摘要:

ANNUAL REPORTSON TEEPROGRESS OF CHEMISTRYANNUAL REPORTSH. B. BAKEIL, C.B.E., D.Sc., F.R.S.E. C. C. BALY, C.B.E., F.R.S.H. BASSETT, D.Sc., Ph.D.0. L. BKAIJY, D.Sc.A. W. CROYBLEY, C.M.G., D.8c.,H. W. DUDLEY, O.B.E., RLSc., P11.D.U. R. EVAXS, M.A.J. J . Fox, O.B.E., D.Sc.C. S. GIBSON, O.B.E., M.A.I. M. HEII~BKON, D.S.O., I).Sc.T. A. HENRY, D.Sc.F.R.S.W. N. HAWORTH, D.Sc., P11.D.ON THET. M. LOWKY, C . H . E . , D.Sc., F.R.S.J. W. MCBAIN, Ph.L)., F. 1l.S.H. MCCOMBIE, D.S.O., M.C., D.Sc.J. I. 0. bEAssox, M.B.E., D.Sc.W. H. M i L r s , Sc.D., F.R.S.G. T. MORGAS, O.B.E., D.Sc., F.R.S.J. C. PHILIP, O.B. E., D.Sc., F.R.Y.R. H. PICKARD, D.Sc., F.R.S.T. S. PRICE, O.B.E., D.Sc., F.R.S.J. P. THORPE, C.B E., D.Sc., F. R.S.W. P. WYNXE, D.Sc., F.R.S.T.s. 1(100RE, nf.A., 13.sc.F. L. PYMAS, D . ~ c . , F. K.S.PROGRESS OF CHEMISTRYW, T. ASTBURY.F. W. ASTON, M.A., D.Pc., F.R.S.Sir W. H. RRAW, K.B.E., F.1i.S.H. V. A. BKISCOE, D.Sc.W. CLAYTUN, D.ScH. M. DAWSON, D.Sc., Ph.D.F O R 1924.ISSUED BY THE CHEMICAL SOCIETY,J . C. DRI-MMOSD, D.Sc.IT, N. IIAWOKTII, D.Sc., P1i.D:T A. HENEY, D.8c.C. K. INGOLD, D.Sc., F.R.S.C. AINSW’OKTII M rrcI1ELL, M. A .11. 5. PAGE, M.B.X., B.Sc.&rbrxtx :MARGARET LE PLA, B.Sc.V O l . XXI.LONDON :GURNEY & J A C K S O N , 33 PATERNOSTER ROW, E.C.4.1925PRINTED IN GREAT BRITAIN BYRICHARD CLAY & SONS, LIM~TBU,BUNQAY, BUFFOLKCONTENTS.rAGEGENERAL AND PHYSICAL CHEMISTRY. Ry H. 11. DAWSON, D.Sc.,Ph.D. . . . . .. . . . . .INORGANIC CHEMISTRY. By H. V. A. BRIECOE, D.Sc. . . . 27ORGANIC CHEXISTRY :-Part ~.-ALIPHATIC DIVISION. By W. N. HAwomH, D.Sc., P1i.D. . 55Pait II.-HOMOCYCLIC DIVISION. By C. K. INGOLD, D.Sc., F.R.S. . 92Part III.-HETERocYCLIC DIVISION. By T. A. HESRY, D.Sc. . . 122ANALYTICAL CHEMISTRY. By C. AIKSWORTH MITCHELL, M.A. . 151BIOCHEMISTRY. By J. C. DRUMMOND, D.Sc., and H. J. PAGE, M.B.E.,B.Sc. . . . . . . . . . . . . 171CRYSTALLOGRAPHY. By W. T. ASTBURY and Sir W. H. RRAGG, K.E.E.,F.R.S. . . . . . . . . . . . 220SUB- ATOMIC PHENOMENA AND RADIOACTIVITY. Ry F. W.ASTON, M.A., D.Sc., F.R.S. . . . . . . . . 233COLLOID CHEMISTRY. By WILLIAM CLAYTON, D.Sc. . . . 25TABLE OF ABBREVIATIONS EMPLOYED IN THEABBREVIATED TITLE.A . . . .Amer.J. Bot. ,Amer. J, HygieneAmer. J. Phcwm.Amer. J. Physiol.Amer. J. Sci. .Anal. Fis. Quim.Analyst . .Annalen . .Ann. Appl. Biol.Awn. Bot. . .Ann. Chim. .Ann. Chim. anal.Ann. Chim. Appl.Ann. Chim. I’hys.Ann. Physik .Ann. Physique .Ann. Report .Arch. eip. Path. Pharm.Arch. Farm. sperim. .Arch. Nkerland. physiol.Arch. Phnnn. . .Arch. Sci.phps. nut. .Arkiv Kern. nlin. Geol.Atti R. Accad. Lincei .Ber. . . . ,Ber. Deut. bot. Ges. .Bcr. Siichs. Akad. Wiss.Biochem. J. . .Biochcm. Z. . .Brmicstof-Chem. .Brit. Med. J. . .3uZ. SOC. Chim. fiincinizlBull. Acud. roy. Belg.Bull. SOC. chim .Bull. Soc. chim. Belg.Bull. Soc. Chim. biol.REFERENCES.JOURNAL.Abstracts in Journal of the Chemical Society, orAmerican Journal of Botany.American Journal of Hygiene.American Journal of Pharmacy.American Journal of Physiology.American Journal of Science.Anales de la Sociedad Espanala Fisica y Quimica.The Analyst.Justus Liebig’s Annalen der Chemie.Annals of Applied Biology.Annals of Botany.Annales de Chimie.Aniirtlrs de Chirnie analytique appliqude h 1’IndustriesAnnali di Chimica Applicatn.Annales de Chimie et de Physique.Annalen der Physik.Annales de Physique.Annual Reports of the Chemical Society.Archiv fur experinientelle Patliologie und Pharma-kologie.Archivio di Farmacologia sperimentale e Scienze affini.Archives Nderlandaises de physiologie dc l’homme e tdes aniniaux.Archiv der Pharniazie.Archives des Sciences physiques et naturelles.hrkiv for Kemi, Mineralogi och Geologi.Atti della Reale Accademia Nazionale dei Lincei.Rerichte der Deutschen Chemischen Gesellschaft.Eerichte dcr Deutschen botmischen Gesellschaft.Berichte uber die Verhandlungen der SiichsischenThe Biochemical Journal.Biocheniische Zeitschrift.Brennstoff Chemie.British Medical Journal.RulQtiniil Societjtei de Chimie din Romfnia.Academie royale de Belgique-Bulletin de la ClasseBulletin de la Sociht6 chiwique de France.Bulletin de la Sociktd chiwique de Belgiquc.Bulletin de la Soci6t6 de Chimie biologique.Chemistry and Industry.issued by the Bureau of Chemical Abstracts.*B l’dgriculture, h la Pharniacie et B la Riologie.Akademie der Wissenschaften zu Leipzig.des Sciences.The year is not inserted in references t o 1924viii TABLE OF ABBREVlATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.Chem.Listy . . .Chem. News . , .Chem. Umschau. . .Chem. Weckblad . .Chem. Ztg. . . .Chem. Zentr. . , .C'ompt. rend. . . .Compt. rend. Xoc. Biol. .Gazzetta . . I ,Geol. Ma3.. . . .Eelv. Chim. Actn . .J . . . .Jahrb. Radionktiv. .&ctro:Japan. J. Chem. . .J. Agric. Res. . . .J. Agric. Sci. . . .J. Anter. Chem. Xoc. . .J. Arner. Phnrm. Assoc. .J. Assoc. Of. Agric. Chem.J. Biol. Chein. . . .J. Chem. Iw,d. Japan . .J. Chem. Xoc. Japan . .J. Chint. phys. . . .J. Exper. Med. . . .J. Franklin Inst. . ,J. Gen. Physiol. . . .J. Ind. Eng. Chem. . ,J . Path. Bact. . . .J. Pharm. Chim. . .J. Pharm.Soc. Japan. .J. Physical Chem. . .J. Physiol. . . .J. Phys. Radium . .J. pr. Chem. . . .J. RZLSS. Phys. Chent. SOC. .J . SOC. Chcsn. Ind. . .Ko71. Chem. Beiheflc . .Kotloid 2. . . . ILandw. Versuchs-Stat. .M e m . Coll. Sci. Kyoto, .Mem. dlanchester Phil. Xoe.nikMtfm. Poudres . . .Monatsh. . . . .Munch. nzed. 7Voch. . .Nach. Ges. Wiss. Gottingen .Naturwiss . . . .Oestcrr. Chem. -2s. . .P . . * . . .Pgpierfabr. . . .JOURNAL.Chemickd Listy pro V:du a Prdniysl. Organ de la" CeskB ,,chemickn Spole6nost pro Vedn aPrihysl.Chemical News.Chemische Umscliau auf dem Gebiete der Fette, Oele,Wachse, und Harze.Chemisch Weekblad.Chemiker Zeitung.Chemisches Zentralblatt.Comptes rendus hebdomadaires des SEances del'Acad6mie des Sciences.Comptes rendus liebdomadaires de S h c e s de laSociBt6 de Biologie.Gazzetta chimica italiana.Geological Magazine.IFelvetica Chimica Acta.Journal of the Chemical Society.Jahrbuch der Radioaktivitat und Elektronik,Japanese Journal of Chemistry.Journal of Agricultural Research.Journal of Agricultnral Science.Journal of the American Chemical Society.Journal of the American Pharmaceutical Association.Journal of the Association of Official AgriculturalJournal of Rioloaical Chemistry.Journal of Che&al Industry, Japan.Journal of the Chemical Society of Japan.Journal de Chimie physique.Journal of Experimental Medicine.Journal of the Franklin Institute.Journal of General Physiology.Journal of Iiidiistrial and Engineering Chemistry.Journal of Pathology and Bacteriology.Journal de Pharmacie e t de Chimie.Journal of the Pharmaceutical Society of Japan.Journal of Physical Chemistry.Journal of' Physiology.Journal de Physique e t Ic Radium.Journal fur praktische Chemie.Journal of the Physical and Chemical Society ofJournal of the Society of Chemical Industry.Kolloidchemische Beihufte.Kolloid Zeitschrift.Die Landwirtschaftlichen Versuchs-Stationen.Memoirs of the College of Science, Kyoto ImperialMemoirs and Proceedings of the Manchester LiteraryMQmorial des Poudres.Monatshefte fiir Chemie und verwandte Theile andererMiinchener medizinische Wochensclirift.Nachrichten von der Gesellschaf t der WissenschaftenDie Naturwissenschaften.Oesterreichische Cliemiker-Zeitnng.Proceedings of the Chemical Society.Pavier-Fabrikant.Chemists.Russia.University.and Philosophical Society.Wissenschaften.zu GottingenTABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ixABBREVIATED TITLE.P$iigcr’s Archiv. . .Pharm. Weekblud . .Phil. Mag. . . .Phil. Trans. . . .Physical Rev. . . .Physikal. 2. . . .Proc. Camb. Phil. SOC. .Proc. K. Akad. Wefensch.Proc. Nat. Acad. Sci. . .Proc. Physical Soc. . .Proc. Roy. SOC. . . .Proc. SOC. Exp. Bwl. Ucd. .Quart. J. Exp. Physiol. .Hec. trav. chim. . . .AmsterdamRend. Accad. Sci. Fis. Hat.Napoli . . . .Rev, gdn. Bot. . . .Ilev. gdn. CoZl. . . .Sci. Rep. Tohoku imp. Univ.Sitzungsber. Akad. 1Vi.s~.Soil Sci. . * . .Trans.Amer. Eliclrochem.Soc. . . * .Trans. Faraday SOC. . .2. anal. Chem. . , .2. angew. Chem.. . .2. anorg. Chem. . . .2. deut. Oel-Fett. lnci?. .Z. Elektrochem. . . .Z. ges. exp. Ned. . .2. Nahr.-Ganussm. . .WienZ. Physik . . . .Z. physikal. Chesz. . .Z, physwl. Chem. . .JOURNAL.Archiv fur die gesamte l’hysiologie des Menschen undPharmaceutisch Weekblad.Philosophical Magazine (The London, Edinburgh andDublin).Philosophical Transactions of the Royal Society ofLondon.Physical Review.Physikalische Zeitschrift.Proceedings of the Cambridge Philosophical Society.Koninklijke Akademie van Wetenschappen te Amster-dam. Proceedings (English version).Proceedings of the National Academy of Sciences.Proceedings of the Physical Society of London.Proceedings of the Royal Society.Proceedings of the Society of Experimental BiologyQnarterly Journal of Experimental Physiology.Recueil des travaux chimiques des Pays-Bas et de laBelgique.Rendiconto dell’ Academia delle Scienze Fisiclie eMatematiche Napoli.Revue gkn6rale de Botanique.Revue gh6rale des Colloides.Science Reports, Tohoku Imperial University.Sitzungsberichte der Akademie der WissenschaftenSoil Science.Transactions of the American ElectrochemicalSociety.Transactions of the Faraday Society.Zeitschrift fur analytische Chemie.Zeitschrift fur angewandte Chemie.Zeitschrift fur anorganische und allgemeine Chemie.Zeitschrift der deutschen Oel- und Fett-Industrie.Zeitschrift fiir Elektrochemie.Zeitschrift fur die gesamte experimentelle Medizin.Zeitschrift fur Untersuchung der Nahrungs- .undGenussniittel.Zeitschrift fiir Physik.Zeitschrift fur physikalische Chemie, StochiometrieKoppe-Seyler’s Zeitschrift fur physiologische Chemie.der Thiere.and Medicine.Wien.und Verwandtschaftslehre

ISSN:0365-6217    

DOI:10.1039/AR92421FP001

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.THE bulk of experimental work published continues to increaseand so much is of interest that it has proved unusually difficultto make a fair and representative selection of papers for mentionin this Report. While steady progress is made in applying andtesting the electronic theories of vnlency, papers devoted solelyto their discussion are few and do not call for special inention.Further work and controversy on the subject of the reflection ofcharacteristic X-rays by the atoms in a crystal, which is likely tobecome of the greatest importaiice in determining the detailedstructure of inorganic will be discussed in the Report,on Crystallography .A toinic Weiyhls.Carbon.-Pure silver cyanide was heated a t 270" in pure hydrogenin glass or silica flasks and thus reduced to metallic silver : in anotherseries of determinations pure silver cyanate was similarly reduced.Assuming Ag = 107.88 and N = 14.008, twenty-one determinationsof the ratio AgCN : Ag give C = 12.002 0.001 and sixteen deter-minations of the ratio AgCNO : Ag give C = 12.003 &- 0.001.Bycombining these ratios, values for cyanogeii (CN = 26.008) and silver(Ag = 107.871) may be deduced relative to 0=16 without assump-tion : if this value for cyaiiogen is accepted and the well-establishedvalue N = 14.008 assumed, the atomic weight of carbon isC = 12.000.2 The value now obtained for silver, identical withthat deduced from the ratios LiClO, : LiCl and LiCl : Ag,, affordsstrong evidence that the accepted value Ag = 107.88 is certainlytoo high by about O - O l ~ , .Nitrogen.-Redeterminations of the density of pure nitrogen,prepared by the ignition of sodium azide, give the mean valueN = 14.008.4Sodium.-Eight determinations by conversion of sodium azideinto sodium nitrate give for the ratio NaNO, : NaN, values rangingfrom 1.30731 to 1.30738, whence, assuming N = 14.008, N a =22.998 & 0.002.5 Ten concordant determinations, giving in meanAnn.Report, 1923, 20, 29, 254.T. W. Richards and H. H. Willard, J . Amer. Chem. SOE., 1910, 32, 24.Idem, 2. physihd. Chem., 1923, 107, 423; A , , ii, 174,a G. Dean, J., 1924, 125, 2656.' E. Moles and J. M. Clavera, J . Chim. Phys., 1924, 21, 10; A . , ii, 45228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the value 1.45422&0.0000077 for the ratio NaN03 : NaCl, consideredin conjunction with the values of Richards and Wells for the ratiosAgC1:Ag and NaC1:Ag and assuming N = 14-008, give for theatomic weights of sodium, silver, and chlorine the values Na =22.9985, Ag = 107.88 and C1 = 35-457.6Aluminium-Aluminium chloride was synthesised from itselements, repeatedly sublimed in pure nitrogen and in a vacuum,distilled into bulbs, weighed, and used for determinations of theratio AlCI, : 3Ag by the usual method of gravi-volumetric titration.The mean of eleven results ranging from 26.962 to 26.978 is A1 =Chlorine.-Direct gravimetric determination of the weight ofsilver chloride precipitated by hydrogen chloride from a solutionof weighed silver in nitric acid has given for the ratio Ag : AgCla mean value 100 : 132.863 & 0.0009,8 in close agreement with thevalue of Richards and Wells.gCobalt.-Samples of cobaltous chloride, prepared from a meteoriteof unknown history and from terrestrial sources, were dried andsublimed in hydrogen chloride, fused and weighed in a quartzboat, and analysed by titration with weighed silver in the usualway. Three determinations of the ratio CoCI, : 2Ag for meteoriticmaterial gave the mean value Co = 58.942, seven determinationsupon terrestrial cobalt gave in mean the substantially identicalresult Co = 58-940.1° The final mean, however, is lower by 0.03than that found in previous investigations.llCopper.-Pure cupric oxide was heated first at 1000" in air andthen a t 800" in oxygen and weighed quantities were then reducedin hydrogen at 700-750". Eight determinations thus of the ratioCuO : Cu gave in mean Cu = 63.546 & 0.003.12Germanium.-Germanium tetrachloride, prepared from zincoxide residues and purified by fractional distillation in a vacuum,was used for determinations of the ratio GeCl,: 4Ag, giving inmean Ge = 72.60.13Bromine.-Purified bromine, distilled in an evacuated glass6 E.Zintl and A. Meuwsen, 2. anorg. Chem., 1924, 136, 223; A., ii, 608.7 H. Krepelka, J . Amer. Chem. Soc., 1924, 46, 1343; A., ii, 763.* R. Lorenz and E. Bergheimer, 2. anorg. Chem., 1924, 138, 205; A.,0 T. W. Richards and H. L. Wells, Publ. Carnegie Inst. Wash., 1905, No. 28.10 G. P. Baxter and M.J. Dorcas, J . Amer. Chem. Soc., 1924, 46, 357;11 T. W. Richards and G. P. Baxter, A., 1900, ii, 78; G. P. Baxter and12 R. Ruer and K. Bode, 2. anorg. Chem., 1924, 137, 101; A., ii, 761.1s G. P. Baxter and W. C. Cooper, jun., PTOC. Amer. Acad. Arts Sci.,26.972 & 0.001.7ii, 679.A,, ii, 341.I?. B. Coffin, A., 1906, ii, 858.1924, 59, 235; A., ii, 690INORGANIC CHEMISTRY. 29apparatus, was collected in bulbs, weighed, reduced with excessof ammoniacal ammonium arsenite, and titrated nephelometricallywith weighed silver : the resulting silver bromide was also collected,dried, and weighed. Ten determinations of the ratio Br : Ag andnine determinations of the ratio Br : AgBr give in mean Br = 79.916(Ag = 107*880).14Yttrium.-Yttria freed from other earths, especially holmium,by fractional crystallisation as bromate, preceded and followedby fractional precipitation with ammonia, was further purifiedby precipitation as chloride, by saturating its aqueous solutionat 0" with hydrogen chloride, and used for determinations of theratios YCl, : 3AgC1 and YCl, : 3Ag.The results with the purestfraction gave in mean Y = 88.950 & 0.010, in agreement withAston's conclusion that ytt'rium is a simple element of atomicweight 89.15Antimony .-Two import ant determinations for this clementhave to be recorded. I n one investigation antimonic acid, purifiedby repeated precipitation as chloroantimonic acid from a solutionof antimony pentachloride saturated with hydrogen chloride, wasreduced to metal in purc hydrogen.Samples of the trichlorideand tribromide prepared from this metal were then fractionallydistilled, first in purc nitrogen and then in a vacuum, and used fordeterminations of the ratios to silver and silver halide, 32 concordantanalyses giving in mean Sb = 121.76 (Ag = 107.88 ; C1 = 35.457 ;Br = 79*916).16In another case, Kahlbaum's purest antimony was twice fusedin hydrogen and combined with pure chlorine, and the antimonytrichloride was repeatedly distilled in an evacuated glass apparatus,considerable head and tail fractions being rejected in each distillation.Nine samples collected in weighed bulbs from the main fractionsof six of the later distillations, used for determinations of the ratioSbCl, : 3Ag in the usual way, gave in mean Sb = 121.748 &0.00086,17 in good agreement with the preceding value and withthat of Willard and &Alpine (Sb = 121.77),18 but much higherthan the older value (Sb = 120.2).One point may well be stressed in connexion with these results.I n view of the widely differing atomic weights found by Muzaffar l91 4 0.Honigschmid and E. Zintl, Annalen, 1923, 433, 201 ; A,, ii, 35.15 0. Honigschmid and A. Meuwsen, 2. anorg. Chem., 1924, 140, 341;16 0. Honigschmid, E. Zintl, and M. Linhard, ihid., 136, 257; A., ii,1 7 P. F. Weatherill, J . Amer. Chern. SOC., 1924, 46, 2437.18 H.H.Willard and R.K.McAlpine, ibid., 1921,43, 797; A., 1921, ii, 405.19 Ann. Report, 1923, 20, 31.A., ii, 860.61930 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRP.for ant,imony from various known sources, it is obviously mostunfortunate that both these excellent determinations were madeupon samples of antimony of unknown origin.I n order that everydetermination of atomic weight may add its quota to our knowledgeof isotopy and of the origin of the elemenh, it is now essentialthat the origin of the material investigated shall be ascertainedwith the greatest possible precision.Lead.--Lead tetraphenyl, prepared from lead extracted from aVesuvian cotunnite, was purified by alternate crystallisations frombenzene and chloroform and by treatment with absolute alcohol.iVeighed quantities were then converted directly to lead bromideby t,reatment with bromine. Determinations thus of the ratioPb(C,H5), : PbBr, gave in mean the value Pb = 207.050, appre-ciably lower than the value (207.192) obtained by tlie same methodfor ordinary lead .20The Effect of Intensive Drying.Important contributions have been made to our knowledge ofthe effect of intensive drying.Further experiments 2 l have con-firmed that benzene, even after drying for less than a year, behavesas a mixture and on distillation shows a progressive rise of temper-ature both in the liquid and in the vapour, the maximum temperatureobserved being 87.7" in the vapour.22The beliaviour of sulphur trioxide has been a mystery ever sinceMarignac, more than seventy years ago, observed that this substanceexisted in two solid forms, a mystery which has but been deepenedby recent investigation^.^^ Smits and Schoenmaker have now 24discussed the earlier results and communicated observations onintensively dried sulphur trioxide which shed much light on thisdifficult problem.Pure sulphur trioxide was distilled into anapparatus consisting of two bulbs connected by a U-tube filledwith pure phosphoric oxide and was therein distilled back and forthdaily for a month until dry. By the use of ingenious means, for itdescription of which the original paper must be consulted, the drymaterial was distilled into a second apparatus provided with aglass-spring manometer and a number of receivers into whichfractions of the sulphur trioxide could be distilled and sealed off.20 A. Piutti and D. Rligliacci, Atti R. Accad. Lincei, 1923, [vJ, 32, ii, 468;Guzzetta, 1924, 54, 605; A., ii, 181, 850.21 Compare Ann. Report, 1923, 20, 32.22 A.Smits, J., 1924, 125, 1068.23 Compare Ann. Beport, 1923, 20, 51; Le Blanc and Riihle, Ber. Mat.24 A. Smits and P. Schoenmaker, J., 1924, 125, 2554.phys. Kk1.58. Sacha. A h d . Whs., 1922, 74, 106INORGANIC CHEMISTRY. 31The results are best expressed by a P-7' diagram (Fig. l), wherevapour pressure is plotted against temperature.The original substance gave the data ( X ) shown on t,lic curve I :after standing 18 hours, molten at 18", it gave the pressures (0)plotted on curve 11. These vapour pressure values rise to a maxi-mum, then fall, then rise again. During the f d l in vapour pressure,the solid melts, in this case over a range of temperature from 13.3"Pto 16.7".After another 30 hours a t 18", curve 111 was obtained;and upon evaporating off and removing successive fractions of thesulphur trioxide, the residual material gave successively the curvesI V , V and VI.These curves present the following features : the first portions(on the left), representing in each case the equilibrium betweensolid and vapour, exhibit a rising vapour pressure but a t progres-sively lower ranges ; the middle portions, representing the equili-brium between solid, liquid, and vapour, lie always on t'he samethree-phase line PBQ, showing a faU of vapour pressure durin32 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.melting for fractions above the line ABC and a rise of vapourpressure during melting for fractions below that line; the lastportions of the curves (to the right of the line PBQ), representingequilibrium between liquid and vapour, show for successive fractionsa similar relation to that of the solid-vapour curves but with smallerdifferences.It is scarcely necessary to point out that these very remarkableobservations are quite unaccountable on the older views of thedifferent states of aggregation : they accord perfectly, however,with the behaviour to be anticipated in the equilibrium solid-liquid-vapour for a system of two components giving a dissociablecompound and hence strongly support Smits’s theory of allot’ropy.It is clear that the low-melting “ice” form of sulphur trioxide,with which only the present paper is concerned, contains twomolecular species in equilibrium, the transformation between thesespecies being so slowed by intensive drying that the complexityof the system becomes apparent.The varied and puzzling dataobtained by previous observers are evidently attributable to theeffect of greater or less self-drying of the sulphur trioxide in givingpartial evidence of the binary behaviour here fully exhibited.Preliminary results with the “ low-melting ” and “ high-melting ”“ asbestos ” forms of sulphur trioxide show that these, too, exhibitsimilar complexity when dried.Another series of experiments 25 showed that pure phosphoruspentoxide (which is, of course, strongly self-drying) exhibitedgreat differences in vapour pressure, according to the conditionsof distillation under which it was prepared, and is therefore complex ;and that at 400” the metastable sublimate changes into anothermodification, with a fall in vapour pressure from about 4 atms.to nearly zero, and this transformed solid phase melts over a widerange, beginning a t 563” and a vapour pressure (of 0.59 atm.) muchlower than that exhibited by the metastable form a t lowertemperatures, These results again may be explained by, andtherefore support, the view that both forms of phosphoric oxideare complex.I n this connexion, it is interesting to note that a detailed examin-ation of the specific heat-temperature curves for a number of liquidsshows that some, especially those for benzene, ethylbenzene,and carbon tetrachloride, exhibit irregularities held to indicatethat these liquids are associated and undergo molecular changeswith change of temperature, These irregularities are much moreevident when the liquids have been thoroughly (but not intensively)dried than when they contain a trace of water.MeasurementsA. Smits and A. J. Rutgers, J., 1924, 125, 2573INORGANIC CHEMISTRY. 33of vapour pressure and density over the same range of temperaturefail to show any irregularity.Z6Group I .Hydrogen is absorbed by cerium and by alloys of cerium with otherrare-earth metals above 300", or, if the metal has previously beenmelted in a vacuum, rapidly a t the ordinary temperature. Theproducts saturated a t 20" are greyish-black powders containingnearly 2% by weight of hydrogen, and that prepared from cerium is* spontaneously inflammable.When the hydrogen pressure is plottedagainst the volume of gas absorbed, curves are obtained, similarto those of Hoitsema and Roozeboom for the palladium-hydrogensystem, which suggest the formation of two non-miscible solid solu-tions but afford no evidence that definite hydrides are formed.27Vspour pressure measurements for pure hydrogen-peroxide(99.98% H20,) from 5-90" indicate that the boiling point is 151.1'and the molecular latent heat of evaporation is 11,610 cal. ; fromthe latter value is deduced a value for Trouton's constant, 27.3,showing that liquid hydrogen peroxide is associated. The calculatedcritical temperature for hydrogen peroxide is 468.8' .z8Hydrogen peroxide is stabilised by hydrofluoric acid, but isdecomposed by hydrobromic or hydrochloric acid a t all concentra-tions. A detailed investigation for the latter case shows that withlow acid concentrations the reaction is unimolecular and oxygenonly is evolved, but that for any concentration of hydrogen peroxidethere is a critical concentration of hydrochloric acid above whichthe velocity coefficient becomes proportional to the concentrationof acid and both chlorine and oxygen are evolved.It is suggestedthat the following reactions occur :( a ) H202 + HCl H,02,HC1;( 6 ) H,02,HC1 + H20<gy + H,O + HOC'1;( c ) HOCl + H,O, + H20 + 0, + HCl;( d ) HOCl + HC1 e= C1, + H20.The decomposition of hydrogen peroxide by halogens is attributedto the formation of oxy-acids which then react with the peroxideas in ( c ) above.29Despite serious experimental difficulties, it has been shown thatin the electrolysis of lithium hydride the hydrogen (at the anode)29 J.W. Williams and F. Daniels, J . Amer. Chem. SOC., 1924, 46, 1569;for details of the apparatus and method, see ibid., p. 903; A,, ii, 589, 450.27 A. Sieverts and G. Miiller-Goldegg, 2. anorg. Chena., 1924, 131, 6 5 ;d., ii, 185.28 0. M~aas and P. G. Hiebert, J . Amer. Chem. SOC., 1924, 46, 2693.29 Idem, ibid., p. 290; A,, ii, 326.REP.-VOL. XXI 34 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and lithium are evolved in the relative amounts required by Fara-day's law.30 This affords further evidence that in the hydrides ofthe alkali and alkaline-earth metals hydrogen acts as a halogen.31Ihvestigation of the vapour pressures of systems of water withlithium chloride, bromide, and iodide shows that each forms hydrateswith 3, 2, and 1 mols.of water, and the iodide a fourth hydratealso with 0.5 mol. of ~ a t e r . ~ 2By rapidly heating lithium monosulphide to 360" in a vacuumand treating the product with hydrogen sulphide diluted withhydrogen, nearly pure lithium sulphide is obtained as a buff -colouredpowder. Alcoholic solutions of the sulphide dissolve much sulphurand on evaporation can then be made to yield slightly impurelithium disulphide, but no higher polysulphide could be isolated.Thus it appears that the polysulphides of the alkali metals becomeless stable and more difficult to prepare with decreasing atomicweight of the meta1.33A phase-rule investigation of the systems formed by potassiumcyanide with water and each of the cyanides of univalent copper,silver, gold, and thallium a t 25" confirms the existence of severalknown compounds and shows that the new compoundsK,Ag(CN),,H,O, KAg,(CN),,H,O, and KTl(CN), also exist in theappropriate systems.%In determining the compressibilities of certain alkali halides,it has been observed that freshly-fused rubidium bromide and iodideand caesium bromide undergo a permanent contraction in volumeof about 1%, this change oocurring rapidly under high pressureand slowly on standing under ordinary condition^.^^Cuprous oxide, whether that formed by the action of nitrogenperoxide on copper or the anhydrous ignited crystalline materal,when treated with nitrogen peroxide in the cold takes up about30% by weight of that gas without change in appearance, evolutionof heat, or other sign of chemical change.The product dissociztescompletely on heating, without reduction of the nitrogen peroxide :it reacts violently with water, yielding nitric oxide and a solutionof cupric nitrate with a little nitrite, probably through the reactions :(i) 2N02 + H,O s HNO, + HNO,; (ii) 3HN0, e HNO, +2N0 + H20 ; (iii) 3cu,o + 14HN0, -3 6Cu(NO,), + 2N0 + 7H,O.SO K. Peters, 8. anorg. Chem., 1924, 131, 140; A,, ii, 174.81 Ann. Report, 1922, 19, 41.82 G. F. Hiittig and F. Pohle, 2. anorg. Chem., 1924, 138, 1 ; G. F.Huttigand F. Renscher, ibid., 137, 155; A., ii, 676, 756.33 J. S. Thomas and J. H. Jones, J., 1924, 125, 2207.3 5 T. W. Richards apd E. P. R. Saereils, J . Ainer. Chent. SOC., 1024, 46,H. Bassett and A. S . Corbet, ibid., p. 1660.934; A., ii, 408INORGANIC CHBMISTRY. 36At 65-70', the whole of the nitrogen peroxide is removed from thisassociation with cuprous oxide by an inert solvent, such as carbontet'rachloride, leaving a residue of cuprous oxide. Hence it isconcluded that the peroxide is adsorbed by, and not chemicallycombined with, the cuprous oxide.36Some interesting work on the formation of silver nitride fromsilver ammonium fluoride and on the conditions of formation offulminating silver from solutions of silver oxide in ammonia deservesmention, but cannot well be s~mrnarised.~~By a repetition and extension of work previously reported,38Hartung, using two Steele-Grant microbalances, one carrying105 mg.and the other 43 mg. and both sensitive to 2 x mg.,and an apparatus improved in several important respects, has shownthat by insolating thin films of silver bromide on flat silica supportsin evacuated vessels containing a suitable halogen absorbent, pre-ferably metallic copper, more than 96% of the bromine may beexpelled. Investigation of the rate of bromination of thin silverfilms gives no evidence of the formation of silver sub-bromides,and there seems no reason to doubt that the production of a latentimage when silver halides are illuminated for very short periodsis due to incipient decomposition into silver and bromine of the typehere studied.39An X-ray analysis of a sample of purple of Cassius gives clearindication of the presence of crystalline gold and stannic oxideand confirms the view that this substance is merely a mixture ofcolloidal gold and colloidal stannic acid.4OBrief reference may be made to the reported formation of goldfrom mercury in mercury-vapour arc lamps.41 Although atomiodisruption is not necessarily involved,42 the observation must awaitfurther confirmation, especially as the reported formation of heliumfrom tungsten 43 cannot be verified by other observers.4436 J.R. Park and J. R. Partington, J., 1924, 125, 72; J. R. Partington,ibid., p. 663; A., ii, 183, 340.*' L. J.Olmer and Dervin, Bull. SOC. chim., 1924, [iv], 35, 152; L. J.Olmer, aid., pp. 333, 845; A., ii, 410, 679.3a Ann. Report, 1922, 19, 43.30 E. J. Hartung, J., 1924, 125, 2198.40 A. Huber, PhysikaZ. Z., 1924, 25, 43; A . , ii, 229.'l A. Miethe, Naturwiss., July 18, 1924. For methods used in estimatinggold, nee A. Miethe and H. Stammreich, 2. anorg. C'hern., 1924, 140, 368;A., ii, 874.42 F. Soddy, Nature, 1924, 114, 244; A., ii, 684.44 Sinclair Smith, Proc. Nat. Acad. Arts Sci., 1924, 10, 4 ; 6. K. Allisonand W. D. Harkins, J . Amer. Chem. SOC., 1924, 46, 814; A . , ii, 407; con-firmed by a series of experiments made in the Reporter's laboratory ; H. V. A.Briscoe, P. L. Robinson, and G. E. Stephensan, J., 1925, 127, 240.Ann. Report, 1922, 19, 30.C 36 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Group I I .Calcium oxide reacts with nitrogen peroxide at all temperaturesup t o 400", giving calcium nitrate and nitrite, nitric oxide and nitro-gen.The free nitrogen arises from the oxidation of calcium nitriteto nitrate by the peroxide, which may occur in the following ways :(i) Ca(NO,), + 2N0, + Ca(NO,), + 2NO; (ii) 2Ca(NO,), +2N0 +2Ca(N03), + N,. Thus a loss of nitrogen may occur (forexample, in nitrogen fixation processes using lime as an absor-bent) to the extent of 5% of that originally present as peroxide.Calcium nitrite is not oxidised by oxygen below the temperature(230") at which i t begins to decompose according to the scheme :Ca(NO,), ++ CaO + NO + NO,. The cxistence of the compoundCa(N0,),,4H20 was c ~ n f i r m e d .~ ~At temperatures above 1 loo", calcium carbide dissociates intoits elements : this dissociation is the first stage in the formationof calcium cyanamide, which is believed to occur by way of thefollowing reactions : (i) 3CaC, -+ 3Ca + 6C; (ii) 3Ca + N, +Ca3N,; (iii) Ca3N2 + 3C + 2N, + 3CaCN2. Calcium chlorideaccelerates the decomposition of calcium carbide and its favourableinfluence in the cyanamide process is hereby explained .46Metallic barium and strontium, prepared according to the methodof Guntz 47 by reducing with coarse aluminium powder a mixture ofthe oxide with 10% of peroxide, when redistilled from a small resis-tance furnace contained in an evacuated glass vessel, yielded verypure samples of these elements (about 20 g. of each, containing lessthan 0.1 yo of impurity).Both metals are silver-white, crystalline,and as soft and malleable as sodium ; barium is spontaneously inflam-mable in moist air or hydrogen and tarnishes rapidly in pure, drycarbon dioxide; strontium is but little less reactive.48 Less purespecimens of metallic strontium have been prepared by reducingthe oxide wit,h silicon or high-grade ferrosilicon at 1250".49In the absence of oxygen, zinc oxide is not reduced by carbon atloOOo, but a small quantity of oxygen causes reduction a t a muchlower temperature, Reaction between carbon monoxide and zincoxide begins a t 420" and it is to this action that the reduction bycarbon under ordinary conditions is due.5045 J.R. Partington and F. A. Williams, J., 1924, 125, 947.48 H. J. Krase and J. Y. Yee, J . Amer. Chem. SOC., 1924, 46, 1358; A.,ii, 758; but compare 0. Ruff and E. Foerster, 2. anorg. Chem., 1923, 131,321 ; A., ii, 256.47 A. Guntz, Ann. Chim. Phy8., 1905, [viii], 4, 5; 1907, 10, 437; Bd. SOC.chim., 1906, [iiij, 35, 503.4 8 P. S. Darner, J . Amer. Chem. SOC., 1924, 46, 2382.49 C. Matignon, Compt. rend., 1923, 177, 1116; A., ii, 44.50 A. d'Hooghe, Bull. Acad. Roy. Belg., 1923, 9, 323; A., ii, (illINORGANIC CHEMISTRY. 37The primary product of the interaction of mercury and nitricacid is mercurous nitrite. The yield of this salt is highest with26% nitric acid at 30", is increased by the presence of mercurousor ferric nitrate, and is reduced to zero if sodium nitrite or ureais added to the nitric acid or if the temperature rises above 52'.Ferrous sulphate reduces nitric acid to nitrous acid and thus acceler-ates the solution of mercury in the acid.51Group I I I .A new hydride of boron, formulated as B,H>, and probablyB5H10, has been found among the products formed on heatingtetraborane, The new hydride cannot be separated fromB,H, by fractional distillation or condensation, but its presenceis shown by the marked depression of the freezing point of B,H,;it decomposes rapidly at the ordinary temperature (B5H, can thusbe freed from it by keeping), yielding hydrogen and a non-volatile,yellow hydride insoluble in carbon disulphide but soluble in waterand probably identical with the yellow decomposition productof B,Hlo described previously.It is now found that the hydride B,H, combines additively withammonia at the ordinary temperature to form the compoundB,Hg(NH,), : this compound, treated with hydrogen chloride,yields at first B5H5C3,(NH,)4 and by prolonged action B5H,C1,(NH,),,and this substituted ammine, dissolved in water, yields hydrogenand a strongly reducing solution giving a characteristic precipitatewith sulphates.A second new hydride, B5Hll, has been isolatedfrom the decomposition products of diborane; it is a colourless,mobile liquid which does not solidify at -. 110" and rapidly decom-poses at the ordinary temperature, yielding hydrogen and the solidhydride B10H14, m. p. 9 9 ~ 5 O .~ ~Thermal investigation of the ternary alloy system Al-Cd-Znshows that the chief feature of the liquidus surface is a deep valleyjoining almost linearly the eutectics at 94.470 Zn and 380" and at17.4% Zn and 268" in the Zn-A1 and Zn-Cd series, respectively.=Specimens of the hydroxides of aluminium, chromium, and zinc,prepared in various ways and of various ages up t o 4 years, wereexamined by the Debye-Schemer method of X-ray analysis withthe following results. At the ordinary temperature, gelatinousaluminium hydroxide slowly changes into crystalline hydrargillite,but the freshly-precipitated substance, when heated at 100" for51 C. C. Palit and N. R. Dhar, 2. nnorg. Chem., 1924, 134, 191; A., ii, 486.52 Ann. Report, 1923, 20, 38.53 A.Stock and W. Siecke, Ber., 1924, 57, [ B ] , 5G2; A . , ii, 40554 N. F. Budgen, J., 1924, 125, 164238 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.some time, tends to form microcrystalline bauxite : zino hydroxide,air-dried a t the ordinary temperature, is partly crystalline andbecomes more so by ageing: chromium hydroxide, even whenaged, shows no sign of crystalline structure.55Solutions of aluminium chloride in carbonyl chloride react withmany metals, forming double salts which, in the case of calciumand magnesium, are soluble and do not impede the action bycoating the metal. From the solution obtained with calcium, acompound, CaC1,,2A1C13,3COC12, has been isolated ; i t readily losescarbonyl chloride (dissociation pressure 25 mm. a t 19.5") and onheating loses aluminium chloride to form the known compound3CaC12,4A1C1,.56Aluminium chloride and sulphur chloride unite to form a com-pound, AlCl3,3S2C1,, which on chlorination yields AlCl,,SCl, andAlCl,,SCl, and combines with sulphur to form AlC1,,2S3C1, andAlC1,,2S4C1,. All these compounds are red, uncrystallisable liquids,insoluble in sulphur chloride. On extraction with carbon di-sulphide, the last two lose sulphur chloride and leave solid residues,A1C1,,2S2 and AlCl,,S,, which react with water, depositing sulphurbut yielding no hydrogen sulphide. It is hence concluded that theyare co-ordination compounds of aluminium chloride with thepolythiochlorides, S,C12 and S,Cl,, the presence of which in solutionsof sulphur in sulphur chloride is postulated to account for theobserved changes in boiling point with increasing sulphur contentin such solutions.57The system thallic oxide-sulphur trioxide-water yields two com-pounds only, HTl( S0,),,4H20 and OH.T1SO4,2H,O, both stableonly in strongly acid solutions and readily hydrolysed by water.The changes in transition temperature between these salts with acidconcentration have been determined : a t 25" the basic salt is inequilibrium with acid concentrations from 10-40% and the acidsalt with concentrations from 42-75% : thallic oxide does notdissolve in more concentrated acid.It is supposed that the hepta-hydrated normal salt described by Crookes and by Strecker musthave been a molecular mixture of the two salts now found.Analogousthallic selenates, HT1(Se0,),,2H20 and OHTlSeO,,H,O, are foundto be the only selenates capable of separate existence and they closelyresemble the sulphates in their solubility relat.ions and in theirsensitiveness to water.66 R. Fricke and F. Wever, Z. anorg. Chem., 1924, 136, 321; A., ii, 616;compare R. Willstiitter and H. Kraut, Ber., 1924, 57, [B], 1082; A., ii, 615.56 A. F. 0. Germann and K. Gagoa, J. Ph.y.qical Chem., 1924,28, 965; A.,ii, 861.6 7 0. Ruff and H. Golla, 2. nnorg. Chern., 1924, 138, 17, 33; A . , ii, 672,684INORGANIC CHBMISTRY. 39Thallic hydroxide dissolves in a saturated solution of ammoniumsulphate, and from this solution at 0" addition of ammonia andalcohol precipitates a compound, T1,(S04),,12NH,,12H20, stableonly in an atmosphere of ammonia : a similar selenium compoundwas also isolated.T1,Se04,T1,(Se04), ;a yellow double salt, 5Tl,Se04,Tl,(Se04)3, analogous to the knowndouble sulphate, and certain other salts containing both halogenand the sulphate or selenate radical have been prepared.58By examination of the arc spectra and X-ray spectra of neodymia-samaria fractions of rare-earth material, search has been made forthe element of atomic number G1, but without s u c c e ~ s .~ ~Normal carbonates of cerium, lanthanum, neodymium, andpraseodymium, of the type E20,,3C0,,8H,0, are obtained byprecipitating 2% solutions of the chlorides with a solution of sodiumhydrogen carbonate saturated with carbon dioxide. They are atfirst amorphous, but rapidly become crystalline, and when air-driedhave the formula given above; drying in a vacuum over sulphuricacid produces the dihydrate; drying at 100" yields the mono-hydrate ; prolonged heating a t 200" in carbon dioxide removes theremaining water and yields the anhydrous normal carbonates.When heated with excess of water, the carbonates lose one-third oftheir carbon dioxide, forming basic carbonates of the typeOH*E*CO,.The normal carbonates, heated in an atmosphere ofcarbon dioxide, are stable up to 300" and thereafter lose carbondioxide, rapidly at 400", all except cerous carbonate forming thebasic carbonate, E2O,,CO2, stable at a high temperature (La, 900" ;Pr, 815"; Nd, 800"). Above these temperatures, the lanthanumand praseodymium compounds are rapidly converted into oxides :the neodymium compound is first converted into Nd203,4C02,stable up to 870", and then yields the oxide.The decompositionof cerous carbonate is complicated by the intermediate formationof the ceric compounds, Ce20,,3CO2 and Ce,O,,$CO,, which at 900"yield ceric oxide.60Work published on the complex sulphates of quadrivalent cerium,on double sulphites of the alkalis with cerium, lanthanum, anddidymium, and on the chromates of lanthanum, praseodymium,neodymium, and samarium cannot usefully be summarised.61A colourless thallo-thallic selenate,O 8 J. Meyer and H. Wilk, 2. nnorg. Chem., 1923, 132, 239; A., ii, 259.69 L. F. Yntema, J. Amer. Chem. SOC., 1924, 46, 37; W. Prandtl and A.6o J.Preiss and A. Dussik, ibid., 1923, 131, 275; J. Preiss and N. Rainer,V. Cuttica, Gazzetta, 19123, 53, 761, 769; H. T. S. Britton, J., 1924,Grimm, 2. anorg. Chem., 1924, 136, 283; A., ii, 185, 615.ibid., p. 287; A . , 1924, ii, 261, 262.125, 1875; A., ii, 112, 11340 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.An investigation of pure praseodymia prepared by basic precipit-ation 62 confirms the curious fact that the composition of this oxideconforms almost exactly to the composition Pr,0,,.63A study of the effect of mixtures of ceria and thoria on the com-bination of hydrogen and oxygen a t 450" shows that their catalyticactivity exactly parallels their light-giving powers in the incan-descence mantle in that it is a maximum for the mixture containing1% of ceria and is the same for pure thoria as for the mixturecontaining 9% of ~eria.6~Group I V .The relationship of rate of loss of weight of pure carbon filamentsto the temperature a t which they were heated in a helium atmo-sphere at known pressure, and certain other observations, indicate,although they cannot prove, that carbon has a vapour pressure ofabout 1 mm.a t 2400°.65X-Ray analysis of thirty-four different forms of " amorphous "carbon establishes their essential identity with each other and withgraphite,e6 and measurements of the real density of various charcoalsare held to indicate that they all consist of graphite contaminatedwith hydrocarbons.Carbon monoxide is readily absorbed by a solution of silversulphate in sulphuric acid, the rate of absorption increasing withthe concentration of the acid : in a vacuum, the gas is again liberatedin a manner dependent on the temperature.68Further investigation of the compound formerly called '' oxydisi-lin " and formulated as Si,H*OH,69 obtained by the action ofdilute hydrochloric acid on calcium silicide, 70 has afforded evidencethat it has the constitution formulated below, and it is renamed'' siloxen. "SiH62 W.Prandtl and K. Huttner, 2. anorg. Chem., 1924,136,289; A . , ii, 615.63 P. M.-P. Brinton and Pagel, J . Amer. Chem. SOC., 1923, 45, 1460.64 R. L. Swan, J . , 1924, 125, 780.EB A. Thiel and F. Ritter, 2. anorg. Chem., 1923, 132, 125; A , , ii, 253.6 6 G. Asahara, Japan J . Chem., 1922,1, 3 5 ; A., ii, 172.G 7 H.C. Howard and G. A. Rulctt, J . Physical Chem., 1924. 28, 1082;68 W. Manchot et alii, Ber.. 1924, 57. [Bl, 1157; A., ii, 609.6* H. Kautsky, 2. anorg. Chem., 1921, 117, 209; A . , 1921, ii, 505.70 H. Kautsky and G. Herzberg, 2. angew. Chem., 1923, 36, 508.A , ii, 823INORGANIC CHEMISTRY. 41The bromine derivative (formerly described as '' silica1 bromide '7and an iodine derivative now obtained are Si6H303Br3 andSi,H3O31,. Tribromosiloxen, when treated with bromine sufficientto form hexabromosiloxen, absorbs it completely and is convertedinto a yellow solid readily hydrolysed to a black hydroxy-derivative ;greater proportions of bromine are also absorbed, but to form colour-less compounds which yield colourless hydration products : henceit is inferred that siloxen contains six hydrogen atoms similarlyunited to silicon.Siloxen, when exhaustively chlorinated, yieldshexachlorodisiloxan, SiCl,*O*SiCl,, and when treated with methylalcohol and ammonia yields hexamethoxydisiloxan, O[Si(OMe)3]2,hence the oxygen atoms are believed t o be directly linked each tatwo silicon atoms.71 Various other reactions of these compounds aredescribed in the papers cited.A silicon analogue of calcium cyanamide, CaSiN,, is formed,together with calcium silicocyanide and silicon, by interactionbetween nitrogen and calcium disilicide, a t 1150", thus :2CaSi, + 2N, -+ CaSiN, + Si + Ca(SiN),.The reaction is greatly accelerated by the presence of calcium chlorideor of less than 5% of calcium fluoride, and then occurs at as lowa temperature as 850".Neither the silicocyanamide nor the silico-cyanide could be isolated from the reaction product, but bothdissolved in hydrochloric acid without separation of silica.',A relatively large amount of germanium has been extracted fromgermanite, from Tsumeb, S.W. Africa, which contains 5.1y0 ofgermanium and 0.57% of gallium. Metallic germanium was pre-pared by reducing the dioxide with potassium cyanide andcharcoal . 73Important work has been published on the hydrides of germa-n i ~ m . 7 ~ When heated a t about 500" in hydrogen, powdered germa-nium (3 parts) reacts with arsenic-free magnesium turnings (2 parts)with evolution of much heat, the mass glowing brightly, to formdark-grey, granular magnesium germanide.By slowly addingdilute hydrochloric acid to this compound in a flask filled withpure hydrogen, a gaseous mixture of germanium hydrides withhydrogen was obtained containing about 23% of the total germa-nium used. This mixture was separated and the constituents wereexamined by means of an apparatus (the construction and use ofwhich are described in detail in the original) similar to that used71 H. Kautsky and G. Herzberg, Ber., 1924, 57, [ B ] , 1665; H. Kautskyand H. Thiele, 2. angew. Chem., 1924, 37, 540; A., ii, 852, 674.72 L. Wohler and 0. Sock, 2. anorg. Chem., 1924, 134, 221; A . , ii, 473.73 J. R. Thomas and W. Pugh, J., 1024, 125, 816.74 L. M. Dennis, R. B. Corey, and R. W. Moore, J . -4nier. Chem. Soc., 1921,46, 657; A., ii, 343.c42 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.by Stock for the study of the hydrides of silicon.75 To test thisapparatus, Stock's work on the isolation, analysis, and determin-ation of physical constants of pure monosilane and disilane wasrepeated and confirmed in all details.Fractional distillation andcondensation of the germanium hydrides yielded three fractionsconsisting of monogermane, GeH4, digermane, Ge2He, and triger-mane, Ge,H,, and a small amount of liquid residue which probablycontained higher hydrides. Of the total amount of germaniumobtained as hydrides, 73.6% was present as monogermane, 22%as digermane, and 1% as trigermane. The identity of the hydrideswas proved by analysis (by thermal decomposition into germaniumand hydrogen) and by determinations of gaseous density.Mono-germane has already been d e ~ c r i b e d . ~ ~Digermane is a colourless liquid, m. p. - log", b. p. 29",&loS" 1-98; its vapour-pressure curve was plotted from - 98" to + 30". Trigermane is also a liquid, m. p. - 105.6", b. p. 110.5",d-105'6* 2.20 ; its vapour-pressure curve was determined from2.4" - 111.5". Thermal dissociation at a pressure of 200 mm.begins with digermane a t 214-218" and with trigermane a t 194";in the latter case, a small quantity of a clear, colourless liquid ofhigh b .p. , possibly a polymerised unsaturated hydride, was formedin small quantity.When exposed to air, digermane turns yellow, then light brown,and finally yields a dark brown solid ; it i s not ordinarily spontaneouslyinflammable, but readily ignites and burns vigorously, leaving aresidue streaked white and black and brown.The action of oxygenon digermane in one case caused spontaneous inflammation ; usuallyno action occurs a t first, but after 10 minutes the liquid deposits awhite solid which after a time turns yellow, Trigermane behavesin a very similar way with air and oxygen.Liquid digermane is immiscible with water, but reacts after a timeto produce a white, gelatinous solid which gradually turns yellowand then light brown, a gas being evolved a t the interface betweenthe liquids. With 33 yo sodium hydroxide solution, liquid diger-mane, unlike monogermane and trigermane, reacts to produce acolourless, combustible gas, although in insufficient quantity foridentification.Both digermane and trigermane dissolve in carbontetrachloride with evolution of heat, forming a clear solution whichdeposits a white solid on exposure to air.74When an aqueous solution of germanium dioxide is evaporatedand the residue is heated to any temperature between 225' and1100", part of the oxide is insoluble in water and very inert toward7 6 A. St.ock and K. Somieski, Ber., 1916, 49, 111; A., 1916, ii, 319.76 Ann. Report, 1923, 20, 43IN ORGAN10 CHEMISTRY. 43acids and alkalis. The yield of insoluble is highest when the residueis heated to 380", but the mode of increase of this yield with durationof heating is such as to indicate that it can never exceed a certainsmall value, e .g., about 15yo at 280". All specimens of' the oxidemelt between 1090" and 1100" to a viscons liquid which solidifiesto a, colourless glass, readily and completely soluble in boilingwater. Therefore it seems probable that germanium dioxide existsin two or more allotropic modifi~ations.~~Further investigation of zirconium minerals has confirmed thefact that hafnium is always associated with zirconium, although, ingeneral, minerals rich in zirconium are poor in hafnium, whilst thosepoor in zirconium and containing a large quantity of rare-earthsare rich in hafnium : thortveitite from Madagascar contains 3.2%HfO, and only 2% ZrO,, and a Norwegian thortveitite similarlyshowed a high proportion of The foregoing general-isation is supported by the finding that zirconium from variousminerals has an atomic weight which is higher when the contentof rare-earths is high.79 Examination of the optical spectrum ofhafnium shows that many of the strong hafnium lines have previ-ously been recorded as weak spark lines of zirconium.80Zirconia prepared from the normal sulphate by ignition a t 1000"has d m 5.73, whilst hafnia similarly prepared and containing lessthan 0.5% ZrO, has dm" 9.67.These values are constant andreproducible provided that the method of preparation of the oxideis the same ; hence the considerable difference between them affordsa convenient and accurate means of determining the proportionsof zirconia and hafnia in mixed oxides, the percentage of hafniabeing given by d -5.73!0.0394, where d is the density at 20" of themixed oxide prepared as described above.s1Anomalies in a previous investigation of the atomic weight ofzirconium are now definitely traced to a small and varying contentof hafnium in the material used.s2Work on the stannic acids, which cannot be described in detail here,is held to afford evidence that unstable but definite monostannicacids can exist of the type Sn(OH),H,, Sn(OH),, or Sn0(OH)2.837 7 J.H. Muller and H. R. Blank, J . Amer. Chem. SOC., 1924, 46, 2358.' 8 G. von Hevesy and V. T. Jantzen, Chem. New*, 1924, 128, 341; E.i 9 E. Urbain and G. Urbain, Compt. rend., 1924, 178, 265; A., ii, 194.80 H. M. Hansen and S. Werner, Nature, 1923, 112, 900; A,, ii, 79.81 G. von Hevesy and V.Berglund, J., 1924, 125, 2372.82 F, P. Venable and J. M. Bell, J . Amer. Chem. SOC., 1924, 46, 1833; A.,83 R. Willstiitter, H. Kraut, and W. Fremery, Ber., 1924, 57, [ B ] , 63,ano9y. Chem., 1924, 133, 113, 387; A., ii, 402, 571, 620.ii, 690.1491; A., ii, 266, 767.c* 44 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Lead tetrachloride purified by distillation in a high vacuumdissolves in benzene and its homologues to give deep brownish-redsolutions which, if dilute, may be kept without change for severalhours in the dark, but if concentrated decompose with explosiveviolence after some little time. The brown colour of the solutionsis discharged by addition of carbon tetrachloride, chloroform,ethylene dibromide, acetic acid, or ether, without deposition of leaddichloride.84Interaction of lead salts and disodium hydrogen phosphate inaqueous solution a t the ordinary temperature yields a t first tertiarylead phosphate, Pb,(PO,),, but by prolonged contact with thesolution this is converted into the secondary salt, PbHPO,, whichis the equilibrium product, stable over a wide range of concentrationof phosphoric acid (0 - 49% P,O, a t 25").With higher concentra-tions of acid, the primary phosphate, PbH,(PO,),, is the stable solidpha~e.~5Group V .Pure ammonia, containing only a trace of hydrogen as impurity,may be obtained by allowing pure calcium or magnesium nitrideto fall into water. Commercial ammonium salts always containorganic matter, corresponding with about 06y0 of carbon in thesamples examined, but this can be destroyed by oxidation withnitric acid or permanganate a t high temperatures and the residualsalt will yield pure ammonia by the usual methods.86Dry mixtures of ammonia with electrolytic gas become explosivewhen the ratio of electrolytic gas to ammonia is slightly greaterthan 1, 79% of the ammonia being then decomposed ; when thisratio is a little higher than 3, the ammonia is wholly decomposed,the gaseous products containing only steam, hydrogen, and nitrogen.Explosion of ammonia with a deficiency of oxygen causes completedecomposition of the excess of ammonia, oxides of nitrogen beingformed only if the ratio of ammonia to oxygen is less than 1.6.When oxides of nitrogen are so formed, the proportion of nitrogenoxidised is greater than in the explosion of a corresponding mixtureof nitrogen, hydrogen, andEquilibrium values for the reaction &" + $H2 + NH, have beendetermined, first for the range 10-100 atms., and 325-500", andlater for the range 300-1000 atms., and the temperatures 450°,475", and 500", and show that a t 1000 atms.and 450" the proportionof ammonia a t equilibrium is 69-4 yo. 8884 E. Krause, Ber., 1924, 57, [B], 318; A., ii, 259.85 L. T. Fairhall, J . Amer. Chem. Soc., 1924, 46, 1593; A., ii, 612.8 6 L. Rloser and R. Herzner, Monatsh., 1923, 44, 115.87 J. R. Partington and A. J. Prince, J., 1024, 125, 2018.8 8 A. T. Larson and R. L. Dodge, J . Arner. C'hent. Xoc., 1023, 45, 2918;A. T. Larsoii, ibid., 1024, 46, 367; A., ii, 331INORGANIC CHEMISTRY.45A catalyst, " nitroxan," consisting of an equimolecular mixtureof barium metaplumbate and barium manganate is able to effectcomplete oxidation of ammonia to nitric acid, which, at temperaturesbelow 450", is retained by the catalyst as barium nitrate. Thisnitrate may be removed by lixiviation and replaced by bariumhydroxide to regenerate the ~atalyst.8~By the action of amalgamated aluminium on a solution ofpotassamide in liquid ammonia, potassium ammonoaluminate,Al(NH,),,KNH,, is obtained ; it crystallises in colourless needlesand resembles the sodium salt previously described When heatedtto 50" in a vacuum, it yields a white, non-crystalline substance,Al( NH,),*NHK.Potassium ammonomanganite, Mn(NHK),,2NH3, is obtained bythe slow action of metallic manganese on a solution of potassamidein liquid ammonia, or, more readily, by interaction of potassamideand manganous thiocyanate in this solvent; it forms cream-coloured crystals which oxidise rapidly in air and are vigorouslyhydrolysed by water.If the manganous thiocyanate is in excess,impure manganous amide, Mn(NH,),, is obtained.g1Improved methods are described for the preparation of hypo-nitrites,92 and the mechanism of the thermal decomposition of saltsof hydroxylamine and hydrazine and of the oxidation of hydrazinehas been in~estigated.~,Interesting work has been done on the oxidation of phosphorus.The statement that a blast of air can detach the luminosity fromphosphorus and cause it to move down-stream 94 is confirmed andit is shown that inhibitors, e.g., carbon disulphide, have no effectwhen introduced into the glow, but extinguish it when introducedon the up-stream side between the glow and the phosphorus.Thevelocity of blast necessary to detach the glow from the phosphorusvaries enormously with temperature and oxygen concentration,being less the higher the oxygen content of the blast and the lowerthe temperature. This velocity is evidently a measure of the rateof propagation of the glow, which therefore appears to be due toan oxidation of the vapour of phosphorus or oxides of phosphoruscatalysed by the products of combustion. The known extinctionof the glow is thus seen to be the limiting case of slow propagation,8 9 G.Kassner, Z. anyew. Chent., 1924, 37, 373; d., ii, 604.QO Ann. Report, 1923, 20, 48.9 1 F. W. Bergstrom, J . Amer. Chem. SOC., 1924, 46, 1545; A,, ii, 607.Q2 L, W. Jones and A. W. Scott, ibid., p. 2172; E. Weitz and W. Vollmer,Ber., 1924, 57, [B], 1015; A., ii, 850, 608.93 K. A. Hofmann and F. Kro11, Ber., 1924, 57, [B], 937; E. J. Cuy,et dii, J . Amer. Chern. SOC., 1924, 48, 1786, 1796, 1810; A., ii, 645, 672,673.Q4 L. and E. Rloch, Compt. rend., 1908,147, 842; A., 1908, 103246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and the extinction by inhibiting substances such as carbon disulphide,turpentine, or oxygen, is interpreted as a case of catalyst poisoning.I n dry oxygen, similar phenomena are observed, gave that the glowpersists a t all ordinary temperatures but is sharply extinguished ata lower temperature, about - 20°.95 Further experiments havenow shown conclusively that, as would appear from the foregoingobservations, the oxidation of phosphorus by moist oxygen occursslowly even when there is no visible glow, and that this " dark "reaction is a volume reaction occurring in the vapour phase and nota surface action.If phosphorus is confined in oxygen at, say, 15",and the pressure is reduced, the glow begins sharply a t a certaindefinite pressure. If the pressure is then first slightly increased(thus extinguishing the glow) and then again lowered without delay,the glow begins a t a slightly higher pressure than in the first case,as if some kind of initial resistance to glowing had been broken down.This resistancc is recovered if the extinction of the glow is main-tained for a minute or more.By taking advantage of this curiousfact, it is possible to arrange that a t a given temperature andpressure in the same gas the phosphorus may either glow or remaindark : oxidation occurs in either case, but a t very different rates,the time required for the absorption of a given volume of oxygenbeing about 145 times greater when the phosphorus is dark thanwhen it is glowing.96The spectrum of the flame of phosphorus, whether burning in airenriched with oxygen or in'air a t reduced pressure, shows seriesof bands in the same position, but in the latter case resolved intosmaller bands identical with those observed in the glow ofphosphorus.97 It has further been shown that the amount ofozone formed during the oxidation of phosphorus is proportional tothe intensity of the glow and, what is more important, that the glowof phosphorus or of phosphorous oxide can ozonise oxygen and ioniseair separated from the glowing material by a window of quartz orfluorite 2 mm.Considering all these facts in relation toprevious knowledge (which is well summarised in the paper lastcited), there is evidently strong reason to believe that the coldoxidation of phosphorus first produces phosphorous oxide, thefurther oxidation of the latter under appropriate conditions emittingboth the visible glow and light of very short wave-length whichcauses the observed production of ozone and gaseous ions.95 Lord Rayleigh, Proc. Roy.SOC., 1923, [ A ] , 104, 322; A., 1923, ii, 765.96 Idem, ihid., 1924, [ A ] , 108, 1 ; A., ii, 605; Bee also K. R. Krishna Tyer,97 H. J. Emel6us and W. E. Downey, J., 1924, 125, 2491.s 4 W. E. Downey, ibid., p. 347.Chem. News, 1923, 127, 321; A., ii, 39INORGANIC CHEMISTRY. 47Oxidation of hypophosphorous acid by c hrornic acid proceeds bya reaction which is unimolecular with regard to each reactant, doesnot involve hydrogen ions, and may be represented as occurring intwo stages :H3P0, + Cr,O," -+H,PO, + Cr2O8" ;2H3P0, + Cr,O," + 8H' -+2H,PO, + 2Cr"' + 4H,O ;of which the first only is measurable. This reaction thus givesno information as to t,he existence of an active form of the acid.1On the other hand, the interaction of phosphorous acid with mercuricchloride affords confirmatory evidence of the existence of a second,active form of this acid.2The conditions of formation of various orthophosphates of lithium,magnesium, zinc, and beryllium have been defined and some newsalts isolated, vix., lithium diammonium phosphate, Li(NH4)2P0, ;primary beryllium phosphate, Be(H2P04)2, and the double salt2Be(H2P04),,BeHP04.3I n the course of experiments on the preparation of the hydrideAs2H2, a new arsenic hydride, As,H2, was obtained as a red, non-crystalline, insoluble solid, decomposing when heated to yieldfree arsenic, arsine, and hydrogen. It results from the oxidationof arsine by stannic chloride in presence of hydrochloric acid : itis unchanged by boiling water or hydrochloric acid, yields arsenicwhen treated with a boiling concentrated solution of alkali or fusedalkali, and is oxidised to arsenic acid by nitric acid, bromine, orhydrogen peroxide.*Arsenides of several metals (Cu,As ; Pb,As, ; Hg3As ; AuAs ;Ag3As; BiAs; Cd3As2; Fe,As2; Ni,As,) have been prepared bydropping an aqueous solution of a salt of the metal into an atmosphereof arsenic trihydride free from air.They are black substances,readily oxidised in air to form the metal and arsenious acid, andigniting spontaneously when dry; a t high temperatures in theabsence of air, the arsenides of the noble metals are almost completelydissociated, whilst the others yield arsenic and a lower arsenide.Dilute acids and alkalis have no action on the arsenides of copper,gold, and bismuth, but liberate arsine from the arsenides of lead and~admium.~Reinvestigation of the supposed suboxide of bismuth shows thatas prepared by heating the basic oxalate or reducing the hydroxide1 A.D. Mitchell, J . , 1924, 125, 664.8 Travers and (Mle) Perron, Ann. Chim., 1924, [XI, 1, 135, 298; A , ,4 L. Moser and A. Brukl, MonatPA., 1924, 45, 25; A., ii, 851.6 A. Brukl, 2. anorg. Chem., 1923, 131, 236; A., ii, 251.Tdem, ibid., p. 1013.ii, 676, 67748 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.it is of variable composition and contains less bismuth than corre-sponds with the formula BiO. Metallic bismuth can be extractedfrom the oxide by shaking it with mercury, and when heated in dryhydrogen sulphide for many hours it behaves as a mixture of metal,trioxide, and hydroxide, each of which reacts with the gas a t adifferent rate.The heat of reaction with hydrochloric acid, thesolubility in aqueous caustic soda, and the specific magnetic suscepti-bility for the supposed suboxide have values indistinguishable fromthose given by a mixture of bismuth (1 atom) and bismuth trioxide(1 mol.) ; hence it is concluded that the suboxide does not exist .6Group V I .The residual oxygen left on explosion of pure ozone or rich mix-tures of ozone with oxygen contains much less ozone than it shouldin accordance with the Nernst heat theorem.' On the other hand,the silver test shows that flames of hydrogen, coal-gas, methane,ethylene, acetylene, carbon monoxide, and cyanogen containquantities of ozone (0.1% in the oxyhydrogen flame a t 1500" and1 yo in the acetylene blowpipe flame) much too great to be accountedfor solely by thermal formation according to the Nernst theorem,I n the cases of carbon monoxide and cyanogen, the yield of ozoneis not diminished by drying the gases, therefore it seems improbablethat hydrogen peroxide plays any part in its formation.8 If hydrogen,coal-gas, or acetylene is supplied to the inner jet and oxygen to theouter jet of a small blowpipe, and a small flame so formed is causedto impinge directly on a water-cooled silica tube, a considerableyield of ozone is obtained and its production may readily bedemonstrated on the lecture table.gDeterminations of the vapour pressure curve for pure ozonefrom - 169" (4.8 mm.) to - 1086" (840.8 mm.) indicate that theb.p. at 760 mm. is - 110.7".10Sulphur vapour shows a maximum absorption for light a t aboutX = 2750 8., corresponding on the radiation theory with a criticalincrement of 51,760 cal. per gram-atom of sulphur, in close agree-ment with that calculated from the temperature coefficient of thethermal gaseous reaction between hydrogen and sulphur. I nagreement with hypothesis, ultra-violet radiation of this wave-6 E. Neusser, 2. anorg. Chern., 1924, 138, 180, 313; A., ii, 691, 559.7 E. H. Riesenfeld and M. Beja, ibid., p. 245; A., ii, 470; compare H. v.Wartenburg and B. Sieg, Ber., 1920, 53, [BJ, 2192; A., 1921, ii, 107.8 W.Manchot and E. Bauer, 2. anorg. Chem., 1924, 133, 341; A., ii, 543.9 K. A. Hofmann and P. Kronenberg, Ber., 1924, 57, [B], 1200; A . ,10 E. H. Riesenfeld and M. Beja, 2. anorg. Chem., 1923, 132, 179; A . ,ii, 603.ii, 248INORGANIC CHEMISTRY, 49length was found to be active in initiating a photochemical reactionbetween hydrogen and sulphur vapour proportional to the pressureof the latter. The conclusion drawn is that the activation of sulphurmolecules may occur both by radiation and by collision, that ineither case the energy of activation is constant, and hence thatthe latter case is amenable, not to the Newtonian laws of inelasticimpact, but to those of quantum dynamics, the same amount ofenergy being extracted from the colliding molecules whatever theforce of their impact, provided this exceeds a certain magnitude.llA mixture of silver fluoride and sulphur heated in a vacuumyields a considerable volume of gas, having V.D.97.3 and containing64-04y0 S and 35.17% F and believed to be impure disulphur di-fluoride, S,F,. The gas is colourless, has an odour similar to buteven more objectionable than that of sulphur chloride, and isimmediately decomposed by moisture with deposition of sulphur .I2Pure sodium thiosulphate is readily obtained when sodiumhydrosulphide (1 mol.) and sodium hydrogen sulphite (2 mols.)are mixed in aqueous solution; the reaction proceeds well alsobetween sodium sulphide and sulphur dioxide or between sodiumsulphite and hydrogen sulphide provided there is present sufficientsodium hydroxide to produce ultimately sodium hydrosulphide andbisulphite in the correct proportion.A mechanism for the reactionis suggested.13The action of dry hydrogen sulphide on a suspension of leadthiosulphate in absolute alcohol yields an alcoholic solution ofthiosulphuric acid which is stable for some time, but after a few daysdecomposes, giving sulphur and pentathionic acid. An aqueoussolution of thiosulphuric acid, stable for about an hour a t 15",can be prepared by adding a little concentrated aqueous sodiumthiosulphate to fuming hydrochloric acid .I4Pentathionic acid is formed by the action of sulphur dioxide onan aqueous suspension of sulphur according to the scheme :5s + 6S0, + 2H,0+2H,S,06.This reaction, together with thedirect formation of tetrathionic acid in Wackenroder's solution,thus, 3SO,+H,S -+H,S,06, can account for all the cases of form-ation of polythionic acids hitherto 0b~erved.l~None of the methods described in the literature for the prepar-ation of pyrosulphates yields the pure salts; they can only beobtained by direct union of the sulphates with sulphur trioxide11 R. G. W. Norrish and E. K. Rideal, J., 1924,125, 2070.12 M. Centnerszwer and C. Strenk, Ber., 1923, 56, [ B ] , 2249; A., ii, 167.l3 F. Foerster and E. T. Mommsen, ibid., 1924, 57, [Bj, 258; A., ii, 248.1 4 J. Casares Gil and J. Beato, ibid., 1923, 56, [BJ, 2451 ; A., ii, 104.1 5 E. Josephy, 2. anorg. Chem., 1924, 135, 21; A., ii, 470$0 ANNUATJ REPORTS ON THE PROGRESS OF CHEMISTRY.under anhydrous conditions.The acid sulphates cannot be com-pletely dehydrated even under reduced pressure of in an atmosphereof sulphw trioxide. Sodium pyrosulphhte is a white, crystallinesolid, m. p. 400*9", dt? 2.658, dissociating rapidly a t 460" anddeliquescing in moist air to sodium hydrogen sulphate. This salt,m. p. 185*7", forms with the pyrosulphate a system showing aeutectic a t 182-7" and 6.8 mol. yo of pyrosulphate. Potasaiutupyrosulphate crystallises in transparent, colourless prisms, m. p.414.2", @? 2,512, and on cooling changes at 315" to an opaque,porcelain-like mass and gives thermal indications of a secondtransformation at 225". With potassium hydrogen sulphate, itforms a eutectic a t 201.2" and 14 mol.yo of pyrosulphate.16Powdered tellurium heated in carbonyl chloride yields telluriumdichloride as a brown vapour condensing to a velvety black, crystal-line solid which is decomposed by water to yield tellurium and theoxychloride TeOCl,. By repeated sublimation with small quantitiesof ammonium chloride, the dichloride forms ammonium chloro-tellurite, (NH,),TeCl,, as a greenish-black mass stable in air.17Pure metallic chromium may be obtained by reducing chromicoxide at 1500" in perfectly dry hydrogen.18A new salt of tervalent molybdenum, the oxysulphateMo,O(SO,),,xH,O(.r: = 5 or 6), is obtained by electrolytic reductionof a solution of molybdenum trioxide in sulphuric acid and can beisolated by pouring the electrolyte into acetone under exclusion ofair.It is a green, hygroscopic solid, very readily hydrolysed andoxidised.19 A number of double salts containing the chloride,bromide, or fluoride of tervalent molybdenum have also beendescribed,m and much additional information has been publishedon the " dichlorides " of molybdenum, tungsten, and tantalum.21Good deposits of very pure tungsten are formed by electrolysisof solutions of tungstic acid (1 part) in a fused mixture of sodiumand potassium chlorides (not less than 2 parts). With higherproportions of tungstic acid in the electrolyte, various bronzes areproduced.22 Metallic uranium containing 99.9 yo U can be obtained16 L. Cambi and G. Bozza, Ann. Chim. Applicata, 1923, 13, 221; A.,1 7 K.Lindner and L. Apolant, 2. anorg. Chem., 1924,136, 381 ; A,, ii, 604.I* W. Rob, 2. Mehllk., 1924, 16, 275; A., ii, 617.19 W. Wardlaw, F. H. Nicholls, and N. D. Sylvester, J., 1924, 125, 1910.20 A. Rosenheim and T. H. Li, Ber., 1923, 56, [B], 2228; A., ii, 193.2 1 K. Lindner, ct alii, 2. anorg. Chem., 1923, 130, 209; 1924, 137, 66;140, 357; A., ii, 192, 768, 864; compare Ann. Report, 1922,19, 67; see also0. Collenberg and K. Sandved, 2. anorg. Chem., 1923, 130, 1; A., ii, 51.23 L. and H. H. Kahlenberg, Tnms. Amer. Electrochem. rSoc., 1924, 46,51 ; A., ii, 766.ii, 37INORGANIC CHEMISTRY, 51in 27% yield by reduction of uranium dioxide with calcium in acrucible thickly lined with lime.23Group V I I .The most satisfactory method for the preparation of fluorine isthe electrolysis of fused potassium hydrogen fluoride,2* and animproved generator is now described capable of yielding 4 litres offluorine an hour for 20-30 hours.The electrolyte is regeneratedby adding hydrogen fluoride and is then freed from water byelectrolysis in a separate cell until fluorine is evolved. Heating ofthis anhydrous material in a copper retort yields pure anhydroushydrogen fluoride : this was found to have a f . p. - 83" and thevapour-pressure curve was determined from that temperature up to47". Measurements of the vapour density of pure hydrogen fluorideup to the boiling point, combined with those of Thorpe and Hambly 25for higher temperatures, indicate that the vapour is an equilibriummixture of HF and (HF),, the heat of association being 6670 cals.per mol .z6Generation of hydrogen fluoride from calcium fluoride andsulphuric acid proceeds best at relatively high temperatures andwith an excess of calcium fluoride.The converse conditions, andlow concentration of water in the sulphuric acid, favour the formationof fluorosulphonic acid; this is but slowly hydrolysed, even at loo",to form hydrogen fluoride and sulphuric acid, which then attacksthe residual calcium fl~oride.~'Silicon tetrafluoride and water vapour do not react a t temper-atures between 30" and 125", and the vapour evolved by hydro-fluosilicic acid, if dried by sulphuric acid or other desiccating agents,cannot again be condensed. Thus it appears that hydrofluosilicicacid exists only in aqueous solution and not, under ordinary con-ditions, in the vapour phase and is a non-volatile acid like carbonicor sulphurous acid.28It has been found that chlorine hydrate prepared in presence ofexcess of liquid chlorine has the composition C12,6H,0 .29Further work on the photochemical union of hydrogen andchlorine has confirmed Mellor's conclusion that the initial expansion23 W.Jander, 2. anorg. Chem., 1024, 138, 321; A., ii, 767.23 Ann. Report, 1919, 16, 49.a5 J., 18'39, 55, 163.26 J. Simom, J . Amer. Chem. SOC., 1924, 46, 2175, 2179; J. Simons and27 W. Traube and W. Lange, Ber., 1924, 57, [B], 1038; A., ii, 609.28 C. A. Jacobson, J. Physical Chem., 1923, 27, 761; 1924, 28, 506; A.,*9 A. Bouzat and L. AziniBres, Compt.rend., 1923, 177, 1444; A., ii, 103.J. H. Hildebrand, ibid., p. 2183; A., ii, 847, 848.ii, 105, 78252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.(the Draper effect) is a purely thermal effect of the initial com-bination. Observation of the effects of illumination by successivesparks (fully described in the original but difficult to summarise)leads to the conclusion that the union of hydrogen and chlorine isfor the most part a purely chemical process, although the firstimpulse is given by the light.30Reaction between gaseous ammonia and solid potassium chlorateis very vigorous and may become dangerous with high concentrationsof ammonia. Investigation of the reaction, controlled by dilutingthe chlorate with inert material and the ammonia with air, leads tothe view that it occurs according to the scheme : KClO, + 2NH,--,KCI + 2N + 3H,O ; KC10, + N +KN03 + C1; the incidence ofreaction being attributed to the formation of intermediate additjivecompounds by direct union between potassium chlorate andammonia, both of which are relatively ~ n s a t u r a t e d .~ ~At the ordinary temperature and in moderate concentrationsof sulphuric acid, potassium permariganate oxidises iodic acid,hydriodic acid, iodine cyanide, or iodine monochloride to periodicacid; in the last case, the oxidation is incomplete, as chloride ionhinders and may even inhibit the oxidation. The oxidation ofiodic acid is quantitative, and if the excess of permanganate isdestroyed by adding a nitrite, and the nitrite in turn is removed byadding excess of urea, the periodic acid formed may be estimated byreduction with hydriodic acid and titration of the liberated iodine.32Small amounts of pure metallic manganese may be obtained byelectrolysing with a rotating cathode an electrolyte containing 30 yoMnS04,4H,0, 10% (NH&SO4, and 0.25% H,SO,, and stable, semi-solid manganese amalgams are formed by electrolysis of the sameelectrolyte with a well-stirred mercury cathode.If the electrolytecontains the appropriate metallic sulphat,e, low-manganese alloyswith iron or nickel may similarly be 0btained.~3A search for the missing element No. 43, “ eka-manganese,”by examination of the X-ray spectra of a number of manganeseminerals has been unsuc~essful.~~30 F.Weigert and K. Kellermann, 2. physikal. Chem., 1923, 107, 1; A.,31 K. A. Hofmann and W. Linnmann, Ber., 1924, 57, [B], 818; A.,32 R. Lang, 2. anorg. Chem., 1923, 130, 141; A., ii, 166.33 A. J. Allmand and A. N. Campbell, Trans. Puraday SOC., 1924, 19,559; A. N. Campbell, J., 1924, 125, 1713; A., ii, 555, 764.84 C. H. Bosanquet and T. C. Keeley, Phil. Mag., 1924, Evil, 48, 145; A.,ii, 651.ii, 8.ii, 477INORGANIC CHEMISTRY. 53Group V I I I .A thorough study has been made of the desulphurisation of ironpyrites.35 I n dry air, it is practically complete a t 800-900"; inair saturated with water vapour, the rate of removal of sulphur isgreater below and less above 660" than the rate in dry air. Insteam, removal of sulphur begins a t 380" and the rate increasesrapidly to 500" and more slowly then to 680", at which temperaturethe solid phase is ferrous sulphide : on further heating, the ferroussulphide is oxidised to triferric tetroxide with evolution of hydrogenand hydrogen sulphide.The action of carbon monoxide generallyresembles that of steam. Carbon dioxide has no oxidising actionon pyrites below goo", but in this inert atmosphere dissociatiod ofthe mineral into ferrous sulphide and sulphur begins a t 580" and iscomplete a t 670". This is in good agreement with the observationthat the dissociation of pyrites in a vacuum begins a t 500", proceedsrapidly a t 550", and is complete a t 670-680°.36 From observations 35of the partial pressure of sulphur dioxide and sulphur trioxide, itis inferred that the oxidation of pyrites occurs through the inter-mediate formation and decomposition of a persulphate at lowtemperatures and of ferrous sulphate a t temperatures above about430".The volume of hydrogen absorbed by an ethereal nickel solcorresponds with the formation of a hydride NiH,, whilst the blackproduct dried in hydrogen has the formula NiH,; the fact that thishydride when treated with alcohol at once evolves hydrogen isregarded as additional evidence that the process of catalytic reductionin presence of nickel is essentially chemical and is due to the inter-mediate formation of nickel h ~ d r i d e .~ ~A new method has been devised for the preparation of certaindouble fluorides of potassium with metals of the platinum group.Finely-divided platinum or iridium is heated with the double plumbicfluoride, 3KF,HF,PbF,, in the latter case in a nickel crucible linedwith potassium fluoride.Potassium fluoroplatinate, K,PtF6, formspale yellow crystals, very slightly soluble in water (0*0023~0 a t 25").Potassium and lead fluoroiridiates are pink, crystalline solids, theformer sparingly soluble in water but insoluble in alcohol, the lattersoluble only in 10% ammonium acetate solution.3sOsmium tetroxide digested with concentrated hydrochloric35 F. C. Thompson and N. Tilling, J . SOC. Chem. Ind., 1924, 43, 37T; A.,36 (Mlle) G. Marchal, Bull. SOC. chipm., 1924, [iv], 35, 43; A., ii, 187.37 W. Schlenk and T. Weichselfelder, Ber., 1923, 56, [B], 2230; A., ii, 189.38 H. I. Schlesinger and M. W. Tapley, J . Anzer. Chem. SOC., 1924, 46, 276;ii, 341.A., ii, 34354 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.acid liberates from potassium iodide exactly 4 atoms of iodine permol. of OsO, and forms osmium hydroxytrichloride, Os(OH)Cl,,crystallising in long, brown needles containing water and yieldingwith alkali chlorides hydroxypentachloro-osmates of the typeMI,[ OsCI,*OH]. The hydroxytrichloride on hydrolysis forms theblack insoluble Os0,,2H20, which is reoxidised to the tetroxide bypotassium permanganate, absorbing 4 atoms of oxygen per mol.These facts are held to confirm the octavalency of osmium.39Certain complex sulpho-acids of platinum, a new series of acido-amidotetrammineplatinic salts of the type [Pt(NH,),NH,X]X,(X = C1, Br or NO,), and certain pentammine platinic salts havebeen described,4ORuthenium tetroxide and gaseous hydrogen chloride react toform tetrachloro-oxyruthenic acid as follows : RuO, + 6HC1+H,RuO,CI, + C1, + 2H,O. This acid crystallises with 3 mols.of water in reddish-brown, hygroscopic needles ; treated withconcentrated hydrochloric acid, it yields a reddish-brown solutioncontaining hexachlororuthenic acid and pentachlororuthenious acidthus : H,RuO,Cl, + 4HC1-+ H,RuCl,+C1,+ 2H20 ; 2H,RuC162H,RuCl, + Cl,.*lMeasurements of dissociation pressure indicate that between680" and 840" ruthenium trichloride dissociates directly into itselements without intermediate formation of lower chloridesYg2but the chlorination of finely-powdered ruthenium a t moderatetemperatures (360") by the action of chlorine containing carbonmonoxide can be made to yield a brown powder, consisting mainlyof ruthenium dichloride, which is insoluble in water and most othersolvents, but dissolves in alcohol to form a blue solution resemblingthat produced by reduction of ruthenium t r i c h l ~ r i d e . ~ ~The cEsium, rubidium, and ammonium ruthenates of the typesM1,Ru04 and the monohydrates of the two former, resembling thecorresponding potassium and three double sulphites of potas-sium or sodium with ruthenium hare been prepared.45H. V. A. BRISCOE.39 F. Krauss and D. Wilken, 2. anorg. Chem., 1924, 137, 349; A., ii, 772.60 L. Tschugaev and S. Krassikov, ibid., 1923, 131, 299; L. Tschugaev,ibid., 1924, 137, 1, 401; A., ii, 268, 769, 770.4 1 S. Aoyama, ibid., 138, 249; A., ii, 771.4e H. Remy and M. Kohn, ibid., 137, 365; A , , ii, 770.43 J . L. Howe, J. L. Howe, jun., and S. C. Ogburn, J . Amer. Chem. Soc.,1924, 46, 335; F. Krauss and H. Kukenthal, 2. anerg. Chem., 1924, 137, 32;A., ii, 344, 770.44 F. Krauss and H. Kukenthal, ibid., 182, 315; F. Kmw, ibid., p. 301;A., ii, 196.45 H. Remy and C. Breimeyer, ibid., lag, 215; A,, ii, 64

ISSN:0365-6217    

DOI:10.1039/AR9242100027

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

ORGANIC: CHEMISTRY.PART ALIPHATIC DIVISION.IN view of the large and increasing number of papers appearingfrom year to year, it has become impossible to include in thisReport even such a reasonable selection of researches as will furnisha compendium of progress in the whole of the special branch ofthe subject specified by the above title.The guidance and relief afforded by the Publication Committee aretherefore welcome. It has been decided that contributors shouldnow " aim a t presenting a homogeneous, consecutive, and interestingaccount of only such major themes as may have reached a well-marked stage during the period since they were last under review.This period may frequently be several years." An endeavour hasbeen made to fulfil this obligation in the following account, whichconsequently deals with fewer topics than the Reports of past years.Optical Activity.On comparing the specific inductive capacities of compoundsof the type RX, for long wave-lengths and a t normal temperatures,it is found that the substituent group X exerts a graded influencerepresented by the order :CH C1 Br I Et Me & CODOH CHO CO*CH, CN go2,that is, the values of the speoific inductive capacities vary in accord-ance with the gradual transition of X from a highly negative to ahighly positive polarity.This also roughly corresponds with theorder indicating the relative polarity of the groups as deduced fromthe data of benzene substitution. The dissociation constants ofsubstituted acids, in which one or other of the above series ofsubstituents represents the group X, show a similar sequence ortransition.It is now demonstrated that, in general, the replaoe-ment of a hydrogen atom in an optically active compound by apositive substituent displaces the rotation in the opposite sense tothat due to a negative substituent, and that the magnitude of thedisplacement corresponds more or less closely to the position of thesubstituent in the above polar series.It is clear that discrepancies arise where isolated values of rota56 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion taken in a limited range of solvents only are available, andwhere other data depend on conditions unfavourable for a truecomparison.Evidence drawn from the electromagnetic rotation of benzeneand its substitution products reveals a similar sequence in the degreeof polarity of positive and negative substituents.On these considerations a hypothesis of fundamental importancehas been founded.1 It is pointed out that the rotation of an opticallyactive compound is probably related to the electrostatic momentof the groups attached to the asymmetric carbon atom, and manyof the determinations of specific rotation, confined to a singleseries containing variable substituents, fully bear out this view.The new hypothesis appears nearer to the truth than the conceptionof P.F. Frankland postulating a mechanical moment, and known8s the “lever-arm-theory ,” and is, moreover, capable of great develop-ment. Where the substituent groups attached to an asymmetriccentre contain double linkings or chromophoric groups, the problemis presented as to how far, if a t all, the asymmetric centre mayrespond to the special characteristic of such substituents, such aspolar activation, or absorption frequencies.It is concluded that,instead of the adoption by such centres of these characteristics, thespecialised types of substituents themselves exhibit induced asym-metry, and probably contribute directly to the rotatory powerof the molecule.A new chapter in the study of the phenomenon of mutarotationis opened out by the discovery3 that beryllium benzoylcamphorundergoes reversible isomeric change. The mutarotation is especi-ally pronounced in chloroform, but has been observed also inbenzene, acetone, alcohol, heptane, and cyclohexane.The rate ofthe change is greatly accelerated by traces of piperidine or benzoicacid. The beryllium benzoylcamphor combines additively withchloroform, separating from a solution in glassy prisms containingtwo molecular proportions of chloroform which are gradually elimin-ated on keeping. It has already been established by X-ray analysisthat in beryllium acetate each beryllium atom in the co-ordinatedcomplex is surrounded by four oxygen atoms situated at the cornersof a tetrahedron of which the metallic atom occupies the centre.On assigning a similar configuration to beryllium benzoylcamphor,it is seen that the benzoylcamphor radical is unsymmetrical andtwo stereoisomeric co-ordination compounds are possible, and inH. G.Rule, J., 1924, 125, 1121; H. G. Rule and T. R. Paterson, ibid.,T. M. Lowry and E. E. Walker, Nature, 1924, 113, 565; A,, ii, 373.H. Burgess and T. M. Lowry, J., 1924, 125, 2081.p. 2155ORGANIC CHEMISTRY. 57both these forms the beryllium atom is asymmetric. The dynamicisomerism of the compound is analogous to that of M- and P-glucoseand, since the mutarotation change must proceed through a thirdor intermediate form, it is suggested that the ring system of theco-ordination complex (I) opens out to produce a form in whichthe beryllium atom momentarily loses its optical activity as does thereducing group of a hexose :The conception that the mutarotation of sugars is dependent onthe intermediate formation of a hydrate has been adversely criti-cised, and the simpler view that the aldose or ketose itself displaysdynamic isomerism is supported by a dynamical investigation andby a series of crucial experiments.* The oximes, anilides, and hydra-zones of sugars all show mutarotation, and the hypothesis of theformation of an aldose hydrate which functions as an intermediateproduct can obviously not apply to these cases.5 The mechanismof mutarotation is best expressed by regarding it as a simpletautomeric change :H Y - -70 -7-OHo ~ ~ H ~ o H ) , =+ (YH-OH), =s= O+H~OH),YH YH*OH \$H8-sugar.aldo- or keto-form. a-sugar.Considerations based on the hypothesis of additive optical super-position lead to unexpected results in regard to the stereochemicalform of several aceto-halogen derivatives of sugars.Althoughacetobromoglucose is transformed into p-methylglucoside by itsreaction with methyl alcohol followed by deacetylation, yet thehalogen derivative is now, apparently, to be regarded as anar-compound.6An interesting study of catalytic racemisation is afforded by aninvestigation on the Z-menthyl phenylhalogenoacetates.' WhenJ. W. Baker, C. K. Ingold, and J. F. Thorpe, J., 1924, 125, 268.R. Gilmour, ibid., p. 705.C. 5. Hudson, J. Amer. Chem. SOC., 1924, 46, 462, 477; A., i, 371, 372;A. McKeneie and (Miss) I. A. Smith, J., 1924, 125, 1582.C. S. Hudson and K. P. Monroe, ibid., p. 979; A., i, 61758 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I-phenglbmmoacetic acid waB eaterified with I-menthol and hydrogenchloride, the resulting crystalline ester did not consist of the esterof the I-acid but of the d-acid. Catalytic racemisation had obvi-ously occurred during the esterification, the I-menthyl E-phenyl-bromoacetate being converted into a mixture of the diastereo-isomerides, crystallisation of which led to the isolation of thed-isomeride.The reveraibility of this phenomenon is indicated by conductinga similar experiment with the latter isomeride.Digestion withalcoholic hydrogen chloride led to the isolation of a mixed ester inwhich the Z-acid was in a preponderance over the d-acid and fromthis mixture the homogeneous 2-ester was separated.This series of striking interconversions of enantiomorphousvarieties is summarised by the following scheme :-I-Ph*CHBr*CO,H 4 Ph*CHBr*CO,C,,H,, + Ph*CHBr*CO,C,H,,( I - ) ( I - ) (d-) ( I - IBy the agency of a single drop of potassium ethoxide it is shownto be possible to effect the following changes with the correspondingchloro-ester :The mechanism of the interconversion is probably indicatedby the scheme formulated below, except that a preponderance ofthe lzevo-ester is formed in the final stage :RC -OR’ ( I - )P H-Y-Cl (d-) ~ , t p ~ H-4-1 (d-) --EtOH, +- G-OR‘ ( I - )0 /\KO OEt? B H-F-Cl (d-) and C1-7-H ( I - )C0,R’ ( I - ) COZR‘ ( I - )This result is not in the orthodox sense an asymmetric synthesisORGANIC CHEMISTRY. 59but is an example of the influence of an optically active group indirecting, asymmetrically, a reversible isomeric change.A constant product of the action of yeast on sucrose solutions isI-malic acid,8 and the formation of this compound is promoted bythe addition of sodium hydrogen carbonate or sodium fumarate.The resolution of r-malic acid has been achieved by the use ofcin2honine and also by the application of ammonium molybdate.The r-ammonium molybdomalate is not deposited from solutionas such, but separates first as the l~evo- and then as the dextro-isomeride.lO From a mixture of the d- and h a l t s the opticalenantiomorphs can also be separated mechanically. Since thespecific rotation is of the order & 220°, the purity of the fractionscan readily be determined and the conversion of the salts to thefree d- and I-malic acids is a simple procedure.It is observed thatthe d-malic acid, obtained through chlorosuccinic acid by theWalden inversion, contains 250/, of the I-acid.There is no doubt as to the existence of definite compounds such2s the dimolybdomalates, 2Mo0,,C,H,0,,2NH3, and the molybdo-dimalates, Mo03,2C,H,0,,2NaOH ; and the rotatory and dispersivepowers of several such salts have been determined.llUranyl malate and uranyl tartrate are found to be, not neutralsalts, but complex acid salts of which disodium derivatives can beformed.12 The unexpectedly complex nature of such salts ismatched by the existence of complex antimonyl potassium tartrates,which appear to be formed when the antimony1 t r i o d e precipi-tated from potassium antimony1 tartrate redissolves in the excess ofalkali added.When a crystal of tartaric acid is cut normally to its optic axis,the section exhibits a rotatory dispersion of 2.14 as between theindigo and yellow rays, whereas for the tartrates the ratio is notmore than 1.8.The higher value is almost identical with thatobserved for the dispersion of tartaric acid in solution. Theconclusion is drawn l3 that the anomalous rotatory dispersion oftartaric acid is to be attributed to the existence of two isodynamiccc- and p-forms in equilibrium, the one being dextro- and the othera H. D. Dakin, J . Biol. Chem., 1924, 61, 139; A . , i, 1142.0 Idem, ibid., 1924, 59, 7 ; A , , i, 610.10 E. Darmois and J. Perin, Bull. SOC. chin&., 1924, [iv], 35, 353; A .,i , 610; compare A . , 1923, i, 299; idem, Compt. rend., 1923, 176, 391; A . ,1923, i, 300.11 E. Darmois, J . Phys. Radium, 1923, 4, 49; Conzpt. rend., 1923, 176,1140; A , , 1923, i, 299, 535.l a Idem, Compt. rend., 1923, 177, 49; A,, 1923, i, 751.l3 L. Longchambon, ibid., 1924, 178, 951 ; A., ii, 373; T. M. Lowry andP. C. Austin, ibid., p. 1902; A., i, 94060 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Isvo-rotatory, and since the dispersion 2-14 corresponds with aspecific rotation of - 70" this may be regarded as the rotatorypower of the laevorotatory component. The latter is thus neitheran anhydride nor an internal ether, but ordinary tartaric acid asit exists in the crystals. New work on the X-ray analysis of thecrystal structure has led to the suggestion that the above hypothesisof the existence of dynamic isomerides is unnecessary, and that thedextrorotatory component alone exists, partly, however, in anassociated or polymerised state, consisting of strings of moleculesjoined a t the hydrogen junctions of the hydroxyl groups,14 thestructure of the crystal being in part maintained.Combating thisview is the evidence from the study of changes in molecular weightand rotatory power of ethyl tartrate in formamide, benzene, andother solvents, the ester being chosen because it behaves throughoutas a higher homologue of amorphous tartaric acid. I n formamide,the ester is unimolecular, and the dispersion curves are complexin character.15 I n benzene, the molecular weight doubles its valueat a concentration of 20%, but the rotatory power increases up to10% and then decreases.Polymerisation is, in fact, accompaniedby an exaltation of rotation, whereas the crystallographic theorydemands the opposite result if the Izvorotatory component oftartaric acid is a polymeride. The absence of any parallelismbetween the changes in rotation and molecular weight seems todispose of the theory based on X-ray analysis.A hydrated, active tartaric acid l6 is obtained by crystallisingaqueous solutions below 5", but the crystals are only stable below10". Methylene tartaric acid and dimethylene tartrate have beenprepared,17 and their rotatory dispersion can be expressed in oneterm of Drude's equation. This is also true for d-sec-octyl alcohol,but its oxalate exhibits a complex dispersion which cannot beexpressed by the one-term equation or by Biot's law.18 The valueof the specific rotation of d-sec-octyl i-tartrate is in disagreementwith the hypothesis of optical superpo~ition.~~It has previously been recorded that the form of the curveobtained when l / a is plotted against A2 ( a = rotatory power a t wave-length A) is linear in the case of the simpler alcohols and ethers,whilst a hyperbolic curve is obtained for most esters.I n theformer case, the dispersions were expressed by the one-term equation,and in the latter by the two-term Drude equation, and these classi-14 W. T. Astbury, PTOC. Roy. SOC., 1923, [ A ] , 102, 506; A., 1923, i, 178.l5 T. M. Lowry and J.0. Cutter, J., 1924, 1% 1465.1e M. Amadori, Atti R. Accad. Lincei, 1924, [v], 33, i, 507; A., i, 1163.l7 P. C. Austin and V. A. Carpenter, J., 1924, 125, 1939.l8 T. M. Lowry and E. M. Richards, ibid., p. 1593.lS T. S. Patterson and C. Buchanan, ibid., p. 1475ORGANIC CHEMISTRY. 61fications have been designated as “ simple ” and “ complex ”dispersion and were held to represent cases of both optical and chem-ical homogeneity on the one hand and heterogeneity on the other.A homologous series of n-alkyl ethers of d-7-nonanol, ranging frommethyl to n-nonyl, has now been prepared, and their densities androtations have been determined.20 Their rotatory dispersions,with the exception of that of the methyl ether, cannot be repre-sented by the one-term Drude equation, and cases of optical hetero-geneity appear to occur, unaccompanied, however, by chemicalheterogeneity. The curve obtained by plotting rotations againstthe number of carbon atoms of the alkyl group in the series appearssmooth, except for depressions a t the 1h-propyl and the n-octylmembers, where the spiral of five additional atoms may be said toreturn on the a-carbon atom of the active alcohol.I n most of the earlier work, complex rotatory dispersionwas alwayscorrelated with the presence of a carboxyl or ester group in whichdynamic isomerism may occur, but in the results recorded above itis evident that complex dispersion is not restricted to compoundscontaining such groups.It is difficult to conceive of intramolecularchanges taking place in so simple a grouping as that of an ether,and it becomes evident that an explanation of these results must belooked for elsewhere.Dissatisfaction with this new system of classification has beenstrongly expressed, and one author 21 prefers a return to the oldersystem of distinguishing between normal and anomalous dispersion.It is urged that the evidence for the application of the one-termDrude equation is insufficient, and that any chemical significancein the two-term equation probably lies in the similarity or otherwiseof the signs.The ‘‘ complex ” rotatory dispersion associated withthe carboxyl group or its equivalent is held to be due to the presenceof one singly- and one doubly-linked oxygen atom unsymmetricallydisposed in each group.The study of the configuration of the series of amino-acids hasbeen actively continued on the lines of Clough, and it is establishedthat d-alanine belongs to the same series as Z-lactic acid.Z2 Thereaction of nitrous acid with alanine, serine, and aspartic acidoccurs without any Walden inversion, and these compounds, alongwith cystine, all have the same configuration.It is suggested thatall naturally occurring amino-acids belong to the same stereochemicalseries.23 p-Phthalimino- P-phenylpropionic acid has been resolved2O J. Kenyon and T. W. Barnes, J . , 1924,125, 1395.2l H. Hunter, ibid., p. 1198, 1389.22 K. Freudenberg and F. Rhino, Be?:, 1924, 57, ( B ] , 1547; A., i, 1173;23 P. Karrer, Helv. Chim. Acta, 1923, 6, 957; A ., i, 161.compare A . , 1023, i, 21562 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with cinchonine and the pure d-acid 0btained.2~ The same activeacid was obtained by the resolution of r- p-amino- p-phenylpropionicacid followed by heating the d-acid with phthalic anhydride. Thisacid, although lzvorotatory in ethyl acetate, belongs to the &series,accepting f3-phenylpropionic acid as the reference compound.It is announced that the possibility of the asymmetry of aliphaticdiazo-compounds has been eonfirmed. Crude diazosuccinic esterwas converted into bromosuccinic acid by hydrogen bromide 25and hydrolysis with hydrochloric acid. Fractional crystallisationgave a product which appeared to be fairly pure d-bromosuccinicacid having [aJD + 60.4".Since, however, the original crude diazo-compound was prepared from I-asparagine, it seems not unlikelythat i t was contaminated a t its source with malic acid, which mayaccount for the whole of the facts.A method of resolving some racemic alcohols into their opticallyactive components is reported, depending on the formation of adouble compound of the alcohol with digitonin.26 Separation occurson recrystallisation, and the active alcohol is isolated by distill-ation in a vacuum or in steam.A further stereochemical study of the alkyl piperazines has resultedin the isolation of the first optically active representatives of thistype of c0mpound.2~ The d- and I-1 : 4-diphenyl-2-methylpiper-azines have been separated by means of d-camphor- p-sulphonic acid.Alcohols and their Deriratives.A series of new experiments on the catalytic hydrogenation ofaldehydes in presence of nickel salts has been instituted with theobject of elucidating the constitution and mode of formation of theunexpected products obtained by previous workers who haveutilised this and other methods of catalytic reduction.It is found 28that ketones are converted smoothly into the corresponding secondaryalcohols, and aromatic aldehydes into the primary alcohols. Whenaliphatic aldehydes are employed, however, the product containsnot only the expected primary alcohol, but also the secondaryalcohols which arise from the doubling of the carbon chain. Theformation of these secondary products is ascribed to the condensation24 A.McKenzie and T. M. A. Tudhope, J., 1924, 125, 923; compare ibid.,26 P. A. Levene and L. A. Mikeska, J . Bid. Chem., 1922, 54, 101; 1923,26 A. Windaus, F. Klanhardt, and R. Weinhold, 2. phgsiol. Chem., 1923,9' F. B. Kipping and W. J. Pope, J . , 1024, 125, 2396.28 Julius von Braun and Gerd Kochendorfer, Ber., 1923, 66, LSJ, 2172;1921, 119, 69.55, 795; A., 1923, i, 25, 663.126, 308; A., 1923, i, 586.A., 1923, i, 1197ORGANIC CHEMISTRY. 63of the true aldehyde with its enolised form to give an unsaturatedketone :CHR:CH*OH + H*CO*CH,R --+ CHR:CH*COCH,R + H,O.This reaction is followed by the reduction of the ketone to a secondaryalcohol. An example of this kind may be illustrated by the formationfrom heptaldehyde of heptyl alcohol and hexylheptylcarbinol,C,H,,*CH( OH)*C,H1,.A number of alcohols have also beenprepared by catalytic hydrogenation of aldehydes in presence ofactivated magnesium .29I n presence of a suitable catalyst, such as iron covered withpotassium carbonate, carbon monoxide undergoes reduction withhydrogen a t 400--450", under 150 atmospheres, to a mixture ofalcohols, ketones, aldehydes, and other products. Using watergas as the initial material, this reaction proceeds with the formationof this mixture of products, which has been designated as " synthol,"and it has been applied for the purpose of manufacturing motorfuel. A theoretical consideration of this process 30 reveals the variousstages of the change represented by the conversion of carbon monoxideinto formaldehyde, which, in the absence of bases, passes intomethane. But in presence of the potassium carbonate used withthe catalyst, the formaldehyde is reduced to methyl alcohol, whichis converted either directly or through methyl formate into aceticacid, the stepwise reduction of which gives acetaldehyde and ethylalcohol, whilst its catalytic decomposition gives acetone. Arepetition of these operations yields the analogous members of thethree-carbon series, and so the process continues to the stage repre-sented by a chain of seven or eight carbon atoms.At this stage,the synthetic changes cease owing to the instability of the higherproducts under the experimental conditions employed.The conditions governing the " alcoholic fermentation " offormaldehyde by osmium have been submitted to careful invebtig-It is found that osmium catalyses the reduction offormaldehyde to methyl alcohol only when the metal is present inthe colloidal or highly dispersed condition. This condition isattained by adding to the formaldehyde a compound such as osmicacid, which is then reduced to a highly active form of the metal.A new method for the reduction of esters is described which leadsto almost theoretical yields of aliphatic alcohols.3~ An etherealBadische Anilin- und Soda-Fabrik, D.R.-P.384351 ; from Chem. Zentr.,1944, i, 2398; A., i , 1189.30 E. Fischer and H. Tropsch, Bet-., 1923, 56, [B], 2428; A., i, 131.81 E. MiiUer, 2. physikal. Chew&., 1923, 107, 347; A,, 1924, i, 833; cow-32 H.J. Prim, Rec. trav. china., 1923, 42, 1050; A., 1923, i, 1172.pare A.. 1922, i, 11064 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.solution of the ester is used, to which is added a solution of sodiumacetate to form a separate lower layer. At - 5", sodium and 80%acetic acid are admitted in sufficient amounts to maintain theethereal solution slightly acid. Quantities of 0.5 kg. of ester require3 to 5 days for the completion of the reaction, and an excess ofapproximately 30% of sodium is employed.Phase-rule considerations have been successfully applied to theproblem of the manufacture of ether, and it is shown that the systemH,S04-EtOH-H,O-Et,O-EtHSO, has three degrees of freedom.The state of equilibrium, with particular reference to ether,33 ispractically independent both of temperature and of sulphuric acidconcentration.A thermodynamic study of the conditions of thereaction enables results to be deduced which agree with experimentaland working experience. Using the Williamson method for thepreparation of pure ethyl ether, a yield of 80% may be obtained 34by condensing ethyl iodide with sodium ethoxide.The view that ethers are stable compounds, unacted upon bysodium, is confuted by a comprehensive study which has beeninstituted with the object of determining the relative tenacity withwhich dif€erent radicals are linked to the oxygen atom.35 Diethylether is decomposed by sodium a t 200-240" into ethylene, ethylalcohol, and probably also to ethane and hydrogen.The increasingorder of tenacity towards oxygen is represented by the series benzyl,ethyl, isoamyl, p-naphthyl, a-naphthyl , and phenyl. Exposure ofethyl ether to the air is known to confer oxidising properties on thesubstance, and three examples of ether peroxide formation havebeen noticed,36 and the products isolated and analysed. These arerepresented by propyl, n- butyl, and methylenediethyl ethers. I nother cases, owing to the higher boiling points of the ethers, isolationwas not possible, and aldehydes, esters, acids, and hydrogen peroxidewere formed.When the glycols, mixed with acetone, are heated in the presenceof sulphuric acid, their acetone compounds or isoproyylidene ethersare readily prepared. Examples are given of this reaction asconducted with ethylene glycol , propane- a p - diol , propane - ay- diol ,glycerol, and its monochlorohydrin. Exact physical data arerecorded3' for these and other analogous compounds, and theequilibrium constants of the reaction, acetone + d i o l e isopropyl-83 J.Desmaroux, Me'rn. Poudres, 1923, 20, 335; A., i, 484.84 W. B. S. Bishop, J . SOC. Chem. Ind., 1924, 43, 2 3 ~ ; A., i, 363.35 P. Schorigin, Ber., 1924, 57, [B], 1627; A., i, 1185; compare -4., 1923,86 A. M. Clover, J . Amer. Chem. SOC., 1924, 46, 419; A., i, 363.37 J. Boeseken and P. H. Hermans, Rec. trav. chin&., 1923, 42, 1104; A.,i, 207.i :267ORGANIC CHEMISTRY. 65idene ether + water, have been ascertained. It is shown that theglycols combine with the same facility with acetone as they dowith boric acid.Crystalline ethylglycerol triformin is readily prepared from ethylglycerol and 96% formic acid, whilst the mono-, di-, and tri-forminsare obtained by using the industrial 88% formic acid.38 By distillingthe mixture of the mono- and di-formins, p-ethylallyl formate andthe formin of vinylethylcarbinol were isolated.The paper containsa discussion of the mechanism of the reactions involved in thesynthesis of these alcohols and their formins from the three isomericmono- and di-formins.Other new derivatives of the glycol series are represented by thesynthesis of dicarbomethoxy glycol and the corresponding dicarb-ethoxy-compound. Of noteworthy interest are the substances ofsimilar type prepared by the condensation of glycerol with chloro-formic esters.39 Either two or three of the hydroxyl groups inglycerol may be protected by the introduction of the group -CO*OR,and a compound of the true carbonate type is represented by mono-C02Me*O*CH2*~H-O>co~ AC=,*O carbomethoxy glycerol carbonate,similar substitution product is obtained from ethyl tartrate.Oxidation of the acetyl ester of oleic alcohol with permanganateyielded both nonoic and acetylhydroxynonoic acids.Since thisester also gives, on reduction, the acetyl derivative of normaloctadecyl alcohol, the formula CH,*[ CH,] ,*CH:CH[CH,] ,*CH2*OH isestablished 40 for oleic alcohol and the alcohol is identical with thatobtained from ethyl oleate. A comparison of the physical constantsof the alcohol with those of elaidic alcohol is given; the stereoiso-merides may be sharply differentiated by their melting points, andshow no tendency to undergo interconversion.A simple and convenient process for the laboratory preparationof ethyl sulphate is reported.41 A mixture of alcohol and con-centrated sulphuric acid is allowcd to flow through a capillary tubeinto a heated vacuum flask containing anhydrous sodium sulphate.At 155-165"/2045 mm., distillation of ethyl sulphate takesplace, and a pure product is obtained by washing.Methyl ethylsulphate is prepared 42 by adding ethyl chlorosulphonate to a suspen-98 R. Delaby, Ann. Chim., 1923, [ix], 20, 106; A., 1923, i, 1171; oom-pare ibid., p. 993.39 C. F. Allpress and W.Maw, J., 1924, 125, 2259.40 Y. Toyama, Chem. Umschau, 1924, 31, 13; A., i, 267; compare A.,41 E. V. Lynn and H. A. Shoemaker, J . Amer. Chem. Xoc., 1924, 46, 999;1922, i, 895.A , , i, 605.T. K. Thayer, ibid., p. 1044; A., i, 604.REP.-VOL. XXI. D 66 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sion of sodium methoxide in dry ether. Using methyl ethyl sulphateas an alkylating agent, a yield of 56.7% of anisole was isolated fromphenol and also 13.4% of phenetole, as compared with the formationof 74.2% of anisole by the use of methyl sulphate. By a method 43of preparation analogous to that described above, propyl, isopropyl,n-butyl, and isoamyl ethyl sulphates have been obtained. Magnesiumphenyl bromide reacts with these ethereal salts, yielding ethyl-benzene.C a r b o h y d r a t e s .Photosynthesis.The problem of the mechanism of assimilation of carbon dioxideby the plant and its utilisation in carbohydrate synthesis is offundamental importance, but we are undoubtedly far from achievingany immediate solution.Little more than tentative theories canfor the moment be advanced, and it is unfortunate that thesehypotheses are sometimes unaccompanied by experimental evidence,or are based on the slenderest of premises. The claim to haveestablished the photochemical synthesis of sugars from formaldehydewas made two years ago and rested largely on qualitative or empiricaltests. Until recently,44 no analysis of this product was available,but it now appears that more than 80% of the material obtained bythis procedure consists of non-sugar compounds which containhydroxyl groups.45 Only a portion, which, on a favourable estimate,could not exceed 9-10yo of the total, had properties which resembledthose of a hexose and no identification with known dl-hexoses wasattempted.Ketoses and polysaccharides of the hexose type wereabsent. I n view of these facts, and considering also that ordinarysolutions of commercial formaldehyde contain many impurities,one feels that chemists may wish to be reassured that contact withtraces of well-known polymerising agents may not have beenprimarily responsible for the small proportion of hexoses whichwere apparently recognised. The most recent experimental methodrenders this attitude of caution still more necessary, since the useof calcium or magnesium carbonate is introduced into the process.It does not appear what is the effect, on these mineral carbonates,of light of the wave-lengths employed, but it is not inconceivablethat traces of potassium carbonate may have been formed by doubledecomposition with potassium salts in the solution.It has beenshown by Loew that O*lyo of potassium carbonate is effective inpolymerising formaldehyde to a sugar.43 L. Bert, C m p t . rend., 1924, 178, 1182; A , , i, 605.4 5 J. C. Irvine andG. V. Francis, ibid., p. 1019; A., i, 1826.E. C. C. Baly, J . I n d . Eng. Chem., 1924, 16, 1016, 1085ORGANIC CHEMISTRY. 67A claim has been made to the synthesis of formaldehyde, utilisinga process in which basic lead carbonate is distilled with hydrogenperoxide,*6 and, on the basis of this experiment, the author putsforward a hypothesis for the assimilation of carbon dioxide, accordingto which sunlight decomposes water with the formation of hydrogenand hydrogen peroxide : 2H,O -+ H,O, + H,.The carbon dioxideis then said to react with the hydrogen peroxide and hydrogen togive formaldehyde, oxygen, and water. The initial reaction onwhich this theory is based has been confirmed, but it is also shownthat the reduction of carbon dioxide proceeds, not from the hydrogenperoxide, but from the small amounts of organic preservatives, forexample, acetanilide, which are used to stabilise the commercialreagent,47 and thus the theory is devoid of foundation.A more promising approach to the problem is indicated in theplan of examining the processes involved in carbon dioxide assimil-ation by a consideration of each stage separately. The first step inthe photosynthesis is probably the absorption of carbon dioxide bysome material of the plant.This stage may involve the additiveformation of a definite series of compounds, and may be followed bya second stage in which the combined carbon dioxide, for example,an organic carbonate, undergoes reduction. Whether this stageis immediately succeeded by the appearance of formaldehyde assuch or in its " activated " or its hydrated state, is more thandoubtful. The manner in which the reduced carbon dioxide isutilised in the synthesis of a carbohydrate is again to be regarded asanother or third stage.Taking the first of these stages, it is now shown that dried andpowdered leaves, which are afterwards moistened, are able to absorbcarbon dioxide from the atmosphere in the dark.48 Helianthusleaves treated in this way absorbed as much as 4.59 mg.of carbondioxide for each gram of the dried leaf. The chemical agent respons-ible for this absorption in the dried leaf may be partly extractedwith cold alcohol, with cold water which has been saturated withether, and, to a smaller extent, with water alone; but the extractedmaterial does not possess a capacity for absorption equal to that ofwhich the leaf has been deprived, except in the case of the extractfrom aqueous ether. The absorptive capacity of the leaf is destroyedby heat.It is considered that the leaf of the plant absorbs carbondioxide by a mechanism resembling that by which the blood ofmammals serves to free the tissues from this gas. The major46 T. Thunberg, 2. phpihd. Chem., 1923, 106, 306; A., 1923, i, 1271.4' A. Bach and M. Monosson, Ber., 1924,57, [B], 735; A., i, 612; compare4 8 H. A. Spoehr and J. M. McGeo, Science, 1924, 69, 613; A., i, 1392.A., 1923, i, 1271.D68 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.portion of the carbon dioxide may be absorbed by proteins in theleaf, leading from this primary union to asymmetric synthesis ofcmbohydrates in the chlorophyllous plant.This function, ascribed to proteins, of uniting with carbon dioxideis known to be shared by chl~rophyll,~~ which has similarly beenregarded by Willstatter as participating in the initial mechanism.Furthermore, it has recently been shown that sugars are able toform definite carbonates, many of the synthetic derivatives of whichhave been isolated as crystalline compounds. The suggestion istherefore made that sugars,5o in common with other plant products,may share in the function of combining with carbon dioxide in theleaf, giving definite additive compounds of the nature of acid ornormal carbonates (I and 11), the former possibly existing as salts.These primary carbonates may quickly undergo reduction and appearas an orthoformic acid derivative (111) or a formaldehyde derivative(IV), as illustrated by the scheme :-(111.) (IV.)The compounds (111) and (IV) would yield, respectively, formicacid and formaldehyde on hydrolysis.The type of dioxymethylenelinking represented in (IV) occurs freely in natural products, and thereverse process of passing from the grouping (IV) to that of (11) isalready understood. This tentative suggestion receives somekind of support from the circumstance that a primitive form of carbo-hydrate has been isolatcd from the cabbage leaf having the con-stitution (V).This compound may represent a hydrolysis product of the dioxy-methylene derivative (VI) of a hydrated glycollaldehyde, or may,as the authors suggestY5l be a condensat'ion product of the latter withformaldehyde.It is unlikely that any of these theories contains the whole truth,but research along such lines should lead to some substantialprogress.49 R, Willstlitter and A.Stoll, Ber., 1017, 50, 1'791; A., 1918, i, 307;ibid., p. 243.66 C. F. Allpress and W. N. Haworth, J., 1924, 125, 1223.b1 H. W. Buston and S. B. Schryver, Biochem. J., 1923, 17, 470; A.,1923, i, 1062ORGANIC CHEMISTRY. 69A theoretical paper, in which much of the earlier experimentalwork on this subject is reviewed, also advances a new hypothesis,aaccording to which the primary process of assimilation is a photo-autoxidation consisting in the formation of a lipoid peroxide spar-ingly soluble in water. The second process is the formation of analbumin-carbon dioxide complex, and this is followed by the inter-action of both these products with water, whereby oxygen is releasedand the carbohydrate may be reduced by hydrogen peroxide(Wislicenus), or, alternatively, an albumin-carbon peroxide isformed, through which reduction to formic acid and formaldehydeoccurs.The fourth process is the recombination of oxygen with thelipoid oxide to regenerate the peroxide. This occurs in the presenceof light in chlorophyll-bearing cells and the cyclic process is repeated,the lipoid peroxide functioning as a photochemical motor. Chloro-phyll appears not to take a part in the assimilation process beyondthat of the promotion of the photo-autoxidation of the lipoid.The controversial nature of this problem is indicated by severalother papers contributing alternative theories or conclusions. 53Further experiments serve to confirm the modern view that sugarsare the first members of the carbohydrate group to be synthesisedby the plant.54 Probably the sugar initially formed is sucrose,which is transformed into monoses and finally into starch, inulin,or cellulose.55 The opinion that monoses are the f i s t sugars to beproduced has, however, its adherents, whilst others prefer t o regardstarch as an early product in the photosynthetic process.Theinteresting observation is made that plane-polarised light greatlyaccelerates the hydrolysis of starch by diastase,56 and photomicro-graphs illustrating this process accompany the paper,JIo 12 osaccharides.The fructose penta-acetates present certain optical anomalies ;the 6- and p-forms of the hexa-acetates of d-a-mannoheptose havebeen prepared, and a third variety, possessing probably a differentoside-ring structure, is now reported.Fluoro- and bromo-tetra-acetylfructoses have been obtained as crystalline substances,57 and68 Wo. Ostmald, Kolloid-Z., 1923, 33, 356; A., i, 250.63 J. Peklo, Chem. News, 1924, 129, 90; A., i, 1015; F. SVeigert, 2.physikal. Chent., 1923, 106, 313; 1924, 109, 79; A., 1923, i, 1271; 1924i, 922; T. Sabalitschka and H. Riesenberg, Biochern. Z., 1924, 144, 545, 651 ;A,, i, 475; H. Coupin, Compt. rend., 1924, 178, 1572; A., i, 808.64 E. C. Miller, J . Agric. Em., 1924, 27, 785; A., i, 1021.6 6 T. Weevers, Proc. I<. Akad. TYetensch. Amsterdam, 1924, 27, 46; A,,i, 810.E. C. C. Baly and E. E. Semmens, Proc.Roy. SOC., 1924, [ B ] , 97, 250.6T D. H. Brauns, J . Amer. Chem. Soc., 1923, 45, 2381; A., 1924, i, 265;C. S. Hudson, ibid., 1924, 46, 477; A . , i. 372; C. S. Hudson and K. P.Monroe, ibid., p.-979; A., i, 61770 BNNITAL REPORTS ON THE PROGRESS 0%' CHEMISTRY.also the fluoro-, chloro-, and iodo-triacetyl derivatives of Z-arabinose.The differences in their specific rotations are approximately pro-portional to the differences in the atomic diameters of the halogenatoms present in each.58 Striking changes are introduced in therotatory power of sugars in presence of concentrated hydrochloricacid a t low temperatures, and a paper recording these results andoffering explanations for this behaviour is contributed. 59Much attention has recently been directed to the sugar derivativesknown as the acetone compounds, which were originally describedby E. Fischer.Variations in the methods of preparation aredescribed, and several new compounds have been isolated. Differ-ences of opinion exist as to the constitution of glucose diacetone.Levene and Meyer 6o have methylated this substance and isolatedthe same monomethyl glucose as that described by Irvine andHogg,61 who regarded it as the 6-methyl glucose. The formerauthors have, however, ascribed to this derivative the constitutionof 3-methyl glucose, and base their contention on its ability to givea monomethyl saccharolactone on oxidation. The latter productgives rise to 3-methyl d-glucuronic acid on reduction and not tothe Z-form. The same conclusion as to the structure of glucosediacetone is drawn independently by other authors62 from thestudy of its hydrazino-substitution derivative, and an analogousformula is allocated to fructose diacetone.This has the effect ofgiving glucose diacetone a butylene-oxide structure (I) and fructosediacetone an amylene-oxide structure (11), which is contrary to theview usually held.The many anomalies that have been mentioned obviously requirevery careful reinvestigation. Fructose p-diacetone has been pre-pared, both from sucrose and inulin, and also from the a-diacetone.68 D. H. Brauns, J . Amer. Chem. SOC., 1924, 46, 1484; A., i, 837.68 LBszl6 Zechmeister, 2. physikal. Chem., 1922, 103, 316; A., 1923, i, 183.60 P. A. Levene and G. M. Meyer, J .Biol. Chem., 1923, 57, 317, 319;1924, 60, 173; A., i, 14, 944; 0. Svanberg and S. W. Bergman, Arkiv Kemi,A1h9 Qeol., 1924, 9, 1; A., i, 1285.'1 J. C. Irvine and T. P. Hogg, J . , 1914, 105, 1386.a2 K. Freudenberg and Ralph M. Hixon, Ber., 1923, 58, [B], 2119; A,,1923, i, 1179; K. Freudenberg and Arnold Doser, ibid., p. 1243; A., 1923,i, 652ORGANIC CHEMISTRY. 71The p-derivative is more resistant to hydrolysing agents than thea-compound, and for this reason the authors 63 consider that thetwo are structurally and not stereochemically related as supposedby Irvine and Garrett, and Irvine and Patter~on.6~ A curiousexample of the migration of the benzoyl group in benzoylglucosemonoacetone has been noticed, from which it is inferred that thebenzoyl group changes from position 6 to position 3 in the glucosechain.The author e5 suggests that such an explanation might applyto the case of methyl glucosediacetone, the wandering of the methylgroup providing a sufficient reason for the discordant results ofIrvine and Patterson and of Levene and Meyer.A new type of sugar compound has been synthesised 66 repre-sented by the sugar carbonates, derivatives of which are shown toexist in two forms : (A), the normal carbonates, and (B), the acidcarbonates :The type (A) resembles the acetone derivatives in structure, but bothtypes differ from the acetone compounds in being hydrolysed, notonly by dilute acids, but also with dilute alkalis even in the cold.Their preparation is conducted by acting on the sugars with chloro-formic esters in presence of (1) sodium hydroxide or (2) pyridine.Using these two methods in turn, crystalline derivatives of fructosewere isolated which are represented by the following formula? :CH,*O>C() 5!H2 O*CO,Ma FH,*O*CO,F, trq-0 rv*OH r$!*OH0 I YH*O>CO (I, $JH*O*CO,Me A t;H*O*CO,EtI YH.0 I $!H*O*CO,Mc I yH*O*CO,EtCH,*OCO,Me CH,*O-CO,Me CH,*O*CO,EtLYH LYH LYHCrystalline derivatives of galactose and of difructose were alsoobtained, as well as other similar compounds from glucose, sucrose,and mannitol.These compounds are unique in character and displayremarkable changes in rotation on keeping in the dark.The isolation of a-mannose is recorded for the f i s t time,67 andits rotation agrees with that calculated from theoretical consider-ations by Hudson.Its penta-acetate has been obtained, the proper-*a H. Ohle and I. Koller, Ber., 1924, 57, [B], 1566; A., i, 1168.64 J. C. Irvine and C. S. Garrett, J . , 1910, 97, 1277; J. C. Irvine and66 H. Ohle, Ber., 1924, 57, [Bl, 403; A., i, 497.6 6 C. F. Allpress and W. N. Haworth, J . , 1924, 125, 1223.67 P. A. Levene, J . Biol. Chem., 1923, 57, 320; 1924, 59, 120, 141; A , ,16, 615.J. Patterson, J., 1922, 121, 214672 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY.ties of which conform to those already determined from theoreticaconsiderations. By conducting the glucoside formation of mannoseunder conditions identical with those observed by E. Fischer in hispreparation of 7-methylglucoside, the analogous 7-methylmannosidehas been isolated and converted into the trimethyl and tetramethylderivatives.68 From the latter, tetramethyl y-mannose wasobtained as a crystalline substance having a dextrorotation. It issuggested that during the preparation of these compounds auto-condensation was observed, giving rise to a tetramethyl di-mannose.The constitution of the above derivative, tetramethyl 7-mannose,has not been determined by oxidation, but in view of the resultscommunicated by Levene and Meyer and described below,60 i t isprobable that this sugar is a 1 : 4- or a 1 : &oxide.From considerations such as those applied by J.Pryde in thecase of galactonolactone, it has been found that inannose gives riseto two different tetramethyl mannonolactones according as (a)mannonolactone is methylated or ( b ) tetramethyl mannose of theordinary form is oxidised to the lactone. Both products aredextrorotatory, and this is entirely in accord with Hudson's rule,although the authors themselves express some hesitation in applyingtheir results.They are to be interpreted in the sense that bothlactones have the oxide ring on the right of the chain, one of thembeing therefore a 1 : 4- (7) and the other rz 1 : 5-lactone (6).Already it has been demonstrated by J. Pryde 7O that ordinarytetramethyl galactose has an amylene-oxide st,ruciure giving a dex-trorotatory lactone on oxidation, and since this variety of galactosehas been isolated from lactose, melibiose, and raffinose, it is estab-lished that natural galactose occurs as a 1 : 5-oxide.A new struc-tural form of galactose has recently been prepared '1 as 7-methylgalactoside by the action of methyl-alcoholic hydrogen chloride inthe cold. It is readily transformed into a tetramethyl y-galactose,differing from the usual variety in that the equilibrium mixtureof a- and p-forms is lzvorotatory, whereas the normal compound ispronouncedly dextrorotatory.6 8 J. C. Irvine and W. Burt, J., 1924, 125, 1343.e0 P. A. Levene and G. RI. Meyer, J. Biol. Chem., 1924, 60, 167; A . , i, 944.70 J. Pryde, J., 1923, 123, 1808; 1924, 125, 620.7 1 W. N. Haworth, D. A. Ruell, and G. C. Westgarth, ibid., 1924,125, 2468ORGANIC CHEMISTRY, 73Oxidation of the new 7-isomeride leads to a tetramethyl gelac-tonolactone which is lsvorotatory, having a 1 : 4- or butylene-oxidering, and identical with that isolated by the methylation of thegalactonolactone obtained by oxidising free galactose itself.Having regard to the fact that Levene and Meyer have obtaineda new tetramethyl mannonolactone by methylation of mannono.lactone, and that the latter is considered by Hudson to be a truey-lactone, i.e., having its lactone ring in the 1 : 4-position, it wouldappear that the new 7-form of tetramethyl mannose isolated byIrvine and Burt should correspond to this lactone in structure,since the normal form of tetramethyl mannose gives a lactone havingquite different properties.The situation thus created would meanthat of the aldohexoses so far constitut,ionally examined with respectto their iiiternal oxide rings, galactose and mannose exist normallyas 1 : 5- or amylene-oxides.Glucose remains in doubt, although thestructure uniformly ascribed t o it is that of a 1 : 4- or butylene-oxide. But should glucose be drawn into the analogy with galactoseand mannose, then the fortuitous terminology of a 7-sugar willacquire a new and general meaning, in that such a compound willbe one that gives rise, on oxidation of its tetramethyl derivative,to a y-lactone as understood in the ordinary sense. Such a simpli-fication and interpretation of the nomenclature would be welcome.As the facts now stand, d-galactose in common with d-glucoseand d-mannose can exist as two structural varieties differing onlyin respect of the type of the oxide ring which they possess.Eachof these structural varieties gives rise to a- and p-stereo-modific-ations, and, in addition, the same number of isomerides will occurfor each of the three I-sugars. Consequently, eight modifications(four for the d- and four for the I-sugars) may be regarded as havingdefinitely been shown to be capable of existence for each of themonosaccharides glucose, mannose, and galactose. The formul-ation of these in the case of d-galactose may be representedas follows:H*C*OH HO*C*H HC*OH HO*C*HH - h A H - b d /+-OHH0.G.H HO*Y*H 0 0 HO*V*H 0 HO*(i.aHO*#*/ H O * y v 1 P - H 1 Y . HH*C H*Y H*V*OH H*C;*OH~H,*OH CH,*OH CH,*OH CH,*OHhTormal 3s orinal y-a-d-Galactose. y-j3-d-Galactose.a-d-galactose.,!?-d-galactose.It may now be regarded as established that all d-hexoses can existin four such modifications and fhe general chemistry of the sugarsshould be expanded to accommodate these facts. The simp16D74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.pentoses may similarly fall into line and, should this be the case,the total number of modifications of the aldo-hexoses becomes sixty-four, and of the pentoses, thirty-two. Small wonder indeed if, con-sidering this complexity, sugars do not respond easily to attemptsat their isolation in pure stereochemical forms. Hudson's endea-vours in this direction have been surprisingly successful, and suchcomments as may be made on minor inaccuracies in his applicationof the principle of optical superposition to the sugar group 72 mustallow for the considerable difficulties encountered.Studies of oxide-ring compounds, in which the oxygen bridgebears a resemblance to the structure of the sugars, continue toprovide valuable information. I n the past, the structure of a pro-pylene- or of an ethylene-oxide ring was allocated to y-sugars,but the properties of the compounds :r-0-1CH,*CH*CH,*CH*OAcr0-iR*CH-CR*OMehave been examined,73 and it is found that, in both cases, suchsubstances do not exist in the unimolecular condition but as poly-merides (except in the vapour state).The tendency to polymeris-ation is ascribed to the unsaturated affinity of the bridge oxygen,and is the greater the nearer the linked carbon atoms are situated.A compound of the butylene-oxide type (11) is described,(1.1 C, ,H,,*CH( OH)*CH,*CH,*CHOr - 0 1J - (11.) C,,H,,*CH*CH,*CH,*CH*OH,which is a dynamic isomeride of the aldehyde (I).Both thesecompounds are unimolecular,74 and it will be observed that theoxide-ring is of the butylene type. Other experiments which havebeen instituted should lead to further knowledge on this subject.75Fkcher's supposition that glycuronic acid is produced in theanimal organism by the oxidation of a glucose derivative in whichthe reducing group is protected, receives support from an investig-'* T. S. Patterson and C. Buchanan, J . , 1924,125, 2579.'3 M. Bergmann and E. Kann, AnnnZen, 1924, 438, 278; A., i, 1042;M. Bergmann and S.Ludewig, ibid., 1924, 436, 173; A., i, 490; compareBergmann and Miekeley, A., 1921, i, 763; Fischer, A., 1895, i, 437.74 Burckhardt Helferich and Hans Koster, Ber., 1923, 56, [B], 2088; A.,1923, i, 1177.76 H. Hibbert and J. A. Timm, J. Amer. Chem. SOC., 1923, 45, 2433;1924, 46, 1283; A., i, 16, 710; M. Bergmann, A. Miekeley, and F. Stather,Ber., 1923, 56, [B], 2255; A , , i, 5; H. Hibbert and R. R. Read, J . Amer.Chem. SOC., 1924, 46, 983; A., i, 613; P. A. Levene, J . Biol. Chem., 192459, 135; A., i, 615ORGANIC CHEMISTRY. 75ation 76 which describes the isolation of methyl glycuronide by oxid-ation of a-methylglucoside with sodium hypobromite, or Fenton’sreagent. Glucose, in presence of barium hypobromite, is found toundergo a stepwise oxidation, in which the chief products 77 aregluconic acid, p-ketogluconic acid, and arabonic acid.A quantitative study of the interaction of glucose and phenyl-hydrazine has confirmed Fischer’s speculation as to the fate of t h ethird molecule of the latter reagent during osazone formation.The equation representing the reduction of phenylhydrazine toaniline and ammonia is substantiated.I n the same paper,78valuable practical details for the preparation of osazones in optimumyield are described.Glucosides.The proof of the identity of the biose of amygdalin with gentio-biose was given last year; 79 this work has been repeated andconfirmed by independent workers, and is supported by otherevidence.80 A calculation of the rotations of two derivatives ofamygdalin, namely, isoamygdalin and prulaurasin, has shown 81that the biose chain of amygdalin has the same rotation value asthe chain of gentiobiose.This preliminary structural inquiry has now been followed bythe complete synthesis of amygdalin in accordance with the follow-ing scheme.82 The condensation of (I) ethyl dl-mandelate with(11) p-bromohepta-acetylgentiobiose was effected in the presenceof silver oxide, and gave rise to the crystalline et.hyl d + Z-hepta-acetylamygdalinate (111), a result which was communicated in anearlier paper by one of the authors.The latter ester was trans-formed into the amide (IV) by the action of ammonia dissolvedin methyl alcohol, and this reagent simultaneously removed theacetyl groups, forming d + Z-amygdalinamide.Acetylation of thisacid amide in pyridine restored the seven acetyl residues, andrecrystallisation of the product yielded two isomeric forms ofhepta-acetylamygdalinamide (IV) combined with 1 mol. of pyridine.One of these stereoisomeric forms was digested with phosphoricoxide in xylene solution and underwent dehydration from the acidamide to the nitrile, hepta-acetylamygdalin (V), which was la?vo-rotatory to the same degree as the acetylated product of natural76 K. Smoleliski, Roczniki Chemji, 1923, 3, 153; A., 1924, i, 10.i 7 M. Honig and F. Tempus, Ber., 1924, 57, [B], 787; A . , i, 712. ’* E. Knecht and F. P. Thompson, J., 1924, 125, 222.i* W. N. Haworth and B. Wylam, J., 1923, 123, 3120.81 C. S. Hudson, J . Amer. Chern.Xoc., 1924, 46, 483; A., i, 372.82 R. Campbell and W. N. Haworth, J., 1924, 125, 1337.G. ZemplBn, Bet-., 1924, 57, [B], 698.D* 76 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.amygdalin and with which it was shown t o be identical.acetylation with alcoholic ammonia gave natural amygdalin (VI),Ph-CH(OH)*CO,Et + B~*CH[CH*OA~],*CH*CH(OAC)*CH,>~ (11,)De-r - 0 1(1.1 CH,( OAc) *CH ( OAc) *CH*[ CH*O Ac],*CHL- 0--JPh*$JH*CO*NH2l /Ph*FH*CO,Et --+ ? w.1c26H3,0 170 (111.)C26H35017qH,*OH \~ H ~ O H ‘xp-1 f- YH*OH 1 YPh*$JH*CNVH*OH 9 c2 GH35OI 7This synthesis of amygdalin by R. Campbell and W. N. Haworthhas since been repeated independently by two other workers83and is substantiated at each stage by their results. There remainstherefore no reason for doubt that this important and historicnatural glucoside is d-mandelonitrile- p-gentiobioside.The conven-tion employed in referring amygdalin to the d-series is based onthe observation that laevorotatory mandelic acid is related to d-malicacid. Still further confirmation of this constitution is afforded bya modification of the first synthesis of amygdalin which is describedabove.The initial stage in this later synthesis by ZcmplCn and Kunz 84was achieved by the interaction of silver d-mandelate and aceto-bromogentiobiose, and the by-product from this condensationwas hexa-acetyl-d-amygdalo-lactone, which was converted byalcoholic ammonia into d-amygdalinamide, as compared with thecorresponding d + I compound isolated in the earlier synthesis.From this product synthetic amygdalin was obtained by a seriesof stages similar to those previously formulated.Three crystalline isomerides of tetra-acetyl d-methylmannosidehave now been is0lated.8~ One of these, prepared from P-d-mannosepentacetate having a laevorotation, possesses properties not generallycharacteristic of acetylated glucosidic derivatives of the sugars.Alkaline hydrolysis removes only three of the four acetyl radicals,68 R.Kuhn and H. Sobotka, Ber., 1924, 67, [B], 1767; A., i, 1330.84 G. Zemplh, Ber., 1924, 57, [B], 698; A,, i, 617; G. Zemplen andJ. K. Dale, J . Amer. Chem. Soc., 1924, 40, 1046; A., i, 615.A. Kunz, ibid., pp. 1194, 1357; A,, i, 975, 1225ORQAMC CHEMISTRY. 77although all four are eliminated by acid hydrolysis.The specificrotations of these three isomerides provide a close parallel to thethree crystalline tri-acetyl Z-methylrhamnosides and one of them isprobably a y-form. Glucosidic compounds of mannose with glycoland glycerol have been prepared by the synthetic agency ofa-d-mannosidase.86 A yield of 40% of pure @-methylglucoside fromthe reaction of glucose with methyl sulphate and alkali is reported.8'Experiments on the substitution of sugar residues for the glycerolgroup in olive oil have led to the production of a synthetic fatcontaining a methylglucoside residue. 88 This is formulated asbelow, where X represents the oleyl su bstituentCH( OMe)*CH( OH)*CH( OX)*CH*CH*CH,Condensation of allyl bromide with various carbohydrates inalkaline solution leads t o the isolation of tetra-ally1 or-methylglucoside, penta-ally1 sucrose, allyl dextrin, allyl inulin, the allylstarches, and allyl cellulose.89 A new method is also given for theextraction from plants of the pure glucosides which are soluble inwater,gO and some novel glucosides and galactosides of thiols aredescribed .91L 0 1 '0'Disaccharides.A synthesis of maltose has been effected by the action of yeastmaltase a t 37" on a 40% solution of dextrose.After fermentationof the residual glucose, crystalline maltose 92 was isolated from theportion of the residue soluble in alcohol, whereas the insolubleportion yielded slightly impure revertose in much smaller quantity.Croft Hill's experiments, it will be recalled, yielded chieff y revertose.Despite numerous attempts which have been made t o achievethe synthesis of sucrose, this biose successfully frustrates theendeavours of chemists.Although the precise structural form inwhich each of its two hexoses occurs is understood, the problem ofbringing together glucose and 7-fructose in such a manner as topresent the opportunity for their condensation to a disaccharidestill awaits solution. Meanwhile, further information is available 938 8 H. H6rissey and J. Cheymol, Compt. rend., 1924, 178, 1372; A., i, 801.87 H. H. Schlubach and K. Maurer, Ber., 1924, 57, [B], 1686; A., i, 1286.88'J. C. Irvine and H. S. Gilchrist, J., 1924, 125, 1.80 C. G. Tomecko and R. Adam, J . Amer. Chent.SOC., 1923, 45, 2698;90 S . Ghosh, J . Amer. PhQrm. A ~ ~ o c . , 1923, 12, 1080; A., 1924, i, 659.O1 E. Potel, Bull. SOC. chim., 1923, [iv], 33, 1459; A,, 1924, i, 15.92 H. Pringsheim and J. Leibowitz, Ber., 1924, 57, [B], 1576; A . , i , 1169.A . , 1924, i, 14.H. Colin and A. Chaudun, Bull. SOC. Chirn. b i d , 1924, 6, 625; A.,i. 128678 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.confirming the presence of the glucose constituent in the a-form,and a useful method is devised which may prove valuable in theisolation of sucrose in small quantities in admixture with glucoseand fructose. This depends on the observation 94 that the hexosesmay be oxidised with yellow mercuric oxide to the sugar acids, andin contact with calcium carbonate, the sucrose evades hydrolysisand may be recovered and purified from acetic acid.Sucrose is converted a t its melting point into a mixture of glucoseand lzvulosan, and if this mixture is heated further at 185'/15 mm.until 5% of its weight is lost, the product is isosaccharosan, whichcan also be obtained on heating a mixture of glucosan and laevulosan.The constitution 95 assigned to isosaccharosan is$?H,*OHrv-O--FH*CH( OH)*CH,*yH*OH 6 C;H*O*CH-- 0 CH,*OHI (iH*OHLCH*CH,*OHThe treatment of this compound with cold 5% ammonia is said tolead to isosucrose.By submitting lactose to similar conditions of heating, it is trans-formed into Iactosan, C1,H,,O1,,, an amorphous powder whichdissolves in water without displaying mutar~tation.~~ In reactionwith phenylhydrazine it yields lactosazone, and, on acetylation,gives lactose octa-acetate.Lactosan is said t o be 5-galactosido-glucosan; it is polymerised to the compound (C,,H,,0,,)4 byheating briefly a t 105" in presence of a trace of zinc chloride.A reinvestigation of compounds of the glucal type such as lactaland glucal itself, which were f i s t described by Fischer, has resultedin the better characterisation of these compounds and their pre-paration in a condition of greater purity. Several new trans-formations of a like kind have been effected, involving the isolationof isolactal and the conversion of lactal into 5-galactosido-mannose,which is apparently a new disaccha,ride, giving the same osazoneas lactose. The reduction of acetobromomaltose under conditionswhich produce glucal formation has led to the isolation of a deriv-ative of maltal, from which another disaccharide, said to be 6-gluco-sido-mannose, is obtained 97 on oxidation with perbenzoic acid.A , , i, 713.compare i, 499; A.Pictet and P. Stricker, a i d . , p. 708; A,, i, 1046.94 S. Komatsu and M. Tanimura, Illem. Coll. Sci. Kydtd, 1924, 7, 161;95 A. Pictet and N. Andrianoff, Helv. Chirn. Acta, 1924, 7 , 703; A . , i, 1045;'6 A. Pictet and M. M. Egan, aid., p. 295; A,. i, 499.07 M. Bergmann [and, in part, H. Schotte, E. Rennert, S. Ludewig, andM. Kobel], Annalen, 1923, 434, 79; A., i, 265ORGANIC CHEMISTRY. 79The need for an extension and standardisation of sugar nomen-clature is recognised, and a proposal is made that, in describingthe constitution of disaccharides, the hexose residue which retainsits free reducing group in the biose complex should end with thesuffix -ose, whilst the other hexose should be named as the glucosideconstituent.Thus, lactose becomes 5-galactosido-glucose. In thecase of a non-reducing disaccharide like sucrose, the use of the termglucosido-fructoside, or fructosido-glucoside, is advocated. Apply-ing this system to trisaccharides, raffinose is described as galactosido-(glucosido-fructoside). It is further suggested that the termsanhydro-sugar, anhydrobiose may be employed when the reducinggroup is not implicated in the anhydride formation. Should thereducing group be involved, however, it is considered preferableto speak of the compound as a monose-anhydride or a biose-anhydr-ide. The points of attachment of the internal oxide-ring may berepresented by placing the numerals in brackets.For example,the compound (I) shown below is designated 5-galactosido-mannose-anhydride [l : 41 [l : 21 2 3 4 6 r-- 0 1CH *CH CH (OH) CH *CH ( 0 * C 6H 0 5) CH,OH'0'( T: 1Questions have been raised as to the purity of the acetobromo-maltose obtained by Karrer's method, since the product gives ayield of only 30% of hepta-acetylmaltose. Pure acetobromo-maltose is best prepared 98 by allowing maltose to remain in contactwith acetyl bromide at 0" for 20 to 40 minutes. Material preparedby this method gives a yield of 70% of hepta-acetylmaltose onheating with acetic acid and sodium acetatePolysacchurides.Starch.-The investigation of the constitution of starch is seento depend increasingly on the application of biological methods.In those cases where definite progress has been achieved along theselines, greater attention has been directed to the homogeneity ofthe materials and of the enzymes, and especially to the adoptionof generally accepted standards by which the products of thereaction are characterised. One example may be quoted from thework of H.Pringsheim and his c~llaborators.~~ Starch hydrolysisH. Fischer and F. Kogl, Annalen, 1924, 436, 219; A., i, 498; compareE. and H. Fischer, A., 1910, i, 716; Karrer, A., 1921, i, 310, 313, 768.VB H. Pringsheim and K. Schmalz, Biochem. Z., 1923, 142, 108; A., i, 106;0.Holrnbergh, Ark. Kemi, Min., Geol., 1923, 8, No. 33, 1 ; A., i, 691 ; Biochem.Z., 1924, 145, 244; A., i, 69180 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.by the agency of maltase-free amylases is found to proceed beyondthe supposed limiting value of 70-78% of maltose formation, andas much as a 96% yield of the latter has been obtained. I n yeast,a complementary agent occurs which has the effect of pressing thehydrolysis of starch beyond the previously recognised limiting valueobtainable with amylases, such as those of the saliva and thepancreas. This complementary agent reactivates very markedlyold preparations of malt extract which have lost much of theiramylolytic power, and the accelerating agent is itself destroyed byboiling.Again, the methods of Ling and Nanji, commented on in lastyear’s Report, of distinguishing between the content- and integu-ment-materials of the starch granule have been freely recognised,and confirmation of their results is afforded in that these twomaterials are found to give rise respectively to a disaccharide anda trisaccharide.The amylose and amylopectin separated by Ling and Nanji’sprocedure .I were each subjected t o depolymerisation and gaverespectively a dihexosan (from amylose) and a trihexosan (fromamylopectin).2 Hitherto these compounds have been obtained asa mixture by submitting starch itself to depolymerisation byheating with glycerol.Further evidence of this differentiation between the inner andthe outer substances of the starch granule is adduced by theobservation that the former, amylose, is converted in the cold,with concentrated hydrochloric acid, into amylobiose, a newdisaccharide, whereas the outer material, amylopectin, yields underthis treatment a trisaccharide, amylotriose, which forms an o~azone.~On the other hand, as shown by Ling and Nanji, amylose is con-verted quantitatively into maltose under the influence of purifiedemulsin, or of amylases, but with amylopectin the reaction ceaseswhen 65% has been converted into maltose.The unattackedresidue of 35% in the amylopectin is recognised as trihexosan,which, since it can be further fermented with undialysed maltextract, appears not to be an essential component of the amylo-pectin molecule, but an “ accidental ” residue.Amylose is saidto occur independently in nature and is shown to be identical withisolichenin obtained from Iceland moss, since it gives rise to amylo-biose, whilst amylopectin is considered to be identical with glycogen,1 A. R. Ling and D. R. Nanji, J., 1923,123, 2666.2 H. Pringsheim and K. Wolfsohn, Ber., 1924, 57, [BJ, 887; A., i, 714;compare A., 1923, i, 899.H. Pringsheim [with A. Beiser, K. Wolfsohn, L. Leibowitz, and W.Kusenack], ibid., p. 1581; A., i, 1170; R. Kuhn, 2. phy8ioZ. Chern., 1924,135, 12; A , , i, 692ORGANIC CHEMISTRY. 81since the latter is transformed by cold concentrated hydrochloricacid into amylotriose.Amylobiose and amylotriose and also di- and tri-hexosan are allconverted quantitatively into maltose by malt diastase. Theyare not attacked by the a-glucosidic enzyme, maltase, or by thep-glucosidic enzyme of emulsin.The most surprising result hereinvolved is that of the quantitative formation of one biose, maltose,from a different biose and a triose. This is not to be regarded,however, as a reversible synthetic action of enzymes such as thatshown to lead to maltose from glucose, but is most readily explainedby the hypothesis that a glucose residue (I) readjusts the nature0-(1. ~ H C H (OH~CH ( OH)~HCH(OH)CH,L n -lof its oxide ring or is eliminated as a radical which unites withanother similar residue to yield maltose. The following con-stitutional forrnuh are proposed for amylobiose (11) and amylo-triose (HI)Amylobiose, the new disaccharide, is also obtained by the coldhydrochloric acid treatment of cx-t,etra-amylose or P-hexa-arnylo~e.~That p-hexa-amylose cannot be identical with triamylose is provedby the conversion of the former on exhaustive methylation into thecrystalline p-hexa(trimethylamylose), which, on hydrolysis, yieldsonly 2 : 3 : 6-trimethyl g l ~ c o s e .~Slightly divergent results are perhaps only to be expected a tthis early stage of so complex a problem, but a comparison of theproducts isolated from different preparations and by variousworkers would be greatly facilitated if all the available physicalconstants of the products were accurately determined and placedon record.has reported that the action of undialysedamyJaae solution on amylose leads to the isolation of a dihexosanH.Pringsheim and J. Leibowitz, Bey., 1924,67, [B], 884; A., i, 714; cbm-pare A., 1923, i, 899.J. C. Irvine, H. Pringsheim, and J. Macdonald, J., 1924, 125, 942.K. Sjoberg, Ber., 1924, 57, [BJ, 1251; A., i, 1169.Another worke82 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which is probably identical with that described above. It yieldsa diacetate, and also a tetramethyl derivative, from which 2 : 3-di-methyl glucose is obtained on hydrolysis. Under similar treatmentwith this ferment, amylopectin yielded a trihexosan, probablyidentical with that isolated by Pictet and his collaborators 7 byheating potato starch with glycerol.Amylopectins prepared from different starches differ in appear-ance, conductivity, viscosity, and in other properties of theiraqueous solutions, as well as in their phosphorus content andacidity, The amylopectins from underground storage organs asin the potato, arrowroot, and tapioca, are distinct from those fromseeds as in maize, rice, and wheat.These differences are maintainedeven in acid-treated starches. It is reported, however, that syntheticamylopectins prepared from different starches are closely analogous.*Glycogen.-H. Pringsheim identifies glycogen with the amylo-pectin constituent of starch, and the identical behaviour of starchand glycogen on methylation, as well as the similarity of themethylated hydrolysis products, bears out this hypothesis. Glycogenhas been exhaustively methylated with methyl sulphate in presenceof sodium hydroxide and yields a product containing 36.4% ofmethoxyl and having + 179.8" in chloroform, This correspondswith the introduction of two to three methyl groups into eachglucose residue.Either steric hindrance or physical conditionmilitates against further alkylation. Hydrolysis of this productwith methyl-alcoholic hydrogen chloride yielded the glucoside ofbutylene-oxidic 2 : 3 : 6-trimethyl glucose, ident'ical with a specimenisolated from starch, cellobiose, and cellulose. A second productof cleavage was a dimethyl glucose of the butylene-oxide type, andthis is possibly a 2 : 5-derivative.Pectins.-The jelly-making substance of fruits has long beenrecognised as a valuable domestic adjunct, and the discovery ofpectin in these juices was made many years ago by Braconnot. Thecombined investigations by Fremy, Scheibler, Herzfeld, Tollens, andothers served to establish the fact that the pectins are carbohydratederivatives possessing acid properties.Two more recent investig-ators, von Fellenberg and Ehrlich, have recognised the presencein pectins of methyl ester groups and galactose, and of the galactoseanalogue of glucuronic acid, namely, galacturonic acid, which is theintermediate oxidation product between galactose and mucic acid.7 A. Pictet and P. Stricker, Hdv. Chirn. Acta, 1924, 7, 932; A,, i, 1288;* M. Samec, M. Minaev, and N. Roniin, Koll. CJiern. Beihefte, 1924,19, 203;u A. K. Macbeth and J. Mackay, J., 1924, 135, 1513,A.Pictet and R. Salzmann, ibid., p. 934; A., i, 1288.A . , i , 923ORUANIC CHEMISTRY. 83On hydrolysis of pectins with alkali, methyl alcohol is eliminated,but isopropenyl groups may to some extent occupy the place of themethyl groups, especially in apple pectin, and so also may metallicresidues.Ehrlich describes lo the naturally occurring pectin of plants asthe " calcium magnesium salt of a complex anhydro-arabino-galactose-methoxyltetragalactonic acid," some units of which areloosely bound. Pectic acid is obtained by dissolving out the araban,and by eliminating the calcium and magnesium with dilute acids,The product still contains methoxyl residues and is spoken of asan ester-acid, but is regarded by Ehrlich as essentially a galactose-galacturonic acid, an equimolecular union of galactose and galact-uronic acid analogous to the paired glucuronic acids which occurin the animal body.At least three pectin substances have been definitely recognised :pectose (or protopectin), the parent substance ; soluble pectin(or pectin); and pectic acid.The existence of protopectin hasrecently been questioned by Tutin. Of thesc three forms, proto-pectin is said to occur in succulent root vegetables and unripefruits; soluble pectin in ripe fruits; and pectic acid in over-ripefruits and vegetables. Progressive hydrolysis, either by enzymesor dilute acids, converts protopectin into soluble pectin and thisinto pectic acid. A similar degradation of pectins occurs in theprocesses of the natural or chemical retting of flax and hemp fibres.When fruit juices containing pectins are boiled with sugar andorganic acids, the viscous solution sets to a jelly on cooling. Pro-longed boiling, however, destroys this property, probably owing tothe formation of pectic acid.Jelly formation is therefore a propertyneither of fully methoxylated pectin nor of pectic acid, but of thepartly hydrolysed intermediate products.The dried pulp of sugar-beet contains about 25% of pectin andconstitutes an immense source of the raw material. The pectinof sugar-beet contains a glucuronic acid residue, and it is suggestedthat this acid is the intermediate stage in the formation of pentosesfrom hexoses in nature.ll From the sugar-beet residues the crudepectin is obtained by treatment with dilute acids, and alcoholprecipitates from this a dry, white powder, which dissolves in waterto give solutions many times more viscous than those of gum arabic.It does not reduce Fehling's solution, but gives the naphtharesorcinoltest for glucuronic acid.The latter acid is isolated after treatmentof the purified pectin with 1% sulphuric acid a t 130".10 A useful &.sum6 and a bibliography of the subject are given by W. H.l1 K. Smoleriski, Roczniki Chemji, 1923, 3, 86; A , , 1924, i, 16.Dore, Ind. Eng. Chern., 1924, 16, 104284 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Two substances are recognised in the crude pectin. The portioninsoluble in alcohol, or purified pectin, which contains d-galacturonicacid in considerable amount ; and the alcohol-soluble portion,which is a polysaccharide consisting almost entirely of Z-arabinoseresidues.The latter, araban, is lsvorotatory ; it readily undergoeshydrolysis and becomes dextrorotatory as the Z-arabinose is formed.The original pectin of the sugar-beet is probably insoluble in water,dissolving, however, as hydrolysis proceeds, with the formationof the above two constituents. This hydrolytic process is found tooccur rapidly in the presence of N/200-mineral acid. A constitu-tional formula for pectin has been suggested :and it is considered probable that these substances occur in theplant as the result of oxidation of hexosans such as starch.Lichenin.-The material known as reserve cellulose, or lichenin,occurs freely in the lichens and bears a somewhat near relationshipto cellulose on the one hand, and to a constituent of starch on theother.It occurs in Iceland moss, from which it may be extractedwith boiling water, and is a white powder, dissolving to a clearcolloidal solution in hot water. Acetolysis proceeds much moreslowly than with cellulose, and the yield of octa-acetylcellobioseis smaller.12 A soluble lichenin is recognised which is attacked moreresdily than the ordinary, sparingly soluble form mentioned above.The similarity of lichenin to cellulose is said to be such as to connotelittle essential constitutional difference. The enzyme or enzymesoccurring in the alimentary canal of the edible snail (Helix pomatia)has been provisionally called Zichenase, since it ferments solublelichenin to glucose in a few hours.Sparingly soluble lichenin isalso vigorously attacked a t first, but the rate is soon retarded.Cotton cellulose is attacked by lichenase, but sparingly and incom-pletely on account of its insolubility. The fermentation is said todepend on the dispersity of the substrate, the course of the reactionwith soluble lichenin being a t first unimolecular until the disappear-ance of the most highly dispersed particles.Lichenase is closely related to cytase, but the latter containsenzymes which attack not only reserve celluloses, but also mannanl2 P. Karrer, B. Joos, and M. Staub, Helv. Chirn. Acta, 1923, 6, 800; A.,1923, i, 1182; P. Karrer, M. Staub, and J. Staub, z%id., 1924, 7, 169; A.,i, 373ORGANIC CHEMISTRY. a5and galactan.A method of preparing lichenase free from thenumerous enzymes which accompany it in the edible snail is given.13Exhaustive methylation of lichenin with methyl sulphate leads toa product containing 41.9y0 of methoxyl compared with the usualmaximum of 42--43y0 in the case of cotton cellulose. Methylatedlichenin l4 dissolves in water to a colloidal solution, and resembles,in some respects, methylated hydrocellulose more than methylatedcellulose, but, unlike the former, it does not depress the freezingpoint of water. Hydrolysis with 1 yo methylalcoholic hydrogenchloride gives rise to trimethyl- and dimethyl-methylglucosides insimilar proportions to those obtained from fully methylated cellulose.Since lichenin may be hydrolysed to glucose by malt extractand also yields octa-acetylcellobiose on acetolysis, it ought to bepossible to show that malt extract is capable of hydrolysing licheninfirst to cellobiose by the agency of a lichenase, and t,hen to glucoseby the agency of cellobiase; that is, to prove that lichenase andcellobiase are both present in malt extract.This speculation hasbeen verified.15 An attenuated malt extract obtained by keepingfor three months, hydrolysed lichenin only to cellobiose, which wasidentified by its rotatory and reducing power and by the isolationof its osazone. Cellobiase evidently disappears from malt extractby long storage.Lignin.-The processes which are operative in the plant leadingto the slow oxidation of starch t o pectins as t,he fruit matures,possibly find a parallel in other kinds of vegetation in the slowconversion of cellulose into ligiiin.An explanation of the formationof coal may also be furnished by the close study of the exceptionalproperties of lignin substances. Coal-like products are obtainedwith surprising rapidity by exposure, a t relatively low temperatures,of wood tissue or of cellulose to the action of salts which are foundin sea water. At 95", magnesium chloride produces a markedchange and hydrochloric acid is eliminated. l6The work of Bray and Andrews l7 on the chemical processesoccurring during the bacterial decay of wood may, however, becited in support of the hypothesis that the origin of coal is notchiefly traceable to the cellulose of dead vegetation but to thel3 P.Karrer, M. Staub, A. Weinhagen, and B. Joos, Helv. Chim. Acta,1923, 8, 144; A., i, 471.l4 P. Karrer and K. Nishida, ibid., p. 363; A., i, 501; P. Karrer andM. Staub, ibid., p. 928; A., i, 1288.l5 P. Karrer, M. Staub, and B. Joos, &id., p. 164; A , , i, 471; P. Karrerand M. Staub, ibid., p. 916; A., i, 1382; ibid., i, 471; H. Pringsheim andJ. Leibowitz, 2. phy8iOE. Chem., 1923, 131, 262; A., 1924, i, 233.l6 C. G. Schwalbe and R. Schepp, Ber., 1924, 67, [Bj, 319; A . , i, 377.l7 M. W. Bray and T. M. Andrews, I d . Eng. Chm., 1924,16,13786 ANNUAL REPORTS ON THE PROGRESS OF CHE~STRY.lignin. These authors have shown that in the space of 3 years thecellulose content of wood had decreased to 6%, whereas the ligninhad practically resisted bacterial action.Schwalbe's experiments,showing that powerful dehydrating agents act on cellulose to form asubstance resembling coal, are held to be invalid as an argument insupport of his hypothesis, because the conditions of the experimentdiffered greatly from those prevailing in nature. The view 18 whichis preferred is that dead vegetation would be rapidly attacked bybacterial decay with consequent destruction of the cellulose, andthat the ligiiin which survives this attack is converted into coal.The above experiments with solutions of mineral chlorides both onlignin- and cellulose-containing substances indicate, however, thatthe truth lies probably somewhere between these two points ofview.Ligilin is far less stable than cellulose when heated with aqueousalkali.It is observed that, whilst a t 300" cellulose undergoescomplete dissolution, partly decomposing with production of muchcarbon dioxide, lignin is decomposed by 9.5N-potassium hydroxideat 300" with the formation of phenols and adipic acid, and by10N-sodium hydroxide a t 250" with the production of succinic andoxalic acids. Autoxidation of lignin occurs in presence of sodiumhydroxide, yielding humic acids as well as the above, possibly alsoisophthalic acid, and, in addition, acetic, formic, and carbonic acids.Cellulose is attacked to a lesser degree and similar differences areobserved in the comparative oxidation of lignin and cellulose underpressure ; the latter tends to form aliphatic acids, whilst ligninproduces, in addition, aromatic acids.Its ready nitration is inharmony with the supposed phenolic structure of lignin. The t a robtained by destructive distillation of lignin appears to containno optically active compounds in its aqueous extracts, whereaslaevoglucosan is isolated from cellulose under parallel conditions.It is therefore clear that the polysaccharide character of cellulose islargely modified in lignin. The cyclosaccharides or cycloses in thelatter may be regarded as intermediate links capable of unitingpartly with true carbohydrates and directly with each other.20The presence of hydroaromatic rings in lignin, and its, as yet undeter-mined, position between the aliphatic and aromatic compounds,provide a stimulus to speculation and investigation.The methylether of inositol is a constituent of the sap of certain conifers, andfrom inositol are obta,inable several of t'he aromatic and aliphaticderivatives detected in the cleavage products of lignin.18 F. Fischer, BrennstoJJ-Chem., 1924, 5, 132; A., i, 715.19 F. Fischer and H. Tropsch, Ber., 1923, 56, [B], 2418; A., 1924, i, 14s;20 E. Strupp, Cehlosechem., 1924, 5, 6; A., i, 376.E. Heuser and F. HerrmaM, CdZdosechem., 1924, 5, 1 ; A., i, 376ORGANIC CHEMISTRY. 87From flax lignin, by digestion with dilute alkali, a homogeneousproduct (I) has been isolated,2f and this passes on acetylation into(11) and by methylation with methyl sulphate into the methyllignin (111).(1-1 C,o~,o06(OH)5(OMe),~CHO; (11.1 C,,H,,O,(OM~),(OAC)~~~~~;(111.) C4,H3,0,(0H),(0Me),*CH0.The presence of one aldehyde group in lignin is deduced from theaction of Fehling’s solution and of phenylhydrazine.The product(11) is insoluble in cold, dilute alkali, but is readily hydrolysed byboiling water, indicating that the acidic properties of the ligninare to be ascribed to phenolic hydroxyl groups. The product (111)is insoluble in alkali hydroxide and resistant to hydrolysis andacetylation, pointing to some difference between the remaininghydroxyl groups in lignin and those in its derivatives. Cold nitricacid introduces three nitro-groups into lignin, giving the red com-pound, C42H3,022N3, which contains one methoxyl group andbehaves as an aromatic compound. Into this, six acetyl groupscan be admitted, giving acetylnitrolignin.I n the absence of sunlight, chlorine and bromine substitutionoccur with lignin, giving chlorolignin, C,oH2,0,C11,( OMe)2( OH),*CHO,and the corresponding bromolignin, both of which are soluble inalkali and have suffered partial demethylation.They are notaffected by hot nitric acid and are only partially dehalogenated byboiling with sodium hydroxide. The remaining halogen atoms arethus attached to aromatic nuclei. The halogenated and acetylatedlignins, as well as the acetylnitrolignins, are hydrolysed withdifTering degrees of readiness.Comparison of these results with those of Cross and Bevan,Klason, and of Bechmann and Liesche, shows that the lignins fromjute, flax and pine are not identical, but that those from flax andwinter rye straw are closely related.The process of digesting spruce wood with a 7% solution ofsulphurous acid, free from sulphuric acid, is shown to be attendedby a lower degree of sulphonation than in the case of the digestionwith calcium hydrogen sulphite.The process is accompanied,however, by a pronounced degradation of the cellulose.22 Ligno-sulphonic acid has been separated 23 from the products and containsthe characteristic groups represented in the formulaC21H1502(S03H)(OH)2(CH,*OH)(CH*OH)(CHO)(OMe)2.Its reactions show that it consists almost entirely of a substance21 W. J. Powell and H. Whittaker, J., 1924, 125, 357.22 C. F. Cross and A.Engelst,ad, J . SOC. Chem. Tnd., 1924, 43, 2 5 3 ~ ; A.,23 C. U0ri.e und L. Hall, ibid., p. 257; A., i, 1048.i, 104888 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of Klason's or-type (aldehydic) of lignoiie. With dilute nitric acidoxidation of the constituent groups occurs with the following result :This nitro-compound, on reduction, shows no resemblance to thearomatic type, and the behaviour of the substance recalls that ofsome unsaturated terpenes of the cholesterol series. The C,,nucleus of lignorie is thus probably hydroaromatic in character,consisting of a reduced ring complex resembling the reducedbenzophenanthrene hydrocarbon formulated by Schrauth.=C,,H,,OS(~o,>,(oH>,(~0)(CO,H),(OMe~.Cellulose.The name cellulose is applied to many nearly-related productsdiffering in origin and sometimes also in properties and chemicalconstitution.Cotton cellulose may be regarded as the pure standardproduct, and the problem has arisen as to the homogeneity of manyother varieties.Spruce wood appears to contain cellulose of two types,25 oneresistant to a solution of sodium hydrogen sulphite containing1.83% of hydrochloric acid and heated to 98", and the other resistantto a similar solution containing only 0.73% of hydrochloric acid.The type of cellulose which is unaffected by the stronger acid solu-tion corresponds to crystalline cellulose, and the other type toamorphous cellulose. It is proposed to define cellulose as thesubstance corresponding to the latter type, namely, that which isresistant only to the weaker acid, since cotton cellulose is attackedby the stronger acid solution.To return to the occurrence of the two types in spruce wood, itis observed that in the natural condition in the plant cell thecrystalline cellulose protects the amorphous from the action of thestronger acid, until the cells are mechanically ruptured by rasping,when the protection ceases.The degree of protection afforded bythe crystalline variety varies in different species of wood, and isless complete in beech wood than in spruce.The difference in behaviour exhibited by cotton cellulose and byesparto cellulose in contact with highly concentrated hydrochloricacid is very marked. Whilst from the former a 700/, yield of glucosecould be isolated in the form of a derivative, the esparto cellulosesolution became highly coloured and evolved quantities of furfural.26The amount of furfuraldehyde produced corresponds with thepresence of 18.5% of pentosan in the dry esparto cellulose.Thispentosan can be completely extracted from cellulose of this originW. Schrauth, -2. anyew. Chem., 1923, 36, 149; A., 1023, .i, 443.2s P. mason, Papier.Fabr., 1924, 22, 373; A., i, 1289.26 E. L. Hi& and D. R. Morrison, J., 1923, 123, 3226ORGA?XIO CHEMISTRY. 89by boiling with 12% sodium hydroxide and is identified as xylan,which readily hydrolyses to xylose. The remaining 81-50/, of theesparto cellulose is identical with cotton cellulose,27 since it gives,on acetylation (acetolysis), cellobiose octa-acetate, and, on methyl-ation, the same trimethyl derivative as cotton cellulose.2 : 3 : 6-Tri-methyl glucose was isolated by the hydrolysis of each of thesemethyl celluloses.Degradation of cotton cellulose with dilute sulphuric acid (5%)begins to be appreciable at 70" and hydrocellulose is one of thcproducts. The formation and chemical behaviour of this substancehave been closely studied.28Cellulose, in cuprammonium solutions, undergoes no hydrolyticdecomposition. The copper is present as an optically activecomplex anion and the kation is an ammine. The maximumrotation is attained immediately on solution of the cellulose. Thesolutions have been examined from the point of view of massaction, and the molecular complexity of the dissolved cellulosehas been determined.Equations illustrating the formation ofcellulose-cuprammonium solutions have been completelyas also those for similar solutions of other carbchydrates.A further study of the acetyl derivatives of cellulose has beenundertaken with the object of determining the molecular weightof the carbohydrate, since i t is established that the formation ofwhat is known as cellulose triacetate A does not change the poly-merised condition of the original substance. Pure unchangedcellulose can, indeed, be recovered from this compound,Dried cotton cellulose does not react with dry acetyl chloride,but if 4---5y0 of moisture is present and the reactants are shakenin contact for 4 days a t 17-20', a 92% yield of crude triacetate Ais obtained, and treat'ment with chloroform leads to the pure com-pound, which is a colourless powder.Variation of these con-ditions gives rise to cleavage by-products in considerable quantities,such as cellodextriiiacetate, and derivatives of the disaccharide,cellobiose. Some of the cellulose acetates previously described ashomogeneous contain these and other impurities. Cellulose tri-acetate A melts a t 270--2$5", and is laevorotatory in chloroformand dextrorotatory in glacial acetic acid. In phenol, its molecularweight has the value 2380-3350. Hydrolysis to the regenerated,unchanged cellulose is effected with cold A'-methyl-alcoholic sodiumhydroxide. The product, cellulose A, is a white powder having*' J. C. Irvine and E.L. Hirst, J., 1924, 125, 15.H. Gault and B. C. Mukerji, Compt. Tend., 1924, 179, 402; A., i , 1068.** K. Hess, W. Weltzien, and E. Messmer, Annalen, 1923, 435, 1 ; A.,1924, i, 142ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.[alD -12.4" in ZN-sodium hydroxide. It is shown by X-rayanalysis to be crystalline, and its rotatory power in cuprammoniumsolutions establishes its structural identity with the original cottoncellulose used.If acetic anhydride mixed with acetyl chloride be used inthe acetylation of cellulose, an acetate is obtained which, ondeacetylation, gives a regenerated cellulose less soluble in alkalithan cellulose A. The by-product previously mentioned as occur-ring frequently, namely, cellodextrinacetate, is more soluble in theusual solvents than cellulose triacetate A, and gives a molecularweight value in phenol of 1260-1480. By deacetylation, dextrinis formed as a white powder, which reduces Fehling's solution.The experimental procedure leading to the methylation of spar-ingly soluble polysaccharides by the agency of methyl sulphatehas, in the past, involved the use of concentrated alkali in contactwith the carbohydrate. These conditions differ materially fromthose which are usually applied to the water-soluble sugars, themethylation of which is usually conducted in an almost neutralmedium until nearly the whole of the methyl groups have beenintroduced.Doubt has now been expressed as to the value of the experi-mental results30 obtained by Denham and Woodhouse and byIrvine and Hirst by the methylation of cellulose in st,rong solutionsof alkali.It is suggested that the alkali has a definite action oncellulose a t the temperature of methylation. Cellulose A, as ispointed out by Hess and his co-workers, is so altered by warmingwith dilute alkali that it reduces Fehling's solution and is no longerprecipitated on acidification. If this change occurred during theprocess of methylation, the result would be masked owing to therapid methylation of the exposed reducing group. Hydratedbarium hydroxide, however, has no effect on cellulose A, andmethylations conducted by substituting this reagent for alkalihydroxide may be assumed to proceed without the introduction ofstructural changes. The product obtained in this way was ayellow glass (OMe = 30.40%), insoluble in, and unaffected by,alkali, and, on further methylation with sodium hydroxide andmethyl sulphate, gave trimethyl cellulose A (OMe = 42.43%).Theresults obtained from the hydrolysis of this product will be awaitedwith interest.Acetylated cellulose A is partly converted by acetyl bromide,containing hydrogen bromide, into acetobromocellobiose, butaccompanying this usual product there is a new acetobromo-glucose. This new glucose derivative is converted into acetobromo-30 J., 1913, 103, 1735; 1921, 119, 77; 1923, 123, 518ORGANIC CHEMISTRY. 91cellobiose by the further action of acetyl bromide and hydrogenbromide. Deacetylation of the new variety of acet,obromoglucoseproceeds normally with alcoholic ammonia, but with acids thebromine is eliminated and celloglucosan 'is obtained, which can beconverted quantitatively into a-methylglucoside.These resultsindicate that cellulose can be transformed into a derivative ofglucose (the new acetobromoglucose) without the intermediateformation of cellobiose, and therefore it is considered no longernecessary to regard the latter as a genuine cleavage product of cellu-lose. Cellobiose is consequently assumed to be a product of rever-sion synthesis from glucose, and structural formula assigned tocellulose on the basis of cellobiose are, in the opinion of Hess, ofdoubtful validity.I n their survey of this work occupying 144 pages in the Annalen,Hess and his collaborators conclude that cotton cellulose is builtup from glucose anhydride units which are associated, not con-densed or polymerised.According to the earlier workers onmethylated cellulose, 2 : 3 : 6-trimethyl glucose is the sole productof cleavage, and assuming that no structural changes are involvedin their method of procedure, the cellulose unit would ber . 01L 0 _ICH*CH( OH)*CH( OH)*CH*CH*CH,*OHAt variance with this formula are the results already quoted as tothe action of hydrogen bromide on cellulose triacetate A. Hess,Weltzien, and Messmer prefer to represent cellulose as the formulaI t s dissolution in cuprammonium solution, which effects saturationof the partial valencies involved in the association of the celluloseunits, may be expressed as giving rise to the ion :,The above celIulose formula is held to explain the amphotericcharacter of this carbohydrate and also its behaviour towardsneutral salts such as zinc chloride.Natural cotton cellulose maycontain as its crystal unit, as deduced from X-ray analysis, fourC6H,,0, residues associated together.W. N. HAWORTH92 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.PART II.-HOMOCYCLIC DIVISION.Stereoisomerism. Mohr's Theory of Strainless Rings.EVIDENCE has recently been brought forward to show that thestrain in large polymethylene rings (e.g., the cycloheptane ring)may be relieved by the twisting of the ring into a multiplanarconfiguration.l The theory of strainless configurations was firstadvanced by H. Sachse.2 I n the simplest case to which it can beapplied, the cyclohexane ring, there are two strainless forms (forconvenience termed " cis " and " trans' ), each of which can beconsidered to occupy three planes :(cis) k l (trans)cycZoHexane derivatives, however, do not show the isomerism towhich these formulz should give rise, and from this it must beinferred either that this relief of strain does not take place, orthat strainless forms represent phases only of the contortions ofthe molecule.The latter alternative seems the more probable, asthe two forms are interconvertible by a process involving simul-taneous rotations (with slight strain) around the single bonds.E. Mohr 3 observed, however, that the fusion of two strainlesscyclohexane rings to give decahydronaphthalene could take plaein two ways giving rise to isomerides the existence of which hadpreviously been considered impossible.One contains two six-membered rings united by the cis-valencies of their common carbonatoms; the second, and more remarkable, contains a union by(CiU) (trans)trans-valencies. There is no question here of interconversion bytwisting or simultaneous rotation around the bonds, for, althoughby this process variations of each formula can be produced, the tworings lock one another in such a way as to prevent interconversionof the types : the formulz, in fact, represent stable isomeridea.1 Ann. Reports, 1923, 20, 103.2 Ber., 1890, 23, 1363; A . , 1890, ii, 1386.J . pr. Chem., 1918, [ii], 98, 315ORaANI(3 CHEMISTRY.93The f i s t experimental evidence in favour of this theory W ~ E Iobtained by A. Windaus, W. Huckel, and G. Reverey,4 who showedthat the trans- as well as the cis-form of hexahydrohomophthakacid gives a stable anhydride :(cis) (trans)Huckel then discovered that the two decahyclro- @-naphthols(which had been investigated by Mascarelli and Recusani,6 and wereevidently regarded by them as ordinary geometrical isomeridesrelated like tropine and $-tropine), on oxidation with chromicacid, gave different ketones. This isof the ordinary theory of plane rings,means of Mobr's theory :unaccountable on the basisbut is readily explained byCH, CH,CH2 /\ H-c /\COc"2\/ V C H 2IH-b 1CH, CH,CH, CH,/\ /\coCH, CH,The two ketones, on oxidation with permanganate, yield, as theyshould, the ordinary cis- and trans-forms, respectively, of l-carb-oxyeyclohexane-2-propionic acid :C0,H CO,K ,-I, CH,*CH,*CO,H /a\iH \S/l \--/IH CH,*CH2*C02Hand on reduction by Clemmensen's method give two decahydro-naphthalenea differing by 8" in their boiling points.' An examin-ation of their physical constants indicated that the contradictoryboiling points and densities previously recorded for decahydro-naphthalene, prepared by reduction of naphthalene, were due tothe occurrence of mixtures of cis- and trans-forms.This has beenproved in the case of technical decahydronaphthalene by W. Borsche4 Bw., 1923, 56, [BJ, 95; A., 1923, i, 220.Nach. K. Gea. Wiw. Gottiwen, 1923, 43; A,, 1924, i, 31.6 Atti R.Acead. Lincei, 1911, 20 (v), 2, 223; A . , 1912, i, 761.7 Compare also F. Eisenlohr and R. Polenske, Ber., 1924, 57, [BJ, 1639;A., i, 129194 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and E. Lange,* who first converted Huckel's cis- and trans-deca-hydronaphthalenes into their respective carboxylic acids :H, H2and then identified both of these in the mixture of acids producedin the same way from the technical hydrocarbon. R. Willstatterand F. Seitz further established the fact that, whereas decahydro-naphthalene prepared by means of platinum black consists essen-tially of the cis-hydrocarbon, the reduction of naphthalene withnickel and hydrogen at 160-162" yielded principally the trans-isomeride.So far, then, as concerns decahydronaphthalene and p-keto-decahydronaphthalene, Mohr's theory may be regarded as estab-lished, but there are many obvious consequences which still awaitexperimental verification. Thus there should be four stereo-isomeric a- or p-monosubstitution products of decahydronaphthalene(all optically resolvable) :but hitherto no more than two have been obtained, Again, thereshould be five inactive stereoisomeric, fully hydrogenated anthra-cenes, two of which should be optically resolvable, and sixteenstereoisomeric a- or P-monosubstitution products (all resolvable) ;also six isomeric fully hydrogenated phenanthrenes, of which fourshould be resolvable, and sixteen of each of the five structurallydifferent monosubstitution products (all resolvable),-significantconsequences for workers in the field of the higher terpenes, thestructures of which are now known to be based on the hydro-naphthalene and hydrophenanthrene nuclei (p. 99).cycloButane Derivatives.-A more conventional, but neverthelessdifficult, stereochemical problem has been worked out in connexionwith cyclobufane derivatives of type (I).Compounds of this classshould exist in five geometrically isomeric forms. The first memberof the group to have its five forms isolated and their configurations* Annalen, 1923, 434, 219; A., 1924, i, 32.Ber., 1924, 57, [B], 683; A., i, 628ORGANIC CHEMISTRY. 95assigned was the acid ( I I ) . l O This year, the investigation of a second,and very interesting, case has been completed, namely, that oftruxillic acid (111), which is formed by the self-addition of cinnamicacid.XYH-FHY CO,H*YH-~H*CH,*CO,H Co,H*$!H-~H*C,H,YCH-HX CO,H*CH,*CH-CH*CO,H C,H,*CH-cH*C02HThe five truxillic acids (distinguished by the prefixes a-, y-, 7-or peri-, epi-, and E - ) are all known, and their structural identityfollows from the ready conversion of the a-acid into all the others.llct-acid -+ anhydride of 7-acid and anhydride of y-acid(1.) (11- 1 (111.)heat(Ac,O)' I H,O (Ac20)' I H,O I+ y-acid I+n.o\&jy wcidhot Ac 0 E*O epi-acid -$ anhydride of e-acid e €-acidAc30If, now, the five possible structures be examined it will be seenthat they can be divided into two groups :Those with phenyls in the trans-position, formulae (1) and (e),should lead to optically resolvable anilic acids ; whilst those withcis-phenyls should give non-resolvable anilic acids.Applying thiscriterion, it is found that the a- and 7-acids belong to the first class,and the 7-, epi-, and €-acids to the second.l2 Consideration of therelative stability and ease of anhydride formation of the membersof each group (compare the above interconversion scheme) thensuffices for the definite allocation of the formulae : (1) = a, (2) = y,(3) = 7, ( 4 ) = epi, and ( 5 ) = e.lo C. K. Ingold, E. A. Perren, and J. F. Thorpe, J., 1922, 121, 1765.11 H. Stobbe and F. Zschoch, Ber., 1923, 56, [B], 676; A., 1923, i, 337.R. Stoermer and F. Bacher, ibid., 1924, 57, [B], 15; A., i, 400.l2 R. Stoermer, ibid., 1923, 56, [B], 1683; A., 1923, i, 92996 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.In addition to the truxillic acids a series of structural isomeridestermed truxinic acids, having the formulaC,H,*~H--$?H*CO,HC,H,*CH-GH-CO,Hare produced from cinnamic acid by additive ring synthesis; l3but the stereochemical problem here involved is less advanced, as,of the six possible forms, four only (the p-, 8-, 5-, and neo-acids)have so far been isolated.The Mechanism of the Wagner Rearrangement.Two types of view have been expressed with regard to themechanism of the rearrangement which so frequently accompaniesthe dehydration of tert.-alkyl carbinols.One hypothesis, upheldnotably by Ruzicka,l4 postulates the closure and the fission in adifferent direction of a cyclopropane ring.The essential feature ofthis theory is that the hydrocarbon radical supplying the hydrogeneliminated as water (R1 in the formulae which follow) is the radicalwhich undergoes transference to the adjoining carbon :(R1= rlH, R2 = r2H)The second hypothesis has been proposed in several forms, involvingpartial valencies,l5 free valencies,l6 or i011~,l7 but the commonrequirement of all of them is that the radical supplying the hydrogeneliminated as water is not the one transferred. For example,using the partial valency hypothesis, the reaction may be formulatedthus :I I R2-C-CH,\R3liR,-C- CH*''..R3,."Hr1 \OHII R2-C-GH2/R3'13 M. Reimer (J. Amer. Clhern. SOC., 1924, 46, 783; A . , i , 612) has shownthat the conversion of methyl styrylglyoxylate, CHPh:CHCO*CO,Me, intocyclobutane derivatives by self-addition also occurs in both possible ways,and the same is probably true of the self-addition of coumarin (A.W. K. doJong, Rec. trav. chim., 1924, 43, 316; A,, i, (344).l4 L. Ruzicka and Fr. Liebl, Helv. Chirn. Acta, 1923, 6, 267; A., 1923,i, 475.l5 R. Robinson, Mem. Manchester Phil. Soc., 1920, 64, No. 4, 1.l* M. Tiffeneau, Compt. rend., 1906, 143, 684; A . , 1906, i, 39; J. Bredt,Wiillner-Peatechrift, Leipzig, 1905, 123. .l7 H. Meerwein and R. Wortmann, Annalen, 1924, M, 190; A,, i, 188ORGANIC CHEMISTRY. 97Three reasons have been given against the former view.(a) I n cases in which the intermediate ring compound can beprepared it is often found to be too stable to undergo the fissionreaction under the conditions in which this is supposed to occur.18( b ) Instances are known in which optical activity is retained duringthe transformation, although the postulated intermediate ringcompound is structurally incapable of optical activity.19( c ) Although the structure of the product does not usuallydifferentiate between the mechanisms when water is eliminated,the analogous change in which bromine is eliminated by the useof a metal can only be interpreted by means of the secondmechanism .20As to (a)and (b), it might be said that considerations relating to isolatedintermediate compounds do not apply to these substances in the‘‘ nascent ” condition; and as to ( c ) it might be doubted whetherthe change in which bromine is eliminated is really analogous.Butto most chemists, probably, these objections would appear weak,and on the whole the available evidence may be regarded astending against the cycloid theory, although it does not finallydisprove it.Turning to the second hypothesis, it should first be observedthat the various forms in which it has been advanced may not beso mutually antagonistic as might perhaps appear. From theinvestigation of triarylmethyls it is known (compare p. 115)that the production of free valencies and ions may be merelydifferent manifestations of the same structural condition, thiscondition depending on a peculiar distribution of residual affinities.It therefore seems possible that, although in the great majority ofcases the mutual attraction of the two parts of the moleculeultimately eliminated may cause an altered distribution of affinityand the consequent migration of a group, there may be specialstructures in which the natural distribution of affinity (apart fromany tendency towards an elimination) is such as to loosen one ofthe attached groups, and give rise, under suitable conditions, toisomeric change dependent on the formation of a free valency oran ion.It has recently been found that the Wagner change may occurwithout any elimination, and in cases in which there is little likeli-hood of an addition of water and its subsequent splitting off.ItOf course there are replies to all these arguments.18 H. Meerwein and K. van Emster, Ber., 1920, 53, [R], 1815; A., 1920,l9 Idem, ibid.20 C.K. Ingold, J . , 1923, 128, 1706.i, 855.BEP.-VOL XXI. 98 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.is significant that instances of this kind have been found amongststructures in which there is independent evidence of the possibilityof ionisation, and that the changes are facilitated by the use of adissociating solvent. This suggests that the explanation is to besought in the ionic hypothesis, but at the same time the fact thatthis type of isomeric change appears to be con$ned to the structuresin which there is evidence of ability to ionise seems to indicate thatthe ionic hypothesis should be applied only to such cases.The ionic hypothesis may be formulated thus :The cases which most clearly favour it belong to the camphaneseries, certain of the halogen compounds of which closely resemblein many of their reactions the triarymethyl halides, and to thisextent are similar to acyl, rather than to alkyl, halides.Thusbornyl chloride (V) and camphene hydrochloride (IV) readily yieldethers on treatment with alcohols,21 just as does triphenylmethylchloride. Since triphenylmethyl chloride is known to be measur-ably ionised in solvents with a sufficiently high dielectric constant,the possibility of incipient ionisation in bornyl chloride and incamphene hydrochloride must be admitted; and it is found,22 aswould be expected from the ionic hypothesis, that the isomericchange (IV) -+ (V) readily takes place, in the presence, for instance,CH2-CH-CMe, CH,-CH-CMe,CH, 1 CMeClI(N.) I CH2( --3 h, bH2Le tV.I\CH/ LAof cold alcoholic hydrochloric acid.Again 2 : 2-dichlorocamphane(VI) changes into a-chlorocamphene hydrochloride (VII) (which,under the conditions employed, loses hydrogen chloride, givinga-chlorocamphene) on treatment with potassium acetate in phenolsolution : 8(VII. )21 H. Meerwein and L. GBrard, Annalen, 1924, 435, 174; A., i, 186.Idem, &id. 23 H. Meerwein and R. Wortmwm, loc. citORGANIC CHEMISTRY. 99It should be said that Meerwein and Wortmaim do not adoptthe view that the ionic theory is peculiarly applicable to thesehalogen camphanes: they apply their theory to all cases of theWagner rearrangement, even those in which there is elimination.I n their opinion the elimination of wa,ter in the dehydration of aterl.-alkyl carbinol is not the " driving force " of the rearrangement,but is a, subsequent occurrence; the real migration occurring withinthe ion remaining after the hydroxyl group has been removed byelectrolytic dissociation.The function of the acid used to bringabout the change is to esterify the hydroxyl group, it being assumedthat the ester so produced would be ionisable as shown below(X = acid radical) :According to this theory, therefore, the rearrangements of thehalogen camphanes correspond with Wagner dehydrations ofcarbinols by means of hydrochloric acid, and the fact that these" hydrochloric esters " are capable of isomeric change is regardedas justifying the general hypothesis.Now the " hydrochloricesters," (VIII) and (IX), of pinacolin and pinacol are related toone another precisely like thc chlorocamphanes, (VI) and (VII), andmight be expected, therefore, to be as readily interconvertible.CH3(=.ICH3 IcH3-17cc' CMeClThe change cannot be effected in either direction,% however, andthis, taken in conjunction with the fact that there is here noindepen'dent evidence of tendency to ionise, is perhaps an indicationthat special structural conditions are necessary for rearrangementby the ionic mechanism.The Structure of the Sesquiterpenes.Although many of the sesquiterpenes have long been known,attempts to achieve order in their chemistry have, until recently,met with little success.With the work of Ruzicka and hiscolleagues, however, this new field has been entered. Structuraltypes have been established, and the constitutions of some membersof each of them exactly determined; more important still, order24 H. Meerwein and R. Wortmann, loc. cit.E100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.can be seen amongst the facts. Rational sesquiterpene chemistrymay now be said to have definitely entered on its career; and, asfuture progress may be expected to be rapid, a summary of thepresent position seems desirable.More than 300 naturally occurring sesquiterpene products havebeen described, but all these are not equally well characterised, andit is possible that some a,re identical or contain identical con-stituents, and that others are stereoisomeric forms (p.94) of thesame structural individual. Amongst the best known membersoE the series are .Cadinene, from oil of cubebs.Caryophyllene, from carnation oil and copaiba oil.Santalene, from sandal-wood oil.Selinene, from celery-seed oil.Zingiberene, from ginger oil.In addition to these, there are numerous related alcohols, such asCalamenol, C,,H,,O, from calamus-root oil.Cadinol, C15H2,0, from galbanum oil.Eudesmol, C15H2,0, from eucalyptus oil.Farnesol, C15N2,0, from musk-seed oil and acacia-blossom oil.The first of these compounds to have its structure established wasthe open-chain alcohol, famesol, which was proved by M. Kersch-b a ~ m , ~ 5 in 1913, to have the structureCMe,:CH*CH2*CH2*CMe:CH*CH,-CH2*CMe:CH*CH,*OH.Most that is known about the hydrocarbons themselves, however,has been the outcome of the work carried out by Ruzicka and hiscollaborators since 192 1, Semmler’s earlier conclusions haviagundergone considerable modification a t the hands of theseinvestigators.0. Wallach first suggested (1587) that the naphthalene, nucleusmight be the basis of sesquiterpene structure,26 and F.W. Semmler 27(1903) developed this idea. Both investigators based their specu-lations on the principle of division into isoprene units, ,>C-C-C,it principle to which there has hitherto been no established exceptionamongst terpenes.Until 1922, however, no definite naphthalene derivative had beenidentified amongst the degradation products of sesquiterpenes.But A.Vesterberg’s proof (1903) that abietic acid (a diterpene acid,C20H&,02), on heating with sulphur, yielded retene 28 (l-methyl-20 Annden, 1887, 239, 49.C35 Ber., 1913, 46, 1732; A., 1913, i, 739.a7 Ber., 1903, 30, 1038. Ibid., p. 4200; A., 1904, i, 151ORGANIC CHEMISTRY. 1017-isopropylphenanthrene) might have been regarded as suggestingthe following regularity :Terpenes, Cl0, based on benzene nucleus.Sesquiterpenes, C15, based on naphthalene nucleus.Diterpenes, C20, based on phenanthrene nucleus.Using Vesterberg’s sulphur method, Ruzicka and his collaboratorsdehydrogenated a number of sesquiterpenes and related alcohols.Most of them,, including cadinene, zingiberine, and calamenol,gave the same hydrocarbon, Cl5HI8, which was evidently a naphtha-lene derivative, and was termed “ ~adalene.”~g Adopting thehypothesis that farnesol might be related to cadinene as the simpleopen-chain terpene-alcohol geraniol is to dipentene, the followingprobable structure for cadalene was reached :p 3C 7%CH2 /\CH/CH2\ /\/\ y\/- I ,) CH,.CHJ\ CH,*OH y H 2flH \CH//c’cH3CH/\ C/\ CH, CH3 CH, CH,Cadalene was then synthesised, and this hypothesis confirmed.30As to the positions of the two double linkings present in cadinene,reduction experiments prove that they are not conjugated, and bycombining this result with the evidence from ozonolysis, it is shownthat cadinene may be represented by either or both of the followingformulae (the formation of the carbon framework from isopreneunits is also depicted) : 31(Pamesol.) (Cadalene. )FH3 p 3 FH3C: CH, C CH, C CH,/\/\yH2 VH flH\/\//\/\/\\/\//\CH, CH,YH, CH YH,$! CH/\ \\ //\CH,flH VHCH,CH, CCH, CH CHC*CH3 CH bHC*CH3.C;H CH,c: CH CHCH,CH, CH, CH, CH,( 3 mols. Isoprene.) (Ccadinene. )J. Meyer, and M. Mingazzini, &id., 1922, 5, 345; A., 1922, i, 560.Reprh, 1922, 19, 118.2* L. Ruzicka, Helv. Chim. Acta, 1921, 4, 505; A., 1921, i, 573; L. Ruzicka,30 L. Ruzicka and F. C. Seidel, ibid., 1922, 5, 369; A., 1922, i, 562; Ann.81 L. Ruzicka and M. Stoll, aid., 1924, 7, 84; A., i, 302102 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.Cadinol, the related alcohol, C,,H,,O, which on dehydration givescadinene, is probably a mixture of two individuals correspondingwith the two formuls for cadinene (the presence of a 7-cadinol issuspected) : 3,9H3 $333CH CH, CH CH,/\ /\ /\ /\FH, CH GH $332 7%\/ \/ \/ \/CH, bH CGH, CH, CH CCH3V*OH CH ?*OH CH,CH CH/\CH, CH,(a-Cadinol.)/\CH, CH3(8- Cadinol.)It is not necessary that a sesquiterpene should contsin the com-plete double ring system in order to give a naphthalene derivativeon dehydrogenation. Zingiberine, for instance, is a trebly un-saturated monocyclic sesquiterpene with a 5-carbon side chain,which becomes closed during dehydrogenation. Farnesol ondehydration yields a quadruply unsaturated open-chain sesqui-terpene, farnesene,33 which is very similar to a sesquiterpene inJavanese citronella oil.Thus not only dicyclic sesquiterpenes, butalso monocyclic and open-chain sesquiterpenes, may be regardedas closely related to the naphthalene hydrocarbon cadalene.It has been remarked (p. 101) that the farnesol chain, whichconsists of three isoprene residues joined end to end, can be coiledup to produce the cadinene framework, just as the geraniol chain,composed of two isoprene residues, can be made to give thedipentene skeleton. A hypothesis as to the types of dicyclicsesquiterpene structure likely to be encountered may be formedif it is observed that, whilst the geraniol chain can give onlyone methylisopropylhydrobenzene, the farnesol chain can yieldthree (and only three) dimethylisopropylhydronaphthalene nuclei,namely the cadinene skeleton (A) and two .others (B and C) : 3432 L.Ruzicka and M. Stoll, Helv. CJzim. Acta, 1924, 7, 94; A., i, 302.33 L. Ruzickrt, ibid., 1923, 6, 492; A., 1923, i, 691./\ /\ 1appear to be excluded by the rule that, if any alternative is available, thechain will not close in such a way as to have 1 : I-dialkyl groups attachedto an unbridged cyclohoxane nucleus (compare C. K. Ingold, J., 1921, 114,953). It can easily be seen that this condition necessitates the presence of anisopropyl group in any terpene or sesquiterpene structure which does not containa bridged six-rnembered ring, and limits the number of types as statedORGANIC CHEMISTRY. 103(Type B.1It is of great interest, therefore,-<"' I- \/I\/ /\( T y p e Q.1that although most of thesesquiterpenes and their alcohols that have been-examined yieldcadalene (Type A) on.dehydrogenation, a second series has beendiscovered, which yields a different naphthe!er_e hydrocarbon,called " eudalene," 35 related to Type B.CH,CH3(Eudsslene. )P 6- (nnt,ural)Selinene.The sesquiterpene selinene and the alcohol eudesmol belong tothe class which yields eudalene. The position of the double linkingin selinene has been determined (principally by ozonolysis), andproof has been given of the position of the methyl group lost inthe conversion into eudalene.36 The precise structure of eudesmoldoes not yet appear to have been ascertained.The third group of dicyclic sesquiterpenes to be expected on theabove hypothesis, those containing the framework (C), should yield3 : 7-dimethylnaphthalene on dehydrogenation, but no member ofthis class has yet been discovered.It may be added that much work is in progress on the diterpenes.This subject, however, does not yet appear to be in EL conditionupon which it would be useful to report.[i], 119; Ann.Reports, 1923, 20, 100.55 L. Ruzicka and M. Sfoll, Helv. Chim. Ada, 1922, 5, 923; A . , 1923,96 Idem, ibid., 1923, 6, 864; A., 1923, i, 1216104 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.The Eiject of Position on the Physical Properties of BenzeneDerivatives.It will be of interest to everyone that the researches on theabove subject, published since 1915, by Sidgwick and hiscollaborators have now reached a point a t which it has beenfound possible, not only to co-ordinate the facts, but also to offera reasoned theory capable of accounting simply for a considerablesection of them.37 The theory is based fundamentally on Werner’stheory of co-ordination (and the electronic interpretation thereof),and it makes particular use of the idea of co-ordinated hydrogen.It is probable that the publication of this paper marks a new stagein the correlation of physical properties with constitution, becauseit brings a new point of view to the aid of that difficult study,to which little imaginative insight has hitherto been applied.The properties studied were solubility and volatility, and a t theoutset a clear distinction was drawn between properties possessedby a substance in the solid state-that is, properties largely deter-mined by crystalline forces-and those found in the liquid state,in which the only structural unit is the molecule.It is in theliquid state that we may expect to find the simplest relation betweenphysical constants and structure, and accordingly the wholeinvestigation relates to the liquid state.Broadly speaking, benzene derivatives may be divided into“ normal ’’ and “ abnormal,” the term “ abnormality ” meaningthat the isomerides (0-, m-, and p - ) differ widely in their volatilityand solubility, properties which, in the majority of benzene deriv-atives, are little influenced by the position of the substituents.The structural conditions necessary for the appearance of abnor-mality are, (1) that the molecule contain two “ active or alterablesubstituents” (OH, NH,, CO,H, CHO, NO,, C1, as opposed to“unalterable substituents ” such as the alkyls), (2) that of thesetwo groups a t least one must be OH, NH,, substituted NH,, orC0,H.The existence of two different panels of groups shows thattwo functions have to be fulfilled in the production of abnormality :one group makes the compound sensitive, and the other acts onthat sensitivity, like the chromophore and auxochrome groups ina dye. The type of variation from the normal depends primarilyon the group belonging to the second list, that is, whether thecompound is a phenol, an amine, or an acid. These are consideredin turn.I n the case of phenols (containing as a second substituent one ofthe groups in the first list) the abnormality consists in the factfourteen earlier papers are given in the original.37 N.V. Sidgwick and R. K. Callow, J . , 1924, 125, 527. References tORGANIC CHEMISTRY. 105that whilst the meta- and para-compounds resemble one anotheras closely as do normal isomerides, the ortho-compounds differmarkedly from them (a) in being more volatile, ( b ) in being lessmiscible with water, (c) in being more miscible with benzene. Theseproperties are characteristic of " non-polar " as opposed to " polar "substances, the adjectives being used in a wide sense to distinguishgroups of properties characteristic in an especial . degree of non-hydroxylic as opposed to hydroxylic compounds. In other words,the ortho-compounds are far less polar than the meta- and para-.The polar characteristic natural to a phenol is, then, suppressed byan " active " group in the ortho-position much as if the hydroxylichydrogen had been replaced by methyl. The theory advanced isthat the hydroxylic hydrogen becomes attached by a co-ordinatelinking to some atom of the second group as in formulz (X)-(XIII) ,in which an arrow pointing to the hydrogen atom is used for theco-ordinate bond which restrains its polar functions :0 X(X- 1 (XI.1 (XII. ) (XIII.)Formula (X) depicts the supposed cause of abnormality in thenitrophenols, and formula (XI) that due to the carboxyl, carb-ethoxyl, and aldehydo-groups. The chelate rings contained inthese two formuh are of the most stable type known-6-memberedrings with two conjugated double linkings.In the case of theother active groups (halogens, OH, OAlk, and possibly NH,), thepresence of the rather less stable, five-membered chelate ring mustbe assumed (formulae XI1 and XIII), and accordingly, the abnor-mality, although present, is in these cases less marked. Chelatecompounds always tend to be non-polar (compare the metal acetyl-acetones), and the ring structure explains why o-nitrophenol cannotform compounds with aniline, p-toluidine, benzamide, and acet-amide, whereas m- and p-nitrophenols can; and why, if the phenolhas active substibuents in both 0- and p-positions (e.g., op-dinitro-phenol), the influence of the ortho-group predominates and thecompound is non-polar.As to the mechanism of the formation of the co-ordinate linkand the chelate ring, it is to be noted that the atom to which thehydrogen atom becomes joined is always one which may be assumedto be a seat of residual affinity.In the case of univalent chlorine,bivalent oxygen, or tervalent nitrogen, the corresponding elec-tronic picture is that of an atom which possesses several unsharedE106 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.electrons in its octet, and is able to use a pair of them as a ‘‘ bond ”to attract the hydrogen nucleus. This is the view adopted by theauthors, and the extension of their work on phenols will be awaitedwith interest, because certain crucial experiments to reveal themechanism more closely would obviously be possible if the listsof active and inactive groups were longer than they are a t present.The behaviour of the two other main groups, the substitutedanilines and substituted benzoic acids, is quite different fromthat of the phenols, and more complicated-too complicated,perhaps, to be usefully reported on a t the present time.Althoughthe data display regularities >and have been grouped together,they are not such that the theory of co-ordinated hydrogen canbe straightforwardly applied, and no generally applicable theoryhas yet been advanced.Reactions of Aromatic Compounds.Ortho- and Para-additions to the Benzene Ring.-The view that theproperties of all benzene derivatives could be traced back to purelyaliphatic types, if the aliphatic types themselves and the successivestages in the “ evolution ” of aromatic types from them were betterknown, is nowhere more simply illustrated than in the case of thephenols, which present perfect analogies with the keto-enol andketo-cyclol types in the aliphatic series.Although Baeyerfavourod the centric formula during his earlier researches on benzenestructure, he concluded in his final paper (despite the difficulty ofunderstanding, a t that time, the diminished unsaturation of thecomponent parts of Kekul6’s structure) that certain phenols un-doubtedly possessed the Kekul6 formula, and, consequently, keto-enol tautomeric ~haracter.~* Further, it has been shown that thegeneral reactions of the phenols, like halogenation and alkylation,as well as peculiarly “ aromatic’’ reactions, such as Tiemann andReimer’s, conform to well-known aliphatic keto-enol and keto-cyclol types.39 It is of interest to note that in developing hisbromine-titration method for estimating enols K.Meyer employedThe closing remark inwhich Baeyer epitomises tho whole of his experience with the henzene problem,is as incisive today as when i t was written. “The benzene nucleus,” hesays, ‘‘ exists in two forms which may be regarded as tautomeric in the sensethat every individual derivative has a definite constitution; this view bestexplains the facts, and gains enhanced probability when it is considered thatthe ortho- and pm-linking in phenanthrene and anthracene, respectively,have almost identical properties and are similar to the ‘ breakable ’ linkingsin the molecule of benzene.”39 C.K. Ingold, J., 1922,122, 1133; compare also W. Fuchs and B. Elsner,Ber., 1924, 57, [B], 1225; A., i, 960.38 Annalen, 1892, 269, 188; A,, 1892, 62, 1214ORGANIC CHEMISTRY. 107P-naphthol as a typical enol to take up the excess of bromine.According to his general theory of the mechanism, the first stepmust be 1 : 2-addition to the Kekuli? double linking, and a bromo-ketone must intervene :CH CHBrCHBr CBrNow, just as in the case of t’he Tiemann-Reimer reaction, it shouldbe possible t o obtain evidence of the correctness of the abovemechanism by the introduction of a “ blocking group,” which,by preventing the final tautomeric change, would arrest the chainof reactions at an earlier stage and thus reveal the mechanism :CR CBrR CBrR(non-tautomeric.)This has now been done, and a considerable number of bromoketonesof the type indicated have been isolated.40 Although they cannotenolise, they can isomerise, in the presence of hydrogen bromide,t o 6-bromo-P-naphthols :CBrR CHR Ra reaction which, if account is taken of the para-affinity in thebenzene ring, is an ordinary ay-migration, promoted by the loosen-ing influence of the adjacent carbonyl group on the bromine atom.It is strictly analogous to the well-known conversion, also in thepresence of hydrogen bromide, of ethyl a-bromoacetoacetate intoethyl y-bromoacetoacetate.41The para-addition of bromine to the meso-ring of anthracene40 K. Fries and H.Engel, Annalen, 1924, 439, 232; A., i, 1187.A. Hantzsch, Ber., 1894, 27, 356, 3168; A., 1895, i, 81; M. Conrad,Ber., 1896, 29, 1040; A., 1896, i, 409.E* 108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.has been shown to be reversible, since, on the addition of a sub-stance, such as phenol, capable of combining easily with free bromine,anthracene is regenerated. On heating in the absence of a bromine-remover, however, not bromine but hydrogen bromide is elimin-ated; 42H H, .Br BrSimilarly, the re-establishment of para-affinity in the intermediate9 : 10-additive compound obtained on nitrating 9-bromoanthracenemay take place in two ways, eliminating either water, giving 9-bromo-10-nitroanthracene, or hydrogen bromide, yielding 9-hydroxy-10-nitroanthracene.Actually there is evidence of the occurrenceof both reactions,u although the hydroxy-nitro-compound a t oncechanges into the anthrone, an instance of the keto-cyclol tautomericchange first investigated in detail by K. Meyer.44Addition to Unsaturated Side-chains.-The hypothesis that alladditive reactions of the type :[HI- + X=Y = C-X-Y[H]are reversible and hence may be employed to assist the under-standing of the triad tautomeric changes of which they are theintermolecular prototypes 45 appears to be turning out correctly.It was previously rendered probable by the proof that equilibriaarise in the aldol46 and Michael 47 additive reactions, and has nowbeen further confirmed by an investigation of the cyano-imino-additive process elaborated by Thorpe and his co-workers.Theestablishment of equilibrium was ascertained in the followingcases : 48C6H,*CiN + CH[ H] (CN) *CO,Et s C,H,*C( :N[ HI) *CH (CN) -CO,Et .C,H,*CiN + CH[HlPh.CN C,H,*C( :N[H])*CHPh*CN.Knoevenagel’s method of producing cinnamic acids by treatingaromatic aldehydes with aniline and malonic acid evidently depends43 E. de B. Barnett and J. W. Cook, J., 1924, 125, 1084.43 Idem, ibid.44 Annalen, 1911, 379, 37; A., 1911, i, 193.45 E. H. Usherwood, Chenz. and Ind., 1923, 42, 1246; A., 1924, i, 139;46 Idem, ibid.4 7 C. K. Ingold and W. J. Powell, J., 1921, 119, 1977.48 33. H. Ingold (Usherwood), J., 1924, 125, 1313.J., 1923, 123, 1717ORGANIC CHEMISTRY. 109on the reversibility of two additive processes with a commonaddition product :for the reaction is known to take place just as well (or better) whenthe pure anil is employed instead of a mixture of the aldehydeand aniline, and, in the latter case, as K.W. Rosenmund andT. Boehm have shown,@ the formation of an anil is a necessaryantecedent condition. Those aldehydes, like gallaldehyde, theinitial addition products of which with aniline [of the typeR*CH(OH)*NHPh] are too stable to lose water and give anazomethine under the conditions employed, cannot be convertedinto cinnamic acids by this method.The peculiar properties of aromatic aldehydes have frequentlybeen commented upon, especially their ready oxidation by air,which, it has been suggested, involves a tautomeric change of thedyad type into a modification possessing much greater additivepower : 50HO Ph>C:o:o + C<PH -4- z,p,h>c:o *Whether this can be confirmed or not, it is practically certainthat a peroxide intervenes as the scheme requires.The aldehydegroup can also be oxidised by an internal process, as is shown bythe fact that o-nitrobenzaldehyde, when exposed to light in anindifferent solvent, passes into o-nitrosobenzoic acid : 51M. Passerini’s remarkable observation 5, that the anils of certainaromatic aldehydes add on to carbylamines may perhaps beaccounted for in the same way :R>C*CH X P h , NPh49 Annalen, 1924, 437, 125; A., i, 733.50 E. H. Ingold (Usherwood), J., 1924,125, 1530.51 G. Heller, J . pr. Chern., 1923, [iii, 106, 1; A., 1924, i, 736.62 Gazzetta, 1924, 54, 667; A., i, 1319110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.but the theory of addition without previous isomeric change,although, perhaps, improbable 011 general grounds, cannot beexcluded on the evidence available.Orientution.-In view of the multiplicity of substitution rules,a determination of the directive action of a group not previouslyinvestigated in this connexion assumes considerable importance.The directive effect of the thiocyano-group (*S*C{N) was previ-ously unknown, and it is of interest to record that F.Challenger andA. D. Collins have found it to be ortho-para-directing, the tendencybeing towards para-substitution when other groups are absent.53The authors note the fact that the observed directive influence isin agreement with the theory of alternate polarities, but do notstate what is equally relevant, namely, that the same facts (likemost of the data on directive influence a t present available) agreejust as well with Fliirscheim’s principle of alternating affinitydistribution, the essential validity of which, and its general abilityto account for directive effects, are everywhere admitted.The onlyassumption that the known data on directive influence appearreally to justify is that some kind of an alternating property exists.As to its nature, two theories have been advanced, and the newresults are equally favourable to both.It seems desirable to point this out, because the experimentsreferred to are not the only ones which have been presented withreference to the polarity theory, although capable of more thanone interpretation.*Another interesting case is that recorded by F.L. Pyman andE. Stanley. In the nitration of 2-phenylglyoxaline, the glyoxalineresidue (XIV) directs mainly towards the para- and ortho-positionsof the phenyl group, whereas in the nitration of the 4 : 5-dicarboxy-derivative, the residue (XV) produces the opposite effect, theprincipal product being the m-nitro-compound : 54(XIV.) GH-NH>c- CH---N(mainly o-p-directing.) (mainly m-directing.)The difference between the two cases appears to be connectedwith the fact that the phenylglyoxaline yields salts with mineralacids, whilst its dicarboxylic acid does not, so that in the firstcase the substance nitrated is not the phenylglyoxaline itself but itsnitrate.On this view, the key to the orienting influence is thess J., 1924, 125, 1377.* In such cases, would it not be better to keep phraseology within theboundaries of ascertained fact,-or, at least, generally agreed deduction,-and speak of results as supporting “ the alternating principle ” ?64 J., 1924,125, 2484ORUANIC CHEMISTRY. 111condition, as regards salt format’ion, of the doubly-bound nitrogenatom, and the observed difference may be compared with thatbetween the directive effects of - NH, and of - NH,X :-/ / \(ortho- para. )The reversal of(mb. ) (meta. ) (ortho-para. )the effect on removing the nitrogen atom oneplace further from the benzene nucleus, both in the case of thebases themselves and their salts, is a particularly clear indicationof the alternating character of the influence transmitted, but, asthe authors observe, it is equally in accordance with both theoriesas t o the character of that influence.The Isomerism of the 0ximes.-The history of oxime chemistryhas recently passed through a phase which seems like an echo ofthe events of 1889-1890.65 In 1921, F.W. Atack and L. Whin-yates 56 reported the discovery of a fourth dioxime of benzil, and,partly on the strength of this, Atack 57 levelled a strong criticismagainst Hantzsch and Werner’s stereochemical hypothesis. Thisit was proposed t o discard, and replace by a purely structuraltheory, by which, it was claimed, the isomerism and properties ofoximes could be completely explained without resort to spatialsuppositions.The theory proposed embodied that of Beckmann,who f i s t suggested the “oxime” and “i~ooxime)~ formule,RR’CXOH and RR’c-NH, \o,, for the isomeric oximes usually termed“ anti ” and “ syn ” respectively; but the new theory postulatedin addition a third unstable structure, RR’C:N<E, to which thename “nitrone ’) was given. It is clear that, according t o thistheory, there should be six benzildioximes, whereas the stereo-chemical hypothesis requires the existence of only three. It wasalso suggested that the latter theory could not account for thedserences in the reactivity of the aldoximes, that it afforded noprecise mechanism for their interconversion, and that it led65 K.Auwem and V. Meyer, Ber., 1889, 22, 537, 565, 705; A., 1889, i, 607,611, 713; idem, &id., 1890, 23, 2403; A., 1890, i, 1268; E. Beckmann, ibid.,1889, 22, 429, 514, 1531, 1588; A., 1889, i, 607, 608, 979, 980; K. Auwersand M. Dittrich, ibid., p. 1996; A., 1889, i, 1192; H. Goldschmidt, ibid.,p. 3109; A., 1890, i, 251; idem, ibid., 1890, 23, 2163; A., i, 1890, i, 1261;A. Hantzsch and A. Werner, aid., p. 11 ; A., 1890, i, 348. Compare Lachman,“The Spirit of Organic Chemistry,” Chapter VIII.56 J . , 1921, 119, 1184.57 F. W. Atsck, ibicl., p. 1175112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to discrepancies when the configurations assigned on the basis of theBeckmann change could be checked, as in the case of the benzildi-oximes, by independent evidence relating to the properties of theoximes themselves.It is obvious that, although much of this indictment is true, agreat deal still remains to be said on the whole question.Leaving,for the moment, the specific objections to the stereochemical theory,it may be noted that there are three strong reasons for retainingit. (1) No purely structural theory can account for the failureto obtain more than one oxime in the case of symmetrical ketones.This point, although touched upon by Atack, is very inadequatelydealt with. (2) The stereochemical theory is the only one whichaccounts for the production of two isomeric O-ethers. The existenceof isomeric O-ethers was doubted by Atack, but, as 0.L. Brady andF. P. Dunn have pointed 0~t,58 the evidence in favour of theirexistence is overwhelming, and cannot be neglected. (3) W. H.Mills and A. M. Bains’s proof 59 of the Hantzsch-Werner hypothesisby the preparation of the optically active “ centro-asymmetric ”oxime (XVI) is apparently quite conclusive. Atack’s suggestionthat the optical activity observed by Mills and Bains might bedue to the occurrence of the “nitrone ” form cannot now beupheld, since Mills and H. Schindler 60 have obtained an optica.llyactive centro-asymmetric hydrazone (XVII),--clear proof thatHantzsch and Werner’s fundamental postulate relates essentiallyto doubly-bound tervalent nitrogen.C02H/-\=N/OH(XVI.)I H 1H (XVII. )But although the solution of the oxime problem cannot beobtained by the rejection of the stereochemical conception, thenecessity for its extension is plain, and it is by directing attentionto this fact that Atack’s critical review has been of service. Atan early date, however, Hantzsch and Werner were aware thatstructural isomerism could not be excluded, and both of themadopted the isooxime structure as the best expression for theN-ethers of the oximes.61 Their view has since been generally5 8 J., 1924, 125, 291.6o Ibid., 1923, 123, 312.6 1 A.Hantzsch, “ Grundriss der Stereochemie,” 1904, p. 120; A. Werner,59 Ibid., 1910, 97, 1866.6‘ Lehrbuch der Stereochemie,” 1904, p. 235ORGANIC CHEMISTRY. 113accepted, but a considerable body of evidence has been amassed 62in favour of the nitrone structure for the same series of compounds.This, perhaps, is to be expected, as the isooxime and nitrone formulaeare very intimately related (they are mere valency-isomerides), andtherefore much more likely to represent phases of an extremely mobiletautomeric system than individuals capable of separate existence :RR’C=NX e RR’C-NX (X = H, alkyl, etc.).\/0//0Since definite individuals of this type (isooxime, or nitrone, or both)can be isolated in the case of the alkyl derivatives of the oximes,the same type of structure may be expected to occur amongst theoximes themselves, at least as relatively unstable tautomeric forms.63It follows that although the stereochemical theory does not supplya ready-made explanation of the isomeric changes and reactivitiesof oximes, the theory, when extended on lines foreshadowed byHantzsch and Werner, leaves plenty of scope for an interpretationof these phenomena.As to Atack’s other criticisms, doubt hasbeen cast 64 on the existence of the fourth benzildioxime, and evenif it does exist, the fact would not invalidate the stereochemicalhypothesis, since the hypothetical iso- or nitrone-form might incertain cases be sufficiently stable t o have a separate existence(compare p. 114). With regard to the discrepancies relating tothe Beckmann rearrangement, the main obscurity here is themechanism of the change itself, and this question is a t presentbeing studied by Meisenheimer and his collaborators .65O2 M. 0. Forster and H.Holmes, J., 1908,93, 244; A. Angeli, L. Alessandri,and M. Aiazzi-Muncini, Atti R. Accad. Lincei, 1911, [v], 20, i, 546; A., 1911,i, 544; 0. L. Brady, J . , 1914, 105, 2104; H. Staudinger, K. Miescher, andE. Schlenker, Helv. C‘him. Acta, 1919, 2, 554; A., 1919, i, 584; K. von Auwersand B. Ottens, Ber., 1924, 57, [B], 446; A., i, 516.63 0. L. Brady and F. P. Dunn, J., 1916, 109, 659.64 Idem, ibid., 1924, 125, 291; J. Meisenheimer and W. Lamparter, Ber.,1924, 54, [B], 276; A., i, 432.65 J. Meisenheimer, Ber., 1921, 54, [BJ, 3206; A., 1922, i, 152; J. Meisen-heimer and W. Lamparter, Zoc. c i t . ; J. Meisenheimer and H. Lange, ibid.,p. 282; A., i, 433; J. Meisenheimer and H. Meis, ibid., p. 289; A., i, 433.The mechanism of the Beckmann rearrangement need not be discussedhere, as, whatever may be the solution, it can scarcely affect oxime theory,excepting, possibly, t o alter the allocation of configurations amongst groupsof stereoisomerides.It should be noted, however, that the great tendencypossessed by amphi-benzildioxime, the configuration of which is not indoubt, to pass into an anhydride seems to necessitate a new conception ofthe mechanism of anhydride formation amongst oximes (J. Meisenhemerand W. Lamparter, Zoc. cit.):P h * L C * P h Ph-C----C.Ph Ph*C---C-Ph -+ I1 fH2O. &-OH #.O114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Opinion appears, then, to be once more united on the subjectof the existence of stereoisomeric oximes of the type RR'CNOH,and it is now asked whether the iso- and nitrone-structures mayalso have definite stereochemical configurations capable of leadingto isomerism amongst the N-ethers of the oximes.The first answerto this question came in 1918, when L. Semper and L. Lichtenstadt 66obtained two crystalline N-methyl ethers of phenyl p-tolyl ketoxime,and also two O-ethers, one of which, however, was an oil and ofdoubtful purity. Recently, however, two complete series of twocrystalline N-ethers and two crystalline O-ethers have been described.Using the nitrone formula for the N-ethers, the isomerides may beformulated as follows :R+R' R-s--R' R-G-R' R-G-R'Alk0.R N-OAlk 0:NAlk AlkN:OThe first series was obtained by A. Plowman and M. A. Whiteley 67from the mesoxmono-p-tolylamide oximes,NH,*CO*C( :NOH) *CO*NH*C,€I, ,which will be referred to again below, and the second by 0.L.Brady and R. P. Mehta 68 from the oximes of p-nitrobenzophenone.I n the latter case, the configurations of the ethers follow clearlyfrom those of the parent oximes, which were oriented by the Beck-mann rearrangement, adopting the convention of &-interchangeof radicals :N02*C,H,*G*Ph N02-C6H4*G*PhI IN-OH HO*Nm. p. 158'. m. p. 115'.~ _ _ _ _ + 4 . 4 . J. J.N0,*C6H,*pPh NO2*C6H4*G*Ph N02*C6H,o~*Ph N0,*C6H4*oPhm. p. 93". m. p. 147'. m. p. 96'. m. p. 176'.It seems plain from these results that the stereochemical theoryof Hantzsch and Werner requires substantial extension, if it is to beapplied to all the ethers of the oximes; but the investigation ofPlowman and Whiteley 69 raises the further point as to whether itmay not be possible to isolate the parent isooximes themselves,and to obtain them, moreover, in syn- and unti-modifications; forthe four ethers described by these investigators were derived fromno fewer than five forms of the free oxime.It is suggested thatthese varieties include, not only the syn- and anti-modificationsof the isooxime proper (i.e., the ring form as distinct from theN*O&le MeN:O Me0.N 0:NMe66 Ber., 1918, 51, 928; A., 1918, i, 437. 67 J., 1924, 125, 587.6s LOC. cit. 6* Ibid., p. 2297ORGANIC CHEMISTRY. 115nitrone form), but also a true nitrone, in addition to the syn- andanti-forms of the normal oxime. This is a very interesting possi-bility, but as Brady and Mehta 70 point out, caution must be exer-cised in assigning definite structures to these compounds, as thepresence of the carbonyl groups, with consequent opportunitieafor tautomerism, introduces a certain ambiguity.Free Radicals.Tervalent Carbon, Bivalent Nitrogen, andUnivalent Oxygen.Terualent Carbon.-The position with regard to the triphenyl-methyl problem reached in 1910 as a result of Schmidlin andSchlenk’s classical experiments has now been thoroughly upset,and the simple scheme 71Ph,C-CPh, =+= 2Ph3C- . . . (A)(colourless, non-oxidisable) (coloured, oxidisable)a t one time regarded as established, requires additions if not actualmodifications.In order to understand the extent to which the various compli-cating influences affect the elementary conception, it is necessaryto draw a, clear distinction between ‘‘ thermal ” and electrolytic dis-sociation.When solid hexaphenylethane is dissolved in a non-dissociating solvent such as benzene, there is no doubt that“ thermal ” dissociation into the radical (equation A) is the principalreaction. If, however, a dissociating solvent, such as sulphurdioxide, is used, the solution obtained conducts electricity, andtherefore, presumably, contains ions in place of, or in addition to,the radical (equation B) : 72Ph,C-CPh, e= Ph,C@ + Ph,C@ . . . (B)Now these three triphenylmethyls, the two kinds of ions and theradical, will difEer from one another in their physical and chemicalproperties as completely, perhaps, as atomic iodine does from theiodide ion.To take the most obvious characteristic-colour-it isnot surprising that the absorption spectrum of triphenylmethyl insulphur dioxide or hydrogen cyanide is totally dif€erent from thatin non-dissociating solvents like benzene, and that with other triaryl-methyls the differences are obvious to the unaided eye.73 Thechemistry of triphenylmethyl is, therefore, in the first instance, thatof three distinct individuals, and too great emphasis cannot be laid onthis point, as much confusion has been caused by attempts to combine70 LOG. cit.71 B. Fliirscheim, J . pr. Chem., 1905, [ii], 71, 505; A., 1905, i, 614.72 Solvation is neglected in the formulae.73 M. Gomberg and I?. W. Sullivan, J. Arner. Chem. Soc., 1922, 44, 1829116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.conclusions reached by d8erent methods, without regard to theconditions under which the various experimental observationswere made.The positive and the negative ions cannot conveniently be studiedseparately in solutions of triphenylmethyl itself, but the positiveions can be obtained without their negative isomerides in solutionsof triphenylmethyl chloride, and probably the negative ions withoutthe positive ones could be found in solutions of sodium triphenyl-methyl if a suitable dissociating solvent were known :Ph3CC1 += Ph3C@ + C1@Ph3CNa e Ph@ + Na@The positive ion produced from the halide has in fact been studiedin great detail by Gomberg and his collaborators, who have shownthat i t is in equilibrium with a tautomeric quinonoid form :The negative ion has not yet been closely studied, but it is ofgreat interest that C .A. Kraus and T. Kawamura 74 have evolvedan improved method of producing the metallic c,ompounds, andhave even obtained an ammonium derivative, although this isunstable and soon decomposes into triphenylmethane and ammonia :CPh,Na; CPh3K; CPh,*NH, --+ CPh3H + NH,.The sodium, potassium and ammonium derivatives are all redsolids, the potassium compound being stable even a t 100". Themetallic compounds are obtained by the action of the metals ontriphenylmethyl chloride in liquid ammonia, and the ammoniumderivative by the action of ammonium chloride in liquid ammoniaon the sodium compound. The instantaneous character of thisdouble decomposition strongly suggests the ionisation of thesecompounds in liquid ammonia solution.It is possible that sub-stituted ammonium derivatives may be obtained by similar methods,and may prove more stable than the ammonium compound itself,and have solubilities suitable for the investigation of the negativetriphenylmethyl ion in a dissociating solvent.As regards the uncharged radical, it has been suggested 75 thatthis undergoes tautomeric change similar to that which was provedto occur in the case of the positive ion :74 J . Arner. Chem. Soc., 1923, 45, 2756; A., 1924, i, 276.75 M. Gomberg, Ber., 1913, 46, 228ORGANIC CHEMISTRY. 117However, the evidence on which this supposition is based is by nomeans clear, for, as we have seen, the results of experiments involvingthe ion have no bearing in this case.It has been proved,76 usingdiphenyl-p-naphthylmethyl in various non-dissociating solvents,that the apparent molecular weight diminishes, as it should, withrise of temperature and with dilution, but that the depth of colourincreases faster than the dissociation for a rise of temperature, andin some solvents faster, and in others slower, than the dissociationon dilution. Further, the proportion of material immediatelyoxidisable with air, with loss of colour, is always less than the pro-portion dissociated. But it is very difficult to explain these factsby the tautomeric hypothesis alone, and it is by no means clearthat they could not adequately be accounted for by the formation,with the solvent employed, of loose molecular compounds, such asthe triarylmethyls are known to have a strong tendency to produce.The question as to whether the triarylmethyl halides break upin electrolytically non-dissociating solvents to give the radical,just as they do in dissociating solvents to give the ion, has beenanswered in the affirmative, because the equilibrium betweendiphenyl- p-naphthylmethyl iodide, the free radical, and iodine hasbeen found to be of a, measurable order : 77c l o ~ ~ : / C I Ph\ Ph- Ph\ C + I ; 21 I,.'loH,'From this point of view, the numerous reactions of the triarylmethylhalides in which the halogen parts from the methane carbon atomtake on an enhanced interest; 78 as also perhaps do the reactionsof acid halides, which the triarylmet hyls closely resemble.79The tendency possessed by the triarylcarbinols to divide, inaddition reactions, thus : R,C-i-OH, as well as in the way usualamongst alcohols, namely, R,C*O-I-H, is well illustrated by someexperiments of D.R. Boyd and F. J. Smith 80 on the interactionbetween triphenylcarbinol and phosphorus trichloride. The re-action proceeds according to equation (C) to the extent of 78%of the carbinol employed (the normal reaction between phosphorus'6 M. Gomberg and F. W. Sullivan, Zoc. cit., p. 1810; A., 1922, i, 929.7 7 Idem, ibid.78 Compare J. B. Conant and A. W. Sloan's new method for the prepar-ation of free radicals by reduction of the chlorides with vanadous chloride(J.Amer. Chem. Soc., 1923, 45, 2466; A . , 1924, i; 304).79 J. F. Norris, Ind. Eng. Chern., 1924, 16, 184; A., i, 381; E. Benaryand P. Lorth, Ber., 1924, 57, [ B ] , 1324; A., i, 1192; F. F. Blicke, J. Amer.Chem. SOC., 1924, 46, 1515; A., i, 845.8o J . , 1924, 125, 477118 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.trichloride and an alcohol : Menschutkin, 1866) ; whilst about 5%of the crtrbinol reacts in accordance with equatlion (D) :ROO-i-H + PCI, --+ Rg>PC13 zz ROPCI, . . (C)R-:’-O-H + PCl, 4 ,g>PCl, =<? R*:Cl, . . . (D)0It has often been asked whether it is the “affinity-demand”or the ‘‘ space-demand ’) of the aryl residues which is responsiblefor the dissociation of hexa-substituted ethanes. Schlenk’s dis-covery8l that the p-diphenyl group has a greater dissociatinginfluence than phenyl appears to favour the view that “affinity-demand,)’ and the consequent alternation in the affinity content ofbonds, is the true cause.The same view is strongly advocated byZeigler,s2 who has found that the introduction of a gem-diphenyl-vinyl residue in place of phenyl also greatly enhances the dissocia-tion :(Enhanced dissociation.) (Enhanced dissociation.)However, if this were the only factor t o be considered, the replace-ment of phenyl by triphenylmethyl should lead to diminished - -dissociation :whereas, actually,Ph, Ph\ /Ph /PhPh/ Ph/ \Ph \Ph(Diminished dissociation.)ph+ __ . .. -. -c-c -_ ~ -._ - --C-phW. Schlenk and H. Mark 83 proved that a greatlyincreased dissociation is observed.It is plain, therefore, that tLespatial factor is of importance, and that the controlling conditionsare somewhat complex. The apparent superposition of ‘‘ quantita-tive ” and “ steric ” factors arouses the suspicion that the whole ofthese dissociation phenomena may be capable of an approximateanalysis, simila.r to that to which €3. Fliirscheim 84 submitted the81 W. Schlenk, T. Weickel, and A. Herzenstein, Annalen, 1910, 372, 1;A., 1910, i, 236.82 K. Zeigler, ibid., 1923, 434, 34; A., 1924, i, 308. Compare also K.Zeigler and B. SchnelI, ibid., 1924, 437, 227; A., i, 850.a3 Ber., 1922, 55, [B], 2285, 2299; A., 1922, i, 1002.O4 J., 1909, 95, 718; 1910, 97, 84ORGANIC CHEMISTRY. 119available data regarding the electrolytic dissociation of organicacids and bases.Bivalent Nitrogen.-Evidence of the ability of tetra-arylhydr-azines to dissociate giving a coloured and highly reactive radicalAr2N-NAr, += 2Ar2N-was first advanced by Wieland 86 in 1911.Tetraphenylhydrazine,although colourless in the solid state and in solution in the cold,gave a green solution in boiling toluene, in which the presence ofthe radical could be shown by chemical means (combination with- N O to form Ph2N-N:O),86 although the quantity present inequilibrium with the hydrazine could not be estimated. Greaterdissociation was obtained, later (1912), in the case of tetra-anisyl-hydrazine, and still greater in the case of t,etra- (p-dimethylamino-phenyl) -hydrazine (1915).The increasing dissociation when thepara-hydrogen of each phenyl group is replaced first by bivalentoxygen (OMe) and then by tervalent nitrogen (NMe2) is in goodaccord with the Werner-Flurscheim theory of affinity-demand :A comprehensive set of cases has been worked out by S. Gold-Schmidt 87 in the series of hexa-substituted tetrazanes :NR,*NR-NR*NR, z+ 2NR2*NR-.Hexaphenyltetrazane, for example, gives dark blue solutions, thecolour deepening on warming and increasing relatively on dilution.The presence of the triphenylhydrazyl radical, NPh,*NPh-, isshown by the formation of the com$ound NPh,*NPh*NO withnitric oxide, and by the instantaneous reduction by quinol totriphenylhydrazine, NPh,*NPhH.As might be expected from the more complex nature of theradical, the relative dissociating influence of dif€erent substituentsreveals more complex effects than are observed in the triarylmethylsor the diarylnitrogens.Diphenylpicrylhydrazyl is a singularsubstance. It is definitely monomolecular, even in the solid state,crystallising in black-violet prisms, which look like potassium per-manganate. Quinol instantly reduces it to the hydrazine, and the85 H. Wieland and H. Lecher, Annalen, 1911, 381, 200; A., 1911, i, 669;Ber., 1912, 45, 2600; A., 1912, i, 907; ibid., 1915, 48, 1078; A., 1915, i, 848.86 It is noteworthy that this reaction was shown to be reversible like theunion of triarylmethyls with iodine.87 Annalen, 1924, 437, 194; A., i, 884; see also Ber., 1920, 53, [B], 44;A., 1920, i, 257; S.Goldschmidt and K. Euler, Ber., 1922, 55, [BJ, 616; A.,1922, i; 475120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.change of colour is so marked that the radical can readily be esti-mated by titration with quinol.The diacyltetra-aryltetrazanes also are markedly dissociated,but somewhat less so, on the whole, than the hexa-aryl derivatives :NAr(CO*R)*NAr---NAr*NAr(CO*R) =+= 2NAr(CO*R)*NAr-By considering a series of related compounds, the superpositionof a spatial and a quantitative, and possibly also a polar, influencemay be perceived, although no regular connexion with the strengthof the acid corresponding with the acyl group can be discovered.The following “ order of dissociation ” is illustrative of the factsthat have been accumulated : diacetyltetraphenyl < dibenzoyl-tetraphenyl < diacetyltetratolyl < dibenzoyltetratolyl < diacetyl-tetra(pdimethylaminopheny1) ; the last member of the seriesbeing almost completely dissociated under ordinary conditions.It is of interest that, as with triarylmethyls and their correspond-ing ethanes, the equilibration of the hydrazyls and their tetrazanesis a definite and measurable time reaction.This circumstance,and the fact that the radicals are instantaneously reduced by quinol,have enabled Schmidlin’s classical experiment with triphenylmethylto be paralleled in the case of the hydrazyls. Titration with q u i dto complete decoloration indicates the fraction of tetrazane originallydissociated ; soon, however, the red colour returns, and the solutionthen becomes able to react instantaneously with a further quantityof quinol.The only essential distinction from Schmidlin’s experi-ment is that whereas he destroyed his dissociated material byoxidation, Goldschmidt employed reduction.In view of the puzzling discrepancies noticed by Gomberg andSullivan (p. 117) when following quantitatively the effect of dilutionon the dissociation of hexa-arylethanes, it is reassuring to noticethat the tetrazanes dissociate strictly in accordance with Ostwald’sdilution law, and that the results can be confirmed colorimetrically.This may, perhaps, be taken as an indication that Gomberg andSullivan’s discrepancies are due to some extraneous influence, andare not likely fundamentally to alter the conception of free radicals.Univalent Oxygen.-In 1914, Wieland 88 prepared diphenyl-nitric oxide, which may be formulated as containing either quadri-valent nitrogen or univalent oxygen :or ph>N-d. PhA more definite example of a free radical containing univalentoxygen was obtained, in 1922, by S.Goldschmidt, 59 who found that8 8 H. Wieland and M. Offenbacher, Ber., 1914, 47, 2111; A., 1914, i, 955.89 Ibid., 1922, 55, [B], 3194; A., 1922, i, 1148ORGANIC CHEMISTRY. 121guaiacol, on oxidation with lead peroxide, gave a green solutionwhich was immediately decolorised by quinol or by triphenylmethyl.The suggestion advanced to account for these facts is conveyed bythe following formula? :\/-OH (PbOd \)-O- -but neither the green nor the colourless compound could be isolated.Better fortune has, however, attended more recent investigationsin the phenanthrene series.-+ /~\-o*cH, - ~)-o*cH, CH,*O-(~\/-O-O- \/(Green.) (Colourless. )In the case :/\( Yellow-green.) (Colourless. )the colourless compound was isolated. Its yellow-green solutiongave figures for the molecular weight indicating 37% dissociation,and in an analogous example with OEt in place of OMe there was62% dissociation.Finally, in the example :both the colourless and the blue compounds were isolated, anddissociation to the extent of 69% was observed in an equilibratedsolution.91In every case the free radical was instantly reduced by quinolor hydrazobenzene, and it combined with triphenylmethyl ; bothreactions, of course, involve loss of colour.A remarkable pointwas the slowness with which equilibrium was reached, several hoursbeing usually required in cold solution ; it is this fact which enabledboth individuals, in the last case, to be isolated from the equilibratedsolution by fractional precipitation.90 S. Goldschmidt and W. Schmidt, B e y . , 1922,55, [B], 3197; A., 1922,i, 1149.Dl S. Goldschmidt and C. Steigerwald, Annalen, 1924, 438, 202 ; A., i, 1062.C. K. INGOLD122 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.P-4RT III.-HETEROCYCLIC DIVISION.LAST year will probably prove a, memorable year in the chemistryof alkaloids. It has witnessed the completion in detail of thesynthesis of Z-cocaine, the almost sensational proof that t'he " syn-thetic berberine " of Pictet and Gams is not berberine, but astructural isomeride, the synthesis of a complex base which mayprove to be closely allied to strychnine, the completion of theinteresting investigation of the Anhalonium alkaloids and thebeginning of what looks like a general attack on the Chelidoniumalkaloids.This Report has therefore been written with the workon alkaloids as its centre-piece with other work dovetailed into it .where possible. For this reason, many important results, e.g.,those on heterocyclic compounds containing carbon-sulphur andoarbon-oxygen, are not mentioned, but it is hoped to deal withthese in future Reports.Pyrrole Derivatives.Mention was made in the previous Report of the large amountof work in progress on the synthesis of complex derivatives ofpyrrole related to naturally-occurring substances or their degra-dation products, and the output of results in this direction showsno diminution this year.The ease with which p-phenylethyltrimethylammonium hydroxidedecomposes quantitatively into styrene and the tertiary base hasled to the investigation of this reaction as a means of preparingmore complex tertiary bases, and in this way ethyl l-p-phenyl-ethylpyrrolidine-2 : 5-dicarboxylateY by conversion into the quater-nary ammonium hydroxide, has been used for the production of1 -methylpyrrolidine in good yie1d.lDi- and tri-substituted pyrroles with a free cc-position, whentreated with excess of bromine, yield crystalline dyes, which aremostly dipyrrylmethenes, produced by the loss of hydrogenbromide between the original substance and the dibromopyrrolefirst formed; thus, the dye furnished by the action of bromineon ethyl 2 : 4-dimethylpyr~ole-3-carboxylate results from theinteraction of the hydrogen atom in position 5 in a molecule oft4e original substance and the bromine atom of the bromomethylgroup in the first formed ethyl 5-bromo-4-methyl-2-bromomethyl-J.V. Braun and R. 5. Cahn, Ann&%, 1924,436, 262 ; A , , i , 632 ; compareA., 1911, i, 611.A . , 192.1, i, 80;compare Ann. R e p o d , 1923, 20, 137.' Hans Fischer and H. Scheyer, ;bid., 1923, 434, 2 3 7 ORGANIC CHEMISTRY. 123pyrrole-3-carboxylate, giving rise to a dipyrrylmethane, which isthen oxidised by excess of bromine to the dipyrrylmethene (I),These initial halogenated pyrroles condense with aniline and withliydrazines, giving rise to complex derivatives.Thus ethyl 4-methyl-2 - bromomethylpyrrole- 3 : 5 -dicarboxylate yields, with hydrazine,cca-di(3 : 5-dicarbethosy-4 - metlhyl - 2 - pyrrylmethyl)hydrazine, andthis when treated with cuprammonium acetate loses nitrogen andforms s-di-(3 : 5 - dicarbethosy - 4 - methyl - 2 - pyrry1)ethane. The5 : 5’-dicarboxylic acid from this condenses with formic acid inpresence of hydrochloric acid to give 5 : 5’-di-(3”-carbethoxy-4”-methyl- 2” - pyrrylmethyl) - 4 : 4’ - dicarbethoxy - 3 : 3’-dimethyl-2 : 2’-dipyrrylmethene (11). This tetrapyrrole derivative is~ - N H -~--CII=~--N==~ IC( CO,Et)*CR!le CMe=== C*C02Etintensely yellow in colour and closely resembles mesobilirubin,4C,,H,,O,N,, obtained by 11.Fischer from bilirubin, one of thebile pigments.The same author has embarked on the study of tetrapyrrylethaneswith an investigation of the compound produced by the conden-sation of glyoxal with ethyl 2 : 4-dimethylpyrrole-3-carboxylate indkaline- or acid-alcoholic solution and to which the followingformula is assigned :It gives an intensely green-coloured solution with acetic acid, isoxidised by ferric chloride to bis-3-carbethoxy-2 : 4-dimethyl-pyrrylmethene, and on reduction by hydriodic a’cid in acetic acidyields a mixture containing 2 : 4-dimethyl- and 2 : 4 : 5-trimethyl-pyrroles. The a,cid obtained by hydrolysis of the ester is differentfrom that produced by direct condensation of glyoxal with 2 : 4-di-me th j-lpyrrole-3 -c arboxylic acid.The evidence so far obtained indicates that the tetrapyrrylethanesHans Fischer and H.Scheyer, Annalen, 1924, 439, 185; A., i, 1232.Hans Fischer, Ber., 1914, 47, 2330; 2. EioZ., 1914, 65, 163; A . , 1914,j , 1135; 1915, i, 148124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.are more closely related to the pigments of bile than to those ofThe application of the Gattermann reaction to the preparationof aldehydes in the pyrrole series has been utilised by Fischer andhis collaborators,6 and among the interesting fission products ofthe blood pigment, hzemin, so prepared are cryptopyrrole- (I)and phyllopyrrole-carboxylic acids.8 The starting-point for theformer was ethyl 2 : 4-dimethylpyrrole-3-aldehyde-5-carboxylate(TII), which was condensed with cyanoacetic acid, and the productreduced (TI), hydrolysed, and decarboxylated successively a tpositioiis 3 and 5.2 : 4 : 5-Trimethyl-3-(~-cyano-w-carboxyvinyl)-bl00d.5Meg-G*C,H,*CO,H1’ (I.) HC\,CMeNHMe~-~*CH,*CH(CPU’J.CO,H + MeG-G*CHO (In. )EtO,C*CvCMe (11.1 EtO,C*C\,CMeNH NHpyrrole (corresponding to I1 before reduction) cannot be hydrolyseddirectly, but on melting loses carbon dioxide, forming 2 : 4 : 5-tri-methyl-3(~-cyanovin~d)pyrrole, which on rediiction and hydrolysisyields phyllopyrrolecarboxylic acid (2 : 4 : 5-trimethylpyrrole-3( a)-propionic acid); the latter can also be obtained by the reductionof the 3 : 4 : 5-trimethylpyrrole-3(p)-acrylic acid formed when thepyrrole-3-aldehyde is condensed with malonic acid.The fissionproducts of hzemin-cryptopyrrole, hEmopyrrole, and phono-pyrrole-have also been used for the preparation of aldehydes andthe latter for similar synthe~es.~Galegine , a supposed simple derivative of pyrollidine, whichG. Tanret 10 isolated from Galega oficinalis, has now been shownto be a derivative of gunnidine to which G. Barger and F. D. White l1assign the formula CMe,:CH*CH,*NH*C( :NII)*NH, or possiblyCH,:CMe*CH,*CH,*NH*C( :NH)*NH,, whilst E. Spath and S .Prokopp 12 prefer the form CMe,:CH*CH,*N:C(NH,),.Hans Fischer and M. Schubert, Ber., 1923, 56, [B], 2379; A., 1924,i, 217; compare Ann. Reports, 1923, 20, 138.Hans Fischer and J.Muller, 2. physiol. Chem., 1924, 132, 73; A., i, 319;compare Ann. Report8, 1923, 20, 137, and Angeli, Bet-., 1924, 57, [B], 534;A., i, 760.H. Fischer and B. Weiss, Ber., 1924, 57, [ B ] , 602; A., i, 543.H. Fischer and C. Nenitzescu, AnnaZen, 1924, 439, 172; A., i, 1233.Hans Fischer and M. Schubert, Ber., 1924, 57, [B], 610; A., i, 544.Paris, 1917; BuZE. SOC. chim., 1924, [iv], 35, 404; A., i, 622.lo Compt. rend., 1914, 158, 1182, 1426; A., 1914, i, 721, 859; Thesis,n Bwchem. J . , 1923, 17, 827; A., 1024, i, 272.l2 Ber., 1924, 57, [BJ, 474; A., i, 502ORGANIC CHEMISTRY. 125Pyridine Derivatives.B. D. Shaw 13 has shown that 2-stilbazole (I) in aqueous alcoholis reduced by sodium to 2- p-phenylethyltetrahydropyran (V) andthe action is assumed to take place in the following way :H CH,/\ /\-N (I.) NH (11.) OH OH (111.)Pyridine itself is similarly converted into ammonia and traces ofFission of thering in this case also appears to take place after stage 11, and i t issuggested that the large amount of resin produced is due to theaction of the alkali on glutardialdehyde (corresponding to stage 111),formed when the ring is opened.P. Baumgarten l4 has found thatthe additive compound formed between pyridine and ethyl chloro-sulphonate is t'ransformed by aqueous sodium hydroxide intosodium sulpharnate and the sodium salt of the enolic form ofglutacondialdehyde, ONa*CH:CH*CH:CH*CHO ; a second form ofthe sodium salt indicates that the aldehyde may also exist in theThe sodium salt is recon- cyclic form,vertible into pyridine by boiling with ammonium acetate, Theformation of pyridine bases by the passage of acetylene and ammoniaover alumina heated at 400" has now been investigated in detail.15The products formed include pyrroles, a- and y-picolines, p-collidine,and two other collidines, which are not identical with 4-methyl-2-ethyl pyridine, or 2 : 3 : 4- or 2 : 3 : 6-trimethylpyridine.Asimilar ring condensation occurs when acetylene is replaced byacetaldehyde, paraldehyde, or propiona1dehyde.l6 These reactions,volatile oil, which may be pentamethyleneoxide.CH<d,.CH>CH*OH. CH-01 3 J., 1924, 125, 1930; compare Ann. Reports, 1923, 20, 147.14 Ber., 1924, 57, [B], 1622; A., i, 1166.l6 A.E. Tschitschibabin and others, J . Russ. Phgs. Chem. SOC., 1915,47, 703 ; 1924, 54, 607, 611 ; A., 1915, i, 638; 1924, i, 313.16 Idem, aid., 1924, 54, 601 ; A., i, 312; J . pr. Chein., 1924, [ii], 107, 132,138, 145, 154; A., i, 766, 567; 0. Seide, Ber., 1924, 57, [B], 791; A., i,767126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.supplemented by the sodamide method 17 for introduciiig theamino-group into the resulting and other bases, have providedmeans for the synthesis of a series of substituted pyridines andquinolines. Since 2-phenoxypyridine is convertible into l-phenyl-pyridone a t a red heat, it seems clear that direct conversion oftautomeric forms is possible and is not limited to indirect formationthrough quaternary halides.18 The sodium salt of 2-pyridohe istransformed by carbon dioxide under pressure a t 180-200" into2 - hydroxypyridine-5- carboxylic acid .I9 2 -Aminopyridine appearsto be capable of acting in the sense of the tautomeric pyridone-2-imine (I) form, since it condenses with ethyl malonate t oform 4 : 6-diketo-1 : 2-divinylene-1 : 4 : 5 : 6-tetrahydropyrimidine *O(malonyl-a-aminopyridine) (11).,4ccording to E. Sucharda 212-aminonicotiilic acid condenses with chloroacct ic acid in presenceof potassium carbonate to give a good yield of pyridylglycine-carboxylic acid (I), which is converted by mineral acids into S-keto-2 : 3-dihydro-1 : 7-benzdiazole-2-carboxylic acid (IT) ; and this onoxidation by permanganate yields the dehydro-compound (111) :this constitutes the first synthesis of a pyridopyrrole, analogous toindole.I klf*CH,-CO,H -1 1 'CHC0,Z-I +I \/(&CO,IIN(1.1 (11.1 (111.)2-Aminonicotinic acid also condenses with formamide and acet-amide, giving small yields of 4-hydroxy-1 : 3 : 8-benztriazine (IV)and its 2-methyl derivative, respectively.The second of these isreadily soluble in water, acids, or alkalis, and is consequentlybelieved to have the lactim structure (V). The alternative structure/\CO H /\-co /\-coN\/\/N NH\/0 OH OH1 7 A. E. Tschitschibabin, D.R.-P. 374291, with Kirssanov, Ber., 1924,18 A. E. Tschitschibabin and N. P. Jeletzky, Ber., 1924, 57, [B], 1158;l* A. E. Tschitschibabin and A. W. Kirssanov, aid., 1161; A., i, 988.90 A.E. Tschitschibabin, Ber., 1924, 57, [B], 1168; A., i, 987.21 Roczniki Chemji, 1923, 3, 236; A., 1924, i, 881.57, [B], 1163; A., i, 203, 978; compare Ann. Reports, 1923, 20, 146.A,, i, 987ORGANIC CHEMISTRY. 127(VI) is untenable, as the parent substance shows none of the reactionsof a primary amine and differs from the methyl derivative mainlyin showing more acidic characters.22of the isolation ofpyridine methides resulting from the action of sodium hydroxideon pyridine methosulphate. Similar products had already beenmade by W. Schneider and his collaborator^,^^ who have nowdescribed a number of their characteristic reactions. They wereprepared by treating quaternary salts of a- or y- methylated pyridines(or quinolines) with alkali ; thus a-picoline methosulphate yieldsAT-methyl-a-methylenedihydropyridine, and y-picoline the corre-sponding 7-methylenedihydropyridine. These substances combinewith carbon disulphide, phenylthiocarbimide or phenylcarbimideto form compounds of the following types (cc-picoline derivatives),(I) representing the compound formed with carbon disulphide[I J-cirz0c:s I \/ '1 I:CH*CS*NHPh ~~--CH2*CB*N€€€'h \/Mention was made in the previous Report/\ /\R*NX R*N 'y s RON -(1.1 (11.) (111.)and (11) that with phenylthiocarbimide, whilst (111) represents thesalts (addition of HX) formed by compounds of type (11) withacids.These additive products are well-crystallised substances,and the formulz are in harmony with the facts that they are stableto acids, but not to cold permanganate solutionYz5 although E.Rosen-hauer 26 formulates what appear to be strictly analogous carbondisulphide additive products, derived from quinoline, somewhatdifferently .Similarly 1 : 4 : 6-triphenyl-2-methylpyridinium iodide, obtainedby treating 4 : 6-diphenyl-2-methylpyrylium iodide with aniline,when treated with alkali f urnishcs the corresponding anhydro-base,1 : 4 : 6-triphenyl-2-methylenedihydropyridine. The latter formsadditive compounds with the three reagents mentioned above, andthis is also true of a series of similar substances prepared a t thesame time.27 The first of these products made was obtained byi, 883.22 L. Klisiecki and E. Sucharda, Roczniki Chernji, 1923, 3, 251 ; A., 1924,Ann. Reports, 1923, 20, 147.24 W.Schneider and F. Seebach, Ber., 1921, 54, [B], 2285; A., 1921,2s W. Schneider, K. Gaertner, and A. Jordan, ibid., 1924, 57, [BJ, 522;28 E. Rosenhauer and others, ibid., p. 1291 ; A., i, 1236 (analogous quinoline2 7 W. Schneider and others, Annalen, 1924, 438, 115, 147; A., i, 1107,i, 877; El. Decker, ibid., 1905, 38, 2493; A., 1905,.i, 667.A., i, 651.compounds); J. pr. Chern., 1924, [ii], 107, 232; A, i, 768.1109128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the action of phenylhydrazine on 4 : 6-diphenyl-2-methylpyryliumiodide, and the anhydro-base obtained from it by the action ofalkali was formulated as 1 -phenylamino-4 : 6-diphenyl-3-methylene-dihydropyridine (I, as the phenylcarbimide additive product 28 ofthe acetyl derivative).It behaves in some reactions as such, butPh PhA /\(I.) Phil 1:CHGONHPh ~h [<,he (11. \/XNPh N*NPhAcis unusual in being intensely blue in colour instead of red or yellow,and although it combines with carbon disulphide, etc., it does soslowly, and it adds on 2 mols. of phenylcarbimide. It is believedthat in this case the presence of a phenyl group in position 4 somodifies the valency distribution as to convert the substance intoa pyridinephenylimine (11), although it may act as a niethylenebase due to tautomeric change.When 2 : 6-diphenyl-4-p-hydroxyphenylpyrylium chloride istreated with aniline, it. yields 1 : 2 : 6-triphenyl-4-p-hydroxyphenyl-pyridinium chloride (C2,H2,0NC1,0.5HC1, bright yellow), which,on heating, gives the neutral chloride (C,9H2,0NCl, dark red), andthis with boiling alcoholic ammonia furnishes a dihydrate of thedark red anhydro-base, 1 : 2 : 6-triphenyl-4-quino-1 : 4-dihydro-pyridine.The yellow chloride is believed to have the benzenoidstructure (I) and the anhydro-base the quinonoid constitution 29 (11)./\ /’\ /\ /\\/ \I/ \/ \/HO(I*) I I Phi: :IPh I I PhI Iph (I1.)NPh\ / 8 N*Ph -c1Comparatively little work has been done on naturally-occurringpyridine compounds, but the interesting new observation has beenmade that trigonelline,30 so far only found in plants, occurs in oneof the sea-urchins (Arbatia pustulosa), the only simple pyridinecompound so far recorded in marine animals being pyridine metho-hydroxide.28 W. Schneider and others, Ber., 1921, 54, [B], 2285 ; 1922, 55, [B], 2775; ;A., 1921, i, 877; 1922, i, 1171.29 W.Dilthey and others, J. pr. Chm., 1924, [ii], 107, 7; A., i, 553; com-pare A., 1920, i, 448; 1921, i, 735; 1922, i, 272.80 F. Holtz and others, 2. Biol., 1924, 81, 67; A., i, 907; compare alsoD. Ackermann and others, tbid., 1924, 81, 61; A., i, 243, 978; compareA., 1923, i, 1155ORGANIC CHEMISTRY. 129Quinoline Group.Much of the work published on quinoline derivatives is mainlyof technical interest.When ar-p-tetrahydronaphthylamirre is used for the quinaldinesynthesis, both the linear (6 : 7-tetramethylenequinaldine) and theangular (5 : 6-tetramethylenequinaldine) compounds are formed ;the yield of both is increased by high concentration of hydrochloricacid .3lFurther evidence of the intermediate formation of anils inSkraup's quinoline synthesis 32 is afforded by the observation thatmethylisopropenylaniline, obtained from acetoneanil and methylsulphate, is converted by cyanoacetic or chloroacetic acid into thedimeride, which is transformed by dry hydrogen chloride a t 180-200" into 2 : 4-dimethylquirioline.334-Tetrahydroquinolone 34 has been synthesised by condensingtoluene -p -sulphonanilide with p -chloropr opionic acid to toluene -p-sulphonyl- p-anilinopropionic acid (I), which is then dehydratedwith phosphoric oxide in boiling xyleiie to toluene-p-sulphonyl-4-tetrahydroquinolone (II), and this on hydrolysis gives 4-tetrahydro-quinoloiie.If, however, substance (I) is digested with phosphorylchloride, dehydration (with ring closure) and chlorination occurand toluene-~-sulphony1-3-cliloro-4-tetrahydroquinolone (111) isformed. The latter on prolonged ebullition with hydrochloric widloses the toluene-p-sulphonyl group, and the chlorine atom is simul-taneously replaced by hydrogen, also giving 4-tetrahydroquinolone.co CO,H co/\/\ /\ %H2 /\/I I ICH2 f- I I (CH, + I\/\/"H?.\/\/N*S O,*C,H,\/\/N*S O,*C,H N*S 02*C7H -(11. ) (1.) (111.)On digestion with methyl-alcoholic potassium hydroxide, substance(111) is quantitatively converted into 4-methoxyquinoline (V).Two suggestions are offered in explanation of this reaction, (a) thatC*O*SO,*C,H, OMe Me co/ \ A H ' CH/\/\t- i + CHI1 I I /\/\CHClNI I 1 bH2 _3 I I /H I \/\/OK N*SO,*C,H ,$1 J.Lindner and ot,hers, Monatsh, 1924, 44, 337; A., i, 1102; compare82 Compare Ann. Reports, 1923, 20, 149.88 E. Knoevenagel and others, Ber., 1923, 56, [B], 2414; A., 1924, i, 205.s4 G. R. Clemo and W. H. Perkin, jun., J., 1924, 125, 1608.\/\/N\/\!/(IV. 1 (V. 1 (VI.)v. Braun and Gruber, Ber., 1922, 55, [ B ] , 1710; A., 1922, i, 762.REP.-VOL. XXI. 130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the toluene-psulphonyl group migrates to position 4, f orminq anester (IV), which then reacts to give the methyl ether (V) or( b ) that an unstable dihydro-derivative (VI) is formed by removalof hydrogen chloride, which passes into the stable 4-methoxy-quinoline. This method of synthesis is not general and 2-methyl-tetrahydroquinolone could not be obtained by replacing p-chloro-propionic acid by p-chlorobutyric acid.4-Tetrahydroquinolone is a highly reactive substance. Thephenylhydrazone undergoes the Fischer indole reaction, but oxid-ation also takes place producing 3 : 4-quinindoline (VII) isomericwith ordinary 2 : 3-quinindoline (1’111).It also condenses withisntin to form dihydro-2 : 3-quinoyuinoline-4-carboxylic acid (IX),which has not been isolated, as it loses carbon dioxide at. 210°,C:N*T”HPh NH NH/\/\ /A/\/\/\/\/\-I I I I I I II I 1 \/ \/\/--\//\/\CH,I I ICH, \/\/NH \/‘\/ (VII.) (VIII.) PI’giving the dihydro-base, and this on distillation over lead oxidegives 2 : 3-quinoquinoline. The special interest of this condensationCH, HO,C CH, HO,C CH,/\/\/\I I I ICH2CH,/)NH + isatin /\/\/\XHco!/\ - + I I I I\/\/\/\ \/\/\/\N I I(X.) \/ N I I(IX.) \/I I\/product is that it resembles in structure J.von Brauii and P.Wolff’s 5 : 6-dihydro-a-naphthacridine-7-carboxylic acid 35 (X),which exhibits some of the pharmacological properties of strychnine(compare p. 143).When 2-nminoyuinoline is heated with 2-chloroquinoline, thehydrochloride of 2 : Z’-diquirrolylainine, which exists in two modi-fications (I) and (11), is f0rrned,3~ as would be expected on thegrounds advanced by Scheibe to explain dimorphism in the cyanine\/\ /\/ \/\ /\/ /\/\ /\/\I I-NH 1 I I LN-1 I I I I I I I/\/ -\/\ /\/ \/\ \/\/=\/\/N N NH N NMe N-Me1(1.) (11.) (111.)a5 Ber., 1922, 55, [B], 3675; A., 1923, i, 143; compare J.von Braun andaa Miss F. Ri. Hamer, J., 1924,125, 1348; compere E. Diepolder and others,A. Stuckenschmidt, ibid., 1923, 56, [B], 1724; A, 1923, i, 947.J . pr. Chenz., 1923, 106, 41; A., 1924, i, 994ORGANIC CHEMISTRY. 131series.37 Methyl iodide converts this substance into a mixture of2 : 2’-diquinolylamine h ydriodide (I) and 1 -methyldihydroquinolenyl-2-quinolyl-2’-imine methiodide (111) (now named 1 : 1 ’-dimethyl-azocyanine iodide, the two quinoline residues being linked by:No instead of by :CH* as in isocyanine). The latter forms a mixtureof orange and yellow crystals, both having the same melting pointand absorptlion spectra arid therefore probably being geometricalisomerides.Comparison with the analogous 1 : 1’-dimethyl-$-isocyanine iodide (red) show that the replacement of :CH* by IN=causes a shift of the absorption bands towards the inore refrangibleend of the spectrum.Angostura AEkaZoidc.-From angostura or cusparia bark threewell-characterised alkaloids, u k . , cusparine, C,gH1703N, galipine,C2,H2,03N, and galipoidine, ClgH,,O4N, have been isolated. Forgalipine, Triiger and Kroseberg 3* suggested a formula which repre-sents it as 7-methoxy-4( $)-3’ : 4’-dimethoxyphenylethylquinoline.E. Spath and 0. Brunner 39 have now synthesised the latter sub-stance by condensing m-methoxyaniline with ethyl acetoacetateto 2-hydroxy-7-methoxy-4-methylyuinoline and converting thisthrough the 2-chloro- derivative into 7-met~hoxy-4-methylquinoline,which with 3 : 4-dimethoxybenzaldehyde in presence of zinc chlorideyielded 7 -methoxy-4( P)-Y : 4‘-dimethoxyphenyl-A~-ethinylquinoline ;this on reduction with hydrogen in presence of palladinised charcoalgave the product sought.Neither i t nor the isomeric 2(@)-3’ : 4’-dimethoxyphenylethylquinoline compound proved identical Kithgalipine arid the clue to tlhe constitution of the alkaloid was foundin Troger’s observation that galipine on oxidation yields an acid,C,,H,O,N, which is probably a methyl ether of the similar acid,C1,H70,N, produced by the oxidation of cusparine. It was sur-mised that this acid was 4-methoxyqninoline-2-carboxylic acidand with this in mind 4-methoxy-2-methylquinoline was condensedwith yiperonal and the resulting base reduced, when cusparineresulted. Cusparine must therefore be 4-methoxy-2( p)-3‘ : 4’-niethylenedioxyphenylethylquinoline (I), and the obvious con-clusion that galipine must be cusparine with the methylenedioxy-N MeO*Q*CH( O€€)*CH--N- H2 1 (bH2)2 p (‘I.)CH,-bH-CH*CHMeI(Q = Quinolyl residue.)\/\/OMe (I.)G.Scheibe and others, Ber., 1920, 53, [B], 2064; 1921, 54, 786; A.,1921, i, 62, 451.38 Arch. Pharm., 1912, 250, 494; A., 1912, i, 895.Ber., 1924, 67, [B], 1243; A., i, 1226.S132 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.group replaced by two methoxy-groups has been confirmed by theqynthesis of galipine from 4-methoxy-2-methylquinoline and3 : 4-dimethoxyben~aldehyde.~~Matrivie, C1,H2,0N2, was isolated from Soph,orn angustij'olia byPlugge in 1895, and has recently been worked a t by H.Kondo 41and his colleagues, whose results so far are mainly of interest inindicating some similarity in structure between matrine andcytisine, the typical alkaloid of the genus.QzLinine.--K. W. Rosenmund and C. Kittler 42 have shown thathydriodoquinine, C2,H,,0,N2T, is a mixture of two isomeric bases(a), having [a]= - 74~3"~ and ( b ) , having [.ID - 128.3". The formeron reduction gives dihydroquinine and is represented by formula 11,whilst in (b), which reduces to niquine (nichin), C,0H2402N2, thequinuclidine bridge is probably ruptured as suggested by L6ger 43for niquine .isoQuinoline Derivatives.A new method 44 for the preparation of tetrahydroisoquinolineand its rir,g liomologues consists in treating acyl derivatives ofsubstituted glycine with phosphorus pentachloride and aluminiumchloride successively, e .g ., p -m- tolyle th ylbenzenesulphonylglycine(I) can in this way be converted into 2-benzenesulphonyl-6-methyl-tetrahydroisoquinoline (11). The yields are st'ated to be good.6-b~ethoxytetrahydroisoquinoline has also been synthesised bya routine method .45Of the seven alkaloids present in Anhaloizium species the con-stitutions of five are k n o ~ n , * ~ since either they or their met4hylethers have been synthesised. The two remaining bases, anhalonineand lophophorine, have now been prepared by E. Spath andJ. Gang1.47 The former is 6-methoxy-7 : 8-methylenediosy-l-40 E. Spath and H.Eberstaller, Ber., 1924, 57, [B], 1687; A., i, 1335.4 1 K. Kondo and others, J . Pharm. SOC. Japan, 1899, No. 84; 1903, Nos.260-262; 1921, pp. 659, 1047; 1923, No. 498, p. 644; A., 1921, i, 882;1822, i, 269; 1924, i, 76.42 Arch. Pham., 1924, 262, 18; A., i, 982.4s Compt. rend., 1919, 169, 797; A., 1919, i, 597.44 J. von Braun and others, Ber., 1924, 57, [B], 908; A., i, 873.4 6 L. Helfer, Helv. Chim. Acta, 1924, 7 , 945; A., i, 1341.46 Ann. Rep&, 1922, 19, 162; 1923, 20, 154.4 7 Monatsh., 1923, 44, 103; A., 1924, i, 69ORGANIC CHEMISTRY. 133meth yltetrahydroisoquinoline and the latter is the N-methylderivative of this. The seven alkaloids form an interesting series :(I) hordenine, (11) rnezcaline, (111) anhalamine, (IV) anhalonidineO-methyl ether, (17) gellotine O-methyl ether, (VI) anhalonine,(VII) lophophorine./N/\CH2CH2 CH2 CH2Me O/\/\CH, (c)@\/\CH, 1 IN(b) HOdI I INMe, Me01 \/ I INH, (d)\,\/ORIe (4 CWa)(1.) (II. 1 (111.) t o (VII.)\/I n 111, a = H, b = H, c, d, and e, = HO, OMe, OMeI n IV, a = Me, b = H, c , d, and e = OMe.I n V, a = Me, b = Me, c, d, and c = OMe.I n VI, a = Me, b = €1, c = OMe, d and e L- *O*CH,*O.I n VIT, a = Me, b = Me, c = OMe, d and e = *O*CI-T,*O.Berberine and Allied -4Ikaloids.-Tn assigning a formula tocryptopine, one of the many data used was the fact that it waspossible t o convert the alkaloid through isocryptopine into epi-berberine, a substance which only differs from berberine by theinterchaiige of positions between the piperonyl and veratryl reeid ucsas shown by the following formulr~.~bisoCryptopin e Berb eriniu m epi Berberiniumchloride.chloride. hydroxide .It ought therefore to be possible to apply the method of Pictetand Gams 49 €or the synthesis of berberine to the preparation ofepiberberine, but it was found 5" that, using the formyl derivativeof 1 -homopiperonyl-6 : 7-dimethoxytet~rahydroi~sooyuinoline (I) inthis way, the substance obtained was not the expected cpiberberinebut an isomeride, which is named tetrahydroanhydro-+-epiberberine4 8 W. H. Perkin, jun., J., 1918, 113, 492.40 Compt. rend., 1911, 153, 386; A., 1911, i, 807.J. S . Buck and W. H. Perkin, jun., J., 1924, 125, 1675134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.(IT), condensation having taken place, with the aid of the nitrogengroup, a t position 6 in place of position 2 as in the supposed ber-QMe OMe*berine synthesis.This new base yields a series of derivativesanalogous to, and isomeric with, but different from those furnishedby tetrahydroanhydroepiberberine. It then became of interest toascertain, if possible, why the reaction proceeded differently in thecase of 1 -veratryl-6 : 7-rnethylenedioxytetrahydroisoquinoline (XII),the material used by Pictet and Gams in the synthesis of berberine,but on repeating this work it was found that the substance pro-duced was not tetrahydroarihydroberberirie, but an isomeride ofthis, 27i;z., tetrahydroanhydro-q-berberine (IV), condensation havingtaken place in this instance also at, position 6 instead of position 2.(111.This again gives a series of derivatives analogous to, and isomericwith, but different from those of berberine.Similarly, repetitionof Pictet and Gams’s experiments in the synthesis of oxyberberinefailed to yield the latter base or indeed any crystallissble product.51I n the course of the work just described, it was noticed 52 that the6 : 7-dimethoxy-3’ : 4’-metliylenedioxy-l -benzoyl-3 : 4-dihydro-iso-yuinolines (I) and the corresponding 6 : 7-methylenedioxy-3’ : 4’-dimethoxy-compounds, all of empirical formula C~19H1,04N, readilyoxidised on exposure in solution to the atmosphere, forming basesof the formula ClgH1,Q,N (11). The latter are (a) reducible bytin and hydrochloric acid to the corresponding substituted benzyl-tet.rahydroisotjuinolines (IIT), and (15) oxidised by boiling withmethyl-alcoholic potassium hydroxide, losing two atoms of hydrogenfrom positions 3 and 4, giving bases of type IV.On benzoylation,in presence of alkali, compounds of type I1 (initial oxidation51 R. D. Haworth, W. H. Perkin, jun., and J. Rankin, J., 1924,125, 1686.sa J. S. Buck, R. D. Haworth, and W. H. Perkin, jun.? ibid., p. 2176ORGANIC CHEMISTRY. 135products) take up the elements of one molecule of benzoic acid, andthe new derivatives (formulated as type V or VI; the latter beingconsidered the more probable), on digestion with acid, lose benzoicacid and form salts ol the original bases (type 11).CHZ CH, CHRO/\/\CH, aerial \/\CH, further \/\\C)H-.+ I I*/\/-/\ /\J reduct ioiiCHZ CH, CH,Ro!,/\fl 1 1 oxiz,,)\h oxidationf: ( ~ l * ) ~ o \ g (117.) yo y ;r2 (I.) I IOR’\/OR’\/\CH, \/\CW2 or \/\CH, I INCOPh I INH*COPh AhH /\/ /\/\ yH2 / T /\(111.).YH (v.) Y*OH (vI.) YOyoPapaveraldine, the first oxidation product of the alkaloid papa-verine, is a base of type IV, and in conformity with that view itwas found that 6 : 7 : 3’ : 4’-tetramethosy-I -benzyl-3 : 4-dihydro-isoquinoline (formula I, where R and R’ = Me) oxidised on exposureto air to a base C,,H,lO,N (Type 11), and this on digestionwith methyl-alcoholic potassium hydroxide gave papaveraldineChelidonium Alkaloids .---Seven alkaloids occur in the greatercelandine (Chelidonium majus) , of which one, methoxychelidonine,is new, and six, old and well-known, uiz. (a,) protopine and allo-cryptopiiie (p- and y-homochelidonines), for which formuh havebeen proposed, and ( b ) chelidonine, homochelidonine, chelerythrine,and sanguinarine.FormulE are now proposed for the first two ofgroup b. Further, it is known that homochelidonine can be con-verted into chelerythrine, and it has now been established that“ sanguinarine” is a mixture of chelerythrine and a dehydro-chelidonine or +-chelerythrine, obtained by the gentle oxidationof chelidonine. This second group of four alkaloids is the subjectof a series of long papers by J. Gadamer and his pupils.53 Theybelong to what has been called the phenanthrene group of iso-quinoline alkaloids, of which apomorphine is perhaps the bestknown esample.M’hat may be regarded as the parent of this63 Arch. Pharm., 1919, 257, 298; 1920, 258, 148; 1924, 262, 249; A.,1920, i, 75, 872; 1921, i, 579; 1924, i, 1227; also ibid., 1924, 262, 452, 501,578.(Type w136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.group has been synthesised and christened aporphine (I), buthas not yet been described. It is proposed to re-name tJheOHgroup after it. Formula I1 represents chelidonine, C,0H,s05N,with a dioxymethylene group in ring ( a ) , possibly at’ positions 2 and3, and another in ring (d), possibly a t 5 and 6. The new alkaloid,methoxychelidonine, has, in addition, a methoxyl group, probablya t 1, and homochelidonine differs from chelidonine only in havingtwo methoxyl groups in place of one of the dioxymethylene groups.It will be seen that formula I1 is based on Pschorr‘s apomorphineformula with the new feature of a 7-ring (c).In its reactionschelidonine presents a general resemblance to other members ofthe group to which it is assigned. Thus on exhaustive met,hylationit produces trimethylamine and a substance, C1sH1404, regardedas a phenanthrene derivative. By the action of hot acetic anhydride,1 mol. oE water is lost and X-acetylanhydrochelidonine, C,,HISO,N,is f orrned, indicating that a tertiary nitrogen atom originally presenthas been converted into a secondary, probably by the opening ofring (c) between thc NMe and C (13) positions, and re-closing of thering between C (13) and C (12).The loss of water takes placebetween C (10) and C (9) ; this last step also explains the disappear-ance of optical activity in this reaction, the final position beingrepresented by partial formula 111. A similar change takes placeHOHCH, CH,\ /’“\I,/;”\NMe \(\/$G€*NMeAcI I ‘ZICH, /\A/ 11‘CH2 (III.)I 1 /\/\&H21 1when clielidonine is methylated, two methines, A and E, beingformed, which are regarded as stereoisomeric, C (12) becomingasymmetric, and their formation is regarded as again due to theopening and reclosing of ring ( c ) as described above, the side chain,*CH*NMe,, being formed at position 12.Among the considerations which led to the adoption of thisformula for chelidonine and its allies, including protopine andallocryptopine, is the suggestion that these types of alkaloid mightbe formed in plants by the interaction of phenylacetaldehydeORGANIC CHEMISTRY.I37N-methylphenylethylamine, and formaldehyde, and two schemeswhereby this condensation might occur are discussed.Derivatives of l'ropane and Granatane.Much of the work done in these two groups centres round theproduction of local anzst'hetics. R. Willstatter, 0. Wolfes, and€1. Mader 54 have found that methyl tropinonecarboxylate onreduction yields three oat of the four possible racemic methyl-ecgonines. One of these on benzoylation furnishes r-cocaine, fromwhich d-cocaine and Z-cocaine, the latter identical with the naturalalkaloid, were obtained by fractional crystallisation of the hydrogend-tartrates.A second r-methylecgonine was deracemised by theuse of d-a-bromocamphor- p-sulphonic acid, and the resolved pro-ducts on benzoylation furnished 2- and d-$-cocaines, the latterbeing identical with Einhorn's d-cocaine made from d-ecgonine(now called pseudoecgonine), produced by the action of alkali onordinary Z-ecgonine from natural Z-cocaine. The third racematehas not been fully examined. According to R. Gottlieb, +con-figuration in the cocaines favours local anzesthetic action, themost powerful of the forms referred to above being d-$-cocaine.I n both series, the d-form acts less powerfully than the Z-formon the central nervous system, and on this and other grounds ithas been suggested that d-+-cocaine may not be habit-forming;but recent pharmacological and clinical trials in this countryindicate that it may not prove to have much, if any, practicaladvantage over ordinary Z-cocaine as a local a n ~ s t h e t i c .~ ~Little success has so far attended attempts to improve cocaineas an anzesthetic by the replacement of benzoyl by other acylgroups, but W. Stcinkopf and W. Ohse state that thiophen-2-carboxylic acid produces a " thiophen isologue " as active ascocaine and less The corresponding " t'hiophenatropine "has also been made.57S. Frankel and G. Gruber have observed that with excess ofmagnesium methyl iodide in ice-cold ethereal solution cocaine (I)yields phenyldimethylcarbinol and tropyldimethylcarbinol : thelatter and certain of its salts are local an~esthetics.~~In this connexion may also be mentioned S.M. McElvain's 59comparison of ethyl 4-benzoyloxy- l-methylpiperidine-3-carboxylate54 Annalen, 1923, 434, 111 ; A., 1924, i, 70; compare E. Merck, Brit. Pat.5 5 Watson-Williams, Brit. Med. J . , 1925, i, 11; Copeland, 2 i d . . p. 9.6 6 Annalen, 1924, 437, 14; A . , i, 661.5 7 W. Steinkopf and A. Wolfram, ibid., p. 22; A., i, 661.58 Ibid., 1923, 433, 241; A., 1924, i, 72.59 J . Amer. Chem. SOC., 1924, 46, 1721; A., i, 985.210050; A., i, 870.I?138 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.(11) with the corresponding open-chain compound, p-carbethoxy-ethyl-y-benzoyloxypropylmethylamine (111). The first is lessactive as an anzsthetic than cocaine and as toxic, and the secondis scarcely anzsthetic.CH,-~H-~H*CO,Me $!H,-~H*CO,Et I r*MeCH*OBz YMe FH*OBzCH,- C H-hH, CH,-CH,(1.1 (11.1p-Eucaine, one of the best known partialC H,-CH,*CH,*OBz(111.)substitutes for cocaine,and its isomeride, iso- p-eucaine, produced by the benzoylation ofa- and p-vinyldiacetonalkamines (4-hydroxy-2 : 2 : 6-trimethyl-piperidines), respectively, have been deracemised by H.IZing.60The details of both resolutions present a number of interestingfeatures. The racemic forms and their optically active com-ponents are all equally active on the rabbit's cornea, but on thesciatic nerve of the frog p-eucaine is more powerful than iso-p-eucaine : the 1-form of p-eucaine is more toxic than the d-form.By an extension of the method used for the synthesis of tropin-one,C1 R.C. Menzies and R. Robinson have prepared +-pelletierine(N-methylgranatonine) (I), a ring homologue of tropinone, fromglutardialdehyde, methylamine, and calcium acetonedicarboxylate.Adipdialdehyde yielded a base having the properties of a homo-t,bpelletierine.62 These syntheses afford a further confirmation ofRobinson's views as to the mode of origin of alkaloids in plants.61S. M. McElvain and R. Adams have produced an interestingvariant on N-methylgranatonine by synthesising ethyl isogran-atoninecarboxylate (11). On reduction, it yields the correspondingalcohol, ethyl granatolinecarboxylate, and this on benzoylationfurnishes an isomeride of a homococaine ; it is more toxic and lesspotent as an anzsthetic than cocaine.63~H2-~H--$!H2 7H2-7H-70(1.1 YH, YMe 70 7H2 $JH*CO,Et (11.1CH,--CH--CH, CH2-N - CH,Derivatives of Indole and Carboline.CH,Ph*NPh*CH,*CO*R,where R may be an aryl or alkyl radical, should undergo intramole-cular condensation producing either indoles or isoquinolines, theformer are exclusively formed even when substituents f avourableAlthough t,ertiary amino-ketones of the typeao J., 1924, 125, 41.6% J., 1924, 125, 2163.68 J.Amer. Chem. Xoc., 1923, 45, 2738; A., 1924, i, 417.61 Compare Ann. Reports, 1017, 14, 134ORGANIC CHEMISTRY. 139to isoquinoline formation are present ; thus m-hydroxybenzyl-aniline, when condensed with w-bromoacetophenone by phosphoruspentoxide in hot xylene, furnishes 1 -m-hydroxybenzyl-3-phenyl-indole (I), and this on distillation with zinc dust is converted intom-cresol and 2-phenylindole.64Hu CO*Ph HUCatalytic hydrogenation of indole takes place in much the sameway as with quinoline,65 addition of hydrogen to the heterocyclicnucleus occurring first, although substituents in either ring in-crease its resistance.I n some cases, action proceeds further ;thus, 2 : 5-dimethylindole yields as chief product o-propyl-p-tolu-idine, and 2 : 4 : 7-trimethylindole gives 3 : 6-dimethyl-2-propyl-aniline, and in most cases complete decomposition with evolutionof ammonia occurs to some extent.The alkaloids harmine and harmaline are derivatives of 6-meth-oxyindole, and the probability that indoles occur in other complexnatural products lends special interest to the synthesis of a seriesof these compounds and their derivatives.G6 It had been shownpreviously 67 that whilst indole-2-carboxyacetalylamide (I), whenwarmed with hydrochloric acid, forms 5-keto-4 : 5dihydroindole-diazine( 1 : 4), indole-2-carboxydimethylacetalylmethylamide (11)yields 3-keto-4-methyl-3 : 4-dihydro-4-carboline, condensationtaking place in the direction indicated by the arrows.On extending(11.)this reaction t,o 6-methoxyindoles, it was found that the methoxy-group appeared to f avour azine condensation (I), since 6-methoxy -64 K. H. Bauer and K. Buhler, Arch. Pharm., 1924, 262, 128; A., i, 985.66 J. von Braun and others, Ber., 1924, 57, [ B ] , 392; A . , i, 545; compareO 6 K. G. Blaikie and W. H. Perkin, jun., J . , 1924, 125, 296.*' W. 0. Kermack, W. H. Perkin, jun., and R. Robinson, J., 1921, 11%1626; 1922, 121, 1874. For numbering of carboline rings, see J., 1919,115, 970; 1921, 110, 1642; compare Ann. Reports, 1922, 19, 128.Ann. Reports, 1923, 20, 149, 150.B 2140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.indole-2-carboxydimethylacetalylmethylamide yields both azineand carboline, but examination of other cases involving 4-, 5-, 6-,and 7-methoxyindoles has given results indicating that the methoxylgroup is not the dominant factor, except perhaps when it occupiesposition 7, and that the chief factor influencing the direction ofring closure is the N-methyl group in the side chain, its presencefacilitating carboline formation.W. Lawson, W. H. Perkin, jun., and R.Robinson68 have in-vestigated it number of methods for the preparation of polynuclearsystems allied to harmine. The similarity of carbazole to harminesuggested the trial of known methods of preparing carbazole tothat of synthesising carbolines. Del6tra and Ullmann’s method 69proceeds smoothly in simple cases, e.g., 2-chloropyridine condensesreadily with o-phenylenediamine to give N-a-pyridyl-o-phenylene-diamine, which with nitrous acid yields 1 -a-pyridylbenzotriazole(I). Thebenzenoidquantities,latter, though more stable than the correspondingbases, yields 3-carboline (11) when heated, in smallwith zinc chloride or phosphoric acid. Similarly, from2-chloroquinoline, benzo-3-carboline was prepared, and it wasshown to be identical with Gabriel and Eschenbach’s 70 “ quin-indoline.” R.Robinson and S. Thornley have applied the samemethod to the preparation of karboline 71 from N-y-pyridyl-o-phenylenediamine, obtained from 4-chloropyridine.It may therefore prove to be a general method of obtainingcarbolines, but, unfortunately, the triazole (111) which couldprobably be transformed into harmine could not be made owingto the non-reactivity of halogens in the p-position in the pyridinering. Condensation of 3-aminoquinaldine and 3-amino-Z-methyl-pyridine with appropriate chloronitrobenzenes was also tried, butwithout success. apoHarmine has, however, been synthesised bya novel process. 6 : 6’-Dinitro-3 : 4 : 3’ : 4’-tetrametlioxybenzo-phenone was reduced and the resulting diaminoveratrone condensedin acetic acid with bromoacetone; the first product (I) of thisaction, treated with alkali, formed methyldiveratroharmyrine (11),and this after demethylation was oxidised by chromic acid t o a6 8 J., 1924, 125, 626.70 Ber., 1897, 30, 3020; A., 1598, i, 199.Arch.Sci. phys. nat., 1904, [v], 17, 78; A., 1904, i, 270.7l J., 1924, 125, 2169ORGANIC CHEMISTRY. 141tetracarboxylic acid (due to the loss of the two benzo-groups)which on distillation yielded czpoharmine (111).Me0 Me0Meof) M e 0 0\/\CO-/\OMc \/\-/\ORle /\-I I IO%fe 4 I I IN\/\/Me NHNH2CI--, /\/\/ I loMe b\/\/ Me NHMe-OC NII(1. ) (11.) (111.The final operations assumed a microscopic character owing tothe destruction of material in the vigorous action necessary insteps I1 to 111, but the production of any qoharmine at allillustrates the stability of the heterocyclic nucleus of harmine.The main reaction has been used to build up even more complexderivatives of the harmine type ; thus, by condensing diamino-veratrone with benzoylacetone, dibenzoylmethane, etc., derivativesof the general type IV may be built up, and the substancerepresented by V was obtained from diaminoveratrone and1 : 3-diketohydrindene./-\R R'N/\/\NI l l(IV*) /\/\A%\/ \/ MeOl 1 I l0MeMe0 Me0i-i I IAlthough the constitution of harmaline (I) is now known, thoseof methylharmaline '2 and acetylharmaline are still uncertain.CK2 CH2 C*2 CH,/\-/\CH2 - /\CH, /\cw2 I INMe T(,>Me]ClC-CH, CXH,/'\/ Me01 I I INNH CMe(1.) (11- ) (111.) (IV. 1co \/\/\/This problem is dealt with by H. Nishikawa, W. H. Perkin, jun.,and R. R~binson.'~ Harmaline itself is stable to permanganate inacetone, but the methosulphate and met hylharmaline are oxidisedto keto-N-methyltetrahydronorharmine (11), which is converted72 0. Fischer, Ber., 1897, 30, 2484; A., 1898, i, 164; ibid., 1914, 47, 102;73 J., 1924, 125, 657.A., 1914, i, 316142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.into harmaline methochloride (111) by dilute hydrochloric acid,whence it follows that methylharmaline must have the consti-tution IV. Acetylharmaline is reduced by hydrogen in presenceof palladium to acetyltetrahydroharmine (V) and on oxidationfurnishes acetylketotetrahydronorharmine (VI), and must there-fore be represented by (VII).On hydrolysis by alcoholic potassiumhydroxide, acetylketotetrahydronorharmine (VI) yields 6-methosy-3- p-aminoethylindole-2-carboxylic acid (VIII) and the corresponding- /\CH, /\CH, - /‘CH2 \-CH2*CH2*NH2CH, CH2 CH2I ~ N A C &.&IL~ 1 ~ N A ~ /\/ I ICO,HNH/\/CXH,/\/CHMe(V. ) (VI. ) (VII. ) (VIII.)lactam (analogous with 11), but the latter is not convertible intothe amino-acid by further action of the hydrolytic agent, andthe two substances are doubtless produced simultaneously byhydrolytic fission a t the two points shown by dotted lines in VI.Another interesting synthesis in this series has been describedby G. M. Robinson and R. Robinson 74 by way of further experi-mental evidence against the view 75 that Reddelien’s explanation 76gives the best account of the mechanism ofFischer’s indole synthesis, the reaction used\/\ /\CH2 being exactly analogous to the latter.3-Amino-1 I ICH quinaldine was diazotised, the product reducedN(/\/\/ to 3-hydrazinoquinaldine7 and this condensedwith cyc7ohexanone to form 3-methylbenzo-(6 : 6)-.9 : 10 : 11 : 12-tetrahydro-4-carboline (annexed formula),which, i t will be seen, represents benzotetrahydroharman anda derivative of crpoharmine (see p. 141).Y. Asahina 7 7 has now obtained 3-aminoethylindole by thedegradation of evodiamine, thus confirming the modified formulafor this alkaloid suggested by Kerrnack, Perkin, and Robinson.78Eserine.-In last year’s Report an account was given of thedegradation products of this alkaloid.E. Stedman 79 has nowshown that when eserethole methiodide is heated under reducedpressure physostigmol ethyl ether sublimes from it. There wereindications that this was an indole derivative and possibly 6-ethoxy-CH,/\I IMe NH CH274 J., 1924,125, 827; compare ibid., 1918, 113, 639.7 6 C. Hollins, J . Amer. Chem. SOC., 1922, 44, 1598; A., 1922, i, 863; com-pare Ann. Reports, 1918, 15, 97; 1922, 19, 139.7 6 Annalen, 1912, 388, 179; A., 1912, i, 263.7 7 J . Pharrn. SOC. Japan, 1924, No. 503, 1; A., i, 665.7 8 J., 1921, 119, 1615; compare Ann. Reports, 1921, 18, 142.79 J., 1924, 125, 1373ORGANIC CHEMISTRY. 1431 : 3-dimethylindole (11), and confirmation of this was obtainedby the synthesis of the latter by condensing p-ethoxyphenylmethyl-hydrazine with a-ketoglutaric acid and decarboxylating the5-ethoxy-2-carboxy-1-methylindole-3-acetic acid (I) formed.Thissynthesis settles the position of the hydroxyl group in eseroline.-CMe 11 llCH (11.) \/\/ -+NMe */ \/ NMeM. and M. Polonovski 8o have shown that eserethole and eserinecan behave as secondary bases forming nitroso- and benzoyl-derivatives and on this and other grounds suggest that both basescan exist not only in the tricyclic tertiary base form but also assecondary open-chain bases due to the opening of the reducedpyridine ring, a suggestion already made by G. Barger and E.Stedman 81 to explain the unusual behaviour of eserine onmethylat’ion.Derivatiues of Carbnzole.Most of the work done on carbazoles during 1924 is closelyassociated with that on strychnine and brucine described belowand is alluded to there, but a few other interesting observationshave been made.H. Burton and C. S. Gibson 82 have describeda method for the preparation of 9-alkylcarbazoles, which dependson condensing N-alkylanthranilic acids with o-bromonitrobenzeneto give the corresponding alkyl-2’-nitrodiphenylamine-6-carboxylicacids. These, when heated with sulphuric acid, furnish a smallamount of the corresponding 9-nitro-N-alkylacridone, and onreduction to the corresponding amino-acids and diazotisation ofthe latter followed by treatment with sodium hydroxide give goodyields of the 9-alkylcarbazoles, which have so far only been obtainedhy alkylation of carbazole itself.CO/\ /\/\I l l 1\/\/\/NR NO,Strychnine and Brucine.I n 1910, W.H. Perkin, jun., and R. Robinson,83 after a critical80 Compt. rend., 1924,178, 2078; 179, 57, 178, 334; A., i, 980, 1093, 1094.*l J., 1923, 123, 760.83 J., 1910, 97, 305; compare E. Oliveri-MandalA, Qaszetta, 1924, 54,82 J., 1924, 125, 2501.516; A., i,)llOl144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.review of the experimental data available regarding these twoalkaloids, suggested the following formuh for them in whichMe0 CH,CHStrychnine. Brucine.they are represented as possessing the skeletal system of an anhydro-(5 : l0-dihydro)-acrindoline-21-acetic acid (see I1 below). Sincethen, in spite of much work on the subject, but little progress hasbeen made.G . R. Clemo, W. H. Perkin, jun., and R. Robinson 84have now given an account of their attempts to build up the struc-tures represented by these formulax This has been tried by threemethods. It was hoped by reducing nitrosoacridone-9-aceticacid ester (I) with zinc dust in acetic acid in presence of cyclo-hexanone to produce anhydroketohexahydroacrindolineacetic acid(11), C,,H,,O,N,, but the substance actually produced is 5-keto-co coCO,Et*CH,*$?*NO5 : 10 : 16 : 17 : 18 : 19-hexahydroacrindoline, C,,H,,ON,, whichimplies the removal of the -CO-CH,- residue and its replacementby two atoms of hydrogen a t positions 10 and 21, so that the doublenitrogen ring (d in 11) is not formed. This elimination of the-CH,*CO,Et group may be analogous to the hydrolysis of brucinolicacid to brucinolone and glycollic acid observed by Leuchs andWeber; 85 the reaction has been investigated by W.H. Linneland W. H. Perkin, jun., for other derivatives of acridine andtetrahydrocarbazole.86The method was then modified to ensure the formation of ring( d ) before condensation with cyclohexanone was attempted.6-Casboxydiphenylamine-2'-acetic acid was esterified, when ring-closure also occurred, producing anhydro-6-carbethoxydiphenyl-amine-2'-aminoacetic acid, the nitroso-derivative (111) of which84 J., 1924, 125, 1751.85 Ber., 1909, 42, 771; A., 1909, i, 353.86 J., 1924, 125, 2451ORGANIC CHEMISTRY. 145was reduced in presence of cyczohexanone, forming anhydro-8-o-carbethoxyphenylaminotetrahydrocarbazole-9-acetic acid (IV) .It was now necessary to form ring ( b ) to complete the supposedstrychnine skeleton, but although no difficulty was experienced indehydrating 2'-nitrodiphenylamine-6-carboxylic acid t o form9-nitroacridone (compare p.143), one of the primary materialsused in the first series of experiments, all attempts t o effect thecorresponding change in IV failed.()CO,H /\ I 1 CH, Thus with sulphuric acid the ester(v.) /\ /\/'\/\cH was merely hydrolysed to the acid.NH I I I C H ~ Boiling methyl-alcoholic potassiumhydroxide opened ring ( d ) , produc-ing 8 - o-car box yphenylamino tetra-hydrocarbazole-9-acetic acid (V), and this was equally insusceptibleof the double ring closure, although the lower ring (cl) could beformed by the action of sulphuric acid, producing anhydrocarboxy-phenylaminotetrahydrocarbazoleacetic acid (IV as ester).The difficulty of forming the double heterocyclic ring systemwas thought to be due to the -CO- in the acridone complex, andinterest was therefore transferred to the building up of derivativesof dihydroacridine in which -CH2- replaces -0-.It was foundpossible to reduce 9-nitroacridone to 9-amino-5 : 10-dihydroacridine,and the acetyl derivative of the latter, by oxidation followed byhydrolysis, gave 0-aminoacridine, from which, by condensationwith chloroacetic ester, ethyl ncridine-9-aminoacetate was pro-duced. The nitroso-derivative of this, however, on reduction inpresence of cyclohexanone, gave no carbazole derivative, the nitroso-group being unexpectedly eliminated.Finally, recourse was had to the method already referred to,formation of indolediazines (p.139), but although the necessarydimethylacetalylaminodihydroacridine was made, it could not beinduced to furnish the required dihydroindolediazine. It was thenfound that chloroacetic ester with 9-amino-5 : 10-dihydroacridinegives anhydro -5 : 10 -dih ydroacridine-9 -arninoacetic acid (VI)directly, and the nitroso-derivative of this, on submission to theusual reaction, condenses to anhydrohexahydroacrindolineaceticacid, C,,H180N, (VII), which possesses the skeletal system onCO2H*C1I2*Np\/'H146 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which the formula of strychnine is built up, but differs fromstrychnine in empirical composition by having one oxygen andfour hydrogen atoms less.Like strychnine, it gives in acetic(VII.)or sulphuric acid solution an intense purple coloration with chromicacid. One striking difference is that on hydrolysis by potassiumhydroxide in methyl alcohol, strychnine furnishes strychninic acid(opening of ring d), whilst the new substance. is partly oxidised,since on again boiling with hydrochloric acid in alcohol there isformed, not only the original substance, but also some ethyl tetra-hydroacrindoline-21 -acetic acid (VIII) ; if atmospheric oxidationis allowed to take place freely, this ester is the sole product of thcfurther action of hydrochloric acid in ftlcohol,CH CH,Anhydrohexahydroacrindolineacetic acid (VII) is reduced 87 elec-troly'tically in presence of sulphuric acid in alcohol to 21 -p-hydroxy-ethyloctahydroacrindoline (IX) by the opening of ring ( d ) and re-duction of its components :N*CO*CH2*N: to :NH and CH,OH*CH,*N:just as in the reduction of strychnine to tetrahydrostrychnine,with, however, the difference that in the new substance two hydro-gen atoms are added a t positions 15 and 20.When dist)illed withzinc dust, anhydrohexahydroacrindolineacetic acid (VII) is partlyconverted into 10 : 21-ethano-5 :10 : 16 : 17 : 18 : 19-hexahydro-acrindoline, for which formulze X and XI were considered ; thelatter was regarded as improbable after examination of the be-haviour of N-vinyl derivatives of carbazole and tetrahydrocarb-azoles with acids,88 in itself an interest,ing and complicated piece87 For a detailed study of the reduction products of carbazoles and acridines,see W.H. Perkin, jun., and S. G. P. Plant, J., 1921, 119, 1825; 1923, 123,676; 1924,125, 1503; A., 1924, i, 1104; and w. H. Perkin, jun., and W. G.Sedgwick, J., 1924, 125, 2437.** G. R. Clemo and W. H. Perkin, jun., J., 1924,125, 1804ORGANIC CHEMISTRY. 147of work, which showed that these substances with warm, dilutesulphuric acid suffered disruption with elimination of the vinylgroup and formation of carbazole. The new substance is stableCH CH,CH CHunder these conditions and shows the behaviour and propertiesexpected from a dihydroquinoxaline; thus on reduction it addson four atoms of hydrogen, two in ring ( d ) and two between rings( e ) and (f), becoming 10 : 21-ethano-5 : 10 : 15 : 16 : 17 : 18 : 19 : 20-octahydroacrindoline, and this on further reduction (electro-lytically) suffers fission o€ ring ( d ) with the formation of an ethylside chain a t 21 and the a,ddition first of two atoms of hydrogena t 15 and 20 and finally of four more a t positions 6, 7, 8, 9.The formulz originally proposed for strychnine and brucine(p.144) were largely based on A. Hanssen’s observations9 thaton oxidation with chromic acid strychnine yields carbazole, andalthough many of the results of previous workers have been con-firmed in the course of the present work, it has not been possibleto confirm this particular observation, so that the fundamentalassumption that strychnine is a carbazole derivative may not bejustified .Derivatives of Glyoxaline.2 -Meth ylgly oxaline and 4- bromo -2 -methylgly oxaline can besulphonated under the same conditions as glyoxaline itself, andthis is in harmony with the view that the sulphonic acid groupenters at position 4, although direct proof of this has not beenobtained yet.90 l-Methylglyoxaline brominates 91 in the samemanner as glyoxaline, but the resulting 2 : 4 : 5-tribromo-l-methylglyoxa.line is more resistant to reduction by sodium sulphite than2 : 4 : 5-tribromoglyoxaline.With methyl sulphate, 4(or 5)-bromo-glyoxaline yields both 5-bromo- (51 yo) and Q-bromo- (1.5C,?(0)-1-methylglyoxalines. The latter is better obtained by distilling4(or 5)-bromo-1 : 3-dimethylglyoxalinium iodide, an observationwhich negatives J. Sarasin’s 92 statement that Wallach’s 4.01-Ber., 1884, 17, 2849; 1885, 18, 7 7 7 ; A . , 1885, i, 63, 819.R. Forsyth, J. A. Moore, and F. L. Pyman, J., 1924, 125, 919; compare91 I. E. Balaban and F. L. Pyman, J . , 1924, 125, 1564; compare Ann.82 Helv. Chim. Acta, 1923, 6, 370; A., 1924, i, 710.Ann. Reports, 1920, 17, 115.Reports, 1922, 19, 143148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.5)-chloro-l -methylglyoxaline methiodide on distillation yields5-chloro-1 -methylglyoxaline ; this correction has since been con-firmed.93 The 4(and 5)-bromo-l-methylglyoxalines (I, Br == 5) arereduced by hydriodic acid and phosphorus, but are unaffected byboiling aqueous sodium sulphite. The reactivity of the halogenis enhanced by the entrance of a nitro-group in the ortho-positionto the halogen and in 5-bromo-4-nitroglyoxaline (11) t,he halogenis replaced by a sulphonic acid group (111) (on boiling with aqueoussodium sulphite) and the latter can be removed by hydrolysis,thus affording identifiable reference products (in this case 4-nitro-l-methylglyoxaline, IV). While the halogens or the nitro-group,RBroNT>CH (11.) + NO,*C--(I.) GBreNM:>CH -+ CH---h(111.) HO,S*G*NMe>CH + RKome>CH (IV.)NO,*C-N NO,*C--Nand possibly the -CO- group, in positions 4 (or 5 ) in glyoxalinefavour the formation of alkyl derivatives of the type 5-nitro-l-alkylon alkylation, methyl, cyanomethyl, and allied groups act in theopposite way and favour the formation of derivatives of the 4 : 1-type. Phenyl as a primary substituent takes an anomalousposition ; thus 4( or 5)-phenylglyoxaline yields the 4-phenyl-l-methyl and 5-phenyl-l-methyl derivatives in the ratio of 4.8 : 1.On the other hand, the influence of the phenyl group is like thatof the nitro-group and the halogens in affecting the products ofdistillation of the methiodides of 4- and 5-substituted 1 -methyl-glyoxalines, the 4 : l-substituted glyoxalines being the sole orthe dominant product ; thus 4(or 5)-phenyl-1 : S-dimethylglyox-alinium iodide yields 4-phenyl- 1 -methylglyoxaline with only asmall amount of the 6 : l-i~omeride.~~J. Sarasin and E. Wegmann 95 record the preparation of hetero-xanthine from 5-chloro-4-nitro-l-methylglyoxaline 93 (I). Thelatter was converted into 5-cyano-4-nitro-l-methylglyoxaline, thisYH-CO(1.) (11.1 (111. )into the corresponding acid, and the 4-amino-amide of this (11)treated with ethyl carbonate, when it yielded heteroxanthine (111).s3 J. Sarasin and E. Weg-nann, Helv. Chim. Acta, 1924, 7, 713; A., i, 1114.94 C. E. Hazeldine, F. L. Pyman, and (the late) J. Winchester, J., 1924,95 HeEw. Chim. Acta, 1924,7, 713; A., i, llL4; compare R. G. Fargher and125, 1431.F. L. Pyman, J., 1919, 115, 217ORGANIC CHEWSTRY. 149Benziminaxolc.s.-In 1922, 0. Fischer 96 showed that the pro-ducts formed by the interaction of o-aminoazo-compounds withaldehydes and subsequelit reduction with hydriodic acid are nottriazines as supposed by 13. Gold~chmidt,~~ but l-aminobenzimin-azoles, and a long series of these substances has now been preparedby this means. The action oi: benzyl chloride on o-aminoazo-compounds did not yield the expected N-aryldihydrobenzimin-azoles, but their decomposition products, e.g., aniline and 2-phenyl-naphthiminazoles .Pyrasoles and I?daxoles.Rosenruund’s method 98 for the preparation of aldehydes hasbeen successfully applied to a number of pyrazole~.~~ A catalystwas unnecessary, but unless dry, oxygen-free hydrogen was used,acid anhydrides resulted. The pyrazole-3- and -5-aldehydes areoils with the general reactioiis of aromatic aldehydes. They donot undergo the benzoin or Csnnizzaro reactions, the latter affordingonly traces of the carboxylic acid with resinous by-products as inthe case of pyrrole-a1dehydes.lto someof the problems confronting the worker on indazole derivatives.Auwers and his colleagues have now made a further study of thetetraliydroinda~oles,~ acylinda~oles,~ and alkylinda~oles.~ Excessof semicarbazide converts methylhydroxymethylenecyclohexanoneinto the disemicarbazone (I) which, in hot dilute sulphuric acid,jields a mixture of the interconvertible labile and stable forms ofReference was made two years ago in these Reports/\,CH:N*NH-CO*NH, /\//CH\y0*NH2 /\//”\ I PH - 1 1 N and I I N\/“-/I \/:K*NH*CO*NH, \/“-/Me Me Me CO*NH,7-methyltetrahydroindazolecarbonamide (11) and (111), which areregarded as stereoisomerides . From these carbonamides the96 0. Fischer and others, J . pr. Chem., 1922, [ii], 104, 102; A., 1922,97 Ber., 1890, 23, 487; 1891, 24, 1000; A., 1890, 614; 1891, 839.98 K. W. Roseninund and others, Ber., 1918, 51, 585; A., 1918, i, 300;C. A. Rojahn and others, Annalen, 1923, 434, 252; 1924, 437, 297;H. Fischer and W. Zerweck, Ber., 1923, 56, [BJ, 519; A., 1923, i, 364.Ann. Reports, 1922, 19, 132.I<. von Auwers and others, Annalen, 1924, 435, 277; A., i, 325.Ibid., 1924, 438, 1; A., i, 878; Ber., 1924, 57, [B], 1723; A., i, 1348;compare J. Meisenheimer and A. Diedrich, Ber., 1924, 57, [B], 1715; A.,i, 1347.(1.1 (11- ) (111.)i, 956; ibid., 1924, [ii], 10’7, lti; A., 1924, i, 559.ibid., 1921, 54, [B], 425; A., 1921, ii, 320.A . , 1924, i, 91, 875.Ber., 1924, 57, [B], 1098150 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.tetrahydroindazoles are obtained by boiling with mineral acids.With phenylhydrazine, on the contrary, a mixture of the non-interconvertible 1 - and 2-phenyltetrahydroindazoles is formed, therelative proportion in which 1 - and 2-substituted derivatives areformed being dependent on (a) the concentration of the hydrion,( b ) temperature of reaction, ( c ) the nature of the hydrazinederivative-phenyl, phenylmethyl, benzyl, and so on.On alkylation, 1 - or 2-alkyl-substituted tetrahydroindazoles, orboth, are formed depending partly on the nature of the alkyl groupand partly on the experimenbal conditions, but methyl in position 7inhibits alkylatioh in position 1.As the result of a detailed study of the relative stabilities ofthe labile forms of the acylindazoles and a comparison of theirphysical properties with those of the stable forms, three formulaehave been put forward by Auwers and Allardt for acylindazoles,of which I11 is regarded as unlikely, I1 is considered probable forboth forms from the results of spectrochemical examination, whilstI may be necessary to explain the colour of some of the labileisomerides. The isomerism is regarded as steric, which introducesa difficulty with regard to 11, since isomerism in this case involvesconsiderable strain. Formula I has the further advantage thathydrogen chloride should add on in position 1 with difficulty inthe case of one isomeride owing to the proximity of the acyl group,and this does occur, hydrogen chloride splitting off the acyl group.CH CH CH(1.) (11.) (111.)It has, however, been pointed out that formula I is not com-patible with the assumption, previously made, that stereoisomer-ism in this group is due to the presence of an asymmetric tervalentnitrogen atom. The only other possible explanation (position 3being impossible in view of new experimenta,l evidence) is thatone of the forms contains the acyl group in position 1, a possibilityalready considered but rejected by Auwers on the ground that" l-acetylindazole " obtained from o-aminobenzaldoxime is notidentical with either the labile or stable form of acetylindazolenow under discussion. Re-examination of this " 1 -acetylindazole "indicates, however, that it is really 4 : 5-benzo-7-methylhept-1 : 2 : 6-oxadiazine, C,H,<N-Cie>Q. C(0H)'N-J. Meisenheimer and A. Diedrich, Ber., 1924, 57, [BJ, 1715; A,, i, 1347;compare K. von Auwem, ibid., p. 1723; A., i, 1348. T. A. HENRY

ISSN:0365-6217    

DOI:10.1039/AR9242100055

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THE story of a year's progress in analytical chemistry must ofnecessity be somewhat disconnected, for analysis is not an end initself, but only the chief means by which the arms of all the otherbranches of chemistry are attained. Hence, a report, if it is to beof general use for the purpose of reference, must cover a very wideground and be classified in such a way as to show rapidly whichof the new methods outlined are likely to be applicable for specialpurposes. As space is no longer available for the inclusion of allthe modifications of methods devised during the preceding year, ithas been found necessary to make the selection mainly from thoseprocesses in which new principles have been applied, or in which amore trustworthy procedure has been described.Physical Methods.It has been ascertained that the rate of diffusion of fatty acids inalcohol through a collodion membrane decreases with the increasein the molecular weight of the fatty acids, and this principle has beenadapted to the detection and separation of mixtures of acids, suchas stearic and lauric acids.lVarious forms of apparatus for filt'ration through membranes(ultra-filtration) have been devised, the filter being made of porousearthenware coated on the inside with a layer of collodionY2 or ofunglazed porcelain or cellulose acetate.3 These filters are suitablefor the separation of electrolytes from colloidal solutions, and forthe filtration of colloidal silver, hzemoglobin, etc.A method of detecting the presence of a mixture of constant boilingpoint consists in fractional distillation a t a different pressure until asufficient quantity of the constituents has been separated to leave amixture of constant boiling point with a different comp~sition.~A rapid method of determining sulphur in the form of a solublesulphate depends upon its titration with barium chloride solutionin a Dewar vacuum tube, measurement of the temperature a tintervals, and plotting the readings against the volume of bariumA.Heiduschka and J. Ripper, 2. Elektrochem., 1023, 29, 552; A., ii, 73N. Bechhold and L. Gutlohn, 2. angew. Chem., 1924, 37, 494; A!, ii, 621.L. Zakarias, &id., 425; A., ii, 622.T. R. Briggg, J. Physical Chem., 1924, 28, 644; A., ii, 776.15152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.chloride solution.The end-pint is indicated by a break in thecurve. 5As usual, the principal contributions to this branch of analyticalchemistry have been extensions of optical *methods. A spectro-photometric method of determining hydrogen-ion concentratioiihas been based upon the observation that the wave-lengths of theabsorption bands in a solution containing an indicator are notlaltered by a change in the hydrogen-ion concentration, but that theintensity of Ebsorption (height) of the bands is changed and can bemeasured 2nd compared with that in a buffer solution containingthe same indicator.6 Another spectrophotometric method consistsin determining the degree of colour transformation of an indicator,which, in the case of two-colour indicators, may be obtained fromthe ratio of the intensities of absorption a t two wave-lengths nearthe maxima of the respective absorption bands.’Methods for the identification of phenols, especially in medicinalpreparations, have also been devised,* and tables have been con-structed showing the relationship between the concentrztion ofsolutions of arabinose or xylose and the extinction coefficient ofthe band of maximum absorptior, given in amyl alcohol solutionby the blue pigment formed on treating these pentoses with Bid’sorcinol reagent .9Mention may also be made of the use of colloidal poles of gelose(from agar-agar) for observing the emission spectra of dilute solutionsand their application to the detection of metals.l*Further work has been done on the application of fluorescencephenomena as a means of identifying a number of organic com-pounds, such as quinol, pyrocatechol, and salicylic acid.Thesubstance is cxposed to ultra-violet light from a mercury vapour1amp.llA new optical method of determining starch consists in treatingtwo portions of a mixture of starch and water with diastase, onewith and the other without gelatinisation by heat, filtering the twoliquids, and comparing the filtrates in the interferometer. Theresults are somewhat lower than those obtained by chemicalmethods .12P. M. Dean and 0. 0. Watta, J . Arner. Chem. SOC., 1924, 46, 855; A.,W. R. Brodie, ibid., 581; A . , ii, 346.7 W. C. Holmes, ibid., 627; A., ii, 346.8 S.Palkin and H. Wales, &id., 1485; A., ii, 630.9 G. Scheef, Bwchern. Z., 1924, 147, 94; A., ii, 632.10 J. Errera, Bull. SOC. chim. Bely., 1924, 33, 449; A., ii, SOB.l1 E. Bayle and R. Fahre, J. Pham. Chim., 1924, 29, 535.lr 0. Wolff, 2. angew. Chem., 1924, 37, 206; A., ii, 506.ii, 421. Compare Ann. Report, 1922, 19, 166ANALYTICAL CHEMISTRY. 153There have been several contributions to the methods of ushgthe X-ray spectrum in qualitative and quantitative analysis, andit has been shown that, when a sufficiently long exposure to thephotographic film is given, as little as 1% of an element in 1 mg. ofa mixture can thus be detected.13 For quantitative work thesubstance may be imbedded in an indifferent material such asgraphite, together with a standard substance, and the ratio betweenthe intensities of the lines of the two substances is then determined.The method is only applicable, however, to solid elements heavierthan sodium.14Gas Analysis.Among the new forms of apparatus devised for the analysis ofgases is a spiral washing bottle which insures intimate contactbetween the gas and the liquid, and so promotes the absorption.16A device of a similar type has been used for separating hydrogenperoxide vapour from ozone, the mixturc being passed through aspiral chilled in a mixture of ether and solid carbon dioxide, withthe result that only thc peroxide is condensed.Alternatively, bypassing the gaseous mixture through dilute acidified permanganatesolution, the peroxide is destroyed, and the ozone can be deter-mined by absorption in potassium iodide solution.l6For the analysis of mixtures of nitric oxide and nitrogen peroxidethe gas is shaken with concentrated suiphuric acid, which absorbsequal moleuclar proportions of each gas, forming nitrogen trioxide,the amount of which is determined by means of the nitrometer.The excess of nitric oxide in the residual gas is determined by meansof the nitrometer after oxidation of both gases with potassiumbr0rnste.l'An investigation of various absorbents for carbon monoxide hasshown that the most efficient is a mixture of cuprous chloride, finepumice, and powdered soda-lime.ls The compound of cuproussulphate and ethylene described by Damiens,lg forms, when sus-peiided in sulphuric acid, a good absorbent for carbon monoxide, butif also absorbs oxygen, ethylene, and acetylene, which must thereforebe removed before the absorption20 These three gases are absorbedless readily by another new reagent for carbon monoxide preparedby shaking a suspension of cuprous oxide in sulphuric acid €orl3 D.Coster, Chem. Weekbblad, 1934. 21, 59: -4.. ii, 199.l4 H. Stintzing, 2. physikal. C'hern., 1924, 108, 58; A., ii, 216.l5 L. H. Milligan, Ind. Eng. Chem., 1924, 16, 889; A., ii, 776.l6 M. Bamberger and K. Trautzl, 2. anal. Cltenz., 1924, 64, 9; A., ii, 563.l7 A. Klemenc and K. Mula, 2. anorg. Chem., 1921, 134, 208; A., ii, 498.A. Piutti, Rend. Accad. Pis. Mat. Napoli, 1922, 28, 91; A., ii, 59.A. Damiens, A., 1921, i, 1105.Idem, Compt.rend.,:,1924, 178, 849; A., ii, 567154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.several hours with a phenolic substance, such as p-naphthol, andfiltering the solution.21A method of determining carbonyl chloride in gas mixtures con-taining hydrogen chloride and carbon dioxide consists in shakingthe gas with water to absorb the hydrogen chloride, and then with ameasured excess of standard potassium hydroxide solution (whichabsorbs both carbon dioxide and carbonyl chloride), and finallydetermining the carbonyl chloride by adding excess of hydro-chloric acid and titrating the excess with standard barium hydroxidesolution. The reaction upon which the method is based isCOCI, +4KOH=2KC1+K,C0,+2H20.22I n determining organic vapours, such as benzene, by adsorptionwith active charcoal it is necessary to take into account the fact thatthe charcoal a t first retains a large proportion of benzene aftersteaming a t 130°, but that afterwards this loss becomes constant,and an average of 99.6 yo is then expelled by the stearn.,3 The mostsatisfactory results are obtained when the steaming of the char-coal is carried out in the same U-tube in which the benzenewas ads0rbed.2~Agricutturab Analysis.A new method of determining humic matter in soils depends upona colorimetric comparison of the hydrochloric acid extract of thesoil, after treatment with excess of alkali, with a standard solutionof Acidum Huminicum (Merck) under parallel c0nditions.~5The adsorptive method of det,ermining colloidal matter in soilshas been shown to give results which, with the application of acorrection, agree closely with those obtained by microscopicalexamination.*G The percentage of colloida.1 matter is expressed interms of the ratio of the adsorption per g.of the soil to that of theextracted colloids, multiplied byThe difficulty of obtaining a clear solution of soil for the colori-metric determination of the hydrogen-ion concentration may beovercome by dialysing the mixture of soil and water for 24 hoursthrough a porous membrane. The results then obtained were foundt o be more accurate than those given by the electrometric method.2*21 P. Lebeau and C. BedeI, Compt. rend., 1924, 179, 108; A., ii, 627.z2 G. Bredig and A.von Goldenberg, Gas-u. Wasserjach., 1924, 67, 400;23 E. Berl and E. Wachendorff, 2. angew. Chem., 1924, 37, 205; A., ii, 505.24 F. Fischer and C. Zerbe, &id., 483; A., ii, 630.26 T. Eden, J. Agric. Xci., 1924, 14, 469; A., ii, 796.26 Compare Ann. Report, 1923, 20, 160.27 P. L. Gile and others, U.X. Dept. Agric. Bull., 1924, 1193; A., ii, 796.28 I. M. Kolthoff, Chern. Weekblad, 1923, 20, 675; A,, ii, 199.Ann. Report, 1923, 20, 161.A., ii, 701.ComparANALYTICAL CHEMISTRY. 155On the other hand, comparative determinations by the electro-metric method and by a colorimetric method (with the use ofmethyl-red, bromophenol-blue, bromocresol-purple, and methyl-red), in which the aqueous suspensions of the soil were separatedcentrifugally, gave results differing by not more than 0.19 p,.29Notwithstanding criticisms of the untrustworthiness of “ citricsolubility ” as a criterion of the fertilising power of mineral phos-phate~,~O evidence of the difference in the behaviour of variousnatural phosphates in the test has once more been put forward, andit is claimed that the ratio of the amount of phosphoric acid solublein 2% citric acid solution to that of the total phosphoric acid affordsa measure of the fertility of a ~ 0 i 1 .3 ~ A potentiometric method ofdetermining this ‘‘ citric acid ratio ” has been de~ised.3~One difficulty in the way of obtaining accurate results in thephenoldisulphonic acid method of determining nitrates is theadsorption of nitrate by the filter-paper 33 or by animal charcoal.This may be largely overcome by precipitating copper hydroxidefrom calcium hydroxide and copper sulphate in the soil suspension,the extract being thereby decolorised without losing more thantraces of nitrate.84Organic Analysis.Qualitative.-It has been shown that a solution of magenta andsulphurous acid (Schiff ’s reagent) will give a coloration with un-diluted ethyl alcohol, but not with dilute (5-10%) alcohol.Thetest will detect 0.00005 C.C. of 37% formaldeyhde in 5 C.C. of dilutealcohol. A still more sensitive test for formaldehyde depends uponthe purple coloration obtained with morphine sulphate and sulphuricacid.35 Both formaldehyde and acetaldehyde give a white precipi-tate with Bial’s reagent (orcinol, ferric chloride and hydrochloricacid), but the two precipitates may be distinguished by their be-haviour on heating and on the addition of alkali.36 A micro-chemical method capable of detecting 0.001 mg.of acetaldehydein fruits has been based on the formation of characteristic crystals ofacetaldehyde-p-nitrophenylhydrazone, b ut the test is not dis-*@ R. M. Barnette, F. c . Gerretsen, D. J. Hissiak, and J. van der Spek,Chem. Weekbhd, 1924, 21, 145; A., ii, 347.so Compare Ann. Report, 1922, 19. 169.51 G. Andre and H. Copaux, BUZZ. SOC. chim., 1924, [iv], 35, 1113; A.,ii, 871.H. Copaux and J. Daric, ibid., 1115; A., ii, 872.a3 Compare Ann. Report, 1923, 20, 161.34 H. J. Harper, Ind. Eng. Chem., 1924, 16, 180 ; A , , ii, 274.55 J. L.Mayer, J . Amer. Pham. ASSOC., 1923, 12, 698; A., ii, 210.16 5. B. Sumner, J . Amer. Chem. Soc., 1923, 45, 2378; A., ii, 70156 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tinctive, since other aldehydes and ketones yield analogous crystal-line compounds.37An alcoholic solution of vanillin can replace salicylaldehyde as areagent for acetone ; it produces a red ring above acetone to whicha fragment of solid sodium hydroxide has been added.38 Bothacetone and acetoacetic acid give a coloration with sodium nitro-prusside, but only acetoacetic acid gives a colour reaction with ferricchloride.39A useful test for chloroform and chloral hydrate in amounts upto 0.005 mg. has been basedupon the fact that compoundscontainingthe group CX, (in which S represents a halogen) give a red colorationwhen heated with sodium hydroxide solution and pyridine.40The ferrous tartrate test for tannins and their derivatives 01 isnot specific for tanilins, but a solution of a mixture of neutral ironammonium citrate and ammonium citrate apparently gives aprecipitate only with tannin and not with gallic acid or phlobo-tannin.42 A sensitive modification of the gold-beater’s skin testfor tannins 43 has been devised, and it has been shown that srtbe-quent treatment of the stained skin with hydrochloric acicl e m b k sphlobaphens to be distinguished from tannin~.~4 Osmium tetroxidecan be used as a reagent in the test, but is less sensitive than ferroussulpha te.45A reagent that will distinguish resorcinol from other phenolsconsists of a mixture of sodium nitroprusside, sodium acetate andammoilia solutions ; it gives with resorcinol a blue-green coloration,changing to yellow on the addition of excess of sodium hydroxide.46The reaction with Hofmann’s-violet decolorised with sulphuricacid, which was put forward by Guareschi as specific for proteins,has been shown to be produced by nit’rogenous compounds in generalof slight acidity or allralinity.47Quantitative.-Several contributions have been made to themethods for the ultimate analysis of organic compounds.In thecase of volatile compounds, a convenient method is to conductthe vapour into the combustion tube by means of a current of warmC. Griebel, 2. Untem. Naltr. Qenussm., 1924, 47, 438; A., ii, 791.E.J. Bigwood and W. L. Ladd, J . Biol. Chem., 1923, 58, 347; A.,B8 H. Leffmann, Anzer. J . Pham., 1924, 96, 507; A., ii, 791.ii, 210.40 J. H. Ross, ibid., 1923, 58, 641; A., ii, 352.41 Compare Ann. Report, 1923, 20, 165.42 A. H. Ware, Analyst, 1924, 49, 467; A., ii, 789.43 E. Atkinson and E. 0. Hazelton, Biockem. J., 1932, 16, 516; A., 1922,44 P. H. Price, Analyst, 1924, 49. 25; A., ii, 209.46 Idem, aid., 336; A., ii, 574.46 Cazeneuve, Ann. Chim. Analyt., 1924, [ii], 6, 43; A., ii, 356.4 1 GI. Lo Priore, Chem. Zentr., 1924, i, 947; A., ii, 796.ii, 793ANALYTICAL CHEMISTRY. 157oxygen.48 For determining carbon by the wet method, the sub-stance may be heated with an excess of potassium persulphate inaqueous solution, and the czrbon dioxide dried and ~eighed.4~Another rapid method is to oxidise the organic substance by meansof permanganic anhydride in sulphuric acid, and to determinevolumetrically the carbon dioxide pr0duced.5~ The wet method hasalso been made applicable to nitrogen, the substance being digestedwith sulphuric acid and potassium dichromate, and the nitrogendetermined as in the Kjeldahl process.Chlorides nust be removedin the form of hydrogen chloride by aeration prior to the additionof the dichromate, or the results will be too This oxidationmethod with ili:al!rornate has also been adapted to micro-determina-tion of carbon and nitrogei1.5~The method of determining halogens by combustion in a currentof oxygen over platinised asbestos and absorption of the halogen bysilver powder has been claimed t o give good results with nitrogenoussubstances, notwithstanding statements to the contrary. If sulphuralso is present, the products of combustion are made to pass oversodium carbonate a t 400--500", and halogen is determined in oneportion and sulphur in the other.53 A new method consists inheating the organic substance in a current of a mixture of hydrogenand ammonia, and determining the halogen 'volurnetrically in theammonium halide produced.54 Or the combustion may be carriedout in a current of oxygen in the presence of, but not in contact with,ferric chloride, and the products led into an alkali sulphide solution,which is afterwards acidified and the halogen titrated.65 Fluorinemay be determined by heating the substance with potassium a t 400°,and titrating the potassium fluoride conductometrically withcalcium chloride.56Magnesium perchlorate trihydrate is recommended as a readily-prepared and stable substitute for calcium chloride as an absorbentin organic analysis, as well as for phosphoric oxide in the analysisof steel by omb bust ion.^^46 M. E.Carrikre and C. Leenhardt, BUZZ. Soc. chim., 1924, [iv], 35, 1206;A., ii, 869.4' A. Franz and H. Lutze, Ber., 1924, 67, [B], 768; A., ii, 500.60 J. F. Durand, Compt. rend., 1924, 178, 1193; A., ii, 500.61 A. K. Anderson and H. S. Schutte, J . BWZ. Chem., 1924, 61, 57; A.,52 H. Dieterle, Arch. Phamt., 1924, 282, 35; A., ii, 567.59 F. Arndt, Ber., 1924, 57, [B], 763; A., ii, 497.64 H.ter Meulen and J. Heslinga, Rec. trav. chim., 1923, 42, 1093; A,,55 J. Heslinga, $id., 1924, 43, 181; A., ii, 419.68 J. Piccard asd C. Buffat, Helv. Chim. Acta, 1923. 8. 1047; A., ii, 122.57 G. F. Smith, M. Brown, and J. F. Ro~s, Ind. Eng. Chem., 1924,16, 20;ii, 699.ii, 55.A., ii, 198158 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It has been shown that amino- and carboxyl groups in amino-acids, etc., can be determined by a series of titrations to different pavalues, the point to which the neutralisation is to be carried beingfound by reference to the titration curves of the acid in question.58In titrating the amino-group, the solution is neutralised to phenol-phthalein, and then titrated with hydrochloric acid, with methyl-redas indicator.I n the case of arginine, the carboxyl group aiid oneof the amino-groups do not react.59 The methods of acidimetryappear to be practicable, not only with amino-acids, but also withalbumin, gliadin, casein, and gelatin, and the curves obtained withthe products of hydrolysis of these proteins indicate that, the originalsubstances may thus be characterised.60A modification of the dichromate method of determining glycerolhas been deivsed, and has shown that the curd fibres of sodiumpalmitate adsorb glycerol negatively a t the ordinary temperature,even in the absence of sake1Among the few new contributions to analytical methods for oilsand fats are two methods for determining the acetyl value : one bydetermining the increase in weight after acetylation, and the otherby using chloroacetyl chloride for the acetylation, and calculatingthe acetyl value from the amount of chlorine used, this being deter-mined volumetrically.62 It has been shown that linseed oil, onbromination, yields two crystalline bromides of mixed glycerides,and a method of examining linseed oil has been based on the deter-mination of the bromide more insoluble in ethyl acetate.63 One ofthese bromides has been prepared independently, and its compositionas the bromide of a-dilinolenin-a-linolin has been confirmed.64Tartaric acid may be determined by oxidising it with potassiumiodate and sulphuric acid :C4H606 + 2KI0, + H2S04 = K2S04 + I, + 4c02 + 4H20.The liberated iodine is expelled by boiling, and the excess of iodateis determined iodometrically.65It has been found that the ferrocyanides of sodium, potassium,or calcium yield an insoluble white precipitate of benzidine hydro-f errocyanide, (C,,H,,~,),,H,Fe(CN),, on treatment with a benzidine68 L.J. Harris, PTOC. Roy. SOC., 1923, [B], 95, 440; A., ii, 75.5Q Idem, ibid., 1924, [B], 95, 500; A., ii, 355.60 P. Hirsch, Biochem. Z., 1924, 147, 433; A., ii, 795.61 H. B. Bennett, J., 1924, 125, 1971.62 R. Biazzo, Chem. Zentr., 1924, i, 2030; A., ii, 708.63 H. Tom, Analyst, 1924, 49, 77; A., i, 365.64 A. Eibner and K. Schrnidinger, Chem. Umschau, 1923, 30, 293; A.,86 R. Strebinger and J. Wolfram, Oestew. Chem. Ztg., 1923, 26, 156; A.,ii, 131.ii, 73ANALYTICAL CHEMISTRY. 159salt, and that this reaction can be used for determining ferro-cyanides either gravimetrically by determination of the iron orvolumetrically with the use of sodium hypobromite as an outsideindicator. 66An attempt has been made to extend Mitchell's ferrous tartratemethod of determining the pyrogallol tannins 67 to the pyrocatecholtannins, and i t has been found that, whilst good results could beobtained in comparing pyrocatechol, protocatechuic acid, andcatechins by themselves, the method failed when used for com-paring them with one another.It was also established that theformation of a violet coloration with the reagent depends uponthe presence of two hydroxyl groups in the ortho-position.s8 Itwa.s afterwards shown that by suitable adjustment of the hydrogen-ion concentration of the tannin solution the method is also applicableto the pyrocatechol tannins, the apparent failure with them beingdue to the fact that they differ more widely than the pyrogalloltannins in the pH values a t which their maximum intensity ofcolour is given.69 It has also been found that osmium tetroxide canbe used for the colorimetric determination of both groups oftannins. 70 The ferrous tartrate colorimetric method has been shownto give trustworthy results in determining the amount of gallicacid produced in the hydrolysis of gallotannin by tanna~e.7~For determining tannin in plant-tissue, a colorimetric methodhas been devised in which the reagent is prepared by boiling togethersodium tungstate, arsenic acid (As,O,), and hydrochloric acid.Asolution of pure gallotannin (freed from gallic acid) is used as thestandard for the colorimetric compari~on,7~ and therein lies theweak point of the method, for " pure " gallotannin may containvariable proportions of glucose or practically 110118.73A modification of the colorimetric method of determining sugarsby means of picric acid has been applied to the determination ofcarbohydrates in plants, and has been shown to give more accurateresults with small amounts of reducing sugars and sucrose thaneither the volumetric or the reducing method.74 Starch can alsobe determined by the same method after hydrolysis to dextrose6 6 W. J. Cumming, J., 1924, 125, 240.6 7 C. A. Mitchell, Analyat, 1923, 48, 1; A., 1923, ii, 188.6 8 P.H. Price, ibid., 1924, 49, 361; A , , ii, 707.69 S. Glasstone, SOC. Public Analysts, Dec. 5, 1924.io C. A. Mitchell, Analyst, 1924, 49, 162; A , , ii, 356.51 W. N. Nicholson and D. Rhind, ibid., 505; A., ii, 875.72 P. Menaul, J . Agric. Res., 1923, 26, 257; A,, ii, 360.73 Compare Ann. Report, 1923, 20, 166.74 W. Thomas and R. A. Dutcher, J . Anter. Chem. SOC., 1924, 48, 1662;A., ii, 630160 ANNUAL REPORTS ON THE PROGRESS OF UHEMISTRY.and maltose by means of taka-diastase; 75 or fresh malt solutionmay be used for the hydrolysis.76 As a standard for comparisonin this method, the use of a O-OSyO solution of dextrose or a 0.07670solution of sucrose in saturated picric acid solution is suggested.The intensity of coloration is not proportional to the dilution,and it is therefore necessary to dilute by a standardised method.Correction factors are also required, since the degree of colorationis not proportional to the amount of sugar."It has been shown that under definite conditions for time, tem-perature, and proportions of iodine and alkali the iodometric methodgives quantitative results in the oxidation of dextrose, lactose,sucrose, and la3vulose.78 An iodometric method has also beendevised for determining the nitrogen in 0sazones.7~ By heatingdextrose with an excess of phenylhydrazine in acetic acid, it isquantitatively converted into its osazone, which may be determinedby reduction with titanous chloride and titration of the excess ofthis with crystal-scarlet.The method is also applicable to othercarbohydrates yielding osazones under the same conditions.80The polarimetric constants of lactose have been redeterminedand a formula for its determination has been devised,*l and apolarimetric method of determining raffinose in sugars worked out.gzDetermination of sugar in urine by means of Fehling's solution,with methylene-blue as internal indicator, has been shown to givemore accurate results than Pavy's method.83The furfuraldehyde yielded by pentoses and pentosans may beaccurately determined in acid solution by the use of potassiumbromate in the presence of potassium bromide.84 A colorimetricmethod, accurate t o & 2.5y0, has also been devised; it dependsupon the coloration given by furfuraldehyde with aniline andacetic acid.85A method for determining lignin has been based on its insolu-75 W.Thomas, J . Arner. Chem. Soc., 1924, 46, 1670; A., ii, 635.73 M. R. Coe and G. L. Bidwell, J . ASBOC. 08. Agric. Chern., 1924, 7, 297;7 7 J. Willaman and F. R. Davison, J. Agric. Re%., 1924, 28, 479; A.,78 C. L. Hinton and T. Macara, Analyst, 1924, 49, 2; A., ii, 209.7w D. R. Nanji, Biochern. J., 1923, 17, 761; A., ii, 209.80 E. Knecht and E. Hibbert, J., 1924, 125, 2009.81 A. L. Bacharach, AnaZyst, 1923, 48, 521 ; A., ii, 72.ea E. Saillard, Compt. rend., 1924, 178, 2189; A., ii, 632.83 J. H. Lane and L. Eynon, Analyst, 1924, 49, 366; A., ii, 707.84 N. C. Pervier and R. A. Gortner, Ind. Eng. Chem., 1924, 15, 1255; A.,85 G. E. Youngburg and G.W. Pucker, J . BioZ. Chem., 1924, 61, 741 ; A.,A., ii, 429.ii, 789.ii, 71.ii, 876ANALYTICAL CHEMISTRY. 161bility in a solution of phosphorus pentoxide in hydrochloric acid,which will dissolve wood cellulose.86The fact that pyridine is quantitatively precipitated by silico-tungstic acid has been made the basis of a method for its deter-mination, especially in the presence of nicotine.87It has been proved that the red coloration in Jaffe’s reaction fordetermining creatinine is due to the formation of a red tautomerideof creatinine picrate. 88A colorimetric method of determining adrenaline depends uponits forming a red coloration when treated successively with sul-phanilic acid, nitrous acid, a,nd ammonia.89Mention ma,y also be made of a colorimetric method of deter-mining diastase, which consists in digesting the enzyme solutionwith excess of erythrodextrin, determining the unaltered dextrinby adding iodine solution and ammonium sulphate, and comparingthe colour with a standard.90Inorganic Analysis.Qualitative.-All the common heavy metals form pyridine-thio -cyanate compounds, with the general formula M(CNS)27(C5H5N)2,91and some metals form analogous compounds with antipyrine(cadmium) and pyramidone ( copper).92 The pyridinethiocyanatecompounds of zinc and cadmium form distinctive crystals, by whichthey can be identified.93 Diphenylcarbazide can also be used as aspecific reagent for certain metals (mereury, copper, cadmium, andmagnesium) by varying the conditions in each case, e.g., by addinghalogen salts.94The use of czesium chloride as a general microchemical reagenthas been developed, a large number of metals forming characteristicdouble chlorides with it.95 Other useful microchemical reagentsinclude pyrogallol for tervalent antimony, benzoinoxime for copper,and benzidine for manganese and phosphoric acid.96 Potassium,ammonium, and magnesium may be distinguished by the differentforms of the crystals they yield on treatment with sodium benzene-s ~ l p h o n a t e .~ ~86 H. Wenzl, Papierfabr., 1924, 22, 101 ; A,, ii, 428.8’ F. Mach and F. Sindlinger, 2. angew. Chem., 1924, 37, 89; A., ii, 357.t 8 I. Greenweld and J. Gross, J . BWE. Chem., 1924, 59, 601; A., ii, 508.o9 H. Friend, ibid., 1923, 57, 497; A., ii, 76.I.Cohen and E. C . Dodds, Brit. Med. J., 1924, I, 618; A., ii, 636.s1 Compare Ann. Report, 1923, 20, 16s.e2 I. M. Kolthoff and H. Hamer, Pham. Weekbhd, 1924,61,1222 ; A., ii, 873.93 Idem, Mikrochemie, 1924, 2, 92; A., ii, 785.94 I. M. Kolthoff, Chem. Weelzbhd, 1924, 21, 20; A., ii, 124.O5 E. H. Nicloux, Mikrochemie, 1924, 2, 108; A., ii, 783.S6 F. Feigl, Milcrochernie, 1923, 1, 74; A., ii, 206.9’ L. Rosenthaler, ibid., 1924, 2, 29; A., ii, 782.REP.-VOL. XXI. 162 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Several new tests for individual metals have also been described.Thus, an alcoholic solution of guaiacum resin may be used as asensitive reagent for copper.98 That metal also gives a red color-ation with an alcoholic solution of aloin and a green colorationwith a solution of benzidine.99Stannous chloride will reduce mercuric chloride to metallicmercury in presence of aniline, and tin may thus be detected whenpresent with the other ordinary metals.The same reaction,applied by means of stannous chloride paper, may be used for thedetection of mercury.l I n the absence of copper, ferrous saltsgive a bluish-green coloration with 2 : 4-dinitroresorcinol, and thecolour becomes bright green if ferric salts are present.2A test that will detect 1 part of cobalt in 830,000 parts consistsin treating the acid solution with sodium acetate and dimethyl-glyoxime, filtering off any precipitated nickel, and adding sodiumsulphide to the filtrate. A violet coloration, due to the formationof a compound, [CMe( :NOH)],:::Co(***H,O)(***NH,):S, indicatescobalt .3A very sensitive test for nickel depends upon the formation ofa red compound, [CMe( :N*OH)CMe:NO*],NiO, on boiling thesolution with concentrated ammonia, lead dioxide, a few drops ofsodium hydroxide solution, and alcoholic dimethylglyoxime. Thefiltrate will vary from dark red to reddish-yellow, according to thequantity of nickel present.* Another test for nickel and cobaltconsists in adding an excess of sodium hydrogen carbonate, followedby a few drops of bromine water, to the solution.A green color-ation indicates nickel, and the precipitate turns black on heatingif cobalt is present.Thiocarbamide and hydrochloric acid give a blue-green color-ation with ruthenium.Osmium also gives a coloration with thereagent, but may be distinguished by its forming a red solutionon the addition of thiocarbanilide.6Several new colour reactions of zirconium have been described.One is that zirconium yields coloured complex salts with p-naphtholor p-nitroso-a-naphthol ; another consists in the production of areddish-violet coloration (not discharged by excess of hydrochloricQ* R. Fleming, Analy8t, 1924, 49, 275; A., ii, 500.99 L. Rosenthaler, Mikrochemie, 1924, 2, 121; A., ii, 785.N. A. Tannaer, 2. anorg. Chem., 1924, 133, 372; A., ii, 671.2 M. Goldstuck, Chem. Ztg., 1924, 48, 629; A., ii, 703.3 F. Feigl and L. von Tustanowska, Ber., 1924, 57, [BJ, 762; A., ii, 504.F. Foigl, ibid., 758; A., ii, 504.C.C. Palit, Clzem. New8, 1924, 128, 293; A . , ii, 426.L. Wohler and L. Metz, 2. anorg. Chem., 1924, 138, 268; A., ii, 874.I. Bellucci and G. Savola, Chem. Zentr., 1924, i, 2531; A., ii, 788ANALYTICAL CHEMISTRY. 163acid) with alizarinsulphonic acid.* Distinctive microchemicalreactions of zirconium and some other elements with picric acidand with turmeric have also been de~cribed.~Picrolonic acid forms characteristic crystals with calcium andcan be used as a sensitive microchemical reagent for that metal.I0As little as 0.001 mg. of magnesium in 1 C.C. can be detected bythe bright blue coloration which it gives with an alcoholic solutionof 1 : 2 : 5 : 8-tetrahydro~yanthraquinone.~~I n view of the lack of sensitiveness of the pyroantimonate testor sodium, it is recommended that a 50% alcoholic solution ofmagnesium uranyl acetate should be used instead ; it is not affectedby salts that interfere with the older test.12Several colour reactions have been adapted to the detection ofnitric and nitrous acids. A sulphuric acid solution of diphenyl-diethylcarbamide gives an intense red coloration with both acids.13An aqueous solution of 2 : 4-diamino-6-hydroxypyrirnidine or ofone of its salts is a sensitive reagent for the zone test for nitratesin presence of sulphuric acid.l4Reference may also be made to a method of distinguishingbetween sulphurous and thiosulphuric acids, based on the pro-nounced difference in their decolorising action upon aurin , corallin,or rosolic acid.15Quantitative.-By the use of a buffer solution composed of phos-phoric, phenylacetic, and boric acids of a total normality of O-lN,it is possible, by adding 0-1N-alkali or strong acid, to obtain solu-tions with a p , range from 2.5 to 11.5.16 Tables have also beenconstructed for determining the pa values of alcoholic solutions,with the use of several one-colour indicat0rs.l' A mixture ofcresol-red and thymol-blue indicates sharply the half -neutralisationpoint in carbonate titrations, which can then be completed afterthe addition of methyl-orange or bromophenol-blue.ls Of theazo-indicators with asymmetric nuclei, the basic dyestuffs have beenshown by means of the spectrophotometer to be the most, and thecarboxyl acids the least sensitivc.lg An indicator having approxi-J.H. de Boer, Chem. Weekblad, 1924, 21, 404; A., ii, 705.F. Steidler, Mikrochemie, 1924, 2, 131; A., ii, 788.lo J. Kisser, ibid., 1923, 1, 25; A., ij, 124.l1 F. L. Hahn. H. Wolf. and G. Jager, Ber., 1924. 57, [B], 1394; A., ii, 784.l2 I. M. Kolthoff, Pharm. Weekbbd, 1923, 60, 1251; A., ii, 60.l3 L. Desvergnes, Ann. Chim. anal., 1924, [ii], 6, 102; A., ii, 565.l4 H. Wolf and E. Heymann, 2. angew. Chem., 1924, 37, 195; A., ii, 423.l5 E. Pittarelli, Arch. Farm. sperim., 1924, 38, 13 ; A., ii, 777.l6 E. B. R. Prideaux and A. T. Ward, J., 1924, 125, 426.l7 L. Michaelis and M. Mizutani, Bwchem. Z., 1924, 147, 7 ; A., ii, 623.l8 S. G. Simpson, Ind. Eng. Chem., 1924, 16, 709; A., ii, 627.A. Thiel and F. Wiilfken, 2.anorg. Chem., 1924, 136, 393; A., ii, 622.a164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.mately the same applicability as litmus may be prepared byseparating the anthocyanin from an aqueous extract of red cabbage.20Prussian blue is another indicator that can be used in titrating anacid with an alkali.21 In this connexion, attention may be directedto the use of a logarithmic method of construct'ing titration curves,whereby the degree of neutralisation of a mixture of an acid and abase can be calculated.22Among the indicators recommended for special determinationsare diphenylamine for use in the titration of iron with dichromate23or permanganate solution,24 and alkali molybdates 25 and potassiumpermanganate 26 as indicators for the titration of zinc with ferro-cyanide.The use of various organic dyes (fluorescein, eosin, etc.) as indi-cators for the titration of silver- and halogen-ion has been recom-mended,27 and has been shown to involve a smaller adsorptiveerror than the use of potassium chromate.%Liquid amalgams have been used as reducing agents in volumetricmethods.For example, iron and vanadium may be determinedby reducing the ferric iron in one part of the solution with bismuthamalgam, and the vanadium in another portion with zinc amalgam,and titrating both portions with permanganate. Molybdenumand iron may be determined in a similar manner.29 Liquid zincamalgam has also been used as the reducing agent for the volumetricdetermination of phosphoric acid after precipitation as uranylammonium phosphate.30Further extensions of the hydrolytic methods of precipitation 31have been described.For example, titanium may be separatedfrom aluminium by precipitating both metals with ammonia,dissolving the precipitate in sulphuric acid, diluting the solutionto a specified pH value, and heating it a t 100" t o precipitate thetitanium.32 A hydrolytic method has also been adapted to thequantitative separation of bismuth, as a basic nitrate, from lead,copper, and cadmium,33 and t o the determination of barium by20 V. Matula, Chem. Ztg., 1924, 48, 305; A., ii, 496.2 1 K. Jellinek and W. Kiihn, 8. anorg. Chem., 1924, 138, 81; A., ii, 693.22 A. Thiel, ibid., 1924, 135, 1; A., ii, 496.23 J. Knop, J . Amer. Chem.SOC., 1924, 46, 263; A., ii, 351.24 T. W. W. Scott, ibicE., 1396, A., ii, 787.25 K. Fajans and 0. Hassel, 2. Elektrochem., 1923, 29, 450; A., ii, 60.26 K. Jellinek and W. Kuhn, 8. anorg. Chem., 1924, 138, 109; A., ii, 695.2 7 K. Fajans and 0. Hassel, 8. anorg. Chern., 1924, 137, 221; A., ii, 776.28 W. Bottger and K. 0. Schmidt, ibid., 246; A., ii, 776.2D K. Someya, &id., 1924, 138, 291; A., ii, 787.30 S. Saito, J . Chem. SOC. Japan, 1924, 45, 74; A., ii, 780.31 Compare Ann. Report, 1923, 20, 169.82 L. Kayeer, 2. anurg. Chem., 1924, 138, 43; A . , ii, 704.G. Luff, 2. and. Chem., 1923, 63, 330; A., ii, 278ANALYTICAL CHEMISTRY. 165precipitation as barium pyrobora te and hydrolysis of the pre-cipitate to barium hydroxide.3For the separation of the metals of the ammonium sulphidegroup, the use of hydrogen sulphide under pressure offers manyadvantages, and conditions for the quantitative precipitation ofthese metals from their solution in sulphuric acid have been ascer-tained.35 Another modification in the use of hydrogen sulphide isits application in a nascent state for the precipitation of platinumand copper, it precipitate free from iron being thus obtained.36When using oxalic acid for standardising permanganate solutions,low results may be obtained owing to adsorption of water by thehydrated acid.This may be avoided by using sublimed anhydrousacid or hydrated acid that has been dried in a current of air previouslypassed over a mixture of anhydrous and hydrated acid.37 TOprevent t'he formation of hydrogen peroxide in the titration ofoxalic acid with permanganate, it is necessary to work a t a temper-ature of 75" to 85", and to have a suitable amount of sulphuric orhydrochloric acid present .3* Pure ferrous ammonium sulphate,however, has been shown to be a more suitable standardising agentthan oxalic acid, and it can be used at the ordinary temperat~re.~Metallic silver is also suitable for the standarciisation under specifiedconditions.&A method of determining cuprous oxide in presence of metalliccopper and cupric oxide has been based upon its solubility in3-6 N-sulphuric acid, and upon its then reacting with permangan-Permanganate has also been used for the determination ofbismuth after reduction with hydrazine hydrate and solution inan acidified solution of ferric chloride, the ferrous chloride formedbeing titrated.42 An analogous method has been devised fordetermining antimony, the metal being dissolved in warm hydro-chloric acid containing a cupric salt, and the amount of cuproussalt titrated with permanganate.In both methods, the solutionmust be effected in an atmosphere of carbon dioxide.43A method of determining: small amounts of molybdenum consistsin the reduction of ammonium molybdate or phosphomolybdate34 B. N. Angelescu, Bul. SOC. Chim. RomCinin, 1923, 5, 72; A., ii, 203.s5 L. Moser and M. Behr, 2. anorg. Chem., 1924, 134, 49; A., ii, 503.37 W. D. TreadwellandH. Johner, Helv. Chim. Actn, 1924,7,525; A., ii, 573.38 I. M.Kolthoff, 2. anal. Chem., 1924, 64, 185; A,, ii, 573.R. Doht, 2. anal. Chem., 1924, 64, 37; -4., ii, 569.I. M. Kolthoff and J. C. van Dijk, Phurm. Weekbblod, 1904, 61, 561;A . , ii, 506.*O N. A. Tananaev, 2. anorq. Chem., 1924, 136, 193; A., ii, 628." D. Niehida and K. Hirabayashi, J . Chem. I d . Japan, 1923, 26, 1123;J. Hand andA. Jilek, Chern. Lbty, 1924, 18, 8; A., ii, 278.4s A. Ecke, Chm. Ztg., 1924, 48, 537; A,, ii, 706.A., ii, 125166 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.by means of hydrogen in a silica tube a t 700°, solution of themolybdenum in phosphomolybdic acid, and titration of the solutionwith permanganate.44Potassium permanganate has been shown to be a convenientreagent for standardising thiosulphate solutions for use in iodo-metric determination^.^^ Among these iodometric methods is onefor determining thiosulphate in presence of sulphite, which dependsupon the fact that the compound of formaldehyde with sodiumhydrogen sulphite is not oxidised by iodine.46 Another applica-tion of iodometry is to the determination of hyposulphite.47 Mag-nesium may be determined by precipitation as magnesium ammoniumarsenate by means of a standard arsenate solution containingammonia and ammonium chloride, and iodometric titration of theexcess of arsenate in the filtrate.48It has been shown that sodium hypochlorite, which remains stablefor a long period, can be used as a substitute €or iodine in severaldeterminations, e.g., of tin, antimony, and arsenic 49; also thatbromine can replace iodine, notably in the titration of arseniousacid and of thios~lphate,5~ and of ammonia, sulphurous acid,hydrogen sulphide, and c h r ~ m a t e s .~ ~ Nascent bromine producedin a solution of a mixture of bromide and bromate is an excellentoxidising agent for sulphite and thiosulphate, the excess of brominebeing afterwards determined iodometrically. 52Antimony chloride may be used as a reducing agent in thevolumetric determination of hypochlorites and of ferricyanides, theexcess of the reagent being titrated with potassium bromate.53Among the new colorimetric methods is one in which bismuth isprecipitated as quinine iodobismutliate, the precipitate dissolvedin acetone, and the colour compared with a ~tandar61,5~ and anotherin which platinum is determined colorimetrically in the form of itsred i0doplatinate.5~ I n another method phosphoric acid is deter-mined by precipitstion with a nitric acid solution of ammonium44 A.Vila, Compt. rend., 1923, 177, 1219; A., ii, 65.45 J. M. Hendel, 2. anal. Chem., 1923, 63, 321; A., ii, 272.4 6 A. Kurtenacker, ibid., 1924, 64, 56; A., ii, 564.4 7 Brotherton & Co., Ltcl., Chemistry and Industry, 1923, 42, 1134 8 31. Klingenfms, 2. anorg. Chent., 1924, 138, 195; A., ii, 702.49 K. Jellinek and W. Krestev, 2. anorg. Chem., 1924, 137, 333 ; A.,60 W. Manchot and F. Oberhauser, 1933, 130, 161; A., ii, 199.61 Idem, Ber., 1924, 57, [ B ] , 29; A., ii, 274.ii, 56.i, 781.5a C. Mayr and J. Peyf&s,- 2. anorg. Chem., 1923, 127, 123; A., ii, 66.63 F.Feigl and 0. Schummer, Z. anal. Chem., 1924, 64, 249; A., ii, 624.54 C. E. Laporte, J. Pharm. Chim., 1023, [viil, 28, 304; A., ii, 68.66 E. G. Ardagh, F. S. Seaborne, and N. S. Grant, Can. Chem. Med., 1924,8, 117, 140; A., ii, 788ANALYTICAL CHEMISTRY. 167molybdate and strychnine nitrate, the precipitate dissolved insodium carbonate soh tion and heated with phenylhydrazinehydrochloride, and the red coloration compared with a ~tandard.~6Traces of nitric nitrogen may be determined colorimetrically bymeans of reduced strychnine and sulphuric acid,57 but nitrites mustbe removed or a correction applied for the coloration produced bythem before the addition of sulphuric acid.58Many new gravimetric methods for individual metals have beendevised.Cadmium may be separated from mercury by preci-pitation with ammonium thiocyanate and pyridine,59 and pre-cipitation as copper pyridine thiocyanate has been adapted to themicro-determination of copper.60 Traces of copper may also bedetermined as copper benzoinoxirne.61For the separation of mercury from arsenic, the precipitatedsulphides are treated with cold ammonia, and the undissolvedmercuric sulphide is freed from sulphur and dried.62 Pyrogallolhas been used as a reagent €or the gravimetric determination ofantimony,63 and the use of cupferron has been extended to thedetermination of uranium .64In the absence of potassium, rubidium, barium, ammonium salts,and sulphates, perchloric acid may be used for the quantitativeprecipitation of c~esium.65 Permutite has been found a suitablereagent for the quantitative separation of ammonia in urine ; thefinal determination is made by the use of Nessler's reagent.66Of the new distillation methods of inorganic analysis, an interest-ing one is based upon the fact that selenium chloride is volatile ina current of gaseous hydrogen chloride, arid may thus be separatedfrom tellurium chloride.67Elect rochem istry.An electrolytic method of removing soluble impurities fromcompletely insoluble precipitates has been based upon the fact that56 Y.Terada, Biochem. Z., 1924, 145, 426; A., ii, 499.5 7 F. M. Scales and A. P. Harrison, Ind. Eng. Chem., 1924, 16, 571; A . ,58 I. ill. Kolthoff, Chem. Weekblad, 1924, 21, 423; A., ii, 770.5* G.Rotter, 2. anal. Chem., 1924, 61, 102; *4., ii, 569.e0 G. Spacu, Bull. SOC. Stiinte Cluj, 1922, i, 206; A., 1923, ii, 41.61 R. Strebinger, Mikrochernie, 1923, 1, 72; A., ii, 204; compare Ann.62 P. Wenzer and M. Schilt, Helv. Chim. Acfa, 1924, 7, 907; A., ii, 873.1x3 F. Feigl, 2. anal. Chem., 1924, 64, 41; A., ii, 571.64 J. A. Holliday and T. R. Cunningham, Trans. Amer. Electrdem. SOC.,O5 E. Murmann, Oesterr. Chem. Ztg., 1923, 26, 164; A., ii, 60.6 6 A. Kolb, Chem. Ztg., 1924, 48, 557; A., ii, 699.6 7 V. Lenher and D. P. Smith, Ind. Eng. Chem., 1924, 16, 837; A., ii, 698.ii, 567.Report, 1923, 20, 171.1923, 43, 329; A., ii, 125168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.adsorbed substances, when subjected to the action of an electriccurrent, are completely dissolved and pass towards the electrode ofthe opposite sign to that they bear.By this means aluminiumhydroxide can be freed from entangled impurities, and ferric oxidefrom chromic acid.68Advantages have been claimed for the use of various kinds ofelectrodes, such as a rigid mercury cathode as a substitute for oneof platinum gauze for the deposition of various metals, includingzinc, bismuth, lead, cobalt, iron, and nickel, under specified con-ditions sQ; also for the use of glass electrodes for the determinationof hydrogen-ion c~ncentration.~O The quinhydrone electrode hasbeen shown to give $rustworthy results in determining the hydrogen-ion concentration of solutions more acid than pn8, in the presence ofa buffer, provided that substances with strong reducing or oxidisingaction are not pre~ent.7~ Mention may also be made of somesimple forms of hydrogen electrode, one of which has been adaptedto micro-determinations.72The special applications of electrolytic processes include a rapidmethod of separating silver, copper, and bismuth by the use ofgraduated potentials,73 and a rnicro-method for separating goldfrom potassium cyanide solution. 74An electrometric method of titrating silver ions in the presence ofcolloidal silver 75 has been devised. To obtain accurate results inthe electrometric titration of mercury with ammonium thiocyanate,it is essential that mercury ions should not be present ; the uncertainend-point in titrating mercuric nitrate is due to hydrolysis, and toprevent this a large excess of acid should be added.76It has been found that, of the different ferrocyanides, only thepotassium salt gives good results in the electrometric titration o€zinc.In the presence of cmium, a double ferrocyanide of zinc andczesium is formed, and the end-point is not sharp, but rubidium,contrary to what has been stated,77 has no effect on the compositionof the precipitate.78A. Charrion, Compt. rend., 1924, 178, 934; A., ii, 345.69 H. Paweck and E. Walther, 2. anal. Chem., 1924, 64, 89; A., ii, 562.70 A. L. von Steiger, 8. Elektrochem., 1924, 30, 259; A., ii, 696; W. E.7l V. K. LaMer and T. R. Parsons, J. Biol. Chem., 1923, 57, 613; A., ii, 55.72 F. J. Considine, AnaZyst, 1924, 49, 332; A., ii, 562.73 A.Lassieur, Compt. rend., 1924, 178, 847; A., ii, 568.74 K. Fuch, Mikrochemie, 1923, 1, 86; A., ii, 207.75 K. von Neergaard, Arch. Expt. Path. Phrm., 1923,100, 162; A., ii, 124.76 R. Muller and 0. Benda, 8. anorg. Chem., 1924, 134, 102; A., ii, 502.7 7 W. D. Treadwell and D. Chervet, He2v. Chim. Acta, 1922,5,633 ; A., 1922,78 I. M. Kolthoff and E. J. A. H. Verzijl,qRec, trw. chim., 1924, 4?, 389;Brown, J. Sci. Instruments, 1924, 2, 12; A., ii, 869.ii, 786.A., ii, 501ANALYTICAL CHEMISTRY. 169An electrometric method of determining barium, even in thepresence of calcium, has been based upon the fact that, on shakingfreshly precipitated lead sulphate for 24 hours with barium chloridesolution, about 98% of the barium is converted into bariumsulphate, the amount of which is determined by titrating the leadin solution electrometrically with potassium ferro~yanide.7~ Ananalogous method of determining soluble sulphates consists inadding alcohol to the solution, then a measured excess of standardlead nitrate solution, and titrating the excess of lead in the filtratefrom the precipitated lead sulphate.8OA method of titrating chlorides with a mercurous solution hasbeen devised, in which the end-point is determined electrometricallywith an amalgamated platinum electrode; it has also been shownthat nitrates may be determined by means of their oxidising actionon ferrous sulphate and electrometric titration of the ferric saltwith titanous chloride solution.81Fairly accurate results can be obtained in the titration of chromicacid with alkali, either with the use of a hydrogen electrode, orwith the usual oxygen electrode, the electrometric end-point occur-ring somewhat later than the end-point as indicated by phenol-ph thalein. s2An electrometric method of determining carbon dioxide (accurateto 0.002%) has been devised for the study of photosynthesis, theair being passed through a solution of barium hydroxide, the con-ductivity of which is then determined .83For the electrometric determination of formaldehyde, advantagehas been taken of the fact that silver nitrate is quantitatively reducedto meta,llic silver by formaldehyde in presence of an excess of sodiumcarbonate. After the reduction, the excess of silver (present ascarbonate) is determined electrometrically by titration with potass-ium chloride (after neutralisation), or with potassium iodide (withoutneutralisation) .84Water Analysis.A method of determining dissolved air in small quantities of waterhas been based upon the fact that when potassium hydroxide orcertain salts, such as ammonium chloride or sulphate, are dissolvedin the water, the air is expelled and can be collected and measuredE.Miiller and R. Wertheim, 2. anorg. Chem., 1924,135, 269; A., ii. 568.so Idem. ibid.. 1924 133. 412; A , . ii. 564.81 E. Miiller, 2. Elektrochem., 1924, 30, 420; A., ii, 777.82 H. T. S. Britton, J., 1924, 125, 1572.83 H. A. Spoehr and J. M. McGee, Ind. Eng. Chem., 1924, 16, 128; A.,84 E.Miiller and W. Low, 2. anal. Chem., 1924, 64, 297; A., ii, 706.ii, 275.a170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in a small graduated apparatus filled with mercury. Subsequently,the oxygen is absorbed by means of alkaline pyrogallol and thenitrogen measured.85It has been shown that precipitation of the total carbon dioxidein hard waters by means of calcium hydroxide or barium hydroxideand titration of the excess of precipitant give low results, but thatby adding a sma,ll amount of calcium carbonate to a solution ofcalcium hydroxide and calcium chloride a reagent that gives quanti-tative results in this method is obtained.86I n determining minute quantities of lead and copper together inwater by Winkler’s colorimetric method, the results for copper(obtained from the difference between the colorimetric reading forthe two metals together and that for lead alone, after solution ofthe colloidal copper by the addition of cyanide) require correction,since the colour of lead sulphide is less intense than that o€ coppersulphide.87 The presence of copper also interferes with the sensi-tiveness of Thresh’s colorimetric method of determining 1 ead bymeans of a gelatin and acid solution and of hydrogen sulphide.88A better method of preparing the reagent has been devised, and theprocess has been shm-n to give accurate results for determiningtraces of lead both in water and in urine.89A new method of determining small quantities of calcium andmagnesium depends upon their forming micro-crystalline precipitatesof the respective ferrocyanides. The reagent consists of a solutionof ammonium ferrocyanide containing 50% of alcohol, and it maybe used for determining the amounts of calcium and magnesiumsepamfely, or the hardness of a water, by measuring with a nephelo-meter the white turbidity that i t produces.90A colorimetric method of determining soluble aluminium in waterwith an accuracy of 0.01% has been based upon the well-knowncolour reaction of aluminium with hzmatoxylin. The pH value isfirst brought t o 8.2-8-3 by the addition of ammonium carbonate,and acetic acid is added before comparison with the standardsolution, to eliminate the influence of iron and magnesium ~ a l t s . ~ 1C. AINSWORTH MITCIIELL.s5 H. S. Becker and W. E. Abbott, J . SOC. Chem. Ind., 1923, 42, 484.11;8 6 E. M. Crowther and W. S. Martin, J., 1924, 125, 1937.87 C. Pyriki, 2. anal. Chem., 1924, 64, 325; A,, ii, 702.8 8 J. C. Thresh, Analyst, 1921, 443, 270; A., 1921, ii, 551.90 F. Feigl and F. Pavelea, Mikrochernie, 1924, 2, 85 ; A., ii, 784.91 W. D. Hatfield, Ind. Eng. Chem., 1924, 16, 233; A., ii, 350.A., ii, 200.Idem, ibid., 1924, 49, 124; A., ii, 124

ISSN:0365-6217    

DOI:10.1039/AR9242100151

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

BIOCHEMISTRY.FOR some time past it has been evident that, with the rapid advancein the knowledge of the chemical processes of the living cell, it wasbecoming increasingly difficult to discuss many of them adequatelyin separate sections devoted to plant and animal chemistry. Theconviction that to continue to do so would inevitably tend tonarrow the outlook has led, this year, to a fusion of the AnnualReport on Physiological Chemistry with that on AgriculturalChemistry and Vegetable Physiology. By this means it is hoped topresent, in one annual Report on Biochemistry, that broader con-ception of many fundamental biological changes, as, for example,the degradation of dextrose, whether effected by muscle cells, byyeast, or by the cells of the higher plants, which is essential to theprogress of this great branch of Chemistry.It must be pointed out that this fusion of the two Reports involvesthe inclusion, under the general title of Biochemistry, of thechemistry of the soil, a branch of agricultural chemistry that hasalways figured in the past as part of the Report on AgriculturalChemistry and Vegetable Physiology.This of course is as it shouldbe, since the logical sequence is to consider first the medium inwhich the plant grows, then the plant itself, and then finally theanimal that feeds on the plant.In the case of the present Report, the opening section, that onSoils, is devoted mainly to a discussion of the inorganic andphysical chemistry of the soil. No apology is made for this, sincethe proper understanding of the factors controlling the biologicalprocesses in the soil and the uptake of essential elements by theplant necessitates a consideration of the soil in all its aspects;attention is directed to the fact merely to explain the apparentanomaly of a report on biochemistry the first part of which isseemingly wholly unconnected with the chemistry of biologicalprocesses.It must also be mentioned that consideration of the chemistryof enzyme action and fermentation has been again deferred toanother year, as it was not felt that these subjects have advancedsufficiently since they were last reviewed to justify giving up tothem space that could be better employed on other branches ofbiochemistry more in need of discussion.In the last two Reports, published work on all the main aspects171 a" 172 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of soil and plant chemistry was used in an attempt to give anaccount of the relations of these different aspects to one another,and so to sketch in the main lines of the subject as a whole.I nthis Report, certain aspects of the subject have been selected forfuller and more detailed discussion, and others have been entirelyomitted, these being left over for similar special treatment insubsequent Reports.S o i l s .The Nature and Properties of #oil Constituents.The two chief constituents of a soil that characterise it andserve to distinguish it from a mass of unweathered rock fragmentsare ( a ) the dark-coloured humic matter, and ( b ) the complex inorganicmaterial which forms the chief constituent of clay.The Humic Matter of the Soil.-In recent Reports attention hasbeen directed to the uncertainty that exists as to the origin andmode of formation of the humic matter in the soil.1 One group ofworkers regards this material as a product of decomposition ofcellulose or other carbohydrates , whilst other invest ig a t ors holdthe view that it is derived from aromatic substances of a phenolicnature, among which lignin is included.Various considerationsrender the latter alternative the more attractive one, and duringthe past year further evidence has been advanced which con-siderably strengthens this view.F. Fischer,2 who advanced the hypothesis that lignin is the parentsubstance of humic acid in 1921, has cited the work of Bray andAndrews in support of that view.These authors showed thatduring the bacterial decay of wood the cellulose had almost dis-appeared in the space of three years, whereas the lignin hadsuffered little diminution in amount. Schwalbe’s experiments, inwhich he prepared a substance resembling coal by the action ofpowerful dehydrating agents on cellulose, are held not to be validin determining the origin of coal, because the conditions were sodifferent from those prevailing in nature. It is far more probablethat dead vegetation would be rapidly subject to bacterial decay,with consequent destlruction of cellulose, and that humic matter(and subsequently coal) would be produced by chemical autoxida-tion of the lignin, which is much more resistant to bacterial action.H.Tropsch and A. Schellenberg carried out in 1921 a series ofinvestigations on the products of dry distillation of humic acidAnn. Reports, 1922, 19, 204; 1923, 20, 209.Brennstoff-Chem., 1924, 5, 132; A., i, 715.J . Ind. Eng. Chem., 1924, 16, 137.C. G. Schwalbe and R. Schepp, Ber., 1924, 57, [B], 319, 881; A., i, 377,71BIOCHEMISTRY. 173(prepared from coal) and of its interaction with various reagentssuch as potassium hydroxide, nitric acid, sulphuric acid, chlorine.The results of this work have only recently become generallyavailable .5 They show that relatively simple aromatic substancesare readily formed from humic acid, and that humic acid and ligninbehave similarly.Cellulose and dextrose, and artificial humic acidprepared from sugar, however, behave somewhat differently . F.Fischer and H. Tropsch 6 have extended this work by a comparisonof the behaviour of cellulose and of lignin on hydrogenation withhydriodic acid under pressure, and on treatment with causticalkalis. The results of this work also support the view that ligninrather than cellulose is the parent substance of humic acid, whilstthe work of A. R. Pearson on the oxidation of humic matter fromcoal with bromine and alkali also points in the same direction. Aspointed out by .H. Tropsch,8 the occasional occurrence of smallquantities of cellulosic material in coal is no proof that coal (andhumic acid) is produced from cellulose.On the theory that celluloseis converted into coal by the action of heat and pressure it is farmore difficult to account for the survival of cellulose here and therethan it is on the supposition that cellulose disappears by the actionof micro-organisms, in which case the local occurrence of asepticconditions would readily explain this survival.Recent work in the reporter’s laboratory a t Rothamsted hasprovided evidence for the lignin hypothesis of the origin of humicmatter, from quite a different direction. From a study of thefractionation of organic matter in mineral soils, C. W. B. Arnoldobtained results indicating that the humic matter in Rothamstedsoils manured and cropped in various ways was of the samecharacter in all cases ; this fact can most readily be explained on thehypothesis that humic matter is formed in the soil from onecommon constituent of all plant residues, and that its amountdepends on the amount of this common constituent in the organicmatter supplied to the soil, all the other organic constituents sosupplied being completely destroyed by biological ageiicies. Thenatural inference to draw, in view of the facts discussed above, isthat this humus-forming constituent is lignin.Following up thisidea, M. S. du Toit lo has studied the relation between the amountof humic matter formed when various plant materials are allowedto rot down in the presence of soil organisms and the amounts ofGes. Abh. Kenntn. Kohle, 1921, 6, 191, 196, 214, 235, 248, 257; A.,i, 619-621.Ber., 1923, 56, [B], 2418; A., i, 148.Fuel, 1924, 3, 297; A., i, 620,B~ennstofl-Chern., 1924, 5, 288. Not yet published.lo M. S. du Toit, ”The Origin and Mods of Formation of the HumicMatter of the Soil.’’ Ph.D. Thesis, Cambridge, 1924174 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the chief constituents (cellulose, pentosans, lignin) that have beendestroyed. There was no correlation between humic matter pro-duced and either cellulose or pentosans destroyed, but in all casesthe disappearance of lignin was paralleled by the production ofhumic matter. Moreover, when pure carbohydrates (cellulose,pentosans, sugars) were decomposed by soil organisms, their com-plete disappearance was not attended with the production of anyhumic matter whatever.There is thus on the whole quite a large ljody of evidence infavour of the hypothesis that the humic matter of the soil is derivedfrom lignin and not from carbohydrates.A definite proof of thevalidity of this hypothesis must provide evidence of the identityof the natural product with the humic acid produced artificiallyfrom lignin, and before such identity can be established, improve-ments in the methods of purifying the natural product are needed.That the so-called humic acid of the soil is indeed a true acid wasclearly shown by Od6n l1 for the product obtained from peat.The application of similar methods (conductometric titration) topurified humic acid from Rothamsted soil and to the artificialproduct obtained by the oxidation of lignin showed that both ofthese substances behave in the same way as Odbn’s peat humicacid,1° and therefore must be regarded as true acids of high mole-cular weight, practically insoluble in the free state, but readilygiving colloidal solutions.Their salts with alkali metals are solubleand behave as colloidal electrolytes, whilst their salts with othermetals are insoluble.The Inorganic Colloidctl Material of the Xoil .-Many interestingproblems arise from the consideration of the chemical processesthat occur in the formation of soil and the weathering of minerals,and increasing attention is being directed to this subject on theContinent, following the lead of Glinka and the Russian School,and in the United States. A detailed discussion of this part of thesubject must be deferred to another year, but reference may herebe made to a useful summary which has been published by G.W.Robinson .I2In temperate regions, the product of this weathering is a colloidalmaterial, the characteristic constituent of clay, containing silica,aluminium and ferric oxides together with a certain amount ofbases. The older the soil is, the greater is the loss of these bases byleaching, and under certain conditions they may be entirely removed.According to the degree of depletion of bases, the residual colloidexhibits a greater or less degree of acidity. The cause of theacidity has been the subject of much controversy, but during the11 Trans. Paraday SOC., 1922, 7, 288. la Geol. Mag., 1924, 61, 444BIOCHEMISTRY.175past two or three years a number of important investigations havebeen carried out as a result of which the position of the whole subjecthas been considerably clarified.Reference was made in last year’s Report l3 to the work of Brad-field, in which, from an examination of the colloidal materialseparated from a subsoil clay by the use of the “ super-centrifuge,”he showed that this colloidal material could not be regarded as beingmade up of a mixture of the hydrates of silica, alumina, and ferricoxide, but that it consisted of a dehite compound or mixture ofcompounds in which the three constituent oxides were chemicallycombined in the form of complex aluminosilicates. W. 0. Robin-son and R. S. Holmes l4 have since published the results of aninvestigation into the chemical composition of the soil colloids fromforty-five soils from the United States.The colloidal matter wasseparated by the “ super-centrifuge ” and analysed. It was foundthat only a small part of this material consisted of finely divided,unweathered mineral fragments, and that most of it consisted ofmaterial that behaved as an intimate mixture of complex alumino-silicates, not as a mixture of the separate constituent oxides, thusconfirming the results of Bradfield. There were apparently twoforms of iron present, one a hydrous ferric oxide, presumably inthe free state, and the other some compound without red or yellowcolour, presumably a silicate.During the past year Bradfield has published two important paperswhich must be considered in some detail.In one of his earlierpapers l5 he showed that sharp end-points could be obtained inconductivity titrations of clays or soils if these were carried out insuch a manner as to make possible the detection of the end-pointin the neutralisation of a weak acid by a strong base, that is, by thegradual addition of the clay suspension to a fixed quantity of thestrong base, instead of in the reverse manner as had been done inmost previous investigations. The titration curves then bore noresemblance to an “ adsorption isotherm,” but indicated thatdefinite weak acids were being neutralised. This was supportedby the further result that practically equivalent amounts ofdifferent bases were needed for the attainment of neutralisation asindicated by the breaks in the titration curves.He advancedcogent arguments to show that the results used by Salter andMorgan l6 in favour of the view that the reaction between clay andalkalis is a physical adsorption are really less compatible with thatAnn. Reprttj, 1923, 20, 201.14 U.S. Dept. of ,4gric., Dept. Bulletin No. 1311, 1924, pp. 1-41.lF, Ann. Reports, 1923, 20, 204.18 J . Phy8ioraE Chem., 1923, 27, 117; A., 1923, i, 523176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRT.view than with what would be expected from the chemical inter-action of bases with a colloidal, high-molecular, weak acid. Brad-field has now produced further evidence in favour of the latterview.17 He prepared a series of suspensions of the same colloidalclay material, containing varying proportions of water, anddetermined the hydrogen-ion concentration of these by the hydrogenelectrode method.The curve obtained by plotting hydrogen-ionconcentration against dilution was compared with that showingthe hydrogen-ion concentration of solutions of acetic acid a t varyingdilutions. The two curves were very similar in form, from whichit appears that the colloidal matter behaves as a true acid, althoughprobably much weaker than acetic acid. I n another paper 18Bradfield has described the result of further experiments in whichhe has studied the influence of the hydrogen-ion concentration onthe flocculation of clay suspensions by electrolytes and on absorptionand base exchange.Although the total amounts of acids ofdifferent strengths needed to flocculate colloidal clay suspensionsmay vary widely if expressed in terms of the titratable acidity,flocculation occurred at about the same hydrogen-ion concentrationin all these cases. Further, when a suspension of an acid colloidalclay was flocculated with solutions of pH varying between 3 and 11,but all containing the same concentration of potassium, the elec-trolyte requirement increased gradually as the hydrogen-ion con-centration decreased, until the neutral point was approached ;then the amount of electrolyte required increased rapidly until apH of 8.5 was reached, and remained constant from there to pH 12.This sudden increase a t the neutral point in the case of an acid clayis taken to indicate that the alkaline mixtures have an additionalfunction compared with the other mixtures : they must neutralisethe clay acids, then flocculate the resulting potassium salt.Thisconclusion is supported by the fact that a neutral clay showed nomarked change in electrolyte requirement a t the neutral point.Moreover, when varying concentrations of acid clay are used, theamount of potassium required for flocculation in the alkalineregion increases in proportion to the increase in concentration ofthe clay. Besides the significance of these results in their bearingon the nature of the acidity of acid soils and on the chemical natureof the colloidal clay substance, they are also of importance asindicating that in studies on the flocculation of clay suspensionscomparable results cannot be obtained unless due attention is paidto the hydrogen-ion concentration, and the concentration of thesuspension, as well as to the reaction of the clay under investigation.The absorption of kations from neutral salts by clays, and the17 J.Physical Chem.,1924, 28, 170. l6 Soil Sci., 1924, 17, 411; A,, i, 927BIOCHEMISTRY. 177exchange of bases, are also influenced by the hydrogen-ion concen-tration. Determinations of the amounts of total bases in thesolution obtained when a series of solutions of varying pH but ofconstant potassium content were added to a suspension of an acidcolloidal clay showed that the sign and magnitude of the “basebalance ” depended on the pH of the solution : when the hydrogen-ion concentration of the solution was greater than that of the claysuspension, the amount of potassium absorbed (i.e., removed fromthe solution) was less than the amount of other bases liberated(expressed in equivalents)-there was a positive “ base balance,”which was greater the greater the excess of the hydrogen-ion con-centration of the solution above that of the clay suspension.Whenhowever, the solution had a lower hydrogen-ion concentration thanthe clay suspension, the number of equivalents of potassiumabsorbed was greater than that of the other bases liberated-thebase balance was negative, the magnitude of this increasing steadilyup to a pR of about 11 and then changing more slowly. Only whenthe reaction of the solution was the same as that of the clay suspen-sion was there a chemically equivalent base exchange in which theamount of other bases appearing in the solution was equivalent tothe amount of potash absorbed.If the clay material be regarded as a true acid, the interpretationof these results is comparatively simple.An acid colloidal claywhich still contains replaceable bases must be regarded as a complexacid salt. If this acid salt is treated with a more acid solution, thenet result will be the liberation of some of the bases from the acidsalt with the production of a still more acid salt ; if, on the otherhand, the solution added to the acid salt is itself less acid (i.e.,more alkaline), the net result will be the neutralisation of a part ofthe residual acidity of the acid salt-the production of a clay inwhich a greater proportion of the acidic hydrogens have beenreplaced by basic kations.These results serve not only to clear up many anomalies andcontradictions in past work on “ adsorption ” and base exchange,in which no attention was paid to the hydrogen-ion concentrationof the medium, but they also provide a satisfactory basis for theinterpretation of the phenomena of soil acidity, “ adsorption ” andbase exchange on purely chemical lines.The demonstration of the acidic character of the clay substance,and of its behaviour in a manner consistent with that acid characterover a wide range of p,, raises the question of whether there is anyreal foundation for the view put forward a few years ago by S.Arrhenius,lg according to which, clay may act as an ampholyteIs J.Amer. Chem. SOC., 1922, 44, 521; A., i, 707178 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and display a behaviour analogous to that of proteins, in accordancewith the explanation of Loeb. Bradfield 2o has shown in an earlierpaper that the flocculation experiments on which Arrhenius basedhis view are susceptible of another interpretation, in which theDonnan effect may be concerned.21 His cataphoresis experimentsafforded no support for Arrhenius’s view, nor does the behaviourof clay throughout the range of hydrogen-ion concentration used inthe experiments described above give any indication of the posses-sion of amphoteric properties by the clay.W. C. Dayhuff andD. R. Hoagland 22 have now made a careful series of cataphoresismeasurements with an acid clay over a range of hydrogen-ion con-centrations between p E 2.1 to 12.7. Their results indicated thatthroughout the whole of this range the clay particles carried anegative charge : they always moved towards the kathode. Theabove range of p , more than covers that in which all soils fall, sothat it may be taken as established that under natural conditionsclay does not behave as an ampholyte. It is, of course, possiblethat outside the above range of pH clay might exhibit amphotericproperties, but it must be borne in mind that under the stronglyalkaline or acid conditions obtaining outside that range secondarychemical reactions are likely to be involved in which decompositionof the complex aluminosilicic acids of the clay would occur, withthe production of silica, which carries a negative charge, and ofalumina and ferric oxide, which carry positive charges.Many workers have advanced interpretations of the behaviourof clay suspensions to flocculating agents, in which absorption ofhydroxyl ions was assumed in order to explain the stabilising in-fluence of alkali in certain concentrations. Dayhuff and Hoagland,in discussing their results, point out how such an assumption isunnecessary, and they indicate how, according to the results ofBradfield, Mattson,23 and other workers, the predominant factorsdetermining the stability of clay suspensions may be the nature andconcentration of the kation present in the medium.The Chemical Interpretation of the Phenmnena of ‘‘ Adsorption ” andIn last year’s Report 24 special attention was directed to thequestion of alkali soils, and after reference to the pioneering workof Gedroiz in this field, and to the important investigations of30 Missouri Agri.Expt. Sta. Res. Bull. 60, 1923.91 The application of the Donnan effect to soils is also discussed by23 Soil Sci., 1924, 18, 401.2s S. E. Mattson, Koll. Chern. Beihefte, 1922, 14, 227; A., 1922, i, 800.Acidity in Xoils.N. M. Comber, Tram. Faradcly SOC., 1924.A m . Reports, 1923, 20, 206BIOCHEMISTRY. 179Hissink, the work of Cummins and Kelley on the formation of“ black alkali ” soils was discussed in some detail.This aspect ofbase exchange in soils may therefore be passed over in this Report,and the remainder of this part of the Soils section will be devoted toa brief discussion of the existing state of our knowledge of the factsof base exchange in soils with special reference to their bearing, inthe light of the above discussion, on the mechanism of absorptionby soils and on soil acidity.When a neutral soil is treated with a solution oE a neutral salt,an exchange of kations takes place, the cardinal features of whichare: (i) The amount of the kations of the neutral salt that areremoved from the solution is stoicheiometrically equivalent to theamount of the other kations that are given up to the liquid by thesoil. The anion of the neutral salt is not changed in concentration.Salts of acids, such as phosphoric, that give insoluble precipitateswith calcium, aluminium, and other soil constituents, are of courseexcluded from these considerations .25(ii) This exchange of kations occurs practically instantaneously.(iii) The extent to which this exchange takes place varies ex-ponentially with the equilibrium concentration of the enteringkation ( L e ., that of the neutral salt used), thus conforming to thegeneral type of Freundlich’s adsorption curves and equations.By continually leaching a soil with fresh portions of %I neutralsalt solution, the equilibrium is continually disturbed, and the soilcan thus be brought into such a condition that the whole of itsabsorbed kations are of one kind.The physical and other propertiesof the resulting soil vary markedly with the nature of the absorbedkation, as is well illustrated in connexion with alkali soils.The absorbing material of soils that are acid (that is, soils theaqueous suspensions of which have pX values of less than 7.07),contains a smaller amount of exchangeable bases than that ofneutral soils; these acid soils are “ unsaturated,” and in generalthe greater their degree of unsaturation the more acid they are.Base exchange in neutral soils does not present any specialfeatures that need cause controversy between the upholders of thephysical theory of absorption and those who prefer to regard thephenomena as essentially chemical. When, however, acid-‘‘ unsaturated ”--soils are considered, especially with reference tothe behaviour of such soils on treatment with neutral salts and withalkalis, we are on much more contentious ground.Such soils, ontreatment with a neutral salt, give an acid reaction to the liquid, theacidity so developed being known as “latent ” or “exchange ”acidity. This acidity is due to a hydrogen-ion concentration that isa5 N. M. Comber, Zoc. cit180 ANNUAL REPORTS ON THE PROGRESS 06 CHEMISTRY.higher than that of the “actual ” or L c active” acidity of the soil, whichis the acidity shown by the soil suspension in water. Finally, thereis another form of acidity, the ‘‘ total ” acidity, which representsthe amount of base that must be added to bring the soil to neutrality.The upholders of the hypothesis of physical “ adsorption ” in soilsexplain the “ exchange ” acidity as due to the selective adsorptioncf the kation of the neutral salt, leaving the anion in the solution,while the ‘‘ total ” acidity is due to the fact that the soil can absorbbasic hydroxide as a whole.Only recently has it been pointed out, by Gedroiz 26 in Russiaand by Hissink2’ in Holland, that all these phenomena can bebrought into line if we look upon the absorbing material of the soilas having a definite saturation capacity for kations, and further, ifwe assume that the absorbing material can absorb hydrogen ionsas well as metallic kations.The absorbing material of a soil is thenalways saturated with a constant amount of kations, the onlydifference being that in an acid soil a larger proportion of thesekations are hydrogen ions than is the case with a neutral soil.Suchan acid soil gives rise to a definite hydrogen-ion concentration inaqueous suspension, this being the equilibrium concentration forthe liquid phase in equilibrium with the absorbed ions of the solidphase. When the soil is treated with a salt solution, there is anexchange between the kations of the neutral salt and hydrogen ionsabsorbed by the solid phase, so that at equilibrium the latter con-tains a greater proportion of absorbed basic kations and the liquidphase contains a greater concentration of hydrogen ions. Theextent to which this exchange takes place depends on the strengthof the acid the salt of which is used.In the case of the salt of astrong acid such as hydrochloric acid, the amount of titratableacidity liberated is small, but in the case of the salt of a weak acidsuch as acetic acid, the titratible acidity developed is much larger,since, owing to the low dissociation of acetic acid, a much greaterdisplacement of hydrogen ions from the solid phase can occur beforethe equilibrium concentration of hydrogen ions in the liquid phaseis reached. Further, the addition of an alkaline hydroxide to anacid salt can similarly be pictured as an exchange of basic kationsfor hydrogen ions, only in this case the liberated hydrogen ionsEditorial Com-mittee of the People’s Commissariat of Agriculture, Leningrad, 1922 ; Zhur.Opit. Agron., 1924, 22, 3.A complete set of translations of Gedroiz’s paperson the subject of absorption and bass exchange is in the possession of thereporter (H. J. P.), through the cour6esy of the U.S. Dept. of Agriculture.Workers in this field who are desirous of studying these translations shouldcommunicate with H. J. P. at Rothnmsted.26 K. K. Gedroiz, “ On the Absorptive Power of Soils.”27 Tram. Paraclccy SOC., 1924BIOCHEMISTRY. 181combine with the hydroxyl ions in the solution to form water, andhence the absorption of the base goes on without the appearance ofother kations in the liquid.The soluble iron and aluminium that are found in acid soils, andthat appear to a marked extent in the acid solution obtained bytreating these soils with neutral salt solutions, can most readilybe regarded as being liberated by secondary reactions between theacid liberated and some constituents of the solid phase, although itis not impossible that they may exist, at least in part, as exchangeablekations absorbed by the solid phase, and liberated by exchange inthe same way as other kations.From the above discussion it will be seen that it is possible toexplain the phenomena of absorption by soils, soil acidity, and baseexchange as all due to the occurrence of ionic exchanges, whichoccur owing to the absorptive material of the soil having a definiteaffinity for kations, including hydrogen ions.By itself, however,this explanation does not carry matters very much further, foralthough it brings a number of apparently differing phenomenainto one category, it still leaves unanswered the question of thenature of the attraction whereby the absorbing material of the soilabsorbs kations. Here, however, the results of Bradfield that arediscussed on pp.175-1 78 are of importance. Hissink 27 explainsthe absorptive capacity of the soil as due to the existence of colloidalacids, which are ionised at the interface between the solid and theliquid phase, so that an electrical double layer is formed at thatinterface, with the negatively charged complex colloidal anion onthe solid phase side of the double layer and with positively chargedhydrogen or metallic ions on the liquid side. Now that Bradfieldhas clearly demonstrated that the colloidal clay material of soils doesactually behave as a true acid, this fact, together with the proofthat the humic acids of soils are also true acids, provides a soundexperimental basis for Hissink’s hypothesis, and it is possible toexplain all the phenomena in question as chemical ionic reactionsof weak acids (clay acids and humic acids), these reactions beinglocalised at a solid-liquid interface owing to the fact that theseacids are insoluble and present in the soil as colloidal particles oras a gel on the surface of mineral soil particles.The practicallyinstantaneous nature of the reaction is, of course, what would beexpected of ionic interchanges of this nature ; moreover, thelocalisation of the ionic exchanges at a surface necessarily places theequilibrium conditions in a different category from those obtainingfor reactions which take place wholly in the liquid phase. Theexponential character of the relation connecting the equilibriumconcentration of the entering ion in the liquid phase with the amoun182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of it which has been absorbed is what would be expected in a systemof this sort.As has been pointed out by E. A. Fisher 28 and others,the fact that a given set of data can be represented by an exponentialcurve, and made to fit a Freundlich “ adsorption ” equation, is noevidence that the reaction in question is EL physical adsorption.Many purely chemical reactions in a heterogeneous system conformto an equation of the same type.In the short space of this discussion it is not possible to followthe application of this hypothesis to the detailed phenomena ofthe soil, nor for that matter must it be regarded as more than atentative one a t present, as much experimental work still remainsto be done.It does, however, appear that this hypothesis rendersunnecessary the assumption of the existence of purely physical“ adsorptions ” in the soil. I n following the detailed applicationof these views it is necessary to take account of the relative intensitywith which different ions are held by the absorbing material, andthe influence of the degree of hydration of the ions. Gedroiz 29has recently made a very interesting and convincing study ofthe physical propert,ies of the soil from this point of view, butconsiderations of space do not allow of the discussion of this workhere.The views developed in the above discussion depend on or arerelevant to a number of recent papers in addition to those actuallycited.Detailed reference to these was omitted above in order toallow of a broad presentation of the main outline of the subject.Some of the more important of these other papers are noted below.30The In$uence of Xoil Acidity on Plant Growth.The effect of soil acidity on plant growth may depend on factorsother than the actual hydrog en-ion concentration of the soil, suchas, for instance, the presence of soluble aluminium compounds.31There is a tendency in several recent papers to direct attention tothe fact that on many acid soils the factor deleterious to crop growth2 * E.A. Fisher, Trans. Paraday SOC., 1922, 17, 305.29 K. K. Gedroiz, Zhur. Opit. Agron., 1924, 22, 29.80 W. P. Kelley and S. M. Brown, Univ. Calif. Pub. Agric. Sci. Techn.Paper No. 15, 1924, pp. 1-39. J. W. Tidmore and F. W. Parker, Soil Sci.,1924, 18, 331; A., i, 1394. H. J. Page and W. Williams, Trans. ParadaySOC., 1924. H. Kappen, Z. Pflanz. Dung., 1924, [ A ] , 3, 209; A. Densch,ibid., 218; E. Ramann, ibid., 257. W. Hummelschen and H. Kappen,ibid., 289.Ann. Reports, 1922, 19, 213; 1923, 20, 207. See also Whiting, J .Amer. Soc. Agron., 1923, 15, 277; A., i, 928. W. T. McGeorge, Soil Sci.,1924, 18, 1. G. N. Hofferanci J. F. Trost, J . Amer. SOC. Agron., 1923, 15, 323; A,, i, 925.0. Lemmermann and L. Fresenius, ibid., p.1 ; [B], 3, 233.S. D. Comer, J. Ind. Eng. Chem., 1924, 16, 173BIOCHEMISTRY. 183may not be acidity, but lack of sufficient calcium.32 This is wellillustrated by the papers by G . W. Robinson, C. 0. Swanson, P. L.Gainey and W. L. Latshaw, and Duley.Seldom, if ever, is a cultivat'ed soil so acid that it does not stillcontain a certain amount of replaceable kations, mainly consistingof calcium, but when this amount falls below a certain value, cropfailure owing to calcium starvation is liable to occur. If, on theother hand, the amount of replaceable, or readily soluble, calciumis above this value, the soil may still be quite acid, and yet manycrops will flourish on it. The " lime requirement " of a soil, whichis not a soil " constant " but necessarily varies according to thetype of crop and to other conditions, is thus usually, in practice,definitely less tha,n the amount of lime needed to bring the soil toneutrality (pn 7-07).It is important to remember that even a tneutrality the soil colloids are still far from saturated; they stillcontain replaceable hydrogen ions, as evidenced by the fact thatby the addition of a neutral salt to a faintly alkaline soil the reactionof the solution is usually brought slightly on to the acid side. Thiswould, of course, be expected in the case of a weak acid, whichwould exist wholly as a salt ( i . e . , free from replaceable hydrogenions) only a t a p H well on the alkaline side. Thus the actual per-centage saturation with calcium of a soil that is definitely acid maybe relatively only slightly less than that of the soil at neutrality,and it may often be necessary for the hydrogen-ion concentrationof the soil to become very marked before the degree of saturationof the absorbing material with calcium is so much lowered thatthere is insufficient readily available calcium to meet the needs ofthe plant.Biochemical Changes in 'the oil.This branch of the subject has been rather fully discussed in theReports for 1922 and 1923,33 so that in order to leave space in thisReport for the fuller treatment given to other branches of thesubject, consideration of the work published on the biochemicalprocess in the soil during the past year will be deferred to the nextReport.Although several interesting papers have appeared, theposition of the subject has not changed materially during the periodun der review.32 G.W. Robinson and R. Williams, Trans. Paraday SOC., 1924;F. L. Duley, Soil Sci., 1924, 17, 213. C. 0. Swanson, P. L. Gainey, andW. L. Latshaw, ibid., 181; A,, i, 820. A. G. McCall, J . Amer. SOC. Agron.,1923, 15, 290; A., i, 922. Denseh, Hunnius, and Pfaff, 2. Pflanz. Diing.,1924, [ B ] , 3, 248. A. Schuckenberg, &id., 65. D. Drushinin, Arb. Wiw.Inet. Duiagemittel (russ)., 1923, Lief. 20, 1. Chem. Zentr., 1924, i, 1999.33 Ann. Reports, 1922, 19, 207; 1923, 20, 210184 ANNUAL REPORTS ON TRE PROGRESS OF CHEMISTRY.T h e C h e m i s t r y of t h e L i v i n g P l a n t .Carbon Assimilation and Photosynthesis.Baeyer’s hypothesis that the first stage in the photosynthesis ofcarbohydrates from carbon dioxide and water is’ the production offormaldehyde, which is subsequently polymerised to sugars, stillfinds acceptance in most quarters. Owing to the experimentaldifficulties in this field, and to the fact that the process of carbonassimilation consists of a whole series of consecutive reactions whichproceed very rapidly, direct evidence of the validity of the hypo-thesis is lacking, and will probably continue so.In recent years,however, a considerable amount of indirect evidence has beenproduced which greatly strengthens the probability that Baeyer’shypothesis is the correct one ; the investigations of Willstatter andStol13* and of Baly and his co-workers 35 are perhaps the mostimportant in this connexion.The exact mode of production offormaldehyde, however, and the part played by various factors inthis process, remain subjects of much speculation and theorising.Particularly controversial is the question of the part played bychlorophyll in the process. According to the views of Baly, Heilbron,and Barker, the chlorophyll acts as a photocatalytic energy trans-former, absorbing radiant energy from the region of the visiblespectrum, and radiating energy of infra-red wave-length suitable forthe conversion of carbon dioxide (loosely combined with the chloro-phyll) into activated formaldehyde. Willstatter and Stoll’s hypo-thesis, which is not incompatible with that of Baly, also regards thechlorophyll molecule as taking an actual part in the chemicaltransformation of carbon dioxide to formaldehyde, the chlorophyll-carbon dioxide complex being supposed to contain a bicarbonate-like grouping attached t6 the magnesium atom; this grouping isregarded as changing to a f ormaldehyde-peroxide complex, whichthen splits off as formaldehyde and oxygen.Maquenne’s view issomewhat similar .36 Recent work by 0. Warburg and T. Uyesugi 37on the parallelism between the action of hydrogen cyanide and sub-qtituted urethanes on the rate of decomposition of carbon dioxideby ChZordkt and on the decomposition of hydrogen peroxide is heldto support the views of Willstatter and Stoll, but it would appear tobe equally favourable to any other hypothesis in which the decom-position of a peroxide is an essential feature.It has long been recognised that there is some other internalfactor in the green leaf, associated with the protoplasm, which34 Ber., 1915, 48, 1540; 1917, 50, 1777.35 J., 1921, 119, 1025.37 0.Warburg and T. Uyesugi, Biochem. Z., 1924, 146, 486; A . , i, 922.36 Ann. Reports, 1923, 20, 220.See also J. Poklo, Chem. News, 1924,129, 90; A., i, 1018BIOCHEMISTRY. 185regulates photosynthesis ; Willstatter and Stoll were compelled totake this into account in the interpretation of their results, andthey postulated the existence of a special enzyme which plays anessential part in the assimilatory process. The results recentlypublished by H. A. Spoehr and J. M. McGee38 indicate that thereis present in the leaf something that absorbs carbon dioxidechemically, and that the agent responsible for this is a protein.This conclusion is of interest in connexion wit,h a new hypothesisregarding the mechanism of carbon assimilation, which has beenput forward by Wo.O ~ t w a l d , ~ ~ and assumes that there is theproduction of a protein-carbon dioxide compound as the firststage of the process. This is supposed to be accompanied by theautoxidation of a lipoid with the formation of a lipoid peroxidesparingly soluble in water.40 The protein-carbon dioxide compoundand the lipoid peroxide then interact in the presence of water withthe production of formaldehyde and oxygen, and the lipoid peroxideis regenerated by autoxidation.According to this hypothesis, thephotochemical reaction is not a photo-reduction, but a photo-autoxidation. The whole of the process is supposed to take placea t a protein-lipoid interface. An important difference betweenthis hypothesis and that of WiUstatter and other workers is that intlhe new hypothesis chlorophyll takes no part in the actual chemicalreaction of conversion of carbonic acid to formaldehyde, but isconcerned in promoting the photo-autoxidation of the lipoid.Although not necessarily supporting the formaldehyde theory ofcarbon assimilation, the fact that green plants can utilise formalde-hyde in low concentrations is of interest as showing that this theoryis not incompatible with the anabolic potentiality of the green plant.T.Sabalitschka and H. Riesenberg 41 have supplemented theirearlier observations, and those of earlier workers, that green plantscan assimilate formaldehyde in the dark with the formation ofsugar and starch.The first products of carbon assimilation the presence of whichcan be actually demonstrated in the green leaf are carbohydrates.The classical work of Brown and Morris 42 led to the conclusion thatcane-sugar was the first recognisable carbohydrate produced bycarbon assimilation, and the later work of Davis, Daish, andSawyer,43 and of other investigators, lent support to this conclusion.38 H. A. Spoehr and J-. M. McGee, Science, 1924, 59, 513; A., i, 1392. '' Wo. Ostwald, Kolloid-Z., 1923, 33, 356; A., i, 250.40 Compare p. 188.dl T.Sabalitschka and H. Riesenberg, Biochem. Z., 1924, 144, 545, 651;42 J., 1893, 63, 604.43 J. Agric. SOC., 1916, 7, 225.145, 373; A., i, 475, 698186 ANNUAL REPORTS ON THE PROGRESS OF CHEXISTRY.The question has now been reopened by Weevers,& whose methodof investigation was to study the carbohydrates present in the greenand the non-green parts of variegated leaves. He found onlysucrose in the non-green parts, but in the green parts he found alsomonoses. Moreover, when full-grown leaves (of Pelargonium) wereentirely depleted of sugar and starch by keeping the plants in thedark, and were then exposed to sunlight, the first sugars that couldbe identified were monoses, sucrose and starch appearing onlylater. Weevers therefore concludes that monoses are the firstsugars to be synthesised during the process of carbon assimilation.It has always been difficult to see why sucrose need be an essentialstep in the synthesis of carbohydrates by the plant, and confirmationof these results will be awaited with interest.The investigations of Baly and his co-workers on the photo-synthesis of carbohydrates in vitro by the action of ultra-violet lighton carbonic acid have been carried an important step further bythe isolation from the product of methylation of the photosyntheticsyrup, by J.C. Irvine and G . V. Francis,45 of a product that appearsto be a tetramethyl hexose. From its amount it appeared thatabout 10% of the synthesised material consisted of hexose, thebulk of the syrup consisting of non-sugar compounds containinghydroxyl groups.Synthesis of Polysaccharides in Cereals.The mechanism of the synthesis of starch in cereals has been thesubject of much work and of still more speculation in the past. Onthe assumption that the building up of starch from soluble sugarspasses through the same stages as those observed in the enzymicdegradation of starch, the presence of dextrins in the tissues ofcereals has been sought for. Some workers (e.g., PBligot, Payen,Hkbert) claimed to have found dextrins, whilst others (Dehdrain,Muntz) failed to do so.This question has recently been rein-vestigated by B e l ~ a l , ~ ~ who has studied the carbohydrate contentof the tissues of various cereals at various stages of maturity. I nno case could he find any trace of dextrins, and he advances evidencethat the soluble non-reducing substances regarded as dextrins byearlier workers were really mixtures of a 12evulosan with sucrose.As a result of his investigations, Belval divides common cerealsinto two groups.I n one group, of which maize is typical, the only44 T. Weevers, Proc. K . Akad. Wetensch. Amsterdam, 1924, 27, 46; A,,i, 810.46 J. C. Irvine and G. V. Francis, J . Ind. Eng. Chem., 1924, 16, 1019;A . , i, 1286.46 H. Belval, “ La Geneso de L’Amidon dans les C6rbales.” Kernours,1924, pp. 1-62; Rev. gin. Bot., 1924, 38, 308BIOCHEMISTRY. 187soluble carbohydrates found in the stems of the plant during growthare glucose, fructose, and sucrose, that is, the same as are found inthe green parenchyma of the leaves.In the other group, to whichbelong wheat, barley, oats, and rye, there is also found a 1Eevoro-tatory soluble lzvulosan, apparently identical with the " lkvosine "isolated from wheat, rye, and barley by T a r ~ e t . ~ ' This substanceis found in considerable amount in the stems and grain of the im-mature plants. Its function is considered to be that of a temporaryreserve material, formed at those stages of the plant's growth atwhich soluble sugars are being produced in the leaves and trans-ported to the developing seeds a t a rate greater than that a t whichthe latter can build them up into starch. The plant converts thisexcess of soluble sugars into the high-molecular polymeride in ordert o avoid the osmotic disturbances that would ensue if large con-centrations of simple sugars accumulated in the tissues.Later on,after the rate of starch formation in the seeds has equalled that ofsugar supply to them, this temporary reserve of l~evulosan disappears.It is not suggested that this IEevulosan is an intermediate step in thebuilding up of starch from soluble sugars. Its conversion to starchin the grain is probably preceded by its hydrolysis to laevulose.During the germination and malting of barley there is a con-siderable production of pentosans, which must be formed from thereserve hexosans of the seed, although whether from the starch ofthe endosperm or from hemicelluloses is notTranslocation of Sugars and their Metabolism.I n view of the increasing importance that is being attached tothe relation between carbohydrates and phosphates in the transportof calcium in the blood, in ossification, and in the metabolism ofcarbohydrates in animal it is of interest to note that recentinvestigations lay stress on the importance of phosphates in thetransport and metabolism of carbohydrates in the plant.Thus,M. H. van Laer and R. Duvinage find that, during the germina-tion of barley, the mobilisation of the carbohydrate reserves isaccompanied by a mobilisation of phosphate, so that the phosphorusof thc endosperm is rendered soluble and migrates in this form to theembryo. Moreover, the amount of phosphorus thus transportedto the embryo is proportional to the amount of growth made by the48 31.H. van Laer and A. Masschelein, Bull. Soc. chim. Belg., 1923, 32,402; A , i, 476.4B See p. 202.C'ompt. rend., 1891, 112, 293; Bull. Soc. chim., 1891, [iii], 5, 724.&I. H. van Laer and R. Duvinage, Bull. SOC. chim. Belg., 1923, 38, 355;A., i, 260188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.latter-a fact which suggests that there is a definite chemical relation-ship between the migrating sugars and the phosphates. C. J.L y ~ n , ~ l in an investigation of the effect of phosphates in therespiration of Elodea mnadensis, has found a definite relationshipbetween the rate of respiration and the phosphate concentration ofthe medium. Here again we have an instance of the importance ofphosphates in a process consisting essentially in the oxidation ofcarbohydrates.The mechanism of oxidation in the plant is a question theclose relation of which to the process of plant respiration isobvious.The oxidising system of the plant is now commonlyacknowledged to consist of two components, a peroxide or“ oxygenase ” and a peroxydase. The chemical nature of thesecomponents, and of their interaction forms the subject of threeinteresting papers by Gallagher.52 The oxygenase appears to be alipoid material which is autoxidisable, with the production of aperoxide of the superoxide (Mendel6ev) or antozonide (Schonbeim)type (R<Z). The peroxydase also appears to be organic in nature,and according to Gallagher’s work on the mangold peroxydase, it isderived from an aldehyde. The inactivation of peroxydase byboiling is not accompanied by the loss of aldehyde properties in thepreparation, and moreover, the heat-inactivated peroxydasebecomes reactivated on standing. Since iron was present in theseperoxydase preparations, and since iron salts, when added toaqueous solutions of aliphatic aldehydes, caused an increase in theperoxide activity already exhibited by the aldehyde solutionsalone, it is concluded that the zymogen or precursor of the activeperoxydase is an aldehyde, which is oxidised, under the catalyticinfluence of iron, to a peroxide of the polyoxide (Mendelkev) orozonide (Schonbein) type (R = 0).The mode of action of theoxygenase-peroxydase system is then supposed to consist in thecombination of the two types of peroxides with the production of asubstance with an oxidation potential comparable with that ofozone and higher than that of either of the reactants, this compoundbeing the actual oxidising agent :0 R,= O < ~ > R ~ .Oxygenase.Peroxydase.There are naturally still many points to be investigated beforethe validity of this hypothesis can be regarded as well established,s1 C. J. Lyon, J . Ben. Phyaiol., 1924, 6, 299; A., i, 476.52 P. H. Gallagher, Biochem. J., 1923, 17, 515; 1924, 18, 29, 39; A.,1923, i, 1159; 1924, i, 595BIOCHEMISTRY. 189but the results so far obtained are promising, and the furtherprogress of this work will be watched with interest.Nitrogen Fixadion by Green Plants.I n the Report for 1922 reference was made to the publicationby C.B. Lipman and J. K. Taylor 53 of a preliminary note in whichit was stated that evidence had been obtained for the fixationof atmospheric nitrogen by wheat plants. A detailed account ofthis work has now appeared75* and it is thus possible to examinethe evidence carefully.The analytical data given by Lipman and Taylor with regardto wheat and barley plants grown in liquid culture either devoidof nitrogen or containing varying amounts of nitrate leave littleor no room for doubt that there was an actual fixation of atmo-spheric nitrogen. The authors devote considerable attentionin their paper to the question of whether this fixation could havebeen caused by bacteria in their cultures. They bring for-ward many arguments in favour of the view that bacterial inter-vention of this kind cannot have occurred, and they claim thattheir results “prove that the nitrogen gained by our cultures a tthe expense of the nitrogen of the air was not first fixed by bacteriaand then passed on to the plant.The fixation of nitrogen musthave occurred directly, and probably occurs in the cells of the greenleaves. ”It is not possible here to consider Lipman and Taylor’s argumentsin detail. Although the cogency of many of these arguments isopen to question, they have certainly made out a case. Indiscussing the merits of earlier work on the same subject, theyreject as untrustworthy and inconclusive all earlier work on whichclaims for the fixation of nitrogen by green plants have been basedwith the exception of that of Mameli and P o l a ~ c i .~ ~ To this work, aswell as to that of Lipman and Ta’ylor, the objection still applies that,although it is not possible to affirm that the nitrogen fixationobserved was caused by contamination with bacteria, and althoughLipman and Taylor have made out a plausible case for thinking thatsuch was not the case in their experiments, the possibility stillexists. However strong may be the presumptive evidence in favourof the fixation having been effected actually by the plants themselves,the point cannot be accepted as conclusively proved until experi-ments have been carried out under conditions excluding the possi-bility of bacterial intervention. Lipman and Taylor state that5s Ann.Reports, 1922, 19, 222,54 C. B. Lipman and J. K. Taylor, J . Franklin Inat., 1924, 198, 475; A.,5 5 Atti Instit. Bot. Pavia, 1911, 15, 159.i, 1276190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.they are planning further experiments on these lines, the resultsof which will be awaited with great interest.Even if we admit the possibilty of nitrogen fixation by greenplants such as wheat, it is difficult to suppose that it can be a factorof any economic importance. I n Lipman and Taylor's experi-ments the wheat plants that were grown without the addition ofany nitrogen were very stunted ; although they remained healthyand continued to form new growth for 24 weeks, there was nocomparison between the amount of growth and that given by theplants which received nitrates.Indeed, agricultural experienceleaves no possible room for doubt that large and economic yieldsof wheat cannot be grown unless there is available to the growingplant a sufficient supplly of combined nitrogen in an assimilableform. This does not detract from the very great theoretical interestattaching to the possibility of limited nitrogen fixation by greenplants, nor from the importance attached by Lipman and Sharpto the cumulative effect that such limited fixation would have,when exerted by successive generations of plants growing undernatural conditions, in building up a supply of combined nitrogenand thus in the course of time contributing materially to the nitrogencompounds on the earth's surface.The Synthesis and Metabolism of Proteins in Plants.of Aspnragine.That nitrates are t,he form in which most plants obtain nitrogenfrom the soil is well known; ammonium compounds, although theymay be absorbed directly by plants, are usually less suitable.Thisfact is emphasised by the recent experiments of E. B. Fred,56 whofound that when barley was grown in sterile sand cultures in whichnitrogen was supplied as ammonium sulphate, the yield obtainedand the percentage of nitrogen in the crop were much less thanwhen pure cultures of nitrifying organisms were added to the other'-wise sterile sand.This favoured position of nitrates is all the more difficult to under-stand when it is remembered that the proteins and other organicnitrogen compounds synthesised by the plant are all derivativesof ammonia, and that therefore in the conversion of nitrates intoproteins, reduction of nitrate to ammonia or its derivatives mustoccur.Why is it that, in order to transform nitrogen from theform of organic derivatives of ammonia in the soil into organicderivatives of ammonia in the plant, it is necessary for ammoniato be oxidised to nitrate in the soil before absorption, only for theprocess to be reversed, and ammonia derivatives to be reformed inThe R61es6 E. B. Fred, Soil Sci., 1024, 18, 323; A,, i, 2393BIOCHEMISTRY. 191the plant? Not until very much more is known of the chemicalprocesses going on in the living plant will it be possible to answerthis question, but it is important to bear in mind that the absorptionof nitrate ions implies also the absorption of kations, chiefly Ca**,whereas the absorption of ammonium ions implies the absorptionof anions.Investigations of the reaction of plant juices and ofthe mutual relations of different kations in the nutrient solutionand in the plant will probably throw much light on this question;in particular, the d e of calcium in the absorption of nitrogen bythe plant and in the synthesis of proteins therein is a fruitfulsubject of investigation (see p. 195).the conversion of nitrates to amino-acids in the plant demands thepreliminary reduction of nitrates only to the stage of nitrites.Protein synthesis in the lezf then becomes actually a photosyntheticprocess in its first stage-the production of activated formaldehyde,which reacts at once with nitrite.Whether this is true, or whetherprotein synthesis can also go on in the leaf without the interventionof light, is not yet definitely established, but it is certain that theresynthesis of proteins in other parts of the plant, as in the seed,is independent of light, and evidence is accumulating that thissynthesis is one in which ammonia and soluble sugars are theinitial substances. The occurrence of the same process in the leafin darkness would therefore appear to be possible.The power to reduce nitrates through nitrites to ammonia hasbeen found by S. H. Eckerson 58 to be possessed by extracts fromvarious parts of the tomato plant. This reduction occurred activelyin the light or in the dark, and also in boiled extracts, providedthat a faintly alkaline reaction (pa 7.6) was maintained. I n viewof the importance that is being ascribed to iron in the oxidativeprocesses of the plant (see p.209), it is interesting to note that theresults of Eckeraon indicate that the presence of iron is also probablyan important factor in the nitrate-reducing power of plant extracts.59I n recent years, considerable attention has been directed to theoccurrence of asparagine in plants and to the part that this substancemay play in the translocation of nitrogen and in protein metabolism.A recent paper by H. E. Woodman and F. L. Engledow,60 in whichthe development of the wheat grain has been followed with specialreference to the synthesis of the proteins of the grain, provides itconvenient opportunity for summarising the position of this part67 Ann. Reports, 1922, 19, 220.6 8 S.H. Eckerson, Bot. Gcaz., 1924, 67, 377. See also V. L. Anderson,59 See also 0. Baudisch, J . Biol. Chem., 1921,48,489 ; Science, 1923,57,451.6o J. Agri. Sci., 1024,14, 563.According to t(he hypothesis of Baly, Heilbron, andA m . Bot., 1924, 38, 699; A., i, 1393192 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the subject. Prom the fact that at no investigated stage inthe development of the grain could nitrate be detected, it is con-cluded that the reduction of nitrate to ammonia occurs a t somepoint exterior to the grain, and that the nitrogen for protein syn-thesis enters the grain either in the form of amide (asparagine)or ammonium compounds or both.Various earlier workers havenoted that whenever the a!mount of protein in leaves underwentdiminution, there was a corresponding appearance of asparagine,and it was suggested that asparagine was the nitrogenous substanceconcerned in the elaboration of protein in the plant. The morerecent work of Prianischnikov 61 and of Chibnall 62 has considerablyamplified this view. According to Prianischnikov and Schulov,asparagine synthesis occurs in the plant whenever an excess ofammonia is present, caused either by rapid uptake of nitrogen bythe roots or by deamination in the plant tissues. Smirnow's 63work on the metabolism of the lupin embryo has led him to similarconclusions. Prianischnikov draws an analogy between the func-tion of asparagine in the plant and that of urea in the animal organ-ism.I n young plants, when protein metabolism gives rise toammonia, which is toxic if present above a certain concentration,the ammonia is rendered harmless by condensation with asparticacid to form asparagine. Chibnall has demonstrated the occurrenceof fhe same process in the mature leaf under certain conditions.Plants therefore remove ammonia as asparagine, whilst in the animalit is rendered harmless by conversion into urea,.Urea is a wasteproduct in the animal organism, and is excreted. I n the plant, onthe other ha,nd, aspara'gine is a temporary reserve in which form anexcess of ammonia may be stored in a harmless and mobile con-dition, to be utilised for protein synthesis as soon as further suppliesof carbohydrate become available from the leaves.Prianischnikovfound that in seedlings the a m u n t of asparagine formed was depen-dent on the amount of carbohydrate available. Excess of carbo-hydrate led to the conversion of asparagine into amino-acids andproteins, and in the absence of carbohydrates the reverse changetook place : protein degradation with the formation of asparagine.Chibnall's results support this view. He finds that asparagineis the chief product of metabolism of proteins in the mature leaf,and he concludes that this type of protein degradation is the chiefmeans whereby the plant is able to convey nitrogen, in a formM. Prianischnikov and Schulov, Ber.deut. Bot. Gea., 1910, 28, 253;M. Prianischnikov, Lartdw. Vers.-St., 1922, 99, 267; Rev. gen. Bot., 1924,No. 423, 108.The analogy must not be pushed too far, however.02 A. C. Chibnall, Biochem. J., 1924, 18, 387, 395; A., i, 810.A. Smirnow, 2. PfEanz. Dhhg., 1924, [A], 3, 30BIOCHEMISTRY. 193suitable for easy resynthesis of prctein, from one part of the plantto another. The work of Vickery 64 on the nitrogenous constituentsof the juice of the lucerne plant has also shown that asparagineis an important constituent.Modern work therefore ascribes to asparagine a dual functionin the plant : (1) An innocuous storage material for nitrogen,whereby the ill effects of excess of ammonia in the plant are avoided.(2) A mobile form of nitrogen, in which ammonia is transportedfrom one part of the plant to another.Woodman and Engledow conclude from their results and fromthe above considerations that nitrogen for protein synthesis entersthe developing wheat grain in the form of asparagine derived fromprotein degradation in the leaves.There is little or no evidenceregarding the course of the reactions whereby the asparagine andcarbohydrates are converted into protein. These workers believefrom their results that ammonia is regenerated from the asparagine,and that ammonia forms the actual starting point of protein syn-thesis in the grain. There is little evidence for the extensive exist-ence of amides in the plant, and it is suggested as more probablefhat amino-acids are synthesised from a-hydroxy-acids (producedfrom carbohydrates) by a reversal of the normal deamination pro-cess ; in this way, alanine might be formed from lactic acid, Directexperimental confirmation of the occurrence of this process in theplant is lacking.The subsequent condensation of amino-acids to proteins is readilyformulated. The presence of proteoses and of polypeptides inthe grain has been demonstrated, and it would thus appear that thebuilding up of proteins from amino-acids goes through the normalstages already familiar in the reverse process of the enzymicdegradation of proteins.Absorption by Plant Roots. " Feeding Power '' of Plants.It is generally supposed that the elements that the plant obtainsby means of its roots are absorbed in the form of ions. The con-ditions determining the rate and amount of absorption of any ionare very complex.A large amount of valuable work is being doneon this subject by Hoagland and other workers in California. Thetime is not yet ripe for a detailed discussion of the results obtained ;it may, however, be mentioned that there is definite evidence thatthe absorption of an ion is influenced by the nature of other ionsof the same or of opposite charge, and that the concentration of thesolution has an important influence on the magnitude of this effect.Moreover, there is no obvious relation between the ordinary chemicalREP.-VOL. XXT. HH. B. Vickery, J. BWZ. Chem., 1924, 60, 647; A., i, 1275194 ANNUAL REPORTS ON THE PROGRESS 017 CHEMISTRY.and physical properties of ions and their rates of penetration intoplant cells : the character of the cell membrane must be taken intoaccount.Plant cells may contain ions in far higher concentrationsthan those in the medium in which they are growing ; it is thereforenecessary to take into account the energy relations of the absorption.It was in view of considerations of this type that A. R. Davis,D. R. Hoagland, and C. B. Lipman 65 took vigorous exceptionto the hypothesis of Truog 66 on the " feeding power " of plants.Truog believes that the difference between the rate and extentof absorption of essential elements by different types of plant isconditioned by differences in the reaction cf the cell sap, and thatthe relationships involved can be interpreted in terms of the lawsof mass action.Davis, Hoagland, and Lipman are of the opinionthat Truog under-estimates the fact that differences between thecomposition of plants may be caused, not by diff erenccs in the specificabsorbing powers of individual cells, nor yet by the specific reactionof the cell sap, but by the difference in extent of the root system,and the difference in the amount and intensity of carbon dioxideproduction by roots. They cited the results of Newton 67 insupport of this contention. F. W. Parker,G* who was associatedwith Truog in the earlier work of the latter investigator on thissubject, has now published a paper giving the results of a furtherinvestigation on this question. By comparing the amounts ofcarbon dioxide excreted from the roots of various plants with theabsorption of various elements as shown by the composition of theresulting plants, he has shown that there is no relation betweencarbon dioxide production and the " feeding power " of the plantsfor calcium, magnesium, phosphorus, and potassium.Buckwheatis a conspicuous example : although the carbon dioxide producedby the roots of this plant was very small, it absorbed a larger amountof these elements than other plants which excreted large amountsof carbon dioxide from their roots. Hence, if we accept Parker'svalues for carbon dioxide production by plant roots, his resultsare in favour of Truog's hypothesis to the extent that they indicatethat there is some specific difference in plants, apart from the extentof their root system and the excretion of carbon dioxide by theirroots, which determines their ability to absorb essential elementsfrom the soil.It must, however, be borne in mind that measure-ments of the carbon dioxide prodrxction in the soil in which plantsare growing, as carried out by Parker, are not necessarily a measure6s Science, 1923, 57, 299.E. Truog, Wis. Ayr. Exp. &a. Rcs. Bull. 41, 1916; Scicncc, 1022, 56,294.6 7 Ann. Reports, 1923, 20, 223.68 F. W. Parker, Soil Sci., 1924, 17, 229; A., i, 811BIOCHEMISTRY. 195of the actual excretion of carbon dioxide by the roots themselves.Different plant roots may give rise to different amounts of organicmaterial to serve as food for soil organisms, which would thuscontribute to different extents to the total carbon dioxide pro-duced.It is conceivable that the high production of carbon dioxidein the soil on which plants poor in essential elements (relativc tobuckwheat) are growing may really be an indication of high bac-terial activity in that soil. This high bacterial ackivity might thenresult in a high degree of absorption of the elements in questionby bacteria, with a consequent diminution in the amount availablefor the plant.69 To test that point it would be necessary eitherto repeat the experiments of Parker in sterile soil, or to includemeasurements of bacterial numbers and of the concentration of thesoil solution in the soil in which the plants were growing.I n general, recent work in this field has laid special stress on theimportant part played by calcium in the plant.This element isintimately connected with the permeability of plant cells. Accord-ing to the disputed theory of Truog, calcium is also needed for theneutralisation of organic acids in the plant, and since these acidsare supposed to be intimately concerned in the synthesis of proteins,a relation is traced between the amounts of calcium and of nitrogenin the plant. Calcium starvation brings about serious physio-logical disturbances in the plant. This subject has been studied inCalifornia by H. S. Reed and A. R. C. H a a ~ , ~ ~ with special referenceto the growth of trees. Trees starved of calcium developed mottledor spotted leaves, which were soon shed, and the trees slowly died.The abnormal mottled leaves had a low content of calcium.Theauthors direct attention to the similarity between this experiment-ally produced physiological disturbance and that occurring oncitrus trees in the field. Kelley and Cummins 71 have shown thatin the latter case the mottled leaves are also deficient in calcium,and that the sap of these leaves contains more than twice as muchfree acid as that of normal unmottled leaves. Reed and Haas 72have also shown that the injury to walnut seedlings from solutionsof high alkalinity is due not so much to the high hydroxyl-ionconcentration in the plant as to the absence of calcium.Some very sixggestive results have been published by Geri~ke.~3He found that when wheat plants were grown in solution cultureSee Ann.Reports, 1923, 20, 214; Bee also J. Stoklass, Ber. deut. But.Ges., 1924, 42, 183; A., i, 1018.70 H. S . Reed and A. R. C. Haas, California Agr. Expt. Sta., Tech. Paper,1923, 4, 21 pp. ; A., i, 923.W. P. Kelley and A. B. Cummins, J . Agric. Rea., 1920, 20, 161.72 H. S. Reed and A. R. C. Haas, Amer. J Bot., 1924, 11, 78; A., i, 922.i 3 W. F. Gericke, Science. 1924, 59, 321.H196 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in a medium containing all the essential elements, and then aftera month were transferred to a solution from which potassium wasomitted, the rate of growth and the final yield of dry matter weremuch greater than those of plants grown throughout in the “ com-plete” solution. I n view of the fact that there is some evidencefrom earlier work that nitrate and potassium are “ physiologicallypaired ” ions, that is to say, that nitrate is the anion that predomi-nantly determines the availability of the potassium ion to the cerealplant, Gericke advances the idea that the rapid depletion of nitratefrom the soil by the growing plant, as has been demonstrated bythe work of Stewart,74 results in a low availability of potassiumto the plant after the initial period of active nitrate absorption,and that this low availability is of advantage, acting to produceincreased crops, earlier maturity, and greater vegetative activity,in the same way as when his experimental plants were transferredto the solution deficient in potassium.Gericke has since obtainedsimilar results from the omission of phosphate from the culturesolution.75 The work is yet in its early stage, but the resultspromise to have an important bearing on the study of crop nutrition.‘‘ Auximones . ’ ’A few years ago, widespread interest was aroused by the workof Bottomley on the influence of organic substances on plant g r o ~ t h .7 ~Basing his conclusions on experiments in liquid culture with Lemna,Bottomley concluded that the green plant needed for its propergrowth and development growth-promoting accessory factorssimilar to the vitamins needed by animals. To these organic sub-stances he gave the name of “ auximones.” A commercial prepara-tion known as “ humogen,” or bacterised peat, was put on the marketbut trials at Rothamsted and elsewhere gave disappointing results.Recently the subject has been investigated by N.A. Clark and E. M.Roller.77 These investigators found that Bottomley ’s resultscould be explained by the fact that the composition of the inorganicculture solution used by Bottomley was not suited to the continuedgrowth of Lemna, and that although the addition of peat extract tomoribund cultures did cause an increase in the growth rate, itdid not nearly bring it back to the initial growth rate infresh culture liquid free from organic matter. Clark and Rollerhave utilised a mineral salt solution better suited to the needs ofLemna, and by this means they were able to keep the plant growingwith unimpaired vigour, and a t a rate almost equal to that obtained74 G.R. Stewart, J . Agric. Res., 1918, 12, 311.7 5 W. F. Gericke, Science, 1924, 60, 297.7 6 See Ann. Reports, 1916, 13, 232; 1917, 14, 232; 1920, 17, 191.77 N. A. Clark and E. M. Roller, Soil Sci., 1924, 17, 193; A., i, 809BIOCHEMISTRY. 197in the soil, for four months, during which time it passed throughmore than twenty generations. Whether organic substances existwhich can cause a further increase in growth rate in this mediumis not yet determined, but it would appear that in any case suchsubstances are not essential for the growth and reproduction ofLemna, and probably not for any green plants. There is thusno basis for the analogy with vitamins.B i o c h e m i s t r y of A n i m a l s .Xigni$cccnce of Phosphates in the Cell.Since the discovery of hexosediphosphate and its r6le in alcoholicfermentation by Harden and Young nearly 20 years ago, attentionhas constantly been attracted, to a greater or less extent, to therelation between phosphates and the sugars in living cells.Many of the views recorded in this field have been highly speculative,and whilst more than one hypothesis has served a useful purpose,they have, as a general rule, lacked adequate experimental founda-tion. The researches published during the last year or two haveprovided much that was missing, and the outlook in this quarteris more encouraging than it has been for some time past.Calcification of Bone and Teeth.Reference was made in last year’s Report to the discovery byRobison 7s of a hexose monophosphoric ester, yielding a, solublecalcium salt, which may be hydrolysed by an enzyme present inossifying cartilage, and it was remarked that the importance ofthese facts would be far-reaching if it could be demonstrated thatsuch a compound normally exists in the blood.Goodwin andRobison 79 have now produced satisfactory evidence that compoundsof this type do occur in the blood, but they have not yet sufficientlypurified the isolated substances to establish their actual nature. Twophosphoric esters were isolated, and one of these, showing reducingproperties and optically lzevorotatory, is hydrolysed by the enzymefound in ossifying cartilage. This is an important observationand greatly increases the significance of the work to which attentionwas directed last year.If, then, we imagine the calcium phosphatebeing carried by the blood in this relatively soluble form to centresof calcium deposition, such as the developing bones or teeth, it isnecessary to consider the mechanism by which the salt is actuallyhydrolysed there and the salts are deposited. Papers by Robisonand Soames,80 and Kay and Robison assist us to gain a clearer78 Ann. Reports, 1923, 20, 188.79 Biochem. J., 1924, 18, 1161; A., i, 1365.Ibid., p. 740; A., i, 904. *l Ibid., p. 765; A., i, 904198 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.picture of these changes. The enzyme which hydrolyses themonophosphoric ester is present in bones and teeth and also inthe kidneys and intestines.I n the young animal, its activity inthe first two sites would appear to be more marked than in laterlife, but its activity in the kidney and intestines seems to be lessvariable with age. At body temperature, the enzyme showsgreatest activity at hydrogen-ion concentrations between pH 8.4and 9.4. This fact, together with observations suggesting that inbone the enzyme is normally secreted in the region of the osteo-blasts, raises the question whether these cells or the hypertrophiccartilage cells have the power to raise the pH of tissue fluids. Directtests indicate that they have this power, but the results are as yetindefinite. In any case, it is necessary to consider the physico-chemical system represented by the calcium compounds presentin blood and tissue fluids.It has been known for some time pastthat a variable proportion of the calcium present in serum will notpass a dialysing membrane.s2 In a recent examination of thismatter by Loeb and Steinberger,s3 the proportion passing the mem-brane was found to be, in some cases, as low as 55% when dialysedagainst water. When dialysed against 0.8% sodium chloride solutiona t pn 7-4, or against hydrochloric acid a t pH 2-5, all the calciumpassed through the membrane. These results would appear toindicate an equilibrium between dialysable and non-dialysablecalcium in the serum, and are supported by the work of Clark,s4who found the proportion of diffusible cal.cium raised after exposureof serum to ultra-violet radiations. Their belief that all the calciumpasses through the membrane when dialysis against physiologicalsalt solution is employed, is not in accordance with other results.The general view appears to be that the non-diffusible calcium isin combination with protein.Even if we subtract the amountof calcium present in this condition, there still remains that presentin diffusible forms, the concentration of which is considerablygreater than that of saturated solutions of calcium carbonate andphosphate. This has led some authorities to view the serum as ametastable super-saturated solution of calcium salts.85 As Robisonand Soames remark: " To consider the plasma as supersaturatedwith respect to calcium carbonate and phosphate does not seemjustified until more is known of the factors influencing the degreeof ionisation and the solubility product.A supersaturated solutionmight, it is true, deposit calcium salts only on coming into contactwith the solid phase, i.e., bone, but this would not explain the begin-a2 A. R. Cushny, Ann. Reports, 1920, 17, 161.83 J. Gen. Physiol., 1924, 6, 453; A., i, 783.6 p Amer. J. Hyg., 1923, 3, 481; A., i, 1253.Ronn and Takahashi, Biochem. Z., 1913, 49, 370BIOCHEMISTRY. 199ning of ossification in embryonic cartilage.” If, then, for sakeof argument the body fluids be regarded as saturated solutionsof calcium carbonate and phosphate, deposition of these salts mustoccur if the concentration of the ions rises. The concentration ofPO4”’ ions will rise if there is an increase in inorganic phosphate,or if there is a shift of pH towards the alkaline side.Hence the boneenzyme, working between pE 8.4 and 9.4, if the assumption is allowedthat the osteoblasts possess the power to raise the pH in their imme-diate vicinity, will cause deposition of tricalcium phosphate. Itis interesting to observe that, as the equilibrium between HCO,’and CO, will also be shifted by the change of reaction, there willtend to be deposition of calcium carbonate. On these groundsRobison explains the 10% or so of this substance that is normallyfound in bone. Bassett 86 has shown that the solid phase inequilibrium with solutions containing calcium and phosphate,under conditions found in normal serum, is hydroxyapatite,( Ca3P208),,Ca(OH),, a compound more basic than tertiary calciumphosphate.It is therefore, as Robison points out, surprising thatHowland and Kramer,B7 amongst others, should suggest that thesolubility product GaHPO, is the limiting factor in the depositionof bone. Both these workers, as well as Kugelmass and Shohl,88have, in their treatments of the subject, regarded the concentrationof PO4”’ at pH 7.4 as so low as to be negligible, and have, withoutquestion, been led seriously astray thereby.The work of Robison and his colleagues has been so carefullycontrolled at every step, and their results are so unequivocal, thatone can scarcely doubt that at last a clear picture is being obtainedof the mechanism by which calcium is normally deposited in teethand bone.There is little to attract one to the alternative mechanism offeredby Freudenberg and Gyorgy,8g according to which the physio-logical fixation of lime takes place in three stages :Cartilage protein + Ca = Ca-cartilage-protein,Ca-cartilage-protein + phosphate = Ca-cartilage-protein-phos-Ca-cartilage-preotein-phosphate = calcium phosphate + car-phate,tilage protein,and it is not surprising that this view has been criti~ised.~O8 G J., 1917, 111, 620.u8 J .Biol. Chem., 1924, 58, 649.~79 Biochem. Z . , 1923, 142, 407; Ergeb. inn. med. Kindersheilk., 192.3, 24.R. E. Liesegang, Biochem. Z., 1924, 145, 96: A., i, 587.Monateh. Kindersheilk., 1923, 25, 279.17200 ANNUAL REPORTS ON TRE PROGRESS OF CHEWSTRY.The other localities where this particular enzyme has beenfound, namely the intestines and kidneys, suggest that it is thereconcerned with the absorption and excretion of calcium and phos-phates, but this field is as yet unexplored.Rickets.The bearing of these studies on ossification on the much debatedquestion of the etiology of rickets is a t once obvious, although it.is, as yet, not clear how far they enable us to gain a true picture;of the abnormalities which characterise this disease.During the past year further evidence has been forthcomingthat normal bone formation will not take place in the absence ofan organic constituent of certain normal foodstuffs, which hasbeen provisionally termed vitamin-D, or the anti-rachitic vitamin.g1A deficiency of this dietary factor leads to a fall in the calciumand inorganic phosphate content of the blood, which is made goodwhen the diet is rendered adequate, or, alternatively, when theanimal is exposed to ultra-violet r a d i a t i ~ n .~ ~ The very surprisingexperimental results of Hume and Henderson Smith, to whichattention was directed in last year's Report,g3 have not been con-firmed by Webster and Hill,94 and at present the whole questionof the mode of action of ultra-violet radiation in these cases is in aconfused state. It is possible that the remarkable experimentsof Steenbock and Black,g5 who found that food deficient in the fat-soluble vitamins may be rendered adequate by exposure to ultra-violet radiation, will do something to clear up the confusion.Theresults of Clark,s4 referred to above, also strike one as of considerableimportance. Meanwhile, it would appear wise to defer furtherdiscussion until the matter has received further investigation. How-ever, this brief reference to rickets will serve to connect our discus-sion of the calcium and phosphoric acid of the blood with anotherpathological condition that is itself in certain forms associatedwith rickets, namely, tetany.Tetany.Shipley 96 has remarked recently in a valuable review on rickets :'' The general character of the relationship of infantile tetany torickets has become apparent, but the exact nature of t.he metabolic91 Shipley, Kinney, and McCollum, J. Biol. Chem., 1923, 59, 165, 177;u2 Goldblatt, Biochem. J., 1924, 18, 414; A ., i. 788,93 See Ann. Reports, 1922 and 1923.94 Ibid., p. 340; A., i, 340.Q 5 J . Biol. Chem., 1924, 61, 405.Q6 Physiol. Rev., 1923, 3, 106.A . , i, 685BIOCHEMISTRY. 201disturbance necessary for the development of tetany continues toremain obscure.”Whilst he is wise in showing caution, we have a t least one well-established fact to work upon, namely, that both infantile tetanyand that following extirpation of the parathyroid glands are asso-ciated with a low concentration of calcium in the blood, and thattreatment with calcium salts usually leads to rapid improvement.Before discussing recent work in this field, it is necessary to referbriefly to the elaborate studies from Professor Noel Paton’s laboratoryon tetania parathyreopriva which have been fully reported previ-ously in these Briefly, it may be stated that Patonproduced evidence which he regarded as sufficient for concludingthat extirpation of the parathyroid glands results in a disorganisationof the mechanism by which guanidine or methylated guanidinesproduced in the organism are prevented from accumulating. Theresulting accumulation of these compounds, possessing as they doa marked action on muscular tissue, was regarded as the chief directcause of the tetany which follows the removal of the parathyroids.After its publication, Paton’s theory was somewhat generallyaccepted, but it is now being rather vigorously attacked.Perhapsthe most serious objections are those raised by G r e e n ~ a l d , ~ ~ whochallenges the main statements on which the theory was based,namely, that increased amounts of guanidine and its methylderivatives are found in the tissues and urine in parathyroid orideopathic tetany. Greenwald points out that the methods ofestimation of these bases employed by Paton’s colleagues, Burnsand Sharpe, are almost valueless, and that he could not himselfobtain any satisfactory evidence that guanidines are present inabnormal amounts after parathyroidectomy .His own conclusionsare that the only definite metabolic changes associated with para-thyroid tetany are the recognised low calcium content of the plasmaor serum and the diminished excretion of phosphates in the urine.This view is supported by other observations on the relation ofcalcium, and also phosphate, concentration of the blood to tetany .Underhill, Gross, and C ~ h e n , ~ ~ as well as Salvesen, Hastings, andMcIntosh,l have shown that the administration of large doses ofphosphates to dogs induced both tetany resembling parathyroidtetany and the associated fall in the calcium of the serum.The disappearance of the tetany on administration of calciumsalts has always been difficult to explain by the guanidine theory8 7 Ann.Reports, 1917, 1918.s 8 J . Biol. Chem., 1924, 59, 329; A., i, 794.90 J . Metabol. Res., 1923, 3, 679; A., i, 1255.J . Biol. Chem., 1924, 60, 311; A., 1, 896.R202 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.of Paton, and the results of the recent experiments of Palladinand Griliches do not lessen that difficulty.Of considerable interest, in view of the relation between tetanyand rickets, is the observation made by Grant and Gates3 thatconsiderable hypertrophy of the parathyroid glands has beenobtained after 4 weeks’ daily radiation with ultra-violet light,whilst Luce found marked hyperplasia of these organs in animalsmaintained for some time on diets low in calcium.Disturbances of the calcium phosphate balance in the blood maybe readily brought about by injections of one or other component,but the experiments of J.B. S. Haldane, Wigglesworth, and Wood-row show that other factors may cause marked alterations. Thealkalosis of forced breathing causes a fall in inorganic phosphateof the blood accompanied by a diminished excretion by the urine,the reverse being true when acidosis is provoked by breathingcarbon dioxide or by ingesting ammonium chloride.These resultsshould, however, be considered together with those of Harrop andBenedict,g who found that during the active assimilation of carbon-hydrate there is a fall in inorganic phosphate in the blood and aparallel diminished excretion by way of the urine, as well as thoseof Wigglesworth, Woodrow, Smith, and Winter demonstratinga similar fall after the administration of insulin. Rememberingthe hypoglyczmia of parathyroid tetany, the conclusion is justifiedthat the reduction in the phosphates of the blood in these casesis associated with the utilisation of carbohydrate in the tissue-cells.Phosphates in Carbohydrate Metabolism.The detection of phosphoric esters of hexoses in blood by Kayand Robison and their isolation in a crude state by Goodwin andRobison have considerably strengthened the position of Embdenand his collaborators, who €or a number of years past have tendedto identify the precursor “ lactacidogen ’’ of lactic acid formedduring carbohydrate metabolism in muscle with a compound ofthis type.It will be remembered that Foster and Moyle * showed3 years ago that muscle-tissue possessed the power both to synthesiseand hydrolyse “ hexosephosphate.” Kay and Robison now findthat this tissue will only hydrolyse the hexosediphosphoric ester,Biochem. Z., 1924, 146, 458; A., i, 598.J . Gen. Physiol., 1924, 6, 635.J . Path. Bact., 1923, 26, 200.Proc.Roy. Soc., 1924, [B], 96, 1 ; A., i, 451.J. Biol. Chem., 1924, 59, 683; A., i, 785.J . Physiol., 1923, 57, 447.* Biochem. J., 1921, 15, 672; A., 1921, i, 398.Ibid, 1924, 18, 755, 1139, 1161; A., i, 904, 1365, 1368BIOCHEMISTRY. 203the hexosemonophosphoric ester which is so readily hydrolysedby the bone enzyme being unattacked by muscle. Although theexperiments are not yet regarded as conclusive, they certainlysuggest that there is a hexosediphosphate in the blood ; a conclusionwhich is of interest when one recalls that Emden has long regardedhis “ lactacidogen ” as a hexosediphosphate or a closely-relatedcompound.Audova and Wagner lo have reported that following the adminis-tration of insulin there is an increase in the “lactacidogen” inthe muscles of rabbits, and that the increase is sufficient to accountfor the dextrose which has left the blood.The importance of thisobservation is considerable when the uncertainty which still pre-vails as to the fate of the dextrose that leaves the blood under theaction of insulin is borne in mind. Kay and Robison9 also havestudied this matter, and supply confirmation, in so far as theyshow that the administration of insulin leads to synthesis of organicphosphoric esters. This synthesis occurs in the corpuscles at theexpense of the inorganic phosphate originally present plus additionalphosphate drawn from the tissues.The nature of these organic phosphates has not been definitelyestablished, but it is believed that sugar or a sugar derivative ispresent in their molecule.On the assumption that 1 mol. of dextrosecombines with 1 mol. of phosphorus, the esterification as measuredby the loss of inorganic phosphate would account for approximately40% of the sugar which simultaneously leaves the blood. An im-portant feature of Kay and Robison’s experiments is that allowancewas made for the changes in blood volume which may follow insulinadministration.11The figure of 40% put forward by Kay and Robison is morereasonable than the suggestion of Audova and Wagner that form-ation of “ lactacidogen ” accounts for all the sugar lost, for evidenceis accumulating that some of the sugar is oxidised. Thus, in humansubjects studied by Perlzweig, Latham, and Keefer l2 the adminis-tration of insulin brought about the typical fall in inorganic phos-phates in blood and urine and a rise in the respiratory quotient,the latter indicating, in their opinion, increased breakdown of carbo-hydrate, although Dickson, Eadie, Macleod, and Pember l3 areuncertain how far this rise in the respiratory quotient can be thusinterpreted.An enzyme which can hydrolyse hexosediphosphoric esters islo Klin.Woch., 1924, 3, No. 6 ; Compt. rend. SOC. B i d , 1924, 90, 308.l1 Haldane, Kay, and Smith, J. Physiol., 1924, 59, 193.l2 Proc. Soc. Exp. B i d Med., 1923, 21, 33.lS Quart. J. Exp. Physiol., 1924, 14, 123.Ii* 204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.present not only in muscle-tissue,14 but also in the corpuscles andplasma of bl00d.l~ Indeed, the work of Forrai and of Y.Takahashi16suggests that similar catalysts have a rather wide distribution inthe body. That efficient mechanisms exist in the animal bodyfor converting sugars into phosphoric esters can no longer be doubted.Lawaczeck l7 has studied the dynamics of the phosphates in theblood, but his results are chiefly of importance in stressing the reversi-bility of the change from inorganic to organic phosphates. Thatthe rGEe of phosphates is an important one in the metabolism oforganisms other than the higher animals is, of course, known fromthe classic work -of Harden and Young on alcoholic fermentation.Additional evidence from other quarters is, however, accumulating.I. S. Maclean and D. Hoffert,ls in a study of the carbohydrate andfat metabolism of yeast, present evidence that a hexosephosphatemay be the first stage in the conversion of carbohydrate into fat.From the work of C.J. Lyon,lg who records the stimulant actionof phosphates on the respiration of the green plant Elodea cunadensis,and that of M. H. van Laer and R. Duvinage,20 who think thatsoluble phosphorus compounds play a part in the transport of food-stuffs in the germinating seed, it is easy to imagine that, before long,to phosphoric esters of sugars will be ascribed as important a partin the metabolism of the higher plants as the rGZe now allocated tothem in animal physiology.Insulin,A mass of literature dealing with insulin has accumulated duringthe past year, but a review of it does not provide much materialfor this Report.Many of the papers deal with the preparationof the active principle, and numerous new methods or modificationshave been proposed. One of considerable value on account of itsrelative cheapness is that described by Dodds and Dickens.*lIn this method, the macerated pancreas is extracted with aqueousformic acid, and the extract precipitated with picric acid. " Insulinpicrate " is extracted from the precipitate by acetone and is treatedby Dudley's method.22 Extraction of the pancreas with sodium14 Kay and Robison, Biochem. J., 1924, 18, 1139; A., i, 1368.15 Martland, Hansman, and Robison, ibid., 1152; A., i, 1381.16 Biochem. Z., 1924, 144, 149; 145, 48, 54; A., i, 456, 594; ibid., 145,1 7 lbid., 1924, 145, 351; A., i, 680.18 Biochem. J ., 1923, 17, 720; A., i, 352.1 9 J . Gen. Physiol., 1924, 6, 299; A , i, 476.20 Bull. Soc. chim. BeZg., 1923, 32, 355; A., i, 250.2 1 Lancet, 1924, i, 330.22 Biochem. J., 1923, 17, 376; A., i, 967.178; 146, 161; A., i, 589, 802BIOCHEMISTRY. 205bicarbonate may increase the yield of insulin nearly fivefold.23DudleyZ4 as well as Vincent, Dodds, and Dickens25 have foundthat very high yields of insulin may be prepared from the islet tissueof certain fish, e.g., the cod, in which this tissue lies separate fromthe glandular organ. This, of course, supports the current opinionthat the active principle is secreted by the islet cells. We stillremain ignorant of the chemical nature of insulin, in spite of theelementary analysis and molecular formula offered us by a t leastone enthusiastic worker.26 The majority of the evidence that hasbeen collected since last year’s Report was written supports Dudley’soriginal view that insulin is either a protein derivative (proteose)or an active substance intimately associated with such a compound.Biological Degrudation of Dextrose.The production of lactic acid as an intermediate product in thebreakdown of carbohydrates in muscle is now generally recognised,and we have seen that Embden’s view, that its immedirte precursor,“ lactocidogen,” is a hexosediphosphate, has been considerablystrengthened by recent studies of the phosphoric esters of the sugars.The intermediate formation of such a compound has always suggestedthat the combination with phosphoric acid in some way “ activates ”the sugar molecule, rendering it more readily degraded. ThusWarburg and Yabusoe2’ have recently found that lamdose, butnot dextrose, is oxidised in the presence of phosphates by atmo-spheric oxygen. The action of the phosphates is specific and cannotbe replaced by other salts. The theory advanced by Winter andSmith 28 2 years zgo, according to which the normal mixture of a-and p-dextrose is converted into the more reactive y- or ethylene-oxide form before it is broken down by the body-cells, would appearto have been generally rejected ; several other investigators havingbeen unable to confirm their work.29% 30, 31 Alternatively, we havethe suggestions by Laquer and Griebe132 that a-glucose, or byThannhauser and Jenke 33 that p-glucose, is the form actually brokendown.I n both cases, the evidence is obviously insufficient tojustify the view put forward. Much more valuable data are23 Dudley and Starling, Biochem. J., 1924, 18, 147; A., i, 585.24 Ibid., p. 665; A . 897.26 Lancet, 1924, ii.26 Cruto, Atti 22. Accad. Lincei, 1924, [v], 33, ii, 42; A., i, 1271. ‘’ Biochem. Z., 1924, 146, 380; A., i, 713.28 Ann. Report, 1922, 195.2s H u e and Denis, J. Biol. Chem., 1924, 59, 457; A., i, 784.30 Denis and Hume, &id., 1924, 60, 603; A., i, 1252.31 Tallerman, Biochem. J., 1924, 18, 583; A., i, 897.32 2. phy8iOl. Chem., 1924, 138, 148; A., i, 1128.33 Munch. med. Woch., 1924, 71, 196; A., i, 897206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.advanced in an extensive study of the efficiency of the various sugarsand thkir derivatives in relieving symptoms caused by insulin inmice described by Herring, Irvine, and M a ~ l e o d .~ ~ Complete posi-tive results were obtained with dextrose and mannose, also withmaltose, but in this case the action was not so prompt. Theseresults with the chief sugars provide confirmation of the resultsobtained previously by Noble and M a ~ l e o d . ~ ~ The case of maltoseis curious, and it is impossible to say whether hydrolysis to glucosemust precede its physiological action. The authors note theinteresting fact that both dextrose and mannose are readily fer-mented by yeast and are also characterised by being the mostpowerful restoratives of insulin hypoglyczmia.How far this isassociated with their ability to form phosphoric esters cannot yetbe said. The case of laevulose, however, shows some irregularities,for it is decidedly inferior to dextrose in diminishing hypoglycaemia,but is readily fermented. Among tetramethyl glucose, trimethylglucose, and tetra-acetyl fructose, only the last one showed anysigns of activity. Sucrose, a- and P-methylglucoside, tetramethylp-methylglucoside, tetramethyl y-methylglucoside, mannitol,dulcitol, and p-glucosan were all inactive. Salicin gave indicationsof exercising a slight action, but the experiments were vitiated byits deleterious effect. It is possible that its effect is due tohydrolysis.Reviewing these and other results, Irvine notes thatthe presence of the reducing group is necessary for activity to beshown. Furthermore, since arabinose shows no activity, it pointsto the sugars functioning as cyclic structures rather than as alde-hydes. We may quote the paragraph : " A review of the combinedresults shows no exception, which cannot be adequately explained,to the generalisation expressed in the statement that the type ofcarbohydrate molecule functional in eliminating the convulsionsymptoms occasioned by the administration of insulin isr-G---I 7 i (p I --X.Y.C---(+(+-,OH I!I kwhere either X or Y represents a reducing group." Lastly, theabsence of action on the part of glucose monoacetone, a readilyhydrolysed derivative of 7-glucose, should finally dispel the 7-glucosetheory of Winter and Smith.The curious observation has been recorded by Bodansky and byDucheneau 36 that the effect of insulin is more profound and pro-34 Biochem.J., 1924, 18, 1023; A., i, 1387.35 Amer. J . Physiol., 1923, 64, 547.36 Proc. SOC. Exp. Biol. Med., 1923, 21, 46BIOClIEMISTRY. 207longed in animals from which the thyroid gland has been extirpated.This has been confirmed by Burn and Marks,37 who studied theeffect of insulin on the same animals before and after removal ofthe gland. It must be remembered that this operation usuallyinvolves removal of the parathyroid glands as well, so that thepossibility must be considered whether the effect may not be due,wholly or in part, to the loss of the smaller glands which, as we haveseen, may possibly be concerned in carbohydrate breakdown.The r61e of lactic acid in muscular exercise has been the subjectof sc valuable series of papers by Hill, Long, and L ~ p t o n .~ ~ Theyare too long for detailed notice here and should be read in theoriginal. One outstanding point may, however, be referred to,namely, their observations, in collaboration with F ~ r u s a w a , ~ ~ thatthe respiratory quotient of the total excess metabolism caused byshort-lived muscular effort appears to be unity. This is in agree-ment with Meyerhof’s 40 view that the recovery process in isolatedmuscle has a. respiratory quotient of unity. It suggests that aftera short period of muscular work the recovery process involves theoxidation simply of lactic acid or carbohydrate.In relation to this problem is the paper by Foster and W O O ~ ~ O W , ~ who confirm and extend some earlier and interrupted work of Win-field and Hopkins 42 which demonstrated that pancreatic prepar-ations can inhibit the formation of lactic acid in chopped muscle.As the inhibitive substance was found not to be insulin, it wasobvious that the authors should recall Dakin and Dudley’s anti-glyoxalase, but they think the evidence tends to show that itsidentity does not lie there.Nevertheless the idea that lactic acidarises from methylglyoxal is decidedly attractive and further workshould be done. Eadie Macleod and Noble 43 report that, whereasinsulin had no action on glycolysis in defibrinated blood, it markedlyretarded it in mixtures of blood, muscle juice, and phosphates.Further work would appear to be necessary to clear up the relationof these findings.Reference was made last year to certain evidence in support ofEmbden’s 44 view that acetaldehyde is an intermediate product inthe oxidation of lactic acid to carbon dioxide and water.Simonand Piaux45 have now shown that lactic esters are oxidised spon-37 J . Physiol., 1924, 59, viii.38 Proc. Roy. Soc., 1924, [ B ] , 96, 438; 97, 84; A., i, 1128, 1362.39 Ibid., 1924, [B], 97, 155.40 Pfiug. Arch., 1919, 175, 88.41 Biochem. J . , 1924, 18, 562.43 Amer. J . Physiol., 1923, 65, 462; A., i , 113.44 Biochem. Z., 1912, 45, 186; 1913, 55, 335.4 b Bull. SOC. Chim.biol., 1924, 6, 412; A., i, 1034.4 2 J . Physiol., 1915, 50, v208 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.taneously with the formation of pyruvates, acetaldehyde, andcarbon dioxide. Alanine, which stands in close biological relationto lactic acid, yields the same products if oxidation occurs in analkaline medium a t the surface of a catalyst such as finely-dividedcopper. G. B. Ray46 also obtained acetaldehyde as an oxidationproduct of sodium lactate by hydrogen peroxide. Neuberg andG;ottschalk47 also have studied this problem, and by trapping theacetaldehyde as it is formed by means of calcium bisul~hite havefound that it is produced from glycogen in guinea-pig liver pulp,and that the amount is increased by addition of sugars and certainrelated substances.In this respect, the mono- and di-hexosephos-phates were more active than dextrose or laxulose. Pyruvic acidalso gave rise to acetaldehyde when added to rabbit liver pulp.These investigators observed that the addition of insulin increasedthe production of acetaldehyde considerably.I n this connexion, Toenniessen4* claims to have shown that asubstance present in pancreas, presumably insulin, is necessaryfor the production of acetaldehyde from lactic acid by choppedmuscle. Indeed, this writer would maintain that insulin acts onlactic acid rather than directly on carbohydrates. I n support ofthis view, he argues that all stages in the breakdown of carbo-hydrates previous to the appearance of lactic acid proceed normallyin the absence of the pancreas, but it is questionable whether he isjustified in advancing this view.For example, the very carefulexperiments of Himwich, Loebel, and Barr49 have shown that,following short periods of vigorous exercise in the moderatelysevere diabetic, there is a considerable formation of lactic acidwithout appearance of the acetone substances. Although thesepatients were not fully diabetic, and therefore were capable ofutilising some carbohydrate, the results gave no hint that thediabetic organism is unable to produce lactic acid from carbohydrateor to dispose of it after it is formed.Glycolysis in Cancerous Tissues.A number of papers have recently appeared from the laboratoryof 0. Warburg which report matter possibly of fundamental impor-tance.The method devised for this work is one which will be ofgreat value in studying the respiration and glycolysis in tissues.50Working with this technique, Minami 51 has found that the respir-48 J . Ben. Physiol., 1924, 6, 509, 525; A., i, 829.4 7 Riochem. Z . , 1924, 146, 164, 185, 582; A., i, 785, 920.48 2. physiol. Chem., 1924, 133, 158; A., i, 446.4@ J . Biol. Chem., 1924, 59, 265; A . , i, 786.50 Biochem. Z . , 1923, 142, 317.51 Ibid., p. 334BIOCHEMISTRY. 209ation activity of cancer tissue is of the same order as that of an equalweight of normal tissue, but that the glycolytic activity of theformer, as measured by lactic acid production, is many times thatof the latter. These results have been confirmed by Wate~-man,~~who also attempted to induce normal tissues to exhibit the higherglycolytic activity of the cancer cells.Addition of phosphates waswithout effect, whilst addition of hexosephosphate gave inconclusiveresults. The addition of an extract of cancer tissue to the mediumin which the normal tissues were kept did, however, cause anincreased formation of lactic acid. Warburg 53 has shown thatwhereas the lactic acid produced by normal tissues under anaerobicconditions is to a large extent oxidised when oxygen is admitted,that produced by cancer cells is only to a small extent soremoved. This is illustrated by the figures given by him toexpress the relations between aerobic glycolysis and respirationin tissues; thus, in cancer tissues it is 3-4, in normal tissues 1, andin benign tumours about 1.The most important part of his workis his observation that, if the oxidation processes in embryonictissues be depressed by small amounts of hydrocyanic acid or byprolonged exposure to nitrogen, the tissues, when placed underaerobic conditions, give values for this relation of the same orderas those given by malignant tumours. He advances very ten-tatively the idea that cancer may arise as a result of a chronicoxygen-starvation, leading certain cells to show the abnormalmetabolism. But there is as yet insufficient evidence to acceptthis view, attractive as it may appear It seems probable,however, that his work will lead to establishing a relation betweenthe rate of growth and the carbohydrate metabolism of tissues.The R61e of Iron in Biological Oxidations.Considerable interest still centres round auto-oxidisable cellconstituents containing sulphur in a sulphydryl grouping.Mathewsand Walker 54 first drew attention to the great acceleration of theautoxidation of cysteine that is brought about by the presence oftraces of iron. Later, Warburg and Sakuma 55 claimed, on thebasis of studies of the depression of this process by cyanides, tohave shown that the autoxidation is in reality a catalysis by ironwith an intermediate iron-cysteine compound playing an essentialpart. This view is supported by experiments in which thereaction was carried out in quartz apparatus with special precau-52 Arch. Neerland. Physiol., 1924, 9, 573; A., i, 1374.63 Naturwiss., 1924, 50, 1131.64 J .Biol. Chem., 1909, 6, 289; A., 1909, i, 289.6 6 Pflug. Arch., 1923, 200, 203; A., i, 138210 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tions to eliminate traces of ’chat metal. Under these conditions,thelrate of formation of cystine from cysteine was found to be veryslow indeed. Abderhalden and Wertheimer, 56 whilst admittingthe catalytic effect of traces of iron, do not agree with Warburgthat it plays an essential r6Ze. They have confirmed Mauthner’s 57observation that cyanides may reduce cystine, and attribute theinhibitive efTect of these compounds on the oxidation of cysteineto the reduction preventing the formation of an autocatalyticcyst eine- cystine complex.Harrison 58 has now provided evidence from Hopkins’s laboratorythat , during oxidation, cysteine and reduced glutathione behave ina similar manner.The results of these experiments, carried out inquartz apparatus and with great care to exclude, as far as possible,traces of iron, support Warburg’s view that depression of oxida-tion by cyanides is due to the formation of a non-catalytic ironcompound with cyanogen. Meyerhof , it will be recalled, believedthat inhibition of the catalytic action of copper on the oxidation ofthioglycollic acid is due to the formation of a copper-cyanogencomplex.6° The amount of metal that will function is extremelysmall. Mathews and Walker found that the reaction velocity ofthe autoxidation of cysteine was doubled by the addition ofM/105-ferric chloride, whereas Harrison has found that mg.ofiron caused a marked increase in the oxidation of glutathione.has also noted the catalytic effect of blood pigmentsand certain derivatives in that she found lizemoglobin, methzemo-globin, and haemin to exert a catalytic action on tlhe autoxidationof linseed oil. The iron-free hematoporphyrin was inactive, sothat catalytic action of the other substances is ascribed to the ironpresent in the molecule. In equal concentrations, the iron presentas blood pigment is more effective than in the form of an inorganicsalt. Curiously, she found that cyanides a t a concentration equiv-alent to the iron present did not depress the rate of oxidation, and itis a t present not clear how the results stand in relation t o thosedescribed above.Warburg’s 62 views on the r8Ze of iron in oxidations have led himvigorously to attack the well-known dehydrogenation theories ofoxidation advanced by Wieland.I n place of the latter’s view thatorganic oxidations proceed in two phases-first, hydration, followedRobinson56 Biochem. Z., 1923, 142, 68; 198, 122; 198, 415; A , , 1924, i, 12, 11.57 2. phyeiol. Chern., 1912, 7$, 32.58 Biochem. J., 1924, 18, 1009.6O PfEug. Arch., 1923, 200, 1.61 Biochem. J., 1924, 18, 255.62 Biochem. Z., 1923, 142, 518; A,, i, 242BIOCHEMISTRY. 21 1by loss of hydrogen by interaction with molecular oxygen-Warburg holds that molecular oxygen must first be activated bycontact or combination with a catalyst (iron or other substance).Certainly the inhibition of oxidations by cyanides appears to bemore readily explained by Warburg’s views, since combination ofoxygen with the catalyst and its “ activation ” are prevented.HGt!?noglobin.Apart from the experimental work which shows that haemoglobinand related pigments containing iron can catalyse certain types ofoxidation reactions, a considerable a mount of important work hasbeen reported during the last year or two on other functions of theblood pigment. We may first refer to the long-debated questionwhether hzmoglobin can act directly as a transporter of carbondioxide in the blood.It will be recalled that both L. J. Hendersonand Hasselbach demonstrated that values for the hydrogen-ionconcentration of the blood can be calculated from the equationcH = E .pw2/vcoo, which show good agreement with the observedvalues. On these grounds they concluded that the combined carbondioxide of the blood is carried entirely in the form of bicarbonatein ordinary circumstances. On the other hand, other authoritiesbelieved that hzmoglobin could enter into combination, eitherphysical 63 or chemical,64 with carbon dioxide and thus effect itstransport. A recent critical re-examination of the Menderson-Hasselbach equation 65 in its relation to blood has, however, shownthat their view is best in agreement with facts. Positive proofthat in ordinary circumstances hzemoglobin exists in the corpuscleas the sodium or potassium salt has been forthcoming, forTaylor 66 has made a study of the potential difference between bloodor laked corpuscles and salt solution and finds that in all casesthe sign of the potential difference indicates that the haemoglobinis present as an anion.It is, therefore, impossible for hzemoglobinto combine chemically with carbon dioxide until the reaction isbrought to the acid side of the isoelectric point of the protein,which is given as pH 6%-6.7.67p G8 Such was actually the case in theexperiments of Zuntz in 1883, and in those of Buckmaster in whichhigh pressures of carbon dioxide were employed, but this would not63 Bayliss, J . PhysioE., 1919, 53, 162.13* Buckmaster, ibid., 1917, 51, 105, 164.6 5 Warburg, Biochem. J., 1922, 16, 153.6 6 Proc. Roy. SOC., 1924, 96, [B], 383.6 7 Osato, Biochern.Z., 1922,132, 485.6 8 Hastings, Van Slyke, Neill, Heidelberger, and Harington, J . Biol.Chem., 1924, 60, 89; A., i, 1008212 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.occur under physiological conditions. It can be seen from this workthat sodium or potassium hzemoglobinate must act in the body asa very efficient “ buffer,” and that base is lost to carbon dioxide withthe formation of the free acid :NaHb + H,CQ, = NaHCO, + HHb.The acid nature of hzemoglobin has attracted wide attention. Thedemonstration that oxygenated blood is more acid than reducedblood has not been easy because of the difficulty of measuring thesmall changes concerned. Actual measurements have heen made,such as those of Parsons,69 and although the differences are smallthey are definite.A. V. Mill has, however, pointed out that theknown effect of acid on the dissociation curve of blood makes itthermodynamically inevitable that oxygenation will raise thehydrogen-ion concentration. Further, the effect of carbon dioxideon the dissociation curve, which Barcroft and Murray have shownis due to change of cE, makes it certain that there will be a corre-sponding effect on the combination of carbon dioxide. It followsthat the effect of oxygenation on carbon dioxide combination mustbe due to the liberation of a fixed acid about as strong as carbonicacid. What must be regarded as conclusive proofs of this are givenin Hill’s paper. The same occurs when hzmoglobin combines withcarbon monoxide. 71 Hastings, Van Slylte, Neill, Heidelberger, andHarington 72 have directly determined the base-binding power ofoxy- and reduced hzmo-globin over the pB range 6.8-7.6.Theincrease in base-binding power caused by oxygenation of hzemoglobinhas a maximum value of about 0.7 equivalent of base per atom ofiron in the pigment, and follows a curve consistent with Hender-son’s 73 hypothesis that combination with a molecule of oxygenincreases the dissociation consta’nt of one labile carboxyl group inthe hzmoglobin molecule. It does not follow the equation requiredby Hill’s hyp~thesis,~* according to which only one hydrogen atomin an aggregate of n molecules, where n is the index in Hill’s oxygendissociation equation, has its dissociation constant affected byoxygenation or reduction.H(Hb), + nO2 H(HbO2)nWHbO,),‘ =e= H + (HbO,),Brown and Hill believe the value of n to be about 2.2.Beforeleaving this side of the hBmoglobin question attention should bee9 J . Physiol., 1917, 51, 440.7l Hastings, Sendroy, Murray, and Heidelberger, J . Biol. Chem., 1924,70 Biochem. J., 1923, 17, 544.61, 311 ; A., i, 1251.Ibid., 1924, 60, 89; A., i, 1008. 73 A., 1920, i, 403.74 PTOC. Roy. SOC., 1923, [B], 94, 297; A., 1923, i, 398BIOCHEMISTRY. 213directed to an important paper by Henderson, Bock, Field, andStoddart 75 on blood as a physicochemical system. All the knownphenomena of the respiratory cycle have been described with agood approach to accuracy with the following seven variables:free oxygen, total oxygen, free carbon dioxide, total carbon dioxide,pE of serum, volume of corpuscles, and the ration of the concentra-tions of anions within and without the corpuscles.This papermerits very careful study.We may now turn to some very important researches fromBarcroft’s laboratory. It has long been know11 on the basis ofevidence-chemical, physiological, and serological-that thehzmoglobins of different species are different substances. Mo’stinteresting results have followed the efforts of Anson, Barcroft,Mirsky, and Oinuma 76 to correlate the spectra of various hzemo-globins with their relative affinities for oxygen. If the positionof maximum intensity of the a-oxyhemoglobin band, measured inAngstrom units, be for any one species A , and that of the corre-sponding carbon monoxide compound be B, then the shift of theband caused by conversion of the oxyhzmoglobin into carboxy-hzermoglobin is A--By which is termed the “ span.”Now if the “ span ” be plotted against log K , wherecne obtains practically a straight line, and the relationship may beexpressed as log II: = 0*05(A-B).This means that the displace-ment of the band corresponds with a proportional change in thefree energy of the reaction.If, now, the relationship between the absolute position of thea-band and the absolute value of the equilibrium constant Kbe studied, then log K is found to alter by 0.055 for every Angstromunit. Further, if the shift of the band towards the violet thatoccurs with a fall of temperature be observed, it is found that thealteration in the affinity for oxygen, as measured by the reciprocalof the concentration of oxygen present when half the liaemoglobinis oxidised and half reduced, can be represented by log 1/CsOx =0.049 for 1 Angstrom unit.These three values, showing so closean agreement, obviously represent more than a haphazard coinci-dence, and indicate that we may be on the point of discovering somefundamental energy relationships of the hEmoglobins.Incidentally, it may be stated that Barcroft and his colleagueshave reasons for believing that the differences are in no small part,75 J. BioZ. Cltem., 1024, 59, 379; A., i, 780.76 Proc. Roy. Soc., 1924, [Bl, 97, 61; A., i, 1363214 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.or perhaps entirely, due to the protein moiety, globin.If so, thenature of the protein bound with the hsmatin would appear pro-foundly to affect the gas-binding powers of the pigment. Theconception that the specific characteristics of haemoglobins arebound up with the protein rather than with the pigment nucleushas been advocated for some time by V l ~ k , ~ ~ and this recent workwould appear strongly to support his view. Furthermore, such aview is more in keeping with our knowledge of the chemistry ofhsmoglobin and of the proteins generally. Further work in thisfield will be awaited with grmt interest.Proteins and Amino-acids.No outsbailding work has marked the past year's researches inthe field of protein chemistry, but steady, if slow, progress may berecorded.The preparation of substituted proteins by such processes asbromination, methylation or benzoylation 78 may possibly be ofvalue in throwing light on internal structure, but the results so farachieved do not appear very encouraging. The methylated productsare more resistant to attack by erepsin than the parent proteins, andImai 79 suggests this may be due to the inhibitive effect of methylgroups near the peptide linking.Experiment on the betaines of glycylglycine, diglycylglycine, andtriglycylglycine are described in support of this idea, the first twobeing unattacked, whilst the last, in which the methyl groups asefurthest removed from a peptide linking, is hydrolysed to a slightextent. Similar experiments were made with benzoyl derivatives,but their value is limited by tjhe fact that it is uncertain whichpeptide linkings were broken.More valuable data are being obtained from a careful study of theintermediate products in the hydrolysis of proteins.I n referring to the hydrolysis of proteins, passing reference maybe made to the statements of Clifford that a catalyst is present inmuscle (cod) which can accelerate the hydrolysis of protein a ttemperatures of 95-100".Apparently control of the reaction of themedium was not maintained in her experiments, and further dataare obviously called for. It has been known for many years thatprolonged digestion of proteins, particularly caseinogen, with trypsinfails to give complete hydrolysis. Luck 8o has now observed thatthe undigested residue totally resists attack by trypsin and that,77 Arch.Phys. biol., 1922, ii, 22.i 8 Vandevelde, Rec. trav. chiin., 1924, 43, 158; A., i, 678.7s Imai, 2. physiol. Chem., 1924, 136, 173, 188, 192, 205; A., i, 920, 921.* O Biochenz. J . , 1924, 18, 669, 679; A., i, 904, 891BIOCHEMISTRY. 215after acid hydrolysis, it consists almost entirely of lysine andglutamic acid. About 10% of the total nitrogen can be liberatedas iimmoiiia, and since there is evidence that this is not associatedwith the lysine, it is concluded that the product is probably aglutsmine-containing peptide. Whether glutamine or this com-plex is present in the caseinogen molecule, or whether it is a secondaryproduct arising by enzymic synthesis, is not yet clear.Frankel,Gallia, Liebster, and Rosen 81 have isolated a number of substancesfrom caseinogen after digestion with trypsin for two months. Anumber of the products, such as &tryptophan and d-leucine anhy-drides, are regarded as arising by secondary reactions. Leaven-worth,sZ having studied the basic amino-acids of casein, draws theconclusion that it is improbable that this protein contains anyhitherto unidentified member of that group.Abderhalden 83 and his colleagues continue to carry out long andcareful examinations of the products isolated from the partialhydrolysis of proteins. A iitimber of anhydrides of amino-acidshave been isolated and identified. He believes that the proteinmolecule may contain anhydride-like residues having the diketo-piperazine structure as well as the recognised peptide chains.The general method employed to isolate these products of partialhydrolysis has been fully described.The suggestion of anhydride groupings has arisen also in a, newdirection from the work of Brill,84 who has studied the investigationof physical structure of silk-fibroin by X-ray methods.He concludesthat this product is a mixture of two proteins, of which one iscrystalline, and it is suggested that the molecule is composed ofalanine and glycine in equimolecular proportions, possibly unitedin a ring formed of four d-alanylglycine anhydride groupings com-bined as a polypeptide.I n the field of the amino-acids we welcome the valuable methodfor the preparation and determination of arginine which we owe toKossel and Gross.85 Arginine yields an almost insoluble salt with' ' naph thol-yellow- 8, ' acid,which is easily prepared, isolated, and estimated.Karrer 86 hasstudied the official configuration of the amino-acids, based ond-swine, and finds that d-alanine, Z-serine, Z-cystine, Z-asparagine,and Z-aspartic acid all have the same configuration. He suggests2 : 3 -dinit'ro - 1 -naphthol- 7-sulphonica1 Riochem. Z., 1924, 145, 225; A., i, 677.82 J . Biol. Chem., 1924, 61, 315; A., i, 1362.a* Z. phY8iOE. Chem., 1923,131, 284; 1924,136, 134; 139, 181 ; A., i, 227,R4 Rnnalen, 1923, 434, 202; 4., i, 102.e5 Sitzungsber. Heidelberg, AIcad. H'iss., 1923, [B], 1; A . , ii, 211.86 Helr. Chim.Acta, 1923, 6, 957; A., i, 151.890, 1361216 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.that all naturally occurring amino-acids belong to the samegroup.Abderhalden and Sickel 87 have described the isolation of anamino-acid from caseinogen which is regarded as the hydroxy-tryptophan described by Abderhalden and Kempe in 1907.88Little further information has been forthcoming regarding thestructure of the new amino-acid, C5H,,Q,NS, isolated by Mueller 892 years ago. Apparently the sulphur is present in a form whichis not liberated as hydrogen sulphide on treatment with alkalis.90After administration to man the sulphur is excreted in the urineas inorganic s ~ l p h a t e . ~ lRegarding the physiological significance of the individual amino-acids, we have two papers of interest.One is by SureYg2 claimingthat proline is an essential constituent of the diet for growth in rats,and that substitution of pyrrolidonecarboxylic acid €or this amino-acid was not of any value. describ-ing experiments on the relation of histidine and arginine to growth.It will be recalled that Ackroyd and Hopkins 94 found that eitherone of these two amino-acids must be present in the diet for growt'hto occur in young rats, but that they are interchangeable. Thechange was related by these authors to a general similarity of thestructure of the two molecules. Rose and Cox now give confirm-ation of the essential nature of histidine, but cannot agree thathistidine in the diet can be replaced by arginine.Progress in studyof the metabolism of amino-acids may be illustrated by one or twoselected papers. Further confirmation of the oxidation of amino-acids by atmospheric oxygen a t the surface of charcoal, originallynoted by Warburg,95 has been advanced by Wieland and Bergel.soGlycine, alanine, and phenylalanine yield carbon dioxide andammonia in equimolecular proportions, an addehyde with onecarbon atom less than the original substance, and a little of thecorresponding acid. Somewhat similar results were obtained byFicht,er and Kuhn97 in the oxidation of amino-acids by means ofThe other is by Rose ands 7 2. physiol. Chem., 1924, 138, 108; A., i, 869.8a A., 1907, i, 808.as Proc. SOC. Exp. Biol. Med., 1922, 19, 161.93 J . Biol. Chem., 1923, 55, Proc.xv; 56, 157.B1 Ibid., 1923, 58, 373; A., i, 438.92 Ibid., 1924, 59, 577; A., i, 787.93 Ibicl., 1924, 61, 747; A., i, 1370.9 1 Biochem. J . , 1916, 10, 551; A., 1917, i, 237.s5 Ann. Report, 1923, 193.9 6 Annalen,-1924, 439, 196; A., i, 1216.8 7 Hdv. Chirn. Acta, 1924, 7, 167; A., i, 379BIOCHEMISTRY. 217hydrogen peroxide. Probably both these studies have a closebearing on the mechanism of amino-acid breakdown in the livingcell, although the intermediate steps in both cases are not yetknown.For some time, chiefly as a result of Neuberg’s and of Dakin’sstudies, it has been accepted that deamination normally representsthe first stage in the breakdown of amino-acids in the organism.This may occur in one of three ways :(1) by oxidation, with formation of an cc-ketonic acid.(2) by reduction, with formation of a saturated acid, and(3) by hydrolysis, with formation of an cc-hydroxy-acid.Generally speaking, as Dakin has shown,98 the evidence favoursthe first process, with possibly a hydrated imino-acid or a glyoxalderivative a t the intermediate product.Fearon and Montgomery 99now deal with these theories rather critically in directing attentionto Werner’s view that there are difficulties in accepting the ideaof the production of ammonia from the oxidation of an amino-acid in neutral or, more particularly, in alkaline solution.These authors were abje to detect cyanic acid among the productsof oxidation of glycine and alanine by hydrogen peroxide, andsuggest that the reaction in neutral solution might be written :R-?H-?H3 + 0 + R-CHO + H,O + HNCO.CO-0Ammonia and carbon dioxide would then arise by hydrolysis of thecyanic acid, and urea would be formed from combination of the acidwith ammonia.It is true that these suggestions bring the mechanism of deamina-tion into line with Werner’s well-known views on cyanic acid andurea.1 Furthermore, they fit in reasonably well with the resultsof Wieland and Bergel reported above.Where difficulties arise isin reconciling a theory, in which deamination involves nitrogenleaving the molecule with an attached carbon atom, with muchthat has been accepted regarding the simple transformations thatappear to occur in living cells.How, for example, are we to view it in the light of the very simplechange studied by Dakin and Dudley,2 according to which thea-amino-acids are in equilibrium in solution with ammonia andthe a-ketonic aldehydes.R*C€I(NH,)*CO,H PE*CO*CHO + NH,.$* “ Oxidations and Reductions in the Animal Body,” London, 1922,m9 Biochem.J., 1924, 18, 576; A., i, 898.“ Chemistry of Urea,’’ London, 1923.* J. Biol. Chem., 1913, 14, 555; 15, 127218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It is doubtful whether Fearon and Montgomery have yet pro-duced sufficient evidence to disturb the views currently held, buttheir work is suggestive and stimulating.Uric Acid.Work in the field of purine metabolism has produced a t leastone outstanding paper during the last year, namely, that recordingan experimental study of the uric acid problem with reference toanimals and man, including gouty subjects, carried out by OttoFolin and his co-workers, Berglund and Derick. This publicationis one of more than one hundred pages a,nd well repays carefulreading.3About 20 years ago, vigorous discussioii centred round the yuaes-tion whether or not the human organism can break down uric acid.Burian and Schur’s classic work may be regarded as the centralpoint of the defence of those who believed that uric acid is oxidisedin human tissues, whereas Wiechowski was one of the chief opponentsof this view. The careful review of the literature which prefacesFolin’s paper makes it very clear bow misleading much af the earlierliterature has proved, and how difficult it has been to form anopinion of any value from that mass of conflicting evidence.The first experiments described were carried out on dogs, which,as was already known, possess the power to oxidise uric acid, inorder to learn the immediate distribution in the tissues of injecteduric acid. These experiments yielded striking results showing that,of the organs investigated, only the kidneys take up any appreciableamount of uric acid from the blood, and that they may absorbquantities which appear extraordinarily large. It is conceivable,of course, that the other tissues, particularly the liver, which isbelieved to contain uricase, might also absorb the acid, but thatextremely rapid oxidation might render this difficult to detect. Theauthors present reasonable evidence, however, that such is not thecase, and that tissues other than the kidney are actually imperme-able to uric acid during life.The second surprising feature of these experiments on dogs is thaturic acid is not destroyed appreciably in the kidneys, but that itvery rapidly disappears from the blood, presumably by oxidation.As much as 70% may be destroyed within the first 10 minutes afterinjection. This destruction ceases as soon as the blood is withdrawnfrom the circulation and cannot therefore be ascribed to the presenceof a uricolytic enzyme in the blood. Folin and his colleaguessuggest that an essential part may be played by some factor pouredinto the blood from some other tissue. As the concentxation of3 J. BioZ. Chern., 1924, 60, 361BIOCHEMISTRY. 2 19uric acid falls in the blood, the store in the kidney is slowly dis-charged. The speed of destruction is governed by the concentrationin the blood.Folin confirms the curious fact discovered by S. R. Benedictthat the Dalmatian hound shows, as compared with other speciesof dogs, much slower oxidation of uric acid, It may be of interestto note, in passing, that Onslow investigated the relation betweenuric acid excretion and allantoin excretion in hybrids of 'the Dalma-tian coach-hound and found that the excretions of the hybridsresemble those of the normal dog. The greater power of destroyinguric acid tends to be a dominant character. Returning to theexperiments of Folin, Berglund, and Derick, we fmd that somewhatsimilar results were obtained with goats, cats, rabbits, and birds,but the speed of destruction was usually very much slower thanin the dog.The experiments with men are perhaps the most important partof the paper, for they do provide us with the first clear-cut evidencethat uric acid is broken down in the human organism. Intravenousinjection of uric acid (20 mg. of lithium urate per kilo. of body-weight) results in a rapid and prolonged rise in the concentration ofuric acid in the blood. From the experiments on other species, andfrom the fact that the amount in the blood shows very little decreasein a short while after injection, it is concluded that the human organs,other than the kidney, are impermeable to uric acid. From 30-90%is excreted by the kidney, but evidence is presented that from 10-70(average value 50) yo is destroyed. The high levels of uric acid inthe blood are regarded as indicating a lack of responsiveness on thepart of the human kidney. There appears t o be a greater responseif the uric acid is administered when the subject is on a high proteindietary, and it is suggested that this is the explanation of the factthat more endogenous uric acid is excreted on a diet rich in proteinthan on one deficient in that respect. Experiments with subjectsprone to gout lead Folin and his co-workers to believe that in thisdisorder the organism possesses normal powers of destroying uricacid, but that the responsiveness of the kidney to excretion is sub-normal and results in maintenance of high uric acid concentrationsin the blood.J. C. DRUAIMOND.H. J. PAGE.J . Lcib. Clin. Med., 1916, 2, 1. Riochem. J., 1923, 17, 334, 564

ISSN:0365-6217    

DOI:10.1039/AR9242100171

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

CRYSTALLOGRAPHY.THE science of crystallography, as soon as its devotees realisedthat in the method of X-rays they possessed a crucial test for itslong-neglected geometrical theory, came in one stride into its own.It has emerged triumphantly from this trial and now advanceswith that rapidity which is to be expected only from a sciencewhich applies a sound technique to the needs of a trustworthytheoretical treatment. We feel quite sure now of what we haveto look for in the inner structure of crystals, and this knowledge,supplemented by the mass of evidence known to the neighbouringsciences with which crystallography is fast becoming closely in-volved, will help us soon, there is no doubt, to play an all-importantpart in the quest of the nature of the atom.I n the last few yearsthe theory of space-groups has attained a highly satisfactoryposition. Through it crystallography has acquired the means ffurnishing first-rate information on dubious points of both chemistryand physics, for it is only from crystals that we can get a clearidea of what atoms and molecules will do when comparatively freefrom such powerful disturbing factors as prevail in the liquid andgaseous states. I n some ways this may appear a disadvantage, buton the whole the results will be highly acceptable. It is not easyto believe that in crystals the atomic configurations are verydifferent from what we should expect in " free " molecules-ncdoubt there are small differences, but they are so small as to detractonly a little from the value of the conclusions.Crystals are not" dead "; rather shall we say they are only " quietened down "somewhat.Last year, R. W. G. Wyckoff gave us a complete analyticalexpression of the theory of space groups-an invaluable workThis year,l the subject has been approached from a different pointof view, one which we venture to hope will prove intelligible andimmediately useful to physicists and chemists even of negligibletraining in mathematical crystallography. A simple principlehas been used t o deduce the abnormal spacings to be expectedfrom each of the 230 space-groups when examined by X-raysthus providing a complete list to which reference can be madewith great facility. Together with this table are given all thepossible molecular (and therefore ionic and atomic) symmetriesW.T. Astbury and K. Yardley, Phil. Trans., 1924, [ A ] , 224, 221; A.:ii, 720.22CRYSTALLOGRAPHY. 221for all possible cases, a list which, we trust, will appeal strongly tochemists. Finally, diagrams are given showing in the simplestpossible manner all the 230 ways in which molecules can unite toform the various types of crystal-structure. With the aid ofthese the crystal-a.nalyst can readily form a mental picture ofwhat sort of combination he is dealing with. To many-thisseems to be characteristic of the science of our own country-such an opportunity is always desirable.Metals, Alloys, etc.The study of the crystalline structure of metals, alloys andintermetallic compounds is at the same time one of the mostimportant and difficult branches of crystallography.Its materialusefulness is manifest, yet from the point of view of pure sciencealso the lessons to be drawn from the study of such substancesare full of significance for many of the baffling problems of atomicphysics. It is essential, before these problems can be attackedprofitably, that the data should be as well defined as possible,that crystalline structure should be known down to the individualatomic positions. When this knowledge has been gained for alarge number of metals and alloys, we shall have made an enormousadvance towards our goal.Unfortunately, our present knowledge of the inner structureof alloys can only be described as scanty. The problem isso full of pitfalls that it is useless to approach it with any butthe most carefully organised plans, prepared in collaborationby metallurgist, physicist, chemist, and crystallographer. Thetrouble so far is that this has not been done, that the investigationshave been carried out with insufficient knowledge of some aspector other of the problem.It cannot be too strongly urged that,if success is to be attained, the closest association must alwaysbe maintained between all branches of t,he subject.Of this year's work on alloys, probably the investigations whichmost satisfy these conditions are those of Westgren and hisassociates. At the May meeting of the Iron and Steel Institutewere described some results supplementary to their previouswork on the structure of iron and steel. A new photograph of ironat 1450" was decisive that the &phase has the same structure asthe or-phase, whilst Laue, rotation, and powder photographs ofcementite combine to show that the cell is orthorhombic, containsfour molecules of Fe,C, and has the dimensions 4.518, 5069, and6.736 B.U.Cementite has the Same structure as cohenite, theiron carbide occurring in meteorites. New photographs of austeniteshow that austenite increases in size with increase of carbon conten228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and that the carbon atoms do not replace the iron atoms, butare situated in the interstices of the face-centred cubic lattice. Onthe other hand, a recent investigation (by the ionisation-spectro-meter alone) of the structure of hard steel2 has furnished someevidence that in martensite we have carbon atoms replacing ironatoms, after the manner of what has been found to hold in manynon-carboniferous alloys such as copper-aluminium, where theindividual metals replace each other, atom for atom.For 0.80and 1.31y0 carbon steels, both in coarse and fine martensite con-dition, the same lines were found as in the spectrum of carbon-freeiron, but they were only one-third as intense, broader, and slightlyshifted. The author concludes that martensite is a mixture of(1) a solid solution of carbon in iron, the C-atoms replacing theFe-atoms, and (2) finely dispersed cementite, the former con-tributing to the hardness through distortion and the latter throughbeing so fine-grained.At the March meeting of the Institute of Metals, E.R. Jette,G. Phragmbn, and A. F. Westgren contributed a paper on thestructure of the copper-aluminium system. The same system wasinvestigated by Owen and Preston last year, but these more recentresults indicate that their work was incomplete, in the sense thatwith alloys the spectrometer method which they used is not capableof revealing the nature of the large number of planes which mustbe examined before we can be really sure that we have deter-mined the true cell and space-group. The work of Jette, Phrag-m&n, and Westgren, however, was carried out with all the resourcesof the various X-ray methods, and in consequence it appears tobe one of the most trustworthy investigations on alloys yet made.The photographs reveal a t once the existence of four differentphases, agreeing in the main with the equilibrium diagram ofCarpenter and Edwards : (1) a - 7% A1 gives displaced Cu lines ;12.5o,/, is a mixture of the a- and y’-phases : ( 2 ) y’ - 16-25%A1 gives pure 7’ : (3) 42% A1 gives a mixture of 7‘ and 6; pure6 a t 46% A1 : (4) 55, 80, and 95% A1 show 6 mixed with pure Al.With regard to the F-phase, CuAl,, Laue, rotation, and powderphotographs agree in assigning a body-centred tetragonal lattice,a = 6-05 and c = 4-88 A.U., of which the symmetry is D,, D4,C,, or D4n; four molecules of CUM, per cell. This differs fromthe simple st’ructure proposed by Owen and Preston, and mustsupersede it.Laue photographs of the ?’-phase showed cubic symmetry (Td,0, or Oh), the side of the cell being about 9 A.U.Exact measure-ments showed that, whereas Al increases the Cu-lattice in the2 K. Heindlhofer, Physical Rev., 1924, 24, 426; A., ii, 863CRYSTALLOGRAPHY, 223ix-phase, it actually decreases it from 5.701 (16%) to 5.656 (25o/b)in the ?’-phase. Furthermore, whilst the a-phase is a case ofsimple substitution with approximately four atoms per cell, itseems to require 52 to 49 atoms to fill the unit cell of the ?’-phase,corresponding to such f ormuh as CU&1,6, Cu33A118, Cu30A120,and CU,,~!~~,. The curve of changing density is in closest agree-ment with that obtained by supposing that three copper atomsare replaced by two aluminium atoms.This is a truly astonishingstate of affairs, and its full meaning is a t present quite beyondany conjecture. Curiously enough, no difference can be observedbetween the relative intensities of the lines in the powder photo-graphs of the 16% and 25y0 alloys. It is evident that a longand careful inquiry must yet be made into the structure of sucha phase before we. can feel on safe ground. The elucidation ofthis problem is of vital importance to the study o€ the natureof alloys. The photographs of the 95% alloy are practicallyidentical with that of pure aluminium. That of a quenched 12.5%aluminium alloy showed lines corresponding to a phase stable onlya t higher temperatures.Of other work on alloys we may mention an X-ray examinationof mixed crystals of tungsten and molybdenum (Soy0), and ofsilver and gold (25 and 75y0), which failed to support Tammann’stheory that in such mixed crystals the atoms are always locatedin certain definite places in the space-lattice; and an examinationof certain the results of which indicate, for tin, zinc,and cadmium amalgams, the appearance in each series of a secondtype of crystal as the percentage of mercury increases.It seemsprobable from the powder reflections that the new lattices arehexagonal and different from those possessed by tin, zinc, orcadmium a t the ordinary temperature. In the series of leadamalgams, it was found tlhat the presence of O-20~o of mercuryatoms contracts the face-centred lead cube by 0--0.08 B.U.Of the intermetallic compounds should he noticed Mg,Sn 5and Mg,Si,6 both of which have been found to possess the ‘‘ fluor-spar structure,” with cube sides 6.78 and 6.39 A.U., respectively.AlSbHassel and by the rotation method, have confirmedthe structure of bismuth previously found by other workers,8is like zinc blende, with side 6.126 A.U.,4.€3. van Arkel, Pi~ysico, 1924, 4, 33; A., ii, 618.C. v. Simson, 2. physikal. Chern., 1924, 109, 183; A., ii, 449.L. Pauling, J. Amer. Chern. Soc., 1923, 45, 2777; A., 1924, ii, 110.E. A. Owen and G. D. Preston, Proc. Physical SOC., 1924, 36, 341.0. Hassel and H. Mark, 2. Physik, 1924, 23, 269; A., ii, 382.A. Ogg, Phil. Mag., 1921, [viJ, 42, 163; R. W. James, ibid., p. 193;L. W. McKeehan, J . PranM. Imt., 1923, 195, 59224 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.while a similar structure has been found for arsenic Anexamination of “ single-crystal ” wires of tin 10 has confirmed thestructure arrived at last year by Mark and P616nyi.“Metallic ”selenium and tellurium l1 have been examined by the powdermethod, and a structure deduced which is similar to that of quartz,&.e., three-fold spirals in a trigonal-hexagonal lattice (rh). Forselenium and tellurium, respectively, the side of the basal triangleis 4.34 and 4.44B.U. and the ratio c/a 1.14 and 1.33.One of the most powerful methods of attacking the problem ofcrystal structure is the rotating-crystal method. For this method,crystals of volume less than a cubic millimetre are ample, andwith such crystals at one’s disposal the examination of metalsand alloys would be greatly facilitated. Unfortunately, the com-mon metals usually crystallise in aggregates of. very small crystals,thus excluding the use in most cases of any but the powder method,which is all too inadequate for trustworthy conclusions.Clearly,in ordinary metallic crystallisation the number of centres ofcrystallisation is so enormous that undercooling i s in generalimpossible. In recent years, several attempts have been made,with varying degrees of success, to overcome this dficulty andgrow large single crystals of metals. The products have, of course,provided invaluable aid to crystal analysts, but, furthermore, theyhave shown that the properties of single metallic crystals arequite d8erent from those of the usual aggregates of microscopiccrystals.For instance, zinc crystals have shown themselves tobe more plastic even than lead, a stress of only 35 g. per sq. mm.being sufficient to produce permanent deformation, whilst anelongation up to 500% can take place without rupture. Severalmethods of producing large single metallic crystals have beendevised, in which connexion we may mention the work of Tam-mann, Czockralski, Carpenter and Elam, Bridgeman and others.A rather elegant modification of Tammann’s method has justbeen described by Obreimov and Schubnikov.12 The metal ismelted in a glass tube drawn out to a capillary at the lower end.If the volume of this capillary end is sufficiently small, it willcontain a single metal crystal, and from this unique centrecrystallisation can be caused, by a careful extension of the coolingfrom the capillary upwards, to spread throughout the tube withoutthe appearance of other centres of crystallisation, that is, a single0 A.J. Bradley, Phil. Mag., 1924, [vi], 47, 657; A., ii, 382.10 A. E. van Arkel, Proc. K . Akad. Wetelzsch. Amsterdam, 1924, 27, 97.11 M. K. Slattery, Physical Rev., 1923, 21, 378; A., 1924, ii, 849; A. J.l2 I. Obreimov and L. Schubnikov, 2. Physik, 1924, %, 31; A., ii, 721.Bradley, Phil. Mag., 1924, [vi], 48, 477; A., ii, 817CRYSTALLOGRAPHY. 225metallic crystal of any desired shape (that of the vessel in whichthe melting takes place) can be grown. To avoid the formationof oxide, the tube must be evacuated; this also removes occludedgas.In this fashion, bismuth, tin, zinc, magnesium, and aluminiumwere all crystallised without much difficulty. For details regardingcertain points, reference should be made to the original paper.It is interesting to note that the maximum cross-section of thecapillary, for the formation of a monocrystalline block, varies withthe metal.It seems reasonable to expect that methods of crystallisationsimilar to the one just described would prove effective in the caseof non-metallic substances which resist the usual methods ofgrowing large crystals and yet can be melted without decom-position-such, for instance, are the higher paraffins and fattyacids. One hopes that the scope of this method will be success-fully extended to other than metallic systems.And while on thesubject of the growth of large crystals, it is convenient to mentionhere that cubes of rock-salt of side up to 3 cm. have been recentlygrown from brine containing 0.1% of sulphuric acid and 0.1%of lead nitrate,13 a striking example of the subtleties of a com-paratively little known branch of crystallography.As mentioned above, the metallic " single-crystals " have provedof great value to X-ray analysts. I n this connexion should beread a paper on the determination of the crystal-axes in suchcrystals,l* one on some of their properties,15 and two papers onthe properties and deformation of fine tungsten wires composed ofcrystals many of which occupy locally the complete volume ofthe wire.16The Structure of Aragonite, etc., and the Calculation ofRefractive Indices from Crystal-structure Data.The beginning of 1924 saw the appearance of a paper l7 byW.L. Bragg on the crystal-structure of aragonite, the ortho-rhombic form of calcium carbonate. It will be remembered thatthe rhombohedra1 form, calcite, was one of the earliest crystalsto be elucidated by the method of X-rays, and now, after thelapse of several years, the more difficult analysis of the less sym-metrical dimorph has, we believe, been successfully accomplished.The lattice is simple orthorhombic (I?,,), 4.94 x 7-94 x 5-72 A.U.,13 W. E. Gibbs and W. Clayton, Nclture, 1924, 113, 492; A., ii, 335.l4 A. Mliller, Pmc. Roy. Soc., 1924, [A], 105, 500.l5 P.W. Bridgeman, Proc. Nat. Acad. Sci., 1924, 10, 411; A., ii, 818.16 A. E. van Arkel, Physica, 1923, 3, 76; A., 1924, ii, 558; F. S. Goucher,l7 W. L. Bmgg, Proc. Roy. SOC., 1924, [A], 105, 16; A., ii, 109.Phil. Mag., 1024, [V;], 48, 800.REP.-VOL. XXI. 226 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with four molecules of CaCO, per cell; the symmetry is that of theholohedral space-group Qh16. There is a remarkable resemblancebetween the dimensions and atomic configurations of the twoforms, the (GO,) groups being almost identical in shape and size.Whereas the arrangement of calcium atoms in calcite approximatesto that of cubic close-packing, the corresponding arrangement inaragonite is nearly hexagonal close-packing. Corresponding to thefall in symmetry as we pass from calcite to aragonite, we findthat the (CO,) group has lost its triad axis and possesses now onlya plane of symmetry, that is, the original equilateral triangle ofoxygen atoms hams become slightly distorted to an isosceles triangle.The geometrical consequence of this is that the three oxygenP l G .1.Environment of (CO,) group in ( a ) calcite, and ( b ) aragonite.atoms in aragonite are not strictly equivalent, but probably thisdoes not mean anything chemically. We should expect the actof crystallisation to be accompanied by slight distortions from theideal shape of the “ free ” molecules. Fig. 1, taken from Bragg’spaper, gives a clear idea of the essential difference between thecalcite and aragonite arrangement.I n both crystals the (CO,) groups are found between successive(but oppositely directed) triangles of calcium atoms, but whilstin calcite each oxygen “touches ” two calciums, in aragonitethree calciums are involved, that is, the change from calcite toaragonite is accompanied by a rotation of the (CO,) groups through30” to a rather more symmetrical position with regard to theenclosing calcium atoms.The twinning of aragonite about the(110) planes is simply explained by the above structureCRYSTALLOGRAPHY. 227This investigation has very properly been used as the basis of anattempt t o co-ordinate the optical properties of the two mineralsby aid of the atomic configurations thus revealed by X-rays.lsThe following table summarises the striking connexion (pointedout by Mr.T. V. Barker) between them..___I-----__________-----------------------------------------------------------------------------( € = 1.486 (ElectricjC k lcit efor Dlinevector \ I 1 t o ;triad axis). :w = 1.658 (Electric Ivector IP t o ;triad axis). :Uniaxial (axial :A vagonite(2V =18" 10'for Dline.)a= 1-530 (Electric8=1*681 ( ,.y=1*686( y yAcute bisectrix . . .plane (100).vector I/ 1 to c-axis).,Y 9 , Y Y @-axis).Y Y Y , 1 , b-axis).c-axis. Optic axial1 angle = 00). j.-_____________-_______________________L-------------------------------~-------------------------The above refractive-indices indicate that the polarisation fora given field is much greater when the field is parallel to the (CO,)groups than when it is perpendicular to them.Consequently,since the accepted refractivities of the calcium, carbon, and oxygenatoms show that over 80% of the total refractivity is due to theoxygen atoms alone, the origin of the strong birefringence must belooked for in the peculiar form of the (CO,) groups. This is justwhat we should expect from a very simple electrostatic consider-ation of the effect of an electric field on atomic equilateral trianglessuch as constitute the (CO,) groups in these crystals. It is easyto see how a field acting in the plane of the triangles will be moreeffective in causing polarisation ( i . e . , a separation of positive andnegative charges) than would be a field acting perpendicularly tothe triangles.Thus, knowing the relative positions of the atomsin the two cases and the extent to which they become polarisedunder a given electric field (as deduced from the atomic refractivitiesof the atoms), the way is made clear to a comparatively straight-forward calculation. The author, following this line of argumentand making the further assumption that the atom, when polarised,has an external field identical with that of an electric doubletplaced at its centre, thus calculated the absolute values of therefractive indices and obtained results which differ from theobserved values by only 1 or 2%.This is a great triumph for crystallography and, we confidentlyhope, only the beginning of a process which will ultimately leadto the exact quantitative analysis of the optics of any givencrystalline structure.The same author, in collaboration with Prof.S. Chapman, haslately extended his work on the rhombohedra1 carbonates stillfurther into the realms of interatomic reactions. In a paperlq W. L. Bragg, Proc. Roy. SOC., 1924, [A], 105, 370.I 228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.read before the Royal Society on November 6th an account wasgiven of a calculation of the rhombohedral angle of these carbon-ates. As in the case of the refractive indices, the assumptionsmade were exceedingly simple-merely that the atoms of known'' sizes " and positions could be treated as hard spheres acting oneach other with forces which vary inversely as the square of thedistance-and the results are quite satisfactory.The calculatedconfiguration of minimum electrostatic energy possesses an anglediffering from the experimental by 3 4 " only, and for thevariations of the rhombohedral angle, as we pass along the series,the results are better still.While on the subject of these rhombohedral carbonates it isconvenient to mention here a recent papcr by Wyckoff and Mer-win19 in which the authors dcscribe an X-ray analysis of thestructure of dolomite. They have confirmed what has been longsuspected of dolomite,19" that it is of lower crystal symmetry thancalcite-an observation which alone shows that it is not merelya mixed crystal of approximate molecular proportions but a truechemical compound, CaCO,,(Mg,Pe)CO,, with a crystal-form of itsown.It is noteworthy that the magnesium is replaceable by ironup to 30% with scarcely any change in dimensions, a fact whichindicates a striking similarity between these two elements whenin this form of combination. The space-group is probably Cij(i.e., rhombohedral symmetry), one molecule of CaCO,,(Mg,Fe)CO,per cell, with the following atomic positions : Ca, (000) (or (#&)];Mg (or Fe), (+Q& [or (000)l; C, (uuu) (GU.ii) ; 0, (qp) ( y a ) ( z q y )( Z ~ Z ) (@z) (Zsg); which means that the structure resembles thatof calcite, except that alternate layers (perpendicular to the triadaxis) of calcium atoms are replaced by atoms of magnesium (oriron). As before, the (CO,) groups are enclosed between thesuccessive layers of metallic atoms.The Xtructurc of Graphite and Related Compounds.One of the most interesting crystallographic researches of theyear, and one which is of direct interest and possibly of greatsignificance for chemists, is fhe determination of the structureof graphite.Largely owing to the difficulty of obtaining singlecrystals, convincing work on this substance has been long delayed.It is frue that two independent investigations were carried out in1917,20 but the powder method used in those researches led to19 R. W. G. Wyckoff and H. E. Merwin, Am. J . Sci., 1924, [v], 8, 447.lSa W. L. Bragg, Proc. Roy. SOC., 1914, [AJ, 89, 488.2O Hull, Physical Rev., 1917, 10, 661; Debye and Scherrer, Physikal. Z.,1917, 18, 291229 CRYSTALLOQRAPHY.conflicting results, Hull advocating a hexagonal and Debye andScherrer a rhombohedra1 lattice.Since then, Hall’s structurehas found most favour, perhaps because it is built up of hexagonalrings of carbon atoms, recalling the well-known concept of organicchemistry and a similar arrangement in the structure of diamond.Although the evidence is definitely against Hall’s choice of indi-vidual atomic positions, this year’s work has shown that the prefer-ence for his structure was justified to the extent that the hexagonallattice chosen by him is correct. The structure of Debye andScherrer must be rejected.The results of two more investigations (also quite independent)have been published almost simultane-ously by Hassel and Ma,& 21 in Ger-many and by Bernal z2 in England.Itis exceedingly gratifying that the con-clusions drawn in the two examinationsare identical. I n both cases, the chiefmethod of attack was by means ofrotation photographs of single crystalsof natural and of artificial graphite, butthe deductions from these have beenstrongly confirmed by other resultsfrom the ionisation, powder, and Lauemethods, respectively. Experimentally,the two researches have followed similarlines, as is natural, but, strangelyenough, the theoretical discussions areso dissimilar that we cannot now butbelieve that their identical conclusionsFIG. 2.h 7!LIIII i IIIII1IIIhave at last given us the true structure of graphite.As mentioned above, the unit cell (Fig.2) is of the hexagonaltype and contains four atoms. The dimensions are ( a ) c = 6-79,a = 2.46 (Hassel and Mark), ( b ) c = 6.82 & 0.04, a = 2-45 & 0.03,c/a = 2.77 (Bernal). Repetition of this cell produces the structureshown in Fig. 3, consisting of layers of $at hexagonal rings ofcarbon atoms separated by a comparatively large distance (3.4B.U.). The distance of closest approach of the carbon atoms inthe hexagons is about 1.43A.U., as opposed to 1.54A.U. in dia-mond. The symmetry of the complete structure is apparentlyhexagonal holohedral, D&.The structure of graphite shows remarkable differences fromthat possessed by diamond, as, indeed, it is right to expect. The2l 0. Hassel and H. Mark, 2. PhysiE, 1924, 25, 317; A , , ii, 721.22 J.D. Bernal, Proc. Roy. SOC., 1924, [ A ] , 106, 749230 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,great difference in mechanical properties, due to the fact that inthe former the atoms are linked closely in one plane only, andthe absolutely opposed optical properties, due to the “ looseness ”of the fourth electron in graphite, are consequences not merely ofdifferent arrangements of similar atoms, but of a fundamental dijfer-ence in the natures of the atoms themselves. Whereas it appearsreasonable to adopt Bohr’s earlier carbon atom (i.e., four 2, orbitsarranged tetrahedrally) for the diamond, his later suggestion(three 2, orbits and one 2, orbit) is more suitable to graphite,the unique fourth electron being undoubtedly the cause of themetallic properties which characterise this substance, and of theFIG.3.great difficulty which is experienced on attempting to convert itinto diamond.23An interesting confirmation of the uniaxial nature of graphitehas recently been carried out by P. Ga~bert,~* who has shown thatin very thin flakes graphite is green by transmitted light, andthat it is uniaxial, optically negative, and has a refractive indexof about 2.The precise significance of the graphite structure to organic23 For a fuller discussion of the part played by the carbon atom in crystals,the reader might consult the lecture “The Carbon Atom in CrystallineStructure,” W. H. Bragg, J . Frankl. Inst., 1924, 198, 615.24 P. Gaubert, Compt. rend., 1923, 1’77, 1123CRYSTALLOGRAPHY.23 1chemistry it is somewhat difficult to estimate with confidence.It gives a certain support to the “flat ring hypothesis,” andcertainly it is in keeping with what is known of the numberand constitutions of the benzene substitution products. On theother hand, there is considerable evidence for the “puckeredring,” such as is contained in diamond, for there seems little doubtthat naphthalene molecules are only centro-symmetrical in thecrystalline state, whilst recent work on crystallised benzene indicatesthe same symmetry for the benzene molecules. At the same time,it is essential to remember that in a puckered centro-symmetricalring of carbon atoms, even although in such a ring there are, strictlyspeaking, three different pa’irs of similar atoms (i.e., each atom isstrictly equivalent only to the one diametrically opposite to it),we cannot as yet be quite sure what exactly is the chemical effect,if any, of the geometrical dissimilarity.I n other words, we maynot up to the present infer that the small geometrical differencebetween two neighbouring atoms of the ring will of necessity involvea definite difference in the response of these two neighbouringatoms to the action of chemical reagents. Indeed, it seems morelikely that the action of such reagents is in general sufficient toovercome any small geometrical differences in the atoms that areacted upon, the final result being a complete change-over to theconfiguration demanded by the new product. The geometricalconfiguration of this new product may be the same as that of thering from which it was produced, but there is no a priori reasonfor assuming it to be so. In fact, it is much more reasonable toassume that the apparently conflicting conclusions which havebeen deduced from different researches on the symmetry of benzeneand its products are only expressions of the fact that the symmetryof the ring is not so permanent a quantity that it is retainedunaltered through successive chemical or physical changes.Two attempts have been made this year to determine the crystal-structure of benzene.The first 25 was by the powder methodand gave results in fair agreement with those obtained by Broom6last year,26 but by the unaided powder method it was not possibleto determine unequivocally the unit cell and the molecular sym-metry.The second attempt, by H. Mark,27 was by the rotating-crystal method. The results give, provisionally, 6.9, 9.7, and7.4A.u. for the three axes, with four molecules of C6H6 per celland a space-group of either Qhll, Qh15, or Qh16 (i.e., rhombic bi-pyramidal). The molecule is stated, although on what grounds is25 E. D. Eastman, J . Amer. Chem. SOC., 1924, 46, 917; A,, ii, 448.26 B. Broom6, Physikal. Z., 1923, 24, 124.27 H. Mark, Ber., 1924, 57, 1826232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.not quite clear, to be centro-symmetrical. A similar conclusionis drawn for hexachloro- and hexabromo-benzene (monoclinicprismatic, CZh4, two molecules per cell).Low-temperature Investigations.Chiefly on the Continent are now in progress investigations ofthe crystal-structure of various substances solid only at low tem-peratures.This is not the place to describe in detail the apparatusand technique of these experiments. The rather meagre resultsobtained to date on such an easily frozen substance as benzeneshow only too well the great dficulty attending low-temperaturecrystal-analyses of any but cubic substances. A preliminaryaccount of the Leiden crystal researches is given in the ‘‘ Reportsand Communications of the Fourth International Congress ofRefrigeration,” London, June, 1924, and it will be sufficient forour purpose to mention briefly the apparatus there described.Powder photographs are taken in an evacuated Debye camera intowhich projects a fine capillary which is the end of a Dewar flaskcontaining liquid air.The gas to be solidified is admitted to thecamera and condenses only on the outside of the cold hollowcapillary. Since the latter is located a t the centre of the camera,a powder photograph of the fine cylinder of solid gas can be takenin the usual manner. In the above reports, J. de Smedt andW. H. Keesom describe an examination of solid nitrous oxide.The results agree with a cubic cell of side 5.77A.U. With fourmolecules per cell the density is then 1.52, whilst a t the freezingpoint it is known to be 1.229. The authors consider this to besatisfactory enough and proceed to describe a structure in whichthe alternate members of the eight small cubes into which theunit can be divided are each occupied by one molecule of nitrousoxide, lying along non-intersecting triad-axes-but the argumentsand conclusions do not carry conviction.At the same laboratoryphotographs have been taken of ice, carbon dioxide, nitrogen,oxygen, and argon also, but the results are not yet to hand, exceptthat solid argon has been announced as cubic. This elementhas also been examined by F. Simon and C. von Simson,28 whofind that it has the close-packed (face-centred) cubic lattice ofside 6.42 A.U. at 40” Abs. From this structure the “atomicradius ” is 1.92 A.U., whilst the ‘‘ mean atomic radius ” of potassiumand chlorine in potassium chloride, where they are supposed tohave outer electron shells similar to that of argon, is 1.56 A.U.Thisdifference is considered by the authors as a variation of ‘‘ atomicradius” with interatomic forces, and, after the manner of Born,2. Physik, 1924, 85, 160; A., ii, 588CRY STALLOURAPHY. 233is used as the basis for a rough calculation of the interatomic field.They thus arrive a t an attractive force between the atoms whichis inversely proportional to the 9th power of the distance, and arepulsive force inversely proportional to the 15th power of thedistance.The same problem has been considered at greater length andby aid of information derived by the methods of the kinetic theoryby J. E. J0nes.2~ He arrives at the 5th and 15th powers for solidargon, and the same values also for potassium chloride and calciumsulphide, if we assume that the sulphur, chlorine, potassium, andcalcium ions have the same structure and therefore the same outerfield as argon, with the addition of negative and positive electro-static charges.Incidentally this author mentions that it can beshown from his treatment that, of the three possible cubic structures,the face-centred has the least potential energy.Simon and von Simsonm have also investigated the structureof solid hydrogen chloride. They find two modifications, one ofwhich, stable above 98" Abs., is cubic face-centred with side 5.50A.U. With regard to the other form, the results are insufficientto show more than that the symmetry is lower than cubic. Thedensity data indicate that hydrogen chloride contracts 15% onfreezing and 2.5% on transition at 98" Abs.We may conclude this section with a brief reference to quitea remarkable result which has been obtained in the Leiden labor-atory-that no difference can be detected in the strricture of leadwhen it suddenly becomes supra-conducting Hear the absolutezero of temperature.The electric resistance suddenly vanishes,but the structure still remains face-centred cubic. This pheno-menon recalls an apparently similar behaviour in iron, which iscontent with only two types of crystal-structure (body-centredfor a-, P-, and &iron, face-centred for 7-iron), although four modi-fications of the element have been known for some time. Theimportance of these seemingly disappointing results must not belost sight of in any sound theory of magnetism and supraconductivity.Other Inorganic Crystals.Rhombic X~lphur.~~-The symmetry is holohedral, space-groupQh2*, a = 10.61, b = 12.87, c = 24.56 A.U., and there are 128atoms per cell.The space-group &h24 of the orthorhombic systemis face-centred and exactly analogous to the diamond structurein the cubic system, in which, it will be remembered, alternatemembers of the eight smaller cubes of the unit cell are also occupied.29 Proc. ROY. SOC., 1924, [A], 106, 709.81 H. Mark and E. Wigner, 2. physikal. Chem., 1924, 111, 398; A., ii, 650.30 LOC. cit., 21, p. 168.I234 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It follows from this structure of or-sulphur that, in the crystal-lattice, groups of 4, 8, or 16 atoms are associated, i.e., the crystal-molecule is either s,, X,, or S16.The centres of gravity of thegroups of sixteen atoms form a rhombic diamond lattice.Ammonium Zirconium and Ammonium Hafnium Fluorides,(NH,)&rF, and (NH,),HfF,,.32-These compounds are simplecubic with sides 9.353 and 9.400 A.U., respectively ; four moleculesper cell, space-group Oh*. Like those for potassium chloroplatinate,in which the octahedral [PtCI,] ion is surrounded by a furthersphere of eight potassium ions, the results for these crystals are inaccordance with the Werner theory of co-ordination. We firstfix our attention on a certain smaller cube a t the middle of theunit cubic cell. Alternate corners of this smaller cube are occupiedby [ZrF,] and fluorine ions.The [ZrF,] complexes are octa-hedral, although in the crystal possessing strictly only the sym-metry of the calcite class (D3d). The six fluorine atoms are each1-77 A.U. from the central zirconium atom and 2.5B.U. fromeach other. They may be considered as the first co-ordinationsphere. Next we see arranged round them a second sphere of six(NH,) groups, also arranged octahedrally, each a t a distance of3.52 B.U. from the centre of the [ZrF,] complex and 2-71 A.U.from the nearest of the six fluorines which form the f i s t sphere.To get an idea of the position of these (NH,) groups in t'he unitcell, the reader will find it easy and instructive to sketch out forhimself such a diagram as is given in the original paper. Theyare located six a t the face-centres of the small inner cube mentionedabove, and the other six distributed along the edges of the largercube constituting the unit cell.Two will be found in each edge,equidistant from the corners. The (NH,) groups are naturallygrouped in an exactly similar fashion about the fluorine atoms ofthe second kind which, as mentioned above, occupy alternatecorners of the small inner cube. Finally, six of the fluorine atomsof the second sort may be considered to form a third sphere abouteach zirconium, at a distance of 4.66A.U.The above forms a very striking and beautiful piece of crystal-analysis. It will appeal to the chemist also as an equally elegantstudy in co-ordination. It should be noticed that in the crystalthe zirconium atoms and the fluorine atoms of the second sorthave the twelve-fold symmetry of the calcite class, (DS), thenitrogen atoms have the four-fold symmetry of the rhombic pyra-midal class, and the fluorine atoms constituting the [ZrFE',] com-plexes only the two-fold symmetry of the monoclinic domaticclass.From the density of the impure hafnium salt (containing33 0. HasseI and H. Mark, 2. Physik., 1924, 27, 89; A,, ii, 817CRYSTALLOGRAPHY. 23515% of the zirconium salt) the atomic weight of hafnium worksout to be 179 & 5.4.CaZomeZ.33-In the case of this crystal, the tetragonal cell(6.30, x 10.90 A.U.) contains eight mercury atoms and eightchlorine atoms, which are arranged in a fashion which recallsthat of rock-salt, except that in the vertical rows of atoms wehave, not ClHgClHg .. . . . , but ClClHgHgClClHgHg . . . . . FromHg to C1 vertically is 2.72 A.U., while horizontally it is 3.15 A.U.This result is considered by the author to indicate the formula Hg2C12.Aluminium Nitride.34-This is a hexagonal close-packed arrange-ment (a = 3-11 A.U. and cia = 1-60), in which each atom ofeither kind is surrounded tetrahedrally by four atoms of the otherkind, the interatomic distance being 1.89 A.U.Other Organic Crystals.(a) Succinic Acid, (b) Succinic Anhydride, (c) S~ccinimide.~~-(a) Monoclinic holohedral (C,h2) with two molecules per cell. Thestructure suggested makes the molecule symmetrical about aplane (centro-symmetry is the only alternative) containing bothCO,H groups, and readily explains the cleavage and twinning.( b ) The crystal class is either rhombic pyramidal (CZv1), moleculesasymmetric, or rhombic bipyramidal ( Q1&l), molecular symmetricalabout a plane.(c) Symmetry again Qhl, molecules asymmetric.A simple structure is suggested which is in conformity with theconclusions drawn for the acid. I n both cases, a tetrahedralarrangement of the four carbon atoms is indicated.(a) Acetaldehyde-ammonia, (b) Meta~etaZdehyde.~6-(a) Is ditri-gonal scalenohedral (D3d5) with six molecules per cell. Thesecan be so arranged in the cell, each molecule being symmetricalabout a plane, that the aldehyde groups of the separate chemicalmolecules are adjacent. This is taken by the authors to indicateit tendency to polymerisation even in the crystalline state; ( b ) istetragonal, either C45 or C42.The cell is body-centred and con-tains eight acetaldehyde molecules, not more than four of whichcan form a crystal-molecule. The polymeride cannot be thusmore complex than tetrameric.Oxalic A~id.~~-The anhydrous acid is rhombic bipyramidal,space-group Qh15 with four molecules per cell. The molecules arecentro-symmetrical and show no obvious association with eachother. The dihydrate is monoclinic prismatic, space-group CZh5,33 C. Mauguin, Compt. rend., 1924, 178, 1913; A., ii, 588.34 H. Ott, 2. Physik, 1924, 22, 201; A., ii, 298.35 K. Yardley, Proc. Roy. Soc., 1924, [A], 105, 451; A., ii, 382.36 0. Hassel and H. Mark, 8. physikal.Chem., 1924, 111, 357; A., ii, 651.87 H. Hoffmann and H. Mark, 2% physikal. Chem., 1924,111,321 ; A.,ii, 650.I' 236 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.two molecules per cell. These are again centro-symmetrical, thewater being apparently part of the molecule.(a) Carbon Tetraiodide, (b) Carbon Tetrabr0mide.2~-1n the cubicform both (a) and (b) appear to have the simple cubic lattice, and,if the crystallographic evidence can be taken to indicate the hexakistetrahedral class (Tdl), each molecule is then tetrahedral; (b) inthe monoclinic prismatic form possesses eight molecules of CBr,per cell, space-group either C2?: or C2h6. The author concludesthat the crystal-molecule is C2Br8, which accounts for the changefrom cubic to monoclinic, since the two CBr4 molecules distorteach other.Jliscellaneous.Piezo-electricity and Molecular Di~symmetry.~~--In this study usehas been made of amplification by valves.More than thirtyoptically active substances, including camphor derivatives, alkaloids,and complex salts, have been tested and found to be piezo-electric.In many of these structures the absence of a centre of symmetrywould not have been deduced from the habit or corrosion figures.The author thus recommends this method as very reliable whenordinary met hods fail.Rotatory Dispersion of Tartaric Acid.3?---Longchambon findsthat in the crystalline state the rotatory dispersion of tartaricacid is strong but quite normal. The ratio for the rotations ofthe indigo and yellow mercury lines is 2-14.From examinationof the dispersion of solutions he concludes that the dispersion ofthe laevo-component contributing to the anomalous dispersion ofthe solutions is between 2 and 2.2, a fact which is then taken toprove the identity of this hvo-component with the active systempresent in the ordinary crystallised acid.Deformtion and Xtrength of CrystaZs.40-The " elastic-limit "of a crystal, as defined by the minimum strain producing distortionof the Laue photograph, is a well-defined constant for a givenmaterial and temperature. It decreases to zero a t the meltingpoint. With rock-salt, beyond this elastic limit, gliding takesplace along the (110) planes, the spots belonging to these planesalone remaining sharp on the Laue photograph.The plasticdeformation increases its tensile strength some twelve times. Thetheoretical and observed values of the tensile strength of rock-salt do not agree, but this is probably explained by surface crack-ing, which is healed by immersion in water. Crystals immersedin water have a greatly increased tensile strength.R. Lucas, Compt. rend., 1924, 178, 1890; A., ii, 586. '@ L. Longchambon, ibid., p. 951 ; A., ii, 373.40 A. JoffB, M. Kirpitschewa, and M. A. Lewitzky, 2. Phyaik, 1924, 82,286CRYSTALLOGRAPHY. 237New Books.(1) “ The Natural History of Crystals.”Pp. xii + 287 + 33 plates.By Dr. A. E. H.Tutton. (London : Kegan Paul andCo., Ltd., 1924.) 15s. net.-This is a charming, semi-popularbook in Dr. Tutton’s inimitable style. It has been brought verymuch up to date (it is really a re-issue of his well-known book“ Crystals,” published in 1911) and forms a fascinating story frombeginning to end. It is beautifully illustrated.By Dr. J. W. Evans andG . M. Davies. Pp. vii + 134. (London : Thomas Marby & Co.,1924.) 9s. 6d. net.-This book is intended as a concise but easyintroduction to crystallography, and is admirable except in so faras it advocates still another nomenclature for use when describingthe thirty-two crysfal classes. At the present stage of the subject,when its rapidly growing importance necessitates avoiding any-thing which might impede its assimilation by students of otherbranches of science, such an attempt to introduce still anothernotation is not well advised.(3) “La Structure des Cristaux.” By Ch. Manguin. Pp.281 + 125 figures. Vol. 6 des ConfBrences-Rapports de Docu-mentation sur la Physique. (Paris : Libraire Scientifique AlbertBlanchard, 1924.) 20 Francs.-For any one who is in need of athorough, but not too abstruse or expensive, work on the methodsand results of crystal-analysis, we can heartily recommend thisbook by the well-known French crystallographer. The last partof the book is devoted to a survey of the various types ofcrystal-structure as revealed by X-ray analysis and structure-theory, and there is also a very good bibliography(4) “ The Structure of Crystals.” By Ralph W. G . Wyckoff.A. C. S . Monograph No. 19. (NewYork : The Chemical Catalogue Company, Inc., 1924.) $6000.-This is no doubt the most complete text-book on crystal-analysisthat has yet been written, and is deserving of the highest praisefor the enormous amount of labour which it must have involved.Although written for the American Chemical Society, it is probablytoo difficult for those who have not had a fairly thorough groundingin crystallography-but as a book of reference for crystal-analystsit is unique. The latter part of the book includes a completesurvey of known crystal-structures and an exhaustive bibliographycarried up to the end of 1923. It is unfortunate that still anothernotation is recommended. Whatever the short-comings of theSchoenflies system, crystallographers throughout the world havebecome accustomed to it.(2) “ Elementary Crystallography.’’Pp. 464 + 213 illustrations.W. T. ASTBURY.W. H. BRAGQ

ISSN:0365-6217    

DOI:10.1039/AR9242100220

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

SUB-ATOMIC PHENOMENA AND RADIOACTIVITY .*The Isotopic Constitution of the Elements.DURING the two years covered by this Report steady progresshas been made by means of the mass-spectrograph. The dis-covery of further small deviations from the whole-number rulehas necessitated the introduction of the term " mass-number."This is theoret>ically the number of protons in the atom, practicallyit is the nearest whole number to its weight expressed on theordinary chemical scale. These integers are identical in all casesso far as our knowledge extends at present.l An investigation ofmethods by which the positive rays, or as they may now be moregenerally termed mass rays, of the metallic elements could begenerated resulted in the working out of the method of " acceler-ated anode rays " 2 which has been exceedingly valuable in ex-tending the work to elements with which it is impossible to dealby ordinary gaseous discharge.The first use to which this wasput was a verification of the whole-number rule for the light metallicelements. The only one of these to show measurable deviationwas lithium. The masses of its isotopes were estimated to be7.006 & 0.005 and 6.008 & 0.005, respectively. No deviation wasdetected in beryllium, sodium, magnesium, aluminium, potassium,or calcium. This leads to the remarkable conclusion that thetwo isobaric atoms A40 and Ca40 probably do not differ in weightby 0.1%, although the structure of their respective nuclei mustbe different, for one contains two more electrons than the other.Silicon.-The third isotope Si30 of this element has been con-firmed.3 in agree-ment with the results obtained with band spectra (p.244).Scandium, Titanium.2-The principal constituents of these twoelements, which are probably simple, have mass-numbers 45 and48, respectively, but the lines were not obtained with sufficientintensity to preclude the possibility of small quantities of isotopes.Vanadium, Chromium, Manganese, Cobalt .2-All these elementsgave satisfactory single lines, showing that they are simple andIts line is a little less intense than that of* This Report covers the years 1923 and 1924.F. W. Aston, Phil. Mag., 1923, [vi], 45, 945; A., 1923, ii, 353.Idem, ibid., 1924, [vi], 47, 387; A., ii, 225.Idem, Nature, 1924, 114, 273.23SUB-ATOMIC PHENOMENA AND RADIOACTIVITY.239that their mass-numbers correspond to their chemical atomicweights.Ir~n.~-The second isotope, Fe54, is confirmed. It appears tobe present to the extent of about 5%.Copper.2-The effects obtained with copper were faint but veryconclusive, as both in intensity and position its lines appearedexactly as statistical considerations had led one to expect. Theselines correspond to 63 and 65 and show no measurable deviationfrom the whole-number rule.Gallium is also an element consisting of two isotopes. Theyare of mass numbers 69 and 71. The former is in greater abundancein agreement with the latest value of the atomic weight.is a complex element with three isotopes of mass-numbers 70, 72, 74 of intensities roughly proportional to 2 : 4 : 5.As no deviation from whole number is detectable, this suggestsa mean atomic weight of 72-6, a value which has been obtained inthe recent work of Baxter.5 It will be noticed that Ge70 is isobaricwith the weakest and heaviest isotope of zinc and that Ge74 isisobaric with the very weak, lightest isotope of selenium.Strontium.-In the first analysis of this element 2 it appearedto consist entirely of atoms of mass-number 88, but later results4revealed a very faint companion a t 86.The principal line givesevidence of divergence from a whole number, its mass being estim-ated as 7843. Even with this allowance, the present chemicalatomic weight is probably a little low.GermaniumYttrium 2 is a simple element of mass-number 89.Zirconium.-The analysis of this element has presented peculiadifficulties.6 It gives mass lines 90, 92, 94 and a doubtful one(96). The masses appear to be a little less than whole numbers.Silver 2 gives results exactly in accordance with expectation,having two isotopes, 107, 109, almost equal in intensity.Cadmium is a very complex element.' It has six isotopes, 110,111,112,113,114,116, and their order of intensity appears identicalwith that of the fist six isotopes of tin.This is a very strikingcoincidence, and may have a deep significance in connexion withthe relative stability of the nuclei of isotopes.Indium 8 appears to be simple 115, but the line is not sufficientlyintense to preclude the possibility of other constituents in smallproportion.4 F.IT'. Aston, Nature, 1924, 113, 856; A., ii, 445.G. M. Baxter and W. C. Cooper, jun., Proc. Amer. Acad. Arts Sci., 1924,59, 235; A., ii, 690.13 F. W. Aston, Nature, 1924, 114, 273; A., ii, 640.Idem, ibid., 717.8 Idem, ibid., 192240 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY .Element .H .........H e .........Li .........Be .........B ......... c .........N .........0 .........F .........Ne .........Na .........Mg .........A1 .........Si .........P .........s .........c1 .........A .........K .........Ca .........s c .........Ti ......... v .........Cr .........Mn .........Fe .........co .........Ni .........cu .........Zn .........Ga .........Ge .........As .........se .........Br .........Kr .........Rb .........Sr .........Y .........Zr .........3 :::::::::In .........Sn .........Sb .........Te .........I .........x .........c s .........Ba .........La .........Ce .........Pr .........Nd .........H g .........Bi .........Table of Elements and ISOtupeS .(Numbers in brackets are provisional only.)Atomicnumber .1234667891011121314151617181920212223242526272829303132333435363738394047484950515253545556575859608083Atomicweight .1.0084-006.949.0210.8212.0014.0116.0019-0020.2023.0024.3226.9628.0631.0232.0635.4639.8839.1040.0745.1048.1051.0052.0054.9355.8458.9758-6863.5765.3869.7272.3874.9679-2079.9282-9285.4487.6388-90107.88112.41114-80118-70121.77127.5126.92130.20132.81137.37138.91140.25140.92144.27200.60209.00(91)isotopes .112121111213131122221111121224231626221$1617 (8)2317 (9)1(;I21(4)(6)1Minimum Mass-numbers ofnumber of isotopes in orderof intensity .147.6911. 10121416192324. 25. 262728. 29. 30313235. 3740. 3639. 4140. 44454851526556. 545958. 6063. 6564. 66. 68. 7069. 7174. 72. 707580.78. 76. 82. 77. 7479. 8184. 86. 82. 83. 80. 7885. 8788. 868990. 94. 92. (96)107. 10920. 22114; 112.110.113.111. 116115120. 118 . 116 . 124 . 119 .i i 7 . 122. (121) '121. 123128. 130 . 126127 . .129. 132. 131. 134. 136.128. 130. (126). (124)133138. (136)139140. 142141142. 144. 146. (145)(197). 202. 204. 198. 199.20920SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 241Tellurium.-This element, which has a special interest in con-nexion with its anomalous position in the table of atomic weights,gives three lines, 126, 128, 130, of intensity roughly 1 : 2 : 2.Although these appear to be due to masses rather less than wholenumbers, the mean weight seems probably more than 12€L7 Thechemical one at present in use is 127.5, but a new method ofdetermination gives 127.8.*a Tellurium appears to have all itsmass-numbers shared by xenon.Barium was a t first thought to be a simple element of mass-number 138 with an actual atomic mass of about 137~8.~ A secondsearch under more advantageous conditions indicated possibilitiesof a very faint companion 136.6 This is, however, quite inadequateto account for the chemical atomic weight 137.37, which is probablytoo low.Lanthanum, Praseodymium are both simple elements of mass-numbers 139 and 141, respectively, as their chemical atomic weightswould lead one to e ~ p e c t .~Cerium has a strong isotope 140 and a weak one 142.6Neodymium is complex with mass-numbers 148-isobaric withcerium-144, 146 and possibly (145).6Bismuth.7-This is the heaviest element which has been analysedso far.It gives a single line and is doubtless a simple element ofmass-number 209, as its atomic weight suggests.In addition to these results, Dempster has confirmed his previousconclusions on calcium and zinc.l* It will be seen from the tableof isotopes given that, with the exception of a gap of five, Nb-Pd,all the known elements up to atomic number 60 have been analysed.The Periodic Xystem of the Elements.Certain arithmetical regularities connecting atomic number withatomic weight and valency have been pointed out by F. Loewinson-Lessing 11 and by A. Rius y Mir6.12 Harkins has further developedhis system of atomic species with particular relation to their nuclearstability and isotopic number.13 The most important contributionto this branch of the subject is that of A.S. Russell,14 who, in aseries of papers, has applied the known properties of radioactivebodies to predict the occurrence and relative abundance of the*a P. Bruylants and J. Michielsen, Bull. Acad. roy. Belg., 1919, 5, 119; A.,1923, ii, 153.F. W. Aston, Nature, 1924, 113, 857.lo A. J. Dempster, Physical Rev., 1922, 20, 631; A,, 1923, ii, 413.11 Compt. rend., 1923, 176, 307; A., 1923, ii, 146.l2 Anal. Pis. Quim., 1922, 20, 496; A., 1923, ii, 146.lo Phil. Mag., 1924, [vi], 47, 1121; 48, 365; A., ii, 445.J . Amer. Chem. Soc., 1923, 45, 1426; A., 1923, ii, 553242 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.isotopes of the inactive elements.He does not assume, nor isit essential to his theory, that all elements are actually evolvedby radioactive disintegration. His method is to arrange all knownand hypothetical radioactive elements and their products intofour series, two real and two hypothetical, and examine the periodicbehaviour as regards stability. The relations so found he thenapplies to the elements generally. A study of this periodicbehaviour leads, for instance, to three fundamental rules :(a) The maximum difference in mass-number of any group ofisotopes is 8. (b) Elements of odd atomic number may have twoodd mass-numbers only, and these differ by two units. (c) Elementsof even atomic number may have both odd and even mass-numbers,and (with two exceptions) the number of the former is limited totwo and their difference is two units.These are not seriouslycontravened by the known isotopes of the elements of fairly highatomic number to which he confines his general argument. Fromthese and several other relations derived in the same way togetherwith a few reasonable assumptions, he is able to predict the isotopesof an element from its atomic weight. Although his argumentsare in some cases difficult to follow and to appraise, the successof his predictions is certainly noteworthy. We have here one ofthe first definite steps towards the enunciation of a periodic lawwhich we shall be able to apply to the nuclear properties of atomsjust as the present one can be applied to their extranuclear orchemical ones.Abundance of Atomic Xpecies.-Some interesting deductions onthe stability of nuclei have been obtained by plotting on a log-arithmic scale the abundance of each known atomic species againstits mass-number.15 This clearly shows the extreme discrepancybetween the ratio of the abundance of the isotopes of a singleelement and the ratio of the abundance of the elements them-selves, e.g., there are only about three CP5 atoms to one CP7 andabout two Ga69 atoms to one Ga71, yet there are lo9 times moreatoms of chlorine than of gallium.In the case of elements of oddatomic number, it is shown to be impossible to ascribe this to thelimited range of methods of detection of isotopes. Hence it mustbe concluded that isotopes of an element have some nuclear propertyin common in addition to that of identical nuclear charge.Thisconclusion is supported by the relative masses of the isotopes oftin and xenon and also by other general considerations of nuclearstructure. Purthermore,l6 the a.bundance on the earth of the inertgases appears to be about lo6 times less than that expected from1 5 F. W. Aston, Nature, 1924, 113, 393.16 Idem, ibid., 114, 786SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 243the form of the curve for other elements. It is suggested that theloss of the inert gases from the earth may have taken place duringthe evolution of the solar system.Constancy of Chemical Atomic Weight.Several attempts have been made to detect differences of atomicweight between samples of a complex element from differentsources due to variation in the proportional abundance of itsconstituent isotopes.The results, as before, are strongly negative.The claim 17 to have detected differences in the atomic weight ofantimony from various sources carries no weight, for the deter-minations are provisional only and have not been confirmed.The low combining weight of lead in a Vesuvian contunnite isnaturally attributed to the presence of uranium lead. l 8 Baxter 19has repeated his previous comparison between meteoric and ter-restrial nickel and finds an identical atomic weight, 58.70, forboth. He has also examined cobalt of meteoric and terrestrialorigin, and both varieties give the same value, 58.94.2O A mostimportant and conclusive paper on the subject is that of F.M.Jaeger and D. W. Dijkstra.21 After a general discussion of theevidence already available, they go on to describe their own experi-ments. In these, they worked on the element silicon, which hasas wide a distribution in nature as any complex element, andexamined it by determining the density of tetraethylsilicane madefrom it by the Grignard reaction. After carrying out this operationwith silicons from six different cosmic and six different terrestrialsources, they found no differences of density greater than 0.0006%.By further investigation they were able to show conclusively thateven these small differences are to be attributed to the presence oftraces of by-products too small to be detected chemically. Theyconclude that terrestrial and meteoric silicon give products ofdensity not differing by more than the error of experiment, thatis 0-00004~0, so that the ratio of the isotopes of silicon is constantwithin the limits of the highest accuracy attainable a t present.It is clear from such result's as these that, although the figure forthe chemical atomic weight of a complex element, depending as itdoes on the proportion of its isotopes, may not be so fundamental17 Sheikh D.Muzaffar, J. Anaer. Chem. SOC., 1923, 45, 2009; A., 192318 A. Piutti and D. Migliacci, Atti R. Accad. Lincei, 1923, 32, 468; A . ,19 G. P. Baxter and F. A. Hilton, J. Amcr. C h m . SOL, 1923, 45, 694;20 G. P. Baxter and M. J. Dorcas, ibid., 1924, 46, 357; A., ii, 341.21 Proc. K . Akad.Wetensch Amsterdam, 27, Nos. 5 and 6.ii, 771.ii, 181.A., 1923, ii, 326244 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.as its atomic number or the mass-numbers and actual masses ofits constituent atoms, yet it may for normal inactive elements betreated as a true constant of nature, since no process in natureseems capable of changing it.The Spectra of Isotopes.I n connexion with series spectra, there is comparatively littleto report. A. L. Narayan 22 has subjected the tin lines 5631 and4524 to the highest resol~ition by means of a Lummer plate. Evenwhen the pressure was of the order of 1 mm., both lines were simplein structure, the latter being especially sharp. Since tin is acomplex element with isotopes ranging from 116 to 124, this resultcontradicts McLennan’s view Z3 that the spectral displacement forisotopes should be given by the atomic number multiplied bythe displacement calculated on Bohr’s theory.H. Nagaoka andhis collaborators z4 have investigated the satellites of mercuryand bismuth lines and have formulated a, theory that these arecaused by isotopes. There is little to recommend this view and ithas been unfavourably criticised by G. Runge25 and by R. S.Mulliken.2s This view has led its authors to predict seven isotopesof bismuth, an element since shown to be simple.Band Spectra.-Nulliken has made a very noteworthy advancein this field.27 He shows that the band spectrum attributed byJevons to boron nitride is probably due to boron oxide and reallyconsists of two superposed spectra.These are relabed t o eachother exactly as would be predicted by the quantum theory ofband spectra if the more intense spectrum is due to the moreabundant isotope, Bl10, and the less intense band t o the lessabundant isotope, BlOO. This result furnishes strong support forthe main features of the theory and leaves no doubt as to theisotopic nature of the two related band spectra. In agreementwith the results of the mass-spectrograph, there is no evidenceof the existence of more than two isotopes of boron. With siliconnitride, photographs show that each sufficiently intense Si2Whead of bands on the red side of the central band of the systemis accompanied by two very much weaker heads, one at doublethe distance of the other.These correspond with isotopes SP9and Si30; the former appears to be a little more abundant than the22 Nature, 1923, 112, 651; A., 1923, ii, 807.23 A., 1922, ii, 541, 728.24 Nature, 1924, 113, 459, 532; 114, 245; A., ii. 295, 649.26 Ibid., 113, 781; A., ii, 446.26 Ibid., 113, 820; A., ii, 446.27 Xcience, 1923, 58, 164; A,, ii, 3; Nature, 1924, 113, 423, 489; A.,ii, 294, 295SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 245latter, and there is no evidence of any other isotope. Results of asimilar nature are given by hydrides, but here the separation ismuch smaller on account of the great difference between the massesof the atoms combining.The Separation of Isotopes.Work in this field shows a considerable diminution on that doneduring 1921-1922.This was to be expected, since most of theobvious methods have been exhaustively tested and few new oneshave been devised. E’urther experiments have been done on theirevaporation method by Bronsted and Hevesy, who have attemptedto separate the isotopes of which ordinary lead is supposed t,oconsist by the vacuum distillation of lead chloride. The finalfractions were submitted to Honigschmid 2* for atomic weightdetermination. The mean result for the more volatile fractionwas 207.229 & 0-003 and for the less volatile 207.236 & 0-003, adifference too small to warrant any claim for separation. Harlrins 29describes a large steel apparatus in which 2.5 kg. of mercury canbe dealt with in one operation. The use of liquid air is avoidedand cooling is carried out with ice and in such a way that thefractions can be drawn off continuously.After 268 hours ofoperation with this apparatus and 37 hours with a smaller glassone, they obtained a light fraction of 3.8 g. of mercury, showinga decrease in atomic weight of 0.044 of a unit, and a heavy fractionof 4.4 g., showing an increase of 0.052 of a unit. G. Hertz 3O hasinvestigated the rates of gaseous diffusion against a moving columnof water vapour, and has designed an admirable apparatus for thecontinual separation of helium from neon on a commercial scale.He suggests that the method should give a large separation of theisotopes of neon if the apparatus was suitably modified, but nosuccess has been reported so far. The possibility of separation ofisotopes by ionic migration has been examined by several observers.This was f i s t suggested by Lindemann, but gave negative results.31In the experiments of Kendall 32 the conditions were so arrangedthat the ions moved in an agar-agar gel a t the rate of 12 to 18inches a day.With this arrangement, quantitative separation ofsodium iodide from sodium thiocyanate was obtained after a2 8 0. Honigschmid and M. Steinheil, Ber., 1923, 56, [ B ] , 1831; A . , 1923,W. D. Harkins and S. L. Madorsky, J. Amer. Chem. Soc., 1923, 45,ii, 764.591 ; A., 1923, ii, 322.30 z. Phy&, 1923, 19, 35.31 J. G. Pilley, Nature, 1923, 111, 848; A . , 1923, ii, 554.32 J. Kendall and E. D. Crittenden, Proc. Nut. Acad. Sci., 1923, 9, 75;A., 1923, ii, 282246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.movement of only a few feet, but there was no indication of anyseparation in the case of sodium chloride even after a movementof 100 feet.E. Murmann33 has described many attempts t oseparate isotopes by this and other methods. All gave negativeresults and he concludes that ionic mobilities are dependent onlyon atomic volume and not on atomic weight. B. L. Vanzetti34has tried parchment paper and animal membrane diaphragms toseparate the isotopic sodium chlorides. I n a later herecords a slight change in atomic weight. Attempts have alsobeen made to separate the isotopes of chlorine by adsorption oncharcoa1,36 but without success. The conclusion given in the lastreport on this that there was little hope of separatingisotopes on anything like a chemical scale, is clearly still justified.Artificial Disintegration and Transmutation.Aided by technical improvements in the means of detectingand counting scintillations, Sir E.Rutherford and J. Chadwick 38have made great advances in their experiments on the disintegrationof the nuclei of the lighter elements by bombardment with swifta-particles. By observing from an angle of 90" to the directionof the incident beam, they are able to detect disintegration pro-ducts down to a range of 7 cm., instead of 30 cm. as previously,and at the same time eliminate all effects from hydrogen con-tamination in the element bombarded. Working in this way, inaddition to the elements boron, nitrogen, fluorine, sodium, aluminium,and phosphorus which give protons of range 40 to 90 cm., theyhave now detected protons of range above 7 cm.resulting fromthe disiiitegratioii of neon, magnesium, silicon, sulphur, chlorine,argon, and potassium. The numbers of these protons are small,one-third to one-twentieth of tBhe number obtained from aluminiumunder similar conditions. Their ranges have not yet been measuredaccurately, but those from neon have the shortest-about 16 cm.The effect with beryllium is small and doubtful. The other lightelements, hydrogen, helium, lithium, carbon, and oxygen, give nodetectable effect a t all. In addition, experiments have been made,but no effects observed, with nickel, cobalt, zinc, selenium, krypton,molybdenum, palladium, silver, tin, xenon, gold, and uranium.A noteworthy point in connexion with this work is the marked33 Oesterr.C I L C ~ . Ztg., 1023, 26, 14; A . , 1923, ii, 401.34 Gazzetta, 1924, 54, 89; A., ii, 404.35 Chenb. Zentr., 1024, I, 1013; A . , ii, 650.36 J. Sameshima, K. Aihara, and T. Shirai, J . C'henb. SOC. Japan, 1922,37 Ann. Report, 1922, 19, 278.38 h ' u t t t w , 1.924, 113, 457; A., ii, 296; Proc. Physical Xoc., 1924, 36, 417.43, 761SUB -ATOMIC PHENOMENA AND RADIOACTIVITY. 247difference in numbers and in range of the dislodged protons betweenelements of even and those of odd atomic number. This differenceis reflected throughout the whole list of elements, not only in theirrelative abundance in nature, but also in their isotopic constitu-tion, and is doubtless a fundamental one in connexion with nuclearstructure and stability.G. Kirsch and H.Petterss0n,3~ working a t the Radium Institute,Vienna, have published results on disintegration by wparticleswidely different from those summarised above. Using Ruther-ford’s original method, they claim to have disintegrated carbonand oxygen and also to have obtained large effects from beryllium.Time will show if these claims can be substantiated, but in themeanwhile, when it is remembered that the technique of thescintillation method is one full of pitfalls only to be avoided byyears of research, the balance of the evidence is overwhelminglyon the side of the more experienced investigators.A wonderful verification of Rutherford’s original discovery ofthe disintegration of the nitrogen atom by the impact of a swifta-particle has been obtained quite recently in the CavendishLaboratory by P.M. S. Blackett,40 who has taken actual photo-graphs, by the Wilson fog-track method, of no fewer than sevenof these occurrences. To get these, it was necessary to photo-graph more than 400,000 a-ray tracks, the probability workingout about the same as that estimated by Rutherford. A largenumber of close nuclear encounters, indicated by widely forkedtracks, were picked out and measured. Of these, eight onlydisobeyed the ordinary collision laws and were undoubtedly dueto actual disintegrations. I n all these the track of the swift protondislodged is present both in form and quality exactly as expected,but, contrary to most expectations, there are only two branchesto the fork.This shows that the colliding or-particle does notrebound along a separate track, but, after impact, is retained bythe disintegrating nucleus, a t least for the rest of its passage throughthe gas of the expansion chamber. The nitrogen nucleus will havelost a charge + 1 and a mass 1 and will have gained a charge $- 2and a mass 4, so that the substance formed would appear to bean isotope of oxygen of mass 17. There is no evidence of such asubstance, so that it is either unstable or produced in nature inquantities too small to be detected. Previous to Blackett’s experi-ments, Harkins 41 published a Wilson track photograph showing39 Nature, 1924, 113, 603; A., ii, 380.40 Proc.Roy. SOC., 1925, [ A ] , 107, 349.4 1 W. D. Harkins and R. W. Ryan, Nature, 1023, 112, 64; a., 1023,ii, 601; J . Amer. Chern. SOC., 1923, 45, 2095; A., 1923, ii, 720248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.a fork with three branches which he claimed must therefore bethat of a disintegration. This claim was doubtful from the first,since the fork occurred too near the end of the range of the a-particlefor its energy to be adequate to effect disintegration. The trackbears no resemblance to those obtained by Blackett and is mostprobably due to the effect of radioactive contamination accidentallysuperposed on an ordinary forked collision track.A. Piutti 42 has made numerous experiments to find if any form-ation of helium or neon takes place in the discharge throughhydrogen.KO trace of either was found. S. K. Allison andW. D. Harkins43 have repeated the experiments of Wendt andIrion44 with the greatest care. Tungsten and platinum wireswere repeatedly exploded by discharges from a powerful condenserof 0.5 of a microfarad capacity charged to 42,000 volts. A con-denser discharge of potential 84,000 volts was passed hundreds oftimes through mercury vapour a t 0.1 mm. pressure and also throughhydrogen a t 40 mm. pressure. No trace of helium was found inany of these experiments, although a method capable of detecting2 x 10-1O g. was employed.The sensational report 45 that mercury had been transmutedinto gold in an ordinary mercury vapour lamp still lacks confirm-ation.It has, however, been supported46 on the ground thatthe transmutation only requires the addition of one electron tothe mercury nucleus, and since the field near the positively chargednucleus would be one of attraction, not of repulsion, as in the caseof an approaching a-particle, this operation might require verylittle energy. Against this view it may be argued, unless ourpresent ideas of matter are fundamentally a t fault, that Naturehas provided a mechanism, admittedly unknown to us but certainlyextremely difficult to evade, which effectually prevents positivelycharged nuclei absorbing casual electrons driven in their direction.Otherwise matter could not exist a t all. The experiments ofRutherford leave no doubt that just as the dimensions of thenucleus of an atom are almost inconceivably small-the radius ofthat of aluminium is probably less than 4 x cm.-so theforces binding together its component parts are gigantic and tobe measured in millions of volts.Until the progress of electricalengineering makes such potentials technically available in thelaboratory, it seems unlikely that transmutation of elements ona chemical, as opposed to the radioactive, scale will be possible.42 2. Elektrochem., 1922, 28, 452; A., 1923, ii, 20.43 J . Amer. Chem. SOC., 1924, 46, 814; A., ii, 407.44 Ann. Report, 1922, 19, 280.45 A. Miethe, Natumiss., July 18, 1924.46 F. Soddy, Nature, 1924, 114, 244; A., ii, 684SUB-ATOMIC PHENOMENA AND RADIOACTIVITY.249Long-range Particles from Radioactive Sources.The emission of particles of abnormal range was first observedin the case of radium-C by Rutherford in 1919. A similar pheno-menon was found to be exhibited by th0ri~m-C.~' This work hasbeen repeated, and extended to actinium and polonium activedeposits by L. F. Bates and J. S. Rogers,48 using a scintillationmethod. Their results may be tabulated as follows; the rangesare calculated for air under standard conditions and the numbersof the long-range particles are calculated relative to the totalnumber of normal a-particles emitted.6.978.63.931071061079.311.56.13 SO2209111.112615.04710.05113.2G718.45513.126In addition, actinium deposit was found to emit particles ofrange 6-49 cm., previously recorded by E.Maraden and P. B.Perkins,49 to the extent of 0.322% of its total a-rays. The workof Bates and Rogers on radium active deposit was adverselycriticised by G. Kirsch and H. PetterssonY5O who state that noparticles are emitted from this substance of range greater than7.5 cm. In consequence of its importance in connexion with theirwork on disintegration, Rutherford and Chadwick 5 1 have reviewedthe case of radium active deposit and reinvestigated it exhaustivelyby a great variety of experiments intended to eliminate any possibleflaws in the evidence. They have varied the preparation of thesource, examined the particles in a great variety of gases, eliminatedthe possibility of holes in the screens by replacing these with aheavy gas such as xenon, and finally have determined the massand velocity of the particles themselves by direct measurementof their deflection in a magnetic field.From the evidence soobtained, they conclude definit'ely that the long-range particlesare a-particles of mass 4 and that their origin is in the source itselfand not in the surrounding material, They estimate the numberof long-range particles emitted by 1 mg. of radium4 as about1050 of range 9.3 cm. and 180 of range 11.3 cm., numbers cor-responding to 309 and 53, respectively, on the scale of Bates and47 Ann, Report, 1922, 19, 286.4t3 Nntwe, 1923, 112, 435; rl., 1923, ii, 720; Proc. Roy. SOC., 1924, [ A ] ,105, 97, 360; A., ii, 84, 296.49 A., 1914, ii, 410.61 Phil. Mag., 1924, [vi], 38, 509.Nature, 1923, 112, 687; 1924, 113, 641; A , , 1923, ii, 819; 1924, ii, 380250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Rogers given above.They do not find any evidence of the particlesof range 1 3 4 claimed by Bates and Rogers.Radiations and the Xtructure of the Nucleus.X. Rosseland 52 suggests that the nuclei of radioactive elementsmay be intrinsically stable, but that their radioactivity is due tothe disturbing action of an external field of force originating in thesurrounding electrons. The orbits of these may approach veryclose to the nucleus in heavy elements. A rotation of the nucleusas a whole is postulated and it is pointed out that the frequency ofthis rotation may be comparable with some electronic frequencyand so give rise to destructive perturbations.Nuclear structureis also discussed by W. van der Berg 53 and M. C. N e ~ b e r g e r . ~ ~Fr. L. Meitner 55 has examined the P-ray magnetic spectrum ofuranium-X, and finds it to consist of three sharp lines and a faintband. From measurements of these, she concludes that theprimary P-rays are emitted from the nucleus with a definite velocity,which is in agreement with the suggestion of Rosseland 56 that anexcited atomic system can pass to an unexcited state by the emir-sion of one of its particles in the form of a corpuscular ray as analternative to the emission of radiation. In a later paper,57 shediscusses the work of Compton 5 8 and of Debye 59 on the scatteringof X - and 7-rays by matter as giving a possible explanation ofthe continuous p-ray spectrum.The alternative theory of Ellis, which is that the sharp lines ofthe magnetic spectrum are caused by the action of primary nuc1ea.r7-rays on electrons in different quantum levels outside the nucleus,and that the primary 7-ray may be caused by the passage of an@-particle from one quantum level to another in the nucleus, hasreceived much experimental support.Rutherford, in his dis-cussion on the nucleus of the atom,60 shows that it is in good accordwith his own conclusions that the a- and p-particles liberated fromelements of the type of radium-G and thorium-C may exist assatellites of a core or inner nucleus which is common to bothelements.61 C.D. Ellis and H. W. B. Skinner 62 have determinedthe absolute energies of the p-ray groups from radium-B and -C52 Nature, 1923, 111, 357; A., 1923, ii, 366.53 Chem. Weekblad, 1923, 20, 54; A., 1923, ii, 232.54 Ann, Physik, 1923, 68, 574; 70, 139; A., 1923, ii, 145, 400.5 5 Z. Physlsik, 1923, 17, 54; A., 1923, ii, 675.5 6 Ibid., 1923, 14, 173.5 7 L. Meitner, ibid., 1923, 19, 307; A., ii, 12.5 8 A., 1921, ii, 366.59 Physikal. Z., 1923, 24, 161.6O Roy. Inst., April 4, 1924. 61 F. W. Aston, Nature, 1924,113. 393.62 Proc. Roy. Soc., 1924, [ A ] , 105, 60, 165; A., ii, 85, 137SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 251correct to 1 in 500. The results for 47 lines are tabulated andconfirm the conclusion that the groups are due to the conversionof the 7-rays in the various electronic levels. Although the majorityof the p-ray lines from radium-B (atomic number 82) are due toconversion in atoms of this number, a group of lines of low energyhas been found to be due to conversion in atoms of atomic number 83.A more detailed study 63 of the frequencies of the y-rays confirmsthe original view that these are due to the transitions betweenstationary states in the nucleus itself , the evidence being stronglyin favour of the hypothesis that the dynamics of the nucleus canbe interpreted in terms of the quantum theory.In a later paper,64 Ellis describes an accurate redeterminationof the high energy groups of the magnetic p-ray spectlrum ofradium-C.He was able to account for all the p-ray lines as beingdue to quantum conversions in the electron structure.This resultis interesting, because the 7-rays concerned are of very high fre-quency corresponding to potential differences of 1.5 to 2 millionvolts. It is a striking thing that no fresh absorption phenomenaare found even with 7-rays of the highest frequency yet measured.A table of 11 y-rays is given and a set of nuclear levels suggested,transitions between which are supposed to be the cause of theseemissions. I n a series of papers,65 Thibaud describes experimentsleading to conclusions of the same general nature. He was notable to proceed to the detailed analysis of the spectrum, as sufficientlyaccurate measurements were not a t his disposal. He appears,however, to have improved the technique sufficiently to obtaindirect evidence of the photoelectric groups liberated by the veryhigh frequency y-rays from ordinary elements.The magnetic P-ray spectrum of mesothorium-2 has been studiedby D.Yovanovitch and J. ii'Espine,66 and later and more com-pletely by D. H. Black,67 who tabulates values of energies for31 lines. The grouping of these is in excellent agreement withthe theory of Ellis, but from the numerical results it is impossibleto decide with certainty whether 89 or 90 is the atomic numberconcerned in this case.Ranges of a-Rays.Continuing her work on the u-rays of polonium, Mlle Curie 6 8has now studied their ranges by direct photography of their tracksG3 Proc. Roy. SOC., 1924, [ A ] , 105, 185; A., ii, 137.64 Proc.Camb. Phil. SOC., 1924, 22, 369.6 5 Compt. rend., 1924, 178, 1706; 179, 165; A , , ii, 514, 717.6 7 Proc. Roy. SOC., 1924, [ A ] , 106, 632.6 8 Compt. rend., 1923, 176, 434; A., 1923, ii, 207.Ibid., 1924, 178, 1808; A., ii, 447252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in a Wilson expansion chamber. As the density of the gas in thechamber at the moment of emission cannot be stated precisely, themeasurements are essentially a comparison of the lengths of tracksobtained a t the same instant. Statistical curves connecting thenumber of the tracks and their lengths are given which show thatabout 90% of the rays have ranges between I - 1 and I + 1 rnm.,where Z is the most probable length, and also that it is possibleto define an extrapolated trajectory, p , in the same manner asHenderson defines it for the ionisation curve.69 The relationbetween these two lengths is p = I + 0.7 mrn., so that, takingGeiger's value for p 70 of 3.92 em., the most probable length oftrajectory will be 3-86 cm. in air a t 16" and 760 mm. The ionisingpower of an a-ray appears to increase a t first, pass a maximum4-3 mm. from its end, and then decrease rapidly during the lastfew millimetres. The ratio of the extrapolated ranges of radium-Cand polonium is given as 1.775 : 1, identical with that given byGeiger (Zoc. cit.).B. Gudden 7 1 has determined the ranges of uranium-I anduranium-I1 by measurement of the pleochroic haloes of fluorapar.These correspond to ranges in air of 2.68 and 2.76 cm., respectively.He calculates a new value for the radioactive constant for U-I1of 1.8 x 10-16sec:l, much smaller than that hitherto accepted,and concludes that the Geiger-Nuttall relation is not satisfied bythese bodies.The ranges of cc-particles in the inert gases have been measuredby L.F. Bates,72 using rays of a mean effective range of 4.15 cm.The mean pressures giving the same extrapolated range, and thecorresponding stopping powers are tabulated as follows :-Gas. Air. He. Ne. A. Kr. Xe.Mean pressure ......... 348.9 - 695.1 375.0 262.2 193.3Stopping power ...... 1 0.1757 0.586 0-930 1.330 1.804The stopping power of helium, which for an a-ray from radium-Cwould have a range of nearly 40 cm., had to be measured in aspecial apparatus.The value for the stopping power calculatedby the theory of Henderson 73 in every case but helium accountsfor 0.75 of that observed. It is suggested that the difference maybe due to multiple ionisation.Capture ayzd Loss of Electrons by cc-Particles.a-Particles are capable of capturing one or even two electronsduring their passage through matter and so becoming singly charged69 Phil. Mag., 1921, [vil, 42, 538; A., 1921, ii, 61'7.70 2. Physik, 1922, 45.7 1 Ibid., 1924, 26, 110; A., ii, 717.72 Proc. Roy. Soc., 1924, [AJ, 106, 622.73 Phil. Mag., 1922, [vi], 44, 680SUB-ATOMIC PHENOMENA AND RADIOACTIVITY, 253or neutral. G. H. Henderson 74 was able to photograph a banddue to singly charged particles half-way between the normal bandand the undeflected band in the magnetic spectrum of a-rays fromradon.The subject has been discussed by Bergen Davies 75and more completely studied by R ~ t h e r f o r d . ~ ~ The latter usedcc-rays from radium-B and -C in his experiments and counted theparticles, after magnetic deflection, by the scintillation method.The velocity of the a-particles is reduced by mica screens and theobservation consists in counting the number of singly chargedand neutral particles as the pressure is raised from a very lowvalue upward in the deflection apparatus. It is found that thenumbers fall off almost exponentially with the increase of pressure,and it can thence be deduced that for an a-particle of velocity0.85 x lo9 cm./sec. the mean value of the free path for loss of anelectron is 0.005 mm.and for capture 0.037 mm. in air a t N.T.P.The ratio of the mean free path for capture to that for loss variesas V4.6, where V is the velocity of the particle. A complete statis-tical theory for these phenomena has been worked out by R. H.Fowler. 77Kndioactice Constants.The number of a-particles emitted by 1 g. of radium withoutdisintegration products has been carefully redetermined byH. Geiger and A. Werner,78 using a scintillation method designedto eliminate error as far as possible. They obtain a value3.40 x lolo, which is compared with Rutherford and Geiger'svalue, 3-57 x lolo, and Hess and Lawson's value of 3.72 x 1010,and the reasons for the discrepancy are discussed. Using theirown value, and Millikan's figure for the charge on the electron,the half-period of radium is calculated to 1730 years and the evolu-tion of helium to 159 cu.mm. per year per gram of radium inequilibrium with radon, radium-A, and radium-C'. The heatevolved from 1 g. of radium without disintegration products iscalculated as 22.25 cal./hour. Comparing this value with theexperimental values 25.2 and 25.1 obtained by Rutherford andHWS, respectively, it appears likely that in radioactive changes ofthe radium atom,' in addition to the kinetic energy of the a-particlesand recoil atoms, other quantities of energy must be set free inconsequence of the changes in the atomic nucleus. This work iscriticised unfavourably by V. F. Hess and R. W.Lawson.7974 Proc. Roy. SOC., 1923, [ A ] , 102, 496.7 5 Nature, 1923, 111, 706; A , , 1023, ii, 453.7 6 Phil. Mug., 1920, [vi], 47, 277; A., ii, 225.7 7 Proc. Camb. Phil. SOC., 1924, 22, 253.78 2. Phyailc, 1924,21,187; A,, ii, 226. 70 Ibid., 1924,24,401; A.,ii, 58254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The constant of polonium has been measured by Mlle St. Mara-cineanuYso who obtains a value 139.5 days for the half-changeperiod, the radioactive constant X being 4.96 xThe period of protoactinium has been det,ermined by J. H.Mennie 81 by the comparison of the a-ray activities of ionium andprotoactinium separated from several kilograms of uranyl nitrate.He finds the average life period to be 18,000 years in agreementwith the period of half-change, 12,500 years, found by Hahn andMeitner.82J. C. Jacobsen,s3 by observing the scintillations from a pre-paration of pure radium-C', finds a value for its transformationconstant h of 8.4 x 105 sec.-l, a value widely different from thatcalculated by the Geiger and Nuttall relation.The radioactive constant of radon has been determined by anentirely new met'hod by Mlles I. Curie a'nd (2. Chamie,84 who givea value 3.823 & 0,002 days. This is compared with the earliervalues of Mme Curie and Rutherford, 3.85 days, and the recentdetermination by Bothe and Leechner, 3.810 days.(day)-l.AbsorptioTb and Skattering of 7-Rays.The absorption of the penetrating y-radiation from radium-Band -C by a number of different metals has been measured byN.Ahmad,s5 who finds that it can be expressed by the formula1.68 x lO-Z5Z + 1.60 x 10'31Z4, where 2 is the atomic number.Slight deviations occur after copper and mercury. Comparisonwith the corresponding formula for X-ray absorption suggests thatthe f i s t term represents an apparent absorption due to scattering,whilst the second term represents a true absorption. Two inde-pendent calculations are made of the effective mean wave-lengthof the hard y-rays. These give values 0.015 A. and 0.019 8. ingood agreement with the determinations made by Ellis.s6In a later paper 8' the results are discussed mathematically withspecial reference to apparent absorption due to scattering. It isfound that the total absorption may be represented by the formula0 .2 9 ~ ~ 2 + 2.29 x 10-2h3Z4, where a. is the scattering per electroncalculated on the classical theory, 2 is the atomic number, and Ais the mean effective wave-length, taken a.s 0.019B. as an upper80 Cosnpt. rend., 1923, 176, 1879; A., 1923, ii, 529.81 Phil. Mag., 1923, [vi], 46, 675; A., 1923, ii, 719.82 Ber., 1921, 54, [B], 69; A., 1921, ii, 150.83 Phil. Mag., 1924, [vi], 47, 23; A,, ii, 142.8s Compt. rend., 1924, 178, 1808; A., ii, 447.8 5 Yroc. Roy. SOC., 1924, [ A ] , 105, 507; A., ii, 440.86 Ibid., 1922, [ A ] , 101, 1 ; A., 1922, ii, 339.97 N. Ahmad and E. C. Stoner, &id., 1924, [ A ] , 106, 8; A., ii, 582SUB -ATOMIC PHENOMENA AND RADIOACTIVITY. 255limit. The scattering per electron is approximately constant overa large angle and is therefore independent of the position andbinding of the electron.These results agree qualitatively, but notquantitatively, with Compton’s formula. I n a more recent paper,ssOwen describes similar measurements, but not only does he measurethe total absorption (scattering plus energy absorption) but by aspecial experimental arrangement he was able to measure the trueenergy absorption independently of that due to scattering. Hefinds the true energy absorption to consist of the sum of twoterms, one varying as Z4 and the other as 2. It is interesting tonote that Compton’s theory suggests just such a variation.Another interesting observation connected with the mechanismof scattering has been made by D. S k o b e l ~ y n , ~ ~ who has examinedthe tracks of electrons liberated by y-rays in a Wilson cloud chamber.He finds that these have velocities corresponding with ranges ofabout 1 cm.These velocities are much less than those which anelectron should attain by the absorption of a complete quantumof the y-radiation. The directions of motion of the electrons donot in general coincide with the path of the incident 7-rays. Theobservation is in favour of the Debye-Compton theory of scatter-ing; on the basis of this, it can be explained as a recoil effect,the scattered radiation not being in the form of a sphericalwave.Number of y-Rays emitted from Radium-B and -C.-A. F. Kovarikhas redetermined the total number of 7-rays emitted per secondfrom radium-B and -C in equilibrium with 1 g.of radium. Thishe gives as 7.28 x 1O1O & 0.3%. Each radioactive transformationresults in the emission of one y-ray entity, which produces a P-rayemission from a single atom. The utmost confidence may beplaced in the results of this admirable piece of work. I n it theauthor redetermined every constant used in his calculations, except -ing the coefficient of absorption in air, and allowed for every possiblecorrection likely to affect the result.Uranium and its Ilelations to Other Elements.The discovery of uranium-2 by Hahn was mentioned in theprevious report. A further account of this substance is given byits discoverer,gl in which a method is described for the determinationof the relation of the activity of uranium-2 to that of uranium-X.8 8 E.A. Owen, N. Fleming, and W. E. I:age, PYOC. Physical. SOC., 1924,36, 355.2. Physik, 1924, 24, 393; A., ii, 582.so Physical Rev., 1924, 23, 559; A., ii, 447.*l 0. Hahn, 2. physikal. Chem., 1923, 103, 461; A., 1923, ii, 11256 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.This method he has applied to a large number of uranium-X prepar-ations of different ages and has obtained a satisfactory constantvalue for the relationship. The constancy of the value allowsit to be concluded that uranium-X, is the parent substance ofuranium-2. Uranium-X,, therefore, undergoes adual p-ray disintegration of a kind which has UIUXi hitherto not been observed with radioactiveelements. A new method of detecting uranium-2UX2<: :)UZ is described and from the activity ratio ura-nium-2: uranium-X it is shown that thebranching relationship is about 0.35%.Themost probable disintegration scheme is as shownin the annexed diagram.He determines theperiods of uranium-Y, uranium-2, and uranium-& to be 25.5hours, 6-69 hours, and 70.5 seconds, respectively, and points outthat the branching ratio given by Hahn is approximately equal tothe reciprocal of the periods of the two substances formed, namely,uranium-X, and uranium-2. W. P. Widdowson and A. S. Russell 93have carefully repeated the work of Boltwood 94 on the relativeactivities of the radioactive constituents of an unchanged primaryuranium mineral (pitchblende). The results indicate, as before,the lowness of the relative activity of the mineral to that of itsuranium content, but the new values of the relative activities ofpolonium, ionium, radium, and uranium are not the same as thosepreviously obtained and now agree closely with those deducedtheoretically.I n two papers on the radioactive disintegrationseries, Russell concludes that these are limited to four in number,the members of which have atomic weights given respectively by4n + 3, 4n + 2, 4n + 1, and 4n, where n is an integer. He givesreasons for supposing that the first of these is the actinium series,the second the uranium series, the third a hypothetical series the endproducts of which may be isotopes of bismuth and of thallium, and thefourth the thorium series. The first of the papers 95 is principallyconcerned with the origin of actinium.From the considerationof simple empirical relations holding among the known radioactiveseries, he draws the conclusion that actinium arises from an isotopeof uranium with an atomic weight 239 present to the extent ofabout 5%. The disintegration of this is summed up in the followingtable :-I99.65 "/,/\0'35 %\/y11A. S. Russell 92 confirms Hahn's conclusions.#a Nature, 1923, 111, 703; A., 1923, ii, 497.93 Phil. Ma.g., 1923, [vi], 46, 915; A., 1923, ii, 819.94 Amer. J. Sci., 1908, [iv], 25, 269; A., 1908, ii, 454.95 A. S. Russell, Phil. Mag., 1924, [vi], 46, 642SUB-ATOMIC PHENOMENA AND RADIOACTIVITY. 257Position. Element.(1) Actinouranium-I ......(2) Uranium- Y ............(3) Uranium- Y, ............(4) Actinouranium-I1 ......(5) Parent of protoactinium(6) Protoactiniwn ............(7) Actinium ..................(8) Radioactinium .........Period.ca.8 x log years28 hoursca. 1 minute2 x loe years20 years1.2 x lo4 years20 years19.5 daysz. Radiation. a.92 U 239235 ' 23590919223 1 ! 2319091227 ! 2278990! 235I n the second paper,96 the possibilities of the hypothetical thirdseries are investigated. A large number of experiments werecarried out with pitchblende, thorianite, and a preparation ofradium in search for the hypothetical isotope of radon, thoron andactinon expelling a-particles and having an anticipated period of70 minutes. These were completely unsuccessful.It is shownto be theoretically probable that there are only three out of thefour possible radioactive series which have members of atomicnumber 86 emitting a-particles. The fourth, if it exists, shouldarise from an isotope of protoactinium having an atomic weightof 233, pass through the missing elements 87 and 85, and end inbismuth. The relation between uranium and radium is furtherdiscussed by S ~ d d y , ~ ' who has redetermined the average life periodof ionium, from the rate of growth of radium in uranium prepar-ations, as 1-08 x 105 years, a value 8% higher than that obtainedbef0re.~8 Examination of two specimens of ionium-thorium separ-ated from different products from Joachimsthal pitchblende showedan ionium-thorium ratio of 1 : 0.9 in agreement with the latestvalue given by Meyer and U l r i ~ h . ~ ~Radioactivity of the Alkali Metals.The feeble py-radioactivity of the alkali metals has been studiedby G. Hoffmann.1 He describes two very sensitive methods. I nthe first, the disturbance due to a-radiation is avoided by placingthe ionisation chamber a t a sufficient distance from the substance.The second method is for use when there are no a-rays or so fewthat the py-radiation can be measured between these occurrenceswith sufficient accuracy. These methods have been applied tothe alkali metals with results in good agreement with those obtainedpreviously by Hahn and Rothenbach.2 The activities of sodiumW. P. Widdowson and A. S. Russell, ibid., 1924, [vi], 48, 293; A.,97 F. Soddy and A. F. R. Hitchens, ibid., 1924, [vi], 47, 1148; A., ii, 446.9 8 Soddy, ibid., 1919, [vi], 38, 483; A . , 1919, ii, 443.ii, 649.Sitzungsber. Akad. Wiss. Wien, 1923, 132, 279.1 Physikal. Z., 1923, 24, 475; A., ii, 86; 2. Physik, 1924, 25, 117; A.,* Physikal. Z., 1919, 20, 194; A., 1919, ii, 312.ii, 718.TLEP.-VOL. XXI. 258 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and caesium are found to be negligible. The ratio of the py-activitiesof potassium and rubidium is found by the first method to be1 : 4, by the second to be 1 : 7.6. The ratio of the By-activity ofpotassium to that of uranium is given as 1 : 460. These feebleradioactivities are particularly interesting in connexion with theisotopic constitutions of the alkali metals. Their complete absencein the two simple ones appears significant. The activity in potassiumand rubidium may be general or confined to one of their known iso-topes, or alternatively it may be entirely due to the presence ofminute traces of unknown radioactive isotopes. It is worth notingthat the ratio of activity given above is about the same as the ratioof the percentage of the less abundant isotopes, K41 and Rbs7, inthese two elements.F. W. ASTON

ISSN:0365-6217    

DOI:10.1039/AR9242100238

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

COLLOID CHEMISTRY.*THEORETICAL papers on the colloidal state have appeared by severalauthors. P. Bary 1 discusses the two schools of thought : the‘ physical ’ theory of colloids, and the ‘ chemical ’ theory. On theone hand, colloidal properties are considered to arise within a certainrange of dispersion, i,e., colloidality is merely a state of matter.Bary and the ‘ chemical ’ school would term colloidal those sub-stances which readily polymerise, swell in certain liquids, areamorphous, and exhibit somewhat vague chemical reactions.P. P. de Weimam2 gives a review of his work under the title“ Some Fundamental Principles of my Theory of the ColloidalState.” This is simply a summary of his well-known views oncolloidal dispersion, and his laws of corresponding states.Hebelieves that “ all those physical and chemical properties whichone specifically associates with colloidal substances, appear spon-taneously for each solid substance on progressive dispersion to therequisite degree, no matter how the dispersed state is reached.”M. J. Duclaux 3 prefers a different view from that of de Weimarn :“true colloids are distinguished by the fact that their moleculescan assume considerable dimensions by simply calling into playprincipal valencies.Reviewing his work on sulphur sols (A., 1914, ii, 35; 1915, ii,97, 152 ; 1922, ii, 485 ; 1924, ii, 330), G. Rossi 4 discusses the colloidstate, giving a theory as to the origin of suspensoids and emulsoids,and why a given substance may form a colloid in one solvent and a,true solution in another.He believes that colloidal dispersionis maintained by other forces than that of the simple affinity ofthe solvent for the solute. For colloidal suspensoid systems, suchaffinity is slight, if any, and electric charges play the dominant dZe.For emulsoid systems, the solvent promotes dispersion and stabilityto a certain extent, the electric charge assisting stability.* This Report has been prepared on behalf of the British Association Com-mittee on Colloid Chemistry (Prof. F. G. Donnan, Chairman ; Dr. W. Clayton,Secretary; Mr. E. Hatschek; Prof. J. W. McBain; Prof. W. C. McC. Lewis)by the Secretary. The section on gels and Liesegang phenomena is con-tributed by Mr. Emil Hatschek.Rev. gdn. Coll., 1924, 2, 33; A., ii, 239.Ibid., pp.193, 225; vide also Bull. SOC. chim., 1924, [v], 35, 630.Rev. gdn. CoU., 1924, 2, 251.They can condense, but crystalloids cannot.”Gazzetta, 1924, 54, 221; A., ii, 459.269 K 260 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The work of W. Pauli and his collaborators since 1917 on thestructure of colloids has been reviewed in detail by him.5An interesting paper on the theory of colloid phenomena hasappeared by U. R. Evans and L. L. Bircumshaw,6 who point outthat forces of electrical origin exist a t the interface : colloid-liquidmedium. I n addition to interfacial tension acting along the inter-face, there are forces acting across the interface, i.e., perpendicularto the boundary. Such " adhesive forces " binding the colloid andmedium together are high when the interfacial tension is low andvice versa. At or near the isoelectric point, where interfacial tensionis a maximum, the adhesive forces are a minimum, so that stability,peptisation, and swelling are a t a minimum too.The Brownian movement of the same particles a t various pressureshas been investigated by S.Landrna,n,' who finds more activemotion as the pressure decreases. The ageing of colloidal solutionsis discussed by H. Gessner,* who worked with vanadium pentoxidesols. His paper is too long for adequate summary here. Theinfluence of colloids on the rate of reactions involving gases has beenfurther studied by A. Findlay and W. tho ma^.^ They used solsof gelatin, starch, dextrin, albumin, and peptone as the colloidsand the reactions chosen were the decomposition of hydrogen peroxideby fuller's earth, of nitrosotriacetonamine in the presence of hydroxylion, and of hydrogen peroxide in presence of iodide ion.The possibility of a connexion between the protective effectof gelatin and other ' schutz ' colloids and their elastic propertiesis mooted by H.Freundlich and J. F. Loeb.l0 The propertiesof the colloids sodium stearate and sodium oleate support thatview.A capillary viscosimeter has been described by W. Ostwaldllwhich permits definite values for the viscosity of colloidal solutions.Using the Hess and Couette viscosimeters, H. Freundlich and E.Schalek found that sols of AsZ&, ZrO,, CaF,, and S obeyedPoiseuille's law, but sols exhibiting a marked elasticity showed widedeviations from this law.As example, sodium stearate in 0.1%solution showed marked elasticity and did not obey Poiseuille'slaw, whilst sodium oleate up to 40% solution showed no elasticityand obeyed Poiseuille's law. The theory of the elasticity of colloidalsolutions is worked out by A. Szegvari.13The Mie-effect (Ann. Physik, 1908, [iv], 25, 37) has been studied6 Natumhs., 1924, 12, 421.6 Kolloid. Z., 1924, 34, 65; A., ii, 236. 2. Physib, 1924, $37, 237.8 Koll. Chem. Beihefte, 1924, 19, 213; A., ii, 741.a J., 1924, 125, 1244.' 0 Kolloid-Z., 1924, 34, 230.l2 Ibid., 108, 153.*l Z. physikal. Chem., 1924, 111, 62.l3 Ibid., 108, 175COLLOID CHEMISTRY. 261by Szegvari l4 and by A. Ehringhaus and R.Wintgen.15 The Mie-effect is the name given to the phenomenon shown when a particlethe diameter of which is less than half a light-wave length is illu-minated by a beam of light, The light is scattered in all directions,with the greatest intensity in the direction of the primary beam,this being more pronounced as the particle size increases. Szegvaridescribes ultramicroscopical investigations with unidirectionalillumination, whilst Ehringhaus and Wintgen confirm Mie's theoryby a photometric estimation of the absorption of monochromaticlight illuminating gold suspensions in fused borax.C. Wha 1 6 has detailed the technique of ultrafiltration anddescribed a vacuum dialyser made of collodion. The questionwhether the membranes used in ultrafiltration operate as sieves orby virtue of solubility differences has been raised by J.Duclauxand J. Errera,l' who carried out an extensive study of the mechanismof ultrafiltration. They conclude that the velocity of filtration is,within a few units per cent., inversely proportional to the viscosityof the liquid and directly proportional to the pressure. Slightvariations from this rule may be caused by deformation of themembrane under pressure, swelling of the membrane itself, and byan ' E.M.F. of filtration,' this disappearing with a conducting liquidno matter what the p~ value. The membrane behaves like a bundleof rigid capillary tubes. Solvation, surface tension, the p H ofthe liquid, and the osmotic pressure have only a slight influence onthe membrane.This may not be true, however, for membranes ofa finer structure, i . e . , lesser porosity.A new ultrafiltration apparatus has been described by H. Becholdand L. Gutlohn,18 whilst J. A. Pickard l9 has given details of theso-called " stream-line filter " and discussed its application forclarifying spent lubricating oil, varnishes, fixed oils, gums, and glues.Electrodialysis is treated by H. Freuncllich and L. F. Loeb.20Under cataphoresis must be mentioned an important paper byL. Michaelis and A. Domboviceanu,2l who measured the cataphoresisof mastic sols. The relation between the cataphoretic velocityand variations in the electrical properties of the double layer sur-rounding the particles was investigated, the adsorbed kations beingkept all of one kind, vix., by using hydrogen ion as the adsorbedl4 Z.Physik, 1924, 21, 348; A., ii, 315.l5 Z. physilcal. Chem., 1924, 108, 406; A., ii, 396.l6 Biochem. Z., 1924, 144, 278; A., i, 458.l7 Rev. gLn. Coll., 1924, 2, 130.l9 J . Oil and Colour Chem. Asaoc., 1921, 7, 110.*O Biochem. Z., 1924, 150, 522.21 Kolloid-Z., 1924, 34, 322; A., ii, 738.2. angew. Chem., 1924, 37, 494262 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.kation. The essential fact was established that the cataphroeticvelocity increases as t h e m value rises, but by no means to the sameextent as would be expected if the cataphoretic potential dependedon the pHvalue as does the potential of the hydrogen electrode.The potential difference associated with electrokinetic phenomenain colloid systems is not comparable with the Nernst potentialdifference, e.g., as applied to the pole of a galvanic circuit.Adsorption and cataphoresis experiments with suspensions ofglass and with selenium sols have been published by K.von derGrinten,22 whose results correspond with the maximum adsorptionas a unimolecular film on the particles.Particle Sixe.E. F. Burton and J. E. Currie,= continuing the work of Burtonand Bishop (Proc. Roy. SOC., 1922, [A], 100, 414) and using sols ofgamboge, arsenious sulphide, copper, and silver, conclude that theparticles are uniformly distributed in these colloidal solutions. Theuniform distribution is probably due to the electrical charges on theparticles.The question of the percentage distribution of particles of definitesize in a colloid sol or coarse suspension is very much to the forejust now.C. A. Klein and J. Parrish 24 have published a detailedreport of their work on size analysis, with special reference topigments. Various methods are reviewed and their own elutriationmethod is given fully. An extension of the O d h recording balancehas been developed at the Rothamsted lab~ratories.~~ The newapparatus is an automatic self -recording balance controlled electro-magnetically, and can be used with no loss of sensitivity up tothe maximum load the balance is designed to carry. Further, thesensitivity can be very simply adjusted, so that both rapid and slowchanges of weight can be recorded.The Ostwald-von Hahn ‘ flocculation meter ’ (KoZZoid-Z., 1923, 32,60) has been modified by W.J. Kelly,26 for determining the distribu-tion of particle size in suspensions. Presupposing the validity ofStokes’s law for the rate of settling, the method consists in followingthe change in hydrostatic balance when the suspension is balancedagainst the dispersion medium in a U4ube apparatus. The sameapparatus has been modified by E. 0. Kraemer and A. J. Stamm 2722 Compt. rend., 1924, 178, 2083; A., ii, 664.23 Phil. Mag., 1924, [vi], 47, 721; A., ii, 459.24 J. OiE and Colour Chem. ASSOC., 1924, 45, 54.25 J. R. H. Coutts, E. M. Crowther, B. A. Keen, and S. Odh, Proc. Roy.16 J . Ind. Eng. Chem., 1924, 16, 928.2 7 J. Amer. Chem. SOC., 1924, 46, 2700.Soc., 1924, [ A ] , 106, 33COLLOID CHEMISTRY.263to determine the distribution of size of particles in emulsions. Theirwork is important, as very few studies have been made on the size-analysis in liquid-liquid systems, and a promising line of research isopened up.M. Mason and W. Weaver 28 have published a mathematical paperon the settling of small particles in a fluid. The outstanding work,however, on this subject is the elaboration of the ultra-centrifugeby The Svedberg and H. Rinde.z9 A specially designed centrifugeenables the changes taking place in a fine-grained sol during centri-fuging to be followed photographically or directly by telescope andscale. The mathematical theory underlying this method has beenfurther developed.Thus Stokes's law is modified for the influenceof variation of acceleration with distance from the axis of rotation,whilst the theory is given for the determination of distributionof particle size. Results of measurements of size and distributionof size of particle for gold sols of average radius 2.3, 3.6, 7.1, 1 1 . 6 ~ ~are given and the nature of the protective action of gelatin uponfine-grained gold sols has been studied. As an instrument ofresearch the ultra-centrifuge promises a brilliant future.In connexion with particle size attention may be directed toW. D. Bancroft's30 work on the colour of colloids and the pro-duction of Tyndall-blue in solids, and to H. Remy's 31 investigationon the particle size of chemical fumes.The presence of colloids in solutions which give precipitateson interaction causes smaller particles to be formed. W.G. Franceand D. McBurney 32 find that as little as 0.013% of gelatin reducesthe average size of the particles of basic lead carbonate to approx-imately one-third the normal size, when sodium carbonate andsodium chlorate together in water are electrolysed between leadelectrodes a t 20" whilst carbon dioxide is bubbled near the anode.F. J. Brinley 33 reports the similar observation that colloidal arsenateof lead is prepared when lead nitrate and disodium arsenate reactin the presence of gelatin and other colloids.Sols.The well-known work of Svedberg on the formation of colloidsby electrical methods is extended by him in collaboration withE.0. Kra~!mer.~~ Previous work on the electrical pulverisation ofmetals in the high-frequency arc suffered from the defect that the29 J . Amer. Chem. Soc., 1924, 46, 2677. 28 Physical Rev., 1924, 23, 412.30 J . Physical Chem., 1924, 28, 12.32 J . Amer. Chem. Soc., 1924, 46, 540; A,, ii, 314.33 J . Agric. Research, 1924, 26, 373.2. anorg. Chem., 1924, 138, 167.J . Amer. Chem. SOC., 1924, 46, 1980; vide also R. Fiirth, Kolloid-2..1924, 34, 224; A., ii, 533264 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.generation of the high-frequency oscillations is disturbed andmodified by the pulverisation process which takes place in thesame circuit and across the same spark gap. Now by the use of alow-voltage type of Tesla coil (which separates these two processes)as a source of damped high-frequency oscillations, cadmium hasbeen dispersed in water, alcohol, and ether, giving much purer sols.Rates of pulverisation, sediment formation, and decomposition ofthe medium were investigated.The authors also discuss thepossible causes underlying the various behaviours of the differentelectrical circuits, laying stress on the influence of the character ofthe condenser discharge upon the pulverisation process.The formation of colloids in the electrolysis of dilute solutionshas been studied by P. N. Pav10v.~~ With silver thread electrodes1-2 mm. apart in water, and a low voltage (2 volts), colouredstreams of strong polarity are evidenced, yellowish-green a t thecathode and red a t the anode.Sols were similarly obtained with iron,gold, and bismuth electrodes, also with copper electrodes in verydilute copper sulphate solution.Detailed experiments along similar lines have been carried outby V. K~hlschutter,~~ who made ultramicroscopic observations onthe processes which occur at the electrodes during electrolysis,whilst F. Thoren3' has worked on the electrolytic precipitation ofnickel in disperse form from an ammoniacal solution of nickelnitrate. He obtained particles about 0.3 to 0*25p, and apparentlythey were non-crystalline.Colloidal gold has been prepared by heating a solution of goldchloride with formaldehyde, neutrality being carefully maintainedduring the process.38 P. A. Thiessen39 has shown that the redhydrosol of gold prepared by the formaldehyde reduction of alkalinegold solutions consists of pure metal ultramicrons free from oxidationproducts. Partial reduction leading to a blue sol results in ultra-microns of gold and gold oxide.Thiessen cannot substantiatePauli ( A . , 1921, ii, 246) that compounds between gold and waterexist in the coagula of these sols. Thiessen 40 has also investigatedthe sensitivity of phosphor-gold hydrosol (Au,) to ammonia, andshown it to be due to the presence of unreduced gold compounds inthe sol.Using a highly purified gold sol, M. Adolf and W. Pauli's experi-ments 4 1 led to the calculation that the sol contained particles of3 5 J . Amer. Chem. SOC., 1924, 46, 100; A., ii, 236.313 Z . Elektrochem., 1924, 30, 164; A., ii, 538.38 F.T. Grey, Biochem. J., 1924, 18, 448; A., ii, 460."9 2. anorg. Chem., 1924, 134, 393; A., ii, 691.40 LOG. cit., p. 357: A., ii. 691.41 Kolloid-Z., 1924, 34, 29; A., ii, 311.37 Ibid., p. 2COLLOID CHEMISTRY. 265an average size 27pp (cube edge). From X-ray data of Scherer(Appendix to Zsigmondy‘s “ Kolloidchemie,” 4 Aufl., 406)) it iscalculated that each gold particle has 57,000 negative charges.W. Pauli42 and R. Zsigmondya have put forward argumentsrelating to the chemical composition of red gold sols, the formerasserting that the gold particles are enveloped with an ionogencomplex of a gold sol, whilst the latter believes that this ionogencomplex is merely adsorbed water.E. Erlachand W. Pauli44 determined the conditions of formation and thecomposition of the sols produced by Kohlschutter’s method ( A .,1908, ii, 182).The dialysed sols may contain up to 20% of silveroxide, which may be removed by reduction with hydrogen. Appar-ently between ten and thirty atoms of silver are associated withone electric charge.Impure silver sols of low concentration and little stability havebeen obtained by G. Rebi&re46 by grinding precipitated silverin water. Other methods were tried, but silver oxide particlesinvariably resulted as impurity. A detailed study of colloidalsilver with special reference to its therapeutic use has been publishedby H. S ~ h l e e . ~ ~ Medicinal uses of colloidal silver are also dealt withby J. R. Petroff 47 and by S u g a n ~ m a . ~ ~According to G.R o s s ~ , ~ ~ sulphur sols are stabilised by sulphuricacid and sodium sulphate. The quantity of coagula obtained fromdifferent sols containing the same percentage of sulphur but differentamounts of sulphuric acid and sodium sulphate is inversely propor-tional to the latter. The great significance of crystalloid stabilisersin colloidal solutions is emphasised.Colloidal selenium has been prepared by A. Gutbier 50 by reductionof selenium oxide with hydrazine hydrate, the stabiliser being adialysed extract of carob-beans. The sol is yellow to dark red,depending on the degree of reduction or concentration. Thestability is poor, and electrolytes coagulate the sol rapidly.A new method of preparing colloidal silicic acid has been elaboratedby R.Schwarzq51 Pure silicic acid gel is treated with 3N-5N-ammonia (100 C.C. of ammonia to 0.4 g . of SiO,) and allowed to stand100 hours. Filtration followed by ultrafiltration, and then desicc-ation in a vacuum over dilute sulphuric acid, gives a water-clearsol of high dispersity. Schwarz carried out precipitation experimentsSilver sols have been investigated by several workers.42 Microchemie, 1924, 2, 47.44 Kolloid-Z., 1924, 34, 213; A., ii, 532.4 5 Rev. gtn. Coll., 1924, 2, 105, 139; A., ii, 661.46 Biochem. Z., 1924, 148, 383; A., i, 1262.47 Z . ges. expt. Med., 1924, 42, 242. 46 Biochem. Z., 1924, 144, 141.48 Kolloid-Z., 1924, 34, 20. Ibid., p. 336; A., ii, 739. 51 Ibid., p, 23.43 Ibid., p. 50.K266 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with sols of iron and aluminium hydroxides, albumin, and humanserum. A paper on colloidal silica has also been published by F.Dibnert and F.Wandenbulcke.52Vanadium pentoxide sols have been prepared by A. V. D ~ m a n s k i , ~ ~employing Biltz’s method ( A . , 1904, ii, 324). The red sols werenegatively charged. Conductivity measurements were made undervarious conditions. Perfectly clear sols did not show the phenomenonof double refraction (Freundlich, A . , 1916, ii, 442), but it becamewell marked in turbid sols or gels. The dielectric constant ofvanadium pentoxide sol has been determined 64 for a wave-length of70 cm. and a 3 years’ old sol. Increase in concentration resulted inan enhanced dielectric constant, the converse being true for freshly-made sols.General agreement is found with the results of Errera( A , , 1922, ii, 694) for much longer wave-lengths.The constitution of arsenious sulphide sols has been studied byW. Pauli and A. Semler.55 The sols were prepared from solutionsof glassy arsenic trioxide with hydrogen sulphide and the latter wasremoved by bubbling hydrogen. Various experimental methodsled to a structure being proposed for the colloidal sulphide as(xAs,S,,As,S,H, - As,S,,H)H. A. Semler 56 extended this workto a consideration of the chemical behaviour and colours of theionogen complexes of arsenic sulphide sols. A theory is put forwardthat the sol is formed through the production and subsequentdecomposition of unstable thioarsenious acid.The conditionsgoverning the size of particles in arsenic sulphide sols made by theaction of hydrogen sulphide on solutions of arsenic trioxide havebeen investigated by methods involving the absorption spectraof the sols and their absorption coefficient for a definite wave-length. A. Boutaric and M. Vuillaume 57 thus find that increasein the particle size follows increased concentration of the arseniousoxide solutions, rise in temperature, excess of hydrogen sulphide,and the use of a slower current of this gas. Flocculation tests withelectrolytes were made in relation to particle size.The experiments of R. Wintgen and H. Lowenthal with chromicoxide SO IS,^^ confirmed the results of previous work with stannicoxide, ferric oxide, gelatin, and dyestuffs, that the micelle simulatesa multiply-charged ion.The preparation of nickel hydroxide gel by the action of N -alcoholic potassium hydroxide on a solution of nickel acetate in52 Compt.rend., 1924, 178, 564; A,, ii, 253.53 J . Russ. Phys. Chem. SOC., 1924, 54, 703; A., ii, 195.54 R. Fiirth and 0. Bliih, Kolloid-Z., 1924, 34, 259; A., ii, 729.55 Ibid., p. 145. 66 Ibid., p. 209; A., ii, 532.5 7 Compt. rend., 1924, 175, 938.5 8 2. physikal. Chem., 1924, 109, 378; A., ii, 634COLLOID CHEMISTRY. 267glycerol has been investigated by 0. F. Tower,59 who proved thecomposition to be Ni(OH),, not NiO or an intermediate hydrate.The constitution and stability of iron oxide sols have been furtherinvestigated,60 dialysis of ferric chloride being employed.Thegeneral formula of such a sol is [xFe(OH),,yFeOCl,FeO]Cl’. Pro-longed dialysis diminishes x, and the sol is less stable,Aluminium oxide gel has been prepared 61 as follows : 150 C.C.of O.1N-ammonia, ice-cold, were stirred by a stream of air saturatedwith ammonia, whilst 50 C.C. of 0-1N-aluminium chloride solutionwas added little by little. The fine-grained, milky precipitatewas dialysed for 50 hours, when the electrical conductivity wasconstant a t 9.88 x mho. Traces of ammonia peptised the gelcompletely to an unstable, water-clear, negative sol.The colloid chemistry of night-blue is dealt with by F. V. vonHahn,62 whilst H. Freundlich 63 deals with sols of pyrrole-red.Coagulation .Smoluchowski’s theory (A., 1917, ii, 297) of the coagulationof colloids has been investigated by L.Anderson 64 and by J. N.Mukherjee and S. K. M a j ~ m d a r . ~ ~ Anderson observed the rate ofcoagulation of gold sols by hydrochloric acid, potassium chloride,barium chloride, and aluminium chloride. I n agreement withprevious investigators, a region of rapid coagulation is found inwhich Smoluchowski’s equation holds fairly well. I n the case ofslow coagulation, as when using dilute solutions of electrolytes, theequation no longer holds. Anderson suggests this may be due to theinitial primary gold particles being unequally charged. Slow andeventually incomplete coagulation is due to the adsorption of smallamounts of electrolyte, and some of the more highly-chargedparticles may not adsorb sufficient electrolyte t o reduce the chargebelow the critical limit permitting of coagulation.Mukherjee and Majumdar studied the rates of coagulation ofarsenious sulphide sol in presence of inorganic salts.I n the regionof slow coagulation, Smoluchowski’s equation breaks down aftera certain stage of coalescence, and the coalescence stops a t a certainstage, depending on the rate of coagulation. The greater this rate,the more advanced is the limiting stage of coalescence. Nearthis stage and afterwards, Smoluchowski’s equation is completelyinvalid. It is suggested that coalescence is reversible or irreversible,according to the potential of the double layer, the limiting stage60 J . Physical Chern., 1924, 28, 176; A., ii, 237.60 W.Pauli and F. Rogan, Kolloid-Z., 1924, 35, 131; A., ii, 740.61 A. Lottermoser and F. Friedrich, Ber., 1924, 57, [B], 808.62 Kolloid-Z., 1924, 34, 162; A., ii, 311. Ibid., p. 257; A., ii, 739.64 Trans. Farachy Soc., 1924, 19, 623; A., ii, 531. 6 b J., 1924,125, 785.K* 268 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.resulting when there is an equilibrium between the rates of coagul-ation and the breaking up of the aggregates due to fluctuationsin thermal energy. (Smoluchowski’s theory and a full discussionof the precipitat’ion of suspensoids by electrolytes have been dealtwith by Mukherjee in a Thesis, Calcutta University Press, 1924.)Primarily to ascertain whether the “ activity ” of ions ratherthan their concentration plays the significant rble in electrolyticcoagulation of colloids, Anderson 66 investigated the eff ect ofsucrose on the rate of coagulation of gold sols by hydrochloricacid, potassium chloride, and barium chloride.Sucrose increasesthe “ activity ” of various ions whilst not appreciably altering theirconcentrations. The general conclusion was drawn that the coagul-ating power of an ion is dependent on its “ activity ” rather than onits concentration. Incidentally, it was found that siicrose exertsa definite peptising effect on colloidal gold.The kinetics of coagulation have also been studied by H. H. Paineand G. T. R. who followed the coagulation of colloidalcopper hydroxide by potassium sulphate. Freundlich’s extension( A . , 1919, ii, 53) of Smoluchowski’s theory led to an equation forthe rate of coagulation which required that, as the concentrationof the electrolyte increases, the rate of coagulation should approach acertain limiting value.The results of Paine and Evans agreeclosely with Freundlich’s equation and they confirm the existenceof a maximum rate of coagulation. On the experimental side, theinteresting feature of this work was the use of a protective colloid(soluble starch) to retard coagulation. Thus very rapid coagul-ations could be brought into the region of observation by ordinarymethods, whilst a “ transformation factor ” permitted the calculationof the rate of coagulation for the pure colloid.The mechanical condition of coagula has been investigated byS. S. Bhatnagar, K.K. Mathur, and D. L. Shrivastava.68 Usingsols with uniform particles obtained by ultrafiltration, they foundthe coagula also consisted of uniform particles. An elutriationmethod was employed to determine particle size, When the solswere coa,gulated by uni-, bi-, and ter-valent ions, respectively,the greatest elutriation velocities required to separate the particlesof final size from the coagula were approximately in the ratio1 : 2 : 3. This result favours the electrical adsorption theory ofcoagulation.have published the results of aninvestigation confirming and extending the well-known views of theJ. N. Mukherjee and B. C. Roy66 LOC. cit., p. 635; A., ii, 531.67 Trans. Faraohy Soc., 1924, 19, 649; A., ii, 531.G8 J. Physical Chem., 1924, 28, 387; A., ii, 395.69 J., 1924, 125, 476COLLOID CHEMISTRY. 269first author relating to the electro-kinetics of coagulation of solsby electrolytes : a reversal of the charge of the surface (colloidparticle) is possible by electrical adsorption only when the valencyof the oppositely charged ion is greater than that of the ions tothe primary adsorption of which the surface owes its charge. Whenthe oppositely charged ion is acted upon by chemical affinity of thesurface atoms, a reversal in charge is possible independent of itsvalency. The alkali-metal kations can never reverse the chargeof colloidal surfaces, as they are univalent, and their chemicalbehaviour may be summed up in their tendency to exist as ions.The alkaline-earth metal ions also are not likely to be chemicallyor primarily adsorbed.Unless the primarily adsorbed ions areunivalent, an alkaline-earth metal ion cannot reverse the chargeby electrical adsorption.Using negatively charged sols of arsenious sulphide, mercuricsulphide, sulphur, gamboge, and mastic, a large number of inorganicand some organic electrolytes were tried. I n no case was a reversalof sign obtained with the kations H, Li, Na, K, Rb, Cs, Ca, Ba,even although in some cases saturated solutions were used.K. C. Sen, P. B. Ganguly, and N. R. Dhar 70 have investigatedthe coagulation of negative and positive sols of ferric hydroxide,and of negative antimony sulphide sol by electrolytes. Quite anumber of interesting results were obtained. Thus when theconcentration of the sol is changed, the order of the coagulativepowers of different electrolytes alters.Again, in determining thecoagulative powers the effect of the opposite ion must be considered.In the case of the positively charged ferric hydroxide sol (anioniccoagulation), the Schulze-Hardy law of coagulative powers is borneout. On reversing the charge on the sol, the order of the precipitatingions is reversed.In the majority of cases, the greater the concentration of the solthe greater is the amount of electrolyte necessary for coagulation.Certain conclusions of E. F. Burton ( J . Physical Chem., 1920, 24,701 ; 1921, 25, 517) are questioned.An investigation on the coagulation of negatively charged goldsols has been made by D.C. Henry and V. A. Morris,71 who useda series of salts of the same kation (sodium), with a view to ascer-tain the relative stabilising powers of the various anions, a pointwhich has received little attention hitherto. The results indicatethe following sequence of stabilising power of various anions whenassociated with sodium ion in the coagulation of a gold sol:oxalate > HPO,” > GO,” > OH’, citrate > HCO,’ > Br’, 1’, acetate,valerate > butyrate, CNS’ > SO,’‘ > Cl‘, benzoate. The ionic series71 Trans. Paraday SOC., 1924, 20, 30.,70 J. Physical Chem., 1924, 28, 313270 ANNUAL REPORTS ON THE PROGRESS OF CHEmSTRY.deduced by various workers for a.dsorptive and coagulative processesindicate ionic adsorption to be highly specific to the adsorbent.The influence of anions on the coagulation of negatively chargedsuspensions (sols of arsenious sulphide and gold) with variousalkali metals and with acids is dealt with by J.N. Mukherjee andS. G. C h a ~ d h u r i . ~ ~ I n the case of Cl’, Br’, NO,’, and SO4”, theanions have little influence, but complex anions such as benzoate,ferricyanide, or salicylate exert a marked influence, a higher kationconcentration being necessary for coagulation.The actual coalescence of particles when a gold sol and a chromicoxide sol are mixed together has been described by R. Wintgenand H. L o ~ e n t h a l , ~ ~ who followed the coagulation process by meansof an immersion ultramicroscope. The same authors 74 haveinvestigated the mechanism of the reciprocal precipitation ofcolloids, using stannic oxide, peptised with alkali, and chromicoxide sols.Precipitation occurred only within narrow limits andwith a pronounced maximum (as shown by the absence of a ‘‘ Tyndallbeam ”). Without regard to the dilution of the sols before mixing,the maximum precipitation occurred when the proportions were ascalculated from the theory that such reciprocal precipitation is amaximum when the concentrations of the sols, expressed in gram-equivalent aggregates per litre, are the same. (“ Equivalentaggregate” = the weight of a particle divided by the number ofits charges.)When an electrolyte is added to a colloidal suspension, but inamount too small to effect coagulation, a definite degree of pro-tection is sometimes conferred on the suspension.A. Boutaricand Mlle G. Perreau 75 have worked on this matter. The rate ofcoagulation of colloidal sols to which numerous electrolytes wereadded was followed by measuring the absorption of monochromaticlight ( A . , 1921, ii, 537). When part of an electrolyte solution isadded to the sol, and after some time the remainder is added, therate of coagulation is less than if all the electrolyte were addeda t once. The greater the amount of the first addition and thelonger the interval between the additions, the more pronounced isthe retardation of coagulation. If the two additions are made withdifferent electrolytes, a protective effect is seen in some cases, butin others an acceleration occurs.Although the protective actionwas observed with mastic and gamboge suspensions, arsenioussulphide sols did not so respond.72 J., 1924, 125, 794.73 Kolloid-Z., 1924, 34, 296; A., ii, 739.74 2. physikal. Chem., 1924, 109, 391; A., ii, 535.7 5 Coma rend., 1924. 179. 46: A.. ii, 595COLLOID CHEMISTRY. 27 1K. C. Sen76 has dealt with the peptising influence of benzoic,acetic, and propionic acids on aluminium hydroxide sols. The mosteffective peptising acid is benzoic, this being the acid most readilyadsorbed. As the acid concentration is increased, the stability ofthe sol increases to a maximum. For sols of the same degree ofpurity, the greater the dilution the less the stability.J. Oliver and L. Barnard 77 have an interesting paper dealing withthe influence of electrolytes on the stability of red blood-corpusclesuspensions.Later,78 they contrasted the effect of the valency ofkations on negatively charged cells with the effect of the valencyof anions on positively charged cells.Emulsions.Comparatively few papers have appeared during 1924 markingprogress in this field.W. D. Harkins and E. B. Keith 79 give a very condensed statementof the experiments made to support the oriented wedge theoryof emulsions. Where soap is the emulsifying agent, the factordetermining the size of dispersed oil globules in water is the shapeof the soap molecule. Inversion of an oil-in-water emulsion to thewater-in-oil type caused by the addition of the salt of a bivalentmetal is due to the great increase in cross-section of the oil-likeend (compare Finkle, Draper, and Hildebrand, J .Anzer. Chem. Xoc.,1923, 45,2780). It is found that the size of the oil globules dependson the nature of the oil and on mechanical factors such as the degreeof mixing.P. A. van der Meulen and W. Rieman 80 have investigated mono-molecular films of sodium ricinoleate in emulsions, the object beingto determine the average area of interface covered by a moleculeof sodium ricinoleate in emulsions of a phenol-toluene mixture inwater. Keeping the ratio of the internal to external phase practi-cally constant (1 : 54), but varying the concentration of the soappresent in the external phase, it was found that the average areaof interface covered by a molecule of the soap is a function of thesoap concentration.Assuming that with dilute soap solutionsthe adsorbed molecule lies flat in the interface, but that in moreconcentrated solutions the C0,Na group only is in the interface(the remainder of the molecule being in the oil phase), the authorsconclude that the average area of interface per adsorbed moleculeof sodium ricinoleate varies between 22 sq. A. and 111 sq. A.The former value is the cross-section area of the carboxyl group76 J . PhysicaE Chem., 1924, 28, 1029; A., ii, 830.7 7 J. Oen. Physiol., 1924, 7, 99; A., ii, 831.7 8 LOC. cit., p. 225. 79 Science, 1924, 59, 463; A., ii, 730.J . Amer. Chem. SOC., 1924, 46, 876; A., ii, 389272 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,and the larger value is the cross-section area of a molecule ofricinoleic acid.S. S.Joshi *l finds that the surface tension of emulsions of oil inwater, no free oil or other impurities being present, is identicalwith that of the water. Similarly, the surface tension of an emulsionof oil in sodium oleate solution is identical with that of the soapsolution alone. Again, when castor or olive oil is the dispersionmedium, water being present as the emulsified globules, and soapis the emulsifying agent, the surface tension of the emulsion ispractically that of the oil. Thus the inversion point of an emulsionmay be determined by noting when a sharp change in surface tensionoccurs during the treatment of the emulsion, e.g., on addition ofelectrolytes.M.H. Fischer still emphasises the resemblance of soap solutions toemulsions such as phenol and water,82 or to a gelatin-water 83system, pointing out that on cooling there is a sudden decrease inconductivity, which in the case of emulsions marks the inversionpoint. M. E. Laing and J. W. McBain,g4 however, maintain thatsoap solutions are not emulsions and that the decrease, which theyalso observed, is due to the soap crystallising cut in the form ofcurd fibres.A detailed study of the cataphoretic mobilities of oil drops inwater and weak electrolytes has been carried out by M. Mo0ne3;,~5using " nujol," bromoform, bromonaphthalene, phenetole, and otheroils. He finds that, for emulsions of ten oils in pure water, themobility for a field of 10 volts per cm.inereases with the diameterof the oil drops for the range from (3.0005 mm. to 0.4 mm. Asthe potential gradient varies, small drops maintain a constc"ntmobility, but drops larger than 0.02 mm. in diameter show a slightincrease for fields of 10 volts Fer cm. It is suggested that theelectrical double layer around a drop is considerably distorted byan external electric field, so that equilibricm is established ratherSeveral papers which have a direct bearing on the subject ofemulsions may be mentioned under this heading.Adsorption and interfacial tension a t liquici-liquid interfacesin relation to the Gibbs adsorption equation have been investigatedby J. H. Mathews and A. J. Stamm.86 By the drop-weight method(vide Harkins et alii, J .Amer. Chem. Soc., 1916, 38, 228; 1919, 41,490), the interfacial tensions of two binary mixtures against waterslowly.81 Kolloid-Z., 1924, 34, 197, 280; A., ii, 529, 731.82 Ibid., p. 94; A., ii, 234. 83 Ibid., 1924, 35, 138; A., ii, 728.3* Ibid., 18; A., ii, 593 Physical Review, 1924, 23, 396.J . Amer. Chem. SOC., 1024, 46, 1071COLLOID CHEMISTRY. 273were determined, using dimethylaniline and heptane, and di-methylaniline and benzene. The results obtained support Lang-muir’s adsorption theory. Thus, adsorption is one molecule thickup to concentrations where a complete surface layer is formed, andthe molecular thicknesses and cross-sections agree with thosededuced by Langmuir. When a complete interfacial layer is formed,adsorption continues and the layer thickens.E. M.Johansen 87 employed the drop-weight method to determinethe interfacial tension between petroleum products and water.Rise of temperature lowers this tension, whilst organic acids andother impurities exert a marked depressing influence on it.The work of Donnan (2. physikal. Chem., 1899, 31, 42; Kolloid-Z., 1910, 4, 208) on adsorption, interfacial tension, and emulsifyingefficiency in the case of oils and the sodium salts of the saturatedfatty acids has been verified by R. Dubrisay and P. Picard.s8 Thecolloidal phenomena starting with lauric acid have been followedfor higher hornologues and found to be more pronounced as themolecular weight increases. Later work by Dubrisay s9 deals withthe capillary phenomena which are manifested a t a benzene-waterinterface in the presence of fatty acids and alkalis.From lauricto stearic acid, the surface energy increases with rise in molecularweight, but failure of the rule begins with arachidic acid.Soaps.Two prpers of great importance in this field have appezred fromthe Bristol laboratory. M. E. Laing 9O has given a detailed study ofmigration, electrophoresis, and electro-osmosis of sodium oleate inan attempt to demonstrate the fundamental similarity betweenvarious processes of electrolytic conduction. J. W. McBain 91follows this paper with one on the conception and properties of theelectrical double layer and its relation to ionic migration.From extensive experiments on the electrolytic migration of theconstituents in solutions of sodium oleate (as sol, gel, and curd)Laing concludes that electrolytic migration, cataphoresis, andelectrical endosmosis are strictly identical.A general formulais given, n, = clmlfl/u, where nl = the Hittorf migration number,c1 = number of chemical equivalents per kilo. of solvent, ml =number of chemical equivalents which carry one electric charge,f l = conductivity in reciprocal ohms of one chemical equivalent,8 7 J . Ind. Eng. Chem., 1924, 16, 132.s 8 Compt. rend., 1924, 178, 205. 89 Ibid., p. 1976.J . Physical Chem., 1924, 28, 673; compare G. W. F. Holroyd andJ. E. W. Rhodes on “ The Electrolysis of Potassium Oleate,” J., 1924, 125,438.91 J . Physical Chem., 1924, 28, 706; A . , ii, 504274 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and u = total conductivity (i.e,, the sum of the concentration ofeach conducting constituent multiplied by its mobility).Thisformula expresses the actual movement relative to the solvent of eachconstituent of any electrically conducting system (homogeneousor heterogeneous), electrolytic, colloidal, or involving double layersor diaphragms. The only distinction between colloid and crystalloidis the number of chemical equivalents which are associated withone electrical charge.It is shown that " the relative movement of soap and water isindependent of whether the soap is moving as particles of jelly oras one mass of jelly or whether the water is forced through the soapjelly, and the same value is obtained when the jelly is completelytransformed into a fluid ordinary sol.. . . Whereas in dilutesolution the migration of sodium oleate is that of an electrolyte,in the more concentrated solutions rather more sodium is movedtowards the anode than towards the cathode. In a curd stillmore movement towards the anode is observed which may in somecases exceed five equivalents of oleate per one faraday of current.''Laing finds the conducting constituents to be Na' ion, a smallamount of simple oleate ion, a highly-conducting micelle, andthe slightly-charged, undissociated soap, this moving one-thirdtimes as fast as the ionic micelle and independently. Soap ishydrated in solution, there being ten moles of water for sodiumoleate, thirteen for potassium oleate, and not exceeding seventeenfor potassium laurate, reckoned in each case per equivalent oftotal soap.Full experimental details and the measurements madeare recorded.McBain, after discussing the Helmholtz double-layer as conceivedby such investigators as Helmholtz, Lamb, Perrin, Freundlich, andothers, points out that " the fundamental assumption in all theseprevious calculations has been that the charges, or rather the mobileions, form an effectively complete sheath, shutting off the bodyof the liquid in the tube from the annular space of the doublelayer. If this be so, the bulk of the liquid must move along withthe mobile ions and in a migration experiment the mobile ionswould not appear to have moved perceptibly relative to the solvent."The work of Miss Laing shows this does not represent the facts insols, gels, and curds of soap.McBain puts forward a conception ofthe double layer with sparsely distributed mobile ions, whichapparently ha<rmonises the existing data, including Miss Laing'sdata and those for absolute electrode potentials. It is suggestedthat only a very few of the ions in a double layer are mobile, theremainder being sessile and immovable.A joint communication by Laing and McBain 92 deals with jellies92 Kolloid-Z., 1924, 35, 19; A., ii, 693COLLOID CHEMISTRY. 275as contrasted with gels and curds, A ‘jelly’ is a completelytransparent elastic mass, ‘ gels ’ being flocculent and gelatinousprecipitates. Jellies may be obtained without marked interferencewith the equilibria in the solution; gels cannot.Soap solutionsor jellies are not emulsoids.The structure of soaps has been investigated by R. Zsigmondy 93 andby E. K r a t ~ . ~ ~ The former, on the basis of the vapour pressure-concentration diagram, believes the water in soap is enclosed in capil-laries formed by the framework of fine, needle-like crystals of thesoap, ultramicroscopic in two dimensions. Kratz finds that soapsolutions contain crystal leaflets, needles, and threads in variousaggregations and combinations.A systematic investigation of the surface tensions of solutionsof the sodium salts of fourteen saturated fatty acids (between C,and C2& has been made by L. La~caray.9~ The capillary activityof the soap increases as the molecular weight increases, reaching amaximum a t C14 (sodium myristate), then decreases, being verysmall for C,, (sodium cerotate).The surface tension-conccntrationcurve for the soaps, sodium hexoate to laurate, shows an inflectionpoint a t the concentration where sudden clearing occurs. Thisinflection point is connected with the electrolytic dissociation,hydrolysis, and colloidal structure of the soap solutions.The electrical conductivity of soaps in the fused state and inethyl, propyl, butyl, and amyl alcohols has been studied by S. S.Bhatnagar and M. P r a ~ a d . ~ ~ The conductivity in the fused soapsis electrolytic, rise in temperature increasing the degree of dis-sociation. The conductivity in amyl alcohol was too low to bemeasured, but with the other alcohols the higher the alcohol the lowerthe conductivity, this agreeing with the Nernst-Thomson rule(2.physikal. Chew., 1894, 13, 531). The equivalent conductivityof soap solutions in alcohols increases with dilution. Alcoholicsoap solutions do not obey the Ostwald dilution law.Eflect of Hydrogen-ion Concentration.That colloidal systems generally have properties intimatelyconnected with the hydrogen-ion concentration of the medium isbecoming more and more recognised. Numerous papers haveappeared recently supporting this statement. The more importantwill be briefly mentioned.P. Rona and F. Lipmann 97 have observed the effect of alterationsS3 2. phy.9ihl. Chem., 1924, 108, 303; A., ii, 391.91 2. deut. Oel-Fett-Ind., 1924, 44, 25, 37, 49, 62.9 5 Kolloid-Z., 1924, 34, 73; A., ii, 236.96 Ibid., p.193; A., ii, 525. 9 7 Biochem. Z., 1924, 147, 163; A., ii, 596276 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in hydrogen-ion concentration on the precipitation of positiveand negative ferric hydroxide sols. As the pR value increases,the positively charged sol becomes more sensitive to the coagulatingaction of anions. The anionic series (unaffected by the p , value)is (Br, NO,, Cl) < CNS < F < SO, < citrate.F. Demuth 98 finds an optimum pH value (about 4.5) for the rapidprecipitation of the casein of human milk, in the presence of suitablebuffer mixtures.The important tests based on the interaction between spinalfluid and colloidal benzoin or colloidal gold solutions depend on thep , value.L. W. ShafTer 99 reports that the factors affecting the zoneof precipitation are the alldinity of the spinal fluid, its dilution,and the pH of the reagent colloid.The influence of hydrogen-ion concentration on the growth ofcertain bacterial plant parasites and saprophytes has been studiedby E. M. Berridge,l whilst H. Leffmann2 has given a summary ofthe work done on the relation of hydrogen-ion concentration toanimal and plant growth, body fluids, etc.Several papers deal with pE values in relation to tanning. Whenbenzoquinone combines with hide substance to form leather, therate of tanning is a function of the pH value of the solution, themaximum being a t pH 8-10.3 Similarly, when defatted hide powderis tanned by means of gallotannic acid, the minimum rate of tanningis in the region of the isoelectric point of collagen ( p , = 5).4 Dataare given to show that tannin fixation a t and upon the acid sideof the isoelectric point of collagen is of lower degree of tenacitythan that on the alkaline side.5 has shown that, inalkaline solution, hair is more readily hydrolysed than skin, thereverse being true in acid solution.The effect of hydrogen-ion concentration has been investigatedin connexion with clays, adsorption of dyes, colloid propertiesof soils,g and the use of gelatin in the electrolysis of inorganic saltsolutions.l*H. B.Merrill98 Biochem. Z., 1924, 150, 144; A., i, 1134.J . Lab. Clin. Med., 1924, 9, 757.1 Ann. Appl.Biol., 1924, 11, 73.2 J . Franklin Inst., 1924, 197, 741.3 A. W. Thomas and M. W. Kelly, J . Ind. Eng. Chem., 1924, 16, 925.4 Idem, ibid., p . 800. Ibid., p . 1144.7 R. Bradfield, J. Physical Chem., 1924, 28, 170; A , , ii, 237.8 R. E. Marker and N. E. Gordon, J . Ind. Eng. Chem., 1924, 16, 1186.10 P. K. Frohlich, Tram. Amer. Electrochem. SOC., 1924, 46, 153; A.,LOC. cit., p. 31.R. Bradfield, Soil Science, 1924, 17, 411.ii, 728COLLOID CHEMISTRY. 277Proteins.D. M. Greenberg and C. L. A. Schmidt l1 have published threepapers : Studies on the formation and ionisation of the compoundsof casein with alkali. (i) The transport numbers of alkali caseinatesolutions ; (ii) the conductivities of alkali caseinate solutions ; (iii)the electrochemical behaviour of racemic casein.The deposition of casein on a platinum anode occurring whendirect current passes through solutions of alkali caseinates wasstudied quantitatively, and showed that the deposition obeys Fara-day's law; also the amount of casein deposited is inversely pro-portional (within the limits studied) to the amount of alkali combinedwith the protein.The bases used were cmium, potassium, sodium,and rubidium hydroxides. The mobility of casein ion calculatedfrom the transference numbers a t 30" varied somewhat with thenature of the kation, but was surprisingly high, from 43.0 to 46.5mhos. The authors discuss the high value of this mobility inrelation to McBain's theory of colloidal electrolytes (J. W. McBainand C. S.Salmon, J . Amer. Chem. SOC., 1920,43,426). The temper-ature gradient of the casein-ion mobility was determined as 3 mhosper degree centigrade (as against 1.05 mhos for Na', 1-32 mhos forK', and 1.44 mhos for Cs'). Just its McBain found a high con-ductivity temperature coefficient in soap solutions, which he explainsby assuming a dehydration of the complex soap micelle, so probablydoes dehydration occur in protein solutions, the viscosity thendecreasing as the temperature rises.Greenberg and Schmidt sum up by stating that they believe caseinions and inorganic liations are present in the solutions and act asthe carriers of the electric current.The physical chemistry of casein has been investigated in consider-able detail by E. J. Cohn, R.E. L. Berggren, and J. L. Hendry,12in a study of the amino-acid composition of casein and its capacityto combine with base. The coagulation of casein from calciumcaseinate solutions by means of hydrochloric acid and its relationto hydrogen-ion concentration have been dealt with by F.Loebenstein. l3The iso-electric point of pure hide gelatin has been found to be a t p , 5.5,that of bone gelatin being less than pH 5-0.1* D. J. Hitchcock l5finds that gelatin a t 40" retains its isoelectric point a t about pE 4.7.This is deduced from his measurements of the osmotic pressure 2ndSeveral papers relating to gelatin are of importance.l1 J . Gen. Physiol., 1924, 7, 287, 303, 317.l1 0. Gerngross, J. Arner. Leath. Chem. ASSOC., 1924, 19, 258.l5 J .Gen. Phyeiol., 1924, 6, 456; A., ii, 460.l2 Ibid., p. 45. '3 K ~ l l ~ i d - Z . , 1924, 34, 227278 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.viscosity of 1 % gelatin solutions (at 40") containing varying amountsof hydrochloric acid or sodium hydroxide,The equivalent weight of gelatin is given as 1180 by W. R. Atkinand G. W. Douglas,lG from pa values resulting when standard hydro-chloric acid or sodium hydroxide was added to 1% solutions ofiaoelectric gelatin. The titration curve apparently consists of fourportions, p , 1.7-4.7, pE 4.7-7.7, px 7-7-12.6. The significance ofthese definite p , regions is dealt with.The value of the molecular or equivalent aggregate weight ofgelatin as found by R. Wintgen and H. Lowenthal l 7 is about 30,000.The method employed depends on the reciprocal precipitation ofgelatin and chromic oxide hydrosols.The dissolution of gelatin on standing in contact with water ordilute acids or alkalis a t the ordinary temperature has been studiedby F.Fairbrother,l* who suggests that the framework of a gelatingel consists of isoelectric gelatin and gelatin kations.F. E. Brown l9 has criticised the work of Svedberg and Stein ( A . ,i, 104) on density and hydration in gelatin sols. He disput,es theconclusion that density changes are due to the formation of a shellof highly compressed water around the gelatin particle. Svedberg 20accepted Brown's criticism and agreed the measurements made wereinsufficient on which to base conclusions regarding the hydrationof gelatin.Further experiments have now been made on theswelling and dissolution of gelatin in water and under the influenceof acids and alkalis, neutral salts and non-electrolytes.W. G. France and W. H. Moran2l have studied the influence ofgelatin on the transference numbers of hydrochloric acid. Theyconsidered that their results support the view that gelatin reactswith acids to form an adsorption complex or additive chemicalcompound which dissociates. G . Scatchard 22 criticises this workand shows that the theoretical and the experimental treatment ofthe problem are much more complicated than France and Moranbelieve. He finds no evidence in their paper to support the viewoutlined, whereas other workers (Loeb and Hitchcock) haveexperimental support of it.Determinations of the surface tension of gelatin solutions havebeen carried out in relation to concentration, p,, and temperat~re.2~A transition point was evidenced a t 38".As the gelatin concentrationI6 J . SOC. Leather Trades Chem., 1924, 8, 359; A., ii, 592.l7 Rolloid-Z., 1924, 34, 289; A., ii, 739.l8 Biochem. J., 1924, 18, 647; A., ii, 592.*O Ibid., p. 2673. Ibid., p. 19.23 C. E. Davis, H. 31. Salisbury, and &I. T. Harvey, J . Ind. Eng. Chem.,J , Amer. Chem. Xoc., 1924, 46, 1207; A., ii, 660.22 Ib,id., p. 2353.1924, 16, 161 ; A., ii, 235COLLOID CHEMISTRY. 279is increased, surface tension diminishes. With the more con-centrated gelatin solutions, rise in temperature raises surface tension,reaching a maximum; the surface tension now decreases as thetemperature approaches the transition point.Above this temper-ature, the surface tension remains nearly constant. With increasingpH values, gelatin solutions of all concentrations point to a maximumsurface tension at the neutral point.H. P. Higley and J. H. Mathews 24 have investigated, by a spectro-photometric method, the relationship between the wave-length ofmaximum absorption in the ultra-violet and the p , values of 1%gelatin solutions. The results are given in the form of curves inwhich p , values are abscisw and the ordinates are wave-lengths fordefinite fractions of light absorbed, the fraction being 0-75, 0.6,0.4, and 0 (transparent). There is a sharp shift of the absorptionband toward the ultra-violet as the pE values of 4.69 and 7.65 areapproached.The f i s t value is about the accepted isoelectric pointfor gelatin, whilst p , 7-65 is close to the value given by Wilson andKern for the minimum swelling of gelatin. Two points of maximaare shown a t about pH 3.7 and pE 6.6, which values agree with thosefound by Loeb and G. Wilson and Kern respectively.An important paper by N. D. Scott and The Svedberg 25 concernsthe measurement of the mobility of egg-albumin a t different acidities.The cataphoretic position of the protein layer was determined byphotographing the fluorescence when illuminated by ultra-violetlight. The authors believe their measurements to be “ practicallythe first direct quantitative measurements of the mobility of anatural protein.” Buffer mixtures of sodium acetate with acetic acidand of disodium hydrogen phosphate with citric acid were used overa range of pE from 7 down to about 3 and 2.5, respectively.Mobilityis most intimately related to p,, and the maximum mobility observedwas toward the cathode, 21-79 x cm. per second a t a p, of2.93.Membrane Equilibria.An interesting essay on ‘‘ The Theory of Membrane Equilibria ”has been published by F. G. Donnan,26 who surveys the work ofhis collaborators and also the views of Loeb and Proctor and Wilson.Donnan emphasises that the theory of membrane equilibria dependssimply on the assumption of the existence of equilibrium, and theexistence of certain constraints restricting the diffusion of one ormore electrically charged or ionised constituents.The simplemathematics of the Donnan equilibrium are given for various24 J . Amer. Chem. SOC., 1924, 46, 852; A., ii, 460.25 Ibid., p. 2700. 26 Chernhl Revieu~8, 1924, 1, 7280 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.possible cases. Fair agreem’ent between theory and experiment hasrecently been found in the study of the equilibrium between sodiumcaseinate and potassium caseinate across a membrane of parch-ment paper; also in the case of sodium caseinate and sodiumchloride.J. Loeb 27 has investigated the influence of electrolytes on mem-brane potentials and cataphoretic potentials. The active ion inthe depressing action of electrolytes on membrane potentials as wellas on cataphoretic potentials has the opposite sign of charge tothat of the colloidal particle.Only the valency, not the chemicalnature, of the active ion determines this depressing effect, as nowproved with suspensions of collodion, mastic, Acheson’s graphite,and denatured egg-albumin. The influence of dilute acids on thecataphoretic P. D. of gelatin-coated collodion particles depends onlyon the pH value and the valency rule. Observation of the depressingeffects of salts with univalent and bivalent kations on the cat-aphoretic P.D. of collodion led Loeb to conclude with Wilson (“ TheChemistry of Leather Manufacture,” New York, 1923, p. 128) thatthe cataphoretic P.D. between particles and an aqueous solution(no chemical changes taking place) is due to a Donnan equilibriumbetween the film which adheres to and moves with the particles incataphoresis and the oppositely charged film of the double layer,The film moving with the particle has (in, for example, gold particlesin sodium chloride solution) an excess of kations, whilst the otherfilm of the double layer has a corresponding excess of anions.An inquiry into the molecular nature of the ultimate particlesin protein solutions has been made by J.Loeb and M. Kunitz,2susing a viscosimetric method, on the view that the viscosity of suchsuspensions as casein in hydrochloric or orthophosphoric acid isdue to the aggregation of protein particles, which swell in accordancewith the Donnan equilibrium, The experimental results obtainedwere used to ascertain whether the ultimate units of genuine pro-tein in SoZutions are aggregates large enough to give rise to a Donnanequilibrium, or whether they consist of particles below this limit,and in what ratio the two kinds of units occur in the solution.Thuswhen 1 g. of isoelectric casein is dissolved in hydrochloric acid,the final solution being at pH = 2.45, more than 0.5 g. of caseinexists in the form of particles too small to give rise t o the Donnanequilibrium, but the rest are still capable of swelling in acid.&I. Kunitz 29 has made a detailed study on the influence of salts onthose physicochemical properties of sodium gelatinate which areregulated by the Donnan equilibrium, vix., osmotic pressure, mem-2 7 J . Gen. PhysioZ., 1924, 6, 307; A., ii, 310.28 Ibid., p.479; A., ii, 4GO. 29 Ibid., p. 547; A., ii, 4G1COLLOID CHEMISTRY. 281brane potential, and swelling. The results obeyed the same valencyrules as in the case of the influence of salts on gelatin chloride (Zuc.cit., 1922-23, 5, 665, 693). The rules state that, when a salt isadded to an ionised protein without causing a change in pH of theprotein, the general effect is a depression of the mentioned properties.The degree of depression depends, not only on the concentration ofthe salt, but also on the electrical properties of the ions of the salt.Of the two or more oppositely charged ions of which a salt consists,only the valency of those ions which carry charges of opposite signto those carried by the protein ions affects the degree of dispersion,which increases with the valency of the ions.Donnan's theory is supported by experiments on the ion activityratios for the inside and outside of gelatin particles.E.M.P.measurements were made by J. H. Northrop and M. Kunit~.~OThe ratios of the total concentrations of calcium, magnesium,potassium, and zinc do not agree with the calculated ratios, probablybecause of the formation of complex ions with the protein. Sinceprotein combines less readily with chlorine than with zinc, theaddition of zinc chloride to isoelectric protein should give rise toan unequal distribution. That this is the case was shown by anincrease in swelling, osmotic pressure, and viscosity.The relation between membrane equilibria and the electric chargeof red blood-cells has been investigated by C.B. C ~ u l t e r , ~ ~ whofinds that the Donnan equilibrium determines the distribution ofhydrogen- and chlorine-ions between the cell and the surroundingfluid. The distribution of the HPO," ion, however, appears to bemainly influenced by the relative impermeability of the cell membraneto this anion.C. D. Murray 32 has described a system consisting of two aqueoussolutions containing equal concentrations of lactic acid, but differentconcentrations of sodium lactate, separated by a layer of amylalcohol. The amyl alcohol acts as a semipermeable membraneand is relatively impermeable to sodium ions, which here play ther6Ze of the protein ions often used in similar studies with collodionmembranes. As the concentration of sodium lactate increased,electrical properties were exhibited ranging from those characteristicof a simple Donnan equilibrium to those characteristic of simplediffusion.Murray emphasises the fact that the Donnan P.D. canbe treated as a special case of a diffusion potential.Confirmation of Donnan's theory of membrane equilibrium hasbeen obtained by N. Bjer~wm,~~ working with an exceedingly stablesol of chromium hydroxide. This was contained in a collodion30 J . Gen. Physiol., 1924, 7, 25; A., ii, 831. 31 I&!., p. 1 ; A., ii, 835.32 Ibid., 1924, 6, 759; A., ii, 744. 8a 2. physikal. Chem., 1924, 110, 656282 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.membrane, bathed by solutions of various electrolytes, and measure-ments were made of osmotic pressure, membrane P.D., and p , value.For colloidal ions with constant electric charge, Bjerrum deduces therelation that the osmotic pressure due to the colloidal particlesthemselves is independent' of the concentration of electrolytes andproportional to the chromium concentration. On the other hand,the osmotic pressure resulting from the Donnan membrane equili-brium varies inversely as the concentration of electrolytes anddirectly as the square of the chromium concentration.E. B. R. Prideaux and W. E. Crooks 34 have published the resultsof an investigation on the diffusion potentials and ionic mobilitiesof benzoates and salicylates, and their modification by a membraneof parchment paper. This paper is interesting, since a true semi-permeable membrane is not used, so that both ions can pass, althoughthe slower ion is proportionately more impeded.Periodic Precipitation and the Liesegang Phenomenon.A number of authors propose new theories of the Liesegangphenomenon.R. Fricke 35 concludes that the ordinary diffusionequations, suitably modified to allow for the removal of solute byprecipitation, combined with the assumption of a metastable limit,adequately explain the occurrence of rhythmic precipitation, andeven details of the conditions in which they are formed. Exper-imental results with a number of reactions are given. K. C . Senand N. R. Dhar 36 dispute the conclusion drawn by A. M. Williamsand M. R. Mackenzie 37 that silver chromate diffuses as a crystalloid,and assume the formation of a silver chromate sol by peptisationand the periodic coagulation of this sol.J. Traube and K. Takehara 38give a rough sketch of yet another explanation, which is based onexperiments by the latter 39 on precipitation in gelatin sols. Thevariations in the colour and dispersity of the precipitate, caused byvarying concentrations of the reaction components, are supposedto occur also in the gel, when the same concentrations are established ;no experimental evidence of the correctness of this assumption is,however, given.C. A. Schleussner 40 investigates the distance between the silverchromate rings of the original Liesegang experiment and confirmsthe result that they increase in geometrical progression.This lawapplies also to the " intermediate '' rings separated by microscopicintervals. H. Handovsky and E. du Bois-Reymond 41 obtain34 Trans. Farachy SOC., 1924, 20, 37.35 2. pkysikal. Chern., 1924, 107, 41.36 Kolloid-Z., 1924, 34, 270.38 Kolloid-Z., 1924, 35, 245.37 J., 1920, 117, 844.3g Ibid., p. 233.41 Ibid., 33, 347. Ibid., p. 338COLLOID CHEMISTRY. 283rings by allowing alkaloid solutions to diffuse into gelatin containingiodine in potassium iodide. S. S. Bhatnagar and K. K. Mathur 42draw a parallel between Liesegang rings and the concentric ringsof vesicles in Herpes tonsurans, with the suggestion that the latterare caused by acid produced by the micro-organism. M. WatanabeY43in a study of diffusion problems in reference to ore deposits, givesparticulars of numerous periodic precipitations, chiefly of hydroxidesand sulphides.Various authors describe stratifications obtained in the absenceof gels. J.Brodersen 44 produces them by allowing sodium chloridesolution to diffuse into silver nitrate solution contained in the capillaryspace between two cover-glasses. The number of strata increaseswith decreasing depth of the space. P. D. Zacharias45 describesa periodic deposit formed on the wall of a bottle containing a naturalmineral water and consisting largely of clay, with organic matterand very little sulphur. A. Janek46 places a crystal of silvernitrate, covered with it drop of water, on dichromate-gelatin : thedrop is gradually covered with a banded membrane of silver chromate,which grows from the periphery towards the centre.Gels.A.Szegvari 47 describes a sol of cellulose nitrate in amyl acetate-light petroleum, which gelat& reversibly on heating. The viscosityof the sol and its tendency to gelate do not run parallel. R. ReigerY4*in a long mathematical paper on the kinetics of gelation, discussesthe change in optical rotation with time. Above a certain temper-ature, rotation is independent of time; a t lower temperatures, itincreases with time, and this change is held to prove molecularrearrangement. Careful examination of the time-rotation curvesshows that the change proceeds by steps, each of which is of thesimplest type, wix., monomolecular. The differential equations forthe assumed series of steps are developed and integrated. Graphsfor the change in rotation a t 25” during 120 minutes show two breaks.The other methods of studying gelation, vix., time-viscosity andtimeelasticity curves, are then discussed, and both, when ca,refullyplotted, show the discontinuities required by the theory. Sh.Dokan deals with the effects of electrolytes on the swelling of agar 49and of (‘ konyaku,” 50 the starch of ( ( a tuber resembling the potato ’’gelatinised by alkali and sold, as a common article of food, in sheets42 Kolloid-Z., 1924, 34, 104.43 Sci. Rep. T6hoku Imp. Univ., Ser. 3, Vol. 2, Nos. 1 and 2.45 Ibid., 34, 38.4 8 Koll. Chern. Beihefte, 1924, 19, 381.4s Kolloid-Z., 1924, 34, 155.44 Kolbid-Z., 1924, 35, 21.48 Ibid., 33, 86.47 Ibid., 34, 34.so Ibid., 35, 11284 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.resembling gelatin. The swelling of agar is depressed by all salts.The pH of the solution is of very little influence up to about 5.0.With low concentrations of salts, the effect is due entirely to thekation, and the depression of swelling increases with increasingvalency . Hydrogen ion is anomalous and depresses swelling evenmore than aluminium ion. With concentrations higher thanOnOlN, the specific effects of the ions appear, and the anions groupthemselves in the order of the normal Hofmeister series. Theeffects on konyaku differ considerably from those on agar. Chloridesin concentration below 0.1N have no effect ; in higher concentrations,the kations on the whole follow the ordinary lyotropic order.Hydrogen ion does not occupy an exceptional position.No well-defined equilibrium is attained in swelling, as peptisation occurspari passu. Peptisation takes place in 24 hours with concentrationsof the order 1.ON; the stronger the swelling, the more marked ispeptisation. The viscosity of the sols is unaffected by electrolyteconcentrations below 0.1N ; in higher concentrations, the sur-prising result appears that the more a given ion promotes swellingthe more it depresses the viscosity. Hydroxyl ion occupies anexceptional position and reduces viscosity already in low con-centrations.G. Wendelmuth 5l studies the gelation of fruit juices and of sols ofpure pectin prepared from the endocarp of oranges and lemons.Thetheoretical conclusions drawn are : the tendency to gelate is reducedby purification and by ageing; the viscosity of the dilute boiledmixtures of fruit juice and sugar is parallel with the strength of thefinished jelly ; the effects of sugar content, pectin concentration andp, can be estimated quantitatively ; gelation is not simply a functionof temperature or electrolyte concentration, as jellies equal to thoseobtained by boiling can be prepared by stirring fruit juice with sugarin the cold. Theeffect of calcium chloride on acid-sugar-pectin gels has beeninvestigated by E. G. Halliday and G. B. Bailey.52 The percentageof pectin, acid, and sugar used for a standard jelly were each inturn lowered to a point where an acceptable jelly failed to form in agiven time.To these non-jelling mixtures, calcium chloride wasadded and in every case gelation took place. Additions above0.5-1.0% were without further effect, but promoted syneresis.S. E. Sheppard and S. S. Sweet 53 examine the connexion betweenthe empirical jelly strength figures obtained with various testersand the elast'ic constants of gelatin gels. The apparent jelly strengthis a function of the size of the test piece; elongation tests show5 1 Koll. Chent. Beihefte, 1924, 19, 115.52 J . Ind. Eng. Chem., 1924, 16, 595.The sugar acts chiefly as a dehydrating agent.63 Ibid., p. 503COLLOID CHEMISTRY. 285apparently high elasticity for shorter test pieces. Poisson’s ratiois found to be 112, i.e., the gel volume remains unaltered by deform-ation, which is in agreement with the results of previous observers.R.Schwarz and Fr. Stowener 54 investigate the ageing of silicic acidgels by studying the solubility in ammonia and the conductivity ofthe resulting solutions. They conclude that ageing is due todehydration of primary particles originally associated with muchwater.Adsorption.A large number of papers have been published during 1924 on thesubject of adsorption. The great activity in this field is due notonly to the wealth of theoretical problems available, but also to theincreasing technical applications of the data secured.The theory of adsorption has been dealt with by several workers.B. Iliin 55 considers the electrical nature of adsorption forces anddeduces a relation between the adsorption capacity and the dielectricconstant of the adsorbed gel.W. Taras~off,~~ working on similarlines, shows that the heat of adsorption should be proportional to( E - 1 ) / ~ , where E is the dielectric constant of the adsorbed gas.The adsorption of gases by solids has been examined by J. Frenkel 57from a kinetic point of view. The theory of ionic adsorption hasbeen studied by A. Gyernantyss his equations being developedthermodynamically and involving the electrokinetic potential 5,as distinct from the thermodynamic potential, E. F. E. Bartelland E. Miller 59 extend Langmuir and Harkins’s theory of adsorptionand orientation a t interfaces to their work on charcoal as adsorbentin water and solutions. The origin of the electrical double layeris discussed as a case of orientation of adsorbed ions.A series of papers on adsorption has been published by P.N.Pavlov.60 His third paper, on the surface tension of liquid mixturesand adsorption, is a mathematical one, and deals incidentally withthe limitations of the Gibbs equation, which should not be applied toadsorption from solutions. All the papers are theoretical and partlymathematical, and experimental data are given in support of theequations deduced.Adsorption a t a liquid-gas interface has been studied by T,Iredale,61 using mercury drops for the adsorption of gas or vapour.54 Koll. Chem. Beihefte, 1924, 19, 171.5 5 Phil. fMag., 1924, [vi], 48, 193; A., ii, 663.5 6 Physikal.Z., 1924, 25, 369; A., ii, 733.6 7 2. Physik, 1924, 26, 117.68 Z. physikal. Chem., 1924, 108, 387; A., ii, 391.59 J . Physical Chem., 1924, 28, 992; A., ii, 734.6o Kolloid-Z., 1924, 35, 3, 87, 89, 156, 159, 221, 375; A., ii, 732-733.61 Phil. Mag., 1924, [vi], 48, 177; A., ii, 663286 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Adsorption lowered the surface tension of the mercury and diminishedthe size of the drops. At saturation pressure there is a sudden fallin the surface tension and a liquid film forms on the drop. A.Frumkin 62 investigated the adsorption of inorganic electrolytes fromsolution a t the air-liquid boundary by an electrometric method andobtained results agreeing with the usual surface tension measure-ments.Thus salts which exerted the greatest charge a t the liquidsurface increased the surface tension of the water the least. Adetailed study of foams has been made by 0. B a r t ~ c h , ~ ~ whilstE. K. Rideal and C. G. L. Wolf 64 have investigated the well-knownchemical destruction of rennin solutions on agitation. Agitationcauses frothing and an increase in the air-liquid interface. Achemical reaction takes place at this interface between capillaryactive rennin and a capillary active substance present in ordinaryrennin solutions.Adsorption a t a solid-gas interface has been studied by severalworkers, mainly using charcoal :-(a) R. Lorenz and E. Wiedebrauck 65-Adsorption of oxygen,nitrogen, hydrogen, and carbon dioxide from known mixtures.Increase in the rate of flow of the gas was found to increase the timerequired to attain equilibrium.( b ) G. Sameshima and K.Hayashi66-Adsorption of air bydifferent varieties of charcoal, a t temperatures from - 185' to theordinary temperature. Coconut charcoal has the greatest adsorptivecapacity by volume, but is not much different from other charcoalson a weight basis.( c ) 0. Ruff and E. Hohlfeld 67-The effect of temperature and thenature and rate of passage of activating gases on charcoal activity.(d) A. S. Coolidge 68-Adsorption a t 0" to 300" and 0.0002 mm. to1000 mm. for benzene, carbon disulphide, carbon tetrachloride,chloroform, water, etc. He concludes that the adsorbed substanceexists as a liquid, even below the freezing point of the pure liquid.( e ) E. A. Blench and W. E. Garner 69-Determination of the heatof adsorption of oxygen by charcoal. They found that " the heatof adsorption of oxygen by charcoal for the first small quantities ofoxygen adsorbed ranges from 60 to 220 cal./mol. of oxygen adsorbedas the temperature of adsorption rises from 18" to 450", and falls offrapidly as the surface becomes saturated."62 2. physikal. Chem., 1924, 109, 34; A., ii, 462.63 Koll. Chem. Beihefte, 1924, 20, 1.g4 Proc. Roy. SOC., 1924, [ A ] , 106, 97.6 5 2. anorg. Chena., 1924, 135, 42.G G Sci. Rep. Tbhoku Imp. Univ., 1924, 12, 289.6 7 Kolloid-Z., 1924, 34, 136.GB J., 1924, 125, 1288.6 8 J . Amer. Chem. SOC., 1924, 46, 696COLLOID CHEMISTRY. 287E. C. Williams 70 has an important paper dealing with silica gelas an industrial adsorbent, whilst D. H. Bangham and F. P. Burt 71have investigated the rates of adsorption and desorption of gasesby a glass surface. The sorption values all greatly exceeded thevalues anticipated by adsorption to unimolecular films. R. Lorenzand E. Wiedebrauck 72 describe a dynamic method for determininggas adsorption.The heats of adsorption of gases on metallic catalysts have beenmeasured by R. A. Beebe and H. S. Taylor.73 The values dependon the previous history of the catalyst. For nickel adsorbinghydrogen, the heats of adsorption ranged from 13,500 to 20,500cals. per g.-mole of hydrogen, whilst the value 9600 was found for aparticularly active copper catalyst.Considerable activity has marked the study of adsorption at asolid-liquid boundary. The properties of active charcoal arediscussed by H. H. Lovv~y,~* and its preparation by Philip.75 Theadsorption of binary mixtures (pair of electrolytes) by animal char-coal and the adsorptive power of different varieties of charcoalhave been investigated by N. A. Yajnik and T. C. Rana.76 E. J.Miller 77 finds evidence that hydrolytic or decomposition adsorp-tion occurs when electrolytes are adsorbed from solution by charcoal.The adsorption of dyes on diamond, charcoal, and artificial silkhas been studied by F. Paneth and A. Radu,7* who give evidencefor the adsorption of monomolecular layers. Dyes are alsoadsorbed on crystals in monomolecular layers. 79 The questionwhether adsorption occurs as a single layer or a series of superposedlayers is discussed by G . C. Schmidt and P. Duran.80 Glass plateand powder adsorbed aniline dyes. From the data obtained, theadsorbed layer may be one or two moles deep, depending on theassumptions made as to the shape and orientation of the dyemolecules.WILLIAM CLAYTON.70 J. SOC. Chem. Ind., 1924, 43, 9 7 ~ .71 PTOC. Roy. Soc., 1924, [ A ] , 105, 481; A,, ii, 392.72 2. anorg. Chem., 1924, 134, 251,75 J . Amer. Chem. Soc., 1924, 46, 43.74 Ibid., p. 824; A., ii, 393.7 5 J. C. Philip and J. Jarman, J. Physical Chem., 1924, 28, 346; A,,76 Ibid., p . 267; A., ii, 308.7 7 J . Amer. Chern. SOC., 1924, 46, 1150; A78 Ber., 1924, 57, [B], 1221.7 9 F. Paneth and W. Thimann, ibid., p. 1216.*O 2. physikal. Chem., 1924, 108, 128; A., ii, 238.ii, 393.ii, 664

ISSN:0365-6217    

DOI:10.1039/AR9242100259

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

INDEX OF AUTHORS’ NAMESAbbott, W. E., 170.Abderhalden, 210, 215, 216.Ackermann, D., 128.Ackroyd, 2 16.Adams, R., 77, 138.Adler, L., 21.Adolf, M., 264.Ahmad, N., 2, 254.Aiazzi-Muncini, M., 113.Aihara, K., 246.Alessandri, L., 1 13.Allardt, 150.Allison, S. K., 35, 248.Allma.nd, A. J., 20, 52.Allpress, C. F., 65, 68, 71.Amadori, M., 60.Anderson, A. K., 157.Anderson, L., 267, 268.Anderson, V. L., 191.Andre, G., 155.Andrews, 172.Andrews, T. M., 85.Andrianoff, N., 78.Angelescu, B. N., 165.Angeli, A., 113, 124.Anson, 213.Antonov, G. N., 7.Aoyama, S., 54.Apolant, L., 50.Ardagh, E. G., 166.Arkel, A. E. van, 223, 224, 225.Armstrong, E. F., 13, 15.Arndt, F., 157.Arnold, C. W. B., 173.Arrhenius, S., 177.Asahara, G., 40.Asahina, Y., 142.Astbury, W.T., 4, 60, 220.Aston, F. W., 238, 239, 241, 242.Atack, F. W., 111.Atkin, W. R., 278.Atkinson, E., 156.Audova, 203.Austin, P. C., 59, 60.Auwers, K. von, 111, 113, 149, 150.Azinieres, L., 51.Bacharach, A. L., 160.Bach, A,, 67.Bacher, F., 95.REPe-VOLe XXI. 289Badische Anilin- & Soda-Fabrik, 63.Bailey, G. B., 284.Bairn, A. M., 112.Baker, J. W., 13, 57.Balaban, I. E., 147.Baly, E. C. C., 66, 69, 184, 191.Bamberger, M., 153.Bancroft, W. D., 263.Bangham, I). H., 287.Barcroft, 212, 213.Barger, G., 124, 143.Barker, 184.Barnard, L., 271.Barnes, T. W., 3, 61.Barnett, E. de B., 108.Barnette, R. M., 155.Barr, 208.Bartell, F. E., 285.Bartsch, O., 286.Bary, P., 259.Bassett, H., 34, 199.Bates, L.F., 249, 252.Batschinski, A., 7.Baudisch, O., 191.Bauer, E., 48.Bauer, K. H., 139.Baumgarten, P., 125.Baxter, G. P., 28, 239, 243.Bayle, E., 152.Bayliss, 211.Beato, J., 49.Bechhold, H., 151, 261.Becker, H. S., 170.Becker, J. A., 2.3eckmann, E., 111.3ede1, C., 154.3eebe, R. A., 287.3eegle, F. M., 14.3ehr, M., 165.3eiser, A., 80.3eja, M., 48.3el1, J. M., 43.3ellucci, I., 162.3elva1, H., 186.3enary, E., 117.senda, O., 168.lenedict, S. R., 202, 219.lennett, G. M., 9.lennett, H. B., 158.lerg, W. van der, 250.lergel, 216.290 INDEX OFBerggren, R. E. L., 277.Bergheher, E., 28.Berglund, V., 43, 218.Bergman, S. W., 70.Bergmann, M., 74, 78.Bergstrom, F. W., 45.Berl, E., 154.Bernal, J. D., 229.Berridge, E.M., 276.Bert, L., 66.Bhandsrkar, D. S., 9.Bhatnagar, S. S., 268, 275, 283.Biazzo, R., 158.Bidwell, G. L., 160.Bigwood, E. J., 156.Biilmann, E., 18, 19.Bircher, S. J., 23.Bircumshaw, L. L., 260.Bishop, W. B. S., 64.Bjerrum, N., 25, 281.Black, A., 200.Black, D. H., 251.Blackett, P. M. S., 247.Blaikie, K. G., 139.Blank, H. R., 43.Blench, E. A., 286.Blicke, F. F., 117.Bloch, E., 45.Bloch, L., 45.Bluh, 0.. 266.Bock, A. V., 213.Bock, O., 41.Bodansky, 206.Bode, K., 28.Bodenstein, H., 12.Boeseken, J., 64.Boehm, T., 109.Boer, J. H. de, 163.Bottger, W., 164.Bois-Reymond, E. du, 282.Boltwood, 256.Borsche, W., 93.Bosanquet, C. H., 52.Bottomley, 196.Boutaric, A., 266, 270.Bouzat, A., 51.Boyd, D.R., 117.Bozza, G., 50.Bradfield, 175, 176, 178, 276.Bradley, A. J., 224.Brady, 0. L., 112, 113, 114.Bragg, (Sir) W. H., 230.Rragg, W, L., 225, 227, 228.Braun, J. von, 62, 122, 120, 130, 132,Brauns, D. H., 69, 70.Bray, 172.Bray, M. W., 85.Eredig, G., 16, 154.Bredt, J., 96.Breimeyer, C., 54.Bridgeman, P. W., 224, 225.Briggs, T. R., 151.139.AUTHORS’ NAMES.Brill, 215.Brinley, F. J., 263.Brinton, P. M.-P., 40.Briscoe, H. V. A., 35.Britton, H. T. S., 39, 169.Brodersen, J., 283.Brodie, W. R., 152.Bronsted, J. N., 25, 26.Broglie, M. de, 2.Broom& B., 231.Brotherton and Co., Ltd., 166.Brown, 185.Brown, F. E., 278.Brown, M., 157.Brown, 8. M., 182.Brown, W. E., 168.Brukl, A., 47.Brunner, O., 131.Bruylants, P., 241.Buchanan, C., 60, 74.Buck, J.S., 133, 134.Buckmaster, 211.Budde, H., 12.Budgen, N. F., 37.Biihler, K., 139.Buffat, C., 157.Burgess, H., 14, 56.Burk, R. E., 10.Burn, 207.Burns, 201.Burt, F. P., 287.Burt, W., 72.Burton, E. F., 262.Burton, H., 143.Burton, H. W., 68.Butler, J. A. V., 17.Cahn, R. S., 122.Caldwell, R. J., 15.Callow, R. K., 104.Cambi, L., 50.Campbell, A. N., 52.Campbell, R., 75.Caplan, P., 23.Carpenter, 224.Carpenter, V. A., 60.CarriBre, M. E., 157.Casares Gil, J., 49.Cazeneuve, 156.Centnerszwer, M., 49.Chadwick, J., 246, 249.Challenger, F., 1 10.Chemie, (Mlle.) C., 284.Chapman, S., 227.Charriou, A., 168.Chaudhuri, S. G., 270.Chaudun, A., 77.Chervet, D., 168.Cheymol, J., 77.Chibnall, A.C., 192.Clark, G. L., 7.Clark, J. H., 198, 200INDEXClark, N. A., 196.Clark, R. H., 15.Clavera, J. M., 27.Clayton, W., 225.Clemo, G. R., 129, 144, 146.Clifford, 214.Clover, A. M., 64.Coe, M. R., 160.Cohen, 201.Cohen, I., 161.Cohn, E. J., 277.Colin, H., 77.Collenberg, O., 50.Collins, A. D., 110.Comber, N. M., 179.Comley, M. A., 4.Compton, 250.Compton, A. H., 1.Conant, J. B., 19, 117.Conner, S. D., 182.Conrad, M., 107.Considine, F. J., 168.Contieri, A. W., 21.Cook, J. W., 108.Coolidge, A. S., 286.Cooper, W. C., jun., 28, 239.Copaux, H., 155.Copeland, 137.Corbet, A. S., 34.Corey, R. B., 41.Coster, D., 153.Coulter, C. R., 281.Coupin, H., 69.Coutts, J.R. H., 262.Cox, 216.Crittenden, E. D., 245.Crooks, W. E., 282.Cross, C. F., 87.Crowther, E. M., 170, 262.Cruto, 205.Cumming, W. J., 159.Cummins, A. B., 195.Cunningham, T. R., 167.Curie, (Mlle.) I., 251, 254.Currie, J. E., 262.Cushny, A. R., 198.Cutter, J. O., 5, GO.Cuttica, V., 39.Cuy, E. J., 45.Czockralski, 224.Daish, 185.Dakin, H. D., 59, 217.Dale, J. K., 76.Damiens, A., 153.Daniels, F., 9, 33.Danner, P. S., 36.Dark, J., 155.Darmois, E., 59.Dauvillier, A., 2.Davieu, B., 253.Davies, E. C. H., 7.OF AUTHORS’ NAMES.Davies, G. Rf., 237.Davis, A. R., 185, 194.Davis, C. E., 278.Davison, F. R., 160.Dayhuff, W. C., 178.Dean, G., 27.Dean, P. M., 152.Debye, P., 1, 25, 228. 250.Decker, H., 127.Delaby, R., 65.Dempster, A.J., 241.Demuth, F., 276.Denis, 205.Dennis, L. M., 41.Densch, A., 182, 183.Derick, 218.Dervin, 35.Desmaroux, J., 64.D’Espine, J., 251.Desvergnes, L., 163.Dhar, N. R , 37, 269, 282.D’Hooghe, A,, 36.Dickens, 204, 205.Dickson, 203.Diedrich, A., 149, 150.Dihert, F., 266.Diepolder, E., 130.Dieterle, H., 157.Dijk, J. C. van, 165.Dijkotra, D. W., 243.Dilthey, W., 128.Dittrich, M., 111.Dodds, E. C., 161, 204, 205.Dodge, R. L., 44.Doht, R., 165.Dokan, S., 283.Domboviceanu, A., 261.Donnan, F. G., 279.Dorcas, 31. J., 28, 243.Dore, Ti”. H., 83.DorBe, C., S7.Doscr, A., 70.Douglas, G. W., 278.Downey, W. E., 46.Drushinin, D., 183.Dubrisay, R., 273.Ducheneau, 206.Duclaux, J., 259, 261.Dudley, 204, 205, 217.Duley, F.L., 183.Dumanski, A. V., 206.Dunn, F. P., 112, 113.Dunnill, S., 21.Duran, F., 287.Durand, J. F., 157.Dussik, A., 30.Dutcher, R. A., 159.Duvinage, R., 187, 204.Eadie, 203, 206, 207.Eastmm, E. D., 231.Eberstaller, H., 132.291L 292 INDEX OF AUTHORS’ XAMES.Ebert, L., 24.Ecke, A., 165.Eckerson, S. H., 191.Eden, T., 154.Egan, M. N., 78.Ehringhaus, A., 2G1.Eibner, A., 158.Eiseman, M., 23.Eisenlohr, F., 93.Elain, 224.Ellingham, H. J. T., 20.Ellis, C. D., 250, 251.Elsner, B., 106.Embden, 202, 207.Emelt.us, H. J., 46.Emster, K. van, 97.Engel, H., 107.Engelstad, A., 87.Enqledon, F. L., 191, 193.Erlach, E., 265.Errera, J., 152, 261.Evans, G. T. R., 268.Evans, J.W., 237.Evans, U. R., 260.Euler, K., 119.Epnon, L., 160.Fabre, R.. 152.Fage, W. E., 255.Fairbrother, F., 278.Fairhall, L. T., 44.Fajans, K., 164.Fnrgher, R. G., 148.Fenron, 217.Fcigl, F., 161. 1G2, 166, 167, 170.Ferguson, A., G.Fwguson, A. L., 21.Fieliter, 216.Firild, 213.Picscr, L. F., 19.Findlay, &4., 260.Fischer, 74.Fkeher, E., 63, 70.Fischcr, F., 86, 154, 172, 173.Fischer, H., 79, 122, 123, 124,Fischw, M. H., 272.Fischer, O., 141, 149.Fischer, Y., 23.Fisher, E. A., 182.Fleming, N., 255.Fleming, R., 162.Fliirscheim, B., 11 8.Foerster, K., 36.Foerster, F., 49.Folin, O., 218.Forster, M. O., 113.Forsyth, R., 147.Foster, 202, 207.Fowler, R. H., 253.Frlinkel, S., 137, 215.France, W.G., 263, 278.1 4 9Francis, G. V., 66, 186.Franz, A., 157.Fred, E. B., 190.Premery, W.. 43.Frenkel, J., 285.Presenius, L., 182.Freudenberg, E., 199.Freudenberg, K., 61, 70.E’reundlich, H., 2G0, 261, 267.Fricke, K., 35, 252.Friedrich, F., 267.Friend, H., 1G1.Fries, K., 107.Frohlich, P. K., 276.Frumkin, A., 286.Fuchs, K., 168.Fuchs, W., 106.Fiirth, R., 263, 266.Furusawn, 207.Gadamer, J., 135.Gaertner, K., 127.Gagos, K., 38.Qainey, P. L., 183.Gallagher, P. H., 188.Gallia, 215.Gangl, J., 132.Ganguly, P. B., 269.Garner, W. E., 286.Garrett, C. S., 71.Gates, 202.Gaubert, P., 230.Gault, H., 89.Gedroiz, K. K., 180, 182.Gcigcr, I€., 253.Wrnrd, L., 98.Gericlrc, W. F., 195, 196.Gerinnnn, A.F. O., 38.Gerngross, O., 277.Gerrctscn, F. C., 155.Gessncr, H., 260.Ghosh, .J. C., 24.Ghosh, S., 77.Gibbs, W. E., 225.Gibson, C. S., 143.Gilchrist, H. S., 77.Gilc, P. L., 154.Gilmour, R., 14, 57.Glasstone, S., 21, 22, 23, 159.Goldblatt, 200.Goldenberg, A. von, 154.Goldschmidt, H., 11 1, 149.Goltlschmidt, S., 119, 120, 121Golclstiick, RI., 162.Golla, H., 35.Gomberg, ll., 115, 116, 117.Goodwin, 197, 202.Gordon, N. E., 276.Gortner, R. A., 160.Gottlicb, R., 137.Gottschalk, 208.Grant, 202INDEX OF AUTHORS’ NAMES. 293Grant, N. S., 166.Greenberg, D. M., 277.Greenwald, I., 161, 201.Grey, F. T., 264.Griebel, C., 156, 205.Griliches, 302.Grimm, A., 39.Grinten, K. von der, 262.Gross, J., 161, 201, 215.Gruber, G., 129, 137.Gudden, B., 252.Guntz, A., 36.Gutbier, A., 265.Gutlohn, L., 151, 261,Gyemant, A., 285.Gyikgy, 199.€has, A.R. C., 19.5.Hahn, F. L., 163.Hahn, F. V. von, 267.Hahn, O., 254, 255, 257.Haldane, J. €3. S., 202, 203.Hall, L., 87.Halliday, E. G., 284.Hamer, (Miss) F. M., 130.Hamer, H., 161.Handovsky, H., 282.Hansen, H. M., 43.Hansman, 204.Hantzsch, A., 107, 111, 112.Hanug, J., 165.Harington, 211, 212.Harkins, W. D., 7, 23, 35, 241, 215,247, 248, 271.Harper, H. J., 155.Harris, L. J., 19, 158.Harrison, A. P., 167.Harrop, 202.Hartung, E. J., 35.Harvey, M. T., 278.Hassel, O., 164, 223, 229, 234, 235.Hasselbach, 2 11.Hastings, S., 201, 211, 212.Hatfield, W. D., 170.Haworth, R. D., 134.Haworth, W.M., 68, 71, 72, 75.Hayashi, K., 286.Hazeldine, C. E., 148.Hazelton, E. O., 156.Hedges, E. S., 15, 16.Heidel berger , 2 1 1, 2 12.Heiduschka, A., 151.Heilbron, 184, 191.Heindlhofer, K., 222.Helfer, L., 132.Helferich, B., 74.Heller, G., 109.Hendel, J. M., 166.Henderson, G. H., 252.Henderson, L. J., 211, 212, 213.Henclry, J. L., 277.Henry, D. C., 269.Herissey, H., 77.Hermans, P. H., 64.Herring, 206.Herrmann, F., 86.Hertz, G., 245.Herzberg, G., 40, 4 1.Herzenstein, A., 118.Herzner, R., 44.Heslinga, J., 157.Hess, K., 89.Hess, V. F., 253.Heuser, E., 86.Hevesy, G. von, 43.Heymann. E., 163.Heyrovskj., J., 18, 21.Hibbert, E., 160.Hibbert, H., 74.Hiebert, P. G., 33.Higley, H. P., 279.Hildebrand, J.H., 51.Hill, A. V., 200, 207, 212.Hilton, F. A., 2-13.Himwich, 208.Hinshelwood, C. N., 9, 10, 11.Hinton, C. L., 160.Hirabayashi, K., 165.Hirsch, P., 158.Hirst, E. L., 88, 89.Hissink, D. J., 155, 180.Hitchcock, D. J., 277.Hitchens, A. F. R., 257.Hison, R. M., 70.Hoagland, D. R., 178, 193, 194.Honig, M., 75.HGnigschmid, O., 29, 245.Hoffer, G. N., 182.Hoffert, D., 204.Hoffmann, G., 257.Hoffmann, H., 235.Hofmann, K. A., 45, 48, 52.Hogg, T. P., 70.Hohlfeld, E., 286.Holliday, J. A., 167.Hollins, C., 142.Holmbergh, O., 79.Holmes, H., 113.Holmes, R. S., 175.Holmes, W. C., 152.Holroyd, G. W. F., 273.Holtz, F., 128.Hopkins, 207, 216.Howard, H. C., 40.Howe, J. L., 54.Howe, J. L., jun., 54.Howland, 199.Huber, A., )Hudson, C.S., 14, 57, 69, 75, 191.Huckel, E., 25.Hiickel, W., 93.Hiittig, G. F., 34.Hughes, J., 11.Hulett, G. A., 40.Hull, 228.L294 INDEX OF AUTi-IORS’ NAMES.Hume, 200, 205.Hummelschen, W., 182.Hunnius, 183.Hunter, H., 3, 4, 61.Huttner, K., 40.Iliin, B., 286.Imci, 214.Ingold, C. K., 13, 57, 95, 106, 108.Ingold, E. H., 108, 109.Iredale, T., 285.Irion, 248.Irvine, (Sir) J. C., 66, 70, 71, 72, 77,81, 89, 186, 206.Iyer, K . R. K., 46.Jacobson, J. C., 254.Jacobson, C. A., 51.Jaeger, F. M., 243.Jiiger, G., 163.James, R. W., 223.Jander, W., 51.Janek, A., 283.Juntzen, V. T., 43.Jarman, J., 257.Jeletzky, N. P., 126.Jellinelr, K., 164, 166.Jcniie, 205.,Jet te, E. R., 222.Jilek, A., 165.Joffi., A., 236.Johansen, E.nil., 273.Johner, H., 165.Johnston, 33. H., 9.Jones, J. E., 233.Jones, J. H., 34.Jones, L. W., 46.Jordan, A., 127.Josephy, I<., 40.Joshi, S. S., 272.J ~ ~ ~ , B., 84, 85.Kahlenberg, H. H., 60.Kahlenberg, L., 60.Kahn, H. M., 19.Kann, E., 74.Kappen, H., 183.Karo, W., 12.Karrer, P., G 1 , 84, 85, 215.Karrcr, S., 9.Kassner, G., 46.Katayarna, M., 6.Kautsky, H., 40, 41.Kawamura, T., 116.Kay, 107, 202, 203, 204.Kayser, L., 164.Keefer, 203.Keelay. ‘F. C., 52.Keen, B. A., 262.Keesom, W. H., 232.Keith, E. B., 271.Kellermnnn, K., 52.Kelley, W. P., 162, 193.Kelly, 31. W., 276.Kelly, W. J., 262.Kendnll, J., 245.Kenyon, J . , 3, 61.Kerrnack, W. O., 139.Kerschbnum, M., 100.Keyes, H.E., 21.King, 14.. 133.Kinney, 200.Kintzingcr, M.; 9.Kipping, F. B., 62.Kirpiischewa, M., 236.Kirsch, G., 247, 249.Kirssanov, A. W., 126.Kisser, J . , 163.Kittler, C., 132.Kliinhardt, F., 62.Klason, P., 88.Kleeman, 1%. I)., 18.Klcmenc, A., 153.Klein, C. A., 262.Klingenfuss, M., IGG.Klisiecki, L., 127.Kneclii, E., 7.7, 160.Knibbs, N. V. S., 20.Knobel, M., 23.Knoevenagcl, E., 120.Knop, J . , 164.Kohel, M., 75.Kochendiirfer, G., G2.Kogl, F., $3.Rhlin, M., 54.Kcister, IT., 74.Kohlseliiittc,r, V., 264.Moll), A., 167.Koller, I., 71.167, 168.Kolthoff, I. M., 18, 154, 161, 163, 165,I<omatsii, S., 78.Kondo, H., 132.I<osscl, 215.Kovaril;, A. F., 255,Kraemer, E. O., 262, 2G3.Kranwr, 100.Krasc, H.J . , 36.Krnssikov, S., 64.Krntz, E., 275.Kraus, C. A., 116.Krause, E., 44.Krnuss, F., 64.Kraut, H., 38, 43.Krepolka, H., 28.Krestev, W., 166.Kroll, F., 45.Kronenberg, P., 48.Kiihn, W., 164.Kiikcnthal, H., 54.Kugelmass, 199.Kuhn, F., 216.Kuhn, K., 70, SINDEX OF AUTHORS' NAMES. 295Kunitz, M., 280, 281.Kunz, A., 76.Kurtenacker, A., 166.Kurtz, S. S., 19.Kusenack, W., 80.Ladd, W. L., 156.Laer, M. H. van, 187, 204.Laquer, 205.Laing, M. E., 272, 273, 274.LaMer, V. K., 26, 168.Lamparter, W., 113.Landman, S., 260.Lane, J. H., 160.Lang, R., 52.Lange, E., 94.Lange, H., 113.Lange, W., 51.Langmuir, 7, 17.Laporte, C. E., 166.Larson, A. T., 44.Larsson, E. L., 19.Lascaray, L., 275.Lassieur, A., 168.Latham, 203.Latshaw, W.L., 183.Lattey, R. T., 21.Lawaczeck, 204.Lawson, R. W., 253.Lawson, W., 140.Leavenworth, 215.Lebeau, P., 154.Le Blanc, 30.Lecher, H., 119.Leenhardt, C., 157.Leffmann, H., 156, 276.Leibowitz, J., 77, 81, 85.Leibowitz, L., SO.Lemmermann, O., 182.Lenher, V., 167.Levene, P. A., 62, 70, 71, 72, 74.Levschin, W. T., 6.Lewis, G. N., 21.Lewitzky, M. A., 236.Li, T. H., 50.Lichtenstadt, L., 114.Liebl, F., 96.Liebster, 215.Liesegang, R. E., 199.Lindner, J., 129.Lindner, K., 50.Ling, A. R., 80.Linhard, M., 29.Linnel, W. H., 144.Linnmann, W., 52.Lipman, C. B., 189, 193.Lipman, F., 275.Loeb, J., 280.Loeb, L. F., 260, 261.Loeb, R. F., 198.Loebel, 208.Loebenstein, F., 277.Lowenthal, H., 266, 270, 278.Loewinson-Lcssing, I?., 241.Long, 207.Longchambon, L., 59, 236.Lo Priore, G., 156.Lorenz, R., 28, 286, 287.Lorth, P., 117.Lottermoser, A., 267.Low, W., 169.Lowry, H.H., 287.Lowry, T. M., 5 , 13, 14, 56, 59, 60.Lucas, R., 236.Luce, 202.Luck, 214.Ludewig, S., 74, 78.Lueck, R. H., 9.Luff, G., 164.Lund, H., 18.Lupton, 207.Lutze, H., 157.Lynn, E. V., 65.Lyon, C. J., 188, 204.Maas, O., 33.McAlpine, R. K., 29.Macara, T., 160.McBain, J. W., 272, 273, 274.Macbeth, A. K., 82.McBurney, D., 263.McCall, A. G., 183.McCollum, 200.R'lacdonald, J., 81.McElvain, S. M., 137, 138.McGee, J. M., 67, 169, 185.McGeorge, W. T., 182.Mach, F., 161.McIntosh, 201.MacInnes, D. A., 21.Mackay, J., 82.McKenzie, A., 57, 62.Mackenzie, M.R., 282.McKeehan, L. W., 223.Maclean, I. S., 204.McLennan, 244.Macleod, D. B., 7.Macleod, J. J. R., 203, 206, 207.Madorsky, S. L., 245.Miider, H., 137.Majumdar, S. K., 267.Mameli, 189.Manchot, W., 40, 48, 166.Maquenne, 184.Marchal, (Mlle.) G., 53.Mark, H., 118, 223, 229, 231, 233,234, 235.Marker, R. E., 276.Marks, 207.Marsden, E., 249.Martin, W. S., 170.Martland, 204.Mason, M., 263.Nathews, J. H., 209, 210, 272, 279.L* 296 INDEX OFMathur, K. K., 268, 283.Matignon, C., 36.Mattson, S. E., 178.Matula, V., 164.Mauguin, C., 235, 237.Maurer, K., 77.Mauthner, 210.Maw-, W., 65.Mayer, J. L., 155.M a p , C., 166.Meerwein, H., 96, 97, 98, 99.Mehta, R.P., 114.Meis, H., 113.Meisenheimer, J., 113, 149, 150.Meitner, (Fr.) L., 250, 254.Menaul, P., 159.Mennie, J. H., 254.Menzies, R. C., 138.Merck, E., 137.Merrill, H. B., 276.Merwin, H. E., 228.Messmer, E., 89.Metz, L., 162.Meulen, H. tor, 157.Meulen, P. A. van der, 271.Meuwsen, A., 28, 29.Meyer, 257.Meyer, G. M., 70, 72.Meyer, J., 39, 101.Meyer, K., 108.Meyer, V., 111.Meyerhof, 207, 210.Michaelis, L., 163, 261.Michielsen, J., 241.Miekeley, A., 74;Miescher, K., 113.Miethe, A., 35, 248.Migliacci, D., 30, 243.Mikeska, L. A., 62.Miller, E., 285.Miller, E. C., 69.Miller, E. J., 287.Milligan, L. H., 153.Millikan, R. A., 17.Mills, W. H., 112.Milner, S. R., 23.Minaev, M., 82.Minami, 208.Mingazzini, M., 101.Mirsky, 213.Mitchell, A.D., 47.Mitchell, C. A., 159.Mizutani, M., 163.Mohr, E., 92.Moles, E., 27.Mommsen, E. T., 49.Monosson, M., 67.Monroe, K. P., 57, 69.Montgomery, 217.Mooney, M., 272.Moore, J. A,, 147.Moore, R. W., 41.Moran, W. H., 278.AUTHORS’ NAMES.Morgan, 175.Morris, 185.Morris, V. A., 269.Morrison, D. R., 88.Moser, L., 44, 47, 165.Moyle, 202.Mueller, 216.Miiller, A., 225.Muller, E., 63, 169.Muller, J., 124.Muller, J. H., 43.Muller, R., 168.Muller-Goldegg, G., 33.Mukerji, B. C., 89.Mukherjee, J. N., 267, 268, 270.Mula, I<., 153.Mulliken, R. S., 244.Murmann, E., 167, 246.Murray, C. D., 212, 281.Muzaffar, S. D., 29, 243.Myers, J. E., 15, 16.Nagaoka, H., 244.Nanji, D. R., 80, 160.Narayan, A.L., 244.Neergaard, K. von, 168.Neill, 211, 212.Nelson, J. M., 14.Nenitzescu, C., 124.Neuberg, 208, 217.Neuberger, M. C., 250.Neusser, E., 48.Newbery, E., 20, 21, 22.Newton, 194.Noble, 206, 207.Norris, J. F., 117.Norrish, R. G. W., 11, 12, 49.Northrop, J. H., 281.Noyes, A. A., 25, 26.Nicholls, F. H., 50.Nicholson, W. N., 159.Nicloux, E. H., 161.Nishida, D., 165.Nishida, K., 85.Nishikawa, H., 141.Oberhauser, F., 166.Obreimov, I., 224.O d h , S., 262.Offenbacher, M., 120.Ogburn, S. C., 54.Ogg, A., 223.Ohle, H., 71.Ohse, W., 137.Oinwna, 213.Oliver, J., 271.Oliveri-MandalB, E., 143.Olmer, L. J., 35.Omlow, 219.Osato, 211.Ostwald, W., 69, 185, 2GOINDEX OF AUTHORS' NAMES. 297Ott, H., 235.Ottens, B., 113.Owen, E.A.: 223, 255.Page, H. J., 182.Pagel, 40.Paine, €3. H., 268.Palit, C. C., 37, 162.Palkin, S., 152.Palladin, 202.Paneth, F., 287.Park, J. R., 35.Parker, F, W., 182, 194, 195.Parrish, J., 262.Parsons, 212.Parsons, T. R., 168.Partington, J. R., 35, 36, 44.Passenni, M., 109.Peterson, T. R., 56.Paton, N., 201.Patterson, J., 71.Patterson, T. S., 60, 74.Pauli, W., 260, 264, 265, 266, 267.Pauling, L., 223.Pavelka, F., 170.Pavlov, P. N., 264, 285.Paweck, H., 168.Pearson, A. R., 173.Pederaen, K., 25.Peklo, J., 69, 184.Pember, 203.Pennycuick, S. W., 14.Perin, J., 59.Perkin, W. H., jun., 129, 133, 134,Perkins, P. B., 249.Perlzweig, 203.Perreau, (Mlle.) G., 270.Perren, E.A., 95.Perron, (Mlle.), 47.Pervier, N. C., 160.Peters, K., 34.Petroff, J. R., 265.Pettersson, H., 247, 249.Peyfuss, J., 166.Pfaff, 183.Philip, J. C., 287.Phragmh, G., 221.Piaux, 207.Picard, P., 273.Piccard, J., 157.Pickard, J. A., 261.Pictet, A., 78, 82.Pilley, J. G., 245.Pittarelli, E., 163.Piutti, A., 30, 153, 243, 248.Plant, S. G. P., 146.Plowman, 114.Pohle, F., 34.Polacci, 189.Polenske, R., 93.Polonovski, Max, 143.139, 140, 141, 143, 144, 146.Polonovski, Michel, 143.Pope, (Sir) W. J., 62.Porter, A. W., 16.Potel, E., 77.Powell, W. J., 87.Prandtl, W., 39, 40.Prasad, M., 275.Preiss, J., 39.Preston, G. D., 223.Prianischnikov, M., 192.Price, P. H., 156, 159.Prichard, C. R., 10.Prideaux, E.B. R., 163, 282.Prince, A. J., 44.Pring, J. N., 19, 20.Pringsheim, H., 77, 79, 80, 81, 85.Prins, H. J., 63.Prokopp, S., 124.Pryde, J., 72.Pucker, G. W., 160.Pugh, W., 41.Pyman, F. L., 110, 147, 148.Pyriki, C., 170.Radu, A., 287.Rainer, N., 39.Ramann, E., 182.Rana, T. C., 287.Randall, M., 24.Rankin, J., 134.Ray, G. B., 208.Rayleigh, Lord, 46.Read, R. R., 74.Rebibre, G., 265.Reed, H. S., 195.Reichinstein, D., 18.Reiger, R., 283.Reimer, M., 96-Remy, H., 54, 263.Rennert, E., 78.Renscher, F., 34.Reverey, G., 93.Rhind, D., 159.Rhino, F., 61.Rhodes, J. E. W., 273.Richards, E. M., 60.Richards, T. W., 27, 28, 34.Rideal, E. K., 11, 12, 17, 23, 49, 286.Riernan, W., 271.Riesenberg, H., 69, 185.Riesenfeld, E.H., 48.Rinde, H., 263.Ripper, J., 151.Ritter, F., 40.Rius y Mir6, A., 241.Robinson, G. M., 142, 210.Robinson, G. W., 174, 183.Robinson, P. L., 35.Robinson, R., 96, 138, 139, 140, 141,Robinson, W. O., 175.Robison, 197, 198, 199, 202, 203, 204.142, 143, 144298 INDEX OF AUTHORS’ NAMES.Rogan, F., 267.Rogers, J. S., 249.Rohn, W., 50.Rojahn, C. A., 149.Roller, E. M,, 196.Rolter, G., 167.Rona, P., 198, 276.Ronsin, N., 82.Rosanoff, &‘I. A., 15.Rose, 216.Rosen, 215.Rosenhauer, E., 127.Rosenheim, A., 50.Rosenmund, K. W., 109, 132, 149.Raenthaler, L., 161, 162.Ross, J. F., 157.Ross, J. H., 156.Ross, P. A., 2.Rosseland, S., 250.R o d , G., 259, 265.Rothenbach, 257.Roy, B. C., 268.Ruhle, 30.Ruell, D.A., 72.Ruer, R., 28.Ruff, O., 36, 38, 286.Rule, H. G., 56.Runge, G., 244.Russell, A. S., 241, 256, 257.Rutgers, A. J., 32.Rutherford, (Sir) E., 246, 249, 260,Ruzicka, L., 86, 101, 102, 103.Ryan, R. W., 247.253.Sabalitschka, T., 69, 185.Sachse, H., 92.Saerens, E. P. R., 34.Saillard, E., 160.St. Maracineanu, (Mlle.), 254.Saito, S., 164.Sakuma, 209.Salisbury, H. M., 278.Salter, 175.Salzmann, R., 82.Samec, M., 82.Sameshima, J., 246, 286.Sand, H. J. S., 20, 22.Sandved, K., 50.Sarasin, J., 147, 148.Savola, G., 162.Sawyer, 185.Scales, F. M., 167.Scatchard, G., 278.Schalek, E., 260.Scheef, G., 152.Scheibe, G., 131.Schellenberg, A., 172.Schenck, R., 9.Schepp, R., 85, 172.Schemer, 228.Scheyer, H., 122, 123.Schilt,, M., 167.Schindler, H., 112.Schlee, H., 265.Schlenk, W., 53, 118.Schlenker, E., 113.Schlesinger, H.I., 53.Schleussner, C. A., 282.Schlubach, H. H., 77.Schmalz, K., 79.Schmidinger, K., 158.Schmidt, C. L. A,, 277.Schmidt, G. C., 287.Schmidt, K. O., 164.Schmidt, W., 121.Schneider, W., 127, 128.Schnoll, B., 118.Schoenmaker, P., 30.Schorigin, P., 64.Schotte, H., 78.Schrauth, W., 88.Schreiner, E., 19, 25.Schryver, S. B., 68.Schubert, M., 124.Schubnikov, L., 224.Schulov, 192.Schulte, H. S., 157.Schummer, O., 166.Schwalbe, C. G., 85, 172.Schwarz, R., 265, 285.Scott, A. W., 45.Scott, N. D., 279.Scott, T. W. W., 164.Seaborne, F. S., 166.Sedgwick, W. G., 146.Seebach, F., 127.Seide, O., 125.Seidel, F.C., 101.Seitz, F., 94.Semler, A., 266.Semmens, E. E., 69.Semmler, F. W., 100.Semper, L., 114.Sen, K. C., 269, 271, 282.Sendroy, 2 12.Shaffer, L. W., 276.Sharpe, 201.Shaw, B. D., 125.Sheppard, S. E., 284.Shipley, 200.Shirai, T., 246.Shoemaker, H. A., 65.Shohl, 199.Shrivastava, D. L., 268.Sibley, R. L., 15.Sickel, 216.Sidgwick, N. V., 104.Siecke, W., 37.Sieg, B., 48.Sieverts, A., 33.Simon, F., 207, 232, 233.Sirnons, J., 51.Simpson, S. G., 163.Simon, C. von, 223, 232, 233INDEXSindlinger, F., 161.Sjoberg, K., 81.Skinner, H. W. B., 250.Skobelzyn, D., 2, 255.Slattery, M. K., 224.Sloan, A. W., 117.Slyke, van, 211, 212.Smedt, J. de, 232.Smirnov, A., 192.Smith, D. P., 167.Smith, F.J., 117.Smith, G. F., 157.Smith, H., 200.Smith, (Miss) I. A., 57.Smith, S., 35.Smith, W., 202,203,205.Smits, A., 18, 30, 32.Smolenski, I<., 75, 83.Soames, 197, 198.Sobotka, H., 76.Soddy, F., 35, 248, 257.Someya, K., 164.Somieski, K., 42.Spacu, G., 167.Spiith, E., 124, 131, 132.Spck, J. van der, 155.Spoehr, H. A., 67, 169, 185.Stamm, A. J., 262, 272.Stammreich, H., 35.Stanley, E., 110.Starling, 205.Stather, F., 74.Staub, J., 84.Staub, M., 84, 85.Staudinger, H., 113.Stedman, E., 142, 143.Steenbock, 200.Steidler, F., 163.Steiger, A. L. v., 168.Steigerwald, C., 121.Steinberger, 198.Steinheil, M., 245.Steinkopf, W., 137.Stelzner, 13.Stephenson, G. E., 35.Stewart, G. R., 196.Stintzing, H., 153.Stobbe, H., 95.Stock, A., 37, 42.Stoddart, 213.Stoermer, R., 95.Stoklasa, J., 195.Stoll, A., 68, 184.Stoll, M., 101, 102, 103.Stoner, E.C., 2, 254.Stowener, F., 285.Strebinger, R., 158, 167.Strenk, C., 49.Stricker, P., 78, 80.Strupp, E., 86.Stuckenschmidt, A., 130.Sucharda, E., 126, 127.Suganuma, 265.OF AUTHORS’ NAMES.SugJen, S., 7, 8.Sullivan, E’. W., 115, 117.Sumner, J. B., 155.Sure, 216.Svanberg, O., 70.Svedberg, T., 263, 278, 270.Swan, R. L., 40.Swanson, C. O., 183.Sweet, S. S., 2S4.Sylvester, h’. D., 50.Szegvari, A., 260, 261, 283.T,zliali,zshi, T., 198, 20-1.Talrehara , K . , 282.Tallerman, 205.Tammaim, G., 224.Tanannev, N. A., 165.Tanimura, M., 78.‘lhnnaer. N. A., 162.Tanret, G., 124, 187.Tnpley, JI.W., 58.Tarassov, TV., 235.Tartar, If. V., 21.Taylor, 1-1. K., 180, 211, 287.Tempus, F., 75.Terada, Y., 167.Thannhauscr, 205.Thayer, T. K., 65.Thibnud, 25 1.Thiel, A , , 40, 163, 164.Tliiele, H., 41.Thiessen, P. A., 264.Thimann, TV., 257.Thomas, A. IV., 276.Thomas, J. S., 34, 41.Thomas, W., 159, 160, 260.Thompson, F. C., 53.Thompson, F. P., 75.Thoren, F., 261.Thornlep, S., 1.10.Thorpe, J. F., 13, 57, 95.Thresh, J. C., 170.Thunberg, T , 67.Tidmore, J. W., 182.Tiffeneau, M., 96.Tilling, N., 53.Timrn, J. A., 74.Toenniessen, 208.Toit, 31. S. du, 173.Tomecko, C. G., i 7 .Toms, H., 158.Topley, B., 9.Tower, 0. F., 267.Toyama, Y., 65.Traube, J., 282.Traube, W., 51.Trautz, &I., 9.Trautzl, K., 153.Travers, 47.Treadwell, JV.D., 165, 168.Tropsch, H., 63, 86, 172, 173.Trost, J. F., 182.29300 INDEX OF AUTHORS’ NAMES.Truog, E., 194.Tschitschibabin, A. E., 125, 126.Tschugaev, L., 54.Tudhope, T. M. A., 62.Tustanowska, L. v., 162.Tutton, A. E. H., 237.Ulrich, 257.Underhill, 201.Urbain, E., 43.Urbain, G., 43.Uyesugi, T., 184.Vandevelde, 214.Vanzetti, B. L., 246.Veibel, S., 19.Venable, F. P., 43.Verzijl, E. J. A. H., 168.Vesterberg, A., 100.Vickery, H. B., 193.Vila, A., 166.Vincent, 205.Vies, 214.Vollmer, W., 45.Vuillaume, M., 266.Wads, van der, 6.Wachendorff, E., 154.Wagner, 203.Wales, H., 152.Walker, 209.Walker, E. E., 56.Wallach, O., 100.Walther, E., 168.Wandenbulcke, F., 266.Warburg, O., 184, 205, 208, 209, 210,Ward, A.T., 163.Wardlaw, W., 50.Ware, A. H., 156.Wartenburp, H. von, 48.Watanabe, M., 283.Waterman, 209, 210.Watson- Williams, 137.Watts, 0. O., 152.Weatherill, P. F., 29.Weaver, W., 263.Webster, 200.Weeks, E. J., 20, 22.Weevers, T., 69, 186.Wegmann, E., 148.Weichselfelder, T., 53.Weickel, T., 118.Weigert, F., 52, 69.Weimarn, P. P. de, 259.Weinhagen, A., 85.Weinhold, R., 62.Weinmayr, I., 16.V17eiss, B., 124.211, 216.Weitz, E., 45.Wells, H. L., 28.Weltzien, W., 89Wendelmuth, G< 284.Wendt, 248.Wenzer, P., 167.Werner, A., 111, 112, 253.Werner, E., 217.Werner, S., 43.Wertheim, R., 169.Westgarth, G. C., 72.Westgren, A. F., 221, 222.Westrip, G. M., 22.Wever, F., 38.Wha, C., 261.Whinyates, L., 111.White, F. D., 124.Whiteley, 114.Whiting, 182.Whittaker, H., 87.Widdowson, W. P., 256, 257.Wiedebrauck, E., 286, 287.Wieland, H., 119, 120, 216.Wigglesworth, 202.Wigner, E., 233.Wilk, H., 39.Wilken, D., 54.Willaman, J., 160.Willard, H. H., 27, 29.Williams, A. M., 282.Williams, E. C., 287.Williams, F. A., 36.Williams, J. W., 33.Williams, R., 183.Williams, W., 182.MTillstBtter, R., 238, 43, 68, 94, 137.Winchester, J., 148.Windaus, A., 62, 93.Winfield, 207.Winkler, K., 9.Winter, 202, 205.Wintgen, R., 261, 266, 270, 278.Wohler, L., 41, 162.Wolf, C. G. L., 286.Wolf, H., 163.Wolfes, O., 137.Wolff, O., 152.Wolfram, A., 137.Wolfram, J., 158.Wolfsohn, K., 80.Wood, C. E., 4.Woodman, H. E., 191, 193.Woodrow, 202, 207.Wortmann, R., 96, 98, 99.Wulfken, F., 163.Wulf, 0. R., 9.Wyckoff, R. W. G., 220, 228, 237.Wylam, B., 75.184.Yabusoe, 205.Yajnik, N. A., 287Yardley, K., 220, 235.Yee, J. Y., 36.Yntema, L. F., 39.Youngburg, G. E., 160.Yovanovitch, D., 251.Zacharias, P. D., 283.Zakarias, L., 151.INDEX OE AUTHORS' NAMES.Zeigler, K., 118.Zemplh, G., 75, 76.Zerbe, C., 154.Zerweck, W., 149.Zintl, E., 28, 29.Zschoch, F., 95.Zsigmondy, R., 266, 276.Zyl, G. van, 21.30

ISSN:0365-6217    

DOI:10.1039/AR9242100289

出版商:RSC    

年代:1924

数据来源: RSC

摘要:

INDEX OF SUB JECTIE:Acetaldehyde, detection of, 155.Acetaldehyde - ammonia, crystalstructure of, 235.Acetoacetic acid, detection of, 156.Acetobromomaltose , 7 9.Acetone, detection of, 156.1-Acetylindazole, constitution of , 150.Acids, ionisation of, 19.fatty, sodium salts, surface ten-mixed, detection and separationsion of, 275.of, 151.Actinium, origin of, 256.Activity coefficient, 24.Adrenaline, determination of, 161.Adsorption, 285.in soil, 178.Agricultural analysis, 154.Albumin, egg-, mobilities of, 279.Alcohols, aliphatic, 62.Aldehydes, catalytic hydrogenationAlkali halides, compressibility of, 34.Alkaloids, angostura, 131.of, 62.aromatic, oxidation of, 109.metals, radioactivity of, 257.ruthenates, 54.anhalonium. See Cactus.cactus, 132.chelidonium, 135.alloys with cadmium and zinc, 37.alloys with copper, structure of,antimonide, crystal structure of,chloride, reactions of, 38.hydroxide, structure of, 38.nitride, crystal structure of, 235.oxide gels, 267.determination of, in water, 170.separation of titanium and, 164.Amino-acids, configuration of, 61,oxidation of, 216.anhydrides of, 213.determination of, 19.determination of amino- and carb-Ammonia, preparation and decom-Alloys, structure of, 221.Aluminium, atomic weight of, 28.222.223.215.oxyl-groups in, 158.position of, 44.Ammonia, oxidation of, 45.determination of, in urine, 167.Ammonium hafnium and zirconiumfluorides, crystal structure of,234.chlorotellurite, 50.n- and iso-Amygdalin, 75.Amylobiose, SO.Amylopectin, 80.Amylose, 80.Amylotriose, 80.Anaesthetics, local, 137.Analysis, agricultural, 154.electrochemical, 167.gas, 153..morganic, 16 1.organic, 155.physical, 164.water, 169.Angostura alkaloids, 131.Anhalonine, 132.Anhalonium alkaloids. See Cactus.Animal tissues, phosphates in, 197.Antimony, atomic weight of, 29.sulphide sols, coagulation of, 269.determination of, 167.Aporphine, 136.Araban, 84.b-Arabinose, halogenoacetyl deriv-Aragonite, structure of, 225.Arbatia pustuboaa, trigonelline from,Arginine, preparation and determina-Aromatic compounds, reactions of,Arsenic hydrides, 47.Arsenides, 47.Asparagine, 191.Assimilation, 184.theory of, 69.Atomic species, abundance of, 242.weights, 27.atives of, 70.128.tion of, 215.in diet, 216.106.trisulphide sols, 266, 267.separation of mercury and, 167.constancy of, 243.Austenite, structure of, 221." Auximones," 196.Azo-compounds, reduction poten-tials of, 19.30INDEX OF SUBJECTS.303Barium, preparation of, 36.Benzaldehyde, o-nitro-, oxidation of,Benzene, crystal structure of, 231.adsorption of, by charcoal, 154.intensive drying of, 30.nucleus, addition to, 106.derivatives, physical properties andconstitution of, 104.Benziminazoles, 149.Benzoic acid, salts, diffusion poten-tials and mobilities of, 282.Benzophenone, p-nitro-, oximes, 114.Berberine, 133.Beryllium benzoylcamphor, mutaro-Bismuth, crystal structure of, 223.determination of, 164, 169.109.tation of, 14, 56.suboxide, 47.determination of, 165, 166.separation of, 164.separation of copper, silver, and,phosphoric esters in, 197.168.Blood, calcium compounds in, 198.Blood corpuscles, red, electric chargeeffect of electrolytes on sus-on, 281pensions of, 271.Bone, formation of, 197.Bornyl chloride, isomerism of, 98.Boron hydrides, 37.oxide, band spectra of, 244.Bromine, atomic weight of, 28.use of, in place of iodine in analysis,166.Brucine, 143.cycZoButane derivatives, 94.Cactus alkaloids, 132.Cadalene, 101.Cadinene, structure of, 101.Cadinol, 102.Cadmium, isotopes of, 239.alloys with aluminium and zinc,detection of, 161.separation of mercury and, 167.Czsium chloride in microanalysis,determination of, 167.Calcite, structure of, 225.Calcium, effect of, on plant growth,37.161.195.in blood, 198.carbide, dissociation of, 36.oxide, action of nitrogen peroxidecyanamide, formation of, 36.silicocyanamide, 41.detection of, 163.determination of, in water, 170.on, 36.Calomel. See Mercurous chlorideunder Mercury.Camphane, 2 : 2-dichloro-, isomerismof, 98.Camphane hydrochloride, isomerismof, 98.Cancer, glycolysis in tissues in, 208.Carbazoles, 143.Carbohydrates, 66.in plants, 185, 187.effect of phosphates on metabolismCarbolines, synthesis of, 140.Carbomethoxy glycerol carbonate, 65.Carbon, atomic weight of, 27.vapour pressure of, 40.tervalent, compounds with, 115.tetra-bromide and -iodide, crystalstructure of, 236.monoxide, absorbents for, 40, 153.reduction of, 63.dioxide, assimilation of, 184.absorption of, by leaves, 67.determination of, 169.ture of, 227.of, 202.Carbonates, rhombohedral, struc-determination of, 157.Carbonyl chloride, determination of,Casein, physical chemistry of, 277.Catalysts, metallic, heats of adsorp-Cataphoresis, 261.Cellobiase, 85.Cellodextrin acetate, 90.Cellulose, structure of, 91.154.alkali compounds of, 277.tion of gases by, 287.esparto, 88.spruce wood, 88.cuprammonium solutions of, 89.methylation of, 90.Cellulose A, and its triacetate, 89.Cementite, crystal structure of, 221.Cereals, polysaccharides in, 186.Cerium, isotopes of, 241.and its alloys, absorption ofsalts, 39.adsorption of gases by, 286.hydrogen by, 33.Charcoal, active, 287.Chelidonine, 135.Chelidonium alkaloids, 135.Chemical constitution and rotatorydispersion, 2.periodicity of, 15.reactions, mechanism of, 9.Chloral hydrate, detection of, 156.Chlorine, atomic weight of, 28.photochemical combination ofhydrate, 51.monoxide, thermal decompositionhydrogen and, 52.of, 10304 INDEX OE’Chlorine :-Hydrochloric acid, solid, crystalChlorides, determination of, 169.Hypochloritos, determination of,structure of, 233.166.Chloroform, detection of, 156.Chlorophyll, action of, 184.Chromium, preparation of, 50.Chromic oxide sols, 266.Chromic acid, determination of, 169.Cinnamic acids, preparation of, 108.Clays, nature of, 175.flocculation of suspensions of, 176.Coagulation, 2 6 7.Coal, formation of, 85.Cobalt, atomic weight of, 28.detection of, 162.Cocaines, 137.Cod, insulin from, 205.Colloids, chemistry of, 259.coagulation of, 267.colour of, 263.reciprocal precipitation of, 270.swelling and gelation of, 283.influence of, on gaseous reactions,protective, 260.solutions, hydrogen-ion concen-260.Colloidal particles, size of, 362.tration in, 275.ageing of, 260.viscosity of, 260.Colouring matters, adsorption of, 287.Copper, atomic weight of, 28.alloys with aluminium, crystalhydroxide, colloidal coagulationCuprous oxide, action of nitrogenperoxide on, 34.detection of, 162.determination of, 167.determination of, in water, 170.separation of bismuth, silver, and,Creatinine, determination of, 161.Cryptopine, structure of, 133.Cryptopyrrolecarboxylic acid, 124.Crystals, structure of, 220.production of large single, 224.deformation and strength of, 236.Cusparine, 13 1.Cysteine, autoxidation of, 209.structure of, 222.of, 268.determination of, 165.168.Deamination, 217.Decahydronaphthalenes, isomeric, 93.Decahydro-,%naphthols, oxidation of,Dextrose, oxidation of, 75.93.biological degradation of, 206.IUBJECTS.Diastase, determination of, 161.Diazo-compounds, aliphatic, asym-metry of, 62.‘5 : 5’-Di( 3” - carbethoxy - 4” - methyl-2” - pyrrylmethy1)-4 : 4’ - dicarb-ethoxy-3 : 3 -dimethyl-2 : 2’ - di-pyrrylmethene, 123.Dicarbomethoxy glycol, 65.Digermane, 42.Dihexosan, 80.4 : 6-Diketo-l : 2-divinylene-l : 4 : 5 : 6-tetrahydropyrimidine, 126.a-Dilinoleninza-linolin bromide, 158.2 : 4 - Dimethylpyrrole - 3 - carboxylicacid, ethyl ester, condensation ofglyoxal with, 123.1 : 4 - Diphenyl- 2 - methylpiperazine,resolution of, 62.Diphenylnitric oxide, 120.Diphenylpicrylhydrazyl, 1 19.Dipyrrylmethenes, 122.2 : 2’-Diquinolylamine hydrochloride,Disaccharides, 77.Disintegration by a-particles, 246.Dispersion, rotatory, and chemicalDolomite, structure of, 228.Drying, intensive, effect of, 30.130.const,itution, 2.Earths, rare, salts of, 39.Eka-manganese, 52.Electrochemical analysis, 167.Electrode potentials, 16.Electrodes, 168.irreversible processes at, 19.quinhydrone, 18.17.Electrolytes, 23.Electromotive force, formula for,Electron affinity, 17.Element of atomic number 61, 39.Elements, disintegration and trans-mutation of, 246.Elodea canadensis, effect of phos-phates on respiration of, 188.Emulsions, 271.size of particles in, 263.Equilibria, membrane, 279.Eserethole, 143.Eserine, derivatives of, 142.Esters, reduction of, 63.10 : 21-Ethano-5 : 10 : 16 : 17 : 18 : 19-hexahydroacrindoline, 146.Ethers, reactions of, 64.Ethyl ether, preparation of, 64.sulphate, preparation of, 65.Ethylglycerol triformin, 65.fl-Eucaines, 138.Eudalene, 103.Eudesmol, 103.Evodiamine, formula for, 142INDEX OF TJBJECTS.305Farnesol, 100.Fat, synthetic, from olive-oil, 77.Fats, acetyl value of, 158.Ferricyanides, determination of, 166.Ferrocyanides, determination of, 159.Filter, stream-line, 261.Flocculation meter, 262.Fluorine, preparation of, 5 1.Hydrofluoric acid, preparation of,Hydrofluosilicic acid, 51.determination of, in organic com-51.pounds, 157.Foams, 286.Formaldehyde, synthesis of, 67.synthesis of sugars from, 66.fermentation of, by osmium, 63.assimilation of, by green plants,detection of, 155.determination of, 169.Fructose.S e e LEvulose.Fructosediacetone, 70.Fruits, pectins in, 82.Fruit juices, gelation of, 284.Fumes, chemical, size of particles in,Furfuraldehyde, determination of,185.263.160.&Galactose, structure of, 73.5-Galactosido-mannose, 78.Galegine, 124.Galipine, 13 1.Gallium, isotopes of, 239.Gas analysis, 153.Gases, adsorption of, by charcoal,Gelatin, properties of, 277.Gels, 283.Germane, 42.Germanium, atomic weight of, 28.preparation of, and its hydrides, 4 1.isotopes of, 239.Glass, adsorption of gases by, 287.Glucose. S e e Dextrose.Glucosediacetone, 70.Glucosides, 75.6-Glucosido-rnannose, 78.Glycerol, determination of, 158.Glycogen, 82.Glycols, isopropylidene ethers of , 64.Glycolysis in cancer tissues, 208.Glyoxal, condensation of ethyl 2 : 4-dimethylpyrrole - 3 - carboxylateand, 123.Glyoxaline derivatives, 147.Gold, formation of, in mercury arclamps, 35.colloidal, 264.sols, coagulation of, 267, 269.alloys with silver, structure of, 223.286.isoGranatoninecarboxylic acid, ethylester, synthesis of, 138.Graphite, structure of, 228.Haemoglobin, 211.derivatives, spectra of, 213.Hafnium in zirconium minerals, 43.Halogens, determination of, 157.Harmaline, constitution of, 141.apoHarmine, synthesis of, 140.H e l i x pomatiu, lichenase from, 84.Heteroxanthine, preparation of, 148.Hexachlorodisiloxan, 41.Hexachlororuthenic acid.S e e underHexahydrohomophthalic anhydrides,Hexamethoxydisiloxan, 41.Hexaphenyltetrazane, 119.Hexosephosphates in muscle, 202.Histidine in diet, 216.Homochelidonine, 135.Humic acid,,!72." Humogen, 196.Hydrazine, oxidation of, 45.Hydriodic acid. S e e under Iodine.Hydriodoquinine, 132.Hydrocellulose, 8 9.Hydfofluoric acid. S e e under Fluor-ine.Hydrofluosilicic acid.S e e underFluorine.Hydrogen, absorption of, by ceriumand its alloys, 33.photochemical combination ofchlorine and, 52.peroxide, properties of, 33.catalytic decomposition of, 16.separation of ozone from, 153.mination of, 152.Ruthenium.isomeric, 93.Hydrogen-ion concentration, deter-Hypochlorites. S e e under Chlorine.Hyponitrites. S e e under Nitrogen.Hypophosphorous acid. S e e underin colloidal solutions, 275.Phosphorus.Indazoles, 149.Indicators, 163.Indoles, catalytic hydrogenation of,Indole derivatives, 138.Inorganic analysis, 16 1.Insulin, 204.Interfacial tension, 273.Iodine :-position of, 11.139.Hydriodic acid, thermal decom-Ionium, life period of, 257.Iron, crystal structure of, 221, 233.isotopes of, 239306 INDEX OF SUBJECTS.Iron compounds in biological oxida-tion, 209.oxide sols, 267.Ferric hydroxide sols, coagulationof, 269.Steel, crystal structure of, 221.spectra of, 244.table of, 240.separation of, 246.Isotopes, 238.Jellies, contrasted with gels andcurds, 274.Kinetics of reaotions, 9.“ Lactacidogen,” 202.isolactal, 78.Lactic acid in muscle, 207.Lactosan, 78.Lactose, determination of , 160.Lzevulosan, 187.Lzevulose, halogenotetra-acetyl deriv-atives of, 69.Lanthanum salts, 39.Lead, atomic weight of, 30.crystal structure of, a t absolutetetrachloride, solubility of, in benz-fluoroiridiate 63.phosphates, 44.determination of, in water, 170.Leaves, absorption of carbon dioxideLichenase, 84.Lichenin, 84.Liesegang phenomena, 282.Lignin, 85.determination of, 160.Lignin, bromo-, chloro-, and nitro-,87.Lignosulphonic acid, 87.Linseed oil, analysis of, 158.Liquids, adsorption and interfacialtension in, 272.surface energy of, 6.mixed, of constant boiling point,separation of, 151.hydride, electrolysis of, 33.sulphide, 34.zero, 233.ene, 44.by, 67.Lithium halides, hydrates of, 34.Lophophorine, 132.Magnesium perchlorate trihydrate asan absorbent in analysis, 157.silicide and stannide, structure of,223.detection of, 163.Magnesium, determination of, 166.determination of, in water, 170.Malic acid, uranyl salt, 59.y-MaIic acid, resolution of, 59.Z-Malic acid from sucrose, 59.Malt extract, enzymes of, 85.Maltose, synthesis of, 77.Manganese and its alloys, depositionof, 52.Manganous amide, 45.Permanganates, standardisation ofsolutions of, 166.a-Mannose, 7 1.Martensite, structure of, 222.Mastic sols, cataphoresis of, 2G1.Matrine, 132.Membrane equilibria, 279.Mercury, activated, 16.transmutation of, into gold, 248.action of nitric acid on, 37.alloys (amalgams), use of, in volu-metric analysis, 164.Mercurous chloride, structure of,235.determination of, 168.separation of arsenic and, 167.separation of cadmium and, 167.Mesothorium-2, P-ray spectrum of,Mesoxmono-p-tolylamide oximes, 114.Metals and their alloys, crystal251.structure of, 221.rate of solution of, 15.activated, 15.of the ammonium sulphide group.separation of, 165.colloidal, preparation of, 263.detection of, by emission spectra,Metaldehyde, structure of, 235.Methoxychelidonine, 135.Methyl ethyl sulphate, 65.y-Methylgalactoside, 72.P-Methylglucoside, preparation of,77.d-Methylmannoside, tetra-acetyl de-rivatives of, 76.y -Met h ylmannoside, 72.1 -Methylpyrrolidine, preparation of,122.Mie effect, 261.Minerals, weathering of, 174.Molybdenum alloys with tungsten,152.structure of, 223.salts, 50.determination of, 165.Molybdomalates, 59.Monosaccharides, 69.Moss, Iceland, lichenin from, 84.Muscle, synthesis and hydrolysis oflactic acid in, 207.Mutarotation, 13, 56.hexosephosphates by, 202INDEX OFNeodymium, isotopes of, 241.salts, 39.Nickel hydrides, 53.hydroxide gels, 266.detcct'ion of, 162.Night-blue, colloid nature of, 267.Niton, radioactive constant of, 254.Nitrogen, atomic weight of, 27.atoms, disintegration of, 247.bivalent, compounds with, 119.fixation of, by green plants, 189.monoxide (nitrous oxide), structurethermal decomposition of, 10.peroxide, action of calcium oxideaction of cuprous oxide on, 34.pentoxide, thermal decompositionof, 9.oxides, analysis of, 153.Nitric acid, detection of, 163.Nitrates, utilisation of, by plants,determination of, 169.determination of, in soils, 155.Nitrous acid, detection of, 163.Hyponitrites, preparation of, 45." Nitrone," 11 1.Nitroxan, 45.d-y-Nonanol, rotation of aliphaticethers of, 3.of solid, 232.on, 36.190.n-alkyl ethers of, 61.Oils, cataphoretic mobilities of, 272.acetyl value of, 158.Oleic alcohol, structure of, 65.sodium salt, migration and electro-osmosis of.273.Olive oil, synthetic fat from, 77.Optical activity, 55.Organic compounds, optical activityrotatory dispersion of, 2.identscation of, by fluorescence,analysis of, 156.of, 55.152.Orientation, 110.Osazones, preparation of, 75.Osmium, octavalency of, 54.hydroxytrichloride, 54.detection of, 162.Overvoltage, 20.Oxalic acid, structure of, 235.Oxidation, biological, iron in, 209.Oximes, isomerism of, 111.Oxydisilin, 40.Oxygen, univalent, compounds with,120.Oxygenase, 188.Ozone, preparation of, and its vapourmessure. 48.seljaration' of hydrogen peroxidefrom, 153.Papaveraldine, 135.Parachor, 8.Particles, settling of, 263.long-range, from radioactive sub-a-Particles, capture and loss ofdisintegration of elements by, 246.stances, 249.electrons by, 252.Pectic acid, 83.Pectin, structure of, 84.sols, gelation of, 284.Pectins, 82.Pectose, 83.$-Pelletierine, synthesis of, 138.Pentachlororuthenious acid.SeePentat,hionic acid. See under Sul-Periodic system, 241.Periodicity of reactions, 15.Permanganates. See under Man-ganese.Peroxydase, 188.Phenols, identification of, 152.2 -/3-Phenylethyltetrahydropyran, 126.8-Phenylglyoxaline7 nit.ration of, 110.Phenylhalogenoacetic acid, Z-menthylPhosphine. See Phosphorus tri-Phosphorus, oxidation of, 45.trihydride, decomposition of, 9.pentoxide, metastability of, 32.Phosphoric acid, determination of,Phosphates in animal tissues, 197.Phosphorous acid, active, 47.Hypophosphorous acid, oxidationPhotosynthesis, 66, 184.f l - Phthalimino - fl - phenylpropionicPhyllopyrrolecarboxylic acid, 124.Physical properties in relation toconstitution, 104.Piezo-electricity, 236.Plants, chemistry of, 184.growth of, and soil acidity, 182.feeding power of, 194.asparagine in, 191.calcium in, 195.soluble glucosides in, 77.proteins in, 190.determination of sugars in, 159.green, nitrogen fixation of, 189.Plant parasites, influence of hydro-Platinum, determination of, 166.Platinumammines, 54.Polarisation, 20.Polonium, radioactive constant of, 254.a-rays of, 251.under Ruthenium.phur.esters, racemisation of, 57.hydride.166.of, 47.acid, resolution of, 61.gen-ion concentration on, 276.roots, absorption by, 193308 INDEX OFPolysaccharides, 79.Potassium ammonoaluminate andammonomanganite, 45.chlorate, reaction of gaseous am-monia with, 52.fluoroiridiate, 53.fluoroplatinate, 53.pennanganate, oxidation by, 52.pyrosulphate, 50.double cyanides, 34.Potentials, cataphoretic and mem-Praseodymium salts, 39.Precipitation, periodic, 282.Proline in diet, 216.cycZoPropane, isomeric change of, 9.Proteins, 214, 277.hydrolysis of, 214.particles in solutions of, 280.in plants, 190.Protoac tinium, radioactive constantof, 254.Protopectin, 83.Prulaurasin, 75.Purple of Cassius, 35.Pyrazoles, 149.Pyridine, determination of, 161.bases from acetylene, 125.derivatives, 125.methides, 127.Pyridopyrrole, 12 6.Pyrites, desulphurisation of, 53.Pyrosulphates.See under Sulphur.Pyrrole derivatives, 122.Pyrrole-red sols, 267.brane, 280.oxide, 40.Quinhydrone electrode, 168.Quinoline derivatives, 129.isoQuinoline derivatives, 132.Quinones, reduction potentials of, 19.2 : 3-Quinoquinoline, 130.Racemic alcohols, resolution of, 62.Radicals, free, 115.Radioactive constants, 253.elements, structure of nuclei of,250.periodic behaviour of, 242.from, 249.257.substances, long-range particlesRadioactivity of the alkali metals,Radium, radioactive constant of, 253.Radium-B and -C, number of y-raysRadium-C, 8-ray spectrum of, 251.Radon.See Niton.Raffinose, determination of, in sugars,emitted from, 255.radioactive constant of, 254.160.SUBJECTS.Rays, Rontgen, scattering of, 1.a-Rays, range of, 251.?-Rays, absorption and scattering of,Refractive index from crystal struc-Resorcinol, detection of, 156.Ricinoleic acid, sodium salt, inRickets, 200.Rings, strainless, theory of, 92.Ruthenium chlorides, 54.Ruthenates, 54.Hexachlororuthenic acid, 54.Pentachlororuthenious acid, 54.Tetrachloro-oxyruthenic acid, 54.detection of, 162.254.scattering of, 2.ture, 227.emulsions, 27 1.isoSaccharosan, 78.Salicylic acid, salts, diffusion poten-tials and mobilities of, 282.Sanguinarine, 135.Selenium, crystal structure of, 224.colloidal, 265.separation of tellurium and, 167.Selinene, 103.Sesquiterpenes, structure of, 99.Silicon, isotopes of, 234.nitride, band spectrum of, 244.dioxide (silica) gels as adsorbents,Silicic acid, colloidal, 263.Silk fibroin, structure of, 215.Siloxen, 40.Silver, isotopes of, 239.fulminating, 35.sols, 265.alloys with gold, structure of,223.bromide, films of, 35.nitride, formation of, 35.determination of, 168.separation of bismuth, copper, and?electrical conductivity of, 276.287.168.Soaps, 273.Soap solutions, nature of, 272.Sodium, atomic weight of, 27.gelatinate, effect of salts on pro-perties of, 280.pyrosulphate, 50.thiosulphate, preparation of, 49.detection of, 163.Soil, acidity of, 178, 182.adsorption in, 178.base exchange in, 179.humic acid in, 172.inorganic colloids of, 174.lime requirements of, 183.analysis of, 154.Solution, theories of, 24INDEX OF SUBJECTS.309Sophorn anyust$olin, matrine from,Spectra of isotopes, 244.Stannic acids. See under Tin.Starch, constitution of, 79.synthesis of, in cereals, 186.effect of light on hydrolysis of, 69.determination of, 152.132.Steel. See under Iron.Stereoisomerism, 92.2-Stilbazole, reduction of, 125.Strontium, preparation of, 36.Strychnine, 143.Succinic acid, and its anhydride andSucrose, 77.GoSuerose, 78.Sugars, photochemical synthesis of,66.rotation of, in presence of hydro-chloric acid, 70.mutarotation of, 13, 67.nomenclature of, 79.efficiency of, in relieving insulinsymptoms, 206.determination of, 159.determination of, in urine, 160.y-Sugars, 74.Sugar-beet, pectin from, 83.Sugar carbonates, 71.Sulphur, rhombic crystal structureof, 233.activation of , 49.sols, 265.combination of, with hydrogenDisulphur &fluoride, 49.t r i o d e , intensive drying of, 30.Sulphurous acid, distinction be-tween thiosulphuric acid and,163.imide, structure of, 235.rotation of, 4.and oxygen, 11.Sulphates, determinat’ion of, 169.Pyrosulphates, preparation of, 49.Hyposulphites, determination of,Thiosulphuric acid, 49.acid and, 163.166.distinction between sulphurousThiosulphates, determination of,in presence of sulphites, 166.Pentnthionic acid, 49.determination of, 151.Surface energy, 5.Surface tension, relation betweenSwelling, effect of electrolytes on,“ Syntliol,” 63.density and, 6.283.Tannins, detection of, 156.determination of, 159.Tanning, hydrogen-ion concentrrt-Tartaric acid, rotatory dispersion of,rotation dispersion and salts of, 59.determination of, 158.Teeth, formation of, 197.Tellurium, crystal structure of, 224.dichloride and oxychloride, 50.separation of selenium and, 167.Tetany, 200.Tetrachloro-oxyruthenic acid.See?cnder Ruthenium.Tetrahydroanhydro - $ - berberines, 13 3.Tetrahydroisoquinoline, 132.4-Teirahydroquinolone, 129.Tetrametliylmannonolactones, 72.Tetramethyl y-mannose, 72.Tetraphenyl~iydrazine, 1 19.Thallic selenates and sulphates, 38.Thiocyano-groups, orientating effectThiophen-atropina and -cocaine, 137.Thiosulphuric acid. See under Sul-Tin, spectra of isotopes of, 244.Titanium, separation of aluminiumand, 164.Tomato plants, reduction of nitrates,by, 191.Trigerinane, 42.Trigonelline, 128.Trihexosan, 80.Triphenylcarbinol, reaction of phos-phorus trichloride with, 117.Triphenylmethyls, 115.Tropane derivatives, 137.Trusillic acids, 95.Trusinic acids, 96.Tungsten, elcctrodcposition of, 60.tion in, 276.4, 236.of, 110.phur.Stannic acids, 43.detection of, 162.alloys with molybdenum, structureof, 223.Ultrafiltration, 151, 261.Uranium, preparation of, 50.Uraniuin-I and -11, a-raps of, 252.Uraniurn-X, @-ray spectrum of, 250.Uraniutn-2, 255.Uric acid, 218.Urine, determination of ammonia in,determination of sugars in, 160.disintegration series of, 256.determination of, 167.167.Vanadium pentoxide sols, 266.Viscometer, capillary, 260.Vitamin-D, 200.Voluines, moIecUIar, comparison of, 8310 ISDEX OF SUBJECTS.Wagner rearrangement, 96.Water analysis, 169.Wood, bacterial decay of, 86.spruce, cellulose from, 88.Xylan from cellulose, 89.Yttrium, atomic weight of, 29.Zinc alloys with aluminium and cad-mium, 37.hydroxide, structure of, 38.detection of, 161.determination of, 168.Zingiberine, 102.Zirconium, atomic weight of, 43.isotopes of, 239.detection of, 162

ISSN:0365-6217    

DOI:10.1039/AR9242100302

出版商:RSC    

年代:1924

数据来源: RSC