摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMISTRYANNUAL REPORTSE. C. C. BALY, C.B.E., F.R.S.G . I~ARGER, M.A., D Sc., F.R.S.J . KENNRR, Ph.D., D.Sc.ON THEPROGRESS OF CHEMISTRYF O E l 1 9 2 1 .ISSUED BY THE CHEMICAI, SOCIETY.R. H. PICKARD, D.Sc., Ph.D., F.R.S.R. ROBINSON, D.Sc., F.R.S.E. J. RUSSELL, 0.n. E., D.Sc., F.R.S.$ommiitre o f @ublicatioit :A. J. ALLMAND, M.C., D.Sc.0. L. BRAHY, D.Sc.A. W. CKOYSLEY, C.M.G., C.B.E.,C. H. DESCH, D.Sc., Ph.D.M. 0. FORSTER, D.Sc., Ph.D., F.R.S.J. T. HEwITr, M.A., D.Sc., Ph.D.,J. C. IRVINF,, C.B.E., D.Sc., F.R.S.C. A. KEANE, D.Sc., Ph.D.D.Sc., F.R.S.F. R.S.T. 11. I,owi:v, C.TZ.E., D.Sc., F.R.S.J . I. 0. MASSON, M.13.E., D.Sc.G. T. MORGAN, O.B.E., D.Sc., F.R.S.T. S. PATTERSOX, D Sc , P1i.D.J. 0.PHILIP, O.B.E., D.Sc., Ph.D.,N. V. RTDGWICK, M.A., Sc.D.J. F. THOILPE, C.B.E., D.Sc., F.R.S.Sir JAMES WALKER, D.Sc., LL.D.,F. R. S.F.R.S.@bitor :A . J. GREENAWAY.&,&stnnt 6,biior :CLAEESCE SMITH, D. Sc.3ssistairt :A. A. ELDRIDGE, B.Sc.&rbexer :MARGARET LE PLA, B.Sc.VOl. XVIII.LONDON :GURNEY & JACKSON, 33 PATERNOSTER ROW, E.C. 4.1922PRINTED IN GREAT BRITAIN BY~ L I C H A R D CLAY B Soss, LIAIITUI,BUNGAY, SUFFOLKCONTENTS.PAGEGENERAL AND PHYSICAL CHEMISTRY. By J. R. PARTINGTON,M.B.E., D.Sc. . . . . . . . . . . 1INORGANIC CHEMISTRY. By E. C. C. BALY, C.B.E, B.R S. . . 30ORGANIC CHEMISTRY :-Part I.-ALIPHATIC DIVISION. By R. H. PICKARD, D.Sc., Pli.D., F.R.S. 60Part II.-HOMOCYCLIC DIVISION.By R. ROBIXSOX, TI.&., P.R.S. . 77Part lII.-HETERoCYCLTC DIVISION. By J. KENNER, I'h.D., D.Sc. . 107ANALYTICAL CHEMISTRY. By C. AIh-SWOR'rH MITCHELL, M. A. . I46PHYSIOLOGICAL CHEMISTRY. By G. RARGER, M.A., D.Sc., F.R.S. 166AGRICULTURAL CH E M ISTliY AND VEGETABLE PHYSIOLOGY.By E. J. RUSSELL, O.B.E., D.Sc., P.R.S. . . . . 192CRYSTALLOGRAPHY AND MINERALOGY. By A. E. H. TUTTOX,M.A., D.Sc., P.R.S. . . . . * . . . 2 1 ABBREVIATED TITLE.A . . . . .Acta Med. Scanclimv. .Amer. Chena. J. . .Amer. J. Rot. . .Amer. J. Physiol. .Amer. J. Sci. . .Anal. Fis. Quinz. .Analyst . . .Annalen . . .Awn. Bot. . . .Ann. Chiin. nncrl. .Ann. Falsv. . .A m . Inst. Padew .Ann. Physik . .Ann. Report . .Ann. Sci. Agron. .Ann. sci. Univ.Jassy .Apoth. Ztg. . .Arch. exp. Path. Phami.Arch. Farm. merim. Xci.Arch. Phnrm. . .ArchSchiJs u. l’ropenhygiev cA~kiv. Ketn. J f i n . Geol. .Astrophys. J. . . .Atli 11. Accad. Lincei . .Beitl. Ann. P h p . . .3 e ~ . . . . . ,Bcr. DeqLt. bot. Ges. . .Ber. Deut. pharm. Ges. .Berl. Klin. Wochenschr. .Biochem. J. . . .Biochem Z. . . .L’re?insto$lChenz. . .Brit. Med. J. . . .Brit. Pat. . . . .Bu2. Xoc. Chim. Ronzhzia .BUZZ. Acad. roy. Belg. .Bull. Jard. bot. Buitenzorg.Bull. SOC. chim , .BUZZ. SOC. chim. Belg. ,REFERENCES.TABLE OF ABBREVIATIONS EMPLOYED IN THE* Tlic year is not inserted in refereuces t o 1921.JOURNAL.Abstiacts in Journal of the Chemical Society.”Acta Medica Scandinavica.American Chemical Journal.American Journal of Botany.American Journal of Physiology.American Journal of Science.Anales de la Sociedad EspanGla Fisica y Quimica.The Analyst.Justus Liebig’s Annalen cier Chemie.Annals of Botany.Annalrs de Chimie anal) tique appliqde A 1’IndustriesAnnales des Falsifications.Annales de 1’Institut Pasteur.Annalen der Physik.Annual Reports of the Chemical Society.Annales de la science agronomiquc franqaise etb,tranghre.Annales scientifiqnes de 1’Universiti: de Jassy.A potheker-Zeitung.Archiv fiir experirnentelle Patliologie und Pharma-Archivio di Farniacologia sperimcntalc c Scienze affini.Archiv der Pharmazie.Arcliiv Schiffs-nnd Tropen-Hygiene.Arkiv for Kemi, Mineralogi ocli Geologi.Astrophysical Jownnl.At ti della Reale Accademia (lei Lincei.Rcibldtter zu den Aniialeii der Physik.Btq-iclite der Deutschen ( ’hemischen Gesellschaft.Hericlite dcr Deutsclien botiinisclien Gesellschaft.Berichte tlcr Deutsclien pharmazeutisclien Gesell-Berliner Klinisclie Wochcnsclirift.The I3iochen~ical Journal.Biocheiiiische Zeitschrift.13rennstoff Chemie.British Medical Journal.H ritish Patent.13uletinul Societ&tei de Chimie din Roni8nia.Acadernie royale de Belgique-Bulletin de la ClasseBulletin du Jardin lrotai~ique de Buitenzorg.Eulletin de la SocidtB chimique de Prance.Bulletin de la SociBtd chimiyne de Helgiquc.h YAciiculture, 3~ la Pharniacie et B la Riologie.kol ogie.scliaft.des Sciencesviii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.Bidl. Soc.chim. Biol. .Bull. Xoc. Ind. Mdhouse .Canedim Chem. J. . .Centr. Bakt. Par. . .Chma. Listy . . .C?ie?n. and illel. Eng. . .Chem. News . . .Chem. Weckblad . .C'hern. Z q . . . .Chem. Zentr. . . .C'ompt. rend. . .D.B.-P. . . . .Deutsch. Curt. Ztg. . .Eng. ancl MCn. J. . .Fer.meiitforsch. . . .Cnzzetta , . . .Ges. Abhancll. Kemit. KoJdeGiorn. C'h iin. Ind. AppZ. .Helr. (:him. Actn . .Int. z. -lhtccl. . . .Jahrb. Man. . . .Jap. Put. . . . .J. Agric. Ecs. . . .J. Agric. Sci. . . .J. Anzrr. Chcm Soc. . .J. Niol. Chem . . .J. Cheni. Ad. Jcqma (or?'07Cyo) . * . .J. C?mn. Met. Soc. S. AfrirtlJ. Chiin. phiis. . . .J. C'oll. E:&g. TolLyo . .J. CoZl. Sci. Tokyo . .J. Franklin Inst.. .J. Den. PILysiol. . . .J. Id. h'ng C?bein. . .J. Landw. . . . .J. iilin. Agric. . . .J. PJiarm. Cliint. . .J. Plwmn. Soc. Jq~an. .J. P?qszcccl G'?be?ra. . .J. Physiol. . . .J. p r . C h m . . . .,I. Roq. Soc. New ASozLtlLWales . . . .J. S . African Assoc. Anal.C?Lem. . . . .J . SOC. Chem. Ind. . .J. SOC. Dyem and Col. .J . Tokyo Chem. Sac. . .J . TVmhington Acad. Sci. .KoX Cheni. Beihefis . .Kolloid Z. . . . .Lnx~Jw. Juhrb. . . .Landw. Yersuchs-Stat. .J. A G ~ . Hart. AFIoc. . .JOURHAL.Bulletin de la SociBte' de Cliimie biologique.Bulletin de la Soci6tB Industrielle de Mulhonse.Canadian Chemical Journal.Ceiitralblatt fur Balrteriologie, Parasitenkunde undInfektionskrank heiten.Cheinick6 Listy pro v%du a 1n4mysl.Cheinical and Metallurgical Engivecring.Chemical News.Chcmiscli Weekblod.Cheniiker Zeitung.Chernisches Zen tmlblatt.Coniptes rendus liebdoniadaires des SEances deDeutsches Reichs-Patent.Dentsche Cartcn-Zeitung.Engineering and Mining Journal.Fernientforschung.Gazzetta chimica italiaiiaGesanimelte Abhandlungen zur I<eiintiiis der Iiolile.Giornale di Chimica Industriale ed Applicata.EIelvetica Chimica Rcta.Iiitcrnationalc Zeitschrift fiir Metallographic.Neues Jahrbnch fiir Mineralogie, Geologie iuid,Japanese Patent..Journal of Agricultural Research.Journal of Agricultural Science.Journal of the American Chemical Society.Jouinal of Biological Chemistry..Tournal of Chemical Industry, Japan.,Tonrid of the Chemical, Metalliugical, and MiningSociety of South Africa.Journal de Chiinie physique.Journal of the College of Engineering, University ofJournal of the College of Science, Imperial UniversityJouriial of the Franklin Institute.Jonrnal of General Physiology.Journal of Illdustrial and E!igiiieering Chemistry.Journal fur Landwirtschaft.Joiirrial of the Ministry of Agriculture.Journal tie I'?iarmacie e t dr Chimie.Journal of the Pharmaceutical Society of Japan.Journal of Physical Chemistry.Journal of l'hysiolopy..Tourid fur praktische Cheniie..Tournal of the Royal Horticultnral Society.Jorirnal and Proceedings of the Royal Society of NewJournal of the South African Association of AnalyticalJouriial of the Society of Chemical Industry.Journal of the Society of Dyers and Colourists.Journal of the Tokyo Chemical Sorirty.Journal of the Washington Academy of Sciences.Kolloidchemische Eeihefte.Iiolloitl Zritschrift.Landwirtschaftliclie Jahrbucher.Die Lmdwirtschaftlich en Versuchs-Stationen.1'Acaddmie des Sciences.Ynlaeontologie.Tokyo.of Tokyo.South Wales.ChemistsTABLE OF ABBREVIATZONS EMPLOYED IN THE REFERENCES.i XABBREVIATED TITLE.Jfedd. K. Vetenr kapsaknd.Nobel-Inst. . . .Alm. Coll. Sci. Ky6l6 ,M c m . Manchcster Phil. Soc.Metall u..Erz . . .Min. Mag. . . ,Monatsh. . . . .Nuovo Cim. . . .afvers. Fiiiska Vet. -SOL .Perf. and Essestt. Oil. Bee. .P$iiyer's Archiv . . .Pharm. J. . . . .Pharm. Weekblad . .Pharm. 2cntr.-h. . .Phillipine J.Xci. . .Phil. Mag. . . ,Phil. /'ran$. . . .Physical Reu. . . .Physiknl. 2. . . .Physiol. Abstr. . . .Proc. Cam. PhiZ. SOC. . .Proc. K. Aknd. Weteiwh.Amstcrdnm . . .Proc. Nat. Acad. Xci. . .Proc. Physical SOC. . .Proc. &oy. SOC. . . .Proc. Xoy. Xoc. Edin. . .Izec. trav. clziin. . . .h'ev. G h . Mat, CoZ. . .Schzoeiz. Apoth. Zfg. . .Silzungsbcr. Prezsss. Akad.Wiss. Berlin . . .Skand. Arch. Physiol. .Soil Xci. , . . .Stahl ZL.. Eisen . . .Staz. sper. agr. itnl. . .Xvensk. Kem. Tidskr. . .T . . . . . .Texas Agric. Expt. StationBdl. . . . .Trans. Faraday Xoc. . .Yer. Deist. Phgsilcal. Ges. .Z. anal. Chem. . . .Z. angew. Chem. . .Z. anorg. Chern. , . .2. Biol. . .2. Deut. Ol'Fett ind. . .Z. Eleklrochem.. . .Z. yes. Schiess-u. Spreny-stoflcl. f . . .Z. Hyg. . . . .JOURNAL.hleddelanden fr&n Kongl-VetenskapsakademiensMemoirs of the Collage of Science, Iiyot6 ImperialMemnirs and Proceedings of the Manchester LiteraryMetall und Erz.Mineralogical Magazine and Journal of theMonatshefte fdr Cheniie und verwandte Theilc andererI1 Suovo Ciniento.ofverhigt af Finska Vetenskaps-Societetens Fiirhand-lingar, H el singfors.Perfumery and Essential Oil Record.Arcliiv fiir die gesarnmte Physiologie des hlenschenund dcr Thiere.Pharmaceutical J ouriial.Pharinaceutiscli \\'eekblad.Pharniazeutische Zentralhalle.Phillir>ine Journal of Science.Nobel- I11 s t i t n t .University.and Philosop1:ical Society. ,Mineralogical Society.Wissensch aften.Philoiophical Magazine (The London, Edinburgh andDublin).Philosophical Transactions of the Royal Society ofLondoii.Physical Ileview.Physiknlische Zeitschrift.Physiological Abstracts.Proceedings of the Cambridge Philosophical Society.Koninklijke Akadeniie van Wetenschappen te Amster-darn.Proceedings (English version).I'rocrcdings of the Natignal Academy of Sciences.Proceedings of the Physical Society of London.Proceedings of the Royal Society.Proceedings of the Royal Society of Edinburgh.Recueil des travaux cijiiniques des Fays-Bas et de laRevus GBnQrale des Matieres Colorantes.Schweizerische Apothekcr Zeitung.Sitzuiiasberichte der Preussischen Akadeniie der118ssenschaften zu Berlin.Skandinavisches Archiv fiir Physiologie.Soil Science.Stahl nnd Eisen.Stazioni sperimentali agrarie italiane.Svensk Keinist Tidskrift.Transactions of the Chemical Society.Bulletins of the Texas Agricultural ExperinleiitTransactions of the Faraday Society.Verhandlungcn der deutschen physiltalischcn Gesell-Zeitschrift fur analytische Chemie.Zeitschrift fur angewandte Chemie.Zeitschrift fiir anorganische uud allgemeine Cliemiu.Zeitsbhrift fiir Biologic.Zeitschrift der deutschen 01-und Fett-Industrie.Zeitschrift fur Elektrochemie.Zeitschrift fiir das gesammte Schiess-und Spreng-Zeitschrift fiir Hygiene und Infektionskranklieiten.Belgique.Station.schaft,.stofhesenx TABLE OF ABBREVIATIONS EMPLOYED I N THE REFERENCES.ARBREVIATED TITLE.2.Kryst. M i n . . . .Z. iVetallku?zde . . .Z. Nalw.-Gcnussm. . .2. Ofe7ttZ. Chem. . .2. Physik . . . .Z. pltysikal. Chem. . .2. plzysikal. Chein. Uttterr.Z. yhysiol. CJzem. . .JOUIWAL.Zeitschrift fur Krystallogrnphie und hfineralogie.Zeitschrift fur Metallkunde.Zeitschrift fur Untersuchung der Nahrungs- undGencssnii ttel.Zeitschrift fur offentliche Chemie.Zeitschrift fur Physik.Zcitschrift fiir physikalische Chemie, StocliiometrieZeitschrift liir deri physikalischen und ChemischenHoppe-Seyler's Zeitschrift Fur physiologische Chemie.und VerwandtschaftJehre.Un terricht

ISSN:0365-6217    

DOI:10.1039/AR92118FP001

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.A GENERAL survey of the progress made during the year 1921 showsthat whilst no new discovery of transcendent interest has beenmade, the great advances achieved in 1920 have been consolidated,and indeed in some cases have been still further extended. To thosewho keep pace with the rapid progress into virgin country by suchpioneers as Rutherford, chemistry as she is to-day must present afascination that never before was theirs. The reporter. well re-members Sir Ernest saying that the mystery of the positive atomicnucleus by common consent must be left to a future generation tosolve. By his newest work, however, he has already poached onthe preserves of posterity, since a proof of the existence of H nucleias satellites of a central nucleus would go far towards an elucidationof this mystery.Apart from its bearing on Bohr’s theory and the emission ofspectra, this work leads to the conclusion that the atomic massesof the elements are not all exact whole numbers, as Aston’s workhas suggested.I n the case of the elements with atomic massesgiven by 4N + 2 and 4N + 3, these atomic masses would be greaterthan whole numbers by 2 x 0.008 and 3 x 0.008, respectively,owing to the fact that the two or three H nuclei are satellites of theinner nucleus and do not form an integral part of a closely-packednucleus.I n view of the fact that a large number of the elements as weknow them are mixtures of two or more isotopes, it is a very re-markable fact that the experimentally determined atomic weightsshould be constant.It has even been found that the atomicweights of terrestrial nickel and of nickel found in meteorites onlydiffer by an amount that lies within the limit of experimentalerror, in spite of the fact that this element is a mixture of twoisotopes in the ratio of 2 : 1. It is necessary to believe that in thegenesis of this element, and indeed of all “ impure ” elements, theisotopes were always produced at the same time, a t the same rate,and in the same place. The genetic processes of the isotopes of anyone element must therefore have been closely connected so thatone could not occur without the other, the products always beingformed in constant ratio which probably was independent oINORGANIC CHEMISTRY. 31temperature and pressure, for it is impossible t o believe that all thenickel which has yet been experimented with was formed underidentical conditions of temperature and pressure.Apart from this work on atomic theory and structure, there ismuch of great interest to be recorded on more stereotyped lines.Indeed, it may be said that the year’s work is of great interest toall students of inorganic chemistry.Atomic Theory.Sir Ernest Rutherford has extended his investigations of theartificial disintegration of the light elements and has been able todraw certain conclusions, one of which would seem to be of verygreat importance.1 It will be remembered that when the swiftlymoving a-particles from radium-C pass through dry air or nitrogen,a few long-range particles are formed which can be detected by theirscintillations on a zinc sulphide screen.These particles are bentin a magnetic field t o about the same extent as swift H atoms of thesame range, and there is little doubt that some of the nitrogen atomsare disintegrated by the intense collisions with the a-particles andthat positively charged H ?toms are liberated a t a high speed. Nosuch long-range particles are observed in oxygen or carbon dioxide.By improvements in the observing microscope, the counting of thescintillations has been made much easier and more certain. It hasnow been found that the particles from nitrogen have a much greaterrange of penetration than the corresponding H atoms from hydrogen.For example, using radium-C as a source of x-rays with a range inair of 7 cm., no H atoms from hydrogen can be detected after passingthrough screens of aluminium or mica of stopping power equivalentt o 29 em.of air. On the other hand, the maximum range of theparticles from nitrogen corresponds with 40 cm. of air. This provesthat these particles cannot be due to the presence of free hydrogenor hydrogen compounds, and also enables other elements besidesnitrogen to be tested. If the scintillations are counted for absorp-tions greater than 29 cm. of air, the results are independent of thepresence of hydrogen as an impurity.The following table contains in the f i s t column a list of theelements examined. The second column contains the materialsactually used, the third column gives the number of scintillationsobserved per minute per milligram activity of the source a t anabsorption of 32 cm.of air, and the fourth column the maximumrange of the particles :(Sir) E. Rutherford and J. Chadwick, Phil. Mug., 1921, [vi], 42, 809;A., ii, 67132 ANNUAL REPORTS ON THE PROGRESS OF CHENISTRY.Element.LithiumGlucinumBoronCarbonNitrogenOxygenFluorineSodiumMagnesiumAluminiumSiliconPhosphorusSulphurMaterial.Li,OG10BAirCaF,Na,OAl,Al,O,SiP (red)co,0 2MgOS,SO,No. of. particlesper mm. per mg.Maximum range ofparticles in cm. of air.-ca. 4540over 40CCL. 4290ca. 66----In addition to these, the following were examined-chlorine asMgC12, potassium as KCI, calcium as CaO, titanium as Ti,O,,manganese as Mn02, iron, copper, tin, silver, and gold in the formof metal foils.In no case were any particles observed of rangegreater than 32 cm. of air.The effect of using a-particles of different velocities was in-vestigated, the different ranges being 8.6, 7.0, 6.0, and 4.9 cm.,respectively. The very interesting and important result wasobtained that with a given element the particles observcd increaserapidly in number and in velocity with the-velocity of the cc-particles.It is reasonable to expect that the great majority of particlesliberated from the various elements would be expelled in thedirection of the a-particles, but in the case of aluminium it wasfound fhat the direction of escape is to a large extent independentof the direction of the a-particles.Nearly as many are expelledin the backward as in the forward direction, but the velocity in thebackward is less than that in the forward direction.There is little doubt that the particles are in all cases P-I atoms,which are released at different maximum speeds depending on theelement and on the velocity of the incident a-particle. Of thoseso far examined, only those with atomic weights given by 4n + 2or 4n + 3, where ?a is a whole number, give rise to H atoms. Ele-ments of mass 412 like carbon, oxygen, and sulphur show no effect.This is clearly shown in the following table of elements which giveH atoms :Element. Mass. 4n + a.Boron 11 2 x 4 + 3Nitrogen 14 3 x 4 4 - 2Fluorine 19 4 x 4 + 3Sodium 23 5 x 4 + 3Aluminium 27 6 x 4 4 3Phosphorus 31 7 X 4 f 3This result receives a simple explanation on the assumption thatthe nuclei of these elements are built up of helium nuclei of masINORGANIC CHEMISTRY.334 and of hydrogen nuclei. The importance of the helium nucleusas a unit of atomic structure in the heavy elements has been estab-lished by the study of radioactive changes. In order to account forthe liberation of an H atom at high speed, it is natural to supposethat the H nuclei are satellites of the main nucleus. In a closecollision, the a-particle is able to give sufficient energy to the satelliteto cause its escape at high speed from the nucleus. The escape ofthe H atoms in all directions is readily explained on this supposition,since the directions will be determined by the angle at which theor-particles strike the orbit of the satellite. If the direction of thea-particles is tangential to the orbit, the H atom will be driven inthe forward direction of the a-particles and away from the nucleus.If the H atom is driven towards the nucleus, it will describe anorbit close to the nucleus and escape in a backward direction.Thedifference in the velocity of the H atoms in the forward and back-ward directions is probably due to the fact that the nucleus hasbeen set in motion in the direction of the a-particles before the closecollision with the H Satellite occurs. On this view, the relativevelocity of the H atom and the residual nucleus is the same whetherthe H atom escapes in the backward or forward direction, but theactual velocity in the backward direction is less.In the case of aluminium the law of conservation of energy doesnot hold unless the energy derived from the disintegration of thenucleus is taken into account.By making the three assumptionsthat the law of conservation of momentum is valid, that the resultantkinetic energy of the three bodies involved is the same whether theH atom is liberated in the forward or backward direction, and thatthe final energy of escape of the a-particle is not sensibly differentin the two cases, it is possible to calculate the final distribution ofenergy between the three bodies involved. In the case of ana-particle with range of 7 cm., it is found that the total gain of energyof the parts after a collision is 0-45 x the energy of the incidenta-particle.If the view is correct that the H nuclei are satellites of the centralnucleus, the mass of the H satellite should not be very differentfrom that of the free H nucleus, since the packing effect is absent.On the assumption that C = 12.00 and H = 1.008, the true atomicweight of nitrogen should be 12 + 2 x 1-008 = 14.016.Similarconsiderations should be applicable to the other elements fromwhich H atoms can be liberated.Reference must be made to some further work by Dr. Aston onthe mass spectra of the elements.2 The general method of the2 PhiZ. Mag., 1920, [vi], 40, 628; [vi], 42, 140, 436; A., 1920, ii, 718;REP.-VOL. Xvm. C1921, ii, 474, 565.Nature, 1921, 107, 520. T., 1921, 119, 67734 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.investigation was described in the Report for last year and it is onlynecessary to record the new results that have been obtained. Boronis a mixture of two isotopes of masses 10 and 11, the second of whichis present in greater amount. The relative amounts of the twopresent, however, do not seem to agree well with an observed ate-micweight as high as 10.9, but no evidence was found of the existenceof an isotope with mass 12. Whilst fluorine was found to be asimple element, silicon consists of two isotopes 28 and 29, but therelative amounts of these two would give an atomic weight less than28-3, and therefore in spite of the complete absence of experimentalevidence there may be a third isotope of mass 30.Bromine is an interesting case, because, instead of being almost apure element of mass 80, i t consists of an almost equal mixture oftwo isotopes with masses 79 and 81.Phosphorus and arsenic areboth simple elements, and the experimental evidence is in favour ofthis also being the case with sulphur, in spite of the fact of theaccepted value of the atomic weight.The essential condition for satisfactory measurement of the atomicmasses with the positive ray spectrograph is, of course, the existenceof stable volatile substances which may either be the elementsthemselves or their compounds with other elements of knownatomic mass. The majority of the elements do not satisfy thiscondition, and consequently, as elements less and less suitable areexamined, the work becomes more difficult and the results eitherinconclusive or entirely negative. Thus no satisfactory measure-ments have as yet been made with selenium, tellurium, antimony,and tin.Iodine, on the other hand, which was used in the form ofmethyl iodide, gave very decided evidence of being a simple elementof mass 127. As Dr. Aston says, this result is unexpected, since allkhe speculative theories of atomic evolution predict a complexiodine; thus Kohlweiler deduces five isotopes of masses 122, 124,126,128, and 130, and he also claims to have achieved a considerableseparation of these by diffusion.The earlier results obtained with xenon and chlorine have beenrevised.A purer specimen of xenon showed definite evidences offive isotopes of masses 129, 131, 132, 134, and 136, with distinctindications of a sixth component, 128, present in smaller quantity.It is possible also that there is a seventh isotope of mass 130. In thecase of chlorine, strong confirmatory evidence has been obtained ofthe definite existence of the two isotopes 35 and 37, but the questionof the third with ma68 39 still remains in doubt.It has been found possible by the use of an anode which waselectrically heated by the current from a storage battery to observethe mass spectra of the alkali metals. I n each case the anode waINORGANIC CHEMISTRY. 35coated with the salt of the metal. It was found that Lithium is amixture of two isotopes of masses 6 and 7, that sodium is a singleelement, that potassium and rubidium are mixtures of two isotopes,39, 41, and 85, 87 respectively, and that casium is a single elementof mass 133.The atomic weight of casium, 132.81, suggests thepresence of a lighter isotope, but no evidence of this could be found,and if it exists it must be in very small amount.Finally, by the use of nickel carbonyl, it has been found thatnickel consists of two isotopes of masses 58 and 60 in the proportionof 2 : 1. This gives a value for the atomic weight of 58.67, whichagrees closely with the accepted value. The whole of the observa-tions may be tabulated as follows, the doubtful isotopes beingenclosed within brackets.B?CN0FNeNaSiPS c1AKAs5678910111415161718193310.912.0014-0116.0019.0020.2023.0028.331-0432.0835.4639.8839.1074.96MinimumAtomic Atomic no.ofElement. number. weight. isotopes.H 1 1.008 1He 2 3.99 iLi 3 6.94 221111212112~~ 1Br 35 79.92 2Kr 36 82.92 5Rb 37 85-45 2I 53 126-92 1X 54 130-2 5 (7)Hg 80 200.6 (6)cs 55 132-81 1Massos of isotopesin order ofintensity.1.00847, 61 1 , l O121416192320, 22, (21)28, 29, (30)313235, 37, (39)40, (36)39, 417579, 8184, 86,82,83,80, 7585, 87127129, 132, 131, 134,136, (128), (130P)133(197-200), 202,204Mention may also be made of measurements with a heatedmagnesium anode which establish the existence of three isotopes ofmasses 24, 25, and 26, which occur in the proportion of 6 : 1 : 1 andgive an average atomic weight of 24.375.3An interesting positive result in the partial separation of theisotopes of mercury has been ann~unced.~ Two methods wereemployed, namely, evaporation and effusion.The density differ-ence between the lightest and heaviest mercury was 0.49 per cent.,a A. J. Dempster, Science, 1920, 52, 559; A., ii, 402.4 J. N. Brmsted and G. Hevesy, PhiE. Mug., 1922, [vi], 43, 31.c 36 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which corresponds with a difference of 0-1 in the atomic weight ofthe element. The results of the experiments agree with the theorythat the evaporation rate and effusion rate of the isotopes are in-versely proportional to the square root of their molecular masses.Moreover, they conform with Aston's determinations of the atomicmasses of the isotopes.Atomic Weights.Several papers have been published on the determination ofatomic weights since the writing of the last Report.Of these,the following may be referred to.A Zuminium.-Aluminium bromide was synthesised from verypure bromine and the purest obtainable aluminium.5 It wasdigested three times in nitrogen a t different temperatures, andfractionated by distillation twice in nitrogen and twice in a vacuum.The bromide was decomposed by water in such a way that the re-action occurred slowly, and the solution was precipitated by aweighed amount of pure silver. The silver bromide was collectedand weighed.From the result of four closely agreeing analyses,the atomic weight was found to be 26-963. The modern evidenceseems to show that the atomic weight of aluminium is really less,not more, than 27. The new value is distinctly nearer to a wholenumber than the old one.Antimony.-Three preparations of antimony were combined withbromine, the resulting product was twice distilled under a pressureof 6-10 mm. as long as gaseous materials could be removed, andthen distilled a third time under a pressure of less than 1 mm. intoa series of small bulbs, which were sealed off as filled. The productwas analysed for bromine in two ways ; first, by finding the amountof silver equivalent t o the sample in the usual way, secondly, byadding excess of silver nitrate, filtering, and weighing the silverbromide.Averaging the volumetric result for eleven samples withthe gravimetric results for eight samples, the most probable atomicweight for antimony becomes 121.773.Bismuth.-Bismuth triphenyl was prepared by the action of anexcess of bismuth bromide on magnesium phenyl bromide.' Theproduct was decomposed by ice-water and distilled in a current ofsteam. The bismuth triphenyl was purified by crystallisation fromabsolute alcohol, and distillation, and for the purpose of atomicweight determination was left for ten hours over phosphoric oxide5 T. W. Richards and H. Krepelka, J . Amer. Chem. SOC., 1920, 42, 2221;A., ii, 48.6 H. H. Willard and R. K. McAlpine, ibid., 1921, 43, 797; A,, ii, 406.7 A.Classen and 0. Ney, Ber., 1920, 53, [B], 2267; A,, ii, 119INORGANIC CHEMISTRY. 37in a cathode-ray vacuum before weighing. It was converted intobismuth oxide by miming weighed portions with pure oxalic acid in a,porcelain crucible, moistening with pure alcohol, heating in anelectric quartz muffle furnace, and finally ignited in a stream ofoxygen. From ten determinations, the mean atomic weight wasfound to be 208-9967.Reference was made in last year’s Report to Honigschmid’s work,and a detailed account of this work has since been published.8Two series of analyses of bismuth chloride and bismuth bromideare recorded. In each series, the atomic weight was determinedby two independent methods, gravimet’ric estimation of the ratiosBiCl, : 3AgC1 and BiBr, : SAgBr, and nephelometric measurementof the silver haloid dissolved in the mother-liquor, and determinationof the ratios BiCl, : 3Ag and BiRr, : 3Ag by gravimetric titrationwith the aid of the nephelometer.The mean value of the six mosttrustworthy series is Bi = 208.997 or in round numbers 209.00.Classen and Ney’s value has been re-calculated with the resultthat Bi = 208.91 which is 0.09 lower. Both values are decidedlyhigher than the international value.Cadmium.-The atomic weight of cadmium has been re-deter-mined by the electrolysis of anhydrous cadmium ~ulphate,~ it havingbeen found that the hydrated salt generally contains a small amountof water above that required for the composition CdS0,,8/3H20,and since such water cannot be removed, the hydrated salt is un-suitable for atomic weight determination.The weighed sulphatewas dissolved in water and electrolysed, a weighed mercury cathodebeing used. As the result of eleven analyses, the value 112.409was obtained for the atomic weight. The mean of the whole of thework of Baxter and his collaborators on the atomic weight ofcadmium is 112.411.Germanium.-The method employed was the conversion ofpotassium germanofluoride into potassium chloride by heating inhydrogen chloride.1° Very great care was taken in the purificationof the germanium compounds before the double salt was prepared.The mean of seven determinations gave Ge = 72.418.Lanthanum.-Two samples of lanthanum material were subjectedto a prolonged series of crystallisations as double ammoniumlanthanum nitrate, and the material finally obtained was shown tobe entirely free from the other rare earths by spectroscopic examina-,6 0.Honigschmid and L. Birckenbach, Ber., 1921, 54, [B], 1873; A.,ii, 646.G. P. Baxter and C. H. Wilson, J . Amer. Chenz. SOC., 1921, 43, 1230;A., ii, 640.lo J. H. Miiller, ibid., 1085; A., ii, 45638 ANNUAL REPORTS ON THE PROGRESS 03' CHEMISTRY.tion.11 From six determinations, the ratio LaC1, : 3Ag was foundto give the atomic weight of 138.914. Sevenadeterminations of theratio LaC1,: 3AgC1 gave the atomic weight as 138.912. This islower than the accepted value, 139.0, but since the presence of theusual companions of . lanthanum, cerium, praseodymium, andneodymium, would raise the apparent atomic weight, this valuemust be regarded as a maximum.Tellurium.-Pure tellurium dioxide was dissolved in pure aqueoussodium hydroxide and the tellurium estimated volumetrically eitherin alkaline or just acid solution.12 The mean of twelve estimationsin alkaline solution gave the value 127.8 for the atomic weight, andof nine estimations in acid solution the value 127.65.Thulium.-The atomic weight of thulium has been determinedfrom the ratio TmCl, : 3Ag from three specimens of thulium.13The purest fraction gave a value 169.44 for the atomic weight as amean of three determinations, whilst the other two fractions, whichcontained neoytterbium, gave 169.66 and 169.90, respectively.Zinc.-The atomic weight of zinc has been re-determined by meansof the electrolytic estimation of the amount of zinc in zinc chloride.14The carefully purified metal was converted into the bromide, andthe purified salt fused in a current of chlorine.As a mean of elevenanalyses of the chloride the value 65.372 was obtained, or, rejectingfour relatively low values, 65.379. This value is in good agreementwith recent determinations and indicates that the true atomic weightlies very close to 65.38.Nickel.-A comparison has been made of the atomic weights Qfterrestrial and meteoric nickel, the method employed being thereduction of nickelous oxide with hydrogen.l5 As a result of ninedeterminations with terrestrial material, a mean value of 58.70 wasfound, whilst three experiments with meteoric nickel gave 58.68.The difference is considered to be within the limits of experimentalerror.Catalysis.Yet another theory has been added t o the list of those whichhave been put forward to explain the rusting of iron.16 Accordingt o this theory, iron is passive towards distilled water in the absence11 G.P. Baxter, M. Tani, and H. C. Chapin, J . Amer Chem. SOC., 1921, 43,1080; A., ii, 454.12 P. Bruylants and G. Desmet, Bull. SOC. chirn. Belg., 1914, 28, 264;A., ii, 448.13 C. James and 0. J. Stewart, J. Amer. Chem. SOC., 1920, 42, 2022; A.,1920, ii, 759.14 G. P. Baxter and J. H. Hodges, ibid., 1921, 43, 1242; A., ii, 639.l5 G. P. Baxter and L. W. Parsons, ibid., 507; A., ii, 338.l8 J. A. N. Friend, T., 1921, 119, 932INORGANIC CHEMISTRY. 39of a, catalyst and passes into solution, but only with extreme slow-ness, owing to the traces of electrolytes that are present.The ironpasses into solution as ferrous ions, but is rapidly converted intothe sol of ferrous hydroxide. This sol is oxidised by the dissolvedoxygen to the sol of a higher hydroxide, which now acts catalytically,by oxidising metallic iron with relatively great rapidity and simul-taneously being reduced to the lower hydroxide, only to be oxidisedagain by the dissolved oxygen. I n other words, the sol acts as anoxygen carrier.A number of experimental results are given in support of thistheory. In the first place, if pure metallic iron is suspended in astream of water, the amount of corrosion increases to a maximum asthe velocity of the stream is increased.With further increase inthe velocity of the water, the amount of corrosion decreases to aminimum. There was, however, a distinct loss in weight of the ironeven when the velocity was 30,000 feet an hour, but this is attributedto mechanical erosion. Somewhat analogous observations weremade of the potential difference between iron and platinum wiresimmersed in dilute solutions of electrolytes at rest and in motion.Slight movement increases the potential difference, but a maximumis soon attained, after which an increase in velocity causes thepotential difference to fall to a constant value. These resultsare interpreted t o mean that the rapidly moving water sweeps awaythe colloid from the surface of the iron.If the suggested theory is correct, then the inhibiting effect ofdissolved salts on the corrosion of iron should be proportional tothe coagulating power of the salts on hydrosols.Some measure-ments of the effect of solutions of certain salts on corrosion showdecreases which are comparable with their precipitating powerstowards colloidal ferric hydroxide. Confirmatory evidence is alsofound in the inhibiting action on the corrosion of protective colloids,of colloid poisons, and of the p- and 7-rays from radium.It is further suggested that this theory is of more general applica-tion, since many reactions which have hitherto been ascribed toions may possibly be explained more readily on the autocolloid,catalytic theory.Many so-called catalysts, which are known to bechemically inert, may act by rendering possible the existence of acolloid catalyst formed from the reacting substances themselves.They are not, therefore, true catalysts in the sense of actually takingpart in the reactions themselves, but may be termed secondarycatalysts. For instance, the addition of dry benzene causes instantcombination between perfectly pure and dry ammonia and hydrogenchloride. It is quite in accord with the behaviour of benzene,however, to suppose that it facilitates the formation and stabilisatio40 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of a colloidal form of ammonium chloride, which catalytically assiststhe union of the remaining ammonia and hydrogen chloride.Whilst not necessarily denying the correctness of Dr.Friend’stheory of the corrosion of iron, the reporter feels that his proposedapplication to such cases as ammonia and hydrogen chloride is opento criticism, mainly for the reason that it offers no explanation.The statement that the known catalytic effect of benzene on amixture of ammonia and hydrogen chloride is due to the fact that itforms another catalyst does not advance our knowledge. Theessential underlying factor in all reaction is energy, and the r6leof the catalyst is to supply the necessary energy to the catalyte.Every reaction consists of three stages, and the first of these is theconversion of the reactant molecules from their normal and non-reactive phase into the reactive phase, a change which requires thesupply of energy to the molecules.The second stage is the re-arrangement of the atoms whereby new compounds are produced,and it is this stage, and this stage only, which is expressed by thechemical change of the reaction. The third stage is the conversionof the newly synthesised molecules into their normal and non-reactive phase. The second and third stages are accompanied byan evolution of energy, and the observed heat of the reaction is thedifference between the sum of the two amounts of energy evolvedin the second and third stages and that absorbed in the firststage.The energy necessary for the first stage may be gained by ex-posing the reactant molecules to heat or light, when the reaction iscalled thermal or photochemical.The necessary increment ofenergy may also be supplied by a material catalyst, the wordcatalyst being used in the broadest sense. In whatever way thecatalyst behaves, the fact remains that it functions as a supplier ofenergy to the reactant molecules, whereby they are converted fromthe non-reactive to the reactive phase.It is true that many reactions may be said to proceed without theaddition of a specific catalyst, but this is simply due to the factthat the reactant molecules have already been brought into theirreactive phases by the use of a solvent, the solvent, of course, beingthe catalyst. Then, again, there is the phenomenon of autocatalysis,when the velocity of a reaction, at first small, increases up to amaximum.When the second and third phases of the reaction aretaking place, energy is radiated, and this energy can be re-absorbedby the surrounding reactant molecules, with the result that more ofthese are activated and the velocity increases to a maximum definedby the amount of the radiated energy that is re-absorbed. This hasbeen proved to take place in the case of the photochemical union oINORGANIC CHEMISTRY. 41hydrogen and chlorine, and in the photosynthesis of formaldehydeand sugars from carbon dioxide and water.To take the case quoted of ammonia and hydrogen chloride,these gases, when pure and dry, exist in their non-reactive phases,and the catalyst, whether it be water vapour or benzene, suppliesenergy to the molecules so that they are converted into their re-active phases, which instantly combine to form ammonium chloride.The statement that one catalyst acts by producing another is oflittle use, for, if explanation is sought of the rise in velocity observedafter the reaction has commenced, it is to be found in the re-absorp-tion by the reactant molecules of the energy radiated in the reactionbetween a few of these.It may be noted that the very interesting observation made bySugden can be explained very readily on this theory.1' The activityof nascent hydrogen is by no means necessarily due to its dissocia-tion into free atoms.The normal, non-reactive hydrogen moleculecan be rendered active for certain reactions by an amount of energywhich is smaller than that required to dissociate it into atoms.This is exemplified by the activation of a portion of the hydrogenwhen three volumes of this gas are exploded with one volume ofoxygen.18 The residual gas reduces alkaline potassium perman-ganate to manganate, indigotin in alkaline solution t o indigo-white,ferric chloride to ferrous chloride, potassium nitrate to potassiumnitrite, arsenious acid to arsine, potassium perchlorate to potassiumchloride, etc.A similar explanation is applicable to the activeform of hypophosphorous acid.19In their important paper on the catalytic oxidation of ferroussalts, Thomas and Williams 20 recognise that neither intermediatecompound formation nor adsorption alone is capable of explainingcatalysis. The key to the problem is the transference of energyto the catalyte by way of the intermediate compound or of adsorp-tion. Again, in the cases of heterogeneous catalysis by metals, itfollows from this theory that the activation by the catalyst cannotextend to more than a molecular layer of the catalyte.The ex-perimental evidence supports this conclusion very strongly, and theparticular case of palladium is dealt with under Group VIII.In conclusion, two questions may be asked as regards Dr.Friend's theory of the corrosion of iron, which in spite of their veryobvious nature do not seem to have been dealt with in his paper.The first of these is, Why is rust formed and not a solution of ferricl7 S. Sugdon, T., 1921, 119, 233.l8 Y. Venketramaiah, Nature, 1920, 106, 46.2o R.Thomas and E. T. Williams, ibid., 749.A. D. Mitchell, T,, 1921, 119, 1266.C42 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hydroxide sol ?rapidity in a solution of ferric hydroxide sol 1The second question is, Does iron rust with greaterGroup I .The properties of pure hydrogen peroxide have been investigatedand a method given for its preparation.21 Three per cent. hydrogenperoxide, obtained from barium peroxide, is concentrated to 30 percent. by means of a sulphuric acid concentrator.22 It is then dis-tilled at very low pressure to remove the non-volatile impurities.A further concentration by the sulphuric acid concentrator at 0"raises the concentration to 90 per cent., and the final product,100 per cent.hydrogen peroxide, is obtained by fractional solidi-fication and melting. The pure substance is found to have thefollowing physical properties : m. p. -1*70", density of liquid a t-0.53" 1.4638, association factor 3.48, specific heat between 0"and 18.5" 0.5730, latent heat of fusion 73.91 cal. Hydrogen per-oxide is very slightly soluble in ether, it dissolves many normalsalts, and it attacks glass. Freezing-point determinations ofsolutions of hydrogen peroxide in water show that only one com-pound, H,0,,2H20, exists with melting point -51".23Some work has been done on the hydrides of the alkali metals.In the case of lithium hydride, it would seem that the substancepossesses the properties of a salt.24 Electrolysis of the compoundgives lithium at the cathode and, apparently, hydrogen a t theanode, this being the first observed instance of hydrogen functioningas a negatively charged ion.The following constants were deter-mined : density 0.816, molecular volume 9.77, heat of formation21,600 & 250 cal., Li + H20 = LiOH + H + 52,723 & 200 cal.,LiH + H,O = LiOH + H, + 31,110 & 50 cal.Pure sodium hydride can best be prepared by leading a rapidstream of hydrogen directly on to the surface of the metal at such atemperature that a yellow glow is produced.25 The temperaturemust be above 350", when the sodium hydride is carried away as awhite smoke, which is precipitated electrically and filtered throughglass wool. Potassium hydride can be obtained by leading the gasinto the metal at 350".The reaction in each case is facilitated bythe presence of metallic calcium.Rubidium and caesium hydrides were prepared by heating a21 0. Maass and W. H. Hatcher, J . Amer. Chem. SOC., 1920, 42, 2548;22 0. Maass, ibid., 2571; A., ii, 104.28 0. Maass and 0. W. Herzberg, ibid., 2569; A., ii, 106.24 K. Moers, 2. anorg. Chem., 1920, 113, 179; A., ii, 200.2s F. Ephraim and E. Michel, Helv. Chim. Acta, 1921, 4, 762; A . , 2, 638.A,, ii, 106INORGANIC CHEMISTRY. 43mixture of their carbonates with metallic magnesium in hydrogena t 650" for five days and a t 580-620" for three days, respectively.The stability of these hydrides decreases from sodium to czesium.Some doubt has been thrown on the correctness of the formulaNaB0,,4H20 for sodium perborate, it being stated that the com-position is more correctly represented by NaB02,H202,3H20.26The salt, after partial dehydration at 50-55", loses more water a t120" in a vacuum and the residue consists chiefly of (NaBO,),O,.This substance loses oxygen on treatment with water and hasproperties which differ from those of NaBO,, and it is concludedthat a substitution product of H,O, exists with constitutionThree crystalline hydrates of disodium hydrogen phosphateare known with 12H20, 7H,Q, and 2H20, respectively.Thedihydrate can readily be prepared by boiling the finely-powdereddodecahydrate with ethyl alcohol, whilst the heptahydrate can beobtained by fusing the appropriate mixture of the dodecahydrateand dihydrate and cooling.27 The following transition temperatureshave been determined : Na,HP04,2H20 - Na2HP04, 94.97" ;Na2HP0,,7H2O - Na,HP0,,2H20, 48.09" ; Na2HP04, 12H,O -Na,HP0,,7H20, 35.0".In addition to this, sharp breaks wereobserved in the heating and cooling curves for the dodecahydrateat 29.6", due to a change of phase in this substance. Two forms ofNa2HP0,,12H20 exist, of which one is stable between 29.6" and35.0" and the other is stable below 29%". The existence of thesetwo forms has been confirmed by solubility measurements.It has been recorded that by the action of dry nitrogen peroxideon pure copper powder the compound Cu2N02 is produced. Somefurther work has now been carried out on this reaction, as the resultof which it has been proved that this compound does not exist.28The copper powder was prepared by reduction of copper oxide withhydrogen and by reduction of hydrated cuprous oxide with carbonmonoxide.The cuprous oxide was obtained by pouring a solutionof pure cuprous chloride in dilute hydrochloric acid into a dilutesolution of sodium hydroxide. The product, after being dried overphosphoric oxide in a vacuum, was found to be 4Cu20,H20.When the copper powder was allowed t o remain in contact withnitrogen peroxide, absorption took place, but no stoicheiometricrelation could be foand between the weight of the copper and the26 F. Foerster, 2. angew. Chem., 1921, 34, 354; A., ii, 506.e7 D. L. Hammick, A. K. Goadby, and H. Booth, Ip., 1921,119, 1589.28 H. V. Tartar and W. L.Semon, J . Amer. Chem. SOC., 1921, 43, 494;A., ii, 336c* 44 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.increase in weight. Analysis of the product showed that the atomicratio of nitrogen to oxygen was 1 : 3. Moreover, the product losesweight on being exposed to air due to the evolution of nitric oxideor nitrogen peroxide. When the product is treated with water,90 per cent. of the nitrogen is found in the form of nitrate and 10 percent. as nitrite. It is suggested that the reaction consists in theformation of anhydrous cuprous nitrate on the surface of the copper.Group I I .A description has been given of the preparation of the yellowhigher oxides of calcium and barium, and it is believed that theseare the tetroxides.29 The calcium compound may be prepared bygently warming calcium peroxide octahydrate with five to six timesits weight of pure hydrogen peroxide (30 per cent.) until a vigorousevolution of oxygen occurs.The mixture is allowed to cool untilthe evolution of gas subsides, and the warming and cooling arerepeated until practically no more gas is evolved. The precipitateis washed successively with water, alcohol, and ether, and dried.The product has a bright yellow colour and can be heated a t 130"without change. It dissolves in acid with a brisk evolution ofoxygen mixed with a small a,mount of carbon dioxide and with theformation of hydrogen peroxide. The evolved oxygen is inactive,since bromine is not liberated when the evolution takes place in anacidified solution of potassium bromide. The only known types ofsubstance which evolve inactive oxygen are the oxyhydroxides, forexample, (KOH),O,, and the tetroxides, for example, K,O,. Thestability of the calcium oxide towards heat excludes the fist, SOthat in all probability it is calcium tetroxide, CaO,.As judged bythe amount of oxygen evolved, this substance is present to theextent of 8.7 per cent.Barium tetroxide is much less stable than the calcium compound.The substance BaO,,H,O, can only be preserved for a short time a ttemperatures below 0". At the atmospheric temperature, itrapidly becomes yellow owing to the formation of the tetroxide, andthe colour increases in intensity during twenty-four to thirty-sixhours, after which it disappears almost completely within four orfive days, the complete reaction being 2BaO,,H,O, = 2BaO,,H,O +0,.If the highly coloured preparations are dissolved in acid,inactive oxygen is evolved corresponding in amount with about8 per cent. of barium tetroxide in the best preparations. It wasfound impossible to prepare purer specimens of the tetroxides owingto the readiness with which the products decomposed in the presenceof water.29 W. Trsube and W. Schulze, Ber., 1021,54, [B], 1626; A., ii; 648INORGANIC CmMISTRY. 45Some work has been carried out on the crystallisation of calciumand magnesium carbonates with the view of explaining the naturalformation of these salts and of dolomite.30 In the presence ofmagnesium sulphate, calcium carbonate crystallises a t 20" from watersaturated with carbon dioxide only in the form of aragonite ; 0.9 percent.of magnesium sulphate is sufficient to inhibit the appearance ofcalcite. It was stated by Vaubel 31 that aragonite and calcite differin that the former contains traces of a basic carbonate, but this hasnow been shown experimentally to be incorrect.Saturated solutions of magnesium hydrogen carbonate deposit bc-tween 65" and the boiling point a basic carbonate, 4Mg0,3C0,,6H20,in the form of slender needles. Between 65" and 55", the basiccarbonate separates, mixed with the trihydrate, MgC03,3H,0 ;below 55", the trihydrate alone is formed down ho about 6", and at2" the unstable pentahydrate is f0rmed.~2 All attempts to crystallisemagnesite fail, and it is concluded that this mineralis of marine origin.Numerous attempts were made to obtain synthetic dolomite bycrystallisation of calcium and magnesium carbonates under differentconditions, but without success.It is suggested that mixtures ofthe composition of dolomite are formed from sea-water, the mechan-ism of the recrystallisation as dolomite being unknown.Various methods for the purification of mercury which has becomecontaminated with other metals by use in the laboratory have beensuggested from time to time. It has been shown that distillationalone is not effective, and the treatment with nitric acid or mercurousnitrate solution is often of very little use. It is now claimed 33 thatthe most efficient method is to heat the metal a t 150" in a flaskwhile passing a current of air through it by means of a glass tubeextending about 1 cm.below the surface. After several hours, themetal is filtered from the scum and again treated by the samemethod. The process is repeated until no further scum forms, afterwhich the filtered metal is distilled in a vacuum from an ordinaryfractionating flask.The purification of impure mercury by treatment with air is notin any way new, and the novelty consists in the heating a t 150".It may be pointed out that a very essential necessity in all methodsinvolving the treatment with air is the complete absence of dust.Two methods have been described for the preparation of mercuricazide in a form which is less sensitive than the ordinary form.3430 H.Leitmeier, Jahrb. Min., 1816, Beil. Bd., 40, 655; A., ii, 112.31 J . pr. Chem., 1912, [ii], 86, 366; A., 1912, ii, 1180.32 H. Leitmeier, 2. Kryst. Min., 1909, 47, 104; A., 1910, ii, 49.33 C. Harries, 2. angew. Chem., 1921, 34, 359; A., ii, 552.34 A, Stettbacher, 2. ges. Schiess-u. Sprengstoflu,., 1920, 15, 211; A., ii, 4846 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It appears that the sensitivity is greatly dependent on the crystallineform. Thus, by mixing concentrated solutions of sodium azidea,nd mercuric nitrate, mercuric azide is precipitated as a powderymass. The salt as thus prepared is even less sensitive than leadazide, but it is converted into the highly sensitive form by re-crystallisation.Crystalline compounds of mercurous oxide with ammonia andsulphur dioxide have been prepared by the action of sulphur dioxideon the precipitate obtained from mercuric chloride and excess ofammonia.35 The precipitate dissolves and the compounds separatewhen the solutions are evaporated under reduced pressure.Ifsulphur dioxide is first added and then ammonia, the compoundsHg(SO,*NH,), and HgCl(SO,*NH,) are produced. Excess ofammonia gives the compounds Hg*SO,*NH, and Hg(SO,*NH,)OH.In the presence of large amounts of ammonium chloride the com-pound NH,C1*Hg*S0,*NH4 is formed, which is converted bypotassium hydroxide into Hg,O, S 0, ,NH,.Group I I 1 .Boron nitride has been prepared in quantity by leading a mixtureof boron trichloride vapour and ammonia through an intenselyheated tube.36 Difficulty was caused by the voluminous nature ofthe nitride, but this was overcome by the use of a quartz tube whichwas electrically heated in zones.The yield was 80-85 per cent.,and the nitride was obtained as a colourless powder, the reactivityof which depends on the temperature a t which the reaction iscarried out. At SOO", a very voluminous product is obtained which,after exposure to the atmosphere, gives some ammonia. Theproduct obtained a t much higher temperatures is more stable inair.A convenient method has been given for the preparation ofcalcium arsenide which can be employed for the formation ofhydrogen arsenide.37 A neutral diluent such as sand or calciumarsenide from a previous preparation is added to the extent of50 per cent.by weight to a mixture of powdered arsenic and calciumfilings. The whole is placed inside a sheet-iron container enclosedwithin a second vessel. The reaction is started by means of amagnesium-potassium chlorate mixture and steadily proceedsOhroughout the entire mass. There is no flame and very littlearsenious oxide is formed.The resulting calcium arsenide, on treatment with water or acids,3 5 0. Ruff and E. Krohnert, 2. anorg. Chern., 1920,114, 203; A., ii, 202.a6 F. Meyer and R. Zappner, Ber., 1921, 54, [B], 560; A., ii, 329.3 7 H. Thorns and L. HBSS, Ber. Deut. Pharm. Get?., 1920,30,483; A , , 6,110INORGANIC CHEMISTRY. 47gives hydrogen arsenide containing 14 per cent. by volume ofhydrogen. Aqueous solutions of t,he gas undergo rapid decomposi-tion with formation of colloidal arsenic, and the reaction may befollowed by titration with N/lOO-iodine solution.At first, thehydride is oxidised according to the equation ASH, + 31, + 3H,O =H3As0, + 6HI. After rendering the solution alkaline by theaddition of potassium hydrogen carbonate, the normal oxidationto arsenic acid takes place.An acid fluoride of thallium, H,TlF,, is obtained by dissolutionof thallium in hot dilute hydrogen fluoride and evaporation of thesolution to dryness.38 The salt loses hydrogen fluoride on beingheated and forms with water acid solutions, which, however, donot attack glass. The neutralisation curve shows that two typesof complex salts exist, for example, KHTlF, and K,TlF,.Group I V .An important paper has appeared on the preparation of thetrithiocarbonates and perthiocarbonates of the alkali and alkalineearth The general method of preparation was the additionof the requisite amount of carbon disulphide to alcoholic solutionsof either the hydrosulphides or the disulphides of the metals.These solutions were obtained by the method described by Ruleand Thomas. After the carbon disulphide had been added, thethiocarbonates separated after dilution with ether.The operationswere carried out in an atmosphere of hydrogen, since the saltsreadily decompose in the presence of moist air or carbon dioxide.Sodium trithiocarbonate, Na,CS,,H,O, forms very deliquescentneedles with a pinkish-yellow colour. They give a distinctly redsolution in water, which is stable if oxygen and carbon dioxide arerigidly excluded.The perthiocarbonate, Na,,CS4,3H,0, separatesas brownish-yellow needles and is very deliquescent. It readilydissolves in water to a distinctly yellow solution. The heats offormation of sodium trithiocarbonate and sodium perthiocarbonatein alcoholic solution were found to be 5700 and 8550 cals.,respectively.The following salts were also prepared, K,CS, ; 2K,CS4,H,0 ;3Ca(OH)2,CaCS,,9H,0 ; Ca( OH),,CaCS3,2H,O ;2Ca(OH),,CaCS4,8H,0 ; SrCS3,4H,0 ; SrCS4,8H,0 ; BaCS, ;Reference may be made to some further work on the hydrides ofsilicon and their derivative^.^^ Attempts were made to synthesise(NH4)ZCS3 ; (NH4)ZCS4 ; (NH4)2CS4,H20*s8 Barlot, Compt. rend., 1920, 171, 1143; A., ii, 113.39 E.W. Yeoman, T., 1921, 119, 38.40 A. Stock and K. Somieski, Ber., 1921, 54, [B], 524; A., ii, 33048 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.disilane by the act,ion of the alkali metals on monochlorosilane,but the results obtained were unexpected.Monochlorosilane reacts readily wit'h potassium a t the ordinarytemperature, but the metal becomes coated with a protective layerwhich speedily inhibit's the reaction. At 300°, the reaction is com-plete, the products being silicon, potassium hydride, potassiumchloride, and hydrogen. When allowed to remain in contact withpotassium-sodium alloy for a month, monochlorosilane gave anincomplete reaction. The chief volatile product was monosilane,whilst disilane could only have been present in traces. Whensodium amalgam was used, the chief product again was monosilanemixed with a small amount of hydrogen, but in this case the presenceof disilane in small quantity was definitely established.Disilaneundergoes slow decomposition in the presence of sodium-potassiumalloy or of sodium amalgam to give hydrogen and monosilane. Itmay be noted that methyl chloride behaves similarly to mono-chlorosilane towards sodium amalgam, since it gives methane andethane. Dichloromonosilane is converted by sodium amalgam intomonosilane and hydrogen.Chlorosilane and ammonia 41 react a t the ordinary temperaturequantitatively to give ammonium chloride and trimonosilylamine,N(SiH,),. The latter is a spontaneously inflammable liquid withm.p. -105*6", b. p. 52", and density 0.895. It is stable in theabsence of air and is vigorously decomposed by water accordingto the equation N(SiH,), + 6H20 = 3Si0, + NH, + 9H2. Thevapour density corresponds with the simple formula, N(SiH,),, andthe substance does not combine with hydrogen chloride or mono-chlorosilane.By the action of an excess of ammonia on monochlorosilane, theinitial product obtained is chiefly dimonosilylamine, NH( SiH,),,which is probably mixed with the corresponding tri- and mono-amines. The diamine is only comparatively stiable and de-composes gradually according to the equation NH(SiH,), =SiH, + SiH,:NH. The last compound cannot exist in the uni-molecular form and condenses rapidly to the solid polymeride,(SiH,:NH),.A second reaction also takes place to a smaller extentwith evolution of ammonia, SiH,*NH2 + NH(SiH,), N(SiH,),,with the result that the composition of the final residue correspondswith that of a mixture of (SiH,:NH), and N(SiH,),.Between dichlorosilane and excess of ammonia the followingreaction takes place a t the ordinary temperature, SiH,CI, +3NH3 = 2NH4C1 + SiH2:NH.The polymeride, (SiH,:NH),, is a white substance resembling4 1 A. Stock and K. Somieski, Ber., 1921, 54, [B], 740; A., ii, 399INORGANIC CHEMISTRY. 49silicic acid, and the value of x is certainly very high, since when thecompound is produced in benzene solution, x = 7-8. When thebenzene solution is evaporated, a visoous liquid is obtained whichonly slowly passes into the solid and more highly polymerisedcondit>ions.The behaviour of the silylamines when treated with hydrogenchloride is very remarkable, because they are smoothly and quanti-tatively transformed into monochlorosilane and ammonium chloride.When calcium silicide was carefully treated with cold dilutealcoholic hydrochloric acid in the dark, a white, solid substance wasobtained together with a certain amount of hydrogen.42 The whitesubst>ance has the constitution Si,H*OH, and to it has been giventhe name of oxydisilin.It is a powerful reducing agent and isconverted by means of bromine to silical bromide, Si,OHBr.This substance is hydrolysed by water to silical hydroxide, a redcompound which combines with strong acids to form salts that areyellow to red in colour.The silical compounds are all powerfulreducing agents and they are decomposed by alkalis to form silicawith evolution of hydrogen.It has generally been believed that the coloured compoundsobtained by the action of hydrogen peroxide on titanic salts arederivatives of the oxide, TiO,. From estimations of the activeoxygen it appears that these compounds are really complexes ofhydrogen peroxide and pcrtitanic salts derived from the peroxide,Ti,0,.43 The complex double potassium salt, K,S04,TiOS04, wasprepared, and when the salt was dissolved in ice-cold water andalcohol added, the clear liquid decanted from the precipitate wasfound to contain hydrogen peroxide. The addition of alcohol to asolution prepared by pouring equimolecular quantities of potassiumsulphate and titanyl sulphate into an excess of hydrogen peroxidegave a precipitate of the hydrated peroxide, Ti,O,,xH,O.Some doubt has been thrown on the usually accepted explanationof the existence of the various forms of lead monoxide. Thisexplanation is due to R ~ e r , ~ ~ who stated that the forms are different,allotropic modifications.It is now suggested that there is a muchcloser relationship between the forms, and, indeed, that the differencebetween them is due to variations in the size of the particles.45 Thered form of the oxide consists of particles, 3p to 5p, which, on beingheated at 700" and then cooled,*giye yellow agglomerates, lop to2Op. These easily break down un&r pressure to particles smaller42 H.Kautsky, 2. anorg. Chem., 1921, 117, 209; A., ii, 505.43 M. Billy, Compt. rend., 1921, 172, 1411; A., ii, 456.44 It. Ruer, 2. anorg. Chem., 1906, 50, 265; A., 1906, ii, 755.-45 S. Glssstone, T., 1921, 119, 168950 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.than those of the original red form, 0 . 7 ~ to 1.5p. The reddish-brown preparations consist of particles of the same order of magni-tude as the finer particles of the yellow forms. All the forms givea brown powder on being ground in a mortar, the particles of whichare uniformly 0 . 7 ~ in diameter.It is to be expected therefore that differences in solubility shouldbe found depending on the size of the particles. The red formshould have the lowest solubility and the reddish-brown formsshould give higher values.This was proved to be the case bydetermination of the solubility of the various forms in a N-solutionof sodium hydroxide free from carbonate.The author makes no reference to the fact that the yellow form oflead monoxide is converted into the red form on exposure to light.This would lead to the conclusion that the difference is not onlyconcerned with the size of the particles, but that there is a differenceof energy content, a t any rate between the yellow and red forms.Group V .Anhydrous ammonia and anhydrous chlorine react together toform nitrogen chloride and ammonium chloride, and the quantitiesthat react do not change even when the relative proportions of thetwo reactants are varied between wide limits.46 There is little orno reaction between chlorine and the solid ammonium chloridewhich is formed.A considerable proportion of the nitrogenchloride a t first formed decomposes into nitrogen and chlorine,either directly or by interaction with ammonia.Nitrogen chloride is quantitatively converted by dry hydrogenchloride into ammonium chloride, the action taking place in thepresence or absence of an inactive solvent.47 The reaction, there-fore, is not one of hydrolysis and probably consists in the initialformation of trichloro-ammonium chloride, NCl,HCl, which losesone positive atom and one negative atom of chlorine, the additionof hydrogen chloride and loss of chlorine taking place three times insuccession. The formation of nitrogen chloride by the action ofchlorine on an ammonium salt would seem to be the reverse of thisreaction.For the preparation of nitrogen chloride ammoniumsulphate is more suitable than ammonium chloride. Hypochlorousacid is preferable to free chlorine, because the use of the latter leadsto the formation of some chloroamine and dichloroamine along withthe nitrogen chloride.Attempts were made to cause direct combination between46 W. A. Noyes and A. B. Haw, J . Amer. Chem. Soc., 1920, 42, 2167;4 7 W. A. Noyes, ibid., 2173; A., ii, 42; i b k i . , 1921, 43, 1774.A., ii, 42INORGANIC CHEMISTRY. 51nitrogen and chlorine by passing a mixture of the two gases throughthe flaming arc and also through an efficient ozoniser. Nomeasurable combination took place, nor was there any reactionwhen active nitrogen was passed over chlorine at -190".An investigation has been made of the conditions under whichthe various compounds of ammonia and carbonic acid may beprepared from solutions of these two component^.^^ Five com-pounds were obtained, and of these only one, NH4*HC0,, forms atrue equilibrium in which the ratio between CO, and NH, is thesame in the solution and in the solid phase.It was found that thedouble salt, 2NH,*KCO,, (NH,),CO,,H,O, crystallises from solutionscontaining NH, and CO, in the ratio 4 : 5. Normal ammoniumcarbonate may be prepared by adding 395 grams of ammoniumhydrogen carbonate to 150 grams of water and 333 grams of ammoniasolution (25 per cent.) and passing in ammonia under an increasedpressure of 0-2 atm.The mixture is warmed at 40" until solutionis complete, when, on cooling t o lo", the normal salt separates.Solutions were prepared by dissolving each of the above salts andammonium carbamate in aqueous ammonia of different concentra-tions, and these solutions were cooled t o the temperature required.The range of temperature was from 0" t o 60", and the followingsolid phases were identified between 0" and 33"-NH4*HCO, ;2NH4*HCO3,(NH4),CO,,H2O ; (NH,),CO, ; NH4*HC0,,NH,*C0,*NH, ;NH,*CO,*NH,. Of these, the normal carbonate and the two doublesalts have a limited temperature range of stability. Between 33"and GO", no further change was observed.A convenient method for the storage of ammonia has beendescribed49 which is based on the fact that a t 0" ammonium thio-cyanate absorbs ammonia up to 45 per cent.of its weight. A wide-necked bottle about 5.00 C.C. in capacity is fitted with a stoppercarrying an inlet and outlet tube, each of which is provided with astop-cock. The bottle is filled with the dry salt and is surroundedby ice, and the inlet tube connected with an ammonia generator,when the gas is very rapidly absorbed. After the salt has becomesaturated, the stop-cocks are closed and the bottle is placed inwater and maintained at the ordinary temperature or a little above.The dry gas may then be drawn off as required. It is advisablet o recharge the apparatus before the salt commences to crystallisefrom the liquid in order to guard against the blocking of the inlettube.4 s E.Terres and H. Weiser, 2. Elektrochem., 1921, 27, 177; d.,40 H. W. Foote and S. R. BrinkIey, J . Amer. Chem. SOC., 1921, 43, 1178;ii, 448.A., ii, 44852 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.By the addition of a solution of antimony trioxide in hydrochloricacid to a solutlion of sodium thiosulphate and the chloride of analkali or alkaline-earth metal a t about 3", the stibio-thiosulphatesare formed.50 The salts may be crystallised a t low temperaturesor precipitated by the addition of alcohol. The reaction proceedsaccording to the equation SbOCl + 2HC1+ 3KzS203 = 3KC1 +H20 + K,Sb(S,O,),, and the constitution of the salt is representedby Sb(S*SO,*OK),. The sodium salt is extremely soluble and hasnot been prepared in the solid state.The potassium salt formssilk-like, needle-shaped crystals, very similar in appearance toasbestos. The barium salt is white and not very stable. Itquickly becomes yellow and finally very deep yellow in colour,owing to decomposition. The potassium salt, on heating, decorn-poses according to the equation 21~,Sb(S20,), = Sb,S3 + 3K2S0, +3s02 + 3s. The aqueous solution, when boiled, decomposes withdeposition of the orange-red compound, Sb,OS,.The corresponding potassium arseno-thiosulphate,5l K,As(S,O,),,has been prepared in an exactly analogous manner. It is a whitesubstance which is not very stable when moist. Its aqueoussolution, on boiling, decomposes to give potassium trithionateaccording to the equation(KO*SO,*S),As + As(S*SO,*OK), = As2S3 + 3KO*S0,*S*S02*OK,and from this it would seem that trithionic acid has the persulphideformula.Group V I .It is known that by the action of ozone on sodium hydroxide andpotassium hydroxide orange-coloured products are obtained whichare believed to be ozonides or higher oxides.52 Attempts have beenmade to prepare these substances by the action of ozone on solutionsof the alkali and alkaline-earth metals in liquid amrn0nia.5~ Althoughthe compounds were precipitated, difficulties were caused by theaction of ozone on ammonia.The ozonides, therefore, could not beobtained in a pure state. They are readily decomposed by waterand dilute acids with evolution of oxygen and formation of hydrogenperoxide.The ozonides of rubidium and czesium are more stablethan the sodium, potassium, calcium, and barium compounds.It was found that ozone is quantitatively reduced by liquidammonia, the products being about 98 per cent. of ammoniumnitrate and 2 per cent. of nitrite. The first action of the ozone is to60 J. v, Sziltigyi, 2. anorg. Chem., 1920, 113, 69; A., ii, 207.61 Idem, ibid., 75; A., ii, 199.52 W. Traube, Ber., 1912, 45, 2201; A., 1912, ii, 844.53 W. Strecker and H. Thienemann, ibid., 1920, 53, [B], 2096; A., ii, 44INORGANIC CHEMISTRY. 53produce an orange colour, which may be due to an unstable ozonide.Ozone also reacts with methylamine, dimethylamine, and trimethyl-amine. I n the last case, the reaction is explosive, even a t -60".A 5-10 per cent.solution of trimethylamine in chloroform giveson treatment with ozone trimethylamine oxide, O:N(CH,),, whichis precipitated as the hydrochloride, the hydrogen chloride beingformed by the action of ozone on chloroform.Very stable colloidal solutions of selenium 54 may be prepared bythe regulated action of concentrated hydrazine hydrate solution onselenium dioxide or grey, crystalline selenium, and subsequentdilution of the solutions with water and purification by dialysis.These solutions vary in colour from intense yellow t o blood-red,and when dilute are stable at the boiling point.When selenium sols produced by the action of sulphur dioxide onsolutions of selenious acid at 60" are frozen, the destruction causedby the freezing is greater the more completely the solutions have beenpurified by dialy~is.~5 Even although the solutions are completelyfrozen, the greater part of the colloid goes back into solution aftermelting.If the freezing is repeated many times, or if the solutionis kept in the frozen condition too long, the colour by transmittedlight becomes less intense and the stability of the sol becomes muchless, particularly towards an increase in temperature. The natureof the reducing agent employed in the preparation of the sols andthe temperature of preparation have a great influence on thestability toward freezing. Sols prepared by reduction with hydr-azine at 60" and dialysed are much more sensitive to freezing thanthose prepared by reduction with sulphur dioxide at the ordinarytemperature.The hydrazine sols coagulated irreversibly on coolingeven before solidification occurred. I n the case of the sulphurdioxide sols, the concentration of the undialysed sol has a markedinfluence on the stability towards a reduction of temperatme.The more concentrated sols are more readily destroyed by freezingthan the more dilute solutions.Three methods have been given for the preparation of seleniumoxychloride. 56 Selenium in solution in carbon tetrachloride istreated with chlorine. Selenium monochloride is first formed andremains dissolved in the carbon tetrachloride. If any metallicimpurities in the selenium are present, these are precipitated aschlorides and may be separated by filtration a t this stage.Thesolution is then saturated with chlorine and selenium tet'rachlorideis precipitated. The calculated quantity of selenium dioxide is63 A. Gutbier and R. Emslander, Ber., 1921, 54, [B], 1974; A., ii, 636.65 A. Gutbier and F. Flury, KoEloid Z., 1921,29, 161 ; A., ii, 693.6* V. Lenher, J . Amer. Chem. SOC., 1920, 42, 2498; A., ii, 10954 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.added, when selenium oxychloride is formed and the whole passesinto solution. The selenium oxychloride may readily be separatedfrom the carbon tetrachloride by fractionation. Since seleniumoxychloride readily dissolves selenium, the preparation may veryconveniently be carried out by mixing equivalent quantities ofselenium and selenium dioxide, adding selenium oxychloride, andtreating the mixture with chlorine.The second method consists in the partial hydrolysis of seleniumtetrachloride, which may be carried out with the solid tetrachlorideor with the tetrachloride suspended in carbon tetrachloride orselenium oxychloride.The third method is the dehydration of the compound SeO,,ZHCl,which is an amber-coloured liquid and can be prepared by treatingselenium dioxide with dry hydrogen chloride at moderately lowtemperatures.The liquid is mixed with an excess of phosphoricoxide or calcium chloride, and the oxychloride obtained bydistillation. Alternatively, selenium dioxide may be mixedwith the dehydrating agent and treated with hydrogen chloridein the cold. On heating the mixture, the selenium oxychloridepasses off.Selenium oxychloride is a nearly colourless liquid with b. p.176.4" at 726 mm.and m. p. 845°.57 Amongst many interestingproperties of this substance the following may be mentioned.Sulphur, selenium, and tellurium dissolve readily in cold seleniumoxychloride, but when the solutions are heated complicated reactionstake place. Red phosphorus reacts with selenium oxychloride inthe cold with evolution of light and heat, whilst with yellow phos-phorus the reaction is explosive.. Bromine and iodine give solutionswhich are very reactive and are coloured reddish-brown and violetrespectively. Boron, silicon, and carbon are not attacked in thecold.Most of the metals are attacked by selenium oxychloride withformation of the chloride of the metal and selenium monochloride,Se,Cl,.There is it remarkable difference in the behaviour of sodiumand potassium with the oxychloride. No' action takes place withsodium, indeed the oxychloride may be distilled off this metal.Potassium, on the other hand, when brought into contact withselenium oxychloride in the cold, explodes with great violence.Aluminium, zinc, bismuth, and tin are readily attacked, whilst onlyslow reaction takes place with calcium, copper, magnesium, chrom-ium, lead, nickel, arsenic, cadmium, cobalt, gold, and platinum.Powdered antimony takes fire when introduced into the liquid.Selenium oxychloride dissolves selenium dioxide to a limited5 7 V. Lenher, J. Amer. Chem. Xoc., 1921, 43, 29; A., ii, 256INORGANIC CHEMISTRY.55extent. It also dissolves arsenious oxide, vanadium pentoxide, andmolybdenum trioxide, all of which are chemically acted on.The solut,ion of molybdenum trioxide shows a striking photo-chemical reaction, for on exposure to bright light it becomes bluein a few minutes, the solution regaining its original pale yellowcolour within a few hours when kept in a subdued light. Sulphurtrioxide dissolves in selenium oxychloride to form a viscous, heavysolution which has powerful solvent properties. It dissolves theoxides of aluminium, chromium, titanium, columbium, molybdenum,vanadium, uranium, and the rare earths; it dissolves the oxide oftitanium very slowly and has no action on the oxides of-zirconiumand tungsten.The same care is required in handling selenium oxychloride aswith any other highly corrosive liquid.Its vapour has no otherphysiological action than that of the hydrogen chloride producedby its hydrolysis..Group V I I .Some interesting work has been carried out on the equilibria ofhydrofluosilicic a ~ i d . ~ 8 When a solution of hydrofluoric acid wastitrated against sodium hydroxide with phenolphthalein as indicator,an apparently considerable excess of alkali. could be run in and yetthe colour disappeared again after a few seconds. It was found thatthis was due to the presence of hydrofluosilicic acid, even althoughthe hydrofluoric acid was of A.R. standard.A method of investigation of the proportions in which the twoacids are present in the mixture was described by K a t ~ , ~ ~ andconsists in the precipitation of potassium silicofluoride by theaddition of potassium chloride solution followed by alcohol.Thesolution, after filtration, is titrated, and, further, an equal volumeof the original solution is titrated, phenolphthalein being used asindicator in each case. The method is rendered inaccurate by theadsorption of some hydrogen fluoride by the colloidal potassiumsilicofluoride. For the complete neutralisation of hydrofluosilicicacid according to the equation H,SiF, + 6NaOH = 6NaF +H,SiO, + 3H,O, an appreciable time is required,60 and it has nowbeen found that this is due t o the relatively slow dissociation ofsodium silicofluoride according t o the equation Na,SiF6 = 2NaF +SiF4, it being proved that the reaction is unimolecular. This hasenabled a determination to be made of the composition of inixtures6 8 L.J. Hudlestone and H. Bassett, T., 1921, 119, 403.J. Katz, Chem. Zeit., 1904, 28, 356, 387; A., 1904, ii, 442.C. R. Wagner and W. H. Ross, J . Ind. Eng. Chem., 1917,9, 111656 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the two acids.the reaction may be expressed by the eqiations :-When silicon tetrafluoride is passed into water,Sip, + 3H,O = H,SiO, + 4HF,SiF4 + 2HF = H,SiF,,and 3SiF4 + 3H,O = 2H,SiF, + H,SiO,,by addition.The reactions must be reversible, since hydrofluosilicic acid isformed equally by the action of silicon tetrafluoride on water andof hydrofluoric acid on silica, and also hydrofluosilicic acid withsufficient alkali yields, ultimately, sodium fluoride and silicic acid.Therefore all four substances must be present in finite, even althoughpossibly very small, concentration in these solutions. Further,these solutions, filtered from the precipitated silicic acid, on titrationby Katz's method, react like pure hydrofluosilicic acid, so that thefree hydrofluoric acid cannot be in excess of that required to com-bine with the free silicon tetrachloride and silicic acid to formhydrofluosilicic acid.A determination of the amounts pretent in a solution which intotal acidity was 0.05.N showed the following-SiF, 0.0005 mol.perlitre, H,SiF, 0.0045 mol. per litre, and HF 0.021 mo1. per litre. Itwas also proved that the silicic acid must be present in true solution,since its active mass varies with dilution in the ordinary way.When a mixture of potassium perchlorate (3 parts) and chloro-sulphonic acid (5 parts) is gradually heated to 70-75" in a vacuum,a mixture of chlorine heptoxide and pyrosulphuryl chloride passesover.61 Pale yellow chlorine heptoxide (98-99 per cent.) is pre-pared by the distillation of the product in a vacuum, but traces ofsulphur compounds are obstinately retained even after repeateddistillation.The process is almost free from danger.Chlorine heptoxide in a higher state of purity can be obtained bythe very cautious addition of phosphoric oxide to strongly-cooledperchloric acid (70 per cent.) in such a manner that the heptoxidecan ultimately be distilled, but local overheating cannot be avoidedand the yields are poor.Pure solutions of chlorine heptoxide incarbon tetrachloride may be prepared by this method. Con-siderable amounts of phosphoric oxide are suspended in carbontetrachloride, the mixture is cooled to 0" and Giolently stirred,while perchloric acid is added drop by drop. The mixture is warmedand filtered and yields a solution containing about 2.5 per cent. ofchlorine heptoxide. If this solution is distilled as far its possibleat 0" in a water-pump vacuum, a residue remains which containsabout 1/3 of the original carbon tetrachloride and 80 per cent. ofthe heptoxide.61 F. Meyer and H. G. Kessler, Ber., 1921, 54, [B], 566; A., ii, 326INORGANIC CHEMISTRY. 57A colloidal solution of manganese dioxide may conveniently beprepared by the reduction of dilute solutions of potassium perman-ganate by means of ammonia.62 A N/20-solution of potassiumpermanganate is heated to the boiling point and, while stirring,concentrated ammonia solution is added at the rate of one dropevery three or four minutes.At no time should anything but thefaintest smell of ammonia be perceptible. The solution graduallyturns wine-red and finally becomes coffee-brown. To test if all thepermanganate has been reduced, a little of the colloidal solutionmay be coagulated by the addition of sodium chloride to show thepresence of any violet colour which might have been masked by thecolloid. The product only contains potassium hydroxide as animpurity, and as this substance has no action on the colloid, it maybe left in the solution.This eliminates the necessity of removingthe electrolyte by dialysis, especially since the colloid is coagulatedby filter paper or parchment. The colloid a t all concentrationscatalyses the decomposition of hydrogen peroxide. The concen-trated solutions are coagulated during the reaction, whilst dilutesolutions are unaffected. The colloid is perfectly stable in thepresence of alcohol of all concentrations.Group VIII.The formation of sodium ferrite and ferrate by electrolysis ofsodium hydroxide solution with iron anodes has been investigated, 63and it is found that these salts only are formed, since the iron passesinto solution only in the bivalent or sexavalent condition.Sodiumferrite may also be obtained by cathodic reduction of a solution ofsodium ferrate. Measurements of the equilibrium potential of ironagainst a sodium ferrite solution and of platinum against mixturesof ferrite and ferrate show that the ferrite solution is more complexthan is represented by the simple formula Na,FeO,.Commercial platinum may be freed from the impurities it usuallycontains by repeated precipitation as ammonium platinichloricle. 64It was found that a sample of platinum containing palladium,rhodium, and iridium, as well as considerable amounts of tin, iron,and other metals, can be obtained in the pure state by four suchprecipitations. Each precipitate of ammonium platinichloride isdrained on a Buchner funnel, stirred with a considerable volume of15-20 per cent.ammonium chloride solution, and again drained,this process being repeated two or three times. The washed pre-62 E. J. Guy, J . Physical Chem., 1921, 25, 415; A., ii, 642.63 G. Grube and H. Gmelin, 2. Elektrochem., 1920, 26, 459; A,, ii, 49.64 E. Wichers, J. Amer. Chem. SOC., 1921, 43, 1268; A,, ii, 64858 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.cipitate is dried, ignited to platinum sponge in an electrically heatedmuffle, and dissolved in aqua regia. The solution is. evaporatedseveral times with hydrochloric acid to remove nitric acid andprecipitated with ammonium chloride. The amount of platinumleft in the mother-liquor from the precipitate is usually not morethan 1 per cent.of that in the precipitate. The final precipitate isignited to sponge in a porcelain dish over a gas flame in a current ofhydrogen.In the Reports for the last two years reference was made t o workon the occlusive power of platinum and palladium for hydrogen,and brief mention may be made of some further investigations.I n the first place, it has been confkmed that the amount of hydrogenoccluded by palladium is determined by the relative amountspresent of the two forms of the metal, the amorphous and thecrystalline. 65 In all probability this explains the divergent resultsobtained by Hemptinne 66 and by Paal and Amberger,67 since theocclusive power of the crystalline variety is very much reduced a tlow temperatures.I n last year's Report the reporter criticised Dr.Maxted's inter-pretation of the results he obtained on the poisoning of palladiumby hydrogen sulphide, and suggested that the adsorption of hydrogenconsists of two separate processes, first, the occlusion of hydrogenas atoms, followed by a secondary effect of condensation as molecules.Dr. Maxted has now brought forward evidence which stronglysupports this view, and, moreover, brings the results more intoagreement with the modern views of catalytic activation by metals. 68This is well shown by the results obt,ained on the poisoning ofpalladium by lead, in which for a known lead content both theocclusive power for hydrogen and the catalytic activity of theproduct were measured. The catalytic activity is a linear functionof the lead content up t o a stage in which the greater part of theactivity has been suppresse,d. A point of inflection occurs at thisstage, below which the decrease of activity caused by furtheraddition of lead falls off far less steeply. The occlusive power forhydrogen is also a linear function of the lead content, but the slopeof the two lines is very different. Thus, a ratio of 0.17 gram-atomof lead to 1 gram-atom of palladium is required to reduce theocclusive power to one-half, whilst in order to reduce the catalyticactivity to one-half, only about 0.02 gram-atom of lead to each65 J. B. Firth, T., 1921, 119, 1120.66 A. de Hemptinne, Bull. Acad. Toy. Belg., 1898, [iii], 36, 155; A., 1899,6 7 C. Pad and C. Amberger, Ber., 1905,28, 1394; A., 1905, ii, 397.68 E. B. Maxted, Z'., 1920, 117,f1501; 1921,f119, 1280.ii, 228INORGANIC CHEMISTRY. 59gram-atom of palladium is necessary. It is probable thereforethat, whilst the occlusion is not confined to the surface only of thepalladium, catalysis is mainly a surface phenomenon. This viewis strengthened by the fact that the slope of the poisoning line forcatalytic activity varies with the fineness of division of the catalyst.It is evident from these observations that, as suggested, thereare two processes, namely, the adsorption and activation of thehydrogen on the surface of the catalyst, and the condensation ofmore hydrogen as molecules within the capillaries. Apart fromthe bearing of this on Dr. Maxted's previous work, it has considerableimportance from the energy side, since energy must be given to thehydrogen molecules in order to activate them. This energy mustbe supplied by the palladium, and it is not possible to believe thatthis action can extend beyond a molecular layer of hydrogen dis-tributed over the surface of the metal. In this connexion recentexperimental work tends more and more to show that in all similarcases of heterogeneous catalysis the thickness of the activated layeris of molecular dimensions.By the reduction of sodium platinichloride with an excess ofsodium hyposulphite a dark reddish-brown solution is obtainedwhich, on slow evaporation, deposits a precipitate which is a com-plex mixture of sodium platinosulphite compounds with Na2Pf4S6. 69After filtration, the solution first deposits crystals of sodium platini-sulphite, Na,[Pt(SO,),( OH),],H,O, and then, on further evaporation,bright yellow crystals of sodium platinothiosulphate,Na5[Pt(S#3)4], 10H2O.By reduction of iridium tetrachloride in neutral solution sodiumiridosulphite, Na,[Ir(SO,),], 10H20, was obtained in bright yellowcrystals.Na,[Rh,(SO,) ,],12H,O; Na,[Os,(SO,) ,],24H,O,andNa,H,[Ru(SO3)pl.The following salts were also prepared,E. C. C. BALY.69 G. Sailer,"Z. anorg. Chem., 1921, 116, 209; A., ii, 513

ISSN:0365-6217    

DOI:10.1039/AR9211800030

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

ORGANIC CHEMISTRY,PART I.-ALIPHATIC DIVISION.THE usual arrangement of this division of the Annual Reports hasbeen followed, except that the section dealing with optical activityhas been omitted this year as only a few papers on the subject haveappeared.Hydrocarbons.The problem of converting natural paraffin into a mixture offatty acids is still receiving attention, although apparently verylittle progress has been made. Schaarschmidt and Thiele chlori-nate paraffin a t 160" and then remove hydrogen chloride either bytreatment with alkali or by simply heating at about 300"; theresulting mixture of olefines is then oxidised, preferably by ozone,and under the best conditions a yield of about 60 per cent. of thehigher fatty acids is obtained. No better results were obtained byGranacher,2 who oxidised heated paraffin wax by a current of aircontaining 2 per cent.of nitrogen peroxide. At 150", the processrequires about four days. When n-undecane is treated in the samemanner, nonoic is the highest acid formed, and this only in smallquantity. The method is therefore unsuitable for the degradationof hydrocarbons, but shows that the higher paraffins in nature mustconsist only to a small extent of normal hydrocarbons.The combination of acetylene with water in the presence ofvarious catalysts to form acetaldehyde has again been investigated,mainly because of the difficulty of regenerating the catalysts; thiscan be done, when oxides such as molybdic acid are used, by acurrent of air at a high temperature 3 or by the periodic addition offerric oxide to a heated solution of mercuric ~ulphate.~ In thisconnexion, the discovery by W.J. Jenkins of a new compound ofacetylene and mercuric chloride, HgC12,2C2H2, which containsdouble the amount of acetylene to that in the well-known compound,1 Ber., 1920, 53, [B], 2128; A., i, 1.Helv. Chim. Acta, 1920, 3, 721; A., i, 2.3 D. R.-P. 334357; A , , i, 542.Brit. Pat. 140784; A., i, 706ORGANIC CHEMISTRY. 61may be of some practical interest. Kindler has observed thatgold is quantitatively precipitated from dilute solutions of theauric haloids by acetylene, which is thereby converted into glyoxal.Alcohols and Derivatives.Very little research has been published on alcohols during theyear, but a few new methods of preparation are of interest.Methyl alcohol 7 is readily purified from acetone by takingadvantage of the fact that methyl alcohol and chloroform form abinary mixture boiling at 53" at atmospheric pressure.In practice,1 part of the crude alcohol is mixed with 7.5 parts of chloroform, themixture distilled, and then from the fraction boiling at about 53"the methyl alcohol is extracted by water, the aqueous alcohol beingrectified in the usual manner.Acetaldehyde8 can be reduced in an economical manner if ledinto the cathode chamber of an electrolytic cell charged with asuitable acid medium in such a manner that the concentration ofthe acetaldehyde in the solution is maintained low. When thisdoes not exceed about 5 per cent.the yield of alcohol is good andthe current efficiency high.The preparation of primary alcohols by the action of Grignard'sreagents on trioxymethylene is rendered very tedious by its sparingsolubility in ether and its very gradual depolymerisation. Theusual small yields are much improved and the time required is muchshortened if the vapours from well-dried boiling trioxymethyleneare led into a well-stirred Grignard reagent. The yield of thealcohols, R*CH,*OH, is reduced when R is small (particularly whenR = C,H,), owing to the formation of considerable quantities of themethylene ethers, CH,(OR),.Secondary butyl alcohol is very easily prepared from the butyleneformed by the catalytic dehydration of n-butanol. The liquefiedp-butylene lo is mixed with 75 per cent. sulphuric, with phosphoricor with benzenesulphonic acid, either a t the ordinary temperatureunder increased pressure or a t - 10" under atmospheric pressure.When absorption of the hydrocarbon is complete, the liquid isdiluted with water and the secondary alcohol distilled over with acurrent of steam.Many of the preparations carried out by modern methods ofBer., 1921, 54, [B], 647; A , , i, 396.A.Lanzenberg and J. Duclaux, Bull. SOC. chim., 1921, [iv], 29, 135;Chern. Fabrik Greisheim Elektron, D. R.-P. 328342; A, i, 155.K. Ziegler, Ber., 1921, 54, [B], 737; A., i, 394.A., i, 298.lo C. Weizmann and D, A. Legg, Brit. Pat. 161591; A,, i, 49362 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.catalysis at high temperatures are unsatisfactory owing to con-tamination with small amounts of impurities formed by isomericchange under the influence of the catalyst.This phenomenon iswell illustrated by a quantitative study of the products of thedehydrogenation of the mixture of amyl alcohols produced byfermentation. Using a'luminium silicate heated a t 350" as thecatalyst, Senderens l1 has shown that the relative proportion of thethree hydrocarbons, p-methyl-As-butene, p-methyl-Aa-butene, andy-methyl-Aa-butene, the last two of which may be assumed to beformed direct from the p-methylbutan-a-ol, CH,*CH,*CHMe*CH,*OH,and from the isobutylcarbinol respectively, varies considerably withthe age of the catalyst. I n the fermentation alcohol there isgenerally about 87 per cent.of isobutylcarbinol and 13 per cent. ofthe optically active constituent, but the proportion of y-methyl-Aa-butene is always very much less than that of the P-methyl isomeride.When the catalyst is new and active, nearly four-fifths of the productconsists of p-methyl-hp- butene obviously formed by isomeric changefrom @-methyl- Aa-butene under the influence of the catalyst, since,when this ages, the proportion of these two hydrocarbons in theproduct becomes nearly equal, whilst that of the y-methyl- Aa-butene,which is only one-thirtieth with the fresh catalyst, amounts to one-fifth of the product.The proportion of the various isomerides may, moreover, dependon the pressure, for Moureu and Mignonac l2 have shown that thisaffects the dehydrogenation of alcohols when this is carried out bycontact with oxygen and finely divided silver a t 230-300".The reaction between alcohols and hydrogen sulphide to formmercaptans 1, is brought about by specially prepared thorium oxidea t 380".The catalyst needs to be formed from the nitrate bydecomposition of this in a current of air at 270°, and thus differsfrom the ordinary thoria commonly used as a catalyst in otherreactions. The yields amount t o 40 to 50 per cent. when the vapourof the alcohol and the hydrogen sulphide are passed over thecafalyst a t the rate of 1 gram-molecule per hour. The mercaptansgive mixtures of constant boiling point with the correspondingalcohols and are best purified by means of their lead salts.Acids and their Derivatives.It is well known that the acetylating action of acetic anhydrideis often increased by the addition to it of traces of concentrated11 Compt.rend., 1920, 171, 916; A,, i, 4.12 Ibid., 652; A., 1920, i, 805.13 R. L. Kramer and E. E. Reid, J . Amer. Chem. SOC., 1921, 43, 880;A., i, 389ORGANIC CHEMISTRY. 63sulphuric acid. This is probably due to the formation of smallamounts of acetylsulphuric acid, CH,*CO*O*SO,*OH, the preparationand properties of which have been described by van Peski.14 It isformed when sulphur trioxide acts on acetic acid a t 0", and reactswith sodium acetate to form sodium acetylsulphate. This salt,when heated, decomposes, giving sodium pyrosulphate and aceticanhydride, but when heated with acetic acid gives acetic anhydrideand sodium hydrogen sulphate, a reaction which is reversible.When heated a t 70", acetylsulphuric acid is converted into sulpho-acetic acid, which is readily acetylated by acetylsulphuric acid,forming acetylsulphoacetic acid ; the latter readily condenses toCH,*CO> c< CO*O*cMeform disulpho-dehydroacetic acid, SO,H CO-C*SO,H.Acetylsulphuric acid is a very vigorous acetylating agent, acetylat -ing, for example, tribromophenol with ease ; in some cases, however,it acts as a sulphonating agent, converting benzene, for example,into benzenesulphonic acid.Acetylene will combine with acetic acid to form ethylidenediacetate quantitatively under certain conditions in the presence ofa variety of catalysts. The best of these appear to be methylenesulphate a t about 50", methyl sulphate l5 at about 75", or mercurynaphthalene- p-sulphonate l6 a t a temperature of about 50".Zirconium oxide l7 must be added to the list of substances whichare capable of bringing about the condensation of the vapours ofacids and alcohols to form esters.This catalyst works best a t atemperature of 270-290", whilst the yield of ester depends on theweight of oxide used, the velocity of the flow of the vapours, andthe proportion of acid and alcohol used.There have been many observations of interaction between estersand alcohols in the presence of catalysts, leading to the formationof new esters. to the fact thatglycerol a-monobenzoate is moderately rapidly converted in etherealsolution in the presence of potassium carbonate into a mixture ofglycerol and a dibenzoate.The process is more conveniently followedwith the benzoyl derivatives of ethylene glycol in chloroformsolution, whereby it is qhown that the change is balanced and attainsan equilibrium in the presence of the glycol and the mono- and di-benzoates. Similarly, glycerol monoacetate is largely transformedAttention was directed by Fischer1 4 Rec. trav. chim., 1921, 40, 103; A , , i, 302.1 5 D. R.-P. 322746; A., 1920, i, 810.16 Ibid., 334554; A., i, 535.l7 A. Mailhe and F. de Godon, Bull. Soc. chim., 1921, [iv], 29, 101; A , ,18 E. Fischer, E. Pfahler, and F. Brauns, Ber., 1920, 53, [B], 1634; A..,i, 219.1920, i, 84064 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.into diacetin and glycerol.The action of the potassium carbonateappears to be definitely catalytic, since very small amounts of itsuffice to accelerate the change. The phenomena recorded in thispaper are very similar to those first observed by Purdie,lg whofound that an exchange of alkyl radicles readily took place betweensimple esters and alcohols in the presence of a small amount ofsodium alkyloxide. Grun20 has now shown that this interchangeof akyl groups between fats and alcohols can take place undercertain conditions even in the absence of catalysts.Such phenomena explain to some extentr, the gradual change inmelting point observed by Grun to take place when diacyl derivativesof glycerol are preserved and also of the so-called " ageing '' of thenatural fats.This, however, is not a complete explanation of allthe facts, as some of the triglycerides are known in more than oneform, as, for example, tristearin, which exists in two forms, m. p.55" and 71" respectively. Grun prefers to regard these as examplesof co-ordination isomerism, in which most of the esters (fats) maybe regarded as an equilibrium mixture of the forms R*C<gR, andR*C<g}Rf. According to the author's views, then, a mono-glyceride can exist in two forms, (OH),C,H5*O*C<B 0 and( OH)2C3H;::::::02CR, a diglyceride in three forms,whilst a triglyceride formed from a single acid can exist in fourforms, namely, the ordinary ester and pure co-ordination varietiesand two mixed types. Thus the co-ordination form of a triglycerideformed from a single acid only can pass into the true ester form,but from the co-ordination form of a mixed triglyceride, a mono-or a di-glyceride, all the structural isomerides can, in addition, beproduced. This hypothesis, although somewhat intangible, doesserve to correlate the numerous and otherwise confusing facts whichare recorded in the author's papers, and is very similar to thoseput forward by other investigators t o explain the abnormal physicalproperties of some esters.The phenomena described in the preceding paragraphs render thesynthesis of pure glycerides a matter of some considerable difficulty.For this reason, a method for the synthesis of optically active c@-18 T.Purdie, T., 1887, 53, 391.20 A, Griin, F, Wittka, and J.Scholze, Ber., 1921, 64, [B], 273, 290; A.,i, 220, 222ORGANIC CHEMISTRY. 65riiglycerides and iinsymmetrical triglycerides in which the positionof the respective acyl groups is tolerably certain is very welcome.Such a synthesis which, although somewhat complex, seeins to avoidthe possibility of the interchange of acyl groups, is described byM. Bergman and his co-workers.21 The starting point is y-amino-ap-propylene glycol, which is readily obtained by the action ofammonia on glycide. The aminoglycol is first of all condensed withbenzaldehyde, thus forming 2 - phenyl- 5- hydrox ymeth yloxazolidine,CH2*yH0--- c HPh'This contains one alcoholic hydroxyl OH*CH,*CH<group, which can be acylated. The ring in the resulting acylatedcompound is readily opened up with the elimination of benzaldehyde,giving compounds of the formula OA*CH,*CK(OH)*CH,*NHA.These can be treated with another acylating agent, giving compoundsof the type OA*CH,*CH( OB)*CH,*NHA.Mild treatment withphosphorus pentachloride and water converts these int'o compoundsof the type OA*CH,*CH( OB)*CH,*NH2, which can be resolved intotheir optically active components. By treatment with nitrous acid,there are obtained a@-diglycerides, OA*CH,*CH( OB)*CH,*OH,which can be converted into unsymmetrical triglycerides. Thepresence of two asymmetric 'carbon atoms in the oxazolidine doesnot interfere with these syntheses, as one disappears on removal ofthe benzaldehyde when the ring is ruptured.So far, the syntheses have been carried out only with benzoyl andnitro- and chloro-substituted benzoyl groups as acylating agents.The resolution of y-aminopropylene ap-dibenzoate was effected bycrystallisation of its quinate, and after treatment with nitrous acidgave the oily I-glycerol ap-dibenzoate.This was further treatedwith p-nitrobenzoyl chloride, giving E-glyceryl ap-dibenzoatey-p-nitrobenzoate with m. p. 114" and with [.ID - 1.9" in s-tetra-chloroethane. This compound is claimed by the authors to be thefirst example of the synthesis of a homogeneous, optically activetriglyceride. It may be pointed out, however, that the homogeneouscharacter of their preparation is not definitely proved, whilst thelow rotation may be caused by racemisation during its production.M. Tsujimoto 22 has observed that the lithium salts of the morehighly unsaturated acids derived from fish oils arc readily solublein acetone containing 5 per cent.of water, and since those of thesaturated or slightly unsaturated acids are insoluble in this solventa separation can be effected and gives amounts of highly unsaturatedacids which are considerably higher than those calculated from theyields of the polybromides.21 Ber., 1921, 54, [B], 936; A . , i, 444.22 J . Chem. Ind. Japan, 1920, 23, 1007; A., i, 78.REP.-VOL. XVIII. 66 SNNUAL REPORTS ON THE PROGRESS OF (‘HTCMJSTRY.For thc synthesis of thc I,czsio ckrivat,ivcs of cocaine, sucoiiiyl-diacetic acid is a convcnicnt starting point. A satisfactory prepara-tion of this acid has been described by Willstatter and Yfannen~tiel,~~who have obtained the dipotassium derivative of the enolic form ofethyl hydrogen acetonedicarboxylate, CO,Et.CH,-C( OK):CH*CO,K.A solution of this compound, after neutralisation by oxalic acid ofthf enolic potassium, is readily converted by electrolysis into thediethyl ester of the required acid, C,H,(CO*CH,*CO,Et),, which showsthe properties of an enol and exhibits the reactions of a p-ketonicester.The acid and its esters readily condense with amincs to givepyrrole derivatives of the t,ype NMe< C( CH,*CO,Et):yHC(CH2*C02Et):CH .In last year’s Report, the successful separation was described ofthe keto-form of ethyl acetoacetate by K. Meyer and co-workers,who fractionated the equilibrium mixture in specially cleaneddistillation flasks of quartz under a pressure of 2 mm.The isolationof the pure enol form is now described.24 For this purpose, theequilibrium ester is distilled from a Jena glass flask in the presenceof a trace of phthalic acid. The distillate, which is collected in aquartz receiver, contains nearly 90 per cent. of the enol and isimmediately refractionated from a silica apparatus, the first fractionbeing composed of the pure enol. Similar results have been obtainedby distillation of acetylacetone, which, however, appears to be farmore sensitive than ethyl acetoacetate to the influence of catalysts.Ingold 25 has investigated the mechanism underlying the reactionof ethyl cyanoacetate with tautomeric conipounds and shown thatin the great majority of cases the first stage is the addition of thecyano-ester to the double bond.This in all probability is thereason why the polyacetic acids of methane such as the triaceticacid, CH( CH2*C02H),, carboxytriacetic acid, C0,H*C(CH2*C0,H)3,and the tetra-acetic acid, C(CH2*C02H),, are all difficult to prepare,since the corresponding unsaturated acids, CO,H*CH:CH*CH,*CO,H,C02H.CH:C(C02H)*CH2*C02H, and CO,H*CH:C(CH,.CO,H),, area11 substances of the glutaconic acid type with a mobile hydrogenatom---a series of compounds which have been shown by J. F.Thorpe and his co-workers to be exceedingly unreactive and notunsaturated in the ordinary sense of the term. Methanetriaceticacid,26 however, can be prepared readily by the condensation ofcthyl sodiocyanoacetate with diethyl fbhydroxyglutarate andsubsequent hydrolysis of the product. Further investigation 27 of23 Annalen, 1921, 422, 1 ; d., i, 91.24 K.H. Meyer and H. Hopff, Ber., 1921, 54, [B], 579; A . , i, 301.2 6 C. K. Iiigold, T., 1921, 119, 329.2 6 ldem, ibid., 336.2 7 C. K. Ingold and E. A. Perren, ibid., 1 3 2 ORGANIC CIIEMISTRT. 67tlic coiictuiistttioii o€ highly substituted glutrtcoilic: csturs ancl ethylcyanoacetate shows that in derivat'ives of methanetriacetic acidsubstituents in more than one of tlhe acetic acid chains produce acondition of instability.Constitution of Grignard's Lklagnesium Compounds.MgAlk >O<Hal.OEt,, which have from time to time been assigned EtE t Yto Grignard's reagents must be regarded as unsatisfactory, since theyfail to account for the full reactivity of the substances. Meisenheimerand Gaspar28 therefore propose to regard them as complex com-pounds of magnesium in which the central atom has the co-ordina-Et20.-... Alk tion number 4, thus : Et20...->Mg<Hal. I n this formula t,he alkylgroup and halogen atom- are united to the magnesium by mainvalencies, the ether molecules by subsidiary valencies. Whenbrought into contact with acetone, etc., the latter, by virtue of itsgreater reaction energy, displaces a molecule of ether, yielding thesubstance MgFg::'Mp<Hal. Alk It is suggested that re-arrangement2of the bonds within the complex then occurs by which the subsidiarybond between the magnesium and the carbonyl oxygen becomes achief bond; the alkyl group which has thus become detached fromthe magnesium atom attaches itself to the chief bond of the carbonylcarbon atom which has simultaneously become free, and the vacantco-ordination position of the magnesium atom is taken by a moleculeof ether, thus : M e 2 c A ~ $ > M g < ~ ~ ~ .This conception is incomplete harmony with the observation of Ahrens and Stapler 2*athat magnesium bromide and iodide form dietherates from whichone molecule of ether can be displaced readily by a moleculeof aldehyde, ketone, or amine. It also explains the peculiarbehaviour of allyl haloids towards magnesium; as the final productof these reactions, a crystalline mass is obtained which consistsentirely of the magnesium haloid dietherate, the allyl radicle beingquantitatively contained in the ethereal solution in the form ofdiallyl.Theprimary reaction consists in the formation of a normal GrignardThe course of the reaction is explained as follows :compound, Et2O Et20.,.iMg<&H5, .-. from which a molecule of ether isimmediately displaced by a further inoleculc of allyl bromide,2 R Ber., 1921, 54, [BJ, 1665; A . , i, 654. 2da -4., 1905, i, 868.D 68 .lNNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.Et2C) ....p~g<$H5. 111 t’liis complex, the atuyl residiio of t ~ i c C3H,Br ’*alkyl haloid is only loosely attached by reason of the union of thebromine atom to the magnesiurn, which may be thus expressed :C,H,[EtgI;;*Yg<B; C H 5 ] As a consequence, when two suchmolecules come within range of one another, the allyl residue isreadily detached, yielding diallyl. Simultaneously, a change inbonds occurs by which the second bromine atom becomes attachedby a main valency to the magnesium atom and the diallyl groupby a subsidiary valency.A hydrocarbon such as diallyl has,however, but little free valency, and is therefore readily displacedby the ether, thus giving a magnesium haloid dietherate. Thepeculiar property of allyl haloids is due to the reactivity of thehalogen atom in these compounds and the relatively large amount ofthe available valency of the halogen atom. It is to be expectedfurther that allyl bromide would have the same power of displacingether from any similarly constituted Grignard conipound.This isshown to be the case, since allyl bromide is found to react withethereal solutions of magnesium methyl, ethyl, or phenyl bromide togive thc magnesium Eialoid dicktheratc, and lmtene, pentene, aidallylbenzene respectively.The catalytic activity of ether and tertiary amines in promotingthe action between magnesium and alkyl haloids cannot be ex-plained satisfactorily by the assumption of the formation of oxoniumsalts of the type Et>O ~:.p, since in this case a mixture of mag-nesium methyl and ethyl iodides must result. This difficulty isovercome by considering that the action between ether or baseand alkyl haloid proceeds only to the subsidiary valency stage,EtEt>O----MeI, Alk,N----PhI, which accounts thus for the unusual Etmobility of the halogen atom.The reducing action of the Grignard reagent under some conditionsis assumed by K.Hess and H. Rheinboldt 29 to be due to magnesiumhydrogen haloid. These authors also represent these reagents byco-ordination formulax They show that, under the conditionscustomary in the preparation of Grignard’s reagents, magnesiumdoes not react with gaseous hydrogen chloride in the presence ofether or benzene. Liquid hydriodic acid does not attack magnesium,whereas in the presence of dry ether a reaction occurs readily which,however, is due to the ready conversion of ether into et,hyl iodide byhydrogen iodide. To avoid complications of this type, the ((in-dividual ” Grignard compounds were used, when it was found that29 Ber., 1921, 54, [ B ] , 2043; A., i, 7 7 7 ma,gnesium ethyl iodide does not react with gaseous or liquidhydrogen iodide, alone or in the presence of benzene, whereas it isdecomposed completely by hydrogen chloride with the liberationof ethane.Attempts to demonstrate the unaltered nature of themagnesium ethyl iodide after treatment with hydrogen iodide bybringing it into reaction with benzaldehyde led to the rather surpris-ing isolation of benzyl alcohol instead of tlhe expected phenylethyl-carbinol. A similar result was observed with untreated magnesiumethyl iodide in warm benzene and, but to a less extent, in warmether, whereas phenylethylcarbinol was exclusively obtained inethereal solution a t the atmospheric temperature.According to these authors, the Grignard compounds can hcrepresented most accurately by co-ordination formule, as, for, and the reductions then occur in example, RR'C:O----.~g<.cH2,CH, Braccordance with the scheme :warmed -+ R' R>,o..---.&~-~<x H + EHz CH,-+R +H,O R>C<gH + Mg<&.Since i t is shown that the subsidiary reaction may be made into themain change by increasing the temperature, it is possible that amethod is opened out for the reduction of substances containing theketonic group and other reducible groups (for example, ethyleniclinkings) which are not changed by reduction of the ketonic group.In any case, it is demonstrated that the avoidance of subsidiaryreactions in the case of the aliphatic alkyl haloids (except the methylcompounds) can only be secured by the avoidance of elevatedtemperature, except under perfectly definite conditions.Catalytic Hydrogenation and Dehydrogenation.During the last three years much attention has been devoted tofinding a satisfactory explanation of the phenomena observedduring the catalytic hydrogenation of unsaturated compounds, theactivation of the catalysts, and the catalytic dehydrogenation ofalcohols.It is still an open question whether oxygen is necessary for theactivat'ion of hydrogenating catalysts, and most of the workrecently published bears on this point.In a series of papers by E.F. Armstrong and T. P. H i l d i t ~ h , ~ ~the linear nature of the reaction-time curve, a t least in the earlierProc. Roy.SOC., 1919, [ A ] , 96, 137, 322; A . , 1919, ii, 403; 1920, ii, 102;;hid., 1920, [A], 97, 2 5 9 ; 98, 3 7 ; -I., 1920, ii, 122, 00s; ibicl., 1921. f.1 1. 99,4!)0; A . , ii, 582 et s q 70 ANNUAL ElWORTS OX THE PROGRESS OF CHEMISTRYstages of the reaction, for catalysis at solid surfaces is demonstratedand shown to compare with hydrolysis brought about by meansof enzymes. These investigators conclude that unstable complexesof catalyst and unsaturated compound are formed which breakdown on addition of hydrogen to saturated compound and regener-ated catalyst. By this means, they explain the fact that hydro-genation and dehydrogenation may proceed simultaneously, evena t the optimum temperature for the former process.They havesucceeded, by using the reacting compounds in the liquid state,in hydrogenating an unsaturated compound a t the expense of asaturated compound, which thereby undergoes reduction. Withreduced nickel as the catalyst, a mixture of cyclohexanol and methylcinnamate a t 180" gave a certain amount of cyclohexanone andmethyl P-phenylpropionate ; whilst a mixture of ethyl stearateand methyl cinnamate a t 230" produced a small quantity of methylp-phenylpropionate together with some ethyl oleate, although theamount of the latter was insufficient to enable the authors todetermine whether it was the ordinary (A9:lo) ethyl oleate orthe ethyl isooleate ( AIO :I1 OrEither copper or nickel may be used to hydrogenate acetalde-hyde or to dehydrogenate ethyl alcohol.It is noteworthy thatthc presence of a trace of water inhibits the former and promotesthe latter reaction. The apparent specific volume has been shownby these same investigators to influence the activity of a catalyst :that is to say, a bullcy preparation of nickel, or one supported onan inert substaiice, such as kieselguhr, is more active catalyticallythan a more compact preparation, such as one formed by reductionof the fused oxide. From their numerical results, Armstrong andHilditch deduce that thc catalytic activity of nickel can be satis-factorily explained by a consideration of the surface exposed, andthat it is unnecessary to postulate thc presence of oxides of nickelin the catalyst.They have also established that simple ethylenic compounds arehydrogenated, in presence of suacient nickel, a t rates whichare in approximately exact proportion to the absolute pressure ofthe hydrogen.At extremely low concentrations of the catalyst,the increase in rate of hydrogenation becomes less than proportionalto the increase in pressure, especially in the cases of multi-ethyleniccompounds such as linolein or citral. On the other hand, thepresence of a group in the organic compound which has affinityfor nickel, but is not open to hydrogenation, causes the speed ofhydrogenation to increase with abnormal rapidity as the hydrogenpressure is increased. Thus the relation between rate of action:12) described previously by Moore.3131 J .Sac. C'hem. Z n d . , 2919, 38, 3 2 0 ~ ORGANIC: CIIEMISTRY. 71and hydrogen. concentration is evidently governed by the type oforganic compound present. These results harmonise completelywith the view that the process is primarily conditioned by anassociation of the ethylenic linking with the catalyst, which is itselfassociated with hydrogen.W. G. Palmer 3t has studied the activity of copper as a catalystfor the dehydrogenation of the lower aliphatic alcohols. He findsthat, although electrolytic copper, both when pure and when alloyedwith zinc, is catalytically inactive, copper prepared by reductionof its oxide promotes dehydrogenation, although its activitydecreases with time. He concludes that the active material iscopper in the cuprous form, that the inactivation is due to a slowchange of these molecules into the more stable cupric form, andthat oxides of copper play no part in the catalysis. The sameauthor in conjunction with (Miss) D.M. Palmer 33 has investigatedthe reduction of ethylene to ethane with nickel as a catalyst.From their results they infer that a preliminary selective adsorp-tion of hydrogen takes place on the catalyst : thermal contact withethylene molecules then causes evaporation of hydrogen andany ctliane formed, after which ethylene is adsorbed on the catalystand a nearly steady state of reaction is attained.Rosenmund, Zetzsche, and Heise34 have developed a theory ofthe influencing of catadysts by small quantitics of other substances.By the addition of minute amounts of suitable promoters or inhibit-ants they have been able to control the reduction of benzoyl chloridein the presence of palladium or palladinised barium sulphate insuch a manner that the chief reactlion product may be benzaldehyde,benzyl alcohol, benzyl benzoate, dibenzyl ether, or toluene.Theregulating substances were chosen to contain an element of variablevalency, among the more important being quinoline, xanthone,dimethylaniline, and particularly quinoline which had been heatedwith sulphnr.In addition to the reduction of benzoyl chloride, Rosenmund andZetzsche have studied the dehydrogenation of alcohols in the liquid~ t a t e . 3 ~ All the metals used as catalysts were practically inactive,but addition of quinoline induced specific activity, especially inthe cases of copper, nickel, and silver.The best yields of aldehydesare obtained by the catalytic oxidation of an equimolecular mixtureof alcohol, quinoline, and m-dinitrobenzene in cumene solutionin the prescnce of copper. Secondary alcohols can be similarly32 l’roc. Itoy. SOC., 1920, [ A ] , 98, 13; A . , 1920, ii, 0 9 .33 lbicl., 1921, [-I], 99, 402; il., ii, 541.3* Be).., 1021, 54, [B], 426, 633, 2038; A., ii, 320, 302, 632.35 l b i d . , 1092, 2033; d., ii, 393, 63172 ANNUAL REPORTS ON THE PROGRESS OF CWEMISTKY.oxidised to ketones, but tertiary alcohols are not attacked by thismethod.The use of platinum and palladium both in the colloidal andin the spongy state for catalytic hydrogenation has been shown byWillstatter and Waldschmidt-Leitz 36 to depend on the presenceof oxygen in the catalyst. According to their view, the catalystfunctions alternately as a peroxide (with the metal bivalent) and asa combined hydride and peroxide (with the metal quadrivalent),thus effecting the transfer of hydrogen.By treating their metalsin suspension in glacial acetic acid with hydrogen they have obtainedinactive catalysts which, however, are easily reactivated by shakingwit>h air. They consider that some, but not all, cases of catalystpoisoning during hydrogenation are due to the gradual removal ofthe oxygen necessary for catalysis.Similar results were found in the case of nickel : the lower oxideswere catalytically active, but the pure metal, free from oxygen,was inactive until primed with a small quantity of air.Kelber,3'however, carrying out hydrogenations a t laboratory temperature,has been unable to confirm these observations in the case of nickelreduced from the carbonate and from the oxalate via the oxide,and has found that his catalyst becomes inactive when shaken withoxygen, and that treatment with hydrogen a t 70-80" is thennecessary to reactivate it. It seems only fair, however, to pointout that Kelber's work was done with sodium cinnamate, whereasWillstatter and Waldschmidt-Leitz used a far greater variety ofsubstances, including benzene, cyclohexene, limonene, pyrrole,phthalic anhydride, o-benzylbenzoic acid, and o-naphthoylbenzoicacid.Willstatter and Waldschmidt -Leitz divide unsaturated compoundsinto three classes, according to the ease with which they are hydro-genated : (a) ethylenic substances, which are reduced so rapidlythat the rate of loss of oxygen from the catalyst is negligible incomparison ; ( b ) simple aromatic compounds, which are hydro-genated with much less speed than the olefines, so that loss ofoxygen, especially from small amounts of catalyst, may have amarked retarding effect on the velocity of hydrogenation; and(c) other substances, such as polynuclear aromatic compounds,the rate of hydrogenation of which is so small that deoxygenationof the catalyst occurs long before the hydrogenation is complete.In cases of this type, they recommend activation of the catalystby priming with oxygen from time to time, as suggested byWillstiitter and J a q ~ e t .~ ~36 Ber., 1921, 54, [BJ, 113; A . , ii, 185.38 Ibid., 1918, 51, 767; A . , 1918, i, 391.37 Ibid., 1701 ; A . , ii, 630ORGANIC CHEMISTRY. 73The application of the Nernst heat theorem, using the approxima-tion formula, to the equilibria acetaldehyde, hydrogen, ethylalcohol ; and acetone, hydrogen, isopropyl alcohol, has been carriedout by E. K. Rideal,39 who confirms Sabatier's results that nearlycomplete hydrogenation or dehydrogenation can occur within thesmall temperature range from 100-350".E. B. Ma~ted,~O using platinum and palladium as catalysts forthe hydrogenation of oleic acid, has shown that the decrease inactivity caused by the poisons lead, mercury, sulphur, arsenic,and zinc is, within the limits zero concentration of the inhibitantnearly to the concentration producing complete inactivation, directlyproportional to the concentration of the inhibitant. He has alreadyshown 41 that the occlusive power of palladium for hydrogen varicsdirectly as the content of inhibitant (hydrogen sulphide in thiscase), so that it follows that the occlusive power for hydrogen variesdirectly as the catalytic activity.This result he has experimentallydemonstrated' for catalytic palladium poisoned by lead and usingoleic acid as before.42 He notes, however, that although the cata-lytic activity and occlusive power vary lineally with the concen-tration of the poison, the former property is much more susceptibleto poisoning than the latter.In explanation of this, he suggeststhat whilst catalytic power is mainly a function of surface exposed,occlusion is not confined to the surface.Carbohydrates.Much activity has been displayed in the investigation of thecarbohydrates, and the long series of researches by Purdie, Irvine,and other workers in the St. Andrews school on the simpler hexosesand their methylated derivatives have paved the way to an under-standing of the constitution of some of the more complex membersof this group of compounds. The general prockdure of fullymethylating the complex compound by means of methyl sulphatt:and sodium hydroxide, followed by methyl iodide and silver oxide,and then of hydrolysing the methylated compounds in which thehydroxyl groups are thus protected, has in several instances provedvery successful, inasmuch as the properties of the methylatedhexoses which are obtained on hydrolysis are fairly well known.This method is being widely adopted by other workers, and yieldsmore certain results than the investigation of the acyl derivatives39 Proc.Roy. SOC., 1921, [ A ] , 99, 163; A., i, 389.4O T., 1920,117, 1501 ; 1921,119, 225.4 1 Ibid., 1919, 115, 1050; 1920, 117, 1280.42 Ibid., 1921, 119, 1280.D74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the sugars43 or the acetolysis44 of polysaccharides by acetylbromide in the presence of hydrogen bromide and acetic acid, acomplex reagent which brings about simultaneous acetylation,hydrolysis, and bromination.Haworth and Hirst 45 have fullymethylated cellobiose, which they obtain in about 30 per cent.yield from cellulose by an improved method of acetolysis. Thisoctamethyl derivative is shown to be heptarnethylmethylceI10-bioside, and splits up on hydrolysis into known butylene-oxidicforms of tetramethyl and trirnethyl glucose.The formula (I) for cellobiose which Haworth and Miss Leitch467H2*OHVH--O --CH2 I YH-OH C;H*OHp H 1 VH*OHFH*OH I - ~ H ~ O H C;'H*OHCH,*OH C€I,*OH LCH*OHr$'H--O--YH(, FH*OHrZZ.OHyH*OH oYH*OHLYH I YH-QH '-?H 01 1 YH*OH(1.) (11.1suggested during their research on maltose (11) has thus beenconfirmed.The .constitution of gl~cal,*~ which was discussed in last year'sReport, has been fully proved and compounds of the type of glucal,other sugars.The names Gf these, such as rhamnal, lactal, cellobial,etc., have lost their significance as the compounds, when pure,have no aldehydic properties. Glucal itself is oxidised by perbenz-oic acid to anhydromannose, which, with alcohol and water,yields rnannose and ethylmannoside.Analogous results have been obtained with rh amnal and cellobial,which incidentally confirm Haworth's formula for ccllobiose.It will be recalled that last year Irvine and Soutar48 showedthat the yield of pure glucose obtainable from cotton cellulose was,as a minimum, 85 per cent. of the theoretical amount calculatedon the basis of the equation (CSHIOO5), + nH,O = nC,H1,O,.Further work by Monier-Williams 49 has increased the yield ofcrystalline glucose to more than 90 per cent.and affords strong,although not conclusive, evidence that the molecular unit of un-modified cellulose consists entirely of condensed glucose residues.43 K. Hess and 11:. Mcssmer, Ber., 1921, 54, [B], 499 ; L4., i, 303.4* M. Bergmaiin and P. Rock, ibid., 1674; A . , i, 649.4 6 T., 1921, 119, 193. 4 G Ibicl.;1919, 115, 808.*' M. Bergmanii and H. Schotte, B e T . , 1921, 54, [B], 440; A., i, 307.48 T., 1920, 117, 1489. 49 Ibid., 1921, 119, 803ORGANIC CHEMISTRY. 75It has been known for some years that when cellulose or starchis subjected to dry distillation under reduced pressure a well-defined, crystalline compound can be isolated. This was termed byPictet, its discoverer, Z-glucosan, and he has argued 5O that theformula of this anhydro-glucose must afford a clue to the constitu-tion of cellulose and starch, on the assumption that these arepolymerides of l-glucosan.Now W-. X. Denham 51 has shownthat the limit of methylation of cellulose is practically that requiredfor the f orination of trimethyl cellulose, which gives on hydrolysisthe same trimethyl glucose isolated by Haworth and Hirst 5? fromthe products of hydrolysis of methylated cellobiose.The importance, therefore, of ascertaining the constitution ofZ-glucosan is apparent, and Irvine and Oldham 53 have been success-ful in converting it into a trimethyl glucose identical with thatobtained previously from methylglucoside and from maltose, andquite distinct from that obtained (as described above) in two waysfrom cellulose.It is, however, scarcely a matter of surprise that,considering the complex changes undergone by carbohydrates onheating, the constitution of Z-glucosan bears no structural relationto that of cellulose. In fact, i t has thus been proved that l-glucosanis 1 : 6-P-glucose anhydride, and would be designated more correctlyas p-glucosan.bI'0Some progress can be recorded in the elucidation of the con-stitution of starch and the first products of its hydrolysis. Thecrystalline dextrins first obtained by Schardinger 54 in 1903 by theaction of certain bacteria (notably Bacillus maceram) were investi-gated by Pringsheim 55 and characterised as diamylose (C6H1005)2,triamylose, tetra-amylose, hexa- and octa-amylose, the molecula,rweights of the acetyl derivatives of these being determined inseveral solvents.These compounds have been recently investi-gated further by Karrer j6 and his co-workers, who have subjectedthem to the action of acetyl bromide and acetic acid. I n this way,so Inter alia, Helv. Chim. Acta, 1918, 1, 187.51 T., 1921, 119, 77. 5 2 loc. cit. 53 T., 1921, 119, 1744.54 Zeit. Nahr. Genussm., 1903, 6, 865; A., 1904, ii, 67.5 5 Ber., 1913, 46, 2959; A . , 1913, i, 1156.56 Helv. Chiin. Acta, 1921, 4, 169, 678; A . , i, 310, 768.D" 76 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the so-called a-tetra-amylose is converted first into acetylateda-diamylose and then by the opening of the anhydride ring quantita-tively into aceto-bromomaltose. It would thus seem that a-amyloseis the first known anhydride of a disaccharide.The methylation of potato starch has been carried out a€so byK a ~ ~ e r .~ ’ The product obtained by the use of methyl sulphateand baryta water has the empirical formula [C,H,0,(OMe)2], witha molecular weight of about 1100, and can be further methylated bymeans of silver oxide and methyl iodide, giving a methylostarchhaving a molecular weight in water of about 1200. Solutions ofthe methylated starch in water or chloroform exhibit the Tyndalleffect and under the ultramicroscope show colloidal particles.The aqueous solutions, however, readily undergo ultrafiltrationwith little loss, and the filtrates appear optically empty and presentno Tyndall effect.The size of the starch molecule has not yet beendetermined and it appears certain that it is much smaller than hasbeen freely suggested by the older workers.Nitrogen Compounds.It has Been known for some time that an aldehyde in the presenceof ammonia can be oxidised to the amide of the corresponding acid.Mignonac 58 has now shown that alcoholic solutions of aldehydesand ketones can be reduced by hydrogen in the presence of a nickelcatalyst to the corresponding amine in accordance with the generalscheme, R-CHO + NR, -+ R*CH(OH)*NH, --+ R*CH,*NH,. Thereaction appears to be general and possesses the advantage overother methods for the preparation of primary amines in that thereis no simultaneous formation of secondary and tertiary amines.The reaction between secondary bases, formaldehyde, and alcoholsor mercaptans has been studied by C. 31.McLeod and Mrs. G . M.Robinson.59 These authors show that the reaction NHR, +CH,O + R’OH(or R’SH) -> R,N*CH,*OR’ + H,O is quite general ;the resulting dialkylaminomethyl alkyl ethers and sulphides, whichare best obtained by condensing the components in the cold inthe presence of an excess of potassium carbonate, are mobile oilswhich distil without decomposition. The thio-ethers are morestable than the ethers, but all are more or less readily hydrolysedby water and acids.Up to the present, methods for the reduction of amino-acids57 Helv. C h i m Acta, 1920, 3, 620; A., 1920, i, 820; ibid., 1921, 4, 185,68 Compt.rend., 1921, 172, 223; A., i, 165. %;s T., 1921, 119, 1470.263; A., i, 311, 313ORGANIC CHEMISTRY. 77with primary amino-groups to the corresponding amino-alcoholshave not been available. It has now, however, been found 60 thatthe well-known method of Bouveault and Blanc, in which an esteris reduced with sodium and alcohol, gives, if applied to the acetylatedesters of the amino-acids, good yields of the corresponding amino-alcohols. Most of the amino-alcohols thus obtained are nowdescribed for the first time and appear to be of considerablephysiological interest.Whilst the substitution of the imino-hydrogen in " saccharin "by alkyl groups entirely destroys the sweetness of that substance,the position is completely reversed in the case of diglycollimide,61which, although itself tasteless, yields alkylimides of the generalformula 0 ,cH-.co >NR, which increase in sweetness with anincreasing number of carbon atoms up to a maximum in the N -propyl derivative.The aryl derivatives, on the other hand, arealmost tasteless. These cyclic imide-ethers of diglycollic acid arevery hygroscopic and are of little practical importance as sweeteningagents, as they are slowly hydrolysed by the absorbed water to thecorresponding akylamine hydrogen diglycollates./CH G OROBERT H. PICKARD.PART II.-HOMOCPCLIC DIVISION.Reactions.lCecluclion.-It is reiuatrkaI,le that the catalytic hydrogenation ofwtrifluorotoluene, Ph*CF,, should lead exclusively to the productionof trifluoromethylcycZohexane, whilst under similar conditionscc-difluorotoluene yields difluoromethylcyclohexane together with asmall proportmion of methylcyclohexane. This stability oE fluorinein a side chain towards molecular hydrogen in presence of platinumblack is in sharp contrast to the ready removal of the same substi-tuent when attached to the aromatic nucleus, since p-fluorobenzoicacid gives first benzoic acid and then cyclohexanecarboxylic acid.Ethyl a-naphthoate is reduced by sodium and alcohol to a methyl-dihydronaphthalene,2 and this reaction recalls the fact that saturatedacids can occasionally be reduced to hydrocarbons containing thesame number of carbon atoms by means of hyhiodic acid and6o P.Karrer, W. Karrer, H. Thomann, E. Horlacher, and W.Miider,Helv. Chim. Acta, 1921, 4, 76; A., i, 228.M. Sido, Ber. deut. Pharm.Ges., 1921, 31, 11s; A . , i, 447.F. Swarts, Bull. Acad. my. Belg., 1920, 399; A., i, 657.H. de Pornrnereau, Compt. rend., 1921,172, 1503; A., 1921, i, 56778 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.phosphorus. Undecane, for example, may be obtained in thismanner from undecoic acid.3 A device likely to prove useful inmany cases is that employed for the reduction of nitropiperonal,which can be effected if the aldehyde group is first protected bycondensation with p-toluidine and the reduction performed inaqueous alcoholic solution by means, of sodium sulphide. Thearninoazomethine derivative obtained in this way is then readilyhydrolysed by hot water.4 An important addition to the methodsavailable for the preparation of arylhydroxylamines consists in thereduction of nitro-compounds in emulsified suspension by meansof sodium ~ulphide.~ The process is a modification of that ofWillstattcr and Kubliy6 and the essential novel features are thereplacement of ammonium sulphide by sodium sulphide, the em-ployment of aqueous instead of alcoholic solutions,* and the pro-duction of an emulsion, facilitated by the addition of small amountsof calcium chloride.Oxidation.-The behaviour of sodium phenoxide at 485490'in an atmosphere of hydrogen or nitrogen has been examined'and the products are hydrogen, methane or ethane, benzene,diphenyl, diphenyl oxide, 2-hydroxydiphenyl, and larger relativeamounts of four dihydroxydiphenyls (2 : 2'-, 3 : 3'-y 3 : 4'-y andprobably 2 : 3'-).Novel results have been obtained in an extensive study of theaction of hydrogen peroxide in alkaline solution on unsaturatedketones.8 I n most cases, the product is an ethylene oxide derivativecontaining one atom of oxygen more than the original ketone.Thus st-yryl methyl ketone yields P-acetyl-a-phenylethylene oxide(I), m. p.52-53', together with a liquid isomeride, and the nature ofthese substances is placed beyond doubt by the fact that the corre-sponding compound (11) from phenyl styryl ketone is identical withthe product obtained by Widman by the action of benzaldehyde onO- bromoacetophenone.These oxides liberat,e iodine from potassium iodide and aceticacid with regeneration of the unsaturated ketone, and the compound3 Krafft, Ber., 1882, 15, 1697.4 A.Rilliet and L. Kreitmann, Helv. Chirn. Acta, 1921, 4, 588; A . , i, 567.5 A. Lapworth and (Mrs.) L. K. Pearson, T'., 1921, 119, 765, 768.7 F. Hofmann and M. Heyn, Brennsto#-C'hem., 1921, 2, 147 ; A . , i, 506.8 E. Weitz and A. Scheffer, Ber., 1921, 54, [B], 2344; A., i, 869; ibid.,9 il., 1913, i, 1220.Ber., 1908, 41, 1936.232'7 ; A., j , 868ORGANIC CHEMISTRY. 79(I) is transformed by hydrogen chloride in acetic acid into an oilychlorohydrin which slowly liberates hydrogen chloride, with forma-tion of hydroxymethylenebenzyl methyl ketone, OH*CH:CPh*COMe.Halogenation.-A comparison lo of the activity of catalysts in thechlorination of benzene by sulphuryl cliloride has shown thatanhydrous aluminium chloride is by far the most efficient, the yieldof monochlorobenzene amounting to nearly 90 per cent.of the theoryin some experiments.It is, perhaps, a little remarkable that the dibromination ofethylbenzene should lead to ct p -dibromoe thylbenzene, which , bythe action of magnesium, is converted into styrene.Etherification and Esterijication.-The very useful process ofetherification of phenols by means of arylsulphonic esters has beenexamined in detail so as to determine the optimal conditions,12and workers who have occasion to alkylate phenolic bases especiallyshould make themselves familiar with the results. The preparationof many benzyl derivatives, benzyl esters, ethers, phenylaceto-nitrile, benzylamines, etc., is found to proceed in aqueous solutionso as to give far higher yields than those obtained in other ways.13Replacement of Xubstituents in Aromatic Compounds.-Improve-ments have been made in the already numerous processes for thereplacement of halogen in benzene and naphthalene derivatives byhydr0xyl.1~ It is found that the salt of a weak acid can often replacethe alkali usually employed; thus an 83 per cent.yield of salicylicacid is obtained when potassium o-chlorobenzoate is heated withwater, sodium acetate, and a trace of cupric acetate a t 140-150".Partly successful attempts have been made to apply similar re-actions to the replacement of halogens by sulphur and selenium andby the sulphonic and arsinic acid groups.ThionbenxoyZ Derivatives.-The only known substance containingthe group *CSCl is thiocarbonyl chloride, and special interestattaches, therefore, to the preparation l5 of thionbenzoyl chloride,PhCSC1, which may be obtained as a reddish-violet, mobile liquid,b.p. 60-62"/0.2 mm., of disagreeable odour, by the action ofthionyl chloride on dithiobenzoic acid. The substance behaves asa true acid chloride, yielding an anilide and methyl thionbenzoate,Ph*CS*OMe, by the action of aniline and methyl alcohol respectively.For comparison, the isomeric methyl thiobenzoate, Ph*CO*SMe,was prepared from benzoyl chloride and methyl mercaptan. Thion-lo 0. Silberrad, T., 1921, 119, 2029.11 J. voii Eraun and K. Moldanlre, Bcr., 1921, 54, [BJ, 618; A ., i, 403.l2 Z. E'Olcli, Ber., 1920, 53, [B], 1839; L4., 1920, i, 5'17.13 M. Gomberg and C. C. Buchler, J . A7IZP1'. Chem. Soc., 1920, 42, 2069;1 4 K. W. Rosenmund and H. Harms, Ber., 1920, 53, [BJ, 2226; A., i, 103.1s H. Staudingcr and J. Siegwart, NeZv. Chim. Acta, 1920, 3, 824; A., i, 25.A., 1920, i, 83980 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.benzoyl chloride yields benzoyl chloride and rnonoclihic sulphurwhen heated a t 110-120” in a current of oxygen.Diaxonium Salts.-The researches of Meldola and others havemade us familiar with the fact that a diazo-group has a looseningeffect on ortho-substituents, and that this property is much en-hanced when there is a positive l6 group situa,ted in the ortho- orpara-position with respect to the affected radicle.Thus thediazotisation of dinitroanilines (NH, : NO, : NO, = 1 : 2 : 3 or 1 : 2 : 5 )frequently leads to the formation of diazo-oxides. Numerousmethods have been suggested with the object of avoiding thisdifficulty, and the latest device,17 which apparently works well, isto diazotise the feeble base in acetic acid solution a t a low tempera-ture with a solution of sodium nitrite in sulphuric acid monohydrate.Even 2 : 4 : 6-trinitroaniline can be dia,zotised and 2 : 4 : 6-trinitro-m-phenylenediamine tetrazotised by this method. The 2 : 4 : 6-trinitrobenzenediazonium salt is unusually reactive and coupleswith mesitylene to form 2 : 4 : 6-trinitrobenzeneazomesitylene,C,H,(N02),*N,*C,H,Me,,18 which may be reduced to mesidine.A curious reaction which may be employed h r the preparationof the arylsulphinic acids and aromatic azoimides occurs when, forexample, benzenediazonium chloride is allowed to react with analkaline solution of p-toluenesulphonamide. l9 The process is afairly general one, results in high yields, and may be carried out inaccordance with either of the equations (1) or (2) :R*SO,*NH, + 2R’N,C1= R.SO,*N,*R’ + R‘N, + 2HC1 .(2)R*S02*NH2 + R’N,Cl= R*S02H + R’N3 + HC1 . . . (1)Hydraxine Derivatives.-Sodium hyposulphite gives excellent;results in the reduction of diazo-salts, and p-nitrophenylhydrazinemay be prepared in this way from p-nitroaniline in a yield amount-ing to 95 per cent. of the theoretical.20 The action of azodicarb-oxylic ester on p-naphthylamine leads to the production of 2-amino- 1 -dicarbethoxyhydrazinonaphthalene,21N(CO,Et)*NH*CO,Et\/\/l6 By this term are implied the groups like -NO2, -CO,H, -SQ,H, etc.,usually called negative.Their true character as positive groups has inrecent years been emphasised by Fry, Lapworth, Vorliinder, and others.It is true that such groups have a negative effect on the atom to which theyare united.E. Misslin, Helv. Chim. Acta, 1920, 3, 626; A., 1920, i, 887.K. H. Meyer and H. Tochtermann, Ber., 1921, 54, [ B ] , 2283; A., i, 895.l9 P. K. Dutt, H. R. Whitehead, and A. Wormall, T., 1921,119, 2088.2o L. Thomson, J . Xoc. Dyer8 and Cot., 1921, 37, 7; A., i, 133.2 1 0. Diels, Ber., 1921, 54, [B], 213; A., i, 280ORGANIC CHEMISTRY.81Condensations.-The condensation of acetylene with benzene inpresence of aluminium chloride gives aa-diphenylethane and 9 : 10-dimethylant hracene hydride in approximately equal proportions,along with traces of styrene.22 Toluene gives as-di-p-tolylethane,2 : 7-dimetlhylanthracene, and smaller relative amounts of 2 : 6-dimethylanthracene, p-methylanthracene, xylene, mesit,ylene, and+-cumene. Chlorobenzene gives as chief product di-p-chloro-s-diphenylethane, C6H4C1*CH2*CH,*c6H4cl.Nitriles are increasingly employed for the synthesis of phenolicketones, and a whole series of acyl resorcinols and phloroglucinolshas been prepared23 by condensing the phenols with aliphaticnitriles according to the method devised by Hoesch.24 Thesesubstances are remedies against the tape-worm ; the resorcinolderivatives are as useful as those derived from phloroglucinol, andthe most valuable acid residue appears to be isohexoyl.A mixtureof cyanogen and hydrogen chloride reacts as the dichlorodi-irnideof oxalic acid, and with resorcinol in ethereal solution condenses toproducts which yield resorcylglyoxylic acid, C6H3( OH),=CO*CO,H,and 2 : 4 : 2' : 4'-tetrahydroxybenzil, C6H3(0H),*CO=C0.C6H,(OH)2,along with other substances on hydr0lysis.~5 Orcinol gives onlythe glyoxylic acid derivative.Benza'nilideiminochloride and its derivatives substituted in thenucleus condense readily with resorcinol, apparently in accordancewith the scheme :-C6H4( OH), + CPhC1:NBh + C6H,( OH)*O*CPh:NPh + HC1k'C,H3( OH),*CPh:NPh.Thc first reaction occurs a t 100" and the isomeric change a t about150°, the final productl being readily hydrolysed by dilute hydro-chloric acid with formation of benzoresorcinol.26 This process isanalogous to Hoesch's synthesis and also to Dimroth's preparationof P-resorcylaldehyde by the hydrolysis of the anilide resulting fromthe interaction of resorcinol, formanilide, and phosphoryl chloridein ethereal sol~tion.~' The latter method has now been appliedwith good results to the preparation of alkylaminobenzophenones,replacing the resorcinol by a tertiary amine and the formanilide bya benzanilide.28 The substances formerly described by other22 0.W. Cook and V. J. Chambers, J . Amer. Chem. SOC., 1921, 43, 33%;A . , i, 332.23 P.Karrer and S. Rosenfeld, Helv. Chim. Acta, 1921, 4, 707; A., i, 793.24 Ber., 1915, 48, 1122.2 5 P. Karrer and J. Ferla, Helv. Chim. Acta, 1921, 4, 203; A., i, 341.2 6 H. Stephen, T., 1920,117, 1529.2 7 Dimroth, Zoppritz, Ber., 1902, 35, 995.28 J. Meisenheimer, E. von Budkewicz, and G. Kananow, Annalen, 1921,423, 75; A., i, 35682 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.authors as dialkylaminobenzophenones are actually benzanilides.Dimethylaminobenzophenone has been employed for the prepara-tion of leucotriphenylmethane dyes of the type RR,R,CH in thehope of resolving some member of the class and determining thequestion of the survival or disappearance of optical activity afteroxidation and subsequent reduction. Racemisation is certainlyto be anticipated.The Transformations of Ary1hydroxylamines.--It is impossibleadequately to discuss in this Report the voluminous experimentalwork of Bamberger 29 on this subject, but some reference a t least isnecessary to the careful comparison drawn between the behaviourof an arylhydroxylamine and the corresponding arylazide towardssulphuric acid under various conditions.The results are closelyparallel with the significant exception that azoxy-compounds,frequently obtained from the hydroxylamines, are never producedfrom the azides. This disposes of the suggestion which has beenput forward 30 that the parallelism is due to preliminary conversionof the azide into the hydroxylamine by loss of nitrogen and hydra-tion. Bamberger considers that the transformations are bestexplained by the formation of an arylimide, Ar--N<, from thehydroxylamine by loss of water and from the azide by loss ofnitrogen.The formation of aminophenol then occurs as follows :-One further example may be illustrated, the conversion of rn-xylylazide into 2-amino-p-5-xylenol :-Of the numerous further reactions, reduction leads to anilinederivatives and hydrolysis to dihydroxybenzenes, reduction andhydrolysis to phenol derivatives. The arylimide may also add onz9 J. pr. Chern., 1921, [ii], 102, 267; A., i, 716; Anwalen, 1921, 424, 233;3O Friedlander and Zeitlin, A . , 1894, i, 184.A., i, 716; ibid., 297; A., i, 723ORGANIC CHEMISTRY. 83an alcohol, resulting in the production of phenolic ethers.Thesomewhat more complex problem of the changes induced by halogenacids is also discussed.Substitution and Orientation.The nitration of benzotrichloride to m-nitrobenzotrichloride wasreferred to in the Report for the year 1919, and it is now found thatthe very stable w-trifluorotoluene also yields on nitration them-nitro-derivative as chief product.31 These results are in agree-ment with the principle of induced latent polarity of atoms in achain which was also discussed in the Report for the year 1919.The examination 32 of the nitration and chlorination of Z-chloro-p-t,oluenesulphonyl chloride has given results which may be sum-marised in the scheme :-Me Meq c 1NO,!,S0,ClMe' Cli/)Cl\/S0,ClMef)Cl\/S0,ClNO2()Cl\/SO2C1Me/)Cl % S0,ClThis may be compared with the behaviour of 4-nitroveratrole :-Br--+ n l e d ) MeO/')NO, ~ MeO/\ JMeO!,,NO, MeO!,/NO, MeO(,N02There is evidently a general tendency for the entrance of halogento be definitely directed by positive groups to the meta-positionto a greater extent than is the case when the entering substituentis nitroxyl.The effect of chloro- and nitro-groups on the mobility of othersimilar substituents has been exhaustively investigated by Holle-mann and his col1a)borators 33 in the case of the dichlorodinitro-31 F.Swarts, Bull. Acud. roy. Belg., 1920, 389; A., i, 656.32 W. navies, T., 1921, 119, 853.33 A. F. Hollemann, A. I. den Hollander, and F. E. van Halften, Rec. truv.chim., 1921, 40, 323; A ., i, 503; A. F. Hollemann and F. E. van Haeften,ibid., 67; A., i, 167; E. J. E. Huffer, ibid., 451; A., i, 549; A. F. Holle-mann, Rec. trav. chim., 1920, 39, 736; A , , i, 10284 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.benzeners, the six trichloronitro benzenes, the six trichl~rodinitro-benzenes, the three tetrachlorobenzenes, pentachlorobenzene, andhexachlorobenzene. In general, the results obtained in studyingthe action of sodium methoxide are in harniony with previousexperience, although some novel features are brought to light.Most interesting is the fact that the reactivity of a chlorine atomis enhanced by the entrance of a second chlorine atom in the meta-position. It will be recalled that Wieland and Sakellarios34showed that ethylene is capable of nitration to p-nitroethyl nitrateand, in correcting an earlier publication relating to the action ofnitric acid on aa-diphenylethylene, Anschiitz 35 discloses theinteresting fact that Kekuld had in 1877 reached the opinion thatnitroethyl nitrate is the product of the action of nitric acid onethylene.The course of the nitration of diphenylethylene inglacial acetic acid solution is shown in the scheme :-CPh,:CH, +mO> HO*CPh,*CH,*NO, 2~; CPh2:CH*N0,CPh,:CH*NO, -tmO> HO*CPh,*CH(NO,), 2!+ CPh2:C(N02),111, IV, and V are isolated and the latter undergoes reduction inthe following manner :-(111.) ( IV. 1(V. )CPh2:C(N02), --+ CPh,:C( NH,), + CYh2:C:NH -+ CHPh,.CN.The nitration of ethylene derivatives has also been studied byWieland 36 in continuation of his comprehensive researches. Thesubstance (111) above is obtained by the action of a solution ofabsolute nitric acid in carbon tetrachloride on diphenylethylene a t- 10".In some cases the primary product cannot be isolated,thus the action of nitric acid on P-methyl-As-butylene: CMe,:CHMe,leads immediately to the nitro-derivative, CMe,:CMe*NO,, mixedwith some nitroisoamyl nitrate.These observations are, of course, extremely instructive in rela-tion to the mechanism of substitution in aromatic compounds whichby analogy are due to reactions of addition and fission. During thepast year Kurt H. Meyer has emphasised the addition theory ofdiazo-coupling37 and his views will meet with general support inmost respects, but he appears to think that the gap in auxochromicor activating power existing between Me and OMe involves nonecessity for a special explanation.Nevertheless, the existence of34 A., 1920, i, 280.35 Anschutz and Hilbert, Ber., 1921, 54, [BJ, 1854; A., i, 783.36 H. Wieland and F. Rehn, ibid., 1770; A . , i, 782.3' Ibid., 2265; A , , i, 855ORGANIC CHEMISTRY. 85conjugated ethylene-nitrogen and ethylene-oxygen systems canscarcely be disputed, and Meyer does not dispose of or even con-template the possibility that the unsaturated system in phenolsand amines includes the oxygen or nitrogen at0ms.~8 This would,after all, be a inere extension of the assumption already made inorder to explain ortho- and para-substitution by reference to thelength of the unsaturated chain to which addition occurs.Geometrical Isomerism.A third monobromostyrene has been prepared,39 and the isomer-ides are obtained by the following methods.(A), m. p. 6-7", byheating sodium dibromo- p-phenylpropionate with an aqueous solu-tion of sodium carbonate ; (B), m. p. - 43", by the action of hydrogenbromide on phenylacetylene; (C), m. p. - 8 t'o - 7', by heatingphenyl bromostyryl ketone, CHPh:CBr*COPh, with powderedsodium hydroxide. A and C (the new isomeride) both give app-tri-bromoethylbenzene on bromination, whereas B gives aap-tribromo-ethylbenzene. A and C are therefore stereoisomerides of the formulaCHPhXHBr. Auto-oxidation of the substance B yields w-bromo-acetophenone as the result of an intramolecular rearrangement .40The two w-bromostyrenes are very sensitive to light and either aloneor mixed are converted to a substance or mixture with a constantmelting point of 2°.41Gentle isomerisation of safrole, CH,02:C,H3*CH2*CH:CH2, bymeans of dilute alcoholic potassium hydroxide at 82-86' producesa new unstable cis-isosafrole, CH20,:C6H3*CH:CH*CH3, readilytransformed by alkali at a higher temperature into the known trans-modification .42 The isomerides can be interconverted through theirdibromides and relatled monobromoisosafroles, the latter yieldingthe isosafroles on reduction with zinc and ethyl alcohol.It isstated that the isosafrole dibromides are optically active, but thismust surely be an error, especially since safrole is always isolatedfrom essential oils containing active constituents.Formylphenylacetanilide, prepared from phenylacetanilide andformic ester by the act'ion of sodium wire in ethereal suspension,has been isolatedB in two forms, m.p. 68' and m. p. 98', whichare apparently not desrnotropic, but the geometrical isomerides38 Since writing the above, a paper in the December number of the Beukhtehas been consulted, in which Auwers criticises the views of Meyer and pointsout that physical data strongly support the hypothesis of the existence inphenols of conjugated systems which include the oxygen atom.39 C. Dufraisse, Compt. rend., 1920, 171, 960; A., i, l i .4'J Idem, ibid., 1921, 1'72, 162; A., j, 168. J 1 Idem, <bid., 6 7 ; A., i, 104.42 Shoichiro Nagai, J.Coll. Eng. Tokyo, 1921, 11, 8 3 ; A., i, 857.43 W. Widicenus and R. Erbe, Annalen, 1920, 431, 119; A., 1920, i, 84186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the enol modificatlion, HO*CH:CPh*CO*NHPh. The relaiiedpipcridides have also been prepared and exhibit a similar behaviour.The formulae VI and VII for saturated dimerides of cinnamicacid allow for the existence of eleven isomerides, five correspondingwith VI and six with VII.The isolation of a, seventh truxillic acid44 proves for, the firsttime that these substances belong to both series depicted. It isproposed to term the dimerides of trans-cinnamic acid truxillic acidsas formerly, and for those derived from cis-cinnamic acid the nametruxinic acids is adopted.P-Truxinic acid, which itself resultsfrom the illumination of cis-cinnamic acid, yields the new isomeride,neotruxinic acid, by the prolonged action of aqueous pyridine a t160-170". The acid has also been found to occur in small amountamong the truxillic acids obtained during the preparation ofcocaine.In the tetrahydronaphthalene series, the method of condensationwith acetone is found to distinguish between cis- and trans-diols,only the former giving dioxymethylene derivatives.45 Neverthe-less, the diagnostic value of the reaction has its limits, since bothcis- and trans- P : 2-cycloheptanediols yield isopropylidene ethers.46The oxidation of cycloheptene by means of potassium permanganateand magnesium sulphate yields cis-1 : 2-cycloheptanediol, m.p.46", whilst the trans-compound, m. p. 63", is obtained by the useof peroxybenzoic acid in chloroform solution followed by the actionof dilute hydrochloric acid. An ingenious and novel device hasbeen evolved 47 in order to determine the configurations of the twoam'-dibromoadipic acids, C0,H*CHIBr*CH2*CH,~CHBr*COzH, m. p.'s193" and 139". The method is probably of general applicability,and depends on the replacement of the bromine atoms by a bivalentgroup so as to produce a ring. The product typified by the expres-sion VIII will be obtained in the cis- or trans-modification accordingas tthe starting point is respectively the meso- or racemic form ofthe dibromo-acid, and if RH, is a symmetrical molecule, only the44 R.Stoermer and E. Laage, Ber., 1921,54, [B], 7 7 ; A . , i, 179; R. Stoermerand F. Scholtz, ibid., 85; A., i, 180; R. Stoermer and E. Laage, ibid., 96;A., i, 182.4 5 J. Boeseken and H. G. Derx, Rec. trav. chim., 1921, 40, 519; A . , i, 663-4 G Idem, ibid., 529; A., i, 663. *' W. H. Perkin and E. Robinson, T., 1921, 119, 1392ORGSNIC C.HEMISTRY. 87trans-modification will be resolvable into optically active components,CH,*CH*CQ,HCH,*CH*C02HThe diethyl ester of the dibromoadipic adid, m. p. 193", is areadily purified solid and condenses with the sodium derivativeof malonic ester to a tetracarboxylic ester which by the usualprocesses yields cyclopentane-l : 2 : 3-tricarboxylic acid. Thissubstance could be resolved with the aid of brucine, and the acid,m.p. 193", is therefore the raceinic niodificatioii of dibromoadipicacid. In order to make the argument clear, all possible configura-tions of the c~cZopeiit~anetric,zrboxylic acid are given below :I >R (VIII).X is the mirror image of IX, whilst XI and XI1 have superposablemirror images. Consequently, the acid obtained as described aboveis the inactive mixture of IX and X, and reference to the modelswill show that these configurations are directly related to those ofdextro- and l ~ v o - ax'-dibromoadipic acid.The existence of a peculiar form of isomerism in the diphenylseries, exemplified a t present only in the case of the two oo-dinitro-benzidines and their deri~atives,4~ has been confirmed by the isola-tion of two 6 : 6'-dinitrodiphenic acids.49 The first isomeride, in.p.297" or 303", was already known and was obtained by Xchulze 504R J. C. Cain, A. Coulthard, and (Miss) F. M. G. Micklethwait, T., 1912,101, 2298; ibid., 1913,103, 2074; J. C. Cain and (Miss) F. M. G. Micklethwait,ibid., 1914, 105, 1437, 1442.49 J. Kenner and W. V. Stubbings, ibid., 1921, 119, 593.50 Annalen, 1880, 203, 9588 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.as one of the products of the nitration of diphenic acid as also bythe oxidation of the mixture of dinitrophenanthraquinones. Ityields a diamino-acid on reduction, and may be converted into2 : Z'-dinitrodiphenyl or into carbazole. Further details of informa-tion in regard to this acid will be welcomed. The new isomeride,m. p.263", is obtained as an est3er, in accordance with the scheme :-C0,R2 /-\I \-/NO2Cu powder + --C0,R NO,NO, CO,R/--\ /-\\-/ \-/The behaviour of the acid on reduction is in sharp contrast withthat of Schulze's substance, since a dilactam (XIII) is the soleproduct.CO-NH//-\ i-\\-/ \-/(XIII.)\ N H ~ OThe suggestion is, therefore, that the subst'ances atre stereoiso-C0,H C0,W CO,H NO,NO, NO, NO, CO,HThe assignment of these formule is made on the basis of thering formation already referred to, but as an additional argumentin favour of their correctness it should be noted that the particularmethods of formation of the isomerides might be expected to leadto the observed results. The opening of the phenanthrene ringnaturally leaves the carboxyl groups in something analogous to acis-position, whilst the repulsion of similar groups accounts for theproduction of a substance possessing a trans-spatial character.A fourth benzildioxime may be obtained by the addition ofammonium chloride to a solution of a- benzildioxime in aqueoussodium hydroxide which has been allowed to remain during twohours.51 6-Benzildioxime melts at 220" and is rapidly convertedin alcoholic solution by acids or ammonia into the a-isomeride(m.p. 237"). It is characterised by the formation of a buff-colourednickel compound, which passes with facility into the red nickelcompound of a-benzildioxime and is thus differentiated from themerides of the annexed configurations :/-\ /--\ /-\ /-\\-/-\-/ \-/ \-/Schdze's acid.Kenner and Stubbings's acid.61 F. W. Atack and L. Whinyates, T., 1921,119, 1184ORGANIC CHEMISTRY. 89similar nickel compound of 7-benzildioxime. The constitution ofthis interesting substance has not yet been fully elucidated, but itsexistence cannot be explained by the conventional Hantzsch-Werner hypothesis unless this be extended by the admission of thepossible existence of structural isomerides. Atack considers 52that the isomerism in the group of the oximes is more probablystructural than geometrical and in a general discussion of thesubject makes out a strong case in support of his thesis. It is not,however, yet possible to regard the problem as solved, although i tis clear that the stereochemical theory in its simplest form isinadequate.Natural Products.A new monocyclic terpene has been found 53 in the oil of Modajaponica, Maxim.Moslene nitrosochloride on treatment withsodium ethoxide yields among other products an azo-compoundidentical with that obtained by the reduction of 2-nitro-p-cymene.From this and other considerations it may be deduced that moslenemust have the constitution (XIV) or (XV)CHMe CHMe\/CI ww P)(XIV. )/\ EH ZH CH CH\/VHLater 54 the terpene was proved to exist in other essential oilscontaining p-cymene.Piperitone, the peppermint ketone of eucalyptus oils, has beeninvestigated and characterieed by numerous derivatives. It hasthe formula CloHl,O 55 and may be oxidised to thymol by ferricchloride or catalytically reduced to menthone. Another paper 56deals with its characteristic benzylidene and other derivatives andcontains a brief account of the relation of the occurrence of piperi-tone to the botanical characters of the genus Eucalyptus and to theot’her oil constituents.The oil from the grass Andropogon Jwarancusa, Jones, contains aketone, C,,H,,O, to the extent of about 80 per cent.of the whole,50 T., 1921, 119, 1175.53 Y . Murayaxni-t, J. PhLrttt. ,So(,. .JapCcrL, 1921, 769 ; A ., i, 875.5 4 Idem, ibid., No. 475, 786: A , , i, 875.F,S Smith and Penfold, J . I‘iwc. Roy. SOC. N.S. Jt’dcs, 1920, 54, 40.J. Road and H. G. Smith, T., 1921, 119, 779the identity of which with d-piperitone 57 is considered to be beyonddouLt.58 A conclusive proof is afforded that this grass-oil ketoneis d-Al-p-menthen-3-one (XVI) and its benzylidenc derivat'ive isrepresented by the formula (XVII)Me MeI t! c/\ /\c:H2 co CH, co\ / \- / FHC,H 'i ( P) C3H7PhCH:$l ?€I $!H2 YH(XVI.) (XVII.)'l?herc is of course 110 difficulty in accepting the latter suggestionin view of the well-known fact that unsaturated atoms are efficienttransmitters of the activating influence of a carboxyl group.Theconstitution (XVI) has also been assigned to piperitone fromeucalyptus oil in view of the observation that this substance maybe oxidised to 2-hydroxy-Al-menthen-3-0ne.~~Pikamar, a constituent of beechwood tar, has been synthesised 60by an application of the Claisen transformation and thus shownto be 4-hydroxy-3 : 5-dimethoxy-n-propylbenzene. The synthesisis illustrated in the Lznnexcd schemc :-vdrolvsisOMe LLMe0 J!CH2*CH2*CH,HO/\A crystalline constituent of Siamese benzoin termed lubanylbenzoate is apparently the benzoate of coniferyl alcohol having theconstitution57 Piperitone occurs, however, in an inactive form in eucalyptus oils.58 J.L. Simonsen, T'., 1921, 119; 1644.59 L. Givauclaii & Co., Perf. Essent. Oil Rec., 1921, 12, 80; -4., i, 793.G o P. Mauthncr, J. pr. Che7n., 1921, [ii], 102, 36; 4., i, 726ORGANIC CHEMISTRY. 91but the actual isolation of the alcohol has hitherto proved impossibleon account of its instability to alkali and acid.61The liquors from the sulphite-cellulose process contain a crystallinelactone, C20H2006, which may be obtained by extraction with ether.The constitution XVIII or XIX is suggested for this substance asthe result of a study of its transformations,62OMe CK-1(XVIII.) (XIX.)and of these, XVllI is probably to be preferred in view of theproved structure of guaiaretic acid.The substance is of interest asconstituting another member of the growing class of di-eugenolderivatives.The resin acids have been the subject of several communications,of which a theoretical paper on the constitution of abietic acid maybe mentioned as containing some important suggestions.63 Theformula evolved for abietic acid isa n d this is derived from the Condensation of a molecule of a-pinenewith one of P-pinene followed by oxidation of rz methyl group tocarboxyl.This is a line of argument which is sure to be funda-mentally sound, but the particular interpretation does not squarevery well with the results of other work which now falls to be dis-cussed. 0. Aschan 64 has isolated arid carefully characterised anew crystalline resin acid, pinabietic acid, C20H3002y from the lessvolatile fractions obtained on distilling pine oil in a current ofsuperheated steam. The constitutional investigation conducted by61 A. Zinke and J. Dzrimal, Monatsh., 1920, 41, 423; A.,g, 187; F. Reiri-itzer, Arch. Pharm., 1921, 259, 60; A . , i, 352.62 B. Holmberg, Svensk Kern. Tidskrift, 1920, 32, 56; A., i, 26; Bw.,1921, 54, [B], 2389; A . , i, 849; B. Holmberg and M. Sjoberg, ibid., 2406;A., i, 850.(i3 Ad.Griin, Zeit. Ueut. 01. Felt-ind., 1921, 41, 49; A., j, 344.Annalen, 1921, 424, 117; A., i, 66992 ANNUAL REPORTS ON THE PROGRESS O N CHEMISTRY.A. I. Virtanen 65 has given the following results. Pinabietic acidcontains one double bond (saturated dibromide and dihydro-derivative) and one bridged ring (dihydrobromide).In spite of the fact that the acid can be nitrated and sulphonated,the presence of an aromatic nucleus is improbable on account of theempirical composition, the behaviour towards the reagents for thedouble bond, and also in view of the values obtained for the re-fractive powers of the esters. The latter are difficult to prepare,and also to hydrolyse when once formed.Pinahietyl chloride evolves carbon monoxide and hydrogen whendistilled under reduced pressure and furnishes a hydrocarbon,C19H28, called pinabietene.The latter contains an aromatic nucleusand is octahydromethylretene, since i t may be changed to retene byheating with sulphur, the reaction involving the loss' of hydrogenand a methyl group. Further, the oxidation of pinabietene bynitric acid or by mangaaese dioxide and sulphuric acid producesbenzene-1 : 2 : 4-tricarboxylic acid. The formulze suggested forpinabietene and pinabietic acid are XX and XXI respectively,although i t is admitted that the positions of the double bonds,cross-linking and methyl group marked with an asterisk, are stilldoubtful.CHz CHMe\/CH2(XXI.)But the arguments cited are not a t all conclusive, and that somemodifications may be expected is clear from the fact that the abovestructures cannot be subdivided into units containing the arrange-ment of carbon atoms present in isoprene.This is possible in thecase of all known suhstances of proved constitution which have arelation to the terpene series.The synthesis of siiiapic acid 66 has been effected through thestages :-6 6 Annalen, 1921, 424, 150; A . , i, 609.0 6 E. WpBth, Motmfdi., 1920, 41, 271 ; A ., i, 2ORG.4NTC CH EM1STR-I'. 0 3OMs OMe C)McI -+ HBr HO/\ --?- (:O,Et.O/'MeO(/CO,HMeO/\MeO( \ ,!CO,H MeOl JC0,H///-'\// +------OMe OMe OMeC0,Et-0 /\ CO2Et*O/\jaHo cO,Et*O/)Me01 CH:CH*CO,H -_- MeO(,!COCI H and pnlladi- MeO!,/ -+ Malonic acid k \/dsed BaSO,. and heat.. /---/- 4OMeHO/-\C€I:CH*CO,HSinapic acid.\-/OMCSinapic acid was then converted into sinapin iodide, identical withthe salt of natural sinapin, by condensing acetylsinapoyl chloridewith diniethylaminoethanol to P-dimethylaminoethyl acetylsinapate,which by gentle hydrolysis yielded the corresponding sinapate.The addition of metJhyl iodide now furnished sinapin iodide,Nl\le,I*CH,*CH2.0*CO*CH:CH*C~~~( OMe),*OH, thus confirmingGadamer's formula for sinapin.Alicyclic Group.It is quite impossible owing to limitations of space adequatelyto summarise the work of Thorpe, Ingold, Kon, and others on therelated topics of the conditions governing the ease of formation andthe stability of cyclic systems, and indeed a consideration of thisgroup of papers emphtzsises the desirability of the system of publica-tion from time to time of rdsumds by the original workers themselvesof the position arrived at in the study of their problems.Thetheory that an alteration in the angle subtended by two of thevalencies of a carbon atom involves a corresponding alteration inthat enclosed by the remaining two has been again experimentallyverified.6' It is suggested that " if ZP be the angle formed by thevalencies a and b, the angle 28 between the directions taken up bythe valencies c and d will be determined by the condition that thesedirections are equally inclined to each other and to the direct' Jions6 7 0. Becker and J. F. Thorpe, T., 1920,111, 157994 ,4NNTTAL RFPC)RTS ON TIT13 PROGRICSS Ol? CHEMISTRY.occupied by the vulcncich ( I m c l b.”28 can be calculatcd by riicans of the equationIf 2p is liiio\\-n, it is siio\vii thatCOS 0 = $( I/COS~ p + 8 - cos p).It must be pointed out that the experimental results support thesense of this assumption, but are not as yet capable of being broughtinto any quantitative relation with it.In the seriesMe ,,. /CH*CO,H CH2-C11,\ /CH*CO,HCH2-CH,/ \CH*CO,B Me/ \CH*CO,H’I C t C ICaronic acid. (XXII.)(XXIII.)a and b are taken to be the valencies represented a t the left of thequaternary carbon atom, and we may examine the effect of altera-tions in the angle between a and b by study of t’he stability of thecyclopropane ring. It has already been shown 68 that in the case ofthe cyclohexane derivative XXIII the cyclopropane ring is unusuallystable and resists the action of concentrated hydrochloric acid a t240°, whereas caronic acid is attacked readily and even a t 200” by5 per cent.arid. Here the enlargement of the normal angle betweena and b renders the anglc bet’meen the valencies c and d in (XXIII)smaller without strain and consequently the cycEopropane ring ismore stable. Now the angle in a symmetrical cyczopentane ringdiffers from the normal angle between unstrained carbon valenciesby about 18’ only, and the substance (XXII) should therefore fromthe present point of view closely resemble caronic acid in respect ofthe stability of its cyclopropane ring. This was found to be theease, and the distinction in properties between XXII and XXIII isunexceptionable evidence in favour of the fundamental theory.Other comparisons were instituted with similar results.Progress has been made 69 in the attempt to synthesise spiro-hydrocarbons which on account of their simplicity may be expectedto furnish valuable evidence relating to the nature of valency as itoccurs in carbon compounds.Up to the present, the dihydroresorcinol derivatives (XXIV)and (XXV) have been prepared by the addition of ethyl sodio-malonate to the unsaturated ketones (XXVI) and (XXVII)followed by hydrolysis of the products. The success of this processB R C.K. Ingold and J. F. Thorp, T., 1919, 115, 320.c9 W. S. G. P. Norris and J . F. T h o r p , ihid., 1921, 119, 1109puvus t hatg the condensation prodiict of cyclohextuione aiitl ~~cetonchas the constitution figured (XXVI), and not that (XXVIlI)ascribed to i t by Wallach on the ground of optical properties.The substance is a true analogue of mesityl oxide, and it is remark-able that it does not exhibit the usual exaltation of refractive powerassociated with endocyclic compounds and with ap-unsaturatedketones.CH,*CH, CH,*CO FH,*CH, CH,*COCH,<CH,.CH,>C<CH,~CO>CH, CH,-CH, >C<CHiC0>cEr2(XXIV.) (XXV.)CH,*CH, $'H,*CHCH2' CH2*CH, >C:C€I*COMe CH,.CH, 2 > ~ : ~ ~ * ~ ~ (XXVI. ) (XXVII.)(XXVIII. )Another incidental result of the work under discussion is thedisposal of Vorlander's somewhat bizarre conception that thedibromo-derivative of dimethyldihydroresorcinol should be f ormu-lated as a bromoxy-compound (XXIX). The bromination andsubsequent chlorination and vice versa of dimethyldihydroresorcinolyield one and the same substance, which has accordingly theconstitution (XXX).The ready elimination by means of alkali of one halogen atomfrom these and similar substances in the form of a hypobromite isreferred to the general tendency to acquire a hydrogen atomnecessary for taut'omerism. The pronounced electroposit'ivity ofbromine in a-bromo-ketones is, however, a very general phenomenon,and is exhibited in cases such as ethyl bromoacetoacetate where thepossibility of tautomerism already exists.The polar character ofthe bromine follows from the principle of induced latent polarityof atoms, but even so the gap in reactivity existing between thefirst and second bromine atoms certainly requires explanation.Ingold (see below) has pointed out that the gem-dialkyl group hasa remarkable effect in promoting the formation of cyclic structures,and it is found on calculation that the PP-dialkylglutaric acidsoccupy intermediate positions between glutaric and adipic acidsin respect of tjhe stability of cyclic ketones into which the% ANNUAL REPORTS O N THE PROGRESS O F CHEMISTRYmight' be converted by distillation of their calcium salts.Actuallyit was found that the cyczobutanones were formed, but a t the hightemperature of the reaction underwent isomerisation. Thus pp-dimethylglutaric acid yielded mesityl oxide.Other gem-dialkylglutaric acids behaved similarly, but no traceof unsaturated ketone could be obtained from the calcium salts ofglutaric acid and of p-rnethylglutaric acid.70C. K.Ingold has published a series of important researches onthe subject of the conditions underlying the formation of unsaturatedand cyclic compounds, which he prefaces in the first paper 71 by anaccount of a new and very interesting hypothesis relating to t'hecalculation of the angles between carbon-to-carbon valencies. Hesuggests that the atoms joined to a carbon atom may be consideredto occupy spherical domains, the cubic contents of which are pro-portional to the atomic volume of the element. These spheres arepresumed to be in rnut'ual contact and also with an internal sphere,and if now the centres of two of the external spheres are joined, theangle between the valencies is that subterided by this line a t thecentre of the internal sphere.These angles are readily calculated,and in a polymethylene chain the angle between carbon-to-carbonvalencies is nearly 6" greater than has hitherto been supposed.A very interesting result which follows is that the ease of formationof polymethylenes should be in the order cycZohexane>cyclopentane>cycZopropane>cycZobutane>cycZoheptane. This is in excellentagreement with thermochemical data and general chemical ex-perience, especially the difficulty of producing cyclobutane deriv-atives. The powerful ring-promoting properties of the gem-dialkylgrouping is easily accounted for on these lines, although it stillremains a mystery why the cyclobutanedicarboxylic acid (XXXI)should be so easily obtained, and many attempts to synthesisenorpinic acid (XXXII) have always failed.(XXXI.) (XXXII. )Some striking instances of the effect are recalled ; the fact that allknown p-lactones contain the gem-dimethyl grouping, the stabilityof pp-dimethylglutaric anhydride, and the observation of Perkinand Thorpe that aPP-trimethylglutaric anhydride crystallises fromwater with solvent of crystallisation.In adopting a plan of campaign with the object of testing this7O G. A. R. Kon, T., 1921, 119, 810. 71 Ibid., 305ORGANIC CHEMISTRY. 97theory of the effect of atomic volumes on valency-to-valency angles,it was thought desirable to study a reaction which proceeds partlyto a cyclic substance and partly in other directions, and the actionof alkali hydroxides on a-bromo-dibasic acids was chosen.Thenormal products are a cyclic compound, an unsaturated substance,and a hydroxy-derivative. A detailed study of the action of con-centrated sodium hydroxide on a- bromoglutaric acid and aa'-dibromoglutaric acid, diethyl a-bromo-glutaconate, 72 a-bromoadipicacid, and am'-dibromoadipic acid 73 has been carried out and con-siderable experimental difficulties overcome in the isolation of a largeproportion of the total product. The results are in general agree-ment with the theory, but do not lend themselves to summarisa-Lion in view of the large number of side reactions encountered.Some compounds of novel type were prepared in the course ofthe work.Among these may be mentioned cyclopropanoldicarb-oxylic acid (XXXIII), obtained by the action of aqueous sodiumcarbonate on dimethyl ad-dibromoglutarate. The first productis the corresponding bromo-acid.XXXIII yielded cyclopropanone (XXXIV) by the action ofconcentrated sulphuric acid. The ketone was characterised byits semicarbazone.(XXXIII. ) (XXXIV.)Ethyl bromoglutaconate was prepared by the action of diethyl-aniline on glutaconic ester dibromide, and this substance or ccp-dibromoglutaric acid, on treatment with alkali, gave rise amongother substances to cyclopropenedicarboxylic acid (XXXV) andpyromellitic acid (XXXVI) .yH-CO,H C*CO,H CO,H/ CO HCH'%C02H OT CH,<~.CO,H C02H( >,OiH(XXXV.) (XXXVI.)The stereoisomeric dibromo- and di-iodo-adipic esters, on boilingwith 2N-sodium carbonate, gave good yields of muconic acid(XXXVII), which is thus for the first time an available substance,whilst a small yield of cyclobutene- 1 : 2-dicarboxylic acid (XXXVIII)resulted under the same conditions from the so-called racemicesters only.CO,H*CH:CH*CH:CH*CO,H vH,-#*CO,H(XXXVII.) CH,-C*CO,H72 E. H. Farmer and C. K. Ingold, T., 1921,119, 2001.73 C. K. Ingold, ibid., 951.REP.----VOL. XVm. E(XXXVIII.98 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The configurations employed by Ingold for the dibromoadipicacids are different from those arrived a t by the method alreadydescribed (see above), but as they are deduced from the relatedtetrahydrofurandicarboxylic acids, the possibility of the occurrenceof a Walden inversion must be taken into account.In order toharmonise the results, the Walden inversion would be required tooccur in the case of the replacement of one bromine atom only,or, of course, there could be a double inversion in the one seriesand inversion a t only one of the asymmetric carbon atoms in theother. In any case, the further investigation of the problem wouldbe of much interest.Pinene Derivatives.-Very considerable progress towards thegoal of the complete synthesis of pinene has been recorded 74 andthis most important of all terpenes can now be produced frompinonic acid (XXXIX).Ethyl r-pinonate condenses with ethyl chloroacetate in presenceof sodium ethoxide to a glycidic ester, from which the acid XL isobtained on hydrolysis.The latter substance is converted on heat-ing at 230" in a vacuum to the semi-aldehyde of homopinocamphoricacid (XLI), readily oxidised to homopinocamphoric acid (XLII).Thence r-pinocamphone (XLIII) is obtainable by applying the Dieck-mann reaction. a-Pinene (XLIV) has been already obtained byTschugaeff 75 from the corresponding alcohol, pinocampheol, by thexanthogenate reaction and now from a pinocamphylamine by themethod of exhaustive rnethylati~n.~~ The base employed in thelatter process is a stereoisomeride of the known pinocamphylamineof Wallach and of Tilden, and is obtained by the hydrogenationof pinylamine, which latter is proved 77 to be a [3-pinene derivative(XLV).It does not appear to have been actually prepared frompinocamphone.C02H*C&*CH<cMe~CH*CHMe*CH0 CHZ(=I. 174 L. Ruzicka and H. Trebler, Helv. Chim. Acta, 1921, 4, 666; A., i, 796.7 5 A., 1908, i, 93.76 L. Ruzicka and H. Trebler, Hdu. Chirn. A&, 1920, 3, 756; A., i, 36.77 Ibid., 1921, 4, 566; A., i, 573ORGANIC CHEMISTRY. 99coCO,H*CH,*CH <CMeDCH*CHMe*CO,HC*,(XLII.)CH/\I PYI CH,X CH,CH 1 YYl CH p Y I H CH CH CH/\MeC CH,/\MeCH CH,\/CMe,\/CMe,\/CMe,(XLIII. ) (XLIV. ) (XLV.)It has been demonstrated78 that the action of dry hydrogenchloride on pinene a t low temperatures does not yield bornylchloride, but a true pinene hydrochloride, which is a liquid. Thistert.-pinene hydrochloride is only stable below -lo", and in theabsence of cooling changes spontaneously to solid bornyl chloridewith evolution of heat.Pol ynwlear Types.Hydrindene Group.-Hydrindene itself has not previously beenclosely studied.It can be easily obtained in quantity by thehydrogenation of crude indene, ' 9 and its behaviour resembles thatof tetrahydronaphthalene. A very large number of diketohydrin-denes have been prepared by condensing aromatic hydrocarbonswith dimethyl- and diethyl-malonyl chlorides with the aid of alumin-ium chloride.80 The observation that diethyhalonyl chlorideis far more suitable than the dimethyl compound for the preparationof alkylated diketohydrindene derivatives from phenolic ethersis perhaps an example of the application of Ingold's hypothesiswhich is discussed above.Naphthalene Group.-Hydrogenated naphthalene derivativeshave engrossed much attention recently, partly, no doubt, becausetetrahydronaphthalene is now an article of commerce.The impor-tant discovery made by Rowe and referred to last year, that thereduction of naphthalene by means of sodium and alcohol leadsto A,-dihydronaphthalene, which is only hydrogemted furtherafter isomerisation to the Al-isomeride, has been found to haveits parallel in the cases of the reduction of a-naphthylamine and7a 0. Aschan, 0fvvers. PimEa Vet.-Soc., 1614, 5'7, [A], NG. I, 35 pp.; A.,7s W. Borsehe and M. Pormner, Ber., 1021,64, [B], 102; A., i, 168.so K. FleisoheF, Annalen, 1921, 422, 231; A., i, 251; K. Fleischer and1921, i, 795.F.Seifert, ibid., 272 j A., i, 254.E 100 ANNUAL REPORTS ON THE PEOGRESS OF CHEMISTRY.a-naphthol.81 In each case a 5 : 8-dihydro-derivative is firstformed and subsequently. isomerised by the action of a sodiumalkyloxide solution a t a suitable concentration and temperature.It is not known whether the A1-derivatives produced in this seriesof experiments are 5XLVII),: 6- or 7 : 8-dihydro-compounds (XLVI and(or OH) CH2 NH2 (or OH)/\/\\i\/c"zl I I J(XLVI.) (XLVII.)but apparently only one of these is obtained. Theoretical considera-tions indicate the second alternative as most probably the correctrepresentation of the constitution of these substances.The work of Rowe on the reduction of naphthalene has beenconfirmed by F.Straus and L. Lemmel, who have made a verythorough study of the transformations of Al-dihydronaphthalene 82so as to compare the behaviour of the substance with that of pro-penylbenzene. The dibromide of the hydrocarbon yields 2-bromo-1 -hydroxynaphthalene (XLVIII) by the action of magnesiumcarbonate in aqueous acetone. This substance may be oxidisedto a bromo-ketone yielding 1 -keto-tetrahydronaphthalene (XLIX)on reduction. On the other hand, the bromohydrin (XLVIII) isconverted by alcoholic potassium hydroxide to an ethylene oxide(L), which is transformed into 2-keto-tetrahydronaphthalene (LI) bytreatment with dry hydrogen chloride.CH*OH CO(XLVIII. ) (XLIX.)(L. 1 (LI.)A1-Dihydronaphthalene dibromide may be conveniently obtained8 1 F.M. Rowe and (Miss) E. Levin, T., 1920,117, 1574; 1921, U9,2021.82 F. Straus and L. Lemmel, Ber., 1921, 54, [BJ, 25; A., i, 170; F. Strausand A. Rohrbecker (and, in part, L. Lemmel), ibid., 40; A., i, 171ORGANIC CHEMISTRY. 101.by the bromination of tetrahydronaphthalene,= and the dihydro-naphthalene readily obtained by the action of zinc and alcohol onthe dibromide. If, however, the alcohol is replaced by a non-hydroxylic solvent, an energetic reaction leads to the productionof several compounds ; among them the polymeride, (C10H10)8,a yellow powder. The action of sulphuric acid on a solution ofthe dihydronaphthalene in a hydrocarbon results in dimerisationto a crystalline product, m. p. 93", together with oily isomerides.A very ingenious attempt g4 to provide a synthetic substitutefor the higher fatty acids depends on the catalytic reduction ofa-naphthoyl-o-benzoic acid, CloH,*CO*C6H4*C02H.This compoundis potentially sufficiently cheaply prepared to meet the end in view,since it requires only naphthalene as the organic starting point.The acid is reduced by hydrogen in presence of oxygenated platinumto four stereoisomeric perhydro-a-naphthylmethylbenzoic acids,C,oHl,*CH2*C6Hlo*C02H, a dihydro-acid containing the carbonylgroup representing an isolable intermediate stage. The perhydro -acids have the constitution of stearic acid less six hydrogen atomsfrom positions 1, 6, 8, 12, 17, 17 due to the three rings contained,and their alkali salts are soaps corresponding approximately withthose derived from fatty acids containing ten carbon atoms. Thealkaline earth and heavy metal salts are soluble in hydrocarbons.In this connexion it may be mentioned that in the course of an exten-sive research which may ultimately indicate an entirely new methodof constitutional analysis, W.B. Hardy has shown that no cycliccompound is an efficient lubricant of a bismuth to bismuth surface.85Gattermann's synthesis of hydroxyaldehydes from phenols andhydrogen cyanide in presence of hydrogen chloride and zinc chloride,followed by hydrolysis of the aldimine hydrochloride, has beenapplied to the ten dihydroxynaphthalenes,86 all of which undergothe synthesis, with production of thirteen (possibly more) dihydroxy-naphthaldehydes, only one of which had previously been accuratelydescribed.The introduction of the substituent was found toproceed according to established rules, 2-naphthols being reactivein the l-position and l-naphthols in the 4-position and to a smallerextent in the 2-position. Curiously enough, 1 : 5-dihydroxy-naphthalene gives the p-hydroxyaldehyde only, whilst 1 : 8-dihydr-oxynaphthalene gives rise to both o- and p-derivatives, thelatter in very much greater relative amount. The oxidation of1 : 7-dihydroxynaphthalene by means of lead peroxide in benzeneJ. von Braun and G. Kirschbaum, Ber., 1921, 54, [B], 597; A., i, 407.** R. Willstiitter, D.R.-P. 325714; A., i, 177; R. Willstatter and E.86 Phil. Mag., 1920, [vi], 40, 201; A., 1920, ii, 534.8 6 G.T. Morgan and D. C. Vining, T., 1921,119, 177.Waldschmidt-Leitz, Ber., 1921, 54, [B], 1420; A., i, 667102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.suspension produces mainly a carbonate and a small yield of a&naphtha-1 : 7-1' : 7'-diquinone, probably of the annexed con-stitutionThe diquinone forms a yellow, additive compound with benzene,C20H1004,C6H6, whilst the benzene-free compound crystahesin pale orange tablets which become bright red a t 160", revertingto the original colour on ~00ling.87 No adequate account is possiblehere of Morgan and Smith's researches on the constitution of simpleand complex cobaltic lakes of various naphthaquinoneoximes,88but the subject must not be passed without an appreciative referenceto a very successful application of the co-ordination theory.Thepaper is one which must be consulted in the original by all thosewho are interested in the problems of valency theory.Acemphthene Group.-p-Methoxyacenaphthenequinone (LII) isreadily obtained by the condensation of p-naphthyl methyl etherand phenyloxaliminochloride with the help of aluminium chloride,89but this otherwise useful synthesis is not of general applicability.70-70(LII. )\/(LIII.)CH2Pericyclic derivatives of acenaphthene are not numerous, butmay be obtained by the one-stage indanedione synthesis mentionedabove. The most interesting example is that of the substance(LIII) prepared by the action of aluminium chloride on a mixtureof malonyl bromide and acenaphthene in carbon disulphide solution.g0Anthracene Group.-As usual, there has been much activityevinced in the preparation of substituted anthraquinones, and the87 G.T. MorganandD. C. Vining, T., 1921, 119, 1707.88 Ibid., 704.*$ H. Staudinger, H. Goldstein, and E. Schlenker, Helv. Chim. Acta, 1921,K. Fleischer, H. Hittel: and P. Wolff, Ber., 1920, 53, [B], 1847; A.,4, 342 ; A., i, 433.1920, i, 853ORGANIC CHEMISTRY. 103results are on the whole in accord with previous experience andscarcely call for special attention, The various dibromoanthra-quinones have been carefully oriented 91 and the conclusion hasbeen reached that the dibromoanthraquinone employed by Graebeand Liebermann in the synthesis of alizarin must have been the2 : 3- or 2 : 7-isomeride.The products of the dinitration of anthraquinone are shown tobe 1 : 5- (37 per cent.), 1 : 8- (37 per cent.), 1 : 7- (4.2 per cent.),1 : 6- (3'6 per cent.), 2 : 6- (6 per cent.), 2 : 7- (4 per cent.), leavingonly 8.2 per cent.unaccounted for and certainly due in part tolosses in manipulation. The literature in this field contains therecord of different results and the work under discussion will clearthe air.92Some novel results are recorded in a paper 93 which contains interuliu a description of a convenient process for the preparation ofanthrone. Anthracene dibromide reacts with pyridine to form9 : 10-dihydroanthraquinyldipyridinium dibromide (LIV), whichyields anthrone (LV) in quantitative yield on boiling with water.CH(C6H,NBr)'SH4<CH( C,H,NBr)>C6H4C,H5NBrC 6 H 4 <CH(NRAr)>C CH,- 6 4 HC6H4<)C6H4(LVI.) (r..vII.)The action of sodium hydroxide (or aliphatic amines) and ofaromatic amines leads to the production of the stable anthranyl-pyridinium salt (LVI) and the reduced derivative (LVII) respec-tively.Scholl has proved 94 that the deep violet-blue compoundsexhibiting striking fluorescences which Schaarschmidt 95 ' obtainedby the reduction of l-benzoylanthraquinones with aluminiumor copper powder in concentrated sulphuric acid solution are actuallya new class of compounds containing tervalent carbon. The productfrom 1-p-chlorobenzoylanthraquinone crystallises in violet-blueneedles, m. p. 253", and is represented as shown below. It isunimolecular in boiling nitrobenzene and has unsaturated pro-perties, combining, for example, with p-benzoquinone just as tri-phenylmethyl does.M.Battegay and J. Claudin, Bull. SOC. I n d . Mulhouse, 1920, 86, 632;@e M. Battegay and J. Claudin, Bull. SOC. Ind. Mulhouse, 1920, 86, 628;93 E. de Barry Bamett and J. W. Cook, T., 1921, 119, 901.94 Ber., 1921, 54, [B], 2376; A., i, 872.A., i, 349; Grandmougin, Compt. rend., 1921, 173, 717; A., i, 871.A . , i, 350.A., 1915, i, 566A696; 1916, i, 408104 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.0A reference may be made in this section to the surprising pro-duction of dihydrophenanthrene by the action of bromine onphenanthrene in glacial acetic acid solution in presence of sodiuma~etate.9~New Polynucleur Types.-The pyrogenic distillation of 1 -phenyl-indene induces isomerisation to a new hydrocarbon not identicalwith 2-phen~lindene.~' The substance may be a cyclobutanederivative having either of the constitutionsThe main product of the thermal decomposition of acenaphtheneis acenaphthylene (LVIII), but many other substances are formed 98including colourless leucacene, which crystallises from benzeneas the compound 4C54H32,5C6H6, violet rhodacene, bronze-redchalkacene , polyacenaphthylene, C,,,H, , 6, and three chromacenes,one of which is black.To chalkacene the formula (LIX) is assigned, and rhodacene isapparently regarded as a quinonoid form of the same arrangementof nuclei.Rhodacene is obtained by boiling leucacene with nitro-benzene, whereby acenaphthylene (2 mols.) is split off a t the sametime.VHICH/\/\I l l\/\/(LVIII.) (LIX.)The formula of rhodacene contains four tervalent carbon atomsmarked a, b, c, d in the chalkacene formula (LIX) and if this is reallycorrect it is not surprising that isomerisation to chalkacene takesplace under the influence of light or on continued boiling in nitro-benzene.96 F.Mayer and A. Sieglitz (with W. Ludwig), ibid., [B], 1397; A., i, 554.9 7 H. Henstock, T., 1921, 119, 1461.98 K. Dziewonski (with J. Podgdrska, Z. Lemberger, and J. Suszkal, Ber..1920, 53, [B], 2173; A , , i, 105ORGANIC CHEMISTRY. 105Cornpounds containing Xilicon, Arsenic, and Metals.The action of sodium on diphenylsilicon dichloride is complexand results in the production of three crystalline compounds, twoof which have been examined, as well as other substance^.^^ Thecrystalline compounds both give values in molecular-weight deter-minations approximating to those required for the formula Si,Ph,.One of the substances is saturated, but the other readily forms aniodide, Si4Ph812, and an oxide, Si,Ph,O.A second oxide, Si,Ph,O,,is the result of the action of boiling nitrobenzene on the unsaturatedsilicohydrocarbon, whereas the isomeride crystallises unchangedfrom this solvent. No little difficulty is experienced in assigningformuh to these substances, for the composition in each casesuggests the constitution (LX). The iodide and oxide would thenhave the formulae (LXI) and (LXII), whilst the dioxide is con-sidered to be either (LXIII) or (LXIV).The isomerism of the" saturated " and " unsaturated " silicohydrocarbons may, it isthought, be explained on the basis that they are both octaphenyl-silicotetranes having silicon atoms in coplanar and tetrahedralarrangements respectively.$SPh,-SiPh,ISiPh,<EE:>SiPh, SiPh,-SiPh,I>o SiPb-SiPh,&Ph,-SiPh,TPh, -0-SiPh,SiPh,-O-&iPh,(LXII.) (LXIII.)SiPh <SfPh2-o>SiPh, SiPh,-0(LXIV. )Much attention has been devoted to organic compounds ofphosphorus, arsenic, antimony, and bismuth, but on account oflimitations of space even some outstanding results cannot bediscussed.H. King 1 has tracked down the sulphur-containing constituentof salvarsan prepared by the hyposulphite reduction method andfinds it to be 3 : 3'-diamino-4 : 4'-dihydroxy-5-sulphoarsenobenzenemonohydrochloride,NH3C1 NH2HO/-\As,/-\OHS03H\-/ \-/F.S. Kipping and J. E. Sands, T., 1921, 119, 835.Ibid., 1107, 1415.E106 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The new o-aminophenolsulphonic acid which can be obtainedby hydrolysis of this arsenobenzene derivative has been synthesised,and the mechanism of the introduction of the sulphonic group isan interesting problem.The application of the diazo-synthesis to the production of aryl-arsinic2 and aryl-stibinic acids has been studied with valuableresults, including the determination of the optimal conditions forthe reaction; thus, for example, in the case of the arsinic acids thealkalinity of the solution should be regulated so that the processcan occur in accordance with the equation :-In the case of the stibinic acids, the solution may be alkaline, anda really convenient process for the production of aryl antimonyderivatives is available.The aryl-stibinic acids are apparentlyderived from a polymerised antimonic acid, and are pronouncedlycolloidal in their properties. Phenylstibine tetrachloride, PhSbC14,is obtained from phenylstibinic acid by the action of concentratedhydrochloric acid; on heating, it dissociates into chlorine andphenyldichlorostibine, PhSbCl,, and the latter undergoes furtherdecomposition with the production of diphenylchlorostibine,Ph,SbCl, and antimony chloride. The action of sulphurous acidon phenylstibinic acid leads to phenylstibinic oxide, PhSbO, andmore energetic reduction produces .stibiobenzene, PhSbZSbPh,which is a brown, amorphous powder very susceptible to atmosphericoxidation.A large number of arylbismuthine derivatives have been preparedby applications of the Grignard reaction and from bismuth haloidsand mercury diaryls. Thus bismuth bromide and mercury diphenylinteract with production of triphenylbismuthine in quantitativeyield.Triarylbismuthines react as a rule with bismuth haloids to pra-duce diarylbismuthine haloids, but tri-a-naphthylbismuthine andbismuth bromide yield a-naphthylbismuthine dibromide in whateverproportion they are mixed.The preparation of lead tricyclohexyl as a crystalline substanceof molecular weight corresponding in dilute solution with the formulaPb(C,H1,), places beyond doubt the existence of tervalent lead inorganic compounds.5 The substance is obtained by the additionof lead chloride to a solution of magnesium cyclohexyl bromide2 H.Schmidt, Annalen, 1920, 421, 159; A., 1920, i, 897.4 F. Challenger and C. F. Allpress, T., 1921, 119, 913.5 R. Krause, Ber., 1921, 54, [BJ, 2060; A., i, 825.Idem, ibid., 174; A., 1920, i, 900ORUANIC CHEMISTRY. 107in ether, and is readily converted by iodine into lead tricyclohexyliodide. In view of its unsattwated character the compound iscompared with triphenylmethyl.I desire to thank Miss M. Jobson, M.A., B.Sc., for much assistanceThe period covered includes in drawing up the foregoing report.December 1920 and 1921.R.ROBINSON.PART III.-HETEROCYCLIC DIVISION.ALTHOUGH the general level of interest of the work published thisyear is perhaps somewhat lower than that dealt with last year, avery small proportion is such that it can reasonably be passedunnoticed in an Annual Report. This fact, with a decided in-crease in the volume of work published, and the Reporter’s desireto supply suflficient detail for a reasonable grasp of the topicsreviewed in the limited space at his disposal, must explain anyterseness of expression.Ring B’ormatioib.The synthetical operations recorded during the period underreview afford SL number of illustrations of the various influenceswhich affect the process of ring formation ; these it seems preferableto consider collectively rather than under the separate classes ofcompounds from which they are drawn.The syntheses of the seven-membered rings contained in homo-morpholine (I) and its benzo-derivative (11) are of the usual type,but require careful adherence to special conditions and furnishvery moderate yields : 1(11.)The products, however, which are strongly basic,J.von Braun and 0. Braunsdorf, Ber., 1921, 64, [B], 685;obtained do not exhibit any particular instability.when onceA., i, 435.E 2108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It would appear that the Uuences, familiarly grouped underthe term " steric," have much less influence on intramolecularthan on intermolecular reactions.2 Thus, by the action of aluminiumchloride on the requisite oxalyl chlorides, of the type (111), thecoumarandiones (IV-VIII) are readily ~btained.~ The formationof 5-methylcoumarandione (IV) rather than its 3-methyl isomerideis not necessarily due to steric causes, since the alkyl group insuch reactions is known to exert a para-directive influence.Thepresence of the methyl group in the meta-position to the oxygenatom has an important influence on the result, comparable withMeArO*CO*COCl Me1 /)--YO / ) - Y O\ / \ P O 0 Me!/\/co 0(111.) (IV. 1 (V.)(VI.) (VII. ) (VIII.)its favourable influence on the stability of co~maranones.~ Thus,from phenyloxalyl or p-tolyloxalyl chloride, in place of coumaran-diones, o-hydroxybenzoyl chlorides and carbon monoxide areproduced :Me/\COCl +()OHIn coniiexioii with this interesting reaction, it is worth noting thatoxalyl chloride itself is decomposed by aluminium chloride intocarbonyl chloride and carbon monoxide,b and that no signs ofpara-compounds could be detected among the products fromphenyloxalyl chloride.These facts, together with the well-knowntendency of aluminium chloride to effect hydrolysis, suggest thatthe products in brackets may represent intermediate stages in theCompare J. Kenner and E. Witham, T., 1921, 119, 1452.R. Stoll6 and E. Knebel, Ber., 1921, 54, [ B ] , 1213; A., i, 578; H.Staudinger, E. Schlenker, and H. Goldstein, HeZv. Chim. Acta, 1921, 4,A34 ; A., i, 432.K. von Auwers, Annalen, 1920, 421, 1 ; A . , 1920, i, 866.H.Staudinger, E. Schlenker, and H. Goldstein, Zoc. citORGANIC CHEMISTRY. 109reaction. Again, tetrahydrocarbazole is best prepared by anapplication of the well-known indole synthesis, consisting in boilingcyclohexanonephenylhydrazone with glacial acetic acid, and thisreaction has been successfully extended to the 2-chloro-&nitro-phenylhydrazone (IX) : 6Another factor which appears to affect the formation of rings ontwo sides of a central benzene nucleus is some disinclination totheir production in straight alignment, as typified by anthracene.The illustration, supplied in last year's Report,' of the formationof an acrylic acid rather than a coumarin, from 5-hydroxycou-marone-4-aldehyde by condensation with acetic anhydride andsodium acetate, has been confirmed.8 Further, whereas ethyl2 : 4-dinitro-5-hydrazinophenylacetate (X) is easily converted byalkali into an azimino-compound, according to the reaction usuallyexhibited by o-nitrophenylhydrazines,N*OH(XI.)4 : 6-&nitro-1 : 3-dihydrazinobenzene (XI) is decomposed by alkaliwith evolution of gas.g That the resistance to the formation of aring system of the anthracene type is not, however, always invincible,is shown by an investigation,1° which has also cleared up the dis-puted question as to the mode of coupling of m-phenylenediamines.Thus, from benzeneazo-m-phenylenediamine (XII), a triazolederivative (XIII) is obtained by oxidation with ammoniacal copper6 W.H. Perkin, jun., and S. G. P. Plant, T., 1921, 119, 1825; compareDrechsel, J .pr. Chern., 1888, [ii], 38, 65; Baeyer, Ber., 1889, 22, 2185;Annalen, 1894,278, 105; A,, 1888, 1276; 1889, 1162; 1894, 174.7 P. 102.8 P. Karrer, A. Rudlinger, A. Glattfelder, and L. Waitz, Hdv. Chim. Acta,1921, 4, 718; A., i, 800.W. Borsche, Ber., 1921, 54, [B], 669; A., i, 461.Co., Patentanrneldung, K 60493, iv, 12 pp.10 M. P. Schmidt and A. HagenbGoker, ibid., 2191; A., i, 897; Kalle an110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sulphate solution. Since only those substitution derivatives ofthis compound, as of p-naphthylamine, will couple further whichhave a free 4-position, benzeneazo-5-amino-2-phenyl-2 : 1 : 3-benz-triazole has the formula (XIV), and so furnishes a bistriaaole of theconstitution (XV). This product is also obtainable from the com-pound contained in the filtrate from the dye prepared by couplingm-phenylenediamine with two molecules of diazotised aniline.The dye itself may be converted into an isomeric compound, towhich the formula (XVI) must be assigned :(XIII.) (XIV.) 1'(XII.)(XVI.)It therefore follows that coupling with m-phenylenediamine occursin both the possible ways, a point in noteworthy contrast with thebehaviour of the triazole derivative.Further work has emphasised the intricacy of the conditionsgoverning the formation of cyclic compounds from derivativesof o-hydroxyphenyl vinyl ketone.ll Thus, it has long beenknown that the bromides of o-acetoxyphenyl styryl ketones (XVII)are converted by treatment with alkali in some cases into cou-maranones (XVIII), in others into flavones (XIX), according tothe nature and position of the substituents in the two nuclei :coX C H / \CHBr ' 3\0Ac bHBr*C,H4*Y(XVIII.) (XIX.)l1 Compare Ann.Reprte, 1920D19,101ORGANIC CHEMISTRY. 111In explanation, it has been supposed that the former change occurswhen the difficulty of hydrolysis permits the prior formation ofthe bromostyryl ketone, whilst the latter occurs when the acetylgroup is easily hydrolysed.12 This is, however, not the case, sincethe dibromides of o-hydroxyphenyl styryl ketones may be con-verted into coumaranones by the addition of hot aqueous sodiumhydroxide to their hot alcoholic solution, whilst a t the ordinarytemperature they yield flavones. The result appears to be due tothe simultaneous operation of two parallel reactions, the relativevelocities of which are determined partly by external conditions,partly by the nature of the/\/\CHBr co /substituents in the benzene nuclei :co \)OH dHBrPh()/\CHBr/\/6HPh0co0coThe especial instability of the five-membered ring in the l-alkyl-coumaranones is apparently even more pronounced in the l-phenylderi~atives.1~ Thus, the action of sodium hydroxide on a-bromo-2-hydroxy-5-methyldeoxybenzoin (XX) should, according to theprecedent of compounds containing an alkyl in place of a phenylgroup in the side chain, give rise to 1 -phenyl-4-methylcoumaranone(XXI).COcoMe/\/\\/\/(xx.) \ [ 1 CHPh --30( X X N .)Me/)CO,H(,O*COPhThe product, however, after prolonged exposure to the ‘atmosphereconsists chiefly of 2-hydroxy-5-methylbemil (XXIV), with a small1s Kostanecki and Tambor, Ber., 1899, 32,2268; A,, 1899, i, 891.18 K.von Auwers and L. Anschutz, ibid., 1921, 54, [B], 1543; 4., i, 682;compare Ann. Rep*, 1920,17, 100112 ANNUAL REPORT8 ON THE PROGRESS OF CHEMISTRY.amount of 4-benzoyloxy-m-toluic acid (XXIII), which result fromoxidation of the intermediate deoxybenzoin (XXII) and coumar-anone respectively.l* It may be noted, however, that the methylgroup probably contributes to the results, since the stability ofcoumaranones is diminished by the presence of such groups in theortho- or para-position to the oxygen atom.The results of the action of phenylhydrazine on the phenyl vinylketones are also interesting.15 It is quite in accordance withanticipation that the formation of pyrazolines should become pro-gressively more difficult as the ketone (XXV) is modified by theintroduction of methyl groups in place of the hydrogen atoms ofits methylene group :PhCO*CH:CH, + Phfi*CH,*$!H,(XXV. ) K-NPhIt may also be argued that the formation of a hydrazino-hydrazone(XXVI), with an azo-compound derived from i t by oxidation,from 4-hydroxy-m-tolyl isobutenyl ketone l6 is due to the effectof the ortho-hydroxyl group in so diminishing the rate of hydrazoneformation that addition occurs at the double bond with a relativelymuch greater velocity.Indeed, if p-nitrophenylhydrazine beemployed, the hydrazino-compound (XXVII) represents the finalproduct, since a hydrazone cannot be prepared from it.Further,it is not surprising that the normal hydrazone (XXVIII) can beobtained by the use of the hydrazine hydrochloride, since thiswould obviously have little tendency to react additively at theethylene linking. But it is remarkable that the hydrazone (XXVIII)is converted into a pyrazoline (XXIX) by means of sodium hydr-oxide (or hydrochloric acid), since alkali causes the rearrangementof the original ketone into a chromanone.Again, the p-nitrophenylhydrazone (XXX) of this chromanoneis obtained by the use of hot glacial acetic acid-a reagent which,in the case of the compound (XXV), facilitates pyrazoline formation.The fineness of the balance between the tendencies to chromanoneand pyrazoline formation will be apparent from the fact that fromfive experiments carried out with glacial acetic acid the chromanonewas obtained in three, the pyrazoline in two, cases.The easyformation of a hydrazone from the azo-compound correspondingwith the non-reactive hydrazino-compound (XXVII) is alsonoteworthy.14 K. von Auwers, Ber., 1920, 53, [ B ] , 2271; A., i, 118.15 K. von Auwers and H. Voss, ibid., 1909, 42, 4411; A., 1910, i, 70;16 K. von Auwers and E. Liimmerhirt, Ber., 1921, 54, [B], 1000; A . , i,E. P. Kohler, Amer. Chem. J . , 1909, 42, 775; A., 1909, i, 938.464ORQANTC! CHEMISTRY, 113Me/'\CO*CH:CMe,!,)OH -+W*NHPhMe/\C *CH,*CMe,-NH*NHPh!,)OH(XXVI.)fl*NH*C,H4*N0,CMe/\CO*CH,*CMe2*NH*NH*C6H4*N02!,)OH(XXVII. )(XXX.) +%v 16(XXIX.) (XXVIII.)The syntheses of azines from picryl chloride by condensationwith o-amino-phenols or -thiophenols, or o-phenylenediamines, andsubsequent treatment with alkali, are well known, and can beapplied to the case of l-chloro-2 : 6-dinitrobenzene.17 But 2 : 4 4 -nitro-2'-hydroxydiphenylamine (XXXI) is converted into an oxazine(XXXII) only with much difficulty,ls(XXXI.) (XXXII.)/NH\/\/ '\/\\/ \/ NOJ INO, Ph,HCI I(XXXIII. )whilst 2 : 4-dinitro-2'-benzhydryldiphenylamine (XXXIII) couldnot be converted into a nitrodiphenyl~arbazine,~~ and a nitrophenyl-dihydrophenazine could not be obtained from 2 : 4-dinitro-2'-anilinodiphenylamine.20 Yet the 2 : 6-, and, of course, the 2 : 4 : 6-trinitro-analogues are in each case amenable to condensation.Hereagain, therefore, the position of a substituent is a considerable factorin determining the result.l7 F. Ullmann and E. Kuhn, Annalen, 1909, 366, 79; A., 1909, i, 473.18 F. Kehrmann and (Miss) M. Ramm, Ber., 1920,53, [B], 2265; A., i, 128.10 F. Kehrmann, (Miss) M. Ramm, and Ch. Schmajewski, HeZv. Chim.2o K. Kehrmann and J. Effront, ibid., 517; A,, i, 601.Acta, 1921, 4, 538; A., i, 600114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The operation of yet another factor on the stability of cycliccompounds seems to be distinguishable in the course of the con-densation of 2-thiolbenzoic acid with compounds containing areactive methylene group in presence of sulphuric acid.Forexample, the usual product from acetylacetone is S-oxy( 1 -)thio-naphthen (XXXV). Its 2-acetyl derivative (XXXIV) is obtainedonly under mild conditions of reaction, whilst the 2 : 2-diacetylderivative (XXXVI), of which the initial formation is to bepresumed, cannot be isolated : 21(XXXIV.) (XXXV.)Since 2-acetyl-3-oxy( l-)thionaphthen is a tautomeric substance,the decomposition of the diacetyl derivative would appear to bedue to its tendency to acquire a tautomeric hydrogen atom.22Further, since the alcoholic solution of the monoacetyl derivativeis coloured green by ferric chloride, the compound evidently existsto some extent in the enolic form, which, in the case of ethyl aceto-acetate itself, is known easily to undergo acid hydrolysis. The3-oxythionaphthens are intermediate in their chemical propertiesbetween the coumaranones and the hydrindones.23Ring Transformations.A number of instances have been recorded ih recent years of thetransformation of the five-membered ring of isatin into a six-membered ring.In addition to those already noticed in theseReports,24 reference may be made to the formation of cinchonicacids by condensation of isatin with compounds, such as phenyl-acetic and malonic acids,% which contain a reactive methylene group.The products (XXXVII) and (XXXVIII) are obtained in the casesmentioned. Since the acid (XXXIX) is obtained from N-methyl-21 S. Smiles and E. W. McClelland, T., 1921, 119, 1810; compare A. M.Hutchison and S. Smiles, T., 1912,101, 570.28 Compare F.B. Thole and J. F. Thorpe, T., 1911,99, 2183.28 K. von Auwers and W. Thies, Be?., 1921, 54, [B], 2285; A., i, 120.24 Ann. Reports, 1919, 16, 112; also G. Heller and P. Jacobsohn, Ber.,1921, 54, [B], 1107; A., i, 440.26 W. Borsche and W. Jacobs, ibid., 1914, 47, 354; W. Borsche and W.Sander, ibid., 2816; W. Borsche and R. Meyer, ibid., 1921, 54, [B], 2841;A., 1914, i, 322; 1915, i, 299; 1922, i, 53ORGANIC CHEMISTRY. 115isatin, the formation of an analogous intermediate product fromisatin is assumed :(XXXVII.) (XXXVIII. )/ ,C(CO,H):CH*CO,H(XXXIX. )The conversion of isatin into its p-oxime and 3-nitroquinoline-carboxylic acid by condensation with methazonic acid in presenceof akali26 also involves a t some stage the opening of the indoleI/NHMe \rring :/)-YO CH,*NO, /)-?:NOH /\/%NO, -+I I ' \/\PH (*po + C~H:NOH -,I \/\/coNH NH NThe reverse process-transformation of a pyridine into apyrrole ring-has now been observed for the first time.Ethyl2 : 6-dimethyl-4-cyanomethyl- 1 : 4-dihydropyridine-3 : 5-dicarboxyl-ate (XL) is converted into ethyl 5-methyl-3-cyanomethylpyrrole-2-carboxylate (XLI) under the influence of boiling alcoholic potass-ium hydroxide :NH/CH=7MeCMe:C( C0,Et) C( CO,Et):C.CH,.CNNH/ >CH*CH,*CN NH' I \CMe:C(CO,Et) + \CMe===CH -+ \CMe:CHThe reaction is dependent on the presence of the cyanogen group,since ethyl 2 : 4 : 6-trimethyl-1 : 4-dihydropyridine-3 : 5-dicarboxyl-ate does not undergo a similar change. The constitution of theproduct (XLI) is established by its eventual conversion into 2 : 4-dimethylpyrrole (XLII),,' but it will be noticed that this is notconclusive in respect of the carbethoxy-group.(XL. 1 (XLI.) (XLII.)Xtructural Isomerism.A polemical discussion28 has arisen in regard to the existence26 B.A.S.F., D.R.-P.335197; A., i, 517.2 7 B. Benctry, Ber., 1920,53, [ B ] , 2218; A., i, 127.26 A. Hmtesch, ibid., 1921, 54, [B], 1221, 1257; G. Heller, ibid., 2214;A., i, 697, 598118 ANNUAL REPORTS ON THE PROGRESS OF CHEMTSTRY.of the various alleged isomerides of isatin.29 As the matter isstill in debate a fuller account is postponed, but an interestingpoint has emerged which bears on Hartley's classical measure-ments of the absorption spectrum of O-methylisatin.It wasoverlooked that this compound rapidly isomerises in solution.This was perhaps fortunate, since the close resemblance of theabsorption of this compound in freshly prepared solutions to thoseof isatin and its N-methyl derivative might have delayed recog-nition of a method which has since proved of such value in con-nesion with the study of tautomeric compounds.A further investigation of the isoisatogens, derived from themore highly coloured isatogens by treatment with alcoholichydrogen chloride, has shown that they have the molecular weightdemanded by the formula (XLIII) originally proposed for them:')lack the oxidising properties of the isatogens, and are not phenolic,but exhibit ketonic properties. Their reconversion into theisatogens (XLIV) by heating them alone or in glacial acetic acidsolution or, most effectively, with phenylcarbimide, also indicatesthe intimate relationship suggested by the formuh : 31(XLIII.) (XLIV.)The formula (XLV) for the furoxans has been defended 32 onthe ground that there is evidence of asymmetry in these compounds.Thus, the amide of f uroxandicarboxylic acid is decomposed,x'E-y*Y H0,C.E -7 HN ~ > 0 HO,C$-fi*OH N N>ONOH NOH f- \/(XLVI.) 0\/0(XLV.) f(XLVII.) 0 02s G. Heller, Ber., 1907, 40, 1291; 1916, 49, 2757; 1917, 50, 1199; 1918,51, 180, 1270; 1919, 52, 437; 1920, 53, [B], 1545; A., 1907, i, 442; 1917,i, 219, 708; 1918, i, 235; 1919, i, 36, 282; 1920, i, 766.30 Compare Ann. Reports, 1919, 15, 109.31 P. Ruggli and A.Bolliger, Helv. Chim. Acta, 1921, 4, 626, 637; A., i, 811,?a H, Wieland, Anden, 1921, 424, 107; A., i, 605.812ORGANIC CHEMISTRY. 117according to the conditions employed, into isonitrosohydroxamicacid (XLVI),S3 or into fulminuric acid (XLVII).3* Although allthe methods of formation of phenylfuroxan, as would be expected,yield the same product (XLVIII) rather than (XLIX), they, andalso the action of nitrogen trioxide on phenylacetylene, first giverise to an unstable isomeride of phenylfuroxan, which passes intothe known derivative, and which may possibly correspond withthe formula (L).35PhE-FH Hs-yPh P h C z - y HN N>O N N>O h/O\N‘4 \/ \/0(XLVIII. ) (XLIX.) (L.10 0An interesting form of desmotropy has been observed with bothdi- and tri-2-quinolylmethanes. These compounds, which areprepared by the interaction of suitable quantities of quinaldineand 2-chloroquinoline, each exist in two interconvertible modifica-tions.Thus, &-2-quinolylmethane, when first prepared, is amixture of the colourless compound (LI) with a small amountof a red isomeride (LII), which is decolorised by bromine and inalcoholic solution is slowly converted into the colourless form,more rapidly in presence of alkali. The same two series of salts-coloured monoacidic and colourless diacidic-are obtainable fromeach. N-Methyl-2-quinolylenequinaldine (LIII) , prepared bymethylation with methyl iodide or sulphate, is also red and stable.36/\/\ /‘\/\1 1 1 I l l \/\/-*:\/\/ N NMe(LIII.)A reference to isomerism among thiophenfound on p.125.(LII.)derivatives will he33 H. Wieland, Annalen, 1909, 367, 56; A., 1909, i, 609.34 C. Ulpiani, Gazzetta, 1905, 35, ii, 7 ; A . , 1905, i, 750.Compare A. G. Green and F. M. Rowe, T., 1912, 101, 2452; 1914, 105,36 G. Scheibe and E. Rossner, B e y . , 1920, 53, [B], 2064; G. Scheibe, ibid.,897, 2023.1921, 54, [B], 786; A., i, 62, 451118 ANNUAL REPORTS ON THE PROGRESS OF CHEMLSTRY.Xtereoisomerisrn .Further attempts have been recorded to prepare tervalentnitrogen compounds, the configuration of which would be likelyto prove sufficiently stable to permit their resolution. One investi-gation:' in which the following series of reactions was attempted,/\- ICOH /\- I 1 fl +CH,Cl*CH,*QH---+I J # -3 \/\PH \/\PH N*CH,*CH,* OH NHN*CH,*CH21 N*CH:CH,(LIV.)was uiisuccessful because, in place of the desired 1-P-iodoethyl-benziminazole (LIV) , a polymeride, resulting from intermolecularquaternary ammonium iodide formation, was obtained.Thestatement that a side-chain could not be introduced into tetra-hydroquinoxaline is at variance with an account 3* of t,hc prepara-tion of 1 : 4-endo-methylene-, -ethylene-, and -trimethylene-6-methyltetrahydroquinoxalines (LV, LVI, and LVII) by treatment(LVI.) (LVII.)of tetrahydroquinoxaline with methylene iodide or formaldehyde,ethylene dibromide, and trimethylene dibromide respectively.Experiments on the synthesis of di-N-methyldi-a-pyrrolidyl-methane (LVIII), obtained as a degradation product of cusk-hygrine,39 have yielded notable results.40 Di-a-pyrryl ketone (LIX)is best prepared by the action of carbonyl chloride on magnesiumFH2-$=2 ( p 2 - $ 3 3 2 EH-EH EH-KH CH, CH-CH,--CH CH, CH C---CO--C CH\/NH\/NH \/NMe\/NMe(LVIII.) (LIX.)37 J.Meisenheimer and B. Wieger, J . pr. Chem., 1921, [ii], 102, 46; A.,38 T. S. Moore and (Miss) I. Doubleday, T., 1921, 119, 1170.3s Compare Ann. Reporta, 1920, 17, 126.40 K. Hess and F. Anselm, Ber., 1921, 54, [B], 2310; A., i, 881.i, 739ORGANIC CHEMISTRY. 119pyrryl bromide or, less satisfactorily, potassium pyrrole,*l andrhasalso been obtained from a-pyrroyl chloride and magnesium p p y lbromide.42 By catalytic reduction, di-a-pyrrolidylmethane isobtained, and this is converted into the desired compound bytreatment with formaldehyde.Both these pyrrolidine derivatives, however, are mixtures ofstereoisomerides. The N-methyl compound furnishes three dis-tinct methiodides, which differ from the two now found to beobtainable from the degradation product of cuskhygrine.It istentatively suggested that the existence of these five isomeridesis another illustration of stereoisomerism connected with the twonitrogen atoms, which, in conjunction with the two asymmetriccarbon atoms, would result in the existence of two meso- and fourracemic compounds. If this be so, it is interesting that theproducts of natural synthesis should differ in configuration fromthose obtained in the laboratory.Asymmetric Rearrangement.An automatic resolution of the quinidine salt of r-hydrocarbo-styril-3-carboxylic acid (LX) occurs when this is prepared in methylalcoholic solution from its components, since the sole product,which is obtained quantitatively, is that derived from the d-acid.The result is due to the enolisation of the acid and the relativelysparing solubility of the salt of the d-acid :CH, C*,/\/\CH*CO$ -+ /\/\U*C02H -+ &-dine solution I I ‘ +- ()\,/C.OH t-NH /i’ Y\ \ / \ P ONH)GCrystalline d-acid salt.f- d-Acid salt solution Z-Acid salt solutionThe result only, differs from an asymmetric synthesis in thatthroughout no change of molecular weight is involved, and istherefore termed an “ asymmetric rearrangement.” Confhma-tion of this explanation is derived from the gradual racemisationof the free active acid, which commences immediately the acidis dissolved.2-o-Carboxybenzylhydrindone (LXI) undergoes asimilar resolution through its brucine salt.44 The formation ofan inactive sulphone from the optically active forms of a-thiodi-propionic acid 45 (LXII) is possibly due to similar causes.41 G. Ciamician and P. Magnaghi, Ber., 1885, 18, 419; A., 1885, 809.49 B. Oddo, Gazzetta, 1920, 50, ii, 258; A., i, 129.43 H. Leuchs, Ber., 1921, 54, [B], 830; A., i, 442.44 H. Leuchs and J. Wutke, ibid., 1913, 46, 2425; A., 1913, i, 974.4 5 J. M. Lov6n and R. Ahlberg, ibid., 1921, 54, [B], 227; A,, i, 223120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.( CHMe*C02H),S -+ ( CHMe*CO,H),SO, CH2 CO,Hf)/\C€€.*CH,/-\ (LXII.)\/\/ '.J co(LXI.)A lkyhtion.Alkylation represents one of the most valued and generalmethods of investigation at the disposal of the organic chemist,and corresponding importance attaches to inquiries as to the varia-tion to be obtained in the results by modification of the experimentalconditions.By the action of methyl iodide on either 2-aminopyridine orits sodium derivative (LXIII), two methyl derivatives are obtained.1 -Methyl-2-pyridoneimide (LXIV) is the chief product in the formercase, whilst 2-methylaminopyridine (LXV) predominates in thelatter :CH CH CH CH\/NMe\/NMe N(LXIII.) (LXIV.) (LXVI.) (LXV.)The structure of the imino-derivative is proved by its hydrolysiswith alkali to ammonia and 1 -methyl-2-pyridone (LXVI) .46 Itsstability towards dilute acids differentiates it from ordinaryketimines, but it may be observed that the same property is exhibitedby the analogously constituted amidine~.~' Interesting as theseresults are, it may be doubted whether they justify the idea thatthey are evidence of " the tautomerism of a-aminopyridine," andthe same applies to other cases of a similar kiqd.48 Thus, theformation of the ketimine is possibly the outcome of reactionsclosely resembling those by which ethyl a-acetylbutyrate isobtained from ethyl P-aminocrotonate : 49F "Ie Et0,C C-NH, -+ Et0,C C:NH,I -+\/CHMe\/CH46 A.E. Tschitschibabin, R. A. Konowalowa, and A. A. Konowalowa, Ber.,4 7 Compare, for example, H. von Pechmann, ibid., 1895, 28, 2368; A.,48 A.E. Tschitschibabin, ibid., 1921, 54, [B], 822; A., i, 451.49 R. Robinson, T., 1916,109, 1039.1921,54, [ B ] , 814; A , , i, 450.1896, i, 31ORGANIC CHEMISTRY. 121y e ?IeCHMeEt0,C C:NH -+ Et0,C CO\/ \/CHMeThe analogy between the behaviour of the two amino-compoundsis not, however, complete, since the crotonate and its sodiumderivative do not furnish a mixture of products on alkylation, andethyl p-amino-a-methylcrotonate, derived from the sodium deriv-ative, does not correspond with the main product from 2-pyridyl-sodamide. But it must also be remembered that the tertiarynitrogen atom of 2-aminopyridine, unlike the methine carbon atomin ethyl p-aminocrotonate, shares with the amino-group thecapacity for combination with the halogen atom of the alkyl iodide.The danger of basing conclusions solely on the results of alkyla-tion is strikingly illustrated by experiments in the indazole series.50The following may serve as illustrations of the variety of resultsobtained. From silver indazole (LXVII) and suitable alkyl iodidesat the ordinary temperature, 2-methyl, l-benzyl, and l-ally1derivatives were obtained, but increasing amounts of the 1 -methylisomeride resulted as the temperature of reaction was raised.Thedirect interaction of indszole with alkyl iodides at 100" gave riseto mixtures, in which the 2-derivatives predominated. By the,use of one sample of benzyl chloride at 140°, l-benzylindazole wasproduced, whilst another sample consistently yielded the 2-deriv-ative.Alkylation in presence of boiling alcoholic sodium hydroxideusually furnished approximately equal amounts of the 1- and2-isomerides.(LXVII.)A detailed study 51 of the methylation of uric acid shows thatthis also is a somewhat complicated process. Conductivitymeasurements of the various methyluric acids show that theacidity of the hydrogen atoms in positions 3, 9, 1, and 7 diminishesin the order given, the last two being so feebly acid that uricacid is dibasic. Alkylation of the dry lead or potassium saltswith alkyl iodides corresponds with that of ethyl acetoacetate,and results in the formation first of 3-, then of 9-methyl derivatives,and the same applies to alkyl derivatives in which these positionsare free :-N:C(OK)- --+ -Nilfe*CO-50 K.von Auwers, Ber., 1919, 52, 1330; K. von Auwers and R. Dereser,ibid., 1340; K. von Auwers and W. Schaich, ibid., 1921, 54, [B], 1738; A.,1919, i, 455,456; 1921, i, 806.b1 H. Biltz and (Miss) L. Herrmann, ibid., 1921, 54. rB1, 1676: A.. i. 691122 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.By the use of methyl sulphate and alkaline solutions, however,the least acidic hydrogen atoms are first replaced. Thus therespective products from 3 : 7-, 7 : 9-, and 3 : 9-dimethyluric acidsare 1 : 3 : 7-, 1 : 7 : 9-, and equal proportions of 1 : 3 : 9- and3 : 7 : 9-trimethyluric a.cids. Probably quaternary methyl metho-sulphates are first produced, and this occurs by preference at themost basic (least acidic) nitrogen atom of the uric acid molecule :Me/\S04MeBut this explanation does not seem to meet all the facts, since,by treatment of uric acid with methyl sulphate, a considerableproportion of 1 : 3-dimethyluric acid is produced.It would there-fore appear that other factors are in operation, as, indeed, isrecognised to be the case when methyl iodide is used in place ofthe sulphate. The mode of action of formaldehyde appears tocorrespond with that of methyl sulphate. The use of diazo-methane s8 yields noteworthy results. Although compounds inwhich the 3- and 9-positions are already alkylated do not react,substitution also occurs in the 1- and 7-positions when either ofthe former positions is free. Further, 8- and 2-alkoxy-derivativesare formed in certain cases, but only one such group is produced.Thus uric acid gives rise to 8-methoxy-2 : 6-dihydroxy-1 : 3 : 7-trimethylpurine, which changes at 200" into 1 : 3 : 7 : 9-tetramethyl-uric acid.-NH*CO- + -NH*CO- --+ -NMe*CO-Heterocyclic Arsenic Cwmpounds.The arsenic analogues of phenyl-piperidine and -pyrrolidinewere the only heterocyclic arsenic compounds known 53 until itwas observed that phenarsazine chloride (LXVIII) is readilyobtained by boiling a mixture of arsenious chloride with diphenyl-amine : 64(LXVIII.(LXIX.) (LXX.)The product resembles diphenylarsenious chloride both in itssternutatory and in its chemical actions.The correspondingoxide (but not the hydroxide), methyl ether, acetate, and sulphide62 H. Biltz and F.Max, BW., 1920, 53, [B], 2327; A., i, 131.63 Compare Ann. Reports, 1916, 13, 131. 54 D.R.-P. 281049 (1915)ORGANIC CHEMISTRY. 123are easily obtained and reconverted into the chloride, whilstphenarsazinio acid (LXIX) is obtained by oxidation. Phenarsazine(LXX), best obtained by heating phenarsazine methyl ether, isan orange-yellow compound, chsracterised by the special avidity,reminiscent of the ketens, with which it is reconverted intophenarsazine derivatives by direct combination with suitablereagents.55 Further, arsanthrcne (LXXI) has. been prepared 56by the reactions indicated in the following scheme :The orange-yellow product, or its chloride (LXXII), is oxidised bynitric aoid to arsanthrenic acid (LXXIII). 55Lhme Heterocyclic Sulphur Compounds.Interesting results have been obtained by the action of variousthio-derivatives on diazo-compounds.Thus, diphenyldiazomethaneand t hio benz ophenone yield t e tr ap hen yle t h ylene sul phide ,57 whichcould not be oxidised t o the corresponding ~ulphone,~~ and isdecomposed by heat into tetraphenylethylene and sulphur :From thiocarbonyl chloride and diphenyldiazomethane, as-dichloro-diphvriylethylene sulphide (LXXIV) is fist obtained, but gradually5 5 H. lll\‘ieland and W. Rheinheimer, Annulen, 1921, 423, 1; A., i, 371.L. Rdb, ibid., 39; A., i, 375.H. Staudinger and J. Siegwart, Helv. Chim. Acta, 1920, 3, 833; A.,6 8 Compare H. Stauclinger and P* Pfenninger, Uw., 1916, 49, 1941 ; A.,i, 43.1916, i, 853124 ANNUAL REPORTS ON THE PROGRESS OF; CHEMISTRY.changes into as- dic hlorodiphenyle t h ylene and sulphur .69 Itschlorine atoms are not reactive, but the product (LXXV) obtainedfrom benzoylphenyldiazomethane and thiocarbonyl chloride is de-composed by the moist,ure of the atmosphere into the compound(LXXVI), from which deoxybenzoin and sulphur are produced bythe action of alkali :( LXXIV.) (LXXV. ) (LXXVI.)Five-membered Heterocyclic Structures.It has long been known that the entrance of substituents intothe carbon system of the pyrrole ring, whether directly or in conse-quence of molecular rearrangement of N-substituted derivatives,normally occurs in the 2-position. Evidence is, however, accumu-lating that 3-derivatives may also be formed if the 2-position isnot free.Thus, by the action of sodium ethoxide on 2 : 3 : 5-tri-methylpyrrole a t 200°, its 4-ethyl derivative (phyllopyrrole)(LXXVII), was synthesised. 6o Again, 1 -formyl-2 : 5-dimethyl-pyrrole suffers rearrangement at 200" in presence of zinc chlorideinto 3-aldehydo-2 : 5-dimethylpyrrole (LXXVIII) :Etfi--sMe HE--E*CHO HE--$*CO*CH,MeC CMe MeC CMe MeC CMe\/NH\/NH\/S(LXXVII. ) (LXXVIII. ) (LXXIX.)Similarly, in the thiophen series, 2-thienyl ketones are formed bythe action of acid anhydrides on thiophen.61 But, from 2 : 5-di-methylthiophen 2 : 5-dimethyl-3-thienyl methyl ketone (LXXIX)is obtained, although the reaction proceeds less easily.B2 Further,it had been hoped that the formation of thienylmercurichloridesfrom thiophens G3 by the action of mercuric chloride woyld afforda means of distinguishing 1- from 2-derivatives.This is: however,not the case, since the additive compound (LXXX) has beenobtained from 2 : 5-dimethylthiophen, corresponding with thatformed by the 2 : 4-isomeride (LXXXI) : 64i, 43.H. Staudinger and J. Siegwart, HeEv. Chim. Acta, 1920, 3, 840; A.,60 H. Fischer and E. Bartholomaus, Ber., 1912, 45, 466; A., 1912, i, 297.Ann. Reports, 1917, 14, 124.62 W. Steinkopf and J. Schubert, Annalen, 1921, 424, 1; A . , i, 579.433 Ann. Reports, 1917, 14, 123.04 W. Steinkopf, AnnaEen, 1921, 424, 2 3 ; A., i, 630ORGANIC CHEMISTRY. 125HE-YMe*OH HgC1, Hs--$2H*HgClMeC CH-HgCl‘ MeC CMe*OH’\/S\/S(LXXX.) (LXXXI.)These compounds also have the interest that\ JS(LXXXII. 1they render probablethe formation of such compounds in general as a preliminaryto the mercurichlorides proper.These, with the mercurithio-cyanates obtained from them by double decomposition with sodiumthiocyanate, can be used to characterise the alkyl and aryl thio-phens. By this method, an interesting case of isomerism has beendiscovered. 2 : 5-Diphenylthiophen, m. p. 152”, from diphenacyland phosphorus pentasulphide,65 gives the same mercury deriv-atives as the isomeric product, m. p. 119”’ obtained from an-hydrotriacetophenone disulphide.66 The result recalls the existenceof two forms of dinitrothiophen, of which one is convertible into theother. G7Thiophen may be mono- or di-halogenated by suitable treatmentwith aceto-chloro- or -bromo-amide.68 Although this reactionindicates a certain degree of ~nsaturation~6~ it is suggested thatthe formula (LXXXII) offers the best expression of the propertiesof thiophen.No experiments are described on the attemptedhalogenation of 2 : 5-substituted thiophens by this method.Recognition of the fact that the therapeutic value of ichthyoloils is due to the presence of alkylthiophens 70 has stimulatedinterest in these compounds. The propyl and isopropyl derivativeshave been prepared by the classical methods,71 but these andmethods depending on the action of sulphur on olefines 72 or ofiron pyrites on butadienes 73 are inferior to that which consists inthe reduction of the corresponding ketones by Clemmensen’smethod.74Hydrazine is not a suitable reagent for the reduction of indigotinto indigo-white, since it has no effect by itself, whilst in presenceof alkali reduction occursy but the solution gradually loses its dyeing6 5 S.Kapf and C. Paal, Ber., 1888, 21, 3058; A . , 1888, 839.6 6 E. Baumann and E. Fromm, ibid., 1897,30, 117; A., 1897, i, 191.6 7 V. Meyer, “ Die Thiophengruppe,” p. 98.6 8 W. Steinkopf and A. Otto, Anrbalem, 1921, 424, 61 ; A., i, 579.69 Compare A. Wohl, Ber., 1921, 54, [B], 476; A . , i, 317.70 H. Scheibler, Arch. Phann., 1920, 258, 84.7 1 H. Scheibler and M. Schmidt, Ber., 1921, 54, [BJ, 139; A., i, 191.72 E. Baumann and E. Fromm, ibid., 1895,28, 891; A . , 1895, i, 337.7 3 W. Steinkopf, Annalen, 1914, 403, 11 ; A., 1914, i, 425.74 W.Steinkopf and J. Schubert, loc. cit126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.properties. If air be then drawn through the solution, a yellowprecipitate will separate, to which the constitution (LXXXIII)is attributed. '' Thioindigo " under similar conditions is convertedinto a leuco-compound, from which it is regenerated by the actionof air.75 The colour of indigotin and its derivatives has been dis-cussed from the points of view both of its origin,76 and of its relationto constitution.77(LXXXIII. ) (LXXXIV.)The formation of N-methylnaphthaphenocarbazole (LXXXIV)by the action of as- phenylmeth ylh ydrazine on 2 - hydroxy- 3-naph-thoic acid in presence of sodium hydrogen sulphite 78 is importantin that it confhns the view that the Bucherer-Lepetit reactionproceeds by formation of a bisulphite additive compound of theketonic form of naphthols rather than of a sodium naphthylsulphiteby condensation of the naphthol with the bisulphite.The oxidation of carbazole with potassium permanganate resultsin the formation of three products, of which two have been identifiedas dicarbazyls, although their precise constitution is a t presentindefinite.79 By the use of silver oxide, two products are obtained, ofwhich one appears to be NN-dicarbazyl (LXXXV), and is interestingbecause, although colourless, it gives rise to reddish-brown solutionswith a blue fluorescence. The freezing points of these in benzeneindicate a dissociation varying from 2 0 4 0 per cent.directlywith the concentration, but the compound does not yield a peroxideor decolorise iodine solution.s03N(LXXXV.)(LXXXVII.)(LXXXVI. )7 5 W.BorsoheandR. Meyer, Ber., 1921, 54, [B], 2854; A., 1922, i, 55.713 R. Robinson, J . SOC. Dyers and Col., 1921, 37, 77; A., i, 452.7 7 J. Martinet, Rev. Bdn. Mat. Col., 1921, 25, 17; A , , i, 273.78 P. Friedlhder, Ber., 1921, 54, [ B ] , 620; A., i, 443.'9 W. H. Perkin, jun., and S . H. Tucker, T., 1921,119,216.80 G. E. K. Branch and J. F. Smith, J. Arner. Chem. SOC., 1920, 42, 2405;A., i, 56ORGANIC CHEMISTRY. 127A study of the relationship between the constitution of benz-oxazoles and their visible fluorescence 81 has shown that this occursonly when the 2-position is occupied by an aromatic group and amethyl or a salt-forming (for example, hydroxyl) group is presentin the 6-position.Substitution in the 4-, 5-, or 7-position, however,may inhibit the fluorescence, as in the case of the compoundThe property of diazotisability has been shown in recent yearsto be shared with aromatic amines by a number of heterocycliccompounds, to which 4-amho-3 : 5-dimethylisooxazole (LXXXVII)must now be added.s2Two papers deal with the formation of double compounds ofantipyrine with metallic salts.83(LXXXVI).The Pyrone Group.A straightforward synthesis of 2 : 6-dimethylpyrone consists inthe gradual addition of sulphuric acid to an ice-cold mixture ofacetone and acetic anhydride, although the yield amounts to only4 per cent. : 84O<CO*CH3 CH3>co + O<CMe:CH>CO CO*CH, CH3 CMe:CHSimilarly, by the use of methyl ethyl ketone, 2 : 3 : 6-trimethyl-pyrone is obtained.A synthesis of meconic acid has been achieved 85 by the bromin-ation of ethyl acetonyldioxalate, followed by spontaneous dehydr-ation of the primary product (LXXXVIII) into ethyl S-bromo-chelidonate, from which potassium meconate was obtained bycareful treatment with dilute potassium hydroxide solution.CH,*CO*CO,R CHBrGO*CO,R 1- co/ -+ jco/\CH,-COCO,R \CH,~CO~CO,R>o -+- C d >o(LXXXVIII.)Co/CBr:C*CO,R C( OH):C-CO&\CH:C*CO,R \CH==C*COkf(81 F. Henrich, Ber., 1921, 54, [ B ] , 2492; A., i, 886.83 G. T. Morgan and H. Burgess, T., 1921,119, 697.83 R. G. Fargher and H. King, ibid., 292; E. Oliveri-Mandala, Gazzetta,a4 E.Philippi and R. Seka, Ber., 1921, 54, [B], 1089; A., i, 429; compare86 H. Thoma and R. Pietrulla., BeP. dezct. Pham. Gm., 1921, 31, 4; A.,1921, 51, i, 125; A., i, 378.S. Skra,up and J. Priglinger, Monatah., 1910, 31, 250; A., 1910, i, 678.i, 264128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The result is in itself perhaps not decisive in favour of the 7-pyronerather than of the open-chain formula for meconic acid, since itis well known that the y-pyrone ring is easily opened.*' In illus-tration of this, it has been observed that y-pyrone reacts withaniline acetate at the ordinary temperature, yielding bishydroxy-methyleneacetonedianilide (LXXXIX), from which N-phenyl-y-pyridone (XC) is easily obtained by distillation or by treatmentwith acid or with sodium ethoxide.CH:CH>o CH:CH=NHPh + "O<CHiCH>~~h CII'CHco<CH:CH co<CH:CH*NHPh(LXXXIX.) (XC. )Reference may also be made to an interesting compound in-directly derived from dimethylpyrone by its hydrolysis with bariumhydroxide to the barium salt of diacetylacetone.By the action ofiodine on an alcoholic suspension of this salt, a compound is obtainedto which the formula (XCI) is assigned, and of which the acidicproperties are attributed to its existence in aqueous solution in theform (XCII) : **IH OH\-Lc co\\ /\/ CH \/CH(XCI.) (XCII. )The method for the synthesis of chromones and flavones, whichconsists in the condensation of fLphenoxyfumaric acids by sulphuricacid and of p-phenoxycinnamo yl chlorides by aluminium chloride, 89has been applied to the preparation of derivatives containingchlorinated benzene nuclei, and also to the preparation of 6-benzene-azoflavone :8 6 W.Borsche, Ber., 1916, 49, 2538; A., 1916, i, 117; Ann. Reportcr, 1917,8 7 Compare, for example, R. Willstiitter and R. Pummerer, Ber., 1905, 38,88 J. N. Collie and (Miss) A. A. 3. Reilly, T., 1921, 119, 1550; compare8s S. Ruhemann, Ber., 1913, 46, 2188; A , , 1913, i, 891.13, 131.1461 ; A., 1905, i, 457.J. N. Collie and B. D. Steele, T., 1900, 77, 1116ORGANIC CHEMISTRY. 129coCOCl coThe yields of flavone derivatives are very satisfactory, but thechromones are less readily obtainable.90 Other references to thesynthesis of these compounds will be found in the section on ringformation.2 : 2’-Dimethylchroman is formed by the direct combination ofphenol with isoprene under conditions not definitely specified : 91The identity of the methylated reduction product of catechintetramethyl ether 92 is still under discussion.On the one hand,93it is claimed that no crystallographic difference exists between theproduct in question and synthetic 2 : 4 : 6 : 3‘ : 4’-pentamethoxy-ay-diphenylpropane, that ordinary Gambir catechin is dextro-rotatory, acacatechin being a mixture of the lzvo- with the racemiccompound,Q4 and hence that the reduction product about whichdiscussion centres is also obtained from acacatechin tetramethylether. On the other hand,95 the identity is claimed of acacatechinwith a synthetic, and therefore inactive, 2 : 4 : 6 : 3’ : 4’-penta-h y drox y - 3 - p henylc hroman ( XCIII ) , the t e tr ame t h yl ether of whichwould furnish 2 : 4 : 6 : 3’ : 4’-pentamethoxy-aa-diphenylpropane onreduction.The various stages in the synthesis of the chroman areas shown :90 S. Ruhemann, Ber., 1921, 54, [B], 912; A., i, 430.9 1 L. Claisen, ibid., 200; A., i, 263.g2 Compare Ann. Reports, 1920, 17, 110.93 K. Freudenberg, 0. Bohme, and A. Beckendorf, Ber., 1921, 54, [B],1204; A., i, 576; K. Freudenberg, 2. angew. Chem., 1921, 34, 247; A.,i, 577.g4 Compare also K. Feist and R. Schon, Arch. Pharm., 1920, 258, 317;A., i, 47.95 M. Nierenstein, T., 1921, 119, 164.REP.-VOL. XVIII. 130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.MeOOOMe\/'$?H*CO*CH,CIMeo /\!,)OM8OMe/\!,)OMeOMe0!,,!OMeOMe/'\()OHOH(XCIII.)A chromone has also been identified among the products of theaction of sodium on phenyl acetate.96 The mode of formation of2-methylbenzo-y-pyrone (XCIV), the compound in question, isrepresented by the following equations :CH,*CO*O*C,H, + NaOEt + CH,-C0,Et + NaO*C,H,/\/O*CO*CHNa*COMe2CH,*CO*O*C,H, -+ H, + NnO*c,H,+ I Ico \/I(/\CO*CH2*COMe +j!ONaXCIV. ) 0It may be noted that the production of ethyl acetate, dehydraceticacid, and salicylic acid in the course of the reaction has actuallybeen demonstrated. 1-Hydroxy-3-methylxanthone (XCV) has alsobeen isolated, its formation being due, it is supposed, to reactionsrepresented as follows :CO OH/\,CO*CH,*COMe --+ /\/CO*C'H,*COMe + /\/\/\( , h a \/\O*CO*CH,*COMe \/\/\/ I I i I I I&0(XCV.)96 W.H. Perkin, jun., T., 1921, 119, 1284ORGANIC CHEMISTRY. 131Thiofluorescein, formed by fhe action of sodium sulphide onfluorescein a t 110-150", especially in presence of sodium hydroxide,has been shown to have been incorrectly designatedjg7 and to havethe formula (XCVI) : 98c,H,<)oCO(XCVI.)Condensation products of phenol and resorcinol with coumarinhave been described, which give coloured salts and are probablyanalogues of phenolphthalein and fluorescein respectively.99Galloflavin, one of the products of oxidation of gallic acid inalkaline solution,l is considered to be derived from benzo-cx-pyrone.2It is a non-acid substance, which suffers transformation by coldpotassium hydroxide solution into is~galloflavin.~ Similarly, gallo-flavin tetramethyl ether, obtained by the aid of diazomethane,4is converted into isogalloflavin trimethyl ether.This compound,from which the tetramethyl ether may be obtained, is a lactoneand also contains a carboxyl group, which is destroyed by heatingthe substance a t its melting point, with evolution of carbon dioxideand formation of the compound (XCVII) :C12H,04(0H)4 C12H204(0Me)4 --7,Gallo flavin.C12H204( 0Me)3( OH) -> C1,H,03( OMe),.isoBalloflavin trimethyl ether. (XCVII. )The compound (XCVII), when treated with warm potassiumhydroxide with the object of opening its lactone ring, furnishespotassium formate and a salt (XCVIII), which, on acidificationwith hot acid, yields a new lactone (XCIX) from which potassium07 R.E. Meyer and J. Szanecki, Ber., 1900,33,2577; A., 1900, i, 660.98 T. Maki, J . Coll. Eng. Tokyo Imp. Univ., 1020, 11, 1; A., i, 183.99 S. Krishna, T., 1921, 119, 1420.1 R. Bohn and C. Graebe, Ber., 1887, 20, 2327; A., 1887, 1107.a J. Herzig, Annalen, 1920, 421, 247; A., 1920, i, 863.J. Herzig and R. Wachsler, Monatsh., 1914, 35, 77; A , , 1914, i, 290.* J. Herzig and R. Tscherne, ibid., 1904, 25,-603; A., 1904, i, 814.F 132 ANNUAL REPORTS ON THE PROGRESS OF CEEMISTRY.acetate and 3 : 4 : 5-trimethoxyphthalide are obtained by treat-ment with warm potassium hydroxide solution. From thesevarious relationships, the formulze (I) and (11) are deduced forgalloflavin and isogalloflavin respectively :COcoco CO )CO,K/\CH*OH +-MeO/\/ \ \/\0 1 1 0/\/COGH, CH*CO*CH, Meoo\ /OMe CH,(XCIX.) (XCVIII.)Uric Acid and its Derivatives.Reference has already been made to the formation of 1 : 3-di-methyluric acid, with other products, by direct alkylation of uricacid. This acid is conveniently accessible in the pure conditionby dehydration of 1 : 3-dimethyl-*-uric acid (111), which is pro-duced when +-uric acid (IV) is treated in alkaline solut'ion withmethyl sulphate.5 $-Uric acid itself is easily obtained by chlorin-ation of uric acid in glacial acetic acid suspension at 5-10', andreduction in situ of the resulting 5-chloro-+uric acid (V) by stannouschloride :H.Biltz and others, Annalen, 1921, 423, 119; A., i, 606ORGANIC CHEMISTRY.'OMe(VII.) J.evapora- YH-YOti on SJH-YO rH-yo OH90 VH*NH*CO*NH2 q0 q'NH>Co x gNH-CO(IV. 1NH-C-NH NH-CO'OH(VI.)MeN-YOMeN-COMey-90 70 g-NH, +- $0 YH*NH*CO-NH,MeN--C-NH /co(111.)Lack of space prevents more than reference to other items of a massof experimental material dealing with the reactions (includingalkylation) of the glycols (VI), and their ethers (VII), derivedfrom uric acid and its alkyl derivatives by the reactions indicated.6A series of papers 7 is devoted to the discussion of the productsobtained from uric acid by oxidation in alkaline solution withpotassium permanganate. Potassium uroxanate (VIII) will beproduced if the alkaline solution be concentrated and cooled.If,however, the solution be carefully acidified with acetic acid afterthe addition of alcohol, potassium oxonate (or allantoxanate)(IX) will be precipitated. Allantoin (X) will, however, be obtainedif the acidified solution be left to itself, or concentrated and cooled.It is concluded that the sole intermediate product is hydroxydi-carbainidoethanecarboxylic acid (XI), the formation of which isthe subject of an interesting discussion, which cannot be dea,lt withhere :SJH-70 FO2H 702H@O g-NH NH-C--- NH -+ H,N*CO*NH*C*NHCO*NH,NH-C-NH >CO c O < N ~ + j ~ o H ~ - N H X O bO,H\ J. 'x(VIII.)HO,C*N:C-NH H,N*CO*NH*$?H*NH&O-NH>'' CO-NH>co(IX.) (X. 16 H. Biltz and others, Annalen, 1916, 413, 1; A., 1917, i, 689.7 H.Biltz and R. Robl, Bey., 1920, 53, [B], 1950, 1964, 1967; 1921, 54,[B], 2451; A,, 1920, i, 883,884, 886; 1921, i, 891134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It will be noted that the original Grimeaux formula for allantoin ispreferred to those more recently suggested.*of the variousproducts hitherto erroneously supposed to be 5-hydroxyhydantoin.This compound is the main product of the decomposition ofalloxanic acid in presence of water :Reference may also be made to an investigationThe synthesis of alkylbarbituric acids from malonic acid andthe requisite carbamide may be carried out with the aid of aceticanhydride and phosphoryl chloride, whilst 5-acetyl derivativesmay be obtained by the employment of an excess of aceticanhydride.10The Pyridine Croup.The activity of y-substituents in the pyridine nucleus is illus-trated by a convenient synthesis of y-alkylpyridines. l1 Chelidamicacid (XII) is easily converted by phosphorus pentachloride into4-chloropyridine-2 : 6-dicarboxylic acid (XIII), the chlorine atomof which is more reactive than that of 4-chloropyridine itself, sothat the corresponding ethyl ester reacts with ethyl sodiomalonateand its alkyl derivatives :OH c1(XII.) (XIII.)CR( CO,Et), CH,R/\ /\ ~.Et02d IC0,Et --+ \/N\/NThe tetracarboxylic acids derived from the products by hydrolysislose carbon dioxide on distillation, The chloro-acid has beensimilarly utilised for the preparation of 7-pyridyl mercaptan, l2from which the sulphonic acid is produced by oxidation.The0. Widman, Ber., 1886, 19, 2478; L. B. Mendel and H. D. Dakin, J .Biol. Chem., 1910, 7 , 153; A., 1887, 30; 1910, i, 286; A. W. Titherley, T.,1913,103, 1336.H. Biltz and (Miss) M. Kobel, Ber., 1921, 54, [ B ] , 1802; A., i, 815.lo H. Biltz and H. Wittek, ibid., 1035; A., i, 454.l1 E. Koenigs and W. Jaeschke, ibid., 1351; A., i, 593.l2 E. Koenigs and G. Kinner, ibid., 1357; A,, i, 594ORGANIC CHEMISTRY. 136direct formation of this compound by the use of sodium hydrogensulphite appears not to have been attempted.At a bright red heat, pyridine is decomposed, yielding mainly2 : 2'-, with smaller quantities of 2 : 3'- and 2 : 4'-dipyridyls.13N-Alkylpiperidines and piperidine nitrate will be produced inthe course of a few days by the interaction of piperidine with alkylnitrates a t the ordinary temperature.14The synthesis of ethyl 2 : 6-dimethylcinchomeronate from ethylacetylpyruvate and ethyl p-aminocrotonate 15 has been shown l6to be capable of considerable, although limited, extension by theuse of analogues of each of the reactants.,Several investigations deal with the partial reduction of thepyridine nucleus. Thus, by the reduction of pyridine with zincdust and acetic anhydride,17 diacetotetrahydro-yy-dipyridyl (XIV)is produced, the constitution of which is shown by its synthesisfrom yy-dipyridyl (XV) by reduction with zinc dust and aceticanhydride, and by its conversion into this compound either bythe action of moist air, or by oxidation with lead or manganeseperoxide.This, it may be noted, is the most convenient methodfor preparing yy-dipyridyl. Pyridine is the chief product of theoxidation of diacetotetrahydro-yy-dipyridyl with a solution ofiodine in potassium iodide. These results are explained byassuming the dissociation of the dipyridyl derivative in two ways :/ = \ 3 = \ N . C 0 . C H 3 -+ H'CH,*CO.N(XIV.)\=/ \.J 1 [ CH3*C0*N<l>/b] -+ [ CH3*CO*N/=\/0H] \=/'peroxide I I(XV.)In conformity with this view, the solution of diacetotetrahydro-dipyridyl in glacial acetic acid becomes deep blue on warming,H. Meyer and (Miss) A. Hofmann-Meyer, J . pr. Ghem., 1921, [ii], 102,287 ; A , , i, 739.l4 D. T. Gibson and A.K. Macbeth, T., 1921, 119, 438.l5 Ann. Reports, 1918, 15, 101.0. Mumm and 0. B6hmer, Ber., 1921, 54, [ B ] , 726; A . , i, 439,0. Dimroth and R. Heene, ibid., 2934136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.but is decolorised by air, thus showing a similar behaviour tosolutions of triphenylmethyl. Again, by the action of zinc dustand benzoyl chloride on pyridine, benzoylpyridinium (XVI) isobtained in brown leaflets, which show the corresponding molecularweight in boiling ethylene dibromide or chlorobenzene solution,absorb oxygen from the air with consequent decolorisation, andreact with halogens forming benzoic acid and yy-dipyridyl.1-Benzylpyridinium l9 (XVII) has also been isolated in redcrystals, furnishing deep blue methyl or ethyl alcoholic solutions ;it is converted by halogens into l-benzylpyridinium salts.c>CO*C 6 5 H(XVI.) (XVII.)The partial reduction of certain pyridine derivatives has beenaccomplished by the aid of aluminium arnalgam.,O Thus ethylcollidine- and phenyl-lutidine-dicarboxylates yield the knownsynthetic 1 : 4-dihydro-derivatives,R H R\/Me1’ ‘/Me* EtO,C/\CO,EtEtO,C/\CO,EtMe1 ]Me \/N \/NHbut from ethyl lutidinedicarboxylate itself, a chrome-yellowprimary ” ester (XVIII) is obtained, which is reconverted intothe original compound on exposure to air at the ordinary tem-perature, yields it with its dihydro-derivative in equimolecularproportions when heated to its melting point, and furnishes agreenish-yellow “ secondary ” ester (XIX) on prolonged heatingbelow its melting point in absence of air.The secondary compoundis stable in air, but suffers a similar decomposition when fused :<<Me COzEt C 0 , E t Me H COzEt H COSEtMe I / \I Me --BN/ \------/--\N€I -3 &-\ \ z = / \ H Eff\==/Me COIEt COaEt Me(XVIII. ) H COpEt H COaEt(XIX.)Me COIEt18 E. Weitz, A. Roth, and (Miss) A. Nelken, AnmaZen, 1921, 425, 161;19 E. Weitz, (Miss) A. Nelken (with R. Ludwig), ibid., 187; A., i, 804,20 0. Mumm and W. Beth, Ber., 1921, 54, [B], 1591 ; A., i, 686,A., i, 804.Compare Ann. Reports, 1920,17, 106ORGANIC CHEMISTRY. 137The reader will probably find it difficult to reconcile the formula(XX) suggested for the reduction product of ethyl 2 : 6-dimethyl-cinchomeronate with the statement that it furnishes ammoniawhen treated with cold sodium ethoxide.By absorption of oxygenfrom the air, the compound in question is converted into a product,represented as (XXI), which loses water when heated, reproducingthe original ester.The Quinoline Group.The yield of quinaldine is improved when the Doebner-Millersynthesis is carried out in presence of zinc chloride. At the sametime, the presence of this reagent so enhances the tendency tothe formation of Schiff's bases that the latter are produced inquantity sufficient to absorb the hydrogen which usually causesthe production of tetrahydroquinaldine. Hence, in place of thiscompound, ethyl- and n-butyl-anilines are formed. The reasonfor the simultaneous formation of some 6-ethylquinaldine is forthe time left undecided.21The formation of 3-nitroquinolines by the condensation ofo-aminobenzaldehyde or related compounds with methazonic acid 22seems to be simply a particular case of Friedliinder's well-knownsynthesis :CH/\CHO + ?H2*N0, + I "('?eNo2 +NH2-OH+H20.O N H 2 CH:NOH \/\//cHNA new synthesis of 4-hydroxyquinoline-2-carboxylic (kynurenic)acid consists in the condensation of 4-methoxy-2-methylquinolinewith formaldehyde, followed by oxidation of the 4-methoxy-2-quinolylethyl alcohol thus formed to 4-methoxyquinaldinic acid,and subsequent demethylation of this product : 2321 W.H. Mills, J. E. G. Harris, and H. Lambourne, l'., 1921, 119, 1295.22 W. Meister, Ber., 1907, 40, 3435; B.A.S.F., D.R.-P.335197; A., 1907,23 E. Besthorn ibid., 1921, 54, [ B ] , 1330; A., i, 600.i, 885; 1921, i, 517.F138 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.OMe OMe OMe OH/\/\ +/\/\ -+/\/\ +/\/\I /Me 1 1 JCH2*CH2*OH I 1 bO,H I I hO,H \/\/N\/\/N\/\/ \/\/N NThe reactivity of methyl groups in the methylquinolines isconsiderably greater in the 2- than in the 4-p0sition.~*The conversion of benzeneazo-5-aminoquinoline into the5-hydroxy-derivative by boiling with dilute mineral acid for ashort time25 would seem to indicate that i t easily assumes thequinoneimide form :An examination26 of the cyanines and the isocyanines has sup-ported the conclusions summarised last year,,' and indirect con-firmation of these has been supplied by syntheses of the parentI(/-isocyanine, so called because its mode of formation from quin-aldine corresponds with that of the isocyanines from lepidine.The $-compound results from the action of alcoholic potassiumhydroxide on a mixture of 2-iodoquinolyl methiodide and quin-aldine rnethiodide,,8 and also by the action of methyl iodide onN-methyl-2-quinolylenequinaldine, the synthesis of which hasbeen discussed on p.117. It is hoped that an application of thelatter method will permit a synthesis of isocyanine. The formulafor quinoline-red (XXII) seems an adequate expression of itssynthesis by the action of benzal chloride on di-Z-q~inolylmethane.~~CGH5(XXII. )/--\ /-\(XXIII.)2* 0. Fischer, G. Scheibe, P. Merkel, and R. Miiller, J . pr. Chern., 1919, [ii],25 W.A. Jacobs and M. Heidelberger, J . Anacr. Chettt. Xoc., 1920, 42,26 W. Konig and 0. Treichel, J . p r . ChettL., 1921, [ii], 102, 63; &4., i, 738.27 Ann. Report8, 1920, 17, 121.2 8 0. Fischer and G. Scheibe, J . pr. G'he/tb., 1919, [ii], 100, 86; A., i, 56.29 G. Scheibe, Ber., 1921, 54, [B], 786; A., i, 451.100, 91 ; A . , i, 66.2278; A., i, 44ORGANIC CHEMISTRY. 139(XXIV.)Kryptocyanines are produced by the action of alkali on hotdilute alcoholic solutions of lepidine alkyl iodides in presence offormaldehyde or chloroform .30 Since this reaction correspondsclosely with that by which pinacyano131 is produced from quin-aldine ethiodide, it will probably be found that the new dyes havethe formula (XXIII), rather than (XXIV) tentatively suggestedby their discoverers.Allcaloids.Further progress has been made towards the synthesis of quinineand its derivatives along the lines indicated in last year's Report.32Homonicotinic acid, obtained by the oxidation of lepidine, hasbeen converted into @-collidine by the reactions indicated : 33Me Me MeMe MeHydra~one +at 180 '.'\CO*CH, --+ solid KOH f)Et\/I 1\/N NThe method previously successfully applied to the synthesis ofp-4-piperidylpropionic acid has been extended to the conversionof p-collidine into homocincholeupone,3* and protection has beenobtained for the process whereby the latter compound is utilisedfor the preparation of dihydro-cinchoninone and -quininone.35A general method36 for the reduction of 4-quinolyl ketones byzinc or aluminium powder and sodium ethoxide has the advantagethat it leaves unchanged the unsaturated side-chain in, for example,quininone. Its application to dihydrocinchoniiione results in the30 E.A. Adams and H. L. Haller, J . Amer. Chem. Soc., 1920, 42, 2661 ;A., i, 129.31 Compare Ann. Reports, 1920, 17, 122.33 P. Rabe and E. Jsntzen, Ber., 1921, 54, [ B ] , 925; A., i, 438.34 E. Koenigs and W. Ottmann, ibid., 1343; A . , i, 596.35 Ver. Chinin-Fabr. Zimmer & Co., D.R.-P. 330945; A., i, 380; compareAnn. Reports, 1920, 17, 118.36 Idem, D.R.-P. 330813; A., i, 355.32 P. 117.I!! 2140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.formation of the four possible isomerides, of which the relationshipmay be represented by the following symbols :H-b-N< H-Y--N< )N--$F--H >N- $7-HH-$-OH HO-7-H H-?-OH HO-7-HOf these, two correspond with the minor cinchona alkaloids;the remaining two, which were previously unknown, may bereconverted by known methods through dihydrocinchotoxine intothe original dihydrocinchoninone.Space does not permit of more than passing reference t o theinteresting results of the action of bromine on dihydroquinineand dih ydrocupreine ,37 and of diazo tising 5 - aminocinc hon aalkaloids ?8Previous syntheses of compounds closely related to quininehave been supplemented by those of the compounds (XXV) and(XXVI) .39 Thus, 1 -methyl-2-pyridone was converted by catalyticreduction into the lactam of 6-methylaminovaleric acid (XXVII) .It was not previously known that such lactams are amenable tothe Claisen condensation. I n the present case, the compound(XXVIII) was synthesised by this means, and treated successivelyI 1 Iwith bromine and sodium hydroxide : .__,. CO-$H I, CH2CH2/\NMe N(XXVII.)(XXVIII. )In a similar manner, a homologue of (XXVIII) is obtained fromr-methylaminohexoic lactam,YH2-CH2-CHCH2-CH2 -CO 5 N M e .3 7 R. Weller, Ber., 1921, 54, [B], 230; A., i, 265.38 G. Giernsa and J. Halberkam, ibid., 1167; A., i, 581.39 L. Ruzicka and C. T. Seidel, HeZv. Chim. Acta, 1921, 4, 472; A., i, 685ORGANIC CHEMISTRY. 141The suggestion that harmine is a methylmethoxy-4-carboline 40(XXIX) is now confirmed41 by its degradation to norharman(4-carboline) (XXX) by two separate methods, and the synthesisof the latter compound.1 -Methylindole-2-carboxylic acid (XXXI)is converted through its chloride into l-methylindole-2-carboxy-acetalylamide (XXXII), which, when treated with alcoholichydrochloric acid, furnishes 5- keto -4 : 5-dihy droindolediazine(XXXIII), from which norharman is obtained by distillation withzinc dust :/\- /\-\/\/ \/\/(XXXI.) (XXXII.)I 1 ICO*NH*CH,*CH(OEt), --f I I IC0,H -+NMe NMeCH\/\/\/(XXXIII.)/\-/\CH /\-/\1 I I \1NHNMe CO/\---Me /\-/\I l l\/\/\I I INMeo!/\/\/NH Me Y 0CH NH\/CH(XXIX.)(XXXIV.)A synthesis of norharmine on similar lines is foreshadowed.The necessity for using N-methylindole derivatives arises from thefact that the unmethylated compound gives rise to 5-keto-7-methyl-4 : 5-dihydroindolediazine( I : 4) (XXXIV).Norharmanalso results from the condensation of tryptophan with formalde-hyde in presence of sulphuric acid, followed by oxidation of theproduct :NH CH, NH\/\/NHSince harman (with which the alkaloids a r i b i ~ ~ e , ~ ~ loturine, and,4O Compare Ann. Rewrte, 1919, 16, 122.41 W. 0. Kermack, W. H. Perkin, jun., and R. Robinson, T., 1921,119,1602.42 E. Spiith, Monatah., 1919,40, 361; A., 1920, i, 327142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRI-.possibly, colloturinea have been identified) is obtained in asimilar manner by the use of acetaldehyde, the position of themethyl group in this and in harmine is determined.Evodiamine (XXXV) is broken down by boiling alcoholicpotassium hydroxide into N-methylanthranilic acid and a base.This is considered to be 3 : 4-dihydro-5-carboline (XXXVI),(XXXV.) (XXXVI.)/\I IM e y \ /HO-CH lco /\\/ + , MeHN!,!/\- Y --f /\-- C0,H 1 I I CH, i I lCH,*CH,*NH, \/\/NH\/\/\/NH CH,(XXXVII.)because “ isoevodiamine ” (XXXVII). (obtained from evodiamineby boiling with two per cent. alcoholic hydrochloric acid) issimilarly decomposed into N-methylanthranilic acid and a base,thought to be 2-@-aminoethylindole, since it yields 2-indolecarb-oxylic acid on fusion with potassium hydroxide.44 It has beenpointed outYP5 however, that the last piece of evidence is incon-clusive, since the same acid is one of the products of the alkalinefusion of scatole(3-methylindole), and, further, that it is improb-able that derivatives of 5- as well as of 4-carboline should occurnaturally.Laurotetanine is a phenolic secondary base, which readilyoxidises. It is converted by “nascent ” diazomethane into itsmethyl ether, but by preformed diazomethane into N-methyl-laurotetanine methyl ether, which is designated isoglaucine owing45 E. Spiith, Monateh., 1920, 41, 297; A., i, 50.44 Y. Asahina and S. Mayeda, J . Pham. SOC. Japan, 1916, No. 416;4 G W. 0. Kermack, W. H. Perkin, jun., and R. Robinson, Zoc. cit.A., i, 48ORQANIC CHEMISTRY. 143to its isomerism with, and similarity to, glaucine (XXXVIII) .46For this reason, and in view of the oxidation of laurotetanineto 1 : 2-dimethoxybenzene-3 : 4 : 5-tricarboxylic acid, the formula(XXXIX) is assigned to isoglaucine : 47Me01 \/OMe( XXXVIII. ) (XXXIX. )A more detailed account of the synthesis of ecgonine outlinedin last year’s Report has since been p~blished.*~A reinvestigation 49 of the degradation of scopoline by exhaustivemethylation has shown that it proceeds normally under very lowpressure if silver be excluded from solution. The product is nothowever, uniform, since a mixture of four dihydrodemethyl-scopolines is obtained by reducing it. One of these, a crystallinecompound, is unchanged by treatment with sodium methoxide,whilst from the oily mixture of the remaining three a product(XLIII) is obtained corresponding with O-methyl-iso-q-demethyl-scopoline. This is attributed to the presence in the original mixtureof the compound (XLII), corresponding in structure with +-de-methylscopoline :CH2-CH2-CH,1 1CH,-CH,-CH2I ICH-NMe, CH f- CH-NMe-C* --fI/O>lCH-----CH*OHCH2-CH2-CH2 CH2-CH2-CH2IC*NMe,ICH2 I I>OI ICH2I-0’1C-NMe, +CH-OH MeO-CH---CH CH----(XLII.) (XLIII.)Against the formula (XL) for scopoline it has been urged that46 Compare J. Gadamer, AT&. Phamn., 1911, 249, 680; A., 1912, i, 48.4 7 K. Gorter, Bull. Jam!. bot. Buitenzorg, 1921, [iii], 8, 180; A., i, 587.R. Willstlitter and M. Bommer, Annalen, 1921, 422, 15; A., i, 122.49 K. Hess, 2. angew. Chern., 1921, 34, 393; A., i, 683144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.when the oxygen bridge of E-scopoline is broken down by treat-ment with hydrobromic acid, the resulting product is inactive,although the asterisked carbon atom would retain its asymmetry.For this reason, formula (XLIV) is put f0rward.5~ This argument,however, loses much of its force from the fact that the same experi-menter found that cold chlorosulphonic acid also ruptures thebridge linking, and the hydroxyscopoline obtained by subsequenthydrolysis is ltworotatory.I NMe OH/-\OMehH---JkMe-bH /-3--CH2- \-/i CH,-C--CH,-AH-- CH*OH \ /\-/ \ I(XLIV.) OMe OMe(XLV.)It has hitherto been a matter of uncertainty as to which of thefour methoxyl groups in laudanosine is represented by a hydroxylgroup in laudanine. Since, however, ethyl- and ethylcarbonato-laudanjnes are respectively oxidised to S-ethoxy- and S-ethyl-carbonato-4-methoxybenzoic acids, it follows that the formula oflaudanine is represented by the formula (XLV).51The view that palmatine, one of the Colombo alkaloids, onlydiffers from berberine (XLVI) in that it contains two methoxy-groups in place of the methylenedioxy-grouping 52 has been con-firmed synthetically.63 By treatment of tetrahydroberberine withmethyl-alcoholic potassium hydroxide at 180", its two methoxy-and its methylenedioxy-groups were converted into four hydroxylgroups. The tetramethoxy-derivative prepared from this productby the aid of methyl sulphate was identical with tetrahydropal-matine, and was converted into palmatine itself by oxidation withalcoholic iodine solution. A methyltetrahydropalmatine (XLVII)has also been prepared from palmatine by the action of magnesiummethyl iodide, followed by reduction of the resulting a-methyl-dihydropalmatine. 54 The product is not identical with corydaline,so that this alkaloid cannot have the constitution (XLVII)previously assigned to it.55J. Gadamer, Arch. Pharm., 1921, 259, 110; A., i, 588.61 E. Spath, Monatsh., 1920, 41, 297; A., i, 50.62 K. Feist and G. Sandstede, Arch. Pharrn., 1918, 256, 1.63 E. Spath and N. Lang, Ber., 1921, 54, [B], 3064.64 Idem, ibid., 3074; A., 1922, i, 166.56 J. J. Dobbie and A. Lauder, P., 1902, 17, 252; J. Gadamer, .Arch.Pham., 1916, 254, 295; A., 1917, i, 472; H. Legerholtz, ibid., 1918, 256,729ORGANIC CHEMISTRY. 145(XLVI.) (XLVII.)By the action of sulphoacetic acid on papaverine, the sulphoacetateof a new base, coralyne, is obtained. This compound is so namedowing to its close relationship to the synthetic coralydine, intothe a-form of which it has been converted by r e d ~ c t i o n . ~ ~Passing reference may be made to a discussion of the mutualrelationships of the isoquinoline alkaloids. 57 Ethyl chloroformatepromises to be a useful reagent for the investigation of thesecompounds, since it has been found to break down the tetrahydro-isoquinoline ring, but to have Little effect on the dihydroindole,pyrrolidine, piperidine, and tetrahydroquinoline rings.58 Forexample, bulbocapnine (XLVIII) is converted into ethyl bulbo-capninecarboxylate (XLIX) :(XLVIII. ) (XLIX.)In the morphine group, attention is being concentrated on astudy of the various reduction products obtainable from thebaineand codeine, and their derivative^.^^J. KENNER.66 W. Schneider and K. Schroeter, Ber., 1920, 53, [B], 1459; A., i, 760;5 7 J. W. D. Hackh, Chem. News, 1921,123,178; A., i, 800.5 8 J. Gadamer and F. Knoch, Arch. Phamn., 1921,259, 135; A., i, 579.69 C. M a d & and (Miss) H. Lowenheim, ibid., 1920,258, 295; M. Freudand E. Speyer, Ber., 1920, 53, [ B ] , 225; A. Skita, ibid., 1921, 54, [B], 1560;E. Speyer and S. Siebert, ibid., 1519; E. Speyer and others, D.R.-P. 338147;A., i, 124, 125, 684, 685, 803.W. Schneider and A. Kohler, ibid., 1921, 54, [B], 2031; A., i, 803

ISSN:0365-6217    

DOI:10.1039/AR9211800060

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THE analytical work published during the past year has beengreater in volume and more diverse in character than in any otheryear since the outbreak of the war. Hence, in order to confinea, general survey within the space available, it has been necessaryto make a selection from the more important contributions, andto omit many which would otherwise have received notice.Physical Methods.The influence of adsorption on the accuracy of analytical resultshas been demonstrated in a series of papers. For example, filter-paper adsorbs a considerable proportion of lead, and smaller amountsof copper and silver. The main cause of this is the mineral matterin the paper, and the presence of an acid solution (that is, hydrogenions) prevents the ads0rption.l The amount of acid adsorbed byfilter-paper is equivalent to the alkalinity of the ash.2 The amountsof alkali taken up are directly proportional to the alkalinity of thesolution; but in this case there is no true ad~orption.~ The re-moval of heavy metals by cellulose is due to a chemical reaction,and is not a physical pro~ess.~ The use of impure asbestos leadsto error owing to the adsorption of positive ions.Advantage maybe taken of this fact for the estimation of lead in water.5 Theabsorption of salts of metals or of alkaloids by glass-wool appearsto be due to the alkalinity of the glass, and the loss may be con-siderable if this material is used for the filtration of hot solutions.6Reference may also be made, in this connexion, to the influenceof the glass of certain bottles of recent manufacture on standardacid and other solution^.^Several new methods of analysis have been based on the deter-mination of the temperature of miscibility of two or more liquids.For example, the alcoholic strength of aqueous alcohol may berapidly ascertained by mixing the liquid with acetone or light1 I.M. Kolthoff, Pharm. Weekblad, 1920, 57, 1510; A., ii, 19.2 Idem, ibid., 1571; A., ii, 123.3 Idem, ibid., 1921, 58, 46; A., ii, 213. Idem, ibid., 233; A., ii, 277.5 Idem, ibid., 401; A., ii, 344. Idem, ibid., 463; A . , ii, 409.C. A. Mitchell, Analyst, 1921, 48, 129.14ANALYTICAL CHEMISTRY. 147petroleum,* and in the case of ternary mixtures, such as alcohol,ether, and water, the composition may be found from the quantityof water reqqired to produce turbidity, or of ether to obtain a clearl i q ~ i d .~ Similarly, the critical temperature of solution in anilineof light petroleum, before and after nitration, affords a measureof the hydrocarbons present.1° The lowering of the temperaturea t which a mixture of hydrocarbons and aniline separates into twolayers, after sulphonation, corresponds directly with the proportionof aromatic hydrocarbons in the mixture.llThe use of nephelometric methods has been extended in severaldirections, and a new type of nephelometer has been constructed,in which the height of a standard Tyndall cone is measured in theliquid under examination and in a standard solution. In all suchmeasurements, it is essential that the particles of the turbid liquidshould be of uniform size.l2 For certain biochemical estimations,the turbidimeter of Folin and Denis l3 is preferable to the nephelo-meter.14An addition to the numerous applications of refractometry inanalytical work has been published, the principle having beenadapted to the calculation of the proportions of salts in an aqueoussolution. 15For the spectroscopic examination of mixtures, the use of theX-ray spectrum has the advantage of relative simplicity as com-pared with the ordinary spectrum. A vacuum spectrograph hasbeen devised, by means of which photographs of the lines of allthe elements may be readily obtained.16There have not been many contributions to the methods ofdetermining viscosity, but reference may be made to the cup-and-ball viscosimeter, in which the time before a ball falls from aninverted cup in which a drop of the oil has been placed is measured.This gives results comparable with those obtained with standardapparatus.178 H.Rosset, Ann. Chim. anal., 1921, [ii], 3, 235; A., ii, 598.9 L. Desvergnes, Mon. Sci., 1921, 11, 145; A., ii, 601.lo G. Chavanne and L. J. Simon, Ann. Chim. anal., 1921, [ii], 3, 87; A.,l1 H. T . Tizard and A. G. Marshall, J . SOC. Chem. Ind., 1921, 40, 2 0 ~ ;l2 H. Kleinmann, Kolloid Z . , 1920, 27, 236; A., ii, 56.13 0. Folin and W. Denis, J . Biol. Chem., 1914, 18, 263; A , , 1914, ii, 687.l4 W. Denis, ibid., 1921, 47, 2 7 ; A., ii, 555.15 C. A. Clemens, J . Ind.Eng. Chern., 1921, 13, 813; A., ii, 650.l6 M. Siegbahn, A. E. Lindh, and N. Stensson, 2. Phyaik, 1921, 4, 61;l7 T. C. Thomsen, Report of Lubrication Inquiry Committee, Dept. Scientificii, 354.A., ii, 280.A., ii, 344.and Ind. Reeearch,"l920, 15-16, 103148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A new instrument for determining the surface tension of liquidsfrom the rise in capillary tubes has been devised, and is intendedespecially for cases where only a small amount of the liquid isavailable.l*Gas Analysis.Several new forms of apparatus for use in gas analysis havebeen designed. One of these is an absorption vessel the stopperof which is hollow and has a perforated extension reaching nearlyto the bottom of the flask, and the gas is made to pass throughthis stopper on its way through the ab~0rbent.l~ Another apparatusis a gas-volume compensator, by means of which the volume of aconstituent absorbed from a gas may be obtained with an accuracyof within 0.5 per cent.from the reading shown on a manometer.20A new method for the estimation of microscopically smallquantities of gas has been based on the consecutive determinationof the condensation temperature of each gas when cooled in theside tube of a Pirani gauge. In practice, the results are comparedwith those obtained with a series of gauges each containing a puregas, and the respective amounts are found by reference to graphs.21The methods principally used for the estimation of small quantitiesof carbon monoxide in air are those based on its oxidation by meansof iodic anhydride,22 and on its conversion into carboxyhBmo-g10bin.~~ Elimination of the influence of other gases reacting withiodic anhydride is not always easy; for this reason, the secondmethod is often preferable, but air containing more than 0.1 percent.of carbon monoxide must be diluted before being passedthrough the hemoglobin solution.24A reagent termed " Hoolamite " (U.S. Pats. 1321061-2) consistsof a mixture of iodic anhydride, fuming sulphuric acid, and pumicestone. The carbon dioxide formed in the oxidation of 'thecarbon monoxide reacts with the excess of sulphur trioxide to forma green compound, and the intensity of the coloration, when com-pared with special colour standards, affords a measure of the carbonmonoxide.The method is applicable to gases containing up to0.2 per cent. of carbon monoxide.2518 S. Sugden, T., 1921, 119, 1483.19 Walz, Chem. Ztg., 1921, 45, 658; A., ii, 515.20 R. S . Tour, Chern. Met. Eng., 1920, 23, 1104; A., ii, 125.21 Research Staff, Gen. Electric Co., Ltd. (W. R. Campbell), Proc. PhysicalSoc., 1921, 33, 287; A., ii, 591.22 A. Gautier, Compt. Tend., 1898, 126, 793; A., 1898, ii, 537.23 J. Ogier and E. Kohn-Abrest, Ann. Chim. anal., 1908, 13, 169; A.,24 D. Florentin and H. Vandenberghe, Cornpt. rend., 1921, 172, 391; A.,1908, ii, 631.ii, 276.C. R. Hoover, J . Ind. Eng. Ohm., 1921,13, 770; A., ii, 664ANALYTICAL CHEMISTRY. 149Two modifications of the Pettenkofer method of estimatingcarbon dioxide in air have been devised, the gas in each case beingabsorbed by standard sodium hydroxide solution, the excess ofwhich is subsequently titrated.26A gravimetric method of estimating nitrous fumes in air, etc.,has been based on the formation of an orange precipitate when asolution of a nitrite is heated a t 50" first with a solution of p-nitro-aniline and then with an alkaline solution of a~naphthol.~~The fact that iodine converts metals such as silver, copper, oraluminium into iodides a t the ordinary temperature has beenutilised for the detection of chlorine in air. When a sheet of silverforming part of an electric circuit is covered with damp potassiumiodide any chlorine present in the air will liberate iodine, whichwill then combine with the metal, and break the electric circuit;this may be notified audibly by the addition of a suitable device.28It has been shown that adsorption of small quantities of benzenehydrocarbons in coal gas by means of charcoal, and their subsequentdistillation with steam, give more accurate results tlhan are obtain-able by the dinitrobenzene or paraffin methods.29Agricultural Analysis.Various methods for the estimation of colloidal material in soilhave been published.One of these, depending on a physicalseparation of " ultra clay " by centrifugal action, gave results inagreement with those calculated from the absorption of dryammonia by the soiL3OConsiderable attention has also been directed to the estimationof hydrogen-ion concentration as an indication of the lime require-ment of soils.A convenient colorimetric method has been devised,and in using this for estimating the lime requirement increasingquantities of barium hydroxide are added to the soil, prior to theextraction, a curve plotted of the successive hydrogen-ion con-centrations, and the amounts of barium hydroxide calculated intocalcium 0xide.~1The method of estiinatirig soil acidity by the liberation of iodinefrom a solution of potassium iodide and iodate32 has been shownto be influenced by too many factors to be really tr~stworthy.~~26 J. Freund, 2. Hyg., 1920, 91, 218; A., ii, 348.2 7 J. Moir, J . S. African. Assoc. Anal. Chem., 1921, 4, 3 ; A., ii, 345.28 C. Matignon, Compt. rend., 1921, 172, 532; A., ii, 272.Z9 E.Bed, K. Andress, and W. Mirller, 2. angew. Chem., 1921, 34, 125;30 C. J. Moore, W. H. Fry, and H. E. Middleton, J . Ind. Eng. Chem., 1921,31 E. A. Fisher, J . Agric. Sci., 1921, 11, 45; A., ii, 349.a2 A. Stutzer and W. Haupt, J . Landw., 1915, 63, 33; A., 1915, ii, 655.33 0. Lemmermm and L. Fresenius, ibid., 1921, 69, 97; A., ii, 516.A., ii, 272.13, 527; A., ii, 608150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A new method of estimating potassium in soils, even in thepresence of considerable amounts of sodium salts, depends on itsprecipitation as cobaltinitrite, and measurement of the volume ofthe precipitate.34 The method of Folin and Macallum35 does notgive accurate results unless the soil is suspended in a saturatedsalt s0lution.3~A rapid test for readily-soluble phosphates in soils is based onthe extraction of the air-dried sample with standard nitric acid,precipitation of the phosphate with ammonium molybdate at 60°,and measurement of the amount of the pre~ipitate.~~Apparently the presence of other salts in the soil retards theprecipitation of the magnesium ammonium phosphate in theestimation of citric-soluble phosphate, and the liquid shouldtherefore be left over-night before filtrati~n.~'A micro-Kjeldahl method, which enables nitrogen to be estim-ated in a few mg.of material, has been described; methyl-red isused as the indicator in the t i t r a t i ~ n . ~ ~For the estimation of ammoniacal nitrogen in fertilisers con-taining calcium cyanamide and ammonium salts, the solution istreated with sodium hydroxide and a current of air aspiratedthrough it into standard acid for about seven hours a t the ordinarytempera t ure , 39A direct method of estimating dicyanodiamide in mixed fertilisersdepends on its precipitation with silver picrate, which does not givea precipitate with cyanamide or carbamide.*O An analogpusmethod has been based on the precipitation of a compound of2 mols.of dicyanodiamide with 1 mol. of silver picrate, whilstcarbamide and dicyanodiamidine are not precipitated. Dicyano-diamide also forms similar silver complexes with soluble nitro-phenols, such as the silver salt of trinitroresorcinol, which giveseven more accurate results than silver p i ~ r a t e .~ ~The principle may also be used as the basis of a volumetricprocess, the excess of silver remaining after the precipitation ofthe complex silver picrate dicyanoguanidine being titrated.4234 0. Arrhenius, Medd. K. Vetenskapalcad., Nobel-Inat., 1920, 4, 1 ; A.,35 0. Folin and A. B. Macallum, J . Biol. Chem., 1912, 11, 523; A., 1912,36 0. M. Shedd, Soil Sci., 1921, 11, 111; A., ii, 274.37 P. Muller, Chem. Ztg., 1921, 45, 178; AI, ii, 275.38 W. Geilmann, J . Landw., 1920, 68, 235; A., ii, 128.39 J. Froidevaux and H. Vandenberghe, Ann. Chim. anal., 1921, 3, 146;40 1%. N. Harp-, J . Ind. Eng. Chem., 1920, 12, 1107; A., ii, 224.41 E. B. Johnson, J . SOC. Chem. Ind., 1921, 40, 125; A., ii, 468.ii, 412.ii, 683.d., ii, 462.Idem, J . Ind. Eng.Chew&., 1921, 13, 533; A., ii, 605ANALYTICAL CHEMISTRY. 151Carbamide in fertilisers may. be accurately estimated by pre-cipitation as carbamide oxalate, which is then purified, dried underreduced pressure, and weighed.42Organic Analysis.Qualitative.-Some new sensitive colour reactions with alkalinephenylhydrazine hydrochloride solution containing metal or diazo-benzenesulphonic acid have been devised for the identification offormaldehyde and a~etaldehyde.~a Resorcinol with sulphuric acidis also a very sensitive reagent for formaldehyde after separationin a current of steam.44 In this way, the test may be used in thepresence of tartaric and oxalic acids, which also give colorationswith the reagent .45Further work has been done on the identification of organicacids by conversion into their phenacyl esters, which are thenseparated by fractional cry~tallisation.~~Lactic acid gives a characteristic red coloration with alcoholicguaiacol solution, and may thus be distinguished from formic,acetic, malic, benzoic, salicylic, and certain other acids!'A method for the detection of free tartaric acid in wines hasbeen based on its partial extraction with amyl alcohol, in whichpotassium hydrogen tartrate and calcium tartrate are insoluble.48The biochemical process of detecting dextrose 49 has been founda suitable means for the examination of plant materiaL5* Areagent giving a brown coloration with woody fibre and withvanillin consists of a solution of vanadium pentoxide in phosphoricacid solution; it may be used as a microscopic test.51Phenol may be identified by giving a characteristic, coloured zonewhen mixed with sodium nitrite solution and poured on to thesurface of sulphuric acid.52A test capable of detecting 1 part of fluorescein in 200,000,000parts consists in acidifying tlhe solution with sulphuric or hydro-chloric acid, shaking it with ether, and, after separation of the42 E.B. Johnson, J . Ind. Eng. Chem., 1921, 13, 533; A . , ii, 605.43 E. Pittarelli, Arch. Fawn. Sperint. Sci. Ag., 1920, 30, 148; A., ii, 222.44 R. Cohn, Chem. Ztg., 1921, 45, 997; A., ii, 663.4 5 E. Krausz and H. Tampke, ibid., 521 ; A . , ii, 466.4 6 J. B. Rather and E. E. Reid, J . Amer. Chem. SOC., 1021, 43, 629; 9.,4 7 E. Hartwiq and R.Saar, Chem. Ztg., 1921, 45, 322; A., ii, 356.4 R L. Mathieu, Ann. Falsif., 1021, 14, 281; A . , ii, 662.49 Compare Ann. Reports, 1920, 17, 138.M. Bride1 and R. Arnold, Conzpt. rend., 1920, 172, 1434; A., ii, 463.51 J. Gruss, Ber. Deut. bot. Ces., 1921, 38, 361; A., ii, 284.52 G. Rodillon, J . Pharm. Chim., 1921, [vii], 23, 136; L4., ii, 282.ii, 356. Compare A . , 1920, i, 381152 ANNUAL REPORTS ON W E PROGRESS OF CHEMISTRY.ethereal layer, adding a few drops of ammonia, when a greencoloration is produced when fluorescein is present. 53The green coloration produced by concentrated sulphuric acidwith certain lactic and cinnamic acid derivatives is due to theformation of indones, which combine with the sulphuric acid,whereas hydrindones do not give the reaction.It is possible inthis way to distinguish between stable cinnamic acids and allo-compounds.54Methods of distinguishing between volatile alkylamines andammonia, and between volatile tertiary and primary or secondaryalkylamines have been based on their respective behaviour withformaldehyde, and with potassium mercuric iodide. 55Glycine anhydride, creatinine, and some allied compounds givea coloration when heated with picric acid ; 'this reaction, however,is also given by numerous other s~bstances.~~It has been shown the thalleioquinine reaction is most sensitivewhen the proportion of bromine is as 6 atoms per molecule ofquinine; it is capable of detecting 1 part of the alkaloid in 250,000parts.6'Theobromine may be distinguished from caffeine by the differ-ences in the colorations produced when the respective bismutho-iodides are reduced by means of hydriodic acid.58Hitherto no definite colour reaction of aconite has been known,but it has recently been shown that aconitine, or at all events$-aconitine, the alkaloid in Indian aconite, gives a distinctivegreen coloration with potassium ferricyanide and formic acid.59A new method of distinguishing between ouabain and strophantiilis based on the difference in the behaviour of the two glucosideswhen warmed with hydrochloric acid and resorcinol.Strophantingives a rose coloration, whilst ouabain gives no coloration, thisdifference being due to the action of the respective sugars formedin the hydrolysis.60No distinctive test for vitamins has yet been discovered, but ithas been found that some constituent of antiscorbutic extracts,possibly a polyphenol readily detached from a vitamin, gives a bluecoloration with a sulphuric acid solution of sodium tungstate,63 M.Lombard, Bull. SOC. chim., 1921, [iv], 29, 462; A., ii, 528.64 R. de Fazi, Gazzetta, 1921, 51, i, 164; A., ii, 357.6 5 H. E. Woodward and C. L. Alsberg, J . Biol. Ghem., 1921, 46, 1 ; A.,66 T. Sasaki, Biochem. Z., 1921, 114, 63; A., ii, 358.5 7 W. B. Hart, J . SOC. Chem. Ind., 1921, 40, 7 2 ~ ; A., ii, 359.s* M. Malmy, J . Pharrn. Chim., 1921, [vii], 23, 89; A., ii, 360.59 S. Mallaneh, Analyet, 1921, 46, 193; A., ii, 470.A. Richaud, J . Pham. Chim., 1921, 24, 161; A., ii, 601.ii, 358ANALYTICAL CHEMISTRY, 153phosphomolybdic acid, and phosphoric acid. Extracts which donot possess antiscorbutic properties do not give this coloration,which, however, is also produced by quinol.61Quantitative.-Two new types of combustion furnace have beendesigned, one of which has many advantages over the ordinaryfurnace,62 whilst the other is a compact micro-furnace, which canalso be used for the estimation of nitrogen.63A new method for the estimation of enols has been based on thefact that they form complex copper salts which are soluble inchl~roforrn,~~ but it has been shown that the method is onlyapplicable to a very limited number of cases.65Simple volatile alcohols may be estimated by esterification withlauryl chloride, extraction of the ester with ether, and its hydrolysiswith potassium hydroxide, but the method is not satisfactory withsecondary alcohols of the type of menthol.66A rapid method of estimating ethyl alcohol is to add anilineand to titrate the liquid with water until a permanent turbidityresults, the volume of alcohol being then found by reference to agraph.G7For the estimation of ethyl acetoacetate advantage has beentaken of the fact that the ester reacts with sodium sulphite, withthe liberation of sodium hydroxide, which is subsequently titrated.68It has been shown that the accuracy of the iodometric method ofestimating acetone depends mainly on the proportion of potassiumhydroxide added to the solution.69A new method of estimating glycerol in wines depends on itsconversion into acraldehyde by means of boric acid, and estimationof the distilled aldehyde by means of standard silver nitratesolution.70There have been but few additions to the methods of analysingoils and fats, but it has been shown that propyl alcohol is a usefulmedium for obtaining complete substitution in the determinationof the bromine-substitution value.71 A simple and trustworthyformula for calculating the acetyl value from the saponificationG1 N. Bezssonoff, Compt. rend., 1921, 173, 466; A., ii, 608.G2 T. J. Hedley, T., 1921, 119, 1242.G3 W. Dautwitz, Chem. Ztg., 1920, 44, 963; A., ii, 131.G4 W. Hieber, Ber., 1921, 54, [B], 902; A . , ii, 466.6 5 W. Dieckmann, ibid., 2251; A., ii, 716.6 6 A. Griin and T.Wirth, 2. Deut. Oel-Fett Ind., 1921, 41, 145; A., ii, 660.O 7 A. Lachman, J. I n d . Eng. Chem., 1921, 13, 230; A., ii, 355.Ga H. Yanagisawa, J. Pharm. SOC. Japan, 1921, 240; A., ii, 418.69 P. H. Hermans, Chem. Weekblad, 1921, 18, 348; A., ii, 467.70 A. Heiduschka and F. Englert, 2. anaZ. Chem., 1921,60, 161 ; A,, ii, 524.71 E. Schulek, Pham. Zentr.-h., 1921, 62, 391; A,, ii, 603154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.values of a fat before and after acetylation has been worked 0~t,72and a more exact method of separating solid from liquid fattyacids in the form of their lead salts has been devised.73The conditions under which cholesterol and allied substancesmay be accurately estimated have been studied, and the colori-metric method has been shown to be inapplicable to the unsaponi-fiable matter ofA new measure for the activity of amylase solutions has beenrecommended as giving more absolute values--Xj'= K x maltose(in grams)/enzyme preparation (grams), where K represents theconstant of the unimolecular reaction during the first part of thehydrolysis.In using taka diastase for the estimation of starch, the resultsvary with the origin of the enzymic preparation, and it is thereforenecessary to make control experiments on pure starch with eachenzyme.76An iodometric method of estimating the diastatic capacity ofmalt has been based on the oxidation of the resulting maltose tomaltobionic acid by means of an alkaline solution of iodine, theamount of iodine required affording a measure of the maltose.77The conditions under which dextrose is quantitatively oxidisedby alkaline permanganate have also been ascertained and adaptedto the estimation of starch and dextro~e,'~ and the same principlehas also been used for the estimation of lactose.79Laevulose, like other sugars and polyhydric alcohols, combineswith boric acid to form an acid compound, and the proportion ofboric acid entering into combination affords a means of estimatingthat sugar.8oA new volumetric method of estimating reducing sugars involvesthe use of an alkaline solution of potassium ferricyanide standard-ised against pure dextrose.81 The process may be used forthe estimation of dextrose formed in the hydrolysis of certainglucosides .8272 E.Andre, Compt. rend., 1921, 172, 984; A., ii, 419.73 E. Twitchell, J . Ind. Eng. Chem., 1921, 13, 806; A., ii, 662.74 J. A. Gardner and M. Williams, Biochem. J . , 1921, 15, 363, 376 ; A.,7 5 H. von Euler and 0. Svanberg, 2. physiol. Chem., 1921, 112, 193; A.,7 6 E. Horton, J . Agric. Sci., 1921, 11, 240; A., ii, 661.7 7 J. L. Baker and H. F. E. Hulton, Analyst, 1921, 46, 90; A., ii, 420.7 8 F. A. Quisumbing, Philippine J . Sci., 1920, 16, 581; A,, ii, 67.79 F. T. Adriano, ibid., 1920, 17, 213; A., ii, 284.G. van B. Gilmour, Analyst, 1921, 46, 3 ; A., ii, 221.81 A. Jonescu and V. Vargolici, Bul. SOC. Chim. Rodnia, 1920, 2, 38;ii, 563.ii, 528.A., ii, 283. 82 A. Jonescu, ibid., 1921, 3, 6 ; A., ii, 525ANALYTICAL CHEMISTRY. 155A colorimetric method of estimating dextrose in urine has beenbased on the fact that when heated in the presence of sodiumcarbonate it reduces 4 : 6-dinitroguaiacol to 4-nitro-6-aminoguaiaco1,which has an intense c o l o ~ r .~ ~Another suitable reagent for the colorimetric estimation ofdextrose is 3 : 5-dinitrosalicylic acid.84An iodometric method of estimating phenylhydrazine has beendevised, and adapted to the estimation of pentosans and p e n t o s e ~ . ~ ~L~vulic acid in foods may be estimated by oxidation with di-chromate and sulphuric acid, and distillation and titration of tberesulting acetic acid. Formic, acetic, and lactic acids must firstbe separated from the original substance.86For the separation of aliphatic amines, advantage has beentaken of the solubility of ammonium chloride and monomethylaminehydrochloride in chloroform.The ammonia may then be separatedby treatment with yellow mercuric oxide, whilst trimethylaminemay be separated from dimethylamine by converting it into itsperiodide.An accurate method of titrating aniline involves diazotisationwith standard sodium nitrite solution, pota,ssium iodide-starchpaper being used as outside indicator.88Better results are obtained in the titration of certain alkaloidsby using bromophenol-blue in place of the usual indicators, whilstmethyl-red is the most suitable indicator for quinine hydrogen~ a l t s . 8 ~Theobromine can be separated in a very pure condition by meansof a method in which tetrachloroethane is used for the extraction.90Inorganic Analysis.Qualitative.-The applications of spot reactions on filter-paperas a preliminary test have been systematised, and attention hasbeen directed to the use of the reactions of aluminium, uranium,and chromium with alizarin colouring matters and of manganesewith benzidine .glIt has been shown that sodium thioantimonate is a useful general83 J.B. Sumner, Physiol. Abstr., 1921, 6 , 170; A . , ii, 526.84 J. B. Sumner and V. A. Graham, J . BioZ. Chem., 1921, 47, 5 ; A., ii, 564.8 5 A. R. Ling and R. D. Nanji, Biochern. J., 1921,15, 466; A . , ii, 601.8 6 L. Griinhut, 2. Unters. Nahr. Genussm., 1921, 41, 261; A., ii, 602.87 H. Franzen and A. Schneider, Biochem. Z., 1921, 116, 195; A., ii, 663.** T. Sabalitscka and H.Schrader, 2. anal. Chem., 1921,34,45; A . , ii, 224.139 N. Evers, Pharrn. J., 1921, 106, 470; A., ii, 527.91 F. Feigl and R. Stern, 2. anal. Chern., 1921, 60, 1 ; A., ii, 279.R. V. Wadsworth, Analyst, 1921, 46, 3 2 ; A., ii, 225156 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.reagent for certain metals. I n the case of mercury, the colour ofthe precipitate varies with the particular sak.92A delicate test for the hydrides of arsenic, antimony, and phos-phorus has been based on the fact that they produce a violetcoloration on sodium aurochloride t e ~ t - p a p e r . ~ ~As little as 0.00000034 gram of gaseous ammonia may be de-tected by the film-mirror which it produces on a drop of silvernitrate solution containing 3 per cent. of f~rmaldehyde.~~ Anothernew test for ammonia depends on its conversion into hexamethylene-tetramine picrate, which forms characteristic, microscopic crystaIs.95Several tests for individual metals will be found useful in system-atic analysis.A reaction capable of detecting mercury in asolution of 2 mg. per litre depends on the formation of cuprousmercuric iodide; it is applied in the form of t e ~ t - p a p e r . ~ ~Bettendorff's reagent (stannous chloride in hydrochloric acid) iscapable of detecting 0-01 mg. of arsenic trioxide; in the case ofdark solutlions, the arsenic is first evolved as hydrogen ar~enide.~'A method of detecting antimony in the presence of tin is basedon its precipitation from hydrochloric acid solution as red oxy-sulphide by means of sodium thiosulphate solution, whereas stannicchloride gives a white precipitate of sulphide and hydroxide.Cupricsalts must be removed before applying the test.98Aluminium, iron, chromium, and manganese may be detectedby the form and colour of their crystalline compounds with salicylicacid.99A new and sensitive reagent for the detection of cobalt is cithera nitroso-compound or an oxamino-compound, which is preparedby heating an acidified solution of R-salt (sodium F-naphthol-3 : 6-disulphonate) with sodium nitrite. Its aqueous solution forms agreen compound with ferrous salts, a brownish-yellow compoundwith nickel, and a deep red dye with coba1t.l Iron and cobaltmay also be distinguished from nickel by the colorations given bytheir salts with dimethylglyoxime solution and ammonia.2Comparative tests of the sensitiveness of the ordinary reagentsfor barium ion have shown that sulphuric and chromic acids are92 A.Langhans, 2. anal. Chem., 1921, 60, 91; A., ii, 353.93 W. Zimmermann, Apoth. Ztg., 1921, 36, 29; A., ii, 276.95 C. Collo and V. Teodossiu, Bul. SOC. Chim. Romania, 1920, 2, 100; A.,96 P. Artmann, 2. anal. Chem., 1921, 60, 81; A., ii, 350.9 7 L. W. Winkler, Phurm. 2entr.-h., 1921, 62, 125; A., ii, 275.9 8 V. Njegovan, Chem. Ztg., 1921, 45, 681; A., ii, 563.S9 C. van Zijp, Pharm. Weekblad, 1921, 58, 694; A., ii, 463.H. S. van Klooster, J . Amer. Chem. SOC., 1921, 43, 746; A., ii, 415.2 W. Vaubel, I;. dflentl. Chem., 1921, 27, 163; A., ii, 596.C . D. Zenghilis, Compt.rend., 1921, 173, 153; A., ii, 558.ii, 214ANALYTICAL CEEMISTRY. 157the most sensitive (1 : 1,600,000 and 1 : 1,200,000) and sodiumarsenate the least sensitive (1 : 175).3A simple method of detecting sodium and potassium in thepresence of magnesium depends on the formation of the compoundK,CUP~(NO,)~, which crystallises in microscopic, black cubes, andof sodium pyroantimonate, which also has a characteristic micro-scopic appearan~e.~The reaction between azoimide and nitrous acid-HNO, +HN, = H20 + N,O + N2-has been applied to the detection ofnitric acid in the presence of nitrous acid, the latter being thusremoved before testing for the f ~ r m e r . ~In applying the diphenylamine test, it is necessary to have adefinite concentration of the liquid, and this is best found by addingsuccessive quantities of water.&zcantitative.-Guandine carbonate, being non-hygroscopic, isa convenient substance to use for the standardisation of acidsolutions.7 Another original standard, which gives trustworthyresults in alkalimetry, is potassium hydrogen oxalate.8Two new forms of apparatus for colorimetric estimations havebeen devised.OIn using cresol-red as indicator in determinations of hydrogen-ion concentration a correction is necessary for the presence ofsalt.10 Some indicators are too sensitive for certain estimations,such as the titration of an alkali acetate with an acid; in suchcases, tropzeolin-0 and -00 may be serviceable.ll By using twoindicators simultaneously it is possible to titrate many colouredsolutions with accuracy,12 and in some cases, where this method isnot applicable, the colouring matter may be bleached with hydrogenperoxide.laWhen only small amounts of solution are available, indicatorpapers may be used in presence of a buffer s01ution.l~The new indicators described include a compound prepared by3 0.Lutz, 2. anal. Chem., 1921, 60, 209; A., ii, 596.E. Ludwig and (Mlle) H. Spirescu, Bul. Soc. Chim. Romania, 1920, 2,78; A., ii, 215.5 E. Oliveri-Mandala, Gazzetta, 1921, 51, i, 138; A., ii, 346.6 A. E. Weinhagen, J. Amer. Chem. Soc., 1921, 43, 685; A., ii, 346.A. H. Dodd, J. SOC. Chem. h d . , 1921, 40, 8 9 ~ ; A., ii, 409.8 Y. Osaka and K. And& J. Tokyo Chem. SOC., 1920, 41, 945; A., ii, 132.9 E.Alstone, Soil Sci., 1920, 10, 467; A,, ii, 214. N, Evers, Analyst,10 R. C. Wells, J. Amer. Chem. SOC., 1920, 42, 2160; A., ii, 55.11 I. M. Kolthoff, 2. anorg. Chem., 1921, 115, 168; A., ii, 465.l2 J. L. LiZius, Analyst, 1921, 46, 355; A., ii, 650.13 C. A. Mitchell, ibid., 131.14 I. M. Kolthoff, P h m . Weekblad, L92P, 58, 961; A., ii, 515.1921, 46, 392; A., ii, 705158 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the interaction of ethyl nitrate and magnesium phenyl brornide,l5and two new phthaleins, one of which is unaffected by excess ofalkali or alcohol; both are available between Pa 8.9 and 10.2.16There have been but few additions to the general methods ofoxidation or reduction. Itxhas been shown, however, that theaddition of manganese sulphate accelerates the reaction betweenpotassium permanganate and hydrogen peroxide or sodium oxalate.17A sharp method of titrating arsenious compounds with standarddichromate solution is to add potassium bromide and hydrochloricacid, and to pass a current of air through the liquid.The bromineliberated by the first drop in excess of dichromate is carried over intopotassium iodide solution and the liberated iodine indicated bymeans of starch.18 An analogous method may be used for thetitration of ferrous salts with permanganate solution.19An oxidimetric method of estimating manganese in hydrofluoricacid solution by means of potassium permanganate has been shownto give results as accurate as those obtained by other volumetricprocesses.20A volumetric method of estimating mixtures of permanganate,dichromate, and chromic salts is based on the fact that perman-ganate is converted into hydrated manganese dioxide by the actionof manganese sulphate and zinc sulphate, whilst dichromate isunaffected. By titrating the liquid with ferrous sulphate solutionbefore and after this treatment, the amounts of the two substancesare found.21For the estimation of traces of hydrogen peroxide, ferrous sulphateis used as the reducing agent, and the resulting ferric sulphateestimated colorimetrically.22Mention may also be made of a volumetric method of estimatinghyposulphite depending on its reducing action on potassiumf erricyanide .23The use of cadmium has been recommended in place of zinc forthe reduction of ferric salts, since it obviates the risk of iron beingdeposited when insufficient iron is present .24 Quadrivalent titaniumis also quantitatively reduced by cadmium, and it is therefore1 5 R.W. Kinkead, Chem. News, 1921, 122, 4 ; A . , ii, 124.16 W. CsBnzi, Z. Elektrochem., 1921, 27, 64; A., ii, 270.17 P. H. Segnitz, J . Ind. Eng. Chem., 1920, 12, 1196; A., ii, 125.18 R. Meurice, Ann. Chim. anal., 1921, 3, 85; A . , ii, 85.19 R. Meurice, ibid., 23; A., ii, 218.20 J. Holluta and J. Obrist, Monatsh., 1921, 41, 555; A . , ii, 522.2 1 N. G. Chatterji, Chem. News, 1921, 123, 232; A . , ii, 713.22 F. W. Horst, Chem. Ztg., 1921, 45, 572; A., ii, 461.23 R. Formhals, ibid., 1920, 44, 869; A . , ii, 58.24 W.D. Treadwell, Helv. Chim. Acta, 1921, 4, 551; A . , ii, 523ANALYTICAL CHEMISTRY. 159possible to estimate iron and titanium simultaneously by firstreducing the solution, and then titrating it with ~ermanganate.~~Several new iodometric methods have been published duringthe year. When titrating an excess of iodine in acid solution withthiosulphate solution, a sharper end-point may be obtained byadding thiosulphate so as to prevent the ionic concentration of theiodine.26Lead may be accurately estimated as chromate by iodometricestimation of the excess of chromate in the filtrate from the lead~hromate.~' For the iodometric estimatioii of iron it is essentialto have definite concentrations of acid and potassium iodide, anda limit for the proportion of iron.28An iodometric method of estimating chromium in chromite 29has been devised; and new methods of estimating iodides in thepresence of iodates,30 and thiosulphates in the presence of sulphitesand tetrathionates,31 also involve iodometric processes.Turning next t o the methods of separating metals, we find animportant investigation of the conditions under which zinc, cadmium,manganese, and silver may be estimated by volatilising theirsulphides in a current of dry hydrogen ~ u l p h i d e .~ ~The use of hypophosphorous acid in gravimetric analysis has alsobeen studied, and methods have been devised for its use in separatingsilver from platinum and other metals.s3Mercuric chloride can be completely volatilised from its solutionin a current of hydrogen chloride, and the principle has been adaptedt o the separation of mercury from copper, cadmium, iron, and otherelements .34Two new volumetric methods of estimating mercury have alsobeen described.35Gravimetric methods for the estimation of cadmium have beenbased on its precipitation as sulphide containing salphate25 W.D. Treadwell and A. Rheiner, loc. cit.26 B. Kohler, Chem. Listy, 1920, 14, 137, 195; A., ii, 410.2 7 C. W. Simmons, J. R. Gordon, and H . C. Boehmer, Cunad. Ghem. J . ,2 8 I. M. Kolthoff, Pham. Weekblad, 1921, 58, 1510; A . , ii, 713.29 E. Little and J. Costa, J . Ind. Eng. Chem., 1921, 13, 228; A., ii, 351.31 A. Kurtenaclrer and A. Fritsch, 2. anorg. Chem., 1921, 117, 262; A.,32 L. Moser and A.Schattner, Chem. Ztg., 1921, 45, 758; A., ii, 558.33 L. Moser and T. Kittl, 2. unal. Chem., 1921, 60, 145; A . , ii, 521.34 W. Strecker and K. Conradt, Ber., 1920, 53, (231, 2113; A., ii, 64.35 E. Biilmann and K. Thaulow, Bull. SOC. chim., 1921, [iv], 29, 587; A.,36 L. W. Winkler, Chern. Ztg., 1921, 34, 383; A., ii, 539.1920, 4, 139; A., ii, 63.V. Thiiringer, Bul. SOC. Chim. Romcinia, 1920, 2, 73; A., ii, 214.ii, 566.ii, 560160 ANNUAL REPORI'S ON T'EtE PROGRESS OF CHEMISTRY.and on its precipitation as cadmium ammonium ph~sphate.~'Bismuth may also be accurately estimated as ph0sphate.~8Small quantities of arsenic may be estimated colorimetricallyby comparing the stain produced by arsenic hydride on mercuricchloride paper, with those produced by known amounts of arsenic.The advantage claimed for the method over the Gutzeit process isthat the stains are permanent.39Antimony may be separated from tin by precipitation as sulphidefrom a strong hydrochloric acid solution at 80", the tin sulphideremaining in solution at 25".The addition of ammonium chloridelowers the temperature of precipitation, and the best results areobtained with a definite concentration of hydrochloric a~id.~OZinc may be estimated gravimetrically by precipitation asammonium zinc p h ~ s p h a t e , ~ ~ whilst a volumetric method is toprecipitate the metal by means of the double thiocyanate of mercuryand potassium, and to titrate the filtrate with mercuric nitrate, ironalum being used as indicator.42In the absence of certain metals, such as copper and zinc, nickelmay be estimated in the presence of cobalt by titration withpotassium cyanide solution.@Nickel and cobalt may be separated by simultaneous precipi-tation as xanthates, and treatment of the precipitate with dilutenitric acid,44 which dissolves only the nickel compound.Cobalt gives a brown coloration with dimethylglyoxime in thepresence of mineral acids, and a colorimetric method of estimationhas been based on this fact.45A method of separating ferric, aluminium, and chromium hydr-oxides is to boil the precipitate with 10 per cent.sodium hydroxidesolution containing sodium perborate, which dissolves the aluminiumand chromium hydroxide^.^^A new process of estimating iron and manganese depends onL.W. WinkIer, Z . angew. Chem., 1921, 34, 466; A., ii, 656.38 W. R. Schoeller and E. F. Waterhouse, Analyst, 1920, 45, 435; A.,39 J. Cribier, J . Pharm. Chim., 1921, [vii], 24; A., ii, 653.40 G. Luff, Chem. Ztg., 1921, 45, 229, 254, 274, 291; A., ii, 353.41 L. W. Winkler, 2. angew. Chem., 1921, 34, 236; A., ii, 521.ii, 135.I. M. Kolthoff and C. van Dijk, Pharm. Weekblad, 1921, 58, 5 3 8 ; A.,ii, 413.43 G. H. Stanley, J . S. African Ana2. Chem., 1921, 4, 10; A., ii, 351.44 A. Whitby and J. P. Bemdwood, J. Chem. Met. SOC. S. Africa, 1921,45 S. A. Bradley and F. B. Hobart, J . Amer. Ghern. Soc., 1921, 43, 482;46 (Mme) M. and M. Lemarchands, Ann. Chim. anal., 1921, 3, 86 ; A . ,21, 199; A., ii, 562.A., ii, 351.ii, 351ANALYTICAL CHEMISTRY.161their precipitation as hydroxides by means of hexamethylene-tetramine.47A method of estimating gallium, in the absence of zinc, is toppecipitate it as ferrocyanide, to decompose the precipitate withhydrogen peroxide or sodium hydroxide, and to precipitate thegallium as hydroxide.4*Investigation of the methods of separating aluminium fromglucinum has shown that accurate results are obtainable by pm-cipitating the metals as hydroxides, dissolving the precipitate inthe smallest possible amount of sodium hydroxide solution, andboiling the solution to precipitate the glucinum hydroxide.49Under specified conditions, separation by means of sodiumhydrogen carbonate 5O also gives satisfactory results. 51Colorimetric methods of estimating small amounts of chromiumin steel have been published, one of these being based on the redcoloration given by chromic acid with diphenylsemicarbazidesolution.52For the estimation of vanadium in steels and iron alloys precipi-tation with " cupferron " (the ammonium salt of nitrosophenyl-hydroxylamine) gives trustworthy results. 53 The reagent is alsoapplicable to the separation of zinc from uranium.54A hydrolytic process of separating some of the rare earths bymeans of creams of insoluble oxides and carbonates has beendeveloped. 55It has been shown that the composition of potassium platini-chloride as usually separated does not correspond with the formulaK2PtC1,, but that results much closer to the theoretical value maybe obtained by precipitating the salt with alcohol, and drying thesalt a t l10°.56A new method of estimating potassium in silicates by precipi-tation as perchlorate is available in the absence of sodium andcalcium ~ulphates.~' For the estimation of potassium in thepresence of sodium and magnesium sulphates and phosphates4 7 C.Kollo, Bul. SOC. Chim. Rodnia, 1920, 2, 89; A., ii, 218.4 8 L. E. Porter and P. E. Browning, J . Amer. Chem. Soc., 1921, 43,49 H. T. S . Britton, Analyst, 1921, 46, 359; A., ii, 657.5O C. L. Parsons and S. K. Barnes, J. Amer. Chem. SOC., 1906, 28,5 1 H. T. S . Britton, AnaZysl, 1921, 46, 437; A., ii, 712.52 B. S. Evans, ibid., 285; A., ii, 562.A., ii, 277.A , , 1907, ii, 52.111;589 ;53 L. Rolla and M.Nuti, Giorn. Chem. Ind. Appl., 1921, 3, 287; A., ii, 597.54 A. hgeletti, Gazzetta, 1921, 51, i, 285; A., ii, 524.5 5 A. C. Neish and J. W. Burns, Can. Chem. Met., 1921, 5, 69; A,, ii, 560.56 A. Vurtheim, Chem. Weekblad, 1920, 17, 637; A . , ii, 61.8 7 J. J. Morgan, J . Ind. Eng. Chert,., 1921, 13, 225; A., ii, 349.REP.-VOL. XWII. 162 ANNUAL REPOBTS ON THE PROGRESS OF CHEMISTRY.advantage has been Laken of the fact that potassium perchlorateis insoluble in methyl alcohol, whilst sodium and magnesium per-chlorates, phosphates, and sulphetes are soluble. 5t3Another new method depends on the precipitation of potassiumas picrate. 59A colorimetric method of estimating traces of bromine has beenbased on the coloration which it gives with Schiff’s reagent.60A new reagent termed “ fornitral ” (formic acid in combinationwith ed-anilodiphenyldihydrotriazole) gives a quantitative pre-cipitate with nitric acid.61Hypochlorites may be rapidly estimated by a gasornetric method,which consists in beating them wit4 an alkaline solution of hydrazincand measuring the nitrogen evolved.62Strychnine forms an insoluble phosphomolybdate, and advantagehas been taken of the fact for the estimation of small quantities ofphosphoric a ~ i d .6 ~ Another method has been based on the form-ation of a dense yellow liquid, immiscible with water, when phos-phoric acid is shaken with ether in the presence of another acidand an alkali molybdate. This yellow liquid is separated bycentrifuging and its volume read,6aThe difference in the solubility of the respective silver salts in0-5 to 1-5N-sodium hydroxide solution affords a means of separatingarsenates and a r ~ e n i t e s .~ ~Electrochemical Analysis.A simple apparatus, which can be made in the lqboratory, hasbeen devised for the electrometric determination of hydrogen-ionconcentration.66 Another apparatus has for its aim the measure-ment of hydrogen-ion concentration without allowing any volatilematter to escape.67The principles applicable to conductivity titrations have beenelucidated, and it has been shown that in the case of very weakacids and bases accurate results are obtained only within definitelimits for the concentration and dissociakion constants. Methods68 H. Atkinson, Analyst, 1921, 46, 354; A., ii, 654.59 St.Minovici and A. Jonescu, Bul. Soc. Chim. Romrinia, 1921, 3, 23;60 E. Oppenheimer, Arch. E x p . Path. Pharrn., 1921, 89, 17; A . , ii, 273.61 Ann. Chim. anal., 1921, [ii], 3, 207; A., ii, 558.62 A. Macbeth, Chem. News, 1921, 122, 268; A., ii, 461.63 G. Embden, 2. physiol. Chem., 1921, 113, 138; A., ii, 462.64 H. Copaux, Compt. rend., 1921, 173, 656; A . , ii, 707.6s G. W. Sears, J. Arner. Chem. Soc., 1921, 43, 466; A., ii, 3-17.66 G. W. Monier-Williams, Analyst, 1921, 46, 315; A., ii, 650.6 7 A. B. Hastings, J. Biol. Chem., 1921, 46, 463; A., ii, 460.A., ii, 520ANALYTICAL CHEMISTRY. 163fur reducing the dissociation of salts, and for correcting the resultswhere the dissociation limits have been exceeded, have thereforebeen devised.68The catalytic production of formic acid when the solution in ahydrogen electrode contains carbonates is a probable source oferror in electrometric estimations with such ele~trodes.6~The low results obtained in the electrolytic deposition of mercuryhave been investigated, and the conditions for accurate estimationdetertnined.When the cyanide method is used, it is essentialthat the current should not be too strong, and that a large amountof potassium cyanide should not be present.70When a silver cathode is used for the electro-deposition of copper,the deposit may be readily removed by means of an ammoniacalsolution of ammonium trichloroacetate. This dissolves copper,cadmium, and zinc readily, and nickel slightly, but does not dissolvesilver.'lThe condit'ions under which copper can be electrolytically estim-ated in solutions also containing arsenic, antimony, bismuth,selenium, and molybdenum have been investigated.As a rule,deposition of the metals only begins after the bulk of the copperhas separated, but selenium and tellurium are deposited a t thebeginning of the electrolysis. Various reagents must thereforebe employed.72For the separation of mercury and copper in the presence ofchlorine ions, the solution is electrolysed at a voltage of 2.2 and arelatively low amperage, and after deposition of the mercury thevoltage and amperage are incrsa~ted.'~A modified method for the electrolytic separation of copper,antimony, and tin has also been devi~ed.'~For the rapid separation of gold from copper, palladium, andplatinum advantage has been taken of the fact that it is quanti-tatively deposited from a solution of its chloride containing acetate.75Vanadium, tungsten, molybdenum, ferrous salts, chromates, andtartrates interfere with the electrolytic estimation of cobalt andnickel in cobalt steels, and a, method for the removal of thesesubstances has been worked 0ut.~668 I.M. Kolthoff, Chem. Weelzblad, 1920, 17, 694; A . , ii, 124.69 C. L. Evans, J . PhysioZ., 1920, 54, 353; A., ii, 271.7 0 W. BBttger, 2. Elekhochem., 1920, 26, 4 2 5 ; A., ii, 65.7 l H. Waters, J . Amer. Chena. SOC., 1921, 43, '700; A . , ii, 411.7 L F. G. Hawley, Eng. c ~ n d MLn. J . , 1920, 110, 162; A., ii, 216.7J W.Bgttger, Z . angew. Chew&., 1921, 34, 120; A , , ii, 331.7 l 11'. Focrster and D. Aanenseh, 2. Elektrochem., 1921, 27, 10; A., ii, 330.75 W. D. Treadwell, Helv. Chim. Acfa, 11921, 4, 364; *4., ii, 416.7 6 G. E. I?. LundeIl and J. F. Roffmann, J . Ind. Eng. <'hem., 1921, 13,340; A . , ii, 561.a 164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.An accurate method of estimating cobalt is to precipitate it withnitroso-p-naphthol, to ignite the precipitate, and fuse it with alkalisulphate, and to electrolyse the solution after the addition ofammonia and ammonium chloride. 77Iodides may be titrated with permanganate in presence of freesulphuric acid, by means of the potentiometer, provided that theconcentration of the acid is not less than 0.13N.78 The methodmay also be used as a standard in ~xidimetry,~~ and analogousmethods have been devised for the electrometric estimation ofbromates, dichromates, nitrites, and chlorides.80I n the case of iodates, reduction is first effected by adding ancxcess of standard iodide solution in dilute sulphuric acid, and theexcess is electrometrically titrated with potassium permanganate.Conversely, an iodide may be titrated with an iodate, and silvermay be estimated by titration with iodide and potassium perman-ganate solution.81The electrometric method also enables sharp results to be obtainedin the titration of hypochlorous acid with arsenious acid or withpotassium iodide.82Water Analysis.The usual turbidity standard used in the analysis of waters,which is based on an optical measurement, has been shown to beuntrustworthy, and in order to eliminate the error, which in somecases is as great as 50 per cent., the use of a standard powderedsilica with particles of uniform size is sugge~ted.~~Sulphuric acid in water may be rapidly estimated by measuringthe time required for the first indications of turbidity to appearafter the addition of acidified barium chloride solution understandard conditions.I n estimating sulphuric acid gravimetrically,it is essential that calcium should first be removed.84The results of further work on the estimation of active carbondioxide in water 85 have shown that the table of Tillmans andHeublein for the solubility product of calcium carbonate in thepresence of carbon dioxide is inaccurate.7 7 K.Wagenmann, Metall u. Em., 1921, 18, 447; A., ii, 658.7 8 I. M. Kolthoff, Rec. trav. chim., 1921, 40, 532; d., ii, 555.7 9 W. S. Hendrixson, J . Amer. Ghem. SOC., 1921, 43, 14; A., ii, 273.80 Idem, ibid., 1309; A., ii, 651.81 Idem, ibid., 858; A., ii, 411.83 W. D. Treadwell, Helv. Chim. Acta, 1921, 4, 396; A , , ii, 410.B3 Bureau of Standards, Sci. Paper, No. 367, 1920; A., ii, 56.84 L. W. Winkler, 2. angew. Chem., 1920, 33, 311; A., ii, 12ti.ij5 Coinpare Ann. Reports, 1920, 17, 150A N.4 TAY TIC A T, CHEMTSTRV . 165A new table has therefore been calculated for active carbondioxide based on the equation-[CO,] = (a3[HC0,I2. &[Ca"])/(l.13 x lo-"),and is applicable when the concentrations of HCO,', CO,, and[Ca.'] are known.*6The total carbon dioxide content of water may be convenientlycalculated from the results of the colorimetric determination ofthe hydrogen-ion concentration, with neutral-red as indicator, andthe estimation of the hydrogen carbonate content.*'A rapid colorimetric method of estimating phosphates in waterhas been based on the formation of a blue coloration when a dilutesolution of phosphoric acid is treated with a sulphuric acid solutionof ammonium molybdate in the presence of stannous chloride. 88A valuable addition to the criteria of the purity of wai;er consistsin testing for indican, the presence of even a trace of which maybe regarded as an indication of pollution with animal excretions.The test is based on the conversion of the indican into a red orbluish-violet indolignone colouring matter, which can be extractedwith chloroform. Nitrites, however, interfere with the reactionand must be removed before applying the test.89For the estimation of hydrogen sulphide in natural waters,carbonates must first be removed by means of barium chloride,and the filtrate treated with standard iodine solution, followed byan excess of standard thiosulphate solution, and the excess titratedwith iodine solution.g0 A method of estimating volatile hydrogensulphide and carbon dioxide as hydrogen carbonate in mineralsulphide water consists in boiling the water in a current of hydrogen,and absorbing the hydrogen sulphide and carbon dioxide in anammoniacal solution of cadmium chloride and barium chloride.On acidifying this solution with acetic acid, the cadmium sulphideremains, whilst the carbon dioxide is liberated and absorbed in theusual manner.g1Reference may also be made to a new form of soap solution forestimating the hardness of water. This is prepared by neutralisinga solution of palmitic or oleic acid in propyl alcohol with sodiiinihydroxide .92C. AINSWORTH MITCHELL.86 I. M. Kolthoff, Chem. Weekblad, 1920, 17, 390; A., ii, 60.8 7 Idem, 2. Nahr. Genussm., 1921, 41, 112; A., ii, 409.8 8 D. Florenth, Ann. Chim. anal., 1921, 3, 295.89 A. Jolles, Ber. Deut. Pharm. Gee., 1920, 30, 421; A., ii, 69.E. Chrbtien and H. Vandenberghe, Ann. Chim. anal., 1921, [ii], 3, 19;A . , ii, 214.91 J. G. Fairchild, J . Wmhington A d . Sci., 1920, 10, 559; A., ii, 126. '' L. w- W a e r , 2. aragew. Ohem., 1920, 34, 143; A., ii, 413

ISSN:0365-6217    

DOI:10.1039/AR9211800146

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.LAST year the death of Wilhelm Pfeffer was recorded; now weregret that of his most prominent pupil, Friedrich Czapek, whohad succeeded him as Professor of Botany at Leipzig. Czapekwas best known to biochemists through his monumental “ Biochemieder Pflanzen,” of which the second edition was completed in 1921by the publication of the third volume. We have further to recordthe death of Oswald Schmiedeberg, who during the tenure of hischair a t Strassburg (1872-1918) trained many of the pharma-cologists of to-day. Apart from pharmacology, Schmiedeberg ’wasmuch interested in physiological Chemistry ; his most importantcontribution to this subject was probably his work on chondroitjn-sulphuric acid.It is perhaps no matter for regret that no new journals of bio-chemical importance have been started during the current year.The outstanding publication, at least as regards size, is the “ Hand-buch der biologischen Arbeitsmethoden,” edited by E.Abder-halden. At the time of writing, more than fifty parts haveappeared, on subjects ranging from the preparation of laboratoryreagents to the psychology of religion. The work therefore coversa larger field than the “ Biochemische Arbeitsmethoden,” which itis designed to replace. Whilst parts are excellent, in a compilationby 500 contributors the maintenance of a uniform standardcannot be expected, and biochemists who peruse the work willperhaps not always escape a feeling of disappointment, or possiblyof irritation.Until recently, there were but few original text-books of bio-chemistry or chemical physiology in English.This year threenew one8 ham appeared, of unequal scope and merit : “ Principlesof Biochenzistry,” by Brailsford Robertson, “ Biological Chemistry,”by H. E. Roaf, and “Biochemistry,” by B. Moore. The first-named book deals fully with most aspects of descriptive anddynamic biochemistry, and its value to the advanced student isincreased by a select bibliography to each chapter. The secondbook is of a more elementary character. The third is largelyreprinted from original papers by the author; in spite of its title,it only deals with a small portion of the subjeot. Biochemistryseems as yet too young to have evolved a standard type of text-book. A comparison of English and foreign books on the subjectshows it greater disproportion in the treatment of various s u b16PHYSIOLOGICAL CHEMISTRY.167divisions than is met with among text-books of organic chemistry,for instance. But possibly this lack of uniformity is inherent inthe science, or in its relation to physiology. The increased interestin biochemistry in this country is not only shown by the publicationof new text-books; the subject was much in evidence a t theEdinburgh meeting of the British Association.Of other new books published in 1921, the following may bementioned : “ Applied Colloid Chemistry, General Theory,” byW. D. Bancroft; “ The Chemistry of Enzyme Action,” by K. G .Fa&; “ Vitamines. Essential Food Factors,” by B.Harrow(elementary and semi-popular) ; ‘‘ Praktikum der physikalischenChemie, insbesondere der Kolloidchemie, fur Mediziner undBi~logen,’~ by L. Michaelis ; “ Practical Chemical Analysis ofBlood,’’ by V. C. Myers (clinical methods); “ Organic MedicinalChemicals,” by M. Barrowcliff and F. H. Carr (a practical bookconcerned with manufacture), and “ Organic Compounds ofMercury,” by F. C. Whitmore. Nearly all these are American.A second edition of Pfeffer’s “ Osmotische Untersuchungen ” (areprint) has appeared after a lapse of forty-four years. Attentiohmay be directed to three articles of chemical interest which haveappeared in Physiological Reviews ; “ The Carbon Dioxide Carriersof the Blood,” by D. D. van Slyke (1921, 1, 141-176); “ TheSugar of the Blood,” by J. J.R. Macleod (pp., 208-233) ; and“ Physiological Oxidations,” by H. D. Dakin (pp. 394-420).Finally, we may perhaps mention here a new development, whichmay prove of great convenience to research workers; the firm ofHoffmann-Laroche and Co. has published a catalogue (“ Produitsbiochimiques,” Roche) of pure substances of biochemical import-ance, which they are putting on the market; the list comprisesamino-acids, proteins, and substances like acetylcholine, colamine,etc., which have not hitherto been obtainable commercially.Amino-acids and Proteins.A new general method for synthesising amino-acids, or rathera modification of the well-known Erlenmeyer method, has beendescribed by T. Sasaki,l who finds that aldehydes can be con-densed with glycine anhydride (diketopiperazine), which replacesthe hippuric acid used by Erlenmeyer. Its condensation productH,C<g!%:>CH, + 2R*CHO ---+CO-NH reduction R*CH:C<NH.CO>C:CHR --d~$- 2R*C€€2*CH(NH2)*C02HBer., 1921, 54, [R], 163, 2056; A ., i, 196, 808168 ANNUAT, REPORTS ON THE PROGRESS OF CHEMISTRY.with two molecules of aldehyde is readily reduced to the anhydrideof a new amino-acid, which is hydrolysed more easily to the amino-acid itself than when hippuric acid is employed. In this way,phenylalanine, tyrosine, dihydroxyphenylalanine, etc,, have beenprepared, generally in good yield. Mixed anhyades of glycineand another amino-acid condense with only one aldehydeThus dl-leucylglycine anhydride, when heated with benzaldehyde,sodium acetate, and acetic anhydride, yields the substanceC,H9*CH<NAc*Co>C:CHPh, CO--NH which, by reduction and hydrolysis,should furnish leucylphenylalanine anhydride and a correspondingdipeptide.Unfortunately, extensive racemisation occurs ; other-wise this would constitute a valuable method for preparing someof the less accessible dipeptides.The hydrolysis of gelatin by acids has been studied exhaustivelyby H. D. Dakin with his new butyl alcohol method; 4 91.3 percent. of the protein was isolated as pure amino-acids. It is inter-esting to compare Dakin’s results with those of the first use ofthe ester method, by Fischer, Levene, and Aders, in 1902. Theseauthors found 16.5 per cent. of glycine, 0.8 per cent.of alanine,2.1 per cent. of leucine, and 5.2 per cent. of proline; Dakin’sfigures are respectively 25.5, 8.7, 7.1, and 9.5. Yet Dakin foundno new amino-acid in gelatin, indeed one less than Fischer and hisco-workers, for valine seems to be absent. A new tricyclic peptidewas isolated, r-~ydroxy~rolyl~roline anhydride,and unidentified sulphur compounds are also-present .A simple new method for the determination of amino-acids hasbeen indicated by R. Willstatter and E. Waldschmidt-Leitz.5Their carboxyl groups can be titrated in 97 per cent. alcohol withpotassium hydroxide and phenolphthalein as indicator. Similarly,polypeptides can be titrated, even if the alcohol is only 40 per cent.A curious observation on colostrum has been made by P. E.Howe.6 The blood of the new-born calf contains neither euglob-ulin nor pseudo-globulin I, but after it has received colostrum(which is rich in globulin, whereas milk contains scarcely any),the blood contains these two proteins in relatively large amounts.It would appear that the calf receives its fist supply of the globulinsfrom the colostrum; if this is withheld, the globulins are onlyT.Sasaki and T. Hashimoto, Ber., 1921, 54, [ B ] , 168; A., i, 197.3 J . Biol. Chem., 1920, 44, 499; A., i, 66.Ann. Reports, 1919, 16, 153.6 J. Biol. Chern., 1921, 49, 115; A., 1922, i, 80,Ber,, 1921, 54, [ B ] , 2988PHYSIOLOGICAL CHEMISTRY. 169slowly formed. These observations raise some questions relatingto protein assimilation.J. H. aNorthrop 7 has compared the hydrolysis of gelatin bypepsin, trypsin, and alkali with a view to determine whichlinkings are split by each reagent.Those split by the enzymesare also readily split by alkali, but not by acid. Those split bypepsin are also split by trypsin more slowly, but trypsin splits,in addition, other linkings which are not attacked by pepsin.Naturally, the results are somewhat general in character ; they arebased on the results of formol titration after hydrolysis by onereagent, or by several reagents in succession.Pol ysacchurides.Judging from the numerous publications of last year, the poly-saccharides are being more actively investigated than ever before.The interest is shifting from physiological to organic chemistry,and details must be sought in another division of this Report.Here only a few general points can be dealt with.It should beremembered that the first crystalline degradation products ofstarch, of greater complexity than maltose, were obtained by itbiological agent, Schardinger's Bacillus rnucerans. *These crystalline dextrins were investigated by H. Pring~heim,~first with A. Langhans and then with F. Eissler; they are di-,tri-, tetra-, and hexa-amyloses, and the molecular weight of theiracetyl derivatives in a variety of solvents was found t o correspondwith the formula (C6HIOO5),, where n is respectively 2, 3, 4, or 6.These amyloses give green or reddish-brown, crystalline iodineadditive compounds, which dissolve to dark red solutions, andthey are not attacked by diastase, saliva, pancreatin, or emulsin,but are hydrolysed by takadiastase and Penicilliurn africunurn.It now appears, according to the work of P.Karrer and C. Nageli,lOthat diamylose is simply an anhydride of maltose, and that methyl-ated starch (C,H80,(OMe),], has a molecular weight of a t most1200. The aqueous solution of this substance shows the Tyndalleffect, but after ultra-filtration with little loss it is optically emptyand truly crystalloidal. The conclusion is drawn that the starchmolecule contains not more than six dextrose residues united bychemically normal linkings, that is, that it is hexa-amylosepolymerised by subsidiary valencies; and that it is related tothe amylose as a crystal is to a single molecule. H. PringsheimJ .gen. Physiol., 1921, 4, 57; A , , i, 823.Ann. Repow, 1912,9, 98.a Ber., 1912,46, 2533; 1913, 46, 2959; A., 1912, i, 832; 1913,i, 1156.lo Helv. Chim. Acta, 1921, 4, 169, 186, 263; A., i, 310, 311, 313.a170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and W. Persch l1 conclude (from a study of tetra-amylose) thatthe methylation of two hydroxyl groups per hexose residue doesnot cause depolymerisation, which gives additional significance tothe molecular weight determinations of the methylation products.Glycogen is also a polymerised amylose, differing from starch inthe degree of polymerisation. Karrer and Nageli believe themolecular weight of starch to be much smaller than it has beensupposed to be by various authors, for instance, M.Samec andN. Haerdtl,12 who have recorded enormous molecular weights fordifferent varieties of starch, up to 260,000.Inulin is also a relatively simple substance. H. Pringsheimand A. Aronowsky13 find for the molecular weight of triacetyl-inulin in naphthalene, glacial acetic acid, and phenol a mean valueof 2633 corresponding with nine fructose residues, and in agree-ment with this, P. Karrer and L. Lang l4 deduce from the mole-cular weight of trimethylindin that there are eight to ten suchresidues.The case of cellulose is complicated by the formation of bothcellobiose and dextrose on hydrolysis; one of the questions atissue is the amount of the former sugar present in the molecule.Here, as in the case of other polysaccharides, much may beexpected from an application of the methylation methods, whichhave given Irvine and his pupils such valuable results in the caseof the disaccharides.’Nmleic Acids.A second edition of W.Jones’s monograph on this subject hasappeared, and H. Morel15 has also published a useful reviewdealing with it. Both thymus- and yeast-nucleic acid consist offour nucleotides, each composed of phosphoric acid, sugar, and abase, and the main problem remaining is to determine the way inwhich these four nucleotides are united by loss of three moleculesof water. Until recently, Kossel’s suggestion was accepted, thatthe union is through the phosphoric acid groups. On this view,the nucleic acids would be derivatives of a complex pyrophosphoricacid, that is, acid anhydrides. Levene now considers the unionto be between phosphoric acid of one nucleotide and the sugar ofanother, which would make them esters.Jones, whose viewshave to some extent been adopted by Thannhauser, imagines11 Ber., 1921, 54, [ B ] , 3162.12 Koll. Chem. Beihefte, 1920, 12, 281; A . , 1921, i, 226.13 Ber., 1921, 54, [ B ] , 1281; A . , 1921, i, 545.14 Helu. China. Acta, 1921, 4, 249.; A., i, 312.16 Bull. SOC. chim. Biol., 1921, 3, 176PHYSIOLOGICAL CHEMISTRY. 171anhydride formation between the sugar complexes only ; hencehe regards the nucleic acids as ethers. As there seems to be noway of attacking this problem by synthesis, the experimentalwork has been mainly concerned with the products obtained bymild hydrolysis, and the rate at which these products are formed.Heating with dilute ammonia is the method most frequentlyemployed, but picric acid,le calcium hydrogen sulphite,l7 boiledpancreatic extract,l* and snake venom l6 have also been used.In the case of thymus-nucleic acid, the b s t argument againsta linking between the phosphoric acid groups was advanced byP.A. Levene and W. A. Jacobs,1g who by hydrolysis with 2 percent. sulphuric acid were able to split off the two purine derivatives,adenine and guanine; the hexose groups to which these basesare attached are also removed, as levulic acid. The pyrimidinebases are more firmly held and are each obtained attached toone sugar and two phosphoric acid groups, as hexocytidine- andhexothymidine-diphosphoric acids, which give barium salts havingrespectively the formule C,oHl,012N,P,Ba2 and CllH1401,N,P2Ba, ;these acids have therefore each four acidic hydrogen atoms.Eachphosphoric acid grouping must have two free hydroxyl groupsand is united to the sugar by its third hydroxyl. If the twophosphoric acid groups were united together, and one were attachedto the sugar, three hydroxyl groups would be used up in anhydrideformation and only three would be left, so that the diphosphoricacids isolated by Levene and Jacobs would be tribasic instead oftetrabasic. The same acids have been obtained more recentlyby S. J. Thannhauser and B. Ottenstein,16 who consider, how-ever, that they are not preformed in thymus-nucleic acid.Similar arguments have been adduced against the pyrophos-phoric acid formula for yeast-nucleic acid.W. Jones 2O has latelyattempted to disprove it in another way, by comparing the ratesa t which phosphoric acid is set free from yeast-nucleic acid andfrom its four constituent nucleotides. For the entire a<cid, thisrate corresponds with the composite rate calculated for a mixtureof the four nucleotides, so that in the formation of these nucleotideshy hydrolysis no phosphoric acid group is disturbed. Adenineand guanine are moreover split off from their respective nucleo-16 Bull. SOC. chirn. Biol., 1921, 3, 176.1 s S. J. Thannhauser and B. Ottenstein, 2. phyaiol. Chem., 1921, 114, 39;17 H. Steudel and E. Peiser, ibid., 1920, 111, 297; A., i, 136.18 W. Jones, Arner.J . Physiol., 1920, 52, 203; A., 1920, i, 687.lS J. Biol. Chem., 1912, 12, 411; A., 1912, i, 926.*O dmer. J . Physiol., 1920, 52, 193, 203; A., 1920, i, 687.A., i, 521.G" 172 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tides with equal rapidity, so that .the linking cannot be throughthe purine groups, and by a process of elimination Jones drawsthe conclusion that the four nucleotides are held together throughtheir sugar complexes. Jones further hydrolysed yeast-nucleicacid with boiled extract of pig’s pancreas (which does not containany active agents other than that hydrolysing yeast-nucleicacid; hence it leaves the thymus acid unaffected). He observednot the slightest increase in acidity, which ought to have occurredif an ester grouping had been broken down, and hence he concludesthat the union of the nucleotides is between two sugar groups,that is, yeast-nucleic acid is an ether.Levene, on the other hand, adheres to the ester linking betweenthe phosphoric acid of one nucleotide and the sugar grouping ofanother. He 21 considers this to be supported by Jones’s experimentson the rate of hydrolysis, which, in his opinion, merely indicatethat the union of the four nucleotides is more labile than thatbetween the phosphoric acid and (its own) sugar.The increasein acidity due to the breakdown of the ester grouping does notshow itself owing to buffer effect. He formulates thymus-nucleicacid as follows :The arrangement of the basic groups is, of course, to some extentarbitrary, but as thymine and cytosine can be obtained with onesugar and two phosphoric acid groups attached (see above), theycannot both be in the same half of the molecule.Levene hasgiven a similar formula for yeast-nucleic acid.22 By may of com-parison Jones’s formula 23 for this acid may be given.21 J . Biol. Chern., 1921, 48, 119; A . , i , 821.22 Ibid., 1919, 40, 415; A . , 1920, i, 193.23 Aher. J . Physiol., 1920, 62, 203; A., 1920, i, 687PRY STOTAOC, IC AL CHEMTSTRY. 1.73O:P( OH)2*O*C,H,02*C4H,0,N,O:P(OH),*O*b H O*C,H4N,O:P( OH),*O*h H 0*C4H40N3G>:P( OH)2*O*~,H,0,*C,H40N5uracil group badenine group b5b5 cytosine groupguanine groupFinally, we may indicate the present position of the chemicaltechnique of this subject. All the four nucleotides constitutingyeast-nucleic acid have been crystallised in the free state; 24 theirsalts are more readily obtained crystalline. In the case of thymus-nucleic acid, the labile attachment of the purine groups and theinstability of their hexose residues have prevented the sameresult from being obtained.Here the furthest advance is markedby the barium salt of hexothymidine-diphosphoric acid, the mostcomplex degradation product of nucleic acid which has so far beencrystallised. Alleged di- and tri-nucleotides 25 have on furtherinvestigation proved to be mixtures of mono-nucleotides.26Ferments and Fermentation.Various investigators have a t different times suggested thatferment action is preceded by the formation of a complex with thesubstrate, which formation may require the presence of electrolytes.That this is so in the case of amylase has recently been shown byL.Ambard27 in a paper of considerable interest. Powderedstarch removes amylase from solution and keeps it fixed, in spiteof repeated washing in the centrifuge. On the other hand, itgives up the ferment promptly to filtered starch and to glycogensolutions containing neutral salt ; the latter process the authorterms “ d8fixation.” It furnishes a convenient method forestimating amylase (in saliva, blood, urine, etc.); 96-100 percent. of the ferment in a solution may be removed by starch24 P. A. Levene, J . Biol. Chem., 1920, 41, 483; A., 1920, i, 452.25 P. A. Levene and W. A. Jacobs, ibid., 1912, 12, 411; A., 1912, i, 926.W.Jones and H. C. Germann, ibid., 1916, 25, 93; A., 1916, i, 515.S. J. Thannhauser and G. Dorfmuller, 8. physiol. Chem., 1917, 100, 121;A., 1918, i, 47.26 Compare, respectively, P. A. Levene, J . ,Biol. Chem., 1921, 48, 119;A., i, 821. W. Jones and A. F. Abt, Amer. J . Physiol., 1920, 50, 574; A . ,1920, i, 687. P. A. Levene, J . Biol. Chem., 1920, 43, 379; A., 1920, i, 774.27 Bull. Xoc. chim. Biol., 1921, 3, 51; A,, i, 368174 ANNIJAL REPORTS ON THE PROGRESS OF CHEMISTRYpowder, which is then mixed with filtered starch solution con-taining sodium chloride and a phosphate mixture (to maintainthe optimal P, 6.6). After keeping a t 35" for a time, during whicha t most one-tenth of the starch is hydrolysed (and the rate is stillconstant), the action is stopped by alkali, and the maltose isestimated by Bertrand's process.Whether solid starch requiressalt for the fixation of amylase could not be established, for thesolid starch cannot be washed free from salt. Salt-free glycogen" defixes " only 4 per cent., but on addition of salt, 98 per cent.The change of PI, to 5.0 or to 8.0 had no effect on defixation, butcaused in either case a fall of 40 per cent. in the rate of hydrolysis,which is due only to a very slight extent to destruction of theferment.The effect of various salts on diastase action has been ofteninvestigated, recently again by W. Biedermann,2* who calls thesalt a co-ferment and finds that the effect of the anion predominates ;sodium chloride is the most active, followed closely by potassiumthiocyanate.Nitrates, iodides, and sulphates are much lessactive; evidently the effect is a lyotropic one. A. Hahn andR. Michalik29 consider, in the case of pancreatic diastase, thatthe activation by salts is a diminution in the size of the colloidalenzyme particles.Sometthing similar to Ambard's " dbfixation " had been observedbefore in the case of invertase adsorbed on ferric hydroxide, which0. Meyerhof 3O found t o be as active in a sucrose solution as the sameamount of unadsorbed ferment. E. G. Griffin and J. M. Nelson 31showed the same to be true when charcoal is the adsorbent; itis only neoessary to maintain the proper hydrogen-ion concen-tration, which is upset by charooal (this point had been neglectedin earlier experiments, by Eriksaon on invertase, and by Hedinon rennet).Lately, L. Michaelis32 has described a quantitativeconfirmation of Meyerhof's experiments, in an interesting paperdealing with the theory of invertase action. Invertase adsorbedon ferric hydroxide CaMOt be removed by washing with water;it is slowly removed by sucrom, maltose, and raffinose solutions,but not by laefose, dextrose, fructose, mannose, or a- or @-methyl-glucoside. Although invertase adsorbed on ferric hydroxide isevidently colloidal, Michaelia concludes that the kinetics of ahomogeneous system still hold good. The adsorbed invertase,2 8 Fementforsch., 1920-1921, 4, 258; A , , i, 468.29 2. Biol.. 1921, 78, 10; A , , i, 282.aQ Pfiiiger's Archiu, 1914, 167, 251 ; A., 1914, ii, 450.31 J .Amer. Ohem. Sod., 1916, a8, 722, 1109; A., 1916, i, 439, 616.3% Biochem. Z., 1921, 115, 269; A., i, 468PHYSIOLOGICAL CHEMISTRY. 175molecules must all be on the surface of the ferric hydroxide, andare equally active.The adsorption of invertase by various reagents has recentlybeen utilised by R. Willstatter and F. Racke 33 for the purificationof the enzyme. This work is part of an important investigationof enzymes, begun by Willstatter with a view to their preparationin as pure a state as possible.The extraction of invertase from yeast by digestion with wateris by no means a purely physical process; preliminary autolysisis apparently necessary. The manner in which the yeast has beendried and the addition of antiseptics both affect the process.Thecrude extract is purified by adding a limited amount of kaolin,which principally adsorbs impurities. The invertase is thenadsorbed on aluminium hydroxide, from which it cannot beremoved by water, but almost quantitatively by 1 per cent.aqueous disodium hydrogen phosphate, 0.04 per cent. aqueousammonia, very dilute sodium carbonate, or aqueous pyridine.Invertase decomposes spontaneously in ag ueous solution andbecomes quite inactive in a year and a half. Previously Will-statter 34 had investigated peroxydases. A feature of the extrac-tion of the latter from horse-radish is the prolonged intensivedialysis of thin slices of the root, which is subsequently killed bydilute oxalic acid, and thus the enzyme is set free from the cells.After concentration of the extract, the peroxydase is precipitatedby alcohol. In order to control the various operations, a methodof estimation has been worked out, depending on the amount ofpurpurogallin formed (ascertained colorimetrically).After pre-cipitation by alcohol and purification by mercuric chloride, thebest specimens were about 2500 times as active as powdered horse-radish. Later, by adsorption on aluminium hydroxide from50 per cent. alcohol, and recovery by extraction with water con-taining carbonic acid, the activity of the preparation was nearlydoubled. The purest specimens seem to consist chiefly of a nitro-genous glucoside containing more than 30 per cent. of a pentoseand an equimolecular proportion of a hexose, with three atomicproportions of nitrogen.L.Michaelis and M. Rothstein35 have investigated the rate ofdestruction of rennet and pepsin a t various temperatures bydifferent hydroxyl-ion concentrations. Under all conditions, therate for the two enzymes is in constant proportion. The rate of33 Annalen, 1921, 425, 1 ; A., i, 823.34 R. Willstatter and A. Stoll, ibCd., 1918, 416, 21; A., 1918, i, 666.R. Willstatter, ibid., 1921, 433, 47; A., i, 138.3 5 Biochem. Z., 1920, 105, 60; A., 1920, i, 775176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.destruction is proportional to the 1.5th power of the amount ofenzyme present and to the fourth power of the hydroxyl-ion con-centration. The destruction begins when PH exceeds 6.Alcoholic fermentation was last fully dealt with in these Reportstwo years ago, particularly in regard to the second form of fer-mentation which produces glycerol according to the equation :C6HI2O6 = CH3*CH0 + C0, + C3H803.Later, C.Neuberg and J. Hirsch36 distinguished a third form, inwhich the acetaldehyde is " dismuted " into alcohol and acetic:acid, as follows :2C,HI2O, + H20 = CH3C02H + C,H,-OH + 2C3H803 + 2C0,.The proportions of the products demanded by the above equationhave been verified experimentally. In the second form, theacetaldehyde is " trapped " by an alkaline sulphite; the thirdform occurs in the absence of sulphite, when a feebly alkalinereaction is maintained by potassium carbonate, magnesium oxide,or an alkaline phosphate.Neuberg considers that in all varietiesof fermentation pyruvic acid is first formed and is then decarboxyl-ated to acetaldehyde ; these two substances occupy a centralposition in the various schemes. The aldehyde may be trappedby other means than alkaline sulphites. The same object maybe attained by dimethylcyclohexanedione 37 (dimethyldihydro-resorcinol), two molecules of which condense with one of acetalde-hyde to form the substanceQH3CO CH CO/\/ \/\H2C I mk 'CH 1 HC YH2'Me,C ,?[CO O h CMe,\ / \/CH, CH,Lately, M. von Grab 3* has been able to fix pyruvic acid itself bymeans of a biochemical Dobner synthesis of a-methyl-p-naphtha-cinchonic acid.CH3*CO*C02H H2* CH3*C:N 3- 2H,OCH,:C( OH)*CO,H %P,== >CloH6+C0,+H,H :C-CO,H + \36 Bwchem.Z., 1919,100, 304; A., 1920, i, 798.37 C. Neuberg and E. Reinfurth, {bid., 1920, 106, 281; A., i, 914.38 Quoted by Neuberg in a useful r6sum6 in Festschr. d. Kaiser WilhelmBeselEsch. z. FBrderung d. Wiseensch. x u ihrem 10-jahrigen Jubiliium, Berlin,1921, 169PHYSIOLOGICAL CHEMISTRY. 277The central position of acetaldehyde is further revealed by" trapping " it in other fermentations, due to bacteria and moulds.Thus acetaldehyde is an intermediate product in the fermentationof sugar by B. lactis aerogenes 39 and by Aspergillus, Mucor, Monilia,and Oidium.40 Moulds decompose pyruvic acid with the formationof a~etaldehyde.~lW. H. Peterson and E. B. Freda2 have applied the sulphitefixation method to pentose-fermenting organisms (B.acetoethylicusand Lactobacillus pentoaceticus). The largest yield was fromxylose. The first-named organism also produces acetone, whichis perhaps formed from the acetaldehyde by successive conden-sation, oxidation, and decarboxylation .Normally, in bacterial fermentations the acetaldehyde is diB-muted into alcohol and acet'ic acid, and the hydrogen, not findingarn acceptor, escapes as such; that is, no glycerol is formed. Thishappens, for instance, in butyric acid fermentation, and Neubergand Arinsteine have shown recently that pyruvic acid andacetaldehyde are here also intermediate products. An aldol-condensation product of the former substance is considered toundergo decarboxylation and rearrangement to butyric acid, thenett result beingThis Neuberg calls a fourth variety of fermentation.The number of enzymes known to occur in yeast is considerable.Yet an enzyme of a novel type has been discovered in carboligase,Upresent in maceration juice and so called because it links carbonatoms.The phytochemical reduction of benzaldehyde by yeastresults in the formation of benzyl alcohol and, in addition, ahydroxy-ketone of the constitution CH3*CH( OH)*CO*C,H, (orpossibly CH,*CO*CH( OH)*C,H,), which is considered to be formedfrom bemaldehyde and acetaldehyde by a benzoin condensation.Apart from its numerous enzymes, yeast is very complex in themanner in which fermentation is accelerated or inhibited by variousconditions. 0. Meyerhof 45 observed that when sugar is added tomaceration extract there is an induction period, during whichno sign of fermentation is observable, but the induction period39 C.Neuberg, F. F. Nord, and E. Wolff, Biochern. Z., 1920, 112, 144;40 C. Cohen, ibid., 139; A,, i, 150.4 1 T. Nagayama, ibid., 1921, 116, 303; A , , i, 836.43 J . Biol. Chem., 1920, 44, 29; A., 1920, i, 911.43 Quoted from Neuberg's r6sum6, Zoc. cit. (reference 88).44 C. Neuberg and J. Hirsch, Biochern. Z . , 1921, 115, 282; A., i, 480.45 2. PhysioE. Chem., 1918, 102, 186; A., 1919, i, 57.A., i, 148175 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY.is abolished by a trace of hexose phosphate. Disodium hydrogenphosphate affects the interval which elapses before maximal fer-mentation is attained, and other salts, such as sodium chloride,do the same.The induction -period is shortened by the additionof aldehydes and of pyrwic acid (Oppenheimer, Neuberg), whichfunction as hydrogen acceptors. The formation of pyruvic acidfrom dextrose apparently requires the presence of a hydrogenacceptor, which is normally acetaldehyde, derived from the earlierstage of the reaction. The fermentation is therefore autocatalytic.That a hydrogen acceptor is wanting in the induction period wasshown by A. Harden and 3’. R. Henley,46 who could shorten theinduction period by adding methylene-blue. Laevulose can some-what hasten the fermentation of dextrose, but acetaldehyde isfifty times as effective. Harden and Henley have also confirmedthe salt effect observed by Meyerhof.As is well known, hexose phosphate has an enormous effect onthe course of fermentation. A purely chemical effect which isprobably analogous, has been discovered by E.J. Wit~emann,~’who finds that the oxidation of dextrose to carbon dioxide byhydrogen peroxide is catalysed by disodium hydrogen phosphate ;the intermediate formation of a hexose phosphate could not,however, be demonstrated in these experiments. A further purelychemical analogy of another phase of alcoholic fermentation isdescribed by E. Miiller ; 48 finely divided osmium decomposesneutral formaldehyde solution according to the equation :3H2C0 + H20 = CO, + 2CH3*OH.Tissue Oxidation.The reduction of organic substances by nickel at a high tempera-ture, according to Sabatier and Senderens, is a reversible process,and this induced H.Wieland 49 to postulate the same reversibilityfor Paal’s process of reduction at the ordinary temperature bypalladium. He was able to show that in the complete absence ofoxygen, quinol is partly dehydrogenated by palladium black top-benzoquinone ; dihydronaphthalene is partly oxidised, partlyreduced, to a mixture of naphthalene and tetrahydronaphthalene,after the manner of the Cannizzaro (mutase) reaction. TheA . , i, 480, 642.4 6 Biochem. J., 1920, 14, 642; A., 1920, i, 914; ibid., 1921, 15, 175, 312;47 J . Biol. Chem., 1920, 45, 1 ; A., i, 160.48 Ber., 1921, 54, [B], 3214.49 Ibid., 1912, 45, 484; 1913, 46, 3337; 1914, 47, 2085. Compare alsaH. G. Denham, 2. phyaikd.Chem., 1910,72, 641; A., 1910, ii, 598PRY SIOLOaICAL CHEMISTRY. 179palladium finally contains hydrogen and soon becomes inaative,unless the hydrogen be removed by an “acceptor,” which maybe methylene-blue, p-benzoquinone, or simply oxygen. Later,Wieland interpreted as dehydrogenation also reactions, whichare apparently true oxidation (addition of oxygen). He con-siders the conversion of an aldehyde to an acid as the removalof two hydrogen atoms from the hydrated form of the aldehyde :R*C/-OH -+ R*CO + H,\HThus formic acid was shown to be an intermediate stage in theoxidation of carbon monoxide to the dioxide.Starting from this basis, Wieland attempted to explain biologicaloxidations in the same way. Glucose is partly oxidised by pallad-ium black a t the ordinary temperature to carbon dioxide, andthe palladium is found to be charged with hydrogen.If p-benzo-quinone or methylene-blue be added as hydrogen ‘‘ acceptor,”the oxidation proceeds further; 14 per cent. of the glucose wascompletely burnt to carbon dioxide in one experiment, and withoxygen a t 40°, 20 per cent. was completely oxidised. Phenolsand other substances which are generally regarded as substratesfor an oxydase or peroxydase are likewise oxidised by palladium,which is thereby charged with hydrogen, but tyrosine and uricacid are not affected, so that palladium does not imitate the actionof tyrosinase or uricase, which probably are associated with ahydrolytic ferment, absent in the palladium. Ethyl alcohol maybe oxidised to acetic acid by means of palladium and p-benzo-quinone, in the complete absence of free oxygen :The palladium may be replaced by Bacterium aceti, the quinoneby methylene-blue, and still oxidation takes place without element-ary oxygen intervening.The action of the Schardinger ferment,which reduces methylene-blue in the presence of aldehydes, andthe aldehyde mutase of Parnas, which makes aldehydes undergothe Cannizzaro reaction, can all be regarded from the same pointof view. The same ferment (dehydrase) in milk can (1) oxidisesalicylaldehyde to the acid in the presence of free oxygen, whichis then the hydrogen acceptor; (2) in the absence of oxygen actas mutase; half the aldehyde is oxidised, and the other half,acting as acceptor, is reduced to saligenin; (3) in the presence ofmethylene-blue as acceptor, the aldehyde is only reduced.Wieland has since apparently abandoned the above line ofresearch, which is now attracting the attention of physiologists180 ANNUAL REPORTS ON THE PROGRESS OF CJTEMTSTRY.rather t>han of organic chemists.In particular, his ideas havebeen adopted by T. Thunberg in a remarkable paper 50 on inter-mediate metabolism. Thunberg has studied the effect of a largenumber of organic substances on the decoloration of methylene-blue by muscle.Fresh frog’s muscle is cut up very fine and extracted severaltimes with distilled water, in order to remove a substance whichby itself reduces methylene-blue. When the muscle has thusbeen completely inactivated, as little aa 0.2 gram is introducedinto a “ vacuum tube” with 0.02 mg.(about 0.05 millimole) ofmethylene- blue and a considerable excess (400-800 equivalents)of the substance under investigation. After making the mixtureup to 1 c.c., the tube is completely evacuated, filled with water,placed in a thermostat, arid inspected a t intervals for decoloration.If the substance is a ‘‘ donator ’’ of hydrogen, the latter is trans-ferred by an enzyme of the muscle (“ hydrogen transportase ”)to the methylene-blue. According to the author, all nutrient,material must he able to yield up hydrogen, which is the universa.Lprimary fuel of the cell. A substance which does not give uphydrogen cannot be an intermediate metabolite. Hence methylene-blue can be used in order to test substances for their possiblesignificance in intermediate metabolism.There are pronounceddifferences, even between the members of a homologous series ;formic, acetic, butyric, and hexoic acids will give up hydrogen;propionic, isobutyric, and isovaleric acids will not.Succinic acid is most active and by means of mefhylene-blueas little as 0.02 mg. of the acid may be detected and estimated.51Fumaric acid also gives up hydrogen, but much less readily; thelatter reaction is reversible ; some methylene-blue remains un-reduced, however little be taken, for the acetylenedicarboxylicacid formed enters into Competition with the methylene-blue forthe hydrogen :fumaric acid + methylene- blue f--- acetylenedicarboxylic acid + leucobase.Among hydroxy-acids, glycollic and a-hydroxyisobutyric acids areinactive, but lactic and a- and p-hydroxybutyric acids are oxidised.Their dehydrogenation doubtless results in the formation of anunsaturated hydroxy-acid tautomeric with the keto-acid.Asan illustration of the application of the method to metabolicproblems, Thunberg suggests that as a- and p-hydroxybutyricacids are about equally ready hydrogen donators, the former acidmay also be a product of intermediate metabolism.60 Slcand. Arch. Physiol., 1920, 40, 1; A., 1920, i, 784.51 Svenslca Lakaref~renigenshandlingar, 1917, 43, 996; A., 1918, z, 87PHYSIOLOQICAL CHEMISTRY. 181Among the amino-acids examined, glutamic is the most active,alanine has some effect, but various others are inactive.Theremoval of hydrogen is considered to lead to an imino-acid, whichin turn forms the keto-acid, now fully recognised as the first non-nitrogenous degradation product of amino-acids.The question naturally arises whether the dehydrogenation ofso many diverse substances is effected by one and the same enzyme,or by different ones. Experiments on the destruction by cold,and by heat, led Thunberg to the suggestion that the enzymes aredifferent, the one acting on succinic acid being the most stable.Yet the possibility does not seem excluded, that in Thunberg’sdestruction experiments only enough of a single enzyme survivedto dehydrogenate the most sensitive succinic acid, but not toattack other substances, from which hydrogen is removed lessreadily.A most important advance in the investigation of tissue oxida-tion has been made by F.G. hop kin^,^^ who has isolated anautoxidisable cell constituent, which has the catalytic propertiesof a co-enzyme. It is interesting to observe how scientific inves-tigations, a t first widely apart, may ultimately converge on thesame problem. De Rey-Pailhade 53 first showed that extracts ofyeast and of many animal tissues reduce sulphur to hydrogensulphide. They contain therefore, in Thunberg’s parlance, ahydrogen donator, which De Rey-Pailhade regarded as a “ hydrideof protein ” and named philothioiz. Hopkins has now shown thissubstance to be a dipeptide of cysteine and glutamic acid, andcalls i t glutathione.Its isolation was rendered possible byMorner’s delicate nitroprusside reaction for cysteine, which reactionHeffter, and afterwards V. Arn0ld,5~ showed to be given by manytissue extracts. Using this reaction as a guide, Hopkins, by avery complicated process, obtained glutathione, in a yield of 0.01-0.02 per cent. of the fresh tissue employed, from yeast, from muscle,and from mammalian liver. The nitroprusside reaction is alsogiven by proliferating plant tissues, bacteria, and nearly all animaltissues, but not by connective-tissue, nor by blood plasma. Thereaction is not given by the fowl’s egg, but is given by a thirty-hours’ embryo. Glutathione was mostly analysed in the oxidised(disulphide or cystine) form, C1,H,,O1,N,S, ; the thiol form,C,H,,O,N,S, was obtained crystalline. This dipeptide is quiteresistant to proteolytic enzymes, but is hydrolysed by boilingacids to equimolecular proportions of cystine and glutamic acid.Thes2 Biochem. J., 1921, 15, 286; d., i, 635.s3 Compt. rend., 1888, 106, 1683; 107, 43; L4., 1888, 1101.54 2. ph?/siol. Chern., 1911, 70, 300; A., 1911, i, 306182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.outstanding position of the latter among amino-acids in Thunberg'sexperiments has already been referred to above.Hopkins is especially concerned with showing that glutathioneexercises real functions in the chemical dynamics of the cell. Asin the case of other thiol compounds, the oxidation to the disulph-ide form depends greatly on the hydrogen-ion concentration.Inneutral or slightly alkaline solution, it is oxidised spontaneouslyby air, but in acid solution it is a less ready donator of hydrogenand is more stable. The oxidised form, on the other hand, is ahydrogen acceptor; fresh tissues placed in a solution of theoxidised form reduce it, as shown by the development of thenitroprusside reaction. Fresh tissues also reduce methylene-blue(as was pointed out above in discussing Thunberg's work), butwhen they have been kept sufficiently long for their reductionpotential to have fallen, so that methylene-blue is no longer reduced,they now oxidise the reduced dipeptide under anaerobic conditions,so that some other substance must act as hydrogen acceptor.The converse reaction, reduction of the disulphide form, dependsgreatly on the hydrogen-ion concentration.In slightly acidsolutions (P, < or = 6%), the disulphide form simply competeswith methylene-blue for the reducing action of fresh tissues, andas a result, the normal rate of decoloration of the methylene-blueis slowed. In slightly alkaline solution (PIX > or = 7*4), the rateof decoloration is greatly accelerated by the addition of oxidisedpeptide, which now functions catalytically like a co-enzyme.Herein it differs from succinic acid and the other substancesinvestigated by Thunberg, which are dehydrogenated irreversibly.The reversibility of the action of glutathione is closely connectedwith its thiol grouping. The autoxidation of this group in cysteineand other compounds has been studied by A.P. Mathews andS. Walker 55 and by T. Thunberg ; s6 it is much influenced bycatalysts.During the year two reviews on physiological oxidation haveappeared; the one, by Dakin, is referred to in the introduction;the other is by P. Woringer and occupies the September numberof the Bulletin de kc Xoci4tte' de chirnie biologique (1921, 3, 3 1 1 4 5 0 ) .The Chemistry of Muscular Contraction.We are still very ignorant of the way in which the muscletransforms chemical into mechanical energy. The source of theformer is some carbohydrate, glycogen, or its fission productJ . Biol. Chem., 1909, 6, 289; A., 1909, i, 698.b6 Skand. Arch. Physiol., 1913, 30, 285; A., 1914, i, 386PHYSIOLOGICAL CHEMISTRY. 183dextrose, and the presence in muscle of lactic acid (isomeric witha triose) suggested that it had something to do with the energytransformation.Nevertheless, lactic acid accumulates in theliving muscle only after violent exertion, and then only to a slightextent, so that there must be a mechanism for its rapid removal.Some interesting light on the origin of lactic acid from carbo-hydrates has been obtained by G. Embden and his pupils, whofound 57 that muscle press juice contains a substance capable ofgenerating lactic acid, which they called lactacidogen. Later, 58they described the preparation, in a yield of 0.05 per cent. of themuscle employed, of an osazone identical with that previouslyobtained by A. von Lebedeff S9 and W. J. Young 6o from yeastand recognised as derived from hexose phosphoric acid.Whether lactacidogen itself is quite identical with the co-enzymeof alcoholic fermentation is not decided, but a t any rate the twosubstances are closely related, and there are some points ofsimilarity between the methods of degradation of the glucosemolecule in muscle and in yeast.This similarity has also beeninsisted on by 0. Meyerhof,61 who found that extracts of musclecontain the co-enzyme of alcoholic fermentation and that thissubstance plays a part in the respiration and energy transformationin the muscle. Embden and his co-workers have more recentlyexamined the effect of a large number of physiological factors onthe lactacidogen content of muscle; a whole number of theZeitschrift fur physiologische Chemie 62 was exclusively devotedto these researches.Some of the main conclusions are as follows.Where muscular activity is greatest, there is most lactacidogen.Frogs contain more a t 30" than a t O", and the increase in lact-acidogen is accompanied by a decrease of residual phosphorus.The synthesis of lactacidogen is not under nervous control. Thewhite muscles of rabbits contain about twice as much as themoresluggish red ones, which latter, on the other hand, are richer innon-lactacidogen phosphorus, which is regarded as in reserve.Muscular work and strychnine convulsions decrease the lact-acidogen in the white muscles of the rabbit, but not in the red,where, owing to slower action, time is given for its re-synthesis.Since both carbohydrate and phosphoric acid are necessary forthe production of lactacidogen, the idea suggested itself of adminis-5 7 Biochem.Z . , 1912, 6, 45, 63; A . , 1912, ii, 1071, 1072.58 2. physiol. Chem., 1914, 93, 1 ; 1917, 100, 181; 1921, 113, 1 ; A.,59 Biochem. Z . , 1909, 28, 114; A., 1909, i, 863.fil 2. physiol. Chem., 1918, 101, 165; 102, 1 ; A., 1918, i, 242, 464.62 1021, 113, 1-312; A., i, 528-530.1915, i, 344; 1917, i, 674; 1921, i, 528.Ibid., 1911, 32, 177; A., 1911, i, 422184 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tering phosphate in order to increase the capacity for work.Numerous experiments on soldiers (with an ergostat and by march-ing) and on miners are recorded 63 in which 7.5 grams of sodiumdihydrogen phosphate per day by the mouth is said to haveincreased the capacity for muscular work.0.Meyerhof 154 has stated the view that the transformation ofhexose to lactic acid is reversible, according to the following scheme :hexosediphosphoric acid + 2H,O = 2 lactic acid + 2 phosphoric acid3 lactic acid + 2 phosphoric acid + 30, = 3C0, + 5H,O +1 hexosediphosphoric acid.W. Hartree and A. V. Hil165 have studied the same problemby a purely physical method, measurement of the rate of heatproduction in a stimulated frog’s muscle at different temperatures.The temperature coefficient is 2.8 for 10” and previously the rateof relaxation was shown to have a coefficient of 2.2, so that bothprocesses are’ purely chemical (the energy liberated by the changefrom dextrose to lactic acid is only about 16 per cent.of the heatgiven out, but the 84 per cent. is derived from potential energydue to the effect of lactic acid on some “ active’’ structure orsurface). The observations suggest to the authors the mechanicalanalogy of a large reservoir of compressed air, connected by anarrow tube with an elastic bag with a, release valve. When thevalve is opened, the air rushes out, a t first rapidly and then moreslowly until the rate of outflow reaches a value determined bythe bore of the connecting tube. Chemically, the large reservoirof energy is the store of glycogen in the muscle, the narrow tubeis a catalyst, transforming the glycogen into lactic acid. (Theadministration of phosphate in Embden’s experiments, describedabove, would be an attempt to widen the tube.) The elastic bagis represented by the balanced action, carbohydrate lacticacid.The opening of the bag is represented by a temporarypermeability to lactic acid, produced by the stimulus in somemembrane. The lactic acid escapes and causes a change in colloidalproperties, resulting in contraction of the muscle-fibres. In thelater stages of prolonged stimulation the lactic acid is removed atthe same rate a t which it is supplied, and a dynamic equilibriumis established, corresponding with the steady production of heat(which has the temperature coefficient of 2.8 per 10”).63 G. Embden, E. Grafe, and E. Schmitz, 2. physiol. Chem., 1921, 113, 67;64 PfEiiger’8 Archiv, 1920, 182, 232, 284; A., i, 76.e6 J .Phpiol., 1921, 55, 133; A., i, 527.A., i, 529PHYSIOLOQICAL CHEMISTRY. 186Accessory Food Substances and Calcium Metabolism.A method of estimating the vitamin-B content of a solutionby its effect on the growth of yeast, as suggested by Williams andothers,66 has been further criticised by various authors, who findthat yeast can synthesise this vitamin. V. E. Nelson, E. I. Fulmer,and R. Cessna67 subcultured a yeast on alternate days throughouta year by adding 1 C.C. of the culture to 50 C.C. of a solution con-taining only salts and sucrose. The maximum concentration ofthe original constituents was thus 1 x 50-lSO. Yet a t the end ofthe year the yeast contained enough vitamin-B for the normalgrowth of rats. Similar conclusions were drawn by M.R. Mac-Donald and E. V. McCollum 6s and by A. Harden and S. S. Zilva; 69the latter authors showed the presence of vitamin-B by its curativeeffect on polyneuritis in pigeons.Since we are as yet completely ignorant of the chemical natureof vitamins, the observation by S. S. Zilva and M. Miura70 is ofsome interest, that both the antineuritic and the antiscorbuticvitamins diffuse through a collodion membrane of such permeabilityas permits the passage of methylene-blue, neutral-red, safranine,and other serni-colloids. The fact that vitamin-A is destroyed byatmospheric oxygen, 71 particularly at high temperatures, has beenfurther ~onfirmed,'~ and exposure to ozone has been found to havethe same effect.73During the year the main interest in vitamins has, however,shifted to the anti-rachitic substance and its connexion withcalcium metabolism, which is leading to some new points of view.E.Mellanby 74 has published in detail his extensive researches 011the production of experimental rickets in dogs. He has dietednearly four hundred puppies and draws the conclusion that amongthe conditions which induce rickets the most important are adeficiency, in the diet, of calcium and phosphorus and of fat con-taining the anti-raehitic vitamin. Since the effect of fats in pro-moting growth runs parallel to their effect in preventing rickets,it is highly probable that the anti-rachitic vitamin is identical withvitamin-A. Thus butter fat, through which oxygen is bubbledG 6 Ann.Reports, 1920, 17, 167.G i J . BioZ. Chem., 1921, 46, 7 7 ; A . , i, 386.6 8 Ibid., 1920,45,307; A., i, 480. 69 Biochem. J., 1921,15,438; A . , i , 702.70 Ibid., 422; A., i, 702. 71 Ann. Reports, 1920, 17, 165.72 F. Q. Hopkins, Biochem. J., 1920, 14, 725. J. C. Drummond and73 S. S. Zilva, ibid., 740; A . , i, 475.74 " Special Report Series of the Medical Research Council," No. 61 ;H.M. Stationery Office, 1921.K. H. Coward, ibid., 734; A., i, 475186 ANNUAL REPORTS ON THE PROGRESS OF CIIEMISTRY.for some hours at 120°, lo& both its growth-promoting and itsanti-rachitic power. Cod-liver oil is particularly active in bothdirections. Recently a number of papers have appeared on ricketsin rats, which have been found suitable for this as well as for manyother experiments on vitamins.A. F. Hess, G. F. McCann, andA. M. Pappenheimer75 disagreed with Mellanby’s view that adeficiency of fat-soluble vitamin is a cause of rickets, but McCollumand his co-workers have confirmed the effect of cod-liver oil instimulating calcification processes after the production of ricketsby defective diets. E. V. McCollum, N. Simmonds, P. G. Shipley,and E. A. Park 76 give a more complicated explanation of thecausation of rickets. According to them, rickets (in rats) is notsimply due to a deficiency of vitamin-A, as suggested (for dogs)by Mellanby. To produce rickets, the calcium : phosphorus ratioof the diet must be upset as well, making its calcium contentrelatively high, its phosphorus content low.With a calcium : phos-phorus ratio differing from the optimal for normal ossification,rickets may still be avoided by giving an anti-rachitic substance.The ratio of calcium : phosphorus is considered by these authorsto be of “infinitely greater importance” in ensuring normalossification than the absolute amounts of these elements in thediet. The importance of calcium, as well as of vitamin-A, mayperhaps to some extent reconcile the contradictory results ofMellanby and of Hess and his associates. Rather similar viewswere stated quite recently by V. Morenchevsky, 77 who concludesthat a deficiency of calcium alone may affect the skeleton of ratsin a manner suggestive of rickets, and that a deficiency of vitamin-Aalone may also produce slight rickets; the changes typical ofricket’s are, however, most readily produced when the diet isdeficient in both calcium and vitamin.Thus a curious and novel relationship between vitamin-A andcalcium metabolism is indicated. The latter is evidently of acomplicated nature.P. Rona and D. Takahashi’s showed tenyears ago, by the method of compensatory dialysis, that 3040per cent. of the calcium in serum is non-diffusible, and last yearA. R. Cushny 79 found that when serum is filtered through collodionall the crystalloids pass through, with the exception of somecalcium and probably some magnesium. During rickets, thereis a slight diminution in the calcium content of serum, duringtetany after removal of the parathyroids there is a larger fall, butin either case this is at the expense of the diffusible portion; the7 5 J.Biol. Chern., 1921, 47, 395; A., i, 757.7 6 Ibid., 507; A., i, 757.7 8 Biochena. Z., 1911, 31, 336; A., 1911, ii, 302.70 Ann. Reports, 1920, 17, 161.7 7 Brit. Med. J., 1921, ii, 547PHYSIOLOGICAL CREMISTRY. 187non-diffusible calcium remains constant, according to L. vonMeysenbug and G . F. hfcCann.80 The calcium (and phosphorus)nietabolism may also be disturbed, according to S. V. Telfer,slby the comp1et.e exclusion of bile from the gut, which brings inits train non-absorption of fatty acids and their excretion ascalcium soaps in the faces. The phosphoric acid, normallyexcreted as calcium salt by the intest,ine, is now eliminated in$he urine.Apart from metabolic questions, the mechanism of the depositions f calcium in the bones probably has a bearing on rickets.E.Freudenberg and B. Gyorgy 82 have attempted to supply a (physico-chemical ‘2 ) basis for calcification. They conclude that cartilagetakes up calcium from a 0-O1N-solution until an equilibrium isreached. Tryptic digestion and autolysis, as well as urea andammonium chloride, inhibit calcium fixation. The authors suggestthat normally the organism satisfies the conditions necessary forcalcification, except where the process is inhibited by metabolihes.Chemotherapy.Towards the end of 1920 an advance in chemotherapy becameknown, which promises to provide a cure for sleeping sickness andto rival the discovery of salvarsan, a t least in scientific interest.T,. Haendel and K.W. Joetten83 report on a new trypanocjde ofgreat activity, which is referred to as “205 Bayer.” In a foot-note the editor of the journal states that he has exceptionallydeparted from the principle that no account could be taken ofsecret remedies, for the composition of the substance is not pub-lished, “ in consequence of the judicially uncertain and unprotectedposition of German industry with respect to the former enemycountries.” (An allusion to their treatment of German patents.)The authors, working in the Reichs-gesundheitsamt at Berlin,investigated a substance prepared by the Farbenfabriken vorm.Priedr. Bayer & Co., which frees mice, apparently permanently,from Nagana and other pathogenic trypanosomes in doses ofIj20 mg., and is lethal to the host only in doses of about 2 mg.,or 40 times as much.The substance is rather specific, for spiro-chztes and the non-pathogenic Trypanosoma Lewisii are not muchaffected. M. Mayer and H. Zeiss 84 have published a more extensiveinvestigation of the same substance, and place the subcutaneous80 J . Biol. Chem., 1921, 47, 541; A., i, 754.81 Biochem. J., 1921, 15, 347; A., i, 700.82 Biochem. Z., 1921, 121, 142.B4 Arch. Schiffs u. Tropmhyghe, 1920, 24, 267; A., i, 908.BerE. Klin. Wochenschr., 1920, 57, ii, 821 ; A., i, 908curative dose for mice a t 0.06 mg. for T. brucei (Nagana), T.equinum, T. equiperdum (dourine), T. gambiense (human sleepingsickness), and T. rhodesiense, and the lethal dose a t 10 mg., givingthe extremely favourable ratio of 1 : 160.The substance doesnot kill the trypanosomes very rapidly, like potassium antimonyltartrate, but ta,kes about fort'y-eight hours to sterilise the host,apparently by stopping the reproduction of the parasite, of whichundivided twin specimens are found in large numbers in the blood,Rats, guinea-pigs, and rabbits can also be cured permanently,and very favourable results have been obtained in natural dourineof horses. C. M. WenyonS5 has quite recently confirmed theseresults for mice and T. equiperdum by intravenous injection. Inview of the high ratio of lethal dose : curative dose, he observesthat for sodium antimonyl tartrate in mice it is only 4. (For manit is < 1, so that no cure with antimony can be effected.)Although the exact composition of " 205 Bayer " remains asecret, the curiosity of chemists may perhaps to some extent besatisfied by a perusal of the patents of the years 1914-1916.Farbenfabriken vorm.Friedr. Bayer & ( 3 0 . ~ ~ describe the prepara-tion of carbamides of the naphthalene series which are stated tobe strongly trypmnocidal. By the action of p-nitrobenzoylchloride on 8-amino-a-naphthol-3 : 5- and -3 : 6-disulphonic acids( K and H acids), a compound results which, after reduction ofits nitro-group, is condensed with carbonyl chloride to a complexcarbamide, for instance,Instead of condensing with carbonyl chloride, the first condensa-tion product may be united with a second molecule of p-nitro-benzoyl chloride and reduced, furnishing, for instance, for the3 : 6-disulphonic acid the substanceH0,S ()\)S 0,Hg 5 Brit.Med. J., 1921, ii, 746; A., i, 908.13% D.R.-P. 278122; Chem. Zentr., 1914, ii, 964; Brit. Pat. 9472 of 1914;A., 1915, i, 14. See also D.R.-P.P. 289163, 289270-289272; A., 1916,i, 390; Brit. Pat. 8591 of 1916; A., 1918, i, 113; and further D.R.-P.P.284938, 288272, 288273, 289107, and 291351PHYSIOLOGICAL CHEMISTRY, 189and this may, in its turn, be converted into a carbamide sulphonicacid, which is used as the neutral sodium salt. Later patentsindicate numerous substances with cliff erent substituents in thenaphthalene and benzene rings, and the last one mentions am - amino benzo yl derivative of m - amino b enzo ylaminosulp ho s alic y licacid, without any naphthalene ring.It will be seen that all theseOH CO,EI~)NK(:O/\NHCO~\)NH, I I\/ \/ \/SO&compounds, like polypeptides, contain scveral times the groupingNHCO. They are dyes and resemble Trypanrot in being deriv-atives of naphthylaminesulphonic acids." Bayer 205 " is very active on trypanosomes, but much lessso on spirochzetes; the reverse is the case with sodium bismuthtartrate, a new therapeutic agent recently introduced in Franceby R. Sazerac and C. Le~aditi.~' This analogue of tartar emeticis injected, suspended in oil, and has given very promising resultsin the treatment of human syphilis, but is not very effectiveagainst the Nagana trypanosome. Sodium antimony1 tartratehas of late years been found to be a specific against Kala-azar,due to a protozoon, and against the worm Filaria sanguinis horninis,but the administration of antimony in sleeping sickness has notbeen quite successful. There is a t present some falling off inattempts to synthesise arsenic compounds which might rivalsalvarsan or its immediate derivatives, but our knowledge con-cerning the latter substance and its technical impurities is increasing.The biological testing of salvarsan has revealed the considerablevariation in the toxicity of commercial samples and one of thereasons for this variation seems to be the use of sodium hyposulphiteas a reducing agent.R. G. Fargher and F. L. Pymanss foundthat the slight sulphur content of technical preparations is dueto admixture with a substance containing sulphur which entersthe molecule in the reduction of 3-nitro-4-hydroxyphenylarsinicacid by sodium hyposulphite ; with hypophosphorous acid thisintroduction may be avoided.W. G. Christiansen 89 has con-firmed these results and states that the prdduct prepared byhypophosphorous acid is relatively non-toxic. H. King 90 hasnow identified sulphur compounds which were regularly formedunder the conditions employed by him in the reduction, to the87 Compt. rend., 1921, 172, 1391; 173, 338; L. Fournier and L. Guenot,ibid., 1921, 173, 674; A., i, 908. T., 1920, 117, 373.T., 1921, 119, 1107. J . Amer. Chem. Soc., 1920, 42, 2402190 ANNUAL BEPORTS ON THE PBOURESS OF CHEMISTRY.extent of about 10 per cent.; this amount is large enough t oaccount for all the sulphur oi most specimens.These compoundsare 3-amino-4- hydroxy-5-sulphinophenylarsinic acid, and f t cr asmaller extent) the corresponding arseno-derivative,The latter is found to be twice as toxic to mice as sduarsan prc-pared by hypophosphorous acid.Artijkial Sweetenitz y 11 ye1~1.s.Apart from saccharin, the only artificial sweetening agent whic*i thas met with practical application is dulcin, EtO*C,H4*NH*CO*NH,.In the case of both substances, even the slightest modificationsin the molecule generally abolish the sweet taste entirely. Thornsand Nettesheim 91 find that the methoxy-compound correspondingwith dulcin is somewhat sweet, and the hydroxy-compound onlyvery slightly so; all other derivatives had no sweet taste at all.Pure saccharin, the more powerful of the two, is generally statedto be 550 times as sweet as sucrose, but Th. Paul 92 has shown thatthe comparison of sweetening powers is no simple matter. Sac-charin and dulcin mutually reinforce one another ; this pharmaco-logical effect has been alleged to occur with a number of drugsand is well established in the case of opium alkaloids, for instancc,As an example, Paul mentions that when 280 mg. of saccharinand 120 rag. of dulcin are dissolved in 1 litre of water, they causethe same sweetness as 535 mg. of saccharin by itself. A furthercomplication 93 is that at various concentrations of the solutionthe ratio of the sweetening power of saccharin to sucrose is notconstant and may vary from 200 in concentrated solution to '700in dilute solution. Similarly, the ratio for dulcin varies from 70to 350. In other words, both these substances are relativelysweeter in dilute solution. This phenomenon is not shown bythe various sugars, which have a constant ratio of sweetness,independent of the concentration. The physiologioal effect ofthese synthetic substanoes is apparently of a different naturefrom that of the sugars.-4 third artificial sweetening agenfi has lately become the subject,of a patent 94 in which it is claimed that it is two thousand times as91 Ber. deutsch. Pham. Ges., 1920, 227, 295.92 Chem. Ztg., 1921, 45, 38; A., i, 109.93 Ibid., 705. 94 S . Furukawa, Jap. Pat. 35332; A , , 1920, i, 676PHYSIQLOGICAL CHEMISTRY. I91sweet as sucrose, so that it would be the sweetest substance known.This is the a-anti-aldoxime of perillaldehyde; it has been furtherdescribed by S. Purukawa and Z. Torni~awa.~~ Perillaldehyde,C,H,,*CHO, is a Isvorotatory liquid, b. p. 104”/9 mm., of unknownconstitukion, which forms 44-57 per cent. of the essential oil ofthe leaves of Perilla nankinensjs Ikne., a Labiate known in Japanas “ Shiso.” The leaves are used as a vegetable or condiment.The oil of P. ocymoides, L., is a technical product in Eastern Asia(Wehmer, “ Die Pffanzenstoffe,” p. 822). According to Furukawaand Tornizawa, the anti-aldoxime of perillaldehyde, two thousandtimes as sweet as sucrose and four to eight times as sweet assaccharin, differs in this respect entirely from the p-syn-aldoximo,which is not sweet a t all. These two substances therefore providea novel and interesting example of the different physiologicalbehaviour of stereoisomcrides which has so far been principallystudied in enantiomorphs (adrenaline, hyoscyamine, hyoscine) .Perillonitrile, C,H1,*CN, is half its sweet as saccharin. It is Rcurious fact that the anti-oxime of perillaldehyde was describedas long ago as 1010,96 but that its sweet taste, now the reason fora patent, was not then noticed. Possibly organic chemists shouldmore frequently taste their new compounds than they do a tpresent.GEORGE BARGER.Q5 J . Chesn. Ind. Tokyo, 1920, 23, 342; A . , 1920, i, 751.96 Schimmel & Co., Bericht, October, 1910; A., 1910, i, 759

ISSN:0365-6217    

DOI:10.1039/AR9211800166

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.THE investigations in the past year have in the main followed thelines of previous years : there are, however, signs of more move-ment. In France, the Annales de la Science Agronomique has beenrestarted, under the able editorship of M. Albert Bruno, and alreadythere is an increase in the output of scientific work. In Englandand in America, investigations begun after the Armistice are reach-ing the. stage of publication, and certain directions of specialisationcan now be observed. These will be indicated under the variousheadings.Soil Investigations.British soil investigators are studying the biological factors ;American workers are ascertaining the properties and relationshipsof the soil solution and of the soil acidity; whilst Continentalworkers are studying the physico-chemical relationships of the soil.This course is economical of time and effort, but it would be attendedby grave disadvantages if the specialisation proceeded so far as toobscure the fact that all three aspects of the subject are of vitalimportance to the study of soil fertility.The Soil Solution.The soil retains by absorption and surface attractions some10 to 20 per cent. of its weight of water, distributed as films overits particles.The water dissolves some of the soil constituents,forming a solution which is of obvious importance as the mediumthrough which plants and micro-organisms derive their food ; indeedi t may be regarded as the culture solution for the plant.Experi-mental work, however, is hampered by the difficulty of separatingit from the soil ; when soil contains moisture in percentages suitablefor plant growth, the solution is held by the soil particles with suchforce that no ordinary means will remove it.Various methods have been suggested for isolating the solutionfrom the soil. Reasons are advanced for supposing1 that theF. W. Parker, Soil Sci., 1921, 12, 209 ; A,, i, 914.19solution obtained by Ischerekov's displacement method gives amore faithful representation of the soil solution than the othermethods which have been used; ethyl alcohol was the best of thedisplacing fluids tested, and was without observed influence on thecomposition of the soil solution ; successive portions of the displacedsolution gave the same freezing-point depression and contained thesame amount of total solids, whilst the concentration was inverselyproportional to the moisture of the soil.It is, however, difficult to extract the solution, and methods havebeen devised for studying it in situ.It is suggested 3 that a studyof the vapour pressure of the soil would give much valuable informa-tion, whilst the depression of the freezing point has been muchstudied by Bouyoucos in America.show that the latter method leads to substantially the same con-clusions as the 1 : 5-water extraction method used in the UnitedStates.5The water extract has not quite the same composition as the s6ilsolution, but is not greatly dissimilar. When concentrated to havcthe sa'me freezing point, it presumably resembles the actual solutionalso in concentration and should then undergo no change whenplaced in contact with soil.Experiment showed that this was thecase, and probably for the first time in history a solution was pouredthrough the soil and came out unchanged in composition.The relationship between the concentration of the soil solutionand plant growth has previously been studied in the case of barley; 6similar resultls have now been obtained with maize, horse beans,potatoes, and t ~ r n i p s . ~ The concentration a t any point in the soilis not significantly reduced until the plant root actually reaches it,that is, there is no drift of solutes in the soil apart from the move-ment due to drainage.Apparently, however, the fact that a substance occurs in the soilextract affords no certain proof that i t can be absorbed by plants.Orthoclase yields up potassium to water, but the dissolved potassiumwas not absorbable by wheat.It became available, however, whenthe solutions were treated with a mixture of hydrochloric and nitricacids.8 Apparently the solute complex is not dissociated, and theplant is unable to take up the undissociated material.Moagland and his colleaguesZhur. Opuitn. Ap-on., 1907, 8, 147.M. D. Thomas, Soil Sci., 1921, 11, 409.4 D. R. Hosgland, J. C. Martin, and G. R. Stewart, J . Agric. Res., 1920.20, 381; A., i, 214.G. R. Stewart, ibid., 1918, 12, 311.Ann. Reports, 1918, 15, 173; 1919, 16, 172.G. R. Stewart and J.C. Martin, J . Agric. Res., 1931, 20, 663.J. F. Breozeale and L. J. Briggs, ibid., 615; A., i, 388.REP.-VOL. XVIII. 194 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The variation in composition of soil solution brought about byplant growth affects the degree of dispersion of the colloidal materialof the soil; a large increase in dispersion was observed when thesoil solution was depleted as the result of absorption of solutes bythe plant.9The same change has been studied in a different manner inGermany, where Wiegner's method has been successfully used byvon Seelhorst to study the changes in physical condition of soilbrought about by cropping and manuring.10There is a constant interchange between the colloids of the soiland the soil solution, and the ions affect the state of coagulation ofthe colloids.llSoil Constituents.The soil constituents fall into two great groups-organic substanceswhich have been synthesised in the growing plant and then returnedto the soil either directly or through the bodies of animals or micro-organisms, and inorganic substances derived from the minerals inthe soil, which very often have also passed into plants and.beenliberated on the decay of the leaves, stems, or roots. Among theorganic constituents, one of the most interesting is humus, a black,sticky substance to which important properties have been attributed,although it must be admitted that the direct evidence is not verystrong. Two views have been put forward as to its origin.Beckley l2 supposes that the carbohydrates decompose to formhydroxymethylfurfuraldehyde, which then condenses to formhumus; some experimental evidence is given for this view, whichhas also been put forward inde~endent1y.l~ Eller and K o c ~ , ~ ~ onthe other hand, suppose that humus is formed by oxidation ofquinones which arise by the elimination of water from hexoses.They assign to it the formula C,H,O, :0O- 0Q D. R.Hoagland and J. C. Martin, J . Agric. Res., 1920, 20, 397; A . ,10 C. von Seelhorst, W. Geilmann, and H. Hubenthal, J. Landw., 1921,11 L. Casale, Staz. aperim. apar. ital., 1921, 54, 65.12 V. A. Beckley, J . Agric. Sci., 1921, 11, 69; A., i, 227.l3 J. Marcusson, Ber., 1921, 54, [B], 542; A., i, 313.Ibid., 1920, 53, [BJ, 1469; A., 1920, i, 733.See also W. Eller, Brennetog-Chem., 1921,2, 129; A,, i, 506; H. Stoltzenberg and M. Stoltxenberg-Bergius,2. physiol. C'hem.: 1920, 111, 1 ; d., i, 32.i, 215.69, 5 ; W. Gefimann and A. von Hauten, ibid., 105AGRICULTURAL CHEMISTRY AND VEGETABLE PEESIOLOGY. 195Against this view it is urged 15 that natural humus, unlike benzenederivatives, cannot be sulphonated or nitrated, whilst other ex-periments indicate that the acidity is due to carboxyl and not tophenolic groups.16Several interesting papers have appeared on clay, using the wordin the sense of the soil investigator, and not of the ceramic chemist.This is the fraction of soil the particles of which are 0.002 mm.or less in diameter. This has been subdivided into twenty-sixfractions by elutriation methods and each fraction fully analysed.About 80 per cent.of the total day had a fairly constant com-.position, closely approximating t'o the theoretical clay complex,A120,,2Si02,2H20. The remaining fractions, consisting of thecoarser grades, showed a gradually increasing silica content. l7A suggestive investigation which recalls some earlier work bySchloesing p&re has been published from the United States Bureauof Soils.1s Aqueous extracts of soil frequently contain a considerableamount of colloidal material, which renders them opalescent evenafter standing, and no ordinary filtration suffices to clear them.Quantities of this material have been extracted from soil andexamined; it consists mainly of hydrated silicate of aluminiumwith varying amounts of ferric hydroxide, silicic acid, organic matter,and possibly aluminium hydroxide, with small amounts of calcium,magnesium, potassium, and sodium.It showed marked colloidal pro-perties and to it is attributed much of the colloidal characteristicsof the soil. Its power of absorbing gaseous ammonia and dyestuffswas investigated, and on this is based a method for estimating theamount present in soils ; in the case examined, this was 28 per cent.,the clay on the American basis (0.005 mm. diameter) being 35.9 percent. The material is called " ultra-clay " ; it may be substantiallythe same as " clay " in the British sense (0.002 mm. diameter).Soil Acidity.Many soils are greatly improved by the addition of lime, and theobvious explanation is commonly put forward that they have insome way become acid and therefore infertile, but that fertility isrestored on neutralisation.The explanation was seriously calledin question when it was shown that absorption would account formany of the observed facts, and the tendency in recent years hasbeen to analyse the phenomena more closely.19l5 J. Marcusson, Eoc. cit.; 2. angew. Chem., 1921, 34, 437; A., ii, 590.16 Sven OdBn, Koll. Chem. Beihefte, 1919, 11, 75; A., i, 393.1 7 E. Blanck and F. Preiss, J. Landw., 1921, 49, 73.l * C. J. Moore, W. H. Fry, and H. E. Middleton, J . Iltd. E'ng. Cherri., 1921,For critical discussion, tiee E. ,4. Fisher, J . A y r i c . Xci., 1921, 11, ID;13, 527.:I., i, 215; A.Demolon, ,Inia. Sci. Agron., 1920, 37, 97.H 196 ANNUAL EEPORTS ON THE PROGRESS OF CHEMISTRY.An acid filtrate is obtained when a solution of a neutral salt ispoured through the soil. In t'he case of potassium nitrate and sodiumchloride, this has been traced to aluminium and iron rendered solubleby basic exchange; whilst in the case of calcium acetate andpotassium acetate it is due to acetic acid liberated either by re-placement of the hydrogen of hydrous silicates or by selectiveabsorption of the basic element in the salt solution.20Other causes of acidity have been investigated. It is not clear,however, that the true acidity as measured by hydrogen-ion con-centration is ever sufficient in nature greatly to affect the growthof plants.It is easy to be misled by the results of laboratoryexperiments. Degrees of acidity which proved inhibitive to micro-organisms such as Axotobacter and Actinomycetes had no observableeffect on the growth of wheat in culture solutions.21 Moreover,crops grown in sand cultures showed a higher degree of tolerance ofacidity than those grown in culture solutions.22 Indeed, sandcultures containing solutions of P,, 23 value 3 and therefore acidgave better growth than those more nearly neutral. I n the lattercase, however, the plants were chlorotic, and it is possible that thcresults are due to lack of available iron. Natural soils present evenmore complexity, since they show a high degree of buffering, whichcoarse sand doesMeanwhile, however, results are being accumulated and thequestion of method is important.The colorimetric method fordetermination of PH values is so much more rapid than the electro-metric method that it would be universally adopted if i t were equallytrustworthy. A careful examination has revealed 25 some of itsdefects and has emphasised the effect of fineness of division of thesoil.Methods of controlling the soil reaction are also being worked out.It is suggested26 that addition of sulphur to soil might produceacidity which would be useful in checking the potato scab organism(Actinomyces chromgenus, Gasperini). Good field results arerecorded, especially where the organism that oxidises the sulphuris added; the yield of potatoes was increased by 50 per cent.,whilst the percentage of unsaleable scabby potatoes fell from 58 to29 per cent.of the totalSee also J. J .Mirasol, ibid., 1920, 10, 153; A., i, 88.20 R. H. Robinson, Soil Sci., 1921, 11, 353; A., i, 644.21 H. F. A. Meier and C. F. Halstead, ibid., 1921, 11, 325.22 A. G. RlcColl and J. R. Haag, ibid., 1921, 12, 69.23 PH is the expression used for -log[H'].24 R. E. Stephenson, Soil Sci., 1921, 12, 145.2 5 E. A. Fisher, J. A g ~ i c . Sci., 1921, 11, 45.2 6 J. G. Lipman, A. L. Prince, and W. A. Blair, Soil Sci., 1921, 12, 197.27 W. 1%. Xartin, ibid., 1921, 11, 75; see also J . G . Lipman, A. W. Blair,W. H. Martin, and C. 8. Beckwith, ibid., 11, 87AGRICULTURAL CHEMISTRY AND VEGETABLE PIIYSIOLOGY. 197Another direction for utilising the acidity produced by additionof sulphur to soil is in removing the last of the alkalinity fromalkali soils after most of the salts have been washed out by irrigationwater.28The converse problem of reducing acidity by addition of lime or ofcalcium carbonate has been studied.The relationship betweenadded calcium hydroxide and P, value (as measured by electro-metric titration) is not simple,29 and some of the acid soils, forexample, in Oregon, do not respond to lime treatment.30 Noexplanation is forthcoming and further work is called for. More-over, it appears that soils contain not only calcium but magnesiumcarbonate also, and these do not behave alike.31I n general, however, acidity is rectified by addition of calciumcarbonate, and from the practical point of view it is desirable tohave some method that will show how much must be added to soilto ensure a neutral reaction.The Hutchinson-McLennan methodis shown to give useful indication^.^^ In addition to calciumcarbonate, other materials can be used ; experiments are recordedwith a slag described as ‘‘ dicalcium silicate.” 33Soil problems, however, are very complex and lime must not beregarded solely as a neutralising agent. Reference has already beenmade to the chlorosis induced in sand cultures when neutrality wasmaintained. Other observations indicate that the chlorosis inducedby lime in calcareous soils is due to depression in the availability ofiron. Evidence from ash analysis of chlorotic plants seems topoint to lack of iron as one cause of the chlorosis, a possible con-tributory cause being excess of lime (see p.208). Rice becamechlorotic in calcareous soils with ordinary percentages of water, buti t made normal healthy growth when the soil was submerged. It issuggested that special roots are formed under submerged conditionsbetter able to assimilate iron than the ordinary root.34A further effect of lime, which is often harmful, is to influence thepotash supply to the plant.35 It appears that potassium nssimila-tion by plants iw adversely affected by lime when only small amountsof potassium are present. In practice, this particular difficultlycan be overcome by supplying potassic fertilisers.Furfher, the phosphate supply is affected by calcium carbonate.2 8 P.L. Hibbard, SoiZSci., 1921, 11, 385; J. L. Lipman, ibid., 1916,2,205.29 C. 0. Swanson, W. L. Latsliaw, and E. L. Tague, J . Agric. Res., 1921, 29,30 R. H. Robinson and D. E. Bullis, Soil Sci., 1921, 11, 363 ; A., i, 644.32 Ch. Brioux, Ann. Sci. Agron., 1920, 37, 233.33 C. J. Schollenberger, Soil Sci., 1921, 11, 261.34 P..L. Gile and J. 0. Carrero, J . Agric. Res., 1920, 20, 33.35 I?. Ehrenberg, Landw. Jahrb., 1919-20, 54, 1.855.F. Hardy, J . Agric. Sci., 1921, 11, 1 ; A., i, 215198 ANNUAL REPORTS ON TfIE PROGRESS OF CHEMISTRY.The retention by soil of the P,O, of superphosphate is regarded36as a chemical interaction if calcium carbonate is present, but as aphysical adsorption if it is absent. In the former case dicalciumphosphate is formed so rapidly that the whole of the phosphate isprecipitated within a very restricted range : this becomes slowlyconverted into tricalcium phosphate.The physical adsorption in non-calcareous soils is rather differentand less rapid, so that the phosphate washes further down into thesoil.On non-calcareous soils, therefore, phosphatic manuringshould be more effective than on calcareous soils.As always happens in soil investigations, it is necessary to dis-tinguish clearly between the phenomena observed in soils devoidof vegetation and those on which plants are growing. The formerpresent the simpler case and are necessarily studied first; theplant introduces so much complication that even now little hasbeen ascertained with certainty.The relationships between soilreaction and absorption of ions are complicated in presence of thegrowing plant by the circumstance that different plants vary intheir power of absorbing nutrients from the soil: maize couldabsorb difficultly soluble phosphates from acid soils only ; mustardcould take it under more nearly neutral condition^.^'These various observations must not, however, be taken asindicating that acid soils are in general more favourable thanneutral soils for the yiclding up of nutrients to the plant. It istrue that excess of calcium carbonate seems to be harmful in somecases, but there is also evidence that plants usually obtain phos-phates more easily from neutral than from acid soils.38Effect of Salts on Soil.Just as lime has a complex action on soil SO also do various salts.There is an exchange of bases 39 which may lead to an acid reaction,as already stated. There are also important physical effects arisingout of the flocculation of clay by dissolved salts.These have beenstudied a t Rostock in an important investigation by Nolte : 40 theyhave also received attention in America. In the American investi-gations, sodium salts cause clay to become harder and less permeableto water. This is objectionable in regions where irrigation isnecessary, and in such cases the water must be examined to see if it36 W. H. Harrison and S. Das, Pusa Memoirs Chem. Series, 1921, 5, No. 9.37 M. Wrangell, Landw. Versuchs. Stat., 1920, 98, 209.38 G. S. Fraps, Texas Agric. Expt.Station Bull., 1920, 267; also 0. 11.39 For det,ails, see W. P. Kelley and A. B. Cummins, ibid., 1821, 11, 139;4O 0. Nolte, J . Landw., 1919, 67, 267.Shedd, Soil Sci., 1921, 11, 111.A., i, 388AGR.ICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 199contains more sodium and potassium than calcium and magnesium ;if so, its continued use is likely to be harmful. The suggestion ismade that addition of soluble calcium or aluminium compounds tothe water might overcome the d i f f i ~ u l t y . ~ ~Soil Analysis.One of the most difficult problems for the agricultural chemist isthat of soil analysis. He is expected to analyse soils and on thebasis of his results to give recommendations as to manuring. Un-fortunately, the problem is particularly difficult ; in most casesinsoluble on our present knowledge.The trouble arises from thefact that no two methods give the same results; it is possible fromthe Rothamsted soils to extract percentages of K20 varying from0.001 to 5 per cent., according as one extracts with water or adoptsdrastic fusion methods. Two important summaries and discussionsof the German results 42 show the relative importance there attachedto the various factors, and indicate high-pressure steam as a suitableagent in potash determinations. Another suggestion is that t,heratio of soluble to total K20 or P205 (using 1 per cent. citric acid asthe agent for soluble P205 and 10 per cent. hydrochloric acid forsoluble K20) is more useful than either figure taken separatelyin explaining fertiliser results.The authors carefully disclaim,however, any predictions of fertiliser requirement^.^^ It is suggestedalso that the plant is able to extract from a soil more K20 but lessP20, than is dissolved by 1 per cent. citric acid.The use of O*2N-nitric acid for soil analysis has been furtherdiscussed 44 and also that of hydrochloric a ~ i d . ~ 5Mechanical analysis of at present a very tedious process,promises to be simplified by using sodium carbonate as the defloccu-lating agent instead of ammonia, whilst the use of the centrifugestill further accelerates the process.47Finally, a promising attack has been made on the exceedinglydifficult problem of determining the amount of colloidal materialin soils.4841 C. S.Schofield and F. B. Headley, J. Agric. Res., 1921, 21, 265.42 J. Konig and J. Hasenbaumer, Landw. Jahrb., 1920, 55, 184; J. Konig,J. Hasenbgumer, 0. Kleine-Mollhoff, and M. L. Plouski, ibid., 1921, 56, 439.43 0. Lemmermann, L. Fresenius, and H. Wiesmann, Landw. Versuchs.Stat., 1921, 98, 155.44 0. M . Shedd, Soil Sci., 1921, 11, 111.45 F. Munter, Landw. Versuchs. Stat., 1919, 94, 181.48 For a discussion of methods, see U. Pratolongo, Ricerche R. Scuola Sup4 7 A. F. Joseph and F. J. Martin, J . Agric. Sci., 1921, 11, 293.48 C. J. Moore, W. H. Fry, and H. E. Middleton, J. Ind. Eng. Chern., 1921,d’Agric. di Milano, 1920, 6, 97.13, 527; A., ii, 608200 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.hydration or water of solid solution ; unavailableEnvironmental Conditions.A detailed study of soil temperatures 49 brings out the interestingfact that the top 6 inches of soil is on the whole rather warmer thanthe air, so that the temperature conditions are more favourable tomicro-organisms and plant roots than might be expectedAGRICULTURAL CHEfiIIYTRY AND VXGETABLE PHYSIOLOGY. 201tration of cell sap has been shown to depend on the moisture contentof the soil; apparently this is the chief factor concerned.A lowconcentration (induced by high moisture content) is associated withrapid vegetative growth ; a high concentration with slower growthbut with fruit bud f o r m a t i ~ n . ~ ~Soil Organ is rlzs.The relationships existing between the growing plant and themicro-organic population of the soil are gradually being elucidated,56but the papers published this year deal largely with matters ofdetail.The range of substances decomposable in thc soil bymicro-organisms is remarkable, and includes some of the verystable hydrocarbons such as paraffins, benzene, toluene, etc. ; 57i t is even suggested that soil organisms could be used in gas analysis€or discriminating between certain hydrocarbons.Most of the investigations, however, deal with the nitrogen cycle.Many organisms are capable of decomposing protein with formationof ammonia; it is not usual to discriminate between these in soilinvestigations, but only to count them; a comparison has beenmade of different counting methods adopted. 58I n nature, the ammonia is almost invariably oxidised bacteriallyto nitrate, and attempts have several times been made in France toutilise this action on the manufacturing scale : a new method issuggested in which ammonium salts percolate through peat orvolcanic scoriae.59The bacterial fixation of nitrogen continually attracts attention :i t is effected by two groups of organisms, Axotobacter and Clostridium.The former is usually regarded as the more important ; i t assimilatesnitrogen more slowly at ordinary laboratory temperature than at27", but fixes more per unit of mannite consumed.60 The effectsof coloured light and of uranium salts have also been studied. Ainethod of estimating the numbers of Clostridium in the soil hasbeen devised,61 and the view is put forward that i t is more numerousthan Axolobacter and probably p-'li~ys a more important part in thefixation of nitrogen.65 H. S.Reed, J. Ryric. Bes., €921, 21, 81.56 For a recent summary, see E. J. Russell, Ann. Sci. Agron., 1921, 38, 49.57 J. Tausz and M. Peter, Centr. Bakt. Par., 1919, [ii], 49, 497; A., 1920,58 Z. N. Wyant, Soil Sci., 1921, 11, 295.59 E. Boullanger, Ann. Inst. Pasteur, 1921, 35, 575; A., i, 836.6O E. Kayser, Cornpt. rend., 1920, 171, 969; A., i, 79; ibid., 1921, 172,1Y3, 403, 939, 1133; A . , i, 208, 479.61 G. 'I'ruffaut and N. Bezssonoff, ibid., 1921, 172, 1319.i, 911.11 202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A third group of organisms acts in symbiosis with leguminousplants and is closely related in activity to the growth of the plant.62Morphologically they present many features of interest.63Other organisms seem concerned in the loss of nitrogen from soil,some of which is presumably brought about by an evolution ofgaseous nitrogen. Although little is known of the mechanism ofthe process, further measurements have been made of the quantitiesinvolved. In the New Jersey cylinder experiments, which extendedover a period of twenty ~ e a r s , ~ 4 the loss has usually been of theorder of 100 lb. per acre for the first fifteen years; where, however,green manure was used, there was no loss, but a gain.Partial Xterilisation.Further results have been published65 showing the increase ofcrop yield resulting from heat treatment of soil. The effectspersisted for several crops ; they varied somewhat, however, withthe different layers of soil.The introduction of untreated soil didnot wholly counteract the effect of steaming, showing that thedecomposition of soil materials is a potent factor in determiningthe effect.Owing to the cost and limited application of heat, efforts arecontinued to find some chemical agent capable of modifying thesoil population in the desired direction. Studies have been madeof p-dichlorobenzene, which gave promising results against thePeach-tree Borer (Sanninoidea exitiosa, Say), a destructive pest ofpeach trees,G6 and of the physical and other conditions affecting theuse of carbon disulphide as a soil sterilising agent.67Phenol has also proved effective, but it is liable to certain obscureinteractions with soil constituents and to biochemical decompositionin the soil whereby its value is much diminished.68Chloropicrin and formaldehyde are useful partial sterilisingagents,69 and their effect on germination has been discussed.7062 A.L. Whiting and W. R. Schoonover, Soil Sci., 1920, 10, 441.63 F. Lohnis and R. Hansen, J . Agric. Res., 1921, 20, 543.64 J. G. Lipman and A. W. Blair, Soil Sci., 1921, 12, 1.65 Viscount Elveden, J . Agric. Sci., 1921, 11, 197.6 6 A. Peterson, Soil Sci., 1921, 11, 305.6 7 B. R. Leach, ibid., 1921, 10, 421.6 8 N. N. Sen Gupta, J . Agric. Sci., 1921, 11, 136.69 E. J. Russell, J . Roy. Hort. SOC., 1920, 45, 237.70 E. Mihge, Compt. rend., 1921, 172, 170 (chlaropicrin); A.H. Hurd, J.Agric. Res., 1920, 20, 209 (formaldehyde)AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 203T h e C h e m i s t r y of t h e Living P l a n t .Photosynthesis.The rapid production of sugar in the leaf from carbon dioxidecontinues to evoke a great volume of research. Baeyers’ originalhypothesis still holds the field, and there is no generally recognisedalternative to the view that the first product is formaldehyde, whichsubsequently condenses to sugar. The key-sugar in carbon ineta-bolism, both in the up- and the down-grade processes, appears tobe glucose. The pentoses, however, are invariably present andplay an important part in plant processes, entering into the com-position of the nucleus, of certain cell-walls and of mucilage,71and helping considerably in determining succulence.72Numerous investigations have shown that formaldehyde is obtain-able in circumstances more or less comparable with those obtainingin natural photosynthesis. The more notable papers include onefrom a physico-chemical laboratory where the chemical pitfalls areavoided,’3 and one from a physiological laboratory where the plantconditions are fully re~ognised.~~ In the latter it is claimed thatthe production of formaldehyde results from the decomposition ofchlorophyll and is not directly dependent on the presence of carbondioxide. An interesting discussion, which, moreover, invitescontroversy, is contained in the Hugo Muller lecture.75 An alterna-tive view is put forward by Maze in which the principal part isassigned to hydroxylamine.This base is supposed to arise in theleaves by reduction of nitric acid (nitrates being the recognisednitrogenous nutrients of plants and absorbed in considerablequantities from the soil); i t combines with carbon dioxide aridchanges as follows :C02,NH2*OH = H*CHO + HNO,,also 2C02,NH2*OH = CH,(OH)*CHO + ZHNO,.These products are actually found in the leaves of the elder.The glycollaldehyde may become reduced to acetaldehyde ; thisreacts to produce lactaldehyde and nitrous acid,CH,*CHO + C02,NH2=OH = CH,*CH(OH)*CHO + HNO,,71 F. F. Blackman, New Phytologist, 1921, 20, 2.72 H. A. Spoehr, “The Carbohydrate Economy of the Cacti,’’ Carnegie73 E. C. C. Baly, I. M. Heilbron, and W. F. Barker, T., 1921, 119, 1025.74 W.J. V. Osterhout, Amer. J. Bot., 1918, 5, 511; A., i, 263.75 B. Moore, T., 1921, 119, 1555.Inst. Pub. No. 287, 1919.lp: 204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which occur in the leaves of the poplar. It is not difficult in thisway to build up substances of any desired degree of elab~ration.~~Whatever view is taken as to the actual course of photosynthesis,it is known that potassium plays an important part, although thereis not necessarily a specific effect. It is shown that wheat canproduce and translocate a certain amount of starch in presence ofonly little of this element.77 It does not appear that the potassiumis in organic combination in the plant, since it can all be extractedwith water. 78Iron also has always been regarded as essential for the productionof chlorophyll.It is now maintained that the magnesium salt ofpyrrolecarboxylic acid serves instead, and in culture solutionsdetermines the formation of chlorophyll even in absence of iron.It is therefore suggested that the function of iron in the leaf is toact as catalyst in the formation of pyrrole, which is regarded as thecentre of the chlorophyll complex. 79Other inorganic nutrients are essential to plant growth, andspecial importance has always been attached to nitrogen, potassium,and phosphorus because of the striking results obtained by the useof their compounds as fertilisers. Attempts have been made tofind quantitative relationships between the amounts of plantnutrients supplied and of the subsequent plant growth.The oldidea that growth was proportional to the quantity of fertiliser hadlong ago to be abandoned; it was followed by Mitscherlich's viewthat the effect of a nutrient salt (or other factor) is proportional tothe decrement from the maximum obtainable when that salt orfactor is present in ample quantity. This view has the merit thatit is readily expressible in the form of a logarithmic equation, theconstants of which hold out attractive possibilities for the agricul-tural chemist; it has, however, evoked a storm of criticism inGermany,g0 and in any case it appears to be too simple a statement,as the results are more readily expressible by a sigmoid than by alogarithmic curve. 81171, 1391; A., i, 151.7 6 P.Maz6, Compt. rend., 1921, 172, 173; A., i, 209. See also ibid., 1920,77 T. 0. Smith and 0. Butler, Ann. Bot., 1921, 138, 189; A., i, 482.76 S. Kostychef and P. Eliasberg, 2. physiol. Chem., 1920, 111, 228; A.,'9 B. Odd0 and G. Polacci, Gazzetta, 1920, 50, 54; A., 1920, i, 407.i, 83.Among recent papers are A. Mitscherlich, Landw. Jahrb., 1921, 56, 71 ;B. Baule, ibid., 1920, 54, 493; A. Mayer, Landw. Versuchs. Stat., 1919, 94,247. For a useful r6sum6, see E. Lang, Landw. Jahrb., 1920, 55, 337.81 Rothamsted Report, 1918-20, p. 14; A. Rippel, Landw. Vemuchs.Stat., 1921, 9'9, 357. For a discussion of the distinction between growthrate and h a 1 growth, see C. West, G. E. Briggs, and F. Kidd, New Phytologist,1920, 19, 200AGRICULTURAL CHEMISTRY ANT) VEGETABLE PHYSIOLOGY.205There has been much discussion, initiated by Shive and Totting-ham's earlier work, as to the need for some definite physiologicalbalance 'between the various plant nutrients ; it is, however, shown 82that there isno " best " solution for plant growth : aconsiderablerangeof mixtures is possible, although " poor " solutions can be made.s3Some proportionality between CnO and MgO seems indicated byconsideration of the analyses of plant a ~ h . ~ 4 A detailed study ofthe potato in sand cultures is also rep0rted.~5Further, it is possible to effect disturbances in plant nutritionby altering the course of absorption of the nutrients. Assimilationbecomes abnormal when a plant root is divided among severalnutrient solutions from each of which one essential nutrient iswithheld.It is suggested that the cause lies not so much with theactual absorption of the nutrient as with the subsequent transloca-tion, and values have been calculated for nitrogen, phosphoric acid,and potassium which show a reasonable measure of agreement withthe results actually found.86The older agricultural chemists confined themselves almostexclusively to the three nutrients nitrogen, phosphorus, and potass-ium; of recent years, however, the French chemists have directedattention to the importance of other elements. Berfrand firstinsisted on the importance of manganese and now shows 8' that itis invariably present, the supposed exceptions of Maumene beingnon-existent. Copper is shown to be invariably present in plants;it is subject to translocation and migrates t o points of greatestvitality as if it played an active part in intracellular metabolism.88Iron presents a somewhat more complex problem, since it existsin the plant in two forms which are not readily distinguished : a8Fe,03 deposited by evaporation in the leaf or absorbed in the cellularrnembrane~,~~ and as an organic complex comparable with Bunge'shaematogen ; the latter becomes translocated and moves towardsthe centres of active life and reprod~ction.~~62 A.R. Davis, Soil Sci., 1921, 11, 1.Confirmed also by L. H. Jones and J. W. Shive, J . -4gric. Res., 1921,21, 701.84 H. Lagatu, Compt. rend., 1921, 172, 129; A., i, 214.8s E. S. Johnston, XoiZ Xci., 1920, 10, 389.E 6 P.L. Gile and J. 0. Carrero, J . Agric. Res., 1921, 21, 545.G. Bertrand and Mme M. Rosenblatt, Compt. rend., 1921, 173, 333;A., i, 759; J. S. Jones and D. E. Bullis, J . Ind. Eng. Chem., 1921, 13, 524;A., i, 840. For a soil study, see P. Nottin, Ann. Sci. Agron., 1920, 37, 228.See alsoa suggestive paper by these authors in Ann. Xci. Agrom., 1921, 38, 113.For this inorganic iron, see H. W. Jones, Biochem. J . , 1920, 14, 654;A., 1920, i, 909.L. Maquenne and R. Cerighelli, Cornpt. rend., 1921, 173, 273; A., i, 759.8 8 L. Maquenne and E. Demoussy, Compt. rend., 1920, 170, 87206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A study of iron nutrition has shown that the availability andsufficiency of a particular iron compound depends on the otherconstituents of the nutrient solution and on its hydrogen-ion con-~ e n f r a t i o n .~ ~ Thus ferric phosphate was of little value to plantswhen the nitrogenous nutrient was a nitrate; but it was quiteeffective when ammonium sulphate was used. On the other hand,ferrous sulphate was effective in presence of nitrates, but toxicwhen used in conjunction with ammonium sulphate.Pot experiments suggest that small doses of boric acid cause anincrease in plant growth, but it is not clear that crop increases areproduced in the field. The subject is of some importance in America,because boron occurs in some of the naturally occurring potassiumsalts which have been proposed for use as fertiliser ; it is found that3 to 5 lb. per acre is the largest permissible dose of anhydrous borax,and there was no evidence of any beneficial effect with this or smallerquantities .92Finely powderedsulphur, when added to soil in certain cases, increases plant growth ;the action is considered to include a t least three factors; some ofthe sulphur is oxidised by bacteria to sulphuric acid, which bringsinto solution more phosphate, potassium, etc.; it seems to stimulatethe activities of the ammonifying, the nitrifying, and the noduleorganisms ; and apparently 93 it stimulates the production of starchin plants.Possibly some such action may explain the curious observationthat beans germinated and grown in distilled water became etiolatedand died for want of food, whilst large reserves still remained in thecotyledons.On the other hand, growth continued in soil andexhaustion of reserves was much more complete.g4It is probable that all these effects are complex.Plant Constituents.This branch of the subject belongs properly to organic chemistry,and only brief reference will be made to it here. The fundamentalproduct is starch, but its transformations cannot be followed withcertainty because no satisfactory method exists for its determinationn plants. Taka-diastase converts it into maltose and dextrose only,and was therefore proposed 95 as a suitable analytical agent ; it nowappears,96 however, that this substance does not give concordant1921, 11, 93.91 L. R. Jones and J. W. Shive, J. Agric. Res., 1921, 21, 701; Soil Sci.,92 J. R.Neller and W. J. Morse, Soil Sci., 1921, 12, 79.93 G. Nicolas, Cornpt. rend., 1921, 172, 85.94 G. D. Buckner, J . Agric. Res., 1921, 20, 875.95 W. A. Davis and A. J. Daish, J . Agric. Sci., 1914, 6, 152.96 E. Horton, {bid., 1921, 11, 240AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 307results, and indeed doubt is expressed whether any ordinary enzymewould do so. Until he can follow the more important changes in thegrowing plant, the agricultural chemist is not as a rule directly con-cerned with questions of constitution of these various constituent^.^^The nitrogen compounds in plants are steadily being investigated.A method is suggested for extracting the protein from leaves byuse of water saturated with ether.98Nitrogen compounds have been extracted and examined fromlucerne ~eed,~9 pecans, peanuts, and kafir,l mungbean (Phaseolusaureus, Roxburgh), coconut 3 (Cocus nuciferu), cohune nut (AttaleaCohune),* and the egg plant (Solanurn melongem, L.).6Some work has also been done on the formation of alkaloids.6Annett has continued his studies of the morphine content ofpoppies and has made a survey showing the quantity of opiumproduced from this crop in the more important districts in India.That most remarkable of all chemical processes, the synthesis ofnitrogen compounds from gaseous nitrogen in the nodules on theclover root, has been further examined but not yet elucidated; 8about 60 per cent.of the soluble nitrogen in the nodules of soy beanis precipitated by phosphotungstic acid ; apparently, however, noglobulin is present and only a smaU amount of albumin.9 Fieldexperiments show the great advantage of inoculation for soy beans,and on certain soils, for canning peas.1°s7 Among the papers are : “ Starch,” M.Samec and R. Haerdtl, Koll.Chem. Beihefte, 1920, 12, 281; A., i, 226; P. Karrer et al., Helu. Chim. Acta,1921, 4, 678; A., i, 768. “Cellulose,” K. Hess, Helv. Chim. Acta, 1920, 3,866; &4., i, 12; P. Karrer and F. Widmer, ibid., 1921, 4, 174; A., i, 310;M. Samec and J. Matula, Koll. Chem. Beihefte, 1919, 11, 37; A , , i, 397;K. Freudenberg, Ber., 1921, 54, [B], 767; A., i, 400; A. Cleve von Euler,Chem. Ztg., 1921, 45, 977; A., i, 769. “ Wood,” H. Wislicenus, Kolloid Z.,1920, 27, 209; A., i, 84; F.Lenze, B. Pleus, and J. Miiller, J . pr. Chem.,1920, [ii], 101, 213; A., i, 163.98 A. C. Chibnall and S . B. Schryver, Biochem. J . , 1921,15, 60; A., i, 482.ss H. G. Miller, J . Amer. Chem. SOC., 1921, 43, 906; A., i, 486; see alsonext reference.C. T. Dowel1 and P. Menaul, J . Biol. Chem., 1921, 46, 437 ; A . , i, 644.C. 0. Johns and H. G. Waterman, ibid., 1920, 44, 303; A., i, 84.D. B. Jones and C. 0. Johns, ibid., 291; A., i, 66.C. 0. Johns and C. E. F. Gersdorff, ibid., 1920, 45, 57; A., i, 212.Kiyohisa Yoshimura, J . Chem. SOC. Japan, 1921, 42, 16; A., i, 296.See G. Ciamician and C . Ravenna, Atti R. Accad. Lincei, 1920, [v], 29,7 H. E. Annett, H. Das Sen, and H. DayalSingh, Puea Memoire Chem.For further details of the facts, see A.L. Whiting and W. R. Schoonover,W. H. Stroud, ibid., 1921, 11, 123; A , , i, 387,i, 416; A., i, 85.Sem’m, 1921, 6, No.1; H. E. Annett, Biochem. J . , 1920, 14, 618; A., i, 87.Soil Sci., 1920, 10, 411.10 E. B. Fred, ibid., 469, 479208 ANNUAL REPORTS ON THE FROGR12SS OF C’HEMTSTR’T.The function of hydrocyanic acid has been discussed, but nodefinite conclusion i cachcd.llColowing 31aterials in Plants.The only colouring material of agricultural interest is indigo,which is still grown to an important extent in India. There is somecontroversy as to the conditions under which the greatest productionof indican is obtained; A. and G. L. C. Howard l2 maintain thatthe yield is improved by organic manures, but not particularly bysuperphosphate ; whilst W.A. Davis insists that phosphates areof prime importance.The admirable discussion on colouring materials in plants givenby Prof. R. Robinson before the British Association a t Edinburghis of very great interest to agricultural chemists.Calcifuges and Calcicolous Plants.Plants which fail to grow on calcareous soils are called calcifuges,whilst those which occur there more frequently than on other soilsare described as calcicolous. The cause of the difference is obscure(see p. 197), but a promising mode of study has been opened up byM. C. Rayner,13 which offers possibilities considerably in advanceof anything hitherto available. A technique has been devised forgrowing a typical calcifuge Calluna and its associated fungusseparately in culture solutions.It is shown that Calluna will grownormally in an aqueous extract of a non-calcareous soil, whiIst itfails to make such good growth in the extract of a calcareous soil.Clearly, therefore, the soil factor concerned is not exclusivelyphysical, since it is transmitted to the extract ; it does not appear tobe concerned entirely with the reaction, since the favourable extractwas neutral and the unfavourable one only slightly alkaline. Itshould not prove impossible to trace the cause of the unsuitabilityof the extract of calcareous soil.Fertilisers.As in past years, this branch is dealt with fully in the Report tothe Society of Chemical Industry, and only brief reference will bemade here to features of special interest.The problem of increasing the supply of organic matter in the soil11 L. Rosenthaler, Schweiz. ApotL-Zeit., 1920, 48, 137; 1921, 49, 10, 22;12 Pusa Mem. Bot. Series, 1021, 11, No. 1.1s 31. C. Rnyner, J . EcoEogy, 1921, 19, GO.A., i, 484; P. Menaul, J. Biol. Chem., 1921, 46, 297; A . , i, 484AGRICULTURAL CHEMISTRY ANT) VECTETARLTC PHVSIOLOCIY. 209has been attacked by ascertaining the conditions under whichstraw decomposes to form humus, and then carrying out the decom-position on the farm. The necessary conditions are, air and watersupply, a nitrogen nutrient for the organisms effecting the decom-position, and sufficient calcium carbonate to ensure neutrality. Itis claimed that an effective fertiliser can be produced from straw inthis way, and that the process can be worked on farms where in-sufficient farmyard manure is obtained during the ordinaryoperations .I4Nuch interest has been aroused in technical circles by theannouncement in Germany that artificial enrichment of the atmo-sphere in carbon dioxide was being practised successfully as a meansof increasing plant growth both in glasshouses and in the open.A patent has been taken out for absorbing this gas from flue andfurnace gases, then evolving it and delivering it in pipes near to thcroots of plants. So much interest has been aroused that themethod will probably be tested in this ~ 0 u n t r y . l ~E. J. RUSSELL.1 4 H. B. Hutchinson and E. H. Richards, J. Min. Agric., 1921, 28, 398.F. Bornemann, “ Kohlensaure und Pflanzenwachstum,” Parey, Berlin,1920; F. Riedel, Stuhl u. Eisen, 1919, 40, 1497; Mdllers Deut. Gartner Ztg.,July 20 and 30, 1921, where some illustrations are given; Chem. Ztg., 1920,585, 808

ISSN:0365-6217    

DOI:10.1039/AR9211800192

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

CRYSTALLOGRAPHY AND MINERALOGY.THERE is a very considerable amount of fruitful research in thesedomains of science to record as the product of the year 1921.After a short respite, during which it appeared as if grave difficul-ties were accumulating in the path of further progress in elucidatingthe structure of crystals by means of X-rays, a, remarkable stepforward has been taken, both as regards new methods and newground, that of organic chemistry. It will be convenient to com-mence with the latter most interesting departure first, althoughits publication has only occurred as this Report is being sent in.By the great kindness of Sir William Bragg, however, the writerwas supplied with the proof-sheets, and also had early access tothe models.X-Ray Analysis of Organic Substunces.An attempt had already been made by R.0. Herzog and W.Janckel to obtain information concerning the structure of someorganic compounds of the fatty series by means of the X-ray powdermethod of Debye and Schemer, but the difficulties met with appearto have been very, great, the interpretation of results proving well-nigh insuperable. Cellulose appears to have afforded the leastambiguous results, the elementary monoclinic cell of the space-lattice of the crystals of this substance having been found to containfour dextrose residues, which are of two types, two being of eachtype.But on November 11th (1921) Sir William H. Bragg,2 in hisPresidential Address to the Physical Society, which the writer wasprivileged to hear, announced the first result of a much moresuccessful attack on organic substances, by means of his ownmethods of X-ray analysis.He was led to begin with a few ofthe better crystallising aromatic compounds, especially naphthaleneand its derivatives, and for a reason which in itself is highly interest-ing. It will be remembered that the elucidation of the structureof the diamond was one of Sir William’s early successes, and sub-1 R. 0. Herzog and W. Jancke, 2. angew. Chem., 1921, 34,385; A., ii, 531.2 Sir W. H. Bragg, “The Structure of Organic Crystals,” Proc. Phye.SOC., 1921, 34, 33.21CRYSTALLOGRAPHY AND MINERALOGY. 21 1sequently Debye and Scherrer, and independently A. W. Hull,discovered the structure of graphite, by means of the powdermethod, and found it to be a trigonal one which is illustratedby the model of which a drawing is shown in continuous line inFig.1. Now the remarkable thing is, that if the top layer ofthe model be moved to the closer and rotated position indicated bythe dotted lines, the structure of the diamond is obtained. Itwill be recalled that in diamond the carbon atoms are arranged ona face-centred cube lattice, with also an atom in the centre ofevery alternate one of the eight cubelets into which the main cubeis divided. It thus consists of a series of puckered layers parallelto any given plane of the tetrahedron, and each carbon atom isstltsched to four others. The diamond cleaves along these layers.r.. ,..--. ;’ :. .‘.i . IConversion of Graphite to Diamond Structure.The structure of graphite shown in Fig.1 is conversely afforded bytaking two such layers of the diamond model and moving one ofthem away from the other, to the position corresponding to thatin Fig. 1. The exact configuration shown, in which the lines arepuckered, is that given by Hull, whereas Debye and Scherrer placethem in the same plane. Whether puckered or plane, however,these layers are clearly composed of six-carbon-atom rings. Nowthe very strong bonds between the atoms of these rings in thelayers of a diamond not only persist in the graphite structure,but are drawn somewhat tighter, while the distance separating thelayers in the latter is much greater than in the more symmetricaldiamond; the cohesion is thereby so much lessened between thelayers that graphite is one of the softest of substances, not onlysplitting readily in layers, but actually being useful as a lubricant.On the other hand, diamond is the hardest substance known.Th212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.shortest distance between each ptir of carbon atoms lying in thesame layer in the diamond is 1.54 A.U., while in graphite it is short-ened to 1.50; but the distance between two successive layers isincreased by 1.35 S.U., so that a carbon atom in graphite is nowequally distant from its three nearest neighbours of the next layer,namely, by the relatively large amount of 3.25 B.U., according toHull.These interesting facts regarding elementary carbon have causedSir William Bragg to believe that the hexagonal rings, whichpersist even in graphite, do so also throughout the aromatic com-pounds.He therefore assumes the benzene ring to be such a simplehexagonal ring, more or less puckered, of carbon atoms, whilstnaphtJhnlene is composed of double rings, and anthracene of triplerings. Csing Mull's spacings, the arrangement in naphthalene heFIG. 2.The Structure of Naphthalene.considers to be that shown in Pig. 2, which includes three naph-thalene molecules and parts of others. The ten carbon atoms,from A to J, form the double ring corresponding to one moleculeof naphthalene, while the six atoms A B C D E P form a benzenering. The centres of the atoms A and G are 0.71 A.U. above theplane, and the centres of D and J the same distance below the planeof the diagram, those of the rest of the atoms lying in the planeitself.Benzene is not an easy substance on which to commence the attack,as it is only solid below 6", its melting point.It is interesting torecall, however, that Debye and Scherrer believed that they hadobtained evidence that the molecule of benzene has the form of ahexagonal tablet, the edge of the regular hexagon having the length6.02 A.U., and the thickness of the tablet being 1-19 A.U.Naphthalene, C,H,, crystalhses in the holohedral, prismatic, class CRYSTALLOGRAPHY AND MINERALOGY. 213of the monoclinic system, possessing both the digonal axis ofsymmetry and the plane of symmetry perpendicular to it, the ratioof the axes being a : b : c = 1.3777 : 1 : 1.4364, and the axial anglep being 122" 49'.The very perfect cleavage is parallel to the basalplane (OOl), and thc other principal faces developed are (110),(2Oi), and (111). The density is low, 1.152,'The first results afforded by the X-ray spectrometer indicatethat the space-lattice of both naphthalene and anthracene is No. 13,the unit cell of which consists of a parallelepipedon with two pairsof rectangular faces, inclined a t the axial angle p, and one pair ofrhomboidal ones, as shown by the two cells in Fig. 3, the dimensionsfor naphthalene being a = 8.34, b = 8-05, c = 8-69 H.U. It wasnext found that two molecules are contained in each cell, the know-ledge being derived in the usual Bragg manner from the density,FIG.3.NAPHTHALENE ANTH R ACENEUnit Cells of Naphthalene and Anthracene.the actual weight of the molecule, the axial ratio, and the X-raymeasurements ; for it was found that the (100) and (010) spacingsare only half what they should be if each corner of the cell repre-sented a single molecule; for only one-eighth of a corner moleculeis assignable to this particular cell, each corner being the point ofcontact of eight adjacent molecules, so that the whole eight partscorrespond togethcr to one whole molecule within Che cell. Butthe spacing of (001) agrees, so there must also be a molecule a t eachof the points Y and Q in Fig. 3, each contributing half a moleculeto the cell.On proceeding next to anthracene, C14H10, the crystals cannot bcused similarly for the single crystal method, as they are only smallflakes; but by pressing a number of them against a flat disc, sothat all their (001) planes were parallel thereto, a determination ofthe (001) spacing was found possible, and the linear dimensionsof the unit cell were determinable.The crystallographic axialratio of anthracene is a : b : c = 1.4220 : 1 : 1.8'781, the axial angl214is 124" 24', and the density 1-15. There were found to be twomolecules to each unit cell, as in the case of naphthalene, and thedimensions afforded by the X-ray measurements were a = 8.7,b = 6.1, and c = 11.6. These values, as regards a and b and theaxial angle, were nearly the same as for naphthalene, but thec-length was 2.9 B.U. greater.Now this result is of the greatest importance, for if we acceptthat the double-ring naphthalene molecule a t each corner is replacedby the three-ring molecule of anthracene the increase in size shouldbe about 2.5 A.U. per molecule.Sir William Bragg'concludes,therefore, that the double- or triple-ring molecules lie along thevertical c-axis, and that the anthracene cell is longer than thatFIG. 4.ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.D -f GIACENAPHTHENEUnit Cell and Constitutional Formula of Acenaphthene.of naphthalene by the observed amount for this reason. Thelengths of the molecules of the two hydrocarbons, without allowingfor the hydrogen atoms, are 6.41 and 8.86 A.U. respectively, SOthat there is a, vacant space between the ends of the molecules forthe accommodation of the two p-hydrogen atoms. As regards theposition of the plane of the double- or triple-ring molecule, whichmust contain the c-axis, all the indications point to the probabilitythat it approximates to .the (010) symmetry plane ac, that the8-hydrogens of one molecule lie up against the corresponding onesof the next molecule, and that the (001) plane passes through themall.This (001) plane is then naturally the plane of cleavage, as isactually observed, the atoms being condensed and strongly attachedin the rings in the plane, and the cohesion a minimum in the per-pendicular direction. The a-hydrogen atoms, those on the sideCRYSTALLOGRAPHY AND MINERALOGY. 215of the double- or triple-ring molecule, lie up against the carbon atomsof the neighbouring molecules, and there is about 1 A.U.of spacefor them, an adequate amount.The forces between the molecules are weaker than the valencyforces, and of these weaker forces those between the p-hydrogenatoms are weaker than those between the a-hydrogen and carbonatoms. But these two weaker sets of forces are those which bindthe molecule into the crystal. The structure thus arrived a t is avery open one, as will be clear from Fig. 2, in which the smallercircles represent the hydrogen atoms.Three derivatives of naphthalene have also been studied, ace-naphthene and the a- and p-naphthols. A most interesting resulthas been afforded by acenaphthene, the structure and constitutionFIG. 5.Unit Cell and Constitutional Formula of a-Naphthol.of which are showii in Pig.4. While the molecule has been madelop-sided by the substitution of 2CH, for the two hydrogen atomson one side, the crystal itself is of higher symmetry than that ofnaphthalene, being holohedral orthorhombic (class S), with theaxial ratio a : b : c = 0.5903 : 1 : 0.5161. The X-ray analysis hasshown that there are in this case not two but four molecules in theunit cell of the space-lattice, the sides of which have the absolutelengths a = 8.32, b = 14.15, and c = 7.26 A.U. In fact, theenhancement of the symmetry, compared with that of naphthalene,has been produced by two of the four unsymmetrical moleculesbeing arranged mirror-image-wise with respect to the others, acrossone of the principal planes.There is a molecule a t each corner ofthe cell, and also one in the middle of each face. Those a t thecorners and also those at K and L lie parallel to AB, while those atM , N , &, and R, which between them contribute to the cell the othe216 ANNUAL REPORTS ox THE PROGRESS OF CMEMISTRI.two molecules which belong to it, slope the other way, parallel t oMN, while lying in the same plane.Considering now cx-naphthol, tthis substance forms monocliniccrystals of the holohedral prismatic class 5 like naphthalene, withan axial ratio of a : b : c = 2.7483 : 1 : 2-7715, and an axial angle117' 10'. There are found to be four mole-cules in the unit cell, which has the absolute dimensions a = 13.1,b = 4.9, and c = 13.4 A.U., and which is represented in Fig.5.These lop-sided molecules are placed as shown in the figure, andthey lie with their double-ring lengths " criss-cross," as representedby the diagonal lines, but they now lie edge-ways on top of oneanother instead of flat-ways, the a-axis and not the c-axis runningIts density is 1.224.FIG. 6.Unit Cell and Constitutional Formula of &Naphthol.along the line of crossings. The cleavage plane, however, againpasses through the @-junction. The hydrogen atoms fit verynaturally into their places, and link the tops of the moleculestogether in one (001) layer and the bottoms in the next layer. Thehydroxyl groups are thus brought rather close to each other, as ifthe attraction were bctween the oxygen atoms.It has only been possible to investigate the powder of @-naphthol,but this has been adequate to fix the absolute dimensions of themonoclinic space-lattice unit cell.Fig. 6 shows this lattice andalso the constitutional formula. The axial ratio is a : b : c =1.3662 : 1 : 2.0300, and the axial angle 119" 48'. The cell dimen-sions are a = 5.85, b = 4.28, and c = 8.7 A.U. It is found thatonly one molecule goes to a cell, but it is the small (quarter) cellindicated by strong lines in the figure. The removal of thehydroxyl group from the side to the end of the molecule has causeORYSTALLOGRAPRP ,4ND MINERALOGY. 217the cell to shrink in its lateral dimensions and to grow along thevertical asis, thus affording a striking confirmation of the assump-tlion that the molecules lie lengthwise along the vertical c-axis.The cleavage plane still cuts along the P-hydrogen junctions.This quarter cell, however, does not account for the full symnictry,for the dissymmetry of the single molecules would lower the crys-tallographic symmetry ; the four cells containing togcther fourmolecules, as in a-naphthol, are requisite to account for the holo-hedral symmetry of the crystal, and so the large cell of the figure,containing four molecules, is to be considered as the unit cell ofthe space-lattice, the " grosser unit '' of the crystal structure asthe writer terms it, exhibiting the true symmetry of the crystalsof the substance in question.The hydroxyl groups are drawntogether, so that pairs of molecules point opposiite ways.Thestructure is thus essentially similar to that of a-naphthol.A more limited study was found possible of a-naphtlaylamine, aunit cell of almost exactly the same rectangular shape and dimen-sions as acenaphthene being revealed, which contains four moleculesand has the dimensions a = 8.62, b = 14.08, c = 7.04 A.U., but aand c are interchanged in the two substances. The length of themolecule works out to be : for a-naphthylamine 8.25, for acenaph-thene 8.23, and for a-naphthol 5-31. The lop-sided molecules inall three cases are laid criss-cross on one another, whereas in naph-thalene itself they are arranged parallelwise, and the somewhatdifferent length, 8.7, of the naphthalene molecule is a consequence.Until benzene itself has been investigated, which will involvcspecial low-temperature arrangements, the well-crystallising benz-ene derivatives cannot be fully worked out, but as regards benzoicacid i t has been established that the (001) spacing is quite excep-tionally wide, 10.9 B.U., and that sheets of molecules lie in thesc!(001) planes a t this wide distance apart, the dimensions of the ccll,\!hich contains four molecules, being a = 5-44, b = 5.18, c = 21.8A.U., and the axial angle 97" 5'.Moreover, the shcets differ alter-nately, and the bridging appears to occur by the COOPT extendedgroups, a CO extension from one ring probably joining on to an013 extension from another ring. These bridges, however, are veryflimsy, and the crystals consequently flake a t the least touch.Thepowder method had to be used because of this property.'I'hc, Bearing of these New Results on iiolecular Structure.These interesting results with aromatic organic substances areconsidered by Sir William Bragg to agree extremely well with thework of Langmuir. The forces that bind atoms together are clearlyshown to be of more than one kind. The very strong valenc218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.bonds, whether due to electron sharing or other causes, are exempli-fied by all the linkings between the carbon atoms of the diamond,and also by those in the planes of the flakes of graphite. Quitedifferent, however, are the much weaker bonds between an atomin one graphite sheet and its three nearest neighbours in the nextsheet.It is this weaker second kind of bond which unites themolecules of the organic compound so as to form the crystal. Thecleavage is the indication of their weakest direction. These weakerbonds are definitely associated with special points on the molecule." When a crystal forms in a liquid, or by sublimation, the moleculethat attaches itself correctly, and with proper orientation to othersalready in position, is the one that stays there and resists thetendencies of other drifting and thermally agitated molecules toremove it. It is fixed by the attachment of certain points on itsown structure to certain points on the structure of the other mole-cules. The beautiful exactness of crystal structure is evidence ofthe precision with which this adjustment is made; and a t thesame time of the definite molecular form without which precisionwould be impossible."In the case of naphthalene the molecules arrange themselves sideby side, the a-hydrogens of each molecule seeking to attach them-selves to the carbon atoms of its neighbours, no valency bondsbeing concerned. This side-to-side combination is preferred to theend-to-end attachment, so that a crystal grows quickly out intothin sheets. Moreover, the particular geometry may permit amolecule to attach its active points to those of other molecules inmore than one way, producing twinning rather than a continuationof the previous regularity.The surface films studied by Langmuir, Adam, and others werenot aromatic compounds, but they exhibited similarly strongside-to-side attachments of their molecules as compared with end-onattachments.A film of oleic acid, for instance, is formed on waterwhen the hydroxyl ends of some of the molecules root themselvesin and are held quietly by the water, while other molecules link onside by side and the film thus spreads over the water. The arrange-ment parallelwise of the long-chain molecules, the swarm of Bose,of the substances forming the " liquid crystals " of Lehmann isprobably similar, ammonium oleate, C,,H,,(NH,)O,, being one ofthe best known cases, the length of the molecules themselves inthese long-chain cobpounds facilitating the process.Sir William Bragg finally concludes that " the arrangement ofmolecules in crystals .. . cannot be fully explained as due to forceswhich are merely functions of the distances between their centres.Confining ourselves to cases where there is no obvious separatioCRYSTALLOGRAPHY AND MINERALOGY. 21 9of electron charges, as there is none in the crystals described above,it is clear that we must think of molecules as bodies of very dehiteform. These attachments to one another are made a t definitepoints, and the forces there exerted may have very short ranges.The molecules are locked into crystal structure when attachmentsare made at sufficient points, and the whole has the stability of anengineering structure.”This very clear result of Sip William Bragg’s work on the aromaticcarbon compounds will materially assist in correcting the verypremature statements that have been made by some authors,even by Prof.von Groth, soon after the first results of X-rayanalyses of very simple binary compounds and elementary sub-stances were published, that chemical molecules do not exist inthe crystalline condition.has felt impelled to protest strongly againstthis very improbable conclusion, and has pointed out that “ therecan be no question but that the growth of a crystal is to be attributedto the special properties of the surface of the solid crystal alreadylaid down, whereby further accretions of growth occur,’’ and that“the whole process of the passage from liquid to crystal is socontinuous, and the natural succession of phases-gas, liquid, liquidcrystal, and true solid crystal-follow so unbrokenly, that t o denythe continued existeiice of the molecule at any stage is illogical.“ The fact that the pcrsistence of the molecule is not absolutelyessential to the geometlrical explanation of crystal structure is nota valid argument for denying that persistence.. . . The closeapproximation of the molecules in the act of crystallisation mayyet occur without destruction of the interatomic forces whichretain the molecules as such. There may be a certain amount ofpooling of the chemical affinities when the atoms are brought intosuch close neighbourhoocl that those belonging to different moleculesare little if any further removed from each other than those of anyonc and the same molecule; indeed it is likely that these forcesexerted a t close quarters by the atoms of one molecule on those ofother approaching molecules together constitute the directiveforce of crystallisation, which determines the type of crystalstructure produced.In any case, at the first opportunity, such asthat afforded by solution or fusion, for instance, the same moleculesor others indistinguishable from them are again restored as freelymoving separate entities. Also only concentrated, indeed super-saturated, and not dilute, solutions are concerned in crystallisation,so that electrolytic dissociation and ionisation are excluded.”The present writerA. E. H. Tutton, “ Crystallography and Practical Crystal Measurement,”2nd edition, now on point of publication, Macmillan and Co220 ANNUAL REPORTS OX THE PROGRESS OF CHEMISTRY.These views, written before Sir William Rragg’s work on thearomatic compounds was carried out, are thus remarkably verifiedby the results of this important research.It may also be recalledthat in the Report for 1014 written by Mr. T. V. Barker (page 247)it was very truly observed that to deny the existence of the chemicalmolecule in the solid crystalline state would open up most extensivepossibilities of isomeric change, optical inversions, and so forth.whenever the crystal structure is broken down by dissolving thesolid in a solvent or by subjecting it to fusion. That such changeshave never been observed is a strong argument in support of theview of the persistence of the molecule throughout.The writer was much impressed with the prevalence of mis-conception on this subject when listening to the discussion whichfollowed Dr.Irving Langmuir’s address a t the Edinburgh meetingof the British Association in September last (1921). Several speakersreferred to Prof. Arrhenius, the distinguished exponent of electro-lytic dissociation in dilute solution, who was present, as havingnow taken over also crystals under his wing. The miscoiiceptionhas doubtless arisen from the fact that in such a simple case aspotassium chloride the crystal may be regarded as an assemblageof potassium and chlorine ‘‘ ions ” arranged on a cubic lattice, inwhich each ion is surrounded by six ions of the opposite sign, andthat there are no individual molecules recognisable in the crystalstructure, the potassium ion having exactly the same relation tothe six chlorine ions surrounding it, and vice versa.I n such very simple compounds the pooling above referred to isat its maximum, and the lack of any necessity for assuming mole-cular persistence is obvious.The meaning here attached to theword “ ion ” is not, however, that used in electrolytic dissociation.To generalise from such a simple case as potassium chloride is inany case dangerous, and Sir William Bragg now shows that formore complicated compounds such as naphthalene the general-isation is untrue, and that the molecule is not only persistent butremains remarkably intact, not only in the parent substance but(with the substitutions or replacements) in all its derivatives, andthat two or four such intact molecules form the unit cell of thcsyace-lattice, that is, furnish what the writer calls the grosser unitof the crystal structure, that which exhibits all the symmetrycharacters of the crystals.The real meaning of the “ionisation” intended in the case ofsylvine is clearly explained by Prof.W. L. Bragg,* as well as byDr. Langmuir. The atom of potassium, atomic number 19, has anuclear charge of 19 positive units, and is surrounded by 19 negative4 TV. L. Bragg, Phil. Mag., 1920, [vi], 40, 182, 183; A . , 1920, ii, 637CRYSTALLOGRAPHY AND MINERALOGY. 221electrons, of which 18 are arranged as in argon, in three completeshells and one extra electron outside this stable arrangement.Chlorine, atomic number 17, has a nucleus with a charge of 17positive units surrounded by 17 electrons, one less than the numberrequired to form the stable argon arrangement.The combinationof potassium and chlorine is effected by the chlorine atom absorbingthe extra (19th) electron of the potassium atom, to complete astable argon shell system on its own atom. The nuclear chargesremaining 19 and 17, however, but each atom having now 18electrons, the resultant charges are a one-unit positive charge GIIthe potassium atom and a one-unit negative charge on the chlorineatom ; the two atoms, therefore, attract each other electrostaticallyand form the molecule KC1. The nuclei surrounded by their stableargon shells are regarded as univalent kations and anions ofpotassium and chlorine respectively.This is the precise sense inwhich these " ions " in crystal structure are to be understood.It is supposed that the electrostatic force which would otherwisecause the formation of individually recognisable molecules as justdescribed is prevented by some repulsive force between the outershells, which keeps the atoms apart, and causes their arrange-ment in the cubic lattice, so that any one ion is surrounded bysix of the opposite kind.The fact that the greatest stability is attained in the solid crystalwhen this lattice arrangement obtains is not itself, however, a proofof the accuracy of the no-molecule theory, and as molecules arepresent in the supersaturated solution or liquid just before crystal-lisation (when approaching t o form the solid), and certainly whenthe crystal is again taken down by solution or fusion, this no-molecule theory appears tJo the writer superfluous.The naph-thalene results will in any case require its revision.With regard to the repulsive force which counterbalances theelectrostatic attraction (and which has been so insisted on byKossel), and thus keeps the " ions " apart, it is probably due tothe electronic movements assumed by Born and Land& Indeedthe latter, in his latest paper,4a assumes that not only the atomicnucleus, but also the corresponding electrons of all like atoms forma lattice, which oscillates about the stationary nuclear lattice, thusguaranteeing the regular structure of crystals.The further investigation of crystals by means of X-rays duringthe year 1921 has resulted in the extension of the Bragg spectro-metric method to (a) the adaptation of the powder method ofDebye and Scherrer and of Hull to the X-ray spectrometer, ( b ) themore detailed study of the intensity of X-ray reflection of the4a 2.Physik, 1021, 3, 410222 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.different orders a t a given crystal facial plane, and (c) an attemptto locate the exterior electrons of the atom.Application of the Powder Method to the X-ray Spectrometer.With respect to ( a ) it should be made clear that there are twodistinct methods of using the X-rays for crystal investigation.In one, the original method, a single crystal is employed, and theexperience now acquired shows that the relatively large size ofcrystal employed during the early work is by no means essential;the crystal need not weigh more than a few milligrams, and it isactually more convenient that it should be small, for the pencilof reflected rays is then conveniently limited without the needfor slits other than to act as stops.This method is still the bestand most valuable and instructive.The other method, in which crystal powder is employed, is ofgreat value when good, small, isolated crystals are not available.All the spectra from the different planes of atoms effective arethrown together on the same photographic film or plate, andrequire to be disentangled, a process which has been much simplifiedby Sir William Bragg.Instead of using the cylindrical cameraof Debye and Scherrer, a t the axis of which lies the cylindrical tubeor capillary containing the crystal powder, he pastes the powderon a flat surface and places the latter, instead of the crystal, on theX-ray spectrometer. A Muller X-ray bulb is most suitable foruse with this method, actuated by a half-kilowatt transformer.The spectrometer slit is brought close up to the radiator, becomingthereby the source of a very powerful beam of X-rays sufficientlydivergent to cover a relatively large surface of the plate on whichthe powder is spread. The anticathode is preferably of copper, asthe long wave-lengths. of the copper K-series of X-rays give suitableangles of deflection even for the wide spacings that are found inorganic crystals.The method is especially suitable for organiccrystalline substances, many of which can only be obtained invery small, flaky, acicular, skeletal, or otherwise imperfect forms,useless for the single crystal method.The Interpretation of Intensity of X-ray Rejlection.The very difficult question ( b ) of the correct determination andinterpretation of the intensity of X-ray reflection in the Werentorders, from a plane of atoms in a crystal, has been specially inves-tigated by Prof. W. L. Bragg,5 in collaboration with R. W. James6 W. L. Bragg, R. W. James, and C. H. Bosanquot, Phil. Mug., 1921,Lvi], 41, 309; 42, 1; A., ii, 477CRYSTALLOGRAPHY AND MINERALOGY. 223and C. H. Bosanquet. Very purely homogeneous X-rays werefirst obtained, by preliminary reflection, from a crystal of rock-salt,of the rays from an already fairly pure source, such as the 0.584B.U.radiation from a palladium anticathode. A diagram of thearrangement is given in Pig. 7. Such preliminary reflection (fromthe crystal C,) at the correct glancing angle eliminates all otherundesirable 'general radiations, and the intensity of the very pureray thus obtained can be measured with considerable accuracy.When this pure ray of known intensity is allowed to fall on thecrystal under investigation Cz at the proper glancing angle for thatcrystal the reflected beam canbe investigated as to its exactintensity with great confidence.The ray is directed exactly tothe first crystal face C, by theleaden wedge W , round whichthe reflection occurs; and thesecond crystal C2 is rotatedwith uniform velocity, and thetotal amount of radiation re-flected is measured in the usualway.Prom a considerableamount of experimental workon these lines, using rock-saltand a number of other suitablewell-crystallised substances, aformula of a comprehensivecharacter has eventually beenderived, as the expression ofthe reflecting power of a crystalplane. It includes factors dueto the work of Debye andArrangement for Determination ofIntensity of Reflected X-rays.Schemer, Darwin and Compton, and of Sir W. H. Bragg, derivedboth from theoretical considerations and from exact measurements.It is as follows:in which R is the reflecting power of the face (plane of atoms),N is the number of atoms per unit volume, A the wave-length ofthe X-rays, 8 the glancing angle of reflection, p the linear absorptioncoefficient of the X-rays in the crystal substance, e the charge andrn the mass of an electron, c the velocity of light, B a constantdetermined by Sir William Bragg to be 4.12, and P a factor dependin224 ANNUAL REPORTS ON THE PROGRESS OW CHEMlSTRT.on the angle of scattering and the number and arrangement of theelectrons of the diffracting atom.This interesting factor F hasits maximum a t a very small angle of scattering and falls off asthe glancing angle increases, owing to interference between thewave-traim diffracted by separate electrons. By comparing thetheoretical formula with the measurements obtained by experimenti t is possible, since all the other constants are known, to determinethis factor over a range of angles, and thus obtain valuable informa-tion concerning the arrangements of the electrons in and aroundthe atom, and in particular concerning the positions of thosecomposing the outer shell.The results as published in the two papers quoted agree withthe Lewis-Langmuir version of the atomic structure theory.Theexperimental work with sodium chloride, for instance, affordedmeasures of the intensity of reflection of (amplitude of the X-raysdiffracted by) the chlorine and sodium atoms separately over arange of angles from 10" to GO", and also indicated the correctnumber of electrons in the atoms of each element, and that theyare distribut'ed in shells.In a contribution to the discussion onDr. Langmuir's address to the British Association in September(1921), however, Prof. Bragg stated that the distribution indicatedwas one in which the inner shells of electrons were somewhat closerto the nucleus than was expected.Attempt to Locate Exterior Electrons of Atoms.The third new departure ( c ) is of a still more fascinating character,the direct application of the X-ray spectrometric method to thelocation of the outer electrons of the atom, thus even more directlyexperimentally than as described under ( b ) going beyond the crystalstructure to that of the atoms composing it. The work is describedin two papers by Sir William H.Bragg and Mr. H. Pealing.' SirWilliam Bragg, and also Debye, had for some time been considerablyexercised as to the existence or otherwise of a weak second orderspectrum from the tetrahedral planes of the diamond, but at lastSir William has definitely observed it. The fact is of great im-portance as it determines that alternate planes of carbon atoms arenot alike, and that the carbon atom has in itself a tetrahedralarrangement of electrons, and not a sphere with similar propertiesin every direction from the centre, but is tetrahedrally differentlydisposed, as if there were connecting electrons thus arranged betweenthe atoms. This further implies something tetrahedral in the atomitself, for the electrons to fit on to.Sir Wm. H.Bragg, I'roc. Phys. Xoc., 1921, 33, 304.H. Pealing, ibid., 297CRYSTALLOGRAPHY AND MINERALOGY. 225Mr. Pealing studied fluorspar in a similar manner and obtainedanalogous results. It will be remembered that the calcium atomsoccupy the points of a face-centred cube lattice, and the fluorineatoms the centres of the eight cubelets into which the calcium cubemay be divided. As the atomic weight of calcium (40) almostexactly balances the weight of two fluorine atoms (2 x 19 = 38),the first-order spectrum from the cube planes is nearly extinguished.But the third-order, instead of being still more completely neutral-lised, is much more intense, indicating the presence of some weakdiffracting centre about one-third or one-fourth of the way betweencalcium and fluorine planes, and these appear to be singularities a tthe points of junction between the calcium and fluorine atoms,probably connecting electrons.Hence, these experiments clearly point to the existence ofstationary electrons, or a t least of electrons having averagepositions which are not central but have other definite stations.Further, they show that the atoms in the crystal are not packedinto the smallest possible volume, but form a structure in whichrelatively large empty spaces are left.I n the case of the diamondeach atom is surrounded by only four neighbours, whereas therewould be twelve in the close-packed arrangement of similar atoms ;indeed, the structure is so hollow that an additional equal number ofatoms could be accommodated in a given space, the arrangementthen becoming that of the centred cube, in which each atom haseight neighbours.These results are also in agreement with the Lewis-Langmuirversion of the atomic structure theory.For the carbon atom of thediamond is shown to have four special directions or positions ofattachment of one atom to the next, corresponding with its quadri-valency. And as regards fluorspar, the results agree with thesupposition of Langmuir, on the same principle as already explainedfor sylvine, that a calcium atom of atomic number 20 has twoextra (valency) electrons above the 18 needful to form the stableargon shell of 18 electrons, and will thus combine with two fluorineatoms of atomic number 9, having one electron each less thanrequired to form the stable neon arrangement of 10 electrons, toproduce a compound having the stable shells corresponding toargon and neon around their nuclei.All this recent crystallographic X-ray work is thus so intimatelybound up with the Lewis-Langmuir generalisation that it is essentialthat a brief account should here be given of the relevant portionof Dr.Langmuir’s address to the joint Chemical and PhysicalSections of the British Association a t the late (September 1921)Edinburgh meeting .REP.-VOL. XVIII. 226 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The Lewis-Langmuir Theory as expounded by Dr. Langmuir.The writer, who was present on the occasion, gathered thatthere are three main assumptions. The first is that the electrons inatoms surround the nucleus in successive layers, shells, or sheathscontaining 2, 8, 8, 18, 18, and 32 electrons respectively, their ratiobeing as 12: 22: 22: 32: 32: 42.The second is that atoms maybe coupled together by one or more " duplets," or pairs of electrons,held in common by the completed sheaths of the atoms. The thirdis that the residual charge on each atom and on each group of atomstends to a minimum.Experimental evidence was given by Dr. Langmuir? such as thatderived from vapour-density determinations of the liquid carbonyls,that the number of electrons in the various shells is as given aboveand not that assumed in the Bohr-Sommerfeld version (2, 8, 18, 32,18, 8). It was also pointed out that the sharing of a duplet (pair)of eleotrons by two atoms corresponded to what has become knownas co-valency, and that this kind of bond is that met with, forinstance, in the organic compounds; and that the bonds chieflymet with in inorganic compounds are those of electro-valency,supposed to be due to an electron or electrons passing from thesheath of one atom to that of another.The first type indeed(which shares electrons) usually occurs between two electro-negativeelements, and the second type between an electro-positive and anelectro-negative element. A chemical combination is representedin general form by Dr. Langmuir by the equation%, + zw, = 0 ,where we is electro-valence and v, is co-valence : also we = e - s,where e is the kernel (nuclear) charge and s is the number of electronsin the complete sheath, 8, 18, or 32.Dr.E. K. Rideal pointed out that the very opposite assumptionsof a static character in the Langmuir atom, and of a dynamiccharacter in the Bohr atom, may be reconciled by regarding theatoms as static except during the actual emission or absorption ofenergy, oscillation of the electrons under these conditions being moreprobable than rotation. Indeed there is a general feeling prevalentthat eventually the Lewis-Langmuir and Bohr-Sommerfeld versionsof the atomic structure theory will be brought together, and giveus between them a fuller expression of the truth. The history ofscience is rich in such cases. It would even appear as if animportant step in this direction has been taken by Sir J.J. Thomsonin his latest paper (Phil. Mug., 1921, [iv], 41, 510), in which heshows that his results agree with the law of atomic diameters oCRYSTALLOGRAPHY AND MINERALOGY. 227W. L. Bragg, and with Langmuir’s version so far as the characterand number of electrons in the outer shells are concerned. But nosharing of electrons is assumed, molecules being supposed to beformed by the outer electrons simply acting as couplings, eachvalency bond requiring two electrons, one belonging to each atom,and a double bond being formed by four electrons arranged at thecorners of a square at right angles to the line joining the atomiccentres. These views appear to offer a good explanation of thebenzene ring, and are favourably received by many organic chemists.Prof.A. 0. Rankine adduced some interesting facts in supportof Dr. Langmuir’s assumptions, from his experimental determina-tions of the viscosity of gases. In the first place his results lead to adiameter of the chlorine molecule which is practically identical, asit should be according to the Langmuir version, with the addeddiameters of two argon atoms, the outer shells of which are incontact ; also to similar results with respect to bromine and krypton,and with regard to iodine and xenon. In the second place, a re-markable additional significance was pointed out, of the fact dis-covered by the present writer during the course of his crystallo-graphic investigation of isomorphous series (sulphates, selenates,and double salts), namely, that analogous ammonium and rubidiumsalts are practically isostructural, their molecular volumes and thedimensions of their space-lattice unit cells being almost exactlythe same.Rankine assumes, therefore, from this fact that rubidiumand ammonium possess equal molecular volumes, and that if theLangmuir version be correct krypton should bear the same relationto rubidium as methane, CH,, bears to ammonium, NH,, and an atomof krypton should have the same volume as a molecule of methane.Actual determinations by Rankine of the volumes of krypton andmethane by the viscosity method agree with this precisely.It is of more than merely passing interest that this fact of theisostructure of the rubidium and ammonium compounds shouldprove of such use.The fact has been verified over and over againduring the course of the writer’s work, no less than eighteen caseshaving been studied; and it is confirmed once more in the finalinstalment, on the manganese and cadmium groups, of the researchon the double selenates, which the writer has just completed, so thatno exceptions for the oxy-salts (sulphates, selenates, double-sulphates, -selenates and -chromates) are now possible. It wasfully substantiated by the absolute measurements made with thewriter’s crystals in Sir William Bragg’s laboratory by Prof. A. Oggand Mr. P. L. Hopwood of the space-lattice cells of ammonium and* A. Ogg and F. L. Hopwood, Phil. Mag., 1916, [vi], 32, 518; A., 1916,ii, 594.1 228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.rubidium sulphates.It was this same fact which afforded con-clusive evidence of the fallacy of the valency volume theory ofSir William Pope and Mr. W. Barlow ; for if that theory were correctthe volume of the ammonium sulphate cell should be twice that ofthe unit space-lattice cell of rubidium sulphate. The law of atomicdiameters of Prof. W. L. Bragg, which affords the true sizes of theatoms, and is so fully confirmed by the work of Rankine, now re-places the theory of Pope and Barlow, and with this law the writer’sresults for isomorphous series are in complete agreement.Bragg’s Law of Atomic Diameters.This law, which had only just been announced by Prof. W. L.Bragg9 when last year’s Report was written, and could be onlyFIG.8.RAmmk NumAers of the Dements.The Curve of Atomic Diameters.briefly and incompletely referred to, has received further experi-mental support during 1921. A careful scrutiny of all the absolutemeasurements of atomic-plane spacing and atomic distances incrystal structures, carried out up to the present by means of X-rays,has confirmed the first assumption that the atoms of each element,when regarded as spheres, possess the same diameter in all thecystallised compounds into which they enter, and that these constantatomic spherical dimensions are related, not as the valencies of theelements (the Pope and Barlow hypothesis), but in the mannergraphically exhibited by the periodic curve reproduced from Prof.Bragg’s memoir in Fig.8. When the crystal is that of a chemicalelement the distance between the centres is actually the diameterof the sphere itself, the sum of the radii of the two equal spheres incontact; and when it is that of a chemical compound the distance9 W. L. Bragg, Phil. Mag., 1920, [vi], 40, 169; A . , 1920, ii, 537CRYSTALLOGRAPHY AND MINERALOGY. 229separating the centres of two adjacent atoms of different elementsis the sum of the two radii of the spheres, now different.In all cases, in fact, the distance between the centres of con-tiguous atoms, whether of the same or different elements, is equalin absolute measure to the sum of the two atomic radii. Thesedistances, moreover, correspond with the observed closest positionsof the two elementary atoms, nearer than which they never approach,the limiting surface of each being apparently that of the outer shellof electrons, or at any rate that of a sphere of impenetrability, theatomic domain.A table of the actual values is next given, asderived from direct X-ray measurement with crystals, and it alsoincludes the diameters of the atomic spheres of neon, argon, krypton,and xenon, derived from indirect determinations of the outer shellsof electrons.Atomicnumber.34678910111213141617181920222425ATOMIC DIAMETERS, IN ~NGSTROM UNITS.A. = lo-* cm.Atomic3 Atomic AtomicElement. diameter. number. Element. diameter.Lithium .........Glucinum ......Carbon .........Nitrogen ......Oxygen .........Fluorine .........Neon ............Sodium .........Magnesium ...Aluminium ...Silicon .........Sulphur .........Chlorine .........Argon ............Potassium ......Calcium .........Titanium ......Chromium ......3.002-301-541.301.301.351-303.552.852-702.352-052.102.054.153.402.802.80262728293033343536373847485051525354Iron ............Cobalt .........Nickel ............Copper............zinc ............Arsenic .........Selenium ......Bromine .........Krypton .........Rubidium ......Strontium ......Silver ............Cadmium ......Tin ...............Antimony ......Tellurium ......Iodine ............Xenon .........(elec tro- 55 Csesium .........Manganese ...... 2.95 81 Thallium ......9 9 {negative)} 2-35 56 Barium .........(electro- 82 Lead ............ 3-80” ( n e g a t i ~ e ) ) ~ . ~ ‘ 83 Bismuth ......... 2.962.802-752.702-752.652.522.352.382.354.503-903.553-202.802.802.652.802-704-754.204-50In making these comparisons from all the published material,and with the aid of new determinations of atomic diameters byProf. Bragg himself, of which the results are expressed in the table,it has been clearly recognised that there are two very distinct typesof structure in crystals, namely, (1) those in which the relativepositions of all the atoms are fixed by the symmetry, and (2) thosein which, while some atomic positions are fixed, those of other atomsare not but, within certain limits (usually along a line) which aredependent on the symmetry, are permitted some latitude of arrange230 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ment, the exact positions being determinable by the X-ray measure-ments. The chlorides of sodium and potassium, zinc blende, andthe diamond, are obviously of the first type; aAd iron pyrites ofthe second.For while the iron atoms in pyrites are fixed a t thecorners and face-centres of the cube, the sulphur atoms are situatedon alternate diagonals, at a definite position on each of thesediagonals which is not, however, fixed by the symmetry but hasbeen found by X-ray measurement to be a t the distance of 1.025A.U. from an unoccupied corner of the cubelet, eight of whichcubelets form the main cube which has iron atoms a t its cornersand face-centres.Indeed, as there is another sulphur atom onthe continuation of this same diagonal in each case, at the same dis-tance from and on the other side of the unoccupied corner just referredto, the centres of these two sulphur atoms will be a t the distanceapart of 2.05 k U . Further, as sulphur atoms have never beenfound to approach closer than this, 2.05 B.U. is the sum of the tworadii and therefore the atomic diameter of sulphur.The next striking fact brought out by the law of atomic diametersis that the electro-positive alkali metals, lithium, sodium, potassium,rubidium, and czesium stand out with remarkable prominence a tsharp maxima of the curve, which is steep on each side of them;the alkaline earths follow some distance down, whilst the electro-negative elements and those dyad-acting metals which also formweak acidic oxides occupy the minima, which are much less sharp.That the size of the atomic sphere-be i t sphere of influence or theouter spherical shell of electrons-is not a question of valency isquite clear.For the smallest atoms are those of oxygen of valencytwo and nitrogen of valency three or five, each having the atomicdiameter 1.30 A.U., whilst the univalent alkali metals have atomicdomains varying from 3 to 4.75 A.U., cEsium, the most electro-positive element known, having this latter maximum atomicdiameter. The atomic diameters are thus periodic functions ofthe atomic number.They will doubtless prove to be of greatassistance in unravelling the structures of the more complex in-organic compounds,The Law of Atomic Diameters accords well with the Lewis-Langmuir version of the atomic structure theory; for the electro-negative elements which have the minima of atomic domain areprecisely those which share electrons to complete the stable (inertgas) shell, having fewer electrons than correspond to the stablesystem. Indeed, it is apparently this sharing of electrons whichcauses the spheres to have smaller diameters than those of theelectro-positive elements. On the other hand, as an electro-positiveelement does not share electrons in its outer shell with neighbourinFIa. 9.Model of Calcium Carbonate.FIG.10.Dissected Model of Calcium Carbonate.[Toface p . 231. CRYSTALLOGRAPHY AND MINERALOGY. 23 Iatoms, but has its active electron or electrons outside the stableshell, it occupies a greater space in the strubture. Perhaps the mostinstructive case referred to by Prof. Bragg, as affording bothtypes of attachment in the same chemical compound, is that ofcalcite, CaCO,, which is illustrated by models reproduced in Figs. 9and 10, the latter showing the structure taken to pieces. Thecalcium atoms, represented by the large spheres, have each a doublepositive charge, whilst the carbon and oxygen atoms of the CO,group together afford a corresponding double negative charge ; thecarbon and oxygen atoms of this group share electrons and areconsequently knitted closer together (approximately at their atomicradial distance), so their spheres are smaller as shown by the model,the smallest being the oxygen atoms (lightly shaded in the figure).Important confirmatory evidence of the law has been broughtforward by Prof.A. 0. Rankine lo from the measurements of theviscosity of the four inert gases, and of oxygen, nitrogen, and thethree halogens. He has found that the nearest approach of theatoms of any one of these gaseous or vaporised elements to eachother during a collision is only slightly greater than the atomicdiameter of Bragg. This is exactly what would be expected fromthermally agitated atoms; a cushion or film of resiliency or repul-sion between them (due probably to the electronic movements ofBorn and LandB) prevents absolute contact of the outer electronicshells on collision, otherwise attachment would occur.Prof. 'W. L.Bragg has pointed out, moveover, that both the viscosity and thecrystal structure results point to the same increase in the size ofthe atom as each successive electron shell is added, there being adefinite increase in the dimensions of the outer electron shell inpassing from one period to the next.The Law of Progressive Crystal Structure in Isomorphous Seriescontaining the Alkali Metals.The remarkable outstanding size of the atoms of the alkali metals,as so clearly shown by their sharp maxima in the curve of atomicdiameters, and also the considerable progressive increase in thedimensions of their shells as we pass from one to another (belongingto successive periods), explain and render still more important thetwo most prominent facts emanating from the writer's researcheson the crystal-characters of the isomorphous sulphate, selenateS Sand double salt series RzSeO, and RzM(Se04),,6Hz0, in which Rrepresents either potassium, rubidium, or caesium.The first factis that in the double salt series these alkali metals exert a vastlyLQ A. 0. Bankine, Phil, Mug., 1920, [vi], 40, 518; A., 1920, ii, 679232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.predominating influence in determining the properties of the crystals,their interchange causing a very definite change in the crystalangles and constants ; whereas interchange of the dyad-acting Mmetals, which are near and almost on the minima of the curve ofatomic diameters, has but a slight determinative effect on theangles, volume constants, and physical properties of the crystals.The second fact is that the specially marked changes due to inter-change of the alkali metals, whether in the double salt series or inthe alkali sulphates or selenates themselves, are definitely progres-sive, following the progression of the atomic numbers of the threealkali metals.Thus not only does the relatively very large size ofthe atoms of the three alkali metals (the caesium atom being, asalready mentioned, the largest of all atoms), and the consequentrelative magnitude of the progressive difference in their sizes, causethe changes of crystallographic constants, both structural andphysical, to be prominently marked, but it gives, in doing so, themaximum opportunity possible for any progressive character toreveal itself in these changes, corresponding to the addition of anotherelectronic shell when we pass from potassium to rubidium andfrom the latter to czsium.Hence, the choice of the salts of thesemetals-both the simple rhombic sulphates and selenates andthe monoclinic hexahydrated double sulphates and double selenates-has proved a singularly suitable and fortunate one, and the Lawof Progression of the Crystallographic Properties with Rise of AtomicNumber of the Alkali Metals has been placed on the firmest possiblebasis.Thus the Law of Atomic Diameters, together with the funda-mental Law of Moseley-according to which the atomic numberexpresses the mass and positive charge on the atomic nucleus andalso the number of the surrounding negative electrons-explainscompletely the results of the writer’s investigations, which may bejustly regarded as the natural consequence of these laws.Con-versely also, Prof. Bragg may fairly consider that the writer’sresults support his law of atomic diameters.It may perhaps be permitted to be stated in this Report, as thepresent moment marks the conclusion of a research which hasoccupied full thirty years, that the writer has now just completedthe work on the last two groups of salts, the double selenates ofthe manganese and cadmium groups. Altogether seventy-five saltshave been investigated, including also those in which R is ammoniumand thallium, and also including a group of isomorphous doublechromates, in investigating which the writer had the collaborationof Miss Mary W.Porter. The specially careful preparation ofnumerous crops of each of these seventy-five salts, the goniometrCRYSTALLOGRAPHY AND MTNERALOGY. 233of ten or more of the most perfect crystals of each of them, and the'determination of their density (more than eight hundred crystalshaving been completely measured and five hundred density deter-minations carried out), the preparation of more than two thousandtruly plane and correctly orientated surfaces with the veryefficient aid of the cutting-and-grinding goniometer, in order toprovide at least eight section-plates and six 60O-prisms of eachsubstance, has alone been a formidable task, and fully explainsthe time over which the work has inevitably extended.It was feltto be essential to include every salt of these series which could beobtained in good crystals, and it is satisfactory to be able now toreport that the conclusions are contributed unanimously, withoutany exception, by all the groups studied, which are nineteen innumber. The crystal angles, the habits of the crystals, the volumesand edge-dimensions of the unit cells of the space-lattices, the dimen-sions and orientations of the optical ellipsoids, the molecular refrac-tion constants, the thermal dilatations in all cases where it waspossible to determine them, indeed the minutest details of thephysical properties studied, have throughout exhibited the pro-gression according to the atomic numbers of the three alkali metals(K = 19, Rb = 37, Cs = 55, a difference of eighteen at each step,corresponding to a whole Langmuir shell of electrons), the crystalsof the rubidium salt invariably proving intermediate.The import-ance of the isostructure of the rubidium and ammonium salts,so clearly in all cases also revealed, has already been adequatelyreferred to. I n practically every property but refractive power,in which it is transcendently high, the thallium salt also stands closeto the rubidium salt. It has been made very clear, moreover, thatonly the potassium, rubidium, and caesium salts are " eutropic "(following the law of progression with atomic number of alkalimetal), the ammonium and thallium salts being only generallyisomorphous. The largest amount of change of angle for any replace-ment of one R-base by another has proved to be 2" 28' (betweenpotassium copper and czsium copper selenates) .In two papers published during the year by Prof.P. Niggli ofZurich,ll the editor of the now resuscitated Zeitschrift fiir Kristal-lographie, the connexion between crystal and atomic structure isdiscussed, and reference especially made to the writer's work. Hepoints out that the homogeneity of crystal structure is not due tothe arrangement of mere mass particles, but to the symmetry orstructure of those particles themselves, the elementary atoms,and to the fields of force, orientated in character, which in con-sequence may be regarded as emanating from the atoms.He goesl1 P. Niggli, 2. Kryst. Min., 1921, 56, 12, 167; A., 1922, ii, 36.I234 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.further in stating that from crystal structure that of the atomsbuilding up the crystal ought to be elucidated. He turns largelyto the determination of density in isomorphous series as an indica-tion of the ranges, spheres of influence, or volumes of the atoms ofthe elements which by their mutual arrangement replace each other,and quotes the writer’s determinations of the densities of themonoclinic hexahydrated series as typical and adequately accuratefor his purpose, and as clearly proving the progressive growth ofthe sphere of influence of the atoms of the alkali metals as theatomic number increases.Niggli then analyses a considerableamount of the material in vols. I and I1 of Groth’s “ChemischeKrystallographie, ” with similar results, making allowances for lessaccurate experimental data, and finally arrives at relative volumesfor the spheres of action of the atoms of many elements, and it ishighly interesting that the corresponding relative diameters showthe same regularities of periodicity as the atomic diameters inabsolute measure of W. L. Bragg. This conclusion, moreover, wasarrived a t before the publication of Bragg’s paper, so that it isdoubly valuable as being an independent arrival a t the Law ofAtomic Diameters, largely from the work of the writer aided as faras possible by older measurements in other series, and especiallyconfirmed as regards the morphological and volume constants bythe excellent work of W.Muthmann on the permanganates and ofT. V. Barker on the perchlorates of the alkalis.In concluding this section of the Report, therefore, it may bepointed out how very satisfactorily the results of the investigationsof so many different workers support, confirm, and amplify oneanother, so that we may now be sure that knowledge of real valueand permanence has been arrived a t during the year that has justclosed.Miscellaneous X-ray Results.The Structure of Adularia and Moonstone.-The results of a usefulinvestigation commenced a t Cambridge by Mi. S. KOZU, concerningthe structure of adularia and moonstone, and continued in Japanin collaboration with Y.Endo and M. Suzuki, are published in anew journal, Science Reports of the Tohoku Imperial University,Xendai, Japan (1921, Vol. I, No. 1, p. 1). Adularia and moonstoneare supposed to be solid solutions of varying proportions of ortho-clase, albite, and anorthite felspars, moonstone being the variety ofadularia which exhibits “ schillerisation ” (the display of a pearly,sub-metallic, or bronze-like lustre). The results indicate thatadularia consists of a single space-lattice structure, a homogeneoussolid solution, whilst moonstone has two different space-lattices oCRYSTALLOGRAPHY AND MINERALOGY. 235like type, affording a double Laue radiogram, the two differentsubstances being two kinds of solid solutions, both of monoclinicsymmetry. On heating moonstone the two space-lattices approacheach other and eventually become identical a t 1060", the latticethen being that of adularia.At about 1000" the schillerisation dis-appears. Hence this work has proved that schillerisation is notdue to cavities and inclusions, as supposed, but to interference ofordinary light rays by the presence of two space-lattices alike insymmetry but quite distinct.The Structure of '' Liquid Crystals " has been studied by J. S. vander Lingen l2 by the Laue method of X-ray analysis, with the viewof definitely testing whether these remarkable substances, so inti-mately associated with the name of Prof. Lehmann, are in realityendowed with a space-lattice structure, the criterion of a truecrystal, as asserted by Vorlander, or are merely swarms of similarlyorientated molecules, as supposed by Bose.p - Azoxyanisole,p-azoxyphenetole, anisaldazine, and active amyl cyanobenzylidene-aminocinnamate were produced in the so-called " liquid crystal "form in a strong magnetic field, and Laue X-radiograms taken ofthem. The result was definitely negative, no sign of a space-latticebeing revealed. The regularity of structure producing doublerefraction and other optical effects simulative of crystals appearsto be due merely to the similar orientation (parallelwise) of the flatelongated molecules themselves, the swarm theory of Bose beingthus verified.In a second memoir van der Linden l3 describes further experi-ments with the anisotropic liquid (the liquid crystal) form ofp-azoxyanisole, in which a pattern of faint horizontal lines wasobtained, apparently due to diffraction from parallel layers oflamellar molecules, a direct confirmation, it would seem, of Bose'sswarms.In the writer's opinion Prof. Lehmann is to be congratu-lated on this result, although it is not in conformity with his earlierviews. For his " liquid crystals " thus become an intermediate stage,of deeper interest than ever, between true liquids and true crystals.The Structure of Alabandite, MnS, has been studied by R. W. G.Wyckoff.14 The crystals belong to the hexakis tetrahedral class 31of the cubic system, and X-ray analysis shows them to be con-structed like rock-salt,, but with some slight lack of symmetry inthe lines of force about the atoms.It is thus different from zincblende, ZnS. Magnesium oxide, MgO, afforded almost identicalresults, the sodium chloride structure being closely simulated.l2 J. S. van der Lingen, J. Franklin Inst., 1921, 191, 651 ; A., ii, 438.l3 LOC. cit., 192, 511; A., ii, 681.l4 R. W. G. Wyckoff, Amer. J. Sci., 1921, [v], 1,138; 2, 239; A., ii, 262, 700.I* 236 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The Structure of the Ammonium Haloids has been investigatedby Dr. Langmuir and G. Bartlett 15 at different temperatures. Thehigh-temperature form of each proves to be constructed like sodiumchloride, each atom being surrounded by six others.The ordinary-temperature forms of the chloride and bromide possess a centredcube structure, each atom having eight others around it. It is con-sidered that the ammonium “ ion ” has tetrahedral symmetry,while the alkali metals and halogens have cubic “ ions.”Colloidal Substances.-An interesting X-ray investigation of so-called colloids has been carried out by Scherrer.16 Colloidal gold,the finest precipitated gold (that in the remarkable purple liquidwhich never deposits), was found to consist of minute crystalparticles having the same face-centred cube structure as ordinarygold crystals, some of the particles being only 1-86 x 10-7 cm. indiameter, so that only five cube-lattice edge-lengths were containedin each particle. Colloidal silver also proved to be crystalline,with a face-centred cube lattice.Silica likewise proved to becrystalline, and the only true colloid among the substancesexamined was gelatin, which showed no sign of crystal structure.Metallic Elements.-A. W. Hull 17 has given a list during the yearof further metallic elements investigated by him as regards theircrystal structure by his powder method. The list is as follows, thedimensions of the cube edges or trigonal prism edges, and the axialratio a : c of the hexagonal metals, being also given.Face-centred Cube Lattices.Calcium ..................... 6.56 A.U.a-Cobalt .................. 3-554 ,,Nickel ..................... 3- 540 , ,Rhodium .................. 3.820 ,,Palladium ............... 3.950 ,,Iridium ..................3-805 ,,Platinum .................. 3.930 ..Centred Cube Lattices.Chromium .................. 2-895 8.U.Molybdenum ............... 3.143 ,,Tantalum .................. 3 . 2 7 2 . ,Hexagonal Close-packed Lattices.a : c&Cobalt ......... 2.514 A.U. 1 : 1.63Cadmium ......... 2.960 ,, 1 : 1.89Ruthenium ...... 2.686 ,, 1 : 1.59Zinc ............... 2.670 ), 1 : 1.86The Structure of l c e has been studied by D. M. Dennison,18 byproducing a shower of minute crystals in a water-filled capillarytube, plunging it into liquid air, and using the Hull method. Theresults indicate the close-packed hexagonal lattice, consistin oftwo sets of interpenetrating triangular prisms, with edges 4-52 1.U.and height 7-32 A.U.The axial ratio found was a : c = 1 : 1-62,A., ii, 261.l6 G. Bartlett and Irving Langmuir, J . Amer. Chern. SOC., 1921, 43, 84;l6 P. Scherrer, Zsigmondy’s “ Kolloidchemie,” 3rd ed., p. 387.l 8 0. M. Dennison, ibid., 1921, 16, 20.A. W. Hull, Physical Rev., 1921, 17, 42, 571CRYSTALLOGRAPHY AND MINERALOGY. 237very near the theoretical 1.633 for a close-packed hexagonal arrange-ment of spheres. It may be remembered that Rinne found ice tobe hexagonal bipyramidal, class 25 (that of apatite), with an axialratio 1 : 1.678.The Structure of the Xilver Haloids has been determined by R. B.Wilsey,IQ in the laboratory of the Eastman Kodak Company,Rochester, N.Y., also by the powder method. The precipitatesobtained by adding potassium chloride, bromide, or iodide solutionto a solution of silver nitrate were employed, and the results provethe crystalline character of these precipitated silver salts.Alsopowdered fused silver bromide was used, with identical results. Thechloride and bromide are constructed of simple cube lattices of theside dimensions 2.78 and 2.89 A.U. respectively, one atom beingassociated with each point of the lattice. Silver iodide, however,gave results which corresponded with the diamond lattice, each sideof the cube being 6.53 A.U., one atom being ascribed to each pointof the structure; each iodine atom appears to be a t the centre of atetrahedron the corners of which are occupied by four silver atoms,and each silver atom is surrounded by four iodine atoms in thesame manner, the distance of the.atomic centres being 2-83 A.U.The silver bromide and chloride precipitated in photographicemulsions form minute distinct cubic crystals ; the iodide similarlyproduced in these emulsions appears to be hexagonal.These formshad not been studied, but a promise of such an investigation byX-rays is given. The result should be interesting, as silver iodidecrystallises at the ordinary temperature in the dihexagonal pyra-midal class 26 of the hexagonal system, and becomes converted onbeating to 146" into a cubic form.The Crystal-structure of Antimony and Bismuth.-Prof. A. Ogg 2ohas confirmed the conclusion of James and Tunstall that the unitrhomb of each of these metals contains eight atoms. The edge ofthe unit rhomb of antimony is 6-20 A.U., the structure consistingof two interpenetrating face-centred rhombohedra1 lattices, andthe shortest distance between the atoms is 2.92 A.U.James andTunstall made it 2-87 A.U. The length of the edge of the unitrhomb of bismuth was found to be 6.52 A.U. R. W. JamesFlin a further paper, gives it as 3-28 A.U., the half of the value justquoted, and for the closest approach of two atomic centres 3.11 A.U.The Structure of Potassium Cyanide Crystals has been determinedby P. A. Cooper 22 with small single crystals, and found to resemblethat of potassium bromide, the CN acting as a whole like Br. ButR. B. Wilsey, Phil. Mag., 1921, [vi], 42, 262; A., ii, 548.2o A. Ogg, ibid., 163; A., ii, 513.22 P. A. Cooper, Nature, 1921, 107, 746.21 R.W. James, {bid., 193; A., ii, 513238 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.no definite evidence was obtained as to the disposition of the atomsof carbon and nitrogen.The Diamond.Three papers of general interest concerning the diamond haveappeared during the year 1921. One embodies a communicationto the Mineralogical Society by Dr. J. R. S ~ t t o n , ~ ~ Director ofthe Kimberley Observatory, S. Africa, who showed that diamondcrystallises readily on garnet, iron pyrites, olivine, and ilmenite(FeTiO,) . These minerals are frequent inclusions in diamond, asare also graphite, bort, and diamond itself of unconformableorientation. So common are diamond inclusions (either fragmentsor complete crystals) in the diamonds found a t Bullfontein thatthey impart a specific reputation to these " stones," for whitespots, cross-grain, and " knots.'' It is these various inclusionswhich set up strain, and even fracture, in the enclosing diamond,and most diamonds found broken owe their rupture to this cause.Dr.Sutton entirely discredits the stories of bursting and explodingnatural diamonds, and in a long experience has never known anauthentic case. Such strain as there is in a diamond, revealed inthe dark field of the polariscope, Dr. Sutton attributes entirely toinclusions, the thermal dilatation of which is different from thatof the diamond. Artificial diamonds, however, do explode fromstrain. The late Sir William Crookes in his fascinating book" Diamonds '' (page 120) describes how such an artificial diamondexploded on a microscope slide in his laboratory during the night,the diamond having been produced under great pressure.A second paper by F.Fischer 24 deals with the artificial prepara-tion of diamonds, and it is shown that under other than abnormallyhigh pressures the separation of carbon as diamond (a non-conductor of electricity) can only occur below 700°, and that other-wise it appears as graphite (a conductor). The small size of thehitherto produced artificial diamonds he attributes to this fact,for a t 700" the iron containing the carbon in solution has alreadysolidified, so that the carbon could separate only in minute crystals.He suggests that larger diamonds would probably be produced ifa substance could be found in which carbon is soluble and which isstill molten at 700".The third paper concerns the compressibility of the diamond,which has been studied by L.H. ad am^,^^ and found to be thelowest on record, namely, 0.16 x per megabar (a megabar =23 J. R. Sutton, Min. Mag., 1921, 19, 208.24 F. Fischer, Brennstoff-Chem., 1921, 2, 9 ; A., ii, 111.25 L. H. Adems, J. Wmhingtm Acad. rSci.? 1921, 11, 45CRYSTALLOGRAPHY AND MINERALOGY. 2390.987 atmosphere), within the range of pressure from 4,000 to 10,000megabars. The difference from graphite is immense, the valuefor graphite having been shown by Prof. T. W. Richards to be3 x Thus we have onemore property added to those for which the diamond holds therecord.and that of steel to be 0.6 xConcluding Remarks.This Report has already reached the allotted span, arld a numberof other valuable contributions to the work of the year 1921 canonly be mentioned. Dr.H. H. Thomas and Mr. A. F. Hallimond26have devised a useful direct-vision refractometer for liquids, whichalso serves the special purpose of preparing a liquid mixture ofany required definite refractive index, a most desirable object inmodern optical crystallography. Miss Mary W. Porter 27 hasextended the research mentioned in the last Report, which shecarried out in collaboration with Mr. T. V. Barker, by describingcrystallographically a number of pyridine and picoline derivativeswhich might have been expected to show some morphotropicregularities. But organic radicle replacements prove to causevery great (indeed often entire) change of crystalline form,indicating how very sensitive crystal structure is to change ofchemioal composition.Dr. Harold Hilton 28 has contributed two papers of mathematicaland geometrical interest, one regarding the determination of opticaxes from extinction angles, and the other concerning the vibrationsof a crystalline medium.Both subjects are treated in a masterlymanner, and the latter paper gives food for much thought, at atime when atomic structure is proving to be a t the root of molecularmovements and the building up of a crystal edifice. A newmineral, a basic copper phosphate, of peacock-blue colour byreflected light and greenish-blue by transmitted light, is describedby Dr.A. Hutchinson (to whom hearty congratulations are due onhis election as the new President of the Mineralogical Society)and Mr. A. M. Ma~gregor.~~ It proves to have the composition~CU,(PO,)~,~CU(OH),, and was discovered in Northern Rhodesia.The earlier onedeals with a substance which was described in the year 1879 byC. 0. Trechman as an orthorhombic form of metallic tin and termedby him @-tin. It is now shown to be not tin but stannous sulphide,Dr. L. J. Spencer 30 has published two papers.26 H. H. Thomas and A. F. Hallimond, Min. Mag., 1921, 19, 124.2 7 Miss Mary W. Porter, T., 1921, 119, 1769.2 8 H. Hilton, Min. Mag., 1921, 19, 233; Phil. Mag., 1921, [vi], 42, 148.29 A. Hutchinson and A. M. Macgregor, Min. Mag., 1921,19, 225; A., ii, 701.30 L.J. Spencer, ibid., 113, 263; A., ii, 266240 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the orthorhombic crystals of which are often produced in tin smelting.Tin is thus not trimorphous, but only dimorphous, ordinarywhite tin being tetragonal, and “ grey tin ” (tin pest) cubic. Thesecond memoir is a fascinating essay, with numerous beautifulillustrations, on curvature in crystals. Many of the most remark-able examples of curved crystals in the British Museum collectionare described and portrayed. The paper is not only pleasantlyreadable, but forms an admirably concise summary of the typesof crystal distortion and contortion.To Dr. Spencer it is largely due that the new venture of theMineralogical Society, the publication of Mineralogical Abstracts,commenced in March, 1920, has been carried successfully througheight numbers and is now so nearly up to date that nineteen ofthe memoirs published in the past year, 1921, have been dealtwith.The value of these abstracts is now assured, and they aremost heartily welcomed. To the December number of the Minera-logical Magazine Dr. Spencer also contributes a considerable numberof valuable biographical notices, with portraits, of lately deceasedcrystallographers and mineralogists, including Profs. Fedorov, vonLang, and Voigt, together with an index to all such notices whichhave appeared in the Magazine since its inception in 1876.In the March, 1921, number of the Magazine appears an importantReport, of the Committee on British Petrographic Nomenclature,of which Committee, jointly appointed by the Geological andMineralogical Societies, Prof. W.W. Watts was chairman andLt .-Col. Campbell Smith was secretary. The recommendationswill do much to bring order into the somewhat chaotic state ofthis nomenclature.During the year 1921 the Mineralogical Society has lost one whowas universally regarded as the “ father ” of the society, its presi-dent during the years 1885 to 1888 and its general secretary forthe succeeding twenty-one years, Sir Lazarus Fletcher. His nameis happily perpetuated in the “ Fletcher Indicatrix,” the ellipsoidnow so conveniently used to express the optical properties ofcrystals. An admirable biographical notice by Sir Henry Miers,with portrait, appears in the June (1921) number of the Mineru-logical Magazine, and in this same number, by a singular chance,is published also Sir Lazarus Fletcher’s last paper, a memoir writtenwith all his accustomed thoroughness, on “The Crumlin (Co.Antrim) Meteorite.”During the meeting of Science Masters a t Oxford in January,1921, some interesting demonstrations were given by Mr. T. V.Barker at the Mineralogical Department of the University, on“ The Study of Crystals in Schools,” and a very useful pamphleCRYSTALLOGRAPHY AND MINERALOGY. 241of “ Practical Suggestions ” for this study has been published bythe Holywell Press.During the year 1921 three important books have appeared.Of two bearing the same title, “ Lehrbuch der Mineralogie,” oneis a new book by Prof. P. Niggli31 of Zurich, already referred toas the new editor of the resuscitated Zeitschrift fiir Kristallographieand the other, edited by Prof. F. Becke 32 of Vienna, is the 8thedition of the text-book of Prof. Gustav Tschermak. The third isa new book by Prof. P. von Groth,33 an attempt to combine inabbreviated form the characters of his well-known “ PhysikalischeKrystallographie ” and of his large (5-volume) “ ChemischeKrystallographie . ’ ’By the time this Report appears it is probable that a second andvery much enlarged edition of the writer’s “ Crystallography andPractical Crystal Measurement ” will have been published. Theimmense amount of research, including the whole of the X-raywork, carried out since the appearance of the fist edition in 1911,and the desirability of acceding to the many expressed wishes thatthe book should be made more fully to cover the whole subject,have caused it to be extended to two volumes.It will be evident to all who read this Report how very con-siderably the crystallographic investigations of the past yearso large a proportion of which are British, have contributed tothe very basis of Chemistry, the unravelling of the nature of thechemical atom. There is no longer any necessity for a crystal-lographer to plead for more attention to his subject, its value isnow most clearly evident to all. The realm of Organic Chemistryis now also entered, and indeed no one can say how far the newmethods of attack by X-rays will take us, the possibilities beingimmense. Perhaps, however, the most encouraging fact is thatall this recent research has permanently confirmed the principleson which crystallographers of late years have built up their science.For, as the writer states in the preface to the new edition of hisbook, “ not one single conclusion or principle, presented in thefirst edition, has been shown to be invalid or incorrect.”A. E. H. TUTTON.31 P. Niggli, “ Lehrbuch der Mineralogie,” 1920, Gebriider Borntraeger,32 G. Tschermak and F. Becke, ibid., 8th edition, 1921, A. Holder, Vienna33 P. Groth, “ Elemente der phys. und chem. Krystallographie,” 1921,Berlin.and Leipzig.R. Oldenbourg, Munich and Berlin

ISSN:0365-6217    

DOI:10.1039/AR9211800210

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

INDEX OPAanensen, D., 163.Abernethy, C. L., 14.Abt, A. F., 173.Adam, N. K., 5.Adams, E. P., 12.Adams, E. Q., 139.Adams, I,. H., 238.Adriano, F. T., 154.Ahlberg, R., 119.Allpress, C. F., 106.Alsberg, C. L., 152.Alstine, E. van, 157.Amberger, C., 58.Andersson, H., 28.AndG, K., 157.Andre, E., 154.Andress, K., 149.Angeletti, A., 161.Annett, H. E., 207.Anschutz, L., 111.Anschutz, R., 84.Anselm, F., 11 8.Arakatsu, B., 25.Arkel, A. E. van, 25.Armstrong, E. F., 22, 69.Arnold, R., 151.Arnold, V., 181.Aronowsky, A., 170.Arrhenius, O., 150.Artmann, P., 156.Asahina, Y., 142.Aschan, O., 91, 99.Aston, F. W., 33.Atack, F. W., 88, 89.Atkinson, H., 162.Audubert, R., 7, 11.Auwers, K. von, 108, 111, 112,121.AUTHORS' NAMES~~~114,Badische Anilin- & Soda-Fabrik, 115,Baker, J.L., 154.Baldwin, E. J., 17.Baly, E. C. C., 12, 13, 203.Barker, W. F., 12, 13, 203.Barlot, 47.Barnes, S. K., 161.137.' 1Barnett, E. de B., 103.Bartels, R., 1.Bartholomaus, E., 124.Bartlett,, G., 236.Bassett, H., 55.Battegay, M., 103.Baumann, E., 125.Baur, E., 18.Baxter, G. P., 37, 38.Beans, H. T., 18.Beardwood, J. P., 160.Bechhold, H., 26.Beck, F., 74.Becke, F., 241.Beckendorf, A., 120.Becker, O., 93.Beckerath, K. von, 26.Beckley, V. A., 194.Bell, H., 5.Benary, E., 115.Bergmann, M., 65, 74.Berl, E., 149.Bertrand, G., 205.Besthorn, E., 137.Beth, W., 136.Bezssonoff, N., 153, 201.Bhatnagar, S. S., 7.Biedermann, W., 174.Biilmann, E., 159.Billy, M., 49.Biltz, H., 121, 122, 132,Binder, 0.H., 14.Birckenbach, L., 37.Bishop, E., 26.Blackman, F. F., 203.Blair, A. W., 196, 202.Blanck, E., 195.Boeseken, J., 86.Bohme, O., 129, 135.Boehmer, H. C., 159.Boeree, A. R., 21.Borjeson, G., 25.Bottger, W., 163.Bohn, R., 131.Bohnson, V. L., 19.Bolliger, A., 11 6.Bommer, M., 143.Bone, W. A., 24.3133, 134244 INDEX OF AUTHORS’ NAMES.Booth, H., 43.Born, M., 17.Bornemann, F., 209.Borsche, W., 99, 109, 116, 126, 128.Bosanquet, C. H., 222.Boullanger, E., 201.Boutaric, A., 26.BOU~OUCOS, G., 200.Bowen, E. J., 22.Braanaas, A., 20.Bragg, (Sir) W. H., 210, 224.Bragg, W. L., 5, 220, 222, 228.Braley, S. A., 160.Branch, G. E. K., 126.Braun, J.von, 79, 101, 107.Brauns, F., 63.Braunsdorf, O., 107.Breazeale, J. F., 193.Bridel, M., 151.Briggs, L. J., 193.Brinckley, S. R., 51.Brioux, C., 197.Britton, H. T. S., 161.Br@nsted, J. N., 35.Broughall, L. St. C., 5.Browning, P. E., 161.Bruylants, P., 38.Buchler, C. C., 79.Buckner, G. D., 206.Budkewicz, E. von, 81.Bullis, D. E., 197, 205.Burgess, H., 127.Burns, J. W., 161.Burns, R. M., 23.Burton, E. F., 26.Butler, O., 204.Byk, A., 10.Cady, H. P., 17.Cain, J. C., 87.Campbell, C., 2.Carrero, J. O., 197, 205.Carver, E. C., 7.Casale, L., 194.Cassel, H., 15.Cerighelli, R., 205.Cernatesco, R., 28.Cessna, R., 185.Chadwick, J., 31.Challenger, F., 106.Chambers, V. J., 81.Chapin, H. C., 38.Chapman, D.L., 15.Chatterji, N. G., 158.Chsvanne, G., 147.Chemische Fabrik Griesheim-Elek-Cheng, Y. C., 6.Chibnall, A. C., 207.Chretien, E., 165.Christiansen, W. G., 189.Ciamician, G., 119, 207.tron, 61.Claisen, L., 129.Classen, A., 36.Claudin, J., 103.Clemens, C. A., 147.Clotofski, F., 15.Cohen, C., 177.Cohn, R., 151.Collie, J. N., 128.Conradt, K., 159.Cook, J. W., 103.Cook, 0. W., 81.Cooper, P. A., 237.Copaux, H., 162.Costa, J., 159.Coulthard, A., 87.Coward, K. H., 185.Cox, H. E., 12.Cribier, J., 160.Crommelin, C. A., 9.Crussard, L., 24.Cshnyi, W., 158.Cummins, A. B., 198.Cushny, A. R., 186.Cuy, E. J., 3, 14, 57.Daish, A. J., 206.Dakin, H. D., 134, 168.Daniels, F,, 12.Darke, W. F., 25.Das, S., 198.Dautwitz, W., 153.David, W.T., 24.Davies, W., 83.Davis, A. R., 205.Davis, W. A., 206.Dede, L., 25.Demoussy, E., 205.Dempster, A. J., 35.Denham, W. S., 75.Denis, W., 147.Dennison, D. M., 236.Dereser, R., 121.Derx, H. G., 86.Desmet, G., 38.Desvergnes, L., 147.Dhar, N. R., 20.Dieckmann, W., 153.Diels, O., 80.Dijk, C. van, 160.Dimroth, O., 135.Dixon, H. B., 2.Dobbie, (Sir) J. J., 144.Dodd, A. H., 167.Dorfmuller, G., 173.Doubleday, (Miss) I., 118.Dowell, C. T., 207.Driver, J., 28.Drucker, C., 17.Drummond, J. C., 185.Duclaux, J., 61.Dufraisse, C., 85.Dushman, S., 12INDEX OF AUTHORS’ NAMES. 245Dutt, P. K., 80.Dziewonski, K., 104.Dzrimal, J., 91.Effront, J., 113.Ehrenberg, P., 197.Einstein, A., 1.Eissler, F., 169.Eliasberg, P., 204.Elveden, (Viscount), 202.Embden, G., 162, 183, 184.Emslander, R., 53.Englert, F., 153.Ephraim, F., 42.Erbe, R., 85.Eucken, 1, 8.Euler, A.C. von, 207.Euler, H. von, 27, 154.Evans, B. S., 161.Evans, C. L., 163.Evers, N., 155.Ewing, (Sir) J. A., 1.Ewing, W. W., 6.Fairchild, J. G., 165.Fajans, K., 14, 16, 26.Fales, H. A,, 18.Farbenfabriken vorm. F. Bayer &Fargher, R. G., 127, 189.Farmer, E. H., 97.Fazi, R. de, 152.Feigl, F., 155.Feist, K., 129, 144.Ferla, J., 81.Fiesel, H., 24.Firth, J. B., 27, 28, 58.Fischer, E., 63.Fischer, F., 19, 238.Fischer, H., 124.Fischer, O., 138.Fisher, E. A., 149, 196.Fleischer, K., 99, 102.Florentin, D., 148, 166.Flury, F., 53.FGldi, Z., 79.Foerster, F., 43, 163.Folin, O., 147, 150.Foote, H.W., 51.Formhals, R., 158.Forster, M. O., 21.Fournier, L., 189.Franzen, H., 155.Fraps, G. S., 198.Fred, E. B., 177, 207.Fresenius, L., 149, 199.Freudenberg, E., 187.Freudenberg, K., 129, 207.Freund, J., 149.Freund, M., 145.Freundlich, H., 27.Co., 188.Friedliinder, P., 126.Friend, J. A. N., 38.Fritsch, A., 159.Froidevaux, J., 150.Fromm, E., 125.Fry, W. H., 149, 195, 199.Fiirth, R., 25.Fukuda, M., 25.Fulmer, E. I., 185.Furukawa, S., 190, 191.Gadamer, J., 143, 144, 145.Gardner, J. A., 154.Garner, W. E., 14.Gautier, A,, 148.Geilmann, W., 150, 194.General Electric Co., 148.George, H. J., 15.Germann, H. C., 173.Gersdorff, C. E. F., 207.Gerth, O., 18.Gibson, D.T., 135.Giemss, G., 140.Gile, P. L., 197, 205.Gilmour, G. van B., 154.Givaudan & Co., L., 90.Glasstone, S., 49.Glattfelder, A., 109.Gmachl-Pammer, J., 19.Gmelin, H., 57.Goadby, A. K., 43.Godon, F. de, 63.Goldschmidt, H., 20.Goldstein, H., 102, 108.Gomberg, M., 79.Gordon, J. R., 169.Gorter, K., 143.Grab, M. von, 176.Graebe, C., 131.Granacher, 60.Grafe, E., 184.Grafton, E. H., 6.Graham, V. A., 155.Grandmougin, E., 103.Green, A. M., 117.Griffin, E. G., 174.Grimm, H., 14.Groth, P., 241.Grube, G., 57.Griin, A., 64, 91, 153.Griinhut, L., 155.Griiss, J., 151.Guhot, L., 189.Gunther, P., 2.Gutbier, A., 53.Gyemant, A., 26.Gyorgy, P., 187.Haag, J. R., 196.Haaa, A., 5.Hackh, J.W. D., 145246 INDEX OF AUTHORS’ NAMES.Haeften, F. E. van, 83.Haendel, L., 187.Haerdtl, H., 170, 207.Hagenbocker, A., 109.Hahn, A., 174.Halberkann, J., 140.Haller, H. L., 139.Hallimond, A. F., 239.Halstead, C. F., 196.Hammick, D. L., 7, 43.Hanke, M. T., 14.Hansen, R., 202.Hantzsch, A., 115.Harden, A., 178, 185.Hardy, F., 197.Harger, R. N., 150.Harkins, W. D., 6.Harms, H., 79.Harries, C., 45.Harris, J. E. G., 137.Harrison, W. H., 198.Hart, W. B., 152.Hartree, W., 184.Hartwig, E., 151.Hasenbaumer, J., 199.Hashimoto, T., 168.Hastings, A. B., 162.Hatcher, W. H., 42.Haupt, W., 149.Haw, A. B., 50.Haward, W. A., 24.Hawley, F. G., 163.Headley, F. B., 199.Hedelius, A. H., 27.-Hedley, T.J., 153.Heene, R., 135.Heidelberger, M., 13 8.Heidhausen, G., 10.Heiduschka, A., 153.Heilbron, I. M., 203.Heller, G., 114, 115, 116.Hemptinne, A. de, 58.Hendrixson, W. S., 164.Henglein, F. A., 9.Henley, F. R., 178.Henrich, F., 127.Henstock, H., 104.Hermans, P. H., 153.Herrmann, (Miss) L., 121.Hem, W., 2, 6, 7, 8, 9, 10, 14.Herzberg, 0. W., 42.Herzfeld, K. F., 11, 16.Herzig, J., 131.Herzog, R. O., 210.Hess, A. F., 186.Hess, K., 68, 74, 118, 143, 207.Hess, L., 46.Hettner, G., 5.Hevesy, G., 35.Heyn, M., 78.Hibbard, P. L., 197.Hieber, W., 153.Hilditch, T. P., 22, 69.Hill, A. V., 154.Hilton, H., 239.Himstedt, F., 2.Hinshelwood, C. N., 22.Hirsch, J., 176, 177.Hittel, H., 102.Hoagland, D. R., 193, 194.Hobart, F.R., 160.Hodges, J. H., 38.Honigschmid, O., 37.Hoffman, J. F., 163.Hofmann, F., 78.Hofmann-Meyer, (Miss) A., 135.Hollander, A. I. den, 83.Holleman, A. F., 83.Holluta, J., 158.Holmberg, B., 91.Hoover, C. R., 148.Hopff, H., 66.Hopkins, F. G., 181, 185.Hopwood, F. L., 227.Horlacher, E., 77.Horst, F. W., 158.Horton, E., 154, 206.Howe, P. E., 168.Hubenthal, H., 194.Hudleston, L. J., 55.Huffer, E. J. E., 83.Hughes, W., 15.Hull, A. W., 236.Hulton, H. F. E., 154.Hurd, A. H., 202.Hutchinson, A., 239.Hutchinson, H. B., 209.Hutchison, A. M., 114.Imes, E. S., 5.Ingold, C. K., 66, 94, 96, 97.Iredale, T., 27.Irvine, J. C., 74, 75.Jacobs, W., 115.Jacobs, W. A., 138, 171, 173.Jacobsohn, P., 114.Jaeger, F.M., 17.Jaeschko, W., 134.James, C., 38.James, R. W., 222, 237.Jancke, W., 210.Jantzen, E., 139.Jenkins, W. J., 60.Joetten, K. W., 187.Johns, C. O., 207.Johnson, E. B., 150, 151.Johnston, E. H., 12.Johnston, E. S., 205.Jolles, A., 165.Jones, D. B., 207.Jones, H. W., 205.Jones, J. S., 205.Jones, L. H., 205, 206INDEX OF AUTHORS’ NAMES. 247Jones, W., 171, 172, 173.Jonescu, A., 154, 162.Jorissen, W. P., 24.Joseph, A. F., 199.Kalb, L., 123.Kalle & Co., 109.Kallmann, H., 15.Kananow, G., 81.Kapf, S., 125.Kapma, B., 17.Karrer, P., 75, 76, 77, 81, 109, 169,170, 207.Karrer, W., 77.Katz, J., 55.Kautsky, A., 49.Kayser, M., 201.Keen, B. A., 200.Kehrmann, F., 113.Kelley, W. P., 198.Kenner, J., 87, 108.Kermack, W.O., 141, 142.Kessler, H. G., 56.Keutel, F., 1.Keys, D. A., 24.King, H., 105, 127, 189.Kinkead, R. W., 158.Kinner, G., 134.Kipping, F. S., 105.Kirsch, G., 3.Kirschbaum, G., 101, 102.Kittl, T., 159.Klein, O., 4.Kleine-Mollhoff, O., 199.Kleinmann, H., 147.Klemenc, A., 19.Klooster, H. S. van, 156.Knebel, E., 108.Knoch, F., 145.Kobel, (Miss) M., 134.Kohler, A., 145.Kanig, J., 199.Kanig, W., 138.Koenigs, E., 134, 139.Koessler, K. K., 14.Kohler, B., 159.Kohler, E. P., 112.Kohn-Abrest, E., 148.Kollo, C., 156, 161.Kolthoff, I. M., 27, 146, 157, 159, 160,163, 164, 165.Kon, G. A. R., 96.Konowalowa, A. A., 120.Konowalowa, R. A., 120.Korenchevsky, V., 186.Kostychev, S., 204.Kramer, R.L., 62.Kratzer, A., 5.Krause, R., 106.Krausz, E., 151.Kreitmann, L., 78.Kremann, R., 19.Krepelka, H., 36.Krishna, S., 131.Krohnert, E., 46.Kruyt, H. R., 25.Kuhn, E., 113.Kurtenacker, A., 159.Laage, E., 86.Laar, J. J. van, 10, 13.Lachman, A., 153.Liimmerhirt, E., 112.Laing, M. E., 25.Lambourne, H., 137.Lande, A., 4.Lang, L., 170.Lang, N., 144.Langhans, A., 156, 169.Langmuir, I., 11, 236.Lanzenberg, A., 61.Lapworth, A., 14, 78.Latshaw, W. L., 197.Lattey, R. T., 15.Lauder, A., 144.Leach, B. R., 202.Lebedeff, A. von, 183.Legatu, H., 205.Legerholtz, H., 144.Legg, D. A., 61.Leitch, (Miss), 74.Leitmeier, H., 45.Lemarchands, M., 160.Lemarchands, (Mme.) M., 160.Lemberger, Z., 104.Lemmel, L., 100.Lemmermann, O., 149, 199.Lenher, V., 53, 54.Lenze, F., 207.Leuchs, H., 119.Levaditi, C., 189.Levene, P.A., 171, 172, 173.Levin, (Miss) E., 100.Lewis, G. N., 19.Lewis, W. C. M., 11, 12.Lindh, A. E., 147. .Ling, A. R., 155.Lingen, J. S. van der, 235.Lipman, J. G., 196, 197, 202.Little, E., 159.Lizius, J. L., 157.Loeb, J., 26, 28.Lohnis, F., 202.Liiwenheim. (Miss) H., 145.Lombard, M.; 152:Loomis, F. W., 5.Lorenz, R., 14, 15,LovBn, J. M., 119.Ludwig, E., 157.Ludwig, R., 136.Ludwig, W., 104.Luff, G., 160.Lundell, G. E. F.,Lutz, O., 157.17.63248 INDEX OF AUTHORS’ NAMES.Maass, O., 42.Macallum, A. B., 150.McAlpine, R. K., 36.McBain, J. W., 25.Macbeth, A. K., 135, 162.MacCrtnn, G. F., 186, 187.McClelland, E.W., 114.McColl, A. G., 196.McCollum, E. V., 185, 186.MacDonald, M. R., 185.MacDougall, F. H., 1.Macgregor, A. M., 239.McKeown, A., 11.McLeod, C. M., 76.Madelung, E., 4.Mader, W., 77.Magasanik, J., 27.Magnaghi, P., 119.Mailhe, A., 63.Maki, T., 131.Mallaneh, S., 152.Malmy, M., 152.Mannich, C., 145.Maquenne, L., 205.Marcelin, A., 5.Marcusson, J., 194, 195.Marshall, A. G., 147.Martin, F. J., 199.Martin, H. E., 25.Martin, J. C., 193, 194.Martin, W. H., 196.Martinet, J., 126.Mathews, A. P., 182.Mathias, E., 9.Mathieu, L., 151.Matignon, C., 149.Matsuno, K., 27.Matula, J., 207.Mauthner, F., 90.Max, F., 122.Maxted, E. B., 22, 58, 73.Mayeda, S., 142.Mayer, F., 104.Mayer, H. F., 4.Mayer, M., 187.Maze, P., 204.Meier, H.F. A., 196.Meisenheimer, J., 4, 67, 81,118.Meister, W., 137.Mellanby, E., 185.Menaul, P., 207, 208.Mendel, L. B., 134.Merkel, P., 138.Messmer, E., 74.Meurice, R., 158.Meyer, F., 46, 56.Meyer, G., 10.Meyer, H., 135.Meyer, K. H., 21, 66, 80, 84.Meyer, J., 9.Meyer, R., 115, 126.Meyer, R. E., 131.Meyerhof, O., 174, 177, 183, 184.Meysenberg, L. von, 187.Michael, W., 17.Michaelis. L., 174, 175.Michalik,. R.; 174..Michel, E., 42.Micklethwait, (Miss) F. M. G., 87.Middleton, H. E., 149, 195, 199.Mibge, E., 202.Mignonac, 62, 76.Miller, H. G., 207.Mills, W. H., 137.Minovici, S., 162.Misslin, E., 80.Mitchell, A. D., 41.Mitchell, C. A., 146, 157.Miura, M., 185.Moers, K., 42.Moir, J., 149.Moldanke, K., 79.Monier-Williams, G.W., 74, 162.Moore, B., 203.Moore, C. J., 149, 195, 199.Moore, T. S., 118.Morel, H., 170.Morgan, G. T., 101, 127.Morgan, J. J., 161.Morse, W. J., 206.Moser, L., 159.Mudge, W. A., 18.Miiller, E., 178.Muller, J., 207.Miiller, J. H., 37.Miiller, O., 138.Muller, P., 150.Muller, W., 149.Mumm, O., 135, 136.Munter, F., 199.Murayama, Y., 89.NSigeli, C., 169.Nagai, S., 85.Nagayama, T., 177.Nanji, R. D., 155.Narbutt, J., 8.Nathansohn, A., 27.Neish, A. C., 161.Nelken, (Miss) A., 136.Neller, J. R., 206.Nelson, J. M., 174.Nelson, V. E., 185.Nemst, W., 22.Neu, W., 17.Neuberg, C., 176, 177.Ney, O., 36.Nicolas, G., 206.Nierenstein, M., 129.Niggli, P., 233, 241.Njegovan, V., 156.Noddack, W., 13.Nolte, O., 198.Nord, F.F., 177.Norris, W. S. G. P., 94INDEX OF AUTHORS’ NAMES. 249Northrop, J. H., 169.Noyes, A. A., 21.Noyes, W. A., 50.Nuti, M., 161.Oakes, E. T., 18.Obrist, J., 158.Oddo, B., 119, 204.O d h , S., 21, 28, 195, 200.Ogg, A., 227, 237.Ogier, J., 148.Oliveri-Mandala, E., 127, 157.Onnes, H. K., 9.Oppenheimer, E., 162.Osaka, Y., 157.Osswald, P., 17.Osterhout, W. J. V., 203.Ottenstein, B., 171.Ottmann, W., 139.Otto, A., 125.Paal, C., 58, 125.Palacios, J., 6.Palmer, (Miss) D. M., 22, 71.Palmer, W. G., 22, 71.Pappenheimer, A. M., 186.Park, E. A., 186.Parker, A., 2.Parker, F. W., 192.Parsons, C. L., 161.Parsons, L. W., 38.Paul, T., 190.Pauli, W., 25.Pealing, H., 224.Pearson, (Mrs.) L. K., 78.Pease, R.N., 4.Peiser, E., 171.Penfold, A. R., 89.Perkin, W. H., 86, 109, 126,141, 142.Perren, E. A., 66.Perrin, J., 12.Persch, W., 170.Peski, A. J. van, 63.Peter, M., 201.Peterson, A., 202.Peterson, W. H., 177.Pfiihler, E., 63.P f annens t iehl , 6 6.Pfenniger, F., 123.Pfieiderer, G., 19.Philippi, E., 127.Pickles, A., 28.Pierucci, M., 5.Pietrulla, H., 127.Pinkus, A., 18.Pittarelli, E., 151.Plant, S. G. P., 109.Pleus, B., 207.Plouski, M. L., 199.Podghka, J., 104.Polaoci, G., 204.130,PolBnyi, M., 11, 19, 27.Pollak, F., 19.Pommer, M., 99.Pommereau, H. de, 77.Porter, A. W., 15.Porter, L. E., 161.Porter, (Miss) M. W., 239.Preiss, F., 195.Priglinger, J., 127.Prince, A.L., 196.Pringsheim, H., 169, 170.Prud’homme, M., 13.Pummerer, R., 128.Purdie, T., 64.Pyman, F. L., 18‘3.Quisumbing, F. A., 154.Rabe, P., 139.Racke, F., 175.Rahn, F., 84.Ramm, (Miss) M., 113.Ramsauer, C., 4.Randall, M., 19.Rankine, A. O., 2, 3, 231.Rather, J. B., 151.Ravenna, C., 207.R a p e r , M. C., 208.Read, J., 89.Reed, H. S., 201.Reid, E. E., 62, 151.Reilly, (Miss) A. A. B., 128.Reiner, L., 25.Reinfurth, E., 176.Reinitzer, F., 91.Reis, A., 17.Reynolds, W. C., 6.Rheinboldt, H., 68.Rheiner, A., 159.Rheinheimer, W., 123.Richards, E. H., 209.Richards, T. W., 7, 36.Richardson, 0. W., 18.Richaud, A., 152.Rideal, E. K., 8, 11, 73.Riedel, F., 209.Rilliet, A., 78.Rippel, A., 204.Robertson, (Sir) R., 24.Robinson, E., 86.Robinson, (Mrs.) G.M., 76.Robinson, R., 120, 126, 141, 142.Robinson, R. H., 196, 197.Robl, R., 133.Rocasolano, A. de G., 21.Rodillon, G., 151. ,Rohrbecker, A., 100.Rolla, L., 161.Rona, P., 186.Rosenblatt, (Mme.) M., 205.Rosenfeld, S., 81.Rosenmund, K. W., 71, 79250 INDEXRosenthaler, L., 208.Ross, w. H., 55.Rosseland, S., 4.Rosset, H., 147.Rossner, E., 117.Roth, A., 136.Rothsteirz, M., 175.Rowe, F. M., 100, 117.Ruderer, H., 19.Bucker W., 2.Rudlinger, A., 109.Rum, R., 49.Ruff, O., 46.Ruggli, P., 116.Ruhemann, S., 128, 129.Russell, E. .J., 200, 201, 202.Rutherford, (Sir) E., 31.Ruzicka, L., 98, 140.Saar, R., 151.Sabalitschka, T., 155.SaiIer, G., 59.Salmon, C.S., 25.Samec, M., 170, 207.Sander, W., 115.Sands, J. E., 105.Sandstede, G., 144.Sasaki, T., 152, 167, 168.Sazerac, R., 189.Schaich, W., 121.Schattner, A., 159.Scheffer, A., 78.Scheibe, G., 117, 138.Scheibler, H., 125.Scheuermann, A., 17.Schimmel & Go., 191.Schlenker, E., 102, 108.Schmajewski, C., 113.Schmidt, H., 106.Schmidt, M., 125.Schmidt, M. P., 109.Schmitz, E., 184.Schneider, A., 155.Schneider, W., 145.Schoeller, W. R., 160.Schon, R., 129.Schofield, C. S., 199.Scholl, R., 103.Schollenberger, C. J., 197.Scholtz, F., 86.Scholze, J., 64.Schoonover, W. R., 202.Schotte, H., 74.Schottky, W., 10.Schrader, H., 155.Schroeter, K., 145.Schryver, S. B., 207.Schubert, J., 124, 125.Schuchard, F., 24.Schulek, E., 153.Schulthess, M.de, 18.Schulze, A., 15,OF AUTHORS’ NAMES.Schulze, W., 44.Schwendenwein, H., 4.Sears, G. W., 162.Seelhorst, C. von, 194.Segnitz, P. H., 158.Seidel, C. T., 140.Seka, R., 127.Semon, W. L., 43.Sen, H. D., 207.Senderens, 62.Sen-Gupta, N. W., 202.Shaxby, J. H., 10.Shedd, 0. M., 150, 198, 199.Sheppard, S. E., 25.Shipley, P. G., 186.Shive, J. W., 205, 206.Sido, M., 77.Siebert, S., 145.Siefert, F., 99.Sieg, B., 23.Siegbahn, M., 147.Sieglitz, A., 104.Siegwart, J., 79, 123, 124.Silberrad, O., 79.Simmonds, N., 186.Simmons, C. W., 159.Simon, L. J., 147.Simonsen, J. L., 90.Singh, H. D., 207.Sjoberg, M., 91.Skaupy, F., 2.Skita, A., 145.Skraup, S., 127.Smiles, S., 114.Smith, C.R., 26.Smith, H. G., 89.Smith, J. F., 126.Smith, T. O., 204.Somieski, K., 47, 48.Spath, E., 92, 141, 142, 144.Spencer, L. J., 239,Speyer, E., 145.Spirescu, (Mlle.) A., 157.Spoehr, H. A., 203.Staechelin, E., 18.Stanley, G. H., 160.Stapler, 67.Staszewski, W., 29.Staudinger, H., 79, 102, 108,123, 124.Stavenhagen, A. , 24.Steele, B. D., 128.Steinkoff, W., 124, 125.Stensson, N., 147.Stephen, H., 81.Stephenson, R. E., 196.Stern, R., 155.Stettbacher, A., 45.Steudel, H., 171.Stewart, G. R., 193.Stewart, 0. J., 38.Stook, A., 47, 48.Stoermer, R., 56,Stoll, A., 175INDEX OF AUTHORS' NAMES. 251Stoil6, R., 108.Straus, F., 100.Strecker, W., 52, 159.Stroud, W. H., 207.Stubbings, W.V., 87.Stutzer, A., 149.Sugden, S., 7, 41, 148.Sumner, J. B., 155.Suszka, J., 104.Sutton, J. R., 238.Svanberg, O., 154.Swanson, C. O., 19'7.Swarts, F., 77, 83.Sweet, S. S., 25.Swientoslawski, W., 9.Szanecki, J., 131.SzilQgyi, J. von, 52.Tague, E. L., 197.Takahashi, D., 186.Tammann, G., 13, 14.Tampke, H., 151.Tani, M., 38.Tartar, H. V., 43.Tausz, J., 201.Taylor, H. S., 23.Telfer, S. V., 187.Teodossiu, V., 156.Terres, E., 51.Thannhauser, S. J., 171, 173.Thaulow, K., 159.Thienemann, H., 52.Thies, W., 114.Thole, F. B., 114.Thomann, H., 77.Thomas, H. H., 239.Thomas, M. D., 193.Thomas, R., 41.Thorns, H., 46, 127.Thomsen, T. C., 147.Thomson, L., 80.Thorne, P. C. L., 22.Thorpe, J. F., 93, 94, 114.Thiiringer, V., 159.Thunberg, T., 180, 182.Titherley, A.W., 134.Tizard, H. T., 21, 147.Tochtermann, H., 80.Tolman, R. C., 11.Tomizawa, Z., 191.Tour, R. S., 148.Traube, W., 44, 52.Treadwell, W. W., 158, 159, 163, 164.Trebler, H., 98.Treichel, W., 138.Truffaut, G., 201.Tschermak, G., 241.Tscherne, R., 131.Tschitschibabin, A. E., 120.Tsujimoto, M., 65.Tucker, S. H., 126.Tutton, A. E., 219.Twitchell, E., 154.Ullmann, F., 113.Ulpiani, C., 117.Vandenberghe, H., 148, 150, 165.Vargolici, V., 154.Vaubel, W., 156.Venkataramaiah, Y., 4 1.Verein igte C hinin - Fabri ken Z imme r& Co., 139.Vining, D. C., 101, 102.Virtanen, A. J., 2 7 , 92.Vixseboxse, H., 21.Voss, H., 112.Viirtheim, A., 161.Vuillaume, M., 26,Wachsler, R., 131.Wadsworth, R. V., 155.Wagenmann, K., 164.Wagner, C. R., 55.Wagner, M. B., 15.Waitz, L., 109.Walden, P., 16, 17.Waldschmidt-Leitz, E., 21, 72, 101,Walker, S., 182.Wartenberg, H. von, 23.Waterhouse, E. F., 160.Waterman, H. G., 207.Waters, H., 163.Weinberg, A. von, 17.Weinhagen, A. B., 157.Weiser, H., 51.Weitz, E., 78, 136.Weizmann, C., 61.Weller, R., 140.Wells, R. C., 157.Wenyon, C. M., 188.Westbrook, L. R., 21.Whinyateb, L., 88, 89.Whitby, A., 160.Whitehead, H. R., 80.Whiting, A. L., 202.Wichers, E., 57.Widder, R., 2.Widman, O., 134.Widmark, E. M. P., 20.Widmer, F., 207.Wieger, B., 118.Wiegner, G., 27.Wieland, H., 84, 117, 118, 123, 178.Wiesmann, H., 199.Willard, H. H., 36.Williams, E. T., 41.Williams, M., 154.Willstatter, R., 21, 66, 72, 101, 128,143, 168, 175.Wilsdon, B. H., 200.Wilsey, R. B., 237.Wilson, C. H., 37.168252 INDEX OF AUTHORS’ NAMES.Wilson, R. E., 21.Winkler, L. W., 156, 159, 160, 164,Wirth, T., 153.Wislicenus, W., 85, 207.Witham, E., 108.Wittek, H., 134.Wittka, F., 64.Witzemann, E. J., 178.Wohl, A., 126.Wolff, E., 177.Wolff, P., 102.Woodward, H. E., 152.Woog, P., 6.Wormall, A., 80.Wrangell, M., 198.Wutke, J., 119.Wyant,, Z. N., 201.165.Wyckoff, R. W. G., 235.Yamazaki, E., 10.Yanagisawa, H., 153.Yeoman, E. W., 47.Yoshimura, K., 207.Young, W. J., 183.Zappper, R., 46.Zeiss, H., 187.Zenghelis, C. D., 156.Zetzsche, 71.Ziegler, K., 61.Zijp, C. van, 156.Zilva, S. S., 185.Zimmermann, W., 156.Zinke, A., 91.Zsigmondy, 25

ISSN:0365-6217    

DOI:10.1039/AR9211800243

出版商:RSC    

年代:1921

数据来源: RSC

摘要:

INDEX OF SUBJECTSAbietic acid, constitution of, 91.Acenaphthene, structure of, 215.Acenaphthene group, 102.Acetaldehyde, formation of, fromacetylene, 60.reduction of, 61.detection of, 151.Acetic acid, cyano-, ethyl ester,syntheses with, 66.Acetoacetic acid, ethyl ester, 66.Acetone, formation of, from aceto-acetic acid, 20.Acetylene, compound of mercuricchloride with, 60.Acetylsulphuric acid, 63.Acids, aliphatic, and their deriv-fatty, preparation of, from hydro-saturated and unsaturated, separa-Aconite, detection of, 152.Adipic acids, ad-dibromo-, isomerismof, 86.Adsorption, 27.Adularia, structure of, 234.Agricultural analysis, 149.Alabandite, structure of, 235.Alcohols, and their derivatives, 61.Alicyclic group, 93.Alkali metals, crystal structure ofisomorphous compounds of, 23 1.Alkaloids, 139.in plants, 207.Alkylation, 120..Alloys, electromotive force of, 19.Aluminium, atomic weight of, 36.separation of, 161.Amines, aliphatic, separation of, 155.primary, preparation of, 76.Amino-acids, synthesis of, 167.estimation of, 168.Amino-alcohols, preparation of, 77.Ammonia, action of chlorine with,atives, 62.carbons, 60.tion of, 65.in analysis, 146.primary, preparation of, 61.50.storage of, 51.detection of, 156.Ammonium carbonates, 5 1.haloids, structure of, 236.Amy1 alcohols, fermentation, dehydro-Amylase, 173.Amyloses, 75, 169.Analysis, agricultural, 149.electrochemical, 162.gas, 148:uiorganic, 155.organic, 15 1.physical, 146.water, 164.genation of, 62.Aniline, estimation of, 155.Anthracene, structure of, 213.Anthracene group, 102.Anthrone, preparation of, 103.Antimony, atomic weight of, 36.crystal structure of, 237.detection of, 156.separation of, 160.Stibiothiosulphates, 52.of halogens in, 79.Aromatic compounds, replacementArsanthrene, preparation of, 123.Arsenic trioxide, oxidation of, 19.organic compounds, heterocyclic,detection of, 156.estimation of, 158, 160.122.Arsinic acids, 106.Association of liquids, 8.Asymmetric rearrangement, 1 19.Atoms, structure of, 224,226.Atomic diameters, law of, 228.light, impact of a-particles on, 31.theory, 31.weights, 36.table of, 229.Azo-compounds, reduction of, 20.Barium tetroxide, 44.“ Bayer 206,” 187.8-Benzildioxime, 88.Benzoylcamphor, tautomerism of,Bismuth, atomic weight of, 36.21.crystal structure of, 237.25254 INDEX OF SUBJECTS.Bismuthines, 106.Boron nitride, preparation of, 46.sec.-Butyl alcohol, preparation of, 61Cadmium, atomic weight of, 37.estimation of, 159.Caesium hydride, 42.Calcifuges, 208.Calcium, metabolism of, 185.arsenide, preparation of, 46.carbonate, crystallisation of, 45.tetroxide, 44.Carbohydrates, 73.Carboligase, 177.Carbon monoxide, explosion of, 23.estimation of, 148.dioxide, estimation of, 164.See also Charcoal, Graphite, andDiamond.Catalysis, 38.Catalysts, influencing of, 7Lmetallic, adsorption of gases by,23.Catalytic hydrogenation, 69.Cells, electrochemical, effect offluorescent colouring matters on,18.Cellobiose, methylation of, 74.Cellulose, conversion of, into glucose,methylation of, 75.Chalkacene, 104.Charcoal, adsorption by, 27.Chemical dynamics, 19.Chemotherapy, 187.Chlorine, action of ammonia with, 50.heptoxide, 56.detection of, 149.74.Chromium, estimation of, 161.Cinnamic acids, isomerism of, 86.Cobalt, detection of, 156.estimation and separation of, 160,163.Colloids, 24.Colour in relation to molecularColouring matters, fluorescent, effectCombustion, 23.furnace, 153.Condensation, 8 1.Copper as a catalyst, 71.structure, 4.of, on electrochemical cells, 18.powder, action of nitrogen peroxideestimation and separation of, 163.on, 43.Cotton-seed oil, reduction of, 22.Crystal lattices, size of ions in, 16.powder, use of, with the X-raystructure, progressive, law of, 231,Crystals, structure of, by X-rayspectrometer, 222.analysis, 210, 222.Crystals, curvature in, 240.velocity of decomposition of, 22.liquid, structure of, 235.“ Cupferron,” use of, in analysis, 161.Cyanines, 138.Cyclic compounds, formation andtransformation of, 107, 114.Dextrose, detection of, 151.estimation of, 154.Diamond, 238.Diazonium salts, 80.Dicarbazyls, 126.Dicyanodiamide, estimation of, inDiglycollimide, alkyl derivatives of,Diphenic acids, 6 : 6’-dinitro-, iso-n-Dipyridyl, preparation of, 135.Dolomite, formation of, 45.Dulcin, 190.fertilisers, 150.77.merism of, 87.Electrochemical analysis, 162.Electrode, potassium chloride-Electrolytes, strong, abnormality of,Electrolytic conductivity, 15.Electromotive force, 18.Electrons, collision between mole-Elements, disintegration of, 31.Emulsions, three-phase, 25.Equilibrium, 19.Esterification, 79.E therifica tion, 7 9.Ethyl alcohol, estimation of, 153.Explosion, 23.Explosives, properties of, 24.calomel, 18.15.cules and, 4.mass spectra of, 33.Ferments, 173.Fermentation, 173.Fertilisers, 208.analysis of, 150.Fluorescein, detection of, 151.Fluorine :-Hydrofluosilicic acid, 55.Fluorspar, structure of, 225.Food substances, accessory, 185.Formaldehyde, detection of, 151.’‘ Fornitral,” use of, in analysis, 162.Gallium, estimation of, 161.Galloflavin, and its derivatives, 13 1.Gas analysis, 148.Gases, adsorption of, by catalysts, 23.inactive, heats of fusion of, 8INDEX OF SUBJECTS.255Gases, mixed, combustion of, 24.velocity of sound in, 1, 2.Gelatin, hydrolysis of, 168.swelling of, 26, 28.Germanium, atomic weight of, 37.Glucal, constitution of, 74.Glucinum, separation of, 161.Z-Glucosan, constitution of, 75.Glutathione, 181.Glycerides, constitution and synthesisGlycerol, estimation of, in wines, 153.Gold, separation of, 163.crystalline structure of, 236.Graphite, structure of, 211.Grignard’s compounds, constitutionof, 67.of, 64.colloidal, 24.Halogenation, 79.Heat, specific, 1.Heterogenous reactions, 22.“ Hoolamite,” 148.Humus, origin of, 194.Hydrazine derivatives, 80.Hydrindene group, 99.Hydrocarbons, 60.Hydrofluosilicic acid.See underFluorine.Hydrogen, molecular heat of, 1.occlusion of, by palladium, 22, 58,peroxide, preparation and pro-perties of, 42.catalytic decomposition of, 19.estimation of, 158.mination of, 162.acyl derivatives of, 82.73.sulphide, estimation of, 165.in water, 18.Hydrogen-ion concentration, deter-Hydroxylamine, transformations ofHypochlorites, estimation of, 162.Ice, structure of, 236.Indican, detection of, 165.Indicators, new, 157.Inorganic analysis, 155.Inulin, constitution of, 170.Invertase, 174.Iodine, adsorption of, 27, 28.Iodides, estimation of, 164.Iodic acid, reaction between potas-Iodates, estimation of, 164.sium iodide and, 20.Iodometry, 159.Ionisation, 15.Ions, radii of, 17.Iron, rusting of, 38.estimation of, 158, 160.Steel, analysis of, 161, 163.Isatin, isomerism of, and its deriv-Isomerism, geometrical, 85.atives, 116.structural, 115.Ketones, unsaturated, action ofKynurenic acid, synthesis of, 137.hydrogen peroxide on, 78.Lactacidogen, 183.Lactic acid, detection of, 151.Laevulic acid, estimation of, in foods,Laevulose, estimation of, 154.Lanthanum, atomic weight of, 37.Lead monoxide, modifications of, 49.tricyclohexyl, 106.estimation of, 159.Liquids, properties of, 8.Lithium hydride, 42.155.Magnesium carbonates, crystallisa-organic compounds, Grignard’s,dioxide, colloidal, 57.tion of, 45.67.Manganese, estimation of, 158, 160.Meconic acid, synthesis of, 127.Mercaptans, preparation of, 62.Mercury, isotopes of, 35.critical temperature of, 10.surface tension of, 6.purification of, 45.detection of, 156.estimation and separation of, 159,Mercuric azide, 45.Mercurous oxide, compounds of ,with ammonia and sulphurdioxide, 46.163.Metabolism, intermediate, 180.Metals, crystal structure of, 236.Methanetriacetic acid, 66.Methyl alcohol, purification of, fromMineral, new, from Rhodesia, 239.Mixtures, theory of, 15.Molecular conductivity, 15.Molecules, structure of, 2.Moonstone, structure of, 234.Muscle, chemistry of contraction of,acetone, 61.structure, 217.collision between electrons and, 4.183.Naphthalene, structure of, 212.Naphthalene group, 99.a- and &Naphthols, structure of, 216.Nephelometer, 147256 INDEX OF SUBJECTS.Nickel, atomic weight of, 38.as a catalyst, 70, 72.estimation and separation of, 160,163.Nitric acid, detection of, 157.Nitrogen, specific heat of, 1.fixation of, in plants, 207.compounds, organic aliphatic, 76.peroxide, action of copper powderin soils, 201.with, 43.Norharman, synthesis of, 141.Nucleic acids, 1'70.Organic analysis, 151.Orientation, 83.Osmosis, 28.Ouabain, detection of, 152.Oxidation, 78.Oxydisilin, 49.Ozonides, 52.biological, 179.Palladium as a catalyst, 72.Palmatine, constitution of, 144.a-Particles, impact of, on atoms, 31.Perillaldehyde a-anti-aldoxime, 191.Phenol, detection of, 151.Phenols, etherification of, 79.Phloroglucinol, acyl derivatives of,Phosphoric acid, estimation of, 162,Photochemical equivalence law, 12.Photosynthesis, 203.Physical analysis, 146.occlusion of, hydrogen by, 22, 58,73.81.165.properties in relation to constitu-tion, 13.Pikamar, 90.Pinabietic acid, 91.Pinene derivatives, 98.Piperitone, 89.Plants, alkaloids in, 207.colouring matters in, 208.constituents of, 206.copper in, 205.iron in, 205.manganese in, 205.nitrogen compounds in, 207.nutrition of, 204.starch in, 206.calcicolous, 208.living, chemistry of, 203.Platinum, colloidal, catalytic activitypurification of, 57.Polysaccharides, 169.Potassium hydride, 42.cyanide, crystal structure of, 237sof, 21, 72.Potassium iodide, reaction betweeniodic acid and, 20.detection of, 157.estimation of, 161.estimation of, in soils, 150.Prolylproline anhydride, y-hydroxy-,168.Proteins, 167.Pyridine group, 134.Pyrone group, 127.Pyrrole derivatives, 124.Quantum theory, 10.Quinine, detection of, 152.Quinoline group, 13 7.Radiation, 10.Rays, Rontgen, intensity of reflec-analysis of crystal structure bymeans of, 210, 222.tion of, 222.Reduction, 77.Refractometer, direct-vision, 239.Resorcinol, acyl derivatives of, 8 1.Rhodacene, 104.Rickets, 185.Ring formation, 107.transformations, 114.Rubidium hydride, 42.Saccharin, 190.Salt hydrates, vapour pressure of, 21.S alvarsan, sulphur - c on taining con -Scopoline, methylation of, 143.Selenium, colloidal, 53.stituent of, 105.oxychloride, 53.Selenates, double, crystallographySilicohydrocarbons, 105.Silicon hydrides and their derivatives,47.Silver, colloidal, 24.crystalline structure of, 236.haloids, structure of, 237.iodide, heat of formation of, 18.Sinapic acid, synthesis of, 92.Soap curds, 25.Sodium perborate, formula of, 43.ferrate, 57.ferrite, 57.hydride, 42.Disodium hydrogen phosphatehydrates of, 43.iridosulphite, 59.platinisulphite and platinothio-sulphate, 59.detection of, 157.constituents, 194.of, 232.Soil acidity, 195INDEX OF SUBJECTS. 257Soil, effect of salts on, 198organisms in, 201.solution, 192.sterilisation, 202.temperatures, 200.water in, 200.analysis of, 149, 199.Sound, velocity of, in dissociatingSpectra, mass, 33.Spectrograph, vacuum, 147.Starch, constitution of, 170.gases, 1, 2.potato, methylation of, 76.estimation of, 154.Steel.See under Iron.Stereoisomerism, 118.Stibinic acids, 106.Stibiothiosulphates. S e e under Anti-mony.Strophantin, detection of, 152.Styrenes, bromo-, isomerism of, 85.Substitution, 83.Succinyldiacetic acid, 66.Sulphuric acid, estimation of, 164.Sulbhur organic compounds; hetero-cyclic, 123.Surface tension, 5.Sweetening agents, artificial, 190.Tartaric acid, detection of, 151.Tellurium, atomic weight of, 38.Terpene, new monocyclic, 89.Thallium hydrogen fluoride, 47.Theobromine, separation of, 155.Thermo-elements, 19.per- and tri-Thiocarbonic acids, saltsof, 47.Thiocyanic acid, tetramethylammon-Thionbenzoyl chloride, 79.Thiophen derivatives, 124.Thorium-B, adsorption of, by silverThorium oxide as catalyst, 62.Thulium, atomic weight of, 38.&Tin, true nature of, 239.Tissue oxidation, 178.Titanium peroxide and its complexsalts, 49.Truxillic acids, 86.Truxinic acids, 86.ium salt, ionisation of, 17.haloids, 26.Uric acid, and its derivatives, 132.methylation of, 121.Vanadium, estimation of, 161.Vapour pressure of salt hydrstcs, 21.Viscosimeter, 147.Vitamins, 185.Volumes, molecular, 4.Water, hydrogcn-ion concentrationin, 18.analysis of, 164.X-rays. See Rays, Rdntgen.Zinc, atomic weight of, 38.Zirconium oxide as catalyst, 63.estimation of, 160.REP. VOL. XVIII PRINTED IN GREAT BRITAIW BYRICHARD CLAY &5 SONS, LIMITED,BUNGAY, SUFFOLK

ISSN:0365-6217    

DOI:10.1039/AR9211800253

出版商:RSC    

年代:1921

数据来源: RSC