摘要:

ANNUAL REPORTSOX TI1 16PROGRESS OF CHEMISTRYANNUAL REPORTSON THEPROGRESS OF CHEMISTRYF O R 1914.lSSUED BY THE CHEMICAL SOCIETY.H. BILERETON BAKER, N.A., D.Sc.,J. N. COLLIE, Ph.D., F.R.S.A . W. CROSSLEY, D.Sc., Ph.D., F.R.S.F. G. DOXNAN, M.A., Ph.D., F.R.S.HERNARD DYER, D.Sc.11. 0. FORSTER, D.Sc., Ph.D., P.R.S.F. R. S.T. 31. LOWRY, D.Sc.W. H. PERRIN, Sc.D., IjL D., P. R.S.J. C. PHILIP, D.Sc., Pl1.D.F. B. POWER, Ph.D., LL D.A. SCOTT, MA., I).Sc., F.It.8.G. SENTER, D.Sc., P1i.D.Y. SniILm, D.Sc.@;bitor :J. C. CAIN, D.Sc., Ph.D.53 ttb- Qbitor :A. J. GREENAWAY.atxhtatrt S,ub-&hilor:CLARENCE SM rm, D. 8c.E. C. C. BALY, F.R.S.T. V. BARKER, M.A., B.Sc.D. L. CHAPXAN, M.A., F.R.S.F. G. HOPKINS, M.A., M.B., D.Sc.,J. C.IRVINE, D.Sc., P1i.D.F. R. S.G. CECIL JONES, F. I.C.N. H. J. MILLER, PI1 D.F. SODDY, M.A., F.R.S.A. W. STEWART, D.Sc.J . F. TIIORPE, D.Sc., Ph.I)., F. R.S.VOl. XI.L O N D O N :GURNEY & J ACK S O N , 33, PATERNOSTER ROW, E.C.1915PRINTED IN GREAT BRITAIN BYRICHARD CLAY AND SONS LIMITED.BKUNSWlCK STREET, STAMFORD STREET, S.E.,AND BUNGAY, SUFFOLKCONTENTS.PAGEGENERAL AND PHYSICAL CHEMISTRY.F.R.S. . . . . . . . . . . . . 1INORGANIC CHEbIISTR‘I’. By E. C. C. BALY, F.R.S. . . . . 34Pait ~.-ALIPHATIC DITISIOX. By J. C. IRVINR, D.Sc., Ph.D. . . 6398By L). L. CHAPMAN, M.A.,ORGANIC CHEMISTRY :-Part II.-HOMOCYCLIC DIVISION. By J. F. THORPE, D.Sc., Ph.D., F.R.S.Part III.-HETEROCTCLIC DIVISION. By A. w. STEWART, D SC. .. 121ANALYTICAL CHEMISTRY. By G. CECIL JONES, F.I.C. . . . . 161PHYSIOLOGICAL CHEMISTRY. By F. G. HOPKIW, M.A., M. B., D.Sc.,F.R.S. . . . . . . . . . . . . 188AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.By N. H. J. MILLER, Ph.1). . . . . . . . . 213MINERALOGICAL CHEMISTRY. By T. V. BARKER, M.A., B Sc. . . 238RADIOACTIVITY. By FREDERICK SODDY, M.A., F.R.S . . . . 26TABLE OF ABBREVIATIONS EMPLOYED I N THEABBREVIATED TITLE.A . . . . .Amer. J. Sci. . .Amdyst . . .Amulen . . .Ann. Bot. . . .Ann. C'l~ina. . .An7~. Chiin. anal. .A ~ L . ClLim. i6ppEic'nluAWL. C h i m l'hgs, .Awn. Inst. Pnslez~t .Ann Physik. . .A m . Report . .Arch. Y I L L L ~ L . . .Arkiv. Kem. Mi)&. Gcol.Atti 1;. Accccd. Lincci .Ber. . . . .Ber.Dezct. ltot. G'es. .Em. Dcut. physih-al. Ca.Bietl. Zcwti.. . .L'ir,cht m. 13~12. . .Bio-Clwn. J. . .Biocli e m . Zeitsch . .Boll. C'iim. Farm. .Bot. Zentr. . . .Bull. Acatl. ~ o y . Bclg.REFERENCES.JOURNAL.. Abstracts in Journal of the Chemical Society.' . Anierican Journal of Science. . The Analyst.. . AiiiJals of Hotany. . Aniialcs cle Chiinie. .. Aiinali di Chimicn Applicata.. . Aniialcs de I'Institnt Pasteur.. Aiinaleii cler Physik. .. Arcliiv dcr Pliainiazie. ....... Eiochemical Bulletin. . The Bio-Chemical Journal. . Biochemische Zeitochrift. . Kolletino chimico farmaceutico. . Botanisches Zentralblatt. .J ustus Liebig's Annaleii dar Cheuiie.Aiinalrs tle Chiiiiie nnalytique ,zppliqiGe A l'Iiidustrie,h l'Agriculture, j la Phariiiacie et h la Hiologie.Aniiales dc Ohinlie e t dc Physiqnc.Annual Reports of the Cheiiiical Society.Archiv fcir Kenii.Alincralogi och Gcologi.Atti clella Reale Accademia dei Lincei.Barichte der Deutschen cliemischen G esellschaftBericlite der Dentschen botanischen Gesellscliaft.Bcrichte dcr Deutsclieii physikalischen Gesellscliaft.Biederrnann's Zentralblatt fiir Agrikulturclieniie iuidrationellen Lsndwirtschnfts- Betriel).Academic royale de Belgique-Bulletin de la Classedes Scieiices.Bdl. Acnd. Sci., ,St. Pe'tcrs- Bulletin de YAcadeinie ImpQriale des Sciences doBull. kioc. chim. . . Bulletin de la SociBt6 chimiquc de France.Btcll. SOL china. Belj.8 ~ 1 1 . SOC. frnnq. Miit.Centr. Bakt. Par. . . Centralblatt fur Bakteriologie, Parasite11 kundc uiidCliem.and Drz6g. . . Chemist and Druggist.C'iem. NGWS . . . Chemical News.G'hem. Rev. Fett. Haz. -1,id.Chem. Weekblad . . Chemisch Weekblad.C h m . Zeit. . . . Chemiker Zeitung.Compt. rend. . . . Comptes rendus liebdoinadaires des Sdauces deDeutscih. med. ll'ochcnsch. . Deutsche niedizinische Wochenschi ift.Gazzetta . . . . Gazzetta chimica italiana.J. Agric. Sci. . . . Journal of Agricultural Science.J. Arner. Chem. SOC. . , Journal of the Anierican Chemical Society.J. is'io2. Chent. . . . Journal of Biological Chemistry, New York.J. Bd. Agric. . . . Journal of the Board of Agriculture.J. Chiin. P7~p. . . . Journal de Chimie physique.bourg . . . . St. Pdtersbourg... Rulletin de la Societh cliimique de Eelgique.Bulletin de la SociBt6 franqaise de Mindialogie.Infektionskrankheiten.Chemischc Revue' iiber die Fett.-und Ham. -1ndiistrie.1'AcadBmie des Sciences.The year is not inserted in references t o 1914viii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.J. Coll. Sci. TCky6 . .J. FralLklin Inst. . .,I. Hyyianc . . . .J. Ind. Eng. Chenz. . .J. Im?. Breming. . .J. Phcwm. C h . . .J. Phys. . . . .J. PJtysical Chem. . .J. Physiol. , . .J. pr. Chent. . . .J. Roy. Ayric. SOC. . ,J. RZLSS. PJQIS. C'henz. -Sot. .J. SOC. Chcm. I d . . .J. SOC. Dycrv . . .Kolloid. ZeatsciL. . .Lundtu. Jahrb. . . .Landto. Vemtchs - Stat. .Monatsh. . . . .Phciim. Zentr.-h. . .PJd. Hag. . . .Phil. Trans.. . .Physikal. Zeitsch. . .P . . . . . .Proc. Amer. Acad. . .Proc. Can~b. PhiL SOC. .Proc. AT. Akud. Wetcnsch.Ainsterdam. . . .Proc. PJqpical SOC. London.Proc. Aoy. Soc, . . .Iiec. truv. chim . . .Sitzunysber. K. Akad. Wiss.Berlin. . . . .Skand. Archiv. Physiol. .South African J. Sci. . .T . . . . * .Trans. Turaday SOC. . ,Yerh . Ges . dezbt. AITit 1'16rf v rsch .Aerzte . . . .Zeitsch. anal. Chem. . .Zeilsch. ungew. Chent. .Zeitsch. anorg. Cham. , .Zeitsch. Biol. , . .Zeitsch. Elcklrockcm. . .Zeitsch. Garzmgsphysiol .Zeitsch. Kryst. Min. . .Zeitsch. Nahr. Genussnz. .Zeitsch. physiknl. Chem. .Zeitsch.. physiol. Chem,. .Zeitsch. Ztdcerind. Bohnt. .JOURNAL.Journal of the College of Sciciice, TGky6.Journal of the Fran1;lin Institute.Journal of Hygiene.Journal of Indnstrial and Engineering Chemistry.Journal of the Institute of Brewing.Journal de Pharniacie e t de Chimie.Jouriial de Physique.Journal of Physical Chemistry.Journal of Physiology.Journal fiir praktischc Chemic.Journal of the Royal Agricultural Society.Journal of the Physical and Chemical Society ofJournal ofthe Society of Chemical Industry.Journal of the Socicty of Djers a i d Colonrists.Kolloid-Zt.itsclirift.J~andwirtschaftliche Jahrbiichcr.Die landwirtschaftlichen Vcrsuchs-Stationen.Monatshefte fiir Cheniie und vcrwaiidte Theile audererW issensch afte n .Pharniaceutische Zeiitralhalls.Philosophical Magazine (The L6ndon, Edinburgh andPhilosophical Transactioos of the Royal Society ofPhysiknlisclie Zeit schrift.Proceedings of the Chemical Socicty.Proceelliugs of the American Academy.Proceedings of the Cambridge Philosophical Society.Koninklijlte Akadeniie van Wetenschappen te Amster-Proceeding3 of the Loiiclori Physical Society.Proceedings of the Royal Society.Recenil des travaus chimiquea 'des Pays- Bas e t de laRelgiquc.Sitzungsberichte der Kijnjglich Prcussisclien AkademieSkandinavisches Archiv.fiir Physiologie.South African Journal of Science.Transactions of the Chemical Society.Transactions of the Faraday Society.Verhandlnng der Gesellschaft deutscher NnturforscherZeitschrift fiir analy tische Chemie.Zeitschrift fiir angewandte Chemie.Zei tsc hrif t fur an organ ische C 11 eniic.Zeitschrift fiir Biologie.Zeitschrift fiir Elektrochemie.Zeitsch. fiir G~~rongsphysiologie.Zeitschrift fiir Krystallographie and Mineralog2e.Beitschrift fur Un tersuchung der Nahrungs- undZeitschrift fur physikalische Chemie, StochiometrieHoppe-Seyler's Zeitschrift fiir physiologische Cheniie.Zeitschrift fiir Znckerindustrie in Bohmen.Bussia.Dn bli n ).Loncloii.dam. Proceedings (English version).der W i sscnscliaften zu Berlin.und Aerzte.Genussmit tel.und Verwandtschaftslehre

ISSN:0365-6217    

DOI:10.1039/AR91411FP001

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.DURING the year, a very large number of papers have been pub-lished which come within the purview of this Report. It isimpossible t o do more than refer to a very few of these, and i t iswith some regret that so many interesting investigations are ofnecessity omitted. A t the same time, there have appeared papersof outstanding interest and importance-papers which seem likelyto mark this year as above other years.There is little doubt that the general trend of inorganic chem-istry is on philosophic rather than purely preparative lines. Lessinterest must surely be found in the reading of the characterisationof new compounds, however novel these may be, than in the read-ing of pioneer work which marches steadily on into the unknown,bearing down old conventions where such oppose it, confident inits sense of conscious.merit, and safeguarded by its sense of trueproportion.Sure of its inherent accuracy and fully aware of itsrevolutionary influence on the treasured tenets of the chemistry ofyesterday, such work must rivet the attention of all. When onthe one side he is confronted with the disintegration of elementsunder electric stresses, and on the other he learns that the1 atomicweight of certain elements can vary by as much as 1 per cent.,according to the parentage of those elements, and when, again, heis told that the physical constants of metals as now known areworthless, because they are perpetually in a state of change fromallotrope to allotrope, the chemist of to-day may be likened to hisforefather of preWAvogadro days.As did his forefathers of thosedays, so also does he now await that great generalisation whichshall co-ordinate and link up all the threads to found a new philo-sophy. Radioactivity, enhanced line spectra, the intra-stellarelements, active nitrogen and oxygen, atomic disintegration,atomic-weight variation, each at the moment a watertight cornpart-ment of research, all will be unified and embodied in the newphilosophy of the twentieth century. Then will a new chelmistryin its greater meaning emerge as a phoenix from the glowingparental fires of the many chemistries of to-day.Little apology is needed for the pages in this Report which have3INORGAPU'IC CHEMISTRY. 35been devoted t o those investigations which are leading to theinception of the new philosophy.It is impossible t o pass by with-out special notice Collie's work on the disintegration of certlainelements, the work of Soddy and Hyman, Richards and Lembert,and of others on the atomic weight of lead. As regards the latterwork, a suggestion as to there being more than one inhabit'ant ofeach gap in the periodic table! was put forward by Sir W. C'rookesmany years ago, before radioactive phenomena were known. Madeas i t was to explain certain facts then under discussion, thissuggstion was forgotten, together with the facts. It was reservedfor Soddy and Fajans independently to enunciate their hypothesis,basing it on sound argument. It is inherently startling in concep-tion, and one is privileged t o ask how many elements are likely tobe concerned and how many atomic weights may be rendered in-secure.One could have wished that by some yet unknown processof radioactive disintegration the formation of the rare earths couldbe explained. It would be far more satisfactory could one lookupon these mysterious elements as the final products of changefrom elements which occupy legitimate positions in Mendelhev'stable. They would then be considered as parasitical growthsarising from elements formed, no doubt, by natnral synthetic pro-cesses. Be that as i t may, there is no doubt that the new workon the atomic weight of lead is thoroughly sound, and that i tsupports the hypothesis of Soddy and Fajans in a most remarkableway.As regards the work of Collie, there now seems little doubt ofits absolute validity. First put forward last year in a somewhattentative fashion, the very definite results recently recorded byCollie, Patterson, and Massori bring conviction in their wake.This work is critically discussed in the Report, and nothing furtherneed here be added.The remainder of the Report follows the lines of those of previousyears, but, as was stated above, some regret is felt that want ofspace compels the omission of much that is interesting.A tomic Il'eights.The year has been signalled by very remarkable work on theatomic weight of lead of radioactive origin.I n last year's Reporton radioactivity, Professor Soddy gave an account of the generalisa-tion which, amongst other facts, involves the existence in some ofthe places in the periodic table of several elements, differing inatomic weight, but remarkably similar in other properties.Itfollows that all the radio-elemsnts which are chemically identicalin character should occupy the same position in the periodic table.0 36 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Such elements are termed isotopic. The unknown end-products ofall the known disintegration series fall into the place occupied bylead. I f these products are entirely stable, the lead from radio-active minerals should differ in atomic weight according t o theamount of thorium or uranium in the mineral. The atomic weightof the thorium isotope should be 208-4, and that of the uraniumisotope should be 206.0. The experimental results obtained infour different laboratories support this in a very remarkable way.In the first case, the atomic weight of the lead in Ceylon thoritewas determined.1 An analysis of this mineral showed thepresence of 61.95 per cent.of Tho,, 0.85 per cent. of U,O,, and0.39 per cent. of PbO. The very small quantities of lead suggestthat it is all of radioactive origin, none being present as anoriginal constituent. If that be so, then the atomic weight of thelead should be about 208.2, since 10 parts of it arise from thoriumto 1 part from uranium.The lead was extracted from a kilogram of the mineral, andafter the most careful purification about 1.2 grams of lead chloridewere obtained.The atomic weight of this lead was compareddirectly with that of the lead in a sample of the chloride preparedfrom the ordinary nitrate in the same way as was the mineralspecimen. The two specimens were compared by titration withsilver nitrate solution, the methods of weighing being those adoptedby Baxter and Wilson in their work, on which the internationalvalue is mainly based. I n one set of experiments the ratio of theatomic weight of the lead from thorite to that of ordinary leadwas found to be 1.0049, whilst in a second set it was 1.0042. Theatomic weight of the lead from thorite was therefore 208.5 and208.3, respectively, in the two sets of determinations. The differ-ence between this and the accepted value is far greater than theprobable error of experiment unless unknown sources of error exist.A still more striking result has been obtained in the Harvardlaboratories,2 for in this case lead of radioactive origin from severalsourcm was used, and the values of the atomic weight were foundto differ very considerably, according to the origin of the lead.Itis not necessary here to enter into a description of the methodsemployed in the purification of the various samples of lead chlorideor of the details of the analysis which evolved the determinationof the ratio P b : Ag. They were carried through with thataccuracy with which the name of Harvard is associated. It mayperhaps be stated that the determinations made with any onesample of lead chloride agreed exceedingly well amongst them-F.Soddy and H. Hyman, T., 1914, 105, 1402.T. W. Richards and M. E. Lembert, J. Avncr. Chem. h'oc., 1914, 36, 1329;A . , ii, 653INORGANIC CHEMISTRY. 37selvee.atomic weights of the lead from the various sources being given:The result may be tabulated as follows, the values of theLead from N. Carolina urnnin i te ..................... 206 '4Leal1 from Joachinisthal pitchblende ............... 206 57L e d t'rorn Colorado carnotite ........................ 206.59Leal1 from Ceyloiiese thorianite ..................... 206.82Lead from English pitchblende ..................... 206.84Coninion 1, ad,.. .................................... 207.1 5Without doubt, these results are exceedingly remarkable, andthey undoubtedly support the generalisation as to isotopic elements.They are entirely contrary to experience, for very careful investiga-tions at Harvard have failed to reveal any difference whatever inthe atomic weights of copper, silver, iron, sodium, and chlorineobtained from the most varied sources possible.Again a spectrographic investigation of the lead of radioactiveorigin showed no difference between it and ordinary lead.Soddyand Hyman, however, found that one line, 1=4760-1, is muchweaker in the case of the " t'horite " lead.The above results have received further confirmation. I n onecase, the atomic weight of lead from pitchblende was found byBaxter's method to be 206.736 as a mean of nine determinations.3I n the second case,4 lead was obtained from various radioactiveminerals, and the atomic weights were determined by the Stasmethod from the ratio1 P b : Pb(NO,),.The lead from uraniumminerals gave an atomic weight between 206.36 and 206.65, whilstthat from monazite gave 207.08, the value for ordinary lead fromgalena being taken as 207.01.As regards the report of the International Committee, no changeis recommended in the values given in the table published in 1913.The report draws attention to certain investigations of varyingimportance that have been carried out. Reference may be madeto one or two of these, and certain papers since published.The density of oxygen has been redetermined after the gas,obtained in the first place by heating pure potassium per-manganate, had been carefully fractionated.5 The mean valuefrom fifteen determinations of the weight of a normal litre (OO,760 mm., sea-level, and a latitude of 45O) is 1'42906 grams.Incombination with the values obtained by Morley and by Rayleigh,the most probable value is 1.42905 grams.Some further work on the atomic weight of tellurium has beencarried out by the conversion of tellurium hydride, TeH,, into0. Honigschmid and (Mlle.) St. Horovitz, Compt. Tend., 1914, 158, 1796 ;A., ii, 655.31. Curie, ibid., 1676 ; A., ii, 563.A . F. 0. Germann, %id., 1913, 157, 926 ; J. C ' h i ~ . phys., 1914, 12, 66 ; A , , ii,47, 45438 ANNUSL REPORTS ON THE PROGRESS OF CHEMISTRY.tellurium dioxide, Te0,.6 The hydride was prepared fromaluminium telluride, and also by the electrolysis of a 50 pelr cent.solution of phosphoric acid with a tellurium cathode and aplatinum anode.The gas was frozen in liquid air,and then formedwhite crystals, melting a t -57O and boiling a t Oo. The rwultssupport the view that, tellurium is not complex, and that the' pre-sent atomic weight, 127.5, is the correct value.The atomic weight of copper relatively t o t h a t of silver hasbeen determined by an electrolytic methcd,7 the weights of the twometals deposited by the same quantity of current being compared.The mean of ten values gives for the atomic weight of coppelr63.563 f 0.003 (Ag = 107.88).Two determinations have been made of the atomic weight ofmercury. I n the first, mercuric oxide was converted t o mercuryby heating with metallic iron,8 and the mean of nine very closevalues gave the atomic weight as 200-37kO-0'35. This value isconsiderably lower than the; accepted value, and the authors con-sidered that the discrepancy might be explained by the presenceof a small quantity of a higher oxide, but that the result calledfor a further investigation of the atomic weight.This has beencarried out recently by Easley and Brann's method of conversionof mercury into mercuric bromide.9 The values obtained laybetween 200.50 and 200.62, and as a mean of nine experime'nts thevalue of 200.57 +0.008 was deduced, a value which is in close agree-ment with that now accepted.The density of neon after purification from helium has beenredetermined by Leduc.10 This was experimentally found to be0.695, referred to air as unity, from which by his formula, theauthor calculates the atomic weight to be 20.15.Some criticisin has appeared of Auer von Welsbach's work onytterbium (aldebaranium) and lutecium (cassiopeium) , for whichhe found the atomic weights of 173 and 175 respectively.11 Theearths of the ytterbium group, in the form of their nitrates, havebeen submitted t o fractional crystallisation, the stages in theseparation being followed by measuring the coefficients of magnet-isation of each fraction.12 After 4000 crystallisations, eightL.RI. Dennis and Ic. P. Aitdersoii, J. Airier.. Chci~i. Sot., 1914, 36, 882 ;A . , ii, 456.7 A. G. Shiimpton, Proc. T'h?y~~im? SOC., J,ondo?l, 1914, 26, 292 ; A., ii, i 7 4 .G.B. Taylor aiid G. A. Hul~tt, J. Physicd C h i t . , 1913, 17, 755 ; A . , ii, 128.H. €5. Ijakcr a i d W. 11. Watsoii, 5"., 1914, 105, 2630.lo A. Lediic, Conzyt. T e f r d . , 1914, 158, 864 ; A., ii, 361.l1 iJIo?zntsh., 1913, 34, 1713; A . , ii, 130.l2 J. Kluiiieiifeld and G . Urlbdn, C'o?upt, ? * L ' ? L ~ , 1914, 159, 323, 401 ; if., ii,731, 694INORGANIC CHEMISTRY. 39fractions were obtained with the same coefficient, which is acceptedas proof of the existence of a definite substance. The metal of thenitrate corresponding with these sight fractions is called neo-ytterbium, and has an atomic weight of 173.54. The arc spectraof the first and the last' of these eight fractions were observed, andthey were identical except for a few rays in the one fraction duet o thulium, and a few in the other due t o lutecium.A ,?lo t ropy.Two new modifications of phosphorus have been discoveredduring the course of some experiments on the effect of high pressureon the melting point of ordinary white phosphorus.13 The first ofthese is a new form of white phosphorus, which changes reversiblyinto the ordinary modification, and the second is a form obtainedirreversibly from the ordinary form at high pressures and moderatetemperatures, and is 15 per cent.more dense than Hittorff'smetallic red phosphorus. The white modification was first pro-duced by increasing the pressure on ordinary phosphorus t o about11,000 kilogram/cim.2 at 60°. The transition temperature is alinear function of the pressure, and lies between -76.9O a t apressure of 1 kilogramIcm.2 and 64.4O at a pressure of 12,000kilogram/cm.2 By crystallisation from carbon disulphide a t lowtemperatures, the new modification was obtained in the form ofmicroscopic crystals belonging to the hexagonal system.The black modification is readily obtained by heating ordinaryphosphorus to ZOOo under a pressure of 12,000 kilogramjcm.2 Thedensity of this substance is very high, being about 2-69, as against1-83 for ordinary white phosphorus and 2.34 for Hittorff's metalliccrystallised red phosphorus.It is certainly a new form, and ischaracterised by not being spontaneously inflammable; it can withdifficulty be ignited, and may be heated to about 400° in air with-out catching fire.It bears some resemblance to red phosphorus inthat it is attacked by cold nitric acid, but not by sulphuric acid,and i t is not dissolved by carbon disulphide. When heated in aclosed tube it vaporises and condenses on the colder parts of thetube to a mixture of red and white phosphorus. It would seem,therefore, that the vapours of the black and the red forms are, a tleast in large part, identical. I n contradistinction from the red andthe) white varieties, i t is a fairly good conducttor of electricity, thespecific resistance being 0.711 ohm per cm. cube a t Oo. Theteniperature-coefficient has a large negative value, and the relationbetween temperature and resistance is nearly linear between 0'and 75O. The specific heat was determined between 100' and 30°,Id 1'.W. Bridgman, J. Amer. Chem. Soc., 1914, 36, 1344 ; A . , ii, 64740 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and was found to be 0-170, a value which is considerably lowerthan those recorded for the other modifications. The vapourpressure was determined, and was also found to be lower than thatof red phosphorus. The new form, therefore, appears to be morestable than the red variety.The investigations on the allotropy of the metals have cunsider-ably extended during the year, since copper, cadmium, and zinchave been added to the list of those which possess allotropic modifi-cations.14 The proofs of the existence of the different forms arebased on dilatrometric observations, and as yet the pure allotropesdo not seem to have been prepared.I n the case of copper, tchetransition temperature is 71'7O, and in the case of cadmium thetransition temperature is 64.9O. With both these metals, however,it has been found that the transition temperature depends upon theprevious thermal history of the metal, and therefore it is con-cluded that more than two allotropic modifications exist. Itfollows that these metals normally are metastable mixtures of a tIeast two allotropes, and that they are continually changing slowlyinto the stable modifications a t the ordinary temperature. Theseobservations are of considerable imporkance, for they show that thephysical constants of these metals, and in all probability of manyothers, have no definite significance. It will be necessary to re-determine these, and study the physico-chemical properties bymaking use of the pure allotropic forms.Certain anomalousresults on record are explained by this work, for example,Matthiessen and Bose's observation of the disintegration ofcadmium wires heated a t BOO, and also of changes in the electricalconductivity of copper wires after these had been heated forseveral days a t looo. It is probable that the stable form of zincwas obtained in an almost pure form by Kahlbaum, Roth, andSiedler.ls Again, the specific heat-temperature curves for copper,zinc, lead, aluminium, and silver are not continuous, but changeabruptly a t one or more points. This agrees with the dilatrometricobservations for some of these metals.Further work has also been carried out on the new form ofsulphur, S,, the discovery of which was noted in last year'sreport.16 A method has been worked out whereby the quantities14 E.Cohen and W. D. Helderman, Pruc. K. Aknci. Wetetcnsch. Amsterdam, 1913,16, 628; 1914, 17, 6 0 ; A., ii, 205, 654 ; ibid., 1913, 16, 4 8 5 ; 1914, 17, 54, 1 2 2 ;A., ii, 52, 652 ; ibid., 1913, 16, 565 ; 1914, 17, 59 ; A . , ii, 127, 652; Zeitsch.physikal. Chem., 1914, 87, 409, 419, 426 ; E. Cohen, €'roe. K. Akad. Fetensch.Amsterdam, 1913, 16, 632 ; 1914, 17, 200 ; A . , ii, 202, 799 ; Zeitszh. physiknl.Chem., 1914, 87, 431.15 Zeitsch. anorg. Chcm., 1902, 29, 177 ; A . , 1902, ii, 259.16 A. H. W. Aten, Zeitsch. physikal. Ciienz., 1913, 86, 1 ; A., ii, 121INORGANIC CHEMISTRY.41of S,, S,, and S, can be estimated in a given mixture of the three,and this has been applied to samples of sulphur which had beentreated in various ways. The velocity of change, S, --+ S,, hasbeen investigated, and it is found to be very great at first, but tofall rapidly t o a very small value when the quantity of S, presentis small. The maximum amount of S, which it has been possibleto obtain by heating sulphur to various temperatures is about 6.5per cent. after the sulphur has been heated to 1 8 0 O .A study has also been made of the effect of the three catalystssulphur dioxide, ammonia, and iodine, which are known t o havegreat influence oc the equilibrium S, S,. Ammonia was foundconsiderably to shift the equilibrium, with the result that thequantity of S, was reduced t o a very small value.The velocity ofthe change, S, - S,, is about the same whether iodine is presentor not. The bearing of the existence of S, as a factor in theequilibrium on the properties of sulphur was considered, and itwas shown that, in general, these are explained more satisfactorilythan is possible on the lines of the old two-component system.Thus the change in viscosity with temperature, and the variationin crystallisation power with previous thermal treatment, are shownto be far better explained when the presence of S, is taken intoaccount.Finally, analyses of solid sulphur, after treatment in variousways, are given, and it is shown that the quantities of S, presentare always exceedingly small, and never greater than 0.1 per cent.,and this only in sulphur that has been previously melted.Similarly, S, is only t o be found in sulphur that has previouslybeen melted, and the maximum amount formed was 0.5 per cent.These results are very different from those given by Kruyt,l7according to whom, sulphur which has been heated to 90° and 6 5 Ocontains 3 and 2.4 per cent.of S, respectively. Kruyt, however,estimated the amount of S, by the change in melting point, andnot by direct analytical methods.Electric Bischcirge.The work of Collie and Patterson and of Sir J. J. Thomson onthe production of helium and neon in vacuum tubes during thepassage of the electric discharge was dealt with a t some length inlast year's Report. During the year, several papers have been pub-lished upon this work, and there would seem to be' little doubt thatthe evidence in favour of the actual production of these gases bythe discharge ha5 been materially strengthened.A very obviouscriticism can be made of the detection of minute quantities of neonl7 Zeitsch. physikal. ChenL., 1908, 6%) 513 ; A . , 1908, ii, 102842 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in the residuum after all the diatomic gases have been frozen outby means of charcoal cooled in liquid air, namely, that this gasarises from very small quantities of air which had leaked into theapparatus during the experiment. Such criticism might a t firstsight seem to be justified, because two indelpendent observers havebeen unable to detect the production of either helium or neon whenthe possibility of leakage of air had absolutely been precluded.l* l9The fact that an exceedingly small quantity of air is necessary t ogive enough neon f o r spectroscopic detection was pointed out byStrutt, who found that 0.01 C.C.of air is amply sufficient. Thefailure of Strutt and of Merton t o observe the formation of eitherhelium or neon might therefore readily be interpreted as a some-what effective criticism of the apparatus used in those experimentsdescribed in last year’s report.The essential improvement in the new apparatus described byStrutt and by Merton lies in the fact that the gas, after it hasb&n subjected to the influence of the discharge, is not transferredt o a second apparatus for analysis.The whole operation is carriedout in one self-contained piece of apparatus, and in Merton’s ex-periments, after the gas to be experimented with had once beenintroduced, it did not come into co’ntact with any stopcocks. Asingularly ingenious method of introducing hydrogen into theapparatus was devised by Merton in the shape of a small palladiumtube sealed into a glass tube. The outer end of the palladium tubewas hermetically closed, and by heating this tube with a Bunsenflame, small quantities of hydrogen diffused into the apparatus,which had previously been exhausted. There is no need to describethe actual experiments, since they gave negative results, despitethe fact that they were similar in character to those previouslycarried out by Collie, Patterson, and Mason.Quite apart, however, from the later results published by Collie,i t does not seem possible t o accept such a simple explanation aswould seem to be suggested by Strutt and Merton’s work.Itmust not be forgotten, in the first place, that if the neon foundwere due to an exceedingly small air-leak, the amount of argonwould be enormously greater (700 times), and could not possiblyescape detection. I n the second place, the production of helium,which was so clearly noted in the early work, lies in a differentcategory. Whilst neon might conceivably be due t o air-leaks, theformation of helium in even greater amounts than the neon, whichwas definitely observed in several cases, can hardly be susceptibleof the same explanation.The amount of helium present in the airis far less than that of neon, and therefore an air-leak would give18 (IIon.) R. J. S t l u t t , Pmc. Koy. Suc., 1914, [ A ] , 89, 499 ; A . , ii, 201.19 T. R, Merton, ibid., [A], 90, 549 ; A,, ii, 726INORGANIC CHEMISTRY. 43the latter gas in considerable excess. With regard to the absenceof argon, there is just the possibility that it might have been re-moved by the charcoal along with the diatomic gases. Be thathow it may, there does not seem t o be the faintest possibility thatreasonable amounts of helium and little neon could be due to anundiscovered leak of air.The problem gained considerable interest when Collie,20 usingMerton's own apparatus, obtained considerable quantities of heliumand neon by the cathode-ray bombardment of powdered uraniummetal in an atmosphere of hydrogen.Five grams of the uraniumwere finely powdered in a stetel mortar, and then heated to red-ness in a vacuum f o r half an hour. The metal was then trans-ferred to a small bulb, in which it could be bombarded by thecathode streams, and this tube was sealed on to the Mertonapparatus. A small bulb containing charcoal, a hard glass tubecontaining copper and cupric oxide, and a small bulb containingphosphoric oxide, were1 also sealed to the apparatus. The wholewas washed out several times with pure oxygen, and then exhausteduntil the discharge would not pass. The tube containing theuranium was then heated as strongly as possible, and the gaseswere pumped off and examined.Carbon gases and hydrogen werepresent, but only just sufficient helium and neon to be detected inthe usual way. The tube was then again washed out with pureoxygen and re-exhausted to the utmost limit. A small quantityof hydrogen was admitted by heating the palladium tube for twentyto thirty seconds, so as to allow the discharge t o pass. The bom-bardment of the' uranium lasted for two hours, and during thistime carbon gases and hydrogen were evolved. These wereabsorbed by cooling the charcoal with liquid air and by heatingthe cupric oxide. At the end, considerable quantities of heliumand neon were found t o be1 present, and the experiment was re-peated several times with the same result. By slight variation inthe treatment of the gases, nitrogen was found in small quantities,but this disappeared after sparking above the mercury in the con-taining vessel.Only very small traces of argon were noted, sinceit showed only the blue spectrum. During these experiment8 thegases did not come into contact with any stopcocks, and thereforethe arguments against air-leaks as the origin of the monatomic gasesappear absolutely sound, and the results would seem to discountthe criticism that might have been based on Strutt's and Merton'swork.I n describing these experiments, mention is made for the firsttime of a fact which may give the key to the divergent results'Lo J. N. Collie, Prbc. Ii'oy. A'oc., 1914, [ A ] , 90, 554 ; A . , ii, 72744 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.obtained by the different observers, for it must be rememberedthat positive results were also obtained by Thomson, as well as byCollie and Patterson and by Masson, in 1913.I n one or two experi-ments Collie found that by using a larger induction coil with amercury break in place of the original 10-in. coil with a platinumbreak, no helium or neon was produced. On repetition of the ex-periments under exactly the same conditions, but with the old coil,i t was found that. the helium and neon were again produced to thesame amounts as previously. The very small traces of nitrogendetected in the residual gases after the charcoal had been cooled isattributed by Collie to the presence of some nitride in the uranium.The presence of this trace of nit”rogen and its spectroscopic detec-tion is of some considerable importance.It is a well-known factthat very minute quantities of nitrogen can be detected by meansof its spectrum, and, further, it is perfectly evident that onlyminute traces were present, since the gases had been for some timein contact with the charcoal cooled in liquid air. It may safely bededuced, therefore, that those positive results of helium and neonproduction when no nitrogen was observed (and these form byfar the h g e r majority) could not in any way be due t~ air-leaks.I n a recent paper the previous positive results are confirmed ina still more striking way, and also the question of possible air-leaks is very critically considered.21 The precautions taken againstsuch leaks are described in detail, and these leave no doubt that,whatever may be the origin of the production of helium and neon,it does not arise from faulty apparatus.I n this paper the detailsof the various types of apparatus used by these authors in theirseparate and individual experiments are described more minutelythan was the case in the previous papers. Very many differentdesigns of discharge tubes were used, some with outer jackels andsome without. In the case of the former, the jackets were eitherexhausted, filled with neon, or filled with water. Since these threealternatives made no apparent difference, it follows that the soleremaining possibility of external contamination is excluded,namely, the porosity of the glass of the discharge tube to heliumand neon only during the discharge. This indeed savours of hyper-criticism, but clearly even the most far-fetched hypothesis must betested.As stated in last year’s Report, both helium and neon werefound in the outer jacket when the experiments were carried outwith this vessel completely exhausted. This result, which has beenconfirmed, is perhaps the most extraordinary of all that have beenrecorded. It may be remarked here that numbers of control ex-periments were made, that is to say, the apparatus was left stand-J. N. Collie, H. S. Pattcrsoii, and I, Maason, Proc. Roy. Soc., 1914, [ A ] , 91,30 ; A . , ii, 847INORGANIC CHEMISTRY. 45ing under exactly the same conditions as in actual experiments, butwithout any discharge being passed.I n every such control nohelium or neon was found.A great number of different types of experiments have now beenmade, including the discharge between various metallic electrodes,the bombardment of various metals, oxides, and salts, and themercury arc lamp in silica tubes, with and without a water jacket.I n all three types, both helium and neon were found in varyingamounts. Many isolated experiments gave negative results, owingt o reasons as yet unexplained. The most important part of therecent paper, a t any rate to those who still maintain an attitudeof destructive criticism, lies in a detailed discussion of the possiblesources of error and the precautions that were taken against sucherrors.The question of atmospheric contamination must now betaken as being definitely decided, for the controls show that thereis no leak in the apparatus, and the sole remaining possibility ofthe permeation of air through the walls of the discharge tubeduring the experiment is negatived by the absence of the nitrogenand argon spectra, and also by the fact that the use of an outerjacket, which entirely covers the discharge tube, makes no appreci-able difference in the result.I n the writer’s opinion, the strongest evidence yet advanced forthe reality of the result is to be found in the fact that negativeresults are sometimes obtained, and that these have been traced insome casm to differences in the type of induction coil used.If,as now seems probable, the helium and neon are really disintegra-tion products arising from the effect ot the discharge, such negativeresults are bound to be obtained unless the discharge is tuned, asit were, to the tube used. I n the earlier experiments the authorswere fortunate enough in most cases to effect such tuning un-consciously, but when many and various types of tubes were triedthe natural result happened. Success and want of success followedone another in an apparently inexplicable way, owing to want oftuning. One thing a t least may besaid, namely, that the negativeresults must surely rule out air-leaks as contributory causes unlesssuch leaks exhibit a discontinuity in their behaviour, which wideexperience shows to be entirely foreign to their nature.It is a familiar fact to anyone who has carried out experimentson the phenomena taking place in vacuum tubes and electric dis-charge generally that the results obtained vary in a most perplex-ing way.The principal source of such variations seems to lie inthe induction coil, the capacity of the discharge tubes, the natureof the discharge, etc. Such results afford keen disappointment tothe experimenter when first met with, but they fall into line a 46 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.once when their origin is explained. I n the present work, theirvery existence and their explanation, at any rate in many cases, bythe variation in electrical conditions do more t o establish thevalidity of the positive results than destructive criticism can everbe relied upon to effect.As regards the origin of these gases, i t was stated above thatthere can be little doubt but that they rise from atomic disintegra-tion under the influence of the discharge.Sir J. J. Thornson, aswas detailed in last year's Report, favoured the view that thehelium obtained had previously been occluded in the electrodesused or the substance bombarded. Against this view certain rigidtests must be recorded. I n the first place, the positive resultsobtained with electrodeless discharge tubes prove that metallicelectrodes are not necessarily the source, and, further, the produc-tion of helium and neon in the arc between mercury surfaces isagainst such a view, seeing that neither gas was obtained on boil-ing the mercury in a vacuum.Again, Collie, Patterson, andMasson did not experience the steady fall in the amounts of heliumand neon obtained when the same tube was used several times insuccession, as was noticed by Thomson. Further, the followingtests were applied in connexion with certain sets of experiments.Positive results of helium and neon were, for example, obtainedwith a jacketed tube with aluminium electrodes and with hydrogenas the gas. All air-leaks were precluded by the jacket and by thefact that every control experiment gave no trace either of heliumor neon. A quantity of the aluminium wire used in making theelectrodes was melted in a vacuum, but gave off no trace of eithergas, and the same was true of the glass out of which the tube hadbeen made.A further portion of the aluminium wire was thendissolved in air-free potassium hydroxide solution. The hydrogenevolved was passed over heated cupric oxide, and the residue wasexamined in the same apparatus as used for the discharge experi-ments. Similarly, a large quantity of the glass was powdered andacted on by potassium fluoride and concentrated sulphuric acid inthe absence of air. About 300-400 C.C. of silicon fluoride werecollected, and frozen out by means of liquid air. I n neither casewas any helium or neon found in the residual gases. Similarnegative results were obtained with old Ro'man and Chinese glasses.Some valuable support t o this is obtained from some tests carriedout by Sir J.J. Thornson, who found that aluminium salts gavethe same quantity of helium on bombardment by cathode rays,whether they were made from ordinary aluminium metal or fromthe same metal which had originally had helium forced into i t bybeing made the electrode of a helium tube. As Thomson says, thilNORGANIC CHEMISTRP. 47shows that solution can be trusted to eliminate adsorbed gas. Itis unreasonable, therefore, in the extreme to suppose that if heliumand neon were present as such in the materials used, they wouldnot be set free on dissolution which is accompanied by gas evolu-tion. Solution of aluminium in potassium hydroxide, for example,entails a far more thorough physical disintegration of the piece ofmetal than does the bombardment of its surface. The only tenablesupposition is that any inert gases physically admixed must be setfree; it is not possible t o assume that anything more than a physicaladmixture in the case of inert gases pre-exists in aluminium or inglass.The proved absence of neon and helium from the resultingproducts of chemical reaction must prove, therefore, that they areabsent altogether.I n conclusion, the case in favour of these gases being due toatomic disintegration seems overwhelmingly strong, and the writerfeels that no apology is needed for so full an account of this work,which must rank as one of the most remarkable investigations ofmodern times.Some noteworthy contributions have been made t o the problemof active nitrogen, first discovered by Strutt, and further dealt withby him in papers describeld in the Reports for 1912 and 1913.It,would seem that some doubt has been thrown on the mechanismof the production of the active nitrogen, that is t o say, whether i tis produced from absolutely pure nitrogen or whether a trace ofoxygen is a necessary factor. It might a t first be thought that i tis a matter of secondary importance as t o whether the oxygen isa contributory factor or not, seeing that the essential point hasclearly been established, namely, that an active nitrogen does exist.It must not be forgotten, however, that the mechanism of theformation of this gas is not understood, nor has the reason of itsabnormal reactivity ever been explained.I n last year’s Report mention was made of some experimentswhich seem to prove that the presence of oxygen is a necessity forthe activation of the nitrogen, but this statement was controvertedby Strutt himself. The original experiments were again repeated,and, in spite of Strutt’s contradiction, the authors maintained theirposition.22 The greatest possible care was taken in the making ofthe apparatus and in the filling of it with absolutely pure nitrogen.No fat was used on the stopcocks, and all traces of mercury vapourwere removed by means of gold-leaf cooled in liquid air.Severalseries of experiments were carried out, and in the last the nitrogenwas prepared in the apparatus by heating barium azoimide to 1 7 0 O .I n each case no sign of the Strutt phenomenon was observed unless22 E.T i d e and E. Domcke, Bw., 1913, 46, 4095; A., ii, 12248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.small quantities of oxygen were mixed with the nitrogen. Theoxygen was obtained by heating silver oxide contained in a smalltube sealed to the apparatus.A slightly different view of the plienomena has been put forwardby Koenig and Elod,23 for they differentiate between the after-glow(Strutt’s phenomenon) and the formation of the active nitrogen.The presence of the former is not necessary t o prove the existenceof the latter, a statement that is of some importance, since i t wasthe after-glow which Tiede and Domcke used as criterion of theformation of the active nitrogen. The real test for the presenceof active nitrogen lies in the reactions which can be carried out byits means.It was found, further, that active nitrogen can readilybe prepared by passing the pure gas, a t 15 mm. pressure, througha direct-current arc. The after-glow was then exceedingly wellmarked, and a number of new reactions of the activated nitrogenwere observed. For example, ethylene and acetylene react vigor-ously, the aftier-glow disappears, and the region where the twogases meet is marked by a lilac flame showing the spectrum ofcyanogen. Hydrogen cyanide is formed in a quantity correspond-ing with that found by Strutt. Pentane gives ammonia, amyleneand hydrogen cyanide.It was also found that when pure oxygen is passed through thearc, a weak, bluish-green after-glow is formed. I f the glowingoxygen is mixed with glowing nitrogen from a second apparatus,both glows are immediately extinguished, and oxides of nitrogenare formed in quantity.If the arc is extinguished in eitherapparatus, the formation of the nitrogen oxides ceases a t once. Itis concluded from these experiments that an active form of oxygenis produced, differing from ozone and capable of existing only f o ra short time.It may be pointed out that these results are in agreement with,and entirely confirm, those obtained by Lowry, and fully describedin the Report for 1912. This seems t o have escaped the notice ofKoenig and Elod, for they make no reference t o the fact that thephenomenon had previously been discovered by Lowry.I n a further paperF4 the results of Tiede and Domcke areadversely criticised.If mercury vapour is mixed with the nitrogen,the after-glow is not observed, although the active gas is still pro-duced. The presence of alkali metal vapour has a similar effect,and thus the suggestion is made that Tiede and Domcke’s resultswere due to the admixture of either mercury vapour o r potassiumor barium vapour (from the azoimides used to prepare the nitrogen).Tiede and Domcke, however, carried out experiments with23 A. Koenig and E. Elod, Ber., 1914, 47, 516 ; A . , ii, 264.lbid., 523 ; A., ii, 266INORGANIC CHEMISTRY. 49nitrogen fr9m which all the oxygen had been removed by means ofheated copper.25 They state that with this nitrogen the Struttphenomena are not obtained with iodine, sulphur, sodium, andthallium chloride, but the addition of the least trace of oxygen a tonce gives rise to the phenomena.I n this work, the alkali metalvapours were certainly absent, and the precautions for removingmercury vapour would seem amply to be sufficient, so that Koenigand Elod’s criticism does not appear t o be sound.Baker and Strutt, on the other hand, found themselves quiteunable to confirm these results, for on repeating the experimentsthey found the after-glow very pronounced, and also very decidedevidence of the activity of the nitrogen.26An interesting conclusion to the argument is arrived a t in ajoint paper by all four authors.27 It is explained that the contra-dictory results are due very largely t o differences in the apparatusused.Whereas with Tiede and Donicke’s apparatus the brightnessof the after-glow was increased by the addition of traces of oxygen,in Baker and Strutt’s apparatus no appreciable diminution in theglow was observed when absolutely pure nitrogen was used. Theconclusion is drawn that i t is probable that the production of activenitrogen is favoured by traces of oxygen, although in a suitableapparatus the result can be obtained even with the purest nitrogen.It is curious, however, that a real explanation of no activenitrogen being obtained by Tiede and Domcke is not given, unlessi t be attributed entirely to differences in the apparatus. If thisis so, it is another and mwt interesting instance of the necessityof tuning the discharge t o the type of tube used, such as wasreferred to above under Collie, Patterson, and Masson’s work.A tany rate, the criticism of Koenig and Elod is effectively met by thefacts published in the joint paper; this is pointed out in a finalcommunication.28Possibly this dependence on the relation between discharge andapparatus used is similar to that observed in the formation ofammonia from its elemenk under the influence of the silent dis-charge.29 I n this case, also, the amount of ammonia formed de-pends upon the dimensions of the apparatus and the density andthe oscillation frequency of the current.zi E. Tiede and E. Domcke, Ber., 1914, 47, 420 ; A . , ii, 196.26 H. B. Baker and R. J. Strutt, ibid., 801, 1049 ; A., ii, 357, 457.27 H. B. Baker, E.Tiede, R. J. Strutt, and E. Domcke, ibid., 2283; A . , ii, 724.28 E. Tiede and E. Domcke, ibid., 2284 ; A., ii, 724.M. Le Blsnc, Ber. K. Sachs. @:as. Wiss., Math.-phys. KI., 1914, 66, 38 ;A., ii, 809.REP.-VOL. XI. 50 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Group I .I n last year’s Report reference was made to the preparation ofpure anhydrous sodium monosulphide by the action of heat on thehydrosulphide. The action of sulphur on the hydrosulphide hasnow been investigated with the view of studying the polysulphidesof sodium.30 Approximately saturated solutions in alcohol of thehydrosulphide were heated on the water-bath with equivalent pro-portions of sulphur, and the product was either precipitated aftercooling by the addition of ether or recovered by evaporationof the solution.Amounts of sulphur corresponding with thedi-, tri-, tetra-, and penta-sulphides, as well as a large excess ofsulphur, were used. The results are interesting, because the onlypure solid compound obtainable by the above method was the tetra-sulphide, Na,S,. With smaller quantities of sulphur, mixtures ofthe tetrasulphide and hydrosulphide were formed, and with greaterquantities of sulphur the tetrasulphide, mixed with free sulphur,was obtained. On the other hand, there was definite evidence t oshow that higher polysulphides exist in the solution, and someindication was obtained that when a great excess of sulphur wasused, small quantities of higher polysulphides were mixed with thetetrasulphide when the latter was separated in the solid phase.Thesolution in such cases would seem to contain equilibrium mixturesof the tetrasulphide and higher polysulphides, and confirmatoryevidence of this was obtained by the determination of the hydrogensulphide set free by the mutual action of weighed amounts ofsulphur and sodium hydrosulphide in solution. The latter experi-ments certainly prove that the first action of the sulphur is to givethe tetrasulphide, and if insufficient sulphur is used to convert thewhole of the sodium hydrosulphide into the tetrasulphide, mixturesof the hydrosulphide and the tetrasulphide are obtained.By the action of metallic sodium on a solution of the tetra-sulphide in alcohol, the disulphide has also been prepared in a purestate. Sodium tetrasulphide, Na2S4, is a dark yellow, crystallinepowder with an olive-green tinge.It is extremely hygroscopic, anddissolves in water to give a deep orange solution, which turns redon heating. The disulphide, Na,S,, is a bright yellow, micro-crystalline powder, readily soluble in water t o a deep yellowsolution.By heating known quantities of water and finely pulverisedglasses of known constitution to high temperatures in a gold cruciblecontained in a special bomb, certain new crystalline alkali silicateshave been prepared.31 The temperature was measured by means30 A. Rule and J. S. Thomas, T., 1914, 105, 1’77.31 G. W. Morey, J. Amer. Chern. SOC., 1914, 36, 215 ; A , , ii, 202INORGANIC CHEMlSTRY, 51of a thwmo-couple, and was accurate to &5O.The following com-pounds were obtained : potassium hydrogen disilicate, KHSi20,,orthorhombic crystals which do not lose water at 350O. Thecrystals are very little affect'ed by water, and may be boiled forseveral hours a t looo without any appreciable decomposition.Potassium disilicate, K,Si,O,, a compound which is hygroscopic andvery readily acted on by water. Sodium disilicate, Na2Si20,, whichresembles KHSi20, in optical properties; the crystals may beleached with water, but on prolonged contact they are decomposed.Sodium metasilicate, Na2Si0,, forms crystals which are very readilydecomposed by water. This compound was previously known onlyin the form of somewhat indefinite hydrates.Some interesting work on nitrites may be referred t o in view ofthe bearing it has on the fixation of nitrogen.32 This reference mayconveniently be included here, in spite of the fact that much of i trefers to the next group.The nitrites of the alkali and alkalineearth metals can be prepared in the pure state only by doubledecomposition of silver nitrite with the chlorides of these metals,and in this way two new nitrites, LiNO,,H,O and Ca(N0,)2,4H,0,have been obtained. The hydrated nitrites generally can be de-hydrated in a vacuum over phosphoric oxide without decomposition.The solid nitrites and their saturated solutions are not oxidised byoxygen a t atmospheric pressure. Oxidation takes place only in thepresence of acid, when the free nitrous acid plays an importantpart in the reaction.The following double salts also wereobtained :N+&z(NOZ)OH~O, K,Ag,(NO2)4,H20, and BaAg2(NO,),,H20.I n the action of heat on sodium nitrite, the following reactionstake place in addition to the ordinary reactions:NaNO, + NO, = NaNO, + NO, ZNaNO, + NO2= 2NaNO,+ N.This explains the actions which occur when nitrogen peroxide actson calcium oxide and on the alkali and alkaline earth carbonates.When nitrogen peroxide acts on calcium oxide, there is always aloss of nitrogen, whatever be the conditions of temperature, inaccordance with the equation 2Ca0 + 5N02 = ZCa(NO,), + N, a factthat is of industrial importance.An investigation has been made of the composition of the solu-tions in equilibrium with the four salts potassium chloride, sodiumnitrate, sodium chloride, and potassium nitrate, which affords usefulinformation as to the most economical production of " conversion "saltpetre.33 I f a solution containing sodium nitrate, potassiumchloride, and water in the molar ratio 0'80: 0.62: 1.81 is evapor-32 M.Oswald, Ann. Chim., 1914, [ix], I, 3 2 ; A . , ii, 197.33 W. Reinders, Proc. K. Aknd. Wetensch. Amslerdam, 1914, I?, 1065; A., ii, 549.E 52 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ated a t looo, 0.42 mol. of sodium chloride is deposited. On cool-ing to 5O, the salts separate out in the proportion 0.575 mol. ofpotassium nitrate: 0.038 mol. of sodium chloride : 0.10 mol. ofsodium nitrate. If, however, a suitable amount of water is added,the separation of solid sodium chloride and sodium nitrate can beavoided, and 0.563 mol.of potassium nitrate obtained in crystals,which represents a yield of 90.8 per cent.Group IZ.Metallic strontium has been obtained by the electrolysis of thebinary mixture, strontium chloride-potassium chloride.84 A eutecticpoint occurs with the mixture containing 15 per cent. of potassiumchloride, and when the same method is used as in the case ofcalcium, sticks of strontium 10 cm. long and 1-2 cm. in diametercan be obtained. The mixture of chlorides melts a t 628O, which is220° below the melting point of strontium chloride. The currentdensity must be 20-50 amperes per sq. cm. of cathode, and theefficiency is then 80 per cent. Metallic barium has also beenobtained in a similar way.The investigation of the phase systems of calcium nitrate hasbeen extended to a study of the three-component system, calciumnitrate-lime-water.35 The nature of the solid phases capable ofexisting in equilibrium with aqueous solutions of calcium nitratecontaining lime was investigated a t 2 5 O and looo.Only onedefinite basic nitrate, Ca,N,O,, was found, which forms severalhydrates, containing 8, 1, 2, 3, and 4 molecules of water re-spectively. No series of solid solutions, Ca0,zN,0,,yH20, werefound such as postulated by Cameron and Robinson,36 nor does thehydrate, Ca,N,0,,3&H20, exist, as stated by these authors.Some interesting work on calcium sulphate may be mentioned inconnexion with its dehydration and commercial use as plaster ofParis.87 When gypsum is heated a t temperatures not above 210°,it becomes anhydrous, but the product is much less dense and moresoluble than natural anhydrite.The conversion of the hemihydratet o the soluble anhydrite, which is the last stage in the dehydrationprocess, is reversible, each process only requiring a few minutes at1100 in a dry and a humid atmosphere respectively. Since the hydra-tion to the hemihydrate takes place so easily, this salt naturally34 B. Neumann and E Rergve, Zeitsch. E'lcklrochem., 1914, 20, 187 ; A . , ii, 365.35 H. Rassett, jun., and H. S. Taylor, T., 1914, 105, 1926.36 F. K. Cameron and W. 0. Robinson, J . Physical Chenz., 1907, 11, 273;G. Gallo, Gazzetta, 1914, 44, 1, 497 ; A ., ii, 561 ; C. Gaudefroy, Compt. rend.,A,, 1907, ii, 444.1914, 158, 2006 ; 159, 263 ; A., ii, 650, 728INORGANIC CHEMISTRY. 53forms the principal constituent of plaster of Paris. The besttemperature for dehydration f o r commercial purposes depends uponthe humidity of the air in the oven, thus explaining the, variableresults that have been obtained. The hemihydrate dso absorbswater from the air a t the ordinary temperature up to a total water-content of about 8 per cent. Microscopic and calorimetric observa-tions confirm Le Chatelier's theory of the mechanism of the settingof plaster of Paris.Group IZZ.In the Reports for 1912 and 1913 reference was made to theisolation of the three hydrides of boron, B,H,, B4H10, and B,HI2.The first two compounds dissolve in alkali hydroxide, giving solu-tions which do not smell of the hydrides, but are unstable, and tendto give up hydrogen3* Since the lattar reaction takes place leasteasily with B4H10, this hydride was used in an investigation of theproducts formed when it is passed into aqueous alkali hydroxides.The first action takes place between one molecule of the hydride andfour molecules of a monacid and two molecules of a diacid base,according to the equationB4H10 + 4KOH = 4KOBH3 + H2.By treatment of potassium hydroxide dissolved in one and a-halftimes its weight in water with excess of B4H10 a t Oo, the solid hypo-borate was obtained in the form of colourless, octahedral crystals.The formula KOBH, was proved by analysis.This substance isstable in the absence of moisture; it is deliquescent, and its solu-tions decompose slowly at room temperature in accordance withthe equation2KOBH3 + 2H20 = ZKBO, + 5Hz.This reaction is brought about immediately by the addition of acid.The aqueous solution of the hypoborate is a very po,werful reducingagent.With copper salts it gives a precipitate of copper hydride,and with nickel salts a black, insoluble nickel boride, NiB,. Thiscompound is non-magnetic, but on heating to 500° it becomes mag-netic, a t the same time sintering to a grey, metallic form.When the compound KOBH, is heated at 500°, metallic potass-ium, hydrogen, and water are expelled, and the reaction is probablyexpressed by the equation5KOBH3= K3B503 + 2K + 2H2O + 11H.The residue, K3B503, is somewhat hygroscopic, and dissolves inwater to an alkaline solution, which has only a weakly reducingaction on potassium permanganate. It gives a characteristic yellowt o brownish-red colour when warmed with nitric acid, Whens8 A.Stock and E. KUSS, Ber., 1914, 47, 810; A., ii, 35954 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.treated with sulphuric acid, the compound gives hydrogen and boronh y dr ides.Sodium hypoborate, NaOBH,, was also prepared, and found topossess properties similar t o those of the potassium salt. No in-soluble hypoborates could be obtained by mixing a solution of thepotassium or sodium salt with those of other metallic salts.The reactions described in this paper are exactly analogous t othose described by Travers and Ray.39Two papers have appeared dealing with work on scandium."*41.Many ney salts of this element are described, and also the extrac-tion and purification of the oxide from wolframite.It is hardlynecessary to specify the new salts that have been prepared, but apoint of some interest is raised in the fractional separation of thescandium from thorium, yttrium, and ytterbium. An examinatioiiof 300 fractions showed that scandium is a uniform substance.The rose-yellow precipitate in the second analytical group was in-vestigated, and i t was found that; the claim previously made, thatthis is due to a new element, is not justified.42~43 This sulphide wasobtained in large quantities, and was proved to consist of coppersulphide with small quantities of tin and tungsten sulphides,together with much sulphur.Aluminium nitride 44 has been obtained in colourless, hexagonalneedles by heating the crude compound a t 2010-2030° in a tubeheated in a carbon resistance furnace in the presence of excess ofnitrogen.The cornpound dissociates when heated a t atmosphericpressure at 1850O.Mention was made last year of a paper in which doubt wasthrown on the existence of the aluminates as definite chemical com-pounds. This was controverted in a latea paper. Two furtherpapers453 46 have since appeared by the same authors, and thO ques-tion as to the existence of aluminates seems t o have been decidedin a third paper.*' Conductivity measurements show that suchcompounds must exist, for the measurements are definitely againstthe assumption of colloidal aluminium hydroxide. Moreover, whenii, 938.Zeitsch.anorg. Chevn., 1914, 86, 257 ; A , , ii, 269.39 M. W. Travers and R. C. Ray, Ptoc. -Roy. Soc., 1912, [ A ] , 87, 163 ; A., 1912,40 R. J. Meyer and, in part, A. Wassjuchnov, N. Drapier, and E. Bodlander,41 J. Sterba-Bohm, Zeitsch. Elektrochem., 1914, 20, 289 ; A . , ii, 565.42 M. Ogawa, J. CoU. 8ci. T6ky6, 1908, 25, xv, 1 ; xvi, 1 ; A . , 1908, ii, 952,45 A. Skrabal and P. Artmaon, Chcm. Zeit., 1909, 33, 143 ; A . , 1909, ii, 243.(4 J. Wolf, Zeitsch. anorg. Cheyn., 1914, 87, 120; A . , ii, 568.45 E. G . Mahin, J. Anzer. Chern. Soc., 1914, 36, 2381 ; A . , ii, 850.J6 W. Blum, ibid., 2883 ; A . , ii, 850.47 R.E. Slade and W. G. Polack, Trans, Faraday Soc., 1914, 10, 150 ; A , , ii, 811.953INORGANIC CHEMISTRY. 55hydrolysis takes place, the aluminium hydroxide is deposited in thecrystalline form. The arguments, therefore, are strongly in favourof the existence of aluminates as true chemical compounds.Group ZV.In the Report for 1912, the preparation of carbon subsulphide,C,S,, was referred to, this compound being produced by maintain-ing an arc bet'ween a graphite cathode and an anode of graphiteand antimony under carbon disulphide. By somewhat similarmethods, carbon sulphidotelluride, CSTe,48 and carbon sulphido-selenide, CSSe,49 have been obtained. I n the case of the former,the graphite and antimony electrode is replaced by one containing10 or more parts of graphite to 100 parts of tellurium.The carbondisulphide is then found to contain non-volatile decompositlion pro-ducts of carbon disulphide, and the compounds C,S, and CSTe,which are volatile with the carbon disulphide vapour. The separa-tion of these two compounds proved to be a very difficult matter,owing to the extreme ease with which the sulphidotelluride decom-poses. It was effected by a combination of two methods, namely:(1) the repeated fractional extraction of the C,S, from the solutionby carbon disulphide vapour, and (2) the conversion of the C,S,into thiomalononaphthylamide by its reaction with 8-naphthyl-amine. The dilute solution of the sulphidoklluride, after dryingwith phosphoric oxide, was concentrated on the water-bath to astrength of 5-10 per cent., using a Hahn fractionating column.The solution was fractionally distilled a t -30° under verydiminished pressure in a specially designed apparatus,50 and thepure sulphidotelluride was obtained in yellowish-red crystals, meltring a t - 5 4 O to a brilliant red liquid of high refractive power.Molecular-weight determinations with benzene and carbon di-sulphide as solvents gave values between 176 and 181, theory 172.The compound decomposes very rapidly a t room temperature, andis exceedingly sensitive to light, decomposition taking place even a t-5OO.No evidence could be obtained of the existence of carbonditelluride, CTe,.The sulphidoselenide, CSSe, was obtained in a similar way, theanode consisting of 17.5 parts graphite to 100 parts selenium. Thecompound was more readily isolated, owing to its greater stability.At room temperature the sulphidoselenide forms an intense yellowliquid, stable in air, and possessing a pungent odour of onions.Itdoes not take fire when brought into contact with the flame,4x A. Stock and P. Praetorins, Ber., 1914, 47, 131 ; A., ii, 199.49 A. Stock and E. Willfroth, ibid., 144 ; A., ii, 200,A. Stock, ibid., 1 5 4 ; A., ii, 17156 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.although the vapour of the boiling liquid burns with a beautifullilac flame. It melts at - 8 5 O , and boils a t 8 4 O , the vapour pressurea t loo being 45 mm. It is decomposed by light and on long keep-ing a t room temperature, but is much more stable than the sulphido-telluride.No evidence was obtained of direct union betveencarbon aria selenium by passing selenium vapour over carbon a t1000°, neither was i t found possible in any way to prepare carbondiselenide, CS%.Some doubt has been thrown on the constitution of white lead,51the view being expressed that it is not a true basic carbonate ofthe formula 2PbCO,,Pb(OH),. I n one paper a description is givenof a process by which white lead is obtained by spraying basic leadacetate solution a number of times through an atmosphere ofcarbon dioxide. The solid which Beparates a t first has the constitu-tion PbCO,,Pb(OH), ; on continued action of the carbon dioxide,this solid absorbs the gas, passing through the stage2PbC0,,Pb(OH)2,and finally becomes PbCO,.The increase in the percentage ofcarbon dioxide in the solid is gradual, and there is no evidence ofany break in the continuity at the stage 2PbCO,,Pb(OH),. Leadhydroxide is soluble in an aqueous solution of sucrose, but inno stage in the above process is there any loss in weight when thesolid is treated with sucrose solution. This dismisses the possibilitythat the solid phase is a mixture of lead carbonate and leadhydroxide. Further, a mixture of the compound PbCO,,Pb( OH),and lead carbonate in the correct proportions exhibits the sameproperties, both physically and as a pigment, as does ordinary whitelead.Further evidence is adduced in the second paper, for it is shownthat lead carbonate, when agitated with a solution of basic leadacetate, withdraws lead hydroxide. Again, in the case of the basiccarbonate, PbCO,,Pb( OH),, the percentage of carbon dioxide canbe increased or decreased a t will by agitation with neutral or basiclead acetate solution.Analogous results were obtained with basic zinc carbonate, pre-cipitated calcium carbonate, precipitated barium sulphate, andprecipitated barium carbonate, for these compounds on agitationwith basic lead acetate solution gave ZnC03,Zn(OH),,3Pb(O13)2,2CaC03,Pb(OH),, 3BaSO,,Pb(OH),, and 3BaC03,2Pb(OH), re-spectively.The barium carbonate and zinc carbonate compoundsequal white lead in their properties as pigments. Finally, the factthat white lead loses lead hydroxide when treated with ammoniumchloride solution shows that i t is more loosely combined than would51 E. Euston, J.Ind. Eng. Chem., 1914, 6, 202, 382; A., ii, 366, 465INORGANIC CHEMISTRY. 57be expected of a true basic salt. The view is put forward thatwhite lead is an adsorption compound of lead carbonate and leadhydroxide.An interesting method of decomposing natural phosphates andsilicates has been described.52 The powdered mineral is heated incarbonyl chloride vapour, the anhydrous metallic chloride beingformed in each case. The natural phosphates, vivianite, pyro-morphite, uranite, and monazite, are attacked at temperaturesbetween 300° and 500°, whilst the silicates, such as tho'rite,gadolinite, cerite, and zircon require temperatures of above 1000°.Emerald, however, is not decomposed a t 1400O.Group V .An investigation of the dissociation of gaseous nitrogen trioxide 53shows that the equilibrium conditions are somewhat complex, andnot to be represented by the two equationsThe pressure-volume relation has been determined for varioustemperatures and volumes of the gas, and h n alternative sets ofequations are considered in reference to the data thus obtained.The final conclusion is drawn that liquid nitrogen trioxide a t lowtemperatures consists mainly of N40, molecules, together with someN204, NO,, and NO molecules, according to the extent of the dry-ing.The vapour consists of a mixture of N406, N203, NO,, andNO molecules, reacting according to the equationN,O, zz N,O, + NO, + NO,mixed with some wet N204, NO,, and NO molecules.The effectof the prolonged drying of the liquid appears t o be to enable theNO, and NO molecules t o combine to give N406, which in the drystate dissociates to N,O,, NO,, and NO in equal volumes, the N203not further dissociating. It further seems likely that N406 mole-cules in the liquid state are blue, and that in the gaseous stateboth N406 and N203 are colourless, or nearly so. Ordinary wetnitrogen trioxide is green, owing to the mixture of blue N406 witha relatively large amount of wet NO,. The green colour is due tothe yellow molecules of NO, mixed with the blue N,06. At verylow temperatures all specimens of the liquid become quite blue,which is no doubt due to the fact that a t these temperatures theyellow NO, molecules completely associate to give the colourlessN204, which would no longer produce the green colour with theblue N406.Some measurements have been published of the vapour pressureN406 Z N204 + 2N0 and N,O, 2N0,.52 J.Barlot and E. Chauvenet, Compt. rc?Lcl,, 1913, 157, 1153 ; A . , ii, 49.ja B. M. Jones, T., 1914,105, 231058 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of 60lid nitrogen peroxide between -looo and -34O.W Thedynamical method was employed, the amount of vapour diffusinginto a known volume of hydrogen being determined. The vapourpressures lie between 0,0023 mm. a t -looo and 39.24 mm. a t-30°, and they are expressed by the curveMeasurements were made between -40° and -60° by a staticalmethod, and these are in good agreement.When a solution of ammonium phosphate (1.6 grams in 25 C.C.of water) is added to a solution of 1 gram of ferrous chloride in20 C.C.of alcohol saturated with nitric oxide a t Oo, the whole opera-tion being carried out in an atmosphere of nitric oxide, a blackish-brown, viscid oil is precipitated, which crystallises when cooled ina freezing mixture.55 The substance was obtained pure in the formof brown, flaky crystals, and has the formula Fe(NO)HPO,.Freshly precipitated ferrous phosphate also absorbs nitric oxide togive the same compound. Copper sulphate, chloride, and bromidecombine with nitric oxide according t o the reversible actionCUR, + NO Z CuR,NO.The combination takes place in alcoholic solution, the presence ofwater greatly diminishing the combination. Migration experimentsshowed that the brown, ferrous nitric oxide compounds containedthe complex cation (FeNO)", whereas in the green compounds acomplex ferrous anion exists.The combination with nitric oxideseems to be characteristic of the normal ferrous and cupric com-pounds, and not of those in which the metal is present in a stable,complex ion.A study of the phase diagram of the system ammonia and waterhas revealed the existence of two compounds, 2NH3,H,0 andNH,,%O, which melt a t - 78'9O and - 79*0° respectively.56 Theeutectic point a t which ammonia and the compound 2NH,,H,Oco-exist as solid phases lies a t 81-4 mols. per cent. of ammonia and-92'5O. The point a t which 2NH,,H,O and NH,,H,O co-exist liesat 58.5 per cent.of ammonia and -86O, and that correspondingwith the co-existence of NH,,H,O and ice a t 34.7 per cent. ofammonia and - 100.3O.Solutions of alkali or other chlorates, bromates or iodates, and ofhydrazine salts, may be mixed, and even boiled, without any reaction taking place.57 I f , however, a piece of tarnished copper wirelog p=14.9166 + e(o.0604).s4 A. C. G. Egerton, T., 1914, 105, 647.55 W. Manchot, Ber., 1914, 47, 1601 ; A . , ii, 567.56 A. Smits and S. Postma, Proc. K. Akad. TVetemch. Amsterdam, 1914, 17,57 W. R. E. Hodgkinson, J. SOC. Chem. I&., 1914, 13, 815 ; A., ii, 771.182 ; A., ii, 809INORGANIC CHEMISTRY. 59or a fragment of cupric oxide is introduced into a cold solution ofpotassium chlorate and hydrazine nitrate, nitrogen is evolved. Thereaction is accelerated by warming, and is quantitative in accord-ance with the equation2KC10, + 3N2H,,HN03= 6H20 + 3N2 + 3HN03 + 2KC1.The method may be used for the estimation of chlorates, bromates,and iodates.A slight exces of hydrazine salt is used, and theexcess is destroyed by potassium permanganate and nitric acid, whenthe resulting chloride, bromide, or iodide can be estimated.A considerable amount of work has been done on the nitrogenderivatives of sulphurous and sulphuric acids. By the action ofsulphur dioxide on ammonia in ethereal solution, amidosulphinicacid, NH,*SO,H, or its ammonium salt, NH2*S02N€I,, is formed,according as t o whether the sulphur dioxide or ammonia is inexcess.58 The free acid is a pale yellow compound, whilst the am-monium salt is a white substance.The compound N4H12S5010,previously dwribed by Divers and Ogawa, has been found not t oexist ; the substance originally prepared was impure ammoniumtrithionate.69Hydroxylamineisomonosulphonic acid, NH2*O*S02-O€I, was firstindicated by Raschig in the product formed by hydrolysis ofhydroxylamineisodisulphonic acid by hydrogen chloride.60 Thiscompound has now been obtained by the action of chlorosulphonicacid on hydroxylamine hydrochloride a t room temperature.61 Itseparates from a mixture of ether and methyl alcohol as a micro-crystalline powder; it liberates iodine from potassium iodide, andis hydrolysed in acid solution to hydroxylamine.Hydrazine hydrazinesulphonate has been obtained by aspiratingair first through a flask containing fuming sulphuric acid of highanhydride content, and then through a flask containing anhydroushydrazine.62 Considerable quantities of the salt are formed inaccordance with the equation 2N2H4 + SO, = H,N=NH=S0,H,N213,.The product is dissolved in water and heated with excess of bariumhydroxide in order to expel the unchanged hydrazine, the excessof barium is precipitated with carbon dioxide, and the filtrate fromthe barium carbonate is evaporated in a vacuum.A residue ofbarium hydrazinesulphonate, (N2H3*SO3),Ba,2H2O, is left, whichmay be obtained in glistening needles by solution in water andprecipitation with alcohol. The calcium salt, (N,H3*S03),Ca,H20,58 M.Ogawn. and S . Aoyama, Sci. Beports T6Roki~ Imp. Univ., 1913, 2, 121 ;A . , ii, 264.E. Divers and M. Ogawa, T., 1901, 79, 1102.F. Sommer and H. G. Templin, Ber., 1914, 47, 1221 ; A., ii, 458.6o F. Raschig, Annulen, 1887, 241, 161.62 W. Traube and 0. Vockerodt, ibid., 938 ; A., ii, 35860 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and the strontium salt, (N,H,*S0,),Sr,2H20, can be obtained in asimilar way.By double decomposition, using the barium salt and ammoniumcarbonate, ammonium hydrazinesulphonate, N,H,*SO,NH,, wasobtained as a deliquescent, crystalline mass. This salt is isomericwith hydrazine amidosulphonate.63.N,H,*SO,E,and the sodium salt, N,H3*SO3Na,H2O, were prepared in a similarway from potassium and sodium sulphates. The former crystallisesin needles and the latter in monoclinic tablets. All these salts arestable in alkaline and in neutral solution, but are decomposed byacid into hydrazine and sulphuric acid.From the barium saltand silver nitrate, the silver salt, N,H,*SO,Ag, was obtained inbeautiful listening needles. From the barium salt, by the actionof sulphunc acid, the free acid, N,H,*SO,H, was obtained inglistening needles, which melt and decompose a t 217O.I f a strongly cooled, aqueous solution of potassium nitrite istreated with finely powdered hydrazinesulphonic acid, the follow-ing reaction takes place:NH,*NH*SO,H + KNO, = 2H,O + N3S03K.From the resulting solution the salt, potassium azoimidesulphonate,has been obtained.It crystallises in long, flat prisms, which ex-plode on heating. The corresponding sodium, ammonium, andbarium salts have been obtained in a similar way.The potassium salt,' gGroup V I .Pure perchromic acid has been prepared by the interaction ofchromium trioxide and 97 per cent. hydrogen peroxide in methylether solution a t -3OO.64 The reaction takes place according tothe equationZCrO, + 7H,o,= 2H,CrO, + 4H,O.The blue solution was poured off the excess of eit,her chromiumtrioxide or hydrogen peroxide, dried over phosphoric oxide, andthen evaporated in a vacuum at -30°, when the acid was obtainedas a dark blue, crystalline mass, which decomposes a few degreesabove -3OO. Analysis shows that it has the formula H3Cr0,,2H,0,the water being water of constitution. The red perchromates areconsidered to be anhydro-salts of the blue perchromic acid, theirconstitution being E>Cr(O=OM),, whilst that of the acid is(HO),Cr(O*OH),.It is found that by the action of sulphuric acid on calcium63 A.P. SabanBev, J. Buss. Chem. Soc., 1899, 31, 375 ; A., 1900, ii, 13.64 E. H. Riesenfelcl and W. Mau, Ber., 1914, 47, 548 ; A , , ii, 279INORGANIC CHEMISTRY. 61fluoride it is impossible to obtain hydrogen fluoride of a greaterstrength than 95-96 per cent.6560. The best yield is obtained with90 per cent. sulphuric acid. When pure sulphuric acid is used,fluorosulphonic acid may be produced, and a quantitative yield ofthis acid may readily be obtained by heating calcium fluoride withfuming sulphuric acid containing 60 per cent.of the anhydride.The reaction takes place according t o the equationCaF, + H,SO, + 2S0, = CaSO, + 2F*SO,-OH.Sodium fluorosulphonate may readily be obtained by heating theacid with sodium chloride in a platinum retort under reflux. Boil-ing alcohol extracts the sodium fluorosulphonate, and, on cooling,this salt separates in iridescent plates or needles.Fluorosulphonic acid is decomposed on boiling with sulphuraccording to the equation2F*S02*OH + S = 3 S 0 , + 2HF.Group VZZ.A thermal analysis of mixtures of bromine and water leads t othe conclusion that the composition of the hydrate of bromineis Br2,8H,0.67 The crystals were centrifuged on kaolin a t 0" inorder to free them from any adhering bromine or water, and werethen analysed. The analytical results confirm the correctness ofthe above formula.An interesting study has been made of the relative stability ofpure calcium hypochlorite, bleaching powder, and a mixture ofcalcium hypochlorite and calcium chloride.68 Towards dry air, freefrom casbon dioxide, calcium hypochlorite and bleaching powdershow very little difference in behaviour a t 90°, there being only aslight loss of chlorine in each case.I n moist air containing carbondioxide a t room temperature, bleaching powder loses more of itsavailable chlorine than does the hypochlorite. The mixture ofhypochlorite and chloride behaves similarly to bleaching powder.I n an atmosphere of dry carbon dioxide, calcium hypochlorite losesa small percentage of its available chlorine after five hours' ex-posure; the mixture of hypochlorite and chloride loses a slightlygreater percentage, whilst bleaching powder loses all its availablechlorine. I n moist carbon dioxide, both the hypochlorite andbleaching powder lose all their available chlorine; the former, how-ever, gives hypochlorous acid as well as chlorine, whilst the latteronly evolves chlorine. With ammonia, both calcium hypochloriteand bleaching powder give an almost quantitative yield of nitrogen.0. Ruff and H. J. Braun, Ber., 1914, 47, 646; A, ii, 263.H. Giran, Compt. rend., 1914, 159, 246 ; A., ii, 723.66 0. Ruff, ibid., 656; A . , ii, 263.68 K. A. Hofmann and K. Ritter, Ber., 1914,47, 2233 ; A . , ii, 61262 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Group VIZl.Some attention has been paid to the question of the sorption ofhydrogen by 'O, 7 1 ~ 72. The curves obtained by plottingthe rate of solution as a function of the quantity of gas occludedconsists of two portions, indicating the occurrence of two distinctprocesses.70 The suggestion is made that there are two modifica-tions of palladium, which differ very considerably in respect oftheir activity towards hydrogen. The first portion of the velocity-concentration curve, on this view, is mainly determined by theactive form, whilst the second portion refers to the sorption of thehydrogen by th0 less active form. When palladium-black is used,a smooth curve is obtained, and the suggestion follows that thismaterial consists almost entirely of the active form. A somewhatsimilar view is put forward in the idea that palladium consists ofa crystalline form and an amorphous form, the latter being themore active.71Analogous results were obtained in a series of measurements ofthe electrical conductivity and the density of palladium wires con-taining measured amounts of occluded hydrogen.72Some experiments have been carried out on the nature of pre-cipitated nickel sulphide.73 It appears that there are threedifferent modifications, which differ in respect of their solubility inacids. The precipitates from a neutral solution of nickel chlorideand soluble sulphides consist mainly of a modification which dis-solves readily in acids. The less soluble modification is formed byboiling with water, or by long contact with a cold solution con-taining nickel, or with cold dilute acetic acid. All the modifica-tions have the same composition, NiS, and the most soluble is themost readily oxidised by air.a-Nickel sulphide is soluble in mineral acids down to O-O~LV,whilst P-nickel sulphide is fairly rapidly dissolved by 2N-hydro-chloric acid, and the y-modification is not appreciably dissolvedexcept on addition of oxidising agents. The differences in solu-bility are too great to be explained by colloidal conditions, andmust be due to polymerisation.E. C. C. BALY.69 F. Halla, Zcitrch. physikal. Chcm., 1914, 86, 496 ; A., ii, 178.7O A. Holt, Prx. Roy. Xoc., 1914, [ A ] . 90, 226; A., ii, 452.71 A. Sieverts, Zeitsch. physikal. Chem., 1914, 88, 103; A . , ii, 626.72 G. Wolf, ibid., 1914, 87, 575 ; A., ii, 517.A. Thiel and H. Gessner, Zeitsch. anorg. Chem., 1914, 86, 1 ; A., ii, 27

ISSN:0365-6217    

DOI:10.1039/AR9141100034

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART I.-ALIPHATIC DIVISION.THE fact that a- considerable proportion of the original literaturewas no longer available during the second half of the past yearhas had comparatively little effect on the compilation of thissection of the Annual Report. The tot,al number of papers re-viewed has been about the average, and the quality of the workdescribed has been well maintained, but, for obvious reasons, verylittle progress has been made in some of the new developmentswhich were described last year. Nevertheless, many importantadvances have been made on systematic lines, although, in somebranches of the subject, a number of novel results have beendescribed, which are isolated observations, and therefore unsuit-able for general discussion. Taking these factors into account,it has been considered advisable t o limit the number of topicsreviewed in the Report, and t o deal with these in somewhatgreater detail than is possible in normal circumstances.Optical Activity.The preparation of optically active compounds and the continua-tion of attempts to correlate rotatory power with constitution arestill being continued with unabated vigour, so that new facts andnew theories have rapidly accumulated during the past year.Asquantitative work on optical activity is naturally carried out oncompounds of simple type, the subject is one which may be appro-priately discussed under the general heading of aliphatic com-pounds. Considering the number of papers to be reviewed, atten-tion will be restricted in the following account to cases in whichactivity is dependent on the presence of ‘ I asymmetric carbonatoms ” only.I n the first place, attention may be directed to the satisfactorysolution of a problem of long standing.The question has oftenbeen raised as to the simplest possible type of organic compoundwhich should be capabIe of displaying optical activity, and664 ANKUAL REPORTS ON THE PROGRESS OF CHEMISTRY.it has now been shown that when a single carbon atom is unitedto three different elementary atoms and to an inorganic radicle, theresulting molecule can exist in active forms. The compound tofurnish this interesting result was chloroiodomethanesulphonic ... acid,c1I>C<&,H~and it is noteworthy that the activity, which was measured on theammonium salt, was not impaired by the action of the usualracemising agents.*Turning to another problem of fundamental importance, a mostinstructive transformation is reported by Fischer, who has, afterconsiderable difficulty, succeeded in interchanging two groupsattached to the same asymmetric carbon atom, so that an opticalinversion has now been established in which all the intermediatecompounds have been isolated.* d-isoPropylmalonamic acid was,in the first place, converted into the methyl ester, and the amino-group expelled by the action of nitrous acid.Thereafter, throughthe intermediate formation of the corresponding hydrazidic acid,the esteric methoxyl group was replaced by the amino-group, and,in this way, the desired interchange of two groups was completedwith the result, already indicated, that the Z-isomeride of theoriginal acid was formed.Inspection of the structural schemeillustrating this cycle of changes will show that the attachment ofthe four groups to the asymmetric carbon atom remains undisturbedduring the various reactions, and that a t no stage is any group,directly attached to the asymmetric atom, completely removed :H CO,H H CO,EI7 --C,H,>U<CO,MC? --+ C,H,>C<C'O.NH2-- -+ B.The change from A to B thus constitutes an inversion, as indi-cated by the looped arrow, a convenient expression which will befound useful in blackboard illustration.3Reference may, a t this stage, be made to another idea whichmay likewise be of service in teaching, and that is a revival of thesuggestion that racemisation, even in the case of acids, is merely aparticular case of tautomeric change, and is due to the oscillationof a labile hydrogen atom.* There is much to be said for thisM'.J. Pope and J. Read, T., 1914, 105, 811.E. Fischer and F. Brauns, Xitzungsber. K. Akad. Wiss. Berlin, 1914, 714 ;0. Rothe, Ber., 1914, 47, 843 ; A . , i, 538.A , , i, 942. * P. F. Frankland, T., 1913, 103, 741ORGANIC CHEMIS'I'KY. 65suggestion , particularly as the best defined examples of auto-racemisation occur in the case of compounds which are definitelytautonieric, but nevertheless an explanation of racemisation whichwould be perfectly general in its application is still t o be found.Several publications of the past year deal with the allocation ofdefinite configurations t o a number of aliphatic compounds.It is,of course, notorious that the vagaries of the Walden inversion muststill render uncertain speculations on configuration which are basedupon reactions involving substitution and replacement of groups.At the same time, an interesting series of transformations has re-sulted in the determination, with some degree of certainty, of theconfigurations to be assigned t o the active glyceric and lactic acids.5Starting with the amide of I-malic acid, t'he corresponding ainicacid was prepared and converted into I-isoserine,C02H*CH(OH)*CH,*NH,.From this, in turn, d-lactic and d-glyceric acids were obtained, theformer by a somewhat indirect process, and the claim is made thatthe respective configurations of the various compounds involvedmust be as represented below:p , HOH*F*Hyo2H 7*2H /+ CH,*OHd-Glyceric acid.CH2*C02H CH2*NH2OH*$I*H --+ OH*$!*Hyo,* Z-Malic acid.I-isoserine. 1 90H.y.HCJ%d-Lactic acid.These views can certainly be supported by a number of argu-ments, and the scheme of the research is ingenious, but, consideringthe nature and variety of the reagents involved, i t seems unlikelythat the transformations are entirely unaccompanied by changes inconfiguration.I n reviewing the numerous publications which have appearedduring the past twenty years regarding the relationship betweenconstitution and molecular rotation, one cannot fail to be impressedwith the great changes which have taken place in the experimentalmethods employed arid in the selection of suitable compounds forexamination.As a result of many patient investigations, duerecognition is now given in accurate work t o the effect of tempera-ture, concentration, the nature of the solvents used, dispersioneffects, and other important factors, whilst the attention now paidt o racemisation affords a better guarantee that optically pure com-K. Freudenberg, Ber., 1914, 47, 2027 ; A . , i, 924.REP.-VOL, XI. I66 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.pounds are used. Perhaps the most prominent feature of recentwork in this field is the large number of optically active compoundswhich have been examined, and the completeness with which homo-logous series of these cornpounds have been built up on systematiclines.The pages of the Journal bear striking testimony to thispoint in the consecutive investigations described by Pickard andEenyon. Obviously, work of this magnitude and detail can onlybe studied and appreciated by reference to the original papers, buta brief summary of the present position of the subject may begiven, as a number of definite advances have recently been made.I n the first place, i t should be mentioned that, in continuation ofhis previous work, Lowry has examined the magnetic rotatory dis-persion of a large number of organic compounds which, for themost part, are of simple type.6 It is found that, generally speak-ing, the values determined are remarkably constant in homologousseries.On the other hand, optical rotatory dispersion is morevariable,’ although, in the case of disubstituted carbinols of thealiphatic serim, the value becomes constant when, in a homologousseries, the fraction of the molecule in which the chain is lengthenedbecomes the heaviest part of the asymmetric system. Further, ithas been shown that the formula ct=k/(h2-A$), which can beapplied generally t o express the rotatory dispersion of organic com-pounds in the homogeneous state, is consistent with the valuesfound for active carbinols a t moderate temperatures, and in somecases a t all temperatures up to the boiling point of the liquids.8The fact that the rotatory dispersions of esters d o not conformuniformly to the above formula must be accepted as indicatingthat ethereal salts are, after all, more liable t o undergo intra-molecular changes than are the carbinols, and are thus less suitablefor the determination of true optical values.This idea is supported by a study of a series of active esters ofthe type CH3*CH(O*CO-R)-R’, which were prepared from thecorresponding active carbinols.9 The examination of numerousexamples of these esters has included the effect of temperature,change of concentration, the influence of solvents, and the deter-mination of the rotations in light of different wave-lengths.Themain conclusions drawn are: (1) alterations in rotatory powerobserved owing to change of temperature or the conditions of solu-tion, are due to alteration in the nature or complexity of the activemolecules, and (2) the anomalous dispersion exhibited by someT.M. Lowry, T., 1914, 105, 81.5 T. M. Lowr!, R. H. Picknrd, and J. Kenyon, ibid., 94.* R. H. Pickard and J. Krnyon, itid., 1115.Ibid., 830, 2262 ; J. Kenyon. ibid., 2226ORGANIC CHEMIS‘l’ltY. 67esters of apparently simple structure points t o the occurrence ofintramolecular changes in the .ester group. This supposed changeapparently cannot involve alteration in mass, and is probably dis-tinct from association or polymerisation. One suggestion offered isthat the ester group may, in common with the carboxyl group,react either asorthe proportion of each forni varying according t o the conditions,although the authors are careful to state that they obtained nodirect evidence indicating the presence of such isomerides in theesters examined by them.The results of this and other re-searches10 afford strong support t o the recent expansion of the ideathat anomalous dispersion is due t o the simultaneous presence oftwo interconvertible active compounds possessing different dis-persive powers.11Evidently a new feature of complexity must now be recognisedin quantitative investigations connected with optical activity.Optically pure liquids must be examined under conditions whenthey are actually homogeneous, and this, no doubt, will play aprominent part in the future development of this importantsubject.Considering the manif old difficulties which surround this problem,it is surprising to find that, even in compounds which containseveral asymmetric systems, some empirical quantitative generalisa-tions have been established.Among these may be mentionedHudson’s rule regarding molecular rotation in the sugar group.12Although this generalisation is based on principles which are notgenerally accepted, it has been shown to apply exactly in the caseof the a- and P-forms of monomethyl glucose.13 As these iso-merides showed suspended mutarotation, i t was possible to deter-mine the maximum optical values dii-ectly, the results obtainedbeing in agreement, within the limits of experimental error, withthe values calculated by Hudson’s method.It is possible that the whole subject of optical activity may, inthe near future, undergo startling changes, and much interest willbe taken in the results recently contributed by Erlenmeyer andhis collaborators on asymmetric syntheses effected by means ofThe well-known experiments quoted by asymmetric induction.”G.W. C!ough, T., 1914, 105, 49.11 H. E. Arrnstroiig and E. E. Walker, PTOC. Zhy. SOC., 1913, [ A ] , 88, 388 ; A.,1913, ii, 543.Ann. Xeport, 1909, 124 ; 1913, 79.13 J. c‘. Irvine and T. P. Hogg, T., 1914,105, 1386.F 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMJSTRY.Marckwald, in which active a-metliylbutyric acid was obtained bydecomposing the brucine hydrogen salt of inetliylethylmalonic acid,have been repeated under conditions which exclude the separationof the salt in fractions. The ultimate product obtained neverthe-less displayed optical activity, and this result is interpreted byErlenmeyer as a proof that two isomeric methylethylmalonic acidsexist, and that the formation of an active inethylbutyric acid isdue to induction.Further, & or Z-tartaric acid may take theplace of brucine in a parallel reaction, giving rise similarly to theZ- or d-form of methylbutyric acid.14 Results which are less easilyexplained have, in addition, been reported, as cinnamic acid issaid to have been obtained in d- and Z-forms by heating with theactive tartaric acids.15 According t o Erlenmeyer, cinnamic acidis to be regarded as C,H,*CHL-C'€IL*CO,H, where L representsan unoccupied valency power the existence of which permits of theformation of non-superimposable forms.Scrutiny of the experi-mental details leaves a certain amount' of doubt as t o whether theimportant claim has been justified that a compound devoid ofan asymmetric atom (or its equivalent) has actually been obtainedin active forms, or, a t all events, has been cause:!, to acquire opticalactivity. At the same time, the idea does not rest on the evidenceof a single example, as benzaldehyde has also been added to thelist of compounds which can be made to display induced activity.16The development of this work will doubtless be closely watched.Tau tomerism.Although in recent Reports considerable attention has beengiven to the consideration of tautomeric change, and the subjecthas also been reviewed in the latest Presidential Address,l7 it isdifficult to resist the temptation t o refer t o some new observationswhich seem worthy of mention.The suggestion that ozone will prove t o be a useful reagent inthe study of tautomerides has been considerably strengthened inthe course of the past year, and in an important paper18 a numberof fresh examples illustrating its efficiency are quoted.I n addi-tion, evidence has now been accumulated to show that ozone doesnot act catalytically in affecting the keto-enol change, and that itsreaction is confined strictly to enolic forms. Now that these pointshave been established, the method will doubtless be extensivelyl4 E. Erlenmeyer and F. Landsberger, Biochem. Zeitsch., 1914, 64, 366 ; A., i, 920.l6 E.Erlenmeyer, G. Hilgendorff, and F. Landsberger, ibid., 296 ; A . , i, 965.l6 Ibid., 382 ; A . , i, 967.l7 W. H. Perkin, jun., T., 1914, 105, 1176.l8 J. Scheiber and P. Herold, AnnaZen, 1914, 405, 295 ; A, i, 926ORGANIC CHEMISTRY. 69used, particularly as the experimental procedure appears to becomparatively simple. I n the paper referred to, the results quotedare for the most part perfectly normal and in agreement withthose arrived at by other methods, but one or two special casesare considered. Thus, the mixture of ozonides obtained fromoxalacetone gave, on decomposition, a variety of products thenature of which proves that the parent diketone exists in three un-saturated forms, two being mono-enolic and the third di-enolic :OH*CMe:C:C( ON)-CO,E t.COMe*CIX:C(OH)*CO,Et, O€I*C1Clle:CH*CO*CO,Et,111 view of this result, aiitl others of a siniilar nature, i t is notsurprising that the applicatioii of Meyer's volumetric method todiketones frequently gives figures poiiiting to an eiiol content ofnearly 100 per cent., and, in the case of oxalacetone, the resultis above this maximum.Nevertheless, Meyer's process continues to give valuable results,and, in some instances, adequate explanations have been fortli-coming to account for the discrepancies occasionally encouuteredin comparing the values obtained by this method with thoseindicated by purely physical processes. Thus, on redeterminingthe refractive indices of pure (ketonic) acetoacetic ester, and alsoof the equilibrium mixture,lg values have been obtained which arein agreement with the result, previously arrived a t by the titrationmethod. The conclusion is again drawn that, in the liquid state,the equilibrium mixture contains from 7 to 7.4 per cent.of theeiiolic form, and as this resuIt is considerably higher than thatquoted by Knorr, it is boldly suggested that the latter workerfailed to determine the refractive index of the keto-ester untili t had undergone partial enolisation.An interesting application of the bromine-titration process isindicated in a paper, where it is shown that. the desmotropicchanges exhibited by nitro-compounds can be followed quantita-tively, just as in the case o l keto-enols. Phenyldinitromethaneproved a specially suitable test substance in this respect, and asthe mi-form is more soluble than the true nitro-derivative, theeffect of water and the simple alcohols is the reverse of thatoccasioned with tautomeric ketones.20 Current ideas regarding thestructure of isonitro-compounds are, however, still somewhat un-settled.21The idea that, in the case of aldehydes, substitution by meansof halogens is preceded by a change comparable with the keto-enoll 9 I<.H. Meyer znd F. C. Willson, Bcr., 1914, 47, 837 ; A , , i, 483.2o K. H. Meyer and P. Wertlieiirier, ibiJ., 2374 ; A . , i, 1061.21 S. S. Xanietkin, J. Riw. Phys. G'hem. Soc., 1913, 45, 1414 ; A., 1913, i, 129770 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.transformation has been realised in the course of a dynamica.1study of the action of bromine or iodine! on acetaldehyde.22 Itwas found that, in the absence of acids, bromine acts entirely asan oxidising agent, but that oxidation and substitution proceedsimultaneously in strongly acid solutions.The fact that thevelocity of the reaction is independent of the concentration andnature of the halogen used may be accounted for on the supposi-tion that three distinct changes are involved, the first of whichis enolisation :CH,*CQH 0 --+ CH,:C<EH -> CH,X*CX<gH + CH,X*C<E<Y A < / \ /Y Enolisation. Addition. Loss of halogen hydride.It may be mentioned that, according to, the most recent views,23the formation of iodoform from acetaldehyde is another reactionthat proceeds only with the eriolic form, and i t will be interestingto observe how far the tendency of aldehydes to react in thismanner is of general application.Hydrocarbons.With the exception of investigations on the mechanism of com-bustion, few.publications of the past year have dealt with thechemistry of saturated hydrocarbons. At the present time, mostresearches on unsaturated hydrocarbons lead ultimately to thecaoutchouc problem, with the result that it is often a matter ofsome difficulty t o disentangle from the mass of published workresults which are of general interest and importance. Severalrecent papers have, however, dealt with the formation of poly-merides from hydrocarbons, and a number of fresh contributionshave been made to this long-standing problem.As an example of such work, attention may be directed to acareful study of tetramethylallene, CMe,:C:CMe,, which appearsto have been obtained pure for the first time.24 It is shown thaton polymerisation under the simplest possible conditions the hydro-carbon is converted almost completely into the dimeride, the sbruc-ture of which, in view of its optical properties, is probablyCMe,*$!:CMe2 ICMe2-C:CMe2'On the other hand, more drastic methods result in the forma-tion of acetylenic derivatives, such as CHMe,-CHMe*Ci CH, andthe alteration thus occasioned in the carbon chain points to a con-z2 H.M. DBWSOII, D. Burton, and H. Ark, T., 1914, 105, 1275.28 A. Pieroni slid E. Tonnioli, Gazzetta, 1913, 43, ii, 620 ; A ., i, 6.24 B. K. blereshkovski, J. Ricss. Phys. Chem. SOC., 1913, 45, 1940; A , , i, 369ORGBNlC CHEMISTRY. 71siderable tension in the structure CR,:C:CR,. A general prin-ciple seems to be involved here, as comparison of the velocities ofpolymerisation of allene, di-, tri-, and t,etra-methylallene, provesthat the stability of the compounds diminishes steadily with in-creasing substitution.25 The limiting case is thus reached in tetra-methylallene, where all the replaceable hydrogen atoms aresubstituted by alkyl groups.Halogen derivatives of acetylene are now being used extensively,and in another section of the Report reference is made to asynthetical method of preparing unsaturated glycols which dependson the use of magnesium acetylene haloids.26 Two types of suchreagents are available, namely, CII iC*MgX and MgX-CIC*MgX,and the former, on reaction with ketones, give rise to unsaturatedtertiary alcohols. A greater range of reactions is afforded by theuse of dimagnesium acetylene dibromide, which, naturally, reactswith ketones and aldehydes to give ditertiary y-glycols and di-secondary y-glycols respectJvely.27 As a side-issue of the generalscheme of research, it may be remarked that the results of thisseries of investigations point conclusively to the symmetrical struc-ture for the halogen derivatives of acetylene.2* This point wasreferred to last year, when it was shown that Nef's views as tothe structure of these derivatives were open to criticism.Caoutchouc.--As was t o be expected, the list of patented pro-cesses for the preparation and polymerisation of hydrocarbonsrelated to caoutchouc bas been materially increased during thepast year.The methods employed continue to show greatdiversity, and there is a natural tendency to range far and widein search of polymerising catalysts, but, apart from this aspect ofthe general problem, i t is evident that our ideas regarding thestructure of the caoutchouc complex must, in the meantime, remainsomewhat less decided than was the case a year ago. Before deal-ing with new experimental facts, mention may perhaps be madeof an interesting historical account of the earlier work on thesynthesis of caoutchouc which will be useful in teaching, providedless prominence is given t o the controversial aspects of the~ubject.~QAs is well known, the claim made by Harries that the caout-choucs prepared from isoprene, by ,autopolymerisation, or by theaction of acetic acid, are identical with each other and with the"5 S.V. Lebedev and B. R. Mereshkovski, J. Bass. Phys. Chcm. SOC., 1913, 45,a6 5. I. Iooitsch, ibid., 1902, 34, 239 ; ' 4 . , i, 393.17 Ibid., 242 ; A . , i, 405.29 F. J. Poiid, J. Amer, C'hem. SOC., 1914, 36, 165 ; A., i, 194.1249 ; A . , 1513, i, 1285.Ibid., 1904, 36, 1545 ; A., i, 37372 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.natural product, depends on the identity OF the respective ozonides.A similar comparison of the caoutchoucs derived from isoprene bythe action of sodiuin o r of peroxides leads, however, to the con-clusion that in each case the products are non-honiogeneou~.~~From the fact that the ozonides thus obtained decompose to givesuccinic acid, acetonylacetone, lzvulinaldehyde, and lzevulic acid, itis deduced that the caoutchoucs must contain, not ollly1 : 5-dimethyl-Al ::’-cyclo-octadiene, but also the corresponding1 : 6-dimethyl isomeride :1 $JH,*CMe:CH.$JH,C H, C 31 e : CH CIS, 2’I n order to explain this result, it is suggested that the differentpolymerides arise, respectively, from the symmetrical and the un-symmetrical condensation of two molecules of isoprene.The state-ment is also made that the caoutchouc prepared by autopolymerisa-tion of isoprene is likewise’ a mixture, and is similar t o “sodiumcao~tchouc,~~ in contrast t o which the natural product is derivedentirely from 1 : 5-dimethyl-A1 :5-cycZo-octadiene.According to theresults of this research, the whole question of the identity or non-identity (and also of the uniformity) of artificial and naturalcaoutchoucs is once more thrown open. To this Harries has re-plied, admitting the irregularity with which the polymerisation ofisoprene proceeds, but suggesting that the source of the above con-flicting results may be traced to the presence of impurities in theisoprene used by Steimmig.31 The suggestion has been followed bywhat might, with advantage, have preceded this discussion, namely,a redetermination and standardisation of the physical constants ofthe parent hydrocarbon.32 It may, in passing, be noted that thevalues now quoted for the density and refractive index of isopreneare in fair agreement with those obtained by other workers.33It is necessary to state that the most direct evidence in favourof the idea that the caoutchouc complex consists of an aggregateof eight carbon rings has now been withdrawn.34 As explained inlast year’s Report, it is possible to degrade a “regenerated caout-chouc ” by conversion into the ozonide, and treatment of the latterwith water.The diketone thus obtained as the essential productwas then considered t o be cyclo-octane-1 : 5-dione7 but repetition ofthe work on a larger scale has shown that such is not the case.The degradation, in fact, results in the formation of heptane-P<-30 G.Steimmig, Ber., 1914, 47, 350 ; A . , i, 307.31 C. Harries, ibid., 573 ; A , , i, 422.9’L Ibid., 1999 ; A . , i, 917.y4 C. Harries, B e y . , 1914, 47, 784 ; A., i, 386.S. V. Leberlev and B. K. Mereshkovski, Zoc. citORGANIC CHEMISTRY. 73dione, CH,-CO* [CH,],*CO*C)H,, which readily undergoes dehydra-tion, and this alteration in composition leads to a fortuitous agree-ment with the analytical figures required for C8H,,0,. Of thenature and identity of this diketone there can be no further doubt,as the same compound has been obtained in the course of entirelydifferent work by the oxidation of heptan-<-01-P-one by chromicacid.35Although thus deprived of what appeared t o be a most con-vincing experimental proof, the idea that caoutchouc is derivedfrom an eight-membered ring is still strongly supported by othcrresults.A t the same time, somewhat different views are expressedin the course of an elaborate research36 in which the mechanismof polymerisation in olefi ne hydrocarbons is discussed. The generaliiiethod adopted in the research now under review was t ostudy the two dimerides of isoprene, and of related hydrocarbons,as a first stage in the more complex polymerisation. The resultsobtained leave the impression that rigid views on the whole ques-tion are not yet justified.Acids and Related Compounds.As the acids of the aliphatic series have in the past been thesubject of prolonged and careful investigation, it is not surprisingto find that a stage has now been reached when few discoveries offar-reaching importance have t o be recorded. Nuch of the re-search now being done on the simple aliphatic acids has a directphysical bearing, and, as a result, improved methods of purifica-tion and revised physical constants are frequently reported in theliter a ture.Another type of physico-chemical research, in which aliphaticacids are involved, may be mentioned a t this stage, as, although thesubject is still incompletely developed, i t will, no doubt, be followedwith much interest.The general inquiry as to the nature of soapsolutions has been specially prominent of late, and some results ofan unexpected nature have now been established. For example, theconductivities of thO potassium salts of fatty acids have been deter-mined for all compounds, with an even number of carbon atoms,from acetic acid up to stearic acid.37 The values found are notablyhigh, and, taken in conjunction with previous work on this sub-ject, i t is evident that high conductivity is a general feature ofthese salts even when the solutions approach the colloidal con-dition.Moreover, a determination of the degree of hydrolysis and35 1%. G. Farglier and W. H. Peikin, juii., T'., 1914, 105, 1353..'G 9. Y. Lebedev and B. li. Mereshkovski, Zoa. c i t .13. M. Bunbury an11 H. E. Martin, T., 1914, 105, 41774 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the true alkalinity of map solutions shows that the amount offree alkali present in such systems is insufficient to account forthe conductivity vaIues.38 I n order to explain the behaviour ofthese solutions as electrolytes, the suggestion is made that thismay be due to the presence of highly charged aggregates whichare not ions in the ordinary sense of the term, but for which theexpression " colloidal ion " might reasonably be applied.Work ofthis nature offers many possibilities for theoretical expansion, butmust present many experimental difficulties.There is no other problem connected with unsubstituted mono-basic acids which calls for special attention, but, on the otherhand, the succinic acid series continues t o prove an attractivefield of inquiry. For a considerable time it has been evidentthat the analogy between phthalyl chloride and succinylchloride is not well maintained, and that, generally speaking, thereactions of the latter compound are by no means in agreementwith an unsymmetrical cyclic structure.The action of ammoniaon the acid chloride certainly gives very small yields of succin-amide, but i t is now shown that, in the reaction with methyl-amine, the symmetrical product is formed to the extent of 25 percent., and ultimately, in the case of aniline, ths reaction of asimilar type is quantitative.39 I n all probability, the differentresult obtained in thme reactions is due to the superior effect ofammonia in removing the elements of hydrogen chloride from theint'ermediate compounds formed in each case. This is illustratedin the original paper by means of a structural scheme which dis-penses with the necessity of modifying the symmetrical formulafor succinyl chloride.The adoption of a similar scheme wouldserve to explain the observation4O that succinyl chloride, in its re-action with zinc alkyl iodides, gives rise only to products of the>o. c €3,--COCH,*CR,lactonic type, IOn the whole, the accumulated evidence to which reference wasmade in last year's Report is in favour of the normal formula forthe chlorides of all acids of the succinic type. Certainly in thecase of d-dimethoxysuccinyl chloride the optical behaviour of thecompound indicates that it possesses an open-chain structure, andthat, even under the influence of powerful catalysts, it shows notendency to undergo tautomeric change into a lactonic modifica-tion.41 An additional example which emphasises this distinction* J.W. 1lcB;sin and H. E. Nartin, T., 1914, 105, 957.39 G. F. blorrell, ibid., 1733.40 E. F,. Blake, Compt. rend., 1914, 158, 504 ; A , , i, 384.41 T. Purdieand C. R. Young, T., 1910, 97, 1524ORGANIC CHEMISTRY. 75between phthalyl and succinyl derivatives is furnished by a st,udyof the optically active anilic acids and anils obtained fromd-dimethoxy- and d-diethoxy-succinic acids re~pectively.~? No iso-anils were isolated, and as the activity of dimethoxysuccinaail wasnot affected by reagents which usually induce intramolecularchaiiges, the conc!usion may reasonably be drawn that the com-pound is a definite chemical individual. I n the same paper i t isalso suggested, on theoretical grounds, that Auwers’ views as tothe configuration of the s-dialkylsuccinic acids require alteration,and that the racemic modifications are not the compounds ofhigher, but of lower, melting point.This idea has been confirmedexperimentally, as it has been shown that whereas the dimethyl-succinic acid melting a t 1 9 5 O is irresolvable, the isomeride oflower melting point (127O) is the racemic form, and may beresolved by the agency of triethylenediaminecobaltic bromide.43This result furnishes, incidentally, an example of the somewhatunexpected application of active cobaltammines iil resolutions, andalso indicates the caution which must be exercised in allocatingmeso- and racemic configurations on the basis of melting-poiiitcomparisons.It has long been recogniszd that the replacement of hydrogenatoms by alkyl groups imposes restrictions on many reactions ofderivatives of succinic acid, and this is particularly noticeable inthe formation of aniides from esters.An extreme case is illus-trated by the fact that whereas methyl succinate readily givesan 80 per cent. yield of succinamide, a parallel reaction withmethyl cis-a/3-dimethylsuccinate proceeds with difficulty, andgives only 2 per cent. of the corresponding amide.41 It will beseen that this result is in agreement with Fischer’s view that’ thefirst action of ammonia on an ester is the formation of an un-saturated salt, and lends support to his prediction that a tetra-nietliylsuccinic ester would, in consequence, fail to react withammonia.Meth?/lcarbonato-acids.--Tlie methylcarbonato-derivatives ofhydroxy-acids are evidently of special value in syntheses where itis necessary to exclude the hydroxyl group from reaction, andseveral examples of their use in this respect have recently beendescribed. The characterisation of simple types of these com-pounds is, however, somewhat imperfect, and a detailed accountof metliylcarbonatoacetic acid will be welcomed.45 The acid isreadily acted on by thionyl chloride to give methylcarbonatoacetyl42 C.R Young, T., 1914, 105, 1228.43 A. Werner and M. Basyrin, Ber., 1913, 46, 3229; A., 1913, i, 1302.44 CT. F. Morrell, T., 1914, 105, 2698.45 E. Fischer and H. 0. L. Fischer, Ber., 1914, 47, 768 ; A., i , 38176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.chloride (I), from w.hich the corresponding methylanilide (11) iseasily obtained :COCl*C'H,*O*CO,Me -+- NMePh*CO*CH,*O-CO2Me.As was to be expected, the successive action of sodium hydroxideand hydrochloric acid on the latter compound resulted in theformation of the methyladide of glycollic acid.I n anothercharacteristic change, methylcarbonatoacetyl chloride was broughtinto reaction with benzene in the presence of aluminium chloride,and, on acidification of the solution, methylcarbonatobenzoyl-carbinol, COPh*CH,*O*CO,Me, was produced. From this, in turn,by the action of alkali, the carbomethoxy-group was expelled, withthe formation of benzoylcarbinol. Similar reactions have beencarried out on the a-methylcarbonatopropionic acid derived fromlact'ic acid, and consideration of the whole series of changes givesthe impression that this new method of temporarily masking thereactive hydroxyl group is extremely important. The use ofacetyl derivatives for the purpose mentioned above is lessefficacious, as, in addition to the ease with which the sub-stituting - groups are removed by hydrolytic reagents, the tendencyof these compounds to lose acetic acid is frequently very great.Occasionally this inst ability leads to interesting results, as, forexample, in the conversion of diacetyltartaric anhydride intocarbon s u b ~ x i d e .~ ~ Apparently this reaction involves the elimina-tion of two molecules of acetic acid, thus giving rise to acetylene-dicarboxylic anhydride, which, in turn, is converted into carbonsuboxide through the intermediate formation of P-oxypropiolo-lactone :(1.) (11.)AcO*C'H*COA ~ O ~ H - C O c*co c*coEsters.-As most of the synthetical work involving the use ofesters is described under various other headings, there is littlenecessity t o devote a special section to these compounds, particn-larly as few novel or unusual results have been noted in the periodunder review.Esters still find manif old applications in condensa-tion reactions, their halogen derivatives are usefully employed insyntheses involving organo-metallic compounds, and, as in the past,they have been the subject of careful physical examination.Attention may be drawn t o a st'udy of the hydrolysis of methylacetate in which hydrogen chloride, in widely varying concentra-tion, was used as a catalyst.47 I n this specific case i t has beenfound that there is no tendency for the temperature-coefficient of46 E.Ott, Ber., 1914, 47, 2385; A . , i, 1048.47 A. Lainble and V7. 0. M. Lewis, Y'., 1914, 105, 2330ORGANIC CHEMISTRY. 7 7;L strongly catalysed reaction to be less than that of a weaklycatalysed reaction. Evidently, if tlie effect of a catalyst is merelyto increase the ratio of active to unactivated molecules, thetemperature-coefficient should diminish when the number of activemolecules is increased. The results of this investigation certainlylend support to the views expressed by Marcelin that the effect oftemperature in accelerating reactions depends on an increase inthe internal energy of the reacting molecules, and does not involveany distinction between active and inactive molecules. Thetheoretical discussion is extended t o a consideration of catalysis asa radiation effect, and thus falls within the compass of anothersection of the Reports.Lactones.-Probably the most comprehensive study of simplelactones which is to be reported is described by Nef in connexionwith the examination of acids allied to the sugars.This is, how-ever, dealt with later under carbohydrates, and, in the meantime,attention may be directed t o various extensions of earlier work onthe reactions of P-lactones.As a rule, complex changes ensue when a P-lactone is heated,and the formation of ketens in such reactions has been traced inan examination 48 of the decomposition undergone by the esters ofcertain lactonic acids.By the interaction of methyl iodide andthe /3-lactone of silver /3-liydroxyisopropylmalonate, the esterobtained is, curiously enough, not a derivative of the parent acid,but of the P-lactone of /3-hydroxy-u-methylisopropylmalonic acid :$)-QMe2 ?-9Me,C 0- CH C0,Ag --+ C O ~ C M ~ * C O ~ M ~This irregular reaction resembles in many ways the action of alkyliodides on the silver salts of hydroxy-acids, where, in addition t othe normal ester, the corresponding alkyloxy-ester is invariablyformed to some extent. The ester formulated above is remark-ably stable,, but is decomposed when heated in an inert atmo-sphere to give a notable yield of dimethylketen, together withacetone and carbon dioxide :0-CMe,... I I i.......-~.-.~..--.._.___._._..... ._ -+ Me2CO-t CO, + Me,C:CO. ~ : o * u M ~ & o , ~ ~ M ~ IThe reaction appears t o involve molecular rupture in the manherindicated by the dotted lines, followed by the transference of amethyl group to the keten residue, and, although this may appeara somewhat empirical explanation of the change, it is supportedby the fact that bromomethylketen, CBrMe:CO, has been obtainedin a parallel reaction from the corresponding a-bromo-lactonic ester.48 E. Ott, Annnlea, 1913, 401, 159 ; A., 1913, i, 130278 AKNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A Zdel~ydes and Ketones.-The preparation of aldehydes andketones by methods depending on catalytic agency still continuesto be prominent, but there is little under this heading t o add t othe account given in 1913, except that manganons oxide has bee11used with considerable success as a catalyst in thesc r e a ~ t i o n s .~ ~The reagent is claimed to possess several advantages over titanicoxide in this type of reaction, and is possibly more uniform in itseffect than thorium oxide, which sometimes gives irregular results.During the past few years, the preparation and study of unstablealdehydes have been greatly extended, and a new syntheticalmethod for the preparation of certain types of such compounds hast o be ncted. As is well known, the methods hitherto in use forthe preparation of glyoxals are n o t only experimentally difficult,but are frequently uncert'ain in their results.The following seriesof reactions, however, appear to be general in their application,and to proceed smoothly.50Ethyl diethoxyacetate may be condensed with ethyl acetate bythe agency of sodium:CH(OEt).2* C0,Et + CH( OEt),*CO*CH,*CO,Et.The product (or its homologues) is then hydrolysed by dilute acids,giving, in the first instance, an acetal, and finally the correspond-ing alkylglyoxal, CH(OEt),*CO*R ++ CH0.CO.R. The proper-ties of a number of new glyoxals are now described, and, in future,these compounds will be more readily available. It is significantthat most of the new representatives display the yellow-green colourwhich appears to be characteristic of all true glyoxals.As wasto be expected, the compounds are readily converted into thecorresponding hydroxy-acids, and it is to be noted that the enzyme,glyoxalase, effects the same change, but gives optically active pro-ducts. This is an important observation, the significance of whichwill be obvious.The preparation of aldehydes by direct oxidation of the corre-sponding alcohol is generally a difficult operation, and in this con-nexion it is well to draw attention to a paper in which the pre-paration of pure glyceraldehyde from glycerol is described.51 Theoxidation was effected by means of Fenton's reagent, and the pro-duct, isolated through the intermediate f ormation of the diethyl-acetal, was obtained in the crystalline state.These reactions have,of course, already been carried out, but the special feature of thepaper, which should be consulted by those who have occasion toemploy hydrogen peroxide in similar reactions, is the precise ex-49 P. Sabatier and A. Mailhr, Cornpl. rend., 1914, 158, 830 ; A , , i, 547.50 H. D. Dakin and H. W. Dudley, T., 1914, 105, 2453.51 E. J. Witzemann, J. Amer. Chena. SOC., 1914, 36, 2223 ; A., i, 1165ORGANIC CHEMISTRY. 79perimental conditions which are established, both for the use ofFenton’s reagent and for the production of acetals.Polyhyclric Alcohols and their Derivatives.Few methods for effecting the apparently simple change ofa dibromo-compound of the type of ethylene dibromide into thecorresponding glycol are satisfactory so far as yields are con-cerned.Even the preliminary conversion of the halogen com-pounds into acetates is, in many cases, no more effective than thedirect process, and unsaturated derivatives of the type of vinylbromide are frequently formed, according to the schemeCR2Br*CHRBr -+ CR,:CRBr.It has been shown in a careful study of this process that the useof silver acetate as a reagent for decomposing dibromides is lessopen to objection in this respect than is that of potassium acetate.62Further, the ease with which diacetates are formed from dibromidesis less in higher than in lower homologues, and is diminished whenthe two bromine atoms are in spatial proximity. This a p e s withthe experience of other workers who have been engaged on similartopics, and a number of striking experimental facts are recordedby Franke,53 who has shown that dibromides of the typeCH2Br*CRR’*CH2Brare notably stable towards both potassium cyanide and silveracetate.On the other hand, the above reagents react readily withdibromides constituted according to the formulaCR2Br* CH2*CR2Br,and the suggestion is made that the reaction takes place in twostages, involving : (1) the formation of an unsaturated derivative,and (2) the addition of hydrogen cyanide or acetic acid. Both thepapers now quoted may be consulted with advantage by all whoare engaged with work involving dibromides, which can only beobtained in small quantity, and the suggeetion that sodiumethoxide in dilute alcoholic solution is the most effective reagentfor the hydrolysis of diacetates will doubtless find many appli-cations .Acetylenic glycols offer many possibilities for attractive research,and a representative series of these compounds has been preparedduring the past ten years through the agency of magnesium-acetylene derivatives.A simple example may be quoted in illus-tration of the pr0cess.5~ Dimagnesium acetylene dibrornide reactswith acetaldehyde to give the additive compound,MgBr*O*CHMe*CiC*CHMe*O*NgBr,52 E. G. Bainbridge, T., 1914, 105, 2291.53 A. Franke, Monalsh , 1913, 34, 1893 ; A., i, 7.54 S . I. Iocitsch, J. Russ. Phys. Chern. Sac., 1903, 35, 430 ; A . , i, 37580 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.from which, on decomposition with water, the corresponding un-saturated glycol, O€I*CHMe*CiC-CHMe*OH, is produced.Thereaction, which is applicable t o substituted aldehydes and also toaliphatic or cyclic ketones,55 seems perfectly general, and has beenapplied to a large number of cases. Norw that improved methodsfor tlie preparation of unsaturated glycols are available, the ex-amination of these compounds is being carried out in considerabledetail. 56Glycerol.-When critical research is brought t o bear on reactionsfamiliar t o the lecture-room or laboratory, the result is frequentlyt o unfold new difficulties and t o complicate the task of teacher andstudent alike. The opposite result, and the reduction of importantreactions to simple terms, is thus doubly welcome.The interaction of glycerol and oxalic acid under varying con-ditions has now received a new interpretation, which will be gener-ally accepted.57 Both an acid and a normal oxalate are produced,and the decomposition of these esters gives rise t o all the knownproducts of the reaction.I n the following structural outline,which illustrates most of the changes involved, the double arrowsindicate the stages in which oxalic acid plays a part in the reaction,but the original paper should be consulted for the evidence uponwhich the scheme is based:Glycerol.FH,*O*CO*CO,H YH2*0*C3*H 7 H2*O*CO*C0,HFH*OH -+ YH*OH +GO, I$ ?H*OI-I +H*CO,HCH2*OH CH,*OH CH,*OHAcid oxalate. Monoformin.ICH +2CO,CH,*OH \ 7H2*O*70 SH2Normal oxalate. ' '-.. ~IT--O*CO -+ QH +3C02CH, 0.CO C0,H CH,*O*CO-HAlly1 formate.65 S. I. Iocitsch, J. Ruas. Phys. Chcm. SOC., 1906, 38, 656 ; A . , i, 375.56 R. Lespieau, Compt. rend., 1914, 158, 707 ; A . , i, 476; G. Dupont, ibicJ., 714 ;57 I?. D. Chattaway, T., 1914, 105, 151.A., i, 530ORGANIC CHEMISTRY. 81I n last year's Report, reference was made to one aspect of thecontroversy, which has been maintained for many years, as t o thenature and constitution of tlie glycerylphosphates, and the opinioiiwas expressed that the probleni should be attacked by entirelydifferent methods. During the current year an important paper 58has appeared, in which the cognate literature since 1903 is care-fully reviewed, and, in addition, the fresh experimental facts re-corded have cleared up a number of doubtful points.The simplestpossible glycerylphosphoric acid should exist in two forms,YH,* 0 PO( OH), FH2*OHFH*OH iLtl(f FH*O*PO(OH),CH,*OH CH,*OR(1. ) (11.1and only the a-isomeride should be capable of resolution into activemodifications. Previous attempts t o synthesise the isomerides in astate of purity have only been partly successful, as the tendencyof these esters to form polyglyceryl derivatives is very great. Eventlie identification of the glycerylpliosphoric acid obtained by thehydrolysis of lecithin as an active modification corresponding withformula I is still doubtful. It, has now been shown that theaction of phosphoryl chloride on a-dichlorohydrin is somewhat lesscomplex than was a t one time imagined. The product undergoeshydrolysis in two stages, giving, in succession, bis-s-dichloroiso-propylphosphoric acid and p-glycerylphosphoric acid.As calciumhydroxide and sodium carbonate were employed as the hydrolyticagents, the compounds actually isolated had the followingstructure :(a-Form . ) (B- Form. )CH2C!1 0 CH2C1 CH,*OH(:H.o--Y-o~H -+ C'H-O*PO(ONa), .AH,Cl h? bH,CI UH,.OHThe sodium P-glycerylphosphate proved to be identical with thecompound formed by the interaction of monosodium phosphate andtwo molecules of glycerol, followed by hydrolysis of the resultingdiglyceryl ester.For the preparation of the corresponding a-glycerylphosphoricacid, a new and apparently simpler process was devised in thata-nionochlorohydrin was found t o react readily with trisodiuinphosphate, and from the products of this reaction salts of a definitea-glycerylphosphoric acid were obtained :I I1 IIHO*CH,=CH(OH)*CH,CI + (NaO),PO -+HO*CH,-CH(OH) *CH,*O*PO(ONa),.58 H.King and F. L. Pyman, T., 1914, 105, 1238.REP.-VOL. XI. 82 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Those who have worked in this field will realise the experimentaldifficulties involved, and the advance which has been made, in thischaracterisation of the simplest types of glycerylphosphates.As pointed out last year, considerable attention is now beingdevoted to the study of glycerol derivatives in which the hydroxylgroups are only partly substituted, or are replaced by differentacyl residues. Numerous papers have since appeared which pointto the continuation of this development, and reference may bemade to the attempts, so far unsuccessful, to synthesis0 opticallyactive glycerides of a special type.59 A glyceride of the generalstructure OR*CH,*CH(OR’)*~~2901t2, where R and R2 representdifferent acyl residues and R’ may consist of an acyl group orhydrogen, should exist in active forms, the asymmetry beingdependent on the glycerol component of the molecule.Compoundsof this description should not only be of considerable physiologicalinterest, but might be of service in the study of lipolytic ferments,and thus lead to the identification of the specific enzymes re-sponsible for the degradation of fats in definite stages. Althoughthe research has not, in the meantime, given many positive results,the work has incidentally furnished a description of a number ofoptically active halogen hydrins.For example, Py-dibromopropyl-amine was resolved by d-tartaric acid and converted into the corre-sponding active bromohydrins by the action of nitrous acid. Inany circumstances, the replacement of both bromine atoms by acylgroups would not be likely to proceed smoothly, and the ease withwhich the active bromohydrins are racemised has, so far, limitedthe development of the research, although the fact that the d- andZ-epibromohydrins seem somewhat more stable leads to the hopethat the original object of the work will be achieved.As in the sugar group, the problems affecting the chemistry offats are now being attacked by two distinct methods.I n the onecase, ordinary synthetical or analytical reagents are employed,whilst in the other the synthetic or hydrolytic functions of enzymesare brought to bear. I n this connexion, many features of primaryimportance are indicated in the results of experiments in whichthe synthetic and hydrolytic effects of lipase are compared.Go Boththe rate and extent of the hydrolysis of triolein by means of lipaseare retarded as the amount of water present is increased, and thesame holds true f o r the synthesis of the triglyceride. The factorscontributing to this result differ, however, according as the changeis hydrolytic or synthetic. I n t7he former case, the water preventscontact between the enzyme and the oil, whilst during the synthetic59 E.Abderhalden and E. Eichmald, Be?-.) 1914, 47, 1856 ; A., i, 801.6o R. E. Armstrong and H. W. Gosney, Proc. Roy. Suc., 1914, [B], 88, 176 ;A . , i, 1149ORGANIC CHEMISTRY. 83reaction the water acts directly by removing glycerol in solution.The important observation is made that not only does the hpdro-lysis of triolein by lipase proceed in definite stages, giving a cli-and mono-glyceride, but that the synthetic action likewise shows atendency to be arrested a t a stage when the diglyceride constitutesthe main product.With the exception of investigations connected with biochemicalproblems, comparatively few researches have been concerned withpolyhydric alcohols higher than glycerol. The detailed chemistryof these compounds is, however, by no means exhausted, and muchwork remains to be done in this field.Considering the importanceof compounds allied to sugars which contain a methyl group i nthe terminal position of the carbon chain, the synthesis of a methyltetritol61 will be recognised as a step in the direction of arrivinga t the configuration of the methyl tetroses and pentoses. The com-pound in question was isolated, together w i d the correspondingaldose, by the reduction of dihydroxyvalerolactone. It may beremarked that although the configuration of active polyhydricalcohols is generally established by their relationship to the sugars,i t is possible to obtain the necessary evidence by another method.The condensation of polyhydric alcohols with acetone gives rise toisopropylidene derivatives, the stability of which is dependent onthe configuration of the hydroxyl groups F o r example,i t is possible by carefully regulated hydrolysis t o remove the threeacetone residues from tri-isopropylidenemannitol in definite stages,and by means of a somewhat complex experimental treatment it ispossible to make this result the basis for the allocation to mannitolof the following configuration :OH H H OH OH OHI I I I I IH.C--C--C--- C-C---OHIH d H d H h I!€ €!CIt will be remarked that, in the above structure, definite posi-tions are ascribed to the terminal primary hydroxyl groups, andthere seems every reason to believe that the idea is not onlyjustified, but furnishes an explanation f o r many of the irregularreactions of active alcohols of this type.Thus, to select one illus-tration, it has been shown that mannitol is only capable of formingpenta-ether~,~~ and that it is impossible to extend the alkylationt o one of the terminal hydroxyl groups. This pronounced sterichindrance is consistent with the idea that in mannitol there arethree hydroxyl groups in close spatial proximity.61 R. Gilmour, T., 1914, 105, 73.J. C. Irvitio and Miss B. M. Paterson, ibirl., 898. 63 Ibid., 91584 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Curb ohydrut cs.The progress made during the year in the study of the simplercarbohydrates has, in many respects, been remarkable, and, in allprobability, will lead to future developments of the utmost import-ance.I n the course of the past ten years the adoption of they-oxidic formula f o r reducing sugars and their glucosidic derivativeshas practically become universal, and there is thus a certain dangerthat, by blind adherence to its use, restrictions may be placedbotlh on synthetical methods and on legitimate speculations as t ostructure. This danger may be avoided if sufficient attention ispaid t o some recent publications,As is well known, Nef has been engaged for many years instudying the effect of simple oxidising media on carbohydrates, andthis inquiry has involved a re-investigation of an old problem-thechanges undergone by reducing sugars in the presence of alkalis.Following the usual method adopted by this author, publicationhas been delayed until the results of several independent investiga-tions were complete, so that it is now possible to view the resultsas a whole.The method has much to commend it, but leaves thereviewer faced with the difficulty of describing, within a limitedcompass, a large field of important work and a mass of experi-mental results. The original paper 64 should therefore be con-sulted, as it is manifestly impossible t o give more than an outlineof the research and to indicate its relationship t'o other work.When an aqueous solution of a hexose is allowed to remain incontact with dilute alkaris, profound changes ensue, and finally anequilibrium is established between the various enolic forms deriv-able from the parent sugar.The enolisation, and consequently thenumber of possible products, is diminished when the concentrationof the alkaline hydroxide is reduced, but in its fundamental prin-ciples t~he reaction is general, although complicated by the forma-tion of resins and polysaccharides. The unsaturated moleculeswhich are formed show a tendency t o undergo fission a t the doublebond, so that, taking glucose as a type, the following productsresult:From glucose aP-dienol+ formaldehyde and arabinose.From glucose Py-dienol+ diose and triose.From glucose y&dienol+ glyceraldehyde.The action of mild oxidising agents on mixtures such as thatdescribed above results in independent oxidation of the coni-ponents with the formation of carbon dioxide, formic and oxalicacids, together with a series of hydroxy-acids.The identificationts J. U. Nef, Annalen, 1914, 403, 204; A., i, 490ORGANIC CHEMISTRY. 85of the latter compounds necessitated their separate preparation,the re-determination of their physical constants, and a study of theconditions under which Obey are converted into lactones. Theresults are somewhat unexpected. d-Mannonic acid, for example,is easily converted into d-mannono-p-lactone,OH CH,* [ C H*OH ],*CH*CH( OH) COwhich rapidly undergoes spontaneous conversion into the parentacid in aqueous solution. The compound thus differs sharply fromthe correspoiidirig y-lactone, which is comparatively stable. Simi-larly, gluconic acid yields both a P- and a y-lactone, and thegeneralisation is claimed that hydroxy-acids corresponding with theformula C,,H,,O,,+ yield both bimolecular a-lactones and uni-molecular p- and y-lactones.It may be remarked that the proper-ties of the alkylated mannonic acids lend no support to the ideathat a-lactones are readily formed.65 Thus, of the two substitutedmaiinonic acids indicated below, only that with the constitutionexpressed by formula I forms a lactone, whilst the remainingisomeride could not be converted into any such derivative:I-.-,-.- IOM~*CH,*CH(O&~~)*CH(OH)*[CH*OM~Y]~*CO~H(1.)OMe*CH,*[CH*OMe],*CH(OH) *CO,H.(1 1.1Although the combined experimental results obtained by Nef areobviously of great importance, some of the theoretical conclusionsarrived at’ seem premature; f o r example, he puts forward the ideathat the a- or P-lactone structure may be applied t o glucosides,and, although this is quite admissable, it is most unlikely that theisomerism between the two crystalline methylglucosides can bereferred t o a difference in the mode of linkage of the ring-formingoxygen atom.According to existing views, these glucosides may berepresented by the formula: A and B, shown below, whilst, in Nef’sA . B. C. D.HC-OMe RleO*CH CH*OMe /CH*OMe~ H ~ O H ~ H - O H /&H.OH 0 AH-OH\dlH M H \&H ~ H ~ O Ko( 6H.OH ‘&I W, bHoOH .< LH~OH /I I ICH*OH CH-OH ~ H ~ O H CH*OHI I ICH,*OH\ / \ J YCH,*OH CH,*OH &H;OHIa-Methyl- a-Form B-Forniglucoside. P-PONIl. (stable). (unstable).65 J. C. Irvine and Miss B.M. Paterson, Zoc. cit86 ANNUAL REPORTS ON THE PROGRESS OF CHEMlSTRY.opinion, the isomezism does not depend on the position of themethyl group, but, as indicated in formulae C and D, on the exist-ence of different ring-structures in the molecule.These conclusions have been chalIenged by Fischer,66 who tabu-lates powerful arguments in favour of the older formulae and a tthe same time describes a new isomeric - form of methylglucoside(termed by him ‘‘ y-methylglucoside ”), which is characterised bythe extreme ease with which it is hydrolysed. For this reasonformula D may possibly be applicable to the new type of glucoside,although the exact linking is still uncertain. It may be remarkedthat, in addition to the evidence quoted by Fischer, the olderformulae for the alkylglucosides are also supported by recent deter-minations of their dissociation constants.67The present position of this subject is full of possibilities.Fischer’s discovery shows thatl recognition must now be given t o thepossible occurrence of a new mode of linking, both in glucosidesand in disacchasides.The structure of many important com-pounds, including the fructosides generally and sucrose in parti-cular, is involved. Although Fischer’s results are so far incom-plete, they can be verified by the experiences of the writer of thisReport, as y-methylglucoside, in the form of its methylated deriv-atives, has been recently encountered in attempts to prepare tri-methyl glucose from glucosemonoacetone.Another question involved in this‘ new development is the inadequacy of the existing system of nomenclature t o express thestructure of sugar derivatives.The expressions a and /3, asapplied to sugars and glucosides, refer t o definite stereoisomericforms, and their use has become standardised. The same alpha-betical system is, however, also used t o indicate the consecutivecarbon atoms of the sugar chain, and the results described aboveadd considerably to the consequent confusion. Fischer’s y-methyl-glucoside may be described as an a-, /3-, ti-, o r (-glucoside in thatthe oxygen &tom of the ring may be connected t o any one of thesecarbon atoms of the chain, whilst the compounds generally knownas a- and P-methylglucosides may, f o r similar reasons, be termedy-methylglucosides.These are by no means the only exampleswhich point to the necessity for radical changes in the presentusage.The fact that the y-oxidic linking present in on0 sugar derivativeneed not of necessity persist during the formation of other deriv-atives is emphasised by the results lately obtained in connexionwith the compound known as glucal. I n last year’s Report refar-66 E. Fischer, Ber., 1914, 47, 1980.67 L. Michaelis, ibid., 1913, 46, 3683 ; A., i, 16ORGANIC CHEMISTRY. 87ence was made to the unexpected course followed by the reductionof acetobromoglucose, and it is to be noted that the provisionalformula then ascribed to the product has now been modified asthe result of further work.68 The unsaturated and reducing pro-perties of glucal disappear when the compound is reduced catalyti-cally, the change involving the addition of two hydrogen atoms.From this result, and on consideration of the properties of thehydroglucal formed, an alternative st,ructure for glucal has beensuggested.This is indicated in the following scheme, which showsthe mutual relationship of these interesting compounds with theacetobromoglucose from which they are prepared :Acetobromoglucose.0 I OA~.CH,.CH(OA~).~H.CH(OA~)*CH(OA~).~H~~ ' Reduction by zinc and acetic acid J.Triacetylglucal.OAc*CH,* CH- UH,* CH (OAc)*C:CH*OA cI 0 IReduction by hydrogenand palladiumIGluc a1 . Hydrolysis\l0 H*CH,*~H*CtI,PCH(OH)*~:~~**~~ +Triacetylhydroglucal.OAc*CH,* &K*CH2*CH(OAc)*CH*CH2*OAc -0- I \H ydroglucal._- --upOH*CH,*bH* CH,* CH(OH)*UH*CH,*OH IThese remarkable and unexpected changes, taken in conjunctionwith Nef's results, will no doubt foster the development of thechemistry of the sugars on less stereotyped lines than has recentlybmn the case.Reactions of the type described above are notconfined t o glucose alone, but are apparently of general application.Thus, lactose 69 and cellobiose70 have been respectively converted68 E. Fischer, Ber., 1914, 47, 196 ; A . , i, 252.69 E. Fischer and G . 0. Curme, ibid., 2047 ; A., i, 931.7O E. Fischer and K. von Fodor, ibid., 2057 ; A . , i, 93288 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.into lactal and cellobial, which resemble glucal in their essentialproperties, and undergo similar hydrogenation t o give saturatedproducts.It is conceivable that many natural compounds, closelyrelated to the sugars, may possibly be derivatives of the glucals,and the suggestion has already been made71 that the “carbo-hydrate” group present in the nucleic acids is in reality related toglucal or an allied compound.A novel method €or the resolution of racemic sugars has alsobeen described, which is based on the formation of active mer-captals by the action of d-amyl mercaptan on inactive aldoses.72As mercaptals are usually easily purified, the process would appearto be experimentally simpler than the methods which depend onthe use of active hydrazine derivatives, but its range of applicationmay be restricted by the fact that the constitution of mercaptalsof this nature is quite unknown.GZucosides.-In last year’s Report, attention was directed torecent advances in the synthesis of glucosides by means of enzymes,and, although considerable progress has been made in the periodnow under review, it is unnecessary t o refer again to this line ofwork in anything like detail.It may be mentioned, however, thatin addition t o the synthesis of several galactosides and other com-pounds of simple type, the process of enzyme synthesis has nowbeen successfully applied to the formation of definite monogluco-sides of glycol and glycer01.7~ These results are mentioned as theyfurnish additional evidence that this method of synthesis can beutilised for the preparation of hydroxy-glucosides which are onlyobtained with exceptional difficulty by ordinary synthetical pro-cesses.The constitution of glucosides and many other structural ques-tions in the sugar group may be solved through the agency ofmethylation, but work of this nature has, in the past, been some-what restricted owing to the expense involved in preparing alkyl-ated sugars by the silver oxide method.A considerable simplifica-tion has, however, been effected, in that, under carefully controlledconditiosns, methyl sulphate and sodium hydroxide may be em-ployed for this purpme.74 I n view of the sensibility of manysugars and glncosides t o the action of acids or alkalis, the use ofthese reagents may seem surprising, but the results already avail-able show that the method is general in its application, whilst thofact that octamethyl sucrose can be prepared in quantity by this71 R Feulgen, Zcitsch.physiol. Chem., 1914, 92, 154 ; A . , i, 1098.E. Vatoeek and V. Vesely, Ber., 1914, 47, 1515 ; A., j, 664.73 E. Bourquelot and 31. Bride], Compt. rcnd., 1913, 157, 1024 ; A., i, 72 ; zbid.,7-l W. N. Haworth, P . , 1914, 30, 293 ; T., 1915, 107, 8.898 ; A , , i, 499 ; ihid., 1219 ; A . , i, 662ORGANIC CHEMISTRY. 89process suggests that the structural problems of the di- and poly-saccharides may now be investigated with reasonable prospects ofsuccess.There is no diminution in the synthetic applications of aceto-bromoglucose, and special reference must be made to the newseries of purine glucosides,75 which have been syntliesised by meansof this popular reagent.The general method of preparationadopted was t o employ the various purines in the form of theirsilver derivatives, and to act on the acetylated glucosides thusproduced wibh ammonia. The compounds isolated are of specialinterest, particularly in view of the fact that they may, in thefuture, be condensed with phosphoric acid, and thus give rise t osynthetic nucleotides. I n subsequent papers 76 the method is shownto be general, both with regard t o the nature of the purine andsugar constituents of t,he glucosides. The outstanding property ofthese compounds is the ease with which they are hydrolysed intotheir components, and this instability, which distinguishes purineglucosides from glucosamine derivatives, is doubtless due t o thefact that, in the former, nitrogen is directly attached to the carbonatom of the sugar chain which functions in the formation of thereducing group.77 Evidence is, in fact, accumuldting which pointsto the idea that the great stability which characterises nitrogenderivatives of the nature of glucosamine is due t o the formationof ring structures when an amino-group is in spatial proximity t othe acidic reducing group. This is emphasised in a publicationdescribing the conversion of glucosamine into mannose,78 and alsoreceives strong support from other work, where i t has been shownthat some of the reactions of a-amino-/3-hydroxy-compounds canonly be explained on the assumption that these substances maybehave as cyclic structures.79Another novel series of glucosides has lately been synthesisedby the interaction of acetobromoglucose and the silver salts ofthiourethanes.80 The I' mustard oil glucosides " obtained afterremoval of the acyl groups were, on further hydrolysis, convertedinto tliioglucose, which was isolated in the form of the silverderivative.Unfortunately, owing to the somewhat indefinite pro-'s E. Fischer and B. Helferich, Bey., 1914, 47, 210 ; A . , i, 333.76 E. Fischer, ibid., 1377 ; A., i, 662 ; E. Fischer anci K. von Fodor, ibid.,77 J. C. Irvinc, R. F. Thomson, and C. S. Garrett, T., 1913, 103, 238.78 .T. C. Irvine and A. Hynd, ibid., 1914, 105, 698.8O W. Schneider, D. Clibben, G .Hullweck, and W. Steibelt, Bey., 1914, 47,1258; A., i, 6 6 9 ; W. Schneider and D. Clibben, ibid., 2218; A., i, 977;W. Sc!ineider and F. Wrede, ibid., 2225 : A . , i, 977.1058 ; A , , i, 741.J. C. Irvine and A. W. Fyfe, ibid., 164290 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.perties of these compounds, their charaderisation is in the mean-time incomplete.Much patient and useful work continues to be expended on tQeisolation of natural glucosides, and the number of galactosidesrecently obtained in this way is st’riking, although there is stillconfusion as to whether these compounds represent cleavageproducts, derived from complexes, or exist in plants or animals inthe preformed state.81 This question has been raised before, andi t ia evident that, in view of the increasing number of galactosederivatives now being described and of their somewhat unusualproperties, the examination of the parent sugar in greater detail ishighly de-sirable.The natural alkaloidal glucosides are also com-pounds which present many difficulties, and it would appear thatthe meagre and confusing references t o these substances to be foundin the literature can be explained by the fact that several differentcompounds of this type have been described under the general nameof ‘’ solanine.” Some of these compounds are exceedingly com-plex,82 and it, is therefore important t o notice that a simple repre-sentative of the class has been isolated from Solanunz a m p s t i -foZium.83 Another interesting observation 84 is the extraction of adibenzoylglucoxylose from the leaves and stems of Daviesia Zatifolia,as this substance represents an entirely new type of natural com-pound.The glucoside is hydrolysed by alkalis with extreme easeto give the non-reducing disaccharide, Cl1H,,O,,, which, in turn,yields both glucose and xylose on complete hydrolysis. The occur-rence of bwo benzoyl groups in a natural compound is most unusual,and further research on the allocation of these substituents t odefinite positions will be awaited with much interest.Tannin.-Although comparatively few new experimental resultsregarding the constitution of tannin have been recently described,it is evident that the views advocated by Fischer are now meetingwith general acceptance. In particular, mention may be made ofthe fact that Nierenstein has now withdrawn his criticisms ofFischer’s structure, and brings forward evidence, based on thebehaviour of tannin towards yeast, that the glucose residue is anessential and combined constituent of the tannin molecule.s5 Thefact that specimens of tannin derived from different sources showvarying specific rotations has, in the past, been quoted in supportof the idea that glucose is present only as an accidental impurity0.Rosenheiiii, Biochem. J., 1913, 7, 604 ; A . , i, 225 ; ibid., 1914, 8 , 110,121 ; A , , i, 706; E. E’ischer, Ber., 1914, 47, 456 ; A . , i, 389.F. Tutin and H. W. B. Clewer, T., 1914, 105, 559.*) G. Odd0 and M. Cesaris, Gnzzelta, 1914, a, ii, 181 ; A ., i, 1173.84 F. B. Power and A. H. Salway., ibid., 767, 1062.85 A. Geake and M. Nierenstein, Ber., 1914, 47, 891 ; A . , i, 567ORGANIC CHEMISTRY. 91in tannin. It has, however, now been shown as the result ofcareful fractional precipitation of commercial tannin that a numberof feebly rotatory isomerides or impurities are present in averagespecimens.86 It may be noted in passing that Fischer’s views admitnot only of the existence of several isomerides, the rotations ofwhich would doubtless lie far apart, but also of the occiirrence ofpartly substituted glucoses in association with tannin.Perhaps the most important recent contribution to the tanninproblem is a critical examination of the constitution of tanninderived from Turkish and from Chinese galls.87 It has already beennoticed that the glucogallic acid isolated by Feist from Turkishgalls is not identical with the P-glucosidogallic acid synthesised fromacebobromoglucose.The opinion hazarded in last year’s report asto the structural difference between these compounds has now beenconfirmed, as, on methylation of glucogallic acid, a non-reducingproduct is obtained, and this, on hydrolysis, yields gallic acidtrimethyl ether. The conclusion is drawn that, in the compoundunder discussion, the glucosidic linking involves the carboxyl group,whereas, in the synthetio isomeride, the coupling of the hexoseand aromatio residues involves a phenolic group. This distinctionin structure is shown below :0-7C,H,(O H),*CO*O*dH*[CH*OH],*CH*CH(OH)*G K,*OII,(I. ) Natural glucogallic “ acid.”CO,EI*C,H,(OH),*O*CH* [CH*OH1,*CH*CH(OH)-CH2*O K.,~ ---()-I(11.) Fischer’s synthetic glucosidogallic acid.A t the same time, although this question of isomerism has prob-ably been definitely settled, the att’empts to confirm formula I bysynthesis are not convincing. The constitution of the glucogallicacids is, of course, a side-issue of the tannin problem, but themethylation process has also been applied by Feist to t’he elucida-tion of the structure of tannins derived from various sources. Theprinciples involved in this method of attack have already beendescribedF8 and, although scrutiny of the experimental detailsgives the impression that the methylation was far from being com-plete, there seems to be no reason why this general method shouldfail to solve the problem, considering the success which has attendedsimilar attempts to methylate cellulose.86 T,. F.Iljin, Ber., 1914, 47, 985 ; A . , 567. *’ K. Feist and H. Ham, Arch. Plzarm., 1913, 251, 468 ; A . , i, 195.s8 J. C. Irvine, Biochem. Zeitsch., 1909, 22, 35792 BNNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Disacclzarides aiid Yolysaccharides.As usual, the number of papers dealing with the chemistry ofdiswcharides has been very large, but outside of work the mainobject of which was obviously technical or analytical there is com-paratively little t o report.The debatable question as to whether the inversion of sucroseby invertase is reversible or not has been answered by Hudson inthe negative,*g as in the course of an elaborate investigation, carriedo u t with great care and with the aid of specially active invertase,g*the results indicate that the hydrolysis of the disaccharide is com-plete.The synthesis of sucrose by enzyme action is apparentlya reaction which has still to be accomplished, in the laboratory atall events, but, on the other hand, evidence has been obtained9'that dextrorotatory polysaccharides of the nature of glycogen areformed under certain conditions during the alcoholic fermentationof glucose and fructose.Last year i t was noticed that few publications on the complexcarbohydrates were available for review, but 011 this occasion thedifficulty has been reversed, as the contributions under this head-ing have been both numerous and important.Convincing experi-mental evidence has now been obtained that the action of coldconcentrated hydrochloric acid on starch results in rapid degrada-tion, through the usual successive stages, to maltose, the speed ofthis reaction being much superior t o that of the conversion ofmaltose into glucose. It is shown in the paper now under con-sideration92 that the hydrolysis of starch by acids proceeds 011essentially similar lines to the action of taka-diastase on the poly-saccharide, and that in each of these reactions the glucose finallyproduced is entirely derived from maltose. In this connexion,reference may be made t o an interesting account of the action oftaka-diastase on starch, in which the successive formation ofpa-maltose, aa-maltose, and glucose is clearly illustrated by graphici11ethods.93 Another result, which will not be considered altogethersurprising, has been arrived a t in the course of these investigations.It is now shown that the action of concentrated hydrochloric acidin effecting the auto-condensation of glucose extends to solutionscontaining as little as 1 per cent.of the sugar. This observationweakens the conclusions drawn by Willstatter and Zechmeister 9489 C . S. Hudson and €1. S. Piline, J. Amer. Chem. Soc., 1914, 36, 1571 ; A , ,i, 1148.C. S. HII~SOII, ibid., 1566 ; A., i, 1147.y i A. Harden and W. J. Yoling, Eiochem. J., 1913, 7, 630 ; A . , i, 237.'J2 A. J. Daish, T., 1914, 105, 2053, 2065.y3 W.A. Davis, J. SOC. Dyers, 1914, 30, 249. Ann. Eeport, 1913, 87ORQANIC CHEMISTRY. 93as to the glucose content of cellulose, but, fortunately, does notseem to affect adversely the attempt t o deduce the structure ofcellulose by methylation, which was described last year. From thefact that a definite crystalline trimethyl glucose lias now beenobtained by hydrolysis of methylated cellulose by nieans of highlyconcentrated hydrochloric acid, there seems every reason to hopethat the linkage of the hexose residues in the polysaccharide willsoon be ascertained.95To return to the subject of the diastatic hydrolysis of starch, i tmust be admitted that the process is, in all probability, much morecomplex than is generally supposed. There is even considerabledoubt in the minds of all who have worked with maltose as towhether a perfectly pure specimen of this sugar has ever beenobtained, and the opinion is gaining ground that the substanceusually described as maltose is a mixture of closely related com-pounds.To the evidence already available may be added theobservation that, during the action of malt diastase on starchg'ranules,QG a dextrin is produced the molecular weight of which isnearly equal to that of maltose. Again, many recent experi-ments97 go to show that average specimens of starch consist ofmixtures of compounds which are practically identical in theirproperties, and this may serve t o explain many of the discordantresults to be found in the literature, both with regard to starchand to maltose.Even granting that maltose is a definite chemical individual, itis doubtful if the structure a t present assigned to the compound iscorrect.Direct experimental methods bearing on this question aredifficult to obtain, but reference may be made to a novel attemptto ascertain the structure of maltose, which depends on an applica-tion of Nef's work in the sugar group.98 Curiously enough, theoxidation of maltose by means of alkaline hydrogen peroxide pro-ceeds, to a large extent, without disruption of the disaccharideinto glucose. The essential product thus obtained was a glucosido-glycollic acid, which was subsequently hydrolysed into glucose andglycollic acid. So far as these results go, it would appear thai,Fischer's formula for maltose, if not confirmed, is a t leastsupported.95 W.S. Denham and Miss H. Woodhouse, T., 1914, 105, 2357.97 C. Tanrct, Compt. rend., 1914, 158, 1653 ; A,, i, 665 ; ibid., 1914, 159, 530 ;98 W. L. Lewis and S. A. Buckborough, J. Awaer. C'hesn. Soc., 1914, 36, 2385 ;J. L. Baker and H. F. E. IIulton, iijid., 1529.A., i, 1167A , i, 119994 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Nitrogen Compounds.Excluding results which are more appropriately discussed undercyclic compounds, or those which bear directly on the problems ofphysiological chemistry, comparatively few definite advances havebeen made in the study of aliphatic nitrogen compounds duringthe past year. Obvious causes have contributed to this fact, but,a t the same time, it must be admitted that a certain amount ofirregularity and the absence of a definite object characterises muchof the synthetical research in this field.Again, as already in-dicated, the extensive and important kork now being carried outin the purine group hvolves reactions which are characteristic ofring structures rather than of open-chain compounds, so that a com-paratively small number of topics are available, on the presentoccasion, for this section of the Report.Carbamides.-Considering the present position of our views re-garding tfie mechanism of processes operative in solution, it is notsurprising to find that the study of the formation and decomposi-tion of carbamide has again been revived.I n this connexion, it may be noted that the earlier work ofWalker and pupils on the change ammonium cyanate + carbamidehas now been completed, so far as the determination of the effectof alcohol on the velocity of the reaction is concerned.Hitherto,on the basis of conductivity measurements, the change has beenregarded as dependent on the interaction of NH,' and CNO' ions,even when 90 per cent. alcohol is used as the solvent, and it isnow shown that for alcohol concentrations increasing from 90 to99.9 per cent. the steady acceleration of the translormationpreviously observed is maintained. This acceleration holdswhether the reaction is referred to the ions of ammonium cyanateo r to the non-ionised salt.99 On the other hand, the addition ofalcohol to aqueous or acid solutions of carbamide exerts a markeddiminution in the velocity of the decomposition into ammonia andcarbon dioxide.1 This result, although apparently unexpected,certainly supports the idea that the change in question involvsthe preliminary formation of ammonium cyanate, and is not adimple hydrolysis.It should be mentioned that the effect of methyl sulphate as amethylating agent has recently been applied successfully tocarbamide and its homologues, with the result that methyl ethersof the corresponding isocarbamides are formed.2 Quite apartfrom the interest attached to this direct formation, from carb-G.J. Burrows and C. E. Fawsitt, ibid., 609.E. A. Werner, ibid., 923.99 J. D. M. Ross, T'., 1914, 105, 690ORGANIC CHEMISTRY. 95amides, of derivatives possessing the iso-structure, the reactions ofthe ethers formed are important from the structural point of view.Thus, when strongly heated, these compounds undergo molecularrupture, the nature of which may be seen from the followingrepresentation of the decomposition of isocarbamide methyl etherin the form of its methyl hydrogen sulphate:H ':..NH2*CH,*HS0, Me*NH,,CH,*HSO, + HN:CO1 /;.ir'%JH,,CH,*HSO, + [Me*OCN + Me-NCO]This dois not exhaust the list of decomposition products, butwill indicate the general grounds upon which the idea is basedthat the constitution of monoalkylisocarbamidm is best expressedby the cyclic structure RN:C<yH3, which, in turn, is a reason- 0Compared with able modification of the formula RN: C<carbamide itself, the tendency of tliiocarbamide to react in simplechanges in accordance with the iso-structure is much more pro-nounced.Several examples may be quoted to illustrate this dis-tinction, and mention may be made of one o r two very emphaticcases which have recently come t o light. By tlhe action of chloralhydrate on carbamide,3 direct aldol condensation results, whichmay involve one or both of the amino-groups, giving the productsN:C/ I ',t\ d M eNIT,OH 'CCl,*CH(OH)*NH*CO*NH, andCCl,*CH(OH)*NR*CO*NH *CH(OH)*CCl,.I n each case the properties of the products are in agreement withthe idea that they are derivatives of normal carbamide, althoughtheir behaviour towards acetic anhydride is somewhat irregular.4On the other hand, thiocarbamide reacts with chloral hydrate inan entirely different manner, as hydrogen chloride is eliminatedduring the reaction, with the ultimate formation ofThe general nature of this reaction is, therefore, similar to thatwhich ensues when monochloroacetic acid acts on carbamides, asin this case, also, the elements of hydrogen chloride are removed,as shown in the following typical example: 5NH,*C(:NH)*S*CCl,*CH(OH),.NHZ*C(:NH)*SH + C?H2Cl.C0,H=NH,*C(:NH)*S*CH,*CO,H + HCl.It would appear, however, from a scrutiny of Feist's work thatF.Feist, F. Nissen, and G. Stadler, Ber., 1914, 47, 1173 ; A., i, 666.' N. G. S. Copyin and A. W. Titherley, T., 1914, 105, 32.' P. C. Ray and F. V. Fernandes, T., 1914, 105, 215996 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.reactions of the latter type proceed only under the mildest possibleconditions, and the complexity of the reactions of thiocarbamidesis further emphasised by the behaviour of these compounds towardshypobromites,G as in certain cases only one atoin of iiitrogen isevolved in the reaction, whilst in others both nitrogen atoms arestable.Again, the action of substit'uted malonic esters on carb-amide and thiocarbamide is utterly distinct,7 although it is to benoted that thiocarbamide reacts with ethyl aminomalonate accord-ing to the normal structure t o give 2-thiouramil,A mino-acids.-A somewhat curious position has arisen in con-nexion with the chemistry of amino-acids, as the synthesis anddecomposition of optically active representatives of this class havepractically ceased.As pointed out last year, this is probablylargely due to the uncertainty with which all synthetical work ofthis nature is invested, owing t o the occurrence of optical inversion,Work in this field is therefore, in the meantime, largely limited t othe identification of naturally occurring amino-acids, the synthesisof simple types, and a study of the general reactions of the com-pounds without reference to their optical behaviour.The optical activity of amino-acids is doubtless a complex factor,owing to the tendency of these compounds to form internal salts,and even the rotation of their metallic salts is affected by the factthat they are hydrolysed in aqueous solution.9 This is shown bythe alterations in rotatory power observed when increasing amountsof acid or of alkali are added t o solutions of an active amino-acid.I n the case of a inonobasic acid, the specific rotation undergoessteady alteration until slightly more than the equivalent amountof acid or alkali has been added, after which, on further addition,the optical value remains constant.With dibasic acids, thesealterations in rotation are even more instructive, and in such cases,also, constant values are only obtained when the amount of addedalkali or acid is slightly in excess of that required for completeneutralisation. I n the paper now referred to, the results are ex-tended t~ a determination of the degree of hydrolysis of salts ofamino-acids, and to a calculation of the basic and acidic ionisationconst'ants of the acids examined by this polariinetric method.The results just described do not seem to be affected by the forma-tion in solution of betaine-like salts, but fresh evidence bearingon this point has been obtained in another investigation, whichti V.von Cordier, Honntsh., 1914, 35, 9 ; A . , i, 258.7 T. B. Johnson and A. J. Hill, J. Amer. Chem. Xoc., 1914, 36, 364 ; A . , i, 330.8 T. B. Johnson and B. H. Nicolet, ibid., 355 ; A . , i, 328.J. K. Wood, T., 1914, 105, 1988ORGANIC CHEMISTRY’. 97deals with the action of diazomethane on amino-acids and theiracetyl derivatives.1° It appears that the reagent is without actionon the free acids, so that, under the conditions of the experiment,a functional carboxyl group is absent.On the other hand, methyl-ation proceeds normally in the case of substituted amino-acids,indicating the presence in these compounds of a normal carboxylgroup. The conditions under which a-amino-acids react as cyclicstructures are, so far, imperfectly understood, and i t is desirablethat further research, involving physical methods, should bebrought to bear on the subject, as i t is no doubt intimately con-nected with the mechanism of the Walden inversion as experiencedwith these compounds. The action of nitrous acid on a-amino-acids is, of course, comparatively regular, but is occasionally accoin-panied by inversion or racemisation, and Fischer has recentlyencountered another example which emphasises this point.11Obviously, the elimination of the amino-group will follow adifferent course, according as the amino-acid is present in either ofthe two structural forms shown below:and in optical studies of this change it would be highly desirableto be in possession of an accurate physical method of determiningthe relative amounts of these isomerides present during the de-composition.It is conceivable that in this way some furthergeneralisations underlying this important change may yet berevealed .The above structural views may also serve to, explain some ofthe discordant reactions of anhydrides, derived from amino-acids,which have recently been described. For example, the observa-tion that aminoacetaldehyde is produced by the electrolytic reduc-tion of glycine anhydride12 is not consistent with the normalformulaNH-COas the group *CO*NH* is converted in such reactions into*CH,*NH,. It has, in fact, been suggested that diketopiperazineis more accurately represented by the formulaCH,<CO.NH>CH2,NH*NHa structure which would easily be derived from the cyclic formof glycine.JAMES COLQUHOUN IRVINE.lo A. Geake and M. Nierenstein, Zeilsch. physiol. Chin., 1914, 92, 149 ; A., i,1057. l1 E. Fischer and R . Ton Gravenitz, A?znaZen, 1914, 406, 1 ; d., i, 1057.l2 G. W. Heimrod, Ber., 1914, 47, 338 ; -4., i, 327.CH,<~*--CO>CH27REP.-VOL. X I . 98 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.PART II.-HOMOCYCLIC DIVISION.IN spite of the decrease in the output of literature during the lastthree months of the period under review, the earlier portion ofthe year showed no falling off in the number of papers dealing withthis branch of Organic Chemistry.It will be observed that nowriter of the reports on this division of the Science, since theirinception, has failed t o remark on the difficulties of the task ofselection with which he was confronted, and has offered apologiesfor his many omissions. Indeed, no report could do justice to themass of material which did not reproduce, in their entirety, theabstracts published in the Journal. To compress into1 a few pagesa review of these numerous researches, when none of them can bedescribed as brilliant and most of them are good, necessitates aselection which, in the nature of things, must be largely haphazard.The writer has therefore selected those communications whichseemed to him t'o be the more important, but he is fully consciousof the fact that he has neglected much that is of value.One of the most striking features of the literature under reviewis the large proportion which is devoted to the mere statement offact, and the small amount which deals with the principles under-lying these facts.This condition is, of course, a natural outcomeof the great increase in the quantity of literature published duringpast years, which, becoming an intolerable burden on the financialresources of the publishing societies, has necessita.ted the shorten-ing of papers, sometimes t o such a degree as to render them hardlyintelligible. I n any case, the discussion of the results of otherworkers, unless concrete facts are disputed, is either reduced to aminimum o r entirely ignored. This is particularly noticeable ininternational work, and one could easily believe that, in certaincountries, no notice whatever is taken of papers published abroadwere it not for the fact that internal evidence to the contrary isoften forthcoming.Another disquieting feature is the increasing number of state-ments which, on subsequent investigation, have proved t o be wrong.Many of these, no doubt, are due to clerical errors, but no onewho is conversant with the literature of modern organic chemistrycan have failed to meet with cases which can only be ascribed t oother causes.I n the ensuing report, the various data have been collected, sofar as possible, under general headingsORGANIC CHEMISTRY.99Nitration.I n view of the importance attaching to trinitrotoluene (T.N.T.)a t the present time, a communication by W. Will1 is of interest.Of the six possible trinitro-derivatives of toluene , only three areknown, namely , the pure commercial article, the so-called u-trinitro-toluene (m. p. 80*6O), which is 2 : 4 : 6-trinitrotoluene; y-trinitro-toluene (m. p. 104O), obtained from m-nitrotoluene, which is2 : 4 : 5-trinitrotoluene ; and the P-isomeride (m. p. 112O) , formedby the nitration of both 2 : 3-dinitrotoluene and 3 : 4-dinitrotoluene,which is 2 : 3 : 4-trinitro€oluene. The three isomerides are prac-tically of the same value as explosives.A search for higher nitrated derivatives proved unsuccessful,because if the reaction is promoted by heat or pressure, eithertrinitrobenzoic acid, or even tetranitromethane, is obtained.It ispointed out that the intense colour of the latter substance is some-times noticed in the factory, but that trinitrobenzoic acid, owingt o the solubility of its salts, has hitherto escaped detection; itspresence is likely t o be a source of danger. The author has ex-tended his researches to benzene, and considers t'hat it is extremelydoubtful whether a higher nitrated derivative than trinitrobenzeneexists.An interesting example of the failure of the aldehyde group t oexert its usual directive influence into the meta-position isdescribed by W.H. Perlun and R. Robinson2 in the nitration ofo-veratraldehyde. The formula of the aldehyde (I) shows thepositions a and b to be symmetrically placed as regards themethoxy-groups :Me0 Me0 Me0XeO/)CIIO M~O/)CHO Mo0f)GHO'\P \/ \?*2(111.)b NO2(1.1 (11.1It might reasonably be expected, therefore, that the m-nitro-derivative (11) would be formed on nitration, whereas the soleproduct is the o-nitro-derivative (111).A method for preparing nitro-compounds from amino-compoundsby the spontaneous decomposition of the nitrites of the correspond-ing diazo-compounds is described by W. Korner and A. Contardi.3The process appears to be of some value, since, for example,2 : 6-dibromosulphanilic acid can be quantitatively converted byBer., 1914, 47, 704; A., i, 509.Atli R.Accad. Limei, 1913, [v], 22, ii, 625 ; d . , i, 263.T., 1914, 105, 2376.H 100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.this means into’ 2 : 6-dibromonitrobenzeiie-4-sulphonic acid, and twosubstituted dinitrobenzenes can also be prepared from the corre-sponding nitro aniliiies.The bromine-titration method, applied with success to ethyl aceto-acetate and similar substances, has been extended to an investiga-tion of the desmotropism exhibited by nitro-compounds and nitro-ketones.4 There appears to be a fundamental difference betweenthe phenomenon as shown by this type and that exhibited by theketo-enol compounds. Thus, whereas the enolic form of, forexample, ethyl acetoacetate is favoured least by water, more bymethyl alcohol, and still more by ethyl alcohol, the reverse is thecase with the isonitro-compounds. This observation is in accordancewith the rule that the proportions of the two isomerides dependon their solubilities in the solvent, for enols are less soluble thanketones in water, but aci-compounds are more soluble than truenitro-compounds.A z o-compouids.K.H. Meyer and S. Lenhardt5 have already proved that, con-trary to the usually accepted idea, not only phenols, but phenolicethers, couple with diazonium salts to form azo-compounds.Investigation now shows that, spe’aking generally, the introduc-tion of negative groups into the diazonium salts increases theiractivity towards coupling with phenolic ethers.Thus thediazonium salt derived from 2 : 4-dinitroaniline couples readily withanisole and with phenetole, and combines immediately with theethers of resorcinol and a-naphthol. On the other hand, the intro-duction of negative groups into the phenolic ethers diminishes theirtendency to couple, whilst positive radicles, especially alkyloxy-and alkyl groups in the meta-position, increase the tendency toform azo-compounds.K. v. Auwers and F. Michaelis’ confirm the latter statement,but point out that a free para-position is essential, and that thespeed of the reaction is increased when there is a second alkylgroup in the ortho-position, and is a t its maximum when the twoalkyl groups are both meta to the ether group.There is a great deal to be said for the view advanced by K.H.Meyer6 and his co-workers to the effect tllat this coupling repre-sents an addition of the diazo-salt to a double bond of the secondcomponent. They point out that the methyl ether of 9-methyl-anthranol, which possesses no “active” hydrogen atom in theK. €1. Meyer anil P. Wertheimer, Ber., 1914, 47, 2371 ; A!., i, 1061.Annnlen, 1913, 398, 66 ; A., 1913, i, 723.K. H. Meyer, A. Ir>chick, and H. Schliisser, Ber., 1914, 47, 1741 ; A . , i, 882.Bey., 1914, 47, 1275; A , , i, 744ORGANIC CHEMISTRY. 101ortho- or para-positions, can nevertheless couple with p-nitro-benzenediazonium hydroxide, in accordance with the scheme :They therefore regard the coupling of a diazoniuin salt. with apheiiolic ether as taking place in the following manner:H \ / OMe\/’ -= \/ -+NR:N/\ -/\OH / \/ \for the fact that, in some cases, the This exDlanation also accounts Icoupling of the diazo-compound and the alkyloxy-compound yieldsa large proportion of the free hydroxyazo-derivative.The supposed isomeride of azobenzene obtained by C.V. andR. A. Gortner? which melted a t 25O, and was found t o be con-vertible into ordinary azobenzene (m. p. 68O) by means of dilutehydrochloric acid, has been investigated by H. B. Ilartley andJ. M. Stuart,g and is found to be a solid solution of azobenzenein azoxybenzene.It is well known that phenol and o- and ?n-cresol form bisazo-compounds in concentrated, but not in dilute, solutions ; thymoland carvacrol also react in the same way.It is now pointed out7that the tendency to the formation of bisazo-compounds rises withthe number of alkyl groups in the phenol molecule, whereas thepresence of other substituents, such as the nitro-, carboxyl, andcarboxylic ester groups, destroys, not merely the tendency to, butfrequently the possibility of, such condensation. It is also statedthat, as a general rule, negative substituents diminish the re-activity of the phenol and that the formation of the bisazo-com-pound is contlrolled not so much by the speed of coupling of thephenol as of the monoazo-compound. Bisazo-compounds are bestformed in alkali hydroxide solutions, not so well in the presenceof alkali carbonates, and scarcely a t all in acetic acid.J.Anzer. Chcm. Soc., 1910, 32, 1294 ; A, 1910, i, 790.3:, 1914, 105, 309102ThetionalANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.so-called diazophenols can be representesd by three constita-formulz,R<ONiN(1.1 (11.) (111.)Wolff’s researches have rendered formula I improbable, and he,with Hantzsch, favours the third constitutional formula. A.Klemenc10 now brings forward evidence in favour of formula 11.IIe argues that whilst the explosive character of these compoundsagrees with either constitution, the fact that the substances dissolvein concentrated acids and can be recovered on dilution wouldsuggest that they cannot be quinone-diazides of formula 111. Itseems highly improbable that any definite chemical evidence willever be obtained which will differentiate between compounds offormulae I1 and 111, although it is to’ be remembered that, as theBlomstrand diazonium formula is a t present fashionable, i t appearsreasonable to assign formula I1 t o the diazophenols, since they havemany characteristics in common with the diazonium salts.Colour and Constitution.As the result of the comparison of a large number of colouringmatters, a theory is advanced,ll by which it is stated that thosedyes which are quinonoid in all possible tautomeric forms exhibita deep colour, whereas those which can be represented by formulznot containing the quinonoid structure are paler in shade.Although this working hypothesis is amply supported by the factsadvanced, yet i t is evident that the generalisation fails t o accountf o r many changes in the intensity of colour which are met within compounds of closely similar structure and molecular weight.One instance of this kind may be mentioned, namely, the occur-rence of blue colours by the coupling of naphthol derivatives withdiamino-bases which yield substantive cotton dyes, whilst the samesecond component yields red colouring matters with those diamino-bases, of closely related structure, which do not produce substantivecotton colours.The suggestion originally made by J.T. Hewitt and A. D.Mitchell 12 that substances of the t*ype of pnitrobenzeneazo-a-naphthol and its potassium salt have structures represented by theformuke/-\ /-\\-/ \-/\-/ \-/ \-/ \-/ O,N,’-\N:N*/ \OH and KO,N:/ -\:N*N:/ \:Ol o Bcr., 1C14 47, 1407 ; A , , i, 743.l2 T., 1906, 89, 19 ; ibid., 1907, 91, 1251.l1 E.R. Watsofi, T., 1914, 105, 759ORGANIC CHEMISTRY. 103has received support by an extension of the work13 to pamino-acetophenone and paminobenzophenone in combinatJon withphenol, 0-cresol, and a- and 6-naphthol. The results are in accord-ance with the view that these compounds and their salts shouldbe represented by type A, whereas the corresponding phenyl-hydrazones are t o be expressed by type B:j' CH,*CO*C,EI,*N:N* @,H4* OH.1 CH,= c (OK) : C,H4: N-N: C,H4: 0.A.CH,*C( :N*NH*C',~,)*C,H,*hT:N~C,H,~OH.CH,*C( :N*NH*C6H,)*C,H,*N:N=C6H4*OK.The large amount of work on the nitroaminophenols which hasbeen carried out by R.Meldola and his collaborators f o r manyyears past has led to the important conclusion14 that the conditionessential to the production of deep colour is the ortho-position ofa nitro-group with respect to an amino- or substituted amino-group.The presence of additional nitro-groups in the nucleus has gener-ally the effect of increasing the intensity of the colour. It isevident that the appearance of colour in these cases cannot bedue to the mere presence of nitro- and amino-groups in the nucleus,but must be caused by some more profound change in structure.The compounds named are theref ore given the structures indicatedby the numbered formulze : 3 : 5-dinitro-paminophenol (I), 2 : 3 : 6-trinitro-p-aminophenol (11), and 2 : 3 : 5-trinitro-panisidine (111) :OH OH 0-CH,(111.)(Red.)An important illustration of the property of colour in relationto tautomerism is brought forward by R. Meldola and W. F.Hollely15 in connexion with the compound formed by the inter-action of 2 : 3 : 5-trinitroaceto-panisidide and aniline. The freecompound can be obtained in pale, ochreous needles (IV) or deepred scales (V), the two forms being interconvertible. Both modifi-cations dissolve in alkali, forming a deep orange solution of com-pound V I :It J. '1'. Hewitt, Miss G. R. Mann, and F. G . P o p , T., 1014, 105, 2193.l4 R. Meldola and W. F. Hollelg, ibid., 414.l5 Bid., 977104 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Friedel and Crafts’ Reaction.I n the last volume of these Reports10 attention was drawn to thelarge amount of work which has been published recently on thevarious applications of this reaction, and a t the same time a valu-able summary was given respecting our knowledge of the mechanismof the process.During the period under review, several papershave appeared which have an important bearing on this question.S. C. J. Olivierl’ has conducted certain dynamic researches on thecourse of the reaction, p-bromobenzenesulphonyl chloride beingused, since it not only reacts with measurable velocity, but is notdecomposed by water at the ordinary temperature. Evidence wasobtained of the formation of the additive product showing that,partly a t any rate, the reaction proceeds in accordance with thescheme :C,H,Br~SO,Cl,AlCl, + C,H, -+The following conclusions were drawn :(1) The acid chloride reacts solely in the form of the compoundC,H,Br*SO,CI,AlCl,.(2) One molecule of aluminium chloride cannot transform morethan one molecule of acid chloride.(3) The reaction is unimolecular with respect to the compoundC,H,Br SO,Cl, A1 Cl,.(4) The reaction constant (when an excess of aluminiumchloride is not used, and if K is calculated for the compoundC,H,Br*SO,Cl,AlCl,) is proportional to the concentration of thealuminium chloride.(5) The constant is greatly increased by an excess of aluminiumchloride.These facts are most readily explained on the assumption thatthe acid chloride is activated proportionally t o the concentrationof the combined aluminium chloride. When benzene is replaced byits derivatives, reaction occurs with diminishing rapidity in theorder benzene, bromobenzene, chlorobenzene.No reaction wasobserved with nitrobenzene. It should be added that the aboveC,H,Br*SO,*AlCl, + C,H,CI + HCI.?6 Ann. Xcport, 1913, 97. l7 Rec. tmv. cJ&n., 1914, 33, 91 &A,, i, 818ORGANIC CHEMISTRY. 105conclusions receive support from the observation of C. R. Rubidgeand N. C. Qua,18 who find that, in the reaction between benzoylchloride and benzene in the presence of aluminium chloride, theyield is considerably diminished if the amount of aluminiumchloride is reduced.On the other hand, B. N. Menschutkin19 has continued his ex-periments on the influence of antimony trichloride and antimonytribromide on condensations of the Friedel and Craft type.Thefirst phase in the reaction invoIves the formation of a compoundof the antimony salt with the hydrocarbon, 2SbC1,,C6H,R. Thiscompound is then acted on by, for example, benzoyl chloride,yielding a compound of antimony chloride with the ketone,SbCl,,C,H,*CO-C,H,R, which decomposes into its constituent8 atthe temperature of the experiment. The antimony trichloride thusliberated may then react with fresh quantities of hydrocarbon andbenzoyl chloride.ArH + C,H,*COCl + SbC1, = Ar-CO*C,H, + HC1+ SbCl,,proceeds t o an end, and gives results in accordance with a bimole-cular reaction, the hydrocarbon and benzoyl chloride being takenalways in molecular proportions. The velocity of the reactionvaries directly as the square of the concentration of the antimonytrichloride.It is certainly difficult to bring the results of these two investi-gations into line, and it is evident that the problem of themechanism of this reaction is still unsolved.It should be addedthat J. Boeseken and M. C. Bastetzo bring forward furtherevidence in supportl of their view that the Friedel and Craft re-action takes place when three molecules are present, the first ofwhich is unsaturated, the second of which can be activated to suchan extent that i t is decomposed during the reaction into two parts,which then unite with the first molecule, and the third of whichcan activate the two molecules. The authors describe a series ofcondensations between benzene and various chloro-derivatives ofethylene in which, in the first stage, the molecule of benzene isdisrupted, and then forms a compound with the unsaturated mole-cule; the latter molecule then becomes disrupted in its turn, andcombines with a second or third molecule of benzene, which nowbehaves as if it were unsaturated.It has been shown21 also that aluminium chloride may be usedas a means of effecting the' elimination of water in certain typesl8 J.Anzer. Chena. Soc., 1914, 36, 732 ; A . , i, 589.lY J. Iiuss. Phys. Cham. SOC., 1913, 45, 1710; 1914, 46, 259 ; A . , i, 188, 673.2o Bec. trnv. chim., 1913, 32, 184 ; A., i, 156.21 G. B. Frankforter arid W. Kritchevsky, J. Amer. Chem. SOC., 1914, 36, 1511 ;The tot21 reaction, expressed by the equationA,, i, 1059106 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of condensation.Thus hydrocarbons of the aliphatic, benzene,naphthalene, and anthracene series have been condensed, not onlywit,h chloral, but also with chloral hydrate and bromal, thereactions, which are carried out a t Oo, being represented by theequation2RH + CC13*CH0 = CHR,*CCl, + H,O.Biphenyl Series.The stereochemical formula for diphenyl originally proposed byKaufler22 to account for the production of cyclic compounds ofthe type of phthalylbenzidine,Q,H,*NH*CO*C,,H,*N H* CO >C,H,has apparently received support by recent investigations in thediphenyl series.23 J. C. Cain, A. Coulthard, and Miss F. M. G.Micklethwait 24 have shown already that two distinct o-dinitro-benzidines exist, and the cause of this isomerism becomes apparentif it is assumed that in the Kaufler formula,2’- 3’there is no free rotation between the two benzene rings.The twodinitro-derivatives are therefore 3 : 3’- and 3 : 5/-dinitrodiphenyl.An extension of the work to o-tolidhe25 has led t o the isolationof two, dinitro-o-tolidines, and in this instance it was found possibleto convert one of them into the other.Considerable interest a.ttaches to the fact that the four possible*g2 Annalen, 1907, 351, 151 ; Bcr., 1907, 40, 3250 ; A., 1907, i, 794.2 3 J. C. Cain and Miss F. M. G. Micklethwait, T., 1914, 105, 1438.24 T., 1912. 101, 2298.2.5 J. C. Cain aiid hliss F. M. G. Micklethwait, ibid., 1914, 105, 1442.* The writer is under the impression that there are six possible isomerides and thatthe two formu18shotild be included.rings and the argument is not affected by their exclusion.These compounds contain, however, two dissimilar benzenORGANIC CHEMISTRY.107m-dinitro-derivatives of o-tolidine required by the Kaufler formulahave been isolated, namely,and it is csrtainly remarkable that no less than three of thesegive distinct carbazoles on reduction. This involves, in a t leastone case, the production of tram-linking, thus :Such linking is, of course, known, since the trans-forms of manydialkylsuccinic acids, compounds in which the ring-f ormingelements are separated in the same manner as in these reducednitro-compounds, yield their own anhydrides, but if this is thecase the trans-carbazole should be readily convertible into its cis-isomeride, which must be identical with one of those derived fromthe other two bases.It is to be noticed, moreover, that Cain andMiss Micklethwait 26 prepared condensation products of benzidinewith o-diketones to which they assign the formula:/-'\N: CRan assumption which, if correct, would give strong support to theKaufler formula. J. Kenner and Miss A. M, Mathews27 point out,however, that in no case was it found possible t o free these con-densation products from the two molecules of alcohol or othersolvent which always accompany them, and they remark thatTauber28 does not appear t o have experienced any difficulty inobtaining similar free condensation products from 2 : 2I-diaminodi-26 LOC.cit., p. 1440.28 Ber., 1892, 25, 3287 ; 1893, 26, 1703 ; A . , 1893, i, 96, 588.T., 1914, 105, 2473’108 tlNNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.phenyl. They also argue 29 that i f Cain and Miss Miclrletliwait’sview as to the isomerism of the’ two dinitrobenzidines is correct, it isto be anticipated that the prevention of rotation of the two benzenenuclei would also be exhibited in 2 : 2’-diphenyldiacetic acid. Suchis, however, not the case, since whilst diethyl diphenyldiacetatefurnishes ethyl dibenzocycZoheptadienecarboxylate,”O diphenyldi-acetyl chloride can be converted into hydroxypyrene (11) 31 :/\I bH(C0, EX)--\y o ‘4IThis argument is, of course, by no means conclusive, since i t isconceivable that the reagents used niight have caused rotation ;moreover, i t must be remembered that’ Cain and Miss Mickle-thwait 32 prepared a condensation product from tolidine and glyoxalwhich, although not crystalline, gave a nitrogen content correspond-ing with that required by the free condensation product.Furtherwork on this subject will be awaited with interest, because i t isapparent that more evidence is desirable before the Kauflerformula can be accepted.Triairylm e thyls.An admirable address on the triarylmethyls has appeared,33 inwhich the arguments for and against the conception of freeradicles are discussed, and in this connexion certain experimentsdescribed by W. Schlenk and E. Marcus34 are of importance.These investigators find that metals such as sodium or potassiumwill combine with the free organic radicles if the reaction is carriedout in ether solution in an atmosphere of nitrogen.Of the triaryl-methyls, only triphenylmethyl presented difficulties, which were,however, overcome, and sodium triphenylmethyl, CPh,Na, wasobtained as a brick-red mass very sensitive t o air. The structureof this substance follows from the formation of triphenylmethaneby the action of water or hydrochloric acid, and of triphenylaceticacid by the action of carbon dioxide. Methyl iodide and benzylLOG. tit., p. 2474.31 R. Reitzenbock, Alomtuk., 1913, 34, 199 ; A., 1913, i, 259.32 LOG. cit., p. 1441.33 M. Goniberg, J. Amcr. Chem. SOL, 1914, 36, 1144 ; A., i, 823.y4 Ber., 1914, 47, 1664 ; A,, i, 843.:j0 J.Kenner, T., 1913, 103, 615ORGANIC CHEMISTRY. 109chloride react at once, forming triphenylethane and as-tetraphenyl-ethane respectively.T?he Cinrmmic Acids.The explanation advanced by E. Biilmannss t o account f o r theoccurrence of three modifications of cis-cinnamic acid, namely, thatthe acid is trimorphous and can be isolated as allocinnamic acid(m. p. 68O), isocinnamic acid (m. p. 58O), and isocinnamic acid(m. p. 42O), is at the present time very widely held. H. Stobbeand C. Schonburg36 have now conducted a large number of experi-ments on the structure of these three acids, and have corm to theconclusion that they are, in reality, chemical isomerides. Thegeneral impression produced by the paper is that the experimentsdescribed can, for the most part, be explained on the Biilmanrhypothesis. It would appear desirable, before reopening this ques-tion, to frame some really adequate theory to account for morethan two stereoisomeric forms of cinnamic acid.Condehsa tion.Many papers have appeared during the period under review inwhich the formation of various types of condensation products isdescribed, but they deal, for the most part, merely with applica-tions of old methods to new conditions.Some, nevertheless, marka distinct step in advance; thus it has been found37 that manyacid chlorides condense with diphenylketen a t the ethylenic link-ing, forming condensation products, of which diphenylmalonylchloride, COCl-CPh,*COCl, formed from diphenylketen and oxalylchloride, may be taken as a type.The reaction does not appear,however, to have a very extended application, since only few acidchlorides react without yielding secondary products of indefinitestructure.The large number of compounds which are a t present knownhaving one or other of the alkali metals directly combined withcarbon, and which are therefore of considerable importance insynthetic work, has besen increased by the extension of the workof W. Schlenk and his collaborators on the formation of themetallic ketyls38 t'o a study of the conditions favouring the additionof the alkali metals to compounds containing the complexes C:C,C:N, and NzN.39 The reactions are carried out in ether solution,xj Ber., 1909, 42, 182, 1443; 1910, 43, 568 ; A ., 1909, i, 155, 382 ; 1910, i, 346.36 Annalev. 1913, 402, 187 ; A , , i, 173.57 H. Staudinger, 0. Gdliring, aid M. R. Schiiller, Rer., 1914, 47, 40 ; A., i, 285.38 W. Schlenk and A. Thal, A., 1913, i, 1205.3g W. Schlenk, J. Appenrodt, A. Michael, and A. Thnl, Ber., 1914, 47, 473 ;A , , i 396110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and appear to have a general application; thus, the C:C compound,stilbene, forms the disodium derivative CHPhNa-CHPhNa, thestructure of which is proved by the production of s-diphenylethaneby the action of water, and of the sodium salt of s-diphenylsuccinicacid when it is treated with carbon dioxide. The C:N compound,benzylideneaniline, yields the disodium salt,NPhNa*CHPh=CHPh*NPhNa,which with carbon dioxide gives the sodium salt of the acid,CO,H-NPh*CHPh*CHPh*NPh*CO,H.As a type of N:N compound, azobenzene was chosen, and in thiscase an equimolecular mixture of azobenzene and the dipotassiumderivative, NPhK-NPhK, was formed, from which the potassiumsalt, CO,K*NPh-NPh*CO,K, was produced by the action of carbondioxide.The work initiated by H.Stobbe on the condensation of cyclicketones with ap-unsaturated ketones has been extended 40 to include,the condensation of cyclopentanone and 3-methylcyclohexanonewith the ethyl esters of a-benzylidenebenzoylacetic acid anda-benzylideneacetoacetic acid. I n the case of 3-methylcyclo-hexanone, no condensation could be effected, but cyclopentanonecombines with ethyl a-benzylidenebenzoylacetate in the norinalmanner, yielding the compound I, whereas the condensationbetween the ketone and ethyl a-benzylideneacetoacetate yields ipcompound which is thought to be the bicyclic ketone, 11:An interesting condensation is described by M.Losanitsch,41 inwhich aldehydes and ketones are caused t o combine with saturatedlactones. The condensations are effected in ethereal solution inthe presence of alcohol-free sodium ethoxide, and may be illustratedby the formation of a-benzylidenevalerolactone,from benzaldehyde and valerolactone.The Grig~zurd Reaction.-The question as t o the possibility ofmore than one halogen atom, contained in the molecule of a react-ing substance, of combining with the Grignard reagents, has beeninvestigated by E.Votdek and J. Kohler,42 who find that pdi-iodobenzene yields pdi-iododiphenyl, benzene, and diphenyl, the‘O H. Stobbe, A. Schwyzer, aiid G. S. Crnikshnnks, J. pr. Chem., 1914, [ii], 89,184, 189 ; A., i, 540, 541.No?intsh., 1914, 35, 311 j A . , i, 693.42 Ber., 1914, 47, 1219 ; A., i, 763ORGANIC CHEMISTRY. 111formation of the last-named two substances being due to thedecomposition of ths dimagnesium compound, as shown by thefollowing scheme :I n t rani ol e cu la r Change.Whilst no new examples of the migration of atoms or groupshave been recorded during the present year, several of thosepreviously described have either been supported by further evidenceor have been confirmed by the isolation of definite intermediateproducts.The &figration of para-Halogen A toms in Phenols.-The dis-covery by P.W. Robertson43 that in the nitration of, for example,6-bromothymol (I), the nitro-group displaces the halogen atom,which then migrates to the ortho-position, thus :Br NO2/\'\/ CHI l:f13 /\CH3c 3 4 j 4OH OH(1.)has led to the investigation of other instances of the same kind.It is now found 44 that; whereas 6-bromo-4-nitro-m-cresol (11)behaves normally on nitration, 4 : 6-dibromo-m-cresol (111) yields2-bromo-4 : 6-dinitro-m-cresol (IV) :Br Br/\OH, + N02(/N02OH OHNO"(111.) UV.1The Migration of Acid R esidues.-The phenomenon of migrationof the acetyl group from oxygen to nitrogen during the reductionof certain acetylated azo-compounds has been established by K.v.Auwers and his collaborators. The migration seems $0 be affected,45 T., 1908, 93, 793 ; P. W. Robertson and H. V. A. Briscoe, ibid., 1912, 101,44 I. R. Gibbs and P. W. Robertson, i b i d . , 1914, 105, 1885.1961112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.or entirely hindered, by the' presence of certain groupings in theazc-molecule, and does not occur with the corresponding benzoylderivatives. I t has been shown4s that the presence of a substituentin either nucleus prevents the transformation except in oneinstance, in which a methyl group occurred in the para-positionof the benzene ruclms. Recent work46 shows that the ethyl groupin the same position also permits the migration.Aromatic from Hydroaromatic Substances.-The remarkabletransformation of a hydroaromatic compound into a true aromaticderivative which is illustrated by the formation of brominatedxylenols from dimethyldihydroresorcin by the action of phosphoruspentabromide,47 has been further investigated by A.W. Crossleyand Miss N. Renouf.48 It is evidently the intermediate compounddibromodimethylcyclohexenone (I), that gives rise t o the aromaticderivatives, since when this substance is treated with potassiumhydroxide ii; is converted into 5-bromo-o-3-xylenol (11) mixed withsmall quantities of 4 : 5-dibromo-o-3-xylenol (111) :C(C*,)2. CH3/\ /\OH,CH3c=*/ ,CH, --,Br!,,)OH t- BrC\/CO "'?/OH/\CH8CBr Br(11.1 (1.) (111. )The Beckmann Rearrangement.-J. Stieglitz and P. N. Leech 49put forward an explanation of the Beckmann change, which differsfrom that of Hantzsch in assuming that.a t on0 stage a compoundis produced containing a nitrogen atom having free residual valen-cies, thus:/H\ClCRRINOH + CRR':N-OH -+ CI1R':NCI: --+ CRC1:NR'The last substance then undergoes hydrolysis in the usuallyaccepted manner with the formation of an amide. This viewis based on the similar behaviour of triarylmethylhydroxyl-amines, for example, triphenylmethylhydroxylamine, CPh,*NH*OH,which on treatment with phosphorus pentachloride in etherealsolution is almost quantitatively converted into benzophenoneanilhydrochloride, CPh,:NPh,HCl.45 Annnlen, 1909, 365, 278 ; A . , 1909, i, 436.46 K. v. Auwers and F. Michaelis, Bcr., 1914, 47, 1297 ; A ., i, 747.47 A. W. Crassley and H. R. Le Sueur, T., 1903, 83, 110.48 T , 1914, 105, 166.49 J. Amer. Chem. Soc., 1914, 36, 2 i 2 ; A . , i, 268ORGANIC CHEMISTRY. 113Cdalyiic Beactions.Ths hydrogenation of diarylacetones and aryl alcohols has beeninvestigate'd by P. Sabatier and MI. Murat.50 Benzophenone and itshomologues readily undergo hydrogenation in the presence, ofslightly active nickel at temperatures from 300° to 350°, givingthe corresponding diaryl-hydrocarbons. A t lower temperatures andwith very active nickel, the aromatic nucleus also undergoes hydro-genation.A. Mailhe51 has prepared a number of new ketones by passingthe mixed vapour of several pairs of acids over ferric oxide a t470-480'. I n this way benzoic and phenylacetic acids yieldphenyl benzyl ketone, CH2Ph*COPh, acetic and anisic acids yieldaiiisyl methyl ketone, and so forth.The method, which can alsobe carried ou't in the presence of manganous oxide,52 seems to beof general application. It is pointed out53 that manganous oxidecan also be used with advantage in place of titanic oxide for thepreparation of aldehydes from the mixed vapours of formic withalipha€ic or arylacetic acids. An application of this cat$alyticmethod of condensation is also seen in the formation of certainether oxides of carvacrol.54 It is found, f o r example, that whenan equimolecular mixture of phenol and carvacrol vapours is passedover thorium oxide a t 470480°, phenyl carvacryl oxide is formed.An interesting observation has been made by E.Knoevenagel,55who finds that in the preparation of thiodiarylamines by the actionof sulphur on diarylamines, the addition of 0-05-2 per cent. ofiodine not only causes the reaction t o take place a t a lower tenipera-ture, but also yields a purer product, and considerably shortensthe time required for the completion of the reaction. A similareffect has been observed in the following reactions: (1) The forma-tion of arylnaphthylamines by the condensation of aromatic amineswith the naphthols and naphthylamines; (2) the alkylat'ion ofaniline and a-naphthylamine by the direct action of alcohols ;(3) anil-formation with ketones and aromatic amines; (4) sulphona-tion; and (5) oxidation.It has been found56 that the bromination of benzene proceedsa t a lower temperature in the presence of manganese, and that theratio of recovered benzene to brominated benzene is 8 : 9 in theLo Compt.rend., 1914, 158, 760 ; A . , i, 548.51 Bull. SOC. chiin, 1914, [iv], 15, 324 ; A . , i, 548.52 P. Sabatier and A. Mailhe, Compt. rend., 1924, 158, 830 ; A . , i, 547.53 Ibid., 985 ; A., i, 547.55 J. p r . Chem., 1914, [ii], 89, 1 ; A , , i, 519.5(i L. Gay, F. Dncclliez, and A. Raynaud, Conzpt. nmd., 1514, 158, 1804 ;54 Ibid., 608 ; A . , i, 403.A., i, 946.REP.-VOL. XI. 114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYpresence of manganese and 10 : 3 in its absence. Similar effectsare observed in the bromihation of toluene and the xylenes in thecold, but a t higher temperatures better results are obtained withoutmanganese.Ketones.The import'ant process for producing 1 : 2-diketohydrindene bythe hydrolysis of oximino-1-hydrindone by means of formaldehydeand hydrochloric acid 57 has now 58 been applied, with even betterresults, to the preparation of 1 : 2-diketo-5 : 6-dimet'hoxyhydrindene(I) and 1 : 2-diketco-5 : 6-methylenedioxyhydrindene (11) :(1.) (11.1These substances may very possibly find an application in solvingthe difficult problem of the synthesis of brazilin and its derivatives.An important addition to the number of desmotropic substancesrelated to the phthaleins has been made by 0.Fischer andE. KOnig,bQ who have succeeded in preparing a fluoran derivative,in both the lactlone and quinonoid forms, by the action of phthalicanhydride on 1 : 6-dihydroxynaphthalene.Since this substance,from its mode of formattion, must be derived from either an US- o ra Ba-naphthafluoran, and since it yields bisazo-dyes which do notdissolve1 in alkali, it follows that the lactone and quinonoid formsare represented by formula: I11 and IV respectively :HO/\ /\:0 Ho{\l 0 1 /\OH I I l O l I\/\/\/\/ \/\/\/\/I I I I\/'\/\/I I I I\/\/\/ c c:/\/ \C6H,*CO*0(111.)The lactone form is unstable, and can only be obtained colourlessin solution or, in solid form containing two molecules of thesolvent (C,8H,60,,2Et,0 ; C,,H,605,2COMe,, and so forth). Whendeprived of the solvent of crystallisation, it passes over into the redquinonoid form.A new method of methylatlion applicable t o aliphatic and hydro-57 W.H. Perkin, jun., W. M. Roberts, and R. Robinson, T., 1912, 101, 232.58 Ibid., 1914, 105, 2405.59 Bcr., 1914, 47, 1076 ; A., i, 712ORGANIC CHEMISTRY. 115aromatic ketones and esters of ketonic acids has been described.60The ketone is converted into the hydroxymethylene compound (Vj,which is t’hen reduced by hydrogen in the presence of colloidalpalladium to the methyl derivative (VI):-c:o --c: 0 -C:O -C:O-C:CH.OH -CH*CH,*OH --O:CH, - I - I-CH*CH, I 4 1(V.) (VI. )Owing to their importance in connexion with the production ofvat colouring matters, many new polycyclic quinones have beenprepared m d described. They do not call for any special mentionexcepting perhaps the compound (IX), t o which the name anthan-throne has been given.61 The structure of this substance is placedbeyond dispute by the fact that it is prepared both from l:l’-di-napht’hyl-8 : 8’-dicarboxylic acid (VII) and from 1 : 1’-dinaphthyl-2 : 2’-dicarboxylic mid (VIII) by the dehydrating action of sul-phuric acid:/\/\ /\/\ /\A.\/\/ \/\/\y) \/\/ I l l I l l 1 1 ICO,HH0,C C O P --+ ():I I I.f- I/\/\ \/‘/\ HO,C, /\/\ I , I l l I l l\/\/ \/\/ \/\/(VlI.) (IX.1 (VIII.)13enshydroZ.-A rQsum6 of the chemistry of this substance isgiven by J. Sabatier and M. Murat,62 who have attempted toprepare it by the action of water on the Grignard compound,CHPh,-OMgBr. They obtained, however, a yield of only 3 percent., the main products being diphenylmethane and s-tetraphenyl-ethane; since benzophenone is also formed, i t is assumed that thereaction is represented by the equations :3CHPh2*O€I = 2H20 + COPh, + CHPh2*CHPh,.2CHPh2*OH = R20 + COPh, + CH2Ph2.I n a later paper the same authors63 show that a nearly theoreti-cal yield of benzhydrol can be obtaine’d by the action of benz-aldehyde on magnesium phenyl bromide.It is of interest to note that benzhydrol derivatives containing asubstituted amino-group in the para-position are split by bromine,6o A.Kotz and E. Schaeffer, J. pr. Chent , 1913, [ii], 88, 604 ; A., i, 186 ;J. D. Riedel, D.R.-P. 266405 ; A., i, 186.L. Kalb, Ber., 1914, 47, 1724; A , i, 849.62 Compt. rend., 1913, 157, 1496 ; A., i , 168.m Ibid., 1914, 158, 534 ; A ., i, 404.1 116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.forming aldehydes and bromo-substitut,ed anilines.64 The reaction isprobably represented in the follo,wing manner :OH*CHPh*C,H,*NR, -+ O€€*CHPh*C6H4*NR2Br, -+OH*CHPh=NR,Br-C,H,Br -+ CHPhO + C,H,Br*NR2,HBr.Rupture of the Benzene Ring without Begmdcction.-The ruptureof the benzene nucleus which is illustrated by the formation ofacetylacrylic acid by the action of fuming sulphuric acid on 3-nitro-pcreso165 has been re-investigated by H. Pauly, R. Gilmour, andG. Will.GG They find that the acid C7H804, which is produced inthis reaction. is not acetylacrylic acid, but P-methyl-y-crotonolac-tone-y-acetic acid :QH: C hfe co---0 >CI€*CH,*CO,H.The course of the reaction is merely hydrolytic ; 3-nitro-pcresolreacts, in the first.instance, in its isomeric form, that is, as thenitrolic acid, and is hydrolysed t o the hydroxamic acid,CO,H*CH:CH*C?M&CH*C(OH):NOH.This is then further hydrolysed to hydroxylamine and P-methyl-inuconic acid, which subsequently passes into the lactone and water.The nitrogenous by-product, which is also formed,67 and has thestructure C7H,0,N, is regarded as 2-hydroxy-4-methylpyridine-6-carboxylic acid, and is formed from the hypothetical hydroxamicacid mentioned above by loss of water and ring closure.The Fission of Tertiary Bases.-The fission of tertiary bases a tthe nitrogen atom by cyanogen bromide which was studied by J. v.Braun,68 showed that the reaction was most marked when theamine contained a benzyl group.M. Tiffeneau and K. Fuhrer c9have now investigated the fission of bases by means of acidanhydrides and acid chlorides, and find that the fission can only beeffected in those cases in which the base has the structureAr*CH,-NRR’. The action is attributed to the intermediateformation of compounds of the type:A r- CH,,:Me CO -0':i)NAcRRlwhich undergo fission on heating in the manner shown by thedotted line.64 G. J. Essclen, jun. and L. Clarke, J. Amr. CJ~enz. Soc., 1914, 36, 308 ;65 G . Schultz and 0. Low, Ber., 1909, 42, 5T7 j A . , 1909, i, 222.66 AnnnZerL, 1914, 4403, 119 ; A., i, 485.67 G. Schultz arid 0. Low, Ber., 1910, 43, 1899 ; A., 1910, i, 552.68 B e y . , 1900, 33, 1438, 2728, 2734, 2965 ; A., 1900, i, 430, 641, 687.A., i, 278.Bull.Xoc. chim., 1914, [iv], 15, 162 ; A., i, 517ORGANlC CHEMISTRY. 117Carbon-ring Formation,A systematic study of this important question has been started,;Oand it is evident that we have still much to learn respecting theconditions which control t h e formation of cyclic compounds fromopen carbon chains. It is certain that whereas the Baeyer" Spannungstheorie " serves, and has served, as a good workinghypothesis, it is merely that and nothing more, since the tendencyto ring-formation exhibited by carbon chains depends not only onthe angle of the particuIar ring, but also to a very considerablee x t a t on the condition 'of the carbon atoms forming the chain.An admirable summary of some of the more salient facts, and alikely explanation is given by J.Kenner,71 but it is evident thatmuch work remains to be done before this question can be com-pletely answered. There can be no doubt that the presence in theopen-chain compound of a carbon atom which, in the resulting ringcompound, will be quaternary, has a marked influence against thetendency to ring-formation. There are numerous examples illus-trating the truth of this statement, and perhaps the simplest andbest is that given by L. J. Goldsworthy and W. H. Perkin,72 whopoint out that the yield of ethyl cyclopropane 1 : l-dicarboxylate (I)from ethylene dibromide and the sodium derivative of ethylmalonat'e is very small, whereas ethyl cyclopropane-1 : 2-dicarboxy-late (11) is readily prepared in good yield by a similar method:It follows, therefore, that rings containing a quaternary carbonatom ar0 relatively less stable than those in which a carbon atomof this kind is absent.This point is well brought out by Kenner,73and is also illustrated by the two compounds mentioned above,because, whereas ethyl cyclopropanel : l-dicarboxylate (I) is readilysplit by hydrogen bromide, the ester (11) is very stable towards thisreagent. It is interesting t o note that still another example of thiskind has been recorded during the year, namely, that given byA. Haller and R. Cornubert74 in the production of aa6-trimethyl-hexamide (IV) from 1 : 1 : 3 : 3-tetramethylcyclopentan-%one (III)by the action of sodamide:?H2*c'1e2>C0 + CHMe2*CH,*CH,*CMe,*CO*NH2.c H 2- c l\il e270I174(111.) (1 V.)L. J. Goldswortliy and W. H. Perkin, jun., T., 1914, 105, 2665.T., 1914, 105, 2685.Compt. rend., 1914, 158, 298 ; A . , i , 291.V2 LOC. cit. 73 LOG. cit., p. 2689118 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Cyclic Compii~nds from Ethyl GZutaconate.-The condensationc.f t'wo molecules of ethyl glutaconate under the influence of con-densing agents has been studied by E. E. Blaise75 and by H. v.Pechmann.76 The first-named, using sodium ethoxide a t 100°,obtained a compound which he considered t o have formula (I),whereas v. Pechmann and his collaborators, working in etherealsolution, obtained a compound to which either formula (11) or(111) was assigned :FH,*CO* CH (CO,Et)*CH : CH*CO,EtCH :CH*CO,E t(1.)CH(CH2*C0,Et)*C(C0,Et)>cHCH,<(-*--- CH( CO, E t)(11.)C B (C H, * COPE t) C (C02E t)>CH C02Et*CH<C3 ---CH,(111.)The two compounds melted a t much the same temperature, butapparently differed in some of their properties.It is now found77that the compounds prepared by the two methods are identical, andthat, of formulze I1 and 111, the latter is the more probable.The format'ion of ring structures by the spontaneous decomposi-tion of acid chlorides, which was originally investigated by W.Borsche and his co-workers,7~ has been extended79 to the prepara-tion of hydrindone derivatives. An example of this method, whichis of importance since it renders the use of aluminium chlorideunnecessary, may <be given in the formation of methylenedioxy-a-hydrindone (V) by the distillation of piperonylpropionyl(IV) :\ / \ A H 2 ++c*2(V.1CH2(IV.1chlorideHCI.It is sbated that, contrary t o the views expressed by others,*(' theelimination of hydrogen chloride in this manner is not greatlyinfluenced by the presence of phosphorus compounds.It is well known that the five-carbon ring is usually formed with75 E. E. Blaise, Compt. rcnd., 1903, 136, 639 ; A . , 1903, i, 400, 548.7~3 H. v. Pechmann, W. Bauer, and J. Obermiller, Ber., 1904, 37, 2113; A . , 1904,77 R. Curtis and J. Kenner, Y., 1914, 105, 282.78 Ber., 1911, 44, 2942 ; A . , 1911, i, 1018.79 W. Borsche arid W. Eberlein, zbid., 1914, 47, 1460 ; A., i, 699.i, 592.H. Leuchs, J. Wutke, and E.Gieseler, ibid., 1913, 46, 2200 ; A., 1913, i,855 ; H. Lecher, ibid., 2664 ; A . , 1913, i, 1166ORGANIC CHEMISTRY. 119the greatest ease and in the presence of the mildest reagents, butthat slight changes in the structure' of the1 open-chain compoundsometimes either hinder or entirely prevent the closing of thering. An instance of this kind is recorded by E. E. Blaise,81 whofinds that s-dipropionylethane (VI) is readily converted intol-met~hyl-2-ethyl-A~-cyclopenten-6-one (VII) by 10 per cent. aqueouspotassium hydroxide :CH,* CH, CH,*CH2I >co + 1 >coCH,*CH,-CO CH2*CH, C'H,*CH,*C==C*CH,(VI.) (VII.)whereas acetonylacetonel and acetoiiylacetophenone are quite un-changed under these conditions.Terpenes and Allied Compounds.Campheiiic A cid.-The structure assigned to this acid byAschan a2 has been verified by its synthesis.83 Ethyl cyclopentan-l-one-3-carboxylate (I) is condensed with ethyl a-bromoisobutyrate inthe presence of zinc, when ethyl 3-carbethoxycyclopentan-1-01-1-iso-butyrate (11) is produced.ThO elimination of water from thissubst,ance by the aid of potassium hydrogen sulphatel gives theethyl ester (111) of either 3-carboxy-A]- o r Akyclopentene-1-iso-butyric acid, and when the free acid from this is reduced byhydrogen and platinum black, dl-cis-camphenic acid, that is, 3-carb-oxycyclopentane-1-isobutyric acid (IV), is produced :7H2-- CH2>C0 + 7H2-- H 2 > ~ (0 H) c ~ e , . CO,ECH(C0, E t) C H, CH(CO,Et)*CH,(1.1 (11.)y 3 2 - Crf2>C*CMe2* C0,EtCH(CO,Et)*CH+ I CH,--- CH2>C€€*ClA!Ie2*C0,HCH(C0,H) CH, or7H2--- CH>C*C31e,* CO, E t C H( C0,E t) CH,( I JI.) (IT.1The synthesis of camphenic acid in this manner removes the lastdoubt as to the correctness of the Wagner formula for camphene.Wagner himself 84 suggested that the remarkable change from theborceol t o the camphene structure could be regarded as similar tothat which occurs in the pinacolin rearrangement. Meerwein g581 Compt. Tend., 1914, 158, 708 ; A., i, 546.s2 B?maZen, 1910, 375, 336 ; 1911, 383, 52 ; A., 1910, i, 709 ; 1911, i, 797.P. Lip", Ber., 1914, 47, 871 ; A . , i, 542.84 J. h!uss3. Plzy.?. Chcna. Xoc., 1899, 31, 680.85 Aitnnht, 1914, 405, 129 ; A., i, 850120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.CH-has now brought forward evidence which shows that this explana-tion is correct.He points out that the transformation of borneolinto camphene can be represented thus:(JJ CH (4) CH-CH, CH,-C-UH*O*SO, CH,*C-CH-OORGANIC CHEMISTRY. 121salt of this acid is distilled in a current of carbon dioxide r-fencho-camphorone is produced :YH,*YH*CH2*C0,H 7 H2* 7 K--yH2C'H2*CHoC02H UH,*CH--CO1 p e 2 --f I t)Me2IHydrocarbons Allied to the Terpenes.-A method has beendescribed 89 by which the action of the Grignard reagent on iiitrilesmay be utilised for the production of certain hydrocarbons alliedto the terpenes. Thus the condensation of 1-methylcyclohexan-3-one(VIII) with the sodium compound of ethyl cyanoacetate leads, inpart, to the formation of the cyano-acid (IX).Elimination ofcarbon dioxide yields the nitrile (X), from which by the action ofmagnesium methyl iodide the ketone (XI) is produced. Furthertreatment with the Grignard reagent then yields the terpineol(XII), which gives the hydrocarbon (XIII) on dehydration :CHMe*CH>C*CH,*CMe2*OH CH,<CH2-CH, CHRle*CH>c. CH: cJ$e2CH2<CH,-CE€2(XII.) (XIII.)Benaoterpenes.-A series of experiments has been started 90 withthe object of synthesising substances having a similar structure tothe terpenes, b u t containing an aromatic residue (XIV). It isthought that a study of these substances will help to eIucidate theproblem of the structure of the sesquiterpenes, since the relation-ship between naphthalene and the hydroaromatic sesquiterpenes isshown by the following formulze:5=3 7H3CH CH QH CH CH2 CCH/\C/\CH CH/\C/\FH, C H , * C H / \ ~ / \ C EI ICH,CH\j/h\#X€ CH CH CH(\,k!\,CH2 CH $!H CH2\/CH\/ CH,CH(CH,), CH,*C:CH,Naphthalene. Ben zo-p-men thane.a-Selinene.(XIV. )39 W. N. Haworth and A. W. Fyfe, T., 1914, 105, 1659.9O F. W. Kay a i d A. Morton, ibid., 1565122 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It is open t o question whether any useful purpose is served bygiving the name henzo-p-menthane to a substance which is obviouslya h u e derivative of tetrahydronaphthalene.Various Reactions.The tendency to the formation of hydroxy-anhydrides (6-hydroxy-a-pyrones) from glutaconic acid and some of its derivatives, whichwas described by N.Bland and J. F. Thorpe,gl has been shown byW. DieckmannQ2 to be exhibited also by homophthalic acid (11).A comparison of the hydroxy-anhydrides of homophthalic acid andglutaconic acid (I) shows that both yield yellow neutral salts withalkali, but that the anhydride from homophthalic acid gives nocolour with ferric chloride and does not absorb bromine. I n thefree state it has, therefore, the normal structure (111):CH CH(1.1 (11.) (111.)Homophthalic acid is therefore comparable with, for example,aP-dimethylglutaconic acid 93 (IV), which, although it yields ananhydride that dissolves in alkali, does not give a coloration withferric chloride, and thus according t o Dieckmann should, in thefree state, have the structure V I :,CH,*CO,HCH,$CH,*C\CO,HCHCOCH,*C 0co \/(IV.) (V.) (VI.1There is, of course, a fallacy in Dieckmann’s argument, for if theanhydride of glutaconic acid has the enol structure because i t givesa yellow sodium salt and a coloration with ferric chloride, why isthe free anhydride colourless? This error is apparent in a greatdeal of the work that has been done recently on keto-enol tauto-merism. I t has been too hastily assumed that, because the ferricchloride and bromine-absorption reactions serve as excellent meansfor distinguishing between the keto and enol forms of certain types,therefore, when compounds fail to respond t o these tests, theabsence of the enol modification is proved. It must be remembered91 T., 1912, 101, 863.93 F.B. Thole and J. F. Thorp, T., 1911, 99, 2216.92 Ber., 1C14, 47, 1428 ; A . , i, 690ORGANIC CHEMISTRY. 123that, of the two isomeric phenols thymol and carvacrol, onlycarvacrol gives a coloration with ferric chloride, and there are,O HCarvacrol.OHThymol.moreover, numerous other examples which show that whereas apositive ferric chloride reaction is a sure indication of the presenceof the enol variety, a negative result does not necessarily showits absence.Reduction of the Carboizyl Group.-The valuable method for thereduction of aldehydes and ketones which was introduced by E.Clemmensen94 has now been improved and extended.95 The methodpromises to be of special service in the preparation of homologuesof the various phenols from hydroxy-ketones, and although its valuefor the reduction of hydroxy-aldehydes is diminished by the sensi-tiveness of many of these compounds towards hydrochloric acid, themethyl-substituted phenols obtained are of a high degree of purity.The ketones are reduced by amalgamated zinc in the presence ofhydrochloric acid, and the applicability of the method is illustratedby the production of numerous substituted phenols from the corre-spofiding ketones ; thus p-hydroxyacetophenone yields p-ethyl-phenol, m-acetyl-o-cresol gives 2-methyl-4-ethylpheno1, acetylquinolis reduced to ethylquinol, and so forth.Bsterification b y Ultm-violet Light.-It has been noticed duringthe course of certain experiments having f o r their object the trans-formation of stereoisomerides by ultra-violet light,g6 that alcoholicsolutions of certain acids undergo esterification when exposed tothese rays.Thus benzoic acid is esterified to the extent of 30 percent. in eight days, and t o the extent of 56 per cent. in the sametime when a trace of hydrochloric acid is present.Phototropy and Thermotropy.-That trituration or rubbing iscapable of producing polymorphic change and is an importantmeans of bringing about chemical reactions is well known, and thepaper recently communicated by L. H. Parker97 not only adds toour knowledge of this subject, but also contains a useful list ofreferences to previous work. The principle has now been applied98to a number of 4-hydro~ybenzylidenearylamines~ the general94 Ber., 1913, 46, 1837 ; A ., 1913, i, 733.95 E. Clemmensen, ibid., 1914, 47, 51 ; A., i, 271.96 R. Stoermer and H. Ladewig, ibid., 1803 ; A . , i, 966.97 T., 1914, 105, 1504.98 A. Senicr and R. B. Forster, ibid., 2462124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.results of which may be described by referring to those obtainedwith 4-hydroxybenzylideneaniline, OH*C,H,*CH:N*C,I3,. Thissubstance is dimorphous ; trituration changes it into a deeper-coloured dimorphic variety, which? however, on long keepingreverts t,o the original compound. The paler-coloured variety isthermotropic, becoming paler a t ‘‘ the lower temperature ” (that is,of solid carbon dioxide9, and returning to the original colour a t theordinary tlemperature. The deeper-coloured variety is not photo-tropic, but on prolonged exposure to sunlight changes to a brown,polymorphic form.J.F. THORPE.PART III.-HETEROCYCLIC DIVISION.IN former years, the task of the reporter was rendered difficult bythe great mass of material from which it was necessary to selectthose subjects which lent themselves best to summarisation inbrief; but in the current Report this embarrassment has not beenso great as usual, f o r only the first seven months of the year’s workare covered by the Austrian and German journals in our possession,so that the amount of published matter to be dealt with isless than in any previous year. This has necessitated a choicebetween two policies, for it was possible either to make the Reportof the customary length by including various pieces of work ofless importance, or t o reduce thO length of the Report to someextent and keep its standard approximately the same as in othervolumes.The latter objective has been chosen, as it seems themore desirable of the two, so that the present Report remainscomparable with its forerunners.Last year saw the close of the main investigations on the con-stitution of chlorophyll, and in the period covered by this Reportit cannot be said that much more light has been thrown on thebroad outlines of the problem. The work of the year in this par-ticular field has taken a fresh turn, and t.he researches of variousinvestigators have been directed towards the occurrence of chloro-phyll in various plants, and the reactions of chlorophyll quachlorophyll, rather than those of its decomposition products.I nfact, it may be said that chlorophyll a t present is falling backfrom the centre of the chemical stage and giving place to othersubjects of interest.The same holds good with regard t o the chemistry of the bloodpigment. Great advances in our knowledge of this substance weremade in 1913, but the last twelve months have left the main quesORGANIC CHEMISTRY. 125tion very much where i t was, and have been spent in that slowand laborious work which marks the accumulation of data thatare necessary before a further advance is possible. This amassingof isolated facts does not lend itself to reproduction in connectedform, so that in the present Report only a brief mention is madeof some points; but it must be borne in mind that; those fieldswhich have been selected for treatment represent only a smallfraction of the work accomplished in the twelvemonth, and it mustnot be assumed that the investigation of haemin is approaching astandstill.Haemin and chlorophyll having thus passed into a new stage oftheir chemical career, we turn to, another field to find the subjectwhich promises to take their place.From the developments whichhave recently occurred, it appears likely that this will be foundin the study of the pigments of plants and flowers. I n fact, as faras the heterocyclic series is concerned, this year has been markedby a greater advance in this direction than any which have takenplace in other branches of the subject.Willstatter and hiscolleagues have not only broken new ground, but have alreadyestablished the main lines along which further advances can bemade, and, what is even more encouraging than the success of asingle school, many other workers have been drawn into the fieldin questmion, so that i t appears certain that our knowledge of itwill soon progress both extensively and intensively.These developments in the study of chlorophyll, hzemin, and theplant pigments appear to mark the recrudescence of organicchemistry proper, in contradistinction from what may be termedthe chemistry of the carbon compounds. Thus pure chemistry andphysiological chemistry are again tending t o become more closelyallied than they have been since the earliest days of modernchemical history, and this approximation appears one of the mosthopeful signs in present-day science.Under the conditions exist-ing in living organisms, many reactions take place a t the ordinarytemperature which in the laboratory can only be brought aboutby the use of active reagents and the application of heat, and itseems possible that the coming years may see determined attemptsto reproduce these reactions under conditions more similar to thosewhich suffice for the syntheses of compounds within vital tissues.Turning now to fields of less general interest, the investigationsof haemin and chlorophyll have necessitated a closer investigationof the pyrrole group, and a considerable amount of work has beencarried out in this branch of the subject during the year, althoughmuch of it is too det'ailed to summarise in these pages.The chemistry of the alkaloids has not been marked by an126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.great advances, but rather by a steady accumulation of know-ledge upon minor points, which will serve its purpose later on.New syntheses of coumarin and thiophen have been devised, ofwhich the latter is important, as it permits of the substance beingobtained in quantity with ease, and it seems likely our knowledgeof the thiophen group may soon increase considerably.Anotherpoint t o which attentmion might be drawn is the discovery thatpyridine acts on many sulphur compounds catalytically, so that itis a solvent that must be utilised with caution for substances ofthis type.Surveying the heterocyclic group as a whole, it cannot be saidthat the year has been by any means an unsatisfactory one asregards research in this division of the subject.Cyclic Compounds the Rings of which coiztain Mercury Atoms.The number of elements which have hitherto shown a tendencyto act as members of heterocyclic rings is comparatively limited, andi t is therefore of some interest to find that this year has brought anincrease in this class.Not only do we find mercury atoms play-ing the part of ring-members in the case of substances such asN H,OAcso, -in which the heterocycIic ring is produced by a kind of internalsalt-formation, akin to the betaine or lactone structure, but com-pounds have been synthesised which are mercury analogues ofpiperidine or penthiophen, and in some cases more than onemercury atom occupies a place in the ring.1The preparation of the dimercuri-compounds begins with the pro-duction of a Grignard reagent from m-dibromopentane.Themagnesium compound is then treated in ethereal solution with dry,powdered mercuric bromide, and by this means penbamethylene-a€-dimercuridibromide is quantitatively formed. I n this coni-pound, the mercury atoms are very firmly attached to the rest ofthe molecule, whilst the halogen atoms are extremely reactive, sothat the corresponding iodide, nitrate, or hydroxide can be obtainedfrom the dibromide.The dibromide is also attacked by either hydrogen sulphide o racetylene, yielding compounds the simplest formulz of whichwould beR.Hrieger and W. Schulem~iin, J. pr. Cheqn., 1914, [ii], 89, 97 ; A . , i, 611ORGANIC CHEMISTRY. 127but as the molecular weight of these has not been ascertained, itis possible that they are polymerides.2The bromine atoms are also replaceable by dibasic acid radicles,and in this wag rings containing a very large number of atomscan be produced; for example, azelaic acid yields an eighteen-membered ring.The action of magnesium phenyl bromide on the mercuribromideresults in the production of pentamethylene-aedimercuridiphenyl,Ph*Hg* [CH,],*HgPh, a representative of a mixed mercury dialkyl.Turning now to the problem of preparing cyclic compounds con-taining only a single mercury atom in the ring, it cannot yet besaid that this problem has been placed beyond doubt, for themolecular-weight determinations seem t o have been unsatisfactory,so that we cannot be certain that the substance produced has theformula I and not 11:The compound was prepared by the action of sodium amalgam ona€-dibromopentane. It appears t o polymerise readily, thus show-ing an analogy to some cyclic compounds containing oxygenand sulphur atoms in the ring.Its most characteristic reaction isshown when it is treated with iodine, dihalogenopentanes andpentamethyleneaedimercury haloids being formed.Thiopken and some of its Derivatives.Hitherto the synthesis of thiophen has been a somewhatlaborious one, but a new process has recently been discovered3whereby it, may be produced in large quantities with the minimumof trouble.Pyrites is heated at about 300° in a tube throughwhich acetylene is passed, and i t is found that about half theproduct is thiophen, which can easily be purified from theby-products of the reaction. The essential condition for success isthe employment of the pyrites in a very finely powdered state.When the apparatus is working properly, it is possible to preparemore than 300 grams of thiophen per diem.The substitution of isoprene or Py-dimethyl-il"y -butadiene foracetylene gives rise to 3-methylthiophen and 3 : 4-dimethylthiophenrespectively, but the yields are very poor.4The nitration of thiophen has been studied, and it is found thatwhen t,hiophen dissolved in acetic anhydride is nitrated at 0-5Oby means of nitric acid (D 1-52) dissolved in acetic a.nhydride (airS. Hilpert and G.Griittner, Ber., 7914, 49, 177, 186 ; A., i, 261, 262.W. Steinkopf and G . Kirchhoff, An?zaZcn, 1914, 4103, 1 ; A . , i, 425.TIr. Steinkopf, ibid., 17 ; A . , i, 426128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.being drawn through the mixture during the operation), the pro-duct is 2-nitrothiophen in a 70 per cent. yield.From the nitrothiophen thus formed, the corresponding amino-thioqhen can be obtained by reduction with tin and hydrochloricacid. It is not very stable, for in the presence of a trace ofoxygen it polymerises, and subsequently undergoes oxidation.The action of mercuric chloride on thiophen gives rise t o bothmono- and di-mercurichlorides. Investigations have now been seton foot to discover the influence on the reaction which is exertedby substlituents in the thiophen nucleus.5 When both a-positionsof the thiophen ring are free, it is possible to obtain a dimercuri-derivative as well as the mono-compound, but if one a-position beoccupied by a substituent, then, as a general rule, only the mono-mercurichloride is produced.When both the a-positions in thethiophen ring are substituted, the results of the reaction aredifferent, for in some cases the end-product is an additive compoundcontaining a mercurichloride group in position 3, whilst in otherinstances no interaction a t all takes place between the substitutedthiophen and the mercuric chloride.These rules are evidentlysubject to exceptions, and do not furnish us with a trustworthymethod of differentiating between isomeric thiophen derivatives.Thiophen-2-mercurichloride reacts with soldium in boiling xyleneto form mercury 2 : 2/-dithienyl, Hg(C,H,S),.This work has led to an interesting discovery of a method bymeans of which thiophen ketones can be prepared. Thiophenis allowed to react with mercuric chloride, producing thiophen-2-mercurichloride. By the action of acetyl chloride on the lattersubstance, 2-acetylthiophen is formed and mercuric chloride iseliminated. I n this way, a small quantity of mercuric chlorideshould suffice t’o convert a large quantity of thiophen into theketone, and a reaction somewhat akin to the Friedel-Crafts’synthesis has been discovered.The yields obtained are good, andthe reaction appears t o be generally applicable.A compound of some interest has been synthesised which con-tains a thiophen nucleus condensed with a pyridine ring.c Themethod of preparation is a modification of Skraup’s quinolinesynthesis, 2-aminothiophen being substituted for aniline and2-nitrothiophen being used instead of nitrobenzene. The yield isa poor one, 5-7 per cent. of pyridino-2: 3-thiophen (I) beingDroduced :(1.15 W. Steinkopf and M. Bauermeister, Annalen, 1914, 403, 50 ; A . , i, 427.W. Steiiikopf and G. Liitzendorf, ibid., 45 ; A., i, 432ORGANIC CHEMISTRY. 129The substance is a yellow liquid resembling quinoline in its odourand in some of its reactions.A Sywthesis of Coumarin.When a mixture of o-chlorobenzylidene chloride, acetic acid, andpotassium acetate is heated a t 210-220°, the product of the re-action is o-chlorocinnamic acid.This compound, by electrolyticreduction, can be converted into o-chloro-P-phenylpropionic acid,which, in turn, by heating with sodium hydroxide and water a t250°, is changed into melilotic acid (I) :0(1.1 (11.)Distillation of this substance produces the corresponding internalanhydride (11), and by passing bromine vapour over the last-named substance a t a temperature of 270-300°, two atoms ofhydrogen are removed in the form of hydrogen bro,mide, andcoumarin is produced.'The Condensation Products of PhloroglucinoE and Aldehydes.When three molecular proportions of phloroglucinol are con-densed with two of an aldehyde, two molecular proportions of waterare eliminated, but a careful examination of the products showsthat in actual practice two reactions are taking place side by side,with the production of two different end-products.* The state ofaffairs may be expreesed in the following manner :Reaction I.1 mol. Phloroglucinol + 1 mol. Aldehyde - 1 mol. Water.,, 11. 2 mols. ,, -1-1 mol. ,, -1 mol. ,,Total effect. 3 mols. ,, +2 mols. ,, - 2 mols. ,?The course of the condensation is much affect'ed by the conditionsemployed and by the nature of the condensing agent used. Theinitial condensation products are colourless and amorphous, but ifthey are kept in contact with the mother liquor a further elimina-tion of water takes place, and red compounds are obtained.Thuswhen /3-hydroxybutyraldehyde is condensed with phloroglucinol bymeans of dilute sulphuric acid a t about 6O, the product has thecomposition C,,H1204, and appears to have the structureH. Meyer, R. Beer, and G. Trasch, Monatsh., 1913, 34, 1665 ; A . , i, 44.8 I?. Wenzel, ibid., 1915 ; A , , i, 75.REP.-VOL. XI. 130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.This substance is deposited from the solution in snow-white flocks,which turn to a pale yellow powder on drying; but, if i t is allowedto remain in contact with sulphuric acid for a t h e , it loses asecond molecule of water and yields a red substance, which appar-ently has the structure represented byThe reaction appears to be a fairly general one, being applic-able even in the case of ths monosaccharoses and phloroglucinol.Thus I-xylose can be condensed with dimethylphloroglucinol inpresence of hydrochloric acid t o form a deep brownish-red sub-stance, which appears to have the structure represented bySome of thesesalts with acids.compounds appear to yield well-defined oxoniumDerivatives of Dime t hylpyrone.Owing to the ease with which dimethylpyrone hydrochlorideappears to become hydrolysed when i t is dissolved in water, thereseems to be some doubt as to whether it8 aqueous-solution actuallycontains the true salt of the base or merely a mixture of the baseand acid.To throw light on this question, the concentration ofthe chloride ion has been determined in solutions of differentstrengths by measuring the potential of the electrode Hg I solidHg,Cl,, solution of dimethylpyrone hydrochloride, against aN / 10-calomel electrode.Similar measurements were made withvarious solutions of hydrochloric acid. The equivalent conductivi-ties of all the solutions were also measured, and on plotting thevalues of the chloridion concentrations as abscissa: against the equi-valent conductivities as ordinates, it was found that the curve fordimethylpyrone hydrochloride lies below that f o r hydrochloric acid,both curves approaching the same value f o r infinite dilution. FroORGANIC CHEMISTRY. 131this it is deduced t'hat dimethylpyrone hydrochloride exists insolution as a true salt, although it is hydrolysed to sonie extent.$1)iniethylpyrone forms a large number of additive products withacids, phenols, and nitrophenols.10 By means of the cryoscopicmethod, the existence and nature of these substances has beenascertained, and it is found that they may be divided into threeclasses, having respectively the compositions :C7H,02,HX 2C7H,0,,3HX C71'I,0,,2HXThe additive compounds are well crystallised, and as a general ruletheir melting points are lower than those of their components.Thereaction between the dimethylpyrone and the &her reagent appearst o be ionic, and the additive compounds seem to be true oxoniumsalts.Some arylidene dehatives of dimet(hy1pysone 11 have been pre-pared which form intenseIy coloured salts with acids.It is con-cluded that acidic or weakly basic pyrones possess structurescontaining a bridge formed by the oxygen of the carbonyl group, assuggested by Collie, whilst the arylidenepyrone derivatives areassumed to possess the ordinary unbridged pyrone structure.Iitdiyo and its Allies.A considerable amount of work has been carried out on the indigoderivatives, and some reference must be made to the more importantbranches of this subject.New syntheses of indigotin12 have been devised, and methods ofpreparing substituted indigotins have been studied.13 It has beenshown that experimental conditions have a marked effect on theaccuracy of titration of indigotindisulphonic acid with potassiumpermanganate.14 The amount of the permanganate requiredappears to be about 12.6 per cent.less than the theoretical quan-tity. Efforts have been made t o track the source of this error,and i t has been found that an addition of manganese sulphatediminishes the difference between theory and practice, whilst thepresence of a large excess of sulphuric acid also helps to eliminatethe error. Almoet theoretical results are obtained when the0 13. N. K. R$rdarn, Oversigt. K. Dnnske. Yidensk. Sslskabs. Forhandl., 1914,lo J. Kendall, J. Amer. Che?n. Xoc., 1914, 36, 1222 ; A., i, 858.l1 A. A. Boon, K. J. McKenzie, aud J. Trotter, P., 1914, 30, 205 ; A. A. Boon,la W. Madelung, Annalen, 1914, 405, 58 j A , , i, 737.1Y A. Reiesert, Ber., 1914, 47, 672 ; A., i, 432 ; E. Grandmougin and P.Seyder,ibid., 2365 ; A., i, 1142 ; H. Levinstein, J. SOC. Clmn. Ind., 1914, 33, 574 ; A , , i,876 ; M. Tschilikin, J. Russ. Phys. C'hmt. Soe., 1913, 45, 1834 ; A , , i, 191.K 2243 ; A., i, 1173.F. J. Wilson, and I. M. Heilbron, T., 1914, 105, 2176.l4 H. E. Wagner, J. pr. Chem,, 1914, [ii], 89, 377 ; A. i, 875132 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.indigotin solution is added drop by drop to a feebly acid perman-ganate solution, whilst rapid addition results in too great aquantity of permanganate being used.It has been found that l-substituted isatins can be obtained bythe intramolecular condensation of oxamyl chlorides of the typeCl*CO*CO*NRPh; in some cases the reaction can be broughtabout by the direct interaction of oxalyl chloride and an amine inthe presence of aluminium chloride.Thus oxalyl chloride andethylaniline produce l-ethylisatin.16Flavones and Flavonols.The interaction between phenols and ethyl acetoacetate canfollow two very different linee according t o the conditions underwhich i t takes place. On the one hand, coumarin derivatives areobtained, whereas if phosphoric oxide is used instead of sulphuricacid the main products are chromones.16 The latter reaction hasnow been applied to the preparation of several substances whichhad previously been synthesised by other methods. I n the caseof the condensation of resorcinol with methyl methylacetoacetate,no difficulty was experienced in preparing 7-hydroxy-2 : 3-dimethyl-chromone. When the reaction was carried out with ethyl aceto-acetate and phenol, however, no corresponding end-product wasobtained.To account for this, it seemed possible that the presenceof the phenol had converted the ethyl acetoacetate entirely intothe ketonic form, and in order to avoid this, the sodium derivativeof ethyl acetoacetate was employed in the reaction instead of theester itself. The results in this case were normal, a condensationproduct being readily obtained.The way was now clear to utilise ethyl benzoylacetate in placeof ethyl acetoacetate, and the product of the reaction was flavone:0/\/OH /\/\g* C,H, I I H*-g*C6H, --+ I I + R*OH+H,O. \/\P" coRO-COThus a new and simple synthesis of this compound has been found,which may in time prove to be a general method for the prepara-tion of various flavone derivatives, whilst alkylated chromones canalso be obtained in the same manner from suitable reagents.17On the other hand, the method of synthmis discovered byl5 R.StollB, Ber., 1913, 46, 3915 ; A., i, 198.l6 H. Siinonis and P. Remmert, ibid.) 1914, 47, 2229 ; A., i, 980.l7 H. Siinoiiis and C. B. A. Lehmann, ibid., 692 ; A , , i, 424ORGANIC CHEMISTRY. 133Auwers and Muller,l* by which, for instance, the dibromide ofbenzylidene-4-methylcoumaran-3-one is converted into 6-methyl-flavonol by treatment with hot alcoholic potassium hydroxide, hasbeen proved19 to be incapable of general application. It is especi-ally unfortunate that it appears to break down in those cases wherethe production of naturally occurring flavonols might bO expected.Some work of considerable interest has been carried out in thequercetin group of dyes.20 These substances in general yield colourswhich range from yellow to brown, but i t seemed possible that, byintroducing suitable auxochrome groups into the molecules, adeepening of the tints might be effected which would provide red,violet, or blue colours having the fastness of the original dye.The choice of the auxochrome groups suit'able for producing therequired result is not so simple as i t appears a t first sight.I n thealizarin seriea, the hydroxyl radicle has proved a valuable auxo-chrome, but its effect in the flavone group does not appear to be sopowerful, for there is very little change in tint in passing fromluteolin through quercetin t o myricetin, although the second com-pound contains an extra hydroxyl radicle, and the last one hastwo more hydroxyl groups than are present in luteolin.Neverthe-less, the endeavour was made to introduce an additional hydroxylgroup into the quercetin molecule, for the possible results extendedinto more than one field. I n the first place, the action of an auxo-chrome is influenced by its position in the molecular structure,so that i t seemed quite likely that if the fresh hydroxyl radiclebecame attached to the ring in certain positions, it might exert amore marked effect than had been observed in other cases. Further,the synthesis of a new hydroxyquercetin might help to throw lighton the structure of the other hydroxyquercetin derivatives such asmyricetin, gossypetin, o r quercetagin.The first steps were taken by the complete methylation of thequercetin molecule with a view to protect the hydroxyl radicles init.Thereafter, the methoxylated substance was nitrated, the nitro-group reduced, and the compound finally demethylated. I n thisway 6/-aminoquercetin was obtained. Examination of its propertiesshowed that as a dye it did not differ much in tint from quercetinitself, so that the auxochromic action of the amino-group was evi-dently insufficient to produce the desired result. An attemptwas then made to diazotise the amino-compound, but it was notfound possible to displace the amino-group by hydroxyl.A curious point came to light, in the course of the investigation.lx K.v. Auwers and I<. Miiller, Ber., 1908, 41, 4233 ; A . , 1909, i, 45.19 K. v. Auwers and P. Pohl, Annalen, 1914, 405, 243 ; A., i, 981.l3. R. Watson, T., 1914, 105, 338134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Quercetin itself yields a series of bright yellow oxonium salts, butthe progressive introduction of methyl groups appears t o renderthe stability of such salts much less marked. Thus quercetin tetra-methyl ether forms only a very unstable sulphate. On the otherhand, when a fifth inethyl group enters the molecule the power ofoxonium-salt formation reappears in full strength, for the penta-methyl derivative of quercetin gives rise to several quite stable saltswith mineral acids.These substances are bright yellow, and itseems probable that they have a quinonoid structure of some typesuch as:0 OMeI 1 ‘CmOMe\,/ \c1Meo/\/\c-/=Lo( CH,\A//Me0O HWhen exposed t o air, the salts acquire a surface tint of bright red,for the occurrence of which we have a t present no explanation.The foregoing methods having failed t o produce a deeper-coloureddye, various other attempts were carried out.21 The intermediatecompound, 6’-nitroquercetin pentamethyl ether was partly demethyl-ated, yielding 6’-nitroquercetin dimethyl ether ; but this was found t obe useless for dyeing purposes. Various attempts t o introduce addi-tional auxochromes failed, and the multiplication of chromophoricgroups in the molecule also gave rise to unsatisfactory results.The objective sought wast o introduce into the molecule some substituent which wouldproduce a permanent quinonoid structure, and this was gained byreplacing the pyrone ketonic radicle by the group *CR*OH.Thenew compounds of this type might be expected to resemble inbehaviour the dyes of the triphenylcarbinol series. Compounds ofthe following structure (I and 11) were therefore prepared by theaction of Grignard’s reagent on quercetin pentaethyl ether andsubsequent de-ethylation with hydriodic acid. The base corre-sponding with I1 dyes wool violet o r crimson, according as t owhether alum or tin is used:Success was attained in another way.OH T Il0 OEt 0EtO 7 HO 7Et Et(1.) (11.)21 E. R. Watson and K.B. Sen, T., 1914, 105, 389 ; compare R. Willstatterand H. Mallison, Sitxungsber. K. Akad. Wiss. Berlin, 1914, 771 ; A., i, 1081ORGANIC CHEMISTRY. 135Plant Pigments and Allied Materials.Last year saw the beginning of a systematic investigation of thecolouring matters of various flowers, and although the resultsobtained a t first were meagre, they have now been considerablyextended. The earliest work dealt with the pigment which givesits colour to the cornflower,22 and this compound was obtained in apure, crystalline form, which permitted a chemical investigationof its nature. The results attained tend to show that the antho-cyanins, as these pigments are' termed, belong to a class of basicveget'able, compounds which owe their basicity to an oxygen atom.The new class of pigments differs from the better known flavonedyes in that the latter form only easily dissociated salts with acids,and therefore do not occur as oxo,nium salts in the plants fromwhich they are derived; the anthocyanins, on the other hand, cancombine with acids t o yield comparatively stable oxonium deriv-atives, somewhat akin to those of phenopyrylium 23 :An examination of the cornflower pigment, cyanin,24 has thrownlight on the problem of the colour variations which are found inthe flowers.Apparently there are three main forms in which thecompounds can exist. When combined with mineral acids o r theacids of plants, the anthocyanins are red in tint. Neutralisationof the acid causes a change of colour to violet, and it seemsprobable that the violet type of compound is an internal salt akinto the phenolbetaines, and contains the group:>c-o-o<The addition of alkali produces blue alkali salts, which are to beregarded as derivatives of the neutral violet forms in which nochange has been effected in the internal oxonium salt complex.Thus, what a t first sight appear to be three distinct' colouringmatters are merely modifications of one primary structure underlocal variations in the distribution of acid and alkali throughoutthe plant tissues.The earlier investigations of these pigments led to the proof that22 R.TVillstatter am1 A. E. Everest, Annalen, 1923, 401, 189 ; A . , 1913, i, 1371.H. Decker and T. von Fellcnberg, ibid., 1908, 364, 1 ; A., 1909, i, 116 ;compare also H.Decker and P. Becker, Ber., 1914, 47, 2289 ; A., i, 1082.24 R. Willstatter, Sitxzcngsber. K. Akad. Wiss. Berlin, 1914, 402 ; A., i, 564136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the colouring matters are present in the plants in the form ofglucosides, so that this chemical class has been found in a hithertounsuspected field.Hydrolysis of the pigment of the cornflower leads t o its decom-position into two molecules of dextrose and one molecule of theactual colouring matter, which has been termed cyanidin. Thelatter substance has now been shown to have the compositionC15Hl106Cl. The previous estimate of its composition has beenfound t o be erroneous on account of the specimen not having beenentirely freed from water, which apparently is very stronglyretained by the compound.The anthocyanin which is present in the rose (rosa gallicu) isa diglucoside of cyanidin, whilst the pigment of the cranberry iscomposed of one molecule of galactose combined with one moleculeof cyanidin.From this i t will be seen that cyanidin is very widelydistributed in nature.Several other anthocyanins have been investigated. Thus grapesowe their colour t o the anthocyanin oenin; bilberries are colouredby the compound myrtillin; and, in addition to these, delphininand pelargonin have been purified.The methods of extracting the colouring matter naturally varyaccording t o the plant which is used as a starting material, but theessential part of the process is the formation of a sparingly solubleoxonium salt.I n the case of grapes, the skins are extracted withglacial acetic acid a t the ordinary temperature and the dark redfiltrate is precipitated with ether. From the deposit thus obtaineda picrate is prepared, and by this means the pigment is purified andthe anthocyanin itself obtained. When bilberry skins are workedup, the process is different. The extraction is carried out with a1 per cent. alcoholic solution of hydrochloric acid; the liquor thusobtained is precipitated with ether, and the pigment is removedfrom the precipitate by means of water. By the addition of con-centrated hydrochloric acid and cooling of the solution, the antho-cyanin chloride is precipitated in an almost pure condition.The investigation of the anthocyanins is rendered difficult bythe fact that they are not very stable substances.Aqueous oralcoholic solutions of the pigments gradually lose their colour, insome cases with great rapidity. This alteration in colour does notappear t o be due t o a reduction of the pigment, but is t o be attri-buted t o an isomeric change similar t o that which takes place whena triphenylmethane dye is converted into the corresponding car-binol. It has been found that the decolorisation can be delayed bythe addition of salts such as sodium chloride, and the addition ofexcess of mineral acid stops i t completely. Further, a cyanidiORGANIC CHEMISTRY. 137solution which has become decolorised can be restored to its originalcondition by the addition of acid.The absorption spectra of the anthocyanins closely resemble oneanother; in acid solution they all show a broad absorption band,which extends over the green and blue regions of the spectrum.Hydrolysis of the anthocyanins produces the correepondinganthocyanidins, which in general resemble each other, althoughthey differ to some extent in crystalline form, solubility, andcolour-reaction with ferric chloride.They are much more stablethan the parent anthocyanins, for they are apparently not decolor-ised on keeping in solution. On heating, however, they lose theircolour, and this seems to be due to the conversion of the quinonoidpyrone structure of the anthocyanidin into an ordinary pyroneform in which t’he bridge oxygen has lost its strongly basic proper-ties to a great extent.Turning now to the question of the constitution of these sub-stances, a certain amount of information has already been gained.An =xamination of their empirical formulce suggests a kinship withthe flavone dyes, for the anthocyanidins are isomeric with severalsubstances of the flavone series.Thus cyanidin is isomeric withluteolin and fisetin, pelargonidin is an isomeride of apigenin,whilst delphinidin, quercitdn, and morin all have the same molecularcomposition.Further relations between the anthocyanidins themselves comet o light when we examine the decomposition products which arisefrom them on heating with alkali.Anthocyanidin Deconi posi tion Prodnc ts.l’elargonidiu, C,,HloO, Phlorogluciriol and p - Hydroxybenzoic acid.Cyanidin, C,,Hlo06 2 ) ,, Protocstechuic acid.Delphinidin, ClsH,oO, , I ,, Gallic acid.These reactions help t o clear up the question of the position ofthe oxygen atoms in the various anthocyanidin molecules.I n thecase of pelargonidin, for example, there are five oxygen atoms t oaccount for; three of these are in the phloroglucinol portion, oneis in the hydroxyl group of the phydroxybenzoic acid, a fourthmust go t o form the pyrone bridge, so that there is only a singleoxygen atom left unaccounted for out of the five. Similar reason-ing holds for the other substances.Now when i t is recalled that the anthocyanins are apparentlypyrylium derivatives there are two possible ways of regarding them;they may be considered as substitution products of either 2-phenyl-pyrylium or of 4-phenylpyrylium 138 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.c1 c:\/On further examination of cyanidin chloride, more light wasEvidently this substance, on the above thrown on the problem.assumption, might be either (I) o r (11) :c1 CI0 OH 0I ICareful treatment with alkali revealed results which decided thechoice.25 Were (11) the correct formula, i t should be possible t oisolate as an intermediate product a substituted benzophenone[maclurin, C6H3(OH),*CO*C6H,(OH)3], but no such substancecould be found.Further, formula (I) suggests the possibility thatby the oxidat’ion of the anthocyanin a dyestuff of the flavone seriesmight be produced or, conversely, the reduction of a flavone deriv-ative might yield an anthocyanin.The latter process seemed morepromising, and quercetin was chosen as a test substance. Whenreduced in alcoholic solution by means of magnesium and hydro-chloric acid in the presence of mercury a t Oo, quercetin was foundtQ yield a substance, allocyanidin chloride, which readily loseshydrogen chloride, and is converted into allocyanidin. Thisresembles closely, but is not identical with, cyanidin. When thereaction is carried out a t 3 5 O , however, the end-product is foundto be a mixture of allocyanidin and cyanidin itself, the lattersynthetic substance being identical with the natural productderived from roses or cornflowers.2b R. WillstPtter aud H. Mallison, Sitzusbgsber.K. Aknd. Wiss. Eerlin, 1914, 769 ;A., i, 1081ORGANIC CHEMISTRY. 139According to the views of Willstatter and Mallison, the reduc-tion of quercetin to allocyanidin takes the following course :HThe production of cyanidin itself from quercetin is of the greatestinterest from more than one point of view. I n the first place,since yuercetin itself can be synthesised, the reduction methodbridges the gap between the synthetic product and the naturallyoccurring colouring matter, and a synthesis of the latter has thusbeen accomplished. Again, this reaction clears up the question ofthe constitution of the colouring matter, and thus allows us todecide upon probable structural formulze for the kindred antho-cyanidins. It also helps us to trace the relation between the flavoneseries and the anthocyanins.The anthocyanins in their acid-freeforms are isomeric. with flavone derivatives which have one atomless of oxygen attached to their benzene nuclei. The flavones andflavonols contain the pyrylium nucleus in an oxidised condition.Thus the relation between members of the two groups is not closestin isomeric compounds, but, instead, we must compare similarlysubstituted compounds in pairs where the anthocyanin contains anextra atom of oxygen. For example, cyanidin is isomeric withfisetin, but i t is closely related t o quercetin, as we have seen.The following structures have been proposed as the: best repre-sentations of the various chlorides :OH ? 0Cyariidiii chloride.Pela rgo ti idi n chloride140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.OHQ10HO CHDelphinidin chloride.OH 0 OH 9‘ F’I I IlC.OH\.. / I i i/C.O~~e\-/ \A/0& O A A /-\OH Hc)/\A--/-\OMe\A/ OHHO CH HO11 y rtillidiii chloride, Oenidin chloride.OH F’ 0Malvidiii chloride.Various yellow and white flowers have been examined, and fromthem colouring materials of the anthocyanin group have beenobtained by reduction methods.26 Apparently the reaction givesrise to no anthocyanidin, and if care be taken not to carry thereduction process too far, it is not necessary to reoxidise the product in order to obtain the pigment. This investigation has thrownlight upon certain botanical speculations with regard to the pro-duction of the anthocyanins from yellow colouring materials.Willstatter and Mieg’s method of extraction has been applied t oobtain the fusariurn pigment.27 From Fusarium orobanchus twodifferent colouring matters were produced. One of these is a yellowanthocyanin pigment, which is soluble in water or in alcohol a t90°, whilst the other is a red carrotene which resembles that ofWillstatter and Mieg in many respects, but differs from it inbeing more readily soluble in chloroform than in carbondisulphide.The carrotene from fusarium gives the usual d o u rreactions with acid and alkalis, contains no nitrogen, and crystal-lises in plates. Solventshave different effects on the colour of the carrotene, according totheir nature and the experimental conditions. For example, in26 A.E. Everest, Proc. Rmj. s’oc., 1914, [B], 87, 444; A . , i, 978,27 Bezssonoff, Compt. rend., 1914, 159, 448 ; A , , i, 1135.It has not yet been completely analysedORGANIC CHEMISTRY. 141cymene the substance forms a reddish-violet solution, but on raisingthe temperature to the boiling point the colour changes to clearyellow, and as the solution cools again the red tint slowly reappears.Alteration in tint on exposure to air is found in the case of benzeneo r chloroform solutions of the pigment., where an originally reddish-violet liquid becomes blue.The absorption spectra of the three varieties of the carrotene,violet (in boiling alcohol), reddish-violet (in benzene), and yellow(in cymene after boiling), have been examined, and appear to con-tain three absorption bands, which are shifted in position in pass-ing from the violet to the red compound.The yellow pigment which occurs along with the carrotenebehaves like a weak acid, and easily unites with bases.It appearsto be accompanied by sugar, but it has not yet been proved that itis a glucoside.The roots of Datisca cannabina contain varying quantities of twocolouring matters; one of these is methoxylated, whilst the secondcontains no methoxyl group, and has the composition Cl,Hlo06.By benzoylation and acetylation28 i t was shown that four of theoxygen atoms belong to hydroxyl groups, and from the generalbehaviour of the substance i t is deduced that it belongs t o theflavone class., being isomeric with fisetin and luteolin.When hydrolysed with alkali, datiscetin (as the pigment is called)yields salicylic acid, whereas when bromine is employed as acleavage agent both bromosalicylic acid and tribromophloroglucinolhave been identified among the products.These data suggest thatdatiscetiri is probably 1 : 3 : 1’-trihydroxyflavonol,0 OHso that i t is very closely allied to morin.The colouring matter of the blackberry (Rubus discolor) hasbeen examined, and several lakes have been prepared from the dye,but so far very little information with regard t o its constitutionhas been 0btained.~9Crocetin,30 the pigment of saffron, has been found to have thecomposition ClOHl,O2. Various salts of the compound have beenprepared and analysed, but in this case, also, our knowledge of thecomposition of the substance is in an elementary stage.28 J.Leskiewicz and L. Marchlewski, Ber., 1914, 47, 1599 ; A . , i, 856.29 G. Vecchi, Staz. sperim. agrar. ital., 1914, 47, 60 ; A . , i, 978.3O F. Decker, Arch. Phrm., 1914, 252, 139 ; A , , i, 979142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The dye lokao, or China green,31 obtained from Rhamuus chboro-plmra, appears to be much more complex than the' other pigmentswhich have recently attracted atbention. The ammonium salt(ammonium lokaonate) has the composition C4,,H4,0,,-NH4, and,when treated with oxalic acid, liberates lokaonic acid, C42H46025,a bluish-black substance with a metallic lustre. When tseated withacids, the ammonium salt decomposes into rhamnose and lokanicacid, C,,H,O,,.The last substance is evidently a phloroglucinolderivative. The following scheme shows some of the decompositionsof lokaonic acid and its derivatives:Lokaonic acidILokanic acid + rhamnoseC42H46025J. H2S0436'31 C6H1305HNO, I KOHJ.Delokanic acid + phloroglucinol +, NitrophloroglucinolC H 3*O*CllH504 C6H603 4 HNO,Oxalic acid + C,H,O,N =2-nitro-5-methoxybenzoic acid ?ChZorophyll.I n the course of last year, the study of the constitution of chloro-phyll advanced rapidly, and the main lines of its structure appearto have been determined with some accuracy. The present yearhas not seen any great advance in this direction, and most of thework which has been carried out deals with the properties ratherthan with the constitution of the substance.It will be recalled that Willstatter's results pointed t o the con-stancy of the chlorophyll quotient in plants; this view hasbeen contested by Borowska and Marchlewski,32 who state that thequotient varies, not only from species to species, but even in plantsof the same species which are subjected to different external con-ditions.Thus if the absorption spectrum of the pigment is ex-amined, i t is found t o vary in different plants belonging to thesame species, and it is affected even by the stage of growth towhich the plant has attained. According to these authors, theabsolute and relative amounts of the bluish-green neochlorophyllproduced in given cases depend on the character of the soil ina2 H.Borowska and L. Marchlewski, Biochem. ZeiLwh., 1913, 57, 423 ; A., i, 73.A. Riidiger, Arch. Phnrrn., 1914, 252, 165 ; A . , i, 979ORGANIC CHEMISTRY. 143which the plant is grown; then, in turn, the quantity of pigmentprment regulates the power of the plant t o absorb light of a suit-able wave-length, and this, finally, controls the synthetic processesby means of which the plant tissues are formed.Another paper of interest on this question has been publishedby Stoklasa, 6ebor and Senft.g3 According to them, phosphorusenters largely into the processes whereby chlorophyll is produced.They regard chlorophyll as being separable into three differenttypes of compound:(1) Phzeophorbin and its metallic derivatives.(2) Phaeophytin and the phaeophytides.(3) Chlorolecithins of phzeophorbinphosphatides.The third class are compounds of phzeophorbin or of phzeophorbinwith phosphorglycerol.The phosphoric acid is united to theglycerol esters of unsaturatad acids or hydroxy-acids. The formeracids are produced in the plants during the spring and summer,and are converted into the corresponding hydroxy-acids by oxida-tion. The change of colour of leaves in autumn depends upon thehydrolytic fission of chlorophyll and the formation of phzeophytinand phosphatides, which have a brownish colour, and do not maskthe yellow and red tints of the carotins and xanthophyll. Mag-nesium, calcium, and potassium are the main metallic componentsof the chlorophyll group, and thO first of these is supposed to bean active co-worker with the phosphorus in the growth and meta-bolism of plants.The decomposition of chlorophyll in the light and in the darkhas been the subject of extensive investigations.34 When the pig-ment is exposed to light, aldehydes are liberated, and a t the sametime a reagent makes its appearance which is capable of decom-posing potassium io'dide.As is to be expected, the action of lightof different wave-lengths is not t'he same, the red rays having moreinfluence than those of the blue end of the spectrum. Rays of allwave-lengths are active, however, for with a much longer exposureto blue light the same results are obtained as are observed with ashort exposure to red rays. The results are similar whether thechlorophyll is bleached in the plant fibre or is extracted and thenbleached.The presence of oxygen is necessary in these photo-decomposi-tions, and the action of the oxygen is evidently not catalytic, as itdisappears during the reaction.Hydrogen peroxide attacks chlorophyll both in the light and inthe dark.When light is excluded, the reaction is slower than33 J. Stoklasa, J. sebor, and E. Senft, Bot. Zentr., 30, i, 167; A , , i, 423.s4 H. Wager, Proc. Roy. S'oc., 1914, [B], 87, 386; A., i, 561144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.when the specimen is illuminated. I n daylight the reaction doesnot appear t o be much more rapid than the decomposition of chloro-phyll in presence of oxygen under the influence of light.The results of these investigations suggest that the productionof sugars and starch in the green leaf may not be due t o the directphotosynthesis from carbon dioxide in water, but may be broughtabout by the photeoxidation of chlorophyll, with the productionof aldehyde and a subsequent polymerisation of the aldehyde intosugar.With regard to the actual mechanism of the photo-oxidationprocess, it seems probable that hydrogen peroxide plays a part inthe reaction.Formaldehyde se’ems to be a main product in thedegradation of chlorophyll.35 The resulh obtained in these twoseries of researches should be carefully collated.The pigments of brown a l p have been submitted to investiga-tion, and a long-debated question appears to have been settled.36Chlorophyll as such has been shown to exist in these plants; and,in addition, there are three yellow, non-nitrogenous pigments :fucoxanthin, carotin, and xanthophyll.The molecular proportiouof chlorophyll to the yellow pigments is higher in the land plantsthan in the a l g aPhyllocyanin and phylloxanthin have been submitted t o furtherinvestigation.37 The former substance was obtained by the actionof hydrochloric acid on chlorophyllan, and subsequent purificationof the product. On treatment with 1 per cent. aqueous potassiumhydroxide, phyllocyanin yields a mixture of anhydrophyllotaoninand some other substance. This paper also contains a criticism ofWillstatter’s researches on the action of alkalis on chlorophyll.Pyrrole Deriua tives.The interaction between the Grignard reagent and compounds ofthe pyrrole group appears still obscure.Two possible views of themechanism of the reaction have been put forward, one of whichpresupposes a direct action of the Grignard reagent on a carbonatom of the pyrrole nucleus, whilst the other hypothesis dependsupon the assumption that the reaction occurs in two stages, first,an attack upon the imino-group of the pyrrole ring, and then sub-sequent wandering of the *MgX group t o a point in the nucleus.An attempt has been made to settle the question by utilisingN-methylpyrrole as one of the reagents.38 Here there is noC. H. Warner, Proc. Roy. Soc., 1914, [B], 87, 378; A., i, 563.:M R. Willstatter and H. J. Page, Anualen, 1914, 4044, 237 ; A., i, 708.37 H.Malarski and L. Marchlewski, Biochem. Zeitsch., 1913, 57, 112 ; A . , i, 72.38 I<, Hess and F. Wissing, Ber., 1914, 4’7, 1416; A., i, 725ORGANIC CHEMISTRY. 145hydrogen atom attached to the nitrogen of the imino-group, so thatthe “two-stage” process may be left out of consideration. Theresults in this case are said to be similar to those obtained whenpyrroles containing the *NH* group are used. The work has beencriticised, however,39 on the ground that thP N-methylpyrrole usedwas not sufficiently pure, but contained an admixture of unsubsti-tuted pyrrole. It is to be hoped that the matter will be clearedup shortly, as the point is one of some interest.The alkylation of pyrroles has been closely studied recently, andthe matter is of importance on account of the relation between thepyrrole group and the colouring matter of the blood.When theGrignard reagent is allowed t o act on a secondary pyrrole, the firststage in the reaction appears to be the formation of an N-mag-nesium derivative, aad when this is treated with alkyl iodides theproduct is an alkylpyrrole. Thus, from methyl iodide and mag-nesium pyrryl bromide it is possible to obtain a mixture of alkyl-substituted pyrroles, of which the most plentiful is 3-methylpyrrole.The reaction appears to be a generalThe older method of alkylation, by the action of an alkyl iodideon sodium pyrrocarboxylate, has been further investigated in thecurrent year,41 as well as the direct action of alkyl iodides onp y r r o le s .42When chloroform is allowed to react with alkyl-substitutedpyrroles, the initial step in the process appears to be the elimina-tion of a molecule of hydrogen chloride with the formation of adichloromethylpyrrolenine.This reaction has been studied in thecase of 2 : 3 : 4 : 5-tetrachloropyrrole als0,43 and as it has beenfound to work with several other pyrrole derivatives, i t seems t obe a general one.Another general method applicable in the pyrrole series is theaction of sodamide on the dialkylallylacetophenones, the end-pro-ducts being pyrrole derivatives. Thus, when dimethylallylaceto-phenone is mixed with its own bulk of benzene and treated withone-fourth of the theoretical amount of sodamide, the chief pro-duct appears to be 2 : 4 : 4-trimethyl-5-pyrrolidone.44A third method leading to the synthesis of alkylated pyrroles,namely, the distillation of pyrrolecarboxylic acids, has been thesubject of extensive investigation,45 and numerous methyl deriv-atives of pyrrole have been produced in this manner.39 B.Oddo, Gaxxetta, 1914, 441, i, 706; A., i, 1142.40 B. Odd0 and R. Mameli, ibid., 1913, 43, ji, 504 ; A., i, 80.41 Ibid., 1914, 44, ii, 162; A., i, 1142.-la G. Plancher and 0. Ravenna, Atti R. Accad. Lincei, 1913, [v], 22, ii, 703 ;A., i, 319.44 A. Haller and E. Bauer, Compt. rend., 1914, 158, 1086 ; A., i, 724.4j H. Fischer and H. Rose, Zeitsch, physiol. Chem., 1914, 91, 184 ; A., i, 862.REP.-VOL. XI. L43 G. Plancher and T. Zambonini, ibicl., 712 ; A., i, 321146 ANNUAL REPORTS ON THE PROaRESS OF CHEMISTRY.It is well known that the direct action of halogens on pyrrolederivatives is so violent as to make it impossible t o prepare mono-halogen-substituted pyrroles in this manner.A simple method 46has now been devised by means of which these compounds caneasily be obtained. When magnesium methyl iodide is allowed toact on a secondary pyrrole, the hydrogen atom of the imino-groupis displaced by the radicle 0Mg-X (where X is a halogen atom).If this compound is treated with halogens a t low temperatures, areaction takes place in accordance wit'h the scheme:The monohalogen derivatives of pyrrole prepared according tothis method are unstable substances, and decompose even on keep-ing. Thus, bromopyrrole explodes violently when left in a sealedglass tube, the reaction apparently being represente,d by theequationDuring the last twelve months, the study of the indole grouphas not been pursued with the same vigour as was shown in theprevious year.The only point of interest that has arisen is thepreparation of 2 : 2I-di-indyl47 by heating together oxalo-o-toluidideand sodium amyloxide a t 360O.Further investigation of the picolide and pyrindole groups havebeen carried out, and an attempt has been made' t o determine theinfluence of substitution on the ease with which the compoundscan be prepared.48 Thus, when B-picoline, y-picoline, or pyridineitself is heated a t 200° with acetic anhydride, no picolide is pro-duced, alt,hough members of the picolide group are easily pro-duced from 2 : 4-dimethylpyridine and 6-phenyl-2-methylpyridineunder the same conditions.Pyridine as a Solvent and Catalyst.The use of pyridine as a solvent for inorganic and organicmaterials is not new, but some recent work49 suggests that itsapplication in this capacity requires circumspection before i t cansafely be regarded as a neutral solvent.When employed in the46 K. Hess and F. Wissing, Ber., 1914, 47, 1416 ; A., i, 725.47 U'. Madelung, D.R. -P. 262327 ; A., i, 89.48 M. Scholtz, Arch. Pharm., 1913, 251, 666 ; A., i, 431.49 M. Raffo and G. Rossi, Gnzxetta, 1914, 44, i, 104; A . , i, 572ORGANIC CHEMISTRY. 147case of sulphur compounds, i t appears to be attended with acerbain risk, as the following results show.Sulphur itself dissolves in pyridine on heating, but hydrogensulphide is liberated, pointing to a decomposition of the solvent.M7hen the solution is allowed to cool, a pitchy material is deposited,which has not yet been fully investigated.When organic sulphur derivatives are dissolved in pyridine, asimilar evolution of hydrogen sulphide takes place, but in thiscase the hydrogen is not furnished by the pyridine, but is derivedfrom the solute.The pyridine appears to act merely as a catalystfavouring the decomposition of the dissolved substance. Thus,thioacetamide dissolved in pyridine liberates hydrogen sulphide,and becomes converted into acetonitrile; thiobenzamide behavessimilarly, and produces benzonitrile.I n the case of diphenylthiocarbamide, the decomposition takesplace in two stages.The first phase of the reaction ends in theproduction of carbodiphenylimide,CS(NHPh), =H,S + C(:NPh),.As soon as this reaction has run t o its conclusion, a second reactionoccurs between the carbodiphenylimide and hydrogen sulphide,thus :SC(:NPh), + 3H2S = CS(NHPh), + NH,Ph +PhN:C(NHPh),+ C h .I n the presence of pyridine this reaction proceeds a t about 1 1 6 O(b. p. of pyridine), whereas in the absence of pyridine a tempera-ture 50° higher is necessary in order to bring i t about.Other analogous reactions have been examined, and i t appearsevident that in the case of sulphur compounds i t is necessary tobe extremely careful in using pyridine as a solvent on account ofthese peculiar effects which i t produces.D i ILapll t ha t h io xo P L ~ i~ ~n Su 7 I S .Reference may be m a ~ l s 5 ~ t o the fact that there appear to betwo series of salts ralated to dinaphthathioxin, and it seems notunlikely that they are somewhat akin to the twin series producedfrom compounds capable of assuming either the phenopyrylium orthe ordinary pyrone structare.The thioxonium salts are obtainedby the action of an acetyl haloid on naphthasulphonium-quinoneor by acting on the corresponding sulphoxide with perchloric orsulphuric acid in hot acetic acid solution. I n either of thesemanners, salts of the following type are formed:50 B. Ghosh and S. Smiles, T., 1914, 105, 1739.L 148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.where X represents either a halogen atom or a univalent acidradicle.The true sulphoxide salts are colourless, whereas thethioxonium salts are highly coloured. The perchlorate has beenobtained by the use of cold reagents, and, on heating, i t is con-verted into the purple thioxonium perchlorate.The AIkaloids.The researches in this department of chemistry during the pre-sent year do not appear t o have thrown much light on the mainproblems of alkaloid constitution ; steady progress has been madein many directions, but there has been no example of the culmina-tion of an investigat'ion in the case of any of the more importantalkaloids. Instead, the researches of the year have been devotedt o that clearing up of minor problems which is the necessary pre-liminary to bro,ader outlooks.A careful comparison has been made between the properties ofquebrachine and those of that interesting alkaloid, yohimbine,51and the results seem to establish beyond doubt that the two sub-stances are identical.A discussion of the present state of our knowledge ofcantharidin52 leads to the conclusion that the formula of thissubstance is the following :CH*CO\ \CH2 CH I /\C H,/\-cH~co/0Cant haridin.Cantharidin behaves like an anhydride, being graduallyneutralised by alkali. When heated with an acetic acid solutionof hydrogen bromide, cantharidin gives rise to three products :(1) a dibromo-derivative, to which the structure I is ascribed;(2) a compound, C,,H,,0,Br2 ; and (3) bromohydrocantharic acid,which appears t o have the constitution represented by 11.Thelast substance can be resolved into its optically antipodic forms,and when the active forms are reconverted into cantharidin, thesynthetic cantharidin is found to be optically inactive, in51 E. Fourneau and H. J. Page, Bull. SOC. Phnrmacol., 1914, 21, 7 ; A.,52 J. Gadamer, Yerh. Ges. deut. Nnturforsch. Aertzte, 1913 (1914), 2, 494 ;i, 862.A . , i, 707ORGANIC CHEMISTRY. 149agreement with the symmetrical structure suggested in the formulaabove :\ CH( C0,H) \ PH"/ 7% FH/CH2\/CHBr*Co\CH,/\CHB~GO / \CH,/\CHR~--CO />o CH, CH >o YH2 FHCH, CH(1.) (II.1When heated with acetyl chloride, active cantharic acid yields afeebly active substance, isocantharidin, which is assumed to havethe following constitution :\ CH(OH)*CO PH"\/YH2 !?\c €3,,'\ c i3 ,-- co/'0 / ' CH, CReference may also be made to the preparation of some salinedouble compounds from cantharid~lethylenediamine.5~Met'anicotine 54 has been the subject of some investigationsduring the current year, but as the results do not lend themselvesto summarisation, the reader is referred t o the original paper.It has been shown that hydrastinine hydriodide55 can be p r epared by a very simple reaction from dihydrohydrastinine.Alcoholic solutions of iodine and dihydrohydrastinine are mixedin the presence of potassium acetate, and the required compoundis obtained from the solution in the usual manner.Various saltsof hydrastinine and its homologues 56 have been synthesised, whichhave structures represented by the following formula, in whichR = hydrogen, alkyl, aryl, or alkylaryl ; X = acidic group :CH,In order t o prepare them, N-acylalkyl derivatives of homo-piperony lamine,CH,:0,:C6H,* CH,-CH,*N<Aryl Acylare condense,d with phosphoric oxide, and the dihydroisoquinolinederivatives thus obtained are converted into the required salts.xi Farbwerlre vorm.Meister, Lucius & Briining, D.R.-P. 269661 ; A., i, 708.54 E. Maass and K. Zablinski, Ber., 1914, 47, 1164; A., i, 723.Farbenfabriken vorm. Friedr. Bayer & Co., D. R. -P. 267272 ; A., i, 79.58 H. Decker, D.R.-P. 267699; A., i, 198150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A synthesis of racemic hygrine has been carried out in thefollowing manner.57 Two isomeric 1-methylpyrrolidylpropanolswere prepared, one of which, on oxidation, should yield racemichygrine.It was found that the use of formaldehyde as a methyl-ating agent resulted in a simultaneous oxidation of the hydroxylgroup, and the products were obtained almost quantitatively.Comparison of the synthetic substances with the natural hygrineleads to the conclusion that the latter has the constitution repre-sented byThe oxidation of hydroxy-amines to amineketones, according t othe following scheme,:C*NHR . . . CH(0H) . . . +CH20=:C*NMeR . . . CO . . . + H20,appears t o be of general application.A considerable amount of work has been done in the tropinegroup, solanines 58 having been very carefully examined.Thehydrolysis of this compound produces solanidine-s, dextrose,d-galactose, and d-aldomethylpentose. There is t’hus only one atomof oxygen in the solanidine molecule, and it apparently belongsto a hydroxyl group. The nitrogen atom is present as part of animino-group in both solanine-s and solanidine-s.The action of nitrous acid on amines has been studied in thisseries of compounds, and the results obtained appear to justifythe following conclusions. The primary result of the action ofnitrous acid on a primary or secondary amine is the formation ofthe nitrite, NHRR’,HNO,. This compound then undergoes re-arrangement into an as-diliydroxyhydrazine derivative,NRR’*N(OH)2.The decomposition of this last substance may follow three liiies :(1) Anazoic decomposition.-Here nitrogen is evolved, and therelsults are as follows: ammonium nitrite yields water; primaryamines produce water and an alcohol; secondary amines of thetype NR, decompose, with the formation of a single alcohol, whilstsecondary unsymmetrical amines, NRR’, give two differentalcohols.(2) Dia.zoic decomposition.-Here ammonium nitriteyields nitrosoamine, NH,*NO, or isonitrosoimide, NH:NOH ;primary amines give either nitrosoamines, NHR-NO, or diazo-hydroxides, NR:N*OH, whilst secondary amines form truenitrosoccompounds, NRR’oNO. (3) Cyclazoic decomposition.-In57 K. Hess, Ber., 1913, 46, 4104 ; A., i, 199.58 G. Odd0 and M. Cesaris, Gazzetta, 1914, 44, ii, 181, 191, 209; A . , i, 1173,1174; F.Tutin and H. W. B. Clewer, T., 1014, 105, 559ORGANIC CHEMISTRY. 151this case, either stable azocyclic compounds or $-nitroso-compounds,such as I from aminocamphor nitrite(, or allonitroso-compounds likeI1 from +nitroso-oxindole, are obtained :(1.1 (11. )The following formula for morphine has been proposed byBraun,Sg but the evidence upon which it is based is of so lengthya nature that it cannot be summarised here, but must be soughtin the original paper:H2-H/ /\ / MeN >IX-H, \ I / ~~-\-/ \\ OH '\ / \/0I n the group of strychnine alkaloids, progress is being made inour knowledge of decomposition products, but during the presentyear there is no marked advance along general lines. Strychnine,GObrucine,61 acetylbrucinolone,62 and acetylstrychninolone 63 have allbeen oxidised by different methods, and the results are likely t oaid us later in settling the question of the structure of the variouscompounds, but i t is impossible to give a condensed account of thework in this place.The addition of bromine t o cinchotoxine has been investigated,but the results are of sixch a detailed character that no purposewould be served in giving a reproduction of them in this place.Here, also, the reader must be referred to the original.64A very complete study of the absorpt'ion spectra of variousalkaloids belonging t o the zsoquinoline group has been made,66 andi t has been shown that the presence of unreduced catechol nucleiin their molecules introduces a common factor into all the absorp-tion curves.Emetine and cephaeline also show a similar pecu-liarity, so that i t appears probable that their nuclei contain theJ. von Kraun, Ber., 1914, 47, 2312 ; A., i, 1138.H. Leuchs and H. Ranch, ibid., 3917 ; A., i, 199.6o H. Leuchs and G. Schwaebel, ibid., 1913, 46, 3693 ; A . , i, 79.62 Ibid., 1914, 47, 370 ; A . , i, 31i.63 H. Leuchs, ibid., 536 ; A., i, 429.64 G. Rohde and S. Meissner, ibid., 1507 ; A . , i, 71965 J. J. Dobbie and J. J. Fox, T., 1914, 105, 1639152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.catechol group, a conclusion which is supported by chemicalevidence.The constitution of harmine and harmaline still remains in doubt.From the fact that harminic acid yields isonicotinic acid on oxida-tion, i t is concluded66 that the nitrogen of the pyrrole nucleuscannot be ortho- to the pyridine ring, as a nitropyridinecarboxylicacid might' have been expected in that case.Assuming this postu-late, which appears to be open to criticism, the following formulafor harmine has been suggested by 0. Fischer :The full evidence in favour of i t must, however, be looked for inthe original paper.The action of light on mixtures of various alkaloids and ketones67has led to some results of interest. When benzophenone is employedalong with coniine, sparteine, or piperine, benzopinacone is pro-duced, which is probably formed by the abstraction of hydrogenfrom the alkaloids. Nicotine condenses with benzophenone, andstrychnine appears t o be polymerised in the presence of the ketone.Narceine and bemophenone produce a reddish-brown, crystallinesubstance.Acetophenone with sparteine forins acetophenonepina-cone and a gelatinous base.The Purine Grozcp.The most important work in this branch of the subject is to befound in some papers by E. Fischer and his colleagues,68 which ap-parently mark the opening of another chapter in the history of thesynthesis of naturally occurring subst,ances. The objective of theinvestigations is the synthetic preparation of the nucleotides, butthe first' steps which have already been taken are concerned withthe preparation of glucosides of the purine derivatives. It is hopedthat the combination of these glucosides with phosphoric acid willsoon be carried out successfully, for this would add the nucleotidesto the other three classes, sugars, purines, and polypeptides, forour main knowledge of which we are indebted t o Fischer's labora-tory.Several of the purine glucosides have now been preparedtiti 0. Fischer, Ber., 1914, 47, 99 ; A., i, 316; compare Ann. Report, 1912, 159.67 E. Paternb, Gnxuctln, 1914, 44, ii, 99 ; A . , i, 1137.E. Fjscher and U. Helfeiich, Rcr., 1914, 47, 210 ; A . , i, 333 ; E. Fischer andI<. von Fodor, ibid., 1058 ; A , , i, 741ORGANIC CHEMISTRY. 153by the action of acetobromoglucose or its congeners on salts of thepurines with silver or other heavy metals. Considerable difficultyhas been found in purifying the products, as great care is necessaryt o prevent hydrolysis taking place.Glucosides of adenine, xan-thine, hypoxanthine, guanine, theophylline, and theobromine havebeen prepared, and in one or two cases galactosides and rhamno-sides have also been obtained.Various other papers dealing with the purine group have beenpublished, although they do not lend themselves to detaileddescription. Thus a series of studies in the degradation of theo-phylline and its allied compounds has appeared,69 some uramilderivatives have been examined,70 and Bhe salt-formation of barbi-turic acid and its analogues has been investigated.71The Colo.rcring Matter of the Blood.Last year an account was given of Willstiitter's views on theconstitution of haemin,72 and it appears desirable t o summarise herethe criticisms which Kiister 73 has passed upon them.Willstatter and Fischer regard the elimination of iron froinhEmin as a process which occurs in two stages, the first step beingthe addition of a halogen hydride to the hzemin molecule, and thenext process being the actual removal of iron to produce haemato-porphyrin.Kuster, in his latest publication, objects t o this sug-gestion, and thinks that t b matter is better expressed if theaddition of halogen hydride and the elimination of the iron atomare regarded as two loosely connected processes which are broughtabout through the agency of the same reagent.On Willstatter and Fischer's theory, the metallic atom in theliaemin molecule is united by means of two principal valencies t otwo pyrrole nitrogen atoms and by t'wo auxiliary valencies to twoother nitrogen atoms, each of which is a common member of apyrrole and a pyridine ring.The action of hydrobromic acidbreaks the latter (auxiliary) bonds, leaving the easily rupturedmain valencies intact. Kuster, on the other hand, brings forwardevidence that throws further light on the subject. H e finds thatwhen haematin is treated under pressure a t 130° with 10 per cent.hydrochloric acid, the iron is practically all removed from themolecule, whilst only traces of haematoporphyrin are produced ; b u twhen hzmin is similarly treated very little iron is displaced,69 H. Riltz and I<. Strufe, Aqtnalen, 1914, 404, 131, 137, 170 ; A . , i, 58G, 587,588.i" H. Biltz, {bid., 180, 199 ; A . , i, 589, 591.i1 lbid., 186 ; A ., i, 590.i3 W. Kiister, Zeilsch. physiol. Chwn., 1913, 88, 377 ; A . , i, 35.7z A m . Report, 1913, 157-8154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.although much haematoporphorin is formed. Now it is knownt h a t the chlorine in hzemin cannot wholly be removed by the actionof alkali, which may be taken its a proof that the non-removablechlorine’ is attached to a quaternary nibrogen atom, and that thechlorine in hzemin is not united simply with iron or with nitrogen,but must be regarded as standing in some relation t o the twoelements jointly. This assumed division of the valency of thechlorine at’om is regarded by Kiister as the cause of the iron atombeing able t o unite with the basic nitrogen atoms so firmly as toforbid its removal except by the use of energetic reagents.Kuster urges in support of his view that if Willstiitter werecorrect and the chlorine atom played no great part in the matter,then it should be equally easy t o remove the iron atom fromchlorine-free derivatives of hzemin as i t is to eliminate the ironfrom hzemiii itself.This appears, however, to be contrary t o theexperimental evidence.Similar views are put forward with regard to the difference inreaction between hzemin and its methyl ester with respect t ohydrochloric acid ; the dimethyl ester, when thus treated, losesmuch more iron than does hxmin itself. Kuster regards this asa result of the relations subsisting between the carboxyl radiclesand the basic nitrogen atoms; the carboxyl and the ferrichloro-groups are supposed mutually t o saturate each other’s basicproperties, and when the dimethyl ester is substituted for thefree carboxyl compound, this activity is increased, so that in thedimethyl ester the bond between the chlorine atom and the basicnitrogen atom is weakened to such an extent that the main holdon the iron atom is maintained by the chlorine atom.Whence itfollows that the iron in this case becomes more readily separatedfrom the rest of the molecule.Further evidence is found in the behaviour of mesohzmin, whichKiister declares t o be lacking in the structural conditions postu-lated by Willstatter for the stability of its iron atom, although inactual practice the stability of hEmin and mesohzemin do notappear t o be very different.Kuster finally objects t o Willstatter’s rather ex cathedra state-ment that the existence of a sixteen-membered ring is improbable,and points out that in actual practice such a ring has beenobtained by R ~ g g l i .~ ~The paper must, however, be consulted in the original, as it doesnot lend itself to summarisation.A general review of the work which has been done on theoxidation of hzemin has been published by Hahn,75 but it is hardlyI?. Ruggli, Annalen, 1913, 399, 174 ; A , , 1913, i, 1106.75 A. Hahn, Zeitsch. Biol., 1914, 64, 141 ; A., i, 993ORGANIC CHEMISTRY. 155up to date, for in one section of the subject-the constituentpyrroles of hzmopyrrole oil-the most recent paper mentioned isdated August, 1912.Direct attempts to prepare ferropyrroles76 have been begun, butthe results, so far, have been rather in the nature of clearing theground. A t first it was decided t o investigate the reaction betweenthe Grignard reagent and ferric chloride, but the reaction did notseem t o promise much when the reagent was prepared fromaliphatic derivatives.Thus, magnesium ethyl bromide and ferricchloride yield ethyl chloride, ferrous chloride, and magnesiumchlorobromide in accordance with the equationMgEtBr + Fe,Cl, = EtC1+ 2FeC1, + MgBrC1.Magnesium phenyl bromide and magnesium benzyl bromideappeared to hold out better hopes, for, although the final productsin these cases were respectively diphenyl and dibenzyl, this resultpoints to the intermediate formation of an organo-ferrichloride,which then undergoes decompositiolz into the1 hydrocarbon, iron,and ferrous chloride, thus:2FePh2C1 = CBH,Ph + FeC1, + Fe.Success was attained in the preparation of di-2-methylindolyl f erri-chloride,which was obtained by the action of ferric chloride on a Grignardreagent derived from 2-methylindole.When the crude hzemopyrrole of Nencki and Zaleski is treatedwith diazonium salts, a portion of i t produces a red azo-dye, andthis particular constituent of the hzemopyrrole mixture has beentermed hzemopyrrole I.It has since been shown that this sub-stance is probably 2-methyl-5-ethylpyrrole, and in the present yearthe matter has been put beyond dispute by the synthesis of thelatter compound,77 which appears t o produce the same azo-dye asis obtained from the naturally occurring substance.The synthetic product is obtained by dry distillation of methyl-ethylmaleinimide with calcium hydroxide and zinc dust in a currentof carbon dioxide.When the end-product of this reaction istreated with ptoluenediazonium chloride, a mixture of two dyesis obtained, the structures of which are represented by I and 11,which concords with the results obtained with the natural hzemo-pyrrole (I):76 B. Oddo, Gazzettn, 1914, 44, ii, 268 ; A . , i, 1176.77 J. Grabowski and L. Marchlewski, Ber., 1914, 47, 2159; A, i, 993156 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,SMefEt gMe*EEtN H NHC,H:,Me*N,*C! C-C C*N,*C6H,Me\/ \/(1. ) ;C;iVe RE tC,H,Me*N,-C C*N,*C,H,Me\/NH(11.)The presence of these substances in hzmopyrrole is adduced asevidence that some earlier views will require revision.The isolation of the constituents of hEmopyrrole oil has beeiicarried out by a process of fractional precipitation with picric acid,and in this way i t has been found possible to isolate hzmopyrrole,phyllopyrrole, cryptopyrrole, and the '' haemopyrrole-a " of Pilotyand Stock.'*A separation by means of picrates has also been used in the casesof the esters of phono- and isophono-pyrrolecarboxylic acids.79 I nthis way it has been shown that the isophonopyrrolecarboxylic acidobtained from hEmine is identical with that derived from bilirubin.It is well known that when hydroxylamine is allowed to reactwith pyrrole, the products are ammonia and the dioxime of succin-aldehyde :Although this reaction is less easy to carry out in the case of thealkyl derivatives of pyrrole, it seemed likely that some interestingresults might be obtained in this way in the case of those alkyl-pyrroles which are connected with the colouring matter of theblood.Attempts have therefore been made in this direction.Tetramethylpyrrole, when treated with hydroxylamine, is con-verted into a dioxime of the formula C8H,,02:and examination shows that the parent ketone is the same com-pound as that which is obtained80 when methyl ethyl ketone issubmitted to the action of sunlight.Bilirubin and hamin were also treated with hydroxylamine inthe hope of producing a fission in their rings, but no results wereobtained. On the other hand, porphyrinogen undergoes a re-78 H. Fischer and K. Eismayer, Ber., 1914, 47, 1820 : A . , i, 886.79 H. Fischer and H. Rose, ibid., 791 ; A . , i, 429.80 H. Fisclier and W. Zimmermann, Zcitsch. physiol. Chcm., 1914, 89, 163 ;A., i, 318ORGANIC CHEMISTRY. 157action totally different from that which was anticipated, for,instead of a rupture of the ring, an oxidation reaction occurs,which yields as end-products mesoporphyrin and ammonia.An attempt has been made t o prepare coloured derivatives ofdipyrrylmethane with a view to a comparison between them and theblood pigment.81 Substances like the following have been pro-duced by condensing hamopyrrole-b and other compounds withchloroform :The absorption spectra of the compounds are somewhat similar tothat of bilirubin, but do not resemble the spectrum of the colour-ing matter of the blood.Similar attempts have been made, using perchloroethane, t o pro-duce the twin carbon bridge in compounds of the following type:AB>\C--C<kwhere the radicle " A " is N<"R'8R, and the radicle " G-CRB " isI 1 CR:$JR PU'II<F-,CR . The absorption spectra of the compounds derivedfrom hamopyrrole-b and perchloroethane resemble those of certainchlorophyll derivatives, such as phytochlorin-e. Other att'eniptshave been made, using chloral and glyoxal to form bridges, andthese also have given rise to products of some interest. Form-aldehyde was not found suitable.The Synthesis of Haematic Acid.The preparation of hamatic acid has proved to be comparativelysimple.82 Ethyl a-acetylglutarate was mixed with ether andpotassium cyaqide, and the calculated quantity of hydrochloricacid was then very gradually added, the reagents being constantlyshaken for two days. After separation from by-products, the resi-due was hydrolysed with 25 per cent. hydrochloric acid, extracbedwith ether, and the residue, after evaporation, was dissolved inwater and shaken with chloroform to remove further by-products.I n this way, a mixture of a tricarboxylic acid and a lactone wasproduced, which, on heating a t 183O under 9 mm. pressure, wasconverted into haematic acid. The process is outlined in thefollowing scheme :0. Piloty, J. Stock, and E. Dormaim, Ber., 1914, 47, 1124; A . , i, 755.s2 W. Kusterand J. Weller, ibid., 532 ; A., i, 442158 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.COMe*CH(C0,H)*CH2*CH2*C02H -+CMe(OH)(CO2H)*CH(C'O,H)*CH2*CH2*CO,H +~Me:$!*CH,*CH,*CO,Hco co0\/The Bile Pigment.83As both this subject and its nomenclature are somewhat com-plicated, i t may be well to recall the relations between certaincompounds. Haematin, which is the non-albuminous component ofthe blood pigment, forms the source of bilirubin, a constituent ofbile. The decomposition of bilirubin produces various substances,among which is bilirubic acid,84 and this, in its turn, can be de-graded to cryptopyrrole and isophonopyrrolecarboxylic acid.Cryptopyrrole has the structure I, whilst for isophonopyrrolecarb-oxylic acid two alternative formulae (I1 and 111) have beenproposed :fMe*sEt flUe*~-CH,*CH,*CO,H EMe*;CI1*CH2*CH,*CO,HCH CMe CH CMe CMe CHOr \/N H\/NH\/NH(1.1 (11.). (111.)When oxidised by another method, bilirubic acid yields differentproducts, methylethylmaleinimide (IV) and hzmatic acid (V) :$!Me:$!Et yMe:y*CH2*CH2* CO,Hco co co co\/NH\/N HFinally, the action of nitrous acid(IV), haematic acid (V), and theacid (VI), instead of the oximecarboxylic acid :The same oxime is(V. 1pro'duces methylethylmaleinimideoxime of phonopyrrolecarboxylicof the isomeric isophonopyrrole-~Me:$l*CH,*CH,*CO,HCO CNOH\/NH(VI. 1obtained by the action of nitrous acid ontrimethylpyrrolepropionic acid, which seems t o show that thepropionylcarboxylic acid radicle exerts considerable influence onthe structure of the product.EG For an account of previous work reference may be made t o Ann. Report, 1912,170.84 H. Pischer and H. Rose, Zeikch. physiol. Chem., 1914, 89, 255 ; A., i, 309ORGANIC CHEMISTRY. 159Now, since bilirubic acid, when treated with nitrous acid, doesnot produce an oxime of its own, but yields, instead, the oxime ofphonopyrrolecarboxylic acid (VI), the deduction may be drawnthat the “pyrrole acid ’’ in the bilirubic acid molecule is a tetra-substituted one, which leads t o the conclusion that the bilirubicacid structure is built up from a trimethylated pyrrolepropionicacid united with the basic pyrrole radicls through substitution ofone of the methyl hydrogen atoms by the basic nucleus. I n otherwords, bilirubic acid might have the formula V I I :fi Me-SEt Me*g*C H,*C H,*CO,H0H.C C-CH,-C CMe\/NH\/NH(VII. )Against this might, be urged that sodium ethoxide is almostwithout action on bilirubic acid, whereas substances containing twopyrrole nuclei unite(d by a methylene group are usually easilydecomposed by this reagent. It has now been proved, however,that bilirubic acid (and even hzmin) can be decomposed by meansof potassium methoxide, so that this difficulty vanishes, and theproposed formula for bilirubic acid appears t o be placed on asound basis.The constitution of bilirubin itself now lies open t o attack.The action of sodium ethoxide on this substance produces a yellowxanthobilirubic acid, which appears to stand in close relationshipwith bilirubic acid, since it yields the latter substance on reduc-tion. Its constitution seems t o be expressed by$!Me:$!Et ;cI! Me* E*CH,* CH,*CO,HCO U==CH-C CMe\/NH\/NHFurther considerations drawn from the behaviour of bilirubin andhemibilirubin, into which we cannot enter here, lead Fischer andRose to the following structural formula for bilirubin :CH,: C H *$--fi Me ; C i ’ M e * p 3 : CH,c c C C*OH\/\ /\/N H \ / N HNH / \ N HC = C/\/ \/\ C E 8 gM0 CMe*C*C H,* CH,*CO,H CO,H*CH,*CH,-C--CM160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,and in consequence they consider that Willstatter’s suggestedformula for haemin is not above discussion.A comparison between the foregoing Report and those of previousyears which covered the same field will show that on the presentoccasion a greater number of subjects has been dealt with thanwas the case in 1912 or 1913. This has its advantages in givingan appearance of variety to the Report, but it has the correspond-ing drawback of leaving in the mind of the reporter a feeling thatperhaps he has not devoted sufficient space to certain importantfields. It is safe to say, however, that no Report is ever likelyto satisfy its author; his chief comfort is based on the hope thathis readers may not be so critical of shortcomings as he himselfis bound to be. Many subjects have been perforce omitted fromthe present Report simply because a proper description of themwould have entailed too much dwelling upon detail; other subjectshave been left out because any full discussion of them would havenecessitated somewhat lengthy historical introductions, for whichspace could not be spared, It must not, therefore, be supposedthat t,he foregoing sections include all the important work of theyear: rather should they be regarded as examples of the kind ofinvestigations which are being carried out in the various fieldsunder review.A. W. STEWART

ISSN:0365-6217    

DOI:10.1039/AR9141100063

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THE general plan of this Report is identical with that followed inthe corresponding Reports of the last three years. The arrange-ment of the matter falling under the head of organic analysispresents some difficulty, as may be seen by the paragraphs relatingto the estimation of sucrose and other carbohydrates beingseparated by matter cognate to neither. As far as possible,organic methods of general interest are dealt with first, and arefollowed by short paragraphs dealing with the analysis of foods,drugs, fats, fermentation products, and other materials of specialtechnical interest, but the number of papers referred t o undereach of these heads is too small to justify cross-headings. Wateranalysis, not referred t o last year, is given a good deal of space,but the separate section on physiological methods is omitted thisyear, such physiological methods as have been selected for noticefinding a natural place elsewhere in the volume.General.The solubility, and especially the curve expressing change ofsolubility with change of temperature, are valuable criteria indeciding the identity of a substance, and also in some cases indeciding whether i t is accompanied by impurities, many of whichhave a marked influence on the solubility.Whereas other physicalconstants are invariably determined for new substances, concern-ing many there are no solubility data, or at most a single valuefor some one temperature. This is, no doubt, partly due to thedifficulty attending solubility determinations by the methods gener-ally in use, usually modifications of Noyes’ or of Victor Meyer’smethod.When using Koyes’ mebhod, great difficulty is experi-enced in obtaining accurate results a t high temperatures, andalthough V. Meyer’s method gives results of sufficient accuracy, itrequires the use of a very large thermostat, which must be main-tained constant within 0*lo. A method and apparatus haverecently been described which greatly simplify the accurate deter-mination of solubilities a t high temperatures. The principle ofM 161 REP.-VOL. X162 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the method is the determination of solubilities a t the boiling pointof the saturated solution, the boiling point being varied by chang-ing the pressure. Conducting the determination a t the boilingpoint ensures thorough agitation and eliminat'es the necessity forusing a thermostat, since a t constant pressure the boiling pointis also constant.1The work of Bingham and his collaborators in improving themeans of determining viscosities accurately, yet quickly, and indrawing attention to a fundamental error which vitiated muchrecent work in this field, was referred to two years ago.2 In 1912they described a viscometer with which absolute viscosities couldbe measured with great certainty.That form of apparatus iseasily made, but since its dimensions must be accurately knownfor absolute measurements, the time consumed in calibration isconsiderable.3 For general purposes, it is preferable to calculatethe absolute viscosities from measurements that are only relative.By this procedure the calibration is simplified, and the apparatusmay be made simpler and less delicate t o handle.Many visco-meters have been devised for relative measurements, but relativemeasurements are comparatively useless unless the results can becalculated to absolute units. That measurements obtained by theuse of instruments of the Ostwald type could be calculated toabsolute units without difficulty has been shown to be an assump-tion not generally true, this being mainly due to the fact thatthe formula almost universally used takes no account of thO loss ofkinetic energy of the liquid within the capillary, this energy dis-appearing outside the capillary without helping t o overcome viscousresistance within i t .4 Viscometers of the ordinary type aredeficient, because the pressure producing the flow through thecapillary is not variable a t will. The result is that, with very fluidsubstances, the kinetic energy correction becomes large unavoid-ably, and with rather viscous substances the time of flow becomesintolerably long, necmsitating the use of several instruments.With a very long period of flow, the difficulties due t o cloggingwith dust particles become very great.5 The necessity of theknowledge of the exact density of the liquid a t each temperaturewhere a viscosity measurement is desired lessens the convenience ofthis type of instrument. Both the untrustworthiness and the1 L.A. Tschugaev and W. Chlopin, Zeitsch. anorg. Chem., 1914, 86, 154;A., ii, 348.Ann. Report, 1912, 195.E. C. Bingham and G. F. White, Zeitsch. physikal. Chem., 1912, 80, 670 ;E. C. Binghsm, T., 1913, 103, 959.M. P. Applebey, ibid., 1910, 97, 2000.A., 1912, ii, 1144ANALYTICAL CHEMISTRY. 163inconvenience of these instruments may bs avoided by usingvariable pressure, and an instrument working on this principle hasnow been described which makes it possible to determine theviscosity of any liquid with an error not exceeding 0.1 per cent.For more accurate work, absolute measurements must be made, asdata do not exist for standardising a relative instrument for amuch higher degree of precision. The instrument is standardisedon water at several temperatures, with hexane for very fluidliquids and with sugar solutions for very viscous ones.The instru-ment is so designed that the correction for kinetic energy is alwayssmall, and can therefore be calculated with sufficient accuracy fromroughly approximate measurements. Certain minor correctionsare necessary, one of them involving the density of the liquid, asdoes the correction for kinetic energy, but, as both these correctionsare very smaIl in a properly proportioned instrument, the densityneeds only t o be known approximately, which constitutes a great,advantage of the method.’jThe most useful contributions t o microchemical analysis duringthe year have been two papers dealing with such widely differentsubjects as elementary analysis of organic substances and theelectro-deposition of metals.The latter paper needs to be supple-mented by another, which is promised, dealing with such detailsas current density, time required for complete deposition, and com-position of electrolyte ; but the apparatus described leaves little tobe desired, since i t can bet easily and cheaply constructed, andserves for the deposition of 0.2 mg. of some metals with an errornot exceeding 1 per cent., and that in the presence of 100 timesas rnucli of another metal.’ Methods such as this cannot fail tolead to the adoption of microclieinical methods even in cases wherethere is no lack of material available for analysis, since suchmethods effect economy, not only of materials, but of the aiialyst’stime, and often, as in this case, of platinum. The author of theother paper cited, which describes and illustrates Pregl’s apparatusfor micro-elementary analysis, goes so far as t o predict Chat Pregl’smethods will become the normal methods of combustion analysis,the results being as exact as those obtained by careful work withlarger quantities, whilst the saving of time is very great.Incident-ally, this paper describes certain improved absorption tubes andother apparatus, the principles of which may find useful applicationeven in laboratories where i t may not be decided to adopt micro-met hods.*E. C. Bingham, J. Ind. Eng. Chem., 1914, 6, 233 ; A., ii, 342.7 R. Heinze, Zeitsch. angew. Chem., 1914, 27, 237 ; A., ii, 482.* J-.V. Dubsky, Chem. Zeit., 1914, 38, 505, 510; A., ii, 486164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,Gas Analysis.The iodine pentoxide method for the estimation of carbon mon-oxide has received much attention this year, one object commonto all the authors being reduction of the volume of gas which mustbe taken for the test. This object is most successfully achievedby Graham and Winmill,” who use a 20 C.C. Haldane burette and yetget results accurate to 0.02 per cent. Where the total quantity t obe estimated is of the order of 0.1 per cent., a more suitable methodis that of Sinnatt and Ctamer,lo which will determine such quanti-ties within about 0*001 per cent. when 2500 C.C. of gas are used inthe test. These authors determine, by Pettenkofer’s method, thecarbon dioxide produced by the oxidation of the carbon monoxide.Their results do not confirm the statement of Seidell11 and earlierworkers that higher and more accurate results are obtainable bydetermining the iodine liberated from the pentoxide.Eachmethod must be applied with care where the amount of carbonmonoxide to be estimated is small, but it is probable that theestimation of the carbon dioxide, using Sinnatt and Cramer’smethod, offers least difficulty where the concentration to be esti-mated is of the order stated and the analyst inexperienced in eithermethod. I n skilled hands, however, the estimation of the iodineby means of N/lOOO-thiosulphate can be used to determineaccurately a much smaller quantity of carbon monoxide.12 Thefurther statement of Sinnatt and Cramer, that there is no risk oferror in conducting the oxidation a t 160°, is unfortunate, although,no doubt, true when the carbon dioxide produced, and not theiodine liberated, is determined.That their results by the iodine-titration method were accurate, however, was solely due to thefact that hydrogen was absent from the gas undergoing analysis.Although it is known that hydrogen alone does not react withiodine pentoxide until a much higher temperature than looo isreached, occasional erratic results have led most users of the iodinepentoxide method to conduct the oxidation a t a temperature wellbelow looo. It has now been shown that, in the presence ofcarbon monoxide, hydrogen reacts with iodine pentoxide even a t90°, and the exact conditions under which the velocity of reactioncan be kept negligibly small, without unduly reducing thetemperature and increasing the time required for the oxidation ofthe carbon monoxide, have been determined.13 Yellow mercuricJ.I. Graham and T. F. Winmill, T., 1914,105, 1996.lo F. S. Sinnattand B. J. Cramer, Analyst, 1914, 39, 163; A , , ii, 383.l1 A. Seidell, J. Ind. Eng. Chm., 1914, 6, 321 ; A . , ii, 489.l2 G. N. Huntly, Analyst, 1914, 39, 169.l3 J. I. Graham and T. F. Winmill, Zoc. citANALYTICAL CHEMISTRY. 165oxide, contained in dark glass apparatus, has also been shown tobehave like iodine pentoxide as a selective oxidising agent,oxidising carbon monoxide quantitatively, but not attackingmethane a t lOOO.14A paper on the analysis of complex gas mixtures, issuing fromthe United States Bureau of Mines, introduces no novel principle,but combines several old ones in such a manner as to increasematerially the precision of technical analysis without great loss ofspeed.I n particular, it makes it possible to estimate accuratelythe hydrogen and paraffins in coal gas, and to determine the meanmolecular weight of the paraffins, which may. differ so much fromthat of methane that methods which assume the absence of higherparaffins may underestimate hydrogen by 3 per cent., and over-estimate the paraffins (calculated as methane) by a like amount.Carbon dioxide, olefines, and oxygen having been removed in theusual manner, hydrogen and carbon monoxide are oxidised bycopper oxide a t about 250°, and separately estimated from thecontraction due to combustion and further contraction on treat-ment with potassium hydroxide.The paraffins are then estimated,and their mean molecular weight determined by slow combustionwith oxygen, and measurement of the contraction and of thecarbon dioxide produced.15 It has been shown that the simul-t,aneous presence of cerium dioxide, already recommended as acatalyst in ordinary combustion analysis,lG has the property ofgreatly increasing the speed of oxidation of hydrogen by copperoxide, whilst i t does not bring about the oxidation of methane at,270O.17A recent paper on errors in gas analysis, due to assuming thatthe molecular volumes of all gases are alike, might have passedunnoticed not many years ago on the ground that the unavoidableerrors of experiment-at least in technical gas analysis-were largein proportion to those t o which attention is now directed.Technical methods of gas analysis have now, however, been soperfected that refinements in calculation, such as are suggested bythe authors of the paper referred to, are fully justified.18Iizorgaaic d nalysis.Qualitative.-Statements in the literature as to the seiisitivenessof various reagents for lead being conflicting, experiments havel4 L.Moser anci 0. Schmid, Zcitsch,. anal. ChC??Z., 1914, 53, 217 ; A . , ii, 384.l5 G. 13. Taylor, J . l n d . Eng. Chcm., 1914, 6, 845 ; A . , ii, 814.lS Ama. Repod, 1913, 178.17 J.P. Wibnut, Chcni. Wcekblad, 1914, 11, 498; A , , ii, 585.l8 G. A. Burrell and F. M. Seibert, U.S. Bureau of Mines, Technical Paper, 54166 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been conducted with a number of such reagents under conditionsas nearly as possible identical, and the results tabulated in a usefulform.19 The reaction of copper with 1 : Z-diaminoanthraquinone-3-sulphonic acid, described by UhlenhuthFO is not specific, but isgiven by nickel and cobalt also. At the same time, it has beenfound that a simple extension of the test, which is of ext'raordinarydelicacy, suffices to differentiate between these three metals.21A method that will detect aluminium in presence of 1000 timesits weight of iron is noteworthy. It depends on the solubility ofbarium aluminate, and i t is not unreasonable t o suppose that itmight be developed into a method for the approximate estimationof traces of aluminium.22Quantitative.-A new method of estimating bromide in presenceof chloride has been based on the fact that, under certain coil-ditions, telluric acid liberates bromine from bromides, but notchlorine from chlorides.The test results show that the method iscapable of yielding excellent results, and the authors have beencareful t o indicate thO conditions necessary to success, but, likemany other methods due to Gooch, a very slight departure fromthe conditions laid down may give rise to large errors, and already,in our own Journal, the method has been misdescribed in anessential particular.23I n view of the fact that every year slight modifications of oldmethods for the estimation of phosphoric acid are recommended,modifications which seem to serve no useful purpose, attentionmay be directed to a recent paper dealing with the Pemberton-Kilgore method, which depends on the precipitation of phosphoricacid as ammonium phosphomolybdate, solution of the washed pre-cipitate in excess of standard alkali, and titration of the excess ofalkali, using phenolphthalein as indicator.I n spite of manysources of error, the method gives results sufficiently accurate formany purposes if carried out by a chemist accustomed to use it,and saves much time when many determinatims have to be made.For occasional work it is likely to, prove slower, as well as muchless accurate, than the gravimetric (molybdate-magnesia) method.The paper referred to should show any chemist whether the methodis one suited to his circumstances.Some fifty cognate papers arecited.24l9 E. Eegriwe, Zeitsch. anal. Chem., 1914, 53, 420 ; A , , ii, 579.2o Ann. Report, 1910, 163.21 G. Malatesta and E. di Nola, Boll. Chiin. farm., 1913, 52, 819 ; A., ii, 220.22 G. H. Petit, J. Pharm. Chinz., 1914, [vii], 9, 66 ; A., ii, 221.z3 F. A. Gooch and H. I. Cole, Zeitsch. nnorg. Chem., 1914, 86, 401 ; Amer.24 P. L. Hubbard, J. Id. Eng. Chem., 1913, 5, 998 ; A., ii, 145.J. Sci., 1914, [iv], 37, 257 ; A., ji, 379ANALYTICAL CHEMISTRY. 167Several valuable papers dealing with the estimation of silica werepublished almost simultaneously early in the year.All the authorsare agreed that about 1 per cent. of silica is lost if only a singleevaporation with acid is made, that repeated evaporation withoutintermediate filtration is useless, but that all but a negligibletrace of the lost silica can be recovered by a single evaporation ofthe filtrate. This has perhaps been the prevailing view for someyears, but i t was not universally held. One paper deals with theinfluence of other acids than hydrochloric acid,25 whilst anothershows that the difficulty in igniting silica to constant weight isnot due to the obstinate retention of water, but to the fact that,at the temperature of the blowpipe flame, the solid impurities areslowly volatilised or partly decomposed.The chief impurity isusually sodium chloride, which, so far as it is not volatilised duringignition, is decomposed, with formation of sodium silicate, and i thas been propwed that when the silica has been finally treated withhydrofluoric and sulphuric acids, any sodium sulphate remainingshould be calculated to sodium oxide, and this amount deductedfrom the weight of crude “silica.”26 I n view of the volatility ofsodium chloride, a better course is to treat the silica before ignitionwith sulphuric acid to decompose chlorides. The weight of theresidue then obtained after treatment with hydrofluoric andsulphuric acids is the exact measure of the impurities weighed withthe silica.27The determination of silver in bullion, especially bullion high ingold and low in silver, by the cupellation method, is not as satis-factory as might be desired.The silver, being estimated by thedifference between the result of the total fine metal assay and thegold assay, bears the errors of both assays, which may not becompensating, and may be large in proportion to the silver present.Thus, differences of 5 fine are common bet’ween the results of twolaboratories, and even duplicates may differ by this amount, andthat on bullion only 100 to 200 fine in silver. Gay Lussac’s methodhas the advantage that, given proper equipment, a large amountof work can be completed daily; but, for accurate work, somewhat elaborate equipment is required, and the method is quiteunsuited f o r occasional work.28 A preliminary difficulty in apply-ing any wet method to bullion of the character referred to aboveis the solution of the silver.I n view of all these facts, consider-able interest attaches to a method which has been, and is still85 bl. Wunder and A. Suleimann, Ann. Chim. mznl., 1914, 19, 45 ; A . , ii, 292.?6 F. A. Goocli, F. C. Reckert, and S. 13. Kuzirian, Zeitsch. mzorg. Chem., 1914,27 S. B. Kuzirian, ibid., 430 ; Amw. J. Xci., 1914, [iv], 37, 61 ; A . , ii, 218.28 Ann. Report, 1913, 173.85, 230168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.being, investigated in the United States Mint with promisingresults, although its author is careful to state t h a t many detailsyet require investigation. The principle of the method is alloyingthe bullion with cadmium, as suggested a generation ago byBalling,29 solution of the silver in the alloy by means of nitricacid, and its estimation by Volhard's method.30The estimation of silver in colloidal silver preparations and inorganic tissue fluids presents some difficulty, which, however,appears t o be overcome by two methods recently de~cribed.3~A method recommended nearly twenty years ago for the separa-tion and estimation of arsenic32 has been modified, and the modifi-cation shown to be of very general application, neither bismuth,cadmium, tin, iron, chromium, nickel, cobalt, manganese, nor zincinterfering.Copper and aluminium in large amounts do interfere,but by a slight modification the method is applicable even t osolut.ions containing much copper.The method depends on theprecipitation of the arsenic in the elementary condition by additionof sodium hypophosphite t o the hydrochloric acid solution, withfiltration of the precipitate and estimation of the arsenic by aniodometric method. The recent modification consisk in treatingthe precipitate with an iodate-iodide mixture. Owing t o a traceof free iodine always present, the arsenic dissolves, slowly a t first,but more and more rapidly, since iodine is one of the products ofthe series of reactions which follow the solution of the arsenic.The net result of these reactions is that each atom of arsenic setsfree one atom of iodine, and the iodine thus liberated is titratedwith thiosulphate.33 It has been suggested that arsenic may belo& by volatilisation as chloride when following the abovemethod,34 but this fear is shown to be groundless.35 For the esti-mation of small quantities of arsenic in the presence of large quan-tities of copper, a purpose which the method just described does notfulfil, the methosd of Avery and Beans36 can now be confidentlyrecommended.It is far more rapid than any other availablemethod, and depends on the fact that the copper complex formedwhen an alkali tartrate and alkali hydrogen carbonate are added t o2D Compare Crookes' " Select Methods of Cheniical Analysis," 1886, 443.XI F. P. Dewey, J. Ind. Eng. Chem., 1914, 6, 650, 728; A., ii, 778.F. Lehmann, Arch. Pharm., 1914, 252, 9; A . , ii, 578 ; P. W. Danckwortt,ibid., 69 ; A., ii, 578.32 R.Engel and J. Bernard, Compt. rend., 1896, 122, 390 ; A . , 1896, ii, 448.L. Brandt, Chem. Zcit., 1913, 37, 1445, 1471, 1496; A , , ii, 68 ; ibid., 1914,38, 461, 474 ; A., ii, 383.34 L. W. Andrews, ibid., 295; A., ii, 291.35 L. Brandt, ibid., 295 ; A . , ii, 291.36 S. Avery and H. T. Beans, J. Amer. Chem. SOC., 1901, 23, 485; A., 1901,ii, 623ANALYTICAL CHEMISTRY. 169a cupric solution is without action on either potassium iodide oriodine.37An entirely novel method of estimating glucinum depends onthe fact t h a t basic glucinum acetate is readily sublimed a t160-170°/19 mm., whilst the basic acetates of iron and aluminiumare non-volatile in these circumstances.38 A paper embodying nonew principle, but of considerable practical utility, is one dealingwith the analysis of commercial aluminium and its light alloys. Aprimary difficulty in all such work is the separation of the largequantity of aluminium which must be taken in order t o get weigh-able quantities of the minor constituents.By a single operation,the author gets a clean separation of aluminium from everythingexcept tin and nickel, and the preliminary separation of nickel, ifpresent, and the subsequent separation of tin from aluminium,present no difficulty.39 Some years ago, Brandt proposed the useof diphenylcarbazide as internal indicator in the dichromate titra-tion of iron.40 The end-point is excellent, but the indicator-ofwhich i t is necessary t o use an appreciable amount-is itself areducing agent.The authors who made this observation succeededin establishing the method on a sound basis.41 A more recent pro-posal of Brandt to dispense with a proper correction for the re-ducing power of the indicator, and to make the method empirical,cannot be endorsed except f o r routine work on nearly uniformmaterial, but his proof that cornparatively large amounts of ter-valent arsenic do not interfere is important.42The methods for the separation of iron, aluminium, andchromium from manganese and zinc, based on the fact that thesalts of the former group of elements are strongly hydrolysed,whereas those of manganese and zinc are not, or have been sup-posed not t o be, have been studied by means of the ethyl diazo-acetate method for estimating the degree of hydrolysis.Solutionsof zinc chloride are not perceptibly hydrolysed, but manganesechloride, in millinormal solution at 2 5 O , is said to be hydrolysedto the extent of 10 per cent. It is said to follow from this thatacetate separations of manganese from iron can never be sharp, butthat the iron precipitate is always contaminated with manganese.43Whilst this may be literally true, and thus comforting t o thosewho have failed t o acquire skill in acetate separations, the fact37 G. D. Lander and J. J. Geake, Analyst, 1914, 39, 116 ; A., ii, 292.:EI A. Kling slid E. Gelin, Bull. SOC. chim., 1914, [iv], 15, 205 ; A., ii, 295.39 I<. Belnsio, Ann. Chim. Applicnta, 1914, 1, 101 ; A., ii, 388.-10 L. Brandt, Zeitsch.anal. Chem., 1906, 45, 95 ; A., 1906, ii, 309.41 0. L. Barnebey and S. R. Wilson, J. Amcr. Chenz. Soc., 1913, 35, 156 ; A.,4) G. van Pelt, Bull. SOC. chint. Belg., 1914, 28, 101 ; A , , ii, 492.1913, ii, 248. -Iz L. Rrandt, Zeitsch. nnal. Chem., 1914, 53, 1 ; A., ii, 71170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.remains that many chemists do make such separations withsufficient sharpness for all practical purposes. That others fail, how-ever, when attempting t o follow the directions given by successfulusers of the method, is sufficient evidence that those directions areincomplete in some essential detail, and the paper under reviewshould be useful t o the chemist, who may some day be expectedto describe the essential features of this method as successfully asmany practise it to-day.Although manganese is generally estimated to-day by volumetricmethods, which leave nothing to be desired in point of accuracy,it is sometimes necessary t o separate manganese from other metals,and a recent paper on the conditions which determine the separa-tion of manganese sulphide in the dense green form, which canbe easily filtered and washed, should prove usefu1.44 A very oldmethod for the estimation of zinc in coinage bronze, which wassupposed t o have been finally discredited half a century ago, hasbeen revived a t the Royal Mint and shown t o be as accurate asother available processes, whilst the saving in time is very great.The method consists in volatilising the zinc, while protecting themetal against oxidation.The use of proof assays is necessary, asis a high temperature ( 1 3 7 5 O ) , such as was not so readily obtain-able in laboratory furnaces a t the date when the method fell intodi~use.~5A new method for the estimation of cobalt in steel depends onthe fact that when iron is precipitated by zinc oxide, as inVolhard’s method for manganese, but avoiding any unnecessaryexcess of the reagent, any cobalt (and nickel) present remains insolution, whereas chromium, vanadium, molybdenum, titanium,aluminium, copper, and silica are wholly precipitated. Cobalt isfinally separated from nickel and manganese by precipitation withnitroso-&naphthol in presence of so much hydrochloric acid thatnickel is held in soIution.46 Round the dimethylglyoxime methodfor the estimation of nickel47 a considerable literature has sprungup, and attent’ion may be called to a summary, by its author, ofthe more useful suggestions, and a reply to some criticisms whichprove t o be unfounded.4*Owing t o the increasing value of platinum-iridium alloys andto the large number of industrial purposes t o which these alloys arenow being applied, the accurate estimation of iridium is of con-siderable importance, and attention may be directed to two entirely44 A. Villiers, Conzpt.rend., 1914, 159, 67 ; A . , ii, 658.45 1’. li. Rose, J. Soc. Chem. Ind., 1914, 33, 170 ; A . , ii, 385.G. Slawik, Chem. Zeit., 1914, 38, 514 ; A . , ii, 494.47 Anm. Report, 1907, 205.48 0. Brunck, Zeitsch.angew. Chem., 1914, 27, 315 ; A . , ii, 583ANALYTICAL CHEMISTRY. 171satisfactory methods which have been reported on under theanalytical investigation scheme of the Society of Public Anal~st;s.~~One of the authors of this report is also partly responsible forsome very interesting notes on the differentiation of platinum-iridium and platinum-rhodium alloys, advantage being taken ofthe fact that, in the presence of small quantities of rhodium, thetendency of silver cupellation leads to spit or vegetate is greatlyincreased.50 A useful method for the determination of the purityof platinum ware depends on the fact that the thermoelectromotiveforce of platinum against many of its alloys has been determinedwith considerable exactness. Unlike the very exact method cle-pending on measurement of temperature-coefficient of electricalresistance, which is only applicable to wires, the new method canbe applied to vessels of any form, and without defacing them.61As one of the two rapid methods for the estimation of thoriumis not generally available, owing to the fact that the reagent-sodium hypophosphate-cannot be purchased, more importancethan would otherwise be the case attaches t o a new method whichdepends on the insolubility of thorium pyrophosphate in diluteacids, the pyrophosphates of the other rare earths, includingcerous (but not ceric) cerium, being soluble.52 It has been observedthat when the rare earths are precipitated as hydroxides andignited to oxides, the results are always somewhat higher, andsometimes much higher, than when they are precipitated as oxalatesand ignited.Moreover, the former method gives less concordantresults, suggesting the possible formation of basic salts, the amountof which might be expected to vary with the experimental condi-tions. On the other hand, there was a doubt whether the oxalateprecipitation wils complete in presence of a trace of mineral acid.This doubt is finally dispelled by a recent research, which showsoxalic acid to be a better precipitant than ammonium oxalate.The latter tends to be carried down as a complex oxalate, which,on washing, is hydrolysed, with the production of rare earth oxalateso finely divided that it passes through the filter. Ammonia doesgive rise to small quantities of basic salt, but it is only whenthe hydroxides of the fixed alkalis are used that serious errors areencountered, and these are mainly due to the retention of alkaliby the precipitate.&F o r the estimation of quantities of titanium of the order of49 C.0. Bannister and E. A. Du Vergier, Analyst, 1914, 39, 340 ; A . , ii, 748.50 C. 0. Banni3ter and Patchin, Inst. Mining and Me~nllurgy, 1913, Bull. 111.51 G. 1<. Burgess and P. D. Sale, J. Ind. Eng. Chem., 1914, 6, 452 ; A . , ii, 585.52 R. J. Carney and E. I). Ccimpbell, J. Amer. Chem. sbc., 1914, 36, 1134;6s T. 0. Smith and C. James, Chem, News, 1914,109, 219 ; A , , ii, 492.A . , ii, 583172 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.10 mg. with an accuracy of 2 per cent., a method described someyears ago in an obscure journal has been subjected t o a criticalinvestigation, and shown to be serviceable.It depends on theprecipitation of titanium phosphate in acid solution, after reducingiron t o the ferrous state.54 For the inore exact separation of largerquantities of titanium and iron, Gooch's method was until recentlymuch used. It depended on precipitation of the iron as sulphidein presence of tartaric acid, which had then to' be destroyed beforethe titanium could be precipitated by the usual reagents. Destruc-tion of the tartaric acid by pernianganate, as Gooch directs, gener-ally leads to co-precipitation of manganese when the attempt ismade t o precipitate the titania by the hydrolysis of the acetate,and a second separation is thus necessitated.This tedious pro-cedure is no longer necessary, since i t has been found thatBaudisch's reagent (the ammonium salt of nitrosophenylhydroxyl-amine) will precipitate titanium from solutions containing largequantities of tartaric acid.55 A similar method serves for theseparation of zirconium from iron and al~minium.5~Tungsten of more than 99 per cent. purity is now a comrnoiiobject of commerce, and is use'd in so large a proportion in somehigh-speed steels that the exact determination of the impurities isimportant. When the total impurities range from 5 per cent.down to 0.2 per cent., large quantities of metal must be taken forthe estimation of the minor constituents, and bringing these largequantities of tungsten into solution introduces a preliminarydifficulty.Several alternative methods of bringing the metal intosolution are described in a recent paper, which also shows the greatvariety of impurities that may be present, and how best to estimateeach .57Am'ong many papers dealing with the estimation of carbon insteel and iron, attention may be directed t o a critical investigationof the comparatively little used method which depends on directcombustion, absorption of the resulting carbon dioxide by means ofbarium hydroxide, filtration and washing of the precipitatedbarium carbonate out of contact with air, solution in a measuredvolume of standard hydrochloric acid, and titration of the excessof acid with alkali. The manipulation of the precipitate requiresspecial apparatus, but this is readily assembled, and the publishedresults show t h a t the method is as exact as the gravimetric methods.54 G.S. Jamieson, J. Ind. Eng. Chem., 1914, 6, 203 ; A., ii, 298.55 W. M. Thornton, jun. and E. M. Hayden, jun., Zeitsch. anorg. Chem., 1914,56 Ibid., Chenz. News, 1914, 110, 153 ; Amer. J. Sci., 1914, [iv], 38, 137;57 H. Arnold, Zeitsch. nnorg. Chcm., 1914, 88, 74; A., ii, 679,86, 407 ; Amer. J. Sci., 1914, [iv], 37, 407; A., ii, 553.A . , ii, 779ANALYTICAL CHEMISTRY. 173Its advantages, as compared with the use of weighed potash bulbs,are obvious, whilst i t is not subject t o error from access of sulphurtrioxide, as is the gravimetric barium carbonate method, which has,nevertheless, found extended adoption.58Electrochemical A nalysis.General interest attaches to new devices which make it possibleto conduct electrochemical analysis with a minimum expenditureon platinum app-aratus.Attention may be directed to a cheapform of rotating cathode and anode suitable for the rapid estinia-tion of copper and zinc. Not only is it so designed as t o re'ducethe necessary amount of platinum to about 1 gram, but the shapeof the anode ensures thorough mixing.59 Fine-meshed brass gauzehas also been shown to be suitable material for the construction ofcathodes for t$e estimation of copper, zinc, and nickel, about1 gram of platinum wire serving as an0de.m Tantalum electrodes,recommendeld two or three years ago,61 have been stated t o becomebrittle in use62 and t o give unsatisfactory results.63 It is nowshown that they do not become brittle unless relatively highcurrent densities are used, and that the results with tantalumgauze electrodes, now obtainable, are in no way inferior to thoseobtained with platinum gauze.64It was stated some years ago that copper could be separatedfrom an equal weight of arsenic either from ammoniacal or nitricacid solution.65 It is now shown that this is only true when thearsenic is present in the arsenic condition,66 and that it is prefer-able to work with ammoniacal solutions, as much higher currentdensities may then be used, and no sensible error is introduced byprolonging the operation long after all the copper has been de-posited, in marked contrast to the behaviour of nitric acid solu-t i o n ~ .~ ~ The conditions requisite for the deposition of bismuth ina satisfactorily adherent condition, and for the separation of thatmetal from arsenic, cadmium, and lead, have now been defined withsome precision. The author of this work, in which measurements58 J. R. Cain, J. Ind. Eng. Chem., 1914, 6 , 465 ; A., ii, 577.59 E. A. Lewis, J. SOC. Chcm. Ind., 1914, 33, 445 ; A . , ii, 483.D. F. Calhane and T. C. Wheaton, kfet. and Chcm. Ewg., 1914,12, 87.0. Brunck, Chem. Zeit., 1912, 36, 1233 ; A., 1912, ii, 1128.65 G. Oesterheld, Zeitsch. EZektrochem., 1913, 19, 585 ; A., 1913, ii, 823.6* G. Wegelin, Chem. Zeit., 1913, 37, 989 ; A . , 1913, ii, 880.65 D. S . Ashbrook, J.Amcr. Chem. SOC., 1904, 26, 1285 ; A . , 1905, ii, 64.66 B. P. Richardson, Zeitsch. anorg. Chem., 1913, 84, 277 ; A., ii, 148 ;0. Blunck, ibid., 1914, 38, 565; A . , ii, 482.A. Sieverts and W. Wippelmann, ibid., 1914, 87, 169 ; A . , ii, 580.Sieverts and Wippelmann, loc. cit174 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of cathode potential proved invaluable, suggesk that in many cases-once a separation has been shown to be possible and has beenstudied with the aid of cathode potential measurements-it shouldbe possible t o dispense with the elaborate and costly appliancesrequired for measuring cathode potential, and where possible thisis certainly desirable.G8The electrolytic reduction of ferric iron as a preIiminary t otitration with permanganate has been made the subject of study,and it is shown that quantitative reduction can be secured in afew minutes by simple means.Chlorides do not interfere, and awide range of acidity is permissible.69Attempts have been made to estimate small quantities ofalkaloids by an electrochemical method of the type made familiarby.the work of Dutoit and Duboux. A solution of the alkaloidcontaining an excess of hydrochloric acid is titrateld with sodiumhydroxide solution of known strength, the electrical conductivityof the solution being measured after each small addition. Theresults when plotted on a system of rectangular co-ordinates givea curve consisting of three well-defined portions, the first repre-senting the neutralisation of the free acid, the second the dis-placement curve characteristic of the alkaloid, and the third theincrease of conductivity due to excess of sodium hydroxide.Bycomparison with curves obtained with solutions of known composi-tion, small quantities of alkaloids may be estimated.70Organic Analysis.Experience shows that few qualitative tests sustain the claimsmade for them. This is particularly the case with tests whichare a t first claimed to be specific. Tests for which less is claimed,on the other hand, frequently prove useful. Such a one is thatwhich depends on a colour reaction with trichloroacetic acid. Sofar as the evidence goes, it appears that trichloroacetic acid con-stitutes, equally with tetranitromethane, a reagent for cyclic doublelinkings.71 A test which differentiates between morphine on theone hand and codeine and dionine on the other, and which servesto detect 0.02 mg.of morphine, is deserving of notice, more especi-ally as it has been shown that a dozen or more other commonalkaloids do not give a similar reaction.72 A reaction apparentlycharacteristic of malonic acid and its esters, and certainly notgiven by acetoacetic and dicarboxyglutaconic esters, depends on68 B. P. Richardson, Zoc. cit.6y H. C. Allen, J. Amer. Chem. Soc., 1914, 36, 937 ; A , , ii, 581.7.1 K. Goubau, Bull. Acad. roy. Belg., 1914, 63 ; A . , ii, 394.‘il K. V. Charitschkov, J. Russ. Phys. Chem. Soc., 1914, 46, 76 ; A , , ii, S90.72 T. H. Oliver, Chm. and Drug., 1914, 85, 249ANALYTICAL CHEMISTRY.175the development of an intense blue fluorescence when the substance,in alcoholic solution, is heated with hydrochloric acid, and themixture then neutralised, mixed with an alcoholic solution ofw-bromomethylfurfuraldehyde, and finally rendered alkaline withalcoholic pota;sium hydroxide.73For the combustion analysis of organic compounds by Dennstedt’smethod, a furnace electrically heated internally by means ofplatinum wires has been designed.74 A volumetric method hasbeen described for the determination of total carbon in aliphaticsubstances in the wet way. It is based on oxidation of the sub-stance by potassium dichromate and phosphoric acid to carbondioxide, or a mixture of carbon dioxide and acetic acid, the carbondioxide being measured, and the acetic acid distilled from theresidual liquid and titrated with baryta.An advantage of themethold is the small quantity of the substance required.75 Thedirect method for the estimation of oxygen in organic compounds,referred to last year,76 has been found to give erroneous resultswhen applied to substances of comparatively low oxygen content,but a new method of universal application has now been workedout by the same author. Unfortunately, it is somewhat elaborate,but the value of a direct and exact determination of oxygen issometimes very great.77A novel method for the estimation of halogens in organic com-pounds consists in dissolving the substance in alcohol, adding asmall quantity of a dilute solution of an alkali hydroxide, and1-2 grams of calcium carbonate coated with finely divided palla-dium.The air is displaced by hydrogen, and the reduction com-pleted in a shaking apparatus in an atmosphere of hydrogenunder pressure. The halogen is determined by the usual methodsin the filtrate from the catalyst, which may be used several times.78Vanadium pentoxide, recommended last year as a catalystin the absorption of gaseous olefines by sulphuric acid,79 is nowrecommended in a similar capacity in Kjeldahl’s method of decom-posing organic compounds as a preliminary t o the estimation ofnitrogen.80 Attention has been called to some limitations ofKjeldahl’s method by two physiologists whose work dealt with a73 H. J. H. Penton, Proc. Camb. Phil. Soc., 1914, 17, 477 ; A., ii., 686.n C.Milchsack and MT. A. Roth, Zeitsch. nnyew. C‘hem. , -1914, 27, 5 ; A., ii, 147.75 E. C. Grey, T., 1914, 105, 2204.77 M. C. Boswell, J. Amer. Chem. Soc., 1914, 36, 127 ; A . , ii, 142.7* M. Busch, Zeitsch. angew. Chern., 1914, 27, 432.7g Ann. Report, 1913, 168.8o L. Marino and F. Gonnelli, Atti R. Accad. Lincei, 1914, [v], 23, i, 523 ;Ann. Report, 1913, 178.A . , ii, 575176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.number of compounds not covered by Dyer in his report on thatprocess twenty years ago.81The addition of acetic anhydride or of phenol in the estimationof methoxyl by Zeisel’s method, as recommended by Herzig andWeishut respectively,82 has been stated to introduce a source oferror, for in the absence of anything but the acetic anhydride orphenol and hydriodic acid, silver iodide may be formed.83 It hassince been shown, however, that the errors thus introduced,although real, are negligible compared with the unavoidable ex-perimental error of the method.84 The estimation of methoxyl byZeisel’s method in the presence of sulphur compounds is extremelyunsatisfactory, on account of tlie formation of silver sulphide inthe absorption flasks.A method has now been devised for theabsorption and estimation of the methyl iodide, based on the factthat this substance combines with pyridine, forming pyridinemethiodide, which latter may be titrated with silver solution,using sodium chromate as indicator.B5A quantitative separation of acetaldehyde and acetone has beenbased on the fact that t’he former is quantitatively oxidised by analkaline silver solution, whilst acetone is scarcely affected.86 Anew method for the estimation of acetone in acetone-water mix-tures depends on the fact that two phases separate when sufficientpotassium fluoride is added to such mixtures.87 The method isessentially identical with one previously described for the estima-tion of alcohol in admixture with water.88 A gasometric methodfor the estimation of formic acid depends on the fact that, inthe presence of a trace of sulphuric acid, formic acid reach quan-titatively with acetic anhydride, with the production of aceticacid and carbon monoxide.89Mannitol has been estimated hitherto either by the method ofGayon and Dubourg90 or by that of Muller.91 The former consistsessentially in concentration of the solution until mannitol crystal-lises, treatment of the magma with a saturated solution ofmannitol, followed by filtration, and final extraction of theH.I). Dakin and H. W. Dudley, J. Biol. Chsm., 1914, 17, 275 ; A , , ii, 381.R. J. Manning and M. Nierenstein, Ber., 1913, 46, 3983 ; A., ii, 150.G. Goldschmiedt, ibid., 1914, 47, 389; A., ii, 223.82 Ann. Report, 1913, 179.85 A. Kirpal and T. Biihn, ibid., 1084 ; A . , ii, 497.86 E. Hagglund, Zeitsch. anal. Chem., 1914, 53, 433 ; A., ii, 592.G. B. Frankforter and L. Cohen, J. Amer. Chem. Soc., 1914, 36, 1103; A.,ii, 548.8(1 Ann. Report, 1912, 213.89 V. Hottenroth, Chem. Zeit., 1914, 38, 598 ; A., ii, 501.91 Bzcll.SOC. chim., 1894, [iiiJ, 11, 329, 1073 ; A., 1894, ii, 1 4 1 , 334.Ann. Inst. Pasteur, 1894, 8, 108ANALYTICAL CHEMISTRY. 1’77inannit01 from the dry contents of the filter by means of hotalcohol. The limitations of such a method are obvious. Muller’smethod, depending on the fact that the rotatory power of anaqueous solution of mannitol is notably raised by saturating thesolution with borax, is troublesome, since sugars must first befermented, tartrates and malates removed, and a correction madefor gly,cerol, which, if present, combines with some of the boraxand minimises the effect of a fixed quantity of the latter, but itgives excellent results with wines. I n the presence of some othersubstances, such as yeast-water, often employed as nitrogenous foodfor yeast or bacteria in fermentation experiments, the method failsutterly, and this lends additional importance to a new methodwhich is free from this objection.It is modelled on Wagenaar’smethod for the estimation of glycerol, and depends on the capacitypossessed by polyhydric alcohols of holding cupric hydroxide insolution. The method is invalidated only by the presence of otherhexitols.92 The sugars most commonly found in glucosides, apartfrom dextrose, are &galactose, dmannose, and members of themethyl pentose group, generally rhamnose, often also rhodeose.Simple pentoses are rarely met with. Dextrose may be character-ised by fermentation, galactose is precipitated almost quanti-tatively by phenylmethylhydrazine, mannose by phenylhydrazine,arabinose by diphenylhydrazine.A recent method for the estima-tion of rhamnose depends on the formation of a cyanoliydrin withhydrocyanic acid, which is easily converted by saponification intoa-rhamnohexonic acid (or its lactone), which in turn yields mucicacid on oxidation by nitric acid. The principle of the methodmight have suggested ikelf to anyone, but no confidence can beplaced in a method depending on oxidation t o muck acid until ithas been shown to give constant results. The oxidation ofa-rhamnohexonic acid to mucic acid does not appear to be quantita-tive, but there is a fixed relation between the rhamnose originallypresent and the weight of mucic acid formed, and this relation isbut slightly disturbed by the simultaneous presence of an equalquantity of rhodeose, and in many cases the disturbing influenceof rhodeose is negligible, for example, when the purpose in viewis the determination of the molecular proportions of a mixture ofmethyl pentoses, for which an exact method is unnecessary.93 Ithas been found that when dilute hydrochloric acid acts on hexoses,starch, and cellulose, o-hydroxy-5-methyl-2-furf uraldehyde isformed to the extent of 1-2 per cent.Although it is precipitatedby phloroglucinol, i t does not interfere with the accuracy of92 J. Smit, Zeitsch. ccnal. Chem., 1914, 53, 473 ; A,, ii, 683.93 E. VotoEek and R. PotrnBi5i1, BUZZ. Soc. chim., 1914, [iv], 15, 634 ; A., ii,REP.-VOL. XI. N683178 ANNUAL REPORTS ON THE PROGRESS OF CHEhfISTRY.pentosan estimations made by the phloroglucinol method, providedaniline acetate is used as indicator.This is accounted f o r on theground of the slowness with which the o-hydroxymethylfurfur-aldehyde is produced. The recognition of this substance, however,renders previous estimations of methyl pentosans of doubtfulvalue.94ThO formation of a sparingly soluble compound with xanth-hydro1 has been used f o r the detection of carbamide in extremelydilute solutions, and its low solubility, together with its high mole-cular weight-seven times that of carbamide-aff ords an excel-lent means for the gravimeti-ic estimation of carbamide by directprecipitation.95 The gravimetric method possesses the advantageover methods depending on decomposition in the fact that carb-amide may a t the same time be definitely characterised, and thepurity of the derivative confirmed by analysis.When a solutionof semicarbazide hydrochloride is treated with potassium chlorateand hydrochloric acid, i t is decomposed, with the liberation ofexactly two-thirds of its nitrogen in the elementary condition, theremaining third being fixed as ammonium chloride. As carbamide,under similar conditions, is unacted on, the reaction affords a meansof estimating semicarbazide in the presence of ~arbamide.9~I n applying the double polarisation method t o beet molasses, thedirect reading is taken in an alkaline solution (owing to the excessof basic lead acetate remaining after clarification), and the in-version reading in an acid medium; the difference between the twoobservations is not duel solely to sucrose, since the rotation of theoptically active impurities is modified by the change of reaction toan appreciable In order t o avoid this error, it has beenproposed t o make the direct polarisation in presence of the sameamount of citric acid as in the inversion observation, clarificationbeing effected by means of bromine, the excess of which is shownto be without action on the sucrose or invert sugar.98 The resultsare about 1 per cent. higher than those obtained by the ordinaryprocedure involving the direct reading in alkaline solution, but theyare substantially identical with those obtained by the improvedmethods referred t o in last year’s Report.98aThere are still no British data bearing on the cryo,wopic methodof detecting added water in milk,gQ but the method has been muchg4 Miss M.Cunningham and C. Dorde, Biochem. J., 1914, 8, 438 ; A . , ii, 788.95 R. Fosse, Compt. rend., 1914, 158, 1076 ; A . , ii, 506.g6 R. L. Datta, J. Amer. Chem. Xoc., 1914, 36, 1014 ; A . , ii, 504.97 Ann. Report, 1913, 182.98 V. StanGk, Zeitsch. Zuckerind. Bohnt., 1914, 38, 429 ; A., ii, 586.98a Ann. Report, 1913, 182.By Ibid., 1910, 177 ; 1911, 173 ; 1912, 214; 1913, 183ANALYTICAL CHEMISTRY. 179discussed in Holland,l and a single Anglo-Indian writer speakshighly of i t . 2The methods of Lendrich and Nottbohm and of Katz for theestimation of caffeine in coffee are trustworthy, but tedious, and arecent method which gives identical results, and is somewhatquicker, is therefore deserving of notice, although embodying nonew principle.3 A new method for the estimation of nicotine in thepresence of ammonia depends on the fact that in alcoholic solutionnicotine behaves towards picric acid as a monacid base, whereas inaqueous solution it forms a dipicrate.4 Until quite recently nomethod was known for the estimation of strychnine in the presenceof quinine with any approach to exactness.A method, whichleaves little to be desired in point of accuracy, has now beendescribed, depending on separation of strychnine' as f err~cyanide.~Polenske's method of detecting beef fat in lard by the differencebetween the melting and the solidification points of the fatsC hasbeen shown to depend mainly on the fact that the a-palmitodistearinof lard has a difference-value greater than 18, whilst the P-palmito-distearin of beef fat has a difference-value of less than 12.Themethod will detect 15-20 per cent. of beef fat in lard.' A recentmethod, said to be capable of detecting 5-10 per cent., depends onthe differences in the melting points of the characteristic glyceridesof lard and of beef fat as compared with the melting points of therespective fatty acids. The difference between the melting pointsof a-palmitodistearin and its separated fatty acids is more than5O, whilst in the case of P-palmitodistearin the difference is only0.lo.* This method is only a year old, and is not universallyapproved,g but the most recent report on i t by authors independentof its inventor, states that 5 per cent.of be'ef fat can usually bedetected, and justifies one in the hope that a real step has a t lastbeen taken towards the solution of a very difficult problem.1°It has long been known that when to any of the higher fattyacids any other of the higher fatty acids is added in amouiit up t o20 per cent., the depression of the melting point is proportional toCJLCWL. IVeckblnd, 1914, 11, 126, 198, 201, 201, 206, 207, 209, 323; A., ii, 169,J . W. Leather, Annlyst., 1914, 39, 432.R. Spallino, Ouzzeltn, 1913, 43, ii, 493 ; A., 1913, ii, 1086.E. Polenslie, Aybeit. a. d. Kniserl. Cesundheitsmrnte, 1907, 26, 444.A. Bomer and R.Limprich, Zeitsch. Xnhr. Genitssm., 1913, 25, 367 ; A., 1913,A. Bomer, ibid., 26, 559.K. Fischer and J. Wewerinke, ibid., 1914, 27, 361.304, 392.a G. Pendler and W. Stiiber, Zeitsch. A ' ~ L T . Geizusbin., 1914, 28, 9 ; A., ii, 757.ti C. Simmonds, Analyst, 1914, 39, 81 ; A . , ii, 307.ii, 444.lo H. Sprinkmnyer aiid A. Diedrichs, ibicZ., 571.N 180 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the amount of the added acid, and almost independent of its kind.Advantage is taken of this fact in a methobd recently proposed fordetermining the composition of mixtures of the higher fatty acids.For the estimation of palmitic acid, for example, 20 parts of themixture to be analysed are added t o 80 parts of pure palmiticacid, and the melting point is determined.By reference to a table,the percentage of palmitic acid and of acids other than palmiticacid in the final mixture is given, and thus the percentage ofpalmitic acid, if any, in the mixture t o be analysed. Stearic,behenic, and other acids are estimated similarly. Extensions ofthe method consist in separating the solid fatty acids from a mix-ture and examining them as described, and also in hydrogenatingthe original fatty acids by the method of Sabatier and Senderens,and examining the hardened product by the melting-point method,It is possible by methods such as these to show, for example, thatthe fatty acids of cottonseed oil consist as t o 70 per cent. of un-saturated acids with 18 carbon atoms, and as t o 25 per cent.ofpalmitic acid, whilst stearic acid and unsaturated acids with 16carbon atoms can be shown to be ahsent.llA recent method for the stirnation of rosin in varnishes, oils,and soaps embodies no new principle, but the tabulated resultsshow that i t gives results a t least as accurate as any previousmethod, whilst it is simpler and much more rapid.12The proposal to estimate water in moist alcohol by observing theclouding point of mixtures with other liquids is not new, but noneof the methods hitherto based on this principle has proved satis-factory in practice. A recent method of this kind, which makesuse of a-bromonaphthalene, a substance readily obtained in asufficient state of purity for this purpose, makes it easy to det’er-mine 1-10 per cent.of water in alcohol within 0.02 per cent.l3The method employed for the determination of the originalgravity of beer is a purely empirical one, based on the observedrelation, in a great number of instances, of the “spirit indication ”to the “degrees of gravity lost.’’ It has been known for manyyears that the table contained in the First Schedule t o the InlandRevenue Act, 1880, was seriously inaccurate over an important, partof its range, and, in 1909-1911, Sir Edward Thorpe, on behalf ofthe Treasury, and Dr. H. T. Brown, representing the industry con-cerned, carried out an investigation with a view to collecting dataon which to construct a new table of Original Gravities. Thistable has just been given Parliamentary sanction,’* and full detailsl2 H.Wolff and E. Scholze, Chem. Zeit., 1914, 38, 369 ; A., ii, 393.1s Miss M. Jones and A. Lapworth, T., 1914, 105, 1804.l4 Finance Act, 1914 (Session 2).E. Twitchell, J. Ind. Eng. Chem., 1914, 6, 564; A., ii, 655ANALYTICAL CHEMISTRY. 181of Thorpe and Brown’s work have now been published,l5 whilst a tthe same time Brown has published a history of previous tables oforiginal gravity, a comparison of these with the new table, and areport on the scientific principles underlying the empirical methodof determining original gravity.16Although impossible to summarise in a paragraph, reference mustbe made to a series of papers on the analysis of mixtures of naturalwith artificial asphaltum, papers which materially add to ourknowledge of the chemistry of asphaltum, and take account of allrecent German work on the subject.17 Their value is t o someextent diminished by the fact that the author ignores the work ofClifford Richardson, and indeed of all American writers on thissubject.Agricultimxl Chemistry.Since Veitch’s method for the estimation of the lime requirenleiitof soils18 requires a t least six independent experiments, and givesmuch trouble with certain types of soil, an older and simplermethod,l9 long since abandoned as misleading, has been modified,and in its new form recommended as giving results substantiallyidentical with those obtained by Veitch’s method.20 Unfortunately,there is already evidence that this is not the case,21 and until theauthors meet the criticism which has been directed against theirmethod, that of Veitch, with all its shortcomings, is likely to bepreferred. Admittedly unsatisfactory, Veitch’s method has prob-ably been of more service than any other of the many methodsdescribed hitherto.The writer will hazard the opinion, however,that it and other methods are destined t o give way to a methodquite recently described. This method depends on treatment of thesoil with N/50-calcium hydrogen carbonate, and titration of analiquot portion of the filtrate. The principle seems unassailable,the technique is of the simplest, and the results are said to be con-firmed by pot and field experiments.21aMeasuring the capillary lift of soils is not analytical chemistry,but it seems right to call attention here to a recent paper whichshows how such measurements can be satisfactorily carried out withapparatus available in most analytical laboratories.22l5 Sir T.E. Thorpe iind H. T. Brown, J. Znst. Brewzkng, 1914, 20, 569.l6 11. T’. Browu, ibid., 645.l7 J. Marcusson, Chem Zcit., 1908, 32, 965 ; Client. Rev. Fett. Harz-Ind., 1911,18, 47 ; Zeilsch. angew. Chem., 1913, 26, 91 ; Chern. Zeit., 1914, 38, 813, 822.F. P. Veitch, J. Anaey. Chem. SOC., 1902, 24, 1120 ; A., 1903, ii, 400.11) Albert, Zeitsch. nngew. Chtm., 1888, 1, 533.1u J. A. Bizzell and T. L. Lyon, J. Ind. Eng. Chem., 1913, 5, 1011 ; A., ii, 150.21 C. R. Moulton and P. F. Trowbridge, ibid., 1914, 6, 835 ; A., ii, 828.‘Lia H. B. Hutchinson and K. MacLeniian, Chem. News, 1914, 110, 61 ; A., ii, 784.C.J. Lynde and H. A. DuprB, J. Amer. Soc. Ayronom., 1913, 5, 107182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Almost the only papers dealing with the analysis of plantmaterial are dated from Rothamsted. Continuing their re-~earches,~3 the workers of this school have determined the cupricreducing power of xylose and arabinose,04 and have contributed avaluable paper on the estimation of starch. For the estimation ofstarch in plant materials, the modified Sachsse method, which isofficial in the United States,25 and is based on the hydrolysis ofstarch by means of boiling dilute hydrochloric acid, is quite value-less, not only because such tissues invariably contain pentosansand other substances that yield reducing sugars on hydrolysis, butbecause of the actual destruction of dextrose which occurs duringthe prolonged treatment with acid.Although ordinary diastasegives with purified starch results by O’Sullivan’s methold 26 whichare approximately correct, values 15 to 20 per cent. lower than theactual starch content may be obtained when it is applied to leafmaterial or plant tissues in general, owing to the loss of dextrinwhich occurs during the purification of the solution by means ofbasic lead acetate. The observation that basic lead acetate, whichdoes not of itself precipitate dextrin, does carry it down if certainother substances are present, is important to others besides agri-cultural chemists. For the estimation of starch in plant material,an entirely satisfactory method has been based on Hill’s observa-tion 2.7 that taka-diastase converts starch wholly into maltose anddextrose. The paper includes valuable evidence of the rela-tively enormous errors that may be introduced in work of thiskind unless the greatest care be taken to ensure that the sampletaken for analysis is a representative one.I n the estimation ofstarch in dried, ground leaf material, tipping a portion of thesample out of the bottle for analysis, instead of turning the wholesample out, may result in the starch being underestimated by 20per cent., the heavy starch granules tending to sink to the bottomof the bottle.28The preparation of neutral solutions of ammonium citrate andtheir use in the analysis of phosphatic manures, which were referredt o somewhat fully two years ag0,29 have received much attentionduring the year under review.As regards the preparation of thesolution, i t has been shown that a deviation of 0.5 per cent. fromthe ammonia: citric acid ratio given by Patten and Marti30 isnegligible,31 whilst a simple method of controlling the hydrion-con-29 Ann. Report, 1913, 185.as C. O’Sullivan, Y‘., 1884, 45, 1.29 Ann. Beport, 19’12, 218.A. J. Daish, J. Agric. Sci., 1914, 6, 255.27 A. C. Hill, P., 1901, 17, 184.U.S. Bureau of Chemistry, Bull. No. 107.W. A. Davis and A. J. Daish, J. Agric. Sci., 1914, 6, 152 ; A . , ii, 588.P. Rudnick and W. L. Latshaw, J. Ind. Eng. Chem., 1913, 5, 998 ; A,, ii, 145.Ibid., 1913, 185ANALYTICAL CHEMISTRY. 183centration has been based on colour comparison with a standardsolution of hydrochloric acid and disodium hydrogen phosphate,both solutions being tinted with a suitable indicator.The authorsof the latter method also make the suggestion that the results ofthe test would be far less liable to vary if it were agreed to adoptas the standard solution one that was distinctly acid or alkaline,as small differences in the exact composition would then have lessinfluence.32 Another proposal is the substitution of sodium citratsfor ammonium citrate.33 The preparation of the solution thenpresents no difficulty, but the results do not always agree with thoseobtained by the use of ammonium ~ i t r a t e . 3 ~ Most of this work isAmerican, but continental workers have also contributed to theattempt t o place this test on a more satisfactory basis.35Three years ago some space was given to a consideration ofmethods of analysis of the new nitrogenous fertilisers, and anattempt made to reconcile the conflicting statements made concern-ing the estimation of cyanamide.36 A recent paper goes some wayin this direction, pointing out that Monnier’s results might be ex-plained by polymerisation of a portion of the cyanamide t o dicyano-diamide under his experimental conditions.Simple means aredescribed for combating this tendency to polymerisation, whethermaking use of Caro’s or of Kappen’s 36 method of analysis, and itis shown that, with this precaution, the two methods give identicalresults.37 The accurate estimation of total nitrogen in mixtures ofcalcium cyanamide and Norwegian nitre was found to present somedifficulty, methods which might’ have been expected t o be satisfac-tory all giving results below the truth.A simple and satisfactorymethod has now been described.38Water Analysis.The last two years have witnessed the appearance of an extra-ordinary number of papers dealing with the estimation of hard-ness in water, several of them inspired by the comparatively recentmethod of Blacher, others concerning themselves with the methodsdevised by Wartha and popularised by Pfeifer about twelve yearsago, whilst others either ignore the important work of these authorsor attempt t o discredit their methods by publishing records of32 D.Eastman aiid J. H. Hildebrand, J. Ind. Eng. Chem., 1914,6, 577; A . , ii, 675.33 A. W. Bosworth, ibid., 227 ; A . , ii, 289.1’. Rudnick, W. B. Derby, and W. L. Latshaw, ibid., 486 ; A . , ii, 576.35 T. Warynski and J. Langel, Ann. Chim. nnnl., 1914, 19, 1 ; A , , ii, 216.36 Ann. h’eport, 1911, 177.:%7 G. Grube and J. Kruger, Zeitsch. nnyew. Cham., 1911, 27, 326 ; A . , ii, 593.Y8 A. Stutzer, Chem. Zeit., 1914, 38, 597; A . , ii, 485184 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.experiments which will not stand examination. Wartha's methodswere originally described in a Hungarian journal, of which thepresent writer has never been able to discover the name; but theywere published in German by Pfeifer,39 and shortly after in Englishby Proctor,40 and have given excellent service in many hands duringthe last ten years.The method for permanent hardiiess dependedon the insolubility of calcium carbonate in the presence of excessof sodium carbonate, and that of magnesium hydroxide in thepresence of excess of sodium hydroxide. A volumetric method forestimating magnesia-necessary for calculating the chemicals re-quired for softening purposes-was also baseld on the insolubilityof magnesium hydroxide in presence of excess of calcium hydroxide.A dozen authors might be cited in support of these methods, but asingle reference to a recent paper will suffice, more especially asthat paper abounds in references and shows that the one authorwho seriously challenged the accuracy of the methold for estimatingpermanent hardness did not use the Wartha-Pfeifer method a t all,but a travesty of it, due to Lunge.41 The method of Blacher andhis co-workers for the estimation of temporary and permanent hard-ness dates back to 1907,42 but was not established on a firm basisuntil last year.I n its latest form i t depends on titration of thebicarbonate hardness with standard acid, using dimethylaminoazo-benzene as indicator, followed by titration of the total hardnesswith potassium palmitate, using phenolphthalein as indicator. A tfirst potassium stearate was used, but the preparation of the solu-tion was difficult; when made, its titre varied with temperature,owing to separation of solid soap; the end-point left much to bedesired, and, in the presence of complex saline mixtures, anomalousresults were obtained.These were found to be partly due to thepresence of palmitic acid as an impurity in the stearic acid. Purepotassium stearate gave more constant results, but the history ofthe method as a practical one dates from the adoption of purepotassium palmitate as reagent.43 Since then the method has beenreported on f avourably by several independent authors,44 includingJ. Pfeifer. Zeitsch. ccngcu*. Chem., 1902, 15, 193.4o H. R. Proctor, J. SOC. Chem. lnd., 1904, 23, 8.J. Zink and F. Hollandt, Zeitsch. angew. Chem., 1914, 27, 235 ; A . , ii, 490.-12 C. Blaclier, Rignsche Indwtrie Zeit., 1907, 305 ; C. Blacher and J. Jacoby,Chm. Zeit., 1908, 32, 744; A . , 1908, ii, 897 ; C.Blacher, U. Korber, and J.Jacoby, Zeitsch. angezu. Chmn., 1909, 22, 967.C. Blacher, P. Griinberg, and M. Kissa, Chem. Zeit., 1913, 37, 56 ; A . , 1913,ii, 153.41 J. Zink and F. Hollandt, Zeitsch. angew. Chem., 1914, 27, 437 ; A . , ii, 670 ;E. Nockmann, Pharm. Zenlr-h., 1914, 55, 435 ; A., ii, 490 ; W. Pflanz, N d t . Kgl.Lundesanst. f. Wmserhyg. zu. Berlin-Dahlem, 1913, 17, 141 ; A., 1913, ii,1073ANALYTICAL CHEMISTRY. 185L. W. Winkler, who prefers it t o his own method, and makes theuseful suggestion that the use of dimethylaminoazobenzene, whichis sensitive to carbon dioxide, is best dispensed with, and that thetemporary hardness should be estimated by Hehner’s originalmethod, using methyl-orange, which is destroyed by means ofbromine before proceeding to the titration with potassium palmitateand phenolphthalein.The same author describes an improvementof his method for the estimation of hardness due to lime, depend-ing on titration with potassium oleate, as in Clark’s process, usingan alkaline tartrate solution to prevent co-precipitation of mag-nesia.45 The latter method may prove useful to those who, likeone recent author,46 find difficulty with Wartha’s method for mag-nesia. The writer has instructed many persons in the lattermethod, all of them acquiring skill in it with ease, and he prefersto estimate magnesia--usually present in least amount-directly,and lime by difference, but the paper referred t o cannot be ignored.The use of soap solutions, used in Clark’s manner, has tended tofall into abeyance ever since Hehner published his methods for theestimation of hardness, and still more rapidly since Pfeifer pub-lished Wartha’s method for estimating permanent hardness, whichwas a great advance on that of Hehner.However, the recent dis-covery that solutions of potassium myristate, unlike solutions ofsodium oleate o r of Castile soap, behave similarly towards equiva-lent solutions of calcium and magnesium, may leald to a revival ofClark‘sFor the estimation of dissolved oxygen in water, Romijn’s modifi-cation of Winkler’s method is in every respect more convenientthan the original method, but there are cases where its use maygive rise t o erroneous results, for example, with sea-water.48 I nthese cases, the use of Rochelle salt t o inhibit the formation of aprecipitate must be abandoned.This involves the abandonment ofRomijn’s pipette with its manifest advantages. Attention may,therefore, be directed to a new form of pipette for use accordingto Winkler’s original method, but which, like Romijn’s pipette,makes it possible to take samples from wells a t definite depths orfrom springs difficult of access, excludes any possibility of errordue to atmospheric oxygen, and is convenient to handle.49Whilst Winkler’s method leaves little t o be desired on the scoreof accuracy, and has been made simpler in execution by the designof apparatus such as that just referred to, circumstances frequently45 L. W. Winkler, Zeitsch. anal. Chem, 1914, 53, 409 ; A ., ii, 578.46 C. Bahlmann, J. I7d. E?ty. Ch.m., 1914, 6, 209 ; A . , ii, 294,47 Miss H. Masters and H. L. Smith, T., 1913, 103, 992.‘8 W. P. Jorissen, Zeitsch,. anal. Chem., 1910, 49, 424 ; d., 1910, ii, 749.J. J. van Eck, ibid., 1913, 52, 753186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.arise where the convenience of a simpler test, that could be com-pleted in the field in a few minutes, would outweigh some smallloss of accuracy. The number of simple methods that have beendescribed, some of them too rough t o merit consideration, areevidence of a widespread desire for a more satisfactory field method,and attention may therefore be directed to a recent adaptation tofield conditions of a method originally due t o Linossier, who usedphenosafranine as an indicator for ferrous iron in the presence OFalkaline tartrate.The field modification of the method is empirical,but in competent hands yields very satisfactory results.50 Therecommendation of the Royal Commission on Sewage Disposal,1898, that a general statutory standard f o r effluents can properlybe fixed, itself a highly controversial proposition, could find nonotice in a report on analytical chemistry if it stood alone, butwhen the Commissioners in their Eighth Report proceed to formu-late a test--the amount of dissolved oxygen taken up from tap-water during five days' incubation-which is unnecessarily trouble-some, likely to yield discordant results, and renders useless theanalytical data hitherto accumulated, attention must be directedto the test and t o the controversy it has aroused.51E. B. Phelps suggested the use of an acid solution of o-tolidinef o r the detection of such small quantities of free chlorine as maybe present in drinking water which has been treated with hypo-chlorite. It was recently stated that the method was not adaptedt o quantitative work,52 but' a slight modification of the originalmethod is now sho'wn to be incomparably the best available for theestimation of quantities of the order of 1 part per million or less.53Less than onehundredth of this amount may be detected by itsmeans, and for some practical purposes its sensitiveness is toogreat, the comparative bluntness of the starch-iodide reactionhaving proved to be an actual advantage in devising field methodsfor use by thQse engaged in the testing and sterilisation of drink-ing water for our troops on the Continent.A recent paper on the estimation of small quantities of lithiumin the presence of large quantities of the salts of other metalsproperly falls into this section. The method substitutes isobutylalcohol for amyl alcohol as a means of separating lithium chloridefrom the chlorides of sodium and potassium. The latter salts aremuch less soluble in isobutyl alcohol than in amyl alcohol, whichis, moreover, objectionable t o use. Attention is directed t o the50 J. Miller, J. 8oc. Chew. Ind., 1914, 33, 185; A., ii, 380.51 H. T. Calvert, ibid., 1913, 32, 265.52 Dittoe and Van Buskirk, Ohio State Board of Health, 1913, Bn11, 3.53 J. W. Ellmsand S. J. Hauser, J. h i d . Eng. Chcm., 1913, 5, 914; 1914, 6,553: A., ii, 66, 669ANALYTICAL CHEMISTRY. 187fact that, in the course of a water analysis, lithium will usuallybe underestimated if calcium salts are eliminated in the usualmanner, and special methods are described for avoiding such lossof lithium.64A t intervals during the last twenty years efforts have been madeto agree on a uniform manner of reporting results of wateranalysis, efforts in which American chemists have been alwaysprominent. Hitherto little has been accomplished, but it is to behoped that the latest effort of a joint committee of the AmericanChemical Society, the American Public Health Association, andthe Association of Official Agricultural Chemists will be moresuccessful, and lead to similar agreement being reached here. Arecent paper discusses the confusion that exists, and advocatesreporting the constituents in ionic form.55 Some at least of thearguments raised against this proposal when i t was first made haveceased to have weight.G. CECIL JONES.54 L. W. Winkler, Zeitsch. anal. Chem., 1913, 52, 628; A . , 1913, ii, 877.55 R. B. Dole, J. Ind. Eng. Chem., 1914, 6, 710; A . , ii, 77

ISSN:0365-6217    

DOI:10.1039/AR9141100161

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.ALTHOUGH the source which usually supplies the bulk of papersdealing with biochemical subjects was cut off when the year hadrun but little more than half its course, I have not found muchrelief from the embarrassment with which a plethora of materialovertakes the writer of an annual Report. I do not think that it canbe fairly said of the contemporary output of work in biochemistry,as is sometimes said by the cynic of the general average scientificoutput, that a considerable proportion of it can be with advantageneglected. I find, on the whole, very few papers which i t is apleasure to ignore. It is, however, impossible not to feel, just nowa t any rate, how greatly current American work stands out insignificance and importance. The subject has taken firm root onthe other side of the Atlantic.It has been appreciated there, andgiven good equipment. Although a few of the more distinguishedworkers have been imported, active and successful local schools aremaking themselves greatly felt. Meanwhile, our own output isincreasing satisfactorily, and if one surveys the literature of theyear with a mind as little as possible biassed, one really feels thatmost of those papers which, having read, one wishes to discuss, arejust now written in the English language. This applies, it is true,more particularly t o the subject of metabolism, but it is studiesdealing with metabolism, those concerned with what happens inthe animal itself, that mainly justify the specialisation of physio-logical chemistry.I n the case of t h e e Reports, the pure chemistryof physiological substances is naturally often dealt with under thehead of Organic Chemistry, whilst the technical methods of thebiochemical laboratory receive a t least some attention as part ofAnalytical chemistry. The chemistry of metabolic processes maytherefore legitimately occupy a large part of the more specialisedsummary. I shall begin this year, however, with a subject which,whilst abstracted under Organic Chemistry, is of special interest tothe physical chemist, and perhaps better to be criticised by him. Itis, nevertheless, the very legitimate concern of the physiologist.18PHYSIOLOGICAL CHEMl STRY. 189Catalysis b y Enzymes.Enzyme studies, perhaps as the result of divided responsibility,have been somewhat neglected in these Reports.It would bedifficult to give here even the briefest account of the literaturethat has accumulated since the last reference to the subject; butprogress in actual fundamentals is reported in comparatively fewpapers, and it may be claimed that a large proportion of these isof English or American origin. The significance of this year’swork cannot be brought out without a brief discussion of somepapers which appeared last year. A communication by W. M.Baylissl dealing with the influence of emulsin on the equilibriumin aqueous solutions of glycerol and dextrose seems especially note-worthy, since the experimental results described remove all f ounda-tion for certain statements in the literature which have greatlycomplicated the whole subject of catalysis by ferments.Particu-larly important is Bayliss’ destructive criticism of the statementthat certain reversible reactions require distinct enzymes for cata-lysis in opposite directions; in other words, that in certain casesenzymes that synthesis0 have to be distinguished from those whichcontrol decomposition. This is a conception which, if it had asound experimental basis, would clearly remove enzymes from thecategory of ordinary catalysts. Bayliss shows, further, that, t ojudge, a t any rate, from the case studied by him, an enzyme, whencontrolling the synthesis of optically active substances, leads to theproduction of that isomeride which it also decomposes, and not, ashas been stated, of its optical antipode.He finds, in fact, thatreactions in the system studied follow in all respects the lawsdeduced from mass-action for equilibrium in a reversible systemcatalysed by a single enzyme. Closely related to the work ofBayliss is that of E. Bourquelot and his colleagues, who have pub-lished during the year many papers dealing with the synthesis ofa- and @-glucosides under the influence of appropriate enzymes.The ease with which these biological syntheses are obt-ained isremarkable. Glucosides were prepared from methy1,Z ethyl,propyl,3 and anisyl4 alcohols; also from glycol, glycero1,b and ?n-and pxylene glycols.6 Methyl 7 and ethyl galactosides 3 wereJ. Physiol, 1913, 46, 236; A . , 1913, i, 919.J.Pharm. Chim., 1914, [vii], 9, 19; A . , i, 144,Compt. rend., 1914, 158, 70; A . , i, 144.Ibid., 1377 ; A , , i, 706.lbid., 1913, 157, 1024 ; A , , i, 72.Ibid., 1914, 159, 213 ; A., i, 1080.Ibid., 158, 204 ; A., i, 253.* J. Pharm. Chim., 1914, [vii], 9, 327 ; A , , i, 498190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.obtained under the influence of an enzyme from bottom yeast.Bourquelot and M. Bride19 have studied the equilibrium in asystem containing alcohol and dextrose, together with a- andP-glucosidases. The a-ferment induces equilibrium when the ratioof combined and free dextrose is 32.6 to 67.4, whilst with the&ferment the ratio is 23.39 t o 76.61. The authors find that eachenzyme is quite without action on the glucoside synthesised bythe other, and if both are present the equilibrium proper to eachis arrived a t independently. The French authors l o fully confirm,therefore, the observations of Bayliss.H. E.and E. F. Armstrong11 have published, in a most interest-ing paper, their views concerning the nature of enzymes andenzyme action as based mainly on the results of the long seriesof experimental researches which they and their co-workers havecontributed to the subject'. They conclude, as others, and par-ticularly Bayliss, have done, that enzymic action takes placeentirely a t the surface of colloid particles suspended in the solutionof the substrata, and not between substances which are all in truesolution. They hold that a hydroclastic enzyme has itself a doublefunction, namely, that of attracting o r holding the hydrolyte andthat of determining hydrolysis.It is a composite agent in whichthe functions of a catalyst, such as platinum-black, are combinedwith those of an acid catalyst. It differs, however, from anordinary catalyst in displaying a specific and limited activity.Using a nomenclature somewhat akin to' that of Ehrlich, theyspeak of the enzyme as containing an acceptor, together with anagent. Views as to the possible nature of the acceptor and actorgroups in special cases are developed by the authors on character-istically objective lines. With regard to the dynamics of enzyme-controlled reactions, the authors hold that their own experimentsconfirm the statement, first made by Duclaux in 1898, and sub-sequently in 1902 by Adrian Brown, and also by Horace Brownand Glendinning, that in each successive interval of time theenzyme determines the hydrolysis of the same amount of substrate.The velocity is thus a linear function of the time, and this relationis held by the Armstrongs to be fundamental, any departure from itbeing due to the influence of the products of change.The exist-ence of this relation, coupled with the fact that after a certainmaximum has been reached increase in the concentration of thehydrolyte diminishes the activity of the enzyme, is held by theauthors to show that the laws of mawaction do not apply tolo See for R general discussion of the results obtained, J. Phnrm. Chim., 1914,l1 Proc.Roy. Soc., 1913, [B], 86, 561 ;A, i, 1116.Comnpt. rend., 1914, 158, 370; A., i, 341.[vii], 9, 603 ; A., i, 1147PHYSIOLOGICAL CHEMISTRY. 191enzyme reactions. “ I n no particular,” they write, “is the change‘ a mass-action effect,’ nor are the departures such that it can besupposed that the change is primarily ‘ unimolecular,’ and sub-sequently varied owing to the occurrence of secondarychanges. . . .”In this view they differ, of course, from most writers who, whilstrecognising that the above-mentioned linear time-function is to befrequently observed, consider it as representing only a part of thecomplete mass-action velocity-curve. It corresponds with certaindefinite and limited relations between enzyme, substrate, and pro-ducts in solution.It is true that velocity-curves obtained experi-mentally have hitherto been fitted by equations derived from con-siderations of mass-action only by introducing purely empiricalconstants, but in what is perhaps the most important contributionto our knowledge of enzymecatalysis published during the presentyear, D. D. Van Slyke and G. E. Cullen12 have supplied a mass-action equation covering very exact,ly the experimental data, andcontaining no arbitrary constants whatever. The theoretical con-siderations presented in this paper are based upon an experimentalstudy of t4he enzyme urease obtained from the soja bean. Theinterest that attaches to this enzyme is clear. It hydrolyses a verysimple, neutral, and symmetrical molecule t o products of markedchemical activity.It is absolutely specific in relation t o its sub-strate, and controls a reaction of great physiological importance.Its significance has long be’en recognised by H. E. Armstrong, andas soon as its presence in the soya bean (itself a circumstance ofinterat) had been demonstrated, in 1909, by Takeuchi, he pro-ceeded to its study and, in conjunction with various co-workers,had established many interesting facts concerning it before theappearance of Van Slyke and Cullen’s publications.For the moment, however, I am concerned with the mass-actionformula presented by the latter aut’hors. The form of their equa-tion is based upon the assumption that in a reaction catalysed byan enzyme there are two phases with diff emrent velocity-constants,namely, one concerned with the rate of combination of enzyme andsubstrate, and the other with the rate of the subsequent decomposi-tion. This idea, and the view that it explains why the usual mass-action formula does not hold in zymolysis, were clearly expressedtwelve years ago, by Adrian Brown.Van Slyke and Cullen, how-ever, justly claim that the whole course of the dual reaction hasnot hitherto been formulated on these lines in such a way that theassumptions made could be fully tested experimentally.l2 J. Biol. Chem., 1914, 19, 181 ; A . , i, 1181192 ANNUAL REPOR 8 ON THE PROGRESS OF CHEMISTRP.Van Slyke's and Cullen'a equation takes the formt + "> d/ h - \ - Time for decomposi- Portion of time consumed Portion of time con-tion of 2 amount of in uniting enzyme and sumed by enzymesubstrate. substrate.in decomposingsubstrate.a represents the amount of substrate (carbamide) present per unitvolume a t the beginning of the reaction, x the amount decomposeda t time t, E the enzyme concentration, c the velocity of combina-tion of enzyme and substrate, and d the velocity a t which thecombination splits. It is Seen that the ordinary mass-actionis'only amplified by the addition of a term l a formula, t = -1ou- K ra -x'representing the velocity of the second phase of the dual reaction,but with the rmult that the equation fits the experimental datawith most remarkable accuracy. What is especially important isthe circumstance that the two constants involved, c and d, are notarbitrary, but can each be determined experimentally by sufficientlyvarying the relative velocity of the two distinct phases of the dualreaction. When the concentration of the hydrolyte is sufficientlyhigh (between 0.08 and 10 per cent.of carbamide), even widevariations in the concentration have no effect whatever on thevelocity of the reaction, a fact which experiment establishes abso-lutely. This means that, once such a concentration of substrateis reached, the time spent in uniting enzyme and substrate is1 ac a - xnegligible. The term -log-, then disappears from the equa-tion, and the value of d can therefore be directly determined. Onthe other hand, within a range of low concentrations of the hydro-lyte, and also under certain other conditions, the ratio c/d becomesrelatively small, the time consumed by the first phase of thereaction becomes measurable, and now varies with the concentra-tion of the hydrolyte.Under these conditions, the value of dbeing known, c can be determined. The experimental data agreeso exactly with the calculated values that the assumptions under-lying the formula seem to be justified. We have, therefore, anexact expression for the course of an enzyme reaction derived fromconsiderations of mass-action, and also important evidence in favourof its dual nature. Although these results are based upon thestudy of urease alone, the authors claim, from a study of theavailable data, that they may be applied to many other ferment-reactions, and probably have a general bearingPHYSIOLOGICAL CHEMISTRY.193It is interesting t o compare Van Slyke’s discussion of his resultswith the expression by the Armstrongs13 of the view that the lawsof mass-action do not apply to enzymes, although the difference isperhaps one ?f point of view only. When a catalyst forms atemporary compound with the substrate, when that compound isformed with a velocity which is great compared with that of thesubsequent decomposition, and when the number of molecules coin-bined with the catalyst (and these alone suffer change) is smallcompared with the whole number in solution, i t is clear that theenzyme-substrate system must remain practically constant inamount, and the rate of decomposition will, so long as the aboveconditions obtain, be a linear function of the time.We oughtnot, from any point of view, to expect the ordinary time relationsof either a unimolecular or a bimolecular reaction. Only if thelinear relations held under all conditions of concentration shouldwe be entitled t o wonder what had become of the influence of mass-action. Van Slyke and Cullen’s results indicate with exceptionalclearness that this is by no means the case, and would seem tojustify those who prefer to believe that the normal effects of mass-action, if exerted under somewhat special conditions, are no morein abeyance in enzymereactions than elsewhere in chemistry. Itshould bO understood, however, that Van Slyke’s clear-cut resultsand simple formula are obtained only when the influence of thedecomposition products is eliminated, a condition that may beeasily secured in the case of urease (see below).The work of VanSlyke and Cullen, being directed to other ends, doea not takeaccount of the reaction as a balanced reaction, and fails t o dealwith the question of synthesis as i t may occur under the controlof the catalyst. The Armstrongs have always given particularattention t o the influence of the products of change in their fer-ment studies. H. E. Armstrong, M. S. Benjamin, and E. Rorton14have fully investigated their effects in the case of urease, and havebrought out, among many other facts, the exceedingly interestingone that the two products of the decomposition of carbamide,namely, ammonia and carbon dioxide, show opposite effects on thecourse of the reaction, ammonia greatly retarding it, whilst carbondioxide accelerates it to an equally remarkable extent.Sinceammonium carbonate also retards, although to a less degree thanammonia, the action of urease on carbamide is self-inhibitory.Van Slyke and Cullen wholly eliminate this effect by the use ofprimary and secondary phosphate mixtures, so adjusted that thehydrion-concentration is maintained near the optimum throughoutthe course of the reaction. I n a second paper, Van Slyke, now inLOG. cit. 14 Proc. Roy. Soc., 1913, [ B ] , 86, 328 ; A . , 1913, i, 781.REP.-VOL. XI. 194 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.conjunction with G. Zacharias, gives a striking account of theinfluence of hydrion-concentration on ths activity of urease.Changes in this have absolutely different and independent effectson the two successive phases of the dual reaction.The combiningvelocity, represented by c in Van Slyke and Cullen’s equation,varies in inverse ratio to: the hydrion-concentration, whilst thevelocity of decomposition (d in the equation) is greatest a t theneutral point, and is retarded by eit,her alkalinity or acidity.Apparently ammonium carbonate inhibits because of its alkalinity,and not specifically, but one feels that the possibility of a synthesisof carbamide from this product of ita decomposition under theinfluence of the enzyme is not negatived by this fact.An important point in Van Slyke and Cullen’s work which Ihave not yet touched upon is the proof, also given by E.K.Marshal1,lb and less fully by Armstrong, that the velocity of theurease reaction is directly and in a linear sense proportional tothe enzyme-concentration, and this throughout a wide range. I nmany cases of enzyme-action the proportionality is said to be notlinear, but of a kind that suggests the formation of adsorptioncompounds between ferment and substrate as a preliminary tot theestablishment of chemical relations. I n the case of urease thereis no suggestion of ratios of this sort. The sharply defined maximalamount of carbamide which a given amount of enzyme can hydro-lyse per unit time, and the fact that the velocity of hydrolysis is soexactly proportional to the concentration of the enzyme, indicate,in Van Slyke’s opinion, the existence of definite combining propor-tions between catalyst and substrate, and point to more purelychemical relations.We have often, from time to time, been pre-sented with velocity-curves and constants for enzyme-reactions byworkers who have taken but little account of the complexity of con-ditions. Factors of an accidental, or even of an artificial, characterhave been allowed to intrude into the results. Such results haveonly been the more misleading because they have received a false andpretentious stamp of accuracy by being prwented in mathematicalform. The study of enzyme-dynamics, however, seems now t o havefound itself. Results of real accuracy and significance are beingobtained which are important t o chemists and biologists alike.Dynamical studies alone, however, will probably fail to tell us allwe want t o know about ferments.As the Armstrongs very trulyremark, in the paper already quoted, it will be difficult to arrivea t any final definition of enzymes until their specific nature hasbeen deciphered. We are not a t all justified in believing thatendeavours to isolate ferments in a pure state, or a t any rate inl5 J. Biol. Chem., 1914, 17,.351 ; A., i, 606PHYSIOLOGICAL CHEMISTRY. 195such a form as to offer evidence of constitution, must necessarilyfail, but a t present we have to be content with speculations.L. Michaelis,l6 i t is true, has advanced the view that ferments aresubstances that undergo electrolytic dissociation in solution, andthat the active agent may in one case be the undissociated mole-cule, and in others the cations or anions respectively. Thus,invertase is an acid of which the undissociated molecules are aloneactive.Erepsin and lipase are acids which are active only in theform of their anions, whilst pepsin acts proteolytically in the formof cations. These conceptions are founded chiefly upon observa-tions dealing with the effect of varying hydrion-concentrations onthe activity of the enzymes, and on the direction of their migra-tion when submitted to a potential gradient, The facts areinteresting; but i t is doubtful if the experimental evidence canbear the weight of the conclusions, and, in any case, it does notthrow much light upon the actual cheniical nature of enzymes.The Armstrongs postulate that the relation of the “acceptorsection” of the enzyme to the hydrolyte is not that of key andlock in Emil Fischer’s sense, “but that of a superposable, andtherefore identical, radicle.” The “ agent ” section which promoteshydrolysis is possibly a carboxyl group acting under exceptionallyfavourable conditions.These views are suggestive, but they re-main, of course, purely speculative. Investigations such as thoseof J. M. Nelson and S. Born 17 into the “ constitution ” of invertasewill scarcely be accepted as having arrived a t a demonstration ofthe nature of a ferment, and I imagine that few a t present willfind much sympathy with the view of Barendreclit18 that “ a nenzyme particle contains the same molecule [as that] which isliberated or acted upon by this enzyme, in some active state,” theactivity spreading through the solution of substrate as a radiation.If ever we arrive at a knowledge of the chemical constitution ofenzymes, we shall learn a great deal more than we now know aboutthe constitution of the living cell.The view that zymolysis depends upon the preliminary f ormatioiiof a compound between substrate and catalyst underlies much ofthe work of L.Michaelis. To this belief, indeed, all authors arecoming, and the conception of ‘‘ contact ” catalysis is disappearingfrom the field of enzyme chemistry. Michaelis and his co-workershave been studying the action of substances which inhibit zymo-lysis. It is assumed that inhibitors can act in one of two ways:16 Biochem.Zeitsch., 1913, 49, 333 ; A., 1913, i, 540 ; ibid., 7914, 60, 43 ; A . , i,l7 J. Amer. Chem. Soc., 1914, 36, 393 ; A . , i, 339.18 Biochem. J., 1913, 7, 549 ; A., i, 214.443 ; ,ibid., 1914, 65, 1 ; A., i, 1007.0 196: ANNUAL REPORTS ON THE YROGRESS OF CHEMISTRY.they can either ( a ) combine with the ferment, or ( b ) diminish therate of decomposition of the substrate-ferment compound.L. Michaelis and P. Rona’o have developed in theory and prac-tice a method for determining which of these alternatives may holdin a given case, and find, to take one instance, that, in the case ofyeast-maltase, sodium chloride, sodium nitrate, and glycerol actby diminishing the reaction-velocity, whilst lithium chloride anddextrose act by combining with the ferment.It may be noted, inparenthesis, that Van Slyke and Zacharias, in the paper alreadyquoted, give theoretical consideration to a similar distinctionbetween inhibitors. They suggest modifications in their funda-mental equation which take account of each type respectively.Returning once more to the work of Michaelis, a paper withH. Pechstein on the pytalin of sa1iva2O must be mentioned inillustration of another side of the subject. It is well known thatthe diastatic effect of saliva and pancreatic juice is not exerted inthe absence of electrolyt’es. The effect of salts on the activity ofthe former was first studied on modern lines by S. W. Cole,21 whoattributed the accelerative effects to the anions.It is greatest, hethought, in the case of the salts of strong acids and least in those ofweak acids. Michaelis and Pechstein now come t o the conclusionthat the diastase forms definite complexes with the anions, and i t isthese complexes, and these alone, that exert the disastatic action.The affinity of the ferment for the anion varies, being very great,for example, for NO3’, not much less for C1’ and Br’, and verysmall for SO,’, and acetate and phosphate ions. The relativeactivity of the different compounds varies greatly, the chloridebeing the most powerful, and the nitrate much less so, whilst verymuch less active are the sulphate, acetate, and phosphate com-pounds. The optimum hydrion-concentration is different andcharacteristic for each salt complex.It would appear that otherinterpretations of the experimental facts dealt with by Michaelisare possible.Many interesting papers dealing with the special properties ofindividual ferments mwt perforce be left without reference. Iwill close this section by calling attention to a case of catalysis byorganic agents which has an interest of its own, although it takesus away from the region of exact studies such as those with whichI have been dealing. Several years ago the researches of thePavlov school brought to light the fact that the proteolytic fermentof the pancreatic juice is secreted in the form of an inactive pre-cursor, trypsinogen, and that this is converted into active trypsinBiochesn.Zeitsch., 1914, 60, 62, 795 ; A., i, 444, 445.J. P?~ysiol., 1903, 30, 202 ; A., 1904, i, 131.2o Bid., 1914, 59, 77; A . , i, 340PHYSIOLOGICAL CHEMISTRY, 197by a catalyst contained in the intestinal juice, and known asenterokinase. The velocity of this activation has been studiedrecently by H. M. Vernon,22 and also by J. Medlanby and V. J.W00lley.23 I n each of these researches the fact came to light thatthe velocity of the process undergoes a positive acceleration, and,towards the end of its course, is enormously increased. Thus,in one experiment, Mellanby and Woolley found that whilst 125units of active trypsin were produced in the first ninety minutes,after an additional twenty minutes the solution contained 750units.Vernon,24 in his latest paper, states that the rate ofacceleration during the last half of the process may be a thousandtimes more rapid than the initial rate. The phenomenon suggestsautocatalysis, and Vernon at one time believed that trypsin, onceliberated by enterokinase, is itself capable of activating trypsinogen,so that a species of autocatalysis becomes established. Mellanbyand Woolley, however, bring evidence against this view, and, more-over, the velocity-curves obtained do not show the S-shaped formof ordinary autocatalysis-curves, but indicate rather a, continuedacceleration of the reaction right up to the point of its completion.Vernon’s latest research leads him to the conclusion that “thetrypsin liberated in the earlier stages of the reaction by the directaction of enterokinase gradually sets free an enzyme (calleddeuterase, to indicate that it acts secondarily t o enterokinase)from a precursor, and that the deuterase is mainly responsible forthe later stages of the activation process.’’ The temperature-coefficient of the deuterase-effect is lower than that of the entero-kinase-eff ect, and the later stages of trypsin-activation have a lowercoefficient than the earlier.Deuterase, once formed, exhibits linearo r logarithmic relations, like other ferments, but the rate of itsown liberation as i t occurs in mixed pancreatic and intestinalsecretions increases in geometrical progression. If no simpler ex-planation for the facts is forthcoming, this is certainly a remark-able case of physiological catalysis.The Specificity of Tissue-enzymes.We have long, of course, had t o recognise that chemical differ-entiation underlies morphological differentiation ; that the blood-and tissue-prpteins of one animal are, for instance, chemicallydifferent from those of another; and that within the same animalthe proteins of any one tissue are no less distinct from those ofany other.Observations made during the last year or two indicate22 J. Physiol., 1913, 47, 325 ; A., i, 214.23 B i d . , 1912, 45, 370 ; A., 1913, i, 113.z4 Biochem. J., 1914, 8, 494 ; A., i, 1205198 ANNUAL REPOHTS ON THE PROGRESS OF CHEMISTRY.that an equal specificity appertains t o the proteolytic enzymes ofindividual living tissues.E.Abderhalden began, so far back as 1906,25 to test this questionby submitting various synthetic polypeptides to the action oforganic extracts, and in succeeding years he published many papersshowing that there were marked differences to be observed in thepeptolytic powers of the various tissues-diff erences related to thestructure and configuration of the polypeptides submitted t o theiraction. Recently he has demonstrated the still more significantfa.& that the enzymes of a given tissue, whilst they can alwayshydrolyse peptones made from the proteins of the same tissue, mayfail altogether to act on peptones made from the proteins of othertissues. It was foreshadowed insome of the earliest work on autolysis; but Abderhalden has shownthat, by testing the action of the enzgnies on peptones made fromthe native proteins rat,lier than on the latter themselves, the factsbecome technically more easy to demonstrate.Observations onthese lines begun by him last year26 have now been extended, andin conjunction with G. Ewald, Ishiguro, and R. Watanabe’7 he haspublished experiments showing, for example, that extracts fromthe liver decompose peptones prepared from that organ, but nottKose prepared by similar processes from lungs, brain, kidney, orpancreas. A lung extract hydrolyses lung peptones, but not pre-parations from muscle, liver, o r kidney. All observations seem t oshow that for some reason the renal enzymes have a more generalaction. One must admit that the technique used to demonstratethese facts is evidently exceedingly difficult, and a repetition ofthe observations will not be lightly undertaken by ot.hers.I f ,however, relying upon the reputation and experience of Abder-halden, we accept them, they are certainly important and sug-gestive. The appearance of a highly specific enzyme in the cell,where alone the related and highly specific substrate is to be found,and its appearance in that cell only, are facts which bear, i t seemsto me, with some significance upon the nature and origin of theenzyme itself. It is important in connexion with what follows torecoguise that, according to Abderhalden, the blood does not9normally contain ferments which can act on tissue proteins.L. Pincussohn,Z* i t is true, in a paper published a year ago, claimedto have found in normal dogs’ blood a ferment capable of actingon peptone prepared from dogs’ muscle, although i t had no actionon similar peptones prepared in the same way from cats’ muscle,25 Zeitsch.physiol. Chem., 1906, 47, 466 ; A., 1906, ii, 464.26 B i d . : 1913, 87, 220 ; A , 1913, i, 1118.27 Ibid., 1914, 91, 96 ; A . , i, 900.28 Biockem. Zeitsch., 1913, 51, 107 ; A., 1913, i, 788.The point is not altogether newPHYSIOLOGICAL CHEMISTRY. 199or on other peptones from foreign substances. Abderhalden andG. Ewald,29 however, could not, in repeated experiments, obtainfrom normal blood any ferment capable of splitting tissue-peptones,and they claim to have had the remarkable experience of findingthat whenever the blood contained a ferment active with theproteins of some particular organ, such activity being observedseventeen times in thO course of 1000 examinations, an unsuspectedlesion of that organ always proved to be present.The discoveryof such fermentts in the blood becomes, therefore, of diagnosticimportance. This leads to the discussion of related phenomena.Defensive Ferments.We are still concerned with the work of the indefatigable in-vestigator Abderhalden. His claim t o the discovery that the entryof a foreign protein, of a disaccharide, or of a foreign fat, into thecirculation of an animal promptly leads t o the appearance in theblood of a specific ferment, not there before, capable of hydro-lysing the foreign substance, has, chiefly perhaps because of a par-ticular case with practical bearings, to which I shall referimmediately, led to no small excitement in clinical laboratorieseverywhere.Abderhalden quickly put the results of his earlierexperiments, together with his views about their significance, intoa book. The first edition of this appeared in 1912, so that thesubject is not exactly a new one, but it has hitherto received nonotice in these Reports. Ih importance, real or supposed, calls forsome reference. The current year has seen the appearance of afourth edition of the book,30 as well as many fresh papers dealingwith the subject.When proteins are injected into the vein of an animal, reachingthe circulation parentally and escaping the digestive mechanism,the blood itself rapidly develops a proteolytic power which it didnot possess before.The specificity of the enzyme or enzymes thuscalled forth, however, is not marked; the circulation of any foreignprotein causes the development of a more or less general proteo-lytic activity in the blood. Very different is the case (according t oAbderhalden) when the protein enters in special circumstances.The pregnant woman carries within her in the form, not ofthe fetus, but of the placenta, a source of proteins which areforeign to her own body. As soon as the placenta has formed, itsproteins enter the blood-stream, and the formation of a highlyspecific “defensive” enzyme is the response. The blood of thepregnant woman, and her blood alone, can digest placenta,-29 Zeitseh.p h p i o l . Chem., 1914, 91, 86 ; A . , i, 896.30 L‘ Abwehrfermente der tierischen Organismus,” 4th Auflage, 1914200 ANNUAL REPOR1‘S ON THE PROGRESS OF CHEMISTRY.proteins. No other form of tumour and no pathological conditioiisof any kind lead t o the production of this specific ferment. Thisis the particular instance of a defensive ferment t o which I referredas having caused a flutter in the clinical world. After the pheno-menon had been described, Abderhalden’s laboratory becamecrowded with ud hoe medical inquirers, all anxious to learn an easymethod of getting early information about the coming generation.Why the specificity of the ferment produced should be so muchgreater than when foreign proteins are injected is not quite clear.Artificial protein preparations seldom, of course, represent pureindividual substances, and the method of injection is more brutaland sudden, and likely, therefore, t o produce some more generalresponse than when, as in the case of the placenta-proteins,material gradually enters the blood.I have not space t o deal fullywith the technique of this work. Probably, as this reference to itis somewhat belated, i t is already more or less familiar to most.Delicate methods of detecting the digestion of the prot,eins arerequired. Either an optical method is used, or the protein (forexample, placenta-peptone) is placed, together with a sample of theblood serum, in a small dialyser.I f digestion occurs, and only then, amino-acids are to be detectedin the dialysate.For this detection, the very de1icat.e colourreaction with Ruhemann’s triketohydrindene hydrate 31 is used,this substance having been put on the market under the suggestivename of I ‘ ninhydrin.”Even more interesting, from some points of view a t least, thanthe response to foreign proteins, is the circumstance that thesimpler molecules of a disaccharide can call forth a similardefensive enzyme. Our knowledge as t o this fact is really by nomeans new, for, in 1905, E. Weinland32 showed that whilst theblood of young dogs is free from invertase, the enzyme appears ini t as the result of injections of sucrose. The significance of thisobservation was not, perhaps, sufficiently appreciated a t the time.Five years later similar observations were made in Abderhalden’slaboratory with respect to sucrose and lactose.T. Kumagai33 haspublished a long paper on the subject in which, in addition toconfirming the earlier work, he makes the statement that injectionof the monosaccharides Izvulose and galactose can call forthinvertase. This, Abderhalden and E. Bassani34 are unable t o con-firm. With regard to the influence of sucrose, i t seems that, onthe whole, the response can be got with more certainty from31 T., 1910, 97, 2025.32 Zeitsch. Biol., 1905, 47, 279 ; A . , 1905, ii, 730.Biochem. Zeitsch., 1914, 57, 380 ; A . , i, 112.34 Zeitsch. phylsiol. Chem., 1914, 90, 369 ; A., i, 765PHYSIOLOGICAL CHEMISTRY. 201rabbits than from dogs.35 Kumagai, in the paper mentioned,claimed that an independent and altogether remarkable property isacquired by the blood-serum as a result of the injection of sucrose.It is said then to act on de’xtrose and lxvulose, first converting theformer into the latter, which next suffers synthesis into a disac-charide. The observations were made in F.Rohmann’s laboratorya t Breslau. A later paper Fublished by Rohmann and EurnagaiS6con jointly, contains the supposed proof that the disaccharide islactose. That the injection of sucrose should call into the blood acatalyst capable of converting, outside the body, dextrose intolactose is a truly extraordinary event. The evidence as describedis conclusive enough, but one cannot but feel scepticism, and it isto be hoped that the experiments will be repeated.If the facts areas stated, they are of great physiological importance.It seems to be, a t any rate, of quite exceptional interest to knowthat an immunity reaction as represented by the productiond e ILOVO of a more or less specific hydrolytic ferment may be calledout by simple molecules such as tlhose of the disaccharides. I nconnexion with the immunity-phenomena of disease we are too muchaccustomed to think of the colloid nature of toxins as playing someessential part.How precisely the ferments under discussion are to be related tothe factors of immunity as recognised in other connexions is notyet clear. A. Hauptmann37 and others suggest that the defensiveferments, like other anti-substances, are probably constructed onaniboceptor-complement lines, the complement representing, asusual, their unspecific, and the aniboceptor their specific, constituent.Abderhalden protests against the intrusion of Ehrlich’s complexnomenclature into the description of phenomena that are probablysimpler than those t o which it was intended t o apply.We mayrecall here, however, the Armstrongs’ views as to the nature offermentls in general (see above), and, in any case, the hydrolyticaction of the defensive ferments and the phenomenon seen, forinstance, in hzemolysis are probably related. That the action ofthe defensive ferments is in some way related t o anaphylaxis38 isnearly certain.Many papers on the defensive ferments published during the yearin the technical medical journals have been of a critical sort,39especially in connexion with the placenta-reaction, which does not35 Abderhalden and F.Wiltlermuth, Zeitsch. physiol. CJmn., 1914, 90, 385 ; A . , i,763 ; Abderhalden and L. Grigorescu, ibid., 419 ; A . , i, 765.36 Biochem. Zeitsch., 1914, 62, 1 ; A., i, 766.37 Munch. nzed. Wochcnsch., 1914, 1167.38 Ann. Report, 1910, 201.3y Compare L. Flatow, Munch. med. Wochensch., 1914, 1168202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.seem t o be successful in the hands of all. A. G. Hogan,lro moreover,could find no improved utilisation of sucrose or lactose as the resultof repeated intraperitoneal injections of t'hese sugars. He did notstudy the action of the serum, but holds that his results prove thatno " immunity " was developed, and that the physiological signi-ficance of Abderhalden's results is theref ore doubtful.We may haveto wait some time before the whole subject can be viewed in properper sp edive.Some Aspects of Intermediary icf etabolisrn.Carbohydrates and Fats.-The fate of sugar in the body remainsa prominent subject of research. Its secrets are stronglyentrenched, but an army of investigators is " nibbling '' a t themand not without success, although the moment f o r a decisiveadvance seems not yet t o have arrived. I gave a good deal of spaceto the subject last year, and must be somewhat briefer here.The growing conviction t'hat one aspect at least of the metabolismof sugar involves a preliminary non-oxidative cleavage resulting inthe production of lactic acid is, in a sense, greatly strengthened bythe researches of J.Pasnas and R. Wagner41 on amphibian muscle.Thzt the lactic acid of muscle takes origin from its carbohydrateshas, of course, been long suspected, but I know of no other experi-mental work that makes the relation between them so clear. Theorigin of one from the other is probably not indeed, in the strictestsense, direct, but Parnas and Wagner make it nearly certain thatthe lactic acid arises from a precursor which stands in intimategenetic relation to t'he carbohydrate.Evidence pointing, although I think with considerable lesscogency, in the same direction is advanced by 0. von Fiirth.42. Onlyif the diet of rabbit.s be rich in sugar is there, in these animals,any excretion of lactic acid as the result of phosphorus poisoning.I n the absence of carbohydrates there is none.As the increaseis, in any case, relatively small, the author suggests that his experi-ments indicate that the origin of lactic acid from sugar is throughsome intermediary substance, and not direct. There is indeed goodreason to believe that in the muscle fibre the carbohydrate issynthesised into some complex, and from this the lactic acid moredirectly arises. There is little doubt, however, that sugar suffersalso a more direct degradation in the body.I n the endeavour to discover what compounds are related to sugarin the processes of metabolism, many workers have continued to use40 J.Biol. Chem., 1914, 18, 485 ; A , , i, 1157.41 Biochem. Zeitsch., 1914, 61, 387 ; A . , i, 772,42 Ibid., 1914, 64, 131 ; A., i, 1014PHYSIOLOGICAL CHEMISTRY. 203Lusk’s method, which is based on quantitative studies of phlorid-zin diabetes. It is clear that any information regarding the natureof the substances that can yield sugar in the diabetic animal bearsalso on the fate of sugar itself in the normal animal. It is changesin chemical equilibrium in one direction or t-he other that occur.I n Lusk’s method a dog is given phloridzin under carefullystandardised conditions, and its output of sugar and nitrogen deter-mined. I f the addition to a uniform dietary of the substance understudy results in an increase of urinary sugar, without disturbancein the output of nitrogen, it is assumed that the substance isdirectly converted into sugar.I f it acts only indirectly, increasingsugar by increasing metabolism, then the nitrogen will be increasedalso. I n the former case the amount of ‘( extra ” sugar formed willbe sgme guide as to the chemical processes involved. It mayindicate, for instance, whether all, or only some, of the carbonatoms present in the molecule of the substance being studied areconcerned in the formation of sugar.Lusk’s method seems usually to give trustworthy and definiteinformation, and the more one learns about the truly remarkableaction of phloridzin in determining that everything capable ofyielding sugar in the a’nimal body shall be promptly excreted assugar, the more does one desire better information concerning theprecise mechanism of its action.The extensive use in recent yearsof the drug has helped us but little in this respect. To A.. I.Ringer and E. M. Frankel43 we owe some information as to thetime relations of the glucogenetic phenomena. They find that afterthe administration of dextrose itself the curve of sugar-eliminationreaches in two hours a point which, after the administration ofsuch a precursor as propionic acid, is only reached in four or fivehours. There is a definite time required for the processes ofconversion.With regard t o the nature of substances capable of yieldingsugar I will refer only t o the papers of the present year. Ringerand Frankel 44 find t’hat dihydroxyacetone is glucogenetic, and, inone experiment a t least, it was quantitatively converted intodextrose in the phloridzinised dog.I. Greenwald45 states that thesame is true for citric acid, and P. Schwenken46 claims to haveobtained sugar quantitatively from acrylic acid. The work of thelast few years has shown that, whilst some substances which wemight expect to yield sugar easily wholly fail to do so, positiveresults are obtained with a number of substances of very diverse43 J. Biol. Chein., 1914, 18, 81 ; A., i, 902.44 Ibid., 233 ; A . i, 1025.45 Ibid., 17, xxxiv; A., i , 629.46 Beitr. Physiol., 1914, 1, 140 ; A., i, 1156204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.constitution, a noteworthy proportion of these being compoundswith three carbon atoms in the molecule.Every result obtainedwith this technique is of value as illustrating chemical possibilitiesin metabolism, but it is sure that some caution may be necessarybefore i t is concluded that every substance proved on these linesto be glucogenetic is really an intermediary in the normal meta-bolism of carbohydrates.Imentioned last year that whilst the claims of pyruvaldehyde(methylglyoxal) t o be a normal intermediary metabolite have muchto support them, those of pyruvic acid are less clear. A. I.Ringer, who has had much experience of the method, states thatpyruvic acid when administered to the phloridzinised animal some-times gives large quantities of dextirose and sometime8 none a t all.Either the condition of the animal becomes an important factor,or else idiosyncracy enters into the phenomenon. The resultssuggest, to my mind, that the acid is a foreign substance, and nota normal obligatory stage in sugar metabolism.P. A. Levene andG. M. Meyer 47 confirm this view, for they find that isolated animaltissues which, as we know, rapidly act on pyruvaldehyde, have,under aseptic conditions, no effect on the acid. I must not forgetindeed that I. Smedley (Mrs. MacLean) and Eva Lubrzynska48have advanced an ingenious hypothesis suggesting that pyruvicacid, formed in the body as a decomposition product of carbo-hydrate, is the starting point for the physiological synthesis offatty acids. Better evidence for the physiological nature ofpyruvic acid seems called for, however.Ringer and Frankel,49 inan endeavour to analyse the precise fate of this acid when adminis-tered, have obsarved an interesting set of facts with somewhatspecial bearings. When acetaldehyde or propaldehyde is injectedinto a phloridzinised animal there is a large absolute increase inthe dextrose eliminated, greater indeed than would occur if thewhole of the aldehyde were converted into sugar. This is associatednot with an increase, but with a decrease in the loss of nitrogento the body, and there is also a marked decrease in the excretionof acetone, P-hydroxybutyric acid, and acetoacetic acid. Clearlysomething mom complicated than direct conversion occurs. Theeflect of the aldehyde is remarkable, since neither ethyl alcohol noracetic acid has any appreciable influence on the metabolism of thediabetic dog, whilst propyl alcohol and propionic acid, althoughknown to suffer direct conversion into sugar, do not produce theSometimes the phloridzin method gives uncertain results.47 J.Biol. Chem., 1914, 18, 469 ; A . , i, 1157.49 J. Biol. Chem., 1914, 16, 563 ; A., i, 357.BiocAem. J., 1913, 7, 364 ; A., 1913, i, 1014PHYSIOLOGICAL CHEMISTRY. 205secondary effects mentioned. It would seem as though the aldehydegroup must exercise a special influence. The facts indeed haveled Ringer to consider the possibility that dextrose itself may oweits power of inhibiting the excretion of the acetone substances (its( ( antiketogenetic " action) to its aldehyde group. In specialexpesiments he found that gluconic acid, although differing fromdextrose only in the replacement of the aldehyde group bycarboxyl, has no antiketogenetic power.He advances finally atheory of diabetes and of acidosis on lines somewhat similar tothose foreshadowed in my Report last year. When P-hydroxy-butyric acid arises from the oxidation of fatty acids and amino-acids in metabolism, i t forms, under normal conditions, a glucosidewith dextrose, and only in this combination is it further meta-bolised. In diabetes (experimental or clinical) the power to formthis glucoside union is absent, and its failure is a t the bottom ofall the chemical disturbances. Such, very partly and incompletelystated, is Ringer's thesis, and in the paper quoted he supports itwith ingenious arguments.W. M.Marriott,50 however, calls attention to the fact that thediabetic, whilst unable to deal with Z-P-hydroxybutyric acid, fullyoxidises the corresponding d-acid. To explain this on Ringer'slines, he ventures upon the hypothesis that the d-acid combineswith the P-form of dextrose, whilst the Z-acid requires the a-form,in which the diabetic is presumably deficient. By this time,however, the theory has got far beyond the facts.We are still far from being able to describe fully the events ofcarbohydrate metjabohm, but it is sure that ultimate success willarise from experiments based on clear thought on chemical lines.The influence of the nervous system and the balance of glandularactivities condition events in the body, but the ultimate eventsthemselves are chemical.They are definite molecular reactionsproceeding smoothly in health whilst interrupted and diverted indisease.It is sure, of course, that apart from the effect of disturbances inthe internal secretions of the body the normal progress of thesereactions, like that of other chemical events in the body, is affectedby less specific factors, its by variation in the hydrion-concentrationin the blood and tissues. P. Rona and G. G. Wilenko have shown,in two interesting papers, how marked is the influence of thisfactor on the utilisation of sugar by the heart:' and on the glyco-lysis62 which occurs in the blood.5o J. Biol. C'hem., 1914, 18, 241.51 Biochem. Zeitsch., 1914, 59, 173 ; A., i, 350.Ibid., 1914, 62, 1 ; A., i, 766206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.An excised heart kept active by artificial perfusioii is anadmirable object for the study of such factors quantibatively, andthe authors quoted show that extremely small departures from anormal hydrion-concentration, in the direction of acidity, in thefluid perfused prevents the consumption of sugar by the survivingorgan.Similar small departures from a normal reaction inhibitthe familiar disappearance of sugar which occurs when normalblood is kept. It is clear that thme facts are of much importancein connexion with the acidosis which is characteristic of diabetes.I have discussed in considerable detail the effects of changes inthe reaciion of the body fluids on physiological processes in theOliver-Sharpey lectures for the current year (Lancet, 1914).The Creatine Problem.-This elusive but always attractive sub-ject has been well to the front during the year.What is themeaning of the creatine of muscle; what is its origin; and whatits relation to urinary creatine and creatinine? A truly astonish-ing amount of good and quantitative work has been put into theendeavour to find answers t o these questions; but the answersare not yet complete. 0. Folin, to whose methods we owe thepossibility of quantitative study, has himself returned to the groundthis year. Before reviewing what he has written, however, I willdeal with a paper by S. R. Benedict and E. Osterberg,53 because areference to their work and views Pollows logically, as will be seen,on my discussion of the phenomena due to phloridzin injection.Creatine is known to appear in the urine of adults as the resulteither (i) of starvation, inanition, and general conditions involvingloss of body tissue, or (ii) of failure on the part of the body toobtain or make due use of carbohydrate, as in diabetes.Either ofthese may be looked upon as the essential cause of creatinuria, andbe considered as involving the other. Some believe that the originof the urinary creatine is to be sought alone in tissue-wastage,which involves an abnormal liberation of tissue (muscle)-creatine.From this point of view it is easy to indicate that excessive tissue-waste is characteristic of diabetes, and the undoubted experirnentalfact that giving carbohydrate alone, without protein, will preventthe excretion of creatine during inanition, can be explained asmerely a part of the ordinary sparing effect of carbohydrate onprotein metabolism.It spares the muscle protein structure andtherefore prevents the liberation of the associated creatine. Onthe other hand, there are those who believe, following a suggestionoriginally due to Cathcart, that creatine is a substance the func-tions and fate of which are intimately bound up with the normalprocesses of carbohydrate metabolism. When the latter are in5% J. Biol. Chem., 1914, 18, 195 ; A., i, 10%PHYSIOLOGICAL CHEMISTRY. 207abeyance, as in diabetes, the creatine, which is otherwise used,perhaps synthetically, in metabolism, appears in the urine.Fromthis point of view the effect of general starvation in inducingcreatinuria is actually the result of specific carbohydrate starva-tion, and the preventive effect of giving carbohydrate alone hasbeen held to prove it. To these two alternatives Benedict andijsterberg addressed themselves. They realised that the phlorid-zinised animal, which suffers both from an increased nitrogenousbreakdown and from inability to use carbohydrate, is an excellentexperimental objectl on which t o test them. They worked, there-fore, with animals under the influence of this drug and undervarious nutritive conditions. The dogs, when fasting, lost fleshrapidly, and their excretion of creatine was high. Benedict andOsterberg’s experiments, however, a t once established the crucialfact that if the animals were fed with creatine-free protein food,in such amounts that the loss of nitrogen to the body was coveredand even more than covered, the high elimination of creatineremained quite unaffected.The figures obtained served “ todemonstrate beyond any argument that the creatine eliminatedby these phloridzinised animals did not represent creatine pre-formed in the muscle, and that muscle ‘disintegration’ played nopart in furnishing the creatine put out.” Now when the animalsa t the close of the experiment were killed, it was found that thetotal creatine of the muscle, in spite of the prolonged hyper-ex-cretion of the substance, was by no means reduced, but was inexcess of the normal.This the observers held to be due to thecircumstance that, because utilisation of creatine is prevented bythe drug, a large amount circulates, and the tissues become morethan normally saturated with it. The fact is in any case not inharmony with the view which has been held by some that’ the totalcreatine of the muscles is depleted in proportion tot the amounteliminated in the urine. The experiments indicate, indeed, thatcreatine is normally produced, and subsequently used or destroyed,in larger amounts than is usually supposed. In simple fasting theamount excreted daily is but small, but this yields no evidenceas t o the amount actually produced, any more than a minimal gradeof glycosuria, resulting in the excretion of a few grams of sugarin the day, would be a measure of sugar-production in the body.Phloridzin makes the animal “ diabetic ” in respect of creatine,as well as in respect of sugar, and the drug, by interference withtheir normal utilisation or destruction, brings them both to lightin the urine.Benedict and Osterberg conclude that the fate ofthe one substance is related to that of tlie other, and are them-selves in agreement with the view that the power of the organis208 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to metabolise the creatine which i t forms “is directly related t ocertain processes chief among which appears to be the utilisatioiiof carbohydrate.”0. Folin has published papers during the year dealing with thetechnical side of the subject, and has given us important improve-menix3 in the methods for estimating creatine and creatinine inthe urine, blood, and tissues, as well as supplying experimentaldata relating to the creatine in each of these.To judge, however,from a paper published conjointly with W. Denis,54 his mindhas been occupied with an aspect of the subject which, if funda-mental, is somewhat special. He is concerned for the moment, notso much with the dynamics of creatine, but with the question asto what precisely is the nature of its association with muscle sub-stance. “Creatine must,” write Folin and Denis, “be a wasteproduct or a synthetic product serving some special function, oras a synthetic product it may in fact be a part of the living activeprotoplasm. We believe that the last-named alternative representsthe facts, and in support of this hypothesis we now propose toshow that the so-called creatine of muscle is a post-mortem product,and there is very little creatine in living muscle.”The last statement implies that, when our estimations of creatineare made, the mechanical destruction of the muscle fibres liberatesthe base from a complex in which its identity had been in somesense or other submerged. It is not clear, to me a t least, whencreatine (or any other tangible tissue constituent) is spoken of asbeing ‘‘ part of the living active protoplasm,” whether i t is supposedto exist in some large molecule, from any part of which the creatinestructure is wholly absent, but whence the base emerges with itsown identity established as the result of extensive molecularrearrangements at the moment of protoplasmic death, or whethercre,atine qua creatine is supposed to be linked up in a complexand merely liberated post-mortem by such a process as hydrolysis.Folin and Denis seem clear a t any rate that the living muscle doesnot contain free creatine, nor, as I understand them, any looseadsorption compound of the base.Their proof of this is, however,by no means a direct one. They argue somewhat as follows. Muscleyields, post-mortem, from forty to fifty times as much creatine per100 grams of substance as ever blood is found t o contain. It cannot,therefore, be in ordinary equilibrium with the blood. There isevidently “some definite effective force or condition by which thecreatine is held fast in the muscle.” When fresh creatine entersthe blood it is freely taken up by the already creatine-laden tissues,a fact for which new experiments described in the paper now64 J.Biol. Chem., 1914, 17, 493; A., i, 767PHYSIOLOGICAL CHEMISTRY. 209being quoted give further evidence. If I understand the authorsrightly, it is essentially this disproportion between the concentra-tion in the blood and muscle which has led them to their very wide-reaching conclusion. Without asserting that the creatine inmuscle is simply adsorbed, I feel wholly unable to admit that thedisproportion as discussed cannot be explained by the formationof an ordinary adsorption compound with the muscle colloids.Inone of the experiments given in the paper an anmthetised dog,the muscles of which had yielded on preliminary analysis 544 mg.of creatine per 100 grams of tissue, received 3 grams of the baseby way of the small intestine. As a result the muscles yielded,after a certain interval, 689 mg. per 100 grams, showing anincrease of 26 per cent. Now the extra 145 mg. could hardlyhave come t o form part of the bioplasm during the course of theexperiment. Few a t least of those who conceive of the bioplasmas an entity, distinct from the general metmaplasmic cell contents,would admit that, as t,he result of a mere increase in the supplyof a given constituent, i t could immediately suffer so considerablea change in its constitution.If it could undergo any such con-stitutional changes as the result of variations in supply, therecognised distinction between exogenous and endogenous meta-bolism would hardly be justified. On the other hand, if i t besupposed that the extra amount of creatine found had not yethad time to be tssimilated, the data of the experiment show thatthe muscle with 145 mg. of free creatine per 100 grams was inequilibrium wit’h blood containing only 80 mg. I f this differencecan exist without the hypothetical entry of the base into the muscleprotoplasm there is no good reason to believe that larger differencescould not exist on similar terms.I do not pretend to know as much about the physiology ofcreatine as does Folin, and I owe to him most of what I do knowabout it, but I have ventured on this discussion because I feelthat certain conceptions which underlie the argument used byFolin and Denis in their paper have a general bearing on our viewsrespecting equilibrium in the living cell, and are, in my opinion,likely to confuse the issues.Many other papers which have dealt with creatine and creatinineduring the year cannot be quoted here.The physiological inde-pendence of the two substances originally demonstrated by Folinseems to be fully illustrated by the work of Benedict and Osterberg,although Schaffer seems inclined to support Morris and Fine inreturning to the older view that the latter arises within the musclefrom the former as a precursor. Folin himself now teaches that“when a tissue dies the postrmortem product, creatine, is set free,REP.-VOL. XI.210 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.whereas in the course of the normal replaceable breakdown, whichwe call tissuemetabolism, the product split off is usually (normally)not creatine but creatinine.” Whether on these lines they havea common precursor of a more definite sort than the bioplasm itselfhs does not say. It would certainly be remarkable if two meta-bolitm so intimately related chemically should have no relation atall in metabolism.The extraordinary steadiness of creatinine-output during verywide fluctuations in exogenous nitrogen which has led us, againunder Folin’s guidance, to regard its amount as the best measureof msential tissue-metabolism, is once more strikingly confirmed ina paper by A.E. Taylor and W. C. Rose.55 When, by alteringthe protein intake, the urinary nitrogen was made t o vary between7.4 grams and 30.2 grams, the creatinine only varied between0.63 and 0.68 gram.Vitamines.Interest continues to be centred in those accessory food substances of unknown nature for which Funk proposed the nowfamiliar name of vit’amines.T. B. Osborne, L. B. Mendel, and Edna L. Ferry56 find that thesubstances in milk which have a specific effect in promoting growthin young animals can be separated with the butter-fat. Theirsolubility in fats is further illustrated by the work of E. V.McCollum and Marguerite Davis,57 who find that if fresh butteris saponified and the aqueous solution of its soaps extracted witholive oil dissolved in ether, the oil left on evaporation of the etherhas acquired the property of promoting growth. This observation,unfcrtunately, does not help us in an endeavour to isolate thevitamines.It -is uncertain as yet whether the substance necessaryfor growth is the same as that which can cure the neuritis whichdevelops in fowls fed on polished rice, and the absence of whichfrom a diet is supposed to be responsible f o r the disease b e r i - h i .Funk 55 found that polished rice and a vitaminecontaining fractionfrom yeast constitate together a complete food, and decided that,as the yeast preparation used in these experiments contained nophosphorus, the importance of the phosphorised lipoids in (‘ defi-ciency diseases” is probably small.With A. B. Macallum 59 hehas published observations which do not altogether agree with55 J. Biol. Chem., 1914, 18, 519; A . , i, 1151.Ibid., 1913, 16, 423; A., i, 107.Ibid., 1914, 17, 245 ; A , , i, 1188.58 J. Physiol., 1914, 48, 228 ; A . , i, 768.59 Zeitsch. physiol. Chew&., 1914, 92, 13 ; A . , i, 1017PHYSIOLOGICAL CHEMISTHY. 211Osborne and Mendel's statements as to the vitamine content ofbutter. It was found, further, that cod-liver oil added to polishedrice prevents neuritis from developing, but does not promote growth,so here a t least we seem to have evidence for the existence of morethan cne type of vitamine. This paper contains a photographshowing an extraordinary difference in the development of chickensfed with and without the necessary vitamine supply.E.A. Cooper60 has continued some investlgations on the amountof anti-neuritic substance in certain practical food-stuff s. Thechief point that arise6 from his researches is that voIuntary muscleis poor in the vitamine, so that meat should be supplementedby other foods in the treatment of beri-beri. A hitherto unsus-pected effect of the absence of these accessory substances fromthe diet is suggested in a preliminary way by experiments madeby Funk and Count E. von Schonborn.61 They find that pigeonsfed on artificial food mixtures develop an abnormality in meta-bolism leading to a marked hyperglymmia and a diminution ofglycogen in the liver. This condition was apparently cured bygiving a vitamine fraction from yeast.No one could be more assured than I am (after a good manyyears of experiment) of the real existence and of the nutritiveimportance of these accessory food substances, but I am equallysure that as yet we know nothing of their chemical nature. J. C.Drummond and C. Funk62 have just published a paper which issignificant in its admissions. I n my opinion we have now no trust-worthy evidence for the activity as vitamines of any of the crystal-line substances which Funk has from time t o time separated anddescribed. The paper last mentioned deals with the completefractionation of a crude vitamine fraction f rorn rice polishings.From the polishings Funk63 some time ago separated aiid describeda substance, C,H,,09N,, melting at 2 3 3 O , together with nicotinicacid. The former supposititious substance, however, is nowadmitted, as the result of further study, to be also nicotinic acid,and this is not a curative material a t all. No crystalline substancewith power to cure neuritis has really been separated from ricepolishings.From yeast, on the other hand, Funk once obtained a " curative "substance to which the formula C2,H,,0,N, was ascribed. The melt-ing point of this was 2 2 5 O , but a substance prepared earlier fromthe same source by similar methods melted a t 233O, and the twowere identical in crystalline structure, solubility, and reactions.8o J. Hygiene, 1914, 14, 12 ; A , , i, 777.61 J. Physiot., 1914, 48, 328; A . , i, 1015.62 Biochem. J., 1914, 8, 598.63 J. Physiol., 1913, 46, 173; A . , 1913, i, 936.P 212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYNow of this last substance, when first described, it was remarked :“ Recrystallised from dilute alcohol the substance melts a t 2 3 3 O , atthe same temperature as the curative substance from rice. It givesthe same reactions, and both substances must be therefore con-sidered as identica1.’’G4 The substance from rice, melting a t thattemperature, is, however, as we now learn, nicotinic acid, and it isdifficult to avoid the suspicion that t,he first-mentioned yeast pro-duct, in spite of the elementary analysis (done by Pregl’s methodon 3 to 4 mg. of substance), was nicotinic acid also, I n any case theyeast product showed appreciable curative effects only when mixedwith what was avowedly a nicotinic acid fraction from the samesource, and the latter (although pure nicotinic acid is withoutaction) had itself some curative effect. There is not, I think, a greatdeal to be said for the substance, C24131909N5, as a crystalline vita-mine. As Drummond and Funk were quite unable t o confirm thework of Suzuki, Shimamura, and Odake,G5 who claimed to haveseparated the active substance from rice in the form of it picrate,we have evidently no certain knowledge of any pure substance withthe properties of a vitamine.F. G. HOPKINS.84 J. Phgsiol., 1912, 45, 76.65 Bioehem. Zeitseh., 1912, 43, 89 ; A . , 1912, ii, 980

ISSN:0365-6217    

DOI:10.1039/AR9141100188

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.ALTHOUGH for the year 1914 no results of exceptional importallcehave to be recorded, a number of investigations of considerableinterest relating to soils and plant nutrition have been carried out.The soil problems which have received most attention are thoseconnected with partial sterilisation, absorption of bases, acidity,and the production and movements of nitrates in soils, whilst inthe case of plant nutrition a good deal of attention continues tobe given to the question of stimulants.A t the meeting of the International Commission on the ChemicalAnalysis of Soils, which was held in Munich in Apri1,l the subjectsdiscussed included: (1) the preparation of soil extracts f o r totalanalysis; (2) the estimation of readily soluble soil constituents ;and (3) the estimation of soil acidity.On the assumption that the double silicates in soils belong totwo sharply defined groups, those of the one group readily givingup their bases when treated with a 10 per cent.solution of anelectrolyte, whilst those of the other group, representing the un-weathered rock, are acted on very slowly, a provisional methodhas been devised in which the soil is treated with 10 per cent.ammonium nitrate solution. It was found that the main portionof the bases which dissolvo at all was contained in the first 50 C.C.of the filtrate.It was, however, decided, for obtaining a standard method, toconfine attention for the present to extraction with water contain-ing carbon di.oxide.Of the publications which have appeared during the year maybe mentioned : “ Erniihrungsphysiologisches Praktikum derhoheren Pflanzen,” by V.Grafe ; ‘ I Die Typen der Bodenbildung,”by A. Glinka ; ‘‘ Grundziige der Pflanzenerniihrungslehre undDiingerlehre,” by W. Kleberger; a third edition of Tollens’“ Kurzes Lehrbuch der Kohlenhydrate,” and a third edition ofWahnschaff e’s “ Wissenschaftliche Bodenuntemuchung.”1 Il’ature, 1914, 93, 598.21214 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The A trnosphere.A useful series of analyses of rain-water has been made inSouth Africa: extending over one or two years in the case ofGrahamstown, Kokstad, Bloemfontein, Durban and Cedara, andfor shorter periods at several other places. It is shown that a tGrahamstown and Kokstad the total nitrogen, as ammonia andnitrates, amounts to only 1-88 and '2.00 kilos.per hectare perannum, which is about half the amount found a t Rothamsted.The difference is mainly in the ammonia-nitrogen, which atGrahamstown amounts to only 1-06 kilos., and at Kokstad t o 1.25kilos., per hectare. At the other places much higher results wereobtained, the total nitrogen varying from 5-47 t o 6.98 kilos. perhectare, owing perhaps, in part, to contamination with dust, etc.,especially in the northern parts of the Union, where dust stormsare very frequent. The high results are all due to much largerproportions of ammonia, especially a t Cedara (5.28 kilos.), wherethe nitric nitrogen is quite iiormal (0.97 kilo.per hectare). Theanalyses include chlorides, and in some cases sulphates as well.An important investigation of rain collected in towns has beenundertaken by the Committee for the Investigation of AtmosphericPollution,3 which has already published some monthly resultsobtained a t a number of towns. All the samples are collected ingauges of a standard type, and a standard method is employedfor analysing the rain and other deposits, so as to obtain com-parable results.The series of analyses of rain commenced some years ago a tOttawa4 are being continued, and some analyses of rain and snowhave been made during a few months at Mount Vernon, Iowa?Soils.Acidity in soils is generally t o be attributed t o the decomposi-tion of organic matter under unfavourable conditions, or to anexcessive employment on non-calcareous soils of salts of which thebases are mainly utilised by plants.Instances have also occurredof acidity brought about by the oxidation of iron sulphide.Recent experiments in Japan have shown that acidity occursin certain sandy soils containing only small amounts of humus, andthat this mineral acidity is due to aluminium and iron compoundsC. F. Juritz, Smth African J. Sci., 1914, 10, 170 ; A . , i, 916.Lancet, 1914, ii, 1010, 1110.F. T. Shutt, Exper. Farms Rep., 1914, 265.G. H. Wiesner, Chem. Arms, 1914, 109, 8 5 ; A . , i, 472.ti G. Daikuhara, Bull. Imp. Centr. Agric. Exper. Stat. Japan, 1914, 2, 1 ;A., i, 1211AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.215absorbed by soil colloids. It was found that the application ofammonium sulphate, disodium hydrogen phosphate, and potassiumchloride t o a granit'mandy soil resulted in a reduction of the smallyield of barley, obtained in the unmanured soil, t o almost nothing;whilst with a further addition of calcium carbonate the yield wasenormously increased. The manureld soil was so strongly acidthat the zinc pots in which the experiments were made were per-forated. Further investigation showed that the majority ofJapanese and Corean soils examined were acid, and that in a t leasthalf of them the acidity was due, in part, to colloid absorption ofaluminium and iron compounds. As regards geological origin, itis shown that soils from Mesozoic formations are the most fre-quently acid, then Tertiary, Palzozoic, and diluvium soils.A number of zeolites which were neutral to litmus became acidarter treatment with acetic acid, or extraction with a solution ofpotassium sulphate.Acid kaolins behave towards neutral saltsolutions the same as acid soils, and similar results are obtainedwith alkaline kaolins, after they have been treated with diluteacids; and with granite and other alkaline rocks which have beensubjected to the action of aqueous carbon dioxide for some weeks.Similarly, the acidity of the soils is increased by treatment withdilute acids; mineral acids and formic acid were found t o have thegreatest, and about equal, effects, whilst with acetic acid the in-crease in acidity was much' less, and with oxalic acid very much less.The filtrates from acid soils which have been treated with aneutral salt solution give with ammonia precipitates consistingchiefly of aluminium hydroxide, the amount of which correspondswith the acidity of the soil and with the amount of N-alkali usedin the titration, whilst the filtrates from neutral soils and aqueousextracts of acid soils give no precipitate.The acidity of soils after treatment with different salts variesconsiderably, according to the salt employed.With chlorides, thehighest acidity was obtaiped with potassium salts ; sodium,magnesium, and calcium chlorides produced only about half theacidity or less. Of the different potassium salts, the chloride andthe nitrate give the greatest acidity, whilst the chlorate, sulphate,and iodide gave respectively 90, 80, and 76 per cent.of the acidityproduced by the chloride, taking the averages of a number of soils.As regards the degree of acidity produced by potassium chloridesolutions of different strengths, i t was found that the acidityincreases rapidly a t first, and more slowly afterwards, as thestrength increased from N / 5 0 t o N ; in one case the maximum wasreached a t this point, whilst further slight increases were obtainedin other soils with stronger solutions216 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.From some of the results the conclusion might be drawn thatthe acidity of mineral soils is due to kaolin or acid silicates. I nthis case, kaolins should be strongly acid, and should part witha good deal of aluminium when treated with a salt solution.Kaolins are, however, sometimes neutral, and even alkaline,whilst acid kaolins only give up small amounts of aluminium whentreated with potassium chloride.Both kaolins and soils, whentreated with aluminium and iron chloride solutions, absorb vary-ing amounts of t h e bases and become acid, or, if acid, more so.Iron absorbed in this manner is displaced by aluminium, but notaluminium by iron; the absorbed aluminium and iron are partlyredissolved by potassium chloride solution. It seems probable thatwhen neutral or alkaline soils acquire acid properties by treatmentwith acids, the aluminium o r iron compounds, produced by thaaction of acid, are absorbed by colloids and their positive ionsreplaced by the basic ions of the neutral solution.Some of the results just referred to have been obtained in anindependent investigation on adsorption,' in which it is also shownthat the acidity produced in kaolins and soils by the action ofacids is not due t o absorption of acid; soils which had been treatedwith sulphuric acid, washed with water, and extracted withpotassium nitrate solution failed to give up any further amount ofsulphuric acid.It was also found that soils which were boiledfor some time with concentrated sulphuric acid acquired the samedegree of acidity, when treated with potassium chloride solution, asanother sample which was treated with N/40-acid. I n anotherexperiment,. soils and kaolin were treated with hydrochloric acidand then with barium chloride. They were then washed, againtreated with hydrochloric acid, and the barium estimated; theamount recovered corresponded with 95 per cent.of the acid liber-ated by the soil from the barium chloride, and with 89 per cent. inthe case of kaolin.Thesoil is an old alluvium and a light loam in a good physicalcondition, but deficient in phosphoric acid and especially incalcium carbonate. Although some crops, such as Phaseolzismzcngo, will grow on the soil, most others, such as oats and grain,die as seedlings unless considerable amounts of lime are added.As a result probably of the acid conditions, the soil contains anorganic acid which, in the free state, is very toxic to Andropogotzsorghum, butl not t o all kinds of plants; it even acts as a stimulantwith paddy-rim.The results of a number of plot experiments withAnother case of soil acidity has been noticed in Assam.8J. E. Harris, J. Physical Chem., 1914, 18, 355 ; A., i, 653.9 A, A. Meggitt, Mem. Dcpt. Azric. ITtdia Chem. Ser., 1914, 3, 235 ; A . , i, 1212AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 217and without lime showed that the only unlimed plots that gaveany material crops were those which received alkaline manures,and some which had superphosphate. The action of the latternianure in saving the crop, notwithstanding the increased acidity,is attributed to its stimulating action on root growth, which wouldresult in increased oxidation and in the destruction of the toxicsubstance.Acid clays and loams also occur in considerable amounts inPorto Rico,S where they have an intense red colour, due to thevery complete weathering and the breaking down of the ironsilicates to iron oxide and silica.The climatic conditions whichfavour the production of these soils are frequent rains in hotsummers, which wash out the bases, and if such conditions pre-vailed when the-clays were being produced from felspars, the baseswould be washed away, as soon as liberated, by the co-operation ofcarbon dioxide. As regards the constitution of the acid clay, thefollowing formula is suggested, as it admitx the absorption ofphosphoric acid as well as of bases:OH* Al<~>Si(OH)*O*Si(OH)<~>Al*OH.Although the subject of humus, or of those portions of i t whichdissolve in water or in alkali, continues to receive a fair amountof attention, no very definite results have been published duringthe year.The existence of humic acids seems no longer to be dis-puted; it is now rather a question of the relative importance ofhumic acids and of colloids which absorb bases, since the presenceof both is recognised.By extracting Sphagnum peat with water as long as anythingis dissolved, two distinct colloids have been obtained; and a non-colloid, which is supposed to consist mainly of Berzelius’ apocrenicacid. After subsequent extraction with 4N-ammonia until nothingremains but fibres, undecompmed wood, and a black substance, asolution is obtained which contains another acid, perhaps creriicacid.Suspensions of Sphagrmm and of Sphagnum peat behave verydifferently when treated with ammonia, the peat yielding largeamounts of salts, whilst the Sphagnum itself does not, and i t isshown that the effect on conductivity of the production of saltsfrom the peat exceeds that of adsorption even in concentrationsof 0.01N.No decomposition can very well occur, since humatesare extracted even by O.005N-ammonia solutions.The hard, brittle, insoluble modification of humic acid obtainedby heating a t looo can be rendered soluble by prolonged treatmentI) 0. Loew, Landw. Jcbhrb,, 1914, 46, 161218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with alkali, and the transformation can be followed by means ofconductivity measurements.10It has been shown11 that acid peats sometimes yield as muchsoluble humus when directly treated with alkali as when previouslyextracted with acid, and that even some alkaline peats give upmore than half the total soluble humus when directly treated withalkali.Alkaline peats, when hydrolysed with 20 per cent.hydrochloricacid, yielded small amounts of ammonia, whilst in the case of acidpeat no ammonia was formed.When solutions containing equivalent amounts of ammoniumand potassium hydroxides are employed for extracting humus, itis found that ammonia extracts the larger amount of nitrogen.I n an investigation of some Hawaiian soils,12 i t was found thatthe amount of ammonia present was usually considerably in excessof the nitrates.The amounts of amide, basic, and non-basicnitrogen (probably largely, if not mainly, diamino- and monoamino-acids respectively) varied a good deal; the average amounts wereapproximately 24, 10, and 65 per cent. of the total nitrogen dis-solved by boiling h'ydrochloric acid.The nitrogen of the humus of these soils, extracted by 3 percent. sodium hydroxide, varied, the average amount being about62 per cent. of the total nitrogen. Of this, about 46 per cent. wasprecipitated by neutralising with acid, whilst an excess of acidgave a further precipitate containing about 12 per cent., so thata very considerable portion of the soluble nitrogen of these soils(42 per cent.) becomes soluble in acid after treatment with 3 percent.alkali.As regards other organic, non-humus substances present insoils,13 benzoic acid has been obtained from a subsoil (but not fromthe corresponding surface soil), and m-hydroxytoluic acid has beenfound in several soils and subsoils, but only in any quantity in thelatter. Vanillin, which had hitherto only been detected in soilsby its oldour and by some of its reactions, has now been isolatedfrom some soils in Florida.Alde'hydes have been found in a number of soils-in neutral,alkaline, and acid soils, the latter containing aldehydes more fre-quently than the others. No relation seems t o exist between thecrop being grown and the presence of aldehydes, and they are not10 S. OdBn, Kolloid Zeitsch., 1914, 14, 123; A . , i, 599; also Arkiv.R e i n . Min.Geol., 1914, 5, No. 15 ; A . , i, 1165.J. A. Hanley, J. Agric. Sei., 1914, 6, 63; A., i, 471.12 W. P. Kelley, J. Amer. Chenz. Xoc., 1914, 36, 429, 434, 438; A . , i, 368, 472.l 3 E. C. Shorey, J. Agric. Research, 1914, 1, 357; A., i, 916AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 219confined to any particular locality, being found its far apart asNew York and Mississippi.Both productive and unproductive soils were found to containaldehydes; the majority of positive results were, however, obtainedwith unproductive soils.14Partial Sterilisation of Soils b y Heat and Antiseptics.A study of the effect of various antiseptics on the numbers ofbacteria in the soil, and on the production of ammonia,*5 showed.that whilst the general effect of the different substances is thesame, the amounts of the different antiseptics required to producethe same resuks vary considerably.As regards volatile anti-septics, the amounts required to produce the desired results werefound to be as follows: toluene and carbon disulphide, 0.09;benzene, less than 0.16; cyclohexane, 0-17; chloroform, 0.23 ; ethylether, 0.74; hexane, 0.86; methyl alcohol, 3'2; ethyl alcohol, 4.6per cent. of the weight of soil. The action of non-volatile sub-stances is more complex. Whilst cresol, for instance, produces thesame initial effects on the number of bacteria as toluene, its sub-sequent effects are different in several ways; the number of bacteriaincreases enormously, and the flora is very simple as compared withthat obtained when volatile antiseptics are employed.The highnumbers are, however, not maintained, but fall rapidly. Theincrease in the ammonia is much less than with toluene. Phenolgives similar, and quinol (with only 0'05 per cent.) somewhatsimilar, results, whilst pbenzoquinone, although less potent, alsobehaves similarly. Both quinol and crmol seem t o be utilised bythe surviving bacteria as food.Formaldehyde is normal in its initial behaviour, killing theprotozoa and reducing the number of bacteria; this is foilowed bya marked rise in ammonia, but no increase in bacterial numbers.Pyridine has to be applied a t the rate of 0.8 per cent., as smalleramounts are readily assimilated by the bacteria.The results obtained with the various antiseptics on tomatoesgrown in soils containing disease prganisms showed that form-aldehyde and pyridine are the most effective,; next, cresol, phenol,calcium sulphide, carbon disulphide, toluene, benzene, andpetroleum ; whilst the least effective of the substances used arethe higher homologues of benzene and naphthalene, and some oftheir derivatives. Steam proved, however, to be more effectivethan any of the substances mentioned, and in vegetation experi-ments a steamed soil should always be included as a standard.Itl4 0. Schreiner and J. J. Skinner, J. Fraxklin Inst., 1914, 178, 329 ; A . , i, 1195.l5 E. J. Russell and W. Ruddin, J. Xoc. Chem. Ind., 1913, 32, 1136; A., i, 242220 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.must also be borne in mind that in laboratory experimentsorganisms, once killed, cannot reappear, whilst in culture experi-ments such rigid exclusion is, of course, impracticable, so that anabsolutely identical order of effectiveness of the different antisepticsis not to be expected.The results of pot experiments16 in which buckwheat, wheat rye,and barley were grown in a very pour loam which had been heatedat 9 5 O , 135", and 1 7 5 O , respectively, showed a marked accelera-tion of growth in the case of buckwheat in the soil heated a t 9 5 O ;the other plants were only slightly affected.Heating a t highertemperatures, especially a t 1 7 5 O , retarded gemination and growth.The results of other germination and vegetation experimentsmade in heated soils 17 indicated that a toxic substance is produceda t low temperatures, and in greater amount a t high temperatures,125-150O.When low temperatures are employed, the effect of thetoxin is not lasting, and the growing plant is eventually evenbenefited by the heating. The heated soils were found to containmore soluble inorganic, and especially more soluble organic, matterthan before heating. When exposed t o air, the toxic substance dis-appears, and much of the additional soluble organic matter revertsto its insoluble state. The production of a substance beneficial t oplants, which is attributed to the oxidation of the toxin, might,however, equally well be due to the oxidation of some other sub-stance present.As regards the retarding effect of heating soils on germination,it has been shown18 thst ammonia has this effect, and that heatedsoils may contain ammonia in quantities capable of producingsimilar results.I n addition to changes in the solubility of humus brought aboutby heating soils, a number of experiments have been made withHawaiian soils with reference to the changes in mineral con-stituents.19 It is found that whilst the effects of heating vary withdifferent soils, the amounts of water-soluble manganese, calcium,magnesium, phosphates and sulphates, and bicarbonates increasewlien'soils are dried a t loo0; in about half the soils, the solubilityof the potassium, aluminium, and silica increases, whilst in somethe solubility diminishes.Higher temperatures (250O) and ignitiongive similar results, the changes being sometimes greater and some-times less than those produced a t looo.Solubility in N/5-nitric acid was not altered much by heatingl6 G .W. Wilson, Bwchem. Bull., 1914, 3, 202; A., i, 644.17 Duke of Bedford and S. P. U. Pickering, J. Agric. Xci., 1914, 6, 136.18 E. J. Russell and F. R. Petherbridge, ibid., 1913, 5, 248.l9 W. P. Kelley and W. McGeorge, Hawaii Exper. Stat. B d L , 1913, 30 ;A, i, 1044AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 221the soils a t looo; heating a t 250° in some cases considerably in-creased the solubility of the aluminium, manganese, potassium, andphosphoric acid, whilst calcium and magnesium became less soluble.As regards nitrogen, the usual destruction of nitrates wasobserved, and ammonia was prodaced in abnormally large amounts;there was also a loss of about one-fourth of the total nitrogen whensoils were heated a t 200O.It was observed that when soils weresubjected to the heat of brush fires, ammonification was stimulated,whilst nitrification was checked for a t least two months. Hawaiiansoils are characterised by inertness, and ploughing, followed bythorough tillage a t frequent intervals for several months, is usuallynecessary; the burning of brush without aeration seems to havesimilar effects.The action of lime in partly sterilising soils, to which referencewas made last year, has been further studied, and a number ofdefinite results relating t o the changes in the number of bacteria,ammonification, and nitrification in a variety of soils has beenobtained.20 It is shown that the amount of lime required dependson the character of the soil.A sandy soil poor in organic matterand calcium carbonate required 0.2 to 0.3 per cent., a clayey soilcontaining calcium carbonate reacted with 0-3 to 0.4 per cent.,whilst an acid, sandy soil, and a rich garden soil which containedcalcium cubonate, required from 0.5 to 1 per cent.The greatest increase in Che number of bacteria was obtainedin the acid, sandy soil. With 0.4 per cent. of lime, the numberrose from 5 to 906 millions per gram in ninety days. The highestfinal number (337 millions after 310 days) was obtained with thesGme soil treated with 1 per cent. of lime.This soil also producedthe highest amount of ammonia, 112 per million, as nitrogen, in310 days, whilst the highest amount of nitric nitrogen was foundin a humus-sandy soil, also with 1 per cent. of lime; this soilcontained 210 per million of nitric nitrogen after 380 days.The results of pot experiments in which different amounts oflime were added t o the soil accorded with the nitrification results.Results similar to these were obtained with a heavy soil con-taining calcium carbonate.21 Addition of 0-3-1 per cent. oflime resulted in a marked decrease in the number of bacteria,followed by an immense rise, whilst 5 per cent. of lime completelychecked bacterial growth. I n a calcareous loam, addition of morethan 0.05 per cent. of lime caused diminished nitrification, and onsandy soils, both rich and poor in calcium carbonate, addition ofZo H.B. Hutchinson and K. MacLennan, J. Agric. Sci., 1914, 6, 302.21 F. Miller, Zeitsch. Garmngsphys., 1914, 4, 194 ; Bull. Agric. Intell. PlantDiseases, 1914, 5, 1168222 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.lime up to 0.1 per cent, lowered the production of nitrates fromammonium sulphate, and 0.5 per cent. inhibited nitrification.The effect of heat and of antiseptics on the catalytic power ofsoils, rate of the action of the soil on hydrogen peroxide, has beeninvestigated.22 As regards heat, i t was found that in soils whichhave been heated a t looo the action on hydrogen peroxide isgreatly reduced, and that a further reduction in the action is pro-duced by heating a t 250O.Treatment of the soils with mercuricchloride, phenol, and formaldehyde had no effect, except a slightdiminution in the case of mercuric chloride, which is very difficultcompletely t o remove. From these results the1 conclusion is drawnthat the catalytic properties of soils are not essentially due t oenzymes and microbes, but rather t'o colloids.An investigation of the effects of toluene and carbon disulphide 23applied to soils manured with cotton-seed meal and ammoniumsulphate, respectively, showed that nitrification was not appreciablyaffected by about 0.1 C.C. of toluene per 100 grams of soil; largeramounts were injurious, and even inhibited nitrification for a time.The largest amount employed was 1 C.C.per 100 grams, and fromthe effects of this the soil recovered in about five months.Carbon disulphide had no appreciable effect on the accumulationof nitrates except when more than 1-0 C.C. was added to 100 gramsof soil. A temporary retarding effect was then produced, which,however, did not last long, even with 5 C.C. per 100 grams of soil.Soils in which nitrification is inhibited for twenty weeks bylarge amounts of toluene or carbon disulphide may completelyrecover their nitrifying power without reinoculation.A study of the development of Protozoa24 in various media-ammonifying solutions containing bloodmeal, hornmeal and pep-tone, nitrifying solution, Giltay's denitrifying solution, etc., whichwere inoculated with soil, showed that, a close relation existsbetween the development of Protozoa and that of the bacteria,the maximum activity of both corresponding very closely.Thismay be due to the Protozoa taking an active part in decompositionstaking place; i t seems, however, more probable that the Protozoalive on the bacteria, and this view is supported by the fact thatthe protozoal activity lags slightly behind that of the bacteria.This was very marked in the case of the nitrifying solution, inwhich the encystment of the Ammbz was not complete until somedays after the ammonia had disappeared.Of the different Protozoa, the flagellates generally appeared first,and were almost immediately followed by the ciliates. These, afterH. Kappen, Bied. Zentr., 1914, 43, 145 ; A., i, 644.A.Cunningham and F. Lohnis, Centr. Bakt. Par,, 1914, ii, 39, 596.23 P. L. Gainey, Csntr. Bakt. Par., 1914, ii, 39, 584; A., i, 236AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 223a prolonged period of activity, encyst, and are followed by theAmoebae, which seem to prefer a medium containing few or noactive Protozoa.Practically the same fauna was found in each of the solutionsemployed, and an associatioln of certain Protozoa with definitespecies of bacteria was, in the case of the Ameba, in the nitrify-ing solution.As regards the effect of heat on active and encysted Protozoa,it is shown that the active forms are killed a t 44--54O, flagellatesbeing the least, and ciliates the most, resistant, whilst the cysts arekilled a t 70--72O. I n the case of soils which cool more slowly thanliquid cultures, it is considered probable that a temperature of55-60°25 would probably be as effective as 65-70° on solutions.A mmom'fica tion, Nitrification, and Denitrification.I n order to ascertain the relative powers of various ammonifyingorganisms under different conditions, a series of experiments hasbeen made in which three different soils were manured with fourdifferent nitrogenous substances, and inoculated with pure culturesof ammonifying organisms.26 It was found that with the sameorganism the ammonifying power depends a good deal on thenature of both the soil and the manure, so that it cannot definitelybe decided which, of the fifteen organisms used, is the best.Onthe whole, B.tumescens seems to be the most efficient. The highestefficiency with a manure was shown by B. mycoides, whilst withpeptone Sarcina Zutea gave the highest results. With dried bloodand fish guano, B. mycoides showed o-n'ly a moderate ammonifyingpower.Taking ammonification as a criterion of availability, the resultsindicate that dried blood is inferior to fish guano and cottonseedmeal.Results of considerable interest have been obtained in an investi-gation on the nitrification of ammonium salts, the object of whichwas to ascertain what intermediate products are formed.27 Theexperiments were made in filters, which were inoculated fromactively nitrifying sewage filters. The compounds identified werehydroxylamine salts, which were estimated, and salts of hypo-nitrous and nitrous acids, and there was always some loss ofnitrogen. The results are in accordance with the view that theprocw consists of successive hydroxylation of hydrogen atoms, andsubsequent elimination of water. It is, however, not evident that25 E.J. Russell and H. R . Hutchinson, J. Agric. Sci., 1913, 5, 152.26 C. B. Lipman and P. S. Burgess, Univ. CaZ. Publ. Agric. Sci., 1914, 1, 141. '' E. M. Mumford, P., 1914, 30, 36224 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.these initial changes were brought about by the nitrifyingorganisms, as a mixed culture was used. I n any case, the resultsare of great interest.That intermediate substances are produced by nitrifying organ-isms seems to be proved by a number of experiments which havebeen made on the rate of nitrification of ammonium salts andvarious organic compounds.28 The substances were sub jetted to theaction of a mixed culture of hydrolytic and nitrifying organismsobtained from the secondary contact' beds of a sewage works.A tshort intervals the amounts of nitrogen as ammonia, nitrites, andnitrates were estimated. It was found that carbamide, uric acid,asparagine, glycine, methylamine sulphate, acetamide, ammoniumoxalate, and sulphate all nitrify a t about the same rate, and thatthe maximum amount of nitrogen recovered as nitrate was 95 percent., owing, presumably, to losses by aeration and by the inter-action of ammonia and nitrous acid.The chief interest in these experiments is the temporary dis-appearance of nitrogen in the case of the ammonium salts.Afterfifty-seven days, only 57 per cent. of the total nitrogen of theammonium sulphate added was present in the three forms, and67 per cent. in the case of ammonium oxalate, indicating the pres-ence of some compound intermediate between ammonia and nitrousacid, containing about 40 per cent., more or less, of the totalnitrogen.Thiocarbamide and aniline sulphate failed to nitrify. Thelatter substance is probably decomposed into ammonia and phenol,the phenol being a t once destroyed by the bacteria; 90 per cent. ofthe nitrogen was recovered as ammonia.I n order to ascertain the influence of season and cultivation onthe activity of soil bacteria, samples of soil, taken a t intervals ofabout five weeks, were mixed with organic nitrogenous manures,and the rates of amnionification and nitrification determined.29As regards ammonification of such substances as meat, horn, andblood meals, there was a rise from August to October, then atendency to fall in November, and a rise to a maximum inDecember.A minimum was reached in Pebruary, and a lowmaximum in April, followed by a slight fall t o July, and probablyAugust. The nitrification results were similar, except that thespring maximum was in March, whilst the fall commenced in April.The variations in both ammonia and nitrates were slight, owingprobably to the unusually mild winter, and the December maxi-mum is attributed to the same cause.P. M. Beesley, T., 1914, 105, 1014.H.H. Green, Centr. Bakt. Par., 1914, ii, 41, 577; A., i, 1113AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 225I n these experiments, the soil samples were taken both from aport'ion of the experimental field which had received autumn culti-vation arid from another portion which was not touched untilploughed in the spring. Although the crop results showed asuperiority of 30 per cent. as regards nitrogen in favour of autumncultivation, the bacteriological results failed to reveal anydifference.An investigation of the effects of irrigation and of crops on thenitrifying power of soils3* showed that irrigation water caused areduction in nitrification as indicated by laboratory experiments.The effects of crops varied both with the crop and the manure.Soil from lucerne land produced the greatest amount of nitratesfrom ammonium sulphate, whilst 61th dried blood, soil from theoat plots gave the highest results.The lowest nitrifying power,with both manures, was found to belong t o the fallow plots, indicat-ing that all the crops employed have a stimulating action onnitrification.Comparing the soil samples taken a t different depths, i t is shownthat about 90 per cent. of the nitrate found in the first 150 cm.of soil is produced in the top upper 45 cm.A further study of the effect of crops and cultivation onbacterial activity31 has been made with a considerable variety ofsoils, all of which, as frequently happens in the arid soils of Utah,contain plenty of mineral food and calcium carbonate, but notmuch nitrogen.It was found, in the first place, that cultivatedsoils contained about twice as many bacteria as the virgin soi1,thati t produced 30 per cent. more ammonia from dried blood, and twiceas much nitric nitrogen as the virgin soil. Comparing the influenceof the crops, i t is shown that the lucerne soil produced much lessiiitrat'e than the wheat soil. Fallow soil which was hoed containedfewer organisms than the others, but their activity was greater, andtheir production of ammonia and nitrates higher than any of theothers.The results of anzrobic experiments in which organic substances,such as peptone with meat extract, and peptone with dextrose,were inoculated with sewage filter huinus32 showed that half ormore of the gas evolved was hydrogen, the rest being a mixture ofnitrogen and carbon dioxide, varying in quantity according t o thenature of the organic matter.When nitrates are added, nohydrogen is evolved, and there is a greatly increased liberationof nitrogen; a small amount of carbon dioxide is evolved, and aconsiderable amount of methane. Evidence was obtained that theI. G . McBeth and N. R. Smith, Centr. Bakt. Par., 1914, ii, 40, 24.REP.-VOL. XI. Qy1 J. E. Greaves, ibid., 41, 444. 32 W. Hulme, T., 1914, 105, 623226 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.production of nitrites is due to some enzyme secreted by theorganism, the enzyme being again reduced to its natural state bythe nascent hydrogen produced by the organism.The nitratesare then reduced to nitrogen by the action of hydrogen and carbondioxide.Experiments with twenty-eight well-known, spore-producingbacteria showed that twenty of them reduce nitrates in the presenceof dextrose, and seven others in the presence of peptone.% In somecases the nitrites produced seemed to have a toxic effect, whichprevented their accumulation ; in the presence of peptone, however,there was a considerable production of nitrites (up to 4 per cent.with B. tumescens and B. subtilis). Production of nitrites andammonia is found to depend on the composition of the nutritivesolution, and especially on its reaction, alkaline solutions, such asare obtained when peptone is used, being favourable to the pro-duction of nitrites, whilst with acid solutions, such as result fromthe employment of dextrose, ammonia is produced.Experiments with B.tumescens showed that the whole of thenitrogen of the reduced nitrate, which was not in the forms ofammonia and nitrites, was assimilated by the bacteria. The con-clusion drawn from these results is that the object of the reduc-tion of nitrates is to utilise the nitrogen, and not the oxygen.A number of ammonif ying experiments, in which copper, zinc,iron, and lead sulphates were added to a sandy soil in amountsvarying from 0.005 t o 0.25 per cent., showed only relatively slighttoxic effects; the action was generally more marked a t concentra-tions below 0.1 per cent. than at those above that amount. Nostimulation was observed a t any concentration.34Nitrification, on the other hand, was very considerably stimu-lated a t the higher concentrations up to 0.15 per cent., exceptin the case of lead sulphate.A t the lowest concentrations,0.0125 per cent., the metals were either slightly toxic o r withouteffect.Whilst the addition of 4-6 per cent. of calcium carbonate tosoil containing dried blood was found to increase ammonification,twice these amounts of calcium carbonate gave a smaller increasein the ammonia produced, and quite small amounts of magnesiumcarbonate (0.1 per cent.) retarded ammonification.35 The sameamount of magnesium carbonate completely inhibited nitrification ;denitrification, on the other hand, was only retarded by largeramounts of magnesium carbonate.It seems The results, if confirmed, are of considerable interest.~3 M.Klaeser, Ber. deut. bot. Gcs., 1914, 32, 58 ; A., i, 462.34 C. I:. Lipman and P. S. Burgess, Uniu. CaZ. Publ. Agric. Sci., 1914, 1, 127.y5 W. P. Iielley, Bied. Zmtr., 1914, 43, 149 ; A., i, 644AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 227evident, however, that an unexpected complication is introducedinto vegetation experiments on the lime-magnesia ratio, especiallyas the addition of calcium carbonate seems to have no effect indiminishing the toxic action of magnesium carbonate on ammonify-ing and nitrifying organisms.I n order to throw further light on the origin of the accumula-tions of nitrates in certain soils in Colorado and the neighbouringSt'ates, t o which reference was made in previous Reports, theamounts of nitrates have been estimated in a number of shales,sandstones, and limestones of the old inland seas, as well as in alkdiand in ash material collected in its original state.36 The affectedarea, so far as is known, is within the section covered by the oldCretaceous and Tertiary seas, and it is found that large amountsof nitrates are present in the rocks of these formations, whilst theJurassic shales and sandstones contain much less.The maximumamount of sodium nitrate in Cretaceous shales was more than 1 percent., whilst alkali was found to contain as much as 3-35 per cent.The high local results are attributed to the low rainfall, andespecially to the protecting covering of clay.Taking the averageamount of sodium nitrate in fifty-eight samples as 0.104 per cent.,it is calculated that the amount present in the Book Cliffs areain Utah and Colorado would be a t least 90 million tons.The results, along with those previously obtained, seem clearlyLo indicate that the nitrates of the affected areas are derived fromthe accumulations of ancient deposits.On the other hand, evidence has been obtained, by means ofnitrification experiments with Colorado soils, that not only the soilsfrom areas in the incipient stage of steririty, but normal soils aswell, have a very much greater nitrifying power than foreign soils.37The nitrifying flora of the Colorado soils seems to be distinct fromthat usually found in other soils, either consisting of quite differentorganisms or else of different strains.Whilst other soils producethe largest average yields of nitrates from dried blood, next fromammonium cairbonate, and least from ammonium sulphate, withColorado soils the order is reversed. Chlorides inhibit nitrifica-tion, whilst large amounts of nitrates seem to be without effect.On the shength of these and previous results, showing the highstmmonifying power which these soils were found t o possess, andalso the presence of a l p , chiefly Nostocaceae, for nitrogen-fixingorganisms to feed on, the opinion that the high amounts of nitratesare derived from atmospheric nitrogen is maintained.Whilst the theory that the nitrates are mainly derived from the36 R. Stewart and W.Peterson, Utah. Agric. Coll. Exper. Stat, Bull., 1914, 134 ;37 W. G. Sackett, Agric. Exper. Stat. c'ol. A g r i c . 002. Bull., 1914, 193.A., 1915, i, 51.Q 228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.deposits of the old inland seas seenis the more probable for severalreasons, the Colorado nitrifying organisms seem to be quiteexceptionally active, and it would be interesting if they shouldprove to be related to Winogradsky’s vigorous Quito orga,nism.It has been suggested that the latter is descended from still moreactive microbes responsible for the Chile nitrate deposits.Movements of Nitrates in Soils.The observations made some time ago by Miintz and Gaudechonon the extreme slowness with which nitrates diffuse in arablesoil have been confirmed by several experiments.38 I n sandyand clayey loam containing 13-5 and 16.8 per cent.of water,only relatively small amounts of nitrates diffused to a distance of15 cm. in four months; a considerable diffusion in that time didnot extend beyond 10 cm. Under practical conditions, diffusionis therefore comparatively unimportant, nitrates being carrieddown into the subsoil by rain, and again brought t o tlie surfaceby capillarity. I n a dry season, nitrates which were depositeda t a depth of 25 cm. rose in eleven days t o within 8 cm. of thesurface, whilst nitrates deposited a t a greater depth rose more than40 cm. in a month.I n order to show the effect of the same amount of nitrates atdifferent depths on the growth of beet, five small plots werearranged, in which the nitrate (500 kilos.per hectare) was applieda t depths of 5, 10, 17, and 30 cm. respectively. The experimentsalso included an unmanured plot, and a similar series of plotswithout a crop. Estimations of nitrates in samples of the soilstaken a t different depths from April 15th to August 16th, and atdifferent depths down to 40 cm., showed that on the fallow plotsthe effect of rain was to distribute the nitrates in the zone betweeii10 and 30 cm., and to increase the nitrates between 30 and 40 cm.;there was no loss of nitrates. As regards the beet plots, it wasshown that the deep application of nitrates gave the best yield,owing to tlie better distribution of the nitrates. This is attributedto the upward movement brought about by the growing crop duringthe period of active vegetation, which seenis to result in a betterdistribution than that caused by rain.It is therefore consideredundesirable, as well as unnecessary, t o apply the manure in instal-ments. This would not apply to a winter crop in a wet climate,when the advantages of autumn manuring with nitrates may bemore than counterbalanced by losses.A study of the amounts of nitrates in arable soils, based on theresulta of numerous estimations of nitrates in cropped and un-Y8 L Malyaus and G. Lefort, Ann. Sci. Agrm., 1913, [iv], 2, ii, 705AGRICULTURAL CHEMlSTRY AND VEGETABLE PHYSIOLOGY. 229cropped soils a t different times of the year, showed that the amountsrarely exceeded 6 per million in sandy soil, 23 per million inloam, and 14 per million in clay soil.39 These maximum amountscorrespond, respectively, with about 30, 130, and 70 kilos.perhectare to a depth of 45 cm. The accumulation of nitrates wasgenerally found to take place most rapidly in the late spring orearly summer, after which the soils usually showed little, if any,gain in nitrates, and frequently a loss. I n the hot, dry autumnof 1911, however, the accuniulation went on in some cases untilSeptember.Comparing different kinds of soils, it was found that the amountsof nitrates varied more on loains than 011 clays and sands. I n claysoils, the winter losses were less; 011 the other hand, they accumu-lated siiialler amounts in June and July.Fallow soils were found to contain more nitrates than croppedsoils in the late summer and early autumn, allowing for theamounts taken up by the crop.The rapid rise in the amounts ofiiitratcs in the spring takes place, not immediately, but some timeafter the warm weather begins.An investigation, in some respects similar t o the one just referredto, has been made at Scania, in Sweden.*O Nitrates were estimateda t intervals of seven to ten days, to a depth of 30 cm., in the soilof a field on which different crops were grown successively from 1907to 1911; from 1909, fallow plots were included. In the croppedsoil, the amount of nitrogen as nitrates never exceeded 22 perniillion, whilstl in the bare soil the maximum was 33 per million.Comparing the amounts of nitrates in the plots under differentcrops, the maximum amounts of nitrogen were 14 per million inthe case of beet, 8 to 9 per million with wheat and peas, whilstuiider grass ths lowest results were obtained-1.5 per million.When, however, the grass was dug in, the nitric nitrogen rose t o6 per niillion, and by the middle of November to 31 per million.Application of dung resulted in vigorous nitrification, after whichthere was a fall in the amounts of nitrates, due partly to the wheat,crop and partly t o leaching by rain, so that by the spring theamount of nitrates in the soil was low.I n the early summer therewas again a rise, due to increased nitrification, and perhaps to aniovement of nitrates from the subsoil upwards, which, however,was not maintained, owing t o increased assimilation by the crop.The effect of vegetation and tillage was shown by an experimentin which a grass plot was divided into three parts, one of whichremained under grass, whilst the second was freed from vegetation,j Y E.J. Russell, J. Agric. Xci., 1914, 6, 18 ; A., i, 471.Jo RI. M'eibull, K. landtbr. Handl. Z'idskr., 1914, 53, 6 5 ; A., 1915, i, 61230 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and the third dug to a depth of 30 cm. On the three divisions, thenitrogen as nitrates averaged, respectively, 2.4, 6-5, and 11.3 permillion.I n order to ascertain whether i t is possible t o detect the pointa t which nitrogenous manures become necessary, nitrates wereestimated, during July and August, in eight unmanured plotsunder sugar-beet.The yields were estimated both on the un-manured and manured plots. Indications were obtained that wherethe nitrogen as nitrates fell to 2 per million by the end of July,applicatJons of nitrogenous manures resulted in a fairly largeincrease in the yield, whilst with a later fall in the nitrates the effectof nitrogenous manure is less marked. Similar results were obtainedwith other crops. I n an experiment with mangolds, where nitro-genous manure gave a large increase, the unmanured plot was foundto contain only 2 per million of nitric nitrogen as early as June.The " critical " period will vary with different crops.Toxins cund Stimulants.Reference has already been made to an organic substance foundin an acid soil which is toxic to one kind of plant and stimulatingto another; also t o a tonic condition produced by heating Boils,attributed to the formation of an organic toxin, but possibly dueto ammonia, which, it is known, may be produced in sufficientquantity.I n connexion with the question of the production by plants ofconditions inimical to succeeding plants, experiments with a varietyof plants grown in sand showed that the second crop was consider-ably reduced, and that the third crop was further reduceld.41 Thetoxic action was not confined to plants of the same kind, but wasmanifested in the case of other plants. Similar results wereobtained by adding to the sand roots grown in another pot.Onthe other hand, when the roots of the first crop were removedbefore sowing the second, the toxic effect was reduced somewhat,but, was stiil very marked.Better results were obtained by wash-ing the sand.It is considered possible that the injurious effects may, in part,be due to the production of alkalinity, and it is shown that, ofthe plants employed, those which produce the greatest alkalinity(millet and camelina) suffer the moat when the crop is repeated.I n accordance with the resulk of Whitney and Cameron, it wasfound that soil extracts frequently contained toxic substanceswhich were, however, equally toxic to different plants. When theD. Prianischnikov, Re'v. Ge'n. Sot., 1914, 25, 563 ; A . , i, 1208AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 231extract of a black soil was distilled, and both distillate and residuewere employed for water-cultures, the growth obtained in the dis-tillate was similar to that obtained in a normal solution, whilst theresidue gave very slight growth.When the distillation wascarried out under diminished pressure, growth in the residue wasstill more restricted. The toxicity of the soil extract is entirelyremoved by filtration through charcoal.No toxic effect was observed when three successive crops ofetiolated oats were grown in the same solution.The injurious action of grass growing over the mots of fruittrees varies very considerably, according to the soil. On theshallow and not very rich soil of the Woburn Fruit Farm, whichis on the Oxford clay, the effect is often fatal, whilst a t LongAshton, where the soil is rich and deep, the injurious action ofgrass is only slight.I n the case of an old garden soil at Rarpen-den, no toxic action was observed.The results obtained a t Woburn42 seem to exclude the possibilityof the injuriop effects of grass being due to differences such asthe supply of water, alteration in the aeration of the soil, accumu-lation of carbon dioxide, alkalinity or acidity, etc., so that i t seemsprobable that the action might be explained by the production ofa toxin, either as a root secretion or, perhaps more probably, adecomposition product of the debris of the growing roots.Experiments were accordingly made in which grass was grownover the soil in which the trees were planted, so arranged thatwhilst the grass roots were not in contact with the soil containingthe tree, the leachings would reach the tree roots in a few minutes.Under these conditions, the same injurious effect was observed aswhen the trees and the grass shared the same soil.When, on theother hand, the grass is grown on trays away from the trees, andthe leachings from the grass are exposed to the air for an hour ortwo before being applied to the tree, their action is no longertoxic, but beneficial.The experiments were extended so as to include, instead of trees,a number of other plants, such as tobacco, tomatoes, and mustard,which received the drainage from clover; also Festuca, clover,mustard, and Dactylis, which received in each case leaching fromplants of the same kind grown in trays over the pots.A relductionoccurred in each case, varying according to the plant grown.The beneficial effect of oxidised leachings, already referred to, isalso obtained when the trays containing the grass are removed fromthe pots, provided this is not unduly delayed. If the plants havea Duke of Uedford and S. P. U. Picliering, Zoc. cit232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been injured beyond recovery, and hard-wooded plants soon becomepermanently stunted, no beneficial effect is, of course, t o beexpected.The conclusions drawn from these experiments are that a sub-stance is produced from the roots of all crops, which is toxic t oother plants, and still more so to plants of the same kind, and thatwhen oxidised by air the toxin is converted into a stimulant.There is, however, no evidence that the stimulant is an oxidationproduct from the toxin rather than from some other constituentof the drainage.It does not seem very clear why the leachings from the trays areinjurious to the plants in the pots (presumably drainage from tlicpots would produce similar results if transferred t o the trays)whilst it is without action, as soil solution, before i t drains out ofits own pot.If it should be proved that the stiniulant is formed by theOxidation of the toxin, and not from some other substance, theni t follows that every growing crop results in the formation of astimulant.I n practice the stimulant might be expected t o havemore influence than the toxin, a t any rate on arable land, sincethe toxin would no doubt be oxidised during the interval betweenthe crops.For how long the stimulant resists oxidation remainst o be ascertained.A substance having considerable stimulative properties has beenobtained43 from peat which had been incubated with a mixedculture of aerobic organisms for two weeks. It was found, in thefirst place, that when seedlings of Primula malacoides were treatedtwice in six weeks with an aqueous extract of 0.18 gram of thepeat, the plants grew t o twice the size of other plants not sotreated. Stimulative effects were next obtained with wheat seed-lings by employing a solution of the residue of an alcoholic extractof the peat, and also the phosphotungstic acid precipitate from anaqueous extract of the same residue.A t the end of five weeks, theplants which had been treated with the substance extracted byalcohol showed an increase of 21.1 per cent. over the check plants,which received only the complete plant food, whilst the pots whichhad been treated with the phosphotungstic acid precipitate gave anincrease of 29.4 per cent. Experiments were then made t o comparethe effect of the phosphotungstic acid precipitate with that of thesilver fraction corresponding with Funk's vitamine. I n seven weeksthe pot with the phosphotungstic acid precipitate showed anincrease in dry produce of 22.7 per cent., and the silver fractionan increase of 17.7 per cent.W. B. Rottomley, Proc. Roy. Soc., 1914, [HI, 88, 237 ; An?&.Bot., 1914, 28,531 ; A., i, 1208AGRlCULTURAL CHEMISTRY AKD VEGETABLE PHYSIOLOGY. 233Wheat seedlings in water-cultures with pure food solution alonegained in weight in ten days, after which there was a logs, result-ing in a loss on original weight of 8.4 per cent. in fifty days.Addition of 0.35 per million of the silver fraction resulted in acontinuous increase, and a final gain of 54.9 per cent. in the sameperiod. Results similar t o these were obtained with wheat seed-lings from which the seeds had been removed.No stimulating substance could be obtained from the original,untreated peat.It is suggested that certain substances are formed duringgermination which enable the embryo to utilise the food supplied,and that, after the seedling becomes independent, some other sourcebecomes necessary.The peat stimulant seems t o be able t o takethe place of this substance in both stages of growth, and must,presumably, be formed during the usual huniification processes iiisoils.Whilst the stimulative effects of the substance from bacterisedpeat seem evident, the conclusion that tlie substance is not oiilya stimulant, but is essential, seems hardly justified, since it ispossible t o obtain fully-grown wheat plants in absence of anyorganic matter.I n vegetation experiments with toxic substance and stimulants,much depends on the methoids employed, and it is evident thatresults obtained with water-cultures and in soils cannot be ex-pected to agree closely. I n water-culturw the plants are subjectedt o the action of the whole of the substance added, if not precipi-tated, whiIst in soils the substance may not only be more or lessabsorbed, but may be expected to influence the bacteria as well asthe plants, so that, in addition to the direct toxic or stimulativeeffect, as the case may be, on the plant, an indirect action in thesame direction, or possibly reversed, due to aotion on the soilorganisms, is not a t all unlikely.The results of water-culture experiments with different sub-stances indicate that plants are better able to resist the actionof injurious substances in summer than in spring or winter.44The highest indifferent amounts of zinc sulphate vary, accordingto the season, between 0-2 and 0.04 mg.per litre in the case ofbarley, and between 0.2 and 0.05 mg. with peas. Arsenious acidand arsenites are found t o be more toxic, especially with peas,than arsenic acid and arsenates. Boric acid is less toxic than zincand arsenic, being injurious only when the amount exceeds 10 partsper million.No stimulating effect has been observed with zinc and arsenic a tW. E. Brenchley, Ann. Bot., 1914, 28, 283; A., i, 790234 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.any concentration down to 0.005 mg. per litre in the case of zinc,and 0.02 mg. with arsenic acid. Boric acid, at the rate of 10 partst o 0.05 parts per million, has a stimulative effect on peas; in thecase of barley, the appearance of the plants seems to indicate stimu-lation, but this is not confirmed by the weights of the produce.I n pot experiments with wheat grown in s o i p i t is shown thatzino salts applied in quantitiw up to 0.1 per cent,.have a stimu-lating effect, especially on the production of straw, which showsvery considerable gains. Larger amounts are toxic. Of the differentsalts employed, the nitrate proves to be more active than thecarbonate or phosphate.Copper, as sulphate, applied at the rate of 0.01 t o 0.02 per cent.,has a stimulative action, whilst larger amounts are toxic andsmaller amounts without effect. With manganese phosphate andcarbonate, and cerium oxide and sulphate, the results arenegative.I n an unproductive, sandy loam, which did not respond well t ogeneral manures, t'he application of four different manganese saltsand the dioxide resulted in every case in an increased yield.46Stimulation varied, however, both with the.salt and with theamount added. The best results were obtained with 50 parts permillion of the chloride, which increased the yield by 31 per cent.The smallest gains were obtained with manganese carbonate anddioxide.On the whole, applications of 25 to 50 parts per million, corre-sponding with 14 to 28 kilos. per hectare, gave the best results.Very different results were obtained with a productive clay loam.I n t'his soil, manganese failed to show any appreciable increasewith any manganese salt; sometimes there was a slight depression.Further experiments on the growth of wheat in aqueous extractsof different soils showed that addition of manganese salts hadsimilar effects.In extracts of poor, unprolductive soils, manganesesalts increased growth and the oxidising power of the roots. I nextracts of productive soils, oxidation was again increased, whilstthe growth was diminished. The conclusion drawn from theseresults is that the beneficial action in unproductive soils is due toincreased oxidation resulting in the destruction of toxic substancesin the soil. I n productive soils, injury may result from excessiveoxidation.The results of a field experiment on an acid, clay loam showedthat all of the five crops grown were injured by manganese salts,45 J. A. Voelcker, J. Roy. Ayric. S'oc., 1913, 74, 411 ; A . , i, 1192.46 J. J. Skiliner and M.X. Sullivan, U.27. Dept. Agric. Bull., No. 42, 1914 jA., i, 1196AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 235and that the oxidising power was reduced. Failure is, in this case,attributed t o acidity.Other experimenb with manganese salts have been made, someof which indicate that only small amounts can be applied withadvantage,47 whilst according to others the amounts required areso large that it is doubtful whether the use of manganese salts canbe remunerative.48 This divergence is no doubt due to the differentcharacters of the soils.Alkali salts have both toxic and stimulative actions, accordingto the concentration, on the germination and growth of rice.49The maximum stimulation was obtained with N / 500-solutions inthe case of magnesium sulphate, with N/lOOO-5000 in the caseof magnesium and alkali chlorides, whilst with sodium sulphate,chloride, and carbonate the maximum stimulation was withN/50-100-, N / 100-, and N / 100-500-solutions, respectively.Most of the salts were toxic in concentrations above N/100.When, however, two of the salts, even in iV/lO-solutions, are mixedin suitable proportions, the toxic action of each is more or lesscompletely overcome.This is mainly due to the antagonism ofthe cations, the antagonism of the anions being relatively feeble.It is also shown that bivalent cations are st,rongly antagonistic tounivalent cations, but that univalent cations do not very markedlyantagonise bivalent cations.Neither barium nor strontium can take the place of calcium incounteracting the toxic action of sodium and manganese salts;barium increases the injury, i f anything.I n mixtures of threesalts, all of which are toxic at the concentrations employed, growthis generally better than in two of them.Plant Nutrition and Maizures.Fixation of nitrogen by Azotobacter is found to be greater whenmixed cultures of different strains are employed than with purecultures of the same ba~teria.5~ The presence of humus, even inconsiderable amounts, seems t o have no unfavourable effect onnitrogen-fixation, and small amounts of sodium nitrate have verylittle effect. When, however, the amount of nitrogen as nitrateexceeds 2.5 per cent. of tKe carbon present), fixation of nitrogenis retarded, or checked altogether.As regards the effects ofdifferent forms of nitrogen, humus gives positive results, whilstwith humus from green manure negative resulte are obtained.47 0. M. Shedd, J. Ind. Eng. Chena., 1914, 6, 660; A., i, 1164.48 T. Pfeiffer and E. Blanck, Landw. Versuchs-Stat., 1913, 83, 257 ; A . , i, 243.49 K. Miyake, J. Coll. Agric. Tohoku Imp. Univ., 1914, 5, 211.50 J, Hanzawa, Centr. Bukt, Par., 1914, ii, 41, 573 ; A . , i, 1113236 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.These results seem t o show that in natural soils fixation ofnitrogen can only in very exceptional cases be retarded by thenitrogen compounds present. Nevertheless, the amount of nitrogenfixed in this manner, in ordinary arable soils, must be conipara-tively insignificant, and soils which contain high amounts oforganic carbon and nitrogen, from repeated applications of dung,soon lose much of their carbon and nitrogen when manuring isdiscontinued.This has been found t o occur even when the cropgrown is clover, which in a purely mineral medium, without com-bined nitrogen, leaves a considerable nitrogenous residue.The results of field experiments, in which oats were manuredwith sulphur, showed that no beneficial effect was obtained, theyields being, if anything, slightly depre~sed.5~ P o t experinleiits iuwhich mustard, rape, and clover received sulphur at the rate offrom 3.4 to 13.4 kilos. per hectare, gave negative results.52It has been observed in the case of wheat grown in the absenceof silica that plants which were attacked by rust sufferedseverely, the rust spreading very rapidly.53 It is accordingly sug-gested that cereals grown on dolerite and basalt soils should sufferless from attacks of this kind than when grown on granite soils,provided that the climate and the weather conditions are the same.The losses in nitrogen to which farmyard manure is subjecteldwhen stored may be due to the washing out of soluble substancesby rain, to volatilisation of ammonia, and to the fo'rm of denitrifica-tion, in which nitrogen is liberated, which might perhaps be betterterrned deazotisation, to distinguish it from denitrification withoutloss of nitrogen.It has been shown54 that, of the three processes, the first is muchthe most important t o be avoided. A manure heap exposed to rainfor three months not only lost 24 per cent. of its nitrogen, but morethan 20 per cent.of the dry matter as well. I n six months thelosses rose to more than 34 and 31 per cent. respectively, and therewas also a loss of 8 per cent. of the phosphoric acid.By keeping a heap under cover, the losses of dry matter aridnitrogen were reduced very considerably, and no phosphoric acidwas lost a t all. I n a heap which was sheltered from rain, but keptmoist by watering, the loss of nitrogen was doubled as comparedwith the unwatered heap; there was, however, no very appreciableincrease in the loss of dry matter.Apart from the washing out by rain, the relative importance ofthe losses by volatilisation of ammonia, and by the complete51 T. Pfeiffer and E. Blanck, Landto. Vcrsuchs-Stat., 1914, 83, 358 ; A., i, 469.52 J. A. Voelcker, J, Roy. Agric. SOC., 1913, 74, 419 ; A . , i: 1196.53 14. Lundie, South African J. Sei., 9 ; Chem. AJews, 1914, 110, 200 ; A., i, 1192,5J E. J. Russell and E. H. Richards, J. Bcl. Agric., 1914, 21, 800AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 237reduction of nitrates, must depend a good deal on the weatherconditions. With a succession of showers, with intervals of dryweather long enough to give the maximum production of nitratesa t the surface, losses by denitrification would be very consider-able. That, no doubt, is what happened in the watered heapreferred to, but, on the whole, it is considered more likely thatthe greater loss will usually be in the form of ammonia.A new potassium manure has been prepared from leptite orcurite, a common rock in Central Sweden.55 The mineral, whichcontains up t o 11 per cent. of potash, is heateld with coal and ironfilings in an electric oven, with carbon electrodes, a t about 1SOOO.I n this manner a slag is obtained, which consists chiefly ofpotassium and aluminium silicates, 90 per cent. of the potassiumbeing soluble in hot 20 per cent. hydrochloric acid. As comparedwith potassium suIphate8, the results of pot experiments, in whichthe same amounts of potassium were supplied in the two forms,showed that the “electro-potash,” as the new manure is called,yielded 78 per cent. of the crop obtained with potassium sulphate.From experiments made in the United States, it has been esti-mated that a million tons of potassium chloride per annum couldbe obtained from seaweed.66Methods.Of the papers dealing wkh methods of importance in agriculturallaboratories may be mentioned those on the estimation of carbo-hydrates in plant materials,s7 a colorimetric method for nitritesand nitrate~,5~ methods for estimating acidity and carbonates iiisoils,59 and a modification of Konig, Hasenbaumer and Hassler’siiiethod for estimating the surface of soils.GON. H. J. MILLER.55 H. G. Soderbaum, Kungl. Lmdtbr.-Aknd. Hcindl. Tidskr., 1914, 53, 15.5G “ Production et Coii&oniniation des Engiais Cbiniirlues dms le Polonde.” Rome,5 7 W. A. Davis and A. J. I)niuh, J. Agric. Sci., 1914, 6, 153 ; A , , ii, 58858 E. A. 1,ctts and Miss F. W. Itea, T., 1914, 105, 1157.59 H. 13. Hutchinson and I<. McLennnn, C’he?iz. News, 1914, 110, 61 ; A,, ii, 7841914.A. .T. Daish, ibid., 255.J. Ayric. Sci., 1914, 6, 323.J. A. Hanlcy, J. Ayric. &i., 1914, 6, 58 ; A . , ii, 312

ISSN:0365-6217    

DOI:10.1039/AR9141100213

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

MINERALOGICAL CHEMISTRY.ALTHOUGH the year has not been marked by any outstanding dis-covery serving to open up an entirely new field of research, theprogress to be noted along the familiar channels may be consideredto be more than satisfactory. A short appreciation of the generaltendencies may fitly precede a discussion of the work in detail.The X-ray methods of investigating crystal structure have natur-ally received much attention, both on the part of continentalworkers, who appear to be chiefly attracted by the more theoreticalaspects, and also by W. H. and W. L. Bragg, who, in a series ofbrilliant experimental researches, have succeeded in unravellingthe structure of several elementary and compound substances.Certainly the most striking feature of the work is the remarkabledegree of intimacy to which these authors have carried their struc-tural dissections.They have not been merely content t ofamiliarise us with the general nature of crystal structure, buthave carried their explorations to the utmost limit of chemicalinterest, namely, the atoms. The further development of thisabsorbingly interesting field of work must surely throw light onmany questions now in dispute; in particular, its application tothe simpler cases of polymorphism may well be expected toaccelerate a decision between the present conflicting theoreticalviews.There has been a very marked activity in the province ofchemical crystallography proper. The foundation by Fedorov ofthe method of crystallochemikal analysis very materially enhancesthe value of a crystallographic description, proving, as i t does, thatany substance which has once been measured can be readilyidentified on any subsequent occasion, and without involving theslightest loss of any valuable material.The brief accounts of twocases in which a crystallographic identification of several productswas quite indispensable to the successful issue of a biochemical re-search will, perhaps, convinm the most hardened Philistine thatcrystal-gazers have occasionally their lucid intervals in which theymay be of some use to the more wideawake of their chemical28MINERALOGICAL CHEMISTRY. 239brethren. Among the more conventional pieces of work, the in-vestigations of Wahl are, perhaps, preeminent as being valuablecontributions to our knowledge of the crystalline form of sub-stances which are liquids, or even gases, a t the ordinary tempera-ture.On the theoretical side, there has been a dignified inter-change of opinion between Richards and Barlow and Pope on thechemical aspects of the vaiency volume theory.The systematic physico-chemical investigation of minaralogicalproblems continues to make very obvious advances, especially inthe hands of the American geophysical school. Bowen’s masterlyinvestigation of the ternary system, diopsids-f orsterite-silica,shows both a clear appreciation of the difficulties to be overcomeand a nice discrimination of the methods which are the most likelyt o make for success. The, research may be upheld as a mo’del whichother workers would do well to copy.The exact petrological in-formation that is already beginning to accrue from such investiga-tions is in itself a sufficient repayment for all the trouble involved.Another important work from the same school is that of Fenner onthe various polymorphous modifications of silica ; a significantfeature of this work is the astounding sluggishness of certain poly-morphous transformations, which may be used as an argument infavour of polymerism.The last general topic to be discussed is the problem of “liquidcrystals.” Few subjects have ever awakened the general interestaroused by the discovery of these much-discussed substances byOtto Lehmann; there was a time when it was impossible t o attenda conversazione without being asked t o give an account of theirproperties, or, in default, to swell the audience of a colleague’sdemonstration.It is therefore not surprising that the generalinterest soon began to flag. A new stage was, however, inaugu-rated by the chemical researches of Vorlander, who prepared avast number of new examples in a high state of purity, and alsoadded considerably to the general stock of knowledge, showing thatthe production of the turbid liquid phase is a constitutional featureof a peculiar type of stereochemical configuration. It was, how-ever, reserved for a pure physicist, Bose, to lay the foundation ofa general theory of “anisotropic liquids,” and to substantiate hisCheory by means of a carefully planned series of experiments.Itis indeed fortunate that these experiments, so untimely interruptedby BOSB’S early death, have been continued by others. Mauguin’selectromagnetic researches, in particular, afford a very strikingconfirmation of Bose’s views. Again, the definite proof that thecubic modification of silver iodide does not in reality form liquidcrystals is very suggestive as indicating that a molecular configura240 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion of some chemical complexity is indispensable to a regularorientation of liquid molecules. It is perhaps only to be expectedthat Lehmann should find a difficulty in adapting himself t o thenew views, however much the new researchee add lustre to his dis-coveries. The history of liquid crystals affords a good example ofthe rapidity with which a scientific enigma may be compelled togive up its secret when once it has attracted the attention of anumber of differently equipped workers.The writer believes thatthew Reports will have conspicuously failed in one of their mainobjects if they do not serve t o stimulate a more catholic interestand in a small measure help the specialist' to take up a less detachedattitude towards science as a whole.X-Ray Methods of Exploring Crystal Structures.The progress made in this branch of investigation has alreadyreached a stage a t which the relative merits of the reflection anddiffraction methods may be appraised. The rapid advances madeby the users of the X-ray spectrometer1 are to a large extent duet o the simplicity of the method involved.The various glancingangles, el, 8,, O,, etc., a t which a plane of atoms serves as anefficient reflector, are first determined, and the results are theninterpreted by means of the equation nh= 2d sin 8. I n this equa-tion the factor n has the value l when the reflection is due to amutual reinforcement of pulses provided by successive chemicallyand cryst allograp hically identical planes (first-order reflection atthe angle 0,). Similarly, the co-operation of alternate planes leadsto the second-order reflection, O2 (?t=2), the mutual assistance ofevery third plane to the third-order reflection, O3 (n=3), and soon. The intensity of the reflection diminishes regularly in passingup the orders, except in cases where successive atomic planes differeither as to composition or to their distances apart; even ordersmay become stronger than odd orders, and certain orders inayvanish altogether. An admirable illustration of these effects isgiven by rock salt, the relative reflection intensities from the cubeand octahedral planes being :1st order.2nd order. 3rd order. 4th order.Face (100) ...... 100 18.7 6.25 too weak to measureThe regular decrease of intensity as the scale of orders isascended indicates both a chemical identity and an equality ofspacing of successive cube planes, whilst the periodical rise andfall of intensity in the octahedral plane premises some structuralpeculiarity or other. A glance a t the figure given in last year's,, (111) ......16'5 24'4 3 *1 4 -2W. H. Bragg, Phil. May., 1914, [vi], 27, 881MINERALOGICAL CHEMISTRY, 241Report will reveal the fact that successive cube planes are identicalin every respect, whereas octahedral planes are alternately occupiedby chlorine and sodium atoms. An example in which an “orderanomaly” has necessarily to be referred to’ a difference of spacingis afforded by the diamond (p. 243); in this case the entireabsence of the second-order reflection from the octahedral planeimmediately led t o the correct elucidation of the peculiar andhiglily interesting structure involved.The diffraction method of exploring crystal structure is, ofcourse, based on the production of a Laue radiogram, by placinga crystal in the path of a primary pencil of &--rays and receivingon a photographic plate both the undeviated pencil and thesecondary, deviated beams which are due t o the diffraction or re-flection effect of the internal planes of the crystal.An analysisof the radiogram is then made both with respect t o the patternand the relative intensities of the spots.A cursory examination of the published material is enough t oshow that the employment of the Bragg X-ray spectrometer leadsto a rapid determination of the general features of a particularstructure, and in the simpler cases may even obviate any appealt o the evidence afforded by the Laue radiogram. On the otherhand, although an unaided analysis of the radiogram is apt to leadto inconclusive and even erroneous results, it cannot be deniedthat it not only serves as a check on the spectrometric method, butalso brings with i t an additional quantitative precisioii in the finerdetails.This point will be emphasised under pyrites and hauerite(p. 246). It is obvious, then, that the two methods admirablysupplement one another.An important contribution is that of Friedel,2 who has pointedout t h a t the radiogram does not admit of a decision as t o whethera crystal is endowed with a centre of symmetry. An immediateresult of this is t o rule out any hope of obtaining direct’ evidencesof enantiomorphism, and the announcement in last year’s Report,for example, of a difference between 6- and I-crystals of quartz,must accordingly be withdrawn. A useful table of the theoreticalsymmetry types of radiogram is appended by Friedel, from whichi t appears t h a t the thirty-two classes of crystal symmetry can onlyyield a total of eleven types.I n the cubic system, for instance,the holohedral, holoaxial, and tetrahedral classes are indistinguish-able radiographically, all yielding a holohedral pattern, but thetetartohedral and pyritoliedral classes must both afford the pyrito-hedral type. This deduction, as far as pyrit.es is concerned, hasbeen fully confirmed. The keen disappointment felt by crystallo-a G. Friedel, Compt. rmd., 1913, 157, 1533.REP.--VOL. XI. 242 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.graphers when it was first announced that the undoubtedly tetra-heldral zinc blende yields a holohedral radiogram must now betempered by the knowledge that' no other result could in the natureof things be expected.The year has been characterised by a considerable amount ofwork, and apparently of quite a fundamental character as far asphysics is concerned, on the Debye effects-the influence oftemperature on the atomic vibrations in the crystal edifice.It isinteresting to note that Debye's theory has received a qualitativeconfirmation.4 An obvious diminution in the intensity of thesecondary beams is exhibited by mica when it is kept a t a tempera-ture of 400°, and spots that are faintly visible at the ordinarytemperature are not a t all represented on the photograph. Again,there is no trace whatsoever of any spots when X-rays are passedthrough a crystal of rock salt heated a t 620O.The spectroscopicmethod also indicates a weakening in intensity of reflected rayswith rise of temperature; moreover, the increase of the value d,owing to the general expansion of the crystal (rock salt), is clearlyindicated by a corresponding diminution of the glancing angle, 8,a result which is to be expected from the form of the reflectionequation.X-Ray spectra have been mapped out by de Broglieb by thefollowing ingenious device. Rays are allowed to impinge on acrystal which is mounted on a spectrometer, rotated by clockworka t a rate equal to loo per hour. An intense reflection of rays isthereby produced, and is registered on a photographic plate, a t eachshort interval of time during which the glancing angle has a valuesatisfying the reflection equation nh = 2d sin 8.Since both plateand anticathode are kept fixed throughout ths experiment, thepoint of impingement of the reflected rays gradually moves acrossthe plate, and the latter, on development, reveals the spectrum asa series of bands and lines with great definition. The spectrumappears t o range over several octaves.Stereochemical Deductions from the X-Rag Methods ofInvestigation.We may now proceed to review in detail those crystalline sub-stances the structures of which have been elucidated with a reason-able degree of certainty. I n addition to those now discussed, thereare a certain number of others, amongst them being sulphur andquartz,6 which are admittedly imperfectly characterised ; and theVarious papers in PhysikaZ.Zeitsch. and Ann. Physik.M. Laue and J. St. van der Lingen, Phpika2. Zeitsch., 1914, 15, 75.M. de Broglie, J. Phys., 1914, [v], 4, 101.W. H. Bragg, Proc. Roy. Xoc., 1914, [ A ] , 89, 575MINERALOGICAL CHEMISTRY. 243same is perhaps true for the calcite group of minerals and sodiumnitrate, although the results already obtained vindicate the closeststructural analogies which have ever been claimed for these sub-stances. It seems advisable to postpone discussion of such casesuntil additional evidence is available.Copper.7-Although in point of time the latest to be investi-gated, it is convenient to make a commencement with this element,since the structure proves t o be the simplest of all crystals so farexamined.I n spite of this structural simplicity, however, theactual exploration was accompanied by considerable experimentaldifficulties, owing to the softness of the material, which renders i tvery susceptible to profound structural derangements whenattempts are made to grind artificial planes with appropriatecrystallographic orientations. This difficulty was finally sur-mounted by etching away the external layers so as t o lay bare theFIG. 1.unimpaired structure. The results unhesitatingly point to anarrangement of atoms on the pattern of the centred-face cubeshown in Fig. 1. This arrangement corresponds with the closestpacked cubic arrangement of equal spheres, and with a rhombicdodecahedra1 domain of influence for each copper atom.Diamond.*-The main structural peculiarity of the diamond isthe tetrahedral environment of each carbon atom by its fourimmediate neighbours, a, feature which is obviously of prime stereo-chemical significance.I n the absence of a model, the real natureof the structure is perhaps best realised by the following construc-tion. Take eight sinall cubic cells, four being empty, whilst theremaining four are of the kind shown on a large scale in Fig. 2,that is, provided with a whole carbon atom, 2, a t the centre, anda quarter of an atom a t each of four corners, numbered 1, 6, 7,8, selected tetrahedrally. Now interpose the two kinds of cells7 W. L. Bragg, Phil. illng., 1914, [vi], 28, 355; A., ii, 775.8 W.H. arid W. L. Bragg, Proc. Boy. Soc., 1914, [ A ] , 89, 277.R 244 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in the way shown in Fig. 3, so that the occupied cells are identicallyorientated, but separated from each other by the empty cells. Itis seen that four quarter-atoms now meet a t the centre of thefigure numbered 1, and thus make up a whole atom. (It needscarcely be added that an infinite repetition of the eight cellsthroughout space would lead t o a similar fourfold completion ofall the quarter atoms, so that the assemblage consists in its entiretyof whole atoms.) An imaginative chemist will doubtless see clearevidences of a six-carbon ring-shown, as t o five atoms, by, say,7, 2, 1, 3, 9-and may accordingly be disposed to trace an embryonicbenzene configuration in the structure. Without laying too muchstress on this point, it will be generally agreed, in view of theperfect tetrahedral environment of all the atoms, that the diamondstructure can be regarded as a perfect symbol of the chemistry ofcarbon.I n addition t o its four immediate neighbours a t the distanceFIG.2. FIG. 3.12 71&.a/2, where n denotes the edge-length of the cubelet, eachcarbon atom is symmetrically surrounded by twelve other atoms atthe somewhat greater distance J 5. C I . These twelve atoms have tobe taken into account in any determination of the sphere of influenceof each atom. It has been pointed out by Poppls that the sphereof influence is accordingly a regular tetrahedron, each of the fourcorners of which has been modified by the dodecaliedron to suchan extent that the original triangular faces of the former are cutaway to regular hexagons.Inasmuch as this modified tetrahedrondeviates considerably from the form of a sphere, it is evident thatthe diamond structure corresponds with an extremely loose-packedsystem of spheres. This peculiarity has led Barlow10 t o offer theopinion t h a t X-ray methods may be incapable of correctly de-lo W. Rarlow, Proc. Roy. Xoc., 1914, [ A ] , 91, 1 ; A, ii, 843.L. Foppl, Physikal. Zeitsch., 1914, 15, 191MINERALOGICAL CHEMISTRY. 245ciphering the intimate structure of crystals, and to propose certainmodifications which might tend to bridge the apparent gulfbetween the requirements of the Barlow-Pope theory and the ex-periments of W.H. and W. L. Bragg.Although in the past the many crystallographical and physicalaspects of the diamond have been the subject of repeated inquiries,it cannot be said that the, results obtained are altogether satis-factory. Thus, the frequent twinning on the cube plane wouldseem t o negative the structural subsistence of a correspondingplaiie of symmetry, the effect of which would be to relegate thecrystal t o the tetrahedral class. This tetrahedral symmetry would,however, in turn imply electric polarity along the trigonal axes ;the recent exhaustive work of van der Veen,ll however, failed totrace any such polarity. The stereochemical elucidation of thediamond appears to have furnished a satisfactory answer to theseFIG.4.contradictions the cube planes of the structure are not planesof symmetry, nor are the trigonal axes polar, for althoughsuccessive octahedral planes of atoms are alternately spaced a tdistances in the ratio 1: 3, the structure is nevertheless identicalwhen viewed along the trigonal axes in opposite directions.Ziizc Blei~cbe,l3 ZnS.-The atomic arrangement in this mineral isprecisely analogous to that of the foregoing, and it is thereforeonly necessary t o suppose the quarter atoms on the cube cornersto be composed of zinc, whilst the central atoms are sulphur. Thestructure indicated in Fig. 4 is thus obtained. Although thearrangement of the material is obviously the same, the difference incomposition brings about a fundamental structural difference ascompared with the diamond, for successive octahedral planes areA.L. W. E. van cler Veen, Zeitsch. Kryst. Min., 1913, 51, 545.l2 P. P. Ewald, Ann. PSysik, 1914, Liv], 44, 257.J3 W. L. Bragg, Proc. Bop, Soc., 1914, [ A ] , 89, 468; A,, ii, l S l 246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.now strewn with zinc and with sulphur atoms respectively; thetrigonal axes are now polar, and the symmetry of the assemblagecorresponds exactly with that of the mineral. It will be seen thateach zinc atom is tetrahedrally surrounded by four sulphur atoms,and more distant’ly by twelve other zinc atoms. It must be addedthat a careful analysis of the original Laue radiograms nowcorroborates Bragg’s structure in every detail.12FZuorspur,l3 CaF,.-The structure of this substance has also becninvestigated by W.L. Bragg, and apparently with satisfactoryresults. The atomic arrangement advocated may again bevisualised by the construction adopt’ed for the diamond and zincblende. I n the latter assemblage, substitute F for S, and Ca forZn, so that each of the four occupied cubic cells corresponds witha group -CaF. I n order to make up an assemblage correspondingin composition with CaF,, it is obviously necessary t o allocate anFIG. 5. FIG. 6.additikal number of fluorine atoms; if each of the four emptycube cells of the diamond and zinc blende structures be now sup-posed to contain a centrally situated fluorine atom, the assemblageof Fig. 5 is finally obtained.The symmetry of the assemblagecorresponds with the holohedral cubic class, and is in agreementwith all available crystallographic knowledge.Pym’tes,l3 FeS,, and Hauem’te, MnS,.-The geometricalform and physical properties of these two isornorphous mineralsare so replete with items of interest as to warrant an expectationthat the underlying structure should also offer unique peculiarities.This expectation has been conspicuously realised, for Bragg’sanalysis, effected by the help of the X-ray spectrometer, proves theintimate atomic structure to be in accordance with one of theFedorov-Schonflies point systems, namely, the asymmorphoussystem ( 2 5 ) ~ ’ of Fedorov’s ~lassification.1~ Moreover, a detailedl4 E. 8. Fedorov, Zeitsch.Kryst. Min., 1914, 54, 163.IroMINERALOGICAL CHEMISTRY. 241analysis and comparison of the radiograms obtained by Ewaldserve to fix the relative spacing of the iron (or manganese) andsulphur atoms with great precision.It betrays a generalsimilarity to the structure adopted for fluorspar, but the follow-ing important difference must be noted : each sulphur atom is notsituated a t the centre of its cubic cell, but has been moved alongan appropriate cell diagonal away from an iron atom towards anunoccupied corney, so that its distance from the iron atom is aboutfour times its distance from the unoccupied corner. It will beobserved that the displacements of the sulphur atoms are notalong a series of parallel diagonals, but rather according to adefinite scheme in which the various diagonals are favoured inturn.The symmetry of the structure is in complete harmony withthat of the crystal. Preliminary experiments carried out withcrystals of hauerite also led to the same general conclusions.The publication of these results furnished Ewald 16 with an indis-pensable foundation for the exhaustive analysis of Laue’s radio-grams. This analysis proves the essential correctness of Bragg’sdeductions, the sole modification being that in hauerite the posi-tion of the sulphur atom is obtained by dividing the cube diagonalin the exact ratio 4: 1, whilst in pyrites the sulphur is a littlenearer to the metallic atom than Bragg supposed, the correspond-ing ratio being 7 : 2.It may be mentioned, in concluding this section.that a valuableappreciation of the recent advances in stereochemical crystallo-graphy has been contributed by Groth,lS who concludes that regu-larities, like the symmetrical environment of each sulphur atom inzinc blende by four zinc atoms, must be held to indicate that nosulphur atom is specifically united to any single zinc atom in thechemical sense, and it must therefore be inferred that chemicalmolecules do not exist in the crystalline condition. The writerbelieves this conclusion to bs not a little premature. Although thefrequent formation of crystalline double salts, like the alums,clearly proves that crystallisation is accompanied by a certainamount of pooling of chemical affinities, i t must nevertheless beapparent that t o deny the existence of the chemical molecule wouldopen up most extensive possibilities of isomeric change, optical in-versions, and so forth, whenever the crystalline structure is brokendown by dissolving or fusing the substance.Such changes havenever been observed. The reader need hardly be reminded thatX-ray methods of investigation are still in their infancy, and that,The structure is represented in Fig. 6 .l5 P. P. Ewald, Physikal. Zeitsch., 1914, 15, 399l6 P. Groth, Zeitsch. Kryst. Min., 1914, 54, 65 ; A . , ii, 719..248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.however remarkable the progress already made, it must be stronglyemphasised that all theoretical interpretations must be regarded asprovisional.Happily, the originality of the workers who aredevoting themselves t o the study of this new branch of investiga-tion is in itself a sufficient guarantee, not only t h a t steady pro-gress will be made, but also t’hat entirely new developnients maybe expected.Crystullo-chemical Analysis.The trustworthiness of Fedorov’s method of identifying a sub-stance by virtue of its characteristic crystalline form has been putt o a further searching test, with results that demonstrate itsextremely practical value to the chemist. The following two ex-amples taken from a brochure written by Fedorov17 will be enought o show that the method can be successfully applied even when theavailable amount of material will not admit of a chemical analysis.I n a research on the chemical processes that accompany theripening of seeds, N.R. Nedokuschaev was seriously impededowing t’o the small quantities of the products isolated. The latterhe eventually handed over t o M. B. Orelkin and G. Pigulevski,pupils of Professor Fedorov, in order to see whether crystalmeasurements would afford any clue to the identity of the sub-stances, and the crystal analysts succeeded in identifying asparagine, C4H,03N, ; allantoin, C4H&,N4 ; histidine, C,H,0,N3 ;arginine, C,H,,0,N4 ; and betaine, C,H,,O,N. Of these com-pounds, histidine was identified in the form of its hydrochlorideand betaine as platinichloride.The same chemical crystallographers rendered inestimable assist-ance t o A. A. Pomaski in a research on the teleutospores of therust fungus (Pucciuia graminis Persoon), and identified d-mannitol,C,H,(OH),, and ‘‘ vitaline.” The latter substance belongs to theclass of the crystalline albumens, and according t o Weyl has thecomposition C = 52.43, H= 7.12, N = 18.1, S = 0.55, 0 = 21.8 percent.Its molecular weight is unknown. The amount of vitalineplaced a t the crystallographers’ disposal was 0.05 gram, and wasfound t o be quite sufficient.It is evident that the method is destined to be of a special valueto the bio-chemist, and it is therefore desirable that every well-crystallised substance of complex chemical structure should begoniometrically measured, its geometrical form properly analysed,and its characteristic constants tabulated. It may be stated thatthe immense work connected with the tabulation of the thousandsof substances which have been measured and described by successivegenerations of crystallographers is drawing to a satisfactory corl-l7 “ Crystallochemiccd Analysis ” (Russian), 1914MINERALOGICAL CHEMISTRY.249clusion, the tables being already in the proof stage. A discussionof some of the points arising out of the study of these tables hasbeen recently given by Fedorov,ls and the quickest methods ofmeasuring a crystal and tracing its identity by means of the tableshas also been described by the creator of the method.19Crystal Symmetry and Molecular Symmetry.The exceedingly rapid development of stereochemical ideas sincethe enunciation of the tetrahedral hypothesis of carbon by van’tHoff and Le Be1 would lead one to suppose that the possibility ofthe existence of a close connexion between molecular and crystalsymmetry must have occurred to the minds of many workers.Asfar as published material goes, the credit of the first examinationof this subject appears to belong to the veteran mineralogistTschermak, who, in 1903, pointed out certain numerical regulari-ties, now known as “Tschermak’s rules,” that subsist between thegeneral composition of a substance and the form or symmetry ofthe crystal. Thus, the formulz Al,O,,NaNO,, Na10,,3H20, inwhich the number 3 constantly recurs, represent well-known casesof rhombohedra1 or trigonal crystals ; ZrSiO,,SnO,, tetragonal ;MgSnF6,6H,0, hexagonal; CBr,, cubic; and so on. Several con-tributions t o the same subject have been published during the lastten years, and have received due notice in these reports, so that i tonly remains t o give an account of some recent notable develop-ments.The general relationship between crystal symmetry and molecular symmetry has been discussed by Fedorov,20 who with allmodesty puts forward the conception of a crystal-molecule, consist-ing of 7% chemical molecules, where n = l in the exceedingly rarecase in which the symmetry of the chemical configuration corre-sponds exactly with the symmetry of the crystal.I f , on the otherhand, the molecule is completely asymmetric, and the crystal formis, say, rhombic sphenoidal, the number I I =4 ; more generally, ifp represents the “ symmetry magnitude ” of the crystal, m the sym-metry magnitude of the molecular configuration, then 11 =p/m.It will be observed that the possibility of the chemical symmetrybeing greater than the cryst.al symmetry is not considered ;Fedorov believes it t o be mathematically impossible, which is per-haps another way of stating that the assumption is contrary t o thedictates of common sense.It will be readily realised that in thosecases in which the symmetry of the chemical formula is incom-’8 E. S. Fedorov, Zeitsch. Kryst. Min., 1914, 53, 337.l9 Ibid., 1914, 54, 1 7 ; A . , ii. 718.2o Ibid., 1913, 52, 22; A,, 1913, ii, 305250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.patible with the observed symmetry of the crystal, there must bean error somewhere-if not in the crystal determination, then inthe chemical formula.One or two cases are discussed, andchemists are advised to set to work on the congenial task ofdevising new f ormulz.Any discussion of a chemical formula obviously implies, or leadsup to, a discussion of the valency, and, stereochemically, the sym-metry of the atom. The main result of Fedorov’s analysis is thatcarbon amongst the quadrivalent ele’ments, and aluminiumamongst the tervalent element-s, exhibit the clearest, although notperfect, crystallochemical evidences of a symmetrical dispositionof the chemical valencies. Those who peruse Fedorov’s paper willno doubt come across one or two statements of doubtful cogency;in particular, the reporter does not see why the bromine atom inCBr(C,H,), and ths hydrogen atom in CHI, are “ certainly devoidof a threefold axis of symmetry.”The same problem, a t least as far as carbon is concerned, hasbeen attacked by Wahl,21 who, with rare experimental skill, hasnot only succeeded in determining the crystal system of some fortycarbon compounds which are liquids or gases a t the ordinarytemperature, but also the system of crystallised argon and nitrogen !ThO determinations were, of course, carried out optically.Argonand nitrogen are optically isotropic, and presumably belong to thecubic system. I n the case of carbon compounds, there is hmoderately general agreement between the symmetq of the crystaland the symmetry of the molecular configuration; for example,both methane and its tetrasubstituted derivatives, CBr4, CI,,C(N02),, and CMe,, are cubic ; the disubstituted products, CH2Cl,,CH,Br2, CH212, are rhombic, and the trisubstituted derivative,iodoform, and also ethane are hexagonal.The author accordinglydraws the conclusion or “t,heory” that “the symmetry of thechemical molecule of a substance determines its crystal symmetry.”The author is aware that some of the compounds examined will notfit in with the theory unless the usual spacial formula= are arbi-trarily deformed to correspond with the observed determinations.For example, methyl chloride, bromide, and iodide are monoclinic.These irregularities the author seeks to explain by means of certainideas on the magnitude of atomic spheres of influence, but theseexplanations are, of course, only paraphrases of the anomalies,and do not in any way restore the generality of the theory.Avaluable research which bears on the subject is that of Drugman,22W. Wahl, Proc. Roy. Xoc., 1912, [ A ] , 87, 371 ; 1913, [ A ] , 88, 3 4 ; 1913, [ A ] ,89, 327; 1914, [ A ] , 90, 1 ; A . , 1912, ii, 1044; 1913, i, 693; 1913, ii, 1031 ;1914, ii, 348.J, Drugman, Zeitsch, Kqjst. Min., 1914, 53, 240 ; A . , i, 140MINERALOGICAL CHEMISTRY. 251who has made an extensive study of certain symmetrical dibasic,aliphatic acids. Thus, malonic, glutaric, dimethylmalonic, diethyl-malonic, b&dimethylglutariu, ad-dihydroxy-ad-dimethylglutaric,and n-pimelic acids should all presumably crystallise in the rhombicsystem.I n reality, however, the respective systems of crystallisa-tion are triclinic, monoclinic, tetragonal (trapezohedral), triclinic,monoclinic, triclinic, and monoclinic.Attention may here be drawn to a study25 of a suite of fourisomeric dinitrobenzoic acids, and also to an exhaustive examinationof a series of monosubstituted benzoic acids.24 Certain morphotropicrelationships are discussed in the latter paper, but a careful perusalof the memoir shows that the allocation of indices is of a pro-nounced subjective character, and is directly responsible for someof the alleged morphotropic similarities.The Barlow-Pope Theory.An interesting and illuminating discussion on its merits andshortcomings has taken place between the authors of the theoryand Richsrds.25 The chief bone of contention is the question ast o the comprelssibility of atoms.It is well known that the Ameri-can chemist has from time t o time adduced a large amount ofexperimental evidence in f avour of atomic compressibility,26 whilston the othelr hand the propounders of the theory would seem tofind no difficulty in elucidating crystal structure without havingrecourse to any such assumption. Perhaps the most importantpoint made by Richards is the proof that Le Bas’ interpretationof a volume relationship, C =4H, is inconclusive, since alternativeassumptions that C=2H or 3H or 5H will fit in equally well withthe known molecular volumes of the paraffin hydrocarbons con-cerned.The theory has also been described by Pope in his PresidentialAddress to Section B a t the Australian meeting of the BritishAssociation ; although no new matter is introduced, this contribu-tion will be found t o be a useful outline of the present positionheld by the propounders of the theory.The practical development of the theory has been actively prose-cuted during the year in a series of papers constituting numbersV-VII of ‘‘ Morphological Studies of Benzene Derivatives,” inwhich an enormous number of new crystal measurements are23 R.Gossner, Zzitseh. Kryst. Min., 1914, 53, 489; A . , i, 406.25 T. W. Richards, J. Amer. Chem. Soc., 1913, 35, 381; 1914, 36, 1686;26 T. W. Richards, ibid., 1914, 36, 2417.H. Steinmetz, ibid., 463 ; A . , i, 405.W. Rarlow and W.J. Pope, ibid., 1675, 1694 ; A., 1913, ii, 483 ; 1914, ii, 719252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.described and discussed in t’he light of the t’heory.27 I n additiont o crystal measurements, the seventh memoir contains an accountof observat,ions on the principal magnetic directions of a numberof monoclinic crystals, which were carried out in the hope that theymight provide critical criteria for the correct setting of crystals.If by the term “correct setting” the authors imply the same mean-ing as Fedorov, it’ would seem that they have omitted to take intoconsideration the fact that magnetic induction is an ellipsoidalproperty, and on that account is entirely useless for the end inview. The authors’ general conclusion is that their work providesa verification of the Barlow-Pope conception of valency volume.Thermal Studies of Mirberals.Considecrabla developments have taken place during the year inthe study of the equilibrium conditions of mineral mixtures, andas marked progress has to be noted both in the methods of workingand in the actual results obtained, it will be convenient to dividethe short r6sum6 into two sections.Methods.Whenever feasible, i t is bed to measure temperatures by meansof a platinum-platinum-rhodium thermo-element.The methods ofconstructing, calibrating, and using this invaluable form of thermo-meter have been recently described in a series of papers dealingwith calorimeters and thermo-electric instruments of precision byWhite.28 The experimental ’error varieB with the amount ofmaterial taken and the character of the contact between the elementand the mineral charge.With a careful worker the error may fallas low as +2O. The limit of applicability appears to lie a t about1600O (the melting point of platinum is 1755O). F o r higher tem-peratures recourse must be, had to far less accurate methods; it istherefore fortunate that the great majority of minerals melt below1600°, the orly exceptions being a few oxides and sulphides whichhave long been known to be highly refractory materials.Since the direct observation of the melting point, as, for example,by means of the Doelter heating-microscope, must always remain acumbrous and quite untrustworthy procedure owing t o the diffi-culty of seeing whether a viscous mass is solid o r liquid, it hasbeen necessary t o devise indirect or non-visual methods.The earlier27 H. E. Armstrong,’.R. T. Colgate, and E. H. Rodd, Proc. Roy. Soc., 1914, [ A ] ,90, 111 ; C. S. Mummery, ibid., 455 ; H. E. ArmArong and E. H. Rodd, ibid.,463 ; A., ii, 443 ; i, 1062 ; ii, 768.28 W. P. White, J. Ainer. Ckem, Soc., 1914, 36, 1856, 1868, 2292, 2313 ; A , ,ii, 767MINERALOGlCAL CHEMISTRY. 253method employed by the American workers was to raise the tem-perature of the crucible a t a regular rate by means of an electricsource of heat, and plot temperature-time curves; any absorption ofheat, whether due to liquefaction or t o a polymorphous change,brings about a decrease in the rate of the rise of temperature. Itmust be noted that the converse method, namely, that of coolingcurves, is untrustworthy owing to supercooling effects.A second andlater method, and one which is now extensively employed, is that of‘‘ quenching.” 29 The crucible is kept a t a constant temperaturefor an hour or so, and then suddenly quenched by dropping i t intoa dish of mercury. This sudden cooling transforms any moltenmaterial into glass, the presence of which is immediately recognisedby a subsequent examination of the product under the polarisingmicroscope. By trying successive temperatures a t 5 O or loointervals, the temperature a t which glass is first formed is thusdiscovered. By trying higher temperatures, the point may then bedetermined a t which the whole of the crucible contents, afterquenching, proves t o take the form of glass.The two points thusdiscovered are the solidus and liquidus temperatures for the givenmixture. It is obvious that the microscopic examination also leadsto the identification of the various crystalline phases which are inequilibrium with the fusion.Another point that has been subjected to a searching examina-tion is the all-important question of the condition of the materialunder investigation. It goes without saying that this materialshould be chemically pure ; t3he silicates employed have thereforeto be made artificially from pure silica and metallic oxides. Now,although i t is an easy matter to obtain a product of a definitecomposition, it is extremely hard to ensure that i t shall consist ofa single chemical species.Suppose, for example, i t is desired t oprepare a series of pure magnesia-lime pyroxenes ranging in com-position between diopside, CaXlg(SiO,),, and clino-enstatite,MgSiO,. It is not’ sumcient to fuse together the correct propor-tions of lime, magnesia, and silica and allow the mass to cool, forin systems which are characterised by the separation of mixedcrystals, the liquidus has not the same composition as the solidus,and crystallisation is accompanied by a gradual impoverishmentof the liquid portion in one or more of the components. It isimpossible t o keep down the rate of cooling to such an extent ast o allow a perfect attainment of true equilibrium conditions.Theoretica,lly, the first crop of mixed crystals should redissolve asthe temperature is lowered, if solid and liquid were in perfectequilibrium ; in practice, the final crystalline product must always?Y N.1,. Bowen, Amer. J. Xci., 1914, [iv], 38, 207 ; A . , ii, 772254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.be extremely variable from point to point throughout the mass.The obtainment of homogeneous equilibrium material is of greatimportance, especially when it is t o be used for subsequentresearches. The only way to obtain it is to quench the fusedpyroxene to a homogeneous glass, and then maintain this glassfor some time a t a temperature which is just a little below the pointat which it commences to liquefy. The homogeneous glass thencrystallises to a conglomerate of homogeneous mixed crystals.Results.Binary System,30 MgO-SO,.-This system, which has been care-fully determined by Bowen and Andersen, is characterised by theappearance of two well-defined compounds-the orthosilicate for-sterite, Mg,SiO,, and the metasilicate clino-enstatite, MgSiO,.Thelatter substance was on a previous occasion shown t o occur in fourpolymorphous forms, t o which a fifth (“a-MgSiOS”) was addedsomewhat later; it is now pointed out that this fifth form isoptically identical with forsterite, and owes its origin t o the disso-ciation of clino-enstatite a t its reputed melting point into the ortho-silicate and free silica : 2MgSi0, Z Mg,SiO, + SiO,. The mainfeatures of the system may be epitomised as follows: Magnesia(periclase) has a very high melting point, perhaps 2800°, and formsan eutectic (1850O) with forsterite, which itself melts at 1890O.There is no eutectic between forsterite and clino-enstatite; theeutectic between the latter and cristobalite (silica) lies at 1543O.C’ristobalite melts at 1 6 2 5 O olr higher.Ternary System,29 Diopside-Forst erit e-Silica.-Although thescope of this system only extends over three-eighk of the systemCa0-Mg0-Si0, the most important portion of the latter is reallyincluded, f o r the part under consideration embraces the pyroxeneand olivine families of minerals.The quenching method wasemployed, the material used being a previously prepared series oflime-magnesia metasilicates to which appropriate amounts of pureforsterite or silica were added.The exact temperature needed forcomplete liquefaction and also the identity of the phase which wasthe last to disappear (or, alternatively, the first to reappear whenthe temperature was slightly lowered) were determined for eachmixture. Such resulh are best illustrated by a spa‘ce model con-structed on a triangular base so as to allow of an exact representa-tion of the relative concentration of the three components, thevertical dimension being reserved for temperature. In a case likethe present, in which the three components do not form a con-tinuous series of solid solutions, the top of the model (see Fig. 7)Do N. L. Bowen and 0. Andersen, Amer. J. Sci., 1914, [iv], 37, 487 ; A . , ii, 562MINERALOGICAL CHEMISTRY.255will be divided by boundary curves into a number of fields orareas, each representing the fusion surface of a solid phase. Inthe case in point there are four such fields: forsterite, pyroxene&,cristobalite, and tridymite, the latter area being very circum-scribed. Two important points may be noticed with regard to thepyroxenes : (1) the area extends uninterruptedly from diopsideacross the whole of the diagram, thus indicating the existence of acomplete series of mixed crystals ranging from CaMg(SiO,), toMgSiO, ; (2) the boundary line, forsterite-pyroxene, crosses thedotted line, MgSi0,-CaMg( SiO,),, a t a point corresponding withabout 70 per cent. of diopside, from which it follows that allmetasilicate fusions, excepting those very rich in lime, will a t thecommencement of crystallisation deposit forsterite (olivine).Pyro-xenes will only appear Then the silica-enrichment of the liquidresidue brings its composition to the f orsterite-pyroxene boundary.PIG. 7.CaMg( SiO&Mg,SiO, MgSiO, Sio,If the cooling is sufficiently slow, the originally deposited f orsteritewill then commence to dissolve in the silica originally liberated;if, however, the rate of cooling does not admit of the attainmentof equilibrium, the f orsterite will remain permanently, and theexcess of silica will eventually crystallise out. We have here anelegant explanation of two petrological enigmas: (1) the not infre-quent occurrence of olivine in the presence of free quartz; (2) theunmistakable signs in many rocks of a gradual resorption of olivinewith the production of pyroxene.Again, the zonal developmentof pyroxenes generally shows a preponderance of magnesia in thenucleus. This is what would be expected from Bowen’s work,since the magnesia pyroxenes have higher melting points than thelime pyroxenes. The paper includes amongst other importantmatters an extensive series of optical determinations of the wholeseries of pure lime-magnesia pyroxenes256 ANNUAL REPORTS ON THE PROGRESS OF’ CHEMISTRYPolymorphism.Since it is generally agreed that two or more materials of thesame percentage composition must always be regarded as ( ( poly-morphous modifications ” until definite experimental evidence neces-sitates the employment of different formulae, it is obvious that theterm polymorphism can only be defined in negative chemical terms.The history of chemist’ry abounds with numerous proofs that thepolymorphs of yesterday are the isomerides of to-day: as chemicalmeans of detecting differences of structure have become more andmore refined the more imposing has become the list of instancesin which polymorphous modifications have finally received the hall-mark of chemical respectability.Especially resisting to this civilis-ing influence, howe’ver, are the old stack cases of polymorphismin which the physical differences are satisfactorily interpreted asmerely due to a different space-lattice arrangement of the samechemical molecule. The interpretation is sufficient because thereis no evidence of any persistence of the characteristic physicaldifferences when once the c7ystal structure is broken down ; i t musthold the field until such time as chemical differences have beenproved by tests or reactions applied in the crystalline state.It is,however, very questionable whether the chemistry of the solidcondition has yet seen the light of day; if in truth it has, the infantmust indeed be preternaturally silent.One of the consequences of the rapid growth of physical chemistryhas been the increasing tendency t o apply physical evidence as ameans of attacking such chemical problems as present insuperableexperimental difficulties when approached in more orthodox ways.I n the abstract, this is all to the good, but in practice there mustalways remain a doubt as to how far any such physical considera-tions have any real chemical bearing.This remark appears to beparticularly relevant to Tammann’s (‘ atomic theory of poly-morphism.” 31 Tammann believes that certain cases of polymorph-ism are to be regarded as simply due to a space lattice rearrange-ment, whilst others result from chemical polymerism. The criterionto be applied in the discrimination between the two categories isto study the stability relationships of the polymorphs over anextended range of temperature and pressure, and in this waydiscover whether the two forms can coexist in stable equilibriumunder varying conditions. According t o Tarnmann, stable co-existence implies polymerism, whilst cases, in which one form isentirely metastable with regard to the other, are deemed to beinstances of a space lattice rearrangement.The results of an31 G . Tammann, Zeitsch. physikal. Chem., 1913, 82, 172 ; A., 1913, ii, 193MINERALOGICAL CHEMISTRY. 257examination of some thirty organic compounds lead Tninmaniito the conclusion that most cases of polymorphism belong t o thelatter category. Ice, however, is held to be a notable exception.Although the five forms of ice, which are now known as a resultof the careful work of Bridgman,32 would be regarded as examplesof polymerism, a sixth form (the so-called modification III’), whichTammann has recently added t o the list,33 is, according to thesame authority, t o be regarded as a space lattice rearrangement ofthe form 111.Bridgmaii34 is, however, of the opinion that 111’is not merely metastable, but has no existence whatever. Withregard to the validity of his physical criterion, Tammann adducescertain thermodynamical considerations in its support, but Smits 35is of the opinion that the process of reasoning amounts to puttinga preconceived idea into the thermodynamica1 machine and subse-quently extracting the same after a respectful interval.Of an entirely different nature is Smits’s 36 theory of dynamicpolymorphism (or ‘‘ allotropy ”). Polymorphism is held to be initself a definite indication of the existence of more t’han onechemical species, and the two (or more) isomerides are supposedto co-exist both in the fused substance and in the various poly-morphous modifications in a state of dynamic equilibrium.If thetwo forms are denoted by A and B, then fall of temperature isaccompanied by a steady shifting of the equilibrium in the sense,A -+B. The transition temperature is held t o be the point a twhich one crystal structure will not allow of any further change,A -+B; accordingly, a new space lattice structure of a moreaccomodating nature makes its appearance. By way of criticism,i t is only necessary to recall and contrast the perfect limpidity ofall polymorplious modifications with the turbidity that invariablyaccompanies any serious contarnination of any crystalline substancewith another (even if the contamination be isomorphous), t o seethat Smits’s theory can scarcely commend itself to the pure crys-tallographer; but, however this may be, it must be stated thatthe theory has served to interpret a considerable number of curiousfacts. The theory can be invoked,37 for example, in order t ointerpret the fact that the melting point of rhombic sulphur varieswith the temperature a t which the specimen has been previouslymaintained.It is true that the observed temperature difference52 P. B. I3ridgni;in, Proc. Asizer. Acnd., 1912, 47, 441, 558 ; Zeitsch. anor!].3J G. Tamm:inn, Zeitsch.physikcc1. Chem., 1913, 84, 257; A . , 1913, ii, 935.3-1 P. R. Bridgman, ibid., 1914, 86, 513 ; A., ii, 254.85 A. Smits, ibid., 1913, 82, 657 ; 84, 250; A , , 1913, ii, 393, 933,s6 Ibid., 1911, 76, 421, and various subsequent papers.::7 Idem., ibid., 1913, 83, 221 ; A., 1913, ii, 499.Chem., 1912, 77, 377 ; A , , 1913, ii, 39.REP.-VOL. XI.258 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.only amounts t o about 0*5O, but in the case of the polymorphousforms of silica, to be described presently, certain temperaturefluctuations have been observed, according to circumstances, in thevalues of one of the t'ransition points, and these variations are notso open to doubt, a t any rate on the score of minuteness.Fenner's Work o n Quartz, Tridymite, and Cristobalite.3~--Thetransition temperatures and general conditions of stability of thenumerous modifications of silica are indicated in Fig. 8, in whichthe experimentally determined temperatures are plotted againsttheoretical (imaginary) vapour pressures, all that.is implicd beingthat the curves express the general experimental work. It will beobserved that each mineral species exists in a t least two modifica-FIG. 8.Ptions (a and P ) . Now Fenner found the change u Z fl to differfrom a change of one mineral species into anot'her in the followingimportant particular : the former takes place rapidly immediatelya transition temperature is overstepped, whereas the latter changeis excessively slow. Quartz, tridymite, and cristobalite can co-existtogether without undergoing any serious transformation a t all,except a t very high temperatures; and in order t o determine thesetransition fxmperatures it was found necessary t o add a smallamount of sodium tungstate, which apparently exercises a cata-lytic function.The same stubborn persistence of metastable phasesis also characteristic of the devitrification of silica glass, and evenin the presencs of sodium tungstate the first crystallised product isC. N. Penner, Amer. J. Xci., 1913, [iv], 36, 331MINERALOGICAL CHEMISTRY. 259generally a metastable one. Fenner is therefore driven to theconclusion that the extreme slowness of the changes, quartztridymite t cristobalite, demands the assumption that each is adifferent chemical species. It is then possible t o refer thesluggishness of each transformation t o the time demanded by pro-cesses of polymerisation and depolymerisation. On the other hand,the two kinds of quartz (a and /3) are supposed to be composedof the same chemical molecules, the transformation being due toa slight modification of the crystal lattice; and the same is truefor the three tridymites (a, P1 and P2).The cristobalites, however,exhibit the iollowing curious behaviour : the transformation pointa Z fl is extremely variable and depends entirely on the previoushistory of the specimen. The higher the temperature a t whichi t was originally obtained from amorphous silica, the higher isthe observed transition temperature ; a-cristobalite changes intoP-cristobalite a t temperatures which range regularly between thelimits 220--274°, according as the original temperature of itsformation had a low or high value between the limits 1050-1600O.Fenner holds that this behaviour points to the co-existence incristobalite of two kinds of material in the sense of Smits’s theory,the idea being that if the equilibrium condition between thedynamic isomerides responds very slowly to a change of temperature,then the relative amounts in a given specimen will depend on itspast thermal history.The inimpretation of the quartz and cristobalite inter-relation-ships, based on the work of Endell and Riecke,39 has been indepen-dently undertaken by Smits and EndelL40 They conclude that thebehaviour of a- and P-quartz and cristobalite is referable t o theexistence of two kinds of chemical molecules, the relative amountsof which can be indicated by arranging the minerals in the order :a-cristobalite, P-cristobalite, P-quartz, a-quartz.Relationships like those subsisting between a- and /3-quartz, inwhich the two forms are extremely similar in optical propertiesand apparently only differ in symmetry, have long been knownamongst laboratory products. An excellent example of this‘‘ polysymmetry ” has been described during the present year.*lAbove a temperature of 1 8 O , butyranilide crystallises in the rhombicsystem, but the crystals are pseudotetragonal.On idlowing thespecimen to remain, a gradual equalisation of the angles takesplace, so that after a period of eighty-five days, the crystals havebecome truly tetragonal. On raising the temperature, the reverse39 I<. Endell and R. Riecke, Zcitsch. anorg. Clzem., 1912, 79, 239 ; A., 1913,ii, 134.4o A.Smits and K. Endell, ibid., 1913, 80, 176 ; A., 1913, ii, 318.41 C. T. R. Wilson, Proc. Roy. Xoc., 1914, [A], 90, 169.s 260 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.progress gradually sets in. The tetragonal form may be obtaineddirectly by keeping the crystallisation solution below loo.The work described in a previous Eeport 42 on the formation andstability relationship of pyrites and marcasite, FeS,, and zincblende and wurtzite, ZnS, has been considerably extcnded.43 Themethod employed in the estimation of the r e l a h e amounts ofpyrites and marcasite was that originally due to Stokes; thismethod has been carefully examined, and found t o be entirelytrustworthy when certain precautions are observed.44Anisotropic Liquids or '( Liquid Crystals."The important observation of Reinitzer that cholesteryl benzoatemelts at 140° to form a turbid, doubly refracting liquid, which,a t a temperature of 1 7 9 O , becomes clear and singly refracting,prompted Lehmann to undertake an extensive microscopic studyof the substance, Gattermann's syntheses of pazoxy-anisole and-phenetole, as also the preparation of several other compounds byother workers, soon led to a considerable augmentation of theavailable experimental material, and i t was not long beforeLehmann drew the conclusioa that such turbid liquid phases %reta be regarded as aggregates of "liquid crystals." It is well knownthat suggestions that the liquids are really emulsions were soonproved to be untenable.One cannot but infer from a close perusal both of the earlyand of the most recent books and memoirs, which have been SDlavishly written by Lehmann, that he has always been at least asmuch swayed by certain, peculiar theoretical considerations, asby his actual observations. If the term crystal connotes a homo-geneous mass of material, arranged on a space-lattice pattern, itis obviously no light matter to put a fluid mass to the proof oEexperiment; for many of the tests t o which a crystalline mediumcharacteristically responds are wholly or partly inapplicable, owingto this very fluidity : any att'empts to investigate elasticity,cohesion, or cleavage are quite unthinkable.The general opticalproperties, on the other hand, are certainly more hopeful, and i tis in the field of microscopic work that Lehmann has made mostvaluable observations.At the same time, however, it must beemphasised that' the possession of properties like double refractionand dichroism does not prove the liquid substances t o be crystalline;it merely indicates the existence of a definite regularity of struc-42 Aim. Rcpo~t; 1912, 266.43 E. T. Allen, J. L. Crenshaw, and H. E. Merwin, Amer. J. Xci., 1914, [iv], 88,44 E. T Allen a d ,J. L. Creiishaw, ibid., 371 ; A., ii, 850.393 ; A . , ii, 850MINERALOGICAL CHEMISTRY. 261ture of some kind or other, and exactly t o that extent, and nofurther, supports an analogy between them and crystals. It maybe noted that Lehmann, who is naturally never more clear-sightedthan when he is criticising the views of others, is himself fullyaware that optical evidence can never be regarded as complete:apropos, Vorlander’s assertion that his viscous substances must beregarded as uniaxial crystals because they exhibit a perfect uniaxialinterference figure, Lehmann states 45 : ( ( such a liquid mass canonly be regarded as a uniaxial liquid crystal provided it stroveduring its growth t o attain a square or six-sided outline.” Now,as a matter of fact, i t is just this evidence that one seeks for invain in Lehmann’s own published writings.Although the dia-grammatic drawings originally given for ammonium oleste areclearly hexagonal bipyramids,46 it is, nevertheless, stated in thetext that the outlines are really circular (‘owing to surfacetension,” and this admission is, of course, fully borne out by tlisphotographic reproductions.I n Lehmann’s latest book 45 thediagram no longer indicates any hexagonal character, whilst in aquite recent memoir47 there is even a mention of the form beingthat of a tetragonal bipyramid. Perhaps the clearest geometricalshapes of all are shown by Vorlander’s p-azoxybenzoic ester ; hiiteven in this case, as far as one can judge from a photograph, thcelongated shapes are due to a linear aggregation of more or lessglobular individuals, producing a segmentation effect.The cubic modification of silver iodide occupies an altogetlierexceptional position in the history of liquid crystals. It is onlyin recent years45 that Lehmann has given a new interpretatioiiof his early work on this substance and has claimed it’ t o be thefirst, known example of liquid crystals-because (‘ i t is impossibleby mechanical means t o prove the existence of an elasticity limit,”which means that silver iodide a t high temperatures becomes sosoft that it can no longer be regarded as a solid.Some remarlr-able researches on this point have been published during the year.48It has been shown that if every precaution as to chemical purityis empIoyed in the preparation and subsequent handling of tliesubstance, i t is much harder a t 550°, that is, 2 O below its meltingpoint, than is yellow phosphorus at the ordinary temperature.The addition of a small quantity of ordinary silver iodide immenselyincreases its plasticity.Since similar results were obtained by thesame authors with silver chloride and bromide, as well as with thehaloid salts of thsllium,49 it mnst be concluded that all these sub-45 ‘( Die neue Welt dei flnssigen Iiiistalle,” 1911. 41j ‘‘ Fiussige Kiistalle,” 1904.47 0. Lehmlarin, Zcitsch. Krgst. Min., 1913, 52, 597.48 C. Tubandt &d E. Loren;?, Zeitsch. physikal. Chem.) 1914, 87, 527 ; A , , ii, 516.49 €I. Stoltzenberg aLd M. E. Huth, ibid., 1910, 71, 641 ; A , , 1910, ii, 295262 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.stances must be definitely deleted from the list of liquid crystals.It must here be noted that t’he real point a t issue! is not so muchwhether any particular “ solid,” crystalline substance, say, silve’riodide, is so soft that i t would be a misnomer to term it a solid-a decision in either sense would not be particularly momentous-but rather whether the turbid, doubly refracting liquids arerestricted t o organic compounds of some molecular complexity, orwhether representatives are also to be found among simple binarycompounds.This is, indeed, a question of some Lheoreticalimportance.Enough has been said t o indicate that the use of the term liquidcrystal was quite premature from the outset. Some recent workon the geometrical form of ammonium oleate and pazoxybenzoicester has led the authors5O t o the conclusion that the shapes haveno similasity whatever with crystal forms, but are figures of revolu-tion of extraordinary complexity.Again, with regard t o theoptical properties of the more mobile substances,61 which, of course,cannot be said t o have any shape, it has been found that there isa continuous internal movement even in the smallest discreteglobule that can be isolated f o r purposes of observation. Themovement increases in intensity as the temperature is raised, anddoes not appear t o have any definitely regular character. Thecomposite nature of such globules was, of course, recognised byLehmann, who has frequently been compelled t o point out thata globule is not a liquid crystal, but an aggregate of liquidcrystals. It will be realised how impossible i t is to substantiatethe crystal character of such unpromising material.Homogeneous masses of material, suitable in every way forexperiments of some precision, first became available as a result ofVorlander’s 52 numerous synt’heses of complex aromatic derivatives,which, when melted on a glass slide, with or without a cover slip,yield a clear mass of doubly refracting liquid.When viewed inconvergent light there results in every case a normal uniaxial inter-ference figure with ail extraordinarily perfect definition ; moreover,if the subst-ance has an enantiomorphous molecular configuration,the interference figure shows rotatory polarisation. I n thicknessesgreater than 0.3 mm. the masses tend t o be slightly turbid.The values of the two indices of refraction E. and w have beendetermined with great accuracy.63 The fact that the existence of50 G.Friedel and 3’. Grandjean, Bdl. Sbc. f m i z c . Alin., 1910, 33, 192, 409:466 :A . , 1910, ii, 809, 1018.51 C. Manguin, Compt. ~ c n d . , 1912, 154, 1359; A., 1912, ii, 630.52 D. Vorlander, Ber., 1908, 41, 2033 ; A . , 1908, i, 641.5 j Aim. Beport, 1910, 11.“ KristallinischfliisvigeSubstanzen,” 1908MINERALOGICAL CHEMISTRY. 263biaxial liquid crystals has never been established whilst some fiftycompounds are definitely known to be uniaxial,5* is of superlativeimportance, inasmuch as it presents a statistical proof that thestructure is not crystalline (the proof is really very strong, sincenearly all chemical substances, having a complex chemical structure,crystallise in biaxial systems). The whole of ths firmly estab-lished properties, dichroism and the invariable straight extinctionwhen the “ c r y ~ t a l ’ ~ is resting on a “prism” face, the apparentabsence of double refraction in parallel light, and the perfectuniaxial figure in convergent light, when the (‘ crystal ” is restingon its base,” are in complete harmony with a structure analogousto that of an even-grained piece of wood.These considerations ledBose t o advance the “swarm theory,” which has dominated thework of the last few years.Bose’s Swarm Theory.65I n all theoretical discussions of the molecular theory of liquids i tis presupposed f o r purposes of simplicity that the molecule is spheri-cal. This supposition can, of course, only be true for liquefiedmonatomic elements; it can scarcely hold for a molecule like anis-aldazine, ~~eQ*C,H,*CH:N*N:CH*C,H,.QMe. If two or moreelongated molecules approach each other so closely that the meandistances of their centres of gravity are less than half ths lengthof the molecule, all free rotation must cease except about the direc-tion of elongation, and a stable tendency towards a parallelarrangement may set in.Now a large bundle o r swarm of parallelmolecules in a perfectly fluid condition and without any suspicionof a space-lattice arrangement will evidently possess the symmetryof a figure of rotation, and optically should behave as a uniaxialcrystal. Each swarm or homogeneous tract (“ liquid crystal ”) willbe quite clear and transparent, the turbidity of a large mass ofliquid being simply due to the reflection and diffusion of light a t themutual boundaries of the swarms.The average size of the swarmdecreases on heating; the point a t which the swarms become smallerthan the wavelength of light is the clearing point. Above thistemperature the liquid is to all intents and purposes singly refract-ing. A rough idea of the stiructures of isotropic and anisotropicliquids will be gained from Fig. 9, in which a is meant to illustratethe state of affairs in the ordinary isotropic liquid, which on coolingpasses into the swarms of parallel molecules shown in 6 ; the optical54 I). VorlZiuder, Physiknl. Zeitsch., 1914, 15, 141.55 E. Rose, ibicl., 1907, 8, 347, 513; A., 1907, ii, 443: ibid., 1908, 9, 708 ;A., 1908, ii, 1017264 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.behaviour of a single swarm, as exemplified by Vorlander’s viscoussubstance, is shown a t c.General Evidence in Support of the Theory.-The theory is ingood accord with all the general physico-chemical properties.Tobegin with, the change, crystal + anisotropic liquid, is not onlyquite sharp, but is also accompanied by a considerable absorptionof heat (about 20 calories). On the other hand, the change, aniso-tropic liquid + isotropic liquid, is not only chaxacterised by a lowheat absorption (about 1 calorie), but also appears to be a gradualprocess extending over one or two degrees of temperature.* Thisimportant fact has been brought out by Bose’s visconietric work.5GI n the case of anisaldazine the viscosity of the isotropic liquidincreases quite normally with the fall of temperature to the pointof turbidity, and then decreases very sharply to a minimum a t 2 Obelow the clearing or turbidity point.The viscosity then begins t osuffer the normal increase with fall of temperature, but it does notsucceed in attaining anything like the value enjoyed by the iso-FIG. 9.( a ) ( b ) (4tropic liquid. The lower value of the viscosity of the anisotropicliquid, as compared with the isotropic liquid, constitutes the so-called“ viscosity anomaly.” Its interpretation was given by Bose 57 ona kinetic basis. I f the form of the molecule be taken to be thatof an elongated ellipsoid of rotation, the viscosity of a swarm cantheoretically sink to two-thirds the value of the viscosity of the samesubstance in the isotropic condition; further, the supposition of .athree axial ellipsoid could account for even lower values.The ratioof the viscosities, anisotropic : isotropic is 0.65 for anisaldazine.It has also been found that the change, isotropic-+- anisotropic isalways accompanied by a moderate increase of density, as might beexpected from the closer packing that is obviously compatible withtl10 parallel arrangement of e810ngatred molecules.* The crystalline nature of anisotropic liquids was accepted by Roozeboom, whoaccordingly regarded the clearing point as the true melting point, the point a twhich the solid crystal melts to give the anisotropic liquid being regarded as apolymorphous transition point. This decision niust now be reversed ; a t any rate, itis more consequent to regard Roozeboom’s ‘( transition point ” as the true meltingpoint.E. Bose and F. Conrat, Physikal. Zcitsch,., 1908, 9, 169 ; A . , 1908, ii, 258.57 E. Bose, ibid., 1909, 10, 230 ; A , , 1909, ii, 383MINERALOGICAL CHEMISTRY. 265Magneto-optical Researches.-The investigation of the opticalbehaviour of anisotropic liquids under the influence of an electro-magnetic field has attracted the attention of several workers, andthe results are regarded by some, including Nernst,58 as affordinga decisive proof of the correctness of the swarm theory.It was early observed by Lehniann that a magnetic field has aclearing effect on droplets of p-azoxyanisole. Bose 59 investigatedthe effect on relatively large masses of liquid; with anisaldazine thOeffect begins with the application of 600 Gauss units of force, and,by means of a few thousand units, layers up to 4 mm. are imme-diately cleared when the direction of vision is along the lines offorce. On turning off the current, the mass immediately becomesturbid. Similar results were obtained with p-azoxy-anisole and-phenetole.The work was carried a step forward by Mauguin,60 who showedthat the very mobile p-azoxyphenetole may be obtained in clearmasses provided that both slide and cover slip are thoroughlycleansed with hotl sulphuric acid, distilled water, and ether; sucha preparation gives a normal uniaxial figure. The same substancewas then investigated under the action of a magnetic field, and thefollowing three fundamentally important observations were made :(1) layers up t o 2 mm. may be rendered quite clear and transparent,no matter whether viewed along or across the lines of force;(2) when exaniined between crossed nicols, the behaviour is in everyrespect analogous t o that of a uniaxial crystal-uniform darknesswhen viewed along the lines of force in parallel light and a perfect,uniaxial figure in convergent light'; normal extinction in fourpositions when viewed across the lines of force. The double refrac-tion is strong, and increases up t o the application of 5000 Gaussunits, and then remains constant up t o 7000; (3) when a homo-geneous film between slide and cover slip, as in Fig. 9c, is subjectedt o the action of a transverse magnetic field, the optic axis isgradually deflected away in the plane containing the lines of force.811 releasing the force, the optic axis iminediately returns t o thenormal position. Similar results, although not quite so complete,were independently obt'ained by Wartenberg 61 f o r both pazoxy-anisole and -phenetole; the double refraction of the latter wasfound t o be by far the stronger.T. V. BARKER.58 I!'. Nern>t, Zeitsch. Elektrochem., 1910, 16, 702.5g F,. Ijose, P?iysik-aZ. Zeeitsch., 1911, 12, 60 ; A . , 1911, ii, 184.C. Maugnin, Compt. rend., 1911, 152, 1680.H. v. Warteaberg, PhysiknZ. Zciitsch., 1911, 12 837, 1230 ; A . , 1911, ii, 952 ;See also ref. 51.1912, ii, 112

ISSN:0365-6217    

DOI:10.1039/AR9141100238

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

RADIOACTIVITY.The Atomic Weight of Lead.THE theoretical prediction that the atomic weight of lead fromradioactive minerals should differ from 207.1, the internationalfigure, that from uranium minerals tending towards the number206, and that from thorium minerals towards the number 208,lhas now been examined experimentally by several observers. Theresults obtained, although in all cases as yet of a preliminarycharacter only, show clearly that the atomic weight of lead fromradioactive minerals differs from the international value and varieswith the character of the mineral from which the lead is derived.I n the first results to be published, the mineral examined wasCeylon thorite,2 which is uniquely suitable for the investigation ofthe question, as regards thorium, since the ratio of uranium t othorium is exceptionally low, and the amount of lead is so smallthat it may well be all of radioactive origin. The thorium contentis about 55 per cent., the uranium content between 1 and 2 percent., and the lead about 0.4 per cent.If the law of the conservation of mass held during radioactivechanges, and the rigid correctness of this assumption is now opent o doubt (p.271), if all the lead in the mineral were of radio-active origin, and if the lead derived both from the thorium andthe uranium were entirely stable and accumulated linearly withthe lapse of time, it is to be expected that the atomic weight ofthe lead from Ceylon thorite should be rather more than one unithigher than the international figure.The rate of change ofuranium is probably between 3 and 2.5 times that of thorium, sothat, on the above assumption, the lead should be derived at leastten parts from thorium to each part from uranium. The calcu-lated atomic weight of the former is 208.4, and of the latter 206.0,Ann. Report, 1913, 269.F. Soddy and H. Hyman, T., 1914, 105, 1402. This paper was read on May7th: 1914, and an abstract appeared in the Morning Post 011 the following day, andin the Proceedings on May 18th, 1914.esRADIOACTIVITY. 261since they are derived from thorium, 232.4, and radium, 226.0,respectively, by the loss of six and five atoms of helium. Thecalculated atomic weight of the thorite lead should therefore beabout 208.2.I n the experimental work, a kilogram of the mineral was workedup, and only 1.2 grams of purified lead chloride were finally avail-able.It was purified chiefly by precipitation as sulphate and assulphide and by crystallisation as iodide, and its atomic weightwas estimated purely relatively against that of ordinary lead(purified in an identical series of operations), volumetrically by titra-tion with the same silver nitrate solution. The lead chloride wasfinally weigheG in a platinum boat, after fusion in hydrogenchloride and cooling in nitrogen, as recommended by Baxter andWilson. The mean of two determinations showed a difference of1 part in 225 in the volume of silver solution required for equalweights of the two lead chlorides, which is certainly many timesgreater than the possible error of the experiment unless unknownsources of error existed.The atomic weight' of the thorite lead,calculated from that of ordinary lead as 207.1, was 208.4.Photographs of the spectra of the two specimens of lead, takenby the FQry spectrograph, showed complete identity, both in thewavelengths and the relative intensity of the lead lines, with thesingle exception of one line, 4760.1, which was much stronger inthe photographs of ordinary lead than in those of the thoribe lead.As the whole series of experiments are now being repeated de ~ O P Owith the lead derived from 30 kilograms of hand-sorted thorite, dis-cussion of these results may be deferred.I n the next results published,3 the atomic weight of lead fromfive radioactive minerals, uraninite (N.Carolina), pitchblende(Joachimsthal), carnotite (Colorado), thorianite (Ceylon), andpitchblende (Cornwall), and from two commercial products, notradioactive, was determined by thO accurate methods developedin the Harvard laboratories, and used by Baxtter and Wilson intheir previous determination of the atomic weight of lead. Thelead from N. Carolina, uraninite, was a small sample of 3.8 gramsof chloride, separated from 110 grains of the purest selectedmineral by Boltwood and Gleditach ; that from Joachimsthal pitch-blende and Colorado carnotite had been separated by Fajans; tllatT. W. Richards and Max E. Lembert, J. Amw. Chem. Xuc., 1914, 36, 1329 ;Cunzpt. rend., 1914, 159, 248 ; A., ii, 653. These resnlts were riot piiblished by theauthors riiitil after the researches about to be considered, but a preliminnry announce-ment of them was iriade by K.Fajaiis under the title " Naclltrag zu dem Aufsatz' Die Radioelerrierite und das periodische system,' " n'nizcl.u,i~~ensrl,clf(ell, May 29th1914 ; also later iu Sitxungsber. der Heidelbergen h a d . d e ~ Wzss., 1914, Abt. A,,Abh. 11268 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.from Ceylon thorianite was part of 1100 grams of nitrate separatedby Boltwood from 25 kilograms of mineral; and that from Cornishpitchblende was from residues supplied by Sir William Ramsay.The methods of purification used were chiefly the recrystallisationof the nitrate and the chloride, and the precipitation of the dilut,esolution of the latter by hydrogen chloride.The final valuesobtained are shown below:Lead from N. Carolina uraninite ............................... 206.40,, ), Colorado carnotite ................................... 206'59,, ,, Ceylon thorianitc .................................... 206.82 ,, ,) Coroisli pitchblende ................................ 206.86Coiiimon lead .................................................... 207'15), ,) Joachimsthal pitchblende ......................... 206.57I n the nextt serjes,4 the lead from three uranium minerals coil-taining negligible quantities of thorium, pitchblende, carnotite,and yttro-tantalite, from one thorium mineral containing very littleuranium, monazite, and from ordinary galena, was examined.Itwas separated as metal from the crude carbonates by fusion withcyanide, converted into the nitrate and precipitated as sulphate,converted into carbonate and again precipitated as sulphate,separated as oxide by electrolysis, reduced to metal by cyanide andconverted into nitrate, and then into basic nitrate by heat. Thebasic nitrate, dissolved in water, was filtered from the insolublefraction, converted into nitrate, crystallised, and finally obtainedas metal. The metho'd of estimation of the atomic weight was t oweigh the metallic lead in a quartz vessel, to dissolve i t in con-centrated nitric acid, and t o dry to constant weight at 145O t o150°, weighing it again as lead nitrate. This is one of the methodsemployed by Stas, and for relative estimations has advantages overthe more accurate silver method in requiring less manipulation ofthe substance.The lead was purified in each case by a series ofoperations until it showed the same atomic weight after a freshpurification. The values found are shown below :Lead from carnotite ........................................ 206'36 ,, ,, yttro-tantalite ..................................... 206 -54 ,, , , pitchblende ..................................... 206'64,) monazite ............................................. 207'08,, , , galena ............................................... 207.01Unfortunately, the sources of the radioactive minerals are notgiven.Lastly,5 the atomic weight of the lead from Joachimsthal pitch-blende was accurately determined by Baxter's method.It waspurified chiefly by crystallisation of the nitrate from the hot solu-0. Honigschmid and Mlle. S. Horovitz, ibid., 1796 ; A . , ii, 653.4 Maurice Curie, Cornpt. rend., 1914, 158, 1676 ; A . , ii, 563RADIOACTIVITY. 269tion by the addition of nitric acid, followed by solution of thechloride i n saturated hydrogen chloride solution and precipitationwith water. The value 206.736 was obtained as the mean of six de-terminations varying over the extremes of 0.03 unit, and of threedeterminations varying over 0.018 unit. The possibility is men-tioned that, by selecting the pitchblende from isolated pieces ofblende, a lead might be obtained of still lower atomic weight.Bearing in mind that two out of the four researches detailedhave been carried out by chemists experienced in atomic-weightdeterminations, and that much of khe mineral examined was nodoubt of very mixed composition, so that not all the lead presentcan be reasonably assumed to have been of radioactive origin, i tis clear that the theoretical predictions have received remarkableconfirmation from this first preliminary experimental examination.Further results with carefully selecte’d minerals must be awaited.That an investigator as experienced in atomic-weight work as Pro-fessor T.w. Richards should regard his results as definitely estab-lishing a variation in the chemical equivalent of lead from differentsources, whereas earlier experimental investigations a t Harvardon this very question, in the case of the elements copper, calcium,sodium, and iron, all gave completely negative results, is perhapsthe chief result gained.The lowest value recorded, 206.40, is for carefully selecteduraninite, and the highest, 208-4, is for thorite containing a nearlynegligible proportion of uranium.The two values, 206.57 and206.74, obtained by equally skilled workers for Joachimsthal pibch-blende, clearly indicate variations in the character of the materialworked on, and the same explanation may possibly cover the varia-tions found for the other thorium-free uranium minerals, but thevalues for the thorium minerals, Ceylon thorianite, 206*S2, andmonazite, 207.08, are lower than would be anticipated if the end-product of thorium is stable and has the calculated atomic weight208.4, aitliough i t must be remembered that, owing t o its greaterrate of change, the uranium would be some three times as efficienta lead producer as the thorium.I n neither case are the essentialdata given as to the ratio of uranium t o thorium in the minerals.For an average thorianite, this ratio would be, perhaps, 1 to 4 or5, and for an average monazite, perhaps 1 to 8 or 10, so that ineach case a value well above 207 might be anticipated.The Stability of Lead from Thorium.Independently of direct experimental data, the instability of theend-product of thorium, the isotope of lead with a calculated atomicweight 208.4, has been presumed. Boltwood, and later Holmes270 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.have concluded from t’he lead content of uranium and thoriumminerals that lead could not be the end-product of thorium, butin the original conclusion old analyses of the minerals, made beforethe real significance of the lead content was appreciated, seem tohave been too Euch trusted.Thus i t may be mentioned that forCeylon thorite itself, actually containing 0.3 to 0.4 per cent. oflead, which corresponds with more than 100 million years’ produc-tion, a blank appears under the column “PbO” in the originalcareful analysis made ten years ago. The thorium minerals arecertainly less rich in lead than the uranium minerals, but then therate of change of uranium is three times greater than that ofthorium.From an old analysis of a Norwegian thorite, returned as con-taining 46 per cent.of thorium, 0.4 per cent. of uranium and lessthan 0.1 per cent. of lead, it has been calculated6 that the upperlimit of the half-period of thorium lead cannot exceed 2 x 107 years,whilst from another analysis, in which 0.02 per cent. of lead wasstated to be present, a figure ten times smaller is indicated. Thesecalculations, however, assume the equilibrium between the thoriumand lead has been reached, and, in the absence of information as t othe age and character of the mineral, may possess little reality,either on the experimental or theoretical side. The same may besaid of the application of the supposed connexion between thestability of isotopes and their atomic weights,7 which atl best is butpartly true, and can only indicate the result t’hat “thorium” leadis likely to be le’ss stable than “uranium” lead if i t is assumed,not only that “thorium ” lead does in fact disintegrate, which isthe question being discussed, but also that it disintegrates, giving8- rather than a-rays.A recent examination of the lead-thorium and lead-uraniumratio of a series of minerals from the Langesund-fjord district,south of Christiania, Norway, all of Devonian age and “almostcertainly (‘ Middle Devonian,” 8 for which, from the lead-uraniumratio, the mean value of the age of the formation had been previ-ously deduced as 370 million years? gives some indirect informa-tion on the question whether the end-product of thorium is lead.The ratio of thorium to uranium varied in the different mineralsover a range of 180.The lead-uranium ratio was, on the whoIe,remarkably constant, but there was no constancy whatever in thelead-thorium ratios. The ratio calculated on the assumption thatlead was the product both of thorium and uranium was less constantK. Fajans, Sitzungsbev. Eeidelberger Akacl. Wi~s., 1914, Abt. A., Abh. 11.7 Ann. Beport, 1913, 269.8 A. Holmes and R. W. Lawson, Phil. Mag, 1914, [vi], 28, 823 ; A., 1915, ii, 5.Ann. Report, 1911, 295RADIOACTIVITY. 2'7 1on the whole than the lead-uranium ratio. Two thorites, however,were notable exceptions, the lead-uranium ratio being between twoand three times as high as the mean for the others. It may bementioned that f o r the majority of the minerals examined theactual lead content was below 0.01 per cent., and the calculationsnaturally depended entirely, in the case of these minerals, on thepossibility of determining such minute quantities with accuracy.Other series of minerals of less definitel geological age are cited insupport of the vietw that the thorium end-product is not' lead.It is difficult a t the present stage t o evaluate the precise bearingof this evidence.Admittedly it shows-the point, indeed, was notin doubt-that some of the lead is derived from the uranium, andtherefore no constancy is to be anticipated in the lead-thoriumratio; but the further point tlhat none is derived from the thoriuminvolves, perhaps, greater trust in the method and in the analysesthan is justifiable.The relatively slow rate of change of thorium,the dubiety regarding the age and unaltered character of themineral, the lack of information regarding the initial lead contentin the mineral, and the exceptiolns referred to, must all be takeninto account, and it may well be doubted whether what is reallyrather a fine point can be settled by such means. The conclusionsappear to be biassed also by the doubtful theoretical deductionthat, since the uranium isotope of lead is stable, the uranium andthorium isotopes cannot both be stable, and therefore the thoriumisotope is unstable. Against such reasoning, that because oneisotope is stable another of different atomic weight cannot be stable,the fact of the difference between the atomic weights of commonlead and of lead of radioactive origin may now be cited.Thequestion is still sub judice until further atomic-weight estimationsare available.The Comervation of Mass in Radioactive Chmge.The recent determinations of Honigschmid on the atomic weightof radium, for which he obtained the value 226.0, lead to acalculated value for the atomic weight of uranium of practically238.0, if mass is conserved in radioactive changes, instead of 238.5,the international number. A revision of the atomic weight ofuranium has now been carried outlo by the method of Richardsand Merigold, except that. quartz vessels were employed insteadof vessels of porcelain and glass, which are slowly att'acked both bythe bromine and the uranous bromide used.The first series ofexperiments with uranous bromide, distilled, melted, and solidifiedin bromine vapour, in which the ratios UBr, : Ag and UBr, : AgBr0. Honigschmid, Compt. rend., 1914, 158, 2004 ; A., ii, 654272 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.were determined, gave as the mean of eight experiments the value238.08. In a second series, the uranous bromide was distilled,melted, and solidified in a current of nitrogen. Fourteen experi-ments gave the mean value 238.175. The first series, where,perhaps, the bromine is in excess, gives a minimum value, and thesecond series the most probable value for the atomic weight.Although considerably nearer the whole number than the inter-national value, it departs from i t sufficiently far to leave thequestion open whether the mass of the atom of radium and thethree a-particles expelled is essctly equal to the mass of theuranium atom from which they are derived.I n view of the fact that so many of the atomic weights approxi-mate to whole numbers in terms of that of oxygen as 16, whilstsome depart notably from whole numbers, this question is of primeimportance in problems concerning the origin and genesis of theelements.It has been suggested11 that in the disintegration or coalescenceof atoms a change of mass may occur proportionate to the changeof energy, a loss of mass corresponding with a liberation of energyand a gain of mass with an absorption of energy, in each caseequal to the energy which the mass lost or gained would possess,if moving with the velocity of light.The Mass and Velocities of the a-Particle.Radium Constants.I n this connexion may be discussed a new determination of themass and velocities of a-particles,l2 which was designed to test asthoroughly as possible whether the mass of the helium atom travel-ling a t high speed, which constitutes the a-particle, was identicalwith that found for the atomic weight of helium, the older deter-minations having indicated a mass some 4 per cent. less. Fromordinary electsochemical data, that is to say, the value of thefaraday, the ratio of the charge to the mass of the hydrogen ion is9670. With 3.998 taken as the mean of recent atomic-weightdeterminations f o r helium, the value for the ‘‘ bivalent ” a-particleshould be 4826 instead of 5070, the experimental value.By theexercise of great care and the experience accumulated in a longacquaintance with the problem, an accuracy of 1 part in 400 wassecured finally in the measurements of this ratio from the magni-tude of the electromagnetic and electrostatic deviations of thea-particles from radium emanation, radium-A, and radium4 in avacuum. Values lying between 4813 and 4826 were obtained, theSir J. J. Thornson, “The Atomic Theory,” Ronianes Lccture, 1914, p. 16.12 Sir E. Rutherfordand H. Robinson, Phil. Mag., 1914, [vi], 28, 552 ; A . , ii, 789RADIOACTIVITY. 273mean being 4820, which agrees with the calculated value within thelimits of experimental error.The new value f o r the initial velocity of the a-particle ofradium-C, namely, 1.922 x loy cm.per second, is some 7 per cent.smaller than the previous one. Before, the experimental value forthe development of heat from radium agreed excellently with thatcalculated from thO thermal equivalent of the kinetic energy of thea-particles expelled. On the new data, however, the observed heateffect is some 7 per cent. greater than that calculated from the massand velocities of the expelled a-particles, including, of course, thekinetic energy of the recoil atoms. It is by no means necessarythat the total heat energy of radioactive change should be the sameas the kinetic energy of the products. It may be either greateror less, according as the change itself is exothermic or endo-thermic.I n other words, the kinetic energy of the a-particles andof the recoil atoms will together equal the heat evolution only ifthey are entirely responsible for the thermal effect. Rutherford 15suggests that in an a-ray change, wherein the magnitude of thenuclear charge of the atom decreases, there is a decrease in theenergy of the electronic system around the nucleus, which presum-ably appears as heat, and calculates that some 10 per cent. of thethermal evolution is due t o this cause, only 90 per cent. beingdue t o the mechanical energy of the expelled a-particle. I n a &raychange, on the other hand, wherein the nuclear charge increases, acorresponding increase of the internal energy of the electronicsystem of the atom occurs. This is supported by the fact thatthe heat evolution of radium-B and -C together, in which j3- aswell as a-rays result, is less than is to be expected from the evolu-tion of the emanation and of radium-A, in the change of whicha-rays only are expelled.The view, on close examination, seems topresent some difficulties of a fundamental chasacter, not so muchduring an a-disintegration where the residual atom may evolveother energy which afterwards appears as heat, as during a &raydisintegration, where a transformation of heat of the surroundingsinto internal atomic energy seems to be required.I n the same paper Rutherford revises all the radium constantsgiven in his " Radioactive Substances and their Radiations " interms of the International Radium Standard.The half-period ofradium is 1690 years, or average-life period 2440 years, calculatedby taking the iiumber of a-particles expelled per gram of radium (byitself) per second as 3.57 x 1O1O and 4.61 x 10-lo E.S.U. as the valueof the atomic charge. The experimental values for the half-period,2000 years (Bolt4wood), 1800 years (Keetman), and 1730 yeamly Sir E. Rutherford, Phil. Mag., 1914, [vi], 28, 320 ; A . , ii, 788.REP.-VOI,. XI. 274 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.(Stefan Meyer) are considerably higher than the calculated value,but the latter depends upon the agreement of so many independentdata that it is unlikely to be seriously in error. The Boltwood-Rutherfoird uranium ratio of radium t o uranium in minerals onthe international st#andard is 3-23 x 10-7, but a more accuratedetermination of this important constant is much t o be desired.a-Particles and ‘( R-Particles.”Rutherford’s nuclear theory of atomic structure leads to someinteresting consequences when collision occurs between the a-particleand an atom of similar or smaller mass, and the effect on thecollision on the atom struck, as well as on the velocity of thea-particle, is important.14 I n the case of helium, where the massesof both atoms are alike, the result follows that no encounter candeflect t’he a-particle from its course through an angle greater than aright angle, whereas in the case of hydrogen the angle of maximumdeflexion is 14O29‘.In the latter case, an undeflect’ed a-particlemay aignify one that has not been in collision at all, or one thathas experienced a perfectly full collision and followed on in itsinitial path behind the more rapidly recoiling hydrogen atom.Oncertain assumptions, i t was estimated that the maximum velocitywhich a recoiling hydrogen atom could thus acquire was 1.6 timesthat of the a-particle striking it, and its “range” in hydrogenshould be 117 cm., or possibly more.In an experimental search for such recoiling hydrogen atoms, or“ H-particles,” 16 in which a movable source of a-particles was placedin a wide tube filled with hydrogen at variable pressure, scintilla-tions, few in number and less intense than those. produced bya-particles, were observed on a zinc sulphide screen, placed a t theend of the tube, far beyond the extreme range of the a-particlesthemselves in hydrogen.I n air, no such scintillations wereobserved. In hydrogen, a suitable aluminium screen, placeddirectly in front of the source of a-particles, suppressed thesescintillations, but when placed near the screen the scintillationswere again seen, showing that they have their origin in thehydrogen, by impact of the a-particles. So far as could be seen,these “H-particles” obey a similar law of absorption in variousmetal foils to that obeyed by the a-particles, but it is to be ex-pected that they will prove much more penetrating, on account oftheir greater velocity and smaller mass.A special search for radiant particles, differing eit-her in mass orl4 C.G. Darwin, Phil. Mag., 1914, [vi], 27, 499 ; A . , ii, 324; Sir E. Rutherford,l5 E. Marsden, ibzd., 824; A., ii, 407.ibid., 488 ; A., ii, 323RADIOACTIVITY. 275charge from the a-particle, in the disintegration of radium emana-tion gave completely negative results.16y-Rays.Foremost in interest in connexion with the physics of radia-tions has been the determination of the wave-lengths in the spectraof the y-rays by reflection from crystal surfaces, the first step ofwhich was announced last year.17 First, however, may be nieiitionedthe completion of the researches on the analysis of y-rays by mealisof their absorption-coefficients, by the examination of the uraniumy-rays.18 These rays come from uranium-X, and -X2, but theirorigin, as between these successive pro’ducts, is undecided, althoughby analogy it may be surmised that only the most penetrating typecomes from uranium-X,.Three types were disiinguished. For thefirst, which comprises 40 per cent. of the total, the value of p / din aluminium is 8.9, for the second 0.26, and for the third 0.052.The first is probably a characteristic A--radiation of the L-series.The value of the atomic weight of uranium-S, 234, and the valueof p / d , 8.9, compared with these values for mesothorium-11, 228and 9.5 respectively, favour the view that radioactinium, withp / d intermediate a t 9.2, has an intermediate atomic weight, 230,and therefore that actinium also has the atomic weight 230, whichis a point of considerable importance.19 However, this would makethe atomic weights of actinium-B and radium-B identical, whereasthe values for p / d of their characteristic X-radiations are, re-spectively, 11.4 and 14.7.Hence the evidence froin this source isconflicting.The examination of the y-rays froin radium-B and -C by reflec-tion froin crystal surfaces,20 in addition to its intrinsic interest, hasalso been the means of putting to an unexpected experimental testthe prediction from the theory of isotopes, that the spectra ofisotopic elements would prove identical.21 The main lines in thespectrum of the soft y-rays of radium-B are reflected froin rock-salt at angles almost exactly loo and 1 2 O , and the wave-lengthscalculated from them, in Angstrom units (10-8 cm.), are 0.982and 1-278 respectively.By extrapolation from Moselcy’s results(p. 277) for the wave-length of the L-series characlerisLic X-rayof gold t o that of lead, i t was calculated that the characteristicl6 Sir E. Butlierforcl atrd H. Bobinson, Phal. Mug., 1914, [vI], 28, 552 ; A., ii, 789.l7 Ann. Report, 1913, 283.H. Richardson, PhzZ. Mag., 1914, [vi], 27, 252 ; L4., ii, 160.Compare Ann. Keport, 1913, 269.2o Sir E. Rutherford and E. N. da C. Andrade, Phil. Mccg., 1914, [vi], 27, 854;21 See Awn. Report, 1912, 322, for the oiiginal snggestion.28, 263 ; A., ii, 408, 698.T 276 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.X-ray of lead should be reflected from a rock-salt crystal a t anangle of 12*07O, whereas the strongest line in the radium-B y-rayspectrum is reflected a t 12.05O.Fleck has shown that radium-$)is isotopic with lead, and, in order t o test directly whether thecharacteristic X-ray spectrum of lead would prove identical withthe y-ray spectrum of radium-B, the latter was compared directlywith that of the secondary y-rays generated in a block of lead byimpact of fl-rays. Only faint lines were obtained in the latter case,but two of them gave reflection angles of 10°2’ and 12OO’, in goodagreement with the radium-B lines. On substituting for the blockof lead one of platinum, quite distinct lines resulted. The atomicweight calculated for radium-B is 214, whereas that of lead is 207,and the authors conclude that the hypothesis that isotopic elementsof different atomic weights have identical spectra is verified in anunexpected manner.I n the further examination of the more penetrating y-rays ofradium-B and -C, new methods of greater accuracy were developed,in which the rays were transmitted through a crystal and fellnormally on a photographic plate.Blank absorption lines andenhanced reflected lines on the plate both gave the angles of reflec-tion required with considerable accuracy. The spectrum ofradium-C y-rays appears to consist of lines reflected from rock-saltat angles 441, loo’, loll’, and 1°24‘, with wave-lengths of 0.071,0.099, 0.115, and 0.137 in Angstriim units. For radium-By thespectrum of the penetrating y-rays appears t o consist of lines re-flected a t 1O371, 1°44’, 2O0’, 2 O 2 0 / , 202W7 20401, 3001, 3O18‘, 4001,4 O 2 2 / , with wavelengths 0.159, 0.169, 0.196, 0.229, 0.242, 0.262,0.296, 0.324, 0.393, and 0.428, of which, possibly, the third andsecond from the last are second-order repetitions.The mostiniportant are the lines reflected a t lo, and the close doublet re-flected a t 1O371 and 1°43/. I n a later paper22 this is regarded asprobably having one component due to radium-B and one t oradium-C (see p. 283).The shortest wave-length, 0.071, that of one of the radiuni-Cy-rays, is seven times shorter than the shortest hitherto measured,namely, the 1‘-series X-ray line of silver, and the authors expresssurprise that the architecture of the crystal is fine and definiteenough to resolve it. Although the range of the thermal agitationof the atoms in the crystal might be expected to be of the sameorder of length, yet placing the crystal in liquid air did notimprove its resolving power.It is probable that one of the lines of wave-length 0.159 and0.169 is a characteristic X-ray line of the K-series of lead(radium-B), but the lines of radium-C cannot belong t o the X -22 Sir E.Rutherford, Phil. Mag., 1914, [vi], 28, 305 ; A , , ii, 789RA DIOAC‘l’I VITY. 217series of bismuth, and are probably in a new and hitherto un-observed series of higher frequency, which is named the H-series.The work on y-rays, although as yet not complete, raises theexpectation that the complicated mixtures of y-radiations givenby the radio-elements will all be resolved into characteristic X-raysof one o r other of three series, the L, K , and N series, the wave-lengths and penetrating powers of the three series being simplyrelated t o one another on the one hand, and on the other to theatomic number of the source, the greater the atomic number, orthe nearer the element is to the end of the Periodic Table, theshorter being the wave-length and the higher the pelletratingpower.The difficult question of the hardening of y-rays of radiuni-G,whereby, by passage through a heavy metal, the rays become morepenetrating to a lighter metal , has been recently re-e~amined.~~The fact that the spectrum of the y-rays of radiuni-C comprisesthree lines is interesting in view of the practically exponentialcharacter of the absorption, and i t is suggested that “hardening”may be due to the weeding out of the two less penetrating rays.Of great general interest in connexion with these advances inour knowledge of y-rays is the light thrown on the practical problemof how to generate X-rays as penetrating as the y-rays of radium,and so t o avoid the use of that extremely expensive substance inmedicine.24 Rutherf ord and Andrade deduce from Planck’s rela-tion between energy and frequency (p.281) that with a fall ofpotential oE 180,000 volts, which is sufficient to give a velocity 0.7of that of light to the electron, it should be possible to generateX-rays as penetrating as the y-rays of radium-C. With a Coolidgetube, this should not now be beyond the range of possible experi-mental accomplishment.This opinion is probably the reverse ofwhat a physicist a year ago might have been inclined to give, andis very significant.X-Ray 8pectra of the Eleme,nts.Last year, Moseley determined the wave-lengths of the character-istic X-rays of the ten consecutive elements in the Periodic Tablefrom calcium to zinc, and found that the spectrum of each con-sisted of two rays, the wave-lengt,h of the stronger rays beingsimply connected with a set of consecutive integral numbers from19 to 29, numbers, in fact, which represent the position of theelement in the Periodic Table, excluding hydrogen, calcium being23 S. Oba, PhiE. Mag., 1914, [vi], 27, 601 ; A . , ii, 409.Compare also-F. Dessauer, Yhysikffil. Zeitseh., 1914, 15, 739 ; A ., ii, 6992’78 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the 20th and zinc the 30th element in order of ascending atomicweight.25The facts that, in radioactive changes, when two positive chargesare expelled from the atom as an a-ray, the element changes itsplace in the Periodic Table by two places in the direction ofdiminishing atomic mass, and, when one negative charge is ex-pelled as a @-ray, the element changes one place in the oppositedirection, and, moreover, that all the elements occupying the sameplace in the Periodic Table are chemically identical, had alreadysuggested that the successive places in the Periodic Table correspondwith unit differences in the net value of the internal charge of theatom. Moseley’s work gives us the means of establishing, for thefirst time, the relative value of this charge for each element, andthe absolute number of places in the Periodic Table, over the rangestudied.Since then, what amounts to a veritable roll-call of the elementshas been made by this method.26 Thirty-nine elements, withatomic weights between those of aluminium and gold, have beenexamined in this way, and in every case the lines of the X-r,tyspectrum have been found to be simply connected with the integerthat represents the place assigned t o it by chemists in the PeriodicTable.That is to say, giving the atomic number 13 t o aluminium,the 13th element in order of atomic weight, the atomic numbersof all the elements up to gold, the heaviest element yet examined,can be found.The general method is t o plot the square root of the frequencyof the ray in question against the atomic number of the element,when a series of straight lines results.For the lighter elementsbetween aluminium and silver, the X-series of characteristic X-rayswas examined, and for the heavy elements between zirconium andgold, the L-series. I n the first case, the wavelengths range from8.4 to 0.56, and in the second case from 6.09 t o 1-29, Angstromunits. The longer waves are so easily absorbed, that the experi-mental difficulties are considerable, the spectrometer, as well asthe X-ray tube, having to be exhausted. I n the K-series twos lines,and in the L-series five lines, exist, of which three, designated, inorder of decreasing wave-length and decreasing intensity, a, P, y,have been plotted.There is always, also, a faint companion, a’,on the longer wave-length side of a, and in the rare-earth elementgroup a rather faint $-line between P and y. I n addition, thereare a number of very faint lines of longer wave-length than u.When plotted as described above, each of these rays gives a separateline of slope slightly different from the others. For the L-series,The atomic number thus found for gold is 79.25 A m . &?port, 1913, 272.26 H. G . J. Moseley, Phil. Mag., 1914, [vi], 27, 703 j A., ii, 326RADIOACTIVITY. 279the relation is not accurately linear, a distinct, although slight,curvature of lines being observe<d.For the a-line of the E-series of the light elements, the relationbetween frequency, v, and atomic number, N , is gven byv=A(N-1)2.For the a-line of the L-series of the heavy elements,v = A ' ( N - 7.4)2.A and A' are constants connected with the fundamental Rydbergfrequency, vo, by the relations:A = (1 / 1 2 - 1 / 22)vO = 3/4vo,A 1 = ( 1 / 22 - 1 / 32) vO = 5 / 3 6v0.It will be noted that it is only for the I{-seriea that the squareroots of the frequencies of the a-line are proportional to integers,which integer is one less than the atomic number or place of theelement in the, Periodic Table.For the L-series, the square rootof the frequencies of the a-line is proportlional t o the atomicnumber diminished by 7.4. I n neither case is the absolute atomicnumber found by the generalisation, and, although for the a-line ofthe L-series the roots of the frequencies are proportional to thenumbers of the positions occupied by the elements in the PeriodicTable if hydrogen is omitted, this is probably not significant.Of greater interest to chemists will be the results as regardselements still missing and those misplaced as regards atomic weightin the Periodic Table.Thus, the elements chlorine and potassiumcorrespond with the numbers 17 and 19, the number 18 beingvacantl for argon, not determined; iron, cobalt, and nickel corre-spond with the numbers 26, 27, 28; molybdenum, ruthenium,rhodium, palladium, silver with the numbers 42, 44, 45, 46, 47;tungsten, osmium, iridium, platinum, gold with the numbers 74,76, 77, 78, 79. The missing numbers 43, 75, obviously correspondwith the two vacancies in the Periodic Table below manganesethe real exist'ence of which the writer, a t least, latterly had beeninclined to doubt.I n the region of the rare-earth elements, this roll-call becomesfascinating.I n this most difficult branch of experimental chem-istry, how many elements have not yet been discovered, how manyhave aliases? Moseley finds only one place clearly vacant, namely,that between neodymium and samarium. In the following list,corrected by the author since the publication of his paper, thenumber in the upper column represents t,he atomic number, andthe symbol in the lower column the corresponding element. Anasterisk indicates that the atomic number has been experimentall280 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.determined from the X-ray spectrum.been inferred :I n the other cases i t has* * *$7 E;”s $9 s“0 61 62 63 64 65 & 67 6: 69 70 71La Cc Pr Nd Sa Eu Od Tb Dy Ho Er Tin Yb LnThe element tantalum, at which the normal course of the PeriodicTable is resumed, has the atomic number 73, and the number 72,i t is thought probable, belongs to the keltium of Urbain.Hence,counting lanthanum and cerium, but not keltium, there are fifteenrare-earth elements possible, of which fourteen are known.There may be a re-shding of some of t4e rare-earth elementsamong the available places when their X-ray spectra have beendetermined, but the fact that the precise number can now bedetermined by this method is alone sufficient t o prove its invalu-ableness.Again, compared with the complicated light spectraemitted by the elements, there is a simplicity and definiteness aboutthese X-ray spectra which ensures that in no very long time theywill supplement, if not displace, ordinary spectroscopic methods asa means of identification of elements. The difference between thetwo kinds of spectra, on the one hand, the light spectrum generatedby the complicated electronic swarm which surrounds and hidesfrom investigation the real material atom within, and, on the other,the X-ray spectrum, probably generated by a few only of the inner-most electrons, is analogous t o the difference between a complexcryptogram and plain writing.Perhaps not the least significantdeduction which follows from this roll-call of the elements is that,on the whole, its evidence seems to be against the existence of thecelmtial elements coronium, asterium, nebulium, etc.If hydrogen is the first element, gold is the 79th, and threeonly between these remain undiscovered, one rareearth elementand the two homologues of manganese. As the writer has shown,27the course of the Periodic Table from tantalum t o uranium is pre-cisely analogous to the course from vanadium to molybdenum, onlytwo places being still vacant, namely, those of the heaviest repre-sentatives of the halogen and alkali-metal families. This gives 92for the atomic number of uranium. Hence, from hydrogen touranium there are 92 possible e1ement.s inclusive (not distinguish-ing between isotopic elements) of which five, with atomic numbers43, 61, 75, 85, and 87, remain t o be found, although the last twomay be too unstable to exist.If the periods are made t o commence from the carbon famiIyrather than from that of the inert gases, we have, before carbon,five elements belonging to the latter part of a first short period,then two complete short periods each of eight members, then t8wo27 “ Chemistry of the Radio-Elements,” Part 11RADIOACTIVITY.281long periods each of eighteen elements, bringing the series tolanthanum. From cerium to lutecium there is the rare-earthelement period of fourteen elements. Next is the missing elementwith atomic number 72, which may be keltium, but may be amissing analogue of zirconium, cerium, and thorium.Includingit, there follows another complete normal long period of eighteenelements, and three elements of the next, before the end of theseries is reached.The discussion of the mathematical theory of atomic structurefavoured by these results, which is still in embryo, cannot beincluded here.28Connexion between the p- and y-Rays.The P-rays consist of electrons moving with definite velocity, and,by the application of a magnetic field, the P-rays of many of theradbelements can be resolved into a magnetic spectrum, consistring of a number of groups of rays having the same velocity, whichare deviated to the same extent and produce definite lines, fromthe position of which the velocity may be deduced.29 The y-rays,on the other hand, have been recently proved t o be light waves ofexcessively short wave-length, which can be determined by reflectionfrom crystal surfaces.That a very close connexion exists betweenthe p- and y-rays has for long been known. Making use of Planck’srelation between the frequency and the energy of radiation, Ruther-ford has sought, with considerable success, for a connexion betweenthe energy of P-rays and the frequency of the y-rays accompanyingthem.It has been found30 that when the magnetic spectrum of asource of P-rays is examined, not by the photographic method, butby Geiger’s counting method, by means of the fitful discharge fromx point kept at a high potential when a- or P-rays traverse the gasin the neighbourhood of the point, that the line-spectrum is ofvery small intensity compared with the continuous spectrum.Inother words, in the case of the &rays of radium-B and -C, for ex-ample, most of the rays are expelled with velocities uniformly dis-taibuted over a wide range, whilst the number producing the linescorresponding with groups of rays of the same velocity is relativelysmall. Probably the photographic plate exaggerates the relativeimportance of the line, as compared with the continuous spectrum.2y J. W. Nicholson, Phil. Mag., 1914, [vi], 27, 541 ; 28, 90 ; A., ii, 325, 643 ;W. M. Hicks, ibid., 28, 139 ; A . , ii, 599 ; J. B. Rydberg, ibid., 28, 144; A.,ii, 599.29 Alin. Beport, 1910, 265.J. Chadwick, IZcr.Deut. physikal. Gcs., 1914, 16, 383 ; A . , ii, 408282 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Another example of the exaggeration introduced by the photo-graphic plate is discussed under the y-rays of radium-B and -C, inthe spectrum of which the lines due to the soft rays of radium-Bgive much the most intense photographic image, although repre-senting only 0.1 per cent. of the total y-ray energy. Certain radio-elements like radium-E and uranium-X, the latter of which hasbeen recently examined,31 give few or no lines, although, in thelatter case, several broad bands may be distinguished in thespectrum.An investigation of the magnetic spectrum of the &rays excitedby the y-rays of radium-B and -0, in various metals, by the photo-graphic method, showed that these rays also have lines in theirspectrum.When the &rays were excited in lead, the velocities ofthe principal secondary &rays were the same as those of theprimary &rays, but, when excited in gold, the velocities of thesecondary rays were found to be some 2 per cent. greater than thecorresponding primary rays. This is of interest, because of theisotopism of radium-B and lead. The primary P-rays given out byradium-B appear to be of identical character with the secondary&radiation excited by y-rays in its isotope, lead.As a consequence of the great advances made in the last twoyears, Rutherford has modified his theory of the connexioii betweenthe P- and y-rays.32 Instead of supposing that the homogeneousgroups of P-rays were due t o the decrease by quanta of the energyof the primary &particle in exciting y-rays, it is now supposedthat they arise from the collision of y-rays with &rays.A&particle is expelled a t a definite speed from the nucleus of the atom,and, in passing through the outer distribution of electrons, stiff erscollision and shares its energy with these electrons, escaping witha velocity which, as a statistical result with a large number ofatoms, is continuously distributed within certain limits. Thusarises the continuous spectrum of 8-rays, typical. of the /3-rays ofradium-E and uranium-X, and important, as recent work shows,in all cases. I n the next place, it is supposed that there are well-defined regions in the electronic distribution capable of being setinto vibration by the passage of the P-particle, the vibrations con-stituting one o r other of the '' characteristic " y-rays of the atoms.Accompanying the emission of these y-rays are one o r more groupsof /3-rays of definite speed, the latter always accompanying theformer.This is in accordance with the evidence that elements likeradium-E and uranium-X, which give continuous P-ray spectra,3 l 0. von Baeyer, 0. Hahn, and L. Meitner, Phgsikal. Zeitsch., 1914, 15, 649 ;32 A m . Report, 1912, 298 ; Phil. Mng., 1914, [vi], 28, 305 ; A., ii, 789.A., ii, 607RADIOACTIVITY. 283give very little y-radiation in comparison with elements likeradium-B and -C, which give well-marked &ray line spectra andpowerful y-rays.I n the y-rays of the last-mentioned class, how-ever, there is probably, in addition to the vibrations of definite fre-quency, a small part with a continuous spectrum.The above point of view requires one very interesting con-sequence. It is necessary to suppose that the direction of expulsionof the primary &ray is definite with regard to the orientation ofthe internal atomic structure, so that whether or no y-rays areexcited depends, not so much upon whether regions capable ofbeing set into vibration exist within the atom, as upon whetherthese regions are traversed by the expelled P-particle. Thus,radium-B and radium-D are isotopic, and it is to be expected thatthey will give identical y-ray spectra when bombarded by P- orcathode-rays (p.276). That their y-ray spectra are entirelydifferent is only intelligible if the P-particle in the two cases is ex-pelled in different directions, traversing different vibratingregions. Using the term X-ray t o indicate radiations generatedby external bombardment of atoms by p- or cathode-rays, in contra-distinction from the term y-rays t o indicate radiations generatedby internal bombardment of the atom by expelled P-rays, i t is to beexpected that, in the former case, all possible types of character-istic radiation will have a chance of being excited, whilst in thelatter case only those arising from the particular regions traversedby the definitely orientated P-ray will be generated. The energyE of a single y-ray is regarded as emitted in quanta in conformitywith what is now supposed t o be true of radiation in general, andto be connected with the frequency v of thO y-ray by the relationE=hv, where h is Planck's constant.The energies of the y-raysin the line spectra of the penetrating y-rays of radium-B and -Care so found. The strongest line of the radium-C y-ray spectrum,that reflected from rock-salt a t lo, has an energy 1-25 x 1013~,where e is the atomic charge. This is very nearly three times theconstant quantity of energy, 0.4284 x lO13e, integral multiples ofwhich represent the energies of many consecutive lines in the j3-rayspectrum of radium-(7.33 Another such energy quantity is0.74 x lO13e, which, in multiples ranging from 2 to 23, representsthe energies of some thirteen lines in the P-ray spectrum ofradium-C.This corresponds with a y-ray which would be reflectedfrom rock-salt a t nearly 1°40/, and is probably one of the doubletbefore referred to (p. 276) reflected a t that angle, both of tliecomponents of which were a t first ascribed to radium-B.I n the same way, the energies of many of the P-rays of radium-B33 Ann. RepoTt, 1913, 280284 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.agree very closely with that calculated from the frequencies of they-rays reflected from rock-salt at 2O20', 2O28/, 3O18', and possibly1°24/. Lastly, the energies of the groups of 6-rays from radium-Bagree well with certain of the y-rays from radium-B, as is a possi-bility in view of the isotopism of these elements.The intense softy-rays of radium-B, reflected a t loo and 1Z0, do not seem t o beconnected with any of the observed &rays. Although giving themost intense lines, their energy is extremely small, being only some2 per cent. of the total y-ray energy of radium-B.34 In the y-raysof radium-B and -C together, i t was estimated that the relativeenergies of the soft rays of radium-R, the hard rays of radium-B,and the rays of radium-C, are in the ratio 1 : 45 : 639 respectively.E1ectrochemica.J Proofs of the Theory of Isotopes.I n three diff erenf ways, the electrochemical identity of isotopicelements has been put in evidence.35 The decomposition potentiala t which radium-E is deposited on the cathode is altered in thesame direction and quantitatively t o the same amount by theaddition of the isotopic element, bismuth, as, according t o Nernst'stheory, i t would be by adding the same number of radium-E ions,and a similar fact has been established with regard to thorium-Band the isotopic element, lead.Thus, in one experiment with asolution of radium-E, calculated to be 10-9 normal, a sudden in-crease in the quantity of radium-E deposited on the cathodeoccurred a t - 0.24 V , measured against the calomel electrode.When the normality was increased t'o 10-4 by thO addition of theisotope, bismuth, the sudden increase occurred a t - 0.14 T7.According to Nernst's theory, the increase of concentration tentimes should change the decomposition potential Om018'V, so thatthe calculated change is O.O9V, and that found, 0.10V. Witha thorium-B solution calculated to be 10-12N, the addition of theisotope, lead, to a normality of 10-3 decreased the potential atwhich peroxide was deposited on the anode by 0*26V, whereas thedecrease calculated from theory is 0.252 V .Secondly, for the deposition of radium2 and of thorium-B a tpotentials below the decomposition voltage, i t was shown that theaddition of isotopic elements prevents this deposition, other ionsbeing without effect. Thus, approximately 4 per cent.of theradium-E present was deposited on an electrode of area 1 sq. cm.in twenty-four hours, a t a potential of -0*17V, but when thesolution was made N/100 with respect to bismuth ions, this deposi-tion was prevented.Making the solution lO-5N with respect toa4 Miss J. Szmidt, Phil. Mug., 1914, [si], 28, 527 ; A., ii, 792.35 G. v. Hevesy and F. Yaneth, Physikul. Zeitsch., 1914, 15, 797R A D I 0 A @TI V ITY . 285lead lowered the percentage of thorium-B, anodically deposited asperoxide, from 5 to 0.5, whilst in 10-3N-solutions no perceptibledeposition occurred. The presence of thallium or of ions otherthan that of lead had no effect.The last proof depended upon the preparation of pure radium-Din appreciable quantity, and its use in a galvanic chain.36 Thispreparation has been previously attempted, but without completesuccess.37 One curie of emanation, from the large quantity ofradium available a t the Vienna Institute, was sealed in a quartzvessel until its change was complete; the radium-n formed wasdissolved in nitric acid and electrolysed.According to the condi-tions, the deposit could be collected as metal on the cathode or asperoxide on the anode. Preliminary experiments have shown thatin the latter case 10-3 mg. of lead produces a clearly visibleand electrochemically active deposit on a fine platinum wire. I nthis way, a perceptible deposit of pure radium-D peroxide wasobtained, so free from ordinary lead that an artificial contamina-tion by mg. of lead could easily be experimentally detected.The following galvanic chain was set up,Pt,[Ra-D]O, J [ Rs-D](NO,),,HNO,,[Ra-D]O, I KNO, I KCI,Hg,CI,,Hg1 V N 10-3177 sat. N N sat.and found t o have the potential -0.884V.By substituting forthe radium-D peroxide elect'rode a similar one prepared withordinary lead, the potential found was -0.888V. I n anotherresearch lead nitrate was added t o the radium-D solution, andthe change of potential measured for concentrations of 10- 5-, low3-,and 10-1-N with respect t o lead, both for the lead peroxide andthe radium-D peroxide electrode. I n each case the same changeof potential occurred, showing that in Nernst's equation i t is thesum of the conceiitrations of the isotopic ions which fixes thepotential of the electrode, and that lead ions and radium-D ionsare electrochemically identical. These results probably constitutethe most severe test t o which the consequences of the theory ofisotopic elements have as yet been put. Another investigationhas shown that the electrolytic potentials of thorium-B andradium-B are the same as those of lead,36 to an accuracy of 2 x 1 0 - 5volt.New Work o n the Disintegration Series.The preliminary announcement is made of the discovery of anew, long-lived member of the uranium disintegration series,39 iso-3(5 See also Ibid., Bcr., 1914, 47, 2784.'' Ann. Report, 1911, 297.'* Z. Klemensiewicz, Compt. rend., 1914, 158, 1889 ; A., ii, 606.39 I<. Fajans and Helene Towma, Naturwissenschaften, 1914, 685286 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.topic with bismuth, and giving u-rays. It was thought thatradium-G, the end-product isotopic with lead, might change withthe emission of P-rays into a further product, “radium-H,” whichgave u-rays, producing an isotope of thallium.This would accountfor the presence of bismuth and thallium in pitchblende. Thebismuth from Joachimsthal pitchblende, after purification, showedan a-activity, several times greater than that. of uranium, that couldnot be removed by a chemical purification which would havesufficed t o remove polonium, or by fractional precipitation ofthe oxynitrate. The range of the a-rays was found to be about3 em., which would correspond with a period of between 105 and106 years. From the a-activity of the preparation, a maximumperiod of 108 years was indicated.No actinium wasfound in a concentrated ionium preparation four years old. Anexamination of pitchblende f o r the supposed a-ray-giving parentof actinium, the heaviest member of the tantalum family, gaveno result.Tantalum, precipitated in the solution and purified,proved to be inactive. It is quite possible that “ekatantalum”departs sufficiently in chemical character from tantalum for thismethod to have been effective.40A thorough examination of the uranium-radium ratio in car-notites of American origin led to the interesting result, that whensamples were taken of large lots, more than 1000 kilos., the ratiowas found to be practically identical with that of pitchblende andother uranium minerals.41 With small samples abiiormal ratios,both higher and lower than the equilibrium ratios, were obtainedApparently, local transportation of radium occurs within the ore-bed which causes differences that are completely equalised whenlarge samples are worked upon.It is pointed out that aridityseems to be a necemary condition for the existence of carnotitebeds, and that the rainfall is small. This may cause local trans-positions rather than complete removal of the radium, as un-doubtedly occurs with a ~ t u n i t e . ~ ~A very accurate determination of the periods of actinium andthorium emanations, in which the decay of the preparations to1/2000th of the initial value was followed, gave the values 3.92and 54.53 seconds respectively for the’ half-periods, or 5.656 and78.69 seconds for the periods of average life.43With regard to the actinium active deposit and the question40 C. Gohring, Phy8ikal. Zeitsch., 1911, 15, 642; A ., ii, 608.41 S. C. L i d and C. F. Whittemore, J. Amer. Chem. Soc., 1914, 36, 2066 ;42 Ann. Report, 1909, 260.43 P. R. Perkins, Phil. Mag., 1914, [vi], 27, 720 ; A., ii, 410.The origin of actinium still remains unsolved.A . , ii, 794RADIOACTIVITY. 287whether the series branches a t the C member, analogously to theother two series,44 it has been reaffirmed that the a-particles, whichhave a range of 6.4 cm., and constitute 0.15 per cent. of the whole,are due t o a branch prod~ct.~5 Confirmation of their existencehas been obtained by an ionisation method, and they have beenfound t o decay with the period of the actinium active deposit.A somewhat disconcerting discovery has been made with regardto the volatility of the various members of the active deposit ofthorium46 Some evidence was obtained in 1912,47 by L.Meitner,of a chemical separation of the two products of the active deposit,giving 35 per cent. and 65 per cent. of the a-rays respectively, byimmersing nickel plates in a solution containing stannous chloride,and comparing the a-activity of the deposit with that of the solu-tion evaporated t o dryness. It appeared that the product giving65 per cent. of the a-radiation alone was deposited, the other beingleft in solution. These results were criticised, and supposed t o beaccounted for by the abnormal volatility of the C-member inthe presence of hydrochloric acid.48I n the present experiments, the active deposit was submittedto carefully regulated temperatures in an electric furnace, and theproportion of thorium-C volatilised was determined.From a-raymeasurements, the curve of percentage volatilised, plotted againstthe temperature, indicated that the C-member was volatilised intwo stages. The first stage commences a t 750°, and correspondswith 35 per cent. of the a-activity, whilst the second stage beginsat 900°. From l3-ray measurements, however, volatilisation of theC-member does not appear to commence below 900°. Thisindicates that the C-member, giving first a-rays and then &rays,is distinct from that giving first &rays and then a-rays, instead ofbeing the same homogeneous element disintegrating dually, in pro-portion 35: 65, respectively, as has been previously assumed.Thorium-B, which is volatile a t 500°, is known to be the productof thorium-C via the a, then @change, which is the 35 per cent.branch.Additional evidence that the a-rays come from two dis-tinct products was derived from the fact that, when heated below900°, the @rays from the preparation, after cooling, show aninitial rise, due t o re-accumulation of thorium-D, but above 900°no such rise occurs. Below 900°, thorium-D, but not its parent, iscompletely volatilised, whilst above 900° both parent and product44 Ann. Report, 1913, 2iO.46 E. Marsden and P. B. Perkins, Phi/. Mag., 1914, [vi], 27, 690 ; A., ii, 410 ;46 A. B. Wood, €'roc. Physical SOC., 1914, 26, 248 ; .4., ii, 6(J6.47 Ann. Report, 1912, 314.48 E. Marsden and R. H. Wilson, PhiE. Mag., 1913, [vi], 26, 354.R.W. Varder and E. Marsden, ibzd., 28, 818 ; A., 1915, ii, 4288 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.are completely volatilised. The authors attempt to explaintheir results by supposing that the 35 per cent. of lower rangea-rays, hitherto regarded as resulting in one mode of the disinte-gration of thorium-C, come from a new product, " Ca," of periodof the order of a minute, according to the scheme:a (5'0 cm.) B and y+ ? +D--- c a -? /r5GyA 1 niin. (1) 3.07 min.(volatile (volatileB (soft) a t 750"). a t 500").+ C -+ B --?a (8'6 cm.)60.3 \ 10'6 hrs.(volatile miiintesat 750"). (volatilea t 900"). %\ & ? 4 1 C' -____10-llsec.It is assumed t h a t thorium-C disintegrates dually as before, butgives &rays, presumably, in both modes.Such an explanatioiiappears to run counter to the periodic law generalisation, for?according t o it, thorium-D should be isotopic with lead rather thanwith thallium. The experiments are very suggestive, and furtherwork promised on volatilisation in atmospheres of different gasesand on the behaviour of the other active deposits will be awaitedwith inberest_. I n the meantime, i t may be noted t'hat there is avery direct tlest of the alleged separation, for a change of the35: 65 ratio of the long- to the shor'crange a-particles should occurin the above deposit, heated a t temperatures between 750° and900°. Upon the constancy of this ratio, under all conditions yettried, the older hypothesis of dual disintegration was primarilybased,49 and it has not yet been possible to establish experimentallysuch a variation.Some interesting experiments have been carried out on thevolatility of thorium-D, showing that the substance, after treat-ment with hydrochloric acid, commences to volatilise at 270°, andis completely volatilised below 500°, whereas the untreated sub-stance commences t o volatilise a t 520° and is completely volatiliseda t 700O.Using the volatility as a test of the s t a b in which thethorium-D was present, the conclusions were drawn that i t recoilsin atomic form from the active deposit which has been treatedwith hydrochloric acid. On the other hand, if obtained by heat-ing the active deposit so treated, it volatilises as chloride a t theAnn. Beport, 1912, 312RADIOACTIVITY, 289lower temperature, showing that in this case combination withchlorine must occur after its production.50Appearance of Helium and Neon in Gases Subjected to t h eElectric Discharge.Numerous experiments, on the same lines as those detailed irrlast year’s Report,51 have been carried out on the presence of tracesof helium and neon in gases subjected t o the electric discharge,and the balance of the evidence appears to be against the viewthat these gases are transmutational products, although much, nodoubt, remains to be explained concerning their apparentlycapricious appearances and non-appearances.Sir J. J. Thomson,whose experiments, criticised here last year, have frequently beenquoted in favour of the view that the appearances are significant,himself now states: “I have never, however, been able to get anyevidence, that I regard as a t all conclusive, that the atom of oneelement could by such means be changed into an atom of adifferent kind; in other words, that by such means we could pro-duce a transmutation of the elements.”62Merton 53 used a tap-free apparatus, essentially identical withone used by the writer in similar kind of work many years ag0.5~Hydrogen, admitted by heating, with a flame, a palladium tubesealed to the apparatus, was subjected t o a heavy discharge, andthen removed by heating the palladium tube with a glowing spiralof platinum wire.When the apparatus was clean, no trace ofargon, neon, or helium was obtained.Minute amounts of argonappearing in the earlier experiments were traced to minute leakageof air, due to a small amount of dirt in the barometric seal. Airwas also found to leak through stopcocks which had every appear-ance of being trustworthy. It is considered doubtful by thisauthor whether stopcocks can be trusted in dealing with suchminute quantities of gases.These results, therefore, are t’o be ranged with those of Strutt,obtained last year, against the view that helium and neon areobtained when due precautions are taken to avoid contamination.Merton’s apparatus was subsequently handed over to Collie,55 whoused it, in conjunction with a cold charcoal apparatus, to demon-strate that uranium gives off, by bombardment with cathode rays,Compare Ann.j0 A. B. Wood, Phil. May., 1914, [vi], 28, 808 ; A . , 1915, ii, 5.51 Ann. Report, 1913, 284.52 Sir J. J. Thomson, Romaneq Lecture, 1914, p. 18.B3 T. R. Mertoii, Proc. Roy. Xoc., 1914, [ A ] , 90, 549 ; A,, ii, 726.j4 F. Soddy aud T. D. Mackenzie, ibid., 1908, [ A ] , 80 92.55 J. N. Collie, ibid., 1914, [ A ] , 90, 554; A . , ii, 727.Report, 1912, 318.REP.-VOL. XI. 290 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.considerable amounts of nitrogen, helium, and neon, althoughnone could be obtained from the uranium by heating. Howeverinteresting such observations may be, they seem confusing t o thepoint a t issue. Deliberately t o put a radioactive source of heliumint,o such an apparatus is simply to spoil the apparatus for thequestion it was designed to test.For, in the writer’s experience,once helium has been used in a discharge apparatus, ever after-wards helium, of the order of magnitude under consideration, maybe obtainable from that apparatus.I n a paper 513 entitled (‘ The Production of Neon and Helium bythe Electric Discharge,” fuller details are given of the experi-mental apparatus by which the previously published results, dis-cussed a t length last year, and some new ones, were obtained,together with a r6sum6 of the results and a discussion of thesources of the gases in question. Many of these experiments alsogave negative results, but the account deals mainly with those thatgave positive results. Apparently, latterly, difficulty has been ex-perienced in obtaining such large yields of helium and neon asformerly, and this is ascribed to’ differences in the interruptersemployed with the coils.A wide diversity of apparatus was used.I n some, transference of gas from the discharge apparatus t o thetesting apparatus was avoided. Electrodes of various metals wereemployed, and in many experiments helium and neon were found,in spite of all precautions t o ensure the purity of the gas and toeliminate air-leakage. Thel absence of argon was considered tobe an extremely delicate proof that the neon and helium foundwere not derived from the air.New experiments with a silica-tube mercury arc apparatus, inwhich considerable quantities of helium and neon were found afterrunning the arc in air, pointed t o the atmosphere in this case asthe source of the gases, for, with the apparatus water-jacketed, nohelium or neon was obtained even after protracted running.Hydrogen, when introduced, disappeared rapidly during the dis-charge, leaving no gaseous residue.Arguments are advanced against the helium and neon in theearlier experiments having been derived from leakage of air, bypermeation through the walls of the discharge tubes, or by previousocclusion of the gases in the materials of the discharge tube, andnegative results were obtained when old glasses were melted in avacuum and when aluminium electrodes were dissolved.Theauthors disclaim the view that th& experiments rigidly excludethe possible sources of the gases discussed, but conclude “that the56 J.N. Collie, H. S. Patterson, and I. Massou, €‘roc. Boy. Soc., 1914, [ A ] , 91,30 ; A., ii, 847RADl OACTLVITY. 291trend of the results is towards conclusions which, if they turn outto be true, would be of very obvious importance.” Clearly, how-ever, the onus of proof now rests with them to show that theseinfinitesimal quantities of helium and neon have a real significance.It is noteworthy, also, that in some of these later experiments thequantities of the gases in question observed must have been ex-tremely near the limit of detectability, for in criticism of Strutt’snegative results, the authors state that they have found i t necessarythat the capillary tubes, used to detect the gases spectroscopically,must, to be sufficiently sensitive, be so fine that mercury can onlybe driven out of them by strong heating: yet the spectrcscopic testfor neon and helium is excsssively delicate.A c t i o i ~ of Radium O ) L t h e Diamond: Chemical A c t i o m .I n a record of various experimentsy extending over a long termof years, on the action of radium on various substances, andespecially on the diamond, some observations were made whichindicate considerable differences between the diamond arid othermaterials rendered radioactive by exposure t o the radium emana-tion.57 First may be mentioned the absence of any trace of radio-activity in a yellow, phosphorescent diamond, which during fortyyears had been used in a Crookes’ tube to show the phosphorescenceproduced by cathode rays.No coloration was produced in adiamond exposed for six months to the P- and y-rays from a sealedtube containing 15 milligrams of radium bromide, but, when sub-jected to the a-rays and emanation by being enclosed in a tubecontaining radium bromide for seventy-eight days, i t acquired abluish-green colour and an enduring radioactivity, comprising a-and P- and y-rays. Such acquired radioactivity, which i t wouldbe natural t o ascribe to radium-l), -E, and -F, proved extra-ordinarily enduring after drastic chemical treat.ment. Neither thecolour nor the activity was affected by prolonged treatment witha hot mixture of fuming nitric acid and potassium chlorate,whereas lead glass which had been rendered active by beingburied for a long period in a radium preparation lost nearly allthe acquired activity by treatment with dilute nitric acid.Cutting the diamond into a brilliant completely removed both theactivity and the colour.Another difference between the diamond and a quartz crystal,for example, rendered active by prolonged contact with a radiumpreparation, was shown in the image produced when laid on asensitive plate. The latter showed the ordinary image of geo-5i Sir \V. Crookts, Phil. T?ans., 1914, [ A ] , 214, 433.u 292 ANNUAL 1tEPORTS ON THE PROGRESS OF CHEMISTRY.metric pattern, due to the superficial deposit of active matter andthe equality of the intensity of the rays in all directions, studiedby Rutherford. I n the case of the diamona, however, the photo-graphs suggested a special discharge of energy from the points andcorners of the crystal. It is not explicitly recorded what precau-tions were taken against phosphorescent light emitted by thediamond to exclude it from contributing to the action.With regard to the very interesting peculiarity shown by thediamond in retaining its activity after drastic chemical treatment,short of supposing a real stimulation of the diamond into1 radio-activity, which would be a phenomenon of an entirely new andrevolutionary character, and is not suggested, possibly the surf aceof the diamond possesses for radium-B and its products a specialattraction, analogous to that shown by palladium for poloniurn.58The subject opened out is new and very attractive.During the year, the decomposition of ammonia,5Q the combina-tion of hydrogen and oxygen,Go and the reduction of carbon mon-oxide by hydrogen61 under the influence of radium emanationhave been studied. I n the latter research, a diminution of volumeof nearly 10 per cent. occurred after nineteen days, correspondingwith a production of methane to the extent of 5 per cent., andethane 0.12 per cent. When stopped at an earlier stage, traces offormaldehyde were found, and the conclusion is drawn that thereaction occurs in two stages, formaldehyde being an intermediateproduct.PREDEI~ICK SODDY.58 Ann. Report, 1913, 274.59 E. Wourtzel, Compt. rmd., 1914, 158, 571 ; A . , ii, 238.6o 0. Scheuer, ibid., 159, 423; A . , ii, i 6 2 .Idem., ibid., 158, 1887 ; A . , ii, 649

ISSN:0365-6217    

DOI:10.1039/AR9141100266

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

INDEX OF AUTHORS‘ NAMES.Abderhalden, E., 82, 198, 199, 200, 201Abram, H. H., 17.Allen, E. T., 260.Allen, H. C., 174.Allmand, -4. J., 31.Andersen, O., 254.Anderson, R. P., 38.Andrada, E. N. da C., 275.Andrews, L. W., 168.Aoyama, S., 59.Amenrodt, J., 109.A4pplebey, ‘M. ‘P., 10.Ark, H., 70.Armstrong. E. F.. 190. 193. 195.Armstronii H. E.’, 21,’67, 82, 190, 193,194, 195, 252.Arnold, H., 172.Arrhenius, S., 26, 29.Aten, A. H. W., 40.Auwers, K.. v., 100, 112, 133.Baeyer, 0. von, 282.Bahlmann, C., 185.Bainbridge, E. G., 79.Baker, H. B., 38, 49.Baker, J. L., 93.Bannister, C. O . , 171.Barendrecht, H. P., 195.Barlot, J., 57.Rarlow, W., 239, 244, 251.Barnebey, 0. L., 169.Bassani, E., 200.Bassett, H., jun., 52.Bastet, M., 105.Bauer, E., 145.Bauermeister, M., 128.Bayliss, W.M., 189.Becker, P., 135.Bedford, Duke of, 220, 231Beer, R., 129.Beesley, R. M., 224.Belasio, R., 169.Benedict, S. R., 206.Benjamin, M. S., 193.Bergoe, E., 52.Bezssonoff, 140.Biltz, H., 153.Bingham, E. C., 162, 163.Bizzell, J. A., 181,Blacher, C., 184.Blaise, E. E., 74, 119.Rlanck, E., 235, 236.Blum, W., 54.Blumenfeld, J., 38.Bodlander, E., 54.Boeseken, J., 105.Bomer, A., 179.Bohr, N., 5.Boon, A. 9., 131.Born, S., 195.Borsche, W., 118.Bose, E., 239, 263, 265.Boswell, M. C., 175.Bosworth, A. W., 183.Bottomley, W. B., 232.Bourquelot, E., 88, 189, 190.Bowen, N. L., 239, 253, 254.Bowowska, H., 142.Bradshaw, L., 33.Bragg, W. H., 238, 240, 242, 243.Rragg, W.L., 238, 243, 245.Rrandt, L., 168, 169.Braun, H. J., 61.Braun, J. von, 151.Brauns, F., 64.Brenchley, W. E., 233.Bridel, M., 88, 190.Rridgman, P. W., 39, 257.Brieger, R., 126.3roglie, IT. de, 242.Srown, H. T., 181.3ruhat, G., 22.3runck, O., 170, 173.3uckborough, S. A., 93.3uddin, W., 219.3iihn, T., 176.3unbury, H. M., 73.hrgess, G. K., 171.29294 INDEX OF AUBurgess, P. S., 223, 226.Burrell, G. A., 165.Burrows, G. J., 94.Burton, D., 70.Busch, M., 175.Buskirk, van, 186.Cain, J . C., 106, 107, 108.Cain, J. R., 173.Calhane, D. F., 173.Campbell, E. D., 171.Carney, R. J., 171.Cesarie, M., 90, 150.Chadwick, J., 281.Chapman, D. L., 11.Charitschkov, K. V., 174.Chattaway, F. D., 80.Chauvenet, E., 57.Chlopin, W., 162.Clarke, L., 116.Clemmensen, E., 123.Clewer, R.W. B., 90, 150.Clibben, D., 89.Clough, G. W., 67.Cohen, E., 40.Cohen, L., 176.Cole, H. I., 166.Coleman, F. C., 30.Colgate, R. T., 252.Collie, J. N., 35, 42, 43, 44, 46, 289,Contardi, -4., 99.Cooper, E. A., 211.Coppin, N. G. S., 95.Cordier, V. von, 96.Cornubert, R., 117.Coward, H. F., 33.Cramer, B. J., 164.Crenshaw, J. L., 260.Crofts, J. M., 33.Crookes, (Sir) W., 291.Crossley, A. W., 112.Cruikshanks, G. S., 110.Cullen, G. E., 191, 193.Cunningham, A., 222.Cunningham, (Miss) M., 178.Curie, M., 37, 268.Curme, G. 0.. 87.Curtis, R., 118.Curtis, W. E., 7.Daikuhsra. G.. 214.290.Daish, 9. .:J., 92, 182, 237.Dakin, H. D., 78, 176.Danckwortt.P. W.. 168.Darwin, C. ’G., 274.’Davis, M., 210.Davis, P. B., 28.Davis, V7. A . , 92, 182, 237.Datta, R. L., 178.Dawson: H. M., 70.Decker, F., -141.IOHS’ NAMES.Decker, H., 135, 149.Denham, W. S., 93.Denis, W., 208.Dennis, L. M., 38.Derby, W. B., 183.Dessauer, F., 277.Dewey, F. P., 168.Dickson, T. W., 15, 16, 19, 20.Dieckmann, W., 122.Diedrichs, A., 179.Dittoe, 186.Dixon, H. B., 33.Dobbie, J. J., 151.Dole, R. B., 187.Domcke, E,, 47, 48, 49.Donnan, F. G., 31.Dorke, C., 178.Dormann, E., 157.Drapier, N., 54.Drugman, J., 250.Drummond, J. C., 211.Dubsky, J. V., 163.Ducelliez, F., 113.Dudley, H. W., 78, 176.Dupont, G., 80.DuprB, H. A., 181.Du Vergier, E. A., 171.Eastman, D., 183.Eberlein, W., 118.Eck, J.J. van, 185.Eegriwe, E., 166.Egerton, A. C. G., 58.Eichwald, E., 82.Eismayer, K., 156.Ellms, J. W., 186.Elod, E., 48.Endell, K., 259.Erlenmeyer, 68.Esselen, G. J., jun., 116.Euston, E., 56.Everest, A. E., 135, 140.Ewald, G., 198. 199.Ewald, P. P., 245, 247.Fajans, K., 267, 270, 285.Farbenfabriken vorm. F. Bayer & Co.,Farbwerke vorm. Meister, Lucius, &149.Briininz. 149.Fargher,R. G., 73.Fawsitt C. E., 94.Fedoro;. E. S.. 238. 246. 248. 249. < , , , Feist, F:, 95.Feist K., 91.Fendier, G., 179.Fenner, C. N., 239, 258.Fenton, H. J. H., 175.Fernandes, F. V., 95.Ferry, E. L., 210INDEX OF AUTHORS’ NAMES. 295Feulgen, R., 88.Fischer, E., 64, 75, 86, 87, 89, 90, 97,152.Fischer, H., 145, 156, 158.Fischer, H. 0.L., 75.Fischer, K., 179.Fischer, O., 114, 152.Flatow, L., 201.Fodor, K. von, 87, 89, 152.Foppl, L , 244.Folin, O., 208.Forster, R. B., 123.Fosse, R., 178.Fourneau, E., 148.Fowler, A., 7.Fox, J. J., 151.Franke, A., 79.Frankel, E. M., 203, 204.Frankforter G. B., 105, 176.Frankland, k. F., 19, 24, 64.Freudenberg, K., 65.Friedel, G., 241, 262.Fiirth 0. von, 202.Fuhr;r, K., 116.Funk, C., 210, 211.Fyfe, A. W., 89, 121.Gadamer, J. 148.Gainey, P. d., 222.Gallo, G., 52.Garrett, C. S., 89.Gaudefroy, C., 52.Gay L., 113.Geake, A., 90, 97.Geake, J. J., 169.Gelin, E., 169.Germann, A. F. O., 37.Gessner, H., 62.Ghosh, B., 147.Gibbs, I. R., 111.Gilmour, R., 83, 116.Giran, H., 61.Gohring, C., 286.Gohring, O., 109.Goldschmiedt, G., 176.Goldsworthy, L.J., 117.Gomberg, M., 108.Gonnelli, F., 175.Gooch, F. A., 166, 167.Gosney, H. W., 82.Gossner, R., 251.Goubau, R., 174.Grabowski, J., 155.Gravenitz, R. von, 97.Graham, J. I., 164.Grandjean, F., 262.Grandmougin, E., 131.Greaves, J. E., 225.Green, G. hl., 31.Green, H H., 224.Greenwald, I., 203.Grey, E. C., 175.Griffiths, E., 4, 5.Griffiths, E. H., 4.Grigorescu, L., 201.Groth, P., 247.Grube, G., 183.Griinberg, P., 184.Griittner, G., 127.Hagglund, E., 176.Hahn, A., 154.Hahn, O., 282.Halla, F., 62.Haller, A., 117, 145.Hanley, J. A., 218, 237.Hanzawa, J., 235.Harden, A., 92.Harries, C., 72.Harris, J. E., 216.Hartley, H.B., 101.Haun, H., 91.Hauptmann, A., 201.Hauser, S. J., 186.Haworth, W. N., 88, 121.Hayden, E. M., jun., 172.Heilbron, I. &I., 131.Heimrod, G. W., 97.Heinze, R., 163.Helderman, W. D., 40.Helferich, B., 89, 152.Herold, P., 68.Hess, K., 144, 146, 150.Hevesy, G. v., 284.Hewitt, J. T., 103.Hicks, W. M., 281.Hildebrand, J. H., 183.Hilditch, T. P., 24.Hilgendorff, G., 68.Hill, ,4. J. 96.Hilpert, S.,’127.Hodgkinson, W. R. E., 58.Honigschmid, 0. 37, 268, 271.Hofmann, K. A.; 61.Hogan A. G., 202.Hogg, ’T. P., 67.Hollandt, P., 184.Hollely, W. F., 103.Holmes, A., 28, 270.Holt, A., 62.Horovitz, (Mlle.) S., 37, 268.Horton, E., 193.Hottenroth, V., 176.Hubbard, P. L., 166.Hudson, C. S., 92.Hiillweck, G., 89.Hughes, H.28.Hulett, G. k., 38.Hulme, W., 225.Hulton, H. F. E., 93.Huntly, G. N., 164.Hutchinson, H. B., 181, 221, 223, 237Hyman, H., 35, 36, 266.Hynd, A., 89296 INDEX OF AUTHORS’ NAMES.Iljin, L. F., 91.Iucitsch, S. I., 71, 79, 80.Irschick, A., 100.Irvine, J. C., 67, 83, 85, 89, 91.Ishiguro, 198.James, C., 171.Jamieson, G. S., 172.Johnson, T. B., 96.Jones, B. M., 57.Jones, H. C., 28.Jones, (Miss) M., 180.Juritz, C. F., 214.Kalandyk, S. J., 31.Kalb, L., 115.Kappen, H., 222.Kay, F. W., 121.Kelley, W. P., 218, 220, 226.Kendall, J., 9, 26, 131.Kenner, J., 107, 117, 118.Kenyon, J., 16, 20, 23, 24, 25, 66.King, H., 81.Kirchhoff, G., 127.Kirpal, A., 176.Kissa, ill., 184.Klaeser, M., 226.Klemenc, A., 102.Klemensiewicz, Z., 285.Kling, A., 169.Knoevenagel, E., 113.Kohler, J., 110.Koenig, A., 48.Konig, E., 114.Korner, W., 99.Kotz, A., 115.Komppa, G., 120.Kraus, C.A., 25, 27.Kritchevsky, W., 105.Kriiger, J., 183.Kiister, W., 153 157.Kumagai, T., 2d0, 201.Kuss, E., 53.Kuzirian, S. B., 167.Laar, J. J. van, 12.Lamble, A., 76.Lander, G. D., 169.Landsberger, F., 68.Langel, J., 183.Lapworth, A., 180.Lasch, G., 129.Latshaw, W. L., 182, 183.Laue, M., 242.Lawson. R. W.. 270.Leathe;, J. W. ,’ 179.Lebedev, S. V., 71, 72, 73.Le Blanc. M.. 49.Leduc, A:, 38.’Leech, P. N., 112.Lefort, G., 228.Lehmann, C. B. A., 132Lehmann, F., 168Lehmann, O., 239, 260, 261.Lembert, hl. E., 35, 36, 267.Lenhardt, S., 100.Leskiewicz, J., 141.Lespieau, R., 80.Letts, E.A., 237.Leuchs, H., 151.Levene, P. A., 204.Levinstein, H., 131.Lewis, E. A., 173.Lewis, T.V. C. M., 14, 76.Lewis, JV. L., 93.Limprich, R., 179.Lind, S. C. 286.Ljngen, J. 8. van der, 242.Lipman, C. B., 223, 226.Lipp, P., 119, 120.Lohnis, F., 222.h e w , O . , 217.Lorenz, E., 31, 261.Losanitsch, M,, 110.Lowry, T. M., 15, 16, 17, 19, 20, 25Lubrzynska, (Miss) E., 204.Lutzendorf, G., 128.Lundie, M., 236.Lynde, C. J., 181.Lyon, T. L., 181.Maass, E., 149.Nacallum, A. B., 210.McBain, J. W., 30, 74.McBeth I. G., 225.hIcColl;m, E. v., 210.McGeorge, W., 220.BlcKenzie, K. J., 131.MacLean, (Mrs.) I. S., 204.Maclennan, K., 181, 221, 237.Madelung, W., 131, 146.hIahin, E.G., 54.Mailhe, A., 78, 113.Malarski, H., 144.Malatesta, G., 166.Mallison, H., 134, 138.Malpeaux, L., 228.Mameli, R., 145.Manchot, W., 58.Mann, (Miss) G. R., 103.Manning, R . J., 176.Marchlewski, L., 141, 142, 144, 155.Marcus, E., 108.Xarcusson, J., 181.hfarino, L., 175.Marriott, W. M., 205.Marsden, E., 274, 287.Marshall, E. K., 194.Martin, H. E., 73, 74.Masson, I., 35, 44, 46, 290.Masters, (Miss) H., 185.Rlathews, (Miss) A. M., 107.bfau, W., 60.48, 66INDEX OF AUTHORS' NAMES. 297Mauguin, C., 239, 262, 265.Meerwein, H., 119.Meggitt, A. A., 216.Meissner, S., 151.Meitner, L., 282.Meldola, R., 103.Mellanby, J., 197.Mendel, L. B., 210.Menschutkin, B. N., 105.Mereshbowski, B. K., 70, 71, 72, 73.Merton, T.R., 42, 289.Merwin, H. E., 260.Meyer, G. M., 204.hleyer, H., 129.Meyer, K. H., 69, 100.RIeier; R. J.,'54.'Michael, A., 109.Michaelis, F., 100, 112.Michaelis, L., 86, 195, 196.Micklethwait, (AIiss) F. I f .btilchsack, C., 175.Miller, F., 221.Miller, J., 186.Miyake, K., 235.Morey, G. W., 50.Morrell, G. F., 74, 75.Morton, A., 121.hloseley, H. G. J., 278.Rloser, L., 165.Moulton, C. R., 181.Mumfod, E. M., 223.Mummery, C. S., 252.Murat, M., 113. 115.Nametkin, S. S., 69.Nef, J. U., 84.Nelson, J. M., 195.Nernst, W., 5.Neumann, B., 52.Newbery, E., 32.Nicholson, J. W., 8, 281.Nicolet, B. H., 96.Nierenstein, M., 90, 97, 176.Nissen, F., 95.Nockmann, E., 184.Nola, E. di, 166.107, 108Oba, S., 277.Oddo, B., 145, 155.Oddo, G., 90, 150.OdBn, S., 218.Osterber , E., 206.Oesterhefd, G., 173.Ogawa, M., 59.Ogorodnikov, A., 18.Oliver, T.H., 174.Olivier, S. C. J., 104.Onnes, H. K., 5.Osborne, T. B., 210.Oswald, M., 51.Ott, E., 76, 77.G., 106,Page, H. J., 144, 148.Paine, H. S., 92.Paneth, F., 284.Parker, L. H., 123.Parnas, J., 202.Patchin, 171.Paternb, E., 152.Paterson, (Miss) 13. M., 83, 85.Patterson, H. S., 35, 44, 46, 290.Patterson, T. S., 19.Pauly, H., 116.Pechstein, H., 196.Pelt, C. van, 169.Perkin, W. H., jun., 68, 73, 99, 114,Perkins, P. B., 286, 287.Peterson, W., 227.Petherbridge, F. R., 220.Petit, G. H., 166.Pfeiffer, T., 235, 236.Pflanz, VC'., 184.Pickard, R . H., 16, 20, 23, 24, 25, 66.Pickering, S.P. U., 220, 231.Pieroni, 9., 70.Piloty, O., 157.Pincussohn, L., 198.Plancher, G., 145.Pohl, P., 133.Polack, W. G., 54.Pond, F. J., 71.Pope, F. G., 103.Pope, W. J., 64, 239, 251.Postma, S., 58.Potnieiil, R., 177.Power, F. B., 90.Praetorius, P., 55.Prianischnikov, D., 230.Prscheborovski, J., 29.Pyman, F. L., 81.Qua, N. C., 105.Raffo, M., 146.Rauch, H., 151.Ravenna, C., 145.Rly, P. C., 95.liaynaud, A., 113.Rea, (Miss) F. W., 237.Read, J., 64.Reckert, I?. C., 167.Reinders, W., 51.Reissert, A., 131.Remmert, P., 132.Renouf, (Miss) N., 112.Richards, E. H., 236.Richards, T. W., 11, 35, 36, 239, 251,Richardson, €3. Y., 173, 174.Richardson, H., 275.Riesenfeld, E. H., 60.Ringer, ,4. I., 203, 204.Ritter, K., 61.117.267298 INDEX OF AIJTHORS’ NAMES.Roberts, W.M., 114.Robertson, P. W., 111.Robinson, H., 272, 275.Robinson, R., 99, 114.Rodd, E. H., 252.Rohmann, J?., 201.Rose, H., 145, 156, 158.Rohde, G., 151.Rona, P., 196, 205.Rdrdarii H. N. K., 131.Rose, T . K., 170.Rose, W. C., 210.Rosenheim, O., 90.Ross, J. D. M., 94.Rossi, G., 146.Roth, W. *4., 175.Rothe, O . , 64.Rubidge, C. R., 105.Rudnick, P., 182, 183.Riidiger, A., 142.Ruff, O., 61.Rule, .4., 50.Rupe, H., 24.Russell, E. J., 219, 220, 223, 229, 236.Rutherford, (Sir) E., 5, 272, 273, 274,Rydberg, J. R., 281.SabanQev, A. P., 60.Sabatier, P., 78, 113, 115.Sachanov, A., 29.Sackett, W. G., 227.Sale, P. I]., 171.Salway, A. H., 90.Schaeffer, E., 115.Scheiber, J., 68.Scheuer, O., 292.Schlenk, W., 108, 109.Schlosser, H., 100.Schmid, O., 165.Schneider, W., 89.Scholler, M.R., 109.Schonborn, (Count) E. von, 211.Schonburg, C., 109.Scholtz, M., 146.Scholze, E., 180.Schreiner, 0.) 219.Schulemann. W., 126.Schwaebel, G., 151.Schwenketi, F., 203.Schwers, E., 5.Schwyzer, A., 110.hhor, J., 143.Seibert, F. M., 165.Seidell, A., 164.Sen, K. B., 134.Senft, E., 143.Senier, A., 123.Seyder, P., 131.Shedd, 0. &I., 235.Shorey, E. C., 218.Shrimpton, A. G., 38.275, 276, 282.Shutt, F. T., 214.Sieverts, A., 62, 173.Simmonds, C., 179.Simonis, H., 132.Sinnatt, F. S., 164.Skinner, J. J., 219, 234.Slade, R. E., 54.Slawik, G., 170.Slyke, D.D. van, 191, 193.Smiles, S., 147.Smit, J., 177.Smith, H. L., 185.Smith, N. R., 225.Smith, T. O., 171.Smits, A., 58, 257, 259.Soddy, F., 35, 36, 266.Soderbaum, H. G., 237.Sommer, F., 59.Spallino, R., 179.Sprinkmayer, H., 179.Stadler, G., 95.Stan&k, V., 178.Stark, J., 7.Staudinger, H., 109.Steibelt, W., 89.Steimmig, G., 72.Steinkopf, I&’., 127, 128.Pteinmetz, H., 251.Sterba-Bohm, J., 54.Stewart, R., 227.Stieglitz, J., 112.Stobbe, H., 109, 110.Stock, A., 53, 55.Stock, J., 157.Stoklasa, J., 143.Ftoll6, R., 132.Strufe, K., 153.Strutt, (Hon.) R. J., 42, 47, 49.Stuart, J. M., 101.Stiiber, W., 179.Stutzer, A., 183.Suleimann, A., 167.Sullivan, M. X., 234.Szmidt, (Miss) J., 284.Tammann, G., 256, 257.Tanret, C., 93.Taylor, A.E., 210.Taylor, G. B., 38, 165.Taylor, H. S., 52.T e m p h , H. G., 59.Thal, A., 109.Thiel, A., 62.Thomas, J. S., 50.Thomson, (Sir) J. J., 46, 272, 289.Thomson, R. F., 89.Thornton, W. M., jun., 172.Thorpe, (Sir) T. E., 181.Tiede, E., 47, 48, 49.Tiffeneau, If., 116.Titherley, A. W., 95.Tonnioli, E., 70ISDEX OFTowara, H., 285.Traube, W., 59.Trotter, J., 131.Trowbridge, P. F., 181.Tschilikin, M., 131.Tschugaev, L. A., 17, 18, 162.Tubandt, C., 31, 261.Tutin, F., 90, 150.Twitchell, E., 180.Tyrer, D., 10, 12.Urbain, G., 38.Varder, R. W., 287.Vecchi, G., 141.Veen, A. L. W. E. van der, 245.Vernon, H. M., 197.Vesely, V., 88.Villiers, A., 170.Vockerodt, O., 59.Voelcker, J. A., 234, 236.Vorlander, D., 239, 263.VotoEek, E., 88, 110, 177.Waals, J. D. van der, 12.Wager, H., 143.Wagner, H. E., 131.Wagner, R., 202.Wahl, W., 250.Walden, P., 29, 31.Walker, E. E., 21, 67.Walpole, G. S., 30.Warner, C. H., 144.Warynski, T., 183.Wassjuchnov, A.. 54.Watanabe, R., 198.U7atson, E. R. 102, 133, 134.Watson, W. d., 38.Wegelin, G., 173.Weibull, M., 229.Weller, J., 157.Welsbach, C. A. von, 38.Wenzel, F., 129.Werner, E. A., 94.Wertheimer, P., 69, 100.AUTHORS’ NAMES.Wewerinke J., 179.Wheaton, d?. C., 173.White, W. P., 252.Whittemore, C. F., 286.Wibaut, J. P., 165.Wiesner, G. H., 214.Wightman, E. P., 28.Wildermuth, F., 201.Wilenko, G. G. 205.Will, G., 116.Will, W., 99.Willfroth, E., 55.Willson F. C., 69.Willstdter, R., 134, 135,Wilson, C. T. R., 259.Wilson, F. J., 131.Wilson G. W., 220.Wilson: R. H., 287.Wilson, S. R., 169.Winkler, L. W., 185, 187.Winmill, T. F., 164.Wippelmann, W. 173.Wissing, F., 144,’ 146.Witzemann, E. J., 78.Wolf, G., 62.Wolf, J., 54.Wolff, H., 180.Woodhouse, (Miss) H., 93.Woolley, V. J., 197.Worley, R. P., 14.Wourtzel, E., 292.Wrede, F., 89.Wunder, M., 167.Wood, .A. B., 287, 289.wood, J. K., 96.Young, C. R., 75.Young, W. J., 92.Zablinski, K., 149.Zacharias, G., 194.Zambonini, T., 145.Zimmermann, W., 156.Zink, J., 184.299, 144

ISSN:0365-6217    

DOI:10.1039/AR9141100293

出版商:RSC    

年代:1914

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Acetone, estimation of, 176.Acetylene, halogen derivatives of, 71Acid residues, migration of, 111.Acids, aliphatic, 73.Agricultural analysis, 181, 237.Alcohols, polyhydric, 79.Aldehydes, 78.Algae,. pigments of, 144.Alkali silicates, 50.Alkaloids, 148.estimation of, 174.Allotropy, 39.Aluminium compounds, 54.detection of, 166.commercial, analysis of, 169.Amidosulphinic acid, 59.Amines, action of nitrous acid on, 15CAmino-acids, 96.Ammonia, liquid, solution of metalhydrates of, 58.Ammonification, 223.Ammonium citrate, preparation of solutions of, 182.Analysis of gases, 164.agricultural, 181, 237.crystallo-chemical, 248.electrochemical, 173.inorganic, 165.microchemical, 163.organic, 174.Anisotropic liquids, 260.Anthanthrone, 115.Anthocyanidins, 137.Anthocyanins, 135.Antiseptics, action of, on soils, 219.Aromatic compounds, change of hydro-aromatic compounds into, 112.Arsenic, estimation of, 168.Asphaltum, analysis of, 181.Asymmetric induction, 67.fatty, estimation of, 180.condensation of phloroglucinol ant129.in, 25.Atom, energy of an, 3, 4.Atomic weights, 35.Atoms, structure of, 5.Azo-compounds, 100.Azoimidesulphonic acid, salts of, 60.Barlow-Pope theory, 251.bases, tertiary, fission of, 116.Beckmann rearrangement, 112.Beef-fat, estimation of, in lard, 179.Beer, determination of the originalBeet molasses, estimation of, 178.Benzene, bromination of, 113.Benzene ring, rupture of the, 116.Benzhydrol, 115.Benzoterpenes, 121.Bile, pigments of the, 158.Bilirubin, 159.Binary system, MgO-SiO,, 254.Blackberry, see Rubus discolor.Bleaching powder, 61.Blood, colouring matter of the, 153.Bomn compounds, 53.Bromine, estimation of, 166.gravity of, 180.hydrate, composition of, 61.Cadmium, allotropy of, 40.Caffeine, estimation of, in coffee, 179.Calcium salts, 52.Camphenic acid, synthesis of, 119.Cantharidin, 148.Caoutchouc, 71.Carbamide, estimation of, 178.Carbamides, 94.Carbohydrates, 84.metabolism of, 202.Carbon monoxide, estimation of, 164.sulphido-telluride and -selenide, 55.estimation of, in iron and steel, 172.See also Diamond.Carbon rings, formation of, 117.Carbonyl group, reduction of the, 123INDEX OF SUBJECTS.Catalysis, 33.Catalytic reactions, 113.Chemical constitution, relation ofcolour and, 102.China green, 142.Chlorophyll, 142.Cinnamic acid, optically active formsCinnamic acids, 109.Citric acid, ammonium salt, prepara-Cobalt, estimation of, 170.Colour, relation of constitution and,relation of tautomerism and, 103.Colouring matters, natural, 135, 140,quercetin group of, 133.Compressibility of liquids, 12.Condensation, 109.Copper, structure of, 243.allotropy of, 40.atomic weight of, 38.detection of, 166.Coumarin, synthesis of, 129.Creatine, metabolism of, 206.Creatinine, 209, 210.Cristobalite, 258.Crocetin, composition of, 141.Crystals, liquid, 260.Crystal structure, X-ray methods ofCrystallo-chemical analysis, 248.Cyanamide, estimation of, 183.Cyanidin, 136.Cyanin, 135.Cyclic compounds, formation of, 118.Datiscn cannabina, pigments of, 141.Delphinin, 136.Denitrification, 223.Diamond, structure of, 243.action of radium on the, 291.Diazophenols, 102.Dimethylpyrone, derivatives of, 130.Dinaphthathioxonium salts, 147.Diopside, the system, forsterite, silica,and, 254.Diphenyl series, 106.Disaccharides, 92.Disintegration series, 285.Dispersion, rotatory, 14 e t sep.Drude’s formula, 15.Electric discharge, 41.Electrical conductivity, mechanism of,by enzymes, 189.of, 68.tions of solutions of, 182.102.141, 142, 144.exploring, 240.symmetry, 249.containing mercury, 126.25.of salts, 31.potential, 31, 32.Electrochemical analysis, 173.Elements, spectra of the, 5, 8.1-ra.y spectra of the, 277.Energy of an atom, 3, 4.Enzymes, catalysis by, 189.tissue, specificity of, 197.Equilibria, ionic, 31.Esterification, 123.Esters, 76.Ethyl alcohol, estimation of water in,180.Fats, metabolism of, 202.Fatty acids, estimation of, 180.Ferments, defensive, 199.Ferropyrroles, 155.Flavones, 132.Flavonols, 132.Fluorosulphonic acid, 61.Fluorspar, structure of, 246.Formic acid, estimation of, 176.Forsterite, the system, diopside, siIica,Friedel and Crafts’ reaction, 104.Fusarium orobanchus, pigments of,and, 254.140.Gas analysis, 164.Gases, chemical reactions in, 33.Glucinum, estimation of, 169.Glucosides, 88.Glutaconic acid, ethyl ester, cycliccompounds from, 118.Glyceraldehyde, preparation of, 78.Glycerides, 82.Glycerol, interaction bf oxalic acidGlycerylphosphoric acid and its salts,Grignard‘s reaction, 110.and, 80.81.Haematic acid, synthesis of, 157.Haemin, 153.Halogens, estimation of, in organicHarmine, 152.Hauerite, structure of, 246.Helium, production of, 41 e t seq., 289.Hydrastinine, 149.Hydrazine, estimation of chlorates,bromates, and iodates with, 59.Hydrazinesulphonic acid and its salts,59.Hydroaromatic compounds, change of,into aromatic corn ounds, 112.Hydrocarbons, 70, 12?Hydrogen, spectrum of, 5, 6, 7.compounds, 175.spectrum of, 5, 7.hydrazinesulphonic acid, 59302 INDEX OF SUBJECTSHydrogenation, 113.Hydroxylamineisomonosulphonic acid,Hygrine, 150.59.Indigotin and its derivatives, 131.Intramolecular change, 111.Ionic equilibria, 31.Iridium, estimation of, 170.Iron, estimation of, 169.Iron pyrites, structure of, 246.Isotopes, theory of, 284.estimation of carbon in, 172.Ketones, 78, 114.preparation of 113.action of light on, 152.Lactones, 77.Latent Heat of vaporisation 9.Lead, atomic weight of, 35, 266.from thorium, stability of, 269.carbonates, 56.detection of, 165.Light, ultra-violet, esterification by,Liquid crystals, 260.Liquids, molecular theory of, 263.123.properties of, 9, 14.compressibility of, 12.anisotropic, 260.Lithium, estimation of, 186.Lokao, 142.Magnesium oxide ( m a g n e s i a ) ,system, silica and, 254.Magnetic rotatory dispersion, 66.Magnetic rotatory power, 24.Magneto-optical researches, 265.Maltose, 93.Manganese, separation of, 170.Mannitol, configuration of, 83.Manures.235.estimation of, 176.theMass. conservation of. in radioactivechange, 271.Mercury. atomic weight of, 38.Mercury 'organic compounds; 126.Metabolism, intermediary, 202.Metals, electrical resistance of, 5.solution of, in liquid ammonia, 25.Methoxyl group, estimation of the, 176Methylation, 114.Rfethylcarbonato-acids, 75.Milk, detection of added water in, 178.Minerals, thermal *study of, 252.Molecular symmetry, 249.Morphine, 151.hlyrtillin, 136.detection of, 174.Neon, production of, 41 et seq., 289.density of, 38.Neoytterbium, atomic weight of, 39.Nickel sulphides, 62.estimation of, 170.Nicotine, estimation of, 179.Nitrates, movement of, in soils, 228.Nitration, 99.Nitrification, 223.Nitrites, 51.Nitro-compounds, preparation of, 99Nitrogen, active form of, 47.Nutrition of plants, 235.Oenin, 136.Optical activity, 63.Organic analysis, 174.Oxygen, density of, 37.QzonG, use of, in study of tautomercompounds, organic, 94.oxides, 57, 58.ism, 68.Palladium, sorption of hydrogen by,62.a-Particle, mass and velocities of the,a-Particles, 274.H-Particles, 274.Pelargonin, 136.Perchromic acid and its salts, 60.Phenols, migration of p-halogen atomsin, 111.Phloroglucinol, condensation of aldehydes and, 129.Phosphates, natural, decomposition of,57.Phosphoric acid, estimation of, 166.Phosphorus, modifications of, 39.Phototropy, 123.Phyllocyanin, 144.Phylloxanthin, 144.Pigments, of plants, 135.Plants, nutrition of, 235.pigments of, 135.Platinum, estimation of, 171.Polymorphism, 256.Polysaccharides, 92.?otassium nitrate, 51.Purines, 152.Pyridine as a solvent and catalyst, 146Pyrrole derivatives, 144.Quantum Law, 1.Quartz, 258.Quercetin dyes 133.rsoQuinoline aliraloids, 151.Radioactive change, conservation of272.nitroamino-, 103.mass in, 271INDEX OF SUBJECTS.303Radium, chemical actions induced by,Radium constants, 272.Rain-water, analyses of, 214.P-Rays, connexion between 7-rays and,281.y-Rays, 275.connexion between P-rays and, 281.Reduction, 123.Rhamnose, estimation of, 177.Rharnnus chlorophora, dye from, 142.Rosin, estimation of, 180.Rotatory dispersion, 14 et seq.power, magnetic, 24.Rubu.c discolor, colouring matter of,292.action of, on the diamond, 291.141.Saffron, pigment of, 141.Salts, electrical conductivity of, 31.Scandium, researches on 54.Silica.See Silicon dioiide.Silicates, natural, decomposition of, 57.Silicon dioxide (silica), the system,magnesia and, 254.the system, diopside, forsterite,and, 254.estimation of, 167.Silver, estimation of, 167.Sodium sulphides, 50.Soils, 214.sterilisation of, 219.movements of nitrates in, 228.estimation of the lime requirementsof, 181.Solanine-s, 150.Solids, specific heat of, 2, 5.Solubility, determination of, 161.Solutions, electrical conductivity of, 25,viscosity of, 28.Specific heat, 2, 4, 5.Spectra, line and X-ray, of the ele-ments, 5, 8.Starch, 93.Steel, estimation of carbon in, 172.Stimulants for soils, 230.Strontium, preparation of, 52.28.X-ray, of the elements, 277.estimation of, 182.Strychnine, estimation of, 179.Strychnine alkaloids, 151.Sugars, nomenclature of, 86.Sulphur, allotropic forms of, 40.Tannin, 90.Tautomerism, 68.relation of colour and, 103.Tellurium, atomic weight of, 37.Ternary system, diopide-forsterite-silica., 254.Terpenes, 119.Tetramethylallene, 70,Thermotropy, 123.Thiophen and its derivatives, 127.Thorium, radioactivity of, 286.stability of lead from, 269.estimation of, 271.Tissue-enzymes, specificity of, 197.Titanium, estimation of, 171.Toluene, trinitro-, 99.Toxins, 230.T r iar ylme t hyls, 108,Tridymite, 258.Tungsten, estimation of, 172.Uranium, atomic weight of, 271.Vaporisation, latent heat of, 9.o-Veratraldehyde, nitration of, 99.Viscosity, determination of, 162.Vitamines, 210.Waals’ equation, 11.Water, estimation of chlorine in, 186.estimation of hardness in, 183.estimation of lithium in, 187.estimation of dissolved oxygen in,estimation of, in alcohol, 180.See also Rain-water.185.Water analysis 183.Weights, atorn:c.See Atomic weights.White lead, 56.Wiedemann’s law, 24.Zinc, allotropy of 40.estimation of, 170.Zinc blende, structure of, 245

ISSN:0365-6217    

DOI:10.1039/AR9141100300

出版商:RSC    

年代:1914

数据来源: RSC