摘要:

ANNUAL REPORTSON THEPIXOGRESS O F CHEMISTRYANNUAL REPORTSON THEPROGRESS OF CHEMISTRYF O R 1 9 2 0ISSUED BY THE CHEMICAL SOCIETY.Btammittte of @ubliraiinn :A. J. ALLMAND, M.C., D.Sc.A. W. CKOSBLEY, C.M.G., C.5.E.,Sir JAMES J. DOBBIE, M.A., D.Sc.,M. 0. FORBTER, D.Sc., Ph.D., F.R.S.T. A. HENRY, D.Sc.J. T. HEWITT, M.A., D.Sc., Ph.D.,D.Sc., F.R.S.F. R. S.F. R.S.C. A. KEANE, D.Sc., Ph.D.H. It. LE SUEUK, D.dc.‘1’. M. LOWRY, C. R.E., D.Sc , F.R.S.J. I. 0. MAYBON, M.B.E., D.Sc.G. T. MORQAN, O.B.E., D.Sc.J. C. PHILIP, O.B.E., D.Sc., Ph.D.A. SCOTT, M.A., D.Sc., F.R.S.F. 11. S.E. C. C. BALY, C.B.E., F.R.S.G. I~ARGER, M.A., D.Sc., F.R.S.T. V. BARKER, M.A., B.Sc.J. KENNER, Ph. D., D.So.W. C. McC. LEWIS, M.A., D.Sc.@bitor :J. C.CAIN, D.Sc.56ub-6;bifor :A. J. GREENAWAY.Qatrtribut ars :C. AINSWORTH MITCHELL, 1It.A.R.H. PICKARD, D.Sc., Ph.D., F.R.S.R. ROBINSON, D.Sc., F.R.S.E. J. RUSSELL, O.B.E., D.Sc., F.R..S.F. SODDY, M.A., F.R.8.Pol. XVII.LONDON :GURNEY t J A C K S O N , 33 PATERN08TER ROW, E.C. 4.1921PRINTED I N GREAT BRITAIN BYTHE CORNWALL PRESS, LTD., PARIS GARDEN,STAMFORD STREET, LONDON, S.E. ICONTENTS.PAGEGENERAL AND PHYSICAL CHEMISTRY. By W. C. McC. LEWIS,M.A., D.Sc. . * . . . , . . . . . . 1INORGANIC CHEMISTRY. BY E. c. c. RAL;, c.B.E., F.R.S. . . 27ORGANIC CHEMISTRY :-Part ~.-ALIPHATIC DIVISION. By R. H. PICKARD, D.Sc., Ph.D., F.R.S. 52Part II.-HOMOCYCLIC DIVISION. By R. ROBINSON, D.Sc. . . . 69Part III.-HETEICOCYCLIC DIVISION.Ry J. KENNER, Ph.D., D.9c. . . 96ANALYTICAL CHEMISTRY. By C. AINSWORTH MITCHELL, M.A. . . 130PHYSIOLOGICAL CHEMISTRY. By G. BAHGER, M.A., D.Bc., F.R.S. . 152AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.BYE. J. RUSSELL, O.K.E., D.Sc., F.R.S. . . . . . 175CRYSTALLOQRAPHY AND METALLURGY. By T. V. BARKER, M.A.,R.Sc. . . . . . . . . . . . . 198RAIIIOACTIVITT. BY F. SODDY, M.A., F.R.S. . . . . . 21ABBKEVIATEU TITLE.A . , . . .Amer. J. Bot. . .Amer. J. Pharnz. .Amer. J. Sci. . .Analyst . . .Annalen . . .Ann. Chim. . .Ann. Chiin. anal. ,Ann. Inst. Pasteur .Ann. Physik . .Ann. Physique . .Ann. Report . .Annali Cham. AppE. .Apoth. Zeit. . .Arch. ital. Biol. .Arch. mkd. exp. . .Arch. Phnrm. . .Arkiv. Kem. Hin. Geol.Astrophys. J.. .Atti R. Accad. Liwei .Ber. . . . .Ber. Deut. hot. Ges. .Ber. Deut. physika?. Gts.Biochem. J. . .Biochem. Zeitsck. .Boll. chim. farm. .Bot. Gnz. . .Brit. Med. J. . ,Byit. Pat. . . .Bull. Aead. Sci. Petrograd.Bzcll. Assoc. Chim. Sucr.Bull. Jard. bot. Buitenzorg.Bull. Sci. Pharmacol. .Bull. SOC. chim. . .Bull. SOC. chim. Biol. .Bull. Soa. fracnq. Min. .Centr.Nin. . . .Chcm. and Met. Eng. . .Chem. News . . .Chem. Weekb2a.d . .REFERENCES.TABLE OF ABBREVIATIONS EMPLOYED IN THEThc year is not. inserted in references t o 1920.JOURNAL.Abstracts in Journal of the Chemical Society. ‘American Journal of Botany.American Journal of Pharmacy.American Journal of Science.The Analyst.Justus Liebig’s Annalen der Chemie.Annales de Chimie.Annales tle Chimie snalgtique appliquhe h l’hdustrieA l’bgriculture, It la Yhsrmacie e t B la Riologie.Annalea de 1’Institut Pasteur.Annalen der Physik.Annales de Physique.Annual Reports of the Chemical Society.Annali di Chimica Applicata.Apotheker-Zeitung.Archives italiennes de Biologie.Archives de medicine experimentale e t d’anatomiopath ologique.Archiv der Pharmazie.Arkiv for Kemi, Mineralogi och Geologi.Astrophysical Journal.Atti della Reale Accademia dei Lincei.Berichte der Deutschen Chemischen Gesellschaft.Berichte dcr Deutschen botanischen Gesellechaft.Rerichte der Deutschen physikalischen GesellschaftThe Biochemical Journal.Biochemische Zeituchrift.Bolletino chimico farmaceutico.Botanical Gazette.British Medical Journal.British Patent.Bulletin de 1’Academie Impdriale des Sciences dePet rograd.Bullet in de l’dssociation des Chimistes de SuorerieBulletin du Jardin botanique de Buitenzorg.Bulletin des Sciences Pharmacologiques.Bulletin de la Sociktt? chimique de France.Bulletin de la SociBtd de Chimie bioloai ue.Bulletin de la Sociktt? frangaise de MiEzalogie.Centralblatt fiir bl ineralogie, Geologie und Palaeoiito-Chemical and Metallurgical Engineering.Chemical News.Chemisch Weekblad.et de Distillerie.logieviii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.Chcm. Zeit.. . .Chem. Zentr. . . .Cmpt. rend. . .Compt. rend. Xoc. BWZ. .Deiitsch. waed. Woch. . .Puhlings Landw.Zeit. .Gazzetta . . . .Qesundheits-Ing. . .HeZv. Chivt. Acta . .Int. Mitt. Bodenk. . .Int. Zeitsch. phys. - chcm.Biol. . . . .Jahrb. Mzn. . . .D.R.-P. . . . .Jahrb. Min. Bcil. B d . .Jahrb. Rndioaktiv. EZek-tronik . . . .J. Agric. Bee. . . .J. Agrie. Xci. . . .J. Amer. Chem. SOC. . .J. Amcr. Pharm. Soc. .J. Assoc. 9f. Agric. Chena.J. Biol. Chem. . . .J. Chim.phys. . . .J. Gasbelczccht. . . .J, Gen. Physiol. . . .J. Ind. Eng. Chem. . .J. Ind. In&. Sci. . .J. Opt. SOC. Amer. . .J. Path. Bact. . . .J. Pharm. Chim. . .J. Pharm. Expt. Ther. .J. Pharm. Xoc. Japan. .J. Phys. Adium . .J. PhyszcaE Chem. . .J. Physiol. . . .J. Physiol. Path. 9th. ,J. pr. Chem. . . .J. Proc. Asiatic Soc. BcngalJ.S. African Assoc. Anal.Chem. , . . .J. SOC. Chem. Ind. . .J. SOC. Dyers and CoZ. .J. Tokyo Chem. SOC. . .J . Washington Acad. Xci. .Roll. Chem. Beihefte . .KolZoid Zeitsch. . .Medd. K. Vetenqkapsakad.Nobcl-Znsf. . . .Mededeelingen Geneesk. Lab.Weltevreden . . .Mm. CoZl. Sci. Kyat6 .Mein. Dept. Agric. ImiiaJOURNAL.Chemiker Zeitung.Chemisches Zentralblatt.Comptes rendus hebdomadaires des SQancee deComptes rendus hebdomadaires de SPances de laDeutsches Reichs-Patent.Deutsche medizinische Wochenschrift.Fuhlings Landwirtschaftliche Zeitung.Gazzetta chimioa itolians.Oesucdheits-Ingenieur.Helvetica Chimics Acta.Internationale Mitteilungen fur Hodenkunde.Internationale Zeitschrift fur phyoikdisch-chemischeNeues Jahrbuch fiir Mineralogie, Geologie undNeue.5 Jahrbuc ti fiir Rlineralogie, Geologie undJahrbuch der Rad ioak tivi ta t nnd Elek tronik.Journal of Agricultural Research.Journal of Agricultural Science.Journal of the American Chemical Society.Journal of the American Pharmaceutical Association.Journal of the Association of Official AgriculturalJournal of Biological Chemistry.Journal de Chimie physique.Journal fur Gasbeleuchtung und M7asserversorgung.Journal of General Physiology.Journal of Industrial and Eligineering Chemistry.Journal of the Indim Institute of Science.Journal of the Optical Society of America.Journal of Pathology and Bacteriology.Journal de Pharmacie et de Chimie.Journal of Pharmacology and Experimental .Thera-Journal of the Pharmaceutical Society of Japan.Journal de Physique et le Radium.Journal of Physical Chemistry.Journal of Physiology.Journal de Physiologie et de Pathologie gknkrale.Journal fur praktische Chemie.Journal and Proceedings of the Asiatic Society ofJournal of the South African Association of AnalyticalJournal of the Society of Chemical Industry.Journal of the Society of Dyers and Colourists.Journal of the Tokyo Chemical Society.Journal of the Washington Academy of Sciences.Kolloidchemische Beihefte.Kolloid Zeitschrift.Meddelanden fran Kongl-VetenskapsakademiensNobel-Institut.Veearteenij kundige Mededeelingen uit het Genees-kundig Laboratorium t e Weltevreden, Bataria.Memoirs of the College of Science, Ky6t6 Imperia 1Meinoirs of the Department of Agriculture in India.1'Acade'mie des Sciences.Socie't6 de Biologie.Biologie.Palaeontologie.Palaeontologie; Beilage Band.Chei ti ists.peutics.Hengal.Chemists.UniversitTABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.LXARBREVIATED TITLE.M c m . Munchester Phil. SOC.Min. Mag. . . IMitt. Nalzuforach. Ces.Halle . . . .iMonatsh,. . . . .iVachr. Ces. 1yiSs. CJotti?qeii.of vers. Ir’inska Vet. - ,5‘oc.Ocsterr. C1mn.-Zed. . .P . . . . .Pfliiger’s Arrliic . . .PhnntL. FVeekblatl . .Phurm. Zentr. -11. . .Pail. Maq. . .Zcitsch.. aszal. Chea~. . .Zciitsc1~. nngew. C’hmn. .Zeitsclb. anorg. Clzenb. . .Zeitsch. Elektroclzenz. . .zcitSCh. ri77.ys.1. , ~ i i ~ ~ . . .JounNAL.Memoirs and Proceedings of the Mrtnchester LiteraryMineralogical Magazine and Journal of theMitteilungen der Naturforschenden Gesellschaft x uillonatshefte fur Cheinie und verwandte Theile andererNachrichten von der Gesellschaft der Wissenschaftenofversigt af Finvka Vetenskaps-Societetens Fijrhand-Oestwrebichische Chemiker-Zeitung.l’roceedings of the Chemical Socie ty.Archiv Kir die gesamrnte Physiologie des MerischeaPharrnaceuLisch Weekblatl.Yharrnazeutische Zentralhalle.Phi1osoi)hical Magazine (The London, Edinburgh andDublin ).Philosophical Transactions of the Hoy~1 Society ofLondon.Physical Review.Physikalische ZeitschriftProceedings of the American Institute of E1ectric:alProceedings of the American Philosophical Society.Proceedings of the Colorado Scientific Society.Proceedings of the Iowa Acadeiiiy of Science.Iioninklijke Akademie van Wetenschappt+u te Amster-dam.Proceedings (English version).!’rocaodings of the National Academy of Hciences.Proceedings of the Royal Society.Proceedings of the Society for. Experimental 1:iologvi:cJcueil cles trsvanx chimiques ties P;1.ys-I3xs et (it: laSchweizerische Apotheker Zeitung.Scientific Proceedings of the Itoyal Dublin Society.Science Reports, T6hoku Imperial University.Sitzuiiwbericlite der L41iade~riie der ~Yissenschsften,Sitzunll-sberichte der Preussisclien Akacleiiiie derSkandinavisches rlrcliiv fiir Yliysiologie.Soil Science.Stazioni sperimentali agrarie i taiiane.Transactions of the Chemical Society.Transactions of the American Electrochemical Society.Transactions of the Royal Society of Canada.‘I‘raiisactiuiis ot’ the Society 01’ Glass Technoiogy.i’nited States E’atgnt.Anzeiger der Akiideniit: der Wissenschaf‘teu hl itthe-Inatisoh-Naturwissenschaftliche Klnsse, \Vim.Zeitschrift fur analytische Chemie.Zeitschrift fiir angewandte Chemie.Zeitschrift fur aiiorganische uncl allgemeine Cheiiiia.Zeitschrift fiir Elektrochemie.Zeitschrift fur Rrystallographic: und Minerdogie.and Philosophical Society.Mineralogical Yocirty.Halle.Wissenschaften.zu Gottingen.linvar, Helsingfors.und der Thiere.Engineers.niicl Medicitie.Celgiqua.$en.W”lsenschafteri zu Berlin.X TABLE OF ABBREVIATIONS EMPLOYED IN THE HEFERENCES.ARBREVIATED TITLE.Z&h.Nahr.-(3enwmn. ,Zeitseh. Phyaik . . .Ze+tsch. physikal. Chern. .Zeitacch. physikal. Chem.Unterr. . . .Zeilsch. p h y ~ w l . Chem. .Zsitsch. Ver. hut. Zucker-id. . . . .Zeilxh. wim. Photochcm. .JOURXAL.Zeitschrift fur Untersuohung der Nahrungs- undGenussnii ttel.Zeitschrift fur physik.Zeitschrift fur physikalische Chemie, StichiometrieZeitschrift fur den physikalischen und ChemischenHoppe-Seyler’s Zeitschrift fur physiologische Chemie.Zeitschrift des Vereins der deutschen Zucker-Zeitschrift fiir wissenschttftliche Photographie, Photo-und Verwandtschaftslehre.{Jnterricht .Industrie,physik und Photochemie

ISSN:0365-6217    

DOI:10.1039/AR92017FP001

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.MANY papers have been published on orthodox inorganic chemistryduring the last, year, and several of these awaken more than a pass-ing interest. There have appeared, however, four papers by Aston,Rutherf ord, Harkins, and Wendt and Landauer, which outshineall others in importance, for without question they bid fair to revo-lutionise the fundamental conceptions of chemistry. Whilst bysome the signs of the impending change have been recognised, themajority of chemists must now awaken to the fact that a newphilosophy is beicg born. The brilliant discoveries of Soddy andFajans of the existence of isotopes mark the first real step after thediscovery of the production of helium in the radioactive disintegra-tion of atoms. About the same time Thomson, Collie, Patterson,and Masson stated that helium and neon are produced in hydrogen-filled vacuum tubes under the influence of a powerful electric dis-charge.Very soon afterwards appeared the Harkins theory thatall elementary atoms are built up either of helium atoms or ofatoms of helium and hydrogen. Last year the next step wasgained when Rutherford succeeded in disrupting the atom ofnitrogen.It may now be said that the whole story is practically complete,and a wonderful story does it prove to be. Perhaps the moststartling of all the new knowledge gained is that on the oxygenstandard all atomic weights, with the exception of hydrogen, areexact whole numbers, and that the fractional values we haveaccepted as the resnlt of highly accurate work are merely fortui-tous statistical averages due to a mixture of two or more isotopes.Whilst this has been proved by experiment, it also is a necessarycorollary of the theories of atomic structure.In the annual Reportfor 1917 reference was made to Harkins’ theory that all elementaryatoms are built up of helium atoms or helium and hydrogen atom0This theory has now been published in its complete form, and itcarries conviction in its train. An essential feature is that thehydrogen isotope H, plays an integral part in atomic structure, thatit has a definite power of existence, and that very probably it i28 ANNUAL REPORTS ON THE PROGRESS. OF CHEMISTRY.identical with the nebular material called nebulium. First de-tected by Thomson, then more fully confirmed by Aston, H, hasnow been prepared from hydrogen.Then, again, Rutherford has shown that by the disruption of theatoms of oxygen and nitrogen an element of mass 3 is produced,which, however, is an iso€ope of helium.Rutherford considers thatthe atom of mass 3 which enters into the nuclear structure of atomsis this helium isotope and not H, as Harkins assumes.Whichever view may prove to be correct, there can now be littledoubt that all elementary atoms are built up from helium or fromhelium and atoms of mass 3, and, moreover, it is accepted by thenew school that helium itself is built up from four atoms of hydro-gen. The added importance of Collie’s work on the formation ofhelium and neon in hydrogen-filled vacuum tubes is manifest, forit has now become an obvious result from the new theories.Another most interesting aspect of this new knowledge is thatthe synthetic process whereby our elements are known to beproduced during the life history of the stars from the originalnebulium by way of hydrogen and helium can now be understood.It ic; diflicult to write of these discoveries and theories in a calmand measured fashion.They are so great in their achievement, sostupendous in their meaning, and so subversive in their effect thatsome enthusiasm may perhaps be allowed to him who records them.Strange it is that after all these years the old hypothesis of Proutshould rise triumphant, for, in a word, it is this that has occurred.In the Report for 1914, when the discovery of isotopes and Collie’swork had been announced, the writer ventured t o write the follow-ing words: “As did his forefathers of pre-Avogadro days, so alsodoes he (the chemist of today) now await that great generalisationwhich shall co-ordinate and link up all the threads to found a newphilosophy.Radioactivity, enhanced line spectra, the intra-stellarelements, zctive nitrogen and oxygen, atomic disintegration,atomic-weight variation, all ill be unified and embodied in thenew philosophy of the twentieth century. Then will a new chem-istry in its greater meaning emerge as a phcenix from the glowingparental fires of the many chemistries of to-day.”Little apology is needed for making this quotation, since theprophecy seems to be almost complete in its fulfilment.Atomic Theory.In the Reports for 1913 and 1914 reference was made to the workof Thomson, of Collie and Patterson, and of Masson on the pro-duction of helium and neon from hydrogen a t low pressures undeINORGANIC CHEMISTRY. 29the influence of the electric discharge.Negative results wererecorded by Strutt and by Merton, but Collie, using Merton's ownapparatus, obtained definite evidence of the formation of boththese gases. Some further experiments have been carried out dur-ing this year, and once more negative results have been obtained.1I n view of the fact that Collie himself more than once obtainednegative results when using different induction coils, the writersuggested that the explanation of the divergence of the resultsobtained by different observers is t o be found in the fact that aparticular type of discharge is necessary.Piutti and Cardoso,whilst admitting that our rudimentary knowledge does not permitus to discuss this explanation, point out that their resultsstrengthen the probability against it. They say that as in thesomewhat analogous case of active nitrogen, where considerabledivergence of opinion existed, if would be advisable that joint workbe carried out systematically in order definitely to settle thisimportant question.There is little doubt Chat the trend of recent ideas wi1.l createless antagonism t o the formation of helium and neon in vacuumtubes than was the case six years ago. The work of Rutherford onthe disintegration of nitrogen and oxygen atoms has underminedthe old confidence in the immutability of the atom.On the otherhand, all other experimental work has been in the direction of thedisruption of atomic nuclei, whilst Collie's work means a synthesisof atomic nuclei heavier than the pirent hydrogen.There can be no question that on0 of the most complete theoriesadvanced as regards the structure of atomic nuclei is that byHarkins.2 His earlier papers were reviewed in the Report for1917. *4ccording to this theory, the elements are of two kinds,namely, those of even atomic number, the atomic nuclei of whichare composed of helium nuclei alone, or helium nuclei together withcementing electrons, and those of odd atomic number, the nuclei ofwhich are composed of helium and hydrogen nuclei together withcementing electrons.Further, the helium nucleus consists of fourhydrogen nuclei, together with two cementing electrons, the loss ofmass being due t o the packing effect. The helium nucleus is themost stable configuration of all, whilst next in order of stabilitycomes the group of atoms or even atomic number. An interestingfact arises in connexion with the number of hydrogen nuclei whichare associated with the helium nuclei in the second class of elements.I n the case of the lighter elements with odd atomic number thisnumber is always three save in the exceptional case of nitrogen,A. Piutti and E. Cardoso, J . Chim. phys., 1920,18, 81 ; A., ii, 311.W. D. Harkins, Physical Rev., 1920,15, 73 ; A., ii, 47930 ANNUAL REPORTS ON TRE PROGRESS OF CHEMISTRY.where it is two.The extremely frequent occurrence of this groupof three hydrogen nuclei suggests that it probably occurs alone as aunit with a nuclear charge equal to 1 and atomic weight of 3, andtherefore structurally it will be an isotope of hydrogen. If thehypothetic nebulium exists a t all it is probably this form of hydro-gen, and it is interesting that from a study of the Diippler effectthe atomic weight of this element has been found to be about 3.3Now there is one point in connexion with the Harkins theorywhich requires consideration. If; for example, the elements witheven atomic numbers are formed from helium nuclei, why is it thatthey are not inore unstable in view of the fact that the heliumatom is thz most stable form? It would seem necessary to con-clude that the elements are metastable, and that they are able toexist owing t o their possessing an external force field. I f this isbroken by the supply of energy, then the atomic nucleus willbecome unstable.I f this principle of external fields is accepted,then it only becomes a question of supplying the right amount ofenergy to the hydrogen atom for the association to become possibleof three or four nuclei to form H3 or helium. On the Harkinstheory, therefore, there is no reason against the production of H3and helium 111. vacuum tubes from hydrogen if the discharge em-ployed produces the suitable type of energy. Indeed, such aphenomenon is rather to he expected than denied in view of thestability of the helium nucleus.The writer is therefore all themore encouraged to insist on the correctness of his suggestion madein 1914 that the contradictory results obtained by Thomson, Collie,Patterson, and Masson on the one hand, and by Strutt, Piutti andCardoso on the other, are due to the absence of sufficient energy ofthe right kind in the latter and negative experiments. There aretwo alternative possibilities as to the nature of the energy requiredto break open the fields of the hydrogen atom. It may either beradiant energy of short wave-length or it may be energy given byrapidly moving particles. The production of either of these in agiven vacuum tube varies remarkably with the conditions. Theimportance of this work has undoubtedly increased, and it is amatter of some moment that the question as to the production ofhelium from hydrogen be decided.Reference may here be made t o a branch of investigation which,although not chemical, must possess great interest for the inorganicchemist, namely, stellar development.According to the modernviews of astro-physicists there is little doubt that in the stars adevelopment process is taking place whereby the chemical elementsare being synthesised from hydrogen and helium as parents. Now3 C. Fabry and H. Buisson, Astrophys. J., 1914,4, 256INORGANIC CHEMISTRY. 31i t would seem fairly certain from a study of the spectra and rota-tional velocities of certain nebulae, particularly the one in Orion,that the original inaterial from which the synthetic process startsis nebulium, which as the first stage in the process forms hydrogenand helium. When it was discovered that the probable atomicweight of this gas is 3, it appeared somewhat incomprehensible thata synthetic process should give both hydrogen and helium.In allprobability, on the basis of Harkins' theory that nebulium is H, thefirst stage is the formation of hydrogen, which then associates togive heliiini, which in its turn associates to give elements of evenatomic numbers. I f this is so, by far the greatest amount of con-densation will take place in the direction of the elements of evenatomic numbers. The great predominance of elements of this classhas been pointed out by Harkins, who offers two explanations ofthe relative scarcity of the elements with odd atomic numbers whichconsist of helium and N, atoms.First, their scarcity may be duets their relative instability, and secondly, there may have beenpresent during the synthetic process relatively little H3. The firstalternative is unsatisfactory, for a t present there seems little, if any,direct evidence that the elements of odd atomic numbers are lessstable than their fellows. The second alternative fits in very wellwith the present suggestion, since, if the first stage is the pro-duction of hydrogen from H,, and the second stage is the formationor" helium from the hydrogen, it is probable that in any laterassociat'ion there will be present only small amounts of H,. TheHarkins theory would therefore fill an undoubted gap in thetheories of stellar development.An important paper has appeared during the year on the massspectra, or positive ray spectra, of the elements by Aston, whodescribes his apparatus in detail and the most recent results hehas ~ b t a i n e d .~ The principle of the method consists in producingthe positive rays with a given element and passing them throughslits. The rays also pass through an electric field and a magneticfield, and then impinge upon a photographic plate. A focussedspectrum is obtained in which the lines depend solely on the ratioof mass to charge. By varying the strengths of the two fields, anydesired line may be brought on to the centre of the plate.All themeasurements of the positions of the various lines are relative, andso one element must be taken as standard, and for this purposeoxygen was selected. The molecule of oxygen carries one charge,whilst the atoms carry one or two charges, with the result that withthis gas three lines are obtained. The three lines are obtained a tthe scale readings 32, 16, and 8 respectively. Direct comparison4 F. W. Aston, Phil. Mag., 1920, [vi], 39, 611 ; A., ii, 34432 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the carbon, carbon monoxide, and carbon dioxide lines withthese standards gave C++ (6), C (la), CO (28), and CO, (44).Clearly, therefore, the whole number relation and the additive lawhold within the iimit of accuracy, which is one part in a thousand.The following results have been obtained with eleven elements.Neon, with an atomic weight of 20’2, gives two well-defined lineswhich correspond with masses 20 and 22 respectively.This gas,therefore, consists of two isotopes, with possibly a third, of mass 21,since there was observed a very faint line in this position.Chlorine shows four very definite lines, corresponding with masses35, 36, 37, and 38, with no indication whatever of a line corre-sponding with its atomic weight of 35-46. There is no escape, there-fore, from the conclusion that chlorine is a mixture of isotopes, andthat two of these have masses 35 and 37. Whilst the lines 36 and38 may be due to two more isotopes, it is more probable that theyare given by the hydrogen conipounds of the two isotopes withmasses 35 and 37.Strong lines were also observed a t 63 and 65,due, no doubt, to the carbonyl compounds of the two isotopes.Again, if ordinary chlorine of average atomic mass 35-46 is amixture of two isotopes 35 and 37, it is evident that the line of35 should be stronger than the line of 37, and this was actuallyfound to be the case. A faint line was distinguishable a t 39, whichpossibly is due to a third isotope.Argon shows three strong lines at 40, 20, and 13.33, which clearlycorrespond wikh particles of mass 40, carrying 1, 2, and 3 chargesrespectively. A faint companion was seen a t 36, which is doubtlessdue to an isotope present in small amounts. Tbe presence of about3 per cent. would account for the fractional atomic weight deter-mined from the density.Nitrogen gives a line which cannot be distinguished from that ofcarbon monoxide, and a second line a t 7, due to a doubly chargedparticle. Evidently, therefore, no isotope is present and nitrogenis a pure element.The measurements with hydrogen were more troublesome, owingto the fact that the position of the lines is so far removed from thereference standards. The difficulty was surmounted by comparinghelium with the doubly charged atoms of oxygen and carbon (8 and6), T’homson’s H, with carbon and helium, and hydrogen withhelium.T‘he results show definitely that both hydrogen and heliumare pure elements, and that the mass of the helium atom is 4. Themean value for the mass of H, is 3.026, and that for the mass of thehydrogen molecule is 2.015.The atomic mass of hydrogen, there-fore, is clearly 1.008, and the nature of the H, molecule is settledbeyond questionINORGANIC CHEMISTRY, 33Krypton was found to exhibit perfectly definite evidence of beinga mixture of five isotopes of masses 30, 82, 83, 33, and 86, with aprobable sixth of mass 78. Measurements of these lines were madewith singly, doubly, and trebly charged particles. There wouldseem, 8140, to be five isotopes present in xenon, with masses 128,130, 131, 133, and 135, but as only a minute quantity of this gaswas available these results are only provisional.Mercury was also found to be complex, for the lines observedindiczte the presence of a strong component 203, and a weak one204.There is also a strong band from 197 t o 200, indicating three orfour more componenls, but up t o the present this band has notbeen resolved.Perhaps the most important generalisation that can be made from.this work is the quite remarkable fact that with the exception ofH, and €I, all masses, atomic and molecular, elementary and com-pound, so far measured are whole numbers within the accuracy ofexperiment. The number and variety of substances studied makethe probability of this being true for all elements extremely great.It certainly allows of hypotheses being put forward of atomicstructure far simpler than those which attempted t o explain frac-tional atomic weights, since these now appear t o be merely for-tuitous statistical effeciis, due to the relative quantities of theisotopic constituents.Thus it may now be supposed that an ele-mentary atom of mass M may be changed to one of mass M + 1 bythe addition of a positive particle (H) and an electron. I f bothenter the nucleus a n isotope results, for the nuclear charge is un-altered. I f the positive particle alone enters the nucleus, anelement of the next higher atomic number is formed. When bothforms of addition give a stable configuration the new elements willbe isobares.Apart from the intrinsic value of Aston’s work, its importancebecomes very pronounced when considered along with theories ofthe nuclear structure of atoms. These lead undoubtedly tointegral values of atomic weights, and Harkins explains thedivergence from whole numbers by the existence of isotopes.These isotopes have now been shown by Aston t o exist, and it isof interest to note that Harkins has obtained evidence of theseparation of chlorine into two isotopes by diffusion experimentswith hydrogen chloride.5On the other hand, Rutherford6 has published further experi-mental data which, to a certain extent, do not fit in with Harkins’theory.When the swiftly moving particles from radium4 passW. D. Harkins, Science, 1920, 51, 289.6 (Sir) Ernest Rutherford, Proc. Roy. SOC., 1920, [A], 97, 374 ; A., ii, 541.REP.--VOL. XVII. 34 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.through nitrogen, some of the atomic nuclei of this gas are dis-rupted, and, as is now well known, hydrogen atoms are produced.Hydrogen atoms are not produced in oxygen under the same con-ditions.It is found, however, that both oxygen and nitrogengive slower moving particles of mass 3 with charge 2. Thenitrogen nucleus, therefore, can be disintegrated in two ways, oneby the expulsion of the hydrogen atom, and the other by theexpulsion of an atom of mass 3 carrying two charges. Since theseatoms of mass 3 are five to ten times as numerous as the hydrogenatoms, it appears that these two forms of disintegration areindependent and not simultaneous. It would follow also that thenew atom when it has gained two electrons should have physicaland chemical properties very nearly identical with those of helium,but with mass 3 instead of 4.The spectra of helium and thisisotope should be nearly the same, but, on account of the markeddifference in the relative masses of the nuclei, the displacement ofthe lines should be much greater than in the case of the isotopesof heavy elements like lead. It is very improbable that this isotopeis connected with nebulium.I n dealing with the nuclear constitution of the lighter elements,Rutherford naturally assumes that the new helium isotope formsan integral part of these nuclei. Thus he suggests that the carbonatom consists of four atoms of the helium isotope and that thenitrogen atom consists of four of these isotopes and two hydrogenatoms, whilst the oxygen atom is built up of four helium isotopesand one helium atom. It will be seen at once that there is anessential difference between this view and that put forward byHarkins, who considers that the carbon and oxygen atoms consistof three and four atoms, respectively, of ordinary helium.Now there seems no doubt that the helium isotope discovered byRutherford is a different entity from H,, which forms an integralpart of Harkins' theory, was first discovered by Thomson, nowconfirmed by Aston, and has recently been directly prepared bythe activation of hydrogen.7 Aston has definitely shown that H3carries one charge, and this fact, considered along with its form-ation from hydrogen, shows that i t is an isotope of hydrogen.There thus exist two elements of mass 3, one an isotope of hydrogenand the other an isotope of helium.It is not possible yet to saydefinitely whether either alone or both together take part in atomicnuclear synthesis.I n this connexion, the writer would draw attention t o the veryremarkable permanent contraction suffered by hydrogen when it' G. L. Wendt and R. 8. Lmdauer, J . Amer. Chem. SOC., 1920, 42, 920;A., ii, 425INORGANIC! CHEMISTRY. 35has been activated and lost its activity. This point is detailed inthe section of this Report dealing with the first group of elements.Wendt and Landauer assume, of course, that H,, on keeping,regenerates ordinary hydrogen, but is i t absolutely certain that thisis th’e case? Collie’s results on the formation of helium in vacuumtubes containing hydrogen, his collateral results on the permanentdiminution in the volume of hydrogen in vacuum tubes, consideredin connexion with the theories of atomic nuclear structure, leadinevitably to the conclusion that H,, on keeping, gives little H,,but mainly helium.Although this suggestion may sound veryimprobable to many, it is, in reality, far more probable than anordinary chemical explanation, since it is scarcely possible to con-ceive that H, in the presence of nitrogen would not form ammonia,but prefer to react with the glass of the reaction vessel. Thissuggestion has been privately communicated to Dr. Wendt.Atomic W e i g h t s .The Report of the International Committee recommends onlyone change, namely, that the atomic weight of scandium should beraised from 44.1 to 45.1. The work of Honigschmid, on which thenew value is based, was referred to in last year’s Report.Three series of determinations have been made of the atomicweight of tin.Two of these involved the analysis of tin tetra-bromide by silver,BJg and the third depended on the direct electro-lytic estimation of tin in the tetrabromide.1° The values obtainedwere 118.700, 118.699, and 118.703, respectively, which agree verywell with the accepted1 value.The weight of a normal litre of methyl fluoride has been foundto be 1.54542 grams as the mean of twenty-three determinations.11From this, the atomic weight of fluorine is deduced as 18.996,which is very close to the accepted value of 19.Some determinations have been made of the atomic weight ofsamarium by the anhydrous chloride-silver ratio.12 As the meanof eighteen determinations, the value of 150.43 was obtained.In addition to the above, the following investigations may bereported.A determination has been made of the atomic weightof silicon by the analysis of silicon tetrachloride.13 The mean of* B. Brauner and H. Krepelka, J. Amer. Chem. SOC., 1920, 42, 917; A.,ii, 437. H. Krepelka, ibid., 925 ; A., ii, 437.lo G. P. Baxter and H. W. Starkweather, ibid., 905 ; A . , ii, 436.l1 E. Moles and T. Batuecas, J . Chim. phys., 191 9, 17, 537 ; A., i, 283.12 A. W. Owens, C. W. Balke, and H. C. Kremers, J. Amer. Chcm. Xoc.,1s G. P. Brtxter, P. F. Weatherill, and E. 0. Holmes, jun., ibid., 1194 ;1920, 42, 515 ; A., ii, 316.A., ii, 487.c 36 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.four experiments gave the value of 28.11, but as this is notaccepted as final by the authors, this value must await confirmation.By the analysis of bismuth chloride, a new value for the atomicweight of bismuth has been obtained.l4 The ratio BiC13:3AgClgave 209.024, and the ratio BiC13:Ag gave 209.027.The meanvalue 209.026 is one unit higher than the value a t presentaccepted.Colloids.A few papers have appeared on the preparation and propertiesof inorganic colloids, and mention may be made of the following.A convenient method for the preparation of metallic sols15 is tostrike an arc between poles of the metal under alcohol, usingcapacity in the circuit. With a current of 1.5 amperes and acapacity of 12-8 x MF, colloidal solutions have been obtainedof aluminium, antimony, bismuth, cadmium, copper, gold, lead,platinum, silver, and zinc. The colloidal metal is produced muchmore rapidly than by the earlier Sveciberg method.The stabilityof the sols is fairly great, and although a certain amount alwaysseparates, the bulk of the metal remains in solution. Gold andplatinum are exceptional, since their sols are very unstable.Colloidal rhodium16 has been prepared by the addition of aslightly alkaline solution of formaldehyde to a slightly alkalinesolution of the double chloride, Na,RhCl,, the reduction beingcarried out a t 40°. Under these conditions, a clear, colloidalsolution of rhodium is obtained. This solution absorbs hydrogento the extent of 2510-2960 times the volume of rhodium present.Similarly, the rhodium absorbs 346 times its volume of carbonmonoxide at 12-14O, and 1820 times its volume a t 60°.Thecolloidal solution, slightly alkaline, causes a very slight combinationof nitrogen and hydrogen to give ammonia, the reaction being coii-siderably enhanced if the solution is made just acid with verydilute tartaric acid in the presence of potassium tartrate.Mention may also be made of some work on the preparation andstability of mercury sols.l7 The most coiicentrated solution isobtained by passing a rapid stream of mercury vapour into coldwater, but in every case the sols are not very stable. Theirstability is materially increased by the use of gum arabic as aprotective colloid.l8l4 0.Honigschmid and L. Birckenbach, Zeitsch. Elektrochem., 1920,26, 403 ;A., ii, 549.l5 G. Borjeson and T. Svedberg, Kolloid Zeitsch., 1919, 25, 154 ; A., ii, 31.l6 C. Zenghelis and B. C. Papaconstantinou, Cornpt. rend., 1920,170, 1058 ;l8 A. Gutbier and G. L. Weise, ibid., 1919, 25, 97 ; A., ii, 36.A., ii, 380. l7 I. Nordlund, Kolloid Zeitsch., 1920, 26, 121 ; A., ii, 376INORGANIC CHEMISTRY. 37The Rare Gases.Mention must be made of McLennan’s work on the productionof helium on the large scale from natural gases.19 A large numberof gases from natural sources in various countries was investigated,and the Bow Island gas supplied to the town of Calgary, in Alberta,was selected. This gas consists of methane 91.6, ethane 1.9,nitrogen 6.14, and helium 0.36 per cent., together with traces ofcarbon dioxide and water vapour.It is not possible to givedetails of the experimental plant employed, which followed thelines of the Claude oxygen-producing column. By its means, intwo stages of working helinm, was obtained of 87-90 per cent.purity. By the use of a second plant, this was further purifiedt o 98-99 per cent. From the experience gained with these experi-mental plants, specifications have been drawn up for a commercialplant t o deal with the whole of the Bow Island supply of gas. Sixunits are proposed, each dealing with about 62,000 cubic feet perhour, the average daily supply of gas being 9,500,000 cubic feet.The yearly output of helium of 97 per cent. purity would be about10,500,000 cubic feet, and the working cost would be considerablyless than 219 per 1000 cubic feet.Group T.A most interesting paper has been published on the formation 20of triatomic hydrogen by various means from ordinary hydrogen.Hydrogen a t atmospheric pressure, when submitted to the actionof a-rays from radium emanation or passed through a silent dis-charge tube, is converted into an active form, and a similar resultis obtained when the electric discharge from a large induction coilor transformer is passed through a vacuum tube, through whichhydrogen is passed under a pressure of 2-8 cm.I n each case, asmall amount of an active form of hydrogen is produced, which isat once condensed on passing the hydrogen through a spiral tubecooled in liquid air.This active modification reacts with sulphur,arsenic, phosphorus, mercury, and nitrogen, and also reduces acidand neutral solutions of pota.ssium permanganate. The amountof hydrogen that is converted into the active form in the experi-ments described has not exceeded 0.02 per cent.Very careful experiments have proved that the enhancedreactivity is not due t o the presence of ions, and also the substance2o G. L. Wenat an.d It. S. Landauer, J. Amer. Chem. SOC., 1920, 42, 930;J. C. McLennan, T., 1920,117, 027.L4., ii, 42538 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.differs in its chemical and physical properties from atomic hydrogenprepared by Langmuir, which was referred to in the Reports for1912 and 1915. The polyatomic nature of the substance isindicated by the contraction in volume of the hydrogen when i t isformed, and, moreover, positive ray analysis has shown the un-doubted existence of H, molecules when the electric discharge ispassed through hydrogen a t low pressures.There is little doubtbhat the substance is indeed H,.It is very unstable, and disappears very rapidly after it hasbeen formed. This was shown by the increased reactivity that isobserved when the flow of hydrogen through the silent dischargetube is increased. A t atmospheric pressures it is found that thereactivity disappears within about one minute.Perhaps the most interesting phenomenon in these experimentsis the permanent contraction that takes place in the hydrogen.This was noticed by Usher,21 who carried out experiments on thesynthesis of ammonia by exposing a mixture of hydrogen andnitrogen to the action of a-rays from niton mixed with the gases.I n one case, a contraction of 0*24 C.C.was observed, but only0.006 C.C. of ammcnia had been formed. Collie and’ Patterson22observed a similar disappearance of 3.6 C.C. out of 4.6 C.C. ofhydrogen when the gas was sparked under reduced pressure withcopper or aluminium electrodes. A possible explanation of thisphenomenon is put forward in an earlier section of this Report,and it would, indeed, seem that this may prove to be even moreinteresting than the preparation of H,, great as is the importanceof this advance.Investigation has shown that lithium behaves similarly t o sodiumand potassium iii forming soluble silicates containing a large excessof the acid over the base.23 Lithium metasilicate, Li2Si0,, hasbeen prepared in an insoluble and a soluble modification, theformer having the formula Li2Si0,,R20 .Brief reference may be made to some experiments on the actionof alcohol on the sulphates of sodium.” Dry alcohol acts on drysodium hydrogen sulphate to give the intermediate sulphate,Na,SO,,NaIISO,, and free sulphuric acid, which dissolves in thealcohol. No action takes place with potassium hydrogen sulphate.I n the presence of moisture, sodium hydrogen sulphate is firstconverted into the intermediate sulphate, and then, finally, into21 F.L. Usher, T., 1910, 97, 389.22 J. N. Collie and €1. S. Patterson, P., 1913, 29, 22, 217.28 I<.A. Vesterberg, Medd. K . Vctenakapsakad. Nobel-Inst., 1919, 5, No. 30 :24 G. S. Butler and H. B. Dunnicliff, T., 1920, 117, 649.A., ii, 112INORGANIC CHEMISTRY. 39ordinary sodium sulphate. When an alcoholic solution of sulphuricacid (20 per cent. or less) acts on sodium sulphate in the cold, theintermediate sulphate is formed. Nitre cake consists ofNa2SO,,NaHSO4 alone or mixed with either NaHSO, or Na,SO,,according as the acidity is equal to, greater than, or less than,18 per cent. H,SO,.A process has been patented for the preparation of metallicpotassium by heating potassium hydroxide and sodium in exactlyequivalent proportions a t 670° in the absence of air.25 Hydrogenis produced and the potassium is volatilised and may be condensed.Some further and, it may be said, conclusive work has beencarried out on the possible existence of an alkali metal of higheratomic weight than cmium.2G The alkalis were separated from3500 grams of pollucite, which contains more than 30 per cent.ofmsium oxide, and the mixture was carefully tested for the presenceof the next higher homologue to czesium. There is no need todescribe the experimental details, but no indication whateverwas found of the presence of a new element.Group 11.A study has been made of the equilibrium conditions whichobtain between arsenic oxide, calcium oxide, and water a t 3 5 O forthose mixtures in which the arsenic oxide is in excess.27 Evidencewas found of the existence of two orthoarsenates of calcium, namely,dicalcium orthoarsenate monohydrate, CaHAs0,,H20, and mono-calcium orthoarsenate, CaE,(AsO,), .The former is identical withthe mineral haidiiigerite, and is stable in contact with a solutioncontaining more than 27.5 per cent. of arsenic oxide, whils't thelatter is stable with a lower percentage of arsenic oxide in thesolution.Mention may be made of the fact that chlorine has no action oncalcium carbide, whilst liquid bromine slowly reacts to give hexa-bromoethane and calcium bromide.28 The reaction is very slow,and 4.5 grams of the finely-powdered carbide treated with 45 gramsof dry bromine for five weeks gave 22 grams of hexabromoethane,5.8 grams of calcium bromide, and 0.2 gram of unchanged carbide.Reference was made in the Report for last year to the fact thatthe decomposition of bariuw? peroxide takes place a t a much lowertemperature in the presence of silica, a certain amount of bariumF.C. Wickel and TV. Loebel, D.R.-P. 307175 ; A . , ii, 32.26 L. M. Dennis and R. W. G. Wyekoff, J. Amer. Ckem. SOC., 1920,42,98528 E. Barnes, Cham. NEWS, 1919, 119, 260 ; A . , ii, 33.A., ii, 431. 27 C. N. Smith, ibid., 259 ; A . , ii, 37540 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.silicate being formed. The influence of a great number of otheroxides has now been studied by examining the heating curves ofthe mixtures in molecular proportions.29 Cuprous oxide reactsviolently with barium peroxide t o give cupric oxide, which decom-poses barium peroxide catalytically, the optimum t'emperature beingabout 660O.Biagnesiuin 2nd calcium oxides start the decompositiono i the peroxide at 250" and 310° respectively, whilst zinc oxidecauses slow deconiposition between 200° and 370° and forms bariumzincate. Zirconium oxide, stannous oxide, and stannic oxide haveno action, but the oxides of cadmium, lanthanum, and cerium actas pure catalysts. Aluminium oxide forms barium aluminate, andtitanium oxide in niolecular proportions gives a titanate, probablyBaTi03. With twice the molecular proportions of barium peroxidea basic titanate is produced. Litharge and barium peroxidebetween 300° and 400° evolve no oxygen, but form a brown sub-stance of unknown composition. Above 500° much oxygen isevolved, with the probable formation of Ba,PbO,.Vanadium pent-oxide reacts vigorously with barium peroxide. When eqnimolecularproportions are used, the reaction begins a t 2 1 5 O and is endeda t 530*, Ba(V03), being formed. With 2Ba0, the metavansdate isfirs6 formed, but ab 3 7 5 O a second, very vigorous, reaction startsand the colour changes from brown to white, the product apparentlybeing Ba,V,07. Tantalum pentoxide also reacts vigorously t o givea tantalate. With arsenious oxide and three moleciiles of bariumperoxide, arsenic oxide is first formed a t 310° to 410°, and above4 6 5 O oxygen is evolved and barium arsenate is formed. Withantimony oxide at ZOOo oxygen is evolved with almost explosiveviolence. Bismuth oxide stsrts a gradual evolution of oxygen a tabout 250°, and higher bismuth oxides, or compounds of these withbarium peroxide, appear t o be formed.With chromium oxide nooxygen is evolved, and barium chromate is produced. The oxidesof molybde~ium, tungsten, and uranium all cause evolution ofoxygen and form molybdates, tungstates, and uranates respectively.The kwer oxides OF manganese are all oxidised and give bariummanganate. Ferric oxide acts catalytically, and gives bariumferrate, whilst nickel and cobalt also act catalytically and arechanged into higher oxides, which do not agree in their propertieswith the known peroxides o l these metals.It has besn found that strontium sulphide is readily hydrolysedby water t o give equiinolecular proportions of the h ydrosulphideand the hydroxide.30 These two compounds do not form a niixed2 0 J.A. Hedvall and N. von Zweigbergk, Zeksch. anorg. Chem., 1919, 108,119 ; A., ii, 35.3 0 M. Bruckner, Zeitsch. Elelctrochem., 1920, 26, 25 ; A., ii, 251JNORGANlC CHEMISTRY. 41compound, and the hydroxide may be separated by crystallisation.When strontium sulphide is extracted with hot water and the clearfiltrate cooled, pure strontium hydroxide, Sr(OH),, crystallises.The case is different with barium sulphide, as the hydroxide andhydrosulphide . form an additive compound, OH*Ba*SH,5H20.31Under no conditions can pure barium hydroxide be crystallisedfrom the solution obtained by the action of water on bariumsulphid e.From a study of the equilibrium between zinc oxide, phosphoricoxide, and water a t 2 5 O and 37O, the following phosphates of zinchave been found to exist : Zn3(P0,),,4H,0, ZnHP0,,3H20,Zn(HZP0,),,2H,O, whilst a t 3 7 O an additional salt, ZnHPO,,H,O,is obtained.32 Similar investigations with sodium hydroxide solu-ticns and zinc oxide have established the existence ofNa20,Zn0,4H,0 8s a stable compound.33Group 111.An investigation has been made of the equilibrium conditionsbetween alinminium nitrate, nitric acid, and water a t 25O, and itwas found that three hydrates of the salt have a stable existence.34The first, Al(N0&,l8H2O7 is most stable in contact with the solu-tion containing 73 per cent.or less acid, the second,Al(N03)3,16H,0, is stable with 73-81 per cent. acid, whilst thethird, A1(NO,),,12H2O, is stable in the presence of more than 81 percent.of nitric acid.Some phjsical measurements have been made of the solutionsobtained by dissolving aluminiwm in aqueous solutions of sodiumhydroxide and of ainmonium hydroxide.35 Whilst the physicalaspect of this work does not fall within the purview of this Report,the results have some value for inorganic chemists. It is shownthat aluniiniuni hydroxide aeulralises the alkalis as a monobasicacid, and that the aluminates are salts of the acid HAl(OH),, thatis, Al(OII),,H,O. Ammonium aluniinate, NH,Al(OH),, is quitestable in solution.Some further work may be reported on scandium fluoride andthe scandifluorides.36 The best method for the preparation of the31 K. Bruckner, Zeitsch.Elektrocherrz., 1920, 26, 1 ; A., ii, 252.32 N. E. Eberly, C. V. Gross, and W. S . Crowell, J . Arne).. Chein Xoc., 1920,33 F. Goudriaan, PTOC. K. Akad. Wetensch. A4msterdam, 1919, 22, 17934 K. Inamura, J. Tokyo Ckern. SOC., 1920, 41, 1 ; A., ii, 625.35 J. Heyrovskf, T., 1920,117, 1013.36 J. Stgrba-Bob, Bull. SOC. chim., 1920, [iv], 27, 185 ; A., ii, 315.42, 1433 ; A., ii, 545.A., ii, 113.C42 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.pure fluoride is by the action of hydrofluoric acid on scandiumoxide, the product being finally heated a t 150-180O in order t oremove the excess of hydrofluoric acid. Whilst the free scandi-fluoric acid does not exist, two new ammonium scandifluorides havebeen prepared. The salt, (NH4),ScF,,37 is hydrolysed in thepresence of ammonium fluoride to give in quadratic crystals thesalt, (NH&3cF5.I n warm or cold water alone the salt,(NH4)ScF,, is always obtained as a microcrystalline powder. Bythe dissolution of scandium fluoride in a concent,rated solution ofsilver fluoride a scandifluoride of silver is formed.It is known that lead nitrate and nit,rite interact in solution togive well-defined compounds containing both salts. Similarly, thal-lium nitrite and lead nitrate react to give basic compounds of bothsalts.,' In the case of potassium nitrite and thallium nitrate nosuch double salts are obtained, but thallium nitrate-nitrites areformed which are stable and can be crystallised unchanged. Withtwo molecules of potassium nitrite and one molecule of thalliumnitrate the compound formed has the formula Tl,N,O,.With dif-ferent proportions other salts are obtained, in which the ratiobetween nitrate and nitrite is not a simple one.Since last year's Report was written Sir Charles Parsons haspublished a complete account of his experiments on the artificialproduction of diamond.39 It is shown beyond any doubt that highpressure alone is not sufficient to cause the conversion of graphiteinto diamond, and it is also shown that iron must be present. Ex-periments in which a mixture of acetylene and oxygen is highlycompressed and a temperature produced in excess of that requiredto vaporise carbon, accompanied by a momentary pressure of 15,000atmospheres, prove that the failure to produce diamond is not dueto lack of temperature.Many of the experiments, in which it hasbeen claimed that diamond is produced, have been repeated, andnegative results were obtained unless iron played a part. Experi-ments under vacua from 75 mm. up to X-ray vacua have showngenerally that as the pressure is reduced the yield of diamond isdiminished. On the other hand, when alloys, previously boiledunder atmospheric pressure, are quickly heated in a high vacuum,violent ebullition takes place, due t o the large volume of gasesliberated, and some of the contents of the crucible are ejected before37 R. J. Meyer, Zeitsch. anorg. Chem., 1914, 86, 257 ; A., 1914, ii, 369.38 L. Rollo and G. Belladen, Gazzetta, 1919, 49, ii, 217 ; A . , ii, 34.lS (Sir) C.A. Parsons, Phil. Trans., 1919, [A], 220, 6 7 ; A., ii, 110INORGANIC CHEMISTRY. 43they have time to part with their occluded gas, and diamond occursin the spherules so ejected. There is no doubt that these gases,possibly containing a ferro-silicon carbonyl, are necessary for theproduction of diamond. It seems alniost certain that the chieffunction of quick cooling in the production of diamond in an ingotor spherule is to bottle up and coiicentrate into local spots the gasesoccluded in the metal which, under slow cooling, would partlyescape, whilst the remainder would become evenly distributedthrough the mass. The necessity of subjecting the iron to a tem-peratnre above 2000° before cooling would imply the necessity ofcarbides of silicon, magnesium, etc., being present t o ensure thenecessary chemical reactions with the gases a t high pressure withinthe ingot.The greatest percentage of diamond was obtained whenthe atmosphere round the crucible consisted of 95 per cent. ofcarbon monoxide, 1 per cent. of hydrogen, 2 per cent. of hydro-carbons, and 2 per cent. of nitrogen. The weight of diamond wasabout 1/20,000 that of the iron. It seenis probable that the rateof cooling might be so prolonged as to obtain much larger crystalsand a larger total yield.The presence of crystals of SiO,, Al,O,, and MgO, the spinels, andpyrope, associated with diamond in rapidly cooled iron alloys,appears to have a bearing on the presence of similar crystalsfmnd in association with diamond, and to be compatible withBonney’s view that eclogite is the parent rock of the diamond inSouth Africa.It seems probable that both the eclogite and thediamond may have been siinultaneously crystallised from an ironalloy. Since the average weight of diamond in the blue groundof South Africa is 1 in 5,400,000, there has been produced in coolediron more than 270 times this amount.Investigations were made during the war of the absorptive poweror” various vegetable charcoals and the improvement that is causedby heat treatment. These have now been published in part, andin the first paper the effect of heat treatment on the absorptivepower of sugar charcoal for sulphur dioxide is de~cribed.~O Afterheating the charcoal for forty-five hours the amount of sulphurdioxide absorbed per gram was increased from 97 C.C.to 288 C.C. I na second paper exactly analogous results were obtained, and apossible explanation is suggested.41 The main experiments werecarried out with birch-charcoal, but other wood charcoals were used.The absorptive powers were measured with sulphur dioxide, carbondioxide, and also aqueous soluticns of methylene blue. It wasfound that the absorptive power is very materially increased by40 R. M. Winter and H. B. Baker, T., 1920,117, 319.41 J. C. Philip, S. Dunnill, and (Miss) 0. Workman, ibid., 362.a* 44 ANNUAL REPORTS ON TRE PROGRESS OF CHEMISTRY.the heat treatment, with the result that the activity of animalcharcoal can be paralleled and even surpassed by wood charcoal.It was noticed that the heat-treatment is not the only factor inenhancing the activity, and the clue was found in the decrease inthe bulk density of the charcoal during the heating process.Ifthe heating is carried out in the absence of oxygen little or no im-provement jn the activity is produced, and oxygen must be presentfor the activation to take place. The explanation is probably thatin the case of a freshly prepared sample the capillaries through thematerial are exceedingly small, so that they are soon blocked whenabsorption takes place. When the charcoal is heated in the presenceof oxygen some oxidation takes place, and the capillaries becomewider, so that the effective surface is enormously increased.A convenient method has been described for the removal of carbonmonoxide from its mixtures with other gases for analytical andhygienic purposes.42 The carbon monoxide is very rapidly oxidisedby chromic acid solution to which some mercuric oxide has beenadded.Some further work on the derivatives of the silicon hydricles maybe reported .43 It was previously shown that dibromomonosilanereacts with water to form polymerides of protosiloxane, O-SiH,.The unimcllecular form has now been obtained as a gas by the actionof the required amount of water-vapour on dichloromonosilane in avery large flask under greatly reduced pressure.The compound hasan extraordinary tendency t o polymerise, in consequence of whichthe flask nimi be perfectly clean and smooth. Liquid and solidpolymerides are formed immediately on condensation.The liquidones are like benzene, and c m be conveniently obtained as a solu-tion by shaking a benzene solution of dichloromonosilane withwater. They correspond approximately with the formula (SiH,O),.The solid polymerides are insoluble. All the polymerides react withsodium hydroxide in accordance with the equation SiH,O +2NaOlI = Na,Si03 + ZH,.The behaviour of disilane, Si,H,, towards halogen acids has beeninvestigated, and is found closely t o resemble that of monosilane.Disilane does not appear to react yith hydrogen chloride a t theordinary temperature or a t 120°, bnt in the presence of a little sub-limed aluminium chloride a reaction occurs more or less readilyaccordng to the general scheme :Si,K, + zHCl= Si,H,-, Clx + zH.A mixture of chlorides is invariably produced, the equilibrium lying42 K.Hofmann, ~9.22.-P. 307614 ; A , , ii, 309.43 A. Stock and K. Somieski, Ber., 1919,52, [B], 1851 ; 1920,53, [B], 759 ;A., ii, 31, 429INORGANiC CHEMISTRY. 45in favour of the intermediate members of the series. Thus withhydrogen chloride (1 val.) and disilane (less than 1 vol.) the mainproduct is dichlorodisilane, very little inonochlorodisilane beingobtained. With the gases in the volume ratio 2 : 1 much trichloro-disilane, in addition t o dichlorodisilane, is obtained. Completechlorination is not effected by a large excess of hydrogen chloride.It was not found possible t o isolate monochlorodisilane in a purestate, and also the final purification of dichlorodisilane could not beeffected, since it forms a mixture of constant boiling point withtrichlorodisilane.There is no doubt that as in the case of thecarbon compounds mixtures of isonierides are formed in the halogen-ation of disilan e.The brominatisii of disilane has been carried out in a preciselyanalogous manlier, and monobromodisilane, m. p. - looo to - lolo,has been isolated in a state of purity.The hydrolysis of the halogenated disilanes corresponds exactlywith that of the similar monosilanes. Thus monobromodisilanereacts with water t o yield the substance (Si,H,),O, a colourlessliquid which can be volatilised without decomposition, and, whendissolved in benzene, instantaneously reduces cold silver nitrate,but not copper sulphate, solution.It reacts slowly, but quantita-tively, with sodium hydroxide solution in accordance with theequation (Si,H,),O + 8NaOH + 3H,O = 4Na,SiO, + 12H,. The solidproducts obtained by the hydrolysis of dibromodisilane and themore highly halogenated derivatives closely resemble silico-oxalicacid, (HOzSi*SiO,H)x. They are only slowly hydrolysed furtherby water, can be dried in a desiccator without marked decomposi-tion, evolve hydrogen when treated with alkali hydroxide, andfinally yield a residue of silicate. Evidently the Si-Si linkingremains intact in them, and appears to be more stable towardsalkali than was a t first thought.Amorphous zirconiuni may be obtained from potassium zirconiumfluoride by means of sodium or aluminium, and the coherent forincan be prepared from the sane salt by aluminothermic reduction.44The coherent metal is much less chemically active than theamorphous variety, and, unlike the latter, is insoluble in all acidsexcept hydrofluoric acid and aqua regia.It has been shown that zirconium monoxide does not exist, theblack powders obtained by the reduction of the dioxide bymagnesium being mixtures of the metal and the dioxide.45The iodates, perchlorates, and a chlorate have been prepared of44 J.W. Marden and M. N. Rich, J . Ihd. Zng. C'hern., 1920, 12, 661 A.,4s R. Schwarz and H. Deisler, Ber., 1919, 52, [B], 1896 ; A., ii, 42.ii, 54746 ANNUAL REPORTS ON THE PROGRESS 03' CHEMISTRY.zirconium.465Zr0(OB)2,8ZrO(103)2, 3Zr0(OH)2,4Zr0(I03)z,2ZrO(OH),,ZrO(I03),,3ZrO(OH),,ZrO(103)2, ZrO(C10,),,HC10,, Zr0(OH)2,9ZrO(C104),,and Zr0(OH)2,3ZrO(C103),.Following the method described in last year's Report for thepreparation of bismuth hydride, tin hydride has also been pre-pared.47 It is a gas that can be condensed by liquid air andvolatilised without decomposition.Some preliminary experimentsseem to show that lead hydride also can exist in the gaseous state.The following are described : ZrO(OH)2,2ZrO(IOa)2,Group V .Investigations have been made of the electrolysis of a solutionof ammonium azide in liqui'd ammonia a t - 6 7 O with anodes ofvarious metals.48 The evolved gases were measured, and the lossof weight of the anode determined. Proof was obtained of theformation of the following azides: CuN,, CuN,, AgN,, CdN,,PbN,, and SbN,.A deep red solution of ferric azide, FeN,, wasobtainea, but the compound was ammonolysed, and yielded anammono-basic ferric azide.The equilibrium between nitric oxide and bromine and theirreaction products has been studied between - 1 5 O and 330O. Withbromine a t pressures below 50 mm. and a t temperatures above140°, nitrosyl bromide is formed, the amount of the tribromidepresent being negligible.,, Independent evidence of the existenceof nitrosyl bromide and nitrosyl tribromide was obtained from thefusion-point diagram. The tribromide, NOBr,, is a brownish-black, almost opaque, liquid, which boils with partial decompositionat 32O.It has been found that red phosphorus acts as a reducing agenttowards many metallic salts in aqueous solution, and! very possiblythe method may prove of use in qualitative analysis.60 The solu-tion of the salt is boiled with 0.2 gram of red phosphorus for afew minutes.Mercuric and mercurous salts are reduced to themetal, gold and silver salts give insoluble phosphides, whilstpalladium and osmium salts yield either the metal or a phosphide.Stannic salts are partly reduced to stannous salts, ferric salts are46 F. P. Venable and I. W. Smithey, J . Arner. Chern. SOC., 1919, 41, 1722 ;4 7 F. Paneth and K. Fiirth, Ber., 1919, 52, [B], 2020 ; A., ii, 41.48 A. W. Browne, M. E. Holmes, and J. S. King, J . Amer. Chem. SOC.,4 s M. Trrcutz and V. P . Dalal, Zeitsck. anorg. Chem., 1920,110, 1 ; A., ii, 308.60 L.Rosenstein, J . Amer. Chem. SOC., 1920, 42, 883 ; A., ii, 428.A., ii, 43.1919,41, 1769 ; A., ii, 31IXORGANIC CHEMISTRY. 47reduced t o ferrous, iridic salts to iridous, selenates to the elementor a phosphide, molybdates to quadrivalent molybdenum salts,vanadates to tervalent vanadium salts, dichromates to chromicsalts, and permanganates to nianganous salts. Bismuth, lead,cadmium, antimony, and arsenic salts, arsenates, and stannous saltsare not reduced, whilst telluretes and platinichlorides are veryslowly reduced.When a few drops of phosphorus trichloride are added to anaqueous solution of alsenious oxide, the solution turns yellow, the11opaque-brown, and finally a copious precipitate of arsenic is throwndown.51 The reaction probably takes place in accordance withthe equation As,O, + 3PC1, + 9H20 = 2As + 3H,P04 + 9HC1.Thearsenic is amorphous, insoluble in carbon disulphide, and is appar-ently a new allotropic modification. The reaction takes place witharsenates and arsenites, and is very delicate, since the presence of0.000075 gram of arsenic per C.C. can be detected.Arsenic trichloride can very conveniently be prepared by passingcarbonyl chloride over a mixture of arsenious oxide (80 per cent.)and carbon (20 per cent.) heated a t 200° to 260'. The yield isalmost quantitative.52Golden antimony sulphide is usually supposed to be a mixture ofSb2S5, Sb,S,, and some free sulphur. The compound, Sb2S5, how-ever, is now shown not to exist, and the golden sulphide, afterextraction of the free sulphur, has the formula Sb2S4.Thissulphide can also be prepared in the following way.53 By theinteraction of Schlippe's salt and zinc chloride, zinc thioantimonateis precipitated. The crude salt contains free sulphur, and, afterremoval of this, the product has the formula Zn,Sb,S,. On treat-ment with dilute acid, an orange-red residue is obtained, which hasthe composition Sb,S,.By the oxidation of bismuth oxide or hydroxide in the presenceof alkali by chlorine, ammonium persulphate, or potassium ferriccyanide, the higher oxides of bismuth have been prepared.54 Thetetroxide was obtained as Bi,O, and Ei,O,,H,O, and of each ofthese there are two modifications, which are brown and purplish-black respectively.A third variety, Bi204,2H,0, which is yellow,has also been prepared. Bismuth pentoxide monohydrate,Bi,0,,H20, is obtained by the oxidation process, but is mixed withthe tetroxide. It can be prepared from sodium bismuthate by5L N. N. Sen, J . PTOC. Asiutic SOC. Bcngal, 1919, 15, 263 ; A . , ii, 308.52 L. H. Milligan, W. A. Baude, and H. G. Boyd, J . Ind. Eng. Chem.,53 F. Kirchhof, Zeitsch. anorg. Chem., 1920, 112, 67 ; A., ii, 693.54 R. R. Le G. Worsley and P. W. Robertson, Z'., 1920,117, 63.1920, 12, 221 ; A., ii, 37248 ANNUAL REPORTS ON THE PROGRES3 OF CHEMISTRY.repeated grinding with glacial acetic acid. The anhydrous oxidedoes not seem t o be capable of existence, as the monohydrate losesboth water and oxygen in a vacuum over phosphoric oxide.Bismuth hexoxide has also been prepared by the oxidation process,and is anhydrous.Group Vil.The solubility has been determined of sulphur dioxide insulphuric acid of various ~oncentrations.~5 Th6 measurements werecarried out a t 20°, and the acid concentration was varied from 55to 100 per cent.It was found that a sharp minimum solubilityoccurs with an acid containing 86 per cent. of H,SO,, and i t issignificant that the monohydrate, M,SO,,H,O, contains 84.5 perThe oxidation of ferrous chloride in presence of hydrochloricacid, and of ferrous phosphate in the presence of phosphoric acid,by sulphur dioxide has been studied.56 I n the first case, the reac-tion takes place in accordance with the equation4FeC1, + SO, + 4HC1= 4FeC1, + 214,O + S.The maximum amount of ferric iron produced was about 9 percent., and there seems little doubt that the reaction is reversible.I n the second case, more ferrous salt is oxidised, and the view isexpressed that the reaction4Fe(H2P8,), + 4€I,PO, + SO,= 4Fe(H,P0,)3 + 2H,O + Sis also reversible, but that it is modified by the formation of thestable complex formed by ferric phosphate and phosphoric acid.cent.of H,SO,.G’roup ??ill.A simple and rapid method has been described for the prepar-ation of iodine pentoxide, which depends on the oxidation of iodineto iodic acid by means of 24-26 per cent. chloric acid solution,the evaporation of the solution, and the dehydration of the iodicacid.57 The solution of chloric acid is prepared as iollows:625 grams of barium chlorate [90 per cent.Ba(C10,),] are dissolvedin 1 litre of nearly boiling water, and the solution is poured intoan earthenware crock. The required amount of hot sulphuric acid(obtained by mixing equal volumes of concentrated sulphuric acidand water) was slowly added. It is very necessary to have a slight55 F. D. Miles and J. Fenton, T., 1920, 117, 59.5 6 W. Wardlaw and I?. €3. Clews, ibid., 1093 ; W. Wardlaw, S. R. Carter,6 7 A. B. Lamb, W. C. Bray, and W. J. Geldard, J . Arner. Chem. SOC.,and F. €1. Clews, ibid., 1241.1920, 42, 1636 ; A., ii, 615INORGANIC CHEMISTRY. 49excess of barium chlorate rather than sulphuric acid, as the latterrenders the iodine pentoxide less stable. The solution of chloricacid may be kept unchanged in glass bottles for several weeks.Itis found that ‘in the presence of 3 per cent. excess of chloric acidthe net reaction with iodine is expressed by the equationI, + 2HC10, = 2EII0, -F C1,.The mechanism of the reaction, however, does not consist of thedirect replacement of chlorine by iodine. A considerable quantityof chloric acid is reduced to hydrochloric acid in accordance withthe eqmtion 312 -1- 5EIC10, + 3H20 = 6HIQ, 4- 5WC1. A solutioncon tainiiig hydrochlcric and iodic acids loses iodine on evaporationaccording t o the equation 21310, + lOHCl= I, + 5C12+ 6H,O. Thisis preveiiteci by an excess of chloric acid, which reacts with thehydrochloric acid, and i t was found that an excess of 3 per cent.is sufficient.The iodine is cxidised in quantities of 500 grams, the reactionbeing finished in about twenty miizutes.The iodic acid obtained011 evapcratioii is heated a t 150--lGO0 for three hours. The finddehydration is carried out a t 235-240° in a slow current of dryair. The iodine pentoxide is pure white, and has practically thetheoretical oxidising value, and the yield is almost quantitative.The process has many advantages over the nitric acid method.With reference to this preparation of iodic acid, it is interestingt o note that iodine replaces bromine when the former acts on anaqueous solution of potassium bromate, and that a similar reactiondoes not occur with bromine and potassium chlorate, whilst thereaction between iodine and potassium chlorate is more coniplex.s*The following changes have been shown t o occur:and KHI,O, + KC1 + HC10 = 2KI0, + H,O + Cl,.Potassium maiiganifluoride, Ii2MnF,,LI,0, has been prepared bythe action of nitrous acid 011 potassium permanganate in thepresence of hydrofluoric acid .59 The permanganate is reduced bythe nitrous acid.A manganous salt may also be used, in whichcase the nitrous acid acts as an oxidising agent.ZMClO,-+ 21 + MZO = KHI20, + KC1 + HC10Group V I I IIt has been found that the yield of sodium ferrate obtained bythe electrolysis of sodium hydroxide solution with iron anodes isvery materially increased by superposing an alternating current5 8 G. Gruber, Zeitsch. physikal. Chern. Uszterr., 1920, 33, 107 ; A., ii, 684.69 I.Bellucci, Gaxzetta, 1919, 49, ii, 180 ; A., ii, 4050 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.on the direct current.g0 I n one case the increase of yield was 160per cent. I f the anode and cathode are separated, and thetemperature of the electrolyte is not allowed to exceed 50°, a twhich the ferrates decompose, and an alternating current is super-imposed on the direct current, saturated solutions of sodium ferrateand the crystalline salt can be obtained.Some further work has been carried out on the influence ofhydrogen sulphide on the occlusion of hydrogen by palladium .61The earlier experiments were discussed a t some length in theReport for last year. I n the earlier paper it was shown that whenpalladium is poisoned by hydrogen sulphide, and then heated a tlooo in a vacuum, an amount of hydrogen is evolved equal involume to that of the hydrogen sulphide previously absorbed inthe poisoning.The sulphur is retained by the palladium, a com-plex of the formula Pd,& being formed. Dr. Maxted believes thatpalladium can dissociate hydrogen sulphide to form this complexand free hydrogen slowly a t ordinary temperatures. When thistakes place, more hydrogen is slowly occluded, and the total volumeso occluded added t o the volume derived from the hydrogensulphide is equal to the true occlusive power of palladium forhydrogen, allowing for the palladium which has formed the Pd,Scomplex. This explanation is based on the observation that asample of palladium which has been completely poisoned byhydrogen sulphide slowly gains a power of absorbing hydrogen upto a fixed amount, and that the rate of absorption is faster thelonger the poisoned palladium is kept before the hydrogen isadmitted.This interpretation may be criticised from two points of view.I n the first place, since the palladium dissociates hydrogen sulphide,i t is probable that this dissociation occurs a t the time of occlusion,and that it is, indeed, the basis of the occlusion.I n the secondplace, if palladium is absolutely completely poisoned by hydrogensulphide, it should not gain, on keeping for an unlimited time, anypower of occluding hydrogen. Dr. Maxted offers no explanationof his view that the occlusive power for hydrogen should beincreased when the hydrogen sulphide is dissociated. True poison-ing must mean the absorption of hydrogen sulphide up t o thepoint when a portion of the palladium is converted into the com-plex Pd,S, and the remainder is saturated with the hydrogenobtained by the dissociation of the hydrogen sulphide. Obviously,when this has been secured, no further hydrogen can be occluded.It would seem far more probable that the poisoning obtained with6o a. Grube and H. Gmelin, Zeitsch. Elektrochem., 1920, 26, 153; A .ii, 377. 61 E. B, Maxted, T., 1920, 117, 1280INORGANIC CHEMISTRY. 51hydrogen aulphide is not complete in the strict sense, but that thepoisoning is concentrated on the surface. On allowing the partlypoisoned palladium to remain, a more equal distribution of thehydrogen takes place, with the result that more hydrogen can beoccluded. This is shown by the fact that, even after the palladiumhas been (‘ completely ” poisoned by hydrogen sulphide, it stillpossesses the power of slowly absorbing more hydrogen sulphide.The data are still too incomplete for accurate calculations of thetrue equilibrium conditions. It appears that 1 gram of palladiumhas the definite power of absorbing 69 C.C. of hydrogen. I s thewhole of thii hydrogen dissociated into atoms, or are there twoprocesses, first the occlusion of hydrogen as atoms, followed by asecondary effect of condensation as hydrogen molecules ? Thesecond alternative seems the more probable, but the question canonly be decided by accurate measurements of the dissociationpressures of hydrogenised palladium.An investigation has been made of the hydrolysis of aqueoussolutions of potassium platinichloride.62 It is shown that N / 50and more concentrated solutions are slowly and completely hydro-lysed in the dark, whilst #/lo0 and more dilute solutions undergohydrolysis only when exposed to light. It is found that the hydro-lysis takes place a t first very slowly, but after a time the rateincreases, and this is attributed to the formation of some substancewhich acts as a catalyst. This view was supported by the factthat the addition of a portion of a photochemically hydrolysedsolution to a fresh, N / 100-solution of platinichloride causes thelatter t o undergo hydrolysis in the dark.The addition of a soluble chloride to the hydrolysed solutioncauses a complete reversal of the reaction, and this reverse reactionis influenced by light in much the same way as is the direct reac-tion. The influence of platinum-black in accelerating both thedirect and reverse reactions in the dark is quite noticeable, but isnot measurable when light is acting on the solutions.E. C. C.‘BALY.62 E. H. Archibald, T., 1920, 117, 1104

ISSN:0365-6217    

DOI:10.1039/AR9201700027

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART ALIPHATIC DIVISION.A SURVEY of the literature shows that few laboratories have yetbeen able to devote much of their energies to systematic researchon the pre-war scale. The present Report deals only with suchpapers as the writer considers of importance from the theoreticalpoint of view or for new methods of preparation. A distinctivefeature of this year's literature is the number of papers dealingwith the compounds used so extensively in chemical warfare, andwith alternative methods for the synthesis of substances of whichthere was a scarcity in the belligerent countries,Hydrocarbons.Very few investigat'ions on hydrocarbons have been describedduring the year, but i t is of interest to gauge the success attend-ing the strenuous efforts made in Mid-Europe t o use paraffin for theproduction of i'atty acids and their esters to overconie the shortageof natural fats.The usual method was to heat the hydrocarbons ofhigh molecular weight with oxygen or air, generally under pressurein the presence of a catalyst. Thus, in the presence of manganesecompounds, C. Kelherl converted a paraffin wax (m. p. 50°), byt8he action a t 150° of a stream of finely divided oxygen, into amass of which more than 35 per cent. consisted of fatty acids in-soluble in water, and about 25 per cent. of the lower (up to Clo)fatty acids.€1. R. Franck2 used also up to 5 per cent. of various compoundsof lead, mercury, vanadium, and chromium, and, working a t 150°in an autoclave filled with oxygen, obtained from paraffin of lowermelting point 40 per cent.of fatty acids of higher, and 57 percent. of acids of lower, molecular weight. A mixture of the acidsso obtained was esterified with ethylene glycol, and yielded anedible fat said to resemble coconut oil. A variation is describedBer., 1920, 53, [B], 66, 1567 ; A., i, 280.Chom. Zeit., 1920, 44, 309 ; A., i, 417.5ORGANIC CHEMlSTRY. 53by F. Fischer and W. Schneider,3 who worked in a steel autoclavea t 170° in the presence of sodium carbonate, the mixture beingstirred by pumping in compressed air. These authors obtaineda 90 per cent. yield of fatty acids from crude paraffin, and are ofthe opinion that iron, copper, and manganese have equal catalyticeffects. A. Grun4 has studied these reactions more in detail, andshown that the results are dependent on man7 factors as yet littleunderstood.I n the absence of water the anhydrides of the higherfatty acids are formed, and in every case the iieutral products con-tain ketones, such as stearone. The acids formed all appear t ohave a “ straight-chain ” structure, whilst, according to Fischerand Schneider, the acids containing an uneven number of carbonatoms are formed iiz greater quantity than those with an evennumber, which are commonly derived from natural fats.The list of compounds formed in the pyrogmic condensation ofacetylene has been considerably increased 5 by the crystallisationof the picrates of the higher boiling fractions of the tar. It hasbeen shown that acetylene condenses a t 100-200° with methanein the presence of metallic catalysts, giving a 70 per cent.yield ofpropylene ; at higher temperatures (200-350°), non-metalliccatalysts, such as thoria and silica, give similar results7 even witha t least the lower homologues of both acetylene and methane.The importance of a study of the mercury compounds of acetyl-ene was emphasised in last year’s Report, and attention shouldbe drawn to the theoretical discussion by W. Manchot and A.Kliigs of those of ethylene and of carboa monoxide. A detailedstudy of the conversion of acetylene into acetaldehyde and intoacetic acid in the presence of mercury catalysts is described by B.Neumann and H. Schneider.9 The best yield (90 per cent.) ofacetaldehyde was obtained when the gas was led with vigorousmechanical stirring into a catalyst composed of 96 per cent. aceticacid, containing 3 per cent.of mercuric sulphate, the temperaturebeing maintained a t about 30°. The best results (83 per cent.yield) in the direct conversion of acetylene into acetic acid wereobtained by using the same catalyst, with the addition of vana-dium pentoxide, acetylene and oxygen being led in alternately.Ber., 1920, 53, [B], 922; A., i, 519.R. Meyer and K. Taeger, ibid., 1261 ; A., i, 589.A. Heinemann, D.R.-P. 315747 ; A., i, 281.Chemische Fabrik Buckau, D.R.-P. 294794 ; A., i, 657.Ibi?., 987 ; R . , i, 518.8 Annalen, 1920, 420, 170; A., i, 720; also Ber., 1920, 53, [B], 984; A.,Zeitsch. angew. Chem., 1920, 33, 189; A., i, 657.i, 51954 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.Alcohols and their Derivatives.In the catalytic reduction of acetaldehyde by hydrogen, theproduction of ethyl alcohol falls off gradually with the formationof ethyl ether as a by-product, whilst the catalyst is poisoned bydecomposition products of acetaldehyde.These undesirable re-sults are avoided10 by the use of an excess of hydrogen containingabout 0.2 per cent. of oxygen, and when working between 90" and170°, a t which temperature acetaldehyde begins to decompose, ayield of 95 per cent. of alcohol can be obtained. The beneficialeffect of the oxygen cannot, however, be wholly attributed to theoxidation of carbon monoxide or other impurities, to the presenceof which the injurious effect on the catalyst has been ascribed.If hydrogen quite free from oxygen be used (and it is stated thatelectrolytic hydrogen invariably contains some oxygen), a mixtureof alcohol and ether is produced.The formation of ether com-mences a t about 90°, and in the process up to 15 per cent. isobtained.The formation of acetone by the fermentation of starch isdependent as a commercial process on tho utilisation of the n-butylalcohol, of which a t least two parts are produced for every one ofacetone.ll I n this connexion the transformation of the alcohol intomethyl ethyl ketone is promising,l2 as the various reactions pro-ceed quite smoothly. These are: The catalytic dehydration of thealcohol by glacial phosphoric acid a t about 350°, the absorptionof the P-butylene (freed from y-butylene by scrubbing with 60per cent.sulphuric acid) in concentrated sulphuric acid, f orma-tion of see.-butyl alcohol by the action of water on the butylhydrogen sulphate thus produced, and the catalytic dehydrogenationby copper of the see.-butyl alcohol by the Sabatier and Senderensprocess. The use of n-butyl alcohol as a starting material forvarious synthetical reactions, such as the preparations of n-amylalcohol, n-valeric and n-hexoic acids, has been studied by R. Adamsand C. S. Marvel.13 The writer can recommend their methods,which give very good yields and are well adapted for students'exercises in place of some of the preparations usually set.Further condensations of m-butyl alcohol with the correspondingaldehyde,l4 and of n-butyl chloroformate 15 with alcohols andlo Elektrizitiitswerk Lonza, Brit.Pat. 134521 ; D.R.-P. 317589 ; A., i, 134.l1 J. Reilly, W. J. Hickinbottom, F. R. Henley, and A. C. Thaysen, Biochem.J., 1920, 14, 229; A., i, 466. 13 A. T. King, T., 1919, 115, 1404.J . Amer. Chem. SOC., 1920, 42, 310; A., i, 283.l4 C. Weizmann and S. F. Canard, T., 1920,117, 324.l5 F. D. Chatfaway and E. Saerens, ibid., 708ORGANIC CHEMISTRY. 5 5amines, according to well-known reactions have also been described.A. Mailhe and F. de Godonl6 have continued their studies of thecatalytic preparation of ethers in the dry way, and recommendaluminium oxide (prepared by heating commercial ammoniumalum a t 190°) as a catalyst.This method gives about 70 per cent.of diethyl ether from 96 per cent. alcohol, and is suitable for thepreparation of simple and mixed aliphatic ethers containing normalgroups, but fails with isopropyl and 'isobutyl alcohols, and givesonly a 30 per cent. of the corresponding ether from ally1 alcohol.The catalytic effect of mineral acids in esterification is attributedto their linking the alcohol and organic acid in a molecular com-plex, where opportunity is afforded for an interchange of radicles.While investigating this, 0. Maass and J. Russell17 have provedthe existence of an oxonium compound, (C,H,),0,HBr,H20, butcould not obtain definite evidence of a compound of ether, hydro-gen bromide, and ethyl alcohol: Very similar suggestions aremade by 0.Aschan,l8 who explains the catalytic effect of etherin aiding the addition of hydrogen chloride and of sulphuric acidto unsaturated compounds as due to the intermediate formationof diethyloxonium salts. He shows that the mixing of ether andsulphuric acid monohydrate causes a large development of heat,and gives a mixture more viscous than the sulphuric acid, but hewas unable to isolate the diethyloxonium sulphate or any of itssalts.Lowry and co-workers 19 describe experiments t o recover theoxidised nitrogen in cordite in the form of calcium nitrate. Theyconsider that hydrolysis of the normal type is not the pre-dominant action when cordite is decomposed by lime in the presenceof pyridine. The calcium salt of hydroxypyruvic acid is an im-portant product of the reaction, and these authors suggest thatthe main action is a decomposition of the nitric ester into a ketoneor aldehyde and a nitrite.R. C. Farmer,20 however, from a reviewof their work and that of the numerous previous workers a t thisproblem, and from some fresh experimental data on the decomposi-tion and hydrolysis of glyceryl nitrates, disagrees with their con-clusions and, tracing the various stages of the different forms ofdecomposition of nitric esters, maintains that the first stage insuch is a true ester hydrolysis of the normal type.Bull. SOC. chim., 1919, [iv], 25, 565; 1920, [iv], 27, 121, 328 ; A . , i,6, 284, 470.l7 Trans. Roy. SOC. Canada, 1919, 13, [iii], 259 ; A., i, 621.18 T. M. Lowry, K.C. Browning, and J. W. Farmery, T., 1920,117, 662.Medd. K . Vetenskapsakad. Nobel-Inst., 1919, 5, No. 8 ; A., i, 136.Ibid., 80656 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Aldehydes u n d Ketones.The oxidation of methyl alcohol to formaldehyde has been in-vestigated by many workers in the past, but the latest contribu-tion to the subject is valuable. I n this, M. D. Thomas21compares the relative aatalytic effect on the oxidation underdifferent conditions of silver, gold, and copper. Of these,silver has the best effect, and by its use a yield of morethan 55 per cent. was obtained in the process. Finely dividedsilver,22 preferably deposited on asbestos, is recommended also f o~the catalytic oxidation by air a t about 25Qo of primary andsecondary alcohols to the corresponding aldehydes and ketones.The action tends t o become very intense owing to rise of tempera-ture of the catalyst, but if care be taken t,o regulate this, the methodcan be employed generally with success even with unsaturatedalcohols.A new and in some cases a very useful method of preparingaldehydes is patented by C.Harries,23 who shows that ozonides canbe reduced preferably by f errocyanides to aldehydes, nonaldelzyde,for example, being formed by the reduction of the ozonide of oleicacid.The great diversity in the type of compounds which acetylacetoneforms with metals, metalloids, and non-metals has now beenextended by the discovery of a new type in the selenium andtellurium acetylacetonates, which are described in a papel 24 bear-ing on the complex questioiis of residual aznity and co-ordination.An attempt25 to use the additive compounds of the acetyl-acetonates of the metals of the rare earths with ammonia andamines as a convenient means of separating these elements was,however, quite unsuccessful.Acids and t h e i r Derivatives.Very little work in this sectioii has been published during theyear.The details26 of a much improved method of preparinggluconic acid 011 a technical scale suggest that this may be utilisedas a substitute for soine of the more expensive vegetable acids.21 J . Amer. Chem. SOC., 1920, 42, 867 ; A., i, 473.22 C. Xoureu and C. Mignonac, Cornpt. rend., 1920, 178, 258 : A., i, 283.33 D.R.-P. 321567 ; A., i, 675.24 G.T. Morgan and H. D. K. Drew, T., 1920, 117, 1456.25 G. Jantsch and E. Meyer, Ber., 1920, 53, [B], 1577 ; A., I. 711.26 A. Herzfcld and G. Lenart, Zeitsch. Ver. deut. Zuckerind., 1919, 122 ;A . , i, 143ORGANIC CHEMISTRY. 57The well-known work of K. Meyer and co-workers on the keto-enolic desmotropy of the esters of P-ketonic acids has been ex-tended 27 to an examination of the effect of fractional distillationon ethyl acetoacetate. By the use of Jena-glass apparatus, whichhad been steamed and washed with alcoholic hydrogen chloride,it has been found possible to isolate the less volatile ketonic formby distillation under a pressure of 2 inni. The proportion of enoito ketone is unaffected by distillation, for the actual amounts ofthe two forms in the original ester before distillation in a quartzvessel and in three fractions and a residue, all of equal volume,were practically the same, whilst the residue was free fi-om theenolic form.The method obviously affords the easiest JTle&i?S ofpreparing the pure ketonic ester, and by repeated distillation oflarge amounts of the ester might yield the pure enolic form.Similar results are recorded for the distillation of methylbenzoylacetate, although the fractionation proceeds more slowly,but with this ester a small first fraction solidified to give thepure enolic form. For many years i t has been the practice topostulate the existence of enolic forms of aliphatic esters to explaincertain reactions. R. Scheibler and 3. Voss28 have showir thatthe potassio-derivatives of eSters, which contain a t least onehydrogen atom attached t o the carbon atom in the a-position withrespect to the carbalkyloxy-group, are readily obtained as colouredamorphous substances when an ethereal solution of the ester isadded to the finely divided metal, which is covered with etherheated to gentle ebullition ; under these conditions the metalc'lissolves i-inmediately with evolution of hydrogen, whilst the metallicderivative remains more or less completely in colloidal solution inether.Sodium acts less energetically, and the corresponding deriv-atives are often only formed at temperatures at, which they arepartly decomposed. These ester-enolates are very nnstable sub-stances, which can, however, be preserved for some time under etherin an atniosphere of hydrogen or nitrogen.They are immediatelydecomposed on the addition of water with the regeneration of theesters, but react with carbon dioxide, giving colourless potassiumsalts of carboxylic acids, which are stable towards oxygen andwater, but contain the carboxylic group in a very loose state ofcembinatJ;ozr. So far not much evidence has been brought forwardto prove the fo~nrulz ascribed to these compounds, but the reactionbetween ethyl chloroformat3 and ethyl potassio-acetate can be tlosome extent explained on the basis of the formula CR,:C(OK)*OEt.Many difficulties are met with when attempts are made to syn-27 K. H. Meyer and V. Schoeller, Bey.: 1920, 53, rB], 1410 ; A ., i, 707.8 8 Ibid., 388: A . , i, 36658 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.thesise the natural fats. Up to the present the general methods forthe preparation of mono- and di-glycerides have depended eitheron the action of glyceryl chlorohydrins on the salts of fatty acidsor on esterification of the fatty acid with the chlorohydrin, andthe subsequent exchange of the halogen atoms for the hydroxylgroup. Now the glyceryl monochlorohydrins 29 are difficult toprepare in a state of purity, and are not adapted for such syn-thetical reactions, as these methods are complicated by side-reac-tions. There is, further, no guarantee of the simple replacement ofthe halogen by the acyl radicle, whilst, in fact, several instances ofthe wandering of such acyl groups are now known.30 A new method,which will yield a-monoglycerides of undoubted purity, is pub-lished31 under the names of Emil Fischer and co-workers.Asinitial material ‘‘ acetone glycerol ” is used, and the constitutionof this has been shown by Irvine, Macdonald, and Soutar32 to beisopropylideneglycerol, CMe2<0.!,H~CB,.0H. O*CH This compoundreacts readily in the presence of quinoline with acid chlorides, yield-ing products from which the acetone residue is easily removed bydilute acids a t about 50°, thus giving undoubted a-monoglycerides.The results of this important work throw great suspicion on thepurity of the monoglycerides previously described, whilst it maybe expected that the method, even without the guiding hand ofFischer, will lead to further knowledge of the chemistry of fats.B a I ogen Corn pounds.One of the less pleasant features of the literature this year isthe large amount of space which has been devoted to descriptionsof various halogen compounds used so extensively in chemical war-fare. The preparation and properties of PP’-dichlorodiethyl sul-phide have been detailed in the chemical journals of five countries,in the allied countries it having been made very simply by theaction33 of sulphur monochloride on ethylene at about 60°, whilstin Germany the more complicated synthetic process throughethylene chlorohydrin and P@-dihydroxydiethyl sulphide was usedas described by Victor Meyer in 1886.Several chemists haveused the highly reactive dichlorosulphide for various syntheticalas L.Smith and E. Samuelson, Zeitsch. physikal. Chfm., 1920, 94, 691 ;A., i, 658.E. Fischer, Ber., 1920, 53, [B], 16.21 ; A., i, 808.*l E. Fischer, M. Bergmann, and H. Barwind, ibid., 1589 ; A . , i, 505.32 T., 1915,107, 337.33 (Sir) W. J. Pope, C. S. Gibson, and H. F. Th1aillior, Brit. Pat. 142876 ;A., j, 523ORGANIC CHEMISTRY. 59experiments, of which perhaps the most complete account is thatby 0. B. Helfrich and E. E. Reid.34French chemists35 have made very detailed studies of thenumerous compounds produced by the substitution of hydrogen bychlorine in methyl formate and carbonate; i t may be expected thatsome of these will be of considerable use in synthetical work.A very convenient modification of the older methods of prepar-ing alkyl bromides is described by 0.Kamm and C. S.I n this a solution of hydrobromic acid is first prepared by the re-duction of bromine by sulphur dioxide in the presence of water.Concentrated sulphuric acid is then added, and the mixture heatedunder a reflux with the alcohol to be brominated. The method'can be recommended, as i t gives good yields with very little trouble.c&Dichlorovinyl ethyl ether is readily prepared from the com-mercial trichloroethylene by the action of sodium ethoxide, andhas been found useful in the synthesis of chloroacetates and acidchlorides.37Numerous new per-iodides of carbonyl compounds 38 and esters 39have been described, and it is remarkable that those prepared fromdiethyl oxalate of the type (C202Et,),,NaI,I, were obtained in thepresence of water.These compounds are apparently oxoniumderivatives, and will require consideration from those studyingresidual valency.Optical Activity.It has been well known in a few cases that the taste of someoptically active compounds is different from that of their opticalantipodes. This very difficult field of research has not receivedmuch attention, and an interesting paper40 on the relative sweet-ness of some compounds of a-hydroxyisohexoic or " leucic " acid isall the more welcome. It is a common practice in Japan to usecertain amino-acids, such as d-glutamic acid and its salts, as taste-producing substances iii food, and the author, by replacing theamino-group in some of these by hydroxyl, has obtained some verysweet substances.Thus, by suitable treatment, leucine has beenconverted into the corresponding hydroxy-acid. The sodium,ammonium, potassium, and calcium salts are very sweet, the sodiuma4 J . Amer. Ghern. Soc., 1920, 42, 1208; A., i, 524.35 Inter alia, V. Grignard, G. Rivat, and E. Urbain, Compt. rend., 1919,38 J . Arne?'. Chem. SOC., 1920, 42, 299; A., i, 282.87 H. Crompton and (Miss) P. L. Vanderstichele, T., 1920, 117, 564.39 A. Skrabd and E. Flach, Monahh., 1919,40, 431 ; A., i, 527.' 0 S . Kodams, J . Tokm Ohem. SOC., 1919, 40, 825 ; A., i, 471.169, 1143 : A., i, 138.A. M. Clover, J . Amer. Chem SOC., 1920, 42, 1248; A., i, 52860 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.salt being about ten times as sweet as sucrose.The taste is appar-ently due to the a-hydroxyisohexoic ion, since all the salts andthe acid itself in dilute solution are sweet, whilst the solid acidand its ester are not. It is remarkable that the two anhydridesC,H,*CH( OH)*CO*O*CB (GO&) *C,H, are bitter, but become sweetwhen boiled with dilute alkalis. The acetyl and alkyl derivativesof the leucic acid are not sweet, and their salts are tasteless, but asalt of acetyl-leucic acid when boiled with water slowly becomessweet, owing to the elimination of the acetyl group. The sweetnessof d-glutamic acid is twice as great as that of the dl-acid, and thesweetness of a sale of leucic acid depends on the amount of thedextrorotatory form which is present.Thus, having obtained bya Walden inversion a dextrorotatory leucic acid from the corre-sponding Z-acid, the author shows that the salts of the d-acid aresweeter than those of the &-acid, wliich are also sweeter than thoseof the Z-acid.Some years ago Hudson suggested that the difference betweenthe molecular rotations of the a- and P-forms of mutarotatorysugars is a constant, and afterwards extended these views41 to thephenylhydrazides of certain acids of the sugar group. Hesucceeded in showing that in acids containing u-, P-, y-, and8-asymmetric carbon atoms, the rotation due to the u-carbon atomwas very much larger than the values due to the other threecarbon atoms added together, and so the direction of the rotationof the phenylhydrazide could be used as an indication of the con-figuration of the laydroxyl group attached to the a-atom. Hisresults have now received valuable confirmation from the extendediiavestigation of Mlle.T. W. J. van Marle,42 who, working withgluconic, mannonic, galactonic, gulonic, idonic, isosaccharic,arabonic, ribonic, xylonic, and lyxoiiic acids, has been able to provethat Hudson’s conclusions hold equally in aqueous solution for thehydrazides, y-bromophenylhydrazides, o-, rn-, and p-tolylhydr-azides, the amides, anilides, and o-, m-, and p-toluidides. It isnot surprising, however, that conflicting results were obtainedwhen the rotations o l these compounds were examined in pyridinesolution, and in the opinion of the writer it seems a great pity, inview of the results obtained in recent years in the domain ofoptical activity, that the material prepared with so much troublefor this research was not examined with monochromatic light ofmore than one wave-length.J.Amer. Chem, LYOC.. 1917, 39, 462 ; A., 1917, i, 318.12 Rec. trao. chim., 1920, 39, 549 ; A., i, 592ORGANIC CHEMISTRY. 61The hydrolysis of the esters of certain optically active hydroxy-acids has yielded in the past very perplexing results, ar,d asummary 43 of the behaviour on hydrolysis G f the optically activeinenthyl and bornyl esters of the various isomeric ‘‘ phenyl-lactic ”and other acids is welcome.are racemised readily, and their esters are catalytically racemisedby warming with an amount of alcoholic solutions of sodium orpotassium hydroxide insuficient to complete the hydrolysis ; on theother hand, the acids G,T-I,*CW2*CH(OI-I)*@0,H,and C~H5*CMe(OH)*C02~, and their esters, are far less prone toracemisation. Thus it appears that although compounds of thetype R*CH(OEI)*CO,R’ present a system prone to rzcemisation invirtue of the mobile hydrogen atom being in the a-position, thiscircumstance is not in itself a factor in promoting racernisationunless R is an aromatic residue attached directly t o the asymmetricatom.I n the event of R being an aliphatic group? it may beargued that this system would probably be stable, so far as race-inisation by alkali is concerned, and this is coniirmed t o someextent by experiments with lactic acid.C.Neuberg and F. F. Nod4* have investigated the phyt’o-chemical reduction of unsymmetrical ketones. These, added t osucrose undergoing fermentation by yeast, are partly reduced tosecondary alcohols. The hydrogenation does not proceed a t allreadily, but the diastereoisomerides are formed a t different rates,so that the products, whilst not optically pure, have a considerableactivity, which is much greater than observed by Le Be1 in hisclassical experiments on the preferential deconiposition by mouldsof the diastereoisomerides of secondary alcohols. They claim alsoto prepare a lzevorotatory By-butylene glycol by the hydrogenationof diacetyl by similar means, a result which is all the more remark-able as previous investigators have found that the production ofthe glycol from carbohydrates by bacterial agency leads only tothe racemic or meso-forms.An interesting attempt45 has been made t o summarise thephenomena observed among the optically active substances foundin the animal and plant kingdoms.Whilst there are severalexceptions, it would appear that, in general, the normal productsof animal metabolism occur in optically active forms, but in thecase of the plant organism, on the other hand, the diastereo-43 A. McKenzie and H. Wren, T., 1920, 117, 680.44 Ber., 1919, 52, [B], 2237, 2238 ; A., i, 135.46 K. Hess and W. Welt.zien, ibid., 1920, 53, [B], 119 ; A., i, 328.Mandelic acid and tropic acid,CGH,*CH( CH,*OH)*CO,H,C,PI,* CN (0 H ) * CM2*C0,3FrP62 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.isomerides are not infrequently formed in equal amounts.It isprobable, however, that the specific action of an enzyme is onlyconditional, and that whilst a ferment appears to attack preferenti-ally one modification of a given compound, it can, in case ofnecessity, attack the antipode, or it may be that whilst undernormal conditions the rate of reaction between an enzyme and thetwo diastereoisomerides is different, when the conditions are suit-able the rate becomes identical. The production of opticallyinactive bases containing an asymmetric carbon atom may beascribed, however, to other causes. Thus, racemisation of aprimarily formed optically active alkaloid may have occurredduring the treatment of the dead plant with extracting solvents,or it may have occurred within the plant during its life, or, again,the formation of the alkaloid in the living plant may have beenbrought about by ordinary symmetrical forces in which enzymeshave no part. It is well known, however, that alkaloids vary verygreatly in their resistance to racemising reagents ; thus hyoscyamineis readily converted by alkalis into atropine, and pelletierine andallied substances are less prone to racemisation in this way, whilstconiine and d-methylconiine are unchanged by drastic treatmentwith acids or alkalis.E.Erlenmeyer *6 has described the formation of optically activecinnamic acids. It is suggested that the activation of the cinnamicacid is brought about by the “ induction” influence of other optic-ally active components involved in the reactions.Thus when anoptically active phenylbromolactic acid is reduced with zinc in hotalcoholic solution, one half of it passes into phenyl-P-lactic acidand the other half into cinnamic acid, which has a rotation of thesame sign as that of the bromc-acid. The activity of the resultingcinnamic acid is not due to contamination with phenyl-lactic acid,as repeated extractions with water still leave an active cinnamicacid, and this is further confirmed by comparative experimentswith actual mixtures of optically inactive cinnamic acid and8 activephenyl-lactic acid. I n a similar manner, a laevorotatory dibromideof cinnamic acid is formed by the action of bromine on a mixtureof the zinc salts of cinnamic and d-phenyl-lactic acid, an oppositeresult being obtained when Z-phenyl-lactic acid was used.Thereduction products of Z- and of d-phenylbromolactic acids in thesame way yieId dibromides of cinnamic acid with rotations oppositein sign to that of the bromo-acids employed. Further experi-mental results obtained are : cinnamic acid “ activated ” under theinfluence of Z-mandelic or Z-chlorosuccinic acid becomes dextro-rotatory and yields a laworotatory dibromide, whilst with &tartaric48 Biochem. Zeitsch., 1919, 97, 198 ; A., i, 45ORGANIU CHEMISTRY. 63acid or with d-cinchonine, a lzevorotatory acid and dextrorotatorydibromide are formed.As the geometrical isomeric formula of cinnamic acid with thedouble bond cannot account for the active cinnamic acids, theauthor suggests a stereoisomeric structure with free unsaturatedaffinities, thus :andHRecent work by Lowry and others has stimulated a re-examin-ation of the menthyl esters of certain keto-acids describedpreviously by Rupe47 and his co-workers.The rotations of thesewere observed1 only for sodium light, but light of other wave-lengths has now been used. Most of these substances are not,however, homogeneous, containing varying proportions of the enolicand ketonic forms, according to the conditions. However, theauthors “ re-discover ” the applicability of a one-term Drudeequation, U = ~ / A ~ - A ~ ~ , as has been shown by Lowry and otherinvestigators, t o the optical dispersion of a great number of com-pounds.They adopt the following classification of abnormalrotatory dispersion: (i) total anomaly of a mixture of two sub-stances with opposed activities (Tschugaev’s extramolecularanomalous dispersion) ; (ii) total anomaly of a compound contain-ing two different asymmetric complexes, one of which is dextro-,the other laevo-rotatory (Tschugaev’s intramolecular anomalousdispersion) ; (iii) when the rotatory dispersion curve does not passthrough a maximum or minimum, neither does it approximate toa horizontal line, but A and h02 ,differ widely from the normalvalues and - A2 gives bent or zigzag lines (complex rotatory dis-persion of Lowry); (iv) apparently normal course of the curves Yand - A2 gives straight lines, but A, and kO2 differ greatly (at least 7 -t15 ,up for the former) from the normal value for the particularclass of compound (relative anomaly).47 H.Rupe and H. Kiigi, An,nalen, 1920, 420, 33 ; A., i, 74864 ANNUAL REPORTS ON THE PROGRESS 0%’ CHBMISTRY.The paper contains a criticism of the proposal by Lowry a i dAbram 48 to delete the “ relatively abnormal ” classification ; theauthors consider that suEcient substances are known, in whichA, differs by 15-6Qpp and lo2 by as much as five units from thenormal figures for the class of substance without, however, exhibit-ing cGmplex anomaly, to justify a separate classification.It may be pointed out, however, that many substances haverotations which are numerically low, whilst the accuracy of thedetermination of rotatory power is n o t very great, so that in theopinion of the writer i t is unwise in the present state of knowledgeto adopt the more elaborate classification set out by Rupe.Car bohydrntes and their Deriuatitles.I n 1913 Emil Fischer49 obtained a strongly reducing compound,C,H,,O,, which he named glucal, by the reduction of @-acetobronio-glucose , with zinc dust and acetic acid.It is a slightly sweet,soluble, viscid syrup with aldehydic properties, and evidentlypossesses ethylenic unsaturation, since i t decolorises bromine water.When hydrogenated in the presence of palladium, hydroglucal isformed, and this contains no double bond; the same product isformed if the acetate of glucal is similarly hydrogenated and thenhydrolysed. The constitution of giucal has not been conclusivelyproved, but the latest paper5O shows that its properties are satis-f actorily explained by the formula0 H= CH,* C H ( 0 H ) C H C H (0 13) - CH : CX3.1- 0- ~ - 1New reactions pointing to this formula are: ( a ) the additive pro-duct of glucal and bromine, when treated with silver acetate, yieldsa stereoisomeric mixture of tetra-acetylglucose-P-bromohydrins,OAc*CH,*CH(OAc)-CH*CH(OAc)*CHBr*CH*OAc, which, afterdeacetylation with dilute hydrochloric acid, gives with phenyl-hydrazine an over-all yield of 60 per cent.of d-glucosephenyl-osazone; ( b ) glucal triacetate is transformed by ozone in glacialacetic acid solution into the triacetyl derivatives of d-arabinoseand an acid, which is probably arabonic acid; (c) the colour reac-tion with pine shavings; ( d ) the proof of the presence of only threehydroxyl groups in hydroglucal. These show that glucal containsthe normal carbon chain present in dextrose, that the double bondI 0 !48 T., 1919, 115, 300.p9 Sitzungsber.K . Akad. Wisa. Berlin, 1913, 311 : A., 1913, i, 445.6o E. Fischer, M. Bergmann, and H. Schotte, Ber., 1920, 53, [B], 509 ; A.,i, 420ORGANIC CHEMISTRY. 65is between the first and second carbon atoms, and that it is relatedto furan, whilst the presence of a butylene-oxide formation inhydroglucal is suggested by its stability towards hydrochloric acid,which renders an ethylene- or propylene-oxide structure mostimprobable.The structural formula for sucrose which is now considered themost likely is that put forward by \V.N. Haworth and Law in1916, in which this sugar is repcesented as formed by the fusionof a-glucose having the butylene-oxide structure, and of a-f ructosehaving the ethylene-oxide structure :OH*CH,*CH (OII)*CH*[CH *OH] ,*CH-O d-CH*[CH(OH)],*CH,*OH.CH,*OH‘4 I 0- IWhen sucrose is hydrolysed in the presence of acids, these formsare the first to be produced, but subsequently they rapidly undergoisomeric changes, giving successively the corresponding butylene-oxide form of fructose and then an equilibrium mixture of thea- and @-modifications of this, whilst alongside the P-butylene-oxideform of glucose with small amounts of the y- or ethylene-oxideform of this sugar are produced. On these assumptions, the rota-tion and low crystallising power of invert-sugar are explained bythe complexity of the mixture.Some evidence in favour of thisis afforded51 by contrasting the reducing powers of sucrose whileundergoing inversion by ( a ) invertase and ( b ) dilute acid bymeasurements of the time taken to decolorise permanganate, but theformula given above is well substantiated by further investigationby Haworth52 of the cleavage products of methylated sucrose. I nprevious investigations, the separation of the cleavage products ofoctamethyl sucrose was (difficult, but heptamethyl sucrose is easilyprepared, and, on hydrolysis with dilute hydrochloric acid, yieldsa trimethyl glucose and a tetramethyl fructose, which are readilyseparated by fractional distillation under a very low pressure.The trimethyl glucose was characterised by further methylation,which gave tetramethyl a-glucose.The tetramethyl fructosedecolorised permanganate, behaved generally as a y-sugar, and,when oxidised by nitric acid, gave an anhydro-acid or semi-lactide,the analysis of which agreed with an empirical formula, C16H30011.A closely reasoned argument shows that the properties of this pointto its formation from an a-hydroxy-acid, which in turn could onlybe formed from the tetramethyl fructose having the formulaOMe*CH,*C(OH)*CH*CH(OMe)*CT-I(OMe)*CH2*OMe.I L O J y51 E. F. Armstrong andT. P. Hilditch, T., 1920,117, 1086.REP.-VOL. XVII. Dsz Ibid., 19966 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.The extensive study of the alkylated sugars, with which thenames of Purdie, Irvine, and Haworth are mainly associated,has obviously opened out a general method for the determinationof the constitution of the di- and poly-saccharides, for now thatthe properties and structures of a large number of alkylated aldosesand ketoses are known, the substances formed in the degradationof polysaccharides may be identified.The original method ofalkylation by means of silver oxide and alkyl iodide is not alwayssuccessful, owing to experimental difficulties, often caused by theinsolubility of the carbohydrate in the alkyl iodide, but now thatthe alternative method of methylation is available in the use ofmethyl sulphate and sodium hydroxide rapid progress has beenmade. An investigation of the constitution of the polysaccharidesby means of their hydrolysis must include the identification of(1) the constituent sugars, (2) their stereochemical form, (3) thehydroxyl groups involved in the coupling of the constituents, and(4) the position of the internal oxygen ring in each sugar.Thesemethods have now been applied with considerable success to theelucidation of the structure of inulin,53 and of the conversion ofcellulose into glucose.54Inulin, being soluble in aqueous sodium hydroxide, is readilymethylated by methyl sulphate to 'dimethyl inulin, which has theadvantageous property of being soluble in methyl iodide.Exhaustive methylation, however, by silver oxide and methyl iodideshowed that the formation of trimethyl inulin representedl thelimit of the reaction.The hydrolysis of this a t looo with 1 percent. oxalic acid proceeded quite smoothly, and yielded a trimethylfructose, which, in view of its strong reducing properties, was un-doubtedly a member of the y-, that is, the supposed ethylene-oxide,series of ketoses. The trimethyl fructose was then converted intothe corresponding trimethyl fructosides, which, on further methyl-ation and subsequent hydrolysis, yielded the tetramethyl y-fructoseobtained by Haworth55 from sucrose. The diagram on p. 67illustrates the great advances made recently in our knowledge ofthe struotural relationship of the four compounds.The yields obtained in the conversion of inulin to trimethyly-fructose show that i t is an aggregate of y-fructose residues, eachketose molecule having lost two hydroxyl groups in the formationof the polysaccharide.Further deductions from this research suggest one of twoalternative formulz for inulin, which undoubtedly has a smallerWI J.C. Irvine and (Miss) E. S. Steele, T., 1920, 117, 1474.6' J. C. Irvine andC. W. Soutar, ibid., 1489.Ks LOG. cit., see p. 65ORGANIC CHEMISTRY. 67Inulin -+ Fructose + SucroseJ. J. ++ 4, +Dimethyl Tetra-acetyl Heptamethylinulin fructose sucroseTrimethylinulin+Trimethyly-fructoseTrimethyly-methyl-f ructosideTet rame thy1y-met hyl-fructosideJ.J.L-Tetra- ace t y Imethyl-f ructoside +Methyl-f ructoside9Tetramethylmethyl-f ructosideTetramethyl-fructose+TrimethylglucoseandTetramethyly-f ructosemolecular weight than that given inGlucoseMethyl-glucoside+(a or P)J.Tet ramet hylmethyl-glucosideTetramethyla-glucoseJ.the literature, anddevelopments of the investigation will be looked for with greatinterest.The conversion of cellulose into glucose has been studied by manyworkers, but not in a strictly quantitative manner, for as Irvineand Soutar point out, the evidence of specific rotation and reducingpower, even when apparently consistent, cannot be held tocharacterise an uncrystallisable syrup as a definite sugar.Someadvance has been made in a recent paper by I<. Hess andW. Wittelsbach 56 on the acetolysis of ethyl cellulose, but in allwork on the hydrolysis of cellulose where a yield of glucose evenapproximating to the theoretical amount has been claimed, in nocase have the results been based on the quantity of a crystallinesugar or of a characteristic derivative actually isolated.The St.Andrews results now described have given, by the degradation ofa purified cotton cellulose, a yield of crystalline derivatives ofglucose equivalent to 85 per cent. of the theoretical amount. Themethod consisted in treatment of the cellulose with acetic anhydrideand sulphuric acid, after which the soluble and insoluble productswere converted into methylglucoside. The methylglucosideobtained was quite free from any isomeric methylhexoside, so that6* Zeitsch. Elektrochem., 1920, 26, 232 ; A., i, 632.0 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.mannose and galactose residues are not present in cellulose.results point to the following formula for cellobiose,TheOH*CH*[CH*OH],*CH*CH-O-CH* [CH*OH],*CH*CH(OH)*CH2*OHL O - I 0- I eH,-OH I-and afford some evidence of the structure of a portion of thecellulose molecule.Nitrogen Compounds.The catalytic formation of amines by the Sabatier process isusually unsatisfactory, owing to the difficulty of separating themixture of primary and secondary amines generally formed.A.Mailhe57 has, however, shown that the hydrogenation ofketazines in the presence of reduced nickel can be used for thepreparation of primary amines if the reaction is carried out atspecially low temperatures (about 130°), higher temperatures con-verting ketazines, and even the low temperatures aldazines,5* intomixtures of primary and secondary amines.On the other hand,catalytic methods appear to be very convenient for the prepar-ation of certain aliphatic and aromatic nitriles,59 which are formedwhen vapours of the esters and ammonia are passed over aluminiumor thorium oxide heated t o 480--500°. The quantitative form-ation of hydrogen cyanide when carbon monoxide and ammoniaare passed over thoria heated a t 430° is a reaction which maybecome of considerable importance.A very easy method of preparing guanidine is described by E. A.Werner and J. Be11,60 who show that commercial dicyanodiamide isdepolymerised a t 1 20°' in the presence of ammonium thiocyanate,giving an 80 per cent.yield of guanidine thiocyanate.The a-methyl and a-ethyl derivatives of hydroxylamine 61 areobtained by the prolonged treatment of the correspondingdisulphonic acids with concentrated sulphuric acid. The potassiumsalts of these acids, RO*N(SO,K),, are formed by the reactionsbetween alkyl iodides and aqueous solutions of potassium hydroxyl-aminedisulphonate, and in general, like the potassium salts of thealkylimidosulphonates,62 NR(SO,K),, are noteworthy on accountof their sparing solubility in water ; thus potassium ethylene-6 7 Comp?. rend., 1920, 170, 1265; A., i, 475.5 9 Ann. Chim., 1920, [ix], 13, 226 ; A., i, 4766o T., 1920, 11 7, 1133.61 W. Traube, H. Ohlendorf, and H. Zender, Rer., 1920, 53, [B], 1477;6 B W.Traube and M. Wolff, ibid., 1493 : A., i, 716.K* Ibid., 1120; A., i, 475.A., i, 717ORGANIC CHEMISTRY. 69diamine-nTN'-tetrasulphonate dissolves only to the extent of0.2 gram in 100 C.C. of water at the ordinary temperature, whilstthe corresponding barium dipotassium is practically insoluble.A convenient method63 of preparing cyanogen chloride on alaboratory scale is the action of chlorine on a 12 per cent. solutionof hydrogen cyanide. It has been shown that the reaction proceedsquantitatively according to the equation C1, + HCN = CNCl + HC1.The pure substance does not undergo polymerisation, but in theabsence of water hydrogen chlorisde causes the slow formation ofcyanuric chloride. ROBERT H. PICKARD.PART 11. -HOMO CY CL I c D I VI s I ON.Theoretical.THE determination of the energy of atomic linkings in carbon com-pounds is intimately connected with that of the distribution ofvalency, and of all the available methods which can assist in throw-ing further light on these problems, it is probably the thermo-chemical that is most free from pitfalls in the domain of theory.Considerable progress has been made in the interpretation of thedata supplied by the heats of combustion of hydrocarbons.Wein-berg1 points out that the heats of combustion of saturated hydro-carbons can be very nearly expressed by assuming that each carbonatom and each hydrogen atom contributes a constant quantityin'dependent of the constitution. On this hypothesis, the heats ofcombustion of ethane and propane show that each carbon con-tributes 96.5 Cal. and each hydrogen 29-65 Cal.Again, from theknown increment for each *CH,* and from the average heats ofcombustion of the octanes, the respective values 96 and 30 areobtained. The conclusion is drawn that the energies of rupture ofC-H and C-C bonds do not materially differ, and although thereseems to be a loophole in this part of the argument, interestingresults follow from the application of the additive hypothesis tothe case of the unsaturated hydrocarbons. The value calculatedfrom the number of carbon and hydrogen atoms in the moleculesubtracted from the observed' heat of combustion gives a measureof the additional energy due to the unsaturated linkings. For ' asingle ethylene bond, the increment thus obtained is about 30, orT.S . PriceandS. J. Green, J . SOC. Chem. lnd., 1920, 39, 9 8 ~ ; A., i, 426.A. von Weinberg, Ber., 191 9, 52, [B], 1501 ; A., ii, 1470 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.15 for each unsaturated carbon atom. For the conjugatedbP*-hexadiene the increment is not 60, but only 16.3, and this isjustifiably regarded as the increase due to the mutually restrictedoscillation of three pairs of unsaturated atoms. If, then, the viewof Thiele, that benzene contains three conjugated double bonds, iscorrect, we have to do with six pairs of unsaturated atoms, andthe incrsment should be 32.6. Actually, i t is 32.7 or 30.3, accord-ing as the value for the heat of combustion of benzene determinedby Roth and Wallasch2 or by Richards and Barry,3 respectively,is accepted.It should be pointed out that the above argumentmight well be reversed, since most chemists will be ready to admitthe cyclic conjugation of the benzene molecule, and if the latteris represented by the formula I, then it would seem thatAp*-hexadiene should be represented by the expression 11. I nMe*C:::XJHthis way, the striking analogies between the properties of certaincompounds containing conjugated double bonds and others of truearomatic type might receive some explanation. From the above,it will be seen that the energy of each carbon atom in benzene isabout 5 Cal. above the normal for the carbon atom of a paraffin,whilst in ethylene the increment is 15 for each carbon atom. Itis therefore particularly striking that in naphthalene andanthracene this increment per carbon atom is also about 5 Cal.Accordingly, all the carbon atoms in these polynuclear hydro-carbons are in a similar condition of unsaturation, and we are ledto postulate complete cyclic conjugation in these cases also.Theortho-quinonoid formula for anthracene (111) which Auwers 4deduces from his observations of the exaltat'ion of the refractiveand dispersive powers of 9-isoamylanthracene becomes IV if com-plete conjugation is assumed. There is nothing in the experimentswhich militates against this view, although a #decisive argument isfurnished against the adoption of the old idea of a central para-linking, since dihydroanthracenes behave optically exactly as ifthey contained two normal benzene nuclei.Annalen, 1915,41)7, 134; A., 1915, ii, 146.J .Amer. Ohern. Soc., 1915, 37, 993; A., 1915, ii, 421.I(. von Auwers, Ber., 1920, 53, LB], 941 ; A., i, 640ORGANIC CHEMISTRY. 71Fajans6 has developed a formula for the calculation of the heatsof combustion and of formation of hydrocarbons from a morefundamentally sound point of view than that of Weinberg, butthe chief interest of his work in relation to the present subjectlies in the applications of his methods by Steigerg and by HUckeL7The former shows that the energy of the C-C linkings in graphiteand in aromatic hydrocarbons is almost identical, and draws theconclusion that there is a close analogy in the arrangement of thecarbon atoms and in the subdivision of their valencies in the mole-cules of all these substances. The latter has employed the con-siderations developed by Fajans and by Steiger to the determinationof the energy of polymethylene rings, in order to compare theresults with those which might be anticipated from Baeyer's theory.The value for *CH,* in open chains is known to be 158 Cal., and theabnormal energy of polymethylenes can theref ore be very simplyestimated by dividing the heat of combustion by the number ofcarbon atoms, and comparing the value for the polymethylene*CH,* thus obtained with the normal.I n this manner, the values170, 168.5, 165.5, 159, 158 are obtained for the methylene groupin ethylene, cyclopropane, cyclobutane, cyclopentane, and cyclo-hexaiie respectively. These results are in general agreement withthe strain theory, but the values obtained for even such simplederivatives as the methylpolymethylenes and also for cycloheptanerequire further elucidation.Sidgwick8 has passed in review the boiling points of a very large$number of position-isomeric benzene derivatives, and has pointedout some hitherto unrecognised regularities and certain interestingexceptions.The derivatives of benzene may be roughly dividedinto two classes, the normal, in which the boiling points of isomericortho-, meta-, and para-compounds #do not differ by much morethan loo, and the abnormal, in which the difference is more thanloo, and usually from 20--80°. I n the normal series the sub-stituents are of the unchangeable type, and may be alkyl (notaryl), alkyloxy-, or ester groups.I n the abnormal series theboiling points of the meta- and para-derivatives are fairly closetogether, whilst the ortho- is much lower; 'the substituents hereare of a reactive type, such as hydroxyl, carboxyl, amino-, andnitroxyl. These relations extend to the solubilities in water, sofar as they have been observed. The isomerides in a normalseries exhibit similar solubilities, whereas in abnormal compounds6 K. Fajans, Ber., 1920, 53, [B], 643; A . , ii, 354.6 A. L. von Steiger, ibid., 666; A., ii, 355.7 W. Hiickel, ibicl., 1277; A . , i, 603.8 N. V. Sidgwick, T., 1920,117, 38972 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.this is not the case; and where one of the substituents is hydroxyl,the unexpected result is noted that the ortho-derivative is farless readily soluble in water than the meta- or para-derivatives.A good example of an abnormal series is that of the nitro-phenols.o-Nitrophenol boils about 80° lower than the m- andp-nitrophenols, and i t is also much less readily soluble in water.The chlorides of the phthalic acids are anomalous, having theboiling points: o-, 2 8 1 O ; m-, 2 7 6 O ; p - , 259O'. I f the explanationis that the ortho-derivative has a ring structure, as seems quiteprobable on chemical grounds, then this view should logically beextende'd to the nieta-derivative also, and the work of von Braun(see below) removes much of the prejudice which might have beenfelt against such an assumption.I n almost all cases a para-compound boils a t a higher temperature than the isomeric meta-derivative, but in eleven series in which this rule is reversed oneof the substituents is always amino- or substituted amino-. Thisindicates a constitutional peculiarity for which no explanation isas yet forthcoming.Some interesting work has been carried out on the influence ofnitro-groups on the reactivity of substituents in the benzenenucleus. Kenner and Parking studied the action of ammoniaand of sodium methoxide on 2 : 3-, 3 : 4-, and 2 : 5-dinitrotoluenes,and explain their results in terms of a hypothesis which may bebriefly stated in the following propositions : ( a ) Metaddirectivegroups activate substituents in the ortho- and para-positions, andortho-para-directive groups have a similar effect on those in themeta-position.(a) The displacement of mobile substituentsdepends primarily on the formation of a molecular additive com-pound which undergoes rearrangement or decomposition leadingto the reaction product. ( c ) The group responsible for theformation of the additive compound is not itself displaced.(d) Steric hindrance may be the orientating factor in a displace-ment by affecting the initial process of addition. This is a some-what complex hypothesis, and i t is unfortunate that it appearst o be necessary to have recourse to that most unsatisfactory ofexpedients, steric hindrance, but the facts are certainly difficultto reconcile with a more simple explanation.I n 2 : S-dinitro-toluene, for example, it is the 2-nitroxyl which is displaced, andthis is explained by assuming that steric hindrance prevents the2-nitro-group from partaking in the formation of an additiveproduct which occurs by the agency of the 3-nitro-group, andtherefore the 2-nitro-group is displaced. With 3 : 4-dinitro-toluene, however, the activating influence of the ortho-para-direc-~4 J. Kenner and M. Parkin, T., 1920,117, 852ORGANIC CHEMISTRY. 73tive methyl group is able in the absence of steric hindrance to bethe deciding factor, and the nitroxyl in the 3-position is displaced.The experiments of Holleman and his collaborators10 on the dis-placement of groups in the dichloronitrobenzenes and chlorodinitro-benzenes are examined from this point of view, and the results are,in the main, shown to be in good accord with the theory.Duringthe present year the latter work has been extended11 to the elevendichlorodinitrobenzenes, and by means of a qualitative and quanti-tative study of the act'ion of sodium methoxide An these isomeridesseveral interesting points have been illustrated. The activity ofa nitro-group, for example, is found to be strengthened by theintroduction of a chlorine atom in the meta-position.Kenner and Parkin give good reasons (Zoc. c i t . ) for rejectingthe theory that the intermediate products postulated have aquinonoid structure, but there is a t least one case, the displace-ment of nitroxyl by methoxyl in s-trinitrobenzene, in which theexistence of a quinonoid intermediate stage is the simplestassumption which can be made to explain an otherwise anomalousreaction.There are a number of cases in the literature of substanceswhich may have a chain connecting the meta-positions in thebenzene nucleus, but Braun and his collaborators have now pre-pared a series of substances which undoubtedly contain such ringsystems and of a type which has hitherto been deemed incapableof existence.The first example was a heterocyclic substanceobtained by the reduction of julolidine methochloride,l2 and thiswas followed 13 by the observation that m-xylylene dicyanide onreduction by means of sodium and alcohol yields as the mainproduct the saturated secondary amine (V) in which the C,H,-group may have the ethylene or ethylidene arrangement.Thequaternary dimethylammonium hydroxide obtained from it in theusual manner loses water and dimethylamiiie on distillation, fur-nishing the unsaturated hydrocarbon (VI), which may be reduced~ H : C Hlo Rec. trav. chim., 1915, 35, 1 ; A., 1916, i, 22.l1 A. F. Rollernan and A. J. den Hollander, ibid., 1920, 39, 435; A., i, 639.l 2 J. von Braun and L. Neumann, Ber., 1919,52, [B], 2015 ; A., i, 87.1s J. von Braun, (Frl.) L. Karpf, and W. von Garn, Zbid., 1920, 53, [B], 98;A . , i, 251.D74 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.by means of hydrogen in the presence of colloidal palladium to thesaturated hydrocarbon (VII).All three substances are converted by oxidation into isophthalicacid. The two hydrocarbons have characteristic odours andabnormally low densities.This significant discovery is certain tostimulate numerous further investigations.Statements at variance with the current stereochemical doctrineare prone t o be regarded with suspicion, and perhaps more par-ticularly when made in connexion with the chemistry of cinnamicacid and its isomerides, for in few branches of research has it beenso frequently necessary to correct or reinterpret published experi-ments. It is now claimed14 that on fusing cinnamic anhydridewith tartaric acid, cinnamates are formed which ‘‘ induce ” opticalactivity in a portion of the cinnamic acid, so that optically activecinnamic acid may be extracted from the fusion by means of lightpetroleum. I f the fact be as stated we may well accept the theory,but much more evidence is needed as to the homogeneity of theoptically active material. An interesting asymmetric synthesisof a novel type is that of I-menthyl d-phenyl-p-tolylacetate, whichis obtained by the interaction of I-menthol and phenyl-p-tolylketenin ethereal solution.15 This represents one of the simplest andleast unexceptionable examples of asymmetric synthesis which hasbeen placed on record.The two stereoisomeric forms of the enolic modification of ethylphenylpyruvate, and also the ketonic modification, have now beenprepared.16 The solid enol (a: m.p. 51-52O) is that which wasalready known.17 On distillation it is slowly changed into a morestable liquid enol ( P ) , and this by the action of sodium acetatebecomes the ketonic modification ( y : m.p. 79O).H-s-Ph Ph*E-HCH,Ph*CO*CO,Et HO*C*CO,Et HO*C*CO,Eta. P a Y -The a- and, P-isomerides are readily brominated a t - 1 5 O , andyield a dibromide which rapidly loses hydrogen bromide a t theordinary temperature with the formation of ethyl phenylbromo-pyruvate. The concordance between theory and practice is com-plete, especially since the y-form can be brominated only in boilingcarbon disulphide, and then yields a complex product.l4 E. Erlenmeyer and G. Hilgendorff, Biochem. Zeitsch., 1920, 103, 79; A.,i, 615.R. Weiss, Monatsh., 1919, 4Q, 391; A . , i, 555.H. Gault and R. Weick, Compt. r e d . , 1920, 171, 395 ; A., i, 675.l7 J.Bougault, ibid., 1914, 158, 1424; A . , 1914, i, 839; J. Bougault and(Mlle) R. Hemmerl6, ibid., 1915,160, 100; A . , 1915, i, 78ORQAJYIC CHEMISTRY. 76There is very little real progress to record in connexion withthe problem of the relation of colour to constitution, perhapsbecause the most active workers in this field are devoting theirenergies to the solution of those more fundamental difficultieswhich their earlier investigations ‘disclosed. Among those whoapply the orgamic chemist’s instinct to this subject Eauffmann isprominent, and the development of his views will be followed withsympathetic interest. A communication 18 which is characteristicof the author’s point of view contains an account of the theoryof the colour of triphenylcarbinol salts based on the hypothesis ofdivisible valency, and also a description of experiments made toillustrate the point that basic function and colour-producingfunction of auxochromes do not run on parallel lines.The isomericdimethoxybenzaldehydes (2 : 5-, 3 : 4, and 2 : 4-) were condensed witha series of substanoes containing a reactive methylene group suchas nitromethane, phenylacetonitrile, and diketohydrindene, and inall cases it was found that the resorcinol derivative was most basicand least coloured, whilst the quinol derivative was least basic andmost coloured and the catechol derivative occupied an intermediateposition. It may be noted in passing that the colourless triamino-triphenylmethyl cyanide prepared from pararosaniline andpotassium cyanide passes into a coloured dissociating cyanide underthe influence of the light of an iron arc.lgTurning to the subject of reaction mechanism, i t is certainlynoteworthy, although not a t all surprising, that certain unsaturatedhydrocarbons containing conjugated ethylene linkings can combinewith negatively substituted diazonium salts with the formation ofnormal azo-compounds.20 Thus the compoundCH,:CMe=CMe:CH*N,*C,H,.NO,is readily obtained from dimethylbutadiene and p-nitrobenzene-diazonium chloride in glacial acetic acid solution.Curiouslyenough, it may be reduced by means of tin and hydrochloric acidto a corresponding aminohydrazo-derivative. The occurrence ofthis coupling reaction is held to support the view that diazo-saltsreact with aromatic compounds by virtue of an addition to a con-jugated system of double bonds.This will be readily admitted,but, in view of the enormously greater readiness with which thereaction occurs in the case of phenols and amines, it seems reason-able to include the unsaturated oxygen or nitrogen atoms in theconjugated system. In this way, too, the theory of Karrer,21 thatI * H. Kauf€mann, Ber., 1919, 52, [B], 1422 ; A., i, 50.I. Lifschitz and C. L. Joff6, ibid., 1919; A., i, 95.2o K. H. Meyer and V. Schoeller, ibid., 1468; A., i, 97.21 Ibid., 1915, 48, 1398; A., 1915, i, 1073.D* 76 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.addition occurs a t the oxygen of phenols or their ethers and at thenitrogen of aromatic amines, is satisfactorily brought into line,and the numerous cases of hydrolysis of phenol ethers duringcoupling become explicable.Various Reactions and Synthetical Met hods.Halogenation.-Chlorine may be introduced into the side-chainof toluene and certain derivatives by treating these substances withaqueous hypochlorous acid at temperatures below Oo.22 It ispossible t o prepare in this manner benzyl chloride, benzylidenechloride, chlorobenzyl chloride (but not dichlorobenzyl d o r i d e ) ,xylyl chloride, and tolylidene chloride.Aromatic nitro-compounds when heated with bromine to a hightemperature in sealed tubes are changed in many cases to corre-sponding bromo-derivatives which often suffer further bromination.The reaction23 is not a novel one, but has not been employedto any considerable extent as an instrument of research.Manyfresh examples are recorded, and advantage is taken of the processto demonstrate that the crude nitration product of anthraquinonecontains in all probability the 1 : 2- and' 1 : 3-dinitroanthraquinones.Following up the clue, the 1 : 3-isomeride has actually been isolatedfrom the reaction mixt~re.~4Su1phonation.-Iodine is a powerful catalyst in sulphonation,and, for example, it is claimed that an excellent yield of o-sulpho-benzoic acid is obtained from benzoic a ~ i d . ~ 5 The catalyst has,therefore, a definite orientating effect .*Quinols reacts with aqueous sodium hydrogen sulphite a t looowith the formation of sodium cyclohexane-1 : 4-diol-l : 2 : 4-trisul-phonate, whilst resorcinol 27 under the same conditions is changed toa substance which appears to be the sodium bisulphite compoundof cyclohexane-3 : 5-dionesulphonic acid.Nitration .-The intensely coloured by-product obtained in thenitration of thymol ethyl ether was first isolated by Kehrmann22 Levinstein, Ltd., H.Levinstein, and W. Bader, Brit. Pat. 134250; A.,z 3 S. N. Dhar, T., 1920, 117, 993.25 J. N. RBy and M. L. Dey, ibid., 1405.* Mr. J. Ogilvie, who has repeated the experiment of the sulphonation ofbenzoic acid under the conditions prescribed in this paper, reports that he isable to confirm the catalytic effect of iodine in the reaction. On alkali-fusionof the product, however, m-hydroxybenzoic acid (m.p. 199-200") was pro-duced, and there was no evidence of the formation of safioylic acid.26 W. Fuchs and B. Elsner, Ber., 1919,52, [B], 2281 ; A., i, 159.27 Ibid., 1920, 53, [B], 886 ; A., i, 645.i, 21.24 Ibid., 1001ORGANIC CHEMISTRY. 77and Messinger,28 and later studied by Decker and Solonina,29 whoregarded the substance as a quinonoid anhydro-salt of dicymyl-hydroxylamine A7-oxide. The discovery that in many cases theperchlorates of these bases can be readily isolated has led to moreextended investigations 30 embracing the action of nitric acid onother phenol ethers. The nitration product of anisole, added t operchloric acid, gives a crystalline precipitate of the perchlorate(VIII), and this may be reduced to di-p-anisylamine, or by verygentle treatment to di-p-anisylnitric oxide (IX).OMe- C,H,* N(: 0): C,H,: O<gb4 NO( C6H,*OMe),(TTIII.) (IX.)The quinonoid perchlorate yields solutions which are pure bluein thin layers and red in deep layers.The nitric oxide has theappearance of copper powder, and is much more stable than thecorresponding diphenyl derivative,31 and this is remarkable, sincedi-p-tolylnitric oxide is less stable than the latter substance.Replacements .--The direct conversion of bromobenzene intobenzoic acid, p-dibromobenzene into terephthalic acid, p-bromo-aniline into p-aminobenzoic acid, and similar transformations inthe benzene, naphthalene, and thiophen series, may be accom-plished by the action of aqueous or aqueous alcoholic potassiumcyanide in the presence of cuprous cyanide a t ZOOO.32 Althoughcopper is the unique catalyst in this reaction, and also in the dis-placement of halogen directly attached t o the nucleus by hydroxylor amino-groups, other elements or their compounds may be ofpractical service in effecting the transforniations of diazonium com-pounds. Thus the double cyanide of nickel and potassium may beused for the preparation of nitriles by the Sandmeyer methodwith good results,33 and cobalt thiocyanate is an excellent catalystfor the conversion of diazonium salts into the corresponding thio-cyanates.Nickel and cobalt salts are, however, ineffective in thepreparation of halogen derivatives through the diazonium salts.Aromatic acids may in certain oases be reduced to aldehydes viatheir anilides and related phenyliminochlorides.These are con-verted by stannous chloride in ethereal solution into the tin double88 Ber., 1901,34, 1626; A . , 1901, i, 484 ; compare F. Kehrmann, Ber., 1919,29 Ibid., 1902, 35, 3217; A . , 1902, i, 767.80 K. H. Meyer and H. Gottlieb-Billroth, ibid., 1919, 52, [B], 1476; A., i, 37.H. Wieland and M. Offenbiicher, ibid., 1914, 47, 2111 ; A., 1914, i, 955.a2 K. W. Rosenmnnd and E. Struck, a i d . , 1919, 52, [B], 1749; A., i, 44.33 A. Korczfnski, W. Mrozlnski, and W. Vielau, Compt. rend., 1920, 171,52, [B], 2219; A., i, 156.182 ; A., i, 64378 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.salts of Schiff’s bases, which may be hydrolysed, and good yieldsof the aldehydes are so obtained.34 Benzaldehyde, cinnamaldehyde,p-hydroxybenzaldehyde (starting from p-ethylcarbonatobenzoicacid), and 3 : 4 : 5-trimethoxybenzaldehyde have been prepared inthis way.Friedel-Craf t s Reaction.-The action of cyanogen bromide onvarious aromatic substances in the presence of aluminium chloridehas been further investigated 35 and good results have been obtained,especially with the phenol ethers, which are converted into nitriles.The method will be serviceable in those cases where the corre-sponding hydroxy-acid is not conveniently prepared by the usualmethods, such as the Kolbe synthesis and the action of bicarbonateson the polyhydric phenols.Cyanogen chloride gives the sameproducts as the bromide, and is almost equally reactive.A modification of the Friedel-Crafts reaction has beendescribed,36 and consists essentially in the employment of anaromatic hydrocarbon with aluminium powder and excess ofmercuric chloride.It is thought that the reaction proceeds inaccordance with the equationC6H6 + A1 + 2HgC12= C,H6AlCl,*HgCl + Hg,and the large excess of mercuric chloride is designed to avoid theproduction of mercury. Using this product as catalyst, a numberof remarkable results have been obtained. For example, thian-thren is prepared from benzene and sulphur in a yield of 85 percent. of that theoretically possible.Closely associated with the Friedel-Crafts reaction in perform-ance, although not in theory, is Hoesch’s synthesis, which, it willbe recalled, is based on the production of the ketimine hydro-chlorides by the condensation of nitriles with phenols by hydrogenchloride in the presence of anhydrous zinc chloride and ether.Hydroxy- and rnethoxy -acetonitriles have now been employed inthis reaction, and condensed with such phenols as resorcinol andits methyl ether and phloroglucinol.In some cases, the use ofzinc chloride is found to be unnecessary, and a 94 per cent. yieldof w-methoxyresacetophenone is obtained by hydrolysing the initialproduct of the condensation of methoxyacetonitrile and resorcinoli n ethereal solution by means of hydrogen chloride.37Pormalclehyde Condensations .-The usual assumption is that thecondensation of formaldehyde with aniline and its derivatives, with34 A. Sonn and Ernst Muller, Ber., 1919, 52, [B], 1927 ; A , , i, 58.35 P.Karrm, A. Rebmann, and E. Zeiler, Helv. Chim. Acta, 1920, 3, 261 ;37 W. K. Slater and H. Stephen, ibicE., 309.A., i, 389. w J. N. Rhy, T., 1920,117, 1335ORGANIC CHEMISTRY. 79the formation of substituted diphenylmethanes, occurs exclusivelyin the para-position with respect to the amino-group. This iserroneous, and the product from dianilinomethane or fromanhydroformaldehydeaniline and aniline is a mixture of 4 : 41- and2 : 4/-diaminodiphenylmethanes in the proportions of approximatelynine to 0ne.38 Examination of the nitro-derivatives of the crudeproduct supplied the first clue, and methods were later evolved forthe actual separation of the constituents of the mixture. Theproduction of 2 : 4/-diaminodiphenylmethane (X) in this condensa-tion is paralleled by that of diaminophenylacridine (XI) in themagenta fusion.NA careful study of the conditions of condensation of chloro-methyl ether and dichloromethyl ether, with aromatic compoundshas led to the elaboration of a novel method for the direct intro-duction of the chloromethyl group into the aromatic nucleus .39Of the various suggested processes, that which depends on thecondensation of the aromatic hydrocarbons with s-dichloromethylether in the presence of zinc chloride appears to be the most satis-factory in practice. It is unnecessary to employ highly purifieddichlorodimethyl ether, the crude oil from the action of hydrogenchloride on 40 per cent.aqueous formaldehyde being utilisable,and i t is even an advantage in some examples to employ the wholecrude product without separation of the aqueous layer, and in thatcase sufficient anhydrous zinc chloride is added ultimately to formZnCl,, 2H,O.Benzyl chloride, p-xylylene dichloride, p-chloro-benzyl chloride, and other similar substances were successfully pre-pared, and the reaction is also applicable to the introduction ofthe bromomethyl group.The condensation of styrene with formaldehyde yields 8-phenyl-trimethylene glycol (XII) and its methylene ether. Anetholegives rise to a similar product, whilst camphene in glacial aceticacid solution is changed by trioxymethylene into homocamphenols* H. King, T., 1920, 117, 988.ag H. Stephen, W. H. Short, and G. Gladding, ibid., 51080 ANNUAL RESORTS ON THE PROGRESS OF CHEMISTRY.acetate.40 Homocamphenol or camphenylidene-6-ethanol has beenoxidised to the corresponding aldehyde and acid, and numerousderivatives have been prepared.CHPb (CH,*OH), CHPh :CH* CH :CH GO-NH,(XII.) (XIII.)CHPh:CH* CH: CH*NH*CO,Me CHPb:CH-CH,*CHO(XIV.) (XV.)Hofmann Reaction.-It is well known that the Hofmann reac-tion for the preparation of amines from acid amides does notproceed smoothly with afi-unsaturated amides, but this is due tothe ready hydrolysis of the unsaturated amines into an aldehydeand ammonia.Experimental details have now been recorded 41applicable to the control of this process, and enabling the finalproduct to be isolated. To take an example, cinnamenylacrylamide(XIII) is treated with sodium hypochlorite in the presence ofmethyl alcohol, and' the product is cinnamenylvinylurethane(XIV) , which is hydrolysed by sulphuric acid to P-benzylidene-propaldehyde (XV).If the process is a reasonably general one, itwill have many applications.Oxidation.-The catalytic oxidation of benzene by gases con-taining oxygen a t temperatures of 300-700° results in the pro-duction of p-benzoquinone and maleic acid.42 The process is clearlyof technical interest, and a large variety of catalysts are claimed,but probably none is so effective as the first-named, which isvanadium oxide distributed on pumice.It is perhaps worth noting, in view of the ever-increasing appli-cation of the method of ozonisation, that potassium ferrocyanidereduces many ozonides of unsaturated substances with theminimum formation of tarry by-products.43 The constitution of anumber of enols has been probed by examining the products oftheir oxidation by 0zone.4~The anodic oxidation of benzoic acid introduces hydroxyl groupsinto the nucleus.45 Catechol, quiiiol, 2 : 5-dihydroxybenzoic acid,and a hydroxyquinolcarboxylic acid were isolated from the product.The oxidation of amines still engages attention, and Gold-4O H.J. Prins, Proc. K. Akad. Wetensch. Amsterdam, 1919, 22, 51 ; d.,i, 42 ; G. Langlois, Ann. Chim., 1919, [ix], 12, 265 ; A., i, 241.41 I. J. Rinkes, Rec. trav. chirn., 1920, 39, 200 ; A., i, 322.4 3 J. M. Weiss and C. R. Downs, J . Ind. Eng. Chem., 1920, 12, 228; A .,45 C. Harries, D.R.-P. 321567 ; -4., i, 675.44 J. Scheiber and G. Hopfer, Ber., 1920, 53, [B], 697, 898; A., i, 487, 552.45 F. Fichter and E. Uhl, Belt?. Chirn. Acta, 1920, 3, 22 ; A., i, 234.i, 426ORGANIC CHEMISTRY. 81Schmidt 46 finds that Bamberger's hypothesis, that phenylhydroxyl-amine is the sole first stage in the oxidation of aniline, is in-adequate, since that substance is not sufficiently reactive to explainthe formation of the polynuclear oxidation products. An addi-tional first stage is therefore postulated in the bivalent radiclePhN:, which polymerises into azobenzene, benzoquinonephenyldi-imine, NPh:C6H,:NH, and emeraldine.By carrying out the oxidation of amines with a free para-position in ether by-means of lead peroxide and anhydrous sodiumsulphate, azo-compounds and quinonearyldi-imines are produced,and, what is still more interesting, the oxidation of a mixture ofamines yields mixed azo-compounds and mixed quinonearyldi-imines.Triphenylhydrazine is oxidised a t - 60° in methyl etherto hexaphenyltetrazane, NPh,-NPh*NPh*NPh,, which can beisolated as a green crust, and forms solutions in ether, which arepale greenish-blue a t -80°, and deep blue a t the ordinarytemperature. This is probably due to dissociation into the radicle,triphenylhydrazyl, NPh,*NPh-*, relatively stable to oxygen, buteasily combining with nitric oxide. Wieland and his school havecontinued the study of the ditertiary hydrazines,47 but the results,although of great interest, are along the lines of previous workemanating from the same laboratory.Tetrabenzylhydrazine showsno tendency t o dissociate, and it appears that this phenomenon isconditioned by the direct attachment of the nitrogen to thenucleus, and that it is intensified when there are ortho-para-directive substituents in the ring.Unsaturation.Pinene, nopinene, and y-pinene have remarkable avidity forhydrogen chloride and hydrogen bromide, so that, especially a televated temperatures, these hydrocarbons will actually decomposeaniline hydrochloride and ammonium chloride, with the formationof the hydrochlorides of the terpenes. Bornyl chloride is alsoformed by double decomposition between pinene and numerouschlorine-containing terpene derivatives, such as sylvestfenedihydrochloride and camphene hydrochloride.48 The observationmay be of practical, as well as of theoretical, interest, since itwould be difficult to devise a more neutral reagent than a terpene,and' this is frequently a desideratum in processes which involve theremoval of the elements of halogen acids.46 S.Goldschmidt, Ber., 1920, 53, [B], 28; A . , i, 226, 258. '' H. Wieland and E. Schamberg, ibid., 1329 ; A . , i, 768.48 0. Aschan, Ofuers. Pirwku Vet. -Sot., 1916, 58 ; A., i, 31882 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The possible number of polymerides of an unsymmetricalethylene derivative of the form aCH:CHb is very great, even whenthe dimerides alone are calculated and the constitution is restrictedto the possible cyclo-butanes and butylenes.Theory indicates twocyclobutanes, each existing in four stereoisomeric modifications,and five butylenes, each of which would have cis- and truns-forms.That is, there are eighteen possibilities, without including theenantiomorphous or racemic niodifications. Puxeddu 49 restrictsthe possible number of polymerides of anethole to eleven, and hasnow succeeded in isolating the seventh known substance of thistype by fractionally distilling in a vacuum, and afterwards crystal-lising the white precipitate obtained by the addition of ferricchloride to an ethereal solution of the anisylmethylethylene.A t 120-180°, two molecules of isoprene rapidly attack one ofp-benzoquinone, with the production of a substance, to which theformula XVI has been provisionally assigned.50 It forms a tetra-bromide and dioxime.The reaction is clearly related to the(XVI.) (XVII.)polymerisation of isoprene itself, with the formation of dimethyl-cyclooctadiene.A further numerous class of similar reactions are those whichinvolve the formation of cyclobutane derivatives from' the ketens.Dimerisation of the latter produces cyclobutanediones, whereaswith ethylene derivatives the addition of ketens yields cyclo-butanones.51 Thus styrene condenses with diphenylketen, withproduction of the compound XVII, and many other examples havebeen recorded. cyclopentadiene reacts with one molecule ofdiphenylketen, whilst N-methylpyrrole reacts with two moleoules,even when the components are applied in molar proportions.Attempts have been made to prepare the optically active camphor-keten, in order t o facilitate by polarimetric methods the study ofthese additive reactions, but only partial success was achieved.The most successful experiments were those on the action ofquinoline on camphorcarboxyl chloride.The resulting solutioncontains the desired product in the free state for a short period,E. Puxeddu, Guzzetta, 1920,50, i, 149; A., i, 481.H. Staudinger and E. Suter, ibid., 1092; A., i, 656,50 H. von Euler and I(. 0. Josephson, Ber., 1920,53, [B], 822 ; A., i, 489ORGANIC CHEMISTRY. 83but it is very reactive, and quickly passes over into its dimerides.The fact that these were isolated in stereoisomeric modifications isopposed to Schroeter's view that these substances are molecularcompounds bound together loosely by partial valencies, and isstrong evidence that they are correctly regarded as normal eyclo-butane derivatives.52Some extremely suggestive results have been obtained in thecourse of an investigation of the behaviour of diphenylnitric oxidetowards other radicles, such as nitric oxide and triphenylmethyl.53Diphenylnitric oxide, Ph,N:O, is apparently the analogue ofnitrogen peroxide, and when treated with nitric oxide a t Oo, theinitial product is probably O:NPh,*N:O, which is the analogue ofnitrogen trioxide.The products actually isolated are the nitroso-derivatives of diphenylamine and p-nitrodiphenylamine, and themechanism of their production is probably as follows.The hypo-thetical intermediate isomerises into diphenylnitroamine,Ph,N-NO,, and then nitrodiphenylamine, NO,*C,H,*NHPh, whichwhen proauced is immediately nitrosated by the supposed inter-mediate, in accordance with the scheme :N02*C6H4*NHPh + O:NPh,*N:O = NO,*C,H,*NPh*NO + NPh2*OH.Auto-decomposition of diphenylhydroxylamine produces diphenyl-amine, which is itself nitrosated according to a similar scheme.That an analogue of nitrogen trioxide is actually produced in thisreaction may be proved by performing the process in the presenceof a secondary base, such as di-p-tolylamine, when large amountsof the related nitrosoamine can be isolated. With triphenyl-methyl, diphenylnitric oxide yields the compound XVIII, theinitial product being so unsaturated that it unites with a secondmolecule of the hydrocarbon. The constitution of the substancefollows from the products obtained by catalytic hydrogenation.These are diphenylamine and p-benzhydryltetraphenylmethane,the nature of which has been elucidated by Tschitschibabin .54(XVIII.)Molecular Rearrangement.The smooth transformation of n-butylaniline into 4-butylanilineby heating with hydrochloric acid or certain metallic chlorides 5553 H.Staudinger end S. Schotz, B e y . , 1920,53, [B], 1105 ; A . , i, 557.53 H. Wieland and K. Roth, ibid., 210 ; A . , i, 304.s4 Ibid., 1904, 37, 4709; A., 1905, i, 125.55 J. Reilly and W. J. Hickinbottom, T., 1920, 117, 10384 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.is of interest, on account of the fact that no rearrangement of thebutyl radicle occurs in the process.It will be recalled thatLadenburg found that propylpyridinium salts gave a-isopropyl-pyridine on heating, and there are many similar instances. Thestatement in the theoretical discussion of the process that thereaction cannot be satisfactorily explained by assuming the inter-mediate formation of butyl chloride is of doubtful validity, andexperimental evidence opposed to the theory of double ,decomposi-tion and re-synthesis is not put forward.Attempts during the present year56 to generalise the Claisentransformation have been quite unsuccessful , and the rearrange-ment of phenolic ethers into substituted phenols on heating appearsto be characteristic of the allyl ethers.B-Naphthyl vinyl ether, which does not undergo the transform-ation, has an intense odour of tangarine skins.57A pinacone-pinacoline type transformation , which involves theconversion of a hydrogenated naphthalene into a hydrindenederivative, is illustrated in the annexed scheme, the reagentemployed being silver nitrate in ethereal solution.58CH*OHWhen benzophenoneoxime is warmed with phosphorus penta-sulphide, i t yields thiobenzanilide as the result of a Beckmannchange, It is now found that the rearrangement is due to theformation of an ester of the thio-oxime, since, if the reaction iscarried out in ethereal suspension, thiobenzophenoneoximehydrogen phosphate, HO-PO(SN:CPh,),, is obtained, and thischanges into thiobenzanilide a t 70° with almost explosiveviolence.59Still another transformation has been discovered which is con-ditioned by, and peculiar to, the allyl group.MethylallylanilineN-oxide, CH,:CH*CH,-O*NPhMe:O, heated in presence of alkaliin a current of steam, is converted into N-phenylmethyl-O-allyl-hydroxylamine, CH,:CH*CH,*O*NMePh.6056 S. G. Powell and R. Adams, J. Amer. Chem. Soc., 1920, 42, 646; A , ,57 J. von Braun and G. Kirschbaum, Ber., 1920, 53, [R], 1399 ; A . , i, 728.58 M. Tiffeneau and A. OrBkhoff, Cornpt. rend., 1920,170, 465 ; A., i, 313.59 M. Kuhara and K. Kashima, Mern. COX S c i . Kyoto, 1919, 4, 69; A.,60 J. Meisenheimer, Ber., 1919, 52, [B], 1667 ; A., i, 35.i, 381.i, 314ORGANIC CHEMISTRY. 85Natural Products.Chlorogenic acid, the tannin-like constituent of coffee, has beenre-examined,61 and found to have a relatively simple constitution.It is apparently a depside of caffeic acid and quinic acid, in whichthe carboxyl group of the caffeic acild assumes the ester function,as shown in the formula :Aspidinol and an isomeric compound, q-aspidinol, are obtainedby condensation of butyronitrile with methylphloroglucinol&monomethyl ether in the presence of hydrogen chloride.62 Thetwo compounds are doubtless the 3- and the 5-butyryl derivativesof the methylphloroglucinol methyl ether, but i t is not yet possibleto assign one formula or the other to aspidinol.In connexionwith the synthesis of plant pigments and other natural productscontaining the phloroglucinol nucleus, it should be noted thatphloroacetophenone, C6H,(OH)3*COMe, can be obtained by thehydrolysis of the pyranol, which is the isolated product of theNencki condensation applied to phloroglucin01.~3The investigation of capsaicin has been continued, and thepungent principle has been regenerated from synthetical vanillyl-amine64 and decenoyl chloride from the decenoic acid obtainedby hydrolysis of capsaicin.65 There is little remaining doubt thatthe substance is decenylvanillylamide. As regards the constitutionof the acid fragment, a little progress has been possible, since thefusion of this decenoic aci'd with potassium hydroxide furnishesacetic acid and an octoic acid with a branched chain. This provesthat the a-carbon atom is joined only to the carboxyl group andone other carbon atom, but i t gives no information relating to theposition of the double bond, because it is well known that oleicacid and many of its isomerides yield acetic and palmitic acidson fusion with alkali hydroxides.The colouring matter of henna leaves, lawsone, has the empiricalformula C,,H60,, and from its chemical behaviour the conclusionis drawn that it is a hydroxynaphthaquinone, and probablyidentical with 2-hydroxy-l : 4-naphthaquinone.66The attack on the problem of carminic acid has been resumed,63 P.Karrer and F. Widmer, Helv. Chim. Actu, 1920, 3, 392 ; A . , i, 441.O6 K. B. Sen and P. C. Ghosh, T., 1920, 117, 61.13* E. K. Nelson, U.S. Put. 1329272; A., i, 543.65 E. K.Nelson, J . Amer. Chem. SOC., 1920, 42, 597; A., i, 380.m G. Tommasi, Buzzetto, 1920, 50, i, 263 ; A., i, 626.K. Freudenberg, Ber., 1920, 53, [B], 232 ; A., i, 32286 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and, largely from analogy to the more closely investigated kermesicacid and the similar behaviour of carminic acid towards reducingand oxidising agents, the formula XIX has been assigned to thes~bstance.~' Carminic acid is optically active, and the side-chainof unknown constitution is doubtless of sugar-like character ; never-theless, the substance is certainly not a glucoside. It yields anocta-acetyl derivative, and by careful treatment a hexa-acetylderivative, which may be oxidised by lead tetra-acetate to anunstable diquinone reducible by sulphurous acid.The moderatedacetylation of carminic acid therefore leaves two hydroxyl groupsin the eposition in the anthraquinone nucleus unaffected.(XIX.)Simonsenm has isolated a new dicyclic terpene from the con-stituents of Indian turpentine from Pinus ZongifoZia, Roxb. Ithas a characteristic, sweet odour, and forms a crystalline nitrosate.On treatment with hydrogen chloride in ethereal solution, ityielded a, mixture of d-sylvestrene and dipentene hydrochlorides,and this conversion into the meta- and para-series a t once sug-gested the possibility that the hydrocarbon is a carene havingone of the formulaeMe d!MeCI/\ /\ /\FH QH2 7% p yH3 p 3 2\/\ \/\CH, CH CH, CH CH, CH\/\CH-CMe, CH-CMe,(A) A*-cWene. ( B ) A4-Carene.(C) Dehydrocarane.C H --C Me,On oxidation by means of potassium permanganate, dimethyl-malonic acid, and, under other conditions, trans-caronic acid, wereobtained, so that this view was amply confirmed,. The molecularrefraction was found to be 44-22, which is in good agreement withthe calculated value (44.19) for a compound containing a cyclo-hexane and a cycZopropane,ring, and which does not contain con-jugated linkings or other causes of optical abnormality. This ina? 0. Dimroth and H. Kammerer, Ber., 1920, 53, [B], 471 ; A., i, 442.68 J. L. Sirnoneen, P., 1920,117, 670ORGANIC CHEMISTRY. 87itself favours the formula A , and is almost decisive against B.C' is improbable, since the glycol obtained by very careful per-manganate oxidation does not react with phthalic anhydride inbenzene solution, an indication that the group *CH,*OH is absent.The terpene is dextrorotatory, and is called d-carene.It is veryprobably d-A3-carene, and is the first naturally occurring terpenewhich has been found to contain the carane ring.AZicycZic Group.When it is considered how difficult it may be to introduce twoalkyl groups into certain esters, for example, ethyl benzoylacetate,which form relatively stable sodium derivatives, it appears remark-able that the alkylation of 2-methylcydohexanone by means ofmethyl or ethyl iodides and sodamide should give rise to 2 : 2-di-methylcyclohexanone or the corresponding methylethyl derivativerespectively.69 The dialkylated ketones condense with benz-aldehyde to form benzylidene derivatives, so that there is no doubtas to the correctness of the constitutions assigned.Considerableimprovements have been effected in the technique of the catalyticreduction of aromatic arnines,70 and the conditions can now beregulated so as to obtain either a cyclohexylamille or a dicyclo-hexylamine as the main product. The catalyst employed iscolloidal platinum, of which a rather larger proportion than usualis necessary. Thus, in reducing a monoamine, a catalyst concen-tration of about 0.6 per cent. is employed, and for a diamine abouttwice as much. The influence of temperature, concentration, andproportion of hydrochloric acid present in the mixture are allmarked. Excellent yields of cyclohexylamine or dicyclohexyl-amine are obtained from aniline, and the reduction of thetoluidines and m and p-nitroanilines has been effected with equallygood results.The methylcyclohexylamines from the three tolu-idines are each obtained in stereoisomeric forms, recognised by theproduction of a- and P-benzoyl derivatives. The new availabilityof these useful bases will probably provide a further stimulus tothe study of partly hydrogenated aromatic hydrocarbons, whichare readily obtained from them by applying the process ofexhaustive methylation.A communication of quite outstanding interest is that of Beesleyand Thorpe,71 dealing with the preparation of derivatives of69 A. Haller and R. Cornubert, Cornpt. r ~ n d . , 1920, 170, 700, 973; A . ,'O A.Skita and W. Berendt, Be?., 1919, 52, [B], 1519; A., i, 27. '' R. M. Beesley and J. F. Thorpe, T., 1920,117, 591.i, 390, 44188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.dicyclobutane and tricyclobutane. A new system of nomenclatureof associated alicyclic systems is proposed, and this is capable ofaccurately expressing in words and symbols the constitutions ofthe most complex interlocked structures. It is simple and logical,but a shortened exposition would serve no useful purpose, ansd theoriginal must be consulted. In view of the fact that the intro-duction of the new nomenclature is a recent event, the compoundsmentioned below are described in the ordinary way, the number-ing of the dicyclobutane ring commencing a t the tertiary carbonatom.fib-Dimethylpropanetricarboxylic acid (XX) is convertedinto the dibromo-ester (XXI), and the latter is found to bechanged by concentrated aqueous potassium hydroxide at a hightemperature into 1 -methyldicyclobutane-2 : 3 : 4-tricarboxylic acid(XXII).CH*CO,H /CH,*CO,H /CHBr*CO,Et\CH,*CO,H \CH,*CO,Et CH*CO,H(XX.) (XXI.) (XXII. )This remarkable compound can theoretically exist in threestereoisomeric modifications, and, in point of fact, three modifica-tions have been isolated, melting a t 1 5 4 O , 1 9 3 O , and 165O respec-tively. The first-mentioned readily yields an anhydride? the thirddoes so with greater difficulty, whilst the second shows no tendencywhatever to form an anhydride. The carboxyl group in position 3is found on the models to point away from the system, and, more-over, methyltricyclobutanetricarboxylic acid (see below) shows notendency to form an anhydride? so that this property in the aboveacids is restricted to the carboxyl groups in positions 2 and 4.On this basis, the three isomerides have the configurations assignedin the following figures:CMe-CH,*CO,H CMe-CHBr*CO,Et CMe<$*CO&(M.p. 154O.) (M. p. 193".) (M. p. 165".)The three acids are formed in approximately equal amount inthe original reaction, and are separated by taking advantage ofthe fact that the acids are insoluble in ether, whilst the twoanhydrides are readily soluble in this solvent. The mixture istherefore heated, and the anhydro-acid derived; from the meso-cis-isonieride (m.p. 1 5 4 O ) extracted. The residue is treated witORGANIC CHEMISTRY. 89acetic anhydride, when the racemic modification (m. p. 1 6 5 O ) isdehydrated, and can be similarly removed, leaving a residue ofthe meso-trans-acid (m. p. 193O). The neatest possible confirm-ation of the correctness of the assignment of the above formulzeis obtained by studying the behaviour of the three isomerides onbromination. The bromo-triethyl ester from the acid melting a t1 5 4 O simply yields a stable bromo-acid when hydrolysed, and thisharmonises with the configuration, because the bromine atom doesnot approach the groups in the molecule, with which it can react.The bromo-triethyl ester from the acid melting a t 165O yields, onboiling with pyridine, a lactonic ester (XXIII), because in thiscase the bromine atom is close to a carboxyethyl group.Whenthe acid melting a t 193O is treated with phosphorus pentabromideand bromine, and the product poured into alcohol, a bromo-deriv-ative is not formed a t all, or, if formed, is too unstable to exist,and by loss of hydrogen bromide passes into an ester of methyl-tricyclobutanetricarboxylic acid (XXIV) . This, again, accordswell with the configuration assigned to the acid melting a t 193O.CMQ(XXIII.) (XXIV. )The acid, XXIV, the preparation of which was brieflyannounced in 1913,72 may also be obtained in small yield by theaction of hot aqueous potassium hydroxide on the tribromo-ethylester derived from PP-dimethylpropanetricarboxylic acid (XX) .From the structural point of view it is one of the most interest-ing substances synthesised in recent years, for the tetrahedralarrangement of the four substituents is concentric with that of thefour groups attached to a methane carbon atom.The symmetryof methane is reproduoed exactly, and enantiomorphism shouldbe possible in this series only when all four groups are different.Again, the tetrahedral unit, C,, has the arrangement of atomswhich is characteristic of the diamond crystal. It is most un-fortunate that a group of substances in which so many crucialtests of the soundness of deductions from the models can be appliedshould be so difficult to prepare in large quantities.The condensation of ethyl aal-dibromo-PP’-dimethylglutaratewith ethyl malonate in presence of alcoholic sodium ethoxide leadsi2 J.F. Thorpe, P., 1913, 29, 34690 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to the formation of a yellow sodium salt, t o which the constitutionXXV was assigned.'3 On hydrolysis by acids, the monobasic acidXXVI is ultimately obtained, and all the experimental evidenceis in agreement with this view of the bicyclic nature of the sub-stances. It is now found that the acid XXVI is produced by theaction of boiling dilute alkali hydroxides on d-diketo-PB-dimethyl-hexoic acid (XXVII), which is obtained 74 on oxidising dehydro-isofenchoic acid by means of potassium permanganate under specialconditions. Too much attention need not be paid to the con-clusion drawn from this experiment that the formulE XXV andXXVI are insufficiently grounded, and that the substances are,in reality, cyclopentene derivatives, because the real existence ofthe fused cyciopropane ring has since been demonstrated in aconvincing manner.75Me,C---C* CO,H 1 ,+2C( C0,Et) *Q:C(OIUa)*OEbHC---GOCMe2<b(C0,F:t).C0(XXV.) (XXVI.)CO,H*CO*CMe,*CH,* COXe(XXVII)It is pointed out that the valencies in the dicyclopentane system,especially the central connecting linking, are from theoretical con-siderations in a state of considerable strain, and far more so thanin the cyclopropane ring of carone. Thus, although carone maybe readily oxidised by potassium permanganate, with the form-ation of trans-caronic acid, it by no means follows that, under theinfluence of the same reagent, the cyclopropane ring in the sub-stances under discussion ought t o be expected to behave in asimilar fashion and to remain intact.As a matter of fact,'thisis not the case, and the ring is broken by potassium permanganate,with the formation of open-chain acids. When, however, the acidXXVIII, which is the initial product of the hydrolysis of XXV, isoxidised by means of potassium ferricyanide and potassiumcarbonate, it gives rise to trans-caronic acid. The formation ofC(OH)(CO,H)*$!K,CH,--- CO co*co,H + CMe,<CMe2<CH2*C*.CH,C( C0,H)*$!H2co CH-- CMe2< I53 W. H. Perkin, J. F. Thorpe, and C. Walker, T., 1901, 79, 729.74 N. J. Toivonen, Annalen, 1919, 419, 176; A., i, 49.75 E. H. Farmer and C. I(. Ingold, T., 1920, 117, 1362ORGANIC CHEMISTRY.91XXVI from XXVII is therefore to be explained according to theabove scheme (p. go), the necessity for which is instructive. !l?hereis an obvious alternative scheme, in which the cyclopropane ringwould be the first to be formed.On account of its formulation by some chemists as an inter-inediate stage in the Wagner transformation, the hydrocarbontricyclene (XXIX) has a special interest, and it has now beenprepared76 by a series of processes from tricyclenic acid (XXX),the constitution of which is not disputed.(XXVIII. ) (XXIX.)C*CO,H(XXX.)The methyl tricyclenate is reduced by sodium and alcohol to thecorresponding primary alcohol, which is oxidised to an aldehyde,the hydrazone of which yields the desired hydrocarbon on heatingat 180-195O with an alcoholic solution of sodium ethoxide.Tricyclene (m.p. 64-65O) is a relatively stable substance, whichmay be oxidised by potassium permanganate in acetic acid solu-tion, with the formation of tricyclenic acid as one of the products,thus showing that the above process has not disturbed the ringsystem. It is converted by heating with sodium hydrogen sulphateinto camphene, but the same change cannot be effected. by meansof zinc chloride in boiling benzene. The hydrocarbon might there-fore be intermediate in the transformation of borneol, but not ofi‘soborneol, into camphene. All arguments of this type are opento the objection that the abnormal energy conditions a t themoment of reaction are not sufficiently taken into account.Homocamphor (XXXI) has been prepared 77 by ring closure ofhydrocamphorylacetic acid (XXXII), itself prepared by distilla-tion of the malonic acid derivative produced in the electrolyticreduction of the condensation product of carnphoric anhydride anddiethyl sodiomalonate.CH,-CH-CH, CH,-CH*CH2*CH,*C0,HI I I 6Mo, I CH, I I y e 2CH,-CMe-CO CH,-CMe*CO,H76 I?.Lipp, Ber., 1920, 53, [B], 769; A., i, 491.77 A. Lapworth and F. A. Royle, T., 1920,117, 743.(XXXI.) (XXXII.92 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The new substance is very like camphor in chemical and physicalproperties, and yiel'ds a similar series of derivatives. I t sisonitroso-derivative undergoes the Beckmann change, with theformation of a substance which yields homocamphoric acid onhydrolysis.This confirms the constitutions assigned to hydro-camphorylacetic acid and homocamphor.Polycyc Zic Aroma t i c Groups.Hydrindene Group.-Ethyl PP-diphenyl-lactate, in contradistinc-tion from the acid itself, dissolves in concentrated sulphuric acidto a green solution, from which 3-phenylindone (XXXIII) andtwo isomeric diphenyltruxones can be isolated .78 The diphenyl-truxones are colourless dimerides of the orange-red phenylindone,and it is interesting to note that only one of them can be reducedt o a tetrahydro-derivative, probably containing twoCPh(XXXIII.) (XXXIV.)*CH*OHgroups, by means of hydrogen in the presence of palladium. Thebrown hydrocarbon, which is prepared by the dehydration of theproduct of the action of magnesium phenyl bromide on diphen-succindandione (9: 12), can be oxidised by chromic acid in coldacetic acid solution, with formation of 2 : 2'-dibenzoylbenzil,C6H4Bz*CO*CO*C,H4Bz, and has therefore the constitutionXXXIV.79A series of similar substances has been prepared and investigated.NaphthaZene Group.-Chlorinated nitronaphthalenes not readilyobtained in other ways may be prepared by the nitration of thenaphthalene chlorides followed by removal of the elements ofhydrogen chloride.Thus naphthalene tetrachloride and nitricacid yield a resinous nitro-derivative, which is transformed by weakalkaline reagents into 5 : S-dichloro-l-nitronaphthalene.80 Anextended study 81 of the reduction of a-naphthylamine showsthat, in the presence of a neutral solvent, sodium and ethyl, butylor amyl alcohols lead to the production of 5 : 8-dihydro-l-naphthyl-amine.T"his is also the product when ethyl or butyI alcohol is'* Remo de Fazi, Uaxzetta, 1919, 49, ii, 253; A., i, 316.7 9 I(. Brand and H. Ludwig, Bet-., 1920, 53, [B], 809 ; A., i, 486.tl F. M. Rowe, J . SOC. Chem. Id., 1920, 39, 241 ; A . , i, 609.0. Matter, D.R.-P. 317755; A., i, 429ORGANIC CHEMISTRY. 93employed alone, but with arriyl alcohol the reaction proceeds further,and ar-tetrahydro-u-naphthylamine is obtained. The explanationis that only under suitable conditions of temperature and alkyl-oxide concentration does the above-mentioned dihydro-derivativeundergo isomerisation to 7 : 8-dihydro-l-naphthylamine, and thatthis isomerisation is an essential preliminary of reduction t o thetetrahydro-stage. Similar results were obtained with naphthaleneitself, which is first reduced t o 1 : 4-dihydronaphthalene, isomerisedto 1 : 2-dihydronaphthaleneJ and only then further reduced tatetrahydronaphthalene.I n the catalytic reduction of naphthaleneand u-naphthylamine dissolved in various solvents and in pre-sence of nickel, it was found that the reduction almost alwaysstopped a t the first stage mentioned above.Anthracene Group.-Phenols may be condensed with phthalicanhydride and its substitution products in the presence ofaluminium chloride, and good yields are obtained when the solventis s-tetrachloroethane.82 The carboxybenzoyl group is intro-duced in the ortho-position to the phenolic hydroxyl, and in manycases the benzoylbenzoic acids formed can be smoothly dehydratedto anthraquinones.For example, 4-chloro-l-hydroxyanthra-quinone can be prepared in this way from phthalic anhydrideand p-chlorophenol.@ In the section (see above) in whichbrief mention is made of the work of Dimroth on carminic acid,it was noted that two of the hydroxyl groups can be acetylatedonly with difficulty. This is a general property of hydroxyl groupsi n the u-positions in the anthraquinone nucleus. 1-Hydroxyanthra-quinone is scarcely attacked un'der the conditions which sufficeto complete the acetylation of the 2-derivativeJ and purpurin andalizarin-bordeaux can be readily changed to mon~-Z-acetates.*~When the hydrochloride of l-aminoanthraquinone is ex-haustively chlorinated in acetic aci'd solution, it yields the com-pound XXXV, which may be reduced by stannous chloride inacetic acid t? 2 : 4-dichloro-1 -hydroxyanthraquinone, or byammonium chloride in acetic acid to 2 : 3 : 4-trichloro-l-hydroxy-anthraquinone.The pentachloro-derivative is hydrolysed by warmsulphuric acid to tetrachlorohydroxybenzoylbenzoic acid (XXXVI),and a t a higher temperature to phthalic acid and 2 : 3 : 4 : 5-tetra-chlorophenol.85Methyleneanthraquinone (XXXVII), a stable , pale yellow, crystal-82 F. Ullmann and W. Schmidt, Ber., 1919,52, [B], 2098; A., i, 53.83 F. Ullmtmn and A. Conzetti, ibid., 1920, 53, [B], 826; A., i, 488.** 0.Dimroth, 0. Friedernann, and H. Kammerer, ibid., 481; A.,a5 K. Fries and E. Auffenberg, ibid., 23 ; A., i, 236.i, 44394 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.line substance, is obtained by the condensation of a cold alkalinesolution of anthranol with an excess of formaldehyde.86OH(XXXV.) ( XXXVI 0 )(XXXVII.)Polynuclear Groups.-Benzanthrone and most of its derivativeswhich have been examined in this connexion readily yield cry-sta.lline oxonium salts.87 The f errichlorides may be isolatedfrom an acetic acid solution containing ferric chloride, but thesalts do not separate in the presence of excess of hydrochloric acid.Indeed, it is necessary to avoid the ad,dition of the latter acid, suffi-cient of which for the formation of the double salt is derived fromthe hydrolysis of a portion of the ferric chloride.A dihydroxy-benzanthrone obtained by condensation of deoxyalizarin andglycerol in the presence of sulphuric acid is found to be readilymethylated, and is regarded as having the constitution XXXVIII.Since the substance, which is termed " benzalizarin," has dyeingproperties on mordants which closely resemble those of alizarinitself, it becomes clear that the propinquity of the two hydroxylgroups of the latter substance to the carbonyl of the quinonenucleus is not so important a factor as has been imagined, andp-quinonoid formulae are suggested for the lakes of alizarin andbenzalizarin.(XXXVIII.)Perylene may be conveniently obtained in good yiel'd by heating2 : 2'-dihydroxy-l : 1'-dinaphthyl a t 400-500° with a halogen com-pound of phosphorus and phosphorous acid.88 This hydrocarbonis 1 : 8-dinaphthylene, and the reaction is evidently one involvingrearrangement, but this is not surprising under the conditions.86 K.H. Meyer, Annaten, 1920,420, 134; A., i, 747.87 A. G. Perkin, T., 1920,117, 696.** F. Hansgirg and A. Zinke, Mona$&., 1919,40, 403 ; A., i, 541ORGANIC CHEMISTRY. 95Compounds containing Boron, Phosphorus, and Hetals.A communication on boranilide has appeared89 which is crowdedwith astonishing statements, but it is necessary to point out that theexperiments as described hardly bear the construction whichis put on them, and the analytical data supplied are quite inade-quate to support even the views on the composition of the sub-stances which have been prepared.The action of aliphatic diazo-compounds on tertiary phosphinesleads to the production of a new class of phosphorus derivativestermed phosphazines. The reaction is an additive one proceedingin acoordance with the scheme :CR,:NiN + PR, + R,C:N*N:PR,.The products are basic, although this property is less developedwhen arylphosphines are the starting points.Triphenylphosphine-benzophenoneazine, PPh,:N*N:CPh,, is obtained from tri-phenylphosphine and diphenyldiazomethane. It is slowlyhydrolysed to benzophenonehydrazone and triphenylphosphineoxide. On being heated in a vacuum it loses nitrogen, and is con-verted into triphenylphosphinediphenylmethylene, PPh,:CPh,,which crystallises in red leaflets, When azides are added to phos-phines the phosphazines which may be assumed to be formed initi-ally decompose spontaneously, with the production of still anothernew type-the phosphineimines.Thus phenylazoimide and tri-phenylphosphine yield triphenylphosphinephenylimine, PPh,:NPh,when mixed in dry ether. This imine reacts with diphenylketenin benzene solution in accordance with the scheme:PPh;N Ph0-43: CPh,PPh,:NPh + UPh,:CO = I I --.+ O:PPh, and NPb:C:CPh,(XXXIX.)The compound, XXXIX, is the first member of the series of theketen-imines.90 An enormous number of aromatic arsenicderivatives have been prepared and described,91 but few newmethods have been elaborated. The introduction of mercury inaromatic compounds is another subject that has been much inves-tigated, and it appears to be possible t o effect substitutions by89 T.C. Chaudhuri, T., 1920, 117, 1081.H. Staudinger and J. Meyer, He&. Chim. Acta, 1919, 2, 635; A., i, 106;Ber., 1920, 53, [B], 72; A . , i, 228.s1 R. G. Fargher, T., 1920, 117, 865 ; W. A. Jacobs and M. Heidelberger,J . Amer. Chem. SOC., 1919, 41, 1587, 1600, 1610, 1809, 1822, 1826, 1834; A.,i, 107-117; compre Brit. Pat. 12818196 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.means of mercuric acetate in substances which are not affected byreagents that might be regarded as much more powerful. Phenolethers react even with aqueous mercuric acetate to yield additivecompounds, which are instantly transformed by sodium chlorideinto products mercurated in the nucleus.A t 50° p-tolyl methylether gives the substance 3CGH,Me*OMe*Hg(C2H3O&,2Hg0, andby subsequent treatment with sodium chloride the substanceC,H3Me-OMe-HgCl.g~Mercuration differs from most substitution processes in that there isvery little regularity, and each case has to be separately investigated.Lead tri-p-2-xylyl has been prepared93 by the action of leaddichloride on the calculated amount of magnesium p-2-xylylbromide, and this crystalline substance exhibits analogy totriphenylmethpl in its behaviour. It is bimolecular in benzene,and its solutions are coloured. A t -40° it combines with brominein pyridine to yield lead tri-p-2-xylyl bromide, whilst in chloro-form a t - l o o the product is lead di-p-2-xylyl dibromide.Alkylderivatives of bivalent tin have not yet been isolated in a purecondition, but the aryl derivatives, as usual, have proved moreamenable and exhibit interesting properties.94 Tin diphenylis obtained by the addition of finely powdered stannous chlorideto an ethereal solution of magnesium phenyl bromide. It is brightyellow, and gives yellow solutions. When freshly prepared it hasthe normal molecular weight, but five-fold polymerisation soonoccurs in benzene solution. R. ROBINSON.PART III.-HETEROCYCLIC DIVISION.THE work now to be reviewed has not equalled that of pre-war yearsin volume, but the progress achieved in various directions, notablyin connexion with the alkaloids, has been such as to merit a fairlydetailed account.A t the same time, one or two investigations,which have extended over some years, appear to have reached apoint a t which they may conveniently be dealt with as a whole.For these reasons, this Report will probably be found to be notmuch shorter than those which have preceded it.Some Aspects of the Addition Theory of Reactions.Although the addition theory of reactions is very widelyaccepted, there is probably divergence of opinion as to whether, forinstance, the equation :92 W. Manchot and F. Bbssenecker, Annalen, 1920,421, 331 ; A., i, 780,g3 E. Krause and M. Schmitz, Ber., 1919, 52, [B], 2165; A., i, 197.94 E. Krause and R. Becker, ibid., 1920, 53, [B], 173 ; A . , i, 340ORGANIC CHEMISTRY. 97is an adequate expressiou of the process of saturation of a doublebond.Thus Kekul6 supposed that the final product was precededby the double molecule (I), whilst more recently it has beenassumed-and the view seems intrinsically more probable-that astill earlier stage is represented by (11). From this point of viewmuch interest attaches to the direct, formation of a cyclic structureby an additive reaction. With the exception of certain reactionsof the ketens, all instances of this kind hitherto known depend onthe union of similar molecules to form polymerides. Although theseproducts are doubtless better represented by formula with ordinaryrather than subsidiary linkages,l it seems more rational t o considerthem as the outcome, not of an instantaneous change, but of a con-tinuous series of gradual changes, the phases of which are repre-sented by (11) and (I).In the writer’s view such a conceptionalso supplies a simple explanation of the frequency with whichfour- rather than six-membered rings are produced in such cases.From the kinetic point of view, a reaction between two moleculesis much more likely to occur than one between three, and similarly,unless other factors of an adverse kind operate, saturation of a pre-liminary product. of the type (11) is more likely to occur by intra-molecular rearrangement to type (I) than by intermolecular reac-tion with another molecule resulting in the formation of a six-mem-bered ring. In illustration of this, a f our-membered heterocyclicring (IV) is produced with guaiacol when o-methoxyphenyl benzyl-idenehydrazinocarboxylate (111) is heated 2 :0HPh:N.N H-CO*O* C,H,*OMe +(111.)OH*C,H,*OMe + CHPh:N*N*CO 4 CHPh:N*N<gg>N*N:CHPh4, I I I(IV.1(VII. )Although a trimeric formula supplies an equally good explanationof the successive formation of benzylideneurazine (V) and of2 0.Diels and H. Grube, ibid., 854; A., i, 505; compare also the poly-REP.-VOL. xm. EH. Staudinger, Ber., 1920, 53, [B], 1073; A., i, 517.merisation of protoanemonin to anemonin, p. 11498 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.urazine itself (VI) on heating the compound with hydrochloric acid,the production of a compound corresponding in composition withthe formula (VII) is only explicable OIL the basis of the dimericformula.That cyclic structures may also result from the combination ofdissimilar molecules is evidenced by the formation of the acidchloride (I) with the corresponding anhydride (11) by the additionof phosphorus trichloride to phenyl styryl ketone in the presence ofacetic anhydride 3 :CEl:CHPh CH*CHPh(1.1 (11.1The reaction is the first in which it has been found that.two valen-cies of the same atom are utilised to satisfy the unsaturation of asecond molecule.Perhaps still more remarkably, it has beenshown 4 that the products of the action of phosphorus trichlorideon aldehydes, which are decomposed by water to form hydroxyphos-phonic acids,5 are to be represented by formulx of the type (111).In this case also a mixture of an acid chloride (IV) and an anhy-dride (V) is produced in the presence of acetic anhydride, thosefrom benzaldehyde being represented by the formulae (IV) andCHPh.0 CHPh.0(V> :\ / PCl* + \ / POCl -+ [ “ y 1 0 - 1(111.) (IV.) (V.)C H Ph-0 CHPh*OH$0 (OH), \ / -+PO-OHW-) (VII.)An unexpected point of difference between the two series of com-pounds is that in this case the free monobasic acid (VI) is suffi-ciently stable to be isolated. It reduces potassium permanganateslowly, whereas the hydroxyphosphonic acid (VII) suffers immediateoxidation.In yet another instance, the formation of a cyclic structure has5.B. Conant and A. A. Cook, J . Amer. Chem. Xoc., 1920, 42, 830; A.,J. B. Conant and A. D. Macdonald, ibid., 2337; A., 1921, i, 69.W.Fossek, Monatsh., 1884, 5, 120, 627; 1886, 7, 121 ; A., 1884, 833;i, 454.1885, 504; 1886, 529ORGANIC CHEMISTRY. 99been presumed. Thus, a mixture of two stereoisomeric forms ofethyl up-dinitrocinnamate is produced by the action of nitrogenperoxide on ethyl phenylpropiolate, but the first product of theirinteraction in light petroleum solution is a labile, crystalline com-pound of the two in equimolecular proportions.6 This productdecomposes into its components if the attempt be made to isolateit in the ordinary way, but, on the other hand, it gradually passesover in a closed vessel into ethyl phenylpropiolate and ethyl dinitro-cinnamate. The reactions are expressed as follows :CPbZC* C0,Et CPh=C*CO,Et1 I2CPhiC*CO,Et + ZNO, + &02 k0, --+ NO, NO, , +CPh&*CO,Et CPhiC*CO,Etalthough it must be observed that no evidence is supplied as to themolecular weight of the intermediate compound.It has also been found necessary to apply ideas of the kind re-ferred to above to certain reactions of benzoxazole.7 The ordinaryformula (I) for this compound represents it as an imino-ether,which on hydrolysis would be expected t o give an o-acylhydroxy-aniline, whilst an o-acylaminophenol is actually obtained.Itcannot be assumed that the compound (11) is first produced, sincecompounds of this type revert to oxazoles when heated:N NHThe change is therefore represented in the following manner :N NNH. Wieland, Ber., 1920, 53, [B], 1343; A:, i, 737.S. Skraup, Annalen, 1919,419, 1 ; A., 1919, i, 598.E 100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.R. Time.cycZoHexy1 ...5 hburs .... 5& ,, ...... 7fr ,,isoButyl..tert. , ,the decomposition of the intermediate product being attributed tothe gradually increasing engagement of (‘ valency lines ” of the ringoxygen atom by one of the hydrogen atoms of the water molecule,and a consequent weakening of the cyclic struct,ure. The velocityof hydrolysis is thus largely dependent on the rate of formation ofthe additive compound, which, in turn, varies with the amount ofresidual affinity available on the carbon atom after the require-ments of tfie group R have been satisfied. The time required for50 per cent. hydrolysis of various derivatives under standardisedR.Time.Phenyl ......... 74 hoursp-Tolyl ...... morep-Anisyl ... I 120 hoursa-Naphthyl thanconditions is theref oreaffinity of the group R.R. Time.Methyl ......... 40 ,,Benzyl ......... 35 minutesn-Hexyl ...... 3 hoursIt will be seen that themisidered to be some measure of theThe following results were obtained :order of these measurements is in generalagreement, with those which may be deduced from observations ofvarious other reactions.5In yet another direction the results of a long series of investi-gations 9 are summed up as showing “ hou7 many factors influencering-formation and rupture, and how little present-day formulzsuffice to explain the contradictory behaviour of apparently simi-larly constituted compounds.” Thus, contrary to what might beexpected, 1 : l-dialkylcoumaranones, as well as the non-alkylatedcompounds, are apparently more stable than l-alkyl derivatives,which frequently suffer rupture of the five-membered ring and givedisemicarbazones instead of the monosemicarbazones obtained inother cases :With p-nitrophenylhydrazine, however, coumaranoaes unsubsti-tuted in the five-membered ring in-general give osazones, this reac-8 Compare, for example, J.v. Braun, Ber., 1904, 37, 2812, 2915; 1907, a, 3914, 3933; 1909,42, 2532; A., 1904, i, 731, 918; 1907, j, 899, 960; 1909,i, 604.9 K. von Auwers andothers, ibid., 1908,41, 4233; 1911, 44, 3692 ; 1914,47,2334, 2585, 3292; 1915, 48, 85; 1917, 50, 221, 1149; 1919, 52, [B], 77, 92;1920,53, [B], 428; Annulen, 1919,418,69 ; 1920, 421, 1 ; A., 1909, i, 45 ; 1912,i.107; 1914, i, 1136: 1915, i, 154, 440, 442; 1917, i, 277; 1918, i, 27; 1919,i, 217 ; 1920, i, 866.H. Meerwein, AnnuZen, 1919, 419, 121 ; A., i, 2ORGANIC CHEMISTRY. 101tion serving t o distinguish them from chromanones, which givehydrazones :N N H*C,H,*NO,co IrThe only exception to this rule so far observed is 3:5-dimethyl-coumaranone, from which a hydrazone is obtained. The formationof 4-bromo-1 : 1 : 3 : 5-tetramethylcoumaranone as the sole productof the action of sodium hydroxide on a-bromoisobutyryl-4-bromo-s-xylenol is similarly in contrast with the product.ion of 2 : 5-dimethyl-chromanone from a-bromoisobutyryl-p-cresol :Me Me COco coWhilst this exceptional behaviour on the part of s-xylenol deriv-atives recalls that observed in experiments on coupling 10 and inFriedel-Crafts syntheses,ll and may be due to differences in thedistribution of affinity, the experimental material a t presentavailable is insufficient to warrant the final adoption of this view.Unsaturated compounds of the type indicated as an intermediatestage in the last of the above reactions form chromanones underthe catalytic influence of alkali, as do their dibromides when alkaliis employed to remove hydrogen bromide.On the other hand,I 0 K. von Auwers and F. Michaelis, Ber., 1914, 47, 1275 ; K. von Auwersl1 I(. von Auwers and E. Borsche, ibid., 1915, &, 1698; A., 1916,and E. Borsche, Ber., 1915,48, 1716; A., 1914, i, 744; 1916, i, 85.i, 34102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.coumarans are obtained from o-allylphenols and coumarones fromthe dibromides of their acetates by treatment with alkali 12 :CHI n explanation of this, it is suggested that the spatial configura-tions of the unsaturated side-chains in the two pairs of compoundsdiffer, and are as represented in the formulz.Another notable reaction is that of 5-hydroxycoumarone-4-alde-hyde, which is prepared from 5-hydroxy-2-methylcoumarone by theaction of hydrocyanic acid in the presence of hydrogen chloride.13This compound, by condensation with acetic anhydride and sodiumacetate, gives the corresponding acrylic acid :and all attempts too produce a cournarin from it by internal con-densation failed.The result is attributed to steric hindrance, butsupporters of the Kekuli5 formula for benzene will probably preferto look upon it as evidence, confirming that of Marckwald adducedmany years ago, of a difference in the mode of linking of the pairsof carbon atoms in the benzene nucleus.The Stability and Formation of Cyclic Compounds.The relative stability of various saturated cyclic structures, con-taining a tertiary nitrogen atom, towards cyanogen bromide andof their quaternary methylammonium hydroxides (Hof mann’sdegradation) has been carefully studied in recent years.14 As aresult it was found that the series tetrahydroisoquinoline, l-methyl-morpholine, dihydroisoindole, pyrrolidine, piperidine, and tetra-12 L. Claisen, Anna’en, 1919, 418, 84; Ber., 1920, 53,, [B], 322; A., 1919,i, 266 ; 1920, i, 325 ; compare R.Adams and R. E. Rindfusz, J. Amer. Chem.SOC., 1919, 41, 648; A., 1919, i, 340.13 P. Karrer, A. Glattfelder, and F. Widmer, N e b . Chirn. Acta, 1920, 3, 541;A., i, 627.l4 J. von Braun, Ber., 1909,42, 2035, 2532 ; 1911,&, 1252 ; 1916,49,2629 ;1918,51, 96, 255; A., 1909, i, 604; 2911, i, 663; 1917, i, 168, 169; 1918,i, 185, 268ORGANIC CHEMISTRY. 103hydroquinoline represented a gradual increase in stability for eachreaction. Dihydroindole, however, one of the most reactive com-pounds towards cyanogen bromide, was the most resistent to theHofmann reaction. The striking observation has now been made 15that the nitrogen ring of the morphine molecule, which also con-tains the grouping *C*C*N* attached by the first carbon atom to anaIomatic nucleus, exhi5its a similar divergence, but in the oppositedirection.It is more stable in the first, and less stable in thesecond, reaction than any of the foregoing systems. Similar varia-ticns in the relative stabilities of a series of compounds towardsdifferent reagents have, of course, been observed in other directions.In considering them, it is perhaps well to remember that, in termsof the addition theory, the stabilities actually compared are ratherthose pf the intermediate complexes, which are not necessarily inthe order of those of the original compounds, and that differencesmay therefore well occur between the results obtained with differentreagents. Furthermore, whilst the conclusions in respect of cyano-gen bromide were obtained by comparative experiments on theseparate compounds, a diffarent method was followed in the caseof the Hofmann reaction.For example, l-o-vinylbenzylpiperidinewas obtained by the distillation of '' piperidyltetrahydroisoquinolin-ium hydroxide " :In this case, therefore, the piperidine is more stable than the tetra-hydroisoquinoline ring, but a consideration of the results of theaction of sodium amalgam on similar compounds 16 suggests doubtsas to whether it is legitimate to extend this conclusion to pairs ofcompounds, one containing the piperidine ring, and the other thetetrahydroisoquinoline ring, and therefore as to whether a givenring structure in the various compounds containing it preservesprecisely the same properties. Thus, from kairoline methochloride,kairoline (40 per cent.) and y-phenylpropyldimethylamine (60 percent.) are obtained :withl5 Idem, Bcr., 1919,52, [B], 1999 ; A., i, 79.l6 J.v. Braun and others, ibid., 1916, &, 501, 1283, 2613; 1917, 50, 60A., 1916, i, 421, 742; 1917, i, 167, 282104 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.whilst N-methyldihydroindole (75 per cent.), p-phenylethyldimethyl-amine (8 per cent.), and o-ethyldimethylaniline (17 per cent.) areobtained from the methochloride of N-methyldihydroindole :CH, CHnCH, UH,Yet lilolidine, prepared by boiling dihydroindole with l-chloro-3-bromopropane, 'but not, be it noted, from tetrahydroquinoline andethylene dibromide,l7 is not broken down by reduction bf itsmethochloride. From 2-methyl-lilolisdine the original base isrecovered with a I 0 per cent. yield of 1 : 2-dimethyl-7%-propyldi-hydroindole 18 :CH2*(IHMe CH,*CHMe CH2*CHBle[ lkMeC1 l h 1 h e\ / \ P H 2CH2 CH2 c*2+ f\l/\yX2 withCyclic Structures of N e w Types.Results interesting in another respect have been obtained by thereduction of julolidine methochloride, from which the original base(63 per cent.) and the compound (I) (37 per cent.) are obtained 19 :CH,*CH,* CH, CH 2* C H ,* CH ,with/ / I-+ /!\-CH2 OH2CH,*OH,*CH, CH,*C'H,*CH,*NMe,/ 1/\--yMe ()?, CH,CH2(1.1 (11.)E.Bamberger and H. Sternitzki, Ber.. 1893, 26, 1291 ; A., 1893, i, 520.l8 J.v. Braun, K. Heider, and W. Wyczatkowska, ibid., 1918,51, 1215 ; A.,l9 J. v. Braun and L. Neumann, ibid., 1919, 52, [B], 2015; A,, i, 87.1919, i. 40ORGANIC CHEMISTRY. 105The constitution of the new base follows from its oxidation to iso-phthalic acid, and its degradation by the Hofmann reaction to anon-aromatic t.ertiary base (11), containing a non-phenolic hydroxylgroup. Although the compound is unique in containing a ringstructure attached to the benzene nucleus in the meta-position, verysimilar ten-membered rings attached in the ortho-position tobenzene nuclei are contained in the products of the Hofmann reac-tion from tetrahydroberberine alkyl hydroxidesY20 and in crypto-pine and certain of its derivatives (compare p. 123).2l It seemsworthy of comment that all the products of this type hithertoobtained in the laboratory are produced, not synthetically, but bythe breaking down of two simpler adjoining structures, and theeasy conversion of the ten-membered ring of cryptopine into thetwo six-membered rings of isocryptopine chloride suggests that insuch ten-membered rings the carbon chain may preserve the con-figuration of the two rings from which it is derived.In spite,therefore, of the existence of the compounds in question, there isstill room for doubtl as to whether their synthesis, properlyspeaking, is possible.A foar-membered heterocyclic system ob a new type appelars tobe present in the prolduct od the action of nitrous acid on camphor-oxalic acid .22 A transient blue cololur suggests thatl the normalnitroso-compound (I) is first produced, but i t gives place to a mono-basic acid, apparently according tot the equationThis acid gives a red coloration with ferric chlolride, and hencecontains an enollic groiuping which, further, undergoes methylationbefore the carboxyl group.Although the acid is merely convertedinto what is probably a stereoisomelride by boiling concentratedpolt'assium hydroaide solution, its dimethyl derivative is easilydecomposed into ammonia and a-ketohomocamphoric acid (11).Further, the acid contains the complex >N*O* as part of a ring,since it is easily reduced by ferrolus hydroxide to1 camphidolne-carboxylic acid (111). Although the nature of the changesCyJ31505N + H2O = CIIHI70,N + CO,.(111.)2o F.L. Pyman, T., 1913,103, 817.21 W. H. Perkin, ibid., 1916, 109, 81.5; 1919, 115, 713.P. Chorley and A. Lapworth, ibid., 1920, 117, 728.E106 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.invollved remains obscure, it is concludeld that the original prsductcontains the skeleton (IV), and of the alternatives which meetthis condition, prederence is given to thatl represented by (V).A Radicle containing Quadrivalent Nitrogen.Dimethyl- and diethyl-tetrahydropyridyls 23 give yellolwish-brownsolutions in alcohol, which, especially in the presence of a littlewater or on warming, gradually become blue. In this conditionthey immediately absorb oxygen, with the formatioln of N-alkyl-pyridinium hydroxides, and give N-alkylpyridinium iodides withiodine.24 The coloured solutions further resemble those of tri-phenylmethyl in their diminished colotur intensity at lowertemperatures.Although no molecular weight determinations arequoted, it' is concluded that dissociation occurs, and that thecoloured solute is a radicle containing quadrivalent nitrogen ratherthan tervalent carbon :The latter may possibly be preselnt in the yelloiw, ethereal solutionojr the pale green chloroform solutio8n, since these give a yellow,amolrphous product with iodine.The dissociation is ascribed to the weakening effect of the variousdouble bolnds on the valencies od the y-carbon atoms, but1 there isno discussion of the meaning, o r the nature, of the change fromtervalent8 carbon to quadrivalmt nitrogen.Stereoisomerism of Terualent Nitrogen Compounds.Well-defined st erwiwmerism of t ervalent nitrogen compoundshas hitherto been observed only in the case of compounds, such asoximes, in which, according to the usual formulie, the directions oftwo valencies are fixed by a double bond, and reference will beza A.W. Hofmann, Bey., 1881,14,1503 ; A., 1881,921 ; compare B. Emmert,Ber., 1909, 42, 1997; 1917, 50, 31; 1919,52, [BJ, 1351; A., 1909, i, 602;1917, i, 221 ; 1919, i, 455.l4 B. Emmert, i b a . , 1920, 53, [B], 370; A., i, 331ORGANIC CHEMISTRY. 107made later to the first case ob such isomerism ofbserved among thehydrazones. A number of cases have, however, now been observedin which the directions of the two valencies are defined byparticipation of the nitrogen atom i n a cyclic structure.A closer examination of the isomerism of methylisopelletierine(I) and dl-methylconhydrinone (11), referred to in last year'sReport, has confirmed it', and led to the discovery of furtherexamples.25 isopelletierine (111), which occurs naturally, and canalso be olbtained by the demethylation of methylisopelletierine, oinre-methylation gives methylisopelletierine alone, thus differing fromdl-conhydrinone (IV) , which gives both this compound anddl-methylconhydrinone. Further, whilst isopelletierine isrecolvered frolm its carboxylic esbr (V) on alkaline hydrolysis, thecolrresponding derivative of dl-conhydrinane (VI) undergoes aremarkable reaction, which may have a significance in connexionwith the processes of plant life, a-2-pyrrolidylbutan-@-one (VII)being produced in excellent yield.Itl is seen that these results areCH, c*2 CH, C'H,/\ - /\ = /\ = A\/ \/?*:! p 3 2 p 3 2 p 2 'H2 p 2 p 2 p 2CH, CR*CH,Et CH, CH*COEt CH, CH-COEt CH, CH*COEtN*CO,Et\/N H\/NMe NMeCH2 CH2 = /\ = /\\/p 2 QHz 7% p 2 p 2 Q"2 QH2.9H2CH2 CHSCOEt CH, CH*COEt CH, CH*COEt CH, CH*CH2*COEtMeN(1.) (111.) (V. 1 (VII.)explicable on the basis of the configurations indicated, and origin-ally assigned to the first pair of isomerides, oln the ground of thefailure through sterio hindrance of dl-methylconhydrinone toreact with semicarbazide, and its slower reaction with hydroxyl-amine and hydrazine. The isomerism in question is preservedwhen methyl isopelletierine and' dl-methylconhydrinone arereduced t~ the, corresponding amino-alcohols, a distinct pair ofproducts being obtained from each.The ketonic group is there-\/NH HN '/ C0,Et.N\/25 K. Hess, Ber., 1919, 52, [B], 1622; 1920, 53, [B], 129; A., i, 86, 329,E' 108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.fore notl essential to the iscmerism, but the formation of the samedl-methylconiine from both series suggests that the oxygen atommay be in the1 preselnt instance. This, however, is apparently ncjitalways so, because the isomeric forms of 1 -methyl-2-propyl(or iso-butyl o r benzy1)-tetrahydroquinoline 26 resemble the above com-pounds in giving different quaternary ammonium salts, and areprobably examples of the same type of isomerism.The considerable difference in properties exhibited by thevarioas pairs of isomerides is in marked contrast to1 the close agree;ment between coniine and isoconiine.This, in conjunction withthe production olf the same methylcofniine from the aboveisomerides, suggests doubts as to1 the reality of their isomerism,and a careful invatigation27 has now shown that isoconiine ismereily a slightly impure folrm of coiniineA whole series of stereoisolmerides has been discovered amongthe 2-acidyl derivatives of indazole.2* Stable compounds areobtained by the actioln olf acetic, propionic, or benzoic anhydrideson indazole, or its derivatives containing substituents in thebenzene nucleus. From acid chloil.ides, however, and either theparent substances in prewmce olf pyridine or their silver salts alone,labile isomerides are produced which more olr less readily passover into the stable forms.The inherent improbability of sucha formula as (I) excludes an explanation based on structuralisomerism, whilst the recovery of each frolm its double compounds(1.) (11.) (111.)/\OH, / - Y H 7 CH, CH, 1 1CH, I CH, 1 OH, I\/\/?\N C,H,-SO,H\-N-.. ' / U\J 1 \CH,W.) (V-)with, for example, mercuric chlocida shows that these are notcases of physical isomerism. It is t,herefora suggested that therelat,io<nship bet,ween them is represented by the formulze (11) and26 M. Freund and E. Kessler, J. pr. Chem., 1928, [ii], 98, 233; A., 1919,i, 283.K. Hess and W. Weltzien, Ber., 1920, 53, [B], 139; A., i, 330.28 K.von Auwers and M. Diiesberg, ibid., 1179 ; A., i, 638ORGANIC CHEMISTRY. 109(111). The analogy tot the oximes suggested by these formulae isstrengthened by the fact that, as with aceltophenoneoxime, so inthe case of 2-acidyl derivatives of 3-niethylindazole, only one formhas been isolated. Pursuing this, the labile acidyl-indazoles areregarded as sym- (111) and the stable forms as antkmrn-pounds (11).In quinuclidine (IV), the three valencies of the nitrogen atomare fixed and directed towards the corners of a tetrahedron. Theprediction is therefore made that itl sholuld be possible t~ obtainsuitably chosen substitution derivatives in enantiomorphous forms,but experimental work in this direction has nolt got beyond theinitial stages.29 I t s development will bet awaited with interest,because the same mnditiolns are present in 2-p-sulphophenyl-2 : 3-dihydro-1 : 2 : 4-naphthaisotriazine (V), the apparent resolutiocn ofwhich was reported some years agol.30The olptical activity of pelletierine and methyl.Zsopelletierine hasbeen reaffirmd.S1Symmetric and ,1 symmetric Synthesis.Consequent upon the elucidation of the structure of scopoline(p.127), an interesting discussi0n3~ has developed as to the pro-cesses by which in plant life racemic mixtures, such as coniine,methylconiine, pelletierine, isopelletierine, methylisopelletierine.atropine, laudanine, scopoline, paricine, cryptopine, arabine, ceva-dine, delphinine, and delphinidine, are sometimes produced.I n themajority of these cases it is not unreasonable to assume that a tsome stage in their synthesis a process occurs independently of theplant organism, which is a symmetrical one. Thus dl-coniine (11)may possibly be prodmed by such a process from optically activeconhydrin (I) : 7T2 /"\"p+ 7% Q 4 -+ p a QH2 2 7% QH2CH, CH*CHEt*OH CH, C:CHEt CH, CH*CH2EtNH(1.1 (11.)It seems, however, improbable that such a hypothesis can applyto the case of scopoline, because four asymmetric carbon atoms are\/NH\/ \/NH29 J. Meisenheimer, Annulen, 1920, 420, 190 ; A . , i, 761.30 T. S. Moore, P., 1914,30, 182.32 K. Hess and W. Weltzien, Ber., 1920, 53, [B], 119; H. Pringsheim, ibid.,G. Tanret, Compt. rend., 1920, 170, 11 I8 ; A., i, 499.1375; K.He5t3, ibid., 1375; A., i, 328, 774110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,involved, and it would become necessary to assume that therna.jority of the st'ages of its formation are spontaneous ,processes.The conclusion theref ore seems inevitable that the plant organismis capable of symmetric synthesis. Although cases of this kind arenot entirely unknown in animal life, for example, the presence ofdl-arabinose in urine as a result of certain disorders,33 they arevery exceptional. It appears, therefore, that the specific action ofenzymes is considerably more pronounced in animal than in plantlife.Cat e ch in.The constitution of catechin has now been practically determinedas a result of the study 34 of the methylated product of reduction ofcatechin tetramethyl ether,35 which, on oxidation with alkaline per-manganate, furnishes an acid, the molecule of which contains oneatcm of carbon less. Since this degradation is found to be commonto compounds containing the ethyl group:R*CH,*CH3 + R*CO,H,it would appear that the reduction product is 3 : 4 : 2' : 4/ : 61-penta-methoxy-aa-diphenylpropane ( A ) , which on oxidation would give13 : 4 : 21 : 41 : 6/-diphenylacetic acid (B), and these conclusions havebeen verified by synthesis.The acid was obtained from0Med'OMe --+ MeO()OMe\/\H O ( " ~ \ ~ H ~ ~ 1 1OMe CH*CO,H\/\Me0 CHEt\ / \ P H 0 O HOH CHI\/ &IOH(1.1 (A.) (B.13 : 4 : 21 : 4/ : 6/-pentamethoxydiphenylcarbinol through the corre-sponding chloride by means of the Grignard reaction.From itschloride and diazomethane, 3 : 4 : 21 : 41 : 6/-pentamethoxydiphenyl-methyl chloromethyl ketone is obtained, which by reduction isconverted into the required propane derivative :C,B,(OMe)3*CH(C02PI:)*C,H3(OMe), --+ C,H,(OMe)3*CH(OH)*C,H3(OMe)2 -+C,H2( OMe),-CH ( CO-CH2Cl)*C,H3(0Me), +C6H2(0~e),'C13[Et0C6H3(0Me)z.34 M. Nierenstein, T., 1920,117,971, 1151.33 Compare C. Neuberg, Ber., 1900,33, 2243; 1902, 35, 1468; A., 1900,35 S. von Kostanecki and V. Lampe, Bev., 1907,40, 720 ; A., 1907, i, 334.i, 539 ; 1902, ii, 417ORGANIC CHEMISTRY. 111The properties of each of these compounds are in accordance withanticipation, and the formula (I) is proposed for catechin, in placeof the older formulze (II)36 and (III),37 according to which theproduct referred t o above would be either 2 : 4 : 6 : 31 : 4’-pentameth-oxy-3-ethyldiphenylmethane (IV) or 3 : 4 : 2’ : 41 : 6/-pentamethoxy-ay-diphenylpropane (V).Each of these compounds has been syn-thesised by the reduction of 2 : 4 : 6 : 3’ : 4/-pentamethoxy-3-ethyl-benzophenone and 2 : 4 : 6-trimethoxypheriyl 3 : 4-dimethoxystyrylketone respectively, and found to differ from the compound in(I=.) (V.)question. Finally, in confirmation of the new formula, reductionof 3-phenylchroman (VI) results in the formation of 2-hydroxy-aa-diphenylpropane (VII), from which 2-hydroxydiphenylacetic acid(VIII) is obtained on oxidation with potassium permanganate.0(VIII. )(=.) (X.1From l-phenylchroman (IX), 2-hydroxy-ay-diphenylpropane (X) isobtained, and found to be stable towards permanganate.3836 8.von Kostanecki and V. Lampe, Ber., 1907, a, 720; A,. 1907, i, 334.87 A. G. Perkin and E. Yoshitake, T., 1902,81, 1172 ; compare H. Ryan and38 (Miss) A. Greenwood and M. Nierenstein, T., 1920,117, 1694.M. J. Walsh, Sci. PTOC. Roy. Dub. SOC., 1916, 15, 113: A., 1916, i, 722112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The evidence is therefore so complete that it suffices merely torefer to another in~estigation~3~~ in which the identity is affirmed ofthe methylated reduction product with pentamethoxy-ay-diphenyl-propane, although, remarkably enough, in other respects substan-tially the same account is given of the preparation and propertiesof this compound.I n the circumstances, also, less interest attachesto experiments on the synthesis of compounds,39 the structure ofwhich is in close agreemkt with the formula (11). Thus, by therespective condensations of 5-hydroxy-2-methylcoumarone and5-hydroxy-2- methylcouma8ran with benzonitrile in the presence ofhydrogen chloride, 5-hydroxy-2-niethyldepsenone (I) and 5-hydroxy-2-methyldepsanone (11) .are obtained, and from these by reductionthe corresponding secondary alcohols :The A n thocyanins.The evidence for the constitution of the anthocyanins,--.,--trecordedscme years ag0,40 was rounded off by a synthesis of pelargonidinedescribed in a paper,41 which, however, has only recently becomeavailable in this country.By condensation of 2 : 4 : 6-trihydroxy-38a K. Freudenberg, Rer., 1920, 53, [B], 1416 ; A., i, 752.39 P. Ksrrer and F. Widmer,HeZv. Chim. Acta, 1919, 2, 454 ; A., 1919, i, 595.40 Compare Ann. Reports, 1914, 11, 138; 1915, 12, 156.41 R. Willstiitter and L. Zechmeister, Xitzungsber. Preuss. Akad. Wiss.Berlin, 1914, 34, 886; A., i, 561ORGANIC CHEMISTRY. 113benzaldehyde with sodium methoxyacetate and the correspondinganhydride, 5 : 7-dimethoxyacetoxy-3-methoxycoumarin (I) is ob-tained. This compound, by successive treatment with sodium hydr-oxide and diazomethane, gives 3 : 5 : 7-trimethoxycoumarin (11),which reacts with magnesium p-anisyl bromide to form 3 : 5 : 7-tri-methoxy-2-p-anisylpyrylium chloride (111), from which the methylgroups are removed by means of hydriodic acid.From the iodidethus produced a chloride (IV) is obtained, which is identical inevery respect with that of natural pelargonidine 42 :0 0Some other Plant Products.Anemonin (I), which is obtained with anemonic acid and proto-anemonin by the steam distillation of certain varieties of Anemoneand Ranunculus 43 has now been shown to be an unsaturated lactone.It is a doubly unsaturated compound of the formula C,0H804,which exhibits the reactions of the carbonyl group,44 yields oxalicand succinic acids on oxidation, and by aoid or alkaline hydrolysisis converted into anemoninic acid (11). The last is an unsaturatedcompound, with reducing properties and existing in stereoisomericfcrms, which gives y-ketopimelic acid on oxidation.By catalyticreduction of anemonin,45 a tetrahydro-derivative (111) and, finally,sebacic acid are produced, whilst a dihydro-derivative (IV) is pro-duced in the presence of sodium amalgam, and this is converted byhydrolysis into anemonolic acid, which is found to be identical withdilzevulic acid (V), and is obtained directly from anemonin by the4* R. Willstiitter andE. K. Bolton, Annalen, 1915, 408, 42; A., 1915, i, 283.43 H. Beckurts, Chem. Zentr., 1885, 776; A., 1886, 865.44 I b d . , Arch. Pharm., 1892,230, 182; A., 1892, 1241.45 Y . Asahina and A. Fujita, J . Pharm. SOC. Japan, 1919, 471 ; 1920, 1 ;1920, No. 461 ; A., i, 70, 493, 678114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.action of cold hydriodic acid.following scheme :The changes are represented by theCH:CH CH,.C< CH*yH, CH,*C< CH,*CH2--f I 1 CE,*$Z€, CH*QH,0 - - bCH,'C<(J-COCH CI 2' <o& u---co -4c r - I , * c ~ 4 0 cJ3,*c<o-cc)I \1 1 CH:CH I(111.1 J.Sebacicacid(1.1 w.1x J.?3,*CO*CH:CH*C02H ~H,*CO*CH,-CH,*CO,HCH2*CO*CH,*CH2*C0,H CH,-CO*CH,*CH,*CO,H(11.1 (V.1This interpretation is supported by the synthesis of protoanemonin(VI), a vesicant substance from which anemonin is derived by spon-taneous polymerisation.Acetylation of j3-bromolzvulic acid resultsin the formation of a lactone (VII), from which the elements ofhydrogen bromide are removed by means of sodium acetate. Theproduct, doubtless acetylacetoacrylic acid, on distillation furnishesprotoanemonin :CH, CHUr*yH2 --+ CH,*CO*CHBr-CH,*CO,H + AcO >c<o---co(VII.)m.1Anemonin has been similarly synthesised from dibromoangelica-lactone.Hyptolide, another plant product, is also considered to be anunsaturated lactone, and is formulated as a derivative of dihydro-pyrone 46 :fjH*CMe,C H C 0 0 >CMe* [CH*OAcJ 3*CH,.Elsholltzioine, a ketone, C,,H,,02, obtained by steam distillationof Elsholtzia cristata,47 yields isovaleric acid on oxidation, and byt,reatment with amyl nitrite and soldium ethoxide is degraded to3-methylfuran-2-carboxylic acid (homopyrojmucic acid), abehaviour which is reproduced by the synthetic ketones obtained46 K.Gorter, Bull. Jard. bot. Buitenzorg, 1920, [iii], 1, 327 ; A., i, 494.47 Y .Asahina and Y . Murayama, Arch. Pharm., 1914,252, 435 ; A., 1015,i, 429ORGANIC CHEMISTRY. 115by the action of magnesium alkyl haloids on pyromuconitrile.These reactions and the reduction of its hydrazone to 3-methyl-2-isoamylfuran (11) all point to the composition of the compound asbeing represented by the formula ( I ) . 4 *H--G M e 8 8-8 MeCH C*CO*CH,*CHMe, * CH C*C(:N*NH,)*CH,*CHMe, *0fiH-yMe .CH C*CH,*CH,*CHMe,\/ \/0(1.1\/0(11.1The Gly oxalines .An investigation of the orientation of substitution derivativesof glyolxaline has given interesting results. Direct nitration,4Q andprobably also direct sulphonation,50 takes place in the 4-position.On reduction by cold stannous chloride solution, the 4-nitro-deriv-atives of 5- and 2-methylglyoxalines, and of glyoxaline itself,respectively give, notl the aminoccompoundsl (a small proportion inthe case of the 5-methyl derivative being excepted), but a-alanine,a-arnino-a-iminoethane, and glycine.The course of the changes inthe last two cases is represented as follows: 51[~~2"H>CMe] -N -+ :2>CMeAlthough this is a plausible view of the react,ion, it seems not veryclear by what process the amino-compounds are converted intoglyoxalmes. The hypolthesis, which may first suggest' itself to the*a M. Asano, J . Pharm. Soc. Japan, 1919, 999 ; A., i, 495.48 R. G. Fargher and F. L. Pyman, T., 1919,115, 217.so F. L. Pyman and L. A. Ravald, ibid., 1920,117, 1429.R. C. Fargher, iW., 668116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.reader and ascribe the change to a hydrolysis of the aminederiv-ative, reacting in t'he iminol-form, would probably not be accept-able, because 4-amino~5-methylglyo~xaline shows the reactions of atrue amine, whilst 2-aminoglyoxaline is a molnoacidic, non-diazotisable base, which doles nott give a belnzylidene derivative.It is therefore regarded as an imino-colmpound, although in thiscase, its stability towards acid may seem remarkable.The R hodanines.The results of two inveekigations polint to t<he, existence oftautolmwism in the rholdanine series.Thus, whilst' rhodaninegivw a coloarless dibenzoyl derivative (I), a yellow monobenzoylderivative (11) is obtained from benzylidenerholdanine.52 Further,C( SBz)==T'<C(: CHPh) C 05-methyl-3-ethylrhodanine-5-acetic acid (111) is obtained in anoptically active form by the condensation of soldium Z-methyl-bromosuccinat e with potassium et hyldithiocarbamat e, but 3 -phenyl-5-methylrholdanine (IV), prepared from phenylthiocarbamide andd-thiol-lactic acid , is inactive, olwing to racemisation of the initialproduct through its enolic f0r111.63NEt -- csS<CMe(CIH,*CO,H)*bOCS-YPh8<C€€Me-C0The Quittoline Group.The well-known reactivity of 2- and 4-substitaents in thepyridine nucleus is furtheir eaemplified by the preparation of a-and y -quinollinesulphonic acids by boiling the correspondingchloro-compounds with a solution of sodium hydrogen sulphite.64Similarly, the acids, which may also be prepared from the thio-quinolines, on treatment, with phosphosue pentachloride give, notthe cosrespoinding sulphonyl chlorides, but' the chlcxoquinolines,and the a-sulphonic acid is coaverted into carbostyril by simplyboiling it with water.The P-isomeride, which is obtained in anst C. Griinacher, Helv. Chim. Acta, 1920, 3, 152: A., i, 253.53 S. Kallenberg, Ber., 1919, 52, [B], 2057 ; A., i, 90.51 E. Bssthorn a?d B. Gaissslbrecht, ;5;d., 1920, 53, [B], 1017 ; A., i, 563ORGANIC CHEMISTRY. 117indirect manner, is a stable compound, from which a sulphonylchloride can be prepared in the usual way.The total synthesis of quinine and its derivatives is .nearingcompletioln, since methods are nolw available for dealing withparticular cases of each stage of the problem.As these may wellprove adequate folr the purpose in view, it seems appropriate toindicate briefly the present’ position.(a) The syntheses of quinio and cinchonic acids from quinolineand metholxyquinodine, respectively, have been ref erred to inprevious Reports,55 whilst the communication is promised of resultsoibt,ained by the use of Knoirr’s quinoline synthesis.56( 6 ) Fosr the preparation of appropriate derivatives ofP-4-piperidylpropionic acid, hitherto certain less valuablealkaloids of the cinchonine group have been subjected to degrada-tion. F o r example, cinchotine (dihydrocinchonine) (I) is con-verted into cinchoticine (cinchotoxine) (11) , The dimethosulphateof A‘-benzoylcinchotoxine (111) is then converted by oxidation toCHEt*CH-CH, CHEt*CH-CH, CHEt*CH-CH,I 160\/\/ NMe,SO,(111.)F‘CHEt- CH-CH,N-benzoylhomocinchololeupone (IV) .57 The synthesis proper ofthese acids is now foreshadolwed by that of the parent 8-4-piperidyl-55 Ann.Reports, 1918,15, 113; 1911, 8, 142.56 P. Rabe and K. Kinder, Ber., 1918, 51, 1360; A., 1919, i, 34.67 A. Kaufmann, E. Rothlin, and P. Brunnschweiler, ibid., 1916, 49, 2299 ;A., 1917, i, 50; P. Rabe and K. Kinder, Zoc. cit118 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.propionic acid as the product of reduction of B-4-pyridylacrylicacid, which may be obtained from y-picoline and chloral:Me ,Cy2 C H (0 H ) C C1, CH:CH* C0,HCI ./\ /\- + I 1 I I - +\/ G 'h/N NCH C ET,*CH,* CO,HNHSince it has also! been found possible to convert nicotinic acid intoB-ethylpyridine,58 there is a goold prospect of preparing homo-cincholeupone from y-picoline-8-carboxylic acid, which itself isaccessible by synthelsia.Owing, however, to the presence of twoasymmetric carbon atoms in the folrmula, the synthetic product'will consist of four isomerides, olf which olnly one will serve forthe, synthesis of the. natural alkaloids. Further, special precau-tions will, of colurse, be required in connexion with the unsaturatedgroup when the attempt is made to synthesise homomeroquinenine,from whioh cinchonine and quinine themselves are derived.( c ) The coadensation of ethyl cinchonate or ethyl quinate withethyl N-benzoylholmo~incho;leupone by means of the Claisen reac-tion, and subsequent elimination of the benzoyl and carbethoxylgroups, has resulted in the respective sptheses of dihydro-cinchoticine 59 (I) and dihydroq~inicine,5~a which have been con-C,H,N*CO,Et + CO,Et-CH,*CH,*CH<~~~~~~>NBz +C,H,N* CO* CH(C0,E t)*CH,*CH<~~!&~~~>NBz +verted by known methods 60 into dihydrocinchoninone and dihydro-quininone respectively.From these, ke,tmes, dihydrocinchonineand dihydrolcinchonidine on the o'ne hand, and dihydroquinine anddihydroquinidine on the other, are produced by reduction in thesame manner as quininone yields quinine and quinidine.68 P. Rabe and K. Kindler, Zoc. cdt.59u Ibid., Ber., 1919, 52, [B], 1842; A,, i, 78.6o Ann. Reports, 1918, 15, 113.59 IbidORGANIC CHEMIST&Y.119The structure of cinchonine being clear, the greater prospect ofdetermining those of its isomerides has led to renewed investiga.-tions of their relationships to the alkaloid. Apart fromcinchonidine, the stereoisomerism of which with cinchonine isrepresented by the formulz (I) and (II),61 and the ketoneCH,:CH*CH-CH-CH, CH,:CH*CH-CH--CH,I I CH, I I I i H 2 UH, I I l l j a ~ , ICH,*N--CH CH,*N--CHI II /\/\I l l\/\/NI bH, I Ij y2 1CH,*N-CHI-c,H,-o-~H I(111.)dnchotoxine, there are known a-isocincholnine (cinchoniline),P-isocinchonine (cinchonigine) , and apo- or allo-cinchonine. Theseare all derived from cinchonine by the action of hydrochaloid orsulphuric acids, olr by elimination of the elements of the hydrogenhaloids from its hydroLhaloId additive products.apoCinchonine,like cinchonine itself, reacts as an unsaturated hydroxylic com-pound, but the others do not, and have therefore been consideredto be internal ethers.62 This has been confirmed in the case ofthe a-isomeride, which is stable towards dilute mineral acid, butis converted by dilute acetic or phosphoric acids into a hydroxy-dihydrocinchotojxine (IV), from which a hydroxydihydrocinchonin-one (V) can be obtained by the general reaction previouslymentioned .63 The structure of cinchoniline is therefore repre-HO*C,H,* CH--CH-CH,I I CH2 I i +H, IYCH,*NH CH,IHO*C,H,*CH-CH-CH2I1 CH, I I CH,*N-CHI 60 CO/\A I l l\/\/N(Ti \/N(IV- 1 (V.1P. Rabe and others, Annalen, 1910, 373, 8 5 ; A., 1910, i, 417.s2 W.Koenigs, ibid., 1906, 347, 185; A., 1906, i, 762.63 P. Rabe and B. Bottcher, Ber., 1917,50, 127; A., 1917, i, 281120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sented by the formula (111), the nature of the group *C,H,* beingleft undetermined. On other grounds, however, this would appearto have the ethylidene structure, since u-hydrolxydihydrocinchoninegives the iodolform reaction, and therefore probably contains thegrouping CH,*CH=OH*.64 This compolund, which is obtained bythe addition of the elements of water t o cinchonine, is probablystereoisolmeric with the P-compound, prolduced simultanm~usly,since both on dehydration give a- and P-isocinchonines andapocinchonine, althosugh in relative proportims, which are not thesame in each case.65 Further, altholugh the three isomerides ofcinchonine, on treatment with hydrogen brolmide, form the samehydrobromocinchonine, this is accompanied in the cases of8-isocinchonine and apocinchonine by hydrobromo-apocinchonine.Also cincholnine and u-isocinchonine give the same hydroiodo-cinchonine, but P-isocinchonine and apocinchonine give hydroiodo-apocinchonine.Itl is therefolre concluded that a-isocincholnine issterically related to cincholnine and P-isocinchonine ta apo-cinchonine, the relatiolnship of the isomerides being expressed bythe formula: 66Cinc honine . Cinchonigine and cinchoniline.CR,*CH :C,,H,,N,: CH* OHapocinchonine.By t4reatment of cincholnidine with sulphurio acid, there results,besidesl p- and apocinchonidines, a hydrolxydihydrocinchonidine,which gives the iodo8olrm reactioln, and o a dehydration furnishesp- and apocinchonidines but no internal ether.This deviationfrom the behaviour of the hydroxydihydrocinchoaines leads to thesuggestion of structurally distinct formulz for the hydrolxy-dihydra-derivatives olf cinchonidine and1 cinchonine.67 These,however, need not be reproduced here, since the reader will prab-ably find it difficult to reconcile this view with the, stereoisomericrelationship od cincholnine to cinchoaidine. The writer prefers toconsider the difference in question as explicable by assigning theformula (I) to cinchonine, leaving the formula (11) forcinchonidine.64 E. LBger, Compt. rend., 1918, 166, 903; A., 1918, i, 304.65 Idem, ibid., 1919, 168, 404; A., 1919, i, 170.66 Idem, ibid., 1918, 166, 255, 469; A., 1918, i, 182, 232.67 Idem, ibid., 1919, 169, 67; A,, 1919, i, 451ORGANIC CHEMISTRY. 121Quinoline Byes.The constitmution of the isocyanines has been variously repre-sented by the formulae (I), (11), and (111) :N N/\1 /\Alk.Alk. XAlk. X(1.1 (11.1CH CH(111. ) W.)of which (11) alone explains the formation of identical productsfrom unsubstituted quinolines and from their 4-chloro+deriv-atives.68 Against (111), it has been sholwn6Q that the methioidide,of the synthetic product (IV) resulting from the reduction olf thecondensation productc of o-nitrocinnamaldehyde and quinaldinediffers entirely in its propertieis from the isocyanines.Further-more, dimethylisocyanine acetate, on oxidation, yields l-methyl-2-quinolone and cinchonic acid methochloride (hydrochloric acidbeing used in separating the two)? It will be seen that this resultfavoars a formula of the type (V) ratheir than (11) for the/-\Me \-/ /\/\ Me A/\\/\/ x/ \-/ \/\/ x/ \J\x/ \-CH:I I I -+ \N/-\C02H+0:I I 1NMe NMe(V.1(VI.)68 A. Kaufmann and E. Vonderwahl, Be?., 1912,45, 1404; A., 1912, i, 502.70 W. H. Mills and R. 8. Wishart, ibid., 579.W. H. Mills and P. E. Evans, T., 1920,117, 1035122 ANNUAL REPORTS*ON THE PROGRESS OF CHEMISTRY.isocyanines, but it is probable that the two represent virtuallytautoimeric colmpounds. It1 is therefore not' surprising that. dyesof the isocyanine type are also obtainable71 from the alkyl haloidadditive, products of sufficiently pure lepidine72 and its homo-logues.From analogy, the cyanines almoet, certainly correspondwith the formula (VI).Thisdiethylcarbocyanine is better prepared by the action of potassiumhydroxide and formaldehyde on a mixture of the ethiodides ofquinoline and quinaldine than on quinaldine ethiodide alone ;yet the latter is alone concerned in the reaction. By oxidation ofdiethylcarbocyanine bromide with dilute nitric acid, quinaldinicacid ethyl nitrate (VII) is produced, whilst by the action ofpotassium permanganate on the acetate, 1 -ethyl-2-quinolone (VIII)is obtained. The formula (IX) is therefore adopted for pinacyanol.The constitution of pinacyanol has also been elucidated .72a/\Et NO,/\ Et X(VII.) (IX - 1 (VIII.)I n view of the importance of these compounds in codour photegraphy, and the fact that hitherto their manufacture had beena German monopoly, activity is being displayed in varioas direc-tions in wo'rking out the details of their preparation.73The C'helidonium Alkaloids.8-Homochelidonine, an isomeride of cryptopine, resembles it inits physiological action, and in that its oxidation by mercuricacetate results in the displacement of two hydrogen atoms by anE.Q. Adams and H. L. Haller, J. Amer. Chem. SOC., 1920, 42, 2389 ; A.,L. A. Mikeska, ibid., 2396; A., 1921, i, 54.W. H. Mills and (Miss) F. M. Hamer, T., 1920, 117, 1550; compare0. Fischer, J . pr. Chem., 1918, [ii], 98, 204; A., 1929, i, 172; L.E. Wise,E. Q. Adams, J. K. Stewart, and C. H. Lund, J . Ind. Eng. Chem., 1919,11,460; A . , 1919, i, 416.'* H. Barbier, Bull. SOC. chim., 1920, [iv], 27, 427; A., i, 568; L. E. Wise,E. Q. Adams, J. K. Stewart, andC. H . Lund, J . Ind. Eng. Chem., 1919,11,460 ;A., 1919, i, 416; L. A. Mikeska, H. L. Haller, and E.Q.Adams, J. Amer.Chem. SOC., 1920,42, 2392; A., 1921, i, 54; (Sir) W. J. Pope, J . SOC. Chem.Id., 1920,39, 3'70~.1921, i, 53ORQANIC CHEMISTRY. 123oxygen atom.by the formula (II),'* that for cryptopine being (I) :It is therefore called allocryptopine, and representedMe0(1.1 PI* 1M e GI(111.)In conformity with this, nZZocryptopine is converted by treatmentwith ph osphoryl chloride into dihgdroberberine methochloride (111),just as isocryptopine chloride is obtained from cryptopine. Simi-larly, dihydroallocryptopine (IV) gives tetrahydroberberine metho-chloride (V) :--tMe(IV.1M e CI(V.)m e authors of the formulze (I and 11) have each expressed somemisgivings in attributing a ten-membered ring structure to natural74 J. Gadsmer, Arch. Pharm., 1919, 257, 298; 1920, 258, 148; A., i, 75,872124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.products. It is, however, now suggested that the salts of thesealkaloids, which is the form in which they occur naturally, containtwo six-membered rings, and that the ten-membered ring is onlyproduced when the bases are isolated. The changes involved areformulated as follows :Me c1 Me OHThis view readily explains the fact that the bases are only graduallyprecipitated from solutions of their salts by alkali.Sufficient progress has been made towards the determination ofthe constitution of chelidonine and a-homochelidonine to permit thededuction of provisional formulze for these alkaloids as a workingbasis. They differ from allocryptopine in that on oxidation withmercuric acetate, they merely lose two atoms of hydrogen.Thereaction serves, however, to connect these compounds with chelery-thrine, since the product from a-homochelidonine has been identifiedas dihydrochelerythrine.Codeine.A considerable advance towards the determination of the consti-tution of codeine and its congeners has been made by the prepara-tion of two structurally distinct forms of tetrahydrodeo~ycodeine.~~Of there, the a-form, which had been previously obtained fromdeoxycodeine by means of sodium and alcohol, was considered to bea dihydro-derivative, but its formation from codeine by the follow-ing series of teactions :HaC18H2103N 3 C,,H&N 3 CI8H2,O2NC1 -- (electrolytic) +-Codeine.Dihydr oc odeine . C hlor odih ydroco di de .HC18H2302N 55 C18H2502N3Dihydrodeoxy- a-Tetr ahydro -codeine. deoxycodeine.76 M. Freund, W. W. Melber, and E. Schlesinger, J . p ~ . Chem., 1920, [ii],101, 1 ; A., i, 757ORGANIC CHEMISTRY. 125leaves no doubt as: to its composition. The absorption by deoxy-codeine of two molecular proportions of hydrogen in the presence ofpalladium is equally conclusive in respect of the P-compound. Ofthe two formulae current for codeine, the first (I) 76 affords noCH2 C*2(1.1 (11.1explanation of the isomerism, but according t o the second (11) 77the changes may be represented in the following way:CH CH CHM e O d N C HHO*C Ii If-c=2 CH, CH,Deoxycodeine.Both the tetrahydro-derivatives contain phenolic hydroxyl groups,but it is to be noted that there is a t present no evidence whichpermits a decision as t o which of the two formulae is to be attributedt o either compound.CH2Pyrrolidine B Ilcaloids.Cuskhygrine, to which the formula (I) was assigned78 on thegrounds of its empirical composition and its oxidation t o hygricacid ( A ) , , is in reality aydi-N~methyl42-pyrrolidylpropan-/3-one(II).7Q Its asymmetry follows from the formation of two distinct76 L.Knorr and H. Horlein, Ber., 1907, 40, 3341 ; A., 1907, i, 789; compare77 M. Freud and E. Speyer, ibid., 1916, 49, 1287; A., 1916, i, 738.78 C. Liebermann and G. Cybulski, ibid., 1895,28, 585 ; A., 1895, i, 310.7O K. Hess and H. Fink, ibid., 1920, 53, [B], 781 ; A., i, 497.J. vonBraun, Ber., 1914,47, 2312; A., 1914, i, 1138126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hydrazones, which are notable as the first examples of their kind,and are reduced by sodium ethoxide respectively t o di-N-methyl-2-CH, CH*CH,*CO*CM,*CH982-QH2 y " 2 - g\/NMe\/NMe(1.17H2-51H, YH2-5lH2 Ffi,-CH,CH, CH-QH-CH CH, CH, bH*CO,H\/NMe\/ COMe \/NMe N Me( 11.1 ( A . )pyrrolidylmethane (IV) and aa-di-,nJ-methyl-2-pyrrolidylpropane(V). The alkaloid does not respond to the usual tests for theCH, CH*$?H.CH CH, a-form CH, CH-QH-- CH, CH,7H2-FH2 $!H2-7H2 Q"2-QH2 C.'H2-QHf- \/ MeC:N*NH, \y$lH,-YH, $!H,-FH,p-form CH, CH*CH,*CH CH,N N eNMe N Me N Me NMe \/ Et \/(V-1\/NMe\/ -+(IV.1*CHgCO* grouping, but absorbs six molecular proportions of nitricoxide in the presence of sodium ethoxide. This reaction has notbeen utilised since its discoveryF0 but promises to be specially valu-able in such cases in that it permits the rupture of the moleculeby a smooth alkaline hydrolysis into simpler recognisable fragments.I n the present instance there are thus obtained methylenediisonitro-amine, N-methyl-2-pyrrolid ylacetic acid, and a mixture of unsatur-ated, more or less completely demethylated, bases of the type (VI),which by reduction and re-methylation give the above di-N-methyl-2-pyrrolidylmethane as sole product :9H2-7H2 T,O,H FH2-$!H,CH, CH--C--- CH CH,\Ale YO NMeI \/CH(N202W2f?H,-?H, 9H,-QH2 QH,-QH1CH, CH2(N202H)2 -I- CH, CH*CH,*CO,H -t CH, CH*CH:C\/NMe\/NMe\/NMe(VIP)W. Traube, Annalen, 1898, 300, 81 ; A,, 1898, i, 349ORGANIC CHEMISTRY. 127By the action of potassium hydroxide, cuskhygrine is converted intohygrine. It is suggested that a similar reaction may occur innature, and further that the carboxyl group of ecgonine mayrepresent an oxidised pyrrolidine nucleus of cuskhygrine.A reaction 81 which may well render the synthesis of cocaine andrelated compounds a commercial possibility consists in the applica-tion of the Dieckmann reaction to diethyl N-methyl-2 : 5-pyrrolidyl-diacetate, which is obtained by the action of methylamine ondiethyl succinyldiacetate. The condensation product thus obtainedis then reduced in glacial acetic acid solution by hydrogen in thepresence of platinum :CH:C*CH,*CO,Et~H2*C0*CH2*C02Et + CH,.NH, ---+ I h M e --.+H, -CO*CH2*C02Et ICH :C*CH,*CO,EtCH,*CR*CH2*C0,Et CH,*CH--CH*CO,Et 1 &Me ---+ I h e 60CH,*C'H*CH,*CO,Et UH2*CH--C'H, I I IThe ethyl tropinonecarboxylate produced may be reduced electro-lytioally or by sodium amalgam to the ethyl ester of r-ecgonine.The constitution of scopolamine and scopoline has now beendetermined. As scopoline was known to be an internal ether,from which hydroscopoline (1 : Zdihydroxytropan) ,82 A , was4 5 6CH2-CHa-CH,~ I H ~ N M ~ ~ H 7derived by rupture of the etheric linkage 83 through the addition oftwo hydrogen atoms, it only remained to determine which of theother atoms of t,he molecule is involved in the oxide ring. Theremarkable results of the degradation of scopoline by exhaustivemethylation permit a decision on this point.84 Although the distil-lation of scopoline methohydroxide under ordinary pressure resultsin profound decomposition,~5 under diminished pressure satisfactoryR. Willstatter, D.R.-P. 302401 ; A . , i, 680.E. Schmidt, Apoth. Zeit., 1902, 17, 592; A , , 19C3, i, 51.W. Luboldt, Arch. Phamn., 1898, 236, 26; A . , 1898, i, 499; E. Schmidt,82 Ann. Report8, 1918,15, 112.84 K. Hess, Ber., 1919, 52, [B], 1947 ; A., i, 81.Arch. Pharm,., 1905,243, 666; A., 1906, i, 103128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.results are obtained. I n place of the expected product, however, anisomeric, doubly unsahurated tertiary base, t)-demethylscopoline(11), is obtained. Tbe crucial result follows from the attempt todegrade this compound by exhaustive methylation, and may beconsidered in the following manner, which differs somewhat fromthat in the original paper. The product has a molecular formulagreater by one methylene group than that of qdemethylscopoline,due to the presence of a methoxy-group. The double bonds presenthave no influence on the result, because the product gives a tetra-hydro-derivative (IV), which is identical with that similarlyobtained from tetrahydro-$-demethylscopoline (V). Although afree hydroxyl group is no longer present, it cannot be assumed thatdirect methylation of the hydroxyl group in qdemethylscopolinehas occurred under such conditions. Hence the oxygen atom of theetheric linkage must have been methylated as the result of aprofound molecular rearrangement, the product therefore beingcalled O-methyliso-t)-demethylscopoliue (111). Such a change, how-ever, can only be adequately explained by assuming that thedimethylamino-group of t)-demethylscopoline is attached to one ofthe carbon atoms carrying the etheric linkage, which is destroyedso easily. This atom must therefore be 3- or 7- of the tropine ring.Assuming that the other carbon atom involved in the ether struc-ture is that in position 2, the former is excluded because it wouldinvolve the initial formation of a double bond in the originaldegradation of iV-methylscopoline either in the 1 : 7- or the 6 : 7-posi-tions. Of these, the first would represent the formation of theenolic form of a ketone, which is not observed, and the secondsupplies no explanation of the instability of the initial product andits rearrangbment to a doubly unsaturated compound. This, how-ever, is at once forthcoming on the assumption that the dimethyl-amino-group of $-demethylscopoline is attached to the 7-carbonatom, as will be seen from the scheme on p. 129. The formulafor scopoline is therefore represented by (I), whilst that forscopolamine is (VI).One of the two quaternary carbon atoms is seen to be responsiblefor each of the rearrangements. It is noteworthy that; bothO-methyliso-rl/-demethylscopoline and its tetrahydro-derivative arerecovered unchanged when the attempt is made to degrade themfurther by exhaustive methylation.The results of this investigation are an excellent illustration ofthe valuable information as to the factors which modify thestability of cyclic compounds to be derived from a study of naturaORGANIC CHEMISTRY. 129+CH,*CH;CTT2 CH,*CH,*CH,CH*NMe*CCH-- CH*O*CO*CHPh* CIJ,*OHIk0’lCH, C*NMe,+CH--CH*OHI I1 / 0 4(VI.) (V.)products-made up as they often are of structures not obtainablein the laboratory.J. KENNER.REP.-VOL. XVII.

ISSN:0365-6217    

DOI:10.1039/AR9201700052

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ANALIYTICAL CHEMISTRY.THE contributions to this branch of chemistry have been of amuch more varied character during the past year than has beenthe case during the preceding five years. America has continuedto show the greatest activity in this respect, whilst the conditionsin this anld other countries more seriously affected by the war havenot yet become normal.The main material difficulties in the way of analytical workhave been the lack of an adequate supply of suitable glassapparatus and the continued shortage of platinum. Furtherdevices have, therefore, been proposed t o obviate the use of thatmeta1.l For example, i t has been shown that for certain quan-titative estimations, such as the analysis of chrome iron ore,platinum basins may be replaced by lead basins,2 whilst iron basinsare suitabla for sulphide fusions.3 An efficient substitute forplatinum wire for flame tests may be prepared from a strip ofrolled filter paper,* or from the “ lead” OP a black-lead pencil.6Physical Methods.A new form of viscosimeter of the capillary type has beendevised. The oil or other liquid is forced up into the tube by thecompression of a bulb, the temperature brought to a definite pointby means of a thermostatic jacket, and the time required for theliquid to fall between given points is noted.The absolute vicosityis then calculated by means of the formula: q = K d t , where Rrepresents a constant of the apparatus, d the specific gravity ofthe liquid, and t the time in seconds.6The errors associated with the falling sphere type of viscosi-meter have been taken into consideration in a new instrument,Compare Ann.Reports, 1918, 15, 118 ; 1919, 16, 127.C. Hutter, Zeitsch. angew. Chem., 1919, 32, 380; A., ii, 189.H. Sertz, ibid., 1920, 33, i, 156.* A. Ehringhaus, Centr. Min., 1919, 192; A., ii, 263.li C. C. Kiplinger, J . I n d . Eng. Chem., 1920, 12, 500; A., ii, 381.G. Baume and H. Vigneron, Ann. China. anal., 1919, [ii], 1, 379 ; A., ii, 92.13ANALYTICAL CHEMISTRY. 131in which the steel ball is delivered into the centre of the tube,and corrections for the wall and end effects are applied, the resultbeing calculated into absolute viscosity by means of a modifica-tion of Stokes' equation.7Fischer's TJiscosimeter, which is particularly suitable for veryviscid liquids, consists essentially of an inner tube surrounded bya water jacket, resembling a vertical Liebig's condenser, throughwhich water a t a definite temperature is run.The viscosity ismeasured by the time required by a metal ball to fall betweentwo points on the inner tube.8A viscosimeter map be used for determining the density of aliquid of which only a few C.C. are available? the calculation beingmade by a combination of the formulae of Ostwald-Poiseuille andof Scarpa .loThe determination of the surface tension afforzds a means ofidentifying minute quantities of organic liquids. A capillary tubecontaining a short column of the liquid is turned1 until the lowermeniscus of the latter changes to a plane surface, and the angulardeviation of the tube from the vertical position is then read on aquadrant scale.The surface tension, T, is calculated by means ofthe usual formula: T=d x h x T x 98012 dynes per sq. cm.llFor estimating the acidity of liquids, the use of surface-activeindicators, as originally suggested by Traube and Somogyi,lZ isoften more convenient than the use of colour indicators.13 Byusing salts of alkaline nature, such as eucupine dihydrochloride, itis possible to titrate highly dissociated acids in the presence of aprimary phosphate,l4 whilst the relative alkalinity of the carbonatesand hydrogen carbonates of potassium, sodium, calcium, andmagnesium may be determined in an analogous manner.15A study of the soap-bubble method of determining the ignitiontemperature of gaseous mixtures 16 has shown that, even aftercareful standardisation of the coils, size of bubble, and otherdetails, the results cannot be depended on, even for comparativepurposes.17W.H. Gibson and (Miss) L. M. Jaaobs, T., 1920, 117, 473.Chern. Zeit., 1920, a, 622.W. Block, Zeitsch. angew. Chern., 1920, 33, 198 ; A., ii, 590.lo Qazzetta, 1910, 40, ii, 261 ; A., 1911, ii, 17.l1 C. C. Kiplinger, J. Amer. Chem. SOC., 1920, 42, 472; A., ii, 291.la Int. Zeitsch. phys.-chem. Biol., 1914, 1, 479 ; A., 1916, ii, 101.W. Windisch and W. Dietrich, Biochem. Zeitsch., 1919, 100, 130; A.,l4 Ibid., 136 ; A., ii, 706. l6 Tbid., 101, 82 ; A., ii, 707.16 J. W. McDavid, T., 1917, 111, 1003.l 7 A. G. White and T.W. Price, ibid., 1919, 115, 1248.ii, 48.F 132 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The melting-point curves obtained with binary and ternarymixtures of nitronaphthalenes may be used in the analysis of theindustrial products of nitration. The simultaneous presence ofmono- and tri-nitronaphthalene is indicated by points of arrest inthe cooling curves.IS Even when the melting point of the puresubstance is not known, the freezing-point curve affords an indica-tion of the amount of impurity present.19A new physico-chemical method of examining double salts hasbeen based on the measurement of the temperature produced onmixing the solutions with a constant liquid, such as phenol. Whena double salt is in solution, there is a variable difference betweenthe observed and calculated results.20Turning to optical methods, it has been shown that the ion con-tent of an aqueous solution of salts may be calculated from therefractive indices of the liquid before and after precipitation ofone of the component sa1ts.nSmall amounts of lead in copper may be estimated spectroscopic-aIly,22 the time required for the bright lead line (405-8pp) underconstant conditions being noted.Another application of spectro-photometry is in the analysis of colourless organic compounds,which f o r this purpose are converted into colourd compounds.23Reference may also be made to a new form of nephelometer24and to a photographic t'urbidimeter, in which one beam of lightis passed through the column of suspended substance and a secondbeam of equal intensity through standardised glass disks.25 I nthe nephelometric estimation of chlorides, the intensity of theopalescence of the silver chloride suspension is increased andrendered more constant by heating the liquid to 40° after theprecipitation .26 The nephelometric values of cholesterol and thehigher fatty acids have been shown to be affected by hydrolysisand by the presence of other substances, which, by themselves, donot produce turbidity.27The comparison of the fluorescence produced by ultra-violet rays18 P.Pascal, Bull. SOC. chim., 1920, [iv], 27, 388 ; A., ii, 514.lS W. P. White, J . Physical Chem., 1920, 24, 393 ; A., ii, 529.a. R. Dubrisay, Compt. rend., 1920, 170, 1582 ; A., ii, 508.11 M.de Crinis, Zeitsch. physiol. Chem., 1920, 110, 254 ; A., ii, 700.Za C. W. Hill and G. P. Luckey, Trans. Amer. Electrochem. SOC., 1917, 32,23 W. E. Mathewson, J . Amer. Chem. SOC., 1920, 42, 1277; A., ii, 566.t4 C. Chheveau and R. Audubert, Compt. rend., 1920, 170, 728; A.,ZJ W. G. Bowers and J. Moyer, J . Biol. Chem., 1920, 42, 191 ; A., ii, 444.26 A. B. Lamb, P. W. Carleton, and W. B. Meldrum, J . Amer. Chem. SOC.,a7 F. A. Csonka, J . Biol. Chem., 1920, 41, 243 ; A., ii, 272.335 ; A., ii, 193.ii, 327.1920, 42, 251 ; A., ii, 383ANALYTICAL CHEMISTRY. 133on substances in the cylinders of a nephelometer affords a newmeans of quantitative analysis.28A physical method of identifying and determining the purity ofacids has been based on the observation of their dissociationconstant, which may be determined, for example, by comparing thechange of colour of the same indicator in the solution and in astandard solution of known hydrogen-ion concentration .2Q Asimple method of determining the ion concentration of ultra-filtrates and other solutions free from proteins is to add an ionforming a sparingly soluble salt with the ion in question, and tonote the limit of solubility, as indicated by the formation of amilky turbidity.I n the case of calcium, the method gives resultsaccurate within 2 t o 3 milligrams per litre.30A method of analysis by fractional distillation under a constantreduced pressure is useful for the separation of substances havingboiling points which are close together.The fractionation is con-tinued until the final fractions show, not only identical boilingpoints, but also agree in their other physical properties, such asdensity, refractive index, and viscosity.31Gas Analysis.Various instruments for the automatic analysis of gases or forthe detection of an individual constituent have been described.The katharometer, which is intended for the estimation of smallquantities of hydrogen in air, is based on the change in the electricalresistance of a platinum helix through the increase in temperaturecaused by surface combustion of the hydrogen.32 An analogousprinciple has been utilised in the estimation of carbon monoxidein air.33The thermal conductivity method can only be applied quanti-tatively when the probable identity and amounts of constituentslikely to be present in a gaseous mixture are known, but undersuch conditions it gives good results in many cases.3428 L.J . Desha, J . Amer. Chem. SOC., 1920, 42, 1350 ; A., ii, 552.2 9 I. M. Kolthoff, Pharm. Weekblad, 1920, 57, 514 ; A., ii, 628.30 R. Brinkman and (Miss) E. van Dam, Proc. K. Akad. Wetensck.3l C. Moureu, C. Dufraisse, and P. Robin, Bull. SOC. chim., 1920, [iv], 27,33 H. A. Dayncs and G. A. Shakespear, Proc. Roy. SOC., 1920, 97, [A],33 A. B. Lamb and A. T. Larson, J. Amer. Chem. SOC., 1919, 41, 1908;34 E. R. Weaver and P. E. Palmer, J . Ind. Eng. Chem., 1920, 12, 894 ;Amsterdam, 1920, 22, 762 ; A., ii, 510.523 ; A., ii, 562.273 ; A., ii, 503.A., ii, 126.A., ii, 701134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Another instrument which may be used for the estimation ofmall amounts of hydrogen or helium in air is the interferometer,which measures the difference in the refractivity of two gases.35A weighing burette for use in gas analysis has been devised, theweight of the gas and alterations in volume caused by the absorp-tion of the constituents being determined by weighing the quantityof mercury which is removed from, or introduced into, theburette.36 Improved modifications of Orsat’s apparatus have alsobeen described.373 88A source of error in the analysis of gases by fractional combus-tion with copper oxide is the dissociation of the latter, with theliberation of oxygen.This may be obviated by subsequently pass-ing the nitrogen repeatedly over the oxide a t a moderate redheat .39The use of an ammoniacal copper solution has several advantagesover alkaline pyrogallol as an absorbent for the estimation ofoxygen. If the usual ammonium carbonate solution be replacedby saturated ammonium chloride solution, the gas will be free fromcarbon dioxide derived from the reagent.40 On the other hand,when freshly prepared, i t may impart traces of ammonia to thegas, and cannot be used in the case of gases containing carbonmonoxide or acetylene.41For the estimation of the latter, good results may be obtained,under certain conditions, by the use of ammoniacal cuprouschloride solution as absorption reagent, the solution being thenacidified with acetic acid, and the cuprous acetylide separated and,estimated.42 Another suitable reagent for the absorption ofacetylene is a solution of mercuric cyanide in sodium hyaroxidesolution.This effects its separation from ethylene and benzenevapour. For the absorption of ethylene in the presence ofbenzene, a solution of mercuric nitrate in dilute nitric acidsaturated with sodium nitrate may be used.43 Ilosvay’s reagent d485 J. C. McLennan and R. T. Elworthy, Trans. Roy. SOC. Canada, 1919,13, [iii], 19 ; A., ii, 508.su E. R. Weaver and P. G. Ledig, J . Amer. Chem. Soc., 1920, 42, 1177 ;A., ii, 602.87 T. B. Smith, Bas World, 1919, 71, 379 ; A., ii, 263.s8 G. W. Jones and F. R. Neumeister, Chem. and Met. Eng., 1919, 21,89 E. Ott, J .Gasbeleucht., 1919, 62, 89 ; A., ii, 52.40 W. Haehnel and M. Mugdan, Zeitsch. angew. Chem., 1920, 33, 35 ; A.,41 W. L. Badger, J. I n d . Eng. Chem., 1920, 12, 161 ; A., ii, 264.42 J. A. Muller, Bull. SOC. chim., 1920, [iv], 27, 69 ; A., ii, 198.734 ; A., ii, 119.ii, 191.W. D. Treadwell and F. A. Trtuber, HeZu. Chim. Acta, 1919, 2, 601 ;A., ii, 61. u Ber., 1899, 32, 2697 ; A., 1900, ii, 52ANALYTICAL CHEMISTRY. 135removes acetylene quantitatively from coal gas or air, and goodresults may be obtained by igniting the precipitate with nitricacid and weighing the copper oxide. Hydrogen sulphide must notbe present, and in the case of air containing not more than 0.04 percent. of acetylene, about 5 per cent. of carbon dioxide must beadded to prevent oxidation.45 Methods depending on the reactionof acetylene with silver nitrate, and titrattion of the liberated nitricacid, are inaccurate, owing to the impossibility of controlling theconditions of the reaction.Good, results may be obtained, how-ever, by causing the copper acetylide, separated with Ilosvay’sreagent, to react with a sulphuric acid solution of ferric sulphate,and titrating the resulting ferrous sulphate.46A satisfactory reagent for the absorption of carbon monoxidemay be prepared by reducing cupric chloride in acid solution bymeans of stannous chloride. The presence of a slight excess ofthe latter prevents oxidation by the air, and the reagent may berenewed by expelling the absorbed gas a t 60-70O.47A method of detecting anad estimating traces of Bp’-dichlorodi-ethyl sulphide (mustard gas) in air has been based on its reducingaction on a solution of selenious acid in sulphuric acid,, the amountof the orange-red suspension of selenium being estimated bynephelometric comparison with standard suspensions.Theselenious reagent also reacts in the same way with arsines and:other toxic gases.48A g r i d tural A naly sis.There has been a considerable amount of investigation as to themost suitable methods of estimating the acidity and the limerequirement of soils. Extraction of an acid soil with potassiumnitrate solution, as in the method of Hopkins and Pettit, has beenshown to give the same results as extraction with equivalent solu-tions of potassium chloride, sodium nitrate, sodium chloride, orcalcium chloride, whilst variations in the temperature between2 5 O and 90° do not affect the acidity of the extract.There islittle, if any, exchange of acid radicles during the extraction.4945 H. Arnold, E. Mollney, andF. Zimmermann, Bey., 1920, 53, [B], 1034 ;IS R. WillstBtter and E. Maschmann, ibid., 939 ; A., ii, 514.47 F. C. Krauskopf and L. H. Purdy, J . Ind. Eng. Chem., 1920, 12, 168 ;46 M. Yablik, G. St. J. Perrott, and N. H. Furman, J . Amer. Chem. SOC.,49 H. G. Knight, J . I n d . Eng. Chem., 1920, 12, 340; A., i, 468.A . , ii, 613.A., ii, 267.1920, 42, 266 ; A., ii, 272136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.For estimating the lime requirement, the vacuum method 50 givestrustworthy results agreeing with those obtained by the use of ahydrogen electrode after a specified period of shaking, whilst inthe case of limed soils the reduction in the acidity is best ascer-tained by the hydrogen electrode method or the Hopkins method.51The method of estimating the acidity or alkalinity of a soil interms of P H 5 2 has been adapted for use in field tests, and a tablehas been constructed showing the reactions of the soil correspond-ing with the colour changes of a series of indicators, each of whichoverlaps the next in the scale.53For the estimation of the total calcium in soils, a method hasbeen devised in which the precipitation with ammonia, and con-sequent occlusion of calcium in the precipitate, are eliminated.The precipitation is effected by adding solid ammonium oxalate tothe boiling solution, which has been rendered first just alkalinewith ammonia, and then just acid with hydrochloric acid, andmanganese is subsequently separated from the precipitatedoxalate.54 I n an investigation of ten different methods of estim-ating calcium in calcite, the most accurate results were obtainedby precipitation as calcium oxalate and weighing as calcium oxide,by precipitation as oxalate from a slightly acid solution, anmd bythe residual titration method.55The small amounts of manganese in plant ashes and similar pro-ducts can only be estimated colorimetrically.Of the differentmethods suggested, only that of Marshall56 has been found to givetrustworthy results.57 In that method, the manganese is oxidised,to permanganate by means of potassium persulphate.Theinfluence of various factors on the estimation of chlorides in soilhas been studied, and i t has been shown that Volhard’s methodgives more accurate and concordant results than Mohr’s method.58For estimating carbonates in limestones, marl, and soil, themethod of Van Slyke 59 is the most suitable for substances poor in5o J. W. Ames and C. J. Schollenberger, J . Ind. Eng. Chem., 1916, 8, 243;51 H. G. Knight, ibid., 1920, 12, 457, 559 ; A., i, 587 ; ii, 557.52 E. T. Wherry, J . Washington Acad. Sci., 1919, 9, 305; A., 1919,63 Ibid., 1920, 10, 217 ; A., ii, 400.0. M. Shedd, Soil Sci., 1920, 10, 1 ; A., ii, 636.66 G. E. &we, Chern. News, 1920, 121, 53; A., ii, 557.6Q Ibid., 1901, 83, 76; A., 1901, ii, 350.67 D.H. Wester, Rec. true. chirn., 1920, 39, 414 ; A., ii, 451.5a C. T. Hirst and J. E. Greaves, Soil Sci., 1920, 9, 41 ; A., ii, 384.59 J . Biol. Chem., 1918, 36, 351; A., 1919, ii, 78; compare Ann. Reports,A., 1916, i, 459.i, 428.1919, 16, 142ANALYTICAL CHEMISTRY. 137magnesium carbonate, whilst in other cases Van Slyke's gasometricmethod 60 gives more accurate results.61A method for the approximate estimation of phytin in plantextracts has been based on its precipitation in the presence ofinorganic phosphates by an acetic acid solution of copper acetateof definite concentration, but the amounts of phytin precipitatedvary with the nature of the plant.62Organic Analysis.Qualitative .-Formaldehyde gives colorations, which are notalways distinctive of the aldehyde, with certain aromatic com-pounds, such as pyrogallol, P-naphthol, and salicylic acid, andthese chromatic reactions may sometimes be used as tests ofidentity.63 Another reagent which gives distinctive colorationswith polyhydroxyphenols and other compounds of a phenoliccharacter is sodium p-toluenedisulphochloroamide in neutral oralkaline solution, but the tests must be made under definite con-ditions as to the proportions of reacting substances and thetemperature.64Most of the tests for methyl alcohol are based on its conversioninto formaldehyde, which is then identified either by chromaticreactions or by the formation of crystalline derivatives.Thesemethods have been critically examined and their relative trust-worthiness determined.Of the direct tests, all of which require aconsiderable proportion of methyl alcohol, that of Vivario,65 inwhich the methyl alcohol is converted into potassium cyanide, givesvery good results.66A test to distinguish between methyl and ethyl alcohols hasbeen based on the solubility of qrystallised copper sulphate in theformer,67 but is untrustworthy in the case of mixtures of the diluteal.cohols.68 Lieben's reaction for iodoform has been modified so asto afford a sensitive test for traces of ethyl alcohol.69A specific reaction for acetoacetic acid and its esters has been8 o J . Biol. Chem., 1017, 30, 347; A., 1917, ii, 422.C. S. Robinson, Soil Sci., 1920, 10, 41 ; A., ii, 635.6a A.Rippel, Biochem. Zeitsch., 1920, 103, 163; A., ii, 518.63 A. Rossi, Boll. Chim. farm., 1919, 58, 265 ; A., ii, 63.1 3 ~ A. Berthelot and M. Michel, Bull. Sci. Phurmacol., 1919, 26, 401 ; A . ,65 J . Pharm. Chim., 1914, [vii], 10, 145; A., 1914, ii, 780.66 A. 0. Gettler, J. Biol. Chem., 1920, 42, 311; A., ii, 562.O 7 Pannwitz, Pharm. 2entr.-h., 1919, 60, 441 ; A., ii, 62.6 8 T. Sabalitschka, ibid., 1920, 61, 78 ; A., ii, 271.69 R. Kunz, Zeitsch. anal. Chem., 1920, 59, 302 ; A., ii, 711.ii, 336.I?138 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.based on its conldensation in hydrochloric acid solution t o formP-methylumbellif erone, which in alkaline solution shows an intenseblue fluorescence.70From a study of various reactions for the identification of tracesof hydrocyanic acid, the conclusion has been drawn that the ferro-cyanide test is the most characteristic.71 The Prussian-blue testgives a reaction a t a dilution of about 1 : 17 x 104 with hydrocyanicacid, whilst the Schonbein test, which is not distinctive, gives areaction a t 1 : 43 x 106 in the light and a t 1 : 55 x 106 in the dark.72A test paper impregnated with a solution of o-tolidine, copperacetate, and dilute acetic acid is capable of detecting one part ofhydrocyanic acid in two million parts of air.73In the colour reaction with manganese salts for ~ x a l a t e s , ~ ~sufficient oxidation is produced, by agitating the hot solution witha little alkali hydroxide.75 Oxalic acid! may be distinguished fromtartaric and lactic acids by giving a violet coloration when heatedwith sulphurk acid and resorcinol.76 If the test be applied as azone reaction, a blue ring is formed a t the junction of the liquids.77A biochemical method of detecting dextrose in the presence ofother sugars, such as mannose, lzevulose, or arabinose, has beenbased on its conversion, in 70 per cent.methyl alcohol solution,by emulsin into P-methylglucoside, which may be identified incrystalline form.78 Of various tests recommended for the detec-tion of dextrose in urine, Fehling's test is the most sensitive, beingcapable of detecting 0.00125 per cent .79 Traces of acetylmethyl-carbinol formed in the butylene-glycollic fermentation of sugarsmay be identified by oxidising the carbinol to diacetyl, which isthen distilled, and identified by precipitation as nickel dimethyl-glyoxime.80A very sensitive test for benzoic acid or for substances such ascocaine, which contain a benzoyl group, or which, like atropine,yield benzoic acid on oxidation, has been based1 on the diazotisa-tion of the aminobenzoic acids produced on nitration and reduc-7 0 V.Arreguine and E. D. Garcia, Ann. Chim. anal., 1920, [ii], 2, 36 ; A.,ii, 273.72 J. B. Ekeley and I. C. Macy, Proc. Colorado Sci. SOC., 1919, 11, 269;A., ii, 202.7l L. Chelle, ibid.. 21 ; A., ii, 202.J. Moir, J. S. African Assoc. Anal. Chem., 1920, 3, 16 ; A., ii, 715.74 V. Mwri, Boll. chim. farm., 1917, 56, 377 ; A., 1917, ii, 511.76 H.Cmon and D. Raquet, Ann. Chim. alzaZ., 1919, [ii], 1, 205; A., 1919,7 6 K. Brauer, Chem. Zeit., 1920, 441, 494; A., ii, 517.7 7 L. H. Chernoff, J. Amer. Chem. SOC., 1920, 42, 1784; A., ii, 712.78 E. Bourquelot and M. Bridel, Compt. rend., 1920, 170, 631 ; A., ii, 337.7 9 G. E. *we, Amer. J. Pharm., 1919, 91, 717 ; A., ii, 132.ii, 438.M. Lemoigne, Compt. rend., 1920, 170, 131 ; A., ii, 198ANALYTICAL CHEMISTRY. 139tion, and the formation of an orange-red precipitate on treatingthe diazo-compounds with an ammoniacal solution of &naphthol .S1The behaviour of guaiacol with an oxydase affords a means ofdistinguishing it from creosote, the former giving a yellow color-ation immediately, whilst the latter is colourless a t first and thenshows a slight violet tint.s2A new colour reaction for quinine, which takes place on theaddition of pyridine in the presence of chlorine water, distinguishesthe alkaloid from quinidine and euquinidine.The colour changesfrom yellow to rose, and finally t o purplish-red.83A sensitive and characteristic test for strychnine consists intreatment of the alkaloid salt solution with hydrochloric acid andzinc amalgam, and finally with potassium ferricyanide. I n thepresence of quantities down t o 0.001 milligram of strychnine, apink to rose-red coloration is obtained .83 Various colour reactionsof emetine have also been described.84Pyrrole reacts with p-dimethylaminobenzaldehyde in ananalogous manner to indole, and this must, be borne in mind whenapplying Ehrlich's test .85Quantitative.-A new form of absorption apparatus forelementary analysis has been 'devised, in which the carbon dioxideis absorbed by potassium hydroxide solution, and special precau-tions are used in drying the gas.86 Certain organic substances,such as methyl esters and chloro-compounds, may be quantitativelyoxidised by means of a mixture of sulphuric and chromic acids, thechlorine in the latter compounds being retained by an amalgamatedcopper spiral preceding the burette in which the carbon dioxide ismeasured .87 Another new method of estimating carbon andhydrogen in organic compounds is based on their combustion incontact with platinum and cerium dioxide.88Fusion with an alkaline mixture containing alkali nitrates, pre-cipitation of the carbonate as calcium carbonate from a solution ofthe fused mass, and titration of the washed precipitate with hydro-chloric acid, has been recommended for the estimation of carbon.89A simple and rapid method of estimating halogens in organiccompounds is to volatilise the substance with air through a quartzM.Guerbet, Compt. rend., 1920, 171, 40 ; A., ii, 517.D. Ganassini, Arch. ital. biol., 1919, 69, 7 3 : A., ii, 339.813 H. E. Buc, J . Assoc. Off. Agric. Chem., 1919, 3, 193; A., ii, 397.84 A. Lahille, Arch. m a . exp., 27, 336 ; A., ii, 134.E. Salkowski, Riochem. Zeitsch., 1920, 103, 185 ; A., ii, 566.e6 F. Friedrichs, Zeitsch. angew. Chem., 1919, 32, 388 ; A., ii, 192.87 J. Guyot and L. J. Simon, Cornpt. rend., 1920, 170, 734 ; A., ii, 332.8Q L.Lescceur, J . Pharm. Chim., 1920, [vii], 21, 267 ; A., ii, 332.I<. Sumikura, J . Tokyo Chem. Soc., 1919, 40, 593 ; A., ii, 126.F* 140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tube heated a t 900-1000°, to absorb the products of combustionin sodium hydroxide solution containing sodium sulphite, and,after oxidising the excess of the latter with potassium perman-ganate, t o estimate the halogen by Volhard's pr0cess.mIn using Kjeldahl's process for the estimation of nitrogen inaromatic nitro-compounds, it should be noted that accurate remltsmay be obtained with ortho-compounds, but that those given bymeta- and para-derivatives will be much too low.91Estimation of nitro-groups by reduction with stannous chlorideand titration of the excess of the reagent with iodine gives too lowresults with mononitrotoluenes, owing t o the formation of p-chloro-toluidines, whilst the use of titanous chloride gives resuTts about3 per cent.too low in the case of o-nitrotoluene.92 The low resultsgiven by a-nitronaphthalene and similar compounds may beobviated by substituting titanous sulphate for titanous chloride,and thus preventing chlorination.93 Diazo-compounds, such asbenzenediazonium chloride, may be titrated in hydrochloric acidsolution by means of titanous chloride, with suitable indicators.94A method for the estimation of methyl alcohol has been basedon its oxidation with sulphuric acid and potassium dichromate, andgravimetric estimation of the carbon dioxide produced or volu-metric estimation of the excess of dichromate.95 I n anothermethod, the methyl alcohol is oxidised by means of ammoniumpersulphate, and the resulting formaldehyde estimated colori-met r ically.96Por the estimation of ethylene glycol, oxidation with potassiumdichromate and! sulphuric acid, as in glycerol analysis, gives trust-worthy results, but the acetin method is not applicable to dilutesolutions of the gly00l.~~An apparatus for estimating the carbon dioxisde formed in thefermentation of sugars has been devised, and the method has beenshown to be applicable to the differentiation of yeasts and enzymesby fermentation with appropriate sugars.98W. A.van Winkle and G. McP. Smith, J. Arner. Chem. SOC., 1920, 42,333 ; A., ii, 328.91 B.M. Margosches and E. Vogel, Ber., 1919, 52, [B], 1992 ; A., ii, 50.ga D. Florentin and H. Vandenberghe, BUZZ. SOC. chim., 1920, [iv], 27, 158 ;93 T. Callan, J. A. R. Henderson, and N. Strafford, J. Soc. C'hem. Ind., 1920,94 E. Knecht and L. Thompson, J. sbc. Dyers and Col., 1920, 36, 215;95 A. Heiduschka and L. Wolff, Pharm. Zen&.-h., 1920, 61, 361 ; A . , ii, 515.96 S. B. Schryver and C. C. Wood, Analyst, 1920, 45, 164; A., ii, 393.97 €3. Miiller, Ghem. Zeit., 1920, 44, 513 ; A., ii, 515.98 A. Slator, J. SOC. Chem. I d . , 1920, 39, 1 4 9 ~ ; A., ii, 448.A., ii, 271.39, 861. ; A., ii, 331.A., ii, 647ANALYTICAL CHEMISTRY. 141Sucrose may be accurately estimated by a cryoscopic method.99For the estimation of sugars by inversion, chemical catalysts, suchas benzenesulphonic acid, have advantages over enzymes.1 Theoptical rotation of laevulose is destroyed by heating the sugar forseven hours with dilute hydrochloric acid, whereas that of dextroseis not affected.This has been made the basis of a method ofestimating these sugars.2 I n the case of fruit juices, however, themost trustworthy method is to calculate the proportions of therespective sugars from the cupric-reducing power and the iodinevalue, the latter being characteristic for each sugar.3 Anothermethod of estimating dextrose has been based on the action ofpotassium cyanide for two days a t 20°, and estimation of theexcess of the reagent, or measurement in the change in rotation ofthe d e ~ t r o s e .~A modification of the phenylhydrazine method for estimatingpentosans consists in distilling the substance with sulphuric acidand estimating the furfuraldehyde by precipitation as hydrazone,and determination of the excess of phenylhydrazine in the filtrate.5The coloration given by phenol when heated with Millon'sreagent and nitric acid affords a means for its colorimetric estim-ation in the presence of other phenols.6 Another method ofestimating phenol is based on its titration with a solution of adiazonium compound, hydroxyazo-compounds being formed in thereaction.7The conditions under which phenolphthalein combines quanti-tatively with iodine to form tetraiodophenolphthalein have beeninvestigated, and a gravimetric method based on them.8Silico- and phospho-tungstic acids are suitable reagents for thegravimetric and volumetric estimation of alkaloids under specifiedconditions, phosphotungstic acid being preferable in the case ofaconitine and n i ~ o t i n e .~ For the quantitative separation ofstrychnine from quinine, advantage has been taken of the fact thatthe former is only very slightly soluble in ethyl ether, and is leftH. H. Dixon and T. G. Mason, Sci. Proc. Roy. Dubl. SOC., 1920, 16, 1 ;A., ii, 395.E. Hildt, Ann. Chirn. anal., 1920, [ii], 2, 103 : A., ii, 395.F. Lucius, Zeitsch. Nahr. Benusmn., 1919, 38, 177 ; A., ii, 132.8 (Miss) H. M. Judd, Biochem. J . , 1920, 14, 255 ; A., ii, 395.J. Bougault and J. Perrier, C m p t . rend., 1920. 170, 1395 ; A., ii, 452.P.Menad and C. T. Dowell, J . I n d . Emg. Chem., 1919, 11, 1024; A.,ii, 200.6 R. M. Chapin, ibid., 1920, 12, 771 ; A., ii, 645.8 S. Palkin, ibid., 1920, 12, 766: A., ii, 643.R. M. Chapin, ibid., 568 ; A., ii, 563.A. Heiduschka and L. Wolff, Schweiz-Apoth. Zeit., 1930, 58, 213, 229 ;A., ii, 780142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in the aqueous solution on extraction with ether in the presenceof ammonia.1° Reference may also be made to a method of estim-ating codeine by treatment of the plant extract with calcium hydr-oxide, and extraction of the filtrate with toluene.11Tyrosine cannot be estimated quantitatively in the products ofthe hydrolytes of proteins by the method of Folin and Denis,12 sincethe blue coloration is also given by tryptophan and othercompounds in the mixture.13It has been shown that the growth of yeast cells under specifiedconditions depends on the amount of so-called vitamins present,and a gravimetric method of estimating vitamins has been basedon this fact.14 The method has been found applicable to theestimation of the vitamin in f0od.15 On the other hand, the resultsof other experiments have indicated that the test is influenced byso many factors as t o have little, if any, value.leInorganic Analysis.Qualitative .-Sodium alizarinsulphonate has been proposed asa sensitive indicator for the titration of mineral acids, and has thefurther advantage that i t can be used both with ammonia andphosphoric acid.17Several new schemes for the separation of cations into groupshave been published.These include a modification of Petersen'smethod18 of separating the cations of the third and fourthgroups,1g and a new method for the separation of various metalsin the presence of phosphoric acid.20 The use of thioacetic acidhas been shown to offer several advantages over hydrogen sulphideas a reagent for the precipitation of the cations of Group II.21Sensitive tests for manganic, ceric, cobaltic, and thallic com-pounds have been based on the fact that they give intense bluecolorations with benzidine and other diphenyl derivatives.22lo A. R. Bliss, J. Amer. Pharm. ASSOC., 1919, 8, 804; A., ii, 276.11 H. E. Annett and H. Sen, Analyst, 1920, 125, 321 ; A., ii, 644.12 J. BioZ.Chem., 1912, 12, 245; A., 1912, ii, 1012.13 R. A. Gortner andG. E. Holm, J . Amer. Chem. Soc., 1920, 42, 1678;l4 R. J. Williams, J . Bid. Chem., 1920, 42, 259 ; A., ii, 648.l6 W. H. Eddy and H. C. Stevenson, ibid., 1920, 43, 295 ; A., ii, 716.l6 G. de P. Souza and E. V. McCollum, ibid., 1920, 44, 113; A., i, 919.W. Mestrezat, J . Pharm. Chim., 1920, [vii], 21, 185 ; A., ii, 263.Zeitsch. anorg. Chem., 1910, 67, 253 ; A., 1920, ii, 654.P. de Pauw, Chem. Wee,kblad, 1920, 17, 191 ; A., ii, 451.N. Alvarez, BoE. minero POC. nac. min. Chile, 1919, 31, 181 ; A., ii, 381.A., ii, 643.2Q H. Remy, Zeitsch. anal. Chem., 1919, 58, 385 ; A., ii, 186.22 F. Feigl, Chem. Zeit., 1920, a, 689; A., ii, 710ANALYTICAL CHEMISTRY. 143Turning to the specific tests for individual substances, it hasbeen shown that iodic acid may be used as a distinctive micro-scopical reagent for the detection of ammonia, characteristiccrystals of ammonium iodate being formed.23The differences between the deposits formed by hydrogenarsenide, cacodylic acid, methylarsinic acid, and neosalvarsan inMarsh’s test have been studied, and i t has been found that theaddition of platinum chloride t o promote the evolution of hydrogenmay fix some of the arsenic in the flask.2* The best method ofdetecting arsenic in sulphur is by oxidation with bromine andnitric acid, and application of Gutzeit’s test to the product.25 Atest for salts of tin has been based on the insolubility of stannousor stannic iodide in sulphuric acid. The yellow precipitate maybe distinguished from the similar compound formed by arsenic bythe fact that it is soluble in dilute hydrochloric acid.The corre-sponding antimony salt is brick-red and flocculent.26 A distinctivetest for osmium tetroxide is afforded by the blue coloration whichit gives with pyrogallol, whilst the vapour may be identified bygiving a permanent stain, due to the reduced osmium, with aslightly greasy finger-print .27Xanthic acid may be used as a distinctive reagent for molyb-denum,2* but i t is essential that oxalates should not be present,whilst copper, cobalt, nickel, iron, and uranium interfere with thetest .29For the detection of traces of cobalt, the coloration given by0-nitroso-a-naphthol is much more sensitive than that obtainedwith a-nitroso-P-naphthol.30 Cobalt may be detected in thepresence of nickel by means of potassium xanthate.The xanthatesof both metals are precipitates, but the cobalt compound is in-soluble in ammonia, whereas the nickel compound dissolves,forming a blue solution.31Most cerous and ceric compounds give a bright blue colorationwhen moistened with a solution of benzidine in acetic acid, andthe reaction may be used for detecting cerium in the presence ofother metals of the ammonium sulphide group of rare earths, withthe exception of thalli~rn.3~t3 G. Denigbs, Compf. rend., 1920,171, 177 ; A., ii, 555.24 D. Ganassini, Boll. Chim. farm., 1919, 58, 395 ; A., ii, 51.25 H. S. Davis and M. D. Davis, J . Ind. Eng. Chem., 1920, 12, 479 ; A.,27 C.A. Mitchell, Analyst, 1920, 45, 125 ; A., ii, 335.28 S. L. Malowan, Zeitsch. anorg. Chem., 1919, 108, 73 ; A., ii, 59.29 J. Koppel, Clzem. Zed., 1919, 43, 777 ; A., ii. 58.30 I. Bellucci, Qazzetta, 1919, 49, ii, 294 ; A., ii, 194.31 L. Compin, Ann. Chim. anal., 1920, [ii], 2, 218 ; A., ii, 559.32 F. Feigl, Oesterr. Chern. Zeit., [ii], 22, 124 ; A., ii, 54.ii, 448. 26 A. Mazuir, Ann. Chim. anal., 1919, [ii], 2, 9 ; A., ii, 197144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Iodic acid has been found to be a useful microchemical reagentfor calcium, strontium, or barium, the distinctive forms of thecrystalline iodates being observed.33 It may also be used to dis-tinguish between the salts of barium and radium.34For the detection of magnesium, advantage has been taken ofthe fact that it gives a bluish-violet coloration with an alcoholicsolution of alkannin, the similar colorations given by strontiumand manganese being distinguished by their behaviour afteracidification .35The applicability and sensitiveness of various reactions forpotassium have been determined, and the most sensitive reagenthas been found to be sodium-bismuth thiosulphate, which iscapable of detecting 1 part in 57,000.36The colour changes which take place in the diphenylamine reac-tion for nitrates have been studied, and a sensitive modificationof the reagent devised for microchemical tests.37 A blue colorationmay be produced in the diphenylamine reagent by the presence offerric salts in the sulphuric acid. To prevent this, such acidshould be boiled, and cooled to reduce the ferric salts.38A sensitive test for nitrites in the presence of nitrates is theproduction of a red coloration on treating the solution successivelywith acetic acid, potassium oxalate solution, manganous sulphate,and hydrogen peroxide.39 For the detection of phosphates in thepresence of barium, a modification of Denigk’ strychnine-molybdate reagent is sensitive, but must be freshly ~repared.~OQuantitative.-It is in this branch of the subject that thegreatest activity has been shown, and the contributions to differentjournals have been so numerous that it has been necessary to selectonly the more important for mention in this Report.A method of using potassium chlorate as an original standardfor the titration of alkali has been described.The chlorate isreduced by means of sulphur dioxide, the excess of the latterremoved, and the sulphuric acid formed in the reduction titratedwith alkali-KC10, + 350, + 3H,O = 3H,S04 + KCl.41 Anothersuitable standard is potassium hydrogen phthalate, which containsG. DenigBs, Compt. rend., 1920, 170, 996 ; A., ii, 388.34 G. DenigBs, ibid., 1920, 171, 633 ; A., ii, 706.s5 F. Eisenlohr, Ber., 1920, 53, [B], 1476 ; A., ii, 708.s6 0. Lutz, Zeitsch. anal. Chem., 1920, 59, 145 ; A., ii, 509.37 E. M. Harvey, J . Amer. Chem. Soc., 1920, 42, 1245 ; A., ii, 504.3i3 F. Ham, Zeitsch. Nahr. Genusmn., 1920, 39, 355 ; A., ii, 555.39 P. H. Hermans, Pharm. Weekblad, 1920, 57, 4 6 2 ; A., ii, 448.40 L.DBbourdeaux, Bull. Sci. pharmacol., 1920, 27, 70 ; A , , ii, 505.41 H. B. van Valkenburgh, J . Amer. Chem. SOC., 1920, 42, 757; A.,ii. 387ANALYTICAL CHEMISTRY, 145no water of crystallisation and is not hygro~copic.4~ I n preparingthe salt, i t is advisable to crystallise i t above 20°, to prevent theformation of a more acid salt.43 A useful indicator for colouredliquids has been found in ferrous sulphide, the formation of whichis prevented by a slight trace of acid. A crystal of pure ferrousammonium sulphate is added to the solution, which is then treatedwith hydrogen sulphide, and titrated with alkali until a permanentblack coloration is obtained.44Various experiments have been made with salts of magnesium,zinc, mercury, and aluminium to determine the degree of accuracyobtainable in the acidimetric titration of the salts of heavy metalswhich form insoluble hydroxides.45I n the volumetric estimation of sulphates by oxidation ofbenzidine sulphate with potassium ~ermanganate,~~ it is essentialthat the solution from which the benzidine sulphate is precipitatedshould be free from organic matter, iron, heavy metals, nitrates,and phosphates.47A new volumetric reduction method with arsenic trioxide hasbeen devised, in which an oxidising agent, such as a chlorate orchromate, is treated with excess of arsenic trioxide in the presenceof hydrochloric acid, and the solution subsequently titrated withpotassium bromate solution.4*The con-ditions for the iodometric estimation of aci'ds, more especially weakacids, have been investigated, and the applicability of variousmethods has been determined .49 The direct estimation of chloricacid in a strongly acid medium gives too high results, owing tooxidation of hydrogen iodide, but Rupp's method50 is trust-worthy.51 For the iodometric estimation of arsenic acid, the react-ing mixture should be heated to looo and contain specified propor-tions of potassium iodide and hydrogen chl0ride.5~Stannous tin may be more accurately estimated by a volumetricmethod in an acid solution. Titration with standard iodine solu-Several new iodometric methods have been published.42 W.8. Hendrixson, J . Amer. Chem. SOC., 1920, 42, 724; A., ii, 382.43 F. D. Doclee, ibid., 1655 ; A., ii, 628.44 J.Houben, Ber., 1919, [B], 1613; A., ii, 53.45 I. M. Kolthoff, Zeitsch. anorg. Chem., 1920, 112, 172; A . , ii, 709.46 G. W. Raiziss and H. Dubin, J . Biol. Chem., 1914, 18, 297 ; A., 1914,47 P. L. Hibbard, So31 Sci., 1919, 8, 61 ; A., ii, 191.48 F. de Bacho, Annali Chim. Appl., 1919, 12, 153 ; A., ii, 188.49 I. M. Kolthoff, Pharm. Weekblad, 1920, 57, 53 ; &4., ii, 121.50 E. Rupp, Zeitsch. anal. Chem., 1917, 56, 580 ; A., 1918, ii, 125.51 I. M. Kolthoff, Pharm. Weekblad, 1919, 56, 460; A., ii, 190.62 P. Fleury, J . Pharm. Chim., 1920, [vii], 21, 385; A., ii, 448.ii, 671146 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion in the presence of hydrochloric acid is satisfactory in the caseof many compounds.53 The iodometric estimation of chromiumgives too high results, owing to the influence of atmospheric oxygenon the reaction.54To obtain accurate results in the iodometric estimation ofpotassium f erricyanide, the acid concentration must be keptsufficiently high and the time of the reaction restricted.55A new volumetric method of estimating nickel has been basedon the titration of the acid which is liberated in the reaction withdimethylglyoxime .56Further work on the use of organic solvents f o r the quantitativeseparation of metals has shown that the method of progressiveprecipitation previously described 57 is suitable for the separationof magnesium from sodium and potassium, the salts of the lattermetals being precipitated first by means of alcohol and ether.58New applications of the use of cupferron (the ammonium saltof nitrosophenylhydroxylamine) have been published.The reagentgives good results in the estimation of iron, copper, titanium,zirconium, thorium, and vanadium in the absence of certaininterfering substances, but in many cases offers no advantageover previous methods.59 It is most serviceable for theseparation of copper from arsenic, and especially from antimony.Like ccnitroso-&naphthol, it is a useful reagent for separatingelements into groups.60 I n neutral solution it gives precipitateswith all metals except the alkali metals, and the precipitates maybe separated into two groups by their behaviour towards chloro-form and1 dilute acilds.61 I f corrections for the solubility of theprecipitate be applied, iron may be accurately separated frommanganese by cupf erron.62 A trustworthy method has also beenworked out for the use of the reagent in the separation of tin andantimony.63A simple method of estimating mercury is to cause it to be6a J.G. F. Druce, Chem. News, 1920, 121, 173; A., ii, 710.5* 0. Meindl, Zeitsch. anal. Chem., 1919, 58, 629 ; A., ii, 390.56 I. M. Kolthoff, Pharm. Weekblad, 1919, 56, 1618; A., ii, 67.6t3 J. Holluta, Monatsh., 1919, 4-43? 281 ; A., ii, 57.57 S. Palkin, J. Amer. Chem. SOC., 1916, 38, 2326; A., 1917, ii, 43.&* Ibd., 1920, 42, 1618 ; A., ii, 637.G. E. F. Lundell and H. B. Knowles, J. Ind. Eng. Chem., 1920, 12,344 ; A., ii, 390.6o I. Bellucci and A. Chiucini, Gaxzetta, 1919, 49, ii, 187 ; A., ii, 54.V.Auger, Compt. rend., 1920, 170, 995 ; A., ii, 391.E. H. Archibald and R. V. Fulton, Trans. Roy. SOC. Canada, 1919, 13,[iii], 243 ; A., ii, 512.6* A. Kling and A. Lassieur, Compt. rend., 1920, 170, 1112 ; A., ii, 452ANALYTICAL CHEMISTRY. 147deposited on a coil of copper gauze, and to estimate the amountof the deposit by the loss in weight after heating the coil in acurrent of hydrogen .64Arsenic may be separated from antimony, tin, copper, lead,mercury, and iron by a modification of the distillation method,whilst antimony may be separated from tin by volatilisingantimony chloride a t 155-165O from solutions to which phosphoricacid has been added to render the tin non-volatile65 A modifi-cation of the Marsh-Berzelius test has been described in which thehydrogen arsenide is conducted over red-hot copper, which retainsthe arsenic as arsenides.The results are about 1.4% too low,possibly owing to retention of arsenic in the flask in the form of astable complex.66I n order to obtain a precipitate of secondary zirconium phos-phate of constant composition in the precipitation of zirconiumby the phosphate method, the solution should contain from 2 to 20per cent. of sulphuric acid, and an excess of diammonium hydrogenphosphate ten to one hundred times in excess of the theoreticalquantity should' be added.67 A new method, appliaable to zirconiaores, is to precipitate the zirconium with selenious acid, and toignite the basic selenite, which leaves a residue of zirconia.68The difficulty of precipitating molybdenum quantitatively assulphide may be obviated by having a sufficient quantity of formicacid in the solution, and seeing that the whole of the molybdenumis present as molybdate.69From a study of various methods of estimating uranium, theconclusion has been drawn that precipitation with ammoniumsulphide or with ammonia gives the most trustworthy results.I neither case, the precipitate leaves uranoso-uranic oxide on igni-tion .70 Precipitation of uranium as uranyl ammonium phosphateis also a good method, but has the drawback that the ignited uranylpyrophosphate rapidly absorbs moisture .71 For the estimation ofminute quantities of uranium, a colorimetric method has beenbased on the red coloration given by uranyl salts with sodiumsalicylate .7264 H.B. Gordon, Analyst, 1920, 45, 41 ; A., ii, 194.66 W. Strecker and A. Riedemann, BPr., 1919, 52, [B], 1935 ; A., ii, 51.G6 B. S. Evans, Analyst, 1920, 45, 8 ; A., ii, 125.G7 G. E. F. Lundell and H. B. Knowles, J. Amer. Chem. SOC., 1919, 41,6s M. S. Smith and C. James, ibid., 1920, 42, 1764; A., ii, 710.69 J. StGrba-Bohm and J. Vostfebal, Zeitsch. anorg. Chem., 1920, 110, 82 ;'O R. Schwarz, HeZv. Chim. Acta, 1920, 3, 330 ; A., ii, 391.71 C. A. Pierre, J. Ind. Eng. Chem., 1920, 12, 60 ; A., ii, 197.73 Muller, Chem. Zeit,, 1919, 43, 739 ; A., ii, 60.1801 ; A., ii, 60.A., ii, 335148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The perchlorate method for the estimation of potassium givesaccurate results under specified conditions.73 The methodpreviously described 74 is rendered more trustworthy by extractingthe sodium perchlorate with alcohol containing perchloric acid,instead of with a saturated solution of potassium perchlorate.75By using aniline perchlorate in place of perchloric acid, the processis rendered more rapid than any other method of estimatingpotassium.76 The proportion of potassium in the mixed precipitateof potassium and sodium cobaltinitrite may be calculated from agravimetric or electrolytic estimation of the cobalt.77 Anothermethod of estimating the proportions of the two metals in mixturesof the salts is to convert them into nitrates and determine themelting points.78Chromic acid liberates bromine quantitatively from bromides a tthe ordinary temperature, and the bromine may be removed byaspiration, whereas chlorides under the same conditions yield onlytraces of chlorine.A method of estimating bromine in mineralwaters has been based on these f a ~ t s . 7 ~The conditions for effecting the quantitative estimation of phos-phoric acid by precipitating and weighing it as ammoniumphosphomolybdate have been investigated, and a trustworthymethod devised. For the nephelometric estimation of traces ofphosphoric acid, the use of a reagent prepared by the interactionof strychnine sulphate and sodium molybdate gives excellentresults .SOElect roc h e mica1 A nal ysis.There have been relatively few contributions to gravimetricelectrolytic methods of analysis, but much work has been done inconnexion with the investigation of methods of electrometrictitration and their extension t o further substanoes.It has been shown that in many cases the end-point of a titra-tion is sharply indicated by measurement of the terminal voltagebetween two electrodes, one of which is immersed in the solution73 R.L. Morris, Analyst, 1920, 45, 349 ; A., ii, 707.74 G. P. Baxter and M. Kobayashi, J. Amer. Chem. SOC., 1917, 39, 249 ;75 G. P. Baxter and M. Kobayashi, ibid., 1920, 42, 735 ; A., ii, 385.76 S. B. Kuzirian, Proc. Iowa. Acad. h+ci., 1917, 24, 547 ; A., ii, 450.77 P. Wenger and C. HBmen, Ann. Chim. anal., 1920, [ii], 2, 198; A.,A., 1917, ii, 270.ii, 556.A.Quartaroli, Gazzetta, 1920, 50, ii, 64 ; A., ii, 635.7s W. F. Baughman and W. W. Skinner, J. I n d . Eng. Chem., 1919, 11,954 ; A., ii, 48.H. Kleinmrtnn, Biochem. Zeitsch., 1919, 99, 150 ; A., ii, 634ANALYTICAL CHEMISTRY. 149under examination, and is capable of yielding the same ions to thesolution, whilst the second, or comparison electrode, is composedof the same metal as the first and of the precipitate or otherproduct of the reaction. Owing to the slow action of the electrode,the method does not give sharp results in the titration of hydrogen-ion concentration.8' A hydrogen eleotrode giving a sharp end-point in acidimetric titrations has been described, and shown tobe suitable for the estimation of strong acids in the presence ofweak acids.8" Other electrometric methods may be used for theestimation of weak acids, such as acetic acid, in the presence ofstrong aoids, such as hydrochloric acid.83 A simple metho'd ofacidimetric or alkalimetric titration is to connect the solution tobe titrated with another of known I', value, each being providedwith a hydrogen electrode, and to continue the titration until thesame hydrogen-ion concentration is shown by both solutions.84Carbonic acid and its salts in dilute solution can be titrated in thisway,85 whilst phosphoric acid in dilute solution behaves like amono- or di-basic aoid, the first end-point being sharp, whilst thesecond is less distinct.86A method for the electrometric estimation of arsenic in colouredsolution is t o titrate arsenic trioxide with iodine solution in thepresence of sodium hydrogen carbonate, and to titrate arsenicpentoxide in sulphuric acid solution a t 9 5 O with sodium iodidesolution.87 Lead and zinc salts may be accurately titrated withpotassium ferrcoyanide, but in the case of other metals the pre-cipitates are not constant in composition .88The fact that mercuric acetate forms a stable, complex coni-pound with ally1 alcohol has been utilised for the electrometrictitration of that alcohol by means of a standard solution of themercury salt.89The presence of soluble ferricyanides or ohlorides in moderateproportion does not interfere with the titration of ferrocyanideswith potassium pernianganate solution, but salts yielding pre-W. D.Treadmelland L.Weiss, HeEu. Chim. Acta, 1919, 2, 680; A.,W. D. Treadwell and L. Weiss, ibid., 1920, 3, 433 ; A . , ii, 553.8a I. M. Kolt.hoff, Rec. trav. chim., 1920, 39, 280 ; A., ii, 327.84 P. E. Klopsteg, Science, 1920, 52, 1 s ; A., ii, 700.85 I. M. Kolthoff, Zeitsch. anorg. Chem., 1920, 112, 155 ; A., ii, 705.86 I. M. Kolthoff, ibid., 165 ; A., ii, 705. *' C. S. Robinson and 0. B. Winter, J . I n d . Eng. Chem., 1920, 12, 7 7 5 ;ii, 119.A., ii, 635.Erich Muller, Zeitsch. angew. Chem., 1919, 32, 351 ; A;, ii, 54.E. Biilmann, Medd. K. Vetenskapsakad. Nobel-Inst., 1919, 5, 1 ; A . ,i, 131150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.cipitates with either ferro- or ferri-oyanides must not bepresent.90The alcoholic strength of beer or wine may be rapidly estimatedby distillation with magnesium oxide (after removal of carbondioxide), treatment of the distillate with oxalic acid solution, anddetermination of the specific conductivity of the mixture and ofthe original oxalic acid solution.The required result is thenobtained by the use of a formula.91Amino-acids may be estimated alkalimetrically by means of thehydrogen electrode, and a simple method for the purpose has beende~ised.9~ The conductometric process has also been adapted tothe titration of phenols, cresols, and certain hydroxy-acids.93 Asimilar process has been worked out for the estimation of alkaloidsand their salts, the alkaloids themselves being titrated with acid,whilst alkaloid salts are titrated with alkali.94An indirect method for the electrolytic estimation of halogenshas been based on the fact that the solution can be electrolysed bymeans of a silver anode, with the formation of an adherent depositon the anode, and without precipitation in the solution, providedthat an anode potential of 0.59 volt is not exceeded.95When an ammoniacal solution of nickel and a salt of arsenicacid is electrolysed, the nickel is quantitatively precipitated with-out any arsenic, whereas cobalt under the same conditions carriesdown a certain proportion of arsenic.96Reference may also be made to methods in which rotatingreductors are used in the estimation of iron97 and of m0lybdenum.~8Water Analysis.The principal contributions to the analysis of drinking-waterhave been in connexion with the dissolved carbon dioxide.It hasbeen shown that the simple mass-law equation of the primaryionisation of carbonic acid enables the hydrogen-ion concentrationof natural waters to be approximately calculated .99I n titrating the free carbon dioxide and that present as hydrogenG. L. Kelley and R. T. Bohn, J . Amer. Chem. SOC., 1919, 41, 1776 ; A.,ii, 134.91 I. M . Kolthoff, Rec. trav. chim., 1920, 39, 126 ; A., ii, 198.ga E. L. Taube, J . Amer. Chem. SOC., 1920,42, 174; A., ii, 396.98 I. M. Kolthoff, Zeitsch. anorg. Chem., 1920, 112, 187 ; A., ii, 711.94 I. M. Kolthoff, ibid., 196; A., ii, 781.96 J. H. Reedy, J . Amer. Chem. Soc., 1919, 41, 1898; A., ii, 122.96 N. H. Furman, ibid., 1920, 42, 1789 ; A., ii, 710.g7 W. Scott, J. Ind. Eng. Chem., 1919, 11, 1135; A., ii, 128.B8 W. Scott, ibid., 1920, 12, 578; A., ii, 578.g s R. E. Greenfield and G. C. Baker, ibid., 1920, 12. 989; A., ii, 771ANALYTICAL CHEMISTRY. 151carbonate in moorland waters, errors are caused1 by the presenceof weak organic aaids which are simultaneously titrated. To deter-mine the solvent action of such waters on limestone, the water isshaken a t intervals with pow'dered marble in a closed flask, and aportion then titrated with N / 10-acid. The difference between theresult and that obtained without the addition of marble gives theamount of calcium carbonate dissolved.1It has been shown by Tillmanns and Heublein2 that the freecarbon dioxide in soft water has a much greater solvent action oncalcium carbonate than the same amount of carbon dioxide in hardwater. In the oase of waters containing iron hydrogen carbonate,the semi-combined and the combined carbon dioxide in the ironcompound are titrated simultaneously with the free carbondioxide, and, as a correction, 1.1 milligram of carbon dioxide mustbe deducted for each milligram of ferric oxide present.3In using Escaich's colour test for nitrites4 in water, the resultsare uncertain in the presence of ohlorides, which must therefore beremoved by means of silver nitrate before applying the test.5C. AINSWORTH MITCHELL.1 V. Rodt, Chem. Zeit., 1920, 44, 469 ; A., ii, 507.2 Gemndheits-Ing., 1912, 35, 669 ; A., 1913, ii, 51.3 H. Noll, Zeitsch. angew. Chem., 1920, 33, i, 182 ; A., ii, 555.J . Pharm. Chim., 1918, [vii], 17, 395; A., 1918, ii, 273.A. Escnich, ibid., 1920, [vii], 22, 138 ; A., ii, 644

ISSN:0365-6217    

DOI:10.1039/AR9201700130

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.SINCE writing last year’s Report the deaths of the following haveoccurred: G. von Bunge, Sir Thomas Fraser, Armand Gautier,Wilhelm Pfeffer, Max Siegfried, and Nathan Zuntz. Von Bungewas Professor of Physiological Chemistry a t Basle, and the authorof a well-known text-book. His best known research was con-cerned with the mineral constituents of blood and milk. Fraserwas for many years professor of materia medica at Edinburgh; heintroduced Calabar beans into medicine in the early sixties, buti t is chiefly during the last decade that physostigmine has at-tracted much attention from organic chemists. A study of arrowpoisons led him to the therapeutic application of strophanthin ;he made also an extensive study of snake venoms, and his nameis associated with that of Crum Brown in the generalisation thatquaternary salts of organic bases have a curare-like action.Gautier, the veteran of French biochemistry, originally receiveda medical training, but became later assistant to Wurtz and wasfor many years Professor of Medical Chemistry a t Paris.He isknown for his studies on ptomaines and on the occurrence of thebiologically rare elements (fluorine, arsenic, etc.). He also workedon arsenical drugs and questions of hygiene, food and generalchemistry.Pfeffer’s Osmotische Untersuchungen,” published in 1877,became known five years later to Van’t Hoff, through the latter’sbotanical colleague, de Vries, and thus became one of the mostfruitful stimuli ever given by biology to physical science.Doubt-less Pfeffer owed some of his success to his early training as achemist ; his doctor’s dissertation related to an organic chemicalproblem. Siegfried also began as an organic chemist; as assistantt o Drechsel he was diverted to physiological chemistry. He be-came extraordinary and (1919) ordinary professor of this subjecta t Leipzig. His best known work is on the extractives of muscIeand the kyrines. Zuntz, on the other hand, was by training aphysiologist, and an early appointment a t the Agricultural Collegeof Poppelsdorf, near Bonn, determined his career. He was mainly15PHYSIOLOGICAL CHEMISTRY. 153concerned with nutrition and gaseous interchange, for which heworked out exact methods of gas analysis. At Berlin he wouldrejoice in later years in showing visitors his respiration chambercapable of accgmmodating an ox.I n July, 1920, an international congress of Physiology met a tParis; the next meeting is to take place a t Edinburgh in 1922.I n France the SociM de Chimie Biologique,’founded in 1914, hasresumed the publication of its Bulletin.After two pre-war num-bers, the third followed in October, 1919, and others during thepresent year. Besides original papers there have been occasionalr6sum6s of current questions, valuable on account of their lucidity.During the year a new periodical of biochemical interest hasbegun under the title of the British Journal of ExperimentalI n America a series of monographs has now also been started,‘ I on experimental biology and general physiology.” Some of thoseannounced are on more or less chemical subjects. I n the series of“ Monographien aus dem Gesamtgebiet der Physiologie derPflanzen und der Tiere,” there appeared last year I f Die Narkose inihrer Bedeutung fur die allgemeine Physiologie,” by H.Winter-stein, and this year, “Die biogenen Amine,” by M. Guggenheim,The latter is an excellent up-to-date account of the chemical andphysiological properties of the simpler bases of biological interest,written by a well-known worker on the subject. The productionof large hand-books has been resumed in Germany to some extent.A new ‘‘ Handbuch der biologischen Arbeitsmethoden ” is appear-ing under the general editorship of E. Abderhalden. It willreplace the (‘ Biochemische Arbeitsmethoden,” now out of print,and is on a very extensive scale; there will be 13 parts, of whichthe first, dealing with purely chemical methods, is of primaryinterest to us here.By the publication, towards the end of 1920,of the second half of his Lehrbuch der physiologischen Chemie.”E. Abderhalden has completed the fourth edition. The first halfappeared more than a year ago. The second half (which actuallybears the date 1921) has been almost entirely rewritten. It is afew pages shorter than Vol. 11. of the 1915 edition, in spite of anew chapter on vitamins. I n 1920 there has also appeared Part11. of the first. volume of a “Handbuch der experimentellen Phar-niakologie,” edited by A. Heffter. This, the first instalment ofthe whole work, deals with many important alkaloids, for example,cinchona alkaloids and derivatives, colchicine, cocaine, ipecacuanhaalkaloids, strychnine.The manuscript was prepared before thewar and although some articles have apparently been revised to1918, others do not extend beyond 1913, and do not take intoPathology 154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.account the therapeutic discoveries of the war. The book will,however, doubtless interest some chemists. Two outstandingFrench books on bacteriology should also be mentioned here, boththe result of scientific isolation during the war: “Trait6 del’immunit6 dans les maladies inf ectueuses,” by J. Bordet, and(‘L’infection bacillaire et la tuberculose chez l’homme et chez lesanimaux,” by A.Calmette. The former book especially shouldappeal to anyone seeking a chemical basis for immunologicalphenomena.Me t a b o lism of Car b o hydra t es .The hypothesis of Chauveau, that fats only become a source ofmuscular energy after they have been transformed into carbo-hydrates, was shown to be untenable some twenty years ago by thework of Zuntz and his pupils, who drew the conclusion that fatsand carbohydrates are isodynamic, that is, that in both theseclasses of foodstuffs the same fraction of the heat of combustioncan be converted into work. The researches of Fletcher, Hopkins,A. V. Hill and others have, however, made it pretty certain thatthe process of muscular contraction is associated with chemicalreactions of substances closely related to the carbohydrates, andthen it becomes difficult to understand that the utilisation of fatsis not attended by some loss of energy.These considerations haveled A. Krogh and K . G. Lindhard to an important reinvestigationof the relative value of fat and carbohydrate as sources of muscu-lar energy.’’ Their method involved the determination of therespiratory quotient of a subject working an ergometer in a respira-tion chamber, and they determined this quotient within 0.005 byvery accurate analysis of the air passing through the chamber. Inconnexion with this A. Krogh has published subsidiary papers2 ona gas analysis apparatus accurate to 0*001 per cent., and on thecalibration, accuracy and use of gas meters, which papers may be ofuse to non-biological chemists. Krogh and Lindhard find that thenet expenditure of energy (after deducting the standard meta-bolism) necessary to perform the equivalent of one calorie oftechnical work on the ergometer varied from 4-5-5 calories.Inthe three best series of experiments it was 4.6 cal. when fat alonewas catabolised (R.Q. =0-71) and 4.1 cal. for carbohydrate alone(R.Q. = 1.0). This shows a waste of energy from fat of 0-5 cal., or11 per cent. of its heat of combustion. The authors suggest as aworking hypothesis that both during rest and work the proportionof fat to carbohydrate katabolised is a function of the available1 Biochem. J . , 1920,14, 290 ; A., i, 692.a Bid., 267, 282 ; A., ii, 553, 630PHYSIOLOGICAL CHEMISTRY.155supply of these substances. With the respiratory quotient below0.8 carbohydrate is formed from fat and provisionally stored; thereverse transformation takes place with a respiratory quotientabove 0.9.A novel aspect of the metabolism of reducing sugars is dealt withby J. A. Hewitt and J. Pryde,3 who find that solutions of dglucose introduced into the intestine of the living animal undergorapid downward mutarotation from + 52-5O to below + 1 9 O , and inone experiment the solution even became Ibevorotatory. Onwithdrawal from the intestine the reverse change takes place moreslowly, until the original rotation of a- and P-glucoses in equili-brium is reached. This change is not due to preferential absorp-tion of the a-form or t o disaccharide formation, but probably tothe formation of y-glucose in excess of any amount normallypresent in glucose solution which has reached an equilibrium.Pro t eins .Various classifications of proteins have been discussed by P.Thoinas.4 The two principal methods for determining the degree ofhydrolysis of a protein are that of Van Slyke, who determines thefree amino-groups, and that of Sorensen, who titrates the carboxylgroups. The former method has been elaborated into an indirectanalysis of amino-acids in groups, of which the largest is that withamino-nitrogen, comprising glycine, alanine, serine, phenylalanine,tyrosine, valine, the three leucines, aspartic and glutamic acids.This large group A.C . Andersen5 subdivides further by neutralis-ing the solution with sodium hydroxide in the way indicated bySorensen for his formol titration.Under these conditions onlyaspartic and glutamic acids combine with one equivalent of sodiumhydroxide, and the monocarboxylic acids remain in the free state.On ashing such a solution the amount of sodium carbonate in theresidue is equivalent to the monamino-dicarboxylic acids present.Amino-A cids.H. D. Dakin 6 has synthesised racemic /3-hydroxyglutamic acid,of which an active modification was discovered by him in casein.'The synthesis presented unexpected difficulties and severalattempted methods failed or gave only minute yields. The bestBiochem. J . , 1920, 14, 395; A., i, 508.Bull. SOC. Chim. biol., 1920, 2, 112 ; A., i, 644.Kong. Vet.oy Landboh6jskole Aarslcrift, 1917, 308 ; A., ii, 647.Biochem. J., 1919, 13, 398 ; A., i, 294.Ann. Reports, 1919, 16, 153; A., 1919, i, 150156 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.results were obtained by the following method. Glutamic acidwas converted by potassium cyanate into a-carbamidoglutaric andthen into hydantoinpropionic acid (I). The action of bromine onYO-NH 70-NH YO-NH YO,HCH-NH CH*NH >” CH-NH CH*NH,(33, 6HBr 6H CH-OH60,H 60,H CO,H 60,H..CH, 6H2 CH 6H2(1.1 (11.) (111.) (IV.)the latter is complex; after bromine enters the molecule it issplit off again as hydrogen bromide, introducing a double bond inthe By-position, but when the bromination is carried out in glacialacetic acid saturated with hydrogen bromide, the latter is addedon again and i-hydantoin-P-bromopropionic acid (11) results.Onboiling this with water hydantoinacrylic acid (111) is formed withthe double bond in the required ab-position. This acid is boiledwith baryta solution until half the nitrogen has been evolved asammonia, indicating the complete opening of the hydantoin ring.At the same time a molecule of water is added and inactive 0-hydroxyglutamic acid (IV) results, in a yield of 20 per cent. ofthe hydantoinacrylic acid or 2 per cent. of the glutamic acid em-ployed. The original paper should be consulted by organic chemistsdesirous of effecting a smoother synthesis. A secondary result ofDakin’s experiments was the preparation of malic semi-aldehydeCHO-CH(OH)*CH2*C02H, which, however, does not lend itself tothe application of the Strecker synthesis.Apart from casein Dakin has now also found his new amino-acidin glutenin (2.4 per cent.) and in gliadin (1.8 per cent.); D.B.Jones and C. 0. Johns8 have also isolated it from stizolobin, theglobulin of the Chinese velvet bean (yield 2.8 per cent.). In dogsrendered diabetic by phloridzin, 0-hydroxyglutamic acid appearsas (‘extra glucose,” as is the case with glutamic acid, proline andornithine, and the’ amount was found to correspond closely withthat derivable from three of the five carbon atoms. Dakin con-siders that P-hydroxyglutamic acid very likely arises in the bodyfrom glutamic acid and would then constitute an example of‘(P-oxidation” such as is known to occur in fatty acids, but hasnot yet been observed in amino-acids.Thus proline would beconverted to glutamic acid via pyrrolidon&arboxylic acid, andornithine would also be converted into glutamic acid. The latterwould then be changed into dextrose by successive conversion into8 J. Biol. Chem., 1919, 4Q, 435 ; A., i, 191PHYSIOLOGICAL CHEMISTRY. 157P-hydroxyglutamic, malic and lactic acids, two molecules of thelatter forming the hexose. In support of this view Dakin hasoxidised 6-hydroxyglutamic to malic acid in vitro and the bio-chemical conversion of the latter into sugars has been broughtabout in several ways.A new method for preparing esters of amino-acids has beenpublished by F. W. Foreman.9 It consists in converting theamino-acids into their dry lead salts, which are suspended inabsolute alcohol and esterified by saturating with hydrogen chloride.After removal of the free hydrochloric acid and the alcohol, theester hydrochlorides are dissolved in dry chloroform and the freeesters liberated by shaking with anhydrous barium hydroxide.Thus the considerable loss of esters by hydrolysis is avoided, whichoccurs in aqueous solution.The process has been applied tocaseinogen and some of the deficit has been accounted for, withouthowever taking Dakin’s above-mentioned hydroxyglutarnic acidinto account. Although amino-acids are usually formulated withtervalent nitrogen and free carboxyl, they might also be repre-sented as internal anhydrides of an acid with an ammoniumhydroxide.This “ betaine ” formula, originally suggested by R.Willstatter, was supported experimentally by A. Geake and M.Nierenstein,lo who found that amino-acids are not methylated inethereal suspension by diazomethane. J. Herzig and K. Land-steiner 11 have confirmed this observation as regards glycine andalanine, but find that in other amino-acids the carboxyl groupis slowly and a t least partly esterified, so that in them there appearsto be an equilibrium between the two forms thus:-NH2*CH,-C0,€I and hH3*CH2*CO*0.An unstable variety of glycine, differing from the ordinary onein crystalline form, has been described recently by H . King andA. D. Palmer.12 Presumably this is the variety correspondingwith the former of the above two formulae, with a free carboxylgroup, and it might be made to react with diazomethane.Eingand Palmer consider it probably identical with the fine needleswhich Emil Fischer obtained on precipitating an aqueous glycinesolution with alcohol; it is the only variety of glycine that reactswith phosphorus pentachloride, which reaction also postulates a freecarboxyl group. King and Palmer are mainly concerned with con-firming the existence of compound of glycine with neutral salts,lo Zeitsch. physiol. Chem., 1914, 92, 149 ; A., 1914, i, 1057.l2 Biochem. J., 1920, 14, 576 ; A , i, 823.-IBiochem. J., 1919, 13, 378 ; A., i, 338.Biochem. Zeitsch., 1920, 105, 111 ; A , i, 719158 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.described by Pfeiffer and his co-workers and called into questionby Bayliss.Hydroxyproline contains two asymmetric carbon atoms andin addition t o the natural acid three stereoisomerides shouldexist.All have now been obtained by H. Leuchs and K. Bor-mann.13 The puzzling transformation of tryptophan in theorganism of the dog into kynurenic acid has now been almostcertainly elucidated by A. Ellinger and Z. Matsuoka 14; they syn-thesised indole-3-pyruvic acid and' found that, like tryptophan, itis converted into kynurenic acid. The mechanism of the formationof this quinoline derivative would therefore presumably be asfollows : -"-C*CH2*CH(NH,)*C0,H ()-,C* CH,* CO CO,H+ \/\/NH KEcoI Q",\ I ,NH*C02HC-OHHere indolepyruvic acid figures as the first transformation pro-duct of tryptophan, which is in accordance with the known beha-viour of other amino-acids.15 As Ellinger and Matsuoka point out,the only criticism which can be urged is, that indolepyruvic acidis first transformed to tryptophan and that the amino-acid isconverted into kynurenic acid by some other reaction, for it hasbeen shown that, for instance, pyruvic acid itself may yieldalanine, and phenylpyruvic acid phenylalanine, when perfusedthrough the surviving liver.The hydroxyl group of kynurenicacid must be represented in its precursor, for quinoline-a-carboxylicacid is not oxidised to kynurenic acid in the dog, but is excretedpartly unchanged, partly combined with glycine. The Hopkins-Cole test for tryptophan has been examined by W.R. Fearon l6in a suggestive paper. Although the conclusions are based onIs Ber., 1919, 52, [B], 2086; A., i, 185.I4 Zeitsch. physiol. Chem., 1920, 101, 259 ; A., i, 696.Is For example, F. Knoop and E. Kertess, ibid., 1911, 71, 252 ; A., 1911,l6 Biochem. J . , 1920, 14, 548 ; A., ii, 786. ii, 514PHYSIOLOGICAL CHEMISTRY. 159molecular weight and nitrogen determinations only of amorphouspigments, and are theref ore somewhat speculative, a considerableadvance has been made, which ought to be useful in dealing withother substances (for example, alkaloids) related to tryptophan.Two molecules of indole, scatole, tryptophan or carbazole, werecondensed with one molecule of an aldehyde (formaldehyde,glyoxylic acid, benzaldehyde) in pure glacial acetic acid bymeans of hydrogen chloride too leuco-compounds, which are oxidisedto pigments, for example, for scatole.H RCRC \/II II I I II II\/\/ \\A/A/\/\--\/\/ \\A/+OMell 11 I I I II Me-/\/\A-Me --fNH NH NH NIt will be seen that they are regarded as related to diphenyl-methane dyes.With tryptophan and formaldehyde or glyoxylicacid in the above-mentioned proportions the compounds are red, butwith three molecules of the aldehyde to two of tryptophan bluecompounds result, which are considered to arise from the condensa-tion of the two additional aldehyde molecules with the two trypto-phan side chains to form carboline derivatives of the type foundin harman.17 It is thus clear that blue compounds cannot be ob-tained from tryptophan combined as peptide, but red compoundsmight perhaps be expected in this case.As usually carried out,the Hopkins-Cole test results in a mixture of tryptophan redand blue.Various colorimetric methods for estimating tryptophan havebeen examined by P. ThomasY18 who prefers the use ofp-dimethylaminobenzaldehyde as advocated by E . Herzfeld .19Thomas finds 1.7-1.8 per cent. in caseinogen, and as much as 2.3per cent. in cerevisin, a protein from yeast, which is evidentlyable to form tryptophan from simpler compounds.Similarly, L. Hugounenq and G . Florence20 find that Aspergillusforms tryptophan when it has as only source of nitrogen any oneof a series of natural amino-acids (it does not grow on phenyl-glycine) . These authors also prefer p-dimethylaminobenzaldehydefor17115,181920detecting tryptophan.Ann.Reports, 1919, 16, 156.967.Bull. SOC. Chim. biol., 1914, 1, 67 ; A., i, 266.Biochem. Zeitsch., 1913, 56, 258 ; A., 1913, ii, 1088.Bull. SOC. Chim. biol., 1920, 2, 13 ; A., i, 466.The synthesis of tryptophan has alsoW. H. Perkin and R. Robinson, T., 1919160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been investigated by W. J. Logie21 in various bacteria, for example,B. Coli, which can form it from straight-chain compounds suchas ammonium lactate and sodium aspartate, and also from freeindole; the appearance of indole in some cultures may be attri-buted both to increased production and diminished consumption.The action of bacteria on amino-acids has been further studied inJapan by T.Sasaki 22 and his pupils. Thus K. Hirai 23 has foundthat B. Zactis aerogenes, like yeast, forms tyrosol from Z-tyrosine,but only in minute quantity. The same author 2* finds that astrain of Yroteus vulgaris, capable of converting Z-tyrosine intocl-p-hydroxyphenyl-lactic acid, also converts histidine intod-/3-iminazolyl-lactic acid. This new degradation of histidineshould be compared with the production of urocanic (iminazolyl-acrylic) acid by bacilli of the Coli group, observed by H. Raistrick.25The curious difference in the stereo-chemical behaviour of B.proteus and B. subtilis originally observed by Sasaki for tyrosine,has been also demonstrated for d-Z-phenylalanine by H. Amatsu andM. Tsudji.26With Henderson’s phosphate mixture phenyl-lactic acid and verylittle phenylethylamine is formed, 23.proteus forming the dextro-and B. subtilis the laevo-variety of the acid. If instead of Hen-derson’s mixture, uranyl phosphate and milk sugar are used asnutrient medium the amine is formed to the exclusion of the acid.The Gases of the Blood.This subject, more than any other, continues to occupy Englishphysiologists, four out of the five papers in the current numberof the Journal of Physiology are concerned with it. R. Wert-heimer 27 has confirmed the observation hitherto only madeaccurately by R. A. Peters28 that oxygen and hzmoglobin combinein molecular proportions as originally suggested by Hufner. Itshould be noted, however, that Peters’ values apply to hzmoglobinin the presence of dilute ammonia, and that Wertheimer onlyobtained agreement with these values in the presence of sodiumcarbonate; hzemoglobin dissolved in pure water had an oxygen21 J .Path. Bact., 1920, 23, 224 ; A., i, 912.22 Compare Ann. Reports, 1917, 14, 190, 191.23 Acta Scholae Med. Univ. Kyoto, 1918, 2, 425 ; A., i, 581.24 Ibid., 1919, 3, 49 ; A., 1919, i, 612.26 Ann. Reports, 1917, 14, 191 ; A., 1917, i, 499; Biochem. J., 1919, 13,446 ; A., i, 348.Acta Scholae Med. Univ. Kyoto, 1918, 2, 447 ; A., i, 581.27 Biochem. Zeitsch., 1920, 106, 12 ; A., i, 773.28 J . Physiol., 1912, 44, 131 ; A., 1912, i, 519PHY SIOLOQICAL CHEMISTRY. 161capacity 7 per cent. smaller. It is, however, the carbon dioxide inblood rather than the oxygen which stimulates work and con-troversy.We may first consider those authors who attempt toutilise the laws of mass action and of electrolytic dissociation tothe full, without perhaps always considering sufficiently whetherthese laws apply to a colloidal solution like plasma or to a grosslyheterogeneous system like whole blood.T. R. Parsons29 has attempted to calculate the carbon dioxidedissociation curve of blood on the assumption that a fixed amountof sodium is shared between two weak acids, namely, carbonic acidand haemoglobin (with plasma proteins). The changes of reactionin blood due t o increase of carbon dioxide pressure are much moregradual than in a sodium hydrogen carbonate solution because theproteins, and especially hzemoglobin, act as ‘‘ buffers.” HEmo-globin would therefore have as important a function in carbondioxide transport and maintenance of normal hydrogen ion concen-tration as in the transport of oxygen.The share of the plasmaproteins (as distinct from haemoglobin) in this buffer action is stilla matter of dispute. I f they act as buffers at all they must formionised salts. A. R. Cushny30 denies this; he filtered serumthrough collodion and found all the crystalloid constituents t o bepresent in the same concentration in the filtrate as in the serum(with the exception of calcium and probably of magnesium).F. G. Eopkins,31 on the other hand, evidently believes in theexistence of ion-proteins. W. M. Bayliss32 finds that the plasmaproteins play no perceptible part in the maintenance of neutralitybetween limits of hydrogen ion concentration possible in the livingorganism.Parsons, in his second paper quoted above, considersthat the weak acid competing with carbonic for the sodium ismainly, if not entirely, hmnoglobin. Using a similar conception,L. J. Henderson 33 has attempted t o explain the simultaneousreaction of hzemoglobin with oxygen and with carbon dioxide. Heis led to the assumption that a certain acid radicle of reduced hzemo-globin has a dissociation constant of 2.3 x 10-8, which is increasedin oxyhaemoglobin t o 2.0 x 10-7, thus expressing quantitatively anidea put forward by J. Christiansen, C. G. Douglas, and J. S.Haldane.34 When the hmnoglobin thus becomes more electro-lytically dissociated owing to its taking up oxygen, it also takes up2 9 J .PhyeioZ., 1919, 53, 42, 340 ; A., i, 508.30 Ibid., 1920, 53, 391 ; A., i, 508.81 Brit. Med. J., 1920, ii, 70.8% J. Physiol., 1920, 53, 162 ; A., i, 607.53 J . Biol. Chem., 1920, 41, 401 ; A., i, 403.34 J . Physiol., 1914,48, 244; A., 1914, i, 1012.REP.-VOL. XVn. 162 A"U& REPORTS ON THE PROGRESS OF CHEMISTRY.more base (sodium) and carbonic acid is set free. (This would bethe process in the lungs; the reverse would occur in the tissues.)It is impossible to do more here than indicate the fundamentalnotion of Henderson's paper.I n such theoretical speculations it is important to rememberthe observation made 30 years ago by Hamburger that red bloodcorpuscles are permeable t o chloride and phosphate ions; hispupil S.de Boer 35 more recently showed the same t o be the casefor sulphate ions. This ionic interchange between plasma andcorpuscles has lately attracted the attention of a number ofworkers. L. S. Fridericia36 finds that the increased chlorinecontent of the corpuscle can be demonstrated a t low pressures ofcarbon dioxide in the plasma, for example, 0.1 atmosphere. Theamount of chlorine gained by the corpuscles on increasing thecarbon dioxide pressure from 0.08 t o 162 mm. almost completelyaccounts for the increased carbon dioxide-combining power coinci-dently gained by the plasma. The hydrogen ion concentrationsof plasma and corpuscles remain fairly constant. This is anextension of K.A. Hasselbalch's37 attempt t o explain thatwhereas a sodium hydrogen carbonate solution contains the sameamount of carbon dioxide a t all (except very low) pressures ofthe gas, in blood, on the other hand, the carbon dioxide-combin-ing power increases with the pressure (as if bicarbonate had beenadded). Hasselbalch invokes the ampholyte character of haemo-globin, which he conceives as having an acid character a t lowcarbon dioxide pressures so that it displaces carbon dioxide frombicarbonate, and alkaline qualities a t high carbon dioxide pres-sures, so that it combines with increasing amounts of carbondioxide. The obvious question remained, how can bmoglobinin the corpuscles influence bicarbonate in the plasma ? Fridericiainsists that the necessary link between the two phases is to befound in the wandering of the anions.13. Straub and E. Meier 38have approached the same question by subjecting corpuscles inphysiological saline to various concentrations of carbon dioxide.The corpuscles themselves act as buffers, their P, being 7.00 whenthat of the solution was 6-67, The authors connect this effectwith the partial permeability and the colloidal properties of thecorpuscles. Their work has been discussed by L. Mi~haelis.~~Working on somewhat similar lines, J. M. H. Campbell and E. P.86 J . PAySiol., 1917, 51, 211 ; A., 1917, i, 671.86 J . Biol. Chem., 1920, 42, 245 ; A,, i, 648.87 Biochem. Zeitsch., 1916, 78, 112 ; A., 1917, i, 490.s8 Ibid., 1918,89, 156 ; 90, 305 ; 1919, 98, 205, 228.A., 1918, ii, 467 ;1919, i, 63 ; 1920, i, 200. aa Ibid., 1920,103, 53 ; A., i, 679PHYSIOLOGICAL CHEMISTRY. 163Poulton40 also find the isoelectric point of haemoglobin a t P, 6.98Under physiological conditions the blood proteins act as acids anddo not themselves combine with carbon dioxide until the blood ismuch more acid than ever happens in the body. The partitionof carbon dioxide between corpuscles and plasma a t differentcarbon dioxide pressures has also been recently investigated byJ. Joffe and E. P. Poulton 41 with results similar t o those ofStraub and Meier. The former authors criticise D. D. van Slykeand G. E. Cullen’s method,42 for the determination of the alkalireserve, because the venous plasma, after the separation of thecorpuscles, is brought into equilibrium with alveolar carbon dioxide,so that an ionic interchange with the corpuscles can no longer takeplace.In most of the above papers carbon dioxide is not consideredto be combined with the blood proteins, but t o be entirely presentas bicarbonate (at least under physiological conditions).Thisview is opposed by G . A. Buckmaster,43 who revived Bohr’s con-ception of a direct combination between carbon dioxide and h m o -globin. A third view has recently been put forward by J.Mellanby and C. J. Thomas44 in a paper which contains some novelexperiments and views running counter to the current conception.These authors studied more particularly the ash associated withthe blood proteins under various conditions.For instance, theprotein precipitated from serum by adding an equal volume ofalcohol a t -loo is associated with a large amount of inorganicsalt. When redissolved in water this protein combines with morecarbon dioxide than can be calculated as existing in combinationwith the alkaline salt ; from this and other experiments Mellanbyand Thomas conclude that the carbon dioxide is adsorbed, chieflyon the fibrinogen, and that the proteins effect the transport ofcarbon dioxide. Since a 0.2 per cent. solution of sodium hydrogencarbonate is not precipitated by an equal volume of alcohol a t-loo, it is incidentally concluded that this salt does not exist freein serum. The authors consider the bicarbonate hypothesis inad-missible (according to which the sodium is shared between car-bonic and another weak acid).Sodium hydrogen carbonate withprotein constitut,es the alkali reserve. In shed blood lactic acidis produced from the corpuscles and that is why the carbon dioxideof shed blood falls steadily, and why this gas can be extractedcompletely from blood in a vacuum, but not from serum.It seems t o the writer that if the bicarbonate is adsorbed by theq o J . Physiol., 1920, a, 152.4 2 Ann. Report8, 1917, 14, 173.44 J . Physiol., 1920, 541, 178.q1 Ibid., 129.q3 Ibicl., 1918, 15, 147.a 164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.serum proteins, the latter still may transport carbon dioxide assalt, in accordance with the view more generally accepted.Mellanbyand Thomas lay great stress on the colloidal properties of serumand support the doubt, expressed above, that the laws of equili-brium in homogeneous systems are not immediately applicable tothis case.The estimation of carbon monoxide in blood and of the latter’sCO-capacity has been described by M. Nicloux.46An interesting contribution to the technique of determining thehydrogen-ion concentration of blood has been made by H. H. Daleand C. L. Evans.46 They dialyse about 5 C.C. of oxalated bloodinto 1 C.C. of saline, avoiding loss of carbon dioxide. The PH ofthe dialysate is then found colorimetrically, by mixing phosphatesolutions until the mixture gives with neutral-red the same d o u ras the dialysate. The method appears to be very convenient andaccurate, and may well be applicable t o fluids other than blood.The regulation of the blood’s alkalinity has been investigated byH.W. Davies, J. B. S. Haldane, and E. L. Eennaway,47 who finda t high carbon dioxide-pressures a considerable deviation fromParsons’ theoretical dissociation curve, ref erred to above. Theystudied the effect of eating large quantities of sodium hydrogencarbonate, which produces increased carbon dioxidecapacity of theblood, increase in alveolar carbon dioxide, rapid excretion of bicar-bonate in the urine, disappearance or great decrease of urinaryammonia and sometimes appearance of acetone substances. Theseeffects illustrate the way in which the organism compensates foralkalosis by changed respiration and metabolism.The ammonianormally excreted in the urine would ultimately appear as neutralurea and the acid normally combined with it becomes available forneutralising the alkali ingested. For the related subject ofacidosis reference can here only be made t o papers by H. W.Haggard and Y. Henderson.4*Accessory Food A% bstancca.The name vitamines is all but established, in spite of the factthat it suggests a relationship t o amines, of which there is no proof.J. C. Drummond49 suggests a compromise by dropping the final“ e,” so as not t o suggest basic properties (to those familiar with theChemical Society’s nomenclature). He further calls f at-soluble-ABull. SOC. Chim. biol., 1920, 2, 171.46 J . Physiol., 1920, a, 167.48 J .Biol. Chem., 1920, 43, 3, 15.4g Biochem. J., 1920,14, 660 ; A., i, 908.4 7 Ibid., 32PHYSIOLOGIUAL CHEMISTRY. 166and water-soluble-B, simply vitamin-A , vitamin-23, etc. Workon accessory food substances is going on with unabated vigour inEngland and in America; there are also signs of increased interestin and recognition of the subject in France and in Germany. Onaccount of its great value, we may once more refer here to theSpecial Report No. 38 of the Medical Research Committee (nowResearch Council), which survey was mentioned in last year’sReport.It seems that the resistance of some accessory food factors tohigh temperatures has been somewhat underestimated. Thus R.Steenbock and P. W. Boutwell50 now report that the fat-solublevitamin-A of yellow maize is unaffected by heating for three hoursunder 7 kilos pressure, nor does this treatment appreciably diminishthe same factor in chard, carrots, sweet potatoes and squash.Therelative stability of vitamin-A is also insisted on by T. B. Osborne,L. B. Mendel and A. J. Wakeman,sl who cannot confirm thegreat thermolability formerly attributed to this substance fromanimal sources by H. Steenbock, P. W. Boutwell and H. E. Kent,6%and by J. C. Drummond.63 The explanation of this discrepancyis probably found in an experiment described by F. G. Hopkinsin opening a discussion on vitamins in clinical medicine a t theannual meeting of the British Medical Association last July. But-ter fat heated for four hours to 120° without aeration remainsactive, but when a stream of air is bubbled through it during theheating, it becomes inactive.It seems that the fat-soluble vitaminpossesses considerable heat-stability but is easily oxidised. Thatvitamins are readily destroyed by oxidation seems also to resultfrom the fact, related by A. F. Hess,55 that milk or neutralisedcanned tomato juice loses much of its activity by being shakenwith air for half an hour. The deleterious effect sometimes ob-served-in pasteurised milk may be the result of exposure to warmair rather than a simple temperature effect. G . F. Still56 pointsout that so-called “buddized milk,” sterilised by being warmedwith hydrogen peroxide to 50°, was found clinically to have lost itsanti-scorbutic properties. Laboratory experiments on the effect ofsuitable oxidising agents on the various vitamins a t roomtemperature now seem desirable.Similarly, E. M. Delf 57 findsthat the anti-scorbutic vitamin4 of orange and swede juice has6o J . Biol. Chem., 1920, 41, 163; A., i, 358.61 IbicE., 549 ; A., i, 457.62 J . Biochem., 1918, 35, 517 ; A., 1918, i, 513.Biochem. J., 1919, 13, 81 ; A., 1919, i, 363.54 Bm’t. Med. J., 1920, ii, 147.55 Ibid., ii, 154.57 Biochem. J., 1920,14, 211 ; A., i, 460.66 Ibid., 5, 166166 ANNUAL REPORTS ON THIE PROGRESS OF UHEMISTRY.an unexpec€edly great stability above looo if the heating is con-ducted in the absence of air. The practical bearing of these experi-ments on canning and other methods of food-preservation is obviousand the same applies to those of A.Harden and R. Robison,58 whofind that with suitable precautions orange juice may be evaporatedto dryness without loss of activity and that the dry residue retainsmuch of its activity after two years’ storage.A few further attempts have been made to isolate the water-soluble antineuritic vitamin-B, which for various reasons seemsto hold out more hope than vitamins-A or -C. The most interest-ing of these attempts is that made by F. Hofmeister and M.Tanaka,5Q who during the war isolated from rice polishings a baseoridine, C,H,,O,N, which as crude hydrochloride cured poly-neuritis of pigeons in small doses, but became inert when purifiedfor analysis. Either the antineuritic vitamin was a mere impurityin the crude crystals and therefore extraordinarily active, or theactive substance underwent chemical transformation during theprocess of purification (regeneration from aurichloride and recry-stallisation of the hydrochloride so obtained).Although theempirical formula of oridine is the same as that of valine, the sub-stance appears to be more closely related to pyridine and is possiblya dihydroxypiperidine. The result reminds one of C. Funk’searlier investigations when the antineuritic substance was asso-ciated with nicotinic acid. C . N. Myers and C . Voegtlin,GO usingmethods for the isolation of bases somewhat similar to thoseemployed by Funk, obtained from dried yeast a crystalline anti-neuritic substance which became inactive on drying. The methodof extracting vitamin-B from rice bran has been studied byB.C . P. Jansen,61 who states that an alcoholic extract of ricepolishings is now used in Java against beri-beri. He used 0.3per cent. aqueous hydrochloric acid, or 70 per cent. alco]hol, or96 per cent. alcohol with & volume of concentrated hydrochloricacid, and found that with each solvent the vitamin is completelyextracted in two days. He criticises curative experiments withpigeons as being uncertain unless much time is expended on them;it is better, and not necessarily slower, to find the minimum pre-ventive dose which must be added to a diet of polished rice.Much time may be saved by using a small species of Indian bird(Musica maja), which is far more sensitive than the pigeon.The results obtained in the laboratory with animals are now513 Biochem.J., 1920, 14, 171 ; A., i, 460.69 Biochem. Zeitsch., 1920,103, 218 ; A., i, 686.6olJ. Biot. Chem., 1920,42, 199 ; A., i, 500.Mededeelingen Geneeak. &ah. Webvreden, 1920, [iii], A, 23PHYSIOLOQIOAL CHEMISTRY. 167more and more being put to clinical use, most of all in Vienna.@Charts63 giving the effect of butter or cod liver oil and fresh turnipjuice, added to the diet of nursing mothers or of infants, demon-strate the same remarkable effect on the body weight of the chil-dren as has been studied in animals. Turnip juice contains theantiscorbutic vitamin and is a cheap substitute for lemon juice;its clinical value has now also been emphasised in Germany.MVarious gastro-intestinal disorders in adults are now attributed byR.McCarrison65 to vitamin deficiency and he has found, for in-stance, that healthy monkeys, carriers of Entamaba cysts, developdysentery when placed on devitaminised food.Evidence is accumulating that vitamins are not only necessaryfor animals, but also for some fungi. R. J. Williams’66 F. M.Bachmann,67 W. H. Eddy, and H. C. Stevenson6* estimate thestrength of vitamin ( B ? ) solutions by growing yeast cells in them.In his second paper Williams has made the method gravimetricby weighing the yeast. The method has been adversely criticisedby G. de P. Souza and E. V. McCollum,6g who find that manysubstances stimulate the growth of yeast. Pasteur already failedto grow yeast from a single cell in synthetic media, and Wildier70postulated a special substance, “ bios,” necessary for the growthof yeast cells.A similar relationship seems to hold for ScZerotkiacinerea, the fungus causing brown r o t in peaches and plums; ac-cording to J. J. Willaman,71 it does not grow on synthetic mediasufficing for AspergiZZu.s, for example, but it will grow when aI‘ vitamin ” preparation is added, obtained by means of adsorptionby fullers’ earth from a variety of animal and vegetable sources.This substance, like “ bios,” is thought to be identical with water-soluble vitamin-B, but such a speculation is of course incapable ofexact verification as long as vitamins have not been isolated.Indeed, the identity of the growth-promoting water-soluble vitaminwith the antineuritic, now generally presumed, is denied by A.D.Emmett in conjunction with G. 0. Lures" and with M. Stock-holm.73 That vitamins are necessary for fungi is also denied; A.LumiBre73Q finds that yeast heated to 135O and no longer capable62 (Miss) H. Chick, Brit. Med. J., 1920, ii, 131.I34 H. Aron and S . Samelson, Deutsch. med. Woch., 1920, 4.8, 772.65 Brit. Med. J., 1920, i, 822.66 J . Biol. Chem., 1919, 38, 465; 1920,42, 59; A., 1919, i, 463.67 Ibid., 1919, 39, 235 ; A., 1919, i, 613.68 Ibid., 1920, 43, 295 ; A., ii, 716.6f) Ibid., 1920, M, 113; A., i, 919.71 J . Amer. Chem. SOC., 1920, 42, 649 ; A., i, 412.72 J . Biol. Chem., 1920, 43, 266 ; A., i, 698.7s Ibid., 287 ; A., i, 701.asE. J . Ddyell, ibid., ii, 132.7 O La oellule, 1901, 18, 313.Cmpt. rend., 1920,171, 271 ; A., i, 663168 ANNUAL REPORTS ON W E PROGRESS OF CHEMISTRY.of curing polyneuritis gives a bouillon which greatly improves thedevelopment of fungi.From what has been said above it will beseen that Lumibe’s experiments are not necessarily in conflictwith those of Williams and of Bachmann. Heating to 135O maynot have left enough vitamin to cure pigeons; yet there might beenough to have a favourable effect on the growth of yeast. It iseven more difficult t o judge of the vitamin-nature of the crudenucleic acid derivatives in bacterised peat, which according toW. B. Bottomleg 74 favour the growth of Lemna in water culture.Experiments on the growth-promoting substances in various organicmanurial composts by F.A. Mockeridge76 seem to depend moredefinitely on the presence of purine and pyrimidine bases in thesemanures.Pellagra, a #disease occurring in countries (Italy, Caro-lina) where maize is the principal article of diet, has of late yearsbeen more and more considered due to a dietary deficiency, and ithas been suggested that the cause lies in the absence of tryptophanand perhaps also of lysine from zein, the chief protein of maize.The metabolic importance of the former amino-acid was estab-lished by E. G. Willcock and F. G. Hopkins 76 in the case of youngmice, that of the latter by T. B. Osborne and L. B. Mende1.77Occasional outbreaks of pellagra in institutions, camps, etc. ,have always cleared up on the inclusion of more milk, meat, eggsor cheese in the dietary, but whether the cure was due to trypto-phan in caseinogen is not thoroughly established.H. Chickand E. M. Hume78 describe experiments with monkeys on a dietrich in all known vitamins, but with zein as its principal protein.Symptoms closely resembling those of pellagra were produced andwere undoubtedly of dietary origin. In one case they cleared uprapidly when caseinogen was administered as well, but the crucialpoint, whether it was tryptophan which made the difference, couldnot be established with certainty. This amino-acid appeared tohave a beneficial effect, but no cure was effected with it alone.Ferments.The discussion on the diastase-like properties of formaldehyde,which has been carried on in Germany during the last few years,may be mentioned here, not so much as a contribution to our know-Proc.Roy. SOC., 1920, [B], 91, 83 ; A., i, 265.76 Biochern. J., 1920, 14, 432 ; A., i, 704.7 6 J . Physiol., 1906, 35, 88 ; A., 1907, ii, 88.7 7 J . Biol. Chern., 1914, 17, 325; A., 1914, i, 620.‘8 Biochern. J., 1920, 14, 135PHYSIOLOGICAL CHEMISTRY. 169ledge of enzymes, but rather as a curious example of scientificcontroversy. G. Woker and H. Maggi have repeatedly asserted,both separately and together,79 that formaldehyde has the power ofhydrolysing starch. They have been attacked by various criticsin a number of separate papers, and finally these critics havebanded themselves together in a final onslaught.80 The explana-tion of the supposed diastatic action of formaldehyde lies in thefact that the latter forms a loose additive compound with staroh(which compound does not give a blue cdour with iodine), andthat formaldehyde also modifies the physical properties of thecolloid.This view is shared by E. Herzfeld and R. Klinger,alwho hold similar views as to the action of formaldehyde and for-mulate, in addition, somewhat revolutionary ideas on starch hydro-lysis, according to which the formation of dextrins (includingachroodextrins) may be a purely physical change in the degreeof dispersion, without any hydrolysis. The hydrolysis of starch(by amylase) is also discussed in a suggestive, largely theoreticalpaper by L. Ambard, E. Pelbois and M. Bricka,82 who considerit to be just as much a unimolecular reaction as the hydrolysis ofsucrose by acids.The action of neutral salts is similar, accelerat-ing the latter, and making possible the former action (dialysedsaliva is without action on starch). In either case the action ofthe neutral salt is on the substrate, not on the catalyst. For starchthe action depends on the anion and is greatest for chlorides, a tP, 6.45, which gives also the reaction of a solution in which theamylase is most stable. Under these conditions the optimum con-centration of sodium chloride is 0.006 molar, but in this neigh-bourhood considerable changes in the salt concentration do notvery much affect the rate of hydrolysis.Potato tyrosinase has been separated by H. Haehn83 into twocomponents by means of a Bechhold ultra-filter.The residue isthermolabile " a-tyrosinase," the filtrate is an " activator " whichretains its activity after incineration. In the case of a successfulseparation (which is not always possible), the two components areseparately inactive on tyrosine, but become so when mixed.It is natural that attempts have been made to demonstrate thereversibility of hydrolytic action in such a simple and specific caseas that of urease, and H. P. Barendrecht,s4 in developing a radia-7 9 For example, Ber., 1919, 52, [B], 1594; A., i, 10.8 0 M. Jecoby, W. von Kaufmenn, A. Lewite, and H. Sallinger, ibid., 1920,Biochem. Zeitsch., 1920, 107, 268 ; A., i, 713.Bull. SOC. Chim. biol., 1920, 2, 42.Ber., 1919, 52, [B], 2029 ; A., i, 102 ; Biochem.Zeihch., 1920,105, 169 ;63, [B], 681 ; A., i, 424.hi., i, 777.a4 Proc. R. Akad. Wetewch. A m s t e r h , 1919, 22, 29, 126; A,, i, 102, 196.a170 ANNUAL REPORTS ON THE PROGRESS OF UHEMISTRY.tion theory of enzyme actions, claims that urease under certainconditions can transform ammonium carbonate into urea. Thisis denied by T. J. F. Mattaar.g5 I n any case urease undergoesmore or less rapid destruction in a solution of ammonium carbonate.E. Yamasakis6 has investigated the kinetics of urease and con-siders that the hydrolysis of urea is a simple catalytic action carriedon in the substrate phase and does not consist in the decompositionwith measurable velocity of an intermediate compound formedinstantaneously.Nor .do the enzyme and substrate form an inter-mediate compound with measurable velocity. The addition ofelectrolytes diminishes the activity of the enzyme owing to adsorp-tion by the latter, and the effect may in various cases be expressedaccording to Freundlich’s adsorption formula. Perhaps it is theelectrolyte nature of ammonium carbonate which prevents thereversibility of the urease action from being demonstrated.The same author 87 has compared the temperature-coefficientsfor the destruction of catalase from bamboo shoots, germinatedsoja beans and blood. As the coefficient is different in each case,he concludes that the enzymes are also different. The effect off‘poisons’’ is considered to be due to adsorption by and coagula-tion of the enzyme.C. G . Santesson8* also considers that theeffect of electrolytes on the rate of the catalase action is due toadsorption and finds that the anions can be arranged in Hof-meister’s lyotzopic series, SO, having the smallest and CN thegreatest inhibitory effect. C. Neuberg and F. F. NordB9 have ex-tended the reduction, by yeast, of the carbonyl group from alde-hydes to ketones. In the latter case they get optically activesecondary alcohols in yields of about 10 per cent. Diacetyl yieldsE-By-butylene glycol, whereas Harden and Walpole found thatbacteria produce from carbohydrates a mixture of the racemic andmeso-forms. Another interesting product of ferment action isthe crystalline specimen of sucrose obtained by E. Bourquelot andM.Bride1,go by the action of emulsin on gentianose. Previouslythis trisaccharide had only been hydrolysed to fructose and gentio-biose by invertase, and then the latter sugar could be split intotwo molecules of dextrose by “ gentiobiase ” of bitter almonds.The authors were, however, led t o attempt a different degradationby the simultaneous occurrence of sucrose and gentiobiose in fresh86 Rec. trav. chim., 1920, 39, 495 ; A., i, 649.8 6 Sci. Rep. TGhoku Imp. Univ., 1920, 9, 97 ; A., i, 577.87 Ibid., 1920, 9, 13, 69, 75, 89 ; A., i, 194, 453, 574, 576.8 8 Skand. Arch. Physiol., 1920, 39, 236 ; A., i, 576.89 Ber., 1919, 52, [B], 2237, 2248 ; A., i, 135.Bull. SOC. Chim. biol., 1920, 2, 160; Compt. rend., 1920, 171, 11 ; A.,i, 630PHYSIOLOGICAL CHEWSTRY.111gentian root. They finally succeeded by using a specimen ofbitter almonds as free as possible from invertase, and controllingthe length of the reaction polarimetrically .Estimation and Formation of Urea.Hypobromite does not liberate the whole of the nitrogen fromurea and the addition of substances like dextrose has been shownby M. Krogh91 t o give illusory results, since carbon monoxide isgiven off. L. Ambard92 now criticises Krogh's high results becauseoxygen is also evolved. After absorption of this gas by sodiumhyposulphite the nitrogen corresponds with 90 per cent. of thetheoretical. Apart from the use of urease, a more elegant methodof estimating urea is that given by R. F o s s ~ , ~ ~ which does notappear t o have received in this country the attention it deserves.It is based on the fact that xanthhydrol precipitates urea a t dilu-tions as high as 1 : 1,000,000.The method has been recently criti-cally examined and favourably reported on by Prenkel.94 Withits aid Fosse has lately studied the formation of urea by oxidisihgproteins with permanganate, first observed by BBchamp in 1856,but afterwards denied. Ordinarily only small amounts are pro-duced, but if the oxidised solution is subsequently heated withammonium chloride, much larger quantities of urea result,Q5 becausethe solution contains cyanic acid.96 When dextrose is added dur-ing oxidation the yield of urea is also much increased and smallquantities of dextrose alone, in the presence of concentrated am-monium hydroxide, may yield 70 per cent.of the sugar as urea.Q7The reaction is considered to proceed through the stages: formaldehyde, hydrocyanic acid, cyanic acid, ammonium cyanate, and itis suggested that this explains the formation of urea in plants.Under certain conditions a little oxamide may also be formed.9891 Zeitsch. phyriol. Chem., 1913, 84, 379 ; A., 1913, ii, 641.92 Bull. SOC. China. biol., 1920, 2, 205 ; A., 1921.93 Compt. rend., 1914, 158, 1076, 1588; 159, 250; A., 1914, ii, 506, 693,756 ; Ann. Reports, 1914,11, 178.94 Ann. China. anal., 1920, rii], 2, 234 ; A . , ii, 646. Compare also P. Carnot,P. GBrard and S . Moissonnier, Compt. rend SOC. Biol., 1919, 82, 1136 ; M.Laudat, ibid., 1920, 83, 730; A., ii, 645 ; W.Mestrezat and M. Janet, ibid.,1920, 83, 763 ; A . , ii, 645, 779.95 Compt. vend., 1919, 168, 320 ; A., 1919, i, 152.96 Ibid., 1919, 169, 91 ; A., 1919, i, 459.97 Ibid., 1919, 168, 1164; A . , 1919, i, 313.98 Compt. rend., 1920,171, 398; A., i, 664.a" 172 BNNUBL REPORTS ON THE PROGRESS OF CHEMISTRY.Hormones.During the current year several attempts have been made t oisolate the physiologically active principles of the pituitary body,but the position seems to be rather less hopeful than last yearwhen J. J. Abel and S. Kubota 99 suggested that the plain musclestimulant of pituitary might be identical with histamine. Thissuggestion was promptly rejected by D. Cow 1 and a t once reaffirmedby J. J. Abel and D. I. Macht.2 The attack and defence weremade on purely pharmacological grounds, and may be cited as anillustration of the difficulties involved in settling the identity ornon-identity of substances exclusively by their physiological action,without the chemical isolation of both.The differences in thephysiological behaviour of the two substances, used by Cow in sup-port of his argument, were considered by Abel and Macht to bethe result of differences in dosage. The notion that the pituitaryuterine stimulant (oxytocic principle) is merely histamine wasalso rejected on more chemical evidence by H. W. Dudley? whoextracted the dry powdered gland with acidulated water andpurified the extract with colloidal ferric hydroxide, which leavesthe active principle entirely in solution. It can then be removedcompletely without loss by continuous extraction with butyl alcohol(under reduced pressure, so as to lower the temperature). Thesubstance from pituitary is not identical with histamine, because,unlike this amine, it is destroyed a t room temperature byN-sodium hydroxide, and further, because it is destroyed bytrypsin, is extracted from acid solution by butyl alcohol, and isinsoluble in boiling chloroform.As the result of Dudley's experi-ments and later ones of their own, J. J. Abel and T. Nagayama4have had to abandon the hope that the pituitary uterine stimulantis histamine. They nevertheless claim that inf undibular extractsfrom fresh glands contain a little histamine, but much less thanextracts of commercial dried gland previously examined by them,or than the extracts commonly employed in therapeutics. Theysuggest that the specific active principle, on boiling and sterilisa-tion, partly breaks down t o histamine.The fact that they ob-tained an impure substance which is many times more oxytocicthan histamine itself, is in itself sufficient to dispose of theirprevious suggestion that the two are identical. It also makes thechances of isolation much smaller-evidently this pituitary prin-Ann. Rpports, 1919, 16, 158.Ibid., 279.lbid., 1920, 15, 347.J . Pham. Expt. Ther., 1919,14, 276.a Ibid., 296 ; A., i, 344PHYSIOLO~ICAL CHEMISTRY. 173ciple is a substance of quite extraordinary potency and present invery small amount.M. T. Hanke and K. K.Koessler5 go further than Abel andNagayama, and deny that histamine is present a t all in freshpituitary; they partly rely on a colorimetric method for estimatinghistamine,sa and they incidentally cite a number of chemical andphysiological differences between the amine and the pituitary prin-ciple. With regard to the latter, F. Fenger and M. Hull6 statethat in the fresh gland it is united t o a protein complex and isinsoluble in 95 per cent. alcohol, which, however, on boiling splitsoff a highly active, hygroscopic substance, more readily decomposedthan its precursor. Of late most writers, for instance, Dudley3and C. Crawford,7 consider the uterine and the pressor principle ofpituitary t o be distinc€. According to the latter, the pressorprinciple gives no Millon reaction and only a very doubtful Paulyreaction, but on keeping an aqueous solution it becomes reactivet o Pauly’s reagent. Abel and Macht find that the Pauly reactionis always given by active preparations. In spite of the greattherapeutical importance of the pituitary, the prospects of isolat-ing any specific active principle from it do not appear to be verybright.L. Stern and E. Rothlin 8 have prepared an impure substancefrom the spleen which they call ‘‘ li6nine”; it acts on smoothmuscle very much like histamine, and has some of the chemicalproperties of the latter substance. The chief difference appears t obe that lienine is destroyed by 1 per cent. sodium hydroxide, andhistamine is not. Of a number of organ extracts examined asregards their action on smooth muscle fibre, that of the spleen isby far the most potent and the active substance is stated to bepresent in the blood of the splenic vein. Further chemical workis required to prove or disprove its identity with histamine.Thyroxine was referred t o a t some length in last year’sReport. Since then a long paper by E. C. Rendall and A. E.Osterberg has come to hand, containing numerous microphobgraphs of crystals. Many analyses of thyroxine and its derivativesare now given for the first time, and the conditions governing thetransformation of the ketonic or lactam into the enolic or lactimform and into the open chain hydrate are discussed. It is statedthat the position of the three iodine atoms is determined byJ. Biol. Chem., 1920, 43, 557. Ba Ibid., 543 ; A., 784.F, Ibid., 1920, 42, 153.7 J. Pham Expt. Ther., 1920,.65, 81 ; A . , i, 468.* J. Phy8kl. Path. gdn., 1920, 18, 753 ; A., i, 649.a J. Biol. Chem., 1919,40, 265 ; A , i, 180174 m u & REPORTS ON THE PROGRESS OF CHEMISTRY.synthesis, a description of which is promised later. MeanwhileE. C. Kendall has further developed the estimation of iodine inthe thyroid; he thinks it best t o use only 0-5 gram of the gland.E. C. Kendall and F. S. Richardson10 find that there is 0.013 mg.of iodine in 100 C.C. of normal blood.GEORGE BARGER.10 J . Biol. Chem., 1920,43, 161 : A., ii, 631.PTOC. Iowa A c d . Sci., 1918,25, 495 ; A., ii, 445.Compare also S. B. Kuzirian

ISSN:0365-6217    

DOI:10.1039/AR9201700152

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.MUCH steady progress has to be reported, although no develop-ment of outstanding importance has occurred.The outlook for the future is in some directions rather uncer-tain. The Woburn Fruit Farm, long carried on a t the expenseof the Duke of Bedford, and made famous by the importantinvestigations of the late Spencer U. Pickering, will be closed:before this Report appears; and a t the moment of writing thereis the possibility that the Woburn Experimental Station of theRoyal Agricultural Society may be dosed in 1921, although somehope still remains that this misfortune may be mitigated, or evenaverted. It seems probable that the research in agriculturalscience done by Germany and Austria will be less,in future thanit was before the War.As against that, however, the Ministryof Agriculture in this country has produced an admirable scheme,whereby the research institutes can attract the ablest of theyounger men and women from the universities, and it may safelybe said that the institutes were never before as well staffed as theyare now. Both in amount and quality, the work in hand at thevarious centres of agricultural research in this aountry is full ofpromise for the future. Fortunately, also, in spite of the central-isation which is being forced by inexorable circumstances, therestill remain independent outside critics who can save the workersa t the institutes from the dangers of futility.Soil.It seems possible that the nature of the black organic matterin the soil, commonly known as ‘‘ humus,” will soon be understood.Humus is formed from cellulose in the soil; no great amountseems t o be obtained from the protein in plant residues.Maillardshowed some years ago that a substanoe resembling humus is pro-duced when sugar is heated either with mineral or amino-acids ;in the latter case, the “humus” contains nitrogen, as in soil.17176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The reaction has been further investigated by V. A. Beckley inthe Rothamsted laboratories; 1 setting out from an observation byFenton, he showed that sugars, on treatment with acids, give riseto hydroxymethylfurfuraldehyde, which readily condenses to forma substance closely resembling humus. He also found indicationsof the presence of hydroxymethylfurfuraldehyde in a dunged soiland in rotting straw in which humus was being produced.Hesuggests, therefore, that the formation of humus in soil proceedsin two stages:Carbohydrate (cellulose, etc.) + aniino-aoid =hydroxymethylfurfuraldehyde,Hydroxymethylfurfuraldehyde + amino-acid =humus + furfuraldehyde + CO, by condensation.An alternative view is put forward that humus is derived fromthe oxidation of quinones.2The humus has acid properties, which, however, are very difficultto measure. An interesting series of papers has been published3by S. Ode'n, of Upsala, one of the most ingenious of present-dayworkers on this difficult subject. He shows that selective absorp-tion, once invoked to account for the acidity, can really play buta very minor part, since treatment of washed peat with potassiumchloride solution gives no hydrochloria acid, but only non-volatileacids. Nor did iron or aluminium occur in the solution.Humicacid is a true acid ; 4 it appeared, however, from the high PR valueof peat extracts that other organic acids were present as well. Amethod is described for obtaining neutralisation curves which willprobably prove distinctly helpful to investigators.It is wellknown that large quantities of lime-one or two tons per aore-are necessary in order t o allow of the growth of agricultural cropson peat soils; whilst on normal soils much smaller quantities suffice.The usual explanation is that peat contains some harmful sub-stance put out of action by lime.Od6n shows that humic acidis so insoluble that it can hardly do much harm to vegetation; healso controverts Baumann and Gully's view that injury arises byabsorptive decomposition of nutritive salts with liberation of acid.Further, he demonstrates by the old van Bemmelen method thatlime effects no improvement in the fundamental water relation-He further discusses the effect of lime on peat.5J . Agric. Sci., 1930, 11, 69.W. Eller and K. Koch, Ber., 1920, 53, [B], 1469; A., i, 733.Int. Mitt. Bodenk., 1920, 9, 361; he has also published EL monographdealing with the whole question of humus : Roll. Chem. BeiheJte, 1929, 10,75. * For further confirmation, see F. Fuchs, Chem. Zeit., 1920, 441, 651 ; A.,i, 696.Int. Mitt. Bodenk., 1920,9, 376AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 177ships of peat. He concludes that humio acid is not itself harmfult o plants, but, on the other hand, the caloium humate formedwhen lime is added t o peat is distinctly beneficial, probably byacting as a “ buffer ” in regulating the hydrogen-ion concentrationof the soil. It would react with harmful acids, forming harmlesscalcium salts and insoluble, harmless humic acid, thus maintainingthe soil reaction suitable for plants and micro-organisms.He also describes a oolorimetric method for estimating theamount of humic acid in soil.6 The problem is complicated bythe fact that two intensely dark-coloured substances occur, namely,humic acid and the so-called hymatomelanic acid, in addition t othe faintly coloured acids formerly known as crenio and apocrenicacids, but named “fulvic” by OdBn.7As separation of the two dark-coloured acids is not easy, adetailed examination mas made of the absorption spectra of theirsodium salts as well as of that of Merck’s “acidum huminicum”;from the curves and data thus obtained the details of the methodare worked out.An aqueous extract of peat undergoes considerable changes onkeeping, which have been examined in some detail.8The organia phosphorus compounds of the soil have been studiedin Ohi0.9 About one-third of the total phosphorus in the surfacesoil and one-fifth of that in the subsoil is found t o be in this form,and this organic phosphorus is related both to the “humus solublein ammonia,” of which it forms about 1 per cent., and to the totalnitrogen, being one-tenth the amount of the latter.There was noevidence that the organic phosphorus compounds have much directnutrient value to plants, although they apparently undergodecomposition, since the amount in virgin soil is considerably abovethat in cultivated soil containing approximately the same quantityof total phosphorus.The black organic matter insoluble in alkalis is known as“ humin ” ; a similar-looking insoluble product is obtained by theinteraction of amino-aoids and tryptophan, tyrosine and formaldehyde.10Soil Acidity.-Much work continues to be done in America onIS Int. Mitt. Bodenk., 1920,9, 391.7 The multiplication of definite names for indefinite soil acids is confusing :it would be better to adopt the biological plan, and speak of ‘ A,’ ‘B,’ ‘(7,’etc., terms which can easily be discarded when more precise definition ispossible.H. Puchner, Kolloid Zeitsch., 1919, 25, 196 ; 1920,26, 159 ; A., i, 274,468.C.J. Schollenberger, Soil Sci., 1920, 10, 127.lo R. A. Gortner and G. E. Holm, J . Amer. Chem. SOC., 1920, 42, 632, 821 ;A., i, 400, 460178 ANNUAL REPORTS ON THE PROGRESS OR' OHBMISTRY.soil acidity. Four explanations have been offered of the powerof soil to turn blue litmus red: selective adsorption (Cameron),the presence of organic acids (Sprengel), of acid silicates (Hopkins,Loew), of easily hydrolysable iron or aluminium salts which arisewhen supplies of basic caloium and magnesium compounds arelow 11 (Abbott, Conner and Smaller, Daikuhara).The existence of a definite hydrogen-ion concentration in acidsoils shows the presence of definite acids, without, however, givingmuch information as to their nature.f2Aluminium nitrate and sulphate are both toxic to plants,especially clover, when applied in amounts equivalent to the acidityof the soil.Aluminium oxide and phosphate, on the other hand,had no effect.13 It was further found that washing soil with asolution of potassium sulphate or nitrate removed its acidity, andalso 59 per cent. of its aluminium. The leached soil was bettersuited for the growth of clover than the original acid soil. Addi-tion of lime or calcium phosphate also overcame the acidity andmade the soil fertile.These facts are all consistent with the viewthat aluminium is the toxic agent. It is further suggested thataluminium occurs as gibbsite, a form of aluminium oxide, readilysoluble in acids, which during nitrification or " sulphofication ,"becomes converted into nitrate or sulphate. The weak point inthe suggestion is that neither gibbsite nor other readily solublealuminium oxide has commonly been found in soils in temperateclimates, although it must be admitted that they have rarely beenlooked for.An interesting test for sour soils is based on the fact that ironalso, like aluminium, passes into solution when a potassium saltis added to a sour soil, but not when it is added to a normalneutral soil. Sourness therefore is readily detected by addingpotassium thiooyanate, and still better by using an alcoholic solu-tion of this substance.14Soil acidity is now measured by: (I) the lime requirement orpotassium nitrate extraction,l5 essentially titration methods indicat-l1 See L.P. Howard, Soil Sci., 1919, 8, 313; A., i, 416.l2 For further evidence of the chemical origin of soil acidity, see H. A. Noyes,J . Ind. Eny. Chem., 1919, 11, 1040; A., i, 211, and R. E. Stephenson, S o 4Sci., 1919, 8, 41; A , , i, 274. For details see E. T. Wherry, J. WashinytonAcad. ScE., 1920, 10, 217; A., ii, 400.Is J. J. Mirasol, Soil Sci., 1920, 10, 153; A., 1921, i, 88.I4 N. M. Comber, J. Agric. Sci., 1920, 10, 420.l5 H. G. Knight, J. Ind. Eng. Chem., 1920,12, 340 ; A., i, 468.For a studyof lime absorption by Indian soils and a method for muertaining lime require-ment, see F. J. Warth and M. P. Saw, Mem. Dept. Agria. India, 1919, 5, 157 iA., i, 416AGRIOVLTURAL ~ M I S T R Y AND VEQETABI;B: PHPSIOLOUY. 179ing the quantity of the acid; (2) the hydrogen-ion concentration(Sorensen’s PH notation is commonly used),ls measuring thestrength or intensity of the acid. On general grounds one wouldexpect no necessary relationship between these quantities. As amatter of fact, it is now suggested17 that they may be related,the observed inconsistencies arising from inaccuracies in the Veitchmethod commonly used in Amerioa, or from the presence of“ buffers.” Seeing, however, that “ buffers ” occur in all soils itwould appear that exceptions would be frequent.It has sometimes been asserted that the acidity of soil is toofeeble to cause injury t o plants, and the cause of the infertilitymust be sought elsewhere.A set of measurements made in West Virginia 18 give the follow-ing optimum PH values when phosphoric acid and sodium hydrateare the adjusting substances: seedlings of wheat, soja beans andlucerne, 5-94; seedlings of maize, 5.16.In more strongly acidsolutions of soja beans and wheat suffered little until the value fellbelow 5.16; although lucerne suffered a t once, 2.96 seems t o bebelow the critical value, and 2-16 was fatal to growth (although notto germination) and favoured the growth of moulds in the oultures.Some injury was observed when the neutral point was attained andconsiderable injury when it was passed ; alkalinity apparently ismore harmful than acidity.Other measurements have been madewith lucerne a t New Jersey, sulphuric acid and calcium carbonatebeing here the adjusting substances. Germination was practicallyunaffected between PR values 4.5 to 7.0; below 4.5, however, it wasmuoh retarded.19 The yield showed a steady increase between P,values 3.8 to 6.5, with some irregularities between 6.5 and 8.More measurements of this kind are needed ; these results suggestslight acidity as the optimum condition, whereas long agriculturaltradition favours neutrality attained by use of chalk or lime.There is one case, however, where slight acidity is known tobe desirable-the potato crop, which becomes liable to “scab ” ifthe P, value is too high.Gillespie gave 5.2 as the limiting value;a case is now known, however, where “scabbing ” occurred at 4.8,although it was much reduced in comparison with the control plota t 5.6.20 Acidification had been brought about by the addition ofsulphur, which oxidises in the soil t o form sulphuric acid. Thismethod of controlling soil reaation promises to be of much interest.The student will find a full account of this method and a critical discus-sion by E. A. Fisher in J . Agric. Sci., 1920,11, 19,I f A. W. Blair and A. L. Prince, Soil Sci., 1920, 10, 253.ly J. 5. Joffe, Soil Sci., 1920, 10, 301.R. M. Salter and T. C. McIlvaine, J . Agric. Res., 1920, 19, 73.I0 W. H. Martin, ibid., 1920,9, 393180 ALMQUBL REPORTS ON TEE PROGRESS OF CHEMISTRY.Attempts have been made to ascertain in what way the acidityinjures plants.The acidity of the sap corresponds with values5-48’ to 5.97 in buckwheat seedlings, and 4.82 in the adult plant;%’there is also considerable reserve acidity.These figures may be of the same order as those for optimumconditions in the soil. Some of the results lend colour to the sug-gestion 22 that the harmful effect of soil acidity exceeding thesevalues is due to its influence in preventing plants from securingrapidly enough the bases necessary for neutralisation and precipita-tion of acids within the plant; in general, also, the addition of limeto the soil deareases the acidity of the plant juice.The present position cannot be better described than in thewords of D.R. Hoagland,B one of the foremost investigators ofthe modern aspects of soil problems :“ I n perhaps the majority of cases the inhibition of crop growthfrequently associated with acid soils may not be the direct effectof the acidity a t all. In other factors, such as soluble aluminium,may be found the true direct cause of the injury. It is grantedthat these causes may be removed by exactly the same treatmentwhich neutralises the acidity, but in the interest of saientific pro-gress it is essential to separate and designate the various factorsand their inter-relations.“Is it not possible that the whole subject would become clarifiedif we attempted to reach such definite conclusions as: ‘ The growthof the crop is inhibited by too great concentration of hydrogenion, or by too large a concentration of aluminium ion, or by toolow a level of calcium in the soil solution, or by the effect of thehydrogen-ion conaentration on the soil micro-organisms, etc.’ ? ”Methods of Increasing the Stock of Organic Matter in the Soil.Considerable attention has been given to green manuring as ameans of increasing the supplies of organic matter in the soil.Emphasis has again been laid on the value of leguminous crops,and some precise data have been accumulated.24 Attempts (unf or-tunately not giving very definite results) have also been made toascertain whether or not soil acidity is increased thereby.%Further evidence is published that in Virginia, as elsewhere, thegrowing crop temporarily restricts nitrification in soil, soja beansbeing an exception.2621 A.R. C. Haas, So2 Sci., 1920, 9, 341.24 E. Truog, ibicl., 1918, 5, 169.34 T. L. Lyon, J. A. Bizzell, and B. D. Wilson, Soil Sci., 1920,9, 53.25 L. P. Howard, ibid., 27.za Private communication.26 R. C. Wright, ibid., 1920, 10, 259AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 181Soil Organisms.The effectiveness of leguminous orops arises from the fact thatthey are associated with micro-organisms capable of fixing gaseousnitrogen and converting it into substances available for the nitro-genous nutrition of the plant. These remarkable organisms havebeen the subject of much investigation; a life-cycle has been sug-gested,27 for which there is considerable evidence.Five stages aredescribed : a small non-motile form, a larger non-motile coccus,an elliptical highly motile form (this being the swarmer stage ofBeijerinck), a rod form, and finally, when the carbohydrate supplyis exhausted, a vacuolated stage. A neutral reaction and thepresence of calcium phosphate speed up the change from non-motileto motile forms. This work is being continued.Some interesting work on the general biological relationships isbeing done in Professor A. L. Whiting’s laboratory in Illinois.The process of nitrogen fixation was not adversely affected bynitrate or by organic matter; indeed, in the case of cow peasthere was some evidence that the addition of organic matterincreased it .28Another important practical problem has been studied : whetherthe organisms are the same for all leguminous plants or whetherthere are special strains for each kind.Some degree of specificityis proved: the organism of lima bean (Phaseolus lirnatus) isidentical with that of cow pea and will inoculate either crop, butit is distinct from that of navy and kidney beans (Phaseolusvulgaris), and will not inoculate these.29Soja beanstake up these compounds readily from the soil; indeed, the con-oentration of nitrate in the cell sap becomes greater than in thesoil solution, and so high as to inhibit growth and reproduction ofthe organism there.30In addition to the fixation of nitrogen, bacteria play an importantpart in breaking down the protein contained in plant residues andproducing nitrates needed for plant nutrition.Further data havebeen collected in New Jersey showing that the productiveness isclosely related to the rate of evolution of carbon dioxide (described)as “oxidising power”), and to a less extent to rate of nitrateaccumulation and bacterial numbers.31In a suggestive paper, which may foreshadow important develop-Nitrates have a marked effect on nodule production.27 W. F. Bewley and H. B. Hutchinson, J . Agric. Sci., 1920, 10, 144.28 W. A. Albrecht, Soil Sci., 1920, 9, 275.A. L. Whiting and R. Hmsen, ibid., 1920,10, 291.W. H. Strow-d, ibid., 343. 91 J. R. Neller, aid., 29182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ments, Gillespie draws a distinction between oxidations of highpotential and those of low potential in a soil.s2 A given.rate ofabsorption of oxygen or production of carbon dioxide may arisefrom an oxidation of high intensity or potential involving a smallquantity of material, or a reaction of low potential involving mu&material. The phenomena are parallel to those of the hydrogen-ion concentration, and simultaneous development of both aspectsof the subject may be expected.Further work has been done on the protozoan fauna of the soil,and a t last it appears that this subject is being put on a soundbasis. The method of estimating the numbers of protozoa innatural soils has been greatly improved by D. W. Cutler a tRothamsted ;33 active forms can now be distinguished from cystsand separated out into a number of different species.The firstsystematic census34 was taken a t intervals of ten days, and theresults when plotted, whilst definitely indicating certain relation-ships, showed many fluctuations which were difficult to understand.A daily count of the organisms in a field plot was thereforeorganised, and it revealed some remarkably interesting phenomena.The numbers of bacteria were always inversely proportional tothe numbers of active amaebs, whilst the numbers of flagellatesshowed a remarkable periodicity which is not yet explained. Theresults35 are so important that tlie daily census is being continuedfor 365 consecutive days. American investigators have sometimesclaimed that protozoa were absent or unimportant in Americansoils, which if true would’ indicate a great difference in micro-organic flora in this country and America.Using a less completemethod of counting, it is now recognised that in the soil of NewJersey there is a ,fauna of organisms ‘‘ which are practically alwayspresent in the soil in considerable numbers and which use the soil asa medium in which to live and carry on their life processes.” Thefauna, however, is believed to exist mainly in the non-trophicstate.36 It seems highly desirable that an extended quantitativesurvey should be made in a t least as comprehensive a manner as isdone at Rothamsted, discriminating carefully between active formsand cysts; there appears to be no simple direct method of doingthis short of actual counts.Advances in soil microbiology have shown that the soil popula-tion is more complex than was a t one time thought, but it is alsoknown that some degree of simplification often increases productive-3p L.J. Gillespie, Soit Sci., 1920,9, 199.33 J . Agric. Sci., 1920, 10, 135.35 D. W. Cutler and L. M. Crump, Annals of Applied Bwl., 1920,7, 11.86 C. R. Felleria and F. E. Allison, SoiZ Sd., 1920,9, 1.84 L. M. Crump, ibid., 182AURICULTURAL CHEMISTRY AND VEUETABLE PHYSIOLOGY. 183ness. Simplification is obviously advantageous when diseaseorganisms or pests are present. Some organisms tend normally todisappear in the general competition ; the Yseudomonas citri caus-ing citrus canker in America is rapidly exterminated fromordinary soil, although it flourishes in sterilised soil? In othercases, however, competition alone is insufficient and direct controlis attempted.Heat is found to be effective, but its application israrely feasible. Recourse is therefore had to chemical methods,and substances are sought which, whilst toxic to the organism inquestion, will not injure the plant. This necessary limitation rulesout most inorganic poisons, such as arsenic compounds, mercurysalts, etc., and restricts investigators to organic substanoes.Applications to the soil of calcium sulphide and naphthalene orcymene lead to much increase in the crop and also in numbers ofB . butyricus, although on fallow soils this particular anaerobicorganism does not develop, but there is a loss of nitrogen.38In seeking for new agents the first step is to ascertainthe effect of various groupings on toxicity.In the caseof the wireworm 39 aromatic compounds are more toxicthan aliphatic compounds, and the toxicity is successfully increasedby the addition of methyl (the least effective), halogen, hydroxyl,or methylamino-groups (most effective). Substitution in the side-chain is more effective than in the ring. The effect is not additive,however; position and other groups both exert great influence.The association of chlorine and nitro-groups is particularly potent,and chloropiarin is one of the most lethal agents tested. In seriesof compounds of the same chemical type there is a fairly close rela-tionship between toxicity and vapour pressure, rate of evaporationand volatility, toxicity increasing as the volatility decreases, untilfinally, a limit is reached when the vapour pressure sinks too lowto allow of the attainment of a toxic concentration.Somewhat similar, although less extensive data, are recorded) withParamoecium .40A substance highly toxic to the organism, however, will notnecessarily suppress it in the soil, as the soil population indudesorganisms able to effect remarkable decompositions, for example, tobreak down such unlikely substances as phenol, cresol, and appar-ently even naphthalene and more stable ring compounds.Owing37 H. A. Lee, J . Agric. Sci., 1920, 19, 189; H. R. Fulton, ibid., 207.38 G. T d a u t and N. Bezssonoff, Compt. r e d ., 1920,171, 268 ; A., i, 655.sg F. Tattersfield and A. W. R. Roberts, J. Ag&. Sci., 1920, 10,199. Amongpossible agents, trichloroethylene deserves consideration : E. Salkowski,Biochem. Zeitsch., 1920,107, 191 ; A., i., 794, shows that it is cheap, volatile,and effective.‘O N. McCleland and R. A. Peters, J . PhysiOZ., 1919, 53, Xii, xv ; A., i, 512184 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY.t o the smallness of the amounts involved and the complex natureof soil, it is difficult t o ascertain the course of the decomposition,but some help may be obtained from the work of chemists on thecatalytic oxidation of simple but stable organic compounds.41The case of vanillin has been studied in some detail.*2 Thissubstance has been isolated from s0ii,~3 and it is toxic t o plants;it is, however, decomposed by certain soil bacteria.Apparentlyonly a limited number of organisms have this power. It is obviousthat micro-organisms capable of breaking down potential planttoxins are of importance in soil fertility.A further unexpected change apparently brought about bybacteria is the oxidation of the element sulphur when added to thesoil. This was first demonstrated in 1916,44 and’ was turned topractical account in the conversion of mineral ph Tsphates intosoluble phosphate in compost heaps or in the soil. Further detailsare now worked out, and it is shown that nitrification still pro-ceeds in spite of the formation of acid.45An interesting observation has been made in Egypt t o the effeotthat the fallow or “sheraqi” is a period of biological inactivityin the soil, but is followed by a period of increased activity, thephenomena being apparently parallel to those shown during partialsterilisation of the ~0il.46In some cases, probably in many, a reaction is brought aboutby a chain of agencies, chemical and biological.Thus, calciumcyanamide is a well-known fertiliser, but it owes its effectiveness tothe ammonia produced in its decomposition. The first stage is theproduction of carbamide ; this is apparently non-biological, since itoccurs even after the soil is heated to 135O; the decomposing agentis not yet identified, although the change can be brought about bycertain zeolites which may occur in soil. The second stage is theformation of ammonia from the carbamide; this is biological andcan be effected by numerous micro-~rganisms.~~An improved method, of determining ammonia in soil has beendeveloped.#41 For example, paraf6ns: A. Griin, Ber., 1920, 53, [B], 987; A., i, 518;benzene: J.M. Weiss and C. R. Downs, J . Id. Eng. Ciaem., 1920, 12, 228;A., i, 426.44 W. J. Robbins and E. C. Lathrop, Soil Sci.. 1919, 7, 475; A., i, 265 ;W. J. Robbins and A. B. Massey, ibid., 1920, 10, 237 ; A., i, 913.E. C. Shorey, J . Agric. Res., 1914, 1, 357 ; A., 1914, i, 916.44 J. G. Lipman, H. C. McLean, and H. C. Lint, So4 Sci., 1916,2, 499. Forbibliography, eeeH. C. McLean, ibid., 1918, 5, 251.45 0. M. Shedd, J . Agric. Res., 1919, 18, 329.46 J. A. Preacott, J . Agric. Sci., 1920, 10, 177.47 G.A. Cowie, ibid., 163; A., i, 655. 4s D. J. Matthews, ibid., 72AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 185The effect of water supply on bacterial aotivity has been studiedand some useful curves have been drawn; relationships have alsobeen traced with some of the Brigg's and' Hilgard's c0nstants.4~Relation of Soils t o Plant Growth: Water Supply.One of the most important functions of the soil is t o supply watert o the plant. This problem has been extensively studied by Living-stone, and he now contributes an important suggestion that mayhelp materially in elucidating the very complex phenomena con-cerned.50 The fundamental conception is t o regard the soil as amachine delivering water to the absorbing surface of the plantroots; the purpose of the investigation is to study the water-supply-ing power of the soil.The problem is regarded dynamically,although, of course, it depends on a number of statio conditions,such as sizes, kinds, and arrangement of the soil particles, and thewater content per unit volume. The experimental method consistsin embedding porous porcelain cones in the soil, then after a suibable time withdrawing them and weighing to measure the absorbedwater. Special attention is paid t o the region of moisture contentswhere wilting occurs. It appeared from the data obtained(although the authors frankly recognise their preliminary nature)that the water-supplying power a t the wilting point was approxi-mately the same for all the twelve soils examined.This criticalvalue is, of course, not to be regarded as a constant for all kinds ofplants and all degrees of evaporation, any more than is the wiltingcoefficient of Briggs and Shantz, which varies in a regular andpredictable way for any given soil and plant with the evaporatingpower of the air.61 I f further investigation confirms the view thatthe value is indepentdent of the physical make-up of the soil andis the same for sand, loam and humus, it will undoubtedly proveof importance.The power to supply water, however; is dependent on the amountpresent, and this is the balance of gains over losses. The loss ofwater from the soil takes place partly by drainage and partly byevaporation. It is claimed that the rate of evaporation isdiminished on addition of soluble salts, and the diminution isdirectly related to the osmotic concentration of the soil solution.@The water relationships for soils are very complex, and a valuablecritical resume of the whole subject has been made by Eeen.5349 J.E. Greaves and E. G. Carter, Soil Sci., 1920, 10, 361.B. E. Livingstone and R. Koketsu, ibid., 1920,9, 469.61 J. S. Calawell: The relation of environmental conditions to thephenomenon of permanent wilting in plants, Physiol. R c ~ . , 1913, 1, 1.M. I. Wolkoff, SoiZ Sci., 1920, 9, 409; A., i, 803.68 B. A. Keen, J . Agric. Sci., 1920, 10, 44186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.An attempt has also been made to analyse more closely thecapillary movement of water through soil.54An important factor, determining not only water supply, buttilth, ease of working the soil, and other properties, is the degreeof flocculation of the finer particles.I n practice, lime is used toeffect this change, but the phenomena (do not altogether fall inline with those ordinarily observed with colloids. Some of theapparent contradictions are elucidated in a very suggestive paperby Comber. “Silt,” the fine but not the finest material in thesoil, is most easily flocculated by calcium salts when the suspensionis neutral ; this is the usual behaviour of insoluble substances.On the other hand, ( I clay,” the finest material, is most easilyflocculated in alkaline suspensions. This is unusual for insolublesubstances, but is shown by silicic acid and some of the so-called“emulsoid” colloids.It is suggested that clay as an emulsoidprotects the larger particles, which by themselves are suspensoid,and causes the whole soil to be flooculated by lime. I n absence ofclay, however, lime does not effect flocculation.55Alkali Soils.Under conditions of low rainfall, salts of sodium may accumu-late in soils and produce sodium carbonate by various interactions,which are not yet fully understood.56 It is suggested that thesulphate may in some cases be reduced to sulphide, which is thendecomposed by carbon dioxide to form the carbonate.57However they are formed in the soil, the harmful effeots ofsodium carbonate, sodium chloride, and other salts on plants andon organisms causing ammonification and nitrification are over-come by the addition of calcium sulphate.I n the case of micro-organisms, ferric chloride and sulphate are also eff ective.58Doubt is now thrown on the current values for the toxicity ofthese salts in soils. It is shown that soil absorbs more water froma solution of sodium carbonate than from an equivalentsolution of sodium chloride, and therefore, under conditionsapparently comparable, the plant root would be in contactwith a more concentrated solution of carbonate than of thechloride. This fact is said to have been overlooked, and to have54 W. Gardner, Soil Sci., 1920, 10, 103, 357.3 N. M. Comber, J . Agric. Sci., 1920, 10, 425. For other experiments, see56 For a recent discussion, see A.de Dominicis, Staz. sper. agr. Ital., 1918,57 E. Pozzi-Escot, Bull. SOC. chim., 1919, [iv), 25, 614; A., ii, 185.5g J. E. Greaves, Soil Sci., 1920, 10, 77.0. M. Smith, J . Amer. Chem. SOC., 1920, 42, 460; A., ii, 296.51, 103 ; A., i, 414AGRTCULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 187led to false conclusions as to the relative toxicity of thesesubstances.69Other Investigations.Further experiments are reported showing that calcium sulphateincreases the amount of soluble matter in soils.6O The amount ofwater-soluble material in the soil is not greatly affected by normalvariations from the mean moisture content, but it is reduced whenair-dry or water-logged conditions are attained.61Work on the drift soil of the Craibstone Farm has been con-tinued .62 This soil is largely composed of disintegrated granite.Like other soils, it has a marked power of absorbing ammonia, andthe property is not shown by all constituents alike, but chiefly bythe finer fractions.Powdered granite shows similar powers ofabsorption. It is not necessary to assume, therefore, that absorp-tion is effected only by decomposed material. Absorption isdecreased after ignition.Fertilisers.Following the practice of the previous years, the technical aspectsof this part of the subject will be discussed in the Report to theSociety of Chemical Industry, and only a few of the papers ofscientific interest will be referred to here.Two summaries of long-oontinued field experiments have beenissued. I n the New Jersey experiments, the best results were givenby sodium nitrate on the unlimed, and ammonium sulphate on thelimed, plots, whilst the organic manures (dried fish, dried blood,and tankage) were less effective. No more than one-third of theadded nitrogen was recovered in the crop, and, in absence ofleguminous plants, there was no accumulation of nitrogen in thesoil, but, on the contrary, a ~OSS? I n the Ohio experimentssummarised by Director Thorne, very similar results were obtained ;sodium nitrate proved better than ammonium sulphate on unlimed,but not on limed, soils, and both proved better than tankage.64One case is reported, however, where an organic manure provedmore effective than others, namely, that of the American ‘‘ blue-berry.” Sodium nitrate by itself somewhat depressed the yield ;59 T.H. Kearney, Soil Sci., 1920, 9, 267 ; A., i, 588.6o M. M. McCool and C. E. Millar, J . Agric. Rw., 1920,19, 47 ; A., i, 588.61 J. C. Martin and A. W. Christie, ibid., 1919, 18, 139.62 W. G. Ogg and J. Rendrick, ibid., 1920, 10, 333, 343.63 J. G. Lipman and A. W. Blair, Soil Sci., 1920, 9, 371.G4 C. E. Thorne, {bid., 487188 ANNU& REPORTS ON THE PROGRESS OF CHEMISTRY.complete artificial manure somewhat increased it, but a mixture ofthe latter and dried blood considerably increased it. Themanuring of fruit has, however, always been a subjeot of somedifficulty, bristling with exceptions to all the rules.65In all fertiliser work, it is necessary t o carry out field trials,and, in spite of their apparent simplicity, they are liable to manysources of error.A useful summary has been prepared: of themethods by which the more serious errors can be avoided, specialstress being laid on Larsen's method.66 .The effect of magnesium carbonate on plant growth is a subjectof much practical importance; a persistent idea is current amongpractioal men that it is in some way harmful to crops, and, inconsequence, magnesium limestone is not held in high repute.Many experiments have been made. Recently, in Indiana, magne-site proved more favourable than caicite for nitrification and formultiplication of aerobic and anaerobic bacteria on a yellow claysoil, but not on a black soil; it produced a greater increase insoluble salts in the soil, and led t o larger increases in yield of beet,but smaller increases of wheat and clover, than did oalcite.67 Onthe other hand, i t is elaimed that full crops are not obtainable onsoils where magnesia is in excess of lime.s8Plant Growth.The nutrient salts absorbed by plants from soil, together withthe carbon dioxide assimilated by their leaves, are elaborated intothe complex constituents and contents of the plant cells.Theprocesses involved continue to form the subject of much investiga-tion. The relationships between absorption of salts by the plantroot and composition of the nutrient medium is being studied a tthe California Experimental Station, where, in the case of barley,three distinct phases in the absorption of the nutrients werefound.69 Up to the time of formation of the head, the rate ofabsorption progressively increases until, finally, the amounts ofnitrogen and of potassium reaoh a maximum.The second phasecorresponds with the translocation of material into the developingheads; this is marked, not only by a decreased rate of absorptionfrom the soil, but by definite and substantial losses of nitrogen,potassium, and apparently calcium from the aerial parts of the65 C . S . Beckwith, SoiZSci., 1920, 10, 309.66 J. Sebelien, J . Agric. Sci., 1920, 10, 416.$7 S. D. Corner and H. A. Noyes, J . Agric. Rea., 1919, 18, 119.68 J. Hughes, J . Bzth and W. and S. 00. Soc., 1919, [v], 13; A., i, 416.69 J. S. Burd, J . Agric. Res., 1919,18, 61ABBRICULTURAL CHEMISTRY AND VEGETABLE mYSIOLOBBY.189plant, and presumably from the whole plant, although difficultiesof manipulation make root examination uncertain, Towards theend of the period, the lost materials are regained. The final stageis ripening, during which absorption ceases and losses are resumed.It is suggested that these movements of salts into and out fromthe plant may be due t o purely physical causes, as low concentra-tion of the water extract of the soil occurs simultaneously with themovement out from the plant. The results suggest that the normalrelationship between plant and soil is to have a relatively high soilconcentration in the early stages of growth and a low ooncentrationin later stages.Reference has been made in earlier Reports t o the work of Shiveand Tottingham, in which it is claimed that plants need not onlyan adequate supply of various nutrient substances, but also somekind of relationship or “ physiological balance ” between the par-ticular elements.The data show considerable variations, but theratio of nutrients causing maximum growth is called the optimumratio. This ratio is found t o alter with the concentration of thenutrient solution; it is not the same a t 0.1, 1.75, and 4 atmo-spheres,70 but it is unaffected by the nature of the medium, beingthe same in sand as in water culture. So also it is independent ofvariations in the moisture oontent of the sand, and is the same fordegrees of moistness varying from 40, 60, to 80 per cent. of thewater-retaining capaoity of the sand.It is not, however, constantfor the whole range of growth of the plant, being different inseedling and adult stages, and different for the growth of. “top”and of the roots.Closely associated with this conception of physiological balanceis that of antagonistic action between ions. Wheat seedlings areadversely affected by sodium ohloride and sodium sulphate, but thetoxic effects are largely overcome by small amounts of calciumoxide or calcium sulphate, and t o a less extent by magnesiumsulphate and barium chloride. The lime did not prevent theentrance of the sodium salts into the plant; its antagonistic effectwas therefore not attributable t o any reduction of permeability.71Calcium salts also enable the plant t o overcome the harmfuleffects of copper salts, although they do not prevent the entry ofcopper into the plant.It is considered more probable that thecalcium favours the evolution of the plant, giving it greater vigour,and in particular greater volume, into which the copper diffuses,thus preventing dangerous accumulation in any one region .7370 J. W. Shive, J . Agric. Rm., 1920,18,357.‘I L. Maquenne and E. Demoussy, Compt. rend., 1920,170,420; A., i, 857.J. A. LeClerc and J. F. Breamale, ibid., 347; A., i, 413190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Attention has, however, been directed to the possibility thatcertain ions may alter the plasma colloids 73 or the permeabilityof the plant cells.74 Ferrous salts are known t o be more injuriousto young plants than ferric salts, and therefore any conditionwhich favours their oxidation reduces the toxic effects. It is shownthat monopotassium phosphate and copper sulphate both have thiseff ecL75 Neither manganese sulphate nor chromium salts were foundeffective as f ertilisers.76The functions of the various nutritive elements are determinedindirectly. Some work has been done this year on calcium.77There seems to be a close relationship between the calcium andnitrogen content of plants, and the more important crops can bedivided into two groups: (a) those with low content of calciumand nitrogen, a low calcium-nitrogen ratio, and low lime require-ments; ( b ) those with high content of calcium and nitrogen, highratio, and high lime requirement.It is suggested that proteinmetabolism is probably one of the ahief sources of plant acids, andmay give rise t o the need for calcium.The question whether silicon is necessary for plant nutrition hasbeen raised. An artificial calcium silicate was tested againstcalcium carbonate, and found to be in no way superior. Itappears, therefore, that silicon in this compound is of no advantageto the growing crop.78An interesting and entirely novel suggestion as to the functionof potassium in plants has been brought forward. It is claimedT9that the potassium ion may, as regards function, be replaced byall the other radioaotive elements, heavy or light, provided thedoses are equiradioactive; it may also be replaced by a free radio-active radiation.Some attention has been given to the action of copper salts onvegetation.It is shown that copper is a frequent, and possiblya normal, constituent of plants.80 It is claimed, in spite of7s T. Tadokoro, J . ColE. Agr. %okkaido. Imp. Univ., Sapporo, Japan, 1919,8, 143; A., i, 585; S. M. Neuschlosz, Pjliiger’s Archiv, 1920, 181, 17; A.,i, 698.74 0. L. Raber, J. gen. Physiol., 1920, 2, 535, 541 ; A., i, 585, 586.75 L. Maquenne and E. Demoussy, Compt. rend., 1920,171, 218; A , , i , 654.76 T. Pfeiffer, W. Simmermacher, and A. Rippel, Fuhlings Landw. Zeit.,1918, 313 ; A., i, 652 ; F. Weis, K. Vet.-Landboh6jskole Aarsskrijt, 1919,239 ; A., i, 652.77 F. W. Parker and E. Truog, Soil Sci., 1920, 10, 49 ; A., i, 702.78 B. L. Hartwell andF.R. Pember, ibid., 57.79 H. Zwaardemaker, J. PhySiol., 1920, 53, 273 ; A,, i, 511 ; Pfliiser’e Archiv,80 E. Fleurent and L. L6vi, BuU. SOC. c h h . , 1920, [iv], 27, 440, 441 ; A.,19 18,173, 28 : A., i, 345.i, 584AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 191previous work to the contrary, that dilute solutions of coppersulphate added to water cultures have a favourable action on thegrowth of roots and stems of peas and wheat.81Theoretical discussions have been attempted 82 of the physico-chemical basis of the phenomena of absorption and elaboration ofnutrient salts, and of the effects of these salts on cell division.83For many years i t was supposed that nitrates, phosphates, andsimple salts of potassium, calcium, magnesium, etc., were alonenecessary to plant growth, no organic compound of any kind beingrequired.Recently i t has been asserted that certain organiccompounds are helpful, if not necessary, and lead to markedincreases in growth. The case of Lemma major has been studiedin London ; crude nucleic acid derivatives from bacterised peat,the growth products from Azotobacter chrococcum and Bacillusradicicola, leaf mould, fresh and well-rotted stable manure, andwell-manured fertile soil all contained water-soluble substanceswhich promoted the growth of this organism.84 I n California,dilute extracts of peat (10 parts in 1,000,000 of water) produceda marked stimulation of root growth of citrus seedlings,85 whichcould not be obtained with oorresponding solutions of sodiumnitrate or potassium chloride.On the other hand, bouillon pre-pared from fresh brewers’ yeast, which had been heated to 1 3 5 Oand rendered incapable of curing polyneuritis in pigeons, was stilleffective in improving the growth of fungi.86Assimilation.-The ease and rapidity with which the plant insunlight absorbs carbon dioxide and converts it into sugar hasalways been a source of wonder to chemists, who have never yetbeen able to reconstruct the process.Support is periodically forthcoming for Baeyer’s old hypothesis ;it is claimed87 that formaldehyde can be absorbed by plant leavesand transformed into plant tissue. There are, however, diffioultiesin the way of this hypothesis, and another has been put forward,which is claimed to be more in accordance with the facts.Thefirst stage is supposed to be the isomerisation of carbon dioxide,with the formation of a secondary peroxide, >C<g2H ; thisL. Maquenne and E. Demoussy, Compt. rend., 1920, 170, 1542; A.,i, 584.aa E. Reinau, Zeitsch. Elektrochem., 1920, 26, 329; A., i, 799.83 J. Spek, Koll. Chem. Beihefte, 1920, 12, 1 ; A., i, 853.84 W. B. Bottomley, Proc. Roy. SOC., 1920, [B], 91, 83; A., i , 265; I?. A.Mockeridge, Biochem. J., 1920,14, 432 ; A., i, 704.35 J. F. Breazede, J . Agric. Res., 1919, 18, 267.96 A. Lumibre, Compt. rend., 1920,171, 271 ; A., i, 652.M. Jacoby, Biochem Zeitsch., 1919, 101, 1; A., i, 800192 ANNUAL REPORTS ON WitE PROQRESS OF CHEMISTRY.HO-C-OH o=c=o HO-C-OH ‘..*+2H, 0 + --t s*j\..*HO-b-OH HO-C-b o=c=oH eliminates oxygen and yields the group which is pre-+o,88 G.Woker, PfEiiger’s Archiv, 1919,176, 11 ; A., i, 354.*@ P. R. Kcgel, Zeitsch. wise. Photochem., 1920, 19, 215; A., i, 355.go 0. Warburg, Biochem. Zeitsch., 1919, 100, 230; 1920, 103, 188; A.,91 R. Wurmser, Compt. rend. SOC. Biol., 1920, 83, 437 ; A., i, 560.92 K. Stern, Ber. Deut. bot. Ges., 1920, 38, 28; A., i, 700.93 E. Reinau, Chem. Zeil., 1919, 43, 339; A., i, 128.94 W. J. V. Osterhout, Bot. &z., 1918, 68, 60; A,, i, 128.96 M. B. Cummings and C. H. Jones, Bull., 1919, 211, 56 pp.; A., i, 267.i, 583, 798.See also F. Riedel, Stahl tcnd Eben, 1919,39, 1497AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 193carbamide,gG and it is certainly true that assimilation usuallyproceeds in this way.Periodioally, it has been assumedl thatgaseous nitrogen might be assimilated by higher plants, but thepossibility has not been taken seriously by physiologists. It isknown, however, that certain bacteria can effect this assimilation,and from gaseous nitrogen and carbohydrates can synthesis0 cellproteins; but these bacteria have no power of synthesising carbo-hydrates: they are dependent on pre-formed sources of thesematerials. Moore has made the interesting announcement thatcertain unicellular alga possess the power of fixing, not onlygaseous nitrogen, but carbon also, so that they can by themselves,and without pre-formed carbohydrates, construot the wholeorganic contents of their ~ells.~7 I f this result is confirmed, it willalter some of the fundamental conceptions of soil microbiology andplant physiology.The Growth of Plants: Effect of Light and Temperature.-Investigators dealing with the growing plant are soon compelledto realise the dominating effect of factors other than the supplyof plant nutrients.The rateof growth is directly proportional t o the length of the day, andthis factor also profoundly affects the sexual reproduction ofplants; in many species the flowering and fruiting stages can beattained only when the length of day falls within certain limits,for example, in natural conditions only during certain seasons.g*I n absence of sufficient day length, vegetative growth may continuemore or less indefinitely, thus leading t o the phenomena ofgigantism; or, on the other hand, under the influence of suitableday length, precocious flowering and fruiting may be induced.I nsome cases, a day length was found suitable both to vegetativegrowth and reproduction ; an ever-blooming or ever-bearing habitwas then obtained. By suitable variation of the length of day, itwas possible to give annuals a perennial habit, or, on the otherhand, t o hasten their processes, so that they would go throughtwo cycles of alternate vegetative and reproductive activity in oneseason. Variations in intensity of light had little effect, thenormal intensity, as shown by H. T. Brown, being more thansufficient for the needs of the plant.Moisture supply and temperature are equally important factors :these have been invoked t o explain the stunted growth in wind-One of the most important is light.% T.Bokorny, Pfliiger’s Archiu, 1918, 172, 466; A., is 413, shows that97 B. Moore and T. A. Webster, PTOC. Roy. Soc., 1920, [B], 91, 201; A.,O* W. W. Garner andH. A. Allard, J . Agric. Res., 1920,18, 563.REP.-VOL. XVII. Hcarbamide is utilisable in proper conditions.is 466194 ANNUAL REPORTS ON THE PROGRESS OR' CHEMISTRY.swept districts, evaporation being so marked that the plant isseriously aooled and deprived of adequate water supply. Whenthese factors are made good, wind does little harm to crop growth.99Itis shown that cereal seeds can withstand dry heat to a tempera-ture of, 100° for some hours without serious loss of germinatingpower, whilst some of the disease spores affecting seeds were killed.1Studies have been made on somewhat similar lines of wilt-producing fungi, temperature having been found which will keepthem in check without unduly damaging the plant.2Of the numerous specialised papers, two may be mentioned.Composition of Crops.Few problems present greater difficulty than those associatedwith the composition of crops. Farmers grow crops in order tosell them, but neither they nor the purchasers know what is inthem.Little is known of the composition of crops, and, unfortu-nately, it is proving very difficult to arouse any interest in thisor the closely allied subject of quality in crops.The oat crop is one of the most important to the farmer, and ithas been studied in detail by Berry a t the West of Scotland Agri-cultural College.3 A mass of analytical data is presented whichis by far the most extensive hitherto available in this country.Various relationships were found between weight and compositionof the kernel; with the thin, husked, white grains, as the kernelincreased in weight the proportion of husk decreased, the oil andfibre diminished, whilst the carbohydrates, the yield of grain, andthe proportion of grain to total produce increased. It is animportant practical observation that the yield per acre is associateddirectly with the average size of individual grains, whilst theproduction of straw varies in the opposite direction.The composition of the grain was affected by variation in organicmatter content of the soil, for example, ploughed-up grassland andarable land, but season produced comparatively little effect, andartificial fertilisers still less.Locality, however, had a markedeff eot .Investigations on the wheat crop on somewhat similar lines havebeen made at the University of Manitoba.4 I n an importantpaper it is shown that the protein content of wheat is much affectedby climatic factors, by restriction of water supply, and by varietal*@ L. Hill, Proc. Roy. Soc., 1921, [B], 92, 28.1 D. Atanasoff and A. G. Johnson, J. Agric. Em., 1920, 19, 379.2 H. A. Edson and M. Shapovalov, ibid., 18, 511.3 R. A. Berry, J. Agric. Sci., 1920, 10, 359.H. E. Roberts, J . Agric. Res., 1920, 10, 121AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.195factors. I n breeding new varieties for general purposes, it issuggested that strains should be sought which vary greatly in theirprotein content, since a wide starch-protein ratio would probablymean greater climatic adaptability. For restricted areas, how-ever, wheats of maximum protein oontent should be sought. Thereduction of protein subsequent on irrigation can be largelycounterbalanced by introducing lucerne into the rotation.5Plant Constituents.Constant additions are being made to the long list of plant con-stituents, and little more than the briefest reference is possiblehere. Until the function of a substance is known, the mere factof its presence is not necessarily of much physiological interest.Cellulose, Lignin, e t c.-These substances constitute the largerportion of the material of the plant structure, and steady progressis being made with the knowledge of their constitution.6 Perhapsthe most important paper on this subject is a critical discussionof the constitution of cellulo~e.~ Lignin has also been the subjectof investigation; it has received the formula C,,H,,OI,, and issupposed to be built up from pentoses.8Plant Pigments.-Flauones are yellow pigments ; those obtain-able from the tulip9 and from Rhus10 have been studied.Anthocyanins are formed from flavones by reduction. The redpigment of the young leaves of the grape vine is regarded asidentical with enidin, the anthocyanidin derived from the pigmentof the purple grape. This is the first instance reoorded in whichthe red leaf pigment is an anthocyanidin.11Members of the beet-red group of anthocyanins have been foundin the skins of fuchsia and cacti berries, and in the petals of scarletcactus flowers.12Anthocyanins are further reducible to leuco-bases .The tinctorial properties of a number of the anthocyanins haveJ.S. Jones, C. S. Cohen, and H. P. Fishburn, J. Agric. Sci., 1920, 10, 290.P. Klason, Arkiv Kem. Min. Geol., 1917, 6, No. 15 ; A., i, 148.7 K. Hess and W. Wittelsbach, Zeitsch. EZektrochem., 1920, 26, 2 3 2 ; A.,8 P. Klason, Arkiv Kern. Min. Geol., 1917, 6, No. 15; A., i, 148.9 B. Harrow and W. J. Gies, Proc. SOC. Expt. Biol. Med., 1918, 16, 8 ; A.,10 C. E. Sando and H. H. Bartlett, Amer.J. Bot., 1915, 5, 112 ; A., i, 272.11 0. Rosenheim, Biochem. J., 1920, 14, 178 ; A., i , 467.F. Kryz, Oesterr. Chem. Zeit., 1920, 23, 5 5 ; A., i, 515.l3 A. E. Everest and A. J. Hall, J. Xoc. Dyers and Col., 1919, 35, 275 ; A . ,been studied.13i, 532.i, 70.i, 70.H 196 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Sugars and Other Carbohydrates.-An improved method fordetecting dextrose in plants has been described.14 Both gentianoseand sucrose have been detected in the roots of Gentiana cruciataand G. purpurea.16Primeverose has been isolated from Primula officinalis; it is abiose formed by combination of a molecule of dextrose and a mole-cule of xylose, and it has a free aldehyde group.16Inulin is the storage product in some plants, notably the arti-choke. It does not occur in the leaves, but is formed in the stemand the tuber, presumably from the dextrorotatory carbohydratessupplied to the leaves.17Odorous Constituents.-The odorous constituents of apples havebeen found to consist essentially of the amyl esters of formic, acetic,and hexoic acids, with a very small amount of the octoic ester,ansd, in addition, acetaldehyde, and probably some free acid.18Proteins.-Osborne has continued his work on plant proteins,and has turned to the difficult problem of the leaf proteins, spinachbeing selected for examination.At least 40 per cent. of the totalnitrogen of the leaves was found in the form of colloidal protein,which, however, may be in some form of combination with a sub-stance of pentosan nature.A nearly colourless protein was, how-ever, obtained.19Two globulins and an albumin have been extracted from theGeorgia velvet bean.20 Globulins have been extracted from thecoconut (Cocos nucif era) 21 and the jackbean (Canavalia ensi-formis),22 whilst phaseolin has been studied,23 and also the proteinsof polished rice.24Alkaloids.-Niootine is not present in the seed of tobacco; it is,indeed, harmful to germination, but it appears in the young plantimmediately the chlorophyll begins to function, and it originatesin the leaves. 1n case of injury, for example, cutting, the alkaloid]is produced in increased quantity in the adjoining tissues. It isl4 E. Bourquelot and M. Bridel, Compt. rend., 1920,170, 631 ; A., ii, 337.l5 M. Bridel, J . Pharm. Chim., 1920, [vii], 21, 306; A., i, 467.l6 A. Goris and C. Vischniac, Compt. rend., 1919, 169, 871, 975 ; A., i, 14.l7 H. Colin, Bull. Assoc. Ch7m. Sucr., 1919, 37, 121 ; A., i, 358.F. B. Power and V. K. Chesnut, J . Arner. Chem. Soc., 1920, 42, 1509;l9 T. B. Osborne and A. J. Wakeman, J . Biot. Chem., 1920, 42, 1 ; A.,zo C. 0. Johns and H. C. Waterman, ibid., 69 ; A., i, 515.21 G. 0. Johns, A. J. Finks, and C. E. F. Gersdorf, ibid., 1919, 37, 149;23 A. J. Finks and C. 0. Johns, ibid., 1920,41, 375 ; A., i, 401.24 J. Kurosawa, J . Tok3o Chem. Soc., 1919,40, 551 ; A., i, 414.A., i, 653.i, 516.A., i, 210, a2 J. B. Sumner, ibid., 137 ; A., i, 210AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 197supposed, therefore, that nicotine is elaborated by the plant fromcertain residues of the nitrogen katabolism, either to preventaccumulation of these residues or to utilise them with intensifi-cation of their harmfulness in defence of its organs.25Lyoorine, C,,H,,O,N, has been found in various plants of theorder Amaryllidacez.26Hydrogen Cyanide.-Considerable technical importance attachesto the occurrence of hydrogen cyanide in plants. This substanceusually occurs in glucosidal combination, as in bitter almonds,cherry laurel leaves, seeds of Phaseolus lunatus, etc. It may alsooccur, however, in non-glumsidal form, in the buds of the cherrylaurel and the young leaves of Sainbucus niger.27Enzymes.-It is not proposed to discuss here the generalproblem of enzyme activity, but reference must be made to onepaper. The peroxydasic function in plants, which appears to beshown by living cells only,28 and is usually attributed t o enzymes,now appears to be due to iron compounds, katabolic products ofmore complex compounds, such as naematoids, which, in virtue oftheir physical state, are able to aot between the oxidisablesubstances and the peroxides.29 E. J. RUSSELL.25 L. Bernadini, Atti R. Accad. Lincei, 1920, [v], 29, i, 62 ; +., i, 412.26 K. Gorter, Bull. Jard. bot. Buitenzorg, 1920, [iii], 1, 352; A., i, 467.27 L. Rosenthaler, Sciaweiz. Apoth. Zeit., 1919, 57, 571 ; A . , i, 271.J. G. McHargue, J . Amer. Chem. SOC.. 1920,42, 612; A., i, 406.29 G. Gola, Atti R. Accad. Lincei, 1919, [v], 28, ii, 146; A., i, 208

ISSN:0365-6217    

DOI:10.1039/AR9201700175

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

CR,YSTALLOGRAPHY AND MINERALOGY.THE striking renewal of activity in the subjects under review in thisReport is all the more gratifying because they were among the firstto suffer from the outbreak of war. The volume of work to be notedis, indeed, so considerable that space will not allow some investi-gations to be treated in accordance with their intrinsic merits. !Thisis especially the case perhaps in the province of crystal-structure.In the first place, there are to be noted two books of more thanordinary value. The one by Niggli1 not only contains a full andclear account of all the point-systems, but also brings the subjectup to date iq the light of X-ray methods and results. Sommerfeld’sbciok2 is more general, covering, in fact, recent developments in awide field of physical discovery and interpretation, to which thestudy of crystals has contributed so powerfully.Then there are twoimportant contributions to the related subjects of atomic distancesand volumes, and also many successful reconstructions of crystals,all of which will receive due notice. On the other hand, an ingeni-ous development of X-ray technique must be disposed of here some-what summarily. The method depends essentially on the study ofa sequence cf Laue photographs, the crystal being turned through aknown number of degrees, by the help of a special tvo-circle gonio-meter, between the various exposures. m e photographs are thenanalysed by the help of a new instrument termed a ‘(cyclometer,”and the direction of a structural plane of symmetry, if such bepresent, is thereby located.Fresh exposures on the goniometerlead to a determination of the ‘‘ X-ray class of symmetry,” that is,the real class to which has been added a centre of symmetry; and aset of crystal-elements can also be deduced. I n other words, theinvestigation oan be evidently carried t o the same stage as is custom-P. Niggli, “ Geometrische Krystallographie des Diskontinuums,” 1919,a book that arose from an analytical investigation of the cubic-point systemby the same author, Jakrb. Min. Beil-Bd., 1919, 43, 1.A. Sommerfeld, “ Atombau und Spektrallinien.”a R. Gross, Gentr. Min., 1920, 52.19CRYSTALLOGRAPHY AND MINERALOGY. 199ary by orthodox geometrical methods, but the crystal need have noplane faces. The method has already been applied to crystals oftungsten,4 and also, without an actual publication of details, to tri-dymite and hzmoglobin.What appears to be a final determination of the symmetry-class ofthe mineral benitoite may well be mentioned here, as illustratingthe meaning of the term X-ray class of symmetry.According toF. Rinne,s there are only three symmetry-classes which are worthyof a consideration : (1) trigonal equatorial, (2) ditrigonal equatorial,and (3) ditrigonal polar, each of which by addition of a centre ofsymmetry happens to lead t o a distinct class, namely, (1) hexagonalequatcrial, (2) dihexagonal equatorial, and (3) dihexagonal alter-nating. Laue photographs of homogeneous portions of a crystalunmistakably rule out the first and third alternatives, and benitoiteis accordingly the first representative of the ditrigonal equatorialclass.Theoretical discussions of the finer details of crystal structure arebecoming more frequent.The effect of various possible types ofelectronic arrangement on the general symmetry of the diamond,rock-salt, and sylvine has been worked out by H. Thirring.6 Withregard to the much-vexed question of the chemical aspect of crystalstructure, opinion would seem to have taken a welcome, if belated,turn in the German literature-perhaps on account of Wiilstatter’s 7expressed opinion that the disappearance of the molecule in a crystalcannot be reconciled with the immense body of well-established factsof organic chemistry.Two papers by A. Reis 8 are also suggestivein this connexion. An allusion may also be made here to the impor-tant work, which has been carried on during the last twenty-fiveyears, on the hehaviour of crystals to infra-red radiation-work thatis disseminated in various journals and worthy of a complete Reportin itself. In a sense, the work has more chemical interest thanX-ray work, for infra-red radiation would seem to be a molecular asopposed to an atomic probe. All carbonates, for example, exhibitan intense reflection for infra-red rays of a specific wave-length, nomatter whether they are in the state of fusion, solution, or crystal.Quite recently there have been numerous attempts to correlate theextreme wave-lengths (residual rays--(-( Reststrahlen ”) , selectivelyreflected by crystals, with the elastic and other constants.An im-portant paper by H. Rubens and H. von Wartenberg 0 is the key toR. Gross and N. Blassman, Jahrb. Min, Beil-Bd., 1919, 42, 728.Centr. Min., 1919, 193.Ph?ysikal. Zeitsch., 1920, 21, 281 ; A., ii, 477. ’ R. Willstatter, Zeitsch. angew. Chem., 1919, 32, 331.Zeitsch. Elektrochem., 1920, 26, 408, 412.Sitzungsber. Preuss. A k d . Wiss. Berlin, 1914, 189 ; A., 1914, ii, 236200 A."UAL REPORTS ON THE PROURESS OF CHEMISTRY.some of the earlier papers. Some supplementary references 10 tomore recent papers may be useful to those who are interested. Itmust be noted that the conclusions about fluorspar are vitiated byan arithmetical mistake. An early publication of the new compu-tations is promised.As the portion devoted to Mineralogy is supposed to cover aperiod of three gears, it will be realised that no space can beallotted to the results of chemical analysis and descriptions of newmineral species; further, that little attention can be devoted towhat may be termed the observational side of the science.Fortun-ately, these aspects are already well cared for in special journals.A recent list of new minerals, for example, has been given bySpencer,ll and a new venture on the part of the MineralogicalMagazine-the publication of abstracts-would seem t o be justifiedby results. Several important American investigations of mineralsystems are to be noted, which emphasise the desirability of thefoundation on this side of something of the nature of a Petrophysi-cal Institute; which, without being an exact copy of the Americanoriginal, could fruitfully co-operate with it in the advancement ofpure and applied science.Without some such centre there arealmost insuperable difficulties in the way of any serious Europeancontributions t o experimental mineralogy, for the problems thereinvolved require such special resources as are scarcely within thepower of a University laboratory to provide. One department ofsuch an Institute might well be devoted to the manifold chemicalproblems connected with crystals. The future of crystallo-chemicalanalysis, in particular, would seem to require something more thanthe spasmodic support of individuals.The simplification of themethod, and the reduction to a unified system of the numerouscompounds described within the last six years, not to speak of thelimitless compounds of the future, would require some form oforganised effort. Chemists could then be encouraged, not only tosend their new crystalline compounds to be investigated and regis-tered, but also to expect help, as a matter of course, in the identi-lo H. Rubens, Ber. Deut. physikal. Ges., 1915, 17, 315 ; Sitzungsber. Preuss.Akad. Wiss. Berlin, 1917, 43 ; H. P. Rollnagel, Physical Rev., 1918, 11, 135 ;M. Born, " Dynamik der Kristallgitter," 1915 ; Ber. Deut. physikal. Ges.,1919, 21, 533; M. Born and 0. Stern, Sitzungsber. Preuss. Akad. Wiss.BerZin, 1919, 48, 901 ; M. Born, ibid., 1918, 604 ; A., ii, 401 ; M.Born andA. Land6 Ber. Deut. physikal. Ges., 1918, 20. 210; A., 1919, ii, 188; A.LanZt, ibid., 1918, 20, 217 ; 1919, 21, 644 : K. Fajans, ibid., 1919, 21, 539,714; A.. ii, 21; M. Born, ibid., 1919, 21, 533; Ann. Physik, 1920, [iv], 61,87 ; A . , ii, 227 ; M. Born and E. Bormann, ibid., 1930, 62, 218 : W. Voigt,dbid., 1919, 60, 638.l1 I,. J. Spencer, Min. Mag., 1919, 18, 373CRYSTALLOGRAPHY AND MINERALOGY. 201fication of complex products of reaction, especially in those casesin which they are hampered by a paucity of material.Atomic Distances and Volumes.Two recent attempts to carry our knowledge of atomic volumesbeyond the stage represented by Lothar Meyer's well-known curvewould seem to indicate substantial progress towards a solution ofthe simpler problems connected with this most difficult subject.The first paper to be noted deals not so much with volumes aswith atomic distances in crystals.As a result of a critical survey ofthe numerous structures which have been successfully determinedby various X-ray workers, W. L. Bragg12 finds that the distancebetween contiguous atomic centres of any given pair of elements,A and B, is almost constant for all crystals. Now, if the atoms beregarded as spherical, this distance can be regarded as made up ofthe sum of the radii of the two atoms, and if the radius of atom Abe known then the radius of atom H can be obtained by subtrac-tion. In this way, by making use of the X-ray data referring tosuch crystalline elements as carbon, silicon, and various metals, theauthor is subsequently able to deduce preliminary values for theatomic radii of such elements as oxygen, nitrogen, sulphur, and thehalogens, which have so far only been investigated in the form ofcompounds.These preliminary estimates are then mutuallyadjusted by an elaborate series of cross-checks, the result being atable of mean radii or diameters, in agreement as a rule with indi-vidual observations within the limits k10 per cent. Further, it ispossible to deduce diameters for certain other elements from com-parisons of the molecular volumes of isomorphous substances. Theresults are given in the form of a curve (with atomic diametersplotted against atomic numbers), which is here reproduced as far asthe element strontium (see Fig.1). It is seen that the diameters,as thus deduced from the established structures of crystallineelements and compounds, are of the same periodic character as theso-called atomic volumes of the Lothar lleyer curve. (Paren-thetically, it may be here added that the ionic radii for the halogensand alkali metals have been deduced in another way by A. Land6,13who attributes a greater radius to a halogen ion than to an ion ofthe alkali metal immediately following it in the list of the elements.A similar view is held by K. Fajans.l* This want of agreementbetween Bragg and Land6 and Fajans cannot be discussed here, itsthe more important of the German papers are not available.)la Phil. Mag., 1920, [vi], 40, 169; A., ii, 537.l3 Zeitsch.Physik, 1920, 1, 191 ; A., ii, 540.l4 Ibid., 2, 309; Zeitsch. Elektrochern., 1920, 26, 502.H202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Bragg’s paper must be consulted for a discussion of the physicalsignificance assigned to these diameters. The immediate objectwould seem t o be strictly practical. “The way of regarding theatoms as spheres packed tightly together is useful in constructingmodels of crystalline structures . . . and, it is hoped, will help infuture investigations . . . by limiting the number of possiblearrangements.” An example of this practical usefulness will begiven below under casium dichloroiodide. The writes would alsomention that the application of the method to the cassiterite groupand to anatasel5 points t o the need of a revision of the modelswhich have hitherto been offered.The second investigation refers to the volumes of elementaryatoms. Setting out from the current view that the elements typi-fied by sodium, magnesium, aluminium, and silicon respectivelypossess 1, 2, 3, and 4 outer electrons, and a corresponding effectiveFiQ.1.number of positive charges on the nucleus, Sommerfeld 16 examinesthe attractive effects of these successive increases in nuclear chargeon the radius of the outer electronic ring, and he deduces that theatomic radii of the four elements specified should exhibit the ratios1:0*57:0.42:0-33. He also points out (as will be indicated pre-sently) that these values are in fair agreement with the valuesobtained by dividing atomic weight by specific gravity.Now W. L.Bragg has emphasis4 the fact that the structural details of acrystal must be taken into account; that the packing of sphericalatoms is closer in some elements than in others; in other words,that the old meaning of atomic volume is of the nature of a fiction.It is therefore interesting t o bring into the comparison the valuesof the true absolute volumes (for which the writer is responsible),l5 Ann. Reports, 1917, 14. 233. l6 A. Sommerfeld, op. cit., 105CRYSTALLOGRAPHY AND MINERALOGY. 203and also their ratios.lowing table.The various results are embodied in the fol-Table of Volume Constants.Na. Mg. Al. Si.Hull's abso1ute"distances (p) ......... 3-72 3-22 2.86 2-35 x cm.True absolute spherical volumes..26.9 17.5 12.2 6.79 x C.C.True atomic-volume ratios ............Sommerfeld's theoreticd ratios ......Sommerfeld's cited ratios ................1-00 : 0-65 : 0-45 : 0.251-00 : 0.57 : 0.42 ; 0.331-00 : 0.57 : 0.41 : 0.51It is seen that the true atomic-volume ratios are in general agree-ment with Sommerfeld's theoretical values, and do not exhibit thegreat discrepancy 0-51 with respect to silicon-an apparent but nota real anomaly, which is simply due to the relatively open packingof the silicon (or diamond) structure. The general agreement is nodoubt due to the relative simplicity of the problem of atomicvolumes in the particular case of chemically uncombined elements.*Recent Structural Models.In view of the novelty and high degree of importance attachedto the X-ray method, an attempt has always been made in theseReports to give complete lists of those models which appear to bewell established.This custom will be adhered to on the presentoccasion.Some Cubic and Hexagonal Elements and Compounds.-Thlereare some fifteen substances which can be disposed of in the form* A brief note on the more salient aspects of atomic volumes in compoqdsmay not be out of place. It might seem a t the outset that the conversi,onof W. L. Bragg's absolute " atomic diameters " into corresponding sphericalvolumes (whereby the fluctuations naturally become of the order +_ 30 percent.) might throw light on such a perplexing problem as the undoubtedvolume equality of ammonium and rubidium compounds-a problem towhich neither atomic weights nor atomic numbers bring any solution.Now the radius of the ammonium radicle can scarcely be greater than thesum of the radius of nitrogen and the diameter of hydrogen.As the latterdiameter is generally accepted by physicists to be 10-8 cm., the radius of theradicle comes out to be 1-65( x 10-8 cm.), which is much lower than 2.25,the radius of the rubidium atom. The corresponding spherical volumes are,of course, much further away from the expected ratio 1 : 1, being by calcula-tion in the proportion 1 . 2-5. The nearest interpretation of this discrepancyis that an initially spherical or (as some mathematical physicists prefer)cubical atom suffers a deformation on entering into chemical union ; but theobvious difficulties which stand in the way of any precise definition of thenew shapes, added to the possibility that atoms may change their volumeon combination owing to a rearrangement or an actual transfer of electrons,would seem to demand the discovery of new methods of experimentationbefore real progress can be made.H* 204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of a table. With the exception of thorium and nickel (determinedby H.Bohlin)," all the values given below are due t o Hu11,18 whosays, apropos cobalt : " A finely powdered sample produced by rapidelectrolysis showed a mixture of cubic and hexagonal close-packingin nearly equal ratio. After annealing in hydrogen at 600°, thissample showed only the cubic form.Another sample, composed offilings from pure cast metal, showed slight traces of hexagonal pack-ing, due presumably to straining. It is possible that the otherclose-packed metals will behave in a similar manner, but this ques-tion has not been studied." According t o Hull, ductility in ametal is a result of a face-centred cubic arrangement.Table of some Cubic and Hexagonal Structures.Distance be-Arrangement Grating distance tween atomicof atoms. of cube planes. centres.Cobalt (dimorphous). .. Face-centred cube(cubic close-packed).Thorium .................. Do. 2.56 3.62Nickel ..................... Do. 1.765 2-50Rhodium ............... Do. 1.9 1 2.70Platinum ............... Do. 2.01 2-86Chromium ...............Centred cube 1.455 2-52Molybdenum ............ Do. 1.576 2.7 3Magnesium ............ Hexagonal close- - 3.222.84 Zinc ..................... Do.3-15 Cadmium ............... Do.Cobalt (dimorphous). .. D O . - 2.53Lithium fluoride* ...... Simple cube 2.01 2.01Sodium fluoride* . . , , . . Do. 2.31 2-3 1Potassium fluoride* ... Do. 2.69 2-69Magnesium oxide* ... Do. 2-11 2-111.785 x lo-* cm. 2.52 x 10-8 cm.packed. --* In these four cases the arrangement of like atoms is, of course, given bythe face-centred cube.,4n.timony.lg-The nature of this structure is perhaps best graspedas follows. Suppose the familiar rock-salt cell, of Fig. 2, be set upwith a solid diagonal vertical and then extended along it until theoriginal cubic 9O0-angle has attained the value 9 2 O 53'.The edgeof the cell must now be taken t o be 3.10 x 10-8 cm.; the correspond-ing length of the vertical diagonal is 5.64. Now let 'the centresof the chlorine atoms be shifted through a vertical distance of 0.42(exaggerated in Fig. 3), and finally suppose all the atoms to be re-placed by antimony; the result is the antimony structure, which isthe first example among eleaents of a '' hexahedral " structure, thatl7 Ann. Physik, 1920, [hl, 61, 421 ; A., ii, 214.ID R. W. James and N. Tunstall, Phil. Mag., 1920, [vi], 40, 233 ; A.. ii, 648.A. W. Hull, Proc. Arner. Inst. Electrical Engineers. 1919, 38, 227CRYSTALLOQRAPHY AND MINERALOGY. 205is, one in which each atom is closely environed by six other atoms.Ir, all previous cases of elementary substances the environment hasalways been tetrahedral, octahedral, or dodecahedral.Zincite,20 Zn0.-The crystal structure of this well-known dihexa-gonal polar mineral provides one of the few cases in which a verbaldescription is better than a diagram.Isomorphous with green-ockite, CdS, and wurtzite, ZnS, it exhibits an interesting structuralcontrast t o the commoner form of zinc sulphide-zinc blende. I nboth minerals the zinc atoms are essentially arranged in accordancewith the principle of close-packing, the difference being that in zincblende the “ cubic ’’ style of close packing is affected, in zincite the(( hexagonal ” style. I n both structures the zinc (or cadmium)atoms are environed tetrahedrally by the sulphur (or oxygen) atoms.FIG.2. FIG. 3.The absolute vertical distance in zincite between successive layersof similar atoms is 2.60, whilst the horizontal interval betweenadjacent atomic centres is 3’22. It is of interest to recall the factthat E. S. Fedorov 21 showed that two different structures are recon-cilable with the preliminary observations recorded in W. H. andW. L. Braggs’ well-known book, one of them demanding atomicpolarity, the other being the structure finally adopted by W. L.Bragg.The Calcite Group.-An X-ray study that has some bearing onthe question of the existence of groups of atoms in crystals we oweto R. W. G. WyckoffyB2 who has subjected calcite, rhodochrosite,chalybite. and magnesite (as also sodium nitrate23) to an investiga-2o W.L. Bragg, Phil. Mag., 1920, [vi], 39, 647; A , , ii, 433.a1 Bull. Acad. Sci. Petroqrad, 1916, 10, 377.aa Amer. J . Sci., 1920, [iv], 50, 317.23’Idem., PhyRicaZ Rev., 1920, [ii], 16, 149 ; A., ii, 756206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion by the Nishikawa method-essentially an ingenious combina-tion of the Laue and de Broglie methods. The nature of some ofthese compounds has been previously elucidated by W. H. andW. L. Bragg, who explained their results in terms of a face-oentredlattice, but the structures are, perhaps, best visualised as beingthe sodium ohloride structure, which has been deformed along athreefold axis until the cleavage cube has acquired the angles ofthe cleavage rhombohedron, the sodium and chlorine atoms beingthen regarded as substituted by calcium atoms and carbonate groupsrespectively. An inspection of Fig.4 (which is drawn true to scale)will show t>hat triads of oxygen atoms are relatively close to indi-vidual carbon centres. The main result of the new investigation ist:, show that these triads are a t a constant distance of 1.22 Ang-strom units from their corresponding carbon atoms, although allother atomic distances vary considerably in passing from one car-FIG. 4. FIG. 5.nbonate to another-the distances between adjacent carbon andmetallic atoms, for example, being 3.04 and 2.83 A.U. in calciumand manganese carbonates respectively. This can be interpreted asevidence of the persistence in the crystal structure of the C0,-groups, the internal details of which are, so to speak, no concernof the externally placed metallic ion.Caesium DichEoroiodide, CsC1,I.-The elucidation of this rhombo-hedral substance has been successfully accomplished by the sameauthor24 by means of the Nishikawa method.The lattice can beregarded as derived from the rock-salt type of structure, by a com-pression along a three-fold axis, until the cubic 90° angle hasacquired the rhombohedra1 SOo 12’ value. The absolute dimensionof this vertical length is 6-06 x 10-8 cm.; czesium and iodine atomsare placed alternately a t the corners. A chlorine atom is locatedR. W. G. Wyckoff, J . Amer. Chsm. SOC., 1920, 42, 1100; A., ii, 489CRYSTALLOGRAPHY AND MINERALOGY. 207on the principal axis of this cell at a distance equal to 0.62 timesthe celldiagonal, from either the msium or the iodine atom.* Theorigin of this ambiguity lies in a circumstance peculiar to thechemical composition ; the reflecting powers of the horizontal strataof msium and iodine atoms are approximately equal (on account ofthe close atomic weights or numbers of the elements concerned), andthe strata are accordingly indistinguishable from each other bymeans of X-rays.. , . The writer therefore thought it would beinteresting t o examine the two questions : (1) whether the structureas determined by Wyckoff is reconcilable with W. L. Bragg”s valuesof atomic diameters, and (2) whether the application of theseatomic diameters serves to remove the ambiguity concerning theposition of the chlorine atoms.The answers to both these ques-tions would seem t o be emphatic affirmatives. Figs. 6-7 representFIU. 6. Fqa. 7 .uertical elevations on the plane (il0). In Fig. 6 W. L. Bragg’smean ualues, Cs =4*74 ; I = 2.80 ; C1= 2- 10, have been adopted;although there is a slight interpenetration of the iodine and chlorinespheres of influence, the spacial accommodation for the variousspheres can be regarded as satisfactory. This interpenetration canbe avoided and the general fit improved, without tampering withWyckofYs data, if some such amended values as Cs=5*36, 1=2.70,and C1=1*90 be adopted (compare Fig. 7). In both figures thechlorine-centres have been taken as lying nearer to iodine than tomsium; if the chlorine-centres lay nearer to czsium, they wouldfall inside the e s i u m atoms.* Since emh of the corner-atoms of the cell is really common to eightcells in an idnitely extended structure, and since the chlorine atom bslongswholly to the cell illustrated, it follows that the total cell-composition ia${Cs,T,)Cl, which is equivalent to CsICl,208 A ~ A L REPORTS ON THE PROGRESS OF CHEMISTRY.Physical Crystallography.This important branch of physics is poorer by the loss of ProfessorW. Voigt, of Gottingen, so celebrated for his experimentalresearches io 'elasticity and the many other abstruse properties ofcrystals requiring a highly mathematical treatment.EZectroZytic Conduction.-The many experimental difficultieswhich have long stood in the way of an exact study of electrolyticconduction in crystals have been recently overcome by Tubandt,26who has thereby opened up a new field of investigation (the abstractmust be consulted for an account of the general method of experi-mentation).Since the specific conductivities of the compoundsexamined are very low a t ordinary temperatures, the experimentswere carried out in a stream of an indifferent gas at as high a tem-perature as practicable. This immediately led to the interestingobservation that the specific conductivity of the cubic form of silveriodide (stable above 144'6O) is 3000 times as great as in the caseof the hexagonal modification (both measured near the transitiontemperature), and if the measurement be effected close t o themelting point the value is actually much higher for the solid thanfor the fused substance.Crystals of silver chloride, bromide, andiodide were found to behave as unidirectional electrolytes, permit-ting freely the migration of silver ions (in amounts which rigor-ously obey Faraday's law), but preventing all movement of halogenions in the reverse direction. Lead chloride, however, behaves inexactly the opposite way, the negative chlorine ions migratingfreely. The author points out that these trustworthy results ofcareful experiment are difficult to reconcile with a view that thecrystal ions of binary compounds are held in equilibrium by elec-trostatic forces. The investigation of silver sulphide, of whichthere are two forms, /3 (179O)a, revealed a new point of interest.The high temperature a-modification behaves just like the halogensalts of silver, but with the &form there is simultaneously an elec-tronic conduction in the opposite direction, so that the crystalexhibits both electrolytic and metallic conduction. The author isdisposed to refer this to the presence in the B-form of two kindsof molecules.Ultramicroscopic inclusions in Crystals.-It will be rememberedthat inorga& ultra-microscopic '' colloidal " particles have beendefinitely proved to be crystalline by the use of the Debye-Scherrer-Hull method of X-ray exploration.26 The investigation of minuteC.Tubandt, Mitt. Naturjor8ch. Ges. HaZEe, 1917, 4, 21 ; C. Tubandt andS. Eggert, Zeitsch. anorg. Chern., 1920, 110, 196 ; A., ii, 279; C.Tubandt,Zeitsch. Elektrochern., 1920, 26, 360. es Ann. Rep&, 1919, 16, 197CRYSTAXLOQRAPHY AND MINERALOGY. 209particles in crystals by the help of the ultramicroscope is now pro-ceeding. The beginnings of this work apparently lie in a suite ofpapers 27 on the nature of nietal-fogs in crystals. It has been foundthat absolutely pure crystals of lead chloride, silver chloride, andbromide (that is, crystals of the ordinary substances which havebeen recently treated with halogen to transform any trace of freemetal into haloid) are ultramicroscopically transparent. I f thismaterial is melted and treated with a trace of free metal or of areducing agent like potassium cyanide, a metallic fog is producedin the re-solidified material.Novel results are obtained in the caseof lead chloride, for owing to the strong double refraction of thecrystal each speck of light, arising from an ultramicroscopio par-ticle, is doubled and plane-polarised. Thallium ohloride andbromide could not be obtained clear, since they cannot be treatedwith halogen without the formation of higher haloids.The method has been more recently applied28 to a study of theorigin of opalescence in mixed crystals of sodium and potassiumchloride, occasionally erupted by Vesuvius. The previous investi-gation of the binary system, NaCl-KCl by Nacken 29 was, of course,invaluable. m e opalescence is due to a separation of the twocomponents consequent on the temperature falling below the pointof complete miscibility for a given mixture.It was instructive toobserve the process in laboratory products of various compositions,as it gradually unfolded itself under the ultramicroscope. Thecrystal becomes doubly refracting, due to strains ; then the sepa-rated particles reveal their existence, and finally strains and thedouble refraction disappear. The author proposes to attack thesystem orthoclase-albite, in which a primary homogeneous mixedcrystal (“ anorthoclase ”) will no doubt eventually yield a micro- orcryptoperthitic structure.Specific Beats of Minerals.-A monumental research on thespecific heats of the various modifications of silica and of the moreimportant silicates has been published by White,so who within thelast few years has greatly improved the general technique of hightemperature measurement.The constants directly determined were‘‘ interval-specific heats,” that is, average specific heats over suchranges of temperature as 0-looo, 0-300°, 0-500°, and so on.From these values the specific heat a t any desired temperature wasdeduced by two new methods, which gave perfectly consistent27 R. Lnrenz and W. Eitel, Zeitsch. anorg. Chem., 1915, 91, 46, 57, 61;A., 1915, ii, 260.2 8 W. Eitel, Centv. Mia., 1919, 173.R. Nacken, S~tzungsber. Preuss. AEad. Wi.~s. Berlin, 1918, 192: A.,1919, ii, 281.$0 W. P. White, Amer. J . Sci., 1919, [iv], 47, 1 ; A., 1919, ii, 133210 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.results, and this when multiplied by the factor M / n (where M isthe molecular weight, and n the number of atoms in the molecule),finally yields the mean atomic heat.At the ordinary tempera-ture the value of the lastrmentioned constant is of the order 3-3 forsilica and 3.75 for silicates; it increases with rise of temperature, a tfirst quite rapidly and then more gradually as it approaches alimiting value in the neighbourhood of 6-0. The results will nodoubt have great significance in the future study of certain geologi-cal proeesses, but it may be noted that tkey have already animportant bearing on various questions of great theoretical. interest.The atomic heat a t constant volume, for example, can be computedfrom the observed atomic heat. a t constant pressure by the help ofa well-known thermodynamic formula, involving compressibility,thermal expansion, and density, but the computed value for cristo-balite (according to Fenner 31 the stable modification of silica above1470O) cannot be reconciled with generally accepted theoreticalideas, which must accordingly rest on a faulty basis.Moreover,the results obtained from a study of the various modifications ofsilica oan be used as a test of the reasonableness of Smits’ theoryof dynamic sllotropy,s2 and as a result of his painstaking work ofprecision the conclusion is drawn by White that it is possible toover-estimate the value of that theory.Optics.-Attention must be called t o a paper33 on the generaloptical properties of amyrolin, C,,H,,O,. This monoclinic substanceexhibits an abnormally high birefringence (apparently onlyexceeded by calomel), and is also very noteworthy on account of astrong dispersion of the conical refraction.Two papers by A.Ehringhaus 34 on the dispersion of the birefringence of manysubstances are also worthy of a careful perusal.Corn para t iue Chemical Cry st allogra ph y .The progressive nature of the effects produced by a mutual sub-stitution of the elements potassium, rubidium, and caesium, as wellas the close similarity of rubidium and ammonium compounds,which has been largely emphasised by Tutton’s investigations dur-ing the last thirty years, is now so well known that iC is onlynecessary to place on record a recent paper by this indefatigabhworker35 dealing with the compounds typified by the formula31 C .N. Fenner, Trans. SOC. Qlass Technology, 1919, 3, 116.32 Ann. Reports, 1914, 11, 268.33 H. Rose, Jahrb. Min., 1918, 1 ; A., 1918, i, 266.34 Ibid., Be&-Bd., 1916, 41, 342 : 1920, 43, 557.35 A. E. H. Tutton, PYOC. Roy. SOC., 1920, [A], 98, 67 : A., ii, 690ORYSTALLOGRAPHY AND MMEIEALOGIY. 211R,Cu(SeO,),,GH,O. There are also two papers to be noted refer-ring to series of organic compounds. m e first, by A. Ries,% dealswith an extensive series of mono-, di-, tri- and tetra-alkyl deriv-atives of ammonium picrate, some of which have been previouslyexamined by Jerusalem. The main results of this work are two innumber: first, the prevalence of polymorphism in organic com-pounds (many of the substances appearing in three or four forms),and secondly, the regularity with which one of the modifications ofevery tetra-substituted picrnte is either strictly hexagonal orpseudo-hexagonal.The theoretical interpretation of this regu-larity would have been easy if the substances concerned had beentri-substituted. The second paper 37 deals with the series of com-pounds, typified by the general formula R,N*HgI,, in which Rrepresents various alkyl, aryl, or alphyl groups. One result is toprove that the raceniic compound, dl-Ph(CH,Ph)MeEtNHgI,, isisomorphous with the corresponding diethyl oompound, whichnecessarily consists of identical and symmetrical molecules. Perhapsthe most noteworthy features of the paper, however, are the omis-sion of all computed angles, as being unnecessary to any futurepurpose, and also the description of the methods devised in recentyears, which serve to reduce the routine work of crystal descriptionto about one-third of that formerly required.Methods of Investigating Opaque Substances.Although opaque minerals are not relatively very numerous, theyrepresent a highly important class of compounds, if only becauseof their supreme economic value.In the pasf the identification ofopaque compounds has had to depend on such simple physical testsas density, cleavage, hardness, and streak (supported by themethods of chemical analysis), since the ordinary optical methodsare only applicable to transparent substances; but in recent yearsmore and more attention has been paid to those special microscopicmethods introduced by Sorby, which have been developed more andmore in connexion with metallography.This technique has beenapplied t o minerals (notably in America). The new method hasbeen recently expounded in at least two books,38~~ and a generalaccount, together with a most valuable bibliography, has also been36 Zeitsch. Kryst. Min., 1920, 55, 454 : A., i, 715.3 7 T. U. Barker and (Miss) M. W. Porter, T., 1920, 117, 1303.3 8 J. Murdoch, ‘‘ Microscopical Determination of the Opaque Minerals, ”3 3 W. M. Davy and C. M. Farnham, “Microscopic Examination of Ore1916.Minerals,” 1920212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.given by a German worker.40 The method has been variouslynamed '' Mineralography," " Opakography," and " Minera-graphy "-terms which are perhaps less pronounceable than " Chal-cography " (suggested by Brauns).The method consists essentially of the examination, under amicroscope fitted for side-illumination, of the upper surface of aspecimen which has been ground, polished, and possibly etched withvarious reagents.Both ordinary and plane polarised light areemployed. In the latter case any opaque mineral that does notbelong to the cubic system may reflect two plane or ellipticallypolarised rays, one of which is somewhat retarded (not, in general,to the same extent as in the case of transparent substances). Theprinciples underlying the various optical effects have been recentlytreated very thoroughly by Wright:' who has also done much toperfect the finer technique.42 The method has obviovsly a greatfuture, not least on the purely scientific side, for it promises tolead t o a revision of many opaque mineral species.It should alsoprove useful in the examination of dyes and lakes.Thermal Studies of Mineral Systems.Thermal studies of mineral systems are becoming so numerousthat they cannot all be described with a fullness proportionate t otheir deserts. I n making a selection, the writer is compeIled torestrict himself to some relatively simple investigations, and, infer-entially, to omit any consideration of the complex ternary system,43Ca0-Mg0-SO,, as also of Niggli's work 44 on certain mixed fusionsinvolving the oxides of sodium, potassium, calcium, aluminium,carbon, silicon, and titanium.It is believed that the relativelysimple cases will give a general idea of the significance of thepresenbday Lype of work, which is presumably the main object ofthis Report.Binary Systems involving Barytes, Getestine, and Anhydrite.-In continuation of his previous work,45 in which it was proved thatbarytea, celestine, and anhydrite pass into other modifications(probably monoclinic) a t high temperatures, Grahmann 46 hasinvestigatz? the miscibility relations of the substances over a vastH. Schneidwhtihn, Jahrb. Min. Bed.-Bd., 1920, 43, 400.41 F. E. Wright, Proc. Amer. Phil. SOC., 1919, 58, 401.42 Idem, Mining and Metallurpt, 1920. No. 158.Is J. B. Ferguson and H. E. Merwin, Amer. J . Sci., 1919, [iv], 4$, 81, 165;44 P.Nigqli, Z0;tsch. csnorg. Chem., 1916, 98, 241 ; A . , 1917, ii, 211.4.5 Ann. Reports, 1913, 10, 256.4 G W. Grahmann, Jahrb. Min., 1920, i, 1.A . , 1919, ii, 401, 459CRYSTALLOGRAPHY AND MINERALOGY. 213range of temperatures. The method adopted was that of coolingcurves, supplemented by density determinations and by a study ofthe optical properties in thin sections. It is found that each pairof the a(high temperature)-modifications yields an uninterruptedseries of mixed crystals. This is also true for the ~ ( I o w tempera-ture)-modifications of barium and strontium sulphates-in otherwords, for barytes and celestine. On the other hand, the misci-bility of the &modifications of calcium and strontium sulphates(anhydrite and celestine) is limited even a t the high temperatureof 1000c, and becomes more restricted a t the ordinary temperature.Anhydrite can take up 42 mol.per cent. of strontium sulphate, andcelestine up to 12 per cent. of calcium sulphate-the mixturesbeing isodimorphous in Retgers’ sense. Anhydrite and barytespresent a similar behaviour, but the miscibility is much morerestricted, each being able to take up about 6 per cent. only ofthe other. The research is, of course, of considerable mineralogicalinterest, for it reveals miscibility possibilities far in excess of thoseactually observed in nature, as determined by mineral analyses.Binary System A’Icermanite-Gehlenite.4~--The investigation ofmixtures of these two compounds may be regarded as an excellentexample of the experimental method of studying a perplexingmineral problem.Two distinct species-gehlenite,3CaO,Al2O3,2SiO2,and melilite, Na,O,l 1 (Ca,Mg)0,2 (A1,Fe),03,9Si02-are usuallyrecognisecl as belonging to the tetragonal “ melilite group.” Witbthese must be reckoned the closely related iikermanite, an impor-tant constituent of furnace slags, which, according to Vogt, is essen-tially a calcium silicate, 4Ca0,3Si02. Now a well-defined com-pound, 2Ca0,Mg0,2Si02, was found by Ferguson and Merwin toplay an important r61e in the ternary system, Ca0-Mg0-SiO,, andthey concluded it to be Akermanite in its purest form; moreover,since a compound, 2Ca0,Al,03,Si0,, deemed to be pure gehlenite,had been previously prepared by Rankin and Wright, the investi-gation of the equilibrium relationships of gehlenite and iikermanitesuggested itself as a method of attacking the difficult problem ofthe melilite group.It is found that the two isomorphous compon-ents form an uninterrupted series of mixed crystals exhibiting aminimum melting point (Roozeboom’s type 111). As gehlenite andAkermanite are respectively negative and positive optically, oneof the mixtures (55 per cent. of kkermanite) is isotropic. (As amatter of fact, this inversion of optical character was observed byVogt in the case of certain furnace slags, which he regarded as47 J. B. Ferguson and A. F. Buddington, Amer. J. 8 c i . , 1920, [iv], 50,131 ; A., ii, 621214 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.mixtures of gehlenite and hkermanite.) Another interesting itemis that akermanite glass has a higher density and refractive indexthan the crystalline modification.The authors hope to continuetheir work, so auspiciously begun, and there can be little doubt,that the correct interpretation of the melilite group will not be longdelayed.Ternary Systent,*8 Mg0-A120,-Si0, .-The investigation of thissystem was beset with much difficulty owing to th8 high tempera-tures involved, which were frequently beyond the limits of theplatinum furnace. The various binary compounds have been eluci-dated in previous researches and noted in these Reports. T'he onlyterhary compoutld is apparently a simplified cordierite,2Mg0,2A120,, 5 SiO,,a phase which decomposes a t a temperature lower than its meltingpoint, but which can crystallise out of a complex mixture a t some-what lower temperatures. The compound is best prepared byholding a glass of like composition a t temperatures lying between900° and 1400O; an unstable form begins to appear a t 900°, whichgoes over at a somewhat higher temperature to the stable form.The equilibrium relationships of this cordierite are somewhat com-plicatetl by the fact that it forms solid solutions wit.h spinel,MgA1,0,, and sillimanite, Al,SiO,.Natural cordierite containswater, and part of the magnesia is replaced by ferrous oxide, butthe general similarity in optical properties is sufficiently close toestablish its identity with the synthetic, iron-free cordierite.The Dehydration Process in Crystals (" Eflorescence ").The results of a comprehensive investigation of this process havebeen recently published by Gaudefroy.49 Although not generallysusceptible to ocular proof under the microscope, loss of water isalmost certainly accompanied by a temporary local liquefaction.Byway of a general suppopt to this conclusion, Gaudefroy sta€es thatalmost any finely powdered hydrate can be transformed into acoherent cake by simply allowing it to remain in a desiccator for afew hours. This behaviour he attributes to a temporary solutionof the solid in the water which it is about to lose by evaporation.In at least one case a periodic liquefaction and solidification isdirectly observable under the microscope. Under certain conditionsa crystal of the heptahydrated zinc sulphate becomes covered withmonoclinic crystals of the hexahydrated salt, which extend their4 8 G.A. Rankin and H. E. Merwin, Amer. J . SC~., 1918, [iv], 4-5, 301 ; A.,1918, ii, 199.4 9 C. Gaudefroy, Bull. SOC. Jranc. Min., 1919, 42, 284CRYSTALLOGRAPHY AND MINERALOGY. 215boundaries in a rhythmic manner. A t various stages a tiny crystalof the hexahydrate is surrounded by a zone of liquefaction, intowhich it grows as water is eliminated. The loss of one mo'iecide ofwater of crystallisation is accompanied by a contraction equal toabout one-tenth of the original molecular volume; and the surfaceof the new crystal consists of a concentric system of furrows andridges as a result of this periodic shrinkage.Another general point of interest is that the inception of dehy-dration and consequently the local fo?mation of a dehydrationfigure can be readily brought about by inoculation with a frag-ment either of the actual product of dehydration or of a substanceisomorphous with it. T'hus if an orthorhombic crystal of mag-nesium chromate, MgCr04,7H20, be simply touched by a crystal ofthe anorthic copper sulphate, CUSO,,~H,O, dehydration of thechromate to the pentahydrate begins immediately, and proceeds atsuch a rate as to be visible to the naked eye.Many hydrated substances lose water of crystallisation in morethan one well-defined stage.To each stage there corresponds acharacteristic dehydration figure. Thus, ferrous sulphste,FeS0,,7H20, either loses three m3leculss of water or one; in theformer case the figures are elliptical, whilst in the latter case theboundaries are rectilinear, being, in fact, either triangles ortrapezia.With many substances two or more kinds of transforma-tion take place simultaneously, so that it becomes impossible bymeans of a chemical ahalysis to correlate each type of dehydrationfigure with the specific amount of water lost There are, however,other ways of deducing the composition of the different products.Thus the hept'ahydrated cobalt sulphate, unlike its isomorphferrous sulphate, does not give the elliptical type of dehydrationfigure, but only the rectilinear type, and as the product can beproved by chemical analysis to be the hexahydrate, the same mustbe reasonably true of the corresponding type of figure given byferrous sulphate.A oonfirmatory test is to drop small fragmentsof the dehydrated salt into a saturated solution of another salt; ifthe fragments grow isomorphously, their composition is therebysatisfactorily determined. This test is particularly trustworthy inthe case of tlhe vitriols, which have been so thoroughly investigatedby previous workers from almost every conceivable point of view.Following is a brief summary of the various types of dehydrationfigure revealed by Gaudefroy's researches.Rectilinear Figures Determined by the Crystals under Dehydra-tion.-Figures of this class are quite numerous, being, in fact, givenin 54 per cent. of the substances examined. The dehydrationtakes place most favourably along certain selected planes of th216 ANNUAL REPORTS ON THE PROGRESS OF CHEMlSTRY.structural lattice, with the result that the dehydration figures onany given face are bounded by traces on that face of other impor-tant structural planes.By a study of the forms of the dehydrationfigure on the best developed faces of a crystal the “dehydration-polyhedron ” can be determined, from which the dehydration figurefor any other face can be deduced in the usual way. I n the case ofthe monoclinic heptahydrated’ sulphates of iron and cobalt, thedehydration polyhedron is bounded by the forms {OOl}, (110}, and{ 101j. The material within the boundaries of a given dehydrationfigure is a t first limpid, but soon becomes opaque; during thelimpid stage i t can be proved optically to consist of an irregulararrangement of minute crystals.Rectilinear Figures Determined by the Product of Dehydration.-Each of these figures, in their simplest form, represents a singlecrystal of the new hydrate. The figures on any given face haveaccordingly no precise orientation. A good example is the hexa-hydrated decomposition product of ordinary zinc sulphate, whichhas already been mentioned as growing rhythmically.Figures Exhibiting a Diuision into FOUT Sectors.-These areespecially common in gypsum, the anorthic and orthorhombicvitriols, and the ferrocyanides. Opposite sectors are optically simi-lar. The diagonals of the sectors are generally more distinct thanthe external boundaries, and have a definite orientation on eachcrystal face. The fine structure of the sectors is sometimes verycomplicated, but as a rule each sector is made up of a parallelbunch of fibres.EUipticaZ Pigures.-These figures are characterised by an extra-ordinarily fine texture of component particles arranged with everypossible orientation. The figures are generally very deep-seated,and the internal surfaces are also curved. Wherever several kindsof dehydration figure are given by the same substance, the ellipticalfigures are characteristic of that chemical change which involves thegreatest loss of water, and the excessively minute size of the com-ponent particles is attributed to the powerful disruptive effects ofthe correspondingly great contraction of molecular volume. It isicteresting to note that the ratios of the ellipsoidal axes may differwidely in isomorphous substances. In zinc vitriol, for example, theratios are 1.1 : 1 : 1.4, whilst in the corresponding magnesium saltthe ellipsoid practically becomes a sphere, and the figures on allthe faces are substantially circles and not ellipses. In a monocliniccrystal one of the three ellipsoidal axes is always coincident withthe symmetry axis, and in a uniaxial crystal the ellipsoid is one ofrotation.T. V. BARKER

ISSN:0365-6217    

DOI:10.1039/AR9201700198

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

RADIOACTIVITY .*Nuclear Constitution of Atoms.THE nuclear theory of the atom is based on the form of the trajec-tory of the a-particle in passing through the atom, which in turnis deduced from the deviation suffered by the a-particle in itspassage.' The fact that the overwhelming majority of thea-particles pursue practically rectilinear trajectories, whilst afew of them are deviated more or less abruptly, led to thewell-known conwption of the atom as a system of sparsely dis-tributed single electrons occupying the atomic volume, equal innumber 60 the atomic number of the atom, with a concentratedcountervailing positive charge, equal in magnitude to the corn-bined charge of the electrons, a t the centre of the atom, and con-stituting a nucleus of dimensions excessively small relatively tothe atomic volume.The inferenoe that this nucleus contains allbut some 0.05 to 0.02 per cent. of the mass and weight of the atomfollows from the known mass of the contained negative electrons,and is in general accord with the electrical theory of mass.According to this, the mass of an electric charge is proportionalto the square of the charge and inversely proportional to itsdiameter. To account for its mass on this view, the diameter ofthe nucleus of the uranium atom would be 4 x l O - l 5 cm., or 1150thof the diameter of the single negative eleatran, if it consisted ofpure positive electricity. That the nucleus is not a pure positivecharge, but contains negative electrons, the net charge being posi-tive and equal to the atomic number, is shown by the emission of@-rays from the radio-elements and by the mode of formation ofisotopes in radioactive changes. Hence the view is not free frominconsistencies.Impact of a-Particles on Heavy A toms.-Great improvementshave been made in the comparison of the experimental results ofscattering with the mathematical theory.The magnitude of the* This Report covers the years 191 9 and 1920.Ann. Reports, 1913, 10, 272 ; compare also R. Seeliger, Jnhrb. Radioaktiv.It'ektronik;, 1919, 16, 19 ; A., ii, 145.21218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.nuolear charge for platinum, silver, and copper has been evaluatedaccurately by a determination of the ratio of a-particles scatteredover a solid angle between 2 2 O and 36-5O.This ratio is propor-tional to the square of the atomic number and a quantity depend-ing on the velocity and known physical and instrumental constants.The minuteness of the ratio makes a direct determination, bycomparing the number of a-particles scattered with those in theoriginal beam, difficult. The difficulty was ingeniously overcome,however, by introducing a notched rotating disk into the path ofthe a-particles, when oounting the direct beam, and so reducingthem in a known ratio a t will to a number comparable with thenumber scattered. I n this case one obtains intermittent gusts ofscintillations with any desired interval between, conditions whichare very favourable t o counting, and actually enable the numberper second capable of being counted accurately to be five timesas great as without the device. This is apart from the completecontrol over this number by varying the relative size of the notch.The experimental values for the three metals named, 77.4, 46.3,29.3, are, in eaoh case, within the known probable error of theaccepted values of the atomic numbers, 78, 47, and 29.This,incidentally, is an important confirmation of the correctness ofthe absolute magnitude of the atomic numbers, and shows that thePeriodic Table contains no unsuspected vacant places.With the same arrangements, i t was possible to verify accuratelythe inverse-square law of force over the region in which scatteringof the a-partiole occurs for the platinum atom. The number ofparticles scattered, other conditions being constant, depends onthe initial velocity of the a-particle raised to the power 4/(1 - p ) ,when the force around the nucleus deviating the partiole variesas l / r g , r being the distance.The experimental value of p foundwas between 1-97 and 2-03, a variation from the inverse-square lawwithin the counting error of 4 per cent. The actual least distanceof approach to the nucleus was between 7 and 14(x10-12 cm.)for high and low velocity a-particles respectively. From otherexperiments in this field and in that bf the wave-lengths of theE-series of X-ray spectra, it follows that the inverse-square lawholds over a range between 3 and 100( x 10-12 cm.), and that therecan be no electrons in this region in the case of a heavy atom likeplatinum.These are fundamental oonclusions.2Impact of a-Particles on Light A toms.-Turning now to impactsof a-particles with the nuclei of light atoms, where the nucleusstruck is violently repelled,3 and itself constitutes a new type ofJ. Chadwick, Phil. Mag., 1920, [vi], 40, 734.3 Ann. Reports, 1914, 11, 274; 1916, 13, 261RADIOACTrVITY . 219radiant particle, such as the H-particle resulting from the passageof a-rays through hydrogen, most striking results have beenachieved. Here the a-particle approaches within 0-25( x 10-12 cm.)of the hydrogen nucleus, and the results point to rapid changesand possibly to variations of the direction of the field of formwithin the distance 0-35. The inverse-square law no longer holds.Only one in lo9 of the hydrogen atoms penetrated by the a-particleis repelled with a velocity sufficient to enable it to be detectedbeyond the range of the a-rays, or one H-particle is producedby a hundred thousand a-particles passing through 1 cm.ofhydrogen gas a t N.T.P. This number, though minute, is fromten to thirty times that to be expected if the inverse-square lawheld. The absorption of these H-particles over their range, whichis four times that oT the a-particle producing them, is reminiscentof the absorption of a-particles themselves, and is totally differentfrom what is theoretically to be expeoted. With H-particlesgenerated by long-range a-particles, over a range equivalent to22 cm. of air, there is practically no diminution of the number ofH-particles, whilst between this and the end of the range, 28 cm.,there occurs a gradually increasing diminution.With H-particlesgenerated by short-range a-particles, the theoretical curve is morenearly approached. The H-particles in the first case appear to beprojected in the same direotion as that in which the a-particle istravelling, or within a few degrees of it, all a t the same velocity.It is clear that to this case, where a very intimate approach ofthe helium and hydrogen nuclei occurs, special considerationsThe identity of these H-particles with hydrogen was proved bya determination of the deviation suffered in electromagnetic andelectrostatic fields. The value of elm found, 104, is in perfectaccord with that of the hydrogen ion, 9570 (E.M.U.).I t svelooity, namely, 1.6 times that of the a-particle generating it, isin perfect agreement with the maximum value calculated for ahead-on ” collision. The charge is positive in sign, and nonegatively charged particles were observed .5With regard to light gases other than hydrogen, helium givesno particles differing in range from the generating a-particle.From this it is inferred that singly charged atoms of helium, theestimated range of which would be four times that of the a-particle,are not formed. But oxygen, nitrogen, air, and carbon dioxide allgave scintillations of similar brightness over a range of 2 cm. ofL. R. Zoeb, ibid., 38, 533; A., ii, 145.aPPb*4(Sir) E. Rutherford, Phil.Mag., 1919, [vi], 37. 537: A., 1919, ii, 256(Sir) E. Rutherford, ibid., 562 ; -4., 1919, ii, 258220 AKNWAL REPORTS ON THE PROGRESS OF CHEMISTRY.air beyon’d that of the range of the generating a-particles. Thenumber was of the same order as those obtained in hydrogen gas.The range, 9 cm. of air, was only one-third as great, and thebrightness of the scintillations, a t a distance equivalent to 7.5 cm.of air, was equal to that of an a-particle a t 1 cm. from the endof its range, instead of a t 0.5 cm., as for the H-particle. Theoriginal presumption,6 that these short-range particles were dueto atoms of oxygen and nitrogen carrying unit charge, has nowbeen shown to be a t fault.7 It has been found possible to deter-mine their nature by special arrangements for the examination oftheir deflexion in a magnetic field, allowing the use of wide slits.Instead of the particles from oxygen being less deflected than thegenerating a-particles, as should be the case if they were singlycharged atoms of oxygen, they were more deflected, which excludesthe possibility that they oan be oxygen atoms, either singly ordoubly charged.A mass intermediate between 1 and 4 and adouble charge were indicated. The deviation suffered wasestimated to be 5 per cent. less than that suffered by H-particlesin a direct comparison, and the conclusion was drawn that theyconsist of doubly charged positive particles of mass about 3 witha velocity 1.2 times that of the generating a-particle. There wasno noticeable difference between oxygen and nitrogen, so far asthese short-range particles are conaerned.Both appear to yielda new particle of mass 3, differing from the ‘(H3” of positive-raymethods of gas analysis in that it carries two units instead of oneof positive electricity, and therefore is presumably an isotope ofhelium.Nitrogen, however, differed sharply from oxygen in giving, inaddition to these new particles, a very much smaller number (aboutone-twelfth) of H-particles. The range of these is slightly greaterthan of those obtained from hydrogen, but their identity wasproved by direct comparison of the electromagnetic deviation in theapparatus above referred to.* It is estimated that, to produce1 cubic millimetre of hydrogen by this means, the total a-radiationof 2 kilograms of radium acting for a year would be required.So far as can be seen, artificial disintegrations of atoms bycollision with the a-particle appear t o be endothermic.Theparticle of mass 3 appears to escape with rather more than theenergy of the a-particle striking the nucleus of the oxygen ornitrogen atom. Even neglecting the kinetic energy of the residueof the nucleus and of the a-particle after the collision, the dis-(Sir) E. Rutherford, Phil. Mag., 1919, [vi], 37, 571 ; A., 1919, ii, 259.7 Ibid., Bakerian Lecture, Proc. Roy. SOC., 1920, [A], 97, 374 ; A., ii, 541.* Ibid., Zoc. cit., and Phil. Mag., 1919, [vi], 37, 581; A . , 1919, ii, 260RADIOACTIVITY. 221integration, as in the case of the radio-elements themselves, mustbe accompanied by the liberation of energy.On the view thatthe actual energy required to bring about the disintegration issmall, and that the energy of the a-particle is mainly expended’against the strong repulsive field, in getting near enough to thenuoleus to affect it, electrons or /3-rays, which would move up tothe nucleus in an attracting field, may be able to bring aboutsimilar changes. This raises anew the whole question, so fre-quently discussed in these Reports,g as to the origin of the helium,found by some and not by other investigators, after passage of theelectric discharge through gases in vacuum tubes and in old X-raybulbs and the like. The latest experimental contribution gavenegative results, in so far as the discharge through carefullypurified hydrogen is concerned.In no case was helium or neondetected .lo Naturally, these highly significant results have pro-duced a flood of speculation as to the mnstitution of the atomicnucleus, which does not yet call for consideration here.Is0 t opes.Our knowledge of the heterogeneity of common elements hasbeen notably advanced, during the period under review, beyondthat recorded in the Reports four and seven years ago,ll by theperfection of the positive-ray method of gas analysis and its appli-cation to the detection of heterogeneity, if it exists, in somenineteen non-radioactive elements.12 The methods depend on thesame general principles as those which sufficed to detect thepresence of meta-neon, of atomio mass 22, in atmospheric neon in1913, but the electromagnetic and electrostatic deviating fields arerearranged in such a way as to secure an effect precisely analogousto focussing in optics.The trajectories of the positive ions in aslightly divergent beam are brought to a focus in a plane contain-ing the photographic plate. All those for which the value of themass divided by the charge is the same are brought to the samepoint in the plane, those with greater and less values, respectively,being on either side. The oomplex pencil is resolved into a “massspectrum” in every respect analogous to a light spectrum pro-duced by a prism or grating. The terms “first-order and second-s Ann. Reports, 1914, 11, 45, 289.lo A. Piutti and E. Cardoso, Gazzettu, 1920, 50, i, 5 ; A., ii, 312.l1 Ann.Reports, 1916, 13, 245 ; 1913, 10, 265.l2 F. W. Aston, Nature, 1919,104, 334, 393 ; 1920,105, 8, 547 ; 106, 468 ;Phil. Mag., 1919, [vi], 39, 449, 611; 4, 628; A., ii, 277, 344, 718222 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.order mass-spectrum” are used to denote spectra produced by ionssingly and doubly charged respectively. The existence of ions withmore than one unit of charge introduces a complication, but fortu-nately these are experimental peculiarities which enable the twoorders usually to be distinguished without uncertainty. The relativemass of the ion causing any line in the spectrum can so be evaluatedto an accuracy of one part in a thousand, and the atomic massdetermined to a degree of accuracy comparable with that attainedin the best determinations of the atomic weight by chemical means.Incidentally, the complete agreement between the two in manycases affords much the most important evidence of the constancybetween mass and weight for different elements.This question hasbeen much canvassed of recent years.Of the nineteen elements so far examined, ten prove to be homo-geneous and nine t o be heterogeneous and composed of more thanone isotope with different atomic masses. The following table,taken from the author’s last communication to Nature, gives theresults.TABLE OF ELEMENTSAtomicElement. number.Hydrogen- ............Helium ...............Boron ..................Carbon ...............Nitrogen ............Fluorine ...............Neon ..................Silicon ...............Phosphorus .........Sulphur ...............Chlorine ...............Argon ..................Arsenic ...............Bromine ...............Iodine ..................Xenon ...............Oxygen ...............Krypton ...............12567891014151617183335365354Mercury ...............80Atomicweight.1-0083.9910.9012.0014.0116-0019-0020.2028.3031.0432.0635.4639.8874.9679-9282.92126.92130.32200.60AND ISOTOPES.Minimum Masses of isotopes,number ofisotopes. intensity .1 1.0081 42 11, 101 121 141 161 192 28, 29, (30)1 31in order of their2 20, 22, (21)1 322 35, 37, (39)2 40, 361 752 79, 8161 1275 (7)84, 86, 82, 83, 80, 78129, 132, 131, 234, 136,(128, 130 ?)(6) (197-200), 202, 204(Numbers in brackets are provisional only.!Apart from a possible uncertainty, already alluded to, as tothe order of spectrum to whioh any line belongs, the photographspublished reveal the great power and certainty of the new method.Unfortunately, only non-metallic elements have so far beenincluded.The difficulties in the way of examining metallicelements by this means have not yet been overcomeRADIOACTIVlTY. 223In every case, except hydrogen, the atomic mass of each homo-geneous component proves to be an exact integer, in terms of thatof oxygen as 16, within the error of measurement already stated.For hydrogen, however, the chemical value, 1.008, is exactly con-firmed and its homogeneity proved.Hydrogen, of course, is anexception to every generalisation concerning the chemical elements,and its simple structure, consisting probably of a single positivecharge as nucleus and a single electron as satellite, is a sufficientreason for its uniqueness. I f the hydrogen nucleus is theelementary positive constituent of the nuclei of other atoms, anumber of electrons, equal to the difference between the atomicweight and atomic number, must be present also. Thus, if thenucleus of uranium is made up of 238 hydrogen nuclei, there mustbe in the nucleus 238-92=146 electrons. The close packing ofthese positive and negative constituents may account for the differ-ence of mass, 1.9 units, between the mass of the constituents andthat of the resulting atom, that is, essentially to the difference inthe atomic weights on the basis H = 1 and O= 16.l3The integral value of the atomic weights then points to anatomic constitution of secondary units, such as helium nuclei,packed sufficiently openly not to influence their mutual masses, thewhole of the packing effect being due to the close packing withinthese secondary units.Isotopes of Lead.Atomic Weight of Leud of Radioactive Origin.-Fuller detailsof the atomic weight determination of the lead from Norwegianthorite, which gave 207.9, the highest yet found, have been pub-lished, together with those found for lead from three Ceylonthorianites, partioulars of which follow : 14Per cent.Th. Per cent. U. Per cent. Pb. At. wt.I. ......... 68.9 11.8 2.3 207-2111. ......... 62.7 20-2 3.1 206.90111. ......... 57.0 26.8 3.5 206.83Lead separated from samarskite, containing 12.2 per cent. ofU30, and 1.03 per cent. of Tho,, gave the value 206.30.15 Leadfrom a Japanese source, of possible, though doubtful, radioactiveorigin, gave the value 207.13, which does not differ appreciablyfrom that of common lead.16l3 Compare Ann. Reports, 1916, 13, 253.l4 Compare Ann. Reporter, 1918, 15, 201 ; 0. Hhigschmid, Zeitsch.l5 A. L. Davis, J . Physicul Chem., 1918, 22, 631 ; A., 1919, ii, 107.l6 T. W. Richards and J. Sameshima, J . Amer. Chem. SOC., 1920, M, 928 ;Elektrochem., 1919, 25, 91 ; A., 1919, ii, 285.A., ii, 434224 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Melting Point .-Two determinations show that, within the errorof measurement, the melting point of lead of radioactive origin isidentical with that of common lead.I n 0 ~ , 1 7 the lead, comparedwith common lead, had the atomic weight 206-57. A constantin-manganin couple was used, and the melting points were found tobe identical to 0 - 5 O , the experimental error. I n the other,l8thermocouples of copper-nickel were employed, the single couplebeing capable of reading hundredths, and the multiple couplethousandths, of a degree.The lead compared in this case was from an Australian radio-active mineral of atomic weight 206.6. Neither specimen wasspectroscopically pure, the common lead being the less pure, butprobably the impurities did not exceed 0-005 per cent.Theyshowed slight diff erenoes of behaviour. The super-cooling wasgreater for the purer sample, and its freezing-point-time curvewas more horizontal. The radioactive lead had the higher meltingpoint by 0*05O, but part, if not all, of this difference is to beascribed to its greater purity. The thermo-electric power, electricconductivity, and change of the latter with temperature andpressure, were for each sample the same. These negative resultsthus have now decided between opposing theoretical views beforediscussed . l gSpectrum.-The minute difference, 0.0043 A., in the wavelengthof the line 4058 A., already reported, has been confirmed.%Ordinary lead, lead from Joaohimsthal pitchblende of undeter-mined atomic weight, and lead from Ceylon thorite of atomic weight207.77, were compared.The method consisted in photographingthe respective interference fringes, produced by a Fabry and Perotttalon, the source of light being an arc between an alloy ofcadmium with the lead and a button of tungsten in a vacuum.Important sources of error present in the first series of experi-ments,21 which gave a negative result, were eliminated by reducingall observations t o a selected cadmium fringe as standard, whichregisters any variation due to a change of temperature or to thewandering of the souroe of light. These causes affect the standardfringe equally with the fringe under examination, and are soeliminated.The wave-length for the pitchblende lead was foundto be 0*0050 A.*0*0007 A. greater than that for ordinary lead,17 M. Lembert, Zeitsch. Ebektrochem., 1920, 26, 59 ; A., ii, 216.18 T. W. Richards and N. F. Hall, J . Amer. Chem. SOC., 1920, 42, 1550;l9 Ann. Reports, 1916, 13, 252.2o Compare Ann. Reports, 1918, 15, 2 0 4 ; T. R. Merton, Proc. Roy. Soc.,-4., ii, 622.1920, [A], 96, 388 ; A., ii, 140. a1 Ann. Reports, 1916, 13, 248RADIOACTIVITY. 225which, in tum, was 0.0022 A.+0-0008 A . greater than that forthorite lead. Also, a difference was found for the wave-length ofthe line 5350 A. of thallium when ordinary thallium and thethallium contained in pitchblende residues were compared, theformer being the greater by 0.0053 A.kO.001 A.I n this case,owing to the thallium not having been separated from the residues,the result cannot be entirely depended on, for the displacementof lines, by the presence of impurities, in the arc spectrum, thoughrare, is not entirely unknown. But it indicates a presumptionthat the thallium in pitchblende is of radioactive origin anddifferent in atomic weight from ordinary thallium.I n an interesting discussion of the spectra of isotopes,zz it ispointed out that the differencm in the case of lead, although onlyof the order of a millionth of the wave-length, are one hundredtimes greater than are to be expected from the Bohr theory, ascorrected to take into account the displacement of the centre ofmass o f the vibrating system with a change of the mass of thenucleus. They are enormously greater than can be ascribed to anypurely gravitational effect of the mass of the nucleus on theelectron.The result indicates the existence of a force, due to themass of the nucleus, on the eleotronic system of the atom nothitherto known. In the original experiments, in which a 25 cm.grating was used and the spectrum photographed in the sixthorder, the line was shifted, not broadened, to a position correspond-ing with the mean atomic weight of the lead, although a broaden-ing, if not an actual resolution, into two or more lines correspond-ing with the separate isotopes present, in these circumstances,although not in the subsequent ttalon experiments, is apparentlyto be expected. This minute difference of wave-length of the linesin the spectrum is the only difference in the physico-chemicalproperties of isotopes, apart from atomio mass, so far substantiated.Separation and Properties of Isotopes.It cannot yet be considered proved beyond doubt that any actualanalytical separation of the components of a mixture of isotopeshas been effected.Systematic fractionation of atmospheric neonby the use of cold charcoal failed to effect any separation. Evenfractional diffusion through pipe-clay has not, so far, given con-sistently positive results.’3 The theoretical question of the possi-22 W. D. Harkins and L. Aronberg, J . Arner. Chern. Soc., 1920, 42, 1328;pa F. A. Lindemann and F. W. Aston, Phil. Mag., 1919, [vi], 37, 5 2 3 ;REP.---voL. xvrr. 1A., ii, 841.A . , 1919, ii, 209226 ANNUAL REPORTS ON THE PROGRESS OB CHEMISTRY.bility of separation by various means has been much dis0ussed.aMethods, such as fractional diffusion, centrifugal separation, andthermal diffusion, which depend on diff ereiices of niolecular mass,if not those, such as vaporisation and chemical fractionation, oughttheoretically to be effective. The thermal diffusion method,depending on the maintenance of two intercommunicating vesselsa t widely different temperatures, which produces a oondition ofequilibrium, in which excess of the heavier constituent is presentin the colder vessel, and centrifuging! both appear promising fromthe theoretical point of view.Preliminary announcements of the partial separation of theisotopes of chlorine, mercury, and iodine ( !) have been made.I nthe first case,25 indications of a separation of hydrogen chloride byfractional diffusion into a heavier and lighter fraction have beenannounced, but no definite experimental data are given. In themse of mercury,2G evaporation a t low pressure is stated to give acondensate less in density than the residual mercury. Each frac-tion was redistilled before the density was taken, and the differencein the pyknometer determinations amounted to 5 parts in 100,000,the error of measurement being less than one part in a million.Iodine, the most recent of the elements to be submitted to positiveray analysis, and found, unlike chlorine and bromine, to be homo-geneous, has, from speculative reasoning, been ascribed five isotopes.Fractional diffusion gave products with atomic weight varying from128.22 upward, the mean being 2.04 per cent.above the acceptedvalue .27Very interesting new results have been obtained along the linesof the use of radioactive isotopes of common metals to indicatewhat is occurring t o the latter in chemical operations. Thus i thas been shown that a free exchange of the metallic atom amongthe competing acid radicles occurs for ionised, but not for non-ionised, compounds, The general method was to mix solutions oftwo different compounds of lead in equimolecular proportions, theone compound only being " activated " by presence of thorium-B,which is isotopic with lead, and to determine the activity of thelead in the less soluble compound crystallising out.When activelead nitrate and inactive lead chloride are dissolved in molecularzp F. A. Lindemann, Phil. Mag., 1919, [vi?, 38, 173; S. Chapman, ibid.,182 ; A., 1919, ii, 390.W. D. Harking, Nature, 1920, 105, 230 ; Science, 1920, 51, 289.E. Kohlweiler, Zeitsch. physikal. Chem., 1920, %, 513; 95, 95; A.,26 J. N. Brijnsted and G. von Hevesy, Nature, 1920, 106, 144.ii, 610, 615RADIOACTIVITY. 227proportion in boiling pyridine, the lead1 in the lead chloride crystal-lising out is half as active as the lead in the original lead nitrate,but when an active lead salt is so mixed with an organic compoundof lead, such as lead tetraphenyl or diphenyl nitrate, in suitablesolvents, no interchange of lead occurs, and the active lead saltretains its original activity.This const'itutes something like adirect proof of the ionic dissociation theory and of the currentviews as to the difference between the nature of chemical union inelectrolytes and non-electrolytes. When the acetates of quadri-valent activated lead and of bivalent inactive lead are mixed inglacial acetic acid, the activity of the first compound, after crystal-lising out from the mixture, is reduced to one-half. This indicates,since the two lead ions differ only by two eleotrons, a free inter-change of electrons between them and a dynamic equilibriumbetween ions and electrons, and between free electrons and theelectrodes in electrolysis.28Isotopes have been used to determine the velocity of diffusionof molecules among themselves. The rate of diffusion is dependenton the molecular diameter, and not on the mass, so that a radio-active isotope diffusing among the inactive moleoules of the sametype of element affords the means for investigating experimentallythis otherwise insoluble problem.The case has been tried withmolten lead. A t the bottom of a narrow, vertical tube was placeda layer of lead rendered active by the presence of thorium-B, andabove it a layer three times the height of common lead. Thewhole was kept a t 340° for several days. After cooling, thecylinder was cut up into four equal lengths, each melted andhammered into foil, and the concentration of thorium-B in eachdetermined by a-ray measurements.Values for the diffusioncoefficient between 1.77 and 2.54 per sq. cm. per day, with a meanof 2.22 in seventeen experiments, were obtained. This oorrespondswith a diameter of the lead molecule between 0.78 and1.16( x 10-8 cm.), according to the formulae used to connect thetwo quantities. The value found, when reduced to a temperatureof 1 8 O and for a fluid of the viscosity of water, becomes 2.13.Since the value for lead ions diffusing in aqueous solutions is 0.68,this indicates that the molecular diameter in the case of metalliclead is only a third of that in the case of the ion, and shows thatthe latter is probably hydrated.29a* G. von Hevesy and L. Zechmeister, Ber., 1920,53, [B], 410 ; A , , ii, 278 ;a0 J. Gr6h and G.von Hevesy, Awn. Physik, 1920, [iv], 63, 85; d.,Zeitsch. Elektrochem., 1920, 26, 161 ; A., ii, 345.ii, 739.1 228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Researches analogous to those reported have led t o the detectionand isolation of volatile hydrides of lead and tin.30A notable rival has been developed t o the view described in thelast Report31 of an atom in which the electrons are supposed t orevolve in orbits around the nucleus, with special assumptions asregards the radiation of energy in quanta rather than continuously.I n this atom, the electrons surrounding the nucleus are supposedto occupy, or oscillate about, certain fixed positions in the struc-ture. This fixed electron type of atom has been found to possessmany advantages in chemistry and physics, notably in acmuntingfor the Periodic Law, the various categories of chemical compounds,ionised and un-ionised, and the arrangement of the atoms in thecrystal space-lattice as determined by X-ray methods.It may besaid to draw its underlying postulates from facts in these fieldsrather than from any purely mathematical or fundamental reason-ing.32 The chief idea is that, in the outermost shell of electronssurrounding the nucleus, the electrons tend to form an octet andto owupy the corners of a cube. I n the outermost shell all eightcorners are occupied in those atomic structures corresponding withthe zero family of chemically inert gases. The chemical activityof other elements is due to some of the corners being not occupiedby electrons, whereby two or more atoms tend chemically to“combine.” The oombination may be of two kinds.Either theatoms with only a few of the corners occupied by electrons, thatis, of those elements in the first families of the Periodic Table, losetheir electrons altogether, forming positive ions, such as Na’, Mg”,Al”’, to the atoms which have all but a few of the corners occupied,that is, of those elements in the last families of the Periodic Table,with the formation of the negative ions, such as Cl’, S”, or moreoften to groups of these atoms. This way of regarding ionisedcompounds was, of course, arrived a t long before this theory wasproposed, but it emphasises the completely separated existence ofthe two ions forming the moleoule, even in the solid state, whichis supported by the character of the space lattices of the crystals3 0 Arzn.Reports, 1918, 15, 225 ; 1916, 13, 266 ; F. Paneth and K. Furth,Ber., 1919, 52, [B], 2020; F. Paneth and 0. Norring, ibid., 1920, 53, [B],1693 ; A., ii, 41, 758.3l Arm. Reports, 1918, 15, 206.32 G. N. Lewis, J. Amer. Chem. SOC., 1916, 38, 762; A., 1916, ii, 310;I. Langmuir, Proc. Nut. Acad. Sci., 1919, 5, 252; J . Amer. Chem. ~ o c . , 1919,41, 868, 1543; 1920, 42, 274; A., 1919, ii, 328, 506; 1920, ii, 243; Science,1920, 51, 605 ; A., ii, 656 ; W. Kossel, Zeitsch. Physik, 1920, 1, 395 ; A.,ii, 681RADIOACTIVITY. 229of salts. The forces a t work are the opposed charges on the ionswhich act statistically, n sodium ions requiring the simultaneouspresence of n chlorine ions, rather than each sodium atom beingattached to one chlorine atom, as in the formula Na-C1.I n the second kind of combination, namely, that correspondingwith definite atomic linkings, such as are regarded to exist betweenthe atoms of the molecule in organic compounds and in non-electrolytes generally, the theory is mdre original.Different atomsso rigidly linked together are regarded as sharing electroiis inpairs. Two electrons held in common by two atoms constitute theordinary single bond. Fourelectrons in common correspond with a double bond. The cubesare attached face to faoe. A corner to corner attachment of twocubes, which the single bond most closely suggests, is not con-sidered to occur a t all.The sharing of a pair of electrons by twoatoms is regarded as the single unit of valency.I n addition to this type of definite linkage, two others arepostulated. The hydrogen nucleus is capable of sharing a pair ofelectrons, its own and one derived from another atom, either anatom of itself, as in the hydrogen molecule, or ail atom containingail uncompleted octet. Thus in water the oxygen nucleus is atthe clentre of a cube of electroiis, two pairs of which, a t two oppositepairs of contiguous corners, being shared with two externalhydrogen nuclei. Pairs so held are supposed to be drawn closertogether, distorting the cube. I n this way, the tetrahedralcharacter of the carbon atom is accounted for. The uncombinedatom of carbon, if i t existed free, which, of course, never occurs,would have four of the eight corners of the cube oocupied withelectrons. If symmetrically distributed, these would occupy thecorners of a regular tetrahedron. When it shares these in pairswith electrons of other radicles or atoms in compounds, the draw-ing together of each pair shared preserves the tetrahedral characterof the arrangement in the combined atom.The facts of stereo-chemistry require free rotation to be possible about a single bond,and not about a double bond, whereas, unless further assumptionsare made, such as that the pair are drawn together to one pointor supposed to rotate round one another, free rotation would notbe a possibility for a single linkage on this theory.The existenceof triple bonds again, whiclh is possible on a tetrahedral, isimpossible on a citbic atom. if only partly deformed to a tetra-hedron.The second type of combination postulated is rather surprisingin that a pair of nuclei are supposed to be contained in a singleciihe. or octet, i n such combinations as t,he nitrogen molecule,The cubes are attached edge t o edge230 ANNUAL REPORTS ON THE PROQRESS OF OHEMISTRY.carbon monoxide, hydrocyanic acid, and nitric oxide. If this iscorrect, suah compounds would represent, as it were, structureshalf-way between those typical of atoms and molecules respectively.Although something might be said for such a structure representingthe properties of nitrogen, one would scarcely have expected it tobe capable of representing also such an extremely active gas asnitric oxide.Into this theory of valency, which so far seems to be confinedmainly to the lighter elements in the earlier part of the PeriodicTable, it is unneoessary further to enter here.Of more topicalsignificance is the way in which the atomic numbers of the PeriodicLaw are accounted for. The atom is regarded as made up of con-centric shells of electrons of relative diameter 1, 2, 3, 4, and relativearea 1, 4, 9, 16. Each electron is regarded as occupying the samesuperficial area, to whatever shell i t belongs. The inert gases arethe elements formwhich the outer shell contains its full oomplementof electrons. Helium, of atomic number 2, has two electrons atthe poles of the first shell.The line joining them and passingthrough the nucleus is regarded as the polar axis of the atom.The plane passing through the equator divides the shell into twohemispheres. There are no electrons in the equatorial plane of anyatom. I n the outer shells, concentric with the first, they are dis-tributed according to the symmetlry of a tetragonal crystal. Foursecondary planes of symmetry, at 45O with each other, pass throughthe polar axis. The second completed shell, being four times thearea of the first, contains eight eleotrons, occupying the eightcorners of a cube. This is the neon atom. The atomic numberis 10, and i t contains eight electrons in the second shell-four ineach hemisphere above and below the equatorial plane-and twoin the first, or helium, shell.Every shell, other than the inner-most, after getting filled up with electrons once, is filled up twice,and the next inert gas is argon, atomic number 18, containingsixteen electrons in its second shell and two electrons in its first.I n the next, krypton, of atomic number 36, the third shell con-tains eighteen eleotrons, two distributed a t the poles and the othersixteen symmetrically with regard to the polar axis and the sixteenunderlying electrons of the second shell. By filling the third shellagain we get xenon, of atomic number 54. The fourth shell con-tains thirty-two electrons, and the next inert gas must have anatomic number 86. This is the correct atomic number for theemanations of ,the radioactive elements.Unfortunately, thePeriodic Table comes to an end before this ingenious theory canbe further tested. That, however, the table should prooeed touranium, which possesses complete chemical analogy to tungsteRADIOACTIVITY. 23 1and molybdenum, instead of t o a second lot of rare earth elements,after radium and thorium, raises the doubt whether i t just doesnot come to an end in time for the theory. Undoubtedly, how-ever, it is an achievement, even by such arbitrary assumptions, tohave accounted for the actual sequence of elements in the tablea t all.The theory has found general support in the explanation of thearrangements of atoms in crystals as elucidated by X-raymethods.33 It is possible to assign t o each atom in the space-latticea definite approximate diameter, and to regard the crystal as builtof spheres of these diameters closely packed.When the atomicvolumes corresponding with these diameters are plotted againstatomic weights, a curve, in every respect analogous t o LotharRfeyer’s atomic volume curve, is obtained, but applicable to thecompounds of the elements. Then i t is found that two electro-negative elements are situated close together, and are assignedsmall diameters when, ’according to the above theory, they shareelectrons ; but the electropositive elements, which exist as separatedions and do not share electrons with their neighbours, are situateda t a distance from them, and appear to have large diameters.From crystal data, the diameter of the electronic shells correspond-ing with neon, argon, krypton, and xenon are put at 1.30, 2.05,2-35, and 2-70 Angstrom units respectively.The theory, beingdefinite and easily visualised, if arbitrary, will doubtless justifyitself in drawing attention to the many different types of chemicalinteraction, which hitherto have been too liable to be confusedtogether and forced into a mould to fit just the one type of inter-action which the ordinary valency-bond theory suffices to explain.It is not yet possible t o bridge the gap between this idea and thatof the rotating electron atom, which has grown up largely 1roiiithe study of the wave-lengths of the characteristic X-rays theni-selves. Undoubtedly each type has its advantages, but forohemistry the fixed electron type seems easily to hold the field.I n the light of these advances, an experiment showing that thea-radiation from different faces of a large crystal of uraniurunitrate was, within the error of experiment, of the same intensity.seems to show that the a-particles are shot out from trhe nucleusduring disintegration, without, relation to the orientation of t h eatomic axis, for it may be regarded as at least highly probablethat in the crystal space-lattice the atoms have their axes orientatedin a regular manner 34** W.L. Braggy Royd Institution Evening Lect,ure, May 28th, 1920 ;a4 T. R . Merton, Phil. Maq., 1919. [vil, 28. 4 6 3 : A . . 1919, ii, 453Phil. Mag., 1920, [vi], 40, 169; A . , ii, 637232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Ifiyh- f re y I I e 12 c?/ S p e c t ra of t h e Ele m e n t s .35Work in this field proceeds apace, though without breaking muchfresh ground.Precision measurements, to a degree of acouracyone-hundredfold greater than previously, have been carried out forthe lines in the K series of a number of elements from chlorine tocopper, and the results compared with the various mathematicalforniulae .proposed. The spectrum of tungsten, for which the X,L , and iif series can all be studied, has also been examined, and aspectrograph constructed t o bridge the gap between these two seriesof precision meas~rements.3~ The Jf series has been further in-vestigated, and extended from uranium as far as dysprosium.37New measurements of the absorption bands of thulium,neoytterbium, and luteciuin in the Ii series have been made.38An examination of the.L absorptioii spectrum of a pure radiumchloride solution gave two lines, 0.802 and 0.670 A . , in agreementwith the atomic iiuinber 88 assigned by the Periodio Table.39 Bythe use of a reinforcing screen of calcium tungstate, the fl, line ofthe A- spectrum of tungsten (0.1844 A.) has been shown t o be adoublet separated by about 0.0007 A.40 In ail examination of theX-ray absorption spectrum of phosphorus, differences of wave-lengthwere observed for different forms. The wave-length 5.767 A. wasfound for the black phosphorus of Bridgeman, and 5.750 A. forphosphoric acid and its ammonium salt, whilst red phosphorusshows a double limit, corresponding with each of the two wave-lengths given. This is believed to be the first case noticed of thechemical state .of an element affecting its X-ray spe~trum.~'Arrangements have been described for the examination of thespace-lattices of powdered materials, by which it has been shownthat thorium and nickel in powder form have face-centred cubicallattices, and niagnesium a lattice ooniposed of two interpenetratingsimple hexagonal lattices.42X-Rays have also been used to determine the size and structureof the particles of organic and inorganic colloids.Gold and silver35 Compare Ann. Reports, 1916, 13, 257.36 M. Siegbahn, PhiE. Mag., 1919, [vi], 37, 601 ; 38, 639 (and with A. U.TAde), 647 ; A., 1919, ii, 261, 498, 489 ; E. Hjalmar, Zaitsrh.Physik, 1920,1, 439 ; A . , ii, 665.37 W. Stenstrom, Atzti.. Physik, 1818, [iv], 57, 347 ; A., 1919, ii, 90.38 M. de Broglie, Compt. rand., 1920, 170, 725 ; A . , ii, 277.3 y Ihid., 1019, 168, 854; 169, 134; A . , 1919, ii, 207, 358.41 J. Bergengren, +bit?., 1920, 171, 624 ; A . , ii, 654.42 H. Bohlin, L41?j/. T'l/?/sik, 1920, [iv'), 61, 421 ; A . , ii, 214 ; compareIbitl., 1920, 170, 1053 ; A., ii, 344.A. W. Hull, J . d v t r r . C'ittm. 8 o c . , 1919, 41, 1 1 6 8 ; .4.. 1919, i i . 470RADIOACTIVITY. 233in the colloid fomi possess the same bpace-lattices as in largecrystals, even when the particles are too small to be visible underthe ultramicroscope. I n old silicio acid and stannic acid gels,traces of crystalline structure can be detected, but not in thetypical organic colloids, such as albumin, gelatin, cellulose, starch,and the like.43It, has been pointed out that it is a necessary consequence ofthe modern views of crystal structure that, in certain cases, thechemical composition of the crystal must depend on its size.Thusiron pyrites, with a space-lattice consisting of an atom of sulphurwithin a cube, four alternate corners of which are occupied by ironatoms, instead of the formula FeS, must possess a compositiongiven by Fe(n+l$z2n::, where n is the number of elementary cubesin the crystal. I f n is 50, the particle would still be visible bythe aid of the ultramicrosoope, and its composition would be givenby FeS,.,,,.44a-Rays.The Geiger-Suttall Relation.-The logarithmic connexioiibetween the period of average life of an atom and the range ofthe a-ray expelled from i t during disintegration, and the theoryo€ the cause of atomic disintegration to which it has led, have beenthe subject of closer examination.On this the0ry,~5 the instabilityof the atom is supposed to result from the simultaneous conjuiic-tion of a large number, N , of separate particles, moving independ-ently of one another within the atomic nucleus, in a certain favour-able relation. The chance of disintegration depends on somethinglike the one-hundred-and-sixtieth power of the velocity of thea-particle expelled, and suoh a law can scarcely be explained exceptas an expression of the probability of the fortuitous occurrence ofa very large number of independent events.The actual value first deduced from the periods and ranges forAT was about 80, a nuniber of the same order as the atomic number.The relation between range and period on this theory becomeslog A =Na + &?V log R ,where R is the range and a is, approximately a t least, a constant.From new data on the ranges of some of the members of thevarious disintegration series, values for L7\T, 81, 77, and 71, havebeen assigned for the uranium-radium, thorium, and actiniumseries respectively.46 Clearly these must be of the nature of mean43 P.Scherrer, Nachr. Ges. Wiss. Gtittingen, 1918, 96 ; A . , 1919, ii, 274.44 A. Quartaroli, Gnzzetta, 1920, 50, ii, 6 0 ; A., ii, 609.45 Ann. Reports, 1916, 13, 257.46 S.Bloyer, V. F. Hess, and F. Paneth, Sitzungsber. Akad. Wiss. Wien,1914, 123, 2n, 1459; S. ? r l e y ~ , ibid., 1916, 125, Za, 201.I234 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.values, since the number of independently moving particles in thenucleus must diminish by unity with each a- or &particle expelled,that is, with each step in the disintegration series. The experi-mental numbers given for the uranium-radium and the thoriumseries agree with the mean values to be expected if the atomicnuclei are practically composed of helium nuclei and bindingelectrons. Thus for thorium, with atomic weight 232 and atomicnumber 90, 58 helium nuclei and 116-90=26 binding electronswould constitute a system consisting of eighty-four independentunits.The value of N for thorium itself would be one less, sincethe probability relation holds between one of the particles and therest of the nucleus. The mean value for the series between thoriumand thorium-C, considering N to be reduced by unity for eaoh a-and for each &particle expelled, would be 78 instead of the valuefound, 77. For the uranium atom, with atomic weight 238 andatomic number 92, two hydrogen nuclei a t least must be postulated.I f there are only two, there must be 59 helium nuclei and118+2-92=28 binding electrons, making a total of 89 inde-pendent particles. The mean of the number, diminished by one,is, for the series uranium to polonium, 81 or 82, again in excellentagreement with the experimental value.If, now, the correct values for N are introduced for eachmember of the series, and the value of the constant a calculated,i t is found that a is truly constant for the middle members ofeach series, but is markedly, although not greatly, different forthe first and last members of each ~eries.4~ The actinium series isscarcely yet worth consideration here, as, in absence of all experi-mental evidence as to the atomic weights of its members, the valuesto be assigned to N must be a matter for speoulation.I n addition,i t obeys the logarithmic relation only very imperfectly. Thedifficult question as to the cause of the disintegration of the atomin radioactive changes seems at least to be progressing towards asatisfactory and highly suggestive answer.I n other papers, Bohr’s principle of angular momentum has beenapplied t o the internal economy of the nucleus, and the conclusionreached that the motions of the particles remaining in the nucleusare not affected by €he successive steps in the atomio disintegration.The radius of the orbit of revolution of the a-particle in thenucleus before expulsion has been calculated, and found to diminishby steps with each successive disintegration.**A collection of papers has appeared on the counting and photo-47 G.Kirsch, Physikal. Zeitsch., 1920, %, 452 ; A., ii, 577.48 H. T. Wolff, ibid., 175, 393 ; A., ii, 366, 578RADIOACTIVITY. 235graphic registration of a-particles. The eleotrometer method,using high potential gradients just below the sparking potential,whereby the ionisation is enormously magnified by collision, hasbeen the one employed.As the most suitable gas for filling thecounting chamber, a mixture of 54 per cent. of carbon dioxideand 46 per cent. of air was used. It was found that a mixtureof carbon dioxide and air, with the former in excess, respondedonly to the a-rays, and not to the p- and y-rays.A new determination of the number of a-particles expelled persecond per gram of radium (element), free from disintegrationproducts, gave 272( k0.02) x 1010. In arriving a t this value,80,000 a-particles were counted. This is about, 4 per cent. abovethe previously accepted value, even after oorrection in terms ofthe International Standard.49I n a special research, it was found that 1.5 milligrams persq.cm. of mica, of density 2.87, correspond, in stopping powertowards a-rays, with 1 cm. of air a t 760 mm. and 1 5 O . 6 0The individual intervals between the emission of u-particles bypolonium have been systematically studied by photographicregistration methods for the case of 10,000 emissions. The require-ment of the theory of probability was very exactly verified. Thefraction of the total number of intervals of duration greater thanT is E - @ ’ ~ , where 8 is the mean interval. For very short intervalsthe law is departed from, owing to the emission of a-particles withintervals between them too small t o be distinguished by the meansemployed. From the results obtained, the number of such‘‘ doublets ” could be very exactly evaluated.51An effeot, analogous to the ‘‘ spluttering” of metals under theaction of the cathode rays in discharge tubes, has been observedwith a-rays for the noble metals nickel and aluminium, but notfor such metals as copper, the surface of which is easily oxidisedby the action of the atmosphere.Another effect due to a-rays wasobserved with polonium, electrolytically deposited on metal foil.The a-particles emitted .at grazing incidence appear to “ knock off”the polonium in aggregates of several molecules a t a time, causingan effeot analogous to the volatilisation of the polonium, which iscalled “aggregate recoil.” The effect is very much more pro-nounced in a vacuum than in the atmosphere. It is greatest withfreshly deposited preparations, and diminishes with their ags.*II Ann.Reports, 1914, 11, 274.bo R. W. Lawson and V. F. Hem, &kung.&er. dkad. W&. Wkn, 1918,121,61 (Mrne) 116. Curie, J . Phyrr. Radium, 1920, [viJ, I, 12 ; -4., ii, 727.3a, 406, 461, 636, 699, 943.I* 236 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The most regular results are obtained with palladium and platiiiuuifoils electrolytically saturated with oxygen. Saturating withhydrogen diminishes the effects and makes them irregular .52y-Rays.In a continuation of the researches fully described in the lastRep0rt,52~ two types of secondary y-rays, referred to as S; and S,,have been found to be associated with the two primary componentsof the y-rays of radium, designated as K , and K,.The first isof the nature of a scattered primary, possessing the same coefficientof absorption as K,, and distributed with deoreasing intensitywith increasing angle of scattering. None is detectable a t anangle of 90° or beyond, or, in other words, this secondary radiationis confined to emergence. For this type, the scattering power ofdifferent atoms is proportional to their atomic number. The typeS2 is, in general, different in penetrating power from K,, and isscattered over an angle of 180°, constituting an incident, as wellas emergent, radiation. For light atoms the scat’tering is pro-portional to the atomic number, but for heavy atoms to the squareof this number.53 The absorption of divergent beams of y-rays hasalso been studied, with the view of throwing light on the reasonwhy y-rays, although complex and scattered, so nearly obey thetheoretical law of absorption to be expected for a homogeneous,non-scattered beam.54Methods have been developed for ‘‘ oounting ” y-rays analogousto those referred to under “a-Rays.” The effect of a y- or B-rayis, in general, twenty to twenty-five times less than that of ana-ray, but with a sufficiently sensitive counting arrangement theymay be counted with ease and certainty.Some special precau-tions are taken, on account of the high potential necessary torender the response very sensitive, but otherwise the arrangementsare very much as for the a-rays. The gas used in the countingchamber is air, drawn from the free atmosphere and stored oversulphuric acid until any emanation initially present has had timeto decay, and filled into the chamber through cotton wool andphosphorio oxide.The y-ray acts by liberating a high-velocity &particle from themetal walls of the counting chamber, and the same methods are52 R.W. Lawson, Sitzungsber. Akad. Wiss. Wien 1918, 127, Za, 1315;1919, 128, 2a, 795.52a Ann. Reports, 1918, 15, 211.53 K. W. F. Kohlrausch, Sitzungsber. Akad. Wiss. Wien, 1919, 128, 2a, 853.Ann. Reports, 1918,15,213 : M. Blau, Sitzunpber. Akad. Wiss. Wien, 1918.127, 2a, 1253RADIOACTIVITY. 237equally applicable for /3- as for y-rays. It was found that thenumber of y-rays given per atom from radium-B and radium-C,respectively, were practically the same. The total number ofy-rays from both together is, in terms of the number of a-particlesfroin radiund', between two and 0ne.55C'lzemical Actions of the Rays of Radimm.The reactions prooeeding in common gases, when mixed withradium emanation, and due to a-rays, have been the subject of twoexhaustive investigations, chiefly to ascertain whether the facts arein agreement with the theory that the reactions obey a form ofFaraday's law, that the molecules formed in the reaction are equalin number to the pairs of ions formed from the rays in the gas.56I n one research, four gases, hydrogen sulphide, ammonia, nitrousoxide, and carbon dioxide, were studied.Other conditions beingthe same, the amount of decomposition is proportional to theamount of emanation present.The decomposition increases as thesize of the reaction vessel is increased, to a limit correspondingwith the state in which praotically the whole of the energy of thea-rays is spent in traversing the gas molecules. For hydrogensulphide, the thermal coefficient of the velocity of reaction is prac-tically zero from -180° to 1 8 O , and above this, to 220O; is slightlynegative. For nitrous oxide, the reaction proceeds probably intwo directions, for the most part with the formation of nitrogenand oxygen, but also with the formation of nitric oxide andnitrogen. The accumulation of nitrogen peroxide as a result ofthe second reaction retards the reaction. Here, again, changes oftemperature producie but a slight effect on the velocity of reaction,the coefficient being negative below and positive above 1 8 O .Forammonia, the coefficient is positive and considerable up t o 220O.Carbon dioxide was found t o undergo oiily a very slight decom-position, and the rapid change recorded by other investigators isattributed to the effect of mercury and phosphorus in the vessel.For these reactions, Faraday's law was found not to apply. Theratio between the number of molecules produced and the numberof pairs of ions formed by the a-rays exceeds unity in cases whereno catalytic acition is involved.57I n the other research, the combination of hydrogen arid oxygenwas re-studied. Here it was found that 3-92 molecules of waterresult for every pair of ions formed in the gas. It appears that" V.F. Hess and R. W. Lnwson, Sitzungsber. Akad. Wiss. Wien, 1916,125,2% 285, 585, 661. '' E. Wourtzel, I;e Radium, 1919, 11, 2139, 332; A., ii, 214.GG Ann. RrpoTts, 1912, 9, 323238 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in all the earlier results of Ralusay and Cameron, which gave sup-port to the ionisation theory, the amount of emanation used hadbeen much overestimated. It had been calculated from the timeof accumulation and quantity of radium, which, since the develop-ment of exact methods of measuring the emanation by the y-rays,is known to be quite untrustworthy. The velocity of reaction wasfound to be proportional to the quantity of emanation and in-dependent of the temperature. It was increased by inorease ofoxygen above the stoicheiometrical proportion, the velocity ofreaction continuing to rise as this excess increases with the reaetion, and diminished by increase of hydrogen, the velocity con-tinuing to fall as the excess of hydrogen increases.This is to beexpected from the ionisation theory, since the relative ionisationsin oxygen and hydrogen are as 1-09 to 0.24, that of air being unity.In very small vessels, particularly at low pressures, the velooityof reaction is abnormally high. This is ascribed to the atom ofradium-A, recoiling from the atom of emanation, bringing aboutthe combination in the same way as an a-particle. Under themost favourable conditions for magnifying this recoil effect rela-tively to that produced by the a-rays, i t may exceed the latter sixor seven times.The relative effect produced is in agreement withthe data as to the magnitude of the ionisation produced by recoilatoms.With the single exceptioii of hydrogeii and chlorine, where thechemical action may be several thousand times as great as theionisation theory requires, i t is claimed that there is a generalstatistical agreement between the iiuiiiber of ions and the numberof molecules produced for a large number of reactions. The twonumbers are not the same, but they correspond within a inultiplierof a few units only in either direction. This is true for reaotionsproduced by the cathode rays and @rays, as well as those resultingfrom the action of a-rays and recoil atoms. The ratio of four toone, in the present case, between the numbers of the moleculesand ions can be explaiiierl by ionic possibilities, without recourseto other theories.6*In the reverse reaction, the dercmposition of liquid water bythe a-particle into hydrogen and oxygen, about one molecule ofwater is decomposed per pair of ions formed.In practice, thereoombination of hydrogen and oxygen under t.he action of theemanation proceeds almost t o completion a t constant volume,because the water condenses to droplets, and so is removed for themost par! from the action of the a - r n y ~ . ~ ~5 3 S. C. Link J . Amer. Chem. SOC., 1919, 41, 531, 551: A., 1919, ii, 210.6 9 Idem, Tram. Amer. Etectroch-mn. Soe., 1918, 34, 211RADIOACTlVITY. 239The long series of parallel experiments on the action of thepenetrating rays of radium and of ultra-violet radiation from aquartz mercury lamp on organic substances has been continued.The substances studied comprise a mixture of maleic and fumaricacids, solutions of formic and benzoic acids and of carbamide, dryand wet toluene, chloroform, and carbon tetrachloride.Theeflects of the two kinds of irradiation are, in general, similar, theultra-violet light being usually almost incomparably the morerapid. The results bear out the general view that these agentshave a shattering effect on almost all molecules, followed bynumerous secondary reactions among the products.GOThe thermoluminescence and decolorisation of glass which hasbeen exposed to the rays of radium, on heating, have been shownto be independent of one another.For freshly exposed glass,thermoluminescenaa starts on heating below looo, and a t 200° forspecimens exposed some years previously. Decolorisation does not,however, occur until the temperature of 500° is reached.61 Thecolorations and thermoluminescence produced in a great variety ofminerals have been examined. The fluorspars, by reason of thealmost bewildering variety of colour changes they undergo and thebrilliance of the thermoluminescence produced, are among themost interesting.@ I n this connexion, the variety of fluorsparfrom Wolsenberg, Bavaria, locally called " Stinkfluss," deservesspecial mention. On being crushed, it emits a peculiar odour, whichthose who have made a careful study of the mineral assert is with-out doubt due to free fluorine.Radium rays easily reproduce thenatural dark blue colour in the mineral after the colour has beendischarged by heating, but do not restore its odoriferous quality.63Studies of Radioactive Minerals.Age of Thorium Minerals.--In a careful review of the difficultquestions connected with the age of thorium minerals, both theisotopes of lead derived from thorium are regarded as stable,and the age of the mineral, A , is deduced from the formulaA = Pb x 7,9?0 million years,U + 0-384 Thwhere Pb, U, and Th are the percentages of these elements in the6o A. Kailan, Zeitsch. ph?~&al. Chem., 1920, 95, 215 ; A., ii, 576 ; &tzungs-ber. Akad. Wias. Wkn, 1919. 128, 2a. 831 ; 1917, 126, 2n, 741.61 5. C. Lind, J .Phys&ccrl Chem., 1920, %, 437 : A., ii, 576.E. Newbery and H. Lunton, Mem. Manchpster Phil. S'oc, 1918, 62,No. 10; A., 1919, ii, 130.B3 F. Henrich, Zeitsch. angew. Chem., 1920, 33, 5, 13, 20 ; A., ii, 216240 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.mineral. The conclusion is reached that in (1) the Middle-Devonian formation a t Brevig, Norway, in the Precambrian form-ations of (2) Arendal-Gegend, Norway, and (3) Moss, Norway, and(4) in the thorianite-bearing pegmatites of Ceylon, all thoseminerals with less than three times as much thorium as uraniumgive quite concordant ages for the formations, namely, (1) 300,(2) 1300, (3) 950, (4) 500 million years, respectively. These mustbe regarded as true primary minerals; but all those for which theTh/U ratio is greater than 3 give smaller ages, and must beregarded as secondary minerals derived from the primary byvarious processes of change in which the content of thorium hasbeen enriched.I n the first class are to be found, in (1)eudidymite, eucolite, zircon, pyrochlor, and biotite, in (2) clsveite,in (3) broeggerite, and in (4) pitchblende and thorianite, whilst inthe second class are, in (1) freyalith, thorite, and orangeite, in(2) uranothorite and orangeite, in (3) uranothorite of Rittero,and in (4) thorite. The atomic weights of the lead from the threevarieties of thorianite, already given, conform well to the viewthat they are primary constituents of the pegmatite, which has anage between 400 and 500 million ~ e a r s .6 ~The ratio of thorium to uranium in a number of minerals hasbeen determined by radioactive methods. I n Morogoro pitch-blende there is 0.5 per cent. of thorium and 74.5 per cent. ofuranium ; in pitchblende of St. Joaohimsthal, per gram of uranium,4.68 x 10-5 grams of thorium, making, with the estimated1-96 x 10-5 grams of ionium, a total 6-64 x 10-5 grams of thoriumisotopes. A monazite sand of unstated origin, containing 7.23 percent. of thorium, was found to contain 0.087 per cent. ofuranium.65 I n another estimation, monazite sand from Brazil wasfound to coiitain 0.8, and from India Oa102 ( x 10-9 gram ofradium per gram). These correspond with 0.235 and 0.03 percent. of uranium respectively, and, on a thorium content of 4 and9 per cent., mesothorium preparatioiis obtained from them wouldowe 28 and 2.1 per cent., respectively, of their initial y-aotivity tor a d ium .66In a nlonograph on broggerite, which contained 63-66 percent.of uranium, 6-6.5 per cent. of thorium, 9.5-10 per cent.of lead, and 0-7-1.5 per cent. of rare earths, hydrofluoric acidG 4 R. W. Lawson, Sitzungsber. Akad. Wiss. Wien, 1917, 126, 2n, 721;G5 S. Mttyer, ibid., 1919, 128, 2a, 897 ; A . , ii, 548.06 J. E. Underwood and H. Schlundt, Trans. Amer. Electrochem. SOC.,(Tn the abstract, lo-' gram should read loA9A . , ii, 149.1918, M, 203; A., ii, 146.gram.RADlOACTIVITY. 241was found to be the best precipitant for thoriuin in presence ofuranium. As is well known, the niethod of separation based onthe solubility of uranium nitrate in ether or acetone is useless.The Pb/U ratio in this mineral is essentially constant a t 0.12 to0.13, which corresponds well with the age of about a thousandmillion years, already given, for the pegmatite dykes in the granitesof Moss, Norway, from which it is obtained.67T h e I;runizc?n-Radizcn Rcrtio .--This important ratio has beenredetermined for a carefully seleoted Colorado pitchblende.Theuranium was estimated analytically, and the radium by theemanation method against specially made absolute standards ofradium. These were prepared, by dilution to 1.5 x 10-9 grams ofradium per c.c., from a radiuin chloride of 100 per cent. purity,measured against. the International Standard by y-rays. A milliontimes the quantity of barium was added to the diluted standardto protect, the minute amount of radiuin from precipitation.Theresult gave 3.4 x 10-7 grams of radium as the quantity in equil-ibrium with 1 gram of uranium. This was the original “Ruther-ford-Boltwood ” value, but it was subsequently corrected t o3.23 x 1 0 - 7 on the Internatioiial Standard. Much independent)work has shown that the uncorrected value was substantiallycorrect, and it is very satisfactory t’o have had this oonclusioiiconfirmed so convincingly.68Relative a-Activities of FULII iu?n, t m t l Rndium. --Many pointsremain to be cleared up with regard to the relative a-activities ofradium and uranium minerals. A new determination has sub-stantially confirmed the original determinations.Taking theactivity contributed by uranium (U-I and U-77) as unity, thetotal activity of the mineral is now found to be 4.73 instead of4.69, and the part due to radium itself as 0.488 in place of 0.45.I f , however, the radium were produced from the uranium in adirect line without branching, its a-ray activity, calculated fromthe law that the ioiiisation is proportional to the two-thirds powerof the range of the a-particles, should be 0.57. The value found,0.488, can only be accounted for if the actinium braiich claimseither 26 per cent. of the atonis disintegrating if it starts fromuranium-I, or 14 per cent. if i t starts from uranium-11. Fromthe proportion of the total activity contributed by the actinium6 7 E.Cleditsch, Archiv for Mathematill: og A-atitrvideiLsTcnb, Christianiu,1919,36, Nr. 1 ; compare A. Fleck, T., 1913,103, 384.6 8 S. C. Lind and L. D. Roberts, J . Arne?.. Chem. Soc., 1920, 42, 1170 ;A., ii, 463 ; compare Becker and Jannasch, Jahrb. Radioaktiv. Elektronik,1915, 12, 1 ; F. Sod+- and (Miss) A. F. R. Hitchens, Phil. Mag., 1915, [vi].30, 218 ; A., 1915, ii, 726 ; E. Gleditscb, Zoc. cit242 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.series, estimated from both the new and the old measurements as0.26 to 0.28 in terms of that of the uraniums as unity, a branch-ing factor of 8 per cent. for the actinium series has hitherto beenaccepted, but work about to be considered has reduced this to3 per cent. or less, so that a real inconsistency between the experi-mental data and our theoretical interpretation exists, the clearingup of which might throw much light on the branching of theseries.69The Uranium-Actinium Ratio.-In a study of the pitchblendesof Morogoro and St.Joachimsthal, broeggerite from Norway, andtwo thorianites from Ceylon, representing extremes of Th/U ratio,the constancy of proportionality between radium, and thereforeuranium, and actinium has been confirmed. Since the thorium-uranium ratio varied between the limits of 6x10-5 and 6, theindependence of actinium and thorium, and the genetic connexionbetween actinium and uranium, follow.70The Uranium-X-Uranium-P Ratio.-For uranium derived fromthe same materials, the constancy of proportionality in the ratesof production of uranium-X and -P was established, and the geneticconnexion extended to the supposed first member of the actiniumbranch series, uranium-P.In this work, periods of average lifefor uranium-X, of 34-37 days, and for uranium-P of 35.53 hours,were found. The former is slightly, and the latter considerably,less than the previously accepted values, namely, 35.5 days and52.8 hours.The method adopted for separating from uranium theuranium-X, and -P, both being isotopes of thorium, consisted inneutralising the strong uranium solution with sodium hydroxide(not potassium hydroxide or ammonia) and adding a small quantityof a solution of a cerous salt and hydrofluoric acid. The cerousfluoride carries down with it the thorium isotopes, and is redis-solved in hydrochloric acid.A milligram of dissolved zirconiumis added, and the solution is precipitated with a solution of sodiumhydrogen hypophosphate, NaHB03,3H,0, according to the methodof Koss. This precipitates the thorium isotopes with the zirconiumand' leaves the cerous salt dissolved. The relative activity ofuranium-X, and -P proved to be independent of the source of theuranium, and from i t a branching factor for the actinium seriesof a t most 4.2 per cent. was ded~ced.~1an Ann. Reports, 1909, 6, 259 ; J. H. L. Johnstone and B. R. Boltwood,Phil. Mag., 1920, [Vi], #, 50 ; A., ii, 523.70 S. Meyer 8nd V. I?. Hess, 8itzung8ber. Akad. Wiss. Wkm, 1919, 128, 2a,909 ; A., ii, 658.71 G. Kirsch, ibid., 1920, 129, 2a, 309; compare M.Ross, Chem. Zeit.,1912, 36, 686 ; A,, 1912, ii, 809RADIOACTIVITY. 243Parent of A ctznium-Details have been published of the separ-ation of the direct parent of actinium, proto-actinium or eka-tantalum, from pitchblende residues.72 By prolonged and repeatedtreatment with nitric acid, the other radioactive constituents,including radium, may be almost completely removed. A littletantalum oxide is then added, and the material extracted withhydrofluoric and sulphuric acids. The addition of a few milli-grams of thorium and lead nitrates a t this stage serves to keeptraces of ionium, uranium-S, and radio-lead in the insoluble form.The filtrate is evaporated to dryness, which leaves the tantalumand proto-actinium in an insoluble form, from which impurities,such as iron, zirconia, and the like, may be removed by boilingwith aqua regia.So far, all attempts to separate proto-actiniumfrom tantalum have failed.By various elaborations of this method, the whole of the proto-actinium from pitchblende containing a known amount of uraniumwas carefully separated, and its a-activity measured. If thebranching factor of the actinium series were 8 per aent., the pre-paration should have an a-activity equal to 4 per cent. of thatof the uranium in the mineral. As a mean of six determinations,i t was found that the branching factor was only 3 per cent. Thecompleteness of the separation and the avoidance of loss duringthe chemical treatment were proved by carefully chosen tests witha previously prepared and measured preparation.Period of A ctinium.-From these proto-actinium preparations, anew and independent determination of the life of actinium wasarrived a t in the following manner.From the known ranges ofthe six a-rays of the actinium series, including that of proto-act'inium, i t follows that the initial a-activity of proto-actiniummust be in the ratio 1 :5.74 to the a-activity of the substance afterequilibrium with the five a-ray-giving members of the actiniumseries has been attained. The proportionate increase of thea-activity over periods from 400 t o 600 days corresponds with ahalf-period for actinium of 20 years, or to a period of average lifeof 28.8 years. This is in good agreement with the further resultsobtained by observations on the decay of activity of actinium itself.so that the period of actinium may now be regarded as known withreasonable certainty.7372 Ann.Reports, 1918, 15, 195.'s 0. Hahn and L. Meitner, Ber., 1919, [B], 52, 1813; '4., ii, 147, 148 ;PhyeikaE. Zeitsch., 1919, 20, 529 ; d., 1919, ii. 209244 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY.Various.Radioactivity of Rubtdiun~.-An exainination of the very feeblypenetrating B-aotivity of rubidium compounds has confirmed theview that it is an atomic property of rubidium, and is unaffectedby chemical purification or treatment. The rays are somewhatinore penetrating than those of uranium-X1,[pA, =347 - 308(cm.)-],as compared with 463 for the B-rays of uranium-S, and 312 forthose of radium].Their velocity is estimated as 0.6 that of light.The activity is feeble. A surface covered with 0.025 gram ofrubidium sulphate per sq. cm. possesses the same activity as onecovered with’ 0.00033 gram of uranium oxide per sq. cm. (totalP-rays) . Eliminating the penetrating &rays of uranium-X2, andextrapolating to a film of zero thickness, so correcting for absorp-tion, i t is estimated that the speoific activity of the elementrubidium is one-fifteenth of that of uranium, due to the change ofuranium-X,. The product of the change, if the normal law isfollowed, should be an isotope of strontium. It is suggested thatthe search for calcium, strontium, and cesium, respectively, inminerals containing potassium, rubidium, and czsium, and thedetermination of their atomic weight, if foulid, might throwfurther light on the radioactivity of the alkali metals.i4Changes in the Radioactivity of the Oxides of r/mnium.-Sonieresults in this field incompatible with the present theory of radio-activity have been recorded.The a-activity of various prepar-ations of oxide of uranium showed a diminution over a term ofyears from 1 to 31 per cent. The greater decreases occurred withthe green oxide, prepared by the gentle ignition of ammoniumuranate, and the smaller with the black oxide, obtained by strongignition of the nitrate, preparations of intermediate colour show-ing intermediate behaviour. I n a preparation the a-activity ofwhich had fallen from an initial value 5.95 to 4.64, the initialactivity was restored by solution in nitric acid and ignition.Itis unfortunate, perhaps, that no changes of weight of the prepar-ations were looked for, for such results might be due to the possible,although hitherto unobserved, gain of oxygen or moisture by thefeebly ignited green oxides from the atmosphere. On the otherhand, from the impurities separated from the uranium, increasesin a-activity from 7 to 93 per cent. were observed, the rate ofincrease in one case corresponding with a period of 1.1 months75’* 0. Hdm and RI. Rothenbach, Physikal. Zeitsch , 1919, 20, 194 ; -4..1919, ii, 312. 75 C. Stsehling, Con~pt. rend., 1919, 169, 1036; A . , ii, 5R AD I0 A CTI VIT Y . 245Period of ZO?LZUTIL.--T~~ minute growth of radium froin largeamounts of carefully purified uranium, already recorded, has sinoeproceeded regularly according to the square of the time, and adefinite estimate of the period of ionium can now be deduced -fromthe measurements.This is the same as that already provisionallycalculated. Actually, the product of the periods of average lifeof ioiiiuni and radium alone is involved, and this, to an uhcertaintyof a t most 5 per cent., is 237,500,000 years. The period of ioniumis thus 100,000 years if that of radium is 2375 years. The actualgrowth of radium from 3 kilograms of uranium (element) in10 years has been 2 x 10-10 gram.76Fractional Crystallisation of Rczdium and ilfe.sothorium fromBarium.-The theory and practice of the enrichment of radiumand inesothorium from barium in the fractional crystallisation ofthe chloride and bromide has been the subject of two communica-tions. The enrichment factor, K , is defined as the ratio of theactive material in the crystals to that in the original material inthe solution.As regards the chloride, K varies from 1-65 for anacidity 0.25~1-, with 44 per cent. of the salt crystallising, to 1.49for an acidity 2X, with 58.3 per cent. crystallising. The condi-tion chosen for study was O*5riT-acidity, with 50 per cent. crystal-lising, for which K is 1.62. For the bromide, the value of R fellfrom 2.60 for O.25iT-acidity and 30 per cent. crystallising, to 2.45for 1.ON and 38.2 per cent. crystallising. The condition chosenfor further study was O.33N-acidity and 33.3 per cent.crystal-lising, for which K is 2-5. The enrichment factor is independentof the relative concentration of radium or radium and meso-thorium in the solution. From the second communication itappears that, so long as the same fraction of crystals separate, itis independent of acidity. As already known, the bromide offersadvantages over the chloride in speed of separation, especially inthe earlier stages of the separation. Some evidence was obtainedof t3he formation of a compound, RaBr2,2BaBr,,6H20, as the finalproduct of the fractionation in a weakly acid solution, correspond-ing with 39 per cent. of anhydrous radium bromide, which wouldexplain the advantage of the chloride over the bromide in thelater stages of the purification.On the other hand, in verystrongly acid solutions, above 2W, and very small concentration ofthe radium, below 10-7, the process is actually reversed, and moreof the radium remains in the mother liquor than separates outwith the crystals.The most favourable method of carrying on the fractionation76 Ann. Reports, 1916, 13, 249; F. Soddy, Phil. Mag., 1919, [vi], 38, 483;A., 1919, ii, 443246 ANNUAL REPORTS ON THE PROGRESS OB CHEMISTRY.in practice is by a system in which the crystals and mother liquorsmove one step in opposite direations in the series a t each crystal-lisation, except for the fractions enriched above the initial con-centration, the mother liquors from which move two steps. Insuch a system carried out continuously, representing the initialconcentration as unity, the series runs as shown, the figuresrepresenting the concentrations in each unit of the system: 77Mother liquor +-- + +- + +--- +--f------ +--+ 0.0016 0.008 0.04 0.20 1.0 2.3 5.0 12.3 27 +Crystals + ++ -++ -+- + -+ + +In another study of mesothorium-radium-barium bromides, theactivities were determined by y-ray methods.The value of K wasfound to vary from 2.57 with 24.3 per cent. crystallising to 1'44with 69 per cent. arystallising.78Solubility of Radium Emanation.-Two series of determinationsof the solubility of radium emanation in organic solvents, for themost part, have appeared. The solubility in these is much greaterin general than in aqueous liquids, and increases as the hydro-carbon character of the solvent predominates over the aqueous,rising steadily, for example, in a series of aliphatic alcohols oracids.79 A new determination of the coefficient of diffusion of theradium emanation in water a t 14O gave the value 0.82 cm.perday, which corresponds with a molecular diameter of 1.85 A.80The value deduced from the space-lattiae of crystals was abouttwo-thirds of this.y-A ctivity of Thorium-D.-The conclusion that in a thoriummineral 36.3 per cent. of the y-radiation is due to mesothorium-2and 62.7 per cent. to thorium-l)*l has been confirmed by a com-parison of the y-activities of quantities of the two products inequilibrium with the same quantity of thorium. The y-activitydue to thorium-l) was found t o be 1.81 times as great as that dueto mesothorium-2.Since only 35 per cent. of the thorium atomsdisintegrating produce thorium-D, it follows that, atom for atom,thorium-D gives 5.17 times as much y-radiation as mesothorium-2.From these data, a table of the changes of the y-activity of a puremesothorium preparation with time has been constructed. I f the7 7 C. E. Scholl, J . A ~ T . Chem. Soc., 1920. 42, 889; A., ii, 408.7 8 J. L. Nierman, J. Physical Chem., 1920. 24, 192 ; A., ii, 408.'4 Alfred Schultze, Physikot. Zeitach., 1020, 95, 257 : G.80 E. Ramstedt, Medd. R. Vetewkapsakad. Nobel Inat., 1919, 5, No. 6 ;A., ii, 577 ;Hofbauer, Sitzungsber. Akad. W~RU. Wkn, 1914, 123, 2a, 2001.A., ii, 72. 81 Ann. Repork, 1918,15, 220RADIOA(JTIVITY . 24 7initial activity is unity, in three years it is 1.62, and in ten yearsunity again.8Natural Radioactivity.Bmss.-The improvements in the methods of recording thepassage of individual a-particles have been applied to theexcessively feeble natural radioactivity of common materials, andhave thrown light on the important question whether this is whollydue to known radioactive impurities or is in any part a specificactivity.A statistical examination of the a-particles emitted froma hollow brass sphere showed that a large number of the a-particlespossessed a very short range, shorter than that of any of the knownradio-elements. The rate of emission was one a-particle per sq.cm. of surface in 9'25 hours. The range of this new type wasestimated a t 1.8 cm. of air.By the Geiger-Nuttall relation, thisoorresponds with a period of life 1-5 x 106 times that of uranium.Hence the inference is formed that the a-particles are derived froman actual disintegration of the metal, either copper or zinc, withthis excessively long period of 1016 years. From copper an isotopeof cobalt, and from zinc an isotope of nickel, would result in ana-ray change. It is sad, however, that such elaborate andimportant physical experiments should be conducted on such amaterial as-brass !Rocks.-A survey of the radioaotivity of the rocks encounteredin the piercing of the Loetschberg Tunnel, which runs fromKandersteg to Goppenstein, in the Bernese Oberland, showedunusual similarity of composition along the length of the tunnel.This agrees with the fact that no abnormal temperature gradient,such as was encountered in the St.Gothard Tunnel, was experi-enced. The average of all the rocks (eighty-two specimens) was2*2( x 10-12 grams of radium per gram). The rocks a t theKandersteg end are Jurassic limestones, in the centre Gasterngranite, and, a t the southern end, crystalline schists of all classes.The granites were somewhat lower in radium content, and theaalcareous and schistose rocks somewhat higher, than the averagefor these c1asses.aThe rocks of the Kolar gold field, on the Mysore plateau,southern India, consist of schists of very uniform character, whichcontain as little radium as, and are probably older than, any rocksknown. The temperature gradient in the mines is abnormally84 H.N. McCoy and G. H. Carfledge, J . Amer. Chern. Soc., 1919, 41, 42g8 J. H. J. Poole, Phil. Mag., 1920, [vi], 40, 466 ; A., ii, 667.A., 2919, ii, 89248 ANNUAT, REPORTS ON THE PROGRESS OF CHEMJSTRY.low. The average radiuiii content was 0.19 x 10-12 gralll pergram.84Spring TTTatc.rs.--A survey of sixty Canadian mineral springs,and, later, of six hot springs a t Banff, Alberta, disclosed onlymoderate activities. The latter are the most active in Canada, andpossess an emanation content of from 2 to 6( x 10-10 curie perlitre). For the escaping gases, higher values, up to 24, wereobtained .s5 The springs of Colorado are exceptionally active, theemanation mntent for ninety-five exceeding 10, and for five 100.The most active, 305, is surpassed by few European springs.86The sulphur-soda springs of Bagn5res-de-Luchon have beenfound to be the most radioactive in France, and, apart from suchwaters as actually originate in uranium mines, to be exceeded inactivity by less than a dozen in the whole world.The group ofsome twenty-four springs possessed an emanation content between4 and 415, five being above 240, and higher than any other Frenchsprings. 87The principal spring at Bagiioles de l’Orne showed, over a monthof observations, variations in emanation content from 2 to 15.Previous observations had given much higher values, 24 in 1907and 113 in 1904. These variations have been traced to the rain-fall. After rain, at an interval varying from six to thirteen days,the springs in this neighbourhood were found to reach a maximuniemanation content, the greater the heavier the rainfall. Thisshows that the activity of the spring is derived from surface watersperoolating through radioactive strata and inixing with the deepspring water .88 Two papers dealing with the practical techniqueof such measurements have appeared .@The OcPmz.--The rate a t which radium is supplied to the oceanby rivers and the denudation of the land cannot maintain thequantity present. It follows that there must be in sea-wateruranium and ionium in equilibrium proportion to the radium.Taking the mean radium content of sea-water as 1.2 x 10-15 gramper c.c., the uranium must be 4 x 10-6 gram per litre of sea-water,or 0.1 milligram per kilogram of sea-salt.This is about one-tenthof the estimated content of gold in sea-water. On this view, noa4 H. E. Watson and G. Pal, J . Ind. Tnst. Sci., 1914, 1, 39 ; A., ii, 278.85 J. Satterly and R. T. Elworthy, Trans. Roy. SOC. Canada, 1917-1918,[iii], 11, 17, 27 ; 12, 153 : A., 1919, ii, 41, 72, 312.8 6 0. C. Lester, Amer. J . Sci., 1918, [iv], 40, 621 ; A., 1919, ii, 6.8 i A. Lepape, Compt. rend., 1920, 171, 731 ; A., ii, 727.** P. Loisel, ibid., 1919, 169, 791 ; 1920, 171, 858; A., 1919, ii, 489 ;0. Niirnberger, Physikal. Zeitsch., 1920, 21, 198; A., ii, 345; H1920, ii, 727.Greinacher, ibid., 270 ; A . , ii, 463RADIOACTIVlTY. 249great variation of radiuni coiitent with depth is to be anticipatedin the ocean. It is calculated that the ooean and the land mustbe approximately equal factors in maintaining the amount ofenlanation in the atmosphere, the smaller contribution of the oceanper unit of surface being oounterbalanced by its greater area.90The A tmosphere.-At Innsbruck, as the result of forty-nineobservatioiis of the emanation content of the atmosphere by thecharcoal method, values were obtained between 1110 and 43, witha mean of 433( x 10-15 curie per litre), whioh are considerably abovethose found in other 10calities.~~It will be recalled that in 1912, during balloon ascents, anincrease in the penetrating radiation of the atmosphere wasrecorded, which became considerable a t the height of 3000 metres.92Now kite experiments, carried out a t the aeronautical observatoryof Lindenberg, Prussia, have shown that the active deposit on awire under the influence of the earth's field is much greater a theights between 1000 and 2500 metres than a t the surface. Astudy of the variations of this from July 29th to December 2nd,191 3 (ninety-eight observations), showed that strong increasesoccurred with the fall of the barometer. Since, a t this height, thesupposed explanation of the influence of the fall of the barometricpressure in facilitating the escape of emanation from the surfacesoil fails, the changes of activity and pressure are regarded asoriginating in a common cause. A clear parallelism was found t oexist, between the changes of the activity and what is termed the'' potential temperature " of the layer of the atmosphere between1000 and 2500 metres. By this term is meant the temperaturewhich the air would assume if adiabatically brought to normalpressure. Presumably the changes of this function are independentof internal ineteorological influences, and are a measure of theexternal solar influences. However that may be, temperaturechanges are supposed to be the cause of the pressure changes, andthemselves to originate from a inass radiation from certain limitedzones of the solar surface of eniaiiation particles into the upperatmosphere, which owes t o this its chief source of heat. What-ever the explanation may prove to be, the study of the radio-activity of the upper atmosphere is clearly likely to lead t oimportant advances.93 FREDERICK SODDT.IT. F. Hess, Sitztmgsber. ;1kad. Wiss. Wie)t, 1918, 127, ?a, 1297.91 R. Zlatorovic, Wien. Anz., 1920, 75 ; A., ii, 657.'' -4vn. Reports, 1912, 9, 327 ; 1913, 10, 288.y3 H. Bongards, Ph,ysikal. Zeitsch., 1920, 21. 141 ; A., ii, "7

ISSN:0365-6217    

DOI:10.1039/AR9201700217

出版商:RSC    

年代:1920

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INDEX OF AUTHORS' NAMESAbel, J. J., 172, 173.Adams, E. Q., 122.Adams, R., 54, 84, 102.Albrecht, W. A., 181.Allard, H. A., 193.Allison, F. E., 182.Alvarez, N., 142.Amatsu, H., 160.Ambard, L., 169, 171.Andersen, A. C., 155.Annett, H. E., 142.Archibald, E. H., 51, 146.Armstrong, E. F., 65.Arnold, H., 1%.Aron, H., 167.Aronberg, L., 225.Arreguine, V., 138.Asahina, Y., 113.Asano, M., 115.Aschan, O., 55, 81.Ashworth, J. R., 19.Aston, F. W., 31, 221, 225.Atanasoff, D., 194.A4udubert, R., 132.Suffenberg, E., 93.Auger, V., 146.Auwers, K. oon, 70, 100, 108.Bachmann, F. M., 167.Bacho, F. de, 145.Bader, W., 76.Badger, W. L., 134.BIrwind, H., 58.Bailey, (Miss) D.. 21.Baker, cf. C., 150.Baker, H. B., 43.Balke, C. W., 35.Baly, E.C. C., 9.Barbier, H.,. 122.Barendrecht, H. P., 169.Barker, T. V., 211.Barnes, E., 39.Bertlett, H. H., 195.Batuecaa, T., 35.Baude, W. A., 47.Baugh,man, W'. F., 148.Baume, G., 130.Baxter, G. P., 35, 148.Bayliss, W. M., 161.Becker, R., 96.Beckley, V. A., 176.Beckwith, C. S., 188.Beesley, R. M., 87.Bell, J., 68.Belladen, G., 42.Bellucci, I., 49, 143, 146.Berendt, W., 87.Rergengren, J., 232.Bergmann, M., 58, 64.Bernardini, L., 197.Berry, R. A., 194.Berthelot, A., 137.Besthorn, E., 116.Bewley, W. F., 181.Bezssonoff, N., 183.Biilmann, E., 149.Birckenbach, L., 36.Bizzell, J. A., 180.Blair, A. W., 179, 187,Blassman, N., 199.Blau, M., 236.Bliss, A. R., 142.Block, W., 131.Boer, S. de, 162.Borjeson, G., 36.Bcssenecker, F., 96.Bohlin, H., 204, 232.Bohn, R.T., 150.Rokorny, T., 193.Boltwood, B. B., 242.Bongards, H., 249.Bormann, E., 200.Bormann, K., 158.Born. M.. 2, 3. 4. 20. 23. 200.Bottomley, 'W.' B:, 168,Bougault, J., 141.Bourqnelot, E., 138, 170Boutwell, P. W., 165.Bowers, W. G., 132.1Sl., 196252 INDEX OB AUTHORS' NAMES.Boyd, H. G., 47.Bragg, W. L., 201, 205. 231.Brand, K., 92.Brauer, K., 138.Braun, J. von, 73, 84, 102, 103, 104.Brauner, B., 35.Bray, v17. C., 4%.Breazeale, J. I?., 189, 191.Briclta, (Mlle) M., 169.Bridel, M., 138. 170, 196.Brinkman, R., 133.Bronsted, J. N., 226.Broglie, M. de, 232.Browne, A. W., 46.Browning, K. C., 55.Briickner. K.. 40, 41.Buc, H. E., 139.Buddington, A.I?., 213.Burd, J. S., 188.Butler, G. S., 38.Callan, T., 140.Campbell, J. M. H.. 162.Cardoso, E., 29, 221.Carleton, P. IT., 132.Carnot, P.. 171.Caron, H., 138.Carter, E. G., 185.Carter, S. R . , 48.Cartledge, 0. H.. 247.Chadwick, J . . 218.Chapin, R. 11.. 141.Chapman, S., 226.Chattaway, F. D., 54.Chaudhuri. T. C., 95.Chelle, L., 138.Chemische Fabrik Buckau, 53.ChBneveau, C., 132.Chernoff, L. H., 138.Chesnut. V. K.. 196.Chick, (Miss) H.. 167. 168.Chiucini, .I.. 146.Chorley. P.. 105.Christie. A. V.. 187.Claisen. L.. 102.Clews, F. H., 48.Clover, A. 31.. 59.Cohen, C. S., 195.Colin, H.. 196.Comber, N. M., 178, 186Compin, L.. 143.Compton. K. T.. 17.Conant.. J . T3.. 98.Conzetti. A , . 93.Cook, i\.A . . 98.Corner, S. D.. 188.Cornubert. R . , 87.Cow. D.. 172.Cowie. C:. A , , 134.Crawford. C., 173.Crinis. M. tle. 132Crompton. H.. 59.Crowell, W. S., 41.Crump, L. M., 182.Csonka, F. A., 132.Cummings, M. B., 192.Curie, (Mme) M., 235.Cushny, ,4. R., 161.Cutler, D. W., 182.Dakin, H. D., 155.Dalal, V. P., 46.Dale, H. H., 164.Dalyell, E. J., 167.Dam, (Miss) E. van, 333.Davies, (Miss) A. C., 14. 15. 18.Uavies, H. W., 164.Davis, A. L.. 223.Davis, B., 16.Davis, H. S., 143.Davis, M. D., 143.Daynes, H. *4., 133.Dkbourdeans, L., 144.Debye, P., 1.Deisler, H., 45.Delf, E. M., 165.Demoussy. E.. 189, 190, 191.DenigBs, G., 143, 144.Dennis, L. &I., 39.Desha, L. J.. 133.Dey, M. L., 76.Dhar, S.N.. 76.Diels. O., 97.Die'trich, W.. 131.Dimroth, O., 86, 93.Dixon, R. H., 141.Dodge, F. D.. 145.Dominicis. A. de, 186.Dowell, C. T., 141.Downs, C. R . , 80, 184.Drew, H. D. K., 56.Druce, J. G. F., 146.Drummond, J. C., 164.Dubrisay, R., 132.Dudley, H. W., 172, 173.Diiesberg, M., 108.Dufraisse. C., 133.Dunnicliff, H. B., 38.Dunnill. P.. 43.Eberly, N. E., 41.Eddy, W. H., 142, 167.Rdson, H. A . , 194.Eggert, S.. 208.Ehringhaus. A . , 130. 210.Eisenlohr, F., 144.Eitel, W., 209.Ekeley, J. B., 138.Elektrizitgtswerk Lonza. 54.Eller, la7.. 176.Ellinger. -4., 158.Elsner, C . , 76.Elworthy. R,, T.. 134. 248INDEX OF AUEmmert, B., 106.Emmett, A. D., 167.Erlenmeyer, E., 62, 74.Esca'ich, -4., 151.Euler, H.von, 82.Evans, B. S., 147.Evans, C. L., 164.Evans, P. E., 121.Everest,, A. E., 195.&:we, G. E., 136. 138.Fajans, I<., 3, 4, 71. 200, 201.Farghw, R. G., 95, 115.Farmer, E. H., 90.Farmer, It. C., 55.Farmery, J . W., 55.Fazi, Remo de, 92.Fearon, IT. R., 158.Fedorov, E. S., 205.Feigl, F . . 142, 143.Yellers, c'. 33.. 182.Fenger, F., 173.Fenner, C . N.: 210.Fenton, J., 48.Fergusori, J . R., 212, 213.Fichter, F., 80.Fink, H., 125.Finks, A. J., 196.Fischer, 131.Fischer, E., 58, 64.Fischer, F . , 53.Fischer,. O., 122.Fishburn, H. P.. 135.Fisher, E. A . , 179.Flach, E., 59.Fleck, A., 241.Fleurent, E.. 190.Fleury, P., 145.Florence, G., 153.Florentin, D., 140.Foote, P. D., 5, 14, 15, 16. 19.Foreman, F.W., 157.Fosse, R., 171.Franck, H. H., 52.Franck. J., 13, 21.Frenkel, 171.Freudenberg. K., 85, 112.Freund, M., 108, 124.Fridericia, L. S., 162.Friedemann, O., 93.Friedrichs, F., 139.Fries, K., 93.Fuchs, F., 176.Fuchs, W., 76.Fiirth, K., 46, 228.Fujita, A., 113.Fulton, H. R., 183.Fulton, R. V., 146.Furman, N. H., 135, 150.Gadamer, J., 123.Ganassini, D., 139, 143.HORS' NAMES.Garcia, E. D., 138.Gardner, W., 186.Garn, W. von, 73.Garner, W. W.. 193.Garrard, 8. F., 54.Gaudefroy, C., 214.Gault, H., 74.Geisselbrecht, H., 116.Geldard, Mi. J., 48.Ghrard, P., 171.Gersdorf, C. E. F., 196Gettler, A. O., 137.Ghosh, J. C.. 24.Ghosh, P. C., 85.Gibson. C. S.. 58.Gibson, W. H., 131.Gies, V-. J., 195.Gillespie, L.J., 182.Gladding, G., 79.Glattf elder, A., 102.Gleditsch, E., 241.Gmelin, H., 50.Godon, F. de, 55.Gola, G., 197.Goldschmidt. S., 81.Gordon, H. B., 147.Goris, A., 196.Gorter, K., 114, 197.Gortner, R. A.. 142, 177.Gottlieb-Billroth. H.. 77Goudriaan, F., 41.Griinacher, C., 116.Grahmann, W., 212.Greaves, J. E., 136, 185. 186Green, S. J., 69.Greenfield, R. E., 150.Greenwood, (Niss) A . , 111.Greinacher, H., 248.Grignarcl, V.. 59.Gr6h, J., 227.Gross, C. V., 41.Gross, R., 198, 199.Grube, G., 50.Grube, H., 97.Gruber, G., 49.Grun, A., 53, 184.Guerbet, M., 139.Gutbier, A., 36.Guyot. J., 139.Haas, A. R. C., 180,Haber, F., 4, 5, 6, 8.Haehn, H., 169.Haehnel, W., 134.Wagga.rd, H. W., 164.Hahn, O., 243, 244.Haldane', J.B. S., 164.Hall, A. J., 195.Hall, N. F., 224.Haller, A., 87.Hnller, H. T,., 122.25254 INDEX OF AUTHORS’ NAMES.Hamer, (Miss) F. M., 122.Hanke, M. T., 173.Hansen, R., 181.Hansgirg, F., 94.Harden, A., 166.Harkins, W. D., 29, 33, 225, 226.Harries, C., 56, 80.Harrow, B., 195.Hartwell, B. L., 190.Harvey, E. M., 144.Haun, F., 144.Haworth, W. N., 65, 66.Hedvall, J. A., 40.Heidel berger, M., 95.Heider, K., 104.Heiduschka, A, 140, 141.Heinemann, 9., 53.Helfrich, 0. B., 59.HQmen, C., 148.Henderson, J. A. R., 140.Henderson, L. J., 161.Henderson, Y., 164.Hendrick, J., 187.Hendrixson, W. S., 145.Henley, I?. R., 54.Henrich, F., 239.Hermans, P. H., 144.Herzfeld, A., 56.Herzfeld, E., 169.Herzig, J., 157.Hess, A.F., 165.Hess, K., 61, 67, 107, 108, 109, 125,Hess, V. F., 233, 235, 237, 242, 249.Hevesy, G. von, 226, 227.Hewitt, J. A., 155.Heyrovskf, J., 41.Hibbard, P. L., 145.Hickinbottom, W. J., 54, 83.Hilditch, T. P., 65.Hildt, E., 141.Hilgendorff, G., 74.Hill, C. W., 132.Hill, L., 194.Hirai, K., 160.Hirst, C. T., 136.Hitchens, (Miss) A. F. R , 241.Hjalmar, E., 232.Hoagland, D. R., 180.Honigschmid, O., 36, 223.Hofbauer, C., 246.Hofmann, K., 44.Hofmeister, F., 160.Hollander, A. J. den. 73.Holleman, A. F., 73.Hollnagel, H. P., 200.Holluta, J., 146.Holm, G. E., 142, 177.Holmes, E. O., jun., 35.Holmes, M. E., 46.Hopfer, G., 80.Hopkins, F. G., 161, 165.Horton, F., 14 15, 18, 21.127, 195.Houben, J., 145.Howard, L.P., 178, 180.Hiickel, W., 71.Hiitter, C., 130.Hughes, J., 188.Hugounenq, L., 159.Hull, A. W., 204, 232,Hull, M., 173.Hume, E. M., 168.Hutchinson, H. B., 181.Inamura, K., 41.Ingold, C. K., 90.Irvine, J. C., 66.Jacobs, (Miss) L. M., 131.Jacobs, W. A., 95.Jacoby, &I., 169, 191.James, C., 147.James, R. W., 204.Janet, M., 171.Jansen, B. C. P., 166.Jantsch, G., 56.Joffe, J., lG3.Joffe, J. S., 179.Johns, C. O., 156, 19€.Johnson, A. G., 194Johnstone, J. H. L., 242.Jona, M., 23.Jones, C. H., 192.Jones, D. B., 156.Jones, G. W., 134.Jones, J. S., 195.Jose hson, K. O., 82.JuddJ, (M iss) H. M., 141.JoffB, C. I.., 75.Kagi, H., 63.Kailan, A., 239.Kallenberg, S., 116.Ramm, O., 59.Kammerer; H., 86, 93.Karpf, (Frl) L., 73.Karrer, P., 78, 85, 102, 112.Kashima, K., 84.Kauffmann, H., 75.Kaufmann.W. von, 169.Cearney, T. H., 187.Seen, B. A., 185.(ehrmann, F., 77.ielber, C., 52.CeIley, G. L., 150.Zendall, E. C., 173, 174.Z e n n a y . ? , E 72. L., 164.CennerZessler, E., 108.Gndler, K., 117, 118.+g, A. T., 54.Cing, H., 79, 157.King, J. S., 46INDEX OF AUTHORS’ NAMES. 265Kiplinger, C. C., 130, 131.Kirchhof, F., 47.Kirsch, G., 234, 242.Kirschbaum, G., 84.Klason, P., 195.Kleinmann, H., 148.Kling, A.. 146.Klinger, R., 169.Klopsteg, P. E., 149.Kliig, A., 53.Knecht, E., 140.Knight, H. G., 135, 136, 178.Knipping, P., 13, 21.Knowles, H. B., 146, 147.Kobayashi, M., 148.Koch, K., 176.Kodama, S., 59.Kogel, P.R., 192.Koessler, K. K., 173.Kohlrausch, I(. W. F., 236.Kohlweiler, E., 226.Koketsu, R., 185.Kolthoff. I. M , 133, 145. 146, 149, 15b.Koppel, J., 143.Korcz$nski, A., 77.KOSS, M., 242.Kossel, W., 228.Krause, E., 96.Krauskopf, F. C., 135.Kremers, H. C., 35.Krepelka, H., 35.Krogh, A . , 154.Kruger, T., 13.Kryz, F., 195.Kubota, S., 172.Kuhara, M., 84.Kunz, R., 137.Kurosawa, J., 196.Kuzirian, S. B.. 14 174.Lahille, A., 139.Lamb, A. B., 48, 132, 133.Landauer, R. S., 34, 37.Land& A., 2, 200, 201.Landsteiner, K., 157.Langlois, G., 80.Langmuir, I., 21, 228.Lapworth, A., 91, 105Larson, A. T., 133.Lassieur, A., 146.TAathrop, E C., 184.Laudat, M., 171.Lawson, R.W., 235, 236, 237, 240.Le Clerc, J. A . , 189.Ledig, P. G., 134.Lee, H. A.. 183.Lkver, E., 120.Lerde, A. B., 232.Lembert, M., 224.Lemoigne, M., 138.Lenart, G., 56.Lepape, A., 248.Lescoeur, L., 139.Lester, 0. C., 248.Leuchs, H., 158.LQvi, L,, 190.Levinstein, H., 76.Levinstein, Ltd., 76.Lewis, G. N., 228.Lewite. A., 169.Lifschitz, I., 75.Lind, S. C., 238, 239, 241.Lindemann. I?. A., 7. 8, 225, 226.Lindhard, K. G., i54.LiDman. J. G.. 187.Liip, P., 91. ’Livingstone, B. E., 185.Loeb, L. B , 219.Loebel. W.. 39.Logie, ,147. J., 160.Loisel, P., 248.Lorenz, R., 22, 209.Lowry, T. M., 55.Lucius, F., 141.Luckey, G. P., 132.Ludwig, H., 92.Lumihre, A., 167, 191.Lund, C. H., 122.Lundell, G. E. F., 146, 147.Lupton, H., 239.Luros, G.O., 167.Lutz, O., 144.Lyon, T. L., 180.Maass, O., 55.McCarrison, R., 167.M.cGleland, N., 183.McCollum, E. V., 142, 167.McCool, M. M., 187.McCoy, H. N., 247.McDavid, J. W., 131.Macdonald, A. D., 98.McHargue, J. G., 197.Macht, D. I., 172, 173.McIlvaine, T. C., 179.McKenzie, A., 61. .McLennan, J. C., 37, 134Macy, I. C., 138.Maggi, H., 169.Mailhe, A., 55, 68.Malowan, S. L., 143.hfanchot, W., 53, 96.Maquenne, L., 189, 190, 191.Marden, J. W., 45.Mar osches, R. M., 140.&Jarye, (hllle) T. W. J. van, 60.Martin, J. C., 187.Martin, W. H., 179.Marvel, C. S., 54, 59.Maschmann, E., 135.Mason, T. G., 141.Massey, A. R., 184.Mathewson, W. E., 132.Matsunka, Z., 158256 LNDES O FMattaar, T.J. F., 170.Matter, O., 92.Rlatthews, I). J . , 184.Maxted, E. B., 50.Mazuir, A., 14.3.Meerwein, H., 100.Meier, K., 162.Meindl, O., 146.Meisenheimer, J . , 84, 109.Meitner, L., 243.Melber, IT. W., 124.Meldrum, W. B., 132.Mellanby, J., 163.Nenaul, P., 141.Mendel, L. B., 165.Nerton, T. R., 224, 231.Merwin, H. E., 212, 214.bfestrezat, W., 142, 171.Meyer, E., 56.Meyer, J., 95.Mever. K. H.. 57, 75, 77, 94.Ifeier; R., 53.Meyer, S., 233, 240, 242.Michaelis, L., 162.Michel, M., 137.Mignonac, G.. 56.Mikeslta, 11. A., 122.Miles, F. D., 48.Millar. C. E., 187.Riilligin, r,. H., 47.Mills. W. H., 121, 122.Mirasol, J. J., 178.Mitchell, C. -4., 143.Mockeridge, F. 14., 168, 191.Mollney, E., 135.Mohler, F.L., 5, 14, 15, 16, 19.Moir, J., 138.Moissonnier, S., 171.Moles, E., 35.Moore, B., 193.Morgan, G. T., 56.Morris, R. L., 148.Moureu, C., 56, 133.Moyer, J.. 132.Mrozirirki, W., 77.?t!iiller, 147.Miiller, B., 140.Miiller , Erich. 149.Miiller, Ernst, 78.Mugdan, M., 134.Muller, J. A4., 134.Myers, C. N.. 166.Nacken, R., 209.Nagayama, T., 172.Neller, J . R., 181.Nelson, E. K., 85.Neuberg, C., 61, 170.Neumann, B., 53.Neumann, L., 73, 104.Neumeister, F. R., 134.Neuschlosz, S. M., 190.AT:THORS' NAMES.Newbery, E., 239.Nicloux, M., 164.Nierenstein, JI., 110, 111,Nierman, J. L., 246.Niggli, P., 198, 212.Norring, O., 228.Noll, H., 151.Nord, F. F., 61, 170.Nordlund, I., 36.Noyes, H. A . , 178, 188.Niirnberger, O., 248.Odkn, S., 176.Ogg, W.G . , 187.Ogilvie, J., 76.Ohlendorf, H., 68.OrBkhoff, A . , 84.Osborne, T. B., 165, 196.Osterberg, A. E., 173.Osterhout, W. J. V., 192.Owens, A. W., 35.Osley, A. E., 9, 19, 20.Ott, E., 134.Pal, G., 248.Palkin, S., 141, 146.Palmer, A. D., 157.Palmer, P. E., 133.Paneth, F., 46, 228, 233.Pannwitz, 137.Papaconstaiitinou, €3. C., 36.Parker, F. W., 190.Parkin, M., 72.Parsons, (Sir) C. A . , 42.Parsons, T. R., 161.Pascal, P., 132.Pmw, P. de, 142.Pelbois, E., 169.Pember, F. R., 190.Perkin, A. G., 94.Perkin, W. H., 105.Perrier, J., 143 ..Perrott, G. St. J., 135.Peters, R. A., 183.Pfeiffer, T., 190.Philip, J. C., 43.Pierre, C. L4., 147.Piutti, A., 29, 221.Planck, M., 201.Poole, J.H. J., 247.Pope, (Sir) W. J . , 58, 122.Porter, (Bliss) &I. W., 211.Poulton, E. P., 163.Powcll, s. G., 84.Power, F. B., 196.Pozzi-Escot, E. , 186.Prescott, J. 9., 184.Price, T. S., 69.Price, T. W., 131.Prinre, A. L . , 179INDEX OFPringsheim, H., 109.Prins, H. J., 30.Pryde, J., 155.Puchner, H., 177.Purdy, L. H. 135.Puxeddu, E., 82.Pyman, F. L., 115.Quartaroli, A., 148, 233.Rabe, P., 117, 118.Raber, 0. L., 190.Raistrick, H., 160.Ramstedt, E., 246.Rankin, G. A., 214.Raquet, I)., 138.Ravald, L. A, 115.RAY, J. N., 74, 78.Rebmann, A., 78.Reedy, J. €I., 150.Reid, E. E., 59.Reilly, J., 54, 83.Reinau, E., 191, 192.Reis, A., 6 , 199.Remy, H., 142.Rich, M. N., 45.Richards, T. W., 223, 224.Richardson, I!'.S., 174.Riedel, F., 192.Riedemann, A., 147.Ries, A., 211.Rindfusz, R. E., 102.Rinkes, I. J., 80.Rinne, F., 199.Rippel, A., 137, 190.Rivat, G., 59.Robbins, W. J., 184.Roberts, A. W. R,., 183.Roberts, H. E., 194.Roberts, L. D., 241.Robertson, P. W., 47.Robin, P., 133.Robinson, C. S., 137, 149.Robison, R., 166.Rodt, V., 151.Rollo, L., 42.Rose, H., 210.Rosenheim, O., 195.Rosenmund, K. W., 77.Rosenstein, L., 46.Rosenthaler, L., 197.Rossi, A., 137.Roth, K., 83.Bothenbach, M. , 244.Rothlin, E., 173.Rowe, F. M., 92.Royle, F. A., 91.Rubens, H., 199.Rup., H., 63.Russell, J., 55.Rutherford, (Sir) E., 33. 219, 220.REP.-VOL. XVII.AUTHORS' NAMES.Sabalitschka, T., 137.Saerens, E., 54.Salkowski, E., 139, 183.Sallingw, H., 169.Salter, R.M., 179.Sa~nelson, S., 167.Sameshima, J., 223.Samuelson, E., 58.Sando, C. E., 195.Santesson, C. G., 170.Sasaki, T., 160.Satterly, J., 248.Saw, M. P., 178.Schamberg, E., 81.Schames, L., 20.Scheiber, J., 80.Scheibler, H., 57.Schemer, P., 1, 233.Schlesinger, E., 124.Schlundt, H., 240.Schmidt, W., 93.Schmitz, M., 96.Schneides, H., 53.Schneider, W., 53.Schneiderhohn, H., 212.Schoeller, V., 57, 75.Scholl, C. E., 246.Schollenberger, C. J., 177.Schotte, H., 64.Schotz, S., 83.Schryver, S. B., 140.Schultze, A., 246.Schwarz, R., 45, 147.Scott, W.. 150.Sebelien, J., 188.Seeliger, R., 217.Sen, H., 142.Sen, K. B.. 85.Sen, N. N., 17.Sertz, H., 130.Shakespear, G.*4., 133.Shapovalov, M., 194.Shedd, 0. M., 136, 184.Shive, J. W., 189Short, W. H., 79Sidgwick, N. V., 71.Siegbahn, M., 232.Simmermacher, W., 190.Simon, L. J., 139.Simonsen, J. L. 86.Skinner, W. W., 148.Skita, A., 87.Skrabal, A., 59.Skraup, S., 99.Slater, W. K., 78.Slator, A., 140.Smith, C. N., 39.Smith, G. McP., 140.Smith, L., 58.Smith, M. S., 147.Smith, 0. M , 186.Smith, T. B., 134.Smithey, I. W., 46.K25258 INDEXSmyth, I€. D., 16, 17.Soddy, F., 241, 245.Somieski, K., 44.Sommerfeld, A., 198, 202.Sonn, A., 78.Soutar, C. W., 66.Souza, G. de P., 142, 167.Spek, J., 191.Spencer, L. J., 200.Staehling, C., 244.Starkweather, H. W., 35.Staudinger, H., 82, 83, 95, 97.Steele, (Miss) E.S., 66.Steenbock, H., 163.Steiger, A. L. von, 71.Stenstrom, W., 232.Stephen, H., 78, 79.Stephenson, R. E., 178.StBrba-Bohm, J., 41, 147.Stern, K., 192.Stern, L., 173.Etern, O., 200.Stevenson, H. C., 142, 167.Stewart, J. K., 12%.Still, G. F., 165.Stock. A., 44.Stockholm, M., 167.Strafford, N., 140.Straub, H., 162.Strecker, W., 147.Strowd, W. H., 181.Struck, E., 77.Sumikura, K., 139.Sumner, J. B., 196.Suter, E., 82.Sredberg, T., 36.Tadokoro, T., 190.Taeger, K., 53.Tanaka, M., 166.Tanret, G . , 109.Tattersfield, F., 183.Taube, E. L., 150.Tauber, F. A., 134.Thaysen, ,4. C., 54.Thirring, H., 199.Thomas, C. J., 163.Thomas, M. D., 56.Thomas, P., 155, 159.Thompson, L., 140.Thorne, C. E., 187.Thorpe, J.F., 87, 89.Thuillier, H. F., 58.Tiffeneau, M., 84.Toivonen, N. J., 90.Tommasi, G., 85.Traube, W.. 68.Trautz, M., 46.Treadwell, W. D., 134, 149.Truffaut, G.. 183.Tmog, E., 180, 190.Tsudji, M., 160.OF AUTHORS' NAMES.Tubandt, C., 208.Tunstall, N., 204.Tutt,on, A. E. H., 210.Uhl, E., 80.Ullmann, F., 93.Underwood, J. E., 240.Urbain, E., 59.Valkenburgh, H. B. van, 144.Vanderberghe, H., 140.Vanderstichele, (Miss) P. L., 59.Venable, F. P., 46.Vesterberg, I(. A., 38.Vielau, W., 77.Vigneron, H., 130.Vischniac, C., 196.Voegtlin, C., 166.Vogel, E., 140.Voigt, W., 200.Voss, J., 57.Vostr'ebal, J., 147.Wakeman, A. J., 165, 196.Warburg, O., 192.Wardlaw, W., 48.Wartenberg, H. von, 199.Warth, F. J., 178.Waterman, H. C., 196.Watson, H. E., 248.Weatherill, P. F., 35.Weaver, E. R., 133, 134.Webster, T. &4., 193.Weick, R., 74.Weinberg, A. von, 69.Weis, F., 190.Weise, Q. L., 36.Weiss, J. M., 80, 184.Weiss, L., 149.Weiss, R., 74.Weiemann, C., 54.Weltzien, W., 61, 108, 109.Wendt, G. L., 34, 37.Wenger, P., 148.Werner, E. A., 68.Wertheimer, R., 160.Wester, D. H., 136.Wherry, E. T., 136, 178.White, A. G., 131.White, W. P., 132, 209.Whiting, A. I,., 181.Wickel, F. C., 39.Widmer, F., 85, 102, 112.Wieland, H., 81, 83, 99.Willaman, J. J., 167.Williams, R. J., 142, 167.Willstatter;R., 112, 127, 135, 199.Wilson, B. D., 180.Windisch, W., 131.Winkle, W. A. van, 140.Winter, Q. B., 149INDEX OF AUTHORS' NAMES.Winter, R. M., 43.Wise, L. E., 122.Wishart, R. S., 121.Wittelsbach, W., 67, 195.Woker, G., 169, 192.Wolff, H. T., 234.Wolff, L., 140, 141.Wolff, M., 68.Wolkoff, M. I., 185.Wood, C. C., 140.Workman, (Miss) O., 43.Worsley, R. R. Le G., 47.Wourtzel, E., 237.Wren, H., 61.Wright, F. E., 212.Wright, R. C., la.Wurmser, R., 192.Wyckoff, R. W. G., 39, 205, 206.Wyczatkowska, W., 104.Yablick, M., 135.Yamasaki, E., 170.Zander, H., 68.Zechmeister, L., 112, 227.Zeller, E., 78.Zenghelis, C., 36.'Zimmermann, F., 135.Zinke, A., 94.Zlatorovic, R., 249.Zwaardemaker , H., 190.Zweigbergk, N. von, 40.25

ISSN:0365-6217    

DOI:10.1039/AR9201700251

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

INDEX OF SUBJECTSAcetaldehyde, preparation of, fromacetylene, 53.Amtic acid, 5yeparation of, fromacetylene,Acetoacetic acid, detection of, 137.ethyl ester, 57.Acetyl acetonates, 56.Acetylene, condensation of, 53.estimation of, 134.Acids, aliphatic, and their derivatives,56.organic, fatty, preparation of, fromhydrocarbons, 52.identification of, 133.Actinium, parent of, 243.life-period of, 243.Actinium-uranium ratio, 242.Addition theoiy of reactions, 96.Agricultural analysis, 135.Alcohols and their derivatives, 54.-4ldehydes. 56.A 1;crc’ic group. 87.Alizarinsulphonic acid, sodium salt, asan indicator, 142.Alkaloids in plants, 196.chelidonium, 122.pyrrolidine, 125.estimation of, 141, 150.catalytic reduction of, 54.,41kyl bromides, p.reparation of, 59.Ally1 alcohol, estimation of, 149.Aluminates, 41.Aluminium nitrate, 41.Amines, aliphatic.68.-4mino-acids, 155.aromatic. reduction of. 87.action of bacteria on 160.esters, preparation of, 157.estimation of, 150.estimation of, in soil, 184.electrochemical, 148.inorganic, 142.mi crochem i pal, 144.organic. 137.phvsical. 130.wnter. 150.Ammonia. detection of. 143.Analysis, agricultural. 135.gas, IF-Snemonin, 113.Anthocyaains, 112.in plants, 195.Anthracene group, 93.Antimony, crystal structure o 204.sulphide, golden, 47.Apples, odorous constituents of, 196.Argon, structure of, 32.ionisation of, 18.Aromatic groups, polycyclic, 92.Arsenic trichloride, preparation of, 47.trioxide, volumetric reductionmethod with, 145.detection of, 47, 143.estimation of, 145, 149.separation of, 147.Aspidinol, 85.Atmosphere, radioactivitv of the, 249.Atoms, structure of, 2, 228.nuclear constitution of, 217.elementary. volumes of, 202.heavy, impact of a-particles on, 217.light, impact of a-particles on, 218.Atomic distances, 201.model, Bohr’s, 19.theory, 28.volumes, 201.weights, 35.Azides, metallic, 46.Azo-compounds, 75.Barium pwoxide, reactions of, 40.Benzalizarin, 94.Renzanthrone derivatives, 94.Benzene derivatives, position-isomeric,boiling points of, 71.nucleus, meta-ring system in the, 73.reactivity of substituents in the,72.Renzidine, colour reactions with, 142.Benzoic acid, detection of, 138.Renzosazole, reactions of, 99.Bismuth, atomic weight of, 36.Blood, alkalinity of, 164.Boron orgmic compounds, 95.oxid,es.47.gases of the, 160.hydrogen-ion concentration of, 164.26INDEX OF SUBJECTS. 261Brass, radioactivity of, 247.Bromine, estimation of, 148.dicyclo- and tricycZoButane derivatives,n-Butyl alcohol. use of, in syntheticalconversion of, into methyl ethyl88.reactipns, 54.ketone, 54.Czsium dichloroiodide, crystal struc-Calcite group, crystal structure of,Calcium in plants, 190.orthoarsenates, 39.carbide. action of bromine on. 39.estimation of, 136.Capsaicin, 85.Carbamide. See Urea.Carbohydrates, 64.metabolism of, 154.Carbon compounds, energy of atomiclinkings in, 69.monoxide, absorption of, 135.removal of, in gas analysis, 44.estimation of, in blood, 164.dioxide, assimilation of, in plants,in blood, 161.estimation of, in organic com-estimation of, 139.See also Charcoal and Diamond.ture of, 206.205.191.pounds, 139.140.Carbonates, estimation of, 136.Carminic acid, 85.Catalase, 170.Catechin. constitution of, 110.Cations of the third and fourth groupb,Cellulose, conversion of, into glucose,Cerium, detJection of, 143.Charcoal. absorptive power of, 43.Chelidonium alkaloids, 122.Chlorine, structure of, 32.Chlorogenic acid. 85.Cinchonhe and its derivatives, 119.Cinnamic acids. 74.optically active, 62.Cobalt,. detection of, 143.Codeine, 124.estimation of, 142.Colloids, inorganic, 36.Colour, rellation of, to constitution, 75.Compounds. unsaturated, 81.qdoniine.108.Copner salts, action of, on vegetation,Coumaranones. reactions of, 100.C~*ops, composition of, 194.separation of, 142.67.in plants, 195.190.estimation of Iead in, 132.alloCryptopine, 123.Crystal lattice, energetics of the, 1, .9.Crystals, electrolytic conduction in,ultramicroscopic inclusions in, 208.dehydration process in, 214.Crystallography, comparative chemical.physical, ZQ8.Cupferron, use of, in analysis, 146.Cuskhygrine, 125.isocyanines, 121.Cyanogeii chloride, preparation of, 69.Hydrocyanic acid, synthesis of, 68.Cyclic compounds, stability and forma-structures, formation of, 97, 104.208.210.in plants, 197.detection of, 138.tion of, 102.Dextrose, detection of, 138.Diamond, artificial production of, 42.Diazo-compounds, estimation of, 140.Diethyl sulphide, W-dichloro-, pre-Diphenylamine reagent, preparation ofDiphenylnitric oxide, reactions of, 83.estimation of, 141.parstion of, 58.estimation of, 135.the, 144.r-Ecgonine, ethyl ester, 127.Efflorescence, 214.Electrochemical analysis, 148.Elements.spectra of the, 31, 232.Elsholtzione, 114.Ethers, catalytic preparation of, 55.Ethyl alcohol. production of, fromEthylene glycol, estimation of, 140.Ethyl ether, oxoniuni compound of, 55.acetaldehyde, 54.estimation of, 150.Fats, natural. synthesis of, 58.Ferments, 168.Ferrous salts, oxidation of, by sulphurdioxide, 48.Fertilisers, 187.Flavones in plants, 195.Fluorine, atomic weight of, 35.Food substances, accessory, 164.Forma71dehpde, condensations with, 7%.oxidation of methyl alcohol to, 5b.diastase-like properties of, 168.colour reactions with, 137.Friedel-Crafts’ reaction, 78.Gas analysis, 133.Gases, ionisation in, 13.resonance potentials in, 13.rare, 37262 INDEX OF SUBJECTS.Geiger-Nuttall relation, 233.Glucal, constitution of, 64.Gluconic acid.preparation of, 56.y-Glutamic acid, B-hydroxy-, synthesisof, 155.Glycine, unstable variety of, 157.Glyoxalines, 115.Guaiacol, detection of, 139.Guanidine, prepasation of, 68.Halogen atoms, neutral, affinity of, forcompounds, aliphatic, 58.Halogens, estimation of. 139, 150.Halogenation, 76.Helium, production of, 37.electrons, 4.structure of, 32.atom, structure of the, 19.estimation of, 134.Histamine, 172.Hofmann reaction, 80.Homocamphor. preparation of, 91.Hormones, 172.Humic acid, estimation of, in soil, 177.Humin, 177.Humus, 175.Hydrindene group, 92.Hydrocarbons, 52.Hydrocyanic acid.See under Cyan-Hydrogen, st>ructure of, 32.triatomic, 37.ionisation of, 13.sulphide, influence of, on the occlu-sion of hydrogen by palladium, 50.estimation of, 133.Hydrogen-ion concentration, deter-mination of, in blood, 164.Hydroxylamine, preparation of deriv-atives of. 68.Hyptolide, 114.heat of combustion of, 69.ogen.Ignition-temperatures, determinationIndazole, derivatives of, 108.Inorqanic analysis, 142.Iniilin, 66.Iodine, ionisation of, 17.of, 131.action of potassium chlorate on, 49.pentoxide, preparation of, 48.Periodides, aliphatic, 59.Iodic acid as a reagent, 143, 144.Iodometrg, 145.Tonisation in gases, 13.Tonium, life-period of, 245.Tons, heat of hydration of, 3, 4.Iron, estimation of, 150.Tsotopes, 221.electrolytic, mobilitv of, 22.separation and properties of, 225.Ketones, 56.Krypton, structure of, 33.unsymmetrical, phytochemical reduc-tion of, 61.Lawsone, 85.Lead, isotopes of, 223.of radioactive origin, atomic weightof, 223.melting point and spectra of, 224.hydride, 46.tri-p-Zxylyl, 96.LiBnine, 173.Lignin in plants, 195.Liquids, estimation of acidity of? 131.Lithium metasiljcate, 38.organic, identification of, 131.Magnesium, detection of, 144.separation of, 146.Manganese, estimation of, 136.Mercury, structure of, 33.organic compounds, 96.estimation of, 146.Mesothorium, enrichment of, 245.Metals, structure of, 7.colloidal, 36.Methyl alcohol, detection of, 137.estimation of, 140.Microchemical analysis, 144.Mineral systems, thermal studies of,Minerals, specific heats of, 209.Molecular magnetic fields, 9.Molybdenum, detection of, 143.212.rearrangement, 83.estimation of, 147, 150.Naphthalene, nitro-derivatives, analy-Naphthalene group.92.Neon, structure of, 32.Nephelometer, new, 132.Nickel, estimation of. 146, 150.Nitrates, detection of, 144.Nitration, 76.Nitric esters, decomposition of, 55.Nitriles, preparation of, 68.Nitrites, detection of, 144, 151.Nitro-compounds, estimation of, 140.Nitrogen, structure of, 32.sis of, 132.ionisation of, 17.ionisation of, 16.quadrivalent, a radicle containing,assimilation of, in plants, 192.compounds of metals, 46.estimation of, 140.Nitrosyl bromides, 46.106.organic, stereoisomerism of.106.aIiphatic, 68INDEX OFOcean, radioactivity of the, 248.Opaque substances, methods of investi-gating, 211.Optical activity, 59,Organic analysis, 137.Oridine, 166.Osmium tetroxide, detection of, 143.Oxalic acid, detection of, 158.Oxidation, 80.Oxygen, ionisation of, 16.estimation of, 134.Palladium, occlusion of hydrogen by,50.a-Particles, impact of, on atoms, 217,218.Peat, 176.isoPelletierine, reactions of, 107.Pentosans, estimation of, 141.Peroxydasic function in plants, 197.Perylene, preparation of, 94.Phenol, estimation of, 141.Phenolphthalein, estimation of, 141.Phenyl-lactic acids, hydrolysis of estersof, 61.Phenylpyruvic acid, ethyl ester, enolicand ketonic forms of, 74.Phosphates, detection of, 144.Phosphoric acid, estimation of, 148.Phosphorus, red, reducing action of,46.in soil, 177.as a standard in alkalimetry, 144.organic compounds, 95.Phthalic acid, potassium hydrogen salt,Physical analysis, 130.crystallography, 208.Phytin, estimation of, 137.Pinacyanol, constitution of, 122.Plant growth, 188.effect of light and temperature on,relation of soils to, 185.water supply in relation to, 185.193.products, 113.Plants, alkaloids in, 196.assimilation in, 191.constituents of, 195.pTgments in, 195.proteins in, 196.function of, in plant nutrition, 190.chlorate, action of iodine on, 49.as a standard in alkalimetry, 144.manganifluoride, preparation of, 49.platinichloride, hydrolysis of solu-tions of, 51.detection of, 144.estimation of, 14%.Potassium, preparation of, 39.Proline, hydroxy-, stereoisomerides of,Proteins, 155.158.SUBJECTS. 263Protoanemonin, 114.Pyrrolidine alkaloids, 125.Quinine, detection of, 139.Quinoline compounds, 116.dyes, 121.1Zadioactive minerals, studies of, 239.Radioactivity, natural, 247.of rocks, 247.of rubidium, 244.of uranium oxides, 244.of water, 248.Radium, enrichment of, 245.and uranium, relative a-activities of,emanation, solubility of, 246.rays, chemical action of, 237.241.Radium-uranium ratio, 241.a-Rays, 233.y-Rays, 236.Resonance potentials in gases, 13.Rhodanines, 116.Rocks, radioactivity of, 247.Rubidium, radioactivity of, 244.Samarium, atomic weight of, 35.Salts, electrical conductivity of, 24.heat of solution of, 3.double, examination of, 132.Scandium, atomic weight of, 35.fluorides, 42.Scopoline, 127.Selenium acetylacetonate, 56.Silicon, atomic weight of, 35.function of, in plant nutrition, 190.compounds, inorganic, 44.Sodium chloride, electrical conductivityof, 26.f errate, preparation of, 49.sulphates, action of alcohol on, 38.zincate, 41.acidity of, 1177.alkali, 186.esti-mation of ammonia in, 184.organic matter in, 180.organisms of, 181.oxidation of sulphur in, 184.relation of, to plant growth, 185.analysis of, 135.Sols, metallic, DreDaration of.36.Soil, 175.Spectra, high-freiuency, 232.mass, 31.St,ereoisomerism of nitrogen com-Strontium sulphide, action of water on,Strychnine, detection of, 139.pounds, 106.40.estimation of, 141264 INDEX OF SUBJECTS.Sucrose, constitution of, 65.estimation of, 141.Sugars in plants, 196.estimation of, 141.Sulphates, estimation of, 145.Sulphonation, 76.Sulphur, oxidation of, in soiI, 184.dzoxide, solubility of, in sulphuricoxidation of ferrous salts by, 48.acid, 48.Synthesis, asymmetric, 74.Systems, mineral, thermal studies o f ,symmetric and asymmetric, 109.212.Taste of organic compounds, 59.Tellurium acetylacetonate , 56.Terpene, new bicyclic, 86.Thallium nitrate-nitrites, 42.Thorium-D, y-activity of, '246.Thorium minerals, age of, 239.Thyroxine, 173.Tin, atomic weight of, 35.hydride, 46.organic derivatives, 96.detection of, 143.estimation of, 145.p-Toluenedisulphochloroamide, sodiumsalt, colour reactions with, 137.Tricyclene, preparation of, 91.Tryptophan, metabolism of, 158.Tyrosinase, 169.Uranium and radium, relative a-activi-estimation of, 159.ties of, 241.oxides, radioactivity of, 244.estimation of, 147.Uranium-actinium ratio, 242.Uranium-radium ratio, 241.Uranium-X-uranium-Y ratio, 242.Urea, estimation and forma.tion of,Urease, 169, 170.171.Vanillin in soil, 184.Vinyl ethyl et.her, &-dichloro-,Viscosimeters, new, 130.Vitamins, 164.estimation of, 142.Volumes, atomic, 201,preparation of, 59.Water, radioactivity of, 248.Weights, atomic, 35.analysis, 150.Zinc phosphates, 41.Zincite, crystal structure of, 205.Zirconium and its compounds, 45.estimation of, 147

ISSN:0365-6217    

DOI:10.1039/AR9201700260

出版商:RSC    

年代:1920

数据来源: RSC