摘要:

ANNUAL REPOETSO N THEPROGRESS O F CHEMISTRYANNUAL REPORTSON THEPROGRESS OF CHEMISTRYF O R 1 9 1 9 .ISSUED BY THE CHEMICAL SOCIETY.A. CHA~TON CHAPMAN.A. W. CROSSLICY, C.M.G., D.Sc.,F. R.S.F. R. S.Sir JAMES J. DOBBIE, M.A., D.Sc.,M. 0. FORSTER, D.Sc., Ph.D., F.R.S.T. A. HENRY, D.Sc.J. T. HEWITT, MA., D.Sc., Ph.D.,F. R.S.C. A. KEANE, D.Sc., Ph.D.T. DL LOWRY, O.K.E., D.Sc , F.R.S.G. T. MORGAN, D.Sc., F R.S.J. C. PHILIP, O.B.E., D.Sc., 1’h.D.A. SCOTT, M.A.,P.Sc., F.R.S.5. SMILES, O.B.E., D.Sc., F.E.S.J. F. TIIORPE, C.B.E., D.dc., Ph.D.,F. R. S.&hifax :J. C. CAIN, D.Sc.Sub-- Qbifor :A. J. GREENAWAY.&uhhnit Snb-dFbitar :CLARENCE SMITH, D.8c.E. C. C. BALY, C.B.E., F.R.S.G. I ~ A R G E R , M.A., D.Sc., F.R.S.T. V.BARKER, M.A., B.Sc.H. M. DAWSON, D.Sc., Ph.D.J. C. IRVINE, D.Sc., Ph.D., F.R.S.C. AINSWORTH MITCHELL, M.A.E. J. RUSSELL, O.B.E., D.Sc., F.R.S.A. W. STEWART, D.Sc.R. ROBINGON, D.SC.Vol. XVI.LONDON :GURNEY & JACKSON, 33 PATERNOSTER ROW, E.C. 4.1920PRINTED I N OREAT BRITAIN BXRICHARD CLAP A N D SOIVS, LIMITED,BBUNSWICK STBd&ET, STAMFORD STREET, B.E. 1.AND BUNGAY. BUFFOLKCONTENTS.PAGEGENERAL AND PHYSICAL CHEMISTRY. By H. M. DAWSON, D.Sc.,P h . D . . . . . . . . . - . . . 1INORGANIC CHEMISTRY. By E. C. C. BALY, C.B.E., F.RS. . . 2655Part II.-HOMOCYCLIC DIVISION. By R. EOBINSON, D.Sc. . . . 87Part III.-HETEROCYCLIC DIVISION. By A. W. STEWART, D.Sc. . . 104ANALYTICAL CHEMISTRY. By C. AINSWORTH MITCHELL, M. A.. . 127PHYSIOLOGICAL CHEMISTRY. By G. BAKGER, M.A., D.Sc., F. R.S. . 147AGRICULTURAL CHEMISTRY AND VEQETARLE PHYSIOLOGY.BYE. J. RUSSELL, O.B.E., D.Sc., F.R.S. . . . , . 171CRYSTALLOGRAPHY. By T. V. BARKER, M.A., B.Sc. . . . , 197ORGANIC CHEMISTRY :-Part ~.-ALIPHATIC DIVISION. By J. C. IRVINE, D.Sc., Ph.D., F.R.S. ABBILEVIATED TITLE.A . . . . .Acad. S'ci. Fennicae .Ayric. J. India . .Agric. Res. Inst. Pz~srcAnzer. Chcm. J. . .Amer. J. Rot. . .Amer. J. Pharm .Amer. J. Physiol. .Amer. J. Sci. . .Anal Pis. Quim. .Anal@ . . .AnnaEen , , .Ann. Bot. . . .Ann. Chim. . .Ann. Chiin. nnal. .Arm. Inst. Pastew .Ann. Physik . .Ann. Physique . .Ann. Report . ,AnnaZi Chim. App1.t .Apoth. &it. . .Arch. Ntferland. PhysiolArch. Phnrin.1 ..Arch. Sci. phys. nnt.Arkiv. Ketn. Afin. Geol.Atti R. Accad. Limei .Ber. . . . .Ber. Deut. hot. Ges. .Ber. Deut. pharm. Ges.Biochem. J. . .Biochem. Zeitsch. .Biol. Zentr. . .Boll. chim. farm. ,Brit. Pat. . . .Bull. Assoc. Chim. Sucr.Bull. Soc. chim. . .Bull. Soc. chim. Belg. .Bull. Son. frang. Min. ,Chem. News . . .Chem. Weekbtad . .Chm. Zeit. . . .Chem. Zentr. . . .REFERENCES.TABLE OF ABBREVIATIONS EMPLOYED IN THEThe year is not inserted in references to 1919.JOURNAL.Abstracts in Journal of the Chemical Society."Acta Societatis S :ientiarum Fennicae.Agrjciiltural Journal of India.Agricultural Research Institute, Pusa.Amerit,an Chemical Journal.American Journal of Botany.American Journal of Pharmacy.American Jourtial of Physiology.American Journal of Scienoe.Anales de 1% Sociedad Espaiioia Fisica y Quimica.The Analyst.Justus Liebig's Annalen der Chemie.Annals of Botany.Annales de Chimie.Annales de Chiinie snalytique appliquee iL l'hdustrie,Annales de 1'Institut Pasteur.Annalen der Physik.Annales de Physique.Annual Reports of' the Chemical Society.Annali di Chimica Applicata.Apotheker-Zeitung.Archives NBerlandaises ds Physiologie de l'homme etcles animaus.Archiv der Pharmazie.Archives des Sciences physiques e t naturelles.Arkiv for Icemi, Mineralogi och Geologi.Atti della Keale Accademia dei Lincei.Berichte der Deutschen Uhemischen Gesellschaft.Berichte der Deutschen botmischen Gesellschaft.Berichte der Deutschen pharmazeutischen Gesell-The Biochemical Journal.Riochemische Zeitwhrift.Riologisches Zentralblatt.Bolletino chimico farmaceutico.Hritish Patent.Bulletin de l'bssociation des Chimistes de SucrerieBulletin de la Socikt6 chimique de France.Bulletin de la SociAt6 chimique de Belgique.Bulletin de la SociAt6 franpise de Minhalogie.Chemical News.Ch emisch Weekbl ad.Ohemiker Zeitung.Chemisches Zentralblatt.?A I'Aqriculture, B la k'harmacie et h la Riologie,schaft.e t de Distillerieviii TABLE OF ABBREVlATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.Campt.rend. . IConzpt. rend. Soc. biol.Gazxetta . . .Geol. Mag. . . .Heh. Chzm. Acta .J. Agric. Res. . .J. Agric. Sci. . .J. Anzcr. Chem. Soc. .J.Biol. Chem. . .J. B d , Ayric. . .J. Franklin Inst. .J. Ind. Eng. Chem. .J. Landw. . . .J. Phnrm. Chim. .J. Pharm. Expt. Ther.J. PF,ysawl Chem. ,J. Physiol. . .J. pr. Chem. . .J. Soc. Chem. had. .J. Tokyo Chem. Soc. .J . Wc~shington Acad. Sci.Koll. Chem. BeihefLe .D.R.-P. . , .Kolloid Zeitsch. . .Kongl.. Landtbruks- Akad.Handlingar . . .Lanclw. Juhrb. . . .Landw. Versue?-Stat. .Lunds. Unz'v. Arrskr.Mm. CoEl. Sci. Kyat6 .Met. and Chem. Eng.Min. Hag. . . .Monatsh. . . . .Munch. Med. Woch. , .Nachr. Gcs. Wiss. Gottingen.Ned. Tiidschr. o. Genccsk. .Nuovo Cim. . . .Pjliiger's Archiv . . .Pharm. J. . . .Pharm. Weekblctcl . .Pharcm. Zentr. -h. . .Phil. Mag. . . ,Phil. Trans. . . .Physical Reo. . . .Physikal.Zeitsch. . .Proc. Amer. Physiol. SOL. .Proc. Camb. Phil. S'oc. ,Proc. K. Akad. Wetensch.Amsterdam. . . ,Proc. Nut. Aead. Sci. . .Proc. Roy. Irish Acad. ,JOURNAL.l'Acad6mie des Sciences.Soci4tB de Riologie.Comptes rendus hebdomadaires des SOances deComptes rendus hebdomadaires de Seances de laDeutsches Reichs-Patent.Gazzetta chimical italiana.Geological Magazihe.EIelvetica Chimica Acta.Journal of Agricultural Research.Journal of Agficultural Science.Journal of the American Chemical Society.Journal of Biological Chemistry.Journal of the Board of Agriculture.Journal of the Franklin Institute.Journal of Industrial and Eugineering Chemistry.Jouriial fur Laudwirtschaft.Journal de Pharmacie et de Chimie.Journal of Pharmacology and Experinicntal Thera-Journal of Physical Chemistry.Journal of Physiology.Journal fur praktische Chemie.Journal of the Society of Chemical Industry.Journal of the Tokyo Chemical Society.Journal of the Washington Academy of Sciences.Kolloidchemische Beihefte.Ilolloid-Zeitschrift.llongl.Landtbruks-Akademiens Handlingar ochTidskrift.Landwirtschaftliche Jahrbiicher.Die landwirtschaftlichen Yersuchs-Stationen.Lunds Universitets Ars-skrift.Memoirs of the College of Science, Kyoto ImperialMetallurgical and Chemical Engineering.Mineralogical Magazine and Journal of theMonatshefte fur Chemie und verwandtg Theile ariclererMunchener Medizinischer Wochenschrift.Nachrichten von der Konivlichen Gesellscha ft derNederlandsch Tijdschrift voor Geneeskunde.I1 Nuovo Cimento.Archiv fiir die gesammte Physiologie des Menschenund der Thiere.Pharmaceutical Journal.Pharmaceutisch Weekblad.Pharmazeutische Zentralhalle.Philosophical Magazine (The London, Edinburgh andPhilosophical Transactions of the Royal Society ofPhysical Review.Physiknlische ZeitschriftProceedings of the American Physiological Society:Proceedings of the Cambridge Philosophical Society.Koninklijke Akadeniie van Wetenschappen te Amster-dam.Proceedings (English version).Proceedings of the National Academy of Sciences.Proceedings of the Royal Irish Academy.peutics.University.Mineralogical Society.Wissenschaften.Wissenschaften zu Gotzngen.Dublin).LondonTABLE OF ABBREVIATZONS EMYmYED IN TEE REFERENCES.ixABBREVIATED TITLE.Proc. Roy. Soc. . . .Proc. Roy. Soc. Edin. .Proc. Soc. Exp. Biol. Meed.Sitzzmysber. HeidelbergerAkad. Wiss. . . .S’itzungsber. K. skacl. Wiss.Berlin . . . .Soil sci. . . . .Stm. q e r . ngr. itnl. , .S‘vcnsk. Kern. Tidskr. .T . . . . . .Trans. Yaraday Soc. . .Trans. Roy. Soe. Canada .Zeitsch. anal. Chem. . .Zeitsch. angew. Chem. .Zeitsch. nnorg. Chem. . .Zeitsch. Elektrochem. . .Zeitsch. ges. Schiess. 16.Zeitsch. Krybt. &fin. . .Zeitsch. Nahr.-Gcnzcssm. .Sprengstoj’w , . .Zeitsch. physikal. Chem. .Zeitsch. physikal. Chein.Unterr. . . .Zeitsch. yhysiol. Chem. .JOURNAL.Proceedings of the Royal Society.Proceedings of the Royal Society of Edinburgh.Proceedings nf the Society for Experimental BiologySitzungsberichte der Heidelberger Akademie derSitzungsbericli te der Koniglich Preussischen AkadSoil Science.Stazioni sperimentali agrarie italiene.Svmska Kemisk Titlskrift.Transactions of the Chemical Society.Transactions of the Faraday Society.Transactions of the Eoyal Society of Canada.Zeitschrift fur analytische Chemie.Zeitschrift fiir angewandte Chemie.Zeitschrift fur nnorganische und allgemeine Chemie.Zeitschrift fur Elektrochemie.Zeitschrift fiir das gesammte Schiess-und SprengstoffZeitschrift furKrystalIogmphie und Mineralogie.Zeitschrift fiir Untersuchung der Nahrungs- undZeitschrift fur physikalische Chemie, StochiometrieZeitschrift tur den physikalischen und ChemischcnHoppe-Sey Ier’s Zeitschrift fur physiologisehe Chemie.and Medicine.W issensciiaf2en.emie der Wissenschaften zu Berlin.wesen.Gensssrriittel.und Verwandtschaftslehre.Un terricht

ISSN:0365-6217    

DOI:10.1039/AR91916FP001

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.ALTHOUGH it is not possible to report any material increase in thenumbers of papers which have been published during the year, yetthere is no doubt that much valuable work has been carried out.In general it may be said that the records have a more than com-mon interest. I n particular two investigations may be mentionedas being of especial importance. First and foremost is the dis-covery by Sir Ernest Rutherford bhat the atom of nitrogen isdisintegrated or decomposed when it is bombarded by the a-particlesfired off from radium-C. There is no doubt that the shock of thecollision is sufficient to disrupt the atom and cause it to decomposeinto two atoms of hydrogen and possibly three atoms of helium,but the latter has not yet been proved.The fundamental import-ance of this discovery must be acknowledged by everyone. Thegreat debt that chemistry owes to physicists is still further in-creased, for it cannot be denied that the influence of the sisterscience on the fundamental principles of chemistry has been pro-found. Radioactivity, on the one hand, and the energy quantumtheory on the other, exemplify the truth of this. The energy quantumtheory is not yet fully weaned, but it bids fair to have as profoundan influence on the chemistry of to-day as had John Dalt-on’s theoryof material quanta, the atoms, on the chemistry of his day.A second paper of note, is that by Dr. Maxted, on the poisoningof palladium as a catalyst by hydrogen sulphide. For the firsttime a quantitative basis has been found for the activation of agas by a catalyst.Although this may by some be thought to lieoutside the purview of pure inorganic chemistry, yet this is not afair criticism. The resolution of hydrogen sulphide into hydrogenand sulphur, and the formation of the complex Pd,S is pure inor-ganic chemistry. To mention these facts without reference to theresulting depression of the occlusive power of palladium and thequantitative relation now discovered would be an injustice to thisbranch of chemistry, which promises to become one of the mostfruitful fields of investigation of the problems of chemical reaction.2INORGANIC CHEMISTRY. 27Atomic Weights.The International Committee on Atomic Weights has issud areport on the experimental work that has been carried out onatomic weights since 1916.The report deals in particular with theatomic weights of hydrogen, carbon, bromine, boron, fluorine, lead,gallium, zirconium, tin, tellurium, yttrium, samarium, dyspro-sium, erbium, thorium, uranium, helium, and argon. Attention isdrawn to certain important determinations and it is recommendedthat new values be adopted for the atomic weights of argon, boron,gallium, yttrium, and thorium.Argon.-From the density and compressibility of this gas Leducfound the atomic weight to be 39.91.1 Since there is some uncer-tainty as to the second decimal place the new value 39.9 has beenadopted.Borort.-The atomic weight of boron has been determined by theconversion of anhydrous borax into sodium sulphate, carbonate,nitrate, chloride, and fluoride.2 Eight independent values wereobtained for boron, ranging from 10.896 to 10.905, and i t is recom-mended that the mean value of 10.90 be adopted.Gallium .-Some preliminary determinations of the atomic weightof gallium from the analysis of gallium chloride gave the values of70-09 and 70.11.3 The provisional adoption of 70.10 is recom-mended.Thom'ztm.-It is no'w recommended that the value of 232.15 beadopt'ed for the atomic weight of thorium, based on a series ofanalyses of thorium bromide .4 Two values were obtained, namely,232.152 from the silver ratio, and 232-150 from the Ag:C1 ratiowhen Br = 79.916.Yttrium.-The atomic weight of ythrium has been determinedfrom the analysis of the anhydrous chloride5 Seven specimens ofthis salt were used and the extreme values 89.30 and 89.34 wereobtained.The Committee also recommends that in place of the value of14.01 for nitrogen the more precise value 14.008 be adopted, whichis probably correct to within 1 unit in the third decimal place.Reference may be made to a determination of the atomic weight1 A.Leduc, Compt. rend., 1918, 167, 7 0 ; A., 1918, ii, 266.2 Smith and Van Haagen, Carnegie Inst. Washington, Pub.?. No. 267, 1918.3 T. W. Richards, W. M. Craig, and J. Sameshima, J . Amer. Chem. SOC.,4 0. Hsnigschmid and (Mlle.) S. Horovitz, Monatsh., 1916, 37, 105; A,,5 H. C. Kremers and B. S. Hopkins, J . Amer. Chem. SOC., 1919, 41, 718;It is recommended that the value 89.33 be adopted.1919, 41, 133 ; A., ii, 158.1916, ii, 484.A., ii, 46628 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of scandium by analyFis of the bromide.6 Two specimens of scan-dium were employed, both of which were found to be spectro-scopically pure. From ope the value Sc=45.105 was obtained asthe mean of eight experiments, whilst the other gave as the meanof ten experiments Sc=45.093.The mean of the whole is45.099 k0.014, which differs considerably from the present inhrna-tional value 44.1. Since the last reference to the subject in theAnnual Report for 1916 a considerable amount of work has beencarried out on the atomic weights of the isotopes of lead, andseveral papers have appeared during this year.', g~ 99 10$11 It is hardlypossible as yet to draw any definite conclusions from this work asto the atomic weights of these isotopes since the values obtained bydifferent experimenters are not concordant.The problem wouldappear to be complex owing to the possibility that the isotopesthemselves are not stable.Several papers also have been published on the present-day con-ception of chemical elements, both from the point of view ofatomic structure and from the point of view of atomic stability.Amongst the former the most outstanding contribution is a newtheory of the atom developed by Langmuir.12 Although this doesnot fall within the purview of this Report, yet i t cannot be passedby without notice because the netw conception would seem to accountfor the phenomena of valency and chemical combination in a betterway than does the Bohr-Rutherford atom.Then again brief reference must be made to very striking workof Rutherford on the collision of a-particles with light atoms.13The most astonishing result was obtained with nitrogen when sub-mitted to the action of a-particles from radium-C.The resultsobtained leave little doubt that when a nitrogen molecule collideswith an a-particle the result is not nitrogen atoms but atoms ofhydrogen or atoms of mass 2. It is interesting to note that whilstthe majority of the light atoms have atomic weights representedby 4n or 4rt+3, where n is a whole number, nitrogen is the onlyone with an atomic weight of 4rt+ 2. Radioactive data would lead0. Hbnigschmid, Zeitsch. Elektrochem., 1919, 25, 91 ; A., ii, 285.T.W. Richards and N. F. Hall, J . Amer. Cham. Soc., 1917, 39, 537 ; A.,19i7, ii, 230.* A. L. Davis, J . Physical Chem., 1918, 22, 631; A . , ii, 107.lo 0. H6nigschinid, Zeitsch. Elektrochem., 1917, 23, 161 ; A., ii, 465.l1 K. Fajans, F. Richter, and (Frl.) J. Rauchenberger, Xitzurtgsber. Hcidel-l2 I. Langmuir, J . Amer. Chem. SOC., 1919, 41, 868 ; A., ii, 328.l3 Sir E. Rutherford, Phil. Mag., 1919, [vi], 37, 537, 562, 571, 581 ; A.,8. Meyer, Monatsh., 1919, 40, 1 ; A., ii, 385.berger Akad. Wiss., 1918, 28 ; A., ii, 7.ii, 256, 258, 259, 26029 INORUANIC CHEMISTRY.to the view that the nitrogen atomic nucleus consists of three heliumnuclei and either two hydrogen nuclei or one of mass 2. It is diffi-cult t o avoid the conclusion that the nitrogen atom when in colli-sion with an a-particle is disrupted into helium and hydrogen, andRutherford suggests the probability that the use of a-particles orsimilar projectiles, of still greater velocity, will result in the disinte-gration of many of the elementary atoms of small atomic weight.Although radioactive data, as Rutherford says, may have led tothe conclusion that the nucleus of the nitrogen atom is compoundedfrom three helium nuclei and two hydrogen nuclei, yet to thestudent of inorganic chemistry this observation of ita disintegrationmust form one of the most remarkable of those made in recentyears.I n his lecture before the Chemical Society Soddyl* has laidgreat stress on the far-reaching conclusions as t o atomic structurethat have been drawn from the study of radioactivity.Howeverdefinibe may be the arguments leading to a specific conclusion, i tmust be confessed that the conservatism of a chemist will onlygive way before real experimental proof. It is quite true that thewhole question of atomic structure and atomic stability was raisedby the discovery of radioactive disintegration, but to many chemiststhis phenomenon was only a troublesome property of one or twoless common elements of large atomic weight. They found securityin the statement that the radioactive disintegration of an elementis quite independent of external influence, and thus believed thelighter atoms to be perfectly stable entities. I n reality it is thisindependence that has been found to be incorrect, for it has beenfound possible to induce atomic disintegration by the use of par-ticles moving with great velocity, and the disintegration of nitrogenis the first to be observed.Molecular 'CV eigii ts.An important paper has been published on the molecular weightof molten stilphur.15 The method employed was that of surface-tension measurements made from observations of the rise in capil-lary tubes. Considerable difficulty was found a t first in obtainingpure specimens of sulphur.This was overcome by distilling thesulphur and immediately pouring the distillate into the experi-mental apparatus. The apparatus was then filled with dry nitro-gen and the sulphur boiled for 15 to 20 minutes. After coolingthe apparatus was exhausted and allowed to remain overnight.Itwas then again filled with nitrogen and the sulphur once moreboiled. This procedure was generally found sufficient to free the14 F. Soddy, T., 1919, 115, 1.A. M. Kellas, ibid., 1918, 113, 90330 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sulphur from all impurities. It was found that a remarkablechange in the molecular complexity occurs a t about 160O. By theRamsay and Shields method of calculation the molecule of sulphurbetween 1 1 7 O and 157O is found to be S,, whilst between 160° and4 4 5 O it is S18. It wauld seem, therefore, that the suIphur moleculeundergoes an endothermic termolecular polymerisation a t about160°, 3S,=-(S6),. The author draws attention to the various criti-cisms that have been made of the Ramsay and Shields method andpoints out that all the recent methods of calculation indicate con-siderable association. Whilst the complex s, for mobile sulphuris corroborated by several methods, yet the Ramsay and Shieldsvalues seem to agree better with the experimental results.I n connexion with this work there may be mentioned an inveati-gation into the light-absorbing power of sulphur vapour betweenthe temperature limits of 400° and 1,200O.16 The remarkable fact,is recorded that the absorption of light increases to a maximum at650° and then decreases with increase of temperature.Moreover,there appears to be a definite absorption band developed, which hasa maximum intensity a t 650° and decreases rapidly in intensityas the temperature is decreased or increased.It is thus evidentthat the molecular intensity a t 650° must differ markedly from thata t 400° and 1,200°. According to Biltz the, sulphur vapour at thelower temperature consists of S, and a t the higher temperature ofS, molecules. No determinations of the vapour density of sulphurwere made by Biltz between 606O and 1,400°, but by extrapolationof his curve the density value for the temperature 650° correspondswith the formula S,. It is very noteworthy that this temperatureis the very one a t which the optical properties of the vapour aredistinct from those of the vapour composed of S, o r S, molecules.It is to be remembered that ozone has a greater absorptive powerthan oxygen.For these reasons the conclusion is drawn that at650° S, molecules form thel principal component of the equilibriumin sulphur vapour.Group 1.Investigation has been made of the normal and acid sulphates ofsodium in equilibrium with neutral and acid solutions over thetemperature range from -30° to lZOO.17 The existence of the fol-lowing salts was confirmed : Na,SO, ; Na,S0,,7H20 ; Na,SO,,lOH,O ;N%SO,,NaHSO, ; NaHSO, ; NaHSO,,R,O ; NaHSO,,H,SO, ;NaHS0,,H,S04,1*5H,0 ; Na,S04,2NaH:S04.16 Sir J. J. Dobbie and J. J. Fox, Proc. Roy. SOC., 1919, [A], 95, 481 : A . ,ii, 334.P. Pascal and Ero, Bull. SOC. chim., 1919, [iv], 25, 35; A., ii, 154INORGANIC CHEMISTRY. 31A similar investigation18 has been carried out, but under morelimited conditions as the observations were made a t only two tem-peratures, 1 4 O and 2 5 O .I n addition to N%SO,,lOH,O the follow-ing were obtained: Na&O,, NaHSO,, and NaHSO,,H,O. I n thispaper the investigation is described of the systems CuS04-H2S04-H,O, Na,SO,-CuS0,-H,O, and Na2,S0,-CuS0,-H2S04-H,0.I n the first no acid sulphates of copper were obtained, the effect ofthe sulphuric acid merely being to dehydrate the pentahydrate instages to the trihydrate, monohydrate, and the anhydrous salt.I n the second series the double salt Na,S0,,CuS04,2H,0 was ob-tained above 16*7*, whilst in the third series no salt other than thosementioned was obtained.Methods have been described for the preparation of the yellowamorphous modification of cuprous oxide.19.It is most readilyobtained by the reduction of a cupric salt by means of hydroxyla-mine in the presence of alkali. It can also be prepared electrolyti-cally, using an alkali sulphate as the electrolyte and an anode ofpure copper. The amorphous oxide when first precipitated is paleyellow and is probably a hydroxide. I n the absence of air thed o u r quickly changes to orange or brick-red, probably through lossof water. After drying, the oxide contains 2-3 per cent. of ab-sorbed water. On heating at a high temperature, above a low redheat, the water is lost and the amorphous oxide changes into thestable red crystalline modification.By the addition of a slight excess of sodium hydroxide to anaqueous solution of copper and aluminium sulphates containingapproximately 5 per cent.of CuO and 95 per cent. of A120,, a verypale blue precipitate is obtained.20 This precipitate retains itscolour after being thoroughly washed and dried a t looo. Whenground to a very fine powder and heated, first in a Bunsen flameand then in a blowpipe flame, it changes in colour to a pale greyish-blue with no signs of blackening. If the precipitate containsabout twice it9 much cuprio oxide it remains blue after heating inthe Bunsen flame, but shows signs of blackening when heated inthe blowpipe flame. It is suggested that the alumina stabilisesthe blue cupric oxide and that the change from blue to black isdue to an agglomeration of the particles. Anaiogous results wereobtained in some preliminary experiments with manganous, cobal-tous, and nickelous oxidea.l8 H.W. Foote, J . Id. Eng. Chem., 1919, 11, 629; A., ii, 361.L. Moser, Zeitsch. anorg. Chern., 1919, 105, 112; A., ii, 155.so H. E . Schenck, J. Physical Chem., 1919, 23, 283 ; A., ii, 28682 ANNUAL REPORTS O N THE PROGRESS OF CHEMISTRY.Group 11.A convenient method has been described for the extraction ofglucinum from beryl.21 The powdered mineral is treated with twoparts of sodium silicofluoride a t 850° for 30 to 40 minutes. Thesilicon fluoride which is evolved at this temperatare attacks theberyl and forms glucinum fluoride and aluminium fluoride, whichin turn combine with the sodium fluoride to give the correspondingdouble fluorides. On extracting the material with boiling water,the sodium glucinum fluoride dissolves, and the filtrate contains prac-tically the whole of the glucinum together with a little alumina andsilica.A slight excess of boiling sodium hydroxide solution isadded, and the precipitated oxides are collected and redissolved insulphuric acid. The1 solution is concentrated and the glucinum sul-phate is allowed to crystallise. By this method 90 per cent, of theglucinum present in the mineral may be readily recovered. Basedon this process a method is described for the estimation of glucinumin beryl.It has been found that alloys of magnesium and lead containingfrom 5 to 50 per cent. of magnesium are very reactive, and whenexposed t o moist air readily absorb the, whole .of the oxygenpresent.22 The two metals form the compound Mg,Pb and thisalloy, containing 90 per cent.of magnesium, is the most reactive ofthe series. During the oxidation process the alloy crumbles to ablack powder which consists of magnesium hydroxide, Mg(OH),, andhydrated lead sub-oxide, Pb,(OH),. I n dry air the mixture maybe kept unchanged, but in the presence of water the lead sub-oxideis oxidised to Pb(OH),. With the mor0 reactive alloys, the actiontakes place in the cold, but when more than 35 per cent. of mag-nesium is present heat is necessary. Alloys of magnesium andzinc are far less reactive, and indeed show greater resistance tooxidation than either magnesium or zinc.A scientific investigation of commercial superphosphates has beendescribed and although the principal subject involved is the ques-tion of the preparation and analysis, the results are of importancein connexion with monocalcium phosphate and dicalcium phos-phate.23 When increasing quantities of monocalcium phosphate aredissolved in a given weight of water at constant temperature, theproportion of free phosphoric acid continually increases and tendstowards a limit in accordance, with the equation2CaH4(P0& CaH,(PO& + CaHPO, + H,P04.21 H.Copsux, Compt. rend., 1919, 168, 610: d., ii, 192.22 E. A. Ashcroft, Trans. Faraday SOC., 1919, 14, 271 ; A., ii, 465.23 A. Aits, Anna& Chirn. Appl., 1918, 10, 45 ; A., ii, 25INORGANIC CHEMISTRY. 33u p to the saturation point at 1 5 O there thus exists a liquid phaseconsisting of water, monocalcium phosphate, and free phosphoricacid, and a solid phase of dicalcium phosphate formed by hydro-lysis of the monocalcium phosphate. It is commonly believed thatthe reaction between sulphuric acid and mineral phosphates takesplace in two stages :-3Ca3(P04), + 6H2S04 = 4H3P04 + Ca3(P04), + 6CaS04Ca,(PO,), + 4H3P04 = 3CaH4(P04),,but it would seem that the principal reaction is more correctlyrepresented by the equation:5Ca3(P04), + llH2S04 = 4CaH4(P04), + 2H3PO4 + 11CaSO4.The influence of raising the temperature on the reaction is t o in-crease the concentration of phosphoric acid in the liquid phase,whilst in the solid phase dicalcium phosphate increases in equalproportion with the free phosphoric acid.These constituentsgradually react to form monocalcium phosphates.An investigation has been made of the decomposition of bariumperoxide by heat a t atmospheric pressure, the method being thatof the observation of tahe heating curve.24 The peroxide was heatedin a carbon tube furnace and the temperature was recorded every10 seconds.Since the decomposition is an endothermic reactionits temperature range is indicated by a pronounced flattening ofthe curve towards the time axis. The temperature at which thedissociation pressure is equal to 760 mm. was found to be 795O,which is in good agreement with Le Chatelier's value1 796*.I n the presence of cupric oxide barium peroxide starts to decom-pose at 200°, the reaction becoming most vigorous at 625O to 660O.On the other hand, when the peroxide is heated with amorphoussilica the rate of rise of temperature is increased above 400O.I nall probability this is due to an exothermic reaction between thebarium oxide and silica to give barium silicate. The heating curveshows a similar indication of the formation of silicate even whenthe peroxide has been mixed with powdered quartz glass or quartz.In connexion with this it may be noted that strontium peroxidemay be prepared from strontium oxide by heating it in oxygenunder a pressure of 105 to 126 kilos. per sq. cm. a t a temperature of400° to 500O.25 The product contains more than 85 per cent. ofSrO, and resembles barium peroxide in its physical properties.The preparation of various sub-oxides of cadmium has beendescribed from time t o t-ime and the previous investigations have14 J.A. Hedvall, Zeitsch. anorg. Chem., 1918, 104, 163; A., ii, 26.' 6 J. B. Pierce, jun., Brit. Pat. 130840 ; A., ii, 413.BEP.-VOL. XVI. (34 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.now been repeated.26 The first method consisted in heating theoxalate a t 300° in a rapid stream of carbon dioxide. A small quan-tity of green material was obtained which, however, contained freecadmium. Analysis of this heterogeneous material gave valuesclosely approximating to Cdl=96.5 per cent., whilst Cd,O 27 requires96-56 per cent. By heating this substance in a vacuum it wasfound possible to distil off the free cadmium, leaving a homoge-neous green mass which on analysis was found to be Cd,O.The reduction of the brown oxide in hydrogen or carbon mono-oxide always gave an obvious mixture of the oxide and cadmium.The process described by Morse and Jones28 was repeated and smallquantities of Cd,O were obtained.Anhydrous cadmium chlorideis fused with cadmium and the product treated with wat.er. Cad-mous hydroxide is obtained from which yellow cadmium sub-oxidemay readily be prepared by dehydration. By each of these pro-m s ~ Cd20 may be prepared, but only in very small quantities.Anhydrous mercuric fluoride has been obtained by heating mer-curous fluoride in a current of dry chlorine a t 275O, or of drybromine a t 400° 29 It may also be prepared by heating mercurousfluoride at 450° under 10 mm. pressure. It forms transparent,octahedral crystals, m.F.645" and b.p. estimated a t 650O. Thevapour of mercuric fluoride is very reactive, and therefore it wasnot found possible t o measure its vapour pressure a t various tem-peratures since the containing veissels are attacked. The sub-stance reacts very readily with. moisture and becomes discoloured inthe preaence of minute t>aces of water vapur. On exposure tomoist air, hydrogen fluoride is evolved and mercuric oxyfluorideand, ultimately, mercuric oxide are formed. With small quanti-ties of water, a white, hydrated oxyfluoride, Hg3F,(OH),,3H20, isproduced. By cautious evaporation of a solution of mercuricfluoride in a 40 per cent. solution of hydrogen fluoride small colour-less crystals are deposited of the hydrated fluoride, HgF2,2H,0.Mixtures of the anhydrous fluoride with silver, copper, lead,aluminium, magnesium, zinc, tin, chromium, iron, or arsenic reactvigorously when strongly heated, yielding amalgams and metallicfluorides.The latter may readily be isolated in the pure conditionif an excess of mercuric fluoride be used. Silicon fluoride appearsto be formed when mercuric fluoride is heated with silicon, but noreaction occurs with either amorphous or graphitic carbon.26 H. G. Denham, T., 1919, 115, 556.87 8. Tanatar, Zeitsch. anorg. Chem., 1901, 27, 432 ; A,, 1901, ii, 553.28 H. N. Morse and H. C. Jones, Amer. Chem. J., 1890, 12, 488 ; A., 1890,s9 0. Ruff and G. Bahlau, Ber., 1918, 51, 1762 ; A., ii, 66.1376INORGANIC CHEMISTRY.36By heating mercurous fluoride in a current of dry chlorine at120° mercuric chlorofluoride is formed, and similarly the bromo-fluoride is obtained a t 105O. Both these substances are pale yellow.By the action of various thioamides on mercuric nitrite a complexsulphoxynitrite of mercury has been prepared.30 This compound isheavy, granular, and yellow, and can be dried in a steam-oven.By analysis the empirical formula was found to be 3(SHgNO,),HgO,but it is sugyested that the molecular formula is [3(SHgN02),HgO],,since the unimolecular formula represents an unsaturated com-pound. This substance is insoluble in water or acetone, but dis-solves in hydrochloric acid with copious evolution of nitrous fumes.When boiled with water it decomposes and is converted into blackmercuric sulphide.I n a similar manner the compound(SHgNO,),O has been obtaiiied. By tlhe action of ethyl iodide onthe sulphoxynitrite dimercuric di-iodo'disulphide, I*Hg*S-S=Hg*l,is produced. This compound is a pale yellow granular powderwhich darkens in the light, but. regains its colour when kept in thedark.The chlorine analogue1 of the sulphoxynitrite, [3 (SHgC1) ,HgO],,has also been prepared by the action of certain thioamides on mer-curic chloride.31 It forms a white amorphous precipitate which onremaining for 24 hours becomes granular.GTO'ZL~ 111.Some very interesting work has been carried out on the separationand purification of galliurn.32 I n the first place, a method has beendescribed for the recovery of gallium and also of germanium fromzinc ores.Since bot'h these metals are less volatile than zinc theyremain behind in the retorts when the zinc distils off. These resi-dues furnish a good source of gallium and germaniuq, althoughthe amounts obtainable vary very considerably. The method oftreatment, may be very briefly described. One kilo. of the oxideprepared from the zinc residues was added in small portions a t atime to 2400 C.C. of hydrochloric acid. When all had dissolved alittle potassium chlorate was added carefully until, after vigorousshaking, oxides of chlorine were evolved. The solution was thendistilled with a thermometer placed with its bulb in the liquid.Two fractions were collected, the first, up to 121°, containing verylittle germanium, and the second, up to 135-140°, containing practi-cally the whole of the germanium.The second fractions fromSQ P. C. Rky, T., 1917, 141, 101.81 Sir P. C. R&y and P. K. Sen, ibid., 1919, 115, 552.88 H. C. Fogg and C. James, J . Amer. Chern. SOC., 1919,41, 947 ; A., ii, 344.c 36 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.several quant,ities were saturated with hydrogen sulphide and thewhite germanium sulphide filtered off. The liquid left in the flaskwas diluted in water and the lead chloride allowed to settle. Theclear Equid was decanted and treated with ammonium hydroxideuntil a slight permanent precipitate was obtained, metallic zincwas added, and the whole digested at the boiling point for severalhours, after which the precipitated metals and basic salts were col-lected.Ten such precipitates were united and dissolved in hydro-chloric acid with the aid of a little potassium chlorate and the leadchloride allowed t o settle. The clear liquid was again saturatedwith hydrogen sulphide and filtered. The filtrate was boiled,neutralised with ammonium hydroxide until a permanent precipi-tate was formed, and again digested with zinc a t the boiling point.The precipitates rich in gallium were again dissolved in hydro-chloric acid, the solution nearly neutralised, saturated with hydro-gen sulphide and filtlered. The filtrate was treated with ammoniumchloride, made alkaline with ammonium hydroxide, and boiled untiljust acid. A gelatinous precipitate consisting of gallium, alumi-nium, and iron hydroxidM was filtered off and washed. The gal-lium was finally separated from the aluminium by the electrolysisof a strongly alkaline solution of the hydroxides.Independent work on tlhe preparation of pure gallium and itssalts has also been carried 3 4 35 In such work the methods oftesting the purity are of importance, especially in view of the diffi-culty of separating gallium from indium.A very delicate test hasbeen found in the spark spectrum, for by this means it is possible t odetect as little as 0.06 per cent. of indium in gallium and of 0.18per cent. of gallium in indium.It is possible to separate gallium and indium by the electrc!ysisof a dilute solution of their sulphatee, perfectly pure gallium beingobtained after 14 electrolysett.Pure gallium chloride can also beobtained from mixtures of gallium, indium, and zinc by the frac-tional distillations of the chloride in a current of chlorine. Amethod is described for the separation of gallium and indium byprecipitation of their hydroxides, Solutions containing both ele-ments are largely diluted and treated with a little hydrochloricacid, and then exactly neutralised with sodium hydroxide, anexcess of 1.5 grams of sodium hydroxide is added and the solutionboiled for several minutes. The precipitated indium hydroxide iswell washed, dissolved in hydrochloric acid, and the process r?33 L. M. Dennis and J. A. Bridgman, J. Arne?'. Chem. SOC., 1918, a, 1531 ;84 T. W. Richards, W.M. Craig, and J. Sameshima, ibid., 1919, 41, 131 ;A,, 1918, ii, 456.A., ii, 157. 56 T. W. Richards and S. Boyer, ibid., 133 ; A., ii, 158INORGANIC CHEMISTRY. 37peated. Finally, it is dissolved again in hydrochloric acid, precipi-tated by ammonia, washed, dried, and ignited to onide. To thecombined filtrates and washings from all these operations sodiumsulphite is added, and the solution boiled vigorously for fourminutes, when gallium hydroxide is precipitated.It would seem, however, that the hydroxide separation methodis not very satisfactory, since the gallium thus obtained still con-tains some indium. I f , however, the gallium hydroxide is dis-solved in an acid and the slightly acid solution electrolysed thegallium is obtained pure. The melting point of the gallium pre-pared in this way is 30.8O as compared with 26*9O for the metalpurified by the hydroxide process.The compressibility of gallium has been det'ermined and for thesolid element is 2.09 x 10-6, a value which places gallium preciselyon the curve showing the periodic relation of this property to atomicweight.The compressibility of liquid gallium is 3.97 x 10-6, avalue almost identical witlh that of mercury, and nearly twice, asgreat as that of solid gallium, although its volume is less. Thedensities of solid and liquid gallium are 5.885 and 6.081 respec-tively, and thus the view that the marked expansion of galliumon solidificatlion is due to impurities is definitely negatived.I n order to obtain pure gallium chloride it is advisable to burngallium in pure dry chlorine and to distil the impure chloride inpure chlorine, in nitrogen, and in a vacuum successively.Thistreatment was found necessary to eliminate the dissolved chlorine.A preliminary determination of the atomic weight of gallium hasbeen made by the analysis of pure specimens of the chloride.Reference to this has already been made under Atomic Weights.Gallium selenate has been prepared by placing gallium hydroxidein less than the equivalent quantity of selenic acid and heating themixture nearly to the boiling point'. After several hours the solu-tion was filtered from the excess of gallium hydroxide and allowedto evaporate a t o'rdinary temperature. The crystals were collectedand dried to constant weight in the air, and on analysis were found tohave the formula Ga,(SeO,),,l6H,O.It would appear, however,that the crystals which separate from the solution have 22 mole-cules of water of crystallisation. Gallium sulphats also first cry-stallises from its solution with 22 molecules of water of crystallisa-tion.Czsium gallium selenate alum has been prepared by the evapora-tion at ordinary temperature of a solution containing msiumselenate, gallium selenate, and some free selenic acid. This salt is atypical alum, forming regular octahedra with the formula :Cs$eO,, Ga, (SeO,) 3, 24 H,O 38 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The solubilities of ammonium gallium sulphate alum and claesiumgallium sulphate alum have been determined, in water and in 50per cent.and 70 per cent. alcohol, with the, view of testing thepossibility of using the former salt as a means of separation ofgallium. One part of the ammonium alum dissolves in 3-24 partsof water, 4600 parts of 50 per cent. alcohol, and 11,400 parts of70 per cent. alcohol. One part of the msium alum dissolves in66.2 pa-& of water, 25,800 parts of 50 per cent. alcohol, and28,000 parts of 70 per cent. alcohol.Group I V .The view has been put forward that all varieties of graphite andamorphous carbon are different physical forms of “ black carbon,’’which is to be regarded as an allotropic modification ofdiamond .367 37 The physical and chemical properties of graphitevary within such wide limits that no distinct line of demarcationcan be drawn between graphite and amorphous carbon or soot.Theproperties of different samples of graphite depend upon the condi-tions under which it has been produced, and its variable characteris to be attributed to different degrees of dispersity. The reactionsby which graphite is formed are all of the localised type which havebeen grouped together under the name of (‘ t’opochemical ” reac-ti0ns.~8 This view is borne out by the X-ray spectra of graphiteand amorphous carbon, which lead t o the conclusion that the twovarieties are identical in structure, and that amorphous carbondiffers from graphite only by its greater degree of sub-divi~ion.~~In graphite the carbon atoms are arranged hexagonally in planelayers which are superimposed on one anotqher, and as a resultgraphite, oyes its peculiar properties to its lamellar structure.In order further to elucidate the structure of graphite the, oxid*tion of graphite t o graphitic acid and the properties of the latterhave been studied.In order to guard against any possible varia-tions due t o differences in the properties of-the samples of graphite,the experiments were confined to a specially pure electrically pre-pared graphite free from ash. The oxidations were carried outwith a mixture of potassium chlorate, nitric acid, and sulphuricacid in the cold under fixed conditions. This mixture is peculiarly36 V. Kohlschutter, Zeitsch. anorg. Chem., 1919, 106, 36 ; A., ii, 151. *’ V. Kohlschutter and P. Haenni, ibid., 121 ; A., ii, 152.sB V.Kohlschutter, ibid., 1 ; A., ii, 156.89 P. Debye and P. Scherrer, Physikal. Zeitsch., 1917, 18, 291 ; A., 1917,ii, 427INORGANIC CREMISTRY. 39advantageous because it penetratea the whole mass of the graphite.Other oxidising agents which do not penetrate the graphite havelittle action or oxidise it completely t o carbon dioxide. Repeatedtreat'ment of the graphitic acid with the oxidising mixture changesits collour from green to brown or yellow, whilst the carbon contentgradually diminishes. After five oxidations the graphitic acid hasthe composition C=54*4, H=2*14, 0=43.46 per cent. Afterrepeated washings with water, t,he graphitic acid passes into solu-tion. The colloid can be precipitated by dilute acids and the gelis perfectly soluble, in water.The differently coloured graphiticacids merely differ in their degree of dispersity, the paler colouredproducts obtained by repeated oxidation being more highly dis-perse. When heated or treated with reducing agents graphiticacid is reduced to carbon. The temperature a t which the decom-position is explosive is lower the slower the heating, but if the heat-ing is very slow the decomposition may proceed quietly to completion without explosion. The black voluminous residue consists ofcarbon and has all the properties of soot, but it can be compressedinto a mass very similar to graphite. When the decomposition byheat takes place under pressure, the graphitic character of the resi-dual carbon is more marked. Treatment of graphitic acid withreducing agents, such as ferrous or stannous salts, furnishes pro-ducts with strongly marked graphitic properties giving graphiticacid again when oxidised.These results are considered t o supportthe theory that graphite and amorphous carbon are not differentallotropes, but varieties of one allotrope, black carbon.When carbonyl sulphide 40 is passed through an electrically heatedtube, packed with quartz splinters, it decomposes to give carbonmonoxide and sulphur on the one hand, and carbon dioxide andcarbon disulphide on the other. Since it has been proved that thetwo reactions are independent of one another i t is probable that thetwo reactions may be written 2COS 2C0+S2 and2COS zz CO,+ CS,. Some further experiments have shown thatthe action of heat on mixtures of carbon monotxide and carbondisulphide on the one hand and carbon monoxide and sulphur onthe other, gives the same products as when carbonyl sulphide isheated.The reactions therefore are reversible and true cases ofequilibrium exist. Similarly the combustion of carbon disulphidewith an insufficient amount of oxygen or of oxygen in carbon disul-phide vapour yields a mixture of unchanged carbon disulphide,carbon dioxide, sulphur dioxide, carbonyl sulphide, and carbonmonoxide.4 0 A. Stock and P. Seelig, Ber., 1919, 52, [B], 681 ; A., ii, 23040 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Carbonyl chloride may be prepared by the action of carbon tetra-chloride on fuming or ordinary sulphuric acid.41~ 42 With pyrosul-phuric acid the reaction is SO, + H2S04 + CCl, = COCl, + 2S0,HCI.With ordinary sulphuric acid in tlhe presence of infusorial earth asa catalyst the reaction is ZH2S04 + 3CCI4 = 3coc1, + HCI + S,O,CIand a t 150° without catalyst CCl, + H,SO, = S0,HCl + HC1+ COCI,.If slight.ly aqueous acid is used the chlorosulphonic acid gives sul-phuric acid and hydrochloric acid.The carbonyl chloride is puri-fied by solution in carbon tetrachloride and subsequent distillation.The sub-acetate and the sub-sulphate of lead43 have been pre-pared by methods analogous to t'hose used for the sub-haloid salts ofthis meta1.44 The sub-acetate was obtained by the action of thevapour of acetic anhydride on the sub-oxide a t 195O, whilst thesub-sulphate was formed by the action of methyl sulphate vapouron the sub-oxide at 2 8 0 O .The latter salt decomposes on solutionin water, but is stable to the action of heat, for no sign of anychange could be observed on heating it a t 440O.A double nitrate and hypophosphite of lead has been described.45It is obtaineld by adding, with stirring, pure crystalline lead hypo-phosphite (250 grams) to a boiling solution of lead nitrate (500grams) in water (1.5 litres). The mixture is then rapidly cooledwhen the double salt separates out. It has the formulaPb(NO,),,Pb(H,PO,), and is explmive. Its use in percussionfuses is recommended.Some further work 011 zirconium compounds may be reported.46The basic compounds formed by the hydrolysis of zirconium sul-phate in aqueous solution are much more complex than has beensupposed and three basic sulphates have been isolated in the crys-talline form.I n spite of the Crystalline character of these com-pounds their solutions are essentially colloidal. The following basicsulphates have been prepared : Zr,( SO,),(OH),,,lOH,O,Zr8(S0,),(OH),,,8H,0, and [Zr,(S0,),(OH)8]H,,4H,0. The lastnamed had previously been described and given the formula2Zr0,,3S0,,5H20, but the new formula takes into account its acidproperties and explains its ready conversion into either of the firsttwo compounds. The usually accepted formula for potassiumzirconyl sulphate, Zr,O,(SO,),K,, is now shown to be incorrect and41 V. CYTrignard and E. Urbain, Compt.rend., 1919,169, 17 ; A., ii, 340.42 C. Mauguin and L. J. Simon, ibid., 34 ; A., ii, 341.44 Ibid., 1917, Ill, 29 ; 1918,113, 249.45 E. von Hem, Zeitsch. ges. Schiess. u. Sprengstoflw., 1916, 11, 365, 388 ;46 0. Hauser and H. Herzfeld, Zeitsch. anorg. Chem., 1919, 106, 1 ; A.,H. G. Denham, T., 1919,115, 109.p.. ii, 284.ii, 290INORGANIC CHEMISTRY. 41a definite salt, Zr4(S04)5(OH)8K,, has been prepared. Theammonium salt of the above zirconylsulphuric acid,(NH4),Zr4(OH),( S0,),,4H20, has been obtained, together with aless basic salt, (NH4)4Zr(S04)4,5H,0. A basic salt,K,[Zr,( OH),( S04),]8Hz0, has also been prepared.Group V .Reference wits made in the Annual Reports for 1912 and 1915to Franklin's work on the ammonia system of acids, bases, andsalts.' A further contribution has been made during this year andcertain new compounds have been described .47 Dipotassiumammonosodiate, [Na(NH,)3]K,, is obtained by the act,ion of potass-amide on sodamide in liquid ammonia, by the action 'of sodiumiodide on an excess of potassamide in liquid ammonia, or by theaction of sodium on potassamide in liquid ammonia in the presenceof a small quantity of platinum black. This compound crystal-lises well, and does not lose ammonia a t looo in a vacuum. Mono-rubidium ammonosodiate, [Na(NH,),]Rb, is formed by the actionof sodium and rubidium simultaneously on liquid ammonia. Thiscompound is readily soluble in liquid ammonia, and is violentlydecomposed by water with the formation of the hydroxides of themetals.Dirubidium ammonosodiate, [Na(NH,),]Rb,, is formedfrom the mother liquors of the previous compound by the additionof a large excess of rubidamide. Dipotassium ammonolithiate,[Li(NH,),]K,, is prepared by the action of potassamide on lithiumiodide in liquid ammonia solution, and also by the action of lithiumand potassium simultaneously on liquid ammonia in the presence ofplatinum black. Monorubidium ammonolithiate, [Li(NH,),]Rb,is prepared by the action of an excess of a solution of rubidamidein liquid ammonia on metallic lithium in the presence of platinumblack.An important investigation has been carried out on the densitiesof liquid nitrogen peroxide and mixtures of nitrogen peroxide andnitric acid.48 The specific volume of nitrogen peroxide between4 O and ' 180 is expreesed by ZJ = 0.67027 + 0.0010075t + 0*000003t2.The boiling point of the liquid is 21.9+0.1°.Nitrogen peroxide issoluble in nitric acid up to about 54 per cent. and nitric acid ismuch less soluble in nitrogen peroxide, about 7 per cent. Withinthese limits the densities of mixtures of the two substances havebeen determined at 4O, 1l0, and 1 8 O . A maximum density is ob-tained with the mixture cont,aining about 44 per cent. of nitrogen47 E. C. Franklin, J . Physical Chem., 1919, 23, 36; A., ii, 191.W. R. Bornfield, T., 1919, 115, 45.042 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.peroxide. On the other hand, the maximum contraction on mixingis found with mixtures containing 49.3 per cent.of nitrogenperoxide. There is considerable heat evolved on mixing which indi-cates a powerful combination between the two substances. Thecompound 3HN03,2N,0, corresponds with 49.33 per cent. ofN,O,. The maximum value of the density does not indicate theexact composition of the compound since it is so largely deter-mined by the mere density differences of the two components.When the temperature coefficients of expansion are examined theseare found to show a definite minimum for the mixture containing26.7 per cent. of N,O,, which corresponds with the definite compo-sition 4RNo3,N@,. It may therefore be concluded that two specificcompounds exist, namely, 3HN03,2N,04, and 4HN03,N,04.The maximum density of the solution containing about 43 percent.of N,O, has been independently observed,49 and the authorsconsider that this gives evidence of the existence of the compound2HN0,,N,04 or N,05,N204,H,0. They state that the existence ofthis compound is confirmed by a thermal study of the reciprocalsolubilities of nitric acid and nitrogen peroxide. The compound isstable below - 48*5O, and a t tlhis temperature it dissociates, liberat-ing nitrogen peroxide. The density of nitrogen peroxide is ex-pressed by D: = 1.490 - 0.00215t.It has generally been believed that the combustion of ammoniain a deficiency of oxygen proceeds according to the equation4NH3 + 30,= 2N, + 6H,O. It has, however, been shown that underthese conditions the resulting gas consists of about 59 per cent. ofnitrogen and 41 per cent.of hydrogen,50 the explanation beingoffered that it portion of the ammonia is dissociated into nitrogenand hydrogen a t the high temperature of the flame. If this werethe correct explanation considerable quantities of nitrogen shouldbe formed when ammonia is burnt in excess of oxygen, which is notthe case. A possible explanation may be found in the formation ofthe hypothetical di-imide, when insufficient oxygen is present,which would decompose into nitrogen and hydrogen.51 The reactionmay be expressed therefore by the equation 2NH, + 0, = N,H,+ 2H20. When potassium hydra,zinesulphonate was heated withpotassium hydroxide in the expectation that thel hydroxyhydrazineprimarily formed would immediately give di-imide by loss of water,the calculated amount of potassium sulphite was obtained and amixture of equal volumes of hydrogen and nitrogen.A second4 0 P. Pascal and M . Gamier, Bull. So'c. chim., 1919, [iv], 25, 309 ; A.,ii, 339.Muller, Zeitsch. physikal. Chem. Unterr., 1913, 169.ti1 F. Raschig, ibid., 1918, 31, 138 ; A., ii, 149INORGANIC CHEMISTRY. 43alternative is that the combustion proceeds with the intermediateformation of hydrazine, 4NH, + 0, = 2N,H4 + 2H20. The form*tion of hydrazine when oxygen burns in ammonia has actually beenproved by the formation of benzylideneazins. It is concluded thatthe combustion gives mainly di-imide and also hydrazine to a lessextent, and that the direct formation of the nitrogen according tothe commonly accepted reaction does not take place at all.The, reduction of arsenious acid by means of stannous chloridehas been the subject of systematic study.52 It was recorded byBettendorf 53 that a voluminous, brown precipitate of arsenic isobtained, accompanied by traces of non-removable tin.There seemslittle doubt that as the first product of this reaction arsenic is ob-tained as the yellow allotropic modification. A portion of it issoluble in carbon disulphide and the yield of yellow arsenic is in-creased if the reaction mixture is shaken with carbon disulphideduring the process of reduction. The results indicate that the veryearliest deposit of arsenic is of the yellow type, but that unless cer-tain unascertained conditions obtain, the yellow variety spontane-ously becomes brown or grey.The reaction does not take place if the two chlorides are anhy-drous, but readily proceeds if the mixture of anhydrous chloridesis moistened with water.I n general it is found that the reactionis accelerated chiefly by increase in the concentration of hydro-chloric acid, next by that of arsenic chloride, and least by that ofstannous chloride. The results obtained in velocity measurementslead to the view that the reaction takes place between arseniousand chloride ions and the complex H2SnC1,. Dilution with waterrapidly decreases the. velocity, owing no doubt to the hydrolysis ofthe amenious chloride.A number of double compounds have been described of arseniousoxide and the iodides of bivalent light and heavy metals.64 Themoderately concentrated solution of the iodide is saturated in thehot with arsenious oxide and allowed to cool, when the compoundseparates in crystals, sometimes with a little free arsenious oxide.The following have been prepared : G11,,3As,0,,8H20 ; Mg(or Ca orSr)I,,3A~03,1ZH,0 ; Ba12,3As,03,9H,0 ; Zn12,3A~0,,10H20 ;Mn(or Fe or Co)I,,4As20,,12H20 ; NiI,,4As203,10H20 ;A113,6A~20,,18( 1 )H,O ; LiI,2As20,,3H,O.In properties these com-pounds resemble the arsenites of the metals, the characters of theiodides being suppressed. They are moderately stable in dry air,but tend to become oxidised on keeping. With the exception ofsB R. G. Durrant, T., 1919,115, 134.53 Sitzungsber. Miederrhein. Ges. Bonn, 1869, 128.R. F. Weinlaad and P.Gruhl, AT&. P h m . , 1917,255, 467 ; A., ii, 411.a* 44 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the magnssium compound these salts are sparingly soluble in water,and when heated with water they tend to undergo partial dissocia-tion into the iodide and arsenious oxide. It is believed that thesecompounds approximate in constitution t o a complex salt with sim-ple metallic cation.Investigation has shown that antimony pentoxide does not formthe definite hydrates, ortho-, pyro-, and meta-antimonio acids, ashas hitherto been supposed.65 Analyses of the various hydrates havebeen made, and their dehydration curves obtained by keeping themover sulphuric acid in a desiccator. It is found that the propertiesof the antimonic acids vary with the method of preparation andwith previous treatment.Thus the modifications prepared eitherby the action of water on antimony pentachloride or by the actionof acids on antimonates, or by the hydrolysis of antimony tri-chloride in the presence of nitric acid differ in their water content,stability, solubility, and their action towards acids and alkalis.The differences observed are in all probability due to variations inthe size of the particles. It appears that the soluble antimonicacids are hydrosols with small stability and that the definitehydrates, H,SbO,, H,Sb,07, and HSbO,, can have no free existence.The hydrates exhibit marked selective absorption towards dilutealkalis t o give amorphous substances which apparently are alkaliantimonates.The hydrates dissolve in concentrated alkali solutionsand from these solutions by cautious evaporation a t low tempera-ture various alkali antimonates may be crystallised. The nature ofthese salts depends, however, on the concentration of the motherliquor.When magnesium which has been covered with thorium4 (anisotope of bismuth) is dissolved in hydrochloric acid, a small quan-tity of a radioactive hydride is obtained. This observation leads tothe belief that bismuth forms a volatile hydride, and the existenceof this compound has been definitely proved both by radioactivemethods and also by its preparation from non-radioactive mate-rials.56J57 The second method has a greater importance since allcriticism arising from possible misconception of radioactive pheno-mena is eliminated.A bismuth magnesium alloy is prepared bymelting together equal weights of powdered bismuth and magnesium(as free from silicon as possible) in an iron crucible in a rapid cur-rent of hydrogen. When this alloy is dissolved in approximately4N-hydrochloric or sulphuric acid sufficient bismuth hydride is ob-S5 G. Jander, Kolloid Zeitsch., 1918, 23, 122 ; A., ii, 29.5~ F. Paneth, Zeitsch. Elektrochem., 1918, %, 298 ; A., ii, 30 ; Ber., 1918,I 7 F. Paneth and E. Winternitz, Ber., 1918, 51, 1728 ; A., 3, 68.51, 1704 ; A., ii, 67INORGANIC CHEMISTRY. 45tained to permit its detection either by the bismuth mirror test orby the luminescence test. The bismuth mirror as obtained in theusual Marsh's apparatus very closely resembles the antimony mir-ror, and consists of a strong brown ring in front of the heated spotand a fainter ring behind it.Only about 5 x 10-5 of the bismuthused is converted into the hydride but the optimum conditions havenot yet been determined. The luminescence test gives a very satis-factory method of detection of the bismuth hydride. The gasesissuing from the Marsh's apparatus are ignited, and a piece of purecalcium carbonate is held on a platinum loop in the flame. Thehydride is decomposed and a portion of the bismuth is depositedon the lime. The lime is allowed to cool and is then placed a t theedge of the hydrogen flame, when the presence of bismuth is shownby a cornflower-blue phbsphorescence. A sky-blue phosphorescenceis shown by antimony.Bismuth hydride is absorbed to some extent by water and4N-sulphuric acid.The gas is absorbed more readily byO.5N-sodium carbonate and N-potassium hydroxide, and also bycalcium chloride or soda-lime. It is completely decomposed by con-centrated sulphuric acid.Group V I .The boiling point of sulphur as a standard temperature hasbeen discussed together with the conditions which must be ob-served.58 The vapour pressure over the range 700-800 mm. hasbeen measured and within these limits the relation between tem-perature and pressure is given by:t =444*60 + 0*0910(p - 760) - 0.000049(p - 760)2.By the action of liquid sulphur dioxide on the iodides of sodium,rubidium, and caesium, sulphones of the type MI,,3soz have beenprepared.69 The sodium compound is amorphous, but the other twocan be crystallised from their solution in liquid sulphur dioxide.The dissociation pressures of these compounds have been measuredbetween - 22.5O and 20.9O, and they show increasing stability.withrise in atomia weight of the metal.The molecular weight of sulphur monochloride in solution inbromoform has been found to correspond with the formula SzC1,.The freezing point of bromoform is depressed by the addition ofsulphur and sulphur monochloride less than the sum of the depres-68 E.F. Mueller and H. A. Burgess, J . Amer. Chern. Soc., 1919, 41, 745 ;59 R. de Forcrand and F. Taboury, Compt. rend., 1919, 168, 1253 ; 169,A,, ii, 446.162 ; A., ii, 341, 36646 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sions of these two taken separately.This points to the existenceof polythionic chloridee and the highest of these detected in bromo-form solution is S4Cl2. It is probable that chlorides richer in sul-phur are formed when sulphur is dissolved in the monochloride.It is suggested that the existence of these polythionic chloridesaffords an explanation of the formation of polythio-derivatives whenorganic substances are treated with sulphur monochloride.60In the Annual Report for 1913 the preparation was described ofthe fluorosulphonates and of sulphuryl fluoride. The ammoniumsalt, NH4S0,F, is most conveniently prepared by the gradual addi-tion of dry ammonium fluoride to sulphuric acid containing about70 per cent.of sulphur trioxide, and treatment of the product witha small excess of ammonia dissolved in methyl alcohol.61 The saltmelts at 245O and readily reacts with ammonia, especially at lowtemperatures, to form liquid ammines. The alkali metal salts areprepared by the action of the alkali hydroxide on the ammoniumsalt in aqueous solution. The following have been obtained:KSO,F, RbSOP, LiSO,F, and LiSO,F,SH,O. These salts can becrystallised from water if the operation is rapidly performed. Thealkali fluorosulphonates are very stable towards heat, thus thepotassium salt, when heated for some time, to bright redness, suffersonly slight decomposition, with the evolution of sulphur dioxide,sulphur trioxide, hydrogen fluoride, and oxygen. The barium salthas not been obtained in the pure condition and the crude salt isdecomposed at a red heat into barium sulphate and sulphurylfluoride.This affords the most convenient method for the prepara-tion of sulphuryl fluoride.The alkali fluorosulphonates possess the remarkable property ofexchanging the fluorine atom for an amino-group when treatedwith an aqueous solution of ammonia or substituted amine.62 Aportion of the fluorosulphonic acid depending on the strength ofthe base is hydrolysed to hydrogen fluoride and sulphuric acid,which may readily be removed by chalk or barium hydroxide. Inaddition to many substituted aminosulphonates the following havebeen prepared : aminosulphonic acid, barium hydrazinosulphonate,and potassium hydrazinosulphonate.This method of preparationhas the great advantage of not requiring the isolation of the basein the anhydrous condition.An important paper has appeared on the preparation and purifi-60 G. Bruni and M. Amadori, Atti R. Accad. Lincei, 1919, [v], 28, i, 217 ;61 W. Traube, J. Hoerenz, and F. Wunderlich, Ber., 1919, 52, [B], 1872 :68 W. Traube and E. Brehmer, ibid., 1284 ; R., i, 434.A., ii, 281.A., ii, 364INORGANIU UHEMISTRY. 47cation of selenious and selenic acids, and certain new selenium com-pounds are de~cribed.6~ Two sources of selenium were employed,namely, smelter flue-dust and anode slimes from a copper refiningworks. The flue-dust contained about 22 per cent. of selenium,small amounts of silica, iron, and aluminium, and a trace of tellu-rium.The flue-dust was finely ground and fused with sodiumcarbonate and sodium peroxide. The product was treated withwater and the insoluble material was filtered off. The filtrate wasthen nearly neutralised with concentrated hydrochloric acid whichprecipitated the greater part of the aluminium and zinc as hydr-oxides. The solution was filtered and the liquid diluted with threetimes its volume of concentrated hydrochloric acid and boiled for30 minutes to reduce the selenic acid to selenious acid. Any silicaprecipitated at this stage was removed by filtration. The filtratewas heated to 80° and treated with sodium sulphite and digestedat 80° for several hours to convert the selenium into the greymodification.The anode slimes contained 96 per cent.of selenium and a con-siderable amount of tellurium. The dry, finely powdered slime wasadded to concentrated nitric acid diluted with onefifth its volumeof water. After the vigorous reaction had moderated the mixturewas heated to complete the oxidation. The filtrate was evaporatedto drynem, the residue dissolved in hydrochloric acid (3 : 1) and theselenium precipitated by sulphur dioxide or sodium sulphite.Pure selenium dioxide was obtained by oxidation of the seleniumobtained as above with nitric acid and evaporation of the solutionto dryness. The, selenium dioxide thus obtained was sublimed ina glass tube, the vapours passing through a 2 cm. plug of glasswool.Pure selenious acid was prepared by the evaporation of the solu-tion obtained by oxidation of the anode slimes by nitric acid untilit had a syrupy consistency.The solution on being allowed to re-main deposited crystals of selenious acid, and these after fourrecrystallisations from water were found to be quite free fromtellurium .For the preparation of pure' selenic acid three separate methodswere employed. In the first silver selenite was oxidised by bromineaccording to the reaction Ag,SeO, + 2Br + H20 = H2Se0, + 2AgBr.The silver salt was suspended in the necwsary volume of water toyield a 3 per cent. solution of selenic acid, and bromine water witsadded until the, solution assumed an orange colour. After twohours the precipitated silver bromide was removed by filtration and63 L. M. Dennis and J.P. Roller, J . Amer. CTsena. Soc., 1919, 41, 949; A.,ii, 33648 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the excess of bromine removed by a current of air. Silver nitratesolution was then added to precipitate the hydrobromic acid andthe solution again filtered. The filtrate was then evaporated on asteam-bath to half its volume and then further concentrated undera pressure of 25 mm. at 120° to remove nitric acid. This processwas rendered necessary because it was noted that bromine waterwhen exposed to light gives considerable quantities of hydrobromicacid.The second method was the oxidation of selenious acid by chlorinein presence of copper carbonate, which dissolves to form cupricchloride and cupric selenate. After the reaction w u complete thesolution was filtered and evaporated t o a small volume at 65O.Oncooling cupric sslenate separated out and after recrystallisation fromwater the salt contained only 1-2 per cent. of cupric chloride. Thecrystals w0re dried in the, air and extracted with acetone in aSoxhlet apparatus to remove the cupric chloride. After one furtherrecrystallisation from water the cupric selenate was found to bepure. Selenic acid was obtained by cautious electrolytic deposi-tion of the copper.I n the third method the selenious acid was converted to selenioacid by anodic oxidation.It was proved that the electrolysis of selenic acid and its saltsunder the same conditions as are favourable for the formation ofpersulphates does not yield either perselenic acid or perselenates.Methods are described for the detection of small amounts of seleni-ous acid in selenic acid, as well as small amounts of sulphuric acidin selenic acid.Very delicate tests are given for the detection oftellurium in the presence of selenium. A method is also describedfor the estimation of selenium in selenates by the use of hydrazinehydrate.Copper selenate crystallises from its aqueous solutions with fivemolecules of water of crystallisation. This pentahydrate on heat-ing at 104O loses 4H,O and yields the monohydrate. Completedehydration is effected a t 230-235O, and the resulting anhydroussalt is stable up to 280O. When the pentahydrate is treated withacetone it is converted into the trihydrate.Certain ammonia derivatives of copper selenate are described,namely, CuSe0,,4NH,,Hz0, CuSe0,,3NH3,H,0, and CuSe0,,4NH3.A critical examination has been made of the precipitation oftellurium as the sulphide.64 When an aqueous solution of tellurousacid is treated with hydrogen sulphide the tellurium is precipitatedas TeS2, but from this substance after drying the greater part ofthe sulphur can be extracted by carbon disulphide.The fact that^64 A. M. Hageman, J . Amer. Chem. SOC., 1919,431, 329; A., ii, 190INORUANIC CHEMISTRY. 49about one per cent. of sulphur is retained has supported the con-tention that ordinary tellurium is not a pure chemical element, the‘suggestion being made that the retention of the sulphur is due tothe presence of a more basic element forming a more stable sulphide.There is no doubt that TeS, is initially precipitated, but that it is anunstable substance a t the ordinary temperature, dissociating intotellurium and sulphur.Below -20° TeS, is stable and the velocityof dissociation above that temperature increases as the temperatureis raised.The previous observations as to the impossibility of extractionof the total quantity of sulphur from the compound have been con-firmed. After extraction with carbon disulphide for nine days,followed by treatment with boiling alcohol for 30 days, the tellu-rium still retains a t least 0.95 per cent. of sulphur. This residualsulphur does not exist as a sulphide that can be decomposed byhydrochloric or hydrobromic acid, or as an allotropic modificationof sulphur insoluble in carbon disulphide.The question as to thecondition in which it exists still remains unanswered.It is shown that the monosulphide, TeS, which has often beendescribed, has no existence.Group VZI.For the preparation of fluorine the electrolysis of molten potass-ium hydrogen fluoride or sodium hydrogen fluoride is recorn-mended.65 The electrolysis is carried out in an electrically heatedcopper vessel which serves as the cathode. The anode is made ofgraphite and is enclosed in a permeable diaphragm, which preventsthe hydrogen from mixing with the fluorine. The most efficientconditions are obtained with a current of 10 amperes a t 15 voltsand a temperature of 240-250°, when t h e , current efficiency is+out 70 per cent.As the electrolysis proceeds, the alkali fluorideand copper fluoride are deposited, and after a time it becomes neces-sary t o regenerate the electrolyte. It is of course necessary thatthe alkali hydrogen fluoride be absolutely dry, and this is moreeasily realised with the sodium salt since the potassium salt ishygroscopic. The sodium salt has also the advantage in being lessexpensive. Moreover, it cont?ains a relatively larger proportion ofavailable hydrogen fluoride and it decomposes below its meltingpoint.The original investigations 66167 of crystallised sodium hypo-66 W. L. Argo, F. C. Mathers, P. Humiston, and C. 0. Anderson, J . Physicui66 M. Muspratt end E. Shrapnel-Smith, J . SOC. Ohm. Ind., 1898,17, 1096,67 M.Muspratt, ibid., 1903, 22, 691.Uhern., 1919,23, 348 ; A., ii, 332.1899 ; 18, 210 ; A., 1899, ii, 281, 63360 ANNU& REPORTS ON TEE PROGRESS OF CHEMISTRY.chlorite have been repeated.6* The salt was originally found tohave a composition corresponding. approximately with a hexa-hydrate NaOCl,GH,O. In the present investigation the hypo-chlorite solutions were prepared by treating 35 per cent. sodiumhydroxide solution, cooled in ice-water, with chlorine, removing theprecipitated sodium chloride, adding sodium hydroxide equivalentto the sodium chloride precipitated, and repeating the treatmentwith chlorine until the solution was about 5 N . The solution, whichhas been freed from precipitated sodium chloride, iS cooled to-loo and induced to crystallise by shaking. The sodium hypo-chlorite separata as a mass of very fine, hair-like crystals fillingthe whole liquid, whilst the temperature rises considerably.Whenthe whole has again been cooled to - loo the crystals are removed bysuction. Considerable difficulty was met with in the analysis ofthese crystals owing to the fact that they are +cry deliquescent andalso to the fact that they melt between 1 8 O and 19O. The analysesseemed to show that the salt approximates more nearly in composi-tion to a heptahydrate than to a hexahydrate, but further investi-gation may show that more than one hydrate is present.The heptahydrate melts to a cloudy liquid and if this liquid iscooled t o ordinary temperature large and well-f ormed crystals of a, newhydrate, NaOC1,5H20, are obtained, This pentahydrate, meltingat 27O, is also very deliquescent, but may be kept unaltered in awell-stoppered bottle.Aqueous solutions of hypochlorous acid containing 25 per cent.ofthe acid are readily obtained by distilling a mixture of chlorinehydrate and yellow mercuric oxide in a good vacuum.69 I n attempt-ing to prepare, a more concentrated solution or the anhydrous acidby distillation of this solution and condensation of the distillate inreceivers maintained a t Oo, -20°, and -80°, it was found that inthe first two flasks 25 per cent. hypochlorous acid was collected,whilst in the third pure chlorine monoxide condensed. It is evi-dent, therefore, that in the aqueous solution there exists the equili-brium, 2HC10 -7-t H20 + C1,O. This equilibrium has been investi-gated by agitating aqueous solutions of hypochlorous acid with car-bon tetrachloride at Oo.The equilihrium lies greatly in favour ofthe hypochlorous acid, for an approximately N / 5-solution contains0-2 per cent. of chlorine monoxide. It is probable that the greateroxidising properties of hypochlorites in acid solution are due to thepresence of chlorine monoxide,.The absorption spectra of hypochIorous acid, its ethyl ester and68 M. I?. Applebey, T., 1919,115, 1106.09 S. Goldschmidt, Ber., 1919, 52, [B], 763 ; A., ii, 227INORGANIC CHEMISTRY. 51metallic salts have been observed.70 Whilst the acid and ester havethe same absorptive power, the salts differ very materially and showwell marked absorption bands.This is interpreted to mean thatthe constitution of the salts and the free acid is different. Theauthors put forwardC1-0-H and thatequilibrium :the view that the acid has the constitutionthe sodium salt is to be represented by theSimilar differences are found in the case of the chlorites which givethe authors another opportunity of making the same suggestion,namely, that the free acid has the constitution 0 = C1- OH and thesalts the constitution Cl<&::*M. It is hardly necessary to mentionthat there is not the slightest evidence in favour of this fancifulsuggestion, and that the great mass of experimental evidence isagainst any such explanation. These substances form typicalexamples of the same nucleus, C10 - or C10,-, having differentenergy contents when in combination with hydrogen or an alkylgroup and with a metal. Another example is afforded by thenitrates.A convenient method has been described for the, preparation ofhydrobromic acid solutions in the laboratory.71 To 25 C.C.of potass-ium bromide (oontaining 15 grams of the salt) are added 0.2 gramof stannous chloride and 3.4 C.C. of concentrated sulphuric acid.By distillation a t 120-127O a solution of hydrobromic acid is ob-tained, free from tin and almost free from hydrochloric acid, theyield being 95 per cent.The red compound, CaOBr,,H,O, formed by acting on quicklimewith bromine and water in the proportion of 100 grams of lime,41 c.c of bromine, and 36 C.C. of water, on heating at looo losesbromine and water, and yields a new basic hypobromite,CaO,CaOBr,,H,0.72 This compound is a pale yellow powder andcontains about 33 per' cent.of available bromine.0.Growp V l l l .The solubility of the ammoaium salts of chloroplatinic, bromo-platinic, and chloroiridic acids in water has been determined a t a70 K. Schaefer and W . K6hler, Zeitsch. physikal. Chem., 1919,93, 312 ;A., ii, 207.71 A. Pickles, Chem. News, 1919, 119, 89 ; A., ii, 411.7' J. S. Arthur and L. G. Killby, Brit. Pat. 131750 ; A,, ii, 46552 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.number of temperatures.73 The platinibromide is somewhat morereadily soluble than the platinichloride, whilst the solubility of theiridichloride is nearly twice as great as that of the platinichloride.In the presence of ammonium chloride the solubility of ammoniumplatinichloride and iridichloride is much reduced, but that of theiridichloride is several times as large as that of the platinichloride.Similarly, ammonium bromide reduces the solubility of ammoniumplatinibromide.I n all three cases the reduction in solubility isproportional to the concentration of the ammonium haloid. Thedifference in the solubility of ammonium platinichloride and iridi-chloride furnishes a good method for the complete separation ofplatinum and iridium.The inhibiting influence of various substances on the absorptivepower of palladium for hydrogen has long been known, but onlyin a qualitative sense. The influence of hydrogen sulphide has nowbeen quantitatively determined and the observations have led to amost interesting and important result.74 I n the first place it wasnecessary to fix the conditions of experiment.Since the bulk ofthe absorbed hydrogen is evolved at looo in a vacuum, and sincealso it was advisable t o avoid the danger of changing the activityof palladium by heating, it was decided to fix looo the maximumtemperature a t which the metal should be heated.I n the second place it was necessary to determine the amount ofhydrogen evolved by a given quantity of palladium at looo, andalso the amount absorbed by this dehydrogenated palladium a tordinary temperature. This volume of hydrogen was found to be68-5 C.C. for one gram of palladium. On treating the dehydro-genated palladium with hydrogen sulphide it was found that in afew minutes the gas was rapidly absorbed up to about 13.5 C.C.pergram of palladium. This was followed by a slow and continuousabsorption of a secondary nature, the total volume of hydrogensulphide absorbed in 40 hours being 22.5 C.C. per gram of palladium.The hydrogen sulphide thus absorbed was not removed to any greatextent by exhaustion at ordinary temperatlure, this being especi-ally the case when the hydrogen sulphide content of the palladiumwas comparatively low, and on treatment of the palladium withhydrogen occlusion no longer took place.On heating the palladium containing hydrogen sulphide in avacuum at looo a volume of gas, approximately equal to that ofthe hydrogen sulphide contained in the palladium, was evolved.This gas, however, was found to consist almost entirely of hydrogen,78 E.H. Archibdd and J . W. Kern, Trans. Roy. SOC, Canada, 1917-1918,[iii], 11, 7 ; A., ii, 70.74 E. B. Maxted, T., 1919,115, 1050INORGANIC CHEMISTRY. 53the sulphur being retained by the palladium. An interestingobservation was made with respect to the specific influence of thesulphur absorption compound on the occlusive power of the palla-dium for hydrogen, in that, whilst about 13.3 C.C. of hydrogen sul-phide are sufficient completely to inhibit the occlusive power forhydrogen of one gram of palladium, the equivalent quantity ofsulphur, which remains behind after exhaustion at looo, is by nomeans sufficient completely to prevent the occlusion of hydrogen.The influence of the sulphur retained by the palladium after ex-haustion a t looo on the occlusive power for hydrogen wits quanti-tatively determined. The mean occlusive power is approximatelya linear function of the sulphur cont<ent, and each atom of sulphurrenders1 almost exactly four palladium atoms incapable of occlud-ing hydrogen, the remainder of the palladium being capable ofoccluding normally. This obviously raises the question of theformation of a definite sulphide of palladium, but, as the authorpoints out, there is insufficient evidence to justify such an assump-tion, and he mentions the fact that palladium foil remains untar-nished in pure hydrogen sulphide both a t the ordinary temperatureand at looo.There is no doubt that this result is one of great importance forit may be discussed from an aspect not mentioned by the author,namely, the catalytic activity of the hydrogen occluded by metals.There is little doubt that this activity is due to the supply by themetal of energy to the hydrogen molecules sufficient to dissociatethem into atoms. No quantitative data are to hand as regards thenumber of molecules of hydrogen activated by a given number ofmetallic molecules. The results described above would seem toafford the first instance of a definite quantitative relation, sincefour palladium atoms can supply sufficient energy to dissociateone molecule of hydrogen sulphide into a molecule, of hydrogenand an atom of sulphur. It is obvious, therefore, how it comesabout that more palladium is poisoned by a given volume of hydro-gen sulphide than is accounted for by the formation of the Pd,Scomplex. I n forming this complex one gram of palladium requiresabout 52.5 C.C. of hydrogen sulphide, and during the formation ofthis complex 52.5 C.C. of hydrogen are set free. This volume ofhydrogen will be absorbed by a further quantity of palladium whichwill then no longer have any power of absorbing hydrogen. It isnot possible from the evidence a t hand to calculate, the, equilibriumconditions which exist.If, however, Maxted’s figure for the poisoning of palladium byhydrogen sulphide is correct, namely, that one gram of palladiumis completely poisoned by 13.5 C.C. of hydrogen sulphide, the rela54 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.tive amounts of energy required to dissociate the molecule of hydro-gen into atoms and the molecule of hydrogen sulphide into hydro-gen and sulphur may be roughly approximated: 13.5 C.C. ofhydrogen sulphide in forming the complex Pd,S account for 0.257gram of palladium, and therefore, 0.743 gram of palladium isrequired t o activate 13-5 C.C. of hydrogen. Thus about 12 gram-atoms of palladium are required completely to activate one gram-molecule of hydrogen. Assuming that in each case the amount ofenergy available from each atom of palladium is the same, it followsthat three times as much energy is required to dissociate one mole-cule of hydrogen into atoms as is required to dissociate one mole-cule of hydrogen sulphide into a molecule of hydrogen and an ;tornof sulphur. On the energy quantum theory this would lead tothe conclusion that the frequency of the ultra-violet absorptionband of hydrogen must be about three times that of the absorp-tion band of hydrogen sulphide. E. C. C. BUY

ISSN:0365-6217    

DOI:10.1039/AR9191600026

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART I.-ALIPHATIC DIVISION.To have been responsible for a section of the Annual Report fora period of seven years, during the greater part of which thenormal course of research was interrupted by the war, has involvedon occasions the exercise of a capacity to make the most of limitedmaterial, but the facility thus acquired has not enabled the writerto disguise the fact that, in the past year, very little progress hasbew made in the aliphatic series. The difficulties recentlyencountered in dealing with publications describing unfinished ordisjointed work have been more acute than ever, and, if the ex-perience of one research laboratory is an index of the combinedexperience of laboratories in general, it is easy t o account for thestationary position of this branch of the subject.Researches which were in progress in 1914 have been completedand published in the interval, or, rather, have in many cases beenpublished without being completed, and there has been but littleopportunity to finish any new investigations commenced duringthe past twelve months.No doubt this state of affairs is transi-tory, yet it is safe to predict that the future topia of researchdealt with in this section will differ widely from those which havebeen discussed in the past. Chemists have altered their per-spective in the course of five critical years, and many may find itdifficult to revive an interest in compounds and reactions whichare harmless or have no market value. I f such be the case, andif utilitarian research is in any sense to overshadow scholarlystudy, the prospect is deplorable, and the aliphatic series will beone of the first t.0 suffer.This tendency of the times is already apparent in severalbranches of the subject where there is little of scientific interestto record.Other factors have, of course, been operative. Poli-tical unrest has terminated most of the valuable work on aliphatichydrocarbons, and must also bear the responsibility for many othergaps in the Report. I n addition, the death of Emil Fiacher will556 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.profoundly affect further progress in more than one branch oforganic chemistry, and a heavy task thus devolves on those whostill have the opportunity and still retain the desire to unravelthe mysteries of carbon compounds.It is hoped that’the pages of future Reporb will show that thisresponsibility has been realised and successfully undertaken.Hydrocarbons.There appears to be every prospect that, for some time to come,most of the investigations on aliphatic hydrocarbons will fall withinthe province of the Reports on Applied Chemistry.The numberof the publications dealing with these compounds certainly remainsvery much as before, but, for evident reasons, the topics examinedhave become more and more technical in their nature, and con-sequently, on the present occasion, discussion may be limited to acomparatively small number of papers.The somewhat confusing literature on caoutchouc problems, withits contradictory results and periodical corrections, has practicallyvanished from.the pages of the journals. I n addition, theresearches on the complex unsaturated hydrocarbons, whichformerly appeared regularly from Russian sources, have been com-pletely suspended, and these facts are in themselves sufficient torestrict the present section of the Report both in scope and variety.On the other hand, two distinct types of research on hydrocarbonscan be readily recognised as engaging most attention. One is theutilisation of natural hydrocarbon gases as sources of aliphaticcompounds, and the other, it need scarcely be said, is concernedwith the reactions of acetylene. Although in each type potentialtechnical application has been the directing factor, yet the resultsobtained are frequently valuable from the purely theoretical pointof view.Considering the somewhat wide range of the problems dealt within these investigations, it is practically impossible to preserve asystematic arrangement of the subject-matter, but as the ‘‘ crack-ing” of natural paraffins has been the object of a considerableamount of research, this problem may be dealt with in the firstplace.A number of simple saturated hydrocarbons have beenselected as test substances, and a general scheme has been putforward in which the conversion of such compounds into aromatichydrocarbons is claimed to proceed through the consecutive form-ation of simple olefines, and, in turn, of higher olefines with con-jugated bonds.It is not unimportant to note that, in the par-ticular cases studied, the presence of metals does not favour thOBUANIC CHEMISTRY. 57production of cyclic hydrocarbons, and they may even act asnegative catalysts promoting degradation.1 Attention has alsobeen paid to the conditions under which tars are formed in thecourse of these reactions, and it is possible that research of thisdescription may in time throw light on the nature of the complextars formed by the pyrogenic decomposition of lignified celluloses.This would, of course, involve systematic research conducted onvery unpromising materials, but, a t the present time, there appearsto be a distinct tendency t o focus on the problems of polymerisation,and it is well that such is the case.More than passing referencemay thus be made to a paper2 in which the production of nitro-ethylene from 8-nitroethyl alcohol is described, as the product isnot only very easily polymerised, but it has been possible to dis-criminate between reagents which promote the change and thosewhich retard or even inhibit it. Water proved to be highlyeffective, but much inferior to alkalis, whilst, on the other hand,acids were found to be without action. I n this particular example,the polymerisation is not reversible, and the same holds true inthe case of acetylene when the change is promoted by the actionof the silent electric discharge. I n this connexion, details are nowavailable3 as t o the experimental methods by means of whichacetylene can be subjected to graded polymerisation by varyingthe temperature a t which the gas is exposed to the discharge, anda striking feature of the products obtained is their ready oxidationand high degree of unsaturation.Whatever the nature of thesepolymerides may be, they are evidently far removed in structurefrom benzenoid hydrocarbons, and it would appear that the con-version of acetylene into benzene is by no means so simple a reac-tion as is generally believed to be the case. The idea has evenbeen put forward that, in pyrogenic reactions a t all events, theformation of benzene from acetylene is a secondary change and ispreceded by profound decomposition involving the separation ofcarbon. This is opposed to much experience, but the experimentson which the claim is made were carefully selected and were appar-ently carried out under highly accurate conditions.4 It is alwayssurprising that pyrogenic reactions of acetylene give definiteresults, considering the somewhat rough and ready manner whichcharacterises much of the experimental work of this nature.Nevertheless, the list of compounds formed in this way continuesto grow, and has now been increased by the recognition of o-xylene,*l J.G. Davidson, J . Ind. Eng. Chem., 1918,10, 901 : A., i, 10.a H. Wieland and E. Sakellarios, Ber., 1919, 52, [B], 898 ; A., i, 307.H. P. Kaufmann, Annalen, 1918, 417, 34 ; A., i, 117.5. Hilpert, @a. Abhand. Kennt. Kohle, 1917, 1, 271 ; A., i, 38058 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.indene, and mesitylene as authentic products.Even the pyrogeniccondensation of acetylene and hydrogen sulphide, to which refer-ence has been made in previous Reports, has yielded fresh resultsin that a-thiotolen and thionaphthen have been detected asadditional products of the complex readions.5Research which is more attractive to the structural and syntheticchemist, and will doubtless yield valuable results in the future, isconcerned with the nature of the compounds formed when acetylenecombines with mercuric chloride. There is no necessity to discussthe importance of a subject which is evidently the key to the variedreactions of the hydrocarbon under the influence of catalysts, andit now seems reasonably certain that the white compound obtainedas the principal product when acetylene, acts on mercuric chloridein an aqueous system is, in reality, trichloromercuriacetaldehyde,(ClRg),C*CHO. This view is not without its critics, and it hasrecently been suggested,C on the basis of a somewhat remoteanalogy, that the substance is an additive compound of vinylalcohol.In any case, it is evident that water must have played apart in its formation, and that i t arises from a simpler inter-mediate compound. Twenty years ago it was observed that asecond additive compound possessing the composition C2H2,HgC12is formed in small amount during the reaction, and it is nowshown that, by using an alcoholic solution of the metallic chloride,it is possible to obtain the above compound comparatively rapidlyand in good yield.Not only so, but the substance is well definedand crystalline, and, considering the yields obtained and the experi-mental conditions employed, there can be no question but that itrepresents the first and simplest additive product. Good reasonsexist for allocating to it the structural formula ClHg*HC:CHCl,and in view of its convenient solubilities and potential reactivity, itmay be described as a synthetic reagent with a future.'Although the reactions of acetylene have now become wellstandardised, novel types are occasionally forthcoming, and anexample is furnished by the observat.ion that tetranitromethanecan be prepared by absorbing acetylene in concentrated nitric acidin the presence of a mercury salt. Quite apart from the value ofthe process as a method of preparation, it would appear that thefirst actioh of the acid is to form an unstable compound, which istransformed into the nitro-paraffin when heated with acid.8 Oneof the most gratifying signs in recent organic research is the desireR.Meyer and W. Meyer, Ber., 1918, 51, 1571 ; A., i, 72.W. Mmchot, Annalen, 1918, 417, 9 3 ; A., i, 145.K. J. P. Orton, Brit. Pat. 125000; A., i, 247.' D. L. Chapman and W. J. Jenkins, T., 1919, 115, 847ORGANIU UHEMISTRY. 59to detect, and if possible identify, every intermediate compoundformed in reactions, and this policy must make for progress in theend.Alcohols and their Derivatives.It seems advisable to discuss all types of alcohols under oneheading, as the numbereof papers dealing with this branch of thesubject is much smaller than usual.So far as simple monohydricalcohols are concerned, there is little to report, but it may be men-tioned that it is now possible t o identify 8-aminoethyl alcohol withcertainty through the agency of a number of derivatives, theproperties of which render them suitable as reference substances.Considering the importance which is attached to P-aminoethylalcohol, work of this description is by no means valueless, although,in the paper referred to: another objective can be discerned, asit is impossible to disguise the fact that the synthesis of anzestheticsbased on the novocaine model was the main goal of the work.Now that the preparation of butyl alcohol by the fermentationmekhod has been elevated into a manufacturing process, researchin the butane series will be much facilitated.Fermentation butylalcohol is, however, a mixture, but it is possible to isolate the purenormal form by taking advantage of the fact that the sodium saltof butyl salicylate is easily crystallised, and may thereafter bedecomposed with water. The purified m-butyl salicylate thusliberated is then converted into the alcohol in the usual way.10Another paper describing results which may find application in thelaboratory is concerned mainly with the preparation of amylenefrom commercial amyl alcohol by the catalytic action of aluminiumoxide. Although practical directions are now provided wherebyuniform yields may be obtained, this reaction has already beenstudied in some detail, and perhaps greater importance should beattached to the description of a method by means of which amylenemay be converted into tert.-amyl alcohol displaying a high degreeof purity.11A considerable amount of work has likewise been directed towardsimproving the preparation of ally1 alcohol and of unsaturatedalcohols generally, but the results thus obtained do not appear tocall for detailed reference.Before leaving the subject, however,mention should be made of a paper in which it is suggested thatthe formulae at present assigned to a number of important repre-S. Frlinkel and M. Cornelius, Ber., 1918, 51, 1654 ; A., i, 66.lo K, J. P. Orton and D. C. Jones, T., 1919, 115, 1194.l1 R.Ad-, 0. Kamm, and C. 8. Marvel, J . Amer. Chem. Soc., 1918, 40, -1950; A., i, 6160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sentatives of the doubly unsaturated alcohol series should be com-pletely rearranged. Basing his views on the evidence provided bya number of transformations undergone by a-citral, the author 12proposes to assign to geraniol the constitution previously allocatedto citronellol, and also to apply Tiemann’s formula for geraniol tonerol. This does not exhaust the list of modified formulae, as, ifthe above changes are accepted, the constitution of linalool mustlikewise be altered; but the validity of the argument offered insupport of these suggestions cannot well be discussed briefly,although i t should be mentioned that the relationship betweengeraniol and dipentene is readily explained in terms of the consti-tutions now proposed.The saturated glycols have also been the subject of considerablestudy both in the laboratory and in the factory, where, with theobject of producing materials which may replace glycerol for indus-trial purposes, much attention has been paid to the preparation ofmixed glycols from waste petroleums.The initial stage is, ofcourse, the cracking of the hydrocarbons to give mixtures of olefines,which are then saturated with chlorine and the products hydrolysedto the corresponding glycols. Numerous patents and papers havedealt with this. problem, and one may be quoted13 in which theclaim is made that the nitrates prepared from these mixed glycolsdisplay properties which render them in some respects superior t onitroglycerine as the basis of explmives. I n quite a different field,a number of individual glycols have been studied with regard tothe molecular transpositions which they undergo when dehydrated,and a lengthy series of papers deals with a large number of freshexamples of such changes.14 Most of the glycols chosen as testsubstances are highly substituted by phenyl groups, and muchingenuity has been displayed in utilising the Grignard reagent inthe preparation of compounds of diverse type. As a general rule,dehydration of these glycols by means of sulphuric acid gives riseto either a ketone or an aldehyde, and although it is difficult todecipher any important generalisation or novelties in the results,appreciative reference should be made to the work in view of thethorough fashion in which each result has been confirmed.It is only natural that researches on glycerol should reveal thedirecting influence of the technical importance of the compound,and it is gratifying t o note that many investigations conducted inthe factories display a very high standard.The technical pre-1s A. Verley, Bull. SOC. chim., 1919, (iv], 25, 68 ; A., i, 146.1s H. Hibbert, Met. and Chem. Eng., 1918, 19, 571 ; A., 1918, i, 521.l4 A. Orhkhoff, Bull. SOC. chim., 1919, [iv], 25, 108, and succeeding papera ;A,, i, 205ORUANIC CHEMISTRY. 61pbrhtion of the compound, more particularly by fermentationmethods, has recently been prominent, and although this subjectdoes not fall within the limits of the present section of the Report,it is interesting to note how, one by one, the methods are beingdisclosed whereby the Powers were enabled to supplement theirsupplies of glycerol during the War.Reference may, however, bemade to one factor which is doubtless of more than passing import-ance-the fact that the fermentation of sugar by means of aspecially resistant yeast is greatly affected by the presence of areducing agent, such as sodium sulphite. I n this way, the yield ofglycerol is much increased, a result which is in harmony with theview that glyceraldehyde and dihydroxyacetone are the essentialintermediate products in ordinary alcoholic f ermentation.15.16Before leaving the subject of glycerol, attention should bedirected to the application of spectroscopic methods to the problempresented by the existence of two crystalline modifications ofglyceryl trinitrate.17 It is now established that both forms giveidentical spectra in aqueous solution, and this disposes of the possi-bility of the two varieties representing chemical isomerides. Thisconclusion has been well supported by the spectrographic examin-ation of the complete series of partly nitrated glycerols, where, ofcourse, two isomerides are possible in each case, and do exist.Fresh progress has to be reported in the consecutive scheme ofinvestigations on optically active glycerol derivatives carried outby Abderhalden and his co-workers.Undaunted by many difficul-ties, they have continued their synthetical work with unflaggingzeal, and have now succeeded in obtaining the d- and E-varieties ofa glycerophosphoric acid, which has been isolated in the form oflithium salts displaying opposite activities.18 The method employedwas to introduce the phosphoric acid residue by acting on a pyridinesolution of d-a-bromohydrin by phosphoryl chloride.The productwas thereafter treated with water, and then followed a tediousseries of operations designed 60 remove halogens and pyridine andt o obtain crystalline glycerophosphates. There can be no doubt asto the success of the scheme, as lithium glycerophosphate wasultimately obtained in d- and Z-forms, the activities of which arein fair agreement, taking into account the tendency shown by suchcompounds t o form an epihydrin phosphate.The same authors19 have also undertaken the preparation of1 6 I(. Schweizer, Helv.Chim. Acta, 1919, 2, 167 ; A., i, 239.l* W. Connstein and K. Ludecke, Ber., 1919, 52, [B], 1385; A., i, 463.H. Hepworth, T., 1919,115, 840.E. Abderhalden and E. Eichwdd, Ber., 1918, 51, 1308 ; A., i, 3.lS Ibid., 1312 ; A., i, 262 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.active propylene glycol with the object of synthesising active fatsshowing a specific rotation sufficienily large to enable enzymehydrolysis to be studied polarimetrically with a fair degree ofaccuracy. As is frequently the case with compounds of simplemolecular magnitude, the experimental difficulties were consider-able, and although active propylenediamine was obtained, the com-pound proved ineffective as a source of the desired active glycol.An outline of the method which proved successful is given belowas an index of the many variations which are frequently necessaryin synthetical work of this description.Allylamine .?$ P-chloro-12-propylamine acid + d-/3-chloro-n-propylamine d-tartrate ?!?$ d-P-chloro-a-propanol -+ d-propyleneoxide _"c! d-propylene glycol.Unfortunately, the di-esters of the glycol do not appear to dis-play large rotations, but the work may nevertheless prove useful inthe future, and already an additional application of active proppleneoxide has to be recorded in that the compound has been used asthe indirect source of I-P-hydroxybutyric acid.A structuralscheme has thus been formulated to show the configuration of thisacid, and its relationship to Z-alanine, but, as in all such cases, thevalidity of the argument is dependent on the, unknown factor as towhether or not optical inversions take place during any of thereactions involved.As, on the present occasion, the number of publications on thechemistry of esters is too small to justify their discussion under aseparate heading, it may be well to include a t this stage referenceto a highly suggestive paper20 in which the hydrogenation of un-saturated fats is presented in a new light. That this importantchange, when promoted by the catalytic agency of metals, shouldshow a general resemblance to enzyme action was doubtless to beexpected, but the close analogy now displayed between hydrogen-ation and the enzymatic hydrolysis of glucosides is particularlystriking.The most significant result revealed by a study of thetime-absorption curves is that an unstable complex is formedbetween the catalysing metal and the unsaturated fat. This a tonce brings the reaction into line with standard cases of enzymehydrolysis, where similarly it has been shown that temporarycombination of the catalyst is an essential feature.137 ; A., ii, 403.KOH2O E. F. Armstrong and T. P. Hilditch, Proc. Roy. Soc., 1919, [A], 96ORGANIC CHEMISTRY. 63Aldehydes and Ketones.Although numerous papers dealing with the reactions ofaldehydes and ketones have appeared during the past year, practic-ally the whole of this work has been conducted on aromatic com-pounds, and although the results described are not without import-ance, it is impossible to discuss them in detail in this section.Accepting this restriction, there is but little left to report, withthe exception of isolated researches which involve some fundamentalpoints.F o r example, a return has been made to the problem ofclassifying ketones according to the relative reactivity of thecarbonyl group present, and reference may be made to two papersdescribing work of this nature. Thus, the condensation of a ketonewith ethyl cyanoacetate in the presence of an amino-compound isnot a general reaction, and may be either imperfect or completelyinhibited, according to the constitution of the ketone chosen.21This represents, of course, merely a rough and ready classificationof ketones in terms of one particular reaction, and is incapable ofexact treatment.On the other hand, it is possible to classifyketones according t o the quantitative reactivity of the carbonylgroup through the use of semicarbazide as a test reagent. I n thepaper now referred to,22 a distinction is properly drawn betweenreactivity and instability, and the idea is put forward that acarbonyl compound can react with a salt of semicarbazide only afterliberation of the free base. If this point be conceded, it followsthat the reactive power of any particular ketonic group may begauged either by using salts of sernicarbazide with acids of varyingstrength or by the addition of excess of an acid fa the correspond-ing salt until a point is reached a t which semicarbazone formationis inhibited owing to reverse action.The idea is ingenious, andhas been applied t o a series of aliphatic ketones, of which propylisopropyl ketone was found to be the most stable and methyl octylketone the most reactive. I n this case, also, the classification isbased on the behaviour towards one reagent, and the order inwhich the ketones are arranged in terms of increasing reactivitydoes not correspond with that deduced from their behaviour withphenylhydrazine, but this does not interfere with due appreciationof a somewhat unique paper and with the prospects opened out ofseparating closely related ketones by graded reaction.The only advance which has been noted in synthetical reactionsinvolving aldehydes is a new method for obtaining aedialdehydesor the corresponding keto-aldehydes.The process depends on the21 I. Guareschi, Gazzetta, 1918, 48, G , 83 ; A., i, 94.22 A. Michael, J. Amer. Chern. SOC., 1919,41, 393 8 A., i, 2 s 64 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.alkaline condensation of (a) a ketone or ( b ) an aldehyde with anethylenic aldehyde, according to the equationsCH,R*COR + CHR:CH*CHO = COR*CHR*CH;R*CH,*CHO,CH2R*CH0 + CHR:CH*CHO = CHO*CHR*CHR-CH,*CHO.It is true &at the examples illustrating the above changes havebeen selected entirely from t'he aromatic series, but the experi-mental details provided seem to indicate that purely aliphatic com-pounds may also be included within the scope of the general scheme.I n any case, the paper in question23 deserves mention, if only forthe light which it throws on many of the tangled resultsencountered in reactions conduct<ed on the diphenylethane series.The general problem of the conversion of aliphatic ketones intocyclic structures never seems to lose its attraction, but of severalpapers on this subject which have been published during the year,discussion may be limited to 0118.24S CN*CH,* CO CIA,,which has now been obtained in a purer condition than hit.herto,has been subjected to the action of simple reagents, and, as aresult, entirely new ideas are available as to the constitution ofcompounds previously regarded as thiazole derivatives.Thus, onsaturating thiocyanoacetone with hydrogen chloride, it is convertedinto 2-chloro-4-methylthiazole (11), a result which is consistentwith the view that the ketone reacts in one of the possible enolicformsThiocyanoacetonep - y\/--i, CIJ,*C CCI RH-5 CH;C cb H N N(1.) UJ.1It is, however, conceivable that the tautomeride (I) might undergorearrangement, involving transference of hydrogen to nitrogen,followed by the closing of the ring through oxygen. Should thisoccur, the fundamental structure a t once diverges from the thiazoleconstitution, and a series of derivatives should exist related to thefiH-? CH,-C C:NH .\/0The name " rhodim" is suggested for this class of substance, andit is now shown that three methylrhodims are readily formed, one2s H.Meemvein, J . pr. Chem., 1918, [ii], 97, 225 ; A,, i, 21.24 J. Tcherniac, T., 1919,115, 1071ORGANIC CHEMISTRY. 65of which is the compound previously regarded, on very insecureevidence, as hydroxymethylthiazole. This does not exhaust thecorrections introduced in a highly interesting paper, as, conharyt o Hantzsch’s statement, the action of ammonia on thiocyano-acetone does not give rise to aminomethylthiazole, although theexperiment has been repeated on a generous scale and underconditions favourable to the formation of such a qompound.Acids and their Derivatives.I n last year’s Report, mention was made of the method ofidentifying common acids through the agency of their p-nitrobenzylesters, and this useful type of work has now been extended by theapplication of o-bromoacetophenone as a reagent.The propertiesof the phenacyl esters thus obtained are, on the whole, more suit;able than those formed from p-nitrobenzyl bromide for the charac-terisation of aliphatic acids. It is now possible to select either ofthese reagents, the choice being determined by how far the meltingpoint of the expected product is removed from that shown by closelyrelated compounds.25Before considering more complex subjects, a general paper 26 onthe oxidation of organic compounds by means of silver oxide maybe noted. The subject-matter of the research is naturally as muchconcerned with alcohols as with acids, but a number of widegeneralisations are drawn which reveal the conditions favourableto the formation of carboxy-compounds under mild conditions.Thus, in an alkaline system, silver oxide functions as an oxidiserwhen any two of the groups*CH2-OH, :CH*OH, or *CO,Hare combined with:CH*OH, :CO, or :C(OH),.On the other hand, in neutral or acid systems, oxidation proceedswhen the secondary alcohol group is united to *CO,H, CH,., :CHz,or even H.It is of importance to observe that, in alkaline media,increase in the concentration of alkali affects only the speed of thereaction and not the nature of the products or the proportions inwhich they are formed. I n order to appreciate fully the signifi-cance of these results, it is necessary to compare them with thoseobtained by Nef in his monumental research on the oxidation ofcarbohydrates by means of Fehling’s solution, when it will be seenthat both inquiries have led to very much the same conclusions.86 J.B. Rather and E. E. Reid, J . Amer. Chem. SOC., 1919, 41, 75 ; A.,i, 167.86 R. Behrend and K. Dreyer, Annalen, 1918,416, 203 ; A., i, 64.REP.-VOL. XVI. 66 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It must be a common experience to find that entirely new ideaspresent themselves when the constitution of a compound is referredto a structural model different from that usually adopted. Asugar, for example, almost ceases to be a sugar when it is describedas a derivative of tetrahydrofuran, but it is occasionally soundpolicy and a safeguard against impressions becoming stereotypedto regard a carbohydrate in this light.A somewhat similar case,which has the merit of simplicity, has recently been furnished, asit has been painted out27 that maleic anhydride bears the samerelationship to furan as benzoquinone to benzene. The analogy,although imperfect, is fairly well maintained, and extends to theproperty of the anhydride to give coloured solutions in certainsolvents. The effect of saturation or substitution, respectively, todiminish and intensify this property supports the view that a fairparallel exists between the unsaturated anhydride and quinone.The combined results are suggestive, and certainly worthy ofattention.The constitutional problems presented by the glutaconic acidsare by no means simple, but, as a result of the systematic researchesof Thorpe and his co-workers, it has been possible for some yearsto provide an adequate explanation of the isomerism displayed bythese compounds.Reference to the Annual Reports for 1912 and1913 will indicate the stage which had been reached when theseinvestigations were interrupted by the War, and it will be recalledthat the three isomeric types of a substituted glutaconic acid maybe represented by the formulaeRR*CO,H FR*CO,H fiR*CO,HCR CHR CRCO,H*bHR -LR-CO,H &H R-CO,Htrans-Labile form. Normal form. &-Labile form.These formulze are based on numerous reactions, but it is never-theless difficult to substantiate the structure shown above for thenormal type by the production of evidence that addition in the1:S-positions can take place.Even the reaction with bromine,which proceeds regularly with the labile isomerides, does not takeplace without molecular rearrangement when applied to a normalform. I-n the case of the corresponding esters, however, it ispossible to discriminate sharply between the normal and labiletypes, and, a t the same time, to confirm the structure assigned tothe normal form by taking advantage of the reaction with ethylsodiocyanoacetate. Hitherto, the opinion has been held that,whereas a labile ester reacts smoothly with this reagent, a normal2' P. Pfeiffer and T. Bottler, Ber., 1918, 51, 1819 ; A., i, 62ORGANIC CHEMISTRY. 67form is incapable of reaction except under conditions which pro-mote transformation into a labile isomeride.This view can nolonger be maintained, as it is now shown28 that the ethyl ester ofP-methylglutaconic acid does actually enter into condensation withethyl cyanoacetate to give a small yield of the 1 : 3-additive pro-duct. There can be no doubt that the addition did involve theterminal carbon atoms, as the product, when hydrolysed, was con-verted into y-methylbut,ane-aPG-tricarboxylic. acid, the constitutionof which was known.CH,*CO,Et C H,*CO,HCH*CO,EtI AHMe L H M ~ CHMe + CH,(UK)*CO,Et --+ I + I 6 H *CO,E~ IC'H C0,E t C'H*CO,HbH(CN)*CO,Et UH,-CO,HThis result, which supplies valuable confirmation of the structuralideas frequently expressed in this series of papers, was not obtainedwithout considerable experimental difficulty.To turn to another topic, i t may be mentioned that some featurwof general interest are presented in what is presumably the firststep in a survey of the properties of aliphatic compounds in whichthe principal carbon chain is highly substituted by shorter chains.For example, a reaction so well explored as the condensation of aketone with the ester of an a-iodo-acid does not always proceed insuch a manner as to produce a hydroxy-derivative, as it is nowfound that the corresponding olefinic compound may be formedsimultaneously. This has opened up a route to the synthesis ofaSyG-tetramethylhexoic acid, CH,*[CHMe],-CO,H, and the generalinvestigation has incidentally furnished Willstatter 29 with anumber of new lactones or anhydro-acids which may possibly findapplication in the varied problems studied by him, even i f theirimportance is not apparent a t the present time.With regard to the metallic salts of aliphatic acids, it is evidentthat the pyrogenic decomposition of these compounds still con-tinues t o be a favourite topic of research, but, of numerous papersdescribing such work, reference need be made to only 0118.3~ Anattempt has been made t o classify the metallic formates accordingto the temperature conditions under which they decompose t o giveformaldehyde, and also according t o their capacity to yield methylalcohol and acetone, which are the outstanding secondary productsof the reaction.The combined results are of importance in con-nexion with the preparation of aldehydes by the dry distillation2* J.F. Thorpe, T., 1919, 115, 679.29 R. Willstiitter and D. Hatt, Annalen, 1919, 418, 148 ; A., i, 431.80 K. A. Hofmann and H. Schibsted, Ber., 1918, 51, 1398; A., i, 7.0 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.method, as it has been shown in the course of the work that zincformate is the most suitable substance for the production of form-aldehyde.It is impossible to leave the consideration of metallic salts with-out reference to a type of investigation which, although moreappropriately dealt with in another part of the Report, has been inthe past the object of appreciative reference in this section. Inrecent years, our ideas on the nature of soap solutions have alteredprofoundly, largely owing to the discovery that such solutions dis-play an unexpectedly large conductivity in concentrations wherethe result cannot be attributed to hydrolysis.The explanationwhich has been put forward to account for this behaviour is thatan aggregation of charged ions forms the nucleus of the colloidalparticle, and that the system thus produced, termed the “ionicmicelle,” is responsible for a large proportion of the conductivity.The general terms of this theory have frequently been expressedin the, course of a lengthy series of investigations on soap solutions,and in the latest contribution31 it has been formulated in greaterdetail and supported by a series of conductivity, f reezing-point,and vapour pressure determinations carried out on solutions ofpure soaps a t ordinary temperatures. A study of the results, andmore particularly of the form of the conductivity curves, showsthat the theory accounts adequately for the known facts, and, inview of the increasing importance now attached to the electricalcondition of colloids, its elaboration is both important andopportune.Halogen Compounds.I n normal times, difficulty was always encountered by thereviewer in any attemph to discuss researches on halogen deriv-atives under one general heading, as the synthetic applications ofthese compounds penetrate into every branch of the subject.Thepast year has, however, been exceptional, as, in the aliphatic seriesa t least, the use of halogen compounds in syntheses has not onlybeen restricted in scope, but presents no feature of novelty.Onthe other hand, several papers have dealt with improved methodsof preparing simple haloids, and reference may be made to someexamples which may reasonably be expected to find application inthe laboratory.The general development under which petroleum gases are nowbeing used as the starting material in the preparation of fattycompounds of varied type has been extended to the formation ofJ. W. McBein, (Miss) M. E. Laing, and A. F. Titley, T., 1919, 115, 1279ORGANIC CHEMISTRY. 69simple aliphatic haloids. For example,32 a natural gas consistingprincipally of methane containing a small proportion of ethane,has been found t o undergo progressive substitution when, in admix-ture with chlorine, it is passed through a heated tube containinga suitable catalyst.It is not surprising to find that, in the searchfor a catalysing medium, anti-gas charcoal was tried and found tobe highly effective, but, of necessity, the process gives mixtures ofchloro-compounds, although it appears possible to grade the reac-tion so as to yield either carbon tetrachloride or chloroform as theessential product. So far, this method of chlorination has beenconducted with comparatively small quantities of material, but itis probable that it may be developed into large-scale working, and,i f so there are many outlets for the mixture of chlorides whichmay thus be obtained. It is, however, doubtful if the method cancompete with the parallel process in which petroleums are crackedto give olefines, and these are converted in turn into the corre-sponding dichlorides, as, in each case, the products are mixturesand will probably be used mainly as solvents.Another method of preparing aliphatic chlorides, the utility ofwhich is equally doubtful in view ‘of the fact that mixtures ofisomerides are formed, depends on the direct action of hydrogenchloride on an alcohol, the mixed gases being led over aluminiumoxide a t a moderate temperature.Scrutiny of the resultsobtained 33 shows that, under these conditions, the tendency of thealcohol to pass into the corresponding olefine cannot be altogetherexcluded, and thus the products, except in the simplest cases, arenot individual compounds, but contain secondary, and eventertiary forms in addition to the primary chloride. Of greaterimportance from the point of view of laboratory working is theaccount of an improved method for preparing alkyl iodides.34 Theprocess is really a modification of that recommended by Walker, asthe appropriate alcohol is boiled in contact with a mixture ofyellow and red phosphorus, the iodine being introduced by means ofthe refluxing liquid.The working details supplied in this latestcontribution to the scheme for facilitating the laboratory pre-paration of research reagents will be welcome, as it is a distinctadvantage t o have a safe and economical method of preparing thesimple iodides a t the rate of several kilograms a day.It is evident that, despite prolonged investigation, the complica-sa G.W. Jones and V. C. Allison, J . I d . Eng. Chem., 1919, 11, 639; A.,s3 P. Ssbatier and A. Mailhe, Compt. rend., 1919, 169, 122 ; A., i, 430.34 R. Adam and V. Voorhees, J . Amer. Chem. Xoc., 1919, 41, 789; A * ,i, 429.i, 30670 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tions encountered in attempts to1 prepare chloroform by electrolyticmethods are far from being removed. Great possibilities are con-tained in such a process, but the usual practical difficulties regard-ing the choice of the most favourable conditions of current density,temperature, and concentration are increased by the fact that theaccumulation of alkali a t the cathode has the effect of decomposingthe liberated chloroform.By the adoption, however, of a neutral-isation electrode it is possible35 to minimisu this loss, but neverthe-less the method is complicated and somewhat uncertain in itsresu1t.s. Even under carefully standardised conditions the yieldsof chloroform obtained from acetone are throughout inferior t o thosegiven by alcohol when the electrolysis is conducted in the presenceof the chlorides of alkali o r alkaline-earth metals. This is not sur-prising in view of the fact that when alcohol is employed the firststep of the reaction is the formation of acetaldehyde, the conversionof which intol chlosoforrn by means of calcium hpochlorite isstated 36 to be instantaneous and quantitative.As already mentioned, no1 novel synthetical uses of halogen com-pounds have been noted, but a passing referenoe may be made tosome complicated results which have been obtained by the inter-action of magnesium phenyl bromide and halogenated ethanes.Theessential feature of these reactions is the fact that when substitutionof the paraffin molecule has been effected by different halogenatoms, these are in part eliminated under the action of the reagent.Although little uniformity can be discerned in these results, thOinrestigation will prove useful to those who have occasion to actwith Grignard reagents on pdy-halogen compounds.37 Greater satis-faction will be found in the study of an investigation 38 in which theaction of Grignard reagents on the esters olf aliphatic dib<asic acidshas been controlled, so that the change is limited to one carboxy-alkyl group.A considerable amount of attention has in the pastbeen paid to the1 problem of modifying the Grignard reaction, soas t o attack preferentially one of two groups which are apparentlysymmetrical. I n the case of di-esters, complete reaction on normallines should give a ditertiary glycol or a closely related compound,and practically without exception results of this nature have beenobtained when compounds of the type of diethyl oxalate, malonate,or succinate are subjected t o the action of Grignard reagents. Itis now shown, however, that the limitation of the reaction to oneposition is largely a matter olf restricting the proportion of mag-85 J. Feyer, Zeitsch. Elektrochem., 1919, 25, 115 : A., i, 305.38 S .Utheim, Brit. Pat. 116094; A., 1918, i, 521.3 7 F. Swarts, Bull. SOC. chim., 1919, [iv], 25, 145 ; A., i, 247.3 8 H. Hppwcrth, T., 1919,115, 1203ORGANIC CHEMISTRY. 71nesium alkyl haloid employed, although the special method adoptedto' incorporate the reacting substances may also be a factor. I n thisway it has been possible tol prepare a-hydroxy-a-ethylbutyric acidfrom ethyl oxalate and magnesium ethyl bromide, and this singleexample will be sufficient to illustrate the1 nature of the reaction.This appears to be perfectly general, as the only exception encoun-tered in a number of test cases was that of ethyl malonate, whereenolisation interfered with the normal coarse of the change.It is always of interest to encounter transformations from thealiphatic to the aromatic series which can be described as synthesesin the best sense of that expression, and another examples9 has beenadded to the existing 'list in that malonyl chloride reacts withacetone with the elimination of two molecular proportions of hydro-gen chloride, and the formation of phloroglucinol as the essentialproduct.The blackboard representation of 'this reaction will doubt-less, 'on account of its simplicity, find application in the lecture-room,and it is more than probable that an intermediate product formedin the condensation will prove useful in the laboratory, if the con-stitution assigned to1 it, namely, C'H,~CO*CH2*CO*CH,*COC1, iscorrect. A compound which has a six-carbon chain, is a diketone,and also an acid chloride is a t once stamped as embodying endlesspossibilities.Optical Activity.The idea was expressed i n last year's Report that it is inadvis-able to limit the1 review of optical activity entirely to examplesselected from the aliphatic series, and on the present occasion effectis given to1 the suggestion then put forward that all types of o'pti-cally active compounds should be discussed.It is difficult to1 presentthis subject in any order which has the merit of logical continuity,and, in such a case, it may be well to begin by an account of newresolutions which have been effected during the year. Of severalexamples, most interest will be attached to1 the revised specificrotation of tropic acid, the two active farms of which have beenisolated under conditions which guarantee their optical purityCuriously enough, this has been achieved in the course of twoseparate investigations which differed widely so far as the initialtopic of research was concerned.With regard t o one of theseinquiries it must be admitted that the detailed stereoohemistry ofthe alkaloids is beyond the scope of this section of the Report, buti t should nevertheless be stated that a distinct advance has beenmade in characterising two out of the eight possible activeT. Komninos, Compt. rend., 1918,167, 781 ;:A,, i, 672 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hyoscines. Starting from the feebly active hydrobromidm obtainedin the manufacture of Z-hyoscine, the d-form has been isolatedthrough the agency of d-u-bromol-?r-camphorsulphonic acid. In addi-tion, ghyoscine was hydrolysed, not by alkali, as is usually the case,but by means of acid, and in this way Z-tropic acid was obtained,displaying an activity somewhat higher than the standard valuehitherto hccepted. It was thus desirable h repeat t h O resolutionof tropic acid so as to establish the maximum rotatory power, andthis was accomplished by the successive use of quinine and quin-idins.40 By a coincidence1 the values obtained by King were con-firmed in the course of an investigatioa,41 in which the standardsynthetical methods of preparing r-tropic acid have been tested andfound to be in many respects unsatisfactory.Exact working detailsare now provided, by means of which the colmpound may be obtainedi n good yield by the operation of a synthetical scheme in whichacetophenonecyanohydrin is the starting material.I n resolving theacid, quinine was used ta separate the d-form, and morphine wasfound to give the most satisfactory results in the isolation of theoptical isomeride. The rotatory powers od this important acid havethus been established with a high degree of accuracy.Turning to reactions conducted on optically active compounds,Abderhalden’s recent work on derivatives of glycerol has alreadybeen dealt with, so that it is psesible to pass t o the considerationof examples which illuslxate in holw far the mechanism o t reactionsmay be indicated through a study of optical changes.On firstinspection the subject of racemisation does not, appear t o be apromising source of new ideas regarding the prooess of ester hydro-lysis, but. nevertheless the! complexity of such changes is wellrevealed by considering the optical eff ecta encountered in hydrolys-ing ethyl Z-mandelate under different conditions .42 It may now beregarded as a general rule that alcoholic potassium hydroxide exer-cises a more powerful racemising elffeet than aqueous alkali in thehydrolysis of an active ester, and the result cannot be attributedto the action of the alkali on the liberated acid, as this is a, minoreffect compared with the direct racemisation of the non-hydrollysedester. It follows that the mechanism of hydrolysis is differentaccording as aqueous or alcoholic alkali is used, and it is reasonableto assume that potassium ethonide rather than potassium hydroxideis to be regarded as the essential racemising agent.It is now sug-gested that, in the case of aqueous hydroxide, an additive compoundis formed which afterwards loses the elements of alcohol, and thusH. King, T., 1919, 115, 476.A. McKenzie and J. K. Wood, ibid., 828.A. McKenzie and H. Wren, ibid., 602:; A., i, 326ORGANIC CHEMISTRY, 73gives the potassium salt directly as shown below in the specificexample of ethyl Lmandelate :OH OH OH. . . .____... 8(1.1 (11.) (I=)As the groups added and eliminated are not immediately connectedwith the asymmetric carbon atom, it follows that if (I) is lzvorota-tory, (111) will be active in the same sense. On the other hand,when alcoholic potassium hydroxide is employed it may be assumedthat the above compound (11) is replaced in part by (IT), so thatthe elements of alcohol can be eliminated only by the formation ofOH OH/\OK OEtw .1 w.1the unsaturated type (V). In the presence of water this would passinto the two active forms of mandelic wter, and as the5e would beproduced in equal amounts total racemisation would result. Thetheory is in harmony with the facts, and explains the partial race-misation of the non-hydrolysed ethyl Lmandelate which remainswhen the pure active ester is treated with alkali in insufficientamount t o cause complete hydrolysis. The combined results andthe use which has been made of them constitute a g o d example ofthe application of optical methds in tracing the mechanism ofreactions generally regarded as simple.In an entirely different field, optical changes have been used toexpand our ideas regarding the reactions of the halogenated suc-cinic acids.I n this work, Holmberg has frequently emphasised theidea that the removal of halogen from them compounds involvesthe transient formation of active malwlacbne,CO,H*CH *CH,*CO.The existence of such a lactone has been predicted largely from theresults (of physical measurements, but the compound has now beenisolated in r- and d-forms. This has been possible through thepreparation of pure iodoauccinic acid, the optical behaviour ofL - 0 1D74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which, it may b mentioned, is very similar t o that displayed bythe corresponding bromo-compound.*3 When treated with silveroxide and water 6-malo-lactone was farmed, and the properties ofthis product agree closely with those ascribed to it before its isola-tion had been acoomplished.Thus, when the lactone ring wasopened by means of acid some racemisation took place, but the malicacid produced contained excess of the Z-form. With alkali no race-misatioa occurred, but d-malic acid was alone prlduced.44 Thisresult must be regarded as highly satisfactory, as is also the factthat the views formerly expressed45 as to the reaction betweenZ-brcrmosuccinic acid and potassium xanthate have now been experi-mentally confirmed.46It is inevitable that papers which involve closely sustained andoontinuous argument cannot readily ble reviewed within the narrowcompass of the Reports, and this applies t o the latest contribution 47to the vexed question of the causes which are responsible for anoma-lous dispersion.Sttention is thus directed to the original paper,which deals with the rotation dispersion of the higher ethereal tar-trates, and introdurn a number of azguments opposed to the viewthat abnormal dispersion is to be attributed t o the co-existence ofdynamic isomerides displaying different rotatolry powers. It isequally difficult to do justice to1 another paper,** which deals witha new quantitative generalisation governing optical activity in thes u g a group.The number of acid amides related t o the sugarswhich have been obtained in a pure condition has recently beenincreased, and, as pointed out last year, the optical activity of suchcorr,poands is largely dependent on the configuration of the groupsattached t o the a-carbon atom. It is now possible, through theanalysis of the rotations shown by the acid amides from the C4 tothe C, series, to ascribe a quantitative value to the optical effectcontributed by the afly8-asymmetric systems of a sugar. This mayappear to1 be a bold claim, particularly as the generalisation dependson the exact application of the principle of superposition to sugars,but, at the same time, it is evident that the values now quoted willserve as a valuable guide in determining the constitution of partlysubstituted aldoses and in indicating which hydroxyl group has beensubstituted.B.Holmberg, Arkiu Kern. Min. Geol., 1917,6, No. 23,33 ; A., 1918,i, 623.44 B. Holmberg, Svensk. Kem. Tidskr., 1918, 30, 190, 215; A., i, 309.45 Ann. Report, 1917, 83.46 B. Holmberg and R. J. Lenctnder, Arkiv Kern. Min. Geol., 1917, 6, No.47 P. F. Frankland and F. H. Garner, T . , 1919,115, 636.‘r4 C. S. Hudson and S. Komatsu, J. Arner. Chem. SOC., 1919, 41, 1141 ;17, 26 ; A., 1918, i, 529.A., i, 524ORGANIC CHEMISTRY. 75The first step in what may prove1 to be an inquiry of considerablesignificance in biology is marked by the preparation of d- andLforms of simple dyes containing an asymmetric ~ystem.4~ The workhas not proceeded far, but evidence has already been obtained thatthem optical isomerides are selectively absorbed by wool, and theprospect is thus opened out that they may ultimately be used in thestaining of sections so as to reveal more completely the chemicalconstitution of tissues.This field of research has not been exploredby the chemist, and there is ample scope for future developmentsob great importance.Car b oh y dra t es .Any advances which may recently have been made in our know-ledge of the carbohydrates are largely discounted by t.he fact, towhich reference has already been made, that the great pioneer insugar synthesis died during the year. This is not the occasion, evenif space permitted, to make any attempt to1 pay fitting tribute tothe inspiration and instinctive genius which characterised EmilFischer’s best work o’n the’ sugar group, and it is perhaps sufficientto say that, master in more than one branch of organic chemistry,he was, above all, the master of sugar chemistry.He has left behindhim a record in carbohydrate research which many may imitate,but none can excel.In so far as publications reflect the methods of the man, a worthymodel is discernible in Fischer’s papers which well repay carefulstudy even by those who have no special interest in thO sugars. Hehad an extraordinary capacity to formulate schemes of researchwhich wem apparently disconnected, and then finally to marshalthe remits in order, sol that each fitted into its appointed place,making a complete story.It is appropriate that, on this occa+m, a departure should bemade from the customary order in which the carbohydrates havebeen dealt with in recent Annual Reports, and to consider in thefirst place the publications which mark the close of Fischer’s career.It will be recalled that, in 1912, he propounded the view that certaintannins may be regarded as fully esterified glucoses, in whichdigdloyl residues substitute the hydroxyl groups.Despite manyunexpected difficulties and distractions, he continued with character-istic courage lm test his ideas by means of syntheses, and from thetime he succeeded in devising a method f o r the preparation of thepenta-acetyl-m- and pdigalloyl chlorides, it was evident that hehad secured the reagents which would make succees possiblle.He49 C. W. Porter and C. T. Hirst, J. Arner. Chem. Soc., 1919, 41, 1264; A.,i, 558.Df 76 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.lived to see his hopes realised. By acting on glucm with either ofthe above acid chlorides, the colrresponding penta-(penta-acetyl-digalloy1)-glucoses were obtained, and, on further treatment withaqueous sodium hydroxide, the acetyl groups were removed, withthe formation of a penta-digalloyl-glucose :Exclusive of the obvious m- and pisomerim which may be contri-buted by the digalloyl residues, the capacity of the glucose com-ponent to exist in diverse modifications has t o be taken into account,SD that the structure formulated above may be represented byseveral compounds.Fischer found, however, that pnta-(m-digall-oyl)-&glucose resembles natural Chinese tannin closely, and thecorresponding a-compound likewise shows a general agreement,although displaying a different specific rotatioq. I n work of thisdescription, divergency in specific rotations ought not tot weighheavily in judging the success of a synthesis. Scrutiny of some ofFischer's experimental results, such as the effect of acetylation onboth eynthetic and natural tannins, reveals the delicacy of thesecomplexes and their ready tendency t o undergo intramolecularchanges. It would have been in the highest degree surprising ifthe specific roltations of natural and synthetic tannins had COST&sponded exactly, particularly as these values are determined oncolloidal systems. It may thus be taken that a tannin synthesis hasbeen effected, but considering that our views on the structure ofsugars are a t present in a state of flux, it must be admitted thatthe problem lof the constitution of tannin is far from having beensolved.Perusal of the two papers 601 51 dwcribing the resu1t.ereviewed above indicates sufficiently the difficulties encountered, andthe publications deserve careful study in view of the suggestivevariations introduced into ardinary working methods. Incidentally,iil the come of the work a number of minor points have been clearedup, and the patience with which these side-issues have been examinedcommands admiration. For example, the existence of a definiteglucogallin in Chinese rhubarb has always been regarded as indirectevidence in tiupport of the idea that the glucose formed by thehydrolysis of tannin is, not adventitious, but represents a specificcleavage product, yet numerous attempts t o synthesisel this appa-rently simple compound have given most conflicting results.Therecan be no longer any doubt as t o the nature of glucogallin, whichhas been synthwised by the interaction of acetobromogluoose and6o E. Fischer and M. Bergmann, Ber., 1918, 51, 1760; A., i, 87.61 Ibid., 1919, 52, [B], 829; A., i, 278ORGANIC CHEMISTJZY. 77silver triacetylgallate, followed by removal of the acetyl group.This proves that glucogallin is 1 -galloyl-P-glucose, and the com-pound is thus differentiated from p-glucosidogallic acid.52Fischer’s views as to the structure of a typical tannin have beensupported indirectly by the observation 53 that, in the presence ofbo’ric acid the conductivity of tannin isolated from the gall-nut isnotably increased.&!oreover, the exaltation observed is consistentwith the idea that, although there are twenty-five hydroxyl groupsin the molecule, these are distributed in such a manner that onlyten pairs are favourably situated f o r combinatioa with the acid.This is a striking result, but unfortunately it does not throw anylight on the stereochemical condition of the sugar residue, and thesame result would be given by a complex consisting of a monosubsti-tuted glucose with the necessary hydroxyl groups in a single side-chain.It is appropriate that Fischer’s work on tannin shouldbe continued by those with whom he was associated in his earlierinvestigations on this subject. Freudenberg’s latest contributions tothe general problem include an attempt t o identify the unknownhexose present in hamameli-tannin,54 and the isolation from chebulicacid of a new crystalline tannin which apparently possesses the com-paratively simp10 composition of a digalloylglucose. Before leavingthis subject it may be mentioned that, in his closing papers, Fischeradopted the numerical methlod of indicating the position of sub-stituents in sugar derivatives, and the fact may be used as anargument, where other arguments have failed, in favour of theadoption od this measure1 of relief t o the distracted workers 011related topics.It need scarcely be1 pointed out that Fischer’s synthesis appliest o one particular type of tannin only, and that the, nature olf othmclasses olf tannins still remains obscure.A conspicuous example ofthis is furnished in the case oif hemlock tannin. I n the course of anexhaustive experimental study, it has been shown that this complexcontains no sugar chain, and the authors of an important paper,55*confronted as they were with a mass of difficult experimental results,prudently refrain from expressing any opinion as to the detailedconstitution of the compound.52 E. Fischer and M. Bergmann, Ber., 1918, 51, 1804 ; A . , i, 89.J. Brjeseken and W. M. Deems, Proc. K. Akad. Wetensch. Amsterdam.1919, 21, 907; A., i, 412.54 K.Freudenberg, Ber., 1919, 52, [B], 177 ; A., i, 215.b6 R. J. Manning and M. Nierenstein, T., 1919, 115, 66278 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Glucosides.From the tannins it is but a ztep t.0 the consideratio'n of theglucosides proper, and here also it is appropriata that Fischer'slast work should have been crowned with success. Reference wasmade in the Annual Report for 1917 (p. 79) to the variation heintro'duced into glucosidel synthesis, whereby nitrile-glucosides maybe obtained from hydroxy-esters, and, although the experimentaldifficulties encountered are probably more severe than is indicatedin the published papers, there seems no doabt that the methods arewidely applicable and extend to cases where an aliphatic nitrile iscoupled with the glucose residue.To1 take a case in point, aoeto-bromoglucose has been oondensed with ethyl a-hydroxyisobutyrate,and, on treating the product with ammonia, the acetyl groups arelost with the, ultimate production of hydroxybutyramide glucoside :-0 -__-_I ICH,(OAC)*CH(OAC)*CH~[CH*OA~]~*CHB~ + + (CH,),C( OH) *CO,Et1-0-(CHJ 2Q.OCH,(OH)*CH(OH)*CH*[CH*OH],*fHCO*NH,Finally, dehydration of the amide gives the nitrileglucoside, which,in the example given, proveid to1 be linamari11.5~ Although thescheme given above represents the essential steps, considerable varia-tion in procedure is evidently necessary in order t o obtain crystallineproducts, and when the conversion of the acid amide into the nitrileis effected by means of phosphoryl chloride, the product requiresre-amtylation. Obvioasly, the general reaction may be modified soas to produce a wide variety of synthetic glucosides of the cyanu-genetic type, and the inteJresting cases furnished by the glucosideof glycollonitrile 57 and the corresponding celloside 58 give promisethat the chemistry of amygdalin may no'w be attacked synthetically.It is not a severe criticism t o state that the remaining publica-tions on glucosides fall far short of those just reviewed.The heroicefforts of Kiliani to unravel the1 complications of the digitalis glumcsides have not been suspended, although positive results are few innumber, and no more than a passing reference need be made to theti6 E. Fischer and G.Anger, Sitzungsber. K. Akad. Wiss. Berlin, 1918, 203 ;A., 1918, i, 626.57 E. Fischer, Ber., 1919, 52, [B], 197 ; A., i, 256.68 E. Fischer and G. Anger, ibid., 854 ; A., i, 256ORGANICJ CHEMISTRY. 79latest contributions to the subject.59, go. In difficult work of thisdescription it is somewhat disappointing tol find that complicationsare needlessly introduced through the occasional choice of a reagentwhich appears in the higheat degree unsuitable, but the devotionof the investigator is most commendable. Other work which,although only remotely concerned with the sugar group, similarlyarouses feelings of sympathetic admiration is the first step in yetanother attempt to isolate an enzyme in a state 09 analytical purity.The research referred to opens u p a large number of importantquestions, and as the programme contemplated is ambitious, it iswell that i t is in competent hands,m but, as a side-issue which mayyet prove, tot be important, it may be mentioned that the peroxydaseof the horse-radish is associated with a nitrogenous glucoside theproperties of which, so far as they are described, point to a closerelationship with glucosamine.Two years ago attention was directed in the Reports to the, factthat, when silver salicylate reacts with acetobromoglucose, twoisomeric products are formed and the explanati'on then offered astm the underlying mechanism of the reaction has now been con-f i r m d .6 2 It has long been recognised that when the silver saltmethod of esterification is applied.. to a-hydroxy-acids an abnormalresult is obtained in that, to some extent, the alkyl group intro-daoed substitutes the hydroxy-position.The same holds true in thecase of a-amino-acids, and the most obvious interpretation is thatin silver salts of the type mentioned, the metallic atom is attached,not only to the carboxyl, but also t o the, hydroxy- o r amino-poei-tion. According to this view, silver salicylate would be representedasand consequently the glucosides obtained from such a structure bythe actio'n of acetolbromolglucose would display the isomerism shownbelow :/-\*O-Glucose residueand \-/ /-\OH \-/CO-O-Glucose residue CO,HIt is a curious fact that, as a reagent, acetobrolmoglucose is speciallywell adapted for the display of this isomerism, of which several new59 H.Kiliani, Ber., 1918, 51, 1613 ; A., i, 90.6O Ibid., 1919, 52, [B], 200; A., i, 214.61 R. WillstZlitter and A. Stoll, AnmZen, 1918, 416, 21 ; A., 1918, i, 556.6* P. Karrer, C. Niigeli, and R. Weidmann, HeZv. Chim. Acla, 1919, 2,242 ; A., i, 33880 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.examples are now described. As an interesting side-issue of theresearch in question, it may be remarked that the resolution ofinactive mandelic acid was achieved by taking advantage of thedifferent solubilities of the glucmides, but evidently, if this methodis to receive application, due attention must be paid to the forma-tion, on the line6 indicated above, of glucosido-acids.Monosaccharides and their Dem’uatives.Tol turn to the apparently simple subject of the monosaccharidesthere is little of outetanding interest to1 report.As has recentlybeen the case, a number of improved methods of preparation ofsugarsl and related compounds have been described, and amongstthese may be mentioned convenient processes for the isolation ofrhamnae,63 and of gulonolwtone.64 There is generally somethingdefinite about methods of preparatioln, but it is difficult to expressan opinion on the new sugar f l d o s e , which, although claimed tobe an unknown aldohexme, displays a suspicious similarity t o galac-t 0 ~ e . 6 5 It is just possible that the compound may be a variety ofgalactose corresponding with one of the abnormal galactose penta-acetates, but an opinion on this point must in the meantime bewithheld.On fir& inspection, a research on the properties of y-hydroxy-valeraldehyde may seem to have little connexion with the sugargroup, but tthe compound, which has been obtained in an ingenionsmanner,66 is suitable for testing the idea that aldehydic andhydroxyl groups when separated by a chain of three carbon atomsundergo mutual rearrangement to give a butylene oxide.The alde-hyde in question certainly displays most of the reactions of a reduc-ing sugar, and as it gives a ‘‘ methylglucoside,” an additional argu-ment is thus forthcoming in support of the current view of sugarstructure. The critic may find some inconsistencies in the evidence,and it is unfortunate that the: absence of optical activity placeslimitations on the search f o r analogies, but this does not detractfrom the appreciation of the treatment of an interesting subject.Work od a similar nature might with advantage be conducted ona-, &, and 8-hydroxy-aldehydes in vielw of the obscure isomerismof sugars t o which attention has been directed in recent years.I naddition, the physical examination of sugars requires considerable63 E. P . Clark, J . Biol. Chem., 1919,38, 255 ; A., i, 387.64 F. B. La Forge, ibid., 1918,36, 347 ; A., i, 65.6s E. Takahashi, J . Toby0 Chem. Soc., 1919,4Q, 157 ; A., i, 387.e6 B. Helferich, Bet-., 1919,52, [B], 1123; A., i, 386ORGANIC CHEMISTRY. 81expansion, and thus a further study G7 of the mutarotation of glucoeeand fructose is welcome, even admitting that this phenomenon hasalready beeri thoroughly examined.The fact that temperatureaffects the rotation equilibrium of the ketose is not new, but it ishighly significant that, in this special case, mutarotation cannot beregarded as due simply to a change in the position of one hydroxylgroup. This adds to the evidence that fructoee exists in solution inmore than two forms.It is with considerable reluctance that no detailed account isgiven here of Levene's efforts t o advance the difficult chemistry ofthe amino-sugars, but the experimental treatment of the subject issuch that results leading to final conclusions as to configuration are,of necessity, delayed until the full scheme od research is complete.It would thus be premature, and also an injustice t o a carefullyconceived series of researches, t o discuss the intermediate results sofar contributed, but reference should bel madel to the papm whichhave appeared during the year.I n order that the investigationsmay be followed, it should be mentioned that the goal of the workis the allocation, to a definite configuration, of the amino-grouppresent in compounds of the glumsamine t p . The method ofattack is to study the corresponding amic acids, rather than thesugars to which they are rdated, and t o pay particular attentionto' the compounds which form epimeric pairs. The difficulty in pre-paring these hexoeamic acids or their epimerid-68 and the compli-cations involved in the removal of the aminoLgroup by nitrous acid:9can be fully appreciated only by thoae whcm work has led theminto this field.I n the latest publication on this subject 70 a distinctadvance has been made in that the epimeride of glucosamine hasbeen isolated and described. The reactions of the compound arenormal save in two respects. NO monocarboxylic acid has yet beenobtained from it, and, curiously enough, when treated with nitrousacid, no molecular dehydration took place, but saccharic acid wasformed. Nevertheless, the sugar is readily converted into the ana-logue of chitose, and this was isolated in the crystalline condition.Some confusion of ideas seems to exist a5 t o the reasons underlyingthe failure of epichitosamine to display mutarotation, and until thefree sugar has been obtained in u- and P-modificatioins in whichdefinite configurations can be allocated to the reducing groups, it isaltogether premature to delete from consideration a betaine struc-ture for this and analogous compounds.i, 256.67 J.M. Nelson and F. M. Beegle, J . Amer. Chem. SOC., 1919, 41, 659 ; A,,68 P. A. Levene, J . Bid. Chem., 1918,86, 73 ; A., 1918, i, 530.G s Ibid., 89; A,, 1918, i, 532. 'O Ibid., 1919, 39, 69; A., i, 47582 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Disac charides.Recently the contributions under this heading have shown a dis-tinct falling away in number, but the quality of the work describedhas been well maintained. Synthesis by means of enzyme actioncontinues to make progress, and amongst new results may be men-tioned the formation of gentiobiose as one of the products obtainedin a reaction designed to produce glycol glucdsides by the syntheticaction of emulsin.71 I n view of the earlier synthesis of gentiobiosethe result is not surprising, but the auto-condensation of gluoose isnot restricted to' on0 type of coupling, oellobiose having been isolatedas the fourth definite product 6f the synthesis.72 The latter resultassumes a new importance when taken in conjunction with the factthat the chemistry of cellulose is now being attacked by means ofenzyme degradation, so! that the p i t i o n has been reached in which,by oppositely directed enzyme actions, the ascent from glucose andthe dement from cellulose are being studied.If, and where, suchlines of work meet is an interesting speculatioln.The value attached t o enzyme synthesis of disaccharides is great,and its importance in throwing light on the stereochemical condi-tion of the constituent h-exoses is well rmgnised, but, in the mean-time, the inner structure of the disaccharides must be elucidatedby methods more familiar to the organic chemist. The structuralstudy obf the disaccharides which depends on methylation, followedby identification of the hydrolysis products, has already given im-proved formule for sucrose and lactose. Results equally diagnostichave now been obtained with maltose. The fact that in this casethe sequence of reactions outlined above gives tetramethyl glucoseas one product has now been confirmed73 under conditions whichadmit of no dubiety of interpretation, but the research was compli-cated by an unexpected degradation encountered in the preparationof methylmaltoside, and thus the structure of the reducing glucosecomponent i n maltose remained undecided.This, however, has beenaccomplished by varying the experimental procedure.74 Startingfrom the free sugar, methylmaltoside was produced by the carerullyregulated action of methyl sulphate and sodium hydroxide. Thereaftar, the same reagents were effective in completing the alkylation,so that the final product was a heptamethyl methylmaltolside. Onhydrolysis, the substituted hexoses isolated proved to be tetramethylglucose and the form of trimethyl glucose which has been obtained11 E.Bourquelot and M. Bride], Compt. rend. !919,168, 263 ; A,, i, 137.'* J. C. Irvine andwJ. S. Dick, T., 1919, 115, 693. '' W. N. Haworth and (Miss) G. C. Leitch, {bid., 809.Ibid., 1016 ; A., i, 361ORBANI0 UHEMISTRY. 83from methylgluooside. Identification of these methylated sugarsaffords an experimental verification of Fischer's formula for maltose,which is evidently in good agreement with all the properties of thesugar.Polysaccharides.Whilst research on cellulose and its derivatives continue8 to beexceedingly active, nothing of a very definite nature has been noteddealing with the primary constitution of the most important of allpolysaccharides. Our ideas regarding thg chemical constitution ofcellulose cannot be dissociated from the physical nature of the com-plex and, a t the prment time, it is well to preserve an open mind onthe general question.Various reviews of past work have been con-tributed during the year by well-known investigators in this field,but these need not be discussed, and reference may be confined toone experimental result which, although nolt directly connected withcellulose, has a certain significance. It will be remembered thatPictet obtained Z-glucosan by the dry distillation of cellulose orstarch under diminished pressure, and that he put forward the ideathat these polysaccharides arise from the polymerisation of this parti-cular anhydroglucose along different lines. It is now claimed 75 that,in part, this expectation has been verified as, under the influence ofplatinum black, giucosan is transformed into an amorphous com-pound, (C6H1005)4, displaying the properties of a dextrin and inwhich optical activity is retained. 'The further expansion of thissubject will be watched with great interest,.and it may be noted inpassing that the chemistry of starch is at present attracting numerousworkers.Although in general the results obtained are beyond thesoope of this section of the Report, brief reference may be madet o the vigorous discussion which has centred round the claim thatformaldehyde effects a diastatic degradation of starch. The discus-sion has, in fact, expanded out of all proportion to1 the inherentvalue of the loriginal experimental evidence, but the controversynow appear3 t o be ended.It has been shown, for example;76 thatthe failure of starch to give the iodine reaction after treatment withformaldehyde cannot be accepted as valid evidence of degradation.It has even been found that unchanged starch may bfe recoveredquantitatively after treatment with formaldehyde.77 This is damag-ing evidence, and the idea that the formation of a loose additivecompound of formaldehyde and starch would account for all the75 A. Picfet, Hdv. C h h . Acta, 1918, I, 226; A., 1918, i, 527.v6 M. Jacoby, Ber., 1919, 52, [B], 658; A., i, 311.77 W. von Kaufmann and A. Lewite, iW., 616 : A., i, 31284 ANNUAL REPORTS ON THE PROURElSS OF CHEMISTRY.result& described by Woker is supporbd from other quarter~.~8* 79 Atthe same time, bio-chemists seem reluctant to abandon the idea thata parallel may be drawn between the action of diastase and that offormaldehyde, but the arguments produced are not convincing, andthe subject may be regarded as clwed.Nitrogen Compo.u72ds.So long aa discussion is restricted to substances which are essen-tially open chains, the publications (of the past year on aliphaticnitrogen compounds have been less numerous and less complicatedthan usual.Many of the papers describe new or improved methodsof preparing common reagents, and these may be considered in thefirst place. As is but natural, much attention has been given tothe question of utilising, in a profitable manner, the large quantitiesof organic shell-fillings which have recently been aocumulated, and,in the case of chloropicrin, it has been shown80 that the compoundcan be economically employed for the production of methylamine.When reduced by means of iron and hydrochloric acid, exceedinglygood yields of the amine salt are obtained, and, as is usually thecase in this particular type of reduction, it is possible to restrict theam'ount of acid to1 about 3 per cent.of the theoretical quantity. I nview of the applications of methylamine it is an important p i n tthat, under favourable conditions, only a small proportion ofammonium chloride is furmed, and it would appear that the con-centration of acid used is an essential factor in controlling thecourse of the reduction. An expIanation of thia result is found inanother research,81 where it is shown that chlloropicrin is graduallyresolved a t the boiling point into carbonyl chloride and nitrosylchloride :CCl,*NO, --+ COCl, + NOCl.It would thus appear that the formation of methylamine by reduc-tion is due to reaction of chloropicrin as such, whereas ammonia isto be regarded as derived from the decomposition products.It is perhaps doubtful if the element of danger involved in thepreparation and use of chloropicrin will permit of the applicationaf such a method on the large scale.It may be remarked that thereaction between ammonium chloride and formaldehyde, which wasrecommended by Werner as a convenient source vf methylamine,78 H. Sallinger, Ber., 1919, 52, [B], 651 ; A., i, 263.7O J. Wohlgemuth, Biochem.Zeibch., 1919, M, 213 ; A,, i, 361.80 P. F. Frankland, F. Challenger, and N. A. Nicholls, T., 1919, 115, 159.J. A. Gardner and F. W. Fox, iM., 1188ORGANIC CHEMISTRY. 86;gives g o d yields of the base, and Dome modifications of the workingdetails have been contributed in the course of the year.82Much ingenuity has also been expended on the development ofprocesses for separating primary, secondary, and tertiary amines,but the references for the most part are in the patent literature. Asan example, it may be stated that when a mixture of amines istreated with ethyl chloroformate, the tertiary form remains un-changed while the primary and secondary bases are regenerated byhydrolysis.83 Carbonyl chloride may also be employed tol separatesecondary and tertiary amines,a and in addition considerable sue-cess has attended the attempt to develop a practical method of wp-rating amines by partial neutraIisation with hydrochloric acid.85Before leaving the subject of amines mention should be made of asubstantial improvement in the method for preparing diawton-amine,86 in which the action of ammonia on acetone is greatly facili-tated by the addition of calcium chloride.This variation consti-tutes a distinct advantage, and its adoption not only gives enhancedyields, but reduces the recolvery of unaltered acetone and alcohmolto a minimum.Passing to a related subject, a solmewhat unexpected property ofacetobromoamide is described by Wohl,87 who has shown that thecompound can function as a brominating agent.The reactionseems to be applicable to' a large variety osf cases, and the conversionof phenol into y-bromophenol may be quoted as a sufficiently strik-ing example of its elfficacy. With regard to the mechanism of thechange, it would appear that a direct interchange of hydrogen andbromine occurs between the two reacting molecules, and, if thisproves to be the case, the prospect is opened out of conductingbrominations without the formation of hydrogen bromide as aninevitable and disturbing by-product. Obviously, this would inmaay cases be a highly desirable condition, particularly whenunsaturated or optically active compounds are being manipulated.It may be remarked that, for the time being, research on opticallyactive amino-compounds is in a state of suspension, but there is adistinct revival in the study of general synthetical reactions withoutreference t o stereochemical problems.Most of these investigationshave been oonducted on standard lines, and are extensions oif former82 H. I. Jones and R. Wheatley, J . Amer. Chem. SOC., 1918, 40, 1411 ; A.,1918, i, 527.a8 W. Rintoul, J. Thomas, and Nobel's Explosives Co., Ltd., Brit. Pat.127740 ; A,, i, 388.84 Ibid., 128372 ; A,, i, 433.85 E. A. Werner, T., 1919,115, 1010.87 A. Wohl, Ber., 1919, 52, [B], 51 ; A., i, 198.88 A. E. Everest, ibid., 58886 ANNUAL REPORTS ON TEIE PROGRESS OF CHEMISTRY.work, so that a t present de'tailed reference is unnecessary, as nop i n k of fundamental theoretical importance appear to be involved.Structural questions, such as the distribution of the nitrogen valen-ciea and the isomerism of the quaternary ammonium salts, still con-tinue t o attract workers, but here also is a lack of novelty, althoughmention may be made in passing of the abnormal salts isolated byMredekind in his studies of compounds clontaining two) asymmetricnitrogen atoms of unlike asymmetry. On the other hand, distinctprogress has bmeen made in the constitutional problems presented bythe carbamides, and some of the outstanding results are now dis-cuss&.It is frequently the case that intimate study of a reaction, gener-ally regarded as simple, reveals many unexpected complications, andmuch of the recent research on urea furniihee examples of this.I nparticular, the customary method of expressing the formatiotn ofcarbamide from carbonyl chloride, can no longer be claimed to give afaithful representation of what occurs, as the reaction appears tobe based oa the union of ammonia and cyanic acid in the keto-imino-f orm.89 I n addition, the latest contributions to the' study ofcarbamides not only lend strong support to the views expressedby Werner as to the constitutional changes undergone by these com-pounds, but. also1 describe new working methods which are of value.I n the case of a monosubstituted urea, evidence has been accumu-lated to show that the equilibrium:NH,*CO*NHR OH*C(:NH)*NHRis determined by the electrochemical chaxacter of the group R andthe co-existence of these forms is oonfirmed, in the particularexample of monomethylurea, by a quantitative study of the reactionwith nitrous acid.This can be dissected into two parts, in thesecond of which nitrosomethylurea is suddenly formed 90 af&r theevolution of nitrogen has ceased, and the subsequent conve:sion ofthe nitroso-colmpound into diazomethane by the agency of sodiumethoxide has disclosed the fact that alcohol may be employed as asolvent in the latter reaction. Contrary t o expectation, diazo-methane reacts with alcohol extremely slotwly, i f a t all, and it isthus possible to effect methylation of a hydroxy-compound by dis-solving the latter in an alcoholic solution of nitrosomethylurea andthen adding the calculated quantity ,of sodium alkyloxide.This is adistinct advance, on the customary method of dissolving, oh suspend-ing, a compound in an ethereal solution olf the methylating reagent,88 E. Wedekind and T. Goost, Ber., 1919, 52, [B], 446; A., i, 286.89 E. A. Werner, T., 1918, 113, 694.Ibid., 1919,115, 1093ORGANIC CHEMISTRY. 87and advantage has been taken of this useful variation to verify thestatement that urea is not affected by diazomethane.91 Even whendissolved in alcohol and kept in contact with the reagent for manyhours the urea r'emained unchanged, and this result, which is inhasmony with the view that urea is t o be regarded as possmsingthe cyclic structure in neutral solution, is in sharp contrast to thatobtained with thiourea under parallel conditions.In this ease, amethyl group becomes attached to sulphur with the formation of thehomologue, SMe*C(:NH)*NH,, thus adding to the evidence thatthiourea exists in neutral solution as an equilibrated mixture of :A survey of the literature 'on the use of diazomethane reveals asurprising number of cases where this modified procedure wouldhave proved an advantage, and it is well to direct attention to themethod.I n drawing up this Report the original papers have been con-sulted wherever possible, but before these came to hand copiousnotes had in many cases been prepared from the abstracts publishedby the Society. The writer is thus in a position to appreciate theunfailing accuracy of the synopses and, as on a previoas occasion,cannot close the Report without exprwing his indebtedness to theabetractors.JAMES COLQUHOUN IRVINE.PART II.-HOMOCYCLIC DIVISION.2% eoretical.IT is extremely difficult to determine the origin and authorship ofcertain theories in modern organio chemistry, and a reporter mayperhaps best note the trend of speculation and emphasise any pointson which there seems to be an almost general agreement.Duringthe past year several papers have appeared dealing inter alia withthe problem of orientation, and the connecting thread is un-doubtedly the theory that atoms and groups direct the positionin the molecule taken up by entering substituents or, alternatively,determine the constitution of an additive product as the result ofa certain effect on alternate atoms in a chain.H. J. Prim1 dis-O1 E. A. Werner, T., 1919,115, 1168.1 Chem. Weelcblad, 1918,15, 671 ; A., i, 7188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tinguishea between link-energy and atom-energy and the mannerin which the alternating effect is assumed to occur may begathered from the following quotationz: “The entry of anysubstituent X into the benzene ring must cause a change inthe relation between atom-energy and link-energy, both inthe substituent and in the nucleus. Two cases may arise.In the first, in which the link-energy between X and C,, themrbm atom to which X becomes attached, is greater than thatbetween C, and the hydrogen atom displaced; the atom-energy ofC, is therefore reduced, and to restore this as far as possible, thelink-energy between C, and its neighbours, C, and C3, is reduced,with the consequence that the link-energy between C, and C, andbetween C3 and C, is increased (C, and C, b&g the neighboursof C2 and C, remote from C,), and that between C, and C, andC, and C6 is diminished; C,, therefore, by the diminution of itslink-energy, receives an increase of atom-energy, and is thereforerendered more reactive.The effect of introducing X, therefore, isto make the para-carbon atom more reactive. In the second case,in which the link-energy between C, and the substituent is lessthan between C, and hydrogen, the redistribution of energy oitaesan increase in the atom energy of C, and C,, that is, of the carbonatoms in the meta-position.”D. Vorliinder 3 employs a very similar conception, that of variableinternal molecular strain, but uses + and - signs to illustrate thealternating effects of atoms and groups.He definitely states, how-ever, that his views are not based on valency theories, The condi-tion of strain supposed to exist in nitrobenzene (I) and aniline (11)is illustrated below, and it is assumed that reachions will occur in+- - ++a INH,+H ), H+ \, + \/such a manner as to diminish the link tensions so that the m-posi-tion will be attacked in nitrobenzene and the o- and p-positions inaniline. The whole theory resembles very much those of Flur-scheim and of Thiele. The alternate + - labelling of atoms in itPrim, b c . cit. Ber., 1919, 52, [B], 263 ; A., i, 319ORGANIC CHEMISTRY. 89- - -straight chain starting with those of recognised polarity (Cl, Br, I,0, N, S, Na, H) has also been applied by A.Lapworth 4 a4 a meansof explaining, and in certain cases of predicting, the direction ofchemical changes, such as substitution and addition. Lapworthsviews have an electrical basis, and his symbols indioate all the anionsand cations which the molecule could conceivably yield. Actual ion-isation is neither assumed nor excluded. I f as the result of thismethod of expression an unsaturated centre bears the + sign it willattract the - portion of the molecule added, and vice versa. Also,if a + atom acquires additional + character it becomes more reac-tive, and similarly - atoms enter into reactions more readily iftheir - character is enhanced as the result of the influence of thepolar atom from which the labelling commences.Exactly similarresults are obtained by the application of the present writer’s 5 viewson conjugation of partial valencies, primary and secondary. Forpractical purposes Lapworth‘s notation is the most convenient, anda few examples may be cited.+ + - - -+-I- - - ++ + Additioit of HRr to Propylene, H3C-GH===CH, + - + - + - + - + - + -The effect of all the hydrogen atoms is here carried through tothe unsaturated carbon atoms, and it is seen that the central atomis oveIwhelmingly positive, and the result of the reaction is accord-ingly the produotion of &opropyl bromide.Addition of Hydrogen Bromide to Vinyl Bromide andA ZZyl Byomide.- + -CH,=CHBrH--Br + -- + - +CH2=CH-C!H2BrRr--H- t-Addition of Hydrogen Cymide t o Unsaturated Ketones.+ - -CH=CH-&O-CN--B - +Brit.ASSOC., Bournemouth meeting, Sect, B. Ibid90 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Substitution in the Aromat,ic Series.- + -OH+H\ /\ /H+\/ + vNO,If H-I n this connexion mention may be made of a most interestingobservation by W. H. Gough and J. F. Thorpe,6 who find thatalthough 0- and p-xylylene dibromides react with potassium cyanidein alccholic solution with the formation of xylylene dioyanides andthe intermediate bromo-cyanides cannot be isolated, it is an easymatter to obtain o-bromo-m-tolylacetonitrile (I) by the interactionof m-xylylene dibromide and potassium cyanide.I n accordance withthe + - rule, the three xylylene dibromides and intermediatebromucyanides would be formulated as shown below, and it is atonce evident that, whilst the introduction of the first cyan+groupenhances the reactivity of the remaining bromine atom in the 0- andpseries, i t diminishes it in the m-compound:f- +f- CH,&- I + -/\/ - \-\ -k /\/A\/F H2Brf-/ /\ \/ /CH,Br fI tl- \ - / I -I+ I It/vI I- i - CH,Br + -I- + CH2Brf -* The arrows: indicate:this cme the nitrogen.,CH,*CN C H , ~ N//\\/ I /\ / + \\ - /\/I +I-\/ I :I I\ + /I CH,Br - +UH,Brf - (1.1the atom from which the labelling commences, inThis work, taken a t random to illustrate the application of a6 T., 1919,115, 1155ORGANIC CHEMISTRY.91theory, is in itself a matter of considerable importance, and furtherdevelopments of our knowledge of half-stage reactions in symmetri-cal ccrnpounds will be welcomed. Most synthetical chemists havehad sad experiences of poor yields obtained in such processes.Molecular Rearrangement.L. Claiseni has continued the investigation of the remarkabletransformation o l substituted phenyl allyl ethers into allylphenols.The exhaustive allylation of phenol is effected in accordance withthe following scheme :No trace of 4-allylphenol or 2 : 4-diallylphenol is produced in thetransformation of phenyl allyl ether and o-allylphenyl allyl etherrespectively. 2 : 4-Diallylphenol is, however, obtained by eliminationof the carboxyl group from the product of complete allylation ofsalicylic acid.A similar device has resulted in a synthesis ofeugenol (IV). Methyl guaiacolcarboxylate (I) is converted into itaallyl ether (11) by boiling with allyl bromide, potassium carbonate,and a little potassium iodide in methyl ethyl ketone solution. TheOH O*C3H, OHM~O/)CO,M~ MeOf",CO,Me MeO/\lCO,H(1.1 (11.1 (In.)Me01 JCH,*CH:CH2(N.1\/ L C3H5 LHO/\\/' L. Claisen, 0. Eisleb, and F. Kremers, Annulen, 1919,418, 69 ; A., i, 26692 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.acid obtained on hydrolysis of the methyl ester yields o-eugenol andcarbon dioxide on baing heated, but the ester itself is very readilytransformed a t 230--240° into the methyl ester of 6-hydroxy-5-methoxy-3-allglbenzoic acid (111).The latter yields eugenol whentreated with dimethylaniline a t 1 60° :Pinncone-Pinacolin Transformation.The dehydrating action of zinc chloride converts l-methyl-1 -a-hydroxyethylcyclopentane (I) into 1 : 2-dimethyl-A~-cycZohexene(11), and the reaction is one of the smoothest known enlargementsof the cyclopentane ring 8 :CH,A considerable number of ccglycols containing aryl groups havebeen synthesised,g and their dehydration products examined.Normal results were observed.The Action of Benzilic Acid on Arylthiocarbimides.Becker and Bistrzycki 10 found that the addition of benzilic acidto phenylthiocarbimide did not yield the expected O-ester,NHPh*CS*O*CPh*COzH, but instead N-phenyl-S-benzhydrylthio-carbam a,tea- car box ylic Theyassumed at the time bhat the O-ester was the first product, and thatthis changed over to the substance actually obtained, *CS*O* becom-ing *CO*S*.In the case of benzilic acid the intermediate productcould not be isolated, but the assumption made has now been justi-fied by the study 11 of the addition of benzhydrol to phenylthiocarb-imide. The reaction is carried out in xylene solution with thesodium derivative of benzhydrol, and results in the formation of0 -benzhydryl N-phenylthiocarbamate, . NHPh*CS*O*CHPh,. Thetransformation to the S-ester, NHPh*CO*S*CHP&, may be accom-plished by boiling with acetic acid or by heating a t 130-135O or bya u d , NHP he C 0 S CP hz C 0,H.H. Meerwein, Annalen, 1918,417, 255 ; A., i, 162.A.Or6khoffYBuZl. SOC. chim., 1919, [iv], 25, 108, 111, 115, 174, 179, 182,186; A., i, 205, 206, 271, 272.lo Ber., 1914, 47, 3149 ; A,, 1914, i, 245.l1 A. Bettschart and A. Bistrzycki, HeZv. Chim. Acta, 1919, 2, 118; A , ,i, 207ORGANIC CHEMISTRY. 93cold hydrochloric acid. The change by acids is regarded as beingdue to hydrolysis with the formation of benzhydrol, which in theform of an ester adds on to the *CS* group. The intermediate stepmay then be written:/S*CHPb2 ...NTIPh*C/ -0,Ac ,‘0- CHPh,\ ..and the reaction is completed as indicated by the dotted line, benz-hydryl acetate being eliminated. This hypothesis is strongly sup-ported by the observation that the transformation may be effectedby heating the O-ester with a little benzhydryl acetate or bromide intoluene.NHPh-CS-O*CH,Ph,is stable towards boiling glacial acetic acid.The reaction between chlorotriphenylmethane and diarylaminesproceeds normally only in the case of p-tetramethyldiaminodi-phenylamine.In other cases investigated 12 there is molecularrearrangement,, and, for example, chlorotriphenylmethane anddiphenylamine yield p-anilinotetraphenylmethane (11). !The normalproduct (I) is obtained from tetraphenylhydrazine and triphenyl-methyl. It is converted into p-anilinotetraphenylmethane by heatingwith diphenylamine hydrochloride in benzene solution :CPb ,*NPh, CPh3*C,H,*NHPh(1.1 (11.)It is interesting that the benzyl derivative,New Reactions.A simple synthesis of phloroglucinol has been described.lSMalonyl chloride and acetone in the presence of calcium carbonateyield phloroglucinol and diacetoacetyl chloride,CH,*CO* CE€2*CO*CH2.COc1,which can be changed into the trihydric phenol by boiling water inthe presence of calcium carbonate.P-Resorcylaldehyde and 2 : 4 : 6-trihydroxybenzaldehyde have beenobtained 14 by an application of Hoesch’s synthesis. Hydrogenchloride is passed into an ethereal solution of resorcinol (or phloro-glucinol) and cyanogen bromide in the presence of zinc chloride.H. Wieland, B.Dolgow, and T. J. Albert, Ber., 1919, 52, [B], 893 ; A . ,i, 324.l3 T. Komninos, Compt. rend., 1918, 16’7, 781 ; Bull. SOC. chim., 1918, [iv],20, 449 ; A., i, 6.l4 P. Karrer, H e b . Chirn. Actu, 1919, 2, 89 ; A., i, 16094 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A crystalline intermediate product containing chlorine but notbromine is collected and boiled with water.The reactions involvedappear to be:(i) CBrN + HC1 = CHBrtNCl; (ii) CHBr:NCl + C,H,(OH),=C6H3(OH),*CH:NC1 + HBr ; (iii) C6H,(OH),*CH:NC1 xrC,H,( OH), CH 0.Acetyl chloride and styrene in the presence of stannic chloridegive P-chloro-P-phenylethyl methyl ketone, which in its t'urn yieldsstyryl methyl ketone on treatment with diethylaniline.15In the course of an investigation 16 of the condensation productsof o-phthalaldehyde with dimethylaniline both normal and abnormalproducts were isolated. With excess of dimethylaniline and zincchloride the leuco-base of o-phthalaldehyde green,ctiH*[c.H (%H4 'NMez)z]z 2was obtained, whilst if the dimethylaniline was restricted to twomoleoular proportions o-aldehydoleucomalachite green was the pro-duct. When, however, o-phthalaldehyde and dimethylaniline werecondensed on the water-bath by means of concentrated hydrochloricacid a red base, C2,H,,0,N, was isolated, and convincing evidenceis available that this substance must be regarded as 2-o-aldehydo-phenyl-3-p-dimethylaminophenylindone :c a o *C,H,--G* 70NMe,*C6H4-C*C6H4The AT-alkyloximes have frequently been formulated as cyclicethers, thus, R-CH-NR, but just as the azoxy-compounds are now\/0regarded as containing the group *N:NO-, so the substances underconsideration may have the constitution CHR:NO*R.H.Staudinger and K.Miescher17 adopt this view, and also thename ' nitrone ' first suggested by Pfeiffer.l8 It is now found that'keto' nitrones, CR,:NO*R, are readily obtained by the action ofaliphatic diazo-compounds on nitroso-compounds, possibly in accord-ance with the scheme:NR*NO+CR,<j.J --+ NR<'--R -+ NR<? CR,:NR:O.The presence of two double linkings in the nitrones is renderedCR,*N CR,16 G. Langlois, Compt. rend., 1919, 168, 1052 ; A., i, 332.l6 E. Weitz, Annalen, 1919, 418, 1 ; A., i, 290.17 Helv. Chim. Acla, 1919, 2, 554 ; A., i, 584.lY Anncclen, 1916,411, 72 ; A., 1916, i, 327ORGANIC CHEMISTRY. 95tolerably certain by the fact that they combine with diphenyl-keten in two stages, thus:-0-CPb,:NPh:O + CPh,:CO + CPh2:NPh<Cph2>C0 (I)Diphenyl-N-phenylnitrone (from nitrosobenzene and diphenyl-diazomethane) is reduced by iron powder to benzophenoneanil, andoxidised by ozone to benzophenone and nitrobenzene. Boiling dilutesulphuric acid hyclrolyses it t o benzophenone and p-aminophenol.By heating the compound (I) a t 190° tetraphenyl-N-phenylnitrene,CPh,:NPh:CP&, is obtained, and constitutes the first example ofan entirely new type of substrance derived from the hypothetical' nitrene,' CH,:NH:CII,. This compound crystallises in pale yellowprisms melting a t 137'. On reduction with aluminium amalgam ityields dibenzhydrylaniline, NPh(CHPh,),, which was synthesised forcomparison.Many other nitrones and a few nitrenes have beenprepared and their properties examined in detail.Sub s t it u t ion and Orient at ion.It is not possible to notice the greater part of the systematicwork falling under this head, but it should be stated that therehas been considerable activity in this field, and many gaps havebeen usefully filled.On iodination 19 with the required quantity of iodine and nitricacid , iodobenzene gives pdi-iodobenzene ; chlorobenzene givespchloroiodobenzene, and bromobenzene, pbromoiodobenzene.pChloro- and pbrorno-toluenes give pchloro- and p-bromo-benzoicacids respectively, the methyl groups being oxidised to carboxyland no entry of iodine taking place.From benzoic acid, miodo-benzoic acid was obtained, and from o-phthalic acid, 4-iOdO-O-phthalic acid. Phenylacetic acid gives p-iodophenylacetic aoid andcinnamic acid, p-iodocinnamio acid.This method had previously been employed by G .M. Robinsonin the iodinat.ion of 0- and pnitzoanisole.m e interesting case of the nitration of benzotrichloride has beeninvestigated both by Vorlander 19@ and by E. Spreckels.20 Inthe very careful work of the latter precautions were taken to avoidI@ R. L. Datta and N. R. Chatterjee, J . Amer. Chem. SOC., 1919, 41, 292;A., i, 153.2o Ber., 1919, 52, [B], 315 ; A., i, 263.19a LOC. C i t 96 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hydrolysis of the trichloride, and nitrobenzotrichlorides were ob-tained. Nitrogen pentoxide in carbon tetrachloride a t - loo yieldsits main product m-nitrobenzotrichloride with about 20 per cent. ofthe p-derivative and some ortho.Benzoic acid yields a far higherproportion of m-nitrobenzoic acid.The m-directive character of the ammonium salt group is alreadywell recognised, but D. Vorliinder and E. Siebert 21 have made adefinite contribution to the subject in demonstrating that onbrominating phenyltrimethylarnmonium bromide the m-bromo-deriv-ative is obtained, and also that m-nitrophenyltrimethylammoniumnitrate results from the nitration of phenyltrimethylammoniumnitrate. Neither reaction proceeds a t all readily, in harmony withthe usual experience of m-substitutions.The relations of the nitro-derivatives of diphenylarnine have beenelucidated,22 and the following scheme23 illustrates the course of thereaction between nitric acid, nitrous acid, and diphenylamine a t theordinary temperature, and a t low concentrations of the interactingcompounds :DiphenylamineJ.DiphenylnitrosoamineIJ. J.4-Nitrodiphenylnitrosoamine (2-Nitrodiphenylnitrosoamine)4-Nitrodiphenylamine (2-Nitrodiphenylamine)! I 1 I + J .J . J.4 : 10-Dinitrodiphenyl- 2 : 10-Dinitrodiphenyl- (2 : 8-Dinitrodiphenyl-nitrosoamine nitrosoamine ni trosoamine)4 : 10-Dinitrodiphenyl- 2 : 10-Dinitrodiphenyl- 2 : 8-Dinitrodiphenyl-amine amine amineI + I IJ.I + J.2 : 4 : 8-Trinitrodiphenylamine (2 : 4 : 10-Trinitrodiphenylamine)I I I I2 : 4 : 8 : 10-Tetranitrodiphenylamine. J. . +The compounds shoswn in brackets have not been isolated, but21 Ber., 1919, 52, [B], 283 ; A., i, 320.22 H. Ryan and T. Glover, Proc.Roy. Irish Acad., 1918, 34, [B], 97 ; A.,13 H. Ryan and P. Ryan, ibid., 1919, 34, 212 ; A., i, 482.are probably present in some of the fradions obtained.i, 13ORGANIC CHEMISTRY. 97LTatural Products.Guuiayefic A cid.-The communication 24 under review coiistitutesa notable advance in our knowledge of the constituents of resins.On dry distillation of guaiacum resin, two substances of unknownconstitution are produced, namely, guaiene and pyroguacin orhydroxymethoxyguaiene. Guaiene is now proved to be 2 : 3-dimethylnaphthalene, which was synt-hesised by a method thatleaves no doubt as to its constitution. P-Phenylisopropyl alcoholwas converted into the corresponding bromide and then into ,ethylP-phenylisopropylmalonate, CH,Ph*CHMe*CH(CO,Et),, by con-densation with sodiomalonic ester.This was methylated by theusual method, and the dibasic acid obtained by hydrolysis furnishedy-phenyl-aP-dimethylbutyric acid, CH,Ph*CHMe*CHMe*CO,H, onbeing heated a t 170-190°. Kipping's method was then requisi-tioned in order to close t*he naphthalene1 ring, the acid chloride ofthe above acid being treated with aluminium chloride so. as t oobtain l-keto-2 : 3-dimethyl-1 : 2 : 3 : 4-tetrahydronaphthalene (I).(11.; (111.)The corresponding alcohol, obtained on reduction, loses watel a t200°, yielding the dihydronaphthalene derivative (11), and thedibromidei of this is convkrted into 2 : 3-dimethylnaphthalena bythe action of alcoholic potassium hydroxide. Guaiene was a t firstthought to be 1 : 2-dimethylnaphthalene, and the latt4er substancewas also synthesised by somewhat similar methods.The inter-mediate was, in this case, the ketone (111), and the second methylgroup was introduced by the action of magnesium methyl iodide.Guaiaretic acid, the isolatioii of which from the resin ipdescribed, has the formula C,,,H%O,, is optically active andunsaturated. Its dimethyl ether, C,,H,,(OMe),, may be reducedunder vigorous conditions to a dihydro-derivative, isolatedboth in an actlivei and inactive form. The latter is thoughtio be a nzeso-modification, and the conclusioii is drawn thatthe molecule of the hydro-derivative contains two asymmetriccarbon atoms symmetrically disposed. Guaiaretic acid methylether yields verat<ric acid on oxidation with potassium per-24 C : .Schroeter, T,. Lichtenstutit, anti 13. Trineii, B e y . , 1918, 51, 1587 ; A . ,i , 84.REP.-VOT,. XVI. 98 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.manganate, and at the same time a portion of the substance isactually reduced t o hydroguaiaretic acid methyl ether. The ex-planation of this quite remarkable transformation is found in theaction of Hubl’s iodine solution on guaiaretic acid methyl ether.whereby i-hydroguaiaretic acid methyl ether and dehydroguaiareticacid methyl ether, C,,H,,O,, are obtained in the proportion of 1 : 2.It is probable, therefore, that, in the permanganate oxidatioii aportion of the guaiaretic acid methyl ether is reduced a t the expenseof another portion, and that hydroguaiaretic acid methyl ether isisolated on account of its great stability towards oxidising agents.i-Hydroguaiaretic acid methyl ether yields dibromo- and dinitro-derivatives, and the latter on reduction is changed into a diamine,which could not be resolved with the aid of d-tartaric acid.Guaiaretic acid methyl ether must, in view of thel above andother evidence, have the constitutionC,H3(OMe),*CH:CMe*CHMe*CH,*C,H,(OMe),,and guaiaretic acid is thus clearly related t o eugenol.Capsaickn.-The pungent principle of cayenne pepper is a snb-stance of general interest on account of its remarkable physiologicalproperties. A great step forward has been made in regard to theelucidation of its chemistry, and, indeed, prior t o the investigationsof E.K.Nelson 25 and of A. Lapworth and F. A. Royle,2G nothingwas known beyond t-he most elementary details. The hydrolysisof capsaiciii, C,,H,,O,N, by means of methyl-alcoholic hydrochloricacid yields 4-hydroxy-3-methoxybenzylamine (I), prepared for coin-M~O’)CH,-NH,H 01 \/parisoii by the reduction of vanillinoxime. The acid fragment isbest obtained by the use of 25 per cent. sodium hydroxide at 180O.It is found to be a new decenoic acid, C,,H,,O,, yielding by reduc-tion a decoic acid not identical with 12-decoic acid from coconut oil.Nelson therefore concludes that capsaicin is an amide of the consti-tution 11.Lapworth and Royle, who made a careful study of the isolationand properties of capsaiciii, obtained veratric acid by the oxidationof capsaicin methyl ether.Further, the vigorous reduction ofcapsaicin by means of sodium and alcohol was found to yieldammonia and a fatty alcohol boiling a t 216--217O, and convertiblez6 J . Amer. Chem. SOC., 1919, 41, 1115 ; A . , i, 543.26 T., 1919, 115, 1109ORGANIC CHEMISTRY. 99by oxidation into n-nonoic acid; also the action of inorganic acidchlorides on capsaicin gave a nitrile, which was changed byhydrogen peroxide and dilute sodium hydroxide at 40° into anainide melting a t 98-100°, which is the melting point of thesrnide of n-nonoic acid. There is, therefore, still some doubtas to the nature of the fatty chain and its mode of attachment tothe vanillylaminel moleculel. Lapworth and Royle originally sug-gested a dihydro-oxazole constitution, and, in a note attached totheir communication, express the1 opinion that this possibility is notwholly excluded as the result of Nelson's work on the hydrolysisof capsaicin.A somewhat allied topic is the pungency of synthetic compoundsrelated to zingerone, and this has been investigated and certaingeneralisations have been made .27 o-Hydroxystyryl methyl ketonewas found t o be exceptionally pungent.Tropic A cid and Truzillic ,4 cids.-Although not strictly naturalproducts, it is convenient t o mention at this stage that much atten-tion has been paid to these and related subjects during the pastyear.The preparation of tropic acid has been simplified,2g and themethod regarded as most economical is the following. Acetophen-one was converted into atrolactinic acid by the cyanohydrin method,and the latter, by distillation under diminished pressure, gaveatropic acid, which was transformed into P-chlorohydratropic acidby the' action of hydrogen chloride in ethereal solution : this, inturn, was hydrolysecl by aqueous sodium carbonate, and tropic acidobtained.Tropic acid has been resolved by 13.King 29 and also by McKenzieand wit'h almost identical results. The isoatropicacids (a and @) are obtained by heating atrolactinic acid in anatmosphere of carbon dioxide. Concentrated alkalis convert thea-acid into the @-acid, and it is therefore probable that theisomerism of these dimeric atropic acids is stereochemical.Adequate arguments have been put forward31 in favour of theview that the acids have the formula I, and are cis-trans-isomerides.2.7 (Mrs.) L.K. Pearson, Pharrn. J., 1919, 103, 78 ; A., i, 489.?* A. McKenzie and J. K. Wood, T., 1919, 115, 828.29 Ibid., 476.31 L. Smith, Lunds. Univ. Awskr., 1919, [ii], 14, 3 ; A., i, 486.E 230 L O C . cit100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The truxillic acids (a and P ) may also be stereoisomerides havingbhe formula 11, since H. S t ~ b b e ~ ~ has shown that a-truxillic acidP h CO,H\/ cCyHPh*QH* CO,HC H Ph CH C0,Hyields truxone by the action of sulphuric acid only by virtue of aninitial depolymerisation. The absorption curves of a- andP-truxillic acids exhibit close similarity. Stobbe considers thattruxone is C27H1S03, a conclusion reached by a consideration of itsrelations with truxene and tribenzoylenebenzene, C,7H,,0,, butR.St'oermer and G. Foerster33 prepared a methyl ether of thedioxime of a-truxone, and the result of a molecular weight deter-illination in benzene gave the formula C,,H,,O, for truxone.R. Weissgerber and 0. Kruber 34 have performed a remarkabletour de force in isolating four pure dimethylnaphthalenes from theheavy oil coal-tar fraction boiling at9 360-265O.1 : 6-Dimethylnaphthalene is that isomeride which is sulphonaiedmost readily in the cold. Its sulphonic acid was isolated andhydrolysed by steam a t 130-140°. The constitution of the liquidhydrocarbon was proved in several ways, for example, by oxidationto the dicarboxylic acid, which was synthesised in stages fromP-naphthylamine-5-sulphonic acid.2 : 6-B~methylnaphthtulene.-Sulphonation at 135-140O convertsthe 1 : 6-isomeride into soluble products and yields a sparinglysoluble 2 : 6-dimethylnaphthalenesulphonic acid.The hydrocarbonobtained on hydrolysis melts a t llO-lllo, and is identical with thedimethylnaphthalene obtained by Baeyer and Villiger 35 fromionone.2 : 7-Dimethylnaphthalene .-This new isomeride is isolated byremoving as much of the 1 : 6- and 2 : 6-isomerides as possible; a32 Ber., 1919, 52, [B], 1021 ; A., i, 329.33 Ibid., 1255 ; L4., i, 444.34 Ibid., 346 ; A., i, 315.35 Ibid., 1899, 32, 2429 ; A., 1 S99, i, 921ORGANIC CHEMISTRY. 101sulphonation a t 40° of recovered hydrocarbon then gives a pastymixture of acids, which is crystallised from 30 per cent.sulphuricacid. On hydrolysis, 2 : 7-dimethylnaphthalene is obtained (m. p.96--97O), and its constitution was determined by the, usual methods.2 : 3-Dimethylnaphthalene (guaiene, see above) was obtained 36 inrelatively small amount from the soluble sulphonic acids accom-panying the 2 : 6-dimethylnaphthalenesulphonic acid.The results of the work of It. Pummerer and E. Cherbuliez 37 onthe oxidation of l-methyl-@-naphthol are of much interest, but theoriginal must be consulted, as the investigation is too complex tobe1 usefully summarised.An interesting and unexpected observation 38 occurs in thePatent literature'. 1 : 6-Dihydrosynaphthalene is condensed withphthalic anhydride in the presence of boric acid to 1 : 6-dihydroxy-o-naphthoylbenzoic acid, which has a very sweet tastel.The corre-spopding 1 : 5-compound is tasteless.The action of bromine on juglone (I) in hot acetic acid leads tothe formation of a tribromojuglone (11), which is a brilliant redcompound, and constitutes, it is claimed,3Q a naphthalene dye of anew type.0/\AI l l\/\/HO 0Br 0The substance dyes cotAton iikordantecl with tannin in ecru shades,whilst its indigo-blue sodium salt dyes wool and silk directly.Very little of importance has been published during the yearunder review on the chemistry of anthracene, phenanthrene, andhigher polynuclear hydrocarbons.Alicyclic Group.I n 1915, Beesley, Ingold, and Thorpe40 showed that a cyclo-propane ring in the spiro-position wit,h respect t o a cyclohexanering was more readily formed than a simple cyclopropane derivative36 R.Weissgerber, Ber., 1919, 52, [B], 370 ; A., i, 318.37 Ber., 1919, 52, [B], 1392, 1414; A., i, 439, 442; R. Pummerer, Bey.,38 Society of Chemical Industry in Basle, D.R.-P. 311213 ; A., i, 403.39 A. S. Wheeler and J. W. Scott,, J . Amer. Chem. SOC., 1919, 41, 833 ; A.,4O T., 1015, 107, 1080.1919, 52, [B], 1403; A., i, 440.i, 490102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of closely analogous character; also the group I1 was, when formed,more stable than the group I.The conclusion drawn was that a part of the strain on thecyclopropane ring is taken up by the cyclohexane ring, or, in otherwords, that, owing t o the cyclohexane valency angle exceeding thenormal, the valencies a and h enclose a smaller angle than thecorresponding valencies c and d .A similar, but far more complex,study has now been publisheld41 of the va!ency stabilities in com-pounds containing the skeletonsc, “,/C-‘--C ,c -c\ Y,,CP- c>q I lb \c-C’ \c-c >C( 111 and c< c/ ‘C-GFrom the theoretical discussion, it was deduced that ths bolld xshould be distinctly more stable than y, aiid a slight increase ofstability was anticipated in the case of the bond a as comparedwith /3. On the other hand, bond a should be slightly less stablethan 6, although this effect, being of the third order, might proveincapable of detection. Experimental results justified all theaepredictions, but this highly interesting papetr cannot be adequatelycondensed, aiid the reader is referred t o the original for details.A new bicyclic terpene, CIOHIG, which yields pinene nitsoso-chloride with amyl nitrite and hydrochloric acid, has been dis-covered 42 in Finnish turpentine.A new sesquiterpene has beenisolated 43 from a distillate obtained during the manipulation ofpine resin.Active pineiie nitrosochloride has been prepared 44 from themother liquors from which the usual inact’ive compound hasseparated. By heating with aniline, d-pinene was regenerated.By applications 45 of the method of ozonisation, the formula I isconfirmed for d-fenchene (Wallach’s D-l-fenchene), whilst the ex-pression I1 may be assigned with certainty to /3-fenchene (Wallach’snd-f enchenei and Semmler’s isof enchene) .The fenchene, boilinga t 145--147O, is probably 111, whilst the fenchene of lowest boilingdl C. K. Ingold and J. F. Thorpe. T., 1919, 115, 320.42 0. Aschan, Technikern, 1918; A., i, 336.43 0. Aschan, Finska Kem. Medd., 1918 ; A.. i, 338.44 E. V. Lynn, J . Amer. Chem. Soc., 1919, 41, 361 ; A., i, 212.45 R. H. Rosohier, Acad. Sci. Pennicae, 1919, [A], 10, 1 ; A., i, 408ORGANIC CHEMISTRY. 103point (Semmler's isoallofenchene) is probably IV mixed withAschan's P-pinolene (V), the' lather in relatively small proportion.CH,-CH-CH, 3le2C--CH-OH, Me,C--CH-CHC H,-CH-C: CH, CH,-UH-C:CH, CH,-CH-UMe(1.) (11.) (111. )I I I I y e 2 I I YH2 I I YH2 IiThe work of Windaus on cholesterol has been continued, andalthough these investigations cannot yet be usefully summarised, itis considered46 that the constitution of cholesterol has beenelucidated to the extent indicated in the1 expression/\ IIf this is subsequently confirmed, cholesterol will be the firstnatural product shown t o belong to the spiro-ring type.Aromatic Selenium Compounds.Aniline selenate does not yield the selenium analogue ofsulphanilic acid on being heated, but sn-substituted aromaticselenium compounds can be obtained 47 from phenylselenious acid(I).Nitration by sulphuric acid and potassium nitrate yieldsPn-nitrophenylselenious acid (II), which, on reduction with sodiumhydrogen sulphite, becomes di-m-nitrophenyl diselenide (111).The corresponding diamine (IV) may also1 be obtained fromm-nitroaniline by way of its diazonium derivative and m-nitro-46 A.Windaus and 0. Dalmer, Ber., 1919, 52, [B]. 162 ; A , i, 203.F. L. Pyman, T., 1919,115, 166104 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.plieiiyl seleiiocyaiiste.with tin and hydrochloric acid.The latter yields the base (IV) 011 reductioiiSe0,H Se0,H Se-Se Se-Se/\ /\ /\ /\ /I I 1N02 NH,\I \/R. ROB,INSON.PART I11 .-HE: T ER o c Y c L I c D I v I s I ON.THE work of the current year in this field has been somewhat dis-appointing, and the dearth of interesting material accounts for thebrevity of the present Relport. No new lines have been opened upon the grand scale of recent researches on chlorophyll and theanthocyanins, but, instead, a good deal of quiet progress has beenmade' in t h s field of alkaloidal chemistry.The tendency, noted inprevious Reports, towards the study of natural rather thansynthetic products appears still t'o hold, which is a matter forcongratulation.On the purely '' artificial " side, an interesting example of thebenzidine rearrangelment in the glyoxaline serie8 may be mentioned,further study of which might help to clarify our ideas concerningthe mechanism of that peculiar process. The conversion of isatininto a quinoline derivative is also of interest from the point ofview of theory.Apart from these, the1 interest in synthetic organic compoundsseems to have centred in the coumarin and indole groups, whichhave given rise to a number of investigations.The chemistry of natural products is 'represented by a study ofthe anthocyanins, with special reference to colour variation inflowers, and a series of important facts have been brought t o lightin this section of the subject.Steady progress is being made inthe examination of the alkaloids, especially in clearing up theconstitutions of the more recently isolated members of the group.Tlw Rhodim Series.A study of the reactions of thiocyanoacetonel has revealed thefact that, this substance can give rise to several different hetero-cyclic compounds according t o tho reagents employed t o producecondensation, and it now seems established that previous investiga-1 J. Tcherniac, T., 1919, 115, 1071ORGANIC CHEMISTRY. 105tions in this field had led to erroneous conclusions.I n an attemptto prepare thiocyanoacetone, Hantzsch and Weber obtained asubstance which they supposed to be hydroxymethylthiazole, anda t a later date Hantzsch3 believed that he had produced amino-methylthiazole by the action of ammonia on thiocyanoacetone.Both these ideas are found to be mistaken.The reactions with which we are concerned a t present aresymbolised in the following scheme :8H-Yccl +- CH,*CO*CH,*NCS ?!!y 4C,H,ONS\/ 8-iso-MethylrhodimHCI cab*cN2 -ChIoro-4-met.hylthiazolea-MethylrhodimFor the compound now termed a-methylrhodim, Hantzsch sug-gested the structure$H--?CH,*C CO\./NHwhich makes it a derivative of thiazole. The properties of thesubstance, however, do not in any way agree with this formulation.For example, the compound shows no trace of ketonic properties,nor does it behave like an alcohol.Phosphorus pentachloride actson it without displacing oxygen, which appears t o negative theassumption that the oxygen atom exists in the ketonic form or inthe enolic stlructure derivable from the ketone. Hydrolysis of thecompound le8ads to decomposition products, which cannot be derivedfrom such a structure as Hantzsch proposed.It is now assumed that the condensation reaction takes place inthe following stages :CH,*C CiN -+ CH;C C:Nf:K2-? 5H-Y\OH\\02 A. Hantzsch and J. H. Weber, Bw., 1887,Annalen, 1888, %9, 7 ; A . , 1889, 413.p - 7\/+ CH,*C C:NH020, 3127 ; A . , 1888, 256.E106 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY.and it has been shown that this formulation of the end-product isin agreement with the actual propertie6 of the compound.With regard to the nature of isomethylrhodim and &methyl-rhodim, it is too early yet to state that their structures have beendefinitely established.From the fact thatl a-methylrhodim andP-methylrhodim are readily interconvertible, i t seems reasonable tosuppose that the &compound is a polymeride of the other, and thatthe structures of the two are similar. On the other hand,isomethylrhodim has a chemical behaviour different from either ofthe other two substances, and it appears to be expressed most satis-f actorily as a polymeride of the following :fiH--TCH,*C coThe Pyraxoline Group.When phenylhydrazine is allowed to act on phenyl styryl ketone,distyryl ketone, or ethyl y-keto-A"'- pentadiene-a€-dicarboxylate, thephenylhydrazones, which are the first products of the reaction,become spontaneously converted into pyrazolines.Further ex-amination shows that the reaction4 is a general one unless one ofthe following conditions is fulfilled, in which case the phenyl-hydrazone is stable and can be converted into the pyrazoline deriv-ative only by the employment of special processes : (1) The sub-stitution of pnitrophenylhydrazine for phenylhydrazine ; (2) thepresence of a halogen substituenb in the phenyl groups of bothketone and hydrazine; (3) the presence of a methoxy-group in theortho-position in the ketone.When the pyrazoline derivatives obtained by this reaction wereexposed to the influence of Rontgen rays, they exhibited intensefluorescence, not only in the solid state, but also in solution, theintensity of the fluorescence in the latter case being markedlyaffected by the nature of the solvent.The st'ructural conditionsnecessary for the production of this Rontgen ray fluorescence appearto be different from those demanded for the power of fluorescingunder light rays. For example, if the pyrazoline derivative con-tains a phenyl or carbonyl radicle in the positions 3 and ti, i tfluoresces with Rontgen rays, but fails to do so when these un-saturated groups are displaced by hydrogen atoms or aliphaticgroups. Under the action of daylight, however, this substitution4 F.Straw, Ber., 1918, 51, 1457 : A., i, 41ORGANIC CHEMISTRY. 107appears to be insufficient t o destroy the fluorescent power, as suchcompounds fluoresce quite clearly even in diffused daylight.The assumption here made that the pure pyrazoline derivativesare fluorescent may, in the end, prove to be erroneous, as somecases have now been investigated wherein pyrazoline compoundsevidently give rise to highly complicated and strongly fluorescentsubstances,5 and i t is possible that the phenomena described abovemay be attributable, not to the pyrazoline derivative, but ratherto its products.It has been shown that ketopyrazolines containing the structure-CO*CH <N H-, give strongly fluorescent solutions when dissolvedin alcohol containing a trace of hydrogen chloride, and the originof this fluorescence has been traced t o the formation of complexmaterials which resemble in their physical aspect the rhodaminedyes.Thus, when hydrogen chloride is passed into boiling methylalcohol in which ethyl 5-benzoyl-4-phenylpyrazoline-3-carboxylate issuspended, a crimson precipitate is produced which appears to havethe composition C,,H,,O,N,. From i t two other substances havebeen obtained which have the compositions C,BH~O,N,C1 andCBH,0,N4. The latter is a colourless compound, for which thefollowing structure has been proposed :yHPh*C :CPh*r*N:$!*CO,EtC0,Et.C: N---N*CPh: C --CHPhAnalogous results are obtained with some other pyrazolinederivatives.An interesting example of solvent effect has come to light 6 inthe pyrazoline series.When p-bromophenyl styryl ketone isheated with ethyl diazoacetate, an ester is formed which has thestructure (I), but i f the reaction mixture is diluted with lightpetroleum, the end-product is the ester (11) :7'h e Gly orca lin es .A curious abnormality has been detected in the reaction betweencliazonium salts and the glyoxaline derivatives.7 It appears to beestablished as a general rule that diazonium salts will react onlyE. P. Kohler and L. L. Steele, J . Amer. Chem. SOC., 1919, 41, 1105 ; A.,i , 557.E. P. Kohler and L. L. Steele, {bid., 1093 ; A., i, 530. ' R. G. Fsrgher and F. L. Pyman, T.. 1919,115, 217, 1015.E* 108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with those glyoxalines which contain a free imino-group and alsoa hydrogen atom, or a displaceable group (such as a carboxylradicle) in the 2-, 4-, or 5-position.Exceptions to this are, how-ever, found in the cases of 5-methylglyoxalin~4-carboxylic acid andglyoxaline-4-carboxylic acid ; for although the acids themselvesbehave normally and couple with diazonium compounds, the estersdo not react a t all. Up tot the present, no definite deductions canbe drawn from these results, butl it is suggested that the source ofthe abnormality must be sought in some mutual influence of theimino- and carbonyl radicles.I n the course of this investigation, a most interesting exampleof the benzidine rearrangement was observed. When 2-benzene-azoglyoxaline was reduced with stannous chloride.the main pro-duct was found to be 2-amino-4-p-aminophenylglyoxaline, a result.which can only be attributed to intramolecular rearrangement ofthe benzidine typa :NH-- NH NH"It must be admitted that the occurrence of the benzidine changei n the case of a fivemembered ring is extraordinary? but it ispointed out that the conjugation of the bonds in the glyoxalinering furnishes a certain parallel to that which is present in thestructure of hydrazobenzene.A Sy~it7~esi.c of p-Collidirie.In the coursel of some synthetic investigations in the quinineseries, a mode of forming P-collidine (4-methyl-3-ethylpyridine)has been discovered.5 As a first step, 2 : 6-dihydroxy-P-collidine isprepared, either by heating y-cyano-P-methyl-a-ethylglutaconimidewith hydrobromic acid or by condensing ethyl acetoacetate withethyl cyanoacetate in the presence of sodium and treating theglutaconic ester thus formed with sodium hydroxide.The next.stage in the process consists in converting the dihydroxycollidineinto 2 : 6-dichloro-~-collidine by the action of phosphoryl chloride.Finally, the chlorine atoms are removed by means of hydriodicacid ; monochloro-P-collidine is the first, product, from whichP-collidine is formed a t a further stage in the reaction.* L. Ruzicka and V. Fornasir, HeJu. Chim. Acta, 1919, 2, 338; A., i, 550ORGANIC CHEMISTRY. 109The Indole Group.When certain isatogens are heated under pressure with alcoholichydrogen chloride, they yield less intensely coloured isomerides.9It is suggested that the strongly coloured materials correapond withthe structural type (I) containing the1 pseudo-quinonoid grouping,whilst the new products have the linking (11) within the molecule:9 C coIt will be noted that if this view can be substantiated, the changecorresponds with the conversion of a five-membered ring into abicyclic structure containing an extra three-membered ring.The markgd difference in colour between indigotin and its diacetyldelrivative has apparently been accounted for by the proof that tholatter contains both the acetyl groups attached t o the nitrogenatam .loA iiumber of substituted indirubins have been prepared by meansof three different reactions,11 namely, (1) condensation of isatinswith indoxylic acid, (2) condensation of isatins with anilinoisatin,and (3) condensation of isatins in the presence of acetic acid withthe technical fusion of phenylglycine.The yield in the last caseseems good.A new and rapid method far extracting indican from indigo-yielding plants has been worked out .12The Coumarin Group.Among the cycloparaffins, it is well known that t3he stabilitiesof the five- and six-membered rings approximate closelyto one another, for in some cases the five-membered ring can beconverted by intramolecular rearrangement into the six-memberedt.ype and vice versa. A somewhat similar phenomenon has beennoted in the flavons and coumarin series, where the ring containsan oxygen atom in place of one of the methylene groups of theP.Ruggli, Ber., 1919, 52, [B], 1 ; A., i, 221.lo D. Vorliinder and J. v. Pfeiffer, ibid., 325 ; A., i, 225.l1 J. Martinet, Compt. rend., 1919, 169, 183 ; A., i, 457.l2 33. M. Amin, AgriC. Rea. Inst. Pusa, Indigo Publ., No. 5 ; A., i, 283110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.cycloparaffin. Thus, when a benzylide!necoumarone of the gelneralstructure (I) is treated successively with bromine and potassiumhydroxide solution, it may be converted into the’ correspondingflavanone (11) :(1.1 (11.)Another branch of the same subject was opened up by the dis-covery that the removal of hydrogen bromide from substances ofthe general type (111) may take place in either of two ways, result-ing in t4he one case in t-he production of a flavone derivative (IV)and in the other in the synthesis of a coumarin compound (V):0 OH 0(Iv.1 (111.) (V. 1During the present year a study has been made13 of certainexamples of this type with the view of determining the effect ofsubstituents on the course of the reaction.From the results which have been accumulated, it appears as ifthe governing factor in the problem is the position of substituentsin the phenyl radicle which lies nearest the double bond in themolecule of the type (111). Thus, 2-acetoxyphenyl 4-methoxystyrylketone dibromide yields a coumaranonel derivative when treatedwith concentrated potassium hydroxide, whereas the isomeric2-acetoxyphenyl 2-methoxystyryl ketone gives a flavone compoundwhen similarly treated.This recalls to some extent the phenomena observed in the form-ation of coumarones from phenoxy-acetals714 in which case theinfluence of substituents is so great that i t may inhibit the reactionof coumarone-formation completely.Thus the compound (I) yieldsthe coumarone (11), but no such ring-formation takes place at allif a methoxy-group is inserted into the benzene ring in a positionortho t o the side-chain, as in (111).OMeA. - 0 /\--o p , - 0 I t I - + I ‘ , / \ A H \/)HZCH (OEt), CH\/‘H /CH,CH(OEt),(1.1 (11.) (111.)I3 J. Tambor and H. GubIer, HeZu. Ckim. Acta, 1919, 2, 101; A., i, 215.R. Stoermer, Anwlert, 1900, 312. 334; A., 1900, i, 650ORGANIC CHEMISTRY. 111A somewhat analogous investigation has been made with regardto the influence of substituents on the stabilities of variouscoumaranone derivatives. By treating the coumaranone derivativewith nitrophenylhydrazine, itq is found possible t o determinewhether or not a rupture of the heterocyclic portion of the mole-cule has taken place or not under these conditions.15 It appearsLhat the furan ring of the 1 : 1-dialkylcoumaranones shows greatstability, as in such a case hydrazone-f ormation occurs withoutrupture of the ring.Another example of a similar kind is t o be found in some recentwork on the o-allylphenols .I6 When o-allylphenol is submittedsuccessively to acetylation, bromination, and treatment withalcoholic potassium bromide, i t might be expected, from analogy toKostanecki’s syntheses, that the parent substance of the flavones,‘‘ chromene” (I), would be formed.Actually, however, the reactiontakes another course, and a five-membered coumarin ring is pro-duced (11). The reaction appears to be a general one.(1.1 o- Nlylphenol (11.)Since the coumaranones might be supposed to be capable ofenolisation, it is of some interest to find17 that both chemical andspectrochemical evidence tends to show that they are purely ketonicin nature, there being pracOically no enolic modification detectableeither by measurements of refractive indices or by titration withbromine.Three new methods for the synthesis of chroman and coumaran 18have been devised, zinc chloride being used as a condensing agentin each case. In the first method, phenol is condensed with achlorohydrin, and a poor yield of the required product is obtained.Better results are obtained by using phenyl y-hydroxypropyl ether(obtained by the action of trimethylene chlorohydrin on sodiumphenoxide) .When heated with zinc chloridel, this compound givesa 30.per cent. yield of chronian. By employing ethylene chloro-hydrin and sodium phenoxide, phenyl P-hydroxyethyl ether isformed, and gives a 25 per cent. yield of coumaran on heating with16 K. von Auwers and E. Adenberg, Ber., 1919, 52, [B], 92 ; A., i, 218.16 R. Adams and R. E. Rindfusz, J . Amer. Chem. SOC., 1919, 41, 648 ; .A,1’ K. von Aumers, Ber., 1919, 52, [B], 113; A . , i, 230.I* R. E. Rindfusz, J . Amer. Chem. &., 1q192 41, 665 ; A., i, 342.i, 340112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.zinc chloride.The action of zinc chloride on phenyl y-bronio-propyl ether produces a 65 per cent. yield of chroman, whilst theanalogous reaction with phenyl P-bromoe'thyl ether leads to a3 0 4 0 per cent. yield of coumaran.The Conversion of Isatin into (8 Qzcindine Derivative.Another example of the change of a five-membered heterocycliccompound into one containing 8 six-membered ring is furnishedby the conversion of indoles into quinoline delrivatives. Thischange is brought about in some cases by the action of nitrowfumes, 2-cyano-2 : 3-dihydroindole-2-carboxylamide being thus trans-formed into 2-hydroxyquinoline-3-carboxylamide.~~ It has nowbeen found 20 that diazomethane possesses the power of effecting asimilar change.When this reagent is allowed to act on isatinsuspended in ether, 2 : 3-dihydroxyquinoline is produced.A New Heterocyclic T?ypc.It will be remembered that by means of Skraup's reaction it ispossible to fuse a newly formed pyridine ring on to an alreadyexisting benzene nucleus. I n the case of the formation of quinoline,an aromatic amine is treated with glycerol and sulphuric acid inthe presence of an oxidising agent such as nitrobenzene. Thisreaction has now21 been utilised in order to fuse a pyridine ringon to a coumarin nucleus, with the production of a nelw type oftricyclic compound in which all three rings differ in character, onebeing a pyrone ring, the central one a benzene ring, and the thirda pyridine nucleus.It has been found that! the1 reaction takes place with great readi-ness, so much so that i t is undesirable to utilisei aminocoumarinsa t all, the nitro-derivatives being sufficient ; and this naturallysimplifies the synthesig considerably.When 6-nitrocoumarin is treated with glycerol and ,sulphuricacid in the usual manner, condensation takes place, with the form-ation of t-he intermediate compound (I).This mipht then condenseintrainolecularly in either of two ways, as shown in the formulze:G. Heller and P. Wunderlich, Ber., 1914, 47, 1617 ; A., 1914, i, 863.*O G. Heller, ibid., 1919, 52, [B], 741 ; A.. i, 283.2' R. B. Dey and M. N. Goswami, T., 1919,115, 531ORGANIC CHEMISTRY. 1.1300(111.)Conclusive evidence is st.ill lacking as to which of these com-pounds is produced, but the balance of probability inclines towards(111).Such a substance would logically be termed $-1:8-&0-naphthoxazone.The chemical character of the $-naphthoxazones does not differmarkedly from that of other quinoline derivatives except in twopoints. In the first place, the $-naphthoxazones dissolve in hotalkali hydroxides, yielding substances of a deep colour, whichappear to be unstable acids formed by the opening up of the pyronering, since they regenerate the parent, naphthoxazone when treatedwith acids. Secondly, although the $-naphthoxazones are colour-less and form colourless salts with acids, yet their additive productswith alkyl iodides possess deep colours ranging from dark yellowto scarlet-red.When dissolved in water, these ammonium saltslose ttheir colour. From this it would appear that the ions derivedfrom the ammonium salts are colourless, whilst the non-ionisedmaterial is coloured . Further investigation of this phenomenonpromises interesting results, as the case is evidently the converse ofthat of phenolphthalein and other indicators, which are colourlessin the molecular condition but yield coloured ions in solution.The Flawone Series.This branch of the hete<rocyclic compounds has been less workedon recently, but some progress is to be noted. By investigations inprevious years, the constitution of scutellarein had been narroweddown t o two alternative possibilities, for it might be either5 : 7 : 8 : 4’- or 5 : 6 : 7 : 4/-tetrahydroxyflavone.It has now22 been22 G. Bargellini, Gazzetta, 1919, 4@, ii, 47 ; A., i, 645I14 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.shown, apparently, that the latter view is the correct one, so thatthe st,ructure of scutellarein is that shown below (I).The synthesis of datiscetin appears to have been acconiplished,23although, on account of the lack of material, i t has been impossibleto carry out the last step in the process, the demethylation of thetrimethyl ether of datiscetin. It seems clear, however, that thesynthetia 5 : 7 : 2’-trihydroxyflavanol is identical with the, trimethylether of datiscetin. The formula of the synthetic product is shownabove (11).A number of amino- and azo-derivatives of the flavone serieshave been prepared, and their properties have been examined. Theresults show that the amino-group exerts a stronger auxochromicinfluence than does the hydroxyl radicle.24The Anthocyanins.I n the earlier stages of the investigation of the’ anthocyanins, thereduction of quercetin was shown to produce cyanidin, and in thisway the genetic relationship bet-ween the flavone and anthocyaninseriea was established .25 I n these researches, the reducing agentemployed was magnesium and hydrochloric acid, acting in theprmence of mercury.A further examination of this field has ledto most interesting results.% Instead of hydrochloric acid, organicacids have been employed t o act on the magnesium or zinc whichis used in the reduction of the flavonel derivative, and in this modifi-cation of the method certain complex salts are produced whichappear to throw light on the problem of plant colorations.For example, when myricetin (I) is reduced by this method ityields green-tinted compounds which have the compositionApparently the reaction proceeds in stagw, the phenopyryliumderivative (11) being formed first, and then passing by eliminatioii2* G.Bargellini and E. Peratoner, Gazzetta, 1919, 49, ii, 64 : A., i, 547.24 M. T. Bog& and J. K. Marcus, J. Amer. Chem. Soc., 1919, 41, 83 ; A.,2s Ann. Report, 1914, 11, 138 ; 1915, 12, 156.26 K. Shibata, Y. Shibata and I. Kasiwagi, J . Amer. Chem. SOC., 1919, 41,C,BH,,O,*Mg*OAc,[Mg(oAc),l,.i, 169.208; A., i, 166ORGANIC CHEMISTRY. 115of acetic acid into (111), which finally unites with magiiesiuniacetate to produce (IV).When, instead of myricetin itself, aOHOAc Mg*OAc\/ OHrhamnoside derivative, myricitrin, is employed, the reactioii givesrise to a deep blue substance which contains four molecules ofmagnesium acetate.It will be remembered that hitherto the reduction of flavonederivatives has always given rise, to red materials. The apparentanomaly is explained by the fact that when these new green orblue reduction products are treated with hydrochloric acid, theyalso yield red compounds, the action of the hydrochloric acid bring-ing about the displacement of the group *Mg*OAc by a chlorineatom, with the consequent formation of the red oxonium chloride.It has been proved, however, that even when hydrochloric acid ispresent, in certain casw a green or blue material may be formedwhich contains the group *MgC1 instead of the radicle *Mg*OAc.The change of colour induced by the elimination of themagnesium atom from the substances is attributed by the authorst o two possible factors.I n the first place, the phenopyrylium rin116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.contains one hydroxyl group more than does the correspondingoxonium salt, and in the second place, the magnesium atom isassumed to take part (by means of auxiliary va1encie.s) in complex-formation. I n support of this, it may be pointed out that thereduction of a glucoside (in which one of the hydroxyl groups ofthe compound is displaced by a sugar molecule) proves that thismasking of the hydroxyl tends t o shift the absorption band towardsthe violet, whilst with regard to the other factor, compounds con-taining the group -MgCl (which is supposed to be lem active thanMgOAc in complex-f ormation) have green instead of blue colours.The authors have thus been led to put forwardviews as t o the cause of colour variation in flowers.them, metallic complex salts of the following typeMX0Ithe followingAccording toare importanti _Jfactors in flower coloration and give rise to the “blue ” antho-cyanins.The metals which they contain are probably calciumand magnesium. The “ violet ” and “ red ” pigments are assumedt o be complex salts containing felwer hydroxyl groups than the“blue” ones have, or t o be mixtures of the “blue” compouiidswit<h some red oxonium salts which have been formed from the‘ I blue ” compounds by decomposition with acids.Experiments on the action between natural anthocyaiiins aiidsolutions of the salts of alkaline earth and heavy metals appear t ofurnish evidence in support of the authors’ contentions.,4 N e w Ii~ydrastin,ine Synth esis.37By the action of chloroJmethyl alcohol on homopiperoiiylamine(I) in ethereal solution, homopiperonylaminomethanol (11) isformed, and this, when treated with 10 per cent.aqueous hydro-chloric acid, yields dihydronorhydrastinine (111), from whichhydrastinine itself can be obtained. The following formulae showthe steps in the process:( 3 3 2 CH2(/\A O / \ ACH2<()I I yHZ CH2CI.0H CH2<01 I y H 2 \/ NH, ___ + \/ NH/CH2*OH(1.1 (11.)27 K. W.Rosenmund, Ber. Deut. pharm. Ges., 1919.29, 200 ; A., i, 280ORGANIC CHEMISTRY. 117(111.)The Cirkchona A ZkaZoids.Further progress has been made in this group, but the resultsare not yet published in full, so that it is impossible to give1 a com-plete account of the work which has been carried out.It has been found2* that, by means of palladous chloride in dilutesulphuric acid solution, it is possible t o reduce cinchoniiie,cinchonidine, and quinine t o the corresponding hydro-compounds.Some experiments have been made29 in coupling cinchona deriv-atives with diazobenzene and reducing the products.A claim is put forward30 that the cinchona alkaloids can now hebuilt up from quinoline and piperidine compounds.In this form,the claim is possibly correct, but as the material which the authorsemployed was obtained, not by synthesis, but from t'he degradationproducts of the alkaloids themselves, it is evident that the completesynthesis of the cinchona alkaloids is still unachieved .Some intramolecular changes in cinchonidine have beendes~ribed,~I and the decomposition products of P-hydroxycinchoninehave been investigated.32Hyoscine and Oscine.The complications introduced into the study of alkaloids by theexistence of spatial relations are well illustrated in the case of thehyoscines. Hyoscine occurs in two optically antipodal forms,cl-hyoscine and Z-hyoscine, and this year an investigation33 has beenmade with the object of determining the stereocheinical relationsof these compounds.Since the hyoscines are compounds built up from tropic acid andoscine, and since each of the latter occurs in two antipodal forms.it is evident that there are no fewer than eight isomerides possible:if racemic and partly racemic varieties are included.These may28 M. Heidelberger and W. A. Jacobs, J . Amer. Chem. SOC., 1919, 41, 817;29 G. Giemsa and J. Halberkann, Ber., 1919, 52, [B], 906 : A . , i, 34230 P. Rabe and K. Kindler, ibid., 1918, 51, 1360: A . , i, 33.31 E. LBger, Compt. rend., 1919, 169, 67 ; A., i, 451.s2 Ibid., 168, 404 ; A., i, 170.33 H. King, T., 1919, 115, 476, 974.A., i, 493118 ANNUAL REPORTS ON THE PROGRESS OB CHEMISTRY.be represented by the following symbols, in which T stands fortropic acid and 0 for oscine:Partial Opticallyracema t es .pure forms./ I * z-T-d-o5. dl-T-d-0 Ic/ 2. 1-T-1-0\//\3. d-T-d-06. dl-T-d-0-\ 4. d T-1.0Partialracema tes ./+8. d-T-dl-0\+/+Now, when I-hyoscine is hydrolysed with either acid or alkali, ityields I-tropic and dl-oscine. This excludes from the above listall the first six possible structures, since 1-6 contain either d-tropicacid or an active form of the oscine, so that for Z-hyoscine we areleft with 7 and for d-hyoscine we are driven to choose 8.When the problem of optically inactive hyoscine is considered, itwill be' found even more complex. As a starting point, there arefour possible varieties of the active forms :1.I-tropyl-I-oscine,3. I-tropyl-d-oscine,2. d-tropyl-d-oscine,4. d-tropyl-Z-oscine.Inspection of these will show that 1 and 2 would form an inactivecompound when mixed together, as would also 3 and 4. Further,these two inactive mixtures could not be identical with each other,owing to the different mode of linking between the right- and left-handed forms of the acid and base. Finally, a third inactivemixture might be obtained by mixing all four varieties together inmolecular proportions, and if combination took place between themthis would represent the production of a third possible type ofsubstance in the crystalline form.Now, i f the formation of an ordinary racemic compound beassumed, in which only two molecules combined to form the inactivecrystal, it might reasonably be expected that two different types ofcrystals would be obtained, corresponding with the two pairs (1 4- 2)and (3+4) above.On the other hand, i f all four varieties arecombined together in one crystal, then no second crystalline com-pound need be expected. I n actual practice, only a single form oft*he crystalline racemate is known, which may be taken as support-ing the combination of the four active forms into one crystal.King, on the basis of his investigations, suggests that the formulORGANIC CHEMISTRY 119of oscine is allied to that of tropine, and considers that it may havethe structureThe Alkaloids of the Pomegranate Tree.The difficulties which beset investigators in the field of alkaloidalchemistry are well illustrated by this group of compounds.I n1917, researches showed that a reform of the nomenclature wasrequired, whilst this year further facts have come to light whichapparently point to an isomerism depending on the spatial arrange-ment of groups about a tervalent nitrogen atom.It has been proved 34 that methylisopelletierine has the structure(I), and that i t can be obtained from conhydrine, which appearsto be (11). Closer examination of this reaction, however, showsthat, along with methylisopelletierine, a second base, db-methyl-conhydrinone, is produced.35 The two bases give different oximesand hydrazones, which excludes the idea that the difference betweenthem is due to keto-enolic desmotropy.Hess is therefore driven to suggest that the isomerism should beascribed to a different, sitluation of the methyl group in the com-pounds in question.I f the piperidine ring be supposed to beopened out and then placed in the plane of the paper, the followingformulze illustrate the conception :C0Et.C.H H *C.COEt COEt-OH H*d&OEt +I '+ + II I I+&*~c~e TtLe*N MwN+ +N*MeI[7H214a. 6.In the formula b it will be seen that t.he methyl radicle is supposedto be spatially adjacent t o the carbonyl group, whilst in formula nthe carbonyl and methyl radicles are on opposite1 sides of the ring.Steric hindrance is thus assumed t30 account for the fact that on0s4 K. Hess and A. Eichel, Ber., 1917, 50, 1192, 1386 ; A., 1918, i, 33, 34.35 K.Hess, ibid., 1919, 52, [B], 964 ; A., i , 345120 ANNUAL &E;YORTS ON THE PROGRESS OF CHEMISPRY.compound reacts more readily with semicarbazide than does theisomeric substance.A suggestion of this kind is not new,36 but the present caseappears t'o be differentiated from previous ones in that the isomerismis still preserved when methyl iodide is added on to each isomeride.Up to the prwent, i t has not been possible to bring about the con-version of methylisopelletierine into dl-methylconhydrinone. Themethylation of d-conhydrinone by means of methyl sulphate pro-duced a mixture of racemic methylisopelletierine and methyl-conhydrinone.COEtThe occurrence of isopelletierine, /-\NH, among the pome- \-/granate tree alkaloids has now been e~tablished.~~The Areca Xut A lknloids.The areca or betel nut contains numerous alkaloids, and it must,be confessed that the literature of this branch of chemistry containsan almost equally numerous flock of erroneous observations anddeductions.Nearly all the work which was summarised in lastyear's Report on this subject38 has now been shown to be erroneous.Taking the results in the order in which they were dealt with lastyear, the following must be noted. Arecaine was supposed to bedefinitely proved to be an X-methyl derivative of guvacine. Thisidea seems now to be abandoned. Guvacine appears to be 1 : 2 : 5 : 6-tetrahydropyridine-3-carboxylic acid, and not the 4-carboxylic acidas was supposed last year. This change entails a correspondingalteration in the formula of guvacoline, which is guvacine methylester. Arecaidine is the 1-methyl derivative of guvacine, and areco-line is arecaidine methyl ester.The supposed conversion of methyl-guvacine into the ethyl ester of guvacine by boiling with alcoholichydrogen ahloride turns out to be an error due to the employmentof impure materials.These errors have been frankly admitted by their authors, so it36 See Ladenburg, Ber., 1893, 26, 854 ; 1903, 36, 3694; 8., 1893, i, 442 ;1904, i, 92 ; but compare Wolffenstein, ibid., 1894, 27, 2615 ; A., 1894,i, 627. See also Groschuff, ibid., 1901, 34, 2974; A., 1901, i, 745; andScholtz, itid., 1910, 43, 2121 ; A., 1910, i, 634.37 K. Hess, Ber., 1919, 52, [B], 1005: A., i, 348.3* Ann.Report, 1918, 15, 107 ; K. Freudenberg, Ber., 1918, 51, 1668 ; A . ,i, 93 ; K. Hess and F. Leibbrandt, ibid., 1919, 52, FBI, 206 : A., i, 220 ; E.Winterstein and A. B. Weinhagen, Zidsch. physiol. Chern., 1918, 104, 45 ;A . , i, 171ORGANIC CHEMISTRY. 121may be assumed that 110 further coiitroversy will arise in this parti-cular region of-the subject.The Purine Group.By far the most iinportaiit work in the purine group duringrecent years is that done by Johnson and his collaborators, whichhas iiow reached the) eighty-eighth paper on the pyrimidines.39 Ithas been impossible to give even the most niodest account of thedetails of this vast investigation froin year to year, as the papersdo not leiid themselves t o condensation; but it seems advisable todirect attention here to the extraordinary fertility which this branchof the subject has exhibited in the hands of the investigat,ors, whohave made it their owii. The work done in this field and in thekindred one of the hydantoins represents one of the most fruitfulresearches in nioderii organic chemistry.Apart from this, the purine group has yielded but little ofinterest during the current year.Some work has been done 011hydurilic acid and s-diinethylhydurilic acid,40 but it calls for nop i tiadar comment.Our knowledge of cryptopine has been exhided considerablyduring the present year; but the paper 41 on the subject extends to110 less than seventy-eight pages, and even a summary of it would betoo long for inclusion in this Report.The reader is thereforereferred to the Transactions for further information.The bark of Croton gzcbouga has been investigated,&Z and from itan acid has been extracted which appears to be 4-hydroxyhygricacid, since on methylation it yields a mixture of betonicine andturicine. The properties of betonicine and turicine have beenstudied in detail:HO* H-vH2 HO*YE€-YH,CH, CH*CO,H CH, CH-CO\/ INMe,--O\/NMe4Hydrosyhygric acid. Betonicine and Turicine.39 T. B. Johnson and I. Matsuo, J. Awaw. C?Lem. SOC., 1919, 41, 782 ; T. B.4o H. Biltz and M. Heyn, B e y . , 1919, 52, [B], 1298 ; A., i, 491.41 W. H. Perkin, jun., T., 1919, 115, 713.4z J. A. Goodson and H. W. B. Clewer, ibid., 923.Johnson and L. A. Mikeska, ibid., 810 ; A., i, 498, 499122 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Further investigations of the harmine group have led to the coii-clusion that the structures proposed for harmine in the past areincorrect.It is now suggested 43 that the following formulE repre-sent the conipounds better :Harmine.Harmaline.The details of the evidence on the matter do not lend themselves tosummarisation, and must be consulted in the original paper. Somesuggestions as to the possible mode of synthesis of the compounds inthe plant are put forward; the detaiIs of these are t o be found inthe Report on Physiological Chemistry in this volume.A study of the action of nitric acid on brucine** leads to thefollowing results. The steps in the process may be represented asfollows :C,,H,,O,N, + C,,H&,N, -+f&H190@3 + C,,H,iO,N3,HNO3.The last compound is cacotheline.I n its general behaviour itresembles the nitroquinones except for the fact that treatment withsulphurous acid changes it into a deep violet or green substance,whereas one would expect a less intensely coloured quinol to be pro-duced in this reaction. It seems now to be established that theviolet substance is not a reduction product, but is formed from thecacotheline by isomeric change. This invalidates the previous argu-ment against the nitroquinonoid structure of cacotheline, whichtherefore seems to be established.The action of diazonium compounds on various alkaloids has beenstudied, and it is found 45 that morphine is the only member of theopium alkaloids which yields a true dye in this way.The reductionof the dye failed to yield any aminomorphine. Methyl- and ethyl-morphine do not give dyes. Curiously enough, the physiological43 W. H. Perkin, jun., and R. Robinson, T., 1919, 115, 933.44 H. Leuchs, Ber., 1918, 51, 1375 ; A., i, 35.4 5 L. Lautenschlkiger, Arch. Pharm., 1919, 257, 13 ; A., i, 344ORGANIC CHEMISTRY. 123action of morphine is destroyed by the conversion into the colouriiigmatter.Oxidation of thebaine by means of hydrogen peroxide leads to theelimination of methyl alcohol and the production of a tertiary basewhioh has ketonic properties.46 It is supposed that this base isallied to codeinone, which contains one oxygen atom less; and it istheref ore termed osycodeinone.On reduction, it yields oxydihydro-codeinone, which is supposed to have the following structure:CHThe compound forms a hydrochloride freely soluble in water andsufficiently stable t o allow of the solution being sterilised. Thehydrochloride serves as a narcotic under the name of eukodal.The synthesis of cytisoline appears to have been accomplished,and it is thus proved to . be 2-hydroxy-6 : 8-dimethylq~inoline.~~Assuming this to be correct, Spath 48 suggests that the most probableformula for cytisine is :CH,*CHMeNH*CH/ \c-c ) c 4 .CH,--N ‘ 9 / \CH\CO----C H//The group of anhalonium or cactus alkaloids 49 has been examinedduring the current year.50 Anhaline has been shown to be identicalwith hordenine, so that its formula must beHO*C,H,-CH,*CH,*NMe,.Mezcaline has been synthesised, and proves to be p-3 : 4 : 5-trimeth-oxyphenylethylamine, C,H,(OMe),*CH,*CH,*NH,. These substances46 M. Freund and E. Speyer, Munch. med. Woch., 1917, 64, 380 ; A., i, 345.4 7 E. Spilth, Monatsh., 1919, 40, 93 ; A., i, 453.4 a Ibid., 15 ; A . , i, 4.51.4 9 See also this year’s Report on Physiological Chemistry.5 0 E. Spiith, Monatsh., 1919,40, 129; A.. i, 548124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.do not, properly speaking, belong t o this section of the Report, asthey are open-chain compounds, but it seems well t o include themwith the rest of the alkaloids.Misc ellane ow.The nitration of 5diphenyldihydroacridine and the reduction ofthe nitro-derivatives to amines51 has led to the discovery of a newclass of dyes which have been termed carbazines. The amino-com-pounds act as leuco-compounds, and yield the dyes by oxidation.Some furt.her work has been carried out on the methyluric acids."?By t,he condensation of quinolinic acid with various polyhydricphenols, a series of dyes has been prepared which are analogous tothe phthaleins.537Hexacyanogen, CN*C <x:C(CN)>N, has been obtained by heat- N. C (CN) .~ing a mixture of cyanuric tricarboxylamide and phosphoric oxide ina vacuum to about 250°.54 When passed over a hot platinum wire itdecomposes into dicyanogen. Water decomposes it by the elimina-tion of the three cyanogen groups with the production of cyanuricacid. Hexacyanogen appears to be unattacked by chlorine or iodine,and seems to be indifferent towards hydrogen chloride.Iiivestigation of the action of potassium cyanate on Schiff baseshas led to the discovery that the reaction is markedly influenced byt,he nature of the base used.55 Thus benzylideneaniline reacts withpotassium cyanate, with the formation of a four-membered cycliccompound :CHPh:NPh + HCNO=CHPh<NH->CO, NPhwhilst benz~'1ideiieethylainine yields a six-mem bered ring owing totwo molecules of isocyanic acid taking part in the process:CHPhzNEt + 2HCNO= CHPh<NH-Co N tC:t*CO>NH*The four-membered ring is easily broken down, and yields on hydro-lysis a mixture of benzaldehyde and phenylcarbamide; but it hasbeen shown that this reaction cannot be reversed, since these twosubstances do not condense together to produce any yield of theuretidone from which they are formed.2, 315, 379; A., i, 551, 552.51 F. Kehrmann, H. Goldstein, and P. Tschudi, Helv. Clbim. Acta, 1919,5 2 H. Biltz and 31. Heyn, Ber., 1919, 52, [B], 768, 784; A., i, 292, 293.53 P. C. Ghosh, T., 1919, 115, 1102.54 E. Ott, Ber., 1919, 52, [B], 656 ; A., i, 260.5 5 W. J. Hale, J . Arner. Chern. Xoc., 1919, 41, 370 ; W. J. Hale and N. A.Lange, ibid., 379 ; A., i, 224ORGANIC CHEMISTRY. 125I n view of further developments in this field of research, thefollowing nomenclature for these f our-membered ring-systems hasbeen put forward:NHCH,/ \CH, CM A 3 H \*/ /y\\gH../' \NH/CH,Q ., z\CdUretidoiie. Uretidine. Uretc.N --CH< >CONHUre tine. Uretone.A new method of preparing pyrrole-black has been discovered .sf;Pyrrole is ,treated with the calculated quantity of a very diluteethereal solution of magnesium ethyl iodide, and air is 'then drawnt,hrough the liquid for twenty-four hours. The pyrrole-black isdeposited from the solution and exhibits a much inore intense tintt,han is show11 by samples prepared by other niet,hods.A bicyclic seleriiuin heterocyclic coiiipound,5ihas been obtained by treating two niolecules of yutinaphthylenedi-amine in pyridiiie solutioii with one molecule of selenious acid dis-solved in aqueous pyridiiie. Some reactions of the substance aredescribed.A new series of compounds, described as parazenes, has been pre-pared.58 Members of the series contlain two benzene (or similar)nuclei linked together by two nitrogen atoms, each of which isattached to two para-carbon atoms in the rings. Three possiblephases for such a structure are shown below. I n the case whereone of the phenylene groups contains a substituent, all three phaseswould be different ; but in symmetricallybhe parent coiiipouiid the phases (I) andA. Angeli an2 A. Pieroni, Atti R. Accad.5 7 0. Hinsberg, Bey., 1919, 52, [B], 21 ; A.,6 8 A. Angel. Brit. Pat. 121347 : A.. i. 98.A . , i, 134.substituted menibers or in(111) would be identical:/"\/ \/\N//\ /\- 1 1 (1(TIT.)fiincei, 1918, [v], 27, ii, 300;i, 226126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The parazenes are obtained by acting with a condensing agent onbenzene or naphthalene derivatives which contain an amino-groupand a halogen atom in the para-positioii with respect to each otherand subsequently reducing the hydrosy-parazene thus produced.The members of the series are coloured compounds which yieldcolouring matters suitable for dyeing.I n concluding this series of Reports on the Heterocyclic Divisionof Organic Chemistry which have now been written by him for anumber of years, the author is again coiiscious of the limitationswhich are imposed on a reporter by the nature of the subject, andalso by the considerations of space. He is only too well aware thatmany most interesting subjects have not been dealt with evencursorily in these Reports year by year. This has not been due t oany lack of appreciation on his part. Some important papers havedefied the process of summarisation altogether ; others have beenomitted because of limitations in the space which it is possible t oallot t o the Report. In no case has any paper been left unmen-tioned without due reason; but it has obviously been impossible toconvert the Reports into a mere catalogue of subjects which havebeen investigated during the year. With this apology, the authorbrings his work t o a conclusion.A. IV. STEWART

ISSN:0365-6217    

DOI:10.1039/AR9191600055

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THE transition stage from war to peace during the past year hasbeen indicated in analytical chemistry by the appearance ofnumerous papers, the previous publication of which had been with-held on national grounds. Most of these communications, how-ever, are concerned with matters of more purely technicalimport4ance, and are therefore more suitably dealt with in theAnnual Reports of the Society of Chemical Industry. There hasalso been a number of belated abstracts of papers published twoor thre'e years previously in German journals, which, until a fewmonths ago, were not accessible to English readers.The scarcity of platinum, which was one of the immediate con-sequences of the war, has been intensified by the continuance ofunsettled conditions in Russia.Increasing attention has thereforebeen given to the preparat.ion of platinum substitutes for analyticalapparatus.l Comparative tests with alloys containing from 70 t o90 per cent. of gold and 10 to 30 per cent. of palladium (palath and?*hofaniz~??t) have shown that in some respects these are superior t oplatinum for analytical work, but are less suitable for fusions withalkali hydroxides.2 I n such cases, silver vessels are preferable evento platinum.3 An alloy of nine parts of gold with one part ofcopper is recommended in place of platinum for cathodes, whilst foranodes the alloy is coated with platinum.* Good results have alsobeen obtained in the electrolysis of gold by the use of an ironanode1 in place of platinum, whilst' platinum gauze is used as thecathode.6Physical Methods.Solutions of sucrose and mixtures of ethyl alcohol and waterhave been recommended as suitable standard substances for cali-Compare Ann. Report, 1918, 118.L. J. Gurevich and E. Wichers, J. I n d . Eng. Chem., 1919, 11, 570 ; A.,L. Quennessen, Bull. SOC. chim., 1919, [iv], 25, 237 ; A., ii, 292.P. Nicolardot and J. Boudet, ibid., 84 ; A., ii, 166.J. Guzmhn, Ana7. Fis. Quim., 1919, 17, 115 ; A,, ii, 300.ii, 347.12128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.brating viscosimeters. The method of expressing the results in“ centipoises ” has the advantage thatl the absolute and specific.viscosities thus expressed are the same when compared with watera t 20° as the standard.7The “viscosity value” of an oil, 2, may be calculated by meansof the formula Z = 4.0723 + 3-518/E, where E represents Englcrdegrees.By plotting this value in relation to the temperatures, aseries of nearly straight lines is obtained, which cut one anotherapproximatlely at’ one point, Z = 1 and t=185”. This is applicableto numerous oils. The viscosity of mixtures of oils is not propor-tional to the ratio of the constituents, but may be calculated bymeans of the formula El + = (rtlE, + kn,E2) (nl + kn,), where E ,and E, represent the respective viscosities of the oils, E, being thatof the more fluid, nl and ng their respective proportions, andA gas pyknometer has been devised consisting of a cylindricalvessel with capillary openings a t the ends, closed by meaiis ofrubber fittings and screw clips.The vessel is first charged withclean, dry mercury, and gas then drawn into it) and weighed. Thedensity is calculated by means of t’het formulak = .I/E,E,.*1 +0*00367t d = --+1 (’i: ) 1 +0*003~7ttg’in which 9 represents the weight, of the, pyknometer, 9-11 theweight of pyknometer+air, IT t’he volume1 of the pyknometer, tthe temperature at the time of filling, and t’ the temperature atthe time of weighing, s the density of air in the vessel at t , and t?the relative, density of the gas (air=1).9A method of measuring the size of ultramicroscopic particles,such as smoke in air, has been based on the photography of t<heirpath in the field of an ultramicroscope, which lies in an alternatingelectrostatic field.The degree of oscillation gives the data for.calculating the diameter of the particles.l*The following formula may be used for estimating the amountof finely divided material suspended in a liquid from the absorptionof light, 1 -Z/Io= e - B / n @ , where Z/I(, represents the coefficient ofthe transmission of light, the mass of suspended particles, aiiclAnn. Report, 1916, 166.7 E. C. Bingham and R. F. Jackson, Bull. Burmu of Standards, 1918, 14* E. Oelschlager, Zeitsch. Ver. Deutsch. Ing., 1918, 422.69 ; A., ii, 268.K. Kling and L. Suchowiak, Metan, 1917, 1, 37 ; -4., 1920, ii, 15.lo P. V. Wells and R. H. Gerke, J. Amw. Che712. SOC., 1919, 41, 312; A.,ii, 187ANALYTICAL CHEMISTRY. 129B and fi constants which vary with the nature of the particles andwave-length of the light .I1The accuracy of observations in ultra-violet absorption spectro-scopy is increased by the use of a new form of spectrophotometerin which four sector-shaped openings are arranged diagonally aboutthe optical axis.The result of this is that all parts of a circularbeam of light are utilised in their proper proport!ion independentlyof the size of the aperture.12Attention may also be directed to a series of papers on the con-struction and technical applications of the refractometer.13I n a study of the freezing points of solutions, it has been shownthat the weight of solvent, W , may be replaced by the expremionw+bw, where w represents the solute and b a constant varyingwith the experimental conditions.I n the case of a solvent con-taining several solutes, the observed total depression of the freez-ing point was found to differ but little from the sum of the calcu-lated depressions for the individual solutes.14 The limitations ofthe method as applied t o quantitative analysis are discussed.Although under f avourable conditions the method will give resultsaccurate within about 2 per cent., previous experience with thesame class of substance is necessary.15A new method of analysis has been based on the behaviour ofsubstancea towards X-rays. A beam of the monochromatic raysis made to pass through a glass tube containing the powderedmaterial, and the resulting diffraction patterns are photographed.The method can be used for the qualitative analysis of mixtures,and in some casw for the approximate estimation of their con-stituents .I6Gas Analysis.Certain precautions should be taken when using cupric oxide forcombustions in gas analysis.The temperature must not ba allowedto fall below red heat, or the activity of the reduced copper will bediminished. Nitrogen prepared from air by deoxidation withphosphorus invariably contains some phosphorus vapour, and there-fore when great accuracy is required, pyrogallate should be usedfor absorbing the oxygen.1711 C. Cheneveau and R. Audubert, Compt. rend., 1919,168, 766 ; A., ii, 205.12 S. J. Lewis, T., 1919, 115, 312.18 J. C. Philip, F. Stanley, F. Twyman and F. Simeon, H. Main, A. Homer,14 C. E.Famitt, T., 1919, 115, 790.l6 Ibid., 801.16 A. W. Hall, J . Amer. Chern. SOC., 1919, 41, 1168; A., ii, 470.1 7 E. Ott, J. GmbebucTbt., 1919, 62, 89; A., 1920, ii, 62.REP.-VOL. XVI. PA. E. Berry, J . SOC. Chem. Id., 1919,38,139-146 T130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The use of soda-asbestos as an absorbent for carbon dioxide hasthe advantage that it acts as its own drying agent, whilst it enablesa more simple form of apparatus to be used. The mixture willabsorb upwards of 10 per cent. of its weight of carbon dioxide, andis particularly suitable for the estimation of carbon in steel.l*A study of the conditions of absorption of oxygen by sodiumpyrogallate has shown that the rate of absorption increases withthe dilution of the sodium hydroxide solution, but is always pro-portional t o the concentration of pyrogallol in the solution.Carbonmonoxide is evolved from all sodium pyrogallate solutions of lowerspecific gravity than 1.30, and in all cases when the concentrationof the oxygen under examination exceeds 95 per cent. A formulais given for the preparation of a rapid absorbent evolving theminimum amount of carbon rnonoxide.19Oxygen in the upper atmosphere may be estimated by means ofa simple form of apparatus in which the difference of pressure ismeasured, with the aid of a barometer tube and micrometer screw,before and after deoxidising the air with phosphorus.20A sensitive t w t for ozone is based on the fact that a trace ofit immediately destroys the fluorescence of an extremely dilutesolution of fluorescein, whereas much larger amountij of nitrousvapour, chlorine, or carbon monoxide are required. As little as10-9 gram of ozone may thus be detected and estimated, so thatthe reaction is much more sensitive than the starch iodide test.21Carbon monoxide in hydrogen may be estimated by selectiveoxidation in the presence of a suitable catalyst, and an instrumentbased on this principle has been devised.22 The reaction is notquite complete between 150° and 400°, whilst the preferentialoxidation is reduced by increasing the temperature.Above 400°,the combustion of the hydrogen is more rapid than that of thecarbon monoxide.23Carbon monoxide may also be estimated by oxidation t o carbondioxide by means of iodine pentoxide under specified conditions.In the case of gases containing more than 0.2 per cent.of carbonmonoxide, and where the accuracy need not exceed 0.2 per cent., amodification of the apparatus previously described 24 may be used.2618 L. J. Rogers, Canadian Chem. J., 1919, 3, 122.1* GI. W. Jones and M. H. Meighan, J. I&. Eng. Chem., 1919, 11, 311;20 F. W. Aston, P., 1919, 115, 472.22 E. K. Rideal and H. 8. Taylor, ArzaZy&, 1919, 44, 89 ; A., ii, 200.23 E. I(. Rideal, IT., 1919, 115, 993.24 T., 1914, 105, 1996.26 J. I. Graham, 3. Soo. Ohem. Ind., 1919, 88, lor; A., ii, 117.A., ii, 240.L. Bonoist, Compt. rend., 1919, 168, 012 ; A., ii, 198ANALYTICAL CHEMISTRY. 131Titration with potassium iodate in the presence of hydrochloricacid affords an accurate method of estimating sulphites and sulphurdioxide in gaseous mixtures.An addition of glycerol prevents lossfrom oxidation of the sulphite by dissolved air, and does notinterfere with the subsequent titration.26A reaction capable of detecting 1 part of carbonyl chloride in10,000 parts of air depends on the separation of diphenylcarbamidewhen the air is passed through an aqueous solution of aniline,COC1, + 4C,H,*NH, = CO(NH*C6H5)2 + 2C6H5*NH,,Hc1.The precipitate may be dissolved off the filter with alcohol, thesolution evaporat?ed, and the residue dried a t 60° and weighed, orammonia may be separated, as in Kjeldahl’s process, and Btimatedcolorimetrically.27For the estimation of gasoline in natural gas, a measuredquantity of the gas is passed through drying tubes and then throughan absorption vessel immersed in a mixture of ether and solidcarbon dioxide in a drying tube.The vessel is then sealed and thecondensed liquid weighed.28 I n another method, a solid material,such as charcoal, is used as the absorbent for the gasoline vapours.29A method of estimating acetylene in admixture with ethylene o rother hydrocarbons has been based on the observation ofChavastelon,30 that when acetylene is passed into a neutral solutionof silver nitrate, the liquid becomes acid in accordance with theequation : C,H, + SAgNO, = C,Rg,,AgNO, + 2HNO,, so that bytitrating the liberated nitrio acid, a measure of the acetylene isobtained.31A gricultural Analysis.Few new analytical processes have been published in connexionwith agricultural chemisbry during the past year, and .most of thecommunications have dealt with methods previously known.In estimating carbon in soils by the wet combustion method,absorption of the carbon dioxide by barium hydroxide, as inSchollenberger’s method,32 has the drawback that carbon dioxide isreadily absorbed from the air, whilst absorption in potassium hydr-26 P.Haller, J . SOC. Chem. Ind., 1919, 38, 5 2 ~ ; A., ii, 198.27 A. Illing and R. Schtnutz, Compt. rend., 1919, 168, 773, 891 ; A.. ii, 244.28 K. Kling, Metan, 1917, 1, 3.49 G. G. Oberfell, S. D. Shinkle, and S. B. Meserve, J. Ind. Eng. Chem.,8o Oompt. Tend., 1897, 124, 1364; A., 1897, i, 545.1919, 11, 197.W.H.Ross and H. L. Trumbull, J . Amer. Chem. SOC., 1919, 41, 1180 ;A., ii, 482.8a J. Ind. Eng. Chem., 1916, 8, 427: A., 1916, ii, 395.s 132 AJYNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.oxide solution is tedious. A simple modification, in which thecarbon dioxide is absorbed in a soda-lime tube, is rapid and givesaccurate results.%The total nitrogen in soil extracts cannot be accurately estimatedby the direct application of the Kjeldahl process when as mucha.s 10 per cent. of the nitrogen is in t.he form of nitrates, and insuch cases a process of reduction must be used.34 For example, theextract may be rendered slightly alkaline with sodium hydroxidea d treated with Devada's alloy prior to the digestion withsulphuric acid in the Kjeldahl process.35 I n another method, thedifferent forms of nitrogen are estimated by using Kjeldahl'smethod for the total nitrogen other than nitric nitrogen, distillingthe ammoniacal nitrogen from the original extract with magnesiumoxide, and reducing the residual liquid with magnesium chlorideand copper-magnesium alloy to obtain nitric and nitrous nitrogen.Finally, the ammonia and nitrous nitrogen are removed fromanother portion by boiling with dextrose, ferrous sulphate, andsodium carbonate, and the solution is again reduced with t'he alloyto obtain the nitrio nitrogen.36Nitrates in soil may be quantitatively extracted with cold waterunder specified conditions, and may then be accurately estimatedin the extract by the phenoldisulphonic acid method, provided thetemperature be kept below that at which nitrates and chloridesreact with the dilute sulphuric acid.An addition of calciumhydroxide to the soil prior to the extraction will prevent soilscontaining organic matter from yielding coloured extracts.37For the estimation of organic phoBphorus in soils, i t is recom-mended that calcium should first be extracted with 1 per cent.hydrochloric acid, which is subsequently removed by means ofaqueous carbon dioxide solution, after which the organic phosphorusis extracted with 4 to 6 per centl. ammonium hydroxide solutionand the extract filtered through a layer of the soil. No advantageis gained by the use of potassium or sodium hydroxide for theex t r actqi on .3*The solubility of rock phosphates in 0.2 per cent.citric acidsolution is about the same as the solubility in ammonium citratesolution, and although the latter does not extract the whole of the88 D. D. Waynick, J . Ind. Eng. Chem., 1919, 11; 634; A., c, 371.'4 R. S . Snyder, Soil Sci., 1918, 6, 487; A,, ii, 296.8 5 B. S. Davisson and J. T. Parsons, J. Ind. Eng. Chem., 1919, 11, 306 ;86 T. Pfeiffer and W. Simmermacher, Landw. Versuchs-Stat, 1918, 93, 66 ;8 7 H. A. Noyes, J . Ind. Eng. Chem., 1919,11, 213; A., ii, 199.88 C. J. Schollenberger, Soil Sci., 1918, 6, 366 ; A., 3, 168.A., ii, 242.A,, ii, 296ANALYTICAL CHEMISTRY. 133available phosphorus, it is preferable to citric acid as a method ofjudging the effect of any special treatment of the phosphat'e.Thesolubility increases with the strength of the citric acid, whilstdilute nitric acid is still less suitable for the extraction.39An experimental study of the methods of preparing superphos-phates has shown that in the case of commercial products contain-ing about 1 2 to 20 per cent. of phosphoria oxide and 10 to 20 percent. of water there is a system with a fairly high proportion ofphosphoric oxide and a very low proportion of water. I n estdm-ating frele phosphoric acid in such products, it is necessary t o useanhydrous ether for the extraction, since water, alcohol, or ordinaryether causm more or less hydrolysis of the monocalcium phosphate,according t'o the amount of water originally present .40The value of agricultural lime, has been shown by practical teststo depend rather on its power of neutralising acids than on theproportions of calcium oxide, magneBium oxide, o r carbon dioxidepresent.The neutralisation power may be estimated by boilingthe lime with standard acid, titrating the excess of acid with alkali,and expressing the results in terms of calcium carbonate.41 Anelectrical method of estimating the lime requirement of soils hasalso been devised. The soil is shaken with distilled water and(another portion) with calcium hydrogen carbonate sdution forthree hours, and the electrical resistance of each liquid determinedbefore and after shaking with the soil. The ratio between the tworesults affords a measure of the acidity or alkalinity of the ~0il.42Organic Analysis.Qzm?itatiue.-A new method of separating and identifyingalcohols has been based on their conversion into allophanates, bymeans of the action of cyanic acid gas.The alcohol is thenidentified by the melting point of the recrystallised precipitate, andfurther tests are applied by hydrolysing the allophanate and deter-mining the physical characters of the alcohol. Normal allophanatesare produced by alcohols containing an ethinoid group, terpenicalcohols, except linalool, and cyclic alcohols, except terpifieol. Thepresence of the phenolic group in cyclic alcohols interferes withthe reaxtion, and in such case3 a preliminary esterification is neces-sary before applying the test.43Ann. Report, 1917, 161.am J. A. Stenius, J . Ind. Eng. Chem., 1919, 11, 224; A., ii, 199; compareA.Aita, Anndi Chim. App?., 1919, 10, 46 ; A., ii, 25.S . D. Comer, J . Ind. Eng. Chem., 1918, 10, 996.0. J. Lynde, Tram. Roy.80~. Canada, 1918, [iii], 12, 111, 21 ; A , , ii, 376.43 A. mhal, Compt. rend., 1919,168, 946 ; A., ii, 301134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The detection of methyl alcohol in ethyl alcohol by oxidation bformaldehyde is untrustworthy in the presence of higher alcohols,but the oxidation products of the latter may be distinguished bythe fact that they give yellow to reddish-brown colorations withapomorphine and sulphuric acid, whereas formaldehyde gives aviolet coloration with that reagent.44A specific reaction for oxalates has been described, according towhich a red coloration is obtained when the oxalate solution istreated with manganese sulphate solution, acetic acid, and potassiumdichromate or alkali hypochlorite solution.The presence of phos-phoric or hydrofluoric acid does not interfere with the tmt.45The distinctive blue coloration given by thiophen in the indo-phenine reaction is not obtained unless a trace of an oxidisingagent, preferably nitric acid, is present ; otherwise the coloration isgreen.46Compounds containing arsenotungstic and arsenomolybdic com-plexes have been recommended as reagenb for phenolic amineg.They give an intense blue coloration with phenols, purine deriv-atives, and phenolic amines. The arsenotungstic reagents also reactwith hydroxylamine and hydraxine, whilst the arsenotungsto-molybdic reagents also give a coloration with substances, such asaniline, conkaining one amino-group.*'A qualitative test for morphine capable of detecting 1 part in10,000 has been based on its property of yielding dyes on treat-ment with diazonium compounds, such as diazobenzenesulphonicacid. On adding this compound t o an alkaline solution of themorphine salt, colorations ranging from pale to deep red, andchanging to orange on acidification, are obtained.The reactionwill detect morphine in the presence of other alkaloids.48A comparative study of the sensitiveness of different tests forquinine49 has shown that' the fluorescence test with sulphuric acidis capable of detecting 1 part in 100,000, whilst the thalleioquininereaction is ten times less sensitive.In the latter te&, it isadvantageous t o replace chlorine by bromine. Reference is madeto a sensitive reaction which has been based on the turbidity givenby a solution containing as little as 1 part of quinine in 200,000with a reagent consisting of potassium iodide and mercuric chloridein acetic acid.5044 H. Wolff, Chern. Zeit., 1919, 43, 5 5 8 ; A., ii, 482.45 H. Caron and D. Requet, Ann. Chim. anal., 1919, [ii), 1, 26; A,, ii,413 E. wray, J . SOC. Chem. Ind., 1919, 88, 83r ; A., ii, 204.47 I,. Guglialmelli, Anal. Soc. Quim. Argentina, 1918, 6, 186 ; A,, ii, 87.48 L. Lautenschlager, Arch. Pharm., 1919, 257, 13 ; A., i, 344.4 9 H. Salomon, Ber. Deut. p h m . Get?., 1918, 28, 273; A, ii, 87.5 0 G. Giemsa and J.Halberkann, Deutsch. Ned. Woch., 1917, No, 48.438ANALYTICAL CHEMISTRY. 135Aconitine, both crystalline and amorphous, givm a violet color-ation with phosphoric acid solution containing 4 per cent. of sodiummolybdate. Aspidospermine and veratrine also give violet color-ations with the reagent, but may be distinguished from aconitineby other tests. The coloration is not given by other alkaloids.The deep red coloration given by digitalin on treatment withpicric acid and potasshm hydroxide serves to distinguish it fromcertain closely allied glucosides, some of which give an orangecoloration, whilst others do not give any coloration in the test.Peptones also give a similar red coloration. It is suggested thatthe reaction may be due to the presence of a carbonyl group linkeddirectly to a carbon atom.51Quantitative.-In estimating halogens in organic compounds bycatalytic reduction in the presence of palladium, the use of hydr-azine is suggested as being preferable to purified hydrogen, beingdecomposed by the catalyst into nitrogen and hydrogen.Afterthe decomposition, the catalyst is separated by filtration, and thehalogen estimated in the filtrate.52A modification of Young and Swain's method of eatimating nitro-groups by means of stannous chloride53 givea trustworthy resultswith numerous nitro-aromatic compounds. The substance is mixedwith alcohol, the air in the flask displaced with carbon dioxide, anexcess of standard stannous chloride solution added, and the flaskheated on the water-bath while a current of carbon dioxide ispassed through it.Finally, the excess of stannous chloride istitrated with standard iodine solution.64A rapid method of estimating methoxyl groups by the methyliodide process embodies the same principle as that of Kirpal andBuhn,55 but instead of evaporating the excess of pyridine, the liquidis diluted with water, acidified with nitric acid, a measured quantityof silver nitrate added, and the excess titrated with thiocyanabPAn analogous method has been devised for estimating methoxylgroups containing sulphur, in which the methyl iodide and hydrogensulphide are absorbed by pyridine containing silver nitrate, andthe silver sulphide separated before. completing the estimation.57The presence of water interferes with the accurate estimation ofether in alcohol from the specific gravity of the liquid. This isobviated by fractional distillation and determining the specificH. Baljet, Pharm.Weekblad, 1918, 55, 457; A., ii, 438.aa M. Busch, Zeitsch. angew. Chem., 1918, 31, 232.53 J . Amer. Chem. SOC., 1897, 19, 812; A., 1898, ii, 186.J. G. F . Druce, Chem. News, 1919,118, 133; A., ii, 199.55 Ber., 1914, 47, 1084; A., 1914, ii, 497.66 J. T. Hewitt and W. J. Jones, T., 1919,115, 193.6' M. Hijnig, Monatsh., 1919, 39, 871 ; A., ii, 171136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.gravity of the alcohol before and after distillation of a first fractioncontaining all the et’her. The amount of the latter is then obtainedby means of a formula.68The possibilities and limitations of Duclaux’s method of estim-ating homologous acids by distillation with steam have been studiedand the results compared with those previously obtained.69 Thedegree of concentration does not have any pronounced influence onthe results, except to some extent in the case of butyric acid, Thegeneral conclusion drawn from test distillations was that DucIaux’smethod will enable the amounts of two fatty acids in a mixture tobe estimated within about L per cent.of the true quantity, or, inthe case of three acids, within about 5 per cent. by a single dis-tillat.ion, or about 1 per cent. by fractional distillation.60 I n thisconnexion, mention may be made of a new type of still-head ofspecial construction, by the use of which the distillation slows downwhen the limit for each pure constituent in a mixture is reached,so that it is possible with the aid of this appliance to separatebenzene, toluene, and xylem by direlct distillation.61Cyanides, cyanates, and bromides may be estimated when insolution together by titrating the liquid with silver nitrate. Titra-tion in alkaline solution gives the amount of cyanide, whilst thethree compounds together are obtained by titration in the solutionneutralised with acetic acid, and the cyanide and bromide togetherby titration in the solution acidified with nitric acid.62A new method of estimating oxalic acid is based on the fact that,when heated with acetic anhydride, it is quantitatively decomposed,so that the volume of carbon dioxide liberated affords a measureof the oxalic acid originally present.Formic acid is the only otherorganic acid of common occurrence which undergoes a similardecomposition.63For the estimation of soluble starch in the presence of starchand the products of its hydrolysis, advantage has been taken of thefact that the blue iodine compound with soluble starch is insolublein a semi-saturated solution of ammonium sulphate. The pre-cipitate is separated and washed with the aid of centrifugal form,dissolved in water and, after removal of the iodine, saccharifid,and the resulting dextrose estimated polarimetrically.64There have been a few additions to the methods of analysingH. E. Cox, Analyst, 1919, M, 26; A., ii, 83.s9 H.D. Richmond, ibh?, 1917, 42, 125; A., 1917, i, 316.6o Ibid., 1919, a, 255; A,, ii, 435.61 S. F. Dufton, J . SOC. Ohem. Ind., 1919, 38, 4 5 ~ ; A., ii, 136.6a G. Velardi, Boll. chim. .farm., 1919, 58, 241 ; A., ii, 483.6J H. Krause, Ber., 1919, 52, 426 ; A., ii, 203.64 J. C. Small, J . Amer. Chem. SOC., 1919, 41, 107; A., ii, 172ANALYTICAL CHEMISTRY. 137sugars. It has been shown that a cupric sodium hydroxide reagentcan replace Fehling’s solution, over which it has the advantage ofnot becoming turbid when boiled .65I n order t o obtain concordant results in the method of titratingsugars with copper phosphate solution, the exact details of pre-paring the salt mixture must be followed. The possibility of thereduction of the copper sulphate in the method of Folin andMcEllroy66 may be prevented by rendering the solution alkalinebefore adding the thiocyanate, and a modified process embodyingthis precaution is described.67For the estimation of thiophen in benzene, good results areobtained by a modification of a method in which Denighs’ reagent(basic mercuric sulphate) is shaken with the benzene, and the pre-cipitated compound of thiophen dried and weighed.The use ofPaolini and Silbermann’s reagent (basic mercuric acetate) is alsotrustworthy, the rmulting precipitate, SC4(HgC,H,0,),, beingwashed with cold water, dried, and weighed.68Sulphonyl chlorides of aromatic substances may be estimated bymixing them with water, neutralising free acids with sodium hydr-oxide, boiling them under a reflux condenser with excess of sodiumhydroxide solution, and titrating the excess.The amount ofsulphonyl chloride corresponds with the quantity of alkali used forthe hydrolysis.69A convenient method of estimating phenacetin and otherpaminophenol derivatives has been based on their reaction withhydrochloric acid and sodium hypochlorite t o form p-benzoquinone-chloroimide, HO*C,H,*NH,,HCl+ 4Cl= 4HC1+ O:C,H,:NCl. Afterremoving the excess of chlorine by a current of air, potassium iodideis added, and the liberated iodine titrated. Four atoms of iodineare liberated in this reaction, and the paminophenol isregenerated -70A general method of estimating alkaloids is to precipitate thealkaloid from an acidified aqueous solution with alkali, to mix itinto a soft paste with plaster of Paris, and t,o extract the mass withchloroform.The alkaloid is then removed from the extract bymeans of standard acid, the excess of which is subsequentlytitrated .7166 E. Justin-Mueller, J . Pharm. Chim., 1919, [vii], 19, 18; A., ii, 202.66 J . BioZ. Chem., 1918, 33, 513 ; A., 1918, ii, 207.67 0. Folin and E. C. Peck, ibid., 1919, 38, 287 ; A., ii, 354.68 P, E. Spielmann and S. P. Schotz, J. SOC. Chem. Id., 1919, 38, 1 8 8 ~ ;A., ii, 433.F. Neitzel, Chem. Zeit., 1919, 43, 500 ; A., ii, 482.‘O A. D. Powell, Analyst, 1919, 44, 2 2 ; A., ii, 86.Rapp, Apoth. Zeit., 1918, 33, 463.P138 BNNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.From a. comparative study of the methods of estimatingmorphine, a.method has been devised in which the alkaloid isextracted by means of a mixture of two parts of chloroform andone part of alcohol. Modifications for use in the cases of prepara-tions of morphine and of opium are also given.72Experimenh have been made which show that berberine may beaccurately estimated in an alcoholic extract of Hydrastis canadensisby precipitation with Mayer’s reagent (mercuric chloride andpotassium iodide), and subsequent conversion into berberinepicrolonate, which is dried at looo and weighe(d.73Znorganic Analysis.&ualitative.-Several new indicators have been described in thecourse of the year. Magenta and other colouring matters of thetriphenylmethane group when decolorised with sulphur dioxidemay be used as sensitive indicators for the detection of alkalinity,especially in water.74 An aqueous decoction of red beetroot is asensitive indicator for both weak and strong acids.The colour ischanged to yellow by alkalis, but is restored by sulphuric acid in adilution of 1 : lO,OOO.75The red iodotannio reaction76 is much more sensitive than thestarch-iodine reaction, but there must be no excem of either iodineor tannin, or the red coloration will not appear. On the otherhand, it has the drawback that potassium iodide interferes withit.?7 The presence of salts, and especially of potassium iodide,increases the sensitiveness of the starch-iodine reaction, whilstraising the temperature, or the presence of organic substances, suchm alcohol, renders it less sensitive.78 A convenient method of pre-paring starch indicator has been based on the property of starch todissolve in 1 per cent.salicylic acid solution. The preparationkeeps well, remains clear, and when diluted gives a deep bluecoloration with iodine.79The influence of the quality of, and previous treatment of, thepaper on the reactions obtained with coloured test papers has beenA. Tingle, Amer. J . Pharm., 1918, 90, 689, 788, 851 ; A., ii, 87, 88, 175.78 R. Wasicky and M. Joachimowitz, Arch. Pharm., 1919, 255, 497 ; A.,74 I. Guareschi, Buzzetta, 1919, 49, i, 115 ; A., ii, 348.7 5 M. Chauvierre, Bull. SOC. chim., 1919, [iv], 25, 118 ; A., ii, 196.78 D. E. Tsakdotos and D. Dalmas, ibid., 1918, [iv], 23, 391 ; A., 1918,7 7 Ibid., 1919, [iv], 25, 80; A., ii, 169.78 I.M. Kolthoff, Pharm. Weekblud, 1919, 56, 391 ; A., ii, 259.5s G. J. Hough, J . Id. Eng. Chem., 1919, 11, 767.i , 564.ii, 454 ; Ann. Report, 1918, 132ANALYTICAL CHEMISTRY. 139studied, and it has been shown that sized papers are less sensitivethan unsized, although they give a sharper reaction.80A new systematic scheme for the detection and approximateestimation of the acids of Group I has been devised, and has beenshown by test analyses to be trustworthy.81Turning t o the reactions for individual substances, it has beenfound that o-tolidine is a delicate reagent f o r gold, being capableof detecting 1 part in 20 millions. Ferric salts, ruthenium, osmicacid, and vanadium salts also give a yellow coloration, but mostother common metals do not give this reaction.In the presence1of copper, the coloration is green instead of yellow.82Mercury in organic or inorganic compounds may be detected bytreating the solution or suspension of the substance with nitricacid, exceas of ferrous sulphate, and concentrated sulphuric acid sothat the liquids do not mix. I n the presence of mercury, a reddish-violet ring is formed, and the usual brown ring produced by thenitric acid does not develop until later.83A sensitive reaction for manganese is based on the red colorationproduced when the solution is treated with potassium oxalate,acetic acid, and potassium hypochlorite,s* but this test is not sosensitive as that with lead peroxide and nitric acid, although i tmay be used conversely for detecting traces of oxalic acid.85The difference in behaviour on treatment, with excws of mercuricchloride solution affords a means of distinguishing between thesodium salts of different sulphur acids.No precipitate is given bythe sulphate, sulphite, or hydrogen sulphite, whereas the sulphide,thiosulphate, and polythionates yield precipitates. Further differ-entiation is based on the reactions towards methyl-orange and onthe behaviour towards iodine.86Several new reagents for micro-chemical analysis have beendescribed. For example, quinosol (the potassium salt of 8-hydroxy-quinoline-5-sulphonic acid) and superol (2-hydroxyquinolinesulphate) yield distinctive crystalline precipitates with arsenates,barium, mercurous salts, lead, tin, iron (ferrous), and silver.87Characteristic crystals of lead iodide are obtained by treatingsoluble lead salts with a drop of potassium bromide and of80 I .M. Kolthoff, Pharm. WeekbZad, 1919, 56, 175; A., ii, 518.81 L. J. Curtman and D. Hart, Chem. News, 1919,119, 25, 37 ; A., ii, 425.82 W. B. Pollard, Analyst, 1919, 44, 94; A., ii, 201.8s A. Abelmam, Pharm. Zentr.-h., 1919, 60, 247; A., ii, 428.84 H. Caron and D. Raquet, Ann. Chim. anal., 1919, [ii], 1, 174 ; A., ii,85 D. H. Wester, Phrm. Weekblad, 1919, 56, 1289; A., ii, 479.86 A. Sander, Chem. Zeit., 1919, 43, 173; A., ii, 241.87 N. Schoorl, Phamn. Weekblad, 1919, 56, 325; 'A., ii, 201.351.I?* 140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.potassium iodide solution .88 A microscopic reaction, which is givenby most bismuth compounds, is the formation of colourless, crystal-line salts on treatment with dilute hydrochloric acid and hexa-methylenetetramine solution.*g&mntitative.-Arsenious oxide may be used as a t'rustworthystandard for iodometry.90 The purity of the arsenious oxide maybe conveniently estimated by measuring the electrical conductivityof a saturated solution. The most common impurity is arsenicoxide, which may be estimated by determining the reaction of thesolution t o methyl-orange and methyl-retd.91 I n the idiometricestimation of arsenic acid, the re'action,AqO, + 4HI = As2O3 + 21, + 2H20,proceeds from left to right only in strongly acid solution.92Attention has been drawn to several sources of error, such asatmospheric oxidation, in the estimation of sulphurous acid andsulphites by means of iodine.I n order to obtain accurate results,the sulphurous acid solution should be added to the iodine solu-tion.93 The reaction between iodine and thiosulphates varies withthe acidity or alkalinity of the solution. I n slightly alkaline solu-tion, part of the thiosulphate is converted directly to sulphate, andin strongly alkaline solution the whole of i t is thus converted.94For the direct iodometric estimation of hydrogen peroxide, afew drops of ammonium molybdate should be added with thepotassium iodide and acid to act as catalyst, and the liberatediodine immediately titrated.95Hypophosphites in sulphuric acid solution are oxidised to phos-phorous acid by iodine, and on then adding excess of sodiumhydrogen carbonate, the oxidation is continued to phosphoric acid.A method of estimating hypophosphites and phosphites is basedon these reactions.96 A chromate may be directly estimated by aniodometric method, but it is necessary to have sufficient acid pre-sent to inhibit a side reaction.97 I n using potassium dichromatefor iodometric estimations, precautions must be taken to eliminateerrors due to impurities in the dichromate and to atmosphericoxidation.9888 G.Denigbs, J . Pha~m. Chim., 1919, [vii], 20, 159 ; A., ii, 523.89 Idem, Ann. Chim. anal., 1919, [ii], 1, 213; A., ii, 431.90 R. M. Chapin, J . Amer. Chem. Soc., 1919, 41, 351 ; A., ii, 196.91 I.M. Kolthoff, Pltam. Weekblad, 1919, 56, 621 ; A., ii, 522.92 Ibid., 1322 ; A., ii, 427. 9a Ibid., 1366; A,, ii. 473.94 Ibid., 572 ; A . , ii, 365. 95 Ibid., 949 ; A., ii, 370.96 Boyer and Bauzil, J . Pharm. Chim., 1918, [vii], 18, 321 ; A., ii, 77.97 I. M. Kolthoff and E. H. Vogelenzang, Pharm. Weekblad, 1919, 56. 514;D* C. R. McCrosky, J . Amer. Chem. Xoc., 1918,40, 1662 ; A., ii, 31.A., ii, 300ANALYTICAL CHEMISTRY. 141The abnormally high results obtained when sodium arsenate isused for titrating potassium permanganate in the presence of nitricacid are probably due to the occurrence of complicated reactions inthe course of. the titration.99A volumetric method of estimating sulphurous acid has beenbased on the oxidation of the sulphur dioxide by means of hydrogenperoxide, and titration of the excess of hydrogen peroxide by meansof potassium permanganate solution, standardised against purehydrogen peroxide under similar conditions.1For the volumetric estimatJon of sulphates, a method sufficientlyaccurate for technical purposes has been based on the reactionbetween certain soluble sulphates and freshly precipitated bariumoxalate, and titration of the resulting soluble oxalate with per-manganate solution.2An oxidimetric method has been devised to obviate the sourcesof error in the ordinary methods of estimating nitrous acid andnitrites.The nitrite solution is run into excess of acidified perman-ganate solution, the excess reduced by means of ferrous sulphate,and the excess of the latter titrated with standard permanganatesolution.Chlorides or bromides in small quantity do not interferewith the process.3 The influence of fluorides on the oxidimetricestimation of nitrites may be eliminated by combining an iodo-metric method with the oxidimetric method.4A cyanometric method of estimating silver and halogens has beenbased on the fact that silver iodide in cold, very dilute ammoniacalsolution forms only a turbidity unless a large excess of potassiumiodide was added. On adding potassium cyanide, the turbiditydisappe'ars when sufficient CN' has been added to form Ag(CN),'.Halogens are estimated indirectly by adding excess of silver nitrate,removing the precipitate, and titrating the excess of silver.5The behaviour of various metallic f errocyanides towards chlorineand bromine has been studied, and it has been shown that nickeland bismuth are quantitatively precipitated as f errocyanide.6The conditions under which zirconium is quantitatively precipit'atedas phosphate have been investigated; the separation is com-plete in the presence of 2 to 20 per cent.of sulphuric acid.The addition of a small quantit'y of ammonium nitrate to the09 A. Bose, Chem. News, 1918, 117, 369 : A., ii, 36.1 T, J. I. Craig, J . SOC. Chem. Ind., 1919, 38, 9 6 ~ ; A., ii, 241.a A. C. D. Rivet& Chem. News, 1919, 118, 253; A., ii, 295.J. S . Laird and T. C. Simpson, J . Amer. Chem. SOC., 191 9, 41, 624 ; A , ,I. Rellucci, Uazzetla, 1919, 49, i, 209 : A., ii, 476.6 J.Eggert and L. Zepfel, Ber., 1919, 52, [B], 1177 ; A., ii, 351. ' I?. F. Werner, Zeit8ch. anal. Chem., 1919, 58, 23; A., i, 313.ii, 242142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.washing water prevents hydrolysis of the precipihb, which willthen, on ignition, yield zirconium pyrophosphate.7 The composi-tion of the precipitate approximates more closely to the normalphosphate as the acidity of the solution increases.8 The methodeffech a separation of zirconium from aluminium, iron, andchromium.9A simple method of estimating carbon dioxide in carbonates isto treat the substance with acid in a tmtrtube placed in a suctionflask, and to absorb the carbon dioxide in standard barium hydr-oxide solution. The resulting barium carbonab is separated, andthe excess of alkali in the filtrate titrated.10Perchlorates may be estimated in the presence of &lorate by amethod based on the fact that only the perchlorates are reduced bya hot acid solution of titanium chloride, the excess of which issubsequently titrated with ferric chloride solution .I1An accurate method of estimating arsenic acid is by reductionwith potassium thiocyanate, and gravimetric estimation of thearsenic as sulphide.12A combination of the Roee-Finkener and Eschka methods affordsa rapid and accurate means of estimating mercury in most of itscompounds.The powdered substance is heated with iron powderin a porcelain crucible covered with a gold or silver crucible,through which circulatm cold water, and the condensed mercury.iswashed with alcohol and weighed.l3The fact that gallium chloride volatilises at a relatively lowtemperature enables gallium to be separated from other metals thechlorides of which are less ~o1atile.l~Molybdenum may be estimated by precipitation as sulphide, andconversion of the sulphide into molybdenum trioxide, but thetemperature should not be allowed to exceed about 425O, or themolybdenum trioxidei will ~ub1ime.l~A study of the methods of estimating calcium has shown thatprecipitation as oxalate from a solution acidified with acetic acidin the presence of excess of ammonium chloride gives accurate' G. E. F. Lundell and H. B. Knowles, J. Arner. Chem. Soc., 1919, 41,a G. Steiger, J . Wmhington Acad. Sci., 1918, 8, 637 ; A., ii, 82.1801 ; A., 1920, ii, 60.P. Nicolardot and A.Reglade, Compt. rend., 1919,168, 348 ; A,, ii, 171.J. G. Williams, Chem. News, 1919, 119, 8 ; A., ii, 348.lo D. D. van Slyke, J . Biol. Chem., 1918, 36, 351 ; A., ii, 78.l2 L. W. Winkler, Zeitsch. acngew. Chem., 1919,32, I, 122 ; A,, ii, 243.l8 S. Pica de Rubies, Awl. Pis. Quim, 1918, 16, 661 ; A., ii, 80.'l4 T. W. Richa.rds, W. M. Craig, and J. Sameshirna, J . Amer. Chem. Soc.,Is K. Wolf, Zeitsch. angew. Chem., 1918, 31, I, 140; A., ii, 121.1919, 41, 131 ; A., ii, 157ANALYTICAL UHEMISTRY. 143results. The precipitate is best weighed as oxalate.16 Good resultsmay also be obtained by precipitating the calcium from anammoniacal solution and weighing it as oxide.17Electrochemical Analysis.There have been several important contributions to the methodsof electrometric titration during the year.A special form ofpotentiometer has been devised for determining the end-pointsharply in such titrations, a calomel electrode being used.18 Bymeans of this instrument, ferrous iron may be accurately estimatedby .titration with potassium dichromate or permanganate, andferrio iron and potassium dichromate by titration with stannouschloride. Advantages of the method are that extremely dilutesolutions may be used, that the time is greatly reduced, and thatsome of the conditions may vary within fairly wide limits.19It has been shown in titrating ferrous salts with potassium per-manganate solution in acid solution that the conductivity remainsfairly constant throughout the titration, but that i f insufficientacid is present, the conductivity steadily falls until the oxidationis complete before becoming constant, the end-point being indicatedby a sharp change in the direction of the curve.On the otherhand, in titrating manganous salts with permanganate, theelectrical conductivity increases until the oxidation is complete, andthen becomes constant.20When potassium dichromate is used for titrating ferrous ironin acid solution, the E.M.F. increases rapidly towards the end-point, which may be obtained from the middle point of the curvesection. Titration with potassium bromate solution also givesgood results. When potassium permanganate is used, the E.M.F.is increased by stirring the solution during the titration.21From a study of the methods of estimating sulphates, chlorides,calcium, and magnesium in relatively weak solution by measure-ment of the electrical conductivity, it has been found that downto a certain limit of dilution the results are accurate to withinabout 1 per cent., but that beyond that limit smooth curves areobtained, and the results are no longer trustworthy.22Ferrocyanides may be estimated by slow titration with potassiuml6 L.W. Winkler, Zea'tsch. angew. Chern., 1918, 31, I, 187, 203 ; A., E, 34.l7 E. Canals, Bull. SOC. chim., 1918, [iv], 23, 422 ; A., ii, 34.l9 J. C. Hostetter and H. S. Roberts, ibid., 1337 ; A,, ii, 480.2o V. Villumbrales, Anal. Fh. Quim., 1919, 17, 100; A., ii, 299.I.M. Kolthoff, Ohem. Weekblad, 1919, 16, 460 ; A., ii, 362.z2 G. A. Freak, T., 1919, 115, 66.H. S. Roberts, J . Amer. Chem. SOC., 1919, 41, 1358; A,, ii, 471144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.permanganate in acid solution, the end-point being taken as thegreatest change in potential corresponding with the addition ofequal amounts of potassium pelrmanganate solution. Ferricyanidesor chlorida in moderate amount do not interfere with the estim-ation, but salts which yield precipit'ates with either ferro- or ferri-cyanides must not be present.%A method of estimating iodides by measurement of the con-ductivity depends on the oxidation of the iodide by means ofpotassium iodate solution :51' + 10,' + 6H' = 3H20 + 31,.The mixture is titrated with hydrochloric acid, the conductivitybeing measured after each addition, until a rapid increase is shown,the end-point being found by reference to the curve.The methodis applicable in the presence of bromides, for the oxidation ofwhich a higher temperature and concentration is required.24Small quantities of vanadium in steel may be estimated bydissolving the sample in nitrio acid and oxidising the vanadiumwith nitric acid under specified conditions, which leave chromiccompounds unaltered. The solution is then cooled and titratedby the elelctrometrio method.25 By a modification of the methodthe chromium may also be estimated.26A rapid method of estimating carbon in steel has been based onthe absorption of the carbon dioxide, obtained by direct combus-tion, in barium hydroxide solution and measuring the change inthe electrical conductivity of the solution caused by the precipita-tion of barium ions.The construction of a nomographic chart isdescribed, by means of which the percentages of carbon may beread with an error of less than 0-005.27Experiments have shown that Pb" may be separated fromCr"' by electrolytic precipitation as lead peroxide under certainspecifia conditions as to the proportions of the two metals in thesolution, etc.28Chlorine, bromine, or iodine may be electrolytically estimatedby an indirect method in which the halogen is precipitated it5 asilver salt, which is dissolved in alkaline potassium cyanide solu-G. L. Kelley and R.T. Bohn, J . Amer. Chem. SOC., 1919,41, 1776.a4 I. M. Kolthoff, Chem. Weekblad, 1919, 16, 926 ; A., ii, 370.85 G. L. Kelley, J. R. Adams, and J. A. Wiley, J . Ind. Eng. Chem., 1917,9,a6 G. L. Kelley, J. A. Wiley, R. T. Bohn, and W. C. Wright, ibid., 1919,27 J . R. Cain and L. Q. Maxwell, ibid., 852 ; A., ii, 476.2* J. Milbauer and J. Setlik, J . pr. Chem., 1919, [ii], 99, 86; A., ii, 372,780 ; A., 1917, ii, 512.11, 632; A., ii, 431ANALYTICAL CHEMISTRY. 145tion, and the latter electrolysed with a nickel-plated oopperelectrode and a rotating iron anode.29Water Analysis.A rapid method of estimating the total solids in water, based ona determination of the electrical conductivity, is frequentlyemployed, but when a mean equivalent weight aad conductivity areassumed in the calculations, the results may be very erroneous inthe case of different waters. It is only when the; composition ofthe solution is known that the equivalent conductaivity may becalculated, and tables for reference under such conditions havebeen drawn up.30For extracting and estimating dissolved gases in water, a methodhas been described in which a bulb, from which the air has beenexhausted, is fitted to a large bottle of the water.On turning thetap below the bulb, the gases are extracted from the water, and byplacing the bottle in water a t about 40°, are completely removed.31Attention has been directed to the fact that pure sodiumcarbonate is acid towards a small amount of phenolphthalein andalkaline towards a larger amount. Hence, in titrating carbondioxide in water with sodium carbonate solution, the amount ofindicator used must be proportional to the quantity of sodiumcarbonate. Directions are given for a method embodying thisprecaution.32 I n order to eliminate the influence of ferrous saltswhich may be present, Rochelle salt may be added before titratingthe water with sodium carbonate in the presence of a definitequantity of phenolphthalein.33The interference of chlorides in the edirnation of nitrates inwater by the phenolsulphonic acid method may be eliminated byusing a more dilute solution of the reagent and adding it to thewater prior to evaporation, which is carried out under specifiedconditions."A source of error in the estimation of albuminoid ammonia inwater is the presence of nitrogenous impurities in the potassiumpermanganate, which are only very slowly eliminated on boilingLn E. Lasala, Anal. Fis. Quim., 1919, 17, 86 ; A., ii, 239.I . M . Kolthoff, Chem. Weekblad, 1918, 15, 1160; A,, ii, 76.F. W. Richardson, J . SOC. Chern. Ind., 1919,38, 3 2 ~ ; A., ii, 167.sa R. Czenmy, Zeitsch. anal. Chem., 1919, 58, 1 ; A,, ii, 297.3s H. a u f , Ber. Deut. pham. Qea., 1919, 29, 344 ; A., ii, 297.s4 R. C. Frederick, Analyst, 1919, a, 281 ; A., ii, 371146 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the permanganate solution with alkali. This may cause the resultsfor albuminoid ammonia to be much too high.35A series of experiments to ascertain the velocity of absorptionof chlorine by the same water in varying intervals of time hasshown that the velocity constant usually increases with the timeof contact. The use of colour readings as an index of chlorineabsorption is only trustworthy with a given water under knownconditions. The chlorine absorption does not increase in directproportion with the increase in pollution (as indicated by theoxygen absorption), but shows decreasing acceleration. Experi-ments have indicated that absorption for five minutes would be aseffective for the routine control of chlorination as the use of alonger time interval .36 C. A. MITCHELL.36 E. A. Cooper and J. A. Heward, Biochem. J . , 1919, 13, 25 ; A., ii,'_296.86 A. Wolman and L. H. Endow, J . Ind. Eng. Chem., 1919, ~11, 209 A.,ii, 197

ISSN:0365-6217    

DOI:10.1039/AR9191600127

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.BEFORE reviewing the year’s work, we may record the deaths ofIvar Bang, Ludwig Brieger, Adrian Brown, Emil Fischer, andFranz Rohmann. Bang, who diea suddenly on December llth,1918, in the prime of life, was a Norwegian by birth, a pupil ofHammarsten, and Professor of Medical Chemistry in the Universityof Lund since 1904. He worked on nucleic acids, histones, andimmuno-chemistry, but is best known for his micro-methods forthe determination of sugar and fat in the blood. His publishedworks include ‘‘ Chemie und Biochemie der Lipoide ” (1911), ‘‘ DerBlutzucker ” (19 13), “ Methoden zur Mikrobestimmung einigerBlutbestandteile ’’ (1916), and “ Lehrbuch der Harnanalyse ”(1918). “ Die Nukleinsauren und ihre Verbindungen ’’ was in pre-paration for the series of German biochemical monographs.Brieger, known among biochemists for his work on ptomaines morethan thirty years ago, was since 1900 Director of the Institute ofHydrotherapy of Berlin University.Adrian Brown was Professorof Brewing at Birmingham. To Emil Fischer biochemistry owesa debt greater than that to any other organic chemist of ourgeneration. Rohmann was for many years Ext,raordinary Professorof Physiological Chemistry at Breslau.Among new publications, we may mention “ Medical Science :Abstracts and Reviews,” a monthly journal published by theOxford University Press for the Medical Research Committee inplace of the Medical Supplement t o the “Review of the ForeignPress,” which was issued from January, 1918, to April, 1919.“Medical Science,” started in October, 1919, aims at providing acritical and selective survey of the medical publications of allcountries, and should therefore be of interest t o physiologioalchemists also.During the war, the eighth and ninth volumes ofAbderhalden’s Handbuch der biochemischen Arbeibmethoden ”have appeared. The earlier volumes are now partly out of print,and a second edition is about to appear. The seriea “Die Bio-chemie in Einzeldarstellungen” was continued at the end of 1918by No. 4, ‘(Die Einwirkung von Mikro-organismen auf die Eiweiss-14148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.korper” by Paul Hirsch. This very complete, if somewhat un-critical, compilation deals with acidic as well as with basic decom-position products of proteins ; in particular, the physiologicallyactive arnines, like tyramine and histamine, are fully dealt with.The third monograph of this series, (‘ Uber kunstliche Ernahrungund Vitamine,” by F.Rohmann, was noticed two years ag0.1 Amost valuable “Report on the present state of knowledge concern-ing accessory food factors (vitamines) ” has appeared in the specialreport series of the Medical Research Committee. It is by a com-mittee consisting of F. G. Hopkins (chairman), H. Chick, J. C.Drummond, A. Harden, and E. Mellanby. Second editions ofW. M. Bayliss’s ‘‘ General Physiology ” and of H. Bechhold’s ‘‘ DieKolloide in Biologie und Medizin ” have appeared. (‘ The Natureof Enzyme Actions,” by the former author, has reached its fourthedition, and ‘‘ Practical Physiological Chemistry,” by S.W. Cole,its fifth. The latter book was originally written for students only,but has now been so much revised and enlarged by the addition ofwell-chosen recent methods that it will be found useful in researchlaboratories.Reviewing the year’s work as a whole, we must recognise that,at least as regards publications, we are still in a period of transi-tion. Probably nearly all war problems have1 been abandoned bynow, but in the matter of publication there is a hysteresis. Forinstance, it is only during the present year that the fermentationprocess of manufacturing glycerol from sugar has come to light.As one of its effects on biological chemistry, the war has left anincreased interest in food problems, especially those concerned withaccessory food substances and deficiency diseases.The Radioactivity and Biological Importance of Potassium.The fact that of the dozen or fifteen elements essential to life,potassium2 is the only one which possesses a distinct, if minute,radioactivity, induced H.Zwaardemaker 3 to replace it in Ringer’ssolution by other radioactive elements. Ringer discovered longago that, in order to keep the isolated frog’s heart beating normallyfor a prolonged period, the perfusion fluid must contain potassiumas well as calcium and sodium salts; he also showed that thepotassium may be replaced by an equivalent amount of rubidiumor of cesium, but if these salts were entirely omitted, the heart1 Ann.Report, 1917, 184.3 See ibid., 1909, 266 for references.For a &sum6 of Zwsardemaker’s researches and those of his pupils, seeP f i e r ’ s Archiu, 1918, 173, 28PHYSIOLOGICAL CHEMISTRY. 149soon stops beating. Now rubidium 4 also has a distinctive &activityfar less penetrating than that of potassium. The &radiation ofceesium of very low penetrating power seems to be absorbed soreadily as to escape detection altogether, but it is postulated byZwaardemaker on biological grounds.5 As a preliminary, he andT. P. Feenstra6 calculated the amount of other elements radio-actively equivalent to the potassium in Ringer’s solution.Zwaardemaker and his pupils showed that the frog’s heart con-tinues to beat equally well if a litre of the perfusion fluid con-tains, instead of 100 mg.of potassium chloride, 25 mg. of uranylnitrate, 50 mg. of thorium nitrate, and 0.000005 mg. of radiumbromide, or a minute quantity of niton (about 100 Mache units).This means that a heart which has stopped beating owing to per-fusion with potassium-free Ringer’s solution begins to beat againwhen an equi-radioactive amount of another element is added tothe perfusion fluid. Moreover, a heart may be made to resumepulsation by exposure to &radiation from mesothorium or fromradium a t a distance of 1-2 cm.7The amounts of radioactive elements quoted above refer to frogsin winter; in summer, smaller amounts suffice, and a reduction inthe necessary amount may also be brought about by addingfluorescein or eosin to the perfusion fluid; in eit.her case, the reduc-tion seems to be due to improved adsorption of the radioactiveelement by the endothelium.Ths adsorption of electricallycharged particlm seems also to be the explanat?ion of the followingparadox. The various means of keeping a heart pulsating, orrestoring its beat when it has stopped, may be arranged in twogroups, namely,potassium uraniumrubidiumcaesium&radiationA heart beating under the influence of any one agent will continueto do so if we, switch over to a perfusion fluid containing theappropriate amount of another member of the same group, butis at once stopped by a member of the other group. Thus,rubidium-Ringer’s solution or &radiation will re-start a heartstopped by a Ringer’s solution free from a radioactive element, andsuch a heart will continue to beat if w0 switch over to msium-4 N.Campbell, Proc. Camb. Phil. SOC., 1909, 15, 11 ; A., 1909, ii, 288.Proc. R. Akad. Wetensch. Amsterdam, 1917, 20, 773.Ibid., 1916,19, 99, 341, 633; A., 1917, i, 70, 105, 241.H. Zwaardemaker and J. W. Lely, Arch. Nderbnd. Physiol, 1917, 1, 746150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,Ringer’s solution, for instance, but will stop if we next perfuse itwith a solution containing uranium or any other member of thes m n d group. Conversely, a heart beating under the influence ofa solution containing radium is stopped by ordinary Ringer’ssolution containing potassium. I n order to change over from onegroup t o the other, it is necessary first to wash out the heart witha solution free from radioactive elements ; accordingly, a mixturefrom both groups stops pulsation.Zwaardemaker finds the ex-planation of these paradoxical rmults in the fact that in the firstgroup we are concerned with negatively charged &radiation, inthe second with positively charged a-particles. (In the oase ofradium, which sends out both kinds, a-particles predominate.) Theadsorption of either kind of particle gives the heart the electriccharge which appears to be nece-ssary, but in a mixture of bothkinds the particles with opposite charge neutralise, each other, sothat the requisite electrical condition of the heart does not result,The radioactive ‘( equilibrium,” due to electrical neutralisation,between potassium and uranium is different in summer and inwinter, and is also modified by fluorescein? because the adsorp-tion of these two elements is affected unequally (see above).Zwaardemaker 9 has furnished a most interesting botanical analogyto the above-mentioned antagonism between a- and &radiation.The centres of plate cultures of luminous bacteria were exposed to&radiation from mesothorium and to a-radiation from polonium,and the cultures were subsequently photographed by their ownlight, when in both cases the, centre was found to be black, onaccount of the local death of the organism as a reeult of radiation.When, however, part of the mesothorium field was simultaneouslyexposed to polonium radiation, colonies developed in this area,where the two kinds of radiation apparently neutralised each other.This is an example of the antagonism, it should bel noted, betweentwo radiations, whereas in the experiments on the frog’s heart atleast one side of the antithesis is concerned with ordinary matter.These experimentkj with minute unicellular organisms are furtherof considerable interest in showing that both kinds of radiationaffect the protoplasm of one and the same cell; obviously we arehere concerned with a general phenomenon, and it is not surprisingthat other examples have been found, relating to vagus inhibitiontoskeletal muscle, endothelium of the blood vessels, and to the per-meability of the kidney epithelium.H. J.Hamburger andH. Zwaardemaker, Proc. K . Akad. Wetenach. Amsterdam, 1918, 20, 768;Ned. Tijdschr. t’. Geneeak, 1919, i, 260.A., 1918, ii, 182.l o H. Zwaardemaker and J. W. Lely, Arch. Nderbd. Phgsiol., 1917,1,746PHYSIOLOGICAL CHEMISTRY. 151R. Brinkmanll showed that when the frog’s kidney is perfusedfrom the abdominal aorta with a solution free from potassium, thekidney ‘becomes abnormally permeable to dextrose. A t Zwaarde-maker’s suggestion, these authors replaced the potassium chlorideby a small quantity of uranyl nitrate, and found this equally activein restraining the dextrose from passing the kidney, but a mixtsureof potassium and uranium was found to be inactive, in accordancewith what was said above.Inorganic.E. Winterstein l2 has detected iodine in the beetroot, potato,celery, lettuce, and carrot, but failed to find it in thirty-six otherplants; he also failed to find it in milk, cheese, and cow’s urine.The method allows of the detection of 0.04 mg.of iodine added to10 grams of spinach. The presence of selenium in animals, especi-ally in bones and teeth, and in plants has been asserted by T. Gass-mann,l3 but R. Fritsch14 has lately failed to confirm this observa-tion, especially as regards plants; his method allows of the detectionof 0.5-2 mg. in 30-50 grams of plant material. Zinc has beenfound to be constantly present in animal cells, and occurs moreparticularly in the venom of serpents, t o the extent of 0-11-0.56per cent.l5 It is here combined with organic constituenta (perhapsa proteose rich in sulphur), so that it cannot be precipitated byhydrogen sulphide, nor does it dialyse.The zinc contents ofvenoms are in inverse order of their proteolytic and coagulatingpowers, but in the same order as their nucleolytic and.diastaticactivities Traces of zinc have also been found in various foods.16Thus hen’s eggs contain about 1 mg., nearly all in the yolk; cow’smilk contains, on an average, 4.2 mg. per kilo., human milk dis-tinctly more. The same metal is invariably present in oystersgrown in Atlantic waters; the amount could not be correlated withthat of the water in which the oysters grew. Probably copper isalways present also?Pro t eim .The work of various investigators has made it probable thateuglobulin and pseudoglobulin of serum are very closely related.l1 Proc.K . Akad. Wetensch. Amsterdam, 1918, 20, 944.la Zeitsch. physiol. Chem, 1918, 1041. 54; A., i, 190.Ibid., 1916, 97, 307 ; 1917, 100, 182 ; A., 1916, i, 772 ; 1917, ii, 540.Ib!id., 1918, 104, 59 ; +A, i, 191.l6 C. Delezenne, Ann. Inst. Pasteur, 1919, 33, 68; A., 1917, i, 187.l6 V. Birckner, J . Biol. Ohern., 1919, 38, 191 ; A., i, 420.R. S. Hiltner and H. J. Wichmann, ibid., 206 ; d., i, 421152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Thus H. Chick1* described an artificial euglobulin which sheregarded as a mechanical complex originating from the mutualprecipitation of pseudoglobulin and a lipoid substance.P. Hartley l9 could find no difference on analysis of the two proteinsby Van Slyke’s method, and, using the same method, C.Crowtherand H. Raistrick20 failed to find any difference between theeuglobulin and pseudoglobulin of cow’s colostrum and betweenthese proteins and the corresponding ones in ox serum. H. W.Dudley and H. E. Woodman21 have examined the colostrumglobulins by the racemisation method of Dakin and Dudley.22The optical properties of the amino-acids obtained after racemisa-tion and hydrolysis, as well as the rate a t which racemisationproceeds, are identical in agreement with the supposed identity ofthe two globulins of colostrum. A comparative study of thecaseinogens of the cow and sheep, however, by H. W. Dudley andH. E. W0odman,~3 who used the delicate method of Dakin andDudley, referred to above, revealed at least a difference in the“ make up ” of these caseinogens from closely related species; theirconstituent amino-acids are arranged differently.Now H. D.Dakin and H. H. Dale24 have supplied a second example of struetural difference in the corresponding proteins of allied species, andham added additional interest to the result by showing that thetwo proteins are also antigenically different, thus suggesting achemical basis for at least some case of antigenic specificity. Theychose, the crystalline egg-albumins of the hen and the duck. Afterpartial racemisation by N / 2-alkali a t 3 7 O and subsequent hydro-lysis by sulphuria acid, definite differences were found in the opticalproperties of the leucine, the aspartic acid, and the histidine.Thequantities of these and of the other amino-acids obtained were verysimilar in the two casw, so that the difference between hen’s andduck’s albumin seems to be a difference in the arrangement of thesame constituent amino-acids. This difference is, however, sufficientto give an antigenic specificity, for the two crystalline prot’einsbehave as distinct antigens for the anaphylactic reaction. Mostof the experiments were made by sensitising virgin guinea-pigs t oone protein and examining successively the effects of both proteinson the surviving isolated uterus. I n order to give an idea of theextreme delicacy of this reaction, i t may be noted that in one case18 Biochern J., 1914, 8, 404 ; A., 1914, i, 1145.19 Ibid., 541 ; A., 1914, i, 1206.2o Ibid., 1916, 10, 434 ; A., 1916, i, 864.21 Ibid., 1918, 12, 339 ; A., i, 178.22 J . Bi02. Chern., 1913, 15, 263, 271 ; A., 1913, i, 1249 ; Ann. Report,23 Biochem. J., 1915, 9, 97 ; A., 1915, i, 468.1913, 192.24 Ibidea 1919, 13, 248PHYSIOLOGICAL CHEMISTRY. 1530.0001 mg. of albumin in a bath containing 50 C.C. of Ringer’ssolution produced a very distinct contraction of the sensitiseduterus, that is, a concentration of the specific antigen of1 : 500,000,000.Amino-acids.The int’roduction of Emil Fischer’s method of separating mono-amino-acids by the fractional distillation of their esters led tonumerous invmtigations on the amino-acid content of variousproteins. Naturally, these investigations were of very unequalvalue.After the first decade, when the technique had beenthoroughly worked out, we find investigators carefully consideringthe sources of loss involved in the process, for even in the mostfavourable cases the amino-acids isolated do not represent evenapproximately the whole of the protein hydrolysed. The experi-mental losses affect almost entirely the monamino-acids, and aredifficult to overcome. I n the case of zein, the amino-acids isolatedamounted to 85 per cent., but this includes the water taken up inhydrolysis; the results of this investigation led Osborne to a carefulconsideration of the sources of loss. Apart from experimentalerrors, one of these sources might be the presence of unknowncleavage products which had entirely escaped detection.Subse-quently, norleucine, and probably also a-aminobutyric acid,25 wererecognised as possible constituents of protein, but during ,the seconddecade, after the introduction of the ester method, there has beena great falling off in its application, and interest has shifted toD. D. Van Slyke’s methods 26 for finding the distribution of nitrogenin various groups, according to its mode of combination, withoutisolating individual amino-acids.It is all the more interesting, therefore, that H. D. Dakin27 hasfound a new method for separating amino-acids which promises tobe of great use, and has already revealed the presence in casein ofa new cleavage product in an amount of more than 10 per cent.As is so often the case, progress depended on the introduction ofa new technique.Dakin found that, contrary to expectation,certain amineacids can be extracted from aqueous solution bypartly miscible solvents, in particular by butyl alcohol, which isnow available as a by-product in the fermentation process of acetonemanufacture. He hydrolyses the protein with sulphuric acid,removes the latter quantitatively with barium hydroxide, con-centrates, and allows the tyrosine t o crystallise out. The filtratefrom the tyrosine is further concentrated, made approximatelyAnn. Reports, 1913, 198.e7 Biochern. J., 1918, 12, 290; A,, i, 150.as Ibid., 1911, 179164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.neutral to litmus, and then extracted in a continuous apparatuswith butyl alcohol, preferably at 60-80O.Of course, the processis not very rapid, but the surprising thing is that any amino-acidsshould be extracted a t all. The coefficient of partition is entirelyin favour of the aqueous solution, but soon after the extractionhas been started amino-acids begin to crystallise from the butylalcohol in the boiling flask. With reference to this (‘apparentparadox,” Dakin observes that the presence of water is a condition-ing factor, and that the passage of a certain proportion of waterfrom the fluid undergoing extraction to the butyl alcohol mediumis essential. An excess of a salt, such as calcium chloride, in theaqueous phase almost entirely prevents the extraction of amino-acids. I refer to these practical details because I feel, with Dakin,that the use of butyl alcohol and similar solvents will be found ofvalue for many other purposes in biochemistry.Now as regards the kind of amino-acids extracted, it is foundthat proline coma out most readily, as was to be expeoted, sincethis is the only amino-acid appreciably soluble in ethyl alcohol.lDakin obtains the proline in a fairly pure solution without race-misatim in a yield corresponding with 8 per cent.of the caseinogenhydrolysed. D. D. Van Slyke28 found that 7.13 per cent. of thenitrogen in caseinogen is in the non-amino-form, correspondingwith 9.2 per cent. of free proline (if we exclude hydroxyproline).Yet Abderbalden by the ester method could only isolate 3.1 percent. of proline, and that partly racemised.I n addition to proline, butyl alcohol extracts all the mono-basicmonoaminoracids (alanine, valine, leucine, etc.), and this mixtureis at once obtained in a form suitable for separation by the estermethod.Tryptophan is also extracted by butyl alcohol from asolution after one precipitation by Hopkins’ reagent.The more strongly ionised diaminclacids and the dicarboxylicmonoamino-acids are not extracted under the conditions describedby Dakin. The former may be precipitated by phosphotungsticacid, leaving the latter (aspartic and glutamic acids) in a relativelypure state. It was owing tqo this that Dakin could obtain 21 percent. of the caseinogen as glutamia acid hydrochloride, again muchmore than the yield previously obtained by the ester method,and the yield of aspartic acid (as crystalline copper salt) was twoor three times as large as that previously recorded, but the chiefloss occurring in this fraction in the older method is due to a newdibasic aminohydroxy-acid, of which Dakin isolated 10.5 gramsfrom 100 grams of caseinogen.This new acid is almost certainly a-amino-8-hydroxyglutaric orJ .BioL Chem., 1911, 9, 205 ; A., 1911, ii, 780PHYSIOLOGIUAL CHEMISTRY. 1558-hydroxyglutamic acid, CO,H*CH (NH,) CH (OH) *CH2*CO2H.For the evidence for its constitution, Dakin’s paper should beconsulted.It is probable that P-hydroxyglutamic acid had already beenpartly separated by F. W. Fore,man,29 who was unable to pursuehis investigations. The reason why such a relatively abundantconstituent should have escaped the notice of the numerousinvestigators of caseinogen would appear t o be that the free acid isextremely readily soluble in water and crystallises only slowly fromits syrupy solution.The diethyl ester does not distil Withoutdecomposition, and, on heat’ing, the acid is rapidly converted intohydroxypyrrolidonecarboxylic acid. It seems conceivable thathydroxyglutamic acid is the precursor of the base carnitine(novaine) occurring in meat extract.The Origin of Alkaloids from Amino-acids.After the chief amino-acids of protein had become known, variouschemists, who saw in them the precursors of the vegetable alkaloids,began to speculate on the manner in which the alkaloids might bederived from the aminocacids.The first serious speculation of thiskind is due to A. Pictet,30 who laid great stress on the methylationof hydroxy- and imino-groups by means of formaldehyde. H enaturally regarded alkaloids containing a pyrrole or indole ring asresulting from proline, hydroxyproline, and tryptophan, but he alsoderived from the same source piperidine, pyridine, and quinolinerings, which do not occur in protein. He1 imagined that methylatedpyrroles and indoles undergo isomeric change to their ring homo-logues pyridine and quinoline, because 1 -methylpyrrole when dis-tilled through a red-hot tube, yields a small quantity of pyridine.31The next extensive speculation on the phytochemical synthesis ofalkaloids was by E. Winterstein and G. Trier:, who adopted someof Pictet’s ideas, but did not consider the latter’s pyridine synthesissufficiently biochemical, and instead derived pyridine from lysine,which Drechsel had already considered as a possible parent sub-stance, of alkaloids, when he discovered it as the first basic degrada-tion product of protein.The latest and most elaborate paper onthis subject is due to R . Robinson33; theoretically it marks aa0 Biochem. J , , 1914, 8, 463 ; A., 1914, ii, 826.Arch. Sci. phgs. nat., 1905, [iv], 19, 329 ; Arch. Pharrn., 1906, M,389; A., 1905, i, 641. See also F. Czapek, “Biochemie der Pflasleen,”vol. 11, p. 267. A. Windaus and F. Knoop, Ber., 1905, 38, 1166; A., 1905,i, 381.*l Bet“., 1904, 37, 2792 ; A., L904, i, 771.“ Die Alkaloide,” 1910, pp. 263-317.88 Ann. R e w , 1917, 136156 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.great advance, owing to the simplicity of the reactions postulated.From another point of view, however, such speculations may beregarded as mere jeux d'esprit. The chief value of a theory is inthe experiments which i t suggests, and, judged by this test, Robin-son's theory is seen to be of outstanding importance and on adifferent plane from the speculations of his predecessors. Notonly did it suggest to him a simple new synthesis of tropinone,5*which Willstatter had already regarded as the precursor of atropineand of cocaine in plants, but it has now led to the elucidation ofthe constitution of the alkaloids harmine and harmaline,35 and, attlhe same time, of the mysterious base, C,,H,,N2, obtained by F.G .Hopkins and S. W. Cole36 in the oxidation of tryptophan, for thelatter base is identical with harman, a derivative of both alkaloids.Harman, moreover, occurs in nature, for recently E. Spath37 hasshown that it is identical with the alkaloid aribine from Arraribarubru, Mart; the old formula, C,H,,N,, previously assigned to thisalkaloid is erroneous. Harman, aribine, and the oxidation productof tryptophan all have almost certainly the constitution I.(1.1 (11.)Harmine would then have the constitution 11, and harmalinetwo additional hydrogen atoms in the pyridine ring. Perkin andRobinson discuss the synthesis of the two alkaloids in the plant4.They consider that the starting point is a hydroxytryptophan (111),(111.)which is decarboxylated and condensed with aldehyde (IV),probably derived from alanine.The condensation product wouldbe methylated to harmaline by formaldehyde on the lines sug-gested by Pictet (above), and the harmaline oxidised to harmine.Perkin and Robinson are sufficiently bold to predid that thiss4 Ann. Report, 1917, 134.s5 W. H. Perkin, jun., andR. Robinson, T., 1919, 115, 967.86 J. PhysioE., 1903, 29, 451 ; A,, 1903, i, 690.37 Chem. Zeit., 1919, 4& 665PHYSIOLOGICAL CHEMISTRY. 157hydroxytryptophan will be found among the amino-acids fromvegetable proteins. E. Abderhalden and L. Baumann 38 have,indeed, stated that a hydroxytryptophan accompanies tryptophan,but beyond a few analyses nothing further has been publishedabout this substance.Perhaps it would be more hopeful to searchfor it in plants ; thus, a hydroxytyrosine (3 : 4-dihydroxyphenyl-alanine) has been isolated from T7icia faba by M. G~ggenheim,3~although it has never been obtained from protein. Perkin andRobinson also discuss how the base, C,,H,,N, ( = harman = aribine)might arise from tryptophan, C,,H,,O,N,. As the amino-acid hasbeen decarboxylated, not one, but two carbon atoms must havebeen added, which might come from accompanying alanine or fromalcohol or other impurity in the reagents eimployed, or even fromanother molecule of tryptophan. The experimental conditions forobtaining the base are not well uiiderstood. Professor Hopkinsinforms me that on several occasions a yield of 30 per cent.wasobtained, on other occasions nothing. It is furnished by puretryptophan, so that alanine probably plays no part in its form-ation. A. Ellinger 40 failed to isolate it in numerous experimenb ;the mechanism of its formation remains a mystery.Other plant alkaloids which are obviously derived from amino-acids are tetramethylputrescine, from argiizine via ornithine, andhordenine from tyrosine. Hordenine# has acquired additionalinterest, since E. Spath41 has shown it to be identical withanhaline, an alkaloid from Mezcal buttons (Cactaceae). The chiefalkaloid, mezcaline, which has a peculiar physiological action, isfound by Spath to have the somewhat similar constitution:Me0An N-methylhydroxyproline (4-hydroxyhygric acid) has been dis-covered in the bark of Croton gubouga, S.Moore.42 This substancehas two optically active carbon atoms, and probably the same con-€LO*QH-$.!H,CH, CH*CO,H\/NMe88 Zeilsch. phy&ol. Chem., 1908, 55, 412 ; A., 1908, i, 488.80 Ibid., 1913,88, 276; A., 1914, i, 49,40 Ber., 1906, 39, 2615 ; A., 1906, i, 696.U Mortcrtsh., 1919,40, 129 ; A., i, 648.a J. A. Goodson and H. W. B. Clewer, T., 1919,115, 923158 ANNUAL REPORTS ON THE PROURESS OF (JHEMISTRY.figuration as Z-hydroxyproline from proteins. On methyldion ityielded a mixture of the two stereoisomeric betakes, betonicine andturicine, from Betonicn 0ficinuZis.~3 According to H. Leuchs andK. Bormann,44 turicine is very likely formed from betonicine byracemisation (of the a-carbon atom only) during extraction andduring the methylation of Z-hydroxyproline.Histamine.Histamine (P-iminazolylethylamine) continues to a t t r a h atten-tion on account of its powerful physiological action and Pyman’ssynthesis has been repeated and elaborated.45 There are so manysuccessive reactions involved that the yield of histamine is only4.2 per cent.of that theoretically possible from the citric acid em-ployed. It would seem preferable, therefore, to prepare cyano-methylglyoxaline from histidine by Dakin’s method 46 (yield, 80 percent.), and reduce this nitrile to histamine, thus eliminating allstages but the last of Pyman’s synthesis.The investigation of the physiological action of histamine has beencontinued, and it has been shown that the shock-like conditionwhich is brought about in cats by injection of 1 mg.and upwardsper kilo. depends on an action on the capillary endothelium, ofsuch a nature that a large part of the blood collects in dilatedcapillaries; whilst part of the plasma escapes from the vessels intothe tissues.” The significance of histamine in surgical shock isdoubtful, and the same may be said of anaphylactic shock, wherethe similarity of symptoms to histamine poisoning is the only reasonfor postulating its presence. It is still a question whether histamineis only a product of bacteria and fungi or whether it is also fordedby the tissues of the higher animals. Dale and I found it, indeed,in small quantity in the intestinal mucous membrane of the 0 ~ , 4 8but it seemed likely that its presence could be explained by theaction of intestinal bacteria. Recently, however, J.J. Abel andS. Kubota 49 have concluded that histamine is ‘‘ a widely distributedconstituent of animal tissues, organ extracts, and enzymatic pro-as A. Kiing and G. Trier, Zeitsch. phpioF. Chern., 1913, 85, 209; A., 1913,44 Ber., 1919, 52, [BJ, 2089; A., 1920, i, 85.45 K. I(. Koessler and M. T. Hanke, J. Amer. Chem. SOC., 1918, 40, 1706;413 Bioc7wrn. J., 1916, 10, 319 ; A., 1916, i, 698.47 H. H. Dale, P. P. Laidlaw, and A. N. Richards, J. PhykoZ., 1919, 52,Is G. Barger and H. H. Dale, ibid., 1911, 41, 499 ; A., 1911, ii, 217.49 J. PhaTrn. Expt. Ther., 1919, 13;243 ; A., i, 606.i, 708.A., i, 4.110, 355PHYSIOLOGICAL CHEMISTRY.159ducts, such as Witte’s peptone,” and that its occurrence here is‘‘ entirely independent of micro-organisms.” They also state thatit is formed early in the hydrolysis of pure proteins, and that it isidentical with that constituent of the posterior lobe of the pituitarybody which stimulates plain muscle. These results, if confirmed,will have great physiological significance. Abel and Kubota isolatedhistamine from the intestinal mucosa of the dog by a process which1ef.t; no chance for post-mortem changes. From other organs, such asdog’s liver and striated muscle, boiled immediately after death,they- did not actually isolate histamine, but they extracted by asimilar chemical procedure a substance having a closely similarpharmacological action.It is, however, their identification of hist-amine with a pituitary active principle which will arouse mostinterest. There is no doubt that they isolated histamine dipicrate insmall quantity from commercial, dry, entire pituitary gland, butthe exact significance to be attached to this finding is not yet quiteclear. Whether histamine occurs as such in the posterior lobe ofthe flesh g!and or whether it is formed by autolysis during dryingis doubtful, and in any case there is a good deal of evidence, bothchemical and pharmacological, which prevents the identification ofhistamine with the specific plain muscle stimulant, contained inthe posterior lobe. Incidentally, it should be noted that the claimof the Farbwerke vorm. Meister, Luoius & Briining 60 to haveisolated t-he active principles in a crystalline form is unfounded.According to J.J. Abel and M. C. Pincoffs,51 tihe “hypophysin” ofthe Hoechst works is a mixture of albumoses with varying andunknown amounts of aotive and inactive constituents.Hormones.A pituitary hormone has been discussed in the previous section.E, C. Kendall52 has now published a full paper on the isolation ofthyroxin, the thyroid hormone, but this communication is a con-solidation of previous publications, rather than an extension thereof ;the formula :HI:H NHgiven in last year’s Report53 is retained, but no indication is as yetCompare H. Fiihner, Z&&. f. d. D.R.-P. 268841 ; A., 1914, i, 756.ges. exp. Medixin., 1913, 1, 397.6’ PTOC. Nat. A d . &i., 1917, 3, 507.s2 J . Biol. Chem., 1919, 39, 125 ; A., i, 496.63 Ann. Report, 1918, 170180 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.given of the manner in which it was arrived at. The synthesis byOsterberg, first carried out in 1917, has been repeated in 1919, butno hint is given as to the method employed. The isolation of thenatural substance is, however, fully described and illustrated, andit is stated that some three tons of fresh thyroid glands, chieflypigs’, have been used in the research, which has been in progresssince 1910. Thyroxin may exist in three forms, a ketonic or lactamform, as represented above, a tautomeric enolic or lactim form, anda hydrated form, in which the ring is opened. This opening of thepyrrole ring seems also to occur on acetylation, for the N-acetylderivative yields a disilver salt.Perhaps the method of publicationis not unconnected with a desire to protect the synthesis by patent.Organic and biological chemists will await with the greatest interestthe evidence for the constitutional formula and the method of syn-thesis, particularly with regard to the position of the three iodineatoms. Even the elementary analysis must present considerabledifficulty, for the above compound contains about 67 per cent. ofiodine and only 1.60 per cent. of hydrogen. If it were not hydratedin the benzene ring and contained two hydrogen atoms less, thiswould only lower its hydrogen content by 0.35 per cent. Kendallhas also published further observations on the remarkable physio-logical action of thyroxin.54 A dose of 1 milligram increased themetabolic rate of an adult by 2 per cent., but when the imino-hydrogen is displaced the substance becomes inactive.Both thyr-oxin and N-isubstituted derivatives accelerate the metamorphosis ofthe tadpole. This acceleration is also brought about by other iodinecompounds and by iodine itself, and is therefore not nearly asspecific as the great effect on metabolism. It was shown previouslythat thyroxin produces in minute doses all the therapeutic effectsof the entire gland in cretinism and in myxoedema.A hormone of a different type, non-specific and less active, hasbeen isolated by J. W. Le Heux55 in Magnus’s laboratory. It hadbeen shown previously 56 that washed portions of the alimentarycanal (of rabbits, dogs, and cats), suspended in water or Tyrodesolution, give off a substance capable of stimulating the survivingsmall intestine to increased movement. Le Heux has shown thissubstance to be choline.The surviving small intestine of a rabbitmay give off 1-3 mg. per hour. The base was not identified untilit wits found by chance that the use of glacial acetio acid in an54 Proc. Amer. PhyGol Soc., Amer. J . Physiol., 1919, 48, 136.6s P w e r ’ e Archiv, 1919, 173, 8. Compare Proc. K. Aka&. WetewcA.68 W. Weiland, &id., 1912, 147, 171.Amsterdam, 1918, 20, 806; A., 1918, i, 323PHYSIOLOGICAL CHEMISTRY. 161attempted purification greatly increased its activity, owing toacetylation.Acdylcholine is about 400-2500 times as active ascholine in stimulating the movements of the rabbits’ intestine. Itwas also known that the acetyl derivative is very much more potentthan choline itself in lowering blood pressure ; acetylation hereincreases the activity 5000--10,000 fold, and the same ratio appliesto its action on the isolated frog’s heart. Le Heux finally isolatedthe minute quantity of choline given off from the rabbit’s intestineas crystalline platini- and auri-chlorides, and considers that cholineis a natural hormone and the chief cause of the automatic move-ments of the intestine.Glycerol and some of its Derivatives.The industrial production of glycerol by the action of yeast ondextrose is referred to in a subsequent section on fermentation.This process was a direct result of the war shortage of glycerol; thesame cause led to experiments on the utilisation of fatty acids asfood by a committee of the Royal Society,j7 who have confirmedolder experiments that such acids can be utilised by the organismta a very high extent.show that this applies also to fattyacids from “ hardened ” oils, for example, whale oil. Vitamines are,however, complet6ly destroyed in the process of hardening. As thefatty acids ars somewhat unpalatable, feeding experiments havebeen made before with their ethyl esters, which are also very wellutilised. A closer approximation to the natural fats has beenobtained by A. Lapworth and Mrs. L. K. Pearsoq59 who distilledolive oil.and stearin with mannitol and 1.5-2 per cent. of drysodium ethoxide. Glycerol passes over in a yield of nearly 80 percent., and the residue in the flask consists of a complex mixture ofoleates or stearates (of mahnitol, mannitan, and isomannide 1).According to W. D. Halliburton, J. C. Drummond, and R. K.Cannan,59 the “ mannitol ” olive oil is utilised by the animal organ-ism to practically the same extent as olive oil itself. As theseauthors remark, the importance that was att,ached to the investiga-tion during the war is fortunately now no longer so great.With a view to studying the action of lipolytic ferments,E. Abderhalden and E. Eichwald,GO some five years ago, prepared anumber of optically active fats from optically active epibromo-hydrins, but the specific rotation of the fats was very small.WithTheyb7 J . Physiol., 1919, 52, 328.b8 Biochem. J . , 1919, 13, 296; A., i, 570.69 Ibid., 301.6 o Ber., 1914, 47, 1856; A., 1914, i, 801.REP.- VOI. xvr. 162 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the same end in view, these authors have more recently preparedoptically active propylene glycol 61 by the resolution of /3-chloro-n-propylamine which was converted successively into optically active@-chloro-a-propanol, propylene oxide, propylene glycol, and itsdibutyrin. Incidentally, this work led to the synthesis of the opti-cally active, biologically important E-hydroxybutyric acid, which waspxepared from d-propylene oxide, and is found to have the sameconfiguration as E-alanine.The same authors,@ by treating&a-bromohydrin, previously prepared by them, in dry pyridine solu-tion with phosphoryl chloride, have also obtained optically activeglycerophosphoric acid, which must be the first step in the synthesisof a phosphatide, since natural glycerophosphoric acid is opticallyactive.A curious biochemical degradation of glycerol has been discoveredby E. Voisenet,63 who has described a new organism in bitter wines,Bacillzis amaracrylus, which has the characteristic reaction ofdehydrating glycerol t,o acraldehyde.Some Tissue Constituents.Cholesterol and the bile acids are the only representatives in theanimal organism of polycyclic hydroaromat,ic compounds ; bothcholesterol and cholic acid have four reduced rings, and a relation-ship between these subst'ances has been suspected for a long time,all the more because cholic acid and some of its derivatives givecolour reactions similar to those of cholesterol.Thus, H. Wielandand F. J. Weil G4 showed that cholatrienecarboxylic acid, formedby the distillation of cholic acid under diminished pressure, givesthe Liebermann-Burchard cholesterol reaction, and I. Lifschiitz Gconcluded that cholic acid is derived from cholesterol on accountof a remarkable colour reaction, given in identical manner by bothsubstances. A definite proof of the relationship has, however, onlybeen furnished recently.66 The difference in the number of carbonatoms of cholesterol (27) and of cholic acid (24) is due to the presenceof an additional isopropyl group in the former compound; onoxidation with chromium trioxide; these three carbon atoms areremoved as acetone, which cholic acid does not yield under theseconditions. Owing to the further presence of an alcoholic hydroxylgroup and of a double bond, it is impossible to remove the isopropyl61 Rer., 1918, 51, 1312 ; A., i, 2.e3 Ann.Inst. Pastew, 1918, 32, 476; A., i, 55.64 Zeitsch. physiol. Chern., 1912, 80, 287: A., 1912, i. 830.6 5 Rer., 1914, 47, 1459; A., 1914, i, 657.6e A. Windaus and K. Neukirchen, ibid., 1919, 52, [B], 1915 : A . , 1920.62 Ibid., 1308 ; A., i, 3.i, 41PHYSIOLOGICAL CHEMISTRY. 163group from cholesterol itself without destroying the rest of themolecule. The displacement of the hydroxyl by hydrogen and thereduction of the double bond furnishes cholestane, C27H48, and whenthis hydrocarbon is oxidised with chromium trioxide, there resultsthe acid, C24H4002, which is isomeric with cholania (cholanecarb-oxylic) acid, a reduction product of the cholatrienecarboxylic acid,CWHS402, of Wieland and Weil, referred to above.The acids,C,H4,0, from cholesterol and from cholic acid are, indeed, verysimilar ; they are not identical, however. Their close similarityreminded Windaus and Neukirchen of that existing betweendihydrocholesterol obtained from cholesterol by ordinary chemicalreduction and coprosterol, its reduction product formed by intes-tinal bacteria. The latter alcohol is derived, not from cholestane,but from a diastereomeric hydrocarbon, $-cholestane (coprostane) .67Now the cholanic acid of Wieland and Weil is derived from+-cholestane.On oxidation, the latter hydrocarbon yields acetoneand an acid, C24H4,02, isomeric with that from cholestane andidentical with the reduction product of cholatrienecarboxylic acid.Hence this is the bridge between cholesterol and the bile acids.The relationship may be summarised as follows:CHMe,*CH2*C2,H3,*OH + CHMe,*CH,*C,,H,, @02H*C23H33Cholatriene-Cholesterol. Cholestane. carboxylic acid.I I++2H 4'""CH Me2*CH ,*C,,H3,*OH -+ CHMe,-C H,*C,,H3, 2-2 CO,H *C23H39Coprosterol. J. - Cholestane. Cholanic acid.I t is note'worthy that the two naturally occurring derivatives ofcholesterol, namely, coprostsrol and cholic acid, are both derivedfrom $-cholestane, and not from cholestane, t,he laboratory reduc-tion product of cholesterol.The chemistry of the lipoids is being simplified by Levene andhis collaborators, and there are indications that the number ofindividuals in this group is smaller than has been supposed.Thus,cuorin, the name given to the lecithin-like substance from heartand other muscles,6* is, according to P. A. Levene and S. K o r n a t ~ ~ u , ~ ~not an individual, but an impure kephalin, in agreement with the67 Compare A. Windaus and C. Uibrig, Ber., 1915, 48, 857; A., 1915,68 A. Erlmdsen, Zeitsch. phpiol. Chem., 1907, 51, 71 ; A., 1907, i, 371.69 J . Biol. Chem., 1919, 39, 83, 91 ; A., i, 466.G 2i, 678164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.view already expressed by H.Maclean.70 The so-called lecit<hillfrom heart muscle is a mixture of lecithin and kephalin; on reduc-tion with hydrogen and palladium, the substance has all the proper-ties of crude hydrolecithin of egg-yolk,71 and can be fractionatedinto hydrolecithin and hydrokephalin. According to Levene andKomatsu, the opinion of Fraiikel and Linnert,72 that thereare specific phosphatides in the individual organs of the sameanimal, is unfounded. Perhaps the number may be reduced t otwo, namely, lecithin and kephalin. As usually prepared, kephalinis mixed with its decomposition products, chiefly arising throughloss of a fatty acid group, either by enzymes or by chemicalmanipulation.The existence of methylguanidine in normal urine had alreadybeen rendered very doubtful by A.J. Ewins,73 who suggested thati t is formed by oxidation from creatinine during the precipitationwith silver salts in alkaline solution. T. Greenwald74 now deniesthat i t ‘occurs in muscle. Even when mercuric acetate is employedas precipitant in the presence of sodium carbonate, creatine isoxidised to a-methylguanidinoglyoxylic acid,75NH,*C( :NH)*NMwCO-CO,H,and this substance(, on evaporation with hydrochloric acid, yieldsmethylguanidine.Even if methylguanidine is absent from normal muscle and urine,this enhances rather than diminishes the importance t o be attachedto its undoubted excretion after parathyroidectomy, which was dealtwith in last year’s Report.76 For a further discussion of methyl-guanidine, as well as its relationship to creatJne and arginine, thePresidential Address to the Physiological Section of the BritishAssociation, 1919, by D.N. Paton, should be consulted.I have here only space to direct attention to interesting indirect,support of the view77 that arginine and histidine are largelycapable of replacing one another in metabolism. This support hasunexpectedly come from the purely chemical side, for R. G. Fargher70 “ Lecithin and Allied Substances,” 1918, p. 52 (Longmans).71 P. A. Levene and C. J. West, J. BioE. Chem., 1918, 33, 111; 34, 175;72 Biochem. Beitsch., 1910, 24, 268 ; A., 1910, i, 295.73 Biochem. J . , 1916, 10, 103 ; A., 1916, i, 528.74 J . Amer. Chem. SOC., 1919, 41, 1109; A., i, 562.7 6 L.Baumann and T. Ingvaldsen, J. BioE. Chem., 1918, 35, 277; A.,35, 285 ; A., i, 98, 288, 421.1918, i, 423.Ann. Report, 1918, 152.77 H. Ackroyd and F. G. Hopkins, Biochem. J . , 1916, 10, 551 ; A,, 1917,i, 237. Compare also Ann. Report, 1918, 155PHYSIOLOGICAL CHEMISTRY. 165and F. L. Pyman 78 have shown that 2-benzeneazoglyoxaline yieldson reduction aniline and glycocyamidine.flK*”H CH,*NHCH--” CO--NH >C*N:NPh -+ I >C:NH + NH,Ph.It should also! be remembered in this connexion that creatinine isN-meth ylgl y cocyamidine.On the other hand, H. B. Lewis and E. A. Doisy 79 have assailedAckroyd and Hopkins’s conclusion that arginine and histidine arepre-eminently the raw material for the synthesis of purines. Theyfound no difference in the uric acid output of two men maintainedfor successive periods on purinefree high protein diets containing(a) much arginine and histidine, ( b ) little of these amino-acids.A ccesso~y Food S~cbstccn cesThe1 present state of our knowledge on these substances (mis-named “vitamines”) has been admirably summarised by a com-mittee consisting of F.G. Hopkins (chairman), H. Chick, J. C.Drummond, A. Harden, and E. Mellanby,so appointed jointly bythe Lister Institute and Medical Research Committee. This reportconstitutm a veritable monograph of 107 pages with 18 illustrationsand more than 200 references t o the literature, extending to thefirst few months of the current year. It deals with accessory factorsand growth, beri-beri, scurvy, ricket.s, pellagra, and practicalproblems relating to the diets of adults and infants. On accountof the appearance of this compilation and the fact that the interestin accessory food substances is still almost entirely physiological, Ipropose to limit myself here to very few references.E. M. Delf g1compared, necessarily in a very crude manner, the rate of destrua-tion of the antiscorbutic substance in cabbage on heating tot 60° andto 90-looo. From the relatively low temperature-coefficient ofthis reaction (1.3 for loo rise of temperature), she1 concludes thatthe destruction does not consist in the heat denaturation of aprotein or enzyme. T. B. Osborne and L. B. Mendel82 find thatcertain green vegetables, for example, spinach, are rich in fat-soluble A even after drying a t 60°, and they have succeeded inextracting the substance from dried leaves by means of ether.83The green extract was evaporated on starch, and gave a very potent78 T., 1919, 115, 221.7 0 J .Biol. Chem, 1918, 36, 1 ; A., 1918, i, 559.‘‘ Special Report Series of the Medical Research Committee,” No. 38 ;H.M. Stationery Office, 1919.81 Biochem. J., 1918, 12, 416.83 Proc. SOC. Exp. Biol. Med., 1919, 16, 98.82 J . Biol. Chem., 1919, 37, 187166 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.preparation. The fact that this may be described as a distinctadvance will illustrate the very rudimentary nature of our know-ledge concerning this substance. Water-soluble B is much morestable, and is not destroyed completely a t 120° in three hours unlessalkali has been added .*4 The antiscorbutic substance is readilydestroyed by heat, but nevertheless cow’s milk, rapidly dried a t ahigh temperature, retains some of its antiscorbutic properties.Onthis important practical question a recent, careful paper by R. E.Barnes and E. M. Hum085 should be consulted.Enzymes and Fe rnz e nt a t ion.The importance of adsorption as a preliminary to enzyme actionmay provide the excuse for a brief reference to papers by I. Lang-muir,86 who, for example, suggests that the spreading of oil 0.11water is due t o the residual valencies in the carboxyl group beingheld by the residual valencies of the water, so that the oil mole-cules lie in a single layer with their hydrocarbon chains verticallyupwards.The layer is also one molecule thick in the adsorption ofgasm by plane surfaces of platinum, mica, and glass, Langmuirobjects that in the porous substance usually worked with the surfaceis not known. A. M. Williams87 has deduced a theory of gaseousadsorption which, over a long range, agrees very closely with ex-perimental observations ; it also enables one to calculate the surfaceof the adsorbent, and it supports the views of Langmuir and othersas to the smallness of the range of molecular attraction.Because specificity in enzyme action is closely related to’ theasymmetric structure of the substrate and adsorption is a necessarypreliminary, C. W. Portelr and C . T. Hirst88 have prepared(raeemic) dyes with an asymmetric carbon atom; these dyes arepartly resolved when wool is dyed with them.The result isspecially significant if we consider the dyeing process to be one ofadsorption rather than of chemical action.Sucroseis hydrolysed by dialysed colloidal silicic acid ; 89 concentrated solu-tions of the acid soon change their degree of dispersion, becomeless active, and finally coagulate. Sucrose is also hydrolysed to as4 Compare C. Voegtlin and G. C. Lake, Arner. J . Physiol., 1919, 47, 558.86 J . Amzr. Chem. Soc., 1916, 38, 2221 ; 1917, 39, 1848 ; 1918, 4, 1361 ;87 Proc. Roy. Soc., 1919, 96, [A], 287, 298; A., ii, 496.s8 J. Amer. Chem. SOC., 1919, 41, 1264; A., i. 658.89 Albert Mary and Alexandre Mary, Compt. rend., 1918, 167, 644:;The action of invertase has been simulated in t>wo ways.Biochem. J., 1919, 13, 306.A ., 1917, ii, 19, 525; 1918, ii, 430.A.,ii, 14PHYSIOLOGICAL CHEMISTRY. 167slight extent (about 1 per cent.) when a solution is passed five timesthrough a Richardsoii pulveriser,gO which ionises the watermechanically; the biological interest lies in the fact that theinversion is increased in Ringer’s solution, and particularly bytraces of zinc or manganese, but is prevented by enzyme “poisons,”such as potassium cyanide. The favourable effect of some inorganicsalts and the inhibitory effect of antiseptics on the growth ofL48pergiZZu8, first studied by Raulin, runs also parallel to the effectsof these salts and antiseptics on the inversion of sucrose, as studiedby Abelous and Aloy.Pepsin has lately been purified by L.Davis and H . M. Merker,glwho consider that the pure enzyme might be a gluco-protein. A tall stages of purification, the rennetic activity corresponded closelywitch the proteolytie. A simple method of purifying trypsin andother enzymes has been indicated by J. T. WOO^,^^ who allows aconcentrated solution to soak into filter paper, which is then rapidlydried a t a low temperature. On extracting with water, the enzymedissolves more rapidly than some impurities, and an active solutioncontaining very little protein can be obtained.The numerous fermentlative changes which can be brought aboutby fungi and by yeast continue to be studied intensively. ,4sper-9iZZzi.s niger is found93 to ferment large quantities of sucrose, withthe production of 60-70 per cent.of acids, mostly fumaric with alitkle citric; the solution becomes acid to Congo-red. It hadalready been observed that Rhizopus niy/ricans (Mucor Stololtifer)will do the same.94 The various stages involved in the productionof succinic acid from glutamic acid by yeast are, according toC. Neuberg and M. Ringer,gs the following:C0,H*CH2*CH,-CH(NH,).C0,H +C0,H*CH,*CH2* CO- C0,H -+CO,H*CH,*CH,*CHO + CO,H*CH,*CH,-CO,H.The last reaction, conversion of aldehydopropionic into succinicacid, may be brought about, by maceration juice in the absence ofair, and all the stages have now been shown to be purely enzymaticexcept the first, which is only known to occur in the living cell.The discovery of a ferment! which can convert an amino-acid intothe corresponding keto-acid would indeed be interesting.Succinic acid is but one of the by-products of alcoholic ferment.91 J .Amcr. Chem. Roc., 1919, 41, 222; A., i, 180.92 J . Soc. Chem. Ind., 1918, 37, 3 1 3 ~ ; A., i, 102.93 C. Wehmer, Ber., 1918, 51, 1663; A., i, 58.94 F. Ehrlich, ibid.. 1911, a, 3737 ; A., 1912, ii, 192.Biochm. Zeitsc7~., 1918, 91, 131 ; A . . i, 56.J. E. Abelous and J . Aloy, Compt. rend., 1919, 168, 1125; A., i, 310168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ation; glycerol is another, and a more important one, for it isformed from the sugar itself. During the war, this circumst'ancehas assumed enormous importance in Germany, for it made possiblethe production of glycerol from sugar on an industrial scale; i t wasdiscovered that, under special conditions, the ordinary yield ofglycerol of about' 3 per cent.can be increased a t least tenfold.Although it was known that Germany possessed a new biochemicalsource of glycerol, the process was kept, a close secret until itspublication by K. Schweizer96 and by W. Connstein andK. Ludecke.97 The latter were the real autlhors of the industrialpr0cess,~8 the essential feature of which is the employment of con-centrated sugar solutions containing a large quantity of sodiumsulphite. Crude sugar, or even molasses, may be used, and neitherthe race of yead nor the1 temperature are of much influence on theyield of glycerol. The monthly output in Germany finallyamounted to 1000 tons, 100 parts of sugar yielding 20 parts ofpurified glycerol, 27 of alcohol, and 3 of aldehyde.The process isbased on the work of Neuberg and his pupils, and he has alsolately furnished a theoretical explanation in a paper,99 which shouldbe consulted by all interested in the theory of alcoholic ferment-ation. I n 1913 C. Neuberg and J. Kerb1 put forward the hypo-thesis that dextrose, by loss of two molecules of waker, furnishesthe aldol of methylglyoxal, CsH804, which breaks down to twomolecules of this keto-aldehyde, C,H,02, one of which is reducedto glycerol, whilst the other is oxidised t o pyruvic acid:CH,:C(OH)-CHO + H,O H, CH,(OH)*CH(OH)*CH,*OH+ II = +CH,:C(OH)*CHO 0 CH,-CO*CO,HThe pyruvic acid is decarboxylated by carboxylase t o acetaldehyde,CH,=CO*CO,H = CO, + CH3:CH0,and the latter is reduced to alcohol, whilst from a further moleculeof methylglyoxal pyruvic acid is regenerated.CH;CO*CHO 0 CFT,*CO*CO,H+ II =CH,*CHO H2 + CH,*CH,*ORs6 Helv.chim. Acta, 1919, 2, 167 ; A., i, 239.97 Ber., 1919, 52, [B], 1385; A., i, 463.s8 Compare also J . SOC. Chem. Ind., 1919, 38, 2 8 7 ~ .ss C. Neuberg and E. Reinfurth, Ber., 1919, 52, [B], 1677 ; A., 1920, i, 124.Biochem. Zeitsch., 1913, 58, 158 ; A., 1914, i, 118PHY SIOLOQICAL CHEMISTRY. 169Hence methylglyosal and pyruvic acid would be intermediatestages, glycerol and acetaldehyde necessarily by-products ; as amatter of fact, the latter are always both present in alcoholicfermentation; the circumstance that the only known form ofmethylglyoxal does not ferment is no fatal objection, since it isprobably the most stable of the many possible forms. (At leasttwenty-two are conceivable.)Next it was found 2 that slightly alkaline salts do not suppressthe fermentation, but increase the yield of the by-products at theexpense of tlhe main products, and then i t was shown3 that by theuse of sodium sulphite the acetaldehyde may be fixed in a yieldof 70 per cent. of the theoretical as the additive compoundCH,*CH(OH)*O* S0,Na.The similar additive product of pyruvic acid undergoes decarboxyl-ation. As the acetaldehyde is now no longer reduced, the(' hydrogen of fermentation " is used up in forming more glycerol.Since the aldehyde-sulphite compound dissociates, its yield, andthat OF the glycerol, should depend on t,he concentration of thesodium sulphite employed, but not be proportional to i t (massaction). The theory further demands that glycerol and acetcaldehyde should be formed in molecular proportions. Both thesepostulates are fulfilled; thus, f o r 100 grams of dext'rose and vary-ing amounts of sulphite, the following yields were obtained :Na,SO, used.Grams.Yield of Yieldac eta1 deh y de .33 11-90 23-3750 12-52 24-8675 13.89 27-61150 18-65 36-96of gl yc er 01.Grams. Grams.The molecular ratio acetaldehyde : glycerol is therefore 0.94-0.95instead of 1. The highest yield of glycerol corresponds with 35.06per cent. of hexose, or 70 per cent.. of the moiety which couldfurnish glycerol. For a 100 per cent. conversion, the fermentationwould have to proceed completely according to the equationC,H,,O, + Na,SO, + H,O =C3H803 + CH,*CH(OH)*O-SO,Na + NaHCO,.The shortage of 30 per cent. is due to unsuppressed dissociation ofaldehyde-sulphit'e. With the same relative quantities of sugarC. Neuberg and E. Fiirber, Biochem. Zeitsch., 1916, 78, 238 ; A., 1917,i, 502.C. Neu1)erg and E. Reinfurth, ibid., 1918, 89, 365 ; A., 1918, i , 517 ;-4nn. Report, 1918, 166.Q170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and sulphite in dilute solution, the dissociation is much greaterand the yield of glycerol falls off considerably. I n their mostrecent paper, Neuberg and Reinfurth state that insoluble calciumsulphite suspended in the fermenting solution has advantages overthe sodium salt. As calcium sulphite has a neutral reaction, itseems that alkalinity is not an essential condition for an increasedproduction of glycerol. GEORGE BARGER

ISSN:0365-6217    

DOI:10.1039/AR9191600147

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.ALTHOUGH 1919 will scarcely rank among the years of greatachievements in agricultural chemistry, it has been notable for somehighly promising developments. Chief among these, as far as thiscountry is concerned, is the intention of the Board of Agriculture,as announced in the Press, to set aside the sum of $2,000,000 foragricultural education and research during the next five years, ofwhich 32250,000 will be available for research. Although this sumdivided among ten or twelve institutions and spread over five yearsdoes not at the present value of money represent affluence, it is,nevertheless, a highly important advance on anything previouslyattempted in this country.Another significant event is the establishment by an importantagricultural company-the Olympia Co ., under the chairmanship ofMr. Joseph Watson-of a research laboratory under the able guid-ance of Professor C. Crowther, late of the Leeds University. Hehas already secured the services of two of the best of the youngermen, Mr. C. T. Gimingham of the University of Bristol Agricul-tural Research Station, and Mr. H. Hunter of the Irish Departmentof Agriculture. Apart from investigations incidental to its advisorywork for the Company, the department will be specially equippedfor work on animal nutrition, plant breeding, and problems of soiland plant nutrition.Soil In@ es t ;gat ions.The investigations on soil in recent years have fallen in the maininto three great groups, dealing respectively with (1) the solutionwith which the soil is moistened, (2) the population of micro-organ-isms living on the plant residues which form an important partof the soil, and (3) the bioche.mica1 conditions in the soil.Hithertothese investigations have been on widely different lines, but thereseems iiow the possibility of a closer approximation.The iniportance of the soil solution in the nutrition of crops was171 G" 172 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.first, adequately recogiiised by Whitney and Cameron, working inthe United St-ates a t Washington. The more recent work has beeindone a t the California Experiment Station. The general outlinesof the earlier work were given in last year's Report, and two furtherpapers have been published this year.A careful study has beenmade of the relation of the concentration and reaction of thenutrient medium to t'he growt>h of the plant.1 The rate of growthof barley in water cultures was found to increase with increasingconcentration up to a certain point, beyond which there was nofurther growth. The amount of substance absorbed, however,increased with the concentration to a greater extent and over alonger range than did the growth. Contrary to some of the previouswork, no sufficient evidence was found that plants require anyvery definite ratios of elements or ions; indeed, considerablelimits of variation seemed permissible so long as the total supplyand concentration of the elements were adequate. Working onrather different lines, and in soil instead of water cultures, J.S.Burd2 finds that the absorption of various nutrients by barleygrowing in soil increases rapidly up to the ninth week, and then areversal takes place, there being a loss of material from the aerialparts of the plant to the root, or even to the soil, although no actualtransfer to the soil can be definit'ely established. After the eleventhor twelfth week, however, there is a further absorption whichcontinues to the end of the growing period, when a further lossappears t o set in.The solution moistening the soil particles has been extracted byvarious methods, and it has also been studied in the soil by thefreezing-point, method, more particularly by Bouyoucos and hiscolleagues .3 Perhaps the most interesting paper on the subjectduring the year has been a discussion4 of the numerous dataalready accumulated.Previous investigators have shown t.hatthe soil solution in quartz sand and in very light sandy soilsobeys approximately the same law as dilute solutions, the freezing-point depression varying as the concentration. I n the case ofordinary soils, however, this rule does not hold, the freezing-pointdepression increasing more rapidly than the moisture content fallsoff. Boupoucoa explained the discrepancy by supposing that someof the soil nioistxire plays no part in the phenomena of the depres-sion of the freezing point, and he deducts from the total moistureD. R. Hoagland, J . Agric. Res., 1919, 18, 73.Ibid., 1919, 18, 61.G.J. Bouyoucos and M. M. McCool, Michigan Agric. Coll. Expt. StationTech. Bulls. 24, 31, 36, 37 and 42; also J . Agric. Res., 1918, 15, 331 ; A.,i, 115. 4 B. A. Keen, J. Agric. Sci., 1919, 9, 400AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 173a sufficient amount, which he calls the “unfree water,” to leavea balance of “free water” that will conform to the freezing-point law. Assuming the distinction to be valid, Keen showsthat a mathematical relationship exists between the “ free,” the“ unfree,” and the total water; one equation defines the relation-ship over the whole range. Exactly the same thing happened inregard to the rate of evaporation of water from soils; one equationthere also covered the whole range, and the various constants andcritical points announced by other workers were found to beequilibrium points only, and not breaks in the physical state of thewater in the soil.5The physical properties of the soil are determined by its peculiarstructure : a mass of small, hard, mineral particles of varying dimen-sions intimately associated with a sufficient quantity of colloidalmatter to impress colloidal properties on the whole.The relation-ships of adsorption to coagulation have been discussed by some ofthe Italian workers.6 Setting out from the obvious propositionthat mutual attraction occurs where particles and ions with oppo-site charges come into contact, resulting in the neutralisation ofthe charges and formation of absorption compounds, the authorsattempt to show that the consequent decrease in concentration, bothin colloidal and ionic-molecular solution, is f avourable to productive-ness.The phenomena in regard to protein have been discussed bythe Wilsons,i but they are not necessarily related to the soil pheno-mena. The problem has been attacked in another way in Germany.8A salt is allowed to act on a soil, and is then extracted with waterand tthe effect on the physical properties studied. Salts of univalentmetals, particularly sodium salts, damage the texture of the soil ;those of bivalent metals do not-. I n this case, however, the effectsare not so much those of the actual saltq as those produced by thesubsequent hydrolysis after the salt is washed away.An attempt h a been made9 to ascertain the effect of certaincolloidal substances on the growth of wheat seedlings in culturesolution.They acted adversely, reducing the concentration byadsorption. Colloidal silica, however, proved to be an exception,and caused an increase not only in growth but also in the amountof silica in the plant.J . Agric. Sci., 1914, 6, 456.* A. de Dominicis and P. Chiarieri, Staz. sper. agr. ital., 1917, 50, 451 ;J. A. Wilson and W. H. Wilson, J . Amer. Chem SOC., 1918, 40, 886;G. Hager, J . Landw., 1918, 66, 241.D. S. Jennings, Soil h’ci., 1919, 7, 201.A., i, 142.A., 1918, ii, 260174 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The Biochemical Changes in the Soil.The soil organisms draw their supplies of food material and ofenergy from the stores of plant residues contained in the soil.Thetwo most important constituents of the plant residues are the cellu-lose and the proteins; the former give rise t o the so-called humuswhich has important physical effects in the soil; the latter yieldammonia, which becomes subsequently oxidised to form the nitratesessential to the nutrition of the crop.The organism concerned in the decomposition of cellulose has beenstudied in the Rothamsted laboratories. It decomposes celluloseunder aerobic conditions with comparative ease. It more closelyresembles the epirochxts than the bacteria, ahd is therefore namedSpirochaeta cytophnga. It's vegetative growth takes the form of asinuous filamentous cell, which is very flexible, but only feeblymotile ; a.pparently it does not possess flagella.This filamentousform can pass through a number of phases, yielding finally sphericalbodies somewhat resembling spores, but differing in several impor-tant respects, so that they are called by a different name, sporoids.The organism requires combined nitrogen, which it prefers in theform of nitrates, ammonium salts, amides, or amino-acids. Peptoneserves in dilute solutions, but a toxic limit is soon reached, whilstths conventional nutrient gelatin and nutrient agar are bothunsuitable.The carbon requirements of the organisms can be met only bycellulose so fgr as is known. Npne of the sugars, alcohols, or salts oforganic acids has proved effective, and some were definitely toxic.Given a suitable simple nitrogen compound and its other require-ments, the organism is able energetically to decompose cellulose,producing, among other things, a pigment somewhat like carotin, amucilage which does not yield optically active compounds on hydro-lysis, and small quantities of volatile acids.It was shown that theproducts are suitable for the needs of Azotobacter and allow of theassimilation of gaseous nitrogen.The decomposition of the proteins is brought about by bacteriaand apparently also by fungi, although on the latter point evidenceis still scanty. Fungi have been isolated in considerable numbersfrom soils, and their behaviour towards culture media has beenstudied. Thus it has been shown1* that they decompose carbo-hydrates, absorbing ammonia and producing protein, although inabsence of carbohydrates they decompose protein, forming ammonia.It is argued that, moulds are likely to be unfavourable to soill o H.B. Hutchinson and J. Clayton, J . Agric. Sci., 1919, 9, 143.It S. A. Waksman, SoiZ8ci., 1918, 6, 137; A . , i, 116AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 175fertility, except perhaps in so far as the formation of enzymes in thesoil is concerned. The difficulty is that the fungi are a plastic groupwhich may behave in one way under one set of conditions, but quitedifferently under other conditions. Evidence, however, has beenadduced that fungi may be positively harmful.12Pending further investigations into the part played by the fungi,it is usual to confine attention to bacteria.In recent years baderi-ologists have been content to study “ammonification ” as a wholewithout much reference to the individual species of organisms con-cerned. A few attempts, however, have been made a t studying theindividual species. I n the United States H. J. Conn13 finds thatnon-spore formers predominate in the soil, thus confirming theobservations of Russell and Hutchinson a t Rothamsted; he con-siders that? spora-formers are scarcely active in the soil under normalconditions, and that ammonia formation is mainly brought about byncn-spore formers (Tech., 51). I n this he runs counter to theaccepted tradition, which is that the spore formers include some ofthe most active forms. Rilarchal had concluded that B.mycoideswas one of the most common ammonia producers in the soil. Conncontroverts this statement., and maintains that of the‘eight impor-tant ammonifiers studied by Marchal only one, namely, B. fiwirescensZip. (a non-spore former), is a typical soil organism.Of the true soil organisms two are described 14 which, whilst notvery numerous in unmanured soil, multiply vigorously on additionof farmyard manure and produce ammonia: Ps. fiuorescens and 2‘s.cnudatus. ‘These organisms are described in sufficht detail to allowof identification by other workers.It is fnrt’her shown15 that the ,4ctznomycetes form a considerableproportion of the soil organisms-no less than 17 per cent. in amedium soil, and a higher proportion in heavy soils or those richin organic matter.An interesting study has been made16 of the rate a t which nitratesaccumulate in Egyptian soils under natural conditions.Normally,the process yields more nitrate than the crop requires, which mayaccount for the usual ineffectiveness of nitrogenous manures on thecotton crop in Egypt. The rate of nitrification, however, was muchaffected by the moisture content of the soil-more, indeed, than byany other single factor-and the whole process apparently came tol2 E. B. Fred, Soil Sci., 1918, 6, 333.l3 N. Y . Cornell, Agric. Expt. Sta. Bull., 338, 1913 ; Tech. Bull. 51, 1916 ;l4 H. J. Conn and J. W. Bright, J . Agric. Res., 1919, 16, 313.l5 S. A. Waksman and R. E. Curtis, Soil Sci., 1918, 6, 300.l6 J. A. Prescott, J . AgriC.Sci., 1919, 9, 216.Tech. Bulls. 57-60, 1917, and 64, 1918 ; J . Agric. Res., 1919, 16, 313176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.a standstill during the summer fallow, a time of low moisturecontent and high temperature. I n pot experiments there was morenitrate produced under fallow conditions than in the presence of agrowing crop, as has already been observed both in England andAmerica.It has always been supposed that the nitrogen cycle was compara-ti\ ely simpla, the soil nitrogen compounds being changed to nitrates,which, unless washed out of the soil, are then absorbed by plantsand built up into fresh protein compounds. The results of a long-continued soil experiment, at Rothamsted are now summarised, andshow 17 that this simple view is scarcely sufficient; the nitrate forma-tion in a poor, unmanured soil, so far as can be measured by thequantity washed out in drainage water, proceeds at a very slowlydiminishing rate for an almost indefinike period-certainly for morethan fifty years-and during this time it appears almost uniformover a period of, say, from ten t o fifteen years.The simplestexplanation of the phenomena is that the nitrates formed in any oneyear are not wholly available for the plant or for loss in the drain-age water; a part may be supposed to be taken up a t once by otherorganisms aucl converted into protein, which subsequently againnitrifies. Thus the whole of the nitrate can never be exhausted;the process is expressible by an asymptot.ic curve.This idea of animmobiliser will probably be found helpful in dealing with t,he soilphenomena.There is, however, a further complication in natural conditions.For convenience of investigation the decomposition of cellulose andof protein are studied separately, but in point of fact the two reac-tions proceed simultaneously in the soil and profoundly influenceeach other. It has already been shown that the organisms decom-pGsing cellulose require a supply of nitrate or other soluble nitro-genous compound. I n like manner organisms decomposing sugarapparently require nitrates, and there is, in addition, the possi-bility that they actually decompose nitrates with. evolution ofgaseous nitrogen or nitrogen compounds.Both these actions tend to loss of nitrogen.There is a third typeof action that tends to a gain of nitrogen. I n the presence of easilyoxidisable carbohydrates certain orgqisms can fix gaseous nitrogen,converting it into protein, which sub$equently decomposes and givesrise to ammonia, and then to nitrates.'Thus the addition of sugar or straw to the soil has a drasticeffect on the nitrogen cycle, the possibilities being a loss of nitrate intwo ways and a gain of protein in two ways-an absolute gain fromfree nitrogen and a relative gain from nitrate or ammonia. Whether1 7 E. J. Russell and E. H. Richards, J . dgric. Sci.,lQ19, 10, 14AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 177the net change will be a gain or less of nitrogen depends on circum-stances. Thus in recent experiments the addition of 2 per cent.ofsugar to soil was found 18 to diminish the first crop, but slightly toincrease the subsequent ones. Straw diminishes the crop for the firsttwo years, but gave a small increase in the third year; over thewhole period, however, the effect was negative.These various actions make it impossible to foretell the fate of agreen crop ploughed into the soil-a practice known as greenmanuring, common in this country, in India and elsewhere.I n a recent Indian investigation,lg the stems and ro0t.s of legu-minous plants were found to yield scarcely any nitsate, presumablybecause of the action of their non-nitrogenous constituents.Further, there were marked differelnces in the rates of nitrificat'ionof some of the oil cakes.20The importance of the changes effected by micro-organisms isso great that numerous attempts have been made t'o correlate soilfertility with bacterial activity, as indicated by rates of ammonifi-cation, nitrification, etc.Obviously correlation can be expectedonly when the nitrogen supply is a limiting factor in crop pro-duction, and even then regard must be had to the supplies in thesoil of protein compounds on which the organisms can act. Withthese limitations, however, some relationship between bacterialactivity and soil fertility is generally found. I n a detailed examina-tion of Hawaiian soils,21 the rate of ammonification afforded nosharp indication of fertility, as the differences between the g o d andthe poor soils, although in the right direction, were not sufficientlymarked.On the other hand, the rate of nitrification was a muchsafer index, and was, indeed, the most trustworthy of all themethods tested ; this experience has been obtained elsewhere.22This does not imply that the process of nitrification is responsiblefor the yield; it may be that both the plantl and the nitrifyingorganisms are limited by the same set of factors.EfJect of Salts.-The effect of inorganic salts on bacterial activityhas been investigated by Greaves and his colleagues at the UtahExpt. Station,23 where alkali soils present t roublesome problems.18 0. Lemmermann and A. Einecke, Landw. Vcrsuch.s-Stat., 1919, 93, 209.19 N. U. Joshy, Agric. J. I n d i a , 1919,14, 395.20 F.J. Plymen and TI. V, Ral, ibid., 414.21 P. S. Burgess, Soil Sci., 1918, 6, 449.22 For example, in Kansas by P. L. Gainey, ihid., 1917, 3, 399; -4.,1917, i, 529; in Pennsylvania, by G. P. Given, Penn. Rept., 1912-13, 204 ;in California by C. R Lipman and Burgess, CaZ. BUZZ. 260, 107 ; in Iowa byP. E. Brown, J . Agric. Res., 1916, 5, 855.28 J. E. Greaves, E. G. Carter, and H. C. Goldthorpe, J . Agric. Res., 1919,16, 107 ; A., i, 238178 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.The method consists in adding 2 per cent. of blmd meal to thesoil, then bringing up the moisture to 20 per cent., and finallyincubating at 28-30° for twenty-one days. The conditionsobviously are unnatural, and it would have been interesting tohave made the comparison also under normal conditions.Never-theless, the results are distinctly interesting. The effects of thevarious salts in depressing the activity of the ammonifyingorganisms are in the main similar to their action in depressingthe growth of wheat seedlings. The effect on nitrifying organisms,however, is more pronounced. The salts commonly occurring inalkali soils, sodium sulphate, sodium carbonate', and calciumchloride, are very toxic to bacterial activity, and hence thepossibility that part of the unsuitableness of an alkali soil forplant growth may lie in the depression of the essential nitrateproduction process.Nitrogen fixation is also affected considerably by thel presenceof dissolved salts.24 Sodium chloride in small quantities acted asa stimulant, but a t and above1 a concentration of 0.01 per cent.afalling off in activity occurred. Sodium nitrate, on the otherhand, caused distinct increase in the amount of fixation.The effect of salts appears to be specific, and not osmotic.Calcium sulphate markedly stimulates nitrification, as has beenobserved before under other conditions; so also' did sodiumchloride, magnesium carbonate, and sodium carbonate 25 in appro-priate concentrations, although beyond the proper limits harmfuleffects have been produced. On the other hand, calcium carbonatewas found to be toxic, an observation that deserves to be followedup in view of the known beneficial effect of this substlance onfe'rtility.The effect of nitrates on soil organisms is of special importance,because of the possibility that they may serve as nut,rients.Thenitrates of sodium, magnesium, manganese, calcium, and ironactively stimulate nitrogen-fixing organisms. They also stimulatecertain organisms which assimilate nitrat'es, transforming thenitrogen into protein ; thus, in the conditions of these experiments,they actually led to1 a decrease of nitric nitrogen in the soil.Further, Hutchinson and Clayton have found that they increasevery considerably the growth of the spirochzts which decomposecellulose. On the other hand, sodium nitrate appears to depressnitrification,26 but as i t caused a loss of nitrate from the medium,24 T. M. Singh, Sod Sci., 1918, 6, 463 ; A., i, 374.25 T. M. Singh, Zoc. cit., but Greaves obtained no stimulating action with26 T.M. Singh, Soil Sci., 1918, 6, 463; A., ii, 374.sodium carbonateAGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 179the effect may have been simply the, stimulation of nitrate-assimilating organisms already ref erred to.Numerous investigations have been made in the United Statesinto the effect of the chains of bacterial processes on the mineralconstitsuents of the soil. The nitrification of dried blood and thebacterial oxidation of sulphur in mixtures of sand and felspar areaccompanied by an increase in the amount of water-solublepotash; 27 the increase, however, is considered to be brought aboutby the salts formed, especially by ammonium sulphate, rahher thanby direct action of acid on the insoluble potassium compounds.Previous investigation has shown that both these changes, whencarrie'd out in culture solution,28 increase the solubility of rockphosphate.It is now shown 29 that no solvent action on phosphateaccompanies nitrification in the soil, nor did any accompanybacterial oxidation of sulphur, excepting in the case1 of acid soils.Ammonium sulphate, however, has little' or no solvent action onrock phosphatel, so that on the author's hypothesis the facts areexplicable.These secondary actions of substances on soil constituents havebeen invoked to explain some of the curious effects produced whenmixtures of fertilising constituents are used.30 Instances arequot'ed where an insoluble phosphate by itself was less effective asa fertiliser than a soluble phosphate, although on the addition ofsulphate of ammonia it became equally effective. There is somedisagre'ement as to the precise facts, but t-he possibility of thesesecondary actions seems worth exploring.An interesting suggestion has been made31 for the practicalutilisation of the bacterial oxidation of sulphur in soils.Potatogrowers prefer an acid soil, because acidity, whilst not unfavour-able to the potato crop, is entirely unsuited to the scab organism,32one of its worst pests. Ot,her crops of the rotation, however,especially clover, are injured by the acidity. It is pro-posed, therefore, that a dressing of 300 t'o 1000 lb. per acre ofsulphur should be made before planting the potatoes, to ensure therequisite degree of acidity, and, after the1 crop is removed, sufficientlime can be added t o ensure neutrality.An important addition to our knowledge of the soil protozoa has27 J.W. Ames and G. E. Boltz, Soil Sci., 1919, 7, 183.28 Hopkins and Whiting (Illinois Bull., 1916, No. 190, 395) state that 115parts of phosphorus become soluble in water for each 56 parts of nitrogenoxidised. These experiments were done in culture solution.29 J. W. Ames and T. E. Richmond, Soil Sci., 1918, 6, 351.30 J. E. Greaves and E. G. Carter, ibid., 1919, 7, 121 ; A., i, 564.31 J. G. Lipman, ibid., 181.s2 L. J. Gillespie and L. -4. Hurst,, ibid., 1918, 6, 219 ; A . , i, 115180 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been made by D. W. C ~ t l e r , ~ 3 who has shown that these organismsadhere firmly t'o the soil particles up to a certain number per gramof soil, beyond which they no longer adhere, but can float away.Each of the soils examined had a definite saturation point.I f a soil is shaken with suspensions of protozoa of varying con-centrations, the absorption is complete in all cases where thenumbers are below the saturation capacity? but it is not extendedwhen the numbers rise beyond.Thus the phenomenon exactlyresembles in its sharpness the neutralisation of an acid with a base,and differs entirely from adsorption? which is not, in general, com-plete, but depends on the relative masses of the absorbed andabsorbing substances.The general biochemical conditions in the soil are frequentlyunder investigation as being equally important to the soil organismsand to the growing crop.Among the most important is the reac-tion of the, soil, whether Ecid or neutral, the acidity being measuredby the hydrogen-ion concentration and by some titration method.A large number of titrat<ion methods have been devised and tested,and new series of tests and new modifications have recently beenproposed.34 Criticisms of the sugar method described in last year'sReport have also been made.35 The soil acidity is found t o varywith the moisture conditions of the soil, but the variation isattributed to chemical rather than physical changes.36Aremarkable effect of farmyard manure on the clover crop will bementioned later. Another and wholly different effect is to reducethe harmful action of salts in alkali soils; 37 this is attributed t oadsorption of the salts by the colloidal substances of the farmyardmanure.A further important, effect, no doubt colloidal also, of organicmatter is to increase the water-holding capacity of the soil. Thisis clearly marked at Rothamsted, where 15 tons of farmyardmanure are added annually t.0 certain plots; it does not show, how-ever, in the Minnesota investigations, where only 5 tons of manurehad been added each four year~.~8I n view of these and other important properties, various meansof estimating the so-called humus in soil have been suggested from33 J .Agric. Sci., 1919, 9, 430.34 C. J. Lynde, Trans. Roy. Soc. Caizada, 1918-9, [Zl, 12, 111, 21 ; A.,ii, 376; L.P. Howard, Soil Sci., 1918, 6, 405; R. E. Stephenson, Soil Sci.,1918, 6, 37 ; E. T. Wherry, J. Washington Acad. Sci., 1919, 9, 305 ; A., i, 428.The supply of organic matter is of considerable importance.35 L. T. Sharp and D. R. Hoagland, Soil Sci., 1919, 7, 186.36 S. D. Conner, J. Agric. Res., 1918, 15, 321 ; A., i, 115.3 7 C. B. Lipman and W. F. Gericke, Soil Sci., 1919, 7, 105.38 F. J. Alway and J. R. Neller, J . Agric. Res., 1919, l6,-263AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 18 1time to time, a rapid test being the amount of chlorine liberatedfrom a solution of sodium hypochlorite.39The supply of mineral matter is of recognised importance, butless work than. usual has been done in recent years. The method ofusing weak acids for analytical purposes, general in this country,has been found satisfactory40 in Germany also.It has been shownthat the unsuitability of certain Minnesota prairie soils to legu-minous crops, vaguely attributed to (‘rawness,” is simply due tolack of mineral nutrients.41A study has been made! of the marked changes produced byheating the’ soil on its properties as a medium for the growth ofplants and organisms.@’Soil Constituents and So,il Siwveys.The soils of North Wales have been studied in detail during thepast few years.43 The sedentary soils of the carboniferous andmillstone grit formations, which occur in the drier parts of theregion, resemble those found elsewhere in t,hat the coarsest fractionsare the! richest in silica; they are, however, quite unlike thesedentary soils of the palzozoic series in the wetter districts wherethis rule does not hold.The organic phosphorus compounds 44 of soil and the aldehydes 45present in the soil have received some attention.Of the inorganic constituents, tthe clay is distinctly unfortunatein its name, inasmuch as the same word is used in a wholly differentsense by the ceramic investigators, whose work otherwise ought t obe very helpful t o soil investigators.46The chief chemical property of (‘ clay ” (using the word, not inthe ceramic, but, in the soil investigator’s sense) is its reactivitywith salts; i t readily exchanges bases.The action is not yet fully39 L. Lapicque and E. Barbe, Compt. rend., 1919, 168, 118 ; A., i, 116.4o 0.Lemmermann, A. Einecke, and L. Fresenius, Landw. Vtrsuchs-Stat.,1916, 89, 81 ; A., i, 616 ; 1 per cent. citric acid was used for estimationof the phosphate, and 10 per cent. hydrochloric acid for estimation of thepotash.41 P. R. McMiller, Soil Sci., 1919, 7, 233.42 J. Johnson, ibid., 1.43 G. W. Robinson and C. F. Hill, J. Ayric. Sci., 1919, 9, 259.44 C. J. Schollenberger, Soil Sci., 1918, 6, 365 ; A., ii, 168 ; R. S. Potter and45 J. J. Skinner, J. Fsranklin Inst., 1918, 186, 165, etc.46 See, for example, R. E. Somers (J. Washington. Acad. Sci., 1919, 9, 113),for a mineralogical examination of “ clay ” corresponding with “ fine sand ”and “ silt ” in soil work.R. S. Snyder, ibid., 1918, 6, 321 ; A., i, 142182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.understood, and consequently soil investigators watch with interestthe work done on basic exchange in zeolites, silicates, etc., to seewhat light, if any, is thrown on their own problems.Among suchinvestigations may be mentioned those of Ra~llann,~T who fullyrealism the conditions obtaining in the soil.The various methods of soil analysis have been discussed andcompared by Richter .4*Rain.For many years agricultural chemists were very interested inthe composition of rain-water, particularly in the amount ofnitrogen compounds present, these being supposed to contribute tothe nutrition of the crop. It is now recognised that the quantitiespresent are too insignificant to exert any .appreciable effect, andthe long-continued series of analyses a t Rothamsted have been dis-continued.The results have been summarised .49 The ammoniacalnitrogen amounts on an average to 0.405 part per million, corre-sponding with 2.64 lb. per acre per annum; the yearly fluctuationsin lbs. per acre follow the rainfall fairly closely. The nitricnitrogen (which includes nitrites) is on an average one-half of thisamount, namely, 1.33 Ib. per acre per annum. There is a markeddifference in composition between summer and winter rainfall,suggesting that they may differ in their origin; the winter rainresembles Atlantic rain in its high chlorine and low ammonia andnitrate content; the summer rain is characterised by low chlorinebut high ammonia and nitrate content, suggesting that i t arises byevaporation of water from the soil and condensation a t higheraltitudes than in the case of winter rain.Whilst the subject hasno obvious agricultural interest, there is the possibility of a usefulcontinuation of the work in connexion with atmospheric pollution.It is interesting to note that the quantity of ammonia and nitratecollected in the rain at Ottawa50 is of the same order as a tRothamsted, namely, 0.46 part per million of free ammonia, 0.138as albuminoid ammonia, and 0.277 as nitrite and nitrate, making,with the organic nitrogen, 6-58 lb. per acre of nitrogen, as againsta little more than 5 a t Rothamsted. Very similar results wereobtained at Cornell,51 where the average free ammonia was 0'407,4 7 E. Ramann and A.Sprengel, Zeitsch. anorg. Chem., 1919, 105, 81 ; A.,i, 615. See also G. Kornfeld, Zei88ch. EZeEtrochem., 1917, 23, 173; A.,ii, 459 ; I. Zoch, Chemie der Erde, 1915, I, 55 pp. ; A., ii, 470.4 8 G. Richter, Int. Mitt. Bodenlcunde, 1916, 6, 193, 318 ; A., 1918, ii, 280.4 9 E. J. Russell and E. H. Richards, J . Agric. Sci., 1919, 9, 309.5 0 F. T. Shutt and R. L. Dorrance, Trans. Roy. SOC. Canadu, 1917-18,61 J. E. Trieschmann, Chem. News, 1919, 119, 49 ; A., i, 511.[iii], 11, 63 ; A., i, 116AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 183the albuminoid ammonia 0.366, the nitrate 0.255, and the nitrite0.018 part per million respectively.Fertilisers and Xanures..I n the main, investigations this year have been concerned withdetails of importance to the technical chemist and the agriculturaladviser; they are dealt with in the Report to the Society ofChemical Industry, and need not, therefore, be discussed here.The organic manures have been under investigation, and one ortwo conclusions of general interest have emerged.Farmyardmanure has been shown52 t o exert a beneficial effect on the growthof clover, appareatly greater than its composition leads one t oexpect; this result may be related Lo the life-cycle of the organism,which is now under investigation.Other organic substances used as manure include rape cake (theresidue left after the extraction of oil from rape seed); this con-tains a considerable proportion of plant protein, the decompositionof which in the soil gives rise to nitrates.It is often supposedthat plant or animal proteins must necessarily be more useful asfertilisers tlhan nitrates ; this anticipation does not appear to hecorrect.53An investigation has been made into the power of calciumsulphate to “fix” part of the ammonia liable to be lost frommanure heaps ; 64 whilst this shows that some degree of conservationmay be possiblel, it does not throw light on the1 fertilising value ofthe mixture of farmyard manure and calcium sulphate. I n thecase of liquid manure, gypsum was only partly effective.55Sulphates are not regarded as fertilisers in this country,although considerable quantities are, as a matter of fact, appliedto crops in the form of ammonium sulphate and superphosphate.It is known, however, that sulphur is essential t o crops, and aninteresting case is recorded from Oregon 56 of soils respondingmarkedly to sulphur and sulphates, larger returns having beenobtained from gypsum than from lime.Both sulphur andsulphates gave increased yields of oats, rape, and red clover, andin the latter case they led t o more nodule formation.6H E. J. Russell, J . Bd. Agric., 1919, 26, 122.53 Idem., ibid., 228.54 F. E. Bear and A. C. Workman, Soil Sci., 1919,7. 283 ; A . , i, 511.6 5 0. Lemmermann and H. Weissmann, Landw. Jahrb., 1918, 52, 297.6 G H. Q. Miller, J . Agric. Res., 1919, 17, 87 ; A., i, 510184 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.Z’he ,4bsorption of Nzitrients by t h e Plant Roots.The nutrient materials derived from the soil are absorbed bythe root, and numerous investigations have been made into themechanism of the process.W. Stiles and F. Kidd57 measured thechanges in conductivity of the solution of a salt presented to theplant tissue; these were taken to measure the rate of absorption.Absorption a t first was approximately proportional to the externalconcentrations ; as it progresses, however, it tends towards an equil-ibrium expressible by the ordinary adsorption equation. Neverthe-less, the authors wisely redrain from regarding the whole processas necessarily an adsorption.A full discussion of this interesting subject. lies outside the scopeof the present report; i t has, however, formed the subject of severalother investigations.58Plant Nutrition,It has always be’en supposed that green plants required onlyabout a dozen elements for perfect nutlrition, namely, carbh, hydro-gen, oxygen, nitrogen, phosphorus, sulphur, potassium, calcium,magnesium, sodium, and iron.P. Maz6, during the past few years,has been adding to this list, and claims as a result of his recentinvestigations 59 that traces of the following are required in addi-tion : boron, fluorine,, iodine, chlorine, silicon, aluminium, man-ganese, and zinc. On the other hand, he found no necessity fororganic substances, although some of them were helpful. Thetrace6 required must be very small, since it is a common experiencea t Rothamsted to obtain a copious and normal growth of barleyin water cultures containing the purest obtainable salts of theconventional nutritive elements.Even i f they are not essential,t%he elements in Maz6’s list appear to be beneficial in certaincircumstances, according to evidence which is steadily accumu-lating ; dhring this year, for instance, investigations have been pub-lished showing the beneficial effects, under certain conditions, ofcompounds of fluorine,gO silicon,61 aluminium,62 manganese,s35 7 Proc. Roy. SOC., 1919, [B], 90, 448 ; A., i, 240. The carrot proved verysuitable for the purpose.58 M. Williams, Ann. Bot., 1918, 32, 591 ; A., i, 59 ; W. J. V. Osterhout,J. Biol. Chem., 1918, 36, 485, 489, 557 ; A., i, 111, 112 ; F. E. Lloyd, ! I h n s -Roy. SOC. Cunuda, 1917-8, [iii], 11, 133 ; A., i, 111.5 9 Arm.Inst. Pasteur, 1919, 33, 139 ; A., i, 304.6o A. Gautier and P. Clawmann, Compt. rend., 1919, 168, 976 ; 169, 11562 J. Stoklasa and others, Biochem. Zeitsch., 1918, 91, 137.63 Idem., loc. cit. ; E. P. Deatrick, Cornell Uni?:. Agric. Exp. Sta. Mem.,A . , i, 371, 512. 61 D. S . Jennings, Soil Sci., 1919, 7, 201.1919,lg. 371 ; A., i, 428AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 185barium, and strontium.64 I n addition, traces of iodine have beenfound in plants growing under natural conditions.65Copper appears to be widely spread in the vegetable kingdom,and analyses have been made to determine how much is presentin soil. About 2 to 5 milligrams per kilo. of fine earth were foundin normal soils, but much higher amounts-200 or 250 milligramsper kilo.-in vineyard soils, where copper sprays are used.It isnot suggested that the copper is beneficial, although small amountsprobably do no harm.66 The suggestion that selenium is a definiteconstituent of animals and plants, brought forward two years ago,67has now been calleld in question.68An important development of the scientific principles ofmanuring was made some time ago by E . A. Mitscherlich in theintroduction of efficiency factors (U'irkuiigsfactoren) of manures.It is now shown69 that in the1 case of mixtures of fertilisers, thefactors remain constant so long as the constituents are withoutmutual action, but they vary as soon as interaction takes place.It has further been shown that, in the case of two nitrogenousmanures, namely, ammonium sulphate and sodium nitrate, the ratioof the respective efficiency factors is the same whether they arecalculated for corn or for straw.Between nutritive effects and toxicity the margin seems t o benarrow, and almost all of the elements essential to plant nutritionare capable of producing toxic effects under other conditions.Evenso definite and essential a plant nutrient' as a soluble phosphate isreported to be sometimes poisonous. Moreover, these effects haveno relation to the neeids of the plant; on the contrary, it has beensuggested that substances of which a plant stands most in need arecapable of exerting the greatest toxic effect. Thus, excem ofsoluble1 phosphate injures buckwheat, but, apparently not oats; yetbuckwheat is more delpendent upon phosphatic manure than oats.70Lupins afford a similar case; they greatly need lime, and yet areeasily affected adversely by it.So ammonium sulphate, a recognised and important fertiliser, is64 J.S. McHague, J . Agric. Res., 1919, 16, 183; A., i, 303.6 5 E. Winterstein, Zeitsch. physiol. Chem., 1918, 104, 54 : A . , i. 190.6 6 L. Maquenne and E. Demoussy, Compt. rend., 1919,169, 937.6 7 T. Gassmann, Zeitsch. physiol. Chem., 1916, 97, 307 ; 1917, 100, 182:6 8 R. Fritsch, ibid., 1918, 104, 59 ; A . , i, 191.6 9 Landw. Jahrb., 1918, 52, 279 ; A., i, 143.A . , 1916, i, 772 ; 1917, ii, 540.An account of these factorsis given by E. J. Russell, " Soil Conditions and Plant Growth," 3rd Edition,1917, pp. 23 et seq.T.Pfeiffer, W. Simmermacher, and M. Spangenberg, Landw. Versuchs-Stat., 1916, 89, 203186 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.capable under certain conditions of exerting toxic effects on theplant, and ammonium chloride is said to be even more toxic.71 I npractice, these effects are not obtained unless the soil is acid.It is, hoGever, particularly charactelristic of all the growth-pro-moting elemenh, other than the conventional nutritive elements,that their good effects are obtained only within very narrow limits,above which harmful effects are produced.This narrow margin between toxicity and growth-promotionmakes it very difficult' to ascertain with certainty the effects of someof the constituents of the plant. It is not difficult to show in watercultures the toxicity of vegetable alkaloids and related substancesto young plants.72 These are not, however, the conditions underwhich the substances act in the plant, and i t is unsafe to argue thattoxicity in water culturw proves toxicity in natural conditions.Some are known under other conditions to increase growth; thus,guanidine was found in these experiments to be toxic, yetl otherinvestigators have found it.beneficia1.73 It would, however, beequally unsafe to draw the converse deduction and, becausenutritive substances can produce toxic effects, assume that toxicsubstances can therefore exert growth-producing effects.Plant Poisons.The action is further complicated by the fact that two substancesacting together may behave very differently from eibher actingseparately .74Two practical problems arising out of toxicity have been dealtwith this year.(1) Ejfect of Lead Compounds on Vegetation.-Considerabletrouble has been experienced in the past through the refuse fromlead minels washed down on to agricultural land.J. J. Griffith75has made a careful study of the; effects produced in Cardiganshire.Leguminous crops appear t o suffer most, although all were affected,and in the case of root crops so much lead or zinc compound somet-times adhered to the roots as to cause injury to the animals eatingthem. A heavy dressing of lime afforded the best remedy.71 H. G. Stjdsrbaum, Kongl. Landtbruks-Akad. Handlingar, 191 7, 56,537 ; A., i, 60.72 Compare G.Ciamician and C. Ravenna, Atti R. Accad. Lime& 1919,[v], 28, i, 13 ; A., i, 241. For an investigation into the effect of poisonousorganic substances on germination and seedling growth, see I. Traube andH. Rosenstein, Biochem. Zeitmh., 1919, 95, 85 ; A., i, 509.73 L. Hiltner and M. Kronberger, Chem. Zentr., 1919, 90, i, 1039.74 Compare W. E. Tottingham and A. 5. Beck, Plant World, 19, 359 ; A.,7 j J. Agric. Sci., 1818, 9, 366,i , 510AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 187( 2 ) The Poisonous Effects of Coal Gas on Plants.--It is shownthat the toxicity is a positive effect, and is not due to displacementof oxygen, but is associated with the constituent to which thecharacteristic odour of coal gas is due. When this is removed, thetoxicity ceases.76 Subsequent experiments77 indicated hydrocyanicacid as the most probable agent.The Composition of Plants m a ! t h e Changes d i w i q Gmwtli.The composition of the1 plant taken as a whole alters continuouslyduring the entire period of growth, but the change, appears to beon definite lines.For this particular purpose the plant may beregarded as made up of two parts, namely, the framework and thecontained material. Each of these is tolerably constant in corn-position for a given plant, the variations being within fairly definitelimits, but the relative proportions of framework and containedmaterial vary considerably, although quite regularly, a t differentperiods of plant growth.The process of ripening and seed formation then consists in thetransfer of the cell contents (or a part thereof) t o the seed heads.Certain plants-wheat, mangolds-have1 in the past been studiedin some detail at Rothamsted, and the conclusion has been drawnthat whatever the Circumst~ances, so long as the plant growsa t all, i t will continue to make material of the same generalcharacter, and to send this into the framework or the seed heads.During the present year, the course of the growth processes in thesorghum plant has been studied in the United States,78 and theresults indicate that the plant during the1 earlier part of the seasonbuilds up its cellular structure of fibre, protein, and mineralmaterial, whilst in the later stage it' fills up these tissues withcarbohydrates-starch in the seed and sugar in the stalk.Noevidenoe was found that the leaves are deprived of carbohydratesto supply the stalk. Maturation of t<he seed heads consists almostentirely in the filling out of a fibre and protein framework withstarch.All the plant constituents, whatever their nature, are derived inthe plant from the sugar produced by photosynthesis, and thenitrates, phosphates, and other inorganic substances taken up bythe roots. Little is known of the mechanism of the changesinvolved, and thelre is still much to be learnt of chemical constitu-76 C. Wehmer, Ber. Deut. bot. Ges., 1918, 36, 140 ; A., i, 114.7' C. Wehmer, ibid., 460; A., i, 302.78 J. J. Williams, R. M. West, D. 0. Sprietstersbach, and G. E. Holm,J . Agric.Res., 1919,!18, 1188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion of the substances themselves. Light is certainly essential, andthe diff erent wavelengths have different effective values.79It has been supposed, and possibly correctly, that formaldehydeis the first product of photosynthesis, but the evidence is renderedincomplete by the circumstance that formaldehyde may perhapsarise from the decomposition of chlorophyll.80The first substance detectable with certainty in the chain ofphotosynthesis is sucrosel, which is subsequently hydrolysed t odextrose and lzvulose. The next stages, however, are involved inconsiderable obscurity. It has been urged that the dextrose is usedup t o form cell contents or for purposes of respiration, whilstthe lzevulose is used for making the framework.Unfortunately,the amount of lzvulose cannot be estimated with any degree ofaccuracy,81 so that its movements cannot be followed. It has,indeed, been claimed this year that the ratio dextrose/lzevulose canbe determined; it is claimed, also, that this ratio is less than unityin the parenchyma of the leaf, but increase8 in the stem.82 If thiswere true, i t would be consistent with the1 view that dextrose1 aloneis used up for respiration, since respiration is greater in the leafthan in the stem. It does not appear, however, that the objectionsof Davis to the analytical process have really been met. Notwith-standing the unsatisfactory nature of the evidence, however, it? isstill permissible to think of the lzvulose as being concerned mainlyin building framework and the dextrose mainly in providingmaterial for cell contents and respiration.Little has been added this year t*o our knowledge of the frame-work.A paper has appeared83 on the furfuroids (related to cellu-lose) of sugar beet, but it is mainly of analytical interelst; it dealsalso with the pectoses, the supposed cementing material binding theframework together. An attempt has been made to ascertainwhether the marked effect of potassium fertiliser on grass and cerealstems is due to any stiffening of the1 framework. Microscopic es-amination, however, failed to reveal any difference in structure; y4the effect is presumably to be attributed to differences in turgidity.Much morel work has been done on the cell contents.Thedextrose generated from sucrose, is not usually stored as such, butis generally converted into starch. This, however, does not remainas starch, but is again hydrolysed, and may again be regenerated79 A. Ursprung, Ber. Deut. bot. Ges., 1918, 36, 73, 86 ; A., i, 112.so W. J. V. Osterhout, Amer. J . Bot., 1918, 5, 511 ; A., i, 597.s2 H. Colin, Compt. rend., 1919, 168, 697 ; A., i, 241.8* 0. N. Purvis, J . Agric. Sci., 1919, 9, 338.W. A. Davis, J. Agric. Sci., 1916, 7, 327.R. Gillet, Bull. Assoc. Chim. Xucr., 1918, 35, 93 ; A., ii, 302AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 189either from dextrose or from some of the other substances producedin the cell. A considerable number of sugars appear to be capableof conversion into starch in a t least certain plant cells; thus,Spirogyru in water free from carbon dioxide can form starch fromdextrose, lzvulose, galactose, raffinose, methyl alcohol, glycerol, orethyl acetate in the presence of dipotassium hydrogen phosphateand formaldehyde.It does not, however, form starch under theseconditions from lawulose, sorbose, arabinose, xylose, rhamnose, andother substances.85 Aspergillus has similar wide powers of pro-ducing starch under certain conditions.86 Of course, these sub-stances are not necessarily all found in the plantl cell, but some ofthem are widespread; carrots have been shown t o contain mannitoland dextrose, whilst green peas contain mannitol, dextrose, 1;evu-lose, and glycuronic acid.87 Mozeover, starch is not always found;in some cases, the product is inulin or the very similar inulenin.g8The carbohydrate occurring in lichens has also been studied,g9chiefly, however, with the view of obtaining a ferment'able sugar.The gums of the sorghum plant have been found to consistof complexes of galactose and pentosans with about 20 per cent.of mineral matter, chiefly calcium, magnesium, and potassium.g0Some of the plant constituents are simpler in composition thanthe sugars, and may be regarded either as degradation products ofdextrose or lzevulose, or as accompanying products in the synthesisof sucrose.A suggestedimprovement in the method of identifying this subst+ance in plantsconsists in substituting ferrous ammonium sulphat'e 91 for thepotassium salts now ofteln used.For the purpose of localising theoxalat4es, a highly concentrated solution of the ferrous salt isinjected into the plant by means of an air pump, when precipita-tion of the ferrous oxalate occurs within the cell in which the acidoccurs. Other methods suggested have involved precipitation withsaturated alcoholic sodium or potassium hydroxides, lead acetate,and barium chloride.92The presence of a salt of aconitic acid in the juice of the sugar-cane seems to be established.9s The sorghum plant! also containsOne of the commonest is oxalic acid.R 5 T. Bokorny, Biol. Zentr., 1916, 36, 385 ; A., 1918, i, 366.8 6 F. Boas, Ber. Deut. bot. GES., 1919, 37, 50 ; A., i, 508.8 7 E. Busolt, J .Landw., 1916, W, 357, 361 ; A., i, 564.88 E. Couvreur, Compt. rend. SOC. biol., 1918, 81, 40 ; A . , 1918, i, 366.89 E. Salkowski, Zeitsch. physiol. Chem., 1919, 104, 105 ; A., i, 242.J. J. Williams, R. M. West, D. 0. Sprietstersbach, and G. E. Holm,J . Agric. Res., 1919, 18, 1.91 N. Patschovsky, Ber. Deut. bot. Qes., 1918, 36, 542 ; A., i, 303.92 H. Molisch, Flora, 1918, 11-12, 60 ; A., i, 192.93 C. S. Taylor, T., 1919, 115, 886190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.aconitic acid in addition t o malic, citric, tartaric, and oxalicacids. 94On the other hand, the simplest of all organic acids, formic acid,is of rare occurrence; its presence has been demonstrated in thehairs of stinging nettles,gj but i t is not usual elsewhere.The organic phosphorus reserve compound of plants has beenstudied in some detail in France, and its identity apparently estab-lished.I n the first place, crystalline salts were isolated, which onanalysis gave the formula C,H,,OnP,Na,,(or Na&a,),44H,0.g6Further investigation showed that three molecules o t water wereso strongly retained that they could not be removed except bydecomposing the compound; the formula was then altered toC6H,0,P6Na,,,4 7H@. 97 This indicated a hexose hexap hospha te,and examination showed the substance was really an inositol hexa-phosphate. The evidence was clinched by synthesising inositolhexaphosphate by heating inositol with phosphoric acid in thepresence of phosphoric oxide at 120-130° for three hours, andthen showing that the double sodium calcium salt had identicalcrystallographic propert-ies with that prepared from the naturallyoccurring substance.98Besides the sugars and the phosphorus compounds, there arelarge numbers of other plant constituents, some of which arechemically simple and others are not.There is a steady increasein chemical knowledge of the complex plant substances. Fortu-nately, the investigations of Willstatter on chlorophyll arecontinuing.99Another group of constituents at least as complex as chlorophyllare the chromatins. Investigation of them substances is difficult,and little has been added to our knowledge during the year. It isnow stated that the substance previously described by Dangeard asmetachromatin in higher plants is not comparable with the meta-chromatin of fungi, but is a phenolic compound capable of beingconverted into anthocyanin.1 A large body of constituents is,~34 J.J. Williams, R. M. West, D. 0. Sprietstersbach, and G . E. Holm,J. Agric. Res., 1919, 18, 1.O 5 L. Dobbin, Proc. Boy. SOC. Edin., 1918-19, 39, 137 ; A., i, 614.96 S. Posternak, Compt. rend., 1919, 168, 1216 ; A., i, 426.9 7 S. Posternak, ibid., 169, 37 ; A., i, 426 ; Society of Chemical Industry in98 S. Posternak, ibid., 138 ; A., i, 433.9 9 R. Willstatter, 0. Schuppli, and E. W. Mayer. Annalen, 1919, 418, 121 ;A., i, 448.For a discussion of the bearing of this work on the mechanism of assimilationsee R. Willstatter and A. Stoll ( B e y . , 1917, 50, 1777 ; A., 1918, i, 207) andK.Schaum (Ber., 1918, 51, 1372 ; A., i, 111).Basle, Brit. Pat. 130456 ; A., i, 504.1 A. Guilliermond, Compt. wnd., 1918, 166, 958 : A., 1918, i , 366AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 191however, proving more amenable to chemical treatment. Thetannins, wh'ich are very widely spread, have been studied by EmilFischer,2 and their relation to the mellowing of fruits has beediscussed by C. Griebel and A. Schafer.3Some new or little known glucosides have also been described,some occurring in the cotton plant4 and some in the orchid.5 Thesaponin occurring in lucerne has also been studied; its formula isgiven as C,,H,,O,,N; it is abnormal in that it contains nitrogenand does not haemolyse blood. Like other saponins, it poisons fish,but i t is said to act by preventing the diffusion of air into the water,and not in virtue of any special toxic property.6 Other saponinsinvestigated have been from the root of Platycodon grandi-@0rz~.m.7The substance indican is of special interest, because of its greattechnical importance in connexion with indigo.Davis claims thatthere is a marked need for phosphatic fertilisers in order to securea proper yield under Indian conditions.8 A new method of pre-paring indican from the indigo plant has also been described, andis said to be more rapid and complete than other methods.9From the agricultural point of view, the nitrogen compoundsare often more interesting than the others. It has been customaryto identify these by hydrolysis with hydrochloric acid and ex-amination of the products by the Van Slyke method.Whilst themethod has advantages, there is considerable evidencel that it breaksdown in particular mes.10The only safe plan is to isolate the protein and study it in aspure a state as possible. It is known that the protein is formed insome way from sugar and an inorganic nitrate, and an attempt1*has been made to express the course of the reaction. It is assumedthat the sugar reacts with nitrogen, phosphorus, and sulphurderived from inorganic salts to yield proteins; the bases of the salts2 E. Fischer and M. Bergmann, Ber., 1918, 51, 1760 ; 1919, 52, [B], 829 ;A . , i, 87, 278.Zeitsch. Nahr.-Genussm., 1919, 37, 97 ; A., i, 427.A. Viehoever, L. H. Chernoff, and C.0. Johns, J . Agric. Res., 1918, 13,Also E. E. Stanford and A. Viehoever, ibid., 13, 419 ;5 E. Bourquelot and M. Bridel, Compt. rend., 1919, 188, 701; A.,345 ; A . , 1918, i, 367.A., 1918, i, 367.i, 243.G. A. Jacobson, J . Amer. Chem. SOC., 1919, 41, 640; A . , i, 375.7 H. Oshika, Kyoto Igaku Zasshi, 1918, 15, 56 ; A., i, 427.8 Agric. J . India, 1919, 14, 21.B. M. Amin, Agric. Res. Inst. Pusa, Indigo PubZ., No. 5 ; A., i, 283.10 J. F. Brewster and C. L. Alsberg, J . Biol. Chern., 1919, 37, 367; A . ,l1 A. Meyer, Ber. Deut. bot. Ges., 1918, 36, 508 ; A., i, 210.i, 239192 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.are thereby liberated and neutralised by the organic acid producedin the leaves; the process is formulated thus:27C,H@, + 24Ca(NO,), + CaSO, + 25H,C20, =C162H262053N48S f 25CaC@, f 2010 -t 56H20.The interest of the agricultural chelmist in the constituents ofplants lies in their feeding value to meln and animals but especiallyanimals, and this depends on two types of compounds, the nutrients,of which large quantities are required, and the vitamines, neededonly in small amounts.Water-soluble vitamine has been found inthe bulb of the onion, the root of the turnip,l2 the fruit of thetomato, and the leaves, stem, and root of the beet. I n the case ofclover, lucerne, and timothy, the larger amount of vitsmine wasfound in the immature plant, which may help to account for thesuperior feeding value of the younger over the older grass.The antiscorbutic factor present in green peas is lost on drying,and hence dried peas and lentils are not as valuable in a dietaryas they might be.H. Chick and E. M. Delf have shown,13 how-ever, that the factor increases five or six times in amount when t'hepeas are soaked for twenty-four hours and then allowed to germinatefor forty-eight hours; the amount then becomes equal to that foundin green peas and potatoes, and greater than that in carrots orbeetroots.I n the case of wheat grain, the water-soluble vitamine appearsto be localised in the endosperm, but it is not uniformly distributedthere.The nutritive value of the constituents is more properly dealtwith by the physiologist than the agriculturist. Reference may bemade, however, to the extensive paper, just quoted, by Osborne andMendel on the nutritive value of the wheat kernel and its millingproducts .None could be found in t,he pure embryo.14The Mechmtism of the Reactions in t h e Plant.Although very little is known of the course of t<he reactions inthe plant, some knowledge has been gained of the conditions deter-mining them.I n the first place, the so-called mineral elements-potassium,calcium, phosphorus, etc.-are essential, although this fact is oftenoverlooked in attempts at reconstructing the plant processes.l2 T.B. Osborne and L. B. Mendel, J. Biol. Chem., 1919, 39, 29 ; A., i, 510.l3 Biochem. J . , 1919, 13, 199.l4 T. B. Osborne and L. B. Mendel, J. Biol. Chem., 1919, 37, 557 ; A . ,i, 298AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.193Analyses of the plant ash are frequently niade,lj and, whilstl thefigures are not at, present, illuminating, they will presumably someday find an interpretation. Oiie instance only need be quoted,the case of the ash of the spinach plant grown under con-ditions of high manuring.16 The constituents fall into1 two groups:those present in quantity but varying little, whatever thef ertilisers added t o the soil-lime, magnesia, manganese, alumina,iron, phosphorus, and sulphur-and those that show great fluctua-tions in t,he quantity present, including silica, potash, and soda.The variations sometimes, but, not always, are in the same directionas those1 in the soil.The ash constituents sometimes precipitate out' as the result ofinteractions in the plantq.The second important consideration is that the processes arecarried on in the main by enzymes.A little reflection will showthat this is necessary, since the ordinary means of expeditinga reaction by rise of temperature or of concentrationare inapplicable in the growing plant; a catalyst is thereforeessential.A discussion of the enzymes of plants mould be outside the scopeof this Report; it is possible only t o indicate some of the workcarried out' during the year. Undoubtedly the paper of mostgeneral interest is one describing an attempt by Willstatter andStoll to work out the constitution of peroxydase, using the materialobtained from thel horse1 radish. They endeavoured to prepare purespecimens of the enzyme1 so as t o find out whether it, is a singlesubstance or a system of co-operating substances, whether a metalis an integral part of the enzyme, and what atomic groups areresponsible for enzymic activity.18 The enzyme does not, appear tobe hopelessly complex in structure; i t seems t o consist chiefly of anitrogenous glucoside containing a pentose arid a moleculaiquantity of another sugar, probably a hexose.Mineral matter isalso present, but iron, a t any rate, scarcely seems necessary f o r theeffective action of the enzymel.Other papers of interest include1 one on the oxydases of sugar-l5 See, for example, L. Leroux and D. Leroux, Ann. Chim. anal., 1919,[ii], 1, 2 0 7 ; A., i, 563; A. Lacroix, Compt. rend., 1918, 166, 1013; A., 1918,i, 366.l6 R.H. True, 0. F. Black, and J. W. Kelly, J . Agric. Res., 1919,16, 15.l7 A. Wichmann, Proc. K . Akad. Wetensch. Amsterdam, 1919, 21, 968 ;A., i, 564 (phosphates) ; also H. Molisch, Uer. Deut. hot. Gcs., 1918, 36, 277,474 ; A., i, 113, 242 (silica).R. Willstatter and A. Stoll, AnnuZen, 1915, 416, 21 ; A., 1915,i, 555.REP.-VOL. XVI. 194 ANNUAL REPORTS ON THE PROGRESS OP CHEMISTRY.cane,19 of the pear and the potato,Z0 of seeds,21 and of fresh anddried vegetables22An attempt has been made to express the delgradation of starchunder the action of diastase.23The vegetable proteases have also belen investigated, and theproteinoclastic and peptoclastic action of leaves measured a tdifferent periods of growth.24One of the most characteristio reactions in the plant is tshe pro-duction of aminocacids by the interaction of sugar and nitrate.Presumably reduction takes place at some stage, and 0.Baudisch25has attempted to reproduce the reaction in the laboratory; he hasworked out a reduction which resembles the natural process in thatan iron salt and oxygen both take part. B. Moore has also inveeti-gated the early stages in the synthesis of nitrogen compounds.26Feeding Stuffs.Several investigations have been made on the feeding value t oanimals of green crops. Green maize has been studied to findout the cause of the loss of sugar which is known to occur soonafter the plant is cut. It, is suggested27 that this loss is only inpart due t o respira,tion; most of it is attributed to condensationto form more complex substances, especially starch.It is knownthat the sugar content of green sweet maize falls off rapidly whenthe plant is cut.Certain green crops occasionally have harmful, and even fatal,effects on cattle. C. T. Dowel128 records a case in Oklahoma wheresorghum cut when 75 cm. high, a t a time of great drought,, killedno fewer than ten out of twelve cattle within an hour. Investiga-tion showed this to be a case of cyanogenesis. Itl was shown, holw-ever, that dried sorghum and mature sorghum are both safe feed-ing stuffs; if in a less mature sample there is any doubt about thepresence of the cyanogenetic glucoside, the ill-eff ects can be obviatedby giving some concentrated fe'eding stuffs. The explanation sug-l9 R.Narain, Agric. J. India, 1918, 47; A., i, 114.2o M. W. Onslow, Biochem. J., 1919, 13, 1 ; A., i, 361.21 W. Crocker and G. T. Harrington, J. Agric. Res., 1918, 15, 137; A.,22 K. G. Falk, G. McGuire, and E. Blount, J. Biol. Chem., 1919, 38, 229 ;23 M. Samec, Koll. Chem. Beihcfte, 1919, 10, 289 ; A., i, 472.24 E. A. Fisher, Biochem. J., 1919, 13, 124; A., i, 464.25 Ber., 1919, 52, [B], 35, 4 0 ; A., i, 237, 238.2 G PYOC. Roy. Soc., 1918, [B], 90, 158; A., 1918, i, 365.27 C. 0. Appleman and J. M. Arthur, J. Agric. Re$., 1919, 17, 137.33 llhid., 16. 175.i, 110.A., i, 426AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 195gested is that the dextrose and maltose produced by salivary diges-tion prevent liberation of the hydrocyanio acid.A common method of preserving green food over the winter isto cut it up and store it under amrobic conditions in a large vatcalled a silo; the product is known as silage.The sugars rapidlychange to acetic and other fatty acids, and a certain amount ofhydrolysis of the proteins takes place, but after the first rapidreactions there is little subsequent change, and the material keepsall through the winter. More products are periodically found inthe silagel; this year, acetylmethylcarbinol has been detected insorghum silage.29 Analyses have been made of the mixture occur-ring in ensiled cabbage, or sauerkraut .30Agricultural chemists have long tried to solve the problem ofevaluat'ing the fibre in feeding stuffs, the conventional method ofsuccessive acid and alkali treatment suffering from certain dis-advantages ; in particular, it dissolves some material which theanimal cannot digest. A new method, based on the absorption ofchlorine by the fibre, is claimed to give satisfactory results.31Another analytical problem as yet unsolved is to discriminatebetween one nitrogen compound and another in a feeding stuff.The Van Slyke method has obvious advantages, although, as alreadypointed out, it is liable to fail in dealing with plant pro-ducb. Two improvements have been effected32: (1) p r eliminary extraction, first with ether and thea with cold absolutealcohol, to remove non-protein substances that interfere with thereaction, and (2) reduction in the amount of humin nitrogen formedduring the reaction. It is claimed that these improvements putthe method on a much more satisfactory basis.The hydrogen electrode has been used for determining the acidityand the titratlable nitrogen in wheat. The process is not quitesimple, as the substances in the solution formed when wheat is ex-tracted with water are not ionised until an alkali has beenadded.3329 W. G. Friedemann and C. T. Dowell, J . I d . Eng. Chem., 1919, 11, 129 ;30 V. E. Nelson and A. J. Beck, J . Amer. Chem. Soc., 1918, 40, 1001 ; A.,31 P. Waentig and W. Gierisch, Zeitsch. physiol. Chem., 1918, 103, 87;32 H. C. Eckstein and H. S. Grindley, J . Biol. Chem., 1919, 37, 373; A.,33 C. 0. Swanson and E. L. Tague, J . Agric. Res., 1919, 16, 1 ; A., ii, 176.A., i, 244.1918, i, 364.A., ii, 173.ii, 204.a 196 ANNUAL REPORTS ON THE PROGRESS Ol? CHEMISTRY.Insecticides and Fungicides.Investigation has been made into the composition of Burgundy~ixture,34 a well-known and very useful copper spray, and of therulphur washes.35 I n addition, there has been some work on theuse of formaldehyde vapour for seed disinfection,36 and of chlor-picrin37 for the killing of insects. The investigation of thechanges in composition undergonet by arsenical fluids in cattle-dipping baths has led H. H. Green in South Africa t o the interest-ing discovery of certain bacteria capable of oxidising arsenites toarsenates, and of others capable of reducing arsenates t o arsenites.38E. J. RUSSELL.34 R. L. Mond and C. Heberlein, T., 1919, 115, 908.35 J. V. Eyre, E. S. Salmon, and L. K. Wormald, J . Agric. Sci., 1919,36 C. C. Thomas, J . Agric. Rcs., 1919, 17, 33.37 G. Bertrand, Brocq-Rousseu, and Dassonville, Compt. rend., 1919, 169,38 Union of S. Africa, 5th and 6th Reports, Veterinary Research, 1919, 593.9, 283.1059, 1428

ISSN:0365-6217    

DOI:10.1039/AR9191600171

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

CRYSTALLOGRAPHY.*THREE important advances are to be noted in the province of X-rayinvestigation, so far as concerns this Report. The first is the inde-pendent and almost simultaneous development, by Debye andScherrer in Germany and Hull in America, of an ingenious methodof investigating crystal aggregates ; this method was just mentionedin a previous Report, but. requires further notice now that theoriginal literature is available.The nature of the second advance can best be described by aquotation from Hull’s paper on the structure of iron.2 “It is verydiffimlt to conceive of any arrangement of point atoms which will[account for the experimental data]. We are forced, I think, t o lookfor the explanation in the internal structure of the atoms. If it isassumed that all the twenty-six electrons .. . are displaced from thecentre of the atom along the cube diagonals in four groups of 3,8, 8, 8 a t distances 1/32, 1/16, 118, and 114 respectively ofthe distance to the nearest atom, all the observed facts are accountedfor within the limits of experimental error.” It may be added thatthe same degree of penetration is characteristic of Debye andScherrer, who believe they have proved that salts are ionised in thecrystalline state.The third advance relates to the application of X-ray methods tothe study of amorphous substances, including colloids. Debye andScherrer have shown that aharcoal is really crystalline, andScherrer3 has proved that colloidal particles of silver and gold, asalso gels of silicic and stannic acids, are in reality ultramicroscopiccrystals.Apparently the only substances which may be neglectedThe Reporter regrets that owing to lack of space the consideration ofsome important mineralogical researches has had t o be postponed. It ishoped t o treat these adequately in the 1920 Report. Miss M. W. Porterhas kindly drawn some of the figures, and Mr. R. C. Spiller has assistedgreatly in the preparation of the manuscript, and the writer would take thisopportunity of thanking them for their kind co-operation.A. W. Hull, Physical Rev., 1917, [ii], 9, 84.3 P. Scherrer, Nachr. Ges. Wiss. G6ttinge?a, 1918, 96 ; A., ii, 274.19198 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.by the crystallographer are glass, and such organic materials ascelluloid, collodion, gelatin, albumin, cellulose, and starch.X-Ray methods of exploring crystal structure appear t o havereached a definite stage of development, so that a general apprecia-tion may not be altogether devoid of interest.One matter of detailmay be mentioned immediately. The face-centred lattice and itsderivatives (the diamond “lattice,” the blende and pyrites struc-tures, and so on) no longer wholly represent the family of cubicstructures, for there are now several examples of the cube-centred1 a ttice.The fifth and coiicluding volume of Groth’s inyaluable Chein-ische Krystallographie ” has appeared.It has, of course, long been known that silver or copper is just aseasily attacked by nitric acid as gold is resistant; also that anadmixture of gold (erroneously believed to be 25 per cent.--“ quar-tation”) protects silver or copper from action.As a result ofpatient tests with more varied reagents, Tammann has proved theexistence of reaction-limits, a t such definite metal concentrations asare expressible by simple multiples of 118. Apparent.ly, there areseveral degrees of nobility in the silver-gold and copper-gold seriesof alloys, the investigation of which has not only told us much con-cerning the chemical properties of a space-lattice, but has also ledto an interesting interpretation of a variety of properties, rangingfrom optical anomalies in mixed crystals t o the temper of a metal.Two commemorations have been celebrated. The first, in honourof the 175th anniversary of the birth of the Abb6 Haiiy, has beenacwmpanied by the issue of a special number of the Americanil_lin,eralogist containing many interesting portraits, facsimile letters,and scme eight essays by American mineralogists.The centenaryof the foundation of the American Journal of Science has also beenwoithily sigiialised by the appearance of a special number: contain-ing historical accounts of the development of world science ingeneral and of American science in particular. Apparently the firstAmerican Xineralogical Society was founded in 1799.The gradual transformation undergone by the science of miner-alogy during the last fifty years has been eloquently described inrecent accounts by Sir H, A. Miers 6 and G.T. Prior.6 The progressof crystallography is not less amazing. Crystal strudure is becom-ing incre and more a happy hunting ground for all kinds of physi-cists; and i t seems not impossible that the complexities of thegaseous and fluid conditions (which appear t o be relatively simple,since they are merely studied in the aggregate) will only be un-4 “ A Century of Science in America,” Amer. J . Sci., 1918, [iv], 46, 1.T., 1918, 113, 363. Geol. Nag., 1919, [vi], 6, 10CRYSTALLOGRAPHY. 199ravelled when crystal structure shall have been profoundlyelucidated.X-Ray Methods of h’xploring Crystal Structure. The Debye-Scherrer-Hull Method of X-Ray Exploration.This ingenious method of studying crystal structure, when thematerial is an irregular aggregate of tiny crystals, not necessarilyendowed with plane faces, was independently and almost simultane-ously devised by Debye and Scherrer 7 and Hull.* Although formallythe method is an extension of the original Laue photographicmethod, all interpretations have, of course, been really renderedfeasible by the spectrometric researches of W.H. and IV. L. Bragg.The following account was compiled in the first instance from Hull’sFIG. l a . FIU. lb.Rpaper became it was more accessible. It will be seen later thatDebye-Schemer and Hull only differ in subsidiary details.Suppose (Fig. l a ) a monochromatic beam of X-rays, A B (whichhas already passed a series of fine slits), be allowed to impingeon thecube face of a crystal of potassium chloride, a t the correct glancingangle, $, for the first order “ reflection,” and the rays be receivedon a narrow photographic film, YEP’, bent to the form of a semi-circle with centre B , then the film on development will show a muchover-exposed line, E, due to the undeviated beam, and a line k’, dueto cumulative reflection, the distance of which from E is determinedby the arc 28,.If now the glancing angle be increased to a newvalue, 8, (the appropriate angle for the second order reflection), a7 P. Debye and I?. Scherrer, Physikal. Zeitsch., 1916, 17, 277 ; 1917, 18,291 ; A., 1917, ii, 437.A. W. Hull, Physical Bev., 1917, [ii], 10, GG1200 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.new line, G, will make its appearance, the arc BG' being measuredby 28,; and so on for a third or still higher order.I n all cases the glancing angles of intense reflection are related tothe distance, c&,, between successive structural planes, by the equa-tions, h=2cl.sin 8, 2h=2d. sin 8,, 3h=2d. sin 8,, and so on.9If, again, dodecahedra1 and octahedral plates be subject to experi-ments, new lines will appear, in positions involving the new gratingdistances dl10 and d,,,.Now consider what will happen if some very finely powderedpotassium chloride be placed at B (instead of a crystal plate) andan exposure taken without troubling about any particular glancingangle (Fig. l b ) . There will simultaneously be a considerable numberof minute crystals having the same orientation as the first crystaiconsidered above, but these will oiily constitute the members of alarger group, making the same angle with the incident beam, butlying in all azimuths.The I ' reflected " beams from crystals of thisgroup will form a hollow cone of total angle 48,, and will interceptthe film in symmetrical positions P and 3''. There will be manyFJG. 2.G F E F'333 330 222 300 220 200 I l l 110 100 100other crystals having the second kind of orientation, which will give'rise to the hollow cone GRG', and so on. (If a plane, film, R, wereused concentric circular impressions would result, but a plane filmof manageable diniensions would only register cones up to 48, where8=22io'). After the semi-circular film has been unbent anddeveloped, the lines on the portion El' for the first three orderreflections will be in the positions given in Fig.2, in which theindices (222) signify a second-order reflection from (lll), and so on.It will be realised that the linear distance of any line from E is asini-ple function of (1) the radius of the bent film, (2) the wave-length of the X-rays used, (3) the order of the reflection, and (4) thefundamental grating distance, d , of the1 atomic strata, responsiblefor that line.I n the actual case of potassium chloride there would, of course,be more than nine lines. 'The number of lines is dependent on thewave-length of the monochromatic X-rays employed, for, althoughthe number of possible structaral planes is infinite, only those planes0 The Reporter regrets the slip involved in a previous Report (,47an.Report, 1914, p.240, lilies 22-27)CRYSTALLOGRAPHY. 201can reflect any energy the distances apart of which are greater thanA / Z . Thus, there is a limit to the number of lines, depending onboth structure and wave-length employed. The following tablerefers to the diamond.No. of linesX-Rays used. Wave-length. theoretically possible.Tungsten doublet ............... 0-212 x 10-8 More than 100.Rhodium doublet ............... 0.617 30.Iron doublet ..................... 1-93 Only 3, namely, fromMolybdenum (K,-doublet) ... 0-712 27.{llli, j l l O l , 1311;.From the method of experiment’ation it will, perhaps, be obviousthat a form { 311) of the diamond, consisting of twelve structuralplanes, will only give one line.The existence of the twelve planesmerely enhances by twelve the chance that a crystal shall have thecorrect orientation ; accordingly, the intensity of the line is propor-tionately increased. This property constitubes an advantage in thestudy of planes of the general indices { h k l } , for the co-operation ofthe twentg-four planes (of a cubic crystal), each of which will havea subordinate reflectivity, may lead, so to speak, to a combinedcreditable effort.The principles and routine of the interpretation are clearlyexpounded by Hull and applied to the analysis of ten crystal aggre-gates, one of which, the diamond, was purposely selected as a check.In theory, nothing need be known about the system or “crystalelements,” but, in practice, if these are known the burden ofanalysis is greatly lightened.The crystal powder (0.005 gram, or, if necessity compels, one-tenth of that) is best contained in a thin-walled tube of 1 mm.dia-meter. The material of the tube. must naturally be amorphous(glass, celluloid, or collodion). Perfeot irregularity of the crystalgrains is desirable for uniform results, and can be ensured byrotating the tube during the exposure.In order t o render t.he X-rays more monochromatic, Hull alwayspasses them through a suitable screen, which absorbs stray wave-lengths. If molybdenum rays are used, the screen should bezirconium or a compound like zircon.10I n a later paper the author11 shows that his method can beemployed successfully as a method of chemical analysis (that is,identification of substances the characteristic linw of which arealready known).For example, a specimen of ‘‘ chemically pure ”sodium fluoride was found to exhibit the characteristic lines, both ofsodium fluoride and sodium hydrogen fluoride, NaHF2. It is alsolo A. W. Hull and (Miss) ISI. Rice, ibid., 1916, [ii], 8, 326.l1 A. W. Hull, J . Amer. Chem. SOC., 1919,41, 1168; A., ii, 470.H202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.evident that a mixture of sodium fluoride and potassium chloridecan be readily distinguished from a mixture of the same bulk com-position of sodium chloride and potassium fluoride, for the molecularvolumes (and therefore grating distances) of the four compounds aredifferent.Debye and Scherrer press the powder into the form of a rod, and,if necessary, give it a coating of collodion to prevent disintegrationduring the radiation.The photographic film they arrange in theform of a cylinder, with axis perpendicular to the incident beam.The various cones intersect the film in curves represented schemati-cally in Figs. 3 and 4, the1 last-mentioned figure representing halfthe unbent film. Of course, the linear distances only need bemeasured along the symmetry trace X Y .FIG. 3. FIG. 4.X YThe method is absolutely trustworthy up to the point a t whichThis point will be illustrated later under the interpretation begins.‘‘ graphite ” (p. 203).The reconstructions or models offered by the various workers sincethe appearance of the last Report will now be considered.The listwill be restricted to models which are relatively final, as space doesnot admit of any discussion of the less satisfactory cases. Gratingdistances are in al1,cases given in Angstrom units, and must accord-ingly be considered as multiplied by 1 0 - 8 om.Cubic System.‘‘ Cubic ” lattic2 ......... None so far dkcovered.Centred lattice ............ Tungsten (Debye*) ; a=3.18 (length of cubeletedge).a = 2-86a = 4-30.a==3.50 (author not entirelyIron (Hull) ;Sodium (Hull) ;Lithium (Hull) ;satisfied).* P. Debye, Physikal. Zcitsch., 1917, 18, 483 ; A., 1917, ii, 571CRYSTALLOGRAPHY. 203C‘*t~bic: System (continued).Centred lattice . ........... Nickel (Hull) ; a=2.76 Hull believes to bedimorphous, but heFace-centred lattice ...Nickel (Hull) ;Diamond “ lattice ” ...a= 3-52 (is not sure).Aluminium (Hull) ; a=4.05.,, (Schemer*) ; n=4.07.Diamond (Hull) ; absolute agreement with W. H.Silicon (Debye and Scherrert) ; a= 5.46.Grey tin (theu = 6.46.Lithium fluoride (Debye and Scherrers) ; a=,4-14.Lithium fluoride, sodium fluoride, potassiumfluoride, magnesia (Hull 11) ; distances not stated.and W. L. Bragg.9 , (Hull) j‘ a= 5.43.tin-pest ’’ : Bijl and Kolkmeijer;)Rock-salt structure .. .* P. Schemer, Physikal. Zeitsch., 1918, 19, 23; A., 1918, ii, 113.t P. Debye and P. Schemer, Physikal. Zeitsch., 1916, 17, 277.Z A. J. Bijl and N. H. Kolkmeijer, Proc. K . Akad. Wetensch. Amsterdam,8 P. Debye and P. Schemer, PhysikaE.Zeitsch., 1918, 19, 474 ; A., ii, 20.II A. W. Hull, J. ,4iner. Chem. SOC., 1919, 41, 1168; A., ii, 470.1919, 21, 501 ; A., ii, 161.Hexagonal System.Magnesium.-This interesting structure, unravelled by Hull, canbe most simply described as Barlow’s close-packed hexagonal systemof spheres, slightly deformed. More precisely stated, there are twotriangular, prismatic lattices 12 (a = 3.22, c = 5.23) so interposed thatone centres the other.Graphit e.-This substance has been examined by Debye andScherrer 13 and by Hull,14 who suggest slightly different models.The former workers interpret the structure as an interpenetration oftwo facecentred rhombohedra (of edge 4-48), so that the vertex ofone lattice lies one-third the full vertical distance (10.23) below theother.The vertical distances bebween successive horizontal layersof atoms is accordingly 3.41 (agreeing very well with W. H. Bragg’spreliminary determination, 3‘42) ; the crystallographic constant ofthe f ace-centred rhombohedra1 lattice, a, is 68O26’.Hull’s analysis takes the form of “ a n hexagonal structure, com-posed of four simple lattices of triangular prisms, each of side2.47 and height 6.80, the atoms of the third lattice being directlyabove those of the first a t a distance of one-half the height of thel2 The term “ triangular lattice ” is a useful- variant of “ 120°-prismlattice,” for it obviates circumlocution in describing certain cases of inter-penetration.l3 P. Debye and P. Schemer, Physikal. Zeitsch., 1917,18, 291 ; A ., 1917,ii, 437.lP A. W. Hull. Phaysicd Rev., 1917, [ii], 10, 661.H* 204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.prism, those of the second and fourth lattices being above thecentres of alternate triangles of the first, a t distances 1 / 14 and 8/ 14respectively of the height of the prism.”A comparison of the above two models may well be given here,because the differences are so small as to make it improbable thatthe real solution will be agreed on before the lapse of several years.Debye and Scherrer used a copper anti-cathode and Hull one ofmolybdenum. This made i t necessary to calculate all Debye andScherrer’s grating distances in order t o eliminate inessentials duet o different wave-lengths. The experimental results were thenfocnd to be in substantial agreement, both with regard to gratingdistances and intensities.Hull’s reflections go far beyond the rangeof Debye and Scherrer’s owing to the shorter wavelength of themolybdenum rays, and incidentally include a reflection, beyondDebye and Scherrer’s observed lines, which will fit in with theirunrepresented (O$a).l5 On the other hand, Hull is not quite satis-fied with his model because certain reflections are missing, theabsence of which he refers to some special dist.ribution or other ofthe electrons‘within the atom. The writer finds that all thesereflections are represented in Debye and Scherrer’s list of lines,with the possible exception of one line, which is attributed by themto the P-radiation of copper.If this line is in reality an a-line (theallocation of “ a ” or “ P ” appears to be sometimes a matter ofopinion rather than exactness) all Hull’s missing lines are accountedfor, and presumably there need be no appeal to a special electronicdistribution.For simplicity of comparison Hull’s refined estimates of level,1/14 and 8/14, must be arbitrarily altered t o 0/14 and 7/14 (with-out, of course, implying that his model is in any way incorrect).I n each model atoms are then arranged in horizontal planes accord-ing to a bee-cell pattern. Moreover, the edge of the hexagon isthe same within the errors of experiment, say, 1.45. The, bee-cellpattern will therefore be adopted as a medium of expression. Thedistancw between successive layers is the same (3.40-3.42).Theonly difference, is that Hull’s third layer of bee-cells is verticallyabove the first layer, whilst in Debye and Scherrer’s model everyfourth layer is above the first. Plans of the two structures aregiven in Figs. 5 and 6, in which the various layers are distinguishedby different kinds of lines and by the adoption of point-circles andcircles of different radii for the atoms. Only two. and three layersneed be shown respectively in the two figures.l5 Debye and Scherrer’s stated reflection (022) is really a first order reflectionIts absence would have seriously undermined their model-a point ( O i l ) .which they appear to have overlooked.CRYSTALLOGRAPHY. 205It is of interest t o note that Debye and Scherrer regard thediamond as the prototype of aliphatic compounds (owing t o thetetrahedral environment of each atom), and graphite as the proto-type of aromatic compounds, since it can be held to illustrate threeprincipal valencies in a horizontal plane and an unique valency,directed up or down, serving to interlock the various strata(compare, however, p.208).Charcoal.--“ Amorphous ” charcoal from most varied sourcesyields three lines, all of which are coincident with specific graphitelines. Debye and Scherrer have accordingly concluded that charcoalFIG. 5 . FIG. 6.consists of polyatomic (‘ molecules ” (containing 20 or 50 at,oms),these ‘‘ molecules ” being tiny fragments of the graphite structure.Tetragonal System.C‘halcopyrit e , CuFeS,.-This interesting mineral has been investi-gated by the Bragg method by C.L. Burdick and J. H. Ellis,l6 whooffer the model shown in Fig. 7, in which the copper and ironatoms taken collectively form what may be loosely described as aface-centred cubic lattice (the axial ratio c :a= 0.985). The sulphuratoms are found to occupy the centres of half the smaller “cubes,’7selected tetrahedrally. The calculated intensities of the variousreflections fit in very well with the observed valueg. A cursoryglance at the figure will show that the structure is that of zincblende, in which half the zinc atoms are replaced by copper atomsand half by iron atoms. Yet in spite of this great similarity zincblende has a perfect dodecahedra1 cleavage, whilst chalcopyrite hasnone ; moreover, an octahedral cleavage is characteristic of theJ .Amer. Chem. Soc., 1917, 39, 2518; A., 1918, ii, 46206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.related diamond structure. The property of cleavage is evidentlyas mysterious as the development of plane faces on a crystal. TheReporter finds the structure to be an example of the Fedorov pointsystem 33s (Xchonflies, VL; Barlow, 59&; Hilton, Did).White Tin.-As in the case of the grey modification, the exam-ination 17 was carried out by means of the, Debye-Scherrer method,and led to the result that a structural tetragonal cell (with dimen-sions u=5*84 and c=2.37) has its vertical sides centred; that is,there are three interpenetrating tetragonal lattices.Now the struoture demands a value for the ratio c :u=0‘406, which incidentallyinvolves that the only common form, p { 111 1, should have theindices { 403j. This perversion of form development is unexampled.FIG. ‘1.If the accuracy of the analysis is unquestionable, it signifies thatlittle is definitely known about the correlation of form and struc-ture.Rhonabohedral System.Curb orwzdum, CSi .-A thorough examination 18 of t,his substanceresults in the following interpretation. The crystal is pseudo-cubicfor the angle a=89O56/. The silicon and carbon atoms each furnisha ‘‘ face-centred rhombohedra1 lattice,” l9 the two lattices interpene-l7 A. J. Bijl and N. H. Kolkmeijer, Proc. K. Akad. Wetensch. Amsterdam,1919, 21, 494 ; A., ii, 161.C.L. Burdick and E. A. Owen, J . Amer. Chem. SOC., 1918, cu), 1749;A . , ii, 62.l9 It is, perhaps. worth while pointing out that tha term “face-centredrhombohedra1 lattice ” used by X-ray workers is one of convenience, anddoes not imply the existence of more than one Bravais lattice in the rhomboCRY STALLOGRAPRY. 207trating with a comnion vertical axis and in such a way that a hori-zontal layer of carbon atoms is displaced vertically through 0*36d,where d signifies the distance between successive horizontal layersof carbon or of silicon atoms.dcZde?zda.-The model offered by Vegard and Schjelderup 20 forthe alum group has been refuted by Niggli,21 who in turn offers amodel, which cannot be considered for reasons of time and space.Several theoretical papers require a brief notice. The interpretationof the results of the Debye-Scherrer-Hull method is also discussedmathematically by C.Ruiige22 and by A. Johnsen and 0. T0eplitz.~3General explanatory papers and books on the relationship of X-raywork to the theory of crystal structure are becoming more nunier-ous. The excellence of Kreutz’s24 book is only marred by t,he factthat he practically ignores the Fedorov-Schonflies point systems.Voigt25 in an interesting paper is incline,d to weigh t’he relativemerits of Sohncke and Fedorov-Schonflies. It does not seem to begenerally recognised that there is no question of a comparison ofthe Sohncke theory or of a somewhat halting, because ad-hoc-extended, later Sohncke theory with the Fedorov-Schtinflie theoryhedral system.Any rhombohedral lattice can be described either as rhombo-hedral or as a centred-rhombohedra1 or as a face-centred rhombohedrallattice, each variant implying a specific axial ratio or fundamental angularconstant a. Any particular choice is one of taste, in just the same way asis the allocation of the indices (110; or (100; or {ill) to, say, the cleavage,rhombohedron of calcite. It is interesting to note that, if the allocation ofindices were consequential instead of conventional, the X-ray exploration ofcalcite demands the indices fl00) for the steep rhombohedron f f l l l } . Thelatter transformation was indeed suggested long ago by Goldschmidt, pro -ceeding from what is really a principle of simplicity of indices which wassubsequently developed by Fedorov and then abandoned because it wm notsufficiently exact for the purposes of crystallo-chemical analysis.Evenmore radical transformations of indices have been advocated by Fedorov.It seems t o the writer, however, that transformations are never expedientin conventional descriptions of crystal morphology, for they are liable to createconfusion. On the other hand, in the practice of crystallo-chemical analysisall questions of taste or opinion have naturally to be rigorously subordinatedto uniform principles, covering both the deduction of the space-la$tice andthe erection and orientation of that lattice. The tendency of Fedorov’sand Go1dschmidt)’s highly original work is to create barriers between the“ old ” and the “ new ” crystallography.These barriers are really built upof inessentials ; their eventual removal will presumably lead to a fusion ofthe more reasonable elements of the conservative and progressive sectionsof crystallographers.2o L. Vegard and H. Schjelderup, Ann. Physik, 1917, [ii], 54, 146; A . ,1918, ii, 156.21 P. Niggli, Physikal. Zeitsch., 1918, 19, 225 ; A., 1918, ii, 315.2 2 Ibid., 1917, 18, 509.24 S. Kreutz, “ Element8 der Theorie der Krystallstruktur ” (1915).25 W. Voigt, Physikal. Zeitsch., 1918, 19, 237.23 Ibid., 1918, 19, 47208 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.-however geiielrally i t is concedeid in other branches of geometrythat t'he whole necessarily includes the part.Debye and Scherrer o n Atomic Structure in a Crystal.A recent paper by Debye and Scherrer26 may, perhaps, beregarded as the present' high-water mark of X-ray investigation.The authors advance certain theoretical considerations which serveto harmonise Braggs' principle (that the arnplihde of reflectedX-rays is proportional to the atomic weight) and Barkla's con-clusion that the atomic weight is proportional to the intensity(square of the amplitude1),27 and they conclude that the inteasityof radiation depends on the number (Moseley number) and posi-FIG.8. FIG. 9.tion of the electrons in the atom. The authors believe that theirmethod of X-ray expelrimentation is delicate enough to examinetwo questions of t5he greatest import.The first of these questions rdatw to the mechanism of theattachment between atoms in a crystallised element.For example,in the diamond structure each carbon atom is environed tetra-hedrally by four carbon atoms. Are the four atoms held bywhat may be termed chemical valencies? Now the chemicalvalency between the) two atoms of a hydrogen molecule is a t p r esent int'erpreted mechanically as due to a midway dielectronic ringwith a plane of rotation perpendicular to the valency bond. Ifthis were also true for thel diamond structure, the crystal wouldhave the diagrammat'ic structure represented by Fig. 9, in whichonly two out of the six Moseley electrons of each carbon remain26 P. Debye and P. Scherrer, Physikal. Zeitsch., 1918, 19, 474 ; A., ii, 20.27 W. H. and W. L.Bragg, " X-Rays and Crystal Structure," p. 49CRYSTALLOGRAPHY. 209in the atom, and each of the other four, joined by one more fromone of the four nearest atoms, rotates round a point which islocated half-way between a pair of atomic centres. The differencesbetween the new and the original Bragg structure (Fig. 8) aresufficiently great as to allow of a definite decision one way or theother, by means of a careful analysis of the inte'nsities of the curvesin a Debye-Scherrer X-radiogram. Amongst other things, thereshould be a strong second-order relflection from the octahedralplanes. The result decisively negatives the subsistence of chemicalvalencies due to electronic rings and substantiates anew the Braggstructure. Moreover, other examples (of elements ? not specified)have been investigated, and the authors have not been able to finda single case in which electronic rings serve as bonds in a crystal.The second question relates to the possibility of ionisation incryst?als of electrolytes.Since the reflecting power of an atomdepends on the number of electrons, the power will be correspond-ingly modified by the loss or gain of an electron due t o ionisation.As a result of a careful analysis of the X-radiogram of lithiumfluoride (co-structural with the sodium chloride group), Debye andScherrer conclude that the lithium has lost and the fluorine gaineda negative electron. Itis again assumed that the diffracting power of an atom is elqua1 t othe number of negative electrons as given by the Moseley number,namely, Li=3, F = 9 .I n all the structural planes of lithiumfluoride having three odd indices, for example, (1111, {113},{ 133}, planes are alternately ,wholly lithium and wholly fluorine ;the effective reflecting values will either be 2 and 10 or 3 and 9,accordingly as the structure is ionised or not. The authorsconclude that the crystal is ionised.28The method of reasoning is as follows.General Conclusions : A Suggestion.It has now become fairly evident that the X-ray method ofexploring crystal structure is really a (I sub-chemical " method.2s The above conclusion was not easily deduced, for sodium fluoride,if ionised, should present no first order reflections from planes havingthree odd ,indices. Such planes did, in fact, give weak reflections.The way out of this difficulty involved theoretical considerations, in-cluding estimates of the disturbances due to temperature (subsequentlyapplied to lithium fluoride), the objective value of which the presentwriter feeIs he is not competent t o estimate.In view of the fundamentalimportance of the subject, most crystallographers would feel happier if theresults of any future comparative investigation of the whole co-structuralgroup of alkali haloids mutually confirmed each other, for there would thenbe a reasonable certainty that the theoretical considerations are congruentwith the workings of nature210 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Whilst it probes the structure more profoundly than a purelychemical method ever sets out to do, it does not a t the presentmoment give any information on chemical properties or structure.For example, although the similarity of structure of carbon(diamond), silicon, and tin can be held t o have chemical signifi-cance, and although we are possibly on the eve of absolutely trustpworthy information concerning the existence or no of " ionisation "in crystals, there is, so far, no real information from X-ray sourceson the mechanism of such chemical unions as are implied by theformula CH,, or the formula (SO,) of the sulphate radicle, or bythe commas characteristic of the formulz MgS04,7H,0,and 2KF,SiF,, or the significance of a happier variant of thelatter, K,[SiF,]. It would appear that chemical information onall these points can only accrue by the X-ray method in so faras the unions are1 brought about by the1 transfer of one or moreX-ray diffracting electrons.During recent years there has been a tendency to jump to theconclusion that molecules disappear in a crystal and become partsof an indefinitely extended crystal molecule.X-Ray physicistshave never claimed that their work decides the question one wayor the other, although the close approach of the three oxygen atomsin the calcite structure could be interpreted, perhaps, as a signthat the (CO,) group exists as an entity. A t the present momentsomet-hing more than mental inertia compels the view that mole-cules or ionic groups persist in a crystal; i t will be time to revisethe view when, say, i t is the usual thing for a crystal of an ortho-ccmpound to give a mixture of ortho- and para-derivatives on melt-ing, or vice versa.A celrtain amount of pooling of affinity mayexist in a cryst'al (and so lead t o a very shadowy, indefinitely ex-tended " molecule "), but t o a degree that is a t present quitel vagueand scarcely susceptible of discussion.So far as crystallography is concerned, the result of the X-raywork is the proof that the abstract theory of crystal structure(built up by the efforts of Hauy, Frankenheim, Bravais, Sohncke,Fedorov, and Schonflies) faithfully embodies a concrete reality.The present interpretation is an atomic interpretation, becausemolecules are, so to speak, outside the terms of reference of theX-ray inquiry.Work on the infra-red29 is susceptible of a molecular interpretation, but possibly other methods will have to be29 C. Schaefer and M. Schubert, Ann. Physilc, 1916, [iv], 50, 283, 339 ;1918, [iv], 55, 397, 577 ; 1919, [iv], 59, 583 ; A., 1916, ii, 505 ; 1918, ii, 282,315 ; K. Rrieger, ihid., 1918, [iv], 57, 287 ; A., ii, 37.&SO4,MgSO4,6H20CRYSTALLOGRAPHY. 211found before the molecular aspect of crystal structure becomes fullyrevealed.The results already obtained are of such superlative importanceas to make it desirable thatl the X-ray work shall continue alongcrystallographic lines and not altogether take other directions.There are signs, however, that future developments may not beso rapid. It would seem that the simpler cases are being exhaustedand that great difficulties stand in the way of future progress.Many of the cases which have been examined defy any trustworthyinterpretation.Although further result-s can be expected from a more refinedinvestigation of the simpler cases already elucidated, investigationson slightly less simple cases is the obvious next step. How arethese cases t o be selected? Past results have supplied an answer,but only on the negative side.Degree of complication evidentlydepends on two main factors, complexity of chemical compositionand lack of crystal symmetry. The two factors are mysteriouslyinterwoven, and may only be separated in a tentative manner forillustrative purposes. The orthorhombic sulphur and thehexagonal ( 1 ) graphite are less simple than any cubic element, butthey are also less simple than the rhombohedra1 calcite.Thetetragonal cassiterite (complicated enough) is simpler than thecubic garnet. The orthorhombic potassium sulphate, K,SO,, ismore complicated than the cubic spinel, Al,MgO,. When the twofactors are regarded singly, it appears likely that complexityincreases in a kind of geometrical progression with the number ofkinds of atoms and with degradation of symmetry. No successfulinterpretation has yet been offered for a substance containing fourkinds of atoms (with the possible exception of Niggli’s alum model)or for an orthorhombic, monoclinic, or anorthic crystal.I n the past, the proper choice of material for investigation wasperhaps fairly obvious ; elements and simple compounds crystal-lising in the cubic system invited inquiry.More recently, theselections have not been so fortunate. The selections have,perhaps, been guided by physical rather than chemical instincts.The present writer believes that a proper regard to both chemistryand physics is more likely to lead to happy selections, and that thereal finger-post is symmetry.Although inany exceptions are known, it is, nevertheless, astatistical truth that everything strives towards symmetry in sofar as the environment will allow. Chemical molecules take upsymmetrical configurations-otherwise 99 per cent. would betheoretically resolvable into enantiomorphous configurations212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Again, the arrangement in a crystal tends towards symmetry.Most elements crystallisel in the cubic, hexagonal, tetragonal, andrhombohedral systems.Binary molecules, like sodium chloride,possessing a rotational axis of symmetry, group themselves in highlysymmetrical ways (the grouping possibly being facilitated byionisation). Organic chemical molecules, which configurationallyrarely possess more than a plane or centre of symmetry, generallyarrange themselves during crystallisation according t o a highersymmetry (45 per cent. in each of the orthorhombic and monoclinicsystems). Unfortunately, this higher symmetry is frequentlyaccompanied by grave complications, inte)rpene;tration of molecularor ionic space lattices giving rise to more general point systems, theelucidation of which becomes accordingly difficult. There is, how-ever, a fairly well-represented class of Substances in which the mostprobable stereochemical configuration has the same symmetry asthe crysbal form.Such structures are less likely to be compli-cated ; the number of structural parameters should be relativelysmall. These are the substances which appear t o be worthy of theimmediate attention of X-ray workers. A few typical exampleswill serve as illustrations.I n the province1 of organic chemistry, molecules of carbon tetra-bromide and tetraiodide, silicon tetraiodide, and hexamethylene-tetramine, N,(CH,),, have the symmetry of a regular tetrahedron,and the substances crystallise in the cubic system (carbon tetra-bromide above1 4 7 O ) .The e1ucidat”ion should be easier than thatof garnet. I n inorganic chemistry, there are many compounds,like potassium platinochloride and periodatel, which are “ tetra-gonal ” configurationally and in crystallisation. I n the rhombo-hedral system, in addition to calcite, theire are numerous groups ofcompounds, of which the following formulae illustrate examples :Mg,SiF,,6H20, MgPtI,,SH,O, MgPtBr,,12H20. I n all these cases,the natural configurations for the separated parts, say,[Mg,GH,O]++ and [SiF,] - -, are rhombohedral, and the structureswill presumably involve two or four parameters more than in thecase of calcite. However complicated the formuh may appear, thestructures can scarcely be as difficult as in a case like potassiumsulphatel, where a tetragonal molecule1 or SO, group is degraded t ofit in with an orthorhombic type1 of symmetry.With regard to the question whether the1 exploration of, say,carbon tetrabromide should reveal the quadrivalent nature ofcarbon, it seems certain that an appeal to a transfer of electronswill not help matters, for relative intensities can scarcely sub-stantiate an assumption (transfer of electrons) concurrently withthe value of the bromine parameterCRYSTALLOGRAPHY.213Tammarm's ll'orlc on Biffusioit and Reaction Limits : Chemicaland Galvanic.It may be stated a t once that the work capitalises the interestthat has always been attached to the property of diffusion in thesolid state,30 and has, no doubt, considerable metallurgical signifi-cance.Tammann31 shows that cast, untempered alloys, or, whatamounts t'o the same thing, tempered alloys which have been sub-sequently subjected tto harsh treatment (rolling, drawing into wire,hammering, and so forth), tend t o behave incoherently towardschemical reagents, whilst tempered alloys take on themselves someof the properties of a compound. He presents a mass of experi-mental data which a t least goes a long way towards proving thatmixed crystals (not compounds in the formal sense) in certainsimple, definite proportions resist chemical action in the samedegree as is exhibited by the more dour constituent. Thisorganised resistmame is ref erred to an intimate atomic equilibrium,sejt up as a result of diffusion, whereby the structural space latticeloses the properties of a conglomerate and acquires that perfectionof design which is characteristic of the structure of an uncon-taminated metal or pure chemical compound.So much by wayof introduction; we may now consider a few details, almost whollyrestricted to gold alloys.Chemical Behaviour of Well-t empered ,4 Iloys.-At bokh ordinaryand at slight*ly elevated €emperatures, well-tempered copper-goldand silver-gold alloys remain uncorroded in general and do notbring about any deposition of metal from solution when digestedfor a prolonged period with solutions of palladous chloride,platinous chloridei, yellow ammonium sulphide, sodium disulphide,sulphur dissolved in carbon disulphide, sodium diselenide, picricacid, or alkaline solutions of sodium tartrate, provided the alloycontains 25 molecular per cent..or more of gold; i f , however, thegold content sinks t o 24 per cent., chemical reaction takes place.Again, with the silver-gold series of w ell-annealed mixed crystals,the limit of reaction for solutions of gold chloride, chromic, per-manganic, and nitric acids lies sharp a t the 50 molecular per cent.composition. Further, a t t.he, ordinary temperature, moist air coii-taining hydrogen sulphide has no action on copper-gold alloys con-taining a t least 25 molecular per cent. gold, but a t t,emperatureshigher than looo, alloys of all compositions are gradually attacked,30 Compare " Diffusion in Solfds," by C.H. Desch, Brit. Assoc. Reports,1912, 348.31 G. Tammann, Zeitsch. anorg. Ghem., 1919, 107, 1-239 ; Nachr. Ges. WZ'SA.Gdttingen, 1916-1919 ; A., 1917-1919, ii214 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with the formation of oxide or sulphide of copper. This reactivityTammann attributes to the enhanced rate of diffusion of copperand gold atoms, so that action is no longer restricted to the finestpossible surface layer. Mercurous salts also attack the wholecopper-gold series (pure gold excepted), even a t the ordinarytemperature; there is, however, a reaction limit in the matter ofa precipitation of mercury from mercuric chloride a t the composi-tion 25 molecular per cent. gold. There is also a limit in thereaction of solutions of silver salts; in this case, itn is not so sharplydefined, lying between the limits 8-15 molecular per cent.gold.Presumably, by analogy, Tammann considers the upper limit aslying at 1 / 8 gold (12.5 molecular per cent.).With some reagents there is not merely an absolute resistancelimit-there is also a relative resistance limit. Thus, boiling nitricacid removes the whole of the copper or silver from a’gold alloyprovided the gold content is less than 318 mol. ; if the com-position lies between 3/8 and 4/8 gold, only part of the less noblemetal can be extracted; if the composition lies between 418 and 8/8gold, the specimen, as stated above for many other reagents, iswholly unattacked.Chemical Beha8viowr of Unt empered A 1Zoys.-Several series ofcomparative experiments were made on the effect of temperingcopper-gold alloys (having compositions close to the 418 limit) onthe sharpness of the limit of reaction.The reaction selected wasthe deposition of finely divided gold from a solution of aurouschloride. The reactants were sealed up in tubes and inspectedfrom time to time, and the strips of alloy were subsequentlytempered and digested afresh with solution. The results seem veryconvincing. Untempered strips ranging up to a 51 molecular percent. gold content became stained in patches, owing to parts of thespecimen having a less percentage composition than 50. Iftempered a t 900° for forty hours, an alloy containing 50.5 mole-cular per cent. of gold remains bright, whereas equally temperedalloys containing 49.5 per cent.or less become brown. It must,accordingly, be concluded that the reaction limit for the homo-geneous mixed crystal lies a t 50 molecular per cent.The deleterious effect of cold-working a previously tempered“soft” alloy on the sharpness of the reaction limit is illustratedby a series of experiments on the action of sodium sulphide, onsilver-gold alloys. Well-tempered plates (0.5 mm. thick? exhibita reaction limit within the narrow range 24.5-25.5 molecular percent. gold. When the same plates had been rolled and beaten outto an order of thickness represented by 0.01 mm., discolorationtook place even with a gold content of 55 molecular per centCRY STALLOGRAPHS. 215Galvanic PoterttiuZ.-The application of thermodynamic theoryto a study of the dependence of polarisation potential on the com-position of an alloy presupposes that the several kinds of met’allicatoms can inter-diffuse with great rapidity.This condition is,however, not fulfilled at ordinary temperatura, so that mixedcrystals may be expected to betray a de’finite resistance limit. Thisexpectation was realised, for example, in the copper-gold andsilver-gold series of alloys. The polarisation potential for “soft ”t’empered gold-silver alloys in an alloy I AgNO, solution I Ag elementhas the constant value 0.808 volt for all mixed crystals varyingfrom 100 to 50 molecular per cent. gold, whilst the much lowervalue 0.71 volt is suddenly found €or mixed crystals cont’aining49 per cent.gold. On the other hand, “hard ” untempered alloys(non-homogeneous), whilst showing something of a break a t the50 per cent,. composition, do not exhibit the constant value 0.808volt for gold-rich series, but values fluctuating between 0.703 and0.739. A series of investigations was made at higher temperatures.In the case of the element-AgAu, 1 AgNO, I glass I NaN03,KN03,AuC13 1 Au+,i t was found that the potential varies greatly with the tempera-ture and changes with the time. The galvanometer readings firstbecame independent of the time at 320°, and at this temperaturethe values showed no break at 50 per cent. composition, but variedcontinuously for the whole series of Au-Ag alloys. This funda-mental difference of behaviour a t low and high temperatures is inharmony with the differences already mentioned f o r “ chemical ”reactivities; they indicate that, at temperatures a t which an activeprocess of diffusion is out of the question, the chemical propertiesof metallic mixed crystals change discontinuously a t certain definiteconcentrations.Tammann emphasises the point that these changescannot be referred to1 the formation of chemical compounds in theformal sense, for the substances in question are miscible in all pro-portions and chemically similar. It may be added that theocclusion of hydrogen by mixed crystals of palladium and platinumreveals corresponding discontinuities.32Behuviour of Mixticres of Sodium Chloride and Silver Clzloricle.-Although such mixed cryst-als cannot be obtained from aqueoussolution, for obvious reasons, they are readily obtainable in anyproportion from mixed fusions.33 The process of leaching thesemixed crystals has been studied by Tammann and Schmidt.34 The32 G.Tammann, Nachr. Ges. Wiss. Grittingen, 1918, 72 ; A., ii, 293.33 C. Sandonnini, A t t i R. Accad. Lincei, 1911, [v], 20, i, 758; A., 1911, ii, 800.3 4 G . Tammann and K. W. Schmidt, Nachr. Ces. IYiss. Gottingen, 1918,296 ; A., ii, 396216 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.results depend greatly on whether the mixed crystals have or hawnot been tempered (that is, rendered homogeneous by holding a ta temperature well below the melting point for a considerable time).Well-tempered crystals (powdered to a size less than 0.05 mm.)refuse t o yield any so’dium chloride provided the composition isa t least 6/8AgC1, whilst crystals ranging between 5/8AgCl andpure NaCl give up the whole of the sodium chloridel.I n theinterval, 6 / 8-5 i 8AgC1 part of the sodium chloride is extractable.Synopsis of Results.-The following table will indicate the com-prehensive nature of Tammann’s investigations and their generalresults. I n every case the fraction refers to the second memberof the metallic pair of components :Components.Ag-Au ........................CU-AU ...........................Fe-V .............................Ag-Mn ........................Ag-Mg ........................*Zn-Ag ...........................*Zn-Au ...........................Pd-Au ........................Pd-Ag ...........................Chemical and galvanicreaction limits.- 218 418- 218 418118218 -1/8 -218 -- 218 418418418418- ----- -- -* The alloys containing zinc appear t,o be complicated owing to the existenceof “ intermetallic compounds. ”Tammann’s Theoretical Interpretation.-The interpretation ofthe above interesting observations is naturally of a geometricalorder. Only the sketchiest description can be given here. Thereare three space lattices in the cubic system: the cube (Tammann’s“ &point lattice ”), the centred cube ((( 9-point lattice ”), and thefacecentred cube ( ( r 14-point lattice ”). F o r each of these latticesthe most regular distribution (“ welll-tempered ” distribution) canbe worked out for two components, A and B (say, gold and copper,or gold and silver), or for three components, A , B, and C (say,sodium, silver, and chlorine), when present in the definite amountsimplied by 1/8, 2/8, 3 / 8 , and 4/8.Thus, in the case of a 2/8mixed crystal of gold and silver (for example, Au : Ag = 1 : 3), theregular distribution for the facecentred lattice is that in whichone of the four component cubic lattices is wholly occupied by goldatoms. It is apparently only in a well-tempered state t>hat nobleatoms will be in a position to protect less noble atoms, under whichf avourablel conditions, for every noble atom present, the protection(which is not individually, but socially, organised) may extendbeyond the limits 1 : 1 (4/8) and reach the limits 1 : 3 (2/8).Theefficiency of the protection is worked out with a wealth of ingenuityCRY STALLOQRAPHY. 217it partly depends on the chemical nature of the dissolvent andpartly on the nature of the space lattice. If properly protected,i t is only the surface atoms which are within reach of the dissolvent.If, however, the temperature is sufficiently high, the boundary layerof noble atoms may lose their protective powers, on account of thehigh rate of inter-diffusion of spacelattice components, with theresult that the structure is eventually deprived of its less nobleelements.General Con,cZtcsions.-In a comparison of the behaviour of alloysand mixed crystals of salts, Tammann points out that, diffusion inthe latter is extremely slow.Alloys can be thoroughly tempereda t several hundred degrees below the melting point, but mixedcrystals of compounds, as, for example, mixtures of sodium chlorideaqd silver chloride, require more prolonged treatment’ at tempera-tures relatively nearer the melting point. The comparatively slowrate of diffusion of isomorphous compounds can also be demon-strated visually by selecting substances (say, azobenzene anddibenzyl) in which the rate of interpenetration can be measuredby the advance of the coloured border. It is also pointed out thatthe anomalous double refraction of isomorphous mixtures of bariumand lead or strontium nitrates is referable! t o the fact’ that. deposi-tion from aqueous solution occurs at’ temperatures so far belowthe melting points of the constituents that true equilibrium cannotbe subsequently attained by a process of diffusion.Many kinds ofobservations are quoted showing thatl ordinary mixed crystals arescarcely ever homogeneous; this implies that< the laws of dilutesolutions are not rigorously applicable to “ solid solutions.” 3535 The above digest, somewhat inadequate for lack of space, was compiledfrom the only available original source, the paper printed in the Zeitschriftfur anorganische und allgemcine Chenzie. A comparison of that comprehensivereview with the abstracts of his numerous papers in the GGttingen Nachrichtenreveals the fact that a certain amount of revision has been undertaken byTammann ; thus, the previous statement that solutions of vanadic acid revealan intermediate reaction limit for gold-copper mixtures at 3/8-gold appears tohave been tacitly withdrawn.Again, earlier statements that “ with thehexagonal Sb-Bi mixed crystals the rate of action of different reagents altersabruptly at multiples of 1/6 ” is likewise dropped ; in the general interpretationsuggested by Tammann, the stages, if any, should follow the rule of “ eightp,’’not of “ sixths,” since the lattice can scarcely be hexagonal, but is ratherrhombohedra1 and pseudo-cubic. Moreover, i t is difficult to see how aninterpretation which holds for alloys typified by gold-silver, the constituentsof which have the same space lattice, can be regarded as satisfactory in sucha case as magnesium-silver in which the two-constituents exhibit fundament a1cliff erences of structure218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Some Crystallographic Eesearches.The examination of the double selenates of the general formulaeR$’e(SeO&$H,O and R2Co(Se0,),,6H20, in which R representspotassium, rubidium, msium, and ammonium, has been carried outby Tutton.36 The investigation of the iron series was rendered verydifficult owing to1 the instability of ferrous selenate.The work hadto be carried out a t as low a temperature as possible. The resultsconfirm all the author’s previous conclusions concerning the regularprogressive effects of potassium, rubidium, and cesium, and alsothe close similarity of the ammonium salts. On the, other hand,doubts have been expressed by I.Langmuir 37 concerning the innateisomorphous replaceability of potassium and the ammonium radicleas being a t variance with one of the deductions from his “octettheory ” of electronic distribution.3s The author attributes theisomorphism of potassium and ammonium sulphates to the mass-effect of the sulphate radicle, and he appeals to the, difference iiistructure, as revealed by X-rays, of the cubic chlorides. It may benoted here that a similar appelal to the iodides neutralises the valueof this evidence. Langmuir’s paper, however, mainly deals withthe more general aspects of iso’morphism. Thus, he is led to expectisomorphism, as a reeult of similarity of electronic arrangement,between the following pairs of compounds, which, i t will be observed,present the same general similarity of composition as Fedorov’s“ isotectonic ” and Barker’s “ unusual ” cases : NaF,MgO,MgF,,N+O, KCl,CaS, CaCl,,K,S, RbBr,SrSe, SrBr2,Rb2Se,CsI,BaTe, Ba12,Cs2Te, N,,CO, KCNO,KN,, NaHSO,,CaHPO,,KHSO,,SrHPO,, NaC103,CaS03, KHS03,SrHP0,, Na,S,O,,C~P,O,,Na,S,07,C+P,07, MnSe0,,2HzO, FeAs0,,2H,O.Relatively few ofthe above compounds appear to have been crystallographicallyexamined, but Langmuir gives fairly convincing evidence in thecases already known. For example, Hull has a t his suggMtiondefinitely proved by means of X-rays that magnesia has the samecubic structure as sodium fluoride and rock salt.A brief paper by Bowen39 serves to clear up the apparentlyirregular optical behaviour of the mineral torbernite,which under crossed Nicols only yields red and purple interference36 A.E. H. Tutton, Phil. Trans., 1919, [A], 218, 395; A., ii, 346; Proc.37 J . Amer. Chem. SOC., 1919, 41, 1543 ; A., ii, 506.38 Idem, ibid., 868 ; A., ii, 328.39 N. L. Bowen, Anzer. J . Sci., 1919, [ivl, 48, 195.c u (UO,), (PO,),, 1 2 H,O,Boy. SOC., 1919, [A], 96, 156 ; A., ii, 417CRYSTALLOGRAPHY. 218tints, even when the sections are so thin that' grey of the first orderwould be expected. It is found that the mineral is negative forshort wave-lengths and positive for longer wave-lengths, the wave-length for isotropism being 0.515 p.An elegant study of the natural and artificial etching figures oncrystals of the calcite group of minerals 40 admirably illustrates thelaw of symmetry; in all cases, the symmetry of form and dispositionof the figure is in accordance with true rhombohedra1 symmetry.Comparative experiments on cleavage plates betray degrees ofresemblance represented by calcite, niagnesite, rhodochrosite ;chalybite; .. . calamine. Apparently not cognisant of the workof Goldschmidt and Wright, the author records some observatioiiswhich illustrate the law of polarity.41The rotatory power of sodium chlorate crystals, both when pureand when coloured with " extra China-blue," has been determinedby P e r ~ c c a , ~ ~ who observed in different azimuths variations in therotatory value of the1 coloured crystals which amounted to some25 per cent. Variations were also observed for the pure crystals;the mean value for [u]: is + 3 O 7 1 .A crystal of sulphur from a unique source (a mixture of a hotalcoholic solution of ammonium polysulphide, beiizonitrile, hydroxyl-ainine hydrochloride, and ether) has been identified, and measuredby F. R. von Bichowsky,43 who also contributes a valuable statisticalsummary of the various forms which have been observed. Theauthor remarks on the prevalence of odd numbers in the indicesat the expense of even numbers, the interpretation of which hasbeen given by G . Friedel44 as a striking example of the Bravaisprinciple.A paper by G. F. H. Smith and R . H. Solly 45 on the perplexingform development of sartorite raises fundamental questions ofcrystal structure. The authors conclude that the crystals betraythe interpenetration of three distinct space lattices, one of which ismonoclinic, the other two anorthic. No doubt the authors haveexamined the question whether the simpler interpretation, offeredby Fedorov46 for the somewhat similar case of calaverite, is relevantor no; but, in any case, it seems to the Reporter that one of thecrystals (preferably No. 1) should bel crushed up and submitted toX-radiation by the Debye-Scherrer-Hull mebhod-the angular4O A. P. Honess, Amer. J . Sci., 1918, [iv], 46, 201.41 Ann. Report, 1917, 247.4 2 E. Perucca, Nuovo Cim., 1919, [vi], 18, ii, 112 ; A., ii, 487.43 J . Washington Acad. Sci., 1919, 9, 126; A., ii, 189.4 1 Bull. Soc. franc. illin., 1907, 30, 365.45 illin. Mag., 1919, 18, 259.4F Z'eitsch. Xmjst. dilin., 1903, 37, 611220 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.differences in the space lattices, inferred by the authors, mightallow of a definite substantiation of the correctness of theirinterpretation.The announcementl, some, nine months ago, of the death of Pro-fessor E. s. Fedorov, of Petrograd, came as a heavy blow to hismany admirers. A brief appreciation is postponed from thisReport in the hope that he may still be with us, actively further-ing the progress of science by his rare genius.T. V. BARKER

ISSN:0365-6217    

DOI:10.1039/AR9191600197

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

INDEX OF ACJTHORS’ KAMESAbderhalden, E., 61, 1 61.Abel, J. J., 158, 169.Abelmann, A., 139.Abelous, J. E., 167.Abram, H. H., 10.Adams, R., 59, 69, 111.Aita, A., 32, 133.Albert, T. J., 93.Allison, V. C., 69.Aloy, J., 167.Alsberg, C. L., 191.Alway, F. J., 180.Amadori, M., 46.Ames, J. W., 179.Amin, B. M., 109, 191.Anderson, C. O., 49.Andrich, K., 20.Angel, A., 125.Angeli, A., 125.Anger, G., 78.Applebey, M. P., 50.Appleman, C. O., 194.Archibald, E. H., 52.Argo, W. L., 49.Armstrong, E. F., 62.Arthur, J. M., 194.Arthur, J. S., 51.Aschan, O., 102.Ashcroft, E. A., 32.Aston, F. W., 130.Audubert, R., 129.Auffenberg, E., 111.Auwers, K. von, 111.Bahlau, G., 34.Bal, D. V., 177.Baljet, H., 135.BarbB, E., 181.Bargellini, G., 113, 1-14.Barnes, R.E., 166.Baudisch, O., 194.Saumann, L., 164.Bauzil, 140.Bear, F. E., 183.Beck, A. J., 186, 195.Beegle, F. M., 81.BBhal, A., 133.Behrend, R., 65.Bellucci, I., 141.Benoist, L., 130.Bergmann, M., 76, 77, 191.Berry, A. E., 129.Bertrand, G., 196.Bettschart, A., 92.Bichowsky, F. R. von, 218.Bijl, A. J., 203, 206.Biltz, H., 121, 124.Bingham, E. C., 128..Birckner, V., 151.Bistrzycki, A., 92.Black, 0. F., 193.Blount, E., 194.Boas, F., 189.Boeseken, J., 77.Bottler, T., 66.Bogert, M. T., 114.Bohn, R. T., 144.Bokorny, ‘I?., 189.Boltz, G. E., 179.Bormann, K., 158.Bose, A., 141.B udet, J., 127.Bourquelot, E., 82, 191.Bousfield, W. R., 41.BOUYOUCOS, G. J., 172.Bowen, N. L., 218.Boyer, 140.Boyer, S., 36.Brehmer, E., 46.Brewster, J.F., 191.Bridel, M., 82, 191.Bridgman, J. A., 36.Brieger, K., 210.Briggs, S. H. C., 8.Bright, J. W., 175.Brinkman, R., 151.Brocq-Rousseu, 196.Bruni, G., 46.Burd, J. S., 172.Burdick, C. L., 205, 206.Burgess, H. A., 45.22222 INDEX or AUTHORS’ NAMES.Burgess, P. S., 177.Busch, M., 135.Busolt, E., 189.Cain, J. R., 144.Canals, E., 143.Cannan, R. K., 161.Caron, H., 134, 139.Carpenter, C. W., 23.Carter, E. G., 177, 178.Challenger, F., 84.Chapin, R. M., 140.Chapman, D. L., 19, 68.Chatterjee, N. R., 95.Chauvierre, M., 138.Chheveau, C., 129.Cherbuliez, E., 101.Chernoff, L. H., 191.Chiarieri, P., 173.Chick, H., 152, 165, 192.Ciamician, G., 186.Claisen, L., 91.Clark, E.P., 80.Clausmann, P., 184.Clayton. J., 174.Clewer, H. W. B., 121, 157.Colin, H., 188.Conn, H. J., 175.Conner, S. D., 133, 180.Connstein, W., 61, 168.Cooper, E. A., 146.Copaux, H., 32.Cornelius, M., 59.Couvreur, E., 189.Coward, H. F., 23.Cox, H. E., 136.Craig, T. J. I., 141.Craig, W. M., 27, 36, 142.Crocker, W., 194.Crowther, C., 152.Curtis, R. E., 175.Curtman, L. J., 139.Cutler, D. W., 180.Czensny, R., 145.Drtkin, H. D., 152, 153, 154.Dale, H. H., 152, 158.Dalmas, D., 138.Dalmer, O., 103.Dassonville, 196.Datta, R. L., 95.Davidson, J. G., 57.Davis, A. L., 28.Davis, L., 167.Davis, W. A., 191.Davisson, B. S., 132.Dawson, H. M., 13.De, R., 9.Deatrick, E. P., 184.Debye, P., 8, 38, 197, 199, 203, 208.Deerns, W.M., 77.Delezenne, C., 151.Delf, E. M., 165, 192.Demoussy, E., 185.Denham, H. G., 34, 40.Denigbs, G., 140.Dennis, L. M., 36, 47.Dey, B. B., 112.Dick, J. S., 82.Dobbie, (Sir) J. J., 30.Dobbin, L., 190.Doisy, E. A., 166.Dolgow, B., 93.Dominicis, A. Lie, 173.Dorrance, R. L., 182.Dowell, C. T., 194, 195.Dreyer, K., 65.Druce, J. G. F., 135.Drummond, J. C., 161, 165.Dudley, H. W., 152.Dufton, S. F., 136.Durrant, R. G., 43.Eckstein, H. C., 195.Eggert, J., 141.Eichel, A., 119.Eichwald, E., 61, 161.Einecke, A., 177, 181.Eisleb, O., 91.Ellis, J. H., 205.Enslow, L. H., 146.Ero, 30.Everest, A. E., 85.Eyre, J. V., 196.Fajans, K., 28.Falk, K. G., 194.Fargher, R. G., 107, 164.Fawsitt, C.E., 13, 129.Feenstra, T. P., 149.Feyer, J., 70.Fischer, E., 75, 76, 77, 78, 191.Fisher, E. A., 194.Foerster, G., 100.Fogg, H. C., 35.Folin, O., 137.Foote, H. W., 31.Forcrand, R. de, 45.Fornasir, V., 108.Fox, F. W., 84.Fox, J. J., 30.Frankel, S., 59.Frankland, P. F., 11, 74, 84.Franklin, E. C., 41.Freak, G. A., 143.Fred, E. B.,1175.Frederick, R. C., 145.Fresenius, L., 181.Freudenberg, K., 77, 120.Freund, M., 123INDEXFriedemann, W. G., 195.Fritsch, R., 151, 185.Gardner, J. A., 84.Garner, F. H., 11, 74.Gamier, M., 42.Gassmann, T., 151.Gautier, A, 184.Gericke, W. F., 180.Gerke, R. H., 128.Ghosh, J. C., 14.Ghosh, P. C., 124.Giemsa, G., 117, 134.Gierisch, W., 195.Gillespie, L.J., 179.Gillet, R., 188.Glover, T., 96.Goldschmidt, S., 50.Goldstein, H., 124.Goldthorpe, H. C., 177.Goodson, J. A., 121, 457.Goost, T., 86.Goswami, M. N., 112.Gough, W. R., 90.Graham, J. I., 130.Greaves, J. E., 177, 179.Green, H. H., 196.Greenwald, T., 164.Griebel, C., 191.Griffiths, J. J., 186.Grignard, V., 40.Grindley, H. S., 195.Gruhl, P., 43.Guareschi, I., 63, 138.Gubler, H., 110.Guglialmelli, L., 134.Guilliermond, A., 190.Gurevich, L. J . , 127.GuzmAn, J., 127.Haagen, van, 27.Haenni, Y., 38.Hageman, A. M., 48.Hager, G., 173.Halberkann, J., 117, 134.Hale, W. J., 124.Hall, A. W., 129.Hall, N. F., 28.Haller, P., 131.Halliburton, W. D., 161.Hamburger, H. J., 150.Hanke, M. T., 158.Harden, A., 165.Hardtke, O., 7.Harrington, G.T., 194.Hart, D., 139.Hartley, P., 152.Hatt, D., 67.Hauser, O., 40.Haworth, W. N., 82Heberlein, C., 196.Hedvall, J. A., 33.OF AUTHORS’ NAMES.Heidelberger, M., 117.Helferich, B., 80.Heller, G., 112.Hepworth, H., 61, 70.Herz, E. von, 40.Herzfeld, H., 40.Hess, K., 119, 120.Heward, J. A., 146.Hewitt, J. T., 135.Heyn, M., 121, 124.Hibbert, H., 60.Hilditch, T. P., 62.Hill, C. F., 181.Hilpert, S., 57.Hiltner, L., 186.Hiltner, R. S., 151.Hinsberg, O., 125.Hirst, C. T., 75, 166.Hissink, D. J., 17.Hoagland, D. R., 172, 180.Honig, M., 135.Honigschmid, O., 27, 28.Hoerenz, J., 46.Hofmann, K. A,, 67.Holm, G. E., 187, 189, 190.Holmberg, B., 73, 74.Homer, A., 129.Honess, A.P., 219.Hopkins, B. S., 27.Hopkins, F. G., ~ 6 6 .Horovitz, (Mlle.) S., 27.Hostetter, J. C., 143.Hough, G. J., 138.Howard, L. P., 180.Hudson, C. S., 74.Hull, A. W., 197, 199, 202, 203.Hume, E. M., 166.Humiston, P., 49.Hurst, L. A., 179.Hutchinson, H. B., 174.Ingold, C. K., 102.Ingvaldsen, T., 164.Irineu, D., 97.Irvine, J. C., 82.Jackson, R. F., 128.Jacobs, W. R., 117.Jacobson, C. A., 191.Jacoby, &I., 83.James, C., 35.Jander, G., 44.Jeans, J. H., 1.Jenkins, W. J., 58.Jennings, D. S., 173, 184.Joachimowitz, M., 138.Johns, C. O., 191.Johnsen, A., 207.Johnson, J., 181.Johnson, T. B., 121.Jones, D. C., 59.Jones, G. W., 60, 130.22224 INDEX OF AUTHORS' NAMES.Jones, H. I., 85.Jones, W.J., 135.Joshy, N. U., 177.Justin-Mueller, E., 137.Kamm, O., 59.Kangro, W., 20.Karrer, P., 79, 93.Kasiwagi, I., 114.Kaufmann, H. P., 57.Kaufmanri, W. von, 83.Keen, B. A., 172.Kehrmann, F., 124.Kellas, A. M., 29.Kelley, G. L., 144.Kelly, J. W., 193.Kendal1,'E. C., 159, 160.Kern, J. W., 52.Kidd, F., 184.Kiliani, H., 78, 79.Killby, L. G., 51.Kindler, K., 117.King, H., 72, 99, 117.Kling, A., 131.Kling, K., 128.Klut, H., 145.Knowles, H. B., 142.Knox, J., 10.Kohler, W., 51.Koessler, K. K., 158.Kohler, E. P., 107.Kohlschutter, V., 38.Kokubu, N., 7, 8.Kolkmeijer, N. H., 203, 206.Koller, J. P., 37.Kolthoff, I. M., 138, 139, 140, 143, 145.Komatsu, S., 74, 163.Komninos, T., 71, 93.Kornfeld, G., 182.Krause, H., 136.Kremers, F., 91.Kremers, H.C., 27.Kronberger, M., 186.Kroo, J., 7.Kruber, O., 100.Kubota, S., 158.Lacroix, A., 193.La Forge, F. B., 80.Laidlaw, P. P., 158.Laing, (Miss) M. E., 17, 68.Laird, J. S., 141.Lake, G. C., 166.Lange, N. A., 124.Langlois, G., 94.Langmuir, I., 15, 21, 28, 166, 218.Lantsberry, W. C., 4.Lapicque, L., 181.Lapworth, A., 89, 98, 161.Lasala, E., 145.Lautenschliiger, L., 122, 134.Le Blanc, M., 30.Leduc, A., 27.LBger, E., 117.Le Heux, J. W., 160.Leibbrandt, F., 120.Leitch, (Miss) G. C., 82.Lely, J. W., 149, 150.Lemmermann, O., 177, 181, 183.Lenander, K. J., 74.Leroux, D., 193.Leroux, L., 193.Leuchs, H., 122, 158.Levene, P. A., 81, 163, 164.Lewis, H. B., 165.Lewis, S.J., 129.Lewis, W. C. M., 21, 22.Lewite, A., 83.Lichtenstadt, L., 97.Liebert, G., 7.Lipman, C. B., 180.Lipman, J. G., 179.Lloyd, F. E., 184.Lowry, T. M., 10.Ludecke, K., 61, 168.Lundell, G. E. F., 142.Lynde, C. J., 133, 180.Lynn, E. V., 102.McBain, J. W., 16, 17, 68.McCool, M. M., 172.McCrosky, C. R., 140.McGuire, G., 194.McHague, J. S., 185.McKenzie, A., 72, 99.McMiller, P. R., 181.Mailhe, A., 69.Main, H., 129.Manchot, W., 58.Manning, R. J., 77.Maquenne, L., 185.Marcus, J. K., 114.Marsden, E., 4.Martinet, J., 109.Marvel, C. S., 59.Mary, Albert, 166.Mary, Alexandre, 166.Mathers, F. C., 49.Matsuo, I., 121.Mauguin, C., 40.Maxted, E. B., 26, 52.Maxwell, L. G., 144.Mayer, E. W., 190.Maze, P., 184.Mazumder, J.K., 11.Meerwein, H., 64, 92.Meighan, M. H., 130.Mellanby, E., 165.Mendel, L. B., 165, 192.Merker, H. M., 167.Meserve, S. B., 131.Meyer, A., 191.Meyer, It., 58INDEX OF AUTHORS’ NAMES. 225MMMMMMMMMMMMMMMMMeyer, S., 28.eyer, W., 58.ichael, A., 63.iers, (Sir) H. A., 198.iescher, K., 94.ikeska, L. A., 121.ilbauer, J., 144.iller, H. G., 183.Ztscherlich, E. A,, 185.Iolisch, H., 189, 193.:and, R. L., 196.Ioore, B., 194.:organ, J. D., 24.:oser, L., 31.Lountford, C. A., 13.[ueller, E. F., 46.[undler, K., 12.Nligeli, C., 79.Narain, R., 194.Neitzel, F., 137.Neller, J. R., 180.Nelson, E. K., 98.Nelson, J. M., 81.Nelson, V. E., 195.Nernst, W., 20.Neuberg, C., 167, 168, 169.Neukirchen, K., 162.Nicholls, N.A., 84.Nicholson, J. C.. 1.Nicolardot, P., 127, 142.Nierenstein, M., 77.Niggli, P., 207.Nobel’s Explosives Co., Ltd., 85.Noyes, B. A., 132.Oberfell, G. G., 131.Oelschlager, E., 1%.Onslow, M. W., 194.OrBkhoff, A., 60, 92.Orton, K. J. P., 58, 59.Osborne, T. B., 165, 192.Oshika, H., 191.Osterhout, W. J. V., 184, 188.Ostwald, Wo., 12.Ott, E., 124, 129.Owen, E. A., 206.Paneth, F., 44.Parsons, J. T., 132.Partington, J. R., 14.Pascal, P., 30, 42.Paton, D. N., 164.Patschovsky, N., 189.Payman, W., 23.Pearson, (Mrs.) L. K., 99, 161.Peck, E. C., 137.Peratoner, E., 114.Perkin, W. H., jun., 121, 122,156, 157.Perrin, J., 18.Perucca, E., 219.Pfeiffer, J. v., 109.Pfeiffer, P., 66.Pfeiffer, T., 132, 185.Philip, J.C., 129.Pickles, A., 51.Pictet, A., 83.Pierce, J. B., jun., 33Pieroni, A., 125.Piiia de Rubies, S., 142.Pincoffs, M. C., 159.Plymen, F. L., 177.Pollard, W. B., 139.Porter, C. W., 75, 166.Posternak, S., 190.Potter, R. S., 181.Powell, A. D., 137.Prescott, J. A., 175.Price, T. W., 24.Prins, H. J., 87, 88.Prior, G. T., 198.Pummerer, R., 101.Purvis, 0. N., 188.Pusch, L., 20.Pyman, F. L., 103, 107, 165.Quennessen, L., 127.Rabe, P., 117.Raistrick, H., 152.Ramann, E., 182.Rapp, 137.Raquet, D., 134, 139.Raschig, F., 42.Rather, J. B., 65.Rauchenberger, (Frl.) J., 28.Ravenna, C., 186.Ray, (Sir) P. C., 35.Reglade, A., 142.Reid, E. E., 65.Reinfurth, E., 168, 169.Rheinboldt, H., 17.’Rice, (Miss) M., 201.Richards, A.N., 158.Richards, E. H., 176, 182.Richards, (Miss) M. B., 10.Richards, T. W., 27, 28, 36, 142.Richardson, F. W., 145.Richmond, H. D., 136.Richmond, T. E., 179.Richter, F., 28.Richter, G., 182.Rideal, E. K., 130.Rindfusz, R. E., 111.Ringer, M., 167.Rintoul, W., 85.Ritter, M., 8.Rivett, A. C. D., 141.Roberts, H. S., 143.Robinson, G. W., 181.Robinson, R., 89, 122, 155, 156, 157.Rogers, L. J., 130.Roschier, R. H., 102.226 INDEX OF AUTHORS’ NAMEIS.Rosenmund, K. W., 116.Rosenstein, H., 186.ROSS, W. H., 131.Royle, F. A., 98.Ruff, O., 34.Ruggli, P., 109.Runge, C., 207.Russell, E. J., 176, 182, 183.Rutherford, (Sir) E., 1, 4, ti, 26. 2s.Ruzicka, L., 108.Ryan, H., 96.Ryan, P., 96.Sabatier, P., 69.Sakellarios, E., 57.Salkowski, E., 189Sallinger, H., 84.Salmon, E.S., 196.Salomon, H., 134.Samec, M., 194.Sameshima, J., 27, 36, 142.Sander, A., 139.Schiifer, A., 191.Schaefer, C., 210.Schaefer, K., 51.Schaum, K., 190.Schenck, H. E., 31.Scherrer, P., 16, 38, 197, 199, 203, 208.Schibsted, H., 67.Schjelderup, H., 207.Schmidt, K. W., 215.Schmutz, R., 131.Schollenberger, C. J., 132, 181.Schoorl, N., 139.Schotz, S. P., 137.Schroeter, G., 97.Schubert, M., 210.Schuppli, O., 190.Schweizer, K., 61, 168.Scott, J. W., 101.Seelig, P., 39.Sen, 12. K., 35.getllk, J., 144.Sharp, L. T., 180.Shibata, K., 114.Shibata, Y., 114.shinkle, S. D., 131.Shutt, F.T., 182.Siebert, E., 96.Siegbahn, M., 7.Simeon, F., 129.Simmermacher, W., 132, 185.Simon, L. J., 40.Simpson, T. C., 141.Singh, €3. K., 11.Singh, T. M., 178.Skinner, J. J., 181.Slyke, D. D. van, 142.Small, J. C., 136.Smith, 27.Smith, G. F. H., 219.Smith, L., 99.Snyder, R. S., 132, 181.SoEiety of Chemical Industry in Basle,Sodds, F., 1, 29.101, 190.S6deIbaum, H. G., 186.Solly, R. H., 219.Somers, R. E., 1S1.Spath, E., 123, 156, 137.Spangenberg, M., 185.Speyer, E., 123.Spielmann, P. E., 137.Spreckels, E., 96.Sprengel, A., 182.Sprietsterbach, D. O., 187, 189, 190.Stanford, E. E., 191.Stanley, F., 129.Stark, J., 7.Staudinger, H., 94.Steel’, L. L., 107.Steiger, G., 142.Stenius, J. A., 133.Stephenson, R.E., 180.Stiles, W., 184.Stobbe, H., 100.Stock, A., 39.Stoermer, R., 100.Stoklasa, J., 184.Stoll, A., 79, 190, 193.Straus, F., 106.Suchowiak, L., 128.Swanson, C. O., 195.Swarts, F., 70.Taboury, F., 45.Tague, E. L., 195.Takahashi, E., SO.Takamine, T., 7 , S.Tambor, J., 110.Tammann, G., 198, 213, 215, 217.Taylor, C. S., 189.Taylor, H. S., 130.Tcherniac, J., 64, 104.Thomas, C. C., 196.Thomas, J., 55.Thomson, (Sir) J. J., 2.Thorpe, J. F., 66, 67, 90, 102.Tingle, A., 138.Titley, A. F., 17, 68.Toeplitz, O., 30‘7.Tottingham, W. E., 186.Traube, I., 186.Traube, W., 46.Trieschmann, J. E., lC2.True, R. H., 193.Trumbull, H. L., 131.Tsakalotos, D. E., 138.Tschudi, P., 124.Tutton, A. E. H., 218.Twyman, F., 129INDEX OF AUTHORS’ NAMES.227Urbain, E., 40.Ursprung, A., 188.Utheim, S., 70.Vegard, L., 207.Velardi, G., 136.Verley, A., 60.Viehoever, A., 13 1.Villumbrales, V., 143.Voegtlin, C., 166.Vogelenzang, E. H., 140.Voigt, W., 207.Voisenet, E., 162.Voorhees, V., 69.Vorlander, D., 88, 95, 96, 109.Waentig, P., 195.Waksman, S. A., 174, 175.Wasicky, R., 138.Waynick, D. D., 132.Wedekind, E., 17, 86.Wehmer, C., 167, 187.Weidmann, H., 79.Weinhagen, A. B., 120.Weinland, R. F., 43.Weissgerber, R., 100, 101.Weissmann, H., 183.Weitz, E., 94.Wells, P. V., 128.Werner, E. A., 85, 86, 87.Werner, F. F., 141.West, C. J., 164.West, R. M., 187, 189, 190.Wester, D. H., 139.Wheatley, R., 85.Wheeler, A. S., 101.Wheeler, R. V., 23, 24.Wherry, E. T., 180.Whiston, J. R. H., 19.White, A. G., 24.Wichers, E., 127.Wichmann, A., 193.Wichmann, H. J., 151.Wieland, H., 57, 93.Wiley, J. A., 144.Williams, A. M., 15, 166.Williams, J. G., 142.Williams, J. J., 187, 189, 190..Williams, M., 184.Willstatter, R., 67, 79, 190, 193.Wilson, J. A., 173.Wilson, W. H., 173.Windaus, A., 103, 162.Winkler, L. W., 142, 143.Winternitz, E., 44.Winterstein, E., 120, 151, 185.Wohl, A., 85.Wohlgemuth, J., 84.Wolf, K., 142.Wolff, H., 134.Wolman, A., 146.Wood, J. K., 72, 99.Wood, J. T., 167.Woodman, H. E., 152.Workman, A. C., 183.Wormald, L. K., 196.Woudstra, H. W., 17.Wray, E., 134.Wren, H., 72.Wright, W. C., 144.Wunderlich, F., 46.Yoshida, U., 8.Zepfel, L., 141.Zoch, I., 182.Zwaademaker, €I., 148, 149, 150

ISSN:0365-6217    

DOI:10.1039/AR9191600221

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

INDEX OF SUBJECTSAcetobromoamide, brolnination with,85.Acetobromoglucose, action of silversalicylate on, 79.Acetone, thiocymo-, 64, 104.Acetophenone, o-bromo-, characterisa-tion of acids by, 65.Acetylene, combination of mercuricchloride and, 68.polymerisation of, 57.estimation of, 131.Acids, aliphatic, characterisation of,Aconitine, detection of, 135.Adsorption, 14.Affinity, duplex, and vttlency, 8.Agricultural analysis, 131.Alcohols and their derivatives, 59.Aldehydes, 63.Alkali fluorosulphonates, 46.65.organic, estimation of, 136.detection of, 133.metals, compounds of ammonia and,Alkalinity, detection of, 138.Alkaloids, origin of, from amino-acids,action of diazonium compounds on,anhalonium (cactus), 123.of the areca nut, 120.cinchona, 1 17.of the pomegranate tree, 119.various, 121.estimation of, 137.Alkyl iodides, preparation of, 69.N-Alkyloximes, constitution of, 94.Alloys, properties of, 213.Ally1 alcohol, 59.Allylphenols, formation of, 9 1.o-Allylphenols, 11 1.Amines, separation of, 85.phenolic, detection of, 134.Amino-acids, 153.origin of alkaloids from, 155.Aminosulphonic acid, salts of, 46.41.155.122.229Ammonia, combustion of, 42.metallic compounds of, 41.albuminoid, estimation of, in water,145.Ammonium fluorosulphonate, 46.tert.-Amy1 alcohol, 59.Analysis, agricultural, 13 1.electrochemical, 143.inorgamc, 138.microchemical, 139.organic, 133.physical, 127.water, 145.123, 157.g=, 129.Anhaline, identity of, with hordenine,Anhalonium alkaloids, 123.Anthocyanins, 114.Antimonic acids, 44.Areca nut, alkaloids of the, 120.Arecaidine and arecaine, 120.Arecoline, 120.Arginine, 164.Argon, atomic weight of, 27.Arsenic, yellow, 43.Arsenic acid, estimation of, 140, 142.Arsenious acid, reduction of, 43.Arylthiocarbimides, action of benzylicAtom, constitution of the, 3, 28.Atomic disintegration, 4.structure, 1, 29, 208.weights, 27.oxide, double compounds of, 43.acid on, 92.Bacteria, 196.Barium peroxide, action of heat on, 33.Benzaldehyde, 2 : 4 : 6-trihydroxy-, 93.Benzotrichloride, nitration of, 95.Benzylic acid, action of, on arylthio-Berberine, estimation of, 138.Beryl, extraction of glucinum from, 32.Betonicine, 121, 158.carbimides, 92230 INDEX OF SUBJECTS.Bismuth hydride, 44.detection of, 140.estimation of, 141.Boron, atomic weight of, 27.Bromides, estimation of, 136.Bromoplatinic acid ammonium salt,Brucine, action of nitric acid on, 122.Burgundy mixture, composition of,Butyl alcohol, 59.solubility of, 51.196.Cacotheline, 122.Cactus alkaloids, 123.Cadmium suboxides, 34.Calcite group of minerals, 219.Calcium, estimation of, 142.hypobromite, basic, 51.phosphates, 32.Capsaicin, 98.Carbazines, 124.Carbohydrates, 75.Carbon, amorphous, 38.estimation of, in soil, 131.monoxide, estimation of, 130.dioxide, estimation of, 142, 145.Carbonyl chloride, preparation of, 40.Carborundum, crystalline structure of,206.Caseinogen, 152.Catalysis, 62.Cellulose, 83.Chalcopyrite, crystalline structure of,205.Charcoal, crystalline structure of, 205.Chemical change and radiant energy,reversible, influence of tempera-in steel, 144.estimation of, 131.sulphide, decomposition of, 39.in heterogeneous systems, 21.18.ture on, 22.Chlorination, 69.Chlorine, combination of hydrogen and,combination of sulphur dioxide and,rate of absorption of, by water, 146.monoxide, 50.19.20.Chlorites, 51.Chloroform, preparation of, 70.Chloroiridic acid, ammonium salt,solubility of, 51.Chloropicrin, reactions of, 84.Chloroplatinic acid, ammonium salt,solubility of, 51.Cholesterol, 103, 162.Cholic acid, 162.Choline, physiological action of, 160.Chroman, synthesis of, 111.Chromium, estimation of 144.Cinchona alkaloids, 1 17.Coal gas, effect of, on pla.nts, 187.B-Collidine, synthesis of, 108.Colloids, 16.Colouring matters with an asymmetricCopper, alloys of gold with, 213.carbon atom, 166.sulphates, 3 1.cuprous oxide, preparation of yellow,31.Coumaran, synthesis of, 111.Coumarin group, the, 109.Croton gubouga, investigation of barkof, 121.Cryptopine, 121.Crystal structure, 218.Cuorin, 163.Cyanates, estimation of, 136.Cyanides, estimation of, 136.Cytisine, 123.Cytisoline, synthesis of, 123.Datiscetin, synthesis of, 114.Diacetonamine, preparation of, 85.a€-Dialdehydes, 63.Diazomethane, methylation with, 86.Diazonium compounds, action of, onalkaloids, 122.Diffusion of solids, 2 13.Digitalin, detection of, 135.Dilution law, electrolytes and the, 13.Dimethylaniline, condensation ofo-phthalaldehyde and, 94.Dimethylnaphthalenes, 100.Diphenyl disel enide, di - m -ni tro - , anddi-m-amino-, 103.Diphenylamine, nitro-derivatives of,96.Diphenyl-N-phenylnitrone, 95.Disaccharides, 82.Dispersion, rotatory, 10.Egg -albumin, 152.Electrical field, spectral emission in an,Electrochemical analysis, 143.Electrolytes and the dilution law, 13.Energy, radiant, and chemical change,Enzymes, 166, 193.Equilibrium, chemicaltl, influence oftemperature on, 22.Ether, estimation of, in alcohol, 135.Ethyl alcohol, 8-amino-, 59.Ethylene, nitro-, 57.Eugenol, synthesis of, 91.Euglobin, 152.Eukodal, 123.7.18.Fats, synthetic, 161.unsaturated, hydrogenation of, 62INDEX O F SUBJECTS.231Feeding stuffs, 194.Fenchenes, 102.Fermentation, 166.Ferrocyanides, estimation of, 143.Fertilisers, 183.Flavanones and flavones, 110.Flavone series, the, 113.Floridose, 80.Flowers, colour variation in, 116.Fluorine, preparation of, 49.Fluorosulphonic acid, salts of , 46.Food substances, accessory, 165.Formaldehyde, production of, 67.Freezing point of solutions, applicationin quantitative analysis, l29.Fructose, mutarotation of, 8 1.Fungicides, 196.Gallium and its compounds, 33.atomic weight of, 27.separation of, 142.dissolved in water, estimation of,Gas analysis, 129.Gases, explosive, ignition of, 24.145.inflammability of , 23.Gaseous mixtures, ignition of, 24.Gasoline, estimation of, 131.Gentiobiose, 82.Geraniol, constitution of, 60.Glucin my extraction of, from beryl,Glucogallin, 76.Glucosamine , 8 1.Glucose, mutarotation of, 81.Glucosides, 78.Glutaconic acids, isomerism of, 66.Glutamic acid, B-hydroxy-, 155.Glutaric acid, a-amino-8-hydrory-,Glycerol and its derivatives, 60, 161,Glycerophosphoric acids, 61.Glyceryl trinitrate, 61.Glycols, 60.Glyoxalines, 107.Gold, alloys of copper and silver with,213.detection of, 139.Graphite, 38, 203.Graphitic acid, 38.Grignard reagents, 70.Guaiaretic acid, 97.Guaiene, 97, 101.Gulonolactone, 80.Guvacine and guvacoline, 120.32.estimation of, 32.154.168.biochemical degradation of, 162.Halogen compounds, aliphatic, 68.Halogens, estimation of, 135, 141, 144.Harmine and harmaline, 122, 156.Hexacyanogen, 124.Histamine, 158.Histidine, 164.Hordenine, identity of, with anhaline,123, 157.Hormones, 159.Humus, estimation of, in soil, 181.Hydrastinine, new synthesis of, 116.Hydrobromic acid, preparation of, 5 1.Hydrocarbons, 56.Hydrogen, combination of chlorineand, 19.peroxide, estimation of, 140.sulphide, absorption of,by palladium," poisoning " of palladium by, 26.Hygric acid, 4-hydroxy-, 121, 157.Hyoscine, optically active forms of,Hypochlorous acid, preparation of, 50.Hypophosphites, estimation of, 140.52.72, 117.Ignition-temperatures, determinationof, 24.Indican, extraction of, from plants,109, 191.Indirubins, 109.Indium, separation of gallium and, 36.Indole group, the, 109.Inflammability of gaseous mixtures,Inorganic analysis, 138.Insecticides, 196.Invertase, 166.Iodides, estimation of, 144.Iodination, 95.Iodine, occurrence of, in plants, 151.Iodometry, 140.Iron, crystalline structure of, 197.Isatin, conversion of, into 2 : 3-di-Isomorphism, 2 18.23.hydroxyquinoline, 112.Juglone, tribromo-, 101.Kephalin 164.Keto - aldehydes, 63.Ketones, 63.Lead, alloys of magnesium and, 32.atomic weights of isotopes of, 28.compounds, effect of, on vegetation,salts of, 40.detection of, 139.estimation of, 144.186.Lecithin, 164.Lime-requirement of soil, estimation of,133232 INDEX OF SUBJECTS.Linamarin, 78.Lipoids, 163.Magnesium, crystalline structure of,E-Mandelic acid, ethyl ester, hydrolysisof, 72.Manganese, detection of, 139.Manures, 183.Mercury, detection of, 139.203.alloys of lead and, 32.estimation of, 142.mercuric chloride, action of thio-combination of acetylene and,fluoride, preparation of, 34.nitrite, action of thioamides on, 35.sulphoxyni tri te, 3 5.mercurous fluoride, action of chlorineon, 35.Methane, tetranitro-, 58.Methoxyl group, estimation of the, 136.Methylamine, preparation of, 84.dl-Methylconhydrinone, 11 9.Methylguanidine, 164.Methylisopelletierine, 11 9.Methylrhodims, 64, 105.Methyluric acids, 124.Mezcaline, synthesis of, 123, 157.Microchemical analysis, 139.Molecular rearrangement, 91.Molybdenum, estimation of, 142.Monosaccharides and their derivat'ves,Morphine, detection of, 134.amides on, 35.58.weights, 29.80.estimation of, 138.$-1 : 8-isoNaphthoxazone, 113.3-Naphthoylbenzoic acid, 1 : 6-di-hydroxy-, 101.Nickel, estimation of, 141.Nitrification in soil, 178.Nitrogen, atomic weight of, 27.disintegration of, 4, 26, 28.compounds, aliphatic, 84.estimation of, in soil, 132.peroxide, density of, 41.nitric acid, density of mixtures ofnitrates, estimation of, in water, 145.nitrous acid, estimation of, 141.Nitro-group, estimation of the, 135.Nitrones, 94.Nutrients, absorption of, by plants,184.nitrogen peroxide and, 41.Occlusion, 16.Optical activity, 71.dispersion, 10.rotatory power, 11.Organic analysis, 133.compounds, oxidation of, by silveroxide, 65.aromatic, substitution in, 90, 95.theory of constitution of, 87.Oscine, 117.Osmotic properties of disperse systems,12.Oxalic acid, detection of, 134.Oxycodeinone, 123.Oxydases, 193.Oxydihydrocodeinone, 123.Oxygen, estimation of, 130.Ozone, estimation of, 130.estimation of, 136.Palau, 127.Palladium, as a catalyst, 26.absorption of hydrogen sulphide by,Parazenes, 125.Particles, ultramicroscopic measure-a -Particles, disintegration produced by,isopelletierine, occurrence of, 120.Pepsin, 167.Perchlorates, estimation of, 142.Peroxydase, 193.Phenacetin, estimation of, 137.Phenyltrimethylammonium salts, bro-mination and nitration of, 96.Phloroglucinol, synthesis of, 7 1, 93.Phosphorus, estimation of organic, insoil, 132.phosphites, estimation of, 140.superphosphates, investigation of,Photochemical reactions, 19.o-Phthalaldehyde, condensation of di-Physical analysis, 127.Pinac one -pinacoline transformation,d-Pinene, 102.Plants, absorption of nutrients by, 184.52.ment of size of, 128.4, 28.32.methylaniline and, 94.92.action of coal gas on, 187.composition of, 187.constituents of, 187.growth of, 187.nutrition of, 184.poisons of, 186.reactions in, 192.Platinum, substitutes for, 127.Polysaccharides, 83.Pomegranate tree, alkaloids of the, 1 19.Potassium, biological importance andd-Propylene glycol, 62, 162.Proteins, 151.Purine group, the, 121.Pyknometer, gas, 128.radioactivity of, 148INDEX OF SUBJECTS.233Pyrazoline group, the, 106.Pyrimidines, 121.Pyrrole-black, preparation of, 125.Quinine, detection of, 134.Quinoline, 2 : 3-dihydroxy-, 112.Quinolinic acid, dyes from, 124.Radiant energy, chemical change and,Radiation hypothesis, application of,Radium-C, scintillations given by, 6.Rain-water, 182.X-Ray investigations, 197, 199, 208.X-Rays, use of, in analysis, 129.Refractofneters, 129.Resins, constituents of, 97.8-Resorcylaldehyde, 93.Rhamnose, 80.Rhodims, 64, 104.Rhotanium, 127.Rotatory dispersion, 10.power, optical, 11.18.to heterogeneous reactions, 21.spectra, 7.Saponins, 191.Saxtorite, crystalline form of, 219.Scandium, atomic weight of, 28.Schiff bases, action of potassiumScutellarein, constitution of, 113, 114.Selenium, occurrence of, in animals,cyanate on, 124.151.compouflds, 47.organic, 103, 125.selenates, cystallographic investi -gation of, 218.Semicarbazide, action of, on ketones,63.Sesquiterpene, new, 102.Silver, alloys of gold with, 213.estimation of, 141.chloride, mixed crystals of sodiumoxide, oxidation of organic com-Soap solutions, properties of, 17, 68.Soda-asbestos, use of, for absorbingSodium chlorate, rotatory power ofchloride, mixed crystals of silverhypochlorite, 50.sulphates, 30, 31.chemistry of, 171.constituents of, 181.effect of salts on, 177.nitrification in, 178.chloride and, 215.pounds by, 65.carbon dioxide, 130.crystals of, 219.chloride and, 215.Soil, biochemical changes in, 174.Soil, protozoa ,in, 179.Solids,estimation of, in water, 145.Solutions, freezing point of, applicationin quantitative analysis, 129.Spectra, emission, and atomic struc-ture, 2.X-ray, 7.Spectral emission in an electricalfield, 7.lines, origin of, 2.Spectrophotometer, new form of, 129.Spiro -compounds, 102.Starch, 83.Starch-iodine reaction, 138.Stark effect, 7.Still-head, new type of, 136.Strontium peroxide, preparation of, 33.Styryl methyl ketone, 94.Succinic acid, halogen compounds of,Sugars, estimation of, 136.Sulphur, crystalline form of, 219.molecular weight of, 29.absorption of light by vapour of, 30.boiling point of, 45.monochlorids, 45.dioxide,action of, on alkali iodides,combination of chlorine and, 20.estimation of, 131.acids, detection of, 139.sulphurous acid, estimation of, 140,sulphates, estimation of, 141.Sulphonyl chlorides, estimation of, 137.Sulphuryl fluoride, preparation of , 46.Superphosphates.See under Phos-Systems, disperse, osmotic propertiessurveys, 181.estimation of humus in, 181.soluble, estimation of, 136.73.45.141.phorus.of, 12.heterogeneous, catalysis in, 2 1.Tannins, investigations on, 76, 77.Tellurium sulphide, 48.Terpene, new bicyclic, 102.apy6 -Tetramethylhexoic acid, synthesisTe traphenyl -N- phen yhi trene, 95.Thebaine, oxidation of, 123.Thiophen, detection of, 134.Thorium, atomic weight of, 27.Thyroxin, 159.Tin, crystalline structure of, 206.Tissues, animal, constituents of, 163.Titration, electrometric, 143.Torbenite, 218.Tropic acids, 72, 99.Truxillic acids, 99.of, 67.estimation of, 137.234 INDEX OF SUBJECTS.Truxone, 100.Trypsin, purification of, 167.Turicine, 121, 158.Ultramicroscopic particles, measure-ment of size of, 128.Urea, constitution of, 86.Uretidone, 125.Valency and duplex affinity, 8.Valeraldeh y de, y -hy dr oxy - , 80.Vanadium, estimation of, 144.Vegetation, effect of lead compoundsViscosimeters, calibration of, 127.Viscosit,y value, 128.Vitamines, 165, 192.on, 186.Water, analysis of, 145.Weights, atomic, 27.rain-, 182.molecular, 29.Yttrium, atomic weight of, 27.Zinc, occurrence of, in animal cells andf ormate, production of f orma-ldehydeZingerone, pungency of compoundsZirconium, estimation of, 141.foods, 151.from, 68.related to, 99.compounds, 40.PRIXTED IN GREAT BRITAIN BIT R . CL\Y AND SONS, LTD.,BRCNSWICK STREET, GTi>fFORD STREET, S.E. I , AND BUSGAY, SUFFOLK

ISSN:0365-6217    

DOI:10.1039/AR9191600229

出版商:RSC    

年代:1919

数据来源: RSC