goes on, the capillarity will tend tostop the reaction” has been revived by H. Freundlich.14 Thereaction CH,Br*CH,*NH, =: NH(CH,), + HBr and its reversereaction, taking place at the surface of charcoal, were studied invarious solutions, neutral, acid, or alkaline, and the adsorptionsof the various bases and salts concerned were determined. Theinfluence of the charcoal could be correctly predicted, by Thornson’srule, from the surface tension lowerings indicated by the correspond-ing adsorptions. An interesting example of the displacement ofa chemical equilibrium a t an interface may here be referred to:D.Deutsch l5 found that solutions of indicators near to the changingpoint alter in colour when emulsified with an indifferent liquid, andreturn to their original state when the phases separate again.Chemical Kinetics : Chin Reactions.The prominent part played by the chain-reaction mechanism l6in the processes of chemical change has become very evident duringthe last few years. The conditions determining the starting andstopping of reaction chains are becoming more clearly understood,and, incidentally, the canonical classification of reactions intodefinite ‘‘ orders ” is losing much of its sigdcance.The criteria by which a chain reaction may be recognised are asfollows : (I) in photochemical reactions, an abnormally greatquantum yield ; (2) in thermal reactions, a retardation of the changeby a decrease in the dimensions of the vessel, allowing a smallerpath for chains to traverse before reaching the wall ; (3) accelerationof the reaction, in some circumstmces, by the presence of an inertgas-essentially the inverse of (2) ; (4) an abnormal influence of theconcentrations of the reacting substances on the rate, due to thecircumstance that the concentrations affect, not only the numberof chains starting in unit time, but also the successfulness of theirpropagation ; ( 5 ) a rate of reaction considerably greater than mightH.Freundlich and F. Juliusberger, 2. physika2. Chem., 1930, 146, 321 ;l3 Chem. and Ind., 1930, 49, 516 (Proc.of Biochem. SOC.).A., 552; H. Freundlich, J., 1930, 164; A., 687.l5 For references, see idem, ibid. l6 See Ann. Reports, 1927.B42 HINSHELWOOD :be expected from a knowledge of the heat of activation and thecollision number ; (6) sensitiveness of the reaction to inhibitors ;(7) in certain examples a very remarkable phenomenon makes itsappearance, namely, an abrupt transition at a certain concentrationfrom negligibly slow reaction to explosion. It must be emphasisedthat all these characteristics are not necessarily or even commonlyshown by the same reaction, but examples of all are known.Which characteristics appear in a given reaction depends upon thelength of the chain, and upon the manner of its starting and stopping.We may tabulate matters as follows : chains may start either(a) in the gas phase or ( b ) at the wall of the vessel.They may bestopped either (a) by a collision in the gas phase with chemicaldestruction of an active molecule or (or’) by a collision in the gasphase with “ physical ” deactivation of an active molecule ; (p) bysimple collision of an active molecule with the wall of the vessel, or( y ) by a chemical reaction at the wall of the vessel, removing anactive molecule.Furthermore, chains may be classified as “energy” chains or“material” chains. In the former, the entities responsible forpropagating the chain are merely excited molecules of a reactantor product, while in the latter some definite new molecular species,active in virtue of its chemical unsaturation, e.g., a chlorine atom ora hydroxyl radical, is the virtual carrier of the energy.It will be convenient to discuss some of the reactions actuallyinvestigated in the light of the above classification.First may be mentioned the continuation of Lind’s work on thecomparison between photochemical reactions of high quantumyield and the corresponding reactions induced by a-particles.Thesynthesis of carbonyl chlorideY17 the chlorination of benzene, andthe oxidation of sodium sulphite by oxygen l8 are reactions inwhich the yield per quantum is nearly equal to the yield per ion-pair over a wide range of experimental conditions. This showsthat, after differently initiated primary processes, similar chains,often of great length, are propagated.The temperature coefficientsof the synthesis of hydrogen chloride by white light and byor-particles have also been found to be identi~a1.l~ It is further to benoted that in the photochemical reaction of hydrogen and oxygenand of carbon monoxide and oxygen the temperature coefficientsincrease with temperature,20 and the reactions deviate markedly17 H. N. Alyea and S. C. Lind, J . Amer. Chem. Xoc., 1930, 52, 1853; A.,18 H. N. Alyea, ibid., p. 2743; A . , 1136.Is S . C. Lind and R. Livingston, ibicl., p. 593; A., 434.20 G. B. Kistiakowsky, Proc. Nut. Acad. Sci., 1929, 15, 194; A . , 1929, 669.871UENERAL AND PHYSIUAL CHEMISTRY. 43from the Arrhenius equation in the region of temperature where thechain length begins to increase by thermal processes following theinitial photochemical act.The thermal decomposition of chlorine dioxide takes place at40” at a rate approximately proportional to the square root of thedioxide concentration and t o the first power of the total pressure.If the velocity exceeds a certain limit, the decomposition becomesexplosive : various gases accelerate the reaction by increasing thetotal pressure.There is ib fairly marked wall influence, whichH. J. Schumacher and G. Stieger2l interpret by assuming thatreaction chains both start and stop at the wall. They suggestC102-+ C10 + 0 as the primary process, but not on very directevidence. The thermal reaction between chlorine and ozone 22appears to involve chains of about lo4 links under normal conditionsof experiment.The net result of the reaction is a catalytic decom-position of the ozone, the rate of which, after an induction period,is proportional to [Clz]~[03]”. The mechanism proposed is asfollows : C10, + 0, = C10, + 0,;C10, + 0, = C10, + 20,; C10 +I n the ideal case of a chain reaction occurring in a long cylindricaltube, all the chains starting in the gas and being broken a t the wall,the rate of reaction should be proportional to the square of theradius of the tube. The ideal conditions are not realised in practice,but a rough approximation to this kind of behaviour is found in theoxidation of methyl alcohol ~ a p o u r . * ~ On the other hand, the rateof oxidation of benzene vapour is almost independent of thedimensions of the vessel until these become very small : thus mostof the chains appear to be broken in the gas.It is also becomingevident that adsorbed gas layers profoundly modify the capacity ofwalls to break chains: this suggests (y), above, as a commonermechanism than (8).The discovery by Chapman that the photochemical combinationof hydrogen and chlorine takes place more slowly in a capillary tubethan in a wide tube shows that the chains end at the vessel wall-Chapman expresses this by saying that the catalyst formed by thelight is destroyed a t the wall. D. L. Chapman and P. P. Grigg,24by a quantitative analysis of the problem, estimate the mean lifeof the “ catalyst ” in the electrolytic gas a t normal pressure to be21 2. physikal. Chem., 1930, [B], 7, 363; A , , 708.22 M.Bodenstein, E. Padelt, and H. J. Schumacher, ibid., 1929, [B], 5,29 R. Fort and C. N. Hinshelwood, Proc. Roy. SOC., 1930, [ A ] , 129, 284;24 J . , 1928, 3233; 1929, 2426; A., 1929, 154; 1930, 46.C1, + 0, = C10 + C10,;ClO, + C10, = C1, + 30,;c10 = c1, + 0,.209; A., 1929, 1394.A., 152944 HINSHELWOOD :of the order sec. under the conditions of their experiments, butto be proportional t o the sensitivity of the mixture over a wide range.They also establish the important fact that the well-known inhibitionof the reaction by oxygen becomes relatively less important thesmaller the containing tube. Oxygen normally breaks the chainsby deactivation in the gas phase : when the radius of the tube issmall enough, wall deactivation is so great that inhibition by oxygenis relatively insignificant.An interesting point in connexion with the action of inhibitorsin photochemical reactions arises in the work of E.J. Bowen andE. L. Tietz 25 on the oxidation of liquid acetaldehyde. In theabsence of inhibitors the reaction rate is proportional to the squareroot of the light intensity: in the presence of the inhibitor thereduced rate is proportional to the first power of the light intensity.The explanation is as follows : The chain-producing substance isperacetic acid, AO,, initially formed from the aldehyde, A, at a rateproportional to [A] [O,] {Intensity), and, in the uninhibited reaction,finally destroyed by a bimolecular process a t a rate proportional to[AO,],.Since the number of chains started must equal the numberbroken, these two rates may be equated ; whence [AO,] oc(1ntens-ity}*, and the total rate of reaction is proportional to this. Whenthe inhibitor is present, the chain-breaking mechanism acts at arate proportional to [AO,][A] instead of [AO2I2 ; whence it followsthat [AO,] and the total reaction rate K (Intensity). Undercertain conditions, the photochemical decomposition of hydrogenperoxide solutions 26 is proportional to (1ntensity)I. If the chainsare initiated by oxygen atoms or hydroxyl radicals, they wouldappear to be broken rather by the recombination of these atoms orgroups than by reaction with a foreign substance.A number of investigations have been devoted to the oxidation ofhydrocarbons and their simple derivatives, including eth~lene,~'benzene,28 acetylene,29 methane,30 methyl alcohol,30 formalde-h~de,~O> 3 l benzaldehyde,31 and ethane.32 Usually the rate isdecreased by diminution in the diameter of the containing vessel,though to varying degrees (see above 23).There is often R more or26 J., 1930, 234; A., 434.26 A. J. Allmand and D. W. G. Style, J., 1930, 590; A . , 715.27 H. W. Thompson and C. N. Hinshelwood, Proc. Roy. SOC., 1929, [ A ] ,2 8 R. Fort and C. N. Hinshelwood, ibid., 1930, [ A ) , 127, 218; A., 709.29 G. B. Kistiakowsky and S. Lenher, J . Amer. Chem. SOC., 1930, 52, 3785;30 R. Fort and C. N. Hinshelwood, Proc. Roy. SOC., 1930, [ A ] , 129, 284;31 P. J. Askey, J . Amer. Cbem. SOC., 1930, 52, 974; A., 547.3n W.A. Bone and S. G . Hill, Proc. Roy. SOC., 1030, [ A ] , 129, 434.125, 277 ; A., 1929, 1243.A . , 1528.A . , 1529GENERAL AND PHYSICAL CHEMISTRY. 45less well-defined ' ' induction period " during which peroxides oraldehydic substances are produced. But the most remarkablecharacteristic is perhaps the influence of the various concentrationson the rate of oxidation. In all cases the influence of oxygen isrelatively small, and in cert'ain circumstances oxygen may actuallyretard the oxidation. On the other hand, the rates increaserapidly with the concentration of the combustible gas, sometimesapproximately as the cube of its concentration. This suggeststhat intermediate oxygenated products (peroxides or aldehydicsubstances) occur, and that the chains are continued when thesecollide with fresh molecules of the combustible gas but are brokenwhen they collide with oxygen.Sometimes, e.g., with methylalcohol, it appears that the deactivating influence of oxygen isexercised principally in the adsorbed layer at the vessel wall. Theexact chemical constitution of the substances responsible for settingup the chains is at present an open question. It should be mentionedthat the oxidation of ethylene is sensitised byBetween 520" and 600°, and above a certain pressure, chains arepropagated in mixtures of hydrogen and oxygen, in such a manneras to give a reaction rate very sensitive to the pressure of bothgases, but especially that of the hydrogen, and to the diameter ofthe vesse1.34 They appear to be broken at the wall, and it has beensuggested that they are initiated by a termolecular reaction,2H, + O,, though this is simply a convenient working hypothesis.At lower pressures the explosion phenomenon referred to under(7) above makes its a~pearance.~~ Between two well-definedlimits of pressure (dependent on the temperature), explosion takesplace, while outside these limits there is relatively slow combination.Between the limits, chains, evidently somewhat different in characterfrom those propagated at higher pressures, are set up, and " branch,"leading to explosion in the manner described by N.Semenov 36 andexemplified in the explosive oxidation of phosphorus and sulphurvapours. The lower pressure limit is probably that where chainsare broken at the wall rapidly enough to prevent their effectivemultiplication by branching, and the upper limit occurs where theyare broken by deactivation in the gas phase.H. N. Alyea and33 R. Spence and H. S . Taylor, J . Anaer. Ciaem. SOC., 1930, 52, 2399; A . ,1000.34 C. N. Hinshelwood and H. W. Thompson, Proc. Roy. SOC., 1928, [ A ] ,118, 170; A . , 1928, 483; C . H. Gibson and C. N. Hinshelwood, ibid., 119,591 ; S., 1928, 960.s 5 H. W. Thompson and C. N. Hinshelwood, ibid., 1929, [ A ] , 122, 610;A., 1929, 403; D. Kopp, A. Kovalsky, A. Sagulin, and N. Semenov, Z.phyeikal. Chem., 1930, [BJ, 6, 307; A . , 299.36 Ibid., 1929, [ B ] , 2, 169; A., 1929, 51446 HINSHELWOOD :F. Haber37 have found that streams of hydrogen and oxygen,meeting a t right angles and mixing in an atmosphere of nitrogen,fail to ignite, under conditions of temperature and partial pressureapparently suitable for the purpose, unless a solid surface is inter-posed in their path.It seems, therefore, that the first centresfrom which the chains are propagated are formed in a surfacereaction. With regard to the nature of the process initiating thechains, two views have been expressed. According to one, hydrogenperoxide molecules are first formed, whereas according to K. %.Bonhoeffer and F. Haber,38 the primary reaction is H, + 0, = 20H.This is followed by OH + H, = H,O + H, and H + 0, + H, =OH + H,O. This scheme is based upon the appearance of theOH bands in the spectrum of hydrogen-oxygen flames and in theabsorption spectrum of steam at 1250", upon an analysis of thevarious reactions thermochemically possible,38u and upon the factthat hydrogen atoms produced in an electric discharge can causehydrogen-oxygen mixtures to explode.It must be remarked,however, that 1250" is as much above the temperature whereexperiments on the rate of combination are made as O", wherehydrogen peroxide can be condensed out of the flame, is below it.Thus the matter must be regarded as not entirely settled.Analogous results have been found by H. W. Thompson 39 for thccombustion of carbon disulphide in oxygen, namely, an upper anda lower pressure limit, between which explosion occurs, and adependence of the explosions on the presence of a solid surface.Thompson also records a number of observations on an inductionperiod, and on the variation of the explosion pressure with surfaceconditions.Similar " limit " phenomena occur in the oxidation of phosphine :the upper limit depends on gas deactivation, and is independent ofthe diameter of the vessel ; while the lower depends on the diameterin the way predicted by theory, assuming wall deactivation.Thelower limit is displaced by ultra-violet light, owing to the productionof minute traces of a substance which exerts an effect analogous tothat of nitrogen peroxide on mixtures of hydrogen and oxygen.*OL. Farkas, F. Haber, and P. Harteck 41 find that small amounts of37 D. Kopp, A. Kovalsky, A. Sagulin, and N. Semenov, 2.physikal. C'hern.,3 8 Ibid., 1928, [ A ] , 137, 263; A . , 1929, 11.380 Compare also E. H. Riesenfeld and E. Wassmuth, ibid., 1930, [A],149, 140; A., 1126. 39 Ibid., 1930, [ B ] , 10, 273.40 R. H. Dalton and C. N. Hinshelwood, Proc. Roy. Soc., 1929, [ A ] , 125,294; A., 1929, 1243; R. H. Dalton, ibid., 1930, [ A ] , 128, 263; A., 1127;K. Clusius and C. N. Hinsholwood, ibid., 1930, [ A ] , 129, 589.1930, [ B ] , 10, 193; A., 1528.4 1 2. Elektrochem., 1930, 36, 711; Natuiwiss., 1930, 18, 266; A,, 554GENERAL AND PHYSICAL CHEMISTRY. 47ammonia sensitise the combustion of hydrogen and of cazbonmonoxide when illuminated by ultm-violet light ; further observ-ations of an analogous kind are recorded by L. Parkas and P.Harte~k.~2B. Topley43 and also Semenov* report the existence of limitsin the oxidation of carbon monoxide in the presence of water vapour.The influence of hydrogen and of water vapour on the ignition ofcarbon monoxide has been studied by V.E. Cosslett and W. E.Garner,a6 and by A. Smithells, H. Whitaker, and T. H ~ l m e s . ~ ~The Occurrence of Free Atoms.As pointed out in an earlier section, activation of molecules forchemical change involves the excitation of the vibrational degrees offreedom, the limiting stage of this process being the resolution of themolecule into atoms. Activation does not always go to this extremelimit. For example, the heat of dissociation, thermally measured,of hydrogen iodide is 69,000 calories, but the heat of activation ofthe process 2HI = H, + I, is only 44,000 calories.In a number ofreactions, however, the activation goes to the limit and free atomsplay a part. This occurs especially in photochemical reactions;but it is not justifiable, without direct evidence, to transfer conclusions drawn from observations of photochemical behaviour tothermal reactions. In recent years many specific mechanisms forchemical reactions have been suggested, involving the participationof free atoms and radicals, the latter sometimes of hitherto unknownstructures. While these suggestions are all of interest, and oftenvaluable as working hypotheses, it is usually desirable to scrutinisethem closely. It would, indeed, be an advantage if specifk evidencewere occasionally more clearly stated.Among the reactions where free atoms have been definitely shownto intervene, those involving halogens are especially important.Further interesting work by A.Berthoud4' and others on thephotochemical isomerisation of docinnamic acid in the presence ofiodine and on the photobromination of unsaturated compoundsyields evidence (e.g., proportionality of rate to square root of lightintensity) that free halogen atoms are formed in these reactions.R. M. Purkayastha and J. C. Ghosh, 48 comparing the thermal and4s Nature, 1930,125, 560; A., 547. la Natumoiss., 1930,18, 443; A . , 1260.44 See ref. 35 (p. 45), second part.46 Trans. Paraday SOC., 1930, 26, 190; A., 708.46 J . , 1930, 185; A., 428.47 He$. Chim. Acta, 1930, 13, 385; A., 718; A. Berthoud and C.Urech,J . Chim. physique, 1930, 27, 201; A., 1260; Helv. Chim. Acta, 1930, 13,437; A., 1136.-48 2. physikal. Chem., 1930, [B], 7, 276, 285; A., 71848 HINSHELWOOD :the photochemical bromination of organic hydroxy-acids, concludethat in the former active bromine molecules, whilst in the latterbromine atoms, are concerned.It is interesting to note that the chlorine atoms formed by thedissociation of iodine chloride will not, apparently, cause combin-ation between chlorine and hydrogen, a normal atom being supposedto result from this dissociation, while atoms in the 3P, state arerequired for the formation of hydrogen chloride.49The theory of Bonhoeffer and Haber that hydrogen atoms andhydroxyl radicals play a part in the combustion of hydrogen hasalready been mentioned.G. B. Kistiakowsky 5O has studied theformation of hydrogen peroxide and ozone by the action of theoxygen atoms which he supposes to be formed when hydrogen-oxygen mixtures are illuminated by light of short wave-length.H. Klinkhardt and W. Frankenb~rger,~~ studying the productionof hydrogen peroxide by the atomic hydrogen formed under theinfluence of the mercury resonance line, assume the processesH + 0, + H,O = H20, + OH and 20H + M = H202 + M, Mbeing a third molecule.The Stern-Gerlach experiment, carried out with active nitrogen, 52gives evidence of a constituent with a magnetic moment correspond-ing to a nitrogen atom in the metastable state (3.5 volts). Theactive nitrogen problem now stands approximately as follows.Kinetic measurements on the whole indicate that the glow-producingdecay depends upon a three-body collision between two atoms anda molecule.Decay can, however, also take place in a non-luminousmanner on the walls of the vessel; and the " poisoning " of thewalls by a foreign substance is necessary for the production of theglow. E. J. B. Willey 53 finds the " order " of the decay processto vary with the state of the walls, and gives other evidence in favourof regarding as wall poisons those substances which favour thepersistence of the luminescence. The actual carrier of the glow isa nitrogen molecule excited to an energy of about 11.5 volts. H.Sponer 64 had supposed this energy to be given to an N, moleculein the process N + N + N, = N,' + N,.But 11-5 volts is greaterthan the dissociation energy of nitrogen (9.1 volts) and thus themolecules cannot be excited in a single act of recombination.G. Cario and J. Kaplan 55 suggest that the ll.5-volt molecules are49 G . K. Rollefson and F. E. Lindquist, J. Amer. Chem. SOC., 1930, 52,51 2. physikal. Chem., 1930, [ B ] , 8, 138; A., 1004.52 L. C. J8ckson and L. F. Broadway, Proc. Roy. SOC., 1930, [ A ] , 127, 678;s4 2. Physik, 1925, 34, 622; A., 1926, 8.55 Ibid., 1929, 58, 769; A,, 1930, 124.2793; A , , 1135. 5o Ibid., p. 1868; A., 871.A., 969. 53 J . , 1930, 336, 1146; A., 524, 838GENERAL AND PHYSICAL CHEMISTRY. 49formed by collisions between a first-formed metastable moleculeof 8 volts energy (3C state) and a metastable atom in the 2P state.This view is supported by the results of Jackson and Broadway.To explain the abnormal distribution of intensity among the bandsof the glow, Cario and Kaplan also assume that interaction betweenmetastable molecules and metastable atoms of 2.4 volts (2D state)gives rise to excited molecules which contribute to the luminescence.The combination of hydrogen atoms should take place in the gasphase in triple collisions 2H + M = H, + M.The process ismuch complicated by wall influences, as with active nitrogen, butobservations appear to confirm the triple-collision hypothesis in ageneral way, though without anything approaching quantitativecompleteness.56 In addition to examples mentioned elsewhere inthis Report, a good deal of work has been carried out on the actualchemical reactions of atomic oxygen, nitrogen, and hydrogenproduced either photochemically or by Wood’s method.57A.Farkas 68 finds that the thermal transformation of para-hydrogen into the equilibrium mixture of ortho- and para- can takeplace at high temperatures as a homogeneous gas reaction. Theorder of the reaction is 1.5. This suggests the mechanism Hzp” +H H + HZortho, the hydrogen atoms which provoke thechange being those produced by the normal thermal dissociation ofhydrogen molecules.A good deal of work has been carried out on chemical actionsin electric discharges. Free atoms sometimes, but not always,play an important part. In interpreting their experiments on the“ cathodic ” combustion of carbon monoxide, Finch and others 59make use of the hypotheses that carbon monoxide molecules areexcited in the discharge, but not actually ionised, and that theprincipal process occurring in the direct oxidation is a triplecollision between a carbon monoxide molecule, an oxygen atom,and a third molecule or an electron.When the electrode “ sputters,”it is supposed that metal atoms are produced and that these combinewith oxygen to form “complexes ” which readily oxidise thecombustible gas. A. K. Brewer and J. W. Westhaver,G* investigat-H. Senftleben and 0. Riechemeier, Physikal. Z., 1929, 30, 746; A . ,57 E.g., H. C . Urey and G. I. Lavin, J . Amer. Chem. SOC., 1929, 51, 3286;A., 1930,46 ; A. Klemenc and F. Patat, Naturwbs., 1930,18, 281 ; A., 554; P.Harteck and U.Kopsch, 2. Elektrochem., 1930, 36, 714; A,, 1388; W.Frankenburger et al., ibid., p. 757; A., 1383.5 8 2. physikal. Chem., 1930, [B], 10, 419.58 G. I. Finch and €3. H. Thompson, Proc. Roy. SOC., 1930, [ A ] , 129, 314;G. I. Finch and W. L. Patrick, ibid., p. 656.6o J. Physical Chem., 1930, 34, 153, 554, 1280; A., 304, 553, 1003.1930, 166; NatU?~$88., 1930, 18, 645; A., 112650 RlNSHELWOOD :ing the relative amounts of chemical reaction produced in differentparts of a discharge? and the influence of foreign gases, concludethat the ion N,+ is the principal agent in the formation of ammoniaor of nitrogen peroxide from their respective elements, atoms beingineffective : the 02+ ion is the chief agent in ozone formation. Agreat variety of entities are formed in an electric discharge,61 thegases mentioned yielding according to circumstances, 02+, 0+,CO+, C+, CO,+, N,+, N+, He+, Hf, neutral atoms, NH, or NH,.Thus it is not to be wondered at that the interpretation of experi-mental evidence is a complicated matter. 0. H. WansbroughJones,62 studying the formation of oxides of nitrogen and of ozoneunder the influence of electrons accelerated by known voltages,concludes, in general agreement with Brewer, that in the formerreaction the excitation of the nitrogen is alone important, theprincipal processes being N,+ + 0, = 2N0 and N+ + 0, = NO,.The Chemistry of Hydrogen an& Hydroxyl Ions.The following new method has been proposed for determiningthe ionic product of water.63 The constant, K , of the equilibriumset up when mercuric oxide, mercury, mercurous bromide, andpotassium bromide are shaken together is measured by analysisof the hydroxyl- and bromine-ion concentrations of the resultingsolution.(1) &HgO(solid) + $Hg(liquid) + $H,O(liquid) + Br‘ =+Hg,Br,( solid) + OH’.The E.M.F. of the cell Hg,HgO(solid),OH’,H,,Pt, correspondingto the processand that of the cell Pt,H,,H+,Br’,Hg,Br,(solid),Hg(liquid),corresponding to the processare measured.(2) and (3) for unit activity of H f or OH’ or Br’ are calculated.sum of processes (l), (2), arid (3) givesSince the free energy of process (1) is RT log aoHIaB,-R1’ log K ,Le., -RTlog K for unit OH’ and Br’ activities, the free energy of (4)(2) $Hg(liquid) + $H,O(liquid) = iHgO(solidj + +H,,(3) &H2 + $Hg,Br,(solid) = HC + Br‘ + Hg(liquid),The values E, and E, of the free energies of processesThe(4) H,O(liquid) = H+ + OH’.61 H. Kallmann and B. Rosen, 2. Physik, 1929, 58, 52 ; 1930, 61, 61 ; A.,1930, 16, 514; H. D. Smyth and E. C. G. Stueckelberg, Helu. Phys. Acta,1929, 2, 303; A., 1930,975; G. I. Lavin and J. R. Bates, Nature, 1930,125,709.Proc. Roy. SOC., 1930, [ A ] , 12’9, 511, 530; A., 1000.63 R. F. Newton and M. G. Bolinger, J . Amer. Chem. SOC., 1930, 52, 921;A., 542GENERAL AND PHYSICAL CHEMISTRY. 51is known. This quantity is also equal to B27 log C G H * ~ ~ ~ - RTlog K,,Le., to -BT log Kw for the unit activities to which the otherterms in the sum refer. Thus Ii, is found. The value obtainedexperimentally was 1-02 x lW4 a t 25’.As Bronsbd has shown, “ acid catalysis ” is not exclusively afunction of the hydrion, i.e., in aqueous solution of the ion H30+ ;and, indeed, Bronsted was led by his experimental studies, as wellas by general theoretical considerations, to propose a new defhitionof an acid, namely, any substance which may lose a proton. Thismeans that the method for the determination of hydrion concentr-ation by observation of the catalytic effect on a reaction velocitymust be used with circumspection. It is interesting, however, thatJ. N. Bronsted and C. Grove 64 have now found the hydrolysis ofdimethylacetal to proceed a t a rate directly proportional to theconcentration of the ion H,O+, and not to be catalysed appreciablyby other “ acids.” This reaction is therefore useful for the determin-ation of hydrion concentration.In connexion with acid and basic catalysis, an interesting pointemerges from considerations put forward by C. K. I n g ~ l d , ~ ~ whodistinguishes two factors determining the ease of hydrolysis ofesters, namely a ‘‘ polar ” effect and a “ steric ” effect. No relationcan be traced between the rate of hydrolysis of different esters andthe “ polar ” properties of substituent groups contained in them :this he attributes to the fact that the different shapes of the molecules( b ‘ steric factor ”) mask any regularity. The relative influence of anegatively charged hydroxyl and a positively charged hydrion incatalysing the hydrolysis of the same ester should be independentof the shape of the molecule, but not of the “ polarity.’’ And, infact, Ingold finds that the ratio of the velocity coefficients forcatalysis by hydrion and hydroxyl ion respectively for a series ofesters shows a regular trend with changing polarity of substituentgroups.C. N. HINSHELWOOD.6 4 J . Amer. Chem. Soc., 1930, 52, 1394; A., 711.66 J., 1930, 1032; A,, 868

ISSN:0365-6217    

DOI:10.1039/AR9302700011

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

INORGANIC: CHEMISTRYALTHOUGH no work of outstanding importance has appeared, thereis a, distinct improvement in the papers on Inorga,nic Chemistrywhich have been published during the past year, both as regardsthe quality of the work and the conciseness of its presentation.A tendency is apparent in some quarters towards duplication oreven triplication of publication-in journals of different types.This has several undesirable consequences: it swells the bulk ofjournal literature unnecessarily, and it results either in several ab-stracts of what is really the same work or in an abstract of the firstpaper only, which is itself usually more or less in the nature of anabstract.Atomic Weights and Separation of Isotopes.It begins to look as though hydrogen may be the only simpleelement.Carbon,l nitrogen,2 and oxygen3 all appear to be com-plex, containing very small proportions of the isotopes C13, N15, and017 and 0l8. The oxygen isotopes are only present to the extentof about 1 in lo4 and 1 in 1250 respectively, which is too small tointroduce appreciable error when oxygen is taken as the basis of theatomic-weight ~ystern.~ The divergence of the atomic weight ofoxygen from 16 is about 1-25 parts in ten th~usand.~K. P. Jakovlev 6 has reviewed the methods which have been usedfor the separation of isotopes and has himself designed an apparatusby which it is possible, by using a bundle of positive rays, to separatesmall quantities of isotopes in a pure condition.Potassium.-According to H. H. LowryY7 the atomic weight ofpotassium from plant ash is normal, and this lends no support toa remarkable result recorded by F.H. Loring and J. G. F. Druce.8Nitrogen ; Phosphorus.-The method of limiting densities applied1 A. S. King and R. T. Birge, Astrophys. J . , 1930, 72, 19; A., 1931, 15.2 $3. M. Naud6, Physical Rev., 1930, (ii), 36, 333; &4., 1232; G. Herzberg,R. Mecke and K. Wurm, 2. Physilc, 1930,61, 37; a., 615; E. Ruchardt,2. physikal. Chem., 1930, [ B ] , 9, 43; A., 1084.Naturwiss., 1930,18, 534; A., 975.4 E. Moles, Anal. Fis. Quim., 1930, 28, 127; A., 515.F. W. Aston, Nature, 1930, 126, 953.ti 2. Physik, 1930, 64, 378; A . , 1337.J . Arner. Chem. SOC., 1930, 52, 4322.8 Chem. News, 1930,140, 34INORGANIC! CHEMISTRY. 53to ammonia9 and to phosphine1O has given values of 14.009 and30.977 for the atomic weights of nitrogen and phosphorus respectively.Arsenic.-Analysis of arsenic trichloride gave the value 74.936 rt0.001 for the atomic weight of arsenic.llVanadium.-The atomic weight of vanadium was found to be50.947 from a determination of the ratio VOC1, : 3Ag.12I'antcaZum.-K.R. Krishnaswami,13 from a careful determinationof the ratios TaBr, : 5Ag : 5AgBr and TaCl, : 5Ag : 5AgC1, findsthe atomic weight of this element to be 181.36.Sulphur.-By synthesising silver sulphide from its elements,0. Honigschmid14 finds the atomic weight of sulphur to be32.0685 & 0-0006.Molybdenum-The mass spectrum of the carbonyl shows thatmolybdenum has 7 isotopes. From the mass numbers, the approxi-mate abundances, and the packing fractions, the value 95-97 &- 0.05is calculated for the atomic weight of m01ybdenurn.l~Chlorine.-According to A.F. Scott and C. R. Johnson,lG adirect determination of the solubility of silver chloride in 0-1M-nitric acid a t 0.5" shows that the value accepted by Honigschmidand Chanl' is too low, so that their determination of the atomicweight of chlorine is about 0.001 unit too high.Rhenium.-The atomic weight of rhenium (188.7) appears for thefirst time in the Report of the German Commission on atomicweights.ls Methods available for determining this value havebeen critically examined by 0. Honigschmid and R. Sachtleben,lgwho obtain the value 186.31 0.02 from the ratio AgReO, : AgBr.Intensive Drying.A paper of considerable importance in connexion with the problemof intensive drying has appeared,20 in which it is shown that waterhas an abnormally high activity when present in traces in suchliquids as benzene, in which its solubility is very low.DecreaseE. Moles and T. Batuecas, Anal. pis. Quirn., 1930, 28, 871 ; A., 1357.lo M. Ritchie, Proc. Roy. SOC., 1930, [ A ] , 128, 551 ; A., 1104.l1 J. H. Ki.epelka, J . Czech. Chem. Comm., 1930,2,256; A., 976.l2 A. F. Scott and C. R. Johnson, J . Amer. C?bem. SOC., 1930,52, 2638; A.,l3 J., 1930,1277; A., 975.l4 2. Elektrochem., 1930, 36, 689; A., 1337.l6 F. W. Aston, Nature, 1930,126, 348 ; A., 1338.lo J . Amer. Chem. Xoc., 1930, 52, 3586; A., 1337.l7 2. anorg. Chem., 1927, 163, 315; A., 1927, 806.*1084.M. Bodenstein, A. Hahn, 0. Honigschmid, and R. J. Meyer, Ber., 1930,63, [B], 1; A., 269.l9 2. anorg. Chem., 1930, 191, 309; A., 1338.2o (Miss) E. J. Greer, J . Amer. Chem. SOC., 1930,52, 4191 ; A., 1931, 3454 BASSETT :in the vapour pressure of such liquids by intensive drying can beexplained by the removal of the abnormally high partial pressure ofthe water, and there is no need to assume any catalytic effect of thelatter on an inner equilibrium.Superconductors.Niobium 21 and ruthenium 22 have been shown to become snper-conducting between 8-74" and 8.18" Abs. jand at 2-04" Abs.,respectively. Titanium has almost become a superconductor at1.16" Abs., and it is considered that many if not all metals arelikely to show superconductivity if the temperature is low enough.23The conductivities of many metals and alloys have been examineddown to temperatures as low as 1-43' Abs., and several supercon-ducting alloys were foundY24 of which Rose's alloy showed aresistance-temperature hysteresis.25 Titanium nitride (1.2" Abs.), vanadiumnitride (1.2"), and the carbides of molybdenum (7"), niobium (lo"),and tantalum (9") become superconducting at the temperaturesshown.26 Niobium carbide shows this phenomenon at a highertemperature than is known for any other substance.X-Ray8 and Chemical Problems.It is more and more becoming standard practice to supplementmetallographical and other investigations of a chemical natureby an X-ray examination of the substances which are being studied.Zirconium dioxide 27 has been shown in this way to occur in threedifferent varieties. According to W.Morris-Jones andE. G. Bowen,2* the compound SnSb, which forms good cubiccrystals, has a sodium chloride lattice, and so is ionic in structureand probably contains tervalent tin.Co-ordination.Equations have been developed by F. J. Garrick 29 which enablehim to calculate the maximum co-ordination numbers of uni- and21 W. Meissner and H . Franz, 2. Physik, 1930,63, 668; A., 1102.22 J. C. McLennan, Nature, 1930, 125, 168; A., 281; J. C. McLennan,J. F. Allen, and J. 0. Wilhelm, Trans. Roy. SOC. Canadu, 1929, (iii), 23, 111,383 ; A., 632.23 W. Meissner, 2. Physik, 19$0,60, 181; A , , 631.24 J. C. McLennan, L.E. Howlett, and J. 0. Wilhelm, Trans. Roy. SOC.Cuncbda, 1929, (iii), 23,111, 287; A , , 631 ; W. J. de Haas, E. van Aubel, andJ. Voogd, Proc. K. Akad. Wetensch. Amsterdam, 1930, 33, 268; A., 676.25 J. C. McLennan, Nature, 1930,125, 447; B., 610.26 W. Meissner and H. Franz, Ncrturwis~., 1930, 18, 418; A., 846; 2.27 W. M. Cohn and S. Tolksdorf, 2. physikal. Ghem., 1930, [ B ] , 8, 331 ; A .,t 8 Nature, 1930,126, 846; A., 1931, 33.29 PhiE. Mag., 1930, [vii], 9, 131; 10, 76, 77; A . , 276, 1096.Phyeik, 1930, 65, 30; A., 1507.1099INORGANIC CHEMISTRY. 55bi-valent kations. The assumption is made that the most stablecomplexes are those in which the electrostatic energy is a maximumand the values so calculated are on the whole in good agreementwith Sidgwick's rule.Corrosion and Passivity of Metals.Much work on the anodic passification of metals has been publishedduring the past year.30 The transparent film responsible for thepassivity of iron made anodic in dilute sulphuric acid has beenisoIated.31 Potential-time curves have been constructed for anumber of iron alloys, as well as for iron and aluminium, in order tostudy the effect of various treatments of thg metal on its passivity?2The capacity for different anions to penetrate the protective filmhas been examinedF3 whilst the influence of acids in passivity andcorrosion and the reproducibility of results in corrosion work havebeen c0nsidered.~4 The theoretical aspect of corrosion has also beendealt with by F.Todt.35 A new explanation of the passivity ofiron based on its behaviour as a higher oxide electrode has beenput f o r ~ a r d .3 ~ ~Group 0.The m. p.'s of krypton and xenon are -157.0" 0.5" and - 112-0"&04" respectively. Solid krypton appears to have a transitionpoint at about -185".36 The m. p.'s of hydrogen, neon, andnitrogen have been determined for pressures up to 5000 kg. persq. cm., and those of argon up to 3400 kg. per sq. Thesolubilities of helium, neon, and argon for the range 15-37" havebeen determined in water and several organic solvents.38Group 1.The inner equilibrium of the a- and the p-form of hydrogen hasbeen considered by A. S m i t ~ . ~ ~ The conversion of active hydrogen30 W. J. Miiller, L. Holleck, I(. Konopicky, and W. Machu, Monats?~, 1929,52, 409, 426, 442, 463, 474; A., 298.31 U.R. Evans, Nature, 1930,126,130; A., 1126.32 L. C. Bannister and U. R. Evans, J., 1930,1361 ; A., 999.33 S . C. Britton and U. R. Evans, ibid., p. 1773; A., 1268.a4 U. R. Evans, ibid., p. 478; B., 462; Amer. Electrochem. SOC., May,36 2. physikal. Chem., 1930, 148, 434; A., 1126.36a J. F. Chittum, J. Physical Chem., 1930,34,2267; A., 1627.36 K. Peters and K. Weil, 2. physikal. Chem., 1930, 148, 27; A., 986;F. J. Allen and R. B. Moore, J. Arner. Chem. SOC., 1930, 52, 4173; A., 1608.37 F. Simon, M. Ruhemann, and W. A. M. Edwards, 2. physikal. Chem.,1930, [ B ] , 8, 331; 7, 80; A., 403,633.38 A. Lannung, J. Amer. Chem. SOC., 1930,52, 68; A., 406.8e Proc. K . Akad. Wetensch. Amsterdam, 1929, 32, 1118; A ., 293; Physikal.1930, Advance Copy; B., 463.Z . , 1930,31,172,178; A,, 39356 BASSETT :into molecular hydrogen is greatly delayed if the walls of thedischarge tube are washed with phosphoric acid. Metallic leadyields it volatile hydride by the action of active hydrogen.*O Ipatievhas continued his investigations of the displacement of metals fromsolutions by hydrogen under high pressure, by investigating thecase of arsenic.41 The behaviour of aqueous solutions of a numberof nitrates towards hydrogen under pressure has also beenas well as the displacement of lead from its organo-metallic COM-pounds .BSmall quantities of any of the alkali metals can be obtained byheating such salts as the chromate or dichromate with excess ofzirconium in a vacuum:44The vapour density of sodium shows that some Na, molecules arepresent.45 Metallic sodium and silver iodide or chloride in liquidammonia solution react sharply in accordance with the equationNa + AgX = NaX + Ag.46 Pure sodium hydride has beenprepared 47 as fine white needles by the interaction of hydrogen andsodium vapour a t 400-450".Its heat of formation has beendetermined.The melting-point curve of NaC1,2H2Q has been followed up topressures of 12,000 bars (c. g. s. atmospheres). It passes through amaximum at 25.8" and 9500 bars. The melting point is + 0.1" at1 bar pressure.48Anhydrous sodium sulphate appears to exist in five differentand the existence of three forms of potassium nitrate hasbeen e~tablished.~OThe reaction between sodium hydroxide and metallic oxidesxRQ, + 2NaOH --+ Na,R,O(,,+ + H,O has been followed bydetermining the water formed and also, by means of suitable40 H.von Wartenberg, G . Schultze, and E. Muller, 2. physikal. Clhem., 1930,[B], 6, 261 ; A., 302.41 V. Ipatiev, G. Razubaiev, and V. Malinovski, Ber., 1930, 63, [ B ] , 166,2812; A., 1930, 306; 1931, 52.42 V. Ipatiev and B. Muromtzev, ibid., p. 160; A., 306.43 V. N. Ipatiev, G. A. Razubaiev, and I . I?. Bogdanov, J. Buss. Phys.44 J. H. de Boer, J. Broos, and H. Emmens, 2. anorg. Chem., 1930, 191,46 W. H. Rodebush and E. G. Walters, J. Amer. Ckem. SOC., 1930,52,2654;40 W. M. Burgess and E. H. Smoker, ibid., p. 3573; A., 1386.47 H. Hagen and A. Sieverts, 2. anorg.Chem., 1930,185, 239; A , , 307.4 8 L. H. Adams and R. E. Gibson, J. Amer. Chem. SOC., 1930,52,4252 ; A .49 F. C. Kracek and R. E. Gibson, J. Physical Chem., 1930, 34, 188; A . ,li0 F. C. Kracek, ibid., p. 225; A . , 402.Chem. SOC., 1929,61, 1791; A., 428; Ber., 1930,63, [ B ] , 335; A., 463.113; A . , 1136.R . , 1104.1931, 40.281; F. C. Kracek and C. J. Ksanda, ibid., p. 1741; A., 1099INORGANIC CHEMISTRY. 57dissolution, the quantity of metallic oxide which has entered into thechange. By using excess of alkali hydroxide and of metallic oxidein different experiments, the compounds richest and poorest inalkali can be established with a large measure of certainty. Anumber of compounds derived from the oxides of Si, Ti, Zr, Ce, Al, Fe,and Cr have been characterised in this way.51A careful revision of most of the older work on the polysulphidesof sodium has been carried out by T.G . Pearson and P. L. Robinson.52The mono-, di-, tri-, tetra-, and penta-sulphides all exist both in theanhydrous condition and hydrated.The compounds K2PbCu(N02) 6, K,PbNi(NO,) 6, and K2PbCo(N02) 6are obtained by precipitation with potassium nitrite of mixed solu-tions of lead and copper (or nickel) acetates or of lead and cobaltnitrate.% X-Ray examination shows that they aU have a cubiclattice very similar to that of K,CO(N~,)~,~H,O, from which it isconcluded that the 3 molecules of water in the latter compoundare zeolitic in character and entangled in the crystal lattice. It isconsidered that the above lead compounds contain ions of the type[M(N02)6]””, where M is Cu, Co, or Ni.Several complex saltsderived from potassium manganese (cobalt or zinc) double oxalatesby replacement of C20, groups by (NO,),, (CNS),, or S203 have beendescribed. 54From an examination of the system iodine-potassium iodide,it is concluded that neither the tri-iodide nor any other polyiodideof potassium can exist as stable solid above 25”.s5 In the case ofcesium, the tetraiodide and the tri-iodide can separate either frommelts or from aqueous solutions, but the pentaiodide does notexist .56German carnallite contains, on the average, 0.02% of rubidiumchloride and 0~0002~0 of cesium chloride, and full details havebeen published 57 of a comparatively rapid and simple method bywhich practically the whole of this can be recovered in a high state ofpurity.The whole of the rubidium and cesium with some potassiumis precipitated as silicomolybdate from an acid solution of the once5 1 J. D’Ans and J. Loffler, Ber., 1930, 03, [B], 1446; A., 1005.G2 J . , 1930, 1473; A., 1136.53 A. Ferrari and C. Colla, Atli R. Accad. Lincei, 1930, [vi], 11, 755; A.,54 R. Scholder and C. F. Linstrom, Ber., 1930,83, [B], 2828 ; A., 1931, 66.b 5 T. R. Briggsand W. F. Geigle, J. Physical Chem., 1930,34,2250; A., 1521.56 T. R. Briggs, J. A. Greenwald, and J. N. Leonard, ibid., p. 1951; A.,1374; T. R. Briggs, ibid., p. 2260; A., 1522.G7 G. Jander and H. Faber, 2. anorg. Chem., 1929,179,321 ; B., 1929,641 ;G. Jander and F.Busch, ibid., 1030,187, 165; 104, 38; A., 1930, 435; 1931,49.138858 BASSETT :recrystallised carnallite. The molybdenum is removed by volatilisa-tion as oxychloride in a current of hydrogen chloride. If in thefirst instance only enough silicomolybdic acid is added to precipitate10% of the total rubidium and caesium, the precipitate contains allthe caesium and practically no potassium; the remaining rubidiumis thrown down by a second addition of silicomolybdic acid. Bycarrying out the silicomolybdate precipitation thus in two stages,the separation of pure caesium and rubidium preparations is greatlyfacilitated.The pentaborates of potassium, rubidium, and casium,5B203 ,l&0,8H,O, form isomorphous (orthorhombic) crystals. 58With the exception of the lithium compound, nitrides of the alkalimetals are difficult to prepare, and in no case had it been demon-strated that they are of the type M,N.Under the influence of theglow discharge, the alkali metals and their amalgams take upnitrogen. When this occurs at room temperature the compoundformed is practically entirely a ~ i d e , ~ ~ but at higher temperaturesand with excess of alkali metal, nitride formation is favoured.60 Asmall amount of nitride is formed during the thermal decompositionof alkali azides, and it has now been shown that rubidium and caesiumnitrides formed in this way have the formule Rb,N and CS,N.~~H. J. S. King has prepared a large number of ammines of cupricsalts of monobasic acids, including some of cupric iodide.61a Theammines and ammine hydrates of cupric selenate 62 and selenite 63have been prepared and examined, and a large number of alkalicupric carbonates are stated to exist.64Some interesting studies of the dehydration of single crystals ofcopper sulphate pentahydrate have been made by W.E. Garner andM. G. Tanner.65The solubilities of silver chloride, bromide, and iodide in methyland ethyl alcohols have been determined by an electrochemicalmethod,66 and it is suggested that the solubility of silver iodide inacetone solutions of sodium iodide is due to the formation of ananion [I(IAg),]'. Several sodium argentothiosulphates and theacid H(AgS,O,),H,O have been prepared.67s8 A. P. Rollet and L. And&, Compt. rend., 1930,191, 567; A., 1386.59 W.Moldenhauer and H. Mottig, Ber., 1929,62, [ B ] , 1954; A . , 1029, 1247.oo H. Wattenberg, ibid., 1930,63, [B], 1667; A., 1137.61 K. Clusius, 2. anorg. Chem., 1930, 194, 47; A., 1931, 50.61@ J., 1930, 2307; A., 1536.62 L. C. Hurd and V. Lenher, J . Amer. Chem. SOC., 1930,52,3857 ; A., 1536.63 L. C. Hurd, G. I. Kemmerer, and V. W. Meloche, ibid., p. 3881 ; A., 1536.64 A. Cocosinschi, Bull. A c d . Sci. Roumaine, 1929,12,19; A., 307.135 J., 1930, 47; A., 428.6 6 F. K. V. Koch,ibid., pp. 1561,2386; A., 1107, 1511.6'1 H. Bahea,&bicE., 1929,2763; A., 176INORGANIC CHEMISTRY. 59Cryoscopic measurements of the molecular weight of gold dis-solved in various metals show that it is unimolecular between400" and 1550".68A number of triple bromides of rubidium, tervalent gold, andcopper, cadmium, mercury, thallium, bismuth, or antimony havebeen prepared and their properties described .69Aurous chloride carbonyl is formed quantitatively from aurouschloride and carbon monoxide in benzene a t 15" or from auricchloride in tetrachloroethylene at 130-140".It has M , 223 (calc.,260) in freezing benzene, and dissociates in a vacuum or in hotsolvents to give pure aurous chloride. It reacts with nitrogenousbases, the carbonyl group being displaced by 1 mol. of ba~e.~OGroup I I .A question, which has nowadays lost the interest it once had,has been revived by P. Pfeiffer, T. Fleitmann, and R. Hansen 71 ina discussion as to whether beryllium and magnesium are betterclassed with zinc and cadmium or with calcium, strontium, andbarium.The question is considered with reference to the degreeof hydration and ammoniation of the salts of various aromaticsulphonic acids, and it is concluded that beryllium and magnesiumare better classed with zinc and cadmium. A number of such salts ofnickel, copper, zinc, and cadmium were also made. The berylliump-toluenesulphonate and p-naphthalenesulphonate have six mole-cules of water of crystallisation, although the a-naphthalenesul-phonate only has four and the ammines never have more than 4mols. of ammonia. The first two salts are considered to be the firstcertain cases of salts containing 6-co-ordinated beryllium. It isplain that alternative explanations are possible, however.Pure beryllium can be deposited electrolytically from solutions ofits anhydrous salts in liquid ammonia.72The molecular weight of magnesium dissolved in other metalscorresponds to a monatomic molecule above 700".73 Anhydrousmagnesium perchlorate 74 and barium oxide 75 have been recom-68 E. S . Burkser, S. G. Rublov, and A. M. Scharnovsky, 2. anorg. Chem.,7 O M. S. Kharasch and H. S. Isbell, J . Amer. Chem. SOC., 1930, 52, 2919;71 J . p r . Chem., 1930, 128, 47; A., 1536; P. Pfeifk, T. Fleitmann, andH. S. Booth and G. G. Torrey, J . Amer. Chem. Soc., 1930, 52, 2581; A.,A. Jouniaux, Bull. SOC. chim., 1930, [iv], 47, 682; A., 1243.1029,185, 144; A., 176.A., 1277.T. Inoue, 2. anorg. Chem., 1930,192,346; A., 1390.1004.78 A. Jouniaux, Bull.SOC. china., 1930, [iv], 47, 686; A., 1243.74 S. Lenher and G. B. Taylor, I d . Eng. Chem. (Anal.), 1930,2,58; A., 568.7 5 H. 8. Booth and L. H. McIntyre, ibid., p. 12 ; A., 66860 BASSETT :mended as drying agents, It is concluded from spectroscopicobservations that in a magnesium arc burning in wafer vapour thereis not merely displacement of hydrogen by the magnesium, but alsoa second reaction resulting in the simultaneous formation of mag-nesium oxide and hydride.76 In continuation of his studies of oxidehydrates, Huttig has published papers dealing with the oxides ofberyllium, 77 magnesium,78 calcium,7g strontiurn,sO and cadmium.81A number of points connected with the technique of such investiga-tions, such as the measurement of water-vapour pressure of hydrox-ide gels, have been discussed.82 It has been shown that when due at-tention is paid to the preparation of pure products, the hydratedperoxides of calcium, strontium, and barium all correspond to the for-mula M0,,8H,0.83 Several papers have been published on magnesiumcarbonate^,^^ and it is said that a very unstable monohydrate ofcalcium carbonate exists besides the much more stable hexah~drate.~SThe calcium aluminates have been investigated by several workers.86The action of nitrogen peroxide on calcium carbonate, lime, andcalcium phosphate has been investigated, and that of sulphurdioxide on calcium carbonate and phosphate.The use of calciumcarbonate in the recovery of nitrous gases is suggested.*' Thesolubilities of several radium salts have been determined.88The supposed allotropic changes undergone by zinc and bismuthare really due to impurities, but thallium and cobalt undergoreversible changes respectively at 225.2" and at 444" and 1128°.897 6 G.Piccardi, CTazzetta, 1930, 60, 337; A., 1006.7 7 G. F. Hiittig and K. Toischer, 2. anorg. Chem., 1930, 190, 364; A . , 996.7 8 G. F. Huttig and W. Frankenstein, ibid., 185, 413; A . , 293.7 9 G. F. Hiittig, A. Arbes, Z. Herrmann, and C. Slonim, ibid., 191, 161 ; A.,1372.G. F. Huttig and A. Arbes, ibid., 192, 226; A., 1373.81 G. F. Huttig end R. Mytyzek, ibid., 190,353 ; A., 996.G. F. Huttig and K. Toischer, KoEEoidchem. Beih., 1930,31, 347; A . , 1373.83 C . Nogareda, Anal. Fig. Quim., 1930,28,461; A ., 1006.84 H. Menzel, A. Bruckner, and H. Schulz, 2. Elektrochern., 1930, 36, 188;A . , 718; H. Menzel and A. Bruckner, ibid., p. 63 ; A . , 436; G. F. Hiittig andW. Frankenstein, 8. anorg. Chem., 1930,185, 413; A . , 293.8 5 F. Krauss and W. Schriever, 2. anorg Chem., 1930, 188, 259; A . ,718.86 S. Nagai and R. Naito, J. SOC. Chem. Ind. Japan, 1930,33, 17 ; A., 436 ;T. Thorvaldson and N. S. Grace, Canad. J . Ree., 1929, 1, 36; A., 436;G. Assarson, 2. anorg. Chem., 1930, 191, 333; A., 1262; A. Travers andJ. Sehnoutka, Ann. Chim., 1930, [XI, 13,265; A., 872.87 E. Briner, J. P. Lugrin, and R. Monnier, Helv. China. Acta, 1930, 13, 64,76, 80 ; A., 436.8 8 0. Erbacher, Ber., 1930,63, [B], 141 ; A., 406.8 9 A. Schulze, 2. Metallk., 1930, 22, 194, 308; B., 1073; 2.tech. Physik,1930,11, 16; A., 1355INORGANIC CHEMISTRY. 61Zinc hydroxide exists in five different crystalline formsg0 and anumber of well-defined basic salts are formed by prolonged actionof the hydroxide or oxide on solutions of zinc salts.g' The complexnature of the curious fractional hydrates of zinc chloride is indicatedby the solid solutions containing cobalt chloride which they form?2The degree of association of cadmium iodide and of mercuric chlorideand bromide in acetone solution has been determined, as also thesolubilities, which are lower than those reported by previousworkers .93The solubilities of cadmium in its molten halides, of mercury inmercuric iodide, and of zinc and magnesium in their respectivechlorides have been determined.The solution of cadmium in moltencadmium chloride is due to formation of a subchloride which is onlystable whilst the mixture is liquid.94The conditions under which tetramminomercuric salts can beformed have been discussed, and a number of these salts, as well assome diammino-salts, have been prepared.95 The action of am-monia on the compounds HgC4,2NH3 and HgBr2,2NH3 has beenstudied, and the compounds Hg2NBr and Hg$C1,H20 prepared.96Unlike most bi- and ter-valent metals, mercury and bismuth do notform inner complex phenoxides with 8-hydroxyquinoline ; variouscompounds are formed, however, and a number have been prepared,such as those formulated as [HgC4(CgH,0N)]C1 andBiC13( CgH,ON,HC1),,EtOH .97Group I I I .F.Faltis 98 has put forward views with regard to the structure ofthe boron hydrides involving cyclic structures for the higher members.E. Wiberg 99 considers that boron is quinquevalent towards hydrogenand ip so in B,H,, the two boron atoms being doubly bound.Aluminium and cerium borides on treatment with acids give smallyields of the same boron hydrides as are furnished by magnesiumb0ride.l Beryllium boride has the advantage over magnesiumW. Feitknecht, Helv. Chim. A&, 1930,13,314; A., 700.O L Idem, ibid., p. 22; A., 436.92 H. Bassett and H. H. Croucher, J., 1930, 784; A,, 1251.Q8 C. Zapata y Zapata, Anal. Pis. Quim., 1930,28, 603; A., 1362.94 G. von Hevesy and E. Lowenstein, 2. anorg. Chem., 1930,187, 266; A.,95 E.Weitz, K. Blasberg, and E. Wernicke, ibid., 188,344; A., 719.s6 M. Franqois, Compt. rend., 1930, 190, 125, 744, 1607; Bull. Soc. chim.,97 L. Dede and W. Hessler, 2. anovg. Chem., 1930,188, 325; A , , 719.98 Ibid., 187, 369; A., 624.99 Ibid., p. 362 ; A., 624.437.1930, [iv], 47, 166,569, 826; A., 307,667,1006, 1138, 1262.B. D. Steele and J. E. Mills, J . , 1930, 74; A . , 43782 BASSETT :boride for the preparation of boron hydrides because it furnishesa gas free from silanes which are troublesome to remove.2 B4H1,has now been prepared in quantity, and its reactions with hydrogenchloride, sodium amalgam, and ammonia studied in detail.3Phenylborine, BH2Ph, and boronbenzene, BPh : BPh, aredescribed by E. Pace.4 The distillation of boric acid in steamhas been studied by G.Banchi and M. Giann~tti.~ Structuresfor the various boric acids and borates have been put forwardwhich fall into line with those now customary for poly- and hetero-poly-acids, with a central boron atom to which boric acid residuesare co-ordinated.6 They seem preferable to the long-chain formuhproposed by E. Wiberg.' By electrolysis of fused borates and borate-fluoride mixtures, amorphous boron has been obtained as well asborides of many metals of Groups 111, IV, V, VI, and VII.8Fluoroborates other than those corresponding with the formulaMBF, are said to exist.gThe changes undergone by hydrated alumina during dehydrationand heating have been followed by X-ray examination.10A number of spinels, M11M211104 (MI1 = Cu,Mg,Zn,Mn ;MI11 = Al,Fe,Cr), have been prepared by precipitation of themixed oxides or evaporation of mixed nitrates and calcination atabout 800" in each case.ll Anhydrous aluminium alums of thegeneral formula MAl( SO,), are precipitated by addition of hotconcentrated sulphuric acid to the hot concentrated mixed sulphatesolutions.l2Gallium tribromide, tri-iodide,13 and trisulphidel* have beenA. Stock, E. Wiberg, and H. Martini, 2. anorg. Chem., 1930, 188, 32;Idem, Ber., 1930, [B], 63, 2927; A., 1931, 50.A., 720.4 Atti R. A d . Lincei, 1929, [vi], 10, 193; A., 354.6 Ann. Chim. Appl., 1930,20,271,286,296; A., 1361.F. L. Hahn, 2. anorg. Chem., 1930,193, 316; A., 1502.Ibid., 191, 43; A., 1096.8 L. Andrieux, Ann. Chim., 1929, [XI, 12, 423; A., 305.9 A.Travers and L. Malaprade, Bull. SOC. chim., 1930, [iv], 47, 788; A . ,1261.10 W. Biltz, A. Lemke, and K. Meisel, 2. unorg. Chem., 1930,186, 373; A.,399; N. Parravano and E. Onorato, Atti R. Accad. Lincei, 1929, [vi], 10,475; A., 437; G. F. Huttig and 0. Kostelita, 2. unorg. Chem., 1930, 187, 1 ;A., 543.11 L. Passerini, Gaxzetta, 1930, 60, 389; A., 1007.12 N. Schischkin, 2. anorg. Chem., 1930,189, 289; A., 720.13 W. C. Johnson and J. B. Parsons, J . Physical Chem., 1930,34,1210 ; A .,874.14 A. Brukl and G. Ortner, Natumoies., 1930, 18, 393; A., 720; Monatah.,1930, 56, 368; A,, 1537; W. C. Johnson and B. Warren, NUtUWi88., 1930, 18,666; A., 1138INORGANIC CHEMISTRY. 63prepared directly from the elements. By reduction of Ga,S, withhydrogen Gas is obtained, and on being heated in a high vacuum,this breaks up into Ga,S and Ga,S,.Thallic oxide does not appear to form any definite hydrate.15A number of alkali ceric oxalates have been described.16Europium may be separated from samarium and gadolinium asEuSO,, which is insoluble in dilute acid, by electrolytic reductionin presence of su1phate.l' Ytterbium can be similarly separated,practically quantitatively, in one operation as YbSO,,xH,O of 98%purity, from the pink yttria-group oxides containing yttrium anderbium with small amounts of thulium and ytterbium.The Yb"ion is green.l*Samarium di-iodide is best prepared by thermal dissociation ofthe tri-iodide in a high vacuum. On strong heating in a vacuum,SmC1, undergoes the type of decomposition characteristic of lower-valency compounds to give metal and SmCl,.l9The sulphides of a large number of rare-earth metals have beenprepared by heating the chloride or sulphate in a current of hydrogensulphide. They fall into two groups with different crystal lattices anddifferent colours.20 Praseodymium forms two different doublesulphates with ammonium sulphate.21 The solubilities of severalrare-earth salts have been determined.22Group I V .Measurements of parachors and dipole moments have furnished.important evidence for the structure of the compounds of bivalentcarbon, which are shown to be best formulated thus : Carbonmonoxide, CEO ; the isocyanides, R-N"C.23Purified wood charcoal reacts spontaneously with fluorine a tthe ordinary temperature, a variety of carbon fluorides beingl6 G.F. Huttig and R. Mytyzek, 2. anorg. Chem., 1930,192, 187; A., 1373.1% J. 8ttkba-Bohrn and A. Pisafilsek, J . Czech. Chem. Comm., 1930,2, 244;1' L. F. Yntema, J . Amer. Chem. SOC., 1930, S2,2782; A., 1134.1* R. W. Ball and L. F. Yntema, ibid., p. 4264; A., 1931, 51.l@ G. Jantsch, Nuturwiss., 1930,18,166 ; A,, 437 ; G. Jantsch and N. Skalla,2. anorg. Chenz., 1930, 193, 391 ; ri., 1931, 51.20 W. Klemm, K. Meisel, and H. U. von Vogel, 2. anorg. Chem., 1930,190,123 ; A., 874.z1 F. Zambonini and S. Restaino, Atti R. Accad. Gncei, 1930, [vi], 11, 774;A., 1387.82 K. S. Jackson and G. Rieniicker, J., 1930, 1687; A., 1107; J. A. N.Friend, ibicE., pp. 1633, 1903; A., 1107, 1246.23 D.L. Hammick, R. C. A. New, N. V. Sidgwick, and L. E. Sutton, ibid., p.1876; A,, 1239; H. Lindemann and L. Wiegrebe, Ber., 1930, 63, [B], 1660;A., 1171.A., 100704 BASSETT :formed. The chemical and physical properties of the tetrafluoridehave been examined.24The reaction COX + 2NH3 = CO(NH,), + H2S affords a moresuitable method for the manufacture of carbamide than the olderprocess using ammonia and carbon dioxide.25Carbonyl chloride is produced when carbon monoxide is passedover the heated chlorides of ruthenium, platinum, and gold, but notof rhodium, palladium, or osmium.26The hydrolysis of the cyanides of sulphur, selenium, tellurium,and phosphorus has been their molecular volumesmeasured,28 and the mobility of the OCN, SCN, SeCN, N(CN),,C(CN),, and N3 ions determined.29Vapour-pressure curves are taken to indicate the existence of fivedefinite silica hydrates.30 Very slow potentiometric titration of silicatesolutions has been tried as a means of studying the silicic acids,but without very definite results.31The attack of silica by hydrofluoric acid is not primarily dependentupon the concentration of the latter but upon that of the HF,' ion,and is directly proportional to it when the total ionic concentrationis high.31~Anhydrous titanium di- and tri-bromides have been prepared forthe first the latter by reduction of the tetrabromide at a redheat with hydrogen.On being heated at 400" in an atmosphere ofhydrogen, the tribromide breaks up in accordance with the equation2TiBr3 -+ TiBr, + TiBr,; the dibromide itself undergoes thereaction STiRr, --+ Ti + TiBr,, but only slowly a t 650".Boththe lower bromides react with hydrogen bromide to form thetetrabromide, and the reaction is rapid above 350". Titaniummetal reacts with hydrogen bromide above 300", and the lower thetemperature the more di- and tri-bromide are formed, which is similarto what was found for the reaction of hydrogen bromide with silicon.3324 0. Ruff and R. Keim, 2. anorg. Chem., 1930,192,249; A., 1387 ; P. Lebeauand A. Damiens, Compt. rend., 1930, 191, 939; A., 1931, 52.25 A. Klemenc, 2. anorg. Chem., 1930,191,246; A., 1387.26 W. Manchot and G. Lehmann, Ber., 1930,63, [B], 1221 ; A., 875.27 L. Birckenbach, K.Huttner, W. Stein, and I?. Ensslin, 2. anorg. Chem.,1930,190,l; A., 876.K. Huttner and S. Knappe, ibid., p. 27; A., 876.2s L. Birckenbach and K. Huttner, ibid., p. 38 ; A., 876.P. A. Thiessenand O.Koerner, 2.anorg. Chem., 1930,189,168,174 ; A., 720.31 W. D. Treadwell and W. Wieland, Helv. Chim. Actu, 1930, 13, 842; A . ,31a W. G. Palmer, J., 1930, 1666; A., 1133.32 R. C. Young and W. C. Schumb, J. Amer. Chem. SOC., 1930,52,4233; A , ,33 Idem, {bid., p. 1464; A., 720.1637.1931, 51INORGANIC CHEMISTRY. 65The existence of various zirconates has been demonstrated bymeans of fusion diagrams.34Pure zirconium and hafnium metals have been prepared bythermal decomposition of the iodides.35 The melting point anddensity of metallic hafnium are about 2500" Abs.and 13.31respectively .The precautions necessary to ensure the absence of impuritieswhen preparing pure hafnium salts have been described.36 Thesolubilities of the oxyfluorides and oxybromides of zirconium andhafnium in hydrofluoric and hydrobromic acid solutions have beendetermined.37The lowest hydrate of thorium nitrate is Th(N03)4,2H,0 butthoryl nitrate, ThO(NO,),,&H,O, can be obtained by desiccationof thorium nitrate in a current of air, carrying nitric acid vapour,above l l O O . 3 8Germanium monohydride, a dark brown powder, is formed by theaction of cold water on sodium germa~Gde.~~ Amorphous andcrystalline germanium monoxide and monosulphide have beendescribedtO as also several sulpho- and per-germanatestl andseveral phenyl germanium compounds.42 Germanium imide,germanam (Geg3H), and germanium nitride are formed whenammonia acts upon germanium tetrachloride.& R.Schwarz andH. Giese show that germanium tetrachloride forms no compoundwith hydrogen chloride corresponding to H,GeF,. In this respectgermanium is like silicon and unlike tin. They have also prepared12-molybdogermanic acid, H,[Ge(Mo,O,),], and the correspondingtungsten compound and their guanidinium salts.44 Several saltsof the 12-tungstogermanic acid have been described.44"84 H. von Wartenberg and H. Werth, 2. anorg. Chem., 1930, 190, 178 ; A.,85 J. H. de Boer and J. D. Fast, 2. anorg. Chem., 1930,187, 177, 193; A.,36 J. H. de Boer and J. Broos, ibid., p. 190; A., 438.37 G. von Hevesy and 0.H. Wagner, ibid., 191, 194; A., 1362.38 E. Chauvenet and Mme. Souteyrand-Franck, Bull. SOC. chim., 1930, [iv],39 L. M. Dennis and N. A. Skow, J . Amer. Chem. SOC., 1930, 52, 2369; A.,40 L. M. Dennis and R. E. Hdse, ibid., p. 3653; A., 1388; W. Pugh, J.,41 R. Schwarz and H. Giese, Ber., 1930,63, [BJ, 778 ; A., 720.42 C. A. Kraus and C. B. Wooster, J . Amer. Chem. Soc., 1930, 52, 372; A.,48 R. Schwarz and P. W. Schenk, Ber., 1930,63, [B], 296; A., 437.44 Ibid., p. 2428 ; A., 1637.44a A. Brukl, Monatsh., 1930,56, 179; A., 1638.847.437.47,1128; A., 1638.1007.1930,2369; A., 1637.364; C. A. Kraus and C. L. Brown, ibid., p. 4031; A., 1602.REP.-VOL. XXVII. 66 BASSETT :It is doubtful whether octammines of tin have been prepared.45Products supposed to be such were found to correspond to theformula [Sn,xNH3,yH,0]14, where x + y was approximately equalto 8.Lead perchlorate and its mono- and tri-hydrates have beenmade.The anhydrous salt is extremely soluble in water and isalso soluble in organic solvents.45a Crystalline and hydratedlead dioxides have been prepared, and the dehydration curves of thelatter examined.46 A dihydrate of lead oxalate is precipitated at0" and it is shown that lead oxalate (and manganous oxalate) areprobably complex.47Group V.Attempts to separate nitrogen into para- and ortho-forms similarto those of hydrogen have not been successfu1,48 although Smitsconsiders that he has evidence which indicates the complexity ofnitr~gen.~gFurther work has been published on the constituents of activenitrogen 5O and on the decay of its aftergl~w.~l The amount ofactive nitrogen present can be determined by shaking the gas withmercury at room temperature and estimating the ammonia formedby treatment of the product with 2.5% sodium hydroxide.Themost suitable phosphor for use with active nitrogen is boron nitrideactivated with carb0n.5~Some hydrazine is formed when a mixture of ammonia and nitrogenis passed over nickel gauze a t 340-355' or during the catalyticoxidation of ammonia by fine copper gauze at 340400' at lowpressures, the ammonia being in excess. It can also be obtainedby burning oxygen in ammonia.53 Reduction of nitric oxide byplatinised platinum in dilute hydrochloric acid produces smallamounts of hydroxylamine and ammonia.54 Nitrosyl perchlorate46 A. J. Cooper and W. Wardlaw, J., 1930, 1141 ; A., 874.OSa H. H. Willard and J. L. Kassner, J . Amer. Chem. Soc., 1930, 52, 2391 ;4 6 A. Simon, Z . anorg. Chem., 1930,185, 280, 300 ; A., 289, 308.4 7 R. Scholder and C . F. Linstrom, Ber., 1930,63, [B], 2831 ; A., 1931, 66.48 E. Justi, Naturwiss., 1930, 18, 227, 393; A . , 524, 721 ; P. Harteck andH. W. Schmidt, ibid., p. 282 ; A., 557.49 A. Smits and J. de Gruyter, Proc. K . Akad. Wetensch. Amsterdam, 1930,33, 86; Physikal. Z . , 1930, 31, 435; A . , 659; A. Smits, H. Gerding, and (Miss)W. Hertogh, Proc. K . Akad. Wetensch. Amsterdam, 1930,33,626 ; Physikal. z.,1930, 31, 768; A., 1096.Z. Bay and W. Steiner, Z .physikal. Chem., 1930, [B], 9, 93; A., 1087.A., 1007.s1 E. J. B. Willey, J . , 1930, 336, 1146; A., 624, 838.s2 E. Tiede and H. Chomse, Ber., 1930,63, [B], 1839; A., 1139.63 K. A. Hofmann and J. Korpiun, Ber., 1929,62, [B], 3000; A., 171.54 A. J. Butterworth and J. R. Partington, Tram. Farachy SOC., 1930, 26,144; A . 429INORGANIC CHEMISTRY. 67and nitrosylsulphuric acid are considered to be salts,s5 [NO]’[ClO,]’and [NO]’[HO*SO,]’. The additive compounds of phosphine and thetetrahalides of the elements of Group IV have been examined.56An investigation of the oxidation of phosphorus by oxygen andby air, both alone and in presence of moisture and of substancesinhibiting phosphorescence, has led to the conclusion that theoxidation has its seat in the gas phase and is autocatalysed byatomic oxygen.57The vapour pressures of phosphoric oxide under various conditionsof heating have been determined, and the results interpreted interms of the author’s theory of allotropy.58 Diammoniumamidopyrophosphate is formed by the action of gaseous ammoniaon phosphoric oxide.59The small amount of hexafluorophosphoric acid produced by theaction of phosphoric oxide on aqueous hydrofluoric acid can beisolated as the nitron salt.A large number of salts of the acid havebeen prepared and described. The nitron salts of hexafluoroar-senate and hexafluoroantimonate have been prepared by evaporationof potassium dihydrogen arsenate or potassium pyroantimonatewith hydrofluoric acid, followed by addition of ammonium andnitron acetates.60The variations in the colour of arsenious sulphide are purelyphysical in nature.61 L.W. McCay and W. Foster e2 showed thata very rapid current of hydrogen sulphide precipitates arsenicpentasulphide from solutions of arsenic acid after primary formationof monothioarsenic acid. This has been confirmed.63 Pyroarsenicacid itself and a number of pyroarsenates have been prepared.64Some further work on explosive antimony has been published,656 5 A. Hantzsch and K. Berger, 2. anorg. Chem., 1930, 190, 321 ; A., 1007.6 6 R. Holtje, ibid., p. 241 ; A., 876.67 J. Tausz and H. Gorlacher, ibid., p. 95; A., 876.58 A. Smits and H. W. Deinum, Proc. K . Akad. Wetensch. Amsterdam, 1930,69 A. Sanfourche, A. Hernette, and M.Fau, Bull. SOC. chim., 1930, [iv],6o W. Lange and E. Muller, Ber., 1930, 63, [ B ] , 1058; A., 877.61 H. B. Weiser, J . Physieal Chem., 1930, 34, 1021 ; A , , 721.33, 514, 619; 2. physikal. Chem., 1930,149, 337; A., 1096, 1372, 1251.47,273 ; A., 557.L. W. McCay, Amer. Chem. J . , 1888,10, 459; 2. anal. Chem., 1888, 27,632; A., 1889, ii, 15; L. W. McCay and W. Foster, Ber., 1904, 37, 573; A.,1904, ii, 253; W. Foster, J . Amer. Chem. SOC., 1916, 38, 62; A., 1916, ii,246.63 F. Foerster, G. Pressprich, and W. Reuss, 2. anorg. Chem., 1930, 188,90; A., 721.64 A. Rosenheim and H. Antelmann, ibid., 187,385 ; A., 558 ; A. Rosenheim,ibid., 193, 73; A., 1388.66 E. Cohen and C. C. Coffin, 2. physikd. Chem., 1930,149,417; A., 1268;H. von Steinwehr and A.Schulze, 2. Phyeilc, 1930,63,816 ; A., 126868 BASSETT :and a number of very complex chloroantimonates 66 and bromo-antimonites 67 are said to be formed by methods given.The preparation and analysis of K,V(CN), has been described.68Vapour-pressure measurements have been carried out with theprecipitated vanadic, niobic, and tantalic acids, but only with thefirst was there any indication of the existence of definite hydrates.69The isotherms and isobars of the system niobium-hydrogen aresimilar in form to those for vanadium and tantalum h y d r i d e ~ . ~ ~Borides of niobium and tantalum have been prepared,71 and thereaction of tantalum pentoxide with hydrogen chloride has beeninvestigated. 72It has been pointed out that element 91 (protoactinium) ischemically more like zirconium and thorium than like tantalum,and the carrier of this element in the residues from radium refiningis zirconium phosphate and not tantalum pentoxide.A dueappreciation of these facts facilitates the extraction of protoactinium,which occurs to the extent of about 0.6 mg. per g. of radium inuranium ores. Protoactinium (= ekatantalum) pentoxide is aheavy white powder, not acidic but definitely, though feebly, basic,soluble in fused sodium hydrogen sulphate, but not in fused sodiumcarbonate. 73croup V I .The mean normal boiling point of oxygen is - 182.97" & O-O10°.74The colour produced by the action of ozone on ammonia dependson the amount of water present and upon the temperat~re.~~Ozone decomposes sodium p e r b ~ r a t e .~ ~ A still for producingconductivity water has been described which is claimed to be cheap,strong, compact, durable, and easy to erect and to ~ o r k . ~ 7Experiments have been described which suggest that S, is a gel.In agreement with this, it is found that the Tyndall effect is to be66 L. I. Sauciuc, Bul. SOC. Chim. Romdnia, 1930,12, 36; A., 1388.6 8 A. Yakimach, Compt. rend., 1930,191, 789; A., 1031, 52.6Q G. F. Huttig and A. Konig, 2. anorg. Chem., 1930, 193, 81, 93, 100; A.,70 H. Hagen and A. Sieverts, ibid., 185, 225; A., 308.71 L. Andrieux, Compt. rend., 1929, 189, 1279; A., 178.72 V. Spitzin and L. Kaschtanov, J. Ruse. Phye. Chem. Soc., 1930,62, 295 ;73 A. von Grosse, 2. anorg. Chem., 1930, 186, 38; A,, 516; J .Amer.7* W. H. Keesom, (Miss) a. van der Horst, and (Miss) A. F. J. Jansen,75 W. Manchot, Ber., 1930, 63, (B], 1226; A., 877.78 F. Fichter and A. Goldach, Hdv. Chim. Actcc, 1930,13, 1200. '' J. M. Stuart and F. Wormwell, J., 1930, 86; A., 434.A. C. Vournazos, 2. anorg. Chem., 1030, 192, 369; A., 1388.1538.A,, 877.Chem. SOC., 1930, 52, 1742; A,, 883.Proc. K . Akad. Wetensch. Amsterdam, 1929, 32, 1167; A., 403INORGANIC CHEMISTRY. 69observed in pure molten sulphur.78 The cryoscopic behaviour ofa number of substances in molten sulphur has been inve~tigahd.'~Very pure sulphur hexafluoride has been prepared, and its vapourpressure measured between -72" and - 45". The b. p. (760 mm.) is- 63.8", and them. p. - 5043" & 0.2".80The best conditions for the preparation of pure hydrogen disul-phide have been described, and many of the physical constants ofthe compound determined;sl its parachor (130.0) shows that themolecule contains no double or co-ordinated valency linkage.Thef. p. curve of the system sulphur-hydrogen disulphide has no breakcorresponding with hydrogen trisulphide, so the latter compoundappears not to be a molecular compound of sulphur and hydrogendisulphide.The structure M,[SO,-SO] is proposed for the hyposulphites andis considered to agree with various decompositions and reactionswhich they undergo.82 The reactions between thiosulphate andsulphurous acid have been studied in detail, and upon them havebeen based good methods for preparing not only solid potassiumtrithionate but also solid sodium or ammonium tetrathi~nate.~~The PO,F ion of the fluorophosphates can replace the SO4 ionisomorphously and a number of fluorophosphates belonging to theferrous ammonium sulphate group and to the alums have beenprepared, as well as simple fluorophosphates.84Solid hexabromoselenous acid slowly loses bromine with formationof selenium monobromide.It will then give colloidal selenium ontreatment with water, but the pum acid dissolves in water withoutany such separation of selenium.85 The preparation of pure seleniumand tellurium tetrachlorides has been described, and many of theirphysical constants have been measured.86 The parachors of anumber of tellurium compounds now determined give a mean con-stant for tellurium of 79.4, which lies satisfactorily between theconstants for iodine and antimony.87The m.p. of tellurium purified by fractional distillation is 452.0"78 D. L. Hammick and M. Zvegintzov, J . , 1930,273 ; A., 419.79 C. R. Platzmann, Bull. Chem. SOC. Japan, 1929,4, 235; 1930,5, 79; A.,80 W. C. Schumb and E. L. Gamble, J . Amer. Chem. SOC., 1930, 52, 4302;81 K. H. Butler and 0. Maass, ibid., p. 2184; A., 1008.82 0. von Deines and G. Elstner, 2. anorg. Chem., 1930,191, 340; A., 1262.83 A. Kurtenacker and J. A. Ivanov, ibid., 185, 337; A., 302; A. Kurten-acker and K. Matejka, ibid., 193, 367; A., 1931, 52.s4 P. C. Rhy, Nature, 1930,126, 310; A., 1351.8 5 J. Meyer and V. Wurm, 2. anorg. Chem., 1930,190,90 ; A., 877.86 J.H. Simons, J . Amer. Che?n. Soo., 1930,52,3483,3488; A , , 1366.8' F. H. Burstall and S. Sugden, J., 1930, 229; A., 899.143, 568.A., 1931, 5270 BASSETT :(vac.) and is lowered in hydrogen and carbon dioxide by 0.15" and0.2 O respectively . *A method for preparing telluric acid directly from finely powderedtellurium by oxidation with chloric acid has been described.89Several mixed crystals of hexacarbamidochromic salts have beenprepared, such as those of permanganate and perchlorate, per-manganate and fluorob~rate,~~ and numerous complex chromiccompounds have been de~cribed,~~ of which a number of chromi-cyanides raise some interesting questions concerning the stabilityof polynuclear complexes which are important in connexion withother complex cyanides. A new type of red perchromate has beenprepared as the calcium salt Ca3Cr2012,12H20 by adding 30%hydrogen peroxide to a saturated calcium chromate solution atHydrazine in strongly acid boiling solution reduces sexavalentto quinquevalent molybdenum.In feebly acid solutions, complexescontaining both quinque- and sexa-valent molybdenum are pro-d ~ c e d . ~ , By the interaction of molybdenum pentachloride andvarious organic solvents, a number of substances have been obtainedwhich are formulated as derivatives of molybdenyl chloride, MoOCl,,and of molybdenum tetra~hloride.~~ Molybdenum-blue has a vari-able chemical composition. It is soluble in many organic solventsand, although it is a colloid, it is immediately extracted from itsaqueous solutions when they are shaken with certain organicMolybdic, tungstic (and vanadic) acids have beenstudied by the methods of potentiometric and conductometrictitration but, on the whole, the results are disappointing and notalways easy to interpret.95 X-Ray methods also have been appliedto the tungstic A large number of paratungstates and- 5O.92** A.Simek and B. Stehlik, J . Czech. Chem. Comm., 1930, 2, 304; A.,8 9 J. Meyer and W. Franke, 2. anorg. Chem., 1930,193, 191 ; A., 1389.90 E. Wilke-Dorfurt and R. Pfau, 2. Elektrochem., 1930, 36, 118; A., 722.9 1 R. Weinland and J. Lindner, 2. anorg. Chem., 1930,190, 285; A., 878;H. I. Schlesinger and (Miss) R. K. Worner, J . Amer. Chem. SOC., 1928,51, 3520; A., 178; H.I. Schlesinger and D. N. Rickles, ibid., p. 3523; A.,178; H. Reihlen and F. Kraut, Annalen, 1930, 478, 219; A., 686.92 J. A. Raynolds and J. H. Reedy, J . Amer. Chem. SOC., 1930,52,1861; A.,873.93 W. F. Jakbb and W. Kozlowski, Rocz. Chem., 1929,9, 667; A., 308.g4 W. Wardlaw and H. W. Webb, J . , 1930,2100; A., 1389.93a J. Duclaux and R. Titeica, Rev. gdn. Colloid., 1929,7, 289; A., 289.9 5 H. T. S . Brittonand W. L. German, J . , 1930, 1249, 2164; A., 860, 1371 ;H. T. S. Britton and R. A. Robinson, ibid., pp. 1261, 2328; A., 860, 1522;0. Jander and W. Heukeshoven, 2. anorg. Chem., 1930,187, 60; A., 438.986.e5a A. M. Morley, J., 1930, 1987; A., 1262INORGANIC CHEMISTRY. 71heteropolytungstates have been de~cribed.~~ With organic basesuranyl fluoride forms double salts of three different types, viz.,M(UO,)F,pH,O, M(UO,),F,,nH,O, and M(U0,),F7,nH,0.97Group VII.The b.p. of fluorine has been found to be 84.93' Abs., and itscritical temperature and pressure are about 144" Abs. and 55 atmos.Its vapour pressure has been measured over the range 72-86"A ~ S . ~ ~The solid compounds formed by the union of hydrogen fluoridewith perchloric acid and with boron fluoride are regarded asacidium salts by A. Hantzsch 99 and formulated as [FH,]'ClO,' and[FH,]'BF,', and several reactions of hydrogen fluoride and hydrogenchloride are interpreted in terms of the above [FH,]' ion and thecorresponding [ClH,]* ion. It has been shown that KF,3HF is adefinite compound, and a convenient apparatus for preparingfluorine by the electrolysis of this compound in the fluid conditiona t 100" has been described, with full details of procedure.1 Agood deal of work has been done on oxygen difluoride, the existenceof which is now well established.It is a colourless gas condensingto a yellow liquid, b. p. - 146.5', m. p. - 223-8', heat of formation- 4-6 & 2 kg.-cals.2 The m. p. of nitrogen trifluoride was deter-mined at the same time and found to be somewhat above - 216.6O.3According to H. von Wartenberg and G. Klinkott the heat of forma-tion of oxygen difluoride is - 11 kg.-cals.; these authors haveexamined the chemical reactions of the gas in some detail. Withpotassium iodide solution the reaction F20 + 4HI = 41 +2HF + H,O occurs, and this was made the basis of its estimation.Hydrobromic acid acts similarly, and so does hydrochloric acid, butvery slowly.With alkali the much slower reaction F,O + 2NaOH=2NaF + H,O + 0, occurs-no fluoroxy-acids being formed. Benzeneabsorbs the gas quantitatively, quinol and benzoquinonebeing formed. Reducing agents such as sodium thiosulphate,stannous chloride, ferrous sulphate, and arsenious oxide absorboxygen as well as the difluoride from mixtures containing both, butonly slowly. The oxygen difluoride is always prepared by P.A. Rosenheim, A. Wolff, J. E. Koch, and M. Siao, 2. anorg. Chem., 1930,193,47,64 ; A., 1389.9 7 F. Olsson, ibid., 187, 112; rl., 439.98 G. H. Cady and J. H. Hildebrand, J . Amer. Chem. Soc., 1930, 52, 3839 ;95 Ber., 1930, 63, [B], 1789; A , , 1140.A., 1508.1 2.anorg. Chem., 1930,193,409; A., 1931, 42.2 0. Ruff and W. Menzel, ibid., 190, 257 ; A., 877.3 0. Ruff and K. Clusius, ;bid., p. 267; A., 98672 BASSETT :Lebeau and A. Damiens's* method of passing fluorine in a finestream through weak sodium hydroxide solution. The oxidisingaction of fluorine on potassium hydrogen sulphate solution, on silver,stannous, ferrous, and cobaltous salts, and on titanic, vanadic, andmolybdic acids has been studied by F. Fichter and A. G~ldach.~By distribution experiments between nitrobenzene and waterand between benzene and water, it is shown that in both non-aqueoussolvents the concentration of hydrogen chloride is proportional toits partial pressure, indicating absence of ionisation.Since thedielectric constants of nitrobenzene and benzene are 34 and 2.2respectively, the ionisation of hydrochloric acid cannot be deter-mined by the dielectric constant of the solvent. The vapour-pressure data for aqueous hydrochloric acid solutions indicate thatonly hydrated molecules of the hydrogen chloride are ionised, andthat they exert a negligible partial pressure. It is the basiccharacter of the water, not its high dielectric constant, whichdetermines its capacity to cause ionisation.s The reactivities ofvarious oxides at different temperatures towards hydrogen chlorideand towards chlorine have been investigated.' The parachor ofchlorine dioxide has been determined, and several possible structuresof the molecule are considered.*A new chlorine fluoride, CIF,, has been prepared9 by heatingeither chlorine or its monofluoride with excess of fluorine.It is acolourless gas forming a pale green liquid, b. p. ll', and a whitesolid, m. p. - 83". It is chemically extremely active. A newfluoride of iodine, IF,, has also been obtained by heating a mixtureof iodine pentachloride and fluorine at 270-400'. It also is veryreactive chemically, and is colourless.1°The existence of bromine chloride has been confirmed by thenature of the products formed when mixtures of chlorine andbromine react with aliphatic diazo-compounds.ll According toH. Lux,la it is an ochre-yellow solid, m. p. - 54', which rapidlydecomposes in the vapour phase.According to 3'. A. Philbrick,13 the behaviour of iodine mono-4 Compt.rend., 1927, 185, 652; 1929, 188, 1263; A., 1927, 1044; 1929,Helv. Chim. Acta, 1930,13, 99, 378, 713, 1200; A,, 435, 722, 1140, 1537.13 W. F. K. Wynne-Jones, J . , 1930, 1064; A., 859.7 R. Wasmuht, 2. angew. Chem., 1930, 43, 98, 125; A., 439; V. Spitzin,779 ; Ann. Reports, 1929, 26, 63.2. anorg. Chem., 1930,189, 337 ; A., 874.G. H. Cheesman, J., 1930, 35 ; A., 278.a 0. Ruff and H. Krug, 2. unorg. Chem., 1930,190,270; A., 878.lo Idem, ibid., 193, 176 ; A , , 1390.T. W. J. Taylor and L. A. Forscey, J . , 1930, 2272; A,, 1565.l2 Ber., 1930, 63, [B], 1156; A., 878.l3 J., 1930, 2254; A., 1520INORGANIC CHEMISTRY. 73chloride in hydrochloric acid solution indicates that it is ionised toI' and Cl'.Small amounts of a volatile oxide of bromine, probably Br,O, areformed by the action of bromine on specially prepared, and veryreactive, mercuric oxide between 50" and 100°.14Potassium iodide can be partly converted into iodate by heatingin oxygen under pressure, and if the iodide is mixed with potassiumhydroxide the oxidation takes place still more readily, some periodatealso being formed.16The change of pink manganese sulphide into the orange and thegreen form occurs much more slowly if ammonium sulphide is usedfor precipitation instead of ammonium hydrogen sulphide and theaddition of ammonia before that of its sulphide hinders the changevery greatly.The green form is crystalline, but the other two areamorphous. 16Two series of complex manganifluorides have been obtained, vix.,MMnF,,nH,O and M.JHnF6, where M is an organic base.Theformer represents a new type, whilst the latter corresponds to thealkali manganif€uorides.l7Manganese dioxide may be prepared from any lower oxide bydirect oxidation with oxygen; by using sodium hydroxide ascatalyst at 400-500", a product containing 5 6 9 5 % MnO, may beobtained.18 K,Mn(CN), may be prepared by the addition of asaturated solution of potassium permanganate to an 80% solutionof potassium cyanide until red acicular crystals are produced.l9Some new perchlorates and permanganates have been described,as well as a number of fluorosulphonates which are isomorphouswith them.20One hears no more of masurium nowadays, but rhenium isthoroughly well established among the elements.Very purepotassium per-rhenate can, in fact, now be obtained commerciallyfrom the " Vereinigten Fabriken zu Leopoldshall." Its technicalpreparation has been described by W. Peit.21The formation of per-rhenate occurs so extremely easily that thel4 E. Zintl and G. Rieniicker, Ber., 1930,83, [B], 1098; A., 878.15 F. A. Henglein and L. Teichmann, 2. anorg. Chem., 1930,188, 138 ; A.,lo G. Landesen and M. Reistal, ibid., 193, 277 ; A., 1639.l7 F. Olsson, ibid., 187,313; A., 688.722.Y . Kato and T . Matsuhashi, J . 8oc. Chem. Ind. Japan, 1929,32, 313 B,316 B ; A., 1930, 308.19 A. Yakimach, Compt. rend., 1930, 190, 681; A., 658.20 E. Wilke-Dorfurt, G. Balz, and A. Weinhardt, 2. anorg. Chem., 1930,21 2.angew. Chem., 1930,43,469; B., 822.185,417 ; A., 308.c 74 BASSETT :preparation of compounds of the lower oxidation stages is verydifficult. It has been shown that zinc and hydrochloric acidreduce per-rhenate through the various intermediate stages to metal,with the possibility of halting a t these stages. Sodium amalgamand hydrazine both reduce i t to metal, but in each case someadmixture of lower oxides is present.22 The electrical conductivityof potassium per-rhenate for concentrations between 0.04 and 0.0005g.-mol. per litre has been determined a t 18", 25", 30", and 40".23From weakly acid solutions soluble per-rhenates can be precipitatedand estimated quantitatively by means of " nitron." 24Group V I I I .The conditions under which iron reacts with carbon monoxide toform oxide, carbide, or graphite have been examined,25 as havethose necessary for the oxidation of ferrous hydroxide to ferrousferrite rather than to ferric hydroxide.26 Different forms of ferrichydroxide, y- and tc-, result according as ferrous ferrite is or is not anintermediate stage.27 The results of recent work leave it doubtfulwhat hydrates of ferric oxide actually exist.28 The action of iron a thigh temperatures on hydrogen sulphide, hydrogen selenide, andcarbon disulphide has been examined,29 and a full investigation hasbeen made of the reaction FeS, zz FeS + S.30 It has beenshown that carbonyl groups in iron pentacarbonyl can be replacedby various amines, and a number of the compounds so obtained aredescribed.31 Several compounds of metal carbonyls with ironhalides have been prepared, and the space occupied by carbonmonoxide in various complex metal compounds has beenestimated.32 Iron tetracarbonyl, prepared by the action of alkalialkoxide on iron pentacarbonyl, has been shown to be [Fe(CO),],.Details of many of its reactions and derivatives are given.33zp F.Krauss and H. Steinfeld, 2. anorg. Chem., 1930,193, 385; A., 1931,63.23 N. A. Puschin and P. S. Tutundiib, ibid., p. 420; A., 1931, 43.24 W. Geilmann and A. Voigt, ibid., p. 311 ; A., 1547.2 5 V. Hofmann and E. Groll, ibid., 191, 414; A., 1263.z 6 C. Sandonnini, Gazzetta, 1930, 60, 321 ; A . , 878.2 7 G. Schikorr, 2. anorg. Chem., 1930, 191, 322; A., 1263.z * P.A. Thiessen and R. Koppen, 2. anorg. Chem., 1930,189, 113; A., 559;V. Rodt, Rec. trav. chim., 1930,49,441; A., 723 ; G. F. Huttig and A. Ziirner,2. EZektroch>em., 1930, 36, 259 ; A . , 723.*' J. B. Peel, P. L. Robinson, and C. L. Mavin, Proc. Univ. Durham Phil.Soc., 1929, 8, 153 ; A., 179.30 F. de Rudder, BUZZ. Xoc. chim., 1930, [iv], 47, 1225.31 W. Hieber, Naturwiss., 1930,18, 33 ; A., 309 ; W. Hieber, F. Sonnenkalb,32 W. Hieber, K. Ries, and G. Bader, 2. anorg. Chem., 1930,190, 193, 215;33 W. Hieber and E. Becker, Ber., 1930,63, [B], 1405; A., 1008.and E. Becker, Ber., 1930,63, [ B ] , 973 ; A., 723.A . , 875INORGANIC CHEMISTRY. 75It is said that the compound supposed by W. Manchot andto be Fe(N0),2MeOH is, in reality, a derivative of bivalent H.GallCH 0 .,,,NO .,... OH iron, with the structure c~~o>Fe~.~~No~,,.Fe<OCH3. By theaction of nitric oxide on nickel carbonyl, a somewhat similar com-pound, Ni(NO)(OCH,)OH + CH30H, was obtained.35R. Brunner has described the preparation of several compoundsfrom sodium nitroprusside,36 and numerous compounds of hem-methylenetetramine with ferro- and ferri-cyanides have beenobtained .37A phase-rule study of the cobalt chloride colour change has beenmade, and the red salt [Co(H,O),]HgCl, and the blue salt[Mg((H20)2},]CoCl, were isolated as well as several series of redsolid solutions containing zinc chloride. Neither the simple dehydra-tion theory nor the " variable co-ordination " theory of the colourchanges is supported by the data.It is considered to be largelyaccidental that red cobalt chloride solutions contain red kations andblue solutions blue anions. In a more general way, the colour of cobalt -ous compounds is determined by the character of the electronicshift which is possible in the cobalt atom of the compound inquestion.38 The electro-deposition of cobalt from red and fromblue solutions has been examined, and found to be reversible onlyfrom the latter.39The dehydration curves of hydrated cobaltous oxide prepared indifferent ways have been determined, as well as the catalyticactivity of the metal reduced from various types of oxide.*O Themolybdates of various cobaltic ammines have been prepared.4lVapour pressures of nickel carbonyl have been measured over thetemperature range -35" to 40°.42 Nickel thiosulphate forms ahexammine, a tetrammine, and a diammine, but not the pentamminedescribed by Ephraim.& The dehydration curves and X-raydiagrams of hydrated nickelous and nickelic oxides have beenexamined.44 The latter forms a monohydrate which breaks upirreversibly thus, 2(Ni,03,H20) -+ 4Ni0 + 2H20 + 0,.Accord-34 Ann. Reports, 1929, 26, 66.36 H. Reihlen, A. Gruhl, G. von Hessling, and 0. Pfrengle, Annnlen, 1930,36 2. anorg. Chem., 1930,190,384; A., 1009.37 G. A. Barbieri, Gazzetta, 1930, 60, 229 ; A., 752.38 H. Bassett and H. H. Croucher, J., 1930, 1784 ; A., 1251.39 R. Brdizka, J . Czech. Chem. Comm., 1930,2,489; A . , 1254.40 G. F. Huttig and R. Kassler, 2. anorg. Chem., 1930,187, 16,24; A., 543.41 P.R. RBy and S. N. Maulik, J . Indian Chem. SOC., 1930,7,607 ; A., 1390.42 J. S. Anderson, J., 1930, 1653: A., 1104.43 L. le Boucher, Anal. Pk. Quim., 1930,28,895; A., 1391. '* G. F. Huttig and A. Peter, 2. artorg. Chem., 1930,180, 183, 190; A., 700.482,161 ; A., 153976 BASSETT :ing to D. K. Goralevitsch,46 colourless alkaline-earth salts ofnickelic acid, H2Ni04, can be obtained by fusion of nickel oxide withpotassium nitrate or chlorate and potassium hydroxide, followedby extraction with water and addition of the appropriate reagentto the green solution. BaNiO,, NO4, and Ni,O, are also said to havebeen 0btained.4~"as well as somealkali-metal bromides of rhodium 47 and some rhodium pyridinebromides.48 The ruthenium analogue of potassium nitroprusside,K2[ Ru( CN) ,NO J,2H20 (also anhydrous), has been prepared byW.Manchot and J. Diising;48a and by the action of carbon monox-ide on ruthenium tribromide the compound RuBr( CO) containingunivalent ruthenium has been obtained.49The remarkable case of lithium platinocyanide, the trihydrate ofwhich was supposed to become unstable with reference to thedihydrate at lower temperaturesY50 has been shown to have anentirely different e~planation.~lBy the action of sodium amalgam on solutions of potassium (orbarium) platinocyanide or potassium palladocyanide, colourless,strongly reducing solutions are obtained which contain univalentplatinum or palladium. 62The thermal decomposition of platinous and platinic sulphideshas been studied, but no indication of any other sulphide was ob-tained.63 Platinum diarsenide identical with the mineral sperrylitehas been prepared.64The brownish-yellow double salt PtC12,2NH,,4(PtC~,4NH,)can form solid solutions in PtC12,4NH,,nH20, and this is the cause ofthe yellowish-brown colour which the latter compound has whenprepared by the action of ammonia on K2PtC1,.65Numerous nitro-ammines of platinum have been described .5645 J .Russ. Phys. Chem. SOC., 1930, 62, 897; A . , 1141.46a Idem, ibid., p. 1166; A., 1540.46 A. W. Mond, J . , 1930,1247; A., 891.4 7 P. Poulenc, Compt. rend., 1930, 190, 639; A . , 559.4 8 Idem, ibid., 191, 64; A., 1391. 48a Ber., 1930, 63, [ B ] , 1226.4@ W. Manchot and E. Enk, ibid., p.1635; A . , 1141.61 H. Terrey, ibid., 1930, [ A ] , 128,359; A., 1141.6a W. Manchot and G. Lehmann, Ber., 1930, 63, [ B ] , 2776; A., 1931, 53;53 W. Biltz and R. Juza, 2. anorg. Chem., 1930,190,161 ; A., 861.64 L. Wohler, ibid., 186, 324; A., 440.6 5 N. S. Kurnakov and I. A. Andrhvski, 2. anorg. Chem., 1930,189, 137;A., 560; Ann. Inst. Platine, 1929, 7, 161; A., 1930, 180.66 I. I. Tschernaiev, ibid., 1929, 7, 52; A., 179; I. I. Tschernaiev andA. N. Fedorova, ibid., p. 73 ; A., 180; I. I. Tschernaiev and F. M. Klatschkin,ibid., p. 84; A., 180.The acetates of ruthenium have beenJ. E. Reynolds, PTOC. Roy. SOC., 1909, [ A ] , 82, 380; A., 1909, i, 659.W. Manchot and H. Schmid, ibid., p. 2782; A., 1931, 53INORGANIC CHEMISTRY. 77A large number of platinum tetrammine salts have been preparedand examined, and from the character of their electrical conductivityand absorption spectra it is concluded that they possess six co-ordinatively bound groups, and not four as hitherto assumed.57They should be formulated as [Pt(NH,),X,], although in solventssuch as water, alcohol, or acetone they are readily converted intostable salts of the type [Pt(NH3)4(solvent)2] X,.The ammine amides of 4-valent platinum, such as[Pt(NH,),* (NH,)*CllC~,,have been investigated with respect to their behaviour towardsacids and bases.58 Of the ammonia compounds examined, the3-amido-diammine was the most basic.The behaviour of allthe compounds is adequately represented by the equation[R - Pt . . . NH3In+l +- [R - Pt - NH,]"+ H .Someinteresting stereochemical questions are raised in two papers onplatinum compounds by F. G. Angell, H. D. K. Drew, andW. ward la^,^^ and by F. G. Mann 6o respectively. These are dealtwith in another section of the present volume (pp. 164, 166).Systems and Equilibria.Platinum-iron ;61 platiniim-iridium ;62 rhodium-bismuth ;63palladium-antimony gold-antimony ; 65 iron-beryllium andiron-boron ;ss iron-manganese ;67 nickel-copper ;68 silver-copper ;69cuprous iodide-silver iodide ; 70 potassium selenate-water ; 7 1 copper-oxygen ; 72 titanium-hydrogen ;73 nitrogen pentoxide-nitric acid ;74zirconium dioxide-beryllium oxide ; 75 tellurium dioxidehydrogen676869606 1626364656%67A. Hantzsch and F.Rosenblatt, 2. anorg. Chem., 1930,187,241 ; A., 440.A. A. Griinberg and G. P. Faormann, ibid., 193, 193; A., 1540.J., 1930, 349 ; A., 559.Ibid., p. 1746; A., 1404.V. A. Nemilov, Ann. Inst. PZatine, 1929,7, 1 ; A., 147.Idem, ibid., p. 14; A., 148.E. J. Rode, ibid., p. 21; A., 148.A. T. Grigoriev, ibid., p. 32; A., 148.Idem, ibid., p. 45; A., 148.F. Wever, 2. tech. Physik, 1929, 10, 137; A., 148.W. Schmidt, Arch. Eikenhiittenw., 1929-1930, 3, 293 ; Stahl iind Eisen,1929, 49, 1696; A., 148.1929, 32, 912, 921; A., 148.68 A. Krupkowski and W. J. de Haas, PTOC. K. Akad. Wetensch. Amsterdam,139 0. Weinbaum, 2. Metallb., 1929,21,397; A., 149.?* G. Lunde and P. Rosbaud, 2. physikal. Chem., 1929, [B], 6,115; A., 149.7 1 J. A. N. Friend, J., 1929, 2782; A,, 149.73 L.Kirschfeld and A. Sieverts, 2. physikal. Chem., 1929,145,227 ; A., 161.74 E. Berl and H. H. Saenger, Monatsh., 1929,53 and 54,1036; A., 161.76 0. RUB, F. Ebert, and E. Stephan, 2. anwg. Chern., 1929,185, 221; A , ,R. Vogel and W. Pocher, 2. Metallk., 1929,21, 333, 368; A., 161.16278 BASSETT :fluoride-water ;76 nickel-bismuth ;77 lead-germanium ;78 silver-copper-zinc ;79 copper-tin-antimony ;SO potassium chloratesodiumchlorate ;sl calcium chloride-cobalt (or iron, manganese, or cadmium)chloride ;81a metal halides-hydrogen ; metal halides-hydrogenchloride ;82 magnesium sulphate-sodium sulphate-watermagnesium sulphate-sodium nitrate-water ammonium nitrate-potassium sulphate-water ;85 alumina-cryolite-chiolite aceticacid-acetate of potassium (or NH,, Li, Pb, Ba, Ca, Zn);s7 iron-nitrogen nickel-chromium ;8g water-ether-uranyl nitrate orzinc iodide or cadmium iodide silver-aluminium-zinc ;91 sodiumiodate-sodium sulphate-water ;92 sodium chloride-magnesiumsulphate-water ;93 nickel-chromium ;94 ferrous sulphate-water ;95calcium-calcium nitride ; 96 iron-carbon-oxygen ; 97 sodiumhydroxide-sodium nitrate-water ;98 copper sulphate-sulphuricacid-water ;99 zinc oxide-zinc chloride-water ;l potassium sulphate7 6 E.13. R. Prideauxand J. O’N. Millott, J., 1929, 2703; A., 163.7 7 G. Hagg and G. Funke, 2. physikal. Chem., 1930, [B], 6, 272; A., 284.T. R. Briggs and W. S. Benedict, J.*PhysicaZ Chem., 1930, 34, 173; A.,284.79 S. Ueno, Mem. Coll. Sci. Kyoto, 1929, 12, 347; A., 284.So M.Tasaki, ibid., p. 227; A., 285.81 A. P. Vitoria, Anal. Pis. Quim., 1929, 27, 787; A., 293.81a A. Ferrari and A. Inganni, Atti R. Accad. Lincei, 1929, [vi], 10, 253;S 2 K. Jellinek and R. Koop, 2. physikal. Chem., 1929, 145, 305; A . , 294.8 3 W. Schroder, 2. angew. Chem., 1929, 42, 1076; A., 294.84 Idem, 2. anorg. Chem., 1930, 185, 267; A., 294.8 5 E. Janecke, 2. angew. Chem., 1929,42, 1169; A., 294.L. Wasilewski and S. Mantel, Przemysi Chem., 1930,14, 25 ; A., 299.8 7 A. W. Davidson and W. H. McAllister, J . Amer. Chem. SOC., 1930, 52,8 8 S. Epstein, H. C. Cross, E. C. Groesbeck, and I. J. Wymore, U.S. Bur.89 S. Nishigori and M. Hamasumi, Sci. Rep. TGhoku Imp. Univ., 1929, 18,90 (Mlle.) 0. Guempel, Bull. Soc. chim. Belg., 1929, 38, 443; A., 420.91 S.Ueno, Mem. Coll. Sci. Kyoto, 1930, [A], 13, 91 ; A., 536.92 H. W. Footeand J. E. Vance, Amer. J . Sci., 1930, [v], 19, 203; A.,93 V. P. Iljinski and A. F. Sagaidatschni, J . Russ. Phys. Chem. SOC., 1929,g4 Y. Matsunaga, J . Study Met. Japan, 1929,6, 207 ; A., 680.95 F. K. Cameron, J. Physical Chem., 1930, 34, 692; A., 683.B6 A. von Antropoff and E. Falk, 2. anorg. Chem., 1930,187, 406; A., 699.s7 E. Scheil and E. H. Schulz, ibid., 188, 290; A,, 701.98 E. JLinecke, ibid., p. 72; A., 701.09 H. D. Crockford and L. E. Warwick, J. Physical Chem., 1930, 34, 1064;A., 285.507; A., 406.Stand. J . Res., 1929, 3, 1005; A., 419.491 ; A., 419.544.61, 1953; A., 544.A., 701.1 H. C. Holland, J., 1930,643; A., 701INORGATSIC CHEMISTRY.79magnesium sulphate-water ;2 water-alkali sulphate-sulphate ofvitriol type ;3 magnesium sulphate-potassium nitrate-water ;magnesium chloride-sodium nitrate-water ; sodium dichromate-ammonium chloride-water ;6 potassium sulphate (or sulphuric acid)-hexamminocobaltic sulphate-water ;' sodium palmitate-water-sodium chloride ; sodium germanate-sodium silicate and potassiumgermanate-germania ; lead-antimony-magnesium ; 13 potassiumand calcium carbonates and hydroxides-water ;lo iron-manganese ;I1iron-silicon ;I2 iron-nitrogen ;13 sodium sulphate-sodium carbonate-water ;la sodium chloride-magnesium sulphate-water ;15 aluminiumsilicon-copper ;I6 sodium (or potassium) bromide (or iodide)-water ;17phenol-silver nitrate-water ;18 iron-nitrogen ;19 sodium oxide-silica ;20 sodium oxide-boric oxide-water ;21 sodium oxide-silica-zirconium dioxide ;22 calcium chlorate-potassium chloride-water ;23B.A. Starrs and L. Clarke, J. Physical Chem., 1930, 34, 1058; A., 702;A. Benrath and L. Cremers, 2. anorg. Chem., 1930,189, 82; A., 702.A. Benrath, H. Benrath, and H. Wazelle, &id., p. 72; A., 702.A. Sieverts and H. Mdler, ibid., p. 241 ; A., 702.I. Gerasimov, ibid., 187, 321 ; A., 702.P. B. Sarkar and T. P. Barat, J . Indian Chem. SOC., 1930, 7, 119, 199;J. W. McBain, L. H. Lazarus, and A. V. Pitter, 2. physikal. Chem., 1930,B. A. Starrs and H. H. Storch, ibid., p. 2367; A., 1523.A., 702, 1009.147, 87 ; A., 702.8a R. Schwarz and M. Lewinsohn, Ber., 1930,63, [B], 783 ; A., 721.E.Abel, 0. Redlich, and F. Spausta, 2. anorg. Chem., 1930,190, 79; A.,861.lo M. 1. Ussanovitsch and S. A. Borovik, Ukraine Chem. J., 1929, 4, 479;A., 861.l1 A. Osawa, Sci. Rep. TGhoku Imp. Univ., 1930, 19, 247; A., 987; E.ohman, 2. physikaZ. Chem., 1930, [B], 8, 81 ; A., 988.l2 B. Stoughton and E. S. Greiner, Amer. Inst. Met. Eng. Tech. Pub., 1930,No. 309, p. 3 ; A., 988 ; J. L. Haughton and M. L. Backer, J . Iron Steel Inst.,1930,121, 315 ; A., 1931, 32.l3 0. Eisenhut and E. Kaupp, 2. Elektrochem., 1930,36, 392; A., 996.1 4 N. S. Kurnakov and S. Z . Makarov, Ann. Inst. Anal. Phys. Chem., 1930,1 5 N. S. Kurnakov and M. A. Opichtina, ibid., p. 365; A., 997.16 G. G. Urasov, S. A. Pogodin, and G. M. Samorueev, Min. Ssyrje Zwet.1 7 A.F. Scott and E. J. Durham, J . Physical Chem., 1930, 34, 1424; A.,4, 307; A., 997.Met., 1929,4, 160; Chem. Zentr., 1930, i, 1038; A., 1106.1107.C. R. Bailey, J., 1930, 1534; A., 1120.10 E. Lehrer, 2. Elektrochem., 1930,36, 460 ; A., 1121.20 F. C. Kracek, J. Physical Chem., 1930,34, 1683; A., 1121.21 U. Sborgi and L. Amelotti, Gazzetta, 1930, 60, 468; A., 1122.22 J. D'Ans and J. Loffler, 2. anorg. Chem., 1930,191, 1 ; A., 1122.23 Y. Osaka and H. Nishio, Bull. Chem. SOC. Japan, 1930, 5, 181; A.,112280 BASSETT :iron-nickel-sulphur ;24 nickel-chromium ;25 Ca + 2NaC1 Z 2Na + CaCl, ;26 carbamide-ammonium nitrate-sodium nitrate ;27ammonium carbamate-carbamide-water-ammonia ;28 boric oxide-caesium oxide-water ;29 lithium-silver ;30 cadmium-zinc ;31 lead-antimony ;32 lead-tin ;33 manganese oxide-cadmium oxide ;=manganese oxide-magnesium oxide ;35 alumina-chromium sesqui-oxide ;35 alumina-ferric oxide ;35 chromium sesquioxide-ferricoxide ;35 iron-boron ;36 ammonium nitrate-water ;37 carbon dioxide-ammonia-water ;38 alumina-sodium (or potassium) oxid+water ;39cadmium sulphate-potassium (or ammonium) sulphate-water ;40potassium oxide-lime-silica ;41 Fe + NiSiO, rt Ni + PeSiO, ;42silver-strontium and silver-barium water-hydrogen fluoride ;44K2C03 + 2NaHC0, =+ Na,CO, + 2KHC0, ;45 potassium carbonate,bicarbonate, and water ;46 sodium sulphate, fluoride, and chloride andwater ;47 mercuric oxide-sulphur trioxide-water ;48 copper sulphate-24 R. Vogel and W. Tom, Arch. Eisenhuttenw., 1929-30, 3, 769; Staid und25 S. Sekito and Y. Matsunaga, J . Study Met. Japan, 1929,6,229; A., 1245.2 6 E. Rinck, Compt. rend., 1930,191, 404; A., 1252.27 W. J. Howells, J., 1930, 2010; A., 1252.28 H. J. Krase and V. L. Gaddy, J . Amer. Chem. SOC., 1930, 52, 3088; A.,29 A. P. Rollet and L. Andrits, Compt. rend., 1930,191,376; A., 1261.30 S. Pastorello, Bazzetta, 1930, 60, 493 ; A., 1359.31 D. Stockdale, Inst. Metals, Sept. 1930, Advance Copy; A., 1359.32 D. Solomon and W. M. Jones, Phil. Mag., 1930, [vii], 10, 470; A.,33 K. Honda and H. AbB, Sci. Rep. Tdhoku Imp. Univ., 1930,19, 315; A.,34 L. Passerini, Bazzetta, 1930,60, 535; A., 1361.35 Idem, ibid., 644; A., 1361.36 F. Wever and A. Muller, 2. anorg. Chem., 1930,192,317; A., 1372.37 E. Jhnecke and E. Rahlfs, ibid., p. 237; A., 1373.3 8 Idem, 2. Elektrochem., 1930,36, 645; A., 1373.39 R. Fricke and P. Jucaitis, 2. anorg. Chem., 1930,191, 129; A., 1374.40 K. L. Malhotra and H. D. Suri, J. Physical Chem., 1930, 34, 2103; A.,4 1 G. W. Morey, F. C. Kracek, and N. L. Bowen, J . SOC. Glass Tech., 1930,42 H. zur Strassen, 2. anorg. Chem., 1930,191, 209; A., 1375.43 F. Weibke, ibid., 193, 297; A., 1509.44 G. H. Cady and J. H. Hildebrand, J . Amer. Chem. SOC., 1930,52,3843 ; A.,45 A. E. Hill, ibid., p. 3813; A . , 1523.46 Idem, ibid., p. 3817; A., 1523.4 7 H. W. Foote and J. F. Schairer, J . Amer. Chem. SOC., 1930, 52, 4202,48 M. PaiE. Bull. SQC. chim., 1930, 47, 1254; Compt. rend., 1930,190, 1014;Eisen, 1930, 50, 1090; B., 910.1252.1359.1359.1374.14, 149; A., 1374.1521.4210; A., 1931,41.A , . 701INORQANIC OHEMISTRY. 81lithium sulphate-water ;49water (and related systems)Group I.s1sodium chloride-magnesium sulphate-silver iodide-metal chlorides ofH. BASSETT.H. D. Crockford and M. M. Webster, J . Phys~cccl Chem., 1930, 34, 2375;A., 1523.50 N. K. Voskressensks, J . Apppl. Chem. Rueeia, 1930,3,321; A., 1523.61 V. P. Radischtschev, J. Rues. Phys. Chem. SOC., 1930,62,1063 j A., 1623

ISSN:0365-6217    

DOI:10.1039/AR9302700052

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART I ,-ALIPHATIC DIVISION.Pyrolysis of Hydrocarbons.STUDY of the action of heat on paraffin hydrocarbons has demon-strated that two types of reaction occur, degradative and additive.I n the thermal decomposition of the normal paraffins rupture of thechain appears to occur a t any position with production of an olefinand the complementary lower paraffin or, a t the limit, hydrogen.Methane represents a special case, possessing a higher decompositionpoint than its homologues. With this hydrocarbon little decom-position occurs below lOOO", a t which temperature both ethyleneand acetylene are formed; a t higher temperatures under atmos-pheric pressure decomposition into carbon and hydrogen is prac-tically complete. For the maximum production of ethylene andacetylene, reduced pressure is essential and a t 1200"/100 mm., withsuitable rates of flow, 4% of ethylene and 2.5% of acetylene areformed ; above this temperature the quantity of ethylene diminishesto zero while the amount of acetylene increases (14.5y0 a t 1500"/50mm.).With isobutane, fission a t CH linkings to yield hydrogenand isobutylene becomes a major reaction.The formation of ethylene and acetylene from methane affords asimple instance of the additive reactivity which is concerned in theaddition of olefin to olefin. To the interaction of the olefins whichare produced a t an early stage of the thermal decomposition of theparaffins, the formation of aromatic hydrocarbons is attributed.Consequently the behaviour of the olefins under the action of heatis a matter of considerable practical importance.Examination of the thermal decomposition of ethylene, propylene,and the two n-butylenes3 suggests that the principal primaryreactions in each instance are the formation of either two-carbonor four-carbon olefins (or of both) : 2C,H4 --+ C4H,; 2C,H, -+1 For a review of the extensive literature dealing with the decompositionof paraffin hydrocarbons by thermal means, with and without catalysts, byelectrical means, by photosensitisation, and by a-particles, see G.Egloff ,R. E. Schaad, and C. D. Lowry, jun., J. Physical Chem., 1930,34, 1617; A.,1268.2 E. N. Hague and R. V. Wheeler, J., 1929, 378; A., 1929, 536; F. deRudder and H. Biedermann, Bull. SOC.chim., 1930, [iv], 4'4, 704; A., 1268;C. D. Hurd and L. U. Spence, J. Amer. Chem. SOC., 1929,51, 3353, 3561 ; A.,1930, 58, 191.R. V. Wheeler and W. L. Wood, J , , 1930, 1810; A . , 1309ORGANIC CHEMISTRY .-PART I. 83C,H4 + C4H8 ; C,H, --+ 2C,H4. Thus polymerisation and degrad-ation occur side by side, but the primary processes are speedilyfollowed by dehydrogenation (a primary mode of decomposition inthe case of butylene). In the presence of the hydrogen so liberated,the olefins decompose through the scission of the carbon chain at thelast C - C linking, forming radicals which by hydrogenation producemethane and the next lower olefin : CH,*CH:CH, --+ CHI,* +*CH:CH, ?!$ CH, + CH2:CH, ; CH,*CH,*CH:CH, -+ CH3* +*CH,*CH:CH, ?$ CH, + CH,-CH:CH,.Butadiene, formed bydehydrogenation of butylene, is thought always to be present in theearly stages of decomposition and it is suggested that the combin-ation of ethylene and butylene, of propylene and butadiene, and ofbutylene and butadiene yields hydroaromatic hydrocarbons whichat higher temperatures lose hydrogen to yield benzene and itshomologues .The degradation of the paraffins can be viewed as proceeding bythe reversible elimination of a molecule HX, which may be either aparaffin of smaller molecular weight or hydrogen itself. The residueis then an olefin, and the process is comparable with the eliminationof acid and water from any olefin addition p r o d ~ c t . ~The additive process can probably proceed in two ways, whichare cha.racteristic of olefin polymerisation and butadiene-olefinaddition respectively.Both of these processes are discussed later(pp. 91,88) and need no further mention here, but it would seem fromrecent developments in these directions that of the two mechanismswhich have been suggested for the production of hydroaromaticcompounds, vix. (1) direct butadiene-olefin addition and (2) theintermediate formation of (open-chain) hexadienes or hexatrienesby addition of olefin to olefin, the former is the more probable.Carbon Unsaturation.Mono-ole$nic and Mono-acetylenic Compounds.-Inability toobtain homogeneous specimens or to determine the composition ofmixtures of isomerides is frequently a great disadvantage of thecommon methods of olefin preparation.For this reason the dis-covery of a general method for obtaining pure Aa-olefins by theaction of zinc on p-alkyloxy-n-alkyl bromides, and the elaborationof a method for estimating the proportion of admixed Aa- andA@-butenes by determining the rate of reaction of their dibromideswith potassium iodide, are of importance.T. M. Lowry, J . , 1929, 378; A., 1929, 536.H. B. Dykstra, J. F. Lewis, and C. E. Boord, J . Arner. Chem. SOC., 1930,R. T. Dillon, W. G. Young, and H. J. Lucas, ibid., p. 1953; A., 888 ;52,3396; A., 1269.W. G. Young and H. J. Lucas, ibid., p. 1964; A., 88884 FARMER :Announcements have been made with regard to the occurrenceof an unexpected variety of isomerism in AB-pentene.7 Thehydrocarbon as prepared by dehydrobromination of y-bromopentane,or dehydration of diethylcarbinol, is reported to pass under theinfluence of ultra-violet light into an isomeride.This differs fromthe fht compound only slightly in physical properties but verymarkedly with regard to the proportion of p- and y-bromopentaneproduced therefrom by the action of hydrogen bromide. Toexplain the relationship of the isomerides, the absorption spectraof which differ sufficiently markedly to exclude their representationas cis- and trans-isomerides, a species of electronic isomerismdependent on unequal sharing of electrons at the double linking ispostulated.The observation that cis-forms of ethylene compounds suffercatalytic reduction more readily and smoothly than the trans-varieties has been found to apply to isocrotonic acid, to isostilbene,and to cis-o-hydroxy- and cis-o-ethoxy-cinnamic acids, all of whichare more readily reduced to saturated acids than are the correspond-ing trans-compounds.* On applying the method to confirm theconfigurations of erucic and brassidic acid, it is found that thedifference in their rate of hydrogenation (to behenic acid) is lessmarked than in the case of oleic and elaidic acids, but is sufficient toestablish them as the cis- and trans-forms of the acidCH,*[CH,] ,*CH:CH*[ CH,], ,*CO,H.In spite of contradictory results obtained by other methods itappears from the study of eleven triple-bonded substances ofdifferent types that hydrogenation of acetylenes in the presence ofcolloidal palladium stabilised by starch uniformly gives the cis-ethylenic derivative .gThe very different courses followed by hydrogenation processeshave caused considerable speculation as to the state of hydrogen(H+, H(n), or H-) entering into reaction.By employment of anapparatus recently described, the action on organic compounds ofatomic hydrogen from a Geissler tube may be ascertained.10 Oleicacid and ethyl phthalate are reduced thereby, but considerablequantities of polymeric materials are produced in each instance.7 M. S. Kharasch and F. R. Darkis, Chem. Reviews, 1928, 5, 571 ; E. P. Carr,A., 1929, 1420; M. L. Sherrill, C. J . Amer. Chem. SOC., 1929, 51, 3041;Baldwin, and D. Haas, ibid., p. 3034; A., 1929, 1419.8 C. Pael and H. Schiedewitz, Ber., 1930, 63, [B], 766; A., 740.9 M.Bourguel, Bull. SOC. chim., 1929, [iv], 45, 1067; A., 1930, 317.Compare J. S. Salkind and V. K. Teterin, J . Russ. Phys. Chem. SOC., 1929,61, 1751 ; A., 1930, 574.10 W. Nagel and E. Tiedernann, Wiss. Ver68. Siemene-Konz., 1929, 8, [2],187; A,, 1930,577ORGANIC UHEMISTRY.-PbT I. 85The action of sulphur l1 and of amines l2 in bringing aboutcis-trans transformation of ethylenic acids has been studied. Theconversion of methyl maleate into methyl fumarate is catalysed byammonia and primary or secondary amines, but not by tertiaryamines. Mechanisms are suggested for this transformation and forthe Knoevenagel reaction : in the one case the disappearance ofthe configurational constraint associated with the double bond andin the other the production of appropriate kationic and anionicforms of the reactants are considered to be the consequence of theformation of co-ordinate links between the hydrogen atom of thebase and carbonyl oxygen >C=O-A HX.For the formerreactivity, however, the suggested mechanism is improbably ofgeneral applicability, since there is reason to believe that in someinstances the cis-trans isomerisation of Knoevenagel products(although not the formation) involves ap,py-isomerisation l3 andwith regard to the latter there is as yet no conclusive evidence toshow that the Knoevenagel reaction is uniquely a reaction involvingthe non-enolised carbonyl group of a ketone or aldehyde, althoughthere is much evidence to show that the reaction is not dependenton the enolisation of the carbonyl g r 0 ~ p .l ~The question of catalytic mechanism arises again in connexionwith the Michael reaction. As the result of the work of J. F.Thorpe lS on the addition of ethyl sodio-a-cyanopropionate toethyl P p-dimethylacrylate the conclusion was unavoidable that inthis instance eithr addition could occur to some extent by partitionniNaof the sodio-addendum in the manner or, ifaddition did indeed involve the partition Na-[-CMe(CN)*CO,EtMe-$!(CN)*CO,Et’in the way usually supposed to be characteristic of the Michaelreaction, then the product could be further alkylated by methyliodide at the a-carbon atom of the resulting sodio-ppy-trimethyl- - Thorpe y- c yanoglutaric ester,held the view that the methyl group in the methyl-cyano-ester andthe hydrogen atom in the corresponding unmethylated cyano-esteractually separated, the sodium atom remaining in the ester residue.NaEtO,C*CMe( CN)*CMe,*CH*CO,Et*l* G.Rankoff, Ber., 1929,62, [B], 2712; 1930,63, [B], 2139; A., 1930, 65,la G. R. Clemo and S. B. Graham, J., 1930, 213; A., 452.l8 E. H. Farmer and J. Ross, J., 1926, 1570; A., 1926, 834.l4 J. C. Bardhan, ibid., 1929, 2225; 1930, 1509; A., 1929, 1462; 1930,Compme A. Michael, Ber., 1900, 38, 3731; A.,1406.1170; C. K. Ingold, a i d . , p. 184; A., 1170.1901, i, 123.Ibid., 1900, 77, 92386 FARMER :Convincing evidence has been furnished to show that in thepresence of a full molecular proportion of sodium ethoxide thepartition of ethyl methylmalonate involves entirely the separationof the methyl group as kationic component; with a fractionalmolecular proportion (conveniently 9) , however, the methyl groupfor the most part remains attached to the ester residue, but to aminor extent (about 10%) separates as the kationic fragment.16The action of sodium ethoxide in small proportion is considered tobe purely catalytic, contributing towards a reaction mechanismcomparable with that encountered in catalytic cis-trans-ethenoidisomerisation, but differing from that which governs addition whenthe addendum is a sodium enolate.17 Strong ground is afforded forpresuming that the characteristic partition of non-alkylated sodio-addenda (sodium enolates) involves the separation of hydrogen andnot of sodium.Investigations relating to the manner of addition to olefins ofhydrogen halides ,l8 carbonyl chloride ,l9 and halogenated amines 2ohave been carried out.The results are of importance as reflectingbroadly the polar influence of the ethylenic substituents on thecompetitive vformation of alternative additive products (>C,X*C,Yand >C,Y*C,X), but as yet the quantitative data available in thisimportant field are few.PolyoleJinic and Polyacet ylenic Compounds.-With the recognitionthat the substances reputed to be aa-dimethylbutadiene 21 andp-cyclopropylpropene 22 are actually ay- and aa-dimethyl- buta-diene respectively, the series of monomethyl- and dimethyl- buta-dienes becomes complete. It is now abundantly clear from themanner in which bromine becomes added to the as-, my-, and py-di-methylbutadienes 23 that the formation of both adjacent andterminal dibromides must be regarded as embodying primaryreactivities of the conjugated molecule : that is to say, the form-ation of as-, EC-, etc., additive compounds is not to be regarded astaking place via the formed molecules of corresponding ap-com-l6 A.Michael and J. Ross, J . Amer. Chem. SOC., 1930, 52, 4600.l7 For non-catalytic addition the addendum in the case of ethyl malonateis represented by H-C(C0,Et) : C(ONa)-OEt, analogous to J. F. Thorpe'srepresentation of ethyl sodiocyanoacetate.la C. C. Coffin, H. 8. Sutherland, and 0. Maass, Canad. J . Res., 1930, 2,267 ; A., 888 ; R . Lespieau, BUZZ.SOC. chim., 1930, [iv], 47, 847 ; A . , 1401lD E. Pace, Gazzetta, 1929, 59, 578; A . , 1929, 1419.2o Z. Foldi, Ber., 1930, 63, [ B ] , 2257; A., 1423.21 0. Diels and K. Alder, AnnaZen, 1929, 470, 98; A., 1929, 819; E. H.Farmer, C. D. Lawrence, and W. D. Scott, J., 1930, 510; A., 572.z2 P. Bruylants, Bull. Acad. roy. Belg., 1908, 1011; A., 1909, i, 226; N. vanKeersbilck, Bull. SOC. chirn. Belg., 1929, 38, 205; A , , 1929, 1163.43 E. H. Farmer, C. D. Lawrence, and W. D. Scott, Zoc. citORGANIC CHEMISTRY .-PBRT I. 87pounds. It is equally apparent that the bromination products,one or all in each case, are not necessarily mobile, The new factsare consistent with the additive mechanism of H. Burton andC. K. IngoldF4 but run counter (as in the writer’s view do all theobservations of the last few years concerning additive processes inrelation to anionotropic change) to a more recent formulation.25The latter is compatible with the possession by a butadiene of twopotential structures, di-ethylenic and conjugated, and obscures thestrong experimental indication that the orientation of the additiveproducts is related to the double degree of unsaturation only to theextent that the latter is able to contribute to the formation of amobile propene system when once simple ethylenic addition hasbeen initiated. In this connexion it is interesting to note thatexamination of the Raman spectra of butadiene, piperylene, iso-prene, and By-dimethylbutadiene has shown no reason for assumingthat the C:C linking in conjugated systems, whether open or closed,is in a state distinct from that of an ordinary double linking of theally1 type.26The variable addition to conjugated substances demonstrated forhalogen addition has now been shown to characterise sodio-esteraddition 27 and hydrogenation (non-catalytic) .28 Esters of themalonic type yield both aP- and as-addition products with the estersof the butadiene-a-carboxylic acids and likewise the reduction ofthe latter acids by metals which react with water gives both Ay- andAs-butenecarboxylic acids.In all these instances there appearsto exist a definite ratio between the amounts of the ap- and as-products formed which depends largely on the constitution of theconjugated compound but to some extent on other factors.Forexample, methyl substitution at the 6-, p-, and pa-carbon atoms inp-vinylacrylic acid causes a change in the proportion of the @- and as-reduction products in the direction required by considerations ofprototropy, with which hydrogen addition has been correlated.2q Itmust be remembered, however, that the experimental methods24 J., 1928, 912; A., 1928, 634. Some misconception has arisen (compareI. E. Muskat and H. E. Northrup, J . Amer. Chern. Soc., 1930, 52, 4048; A.,1553) from a statement of these authors to the effect that in the addition ofhalogens the initial product could only be a 1 : 2-compound. It seems clearfrom the context and from a subsequent re-statement (Ann. Report8, 1928,25, 132) that the authors have in mind the attack by the reagent at a singleethylenic centre and not the actual formation of the ajl-dibromide.26 Ann. Reports, 1929,26, 121.26 A.Dadieu and I(. W. F. Kohlrausch, Ber., 1930, 63, [ B ] , 1657; A,,2 7 E. H. Farmer and T. N. Mehta, J., 1930, 1610; A , , 1163.28 J. T. Evans and E. H. Faxmer, Chem. and Ind., 1928,47,268; J., 1928,1162.1644; A., 1928, 86888 FARMER :available for estimating the @,a6 ratio in all additive processesleave much to be desired and a t present the significance of quantita-tive results is not to be rated too highly.In many reductions of butadiene acids by metals simple reductionproducts are not solely or principally formed, but in their placehydrogenated double molecules appear.29 These are (so far as hasbeen ascertained) linked at the @-carbon atoms and are prone toundergo secondary intramolecular change as illustrated by theformation of a bicyclohexane derivative (A, below) from ethylcrotylidenemalonate. A similar type of reductive polymerisationis that whereby isoprene passes on treatment with potassium andalcohol to a mixture of Pc-, Pq-, and yc-dimethyl-ABf-octadienewhilst py-dimethylbutadiene passes with the same reagents toa mixture of pycq-tetramethyl-A~~-octadiene (B) and methylrubber 30 ; the interesting observation is also made that isoprenemay be simultaneously ethylated and reduced by the action ofpotassium and ethyl bromide to yield S-methyl- As-octene.CH,*QH*QH*y( CO,Et), yH2*CMe:CMe*CH,CH,*CH*CH-C( C02Et), CH,*CMe:CMe*CH,(A*) (B.1The simple addition products of the butadienes are for the mostpart oily substances and no satisfactory means of characterising thehydrocarbons has been available.Owing to the discovery thatmaleic anhydride, acetaldehyde, acraldehyde, acrylic ester, p-benzo-quinone, a-naphthaquinone, and other substances possessing thegroup CH:CH*CO unite quantitatively with the butadienes, fre-quently when the reactants are mixed at room temperature;l anelegant and trustworthy method of characterisation is provided.In addition, the underlying reaction is of great synthetic value andpresents a number of points of theoretical and practical interestwhich may be summarised thus : (1) No single instance has beendiscovered in which other than complete terminal attachment of thenon-dividing addendum occurs, so that all the known products maybe typified by those derived from the combinations isoprene-maleicanhydride, butadiene-acraldehyde, and butndiene-benzoquinone,(I), (11) , and (111) , respectively.29 C.M. Cawley, J. T. Evans, and E. H. Farmer, J., 1930, 622; A., 578.80 T. Midgley, in., and A. L. Heme, J . AmeT. Chem. SOC., 1929,51, 1293,1294; 1930,52,2075,2077; A., 1929, 674; 1930, 888.81 0. Diels and K. Alder, Annalen, 1928, 460, 98; A , , 1926, 1018; 0. Diels,K. Alder, and E. Naujoks, Ber., 1929, 62, [ B ] , 664; A . , 1929, 670; 0. Diels,K. Alder, W. Lubbert, E. Naujoks, F. Querberitz, K. Rohl, and H. Segeberg,Annalen, 1929,470, 62; A,, 1929, 819; 0. Diels, K.Alder, and P. Pries, Ber.,1929, 82, [B], 2081; A., 1929, 1297ORGANIC CHEMISTRY.-PART I. 89II IvCH2CH CH*CHO(111.)vCH2(1.1 (11-1(2) The butadiene acids (e.g., sorbic and muconic acids) yieldcarboxylated tetrahydrophthalic anhydrides with maleic anhy-dride,32 but in the formation of these, py,ap-double bond changemay occur.(3) Cyclic butadienoid compounds (cyclopentadiene, cyclohexadiene, furan, N-methylpyrrole) yield bridged anhydrocyclohexeneson treatment with maleic anhydride; 31 benzoquinone may unitewith one or with two molecular equivalents of open-chain or cyclicbutadienes to yield hydronaphthaquinone and hydroanthraquinonederivatives respectively ; ct-naphthaquinone combines with onemolecular equivalent of open-chain or cyclic butadiene to yieldhydroanthraquinone derivatives.The compounds arising from thecombinations butadiene-ct-naphthaquinone, cyclohexadiene (2 mols.)-benzoquinone ( 1 mol.) , N-methylpyrrole-maleic anhydride arerepresented by (IV), (V), and (VI).CO CH2 CH/ a $ ! H A C H / I \ IfI \scH@ I1 RH QH2 F!W.) (V.1 (VI.)Many of the hydroanthraquinone derivatives, including (V), areconvertible into the corresponding anthraquinones.(4) The hexatrienes and higher poly-ene hydrocarbons also yieldcyclohexene derivatives ; e.g., both the cis- and the trans-form ofhexatriene yield the same ethylidenecyclohexene 32 (VII) withmaleic anhydride, whilst a8-diphenyloctatetrane unites with thesame reagent (even one molecular equivalent only) straightway togive (VIII).34 The course of reaction of the higher hydrocarbons ofstructure Ph-[CH:CH],*Ph appears to be dominated by the strongreactivity of the terminal methine groups, so that with aK-diphenyl-32 E.H. Farmer and F. L. Warren, J., 1929, 897; A., 1929, 812.33 0. Diels, K. Alder, G. Stein, P. Pries, and H. Winckler, Ber., 1929, 62,34 R. KuhnandT. Wagner-Jauregg, Ber., 1930,&3, [B], 2662; A., 1680.[ B ] , 2337; A., 1929, 130390 FARMER :decapentaene, and apparently with still higher members of the series,cyclohexene formation is initiated at both ends of the unsaturatedchain as would be anticipated.C/(VII.)A A[A = *CO*O*CO*](VIII.)When many of the pairs of reactants in the Diels-Alder reactiona.re mixed, colorations rapidly appear, which disappear whenreaction is complete.These probably mark the first stage ofadditi0n,~2,34 presumably corresponding to attachment of theaddendum at one end of the conjugated system. Another interestingobservation concerns the colour of conjugated hydrocarbons them-selves.35 It has been concluded from the study of synthetic andnatural dyes that an aliphatic hydrocarbon must possess 5-6double bonds in unbroken conjugation for colour to develop;moreover, the colour-conferring value of a free carboxyl groupconjugated with double linkages would seem to correspond to about14 double linkages. On this basis the first member of the sorbic acidseries which would be expected to show absorption bands extendinginto the visible part of the spectrum is decatetraenoic acid,CH3-[CH:CH],*C0,H.By the isolation of both octatetraenoicacid and decatetraenoic acid this expectation has been fulfilled,since the former acid is colourless whilst the latter is intenselyyellow.The constitution of the well-known crystalline compound ofisoprene and sulphur dioxide has now been el~cidated.~~ Thesulphur dioxide acts as a non-dividing addendum and in this instancebecomes attached at the terminal carbon atoms of the isoprenechain, yielding P-methyl-As-butene-ct8-sulphone.By the action of iodine (2 atoms) on acetylenic Grignard reagentsof the type CRiCMgX (2 mols.) a series of conjugated diacetylenes(R*CiC*CiCR) has been ~btained.~' These include A*C-decadi-inene,Aq-dodecadi-inene, Ace-tetradecadi-inene and a6-diphenyldi-acetylene. The behaviour of the last of these when catalyticallyhydrogenated is remarkable : the product contains both dihydro-35 R.Kuhn and M. Hoffer, Ber., 1930, 63, [B], 2164; A., 1406.36 E. Eigenberger, J . pr. Chem., 1930, [ii], 127, 307; A., 1405.37 V. Grignard and Tchdoufaki, Compt. Tend., 1929, 188, 357, 1531; A . ,1929, 290, 907ORGANIC CHEMISTRY .-PART I. 91and tetrahydro-derivatives which in form at least are representableas products of as-, apy6-, and aa66-addition.CHPh:C:C:CHPhCH,Ph*CiC*CH,PhCPhiCCiCPh -+ CHPh:CH*CH:CHPh (c~s-c~s)Polymer isation.Hydrocarbons.-The more immediate problems connected withthe formulation of the additive and degradative processes associatedwith the different stages of polymerisation and depolymerisation ofolefinic hydrocarbons concern (1) the structure of dimerides and theuniformity (or otherwise) of the additive processes underlying theirformation, and (2) the genetic relationship of monomerides andhigher polymerides.aayy-tetra-phenyl- A.8-butene, by the act,ion of aluminium chloride, iodine, orsulphuric acid.The last reagent, however, converts the unsaturateddimeride initially produced into a saturated isomeride which (likethe dimeride obtained by the action of aluminium chloride onstilbene) has been deemed to be a derivative of cy~lobutane.~~ Itis now shown that the saturated dimeride is 1 : 3 : 3-triphenyl-hydrindene, formed by a simple cyclisation of the unsaturatedi~omeride.~~ Likewise a specimen of diisobutylene has been shownto contain p8B-trimethyl-AP- and -Aa-pentene~.~OThe formation of cyclobutane derivatives cannot be considered asa characteristic of the dimerisation of mono-olefins : indeed suchpolymerisation is increasingly found to conform to an additivetype which resembles the Michael reaction in that hydrogen separatesfrom the addendum molecule, the components becoming added atthe double bond of the second molecule :as-Diphenylethylene gives an unsaturated dimeride,CPhz:CH[H] + CPh2:CHZ -+ CPh,:CH*CPh,*CH3Addition of precisely this kind appears to account for the syn-theses of open-chain olefins during the pyrolysis of hydrocarbons(p.82) and for the production of Aa-butene and Aa-hexene fromethylene under the action of an electric discharge.41 The latterS.V. Lebedev, I. A. Andreevski, and A. A. Matinschkina, J . Rust?. Phy8.Chem. SOC., 1922,54,223; A., 1923, i, 770; H. Wieland and E. Dorrer, Ber.,1930,63, [ B ] , 404; A., 464.E. Bergmann and H. Weiss, Annalen, 1930, 480, 49, 59; A., 901, 902;C. S. Schoepfle and J. D. Ryan, J . Amer. Chem. SOC., 1930, 52, 4021; A.,1568.40 R. J. McCubbin and H. Adkins, ibid., p. 2547; A., 1017.‘1 G . Mignonac and R. V. de Saint-Aunay, Compt. rend., 1929, 189, 106;A., 1929, 103792 FARMER :result is particularIy noteworthy, since not only is 80-90% of theethylene converted into the butene-hexene mixture, but there isdefinite experimental indication that the polymerisation proceedsin the stagesCH2:CH2.z+ CH,:CH*CH,*CH, % CH2:CH*CH,*CH,*CH2*CH,.The mechanism underlying the polymerisation brought aboutwhen acetylene is submitted to an electric discharge is not quite soclear, but, since a mixture of dipropargyl, y-methyl- Ass-pentadi-inene, and diethenylacetylene is addition probablyproceeds in an analogous way--first giving ethinylethylene, whichunites with acetylene in more than one way.The process wouldseem to become somewhat modified when the polymerisation iseffected by heat.& Acetylene begins to polymerise at about 300°,polymerisation continuing as the only reaction of importance up to600". To a large extent benzene and other aromatic hydrocarbonsare produced. Analogously, methylacetylene might be expectedto yield mesitylene and other aromatic hydrocarbons : instead, itfirst suffers three-carbon isomerisation into allene, ultimatelyyielding (as does allene when taken initially) a mixture of dimeride,trimeride, and higher polymerides, but apparently no aromatichydrocarbons.For the polymerisations brought about by the action of electricdischarge and ultra-violet light 45 on saturated paraffins, however,quite different mechanisms are suggested.These involve notdegradation to olefins, succeeded by polymerisation, but polymeris-ation with hydrogen fission as indicated for the respective processesin (1) and (2) :The products, however, are not wholly saturated.The synthetic relationship of the monomeride, dimeride, trimeride,etc., of olefins such as isobutylene has long been a subject of interestbut has not been satisfactorily determined.It has now been shown,however, that, whereas isobutylene when heated in a glass tube a t43 G. Mignonac and R. V. de Saint-Aunay, Compt. rend., 1929,188, 959; A , ,1929, 637.49 R. N. Pease, J . Amer. Chem. Soc., 1929, 61, 3470; A., 1930, 58; R. N.Meinert and C. D. Hurd, ibid., 1930, 52, 4540; A., 1931, 61; P. SchlapferandM. Brunner, Helv. Chim. Acta, 1930,13, 1125; A., 1400.44 S. C. Lind and G. Glockler, J . Amer. Chem. Xoc., 1929, 51, 3655; A.,1930, 190.4 5 W. Kernula, Row. Chem., 1930,10, 273; A., 887ORGANIC CHEMISTRY .-PART I. 93200" yields only triisobutylene, and when treated with sulphuricacid yields the trimeride with a very small amount of dimeride, yetif polymerised by contact with Florida earth it yields polymeridesrecognisably ranging from di- to hepta-merides along with higherpolymerides which suffer depolymerisation on attempted distill-a t i ~ n .~ ~ Although prolongation of the period of contact of hydro-carbon and earth leads to an increase in the proportion of the morehighly polymerised forms, not all the individual polymerides seemto suffer further polymerisation. Indeed, the changes which takeplace appear to be the following :The polymerising action may be reversed by heating the productsa t 200" in contact with the ~atalyst.~' By studying the decom-position of the individual polymerides it is found that each one ofthe foregoing polymerisations may be reversed but in all cases somemonomeric isobutylene is produced, attributed in the cases of thetetra- and penta-merides to progressive dissociation of the initialdi- and tri-meric forms.Practical dficulties have prevented astudy of the decomposition of the higher polymerides, but it hasbeen noted that prolonged contact of the polymeric forms withfloridin at a high temperature causes the production of stable formsof high molecular weight. Diisobutylene is the most stable poly-meric variety and the stability rapidly decreases with increasingmolecular weight.HaZogeno-ok$ns.-Allyl chloride is converted in the absence ofair, slowly on keeping, but more rapidly under the influence ofultra-violet light, into polyallyl chloride, (C3.H5Cl)n, which is not asingle substance but a mixture of polymerides48 (mean value ofn = lo), formed by normal valency unions and probably possessingthe structure :CHz*CH(CH2Cl)*[CH,*CH(CHzCl)],*CH,~CH(CH2Cl) *The polymeride may be separated by fractional precipitation andextraction methods into a series of polymerides (n = 9,12,5,25,11,and 7) which decrease in solubility with increase in molecular weight.Vinyl bromide and as-dichloroethylene also polymerise in thelight to yield non-homogeneous substances, the components of whichrepresent different stages of polymerisation.49 Owing to inferior4 6 S.V. Lebedev and C. G. Kobliansky, Ber., 1930,63, [ B ] , 103; A., 316,4 7 Idem, ibid., p. 1432; A., 1017.48 H. Staudinger and T. Fleitmann, Anmlen, 1930, 480, 92; A,, 889.dU H. Staudinger, M.Brunner, and W. Feist, Hdv. Chirn. Actu, 1930, 13,805; A , , 1402; H. Staudinger and W. Feiet, ibid., p. 832; A., 140294 FARMER :solubility in cold and instability (leading to dehydrobromination)in hot solvents the molecular weight cannot be determined. Thepolyvinyl bromide obtained from the former suffers replacement ofthe halogen atoms by methyl groups when treated with zinc methyl(ethyl groups with zinc ethyl) to yield a hydrocarbon (C,H,), whichresembles cyclocaoutchouc and is less unsaturated than caoutchouc ;from indications afforded by reduction experiments it appears toconsist of a mixture of long straight-chain compounds. Theas-polydichloroethylene from the latter may be fractionated byextraction from benzene and reduced to hydrocarbons of widelydiffering molecular weight.It is completely saturated and to it isassigned the formula :* CH2*CC12*[CH2*CCI,],CH,*CC12 * * [X = 50-1001.Po@-esters.-The polymerism of the glycol esters of dibasic acidsis a polymerism of intermolecular condensation and not of theaddition of monomeric species. When in the interaction ofR(C02H), with R’(OH), the number of atoms in the system[*CO*R*CO*O*R’-O*] is too great to permit of five- or six-memberedring formation, the reaction becomes polymolecular and the poly-merides are usually linear in type. The ethylene, trimethylene,hexamethylene, and decamethylene esters of malonic, adipic, andsebacic acids have been obtained 50 as crystalline compounds and allare highly polymerised : the structural unit ranges from 7 to 22atoms and the molecular weight from 2300 (ethylene malonate) to5000 (trimethylene sebacate).Ethylene and trimethylene carbon-ates are obtainable, as would be expected, in the monomeric form,but the latter can be converted on heating with potassium carbonateinto a true polymeride, from which the monomeric ester is regener-ated on distillation in a vacuum.Neutral and acidic ethylene succinates showing different degreesof polymerisation have been prepared,51 and mixed polymerideshave been obtained by the interaction of ethylene glycol withequivalent quantities of succinic and sebacic acids, but not byfusing together (polymerised) ethylene succinate and ethylenesebacate. Both chemical and osmotic methods give concordantvalues for the molecular weights of these substances.Monomeric ethylene oxalate is obtainable but gradually poly-merises a t room temperature and rapidly on heating.By extractionof a partly polymerised ester with acetonitrile, soluble and insoluble6O W. H. Carothers and J. A. Arvin, J . Amer. Chem. SOC., 1929, 51, 2560;A., 1929, 1165; W. H. Carothers and F. J. van Natta, ibid., 1930, 52, 314;A , , 319.51 W. H. Carothers and G. L. Dorough, ibid., p. 711; A . , 452; W. H.Carothers, J. A. Arvin, and G. L. Dorough, ibid., p. 3292; A,, 1272ORGANIC CHEMISTRY.-PART I. 95polymerides have been extracted, either of which can arise spontane-ously from the other on keeping at the ordinary temperature.A similar process of pol yintermolecular reaction occurs whenc-hydroxydecoic acid is heated alone or with various inert solvents.52Mixtures of acids of the typeHO*[CH,],~CO,~([CH,]~*CO,.),.[CH,l,.CO,Hare produced, the components of which are partly separable byfractional crystallisation, and have molecular weights ranging fromabout 1000 to 9000.These complex acids yield the original acidon hydrolysis.Dirneric Acetoins.-An important example which diff ers from allthe polymeric types discussed above is that of acetoin.63 Observ-ations of the ultra-violet absorption spectrum of the monomericform of this substance indicate the presence of the carbonyl group andhence of the preponderating, if not exclusive, existence of theketo-form, COMe*CHMe*OH. There are two crystalline dimeridesof acetoin which give almost the same extinction curve in alcoholas the monomeride.It is clear that dissolution in alcohol does notcause fission of the dimerides, since they can be recovered crystallineafter some hours, and molecular-weight determinations of the iso-meride of higher melting point in the boiling solvent give normalvalues which decrease only when ebullition is prolonged. In the twocrystalline forms it would seem, therefore, that the two acetoinmolecules are united in such a manner that the keto-group, andconsequently the whole acetoin molecule, remains unchanged in itsmain valency arrangement.The possibility that groups other than carbonyl can give a similarextinction curve is negatived by observations with epichlorohydrinand triacetyl glucose anhydride.A dioxan structure is excluded,since dioxan itself is non-absorbent. Two ethereal oxygen atomsattached to the same carbon atom do not cause absorption, as isshown by the behaviour of methoxyacetaldehyde dimethylacetal.The dimeric methylacetal of acetoin does not exhibit the character-istic ketonic absorption, and hence is regarded as a dioxan derivative,CHMe*CMe( OMe)-O<CI~(~M~),CHM~>O, a view that is in harmony with itsreldtively di6cult polymerisation. From the fact that the dimericacetoins have considerably higher melting points when very rapidlyheated than when very slowly heated it appears probable that thetransformation temperature of the dimerides into the monomeridelies below the melting point.62 W.H. Lycan and R. Adam, J. Amer. Chem. SOC., 1929, 51, 3450; A.,63 W. Dirscherl and E. Braun, Ber., 1930, 63, [B], 416; A., 454.1930, 6596 FARMER :To account for the properties of dimeric acetoin a structure,[Me*hO*CHMe*OHI,, has been proposed in which the association ofmolecules is dependent on the exercise of definitely located auxiliaryvalency forces. On account of the divergence of views as to thenature of the associative links holding in such highly polymerisedsubstances as the polysaccharides, the further investigation of suchrelatively simple examples of residual valency polymerism as appear )from the evidence discussed) to be presented by the acetoins will beawaited with interest.Alcohols and Ketones.It was clearly desirable, for reasons discussed in last year’s Report,that all supposed esterifications in the p-position of glycerol shouldbe subjected to careful scrutiny.Further study of the constitutionof a number of supposed P-monoglycerides 64 supports the generalconclusion that previous announcements of the isolation of suchp-forms are incorrect. The instance of the @-benzoate of B. Helferichand H. Sieber 55 is, however, an exception and the claim of theseauthors to have isolated the first true p-glyceride is upheld. Like-wise, the assumption of a@- and ay-isomerism in diglycerides isshown by further cases to be based frequently on insufficient evidence.A list of apparently trustworthy methods for preparing a-, p-, a@-,ay-, and say-esters and ethers is given.It is pointed out that in some of the instances the cause of theproduction of unexpected isomerides is doubtless inherent in thesyntheses themselves : for instance, the production of ap- or ay-ethersfrom both ap- and cry-dihalogenohydrins is probably to be attributedto intermediate ap-oxide formation. This explanation may extendto similar preparations of the glycerol esters. Nevertheless, inter-changes of acid radicals with one another, and also with differentradicals, take place so easily that an explanation of these changesnot involving a large or difEcult movement of such heavy radicalsas the stearyl and palmityl groups is needed.If a tendency towards ortho-ester formation, as originally sug-gested by E.Fischer, be taken into consideration, the migration ofacid radicals can be represented merely by a rearrangement ofvalencies in which little or no relative movement of the atomsthemselves has to be presumed.ICH2*O*CO*C17H,5ay-Distearin ,%palmitate.CH2*O*C0 GI,€€, 5/3y-Dis tearin a-palmitate.64 A.Fairbourne, J., 1930, 369; A., 574.2. physiol. Chem., 1927, 170, 31; A., 1928, 44ORGANIC CHESI1STRY.-PART I. 97Moreover, if conditions can exist in which the Hantzsch type ofcarboxyl group actually occurs, the above two formula may becomeidentical ,C15H31*c[0 o * * * * ? H 2 * . * * . . . . YH . . . . E}c*c17H35CH,*O*CO*C, ,H3,and in any case, a tendency towards the transitory formation ofsuch @-oxide rings is held to be probable. On this basis themigrations which so frequently appear to take place while otherreactions are in progress (e.g., the migration of an acyl radicalsimultaneously with the elimination of a halogen atom, even if theglycerol molecule does not contain a hydroxyl group) can beexplained.The acid complexes formed between boric acid and glycols areshown by methods not involving their separation from solution tohave the composition HBD,, D representing a diol residue.56 Onesuch method is based on hydrogen-ion determinations in aqueoussolutions of boric acid and diol in various proportions, considerationof the equilibria involved giving a relation - ApR = (n/2) log a,connecting the difference of pa of two solutions and the ratio a of theamounts of diol present in each, n being the number of moleculesof diol combining with 1 mol.of boric acid. A second methodinvolves the consideration of the partition of hydroxyl ions betweenthe acid complex and free boric acid during neutralisation, and athird depends on cryoscopic measurements. The structure andmode of ionisation of these complexes are considered to be repre-sented by the general formulaA phenomenon which appears to involve the formation of ringcomplexes of somewhat similar character to the foregoing, and hasa direct bearing on the spatial distribution of the hydroxyl groupsof glycols, is revealed by the study of the solubility of arseniccompounds, particularly of arsinoacetic acid, in 99% acetic acid inthe presence of various It is found that two adjacenthydroxyl groups in the glycol generally increase the solubility ofarsinoacetic acid, arsenic trioxide, and resorcinolarsinic acid, andthis effect is intensified when three or four hydroxyl groups are ina position favourable to the formation of a five-membered ring, asin ethylene glycol, glycerol, pyrocatechol, etc.p-Glycols andm- and p-dihydric phenols have a smaller effect. Stereoisomerides56 J. Boeseken, N. Verrnaas, and A. T. Kuchlin, Rec. tmv. chim., 1930, 49,5 7 B. Englund, Svenek Kern. T'idskr., 1928, 40, 278; A., 1929, 52; J . pr.711; A . , 1018.Chem., 1929, [ii], 122, 121; 1930, [ii], 124, 191; A., 1929, 946; 1930, 330.REP.-VOL. XXVII. 98 FaRMER :with different spatial configuration of the hydroxyl groups havedifferent effects, e.g., active and meso-forms of tartaric acid, cis- andtruns-forms of cyclohexanediol.The magnitude of the effect isaltered by substitution; it is increased by the introduction of alkylgroups, but the extent of increase is dependent on the number andnature of the substituents. The influence of carboxyl or carbonylgroups, e.g., in succinic acid or benzil, on the solubility is small.Investigation of the rate of dehydration of the unsaturated glycolCMe,( OH)*CH:CH*CMe,*OH in water in the presence of hydrogenions 58 shows the strong effect produced by the spatial configuration.The dehydration of the cis-form of the diol in solutions of mineraland organic acids is catalysed by hydrogen ions. The reaction isunimolecular and complete, the oxide being the only product.Measurements of the velocity at different temperatures, employinghydrochloric acid, show the temperature coefficient to be high, whilstcomparative measurements made in different acids show that thevelocity of catalysis is' only approximately proportional to thehydrogen-ion concentration, increasing more rapidly than thelatter. So far as the experiments show, the velocity in weakly acidmedia is constant, the acidity being unaffected by addition of theditertiary glycol ; in more strongly acid solution, the velocitycoefficient decreases slightly but regularly as the concentration of theglycol increases.Dehydration of the trans-form, on the other hand,is slow, yielding not a cyclic oxide but open-chain polyolefins.The result of replacing the hydroxyl groups in the acetylenicglycol CMe,( OH)*CiC*CMe,*OH by bromine is of interest.Thechange has been effected 59 with phosphorus tribromide and, inaddition to a product which doubtless has the constitutionCMe,Br*CiC*CMe2Br, two other isomeric dibromides have beenobtained.CMe,:CBr*CBr:CMe,obtainable from the first on heating, or directly from the glycol bythe action of hydrobromic acid ; to the other dibromide, no formulahas been definitely assigned, although on the basis of its oxidationproducts it cyclic formula has been thought to apply. Neverthelessit seems to the writer that the oxidation products, while not lendingsupport to this suggestion, are precisely those to be expected froman allene derivative of the formula CMe,:C:CBr*CMe,Br, both thisand the isomeric diolefin being produced during, or subsequentlyto, replacement of hydroxyl, by anionotropic change.One of these appears to be the compound6 8 M.Bourguel and R. Rambaud, Bull. SOC. chim., 1930, [iv], 47, 173;69 V. N. Krestinski and L. J. Bashenova-Koslovskaia, J . Ru88. Phys. Chem.A., 574.SOC., 1929, 01, 1691; A., 1930, 574ORGAN10 aHEMISTRY.-PART I. 99Various useful methods have been devised for the production ofacetals and ketals from glycols, hydroxy-acids, and hydroxy-ketones. Derivatives of the enolic form of acetol have beenobtained by reacting on isopropylideneglycerol a-monochlorohydrinwith potassium hydroxide, and a dimeric derivative of the enolicform of methylglyoxal has been analogously obtained from thep - toluenesulp hon y 1 derivative of g 1 y ceraldeh y de met h ylc y clo -acetal; 6O the diethylacetal of hydroxyacetone is shown to beobtainable 61 if the acetol acetate is allowed to react with ethylorthoformate and the product hydrolysed with lime, although theinteraction of free acetol or acetol formate with the same reagentyields only acetol ethylcydoacetal ; ethylidene derivatives of glycolsand hydroxy-acids can be obtained by interaction of the latter withacetylene in the presence of a catalyst.G2 In the last reaction thecatalysts employed to effect condensation are solutions of boron orsilicon fluorides in alcohols with mercuric oxide.The activeconstituents of these solutions, which possess high electrical con-ductivity, are probably hydrofluoboric and hydrofluosilicic acids.The compound BF,,Et,O formed by dissolving boron trifluoride inether is also stated to be efficacious as a catalyst.An examination of the thermal decomposition of acetone in thegaseous state carried out several years ago showed that between506" and 632" the process constitutes a homogeneous unimolecularreaction, the products of decomposition being about one-halfsaturated hydrocarbons and hydrogen, one-third carbon monoxide,and the remainder carbon dioxide and ethylene.63 A new examin-ation 64 has shown that for every 100 mols.of acetone vapourpassed (with nitrogen) through a quartz tube heated in an electricfurnace, approximately 60 mols. of keten can be recovered. Hencethe primary reaction in the unimolecular decomposition is probablythe separation of a molecule 'of methane and the formation of keten,which undergoes a bimolecular decomposition into ethylene andcarbon monoxide at the high temperature.If this is the correctexplanation, the proportions of methane, ethylene, and carbonmonoxide which would then be found agree fairly closely with theprevious experimental result.[ B ] , 1732; A., 1164.ao H. 0. L. Fischer, E. Baer, L. Feldmann, and L. Ahlstrom, Ber., 1930,63,V.V.Evlampiev, J. Ru88.Phys. Chem. Soc., 1929,61,2017; A., 1930,580.62 J. A. Nieuwlend, R. R. Vogt, and W. L. Fookey, J . Amer. Chem. SOC.,C . N. Hinshelwood and W. K. Hutchiscn, Proc. Roy. SOC., 1926, [A],13* F. 0. Rice and R.E. Vollrath, Proc. Nat. Acad. Sci., 1929, 15, 702;1930,52, 1018; A., 745.111, 245; A., 1926, 691.A., 1029, 1425100 FARMER :The extent of enolisation produced in a number of ketones on theaddition of various organo-magnesium halides seems to bear norelation to the structure of the given ket0ne,~5 but, on the whole,increases with the atomic weight of the halide present in the Grignardreagent, and is greater where tertiary organic radicals are presentthan primary or secondary. Enolisation, using magnesium tert . -butyl chloride, amounts for di-n-butyl ketone and carvone to about20%, for acetophenone 31%, for cyclopentanone 326y0, for thujone41 yo, for 4-methylcyclohexanone 46% ; for cyclohexanone 50.5%, formenthone 51y0, and for mesityl oxide 60%.I n relation to thesevalues cyclohexanone contains originally 8.2 yo of enol, 4-methylcyclo-hexanone 6-3%, and mesityl oxide 6.3%, whilst the remainder arenormally exclusively in the keto-form. No connexion appears thusto exist between the tendency towards allelotropism of a given sub-stance and its degree of enolisation under the influence of theGrignard reagent.As a result of a determination of the extent of enolisation ofethyl acetoacetate and acetylacetone in alkaline solution, P. Gross-mann came to the conclusion that, with a considerable excess ofalkali, the high results obtained corresponded with the presence of adienol. In determining the amount of enol the usual practica ofacidifying the solution before treatment with bromine was replacedby direct addition of an acid bromine solution and removal of theexcess of bromine by aniline hydrochloride.The question has beenre-examined by A. Hantzsch and W. Krober,67 who state thattitration of alkaline solutions of ethyl acetoacetate and of acetyl-acetone with bromine solutions shows that the excess of brominetaken up by the enolic compound varies with the concentration ofthe bromine solution and is due to secondary reactions. Measure-ments of the amount of hydrogen liberated by the action of acetyl-acetone and of benzoylacetone on sodium or potassium suspendedin benzene or xylene show that only one atom of the alkali metal istaken up by the enol. The formula COMe-CH:C(ONa)*OEt forethyl sodioacetoacetate and the existence of dienol salts with thegroup *C( ONa):C:C( ONa)* proposed by Grossmann are consideredto be incorrect.Distillation of free ethyl acetoacetate a t the ordinary temperatureand mm.pressure in quartz or Pyrex, but not in soft, glassvessels, has yielded fractions containing 30---40~0 of the enol, thehalf-life period of which is about 500 hours.68 These are approxim-65 V. Grignard and H. Blanchon, Rocz. Chem., 1929,9, 547; A., 1930, 67.8 6 2. physikal. Chem., 1924, 109, 305; A., 1924, i, 834.6 7 lbid., 1930, 147, 293; A., 1021.6 8 F. 0. Rice and J. J. Sullivan, J . Arner. Chem. SOC., 1928,50, 3048ORGANIC CHEMISTRY.-PART I. 101ately ten times as stable as any previously obtained. No substancehas, however, been found capable of stabilising the product andattempts to increase the stability by removing traces of water withsilica gel or acetyl chloride proved unsuccessful.In this connexionit is of interest that dimethylpyruvic acid as obtained by distillationat atmospheric pressure is the pure keto-form; when this is dis-solved in water, an equilibrium between enolic and ketonic formsis obtained, a 1-OM-solution containing o.4770, a 0-1M-solution0.28y0, and a 0-O1M-solution only a trace of the enolic form.69After addition of a small amount of alkali a third form is reportedto be detectable spectrographically.Bromomalondialdehyde behaves in aqueous solution as a trueacid.70 In alcohol the keto-enol equilibrium, as determined byK. Meyer’s bromination method, is established only after 48 hoursand corresponds with 24% of the enol a t the ordinary temperature.A rise in temperature raises the proportion of the enol.The sodium salts of acetone, methyl propyl ketone, camphor, andfenchone have been prepared by the action on the ketones of sodiumin liquid ammonia; benzophenone yields with sodamide andpotassamide the compounds C13Hlo0,NaNH, and C,,Hl0O,NK3,respec tively.71The possibility of synthesising cis- and trans-forms of n-alkylidene-acetones has been demonstrated in the instance of butylidene-acetone.72 The two forms of this ap-unsaturated ketone resistconfigurational change and interconversion has been effected onlyin the direction of cis-+ trans, through the hydrobromide.Theself-additive tendency of these substances in the presence of alkalinereagents has not permitted examination of the relationship existingbetween geometrical configuration and @,py-isornerisation, but ithas been possible by the action of dilute acid to convert the corre-sponding py-ketone into a mixture of cis and trans @-forms.Optimum conditions for the condensation of ketones by hydrogenchloride are obtained when the molecular ratio of acid to ketone is2 : 3.73 It is a notable fact that with the exception of methyl ethylketone reaction in the presence of this condensing agent is confhedto the ketone group of one molecule and the methyl group of thesecond molecule.Methyl ethyl ketone suffers condensation (inconformity with former results for an acid condensing agent) at the69 C.Fromageot and S. Perraud, Biochem. Z., 1930, 223, 213; A., 1272.70 J. Grard, Compt. rend., 1930, 190, 187; A., 324.7 1 H. H. Strain, J . Amer. Chem. Soc., 1930,52, 3383; A., 1273.72 E. N. Eccott and R. P. Linstead, J., 1930,905.73 V. Grignard and J. Cologne, Compt. rend., 1930,190, 1349; A., 1022.Compare H. Stobbe andF. J. Wilson, Annalen, 1910,374, 237; J., 1910, 97, 1722102 FARMER :ethyl group of the second molecule, yielding y-chloro-ys-dimethyl-hexan- @-one. This gives with alkali the corresponding ketone,CMeEt:CMe*COMe. If hydrogen chloride be replaced by hydrogenbromide or hydrogen iodide in the same molecular ratio of acid toketone, higher yields of the condensation products are obtained ;moreover, the condensation of methyl ketones with secondarycarbon groups, but not of ketones with tertiary groups, is facilitated.Carbohydrates.The synthesis of 2 : 3 : 4 : 5 : 6-penta-acetyl glucose, a true open-chain aldehyde form of a sugar,74 has been followed by the synthesisof several analogous compounds.Penta-acetyl galactose 75 andtetra-acetyl Z-arabinose,76 derived from the diethylmercaptals ofthe appropriate sugars, have rotation values in chloroform of - 25"and - 65" respectively, showing that the carbonyl group can producea relatively high rotation in spite of the absence of rings. Aldehydo-pentabenzoyl glucose has been obtained in an analogous manner.77Other notable syntheses in the monosaccharide group are those ofd-glucoheptulose,78 obtained by the Lobry de Bruyn rearrangementof d-a-glucoheptose and clearly related to the glucoheptulose ofBertrand and Nitzberg 79 as the optical antipode, Z-threose 8O (insolution and in the form of its osazone), and epifucose (Z-talo-methylose) .81The elucidation of the constitution of the sugar acetones hasresulted in the extensive employment of the isopropylidene deriv-atives of sugars, sugar mercaptals, and sugar acids for syntheticpurposes.This is exemplified in the preparation of a, number ofgem-dialkyl derivatives of d-galactose 82 and of fructofuranoseand in the synthesis of the 4-methyl derivatives of d-mannose 84 andd-galactose.85 The dicarbonates of glucose, fructose, mannose, andarabinose, which have now been obtained as well-defined and easilycharacterised products,86 will doubtless prove of equal utility, and74 Ann. Reporte, 1929, 26, 92.7 5 M.L. Wolfrom, J. Amer. Chem. Soc., 1930, 62,2464; A., 1023.76 M. L. Wolfrom and M. R. Newlin, ibid., p. 3619; A., 1411.7 7 P. Brig1 and H. Muhlschlegel, Ber., 1930, 63, [B], 1551; A., 1022.78 W. C. Austin, J . Amer. Chem. SOC,, 1930, 52, 2106; A., 894.7O Compt. rend., 1928, 186, 925, 1172, 1773; A., 1928, 510, 620, 867.80 V. Deulofeu, J., 1929, 2458; A., 1930, 68.81 E. VotoEek and V. KuEerenko, J . Czech. Chem. Comm., 1930, 2, 47; A.,82 H. Ohle and C. Dambergis, Annalen, 1930, 481, 255; A,, 1274.83 H. Ohle and 0. Hecht, ibid., p. 233; A., 1274.84 E. Pacsu and C. von Kary, Ber., 1929, 62, [B], 2811; A., 1930, 70.85 E. Pacsu and A.Lob, a i d . , p. 3104; A., 1930, 197.86 W. N. Haworth and C. R. Porter, J., 1930, 151; A., 326.325ORGANIC CHEMISTRY .-PART I. 103for certain purposes, owing to their less ready hydrolysis by diluteacids to the parent sugars and their immediate attack by even coldalkali, will prove superior to the sugar-acetones. The constitutionalformulse suggested for these substances are based on the similarityin properties to the diacetones.Formulation of Sugars.-A considerable amount of new workrelating to the representation of the sugars as pyranose and furanosering-structures has been carried out. This includes the isolation ofmissing forms in one or other series, and the investigation of thecomparative stability and optical rotatory powers of representativesof both series.New lactones of Z-rhamnonic acid *' and 2 : 3 : 4-tri-methylrhamnonic acid 88 have been isolated, the former of whichprobably, and the latter more certainly, has the pyranose structureof a true a-lactone ; a-methylmannofuranoside, tetramethylmanno-f uranose ,s9 trimethyl -1yxof uranoside , and trime t hy I-ly xof uranosehave also been obtained and found to resemble closely other y-sugarderivatives.Although representatives of the two types of ring-structure showa large difference in the ease of oxidation by permanganate in thepresence of an acid phosphate b ~ f f e r , ~ l yet an attempt to estimatethe comparative stability of pyranose and furanose sugar derivativeshas met with only slight success; 92 observations relating to thedifferential absorption of ultra-violet light by the two types of ringstructure have disclosed only very slight spectrographic difference^.^^Various examples are known of the wandering of acyl groupslinked with polyhydric alcohol residues. One of the fist to observethe change was E.Fischer,9* who suggested that the migrationmechanism might be explained by the intermediate formation of anortho-carbonic ester group in the manner :$!H,*OAc TH,*OAc $!H,*OAcCH,*OH CH,*O>C<OH CH2*OAcThe adoption of Fischer's explanation has been shown to provide aE. L. Jackson and C. S. Hudson, J . Amer. Chem. SOC., 1930, 52, 1270;A., 744.a0 J. Avery and E. L. Hirst, J., 1929, 2466; A., 1930, 68; F. E. Wright,J . Amer. Chem. Soc., 1930,52, 1276; A., 744.8s W.N. Haworth, E. L. Hirst, and J. I. Webb, J., 1930, 651 ; A., 748.90 H. G. Bott, E. L. Hirst, and J. A. B. Smith, &id., p. 668; A., 747.QH-OAC -+ QH-0 CH, + QH*OHC. H. Whitnah and J. E. Milbery, J . Amer. Chem. SOC., 1930, 52, 1627 ;A , , 748.92 H. Ohle and V. Marecek, Ber., 1930, 63, [B], 612; A., 581.93 F. Goos, H. H. Schlubach, and G. A. Schroter, 2. phyaiol. Chem., 1930,94 Ber., 1920, 53, 1624; A., 1920, i, S08.186, 148; A., 455104 FdRMER :wayg5 not only of representing the simple migration of acetyl asillustrated in the conversion of 3- into 6-monoacetyl glucose deriv-atives 96 but also of relating 1 : 2 : 3 : 4-tetra-acetyl @-glucose (I) 97and 2 : 3 : 4 : 6-tetra-acetyl @-glucose (11) 98 t o the supposed1 : 2 : 3 : 6-tetra-acetyl glucose of B.Helferich and W. K l e i r ~ . ~ ~There is definite evidence for the view that the supposed 1 : 2 : 3 : 6-tetra-acetyl glucose which is formed from, and is known to exist inequilibrium with, (I) in alkaline solution represents the cyclic inter-mediate form (111) produced during the migration of an acetylgroup from the position C, to C, in the carbon chain of (I) when thelatter is alkylated with methyl iodide and silver oxide. The finalproduct so obtained is the methyl glucoside (IV) corresponding to,and derivable from, (11).OAc OAc (h ?HCH,*OH CH2-O-V-CH, bH,H 1-0 OAc H 1-0 H 1-0 OMe H 1-0 OH@L7>l -+ @=>I --+ i<OLFr>I f- i@->lAcO 1 I H AcO I 1 H AcO 1 1 H AcO 1 i HH OAc H OAc H OAc H OAc(1.1 (111.) (IV.) (11.)The migration of the 4- rather than the l-acetyl group, as wasoriginally suggested, is not finally excluded,l but would seem to beunlikely in view of the fact that a further transposition of acetylresidues must then occur when the resultant compound undergoesconversion into 2 : 3 : 4 : 6-tetra-acetyl p-methylglucoside (IV).A similar explanation has been applied to the formation of theanomalous third (" y ") forms of triacetyl methylrhamnoside, tetra-acetyl methylmannoside , and hepta-acetyl chlorornaltose.2 Theexistence of the first of these had been tentatively explained byassuming a novel form of stereoisomerism; now, however, theresistance to hydrolysis of one of the four acetyl groups in thiscompound-the feature distinguishing it from the two already9 5 W.N. Haworth, E. L. Hirst, and E. G. Teece, J., 1930, 1405; 8., 1022.96 K. Josephson, Ber., 1929, 62, [B], 317, 1913; A . , 1929, 428, 1278;Annalen, 1929, 472, 217; A., 1929, 1044; Svensk Kern. Tidskr., 1929, 41,99; A., 1929, 912.9 7 J. W. H. Oldham, J . , 1925,127, 2840; A., 1926, 151.98 E. Fischer and K. Delbruck, Ber., 1909, 42, 2778; A., 1909, i, 633.O9 Annalen, 1927, 455, 173; A , , 1927, 858.1 Compare B. Helferich, Ber., 1930, 63, [B], 2142; A . , 1411.2 H. G. Bott, W. N. Haworth, and E. L. Hirst, J . , 1930, 1395; A., 1024;K. Freudenberg, Natumuise., 1930, 18, 393; A., 894; K. Freudenberg andH. Scholz, Ber., 1930,63, [ B ] , 1969; A . , 1412.8 W. N. Haworth, E. L. Hirst, and E.J. Miller, J., 1929, 2469; A., 1930,68ORGANIC CHEMISTRY.-PART I. 105known triacetyl methylrhamnosides (ct- and p-forms)-is at*tributedto its participation in the complex Ig>C<E%e . According to thenew explanation, which receives some support from absorptionmeasurements,4 the third or obstructed varieties of the three corn-pounds are to be represented thus :QH3 MeO-C-0H OAc OAc H H,C*OACThird form of triacetyl Third form of tetra-acetyl Third form of hepta-aceby1me thylrhamnoside. methylmannoside. chlo romaltose.It is contended by C. S. Hudson that change of ring form may anddoes occur during the methylation of sugars, a circumstance held tovitiate certain of the conclusions of W. N. Haworth with respect tothe structural representation of the sugars.New formulz deducedby applying the principle of optical superposition to available opticaldata have accordingly been put forward for various mono- andpoly-saccliarides.5 Quite apart, however, from the coherence of thechemical evidence which supports the existing formulation, there isimportant new evidence that the principle of optical superpositiondoes not apply uniformly throughout the sugar group.6 I n thefructose series, for example, difficulties are encountered in applyingHudson’s metliods,7 since the differences in the activities of thecc-series in different solvents are unusually great, whereas smallerdifferences are observed in the p-series : hence the magnitude of theincrement depends greatly on the choice of solvent and it is con-cluded from the data obtained for a variety of solvents that thc:increments calculated from the values of the aldose series cannot beapplied in the ketose series, in which the values are markedly higher.The limitations to the usefulness of the optical method in diagnosingconstitution also appear from a study of derivatives of 5-p-toluene-sulphonyl-3 : 6-anhydroglucose 8 and from other observation^.^E.Braun, Naturwiss., 1930, 18, 393; A., 896; Bey., 1930, 63, [ B ] , 1072;J. Amer. Chem. SOC., 1930, 52, 1680, 1707; A., 747.W. N. Haworth, Nature, 1930, 126, 238; A., 1273; J . Amer. Chem. SOC.,H. H. Schlubach and G. A. Schroter, Ber., 1930, 63, [B], 364; A., 456.H. Ohle and E. Euler, ibid., p. 1796; A., 1165.F. Micheel, ibid., p.347; A., 455; H. H. Schlubach and R. Gilbert,A., 1411.1930, 52, 4169.ibid., p. 2292; A.. 1412.D 106 FARMER :From measurements of the rotation of Q- and p-glucose andct-methylglucoside in borax solutions 10 it appears that the glucosidicand 2-carbon hydroxyl groups are essential for the reaction withborate, and occupy in a-glucose cis-positions. A means of determin-ing directly the configuration of ct- and p-forms in the sugar serieshas been sought, and consistent results have been obtained in con-necting the reactivity of a number of glucosyl halides towardstrimethylamine with the cis- or trans-configuration of the substituentgroups at the 1- and 2-carbon atoms of the chain.ll Only a cis-relationship of these groups would seem to permit of quaternarysalt formation with the amine, but the method is not generallyapplicable in this simple form, since the interaction of acetobromo-I-rhamnose with trimethylamine is found to lead to the productionof a diacetyl anhydrorhamnose. On the assumption that Waldeninversion does not occur at the C,-atom during ring closure theanhydride ring is regarded as produced by the removal of brominealong with the 4-acetyl group, a procedure which may be renderedpossible by the approach in space of the two groups in a folded phaseof the p p a n ring (formula A).It is suggested that the correspond-ing stability of acetobromomannose towards trimethylamine maybe due to the greater distancegroup as indicated in formula(A) cH3of the bromine atom from the 4-acetylB.Further progress has been made in the investigation of twonaturally occurring sugars, digitoxose, and hamamelose (hama-melihexose).To the former, which had been shown by H. Kiliani 12to be a 2 : 6-deoxyhexosej a formula has been assigned : l3 for thelatter, obtained as methylhamameloside from the hamameli-tannindescribed by Freudenberg and Bliimmel,14 a branched-chain formuladifferent from that originally suggested by the latter authors hasbeen advanced. l510 M. Levy, J . Biol. Chem., 1929,84, 749, 763; A., 1930, 69.11 F. Micheel and H. Michoel, Ber., 1930, 63, [B], 386; A., 455.12 Ber., 1922, 55, [B], 75; A., 1922, i, 224.13 F. Micheel, Ber., 1930, 63, [B], 347; A., 455.14 Annalen, 1924, 440, 45; A., 1925, i, 51.l5 0.T. Schmidt, Annalen, 1929,476, 250; A., 1930, 197ORGANIC CHEMISTRY.-PART I. 107$?H,*OHQH*OH 1HO*Q--$?H*OMeQHOTH2 H*$?*OHH&H CH,*OHDigitoxose. Methylhamameloside.H* *OH YH- 0MeThe probability that a genetic relationship explains the existencetogether in natural products of sugars and of pyran or pyrone nuclei16is increased by a demonstration of the convertibility of acetobromo-glucose and acet obromogalac tose into tetra-acetyl 2 - hydroxyglucaland tetra-acetyl 2-hydroxygalactal respectively, and thencesmoothly into diacetylkojic acid.17Synthetic GZucosides.-The nature of the reagents employed toeffect the conversion of glucosyl halides into alkyl glucosides wouldappear to determine, to some extent at least, the a- or the @-form ofthe product.It is possible to obtain either an a- or a p-methyl-glucoside from both 2-trichloroacetyl-3 : 4 : 6-triacetyl-(3-glucosylchloride and 3 : 4 : 6-triacetyl-~-glucosyl chloride by selectingappropriate conditions. This may be due to each reagent havingits own isomerising effect, but it is considered to be more probablethat the first stage in these processes consists in the addition of thereagent to the glucosyl halide and that the subsequent behaviourof the additive compound so obtained is determined by the nature ofthe reacting systems.ls Direct conversion of p- into a-glucosideshas been found to result from the action of titanium tetrachloridein chloroform,19 and a-alkylglucosides admixed only with minorproportions of the corresponding 13-forms have been obtained byheating the dibenzylmercaptals of the aldomonoses with mercuricchloride dissolved in the requisite alcohol.20It has now been established that dihydroxyanthraquinonediglucosides, including such as contain the sugar residues attachedto the same benzene nucleus, can exist.21 The preparation of analizarin diglucoside should therefore be possible.a-Hydroxylgroups, when protected by (3-hydroxyl groups, cannot be caused toreact with halogeno-sugars by using an excess of the latter, by16 W. N. Haworth, " Constitution of Sugars," p. 38.1 7 K. Maurer, Ber., 1930, 63, [BJ, 25; A., 326; K. Maurer and A. Muller,18 W. J. Hickinbottom, J., 1930, 1338; A., 1023.19 E. Pacsu, J . Amer. Chem.SOC., 1930, 52, 2563; A., 1023.20 E. Pacsu and N. Ticharich, Bey., 1929, 62, [B], 3008; A., 1930, 197.21 A. Mi.iller, ibid., p. 2793; A., 1930, 71; A. Robertson, J., 1930, 1136;ibid., p. 2069; A., 1412.A., 895108 FARMER :prolonging the reaction, or by raising the temperature. It appearspossible, therefore, that ruberythric acid is a monobioside, butowing to the demonstrated difference of its octa-acetyl derivativefrom that of an octa-acetyl maltoside derived synthetically fromalizarin it is apparently not a maltoside. Rubiadin glucoside hasnow been shown definitely by synthesis to be 3-p-glucosidoxy-1 - hy drox y -2-methylanthraquinone .22Di- and Tri-saccharides.In supplementing the evidence furnished by methylation methodsas to the correct formulation of disaccharides, use has been made ofthe 1 : 2- and 5 : 6-unsaturated derivatives of sugars (glucals andglucoseens). Thus new evidence in favou? of the C,-linking of thecomponents in melibiose is provided by the behaviour of melibialtaken in conjunction with the capacity of the sugar to form both1 : 4- and 1 : 5-glucosides and lac tone^.^^ New evidence as to themanner of coupling and the pyranose ring structure of trehalose islikewise afforded by the formation of a bis-triphenylmethane deriv-ative of this sugar and of a non-reducing trehalosediene which ishydrolysable to isorhamn~nose.~~Gentiobial, a new compound of the glucal class, has been shownto yield a mixture of hydroglucal and glucose when submitted to theaction of emulsin after reduction.25 It is considered, therefore, tobe a 6-gl~cosidoglucal, the glucal structure containing a pyran ring.Analogously, the already known cellobial and lactal are consideredto be 4-glucosidoglucose and 4-galactosidoglucal respectively.Glucal itself passes rapidly on oxidation with perbenzoic acid tomannose,26 which fact corresponds with an earlier observation ofM.Bergmann and his collaborators that lactal yields 4-galactosido-mannose with the same reagent.27 It has been found, however, that3-methyl glucal yields 3-methyl glucose with perbenzoic acid 28and that the 4-galactosidomannose from lactal is a mixture of atleast two sugars.29A new disaccharide ketose has been derived from a-lactose by the22 E. T. Jones and A.Robertson, J . , 1930, 1699; A., 1167.23 P. A. Levene and E. Jorpes, J . Biol. Chem., 1930, 86, 403; A , . 749.24 H. Bredereck, Ber., 1930, 63, [ B ] , 959; A., 748.2 5 M. Bergmann and W. Freudenberg, ibid., 1929, 62, [ B ] , 2783; A.,28 C. Tanaka, Bull. Chem. SOC. Japan, 1930, 5, 214; A., 1273.2 7 Annalen, 1923, 434, 79; A., 1924, i, 265.2 8 P. A. Levene and A. L. Raymond, J . Biol. Chem., 1930, 88, 513; A.,Z g A. J. Watters and C. S. Hudson, J . Amer. Chem. SOC., 1930, 52, 3472;1930, 70.1411.A., 1275ORGANIC CHEMISTRY.-PART I. 109Lobry de Bruyn method. This substance, d-lactulose,3° whichyields d-fructose and d-galactose on hydrolysis, is considered to be4- p-d-galactosido-a-d-fructose.In connexion with the synthesis of sucrose, recent condensationsof tetra-acetyl y-fructose with tetra-acetyl glucose have yieldedocta-acetyl isosucrose as the only crystallisable product (occasionallyocta-acetyl isotrehalose is isolated) .31 As isosucrose is less stablethan sucrose, it is improbable that octa-acetyl sucrose is first formed.The isolation of two varieties of octa-acetyl sucrose which have thesame optical rotation in chloroform but different melting points hasbeen These do not correspond with the " A " and " B "varieties of sucrose but are considered to be stable and labile forms.The investigation of several natural products has proceeded astage further.From the calcium aldobionate obtained by hydrolysisof gum arabic, a crystalline aldobionic acid has been isolated whichyields a dicarboxybionic acid on oxidation.The fission productsof both acids confirm the view that the aldobionic acid is aglycuronogalactose and the slow rate of hydrolysis of the two methyl-glucosides derived from the aldobionic acid shows that both of thesepossess the pyranose structure.% The aldobionic acid is thereforeregarded as glycurono-3(or 6)-~-galactose.The third sugar constituent of scammonin has been recognised asrhodeose, which remains together with rhamnose when the hydrolysisproduct of scammonin is fermented to remove glucose.34 Thesugar of ct-crocin when acetylated yields a product which is found tobe identical with octa-acetyl genti~biose.~~Acid hydrolysis of the glucomannan obtainable from " konjakpowder " (powdered tubers of Amorphophallus Eonjack, C.Koch)confirms the view that this polysaccharide contains mannose andglucose in the ratio of 2 : l.36 Glucomannan gives a triacetate andyields by acetolysis a mixture from which glucomannotriose, gluco-mannobiose, and mannobiose may be obtained by deacetylation.On hydrolysis the triose yields two molecules of mannose and onemolecule of glucose ; similarly, glucomannobiose yields equal30 E. M. Montgomery and C. S. Hudson, J . Amer. Chem. SOC., 1930, 5.2,31 ( S i r ) J. C. Irvine and J. W. H. Oldham, ibid., 1929, 51,3609; A., 1930,3% A. Pictet, Helv. Chim. Acta, 1930, 13, 698; A., 1166.33 M. Heidelberger and F. $1. Kendall, J . Biol. Chem., 1929, 84, 639; A.,34 E. VotoEek and F. Valentin, J . Czech. Chem.Comm., 1929, 1, 606; A.,35 P. Karrer and K. Miki, Helv. Chirn. Acta, 1929,12, 985; A., 1929, 1427.36 K. Nishida and H. Hashima, J . Dept. Agric. Kyushu, 1930, 2, 277; A . ,2101 ; A., 894.197.1930, 66.1930, 71.1413110 FBRMER :quantities of mannose and glucose, but mannobiose yields mannosePolysaccharides.Uncertainty as to the trustworthiness of the cryoscopic methodfor the determination of the true molecular weights of the poly-saccharides and their derivatives enhances the interest attached tothe investigation of the relationship between viscosity and molecularcondition. This relationship is the subject of a series of papers byH. Staudinger and his ~ollaborators,~7 the theoretical considerationsdeveloped being based on the following hypotheses.(1) Variationin the specific viscosity, qm., of a colloidally dissolved substance withpressure is an indication of structure in solution which may becaused by the presence of macromolecules in such concentrationthat they are mutually impeditive. (2) The specific viscosity of themacromolecular hydrocarbons increases proportionately with theconcentration in dilute solution but more rapidly than the concen-tration in concentrated sol solution and in the region of gel solution.(3) Approximate constancy in the specific viscosity of a solution overa considerable range of temperatures is evidence of the presence ofmacromolecules in solution and against that of strongly solvatedmicelles. (4) Measurements of viscosity in different solvents affordevidence of the influence of the medium on the macromolecules.Several polysaccharides and their derivatives have been examinedexperimentally and the deductions from the viscosity of theirsolutions are referred to in the sections below.Inulin and 1,ichenin.-It has been reported that the molecularweight of inulin in liquid ammonia and in molten acetamide is inagreement with the formula (C6Hl,O5), and that the isolation of thepolymerised product from the latter mixture yields an inulan ofcomposition ( C6H1005)2 which is freely soluble in water but becomesas insoluble in cold water as inulin on keeping.Observations of asimilar kind have been recorded with respect to the depolymerisingaction on inulin of glycer01,~8 acetamide 39 and f~rmamide,~O but thereality of the alleged depolymerisation is denied by E.Berner.*lThis author suggests that specimens of inulin and other polysacch-37 H. Staudinger and R. Nodzu, Ber., 1930, 63, [ B ] , 721; A., 571; H.Staudinger and W. Heuer, ibid., p. 222; A., 333; H. Staudinger, K. Frey,R. Signer, W. Starek, and G. Widmer, ibid., p. 2308; A . , 1415; H. Staudingerand 0. Schweitzer, ibid., p. 2317; A , , 1414.38 H. Vogel, Ber., 1929, 62, [ B ] , 2980; A., 1930, 198; H. H. Schlubachand H. Elsner, ibid., 1930, 63, [B], 362; A., 456.39 J. Reilly and P. P. Donovan, Sci. Proc. Roy. Dublin SOC., 1930, 19, 409;a,, 896.4O H. Pringsheim and W. G. Hensel, Ber., 1930, 63, [B], 1096; A., 896.4 1 E. Berner, ibid., pp. 1356, 2760; A., 1025.onlyORGANIC CHEMISTRY.-PART I.111arides of apparently low molecular weight (determined cryoscopic-ally) may be obtained by treatment with glycerol or ethylene glycolat the ordinary temperature, but attributes the observed effect to aphysico-chemical process caused by the adsorption by the poly-saccharide of appreciable quantities of the " depolymerising " andprecipitating media, whereby water solubility is conferred. Theadsorbed materials may only be removed by protracted heating in avacuum.The correctness of this conclusion is contested by H. H. Schlu-bach 42 and H. Pringsheim and their collaborators and it is pointedout by the former that inulin, when treated wth benzamide, yieldsa product which is separable into two portions of different specificrotation; also the values recorded by different workers for thespecific rotation of depolymerised products are such as to permitthe products to be divided into two groups, (1) those which have thesame specific rotations as the initial inulin, into which they can betransformed, and (2) those which differ in specific rotation from theoriginal material and are not capable of spontaneous reconversion.Viscosity measurements 44 of inulin dissolved in formamide showthat its behaviour differs greittly from that of polystyrene or balatasolutions.Since qSp. is much greater at lower than at higher tem-peratures, a change in the structure of the colloidal particles is heldto occur, which is attributed to alteration of the co-ordinate linkingsof the molecules among themselves and with the solvent; thesechanges are reversible, since particles of the original size result whenthe solutions are cooled.Examination of solutions of lichenin in formamide shows thesolute to be present in the molecular form a t great dilution.In themore concentrated solutions co-ordinative union is considered toexist between solvent and solute and between the molecules ofsolute; the latter linkings are resolved when the temperature israised and for this reason a more pronounced fall in viscosity isobserved than in more dilute solutions, in which only the co-ordin-ative linkings between solute and solvent are ruptured. Themolecular weight of lichenin is markedly higher than that ofinulin; the chain appears to contain about 300 unit molecules.Starch.-The experimental conditions necessary for effecting asharp separation of the two main constituents of potato starch havebeen investigated.45 The a-amylose from the outer envelope of the42 H.H. Schlubach and H. Elmer, Ber., p. 2302; A., 1415.43 H. Pringsheim, J. Reilly, W. G. Hensel, W. Burmeister, P. P. Donovan,44 H. Staudinger and 0. Schweitzer, ibid., p. 2317 ; A., 1414.4 6 M. E. Baldwin, J . Amer. Chem. SOC., 1930, 52, 2907; A . , 1167.and N. Hayes, ibid., p. 2636112 FARMER :grains forms 84 & 1% of the original starch; the p-amylose fromthe interior of the grains constitutes within 1% the remainder of thestarch. The properties of these preparations are described and it issuggested that the great difference in the temperature coefficientsof the rotations of the two components probably accounts for thedivergent values previously recorded.Products having the characteristics of Pringsheim's amylobioseand amylotriose have been obtained from amylose and amylopectin,respectively, by the action of cold concentrated hydrochloric acid 46as described by this worker and his collaborators.Evidence isfurnished to show that they are not definite compounds and theirproperties are quite inconsistent with the formulae assigned to them.47Products of similar character are stated to be obtainable by theaction of cold hydrochloric acid on glycogen and on glucose.Viscosity measurements carried out on solutions of potato starchor soluble starch in formamide reveal a behaviour differing com-pletely from that of polystyrenes and caoutchouc and markedlyfrom that of lichenin.Since even dilute solutions do not obey theHagen-Poiseuille law, deductions concerning molecular weight areinadmissible. Freely mobile colloid molecules are absent. Thespecific viscosity diminishes with rise in temperature, the starchsuffering change. Since the qSp./c values in quite dilute solutions ofdiffering concentration are not constant, irregular changes in thestructure appear to occur ; it cannot therefore be determined whethermacromolecules are present in solution under definite conditions.It is thought probable that the colloidal particles of starch are com-posed of associations of extremely unstable, readily cracked mole-cules, and that the solution contains molecular aggregates (micelles)and not macromolecules.Cellulose .-All the isolable products of the degradation of celluloseacetates reduce alkaline iodine solution and the iodine consumptionis stated to be an accurate and reproducible measure of the freealdehydic groups and the molecular weight of the compounds.48Technical cellulose acetate has been further degraded with hydrogenbromide in ghcial acetic acid, and the product separated by hotmethyl alcohol into two portions, acetylsaccharides A and B.Theiodine numbers of the respective materials indicate the presence inthem of mixtures of polysaccharides containing as an average 8 and9-11 hexose units. The product obtained by the acetolysis of46 R.Weidenhagen and A. Wolf, 8. Ver. deut. Zucker-Ind., 1930, 80, 265;'' Compare Ber., 1926, 59, [B], 991, 096, 1001; A . , 1926, 715.48 M. Bergmann and H. Machemer, ibid., 1930, 63, [B], 316; A., 457.Compare R. Willstatter and G. Schudel, ibid., 1918, 51, 7 8 0 ; A., 1918, ii, 461.A., 1168ORGANIC CHEMISTRY .-PART I. 113cellulose according to the method of K. Hess and H. Friese49 haebeen separated into a number of fractions which appear to contain8-13 hexose residues.To the latter substance, the hexa-acetyl biosan considered byHess and Friese to be a true dimeride of the fundamental cellulosemolecule, a molecular weight of 556587 has recently beenassigned 50 : this value, determined in acetic acid, is considered to bea true one, although the behaviour of different samples of acetone-soluble cellulose acetate in acetic acid is irregular and the relationshipof cellulose acetate to glacial acetic acid apparently complex.Thevalue is rejected by other workers 51 on the grounds of the unsuit-ability of the cryoscopic method for determining the (very large)molecular weight of this siibstance and of the demonstrable non-homogeneity of the biosan acetate.With regard to the more complex acetolysis products of cellulose,the terminal groups form so small a proportion of the molecule thattheir accurate determination by the iodine method is held to beimpossible; 52 nevertheless, on the basis of iodine consumption, thechain in cellulose itself has been computed to contain 50 glucoseresidues on an average as against 25-30 such residues in the starchmolecule.53The course of degradation of the cellulose molecule on heatingwith acetic acid and zinc chloride has been followed by viscositymeasurement^.^^ Degradation of the initial cellulose moleculeoccurs very rapidly, but the simpler products are much moreresistant. The initial, highly viscous solutions are computed tocontain cellulose triacetates of average degree of polymerisation60-100; after 20 hours’ action, the degree is reduced to 10. Atthe ordinary temperature, reaction proceeds extremely slowly,giving products of a degree of polymerisation 150. After 7 days at30°, the degree is 130 and after 10 days it is 100. Since nativecellulose is more highly polymerised than the most complex of itsacetates, its molecular weight is considered to be above 24,000, andthe cellulose molecule probably contains a chain of 500--1000glucose residues, thus having dimensions similar to those of thecaoutchouc molecule.The simpler cellulose acetates dissolve without swelling to give** Annalen, 1926, 450, 40; A., 1927, 44.6o K.Hem Ber., 1930, 63, [ R ] , 518; A., 456.51 K. Freudenberg, E. Bruch, and H. Rau, ibid., 1929, 62, [ B ] , 3078; A.,1930, 198; K. Freudenberg and E. Bruch, ibid., 1930, 63, [ B ] , 535; As, 457:K. H. Meyer and H. Hopff, ibid., 1930, 63, [ B ] , 790; A . , 750.62 H. Staudinger and H. Freudenberger, ibid., p. 2331 ; A . , 1416.s8 K. Freudenberg, W. Kuhn, W. Diirr, F. Bolz, and G. Steinbrunn, ibid.,p.1510; A., 1025114 BENNETT AND CHAPMBN:mobile solutions, the viscosity of which increases proportionally tothe concentration ; slightly degraded cellulose acetates swell verymarkedly, their viscosity in solution increasing far more rapidy thanthe concentration, so that very viscous solutions can be obtainedat relatively high dilution. I n them, the total region of the macro-molecules is greater than the available volume in relatively dilutesolution. I n place of sols in which the macromolecules have freemovement, these viscous solutions correspond to gels in which themacromolecules impede one another. A 10-triacetylcelloglucandiacetate, OAc[C,H,O,Ac,],,Ac, is stated to behave in solution likea simple substance and the gel condition is not reached until theconcentration attains 2.2% ; with a 150-triacetylcelloglucan diacetatethe transition between sol and gel lies at 1.4%.According to further indications afforded by viscosity measure-ments 44 cellulose triacetate in s-tetrachloroethane and m-cresolappears to form associations of molecules in concentrated solutionwhich become resolved when the temperature is raised.I n dilutesolution the change of the colloidal particles is uniform and is heldto be attributable to a loosening of the co-ordinative linkingsbetween the macromolecules and those of the solvent. Since withcellulose acetate, lichenin, a'nd inulin, as with the highly complexhydrocarbons, the specific viscosity of the solutions is the same atdifferent temperatures, the identity of the colloidal particles with tliemacromolecules is regarded as established.Dibenzylcelluloseexhibits abnormal behaviour in s-tetrachloroethane, whilst methyl-cellulose (OMe = 38%) shows still more marked divergence fromthe Hagen-Poiseuille law, in the same solvent. With cellulosenitrate, the measurements of viscosity are particularly difficult tointerpret, since mechanical treatment of the solution causes greatermobility.E. H. FARMER.PART II.-HOMOCYCLIC DIVISION.The Pinacol-Pinacolin and Related Rearrangements(compare Ann. Reports, 1923,20,115 ; 1925,22,116 ; 1928,25,134).DURING the last few years a considerable volume of work hasappeared dealing with the pinacol-pinacolin change and the relatedrearrangements of the substituted ethylene oxides and of thOR(XBN1C CHEMISTRY.-PART II.115a~-amino-alcohols.~-55~ *Oy61 Many data have been collected andrepeated attempts have been made to enunciate general rulesP. J. Montagne and S. A. Koopal, Rec. trav. chim., 1910, 29, 136, 150 ;A., 1910, i, 323, 324.a S . A. Koopal, ibid., 1915, 34, 115; A., 1915, i, 693.S. Danilov, Ber., 1927, 60, [B], 2390; A., 1928, 64.S . Danilov and E. Venus-Danilova, Ber., 1926, 59, [B], 377; A., 1926,519.ti Idem, ibid., p: 1032; A., 1926, 726.Idem, Ber., 1927, 60, [B], 1050; A,, 1927, 661.E. Venus-Danilova, Ber., 1928, 61, [B], 1954; A., 1928, 1244.Idem, J. Rum. Phtye. Clbem. SOC., 1929, 61, 53; A., 1929, 1070.M. Godchot and G. Cauquil, Compt. rend., 1928,186, 767 ; A., 1928,521.M.Gomberg and J. C. Bailar, jun., J. Arner. Chem. SOC., 1929,51, 2229;A., 1929, 1067.l1 R. Lagrave, Ann. Chim., 1927, [ix], 8, 363; A., 1928, 270.12 L. Leers, Bull. SOC. chim., 1926, [iv], 39, 651 ; A., 1926, 711.l3 (Mlle.) J. LBvy, ibid., 1921, [iv], 29, 820; A., 1921, i, 788.l5 (Mlle.) J. L6vy and F. Gombinska, Compt. rend., 1929,188,711 ; A., 1929,l6 (Mlle.) J. LBvy and R. Lagrave, Bull. SOC. chim., 1927, [iv], 41, 833; A.,l7 (Mlle.) J . LBvy and M. Sfiras, Compt. rend., 1927, 184, 1335; A., 1927,l8 Idem, ibid., 1928, 187, 45; A., 1928, 888.lo (Mlle.) J. LBvy and A. Tabart, ibid., 1929,188, 402; A., 1929, 448.*O (Mlle.) J. LBvy and P. Weill, ibid., 1927, 185, 135; A., 1927, 880.21 R. Locquin and L. Leers, Bull. SOC. chim., 1926, [iv], 39, 655; A., 1926,22 P.Nicolle, ibid., p. 55; A., 1926, 382.23 M. Migita, Bull. Chem. SOC. Japan, 1928, 3, 308; 1929, 4, 57; A., 1929,24 W. Madelung and M. Oberwegner, Ber., 1927 60 [B], 2469; A., 1928,25 L. Orthner, Annalen, 1927, 459, 217; A., 1928, 184.26 A. McKenzie and W. S. Dennler, J., 1926, 1596; A., 1926, 834.27 Idem, Ber., 1927, 60, [ B ] , 220; A., 1927, 243.28 A. McKenzie and M. S. Lesslie, Ber., 1929, 62, [B], 288; A., 1929, 317.2D A. McKenzie and A. K. Mills, ibid., p. 284; A., 1929, 317.3o Idem, ibid., p. 1784; A., 1929, 1066.31 A. McKenzie, A. K. Mills, and J. R. Myles, Ber., 1930, 63, [B], 90432 A. McKenzie and R. Roger, J., 1927, 671 ; A., 1927, 457.33 Idem, Ber., 1929, 62, [B], 272; A., 1929, 317.34 A. McKenzie, R.Roger, and G. 0. Wills, J., 1926, 779; A., 1926, 610.35 M. Tiffeneau and (Mlle.) J. Uvy, Bull. SOC. chirn., 1923, [iv], 33, 769;Idem, ibid., 1926, [iv], 39, 67; A., 1926, 399.555.1927, 872.662.711.448, 675.171.788.A., 1923, i, 789.Idem, ibid., p. 735; A., 1923, i, 788.37 Idem, Convpt. rend., 1926,182, 391 ; A., 1926, 383.8 8 Idem, Bull. SOC. chim., 1926, [iv], 39, 763; A., 1920, 818116 BENNETT AND CHAPMAN :regarding the changes. The interpretation of the data is, however,not it simple matter and the complications attending it will thereforebe considered in some detail, as sufficient allowance has not alwaysbeen made for them in the discussion of this subject.Although essentially similar in character, the rearrangements canbe conveniently classified into three main groups : 36 (a) the pina-colinic change proper,CRR1( OH)*C( OH)R2R3 I H $ CRR1R2*COR3(b) the semihydrobenzoinic change in which the tertiary hydroxylCRR1R2*CH0CHRRWOR2group is lost, and (c) the semipinacolinic change in which thesecondary hydroxyl group is lost,R*CO*CHR1R2CRR1(OH)*C(OH)HR2 --\ - - % O f orCRR1(OH)*C(OH)HR2 -- --$of or ' R ~ ~ O ~ C H R R ~The pinacolinic change proper presents fewest complications ininterpretation.The mode of elimination of the elements of waterfrom the two hydroxyl groups of the pinacol molecule determineswhich of the two central carbon atoms shall become the ketonicgroup and thus fixes the general direction of the rearrangement.39 M. Tiffeneau and (Mlle.) J.Ldvy, Compt. rend., 1926, 183, 969; A., 1927,40 Idem, ibid., p. 1112; A., 1927, 153.41 Idem, Compt. rend., 1927, 184, 1465; A., 1927, 769.42 Idem, Bull. SOC. chim., 1927, [iv], 41, 1351; A., 1927, 1184.43 Idem, Compt. rend., 1928, 186, 84; A., 1928, 286.44 M. Tiffeneau and A. Ordkhoff, ibid., 1920,171, 400; A., 1920, i, 672.4 5 Idern, ibid., p. 473; A., 1920, i, 673; Bull. SOC. chim., 1921, [iv], 29,429, 445; A., 1921, i, 585, 566.46 Idem, Compt. rend., 1921, 172, 387; A., 1921, i, 243; Bull. SOC. chim.,1921, [iv], 29, 809; A., 1921, i, 788.4' A. OrBkhoff and M. Tiffeneau, Bull. SOC. chim., 1922, [iv], 31, 253; A.,1922, i, 458.48 M. Tiffeneau and A. Orekhoff, ibid., 1923, [iv], 33, 195; A., 1923, i, 333.49 A. Or6khoff and M.Tiffeneau, Compt. rend., 1924,178, 1619; A., 1924,146.i, 729.Idem, Bull. SOC. chim., 1925, [iv], 37, 1410; A., 1926, 172.51 Idem, Compt. rend., 1926, 182, 67; A., 1926, 171.s2 Idem, Bull. SOC. chim., 1927, [iv], 41, 1174; A., 1027, 1076.63 S . Yamaguchi, Bull. Chem. SOC. Japan, 1926,1, 64; A., 1928, 727.64 Ber., 1929, 62, [B], 1598; A., 1929, 929.55 E. Luce, Compt. rend., 1925, 180, 145; A., 1925, i, 263ORGANIC CHEMISTRY.-PART 11. 117In compounds of the type CRR(OH)*C(OH)RIR1 the nature of thefinal product is determined by this elimination factor alone and astudy of the rearrangements of such compounds completely con-firms the view 56 that the elimination of the hydroxyl group occurspreferentially from the carbon atom to which are attached thegroups with the greatest capacity for electron release.57Further support for this view is forthcoming from the data withregard to the less symmetrical pinacols.e.g.> 79 l 2 9 143 159 1 6 9 229 383 50When all the radicals attached to the central carbon atoms arealiphatic the products of the change are usually mixtures involvingelimination in both directions.From the data available it is also possible to arrange certainpairs of groups in the order in which they facilitate the fission ofthe adjacent hydroxyl l49 1 9 9 2% 339 3 7 9 46When the substituted ethylene oxides are converted into theisomeric ketonic substances by heating, the fission of the C-0 bondfollows the same 113 1 5 5 1 8 s 37s 38 a few apparent exceptions,which occur under drastic conditions,l' being possibly explicable bya further isomerisation of the primary product.On the other hand the direction of rearrangement of the ap-amino-alcohols appears to be determined by the position of the amino-group eliminated, the oxygen of the hydroxyl group remaining inplace irrespective of the character of the adjacent groups.28323 3 4 9 399 65Thus, for example, p-amino-act-diphenyl-n-propyl alcohol (I) isconverted by nitrous acid into methyldeoxybenzoin (II),= whilst(1.1 CPh,(OH)*CHMe*NH, -+ Ph*CO*CHPhMe (11.)in the corresponding pinacol, loss of water occurs by removal of thehydroxyl group from the a-position. 68 Pinacols have, however,been obtained by deamination of some a@-amino-alcohols,32 and thepossibility of their formation as intermediate products in other casesmust not be overlooked.66 C.K. Ingold, Ann. Reports, 1928, 25, 134.67 For examples, see list included in Ref. 2 (p. 115).68 R. Stoermer, E. Schenck zu Schweinsberg, (Fr.) Sibbern-Sibbers, endP. Riebel, Ber., 1906, 39, 2288; A., 1906, i, 681118 BENNETT AND CHAPMAN :Although the general direction of a pinacolinic change is deter-mined by the mode of elimination of the elements of water or offission of the oxide linkage in an ethylene oxide, the nature of theproduct obtained depends also on the relative facility with whichthe two groups concerned will migrate from one carbon atom tothe other. For example :R\ R- C*COR2 (R1 migrates)p-K::] / RJ‘A R\R- C*COR1 ( R2 migrates) ?R dThe differences in “ migratory aptitude ’’ of various groups are bestobserved in the rearrangement of compounds of type (111) in whichR(111.) Rl>V-K;lOH OHthe two hydroxyl groups are identically situated and the eliminationfactor is therefore not involved.Investigation of the rearrangementof such compounds 1 9 2910, 609 has shown that the following groupscan be arranged in order of decreasing “migratory aptitude”thus :p-anisybp-tolyl, p-diphenyl,a-nsphthyl >p-isopropylphenyl>p -ethylphenyl>p - fluorophenyl, } phenylp-iodophenyl f >p-bromophenyl, p-chlorophenyl>o- or m-chloro- or -bromo-phenyl\ >m-tolyl>m-anisylThe ease with which these different groups migrate within themolecule is evidently not related simply to any one of their pro-perties and more data will be required before the factors governing“ migratory aptitude ” in the pinacol-pinacolin system can be fullyunderstood, especially as it has not yet been established that thisis a property of the group independent of its environment.Numerous attempts have been made to deduce the relative“ migratory aptitudes ” of various groups from observation of therearrangement of compounds other than type (111), but the inter-pretation of the results obtained is complicated by the two furtherconsiderations discussed below and it is inadvisable to draw fromthese results any definite conclusions.When one or more-of the four radicals attached to the two centralcarbon atoms are replaced by hydrogen atoms it is sometimespossible for a given product to be formed in more than one way.For example ORGANIC CHEMISTRY.-PART II.119The transformation of (IV) into (V) by the action of dilute or con-centrated sulphuric acid Z6 may occur either as a semihydrobenzoinicchange with migration of a hydrogen atom or by a vinyl dehydration,followed by ketonisation of the resultant enol. It is not permissible,therefore, to draw any conclusion from this rearrangement as to therelative ease of migration of hydrogen and the cr-naphthyl group,and similar caution must be exercised in the interpretation of thenumerous other cases of apparent semihydrobenzoinic change whichYet another complication attends the interpretation of therearrangement of ap-glycols having hydrogen atoms attached to thea- or p-carbon atom.It has been shown 3-89 2% 5l9 59 that aldehydesof the type CR3*CH0 in the presence of cold concentrated sulphuricacid, or even sometimes on boiling with the dilute acid, may undergorearrangement into isomeric ketones :involve the same dilemma.6, 14, 141% 22,44349, 50, 52CR,*CHO -+ CHR,*COR.The reagents that are known to bring about the conversion of thealdehydes into the ketones are amongst those most commonlyemployed to effect the pinacol-pinacolin change, and it is thereforeimpossible as a rule to decide whether a given ketone, obtainedapparently by a direct semipinacolinic rearrangement, is really theprimary product.R-COCHRRlSemipinacolinic change/:>?-OH OHSemihydrobenzoinic changeIt is clear, however, that the aldehyde is not necessarily an inter-s* s.Danilov, J . Russ. PhY8. Chern. soc., 1919, 61, 97120 BENNETT AND CHAPMAN :mediate product, as R. Roger and A. McKenzie 33 have shown thatthe conversion of d- p-hydroxy- p-phenyl- aa-dibenzylethanol (VI)into ay-diphenyl-y-benzylacetone (VII) by boiling dilute sulphuricacid does not involve complete loss of optical activity as would occurif the ketone were formed by way of the aldehyde (VIII) (comparealso A. McKenzie and W. S. Dennler 27 and J. L6vy and P. Weill ,O).,CH,Ph CH2Ph\ CH,PhH-C-CO*CH,Ph OHC*dCH,PhPh/ \Ph:>?%CH,Ph OH OHWI.) (VII.) (VIII.)This rearrangement of trisubstituted acetaldehydes affords anexplanation of the change in product which often accompanies achange of reagent.4, 6, 133 367 4 0 9 4* For example :PhH > VOH -KE OHPhO C H O e eI MeAldehydes are usually formed under the milder conditions andketones with the more drastic agents.The deduction of any series of " migratory aptitudes " from theresults of apparent semipinacolinic changes 43 is evidently unsafeunless the mechanism of the rearrangement can be independentlydemonstrated in each case.have described a rearrangementof the pinacol-pinacolin type involving as-migration.H. Kleinfeller and F.EckertPh Ph PhPh*CO--#-C33-(i-COPh I -- boiling + Ph*CO*(!iLC32-CO*COPhalcoholic HCl Ph OH OHOther Molecular Rearrangements.A new triad isomeric change has been discovered by A. Schonbergand L.von Vargha.62 The diarylthioncarbonates (I) were con-verted into the corresponding thiolcarbonates (11) when heated a tabout 300". The rearrangement has been employed for the prepar-A. Orkkhoff and J. Brouty, Bull. SOC. chim., 1930, [iv], 47, 621 ; A., 1179.61 J. C. Bailar, jun., J . Amer. Chern. SOC., 1930,52, 3596; A., 1438.62 Ber., 1930, 63, [B], 178; A., 320ORGANIC CHEMISTRY.-PART II. 121ation from the corresponding phenols of some disulphides otherwiseaccessible with diEculty. 63The reversible rearrangement of the triarylbenzenylamidinesreferred to in last year’s Report has now been investigated in greaterdetail a and has been shown to be intramolecular by tests similarto those applied to the imino-ether rearrangement. The relativemobilities of different migrating groups Ar (I11 and IV) were inthe order p-tolyl<phenyl<p-chlorophenyl, whilst replacementof p-tolyl as the stationary group Arl by p-chlorophenyl resultedin a retardation of interconversion.These results are exactlyparallel with those obtained for the rearrangement of imino-arylethers into arnidesG6 and it would appear that the changes areidentical in mechanism.Consideration of the positions of equilibrium of several pairs ofisomeric amidines has shown that the original electronic formulationof these rearrangements is untenable, but all the known facts are inagreement with the view 65 that the migrating group Ar first attractsone or both of the lone electrons of the nitrogen atom to which it isgoing and then, retaining its newly acquired electrons, releases theoriginal binding pair.This view has the advantage, not only offurnishing a picture of these rearrangements, but also of revealinga close connexion between them and a number of other changes, bothintra- and inter-molecular, which at first sight appear quite dis-similar. For instance, an intermolecular reaction of this kind is thedisplacement of chlorine by iodine in various alkyl chlorides whenthese are heated with an alkali iodide.67 The replace.ment may beregarded as an intermolecular migration of the radical from chlorineto iodine and there is strong evidence that the exchange takes placeby a preliminary combination of the alkyl chloride molecule and theiodide ion, followed by ejection of a chlorion.In the same classalso come reactions like the fission of diary1 sthers by piperidine,686* A. Schanberg, L. von Vargha, and W. Paul, Annulen, 1930, 483, 107.A. W. Chapman, J., 1930, 2458; A. W. Chapman and C. H. Perrott,ibid., p. 2462.61 Ann. Reportcr, 1929, 26, 123.A. W. Chapman, J., 1927, 1743; A., 1927, 874.Compare Ann. Reports, 1929, 26, 137. 6 8 Ibid., p. 133122 BENNETT AND CHAPMAN :an intermolecular migration of an aryl group from oxygen to nitrogen.Conversely the imino-ether and amidine changes may be regardedas intramolecular displacement reactions.The establishment of the constitution (V) for iso- @-naphtholsulphide 69 reveals the isomeric change of this compound under theinfluence of heat or alkalis 70 as the migration of a hydroxynaphthylgroup from oxygen to sulphur.This appears to be an intramolecular change comparable both withthe thion-thiol (and imino-ether) rearrangement and with thereplacement reactions already discussed.The migration of thep-hydroxynaphthyl radical from oxygen to sulphur is compensatedby the reverse migration of the proton. The ortho-quinonoiddehydrosulphide (VII) may be regarded as an oxidised form of thehypothetical intermediate in which both the sulphur and the oxygenatom are momentarily attached to a single nuclear carbon atom.A more detailed study of the rearrangement of phenacylbenzyl-dimethylammonium salts mentioned in the last Report has nowappeared.71 E’or the phenacyl group has been substituted p-bromo-+[Ph*CO-CH2*NMe2*CH2Ph]6H -+ Ph*CO*CH( CH,Ph)*NMe, + H,Ophenacyl and acetonyl, for the benzyl group various substitutedbenzyls, a-phenylethyl, benzhydryl, and 9-fluorenyl, and for thedimethylammonium radical piperidinium without alteration in thecharacter of the rearrangement. The change followed a unimole-cular course in alcoholic sodium ethoxide solution and no exchangeof radicals could be detected between the molecules of two differentcompounds undergoing rearrangement in a mixed solution. Therelative migration velocities of different substituted benzyl groupswere a8 follows :Substitutent ......p-M80 €I m-Br p-Br P-NO,Velocity .. ...... .... 0.77 1.0 1.6 2.52 about 30 -69 L. A. Warren and S. Smiles, J., 1930, 956; A . , 908.7O R.Henriques, Ber., 1894, 27, 3000; A., 1895, i, 103.7 1 T. S. Stevens, J., 1930, 2107; A . , 1437; T. S . Stevens, W. W. Snedden,E. T. Stiller, and T. Thornson, J., 1930, 2119; A., 1686; compare Ann,Reports, 1929, 26, 124ORCANIU CHEMISTRY.-PART II. 123The author's view of the course of the reaction may be representedthus :Ph*CO*CH,*$Me, EEe Ph*CO*8H*l!!Me2 I ---, I I -+CH2Ph (VIII.) CH2PhPh*CO*CH=NMe,0Ph-CO- H*NMe2 'i and -+-CH,Ph CH,Phthe free benzyl anion being captured again before it can escape intothe bulk of the reaction mixture. The facts could be equally wellexplained along the lines adopted for the cases discussed above.The rearrangement resembles the conversion by heat of isocyanidesinto nitriles :R-N=C- -+ -NEC-RA remarkable case of the migration of a group from a side chaininto the nucleus of an aromatic compound has been recorded.'2Met h y 1 and e t h y 1 1 : 4 - naph t haquinonepheny lhydrazone-N-carb -oxylates (IX), in the presence of cold alcoholic barium hydroxide,yielded, besides the products of hydrolysis, methyl and ethyl8-benzeneazo-5-hydroxy-l-naphthoates (X), a conversion thatinvolves the migration of the group C02R from the @-nitrogen atomin the side chain to the peri-position in the naphthalene nucleus.Phenyl ally1 aulphide is partly converted into o-allylthiophenolat temperatures above 200°,73 a rearrangement similar to that ofthe corresponding oxygen compound.74The difficulties 75 that frequently beset attempts to determinewhether a given rearrangement, dependent upon the presence of acatalyst, is or is not intramolecular are again exemplified in a studyof the rearrangement of the alkylanilines in the presence of metallic72 R.Willstatter, E. Ulbrich, L. PogBny, and C. Maimeri, Annalen, 1929,78 C . D. Hurd and H. Greengarcl, J. Amer. Chem. Soc., 1930, 62, 3356; A.,74 L. Claisen, Ber., 1912, 45, 3157; A,, 1912, i, 966.7 5 Ann. Reports, 1929, 26, 124.477, 161; A., 1930, 214.1285124 BENNETT AND CHAPMAN :salts.76 The authors conclude that the change is intramolecularand does not occur by successive fission and recombination of an--3 R -2alkyl halide, but the experimental results can be reconciled with theopposite view. The interesting observation was made that whereasisobutylaniline, heated with metallic halides, yielded p-aminoiso-butylbenzene, its hydrobromide, heated alone or in the presence of ametallic bromide, underwent rearrangement to p-amino-tert.-butyl-benzene.This was explained as due to a difference in the mechanismof rearrangement in the two cases, but a simpler explanation is thatthe hydrobromide evolved rapidly a large proportion of isobutylbromide, which isomerised to the tertiary halide in the vapour phasebefore recombination, whilst the liberation of halide from the mix-ture of base and salt was so much slower that nuclear substitutionoccurred before any considerable fraction of the halide had beenchanged.The stereochemical view of the isomerism of the chlorohydroxy-benzoyltoluic acids 77 has now been abandoned.78 The inter-convertible pairs are regarded as compounds of the type of (XI) and(XIII), and the rearrangement as proceeding through an inter-c1 c1 c1mediate compound (XII) of quinonoid structure. These conclusionsare supported by the facts that only one compound could be obtainedwhen phthalic anhydride was substituted for methylphthalicanhydride in the preparation, the two positions for the carboxylAgroup in (XIV) being equivalent, and that whilst two isomericcompounds, presumably (XV) and (XVI), were obtained by con-7 6 W.J. Hickinbottom and (in part) A. C. Waine, J . , 1930, 1558; W. J.7 7 M, Hayashi, J . , 1927, 2516; A., 1927, 1187; Ann. Reports, 1929, 26,7 8 Idem, J., 1930, 1613, 1520, 1524; A., 1183.Hickinbottom and G.H. Preston, ibid., p. 1566; A., 1174.141ORGANIC CHEMISTRY .-PART 11. 125densation of 4-methylphthalic anhydride with benzene, they werenot interconvertible, the essential substituent for the productionof quinonoid structure being absent.Free Radicals(compare Ann. Reports, 1924, 21, 115; 1928, 25, 150).An important event of the last two years has been the demonstra-tion of the real though transitory existence of the free methyl andethyl radicals.79 When the vapour of lead tetramethyl was passedat low pressure (1-5-2 mm.) through a heated tube, decompositionoccurred and lead was deposited. Passage of the gaseous productsof decomposition over a second lead mirror further along the tubecaused the disappearance of this mirror with the production of acompound that could be condensed, volatilised, and decomposedby passage through a hot tube togiveanother deposit of lead.Theactive material was also capable of attacking metallic zinc andantimony, producing in the former case a substance recognised aszinc methyl. The observed activity fell off rapidly as the distancealong the tube increased and disappeared when the material wascooled by means of liquid air. It was therefore concluded that thefree methyl radical had been formed by the decomposition of thelead alkyl, and the difliculty of its isolation was accounted for bythe very short, though measurable, life period, estimated at 0.006sec. for half disappearance under the conditions of the experiment.The preparation of the ethyl radical has since been announced.Itscompound with zinc has been isolated and found to be convertibleinto ethyl alcohol and to be free from lead.Whilst the free methyl and ethyl radicals represent an extremedivergence both in type and in stability from the well-knowntriarylmethyls, a number of tervalent carbon compounds have beendetected which differ to some extent from this class. Such arediphenyl-tert . - butylmet hyl80 and diphenylphenylethinylmethyl 81obtained on warming the corresponding ethanes and detected bythe reversible change of colour with change of temperature. Thelatter is a companion case to that of tetraphenylallyLa2A detailed study of another class of tervalent carbon compound79 F. Paneth and W.Hofeditz, Ber., 1929, 62, [B], 1335; A., 1929, 788;F. Paneth and W. Lautsch, Nature, 1930, 125, 564; A., 735. CompareG. Schultze and E. Muller, 2. physikal. Chem., 1930, [B], 6, 267; A., 302;F. Paneth, ibid., 7, 155; A , , 721.J. B. Conant and N. M. Bigelow, J . Amer. ClLem. SOC., 1928, 50, 2041;A . , 1928, 994.81 H. Wieland and H. Kloss, AnnuZen, 1929, 470, 201 ; A . , 1929, 1053.8a K. Ziegler, ibid., 1923, 434, 34; A., 1924, i, 308; Ann. Reports, 1928, 25,164126 BENNETT AND CHAPMAN :has been carried out by A. Lowenbein and his collaborators 83 on thecyano-, acyl, and lactone derivatives of tetraphenylethane (I to I11respectively).[CPh,(COPh)-1, (OGP) (1.1 (11.) \ 0 1 2[CPh,(~)-J,(111.)These compounds were all colourless and undissociated in the solidstate or in cold solution, but became deeply coloured on fusion orwhen heated in solvents.The dissociation constants were measuredby determination of the apparent molecular weights a t variousdilutions in boiling toluene or ethylene dibromide and the followingresults were obtained :Dissociation Dissociationconstant, const ant,in in in intoluene. C,H,Br,. toluene. C,H4Br,.0.0088 0.037 (jf:0*00066 0.0043Q&C 0 0dissociationcommenceda t 140"0.0011 - ph27- co CN0(Me0.C,H4)2. j! - dissociationcommencedCN at 60-80"Reassociation with corresponding loss of colour occurred when thesolutions were cooled. Similar dissociation has been qualitativelyobserved in the case of benzpinacol dibenzoate in molten naphthal-ene.84 The 2 : 3 : 4-trisubstituted dichromenyls 85 also dissociate8.9 A.Ltswenbein and H. Simonis (with H. Lang and W. Jacobus), Ber., 1924,57, [B], 2040; A., 1926, i, 147; A. Lawenbein (with W. Folberth), Ber., 1926,58, [B], 601; A., 1926, i, 662; A. Lowenbein and R. F. Gagarin, ibid., p.2646; A., 1926, 168; A. LSwenbein and H. Schmidt, Ber., 1927, 60, [B],1861; A., 1927, 1072; A. Lijwenbein and L. Schuster, Annalen, 1930, 481,106; A , , 1184.** F. F. Blicke, J. Amer. Chern. SOC., 1926, 47, 1477; A., 1925, i, 811.86 A. Lowenbein and B. Roaenbaum, Annalen, 1926, 448, 223; A., 1926,955ORGANIC CHEMISTRY .-PART 11. 127on solution or fusion, but this case is complicated by the possibilityof the free valency occurring on either the 2- or the 4-carbon atom.I R \(R = Ph, a-naphthyl, benzyl.)The possibility of free radicals being formed as intermediateproducts in the course of chemical reactions, whilst always admissible,is only occasionally supported by the experimental evidence.Investigations by Wieland and his collaborators 86 of the thermaldecomposition of various azo-compounds, however, illustrate thispossibility and show that some less well-known types of free radicalsare capable of at least momentary existence.When azo-compoundsof the type ArN:N*CPh, were heated in inert solvents, nitrogen wasrapidly eliminated and trip henylmethyl was recognised among theproducts. The aryl radical underwent reduction to the correspond-ing hydrocarbon. Certain aryl compounds R*CO-N:N*CPh, alsogave off nitrogen when heated and formed deeply coloured solutions.The colour faded even in t'he absence of air and the ketoneR*CO*CPh, was obtained from the resulting solution.In thepresence of oxygen, however, triphenylmethyl peroxide was formedtogether, in some cases, with the corresponding acyl peroxide.Evidently the decomposition resulted in the temporary formationof the two free radicals.R*CO*N,*CPh, + RCO- + --CPh, + N2 -+ R*CO*CPh, - (RCOO-), + (CPh,*O),Determinations of the velocity of dissociation of hexaphenyl-ethane 87 and of various dialkylxanthyls 88 have been made, iodineand oxygen respectively being used to combine with the free radicalsas formed. The conclusion of M. Gomberg and F. W. Sullivan 89that the colour and degree of dissociation of free radicals in solutionare not simply related has been criticised for theoretical reasons andon the ground of insufficient accuracy of the experimental evidence.g086 H.Wieland, E. Popper, and H. Seefried, Ber., 1922, 55, [B], 1816; A.,1922, i, 772 ; H. Wieland, H. vom Hove, and K. Borner, Annalen, 1926, 446,31; A., 1926, 61; H. Wieland, A. Hintermaier, and I. Dennstedt (with J.Lorenzo), Annalen, 1927, 452, 1 ; A., 1927, 237.K. Ziegler, L. Eweld, and P. Orth, Annalen, 1930, 479, 277; A., 711.8 8 J. B. Conant and M. W. Evans, J . Arner. Chern. SOC., 1929,51,1926; A.,1929, 934.Ibid., 1922, 44, 1810; A., 1922, i, 929.C. B. Wooster, ibid., 1929, 51, 1163; A., 1929, 648128 BENNETT AND CHAPMAN :A further set of optical measurements 91 on solutions of hexaphenyl-ethane, tetraphenyldi- -naphthylethane, and bis-2 : 3 : 4-triphenyl-6-methylchromenyl in various solvents has shown that, if theratio E,/E, of the extinction coefficients at dilution v and a t infinitedilution be taken as a measure of the degree of dissociation of thediradical, Ostwald’s dilution law is obeyed.The heat of dissociationof hexaphenylethane calculated from the temperature coefficientof dissociation was found to be about 11.5 kg.-cals. per mol. and tobe practically independent of the solvent in which dissociation tookplace. The kinetics of the oxidation of hexaphenylethane by freeoxygen have also been in~estigated.~2In the Annual Report for 1928 it was suggested 93 that the degreeof dissociation of substituted hexa-arylethanes was determinedlargely by the effects of substitution on the stability of the anionAr,C and that these effects were not necessarily the converse ofthose of similar substitution in the kationic radical.The dissoci-ation constants of a number of para-substituted triphenylmethylchlorides have recently been determinedg4 and follow the orderC6H4*OMe,C6H4*NO,,Ph > Ph, > C6H4*OMe, (C6H4*N02)2 >C6H4*N0,,Ph2> (C,H,-NO,),,Ph, which should be, and is, that ofkationic stability. The dissociation of the corresponding hexa-phenylethanes could not be studied quantitatively owing to theinstability of the compounds, but qualitative observations sufficedto show that the order of radical dissociation was not parallel withthe determined order of kationic stability.It is not, however, soeasy to reconcile the comparative stability of the undissociateddiacyltetraphenylethanes 83 with this suggestion, as the presenceof the acyl group should tend to stabilise the anionic radical and sopromote dissociation.On the other hand the stability of free hydrazyl radicals, as waspointed out in the same Report,93 is not determined by the stabilityof the anionic form, but is favoured by the simultaneous presence ofgroups capable of attracting and repelling electrons. A series of1 : 1 : 4 : 4-tetra-aryl-2 : 3-dibenzoyltetrazanes studied by S. Gold-Schmidt and J. Bader 95 illustrates still more clearly the validity ofthis generalisation.91 K.Zieglsr and L. Ewald, Annalen, 1929, 473, 163; A., 1929, 1010.92 R. C. Mithoff and G. E. K. Branch, J. Amer. Chent. SOC., 1930, 52, 255;Ann. Reports, 1928, 25, 154; compare also H. Burton and C. K. Ingold,A., 301.Proc. Leeds Phil. SOC., 1929, 1, 421 ; A., 1929, 1052.a4 K. Ziegler and W. Mathes, Annalen, 1930, 479, 111 ; A., 762.@j Ibid., 1929, 473, 137; A., 1929, 1173ORGANIC CHEMISTRY .-PART 11. 129In these compounds a constant electron-restraining influence ofconsiderable magnitude is provided by the benzoyl group on theP-nitrogen atom. The dissociation should therefore be favouredin proportion as the groups R and R1 have electron-releasing capaci-ties of either inductive or tautomeric kind. This is borne out bythe order of the dissociation constants of these compounds, whichwas found to be (for R and R1), di-p-nitrophenyl<phenyl, p-nitro-phenyl< di-p- bromophenyl < phenyl, p - bromophenyl <diphenyl <p henyl, p - tolyl < di-p- tolyl < phenyl, p - anisyl < di-p - anisyl.The lastcompound was completely dissociated in acetone solution.isocyanides and Related Compounds.An important addition to the knowledge of this class of compoundshas been made by D. L. Hammick, R. C. A. New, N. V. Sidgwick, andL. E. Sutton,96 who have obtained conclusive evidence in favour ofthe formula (I) for the isocyanides in place of the bivalent carbonstructure (11) by measurement of the parachors and dipole momentaof a number of isonitriles.(I). R-NZC R-N=C (11).The calculated parachor of the group -NfC is 62.3, whilst themost probable value for -N=C is 40.5.Examination of p-tolyl,p-anisyl, and ethyl isocyanides gave values of 66, 66, and 69respectively for the -NC group.The dipole moment of the group -NC was found from measure-ments with p-tolyl and p-chlorophenyl isocyanides to be 3.6 (E.S.U.x 10-l8), the carbon being tho negative pole. The Nef formula (11)is untenable, since it leads to a value of 2 in the opposite direction,but the experimental result is in good agreement with a computedvalue for -NSC. The structure thus established is in agreementwith the chemical properties of the isonitriles and reveals theidentity of the ions (111) derived from both tautomeric forms ofhydrogen cyanide. Similar structures can be ascribed to carbon(111.) [-N--C-]- [-c-o-] (IV.)monoxide (IV)97 and presumably to compounds such as carbonmonoxide diethyla~etal.~~9 6 J., 1930, 1876; A., 1239.g7 S.Sugden, " The Parachor and Valency," 1930, 171.g * H. Scheibler, Ber., 1926, 59, [ B ] , 1022; 1927, 60, [B], 554; A., 1926,711; 1927, 338; H. Scheibler and E. Baumann, Ber., 1929, 62, [ B ] , 2057;A., 1929, 1296.REP .-VOL . XXVII . 130 BENNETT AND CHAPMAN :Aromtic Substitution(continued from Ann. Reports, 1928, 25, 137).The two years now under review have seen the publication ofmuch systematic work on the substitution of aromatic compounds,particularly in the diphenyl and other polynuclear series. Severalother investigations are worthy of special note, including thosedealing with the nitration of phenylboric acid ; the directive influenceof the nitroso-group; and the manner in which stereochemicalfactors may control the direction of substitution.General Theory.-A new orientation rule has been proposed whichis at the same time simple and based on the fundamental classi-fication of the elements.99 It states that, if in a benzene derivativePh-X-Y, Y is in a higher group of the periodic table than X, or if,being in the same group, Y is of lower atomic weight than X, thegroup XY is meta-directive, whilst in other cases [including thosein which (a) X = Y and ( b ) Y is absent] the direction is of theortho-para type.It must also be borne in mind that ionic chargeson XY of positive or negative sign will cause meta- or ortho-para-direction respectively.Nitrosobenzene seemed to be the only exception to this rule, asbromination of the substance takes place in the para-position incarbon disulphide at - 5O.1 However, experiment shows that thenitroso-compound is considerably associated under these conditions,and that in acetic acid, in which it is not associated and with whichit does not combine, reaction is very slow and no para-substitutioncan be detected.That the nitroso-group belongs to the meta-directive category is, moreover, clear from the observation that o-and p-bromonitrosobenzenes react with silver nitrate in glacialacetic acid to yield silver bromide, whereas the m-isomeride isunaffected.A calculation of the net charge on the substituent atom of variousgroups, assuming the electrons to be shared in the ratio of thenuclear charges of the atoms they unite,2 places the various substi-tuents approximately in the order of their directing powers.Thereare, however, some marked divergences, such as the position of thefree poles NH, and NR,, which should be found at the extreme ofm-directing groups.The angle between the plane of a double bond and the adjacentsingle bonds is according to the tetrahedral theory of the order 125".9s D. L. Hammick and W. S. Illingworth, J . , 1930, 2358; A., 1666.@ c3C. K. Ingold, J., 1925, 513; A., 1925, i, 646.W. M. Latimer and C. W. Porter, J . Amer. Chem. SOC., 1930, 52, 206; A.,331ORGANIC CHEMISTRY .-PART II. 131The external valencies of a benzene nucleus of the Kekul6 formulashould therefore not be directed as from the centre of the hexagon,but should diverge at both sides of each double bond so that theexternal angle p exceeds the adjacent angle cc by an amount whichowing to the closure of the ring w i l l be even more than in open-chainolefins (I).3 Consequently it may be concluded that of the tKopossible forms of hydrindene (11) and (111), (111) should be the lessstrained and should constitute the major constituent of the equili-brium mixture of forms.In confirmation of this it is found that 5-hydroxyhydrindene issubstituted by bromine and by diazonium salts in position 6 ratherthan 4 : for the analogy between phenols and enols in such reactionsmakes it reasonable to expect that substitution occurs at the carbonatom joined to the C*OH by means of a double bond, so that theattack on the two possible forms of 5-hydroxyhydrindene (IV and3 W.H. Mills and I. G. Nixon, J., 1930, 2610132 BENNETT AND CHAPMAN :V) would be as indicated by the arrows : structure (V) is thereforeJ. .L CH,~0//4\/2, (+(,/ H O P 0 +v Ho?y):2 \A(vr.) CH, (IV.) (V.1indicated for the hydroxyhydrindene and (111) for the parenthydrocarbon. In the same way 5-acetamidohydrindene is bromin-ated in position 6.5On the other hand, ar-tetrahydro-@-naphthol is known to beattacked as shown in (VI) and the corresponding acetamidotetra-hydronaphthalene reacts in the same ( a - ) position.6 Of the twopossible structures, formula (VI) consequently represents thearrangement of bonds in the tetrahydronaphthalene nucleus.It isshown by a careful consideration of both the angles and the inter-atomic distances (different for the aromatic and the alicyclic atoms)that the saturated part of the system would most probably attain agreater freedom from strain by departure from the single plane inthis structure (VI) than would be the case for the alternative formin which the common bond between the two rings is a single one.These arguments reveal important factors which must not be lostsight of in the orientation problem, and they also constitute a remark-able tribute to the value of KekulB's formula for benzene.The importance of nitrous acid in certain nitrations has recentlybeen emphasised.' As a result of a detailed study of the nitrosationand nitration of phenols, S.Veibe18 considers that the nitrophenolsresult from the oxidation by nitric acid of intermediate addition-compounds of phenol and nitrous acid, which are also the precursorsof o- and p-nitrosophenols. Reaction velocity data and the o / pratios in nitration and nitrosation are accounted for if the postulatedaddition compounds are equally readily oxidised but the dehydrationto p-nitrosophenol is faster than that to the o-isomeride.The directive effects of a series of groups have been determinedin recent years by F. Challenger and his associates. The resultsof the nitration of a number of aromatic thiocyanates and seleno-W. Borsche and A. Bodenstein, Ber., 1926,59, [B], 1910; A., 1926, 1133.G.Shroeter, Annalen, 1922, 426, 83; C. Smith, J., 1904, 85, 730; A.,1922, i, 126.7 L. A. Pinck, J. Arner. Chem. SOC., 1927, 49, 2536; 3'. H. Cohen, Proc. K.Akad. Wetensch. Amsterdam, 1928, 31, 692; M. Battegay, Bull. SOC. chim.,1928, [iv], 423, 109; H. H. Hodgson and A. Kershaw, J., 1930, 277; A., 1927,1177 ; 1928, 272,402 ; 1930,466.a Ber., 1930,63, [B], 1577, 2074; 2. physikal. Chem., 1930, [B), 10, 22; A.,1033, 1429, 1673.4 Compare the coupling of diazonium salts with jl-naphtholORGANIC CHEMISTRY .-PART 11. 133cyanatesg show that the SCN and SeCN groups have far greaterop-directive powers than the halogens but less than the NHAcgroup. An interesting point in connexion with the nitration ofo- and p-tolyl thiocyanates is discussed below (see o/p Ratio, p.138).Another result of importance is the production of 72% of them-substitution product in the nitration of phenylboric acid,Yh-B(OH),,10 at - 20". The boron atom has in this compound onlysix electrons in the outer shell. Conjugation with the nucleus(+T effect) is impossible and the tendency is conversely to attractelectrons from the nucleus in order to complete the octet. Con-sequently m-direction prevails. Tribenzylphosphine oxide anddibenzylphosphinic acid are nitrated almost entirely in the p-position.A study of the nitration of a long series of alkyl benzoates gavethe following proportions of m-nitration product : 11AZkyZ ...... Methyl Ethyl Propyl Butyl Amy1 Hexyl Heptyl OctyiAZkyE ......Cetyl Chloromethyl /3-Chloroethyl y-Chloropropy]AZkyZ ...... 6-Bromoethyl y-Bromopropyl woButyl sec.-Butylyo m ......... 71.5 72.8 69-4 65.2y0m ......... 72.6 69.9 71.8 67.9 68.3 63.7 62-8 60.2y0m ......... ca. 52 81.9 75.8 77.3AlkyZ ...... isoPropyl 8ec.-Octyl te.rt.-Butylyo m......... 64-1 59.4 59.4The progressive depression of the m-directing power of the estergroup as the normal carbon chain increases is clearly seen, but thereis a definite alternation in the first three and possibly the first fiveof the series. The effects of branched chains and halogen substitu-tion are fully in accord with the known inductive effects.The surprising tendency for certain alkyl groups to enter them-position in toluene during its condensation with alkyl halidesin presence of aluminium chloride has been confirmed by J.B.Shoesmith and J. F. McGechen.12 From tert.-butyl chloride inpresence of either aluminium or ferric chloride, tert. -butyltolueneresulted in the ratio m : p = 65-70 : 35-30. With n-butylchloride the sec.-butyltoluenss were obtained, m : p = 75 : 25.Positive Poles.-The m-orienting influence of oxonium oxygen andquinolinium nitrogen has been observed by R. J. W. Le FBvre 13S F. Challenger and A. D. Collins, J., 1924, 125, 1377; F. Challenger andA. T. Peters, J., 1928, 1364; F. Challenger, (Miss) C. Higginbottom, and A.Huntingdon, J., 1930,26; A., 1924, i, 953; 1928, 750; 1930, 332; compareAnn. Reporb, 1924, 21, 110.10 A. D. Ainley and F. Challenger, J., 1930, 2171 ; A., 1457.11 A.Zaki, J., 1928, 983; 1930, 2269; A., 1928, 636; 1930, 1578.12 J., 1930, 2231.13 J . , 1929, 2771; R. J. W. Le Fhre and F. C. Mathur, J., 1930,2236; A.,271, 1696134 BENNETT AND CHAPMAN :with the 2-phenylbenzopyrylium and 2-phenylquinolinium salts (I)and (11), nitration of which attacks exclusively the positions indic-ated. No isomerides were detected and the yields were 86% and1 0 0 ~ o respectively. 2-Phenylquinoline itself gave 66 yo of thecorresponding nitro-compound.x r”? i5 NMelXThe effects of the sulphonium and selenonium groups in aromaticsubstitution have been determined. A. Pollard and R. Robinson 14find that benzyldiethylsulphonium picrate yields on nitration 28 yoof the m- and about 61% of the p-isomeride.These figures shouldbe compared with those for benzyltriethylammonium picrate(85% m) l5 and benzyldiethylamine sulphate (4&-52y0 m ; l661 yo m).17 A direct comparison of phenyl and benzyl sulphoniumand selenonium salts in nitration has been made by J. W. Baker andW. G. Moffitt,lg the percentages of m-products being :Ph-iMe, . . 100 Ph*CH,.iMe, . . 52Ph-ieMe, . . 100 Ph*CH,*SeMe, . . 16These and previous results all show that for similar compounds theproportion of meta-substitution (a) decreases with increasing atomicnumber of the directing atoms in a single group of the periodicsystem, ( b ) increases with increasing atomic number in any oneperiod. Thus for m-directive power we have the series N<O andg>ie, whereas for op-direction we have N>O>F.19The fact that a basic group loses its predominant position in thecontrol of substitution when it is converted into a salt, as a resultof the relative slowness of the reaction in presence of the positivepole, is illustrated by several recently recorded instances.Thusnitration of o- and m-bromoanilines in concentrated sulphuric acid *O1 4 J . , 1930, 1765; A . , 1302.15 13’. R. GOSS, C. K. Ingold, and I. S. Wilson, J., 1026, 2440; &4., 1926,l6 B. Fliirscheim and E. L. Holmes, ibid., p. 1562; A., 1926, 830.17 Baker and Ingold, Ref. 27 (p. 136).la J . , 1930, 1722; A., 1302.2o R. Luke; and J. Fragner, J. Czech. Chem. Comrn., 1929,1, 294; A., 1929,4-+ +1133.Ann. Reporte, 1926, 23, 138.804ORGANIC CHEMISTRY.-PART II.135takes place in positions 5 and 4 respectively, as shown in (111) and(IV), the bromine atom having the greater influence. Further(111.) ?Tso4observations of the nitration of phenylbenzylamine derivatives 21are fully in accord with modern views. When phenylbenzyl-n-butylamine and phenyldibenzylamine are nitrated in sulphuricacid, the isolated products (c. 50% and 21% respectively) &rephenyl-m-nitrobenzyl-n-butylaniline and phenyldi-m-nitrobemyl-amine. On the other hand, phenyldibenzylamine nitrated in aceticacid, and phenylbenzylnitrosoamine with ordinary nitric acid, aresubstituted according to the op law in the phenyl nucleus as wouldbe expected.22+Acids and t,h-Bcc;ses.-It has been pointed out 23 that the anionof a +acid such as phenylnitromethane, in which the negativecharge may be regarded as distributing itself between the possiblePh*CR:NO*O.tautomeric positions, should undergo op-substitution :J.W. Baker has made a study of the nitration of such +acids undervarious c0nditions.~4 There was considerable meta-substitutionin all cases, but the results fully bear out the author’s view, thealkali salts showing a much lower proportion of m-direction, unlessnitric acid of density 1.529 was used. Thus the free phenylnitro-methane yielded 67% m- + 33% op-, but the potassium salt (withnitric acid of density 1.497) gave 42% m- + 58% op. The contrastwas even more striking in t)he case of ethyl a-nitrophenylacetate,NO,*CHPh*CO,Et. These results emphasise the large differenceswhich may arise from small differences in the composition of thenitrating acid, a point shown even more clearly in another paperfrom the same source describing the nitration of phenylbromo-~yanonitromethane,~~ where a similar variation in the concentrationof the nitric acid raised tho proportion of m-products from 32%0 -to 94%.21 J.Reilly, P. J. D r u m , and T. V. Creedon, J., 1929, 641 ; Sci. Proc. Roy.Compare Ann. Reports,p2 R. D. Desai, J . Indian Chern. SOC., 1928, 5, 425; A., 1928, 1237.25 Ann. Reports, 1927, 24, 115; 1928, 25, 140.24 J., 1929, 2257; A., 1929, 1447; compare B. Fliirscheim and E. L.26 J. W. Baker and C. K. Ingold, J., 1929, 423; A., 1929, 546. See alsoDublin SOC., 1930,19, 377 ; A., 1029, 691 ; 1930, 904.1928, 25, 138.Holmes, J., 1928, 453 ; A., 1928, 403.Ann. Reporta, 1929, 26, 124136 BENNETT AND CHAPMAN :Just as +acids with phenyl attached to the $-atom show op-direc-tion, so $-bases tend to direct m.B. Flurscheim and E. L. Holmes z6obtained 87.5% of m-nitro-derivative from benzylidene-m-nitro-aniline, C,H,*CH:N*C,H,-NO,, by nitration in concentrated sulphuricacid. They held that this represented a nitration of the free base,and the result was important, for Fliirscheim’s theory requires thatPh*CH:NR shall show higher m-direction than Ph*CH:O (81% m-),whereas the electronic theory leads to the opposite prediction for@ nitration of the free base. Clear evidence }g has been produced, however, by J. W. Baker mcH’NH*Ar and C.K. Ingold27 that the Schiff’s base ispresent in the sulphuric acid as a salt (V),(V-1 which was actually isolated. The proportionof m-nitro-derivative was moreover reduced by addition of arnmon-ium sulphate from 89% to 84%, the magnitude of which effect isin accordance with expectation, since the salt of which the dis-sociation is being depressed is it $-salt with a neutral form intowhich it can pass. The situation is therefore reversed and thequestion may be regarded as decided in favour of the electronictheory.An observation of considerable interest both from a theoreticaland a practical point of view is that the p-toluenesulphonamido-group has a markedly stronger op-directing power than the acet-amido-group.28 For example, 2-p-toluenesulphonamidodiphenyl isreadily nitrated first in the 5- and then in the 3-positionY yielding(I) and (11), whereas 2-acetamidodiphenyl is nitrated in position 4’to give (III).29O2N 0,N7 1 -NH*S0,*C7H7 NHAc(1.1 (11.) (111.)The corresponding methylated acyl derivative, 2-p-toluenesulphon-methylamidodiphenyl, is nitrated with much greater difficulty a tposition 5 .Bearing in mind the solubilityof the unmethylated sulphonamido-compoundin alkali, it appears that the nitrogen atoma partial negative charge on it, the systempressed by methylation.in it has a special directive power owing to- being a +acidic one. This is of course sup-2 6 J . , 1928, 2230; A . , 1928, 1126. 27 J . , 1930, 431 ; A . , 594.28 F. Bell, J., 1928, 2770; 1929, 2784, 2787; A ., 1928, 1367; 1929, 204.29 H. A. Scarborough and W. A. Waters, J., 1927, 89; A., 1927, 236ORGANIC CHEMISTRY.-PART 11. 137The Ortho-Puru Rutio.--In an interesting discussion of theinfluences which determine the ratio of the ortho- and para-directedproducts in aromatic substitution, A. Lapworth and R. Robinsonconclude that, as a result of the presence in the benzene nucleus of agroup A having a smaller attraction for electrons than has thehydrogen atom, electron-availability and therefore reactivity shouldtend to be greater in the 0- than in the p-position :0With a substituent B which attracts electrons, the potential gradientin the molecular field will be reversed and consequently reactionshould occur pf>o’. This leads to the expectation of a high o/pratio for groups such as Me but a low one for m-directive groupssuch as NR,, NO, and CO,H, and also for op-directive groups havinga natural electron attraction such as C1, OMe.The considerable o-orientation caused by NO,, CHO, and CO*CH,is regarded as an anomaly due to the attraction of the reagent tosuch groups, which are actually known to exert basic function^.^^The tendency of the nitro-group to enter 0- to a m-directive grouphas been emphasised by J.Obermiller,32 who terms this phenomenon“ auto-orientation.” In this respect there is a sharp contrast betweenthe positions of entry of the NO, and SO,H groups (possibly owingto the greater acidic strength of nitric acid as compared with sul-phuric acid).An appreciable proportion of o-product is formedin the nitration of nitrobenzene, benzenesulphonic acid, and benzoicacid, but none in the corresponding sulphonations, and the dis-similar products of nitration and sulphonation of metanilic acid alsoshow this effect :+30 Mern. Mancheeter Phil. SOC., 1927, 72, 43; A., 546; compare Ann.Reports, 1926, 23, 140.31 It should be noted t o avoid confusion that this view involves a reversalof the explanation given by J. Allan, A. E. Oxford, R. Robinson, and J. C.Smith (J., 1926, 409; A., 1926, 397) where these o-substitutions were takento be normal and the influence of the electrical field was stated in the oppositesense.32 J . pr. Chem., 1914, [ii], 89, 70; 1930,126, 257; A., 1914, i, 513; 1930,1028.E138 BENNETT AND CHAPMAN :The former authors 30 emphasise the large influence which con-ditions of reaction may have on the o/p ratio, and a further dis-turbing factor which may operate is the steric inhibition of o-sub-stitution, nitration of the higher alkylbenzenes being a possiblecase in point.Apart from these difficulties this view of the o/p ratio 33 gives asatisfactory explanation of a large number of facts.Some newcases of this kind will now be referred to.The contrast between the orientations of the principal productsof nitration of o- and p-tolyl thiocyanates (I) and (11) (comparep. 133), suggesting at first sight that Me has a greater directive powerthan SCN in one case and a smaller in the other, is clearly a naturalconsequence of the opposite o / p ratios which the two groups possess(nitration of toluene, o : p = 56 : 41 ; of phenyl thiocyanate, o : p =20 : 80).SCN SCNA study of the nitration of cyclohexylbenzene and its p-halogeno-derivatives by H.A. Mayes and E. E. Turner 34 is of interest fromthe same point of view. The percentages of mononitro-isomeridesobtained are indicated by the figures in the following formuls, datafor toluene compounds being added for comparison :The cyclohexyl group has thus a lower o/p ratio than methyl inagreement with the behaviour of the higher alkyl groups. Thefigure of the ratio p/*o is 3.3, which may be compared with thosefor chlorine (4.6) and bromine (3.3). The explanation of theresult for p-bromocyclohexylbenzene may lie in a higher level ofpromotion of reactivity due to alkyl as compared with that due tobromine.s3 The interpretation given by C.K. Ingold (Rec. trav. chim., 1929, 48,807 ; A., 1929, 1289 ; Ann. Reports, 1926, 23, 140) more closely resembles thescheme of J. Allan, A. E. Oxford, R. Robinson, and J. C. Smith, Eoc. cit.34 J., 1929, 500; A., 1929, 550, and for comparative data A. F. Hollemanand J. P. Wibaut, Proc. K. Akad. Wetensch. Amsterdam, 1912, 15, 694; L.Gindraux, HeEv. Chim. Acta, 1929, 12, 921 ; A., 1913, i, 169; 1929, 1433ORGANIC CHEMISTRY .-PART 11. 139The ratios of o/p-hydroxy-aldehydes formed in the Reimer-Tiemann reaction from a series of phenols C6H4X*OH have beenfound to be as follows : 35X .................. H o-Me m-Me o-C1 o-Br 0-1O/P ..................0.6 0.48 0.46 1.6 1.25 1.0701p .................. 0.87 0.71 0.72 0.78 0.06X .................. m-3’ m-C1 m-Br m-I o-CO~HThe figures for m-C1, Br, I may be regarded as identical, but they arehigher than that for phenol and lower than that for m-fluorophenol.These facts are consistent with the directing power of the halogens,which in general promote substitution para with respect to theirown position and particularly so in the case of fluorine. Thehigh o/p value found for o-halogenophenols appears to constituteanother instance of the tendency for substituents to enter thenucleus in the ortho-position to a strongly op-directive group whena second (weaker) op-directive atom is next to it (in the 0’-position),and the relative effect of the halogens (Cl>Br>I) in the presentcase is in accordance with expectation.36Orientation in Diphenyl Compounds.-Although pp’-dibromo-diphenyl had been shown to yield on nitration the o-nitro-compound(I),37 pp’-difluorodiphenyl was stated 38 to be substituted in them-position to give (11).R.J. W. Le E’Bvre and E. E. Turner find 39 that the latter productdoes not react with piperidine and must be, not (11), but the fluorineanalogue of (I). A second nitro-group enters to give an unsym-metrical product (111), as in the case of the dibromo- and dichloro-diphenyls : one fluorine atom in (111) is removed by piperidine.Diphenyl and its mono- and di-nitro-derivatives are nitrated inthe o- and p-positions to the extent shown by the figures attached : 4oH.H. Hodgson and J. A. Jenkinson, J., 1929,469,1639; H. H. Hodgsonand J. Nixon, J., 1929, 1632; A., 1929, 669, 1177.s6 Ann. Reports, 1926, 23, 138; E. L. Holmes, C. K. Ingold, and (Mrs.)E. H. Ingold, J., 1926, 1684; A,, 1926, 947.57 Ann. Reports, 1926, 23, 137.38 G. Schiemann and W. Roselius, Ber., 1929, 62, [B], 1805; A., 1929, 1052.as J., 1930, 1168; A., 901.40 H. C. Gull and E. E. Turner, J., 1929, 491; A., 1929, 647; compareF. Bell, J. Kenyon, and P. H. Robinson, J., 1926, 1239, 2706; A., 1926, 830,1241 ; W. Blakey and H. A. Scarborough, J., 1927, 3000; A,, 1928, 166140 BENNETT AND CHAPMAN :68The o/p ratio is approximately the same in the nitrodiphenyls andis definitely lower than that for diphenyl itself, as it should be.Further nitration gives the 2 : 4 : 4’-trinitro- and the 2 : 4 : 2’ : 4’-tetranitro-compound.The study of the chemistry of halogeno-, hydroxy-, and amino-diphenyls and their acyl derivatives has engaged the attention ofa number of workers, and the resulting orientation data are for themost part normal.Two general conclusions of importance are :that the phenyl or substituted phenyl nucleus exerts a strongop-directive effect; and that there is no evidence of conjugationbetween the nuclei, their behaviour being independent so far asconjugative (tautomeric) effects are ~oncerned.~l This is in con-trast with the behaviour of the phenylpyridine~.~~The sequence of directing powers OH> OMe> O*SO,*C,H, isclearly indicated in the results obtained by F.Bell and J. Kenyon 43in which it is found that 4-hydroxydiphenyl is substituted first inposition 3, the methoxy-compound in positions 3 and 4‘, and theacyloxy-compound in position 4’ :There are frequent examples of the well-known tendency forsubstitution to take place in the second nucleus when a deactivatinggroup is present in the first.44 Two anomalous cases of substitutionwere reported,45 namely, the entry of bromine into the 4’-positionin 4-acetamidodiphenyl and of the nitro-group into the 4’-positionin 2-acetamidodiphenyl (yield 50%). However, J. Kenyon and41 H. A. Scarborough and W. A. Waters, J., 1926, 557; R. J. W. Le FBvre42 Ann. Reports, 1926, 23, 136.43 J., 1927, 3044; A., 1928, 145.44 Compare Ann.Reports, 1926, 23, 134; 1928, 25, 138.4 5 H. A. Scarborough and W. A. Waters, J., 1926, 5 6 e 1927, 89, 1133;A . , 1926, 612; 1927, 236, 666.and E. E. Turner, J., 1928, 245, 963; A., 1926, 512; 1928, 283, G30ORGANIC CHEMISTRY.-PART 11. 141P. H. Robinson 46 have found that chlorine substitutes the 4-acet-amido-compound exclusively in position 3- to give (I) and thereaction with bromine yields the analogous product (I) to the extentof 50% with only 30% of (11). The nitration referred to is notsurprising, as the sulphurio acid which was present must tend toconvert the acetamido-group into a deactivating rather than anactivating agent .47Other PoZynuclear Types.-The examination of a number of casesof substitution of benzophenones has given straightforward results,48but an interesting problem is presented by the proportions of mono-nitration products, as shown by the figures attached to the annexedformuke, of pp’-chlorobromo-benzophenone and -diphenylsulph-one : 49Nitration of diphenyl ether has given 24% and 44% of 0- andp-nitro-compounds respectively : but in presence of acetic anhydride46% 0- and 54% p - have beenpp’-Dichlorodiphenyl ether is nitrated in the 00’-positions(exclusive direction by the oxygen atom), but on the other hand aseries of compounds of the type (I), in which A is either an acyl or anitrated phenyl radical, are nitrated in position 5 as shown, thedirective power of the oxygen atom being no doubt reduced by thegroup A.514 6 J., 1926, 1242, 3050; A., 1926, 830; 1027, 142.4 7 Compare the nitration of aceto-p-toluidide and that of aceto-sn-4-xylidide ;See also Ref.2848 W. Blakey, W. I. Jones, and H. A. Scarborough, J . , 1927, 2865; W.Blakey and H. A. Scarborough, J., 1928, 2489; W. A. Waters, J., 1020,2106; L. Chardonnens, Helv. Chim. Acta, 1929,12, 649; J . van Alphen, Rec.trav. chim., 1930, 49, 153, 383; A . , 1928, 66, 1246; 1929, 928, 1299; 1030,476, 603.H. E. Dadswell and J. Kenner, J . , 1927,1102; A., 1927,656.(p. 136).49 L. G. Groves and E. E. Tumor, J . , 1929, 509; A., 1929, 561.50 C. M. Suter, J . Arner. Chem. Soc., 1929, 51, 2581; G. Lock, Monatsh.,1930,55, 167; A., 1929, 1174; 1930, 767.5 1 R. J. W. Le Fhvre, S. L. M. Saunders, and E. E. Turner, J ., 1927,1168; L. G. Groves, E. E. Turner, and G. I. Sharp, J., 1929, 512; A , , 1927,660; 1929, 551142 BENNETT AND CHAPMAN :A tendency for substitution in one nucleus of a diphenyl etherto stop when one out of two available o-positions in a single nucleushas become occupied has been noticed 52 in certain brominations.A0 Br(JA 0-0-0 NHA~~if NHAcc1(1.1 (11.) (111.)Bromination of o- and p-acetamidodiphenyl ethers also givesproducts (11) and (111) in which substitution does not occur o- tothe acetamido-group. The acetamido-group, it should be remem-bered, has a low o/p ratio.Several other studies of diphenyl ethers have been published.%Some of the earlier work on the nitration of azobenzene wasfaulty. Nitration or bromination of this substance occurs inpositions 4 and 4', and this result is unaltered by the presence a tposition 2, 3, or 4 of either Me or C1.The group C,H,*N:N- is thusmore strongly directive than either chlorine or methyl. On theother hand, methoxyl, amino-, and acetamido-groups supersede theazo-group in controlling substitution in such molecules.54Heterocyclic Compounds.-The nitration of the three isomericbenzylpyridines is of interest in comparison with that of the phenyl-pyridines 55 previously reported. The amounts of 2-, 3-, and 4-m-nitrobenzylpyridines found are 10.4y0, trace, and 4.8% respectively.There is thus a reduction of m-direction (corresponding amounts ofthe m-nitrophenylpyridines : 2-, 34.9% ; 3-, trace; 4-, 286%), aswould be expected from the presence of an extra carbon atombetween the pole and the seat of reaction.There is nevertheless areal direction to the m-position.The nitro-group entered chiefly the pposition of 2-phenyl-l-methylglyoxaline, 1 - and 2-phenylglyoxalines, and 4-phenyl-piperidine. The m-nitro-compound predominated, however, when4-hydroxy-2-phenyl-6-methylpyrimidine 56 was nitrated.52 H. A. Scarborough, J., 1929, 2361 ; H. McCombie, W. G. Macmillan, andH. A. Scarborough, J., 1930, 1202; A . , 1929, 1439; 1930, 1034.63 (Miss) R. V. Henley and E. E. Turner, J., 1930, 928; (Miss) D. L. Foxand E. E. Turner, ibid., pp. 1115, 1853; L. C. Raiford and I. J. Wernert,J. Amer. Chem. SOL, 1930,52, 1205; A., 907, 909, 1283, 767.64 J. Burns, H. McCombie, and H.A. Scarborough, J., 1928, 2928; A.,1929, 58.6 5 F. Bryans and F. L. Pyman, J., 1929, 649; A., 1929, 577. CompareAnn. Reports, 1926, 23, 136.66 R. Forsyth and F. L. Pyman, J., 1930, 397; A., 618. Compare Ann.RepOTt8, 1924, 21, 110ORCANIC CHEMISTRY .-PART 11. 143Polar In@ences on Properties and Rectctions.Elimination Reactions. Exha;ustive Methylation.--In a series ofpapers on the modes of' decomposition of quaternary ammoniumand phosphonium compounds and of sulphones, C. K. Ingold andhis assistants have elucidated the mechanism of the four reactionswhich may occur and the structural conditions which determinetheir relative imp~rtance.~' The first of these (A) is the olefin-elimination familiar in the Hofmann degradation, which takes placeaccording to the scheme :Wide variations of the structure of the quaternary base affect thisreaction in the expected manner.Substitution in the c(-CH2 haslittle effect and, if complete (absence of a-H), does not preventreaction A. On the other hand, the character of R hastens orretards it by promoting or suppressing the incipient ionisation ofthe p-H. Elimination of ethylene (R = H) is thus more ready thanthat of higher alkylenes (R == alkyl), but styrene (R = Ph) and stillmore p-nitrostyrene are liberated with great ease in accordance withthe known repulsion of electrons by alkyl and attraction by phenyland nitrophenyl.When reaction A is difficult, the second reaction B occurs, whichmay be written :This reaction, as the theory requires, becomes increasingly importantif R and R1 contain chains of carbon atoms which branch or extend-the latter effect becoming constant for chains of more than fouratoms.Reaction C, characteristic of phosphonium hydroxides, involvesthe elimination of a paraffin thus :e e OH 8 @e 8 fH,OE3R,P + OH T+= R4P*OH ---+ R4P0 -+ R,PO + R --+ RH + Ok67 C.K. Ingold with W. Hanhart, J., 1927, 997; C. C. N. Vass, J., 1928,3126; G. W. Fenton, J., 1928, 3127; 1929, 2338, 2342; 1930, 706; J. A.Jessop, J., 1929, 2357; 1930, 708, 713; A., 1927, 650; 1929, 171, 176, 1423,1431 ; 1930, 73, 739, 759. Compare J. v. Braun, W. Teuf€ert, and K. Weiss-bach, Annalen, 1929,472, 121 ; A., 1929, 1046144 BENNETT AND CHAPMAN :The formation of the undissociated form of the base must involvean increase to ten in the number of electrons in the outer shell ofthe phosphorus atom.As the nitrogen atom is unable t o increaseits outer shell, reaction C is impossible with ammonium compounds.The radical R eliminated as paraffin should be that which besttolerates a negative charge, and this is verified by a long series ofcomparative decompositions. Readiness of elimination is in theorder benzyl > phenyl > methyl > p-phenylethyl > ethyl > higheralkyls : carbethoxymethyl is eliminated with great ease.Reaction C is very facile for phosphonium hydroxides and con-sequently reaction A is then not normally observed, but by selectinga case where A should be favoured it was found in fact to take place :the hydroxide CHPh,*CH,$Bu,} 0"H gave the olefin CPh,:CH2 andthe phosphine as principal products.Decomposition of sulphones tends to follow a reaction similart o A :H13 E d R-CH-CH,-SO,*Alk + 0"H -+ R*CH:CH, + ALk*S8, -t- H,O,an alkylene and a sulphinate being produced.Substitution of other negative ions for hydroxyl should affectthe extent to which reaction A takes place in any instance.It isfound in fact that in the decomposition of the hydroxide, phenoxide,and m-nitrophenoxide of a quaternary ammonium salt reaction Bis progressively increased a t the expense of A, the negative ionsinvolved being in order of diminishing proton-a,ffinity. On theother hand, the ethoside ion has a greater proton-affinity thanhydroxyl. Consequently the sulphone disruption is brought aboutby sodium ethoxide in many cases where it fails with sodiumhydroxide.Sulphones may also exhibit reaction C, the order in which theradicals tend to this type of elimination being, as the theory requires,the same as for the phosphonium hydroxides.Finally, a fourth reaction (D) involving 1 : 1-elimination some-times occurs when @-H atoms are absent :n I f3@H"0 + H-CRR1--NR, -+ H,O + CRR1+ NR,The methylene, CRR1, having only a sextet of electrons, immediatelypolymeriaes or isomerises.This has been observed with fluorenyl-trialkylammonium hydroxides (which yield bis-00'-diphenylene-ethylene), with the analogous sulphonium hydroxide, and withbenzylmethylsulphone. The order of facility of methylenic extruORGANIC CHEMISTRY .-PART 11.145sion (D) is : g-fluorenyl> benzyl>methyl, which correctly followsthe order of anionic ~tability.5~Strengths of Carboxylic Acids.-Dibasic acids. According to thetheory of N. Bjerrum 59 the free pole of one carboxyl group of twopresent in a molecule will affect the active mass of hydrogen ionsnear the other (about to dissociate), so that the following relation willhold : log KJK, - 0.6 = 3.1 x 10-8/r, where K, and Kz are thefirst and second dissociation constants of the dibasic acid and r isthe distance between the ionic centres.The subject has been taken up by R. Gane and C. K. IngoldYGowho from measured values of K , and K2 find the following valuesof r in A. for the normal acids CO,H*[CH,],*CO,H :r, A ..........1.5 5.0 9.2 11.6 13.2 14-5 16.8Various effects which must tend to influence these figures are dis-cussed. A large distortion of the results must arise from polareffects, of which the chief will be the inductive effect of one carboxylgroup on the ionisation of the other-tending to make the apparentvalue of r too small.From the third to the seventh acid in the above list the values of rare fairly regular with an average increase of 1.73 8. per CH,. Thedifference between this and the average distance in the crystal(1 *26 A.)61 is regarded as representing the systematic error due tosolvation and electrostriction. The large deviation from the seriesof values of r shown by the first two members represents the polareffects mentioned and is vanishingly small when three carbon atomsare interposed between the pole and the carboxyl.n = 1 2 3 4 5 6 7This result and those obtained in nitrating the saltsPh*[CH,],*NMe,)X 62justify the use of comparative values of r found for p-substitutedglutaric acids in connexion with the valency-deflexion hypothesiswithout fear of error due to the polar effects of the alkyl groups.63A series of determinations with mono- and di-substituted malonicacids, CRR1(CO,H),, gave values of the apparent distances r betweenthe carboxyl groups.The order of these is dissected in a mostconvincing manner and shown to be not only qualitatively butsemi-quantitatively such as should result from the combinedoperation of the valency-defiexion effect (confirmed in the p-substi-pare Ann.Reports, 1928, 25, 121.58 Benzybmethyl in order of either anionic or kationic stability. Com-2. physikal. Chem., 1923, 106, 219; A., 1923, i, 1059.6o J., 1928, 1594, 2267; 1929, 1691; A., 1928, 846; 1929, 1144. Compare61 W. A. Caspari, J., 1928, 3235; A,, 1929, 126.62 Ann. Reports, 1926, 23, 131.also A. I. Vogel, J . , 1929, 1476; A., 1929, 1009.63 This vol., p. 153146 BENNETT AND CIEAPMAN :tuted glutaric acids) and the known internal polar effects of thealkyl groups.The enhanced strength of all o-substi-tuted benzoic acids was ascribed by B. Flurscheim 64 to a sterichindrance effect. But a pure steric hindrance, although it mightaffect the speed of dissociation, should not affect the equilibrium-position.This particular effect of ortho-substituents is betterascribed t o a direct polar effect of the substituent on the carboxylThe effect of the methyl group in the o-position is also toincrease the strength of benzoic acid, although its familiar polareffect is to weaken an acid. This indicates the existence of a widelyspread electrical field outside the methyl group of an electron-attracting kind : a similarly reversed field must exist outside anypolar group at a point on its axis produced into space.66Attention may here be directed to recent determinations of thestrengths of the halogenobenzoic acids, the phthelic p-cyano-benzoic acid, 68 and a- and p-selenocyanopropionic acidsY6O fromwhich the cyano- and selenocyano-groups are seen to approach thenitro-group in degree of polarity.HydroZysis of Esters.-It has for some time been clear that thevelocities of hydrolysis and esterification must be influenced by bothpolar and steric hindrance factors.It was essential to find amethod of observing the effects separately or of discriminatingbetween the two effects when superposed. The speeds of alkalinehydrolysis of m- and p-substituted benzoic esters determined byK. Kindler 7O illustrate the separate polar effect, for steric hindrancedue to the substituents must here be negligible. The attack is byhydroxyl and consequently the reaction is facilitated by electron-attracting groups .An important method for revealing the polar influences in esterhydrolysis independently of steric effects has been developed byC.K. IngoldY7l starting from the views of H. M. Dawson and ofSubstituted benzoic acids.64 J., 1909,95,718; 1910,97,84; Chem. andInd., 1925,44, 246.66 A. Lapworth and R. H. F. Manske, J., 1928, 2533; A., 1928, 1245.66 G. M. Bennett and A. N. Mosses, J., 1930, 2364; A., 1555.6 7 R. Kuhn and A. Wassermann, Helv. Chim. Ada, 1928, 11, 31, 44; A.,6 8 E. P. Valby and H. J. Liicas, J. Amer. Chem. SOC., 1929, 51, 2718; A.,69 A. Fredga, J. pr. Chem., 1929, [ii], 121, 56; A., 1929, 426.'O Annalen, 1926, 450, 1 ; A., 1927, 55.1928, 240.1929, 1384.Compare Ann. Reports, 1928, 25,147, where these results were, owing to an error in abstracting, stated in theinverted order. The speeds of hydrolysis fall in the order of diminishingstrengths of the substituted benzoic acids.71 J., 1930, 1032, 1375 ; with (Miss) C.M. Groocock and A. Jackson, ibid.,p. 1039; A., 868, 869, 1131ORUANIC CHEMISTRY.-PART 11. 147J. N. Bronsted on reaction catalysis. Whatever may be the detailedmechanism of the reactions,72 the alkaline hydrolysis depends onthe action of hydroxyl and the acid hydrolysis on the action ofhydrogen ions. It is demonstrated that the ratio of the velocitiesof alkaline and acid hydrolysis, koH/kH, is probably within widelimits a function of polar factors only (the steric effects cancellingout).in which pH* is the hydrolytic stability maximum orpoint of minimumhydrolysis and K , is the ionic product for water. The progressivepolar effects of methyl groups in the hydrolysis of alkyl acetates isshown by the following figures calculated from data available :Alkyl Me CH,Me CHMe, CMe,lo-' ( k 0 ~ I h 4 16.1 9.9 4.7 1.5Use is made of Dawson's relation : 73- - log KV = log ( k o ~ / k ~ )An extended series of alkyl groups has been studied by using thewater-soluble glyceric esters in solutions buffered with sodiumglycerate. The order of falling k,,=/kH ratio was Me>Et>Pr>Bu>Am>iso-Am>iso-Bu> iso-Pr, which is clearly in accord withthe usual inductive effects of the groups.In the third memoir the author discusses the various factorscontrolling the speeds of hydrolysis of esters.The statistical factorleads to the expectation that the ratio of the velocities of the firstand second stages in the hydrolysis of a symmetrical dicarboxylicester, k1/k2, should be 2.0, and this is true if the ester groups areseparated by at least two carbon atoms.Otherwise the pohrfactor is also important. Consideration of the influence of one poleon the reaction at the second carbethoxyl leads for symmetricaldicarboxylic esters to k J k 2 z 2 exp(7/108r) and the values of rdetermined in this way are in general agreement with those foundfrom the dissociation constants. 74 A systematic consideration isalso given to steric hindrance and the influence of the medium.Types of Polar Eflect.-It has recently been emphasised by A.Lapmorth and R. H. F. Manske 75 that the effect ef a substituent onthe reactivity of adjacent atoms observed experimentally mayresult from several superposed influences difficult or impossible toseparate. The terms " quantitative " and '' electropolar " factorsused by B.Flurscheim 76 are advocated ; the former being indicatedby the op-directive action of a group, and the latter by a comparison72 T. M. Lowry, J . , 1925, 127, 1371; J. W. Baker, J., 1928, 1583; A , ,1925, i, 886; 1928, 870.73 J., 1927, 1146; A., 1927, 632.74 This vol., p. 145.7 5 J., 1928, 2533; A,, 1928, 1246. 76 L O G . cit148 BENNETT AND CHAPMAB :of the strengths of the m- and p-substituted benzoic acids with thatof benzoic acid.The increase in availability of electrons at A, when H-A, isconverted by substitution into A-A, is termed the “primaryinternal effect ” of A and is written Z--Al.Examination of the stabilities of a further series of ketone cyano-hydrins shows that the introduction of an alkyl group has (a) 8stabilising “ steric effect ” a t close quarters and ( b ) a destabilisingelectropolar influence at points more remote.77The effect of the oxygen atom in MeO*CH,Cl is to increase theincipient anionisation of the chlorine, which consequently showshigh reactivity.In a similar way, although the cyanogen group hasa tendency to particularly stable covalent attachment to carbon, theaddition of alkali to HO*CR,*CN produces O*CR,*CN and here thecyanogen becomes rapidly ionised : the aminonitrile NR,*CHMe*CNis highly unstable. These are cases of an effect related to that ofop-direction in which the order of efficiency is O>NR,>OH andBoth a- and p-chloro-sulphides (and the analogous hydroxy-compounds) are reactive in a similar manner,79 but the y-substitutedsulphides are entirely unactivated.The effect thus dies out at adistance of the same order as that found in the dicarboxylic acids(p. 145). The 8-hydroxy-sulphidey however, shows a remarkablereactivity which may be attributed to a large activation at momentswhen the CH,*OH group is near the sulphur atom in space, an eventstereochemically probable.80The possibility should be borne in mind of interpreting theknown facts of both aliphatic and aromatic chemistry in terms oftwo polar effects only : namely, the general polar or electropolareffect (to be regarded as of the nature of both I and D) and theconjugative or tautomeric effect (5!’).81 It is at least significantthat the effects D and I have been described as similar “ in sign andmagnitude in .. . variation as between one directing group andanother,” 82 and there appears to be no definite evidence that theinductive effect is propagated along saturated carbon chains morethan through space. On the other hand the inability of internalz-- A€3eoMe.787 7 A. Lapworth and R. H. F. Manske, J . , 1930, 1076; A . , 1251 ; compare7 8 W. Cocker, A. Lapworth, and A. Walton, J., 1930, 446; A . , 571.‘9 G. M. Bennett and A. L. Hock, J . , 1927, 477; A . , 1927, 365.80 G. M. Bennett and A. N. Mosses, Zoc. cit. (Ref. 66; p. 14G).81 For symbols I, T, and D, see Ann. Reports, 1927, 24, 151 ; 1928,25, 140.82 C.K. Ingold, Zoc. cit. (Ref. 33; p. 138).Ann. Reports, 1928, 25, 147ORGANIC CHEMISTRY.-PART 11. 149polar effects in aliphatic compounds to penetrate beyond thesecond carbon atom and the parallelism with op-directive effectssuggest that they are essentially of the tautomeric kind.Stereochemistry .A valuable general discussion of optical rotatory power has beenheld during the year.83 The investigations of W. Kuhn 84 haveprovided us with a relatively simple theory of the mechanism of theoptical activity of dissymmetric molecules, and are of the greatestimportance in connexion with the study of rotatory dispersion andof the relation between rotatory power and chemical constitution.Stereochemistry of Elements of the Xulphur Goup (continued fromAnn.Reports, l927,102).-The following results and others describedbelow under " cis-trans isomerism of ring compounds " affordabundant evidence in support of the newer view of the steric dis-position of the atoms or groups round the sulphur atom in sulphoxidesand sulphilimines .The resolution of the sulphoxide and the sulphilimine derived fromm-carboxyphenyl ethyl sulphide, namely, the compounds (I) and(11), into their optical antipodes by means of their alkaloidal saltsconfirms the earlier results. The occurrence of aromatic disul-phoxides as pairs of diastereoisomerides has been shown in eightCO,HCGH4*C0,H + CGH**CO,H -(1.1 (11.1"-"<, 2 5 C7H7*S02*%--S G , H 5 ss()g<e, (111.)instances, in four of which a single dioxide had been recorded in theliterature.86 Of the two dioxides (111) of 3 : 5-dimethylthiolbenzoicacid, one was found to be resolvable into optically active forms asrequired by theory whilst the other resisted resolution and is there-fore internally compensated.An anomaly of long standing has been removed 87 by the re-examination of the mercuri-iodides of optically active sulphoniumsalts.It is now' found that the mercuri-tri-iodide and -tetraiodide,83 Trans. Faraday Soc., 1930, 26, 266; A., 980.84 2. phyeikal. Chem., 1929, [B], 4, 14; Ber., 1930, 63, [B], 190; A., 1929,W. Kuhn and E. Knopf, 2. physikal. Chem., 1930, [B], 7, 981; 1930, 276.292; A., 717.85 J. Holloway, J. Kenyon, end H. Phillips, J., 1928, 3000; A., 1929, 65.86 E.V. Bell and G. M. Bennett, J., 1928, 3189; 1930, 1 ; A., 1929, 179;Compare1930, 340.W. J. Pope and A. Neville, J., 1902, 81, 1652.M. P. Balfe, J. Kenyon, end H. Phillips, J., 1930, 2554150 BENNETT AND CHAPMAN :B[HgI,] and B,[Hg14] (where B is phenacylmethylethyhulphonium),and also the cadmi-iodides, B2[Cd14] and B,[CdI,], are obtainablewith considerable rotatory powers but racemise somewhat readilyin aqueous solution in presence of iodides.The isolation of enantiomorphous selenonium salts followedrapidly after that of the sulphonium salts, but correspondingevidence in the case of telluronium compounds has hitherto beenlacking. The revision last year 88 of our views as to the nature ofR. H. Vernon's telluronium di-iodides prepared the way for theannouncement 89 of the isolation of phenyl-p-tolylmethyltelluroniumsalts in optically active forms having [M],,,, of about 70".Theactivity is fugitive, but it indicates that the attached radicals intelluronium compounds are arranged in a similar way to those insulphonium compounds.Optically Active aci-Nitroparafim and Diaxo-compounds. Semi-polar Bond to Carbon.-The remarkable results of R. Kuhn andH. Albrecht in 1927 have been completely confirmed by an examin-ation of optically active (3-nitro-octane. The nitro-compoundrecovered from the solution of its alkali salt by acidification at- 70" retains more than 70% of its activity. The formula (I)is necessary for the optically active ion, possibly stabilised as asolvate such as (11).The fact that the rotation of the alkalinesolution is not affected by keeping for 24 hours seems to exclude theidea that the active ion is in tautomeric equilibrium with the form[RR1C&(?1-. A substance of the structure RR1C-N-OH mayL \oJpossibly be involved.g1CH,-CMe*CO,Me(111.1 I >CMe,CH,-CH-NH,'0'A similar problem is presented by the occurrence of opticalactivity in aliphatic diazo-compounds. The original formulaAnn. Reports, 1929, 26, 80.T. M. Lowry and F. L. Gilbert, J., 1929, 2867; A., 1930, 232.R. L. Shriner and J. H. Young, J. Amer. Chem. SOC., 1930, 52, 3332;O 1 G. E. K. Branch and J . Jaxon-Deelman, J . Amer. Chem. Soc., 1927, 49,A., 1269 : compare Ann. Reports, 1927, 24, 103, 107.1766; A., 1927, 852ORGANIC CHEMISTRY.-PART 11.151NNR,C<I I for these substances had been largely abandoned in favourof the open-chain formula, which, according to modern views, maybe either R2C=N=Nx or R2Y--EN- ; 92 but recent discussionof the physical properties of these substances and the closely relatedazides has led to the revival of the earlier formula and they are nowregarded as partly or wholly cyclic.93On the other hand, the possibility of the occurrence of opticallyactive diazo-compounds was indicated in 1920 and succeedingbut the observed rotations of the products from which theexistence of the active diazo-compounds was inferred were small.The dissymmetry of the carbon atom bearing a diazo-group has nowbeen shown in a more convincing manner by the work of F.E. Ray,g5who has isolated and compared the modes of decomposition of thediazo-esters from methyl cis- and trans-aminocamphonanates (111),in the molecule of which there is one asymmetric carbon atom apartfrom that carrying the amino-group. Decomposition of the cis-diazo-compound at low temperatures with dilute acid gave 39.5%of hydroxy-esters and 60.5% of unsaturated esters as compared with68% and 27% of these products respectively from the trans-diazo-compound (of 90%. purity). This difference of behaviour points tothe existence of diastereoisomeric diazo-compounds and an opticallyactive form RR1-$+B-- which may perhaps be in tautomericequilibrium with the cyclic form.Both the aci-nitro-paraffin and the aliphatic diazo-compoundthus appear to have in their molecules a semi-polar bond betweencarbon and nitrogen.The isolation of dimethylsulphoniumfluorenylidide 96 (IV) provides a case of such a bond between carbonand sulphur and strengthens the case for the existence of theanalogous nitrogen compound. The decomposition of the latterwith production of bisdiphenylene-ethylene is similar to the form-ation of tetraphenylethylene from diphenyldiazomethane.Ring Pormation and Stability.-R,eduction of the large ringmono- and di-ketones (Ann. Reports, 1928, 25, 112) by the Clem-92 Ann. Reports, 1922,19, 86.93 Ann. Reporb, 1929, 26, 183; H. Lindemann, A. Wolter, and R. Groger,Ber., 1930, 63, [B], 702; A., 686.94 C. S. Marvel and W. A. Noyes, J . Amer.Chem. SOC., 1920,42, 2269; A,,1921, i, 15; H. M. Chiles and W. A. Noyes, ibid., 1922, 44, 1798; A., 1922, i,924; P. A. Levene and L. A. Mikeska, J . Biol. Chem., 1921, 45, 693; 1922,52, 486; A., 1921, i, 233; 1922, i, 818.Compare F. E. Kendalland W. A. Noyes, ibid., 1926, 48, 2404; A., 1926, 1134.~e 0 @0 @s5 J . Amer. Chem. SOC., 1930,52, 3004; A., 1281.96 C . K. Ingold and J. A. Jessop, J., 1929, 2367; 1930, 713; A., 73, 769152 BENNETT AND CHAPMAN :mensen method has now been described 97 and the resulting cyclo-paraffins having rings of 12-16 and 22-30 carbon atoms have beenexamined together with some new diketones as shown in the tableof m. p.'s below :Mono-Di-ketones - - - - 41" 32 36 42 45 - - -ketones - - - - - - 65 69 73 - - 78"The production of analogous five- and six-membered (hetero-cyclic) rings by internal sulphonium salt formation from phenyl8-chlorobutyl and c-chloroamyl sulphides proceeds as a measurablefirst-order reaction and at 80" the five-membered ring is producedseventy-six times as fast as the six-membered.This ratio is remark-ably close t o that (70 : 1) found for the similar ring-closure whichoccurs in 8- and c-chloro-amines in presence of alkali.98 Theauthors regard this ratio as being a measure of the statistical proba-bilities of approach within atomic distance of the two ends of thefive- or six-atom chain during the course of molecular vibrationswithout appreciable strain.The Valency-dejexion Hypothesis.-A number of further applic-ations of the Thorpe-Ingold hypothesis have been made in recentyears, of which one or two will be selected for mention.The large effect on ring stability caused by the presence of twogemdimethyl groups is well illustrated 99 by the fact that, whereasas-diacetylbutane is a normal diketone (V), the correspondingtetramethyl compound reacts exclusively in the cyclic form (VI).CH,-CH,-COMe(V.) ICH2-CH2*COMeCMe2-CH, I >CMe*OH (I7I.)CMe2-CH*COMeA similar progressive influence is evident among the three com-pounds (I), (11), and (III),l the introduction of two successivemethyl groups into the open-chain compound (I) converting it firstinto a ring-chain tautomeric mixture (11) and then into a stablering compound (111) :9 7 L.Ruzicka, M.Stoll, and others, Helv. Clhim. Ada, 1930, 13, 1152; P I . ,1422.9* G. M. Bennett, F. Heathcoat, and A. N. Mosses, J., 1929, 2567; A.,61 ; H. Freundlich and A. Krestovnikov, 2. physikal. ClLern., 1911, 76, 79;A., 1911, ii, 266.9a I. Vogel, J., 1927, 594; A., 1927, 449.1 E. Rothstein and C. W. Shoppee, J., 1927, 531 ; A . , 1927, 447ORGANIC CHNMISTRY . -PART 11. 153CHMe*CO,H CHMeCOhMe2* co *CO,H CMe, I *CO*C02H &Me2-,$H)*C0,HCH,*CO,HL Y (I, stable.) (11, tautomeric mixture.)CMe,--COCMe,--C( OH)*CO,H(111, stable.)I >oThe speeds of alkaline hydrolysis of substituted malonic esterwere found by R. Gane and C. K. Ingold2 to be in the followingdescending order : cyclopropane- 1 : l-dicarboxylic ester > cyclo-butane-1 : l-dicarboxylic ester>gem-dimethylmalonic ester>cycZo-hexane- 1 : 1-dicarboxylic ester>gem-diethylmalonic ester.Thisorder agrees in the main with the series of valency angles 8 computedfor groups R,C4 and C,>Cd.Other recent investigations of the valency-deflexion effect haveconcerned keto-lactol tautomeric mixtures, cyclic anhydrides,imides, and lac tone^.^The valency-deflexion hypothesis has been criticised by W.Huckel and defended by its a ~ t h o r s . ~ There shouId now be nodoubt that the work carried out with its aid has abundantly showna graduated alteration of the ease of closure and the stability ofrings by the presence, in the chain of carbon atoms from which therings are formed, of a group of the type R2C< or Cn>C<.Thecomputed valency angles do in general agree in respect of theirorder with the order deduced from experiments, but they cannot,as the authors admit, be regarded as having more than a qualitativesignificance.The contention that polar effects should not be admitted tosimultaneous consideration is unwarranted, for cases can be selectedwhich demonstrate the valency deflexion and polar effects inde-pendently, and their combined effects in more complicated caseshave been analysed with remarkable success. In the psubstitutedglutaric acids the polar effects of the substituents on the carboxylgroups are in general negligible, and the distances between the twoionising groups calculated from the first and second dissociationconstants are in the order : glutaric acid,>p-methylglutaric acid>J., 1926, 10; A., 1926, 249.M.Qudrat-i-Khuda, J., 1929, 1913; 1930, 206; A., 1929, 1273; 1930,471; E. H. Farmer and J. Kracovski, J., 1927, 680; A., 1927, 447; S. S. G.Sircar, J., 1927, 600, 1252, 1257; 1928, 898; A., 1927, 451, 756; 1928, 618.Fortschritte der Chernie, Physik und p?tysikalischen Chemie, 1927, 19, 4;J . , 1928, 1318; A., 1928, 1173.This VOI., p. 145154 BENNETT AND CHAPMAN :p -n-propylglutaric acid > p p'- dimethylglut aric acid > cyclopentane-1 : 1-diacetic acid> cycloheptane-1 : 1 -diacetic acid>cyclohexane-1 : l-diacetic acid> pp'-diethyl- and pp'-dipropyl-glutaric acids.6This is not only in general agreement with the valency-deflexionhypothesis, but in detail reproduces minor peculiarities previouslydiscovered by experiments on the closure and stability of rings.The influence of the cyclohexane ring on the valency angle appears,a t first sight, to constitute it serious anomaly.That ring wasoriginally shown to confer added stability on a three-memberedring sharing a spiran carbon atom with it.' Such an effect had beenexpected, for the angle of 120" of a phne hexagonal ring shouldcause the external valency angle to fall to lO7a". But from ourpresent knowledge of strainless forms of rings of six or more carbonatoms, in which the angles presumably approximate to the tetra-hedral value of this result evidently needs furtherconsideration.An experimental discovery of the failure of a large ring to exertthe effect originally anticipated was announced for the case of theseven-membered ring by J.W. Baker and C. K. Ingold in 1923 8and the suggestion that the ring relieved its strain by becomingnon-planar was then made, independently of the announcement ofthe isolation of the fist static isomerides with fused non-planarrings.g Yet the influence of the six-carbon ring originally observedhas been repeatedly confirmed and the cycloheptane ring has con-sistently exerted an effect lying between those of the cyclopentaneand cyclohexane rings. This may be justified as follows : 10 somestrain is necessarily involved in the interconversion of the twopossible strainless forms of the cyclohexane ring, and, as isomericforms have not been isolated, it must be assumed that such aninterconversion is continually taking place in the course of molecularagitation and vibration, so that the average effect of the ring is thatof a partly strained and not a strainless form.If the cycloheptanering becomes strained by molecular vibration, this may be of lessduration than in the six-membered ring, so that the average strainmay be in the order 6-ring>7-ring>5-ring. This seems the morecredible from a consideration of the fact that movements involvingrotation round a bond may be more easy in the cycloheptane ring,so that an almost strainless interconversion of forms should occur.The valency-deflexion effect of the trans-decalin ring has been6 R. Gane and C. K. Ingold, J., 1928,2267; A., 1928,1083; compare C.H.Spiers and J. F. Thorpe, J., 1926,127, 638; A., 1926, ii, 395.Ann. Reporta, 1916, 12, 109.Ibid., 1923, 20, 103. Ibid., 1924, 21, 92.10 J. W. Baker, J., 1926,lZ7, 1680; A., 1926, i, 1277ORUA'NIC CHEMISTRY.-PART 11. 155investigated recently by K. A. N. Rao,ll who concludes from astudy of tram-decalin- p-spirocyclopropane derivatives that thedecalin ring exerts less influence on the valency angle than the freecyclohexane ring. The yield in ring-closure was the same as withcyclohexane and cycloheptane derivatives : the difference is deducedfrom observations of the disruption of the compounds by acid ofvarious strengths. The facts relating to a series of these spirancompounds and caronic acid are here tabulated for comparison :Mildea t conditionsAcid. for disruption.5% HCl at 200"5 yo HCl a t 200"10 yo HC1 at 240"20% HCl at 240"Stable to 20% HClCaronic acid ..... .. . ... .. . .. ... . ... .. . ... ..... .... .. . ... . . . . . . .. . ... .cycZoPentaneq+ocycZopropanedicarboxylic acid . . . . . .. . .Decalin-&vpirocycZopropanedicarboxylic acid . . . . . . . . . . . .cycZoHeptane8p~roc~cZopropanedicarboxyl~c acid . . .. . . . . .cycZoHex~neep~rocycZopropanedicarboxyl~c acid . . . . . . . . .a t 240'This evidence, as it stands, certainly seems to support the ideathat cyclohexane is more strained than decalin, but it is not decisive.The argument is weakened by the fact that only in the case ofcaronic acid was a definite product of disruption (terebic acid)isolated from these reactions.The fact that tram-decalin-2 : 2'-di-acetic acid was found to be stable under the conditions of the dis-ruption experiment cannot be held to exclude entirely the possibilitythat the decalin nucleus of the spiran is broken, for a condition ofstrain is no doubt imposed upon it by the other rings.Such experiments would in any case afford very indirect evidenceof the valency-deflexion effects, whereas the calculation from thetwo dissociation constants of the substituted glutaric acids is asdirect a confirmation as could be desired.It may be pointed out, in conclusion, that many chemists willconsider it simpler to explain a number of the effects which havebeen studied under this heading as due to steric hindrance ratherthan to a secondary consequence of a valency deflexion.Thisapplies particularly to the experiments on the hydrolysis of estersand the disruption of lactone and imide rings, in which the generalscreening effects of the substituents may be the principal factor.The poly-merisation of mono- and di-chloroacetaldehydes under the influenceof acids yields, in addition to amorphous meta-aldehydes, probablyof high molecular weight, crystalline trimeric para-aldehydes towhich a six-atom ring structure may be given. From chloral, onlypolymerides of the meta type were known, but F. D. Chattaway andE. G. Kellett 12 have obtained by the action of cold sulphuric acid11 J . , 1929, 1964; 1930, 1164; A., 1929, 1297; 1930, 914.11 J., 1928, 2709; 1929, 2908; A., 1928, 1367; 1930, 194.'Stereoisomerism of Ring Compounds.-Parachlorals156 BENNETT AND CHAPMAN :a mixture of two crystalline parachlorals.They were separatedand are no doubt cis- and trans-isomerides, (I) and (11), as arethe two parabutylchlorals similarly prepared from butyl chloralCH,*CHCL*CCl,*CHO. R ? 7cjc13s vr3 R o H O R A\ R O H O H /?\\I / \I g-o--F Q-O-t! HI / F-0--QH H H R HThe analogous trichloralimides (CCl,*CH:NH), have long beenknown.13 The action of sulphuric acid on chloralsulphydrateyielded a mixture of trithioparachloral (one of the two possibleisomerides) and two dithioparachlorals. Three isomerides arepossible (111-V), of which (V) is potentially resolvable. The(1.) (11.) (111.)HAH H CCl, H H H1(IV.) (V.1 (VI.)behaviour of these substances gives some information as to theirconfiguration.Alcoholic potassium acetate removes the elements of hydrogenchloride from trithioparachloral t o give 2 : 4 : 6-trisdichloromethyl-ene-1 : 3 : 5-trithian, CC1,:C >S , and the two dithiopnra-chlorals furnish two distinct bistrichloromethylmonodichloro-methylene compounds, the trichloromethyl group adjacent to bothsulphur atoms being attacked preferentially.The latter productsmust therefore be (VI) and (VII), from which it is clear that either/s-c:cCl2\s--c:ccL,c y,s' '"p cCl,:c(-y:l' CCI,.CCl< S-CCI*CCI, >oT--o----q s-c:cc1, S-CCl*CCI,CCI, H(VII.) (VIII.) (IX.)13 A. BBhal and E. Choay, Ann. Chim. Phys., 1892, 26, 34; Compt.rend.,1890,110, 1270; A., 1890, 1093ORGANIC CHEMT3TRY.-PART 11. 157(111) or (IV) must be the missing third isomeride, as these two wouldyield the same dichloromethylene derivative (VI). One of the twodithioparachlorals isolated is therefore the dl-compound (V).These substances are converted by alcoholic potassium cyanideinto the trisdichloromethylene compound (VIII), the isomerismvanishing. Chlorine combines with this compound to produce thetrichlorotristrichloromethyl derivative (IX), but once again twoisomerides were found in place of the three theoretically possible.In continuation of the studyof the cis-trans isomerism arising from the non-planar configurationof the sulphoxide and related groups l4 several further pairs ofderivatives of 1 : 4-dithian have been described.15 Cautiousoxidation of dithian yielded a monosulphoxide, from which twoisomeric dithian monoxide methylsulphonium salts (I) and twoSulphoxides and elated substances.CH,*CH CH,*CH, 06< '>gMe}X Oi< .y*%*SO,*C,H,(1.) (11.1CH,GH, CH, CH,cis and trans. ci8 and trans.monoxidesulphilimines (11) were prepared. Moreover the bis-sulphilimine of dithian (111) l6 was separated into two distinctisomerides by crystallisation from solvents of high boiling point.CH,. CH,Cq*CH,cis and trans.(111.1 C,H7-SOz*%*6< y*N*S0,*C7H,A closely analogous case is that of the sulphoxides of penthianols,which occur in isomeric pairs of the type (IV).17The oxidation of phenylpenthianol (R = Ph), benzylpenthianol(R = CKPh), and penthianolcarboxylic acid (R = CO,H) gave ineach case two distinct isomerides.The methylsulphonium salt andsulphilimine of phenylpenthianol were also examined : the formerwas separated into cis- and trans-forms which are similar in typel4 Ann. Reporb, 1927, 24, 103.l6 E. V. Bell and G. M. Bennett, J., 1928, 86; A., 1928, 299.16 F. G. Mann and (Sir) W. J. Pope, J., 1922,121, 1052.l7 G. M. Bennett and W. B. Waddington, J., 1999,2832; A , , 219158 BENNETT AND CHAPMAN :to the isomeric 4-substituted piperidinium salts; l8 but a secondisomeric sulphilimine could not be found.to give rise to a single dioxide and a single crystalline trioxide(disregarding a further amorphous oxidation product having thecharacteristics of a substance of high molecular weight).A studyof the regulated oxidation of trithian has now not only led to theisolation of all the theoretically possible mono-, di-, and tri-sulph-oxides derived from it but also provided convincing evidence as totheir configurations.2° The results are summarised in the annexedscheme of oxidations :Trithian monoxideHitherto trimethylene trisulphide (trithian) has been known-~ I- 8-dioxide (3 times asa-dioxide (dimorphous). soluble as a-dioxide).LG I /’ 4 0 -0 CH, CH, 6 C d i C H 2 0S-CH,-S S-CH,---Y- 8-trioxide (10 times as 0I/ \+ I/ \I+ + fa-trioxide. soluble as a-trioxide).The compounds previously known were the @-dioxide and thea-trioxide. The configurations of the dioxides are fixed by thefact that one is oxidised to a single trioxide and the other to bothtrioxides. Moreover the common product of oxidation of bothdioxides is necessarily the tram-trioxide, and the other trioxide thecis-isomeride.The same configurations would have been assignedto these isomerides on the ground of their relative solubilities inwater, and this justifies the configurations previously allocated tothe dithian dioxides.,lIs Ann. Reports, 1927, 24, 102.lD 0. Hinsberg, J . p r . Chem., 1912, [ii], 85, 337; 1913, [ii], 88, 49; A.,1912, i, 546; 1913, i, 818.E. V. Bell and G. M. Bennett, J., 1929, 16; A., 1929, 293.41 Ann. Report8, 1927, 24, 103ORGANIC CHEMISTRY. -PART 11. 159The view that the supposed third isomeride of trithioacetaldehydeis a mixture of the a- and b-compounds has been confirmed.22 Theoxidation of these trisulphides has been re-examined Z3 and, althoughthe numerous possible isomeric sulphoxides were not all isolated,the results supply a definite proof that the configurations allocatedto the trithioacetaldehydes (011 physical grounds) must be reversed.The results are summarieed in the following table :Isomeride.Configuration.a-, m. p. 101" trans (hitherto cis),!I-, m. p. 126' cis (hitherto trans)MeIMe II C-Me Me Me Me ITwo tramkulphones.Oxidation products,expected. found.4 Monoxides 2 Monoxides2 Monosulphones 2 Sulphones2 Monoxides 1 Monoxide1 Monosulphone 1 SulphoneMe Ic--so2--4I I H HOne cis-sulphone.All three possible monosulphones were thus found, and the trithio-acetaldehyde which yielded only one of them must have the cis-configuration.cis-trans-Fwed rings.(1) Octahydronaphthtzlenes. Five isomericoctahydronaphthalenes should be possible (II-IV). Of theseA' cis and trans. Aa cis and tram.(11.1 (111.)A@.hydrocarbons, the trans-A2-isomeride was prepared and examinedby H. Leroux in 1910z4 and the cis-A2-isomeride by W. Borsche22 E. V. Bell, G. M. Bennett, and F. G. Maw, J., 1929,1462 ; A., 1929,1042.23 F. D. Chattaway and E. G. Kellett, J., 1930, 1362; A., 1022.s4 Ann. Chim., 1910, 21, 458; Compt. rend., 1910, 157, 384; A., 1910,ii,828160 BENNETT AND CHAPMAN :and E. Lange in 1923 25 by the removal of hydrogen chloride fromcis- P-chlorodecalin obtained from the decalol.These substancesare oxidised to trans- and cis-cyclohexanediacetic acids (V). Byheating the chlorination product of decalin with aniline, however,the same authors obtained a slightly impure specimen of the A1-octa-hydronaphthalene, presumably a mixture of isomerides, givingas principal oxidation product 1-carboxycyclohexane-2-propionicacid (I).Both cis- and tram-A*-isomerides may be obtained by thedehydration of the respective @-decalols with potassium bisulphate.26Attempts had been made to prepare the A9-isomeride by nitratingdecalin with boiling dilute nitric acid, reducing the resulting 9-nitro-decalin to the amino-compound, and decomposing this with nitrousacid.27 The researches of W. Hiickel and his assistants indicate thatthis method yields a mixture.28 The pure substance has now beenprepared and its structure carefully established.It may beobtained, by a complex reaction involving more than one rearrange-ment, by the dehydration of 2-cycZopentylcycZopentanol (VI) (cisor tram) with zinc chloride. It has also been separated from themixture of isomeric octahydronaphthalenes (produced by thedehydration of decalol with zinc chloride) in the form of its bluecrystalline nitrosochloride, and is regenerated from this by theaction of sodium methoxide.The structure of this octahydronaphthalene is confirmed by itsconversion by ozone in acetic acid into cyclodecane-1 : 6-dione (VII)and S-ketosebacic acid (VIII).In the course of a study of spiran form-ation in this series K.A. N. Rao 29 has realised a number of cases of(2) Demlin-p-spirans.25 Annalen, 1923, 434, 219; A., 1924, i, 32.es W. Huckel and H. Friedrich, Annalen, 1926, 451, 132; A,, 1927, 239;compare F. Eisenlohr and R. Polenske, Ber., 1924, 57, [ B ] , 1639; A., 1924, i,1291.27 S. Nametkin and others, Ber., 1926, 59, [B], 370; 1929, 62, [BJ, 1570;A., 1926,508; 1929, 921.28 W. Huckel, R. Danneel, A. Schwartz, and A. Gercke, Annalen, 1929,474,121 ; 477, 99; A , , 76,206.29 LOC. cit. (Ref. 11 ; p. 155)ORGANIC CHEMISTRY.-PBRT 11. 161X complicated isomerism. Substances of the type CgH,,>C<yderived from cis- and trans-decalins should occur in four isomericforms, two from each of the isomeric decalones. Two p-decalin-2 : 2’-diacetic acids (X = Y) were prepared, a single substance fromeach ketone, and each gave an anhydride.Their anilic acids, how-ever, (X and Y different) involve the additional isomerism and all fourforms of C g H 1 , > C < ~ ~ : ~ ~ & p h were separated, passing by lossof water into two anils, C,H16>C<g2:gg>NHPh. The decalin-p-spirocyclopropane-1 : 2-dicarboxylic acids and the derived lactonicCH-CO,Hwere also studied, and of the latter all acids CgH,,>four possible isomerides from one decalone were isolated.(3) Octcthydrohe~taquinolines. The variation in the proportionsof two stereoisomerides produced in different methods of reductionof heterocyclic bases was referred to in the last Report (Ann.Reports, 1929, 26, 165).In the light of this fact the reductionof tetrahydroheptaquinoline (I) has been repeated,m and it is nowfound that the use of sodium and alcohol produces a second isomeric<Ci*octahydro-base (11) inresulting knowledge ofaddition to that -&ready de~cribed.~~ Thethe properties of these substances has led tothe detection of this second isomeride in the product of reductionby tin and hydrochloric acid and in the reduction product of theketo-compound (111).Adirect demonstration of the enantiomorphism of a single allene asforeseen by J. H. van ’t Hoff is still lacking, and the view that thefour terminal valencies in allene are co-planar was recently advanced32on the ground of the homogeneity of a substance described as diethyldi-I-menthyl allenetetracarboxylate.It has been shown, however,that the substance is not an allene derivative at all.33Several new instances have been reported of the separation intoso S. G. P. Plant and R. J. Rosser, J., 1930, 1840; A., 1297.31 Ann. Reports, 1928, 25, 184.32 F. Faltis, J. Pirsch, and L. Bermann, Ber., 1930, 63, [B], 691 ; A., 678.3* C. K. Ingold and C. W. Shoppee, J., 1930, 1619; A., 1163.REP.-VOL. XXVII. PMolecular Dissymmetry.-Allene, spiran, and related types162 BENNETT AND CHAPMAN :optically active forms of a compound belonging to the fascinatinglysymmetrical class of spirans. The resolution of cyclobutanespiro-cyclobutane-1 : l-dicarboxylic acid (I) is due to H. J. Backer andH. B. J. Schurink,34 and the compounds (II-V) have been shownto be enantiomorphous by J.Boeseken and his assistant^.^^The potassium borotartrate isolated by T. M. Lowry is probablyof the same type.36The recorded rotatory powers of those of the above compoundswith spiran carbon as centre are very small. Apart from theprobability of ready racemisation, it may be noted that the opticalrotatory powers of substances of such complete symmetry andsaturation in the immediate vicinity of the central atom are to beexpected to be exceptionally small.A heterocyclic spiran of remarkably simple type has beenresolved by Sir W. J. Pope and J. B. Whit~orth.~7 The rotationof this spiro-5 : 5-dihydantoin (VI) is reversed in sign in ammoniacalsolution, probably owing to enolisation in salt formation.The announcement has been made of the resolution of the o-carb-oxyphenylhydrazone of methyltrimethylenedithiocarbonate (VII)by W.H. Mills and B. C. S a ~ n d e r s . ~ ~NH*COp/NH-TO CO*NH I \CO-NH C H 7 5 E 2 S (VII.)(VI-1 N\NH*C,H4*C02HThis new and clear evidence of the non-planar disposition of thevalencies of the doubly linked nitrogen atom is of particular34 Proc. K . Aicad. Wetenech. Amsterdam, 1928, 31, 370; A., 1928, 1134,36 Rec. trav. chim., 1926, 45, 919; Bey., 1929, 62, [ E l , 1310; A., 1927, 132;s6 J., 1929, 2863; A., 136. Compare E. Damnois, J . Chim. physique, 1930,87 Chem. and Ind., 1930, 49, 748.s8 Trans. Paraday SOC., 1930, 26, 431 ; A., 1096.1929, 791 ; compare Ann. Repwta, 1929, 26, 74.27, 179; A., 864OWANIC CHEMISTRY.-PART II.163importance owing to the possible alternative explanation of thedissymmetry of the pyridylhydrazone of cyclohexylene dithiocarbon-ate resolved in 1923.39Dissymmetry due to restricted rotation. This field of work con-tinues to attract considerable attention. The past year has seenthe extension of the phenomenon to a quinoline derivative and therealisation of the diastereoisomerism consequent on its occurrencetwice in the same molecule.A quaternary salt derived from 8- benzenesulphonylethylamino-quinoline has been resolved with the aid of bromocamphorsulphonicacid by W. H. Mills and J. G. Bre~kenridge,~~ the optically activeiodide (I) being obtained.In the diphenyl series the following have been resolved : 2 : 4-di-nitro-2’-methyIdiphenyl-6-carboxylic acid (corresponding acids withthe methyl group absent or in position 3’ could not be resolved),4O2 : 4 : 6 : 2’ : 4’ : 6’-hexanitrodiphenyl-3 : 3’-dicarboxylic acid, and2 : 4 : 6 : 2’ : 4‘-pentanitrodiphenyl-3-carboxylic acid.41 A generalreview of this type of isomerism has been given with an analysis ofthe possibilities of interference of various atoms and groups judgedfrom their dimensions as ascertained from X-ray crystal data.The inactive diastereoisomerides (11) and (111) have been isolatedby E.Browning and R. Adarn~,~2 which are oxidised to a commonquinone. The obstruction of rotation thus disappears with theremoval of two hydrogen atoms and the change of the centralnucleus to the quinonoid form.Stereoisomerism of Co-ordination Compounds.-Optical activitydependent on 6-co-ordinated copper has been realised by W.Wahl 43in the diethylenediaminediaquocupric salts, of which the active ionis estimated to have [MI = - 190”. Indications of a similaroptically active compound of 6-co-ordinated nickel were obtained.30 Ann. Reports, 1927, 24, 99.40 (Miss) M. S. Lesslie and E. E. Turner, J., 1930, 1768; A., 1287.4 1 R. Adam and others, J . Amer. Chem. Soc., 1930, 52, 1200, 2064, 2070,42 Ibicl., 1930, 52, 4098.‘8 Acta Sci. Fennicce Comrn. Phg8. Math., 1927, 4, 1 ; A., 1928, 396.2959, 447, 4628; A., 762, 911, 914, 1180164 BENNETT AND CHAPMAN :Structure of m p m n d s of 4-w-mdimted platinum. The questionof the planar or tetrahedral disposition of the valencies of 4-co-ordinated platinum was mentioned in the Report for 1927.44 Sincethat time the idea that the arrangement of the four valencies oftellurium is planar has been abandoned.45 F.G. Angell, H. D. K.Drew, and W. Wardlaw have now reinvestigated the two isomericcomplexes of platinous chloride with diethyl sulphide, described byBlomstrand in 1888, and regarded as of cis- and trans-planar con-figurations by A. Werner, and conclude that these are structuralisomerides and that there is consequently no need for a specialstereochemical hypothesis to account for them.46 Formulae (I) and(11) are now proposed :Et2Sh HpKcJ; ~ <sEt2****c1Et,S SEt, . . . . C1(I.) a-Dichloride. (11.) p-Dichloride.The a-dichloride is less polar, being insoluble in water; the p-iso-meride is appreciably soluble in water, the solution being conducting.By the action of moist silver oxide, the p-dichloride yields a strongbase, Pt(SEt,*OH),, from which an oxalate and other salts areobtained.The a-dichloride, on the other hand, is slowly butcompletely decomposed by silver oxide.The tetrahedral configuration for the or-dichloride is supported byexperiments on the addition of halogens to these substances, theresults of which are regarded as definitely inconsistent with Werner'sformulation. By implication doubt is also cast on the nature of theisomerism of the platinosammines.On the other hand the problem why the ionisable chlorine in thep-dichloride (11) does not rapidly co-ordinate with the platinumatom to yield the or-isomeride (I) remains to be elucidated.Moreover, a review by T.M. Lowry4' of the results of X-rayinvestigations of crystals of complex compounds from this point ofview suggests that caution is necessary in accepting the new formulae.This author contends that the anions in the tetragonal crystals ofthe salt K,PtCl, are undoubtedly of planar configuration as com-pared with the tetrahedral anions in the cubic K,Zn(CN),.48 Con-sequently the planar configuration for other complexes of 4-co-ordinated platinum should not be regarded as improbable.In view of the Stereochemistry of the atom w-ordimted to a metal.44 Ann. Reports, 1927, 24, 104.46 Ibid., 1929, 26, 80; this vol., p. 150.47 Proc. C a d . Phil. SOC., 1929, ZS, 219; A., 1929, 629.4a R.G. Dickinson, J . Arner. Chem. SOC., 1922, 44, 774, 2404; A., 1922,J . , 1930, 349; A., 669.i, 632 ; 1923, ii, 26ORGANIC CHEMISTRY .-PART II. 165discovery of optically active complexes of the metals by A. Werner,and of the fact that the distinction between principal and auxiliaryvalencies has been abandoned for some time, the stereochemicalreality of the co-ordination bond might be regarded as obvious.Yet it is only in recent years that attention has been paid to thesteric environment of the aon-metallic atoms such as nitrogen andsulphur through which co-ordination to a metal takes place.J. Meisenheimer in 1924a9 obtained evidence of the existence oftwo optically active dias tereoisomerides of the sarc osinedie t hy lene -diaminecobalt salts (I) and accounted for their existence by thesupposition that in this case the nitrogen atom forms a second centreof dissymmetry in addition to the cobalt atom. It may be pointedout, incidentally, that if this explanation is correct the compound isan unusual one in another respect, for a hydrogen atom is attachedto nitrogen, whereas the optical resolution of compounds of the type[NHR1R2R3]X has not been observed.The stereochemistry of thenitrogen and sulphur atoms in certain complexes has also beendiscussed by H. Reihlex~.~~J . xzThe first case of optical activity solely due t o this cause has beendescribed recently by F. G. Mann.61 The complex (11) resistedresolution, but when the platinum was oxidised to the 6-co-ordinatedcondition the resulting complex was successfully separated with theaid of camphor-10-sulphonic acid and the salt (111) was obtainedhaving [M],,,, + 1110’.49 Annden, 1924,438,217 ; A,, 1924, i, 1036.60 Z.a w g . Chem., 1926,151, 71; Annalen, 1926,447,211; 448,312; A.,61 J., 1930,1746; A., 1404.1926, 467, 699, 888166 BENNETT AND CHAPMAN :The dissymmetry is here centred in the co-ordinated sulphur atomand arises from the non-planar distribution of its three bonds,which are disposed as in sulphonium salts and sulphoxides. Anexamination of some chelate complexes of the type of (IV) for thepresence of the expected pairs of diastereoisomerides (here cis andtrans with respect to the heterocyclic ring) was unsuccessful.52This corresponds with the failure of the resolution of the platinouscomplex (11) and may be attributed to the instability of the co-ordination bond, with consequent ready interconversion of theisomerides.Natural Products ,53Owing to pressure of space an account will be given under thisheading of three subjects only, namely, the chemistry of angustione,carotene, and santonin.Other topics are held over until next year,when it is hoped to deal with recent work on the sterols and bileacids.Angzlstione.-A naturally occurring p-diketone has been foundfor the first time in angustione from the essential oil of Backhousiaangustifolia. 54 The substance, which has the composition C,,H,,O,,shows an intense ferric chloride coloration, readily yields a copperderivative, and by the action of ammonia an amino-compound.The action of alcoholic potassium hydroxide at 150" causes fissioninto acetic acid and a diketone, C,H1,O,.This is of the substituteddihydroresorcinol class, yields my-trimethylglutaric acid on treat-ment with sodium hypobromite, and is therefore 1 : 1 : 3-trimethyl-cyclohexane-4 : 6-dione (I). The unsaturated compound (11),obtained by oxidation of (I) or of angustione with ferric chloride,is itself oxidised to dimethylmalonic acid and is converted byphosphorus trichloride into 4 : 6-dichloro-1 : 2 : 3-trimethylbenzene.55Thereis found with it a second diketonic substance, dehydroangustione(IV), which is transformed into the unsaturated diketone (11) by theaction of 50% sulphuric acid.This unusual structure for dehydro-angustione has been confirmed by its oxidation to acty-trimethyl-glutaconic acid 55a and a p-hydroxy-my-trimethylglutaric acid (V).m G. M. Bennett, A. N. Mosses, and F. S. Statham, J . , 1930, 1668; A . ,1432.63 Mention should have been made in the last Report (p. 146) of the im-portant addition to C. A. Kern's synthesis of norpinic acid made by C. W.Shoppee and J. L. Simonsen (Chem. and Ind., 1929, 48, 730), who convertedthe synthetic trane-acid into the cis-acid identical with that from pinene.64 A. R. Penfold, J. Proc. Roy. SOC. New South Walee, 1923, 57, 300; C. S.Gibson, A. R. Penfold, and J. L. Simonsen, J., 1930, 1184; A,, 1924, i, 1328;1930, 921.Angustione is therefore a triketone of the formula (111).5 5 Compare Ann.Reports, 1906, 3, 122. 66a Priva?e communicationORGAXIC CHEMISTRY.-PART II. 167These substances thus contain the “ionone” ring which hasrecently been found in carotene (see below). They possess a carbonskeleton which evidently is not a simple multiple of the isopreneunit, but the problem of their genesis is an interesting one and itmay perhaps be assumed that at least two molecules of isoprene areinvolved.HF/CO,HCO CH-0 C0,H CH*OH\ /( 3 5 3 2CO CO-H (IV.) (V.)Carotene and Lycopene.-Recent biochemical work in connexionwith vitamin4 56 having shown the importance of carotene, theelaboration of a formula for this substance by P. Karrer and hisassociates is of exceptional interest.Carotene is a yellow hydrocarbon, C40H56, found in the carrot andin the leaves and seeds of many plants ; it is the colouring matter ofbutter.The substance was isolated with chlorophyll from stingingnettles by R. Willstatter and W. Mieg in 1907.57 The isomericlycopene (which also gives the colour reaction for vitamin-A) wasobtained from tomatoes and rose hips.58 The latter hydrocarbonis aliphatic, for complete hydrogenation converts it into the paraffinC40H82.59 The formulaCMe,:CH*CH,.CH,.CMe:CH[CH:CH*CMe:CH],CH,*CH,*CMe:CHMewas proposed for lycopene 60 and received some justification fromoxidation experiments.m Ann. RepoTt8, 1929, M, 245; H. N. Green and E. Mellanby, Brit. J .Exp. Path., 1930, 11, 81.67 Anrtalen, 1907, 355, 1 ; A., 1907, i, 865.6 8 R.Willstiitter and H. H. Escher, 2. phy8i0l. Chem., 1910, 64, 52 ; H. H.6B P. Karrer and R. Widmer, Helv. Chim. Acta, 1928, 11, 751; A., 1928,60 P. Karrer and W. E. Bachmann, ibid., 1929, 12, 286; A., 1929, 669.Escher, Helv. Chim. Acta, 1928, 11, 762; A., 1910, i, 330; 1928, 1016.1016.P. Karrer, A. Helfenstein, and H. Wehrli, ibid., 1930, 13, 87; A., 333168 BENNETT AND CHAPMAN :Catalytic hydrogenation and other tests showed that the carotenemolecule contained eleven double bonds with three (or two) lessreactive than the others,61 the ultimate reduction product being ofcomposition C,,H7,. It is therefore dicyclic.The nature of one ring in carotene was indicated by the productionfrom it by the action of cold permanganate of a substance identicalwith ionone and yielding, like ionone, as-dimethylsuccinic acid onoxidation.62 It follows that the molecule contains the trimethyl-cyclohexene ring of ionone, and the partial formula (I) was adopted.,CH,-CMe, ,CH,-CMe,CH, >C[ CH : CH CMe : CHI qC 11 H 1, CH, \CO,H\CH2-CMe \CH,-COMe(1.1 (11.)In the latest memoir 63 the isolation of other oxidation products isdescribed, including geronic acid (11), confirming the presence of theionone ring.As the second ring of carotene, contained in the residueC11H17 in formula (I), is likely to have resulted from ring-closurein the lycopene molecule, this residue would (from the structure - -CH -CH assumed for lycopene) be of the form -CH:CH*CMe<cM~:CM~>cH2.But none of the expected oxidation products of such a ring isdetected, nor is carotene optically active as it would then pre-sumably be.A careful study of the proportions of acetic acidresulting from oxidation of lycopene and carotene with chromicacid moreover shows that each yields 6 mols. of acetic acid per mol.,whereas these formulse require 8 and 7 mols. respectively (one foreach C-CMe:C group).These difficulties are now surmounted by adopting the formula(111) and (IV) for the two hydrocarbons :EH[ CH:CMe*CH:CH],CH:CMe[CH,],CH:CMe,(111.) CH[CH:CMeCH:CH],CH:CMe[CH,I2CH:CMe,,CELyCMe, CMe,*CH,%€&ie UV. 1 \CMe-CH2C[CH:CH*CMe:CH],CH:CH[CH:CMe*CH:CH],d >CH2The second ring in (IV), being equally an ionone ring, gives rise tono other oxidation products.It is noticeable that the formula no longer represent products of6 1 R.Pummerer and L. Rebmann, Ber., 1928, 61, [B], 1099 ; W. Reindel,ibM., 1929, 62, [B], 1411; L. Zechmeister and others, ibid., 1928, 61, [B],666, 1634; 1929, 62, [B], 2232; A., 1928, 624, 766, 1016; 1929, 906, 1306.62 P. Karrer and A. Helfenstein, Hdv. Chim. Acta, 1929, 12, 1142; A,, 76.68 P. Karrer, A. Helfenstein, H. Wehrli, and A. Wettstein, ibid., 1930,13,1084 ; A., 1422ORGANIC CHEMISTRY.-PART II. 169continuous polymerisation of isoprene, but it is suggested that thelycopene carbon chain may arise by the union of two molecules ofphytol aldehyde. Phytol, the alcohol of chlorophyll, has recentlybeen identified as 3 : 7 : 11 : 15-tetramethyl-A2-hexadecen-1-01, theconstitution having been codrmed by a synthesis from +ionone.84The corresponding aldehyde,CHMe,[CH,],CHMe[CH,],CHMe[CH,],CMe:CH*CHO,by a benzoin condensation or a pinacol reduction would give therequired carbon chain and dehydrogenation would lead to lycopeneThis argument has led the authors to suggest a corresponding(111).alteration in the formula for ~ q u a l e n e , ~ ~ which would be{CMe,:CH[CH,],CMe:CH*CH,*CH,*CMe:CH*CH,~},.The ketone C19H,,0 obtained by oxidation of partlyreduced squaleneshould therefore be 2 : 6 : 10-trimethylhexadecan-15-one and notthe 3 : 7 : ll-isomeride.The former has been synthesised andappears to be identical with the ketone from squalene.8antonin.-This substance, which is the chief active constituentof wormseed, has long been known to be a lactone derived froma reduced naphthalene molecule.Its chemistry was developedparticularly by S. Cannizzaro and his pupils and the formula (I) wasgenerally accepted.Santonin is ketonic but is converted by concentrated hydrochloricacid into a phenol, desmotroposantonin, hitherto written as (11), anddrastic reduction yields santonous acid (111).Me CH,CH-CHM HO(~$Ef-CHMeyo $JyJ CH-aco Y5tCH; Me 0Me CH, (I.)The question of the constitution of santonin has been reopenedby G. R. Clemo, R. D. Haworth, and E. Walton,66 who consideredthat the conversion into desmotroposantonin could not be merelya keto-enolic change, and that the santonin skeleton would moreprobably be such as could be derived by the union of isoprene units.The structure (IV) was suggested as meeting these and other points-in particular the observations of A.Angeli and L. mar in^,^^ whoobtained by oxidation a heptanetetracarboxylic acid, apparentlypossessing a quaternary carbon atom, to which formula (XX) may64 F. H. Fischer and K. Lowenberg, Annalen, 1928, 464, 69; 1929, 476,183; A., 1928, 989; 1929, 1421.66 J., 1929,2368; 1930,1110,2679; A., 1929,1464; 1930,919.67 Atti R. Accad. Lincei, 1907, 16, i, 159; Mem. A d . Lincei, 1908, 6,6s Ann. Reports, 1929,26, 90.386 ; A., 1907, i, 321 ; 1908, i, 643.F 170 ORGANIC CHEMISTRY.-PART 11.be assigned. The change to desmotroposantonin must on this viewinvolve the migration of a methyl group-for which, however, thereMe CH, CO,H C0,HHOTy&*CHMe*CO,H 70,H qH-CHMe \ IH02dfhH,/cH2\/\/Me CH,(111.) Me (XX.)is a close analogy in the conversion of 2 : 4-dimethylchinol (V) into2 : 5-dimethylquinol (VI).68CMe CH, Me MeHO/\ 11 IOH\/Me (IV.) (V.1 (VI-)MeMe06co/CH:CH*C02H M e 0 6 yH-1 (p2Et\CO*CH,Me (VII.) Me (VIII.)The position of the a-propionic acid side-chain was first fixed by asynthesis of santonous acid. Condensation of p-xylyl methyl etherwith maleic anhydride in presence of aluminium chloride gave theunsaturated acid (VII), which was converted by hydrogen chlorideand ethyl alcohol into the ester (VIII). The latter by couplingwith diethyl methylmalonate and hydrolysis yielded a mixture ofstereoisomeric acids (IX), which were reduced by Clemmensen’smethod to two acids of structure (X).The action of sulphuric acidcaused ring closure, and the product (XI) (obtained in an enol-lactonic form) by further reduction furnished dl-santonous acidmethyl ether, which was demethylated to the acid itself (111).MeO/) Me yH-CHMe*CO,H YO,H Me06,d!r FH--CHMe*CO,HbyCH. Me 0 Me H,(IX.) (X-)6* E. Bamberger and F. Brady, Ber., 1900,33,3642 ; A., 1901, i, 142ORGANIC CHEMISTRY.-PART m. 171This confirmed the accepted formula, for santonous acid, and thatfor desmotroposantonin was next proved by synthesis. One of theacids (X) yielded, when heated with hydriodic acid, the enol-lactone(XII), and sodium amalgam reduced this to desmotroposantonin(XIII). This formula differs from (11) only in the position of thelactone ring.Such an oblique arrangement of rings had beensuggested by S. Cannizzaro.69 It entails a readjustment of thesantonin formula to (XIV).Evidence was still needed of the position of the methyl groupregarded as migrating, and it was obtained as follows. Tetra-hydrosantonin, resulting from catalytic hydrogenation, was reducedby Clemmensen’s method to the fully saturated lactone, from whichby the action of selenium a hydrocarbon was formed which provedto be l-methyl-7-ethylnaphthalene ‘0 (XV).’O--T0 CH-CHMe f\/\\F,t IMe CH Me Me CH QqQH2 \A/HO,(~@~CX&CHMe ’T\./ \/Me CH,(XIII.) Me (XIV.) F V - 1The formula (XIV) for santonin has been accepted by L.R~zicka,~l who announced the degradation to l-methyl-7-ethyl-naphthalene a little before the other authors.Santonin is thus placed in the eudesmol (selinene) group 72 ofterpene compounds.G.M. BENNETT.A. W. CHAPMAN.PART III.-HETEROCYCLIC DIVISION.Oxygen Ring Compounds.AN account was given in last year’s Report of the preparation ofvarious flavones, flavonols, etc., by the acylation of o-hydroxy-acetophenone derivatives. This process has now been furtherapplied by A. Lovecy, R. Robinson, and S. Sugasawa2 to thesynthesis of luteolin 3’- and 4’-methyl ether (I and I1 respectively)by acting upon phloracetophenone with sodium O-benzylvanillateBer., 1893, 26, 786; A., 1893, i, 364.70 J. Harvey, I. M. Heilbron, and D. G. Wilkinson, J., 1930, 423; A., 593.L. Ruzicka and E. Eichenberger, Helv. Chim. Acta, 1930,13, 1117; A.,Ann. Reports, 1923, 20, 100; 1924, 21, 103.Ann.Reports, 1929, €36, 162.1442.a J., 1930, 817172 W T :and O-benzylvanillic anhydride, on the one hand, and sodiumO-benzylisovanillate and O-benzylisovanillic anhydride on theother, followed by the hydrolysis of the primary products in each0 OMe 0 OHcase. The latter flavone (11) was found to be identical with dios-metin, the rhamnoglucoside of which is diosmin, recently isolatedby 0. A. Oesterle and G. Wander.3 An examination of the reactionsof primetin, from PrimuZa modesta, has led W. Nagai and S. Hattori *to the conclusion that it is 5 : 6-dihydroxyflavone (111). Thepresence of an unsubstituted 2-phenyl group is indicated by theformation of benzoic acid on alkali fission, and the vicinal characterof the two hydroxyl groups is suggested by a green coloration withferric chloride and the readiness with which oxidation can occur.Primetin can give a diacetyl derivative, but methylation withdiazomethane or methyl iodide and alkali leads to a monomethylether, which gives a violet-brown colour with ferric chloride andcan be acetylated.The formula (111) for primetin is further supportedby an investigation of the absorption spectrum.c1F%H o e s HodzaoH HO CO (111.) RO (IV.)Some of the earlier syntheses of well-known anthocyanidinsthrough their methyl ethers have proved to be unsatisfactory, sincethe subsequent demethylation process led to impure products, andin more recent times they have been replaced in certain cases bymuch improved methods which avoid demethylation.These laterreactions have now been applied by W. Bradley, R. Robinson, andG. Schwarzenbach 6 to the preparation of delphinidin chloride(IV ; R = H). The interaction of 2-O-benzoylphloroglucinaldehydeH O P CHO A c t 6 AcO CO*CH,*OAc Ph2c<:o CO*CH,*OAcOBz Me0(V. ) W.) (VII.)8 Helv. Chim. Acta, 1926, 8, 619.ti See Ann. Reports, 1928,25, 163.Acta Phytochim., 1930, 5, 1; A., 704.J., 1930, 793ORGANIC CHEMISTRY.-PART III. 173(V) and w : 3 : 4 : 5-tetra-acetoxyacetophenone (VI) by means ofhydrogen chloride in alcohol-ethyl acetate yielded 5-O-benzoyl-delphinidin chloride (IV ; R = Bz), the acetyl groups being removedduring the reaction. Hydrolysis with aqueous-alcoholic sodiumhydroxide and subsequent t’reatment with hydrochloric acid thenc1m-\ ;~Qo~cH~~oA~ HO dzQp OMe M e O PCHOMe0 HO OH(VIII.) (X.1gave a product which was identical with delphinidin chloride fromnatural sources.A similar series of reactions with (V) and either(VII) or (VIII) led ultimately to 3’-O-methyldelphinidin chloride(IX), which very closely resembled natural petunidin chloride,although complete identity was not established, possibly owing tothe disturbing effects of traces of impurity in the natural product.The same authors have condensed 2-Q-benzoyl-4-O-methylphloro-glucinaldehyde (X) with w-acetoxy-4-benzyloxy-3 : Ei-dimethoxy-acetophenone (XI) by an analogous process, and, after hydrolysisof the resulting 5-O-benzoyl derivative, 7 : 3’ : 5’-O-trimethyl-OMec10 OMe r4delphinidin chloride (XII) was obtained.This substance proved tobe identical with llirsutidin chloride, recently isolated from Primulahirsuta,’ so that the structure of this anthocyanidin is now definitelyestablished.One of the most interesting problems associated with the naturallyoccurring oxygen ring compounds is the interconversion of thevarious types. Several processes of this nature have alreadyreceived considerable attention,8 and R. Robinson and G. Schwar-zenbachg have now made a study of the conversion of flavyliumsalts into flavones. Although this change is reminiscent of thefacile transformation of an alkylpyridinium salt to a pyridone, nosuccessful general procedure has hitherto been developed for it.7 P.Karrer and R. Widmer, Helv. Chim. Acta, 1927,10, 758.* See Ann. Repor& 1928,25, 169. 9 J., 1930,822174 PLANT :7-Hydroxy-4-carboxyflavylium betaine (XIII) has been oxidisedto 7-hydroxyflavone (XIV) by the use of chromic acid in acetic acid(XIII.) (XIV.) (XV.1solution,1° but the method cannot be applied in general to related4-carboxyflavylium salts or the corresponding betaines. It hasbeen found, however, that scutellarein tetramethyl ether (XV) canbe synthesised by an application of the Hofmann reaction to theappropriate acid amide of this type. The 4-carbamyl-5 : 6 : 7 : 4'-tetramethoxyflavylium chloride (XVI) resulting from the interactionof anisoylpyruvamide (XVII) , antiarol (3 : 4 : 5-trimethoxyphenol) ,and hydrogen chloride was submitted to a Hofmann reaction andyielded a pseudo-base (XVIII) which was subsequently convertedinto the tetramethoxyflavone (XV) by treatment with boilingdilute aqueous sodium hydroxide.The authors point out that, ifan easily accessible route can be found for the preparation of thearoylpyruvamides, this might become a valuable method for thesynthesis of flavones. The precedifig preparation of scutellareintetramethyl ether is of added interest in view of the fact that theearlier synthesis of this flavone by G. Bargellini l1 involved a processwhich was not quite unambiguous. An alternative synthesis hasmore recently been described by F. Wessely and G. H. Moser.12The action of anisic anhydride and potassium anisate on 2 : 4-di-hydroxy-3 : 6-dimethoxyacetophenone (XIX) at 180-185", followedM e O @ - ~ O M e Ho(JL CO*CH,OMe PH Me0Me0 C:NH(XVIII.) (XIX.)lo C.Biilow and H. Wagner, Ber., 1903, 36, 1941.l1 Gazzetta, 1915, 45, 69. l2 Monatsh., 1930, 56, 97; A., 1295ORGANIC CHEMISTRY.-PART III. 175by hydrolysis of the primary product, resulted in the unexpectedformation of 5 : 7-dihydroxy-6 : 4’-dimethoxyflavone (XX), whichinvolved partial demethylation. The tetra-acetate of the5 : 6 : 7 : 4’-tetrahydroxyflavone obtained by the demethylation ofthe latter product proved to be identical with scutellarein tetra-acetate.There now appears to be some doubt whether the reduction offlavonols in acid solution can actually lead to anthocyanidins aspreviously believed.13 The product obtained from quercetin (XXI ;R = H), although it closely resembles cyanidin chloride, is regardedby T.Malkin and M. Nierenstein14 as having the constitution(XXII), and an analogous structure is assigned to the product ofthe reduction of rhamnetin (XXI; R = Me).n OHHO CO (XXI.)c10 OH rc?It was mentioned in last year’s Report l5 that +baptigenin hadbeen recognised as an isoflavone of the formula (XXIII). Theconstitution assigned to this product has now been confirmedsynthetically in two ways by E. Spath and E. Lederer.16 In thefirst route, the crude cyanohydrin of the substance (XXIV), whichwas obtained by condensing resorcinol and w-bromoacetopiperonein the presence of sodium hydroxide, was submitted to a Hoesch(XXIV.) (XXV.)13 R.Willstiitter and H. Mallison, Sitzungsber. K. Akad. Wiss. Berlin, 1914,l4 J . Amer. Chem. SOC., 1930, 52, 2864; A., 1189.l6 Ann, Reports, 1929,26, 156.769; A., 1914, i, 1081; A. Robertson and R. Robinson, J . , 1927, 2196.l6 Ber., 1930, 63, [B], 743; A , , 611176 PLANT :reaction, and the product, which undoubtedly contained the com-pound (XXV), was subsequently sublimed in a vacuum. Besidesthe unchanged ketone (XXIV), $-baptigenin, identical with thesubstance from natural sources, was obtained in this way. In thesecond method, $- baptigenetin (XXVI) , previously synthesisedfrom resorcinol and 3 : 4-methylenedioxyphenylacetonitrile by aHoesch reaction, was treated with ethyl formate and sodium, andthe product (XXVII) was heated with alcohol and fuming hydro-chloric acid ; after subsequent sublimation, $-baptigenin was againisolated.(XXVI.) (XXVII.)Using synthetical processes already well known in the chalkoneand flavanone series,17 J. Shinoda, S. Sato, and M. Kawagoe l8have prepared butein (XXVIII) by first condensing resorcinol and3 : 4-diethylcarbonatocinnamoyl chloride in nitrobenzene in thepresence of aluminium chloride, and then heating the product withaqueous potassium hydroxide. On treatment with boiling alcoholichydrochloric acid, butein was converted into the correspondingflavanone, butin (XXIX).OH 0 OH HOP . OH H O ~ ~ Z - ~ O W C H , CO*CH.CH(XXVIII.) co (XXIX.)Considerable attention has recently been directed towards theposition of the sugar residue in certain well-known glucosides.Thewidely occurring product phloridzin yields phloretin and glucose onhydrolysis, but, although the structure of phloretin has long beenestablished and it has been known that the glucose residue is attachedto the phloroglucinol nucleus, its exact location has been uncertain, y)&.H yyH CO R*H Meo()ggR*MeOH OH OMe(1.1 (11.) (111.)(X = C,HllO, ; R = *CH,*CH,C,H,*O*)See, e.g., J. Shinoda and S. Sato, J . Pharrn. SOC. Japan, 1928, 48, 109;Ann. Reports, 1928, 25, 169.l8 J . Pharm. SOC. Japan, 1929,49, 123; A., 1930, 93ORGANIC CHEMISTRY .-PBRT 111. 177the formula? (I) and (11) both being possible. This point has nowbeen settled by an examination of the product obtained by hydrolys-ing the fully methylated gluc0side.1~ This product must have thestructure (111), since, on heating with acetic anhydride and sodiumacetate, acetylation is accompanied by ring closure to give a sub-stance which is either a coumarin (Tv) or a chromone (V), a processwhich is dependent upon the presence of a free hydroxyl group inthe 2-position with respect to the carbonyl group.Furthermore,the compound (111) has also been prepared by the catalytic hydro-genation of 2-hydroxy-4 : 6-dimethoxyphenyl p-methoxystyrylketone. Phloridzin, therefore, has the constitution (I). Previousexperience with analogous reactions indicates that the acylationproduct of the substance (111) is almost certainly the chromone (V),and this has recently been codkmed by J.Shinoda and T. Sato 2ofrom a study of the chemical behaviour of the compound.The glucoside obtained from p-acetobromoglucose anddaphnetin21 (VI) has been shown to have the glucose residue inthe 8-position,22 and S. Hattori23 has now proved that it is notidentical with daphnin, the naturally occurring glucoside ofdaphnetin. Furthermore, the methyldaphnetin obtained from thesynthetic glucoside by methylation and subsequent hydrolysis wasfound to be different from the methyldaphnetin obtained by asimilar process from d a ~ h n i n . ~ ~ It follows that dnphnin must havethe glucose residue in the 7-position.HO 0 HO 0 0(VI.1 (VII.) (VIII.)19 F. Wessely and K. Sturm, Monatsh., 1929, 53 and 54, 554; A., 1929,1452; F. R. Johnson end A.Robertson, J., 1930, 21.2o J . Pharrn. SOC. Japan, 1930, 50, 32; Chem. Zentr., 1930, ii, 404.a1 P. Leone, Gazzetta, 1925, 55, 674; A., 1926, 75.2a F. Wessely and I(. Sturm, Ber., 1929, 62, [B], 115; A., 1929, 298.98 J . Pharrn. Soc. Japan, 1930, 50, 82.24 See also F, Wessely and K. Sturm, Ber., 1930, 68, [B], 1299178 PLANT :Fraxin, the naturally occurring glucoside of fraxetin (VII), hasbeen shown by F. Wessely and E. Demmer 25 from a series of alkyl-ation experiments to have the glucose residue in the 8-position,for it is converted by successive methylation, hydrolysis, andethylation into 6 : 7-dimethoxy-8-ethoxycoumarin, identical withthe product obtained from 7-methoxy-8-ethoxycoumarin byoxidation 26 and subsequent methylation.Although it has long been known that mculin yields glucose andaesculetin on hydrolysis, and that the latter is 6 : 7-dihydroxy-coumarin (VIII; R = H), the exact location of the glucose residuehas again hitherto remained uncertain.F. S. H. Head and A.Robertson 27 have now shown that the glucosidoxy-group is in the6-position (VIII ; R = C,HI10,). By successive methylation,hydrolysis, and ethylation, the glucoside yielded a methoxyethoxy-coumarin, which was converted into the methyl ester of 2 : 4-di-methoxy-5-ethoxycinnamic acid by the subsequent action of methylsulphate and sodium hydroxide. The structure of the acid derivedfrom this ester on hydrolysis was confirmed by synthesis.Mention may be made of several interesting observations in thechemistry of other oxygen ring compounds not directly related tonatural products.An investigation by R. E. Lutz 28 into thereduction products of several unsaturated 1 : 4-diketones containingthe group O:C*C:C*C:O has shown that they may consist of thecorresponding saturated diketone, the corresponding furan deriv-ative, or a mixture of these two, according to the conditionsemployed. The fact that the saturated 1 : 4-diketones are them-selves unchanged by the conditions which lead to the furans suggeststhat the course of the formation of the furan ring involves first1 : 6-addition of hydrogen to give the group HO*C:C*C:C-OH, fol-lowed by the elimination of water.An interesting isomeric change has been brought to light byT. Rei~hstein,~~ who has shown that the action of aqueous potassiumcyanide on 2-chloromethylfuran leads essentially to 5-cyano-2-methylfuran (I), only a small quantity of the corresponding 2-cyano-methylfuran (11) being formed. Hydrolysis of the mixed cyanidesgave the analogous 2-methylfuran-5-carboxylic acid and furan-2-acetic acid.Zb Ber., 1929, 62, [ B ] , 120; A., 1929, 298.2 6 Compare G.Bargellini, Guzzettu, 1916, 46, 249; A., 1916, i, 489.2' J., 1930, 2434.t8 J . Amer. Chern. SOC., 1929,51,3008; A., 1929, 1459.28 Ber., 1930, 63, [B], 749; A., 611; see also M. M. Runde, E. W. Scott,and J. R. Johnson, J . Arner. Chern. SOC., 1930, 62, 1284; A., 783ORaANIC CHEMISTRY.-PART III. 179T. Reichstein30 has also made a detailed study of the ease withwhich well-known aldehyde and ketone syntheses proceed in thefuran series. Furfuraldehyde was obtained from furan by theaction of anhydrous hydrocyanic acid and hydrogen chloride inether at -15" without any additional condensing agent, the mixturebeing subsequently warmed to room temperature and the productEH-GH\/CH C*CH,*OMe RH-GH CH C*CH,.CN R H - Pv CNG CMe0 Y 0Ydecomposed with water.Similar experimental conditions resultedin the introduction of the a-aldehydo-group into several 2-alkyl-furans, but the procedure failed when applied to 2-acetylfuran, ethylpyromucate, coumarone, furfuryl methyl ether (111), and difurfurylether. These coiiditions also constituted a satisfactory method forthe conversion of 1-alkylpyrroles into the corresponding l-alkyl-pyrrole-%aldehydes, but failed in the case of pyrrole itself, 2-acetyl-pyrrole, and pyrrole-2-carboxylic acid.The method also could notbe applied to the preparation of thiophen-2-aldehyde, although thiscould be accomplished when an additional condensing agent waspresent, as, for example, when a mixture of thiophen, anhydroushydrocyanic acid, and benzene was treated with aluminium chlorideand hydrogen chloride. The 2-acetyl derivative of furan wasprepared by the interaction of furan and acetyl chloride in benzeneat 0' in the presence of stannic chloride ; 2-acetyl-5-methylfuran alsowas obtained under similar conditions, but a better yield resultedfrom the use of zinc chloride and ether. The author has discussedthe applicability of these experimental conditions and of thosepreviously described by other workers in this field.It has been observed that 7-hydroxy-2 : 3-diphenylbenzo-y-pyrone (IV) and some closely related derivatives dissolve in hotaqueous alkaline solutions and give gels on cooling, but only smallchanges in the nature of the substituents can be made withoutdestroying this chara~teristic.~1 Owing to the possible value of afluorescent gel-forming substance in the examination of the structureof gels, W.Baker 32 has prepared 10-hydroxyphenanthraxanthone(V), which, although closely related to (IV), contains a phenanthrenenucleus and so might be expected to exhibit fluorescence. Theso Helv. Chim. Acta, 1930, 13, 345, 349, 356; A., 783, 787.W. Baker and R.Robinson, J., 1925, 127,1981; W. Baker and (Miss)F. M. Eastwood, J . , 1929, 2897.52 J., 1930, 261180 PLANT :preparation was accomplished by an application of Pschorr's phen-anthrene synthesis to the methyl ether of 7-hydroxy-3-phenyl-2-o-nitrophenylbenzo-y-pyrone (VI), but the product gave a gelwhich showed no marked fluorescence and was not particularlystable.Xulphur and Selenium Ring Compounds.The configurations of the two stereoisomeric forms of 2 : 6-di-phenylpenthian-4-one (I), isolated by F. Arndt, P. Nachtwey, andJ. P u s c ~ , ~ ~ have now been established by F. Arndt and E. Scha~der.~*The modification (A), m. p. 113-114", must be the cis-, since itgave two varieties of 2 : 6-diphenyl-4-methylpenthian-4-01 (11) ontreatment with magnesium methyl bromide.These latter wereco MeC-OH CH2/\QHz p 2A5 3 3 2 p 3 2A7H2 Q H 2PhCH CHPh Ph*CH CHPh PhCH CHPh\/ S v S v S(1.) (11.) (111.)dehydrated to the same 2 : 6-diphenyl-4-methyl-A3-penthiene (or2 : 6-diphenyl-4-methylenepenthian). The modification (B), m. p.87-88", on similar treatment, gave first an amorphous product andthen an isomeric diphenylmethylpenthiene. The two forms of (I)have been reduced by amalgamated zinc and hydrochloric acid tothe corresponding cis- and trans-modifications of 2 : 6-diphenyl-penthian (111). Penthian-4-one itself has been prepared by G. M.Bennett and L. V. D. Scorah 35 by the application of a Dieckmannreaction to ethyl p- thiodipropionate, S (CH,*CH,-CO,Et), , andhydrolysis of the resulting ester.Other interesting sulphur-containing rings are found in 1 : 3-di-thiolan (IV ; n = 2) and 1 : 3-dithian (IV ; n = 3).D. T. Gibson 36has described the preparation of the former, by distilling a mixtureof formaldehyde, sodium ethylene thiosulphate, and hydrochloric33 Ber., 1925, 58, [B], 1633; A., 1926, i, 1307.34 Ibid., 1930, 68, [ B ] , 313; A,, 612. 35 J., 1927, 194. 36 J . , 1930, 12ORGCBNIC C€CEMISTRY.-PART IlX. 181acid, and of the latter from trimethylene dibromide, sodium thio-sulphate, formaldehyde, and hydrochloric acid.(IV.) (VI.)In addition to cycloselenobutane and cycloselenopentane, men-tioned in last year's ReportY3' G. T. Morgan and F. H. Burstal138have now described the preparation of cycloselenopropane (V ;n = 1) and cycloselenohexane (V; n = 4) in small yield by theinteraction of sodium selenide with trimethylene dibromide andhexame th ylene di bromide re spec tively .These sub stances are notonly more difficult to prepare than their analogues, but they are alsocharacterised by a greater degree of instability and a tendency topolymerise. In fact, the main product formed during the prepar-ation of the former compound is a six-fold polymeride, and cyclo-selenohexane also is accompanied by a dimeride and a complexpolymeride. The new monomeric cyclic selenium compounds showthe property, common to those previously described, of combiningadditively with such reagents as the halogens and mercuric chloride.By an extension of other reactions used in the earlier work, hexa-methylene dibromide has been converted by the action of potassiumselenocyanate into hexamethylene diselenocyanate (VI), which wastransformed into cyclohexamethylene 1 : 8-diselenide (VII) ontreatment with alcoholic alkali. The latter decomposed, whenheated, to give 2-methylcycloselenopentane (VIII) .C€&*CH,*CH,*Se CH2*CHMe CH,*CH*CO,HCH2*CH2-CH2*ke I C.2< c)se CH, I ,c)."" HC0,H(IX.)CH2* -H2(VII.) (VIII .)A. Fredga 39 has prepared cis-tetrahydroselenophen-2 : 5-dicarb-oxylic acid (IX) by the action of potassium diselenide on sodiummeso-aa'dibromoadipate, and the corresponding trans-modificationby the action of potassium selenide on sodium dl-ad-dibromo-adipate. The trans-form, as expected, was found to be resolvableby brucine. Also of interest is the preparation by C.S. Gibson andCH2*CH, J. D. A. Johnson of 1 : 4-selenoxanY qCH eCH >Se, by the2 2action of sodium selenide on pp'-dichlorodiethyl -ether ; *O thissubstance, like those mentioned above, readily forms additionproducts.31 Ann. Reports, 1929, 26, 160.'0 J., 1931,266.38 J., 1930, 1497.J . pr. Chem., 1930, [ii], 127, 103; A,, 1196182 PLANT :Indole Derivatives.Some interesting observations in the isatin group have beenrecorded by J. M. Gulland, R. Robinson, J. Scott, and S. Thornley.*l5 : 6-Methylenedioxyisatin (I) undergoes ring fission, when treatedwith nitric acid, to give ox-6-nitro-3 : 4-methylenedioxyanilic acid(11). A similar reaction has been previously observed42 betweennitric acid and di(methy1enedioxy)indigotin. A new route for theproduction of isatin derivatives is found in the prolonged hydrolysis,with boiling dilute aqueous-alcoholic sodium hydroxide, of theazlactone (111) derived from the interaction of 2-nitroveratraldehydeand hippuric acid.The formation of 6 : 7-dimethoxyisatin in thisway provides another example of an interesting type of intra-molecular oxidation-reduction.S. G. P. Plant 43 has prepared 9-methyl- and 9-ethyl-1 : 2 : 3 : 4 : 5 : 6 : 7 : 8-octahydrocarbazole (IV) by the action ofthe appropriate alkylamines on 2 : 2'-diketodicycbhexyl (V) inglacial acetic acid. These substances proved to be identical withcompounds obtained by J. von Braun and H. Ritter44 by thecatalytic hydrogenation of the corresponding 9-alkylcarbazoles, anddifferent from the alkylation products of the base obtained by theremoval of ammonia from cyclohexylideneazinc 45 (VI).The lastreaction, which is reminiscent of the preparation of tetraphenyl-pyrrole from phenyl benzyl k e t a ~ i n e , ~ ~ does not, therefore, yield(IV; R = H), but an isomeric ocfahydrocarbazole, probably ofthe structure (VII).42 T. G. Jones and R. Robinson, J., 1917, 111, 908. 41 J . , 1929, 2924.43 J., 1930, 1595.45 W. H. Perkin and S. G. P. Plant, J., 1924, 125, 1603.4~3 (Mrs.) G. M. Robinson and R. Robinson, J., 1918,118, 639.44 Ber., 1922, 55, [B], 3792ORGANIC CHEMISTRY.-PART III. 183The system of nomenclature and numbering hitherto employedfor the various carbolines has been anomalous and unsatisfactory.It has now been suggested:' in consequence, that 3-, 4-, 5-, and6-carboline should be re-named a-, p-, y-, and 8-carboline respectively,and that the accompanying numbering (formula VIII ; p-carbolinebeing used for illustration), which is more conventional, should beapplied to all the four groups. In some recent papers these proposalshave been adopted.The reaction previously observed by R. H. F.H HManske and R. Robinson4* in which the decomposition of theazide (IX) of (3-3-indolylpropionic mid by hydrogen chloride inbenzene is accompanied by intramolecular condensation with theformation of 2-keto-2 : 3 : 4 : 5-tetrahydro-p-carboline (X; R = H)has now been applied to the preparation of 2-keto-7-methoxy- and4 2 - CON,NH.CH.,, CH,(IX.) (X-) (XI.12-keto-8-methoxy-tetrahydro-~-carboline.49 The latter (X ; R =MeO) was found to be identical with one of the substances obtainedby the hydrolysis of the product of the oxidation (by permanganate)of acetylharmaline, and conbation is consequently provided forthe constitution (XI) assigned to acetylharmaline.wAlthough the structures of harman, harmalipe, and harmine havebeen already amply confirmed by synthesis, 51 additional methodsdeveloped by E. Sprith and E. Lederer 52 are of interest, and areclosely related to well-known reactions in the isoquinoline series.The acetyl derivative of 3- p-aminoethylindole has been convertedby phosphoric oxide in boiling xylene into dihydroharman, whichwas subsequently dehydrogenated with spongy palladium a t 200"to give harman (XII).A similar process applied to 6-methoxy-3- (3-acetamidoethylindole led first to harmaline (XIII) and then to47 J. M. Gulland, R. Robinson, J. Scott, and S. Thornley, Eoc. cit.*@ IT. S. B. Barrett, (the late) W. H. Perkin, and R. Robinson, J., 1929,2942.6o H. Nishikawrt, W. H. Perkin, and R. Robinson, J., 1924,125, 657.61 See, e-g., Ann. Reports, 1927, 24, 160.63 Ber., 1930, 63, [B], 120; A,, 363.J., 1927, 240; Ann. Reports, 1927, 24, 161184 PLANT :harmine (XIV). The same authors 53 have extended these reactionsto other acyl derivatives of 3-P-aminoethylindole and certain of itssubstitution products for the purpose of preparing a large number ofp-carbolines.They have also investigated the condensation of(XII.) (XIII.) (XIV.)formaldehyde with some 3-p-aminoethylindoles, and the dehydro-genation of the resulting 2 : 3 : 4 : 5-tetrahydro-p-carbolines top-carbolines by palladium at 160-170". Further reactions of asimilar type have been studied by S. Akabori and K. S a i t ~ . ~ ~Tetrahydroharman (XV) was prepared by the condensation of3-p-aminoethylindole with a~etaldehyde,~~ and was dehydrogenatedto harman on being boiled in aqueous solution with maleic acid andpalladium-black for five hours ; an analogous procedure resulted inthe conversion of 6-methoxy-3-~-aminoethylindole into harmine.This method of dehydrogenation, which involves the catalytic trans-ference of hydrogen to an unsaturated compound, is of considerableinterest, and has been applied by S.Akabori and his co-workers 56to a number of other products, several different unsaturatedsubstances being used.Me(XV.) (XVI.) (XVII. )By reactions analogous to those which have been used for thesynthesis of y-~arboline,~~ W. 0. Kermack and J. F. Smith 68 haveobtained derivatives of 2 : 3-benz-y-carboline (XVI). For example,4-o-aminophenylamino-2-methylquinoline, from the interaction of4-chloro-2-methylquinoline and o-phenylenediamine, was convertedinto a triazole derivative (XVII), which subsequently gave 5-methyl-63 Ber., 1930, 63, [ B ] , 2102. 64 Ibid., p. 2245.66 Compare G. Trttsui, J . Pharm. SOC. Japan, 1928, 48, 92.Proc. Imp. Acad. Tokyo, 1929, 5, 255; 1930, 6, 236; A., 1929, 1170;R.Robinson and S. Thornley, J., 1924,125, 2169.1930, 1192.68 J., 1930, 1999ORGANIC CHEMIS!I’RY.-PBRT III. 1852 : 3-benz-y-carboline by loss of nitrogen, on heating in syrupyphosphoric acid. The same authors have also prepared 1 : 54%-methyl-2 : 3-benz-y-carboline by treating o-acetamidoacetophenonephenylmethylhydrazone (XVIII) with phosphoryl chloride in boilingtoluene. The methosulphate of this carboline is apparentlyidentical with the methosulphate of the anhydronium base (XIX)derived from the action of alkali on the methosulphate of &methyl-2 : 3-benz-y-carboline. This fact, together with the fluorescentproperties of these carbolines, confirms the structures assigned tothem. The anhydronium base (XIX) is analogous to theanhydronium bases derived from certain p-ca;rboline~,~g and itspreparation has an added interest in view of the behaviour of otherclosely rela%ed substances.Thus (Mrs.) G. M. Robinson 6O hasprepared 2 : 3-pyrrolo(4‘ : 5’)-quinolines (XX) by the dehydrationof 3-acylamidoquinaldines (XXI), a n extension of a reaction pre-viously used in the pyrindole series,61 and has found that the metho-sulphate of 2 : 3-(2’-phenylpyrrolo)(4‘ : 5’)-quinoline (XX; R = Ph)Me NHreadily yields an anhydronium base (XXII) with aqueous sodiumhydroxide. It has been noted, however, that quindoline metho-sulphate (XXIII) gives no analogous anhydronium base.62N NH-wS0,Me(=I*) (=I*) (XXIII.)Mentian may be made in this section of an interesting applicationof Fischer’s indole synthesis to the phenylhydrezone of penthian-A S &(XXIV.) p z p% CH, (XXV.1 CH, CH, NR CH,(* J., 1929, 2948.b6See Ann.Reports, 1928, 25, 176.61 E. Koenigs and A. Fulde, Ber., 1927, 60, [B], 2106. ‘* J. W. Armit and R. Robinson, J., 1922, 121, 827186 PLAXT :4-one (XXIV), which resulted in the formation of penthienoindoleQuinoline Derivatives.(XXV).Further interesting developments in the chemistry of the cyaninedyes have recently been recorded. With a view to the study ofsome physical properties, Miss F. M. Hamer 64 has investigated thepossibility of preparing examples of known classes of these dyes fromcertain more complex compounds of the quinaldine or lepidine type ,containing a reactive methyl group.From the interaction of themethiodide of 2-methylacenaphthppidine (I) and the quinolinealkyliodides, isocyanines of the formula (11) resulted, and, with the2-iodoquinoline alkyliodides, +cyanines of the constitution (111)(1.1 (11.) R"-Iwere obtained by the usual methods, but attempts to prepare acarbocyanine from it by the well-known procedure with ethyl ortho-formate and pyridine were unsuccessful. Although &methyl-acridine (IV) contains a reactive methyl group, attempts to preparea carbocyanine from its methiodide or to effect condensation withquinoline methiodide by the usual methods met with failure. How-ever, from the condensation of 5-methylacridine methiodide with2-iodoquinoline alkyliodides in aqueous potassium hydroxide dyeswere obtained to which the formula (V) has been attributed, buttheir physical properties were somewhat abnormal.An interesting and surprising new route for the production ofthiocyanines, which in several respects is superior to the older6s G.M. Bennett and W. B. Waddington, J., 1929, 2829. 64 J., 1930, 995ORGANIC CHEMISTRY.-PART III. 187methods, has been discovered by Miss N. I. Fisher and Miss F. M.Hamer.65 The process came to light during an attempt to applythe reaction by which 2-methylene-1 : 3 : 3-trialkylindolines (VI),or the corresponding indoleninium salts (VII), are converted intodyes of the type (VIII; A := CR,) 66 to the preparation of thecorresponding sulphur compounds (VIII; A = S). The action ofamyl nitrite, in the presence of acetic anhydride, on the alkylchloridesof 1 -methylbenzthiazole (IX) led unexpectedly to the thiocyanines(X). The course of this reaction is not obvious, although theauthors have put forward tentative suggestions.It is well knownthat it is very difficult to prepare cyanine and carbocyanine dyes(VIII. )(X.1from monocyclic compounds, although certain carbopyridine-cyanines have recently been prepared.67 It is not surprising,therefore, that the new method for the preparation of thiocyaninesfails when applied to the alkylchlorides of 2 : 4dimethylthiazole(XI). Our knowledge of the simpler types has, however, beenextended by these authors by the preparation of thiocarbocyaninesof the formula (XII) from the action of ethyl orthoformate andpyridine on the 2 : 4-dimethylthiazole alkyliodides.Some interesting observations have been made by G.R. Clemoand H. J. Johnson G8 during the course of experiments designed forthe purpose of synthesising 12 : 13-dimethoxyisoindenoquinoline(XIIIa and XIIIb). The condensation of 4-keto-1 : 2 : 3 : 4-tetra-hydroquinoline with veratraldehyde in alcoholic sodium hydroxidett6 J., 1930, 2602. 66 D.R.-P. 459,616; B.P. 291,888.67 See Ann. Reports, 1929, 26, 164. 68 J., 1930, 2133188 PLANT :led to 4-hydroxy-3-veratrylquinolinealternative routes which were explored(XIV), but the variousin order to effect conversionof this product into (XIII) failed to give the desired result. It wasfound, however, that, when these two substances were condensed inglacial acetic acid in the presence of hydrogen chloride, the reactionyielded 4-keto-3-veratrylidene-1 : 2 : 3 : 4-tetrahydroquinoline (XV ;R = H), which was easily transformed into (XIV) by the action ofOH coalcoholic alkali.By the use of 4-keto-l-acetyl-1 : 2 : 3 : 4-tetra-hydroquinoline this latter possibility was avoided and the product(XV; R = Ac) then gave 4-keto-l-acetyl-3-veratryl-1 : 2 : 3 : 4-tetrahydroquinoline (XVI) on catalytic reduction. The substance(XVI) was converted into (XIII) by the action of warm sulphuricacid (SO%), a process which involved deacetylation and oxidationin addition to ring closure. The product was obtained in two inter-convertible forms (one faintly yellow and the other reddish-brown)which apparently are represented by the structures (XIIIct) and(XIIIb) respectively.co(XVI.)T.R. Seshadri,G9 during an investigation of some aminoalkyl-quinolinium salts, has made the interesting observation that theaction of aqueous sodium hydroxide on p-aminoethylquinoliniumbromide hydrobromide (XVII) leads to a base for which the structure(XVIII) is proposed. S. Gabriel 7O suggested the constitution(XIX) for an analogous pyridine derivative, but this is very unlikely.Investigations by S. G. P. Plant and R. J. Roaser 71 into the6@ J., 1929, 2962. 70 Ber., 1920, 68, [B], 1986.7 1 J., 1929, 1861; 1930, 2444ORGANIC OHEMISTRY.-PART III. 189reduction of certain simple quinolines under various conditionshave shown that, although 2 : 3-dimethyl- and 2 : 4-dimethyl-quinozine readily give the two stereoisomeric modifications (cis- andtrans-) of 2 : 3-dimethyl- and 2 : 4-dimethyl-1 : 2 : 3 : 4-tetrahydro-quinoline respectively, the 3 : 4-dimethyl compound yields only oneof the two possible forms of its tetrahydro-derivative.Anexplanation of this fact can be found in the steric effect of the4-methyl group in the intermediate 3 : 4-dimethyl-1 : 4-&hydro-quinoline, which is to displace the 3-methyl group from its sym-metrical position with respect to the double bond. As a result ofthis, the subsequent addition of a hydrogen atom in the 3-positiontakes place in one only of the two possible directions. The actionCHMe EP Y ‘YH 0 V-YH NHCH,-CH,(XVIII.) (XIX.) (XX.1HCH,-CH,of sodium amalgam upon 2-keto-3 : 4-dimethyl-1 : 2-&hydro-quinoline in alcoholic solution led to the two forms of (XX), butfurther reduction of this mipture by sodium and alcohol resultedin the single modiiication of 3 : 4-dimethyl-1 : 2 : 3 : 4-tetrahydro-quinoline.This fact is almost certainly explained by the inter-mediate formation in the latter reaction of 3 : 4-dimethylquinoline,traces of which were found in the product. A similar explanationwill account for the formation of only one modification of2 : 3 : 4 : 5 : 6 : 13-hexahydro-a-quinindene (XXI) during the reduc-tion of a mixture of the two stereoisomeric forms of 5-keto-2 : 3 : 4 : 5 : 6 : 13-hexahydro-a-quinindene 72 (XXII).H,C-?H,IH,C--YH,CHMe*CHMeHN<CHMe*CHMe>NH(=I.) (XXII.) (XXIII.)Five geometrical isomerides are possible in the case of 2 : 3 : 5 : 6-tetramethylpiperazine (XXIII), and it is of interest to record thatB’.B. Kipping 73 has isolated four of these by reducing 2 : 3 : 5 : 6-Reports, 1929,28, 164.72 B. K. Blount, W. H. Perkin, and S. G. P. Plant, J., 1929, 1975; Ann.J., 1929, 28891 90 PLANT :tetramethylpyrazine under various conditions. Previously onlytwo had been definitely identified.Alkaloids.In a study of the de-alkylation of tertiary amines by heatingwith organic acids J. von Braun and K. Weissbach 74 have includedan investigation of some cyclic bases. 2-Methyltetrahydroiso-quinoline was converted into 2-benzoyl- and 2- p-phenylpropionyl-tetrahydroisoquinoline by the action of the appropriate acid, andtropane yielded benzoyl- and @-phenylpropionyl-nortropane undersimilar conditions.Nicotine, on like treatment, gave productscontaining acylnornicotines, from which nornicotine (I) was obtainedon hydrolysis.Quinoline Group .-Further investigations by E. Spath andJ. Pikl 75 into the nature of the products obtained from angosturabark have resulted in the separation of four additional bases fromthe low-boiling fraction, vix., quinoline, 2-methylquinoline, 2-keto-l-methyl-1 : 2-dihydroquinoline, and 2-n-amylquinoline. The isol-ation of such simple bases from this source is of considerable interest.(1.) (11.) (111.)Y. Asahina, T. Ohta, and M. Inubuse 76 have isolated fromSkimmia repens a base, C,,H,O,N, which was found to be identicalwith dictamnine, an alkaloid obtained from Dictamnus a t l b ~ ~ , ~ ~and, from a study of its reactions, the formula (11) has been sug-gested. Thus it was found to contain one methoxyl group, thesecond oxygen atom appeared to be of the ether type, and, onoxidation with potassium permanganate, the alkaloid gave analdehyde (dictamnal), C1,H,O,N, together with the correspondingacid (dictamnic acid), C,,H,O,N.The latter, on heating withconcentrated hydrochloric or hydrobromic acid, yielded 2 : 4-di-hydroxyquinoline with the loss of a methyl group and carbondioxide ; it was found, however, not to be identical with a syntheticalspecimen of 4-hydroxy-2-methoxyquinoline-3-carboxylic acid,78 soMonatsh., 1930, 55, 352; A., 1049; for earlier work, see Ann.Reports,76 Ber., 1930, 63, [B], 2045; A., 1454.7 7 H. Thorns, A., 1923, i, 639.74 Ber., 1930, 63, [B], 489, 2018; A., 458, 1444.1924, 21, 131 ; 1929, 26, 170.Prepared by a method analogous to that described by C. A. BLchoff,Annalen, 1889, 251, 360ORGANIC CHEMISTRY.-PART III. 191that it appears to be 2-hydroxy-4-methoxyquinoline-3-carboxylicacid (111).It has also been shown, by Y. Asahina and M. Inub~se,'~ thatthe alkaloid skimmianine, isolated by J. Honda 8O from SEimmiajaponica, has the molecular formula C,,H 1304N and is closely relatedto dictamnine. It contains three methoxyl groups, and, on oxid-ation with potassium permanganate, it yielded an aldehyde,C13Hl,0,N, and an acid, C13H13OGN.The acid, on heating withconcentrated hydrochloric acid, lost a methyl group and carbondioxide with the formation of a product which was shown syn-thetically to be 2 : 4-dihydroxy-7 : 8-dimethoxyquinoline (IV).OHThis synthesis was accomplished *l by condensing 2-nitro-3 : 4-di-methoxybenzoyl chloride with malonic ester and heating the productwith tin and alcoholic hydrochloric acid. Skimmianine, therefore,appears to be a dimethoxydictamnine of the constitution (V).isoQuinidine, which does not occur naturally, is obtained whenits isomeride, quinidine (itself a naturally occurring isomeride ofquinine), is dissolved in warm sulphuric acid. A. Konopnicki andJ. Suszko 82 amert that several of the reactions of isoquinidine areexplicable with the aid of formula (VI).It is not acted upon byacid chlorides, acetic anhydride, the Grignard reagent, phenyl-hydrazine, or semicarbazide. The bwe also forms a mono- and adi-methiodide, an oxide (with hydrogen peroxide), and two per-bromides, both of which give isoquinidine with dilute alkalis. Byheating isoquinidine sulphate alone, or the free base in 25% aceticacid, another isomeride, iaoquinicine, is produced. The latter is notketonic in characfer, but appears to contain an >NH group, whichcan be acetylated, nitrosated, and methylated.isoQuinoZine Croup.-A considerable amount of work dealingwith the chemistry of substances of the papaverine type has beenBer., 1930, 03, [B], 2062; A., 1464.81 Y. Asahina and S. Nakanishi, Ber., 1930,63, [B], 2067; A., 1445.Bull.Acad. Polonaise, 1929, A , 340; A,, 1930, 97.no A., 1906, i, 152192 PLANT :recorded during the year. By suitable modification of the well-known synthesis of Pictet and G a m ~ , ~ ~ J. s. Buck has preparedthe hitherto unknown 1 : 2-dihydropapaverine (IV). w-Homo-veratroylaminoacetoveratrone (I) was dehydrated by means ofphosphoryl chloride to give (11) ; this was catalytically reduced to(111), which was treated with phosphorus pentachloride in coldco M e O o z ( i ' H 2 CH-OHMeo \pCH2X Q CH2X(1.) (11.) (111.)CH CH CHTo CH2XCH2X co*x co*x(IV.) (V.) (VI.)(X = 3 : 4-dimethoxyphenyl)chloroform with the production of (IV). 1 : 2-Dihydropapaverinewas reduced catalytically to tetrahydropapaverine, and dehydrogen-ated to give papaverine by heating with palladium-black. Itreadily underwent oxidation by air to the ketone (V), and, whenheated with methyl-alcoholic potassium hydroxide, it yieldedpapaveraldine (VI). In the latter reactions 1 : 2-dihydropapaverineclosely resembles its 3 : 4-is0meride.8~I.men and J. S. Buck86 have investigated the possibility ofpreparing substances of the papaverine type by the application ofa reaction already used in the isoquinoline series,87 vix., fromderivatives of benzylaminoacetal by ring closure and oxidation.The oxime of deoxyveratroin (VII) was reduced with sodiumamalgam and alcoholic acetic acid to @-di-(3 : 4-dimethoxypheny1)-ethylamine (VIII), but the product derived from the condensationof this substance and bromoacetal was completely decomposed bytreatment with sulphuric acid and arsenic oxide in an attempt toprepare papaverine.Similar results were obtained with theanalogous di-methylenedioxy-derivative from deoxypiperoin.8s Ber., 1909, 42, 2943.84 J . Amer. Chem. SOC., 1930, 52, 3610; A., 1455.8 5 See J. S . Buck, R. D. Haworth, and W. H. Perkin, J., 1924, 125, 2176.86 J . Amer. Chem. SOC., 1930, 52, 310; A., 353.87 See, e.g., L. Rugheher and P. Schon, Ber., 1909, 42, 2374ORGANIC CHEMISTRY.-PART III. 193CH2E:EgH2 CH(VII.) (VIII.)Having in mind the possible route by which the papaverinealkaloids are formed in nature,88 E. Spiith and F. Berger 89 havestudied the condensation of homoveratrylamine with 3 : 4-dimethoxy -phenylacetaldehyde, and the conversion of the product (IX) intodl-tetrahydropapaverine. Ring closure was accomplished with19% hydrochloric acid, but the yield of the tetrahydro-base wassmall (8%).of the reactionsof coclaurine, an alkaloid from CocczcZus Zaurifoliw, has shown thatit is represented by the formula (X).The following were the mainobservations which led to this result and established the relativeAn investigation by H. Kondo and T. Kondopositions of the6 OHmethoxyl and hydroxyl groups. The metho-(XI-) (XII.)sulphate of the triethyl derivative of coclaurine gave a product(XI) by the Hofmann degradation process, which, on oxidation,yielded p-ethoxybenzoic acid and the acid (XII). The structureof the latter was established by a further application of the Hof-mann process to give 4-methoxy-3-ethoxy-6-vinylbenzoic acid, and,on subsequent reduction, 4-met~hoxy-3-ethoxy-6-ethylbenzoic acid,the identity of which was confirmed by synthesis.Furthermore,the dehydration of p-methoxyphenylaceto-P-3 : Q-dimethoxyphenyl-88 See R. Robinson, J . , 1917,111, 876.88 Ber., 1930, 63, [B], 2098; A., 1454.00 J. pr. Chem., 1930, [ii], 126, 24; A., 794.REP.-VOL. XXVII. 194 PLANT :ethylamide (XIII) gave an isoquinoline derivative, which, onreduction and subsequent treatment with methyl sulphate, gave themethosulphate of trimethylcoclaurine ; the latter was identical withthe product obtained directly from the alkaloid by the action ofmethyl sulphate and alkali. The formula (XIV) has been assignedby H.Kondo and Z. Narita 91 to dauricine, an alkaloid from Meni-spermum dauricurn, as a result of an investigation of the oxidationproducts derived from the nitrogen-free compounds obtained by anapplication of the Hofmann degradation process to methyldauricinemethiodide and ethyldauricine ethobromide. The alkaloid thusappears to be closely related to coclaurine, although F. Faltis andH. Frauendorfer92 have expressed the view that it has a morecomplex structure (XV) of the bimolecular type with an oxygenbridge.In the formulae previously advanced for isochondodendrine methylether 93 the exact points of attachment of the two methoxyl groupsand the ether-oxygen to the isoquinoline system have been indoubt. I n solving this particular problem much has dependedupon the positions of the snbstituent groups in a tricarboxydi-methoxydiphenyl ether which was obtained by the oxidation of theproduct derived from the Hofmann degradation of the methyl ether.F.Faltis and H. Frauendorfer 94 have now established syntheticallythat this acid is 2 : 3-dimethoxydiphenyl ether 5 : 6 : 4’-tricarboxylicO4 Loc.cit.g1 Chem. Zentr., 1927, ii, 264; 1929, ii, 1926; Ber., 1930, 63, [B], 2420.Ber., 1930,63, [B], 806. O8 See Ann. Reporta, 1928,25,190ORGANIC CHEMISTRY.-PART III. 195acid (XVI), a fact which necessitates a revision of the earlier formulsin favour of one of the two alternatives (XVII) and (XVIII). 9 C02H gg$:g2eCH2HO2C($0Me H02C OMe lc\l(XVI.) (XVII.) (XVIII.)The formuls previously assigned to chelidonine cannot be regardedas satisfactory, and, as a result of a review of the reactions of thisalkaloid, together with a consideration of its relationship to proto-pine and a re-investigation of the structure of a degradation product,F.von Bruchhausen and H. W. Bersch 95 have now advanced theformula (XIX). Confirmation of these views from degradative andsynthetical experiments will be awaited with interest, since thestructures to be assigned to related alkaloids, such as chelerythrine,are involved.(XIX.)HOMe0Me0Me082Me0Me0 H2(111.)9 5 Ber., 1930, 65, [BJ, 2620196 PLANT :Aporphine Group.-After considerable activity during the pre-ceding two years, there is comparatively little to record on thisoccasion concerning members of the aporphine group.One interest-ing development, however, has been the isolation and investigationby J. Gog6 of Z-corydine and d-isocorydine, together with otheralkaloids, from CorydaZis ternata. Previous work 97 has settled thestructures of the closely related alkaloids bulbocapnine (I) andcorytuberine (11), and J. Gadamerg* has suggested the formulae(111) and (IV) for corydine and isocorydine respectively, a mixtureof these two products being obtained by the monomethylation ofcorytuberine. The new work indicates, however, that corydinehas the structure (IV) and isocorydine (111). Thus bulbocapnineethyl ether was converted into the substance (V; R = H) andsubsequently methylated, the resulting derivative (V; R = Me)being found to be identical with d-corydine ethyl ether.DiisoquinoZine Group.-K.Goto and H. Sudzuki g9 recentlydescribed the isolation of a new alkaloid, sinactine, in small quanti-ties from Sinomenium acutum, and it has now been identified byK. Goto and Z. Kitasato 1 as Z-tetrahydroepiberberine (VI). Oxid-ation with iodine in alcoholic solution led to epiberberinium salts,which, on subsequent reduction of the chloride, yielded dl-sinactine ;this proved to be identical withh ydroepi berberine .2OMea specimen of iynthetical dZ-tetra-O-YH,IO-FH, I(VIII.)Me0 CH96 J . Pharm. Xoc. Japan, 1929,49, 125, 126, 129; Chem. Zentr., 1930, i, 234.9 7 See Ann. Reports, 1928, 25, 187.98 Arch. Pharm., 1911, 249, 503.99 Bull.Chem. SOC. Japan, 1929, 4, 220; Ann. Reports, 1929, 26, 181.1 J., 1930, 1234.2 W. H. Perkin, J., 1918,113, 512 ; R. D. Hsworth and W. H. Perkin, J.,1926, 1777ORGAXIC CHEMISTRY.-PART I". 197The supposed synthesis of tetrahydroberberine by Pictet andGams3 was shown to be unsound by the work of R. D. Haworth,W. H. Perkin, and J. Railkin,4 and further investigations of thereactions concerned have now been described by J. S. Buck andR. M. Davis,5 who have shown that the substance which was believedby Pictet and Gams to be veratrylnorhydrohydrastinine (VII)is, in reality, 9-keto-6 : 7-methylenedioxy-3' : 4'-dimethoxyproto-papaverine (VIII). In actual fact, a mixture of these two productswas found to result during the earlier stages of the synthesis.Morphine Croup.-The " thebainone " prepared by R.Pschorr 6by reducing thebaine with stannous chloride and concentratedhydrochloric acid is regarded by C. Schopf and P. Borkowsky 7 ashaving the structure (I). Since dihydrothebainone, hydroxythe-bainone, and hydroxydihydrothebainone do not have the samering system as Pschorr's product, it is now suggested by C . Schopfand (Frl.) H. Perrey 8 that the latter should be called " metathe-bainone," the name " thebainone " being reserved for the substance(11)-The conversion of derivatives of dihydrocodeinone (111; R = H)into compounds of the dihydrothebainone (IV ; R = H) type, withthe rupture of the oxygen bridge and consequent appearance of aphenolic hydroxyl group in the 4-position, is well known as a featureof hydrogenation processes in the morphine series.The conversetransformation of dihydrothebainone into dihydrocodeinone hasnow been accomplished by C. Schopf and T. Pfeifer by fist con-verting the former substance into its l-bromo-derivative. Furtherbromination gave a product (V), which, by treatment with alkali,Ber., 1911, 44, 2480.J., 1924,125, 1686; Ann. Reports, 1924,21, 134.Annalen, 1927,458,148 ; Ann. Reports, 1928,25, 192.Anden, 1930,483, 169.li J . Amr. Chem. SOC., 1930, 52, 660; A., 485. Ber., 1905, 38, 3160.Ibid., p. 157198 PLANT :yielded 1 -bromodihydrocodeinone. The removal of the halogenatom with the formation of dihydrocodeinone was accomplishedby catalytic hydrogenation. The reduction of 1 -bromodihydro-%QI FH2 C CH%()\C CHI QH2 C CHcodeinone with zinc dust in alcohol gave l-bromodihydrothebainone.By a similar series of reactions hydroxydihydrothebainone (IV ;R = OH) has been converted into hydroxydihydrocodeinone (111;R = OH), and the bromosinomeneine obtained by the successiveaction of bromine and alkali on sinomenine lo (VI) is apparentlyformed by an analogous process and can be represented by theformula (VII), whereby it appears as an optical isomeride of l-bromo-7-methoxycodeinone.By bromination of dihydrometathebainone(VIII) (previously called " thebainol "), followed by the action ofalkali, 1-bromodihydrometacodeinone has been obtained, and thishas been converted by catalytic hydrogenation into dihydrometa-( 7 3 2CH bH-NMe v\/ I HC\/ \/OMe CH2 CH,(VII.) (VIII.) (IX.)codeinone (IX), which can be transformed into dihydrometa-thebainone again by the action of sodium amalgam. Dihydro-metacodeinone is readily converted by acids or alkalis into theisomeric metathebainone (I).lo K. Goto, J . Chem. SOC. Japan, 1923,44, 815 ; K. Goto and T. Nakamura,Bull. Chm. SOC. Japan, 1929, 4, 195; K. Goto and T. Nambo, ibid., 1930,5, 165.11 C. Schopf and (Frl.) H. Perrey, loc. citORGANIC CHEMISTRY .-PART 111. 199The spatial configurations of several members of the morphinegroup have recently been discussed by H. Emde.12Strychnine.-Further investigations into the chemistry ofstrychnine derivatives have necessitated the abandonment offormula (I), which was advanced for this alkaloid two years ago,lSand, in its place, a new formula (11) has been put forward by K. N.Menon, (the late) W. H. Perkin, and R. Robinson.l4 In thedevelopment of these structural views much has depended on thenature of dinitrostrycholcarboxylic acid, CSNH,(OH)2(N0,),*C02H,which is obtained from the alkaloid by heating it first with diluteand then with concentrated nitric acid. A fundamental postulateC,H,in the development of the earlier structure was that dinitrostrycholis a dinitrodihydroxyisoquinoline, but it has now been conclusivelyshown that this substance is a quinoline derivative, as originallybelieved. Thus dinitrostrycholcarboxylic acid was converted duringesterification into ethyl dinitro-0-ethylstrycholcarboxylate,CSNH2(NO2),( OH)(OEt)*CO,Et, which was transformed via thehydrazide and the usual Curtius reactions into the correspondingurethane, C,NH2(N0,),(OH)(OEt)*NH*C0,Et. The urethane, unlikedinitrostrycholcarboxylic acid, was degraded by hot nitric acid toyield picric acid, a result which is consistent with a quinoline, butnot an isoquinoline, structure for strychol. Furthermore, theurethane, by hydrolysis and subsequent oxidation with permangan-ate, was converted into 5 : 7-dinitroisatin (111). From the evidenceCO,H OH No2wcz N o W g g HNO, NH NO, N NO, N(111.) (IV.) (V.)la Helv. Chim. Acta, 1930, 13, 1035.1s R. C. Fawcett, W. H. Perkin, and R. Robinson, J., 1928, 3082; W. H.Perkin and R. Robinson, J., 1929, 964; Ann. Reports, 1928, 25, 193; 1929,26, 181. l4 J., 1930, 830200 PLANT :now available it is possible to say that dinitrostrycholcarboxylicacid must have one of the structures (IV) and (V).It will be noticed that the carbazole nucleus, a feature of formula(I) as well as of the original strychnine formula of W. H. Perkinand R. Robinson,15 is absent from the new structure. The evidencefor its presence, vix., the isolation of carbazole from the degradationof the strychnine molecule, was always uncertain on account of thevigorous nature of the experimental conditions and the ease withwhich the carbazole system can be formed from other types. Severalcharacteristics of formula (I) must, however, be regarded as estab-lished, e.g., the existence and arrangement of the ether oxygen andthe ethylenic linkage, and these are embodied in the new formula.A fundamental point in the development of formula (11) is thatthe hydroxyl group in position 3 in the quinoline ring of dinitro-strycholcarboxylic acid fixes the position of the second nitrogen atomin strychnine. Only in this way can the formation of the 3-hydroxylgroup during the degradation of strychnine be accounted for. Thenew formula provides an excellent explanation of many of thecomplex changes observed in the chemistry of this alkaloid andthereby obtains further justification.p 2 - q H Y C H 2 Thus, for example, the presenceCK I A,/ of the grouping :N*CH,*y:CH%H,*O*,\?a/ ,A?H, and its successive transformation to:NCO*q( OH)*CO*CH,*O*,N /yg/c\\, :N*CO*yH( OH) + CO,H*CH,*O* I I I (by hydrolysis), and :N*CO*YO +c* CH CH, CO,H*CH,*O*, accounts for the \d \o/ formation of dihydrostrychninonicacid, and then strychninonic acid,by the oxidation of strychnine withpermanganate. In formula (11) the exact arrangement of certaincarbon and hydrogen atoms, comprising C2H,, still remains t o bedecided. There are several possibilities, and the authors suggestprovisionally a bridge formulation of the type (VI), which isclosely related to the cinchonine structure.MisceZZuneous AZkuZoids.-Of the many possible stereoisomericmodifications of ephedrine and related substances, six have so farbeen recognised amongst the constituents of the Chinese drug MaHuang, wix., Z-ephedrine (I), d-$-ephedrine (I), Z-methylephedrine(11), d-methyl-+ephedrine (11), nor-&#-ephedrine (111), and nor-Ph YH-7 HMe PhyH-YHMe Php-yHMeOH NHMe OH NMe, OH NH2(1.1 (11.1 (111.)l 6 J . , 1910, 97, 305.(VI.ORGANIC CHEMISTRY.-PART III. 201Z-ephedrine (111) .I6 Considerable work has recently been devotedto the synthesis of the two stereoisomeric inactive bases, nor-dl-ephedrine and nor-dZ-+ephedrine, of the formula (111). D. H. Hey l7has found that the direct reduction of isonitrosopropiophenone (IV)in the desired direction is difficult, although it has apparently beenachieved catalytically,l* but the action of sodium amalgam onphenylacetylcarbinol oxime (V) in dilute acetic acid solution ledmore readily to a mixture of the two stereoisomerides. In addition,W. N. Nagai and S. Kanao l9 found that the reduction of p-nitro-a-phenylpropyl alcohol (VI) with iron and aqueous alcoholic sulphuricacid, or with tin and hydrochloric acid, led to a mixture of the twoinactive bases (111), which were subsequently resolved with the aidof d- and Z-tartaric acids. C. S. Gibson and B. Levin20 havePhE-Me PhYH-e Ph YH-THMe0 NOH OH NOH OH NO,(IV.) (V.1 (VI.)employed the natural nor-&+-ephedrine as a convenient base forthe resolution of some externally compensated acids.Previous investigations into the alkaloids of ergot have shownthat ergotoxine and ergotinine are interconvertible, as also areergotamine and ergotaminine. Furthermore, the properties andpharmacological action of ergotoxine and ergotamine hithertodescribed are so similar as to have promoted suspicion that thesetwo alkaloids are really identical and that small observed differenceswere due to impurities. This possibility has now been removed byS. Smith and G. M. Timmis,21 who have prepared all four alkaloidsin a state of purity from different specimens of ergot. A carefulexamination of their physical properties clearly indicates thatthey are definite and distinct substances. Little evidence is, as yet,forthcoming regarding the constitutions and inter-relationships ofthese alkaloids.Mention may be made in this section of interesting developmentswhich have recently occurred in the chemistry of certain pungentacid amides. The structure (VII; R = H) assigned to capsaicin,the pungent principle of Capsicurn annuurn, which has been basedl6 S . Smith, J., 1928, 51; W. Nagai and S. Kanao, J . Pharm. SOC. Japan,1928,48, 101; Chem. Zentr., 1928, ii, 2553; S. Kanao, Ber., 1930, 63, [B], 95;A., 362.l7 J . , 1930, 18, 1232.P. Rabe, Ber., 1912, 45, 2166; W. H. Hartung and J. C. Munch, J .Amer. Chem. SOC., 1929, 51, 2262.lo Annalen, 1929,470, 167; A., 1929, 807.2o J., 1929, 2754.21 J . , 1930, 1390202 ORGANIC CHEMISTRY .-PART 111.upon the degradative reactions of this substance,22 hasOMe OR CHMe,*CH:CH*[CH,],*CO*NH*CH,confirmation from a synthesis by E. Spath and S.now received(VII.)F. Darling.23The keto-acid, CHMe2*CH,*CO*[CH2],*C02H, from the action ofzinc isobutyl iodide on the chloride of ethyl hydrogen adipate, wasreduced with sodium and alcohol to the corresponding secondaryalcohol, from which the bromide, CHMe,*CH,*CHBrfCH,],*CO,H,was obtained on heating with fuming hydrobromic acid. Thecorresponding ester was then distilled with quinoline, and the productwas treated successively with sodium hydroxide, thionyl chloride,and veratrylamine to give capsaicin methyl ether (VII; R = Me).Hydrolysis of the latter gave the unsaturated acid,from the chloride of which capsaicin was obtained on interactionwith vanillylamine. The position of the double linkage in thealiphatic section of the molecule has been established by oxidationexperiments. Spilanthol, the pungent principle of para cress, hashitherto been regarded as the isobutylamide of a n-nonenecarboxylicacid, yielding n-decoisobutylamide on the addition of two atoms ofhydrogen,24 but M. Asano and T. Kanematsu 25 have made a furtherpurification of this substance and now believe that it has two atomsof hydrogen less than was originally supposed. Thus it is stated toabsorb four atoms of hydrogen when it is converted into n-decoiso-butylamide. Since oxidation with ozone gave succinic acid,n-valeric acid, and formic acid, the structureis assigned to it. A product closely related to spilanthol is pelli-torine, the pungent principle of Anacyclus pyrethrum, which hasrecently been investigated by J. M. Gulland and G. U. Hopton,26who came to the conclusion that it is the isobutylamide of an-nonadienecarboxylic acid, C9H,,*C0,H, absorbing four atoms ofhydrogen on catalytic reduction to give n-decoisobutylamide. Theseviews are not in entire agreement with those of E. Ott and A. Behr,,'who have stated that pellitorine is the isobutylamide of a n-decadiene-carboxylic acid, C,,H1,*CO,H.CHMe,*CH:CH*[CH,],-CO,H,CH,*[CH,]3*CH:C:CH*[CH2]2*CO*NH*CH2.CRMe2S. G. P . PLANT.22 See, e.g., E. K. Nelson and L. E. Dawson, J . Amer. Chem. SOC., 1923, 45,23 Ber., 1930, 63, [B], 737; A., 599.24 Y. Asahina and M. Asano, J. Pharm. SOC. Japan, 1920, 503 ; 1922, 85.26 Ibid., 1927, No. 644, 521.2 6 J . , 1930, 6.2179; A., 1923, i, 1108.27 Ber., 1927, 60, [B], 2284; A., 1928, 50

ISSN:0365-6217    

DOI:10.1039/AR9302700082

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.IN addition to the application of chemical reactions to qualitativeand quantitative work, the period under review has furnished somedefinite advances in the utilisation of physical methods for analyticalpurposes. The magneto-optic method (Paraday effect) has not,so far as we are aware, been applied hitherto to the detection ofkations. It has, of course, been utilised for investigations ofoptical rotation in the magnetic field, but the paper by F. Allisonand E. J. Murphy points out a method of test equal to the mostdelicate of the methods now available. As is well known, theFaraday effect consists in the rotation of the plane of polarisation oflight on passing through a liquid, when this is placed in a magneticfield, and it has been supposed that this effect followed immediatelyon the application of the magnetic field.Allison and his co-workershave produced evidence in favour of a time-lag between the Faradayeffect and the magnetic field, the time-lag being utilised for thedetection of kations. This is accomplished by using two liquid cellsof equal dimensions, so arranged that the alternating electricimpulse obtained by means of a high-potential spark between metalelectrodes is divided in the electric circuit, so that the opticalrotation due to the magnetic field produced in the solenoid woundround the observation cells is in opposite directions. The arrange-ment of apparatus is such t'hat light, plane polarised through aNicol prism, passes through the first cell, then traverses the air spaceto the second cell and passes through this cell, which is followed byanother Nicol prism originally crossed so as to extinguish the lightfrom the first prism.Since there is an air gap between the two cells,the light takes a short time (Le., the distance between the cell centresin cm. divided by 3 x lolo, the velocity of light) to reach the secondcell. The length of the circuit to the winding around the second cellis therefore vaned, by means of movable contacts, so that theelectric impulse reaches this solenoid in the time equal to that takenfor the light to traverse the distance between the centres of the twocells. In the case where the same liquid is used in both cells, nolight will pass through the second crossed Nicol with this arrange-ment of apparatus.Carbon disulphide is chosen as a standard towhich other liquids are referred, since it shows the smallest time-lagJ . Amer. Chern. h'oc., 1930,52,3796; A., 1641204 ELLIS AND FOX:between the Faraday effect and the magnetic field, and the apparatusis adjusted to zero position with both cells containing this liquid. Ifnow, one cell is filled with another liquid, say carbon tetrachloride,it is found that in order to extinguish the light, or to obtain a sharpminimum of light passing through the second Nicol, it is necessaryto move the cell back, or else to alter the length of the electriccircuit, which effects the same purpose. The distance through whichthe cell is moved or the alteration in length of the circuit divided bythe velocity of light gives a value for the time-lag of the liquidreferred to carbon disulphide as a standard.It was found that eachcompound, organic or inorganic, has its own time-lag and thusproduces a minimum of light at a point characteristic of the com-pound. Further, in a mixture, each compound retains its owntime-lag. Each kation has its own minimum or several minimawhich appear to depend on the number of isotopes. The chloridesare best adapted for investigation, since the minima are separatedfarthest in these compounds. An unexpected result of this inquirywas that compounds retained their characteristic minima until theconcentration was reduced below 1 in 1O1O, whereupon the minimafaded out. The apparatus has to be calibrated for the kation beingsought for, and when this is done it seems to be available for deter-mining solubilities of slightly soluble salts, or for mixtures.Examplesof the extent of the time-lags referred to carbon disulphide are thefollowing : zinc chloride (four isotopes) - 6-08, -6.40, - 6.73, and- 6-85 x 10-9 sec. ; lead chloride (four) - 21.90, - 22-07, - 22.30,and - 22-68 x 10-9 sec. As the tirne-lags could be determinedwithin 0-2 x sec. on different occasions, and were much closerfor any individual set of experiments, the method appears capable ofwide application.The use of X-rays in quantitative chemical analysis is now takingshape more definitely as a practical means of technical analysis forgeneral laboratory use.Chemical and spectroscopic methods oftest depend upon the outer electrons of the atom, while X-rayspectra which utilise the K and L electrons lend themselves especiallyto “atomic ” analysis by reason of the simplicity of the spectracompared with optical spectra. The X-ray spectra themselves areunequivocal for the element, since the K-line suspected to belong toan element need only be accepted if the whole series of K-lines of thatelement is present. This gives a check on the method at once, andit differs from the optical spectral method which depends in the limiton persistent spectral lines. has utilised both the Kand L spectra for the detection of impurities in zinc, and is able, ingeneral, to identify metallic elements from chromium (at.no. 24)2 T. H. Laby, Trans. Faraday Soc., 1930,26,497; A., 1141.T. H. LabANALYTICAL CHEMISTRY. 205upwards. He has in this way discovered minute traces of impuritiessuch as gallium, germanium, molybdenum , and tungsten, presentin quantities which would escape detection by chemical methods asordinarily applied to the analysis of spelter. It is pointed out byLaby that the advantages of the method are that one photographof the X-ray spectrum gives all the elements from chromium touranium, that analysis of chemically similar elements such as therare earths is more easily carried nut, and that the specimen is notconsumed in the examination. A communication3 on the applic-ation of X-ray spectroscopy to quantitative analysis demonstratesthat certain alloys of copper and zinc, tin and cadmium, lead andbismuth, and so on, may be analysed with an accuracy of 0.5% of theconstituent, provided the metals are those of close atomic numbers.Another X-ray method for quantitative analysis utilises secondaryX-rays4 and a special form of tube so that the substance underinvestigation is supported on a screen, but is separated from thehigh vacuum of the tube itself by means of a thin aluminium sheet.An anticathode giving harder radiation than the edges of the absorp-tion band of the element undergoing examination is used to producethe secondary radiation and this is compared with the lines furnishedby a standard substance known to be present in definite amount.Atable is now available giving the principal comparison lines of thesecondary radiation for the elements from sodium to uranium, sothat the choice of a suitable standard substance becomes compara-tively easy.For this purpose the rare earths offer special advantages,for they are unlikely to occur in any ordinary material which is beingexamined, thus permitting of their addition in definite amountswithout introducing any error due to the sample itself containing therare earth. This method is claimed to give the proportion of anelement which is present to the extent of 1 yo or so, with an accuracyof 0.01%. A method similar to the foregoing has recently beenapplied to the determination of potassium in soils with verysuccessful results. In this case a known amount of manganese oxideis incorporated with the soil, and the proportion of potassium foundby comparing the intensity photographically of the potassium lineKu, of wave-length 3734 X.U.* with the second-order KP, line ofmanganese which appears at 3812 X.U.Of the more recent applications of the optical spectroscopicmethod, one of the most interesting deals with the determination ofcadmium, lead, and iron in zinc.6 It is shown how quantities ofC.E. Eddy and T. H. Laby, Proc. Roy. Soc., 1930, [A], 127, 20; A., 724.G. von Hevesy, J. Bohm, and A. Faessler, 2. Physik, 1930,63,74; A., 1141.J. T. Calvert, Trans. Paraday SOC., 1930, 26, 509.D. M. Smith, ibid., p. 101. * 1 X.U. = 10-l1 cm206 ELLIS AND FOX:impurities of the order of 0.001 yo can be detected and estimated witha fair degree of accuracy in a very short time.The method employseither arc or spark spectra obtained with electrodes of the metalbeing tested under carefully controlled conditions ; the impurity isestimated by comparing visually on the spectrogram, the intensityof a fixed line of the impurity with that of a near-by line due to thezinc itself. Tables are given showing the most suitable lines forexamination. Thus, cadmium line A 2144.4 is compared with zincline A 2147.4, and this enables one to estimate the cadmium whenpresent in proportions from 0-1 to 0.001 yo. Similarly, lead and ironmay be determined within certain limits imposed by considerationsof the accuracy of determining intensities of lines on photographicplates. A variation of the method is that employing an '' auxiliary "spectrum of some other metal.' Thus, in the determination ofcadmium in zinc, there is superimposed on the zinc spectrum aspect,rum derived from pure tin electrodes, and the slit of thespectrograph is shortened so that short tin lines are readily recogniseddistributed amongst the longer zinc lines.Pairs of cadmium andtin lines are then chosen of equal intensity and compared with atable showing for different proportions of cadmium in zinc whichlines show equal intensity on the photographic plate. The use of amethod such as that described enables large numbers of specimensof zinc to be tested rapidly for the impurities mentioned and for anyothers for which calibration can be effected in a similar manner.Itis to be noted that the methods described above give results whichare specific for particular elements, and in this respect they possess adefinite advantage over most other physical methods applied to theanalysis of mixtures, e.g., refractivity or viscosity. There is afurther advantage inasmuch as the quantity of material required issmall and is not destroyed in the test. In this respect the processeshave an advantage over purely chemical methods, but it is not to beinferred, therefore, that the advantage is wholly with the physicalmethods. These fail to be delicate enough with certain elementssuch as phosphorus or arsenic, and they are not so good as a chemicalmethod when adequate material for test is available in such casesas the determination of lead, copper, iron, nickel, when these arepresent in large or in very small proportion of the order of 0.001%.An interesting procedure for the identification of volatile organicliquids is furnished by determining the variation of the azeotropismof the binary system consisting of the substance to be identified andsome standard pure liquid.8 The deviation in azeotropism is' W.Gerlach, 2. Metallk., 1928, 20, 248; 2. anorg. Chem., 1924, 142, 387.M. Lecat, 2. physikal. Chem., 1930, 148, 232; Bull. Acad. roy. Belg., 1929,[v], 15, 1073; A., 724ANALYTICAL CHEMISTRY. 207found from the difference in boiling point of the standard liquid andof the binary azeotrope formed with it. Tables are availableshowing the limits of azeotropism for hydrocarbons, alcohols, esters,and ketones boiling from 80" to 225", and for the constants ofsuitable standard liquids.In some cases two or three binarysystems may have to be examined before the unknown liquid can beidentified, but the method is fairly rapid and requires little materialfor examination.When large numbers of determinations of halogens in organiccompounds have to be made, the ordinary Carius method, or heatingwith lime, is slow and rather cumbersome. It was shown some timeago9 that a modified Kjeldahl method using chromic oxide inaddition to sulphuric acid was capable of giving accurate results onthe determination of chlorine and bromine. A similar method, butone which is suitable for iodine as well as chlorine and bromine, hasnow been worked out: lo it has also been applied successfully to themicrochemical determination of halogens and metals l1 in organiccompounds.In this process, fuming sulphuric acid, alone or withoxidising reagents, is employed in a special form of apparatus. Forchlorine and bromine, the liberation of halogen is complete and it maybe trapped in an alkaline arsenite solution for final estimation. Withiodine it is necessary to use'hydrogen peroxide to obtain free iodine,and some iodic acid may be formed. ' This is conveniently reducedby means of hydrazine, and the hydriodic acid oxidised to iodine byhydrogen peroxide. The results given for both macro- and micro-determinations are very good. These processes are rapid andcapable of being applied readily when numerous determinationshave t o be made.A further advantage of the second procedure isthat the digestion liquid from which the halogen has been expelled isavailable for determining other elements, particularly metals, presentin the compound investigated. This is of special convenience fororganic arsenic or antimony compounds. The method is likely togive low results for selenium, for it has been shown l2 that seleniumdioxide is appreciably volatile in open vessels. For this reason amodified Carius tube method was devised for organic seleniumcompounds on the micro-scrtle and gave very satisfactory resultswhen the precipitated selenium was weighed on a Pregl micro-Goochcrucible. The process was also found suitable for tellurium, but inview of the non-volatility of tellurium dioxide, the decomposition ofP.W. Robertson, J., 1916,109,218.lo J. J. Thompson and U. 0. Oakdale, J . Amer. Chem. Soc., 1930,52, 1195;11 H. H. Willard and J. J. Thompson, ibid., p. 1893; A., 940.l2 H. D . K. Drew and C. R. Porter, J., 1930, 2091.A., 799208 ELLIS AND FOX:the telluro-organic compound can be effected in a micro-Kjeldahlflask.Of the numerous applications of the micro-chemical methods ofanalysis, some of much importance are described in " Mikrochemie,Festschrift, 1930 " dedicated to Prof. F'riedrich Emich. A prelimin-ary communication l3 deals with the micro-methods for the examin-ation of beryllium silicate rocks working on a few milligrams ofsample. No claim for completeness is made, but a definite stepforward in micro-mineral analysis is here set out, for it is shown howthe following constituents may be separated *and determined :phosphoric oxide, aluminium, iron, beryllium, and magnesium.Inthis analysis the value of 8-hydroxyquinoline as a precipitant forkations is again demonstrated.An ingenious method of applying the micro-Dumas method fornitrogen determinations, while avoiding the use of a micro-balance,is to weigh out about 0.1 g. of material, and dissolve it in a knownamount of some solvent such as carbon tetrachloride. An aliquotportion of the solution is mixed with copper oxide and the solvent isallowed to evaporate away. The impregnated copper oxide is trans-ferred to a micro-Dumas combustion apparatus and the nitrogendetermined as usual.14In all precise micro-chemical work, proper facilities, includingseparate rooms, micro-chemical balances, and the special apparatusnecessary for accurate work, are desirable, but it is not so well knownthat a good ordinary chemical balance can readily be adapted forweighings to less than 0.01 mgm.The balance selected must be ofthe kind in which the suspension hooks for the pans are supportedwholly vertically below the agate planes and knife edges, withoutbends on the portion of the support rising to the agate planes.A. E. Conrady l5 has shown that by a method of calibration andweighing fully described, which avoids swinging of the pointer,it is possible to obtain weighings with normal loads, capable of beingreproduced to less than 0.01 mgm.A simple brake arrestment forthe pointer is needed, and this is readily made and attached. Thebrake is a useful addition to any precision balance since it enables thebalance arms and pointer to be released without vibration.Amongst the papers presented to the symposium on AnalyticalChemistry l6 held in Atlanta, Ga., in April 1930, are several impor-tant reviews which give succinct accounts of some modern analyticaldevelopments. Amongst these are three subjects of increasingl3 A. Benedetti-Pichler and F. Schreider, Ernich Festschrift, 1930, 1.l4 J. B. Niederl, 0. R. Trasitz, and W. J. Saschek, ibid., pp. 219, 232.l5 PYOC. Roy. SOC., 1922, [ A ] , 101, 211.l6 Ind. Eng. Chern.(Anal.), 1930, 2,INo. 3ANALYTICAL CHEMISTRY. 209interest for analytical chemistry : (1) Applications of photo-electriccells to chemical analysis,l7 which deals briefly with the types ofphoto-electric cells and their circuits and gives indications of theirpractical use in chemical investigations involving colorimetry ;(2) a review of the progress of potentiometric titrations,18 which givesan outline of the theory, shows the types of titration apparatus,and displays in an admirable manner the various kinds of titrationsfor which potentiometric methods have been employed ; and(3) conductometric titrations,lg a short account of some practicalmethods applied t o water analysis, the determination of the acidityof fruit juices, wines, and so on.In this connexion, attention is called t o the form of capillaryelectrode2O which is suitable for determining the pPH values at apoint in plant tissues.The apparatus is a small calomel half-cellfitted to a capillary agar-potassium chloride bridge, capable of usewith quinhydrone. Since it is sufficiently compact to be movedabout readily, it can be utilised for the exploration of plant tubers.The employment of ceric sulphate as an oxidising agent in volu-metric analysis is extending, for it has the advantage of being morestable than permanganate, is more reactive in the presence of acids,and it can be used in fairly concentrated hydrochloric acid solutions.The only reaction is Ce"" to Ce"', and there are no side reactions.The solution of ceric sulphate in dilute sulphuric acid is readilystandardised potentiometrically against ferrous sulphate,21 oragainst sodium oxalate.22 Determinations may be carried out inhot solutions, but in some cases the use of iodine chloride as acatalyst enables the titration to be carried out .at lower temperatures.In such cases methylene-blue may be used as an internal indicator forvisual titrations.Further applications of ceric sulphate solutionsare now available. Thallium can be determined electrometrically inwarm hydrochloric acid solutions, the results reported being quitesati~factory.~~ Tellurous acid may also be readily determined pro-vided chromic sulphate is added as a catalyst, a reaction whichpoints to much wider applications.24 A peculiar selective degree ofoxidation of organic acids has also been discovered, for whilst formic,acetic, succinic, fumaric, and maleic acids are not oxidised by cericsulphate, tartaric, malonic, malic, glycollic, and citric acids a,re sooxidised, although some peculiarities are to be observed in theproportion of Ce"" required per mol.of organic acid.23 Again,I. M. Kolthoff, ibid., p. 225.l7 H. M. Partridge, Ind. Eng. Clzem. ( A d . ) , 1930, 2, 207.l8 N. H. Furman, ibid., p. 213.2o I. M. Robertson and A. M. Smith, J . SOC. Chem. I d . , 1930,49,120~.21 N. H. Furmen, J . Arner. Chin. Soc., 1928, 50, 755; A., 1928, 499.22 H. H. Willard and (Miss) P. Young, ibid., p. 1322; A., 1928,725.23 Idem, ibid., 1930,52, 132; A., 312. 24 Idem, ibid., p. 555; A., 443210 ELLIS AND FOX:quinol is rapidly and completely oxidised to quinone, with thepeculiarity that the electrometric titration proceeds best when thequinol solution is added to the ceric sulphate solution.25 Usefulreversible indicators for the end-point of the titration of ferroussulphate with ceric sulphate are erio-glaucin A and alkali-fast (erio)green A.26 These indicators are yellow in ferric solutions and rose-coloured in ceric solutions.A comprehensive bibliography andreference to the use of ceric sulphate up to May 1930 is to be foundin Furman’s review of potentiometric titrations referred to above.18Inorganic Analysis.Qualitative.-A mixture of hexamethylenetetramine with potass-ium iodide forms a more sensitive reagent for the microchemicaldetection of the heavy metals than “ hexamine ” alone.27 Di-phenylthiocarbazone forms coloured complex compounds with manyheavy metals,28 whilst lead, bismuth, copper, and cobalt give color-ations with viscose solution.29 Systematic spot-analysis for thecommoner metals is further developed,30 and the effect of thepresence of other elements on some microscopical tests for metals hasbeen recorded.31 A specific reaction for cadmium with nitrophenol-arsinic acid is described,32 and the action of Meurice’s bromidebrucine reagent for cadmium on other heavy metals has beenin~estigated.~~Variations of a flame test for tin are de~cribed,~* also drop re-actions for lead 35 and for the mercurous Colour reactions ofsomewhat limited value are given by resorcinol with lead,37 andwith ~ i n c .~ 8 The use of certain phenolic acids has been applied tothe detection and separation of the metals of the analytical group25 N. H. Furman and J. H. Wallace, jun., J . Anzer. Chem. SOC., 1928, 50,1443 ; A., 727.26 Idem, ibid., p. 2347 ; A., 1012.27 I. M. Korenman, Pharm. Zentr., 1929, 70,709; A., 1929,1412; compare28 H. Fischer, 2. angew. Chem., 1929,42, 1025; A., 1929, 1412.29 J. V. Tamchyna, Chem. Listy, 1930, 24, 31 ; A., 443.30 K. Heller and Z. Fleischhans, Mikrochem., 1930,8, 33 ; A., 443 ; compareK. Heller and P. Krumholz, ibid., 1929, 7, 213; A., 1929, 900.31 W. F. Whitmore and F. Schneider, ibid., 1930,8,293 ; A,, 1148.32 F. Pavelka and E. Kolmer, ibid., p. 277; A., 1147.33 I.M. Korenman, Pharm. Zentr., 1929,70, 693; A., 1929, 1413.34 E. Schroer and A. Balandin, 2. anorg. Chem., 1930, 189, 258; A., 727;H. Meissner, 2 . anal. Chem., 1930,80,247; A., 882; F. L. Hahn, ibid., 1930, 82,113.idem, ibid., p. 1; A., 1929, 286.35 F. Pavelka, Mikrochem., 1929, 7, 301; A., 182.36 N. A. Tananaev, Ukrain. Chem. J., 1930, 5, 63; A., 1148.87 Ligor Bey and M. Faillebin, Bull. SOC. chim., 1930, [iv], 47, 225; A., 663.38 K. Fabrich, Verh. Geol. Bundesanst. Wien, 1929; A., 1147ANALYTICAL CHEMISTRY. 211IIA.30 Under suitable conditions, Feigl’s rhodanine reagent forsilver is very sensitive also for mercury and copper.40 The com-pounds of nickel, copper, and cobalt with dithio-oxamide can beutilised in microchemical tests for these metals.4l Diisonitroso-acetone is a more sensitive reagent for ferrous iron than dimethyl-glyoxime ; 42 reactions of aluminium, iron, chromium, manganese,zinc, nickel, and cobalt with organic reagents are ~ummarised.~~Bismuth alone interferes with the use of caesium sulphate as confirm-atory reagent in detecting aluminium.44 A new scheme of separ-ation of the metals of the iron, zinc, barium, and alkali groups inpresence of phosphates has been de~ised.4~ The cobalt-thiocyanatereaction for the detection of these ions has been in~estigated,~~and also the composition of the precipitate obtained by the actionof ferrocyanide on zinc salts in the presence of cobalt, utilised as acolour test for The compound Cs2[Ni(Se03),], formed byreaction of caesium chloride and sodium selenite with nickelis distinguished from the similar crystals given with magnesium salts,other than phosphate, by reaction with dirnethylgly~xime.~~Rapid and trustworthy methods for the detection of the alkaline-earth metals are recommended; 5O with sodium tungstate, bariumions give characteristic 0ctahedra.5~ The bromides of calcium,strontium, and magnesium are soluble in isoamyl alcohol, whilstthose of barium, sodium, and potassium are almost insoluble.52 Fur-ther details are given of the use of p-nitrobenzeneazoresorcinol as areagent for magnesium, 53 for which thiodiphenylcarbazide has alsobeen used.54 Magnesium and lithium do not interfere with thedetection of potassium as pi~rate,5~ and further work is recorded on*O I.M. KoIthoff, J . Amer. Chem. SOC., 1930, 52, 2222; A., 1011; compare4 * F. Feigl and H. J. Kapulitzas, Mikrochem., 1930, 8, 239; A., 1147;42 J . Dubsky and M. Kurag, Chem. Listy, 1929, 23, 496 ; A., 1929, 1414.43 G. Sensi and R. Testori, Ann. Chim. Appl., 1929,19,383; A., 1929,1413.44 H. Yagoda and H. M. Partridge, J . Amer. Chem. SOC., 1930,52,3579 ; A.,45 M. 0. Charmandarjan, 2. unc-tE. Chem., 1929,79,90; A., 183.4 6 I. M. Kolthoff, Mikrochem., 1930, 8, 176; A., 882.47 A. Schachkeldian, J . Russ. Phys. Chem. SOC., 1929, 61, 2217; A,, 563.48 A. Martini, Mikrochem., 1930, 8, 41 ; A., 566.49 L. Rosenthaler, ibid., p. 151; A., 881.50 P. Agostini and R. Abbiate, Ann. Chim. Appl., 1930, 20, 229; A., 1147.51 G. Denighs, Bull.SOC. Pharm. Bordeaux, 1929,67, 4 ; A., 53.62 H. Yagoda, J . Amer. Chem. Soc., 1930, 52, 3068; A., 1264.63 E. W. EngeI, ibid., p. 1812 ; A., 881 ; H. Leitmeier and F. Feigl, Tach.64 P. Agostini, Ann. Chim. Appl., 1930, 20, 235; A., 1147.66 E. R. Caley, J . Amer. Chem. Soc., 1930,52,953; A., 562.P. N. Das-Gupta, J . Indian Chem. SOC., 1929, 6, 627; A., 1929, 1412.Ann. Reports, 1929, 26, 190.P. RBy, 2. anal. Chem., 1929,79, 94; A., 182.1393.Min. Petr. Mitt., 1930, 40, 325; A., 1264212 ELLIS AND FOX:the use of zirconium sulphate as a reagent for potassium 56 and onthe triple acetate test for sodium.57Spot-tests for vanadium and tungsten 58 and for the preciousmetals 59 are described, as also the analytical application of catalyticreactions in the platinum group.60 Silver azide is dimorphous,crystallising either in needles or in plates.61 Molybdates give colourreactions with phenylhydrazine .62 and with potassium benzyl-xanthate.63 The general analytical behaviour of ekatantalum isde~cribed.6~Some general schemes for the detection of the principal anionshave been devised,65 including methods for anions containing thecyanogen group.66 Test-papers for carbonyl chloride are preparedfrom mixed solutions of dimethyl-p-aminobenzaldehyde and di-phenylamine.67 Various methods are proposed for the detection offluorine in rocks and mineral waters.68 Reactions for nitrites aregiven by upomorphine, 69 aminosulphonic acid, 70 and aqueous extractof walnut kernels.71 A silver nitrate-tannin reagent is reduced byeven traces of ammonia.72Feigl's azide-iodide reaction is applied as a test for sulphide-sulphur in minera1s,T3 and a comparison has been drawn of the5 6 R.D. Reedand J. R. Withrow, J . Amer. Chem. SOC., 1929,51,3238; A . ,6 7 V. P. Malitzky and V. A. Tubakaiev, Mikrochem., 1929, 7, 334; A , , 181.5 8 N. A. Tananaev and G. A. Pantchenko, J . Ruas. Phys. Chem. SOC., 1929,6@ N. A. Tananaev and K. A. Dolgov, ibid., p. 1377; A., 185; H. Holzer,6o F. L. Hahn, ibid., p. 77 ; A., 445 ; F. Feigl and P. Krumholz, Ber., 193061 R. Uzel, J . Czech. Chem. Comm., 1930, 2, 300; A., 1010.62 E. Montignie, Bull. SOC. chim., 1930, [iv], 47, 128 ; A., 313.63 S. L. Malowan, 2. anal. Chem., 1929, 79, 201; A., 153.65 P. Agostini, Ann.Chim. Appl,, 1929,19, 520; A., 311; idem, ibid., 1930,2Q, 112; A., 725; F. E. Raurich, Anal. Pis. Quim., 1930,28, 749; A., 1392.66 A. Schapovalenko, Ukrain. Chem. J . , 1929,4,303; A., 313; J.Russ. Phys.C'Jzem. SOC., 1929,61,2101; A . , 562; T. Pavolini, Ann. Chim. Appl., 1929,19,561 ; A . , 444.52; idem, ibid., 1930,52,2666; A., 1150.61, 1051 ; A., 54.Mikrochem., 1930, 8, 271; A., 1160.63, [B], 1917; A., 1394.A. von Grosse, J . Amer. Chem. SOC., 1930,52, 1742 ; A . , 883.67 A. Suchier, 2. anal. Chem., 1929, 79, 183; A., 181.68 I. P. Alimarin, ibid., 1930, 81, 8 ; A., 1143 ; H. Leitmeier and F. Feigl,Tsch. Min. Petr. Mitt., 1929, 4Q,6 ; A., 51 ; J. C. Gil, Anal. Fis. Quim. (Tech.),1929, 2'7, 141 ; A . , 51.F. Pavelka, Mikrochem., 1930, 8, 46; A., 442.70 P.Baumgarten and I. Marggraff, Ber., 1930,63, [B], 1019; &4., 880.7 1 P. Zywnev, 2. anal. Chem., 1930, 79, 389; A., 442.72 K. G. Makris, ibid., 81, 212; A., 1263.meier, Tsch. Min. Petr. Mitt., 1929, 40, 20; A,, 51.M. Niessner, Mikrochern., 1930, 8, 121 ; A., 879; F. Feigl and H. LeitANALYTICAL CHEMISTRY. 213sensitivity of various tests for traces of hydrogen ~ulphide.'~ Theformation of methylene iodide from iodoacetic acid and persulphatesserves as a delicate test for these salts,75 whilst hyposulphites give arose coloration with ammoniacal naphthol-yellow.76 A colour testfor silicate depends upon the formation of a complex silico-rn~lybdate.~~Quantitative.-Dichlorofluorescein is a suitable adsorption indicatorfor the argentometric titration of very dilute chloride solutions ; 78bromophenol-blue and bromocresol-purple may be used in titratingbromides or chlorides with mercurous nitrate.79 The effect of thepresence of various kations in this method has also beeninvestigated.80The pH of the colour change of some vegetable indicators is recorded,81as also the sensitivity and stability of phthaleins and sulphone-phthaleins to alkaliYs2 and a stable, sensitive starch indicator.s3Several other papers deal with indicators.84 Some aspects of thecolorimetric pn determination are discussed.85Borax and mercuric oxideYsG sodium ~ x a l a t e , ~ ~ potassium titaniumoxalate,s8 and various other compounds 89 have been examined asstandards in volumetric analysis, and also the processes occurring inE.C. Truesdale, Id. Brig. Chm. (Anal.), 1930,2,299; A., 1144.G. Panopoulos and A. Petzetakis, Chem.-Ztg., 1930, 54, 310; A.,736.7 6 E. E. Jelley, Analyst, 1930, 55, 34; A., 181.77 F. Feigl and H. Leitmeier, Tach. Min. Petr. Mitt., 1929, 40, 1; A.,I. M. Kolthoff, W. M. Lauer, and C. J. Sunde, J. Amer. Chem. SOC., 1929,62.51,3273 ; A., 60.ID L. von Zombory, 2. anorg. Chem., 1929,184,237 ; A., 64.N. P. Rudenko, J. Ruse. Phya. Chem. SOC., 1930,62,605; A., 1010.A. del Campo, A. Rancaiio, and G. Subero, Anal. Pis. Quim., 1929, 27,687; A., 60; N. P. Sobyanin and S. G. Saakov, J . Chem. Id. Russia, 1929,6, 736; A., 1143; 0. B. Pratt and H. 0. Swartout, Science, 1930, 71, 486;A., 1142.82 A. Thiel, Monatsh., 1929, 53 and 54, 1008 ; A,, 1929, 1410.8s M.S. Nichols, Id. Eng. Chern. (And.), 1929, 1, 216; A., 1929, 1411.84 H. Eichler, 2. anal. Chem., 1929, 79, 81; A., 181; F. L. Hahn, ibid.,1930, 80, 321; A., 1009; J. F. Reith, Phurm. WeekbZad, 1929, 66, 1097;A., 181; B. Samdahl, J . Pharm. Chim., 1930, [viii], 11, 8; A., 343; E. E .Harris, H. W. Haugen, and B. E. Fahl, J . Amer. Chem. SOC., 1930, 52, 2397;A., 1009; A. H. Johnson and J. R. Green, Id. Eng. Chem. (Anal.), 1930, 2,2; A., 660.86 S. F. Acree and E. H. Fawcett, ibicE., p. 78; A., 660; L. Wolf, 2. Elektro-chem., 1930,36,803 ; A., 1391.86 N. A. Lazarkevitsch, Ukrain. Chem. J., 1929,4,405 ; A., 309 ; R. Biazzoand C. Chines, Ann. Chirn. Appl., 1930,20,258; A., 1143.U.S. Bur. Stand., 1930, Circ.381; A,, 726.W. M. Thornton, jun., and R. Roseman, Amer. J . Sei., 1930, [v], 20,Vasterling, P h m . Ztg., 1930, 75, 68 ; A., 182.14; A., 1009214 ELLIS AND FOX:thiosulphate solutions on keeping.9* The iodine monochloride end-point is used in the titration of iodide 91 and arsenite; 92 bromo-iodometric methods are given for urea, ammonium salts, formic acid,and iodides,9* and some alkalimetric titrations describedSg3 Animproved method of determining water in micas has been devised,94and also a more general process involving the use of calcium h ~ d r i d e . ~ ~The sensitivity of various colorimetric reactions of iron, nickel,copper, and silver has been ascertained by an electrochemicalmethodYg6 and the methods of indicating the sensitivity of analyticalreactions 97 and methods of indirect analysis are discu~sed.~~Aluminous silicates may be attacked by sintering with smallamounts of sodium carbonate,99 and sulphide minerals by fusion withsodium thiosulphate.1 Other papers of general interest deal withthe segregation of samples for analysis,2 with the effect of variousfactors on the separation of metals by fractional pre~ipitation,~with modern trends in analytical chemisfry,4 and with analyticalseparations by ether e~traction.~Several volumetric and colorimetric methods of determiningcopper are described, reagents in the latter class including nitroso-F.L. Hahn and H. Clos, 2. anal. Chem., 1929,79, 11 ; A , , 51 ; E. Schulek,ibid., 1930, 80, 190; A., 725; F. H. Campbell and F.J. Watson, Chem. Eng.Min. Rev., 1930, 22, 340; A . , 1144.91 E. H. Swift, J . Amer. Chem. SOC., 1930, 52, 894; A., 561.92 E. H. Swift and C. H. Gregory, ibid., p. 901; A., 561.92a J. H. vm der Meulen, Chem. Weekbkzd, 1930,27,550, 558; A . , 1392.93 C . J. van Nieuwenburg, ibid., pp, 143, 158, 186, 206; A., 879; idem,ibid., p. 174; A., 1142; W. Poethke and P. Manicke, 2. anal. Chem., 1929,79,241; A., 311; 0. Schewket, Biochem. Z., 1930, 224, 325; A . , 1392.94 I(. Wiskont and I. Alimarin, Z . anal. Chem., 1929,79,271; A . , 310.95 0. Notevarp, ibid., 1930, 80, 21 ; A., 560.96 H. Fritz, ibid., 1929, 78, 418; A., 1929, 1414.97 F. L. Hahn, Mikrochem., 1930, 8, 75 ; A., 441 ; K. Heller, ibid., p. 141 ;98 0. Liesche, 2. angew. Chem., 1929,42, 1109; A., 310; P.Fuchs, 2. anal.A. N. Finn and J. F. Klekotka, BUT. Stand. J . Res., 1930, 4, 809; A.,E. Donath, Chem.-Ztg., 1930, 54, 78; A., 311.A., 879.Chem., 1930,79, 417 ; A., 441 ; 0. Liesche, ibid., 81, 273.1010.a G. F. Smith, L. V. Hardy, and E. L. Gard, Ind. Eng. Chem. (Anal.), 1929,a 0. Ruff, Oesterr. Chem.-Ztg., 1929, 32, 199; A . , 180.1, 228; A., 1929, 1409.H. H. Willard, Ind. Eng. Chem. (Anal.), 1930,2, 201 ; A., 1142 ; L. Moser,0. von Grossmann, Chem.-Ztg., 1930,54, 402; A., 879.A. T. Kiichlh, Rec. trav. chim., 1930, 49, 151; A., 313; W. Orlik and W.Tietze, Chem.-Ztg., 1930, 54, 174; A., 444; M. Lora y Tomayo, And. Pis.Quirn., 1930, 28, 63; A., 444; J. Golse, Bull. SOC. chim., 1930, [iv], 47, 655;A., 1148.Monatsh., 1929,53 and 54, 39; A., 1929, 1410mALYTICAL CHEMX3TRY. 215chromotropic acid,' urolobin,8 sodium diethyldithi~carbamate,~and salicylate-benzidine.9" Copper may be weighed in the form ofits compound with salicylaldoximelo and as the complex[HgI,](Cu en,); 1b the precipitation of copper by boiling withthiosulphate has been critically examined,ll and a rapid method isdescribed for converting cupric into cuprous sulphide.12Precipitation of lead as sulphate yields accurate results only whenthe solution is free from ferric and potassium salts, chlorides, andbromides ; l3 the chromate method has also been investigated.14Sodium bismuthate may be evaluated by a gasometric method ; l6bismuth can be quantitatively precipitated as the complex[BiI,](Co en,)I l6 or by means of selenious acid, which also precipit-ates titanium.17Cadmium may be weighed as the hydrated oxalate l8 or as thecompound Cd12,2[(CH,),N,,C,H,]I.19Cupferron precipitates mercurous ions quantitatively from nitricacid solutions ; 2o mercuric salts are reduced to mercurous chlorideby hypophosphorous acid in presence of hydrochloric acid andhydrogen peroxide 21 or to metal by hydrazine or stannous chloride.22Studies of the Gutzeit method for arsenic have been made.23 Aniodometric determination of quinquevalent antimony is described,24E.Cherbuliez and S. Ansbacher, Helv. Chim. Acta, 1930,13, 187; A., 564.A. Emmerie, Chem. Weekblad, 1930, 2'7, 552; A., 1393.T. Callan and J. A. R. Henderson, Analyst, 1929, 54, 650; A., 53.OaA.B. Schachkeldian, J . Appl. Chem. Russia, 1929, 2, 475; A., 444.lo F. Ephraim, Ber., 1930,63, [B], 1928; A., 1393.IOU G. Spacu and G. Suciu, 8. anal. Chem., 1929, 79, 329; A., 1929, 1413.l1 J. Majdel, ibid., p, 38; A., 53.l2 F. L. Hahn, Ber., 1930, 63, [B], 1616; A., 1011.l9 Z . Karaoglanov and B. Sagortschev, 8. anal. Chem., 1930, 81, 275;l4 Z. Karaoglanov and B. Sagortschev, loc. cit.; 33. Jones, Analyst, 1930,l6 T . Somiya and K. Kawai, J . SOC. Chem. I d . Japan, 1929, 32, 2 4 9 ~ ;l6 G. Spacu and G. Suciu, 2. anal. Chern., 1929,79,196; A., 184.l7 R. Berg and M. Teitelbaum, 2. anorg. Chem., 1930,189,101 ; A., 566.l8 J. Dick, 8. anal. Chem., 1929, 78, 414; A., 1929, 1412.lo V. Evrard, Natuurwetensch. Tijds., 1929, 11, 191 ; A., 182.2o A.Pinkus and (Mlle.) M. Kntzenstein, Bull. SOC. chim. Belg., 1930, 39,A., 1393 ; Z . Karaoglanov, Ber., 1930,63, [B], 597 ; A., 563.55, 318; A., 881.A., 184.179; A,, 1011.E. Cattelain, J . Pharm. Chim., 1930, [viii], 11, 580; A., 1148.2a H. H. Willard and A. W. Boldyreff, J . Amer. Chem. SOC., 1930, 52, 569;A., 444 ; Jean, Bull. SOC. Pharm. Bordeaux, 1929,67,239 ; A., 1148.23 A. J. Lindsey, AnaEyst, 1930, 55, 503; A., 1263; J. W. Barnes andC. W. Murray, Id. Eng. Chem. (Anal.), 1930, 2, 29; A., 562; F. Martin andJ. Pien, Bull. SOC. chim., 1930, [iv], 47, 646; A,, 1144.p4 L. Szebell6dy, 8. anal. Chem., 1930, 81, 36; A., 1150216 ELLIS AND FOX:and a colorimetric method for tin, utilising stannic sulphide.25Arsenic, antimony, and tin may be separated by successive distil-lations under appropriate conditions ; 26 in the separation of lead andantimony sulphides by digestion with sodium sulphides, sufficientpolysulphide must be present to convert the antimony into thio-antimonate.27It has been found that aluminium hydroxide, precipitated fromalkaline solutions by carbon dioxide, is easily washed and filtered ; 28the hydroxide should be ignited a t about 1300" to yield a non-hygroscopic oxide.29 Blum's method can be applied to alumino-borosilicates without the necessity of previous removal of boron.30Aluminium is quantitatively precipitated by hydrazine arbo on ate,^^whereby separation from iron 32 and manganese 3~ may be effected ;this precipitant has also been used for beryllium.33 Precipitation bymeans of " fusible white precipitate " has been extended to a numberof separ~ttions.~~ In the determination of aluminium by means ofaurintricarboxylic acid, maximum colour intensity is attained a tpH 4.35 Some volumetric methods for iron are given; 36 iron andmanganese may be separated from aluminium and phosphate bymeans of sodium hydroxide and hydrogen per0xide.~7 Ortho-phosphates do not interfere with the colour formation of ferric thio-cyanate as much as pyroph~sphates.~~ A rapid iodometric deter-mination of chromium in the presence of organic substances has beende~ised.~9 Titanium is quantitatively precipitated from feebly acidor ammoniacal tartrate solutions by 8-hydroxyquinoline ; 40 details25 R.Hamsen, Chem.-Ztg., 1930, 54, 143; A., 445.26 H.Biltz, 2. anal. Chem., 1930, 81, 82; A., 1144.27 Idem, ibid., p. 81 ; A., 1147.28 R. Fricke and K. Meyring, 2. anorg. Chem., 1930,188, 127; A , , 727.2s W. Miehr, P. Koch, and J. Kratzert, 2. angew. Chem., 1930, 43, 250;so 0. V. Krasnovski, 2. anal. Chem., 1929,79,175; A., 183.s1 A. Jilek and J. Lukas, J . Czech. Chem. Comm., 1930, 2, 63; A., 444.Idem, ibid., p. 161; A., 727.3ta Idem, ibid., p. 113 ; A., 564.3s A. Jilek and J. Kob, ibid., p. 571 ; A., 1393.s4 B. golaja, 2. anal. Chem., 1930, 80, 334; A., 1012; B. Solaja, M. Kranj-Eevib, and M. Kockar, Arhiv Hemiju, 1930, 4, 136; A , , 1149.35 0. B. Winter, W. E. Thurn, and 0. D. Bird, J . Amer. Chem. SOC., 1929,51,2721 ; A., 1929, 1413.36 F.L. Hahn and H. Clos, 2. anal. Chem., 1929,79,26; A., 54; L. Szebel-16dy,ibid., 1930,81,26; A., 1149; idem,ibid.,p. 97; A., 1149.37 I. S. Teletov and N. N. Andronikova, Ukrain. Chem. J . , 1929, 4, 341;A., 313; 2. anal. Chem., 1930,80,351; A., 1012.38 G, W. Leeper, Analyst, 1930, 55, 370; A., 1012.so F. Feigl, I(. Klanfer, and L. Weidenfeld, 2. anal. Chem., 1930, 80, 5 ;40 R. Berg and M. Teitelbaum, ibid., 81, 1; A., 1160.A., 564; W. Biltz, ibid., p. 370; A., 1148.A., 665ANALYTICAL CHEMISTRY. 217are given for the separation of titanium from other metals 41 and fora colorimetric method of determining this element with gallic acid.42The precipitation of manganese by von Knorre's persulphatemethod has been examined from the gravimetric 43 and volumetric 44standpoint, as also the iduence of cobalt on the bismuthate methodfor manganese.45 Two iodometric methods for zinc are described.46Colorimetric methods of determining cobalt are given ; 47 theinsoluble hydrazine-thiocyanate compounds may be employed forthe determination of cobalt, nickel, and cadmium.48 Phenylthio-hydantoic acid has been further investigated as a precipitant forcobalt,49 and two volumetric methods for cobalt are described.50Small amounts of calcium may be determined after separation astriple nitrite with potassium nickelonitrite 5l or as tungstate. 52Various aspects of the oxalate method for calcium have beenconsidered and it is shown that the oxalate may be converted quantit-atively into the carbonate a t 450" to 500".This observationprovides a great simplification in the determination of calcium. 53Barium chloride can be titratect in neutral or acid solution with alkalisulphate with sodium rhodizonate as indicator.The conversion of magnesium ammonium phosphate into pyro-phosphate is stated to occur below 480°, thus allowing the use of41 L. Moser, K. Neumayer, and K. Winter, Monatsh., 1930, 55, 85; A.,42 P. N. Das-Gupta, J . Indian Chern. SOC., 1929,6, 855; A., 566.p3 J. Majdel, 2. anal. Chem., 1930, 81, 14; A., 1149.44 I . M. Kolthoff and E. B. Sandell, Ind. Eng. Chem. (Anal.), 1929, 1, 181 ;4 5 T. Somiya, J . SOC. Chem. Ind. Japan, 1930,33,255~; A., 1265.46 H. A. Page1 and 0. C. Ames, J . Amer. Chem. SOC., 1930, 52, 3093; A,,1264; R.Lang, 2. anal. Chern., 1929,79,161; A., 182.4 7 A. Lieberson, J . Amer. Chem. SOC., 1930,52,464; A., 445; E. S . Tomula,Suomen Kern., 1929,2, 72; A., 565; A. Blanchetibre and J. M. Pirlot, Compt.rend. SOC. Biol., 1929, 101, 858; A., 1393; M. Delaville, ibid., p. 1082; A.,1393 ; W. Heinz, 2. anal. Chem., 1929,78,427 ; A., 1929,1414.4a P. B. Sarkar and B. K. Datta-Ray, J . Indian Chern. SOC., 1930, 7, 251;A., 882.4s V. Cuvelier, Natuurwetensch. l'ijds., 1929, 11, 131 ; A., 1929, 1414.727.A., 1929, 1414.S. Glasstone and J. C. Speakman, Analyst, 1930, 55, 93; A., 445; A. A.Vaasiliev, 2. anal. Chem., 1929, 78, 439; A., 1929, 1414.s1 A. Astruc and M. Mousseron, Compt. rend., 1930,190, 1558; A., 1011.62 A. Astruc, M. Mousseron, and (Mlle.) N.Bouiasou, ibid., p. 376 ; A., 443 ;M. Mousseron and (Mlle.) N. BOU~SSOU, B d l . 80c. Chim. biol., 1930, 12, 482;A., 1011.63 H. H. Willard and A. W. Boldyreff, J . Amer. Chem. SOC., 1930,52, 1888;A., 881 ; J . T. Dobbins and W. M. Mebane, ibid., p. 1469 ; A., 726 ; M. Stiller,Chern.-Ztg., 1930, 54, 422; A., 1147; Z. Herrmann, 2. anorg. Chem., 1929,184, 289 ; A., 62.64 R. Strebinger and L. von Zombory, 2. anal. Ohem., 1929, 79, 1; A., 53218 ELLIS AND FOX:sintered-glass crucibles.55 On the other hand, the results of acomprehensive inquiry into the methods of obtaining Mg,P,Odemonstrate that a certain concentration of ammonium salts mustbe observed. It is further shown that for accurate work ignition toconstant weight a t 1100" is desirable.Even at 1000" constant weightresults slowly, especially with large precipitates, while a t 1200" thereis a definite loss of weight and low results are obtained. The observ-ation is made that it is more difficult to obtain constant weight indeterminations of magnesium than in determinations of phosphorus. 56The alkali precipitation method for determining magnesium has beeninvestigated. 57The triple acetate method for sodium 58 and the cobaltinitritemethod for potassium 59 continue to attract attention. Othermethods for the latter metal utilise the per-rhenate,60 and triple leadcobaltinitrites. 61The precipitation of indium and its separation from various othermetals are described.62 Precipitation with camphoric acid affords aseparation of gallium from numerous other metals ; 63 three methodsare given for the separation of gallium and alumini~rn.~~ Uraniummay be determined colorimetrically with gallic acid,65 or gravi-metrically following treatment with tannic acid 66 or with 8-hydroxy-quinoline ; 67 the latter reagent also precipitates thorium from aceticacid solution.Ignition of lanthanum oxalate at 450" results in the65 S. S. Miholib, J., 1930, 200; A., 443.6 6 J. J. Hoffman andG. E. F. Lundell, U.S. Bur. Stand. J . Res., 1930, 5,279.67 T. Maeda and R. SyBzi, Sci. Papers Inst. Phys. Chem. Res. Tokyo, 1930,13, 185; A., 881.5B H. H. Barber and I. M. Kolthoff, J . Amer. Chem. Soc., 1929, 51, 3233;A., 52; E. R. Caley, Ind. Eng. Chem. (Anal.), 1929, 1, 191; A., 1929, 1412;idem, J .Amer. Chem. SOC., 1930, 52, 1349; A., 726; E. Kahane, J . Pharm,Chim., 1930, [viii], 11, 425; A., 880; idem, Bull. SOC. chim., 1930, [iv], 47,382; A., 726.6s L. Bonneau, ibid., 1929, [iv], 45, 798; A., 49; A. Vassiliev and N.Matveev, 2. anal. Chem., 1930, 81, 106; A., 1146.6O H. Tollert, Naturwiss., 1930,18, 849 ; A., 1392.P. S. Sergeenko, Ukrain. Chem. J., 1930, 5(Sci.), 113; A., 1146; V. I.Tovarnitzki and P. S. Sergeenko, Zhur. Sakharnoi Prom., 1928, 2, 228; A , ,52.L. Moser and F. Siegmann, Monatsh., 1930, 55, 14; A., 564.63 S. Ato, Sci. Papers I w t . Phys. Chem. Res. Tokyo, 1930, 12, 225; A.,64 Idem, ibid., 14,35; A., 1264.65 R. N. Daa-Gupta, J . Indian Chem. SOC., 1929,6, 763; A., 183.B6 Idem, ibid., p. 777; A., 183.67 F.Hecht and W. Reich-Rohrwig, Monatsh., 1929, 53 and 54, 596; A.,564.1929, 1415ANALYTICAL CHEMISTRY. 219formation of a basic carbonate.68 Further studies are recorded ofthe determination of zirconium and beryllium as phosphate^,^^ andof the analytical chemistry of tantalum, niobium, and their mineralassociates.70 Precipitation with tannin and antipyrine permits theseparation of tungsten from various metals,71 with arsenic acid fromvanadium,72 and with benzidine from ar~enates.~3 A rapid reaction,catalysed by phosphates, occurs between vanadyl sulphate andpotassium iodate in hot alkaline solution.7*Osmium and ruthenium may be separated through the differingsolubility in aqueous alcohol of their complexes with strychnine. 75Ruthenium may be quantitatively precipitated by sodium bicarbon-ate.76 Minute quantities of gold may be separated from much iron,lead, and copper by deposition on silk; 77 volumetric methods aregiven for small amounts of silver.78Polonium may be separated from radium-E and -D, and radium-Efrom radium-D, by deposition on silver and nickel respectively,even when present in unweighable amounts.79Further work has been carried out on rubidium chlorostannate ; 8oanhydrous dioxan 81 or acetone serves to extract lithium chloridefrom certain other chlorides. Small quantities of lithium may bedetermined nephelometrically as stearate 83 or centrifugally asphosphate.84A study has been made of the separation of thallium from ter-and quadri-valent metals.85Volumetric methods for determining thiocyanate by means of68 H.J. Backer and K. H. Klaassena, 2. anal. Chem., 1930, 81, 104; A.,69 0. Ruff and E. Stephan, 2. amrg. Chem., 1929,185, 217; A., 184.70 W. R. Schoeller and H. W. Webb, Analyst, 1929, 54, 704; A., 184.71 L. Moser and W. Blaustein, Monatsh., 1929, 52, 351 ; A , , 312.72 A. Jilek and J. Lukas, Chem. Listy, 1930, 24, 73; A., 565.73 Idem, ibid., p. 320; A., 1265.74 J. B. Rarnsey and A. Robinson, J . Amer. Chem. SOC., 1930, 52, 480; A.,7 5 S. C. Ogburn, jun., and L. F. Miller, ibid., p. 42; A., 313.76 R. Gilchrist, Bur. Stand. J . Res., 1929, 3, 993; A., 446.7 7 J. Donau, Milcrochem., 1930, 8, 267; A., 1160.7 8 J. Golse, Bull. SOC. chim., 1930, [iv], 47, 760; A,, 1264; W. Holwech,79 0.Erbacher and K. Philipp, 2. physikal. Chem., 1930,150,214; A., 1394.eo E. Burkser, W. L. Milgevskaja, and R. W. Feldmann, 2. anal. Chem.,81 A. Sinke, ibid., p. 430; A., 1146.*a M. H. Brown and J. H. Reedy, I d . Eng. Chem. (Anal.), 1930, $3, 304;83 E. R. Caley, J . Amer. Chem. SOC., 1930,52,2764; A., 1146.84 B. Brauner, J . Czech. Chrn. Comm., 1930,2,442; A,, 1146.86 L. Moser and W. Reif, Mo&h., 1929,52,343; A., 312.1148.445.Tidsskr. Kjemi Berg., 1930, 10, 78; A., 1392.1930,80,264; A., 881.A,, 1146220 ELLIS AND FOX:permanganate,ss hypobr~mite,~~ and iodine or iodate 88 have beeninvestigated, whilst oxidation for gravimetric purposes may beeffected by hydrogen peroxide in hot alkaline sol~tion.~g Neutral5% potassium chlorate solution, whilst hardly affecting hydrogensulphide, oxidises sulphur dioxide quantitatively when air con-taining these gases is passed through it.90 Conditions for thereduction of sulphate to sulphide by means of calcium hydride arepre~cribed,~~ and a similar reduction by hydriodic acid is followed bycolorimetric comparison by Caro’s reaction for small quantities ; 92reduction by zinc dust is applied to the determination of sulphate inthe presence of aluminium The precipitation of bariumsulphate under varying conditions has been studied, and the resultingprecipitates have been examined microscopically.9* Persulphate isrecommended as a standard oxidising agent in iodometric determin-ations.95The influence of phosphates and of iron on the determination ofsilica by Di6nert and Wandenbulcke’s colorimetric method has beenstudied,ge as also the alkalimetric titration of fluosilicic and fluoboricacids .97A number of volumetric methods for determining cyanides arediscussed; 98 ferric chloride is applied as external indicator in thetitration of ferrocyanide with zinc.99 Perchloric acid is recommendedfor liberating carbon dioxide from carbonates, a special apparatusbeing described.lSeveral papers have appeared dealing with the determination of86 J.Golse, Bull. Soc. Pharm. Bordeaux, 1929, 67, 226; A., 1144; B.Reinitzer and H. Pollet, 2. anal. Chem., 1930,81,286; A., 1391 ; K. Schroder,ibid., p. 308 ; A., 1392.81 J. Golse, Bull. SOC. Pharm. Bordeaux, 1929, 67, 221; A., 1144.88 H.A. Page1 and 0. C. Ames, J . Amer. Chem. SOC., 1930, 52, 2698; A.,8s F. Schuster, 2. anorg. Chem., 1930,186, 253; A., 442.$0 V. G. Gurevitsch, J . Russ. Phys. Chem. SOC., 1930, 62, 111; A., 879.91 W. F. Caldwell with F. C. Krauskopf, J . Amer. Chem. SOC., 1929, 51,$2 I. S. Lorant, 2. physiol. Chem., 1929,185, 245; A., 181.93 H. Ginsberg, 2. angew. Chern., 1930,43,21; A., 441.*C S. Popov and ‘E. W. Neuman, Id. Eng. Chem. (Anal.), 1930, 2, 46; A.,S5 C. V. King and E. Jette, J . Amer. Chem. SOC., 1930, 52, 608; A., 441.96 L. A. Thayer, Id. Eng. Chem. ( A n d ) , 1930,2, 276; A., 1145.*7 E. F. Kern and T. R. Jones, Amer. Electrochem. SOC., May, 1930; A.,0. Reer, Tidsskr. Kjemi Berg., 1929, 9, 127 ; A., 52 ; M. Lora y Tomayo,1144.2936; A., 1929,1411.561.880.Anal.Pis. Quim., 1930, 28, 724; A,, 1392.99 P. F. Felkers, Chem. Weekblad, 1930,27, 209; A., 882.1 C. A. Jacobson and J. W. Haught, Ind. Eng. Chem. (Anal.), 1930,2,334;A., 1146ANALYTICAL CHEMISTRY. 221fluorideY2 of perchlorate,3 the halogenides,* and the phosphorus acidsgenerally. 5Reduction to ammonia is applied to the determination of nitratesand nitrites,6 and of nitrogen itself in gaseous mixtures.' Ferricchloride may be used as indicator in the titration of soluble azideswith sodium nitrite.8Organic Analysis .Qualitative.-M. Wagenaar 9 describes microchemical reactions of(a) strychnine, ( b ) brucine, ( c ) hydrastine, (d) berberine, (e) acoilitine,(f) cytisine, (9) cocaine, and (h) veratrine ; similar tests are describedfor codeine and dionine,lO antifebrin and phenacetin,ll antipyrine,12homatropine and novatropine,l3 thiophen,l* strychnine,15 ephe-E. CarriAre and Janssens, Compt.rend., 1930, 190, 1127; A., 879; E.Carrihre and Rouanet, ibid., 1929, 189, 1281 ; A., 180; J . Casares, Anal. Pis.Qudm. (tech.), 1929,27,290; A., 180; J. G. Fairchild, J. Washington Acad. Sci.,1930, 20, 141 ; A., 726.K. Heller, K. Willingshofer, and B. Sadrawetz, Z. anal. Chem., 1929, 79,256; A., 310; H. H. Willard and J. J. Thompson, I d . Eng. Chem. (Anal.),1930,2,272; A., 1143.R. Lang and J. Messinger, Ber., 1930, 63, [B], 1429; A., 1010; R. G.Turner, J . Amer. Chem. SOC., 1930,52,2768 ; A., 1143 ; S. V. Gorbatschev andI. A. Kasatkina, Z. anorg. Chem., 1930, 191, 104; A., 1143; K.Kuchler,Chem.-Ztg., 1930, 54, 682; A., 1143; H. Szancer, Arch. Pharm., 1930, 268,263 ; A., 726 ; G. G. Longinescu and T. I. Pirtea, Bull. Acad. Sci. Roumuine,1929, 12, No. 7-10, 57; A., 661; R. H. Iclein, Analyst, 1930, 55, 192; A.,561 ; R. Hofmann, Pharm. Zentr., 1930,71,18; A,, 310; H. Ditz and R. May,Z . anal. Chem., 1930,79, 333; A., 310; idem, ibid., p. 371; B., 417.H. EgnBr, Svensk Rem. Tidskr., 1929,4l, 240; A., 1929,1412; T. Kuttnerand L. Lichtenstein, J. Biol. Chem., 1930,88,671; A., 725; K. Hinsberg andD. Laszlo, Biochem. Z., 1930,217,346; A,, 562; L. Brestak and 0. A. Dafert,2. angew. Chem., 1930, 43, 216; A,, 662; A. Dunaiev, Z. anal. Chem., 1930,80,252; A., 880; R. Zinzadze, Z. Pjlanz. Dung., 1930,16, [A], 129; A., 726;A. P.Dunaev, Min. SU~T. Tzvet. Met., 1929, 424; A,, 1010.K. Woidich, Oe~terr. Chem.-Ztg., 1929, 32, 183; A., 1929, 1411.S. N. Blumstein, Z. anal. Chem., 1930,79,324 ; A., 3 11.* J. F. Reith and J. H. A. Bouwman, Pharm. Weekblad, 1930,67,475; A.,880.Pharm. Weekblad, 1929, 66, ( a ) p. 1073; (b) p. 1170; 1930, 67, (c) p. 57,( d ) p. 77, (e) p. 165, (f) p. 205, (9) p. 229, ( h ) p. 393 ; A,, 98, 229, 353, 353, 486,629, 623, 796, respectively.lo G. de Haas, ibid., p. 608; A., 937.l1 L. Ekkert, Pharm. Zentr., 1930, 71, 179; A., 629.l2 Idem, ibid., p. 180; A,, 617.l3 Idem, {bid., p. 641 ; A., 1461.l4 Idem, ibid., p. 625; A., 1460.l6 J . C. Ward and J. C. Munch, J . Amer. Pharm. Assoc., 1930, 19, 954; A.,1456222 ELLIS AND FOX:drine,l6 barbituric acid derivatives,l' glycine,18 cysteine,lg pyridine,20isopropyl alcohol ,21 acetone and formaldehyde ,22 a-napht h01,~~Michler's ketone,24 mono-alkyl- and -aryl-arsinic acids,25 adrenalineF6and various compounds of pharmaceutical interest .27 Rufianic acidprecipitates many organic bases,Z8 but the compounds with thealkaloids are all very similar in appearance ; 29 other precipitantsfor alkaloids are described.30For purposes of identification, derivatives are described ofvarious alcohols with 4'-iododiphenyl-4-crrbimide 31 and with3 : 5-dinitrobenzoyl chloride,32 of organic acids with p-phenyl-phenacyl bromide,33 of aldehydes and ketones with 2 : 4-dinitro-phenylhydra~ine?~ of aldehydes with hippuric of arylaldehydes with indandione,36 of nitriles with magnesium phenylof mercaptans with mercuric bromide, with 3 : 5-dinitro-benzoyl chloride, and with 3-nitrophthalic anhydride,38 and of tertiaryamines with benzyl chloride and with methyl p-toluene s~lphonate.~~l6 J.Sivadjian, J. Pharm. Chim., 1930, [viii], 12, 266; A., 1460.l7 L. van Itallie and A. J. Steenhauer, Pharm. Weekblad, 1930, 67,977 ; A.,1460; G. Deniges, Bull. SOC. Pharm. Bordeaux, 1929,67, 165; A., 788.la W. Zimmermann, 2. physiol. Chem., 1930, 189, 4 ; A., 897.lo R. Fleming, Biochem. J., 1930, 27, 965; A., 1420.'O J. V. Kulikov and T. N. Krestovosdvigenskaja, 2. anal. Chem., 1930, 79,21 H. Leffmann and C. C. Pines, Bull. Wagner Inst. Sci., 1929,4,47 ; A., 318.Idem, ibid., p. 39; A., 1929, 1425; L. Kofler and H.Hilbck, Mikrochem.,462 ; A., 489.1930, 8, 117; A., 940.as 0. Carletti, Biorn. Chim. I d . Appl., 1930,12, 178; A., 908.9' H. Gilman, 0. R. Sweeney, and L. L. Heck, J. Amer. Chem. SOC., 1930,as J. Golse, Bull. SOC. Pharm. Bordeaux, 1929, 67, 84; A., 442.26 H. Bierry and B. Gouzon, Compt. r e d . , 1930,190, 1239; A., 941.17 L. Rosenthaler, Pharm.-Ztg., 1930, 75, 650; A., 941; C. van Zijp,W. Zimmermann, 2. phy&ol. Chem., 1930,188, 180; 189, 155; A., 941,2o L. Rosenthaler, Pharm. Zentr., 1930,71,561; B., 1090.52, 1064; A., 778.Pharm. Weekblad, 1930,67, 189; A., 629.1170.Idem, Amer. J . Phurm., 1929, 101, 724; A., 98; G. D. Lander, Analyst,31 S. Kawai and K. Tamura, Sci. Papers Inst. Phys. Chem. Res. Tokyo,32 G. B. Malone and E.E. Reid, J. Amer. Chem. SOC., 1929,51, 3424; A., 58.33 N. L. Drake and J. Bronitsky, ibicE., 1930, 52, 3715; A., 1436.34 C. F. H. Allen, ibid., p. 2955; A., 1175.56 W. M. Rodionov and A. J. Korolev, 2. angew. Chem., 1929,42,1091; A.,36 M. V . Ionescu, Bull. SOC. chim., 1930, [iv], 47, 210; A., 606.37 R. L. Shriner and T. A. Turner, J. Amer. Chem. SOC., 1930, 52, 1267;a* C. S. Marvel, E. W. Scott, and K. L. Amstutz, ibid., p. 3638; A., 199.1930, 55, 474; A., 1304.1930,13, 260, 270; A., 1159.194.A., 777. 88 E. Wertheim, ibid., 1929, 51, 3661 ; A., 192ANALYTICAL CHEMISTRY. 223The formation of aniline formate serves to identify formic acid:*whilst several tests for acetic acid are given.41 Acids, includinglactones and anhydrides, may be distinguished from phenols bydistillation with zinc dust in a current of hydrogen,& and neutraltartrates and citrates from t’he acid salts by means of ammoniummetavanadate .43Colour reactions of the sugars have been investigated,a as havealso derivatives suitable for identification of 6-ketorhamnonic acid.45Nascent iodine gives colorations with certain aromatic a m i n e ~ .~ ~&uantitatiue.-Further examination has been made of possiblesources of error in organic elementary analysis.4’ Investigations onthe elementary analysis of organic compounds may be reviewedunder the following heads : carbon and hydrogenf8 nitrogen+9halogens generally,50 and iodine in particular, especially whenpresent in small amount,51 sulphur,52 arsenic,53 and mercury.5p Im-40 M. Masriera, Anal. Fie. Quim., 1930, 28, 916 ; A., 1405.41 D. Kriiger and E. Tschirch, Chem.-Ztg., 1930, 54, 42; A., 357; Mibo-chem., 1929, 7, 318; A., 192; Ber., 1929, 62, [B], 2776; A., 62; K. Serke,Apoth.-Ztg., 1929, 44, 1018; A., 489.42 A. W. van der Haar, Rec. trau. chim., 1929,48, 1170; A., 62.48 L. Rossi, Quim. e Id., 1929, 8, 113; A., 357.44 H. Szancer, Pharm. Zentr., 1929, 70, 645, 663, 665; A., 1929, 1426;46 E. VotoEek and S. Malachta, Anal. Pis. Quim., 1929, 27, 494; A., 66.46 W. Ruziczka, Z . anal. Chem., 1930, 80, 185; A., 903.47 J. Lindner and F. Hernler, Ber., 1930, 83, [B], 949, 1123, 1396, 1672;A., 726, 940, 1031, 1198.4a A. Boivin, Bull. SOC. Chim. biol., 1929,11, 1269 ; A., 442 ; K. Lindenfeld,Rocz.Chem., 1930,10, 84; A., 489; E. V. Zappi and A. Manini, Anal. Asoc.Quim. Argentina, 1929, 17, 234; A., 940; M. Nicloux, Compt. rend. SOC. Biol.,1929,102,693 ; A., 1392 ; S . Avery and D. Hayman, Ind. Eng. Chem. (Anal.),1930, 2, 336; A., 1198; J. Meyer and Tischbierek, Z . anal. Chem., 1930, 80,341 ; A , , 940.G. Dorfmiiller, 2. Ver. deut. Zucker-Id., 1930, 80, 407; A., 1166;F. C . Koch, J. Biol. Chem., 1929,84, 601 ; A., 101 ; B. Flaschentrliger, Mibo-chem., 1930, 8, 1; A., 489; E. Zunz, Ann. SOC. Zymol., 1929,1, 236; A., 489.6o J. J. Thompson, J. Amer. Chem. SOC., 1930, 52, 3466; A., 1303; P. W.Robertson, ibid., p. 3023; A . , 1303; G. Illari, Ann. Chim. Appl., 1929, 19,443; A., 101 ; L. Palfray and (Mlle.) D. Sontag, Bull. SOC. chim., 1930, [iv],47, 118; A., 357; S.Sabetay and J. BlBger, ibid., p. 114; A., 318; g. V.Alekseevski and Y. S. Pikazin, J. Appl. Chem. Russia, 1930,3,273; A., 1460.See also p. 207.51 K. Wiilfert, Mikrochem., 1930, 8, 100; A., 441; J. F. Reith, Pharrn.Weekblad, 1929, 66, 829; A., 1929, 1410.62 H. Zahnd and H. T. Clarke, J. Amer. Chem. SOC., 1930, 52, 3276; A.,1303; E. Wertheim, ibid., pp. 1075, 1086; A., 799; H. Emerson, ibid., p.1291 ; A., 799.6s T. von Fellenberg, Mitt. Lebensm. Hyg., 1929, 20, 321; A., 1198; Bio-chem. Z . , 1930, 218, 283; A., 799.64 J. J. Rutgers, Compt. r e d . , 1930, 190, 746; A., 629.S. Tashiro and E. B. Tietz, J. Biol. Chem., 1930,87,307; A., 1198224 ELLIS AND FOX:provements and modifications have been made in the hydrogenationprocess of determining nitrogen,55 sulphur,5G and oxygen.57A critical account and bibliography of methods for the identific-ation and determination of methyl alcohol in presence of ethyl alcoholare given,58 as also are methods for the determination of smallquantities of saturated alcohols.59Some iodometric methods have been examined 6o and also someanalytical reactions of lead tetraethyl.61 Quantitative methods forthe following acids are described : tartaric,62 citric in the presenceof some other organic acids,G3 oxalic in stomach contents,64 andaliphatic mer~apto-acids.~~Nicotine may be precipitated and weighed in the form of its tetra-chloroiodide ; 66 antipyrine and pyramidone, but not the products ofboiling the latter with hydrogen peroxide, give sparingly solublepicrates.67 Quantitative methods, mostly colorimetric, are de-scribed for chlorophyll,68 cholesterol,69 carotinoids, 70 cerebrosides, 71choline,72 arginine,73 cystime,ya proteins,75 trypaflavin and rivanol, 7656 H.ter Meulen, Rec. trav. chim., 1930, 49, 396; A., 629.56 H. ter Meulen, H. F. Opwyrda, and H. J. Ravenswaay, Chem. Weekblad,1930, 27, 19 ; A., 357.6 7 H. ter Meulen, H. J. Ravenswaay, and J. R. G. de Veer, ibid., p. 18 ; A.,367.A. Ionesco-Matiu and C. Popesco, J . Pharm. Chim., 1930, [viKJ, 12, 63;A., 1303.69 W. Ponndorf, 2. anal. Chem., 1930, 80, 401; A . , 1159; P. M. Marrianand G. F. Marrian, Biochem. J., 1930, 24, 746; A . , 1159.6o W. H. Hatcher and W. H. Mueller, Trans. Roy. SOC. Canada, 1920, [iii],23,111, 35; A., 324; R.Signer, Helv. Chim. Acta, 1930,13, 43; A . , 323.61 G. Edgar and G. Calingaert, Ind. Eng. Chem. (Anal), 1929, 1, 221; A.,1929, 1474; K. Dosios and J. Pierri, Z . anal. Chem., 1930, 81, 214; A., 1277.62 H. Besson, J . Pharm. Chim., 1929, [viii], 10,536 ; A., 193 ; P. H. Richert,I d . Eng. Chem. (Anal.), 1930,2,273 ; A., 1163; K. Tiiufel and B. W. Rlarloth,2. anal. Chem., 1930,80, 161; A . , 743.A. I. Kogan, ibid., p. 112; A., 743.64 G. D. Elsdon and J. R. Stubbs, Analyst, 1930,55,321; A., 941.6 6 E. Larsson, 2. anal. Chem., 1929, 79, 170; A., 234.66 F. D. Chattaway and G. D. Parkes, J., 1929, 2817; A., 227.67 S . Erikson, Svensk Farm. Tidskr., 1930,34, 1 ; A., 1199.68 H. B. Sprague and L. B. Troxler, Science, 1930,71,666; A., 1199.70 H.von Euler, H. Hellstrom, and M. Rydbom, Mikrochem., 1929, Pregl71 P. Kimmelstiel, ibid., p. 165; A., 1929, 1474.72 W. Roman, Biochem. Z., 1930,219,218; A., 762.73 C. J. Weber, J . Biol. Chem., 1930,86, 217; A., 755.74 C . Rimington, Biochem. J., 1930, 24, 1114; A., 1420.75 R. Whternitz and Z. Stary, Mikrochem., 1930, 8, 252; A., 1199.76 M. J. Schulte, Pharm. Weekblad, 1930, 67, 809; A., 1304.R. Okey, J . Biol. Chem., 1930, 88, 367; A., 1303.Fest., 69 ; A., 1929, 1474ANALYTICAL CHEMISTRY. 225rhamnose,?' and starch.78 A method for the determination ofmonosaccharrides in presence of lactose involves the use of bufferedBarfoed solution ; 79 under specified conditions, aldose sugars use orremove two equivalents of iodine and three of alkali.80 The effect ofdextrose and sucrose on the determination of lswulose by Nijn'smethod is recorded.81 The process of Baudouin and Lewin for themicro-determination of dextrose has been improved by the additionof barium sulphate, which greatly facilitates dissolution of the mer-cury.82 The micro-determination of various xanthyl derivatives bycomplete oxidation with sulphuric and iodic acids has been workedout .83 Primary arsinic acids may be determined volumetricallywith thymolphthalein as indicator in the presence of sodiumchloride ; 84 volumetric processes are described for diphenylchloro-arsine and diphenylarsine oxide, alone or in admixture.85Guaiacol carbonate is quantitatively brominated in methyl-alcoholic solution ; 86 quinol and pyrocatechol are quantitativelyoxidised by ferric chloride to yuinones, which may be determinediodometrically, the method being applicable in the presence ofphenol, resorcinol, and certain other phenols.87Physical Methods.Slight turbidity in the solution affects the measurements of opticalactivity ; 88 a special polarimeter is described whereby minute con-centrations of laevulose and of dextrose can be accurately deter-mined.89 An optical method for measuring the mercury content ofair has been devised, based on the extent of absorption of themercury line 2537 Sublimation points of numerous substances77 R.A. McCance, Biochem. J., 1929,23, 1172; A., 325.78 L. Paloheimo, Biochem. Z., 1930,222, 150; A., 1167.0.Svanberg, 2. physiol. Chem., 1930,189, 219; A., 894.C. S. Sbter and S. F. Acree, Ind. Eng. Chem. (Anal.), 1930, 2, 274; A.,F. W. Zerban and L. Sattler, ibid., p. 307 ; A., 1165.P. Fleury and J. Marque, J . Pharm. Chim., 1929, [viii], 10,292 ; A., 1929,1106.1426.83 L. Cuny and J. Robert, ibid., 1930, [viii], 11, 241; A., 629.84 H. King and G. V. Rutterford, J., 1930, 2138; A., 1461.86 E; D. G. Frahm and H. L. Boogert, Rec. trav. chim., 1930, 49, 623; A.,86 L. H. Chernoff, J . Amer. Chem. SOC., 1929,51,3072; A., 1929, 1441.87 F. Bock and G. Lock, Monabh., 1929,53 and 54,888 ; A., 1929, 1474.88 H. K. Miller and J. C. Andrews, I d . Eng. Chem. (And.), 1930, 2, 283;941.A., 1142.J. W . Meijer, Rev. Sci. Iwtr., 1930, 2, 69; A., 681.REP.-VOL.XXVTI. H90 K. MiiUer and P. Pringsheim, Natwwiss., 1930,18, 364; A., 727226 ELLIS AND FOX:are recorded at atmospheric pressure and in a vacuum, together withtypical photomicrograph^.^^ Immersion of transparent solids inliquids of approximately the same refractive index causes them toappear various shades of blue when observed through the micro-sc0pe.~2 The technique and application of rotation dispersion to thesolution of chemical problems are reviewed.93 The magnitude of thephoto-electric current generated in the filament of a neon lamp canbe used to indicate the end-point of titrations involving colourchanges or precipitation^.^^Colorimetric methods of analysis are discussed under the headingsof true colorimetry, nephelometry, and titrimetric methods ; 95 someother papers dealing with nephelometry are recorded.96Much work has been carried out on spectrographic methods ofanalysis ; 97 Lowe’s interferometer is applied to the determination ofalkalis in minerals.98Electrolytic.-Thallium is deposited on the anode from a solutioncontaining hydrofluoric acid as an adherent film approximating toT1203,HF.99 The use of Wood’s metal as cathode has been extendedto include the determination of tin, silver, iron, nickel, cobalt, andthallium.1 Two schemes are recorded to avoid the use of platinumelectrodes in the electro-analysis of copper.2 Other work in thissection deals with nickel, cobalt and zinc,3 sodium, potassium, and91 H.Hoffmann, jun., and W. C. Johnson, J . Assoc.08. Agric. Chem., 1930,13, 367 ; A., 1263.92 H. Wagner, 2. angew. Chem., 1930, 43, 686; A., 1263.94 T. Somiya and S. Shiraishi, J . SOC. Chem. Ind. Japan, 1930, 33, 3 0 0 ~ ;e5 N. Schoorl, Chem. Weelcblad, 1930, 27, 52 ; A , , 309.96 J . Erdos, 2. anal. Chem., 1930,80, 122; A., 724; L. T. Fairhall and J. R.Richardson, J . Amer. Chem. SOC., 1930, 52, 938; A., 563; J. A. de Loureiro,Hiochem. Z . , 1930, 224, 337; A., 1391; F. Rimattei, J . Pharm. Chim., 1929,[viii], 10, 349; A., 1929, 1410.97 H. Lundeghrdh, Arkiv Kemi, Min., Geol., 1929, 10, [A], No. 1 ; A., 311;Svensk Kem. Tidskr., 1930, 42,51; A., 560; B. A. Lomakin, 2. anorg. Chem.,1930, 187, 75; A., 445; B. de la Roche, Bull. SOC. chim., 1930, [iv], 47, 660;A . , 1145; P. Urbain, Compt.rend., 1930,190,940; A., 728; J. Papish, L. E.Hoag, and W. E. Snee, I d . Eng. Chem. (Anal.), 1930, 2, 263; A., 1143;J. Papish and D. A. Holt, 2. anorg. Chem., 1930,192,90 ; A., 1393 ; H. Lucas,Physikal. Z., 1930, 31, 803; A., 1264; S. Pifiia de Rubies and J. Dorronsoro,Anal. Fis. Quim., 1929, 27, 778; A., 183; G. Piccardi, Atti R. Accad. Lincei,1929, [vi], 10, 258; A., 313; A. Corsi, Nuovo Cim., 1929,6,275; A , , 441.O 8 G. Burger, Monatsh., 1929, 53 and 54, 985; A., 1929, 1411.99 A. Jilek and J. Lukas, Chem. Listv, 1930, 24, 223, 245; A., 1147.G. Kortiim, ibid., p. 341 ; A., 728.A., 1263.H. Paweck and W. Stricks, 2. anal. Chem., 1929, 79, 115; A., 184.P. S . Tutundiid, 2. anorg. Chem., 1930,190,59; A., 882; J. Guzm&n andA. Rancafio, Anal.Pis. Quim. (tech.), 1939, 27, 269; A., 183.B. Tougarinov, Bull. SOC. c h h . Be&., 1930, 39, 331; A , , 1394ANALYTICAL CHEMISTRY. 227~alcium,~ lead and bi~muth,~ and various metals by ‘‘ internalelectrolysis.” 6Potentimetric.-Attention is drawn to some important points inthe determination of hydrogen-ion concentration. The reactionshave been followed between sodium hydroxide and copper sulphate,*ferrous or ferric ~hloride,~ anti aluminium and magnesium chlorides,present together ; lo and in the last instance also that with sodiumfluoride. Some applications of the titration of mercurous nitratewith alkali oxalates are described ; 11 several papers deal with acid-alkali titrations.12 Methods have been described for the potentio-metric determination of selenium, tellurium, and gold,13 of gold andplatinum,14 nickel,15 zinc,l6 arsenic, antimony, tin, and thallium,f7and copper.18In a series of argentometrio studies, the determination of iodidesand bromides in chlorides,l9 and of halides in presence of sulphites,20has been described. Conditions are prescribed for the titration ofA. Belhk and Z. von Alfoldy, Biochem. Z., 1929,214, 110; A., 52.E. M. Collin, Analyst, 1929, 54, 654; A., 53.H. J. S. Sand, ibid., 1930,55,309; A., 880.I. M. Kolthoff and T. Kameda, J . Amer. Chem. SOC., 1929, 51, 2888;A., 1929, 1410 ; L. Fletcher and J. B. Westwood, J . SOC. Chem. I d . , 1930,49,R. Tomii, E. Okabe, and S. Takeda, Bull. Dept. Appl. Chem. Waseda201T; A , , 1009.Univ. Japan, 1929, 9, 6 ; A., 564. ’ L. W. Elder, jun., Amer. Electrochem. SOC., 1930, May; A., 565.lo W. D. Treadwell with E. Bernasconi, Helv. Chim. Acta, 1930, 13, 500;A , , 1149.l1 C. Mayr and G. Burger, Monatsh., 1929, 53 and 54,493; A., 1929, 1413;ibid., 1930, 56, 113; A., 1264.l2 A. Rius y Mir6, Anal. Pis. Quim., 1929, 27, 605; A., 50; I. I. Shukovand V. M. Gortikov, Z . Elektrochem., 1929,35,863; J . Rws. Phys. Chem. SOC.,1929,61,2056 ; A., 50 ; M. L. Holt and L. Kahlenberg, Amer. Electrochem. SOC.,1930, May; A., 724; F. L. Hahn and R. Klockmann, 2. physikal. Chem.,1930,146, 373; A., 560; B. L. Clarke and L. A. Wooten, J . Physical Chem.,1929, 33, 1468; A., 1929, 1410; F. L. Hahn, 2. angew. Chem., 1930, 43, 712;A., 1263; S. Linda and J. Ettinger, Rocz. Chem., 1929, 9, 504; A., 1929,1411.K. Someya, Sci. Rep Tdhoku Imp. Univ., 1930, 19, 123; A., 725; Z .anorg. Chem., 1930, 187, 337.l4 E. Miiller and W. Stein, Z . Elektrochem., 1930,36,220, 376 ; A., 728, 1013 ;E. Zintl, ibk?., p. 551; A., 1265.l5 T. Heczko, 2. anal. Chem., 1929,78, 325; A., 1929, 1415.l6 S. Sait6, Bull. Inst. Phys. Chsm. Res. Tokyo, 1929, 8, 921; A., 53; N.l7 C. del Fresno and L. Valdbs, AnaE. Pis. Quim., 1929, 27, 595; A., 51.l8 (Miss) M. E. Pring and J. F. Spencer, Analyst, 1930, 55, 375; A., 1011,19 0. Tod6ek and A. Jhnskp, Coll. Czech. Chem. Comm., 1929, 1, 585; A.,51; ibid., 1930, 2, 1, A., 310.go Idem, ibid., 582 ; A., 60.Joassart and E. Leclerc, Bull. SOC. chim. Belg., 1930, 39, 231 ; A., 1011228 RLLTS AND FOX ANALYTICAL CHEMISTRY.phosphates, arsenates, and arsenites with silver nitrate,2f and ofalkali sulphides with sodium nitroprusside.22Conductmetric .-T he t itration between sulphate and bariumacetate and between ferrocyanide and zinc chloride may be followedin boiling, neutral solution by replacing the usual telephone by czsystem whereby the current is measured by a gal~anometer.~~ Themost important applications of conductometric titrations have beensummarised .24B. A. ELLIS.J. J. FOX.21 M. H. Bedford, (Miss) F. R. Lamb, and W. E. Spicer, J. Amer. Chern. 80%22 G. Scagliarini and P. Pratesi, Atti R. Accad. Lincei, 1930, [vi], 11, 193 ;28 G. Jander, 2. angew. Chrn., 1929,42,1037; A., 51 ; G. Jander, A. Pfundt,24 I. M. Kolthoff, Ind. Eng. Chm. (Anal.), 1930, 2, 225; A., 1142.1930,52, 683; A., 442.A., 726.and H. Schorstein, ibid., 1930,43,607; A., 1142

ISSN:0365-6217    

DOI:10.1039/AR9302700203

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

BIOCHEMISTRY.Metabolism of Moulds.THE marked increase in the amount of research devoted to a studyof the metabolic product of moulds since the war can be traced tothe curious fact that in the case of nearly all the chemical compoundsproduced by fermentation methods, there is no alternative, satis-factory, purely chemical method of preparation. The industrialimportance of such processes, therefore, cannot be over-emphasised,and it is noteworthy that the researches of Raistrick and his co-workers on the biochemistry of micro-organisms which are men-tioned later in this Report were carried out between the years 1922and 1928 in the laboratories of Nobel’s Explosives Company atArdeer, and are now published as 18 consecutive papers in a specialnumber of the Philosophical Transactions.lCarbon Balance 8heets.-Of the two classes of micro-organisms(bacteria and true fungi) which can be readily cultivated in artificialmedia, much attention has been paid in the past to the chemicalactivities of the bacteria,la and of the family of true fungi knownas the yeasts, but very little to the other classes of true fungi knownas the “ moulds.” In recent years an increasing amount of work onthe metabolism of the moulds, especially the production of acids,has been published,2 but in 1922 it seemed to Raistrick and his co-workers, who wished to make a general survey of the metabolicproducts of moulds, that it would be impossible to investigate indetail, in any reasonable period of time, the chemical compoundsformed by even a small proportion of the different known species offungi.For this reason, then, instead of attempting the isolationand identification of the compounds formed by any mould taken a trandom, it was decided to investigate quantitatively the types ofcompounds formed by each of a large number of fungi, so as toobtain a logical basis for the choice of any particular fungus for laterinvestigation. To this end a so-called “ carbon balance sheet ” wasprepared for every species that it was proposed to study : this wasfound to be of great utility, for it gave a clean-cut classification ofthe various types of product formed and of their quantitativerelationships. In order to reduce the scope of the work, and to1 PAX Tram., 1930, 220, 1.15 Compare Marjory Stephenson, “ Bacterial Metabolism,” London, 1930.a Compare Ann.Repvrte, 1927,24, 222230 CHIBNALL AND PRYDE :ensure the possibility of repetition, all experiments were carried outwith glucose as the sole source of carbon in a Czapek-Dox syntheticmedium. In this respect the work differs somewhat from that ofof her investigators.The balance sheets show the location, after the metabolism, of allthe carbon originally present as glucose in the culture solution. Forthe practical details of the method the reader must refer to theoriginal paper : it is possible here to mention but briefly the tentgpes of compound in which the carbon is estimated. These arc(1) evolved carbon dioxide, (2) gases other than carbon dioxide,(3) volatile products such as ethyl alcohol, etc., (4) the mycelium,(5) total carbon in the metabolism solution, which was furthersubdivided into ( a ) residual glucose, ( b ) dissolved carbon dioxide,(c) volatile acids, (d) non-volatile acids, ( e ) carbon compoundsprecipitable by iron, e.g., proteins, (f) carbon unaccounted for.By means of the carbon balance sheets it has been possible toeliminate from further investigation all those fungi-constitutingby far the greater number-which, under the conditions of theexperiment, produce practically nothing but carbon dioxide fromglucose.In all, some 96 species of Aspergill~s,~ 75 species ofPenicillium, 8 species of Citrmyces,5 23 species of Fusarium,6 and36 miscellaneous species of fungi have been examined, and fromthem a choice of species suitable for further intensive investigationhas been made. The general results obtained can be summarisedas follows.81.The carbon balance sheets may be used as a biochemicalmethod for the classification of different species in certain familiesof fungi. This is particularly so in the case of the Aspergilli, inwhich a classification based on biochemical characteristics followsclosely that founded on morphological observation. With speciesof Fusarium, however, there is little hope of a biochemical classi-fication, for each of the species tried gave rise principally to ethylalcohol and showed close alliance with the yeasts.2. Some light is thrown on the biochemistry of the initial stagesof the breakdown of the glucose molecule by fungi. It appears that3 J.H. Birkinshaw and H. Raistrick, Phil. Trans., 1930, 220, Pt. 2.J. H. Birkinshaw, J. H. V. Charles, H. Raistrick, and J. A. R. Stoyle,5 J. H. Birkinshaw, J. H. V. Charles, A. C. Hetherington, H. Raistrick, andJ. H. Birkinshaw, J. H. V. Charles, H. Raistrick, and J. A. R. Stoyle,J. H. Birkinshaw, J. H. V. Charles, A. C. Hetherington, and H. Raistrick,H. Raistrick and W. Rintoul, ibid., Pt. 1.ibid., Pt. 3.C. Thorn, ibid., P t . 4.ibid., Pt. 6.ibid., Pt. 6BIOCHEMISTRY. 23 1the first step is a Cannizzaro reaction involving the formation fromtwo molecules of glucose of one molecule of mannitol and onemolecule of gluconic acid. Depending then on whether the mouldin question prefers for growth an acid or a neutral medium, eithermannitol or gluconic acid (of course, in some cases both) is destroyed.Thus a certain species of white Aspergillus which gives rise to yieldsof mannitol approximating to, but never exceeding, 50% of theglucose metabolised produces very little if any gluconic acid, refusesto grow in an acid medium, and even when cultivated on a mediumwith an initial pH of 4.6 changes this during the course of its growthto 66-7.On the other hand, species such as Aspergillus Wentiiand Penicillium chrysogenum, which produce large quantities ofgluconic acid, give little or no mannitol, on which material they growquite well, but in all cases bring the pH of the medium down to about1-2. Other species again produce moderate amounts of both thesesubstances.The production of these two materiaIs from glucose raises aninteresting stereochemical point.Glucose on reduction should givesorbitol, and on oxidation, gluconic acid; mannose on similartreatment, mannitol and mannonic acid. Yet in spite of frequentsearch for sorbitol and mannonic acid as metabolic products of fungino trace of them has been found.3. Perhaps the most striking fact is the extraordinary specificityof some of the mould products. It would appear that certaingeneral biochemical reactions such as the production from glucoseof mannitol or gluconic acid, of ethyl alcohol, of citric and oxalicacids may be regarded as common to many species belonging tomany different families of fungi, but at the same time there arecertain highly specific substances which are produced, in some casesby a single species, and in others by a very small sub-group contain-ing a very few species.Citrinin, for instance, is specific for Penicill-ium citrinum Thom, and may be used as a test for this species by thepurely chemical test of adding ferric chloride to the metabolismsolution, whereupon a characteristic iodine brown colour is produced.All these specific products, some of which are referred to briefly later,are more complex than glucose and are good illustrations of theamazing synthetic powers of these organisms.Metabolic Products of Moulds.Oxalic, Citric, and Gluconic Acids.--It is now generally recognisedthat these three acids are produced by most moulds, and that thesecond two are not as specific as was a t first suspected.have found that Succinic Acid.-Raistrick and his co-workers' J.H. Birkinshaw and H. Raistrick, Phil. Trans., 1930, 220, Pt. 17232 CHIBNALL AND PRYDE :this acid is formed in small amounts from sugar by several speciesof Aspergillus and Fumccgo vagans. It was isolated as the ester,and identified as the free acid and anhydride. Its production byRhixopus species growing on a medium containing acetates has beenshown by T. Takahashi and K. Asai 10 and W. S. Butkevitsch andM. W. Federov.ll Using the calcium salt of n-butyric acid as asource of carbon for the growth of A . niger, H. B. Stent, V. Subra-maniam, and T. K. Walker l2 have isolated, with other products,succinic acid, which was identified by its m.p. and conversion intodi-p-nitrobenzyl succinate. They consider that the butyric acidfirst undergoes P-oxidation with the production of acetone. Furtheroxidation yields acetic acid, which then undergoes dehydrogenationaccording to the Thunberg-Wieland hypothesis :3CH,*CO*CH, -+ CH,*CO*CO,H + 2CH,*CO,H -+CH,*CH( OH)*CO,H + CO,H*CH,CH,*CO,HFumaric Acid.-This was first observed by F. Ehrlich l3 in 1911to be a product of Mucor stolonifer. Recently W. S. Butkevitschand M. W. Federov l4 claim to have obtained good yields of this acidwhen the organism is grown on solutions of glycerol, acetic acid andsugar. C. Wehmer l5 in 1918 obtained good yields from sugar by aspecies of Aspergillus which he named A.fumaricus. In a culturereported to be this species Raistrick and his co-workers failed toobtain fumaric acid, and it is worthy of note that in a recent paperWehmer 16 states that his culture, which originally gave largeamounts of this acid, now produces only traces of this substance, andthat gluconic acid is now formed instead. A similar experience isrelated by R. Schreyer.17 His culture of A. fumaricus has in thecourse of time lost its power of producing fumaric acid, and nowgives rise to citric and gluconic acids. It would appear that we havein this an interesting case of evolutionary change of metabolism.The claim of A. Gottschalk l8 that Rhixopus nigrz'cuns whengrown on a solution of pyruvic acid gave rise to fumaric acid wasdisputed by F.Ehrlich and I. Bender,19 who state that no growthtakes place on such a medium. This has now been admitted by10 Bull. Agric. Chem. SOC. Japan, 1928, 113.11 Biochem. Z . , 1930,219, 87; A., 643.l2 J . , 1929, 1987, 2485; A., 1929, 1271; 1930,66.13 Ber., 1911, 44, 3737.l4 Biochem. Z . , 1929,207,302; 1930,219, 87; A., 1929, 724; 1930, 643.15 Ber., 1918, 51, 1663.Is Biochem. Z., 1928,197,418; A., 1928, 1164.Ibid., 1928, 202, 131; A., 1929, 217.2. physiol. Chem., 1926,152, 136; A., 1926, 546.Is Ibid., 1927,170,118; 172,314; A . , 1928,95: 1928. 804BIOCHEMISTRY. 233Gottschalk and confirmed by W. S. Butkevitsch and M. W. FederovY2Owho state that in the presence of calcium carbonate, which was aconstituent of the nutrient solution, pyruvic acid undergoes a changeto a monobasic acid of empirical formula C,H604, which bears norelationship to the activity of the mould.Malic Acid.-Casual references to the production of this acid bymoulds occur in the earlier literarure. C.Wehmer l6 has now showndefinitely that it is produced in small amounts from sugar byAspergillus fumricus. Raistrick and his co-workers 21 also haveisolated the acid as its ester from the products of a white species ofAspergillus, and also from A. Wentii growing on glucose.The biochemical infer-relationship between succinic, fumaric andmalic acids was referred to in a previous Report.21a It would appearthat similar inter-conversion can be brought about mycologically.T. Takahashi and K. Sakaguchi22 have shown that a Rhixopusspecies can convert fumaric into 2-malic acid, and can also bringabout the reverse change.3'. Challenger and L. Klein 23 have shownthat a strain of A . niger affords excellent yields exclusively ofZ-malic acid when grown upon a fumarate medium. They thereforeconclude that the enzyme fumarase is secreted by the organism.Using the same strain of A . niger and a succinate medium, €3. B.Stent, V. Subramaniam, and T. K. Walker 24 obtained a mixture ofdl-malic and Z-malic acids. As oxidation of auccinic acid by hydrogenperoxide in the presence of ferrous sulphate yields as a first stagemalic acid, they consider that thisdl-malic acid 25 owes its formationto the direct hydroxylation of the succinic acid, a process which theythink could be effected by an aerobic oxydase system.The Z-malicacid, however, they consider has arisen through a preliminarydehydrogenation of the succinic acid to fumaric acid, which is thenacted on by the fumarase, and not to any preferential utilisation ofthe d-isomeride by the mould growing on the dl-malic acid. It isinteresting to note that Ruhland and Wetzel (p. 246) find anaccumulation of both dl-malic and Z-malic acid in developing rhubarbstalks.MannitoL-Although the presence of mannitol in the myceliumof fungi has long been recognised, it appears to have been con-sidered simply as a reserve food comparable with the glycogen ofyeast and not as a definite fermentation product. Raistrick and2o Biochem. Z., 1929,206,440; A., 1929, 607.*1 J.H. Birkinshaw and H. Raistrick, Phil. TTUW., 1930, 230, Pt. 17.21a Ann. Reprte, 1928,25, 226.22 Bull. Agric. Chem. SOC. Japan, 1927,3, 59.23 J., 1929, 1644; A., 1929, 1166.24 Ibid., p. 1987; A., 1929, 1371. 26 Ibid., p. 2486; A., 1930, 66.H 234 CHIBNALL AND PRYDE :his co-workers26 have now shown that it is produced by manymoulds, and by certain species of white Aspergillus in particular, inyields as high as 50% of the sugar metabolised. The alcohol 27 wasestimated in presence of glucose by a method depending on theincreased rotation observed when borax was added to the solution,allowance being made for the fact, hitherto unrecorded, that glucosein 0.9% concentration in 6% borax solution is optically inactive andat concentrations up to 0.9% is lzvorotatory.It was found thatculture solutions in which the amount of aeration was unrestrictedgave only small yields, and the high values quoted above were onlyobtained when the amount of aeration was strictly limited.Po1ysaccharides.-A few polysaccharides from the lower fungihave been previously recorded, and given appropriate names, butattempts to fmd out their constitution have been limited to showingthe reaction, if any, to iodine and the sugar given on hydrolysis.Raistrick and his co-workers 28 have encountered several suchsubstances in the course of their work. From a species of Asper-gillus they have isolated what appears to be glycogen.27From Fumago vagansZ1 they have isolated a new substance,which separates from water as a white amorphous precipitate, andfrom the mycelium of Penicillium digitatum, S a ~ c a r d o , ~ ~ a similarsubstance which is insoluble in cold, but moderately soluble in hotwater.These two substances give no colour with iodine, have anempirical formula CeHlo05, and in aqueous solution are neutraland strongly dextrorotatory . They give rise quantitatively toglucose on hydrolysis with dilute acids, and are unaffected byinvertase or diastase.The most interesting product, however, is that formed fromYenicillium luteurn, Zukal, a mucilage which the authors havenamed “ luteic ’’ acid.30 The crude product as first isolated is themagnesium salt of a complex organic acid, and from this the pureacid, a white amorphous mass resembling starch, was eventuallyprepared.It gives a gelatinous solution in water and does notreact with alkaline iodine, reduce Benedict’s solution or form anosazone, thereby showing that it contains no free aldehyde groups.It is lzvorotatory and on hydrolysis with dilute acids it gives riseexclusively to glucose and malonic acid; a t the same time theacidity of the material is doubled. From these and other con-siderations, it is concluded that the substance is a complex built upz6 J. H. Birkinshaw, A. C. Hetherington, and H. Raistrick, Phil. Trans.,1930, 220, Pt. 9.27 H. Raistrick and W. Young, ibid., Pt. 10.28 Idem, &id.29 J. H . Birkinshaw, J. H. V. Charles, and H. Raistrick, ibid., Pt. 18.30 H. Rnistrick and M. Rintoul, ibid., P t . 13BIOCHEMISTRY.235of units, each of which is a condensation product of two moleculesof glucose with one molecule of malonic acid with the loss of twomolecules of water, in which one carboxyl is free and the otherin combination, and two aldehyde groups are linked in such away as to destroy their aldehydic properties. Polysaccharides ofthis type, in which part of the simple hexose units is replaced bya simple organic acid, are very rare, and the only other well-authen-ticated example is, curiously enough, also of microbiological origin.This is the “ soluble specific substance ” from young cultures ofpneumococcus which has been recently isolated by Heidelberger andGoebel3l and shown to give rise to glucose and glucuronic acid onhydrolysis. The natural gums, e.g., gum arabic, are of course ofsimilar type, but in these cases the nature of the complex constituentacid has not been worked out.Kojic Acid.-This acid was shown by T.Yabuta in 1924 32 to be5-hydroxy-2-hydroxymethyl-y-pyrone, and is characterised by theintense wine-red colour it gives with ferric chloride in dilutions ofeven 1 : 200,000. In ignorance of earlier work Raistrick and hisco-workers 33 in 1923 found that the balance sheet of A . parasiticusshowed that more than 19% of the sugar consumed was unaccountedfor, and from this investigation rediscovered this acid, noted inYabuta’s paper. A . Jlarvus, e$fwus, and tamarii also give this acid,which appears to be of diagnostic value, in that it justifies one inplacing in the flavus-oryzce-tamarii group of Aspergilli any speciesof this genus which, if cultured under certain specified conditions,gives rise to the typical kojic acid reaction, without, however,necessarily excluding from this group any Aspergiltus which gives anegative reaction.F.Traetta-Mosca34 showed that the acid is produced fromglycerol, sucrose, glucose and laevulose by a mould which he calledA . ghww, but which Raistrick and his co-workers believe to be amember of the Jlavus-oryxce group. F. Challenger, L. Klein, andT. K. Walker 35 showed that it was produced by a mould they callA . oryzce diastccse from arabinose and xylose, and the list of pre-cursors given by Raistrick a.nd his co-workers includes all thesesubstances together with lactose, galactose and mannitol.Thelatter workers point out that the idea originally held, that kojic acid(C,H,O,) arises from glucose (C,H&,) by a simple oxidation anddehydration, offers no explanation of the formation of the acid from31 Ann. Reports, 1927, 24, 251.33 J. H. Birkinshaw, J. H. V. Charles, C. H. Lilly, and H. Raistrick, Phil.34 Buzzetta, 1921, 51, ii, 269; A., 1922, i, 91.35 J . , 1929,1498; A., 1929, 1042.32 J., 1924,125,575.Trans., 1930, 220, Pt. 7 ; J. H. Birlrinshaw and H. Raistrick, ibid., Pt. 8236 CHIBNALL AND PRYDEcompounds containing less than six carbon atoms in the molecule,e.g., xylose, arabinose, and glycerol. They think that either ofthe following explanations seems to offer a solution of the difficulty,but consider that there is at present no conclusive experimentalevidence as to whether either is correct :-(1) I n common with some other types of fermentation, as shownfor glycerol by Neuberg and his co-workers, acetaldehyde may beproduced by the fungus from the carbon source supplied, whetherthis be a poly-, di-, or mono-saccharide, a pentose or a polyhydricalcohol.The acetaldehyde may then be condensed by a series ofreactions to kojic acid. This explanation is apparently supportedby the fact that it has been shown that all those fungi which producekojic acid also produce at the same time ethyl alcohol, and hence,in passing, acetaldehyde.(2) The source of carbon supplied, whatever its nature, may befirst metabolised by the fungus into a reserve carbohydrate, which islater hydrolysed by the micro-organism, as occasion arises, into amono-saccharide which in its turn gives rise to kojic acid.Theclose similarity between the amylene-oxide form of a 6-carbon sugarand kojic acid renders this a probable explanation, and it is furtherQH,*OH QH,*OHsupported by the fact that various fungi are known to store reservecarbohydrates, and to utilise them later as occasion demands, e.g.,glycogen in yeast, trehalose in A . niger.The view that the immediate precursor of the kojic acid is a3-carbon compound is favoured by F. Challenger, L. Klein, andT. K. Walker, who cite as a parallel the production of citric acidErom pentoses, and by A. Corbellini and B. Greg~rini,~~ who con-sider that the pyrone nucleus is formed by synthesis from 3-carbonoxidation products of glycerol by a reaction analogous to thatoccurring with aldehydes under the action of carboligase.New Phenolic 8ubstctnces.-Using glucose as source of carbon andthe carbon balance sheet as a guide to indicate the formation of" unaccounted carbon," Raistrick and his co-workers have isolatedthree new highly-coloured phenolic substances.From certain species of Citrolnyces 37 they have obtained yields36 Gazzetta, 1930, 60, 244 ; A., 959.37 A.C. Hetherington and H. Raistrick, Phil. Tram., 1930, 220, Pt. 11BIOCHEMISTRY. 237as high as 25% of the sugar fermented of a new yellow benzopyronederivative having the formula C,,Hlo0,,2H,0, which they havenamed citromycetin. It is a dihydroxy-carboxylic acid containinga benzopyrone nucleus, and from a study of its decompositionproducts it is considered to be (I).HO,C CO Et(1.1 (11.)0From 1'.citrinum, T h ~ m , ~ * and from no other species they haveisolated a new yellow crystalline colouring matter having theempirical formula C,,H1,O, which they have named citrinin. Froma study of its decomposition products F. P. Coyne, H. Raistrick, andR. Robinson39 tentatively assign to this compound the formula (11).They call attention to the fact that this carbon skeleton containstwo straight chains of 6 carbon atoms each, joined at their y-positionsby a thirteenth carbon atom.A third coloured substance, which separates as purplish-blackpermanganate-like crystals of the formula C8H805, was produced,together with much citric acid, by a strain of Penicillium spinulosum,It is a dihydroxymethoxytoluquinone, and is the firstrecorded instance of the production from glucose by fungi of aquinone derivative.It appears fairly certain that the substance isa p-quinone, but the relative positions of the methyl, methoxy, andtwo hydroxyl groups in the quinonoid nucleus can only be finallysettled by synthesis, as compounds of this type have not yet beendescribed in the literature.Perhaps the most interest'ing of the new products obtained fromglucose is the new polybasic fatty acid given by P. spiculisporumLehman.41 It is the lactone of y-hydroxy- pa-dicarboxypentadecoicacid (111), and its constitution has been proved in the following way.The substance is a dibasic acid and is stable towards acid.Onhydrolysis with caustic soda it yields a tribasic acid (IV), whichforms a monoacetyl derivative. The ease with which this tribasicacid reverts to the parent substance with loss of water on heatingsuggests that it is a y-hydroxy-tricarboxylic acid. On fusion withpotash the tribasic acid yields lauric acid (VI), succinic acid (VII)and carbon dioxide, and on oxidation with permanganate in acetone38 A. C. Hetherington and H. Raistrick, Phil. Trans., 1930, 220, Pt. 14.3Q Ibid., Pt. 15.4O J. H. Birkinshaw and H. ftaistrick, ibid., Pt. 12.4 1 P. W. Clutterbuck, H. Raistrick, and M. Rintoul, iW., Pt. 16238 CHIBNALL AND PRYDE :solution it gives a theoretical yield of a keto-acid shown by synthesisto be y-ketopentadecoic acid (V).CH3rp21tlQH3 QH3IQH219 LCH219CiH- 1+-YH*OH YoFH*CO,H 0 YH2FH*CO,H _j YH*CO,H -+ CH2CH2*C0--A/ CH,C 0 ,H(ITI.) (IV.) (V.1Y+ ?H2*Co2H + co, + H,O (iH3[ ~ H & CH,*CO,H CH,*CO,H(VI.) (VII.)These results show that the tribasic acid (IV) is y-hydroxy-@-di-carboxypentadecoic acid, and that the parent substance (111) isits y-lactone.It is interesting to note that y-ketopentadecoic aciditself was isolated from the metabolism solution, so that we havehere an undoubted instance of the production by a living organismof a fatty acid containing an odd number of carbon atoms. It isto be remembered, however, that this C,, acid and its dicarboxy-derivatives are not constituents of the mould " fat " but are excretedinto the fermentation solution, so their discovery does not necessarilyupset the view, now generally accepted, that natural fats containonly even-numbered carbon fatty acids.The degradation of the lower fatty acids themselves by fungi hasbeen recently investigated by T.K. Walker and his co-workers.A . niger was grown on an aqueous solution of the calcium salt of thefatty acid together with the requisite inorganic salts.42 Calciumpropionate was oxidised a t the cc-carbon atom, and lactic acid wasalways detected (thiophen test) before pyruvic acid (coloration givenwith benzenediazonium chloride in the presence of sodium acetate).Calcium n-butyrate, n-valerate and isovalerate gave the respectivep-hydroxy-acid and p-keto-acid and methyl ketone successively,showing that (3-oxidation had occurred in these cases.43The precise mechanism of p-oxidation of the normal fatty acidsin vivo is not yet known with certainty, previous experimental workindicating that the first product may be either a p-keto-acid, aP-hydroxy-acid or an ap-unsaturated acid.A11 of these are equallyeasily oxidised by the liver and are interconvertible.**42 T. K. Walker and P. D. Coppock, J., 1928,803; A., 1928,804.43 P. D. Coppock, V. Subrammiam, and T. K. Walker, ibid., p. 1422; A.,1928, 804. 44 H. D. Dakin, J . Biol. Chem., 1923,56,43BIOCHEMISTRY. 239When A . niger was grown on calcium n-butyrate Walker and hisco-workers cpuld not detect crotonic acid in the culture medium,nor would the mould grow on calcium crotonate as sole source ofcarbon.They consider that their evidence points to the initialformation of a p-hydroxy-acid and its subsequent oxidation to thecorresponding p-keto-acid. They therefore differ from W. N.St0koe,~5 who considers that the p-keto-acid is the initial product.The Chemistry of Plant Pathology.Pressing problems of economic importance have led during recentyears to a great increase in the amount of research devoted to plantpathology, but the mode of attack has been almost entirely bio-logical and research on strict chemical lines has been rarely initiatedand still more rarely successful. It is therefore noteworthy that thedifferences in susceptibility to a parasite of closely related plantshave been definitely connected with the presence or absence of achemical entity in the host.46 Red and yellow varieties of thecommon onion (Alliurn c e p ) are in general resistant to the diseasescaused by the fungus Colletotrichum circinans (Berk), whereas thewhite varieties are susceptible.Investigations revealed that anaqueous extract of the dry outer pigmented scales causes rupturingor abnormal germination of the spores and retards the growth ofthe mycelium of the fungus, whereas a similar extract from the dryouter white scales is not endowed with this property. Fractionationof the former extract led to the isolation of protocatechuic acid,which was found to be as toxic in dilutions of 1 part to 3000 parts ofwater as the original extract itself.The mode of preparation of theextract (digestion with 20 parts of water at 30" for 2 hours) and thechemical methods used in the fractionation exclude the possibilityof the acid having arisen by decomposition from quercetin, whichPerkin 47 showed was present in pigmented onion scales.The spike disease of Sandal (Santalum album, Linn.) has beeninvestigated by M. Sreenivasaya48 and his colleagues. They findthat the diseased leaves have a higher content of reducing sugars,total carbohydrates, and both total and soluble nitrogen than healthyones, and the sap has a definitely higher dinstatic activity. Further-46 Ann. Reports, 1929,26,210.4 6 K. P. Link, H. R. Angel, and J. C. Walker, J . Biol. Chem., 1929,84,719;A., 1929, 122; J .C. Walker, K. P. Link, and 13. R. Angel, Proc. Nat. Acud.Sci., 1929,15,845; A., 1929,262; H. R. Angel, J. C. Walker, and K . P. Link,Phytopath., 1930, 20, 431 ; A., 1224.4 7 A. G. Perkin and J. Hummel, J., 1896,69, 1295.48 J . I W n Imt. Sci., 1928,11A, 23, 97; 1929, 12A, 163; A., 1928, 804,1291; 1930, 385240 CHIBNALL AND PRYDE :more they state that mannitol can be isolated from diseased leaves,whereas it appears t o be absent in healthy ones.49A. A. Dunlap 5* has studied the virus diseases of plants, andsuggests that they may be divided into two classes, mosaic diseasesand yellows diseases, according to the effect of the disease upon thetotal nitrogen and total carbohydrate contents of the leaves of thehost plants. Mosaic disease caused an increase of nitrogen and itdecrease of carbohydrate, whereas yellows disease brought aboutthe reverse effect.His results are in general agreement with thoseof earlier workers; E. G. Campbell,51 for instance, found that leaf-roll disease of potato is accompanied by increase of carbohydrate,and R. H. True and L. A. Hawkins 52 found an increase of carbo-hydrate, and S. L. Jodidi 53 a decrease of total nitrogen, in blightdisease of spinach. Dunlap considers that the latter should beclassified as a yellows and not as a mosaic disease. Again, in fruits,A. S. Morne and F. G. Gregory 54 find that resistance to disease inapples is associated with high acidity, high potassium and lownitrogen, although the converse may also be true.Turning to the question of inorganic deficiency and plant diseases,it is of course well known that lack of certain essential elements suchas iron, potassium, and calcium brings about leaf chlorosis.Butduring recent years it has become increasingly evident, chieflythrough the work of J. B. Orr and his school a t Aberdeen,55 thatinorganic elements play a fundamental part in determining thenutritive value of pasture grasses. Deficiencies may occur which,though not so marked as to cause gross signs of disease, may yetlimit the rate of growth and the rate of productivity. Furthermorethese smaller deficiencies may adversely affect the “ constitution ”of the animal, rendering it more susceptible to some disease ofbacterial origin.R. Adam 56 and his colleagues have carried out an interestinginvestigation into the bactericidal action of a number of cyclic andstraight-chain fatty acids, which they have synthesised fromappropriate alkyl halides by the malonic ester condensation.The six different isomeric series of acids containing cyclohexylgroups,Nature, 1930,126,438 ; A ., 1483.50 Amer. J . Rot., 1930,17, 348.61 Phytopath., 1925,15, 427.52 J . Agric. Res.. 1918, 15, 381.63 J . Arne?. Chem. SOC., 1920, 42, 1061, 1885; A., 1920, i, 586.64 Proc. Roy. SOC., 1928, [B], 102, 444.6 5 Reviewed by J. B. Orr, “ Minerals in Pasture,” London, 1929.66 See W. M. Stanley, M. S. Jay, and R. Adams, J . Amer. Chem. SOC., 1929,1,1261 ; A., 1929, 676, in which reference is given to t% series of 15 papersBIOCHEMISTRY.241C,H,,*[CH,],*CO,H, C,H11*CHR*C02H, C6H,,*CH,*CHR*C02H,C,H 11-[ CH,],*CHR*CO,H, C6H, ,*[CH2],*CHR*CO2H, andC,H1,*[CH,],*CHR*CO,H, were found to possess high bactericidalaction in &TO to B. Zeprce. The effect increased with increase ofmolecular weight of the alkyl group, and was most potent when theacids had 16-18 carbon atoms. Further, those acids with thecarboxyl group a t the end of the chain were not nearly as effectiveas the isomerides with the carboxyl near the ring. As chaulmoogricand hydnocarpic acids both contain the A2-cyclopentenyl group, itseemed possible that a ring was necessary for bactericidal action;accordingly a series of acids of the general formula RCH(CO,H)R',in which R is a cyclopentyl, cyclopentenyl or cyclopropyl group,or one of these groups substituted in the w-position of theulkyl group, and R' is an alkyl group, was prepared and studied.l'he results indicated that there was no very marked differencebetween the acids containing the 3-, 5- or 6-membered rings,and that those with 16-18 carbon atoms were again the mosteffective. Finally a number of isomeric octadecoic and hexadecoicacids, which included a complete series of compounds with chainsof seventeen and fifteen carbon atoms, and a carboxyl group sub-stituted in every possible position, were prepared.The resultswith these acids showed conclusively that no ring was necessary forbactericidal action, and again it was found that the terminal carboxylgroup was the least effective.Adams and his co-workers concludefrom their studies that the effect of these acids towards B. Zeprceand other acid-fast bacteria can hardly be attributed to thechemical specificity of the individual acids, and is probably dueto a combination of physical properties common to many ofthem.J. M. Schaeffer and F. W. Tilley 57 have investigated manyisomeric alcohols in a similar way and find that those with thelongest straight chains or phenols having the longest straight chainin the para-position are the most efficacious germicides. Thecoefficients of cyclohexanol and of methylcyclohexanols are abouthalf as great as those of phenol and the corresponding cresols.The efficacy as contact insecticides of the n-fatty acids fromformic to stearic, and of their sodium and ammonium salts andmethyl esters, has been investigated by F.Tattersfield and C. T.Girni~~gham.~* The toxicity to Aphis rumicis L. of the acids fromacetic to undecoic rises with increase of molecular weight. Thesalts and esters were in general less toxic than the acids, but showeda similar rise with increase of molecular weight. The authors suggest5 7 J . Bact., 1927,14, 259; A . , 1928, 795.5 8 Ann. Applied Biol., 1927,14, 331242 CHIBNALL AND PRYDE:that the toxicity of these acids is bound up in some way withwater-solubility relationships.Nitrogenous Metabolism in the Plant.During the past year several interesting papers dealing with thenitrogen question in plants have been published. Many of theseemanate from Agricultural Stations, and much of the matter con-tained therein, although of great agricultural or horticulturalinterest, does not find a place in a Report devoted chiefly to progresson the chemical side. In addition, certain papers of fundamentalimportance published in a new journal, Phnta, during the pastfour years-to which the attention of the Reporter has only recentlybeen directed-fall to ’be discussed this year.Nitrogen Fixation by Bacteria.-Recent work by D.Burk on themetabolism of Axotobacter has led him to question the validity ofthe theory, now generally held, that the first stage in the fixation ofatmospheric nitrogen is the production of ammonia. He has usedthe manometric micro-methods for the study of cell-metabolismdevised by 0.W a r b ~ r g . ~ ~ He has shown-partly in collaborationwith 0. Meyerhof 60-that Axotobacter behaves uniquely towardsoxygen gas. Its rate of oxygen consumption and its efficiency ofnitrogen fixation are markedly conditioned by oxygen pressure ina manner characteristic of no other living organism. (1) The rateof respiration (measured directly by oxygen consumption) attainsa maximum at 0-15 atmosphere, diminishing rapidly at both higherand lower pressures, being only one-third as great at 0.005 and 1.0atmosphere. (2) The decrease in rate of respiration between 0.2and 1.0 atmosphere of oxygen is linear; this is true whether thecomplementary gas making the total pressure up to one atmosphere isnitrogen or hydrogen. (3) In the absence of free or fixed nitrogen,which would permit growth, the rates of respiration are independentof time at any given oxygen pressure, except in the high region of1 atmosphere, when they fall off with time.(4) In a young culturethe rate of respiration is enormously high, 2000 c. mm. of oxygenper mg. of dry matter per hour, or about three times its own dryweight of glucose. In contrast it may be noted that 0. Warburg’svalue for baker’s yeast is only 75 c . mm. and that the rate of respir-ation is independent of oxygen pressure between 0.03 and 0.97atmosphere. (5) The rate of nitrogen fixation attains a maximumat 0.4 atmosphere of oxygen, and is only one-third to one-sixth asgreat at 0.008 and 0.21 atmosphere. (6) The most important59 “ Uber den Stoffwechsel der Tumaren,” 1926, p.1-11.6o 2. physiiol. Chem., 1928, 139, 117; A,, 1929, 473; J . Physical C‘hem.,1930,34,1174,1195; A., 1068BIOCHEMISTRY. 243influence of oxygen pressure, however, is upon the efficiency ratio,nitrogen fixed/oxygen consumed, which increases some ten- totwenty-fold between 0.21 and 0.01 atmosphere.Burk admits that it is logical to suppose that these unusual meta-bolic properties are either the cause or the result of the similarlyexceptional ability of Azotobacter to fix nitrogen, and that anytheory of the chemical or catalytic mechanism of nitrogen fixationmust provide an explanation of them. This type of reasoning, forinstance, has been applied by certain workers recently to thebehaviour of certain strains of Axotobacter; 61 because ammonia wasfound in the culture fluid, it was considered to prove that ammoniawas concerned in nitrogen fixation.He does not think that suchreasoning is valid and recalls Winogradsky’s 62 original &dings thatthe ordinary metabolism and nitrogen fixation of these organismsare two distinct phenomena. The strains of Axotobacter used bythese workers produce ammonia extracellularly whether growingin either nitrogen gas or nitrate, and therefore there is no proof thatammonia is involved in their mechanism of fixation ; indeed, sincenitrates and nitrites are reduced vigorously to ammonia, it is equallylikely that the mechanism involves, rather than precludes, theformation of nitrogen-oxygen compounds such as nitrates.Burk’sstrains of Azotobacter produce neither ammonia nor nitrates extra-cellularly during fixation, nor ammonia when growing on nitrates,and he does not think that they can possess a different method offixation.Burk has so far established certain facts concerning the mechanismof fixation which are free from the above logical inconsistency.(1) At 0.2 atmosphere of oxygen, nitrogen is fixed at an appreciablerate only above 0-05 atmosphere, and tends to reach a maximumvalue a t about 5 to 10 atmospheres. (2) The efficiency of nitrogenfixation increases markedly with the rate of fixation. (3) All theunique oxygen pressure functions described above obtain in culturesgrowing on fixed nitrogen, and therefore offer no indication as to thenature of the chemical mechanism of fixation.63 (4) Humic acid,which greatly accelerates nitrogen fixation, is not directly concernedwith the mechanism of fixation but is a growth stimulant.( 5 ) Thefailure of legume bacteria t o fix nitrogen in the absence of the hostplant has been confirmed by gasometric studies under a variety ofpressures of nitrogen, hydrogen or oxygen between 0 and 1 atmos-6 1 S. Kostychew, A. Ryskaltschuk, and 0. Schwezowa, 2. physiol. Chem.,62 Compt. rend., 1893, 116, 1385; Arch. Sci. Biol. St. Petemburg, 1894-5,63 D. Burk and H. Lineweaver, J . Bact., 1930,19,389; A,, 1219.1926,134, 1.3, 297244 CHIBNALL AND PRYDE :phere. ( 6 ) The view of previous workers is supported and enlargedupon, that fixation is a function resorted to only in the absence ofsufficiently available fixed nitrogen.D.W. Cutler 64 records a new group of organisms distinct fromNitrosomoms and Nitrocrococcus, which produce nitrite from ammonia.Nitrate Reduction in Plant Roots.-The presence of small amountsof nitrate in green leaves has led to the view that the synthesis oforganic from inorganic nitrogen generally takes place in these organs.An interesting paper by G. T. Nightingale and L. G. Schermerhornshows that active reduction of nitrate to ammonia may take placcin the root system. When the asparagus plant is in a condition ofactive vegetative growth of tops, nitrates can be found only in thcfibrous roots. I n a plant lacking nitrates in its tissue and nutrientmedium, but containing reserve carbohydrate within its roots, thcexternal supply of nitrate leads to the production of nitrites andammonia in the fibrous roots only and not in the storage roots.Atthe same time asparagine and amino-acids appear in these organsin considerable quantities and the amount of reserve carbohydrateis reduced. The transformation of nitrates is most rapid from 20"to 30°, and is very slow at 10". The storage roots and activelygrowing tops of the asparagus plant apparently may assimilatenitrates) but rather seldom have an opportunity to do so becausenitrates are transformed to organic nitrogen in the fibrous rootsbefore reaching other organs of the plant. If, however, the tem-perature is 10" or lower, nitrates may be translocated to other partsof the plant.Later, with a rise of temperature, nitrates are rapidlyassimilated by and disappear from both the storage roots and theactively growing tops and are then found again only in the fibrousroots.A similar transformation of nitrate to organic nitrogen wasobserved by G. T. Nightingale and W. R. Robbins66 in the finefibrous roots of the paper-white narcissus (Polyanthus narcissus),and W. Thomas 67 concludes from his research on the nitrogen meta-bolism in Pyrens malus, L., that the transformation takes place forthe most part in the roots.Nitrogenous Metabolism in Underground Storage Organs.-1%.Gruntuch 68 has reviewed what little earlier work there is on thissubject and has carried out a long series of experiments with theunderground storage organs of many plants, chiefly with XohnurnNature, 1930,125, 168 ; A ., 376.65 N . J . Agric. Exp. Sta. Bull., 1928, No. 476 ; A., 607.66 Ibid., 1928, No. 472; A., 1929, 612.6 7 Science, 1927,66, 116; compare Ann. Reports, 1927, 24, 230.68 Planta, 1929, 7, 382BIOCHEMISTRY. 245luberosum, Helianthus tuberosus, Dahlia variabilis, and Asparagusoficinalis. He finds, as one would expect, that the total nitrogenin these organs varies greatly, not only in different plants, but alsoin the same plant a t different stages of growth. In spite of this theratio of protein/soluble nitrogen remains fairly constant. Griintuchconcludes that the metabolism of these storage organs remainsobscure, and is not to be compared with that of the ripening seed.69If nitrates (which Griintuch has not determined) are transformed inthe fibrous root, as discussed above, and do not accumulate in thestorage organs, then the soluble nitrogen is presumably all organicnitrogen, and it is possible that we are dealing here with some“ mass-action ” relation between protein and soluble nitrogensimilar to that postulated by L.R. Bishop 70 in the development ofthe reserve proteins in the barley grain.The R61e of Ammonia in Plant Metabolism.-In a series of paperspublished during the last thirty years D. Prianischnikov has deve-loped a theory, now generally accepted, that ammonia is the “ alphaand omega ” of nitrogen metabolism in the plant. Ammonia, how-ever, was never stored as such in the plant but was metabolisedto “ amides ” (asparagine and glutamine). If the carbohydratereserve in the plant was insufficient for this purpose, the plant rapidlydied.He considered, therefore, that ammonia was a plant poison,and that r‘ amides ” were an innocuous form of ammonia storage.’lIn a brilliant series of papers published during the last three yearsW. Ruhland and K. Wetzel have shown that in certain types ofplant-those with a very acid sap-these conditions do not hold,and that an accumulation of ammonia (as salts, not free) can occurto an extent hitherto considered improbable. Within the limits ofthis Report it is possible to give only a brief outline of the moreimportant of their results in as far as they relate to the metabolismof nitrogen.The high sap acidity (pE 1-54-1-56) of leaves of Begonia semper-$orens suggested that they might be used for investigations on themetabolism of organic acids.72 The following differences betweenthese leaves and those of normal acidity (pE 5-6.5) were observed.(1) If the leaves were kept in the dark, the respiratory quotientrose from an initial 1.1 to 1.47-1-85 at the end of 3 days. Normalleaves showed a fall*belowil.(2) They contained 20% of their dry weight as oxalic acid.E9 F. Czapek, ‘‘ Biochemie der Pflanzen,” 11,279.70 Ann. Reports, 1929, 26, 219.71 Biochem. Z., 1928,193,211; 1929, 207,341; A., 1998, 662; 1929, 728;72 W. Ruhland and K. Wetzel, Planta, 1926,1,658; H. Ullrich,ibid., p. 565.compare M. E. Robinson, New Phyt., 1929,88,11724G CHIBNALL AND PRYDE:(3) They contained 5-10 times the normal preformed ammonia,and the value increased threefold during the day.Whereas innormal leaves the value (soluble N - ammonia N)/amrnonia N wasusually about 50, in begonia it was only 2-3. If the leaves werekept in the dark a t 28-35' to bring about protein decomposition,the ammonia content rose enormously-in 106 hours to 30% of thetotal nitrogen, while the small initial amount of " amide " nitrogendisappeared. The deamination was accompanied by a parallelincrease in oxalic acid (the pH of the sap decreased to 1.3) so that theammonia was always present as ammonium oxalate, and at no timewas free ammonia poisoning possible. In normal plants, of course,the " amide " nitrogen increases in the dark, the ammonia remainingmore or less stationary.Ruhland and Wetzel therefore considerthat plants can be separated into two physiological types-" amide "plants and " ammonia " (or " acid ") plants.In further illustration of this new important observation may becited certain of their results with rhubarb (Rheum hybridurn h o ~ t ) . ~ ~The rhizome, which has only a slight acid reaction, contains " amide "nitrogen (20% of the total soluble nitrogen), much amino-nitrogen(50% of the total), and only traces of ammonia. The stalks of the veryyoung leaves synthesise protein rapidly from the amino-acids andamides translocated from the rhizome. This ceases as the leavesopen, and a little later, when the stalks are 15 cm.long, strongdeamination takes place. The fully grown stalks contain some 62%of their total nitrogen as ammonia, and if they are kept in the darkthis value may rise to 72%. Parallel with the production ofammonia during growth is the production of (chiefly) malic andsuccinic acids, which give place slowly, as the stalk ages, to oxalicacid; so that free ammonia poisoning is again prevented. BothZ-malic and dZ-malic acids are found and it is considered t h a t theinactive acid has been translocated from the rhizome, in which thismodification only is found, and that the active acid has arisen bydeamination of amino-acids, since the relative concentrations ofammonia and this active acid are nearly I : 1. It is interesting t onote that the leaf lamin=, which are much less acid than the stalks,contain the usual amount of protein (88-9170 of the total nitrogen)and only traces of ammonia.That " amide " plants can, in anemergency, mobilise ammonia is shown by some results of D.Prianischnikov, 74 in which the roots of certain embryos, after beingdipped in acid, gave off ammonia and, to a certain extent, neutralisedthe acid.Ruhland and Wetzel call attention to the close similarity between73 W. Ruhland and K. Wetzel, Planta, 1927, 3, 765; K. Wetzel, ibid.,74 Biochem. Z., 1928, 193, 211 ; A., 1928, 562. 1927, 4, 476BIOCHEMISTRY. 247the metabolism of these “ acid ” plants and that of Aspergillus nigergrowing on p e p t ~ n e , ~ ~ in which 78y0 of the soluble nitrogen is con-verted into ammonia and there is an equivalent production of oxalicacid.Another interesting pwallel is the production of dl-malic andZ-malic acid during the metabolism of rhubarb stalks and the pro-duction of both these acids by A . niger (p. 233).8’ynthesis of Protein in G e e n Leaves.-J. Bjorksth 7G has putforward some interesting views on the intermediary products ofsynthesis in leaves which are based on an entirely new method ofexperimentation. The intercellular spaces of leaves of wheatseedlings suffering from nitrogen starvation were injected withvarious nutrient solutions by the evacuation method. The proteinnitrogen (in mg. per 1 g. of dry leaf) was then compared every hourfor 6 hours with that of control leaves. As an efficient control sourceof nitrogen, 0-O1M-urea was used. Injection with hydrogenperoxide greatly increased the production of carbon dioxide, butprotein synthesis went on normally.Changing the acidity of thesolution between pH 4 and pH 8, or the osmotic pressure by addingpotassium, sodium, or chlorine ions, again had no effect on proteinsynthesis. As sources of carbon for protein synthesis, none of thesimple aliphatic or hydroxy-acids was of use. Pyruvic acid (butnone of its homologues) was, however, readily utilised, and as therewas no increase in carbon dioxide formation it would appear that theacid did not undergo decarboxylation. Of the sugars tried,only glucose was utilised. Aliphatic amines, amino-acids, andammonium salts of aliphatic organic acids were good sources ofnitrogen supply, nitrates less so, and cyclic products were notutilised at all.Hydrogen cyanide and nitrites, which Traub 77considered might be precursors of amino-acids, were not used assources of nitrogen.Bjorksthn discusses the various hypotheses that have beenadvanced to account for the synthesis of amino-acids in the light ofhis own results, and puts forward a new suggestion that the simplestbuilding stone for protein synthesis is a-aminoacrylic acid, formedby the condensation of enolic pyruvic acid and ammonia.In a second paper J. Bjorksthn and I. Himberg 78 discuss certainaspects of the rble of ammonia in protein synthesis. Injection ofetiolated wheat leaves with urea, acetamide, and butyramide leadsto protein synthesis but no increase in free ammonia.Under ethernarcosis, injection of urea leads to an increase of free ammonia, but76 W. Butkevitsch, Biochern. Z., 1922,129,445.7 6 Ibid., 1930,225,l; A., 1482.7 7 Compare M. E. Robinson, Biol. Reviews, 1930, 5, 126.78 Ibid., 1930, 225, 441248 CHIBNALL AND PRYDE:no such increase is produced by acetamide and butyramide. As faras is known at present, there is no enzyme which will hydrolyse theseamides, whereas, of course, urea is readily broken down by urease.They conclude, therefore, that ammonia plays no direct r6le inprotein synthesis from these amides, and postulate a mechanism bymeans of which the amides are condensed directly with pynivic acidto give a-aminoacrylic acid.They consider that urea can also condense directly with enolisedpyruvic acid to form a-aminoacrylic acid, which is of interestbecause G.Klein 79 has recently asserted that the major part of theurea in plants-and its wide distribution in small amounts is wellknown-is not free, but bound with formaldehyde or acetaldehydeas a ureide.Xitrogen Exchange in Phcrnts.-Certain aspects of this problemwere discussed in last year’s Report. During this year severalpapers have appeared, some of which favour the view that amidesare concerned chiefly with storage, and that organic nitrogen istransported as amino-acids. incontinuation of their researches on the cotton plant have traced themovements of nitrogen in the boll, and conclude from a study of thenitrogen gradients into the boll during growth that the organicnitrogen enters from the sieve-tubes as “ residual ” rather than as“ amide ” nitrogen.H. Engel 82 has made some interesting observ-ations on plants suffering from nitrogen starvation. Cut shootswere kept for some weeks with their ends in distilled water, and theflow of nitrogen between the older fully grown and the youngdeveloping leaves was observed. The older leaves suffered muchprotein decomposition, but the soluble nitrogen was decreased also,showing that the products of decomposition had been translocated.Engel discusses the variations found in the ammonia-, amide-, andwhat he refers to as amino-nitrogen, and concludes that the nitrogenfrom the older leaves has been translocated to the growing parts asamino-nitrogen.Single leaves were used in some experiments, so thematerial available for micro-chemical analysis was necessarily limited.His value for amino-nitrogen (total soluble N-ammonia N - twicethe amide N) is open t o criticism.83K. Mothes 8* has made somewhat similar experiments. Cuttobacco plants were kept for 5-6 weeks in air that was 70q4 satur-ated. The older leaves withered and lost the major part of their79 2. Pflanz. Dung., 1928, 12A, 390; Abstracts of Communications, 5thInternational Congress of Botany, Cambridge, 1930.E. J. Maskell and T. G. MasonAnn. Reports, 1929, 28, 216.81 Ann. Bot., 1930, 46, 657; A., 1323.*3 Compare H. R. Vickery, Ann. Reporfs, 1929,26, 21 2.84 Rer. deut. Rot. Qe.?., 1928, 46, 591.82 Plantn, 1929,7, 133BIOCHEMISTRY.249protein, while the young growing leaves were still green and turgidand were actively synthesising protein. His analyses led him tothe conclusion that the nitrogen was transported as amides from theold leaves to the younger. That the protein of old leaves-even inthe presence of abundant carbohydrate-is more labile than that ofyoung leaves was shown by K. Mothes in an earlier paper,85 so thatH. Engel's assumption that the nitrogen starvation leads to theprotein breakdown in his older leaves does not necessarily follow.H. L. Newby and W. H. Pearsall86 show that as the leaves of thevine and rhubarb become old the ratio of the protein to non-proteinnitrogen decreases, as also does the acidity of the sap.A study of the soluble nitrogen in the leaves of the soya beanduring development has been made by J.E. WebsterY8' and of theseasonal variations in the protein and soluble nitrogen in the matureleaves of three evergreen plants by H. Sattler.88Phnt Bases and Alkaloids.-Very little information on themetabolism of these substances in the plant is available, and therehas been during the past two years a welcome increase of researchdevoted to the subject. G. Klein and M. Steiner 89 have investigatedabout 100 species of plant. All of them contained ammonia, andabout 40 contained volatile arnines. Methyl-, dimethyl-, trimethyl-,isoamyl-, and isobrityl-amine were identified by microscopic methodsbased on experiments with synthetic products. The amountspresent ranged from 0.0005 mg.--0.2 mg.per 100 g. of fresh leaves.The authors consider that these volatile products are used to attractinsects, and that they may be used as a basis for the systematicclassification of plants. R. Kapeller-Adler and T. Csaf6 findmethylamine and trimethylamine in s e a - ~ e e d . ~ ~T. Weevers 91 has investigated the metabolism of caffeine andtheobromine of several plants. They are found in the wood, under-ground organs, and especially in leaves. The amount in the lastdecreases as the leaf ages and disappears before it dies. Weeversconsiders that when this happens the bases are not translocated assuch, but undergo degradation in the same way as protein. Excisedleaves of Ilex paragwriensis 92 St. Hill show an increase of caffeinein daylight and a decrease if kept in the dark.Excised leaves of thetea plant, when kept in water, accumulate xanthine equivalent to30% of the decomposed protein, an amount too large to permit theassumption that it has its origin in the leaf nucleo-protein. He con-8 6 Proc. Led8 Phil. Lit. Soc., 1930, Section 2, 81.89 Jahrb. wiss. Bot., 1928, 68, 602.8 5 Planta, 1926,1,472.87 Plant Physiol., 1928,3,31; A., 1929,612.Planta, 1929, 9, 315.90 Biochem. Z., 1930,224,378; A., 1484.91 Arch. nkerhnd. Sci., 1930, VIIB, 5,111.92 Proc. Acad. Sci. Amsterdam, 1929, 32,281250 CHIBNALL AND PRYDE :siders that xanthine and its derivatives are storage products, andthat their nitrogen can be utilised when occasion arises for proteinsynthesis.The position with regard to alkaloids is not yet so clearly defined.It will be recalled that Pictet considered them to be secondaryproducts formed by the plant to remove poisonous primary productsof metabolism.T. Weevers and H. D. van Oort 93 draw no definiteconclusions from their experiments with the leaves of Cinchonusuccirubia, Pavon. K. Mothes 94 shows that there is a small gradualincrease in nicotine as the leaves of the tobacco plant develop, butthe connexion, if any, between the synthesis of nicotine and proteinmetabolism is not clear.K. Mothes 95 has also investigated the metabolism of arginine inPinus spinea. The base was estimated as flavianate after prc-liminary precipitation with phosphotungstic acid. In view ofVickery's 96 results on the composition of the basic fraction fromalfalfa-which contained but very small amounts of arginine andconsisted chiefly of basic compounds of undetermined composition(some of which may be precipitated by flavianic acid)-it seems tothe Reporter that this method of analysis is unsound.It is interesting to note that a new base closely allied to argininchas been isolated by M.Wade 97 from the press juice of the water-melon (Citrullus vulgaris). Its constitution, x-amino-6-carbamido-valeric acid, NH,*CO~NH*[CH,],*CH(NH2)*C0,H, has been con-firmed by synthesis from ornithine, by way of dibenzoylornithine,6-amino-a-benzamidovaleric acid, and 6-carbamido- ct-benzamido-valeric acid.Carbohydrate Constituents of Plant Tissue."The structure of pectic acid, which is generally accepted as thebasis of all pectic substances, still provokes some discussion. Theformula of Nanji, Paton, and Ling,98 in which pectic acid is regardedas composed of 4 molecules of galacturonic acid, 1 molecule of gal-actose, and l molecule of arabinose combined in a hexa-ring, has beenquestioned by S.T. HendersonJs9 who obtained from flax a producthaving the composition of a galactose-tetra,galacturonic acid (i.e., con-93 Proc. Acad. Sci. Amsterdam, 1929, 32, p . 1.n4 Planta, 1928, 5, 563; Apoth.-Ztg., 1930,13, 3.9 5 Ylanta, 1929,7,685. s6 Ann. Reports, 1929, 26, 212.9' Proc. Imp. Acad. Tokyo, 1930, 6, 15; Biochem. Z., 1930, 224, 420; A.,B8 J . SOC. Chem. Ind., 1926,44,253~.99 J . , 1928,2117; A., 1928,1119.* The Reporter gratefully acknowledges assistance from Dr.H. W. Buston1224.in the preparation of this sectionBIOCHEMISTRY. 251taining no arabinose) and possessing all the properties of pectic acid.F. W. Norris 1 considers that the pectic acid of flax is of the normaltype, as indicated by the furfural and " uronic anhydride " content.Ehrlich 2 still describes as " pectic acid " a water-soluble compoundhaving the formula C41H60036, formed by the loss of 9 molecules ofwater from 4 molecules of galacturonic acid, 1 molecule of galactose,1 molecule of arabinose, 2 molecules of acetic acid, and 2 moleculesof methyl alcohol. This product was obtained in the form of acalcium magnesium salt, in association with an araban, by hot-waterextraction of beetroot residues.The presence of methyl alcoholresidues, and the solubility of the substance in water, seem toindicate that it is actually an intermediate between the completelydemethoxylated, insoluble pectic acid (C35H50033) of other workersand " soluble pectin " (containing 4 methoxy-groups). The presenceof acetic acid in the molecule has not been accepted by other workers.J. R. Bowman and R. B. McKinnis3 obtained from oranges anarabinogalacturonic acid, and by a similar process from apples adigalacturonic acid. These they regard as the nuclear units of therespective pectins. They suggest that the digalacturonic acidundergoes transition in nature to arabinogalacturonic acid (andpossibly to arabinose), and that pectins contain these acids invaxying proportions.Although the ring formula for pectic acid is now widely accepted,the relation between this acid and " soluble pectin " still presentscertain unexplained aspects. The action of weak alkali on pectinconsists mainly in a removal of the methyl ester groups, the finalproduct being the insoluble, completely demethoxylated pectic acid.It has been pointed out, howeverY4 that pectic acid and methylalcohol are not the sole products of the reaction, small amounts of ahemicellulose being invariably produced, a fact not accounted forby a simple saponification.may in partexplain this.By the action of sodium hydroxide solution (0-5-4%) at temperatures between 37" and loo", pectic acid was shown toundergo rapid decarboxylation, yielding products of a low " uronicanhydride" content-20yo instead of 70% in the case of onionpectic acid.These products were shown to resemble the hemi-celluloses in many of their properties. A similar decarboxylationwas demonstrated by F. V. Linggood,(j by heating pectic acid withThe results of E. J. Candlin and S. B. Schryver1 Biochem. J., 1929, 23, 195 ; A., 1929, 729.2 F. Ehrlich and F. Schubert, Ber., 1929,62, [B], 1974 ; A., 1929,1273.3 J . Amer. Chern. Soc., 1930,52,1209; A., 746.4 F. W. Norris, Biochern. J., 1926,19,676; A., 1926, i, 1226.5 PTOC. ROY. SOC., 1928, [B], 108,365; A., 1928, 1162.6 Biochem. J., 1930,24,262; A., 824252 CHIBNALL AND PRYDE:water under pressure. About 12% of the pectic acid was accountedfor as hemicellulose, the remainder being present possibly asdegradation products of sugars.Since the pectins and the hemi-celluloses have been proved to be closely related, the term '' poly-uronide " has been proposed to include both classes.An investigation on the hydrolysis of pectin by alkali has beenmade by A. G. Norman and J. T. Martin,' in an attempt to determinet'he mode of linkage between the individual members of the pecticacid ring. They pointed out that the pectin ring was extremelysusceptible to attack by weak alkali (e.g., 0.2% solution a t lOO"),indicating that the linkages between the units are probably unlikethose found in other polysaccharides such as cellulose and starch.They found that rupture of the ring proceeded more rapidly thanapparent decarboxylation, and criticised the conclusions drawn byCandlin and Schryver, since they were able to show that substancesother than hemicelluloses and uronic acids were formed, and werecapable of yielding large amounts of carbon dioxide with boilinghydrochloric acid.Work on somewhat similar lines was carried out by A.G. Normanand F. W. Norris,* who studied the oxidation of pectic acid byFenton's reagent. Pectic acid they proved to be readily oxidised,giving complex mixtures containing galactose and galacturonic acidresidues. Their products strongly resembled the hemicelluloses,and the authors put forward the suggestion that, in nature, thelatter may arise from the pectins by prolonged mild oxidation, ratherthan by decarboxylation.Certain of the gums have been shown tocontain uronic acid residues, and may be formed ~imilarly.~Attention has often been directed to the fact that tissues rich inpectin are poor in lignin, and vice versa, and the suggestion has beenmade that pectin is the precursor of lignin. No practical evidencehas been put forward in support of this view.While evidence has been furnished that the hemicelluloses arerelated to the pectins in that they are based on conjugated sugarand sugar acid residues, their structure remains undecided. F. W.Norris and I. A. Preece lo have isolated five types of hemicellulosefrom non-lignified tissues (wheat bran, maize cobs). Of these,hemicellulose A was precipitated from the caustic soda extract of thet,issue on neutralisation with acetic acid; hemicellulose B, by thcsubsequent addition of a half-volume of acetone ; and hemicelluloseC by excess of acetone. B and C were subdivided into fractionsI31 and C1 by precipitation with Fehling's solution, B2 and C27 Biochem.J., 1930, 24, 649; A., 966.9 A. G. Norman, ibid., 1929, 23,524; A., 1929, 856.10 Ibid., 1930,24, 69; A., 383; I.A. Preece, ibid.,p. 973; A., 1326.Ibid., p. 402; A . , 824BIOCHEMISTRY. 253remaining in the respective filtrates. Of these products, A washydrolysed to xylose ; B2 to glucose only ; B1 and C1 gave varyingamounts of xylose, methylpentose, and a uronic acid; C2 gavearabinose, methylpentose, and uronic acid. The uronic acidpresent was probably glycuronic acid.From a consideration of theamounts of pentose, etc., obtained, the hemicellulose molecule isevidently one of considerable complexity, B1 having a minimummolecular weight of 6500.In the case of the hemicelluloses from lignified tissue, M. H.O'Dwyer l1 showed that the methoxyl groups were of two types, oneof which was extremely resistant to hydrolysis, and therefore wasnot an ester group. The' hemicelluloses derived from timber are byno means of the same structure as those from non-lignified tissues,although extracted by similar means. The products from wood have,in general, a much higber uronic anyhdride content and are appar-ently more complex in nature. Other tissues (e.g., flax) yieldh emicelluloses containing varying proportions of uronic anhydrideresidues .99Certain substances intermediate between the pectic substancesand the simple sugar acids have been isolated and studied, notablyby F.Ehrlich.2 By careful hydrolysis of pectic acid, three isomerictetragalacturonic acids have been isolated, differing in their opticalproperties, reducing power, etc. These acids have been shown topossess a cyclic structure, only tetragalacturonic acid B having a freealdehyde group. Ehrlich 12 has described a new pectic enzyme,pectolase, isolated from old cultures of Perisporaceae and shown tobe present also in taka-diastase, diastase, and emulsin, which wasable to hydrolyse these cyclic acids to (mono) galacturonic acid andwas also able to liberate soluble pectic compounds from the insolubleprotopectin.Ehrlich has suggested that the cyclic tetragalacturonicacids are normal intermediates in the enzymatic degradation ofpectin.Constitution of Long-chin Fatty Acids from Natural Sources.I?. Francis, S. H. Piper, and T. Malkin 13 have synthesised then-fatty acids from C,, to C,,, and have made a study of the meltingpoints and X-ray spacings of the acids, their ,ethyl esters, and ofequimolecular mixtures of the acids. The melting points of the oddand the even acids lie on two smooth curves. Two important typesof spacing are given by each acid, and when these are plotted againstthe number of carbon atoms four straight lines are obtained, twol1 Biochem. J., 1928,22, 381; A., 1928, 669.l2 Celluloeechem., 1930,11,140,161; A., 1163.l8 PTOC.RoY.SOC., 1930, [A), 128,214; A,, 1161254 CHIBNALL AND PRYDE :belonging to the even and two to the odd carbon acids. Theauthors call attention to the fact that reliance cannot be placed onmelting point or " mixed " melting point for purposes of identi-fication. For instance, acids of carbon content 20 and 21 atoms,and the following mixtures, 21 + 22, 22 + 23, 22 + 23 + 24, allmelt between the limits 74.9" and 75.2". The X-ray spacings andmelting points of mixtures of known composition convince theauthors that a n-fatty acid cannot be considered pure unless it hasthe correct melting point and correct acid value and gives bothX-ray spacings. They have analysed arachidic, lignoceric, cerotic,and montanic acids prepared from various natural sources, and theacids obtained by oxidation of the alcohols present in Chinese waxand carnauba wax.All were shown to be mixtures of n-fatty acidsand there was no indication of the presence of so-called iso-acids.The authors show that by intense fractionation it is possible toobtain pure acids from natural sources. Samples of lignoceric acidprepared by Dr. Brig1 from beechwood tar and of cerotic acidprepared by Professor Holde from Chinese wax were shown to bepure n-tetracosanoic acid and n-hexacosenoic acid respectively.Glutathione.Conclusive evidence has now been obtained that this tripeptide isy-glutamylcysteinylglycino,HO,C*CH( NH,) *CH,*CH,*CO*NH*CH( CH,*SH)*CO*NH*CH,*CO,H ,by E. C. Kendall, H. L. Mason, and B.F. McKenzie.l* If glutathioneis first oxidised to the corresponding sulphonic acid by means ofbromine, and then treated with sodium hypobromite, it yields onemolecule of carbon dioxide and a substance from which, before orafter further treatment with nitrous acid, succinic acid and glycineare liberated by hydrolysis with hydrochloric acid. If glutathioneis oxidised with hydrogen peroxide in the presence of ammonia,succinic acid is not liberated by the oxidation, but a significantpercentage of the total glutamic acid can be separated as succinicacid after hydrolysis. Also, if glutathione is treated with nitrousacid and then with alkaline hypobromite, succinic acid cannot beisolated until after hydrolysis. Finally, if glutathione is oxidisedwith chloramine-T, the mononitrile of succinic acid is not liberatedin significant amount, but succinic acid can be recovered afterhydrolysis. These reactions show that glutathione must be either( 1) glutamylglycylcysteine or (2) glutamylcysteinylglycine, the freeamino-group of the glutamic acid being in the y-position to thepeptide linkage.Since the product of interaction of glutathioneethyl ester hydrochloride with magnesium phenyl bromide yields,1 4 J . Biol. Chm., 1930,87,66; 88, 409; A,, 946, 1299BIOCHEMISTRY. 255on hydrolysis, diphenylacetaldehyde, it is probable that the carboxylgroup of the glycine is free, and constitution (2) the correct one.It will be recalled that (Sir) F. G. Hopkins l5 showed that whenglutathione was boiled in aqueous solution much decompositionoccurred, and together with unidentified products the diketo-piperazine of glycine and cysteine (or, in the case of the disulphideform, diglycylcystine dianhydride) was isolated.Kendall and hisco-workers find that, by heating glutathione in aqueous solution at62" for 120 hours, hydrolysis to pyrrolidonecarboxylic acid and adipeptide of glycine and cysteine occurs. On treatment of the latterwith sodium hypobromite or with nitrous acid, followed by acidhydrolysis, glycerol was isolated, though in poor yield. The dipep-tide was next oxidised to the disulphide, this condensed with2 : 3 : 4-trinitrotoluene, and the product hydrolysed with hydro-chloric acid. Glycine was again isolated, showing conclusivelythat the dipeptide was cysteinylglycine, and that glutathione mustbe y-glutamylc ysteinylglycine .Additional evidence that glycine occupies a terminal position inthe molecule has been furnished by B.H. Nicolet.ls Glutathionewas condensed directly with ammonium thiocyanate and aceticanhydride to give a compound C,,H,,O,N,S,. This was condensedwith benzaldehyde in the presence of acetic acid and sodium acetateto give a, compound which, when hydrolysed with sodium hydroxide,gave a 50% yield of benzylidenethiohydantoin. The compoundC1,Hl,O,N,S, is therefore regarded as a bisthiohydantoin, in theformation of one of the thiohydantoin groups of which glycine musttake part. It follows, then, that glycine occupies a terminal positionin the molecule.W.Grassmann, H. Dyckerhoff, and H. Eibeler l7 show thatglutathione is not hydrolysed by pepsin, pancreatic proteinase,papain, or the dipeptidase and aminopolypeptidase from yeast andintestine. It is, however, readily attacked by pancreatic carboxy-polypeptidase, which hydrolyses only one peptide linkage, yieldingthe total glycine in the free state and a peptide residue recovered in90% yield. They consider that this shows the glycine to be at theend of the chain and that the carboxyl group is free.This clarification of the chemical nature of glutathione has,unfortunately, introduced considerable uncertainty as to its actualphysiological r6le in the pure condition. The earlier preparationspossessed such characteristics as constituted glutathione a chemicalcatalyst in the interaction between atmospheric oxygen and fats,l6 Ann.Reporta, 1929,26, 222.1@ J . Biol. Chem., 1930, 88, 389; A., 1299.l7 2. physiol. Chem., 1930,189, 112; A., 1067256 CHIBNALL AND PRYDE :proteins, and the " insoluble, thermostable residue ? ' left afterexhaustive extraction of tissue.18 All of these substances areoxidised in the presence of impure glutathione, which in turn isre-oxidised by oxygen gas. N. U. Meldrum and M. Dixon,19 how-ever, now indicate that glutathione when pure possesses theseproperties only in respect of the fats, where its catalytic activity isknown to occur a t an acidity not found in animal tissues. Itappears that in all preparations of glutathione there exists in varyingdegree some hydrolytic product to which, in the presence of iron orcopper ions, the autoxidisability of reduced glutathione must beattributed.Pure glutathione even in the presence of iron is notautoxidisable. Neither are other cysteine peptides. Nevertheless,the evidence presented by these authors indicates that the fissionproduct is closely comparable in properties with cysteine itself.Thus, though existing evidence as to the function of the thiol groupin conjunction with iron in a respiratory capacity is in no wayaffected, the actual participation of the tripeptide, glutathione, inthis capacity has become much open to question.Recent attempts to show the presence of glutathione in planttissues are not very convincing.20Muscle Contraction.The investigation of the physical and chemical processes whichconstitute the mechanisms of muscle contraction continues toabsorb much of the energies of biochemists.In recent yearsconsiderable information concerning the chemical nature of thesubstances participating in the muscle process has accumulated,but the more purely physical side has been somewhat neglected.In a highly interesting series of studies of the physical chemistryof muscle globulin, J. T. Edsall 21 directs attention to this neglectwhen he says : " Knowledge of the energy-liberating reactions inmuscle has made enormous strides in the past 20 years, and farsurpasses our knowledge of the machinery which they set in motion.It seems beyond doubt that the proteins play a large-if not thelargest-part in this machinery. It is to be expected that thephysico-chemical properties of the isolated protein will be foundintimately related to its function within the muscle fibre." Edsalldescribes the preparation of muscle globulin, which is regarded asidentical with the myosin of Danilewsky, von Fiirth, and Weber,and with the paramyosinogen of Halliburton, although the terml 8 Ann.Reports, 1925,22, 225. lS Biochern. J., 1930, 24, 472; A., 803.2o W. H. Camp, Science, 1929, 69, 455; A., 1929, 1499; V. B. White, ibid.,z1 J . Biol. Chem., 1930,89,259.1930,71,74; A., 826BIOCHEMISTRY. 257myosin is reserved, in a later paper of the series, for the anisotropicprotein responsible for the double refraction of flow. Muscleglobulin, if kept in the cold, protected from bacteria, dissolved insalt, at pH 6.5 to 7-5 preserves its properties unchanged over aperiod of several months.The protein is insoluble in all salt con-centrations between pu 5 and 6, but it possesses an extraordinaryaffinity for water, from which it cannot be separated without someradical change in the protein itself. Even concentrated precipitatesof the protein contain 98% of water, and it remains undenaturedonly in the presence of a large amount of water. This phenomenonmay, as Edsall suggests, have a special physiological significance,since it has been recorded that no significant change occurs in thewater content of skeletal muscle, even in cases of profound dehydr-ation, when the fluid of the intercellular spaces is greatly depletedand the blood volume is diminished well below normal.Whenmuscle weight is lost, proteins and salts are lost along with thewater removed. In other words, the muscle appears to lose waterto any extreme degree only when the protein is broken up and lostas well. The behaviour of muscle globulin suggests that the wateris directly held by the protein, and that this water-holding poweris not lost when the protein is extracted from the muscle.In two further communications A. L. von Muralt and J. T.Edsall22 have published many interesting observations on thephysical properties of muscle globulin. It is found that the proteinshows double refraction of flow, which is ascribed primarily to theorientation of anisotropic particles and secondarily to photo-elastic phenomena. Apparatus is described for measuring theangle of isocline (the angle at which the arms of the black crossappear when polarised light is passed through a solution of theprotein in a rotating cylinder).The measurements of the angleof isocline are interpreted as indicating a monodisperse system,that is, the muscle globulin particles are of uniform shape and size.The angle of isocline of muscle globulin solutions is independent ofage. After repeated washing of the muscle globulin solution, thepreparation becomes practically salt-free and forms a clear geleven a t an extremely low protein concentration (about 0.3%).Merely by vigorous shaking, this gel is transformed to the fluidstate and sets again to a gel in a few minutes.It is therefore athixotropic gel.23The double refraction of flow shown by muscle globulin solutionsis intimately related to the chemical nature of the protein solution,22 J . Biol. Chem., 1930, 89, 315, 351.23 A. Szegvari and (Frl.) E. Schalek, KoZEoid-Z., 1923, 32, 318; 33, 326; A,,1923, ii, 423 ; 1924, ii, 116.REP.-VOL. XXVII. 258 CHIBNALL AND PRYDE :Thus it is found that typical denaturing agents produce rapid andcomplete destruction of the double refraction of flow, which appears,therefore, to be a property only of the undenatured protein. Fromthe work of H. StuebelZ4 it has been inferred that oriented rod-shaped particles, small compared with the wave-length of light,are present in the intact muscle and are responsible for its doublerefraction.The double refraction and other properties of myosinsolutions indicate that they may contain these rod-shaped particles,and also point to the probable location of the myosin in the aniso-tropic disc of the cross-striated muscle fibre. It seems highlyprobable that these remarkably interesting investigations mayelucidate new aspects of the functional activity of the muscle, andin any case they constitute a new and welcome attack, by estab-lished methods of physical science, on this very complex biologicalproblem. Similar remarks may be made concerning the investig-ations of G. Boehm and K. I?. S c h o t ~ k y , ~ ~ who have obtainedX-ray diagrams of living muscle in a state of rest and of excitation.Despite the wealth of new discoveries made in recent yearsconcerning the chemical processes of muscle contraction, somerecent observations of 0.Meyerhof 26 suggest that there are stillmaterial gaps in our knowledge. Meyerhof has employed a thermo-electric method for measuring the depression of freezing point ofmuscle in fatigue and in rigor. I n prolonged fatigue and rigor theobserved depression is some 30% greater than would be expectedon the basis of the known products of hydrolysis, Similar con-clusions are reached by A. V. Hill and P. s. Kupalov,27 who findthat the increase of osmotic pressure in the fluids of a stimulatedmuscle is about 2.8 times as great as would be exerted by thelactate ions produced, if dissolved in the “free” water of themuscle.It is 1.8 times as great as would correspond to the lactateions together with the creatine liberated by the breakdown ofphosphagen, and is appreciably greater than can be accounted forby all the chemical changes at present known, or suspected, tooccur in stimulated muscle. A. V. Hill 28 defines the “ free ” waterfraction as the weight of water in 1 gram of fluid or tissue whichcan dissolve substances added to it with a normal depression ofvapour pressure. The “ free ” water fraction of frog’s muscle,whether resting or in rigor, is about 0-77, or perhaps a little greater,the total water fraction being 0.80 or 0.81. On the other hand,0. Meyerhof and F. Lipmann 29 find that the pH change observed2 5 Naturwiss., 1930,18, 282; A,, 637. 24 Arch.ges.Physiol., 1923,201,629.26 Biochem. Z., 1930, 226, 1 ; A., 1614.2Q J . Physiol., 1930, 69, Proc. XXI; A., 1211; Naturwiss., 1930, 18, 330;Proc. Roy. SOC., 1930, [B], 106, 446. 28 Ibid., p. 477.A., 810BIOCHEMISTRY. 259in a muscle during a prolonged series of twitches agrees well withthat calculated from the lactic acid formed and the phosphagensplit. The muscle at first becomes more alkaline and only in anadvanced state of fatigue does it become more acid. The explan-ation of the phenomenon is found in the fact that the breakdownof creatinephosphoric acid, which in the first stages of fatigue islarge compared with the simultaneous formation of lactic acid,increases the amount of basic equivalents.Muscle Contraction without Production of Lactic Acid.-In thefield of muscle chemistry one of the most interesting and significantdiscoveries announced during the past year concerns the action ofiodoacetic acid on the lactic acid formation of contracting muscle.Early in the year it was announced by E.Lundsgaard30 that thepost-mortem formation of lactic acid in the muscles of rabbits andfrogs poisoned by sodium iodoacetate was completely inhibited.At the same time the contractile power of the muscle did not sufferdamage. Muscles treated with sodium iodoacetate will contractwith a hydrolytic cleavage of the phosphagen, which takes placeeven more rapidly than in normal muscle, and without lactic acidformation. After total breakdown of the phosphagen the muscleremains in a state of contraction.The phosphoric acid of thephosphagen is, under these conditions, rapidly and completely con-verted into hexosephosphoric acid. On the basis of these observ-ations it was suggested that phosphagen might be the energy-producing substance in muscle activity, and that the productionof lactic acid might cause progressive resynthesis of the hydrolysedphosphagen. Later, Lundsgaard showed that the anaerobic re-synthesis of phosphagen was abolished after the muscle had beentreated with iodoacetate, but on the other hand, in the presenceof oxygen, the poisoned muscle did more work than under anaerobicconditions and showed a smaller diminution in phosphagen content.This result is ascribed to oxidative resynthesis of phosphagen.Thechronaxie of the poisoned muscle is normal. 0. Meyerhof, E.Lundsgaard, and H. Blaschko31 have shown, by a comparison ofthe total anaerobic development of tension with the decompositionof phosphagen, that the whole of the energy for anaerobic con-traction with the poisoned muscle is derived from phosphagen.Reference has already been made to the observations of Meyerhofand Lipmann on the change of pH during muscle activity. Asmight be anticipated these observers 32 have demonstrated that inthe presence of iodoacetic acid only the alkaline phase of the change30 Biochem. Z., 1930, 217, 162; A,, 368.31 Naturwiss., 1930, 18, 787; A., 1312.Biochem. Z., 1930, 227, 84260 CHIBNALL AND PRYDE :is observed, and that when the muscle is arrested in contracturethe alkalinity is maximal.Two further communications by Lundsgaard 33 extend theseremarkably interesting observations.It is shown that iodoaceticacid completely inhibits alcoholic fermentation by living yeastand by zymase preparations, but in neither case is hexosephosphoricacid formation observed. The actions of invertase, ptyalin, andcatalase are not affected by iodoacetic acid. I n general, in thepresence of iodoacetic acid, oxidative processes involving carbo-hydrates are able to proceed normally after glycolysis is completelyinhibited.34I n addition to these observations concerning the energy sourcesof muscle contraction, a recent paper by G. Embden and E. Metz35directs attention to the fact that bromo- and iodo-acetic acidscause a marked diminution in the solubility of the muscle proteins,similar to that observed by H.J. Deuticke36 in fatigued muscles.It would appear to be highly probable that the halogenated aceticacids are destined to be of great service in elucidating, and possiblyeven in revolutionising, the complex chemistry of the muscleprocesses.It has been recognised for many years that fluorides inhibitfermentation and glycolysis, and F. Lipmann37 has pointed outthat, if muscles are poisoned with fluoride in such concentrationas to leave unimpaired their contractile power, such contractionshould occur without lactic acid formation. This he shows to bethe case, the contraction occurring with decomposition of phos-phagen, esterification of hexose with phosphoric acid, and hydrolysisof adenylpyrophosphoric acid.The mechanism of the action ofiodoacetic acid and of fluoride on the lactic acid-forming fermentcomplex is similar, save that the former acts slowly and is irre-versible, whereas the latter acts instantaneously and is reversible.Phosphagen.-Continuing his observations already summarisedand in support of his views 38 regarding the relation between phos-phagen and rate of excitation, D. Nachmansohn39 has shown thatthe increased extent of decomposition of phosphagen caused byveratrine is exactly proportional to the increased rate of excitationcaused by the drug. On the other hand, curare and the ammoniumbases generally produce a marked reduction in the extent of decom-position, the greatest effect in this respect being observed withtrimethyloctylammonium iodide.This base has been used by33 Biochem. Z., 1930, 220, 1, 8 ; A., 958, 954.3 5 2. physiol. Chem., 1930, 192, 233.3 7 Biochem. Z., 1930, 227, 110. ** Biochern, Z., 1929, 213, 262; A., 1929, 1484.34 Ibid., 1930, 227, 51.36 PJEiiger’s Arch., 1930, 224, 1.3a Ann. Reports, 1929, 26, 232BIOCHEMISTRY. 2610. Meyerhof and D. Nachmansohn 40 in investigating the synthesisof phosphagen in living muscle. It is found that the anaerobicresynthesis of phosphagen in living muscle after decompositionduring tetanus is as great, expressed absolutely, in muscle poisonedwith trimethyloctylammonium iodide as in the unpoisoned muscle,but is much greater when expressed as a percentage of the totaldecomposition.Aerobic resynthesis of phosphagen is observed tooccur both after previous decomposition on admission of oxygen,and without previous decomposition when the muscle is placedin Ringer's solution saturated with oxygen, especially after additionof phosphate. The aerobic resynthesis after previous decompositionproceeds more quickly and completely at lower temperatures andmost quickly at - 0.5" to -- 1". The molecular ratios, phosphatesynthesised : oxygen used, and phosphate synthesised : lactic aciddisappearing, both give values of 5.B. Kisch41 has published some interesting observations on theoccurrence of phosphagen in the electric organ of Torpedo. Theamount present is found to be about the same as that of the generalmusculature.In the fresh unstimulated organ 77% of the phos-phorus of the acid extract is present as phosphagen. Duringactivity of the organ and during asphyxiation the amount of phos-phagen rapidly diminishes, but resynthesis occurs during rest inthe presence of oxygen. Thus the analogies between the electricorgan and the skeletal muscles developed on morphological groundsare supported by these biochemical observations.The Adenylic Acid Complex of Muscle.-There is now a generalacceptance of the view that the adenine present in an aqueousextract of muscle occurs as a nucleotide. The observations ofK. P ~ h l e , ~ ~ A. Dmoch0wski,4~ and P. Osterna are in accord inthis respect, and the further association of the nucleotide (adenylicacid) with pyrophosphoric acid, an association first indicated byK.L0hrnann,4~ is supported by the data of C. H. Fiske and Y.S~bbarow.*~ The last-mentioned observers do not regard adenylicacid as such, as a normal constituent of muscle, but find it to be adecomposition product of a substance which is precipitated as thecalcium salt from a protein-free muscle filtrate. This substanceyields adenine, carbohydrate, and three molecules of phosphoricacid, two of which are readily removed by acid hydrolysis.Concerning the significance of adenylic acid as the source of40 Biochem. Z., 1930, 222, 1 ; A.. 1210.42 2. physiot. Chem., 1929, 185, ! f ; A., 1929, 1479.43 Biochem. J., 1929, 23, 1346; A., 1930, 238.44 Biochem. Z., 1930, 221, 64; A ., 945.*1 Ibid., 1930,225,183; A., 1464.46 Ann. Repwt-s, 1929, 26, 231.S&ence, 1929,70, 381 ; A., 1930, 492262 CHIBNALL AND PRYDE:muscle ammonia, G. Embden and G. Schmidt47 have publishedsome convincing data. The enzymes of fresh frog-muscle weredestroyed by acid treatment and the muscle was exposed to theaction of an enzyme capable of deaminising muscle adenylic acidonly.48 The ammonia eliminated by this procedure correspondswith that obtained by exposing the minced muscle for 3 to 4 hoursin a slightly alkaline solution. It is concluded, therefore, that theammonia formed in a short autolysis of frog’s muscle is derivedexclusively from the muscle adenylic acid, and that it is now possibleto exclude even adenosine as a possible source. Adenylic acid mayparticipate in reactions involving more profound degradation ofits molecule than this deamination.In some of the results pub-lished by G. Embden, J. Hefter, and M. Lehnartz49 there is asuggestion that a t the moment of contraction a fission of adenylicacid, or of its deamination product, inosinic acid, may occur withthe formation of orthophosphoric acid, and K. Pohle 50 has sug-gested adenylic acid as a possible precursor of endogenous uricacid.Adenylic Acid and the Kidney .-Considerable interest attachesto the occurrence and functions of adenylic acid in kidney tissue.G . Embden and H. J. Deuticke 51 have isolated the acid from thissource and shown it to be identical with that obtained from muscle.It is acted upon by the specific deaminase of rabbit’s muscle.B. E.Holmes and A. Patey 52 have studied the ammonia-forming systemswhich occur in washed kidney tissue. One of these acts aerobicallyand has an optimum of pIl 5.2 or lower. A second aerobic system,acting upon glycine, and an anaerobic system are also shown to bepresent in the kidney.53 It is suggested that the first-mentionedsystem is concerned in the normal production of ammonia by thekidney, as this is known to be greatest when the urine is acid. Itis not yet possible to state whether or not adenylic acid is theammonia-precursor in this system. There is, however, generalagreement that adenylic acid can be completely deaminated underanaerobic conditions. Therefore, although it may be the sourceof some of the ammonia in the urine, it cannot be the substrate ofthe particular aerobic system studied, and the pH optimum curvesdo not suggest that it is the substrate for extra ammonia formationin the case of an acid urine.47 2.physiol. Chem., 1930, 186, 205; A., 494.40 Ann. Reports, 1929, 26, 228.49 2. physiol. Chem., 1930,187, 53; A., 637.61 2. physiol. Chem., 1930, 190, 62; A., 1203.52 Biochem. J., 1930, 24, 1664; A., 1614.LOC. cit.A. Patey and B. E. Holmes, ibid., 1929,23, 760; A., 1929, 1194BIOCHEMISTRY. 263Enzymic Hydrolysis of Glycogen.A. D. Barbour 54 records the hydrolysis of glycogen by means ofa glycerol extract of fresh muscle or liver tissue. The hydrolysisis carried out for 5 hours at the optimum pH of 6-3.The soleproduct of the action of the muscle extract upon the glycogen is atrisaccharide, C,,H,,016, having + 181", and 30% of thereducing power of glucose. It is readily converted into the anhydro-trisaccharide, C18H3,-,01,, having + 187", and 8.5% of thereducing power of glucose. The digestion of glycogen by salivaryor pancreatic amylase appears to follow a course different from thatof the muscle and liver enzymes. Attempts to use the enzyme forthe synthesis of glycogen from the trisaccharide and its anhydro-derivative were not successful. If the trisaccharide can be obtainedin reasonable amount, it would become a matter of great interestand importance to subject it to the recognised methods of structuralinvestigation in the sugar group, more especially in view of theapparent chemical identity of trimethyl glycogen and trimethylstarch.55 It is of interest to recall here the preparation fromglycogen by H.Pringsheim and G. Will 56 of a trisaccharide deriv-ative which they called glycogesan. It was obtained by chemicalmeans. Under the influence of pancreatic amylase, glycogesanwas degraded to maltose, fission being practically quantitative ifyeast complement was added. Although glycogesan behaved as atrisaccharide on cryoscopic investigation, the facts that it formeda colloidal solution in boiling water and possessed the same opticalactivity and iodine colour reaction as glycogen suggest that it hasa greater molecular complexity than the trisaccharide described byBarbour.Alcoholic Fermentcttion.In an important paper by R.Robison and W. T. J. Morgan 57on the phosphoric esters of alcoholic fermentation a detailed de-scription is given of the met,hods of fermentation and separationemployed. The details will be of great service to other workers inthis field. The distribution of the total esterified phosphorusamongst the four known esters is given for a number of fermentationexperiments with yeast-juice, zymin, and dried yeast. There is54 J . Biol. Chem., 1929, 85, 29; A., 1930, 249.55 W. N. Haworth, E. L. Hirst, and J. I. Webb, J., 1929, 2479; A., 1930,72.Ber., 1928, 61, [B], 2011; A., 1928, 1225.57 Biochem. J., 1930, 24, 119; A., 374264 CHIBNALL AND PRYDE :appended a table, taken from this paper, which records analyticaldata of the barium salts of these esters :P, %.Ester.Barium fructosediphosphate 10.16phate ............... 7 .85,, glucosemonophos-,, fructosemonophos-,, trehalosemonophos-phate (Neuberg) ... 7-85phate ............... 5.57Reducing poweras glucose. SeliwanoffH. and Iodine, fructose,12 2 10 + 3.5"36 41 0 +19*5J., %. %. %-22 + 0.7 2 360 0 0 +132In the course of this work some indication has been obtained ofthe existence of a fifth ester, forming, at most, only a very smallproportion of the fermentation products. Following on the dis-covery of pyrophosphate as a constituent of muscle,58 E. Boyland 59has shown that it also occurs in living yeast and forms about one-fourth of the total phosphorus.Pyrophosphate added to ferment-ing zymin is rapidly hydrolysed to orthophosphate, which thenreacts in the usual way. Evidence is obtained of the presence inyeast of a pyrophosphatase which is distinct from hexosephos-phatase. The distribution of phosphorus compounds in freshEnglish brewer's yeast (as mg. of phosphorus per g. of yeast) isgiven as follows:Total phosphorus ............ 3.25 Hexosediphosphate ......... 0.38Orthophosphate ............... 1.37 Hexosemonophosphate ...... 0.72Pyrophosphate ............... 0.68 Nucleic acid .................. 0.07Organic phosphorus .......... 1.17A. Harden and M. G. Macfarlane 6O have made experiments inwhich mixtures of sand and yeast were ground for different periodsand the resultant total mass, without pressing out, was tested forthe rate of fermentation and response to phosphate.At least 80%of the diminution in the rate of fermentation which occurs is ascribedto the process of grinding, during which the yeast acquires thepower of responding to phosphate. The conclusion is drawn thatthe grinding process mainly affects the mechanism of hexosephos-phatase action. M. G. Macfarlane 61 has published a study of theaction of disodium arsenate on hexosephosphatase in which it isshown that the accelerating action takes place only in the presenceof yeast extract and cannot be obtained without an accompanyingfermentation. Although this observation does not elucidate themechanism of the accelerating action of arsenate, it does dispose59 Biochem.J., 1930, 24, 350; A., 817.Ibid., p. 1051; A., 1317.68 Ann. Reports, 1929, 26, 230.6o Ibid., p. 343; A., 818BIOCHEBIISTRY. 265of earlier theories which ascribed it to a direct effect upon thehydrolysis. In relation to tlhis question it is significant that K.Lohmann 62 has found that! the hydrolysis of Robison’s mono-phosphoric acid ester in frog-muscle pulp is accelerated by arsenateonly after the mono-ester hsts been further esterified to form theHarden and Young di-ester.The Sugar of Animal Nucleic Acid.During the past year the long-debated problem of the nature ofthe sugar component of animal nucleic acid would at least appearto have been settled. The fission of animal nucleic acid into itscomponent nucleotides presents much more difXculty than isencountered in the case of the plant acid.But despite thesedifficulties P. A. Levene and E. S. London63 have succeeded ineffecting this disruption and in isolating guanine nucleoside togetherwith smaller quantities of hypoxanthine, thymine, and cytosinenucleosides. Using combined gastric and intestinal fistuh, theysubjected solutions of animal nucleic acid to the action of theintestinal juices of the dog in vivo and subsequently for longerperiods in vitro, or alternatively the juices were collected from thefistulze and added to solutions of nucleic acid. Levene and London 64prepared from guanine nucleoside a sugar having the compositionof a deoxypentose, C,HIoO,, to which, pending its identification,they gave the name thyminose. It gave with Kiliani’s reagent thespecific colour reaction for this type of sugar, and a Willstatter-Schudel iodometric oxidation proved it to be an aldose.It formedlaevulic acid on being treated with sulphuric acid and was there-fore a straight-chain pentose. The later work of P. A. Levene andT. M ~ r i , ~ ~ and of P. A. Levene, L. A. Mikeska, and T. Mori 66 ledto the identification of thyminose as d-2-deoxyribose :qH( OH)*CH,*CH( OH) *CH( OH)*qH2The new sugar is therefore it reduction product of the pentose ofplant nucleic acid. It affords, so far as the Reporter is aware,the first instance of the occurrence of a deoxy-sugar in a naturalproduct.The Sugar of Pentosuria.--The possible relationship of the newsugar of animal nucleic acid to the sugar of pentosuria must forthe present remain speculative.In the past this sugar has been6* Biochem. Z . , 1930, 222, 324; A., 1210.63 J . Biol. Chem., 1929, 81, 711; A., 1929, 590.84 Ibid., 1929, 83, 793; A,, 1929, 1322.85 Ibid., p. 803; A., 1929, 1277. g6 Ibid., 1930, 85, 786; A., 455.I 266 CHIBNALL AND PRYDE :variously identified as dl-arabinose, I-arabinose, dl-ribose, I-ribose,d-xyloketose, or simply as a d- or an I-rotatory pentose. In viewof these curious variations, but more especially in view of the greatinterest of Levene’s new results, a re-examination of all the avail-able data seems desirable. During the past year two studies ofthe sugar of pentosuria have appeared. I. Greenwald,67 on thebasis of four cases, identifies the sugar as d-xyloketose, and P.H&ri,6* with five cases a t his disposal, finds that the sugar belongsto the xylose group but does not record very convincing evidenceregarding its optical rotation.It is perhaps worthy of note thatH. 0. Calvery G9 has isolated adenosine (adenine-d-riboside) fromnormal human urine. No trace of the phosphorylated compound(adenylic acid) was detected. The adenosine was isolated from amixed urine and the yield was small, so the nucleoside might easilyhave had its origin in the urine of a few individuals, and thereforemay not be of common occurrence. Its presence in urine maybear some relationship to the uric acid-pentose compound firstreported in urine by A. R. Davies, E. B. Newton, and S.R. Bene-dict. 70The Xugars of the Tubercle Bacillus.In the Reports for 1926 71 and 1929 72 attention was directed tothe important r6le of carbohydrates in immunological reactions.The work there summarised dealt mainly with the sugars of thepneumococcus group of organisms. In the past year much inform-ation has accumulated concerning the similarly specific sugars ofthe tubercle bacillus. From tubercle bacilli propagated in asynthetic, sugar-free medium and also from tuberculin, M. Maxim 73has isolated a polysaccharide which on hydrolysis yields d-mannoseand d-arabinose. The same two carbohydrates are reported byA. G. Renfrew 74 to be present in the polysaccharide isolated fromLong’s synthetic media in which tubercle bacilli had grown.P.Masucci and L. K. McAlpine 75 likewise confirm this and in additionfind an unidentified sugar acid. E. Chargaff and R. J. Anderson 76record the presence of mannose and arabinose together with galactoseand inositol in the polysaccharide extracted by toluene along withthe lipoids of the ehtire bacilli. R. J. Anderson and E. G. Roberts 7767 J . Biol. Chem., 1930, 88, 1 ; A., 1311.6 8 Biochem. Z., 1930, 224, 474; A., 1469.69 J . Biol. Chem., 1930, 86, 263; A., 633.71 Ann. Reports, 1926, 23, 248.73 Biochem. Z., 1930, 223, 404; A., 1219.74 J . Biol. Chem., 1930, 89, 619.7 6 Amer. Rev. Tuberculosis, 1930, 22, 678.7 6 2. physiol. Chem., 1930, 191, 172.70 Ibid., 1922, 54, 595.72 Ibid., 1929, 28, 239.7 7 J . Biol. Chern., 1930, 89, 611BIOCHEMISTRY.267find glucose, mannose, and inositol in the sugar fraction of thetubercle phosphatide described in the Report of last year. Theoccurrence of d-arabinose in these sources is of interest, sinceZ-arabinose is the usual variety found in nature. A useful reviewof the present state of these investigations will be found in thearticle by T. B. Johnson and A. G . R e n f r e ~ . ~ ~ The polysaccharideexamined by Redrew gave precipitin reactions a t a dilution of1 in 1,500,000, from which it may be inferred that the tuberclepolysaccharide is functionally similar to those of the pneumococci.A study of the molecular size of the specific polysaccharide ofType I11 pneumococcus has been made by F. R. Babers and W. F.G~ebel,’~ using the diffusion method of Northrop and Anson.80The result gives a molecular weight of 118,000.Incidentally thesame method has been applied by P. A. Levene and A. Rothen 81to the polysaccharide of ovomucoid, which appears to consistexclusively of glucosamine and mannose. The result in this caseindicates a molecular weight of 2000 and it is inferred that thepolysaccharide consists of four trisaccharide units each containing1 molecule of glucosamine and 2 molecules of mannose.The Reducing Xubstances of Blood.In view of the widespread use of various techniques for deter-mining the reducing substances of blood (usually referred to as‘‘ blood sugar ”) a paper published by J. M. Gulland and R. A.Peters 82 will be of interest. In this a study is recorded of thereducing substances of pigeon’s blood.It has frequently beenobserved that the total reducing value of avian blood determinedby the usual methods is considerably higher than that of mammalianblood. For instance, for normal hen’s blood the Hagedorn andJensen method has given values as high as 0.253%, which wouldappear to place normal avian blood within the range of humandiabetic values. Gulland and Peters find in pigeon’s blood (by thesame method) an average of 0.200%, of which only 0.135 5 0.015%can be regarded as glucose or similar reducing hexoses. Bloodfiltrates prepared by different, methods contain different proportionsof ergothioneine, uric acid, and glutathione, or other aliphaticsulphhydryl compounds. Zinc filtrates made by the Hagedorn andJensen method, which do not contain aliphatic sulphhydryl com-pounds (an observation confirmed by M.R. Everett 83), are the78 Amer. Rev. Tuberculosis, 1930, 22, 665.79 J. BioZ. Chem., 1930, 89, 387.81 J . Biol. Chem., 1929, 84, 63; A., 1929, 1478.*a Biochem., J . 1930, 24, 91; A., 360.88 J . Biol. Chern., 1930, 87, 761; A., 1201.8o Ann. Reports, 1929, 26, 241268 CHIBNALL AND PRYDE :most trustworthy for determining the reducing substances of avianblood, but these filtrates contain in addition to glucose, ergothion-eine and some other unknown substances which reduce the ferri-cyanide reagent. Some 60% of the residual (non-glucose) reducingvalue is not accounted for by ergothioneine.To judge from the number of papers published on the subject,the problem encountered by Gulland and Peters, perhaps in a lessacute form, must be kept in mind in relation to the determinationof the reducing substances of mammalian blood.That glucoseis present as such in blood has been demonstrated by L. B. Winter,s4who has been able to isolate the normal crystalline form of thehexose from blood filtrates. But it cannot be doubted that in thevarious methods used for determining blood sugar, other reducingsubstances in varying amounts are included from time to time inthe glucose figure. A useful critical study of this question inwhich the Shaff er-Hartmann alkaline copper reagent is used,together with a consideration of the effects of different deprotein-ising agents upon the determination of Flood sugar, has beenpublished by S.L. T o m p ~ e t t . ~ ~ The reducing power of glutathionein relation to this problem is dealt with by M. R. Everett,86 andthe effect of acid hydrolysis on the total carbohydrate content ofthe blood is examined by F. Silberstein, F. Rappaport, and M.W a ~ h s t e i n . ~ ~ Papers by J. Roche,88 E. J. Bigwood and A. Wuil-lot,8s and G. Font& and L. Thivolle should also be consulted.The Coagulation of Hcernoglobin and its Reversal.M. L. Anson and A. E. Mirsky91 have brought to light a veryinteresting property of haemoglobin which it probably possesses incommon with other proteins. It has been the accepted view thatwhen a protein is coagulated or denatured the change which it hasundergone is an irreversible one.Protein coagulation proceeds intwo distinct steps. The first, known as denaturation, is a changein the native protein brought about by heat, the action of acid,alcohol, or other agents, which makes the previously soluble proteininsoluble near its isoelectric point. The second step is the pre-cipitation of the insoluble denatured protein. The latter, althoughinsoluble near its isoelectric point, is soluble in acid or alkali. If,therefore, a protein is denatured in a nearly isoelectric solution, a848 58 78 889P1Biochem. J., 1930, 24, 851; A., 1306.Ibid., pp, 1148, 1164; A., 1306.Biochem. Z., 1929, 213, 355; A., 1929, 1477.Bull. SOC. Chim. biol., 1930, 12, 636; A., 1054.Ibid., 1929, 11, 1204; A., 1930, 237.90 Ibid., p. 1212; A., 237.J . Gen. Physiol., 1929,13, 121, 133; 1930,13,469,477; A,, 102,630.86 LOC. citBIOCHEMISTRY. 269visible precipitate results. But if a protein is denatured in acid oralkaline solution, no visible change results until the solution ismade isoelectric; the protein is then precipitated. The secondstep in coagulation, the flocculation of the insoluble protein, is, ashas long been known, reversible, since the flocculated protein mayreadily be redissolved. The first step in coagulation, denaturation,has hitherto not been reversed. When a solution of the coagulumin acid or alkali is brought to the isoelectric point, the protein isagain precipitated ; it is still denatured. Denaturation, therefore,is the important process in the investigation of the reversibility ofcoagulation.Anson and Mirsky have been able to show in the first placethat hzmoglobin, like all typical coagulable proteins, may becompletely denatured, the test of complete denaturation beinginsolubility at the isoelectric point.Denaturation of the nativehemoglobin has been effected in a number of different ways, byheat in the presence of acid, by acid, by urea, and by shaking, andin all cases the results are the same. From preparations of com-pletely denatured horse haemoglobin Anson and Mirsky have pre-pared native carbon monoxide-haemoglobin which is identical withthe same pigment obtained directly from native haemoglobin.‘‘ Reversed ” hemoglobin can be coagulated by heating, and inregard to its colour, absorption bands, gas affinities and otherproperties it is indistinguishable from native hzmoglobin whichhas not been through the denaturation process.By means ofcrystallographic, spectroscopic, and gas-affinity measurements thesoluble native haemoglobin prepared from coagulated horse hzmo-globin cannot be distinguished from native hzmoglobin in general,or from horse hemoglobin in particular. Denatured haemoglobinsof various species cannot be distinguished from one another byspectroscopic and gas-affinity measurements, but, on the otherhand, after reversal of the coagulation the species’ characteristicsonce more become observable. Anson and Mirsky have securedyields of 75 and 80% of the reversed protein, which would seem toremove all possibility of their results being due to the presence of aresidue of native hzmoglobin attached to the main bulk of de-natured protein.It is concluded that protein coagulation ingeneral is probably reversible. In support of this view it is shownthat, by the use of acid acetone, haemoglobin may be rapidly separ-ated into a precipitate of denatured globin and an acetone solutionof haematin. By gradual neutralisation the denatured globin maybe largely converted into a soluble native form which can combinewith haematin to form hemoglobin.It seems not improbable that the phenomenon of denaturatio2 70 CHIBNALL AND PRYDE:and its reversal may have a wide significance in the chemistry ofthe proteins as a whole. I n the living cell the reversible coagulationof proteins a t intersurfaces may play some part in determining theproperties of semipermeable membranes, or in the mechanisms ofmuscle contraction.Hcemocyanin.During the period under review a considerable revival of interestin haemocyanin has occurred and a number of interesting refer-ences to the pigment have appeared. None of the newer investig-ations supports the view that haemocyanin is constituted on linessimilar to haemoglobin, that is to say, there is no evidence of thepresence of a copper-porphyrin in its molecule.J. Roche92 hasshown that it is possible to separate the copper from haemocyaninby adjusting the solution to pH 2.5, by the addition of dilute hydro-chloric acid, followed by dialysis. Such treatment applied t ohaemoglobin transforms it into haematin and globin.No similartransformation is observed in the case of hEmocyanin. Degradedhaemocyanin, as Roche calls the copper-free substance, shows thesame isoelectric point, buffering power, and solubility as naturalhaemocyanin. It is concluded that no prosthetic group is liber-ated by this treatment, and that the presence of such in the haemo-cyanin molecule is problematical. It is thought that the viewtaken by M. Heme 93 in 1901, namely, that hzniocyanin is a copperproteinate, is much nearer the truth than some of the views advancedsince that date. Roche has also shown an interesting differencebetween the haemocyanins of Octopus and Limulus. The pigmentof the former has an isoelectric point (prr 4.8) close to that of the crust-acean pigments examined by E.Stedman and (Mrs.) E. Stedman,9*whereas the isoelectric point of Limulus haenlocyanin is muchhigher (pH 6.2-6.4), a fact which is possibly related to the muchmore archaic morphological characters of the king crab.Conclusions essentially similar to those of Roche have beenreached by J. B. Conant and W. G. Humphrey95 and by A.S ~ h m i t z . ~ ~ The former investigators find the pigment to be aprotein in combination with a complex salt of an unknown amino-acid containing sulphur, which forms highly coloured complexeswith amines, and in this respect functions in a manner similar tothe protoporphyrin of haemoglobin. Schmitz suggests that thepigment consists of a protein combined with a complex copper92 Arch.Physique biol., 1930, 7, 207. 93 2. phyaiol. Chem., 1901, 33, 370.94 Biochem. J., 1927, 21, 533; A., 1927, 689.95 Proc. Nut. Acad. Sci., 1930, 16, 543; A., 1304.96 Natu&8., 1930,18, 798; A., 1304BIOCHEMISTRY. 27 1compound which is of a peptide nature. It should be mentionedthat the methods used by Conant and Humphrey and by Schmitzin degrading haemocyanin were much more drastic than thatemployed by Roche. It is doubtful in view of Roche's resultswhether one can accept their evidence for the existence of a copper-containing prosthetic group of a peptide nature.F. Herder and E. Philippig7 give the following composition ofair-dried crystalline oxyhaemocyanin from Helix pomatia : C, 48.59 ;H, 7-04 ; N, 14-26 ; S, 0.71 ; Cu, 0.232.E. Philippi and F. Hern-ler9* have published a further paper on the action of papain ontheir purified haemocyanin, which confirms the earlier results ofC. Dh6rrB and C. Baumelerg9 regarding the rapid formation ofcrystalline oxyhaemocyanin in the presence of papain and sodiumfluoride. The ease of crystallisation is remarkable in view of theenormous molecular weight of 4,930,000 assigned by T. Svedbergto haemocyanin.Female Sexual (CEstrous-producing) Hormone.During the past two years activity in this field has greatly in-creased and in view of the fact that several workers have isolatedcrystalline products with considerable biological activities a reviewof the present position seems desirable.The presence of an estrous-producing hormone in the urine ofpregnant women was first shown in 1927 by Aschheim and Zondek.Since that date many workers have entered the field and during thepast year several claims have been made to have isolated thehormone in a crystalline form.H. Wieland, W. Straub, and T.Dorfmiiller 2 described the preparation of an active crystallinematerial which melted at about 175" and finally became liquidwith decomposition at 210°, but no claim was made that the sub-stance was pure. A. Butenandt3 prepared an active crystallinesubstance which, from the constancy of its activity after recrystallis-ation and resublimation, he believed to be the hormone itself.The substance melted at 240", with decomposition, and fromanalyses the formula C23H2803 or C24H3203 was ascribed to it.Itwas unsaturated and on account of its behaviour with aqueousalkali it was suggested that the substance was a hydroxy-lactone.A. Butenandt and E. von Ziegner * later raised the melting point to243-245", and Butenandt ti modsed his &st suggested formula to1 Ann. Reports, 1928,25,239.97 2. physiol. Chem., 1930, 191, 23; A., 1461.Compt. rend. SOC. Biol., 1929, 101, 1071.2. physiol. Chem., 1929,186, 97 ; A., 1930, 265.Naturwiss., 1929, 17, 879; A., 1930, 118.2. physhl. Chem., 1930, 138, 1; A., 646.Ber., 1930, 63, [ B ] , 659; A., 633.Ibid., p. 28272 CEIBNALL AND PRYDE :C2,H3,02 and ascribed to the compound a structure closely analogousto that of the bile acids and sterols. Finally Butenandt describednew methods of preparing the hormone and assigned to it theformula CI8H2,O2, with [ a ] , + 156" and a melting point of 250-251".It contains a hydroxyl group, a keto-group, and threedouble Wings. E. Dingemanse, S. E. de Jongh, S. Kober, andE. Laqueur described a substance which appeared to be similar tothat of Butenandt to judge from the melting point and analyticalfigures. E. A. Doisy, C. D. Veler, and S. Thayer * have also pre-pared what they claim to be the crystalline hormone, since theirmaterial possessed a constant activity and melting point after twentyrecrystallisations from several different solvents. These workerslahr ascribed to their substance the formula C,8H,1(OH), [sz'c],although their figures would agree equally well with formuhhaving one less or one more hydrogen atom.The meltingpoint was 243". One double bond is stated to be present and thesubstance is weakly acidic.I n 1929, previous to the publication of the results described inthe foregoing paragraph, G. P. Marrian described the isolationfrom the urine of pregnancy of a crystalline oestrous-producinghormone to which he a t that time, and as a result of preliminaryinvestigations, ascribed the formula CI9H3& OH), or C,,H32( OH),and a melting point of 233-235". Improved methods of isolationand purifkation of the hormone lo eventually yielded a substancewith a melting point of 281" having the constitution C18H2,03. Ithas + 38". The substance has three hydroxyl groups, oneof which is acidic and therefore presumably phenolic in character,and indeed definite reactions for a phenolic group have been obtained.Its activity is .unchanged after numerous recrystallisations.It will be observed that the formula most recently adopted byButenandt differs from Marrian's formula only by H20, and Buten-andt himself suggests that Marrian's substance may be the hydrateof his hormone.The much higher optical rotation of Butenandt'smaterial would tend to support this view, as would also the factsthat only one hydroxyl group is present whilst the remainingoxygen is present in a ketonic or similar grouping. In any caseButenandt's conclusions seem now to be much closer to those ofMarrian than they were some months ago. I n a private com-munication Marrian informs the Reporter that Butenandt has2.physiol. Chem., 1930,191, 127, 140; A., 1480.7 Deut. med. Woch., 1930, 58, 301; A., 1320.* J . Biol. Chem., 1930, 86, 499; 87, 357; A., 821, 1069.0 Biochem. J . , 1929, 23, 1090; A., 1929, 1495.10 Ibid., p. 1233; 1930, 24,435, 1021; A., 254, 821, 1320BIOCHEMISTRY, 273recently isolated, in addition to the active substance C1,H2,02,the substance C1,H2,0, (Marrian’s crystalline substance), and thathe finds the latter to be physiologically active. It would thereforeappear that both these substances are present in the urine of preg-nancy, and that at some stage two hydroxyl groups are insertedin, or lost from, the hormone as it comes from the ovary withoutmaterially affecting the physiological activity.It seems to the Reporter highly probable that all these workersare handling the same or very similar crystalline materials invarying degrees of purity.Owing to variations in the methods ofbiological assay employed by the various workers it is not possibleto make the assay figures a satisfactory basis of comparison betweendifferent preparations. But it may be mentioned that Marrian’spurest material has an activity of 8 x lo6 mouse units per gram.On conversion into the acetate the activity fell to 3.74 x lo6 mouseunits per gram. On the basis of the amount of the original sub-stance present in the acetate, this activity corresponds to 5-37 x lo6mouse units per gram. Thus the conversion of the substance intoits acetate appeared to have decreased its physiological activity toa significant extent.The material regenerated from the acetatepossessed an activity of 7.4 x lo6 mouse units per gram, fromwhich it seems cer$ain that hydrolysis of the acetate yielded theoriginal substance again.The Liver Constituent Curative of Pernicious Anemia.In the Report of two years ago attention was directed to thework of Cohn l1 and his collaborators on the concentration of thesubstance present in liver, which had a specific curative action incases of pernicious anzmia. The opinion was then expressed thatthe properties of the substance suggested those of a salt of a fairlycomplex organic acid. R. West and M. Howe l2 have now describedthe isolation of a crystalline derivative of an acid present in liverand active in pernicious anEmia. They give details of the prepar-ation of an active amorphous material from a concentrated aqueoussolution of commercial liver extract.This material is stronglyacid to litmus and to methyl-red and contains approximately 46.6%of carbon, 6.9% of hydrogen, and 10.6% of nitrogen. Free amino-nitrogen is absent, but after acid hydrolysis one-half of the nitrogenis obtained in that form. A finely crystalline quinine salt of thisacid was obtained by gently warming its solution and addingquinine gradually until the reaction was neutral or slightly alkalineto litmus. Recrystallisation was easy and to this quinine salt isassigned the provisional constitution C20H,,0~2,Cl,Hl,06N2.11 Ann. Reporta, 1928, 25, 263.l2 J , Bid. Chem., 1930, 88, 430274 CHIBNALL AND PRYDE :Physiological tests on the substance after removal of the quinineshowed it to be highly active in producing a reticulocyte responsein cases of pernicious anemia. When the quinine salt was decom-posed with soda, and the quinine removed, a solution was obtainedwhich after hydrolysis contained amino-nitrogen and gave thequalitative reactions of p-hydroxyglutamic acid. This acid wasalso isolated as its silver salt. Later, H. D. Dakin, R. West, andM. Howe l3 identified Z-y-hydroxyproline as a constituent of theoriginal active substance. The latter is therefore regarded as thedipeptide of this acid with p-hydroxyglutamic acid. From thedescription of its properties given in these communications itwould appear to have the constitution :YO*OH YH2-TH*OH(JH*NH-CO*CH CH,1-Thyroxine as a Constituent of the Thyroid Protein.C. R.Harington and W. T. Salter 14 have recorded the successfulisolation of thyroxine from the thyroid gland by means of theaction of enzymes alone. An alkaline sodium chloride extract ofthe gland was digested by successive additions of trypsin at pH 8.5,and after precipitation at p H 5 , it was extracted with acid acetoneand reprecipitated with ether. This precipitate was subjected tofurther tryptic digestion, and then precipitated at pH 5 and redis-solved in water with the aid of the least possible amount of ammonia.Pigmented impurities were removed by boiling with barium hydr-oxide. After precipitation at pR 5 and solution in alkaline 80%alcohol, further impurities were precipitated with acid acetone.The digestion product at this stage was not further acted upon byanimal erepsin or yeast peptidase.The product was dissolved inpyridine, precipitated by dilution with water, dissolved in potassiumcarbonate solution, decomposed with acetic acid, and reprecipitatedas the monosodium salt of thyroxine on cooling after boiling withsodium carbonate. The sodium salt on decomposition with aceticacid yielded Z-thyroxine. Comparative physiological tests on thedigestion product and on pure Z-thyroxine have shown that thereis no reason to presume the existence in the thyroid gland of anactive principle other than thyroxine, or of its existence there in an" activated " form.Thus the isolation of thyroxine through the13 Proc. SOC. Exp. Biol. Med., 1930, 28, 2.14 Biochem. J., 1930, 24, 456; A., 820BIOCHEMISTRY. 275unaided action of a proteolytic enzyme supplies the final proof thatthe compound is present in the gland in peptide combination as aconstituent of thyreoglobulin. Moreover the optical rotation ofZ-thyroxine isolated by the enzymic procedure proves the com-pleteness of the resolution of dl-thyroxine already described byHarington.Acetylcholine from a n Animal Source.A matter of great physiological interest is the isolation of acetyl-choline from the spleen of the ox and the horse by H. H. Dale andH. W. Dudley.16 This is the first record of the natural occurrenceof this substance in the animal body, although it has been widelyemployed in physiological experimentation.It was prepared arti-ficially by Baeyer in 1867 and there are two later records of itsisolation from plant sources. Its physiological interest lies in thecorrelation of its action with that of the parasympathetic nervoussystem just as adrenaline simulates the action of the sympatheticdivision of the autonomic nervous system. Dale and Dudley, afterdiscussing these physiological problems, say : " But there has beena natural and proper reluctance to assume, in default of chemicalevidence, that the chemical agent concerned in these effects, or inthe humoral transmission of vagus l7 action, was a substanceknown, hitherto, only as a synthetic curiosity, or as an occmionalconstituent of certain plant extracts.Many things could beexplained if the liberation of acetylcholine could be postulated ;but the minuteness of the qua,ntities required to produce the effectsin question, and the extreme instability of the substance, whileenhancing its theoretical fitness for the suggested functions, pre-cluded any hope of its chemical identification at the sites of itspossible liberation. . . . Its definite isolation from one organ hasso far altered the position that, when an extract from, or a fluidin contact with the cells of, an animal organ can be shown to con-tain a principle having the actions, and the peculiar instability, ofacetylcholine, it will be reasonable in future to assume the identific-ation." H.W. Dudley l8 has published a separate description ofthe methods used in the difficult problem of separating acetyl-choline from choline by means of their chloroplatinates. A furtherstudy by H. H. Dale and J. H. Gaddum l9 deals with the behaviourof denervated voluntary muscles in relation to the actions of thel6 Ann. Reports, 1928, 25, 261.16 J. Phyaiol., 1929, 68, 97; A., 1930, 104.1 7 The vagus nerve belongs to the parasympathetic branch of the autonomic18 Biochem. J., 1929, 23, 1064; A., 1929, 1479.Is J. Physiol., 1930, 70, 109.system.-J. P276 CHIBNALL AND PRYDE :parasympathetic system and of acetylcholine. In this importantpaper much evidence is brought forward in support of the view thatthe vaso-dilator effects of parasympathetic nerves, and of sensoryfibres stimulated antidromically, and the contractures of denervatedmuscles accompanying these actions, are due to the peripheralliberation of acetylcholine.The Vitamins.Carotin and Vitamin-A.-During the past year the main interestof investigators has centred on the problem of t'he relationship ofthe hydrocarbon carotin to vitamin-A.Earlier work in this fieldwas reviewed in the Report of lamst year.20There is now general agreement that carotin of the highestpurity so far attained, and of whatever origin, possesses intensevitamin-A activity. T. Moore21 has, for instance, shown thatcarotin prepared from the unsaponifiable matter of red palm oilwas active in doses of 0.01 mg. per day when fed to rats.It hasbecome equally clear that carotin is not itself vitamin-A. W. L.Dulidre, R. A. Morton, and J. C. Drummond 22 have described acareful colorimetric and spectroscopic differentiation of carotinfrom the vitamin-A of cod-liver oil. They found that the bluecolours produced in the antimony trichloride reaction were ofslightly different shade, that of carotin being characterised by anabsorption band at 590pp, and that of vitamin-A by a band a t608-612 pp : in regard to the ultra-violet absorption spectravitamin-A showed a band a t 320-330 pp which was absent in thecase of carotin. Moreover, pure carotin, which is deeply coloured,possesses an activity not greatly exceeding that of the best cod-liveroil concentrates, which are a t most of a pale orange colour.Theinevitable conclusion seems to be that carotin is transformed intovitamin-A in vivo. Direct evidence of this transformation hasbeen obtained by T. Moore23 and by N. S. Capper.24 Moore hasshown that the liver oils of rats suffering from vitamin-A deficiencyinvariably gave negative results when tested with the antimonytrichloride reagent. After such rats had been cured by the admini-stration of large doses of carotin, it was found that traces of yellowpigment appeared in the liver oil. At least 99% of the chromogenpresent was vitamin-A, as characterised by (a) the absence of suchintense yellow pigmentation as must have accompanied the storageof carotin as such; (b) an intensely positive antimony trichloride2o Ann.Reports, 1929, 26, 245.21 Biochem. J . , 1929, 23, 1267; A., 1930, 255.22 J . SOC. Chem. Id., 1929, 48, 518.23 Biochem. J . , 1930, 24, 692; A., 962.24 Ibid., pp. 453, 980; A., 822, 1321BIOCHEMISTRY. 277reaction showing a marked band at 610-630 pp; (c) the appear-ance of an absorption band in the untreated oil at 328 pp; (d) in-tense biological activity. Capper has shown that the band at320-330 pp is absent from trhe liver oils of rats suffering fromdepletion of vitamin-A, but is present in the liver oils of similarrats subsequently cured by massive doses of carotin. Since thisband is absent from the absorption spectrum of purified carotin,it is deduced that the substance which is responsible for the pres-ence of this band in the spectrum of the liver oils of carotin-treatedrats has been synthesised in, vivo from the carotin.In view of the foregoing results and of the importance of butteras a source of vitamin-a, R.A. Morton and I. M. Heilbron 25 haveinvestigated the presence of carotin and of the vitamin in this fat.Both were found to be present and to be capable of spectroscopicdetermination with some degree of accuracy. These workers sup-port Moore's view regarding the conversion of carotin into vitamin-Ain vivo. Further evidence bearing on this relationship has beenpublished by H. von Euler, lr. Demole, P. Karrer, and 0. Walker,26who have determined the carotin and xanthophyll contents of theether-soluble unsaponifiable matter of the extractives of the dryleaves of various plants, of the flowers of CnZthcc paZustris,.and ofmaize grains.In all cases the vitamin activity runs parallel withthe carotin content. An interesting result is that of M. Javillierand L. Emerique?' who found that a preparation of carotin fromspinach which had been kept in an atmosphere of hydrogen andexposed to feeble diffused light for 40 years exhibited the physio-logical properties of vitamin-A. The same workers 28 record thepurification of a specimen of carotin of melting point 172-173" toyield one of melting point 184-185". This was achieved by fivesuccessive purifications by dissolution in carbon disulphide, slowaddition of the solution to boiling methyl alcohol, removal of thecarbon disulphide, and filtration of the residual liquid, all oper-ations being carried out in an atmosphere of nitrogen. The purifiedproduct retained its vitamin activity.Vita;min-D.-The anti-rachitic vitamin continues to elude capture,but if anything the gap between the fugitive vitamin and its pursuersis narrowing.F. A. Askew, R. B. Bourdillon, H. M. Bruce, R. G. C.Jenkins, and T. A. Webster 29 have published a detailed study ofthe distillation of vitamin-l), or rather of the resins obtained by25 Biochem. J., 1930, 24, 870; A., 1321.26 Helv. Chim. Acta, 1930, 13, 1078; A., 1624.27 Compt. rend., 1930,190, 665; A., 647.28 &d., 1930, 191, 226; A., 1221.** Proc. Roy. Soc., 1930, [B], 107, 76; A, 1481278 CHIBNALL AND PRYDE:the removal of unchanged sterol from irradiated ergosterol. Aspecially designed still and a very high vacuum were employed.On three occasions the redistillation of one of the more volatilefractions yielded a crystalline product.Recrystallisation waspossible and the material was obtained as rather thick needlesshowing conspicuous double refraction in polarised light. Themelting point was 113-115". In each case the crystals have shownvery high anti-rachitic activity. The authors point out that, ifthere is only one substance possessing intense anti-rachitic activity,that is, only one vitamin-D, it is not very probable that thesecrystals are this substance. Resinous mixtures of approximatelythe same anti-rachitic activity as the crystals have frequently beenobtained, although their low melting points and varying absorptionspectra suggested that they were mixtures of a number of sub-stances. The interest of this problem justifies a detailed referenceto the four possibilities advanced by the authors.(1) The crystals may be an inactive substance contaminated bytraces of an intensely active oil deposited on their surfaces.This is not thought to be probable, since the cleanestspecimen obtained showed the highest activity and appearedfree from oil.If an oil film was the source of the activity,it must have had an activity of a higher order than anyyet observed.(2) The crystals may be a mixture in any proportion of two ormore substances of sufficiently similar molecular dimen-sions to form homogeneous crystals, only one of thembeing vitamin-D.This is regarded as possible in view ofthe frequent occurrence of such mixed crystals among thesterols.(3) The crystals may be a loose compound of an active and aninactive substance.(4) There may be a number of radiation products of ergosterolall possessing high but unequal anti-rachitic activities,that is, a number of compounds any one of which couldbe called vitamin-D, but would cause only a fraction ofthe total activity of the ordinary irradiation products ofergosterol. This is regarded as not improbable.It is observed that during the heating in a vacuum there isformed a new substance with intense absorption at 290 pp. Thissubstance has no anti-rachitic activity, but its appearance is associ-ated with the disappearance of the vitamin.It cannot be regardedas a simple product of vitamin destruction, since its productionbears no direct relation to the vitamin content shown, beforeThese are BfOCHEMIS!I'RY. 279distillation, by the irradiation products from which it is formed.The two conditions which favour its formation and the concurrentdisappearance of the vitamin are previous protection of the irradi-ation product from exposure to air, and the exclusion of shortwave-lengths during the original irradiation. It is tentativelysuggested, in explanation of these facts, that one of the initialirradiation products of ergosterol is an unstable substance withlow absorption and no anti-rachitic activity, that this substance isvery readily destroyed by absorption of oxygen, or by radiation ofshort wave-lengths, but that, if not previously destroyed, it isconverted by heat into the substance absorbing light at 2 9 0 ~ ~with an associated destruction of part of the vitamin present.The same authors in another paper 30 report the results of furtherirradiation of the radiation products of ergosterol. When thesecond irradiation was carried out with short rays (210-280~~)acting on the substances formed by a first irradiation with '' long "rays (longer than 280 pp), there resulted a large increase in absorp-tion a t 280yy and a decrease in anti-rachitic potency.On re-irradiation with long rays, the absorption a t 280py was slightlydecreased, whilst the activity was unchanged. The substance withhigh absorption at 2 8 0 ~ ~ can be formed by the action of shortwaves on some product of a previous action of long waves onergosterol. The results show that the product with high absorp-tion a t 280 py is not vitamin-D as previously supposed,3l and it isnow suggested that the initial effect of long-wave radiation onergosterol is the simultaneous production of at least two substances,only one of which is vitamin-D.In the Report of last year reference was made to the conditionof hypervitaminosis 32 induced by the administration of excessivedoses of irradiated ergosterol or other source of vitamin-D.Duringthe past year numerous investigations, which need not be detailedhere, have been devoted to EL consideration of this problem andmuch valuable information has been obtained.But in view of theforegoing discussion concerning the products of irradiation ofergosterol, a communication by F. Holtz and E. Schreiber 33 issignificant. It is claimed that the hypervitaminosis effects, namely,calcium deposition, hypercalcaemia, hyperphosphataemia, and circul-atory deficiency, are produced by a toxic substance, which they callthe " calcinosis " factor, and not by vitamin-D itself. The toxicfactor and the vitamin produced under various conditions ofirradiation are stated to be closely proportional. It is furtherao Proc. Roy. SOC., 1930, [B], 107, 91; A., 1481.31 Ann. Reports, 19W, 28, 249.33 2. physiol. Chern., 1930, 191, 1; A., 1481.82 Ibid., p. 251280 CHIBNALL AND PRYDE :claimed that the calcinosis factor may be isolated and its effectsstudied by heating the irradiated ergosterol to 160°, or by reductionwith sodium in alcohol, whereby the anti-rachitic vitamin alone isdestroyed.The B Vitamin Group.-Since the nature of the B vitamin com-plex was last dealt with in these Reports 34 the problem has under-gone a further development in complexity. In 1928 R.R. Williamsand R. W. Waterman 35 submitted evidence that polyneuriticpigeons, made so either by an exclusive diet of polished rice, or bya synthetic diet complete in all respects save for the vitamin-Bcomplex, require for full weight restoration or maintenance a factorwhich is distinct in properties and distribution from the anti-neuritic vitamin-B,, or the anti-pellagra vitamin-B,. In 1929V. Reader 36 presented evidence for the division of the B vitamincomplex into three components, all necessary for the nutrition ofthe rat. It was shown that two of these were destroyed by auto-claving yeast extract a t p H 9 for one hour at 120". It was later 37found possible to concentrate two of these components, and it wasthen shown that the third must still be added to the diet of rats toenable these animals to grow to maximum adult size. The Williams-Waterman vitamin and the Reader vitamin are not the same,although they were both at first called vitamin-B, by their respectivediscoverers. The matter has now been amicably adjusted and theterm B, is applied to the first-mentioned vitamin, and B, to thesecond. The present position may perhaps best be summarised inthe following table :Required bygrowing adultVitamin. rat. pigeon. Properties. + + Alkali-labile, the original anti-neuritic vitaminof Eijkmann, called torulin by Peters. + - Alkali-stable, the anti-pellagra vitamin of Gold-berger, also called the anti-dermatitisvitamin.- + Thermo-labile, the Williams-Waterman pigeonfactor.B4 3. + Alkali-labile, the rat factor of Reader.B,B'2*3W. H. Eddy, S. Gurin, and J. Keresztesy38 have extended theoriginal work of Williams and Waterman and find that yeast, wholegrains, and malt are good sources of vitamin-B,, but while maltextract often retains a good concentration of B,, its method ofmanufacture practically eliminates B,. Malt extracts made at34 Ann. Reports, 1928, 25, 269.36 Biochem. J., 1929, 23, 689; A., 1929, 1203.57 Ibid., 1930, 24, 77; A., 380.3B J. Biol. Chem., 1930, 87, 729; A., 1222.35 Ibid., p. 266'3BIOCHEMISTRY. 281temperatures as low as 60" atre practically devoid of B,, althoughthey are still very effective as sources of B,. Beef and beef liverare fair sources of B, and distinctly superior to milk, orange- andtomato-juice, spinach, and potato-juice or cane molasses in thisrespect. Vitamin-B, is much more heat-labile than B,, and, if itis submitted to alkali treatment before drying, temperatures as lowas 20" will markedly reduce the content of this vitamin in yeast.Miss Reader obtains vitamin-B,, the second alkali-labile rat factor,from the mercuric sulphate precipitate in the Kinnersley andPeters process 39 for vitamin-B,. In this precipitate some 75% ofthe original B4 is recovered. It is suggested that the vitamin formsan insoluble mercury salt, or a double salt with mercuric sulphate.In regard to the B vitamin components of longer standing thanthose just discussed, B. C. Guha and J. C. Drummond,4° and B. T.Narayanan and J. C. Drummond41 describe new methods of con-centrating B, and B2 respecbively. R. R. Williams, R. E. Water-man, and s. Gurin 42 have applied the process of Jansen and Donathfor B, to brewers' yeast, but have failed to isolate highly activematerial. On applying the method as did the original authors torice polishings, general confirmation of the Dutch results wasobtained, although the yield of active material was much lowerand crystals could not be obtained. The authors' highly purifiedbut amorphous preparations behave in all respects like the crystallinesubstance of Jansen and Donath. These results are thereforesimilar to those obtained by Kinnersley and Peters in 1927.43 Itmay be mentioned that B. C. P. Jansen4* has published furtherimprovements in his methods of fractionating the extracts of ricepolishings.Bios.-In a paper published by B. T. Narayanan45 the non-identity of " bios " with vitamin-Bi is established, and J. G. Daviesand J. Golding46 have made a similar finding with regard tovitamin-&. A. M. Copping 47 has shown that the need for " bios "depends on the type of yeast and on the nature of the culturemedium. The need is probably related to the fermentative activityof the yeast. Some of the highly cultivated brewers' yeasts willnot grow in a purified glucose-salt medium without the additionof small amounts of extracts containing an organic " bios." Nara-yanan describes a method of fractionation which provides con-39 Biochem. J., 1927, 21, 778.40 Ibid., 1929, 23, 880; A., 1929, 1496.42 J . Biol. Chem., 1930, 87, 55!); A., 1222.43 Harben Lectures, J . State &Xed., 1930, 38, 38.44 Rec. trav. chim., 1929, 48, 984.46 Ibid., p. 1803; A., 1479.4 1 Ibid., 1930, 24, 19; A., 380.45 Biochem. J., 1930, 24, 6; A., 375.47 Ibid., 1929, 23, 1050; A., 1929, 1491282 CHIBNAJLL AND PRYDE : BIOCHEMISTRY.centrates producing marked stimulation of yeast growth in dosesof the order 0.01 mg. per C.C. of an artificial sugar-salt medium. Thefinal concentrate appears to consist largely of relatively simplenitrogenous substances and contains no phosphorus. No evidencein support of the complex nature of " bios " was obtained in thecourse of these investigations, nor is there any indication thatinositol is an essential unit of " bios."A. C. CHIBNALL.JOHN PRYDE

ISSN:0365-6217    

DOI:10.1039/AR9302700229

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

GEOCHEMISTRY,THE year’s literature has reflected a substantial increase in interestin almost all branches of geochemistry. There are considerableimprovements in the study of opaque ores by reflected light, whichseem destined to stimulate interest in these substances and toremedy the somewhat one-sided development of the science infavour of the non-opaque minerals. X-Ray researches on most ofthe chief mineral groups have already been published, and thereis a consequent slackening in the description of entirely new struc-tures; many of the postulates on which these have been based arenow receiving more rigorous examination, an outstanding featurebeing the better investigation of solid solutions and a clearer realis-ation of the difficulties that arise from the fact that material in solidsolution cannot be detected by the ordinary methods of X-rayanalysis.Mineral synthesis includes investigations in groups suchas the sulphides and iron ores, beside the extension of work on theoxide systems. In the description of mineral species many newnames will be found, and a welcome feature is the greater complete-ness of the descriptions and analyses; special mention may bemade of the investigation of phosphate minerals which forms partof research work assisted by Harvard University, and published inthe American Mineralogist. Many chemists have obtained materialsfor research from the well-known “ Ward’s Natural Science Estab-lishment,” now connected with Rochester University ; in the autumnof 1930 this valuable mineral collection was partly destroyed byfire, but fortunately much of the stock has been saved so that theinterruption in supplies may not be so serious as was at first feared.Many mineral descriptions will be mentioned in the following pages ;attention may perhaps be directed to the descriptions of the opaquesulphides, phosphates, felspars, and clays, in which considerableadvances have taken place.It has been impossible to include areview of all branches of the subject ; for many important researcheson the properties of minerals, rock analyses, etc., reference must bemade to the “ Abstracts ” or to the literature.M inerqrap hy .This name seems destined to come into general use to designatethe study of minerals under the microscope by reflected light.Although the practical development of this subject has taken placemainly during the past few years, it is already clear that in it2% HALLIMOND :own sphere the subject will rival in importance metallography andthe study of transparent rock sections.Probably the mostimportant line of development in mineralogy a t the present time,its possibilities may already be gathered in some degree from theexcellent photomicrographs to be found, for example, in the currentvolume of Economic Geology. Methods of examination by etching,by polarised light in the manner initiated by J. Konigsberger, andby hardness and other tests, are rapidly being reduced to standardlaboratory practice, for which text-books are already available.Metallographers have long been accustomed to study and even tobuild up a phase-rule diagram from the microstructure of the corre-sponding alloys, and similar, though generally less adequate,attempts have been made at the more difficult task of interpretingthe microstructure of rocks in terms of the chemical data available.In the same way the present method has greatly helped in theinvestigation of the chemical history of sulphide and oxide ore-bodies.Important among these are the sulphide ores of Cobalt,Ontario, which have been studied by E. Thompson; etchingmethods are developed in detail for the nine chief arsenical minerals,and ore from the several mines is examined with special referenceto the relation between the composition and the distance from adiabase sill which is regarded as the source of the mineralisation.A.M. Bateman contributes an examination of the copper ores ofRhodesia. These are bedded sandstone or clay, with minutedisseminated grains of chalcocite, bornite, or chalcopyrite, andlying near the base of the Roan Series; oxidation is widespreadnear the surface. All the rocks show signs of heat alteration, pos-sibly by hot solutions carrying the ores. Linnaeite (Co,S,) hasbeen found in several mines; it contains innumerable minuteveinlets of other sulphides-an instance of the importance ofexamining opaque minerals by the present methods before inter-preting their analyses. Chalcopyrite occurs alone or in intergrowthswith bornite, which exhibits an anomalous anisotropic form.Chalcocite is the most important mineral; it exists in two forms,that originating above 91" being cubic; detailed study of the inter-growths suggests that the structures are of isometric form and thatmuch of the ore was deposited by hot solutions, contrary to thegeneral opinion that this ore is " supergene."H.Borchert 3 describes with many photomicrographs the etching,chemical characteristics, and association of the tellurides, for whichit is suggested that the transition point of hessite a t 150" wouldafford a " geologic thermometer."Econ. Beol., 1930, 25, 470. a Ibid., p. 366.a Jahrb. Min., BeiLBd., 1930, [A], 61, 101GEOCHEMISTRY. 285Contributions to theory and methods include an account of thediamond saw, by J. W.Vander~ilt,~ and a description of specialmethods for preparing " thinned " polished sections for examinationby either method of ill~mination.~ Accurate measurement of thereflecting power plays an important part in the identification of oreminerals; H. Frick describes the use of a reflexion photometerocular ; this instrument permits a comparison of the reflected lightwith the intensity of the incident beam, part of which is deviatedthrough prisms to the ocular. The general problem of ascertainingthe crystallographic directions in a surface under reflected light isdiscussed by K. Chudoba.7 In the case of many opaque ores tobe mentioned below, the description is accompanied by an investig-ation by mineragraphic methods, which may now be regarded asessential in all but the simplest cases.Xynthesis and Decomposition.Among the oxide systems that for wollastonite-anorthite-pyroxenehas been determined by L.Koch.8 Quickly cooled melts werestudied optically ; the resulting triangular diagram is of fairlysimple character, complicated by the separation of the two formsof CaSiO, and of the compound 5Ca0,2Mg0,6Si02 in a narrowfield. This system is of great technical importance for blast-furnaceand similar slags, to which reference is made. N. L..Bowen, J. F.Schairer, and H. W. V. Willems9 have investigated the ternarysystem Na,SiO,-Fe,O,-SiO,, by the method of quenching. Acmite,one of the three ternary compounds that crystallise, decomposeson melting, yielding hzmatite; the sinking of these heavy crystalswould yield a great variety of residual melts according to the extentof the differentiation.The lowest eutectic is rich in silica andcrystallises below 800", so that quartz is formed directly from themelt, even in the absence of mineralisers.For the study of ores much interest centres in the sulphide reac-tions, and a considerable body of research on that subject is nowin progress. Sulphide replacement has been studied experimentallyby J. C. Ray.lo Bornite forms finely divided graphic structureswith chalcocite, and these can be " dispersed " to a uniform textureby heating to 150" in balsam, while with steam this temperature wasbrought down to 100". Vessels of Pyrex glass were next used atloo", and by the introduction of reagents a number of metasomaticreactions were accomplished ; the resulting structures are illustratedby photographs in reflected light.J. D.H. Donnay, {bid., p. 270.Centr. Min., 1930, [A], 14.Econ. Geol., 1930, 25, 222.Jahrb. Min., Bed.-Bd., 1930, [ A ] , 61, 31.* Jahrb. Min., Bei1.-Bd., 1930, [A], 61, 277.LI Amer. J . Sci., 1930, [v], 20, 406. lo Econ. cfeol., 1930, 25, 433286 HBUIMOND :An outstanding problem is that of the origin of the siliceous ironores of the Lake Superior region. In a valuable research, J. W.Gruner l1 shows that silica is soluble in hot distilled water to adegree not hitherto realised. Various forms of silica were heatedwith water in gold-lined bombs; at 300”, the amount dissolvedreached about 1000 parts per million, greatly in excess of the valueat 200”.Silicates did not yield so strong a solution, possiblybecause of the presence of the metal ions, Oxidised Lake Superiorores are now known to exist at depths of several thousand feet, andGruner suggests that the oxidation is due to thermal waters andnot, as hitherto supposed, to atmospheric waters. This view issupported by detailed tests on the oxidation of ferrous minerals,which takes place readily in a current of steam at 200”. Magnetiteis not oxidised so rapidly, and in some bomb experiments magnekitewas formed by the limited oxidation of siderite. The second partof the paper contains a description of the principal deposits inthe Lake Superior region; their formation is attributed to hydro-thermal reactions due to the injection of enormous basic magmasunder pre-existing iron formations.Corundum and carborundum are prepared for use as abrasives;their synthesis has been described by V.L. Eardley Wilmot.12Artificial periclase is also prepared commercially and is a valuable,though expensive, insulating material. Silica clinkers, formedduring forest fires, have sometimes been regarded as meteorites;D. T. Englis and W. N. Day l3 have analysed a variety of sampleswhich disprove this mode of origin. F. Machatschki l4 has studied“synthetic domeykite,” which appears to be a mixture of twoarsenides that yield true synthetic domeykite after melting ;algodonite and whitneyite l5 yield on fusion Cu3As and metalliccopper.Great interest attaches to the alterations produced in mineralsby heating or chemical treatment. H.Haraldsen l6 describes thechanges produced in talc on heating. 0. Tamm l7 has shown thaton prolonged grinding felspar is attacked by water, yielding analkaline solution while the particles become hydrated.Publications from the Geophysical Laboratory a t Washington l8comprise work on the oxide systems including leucite-diopside,l1 Econ. Cfeol., 1930, 25, 697, 837.12 Canada Dept. of Mines, “ Abrasives,” Pt. IV, Ottawa, 1929.l3 Science, 1929, 69, 605; A., 1929, 1418.l5 Centr. Min., 1929, [A], 371; Chem. Zentr., 1930, i, 957; A., 1017.16 Jahrb. Min., Bed.-Bd., 1930, [A], 81, 139.1 7 Chem. Erde, 1930, 4, 420; A., 316.*4 Centr. Min., 1930, [ A ] , 19.Full references to these papers are included in the postcard lists, Nos.50-53, circulated by the Laboratory during the yearGEOCHEMISTRY.287acmi t e , potassium met asilic ate, the cris t obalite liquidus, andNa20-Si0,. Vulcanicity is represented by studies on the gasesevolved in the Valley of 10,000 Smokes, Katmai, and on the CentralAfrican volcanoes. Several inorganic systems have been examinedincluding the polymorphous forms of sodium sulphate and potassiumnitrate, the ferrites of magnesium, zinc, and cadmium, and thebehaviour of nitrogen pentoxide at low pressures. Further progresshas been made in determining the elasticity of rocks and minerals lYand the physical properties of silica, and thermodynamic studiesbearing on geochemistry include work on the solutions water-ammonia and an extensive discussion of the equations governingmulticomponent systems.Two papers deal with petrology, onpacificite and the St. Pauls Rocks, and one with the Mid-Atlanticridge. Corresponding work during the preceding year is given inabstract in the Annual Report of the Director 2o for 1929.X-Rays and Chemical Constitution.For the geochemist, the silicates possess an outstanding interest,and the year has been distinguished by an unusual number of papersdealing with the chemical formulation of the silicates in the lightof X-ray research. The complete novelty and importance of theX-ray method of crystal measurement led temporarily to a quiteabnormal output of descriptive work; with the result that, forthe silicates in particular, the general examination of the structuresis now approaching completion. Valuable summaries by W.L.Bragg of this work on the silicates were mentioned in last year’sReport, and a further very complete account by the same authorhas appeared during the current year.21 This summary is of specialinterest on account of the light it sheds upon the value of the proofsoffered for the proposed silicate structures. The brief indicationsgiven make it quite clear that some of the more complex silicateshave been interpreted by means of principles which are not uniformand possess a rather alarming degree of elasticity. Thus for silliman-ite we learn that “ the substitution of aluminium for silicon willnot affect the X-ray diffraction,” and that “ the removal of oneatom of oxygen in forty appears to be tolerated without spoilingthe structural scheme ” ; in Taylor’s solution for analcite “ sixteensodium atoms must be distributed between twenty-four positionsin the unit cell.” In ultramarine, on the other hand, Jaeger has asurplus of sodium atoms, and these are disposed of by assigning themto “ wandering ” positions in the unit cell.Attention ha+s alreadyl@ Proc. Nat. Acad. Sci., 1929, 15, 713.2o Came& Inst. Wash., Year Book, No. 28, 1929, p. 67.a1 2. Kcist., 1930, 74, 237288 HALLIMOND :been drawn in previous reports to certain inconsistencies betweenthe proposed structures and the actual chemical composition of thesubstances concerned; a closer agreement is much to be desired.Future work may be expected to deal to an increasing degree withthe more difficult and debatable aspects of the subject.It wouldlie outside the scope of the present report to give details of thehighly complex structures themselves ; claims have been madethat the chemical properties of a substance can be predicted fromthe form of the space-lattice, but present achievements in thisdirection can hardly be said to have practical importance for thechemist, who will still find it necessary to determine melting pointsand solubilities by the usual methods. One aspect of the subject,however, seems likely to receive much attention from geochemists inthe immediate future; this is the question how far X-ray data canbe used to ascertain the true chemical formula of the silicates.Formulation of the Silicates.In complexity and numbers, the silicates as a class challengecomparison with the organic compounds, and many attempts havebeen made to devise corresponding chemical formule.On the intro-duction of X-ray analysis, a curious reaction set in against the useof formula? of any kind, for it was discovered that the atomicspacings showed in general no demarcation between atoms thatmight be expected to belong to neighbouring molecules. Studentsof organic chemistry had, it is true, been warned of the danger ofattributing any special physical significance to the “ bonds ” of astructural formula, and it was well known that some constitutiveproperties, such as the spectrum of the uranyl group, were presentequally in the crystalline state.Yet the anticipation that chemical“ bonds ” would be evidenced by some physical union between theatoms was so strong that attempts at formulation were very generallyabandoned; P. Groth himself was led to announce “ it is now nomore a question of the chemical molecule.” Of late years thetendency has been to resume the search for a chemical theory ofthe silicates. The absence of molecular demarcation is now knownto be very general in crystals even of the most neutral chemicalcharacter, in which there is every reason to think the atoms arechemically combined : it is difficult, for example, to believe thatthe molecules of a high explosive undergo any serious disturbanceduring crystallisation.Characteristic groups of atoms of the kindto be expected from the chemical formula have now been recognisedboth in organic compounds and in the silicates: the crystallinestructure in both classes of compound suggests that atoms combinedtogether must remain in association, but are capable of a limiteGEOCHEMISTRY. 289free movement around one another so as to assume stable sym-metrical positions in a close-packed space-lattice. The chemicalmolecules might be regarded, in a crude analogy, as readilyflexible, but riot usually subject to decomposition on entering aspace lattice.In considering the very interesting formule proposed by Machat-schki and others,Z2 it may be well to note briefly a somewhat mis-leading tendency in present-day nomenclature.The properties ofthe space-lattice have been explained in terms of many new concepts,based, of course, upon the X-ray properties of the crystal. Therehas been, however, a seeming reluctance to introduce correspondingnew terms; enthusiasm for the application of X-ray methods tochemical problems haa led those concerned to apply old-establishedchemical terms, such as “ valency,” “ ion,” “ stereochemistry,”and “formula,” in a sense quite outside their established use inchemistry. Pauling, for example, has introduced the term valencyto designate a vague and often fractional atomic property which isheld to govern the grouping of atoms in the space-lattice. Again,it has been held that the atoms in a space-lattice are in the “ ionised ”state; the term “ ion ” has consequently been quite commonlyused even in cases where the question of ionisation is not underdiscussion, and where the less debatable term “ atom ” would moreaccurately represent the concept involved.The idea of ionisationin crystals seemed at first to derive support from a well-knownestimate of the size of oxygen, due to Wasastjerna. That authorextrapolated the atomic volunies for a salt in solution so as to obtainan estimate of the volumes of the atoms after crystallisation. Inaccordance with the theories current a t the time, he represented theatoms as spheres and calculated the corresponding ‘‘ ionic ” radiifor chlorine, etc. This estimate has since been used as a basis forthe calculation of many “ ionic radii,” and P.Niggli, in the intro-duction to his latest work on the properties of binary compounds,has summarised the current position as follows : 23r‘ Now experiment shows that radii so calculated are in no wayconstant; many of the results vary according to the substancechosen for starting the calcuhtion. Again, it must not be assumedthat the practice of dividing the interatomic distance into atomicdomains is advantageous for exhibiting the relation between thecrystalline state and that of free ions. The discrepancies between2a These discussions have appeared chiefly in the pages of the Zeitschriftfur Kristdlographie, 1930,73-75, and of the Centralblatt fur Mineralogie, Abt.A, 1930. Formulae have been advanced for the contents of the unit cell in anumber of the most complex minerals ; for details, reference should be made tothese volumes.23 2.Krist., 1930, 74, 375 (somewhat condensed in translation).REP.-VOL. XXVTI. 290 HALLIMOND :calculated and observed interatomic distance, which lead to incon-stancy of the radii, may be ascribed to polarisation, deformation,contrapolarisation, structure-incommensurability, etc. ; but it isclear, to anyone who calculates the radii by way of some otherhypothesis, how much all these concepts depend upon basic postul-ates whose arbitrary nature cannot be evaded.‘‘ The consistent and comprehensive system [of atomic radii],developed by L. Pauling, H. Grimm, and especially V. M. Gold-Schmidt, covers a wide range of phenomena in crystal structure.Anyone who has reconciled himself to the fundamental postulatesmay usefully employ the system for crystallo-chemical problems ;but it must be clearly understood that the regular relationships sodescribed are in themselves no evidence for the correctness of thehypothesis.I n fact it is possible to discover the same regularrelationships, and even more extensive ones, without postulatingthis division into atomic radii, which is inevitably of an arbitrarycharacter.Niggli then discusses the relations between interatomic spacingand the nature of the elements present ; like many other properties,the spacing varies periodically with the atomic weight, and relation-ships of a general character can be traced. For this subject heemploys the name stereochemistry, but in a sense very differentlindeed from that in which the word is used by organic chemists.Lastly, to return to the subject of the present note, the wordformula * has been used to designate the contents of the smallestrepeated unit in the space-lattice.Such a group of atoms can berepresented by symbols like an ordinary chemical formula, indeedin many simple substances the two are identical. But in substanceswith more complex chemistry the two no. longer stand in anynecessary relationship. It will be convenient, in the present dis-cussion, to use the terms “ physical formula ” for the above unitgroup and “ chemical formula ” for the symbols that summarisethe composition and reactions of the compound in question.Thedifference between the two kinds of formula has given rise to muchconfusion because so many physical formulae are written withsubstitutions, like (Ca,Na), that violate the rules of valency governingthe construction of a chemical formula.The importance of the physical formula lies in the fact that it isthis, and not necessarily the chemical formula, that is obtainedwhen the structure is solved by X-ray methods. If all the pointsof a given kind in the space lattice were occupied by like atoms,the relation to the chemical formula would be simpler: the dis-crepancy arises chiefly from the fact, now well established, that* Machatschki uses the term crystallo-chemical formula.It can be done in a second way.GEOCHEMISTRY. 291atoms of similar volume may “ proxy ” for one another in thelattice; for instance, sodium may occupy the place of a calciumatom.This kind of substitution is represented in the physicalformula by the group (Na,Ca) in the same way as an isomorphousreplacement in a, chemical formula, but the two must be clearlydistinguished.Substitution over the full range implied in the physical formulawould obviously yield a number of compositions which are knownto have no stable existence : the fact is that only those physicalsubstitutions are possible in which the resulting difference inchemical valency is compensated by a change in the composition ofthe rest of the crystal. The nature of this compensation dependson the chemistry of the compound, and the physical formula mayshed little or no light on the problem.The SpineZs.-The serious limitations of the physical formula arewell illustrated by the case of the spinels, reviewed in a very interest-ing paper by F.Ma~hatschki.~~ A typical spinel has the formula(Mg,Fe)O,Al,O,. Now titaniferous spinels are known, in which achemical molecure, probably RO,TiO,, enters in solid solution ;X-ray analysis shows that the titanium occupies the place ofalum*ium, so that Machatschki writes the physical formula of thespinel group so far defined as Y Y’, (O,F),, where Y represents atomsMg,Fe,Zn, etc., and Y’ is Al,Fe,Cr,Ti, etc. But this is not all,for there are yet other spinels with a wider range of composition :a series of synthetic crystals has been prepared which are, chemicallyspeaking, solid solutions of free alumina in ordinary spinel.Alumin-ium atoms here occupy the place of magnesium, and the physicalformula must now be further simplified, so that it assumes the formY,O,, where Y now means (Mg,Fe, etc. ; Ti,Al,Cr, etc.). Machat-schki does not further pursue these developments, but it seems fairto remark that another step is probable, if not already necessary :The Y elements do not differ very widely in volume from oxygen,and if by any chance conditions should be realised in which one ofthem could replace oxygen in the space-lattice the physical formulawould undergo another, and presumably final, simplification intothe form Z, where Z might be any atom. Thus the increasing com-plexity of this series of compounds, judged from the chemicalstandpoint, is met, not by a corresponding development in thescope and diversity of the physical formula, but by its almostcomplete disappearance into the vaguest of generalities.Clearly,the X-ray analysis of such a complex group, yielding the formula%, would shed very little light upon the chemical formulae of thewell-known compounds present.24 Centr. Min., 1930, [ A ] , 191292 HALLIMOND :Mineral$.Elements.-The generally accepted theory that the gold depositsof the Rand conglomerate were formed as placer deposits has beenexamined by L. C. Graton,25 who gives a very full discussion of theevidence. On the grounds of the absence of detrital grains of goldand other heavy minerals, the fineness of the grain size, enrichmentof the top as well as the bottom of some reefs, and the prevalence ofauriferous quartz veins, he concludes in favour of hydrothermalorigin, from solutions infiltrating the conglomerate.C. D. Hulin 26describes an unusual gold vein from California, in which the ganguemineral is largely apatite. Diamond deposits on the Upper Ara-guaya River have been described by F. W. Freise; 27 and those onother Brazilian fields by A. P. L. B&im.28 Perhaps the mostfamous deposits in the world a t present are the raised beaches nearthe mouth of the Orange River in South-West Africa. These arebriefly described by A. L. Dutoit ; 29 the diamonds are concentratedalong the foot of the ascending storm beach a t the inner side of theraised beach terrace; by means of carefully contoured maps, asuccession of raised beaches has been traced, and the productivearea has been rapidly extended, so as to indicate some wider sourcethan the Orange River itself.Cz~rtisite,~~" a new hydrocarbon, has the formula C2,H,,.Thucholite 29b is interesting on account of its occurence withuraninite.Halides.-Detailed mineral analyses of the Solikamsk salt depositin Russia are given by J.V. Moratschevski; 30 N. N. Efremov andA. A. Veselovski 31 discuss the bromine content of the carnallites ;I. V. Poire 32 finds that their colour is due to iron oxide as needles,threads, and platelets. Sodium chloride and sylvite preceded theother salts, and G. G. Urazov 33 has discussed the order of crystal-lisation, which agrees with that in the quaternary system KCI-NaC1-MgCI2-H2O. Red salt from the southern United States wasalso found by J.E. Tilden 34 to contain matted tubules mingled withiron oxide ; they appear to be the remains of an organism for whichhe proposes the name Phormidium antiquum. One of the mostz5 Econ. Geol., 1930, May (supplementary volume).26 Ibid., p. 348.2 8 Bull. SOC. franp. Min., 1929, 52, 51; A . , 1930, 1016.2* Econ. Geol., 1930, 25, 653.295 Amer. Min., 1930, 15, 169.30 Ann. I n s t . Anal. Phys. Ghem., 1930, 4, 113; A., 1015.31 Ibid., p. 99; A . , 1015.82 Ibid., p. 85; A., 1015.34 Amer. J . Sci., 1930, [v], 19, 297; A., 670.27 Ibid., p. 203.29b Ibid., p. 499.33 Ibid., p. 41 ; A . , 1010GEOCHEMISTRY. 293striking occurrences of rock salt is the exposed salt plugs of SouthernPersia, described by J.V. Harrison; 35 the salt has here beenexthded on a large scale, and even forms " glaciers " that spreadoutward over the surrounding rocks.SuZphides and Xulpho-salts.-A remarkable occurrence of copperores in Alaska is described by X. G. L a ~ k y . ~ ~ The deposit is mainlychalcocite, which proves on inineragraphic investigation to be ofthe isometric (high-temperature) form. It occasionally exhibitsbanded structures which are believed to indicate deposition in acolloidal form above 90" ; this contained dissolved covellite whichseparated on cooling. Chalcopyrite, usually a vein-mineral ofrather late formation, is found in Montana 37 in a magmatic depositwhich is really a perthitic syenite composed mainly of orthoclaseand albite; platinum is present with the copper.Graphic inter-growths of the chalcopyrite and niccolite from Sudbury, Ont., aredescribed by C. Lausen,38 who concludes that the first deposit ofgersdorffite and quartz was shattered, with the introduction ofmaucherite followed by niccolite ; chalcopyrite then replaced theniccolite. The word " graphic " has been used to describe a varietyof inter-penetrant structures, due variously to simultaneous crystal-lisation from the melt, to " unmixing '' of a solid solution and toreplacement ; in the present case, although it is known that the twominerals are mutually soluble at high temperatures, and " unmix "on cooling, the author holds that the structures are due toreplacement.W.H. Newhouse and G. H. Flaherty39 have undertaken a com-parison between various types of the metamorphic copper ores ;these offer one of the most difficult geochemical problems, for it ishard to distinguish between deposits altered by the metamorphismand those due to chemical replacement of different mineral bandsin the schist.D. F. Hewett and R. N. Eove40 describe veins exhibiting thesequence rhodonite, alabandite, and rhodocroisite, the last in partreplacing the earlier minerals. The position of molybdenite in thesequence of deposition is dealt with by A. F. Buddington,P1 whodescribes a pegmatite from Alaska, in which sulphides replacesilicates in the sequence pyrite, sphalerite, pyrrhotite, chalcopyrite,molybdenite, followed by a zeolitic phase.W. F. Foshag andM. N. Short 42 have proved by mineragraphic examination t h a t amineral from Czechoslovakia with the composition of arsenoferrite,36 Econ. Geol., 1930, 25, 737. 35 Quart. J . Geol. SOC., 1930, 86, 463.37 Bull. U.S. Geol. Survey, 1929, 811, [A], 50.38 Econ. Geol., 1930, 25, 356.40 Ibid., p. 36.39 Ibid., p, 600.4 1 Amr. Min., 1930, 15, 428. 41 Ibid., p. 197294 HALLIMOND :FeS,, is isotropic; arsenoferrite is thus a true species distinct fromlollingite. A similar investigation of an arsenical ore from Silesiais given by H. S~hneiderhohn.~~ Violarite and other nickel sulphideshave been investigated by M. N. Short and E. V. Shannon,44 whofind that violarite from Sudbury, Ont., is identical with a nickelsulphide observed in several other ores with the formula (Ni,Fe),S,.The well-known sulphide minerals of Hungary have been describedby S.K o ~ h , ~ ~ who gives a method of aiialysis with descriptions ofmany bismuth and tellurium minerals. Nagyagite (analysed),proustite, and xanthoconite are described by L. T ~ h o d y . ~ ~ Othercomplex sulphides include miargyrite from California (E. V. Shan-n ~ n ) , ~ ' antarn~kite,~~ a new gold silver telluride from the PhilippineIslands, fiiloppite, 3PbS,4Sb,S3, a new mineral from Hungary (I. deFin&ly and S. K o ~ h ) , ~ ~ and ramdohrite, Ag2S,3PbS, a new mineralfrom Bolivia, described by F. Ahlfeld.50 D. Guisen 51 has made amineragraphic study of the sulpharsenites from the Binnenthal.Oxides.-Much interest has centred in the occurrence of cassiterite.The question how far the Bolivian tin deposits are due to oxidationof sulphides continues to be debated; J.T. Singewald 52 holds thatthe greater part is hypogene. Details of the crystal habit of severaltypes of cassiterite are given by F. Ahlfeld,53 who gives lists of theoccurrence of Bolivian sulphides and concludes against the down-ward migration of tin oxide. After quoting historical records,J. Hulmaier s4 gives an elaborate description of the crystal habit ofcassiterite from the chief known localities. An instructive exampleof the origin of primary tin veins is recorded by D. R. D e r r ~ , ~ ~ whodescribes a pegmatite in which the segregation of cassiterite-bearingstreaks has occurred towards the hanging wall during consolidationof the rock.Silica.-The name lechtelierite is proposed for natural fusedsilica, of which a remarkable occurrence is described by A.F.Rogers; 56 a t Meteor Crater (Coon Butte), Arizona, layers of silicaglass up to 6 inches in thickness are found a t the bottom of the43 Chem. Erde, 1930, 5, 385; A., 733.44 Amer. Min., 1930, 15, 1 ; A., 1551.4 5 Udn. Koh. Lapok, 1929, 62, 425 ; Chent. Zentr., 1929, ii, 2872 ; A., 1930,4 6 Gentr. Min., 1030, [A], 117.4 7 Proc. U S . Nut. Mus., 1929, 74, No. 21; A., 1930, 1397.4 8 Philippine J . Sci., 1930, 41, 137.49 Min. Mug., 1929, 22, 179; A., 1930, 189.bo Centr. Min., 1930, [ A ] , 365.5l Bull.Acad. Sci. Rournaine, 1929, 12, No. 7-10, 44.52 Econ. Qeol., 1930, 25, 91, 211.54 Jahrb. Min., Bei1.-Bd., 1930, [A], 61, 403.65 Emn. Gwl., 1930, 26, 146.734.53 Ibid., p . 546.s6 Arner. J. Sci., 1930, [v], 19, 196GEOCHEMISTRY. 295depression ; these are attributed to fusion of the sandstone on impactof the meteorite. Agate has been studied by H. he in^,^' who givesanalyses of the separate layers in flints from the chalk; artificialcolouring affected the layers containing most opal. F. A. Burt 58describes capsular silica from Texas. Quartz has been examinedby R. Wei1,S9 who finds that sections cut perpendicular to the axisindicate the existence of two types distinguished by optical proper-ties and etch-figures. Among other oxides, the emery deposits a tPeekskill are discussed by J.L. Gillson and J. E. Kama,60 whoregard the deposits as due to the reaction of magmatic solutionson the already consolidated margins of a norite mass, and on thesurrounding metamorphosed schist, which is stated to have anacid composition. Cobalt minerals, including a new mineralstccinierite, (Fe,Co,Al),0,,H20, from Katanga, are analysed byV. Cuvelier.61 Chromite is found in its purest form in meteorites;the ore-mineral varies widely in composition (L. W. Fisher).62E. S. Sampson and C. S. Ross 63 describe occurrences which theybelieve to indicate that chromite can be deposited at a late stagein mineralisation. Boehmite, A1,0,,H20, occurring as minutecrystals in bauxite, is shown by R. Hocart and J.de Lapparentto be homologous with lepidocrocite. Titanium in bauxite is shownby the latter 65 to occur always as a dust of highly refractive titaniumminerals. Among the oxides of iron, mention may be made ofpisolitic iron ores from Wiirttemberg, which are regarded byE. A. Ehmann 66 as " fossil laterites," while M. Solignac 67 describesa limonite oolite from Tunisia with pellicles of phosphate. Man-ganese oxide is sometimes deposited along with limonite by springwaters, but there is usually a tendency for one or other mineral topredominate ; examples are described by (Frl.) G. Schrenckenthal **in the cementation of gravels from the Marchfeld, while H. Lasch 69gives an account of manganiferous nodules dredged from the bed ofa lake in Upper Austria.Details of the oxides of manganese, withtheir occurrence and commercial uses, are given by E. Donath and67 Chem. Erde, 1930, 4, 501.58 Amer. Min., 1929, 14, 222; A., 1930, 187.69 Compt. rend., 1930, 191, 270; A., 1155.6o Econ. Geol., 1930, 25, 506.61 Natuurwetensch. Tijds., 1929, 11, 170; A., 1930, 188.62 Amer. Min., 1929, 14, 341; A,, 1930, 570.63 Econ. Qeol., 1930, 25, 219.64 Compt. rend., 1929,189, 995; A., 1930, 189.e6 Ibid., 1930, 190, 1312; A., 886.6e Chem. Erde, 1930, 6 , 117; A., 1397.e7 Compt. rend., 1930, 191, 107; A., 1166.66 Chern. Erde, 1930, 6, 51; A., 1398.b9 Tsch. Min. Petr. Mitt., 1930, 40, 294; A., 448296 HALLIMOND :H. Leopold.70 Magnetite has been found by E. L. Perry 7 l in theunusual form of fibrous veins, with granular magnetite a t the centre ;these occur in serpentine and are believed to be due to the replace-ment of asbestos.Jasper 72 containing magnetite and haematitehas been described from the metamorphic iron ores of Wyoming.Silicates.--Fibrous emerald-green actinolite (smaragdite), de-scribed by E. I I a r b i ~ h , ~ ~ occurs with chromite and magnesite inserpentine from Serbia. Anthophyllite fibre from Californiadescribed by J. I>. Laudermilk and A. D. Woodford 74 proves t ocontain 7.4% Na20 and is thus a new variety; it is fusible, butresists acid. Reference may be made here to the asbestos (chryso-tile) of Shabani, South Africa, which has been described by F. E.Keep.75 Another amphibole, blue-green in colour, from theMinnesota iron formation, is described by S.Richarz ; 76 it contains11-15y0 A120,, 7.92% Pe203, 1.67% Na20 ; this composition liesoutside the amphibole formulae recently advanced by Warren andPauling, and to meet the difficulty two new additional constituentformulz are proposed by Winchell.Spodumene deposits in Dakota are described by G. N. S ~ h w a r t z , ~ ~while C. Palache, S. C. Davidson, and E. A. Goranson 78 describe thehiddenite deposit of N. Carolina, which they regard as an exampleof pegmatitic mineralisation in three successive stages, the secondpegmatite injection carrying the lithia minerals, which are alsofound in cavities in the gneiss resembling Alpine clefts.Hypersthenisation and the chemical transformations in silicateminerals in general are discussed by D.GuirnarPe~.~~Olivine from Vesuvius, of very unusual composition, is describedby R. Koechlin ; 8O the crystals approximate to fayalite in propertiesand may represent an iron-rich member of the olivine series. Ananalysis by F. Schwartz of massive white beryl from the S. Tyrol isgiven by E. Dittler,81 and the same mineral has been found in Mainein radial aggregates up to 18 feet in length.82 Euclase from Italy,described by A. C a ~ i n a t o , ~ ~ resembles that from Brazil ; analysisconfirms the formula 2Si02,A1,03,2Ba0,H20.70 ( 6 Der Braunstein u. seine Anwendungen ” Stuttgart, 1929.71 Amer. J . Sci., 1930, [v], 20, 177.72 Bull. U S . Geol. Survey, 1929, 811, [DJ.7 3 Tsch. Min. Petr. Mitt., 1929, 40, 191; A., 1930, 57.74 Amer.Min., 1930, 15, 259.75 Third Empire Min. Congr., April, 1930.i 7 Econ. Geol., 1930, 25, 275.79 Ann. Acad. Brasil. Sci., 1930, 2, 1 ; A., 1156.80 Centr. Min., 1930, [ A ] , 375.81 Tsclz. Min. Petr. Mitt., 1929, 40, 188; A., 1930, 57.8? E. K. Geclney and H. Berman, Amer. Min., 1930, 15, 81.83 Atti R. Accad. Lincei, 1929, [vi), 10, 656; A., 1930, 445,‘e, Amer. Min., 1930, 15, 65.7 8 Amer. Min., 1930, 15, 280GEOCHEMISTRY. 297Garnet occurs in the Adamello Mountains in reddish-browndodecahedra, in composition mainly grossularia, and associatedwith olive-green vesuvianite ; analyses and physical constants forboth minerals are given by C. G ~ t t f r i e d . ~ ~ An unusual vesuvianite,with 9.20% of BeO, is described by C.Palache and L. H. Bauer.sbAnother garnet, from Avonda'le, Pa.,85a is shown to be a memberof the almandite-spessartite series. F. Zambonini and A. Ferrari 86discuss the crystalline structure and formula of cancrinite; andB. Z. Kolenko 87 describes the distribution of orthite in the Trans-baikal region. Samarskite from New Mexico, analysed by F. 1,.Hess and R. C . Wells,88 is believed to have been formed in twogenerations at different geological periods.A new silicate from New Zealand, named arneletite, is described byP. Marshall : 89 it appears to be a member of the nepheline groupand occurs in phonolite in minute crystals and grains that are readilystained by silver nitrate.Sapphirine from Italy has been analysed by H. P. Cornelius andE.Dittler.*o Steatite from Bavaria, described by F. De~bel,~l hasbeen formed by the replacement of quartzite. Highly aluminousaltered shales near Postmasburg, S. Africa, contain the interestingminerals diaspore, kaolin, leverrierite, and zunyite ; the last isdescribed by L. T. Nel and L. J. Spencer,92 who discuss the com-position in the light of analyses by J. McCrae and H. G. Weall.Gillespite, FeBaSi,O,,, occurs with celsian and hedenbergite, forwhich composition and properties are recorded by W. T. S ~ h a l l e r . ~ ~Scazotite, a new mineral from Co. Antrim described by C. E. T i l l e ~ , ~ ~occurs in vesicles in a hybrid rock formed by the action of a doleriteintrusion upon chalk; it is allied to spurrite, and analysis byM.H. Hey agrees with the formula 6Ca0,4Si0,,3C02.M. H. Hey 95 has investigated the variation of optical propertieswith chemical composition in the rhodonife-busfamite series. Theminerals are all anorthic, but exhibit variations in the facility ofcleavage; density and refractive indices are plotted direct, and itis shown that at 30 mols.% of CaO there is a change in optical sign84 Chem. Erde, 1930, 5, 106. 85 Amer. Min., 1930, 15, 30; A., 1551.85a Ibid., p. 40. Atti R. Accad. Lincei, 1930, [vi], 11, 782; A., 1397.8 7 Bull. Acad. Sci. Leningrad, 1929, 243.Amer. J . Sci., 1930, [v], 19, 17; A., 316.8D Min. Mag., 1929, 22, 174; A., 1930, 189.So Jahrb. Min., Bei1.-Bd., [ A ] , 1929, 59, 27; Chem. Zentr., 1929, ii, 1640;9l Chem. Erde, 1930, 5, 87.O4 [With M.H. Hey] Min. Mag., 1929, 22, 222; A., 1930, 569.9 5 Ibid., p. 193; A., 188.A., 1930, 316.s2 Min. Mag., 1930, 22, 207; A., 570.Amer. Min., 1929, 14, 319; A., 1930, 670.K 298 HALLIMOND :which is taken as a convenient division between the two mineralsforming the series.Chabazite has been shown by Y. Tanaka and M. Nakamura 96 toundergo a continuous dehydration on heating up to about 1000" C.It has no adsorptive power even when dehydrated. Heulandite hasbeen studied by P. Gaubert.97 Crystals occurring at N. Burgess,Ontario, have been identified by R. P. D. Graham and H. V. Ells-worth 98 as cenosite, one of the interesting group of silico-carbonates.Fezspars.-A very detailed examination of the moonstones hasbeen contributed by E.Spencer,g9 who has confirmed the observ-ation that the schiller and microperthitic structures are destroyedby heating to about 1050". He h d s that lamellar albite is selec-tively attacked by water and carbon dioxide under pressure, whichmay explain the fact that in some of the natural specimens albite hasbeen completely removed. These results confirm the general viewthat the peculiar structure of moonstone is due to the separation oncooling of the potash and soda felspars, which are completelymiscible in the solid state at high temperatures. Several analysesare given, which lead to certain modifications in the equilibriumdiagram for these compounds. The peculiar optical properties ofmoonstone have also been discussed by A. L. ParsonsYgga withspecial reference to the material from Ontario.Potash felspar apparently exists in dimorphous forms, corre-sponding with orthoclase (monoclinic) and anorthoclase (anorthic).K.Chudoba has examined the well-known felspar from the trachyteand xenoliths of the Drachenfels and finds that both are anorthic;for this variety he proposes the name sanidine-anorthochse.The occurrence of potash in the soda-lime felspars is now commonly taken account of, but D. Beliankin2 points out that otherminor constituents cannot be neglected. In a chemical investigationhe shows that iron may be present up to 2-3%, whilst barium isoften found in the acid felspars : the analyses in certain cases cannotbe reconciled with existing theory. Very pure adularia from Japanhas been analysed by K.set^,^ and H. S. Spence gives analyses ofalbite and microcline in il description of the pegmatites of Ontarioand Quebec, where felspar crystals up to 30 feet in length havebeen found. F. C. Phillips 5 discusses the pericline twinning of96 J . SOC. Chem. Ind. Japan, 1930, 33, 274.97 Bull. SOC. franc. Min., 1929, 52, 14.Ss Min. Mag., 1930, 22, 291; A., 1397.99n Amer. Min., 1930, 15, 93.Bull. Acad. Sci. U.S.S.R., 1929, 571; A., 1930, 57.J . Petr. Min. Ore Deposits, Japan, 1929, 1, 278.Amer. Min., 1930, 15, 450.Min. Mag., 1930, 22, 225; A., 570.9a Amer. Min., 1930, 15, 206.Centr. Min., 1930, [ A ] , 145GEOCHEMISTRY. 299acid plagioclase, and T. F. Barth has described the anorthites fromthe Adirondacks. Anomalies in the order of zoning of plagioclasehave been observed by K.Ch~doba.~Clays.-Much work is recorded upon kaolinite and the more acidclays. These minerals, though often minutely crystalline, are noteasy to differentiate, but a measure of success has recently beenobtained by combining accurate physical determinations with X-raymeasurements of the crystal structure.conclude that the kaolin minerals really belong to three distinctspecies : kaolinite, the chief constituent of china clay; dickite, ilname now proposed for the mineral first described from Angleseyby A. B. Dick; and nacrite, well known from Freiberg. Kaoliniteis much more strongly stained by dyes, but is otherwise very similarto nacrite, while dickite differs in crystal habit and optical properties.AII three minerals give distinctive X-ray patterns. P.Schacht-schabe19 has studied the dehydration of kaolin; the water isregained under pressure at 200"; the rehydrated mineral, which isa t first soluble in hydrochloric acid, gradually approximates inproperties to ordinary kaolinite. Kaolin from a metamorphosedash in N. Carolina is described by J. L. Stuckey ; 10 K. Set0 l1 givesanalyses of material from Korea and Japan; and S. Malkowski andM. Kowalski 12 discuss the occurrence of clays in Poland. Halloysitenodules in limonite from the Harz are described by 0. H. Erdmanns-dorffer ; l3 this mineral loses very little water up to 400", after whichit behaves like kaolin. The more acid clays, usually containingmontmorillonite, have considerable commercial importance.Theyoften result from the alteration of volcanic ashes and have thecomposition ~ 2 0 3 , 3 s i o , with a high content of loosely held water.K. Kobayashi and K. Yamamoto l4 describe the Japanese acid clay,which is an altered liparite; the dehydration curve determinedby those authors and K. Bit6 l5 differs from that of kaolin, whileX-ray diffraction lines indicate the presence of a distinctive mineral.16Bentonite from Arizona, probably formed from volcanic ash thatfell into water, is shown by V. T. Allen l7 to consist chiefly ofmontmorillonite, while E. S. Larsen 1* also describes tuffs fromAmer. Min., 1930,15, 129.A w r . Min., 1930, 15, 34; J . Amer. Ceram. SOC., 1930,13, 151; A,, 560.51 Chem.Erde, 1930, 4, 395; A., 315.l1 J . Petr. Min. Ore Deposits, Japan, 1929,1, 179; A., 1930, 570.l2 Tram. Ceram. SOC., 1930,29, 142; A., 1397.Chem. Erde, 1930, 5, 96; A., 732.l4 J . SOC. Chem. Id. Japan, 1929, 32, 174; A., 1930, 316.l6 Ibid., p. 297; A., 316.1e N. Kameyama and S. Oka, ibid., 1930, 33, 29, 92; A., 448, 1017.l7 AWW. J . Sci., 1930, [v], 19, 283.C. S. Ross and P. F. Kerr' Centr. Min., 1930, [ A ] , 145.lo Amer. Min., 1930, 15, 10.Bull. U.S. Geol. Survey, 1929, 811, [B], 89300 HALLIMOND :Colorado altered to bentonite, and F. Tucan 19 describes a similarsilicate having a continuous dehydration curve, from Allchar inSerbia. Nontronite, which has been regarded as ferric kaolinite,appears to belong with the present group, for materials fromBavaria *O and from Pontevedra 21 both show continuous dehydr-ation a t low temperatures and approach the composition R20,,3Si0,.Another member of the group, with 7% of ferrous oxide, nearbeidellite in composition, is described by I.J. Mickey.22Phosphates.-Near Fairfield, Utah, phosphate nodules from lime-stone have yielded a remarkable series of minerals described byE. S. Larsen and E. V. Shannon.23 Wardite,2Na20,Ca0,6A1,03,4P205, 1 7H20,is shown to be a good species; variscite and pseudowavellite arecommon. New species are deltaite, 8Ca0,5Al2O3,4P2O5, 14H20 ;dennisonite, 6CaO,Al2O3, 2P205 ,5H20 ; dehmite,14Ca0,2 (Na,K),O ,4P205 ,3H20,C02,also described from Dehrn with crandallite, Ca0,2A120, ,P20, ,GH,O ;lewistonite, 15Ca0, ( K,Na),0,4P205, 8H20 ; englishite ,4Ca0,K20,4A120,,4P205,14H20 ;millisite, 2Ca0,Na20,GA120,,4P205, 17H20 ; lehiite,5Ca0 , ( Na,K),0,4A120,, 4P20,, 1 2H20 ;gordonite, Mg0,A1203,P205,9H20.These species are identified bytheir distinct physical properties, and there are many other sub-stances not yet fully described. Another set of phosphates,described by H. Berman and F. A. G ~ n y e r , ~ ~ occurs in pegmatitesa t Poland, Maine ; amblygonite replaces felspar ; analyses are givenof lithiophilite, 2(Mh,Fe)0,Li20,P,05 ; reddingite,3 (Mn ,Fe) 0 , P20 , 3H20 ;dickinsonite , 7 (Mn,Fe) 0,2 (Na, ,K2 ,Ca) 0 ,3P205 , H,O ;(Mn, Fe)O , 2Ca0 , P205, 2H20 ; landesi t e (new sp . ) ,3Fe20, ,20Mn0,8P205 ,27H20.f airfieldite ,Other phosphates described include lazulite from Chittendcn,Vermont ; 25 collophane and variscite (Styria).26 H.R. von Gaert-ner 27 examines natural and artificial pyrochlore by X-rays. Theartificial substance is cubic, but natural pyrochlore is " metamict "and only assumes the cubic structure on ignition. The new mineralbismutotanhlite, Bi20,,Ta205, is described by E. J. Waylnnd and1920212223242 62 7Bull. SOC. franc. Min., 1929, 52, 42; A., 1930, 1156.W. Noll, Chem. Erde, 1930, 5, 373; A., 733.I. P. Pondal, Arq. Seminario Est. GaZegos, 1929, 2, 9 ; A., 1929, 1418.Centr. Min., 1930, [A], 293.Amer. Min., 1930, 15, 303.Ibid., p. 375.F. Machatschki, Centr. Min., 1929, [ A ] , 321.Jahrb. Min., Bed.-Bd., [ A ] , 1930, 61, 1.26 Ibid., p.338GEOCHEMISTRY. 301L. J . Spencer.28 The mineral occurs in a pegmatite in Uganda, incrystals up to several pounds in weight ; in composition it corre-sponds with stibiotantalite.Seamunite, a new mineral, has the interesting composition3Mn0,(B,03,P20,),3H,0; it, is described by E. H. Kraus, W. A.Seaman, and C. B. S l a ~ s o n , ~ ~ from Michigan. It is apparentlyreddingite with part of the P,O, replaced by B203.Carbonates.-J. Romieux30 has made a detailed study of thedistribution of carbonates in the mud of Lake Geneva. Recentalgal limestones from S. Australia are described by D. Mawson,31and A. L. Mathews 32 concludes that the ooliths of Great Salt Lakeform a t the water’s edge and grow by evaporation of capillary wateras they are driven inland by the wind, for they are sometimes zonedwith soot.S. Mizgier 33 shows that lublinite is identical with calcite.Structures have been proposed for alstonite and barytocalcite,34and analyses are given for gaylussite, nesquehonite, and probertite.FeS04,2ZnS0,, 18H,O,is described by C. A ~ ~ d r e a t t a . ~ ~ (Miss) J . M. Sweet 36 gives anaccount of the occurrence of barytes in Great Britain, and thegeology and chemistry of gypsum in New York are discussed byD. H. Ne~land.~’ Uraninite 38 from Villeneuve, Quebec, yields avariable lead ratio, depending upon the degree of alteration; R. C.Wells 39 gives an analysis of pitchblende occurring with gold in acalcite vein from Chihuahua, Mexico.Mineral Springs.-Space will not permit detailed reference to thelarge output of records for mineral springs.American localitiesinclude N. Carolina,40 Arkansas hot springs,41 and oilfield water inAlberta; 42 data are given for the manganese content of theMississippi River.43 Physical constants, etc., for Italian springsSulphates, etc.-Bianchite, a new white mineral,2 8 Min. Mag., 1929, 22, 185; A . , 1930, 188.2s Amer. Min., 1930, 15, 220.30 Arch. Sci. phys. nut., 1930, 12, 202; A., 1155.31 Quart. J. Geol. SOC., 1929, 85, 613; A., 1930, 315.32 J . Geol., 1930, 38, 633.33 2. Krist., 1929, 70, 160; Chem. Zentr., 1929, ii, 544; A., 1930, 188.34 Centr. Min., 1930, [A], 220, 321.35 Atti R. Accad. Lincei, 1930, [vi], 11, 760; A., 1397.36 Min. Mug., 1930, 22, 257; A., 1156.3 7 New York State Mus.Bull., No. 283, 1929.38 Amer. Min., 1930, 15, 455.3g Ibid., p. 470.40 E. E. Randolph, J . Elisha Mifchell Sci. SOC., 1928, 44, 7 0 ; A., 1930, 187.4 1 Ind. Eng. Chem., 1930, 22, 633.43 Trans. Canad. Inst. Min. Met., 1929, 32, 316.43 Science, 1930, ‘71, 248302 HALLIMOND :are furnished by D. Marotta and C. S i ~ a , ~ ~ R. Nasini and E. Bova-lini,45 and for Sardinia by E. Puxeddu and G. Sanna.46 AtC h o ~ s s y , ~ ~ France, the medicinal water contains arsenic ; tadpoleskept in the well-water showed an increased arsenic content, butthis was not so marked when they lived in the bottled water.Other European localities include Upper Checkya ( Caucasus),48Zagreb 49 district, and Lower Kostrivnica, Jugoslavia. 5O Hydrogen-ion concentration has been determined by M.C. PotterY5l while0. Baudisch and H. von Euler 52 discuss the phthalein reaction inrelation to the state of combination of the iron present. Estimatesof the rarer elements have been made spectroscopically on the waterof Cambres by A. P. F ~ r j a s , ~ ~ and radioactivity determinations byV. Vernadsky 54 (deep springs in Russia) and others. Colorimetricdeterminations of uranium content on water from Caria, Portugal,are due to H. de C a r ~ a l h o . ~ ~ 0. W. Rees 56 considers that silicain natural-water analyses should be taken into account as an acidradical SiO,.Distribution of Iodine.-Minute amounts of iodine have beenmeasured in air, dew, in various food-stuffs, and in soils and waters ;a survey of the quantity available from these sources a t Salta(Argentine) 57 indicates that the average daily intake of iodine perperson is below 0.04 mg. and is inadequate.This is primarily dueto lack of iodine in food-stuffs, which compare unfavourably withthose in non-goitrous districts, even the sheep’s thyroid glandshowing corresponding deficiency. Iodine surveys are also reportedfrom N. and S. Carolina 58 and Nebraska.59 Sea-water examinedby Winkler’s method60 contains only a small amount of iodine,and the content varies little with the depth. Coal heated withalcohol and potassium carbonate in an autoclave yields a filtrate44 Ann. Chim. Appl., 1929, 19, 529; A., 1930, 448.4 5 Ibid., 1930, 20, 56, 91; A., 569, 731.4 6 Giorn. Chim. Id.Appl., 1929, 11, 438; A., 1930, 187.47 Compt. rend., .1930, 190, 1133.49 G. Janehek, Arhiv Hemiju, 1929, 3, 178; A., 1930, 187.50 Bull. SOC. Chim. Roy. Yougoslavie, 1930, 7, Reprint.51 Nature, 1930, 126, 434; A,, 1396.52 Biochem. Z., 1929, 212, 140 ; A., 1929, 1417.53 Compt. rend., 1929, 189, 703; A., 1929, 1417.54 Ibid., 1930, 190, 1172.5 6 Ind. Eny. Chem. (Anal.), 1929, 1, 200; A., 1920, 1417.5 7 P. Mazzocco, Semana mkd., 1930, 37, 358, 364, 366, 370; A., 1015.58 J. H. Mitchell, Science, 1929, 69, 650; A., 1920, 1418; J. W. Perry,59 W. H. Adolph and F. J. Prochaska, J . Amer. Ned. Assoc., 1929, 92,6o J. F. Reith, R ~ c . t r ~ . chim,, 1930, 49, 142; A., 315.4 8 J . Appl. Chena. Russia, 1088, 1, 291.55 Ibid., 191, 95; A., 1155.J .Elisha Mitchell Sci. SOC., 1928, 44, 87 ; A., 1930, 187.2155 ; A., 1929, 1427GEOCHEMISTRY. 303which can be tested by Winkler's method ; twelve mid-Europeancoals show up to 11.17 mg. per kg. By the combustion of coal7,000,000 kg. of iodine are probably returned to circulationannually.61 Domestic and drinking waters in E. Prussia sometimesshow a high content of iodine.62Sea-wuter.-The composition of the sea near Puget Sound isdiscussed by T. G. Thompson 63 and others, who give determinationsof pn, chlorine, and dissolved oxygen. I n the North Pacific theionic ratios are constant, namely Ca/Mg 0.3212; Ca/C1 0.0215;Mg/ClO*O669. E. G. Moberg 64 discusses the hydrogen-ion, phosph-ate, silicate, and fixed nitrogen contents of sea-water. Water fromthe Red Sea 65 has a very low nitrate content, owing t o the pre-dominance of denitrifying bacteria ; in consequence, vegetation isscanty.Seasonal variations in phosphate, silicate, and nitratecontent in the English Channel G6 are correlated with outbursts ofphytoplankton. D. Ellis and J. H. Stoddart 6' describe the chemicaleffects of sulphur bacteria growing in pools.Muds.-Considerable attention has been given to the compositionof sea and lake muds. H. H. Moore 68 finds that both phosphatesand nitrogen diminish with increasing depth in the sea muds ofthe River Clyde. In Black Sea muds69 the phosphorus variesinversely with the organic content ; vanadium was also determined.In Lake Saki,70 white deposits of gypsum and sand alternate withblack clays which owe their colour to hydrotroilite.The claysreact with the salts in solution, and the deposits show seasonalvariations. Other factors are the adsorption of salts and thebiochemical reduction of sulphates; in the dried mud the latterdepends on the sodium chloride content.The Origin of Coal.-Details of the coal-forming reactions are stillkeenly debated. A. Duparque 71 suggests that the primordialdeposits were of two distinctl types, represented by spores, cuticleson the one hand and woody tissue on the other. These have thesame chemical composition, and the differences in the coals producedare assigned to secondary changes that vary according to the depth6 1 E. Wilke-Dorfurt and H. Romersperger, 2. anorg. Chem., 1930,186, 159 ;A., 449.62 H. Matthes and G. Wallrabe, Pharm. Zentr., 1930, 71, 273; A., 886.63 Pub. Puget Sound Biol. Sta., 1929, 7, 65, 119; A., 1930, 731.64 Proc. I11 Pan-Pacific Sci. Gong., 1926, (1928), I, 221 ; A., 1930, 187.65 G. Bini, Atti R. Accad. Lincei, 1929, [vi], 9, 1128.66 W. R. G. Atkins, J . Marine BioZ. ASSOC., 1930, 16, 821; A., 886.67 J . Roy. Tech. Coll. Qlasgow, 1930,2,336 ; A., 569.68 J . Marine Biol. ASSOC., 1930, [ii], 16, 596 ; A., 448.6s Bull. Acad. Sci. U.S.S.R., 1930, 206.70 P. T. Ivanov, Ann. Inst. Anal. Phys. Chem., 1930, 4, 197; A., 1015.7 1 Compt. rend., 1930,190, 1200; A., 887304 HALLIMOND : GEOCHEMISTRY.of water, shallow waters yielding anthracites, while the deepestwaters yield the boghead coals. H. E. Armstrong 72 concludes thatcoal is “ a condensed material, a natural bakelite.” G. Stad-nikov 73 discusses in detail the reactions which must have gone toform the Sumpfowy seam, a coal of intermediate character, andsuggests that the fats of the algae from which coorongite has formeclmust have been reduced by anaerobic bacteria in deep salt water,and subsequently oxidised at the surface. Continued anzrobicdecomposition would yield petroleum. The “ lignin theory ” hasbeen warmly debated. G. Stadnikov and L. Kaschtanov 74 discussthe chemical character of the compounds that form the Siberianboghead coals ; on hydrogenation the cyclic acids eliminate carbondioxide and are transposed into cyclic hydrocarbons. No phenolsare formed.Meteorites.-Material from the following localities has beenanalysed : Sandia Mts. ; Hinojo, Buenos Aires ; El Mocovi ;Cachari; Renca (San Luis); Isthilart; Piedad do Bagre, MinasGeraes. Small amounts of germanium and arsenic have beendetected.75 J. Young has studied the orientation of kamacite, 76and a general account of the composition and structure has beengiven by G. P. Merri11.77 A new iron meteorite from Carbo, Mexico,is described by C. Palache and F. A. G ~ n y e r . ~ ~A. F. HALLIMOND.72 Proc. Roy. Xoc., 1930, [ A ] , 127, 268; A., 887.73 Brennstoff-Chem., 1929,10, 477; A., 1930, 190.74 Ibid., p. 417; A., 57.T 5 J. Papish and Z. M. Hanford, Science, 1930, 71,269; V. M. Goldschmidt,Z . physikal. Chern., 1930, 146, 404.7 6 Min. Mag., 1930, 22, 383; A., 1398.7 7 Bull. U.S. Nat. Museum, 1930, No. 149; A., 1157.78 Amer. Min., 1930, 15, 388

ISSN:0365-6217    

DOI:10.1039/AR9302700283

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

SUB-ATOMIC PHENOMENA AND RADIOACTIVITY.THE important work of the two years (1929-30) under reviewhas for the most part been physical in character. The new wave-mechanics has been applied to the interpretation of the subjectand with increasing success to such processes as the emission ofa-particles from the nucleus and the disintegration of the nucleiof the lighter elements by swift or-particles; it is clearly going toplay an important part in future work. For the first time newisotopes have been discovered from an examination of band spectra ;the new method promises to reveal isotopes at concentrations belowthose ordinarily detected by the mass-spectrograph. Interestingtheories and speculations have been advanced on the nature of theproton, its relation to the electron, and their relative masses, alsoon the connexion between certain of the fundamental constantsof nature.On the chemical side, progress has been made with" the actinium problem," but an important, possibly a decidingdatum, the atomic weight of protoactinium, has still to be deter-mined before the outstanding difficulties of the subject are clearedup. The publication a t the close of the period of " Radiationsfrom Radioactive Substances " by Lord (formerly Sir E.) Ruther-ford, J. Chadwick, and C. D. Ellis has given students of radio-activity an admirable summary of the subject on the physicaland mathematical sides, and one of unique authority. As the titleimplies, however, the book covers a narrower range of subjectsthan earlier works by the senior author ; the chemical and geologicalsides of radioactivity are excellently but only briefly touched upon.A summary of work on p-particles and y-rays, and other subjectstoo purely physical in nature to be reported upon here, is given i n .this book.Isotopes and Mass-Spectra.During the period, knowledge of the isotopic constitution ofnine elements has been extended.The results are summarisedin Table I.The new isotopes of carbon, nitrogen, and oxygen have beenfound by detecting and interpreting isotopic lines in band spectraalong the lines suggested first by R. S. Mu1liken.l The first to befound were those of oxygen. Working on data provided for them1 Ann. Reports, 1926, 23, 284306 RUSSELL :TABLE I.Atomicnumber.Element .Carbon .........................6Nitrogen ........................ 7Oxygen ......................... 8Chromium ...................... 24Krypton ........................ 36Molybdenum .................. 42Xenon ......................... 54Tungsten ........................ 74Mercury ........................ 80Minimumnumber ofisotopes. of intensities.Masses of isotopes in order2 12, 13.2 14, 15.3 16, 18, 17.4 52, 53, 50, 54.6 84, 86, 82 and 83, 80, 78.7 98, 96, 95, 92, 94, 100, 97.9 129 and 132, 131, 134, 136,130, 128, 126 and 124.4 184 and 186, 182, 183.7 202, 200, 199, 201, 198, 204,196.by C. H. Dieke and H. D. Babcock,2 W. F. Giauque and H. L.Johnston ascribed the weak doublets of the atmospheric absorp-tion bands of oxygen to a molecule 0 1 6 0 1 8 .I n a later communica-tion,* they found other lines which are considered to originate fromthe molecule 0 1 6 0 1 7 . The abundance of these new isotopes issuch as not to be detectable by the new mass-~pectrograph.~ Theproportion of 0 1 6 to 0 1 8 is estimated as 1250 : 1 by H. D. Babcockand also by E. Moles,' and as 1075 -J-- 110 : 1 by S. M. NaudB.s Thatof 0 1 6 to 0 1 7 is given as lo4 : 1 by W. F. Giauque and H. L. Johnston4and also by E. Moles.' By a study of the isotope effect in thenitric oxide bands, S. M. Naudd 8 discovered the isotope N 1 5 . Bandheads were observed in the three bands investigated correspondingwith the calculated heads for the molecules W O 1 6 , N15O16, N14O18,and N 1 4 0 1 7 .These indicate the existence of a new isotope N 1 5and confirm 0 1 7 and 0 1 8 . The relative abundance of N 1 4 to "5was found to be 700& 140. This work has been confirmed byG. Herzberg,g who investigated the second positive group of nitro-gen. No evidenceof a third isotope N 1 6 was found. Carbon also is not a simpleelement. A. S. King and R. T. Birge lo found evidence of theexistence of the molecule C12C13 in the Swan spectrum of neutralC,, and R. T. Birge 11 of C13O16 in absorption spectrograms of COYand of C W 1 4 in the furnace (emission) spectrogram of CN.Although the evidence is conclusive for the existence of C13016 and3 Nature, 1929, 123, 318; A., 1929, 369. Ibid., p. 831; A . , 1929, 736.6 Ibid., p.761; A . , 1929, 624; Proc. Nat. Acad. Sci., 1929, 15, 471; A.,His value of the relative abundance is 800 : 1.Proc. Nut. Acad. Sci., 1927, 13, 670, and unpublished.F. W. Aston, ibid., p. 488; A., 1929, 484.1989, 971.Anal, Fis. Quim., 1930, 28, 127; A., 515.8 Physical Rev., 1939, [ii], 34, 1498 ; 1930, 35, 130; 36, 333 ; A., 1232.2. physiknl. Chem., 1930, [B], 0, 43; A., 1084.lo Nature, 1929, 124, 127; A., 1929, 970. 11 Ibid., p. 182; A,, 192'3, 970SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 307C13N14, it is neutral as to that of C12018, and decisive against thatof C12N15 and C12N16. R. T. Birge concluded that C13 is moreabundant relative to C12 than is N15 or N16 to N14, but no exactdata are given.lla Although further confirmation and extension ofthese interesting new results is desired, the results already obtainedshow that the examination of band spectra afford in certain casesa powerful means of detecting isotopes which are present inrelatively small abundance.In the mass-spectrograph very faintlines must necessarily be ascribed to possible impurities, but aseach molecule has its own spectrum, impurities in spectra, exceptin so far as they obscure the lines desired, are immaterial. On theother hand, however, the mass-spectrograph method has the greatadvantage of giving the absolute masses of isotopes and accuratelymeasuring their relative abundance ; the band spectrum methodgives only the relative masses of two isotopes and, as recent work 12has indicated, the intensities of the bands may not be a true measureof the relative abundance of isotopes.One further result has beenobtained by this method, vix., the possible existence of C139. H.Becker l3 found a third satellite to each absorption line in thehydrogen chloride rotation-vibration spectrum which is satis-factorily explained by the presence of this isotope. This hasrevived an old suggestion of F. W. Aston which was later rejectedby him. Confirmation of the existence of this isotope is highlydesirable, for it would make chlorine the first element of odd atomicnumber to have more than two isotopes and would make 39 thefirst isobare of odd mass-number to be shared by two elements ofodd atomic number.Continuing his work with the new mass-spectrograph, F.W.Aston has determined the isotopes of chromium,14 molybdenum,l5and tungsten,l6 using in each case as source a preparation of thecarbonyl. For chromium the mass numbers are 52, 53, 50, and54 in the relative abundance of 81-6,10-4,4.9, and 3.1% respectively.The packing fraction x lo4 for Cr52 is - 10 & 3 ( 0 1 6 = 0). Thecalculated atomic weight derived from these data is 52.011 & 0.006.For molybdenum the mass numbers are 98, 96, 95, 92, 94, 100, and97 in the relative abundance of 23.0, 17.8, 15.5, 14.2, 10.0, 9.8,and 9.6% respectively. The packing fractions x lo4 for M098and MofOO are both approximately - 5.5. The calculated atomicweight is 95.97 & 0.05. For tungsten the mass numbers are 184,The abundance ratio C13 : CI2 is non given as 1/400 by A.S. King andR. T. Birge; Aetrophye. J., 1930, 72, 19; A., 1931, 15.12 A. Elliott, Nature, 1930, 126, 203; A., 1232.13 2. Physik, 1930, 59, 601; A., 393.1 5 Ibid., p. 348; A., 1338.l4 Nature, 1930, 126, 200; A., 1232.l6 Ibid., p. 913; A., 1931, 15308 RUSSELL :lS6, 182, and 183 in the relative abundance of 30.1, 30.0, 22.6, and17.2% respectively. The packing fraction was not accuratelymeasured but is probably zero. The calculated atomic weight is183.96. In these three cases the atomic weights derived from thedata are, it is seen, in excellent agreement with those obtained bychemical means. In another piece of work,17 however, evidenceis adduced by the same author that the accepted atomic weightsof krypton and xenon (obtained by physical means) are decidedlylower than those obtained from the data furnished by the mass-spectrograph.He gives details of a method by which the relativeabundance of isotopes may be deduced with fair accuracy fromthe photometry of their lines in mass-spectra, and adds numericalresults for the isotopes of krypton, xenon, and mercury. Thenotion of isotopic moment is introduced. This is defined as thesum for all the isotopes of the product of abundance and distancefrom the mean mass number on the mass scale. This constantis not only roughly proportional to the error to be expected in anatomic weight calculated from mass-spectrum data, but is also anaccurate measure of the ease with which the atomic weight maybe altered, per unit, in the laboratory by such methods as diffusionor free evaporation.The isotopic moments for krypton, xenon,and mercury are calculated to be 0.87, 1.71, and 1.40 respcctivelyand the corresponding atomic weights are found to be 83.77 & 0.02,131.27 -+ 0.04 and 200.62 & 0.05 on the (chemical) scale 0 = 16.The value for mercury is in good agreement with the acceptedvalue, but each of the others is approximately a unit higher. Thesediscrepancies cannot be ascribed to impurities : suspicion is thrownon the limiting-density method of deriving the values hithertoaccepted. In this research, the order of abundance of isotopesof both xenon and mercury has been slightly modified and is thatgiven in Table I. One peculiar and possibly important new featuredisclosed is the exact equality in the abundance of certain isotopesof even-numbered elements.Thus Kr82 and Kr83 are each 11-79y0of the whole; Xe124 and Xe126 are each 0-0870, whilst W18* andW 8 6 , as the data given above show, are very close in abundance.Several series of experiments have been carried out t o test theunvarying nature of the atomic weights of naturally occuring com-plex elements. R. K. McAlpine l5has failed with antimony, T. W. Richards and A. W. Phillips l9with copper, G. P. Baxter and S. Ishimaru witn nickel,20 and H. P.All have given negative results.l7 Proc. Roy. Xoc., 1930, [ A ] , 126, 511; A., 393.J. Amer. Chem. Xoc., 1929, 51, 1745; A . , 1029, 071.ID Ibid., p. 400; A,, 1929, 370.2O Ibid., p. 1729; A., 1929, 863SUB-ATOMIC PHENOMENA AND RADIOACTIVITY.309Cady and H. U. Beecher21 with nitrogen. At the present time,therefore, boron remains the only element to be different in itsisotopic composition according to the part of the world whence itcomes.In the laboratory the work of partially separating isotopes hasbeen continued. F. A. Jenkins 22 has succeeded in obtaining chlorinewith so low an atomic weight as 35.418. A. A. S ~ n i e r , ~ ~ however,after 13 evaporations of cadium in a vacuum, in each of which halfthe material was removed, failed to obtain a difference in thisconstant. The same author z4 discusses critically schemes forfractionating complex elements.The first forty elements without exception have now been invest-igated for isotopes.Themasses still unassigned to any element are in the first decade 2, 3,5, and 8 ; in the next two none ; in the fourth 38 ; in the fifth 42,43, 46, 47, and 49 ; in the sixth 57 ; in the seventh 61 and 62 ; inthe eighth and ninth none. Those in the forties may be discoveredwhen F. W. Aston applies to calcium, scandium, titanium, etc.,the intensive examination to which chromium, molybdenum, andtungsten have lately been submitted, but the masses 2, 3, 5, and8 are in different case : 2 and 3 are unlikely ever to be found inhydrogen since they differ relatively so much from the knownisotope 1. There is a possibility of 5, however, for helium, and bothin band-spectrum work and in an examination of a-particles (in theactinium series) a sharp look-out for this possible isotope mightbe repaid.8 is a possibility for beryllium, about which an interest-ing suggestion has been made by Lord R a ~ l e i g h . ~ ~ R. d’E. Atkin-son and F. G. Houtermans,26 in a theoretical investigation of theprobability that a proton which has entered a nucleus will anchoritself there by radiating and so build up heavier elements out oflighter, find this possibility much improved if electrons can alsopenetrate the nucleus. They find that the isotope Be8 will be oneof such products, but will be so unstable as almost certainly tobreak up into two helium nuclei. This statement has led LordRayleigh, who many years ago found that the mineral beryl alwayscontains helium without appreciable quantities of radioactivematter, to suggest that this helium may possibly have arisen fromBe8.If this could be proved, it would indicate that Be8, even ifThe range of masses is from 1 to 94.21 Science, 1928, 68, 594; A., 1929, 863.22 Abstr. Theses Univ. Chicago (Sci. Ser.), 1926-26, 4, 93; A., 1929, 115.z3 Ibid., p. 173; A., 1929, 115.24 J. Physical Chem., 1929, 33, 577; A., 1929, 666.25 Nature, 1929, 123, 607 ; A., 1929, 487.26 Ibid., p. 567; A., 1929, 487310 RUSSELL :it does not now exist, has done so within geological times and sub-sequent to the formation of the mineral.The discovery of the complexity of oxygen necessitates a re-consideration27 of the scale on which the weights of atoms areexpressed. The present chemical standard is greater than themass of its main constituent 0 l 6 by about 1.26 parts per 104.Thisqimntity is of little significance to chemists, partly because i t isvery small and partly because the isotopic constitution of oxygenis probably invariable, but physicists aiming a t an accuracy in themasses of atoms of 1 part in lo5 parts must find the chemical unitunsuitable. The masses of the proton, the neutral hydrogen atom,one-quarter of the neutral helium atom, one-sixteenth of the neutraloxygen atom, 0l6, have been the chief suggestions for the standardmass. It should be pointed out that apart from this difference inthe scale, the atomic weights of nitrogen and carbon cannot nowbe the same as the masses N14 and C12 respectively determined bythe mass-spectrograph.Calculated values of these are given byS. M. Naud6.sRadioactive Constants and Other Data.A new value of the half-period of ionium, 1.9 x lo5 & 3% years,has been obtained by (Mme.) P. Curie and (Mme.) S. Cotelle z8;this is considerably higher than early values. Two values for thehalf-period of radium-D are also considerably higher than earliervalues. (Mme.) P. Curie and (Mme.) I. Curie29 obtained 19.5 yearsby direct measurements over a period of 16 years, and the latter 30obtained 23 years by an indirect method. The value 21 yearsis provisionally adopted. F. JoliotY3l by a slight modification ofJ. C. Jacobsen’s 32 method, obtained the half-period of radium&’’as 3 & 1.5 x 10-6 sec., confirming the order of the period previouslyobtained.A similar experiment with thorium-(?’ showed thatits period is much less than 10-6 sec. The half-periods of potassiumand rubidium have been determined by W. Muhlhoff 33 by countingthe number of p-particles emitted per g. per sec. in a Geiger andMuller sensitive particle counter. The half-period for potassiumis 1.5 x 1013 years, which is ten times greater than that estimatedby A. Holmes and R. W. Lawson 34 ; that of rubidium is 4.3 x lollST F. W. Aston, Nature, 1930,126, 953 ; A. von Grosse, 2. physikat. Chem.,1930, [B], 10, 395; A., 1931, 15.2 8 Compt. rend., 1930, 190, 1289; A., 976.29 J. Phys. Radium, 1929, [vi], 10, 385; A., 8.31 Compt. rend., 1930,191, 132; A., 1086.32 Phil. Mag., 1924, [V;], 47, 23; A , , 1924, ii, 142.33 Ann.Physik, 1930, [v], 7, 205; A., 1496.30 Ibid., p. 388; A., 8.31 An n. Reports, 1928, 25, 308SUB- ATOMIC PHENOMENA AND RADIOACTIVITY. 31 1years. On the assumption that the radioactivity of potassiumis due only to K41, the half-period of this isotope becomes 10l2 years,since K41 is approx. 6.7% of the total potassium (and not 5% asis generally assumed from the atomic-weight determination inignorance of the exact masses of K39 and K41). The new result forpotassium is important in connexion with J. Joly's theory of thesurface history of the earth, and has been briefly discussed by him.35Attempts to accelerate or influence the rate of decay of a radio-active substance by bombarding it with a-particles have neverbeen substantiated.H. Herszfinkiel and L. Wertenstein 36 havepointed out that this unexpected apparent stability may be dueto the fact that the experimenter may have been looking for aproduct which is in fact not produced. For example, the bombard-ment of uranium-I has been expected to produce the quick-changinguranium-X, due to loss of an a-particle, whereas on Lord Ruther-ford's theory36a it might instead produce uranium-I1 by loss ofan a-particle and two p-particles; since uranium11 is a productof long half-period the possible effect of the bombardment mighthave gone undetected. With thorium, however, the transformationwould produce the relatively quick-changing radiothorium, whichwould be much more easily detected. A milligram of thoriumoxide was bombarded by the a-particles from 28 millicuries ofradon for 6 days.No change of activity could be detected by amethod which was sensitive to 0.05 mg. of thorium. It was con-cluded that, if bombardment produced radiothorium from thorium,not more than one a-particle in 8 x lo6 could have been effective.G. I. Pokr~wski,~' however, found with weak sources of activematerial that the probability law for the number of particles ex-pelled was regularly deviated from, and concludes that the dis-integration of one atom is not independent of that of its neighbours.(Mme.) P. Curie 38 has given an account of experiments undertakenunder her direction to influence the values of the disintegrationconstants, and concludes that this cannot be done. She criticises 39adversely the work of L.B. Hogoia~lenski,~~ who claims that polon-ium disintegrates at different rates in different parts of Russia,the rate of decay being least abnormal in the capital.The round value for the constant &, the number of a-particlesemitted per g. of radium (without products) per sec. must now be35 Nature, 1930, 126, 953.36 Ibid., 1928, 122, 504; A., 1928, 1169.37 2. Physik, 1929, 58, 706; 1930,65, 133; A., 1930, 9, 1496.38 J. Phys. Radium, 1929, [vi], 10, 329; A., 1929, 1358.39 Ibid., p. 327; A., 1929, 1368.40 Ibid., p. 321; A., 1929, 1358; Nature, 1929, 123, 872; A., 1929, 737.36a See ref. 70312 RUSSELL :accepted as 3-70 x lolo. By means of the " total charge " method,H. J. J. Braddick and H. M. Cave 41 obtained the value 3.68 x 1O1Ort: 1%.With a new type of electrical counter due to H. Greina~her,~?P. A. B. Ward, C. E. Wynn-Williams, and H. M. C a ~ e 4 ~ obtainedthe value 3.66 x 1O1O & 0.5%. In both these sets of experimentsthe source employed was radium-C, and the value of the standardused was assumed to be accurately known. In the new elec-trical counter, the ionisation produced by a single a-particle islinearly amplified by triode valves, there being no ionisation bycollision. The final deflexion of the recording instrument is pro-portional to the initial ionisation. The ionisation due to p-particlesis too small to disturb the counting, which can be carried out accur-ately a t so high a rate as 500 particles per minute. This valueconfirms that of V.F. Hess and R. W. Lawson44 which has beenopposed for many years to that of H. Geiger and A. Werner45.The 3.7 x 1O1O value has now been got by the electric counting,the total charge, the production of heli~m,~6 the volume of radon,47and the heating-effect methods.48 The half-period of radiumcalculated from this datum is 1600 years.G. I . Harper and E. Salaman49 found the range of poloniuma-particles to be 3.87 cm. in standard air (15" C. and 760 mm.).J. L. Nickerson 50 found that of thorium a-particles to be 2-76 &- 0.1cm. The former is about 0.05 em. less than the generally acceptedvalue, but is in agreement with an earlier determination of (Mlle.)I. Curie 51 ; the latter value is 0.15 cm. less than the accepted value.The first authors also found that the ranges of thorium-C', radium-C', and thorium4 are all smaller than has previously been recorded.The deviation is greatest for thorium-C, and appears to be definitelyoutside of the range of experimental error.Important work on the initial velocities of the a-particles fromradium-C", thorium-C', and actinium-G has been done.G . C.41 Proc. Roy. SOC., 1928, [ A ] , 121, 367; A., 1929, 6.42 2. Physik, 1926, 36, 364; A., 1926, 563; ibid., 1927, 44, 319; A., 1927,43 Proc. Roy. SOC., 1929, [A], 125, 713; A , 7.O4 Sitzungsber. K. Akad. Wiss. Wien, 1918, [2A], 127, 405.4 5 2. Physik, 1924, 21, 187; A., 1924, ii, 226.O 7 L. Wertenstein, Phil. Mug., 1928, [vii], 6, 17; A., 1928, 932.915.(Sir) J. Dewar, P r o c .Roy. SOC., 1910, [A], 83, 404; A., 1910, ii, 376.E. Rutherford and H. Robinson, ibid., 1913, [vi], 25, 312; A.,1914, ii, 789; S. W. Watson, Proc. Rmj. SOC., 1928, [ A ] , 118, 318; A., i928.456.4 p Proc. Roy. SOC., 1930, [ A ] , 127, 175; A., 659.~.1 Ann. Reports, 1926, 23, 291.T r a n s . Nova Scotia I n s t . Sci., 1930, 17, 172 ; A., 659SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 313Laurence,52 continuing the work of G. H. Briggs,M has found theinitial velocities of the a-particles from radium-C, thorium-C’, andpolonium to be 1.709, 2.054, and 1.592 x lo9 cm. per sec., re-spectively, assuming Briggs’s value for radium-C’, vix., 1.923 X lo9cm. per sec. S. Rosenblum,M using a magnetic deviation method,found the initial velocities of the a-particles from radium-C’,thorium-C’, and radium-A to be 1.923, 2.054, and 1.695 x lo9 cm.per sec.respectively, assuming Briggs’s value for thorium-C, v ~ z . ,1.701 x loQ cm. per sec. The three sets of values are in excellentagreement. S. Rosenblum 55 has also made the remarkable observ-ation that the initial velocity of the ordinary a-particles fromsome radio-elements is not a constant. He examined the finestructure of the a-particles from thorium-C (range 4.8 cm.) by theDanysz focusing method employed in the examination of p-particlespectra. The particles were bent in a circle of about 25 cm. diameterby means of a field of about 36,000 gauss. He found that fourfaint groups accompany the main group of particles. Their veloci-ties were 1.003, 0.975, 0.962, and 0.964, that of the main groupbeing 1, and their relative intensities were 30, 3, 2, and 0.5%respectively of that of the main group.He obtained no certainevidence of additional groups of particles from radium-A , polonium,radium-C‘, or thorium-C’. This new method of attack is clearlyone of interest and importance. Another method of analysis ofgroups of a-particles has been devised by Lord Rutherford, F. A. B.Ward, and C. E. Wynn-Willisms.56 By using a double ionisationchamber with a Greinacher counter,42 they have succeeded in count-ing, not simply the total number of particles exceeding a givenrange, but the number having ranges between x and x + dx, wheredx is a few millimetres only. With this apparatus they haveinvestigated the straggling curves of the 8-6-cm. or-particles fromthorium-C’, the 7.0-cm.particles from radium-C‘, aid the 3.9-cm.particles from polonium. A11 these, in confirmation of S. Rosen-blum’s results, appear to be homogeneous groups of or-particles.They have shown also that the 5-5-cm. particles from actinium-Care in two well-marked groups of ranges 5.51 and 5.09 cm. in theratio of 100: 22. They found for the first time the short-rangeor-particles postulated by tlhe group-displacement law and theGeiger-Nuttall relation, emitted in the dual disintegration of radium-C. There are two sets with ranges of 4.14 and 3-95 cm., assuming52 Proc. Roy. Soc., 1929, [ A ] , 122, 643; A , , 1929, 370.53 Ibid., 1928, [ A ] , 118, 549; A., 1928, 569.54 Compt.rend., 1930, 190, 1124; A., 837.5 5 Ibid., 1929, 188, 1401, 1549; A., 738; ibid., 1930, 190, 19.66 Proc. Roy. SOC., 1930, [AJ, 129, 211; A., 1338314 RUSSELL :the range of the a-particles of polonium to be 3.92 cm. Theirrelative intensities are 3 to 1. The intensity of the two groupstogether is just over 1 in 4000 of the main 7-cm. group of par-ticles from radium-C’. The branching a t radium must now betaken as 4000 to 1 in the directions radium-C‘ and radium-C”respectively, a value in good agreement with those deduced by K.Fajans 57 (3000 : 1)’ and by (Frl.) E. Albrecht 58 (4000 : l), fromthe intensity of the P-particles from radium-C. The experimentalvalues of the ranges are in agreement with that deduced from theGeiger-Nuttall relation (3.9 cm.).Finally, the 4-8-cm. cc-particlesfrom thorium-C were found to be complex, in qualitative agreementwith S. Rosenblum’s work. It is probably significant that thoseproducts, radium-C, thorium-C, and actinium-C, which give com-plex a-particles, are all of odd atomic number, and it will be interest-ing to see whether protoactinium, when it is examined, conformsto this. This heterogeneity is not explained by earlier theories ofthe structure of radioactive nuclei, but an explanation of i t hassince been put forward by G. gar no^.^^New data have been obtained of the relative abundance andranges of the long-range particles from radium-C’ and thorium-C’.Using a special form of Wilson expansion apparatus, R. R. Nimmoand N.Feather 6O find that the long-range particles of thorium-C”fall into two principal groups of ranges 9-82 and 11-62 cm. instandard air, the range of the ordinary a-particle being taken as 8-54cm. The ratio of the abundance 1 : 5-1 differs considerably fromthat obtained by (Frl.) L. Meitner and K. Freitag (1 : 2.8). Afew tracks indicating a-particles of range 12.5 cm. were observed,but the number was too small to allow definite conclusions to bedrawn. The conclusions for radium-C’ were less definite. Thereis a well-defined group with a range of 9.08 cm., but other particleshave ranges fairly well distributed between 7-5 and 12 cm. Thesemay be regarded as groups with mean ranges of 8.0, 11.0, andpossibly also 10.0 cm. The results, however, make it quite clearthat radium-C’ emits more than the two long ranges found in theoriginal scintillation experiments of Rutherford and J.Chad-wick.G2 On the other hand, K. Philipp and K. D ~ n a t , ~ ~ using alsoWilson’s cloud method, find that for every lo6 normal a-particlesfrom radium-C’ there are 29 with a range of 9.2 cm., 4 of 11.0 cm,,5’ Physikal. Z . , 1912, 13, 699; A., 1912, ii, 824.5 8 Sitzungsber. K . Akad. Wiss. Wien, 1919, [2 A ] , 128,925; A., 1921, ii, 675.5s Nature, 1930, 126, 397; A., 1339.6o Proc. Roy. SOC., 1929, [A], 122, 668; A., 1929, 371.6 1 2. Physik, 1926,37,481; A., 1926, 772.62 Phil. Mag., 1924, [vi], 48, 509; A., 1924, ii, 814.63 2. Phy&k, 1929,52, 769; A., 1929,371SUB-ATOMIC PHENOMENA AXD RADIOACTMTY. 315and 0.5 with a range greater still.These data confirm thescintillation experiments. The origin of the long-range particlesis discussed by Rutherford, J. Chadwick, and C. D. Ellis and, forthorium-C’, by E. Stahe1.64H. Zeigert 65 has determined the number of ions produced per=-particle from uranium-I, uranium-11, and radium by detectingsingle a-particles with a very sensitive electrometer and measuringdirectly the total ionisation in air due to each. The values 1.16 x lo5,1-29 x lo5, and 1.36 x lo5 are in good accord with the valuescalculated from the ranges of these elements based on the range ofradium-C‘ and the number of ions it produces.The Actinium Problem.In a mass-spectrograph investigation of uranium-lead tetra-methyl prepared from broggerite, F.W. Aston 66 found the isotopesPb206, Pb207, and Pb208 in the abundance of 86.8, 9.3, and 3.9%respectively. Pb207 in this proportion cannot be due to ordinarylead, and it is concluded that it is the end product of the actiniumseries. This experiment brilliantly establishes a suggestion, manyyears old, based partly on atomic-weight determinations and partlyon the half -periods of disintegration products. Calculated fromthis result, the atomic weight of protoactinium becomes 231 or,if allowance is made for the packing effect by extrapolating thepacking-fraction curve, 231.08. On the basis of this work, Ruther-ford G7 supposes that an isotope of uranium-I, actino-uranium, ofmass 235, is the head of the actinium series proceeding to proto-actinium via uranium- Y .From the half-value period of uranium-I,he calculates the period of actino-uranium to be 4.2 x lo8 years,and deduces that, if the production of uranium in the earth ceasedas soon as the earth separated from the sun (as is likely), the earthcannot be older than 3.4 x lo9 years. Also if the age of the sunbe taken as about 7 x 10l2 years (Sir J. Jeans’s estimate), it followsthat uranium and similar elements were being formed in the sunas late as 4 x lo9 years ago and that probably the process stillcontinues. Although there is agreement that the atomic weightof actinium42 must be accepted as 207, the other points raisedhave received criticism. C. N. Fenner and C. S. Piggot,68 from astudy of the composition and age of the broggerite from which thelead was obtained, regard Aston’s determination of the abundance84 ‘‘ Radiations from Radioactive Substances,” p.94 ; E. Stahel, 2. Physik,66 8. Physik, 1928,46,668; A., 1928,466.86 Nature, 1929, 123, 313; A., 1929, 370.6’ Ibid., p. 313; A., 1929, 373.1930, 63, 149; A., 1233.68 Ibid., p. 793; A., 1929, 620316 RUSSELL :of Pb208 as about 50% too high, since, on his figures, the uranium-thorium equivalence factor (0.38) comes out at 0.57. By inference,the abundance of Pb207 is also 50% too high. A. Holmes G9 hasdirected attention to another line of evidence, from which it canbe inferred that the half-periods of uranium-I and actino-uraniumare probably nearly equal. It has been generally accepted thatthe percentages of atoms disintegrating via protoactinium andradium from uranium are about 3 and 97 respectively. If bothuranium-I and actino-uranium disintegrate a t about equal rates,these should be the percentages of Pb207 and Pb206 in pre-Cambrianminerals. But if Rutherford is right, the percentage of Pb207 shouldbe definitely higher.From composition and atomic-weight dataof four unaltered minerals, Holmes calculates the percentage ofPb207 to be between 2.5 and 3.3. He concludes that Aston's estimateof the abundance of Pb207 in broggerite is too high to be represent-ative, that Rutherford's resulting estimate for the half-period ofactino-uranium is too low, and that, indeed, the half-periods ofuranium-I and actino-uranium are probably of the same order.This agreement in the proportion of corresponding actinium anduranium members at the beginning and a t the end of their seriesis remarkable, but it does not include all the evidence.There areatomic-weight determinations of uranium-lead which suggest thatPb207 is totally absent from it 69, 70. Again, J. E. Wildish 71 foundthat the number of atoms of protoactinium disintegrating pcr 100atoms of uranium varied from 1.47 to 5-16 in different minerals.The lower values could, no doubt, be explained by alteration of themineral, but not the upper. It is difficult to see also how F. W.Aston's result for Pb207 could be cut down to 3 or even 5yo. Also,A. IF. Kovarik,'2 from a survey of evidence not dissimilar from thatconsidered by A.Holmes, considers that actino-uranium has ahalf-period of 2.7 x los years, a value even lower than Ruther-ford's. Initially, he thinks, there has been a definite amount inproportion to the uranium-I, but the relative proportion of thetwo isotopes has decreased with the age of the mineral. The periodof actino-uranium cannot, therefore, be regarded as settled so longas this conflict of evidence and opinion remafiis. The mass of thisisotope must meanwhile be taken as 235, as suggested by LordRutherford. The determination of the atomic weight of proto-actinium (the result of which has not yet been published) or of theconstitution of uranium by the mass-spectrograph method shouldi o Ann. Reports, 1928, 25, 306.7 1 J . Amer. Chem. SOC., 1930, 52, 163; A ., 308.72 Science, 1930, 72, 122; A., 1495; Amer. J. Sci., 1930, [v], 20, 393; A.,Nature, 1030, 126, 348; A., 1339.1552SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 317settle this point. But, as it has not been settled, it may be said.that it is exceptional that ordinary uranium should have an isotopeof odd mass like 235, possibly in so great an abundance (byweight) as 3% (on A. Holmes’s evidence) when it apparentlycontains no mass of 236 or 240, and when the abundance of uranium-11, of mass 234, is negligible. A. S. Russell V3 has previously givenreasons for regarding 233 as a more likely mass for protoactiniumthan 231. This appeared to require a mass for actinium4 of 209which is certainly wrong, but only if no other massive particle thanthe a-particle is expelled in the series.From general knowledgeof the masses and stabilities of isotopes both of radioactive andinactive elements, it seems simplest to regard actino-uranium ashaving a mass of 238, protoactinium one of 233, and actinium-0one of 207. An experimental value of protoactinium of 233 wouldsupport this view with its consequence that the a-particle is notthe only massive particle expelled; a value of 231 would favourthe much simpler view.The actinium problem is also discussed by G. E l ~ e n , ~ ~ A. vonG r ~ s s e , ~ ~ and T. R. Wilkh1s.7~ The first author supports a view,now out of favour, that the atomic weight of actino-uranium isgreater than 238; and the last worker is in agreement with LordRutherford in regarding its period as less than that of uranium-I.Wave-mechanics and Radimctive Disintegration.A simple explanation of radioactive disintegration and a solutionof the apparent conflict between the radioactive data and the resultsof scattering has been put forward simultaneously by G.Gamow 77and by It. W. Gurney and E. U. Condon 78 on a basis of the newwave-mechanics. It deals with the points such as the exponentiallaw of transformation and the Geiger-Nuttall relation which were leftuntouched by Rutherford’s theory 79 of the structure of radioactivenuclei. The nucleus is pictured as a tiny enclosure surrounded by apotential hill enclosing an a-particle (represented by a standing wave)of which the energy is less than the potential energy a t the top ofthe barrier.On the classical mechanics, the a-particle inside thenucleus cannot surmount the barrier, but, on wave mechanics, i t73 Nature, 1927, 120, 402 ; A., 1927, 1002.74 2. anorg. Chem., 1929,180, 304; A., 1929, 737.75 Ibid., 1930, 186, 38; A., 515.76 Physical Rev., 1927, [ii], 29, 352; A., 1928, 1302.7 7 2. P h p i k , 1928, 51, 204; A., 1929, 7; ibid., 1929, 53, 601; A., 1929,7 8 Nature, 1928, 122, 439; Physical Rev., 1929, [ii], 33, 127; A., 1929, 374.7g Phil. Mag., 1927, [vi], 4, 680; A,, 1927, 1002; Ann. Reports, 1928, 25,484.309318 RUSSELL :will have a finite chance of escape which will be the greater thegreater its energy, the thinner the barrier, and the smaller theheight of the barrier (see these Reports, p.27). There is thus arelation between the energy of the cc-particle and the disintegrationconstant of the nucleus. Gamow expresses this as log 1 = E + bE,where h is the disintegration constant, 7c a constant, b a constantfor all radioactive nuclei, and E the energy of the or-particle. Thiscorresponds approximately to the Geiger-Nuttall relation, and thecalculated value of b corresponds well with the experimental value.Log 1, it is seen, increases less rapidly than E, a relation which isconsistent with the fact that the half-period of a quick-changingproduct like radium-C’ is much less than is anticipated from theGeiger-Nuttall relation. The theory has been developed by G.Gamow and F. G. Houtermans.so They show how the disintegrationconstants of all a-particle elements can be calculated from thenuclear charge and the velocity of the or-particle.The calculatedvalues are in very satisfactory agreement with the experimental,in view of the approximations made in the calculations. Thetheory, though still in a tentative form, is most promising. Itmay be added that it demands such potential barriers round radio-active nuclei as not to be penetrated by any a-particles a t presentavailable, and this is in agreement with experimental work.ArtiJicial Disintegration by or-Particles.between the two series of investigations onthe artificial disintegration of the light elements carried out a tCambridge and a t Vienna have still to be satisfactorily explained.As these relate to the detection of scintillations, it is obvious thatsome of the doubtful points would be cleared up by obtainingphotographs of the disintegration in a Wilson cloud chamber orby using an electrical method of detecting the particles of disin-tegration. First steps in both these directions have already beentaken and, i t is hoped, will lead ultimately to a solution of thedifficulty.While a general description of the phenomena of disintegrationcan be given in terms of the picture of the potential field betweenan or-particle and the nucleus of a light atom obtained from thescattering experiments, there are still a few outstanding difficulties.The data suggest that penetration of the a-particle into the alum-inium nucleus and capture, for instance, would be impossible forvelocities of or-particles less than 2 x lo9 cm.per sec., while actuallythe aluminium nucleus is disintegrated by particles of much smaller2. Physik, 1928, 52, 496; A., 1929, 233.The divergences81 Ann. Reports, 1926, $23, 285SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 319velocity. An explanation of this, impossible on classical mechanics,is given by G. Gamow 77 and by R. W. Gurney and E. U. Condon 78 onthe basis of wave-mechanics. The agreement between Gamow’scalculations of the chance of penetration and the experimentalnumbers of emitted protons is sufficient to show that, for elementslike nitrogen or aluminium, the probability that a capture of thea-particle results in disintegration is fairly high. Gamow 82 has alsocalculated the probability of disintegration of light elements whenbombarded by or-particles from radium-C’ and from polonium, andshown that the chance of Penetration decreases very rapidly asatomic number increases and is small for numbers greater than 20.The possibility, therefore, that eventually all elements will bebrought into line with the lighter ones in this respect is exceedinglyremote.The bombardment of atoms of aluminium by or-particles of range7 cm.from radium-(B + C ) has been shown by Rutherford andJ. Chadwick 83 to release protons with a definite minimum rangein air of about 10-12 cm. These experiments suggest that theprotons liberated in disintegration possess a certain minimumenergy in addition (as had been shown earlier) to a maximum energy.This energy of release for aluminium is roughly of the same mag-nitude as that corresponding with the potential of LL proton in thefield round the aluminium nucleus.P. W.Aston’s 84 observation that the packing fraction is higherfor light elements of odd atomic number than for those of even,is correlated 85 with the observation that protons emitted fromelements of odd atomic number have greater maximum energiesin general than those emitted from elements of even atomic number.For if the disintegration consists of the capture of an or-particleand the emission of a proton, the odd-numbered element bombardedis changed to an even-numbered element and vice versa. I n theformer case mass is lost, in the latter mass is gained.The loss willappear as an excess of kinetic energy associated with the emittedproton above that which can exist in the latter case. In this argu-ment, the gain in mass of the proton on its release from the nuclearbinding and the kinetic energy of the incident a-particle have notbeen taken into account. These energies, however, nearly balance ;the gain in mass in the former case, 0.00724, being close to the massequivalent of the kinetic energy of the a-particle (of radium-C‘),vix., 0.0082. But the information at present available is not suffi-82 Nature, 1928, 122, 806; A,, 1929, 6; 2. Physik, 1928, 52, 610.83 Proc. Camb. Phil. Soc., 1929, 25, 186.86 J. Chadwick, Proc. Roy. ~ o c . , 1929, [A], 123, 373; A., 1929, 622.Ann. Reports, 1928, 25, 303320 RUSSELL :ciently accurate to test this point more than qualitatively.Forquantitative agreement, the atomic masses of the lighter elementsmust be known with a greater degree of accuracy than a t present,and the motions of the a-particle and the residual nucleus afterdisintegration must also be accurately known. At present theavailable evidence is against quantitative agreement.86The new wave-mechanics has also been applied to explain arti-ficial disintegration by a-particles. 87 It has been suggested byJ. Chadwick and G. Gamow,88 partly on general grounds and partlyon the basis of unpublished experiments a t Cambridge, that theprocess of disintegration of a nucleus by collision with an a-particlemay occur in two ways : (a) by the capture of the a-particle bythe atomic nucleus followed by the emission of a proton, and (6)(a new suggestion) by the ejection of a proton without the captureof the a-particle.In ( a ) the a-particle must penetrate the nucleus;in ( b ) it need not, collisions being responsible for the disintegration.It is deduced that there may be more than one level at which thea-particle may remain after capture and that there will be protonsof “ the line spectrum ” and protons of “ the continuous spectrum.”The former are expected t o be emitted nearly uniformly in alldirections, the latter will be emitted mainly in the direction of thecolliding a-particles. Experimental evidence for the presence ofgroups of different ranges in the disintegration protons has alreadybeenobtained by different experimenter^.^^ When boron, for example,is bombarded by the a-particles of polonium, three groups of protonshave been found with ranges in air of 16, 32, and 76 em.The firstis identified as a “continuous spectrum,” and the other two as“ line spectra.” From energy considerations it appears that B10is the isotope attacked. The continuous spectrum of protons isinterpreted as corresponding with the formation of the nucleus ofBe9 and both the line groups with that of (213. The disintegrationof aluminium by the a-particles from polonium shows similarfeatures. Although such experimental results are still at a tent-ative stage, it is evident that the phenomenon of artificial disin-tegration promises to reveal the intimate structure of the nucleiof the lighter elements in a way not previously thoughtpossible.86 “ Radiations from Radioactive Substances,” p.307.8 7 Ibid., p. 672.Nature, 1930, 126, 54; A., 1085.W. Bothe and H. Franz, Naturwiss., 1928,16, 204; A., 1928, 1302; 2.Physik, 1928, 49, 1; 51, 613; A., 1929, 230; H. Franz, ibid., 1930, 63, 370;A., 1338; Physikal. Z., 1929, 30, 810; A., 130; W. Bothe, 2. Physik, 1928,51, 613; A., 1939, 230; ibid.. 1930, 63, 381; A., 1338; H. Pose, ibid., 64,1 ; A.,1232; Physika2. Z., 1929, 30, 780SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 321It is interesting to note that the two synthesised nuclei, 0 1 7 andCIS, have been discovered from an examination of band spectra.90The Smtterileg of u-Particles in Helium.An interesting contribution to this subject has been made byJ. Chadwi~k.~1 The problem of the collision of two particles whichact upon each other with forces varying as the inverse square ofthe distance between them has been solved exactly on the basisof the new wave-mechanics, and the solution is the same as thatgiven by the classical mechanics.This agreement, however, asN. F. Mott 92 has pointed out, depends upon the dissimilarity ofthe colliding particles; if the particles are identical, the scatteringlaws given by the wave-mechanics will be very different from thoseof classical theory. a-Particles from polonium were scatteredthrough angles between 40" and 50". The experimental resultswere found to be close to those predicted by the quantum theoryand markedly different from those predicted on the classical theory.The calculations of Mott are therefore verified, and with them theassumption on which they rest, vix., that it is impossible to dis-tinguish one helium nucleus from another.In other words, thehelium nucleus has no spin or vector quantity associated with it.Its field of force is perfectly spherical. The observations alsoindicate that, as the distance between the colliding u-particle andnucleus is decreased, the observed scattering rises slightly abovethat calculated from the quantum theory, then falls, and finallyrises rapidly again. The initial rise and fall may be due to a truechange in the law of force between the particles, but the asymmetryshown at small distances of collision can be due only to a distortionof the structure of the particles.The Age of Iron Meteorites.F.Paneth, W. D. Urry, and W. Koeckg3 have determined theage of 27 different specimens of iron meteorites by ascertainingthe ratio of helium to uranium. The helium was estimated byPaneth's improved method, and the uranium by a radium deter-mination. The ages ca1cula)ted from the experimental data areall less than the age of the earth, and the results agree with theview that the meteorites originated in the solar system. Earlierdeterminations of age by the helium method were shown to be toolow owing to the incomplete evolution of the gas by the methodsemployed.90 Supra, p. 306.92 Ibid., 126,259 ; A., 369.93 Nature, 1930,125,490; A., 871; 2.EEe&rochenz., 1930,38, 727; A , , 1398.91 Proc. Roy. SOC., 1930, [A], 128, 114; A., 1085.REP.-VOL. XXVII. 322 RUSSELL :The Cosmic Rays.Hitherto the penetrating radiation usually knowii as the cosmicrays has been regarded as electromagnetic in character and comingfrom outer space.94 W. Rothe and W. K~lhorster,~~ however, havedone experiments which suggest that i t is corpuscular. Theyarranged two Geiger counters of special design a small distanceapart inside a protecting shield of iron and detected the same p-particle inside each. They concluded from their experiments thatthe primary penetrating radiations are very high-speed P-particles.The number of these is very small, about 1/100 per sq. cm. per sec.,but their individual energies must be very high.E. Regener,g6on the other hand, has measured the absorption coefficient of theradiation in water to such great depths that it is seems very unlikelyit could be corpuscular in character. He made measurements a tdistances from 32 to 231 metres, obtaining seven readings, belowthe level of Lake Constance. The maximum distance he attainedto is about three times greater than the region explored by R. A.Millikan and G. H. Cameron.94 A single absorption coefficient ofvalue about 0.018 per metre of water was found to explain theabsorption a t depths greater than 80 metres, a value which impliesa penetrating power greater than any of those found by Millikanand Cameron. A. Corlin 97 has made a critical examination of thesystematic measurements to determine whether the penetratingradiation is in any way directional. He concludes that the intensityof it is periodic.It is relatively high at 3 p.m. and possibly between5 and 8 a.m. and low at 10 a.m. As V. F. Hess and 0. Mathias 98did not find such periodic fluctuations with their electroscopecovered with 7 cm. of iron, it was concluded that only the softercomponents follow sidereal time. Fluctuations, however, havebeen also found by E. RegenergG at a depth of 78 metres belowLake Constance, so the whole radiation may show this phenomenon.The absorption of the radiation has been studied in media otherthan water by K. Buttner,99 E. Steinke,l G. and L.Myssovski and L. T ~ v i m . ~ The importance of analysing theahsorption curves into two, representing the primary and theg4 Ann.Beports, 1928, %, 321.9 5 2. Physik, 1929, 56, 751 ; Nature, 1929,123, 638; A., 1929, 621.96 Naturwiss., 1929, 11, 183.97 2. Physik, 1928, 50, 808; Nature, 1930, 126, 57.89 Sitzungsber. Akad. Wiss. Wien, 1928, [2 A], 137, 327.99 2. ffeophysik, 1927, 3, 161.1 2. Physik, 1927, 42, 570; 1928, 48, 647.2 Physikal. Z . , 1925, 26, 669; Ann. Physik, 1927, [iv], 82, 413; A., 1927,3 Z. Physik, 1928, 50, 2 7 3 ; A., 1938, 1070.289SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 323degraded radiation, has been emphasised by L. H. Gray4 and H.Kuhlenkampff - 5The Fine-structure Constant, the Proton, and the Electron.(Sir) A. S. Eddington 6 has called attention to the possibility thatthe reciprocal of the “ fine-structure constant,” 2xe2/hc, which isknown to be dimensionless, is integral and equal to 137.Thestarting point of this work is the observation that the interactionof electrons can now be described by two principles : Coulomb’selectrostatic forces and Pauli’s exclusion principle. If these areregarded as two aspects of the same feature of our world, theremust necessarily be a theoretical connexion between the two con-stants e2 and hc/2x which they respectively introduce. His firstview was that the ratio should be simply the number of symmetricalterms in an array of 16 rows and 16 columns, which is 136. Sincethe experimental value of the ratio is 137.29 0.11, the theorysuggested that possibly the value of e was about 0.5% too small,a suggestion that did not escape comment from those who upheldR.A. Millikan’s 8 value as against one determined by a new X-raymethod due to E. Backling which is approximately right for thetheory. Eddington discovered later,10 however, that in additionto the 136 symmetrical degrees of freedom there was one character-istic of a pair of electrons which, unlike the others, has no analoguein the theory of a single electron, namely, an alteration of the properdistance between them ; thie degree of freedom had been overlookedthrough his not recognising its distinctness from the others. Themost probable values of the e,, h, c, N , and other fundamental con-stants have been discussed by R. T. Birge l1 and R. A.Millikan,8and given as e = 4-770 & 0.005 x 10-10 abs.e.s.u., h = 6.547 &0.011 x erg./sec., c = 2-99796 & 0.00004 x 1O1O cm. sec.-l,and N = 6.064 & 0.006 x 1023. From an examination of theevidence available, they conclude that the ratio hcl2xe2 cannotbe an integer. The value of Eddington’s suggestion (which neces-sarily requires an integral value for the ratio) thus depends uponthe accuracy with which e can be determined, since the value forProc. Roy. SOC., 1929, [ A ] , 122, 647; A,, 1929, 372.Sitzungsber. Akad. Wiss. Wien, 1928, [2 A ] , 137, 327.Proc. Roy. Soc., 1929, [A], 122, 358; A., 1929, 231.R. T. Birge, Nature, 1929, 123, 318; A., 1929, 368; E. BLicklin, ibid.,Physical Rev., 1930, [ii], 35, 1231; A., 977.Dim., Uppaala, 1927.p.409; A., 1929, 369; J. H. J. Poole, ibid., p. 530; A , , 1929, 484.l o Nature, 1929, 124, 840; A., 10; Proc. Roy. SOC., 1930, [ A ] , 126, 696;11 PhyRical Rev., Suppl., 1929, 1, 1.A., 618324 RUSSELL :h happens to be also dependent upon that of e. The new X-raymethod of E. Backlin promises a very accurate value, but his owndetermination of e by it is not regarded as very accurate. A. P. R.Wadlund,12 however, using this method, has obtained a few valuesthe mean of which, 4.774 & 0.007 x 10-10, is close to Millikan's.The value 4.775 x 1O-lo, which is not outside the limits of thesedeterminations, gives with the present accepted values of the otherconstants the value required by Eddington's theory. It may bepointed out that a form of this ratio had earlier been employed byG.N. Lewis and E. Q. AdamsI3 in their theory of absolute units.There it was regarded as being equal t o 8 x ( 8 ~ ~ / 1 5 ) ~ ' ~ , the numericalvalue of which is 137.35.The ratio, M/m, of the masses of the proton and the electron isanother dimensionless constant which has attracted attention.J. Perles l4 has found that this ratio may be expressed as hc(n - l)/e2.This gives a value 1847.4, identical with the best experimentalvalue, vix., 1847 & 2. R. Fiirth l5 has shown that the value ofthe ratio follows from general quantum considerations, and givesa formula which leads to a value of 1836. E. E. WitmerI6 haspointed out that it is very nearly the square of half the atomicnumber of the heaviest known inert gas (i-e., l849), an agreementwhich it is difficult to regard as more than a coincidence.Heexpresses the relation between the masses and the atomic numbersof helium and hydrogen as MHe/ME= (ZHe/ZH)2[l/(l + a)], whereM represents mass and Z atomic number, and a is 2xe2/hc. Thevalue of hc/2xe2, calculated from this equation, i.e., 138.1, is closeto the experimental value, 137.29.A more developed theory on this subject has been put forwardby (Sir) A. S. Eddingt0n.l' He proposes a theory of mass in whichthe representation in a microscopic space-time increases the naturalmass of the proton in the ratio 1361410 and diminishes that of theelectron in an equal ratio, This gives M/m = 1362/10 = 1849.6which is close to the experimental value.He also shows that ifelectrons and protons form a perfectly rigid system, the mass M rela-tive to that of its constituents is reduced in the ratio 136/137.This ratio agrees approximately with the reduction of the mass ofa proton when it enters into a nucleus. Its reciprocal, in fact(1.00735), is intermediate between the atomic weight of hydrogen12 Proc. Nat. Acad. Sci., 1925, 14, 588; Physical Rev., 1928, [ii], 32, 841;13 Ibid., 1914, [ii], 3, 92. l4 Naturwiss., 1928, 16, 1094.1 5 Ibid., 1929,17, 688, 728; A., 1929, 1123, 1209.1 6 Nature, 1929, 124, 180; A., 1929, 973.1 7 PTOC. C a d . Phil. rSoc., 1931, (in press).A., 1029, 227SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 325expressed in terms of He == 4 (1,00724) and 0 = 16 (140778) :better agreement than this cannot be expected on the assumptionsmade.A novel theory of protons and electrons has been proposed byP. A. M. Dirac.18 The ‘relativity quantum theory of an electronleads to a wave-equation which has solutions corresponding withnegative energies, the energy of an electron being regarded aspositive. If a negative-energy electron is regarded as a proton,several paradoxes arise. This di6culty is escaped by postulatingonly one fundamental particle, the electron. The stable statesof an electron are those of lowest energy. In consequence, allelectrons would tend to fall into the negative-energy states withemission of radiation were it not for Pauli’s exclusion principle,which prevents more than one electron going into any one state.Dirac, however, assumes that there are so many electrons in theworld that all the states of negative energy except perhaps a feware occupied, and supposes that the infinite number of electronspresent in any volume will remain undetectable if they are uniformlydistributed. Only a few “holes” or missing states of negativeenergy consequently remain amenable to observation, and theseholes, these things of positive energy, are identified with the protons.Various obvious difficulties which follow this conception are dealtwith in the theory. One, however, remains, viz., the’difficulty ofexplaining why the proton and the electron differ so widely in mass.According to this theory, they should be of equal mass or, by con-sidering interaction, of slightly different masses. J. R. Oppen-heimer l9 attempts to surmount some of the difficulties in the fore-going theory by supposing that all, and not merely nearly all, ofthe states of negative energy are occupied, so that a positive-energyelectron can never make a transition to a negative-energy state.This implies, however, that there are no holes which can be calledprotons, so that the proton has to be regarded as a particle inde-pendent of the electron. In consequence, the proton will have itsown negative-energy states which must be assumed to be all occupied.The independence of the proton and electron allows them to haveany relative mass they require, but it is inconsistent with thepossibility that a proton can annihilate an electron.A. S. RUSSELL.la Proc. Roy. SOC., 1930, [ A ] , 126, 360; A., 271. Nature, 1930, 126, 606.lD Physical Rev., 1930, [ii], 35, 461, 939; A., 660, 836

ISSN:0365-6217    

DOI:10.1039/AR9302700305

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

THE ELECTRICAL CONDUCTIVITY OF SOLUTIONS.FOR nearly forty years the Arrhenius theory of ionic dissociationwas the centre of controversy among electro-chemists. While itsmain principle, that the variation of the equivalent conductivityof a, solution depends solely on a variation in the proportion ofionised molecules, was supported by the behaviour of weak electro-lytes, it was shown to be incompatible with the behaviour of strongelectrolytes, and the discrepancies between theory and fact led in1907 to G. N. Lewis’s empirical conception of the activity co-efficient to replace the Arrhenius degree of dissociation, a = &/Ao.From time to time a number of investigators (J. J. van Laar,2W. S~therland,~ N. Bjerrum) and others) suggested that strongelectrolytes were completely ionised, and that the variations oftheir properties with dilution might be due to the electrical fofcesbetween the ions.in 1912 was, however, the firstto see that the solution of the problem was to be found in theeffect of the Coulomb forces in preventing the random distributionof the ions.devised a relatively simple mathematical treatment of the problemyielding a general solution, which they applied to the theory of theconductivity of an electrolyte. By finding methods of calculatingthe activity coefficient of an electrolyte and the change in its elec-trical conductivity with dilution from the physical properties ofthe solvent and the concentration, they opened up a new phase ofdevelopment in the study of electrolytic solutions. They made itpossible to calculate the behaviour in any solvent of an idealcompletely dissociated electrolyte, if it were dependent solely onthe physical properties of the solvent and of the ions, therebyenabling us to see to what extent a particular electrolyte deviatesfrom ideal behaviour and how far chemical influences come intoS.R. MilnerIt was not until 1923 that P. Debye and E. Huckelplay.The report deals chiefly with the following topics :(1) A sketch of the Debye-Huckel-Onsager theory.(2) The verification of this theory by conductivity measure-ments at high frequencies.(3) Recent work on conductivity in water and non-aqueoussolvents, and a comparison of the results with the Debye-Huckel-Onsager theory.(4) Ionic mobilities in various solvents.(5) Solvation of ions and its relation to ionic associationTHE ELECTRICAL CONDUCTIVITY OF SOLUTIONS.327The main object of the report is to show how far the Debye-Huckel theory is in accord with the results of conductivity measure-ments, and as the theory can only be strictly true in dilute solutions,experimental work in the range 0.002N to 0.0001N has been chieflyconsidered. Also, as there has been no systematic work on multi-valent ions in non-aqueous solvents, consideration has been prac-tically limited to uni-univalent electrolytes.The report deals chiefly with researches carried out between1920 and 1930, and, apart from the earlier work in water, greaterreliance can be placed on the results of more recent work owing tothe great improvements in technique.It is obviously impossibleto include references to all the researches which have been done inthis field during the last decade, but an attempt has been made inthe section dealing with ionic mobilities and transport numbers toindicate the existence of serious discrepancies and gaps. In spiteof the many additions that have been made to our knowledge ofnon-aqueous solutions in recent years, much still remains to be donein this field before we have a picture of the properties of electrolyticsolutions which is in any way complete or definitely established.The most important recent compilation of conductivity data iscontained in P. Walden’s three volumes, “ Das Leitvermogen derLasungen.” Monographs dealing with different aspects of theproblem have been published by C.A. Kraus,8 R. lor en^,^ H.Ulich,l0 H. Remy,ll and C. W. Davies.12 There are also theReport of the Discussion of Strong Electrolytes held by the FaradaySociety in Oxford in 1927,13 and separate papers dealing with thegeneral position by H. Ulich and E. J. Birr,14 N. Bjerrum,15 andR. Schingnitz.16The Theory of Debye and Huckel.The Ionic Atmosphere.-The basis of the Debye-Hiickel theoryof the properties of electrolytic solutions is the idea of an ionicatmosphere suggested by S. R. Milner,5 who pointed out that thedistribution of the ions of an electrolyte round a given ion wouldnot be random as is the distribution round a fixed point in thesolution. Owing to the Coulomb forces there will be an excess ofpositive ions in the neighbourhood of a negative ion and vice versa.The density of charge in a small element of volume at a certaindistance from the central ion will fluctuate, and the density ofcharge at this point is taken as the mean density averaged over aninterval of time.Thus on a time average each ion can be con-sidered as surrounded by a spherical ionic atmosphere, the densityof which will decrease with the distance from the ion. The ionicatmosphere will affect the electrical potential of tjhe surface of th328 MURRAY-RUST, GATTY, MACFAELANE, AND fIARTLXY :central ion, and, by taking into account the changes of potentialwith dilution, Milner waa able to calculate the freezing-point depres-sion of an electrolyte at different dilutions, assuming that it wascompletely dissociated.Debye and Huckel greatly simplified themathematical treatment of the problem by applying Poisson'sequation to the distribution of charge in the ionic atmosphere.Since a solution as a whole is electrically neutral, the total chargeof the ionic atmosphere is equal and opposite to that of the centralion, and its distribution will vary with the nature and concentrationof the electrolyte and with the dielectric constant of the solvent.Debye and Hiickel found the following expression for F, the meanelectric potential at a point ion due to its atmosphere :(1) D * - . * - *ZEK - + = - -where-& is the charge on an electron, x the vrtlency of the ion withthe sign of the charge on the ion, D the dielectric constant of thepure solvent, and 1 / ~ is a length which is characteristic of the rateof decrease of the density of the atmosphere with the distancefrom the central ion.Its value for binary electrolytes is given by1.985 x 10-loJ~Tcons. . . . ( 2 ) 1/K =2where T is the absolute temperature and c the concentration inmols. per litre. The characteristic length I / K is often called theradius of the ionic atmosphere; since on comparing equation (1)with the expression for the potential at a distance r from a pointcharge ZE, viz., XE/DT, it is seen that the potential due to the ionicatmosphere is equivalent to that of a charge ZE uniformly dis-tributed on the surface of a sphere of radius I / K surrounding thecentral ion, so that the two together are equivalent to a doublelayer of charge XE and thickness 1 / ~ .In water at 25" for a uni-univalent electrolyte 1 / ~ = 3 x l O 4 / 4 i cm., and in 0.01N solution1 / ~ = 30 x lo-* cm. while the mean distance between the ions is44 x lo-* cm. From equation (2) it will be seen that the radiusof the ionic atmosphere varies inversely with the square root ofthe concentration, and this accounts for the fact that such diverseproperties of solutions as activity coefficients and equivalent con-ductivities are found to be functions of 4; The effect of theatmosphere on the properties of the ion will naturally depend on1 / ~ , and equation ( 2 ) shows that this will diminish in concentratedsolutions and in solvents of low dielectric constant.The Eflect of the Ionic Atmosphere on the Ionic Mobility.-Theconductivity of a solution depends on the number of ions that i THE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 329contains and on their mobility.The classical theory of Arrheniusconsiders the effect of ionic dissociation on the former factor, whilstthe Debye-Huckel theory considers the effect of the interionicforces on the latter.If an ion moves in a solution under the influence of a uniformpotential gradient, it reaches a steady state of motion in which theelectric force acting on it is in equilibrium with the viscous forceopposing its motion. Debye and Huckel showed that both theseforces are modified by the ionic atmosphere.When an ion is stationary its atmosphere has central symmetry,but when it moves in an external field the atmosphere will nolonger remain symmetrical owing to the fact that its formation ordisappearance occupies a finite time, in consequence of which theelectric force acting on the ion will be altered.Debye and Huckel investigated, by means of the equations forthe Brownian movement, the rate of decrease of the density of theatmosphere if the central ion is removed, and they express thisrate in terms of an essential time constant 7 which they call thetime of relaxation of the atmosphere.To a &st approximation,the radius of an atmosphere is doubled during the time of relaxation7, which, for an electrolyte like potassium chloride with ions ofequal mobility, is given by the expression7 = - seconds .. . . . (3)u2kTwhere k is the Boltzmann constant and p is the frictional constant ofthe ion, defined as the force opposing an ion moving with unitvelocity, and is given by p = 1.5 x For a potassiumchloride solution in water at 25" containing c mols. per litre thisgives 7 = 0.55 x 10-lo/c secs.When an ion moves under an external potential gradient, it hascontinuously to build up a fresh atmosphere in front of it whilethe atmosphere has to die out behind i t ; consequently the atmo-sphere in front of the ion will never reach its equilibrium density,while behind it the density will be above its equilibrium value.Since the charge density of the atmosphere has the opposite signto the charge on the ion, the dissymmetry will reduce the externalelectrical force acting on the ion.Increase in the ionic velocityproduces an increased dissymmetry, and the consequent reductionof the field intensity, which we may call the dissymmetry term,varies directly with the velocity for small velocities. The actualdissymmetry is small ; for example, in an external field of 1 volt /em.,a potassium ion in a 0.001N-solution will move approximatelythrough 7/100,000 of the radius of its ionic atmosphere during itsL 330 MURRAY-RUST, CATTY, MACFARLANE, AND HARTLEY :time of relaxation, but even the slight dissymmetry thus producedis sufficient to cause an appreciable retardation of the ion owing tothe relatively enormous size of the electronic charge.The second way in which the ionic atmosphere influences theionic mobility is due to the increased viscous resistance caused bythe movement of the ions of the atmosphere in the opposite directionto the central ion.Since the ions are assumed to carry a certainamount of solvent with them, the viscous resistance to ionic motionis greater than if the solvent were a t rest. Debye and Huckelassume that the ordinary equations of motion in a viscous fluidhold right up to the surface of the ions where no slip occurs, andobtain an expression for the additional frictional force due to theionic atmosphere, which, like the dissymmetry term, varies inverselywith the radius of the ionic atmosphere and so is proportional tothe square root of tjhe concentration.Colloid particles acquire a charge and a potential with respectto the solution and consequently migrate in an electric field.Thephenomenon is called electrophoresis and is strictly analogous tothe migration of ions in an electric field, since the ion and its atmo-sphere are equivalent to a diffuse double layer of thickness l / ~ ,which is the exact counterpact of the diffuse portion of the doublelayer round the colloid particle. The main difference is that thecharge on the colloid particle is due to adsorption, and in generalalters with the concentration. Owing to the similarity betweenthe two phenomena, Debye and Huckel call the additional frictionalforce the electrophoretic term.Both these effects due to the ionic atmosphere reduce the mobilityof the ion below its value at infinite dilution, and from their calcul-ations Debye and Hiickel arrived at the following equation for thevariation of the equivalent conductivity of a x-valent binary electro-lyte in a solvent of dielectric constant D at a temperature T,where the first and second terms on the right-hand side are thedissymmetry and electrophoretic terms respectively, K , and K2are universal constants, w1 and w2 are valency factors, and b is theaverage radius of the ions.This reduces to the form* (5)which is identical with the empirical equation used by Kohlrauschfor the conductivities of dilute aqueous solutions. Comparisonwith experimental results shows that the coefficient of dt? inequation (4) is of the right order of magnitude if a value is assumedA, = A, - x ~ C .. . THE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 33 1for the ionic radii of 10-8 cm. in accordance with X-ray data. Butif the value of b is calculated from the ionic mobilities at infinitedilution, assuming Stokes's law to hold, the observed and calculatedcoefficients are not in exact agreement ; e.g., for potassium chlorideRolutions in water at 25" they are 0.461 and 0.547 respectively.Onsager's Modijication of the Debye-Hiickel Theory of Conductivity.-L. Onsager 179 l8 pointed out that Debye and Huckel, in cal-culating the retardation of an ion due to the dissymmetry of theatmosphere, had considered the dissymmetry round an ion whichmoved with a constant velocity in the solution and had neglectedits Brownian movement. Onsager recalculated the value of thedissymmetry term, taking into account this effect, and found thatfor 8 uni-univalent electrolyte a correcting factor of 2 - 2/.% = 0.586must be introduced into Debye and Huckel's dissymmetry term.He also reinvestigated the electrophoretic effect and showed thatits magnitude in dilute solutions was independent of any assumptionas to the validity of Stokes's law in the immediate neighbourhoodof the ions.The electrophoretic term has been the subject offurther papers by Debye and Huckel,lg who investigated it withspecial reference to the electrophoresis of colloid particles.Onsager's final equation has the same general form as Debyeand Huckel's, and when numerical values are inserted for theuniversal constants, it becomes for a z-valent binary electrolytewhere r) is the viscosity of the solvent.iinivalent electrolytes :For various solvents at 2.5" this equation becomes for uni-For water A, = A, - (0.228A0 + 59.8)dC,, methyl alcohol Ac = A, - (0*957A, + 158.l)dc,, ethyl alcohol A, = A, .- (1.25611, + 87.8)dcFor sodium chloride in each solvent these equations become :For water A, = 126.4 - (28.8 + 5 9 - 8 ) f i,, methyl alcohol A, = 97.0 - (93 + 158.l)dc,, ethyl alcohol A, = 43.0 - (54 + 87-8)dcThese equations show that the dissymmetry term and the electro-phoretic term (the first and second coefficients of respectively)are of the same order, but their relative magnitude varies with theproperties of the solvent and with the ionic velocities of the ionspresent.Limitations and Developments of the Theory of Debye an& Hucke1.332 MURRAY-RUST, GATTY, MACPARLANE, AND HARTLEY :The simple Debye and Huckel theory involves certain assumptionsand approximations which have been the subject of subsequentinvestigations.These have been concerned mainly with the limitsin which the theory might be expected to hold and with attemptsto adapt it to higher concentrations, but the equations have notyet been applied to the conductivity problem.All subsequent work has gone to show that the limiting equa-tion (1) is correct for high dilutions, but that it might be expectedto break down, even if allowance is made for the size of the ionsand for higher-order terms, when the potential energy of the ionsdue t o their atmospheres becomes comparable with their kineticenergy of translation. According to H.A. Kramers 20 and to R. H.Fowler,21 this occurs at about 0.01N for aqueous solutions ofuni-univalent salts at 25", and at lower concentrations when theinterionic forces are increased owing to the higher valency of theions or to a lower dielectric constant of the solvent, e.g., at N/600for uni-univalent salts in methyl alcohol.The physical assumptions underlying the theory may be sum-marised as follows :(i) That all forces other than Coulomb forces between the(ii) That corrections for the overlapping of the ionic atmo-(iii) That the solvent between the ions behaves like the pureions can be neglected.spheres can be neglected.solvent in bulk.The first assumption implies that the theory applies to an idealelectrolyte which is completely dissociated into point ions.Debyeand Huckel made allowance for a mean distance of closest approachof the ions, but experimental values for this additional constantwere subsequently shown by 0. Scharer 22 to be negative for dilutesolutions of thallous chloride in dilute aqueous thallous nitrate.The reason for this anomaly is the neglect of terms other t'hanthose of the first order in the derivation of equation (l), since thesebecome significant at concentrations where the effect of the ionicsize is important.R. H. Fowler,21 while investigating the second assumption, showedthat the neglect of the higher-order terms was equivalent to assumingthat the potential energy of an ion, due to the field and atmosphereof another ion, is small compared to its kinetic energy of translation.The overlapping of ionic atmospheres can, however, be overlookedif the potential of an ion due merely to the atmosphere of anotherion is small compared to itjs kinetic energy of translation, which isa less stringent condition.H. MulIerS3 and T. H. Gronwltl12THE ELECTRICAL COKDUCTIVITY OF SOLUTIONS. 333have considered the effect of the size of the ions on their activitycoefficients, and T. H. Gronwall, V. K. LaMer, and K. Sandved25have carried out a solution of the fundamental equations of Debyeand Huckel as far as terms of the fifth order for binary electrolytes.Their results give reasonable values for the ionic radii and alsoconfirm the view that there is a greater probability of finding anion in a region where its potential energy is great compared withits kinetic energy, than would have been predicted by the DebyeHuckel theory.As a result, the radius of the ionic atmospherewill be reduced and the properties of the solution so modified that,if compared with the simple theory, the electrolyte will appear tobe incompletely dissociated. Bjerrum 26 had previously attackedthe problem of ionic association* by considering the effect of thelimiting distance, to which two ions can approach one another, onthe probability of the formation of an ion pair, which would beequivalent to an undissociated molecule without involving theformation of a covalent linkage.The use of the macroscopic dielectric constant of the solvent hasbeen justified by P.Debye and L. Pauling 27 for sufficiently dilutesolutions, and a similar justification has been made by Onsager l7 asregards the viscosity. Hiickel 28 has investigated the effect of thevariation of the dielectric constant with concentration and of thedeformability of the ions. The intense pressures set up owing tothe electrostatic attraction of the polarisable and dipolar solventmolecules by the ions and the possibility of electric saturationround the ions have been considered from different points of viewby H. S ~ h m i c k , ~ ~ T. J. Webb,30 F. Z w i ~ k y , ~ ~ and D e b ~ e . ~ ~Conductivity at High Frequencies and High Electromotive Forces.The essential correctness of the view that there exists an ionicatmosphere, requiring a finite time for its establishment or dissip-ation, has been strikingly confirmed by recent work on the variationof the conductivity of solutions both at high frequencies and a thigh electromotive forces.According to the Debye-Huckel theory, the ionic atmosphere,owing to its time of relaxation, lags behind an ion moving with asteady velocity, and therefore produces a retarding force.If theapplied electromotive force is an alternating one with a long period,* The term association is used throughout this Report to imply anymodification of the state or configuration of the ions, which involves adecrease in the conductivity. This may be due either to the formation of acovalent linkage between them or to a modified distribution of the ions,leading in the extreme case to the formation of an ion pair as suggested by13 j errum334 MURRAY-RUST7 GATTY, MACFARLANE, AND IIARTLEY :the atmosphere still lags behind during the whole of the oscillationexcept for a short time a t either end when the ion reverses thedirection of its motion.At higher frequencies the amplitude ofthe oscillations of the ion and of the atmosphere both become small.P. Debye and H. Falkenhagen33 showed that, owing to this, thedissymmetry term should decrease to zero as the frequency increasesto infinity, the effect first being appreciable when the period ofoscillation reaches the order of magnitude of the time of relaxationof the atmosphere.It would therefore be expected that the conductivity of a solutionshould vary with the frequency of the current. But the investig-ation of this phenomenon is complicated because alternating electro-motive forces produce both a real and a capacity current.Bothincrease 33 with the frequency, the former appearing as an increasein the conductivity, and the latter as an increase in the dielectricconstant of the solution. Unfortunately, existing experimentalmethods are inadequate for the detection of this latter effect.On the other hand, the increase in conductivity with the frequencyhas been measured by H. Sack34 and H. Zahn35 and their co-workers, as well as by A. Deubner.36 Owing to the need to dis-tinguish between real and capacity current, the most convenientmethod is to adjust the concentrations of two solutions until theirbehaviour at a high frequency is identical, and then t o comparetheir conductivities at a low frequency.Results have been obtainedfor aqueous solutions by comparing in this way (i) salts of differentvalency types, and also (ii) salts with acids, since these are affecteddifferently by change of frequency owing to the high mobility ofthe hydrogen ion. Solutions of copper sulphate were comparedwith solutions of potassium chloride possessing the same high-frequency conductivity a t a wave-length of 16 metres in air, andat low frequencies their conductivit,ies showed a maximum differenceof 1.7 -& 0.15% when the concentration of the copper sulphatewas 0.0012N.The general result of the experiments is in satis-factory agreement with theory. Zahn,37 working a t a wave-lengthof 4.5 cm., considers that he has obtained evidence against Hiickel'stheory of the mobility of the oxonium ion [H30]'.M. Wien and co-workers 38 have observed that electrolytic solu-tions do not obey Ohm's law under high potential gradients. G.Joos and M. Blumentritt 39 showed that this phenomenon could beinterpreted in terms of the time of relaxation of the ionic atmosphere.I n a potential gradient of 500,000 volts/cm., the ions in a 0.001N-solution of potassium chloride in water a t 25" would move througha distance equal to 35 times the radius of their atmospheres duringthe time of relaxation.The ions would therefore become separateTHE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 335from their atmospheres and, in the limit, their mobilities wouldhave the same values as at infinite dilution. The effect of increasingthe potential gradient should vary with salts of different valencytypes, and this was tested experimentally by comparing the resist-ances of solutions of salts such as magnesium sulphate and sodiumchloride under different potential gradients. The results were foundto be in general agreement with theory.Additional evidence for the existence of a time of relaxation ofthe atmosphere has been obtained from a study of the viscosity ofaqueous solutions. G. Jones and M. Dolea concluded that, as aresult of the interionic forces, the viscosity of all electrolytic solu-tions must be greater than that of the pure solvent at high dilutions,although certain salts, such as potassium chloride or nitrate,are knownto lower the viscosity of water.H. Falkenhagen and M. Dole41later obtained a quantitative expression for the relative viscosityof dilute solutions in the special case of a binary electrolyte whoseions have equal mobilities, their calculation being based on thetime of relaxation of the ionic atmosphere. W. E. Joy and J. H.Wolfenden 42 have recently shown that the viscosity of aqueoussolutions of potassium chloride at concentrations below 0.02N isgreater than that of pure water and that the effect is of the calculatedorder.Recent Conductivity Measurements and a Comparison of the Resultswith the Deb y e-Huc kel-Onsager Theory .The following sections deal with the results of conductivitymeasurements in twelve solvents in which dilute solutions havebeen investigated.The percentage deviations of a number oftypical electrolytes from the Debye-Huckel-Onsager theory will befound on p. 342, where they are collected so as to facilitate a com-parison of the results in different solvents. The differences betweenthe observed and calculated values of x in equation (5) are, ofcourse, dependent on the values assigned to the dielectric constantsof the solvents, as to which there are often serious discrepanciesbetween the results of different authors. A greater measure ofagreement as regards these constants would be a great help toworkers in this field.In water there is a rather sharp contrast between weak electro-lytes (acids and bases) and uni-univalent salts, all of which arestrong electrolytes. It will be seen that in non-aqueous solventsthis difference disappears, for even uni-univalents salts may bemedium or weak electrolytes.Their nature is shown qualitativelyat once by the form of the A,/l/cgraphs as compared with thetheoret'ical line for each electrolyte336 MURRAY-RUST, GATTY, MACFARLANE, AND HARTLEY :Methods of Conductivity Neasurement .-The Ostwald method ofsuccessive dilution for determining the conductivity is subject tothe possibility of large errors in dilute solutions, owing to theuncertainty of the solvent correction and the cumulative experi-mental error.This method has been abandoned by most investig-ators in favour of that first proposed by W. C. D. Whetham,43 andused by F. Kohlrausch and M. E. M a l t b ~ , ~ ~ in which a number ofsuccessive additions of strong solution are made to the pure solventin the conductivity cell. The resistances of the solutions are alwaysmeasured by the Kohlrausch method, and much attention hasbeen paid, particularly in America, to refinements in the apparatus.The elimination of various errors due to the use of alternatingcurrent has been discussed at length by E. W. Washb~rn?~ S. F.A ~ r e e , ~ ~ J. L. R. Morgan and 0. M. Lammert,47 G. Jones and R. C.J ~ s e p h s , ~ ~ and T. Shedlo~sky.~~ A thermionic valve oscillator isnow generally used as a source of alternating current of symmetricalwave form ; suitable types are described by R.E. Hall and L. H.Adam~,~O H. U l i ~ h , ~ ~ J. W. Woolcock and D. M. Murray-Rust,52and by Grinnell Jones and G. M. B ~ l l i n g e r . ~ ~The design of conductivity cells has been discussed by E. W.W a ~ h b u r n , ~ ~ and their treatment by Morgan and Lammert .47Suitable forms for dilute solutions have been described by H.Hartley and W. H. B a ~ ~ e t t , ~ ~ by C. A. Kraus and H. C. Parker,55and by H. C. Parker,56 and the design of a conductivity cell foreliminating electrode effects has recently been published by T.Shedl~vsky.~~ The determination of cell constants has been studiedby H. C. Parker and E.W. Parker 58 and by M. Randall and G. N.S ~ o t t . 5 ~ A useful summary of experimental methods is given byC. W. Davies . l2Water.-A number of uni-univalent salts were measured in waterby F. Kohlrausch and few later measurements have been made.P. Walden and H. Ulich 6o repeated some of the work at 18" andextended it to measurements at 0" and 100" in order to see whetherthe product of the equivalent conductivity and the viscosity of thesolution is constant over a range of temperature. Their values at18" are in good agreement with Kohlrausch's except for potassiumand lithium perchlorates, so that the mobility of the perchlorateion is in doubt.H. J. Weiland 61 measured the conductivity of potassium chloridein very dilute solution, and his values are in reasonable agreementwith those of Kohlrausch and of Walden in the range where theyoverlap.In view of the great difficulty of obtaining trustworthydata at the extreme dilutions at which he worked, and of his ques-tionable method of extrapolation to A,, his claim that the resultTHE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 337are in accordance with the Ostwald dilution law at high dilutionscannot be sustained, quite apart from the fact that no allowanceis made for the change of mobility with concentration.Kohlrausch62 has shown that the conductivities of all the saltsinvestigated by him in water obey the relation A, = A, - q/z, andOnsager has compared the values of x found by Kohlrausch withthose calculated by equation (6), and finds that there is reasonableagreement for most uni-univalent salts, the average deviation fromCheory being about 7%.The observed values of x in most cwesare slightly greater than the theoretical values, the largest differ-ences being found for the nitrates. The values given on p. 342 aremainly for salts that have been measured in other solvents, andthe general agreement is closer than those figures would suggest.Lithium picrate appears to give an unusually large negative devi-ation. The values for bi-univalent salts are also in fair agreement,(& 15%), showing that the valency factors in the Debye-Huckel-Onsager equation are correct. Bi-bivalent salts give experimentalvalues of x which are considerably greater than the calculatedvalues, pointing to ionic association, and C.W. Davies G3 hascalculated dissociation constants for these salts.Methyl Alcohol (D = 30.3).-H. Goldschmidt's measurementswere largely concerned with the conductivities of acids,G4 whichare dealt with in a later section. He also measured a small numberof salts by the Ostwald method of dilution.65 P. Walden, H. Ulich,and F. Laun 66 measured a number of salts with organic kationsat O", 25", and 50°, and their results are discussed in the sectiondealing with Walden's rule. J. E. Frazer and H. Hartley 67 havemeasured the conductivity of uni-univalent salts over a range ofconcentrations from N/IO,OOO to N/500, and this work has beenextended to the thiocyanates by A. Unmack, D. M. Murray-Rust,and H.Hartley 68 and to the perchlorates by E. D. Copleyand H a r t l e ~ . ~ ~ All the uni-univalent salts obey the square-rootrelation and the experimental values of x agree well in many caseswith those calculated theoretically, but the individual differencesare often greater than in water, e.g., for silver nitrate, which isassociated even at high dilutions. In some cases, x&s. is slightlyless than xcalc., but the latter values depend on the number usedfor the dielectric constant of the solvent, and if a larger value than30-3 were used for the calculation, the value of xalcs would besmaller. A comparison of the results for the chlorides, nitrates,and thiocyanates of the alkali metals shows that the deviationsfrom Onsager's equation increase with the atomic number of theThe mobilities of the kations increase in the same order,and, if they are assumed to vary inversely with the sizes of th338 MURRAY-RUST, GATTY, MACFARLANE, AND HARTLEY :solvated ions, it appears that for strong electrolytes in methylalcohol the divergence from the theoretical behaviour is greatest forkations of small diameter in solution.L.Thomas and E. Marum io have recently measured some uni-univalent salts in methyl alcohol at high dilutions. They find alinear relation between A, and dc, but the slopes of their lines aregreater than those found by Frazer and Hartley and their valuesof A, are from 2 to 3% higher.Ethyl Alcohol (D = 25).-The results of Goldschmidt G49 71 andof Walden, Ulich, and Laun 66 for ethyl alcohol are also dealt withlater, as the scope of their investigations is similar to that in methylalcohol.The values quoted by Ulich lo for metallic salt's are mainlytaken from early work by Dutoit, Turner, and others, but Thomasand Marum 70 and Copley, Murray-Rust, and Hartley 72 haverecently published results for a small number of salts in ethylalcohol, and a continuation of the latter work by RI. Barak 73 extendst o a large number of uni-univalent salts. An examination of theresults in the light of the Debye-Huckel-Onsager equation showsthat ethyl alcohol is similar to methyl alcohol, as nearly all thesalts conform to the linear relation A, = A, - x d c . The differ-ences between the observed and calculated values of x are rathergreater than in methyl alcohol, and in no case is x&s. less thanxalc.If the lower value of 23, given by C. P. Smyth and W. N.Stoops 74 for the dielectric constant, were used in the determinationof xcalc., the agreement with the theory would be closer. Theresults show that the general tendency for ionic association totake place is rather greater in ethyl than in methyl alcohol, aswould be expected from the lower dielectric constant of the former.The dependence of the degree of divergence of a salt from idealbehaviour on the nature of the kation is similar to that in methylalcohol, as in each series of salts of the alkali metals the deviationincreases steadily from lithium to caesium.Nitrmethane ( D = 37).-Walden 75 and J. C. Philip and 13.R.Courtman 76 measured tetraethylammonium and potassium iodidein this solvent, and later J. C. Philip and H. B. Oakley 77 extendedthe measurements with potassium iodide over a wide temperaturerange. Ehrther work has been done by C. P. Wright, Murray-Rust,and H a r t l e ~ . ~ ~ Ionic association takes place t o a much greaterextent in nitromethane than in either of the alcohols, in spite of itshigher dielectric constant. None of the salts with metallic kationsgive a linear relation between A, and dc over the range 0.002 to0.0001N and, where t'here is a linear portion of the curve, theslope is much greater than that calculated from Onsager's equation.The influence of the nature of the kations on the degree of associatioTHE ELECTRICAL CONIIUCTIVITY OF SOLUTIONS.339is opposite to that in the alcohols. This is illustrated by thebehaviour of the thiocyanates : the potassium salt is a fairly strongelectrolyte, sodium thiocyanate is of intermediate strength, whilelithium thiocyanate is a weak electrolyte, the degree of dissociationat N/1000 being as low as 12%. The nature of the anion also hasa large influence, the perchlorates being much less associated thanthe thiocyanates.The tetraethylammonium salts, on the other hand, conform tothe square-root relation, and the experimental values of x are inclose agreement with those calculated theoretically, the nature ofthe anion having little effect on the behaviour of the electrolyte.The difference in behaviour of nitromethane and hydroxylicsolvents may be due to the fact that the former, having a purelydonor character, can only form co-ordinate links with the kations,while the hydroxylic solvents can form links both with the kationsand with the anions.Acetonitrile ( D = 36).-The most important work in this solventis that of Walden and E.J. Birr,79 who measured a large numberof organic salts and a few with metallic kations. The behaviourof salts in this solvent is similar to that in nitromethane, as wouldbe expected from the fact that their dielectric constants are nearlyequal and that neither is a hydroxylic compound. Though themetallic salts conform to the linear relation A, = A, - x d c , theexperimental values of x are always greater than those calculatedfrom equation (6).The picrates show that the influence of thekation on the degree of association in solution is also similar tothat found for nitromethane, as the association increases in theorder KPic, NaPic, LiPic, the lithium salt being only about 65%dissociated at N/1000. All the tetra-substituted ammonium saltsare strong electrolytes, obeying the square-root relation, and manyof them give values of x close to those calculated theoretically.The smallest values of x&s. are given by the tetrapropylammoniumsalts and they are in every case lower than the theoretical values.The deviations of the tetramethyl- and tetraethyl-ammonium saltsare similar, though rather lower for the former. The mono-, di-,and tri-substituted ammonium salts are all considerably associatedin acetonitrile, and the nature of the anion has a large influence onthe degree of association, the liicrates and iodides being much strongerelectrolytes than the chlorides.Nitrobenzene ( D = 346).--There are not many data for this sol-vent, but the results of Murray-Rust, H.J. Hadow, and Hartley 80show that it is similar to nitromethane as an ionising solvent.Tetraethylammonium salts do not show large divergences fromideal behaviour, while silver perchlorate, the only metallic sal340 MURRAY-RUST, GATTY, MACFARLANE, AND HARTLEY :which has been measured, is appreciably associated in solution.The degree of association in every case is rather greater in thissolvent than in nitromethane.Benzonitrile (D = 25-2).-A. R.Martin 81 has measured the con-ductivity of the iodides of lithium, sodium, potassium and tetra-et'hylammonium, of lithium bromide, and of silver nitrate over arange of temperature from 0" to 70". The first three salt,s giveapproximately straight lines when A, is plotted against 2/c, althoughthey are represented better by the empirical equation of A. Fergusonand I. Vogel,s2 vix., A, = A, - Ben, where n is not equal to 0.5 :this equation is discussed later. The experimental values of x int'he equation A, = A, - XI& are about twice as great as thosecalculated from Onsager's expression, so that these salts are notcompletely dissociated. Lithium bromide and silver nitrate areweak electrolytes, the degrees of dissociation at N/1000 beingrespectively about 44% and 50% at 25".Tetraethylammoniumiodide, however, obeys the square-root relation and, though itshows a considerable deviation from the ideal slope, it i8 thestrongest electrolyte investigated.Acetone (D = 21).-Walden, Ulich, and G. Busch 83 have measureda number of salts in this solvent, but, except for potassium andsodium iodides and lithium picrate, they are all salts with organickations. Many of them give straight lines when A, is plottedagainst d?, but the slopes of these lines are in every case greaterthan those calculated from Onsager's equation ; the tetra-sub-stituted ammonium picrates show the nearest approach to idealbehaviour, the smallest deviation being found for tetrapropyl-ammonium picrate. N. L. Ross Kane 84 * has extended this inves-tigation to a number of metallic salts and has also repeated someof Walden's measurements.Although there is fair agreementbetween the results for the tetraethylammonium salts in the twoinvestigations, the values of A, obtained by Ross Kane for the saltsof the alkali metals are about 3% higher than those of Walden.For the picrates, thiocyanates, and iodides of the alkali metals theionic association is greatest for the lithium salts and least for thepotassium salts, so that in this respect acetone is similar to nitro-methane as an ionising solvent; lithium thiocyanate and picrate(and also the chloride) are weak electrolytes in acetone, though thethiocyanate is rather stronger than in nitromethane. The per-chlorates, however, are exceptional, for none of them is highlyassociated and the degree of association, as measured by the deviation* The publication both of this paper and that of A.Unmack andE. Bullock 119 has been delayed owing to the preparation of this Report, butvalues from them have been included for the sake of completenessTHE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 341of the slope of the A J f i lines, increases from lithium to potassium.The weakest metallic uni-univalent salt in acetone is silver nitrate,which is only about 10% dissociated at N/2000. Certain mono-and di-substituted ammonium chlorides are also weak electrolytes.Ethylene Dichloride (D = lo).-The results are due to the workof Walden and Busch 85 and are restricted to salts with organickations.None of the salts is a strong electrolyte, but the tetra-substituted ammonium salts are the most ionised. The degree ofdissociation for these increases with the number of carbon atomsin the kation, and at N/2000 varies from 25% for tetraethyl-ammonium picrate to 55% for tetraisoamylammonium picrate.The di- and tri-substituted ammonium salts, on the other hand,are very weak electrolytes and the degree of dissociation at N/2000is less than 1% in all cases.Tetrachbroethane (D = 8) .-A few tetra-substituted ammoniumsalts have been measured in this solvent by Walden and H. Gloy 86at concentrations below N/10,000. They find that all the saltsare weak electrolytes, the strongest being only about 50% dissociatedat N/10,000.s-Dichloroethylene (D = 7, approx.).-The results in this solventare also due to Walden and Gloy.86 The work was mainly restrictedto the di-, tri-, and tetra-isoamylammonium salts; all are weakelectrolytes but the fully substituted salts are, as in other solvents,much more ionised than the other salts.At N/1000, the degree ofdissociation for the fully substituted compounds is about lo%,while none of the other salts is more than 1% dissociated.Summary of the Results for Uni-univalent Salts in Various Sol-vents.-There is ample evidence of the close approach to a linearrelation between A, and G i n a number of solvents as required bythe Debye and Huckel theory, and the extent of the agreementbetween the measured slope of the conductivity in different solventswith that calculated by the Debye-Huckel-Onsager equation isshown in Table I, which gives, for a, number of typical salts, thepercentage deviation, 1O0(zob, - zaaro.)/zmlc..It will be seen that in each of the first five solvents there aresome salts which show close agreement with theory, and it is sig-nificant that with few exceptions any large deviation from idealbehaviour is in the direction that can be explained by ionic associ-ation, namely that is greater than zalc.This body of evidenceappears to be sufficient to justify the use of the Debye-Huckel-Onsager equation as a working hypothesis to represent the behaviourof an ideal electrolyte, and we have therefore a new means ofinvestigating the degree of association of electrolytes in the dihiterange where the theory can be applied with safety342 MURRAY-RUST, GATTY, MACFARLANE, AND HARTLEY :TABLE I.Percentage deviations from Onsager’s equation at 25O.p o .........D2S0 .........LiCNS ...NaCNS ...KCNS ......RbCNS ...CsCNS ...LiI .........KI .........LiC10, ...NaC10, ...LiPic ......NaPic ......AgNO? ...NEt,Pic ...NEtJ ......NEt,ClO,Water.*0.0 105681.317t3-i-6.1-- st--- 8-s- 12- 3216:-1 5- 10--MeOH.0.0064530.3- 1- 20010- 10- 28370173340--EtOH.0.010802518243 7547s103 810521610413075102184CH,*NO,.O*OOC,B 737weakweak158--30073430175---- 1.599 IAcetone.0.0030s21[960]250122122124!) 8586473270190weak349868* All values for water are at 18”.t These values refer to the chlorides, not to the thiocysnates, as no accurate$ This value is for potassium perchlorete.measurements of the latter have been made in water.As Walden 87 and Ulich 88 have pointed out, a general comparisonof the conductivity results reveals a most striking contrast betweenwater and the two lowest alcohols and the non-hydroxylic solvents.In water, all uni-univalent salts are strong electrolytes, and this istrue also of methyl and ethyl alcohol, but in these solvents individualdifferences begin to make their appearance as the interionic forcesincrease and the varying tendencies to association are brought tolight.Much of the extraordinary regularity of the conductivitycurves in Kohlrausch’s classic diagram 89 for aqueous solutions dis-appears when the same values are plotted for the alcohols. Never-theless, the hydroxylic solvents favour complete ionisation andsuppress the individual tendencies of electrolytes, their effect beingdescribed by Ulich as ‘‘ nivellierend” or levelling, as opposed tothe non-hydroxylic solvents such as nitromethane, nitrobenzene,acetonitrile, and acetone (described by Ulich as ‘‘ differenzierend ”)?in which uni-univalent salts may be weak electrolytes. This is notthe result of larger interionic forces, since the first three have largerdielectric constants than methyl alcohol.Another difference between the two classes of solvent is that inthe alcohols the tendency to association in any series of salts witht,he same anion increases with the atomic number of the kation,while in the non-hydroxylic solvents the association increases inthe order K’ < Na’ < Li’ (with the possible exception of the perTHE ELECTRICAL CONDUCTWITY OF SOLUTIONS.343chlorates in acetone), and the lithium salt is often a weak electrolytewhen the potassium salt is highly ionised. The relative tendenciesof the anions to promote ionic association are not quite so markedbut are roughly in the order(ClO,‘, Pic’, 1’) < (Br’, NO,’) < (Cl’, CNS’)although there are variations from this scheme.In the alcohols, the tetra-substituted ammonium salts show themaximum deviation from the theoretical slope, while in the non-hydroxylic solvents they give results which agree most closely withtheory .In each type of solvent the general tendency to associationincreases as the dielectric constant decreases, though this is notalways true, as a few salts are more highly dissociated in acetonethan in nitromethane.It will thus be seen that a purely physical theory such aa that ofDebye, Hiickel, and Onsager, while it is of great value in predictingthe behaviour of an ideal electrolyte, is far from giving a completepicture of the behaviour of electrolytic solutions.The chemicalnature of the solvent molecules and of the ions themselves isoften the predominant factor.The Conductivity of Acids in Different Solvents.-Acids are treatedseparately, as they hold a special place among electrolytes owingto the unique nature of the hydrogen ion.Taking first the acidswhich are strong electrolytes in water, the experimental work inaqueous solutions is not as accurate as that for salts, since the diffi-culties of investigating acids, especially in dilute solution, are somuch greater. H. C. Parkergo made accurate measurements ofhydrochloric acid and the results obey the square-root relationexcept in very dilute solution, where the deviations are almostcertainly due to reaction with solvent impurities. Onsager l8 hasshown that the slope of the line is in good agreement with thatcalculated theoretically. Davies 91 pointed out that iodic acid isnot completely dissociated even in dilute solution, and this isconfirmed by a comparison with Onsager’s equation.Goldmhmidt and Dahll64 measured the conductivity of hydrogenchloride, bromide, and iodide in methyl and ethyl alcohols, and themeamrements of the first were recently extended to more dilutesolutions by Thomas and Marum.70 All three halogen acids arefound to be highly dissociated in both solvents, although in Gold-Schmidt’s work the points do not lie on straight lines when & isplotted against l/c.This may be due, however, to the use of theOstwald method of dilution. The work on hydrogen chloride wasrepeated by Murray-Rust and Hartley,92 who also investigated 344 MURRAY-RUST, GATTY, MACFARLANE, AND HARTLEY :number of other acids which are strong electrolytes in water.Ofthese, hydrochloric, perchloric, ethylsulphuric, and benzenesulphonicacids are strong electrolytes in both alcohols and conform to thesquare-root relation. The deviations from equation (6) are greaterin ethyl alcohol, showing that there is more ionic association inthis solvent than in methyl alcohol; the deviation is smallest forhydrogen chloride in methyl alcohol, which is in quite good agree-ment with theory. Nitric and thiocyanic acids are weak acids inethyl alcohol and have dissociation constants of the order ofwhile the tendency of iodic acid to associate in aqueous solution isaccentuated in methyl alcohol, in which it has a dissociation constant,of about 10-8.Very few measurements of acids have been made in non-hydroxylicsolvents.In nitromethane, Wright, Murray-Rust, and Hartley 78have shown that perchloric acid is the only one that is highlydissociated, other acids which are strong in the alcohols, such ashydrogen chloride and benzenesulphonic acid, being very weakelectrolytes; and the same is true for nitric and thiocyanic acids.Ross Kane 84 has found similar results in acetone, in which per-chloric acid is the only strong acid and conforms to the square-rootrelation, and in nitrobenzene 80 it is a much stronger electrolyte thanany other acid measured, although in this solvent it is only about55% dissociated at N/1000. These results further emphasise thefact that the degree of ionisation of an electrolyte in any solventis controlled by the chemical properties of the solvent as well as byits dielectric constant.They also illustrate the relative reluctance ofthe perchlorate ion to form covalent links with a kation in solution.Turning now to acids which are weak in water, Goldschmidt andhis co-workers 7l9 93 have measured the conductivity of a numberof these in methyl and ethyl alcohols, and find that their dissociationconstants are considerably lower in these solvents than in water,the mean ratios of the dissociation constants in the different sdventsbeingKH,O /KN~o~: = lo4 KMeOH/KEtOlI xz lo4H. Hunt and H. T. Briscoe 94 have measured the conductivity of anumber of weak acids in water and the four lowest primary alcoholsand also in acetone. They find that the conductivity of the acidsdecreases with increasing molecular weight of the alcohol, butthere is more difference between ethyl and propyl alcohols thanbetween propyl and butyl alcohols.The calculation of dissociation constants of weak electrolytes hasbeen modified by the new theory, as two corrections have to bemade in the expression Ac2.c/R,(Ro - &)THE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 345(1) The denominator in the expression Ac/A, does not allow forthe fall in mobility with increasing concentration owing to theinterionic forces, and the true degree of dissociation is given bya = &/A’ where A’ is the conductivity which the electrolyte wouldhave at concentration c if it were completely dissociated. This canbe calculated from the Debye-Huckel-Onsager equation.(2) The ionic concentrations in the expression for the dissociationconstant should be multiplied by the activity coefficients.The final expression for the true dissociation constant isK = a2f2c/(l - a),where f is the mean activity coefficient of the ions, and o! = AC/lI‘as above.This equation was applied to weak acids in waterby D. A. MacInnes95 and by M. S. Sherrill and A. A. NoyesYQ6though the calculation of a was made from experimental resultsfor strong electrolytes, as Onsager’s equation had not been pub-lished. This method of calculating K has been applied to saltsin water by Davies,63,9* to uni-univalent salts in benzonitrile byMartin,*l and to acids in methyl and ethyl alcohols by Murray-Rustand Hartle~.~2Ionic Mobilities.Determination of Values of &,.-There are two main extrapolationformulae by which the equivalent conductivity at idnite dilutionof strong electrolytes has been obtained.Most authors use thesquare-root relation A, = A, -. a&, which has theoretical supportand represents the behaviour of many uni-univalent electrolytes indilute solution, both in water and in non-aqueous solvents, althoughin the latter the experimental slopes are often greater than thosecalculated from Onsager’s expression. I n this case the theoreticaljustification for the procedure is removed, and the points on thegraph might be expected to lie on a curve which would becometangential to the theoretical slope in very dilute solution, but as ageneral rule they do lie on a straight line even when the slope isconsiderably greater than the theoretical value, as for example inacetone.A curvature in dilute solution is sometimes obtainedexperimentally, even when the linear portion at higher concen-trations does not deviate widely from equation I (6), but this isprobably due to experimental error, arising from reaction of thesolute with solvent impurities or from some other cause. Thejustification for this view is that the degree of curvature is dependenton the nature of the solute and not on the slope of the linear portion,and that the deviation from the straight line is greatest whensolvent of high specific conductivity is used. In some unfavourablecases the curvature is so pronounced that a maximum is obtained346 MURRAY-RUST, GATTY, MACFARLANE, AND HARTLEYas in Gibbons and Getman’s curve for silver nitrate in methylalcohol.l12 In a few cases, however, when the electrolyte is of anintermediate nature, a curvature of the A , / d c line is obtainedwhich is probably due to decreased association in dilute solution :examples of this are thallium chloride la and iodic acid 91 in waterand silver perchlorate in nitrobenzene,80 which give curves tendingto become tangential to the Onsager slope at high dilutions.It is clear, therefore, that extrapolation on the square-root basismay give values of A, which are too high when the slope of the lineis greater than the theoretical value, as this method neglects thepossibility of curvature in very dilute solutions; the value will bemore nearly correct as the slope of the linear portion approachesmore closely to the calculated value.The other method of extrapolation is due to A.Ferguson andI. Vogel, 82a g9 who considered that a large number of electrolytes inwater do not conform sufficiently closely to the square-root relationto justify its use as an extrapolation formula, and in a later paperhave extended their calculation t o methyl alcohol.lm They use amodified form of t’he Storch equation, vix., A, = A, - Bcn, andhave worked out a graphical method for determining the arbitraryconstants B and n. These values of n are different for each electro-lyte and vary for water from 0.374 for potassium chloride to 0.97for hydrochloric acid.A possible danger in using this method isthat the value of n for any electrolyte may depend too much onthe accuracy of the values of A, in very dilute solution, which areparticularly liable to error. For instance, the existence of amaximum at 0-0001N in the graph of Parker’s results for hydrogenchloride in water shows that they are affected by the presence ofsolvent impurities or some other cause. Ferguson and Vogel, how-ever, arrive at a value of A, which is probably too low, since theyhave taken into account points below the straight line drawnthrough the values at concentrations greater than 0-0002N, althoughthis has almost exactly the theoretical slope (compare Davies 9 7 ) .On the other hand, the method may be most useful when theextrapolation on the square-root basis is impossible owing tothe curvature of the graph, as, for example, with solutions inbenzonitrile.The mobilities given on p.351 are all calculated from values ofA, found by extrapolation on the square-root basis, with the excep-tion of those in benzonitrile and in nitromethane.Transport Numbers.-In order to calculate the mobilities of indi-vidual ions from the equivalent conductivities at infinite dilutiona knowledge of transport numbers is required. Since these varywith concentration, special importance attaches to the values iTHE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 347dilute solution, the determination of which involves considerableexperimental difficulties. It is clear, however, from a collection oftransport numbers such as that given by Kohlrausch and L.Hol-born101 that they tend to become constant in water as the con-centration falls to O-OlN, and this is what might be expected ongeneral grounds in dilute solutions. Further, Washburn's correc-tion l02 for the differential shift of solvent with the ions duringelectrolysis brings the transport numbers of the alkali halides in1.25N solution much nearer to their values at 0-01N and in thecase of potassium chloride makes them identical, showing that theapparent variation with concentration is due in part to unequalsolvation of the ions and not entirely to variations in their relativespeeds at different concentrations.Three methods of determination are available : (1) the analyticalmethod of Hittorf, adapted for use in dilute solutions by B.D.Steele and R. B. Denison; lo3 (2) the moving-boundary method ofDenison and Steele lo4 which has been elaborated lately by MacInnesand his co-workers lo5 to give results of high precision, though it maybe diflticult to use at high dilutions; (3) the E.M.F. method,developed by D. A. MacInnes and J. A. Beattie 106 to give transportnumbers at definite concentrations instead of mean values for aconcentration range. The actual method of computation used bythem implies a continuous variation of the value in dilute solutionand seems therefore unsuitable for use in this region.In aqueous solutions the three methods yield results that agreeclosely. The mobilities of ions at 18" in water are based on thetransport number for the potassium ion in potassium chloride of0-495.If the mobilities of other ions are calculated from con-ductivity results by means of this value, excellent agreement isfound between the calculated and observed transport numbers.D. A. MacInnes and I. A. Cowperthwaite 1°7 have pointed outthat the agreement between the mobilities of the chloride ion deter-mined from various univalent chlorides up to the dilutions of 0-1Nis additional evidence of the existence of complete dissociation inaqueous solution ; corresponding discrepancies in the case of somenitrates and iodates point to some measure of association in thesesolutions which is confirmed by other evidence.In other solvents, transport data are much more scanty and muchless consistent in dilute solutions.If the Hittorf method is used,the analysis of dilute solutions and the manipulation of volatilesolvents offer considerable difficulties. For the E.M.F. method,electrodes reversible to both ions of the electrolyte are necessaryand so measurements in the alcohols are practically limited tosolutions of hydrogen chloride, since J. H. Wolfenden lo8 and J. R348 MURRAY-RUST, CATTY, MACFARLANE, AND IIARTLEY :Partington and H. G. Simpsonlm have shown that amalgamelectrodes give anomalous results at low concentrations.In methyl alcohol, G. Nonhebel and Hartley 110 measured theE.M.P. of hydrogen chloride cells with and without liquid junctionsover a wide concentration range and found the transport numberof the hydrion in dilute solution to be 0.735.Similar experimentsby J. N. Pearce and H. B. Hart,lll using amalgam electrodes, gavea transport number of the lithium ion in lithium chloride of 0-324,while V. L. Gibbons and F. H. Getman's 112 value for silver insilver nitrate, nag = 0.421, obtained by the analytical method,agrees with the previous result, 0.428, of H. C. Jones and H. P.Bassett ,113In ethyl alcohol, J. R. Partington, G . F. I ~ a a c s , ~ ~ * and H. G.Simpson109 find that the transport numbers for the kations ofsodium and potassium iodides are 0.418 and 0.450 respectively.They consider their measurements with amalgam electrodes to beunreliable at concentrations below O-lN, and hence have cal-culated transport numbers from their measurements of the cellswith liquid junctions alone, on the assumption that the ratio ofthe activity coefficient at two concentrations is equal to the ratioof the equivalent conductivities.For the transport number oflithium in lithium chloride, values ranging from 0.32 to 0-41 havebeen obtained, the most trustworthy of which is probably that ofC. Drucker and R. Schingnitz,115 viz., 0.38. H. S. Harned andM. F. Fleysher 116 have found the transport number of the hydrionto be 0.755 at 0.002N from a study of hydrogen chloride concen-tration cells, while J. W. Woolcock, H. Hartley, and 0. L.Hughes 117 by similar experiments obtained a value of 0.710. Theformer authors used MacInnes' s method of calculation and so theirnumbers in the dilute range are probably too high.Table I1 gives a comparison between the observed values of n, inboth alcohols, and the values calculated from the equivalent con-ductivities by means of the transport number of hydrogen chloridein dilute solution.The absence of any such concordance as existsTABLE 11.Transport numbers..n, in MeOH at 25'. ?L, in EtOH at 26O.Electrolyte. Conc. Obs. Calc. Conc. O h . Calc.HCI ............ 0.001N 0.735 110 (0.735) 0.001N 0.710 'I7 (0.710)LiCl ............ 0.006N 0-324 111 0.436 0.01N 0.38 115 0.376NaI ............ 0-001N 0.418 lo' 0.395KI ............... 0.001N 0.460 'la 0.434AgNO, ......... 0.0W 0.421 112 0.460 0-06N 0.39'7 '12 0.387O.OOlN( 0.756 'ITHE ELECTRICAL CONDUCTMTY OF SOLUTIONS. 349in the data for aqueous solutions is at once apparent, although theagreement is better in ethyl than in methyl alcohol.From a study of silver nitrate concentration cells with liquidjunctions, F.K. V. Koch 11* found the transport number of thesilver ion to be 0-458 in acetonitrile and 0.466 in benzonitrile. Inother solvents, transport -number measurements are either entirelylacking or confined to strong solutions.Walden's Rule.-The relation on which Walden and Ulich lohave based the calculation of ionic mobilities in a number of organicsolvents is that, for certain large organic ions, I,? is constant,where lo is the mobility of the ion and q the viscosity of the solvent.If the motion of the ion obeys Stokes's law or any other expressionof the same form, viz., velocity = (constant x force)/(ionic radius),then the constancy of the product Zoq is a measure of the extent towhich the ionic radius remains unaltered in different solvents.Walden and Ulich have shown that the product for a number ofions is practically constant over a wide range of temperature bothin water and in other solvents, but Ulich's values for lo? for typicalions in water and the alcohols (Table 111) show that for monatomicions the values are roughly twice as great in water as in methylalcohol and smaller again in ethyl alcohol, which may indicate arelation between the radius of the solvated ion and the molecularvolume of the solvent.For organic ions, such as NEt,' and thepicrate ion, the values of lor are almost constant in the threesolvents, which suggests the abse'nce of solvation.TABLE 111.Values of $q at 25".Water.MeOH. EtOH.K ........................ 0.68 0.30 0.26Na' ........................ 0.46 0.26 0.24Li' ........................ 0.36 0.22 0.19C1' ........................ 0.69 0.29 0.23Pic' ........................ 0.270 0.273 0.263NEt,' ..................... 0.294 0.295 0.296Walden has recently tested the accuracy of the rule by measuringthe product A,-,? for a salt containing both a large kation and alarge anion. Tetraethylammonium picrate, in particular, has beenmeasured in a large number of solvents, and Walden finds that theproduct byl is sensibly constant in each case and is close to themean value 0.563 85 at three different temperatures.Table IVgives Walden's values in a number of solvents at 25" (water, 18').The values given in brackets are due to other authors, and theconstancy of Aoq may not be quite so exact as Walden supposed360 MURRAY-RUST, CATTY, MACFARLANE, AND HARTLEYTABLE IV.Values of 4-q for tetraethylammonium picrate.Water. MeOH. EtOH. CH *NO,.A. ............ 63.3 102.9 51.5 (93.5) 7 871 ............ 0-01056 0.00546 0.01080 (O.OOSZ7)A07 ............ 0.563 0.562 0.557 (0.586)4 ............ 163-8 (32.7) 177.6 71-37 ............ 0.00344 (0.0183) 0.00316 0.00785Aoq ............ 0.563 (0.598) 0.561 0.660(108.6) 11* (55.2) 73(0.693) (0.596)CH3*CN. C,H,*NO,. Acetone. CH,Cl*CH,Cl.(0.00308) 84(0.550)Further investigations are necessary to clear up these discrepancies,but in any case the rule is sufficiently closely obeyed to justify theuse of this method of calculating mobilities from mean values ofthe product of Zo and the viscosity of the solvent in cases where noother method is at present available.Walden uses the mobility of the tetraethylammonium ion forthis purpose, taking a mean value of 0-295 for loq; other authorshave used the picrate ion with a value of 0.275.78J30Table of Ionic Mobilities.--The investigations on which the valuesof ionic mobilities in Table V are based are as follows : I n waterthe values given were calculated from Kohlrausch's values at 18",his temperature coefficients lol being used except in the case ofnumbers for which a special reference is given.In methyl alcohol,the values depend on the conductivity results of Frazer and Hart-ley 6' and the transport number of the hydrion in hydrogen chlorideof 0-735; 110 and in ethyl alcohol, on the conductivity results ofBarak 73 with the analogous transport number of O.71.Il7 In othersolvents, the values have been calculated from Walden's rule; innitromethane and acetone, from the picrate ion, taking loq = 0-275,and in acetonitrile from NEt,', taking Zoq = 0-295.The con-ductivity measurements were made in nitromethane by Wright,Murray-Rust, and H a r t l e ~ , ' ~ in acetonitrile by Walden and Birr,79and in acetone by Ross Kane.84 I n the last solvent the valuesin brackets are taken from the results of Walden, Ulich, andBusch. 83The main points of interest arising out of the following table are:(1) the periodic increase in each solvent of the mobilities of the ionsof the alkali metals with increasing atomic number, (2) the absenceof such a general periodic relationship in the mobilities of thehalogen ions, (3) the relatively large mobilities of a number ofpolyatomic ions as compared with monatomic ions in non-aqueouTHE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 351Ion.H' ......Li' ......725" =Na' ......K' ......Rb' ......CS' ......NH,' ...NEt,' ...Ag' ......Water.: 0.00895361 so39.651.074-277-678.174-033.0 lo63.0TABLE V.Ionic mobilities at 25".MeOH.0.0054514239.745.753.757.462.367.962 ll050.3 69(53) 66EtOH.0-0108059.514.918.722.023.625.519.228.417.5CH,*NO,.0,0062763555860-6449.552CH,-CN. Acetone.0-00344 0.003088859 757086-'"s)Wf3)-8898--86t 90Pi)8589 24.3 I C1' ......75.4 51-396 Br' ...... 77.7 55-5I' ......... 76-4 61 28.7 62 101ClO,' ... 67 6o 70.9 69 33.8 64 104Pic' ...... 30.7 lo 46.7 26-8 44 * 7870 - CNS' ... 65.4 61 6 8 29.2NO,' ... 70.6 60.8 28.1 64.5 10425.8 -* Calculated from l0q = 0.275.-f Calculated from 1 , ~ = 0,295.solvents, the most noticeable being NEt,' and CIO,'. Varyingdegrees of solvation are generally thought to be responsible forthese differences, and the high mobilities of ions with symmetricalstructures such as NEt,' and C10,' are suggestive in this respect.The hydrogen ion occupies a special position in view of its abnor-mal mobility in hydroxylic solvents.A chain mechanism involvingthe transference of a proton from an oxonium ion, (OH,)', to a,water molecule has been suggested to explain this, and Huckel 1mhas made a mathematical analysis of the problem with especialreference to the temperature coefficients of the mobilities of thehydrogen ion and of the hydroxyl ion, for which a similar chainmechanism has been assumed. In acetone and nitromethane, onthe other hand, the hydrogen ion does not possess an abnormalmobility; in these solvents the formation of complexes similar to(OH,)' and ROH,' is unlikely and consequently the mobility of thehydrion cannot be increased by proton transference.The Sdvation of Ions and its Relation to Ionic Dissociation.R. Fricke 121 has given an excellent summary of the work on theSince then, much attention has been solvation of ions up to 1922352 MURRAY-RUST, GATTY, MACFARLANE, AND HARTLEY :given t'o the question of solvation but, although the evidence fromvarious quarters for its existence and its influence on ionic dis-sociation has been considerably strengthened, it cannot be saidthat our views about the nature of solvation have become muchmore definite or have assumed a more quantitative form.H.Remy 122 and G. Baborovskf 123 have investigated independ-ently the movement of water with ions during electrolysis bymeasuring the shift of solution when the anode and cathode com-partments are separated by a membrane.Their results are infairly good agreement with one another and also with those ofWashburn,lo2 who used an electrically inert reference substance.Washburn's experiments have received further co&mation fromM. Taylor and E. W. Sawyer,124 who used urea as a referencesubstance instead of raffinose. Remy, on the assumption thatcertain large organic ions are not solvated, has estimated thedegree of hydration of a number of ions, his values varyingfrom 12H20 for Li' to 4H,O for Cs'. Ulich lo made a similarestimate, both in water and in other solvents, by calculating thenumber of solvent molecules required to account for the differencein size between the solvated ion calculated from its mobility byStokes's equation and the same ion in a crystal lattice.His num-bers are smaller than Remy's, e.g., 6-7H20 for Li'. He pointedout that the relative solvation of different ions is likely to be affectedby steric influences resulting from the dipole configuration of thesolvent molecules.The molecules of solvent may be held by the ions simply byvirtue of their dipole character, or they may be held by co-ordinatelinkages. Schmick29 has developed the work of M. Born126 onthe effect of the neighbouring dipole molecules on the mobility ofan ion, and has shown that in the case of water the dipoles wouldbe so strongly held by small ions that they would lose all degreesof freedom. N. V. Sidgwick 126 has considered solvation from theelectronic standpoint and has emphasised the importance of thedonor and acceptor properties of hydroxylic solvents in enablingthem to form co-ordinate links with both anions and kations.Healso pointed out that the relative solvation of the ions of the alkalimetals is in accordance with K. Fajans' 12' theory of the influenceof the size of an ion on its power to deform the electron orbits of aneighbouring ion or molecule.Bjerrum26 has considered the effect of ionic size on the prob-ability of the formation of ion pairs, which would contribute nothingto the conductivity of a solution, and has shown that, if the sumof the radii of two ions is below a certain value, the number of ionpairs will increase rapidly. The Debye-Huckel theory takes nTHE ELECTRICAL CONDUCTIVITY OF SOLUTIONS.353account of the association of ions, and the conductivity data forany series of salts of the alkali metals in methyl or ethyl alcoholshow an increasing deviation from theory with increasing atomicnumber, corresponding to an increase in association with diminutionin size of the solvated ion, Hence the solvation of the ions has animportant effect in reducing association by preventing the ionsfrom coming near enough together to form ion pairs. It is sig-nificant that, in non-hydroxylic solvents such as nitromethane,which can only form a co-ordinate link with the kation, most lithiumsalts are weak, in spite of the high dipole moment of the solventmolecules, indicating the importance of a chemical link between theanion and solvent in preventing ionic association.Ulich 88 has pointed out that valuable evidence as to the depend-ence of ionisation on the properties of the solvent molecules hasbeen obtained from the effect of the presence of small quantities ofwater (005% or less) on the conductivity of solutions in othersolvents.The main change in the physical properties of the solventproduced by the addition of water is a change in viscosity,which should produce a corresponding alteration in the Conductivityif no other changes occur. The observed effects vary greatly withthe character of the electrolyte, as is seen from the followingdetails.and ethyl 128~ T3 alcohols, andalso in acetone 8* and nitromethane,'s the change in conductivityof uni-univalent salts is of the same order as the change in viscosity,as would be expected if dissociation were approximately complete.(b) Strong acids.Goldschmidt and H. Aarflot 128 and alsoMurray-Rust and Hartleyg2 have shown that the conductivity ofstrong acids in methyl and ethyl alcohols ig decreased to a muchgreater extent than could be expected from the viscosity change.This is probably due to a decrease of the abnormal mobility of thehydrogen ion, and suggests that the greater affinity of the protonfor the water molecule hinders the transference of the proton fromone alcohol molecule to another. In acetone, on the other hand,s4in which the hydrogen ion does not possess an abnormally highmobility, the change of conductivity on addition of water is of thesame order as the change of viscosity.The addition of water to the solution of aweak electrolyte in a non-aqueous solvent practically alwaysincreases the conduct,ivity t,o a much greater extent than couldpossibly be explained by the change in dielectric constant.Thishas been observed for weak acids in the alc0hols,~2~~ 92 and also forweak acids and weak salts in nitromethane and in acet0ne.~4For instance, in nitromethalie the addition of 0.1% of water to a(a) Strong saZts. In methyl 128~(c) Weak electrolytes.REP.-VOL. XXVII. 364 MURRAY-RUST, QATTY, MACPARLANE, AND IIARTLETY‘ :0.002N solution of lithium thiocyanate raises the conductivity bySO%, the decrease of viscosity being only 0.3%.The solvent therefore affects the conductivity of an electrolytedissolved in it in a variety of ways. Yirst, by the magnitude of itsdielectric constant it determines the force of attraction betweenthe ions and the energy needed to separate them.Then, thesolvation of the ions appears to exert a decisive influence on theextent to which they form ion pairs or undissociated molecules,and in this respect the power of the solvent molecules to co-ordinatewith both ions appears to be even more import’ant than their dipolecharacter. And lastly, the mobilities of the ions are determinedby the viscosity of the solvent and by the extent of their solvation.The problem of the immediate future is to discover the precisenature and extent of the solvent atmosphere around the ions whichexerts such an important inflizence on their properties.D.31. MURRAY-RUST.0. GATTY.W. A. MACFARLANE.H. HARTLEY.1 2. phpikal. Chern., 1907, 61, 129; A., 1908, ii, 16. Arch. Teyler, 1900,(2), 7, 59. Phil. Mag., 1907, [vi], 14, 1; A., 1907, ii, 599. 2. Elektro-clzem., 1918, 24, 321; A., 1019, ii, 9. Phil. Mag., 1912, [vi], 23, 551; 1913,[vi], 2!j, 743; A., 1913, ii, 451. Physikal. Z., 1923, 24, 185, 305; A., 1923,ii, 459, 724. “ Elec-trically Conducting Systems,” 1922. “ Raumerfullung und Ionenbeweglich-keit,” 1922.10 “ Uber die Beweglichkeit der Elektrolytischen Ionen,” Portschritte derC‘hemie, 1926. 11 “ Die Elektrolytische Wasseruberfuhrung,” Portschritte derChemie, 1927. l2 “ The Conductivity of Solutions,” 1930. l3 Trans.Puraday SOC., 1927, 23, 334-542. l4 2.ungew. Chem., 1928, 41, 443, 467,1075, 1141; A., 1928, 1320. l5 Ber., 1929, 62, [B], 1091; A., 1929, 764.113 2. Elektrochem., 1930, 36, 861 ; A., 1520. Physikal. Z., 1926, 27, 385;A., 1926, 906. l8 Ibid., 1927, 28, 277; A., 1927, 517. P. Debye and E.Huckel, ibid., 1924, 26, 49; E. Huckel, ibid., p. 204.20 Proc. K . Akud. Wetensch. Amsterdam, 1927, 30, 145; &4., 1927, 626.21 “ Statistical Rlechanics,” 1927; Trans. Paraday SOC., 1927, 23, 434; A.,1927, 1028; PTOC. C’amb. Phil. SOC., 1925, 22, 861. 22 Physikal. Z . , 1924, 25,145; A., 1924, ii, 455. 23 Ibid., 1927, 28, 324; A., 1927, 626; 1928, 29, 78;A., 1928, 590. 24 Proc. Nut. Acad. Sci., 1927, 13, 198; A., 1927, 626.25 Physikal. Z., 1928, 29, 358; A., 1928, 841. 26 Xgl. Dunske Videnskubs.Selsk.Math.-fys. Medd., 1926, 7, [9], 1; A., 1927, 314. 2 7 J. Amer. CJLCI~I.SOC., 1925, 47, 2129; A., 1925, ii, 970. 2s 2.Phvsik, 1924, 24, 56; A., 1924, ii, 456.31 Physikal. Z.,1926, 27, 271; A., 1926, 668. 33 Physikal. Z.,1928,29,121,401; A., 1928,596,957. 34 H. Sack,ibid., p. 627; A., 1928, 1076;B. Brendel, 0. Mittelstaedt, and H. Sack, ibid., 1929, 30, 576; A., 1929, 1240;B. Brendel and H. Sack, ibid., 1930, 31, 345. 35 H. Hellmann and H. Zahn,“ Das LeitvermiSgen der Losungen,” Leipzig, 1924.28 Physikal. Z., 1925, 26, 93.30 J . Amer. Chem. SOC., 1926, 48, 2589; A., 1926, 1208.32 “ Polar Molecules,” 1930"HE ELECTRICAL CONDUCTIVITY OF SOLUTIONS. 355Ann. Physik, 1926, [iv], 80, 191; 81, 711; A., 1926, 778; 1927, 7; H. Zahn,Z .Phyaik, 1928, 51, 350; A., 1929, 512; H. Zahn and H. Rieckhoff, ibid.,1929, 53, G19; A., 1929, 512. 36 .4nn. Physik, 1930, [v], 5, 306; A., 997.37 Z. Physilc, 1929,58,470; A., 1930,36. 38 M. Wien, Ann. Physik, 1924, [iv],73, 161; 1925, [iv], 77, 560; 1927, [iv], 83, 327; 1928, [iv], 85, 795; 1929, [v],1,400; Physikal. Z., 1927,28,384; A., 1924,ii, 142; 1925,ii, 931; 1927, 940;1928, 712; 1929, 401 ; 1927, 244; J. Malsch and M. Wien, Ann. Physik, 1927,[iv], 83, 305. 39 Physikal. Z., 1927, 28, 834; A . , 1928, 244.40 J . Amer. Chem. SOC., 1929, 51, 2950; A , , 1929, 1385. 41 Physikal. Z.,1929, 30, 611; A., 1929, 1389. 42 hTnture, 1930, 126, 994. 43 Phil. Trans.,1900, [A], 194, 321. 44 " Gesammelte Abhandl.," 11, 826. 45 E. W. Wash-burn and J. E. Bell, J.Amer. Chent. SOC., 1913, 35, 177; A., 1913, ii, 177;E. W. Washburn, ibid., 1916, 38, 2431; A., 1917, ii, 10; E. W. Washburn andK. Parker, aid., 1917, 39, 235; A., 1917, ii, 235; 46 W. A. Taylor and S. F.Acree, aid., 1916, 38, 2396, 2403, 2415; A., 1917, ii, 7, 8; H. C. Robertsonand S. F. Acree, J. Physical Chem., 1915, 19, 381; A., 1915, ii, 406. 4 7 J.Arner. Chem. SOC., 1923, 45, 1693; 1926, 48, 1220; A., 1923, ii, 604;1926, 686. 4 8 Ibid., 1928, 50, 1049; A., 1928, 595. 49 Ibid., 1930, 52,1793.50 Ibid., 1919, 41, 1515; A., 1919, ii, 490. 51 2. physikal. Chem., 1925,115, 377; A., 1925, ii, 671. Phil. Mag., 1928, [vii], 5, 1130; A., 1928, 712.s3 J. Amer. Chem. SOC., 1929, 51, 2407; A., 1929, 1161. 54 J., 1913,103, 786.5 5 J. Amer. Chem.SOC., 1922, 44, 2422; A., 1923, ii, 7. 5 6 Ibid., 1923, 45,2017; A., 1923, ii, 722. 57 Ibid., 1930, 52, 1806. 5 8 Ibid., 1924, 48, 312;A., 1924, ii, 304.61 J . Amer. Chem.SOC., 1918, 40, 131; A., 1918, ii, 56. 62 F. Kohlrausch and L. Holborn," Leitvermogen der Elektrolyte," 1916. Trans. Paraday Soc., 1927,23, 351.64 H. Goldschmidt and P. Dahl, Z . physikaE. Chem., 1924, 108, 121 ; 114, 1 ;A., 1924, ii, 235; 1925, ii, 128. 6 5 H. Goldschmidt, and F. Aas, ibid., 112,423; A., 1924, ii, 825; H. Goldschmidt and H. Aarflot, ibid., 1925, 117, 312;A., 1925, ii, 976. 6 7 Proc. Roy.SOC., 1925, [A], 109, 351; A., 1925, ii, 1163. 6 8 Ibid., 1930, [A], 127, 228;A., 703. J., 1930, 2488; A., 1931, 43.70 2. physikal. Chem., 1929, 143, 191; A., 1929, 1239. 71 Ibid., 1921, 99,116; A., 1922, ii, 135. 7 2 J., 1930, 2492. 73 Summarised in " Abstracts ofDissertations," Oxford, 1930, 111, 65 (details to be published shortly). 74 J.Amer. Chem. Soc., 1929, 51, 3312; A , , 1930, 135. 75 2. physikal. Chern., 1906,54, 131; 55, 207; 1907, 58, 479; A., 1906, ii, 149, 335; 1907, ii, 231. 76 J.,1910, 97, 1261. 7 7 J., 1924, 125, 1189. J., 1931, 199. 70 2. physikal.Chem., 1929, 144, 269; A., 1929, 1390.so J., 1931, 215. 81 J., 1928, 3270; 1930, 530; A., 1929, 143; 1930, 545.82 Phil. Mag., 1925, [vi], 50, 971; A., 1925, ii, 1163. 83 2. physikal. Chem.,1926, 123, 429; A . , 1926, 1104. 84 See footnote, p. 340. 85 2. physikal.Chem., 1929, 140, 89; A., 1929, 401. 86 Ibid., 144, 395; A., 1930, 37.8 7 " Das Leitvermogen der Losungen, Vol. I., p. 86. 8 8 See ref. (14), p. 1141.s9 Z . Elektrochem., 1907, 13, 333; d4., 1907, ii, 600.91 J . PhysicalChem., 1925, 29, 973; A., 1925, ii, 871. 92 Proc. Roy. SOC., 1929, [ A ] , 126,84; A., 1930, 160. 93 H. Goldschmidt and H. Aarflot, 2. physikal. Chern.,1925, 117, 312; A., 1925, ii, 976. 94 J. Physical Chem., 1929, 33, 190, 1495;A., 1929, 401, 1390. B5 J. Amer. ('hem. SOC., 1926, 48, 2068; A., 1926, 906.@a Ibid., p. 1861; A , , 1926, 1006. g 7 J. Physical Chem., 1925, 29, 973; A,,50 Ibid., 1927, 49, 636; A., 1927, 421.6o Z . physikal. Chem., 1923, 108, 49; A., 1923, ii, 723.6 6 Ibid., 1924, 114, 275; A., 1925, ii, 208.90 J . Amer. Chem. SOC., 1923, 45, 2017; A., 1923, ii, 722356 THE ELEUTRICAL CONDUCTIVITY OF SOLUTIONS.1925, ii, 871. g 8 E. C. Righellato and C . W. Davies, Trans. Faraday SOC., 1930,26, 592; A , , 1371. Og Phil. Mag., 1927, [vii], 4, 300; A., 1927, 941.lol See ref. (62), p. 213. lo2 J.Amer. Chem. SOC., 1909, 31, 322. lo3 J., 1902, 81, 456. lo4 Phil. Trans.,1906, [A], 205,449; A., 1906, ii, 329. lo5 D. A. MacInnes and T. B. Brighton,,J. Amer. Chem. SOC., 1925, 47, 994; E. R. Smith and D. A. MacInnes, ibid.,p. 1009; A., 1925, ii, 542. lo6 Ibid., 1920, 42, 1117; A., 1920, ii, 466.I o 7 Trans. Paraday Soc., 1927, 23, 400; A., 1927, 1031. lo8 J. H. Wolfenden,E. P. Wright, N. L. R. Kame, and P. S . Buckley, ibid., p. 491; A., 1927, 1027.lug Ibid., 1930, 26, 625; A., 1525.110 Phil. Mag., 1925, [vi], 50, 729; A., 1925, ii, 1061. ll1 J. Amer. Chem.SOC., 1922, 44, 2411; A., 1923, ii, 7. 112 Ibid., 1914, 36, 1630; A., 1914, ii,704. 113 Amer. Chem. J., 1904, 32, 409; A., 1905, ii, 8. 114 J. R. Partingtonand G. F. Isaacs, Trans. Paraday SOC., 1929, 25, 53; A., 1929, 269. 115 2.physika2. Chem., 1926, 122, 149; A., 1926, 911. 116 J. Amer. Chem. SOC.,1925, 47, 92; A., 1925, ii, 542. 117 Phil. Mag., 1931, [vii], 11, 222. 118 J.,1928,524; A., 1928, 370. 119 A. Unmack and E. Bullock (see footnote, p. 340).lZo 2. Elektrochem., 1928, 34, 546; A., 1929, 143. lZ1 Ibid., 1922, 28, 161.lZ2 2. physikal. Ckm., 1925, 118, 161; A,, 1926, 128; Trans. Faraday SOC.,1927,23, 381; A., 1927,1032; H. Remy and H. Reisener, 2. physikal. Chem.,1926, 124, 41; A., 1926, 1201. Rec. trav. chim., 1923, 42, 229, 533; A.,1923, ii, 288; 532. 124 J., 1929, 2095; A., 1929, 1239. 2. Physik, 1920,1, 221 ; A., 1920, ii, 527. 126 " Electronic Theory of Valency," 1927. 137 K.Fajans and G. Joos, 2. Physik, 1924, 23, 1 ; A,, 1924, ii, 372. lZ8 Z . physikal.Chem., 1926,122, 371 ; A., 1926, 1005. lZ9 H. Goldschmidt and A. Thuescn,ibid., 1912, 81, 30; A., 1912, ii, 1154.loo Ibid., 1928, [vii], 5, 199; A., 1928, 244

ISSN:0365-6217    

DOI:10.1039/AR9302700326

出版商:RSC    

年代:1930

数据来源: RSC

摘要:

INDEX OF AUTHORS’ NAMES.AARFLOT, H., 353, 355.Aas, F., 355.Abbiate, R., 211.Ab6, H., 80.Abel, E., 79.Acree, S. F., 213, 225, 336,Adam, N. K., 34.Adams, E. Q., 324.Adams, L. H., 56, 336.Adams, R., 95, 163, 240.Adhikari, G., 36.Adkins, H., 91.Adolph, W. H., 302.Agostini, P., 211, 212.Ahaqoni, J., 38.AhlfeId, F., 294.Ahlstrom, L., 99.Ainley, A. D., 133.Akabori, S., 184.Albrecht, (Frl.) E., 314.Albrecht, H., 150.Alder, K., 86, 88, 89.Alekseevski, K. V., 223.Alfoldy, Z. von, 227.Alimarin, I. P., 212, 214.Allan, J., 137.Allen, C. F. H., 222.Allen, F. J., 55.Allen, I., 192.Allen, J. F., 54.Allen, V. T., 299.Allison, F., 203.Allmand, A. J., 39, 44.Alphen, J. van, 141.Alyea, H. N., 42, 45.Amelotti, L., 79.Ames, 0.C., 217, 220.Amstutz, K. L., 222.Anderson, J. S., 75.Anderson, R. J., 266.Andes, L., 58.Andreatta, C., 301.Andrdevski, I. A., 76, 91.Andrbs, L., 80.Andress, K. R., 33.Andrews, J. C., 226.Andrieux, L., 62, 68.Andronikova, N. N., 216.Angel, H. R., 239.Angeli, A., 169.Angell, F. Q., 77, 164.355.Ansbacher, S., 215.Anson, M. L., 268, 267.Antelmann, H., 67.Antropoff, A. von, 78.Arbes, A., 60.Armit, J. W., 185Armstrong, H. E., 304.Arndt, F., 180.Arvin, J. A., 94.Asahina, Y., 190, 191, 202.Asai, K., 232.Asano, M., 202.Askew, F. A., 277.Askey, P. J., 44.Assarson, G., 60.Aston, F. W., 52, 53, 307, 310, 315,Astruc, A., 217.Atkins, W. R. G., 303.Atkinson, R. d’E., 309.Ato, S., 218.Aubel, E. van, 54.Austin, W.C., 102.Avery, J., 103.Avery, S., 223.316, 319.Babcock, H. D., 306.Babers, F. R., 267.Baborovsky, G., 352.Bachmann, W. E., 167.Backer, H. J., 162, 219.Backer, M. L., 79.Bader, G., 74.Bader, J., 128.Badger, R. M., 30.Backlin, E., 323, 324.Baor, E., 99.Bailar, J. C., iun., 115, 120.Bailey, C. R:,i9, 30, 79.Baines, H., 58.Baker, J. W., 134, 135, 136, 147, 164. _ . I .Baker; W., 179.Balandin, A. A., 37, 210.Baldwin, C., 84.Baldwin, M. E., 111.Balfe, 31. P., 149.Ball, R. W., 63.Balz, G., 73Bamberger, E., 170.Banchi, G., 62.36358 INDEX OF AUTHORS' NAMES.Uannister, L. C., 55.Barak, M., 338, 350.Barat, T. P., 79.Barber, H. H., 218.Barbieri, G. A., 75.Barbour, A. D., 263.Bardhan, J. C., 85.Bargellini, G., 174, 178.Barnes, J.W., 215.Barratt, S., 21.Barrett, H. S. B., 183.Barrett, W. H., 336.Barth, T. F., 299.Bashenova-Koslovskaia, L. J., 98.Bassett, H., 61, 75.Bassett, H. P., 348.Bateman, A. M., 284.Bates, J. R., 50.Battegay, M., 132.Batuecas, T., 53.Baudisch, O., 302.Bauer, L. H., 297.Baumann, E., 129.Baumeler, C., 271.Baumgarten, P., 212.Baxter, G. P., 308.Baxter, W. P., 16, 24.Bay, Z., 66.Beattie, J. A., 347.Becker, E., 74.Becker, H., 307Bedford, M. H., 228.Beecher, H. U., 309.BBhal, A., 156.Behr, A., 202.Beltik, A., 227.Beliankin, D., 298.Bell, E. V., 149, 157, 138, 150.Bell, F., 136, 139, 140.Bell, J. E., 355.Bender, I., 232.Benedetti-Pichler, A., 208.Benedict, S. R., 266.Benedict, W.S., 78.Bennett, G. M., 146, 148, 149, 152,Benrath, A., 79.Berg, R., 215, 216.Berger, F., 193.Berger, K., 67.Bergmann, E., 91.Bergmann, M., 108, 112.Berl, E., 77.Berman, H., 296, 300.Bermann, L., 161.Bernasconi, E., 227.Berner, E., 110.Bersch, 3%. W., 195.Berthoud, A., 47.Bertrand, 102.Besson, H., 224.BBtim, A. P. L., 292.Reutler, H., 24.157, 158, 159, 166, 180, 186.Bewilogua, L., 31.Biazzo, R., 213.Biedermann, H., 82.Bierry, H., 222.Bigelow, N. M., 125.Bigwood, E. J., 268.Biltz, H., 216.Biltz, W., 62, 76, 215.Bini, G., 303.Birckenbach, L., 64.Bird, 0. D., 216.Birge, R. T., 22, 62, 306, 307, 323.Birkinshaw, J. H., 230, 231, 233, 234,Birr, E. J., 327, 339, 350.Bischoff, C. A., 190.Bishop, L.R., 245.Bito, K., 299.Bjerrurn, N., 145, 326, 327, 333, 362.Bjijrkstbn, J., 247.Blakey, W., 139, 141.Blanchetibre, A., 217.Blanchon, H., 100.Blasberg, K., 61.Blaschko, H., 259.Blaustein, W., 219.Blbger, J., 223.Blicke, F. F., 126.Blount, B. K., 189.Bliimmel, 106.Blumentritt, M., 334.Blumstein, S. N., 221.Bodenstein, A., 132.Bodenstein, M., 43, 53.B&k, F., 225.Bdeseken, J., 97, 162.Boehm, G., 258.Bdhm, J., 205.Bijrner, K., 127.Bogdanov, I. F., 56.Bogoiavlenski, L. B., 311.Boivin, A., 223.Boldyreff, A. W 215, 216.Bolinger, M. G.,'kO, 51.Bollinger, G. M., 336.13012, F., 113.Bone, W. A., 44.Bonhoeffer, K. F., 23, 46.Bonneau, L., 218.Boogaert, H. L., 225.Boord, C. E., 83.Booth, H.S., 59.Borchert, H., 284.Borkowsky, F., 107.Born, M., 15, 23, 352.Borovik, S. A., 79Borsche, W., 132, 150.Bothe, W., 320, 322.Bott, H. C., 103, 104.Bouisson, (Mlle.) N., 217.Bourdillon, R. B., 277.Bourguel, M., 84, 98.Bouwman, J. H. H., 221.235, 237INDEX OF AUTHORS’ NAMES. 359Bovalini, E., 302.Bowden, F. P., 37.Bowen, E. G., 54.Bowen, E. J., 24, 44.Bowen, N. L., 80, 285.Bowman, J. R., 251.Boyland, E., 264.Braddick, H. J. J., 312.Bradley, W., 172.Rrady, F., 170.Bragg, (Sir) W. H., 33.Bragg, W. L., 287.Branch, G. E. K., 128, 160.Braun, E., 95, 105.Braun, J. von, 143, 182, 190.Brauner, B., 219.BrdiEka, R., 75.Breckenridge, J. G., 163.Bredereck, H., 108.Brendel, B., 354.Brestak, L., 211.Brewer, A.K., 49.Briggs, G. H., 313.Briggs, T. R., 57, 78.Brighton, T. B., 356.Brigl, P., 102.Briner, E., 60.Briscoe, H. T., 344.Britton, G. T., 39.Britton, H. T. S., 70.Britton, S. C., 55.Broadway, L. F., 48.Bronsted, J. N., 51, 14’7.Bronitsky, J., 222.Bross, J., 56, 67.Brouty, J., 120.Brown, C. L., 65.Brown, M. H., 219.Browning, E., 163.Bruce, H. M., 277.Bruch, E., 113.Bruchhausen, F. von, 193.Bruckner, A., 60.Brukl, A., 62, 65.Brunner, M., 92, 93.Brunner, R., 75.Bruns, B., 40.Bruylants, P., 86.Bryans, F., 142.Buck, J. S., 192, 197.Buckley, P. S., 356.Buddington, A. F., 203.Bulow, C., 174.Buttner, K., 322.Bullock, E., 340, 356.Burger, G., 226, 227.Burgess, W. M., 56.Burk, D., 242, 243.Burkser, E., 219.Burkser, E.S., 59.Burmeister, W., 11 1.Burns, J., 142.Burstall, F. H., 69, 181.Burstein, R., 40.Burt, F. A., 295.Burton, H., 87, 128.Busch, F., 57.Busch, G., 340, 341, 360.Butenandt, A., 271, 272.Butkovitsch, V. S., 232, 233, 247.Butler, K. H., 60.Butterworth, A. J., G G .Cady, G. H., 71, 80.Cady, H. P., 309.Caldwell, W. F., 220.Caley, E. R., 211, 218, 219.Calingeart, G., 224.Callan, T., 215.Calvert, J. T., 205.Calvery, H. O., 266.Cameron, F. K., 78.Cameron, G. H., 322.Camp, W. H., 256.Campbell, E. G., 240.Campbell, F. H., 214.Candlin, E. J., 251.Cannizzaro, S., 171.Capper, N. S., 276.Cario, G., 48.Carletti, O., 222.Carothers, W. H., 94.Cam, E. P., 84Carribre, E., 221Casares, J., 221.Caspari, W.A., 145.Cassie, A. B. D., 30.Cattelain, E., 215.Cauquil, G., 115.Cave, H. M., 312.Cavinato, A., 296.Cawley, C. M., 88.Chadwick, J., 18, 314, 315, 319, 320,321.Challenger, F., 132,133,233,235,236.Chan. 53.Chapiin, R., 30.Chapman, A. W., 121.Chapman, D. L., 43.Chardonnens, L., 141.Chargaff, E., 266.Charles, J. H. V., 230, 234, 236.Charmandarian, M. O., 211.Chattaway, F. D., 155, 159, 224.Chauvenet, E., 65.Cherbuliez, E., 215.Chernoff, L. H., 225.Chessman, G. H., 72.Childs, W. H. J., 30.Chiles, H. M., 151.Chines, C., 213.Chittum, J. F., 55.Choay, E., 156.Chomse, H., 66.Chudoba, K., 285, 298, 299360 INDEXClaisen, L., 123.Clarke, H. T., 223.Clarke, B. L., 227.Clarke, L., 79.Clemo, G. R., 85, 169, 187.Clos, H., 214, 216.Clusius, K., 46, 68, 71.Clutterbuck, P.W., 237.Cocker, W., 148.Cocosinschi, A., 58.Coffin, C. C., 67, 86.Cohen, E., 67.Cohen, F. H., 132.Cohn, E. J., 273.Cohn, W. M., 54.Colla, C., 57.Collin, E. M., 227.Collins, A. D., 133.Cologne, J., 101.Conant, J. B., 126, 127, 270.Condon, E. U., 317, 319.Conrady, A. E., 208.Cooper, A. J., 66.Copley, E. D., 337, 338.Copping, A. M., 281.Coppock, P. D., 238.Corbellini, A., 236.Corlin, A., 322.Cornelius, H. P., 297.Corsi, A., 226.Cosslett, V. E., 47.Cotelle, (Mme.) S., 310.Courtman, H. R., 338.Cowperthwaite, I. A., 347.C o p e , F. P., 237.Creedon, T. V., 135.Cremers, L., 79.Crespi, M., 39.Crockford, H. D., 78, 81.Cross, H. C., 78.Croucher, H.H., 61, 75.Csatt6, T., 249.Cuny, L., 225.Curie, (Mlle.) I., 310, 312.Curie, (Mme.) P., 310, 311.Cutler, D. W., 244.Cuvelier, V., 217, 295.Czapek, F., 245.Dadieu, A., 87.Dadswell, H. E., 141.Dafert, 0. A., 221.Dahl, P., 343, 455.Dakin, H. D., 238, 274.Dale, H. H., 275.Dalton, R. H., 46.Dambergis, C., 102.Damiens, A., 64, 72.Danilov, S., 115, 119.Danneel, R., 160.D’Ans, J., 57, 79Darkis, F. R., 84.OF AUTHORS’ NAMES.Darling, S. F., 202.Darmois, E., 162.Das-Gupta, P. N., 211, 217.Das-Gupta, R. N., 218.Datta-Ray, B. K., 217.Daugherty, J. F., 30.Dauvillier, A., 12.Davidson, A. W., 78.Davidson, S. C., 296.Davies, A. R., 266.Davies, C. W., 327, 336, 337, 343,345, 346, 356.Davies, J. G., 281.Davis, R: M., 197.Dawson, H.M., 146, 147.Dawson, L. E., 202.Day, W. N., 286.De Boer, J. H., 56, 65.Debye, P., 16, 31, 32, 326, 328, 331,333, 334, 354.De Carvalho, H., 302.Dede, L., 61.De Finhly, I., 294.De Gruyter, J., 66.De Haas, G., 221.De Haas, W. J., 54, 77.De Hemptinne, M., 23.Deines, 0. von, 69.Deinum, H. W., 67.De Jongh, S. E., 272.De Lapparent, J., 295.De La Roche, B., 226.Delaville, M., 217.Delbruck, K., 104.Del Campo, A,, 213.Del Fresno, C., 227.De Loureiro, J. A., 226.Demmer, E., 178.Demole, V., 277.Dempster, A. J., 12.DenigBs, G., 211, 222.Denison, R. B., 347.Dennis, L. M., 65.Dennler, W. S., 115, 1%).Dennstedt, I., 127.Dent, (Miss) B. M., 16.Derry, D. R., 294.De Rudder, F., 74, 82.Desai, R.D., 135.De Saint-Aunay, R. V., 91, 92.Deubel, F., 297.Deubner, A., 334.Deulofeu, V., 102.Deuticke, H. J., 260, 2G2,Deutsch, D., 41.De Veer, J. R. G., 224.Dewar, (Sir) J., 312.D h M , C., 271.Dick, J., 215.Dickinson, R. G., 24, 164.Dieke, C. H., 306.Diels, O., 86, 88, 89.Dillon, R. T., 83INDEX OFDingemanse, E., 272.Dirac, P. A. M., 325.Dirscherl, W., 95.Dittler, E., 296, 297.Ditz, H., 221.Dixon, J. K., 38.Dixon, M., 256.Dmochowski, A., 261.Dobbins, J. T., 217.Dobretsberger, H., 38.Doisy, E. A., 272.Dole, M., 335.Dolgov, K. A., 212.Donat, K., 314.Donath, E., 214, 295.Donau, J., 219.Donnay, J. D. H., 285.Donovan, P. P., 110, 111.Dorfmiiller, G., 223.Dorfmiiller, T., 271.Dorough, G.L., 94.Dorrer, E., 91.Dorronsoro, J., 226.Dosios, K., 224.Drake, N. L., 222.Drew, H. D. K., 77, 164, 207.Druce, J. G. F., 52.Drucker, C., 348.Drumm, P. J., 135.Drummond, J. C., 276, 281.Du Bois, R., 39.Dubsky, J., 211.Duclaux, J., 70.Dudley, H. W., 275.Diirr, W., 113.Dtising, J., 76.DuliBre, W. L., 276.Dunaev, A. P., 221.Dunlap, A. A., 240.Duparque, A., 303.Durham, E. J., 79.Dutoit, 338.Dutoit, A. L., 292.Dyckerhoff, H., 255.Dykstra, H. B., 83.Eardley-Wilmot, V. ., 286.Eastwood, (Miss) F. M., 179.Ebert, F., 77.Eccott, E. N., 101.Eckert, F., 120.Eddington, (Sir) A. S., 323, 324.Eddy, C. E., 205.Eddy, W. H., 280.Edgar, G., 224.Edsall, J. T., 256, 257.Edwards, W. A. M., 55.Efremov, N. N., 292.Egloff, G., 82.Egnbr, H., 221.Ehmann, E.A., 295.Ehrenfest, P., 31.AUTHORS' NAMES.Ehrhardt, F., 31.Ehrlich, F., 232, 251, 263.Eibeler, H., 255.Eichenberger, E . , 17 1.Eichler, H., 213.Eigenberger, E., 90.Eisenhut, O., 79.Eisenlohr, F., 160.Eisenschitz, R., 16.Ekkert, L., 221.Elder, L. W. jun., 227.Elliott, A., 31, 307.Ellis, C. D., 315.Ellis, D., 303.Ellis, J. W., 30.Ellsworth, H. V., 298.Elsdon, G. D., 224.Elsen, G., 317.Elsner, H., 110, 111.Elstner, G., 69.Embden, G., 260, 262.Emde, H., 199.Emerique, L., 277.Emerson, H., 223.Emmens, H., 56.Emmerie, A., 215.Engel, E. W., 211.Engel, H., 248, 249.Englis, D. T., 286.Englund, B., 97.Enk, E., 76.Ensslin, F., 64.Ephraim, F., 75, 215.Epsteh, S., 78.Erbacher, O., 60, 219.Erdmannsdorffer, 0.H., 299.Erdas, J., 226.Erikson, S., 224.Escher, H. H., 167.Estermann, I., 12.Ettinger, J., 227.Euler, E., 105.Euler, H. von, 224, 277, 302.Evans, J. T., 87, 88.Evans, M. W., 127.Evans, U. R., 55.Everett, M. R., 267, 268.Evlampiev, V. V., 99.Evrard, V., 215.Ewald, L., 127, 128.Eyring, H., 19.Faber, H., 57.Fabrich, K., 210.Faermann, G. P., 77.Faessler, A., 205.Fahl, B. E., 213.Faillebin, M., 210.Fairbourne, A., 96.Fairchild, J. G., 221.Fairhall, L. T., 226.Fajans, K., 314, 352, 356.M 236862 INDEX OFFalk. E.. 78.Falkenhagen, H., 334, 335.Faltis, F., 61, 161, 194.Farkas, A., 49.Farkas, L., 23, 46, 47.Farmer, E. H., 85, 86, 87, 88, 89,Fast, J. D., 65.Fau, M., 67.Fawcett, E. II., 213.Fawcett, R.C., 199.Feather, N., 314.Federov, M. W., 232, 233.Fedorova, A. N., 76.Feigl, F., 211, 212, 213, 216.Feit, W., 73, 93.Feitknecht, W., 61.Feldmann, L., 99.Feldmann, R. W., 219.Felkers, P. F., 220.Fellenberg, T. von, 223.Fenner, C. N., 315.Fenton, G. W., 143.Ferguson, A., 340, 346.Ferrari, A., 57, 78, 297.Fichter, F., 68, 72.Finch, G. I., 49.Finn, A. N., 214.Fischer, E., 103, 104.Fischer, F. H., J69.Fischer, H., 210.Fischer, H. 0. L., 99.Fisher, L. W., 295.Fisher, (Miss) N. I., 187.Fiske, C. H., 261.Flaherty, G. H., 293.Flaschentriiger, B., 223.Fleischhaus, Z., 210.meitmann, T., 59, 93.Fleming, R., 222.Fletcher, L., 227.Fleury, P., 225.Fleysher, M.F., 348.Fliirscheim, B., 134, 135, l3G, 146,Foldi, Z . , 86.Foerster, F., 67.Folberth, W., 126.Font&, G., 268.Fookey, W. L., 99.Foote, H. W., 38, 78, 80.Forjas, A. P., 302.Forscey, L. A., 72.Forsyth, R., 142.Fort, R., 43, 44.Foshag, W. F., 203.Foster, W., 67.Fowler, R. H., 342.Fox, (Miss) D. L., 142.Franz, H., 320.Fragner, J., 134.Frahm, E. D. G., 225.Francis, F., 253.153.147.AUTHORS’ NAMES.Franck, J., 20, 22, 23.Franqois, M., 61.Franke, W., 70.Frankenburger, W., 48, 49.Frankenstein, W., 80.Franz, H., 54.Fraser, C. G., 38.Frauendorfer, H., 194.Frazer, J. C. W., 37.Frazer, J. E., 337, 350.Fredga, A., 146, 181.Preise, F. Tt7., 292.Freitag, K., 314.Freizlrel, J., 35.Freudenberg, K., 104, 106, 113.Freudenberg, W., 108.Freundlich, H., 41, 152.Frey, K., 110.Frick, H., 285.Fricke, R., 80, 216, 351.Friedrich, H., 160.Friend, J.A. N., 63, 77.Friese, H., 113.Fritz, H., 214.Fromageot., C., 10 1.Frumlcin, A., 40.Fuchs, P., 214.Fiirth, R., 324.Fulde, A., 185.Funke, G., 77.Furman, N. H., 200, 210.Gabriel, S., 188.Gadamer, J., 196.Gaddum, J. H., 275.Gaddy, U. L., 80.Gaertner, H. R. von, 300.Gagarin, R. P., 126.Call, H., 75.Gamble, E. L., 69.Gamow, G., 26, 314, 317, 318, 319,Gams, 192, 397.Gane, R., 145, 163, 154.Gard, E. L., 214.Garner, W. E., 47, 5s.Garrick, F. J., 54.Gaubert, P., 298.Caviola, E., 25.Gedney, E. K., 296.Geiger, H., 312.Geigle, W. F., 57.Ceilmann, W., 74.Gentile, G., 17.Gerasimov, I., 70.Gerckc, A., 100.Oerding, H., Gci.( h l a c h , W., 2OG.German, W.L., 70.Getman, I?. I€., 34(i, 345.Ghosh, J. C . , 47.Ginnnotti, hT., W .320INDEX OF AUTHORS’ NAMES. 363Giauque, W. F., 306.Gibbons, V. L., 346, 348.Gibson, C. H., 45.Gibson, C. S., 166, 181, 201.Gibson, D. T., 180.Gibson, R. F., 56.Giese, H., 65.Gilbert, F. L., 150.Gilbert, R., 105.Gilchrist, R., 219.Gillson, J. L., 295.Gilman, H., 222.Gimingham, C. T., 241.Gindraux, L., 138.Ginsberg, H., 220.Glasstone, S., 217.Glockler, G., 92.Gloy, H., 341.Go, J., 196.Godchot, M., 115.Goebel, W. F., 235, 267.Gorlacher, H., 67.Goldach, A,, 68, 72.Golding, J., 281.Goldschmidt, H., 337, 338, 343, 344,353, 355, 356.Goldschmidt, S., 128.Goldschmidt, V.M., 304.Golse, J., 214, 219, 220, 222.Gomberg, M., 115, 127.Gombinska, F., 115.Gonyer, F. A., 300, 304.Goodeve, C. F., 31.GOOS, F., 103.Goralevitsch, D. K., 75.Goranson, E. A., 296.Gorbatschev, S. V., 221.Gortikov, V. M., 227.Goss, F. R., 134.Goto, K., 196, 198.Gottfried, C., 297.Gottschalk, A., 232.Gouzon, B., 222.Grace, N. S., 60.Graham, R. P. D., 208.Graham, S. B., 85.Grard, J., 101.Grassmann, W., 255.Graton, L. C., 292.Gray, L. H., 323.Green, H. N., 167.Green, J. R., 213.Greengard, H., 123.Greenwald, I., 266.Greenwald, J. A., 57.Greer, (Miss) E. J . , 63.Gregorini, B., 236.Gregory, C. H., 214.Gregory, F. G., 240.Creinacher, H., 312.Greiner, E. S., 79.Grigg, P. P., 43.Grignard, V., 90, 200, 101.Grigoriev, A.T., 7 7 .Groesbeck, E. C., 78.Groger, R., 151.Groll, E., 74.Gronwall, T. H., 332, 333.Groocock, (Miss) C. M., 146.Grosse, A. von, 68, 212, 310, 317.Grossmann, 0. von, 214.Grossmann, P., 100.Grove, C., 51.Groves, L. G., 141.Griinberg, A. A., 77.Griintuch, R., 244, 245.Gruhl, A., 75.Gruner, J. W., 286.Guempel, (Mlle.) O., 78.Guha, B. C., 281.GuimarBes, D., 296.Guisen, D., 294.Gull, H. C., 139.Gulland, J. M., 182, 183, 202, 2G7.Gurevitsch, V. G., 220.Gurin, S., 280, 281.Gurney, R. W., 317, 319.Guzrnan, J., 226.Haar, A. W. van der, 223.Haas, D., 84.Haber, F., 46.Hadow, H. J., 339.Hiigg, G., 78.Hagen, H., 56, 68.Hague, E. N., 82.Hahn, A., 53.Hahn, F. L., 62, 212, 213, 214, 215,216, 227.Hall, R.E., 336.Hamasumi, M., 78.Hamer, (Miss) F. M., 186, 187.Hammick, D. L., 63, 69, 120, 130.Hanford, Z. M., 304.Hanhart, W., 143.Hansen, R., 59.Hanssen, R., 216.Hantzsch, A., 67, 71, 77, 100.Hazaldsen, H., 286.Harbich, E., 296.Harden, A., 264.Hardy, L. V., 214.Htiri, P., 266.Harington, C. R., 274,Harned, H. S., 348.Harper, G. I., 312.Harris, E. E., 213.Harrison, J. V., 293.Hart, H. B., 348.Harteck, P., 46, 47, 49, GG.Hartley, (Sir) H., 336, 337, 338, 339,Hartung, W. H., 201.Harvey, J., 17 I.Hashimn, H., 109.343, 344, 345, 348, 350, 353364 INDEX OF AUTHORS' NAMES.Hatcher, W. H., 224.Hattori, S., 172, 177.Haugen, H. W., 213.Haught, J. W., 220.Haughton, J. L., 79.Hawkins, L.A., 240.Haworth, R. D., 169, 192, 19G, 197.Haworth, W. N., 102, 103, 104, 105,Hayashi, M., 124.Hayes, N., 111.Hayman, D., 223.Head, F. S. H., 178.Heathcoat, F., 162.Hecht, I?., 218.Hecht, O., 102.Heck, L. L., 222.Heczko, T., 227.Hedfeld, K., 30.Hefter, J., 262.Heidelberger, M., 109, 235.Heilbron, I. M., 171, 277.Heinz, H., 295.Heinz, W., 217.Heitler, W., 14.Helfenstein, A,, 167, 16s.Helferich, B., 96, 104.Heller, K., 210, 214, 221.Hellmann, H., 354.Hellstrom, H., 224.Henderson, J. A. R., 215.Henderson, S. T., 250.Henglein, F. A., 73.Henley, (Miss) R. V., 142.Heme, A. L., 88.Henri, V., 24, 30, 31.Henriques, R., 122.Hensel, W. G., 110, 111.Heme, M., 270.Hernette, A,, 67.Hernler, F., 223, 271.Herrmann, Z., 60, 217.Hertogh, (Miss) W., 66.Herzberg, G., 22, 52, 306.Herzfinkiel,H., 311.Xess, F.L., 297.Heas, K., 113.Hess, V. F., 312, 322.Hessler, W., 61.Heasling, G. von, 75.Hetherington, A. C., 230, 234, 286,Heuer, W., 110.Heukeshoven, W., 70.Hevesy, G. von, 61, 65, 205.Hewett, D. F., 293.Hey, D. H., 201.Hey, M. H., 297.Hickinbottom, W. J., 107, 124.Hieber, W., 74.Higginbottom, (Miss) C., 133.Hilbck, H., 222.Hildebrand, J. H. 71, SO.107, 263.237.-3il1, A. E., 80.3311, A. V., 258.Till, S. G., 44.limberg, I., 247.linsberg, K., 221.linsberg, O., 158.linshelwood, C. N., 43, 44, 35, 46,lintermaier, A., 127.lirst, E. L., 103, 104, 2G3.loag, L. E., 226.Hocart, R., 295.Hock, A. L., 148.Hodgson, H.H., 132, 139.Holtje, R., 67.Honigschmid, O., 53.Hofeditz, W., 125.Hoff, J. H. van 't, 161.Hoffer, M., 90.Hoffman, G., 322.Hoffman, J. J., 218.Koffmann, H., jun., 226.Hofmann, K. A., 66.Hofmann, R., 221.Hofmann, V., 74.Holborn, L., 347, 355.Holland, H. C., 78.Holleck, L., 55.Hollemann, A. F., 138.Holloway, J., 149.Holmes, A., 310, 316.Holmes, B. E., 262.Holmes, E. L., 134, 135, 136, 139.Holmes, T., 47.Holt, D. A., 226.Holt, M. L., 227.Holtz, F., 279.Holwech, W., 219.Honda, J., 191.Honda, K., 80.Hopff, H., 113.Hopkins, (Sir) F. G., 255.Hopton, G. U., 202.Horne, A. S., 240.Horst, (Miss) H. van der, 68.Houtermans, F. G., 309, 318.Hove, H. vom, 127.Howe, M., 273, 274.Howell, 0. R., 31.Howells, W.J., 80.Howlett, L. E., 64.Hudson, C. S., 103, 105, 108, 109.Hiickel, E., 17, 326, 328, 331, 333,351, 354.Huckel, W., 153, 160.Hiittig, G. B., 60, 62, 63, GS, 74,Hughes, 0. L., 348.H u h , C. D., 292.Hulmaier, J., 294.Hulse, R. E., 65.Hummel, J., 239.Humphrey, W. C., 270.99.75INDEX OF AUTHORS’ NAMES. 365Hunt, H., 344.Huntingdon, A., 133.Hurd, C. D., 82, 92, 123.Hurd, L. C., 58.Hutchison, W. K., 99.Huttner, K., 64.Iljinski, V. P., 78.Illari, G., 223.Illingworth, W. S., 130.Tnganni, A., 78.Ingold, C. K., 51, 85, 87, 117, 128,130, 134, 135, 136, 138, 139, 143,145, 146, 148, 151, 153, 154, 161.Ingold, (Mrs.) E. H., 139.Inoue, T., 59.Inubuse, M., 190, 191.Ionesco-Matiu, A., 224.Ionescu, M. V., 222.Ipatiev, V., 56.Irvine, (Sir) J.C., 109.Isaacs, G. F., 348, 356.Isbell, H. S., 59.Ishimaru, S., 308.Itallie, L. van, 222.Ivanov, J. A,, 69.Ivanov, P. T., 303.Jackson, A., 146.Jackson, E. L., 103.Jackson, K. S., 63.Jackson, L. C., 48.Jacobsen, J. C., 310.Jacobson, C. A., 220.Jacobus, W., 126.Jiinecke, E., 78, 80.Jakbb, W. F., 70.Jakovlev, K. P., 52.Jander, G., 67, 70, 228.JaneEek, G., 302.Jansen, (Miss) A. F. J., 68.Jansen, B. C. P., 281.J h s k y , A., 227.Janssens, 221.Jantsch, G., 63.Javillier, M., 277.Jaxon-Deelman, J., 150.Jay, M. S., 240.Jean, 215.Jelley, E. E., 213.Jellinek, K., 78.Jenkins, F. A., 300.Jenkins, R. G. C., 277.Jenkinson, J. A., 139.Jessop, J. A., 143, 151.Jette, E., 220.Jilek, A., 216, 219, 226.Joassart, N., 227.Jodidi, S.L., 240.Johnson, A. H., 213.Johnson, C. R.. 53.Johnson, F. R., 177.Johnson, H. J., 187.Johnson, J. D. A., 181.Johnson, J. R., 178.Johnson, T. B., 267.Johnson, T. H., 12.Johnson, W. C., 62, 220.Johnston, H. L., 306.Johnstone, H. F., 30.Joliot, F., 310.Joly, J., 311.Jones, B., 215.Jones, E. T., 108.Jones, G., 335, 336.Jones, H. C., 348.Jones, T. G., 182.Jones, T. R., 220.Jones, W. I., 141.Jones, W. M., 80.Joos, G., 334, 356.Jorpes, E., 108.Josephs, R. C., 336.Josephson, K., 104.Jouniaux, A., 50.Joy, W. E., 335.Jucaitis, P., 80.Juliusberger, F., 41.Justi, E., 66.Juza, R., 76.Kahane, E., 218.Kahlenberg, L., 227.Kalhann, H., 16, 19, 5.0.Kama, J.E., 295.Kameda, T., 227.Kameyama, N., 299.Kanao, S., 201.Kane, N. L. R., 356.Kanematsu, T., 202.Kapeller-Adler, R., 249.Kaplan, J., 48.Kapulitzas, H. J., 21 1.Karaoglanov, Z . , 2 15.Karrer, P., 109, 167, 168, 173, 277.Kary, C. von, 103.Kasatkina, I. A., 221.Kaschtanov, L., 68, 304.Kassler, R., 75.Kassner, J. L., 66.Kato, Y., 73.Katzenstein, (Mlle.) M., 215.Kaupp, E., 79.Kawagoye, M., 176.Kawai, K., 215.Kawai, S., 222.Keep, F. E., 296.Keersbilck, N. van, 86.Keesom, W. H., 16, 68.Keim, R., 64.Kellett, E. G., 155, 159.Kemmerer, G. I., 58.Kemula, W., 92366 INDEX OF AUTHORS' NAMES.Kendall, E. C., 254.Kendall, F. E., 109, 151.Kenner, J., 141.Kenyon, J., 139, 140, 149.Keresztesy, J., 280.Kermack, W.O., 184.Kern, E. F., 220.Kerr, P. F., 299.Kershaw, A., 132.Kharasch, M. S., 59, 84.Kikuchi, S., 12.Kiliani, H., 106.Kimmelstiel, P., 224.Kindler, K., 146.Kjng, A. S., 52, 306, 307.King, C. V., 220.King, H., 225.King, H. J. S., 58.Kinnersley, 2 8 1.Kipping, F. B., 189.Kirschfeld, L., 77.Kisch, B., 261.Kistiakowsky, G. B., 21, 23, 42, 44,45.Kitasato, Z., 196.Klaassens, K. H., 219.Klanfer, K., 216.Klatschkin, F. M., 76.Klein, G., 248, 249.Klein, L., 233, 235, 236.Klein, R. H., 221.Klein, W., 104.Kleinfeller, H., 120.Klekotka, J. F., 214.Klemenc, A., 49, 64.Klemm, W., 63.Klinkhardt, H., 48.Klinkott, G., 71.Klockmann, R., 227.Kloss, H., 125.Knappe, S., 64.Knauer, F., 12.Knopf, E., 149.Kobayashi, K., 209.Kober, S., 272.Kobliansky, G.G., 93.Koch, F. C., 223.Koch, F. K. V., 58, 340.Koch, J. E., 71.Koch, L., 285.Koch, P., 215.Koch, S., 294.Kockar, M., 216.Koechlin, R., 296.Koeck, W., 321.Konig, A., 68.Koenigs, E., 185.Iioppen, R., 74.Koerner, O., 64.Kofler, L., 222.Kogan, A. I., 224.Kohlrausch, F., 336, 337, 312, 347,Kohlrausch, K. W. F., 87,350, 355.Kolenko, B. Z., 297.Kolhorster, W., 322.Kolmer, E., 210.Kolthoff, I. M., 211, 213, 217, 21S,Kondo, H., 193, 194.Kondo, T., 193.Konopicky, K., 55.Konopnicki, A., 191.Koop, R., 78.Koopal, S. A., 115.Kopp, D., 45, 46.Kopsch, U., 49.Korenman, I. M., 210.Korolev, A. J., 222.Korpiun, J., 66.Kortum, G., 226.Kostelitz, O., 62.Kostychev, S., 243.Koia, J., 216.Kovalsky, A., 45, 40.Kovarik, .A. I?., 316.Kowalski, M., 299.Kozlowski, W., 70.Kracek, F.C., 56, 79, SO.Kracovski, J., 153.Kramers, H. A., 332.KranjheviE, M., 216.Krase, H. J., 80.Krasnovski, 0. V., 216.Kratzert, J., 216.Kraus, C. A., 65, 327, 336.Kraus, E. H., 301.Krauskopf, F. C., 220.Krauss, F., 60, 74.Kraut, F., 70.Kfepelka, J. H., 53.Krestinski, V. N., 98.Krestovnikov, A., 152.Krestovosdvigenskaja, T. .hi., 222.Krishnaswami, K. R., 53.IZrober, W., 100.Kruger, D., 223.Krug, H., 72.Krumholz, P., 210, 211'.Krupkowski, A., 77.Ksanda, C. J., 56.Kuherenko, V., 102.Kuchler, K., 221.Kuchlin, A. T., 97, 214.Kuhlenkampff, H., 323.Kuhn, R., 89, 90, 146, 160.Kuhn, W., 113, 149.Kulikov, J.V., 222.Kupalov, P. S., 258.Kura;, M., 211.Kurnakov, N. S., 76, 79.Kurtenacker, A., 69.TZuttner, T., 221.227, 228.Laar, J. J. van, 326.Laby, T. H., 204, 205INDEX OF AUTHORS' NAMES. 367Lagrave, n., 116.Lamb, (Miss) F. R., 228.LaMer, V. K., 333.Lammert, 0. M., 336.Lander, G. D., 222.Landesen, G., 73.Lang, H., 126.Lang, R., 217, 221.Lange, E., 160.Lange, W., 67.Langer, R. M., 19.Lannung, A., 55.Lapworth, A., 137, 146, 147, 148.Laqueur, E., 272.Larsen, E. S., 299, 300.Larsson, E., 224. .Lasch, H., 295.Lasky, 5. G., 293.Laszlo, D., 221.Lather, W. M., 130.Laudermilk, J. D., 296.Lauer, W. M., 213.Laun, I?., 337, 338.Laurence, G. C., 313.Lausen, C., 293.Lautsch, W., 125.Lavin, G. I., 49, 50.Lawrence, C.D., 86.Lawson, R. W., 310, 312.Lazarkevitsch, N. A., 213.Lazarus, L. H., 79.Lebeau, P., 64, 72.Lebedev, S. V., 91, 93.Le Boucher, L., 75.Lecat, M., 206.Leclerc, E., 227.Lederer, E., 175, 183.Leeper, G. W., 216.Leers, L., 115.LeFBvre, R. J. W., 133, 139,Leffmann, H., 222.Lehmann, G., 64, 76.Lehnatz, M., 262.Lehrer, E., 79.Leitmeier, H., 211, 212, 213.Lemke, A., 62.Lenher. S., 44, 59.40, 141.Lenher; V., 58.Lennard-Jones, J. E., 16, 17.Leonard, J. N., 57.Leone, P., 177.Leopold, H., 296.Leroux, H., 159.Lespieau, R., 86.Lesslie, (Miss) M. S., 115, 163.Levene, P. A., 108, 151, 265, 267.Levin, B., 201.LBvy, (Mlle.) J., 115, 116, 120.Levy, M., 106.Lewimohn, M., 79.Lewis, G. N., 324, 326.Lewis, J.F., 83.Lichtenstein, L., 221.Lieberson, A., 217.Liesche, O., 214.Ligor Bey, 210.Lilly, C. H., 235.Lind, S. C., 42, 92.Linda, S., 227.Lindemann, H., 63, 151.Lindenfeld, K., 223.Linder, J., 223.Lindner, J., 70,Lindquist, F. E., 48.Lindsey, A. J., 215.Lineweaver, H., 243.Ling, 250.Linggood, F. V., 251.Link, K. P., 239.Linstead, R. P., 101.Linstrom, C. F., 57, 66.Lipmann, F., 258, 260.Livingston, R., 42.Lock, G., 141, 225.Locquin, R., 115.Lob, A., 102.Loffler, J., 57, 79.Lowenbein, A., 126.Lowenberg, K., 169.Lowenstein, E., 61.Lohmann, K., 261, 265.Lomakin, B. A., 226.London, E. S., 265.London, F., 14, 16, 19.Longinescu, G. G., 221.Lorant, I. S., 220.Lora y Tamayo, M., 214, 220.Lorentz, L., 16.Lorenz, R., 327.Lorenzo, J., 127.Loring, F.K., 52.Lovecy, A., 171.Lowry, C. D., jun., 82.Lowry, H. H., 52.Lowry, T. M., 83, 147, 160, 162, 164.Lucas, H., 226.Lucas, H. J., 53, 146.Luce, E., 116.Lubbert, W., 88.Lugrin, J. P., 60.Lukas, J., 216, 219, 226.Luke;, R., 134.Lunde, G., 77.LundegBrdh, H., 226.Lundell, G. E. F., 218.Lundsgaard, E., 259, 260.Lutz, R. E., 178.Lux, H., 72.Lycan, W. H., 95.Lyons, C. G., 35.Maass, O., 69, 86.McAlister, W. H., 78.McAlpine, L. K., 266.McAlpine, R. K., 308368 INDEX OF AUTHORS' NAMES.McBain, J. W., 38, 39, 79.McCance, R. A., 225.McCay, L. W., 67.McCombie, H., 141, 142.McCrae, J., 297.McCubbin, R. J., 91.Macfarlane, M. G., 264.McGechen, J. F., 133.Machatschki, F., 286, 289, 291, 300.Machemer, H., 112.Machu, W., 55.MacInnes, D.A., 345, 347, 356.Mclntyre, L. H., 59.McKenzie, A., 115, 120.McKenzie, B. F., 254.McKinnis, R. B., 251.McLennan, J. C., 54.Macmillan, W. G., 141.Madelung, W., 115.Maeda, T., 218.Maimeri, C., 123.Majdel, J., 215, 217.Makarov, S. Z., 79.Makris, K. G., 212.Malachta, S., 223.Malaprade, L., 62.Malhotra, K. L., 80.Malinovski, V., 56.Malitzky, V. P., 212.Malkin, T., 175, 253.Malkowski, S., 299.Mallison, H., 175.Malone, G. B., 222.Malowan, S. L., 212.Malsch, J., 355.Maltby, M. E., 336.Manchot, W., 64, 68, 75, 76.Manicke, P., 214.Manini, A., 223.M a n , F. G., 77, 157, 150, 165.Manske, R. H. F., 146, 147, 148,Mantel, S., 78.Marecek, V., 103.Marggraff, I., 212.Marino, L., 169.Mark, H., 33.Marloth, B.W., 224.Marotta, D., 302.Marque, J., 225.Marrian, G. F., 224, 272.Marrian, P. M., 224.Marshall, P., 297.Martin, A. R., 340, 345.Martin, F., 215.Martin, J. T., 252.Martini, A., 211.Martini, H., 62.Marum, E., 338, 343.Marvel, C. S., 151, 222.Maskell, E. J., 248.Mason, H. L., 254.Mason, T. G., 248.183.Masriera., M., 223.Masucci, P., 266.Matejka, K., 69.Mathes, W., 128.Mathews, A. L., 301.Mathias, O., 322.Mathur, F. C., 133.Matinschkina, A. A., '31.Matossi, F., 28.Matsuhashi, T., 73.Matsunaga, Y., 78, 80.Matthes, H., 303.Matveev, N., 218.Maulik, S. N., 76.Maurer, K., 107.Mavin, C. L., 74.Mawson, D., 301.Maxim, M., 266.May, R., 221.Mayes, H.A., 138.Mayr, C., 227.Mazzocco, P., 302.Mebane, W. M., 217.Mecke, R., 21, 30, 52.Mehta, T. N., 87.Meijer, J. W., 225.Meinert, R. N., 92.Meisel, K., 62, 63.Meisenheimer, J., 165.Meissner, H., 210.Meissner, W., 54.Meitner, (Frl.) L., 314.Meldrum, N. U., 256.Mellanby, E., 167.Meloche, V. W., 58.Menke, H., 32.Menon, K. N., 199.Menzel, H., 60.Menzel, W., 71.Merrill, G. P., 304.Messinger, J., 221.Metz, E., 260.Meulen, H. ter, 224.Meulen, J. H. van der, 214.Meyer, J., 69, 70, 223.Meyer, K. H., 33, 113.Meyer, R. J., 53.Meyerhof, O., 242, 258, 259, 261Meyring, K., 216.Michael, A., 85, 86.Micheel, F., 105, 106.Micheel, H., 106.Mickey, I. J., 300.Midgley, T., jun., 88.Mieg, W., 167.Miehr, W., 216.Migita, M., 116.Mignonac, G., 91, 92.Miholib, S.S., 218.Mikeska, L. A., 151, 265.Miki, K., 109.Milbery, J. E., 103.Milgevskaja, W. L., 219INDEX OFMiller, E. J., 104.Miller, H. K., 225.Miller, L. F., 219.Millikan, R. A,, 322, 323.Millott, J. O’N., 78.Mills, A. KEY 116.Mills, J. E., 61.Mills, W. H., 131, 162, 163.Milner, S. R., 326, 327.Mirsky, A. E., 268.Mitchell, J. H., 302.Mithoff, R. C., 128.Mittelstaedt, O., 354.Mizgier, S., 301.Moberg, E. G., 303.Mottig, H., 68.Moffit, W. G., 134.Moldenhauer, W., 58.Moles, E., 39, 52, 53, 306.Mond, A. W., 76.Monnier, R., 60.Montagne, P. J., 115.Montgomery, E. M., 109.Montignie, E., 212.Moore, H. B., 303.Moore, R. B., 66.Moore, T., 276.Moratschevski, J.V., 292.Morey, G. W., 80.Morgan, G. T., 181.Morgan, J. L. R., 336.Morgan, W. T. J., 263.Mori, T., 265.Morley, A. M., 70.Morns-Jones, W., 54.Morton, R. A., 276, 277.Moser, G. H., 174.Moser, L,, 214, 217, 218, 219.Mosses, A. N., 146, 148, 152, 166.Mothes, K., 248, 249, 250.Mott, N. F., 18, 321.Mousseron, M., 217.Miihlhoff, W., 310.Miihlschlegel, H., 102.Miiller, Alex., 33.Miiller, Alexander, 107.Muller, Anton, 80.Miiller, Emil, 67.Miiller, Erich, 227.Muller, Eugen, 56, 125.Muller, Hans, 332.Muller, Heinz, 79.Miiller, K., 225.Mueller, W. H., 224.Miiller, W. J., 55.Mulliken, R. S., 305.Munch, J. C., 201, 221.Muralt, A. L. von, 257.Muromtzev, B., 56.Murphy, E. J., 203.Murray, C. W., 215.Murrey-Rust, D.M., 336, 337, 338,339, 343, 344, 345, 350, 353.SUTHOBS’ NAMES.Muskat, I. E., 87.Myles, J. R., 115.Myssovski, L., 322.Mytyzek, R., 60, 63.Nachmansohn, D., 260, 261.Nachtwey, P., 180.Nagai, S., 60.Nagai, W., 172, 201.Nagel, W., 84.Naito, R., 60.Nakamura, M., 298.Nakamura, T., 198.Nakanishi, S., 191.Nambo, T., 198.Nametkin, S., 160.Nanji, 250.Narayanan, B. T., 281.Narita, Z., 194.Nasini, R., 302.Natta, F. J. van, 94.NaudB, S. M., 52, 306, 310.Naujoks, E., 88.Nel, L. T., 297.Nelson, E. K., 202.Nemilov, V. A., 77.Neuman, E. W., 220.Neumayer, K., 217.Neville, A., 149.New, R. C. A., 63, 129.Newby, H. L., 249.Newhouse, W. H., 293.Newland, D. H., 301.Newlin, M. R., 102.Newton, E.B., 266.Newton, R. F., 50, 51.Nichols, M. S., 213.Nickerson, J. L., 312.Micloux, M., 223.Nicolet, B. H., 255.Nicolle, P., 115.Niederl, J. B., 208.Nierenstein, M., 175.Niessner, M., 212.Nieuwenburg, C. J. van, 214.Nieuwland, J. A.,,99.Niggli, P., 289.Nightingale, G. T., 244.Nimmo, R. R., 314.Nishida, K., 109.N@higori, S., 78.Nishikawa, H., 183.Nishio, H., 79.Nitzberg, 102.Nixon, I. G., 131.Nixon, J., 139.Nodzu, R., 110.Nogareda, C., 60.Noll, W., 300.Nonhebel, G., 348.Norman, A. G., 252, 253.Norris, F. W., 251, 252.36370 INDEX OF AUTHORS’ NAMES.Norrish, R. G. W., 24.Northrop, J. H., 267.Northrup, H. E., 87.Notevarp, O., 214.Noyes, A. A., 345.Noyes, W. A., 151.Oakdale, U. O., 207.Oakley, H. B., 338.Oberrniller, J., 137.Oberwegner, M., 115.O’Connor, E. A., 37.O’Dwyer, M.H., 253.Ohman, E., 79.Olander, A., 20.Oesterle, 0. A., 172.Ogburn, S . C. jilii., 211).Ohle, H., 102, 103, 105.Ohta, T., 190.Oka, S., 299.Okabe, E., 227.Okey, R., 224.Oldham, J. W. H., 104, 109.Olsson, F., 71, 73.Onorato, E., 62.Onsager, L., 331, 333, 337, 343.Oort, H. D. van, 250.Opichtina, M. A., 79.Oppenheimer, J. R., 325.Opwyrda, H. F., 224.Orhkhoff, A., 116, 120.Orlik, W., 214.Orr, J. B., 240.Orth, P., 127.Orthner, L., 115.Ortner, G., 62.Osaka, Y., 79.Osawa, A., 79.Ostern, P., 261.Ott, E., 202.Oxford, A. E., 137.Paal, C., 84.Pace, E., 62, 86.Pacsu, E., 102, 107.Padelt, E., 43.Pagel, H. A., 217, 220.Pai6, M., 80.Palache, C., 296, 297, 304.Palfray, L., 223.Palmer, W.G., 64.Paloheimo, L., 225.Paneth, F., 125, 321.Panopoulos, G., 213.Pantschenko, G. A,, 212.Papish, J., 226, 304.Parker, E. W., 336.Parker, H. C., 336, 343.Parker, K., 355.Parkes, G. D., 224.Parravano, N., 62.Parsons, A. L., 298.Parsons, J. B., 62.Partington, J. R., 66, 348, 356.Partridge, H. M., 209, 211.Passerini, L., 62, 80.astorello, S., 80.atat, F., 49.Patey, A., 262.Paton, 250.Patrick, W. L., 40.Paul, W., 121.Pavelka, F., 210, 212.Pavolini, T., 212.Paweck, H., 226.Peaker, C. R., 38.Pearce, J. N., 39, 348.Pearsall, W. H., 249.Pearson, T. G., 57.Pease, R. N., 92.Peel, J. B., 74.Penfold, A. R., 166.Perkin, A. G., 239.Perkin, W. H., 182, 183, 180, 192,Perles, J., 324.Perraud, S., 101.Perrey, (Frl.) H., 107, 198.Perrin, J., 38.Perrott, C.H., 121.Perry, E. L., 296.Perry, J. W., 302.Peter, A., 75.Peters, A. T., 133.Peters, K., 55.Peters, R. A., 40, 267, 281.Petzetakis, A., 213.Pfau, R., 70.Pfeifer, T., 197.PfeifTer, P., 59.Pfrengle, O., 75.Pfundt, A., 228.Phelps, H. J., 40, 41.Philbrick, F. A., 72.Philip, J. C., 338.Philipp, K., 219, 314.Philippi, E., 271.Phillips, A. W., 308.Phillips, F. C., 298.Phillips, H., 149.Piccardi, G., 60, 226.Pictet, A., 109, 192, 197.Pien, J., 215.Pierri, J., 224.Piggot, C. S., 315.Pikazin, Y. S., 223.Pikl, J., 190.Piiia de Rubies, S., 226.Pinck, L. A,, 132.Pines, C. C., 222.Pinkus, A., 215.Piper, S. H., 253.Pirlot, J.M., 217.Pauling, L., 333.196, 197, 199, 200INDEX OF AUTHORS’ NAMES. 37 1Pirsch, J., 161.Pirtea, T. I., 221.PisafiEek, A., 63.Pitter, A. V., 79.Plant, S. G. P., 161, 182, 188, 189.Platzmann, C. R., 69.Pocher, W., 77.Poethke, W., 214.PogBny, L., 123.Pogodin, S. A., 79.Pohle, K., 261, 262.Poir6, I. V., 293.Pokrowski, G. I., 311.Polanyi, M., 20, 26, 37.Polenske, R., 160.Polissar, M. J., 21.Yollard, A., 134.Pollet, H., 220.Pondal, I. P., 300.Ponndorf, W., 224.Poole, J. H. J., 323.Pope, (Sir) W. J., 14‘3, 157, 162.Popesco, C., 224.Popper, E., 127.Porter, C. R., 102, 207.Porter, C. W., 130.Pose, H., 320.Potter, M. C., 302.Poulenc, P., 76.Pratesi, P., 228.Pratt, 0. B., 213.Preece, I.A., 252.Pressprich, G., 67.Preston, G. H., 124.Prianischnikov, D., 245, 246.Prideaux, E. B. R., 78.Pries, P., 88, 89.Pring, (Miss) M. E., 287.Pringsheim, H., 110, 111, 263.Pringsheim, P., 225.Prochaska, F. J., 302.Pschorr, R., 197.Pugh, W., 65.Pummerer, R., 168.Purkayastha, R. M., 47.Pusch, J., 180.Pushin, N. A., 74.Puxeddu, E., 302.Pyman, F. L., 142.Popov, s., 220.Qudrat-i-Khuda, M., 153.Querberitz, F., 88.Rabe, P., 201.Rabinovitsch, E., 20, 24.Radischtschev, V. P., 81.Rahlfs, E., 80.Raiford, L. C., 148.Raistrick, H., 230, 231, 232, 233, 234,235, 236, 237.Rambaud, R., 98.Ramsey, J. B., 219.Rancaiio, A., 213, 226.Randall, M., 336.Randolph, E. E., 301.Rankin, J., 197.Rankoff, G., 85.Rao, K.A. N., 155, 160.Rappaport, F., 268.Rau, H., 113.Raurich, F. E., 212.Ravenswaay, H. J., 224.Ray, F. E., 151.Ray, J. C., 285.Ray, P. C., 69, 75.Rayleigh, (Lord), 309.Raymond, A. L., 108.Raynolds, J. A., 70.Razubaiev, G., 56.Rebmann, L., 168.Redlich, O., 79.Reed, R. D., 212.Reedy, J. H., 70, 219.Rees, 0. W., 302.Regener, E., 322.Reich-Rohrwig, W., 218.Reichstein, T., 178, 179.Reid, E. E., 222.Reif, V?., 219.Reihlen, H., 70, 75, 165.Reilly, J., 110, 111, 135.Reindel, W., 168.Reinitzer, B., 220.Reisener, H., 356.Reistal, M., 73.Reith, J. F., 213, 221, 223, 302.Remy, H., 327, 352, 356.Renfrew, A.’G., 266, 267.Restaino, S., 63.Reuss, W., 67.Reynolds, J. E., 76.Rice, F. O., 99, 100.Rice, 0. K., 27.Richards, T.W., 308.Richardson, J. R., 226.Richarz, S., 296.Richert, P. H., 224.Rickles, D. N., 70.Rideal, E. K., 30, 35.Riebel, P., 117.Riechemeier, O., 49.Rieckhoff, H., 355.Rienacker, G., 63, 73.Ries, K., 74.Riesenfeld, E. H., 46.Righellato, E. C., 356.Rimattei, F., 226.Rimington, C., 224.Rinck, E., 80.Rintoul, W., 230, 234, 237.Ritchie, M., 53.Ritter, H., 182.Rius y Mir6, A., 227372 INDEX OF AUTHORS’ NAMES.Robbins, W. R., 244.Robert, J., 225.Roberts, E. G., 266.ltobertson, A., 107, 108, 176, 177,Robertson, H. C., 355.Robertson, I. M., 209.Robertson, P. W., 207, 223.Robinson, A., 219.Robinson, G. M., 182.Robinson, (Mrs.) G. M., 185.Robinson, H., 312.Robinson, M. E., 245, 247.Robinson, P.H., 139, 141.Robinson, P. L., 57, 74.Robinson, R., 134, 137, 171, 172, 173,175, 179, 182, 183, 184, 185, 193,199, 200, 237.Robinson, R. A., 70.Robison, R., 263.Roche, J., 268, 270.Rode, E. J., 77.Rodebush, W. H., 56.Rodionov, W. M., 222.Rodt, V., 74.Roer, O., 220.Rbhl, K., 88.RBmersperger, H., 303.Roger, R., 115, 120.Rogers, A. F., 294.Roginsky, S., 27.Rollefson, G. K., 48.Rollet, A. P., 58, 80.Roman, W., 224.Romieuu, J., 301.Rosbaud, P., 77.Roselius, W., 139.Roseman, R., 213.Rosen, B., 50.Rosenbaum, B., 126.Rosenblatt, F., 77.Rosenblum, S., 313.Rosenheim, A., 67, 71.Rosenkevitsch, L., 27.Rosenthaler, L., 211, 222.Ross, C. S., 295, 299.Ross, J., 85, 86.Ross-Kane, N. L., 340, 344, 350.Rosser, R.J., 161, 188,Rossi, L., 223.Rothen, A., 267.Rothstein, E., 152.Rouanet, 221.Rove, R. N., 293.Rublov, S. G., 59.Rudenko, N. P., 213.Riichardt, E., 52.Rugheimer, L., 192.Ruff, O., 64, 71, 72, 77, 214, 219.Ruhemann, M., 55.Ruhland, W., 245, 246.Runde, M., 178.Rupp, E., 38.178.Russell, A. S., 317.Rutgors, J. J., 223.Rutherford, (Lord), 311, 312, 313,314, 315, 317, 310.Rutterford, G. V., 225.Ruzicka, L., 152, 171.Ruziczka, W., 223.Ryan, J. D., 91.Rydbom, M., 224.Ryskaltschuk, A., 243.Saakov, 5. G., 213.Sabetay, S., 223.Sachtleben, R., 53.Sack, H., 334, 354.Sadrawetz, B., 221.Saenger, H. H., 77.Sagaidatschni, A. Y., 78.Sagortschev, B., 215.Sagulin, A., 45, 46.Saitb, K., 184.Saito, S., 227.Sakaguchi, K., 233.Salaman, E., 312.Salkind, J.S., 84.Salter, W. T., 274.Samdahl, B., 213.Samorueev, G. M., 79.Sampson, E. S., 295.Samuel, R., 16.Sand, H. J. S., 227.Sandell, E. B., 217.Sandonnini, C., 74.Sandved, K., 333.Sanfourche, A., 67.Sanna, G., 302.Sarkar, P. B., 79, 217.Saschek, W. J., 208.Sato, S., 176, 177.Sattler, H., 249.Sattler, L., 225.Sauciuc, L. I., 68.Saunders, B. C., 162.Saunders, S. L. M., 141.Sawyer, E. W., 352.Sborgi, U., 79.Scagliarini, G., 228.Scarborough, H. A., 136, 139, 140,141, 142.Schaad, R. E., 82.Schachkeldian, *4., 21 1.Schachtachabel, P., 291).Schaoffer, C., 28.Schaeffer, J. M., 241.Schiirer, O., 332.Schairer, J. F., 80, 285.Schalek, (Frl.) E., 257.Schaller, W. T., 297.Jchapovalenko, A., 212.Schamovsky, A.M., 50.Jchatunovskaja, H., 40.Schauder, E., 180INDEX OF AUTHORS' NAMES. 373Scheibe, G., 22.Scheibler, H., 129.Scheil, E., 78.Schenck zu Schweinsberg, E., 117.Schenk, P. W.. 65.Schem.erhorn,' L. G., 244.Schewket, O., 214.Schiedewitz, H., 84.Schiemann, G., 139.Schikorr, G., 74.Schilov, N., 40.Schingnitz, R., 327, 348.Schischkin, N., 62.Schlapfer, P., 92.Schlesinger, H. I., 70.Schlubach, H. H., 103, 106,Schick, H., 333, 352.Schmid, E., 38.Schmid H., 76.Schmidt, G., 262.Schmidt, H., 126.Schmidt, H. W., 66.Schmidt, 0. T., 106.Schmidt, W., 77.Schmitz, A., 270.Schneider, F., 210.Schneiderhohn, H., 294.Schoeller, W. R., 219.Schon, P., 192.Schonberg, A., 121.Schtipf, C., 197, 198.Schoepfle, C.S., 91.Scholder, R., 57, GG.Scholz, H., 104.Schonberg, A., 120.Schoorl, N., 226.Schorstein, H., 228.Schotsky, K. F., 258.Schou, S. A., 30.Schreckenthal, (Frl.) G., 295.Schreiber, E., 279.Schreider, F., 208.Schreyer, R., 232.Schriever, W., 60.Schroder, K., 220.Schrlider, W., 78.Schradinger, E., 25.Schroer, E., 210.Schroeter, G.. 132.Schrbter, G. A., 103, 105.Schryver, S. B., 251.Schubert, F., 251.Schudel, G., 112.Schulek, E., 214.Schulte, M. J., 224.Schultze, G., 56, 125.Schule, E. H., 78.Schulz, H., GO.Schulze, A., 60, 67.Schumacher, H. J., 20, 43.Schumb, W. C., 64, 69.Schurink, H. H. J., 182.111.110,Schuster, F., 220.Schuster, L., 126.Schwartz, A,, 160.Schwartz, F., 296.Schwartz, G.N., 296.Schwarz, R., 65, 79.Schwarzenbach, G., 172, 173.Schweitzer, O., 110, 111.Schwezowa, O., 243.Scorah, L. V. D., 180.Scott, A. F., 53, 79.Scott, E. W., 178, 222.Scott, G. N., 336.Scott, J., 182, 183.Scott, W. D., 86.Seaman, W. A., 301.Seefried, H., 127.Segeberg, H., 88.Sehnoutka, J., 60.Sekito, S., 80.Semenov, N., 35, 45, 46, 47.Senftleben, H., 49.Sensi, G., 211.Sergeenko, P. S., 218.Serke, K., 223.Seshadri, T. R., 118.Seto, K., 298, 299.Sfiras, M., 115.Shachkeldian, A. B., 215.Shannon, E. V., 294, 300.Sharp, G. I., 141.Shedlovsky, T., 336.Sherrill, M. L., 84.Sherrill, M. S., 345.Shinoda, J., 176, 177.Shiraishi, S., 226.Shoesmith, J. B., 133.Shoppee, C. W., 152, 161, 1%.Short, a!€.N., 293, 294.Shriner, R. L., 150, 222.Shukov, I. I., 227.Siao, M., 71.Sibbern-Sibbers, (Fr.), 11 7.Sica, C., 302.Sidgwick, N. V., 63, 129, 352.Sieber, H., 96.Siegmann, F., 218.Sieverts, A., 56, 68, 77, 79.Signer, R., 110, 224.Silberstein, F., 268.Gimek, A., 70.Simon, A., 66.Simon, F., 38, 55.Simonis, H., 126.Simons, J. H., 69.Simonsen, J. L., 166.Simpson, H. G., 348.Singewald, J. T., 294.Sinka, A., 219.Sircar, S. S. G., 153.Sivadjian, J., 222.Skalla, N., 63.Skow, N. A., 65374 INDEX OF AUTHORS' NAMES.Slater, C. S., 225.Slawson, C. B., 301.Slonim, C., 60.Smiles, S., 122.Smith, A. M., 209.Smith, C., 132.Smith, D. M., 205.Smith, E. R., 356.Smith, G. F., 214.Smith, J. A. B., 103.Smith, J.C., 137.Smith, J. F., 184.Smith, S., 201.Smithells, A., 47.Smits, A., 55, 66, 67.Smoker, E. H., 56.Smyth, C. P., 338.Smyth, H. D., 50.Snedden, W. W., 122.Snee, W. E., 226.Snow, C. P., 30.Sobyanin, N. P., 213.golaja, B., 216.Solignac, M., 295.Solomon, D., 80.Someya, K., 227.Somiya, T., 215, 217, 226.Sonnenkalb, F., 74.Sontag, (Mlle.) D., 223.Souteyrand-Franck, (Mme.), 65.Spacu, G., 215.Spiith, E., 175, 183, 190, 193, 202.Spausta, F., 79.Speakman, J. C., 217.Spence, H. S., 298.Spence, L. U., 82.Spence, R., 45.Spencer, E., 298.Spencer, J. F., 227.Spencer, L. J., 297, 301.Spicer, W. E., 228.Spiers, C. H., 154.Spitzin, V., 68, 72.Sponer, H., 22, 48.Sprague, H. B., 224.Sreenivasaya, M., 230.Stadnikov, G., 304.Stahel, E., 315.Stanley, W.M., 240.Starek, W., 110.Starrs, B. A., 79.Stary, 2 ., 224.Statham, F. S., 166.Staudinger, H., 93, 110, 111, 113.Xtedman, E., 270.Stedman, (Mrs.) E., 270.Steele, B. D., 61, 347.Steenhauer, A. J., 222.Stehlik, B., 70.Stein, C. P., 31.Stein, G., 89.Stein, W., 64, 227.Steinbrunn, G., 113,Steiner, M., 240.Steiner, W., 66.Steinfeld, H., 74.Steinke, E., 322.Steinwehr, H. von, 67.Stent, H. H., 232, 233.Xtephan, E., 77, 210.Stephenson, (Miss) M., 229.i%Grba-Bohm, J., 63.Stern, O., 12.Stevens, T. S., 122.Stiebel, F., 38.Stieger, G., 43.Stiller, E. T., 122.Stiller, M., 217.Stobbe, H., 101.Stock, A., 62.Stockdale, D., 80.Stoddart, J. H., 303.Stoermer, R., 117.Stokoe, W.N., 230.Stoll, M., 152.Stoops, W. N., 338.Storch, H. H., 79.Stoughton, B., 79.Stoyle, J. A. R., 230.Strain, J., 101.Strassen, H. zur, 80.Straub, W., 271.Strebinger, R., 217.Stricks, W., 226.Stromberg, R., 39.Strolihacker, L., 38.Stuart, J. M., 68.Stubbs, J. R., 224.Stuckey, J. L., 299.Stuebel, H., 258.Stueckelberg, E. C. G., 50.Sturm, K., 177.Style, D. W'. G., 44.Subbarow, Y., 261.Subero, G., 213.Subramaniam, TT., 232, 233, 238.Suchier, A., 212.Suciu, G., 215.Sudzuki, H., 196.Sugasawa, S., 171.Sugden, S., 69, 129.Suhrmann, R., 38.Sullivan, F. W., 127.Sullivan, J. J., 100.Sunde, C. J., 213.Sunier, A. A., 30!).Suri, H. D., 80.Suszko, J., 191.Suter, C. M., 141.Sutherland, H. S., 86.Sutherland, W., 326.Sutton, L.E., 63, 129.Svanberg, O., 225.Svedberg, T., 34, 271.Swartout, H. O., 214.Sweeney, 0. R., 222INDEX OF AUTHORS’ NAMES. 375Sweet, (Miss) J. M., 301.Swift, E. H., 214.Sybzi, E., 218.Szancer, H., 221, 223.Szebellkdy, L., 215, 216.Szegva.ri, A., 257.Tabart, A., 116.Taufel, K., 224.Takahashi, T., 232, 233.Takeda, S., 227.Tamchyna, J. V., 210.Tamm, O., 286.Tamura, K., 222.Tanaka, C., 108.Tanaka, Y., 298.Tananaev, N. A., 210, 212.Tanner, M. G., 58.Tasaki, M., 78.Tashiro, S., 223.Tatsui, G., 184.Tattersfield, F., 241.Tausz, J., 67.Taylor, G. B., 59.Taylor, H. S., 21, 45.Taylor, M., 352.Taylor, T. ?V. J., 72.Taylor, W. A., 355.Tchdoufaki, 90.Teece, E. G., 104.Teichmann, L., 73.Teitelbaum, M., 215, 216.Teletov, I.S., 216.Terrey, H., 76.Testori, R., 211.Teterin, V. K., 84.Tedert, W., 143.Thayer, L. A., 220.Thayer, S., 272.Thiel, A., 213.Thiessen, P. A., 64, 74.Thivolle, L., 268.Thorn, C., 230.Thomas, L., 338, 343.Thomas, W., 244.Thompson, E., 284.Thompson, H. H., 49.Thompson, H. W., 44, 45, 46.Thompson, J. J., 207, 221, 223.Thompson, T. G., 303.Thorns, H., 190.Thomson, G. P., 38.Thomson, T., 122.Thornley, S., 182, 183, 184.Thornton, W. M., jun., 213.Thorpe, J. F., 85, 86, 154.Thorvaldson, T., GO.Thuesen, A., 356.Thurn, W. E., 216.Ticharich, N., 107.Tiede, E., 66.Tiedemann, E., 84.rietz, E. B., 223.rietz, E. L., 44.Tietze, W., 214.Tiffeneau, At., 115, 116.Tilden, J.E., 292.Tilley, C. E., 297.Tilley, F. W., 241.Timmis, G. M., 201.Tischbierek, 223.Titeica, R., 70.Tbdt, F., 55.Tohody, L., 294.Toischer, K., 60.Tolksdorf, S., 54.Tollert, H., 218.TomiEek, O., 227.Tomii, R., 227.Tompsett, S. L., 268.Tornula, E. S., 217.Tom, W., 80.Topley, R., 47.Torrey, G. G., 59.Tougarinov, B., 226.Tovarnitzki, V. I., 218.Traetta-Mosca, F., 235.Trasitz, 0. R., 208.Traub, 247.Travers, A., 60, 62.Treadwell, W. D., 64, 227.Troxler, L. B., 224.True, R. H., 240.Truesdale, E. C., 213.Tschernaiev, I. I., 76.Tschirch, E., 223.Tschmutov, K., 40.Tubakaiev, V. A., 212.Tucan, F., 300.Turner, 338.Turner, E. E., 138, 139, 140, 141,142, 163.Turner, R. G., 221.Turner, T. A., 222.Tutundiib, P.S., 74, 226.Tuvim, L., 322.Ueno, S., 78.Ulbrich, E., 123.Ulich, H., 327, 336, 337, 338, 340,342, 349, 350, 352, 353.Ullrich, H., 245.Unmack, A., 337, 340, 356.Urazov, G. G., 79, 292.Urbain, P., 226.Urech, C., 47.Urey, H. C., 49.Urry, W. D., 321.Ussanovitsch, M. I., 79.Uzel, R., 212.Valby, E. P., 140.Valdea, L., 227376 INDEX OF AUTHORS’ NAMES.Valentin, I?., 109.Vance, J. E., 78.Vanderwilt, J. W., 285.Vargha, L. von, 120, 121.Vass, C. C. N., 143.Vassiliev, A,, 218.Vasterling, 213.Veibel, S., 132.Veler, C. D., 272.Venus-Danilova, E., 11 5.Vermaas, N., 97.Vernadsky, V., 302.Vernon, R. H., 150.Veselovski, A. A,, 292.Vickery, H. B., 248, 250.ViIlars, D. S., 19.Vitoria, A. P., 78.Vogel, A.I., 145.Vogel, H., 110.Vogel, H. V. von, 63.Vogel, I., 152, 340, 346.Vogel, R., 77, 80.Vogt, R. R., 99.Voigt, A., 74.Vollrath, R. E., 99.Volmer, M., 36.Voogd, J., 54.Voskressenska, N. K., 81.VotoEek, E., 102, 109, 223.Vournazos, A. C., 68.Wachstein, W., 268.Waddington, W. B., 157, 186.Wade, M., 250.Wadlund, A. P. R., 324.Wagenaar, M., 221.Wagner, H., 174, 226.Wagner, 0. H., 65.Wagner-Jauregg, T., 89.Wahl, W., 163.Wake, A. C., 124.Walden, P., 327, 336, 337, 338, 339,Walker, J. C., 239.Walker, O., 277.Walker, T. K., 232, 233, 235, 236,Wallace, J. H., jun., 210.Wallace, J. I., 31.Wallmbe, G., 303.Walters, E. G., 66.Walton, A., 148.Walton, E., 169.Wander, G., 172.Wansbrough-Jones, 0. H., 50.Warburg, O., 242.Ward, A.F. H., 36.Ward, F. A. B., 312, 313.Wmd, J. C., 221.Wardlaw, W., 66, 70, 77, 164.Warren, B., 82.Warren, F. L., 89.340, 341, 342, 349, 350.238.Warren, L. A., 122.Wartenberg, H. von, 56, 65, 71.Warwick, L. E., 78.Wasilewski, L., 78.Wasmuht, R., 72.Wassermann, A., 146.Wassmuth, E., 46.Waterman, R. E., 280, 251.Waters, W. A., 136, 140, 141.Watson, F. J., 214.Watson, S. W., 312.Wattenberg, H., 68.Watters, A. J., 108.Wayland, E. J., 300.Wazelle, H., 79.Weall, H. G., 297.Webb, H. W., 70, 219.Webb, J. I., 103, 263.Webb, T. J., 333.Weber, C. J., 224.Webster, J. E., 249.Webster, M. M., 80.Webster, T. A., 277.Weevers, T., 249, 250.Wehmer, C., 232, 233.Wehrli, H., 167, 168.Weibke, F., 80.Weidenfeld, L., 216.Weidenhagen, R., 11 2.Weil, K., 56.Weil, R., 295.Weiland, H.J., 336.Weill, P., 115, 120.Weinbaum, O., 77.Weinhardt, A., 73.Weinland, R., 70.Weiser, H. B., 67.Weiss, H., 91.Weissbach, I<*, 143, 190.Weitz, E., 61.Welke, K., 37.Wells, R. C., 297, 301.Wentzel, G., 26.Werner, A., 164, 312.Wernert, I. J., 142.Wernicke, E., 61.Wortenstein, L., 311, 312.Werth, H., 65.Wertheim, E., 222, 223.Wessely, F., 174, 177, 178.West, R., 273, 274.Westhaver, J. W., 49.Westwood, J. B., 227.Wettstein, A., 168.Wet201, K., 245, 246.Wever, F., 77, 80.Wheeler, R. V., 82.Whetham, W. C. D., 336.Whitaker, H., 47.White, V. B., 25G.Whitmore, W. P., 210.Washburn, E. W., 336, 347, 332,355INDEX OF AUTHORS’ NAMES. 377Whitnah, C. H., 103.Whitworth, J. B., 162.Wibaut, J. P., 138.Wiberg, E., 61, 62.Widmer, G., 110.Widmer, R., 167, 173.Wiegrebe, L., 63.Wieland, H., 91, 125, 126, 271.Wieland, W., 64.Wien, M., 334, 355.Wierl, R., 32.Wigner, E., 26.Wildish, J. E., 316.Wilhelm, J. O., 54.Wilke-Dtjrfurt, E., 70, 73, 303.Wilkins, F. J., 36.Wilkins, T. R., 317.Wilkinson, D. G., 171.Will, G., 263.Willard, H. H., 66, 207, 209, 214,Willems, H. W. V., 285.Willey, E. J. B., 48, 66.Williams, R. R., 280, 281.Willingshofer, K., 221.Wills, G. O., 115.Willstiitter, R., 112, 123, 167, 175.Wilson, F. J., 101.Wilson, I. S., 134.Winckler, H., 89.Winogradsky, 243.Winter, K., 217.Winter, L. B., 268.Winter, 0. B., 216.Winternitz, R., 224.Wiskont, K., 214.Withrow, J. R., 212.Witmer, E. E., 324.Wohler, L., 76.Woidich, K., 221.Wolf, A., 112.Wolfenden, J. H., 335, 347, 356.Wolff, A., 71.Wolfrom, M. L., 102.Wolter, A., 151.Wood, R. W., 25.Wood, W. L., 82.Woodford, A. D., 296.Woolcock, J. W., 336, 348.Wooster, C. B., 65, 127.Wooten, L. A., 227.215, 217, 221.Wormwell, F., 68.Worner, (Miss), R. K. 70.Wright, C. P., 338, 344, 350.Wright, E. P., 356.Wright, F. E., 103.Wiilfert, K., 223.Wuillot, A., 268.Wulf, 0. R., 30.Wurm, K., 52.Wurm, V., 69.Wymore, I. J., 78.Wynne-Jones, W. l?. K., 72.Wynn-Williams, C. E., 312, 313.Yabuta, T., 235.Yagoda, H., 211.Yakimach, A., 68, 73.Yamaguchi, S., 116.Yamamoto, K., 299.Yntema, L. F., 63.Young, J., 304.Young, J. H., 150.Young, (Miss) P., 200.Young, R. C., 64.Young, W., 234.Young, W. G., 83.Zahn, H., 334, 354, 365.Zahnd, H., 223.Zaki, A., 133.Zambonini, F., 63, 297.Zapata y Zapata, C., 61.Zappi, E. V., 223.Zechmeister, L., 168.Zeigert, H., 315.Zerban, F. W., 225.Ziegler, K., 125, 126, 128.Ziegner, E. von, 271.Zijp, C. van, 222.Zimmermann, W., 222.Zintl, E., 73, 227.Zinzadze, R., 221.Zocher, H., 38.Zorner, A., 74.Zombory, L. von, 213, 217.Zunz, E., 223.Zvegintzov, M., 69.Zwicky, F., 333. IZymnov, P., 212

ISSN:0365-6217    

DOI:10.1039/AR9302700357

出版商:RSC    

年代:1930

数据来源: RSC