摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMISTRYANNUAL REPORTSON THEPROGRESS OF CHEMISTRYF O R 1913.ISSUED BY THE CHEMICAL SOCIETY.tltornmiffet o f @u-blitntioir:H. BRERETON BAKER, M.A., D.Sc.,J. N. COLLIE, Ph.D., F.R.S.A. W. CHOSSLEY, D.Sc., Ph D., F.R.S.F. G . DOSNAN, M . A , Ph.D., F.R.S.BERNARD DYER, D.Sc.M. 0. FORSTEH, D.Sc., Ph.D., F.R.S.F. R. S.T. M. LOWRY, D.Sc.A. MCKENZIE, M.A., D.Sc., Ph.D.W. H. PERKIN, Sc.D;, LL.D., F.R.S.J. C. PHILIP, D.Sc., Ph.D.F. B. POWER, Ph.D., LL D.A. SCOTT, M.A., D.Sc., F.R.S.S. SMILES, D.Sc.&hifor :J. C. CAIN, D.Sc., Ph.D.A. J. GREENAWAY.E. C. C. BALY, F.R.S.T. V. BARKER, M.A., B.Sc.F. G. HOPKINS, M.A., M.B., D.Sc.,J. C. IRVINE, D.Sc., Ph.D.G. CECIL JONES, I?. I.C.F. R. S.N. H.J. MILLER, Ph.D.K. J. P. ORTOS, M.A., Ph.D.G. SENTER, D.Sc., Ph.D.F. SODDY, M.A., F.R.S.A. W. STEWART, D.Sc.VOl. x.LONDON:GURNEY & JACKSON, 33, PATERNOSTER ROW, E.C.1914RICHARD CLAY AND SONS, LIMITED,BRUNSWICK STRFJET, STAMFORD tlTREE'I', S.E. ANDBUNGAY, SUFFOLKCQNTENTS.PAGEGENERAL AND PHYSICAL CHEMISTRY. By G. SENTER, D.Sc., Ph.D. 1INORGANIC CHEMISTRY. By E. C. C. BALY, F.R.S. . . . . 28Part ~.-ALIPHATIC DIVISION. By J. C. IRVINE, D.Sc., Ph.D. . . 54Part II.-HOMOCYCLIC DIVISION. By K. J. P. ORTON, M.A., Ph.D. . 94STEWART, D Sc. . . . . . . . . . . 124ANALYTICAL CHEMISTRY. By G. CECIL JONES, F.I.C. . . . . 162PHYSIOLOGICAL CHEMISTRY.F.R.S. . . . . . . . , . . . . 190ORGANIC CHEMISTRY :-Part III.-HETP,ROCYCLIC DIVISION AND STERROCHEMISTRY.By A. w.By F. G. HOPKIW, M.A., M.B., D.Sc.,AGRICULTURAL CHEMISTRY AND VEGETARLE PHYSIOLOGY.By N. H. J. MILLER, Ph.D. . . . . . . . . 211MINERALOGICAL CHEMISTRY. By T. V. BARKER, M.A., B.Sc. . . 233RADIOACTIVITY. By FI~EDERICK SODDP, M.A., F.R.S. . . . . 26TABLE OF ABBREVIATIONS EMPLOYED I N THEREFERENCES.ABBBEVISTRD TITLE. JOURNAL.A. . . . . . Abstracts in Journal of the Chemical Society.*Amer. Chem. J . . . . American Chemical Journal.Amcr. J. Physiol . . American Journal of Physiology.Amer. J. Sci. . . . American Journal of Science.Analyst . . , . The Analyst.dnnalea . . , . Justus Liebig’s Annalen der Chemie.Ann. Bot. . . . . Annals of Botany.Ann. Chim. a.naZ. , . Annales de Chiniie analytique appliquke h l’hdustrie,Ann. Chim.Phys. . . Annales de Chimie e t de Physique.Ann. Physik . . . Anualen derPhysik.Ann. Report , . . Annual Reports of the Chemical Society.Arch.. expt. Path. Pharnt. . Archiv. fur experimentelle Pathologie unct Pharmako-Arch. Farm. sperim. , . Archivio di Farmacologia sperimentale e ScienzeArch. Pharm. . . Archiv der Phaimazie.Atti A. Aecad. iincei .Atti R. Accnd. Sci. Torino.Ber. . , . . . Berichte der Deutschen chemischen GesellschaftBer. Deut. bot. Ges. , . Berichte der Deutschen botanischen Gesellschaft.Be?. Deut. physikal. Ges. . Berichte dcr ’Deutschen physikalischen Gesellschaft.Bied. Zentr. . . . Biedermann’s Zentralblatt fur Agrikulturchemie undBicchem. Bull. . . . Biochemical Bulletin.Bio-Chem. J.. . . .The Bio-Chemical Journal.Biochem. Zeitsch. . . Biochemische Zeitschrift.Bull. Acad. roy. Belg. . Acad6rnie royale de Belgique-Bulletin de la ClasseBd1. Acad. Sci. Crncow . Bulletin international de I’Acadhie des Sciences deBUZZ. Acnd. Xci., St. Pklers- Bulletin de 1’Academie Imperiale des Sciences deBull. Assoc. chirn. Sucr. Dist. Bulletin de 1’Association des chiniistes de Sucrerie etde Distillerie.Bull. SOC. chin?,. . . Bulletin de la Socihtd chimique de France.Bull. SOC. franq. Min.Ccntr. Bnkt. Par. . . Centralblatt fur Bakteriologie, Parasitenkunde undCentr. Min. . . . Centralblatt fur Mineralogie, Geologie und Palaeonto-Chm. Ncws . . . ChemicalNews.Chem. Feekblad . . Chemisch Weekblad.Chem. Zeit. . . . Chemiker Zeitung.Chem.Zentr. . . . Chemisches Zentralblntt.CGmpt. rend. . . . Comptes rendus hebdomadaires des SQances deDeutsch. rncd. Wochcnsch. . Deli tsche niedizinische Wochenschrift.Gazzetta , . . . Gazzetta chimica italiana.h I’Agricultnre, ti la Pharmacie et h la Riologie.logie.affini.Atti della Reale Atcademia dei Lincei.Atti della Reale Accademia delle Scienze di Toriiio.rationellen Landwirtschafts- Betrieb.dos Sciences.Cracovie.bourg , . . . St. PQtersbourg.. Bulletin de la Socidtd franpaise de Mindralogie.Infektionskrankheiten.logie.l’Acad6mie des Sciences.The year is not inserted in references t o 1913viii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.Intern. Sugar J. . .Jih rb. Radioaktia. Eleklro-n i k .. . . .J. Agric. Sci. . . .J. Amer. Chem. Xoc. . .J. Biol. Chem. . . .J. Chim. Phys. . . .J. Ind. Eng. Chem. , .J. last. Metals . . .J. Landw. . . . .J. Palh. Bact. . . .J. Pharm. Chim. . .J. Physical Chem. . .J. Physiol. . . .J . p r . Chem. . . .J. Roy. Agric. Xoc. .J. ~ o y . ~ o c . Hew SoutiWales . . . .J. Buss. Phys. Chem. SOC. .J. SOC. Chem. Ind. . .J. Soc. Dyers . . .J. Washington Acad. Sci. .Koll. Chern. Beihefle . .Kolloid. Zc'iitsch. . .Landw. Jahrb. . . .Landw. Versuchs-Stat. .Aonatsh. . . . .Oestcw. Zeitsch. Berg. - IG.Pfliiyer's Archiy, . .Phil. Mag. . . .Phil. Trans. . . .Hiitbnw.Physikal. Zeitsch. . .P . . . . . .Proc. Camb. Phil. SOC. .Proc. K. Ahad. Wetcltsch.Proc. London Phys.Xoc. .Proc. Physzol. SOC. . .Proc. Roy. Sot. . . .PTOC. Xoy. SOC. QueenslandProc. Univ. Durham Phil.Quart. J. expt. Physiol. .Rec. trav. chim. . . .Amsterdam.SOC.Sitzungsber. K. Akad. FViSs.Xkand. Archiv. Physiol. .T . . . . . .Trans. Eng. C'eram,. SOC. .Trans, Paraday SOC. . .I'sch. Min. Mitt. . .Zeitsch. anal. Chm. . .Zeitsch. angew. C h . .Zeitsch. anorg. Chenb. . .Zeitsch. Chent. Ind. KO2 Zoide.Berlin.JOURXAL.International Sugar Journal.Jahrbuch der Radioak tivitat und Elektronik.Journal of Agricultural Science.Journal of the American Chemical Society.Journal of Biological Chemistry, New York.Journal de Chiniie physique.Journal of Lndnstrial and Engineering Chemistry.Jourusl of the Institute of Metals.Journal fiir Landwirtschaft.Journal of Pathology and Bacteriology.Journal de Pharmacie et de Chimie.Journal of Physical ChemiStry.Journal of Physiology.Journal fur praktische Chemie.Journal of the Royal Agricul?ural Society.Journal of the Royal Society of New South Wales.Journal of the Physical and Chemical Society ofJournal of the Society of Chemical Industry.Journal of the Society of Dyers and Colourists.Journal of the Washington Academy of Sciences.Kolloid-Chemische Beihefte.Kolloid-Zeitsc h rift.I,andwirtschaftliche Jahrbucher.Die land wirtschaftlichen Versuchs-Stationen,Monatshefte fur Chemie und verwandte Theile andererOesterreichische Zeitschrift fur Berg.- und Hutten-Arcliiv fur die gesammte Physiologie des MenschenRussia.Wissenschaften.wesen.und der Thiere.PhiIosophical Magazine (The London, Edinburgh andDublin 1.Philosophical Transactions of the Royal Society ofPhysikalische Zeitschrift.Proceedings of the Chemical Society.Proceedings of the Cambridge Philosophical Society.Koninklijke Akademie van Wetenschappen te Amster-Proceedings of the London Physical Society.Proceedings of the Physiological Society.Proceedings of the Royal Society.Proceedings of the Koyal Society of Queensland.Proceedings of the University of Durham PhilosophicalQuai terly Journal of experimental Physiology.ltweuil des travaux chiiniques des Pays-Bas et de laSitmngsberichte der Koniglich Preussischen Akademieder Wissenschaften zu Berlin.Skandinavisches Archiv.fur Physiologie.Transactions of the Chemical Society.Transactions of the English Ceramic Society.Transactions of the Faraday Society.Tschermak's Mineralogische Mitteilungen.Zeitschrift fur analytische Chemie.Zeitschrift fur angewandte Chemie.Zeitschrift fiir anorganische Chemie.Zeitschrift fur Chemie uiid Industrie der Kolloide.London.dam. Proceedings (English version).Society.BelgiqueZeitsch. physiknl. Chem.Zeitsch. physiol. Chem..Zeitsch. zuiss. Photochem.Zcitsch. Zuckerind. Bohm.. Zeitschrift fiir physikalische Chemie, Stochiometrie. ..Genussm i t t el,und Verwandtschaftslehre.Hoppe-Seyler's Zeitschrift fur physiologische Chemie.Zeitschrift fur wissenschaftliche Photographie, Photo-Zeitschrift fur Zuckerindustrie i n Bohmen.pliysik nnd Photochemie

ISSN:0365-6217    

DOI:10.1039/AR91310FP001

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.DURING the past year a very remarkable series of papers has beenpublished dealing with the production of neon and of helium bythe passage of the electric discharge through gases a t very lowpressures. Whatever may be the correct interpretation of theformation of these gases, whether they are due t o a synthetic processtaking place, or whether they were previously occluded in the wallsof the vacuum tube or in other substances submitted to bombard-ment by cathode rays, there is no doubt that their occurrence isone of extraordinary interest and importance.Collie and Patterson on the one hand, and Sir J. J. Thomsonon the other, have proved without any possible doubt that thesegases are produced by the action of the discharge. Even ifThomson’s view turns out in the end to be the correct one, thequestion still remains t o be answered as to how these gases wereoccluded in the various substances in the first place.I f thetentative suggestion he mentions proves to give the true solution,a new field is opened up involving the radioactivity of elementshitherto considered t o be rigidly stable. Sir J. J. Thomson hasalso, by means of his well-known positive ray method, discoveredalong with the neon and helium the existence of a new gas withan atomic weight of 3, and possibly another with an atomic weightof 10. The first gas, provisionally known as X,, seems to beproduced in greater quantities than either the neon or helium.These investigations certainly rank amongst the most importantcontributions t o science of recent years.Another striking paper has been published by Sir J.Dewar onthe specific heats of the e!ements between the boiling points ofnitrogen and hydrogen. He has established the fact that whenthe specific heats are measured at these low temperatures theatomic heats of the elements are a periodic function of their atomicweights, and that the curve representing the relation between thetwo has a shape very similar to Lothar Meyer’s atomic volumecurve.Speaking generally of the work done in inorganic chemistry2INORGANIC CHEMISTRY. 29during this last year, it is becoming more and more difficult to dojustice t o i t within reasonable limits of space. Much of the workpossesses very great intrinsic interest, as, for example, that ofStock and his co-workers on the hydrides of boron.The report in the main follows the lines of those in previousyears.It has been felt advisable t o hold over an account of severalbranches of work, more particularly on rare earths, for a futurereport.A t o mic T e i g h t s .I n their report the International Committee have not recom-mended any change in the list of atomic weights published in1912. They pxpress the opinion that it is disadvantageous tomake any change unless such change is thoroughly justified, sincefrequent alteration is liable t o give rise to confusion.During the year several papers have appeared describing newdeterminations of atomic weights of various elements, and of theseperhaps the following deserve mention.lieZiurn.l-An accurate determination of the density of purehelium results in the fact that the weight of one litre of this gasis 0*17856_+0*00008. This gives the atomic weight of helium as4.002.SeZenizcm .2-Two investigations have been carried out on theatomic weight of selenium.I n the first of these the atomic weighthas been arrived a t through the density of hydrogen selenide. Thisgas was prepared by the action of water on aluminium selenide;after being dried by phosphoric oxide it was liquefied and frac-tionally distilled. The weight of one litre was found to be 3.6715grams, whence the atomic weight of selenium is 79.18. I n thesecond investigation," pure selenium was oxidised t o the dioxideby means of pure nitrogen peroxide carried in a stream of pureoxygen.The selenium dioxide was reduced to selenium by meansof hydrazine hydrate. As a mean of several determinations carriedout with great care, the atomic weight was found to be 79'141.!Z'eZlicri~cni.~-Some further work on the atomic weight of thiselement has been carried out, the method adopted being thesynthesis of the tetrabromide. The atomic weight found was127.479. The results of this determination still further confirmthe homogeneity of tellurium, for the results obtained with variousfractions of tellurium were closely similar.* \\'. Heuse, Bet-. Deiit. p k y s 3 a l . Gycs., 1913, 15, 518 ; A . , ii, 774.P. Bruylauts and A. Bytebier, Ed1. Acad. my. Belq., 1912, 856 ; A . , ii, 500.J.Jaiiiiek t ~ n d J. Aleyer, ZeG.tach. ccnorq. Chcm , 1913, 83, 51 ; A., ii, 948 ; J.W. F. Dud'ey niicl 1'. C . Bowers, J. Amer. C/iem. Xoc., 1913, 35, 876 ; A . , ii, 695.hleyer, Zeitszh. E/ektrorlwrL., 1913, 19, 533 ; A., ii, 104830 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Radium.5-Reference was made in last year’s Report to Honig-schmid’s determination of the atomic weight of radium fromanalyses of radium chloride. This year a further paper hasappeared by Honigschmid, giving his results of the determinationof the ratio RaBr,/AgBr. Six analyses with nearly one gram ofradium bromide, which had been recrystallised thirty times, gavethe atomic weight of radium as 225.96, a value which agrees extra-ordinarily well with that obtained from the analysis of the chloride.Honigschmid criticises the work of Whytlaw-Gray and Ramsay,cand he corrects their values for a constant error in the reductionof the weights to vacuum.The corrected value thus obtained is226.26k0.21. He also has made determinations of the atomicweight by Whytlaw-Gray and Ramsay’s method, namely, the con-version of radium bromide into radium chloride by heating in thecurrent of hydrogen chloride. The mean of two experiments gavethe value 225.94. Altogether Honigschmid has made seventeenanalyses of radium chloride and radium bromide, and the meanatomic weight found is 225.97 & 0.012. The extreme values were225.99 and 225.93 (Ag = 107.88 ; C1=35*457 ; Br : 79.916).Some inter‘esting papers have appeared on atomic weights andtheir relationships amongst themselves and with other propertiesof the elements.Two arithmetical relationships seem to existbetween the atomic weight of elements and the molecular weightsof compounds, both of which involve the ratio r. The first ofthese can be expressed as follows7:IT 3 -,4 !awhere n is a simple integer.may be given:As an example of this relationshipIf Stas’s atomic weights are used, the value of 7~ is found t obe 3.1417. The second relationship may be expressed by:where n, nf, a, and b are simple integers.relationship may be given:As an example of thisE= 4, HCl + 27rNH, - 2~Monntsh, 1913, 34, 283 ; A . , ii, 268.6 R. Whytlaw-Gray and Sir W. Ramsay, Proc. Roy. SOC., 1912, A. 86, 270; A . ,19J2, ii, 413.P.Dampier, J. Chim. phys,, 1913, 11, 260; A., ii, i67INORGANIC CHEMISTRY. 31which gives the value of T as 3-1416. It seems very probable thatthe relations between the atomic weights involves the ratio T, andif these relations axe true, it becomes impossible to satisfy the valuesof the atomic weights by any single system. This has been veryfavourably criticised by P. A. Guye,s who points out that therelationships found by Dampier must certainly be taken intoaccount in any study of atomic weight relations.Two papers have appearea dealing with the relations betweenatoiiiic weights and the physical properties of the elements. I none9 i t is shown how the heat of ionisation and the temperature-coefficient of ionic velocities are periodic functions of the atomicweights.I n the second paper,lo similar periodic relations are foundbetween the atomic weights of the elements and their hardness,boiling points, melting points, electric conductivity, light absorp-tion, and refractive indices.Specific Heats.Measurements have been published of the sp.ecific heats of heliumand various diatomic gases a t the ordinary temperature and a t theboiling point of liquid air.ll The specific heats a t constant pressurewere made by the continuous flow method.12 The specific heat a tconstant volume was calculated from thermodynamical relationsbased on Berthelot's equation of condition. It was found generallythat the ratio of the two specific heats tends to increase considerablywith fall of temperature.The results obtained may be tabulatedas follows:Temp.Helium .............. 18"Hydrogen ............ 18"Nitrogen ............... 20"- 188- 181- 181Oxygen . 20"181Air ..................... 20"Carbon monoxide ... 18"- 181- 180CP.4.9934.9346.8605.3306.9837.1626 987.306.9657.237.0067'244Ratio.1.6601 '6731'4071.5971'4001'4681.3991.4471'4011'4501'3981.472A very remarkable paper has been published by Dewar,l3 in* J. Chinz. p h p . , 1913, 11, 267 ; A . , ii, 767.N. Dhar, Zeitsclz. E/cktrochem., 1913, 19, 911 ; A., 1914, ii, 44.W. Biltz, ibid., 613 ; A . , ii, 855.l1 K. Scheel and W. Heuse, Ann. Physik, 1913, [iv], 40, 473 ; A . , ii, 183.l2 Ibid., 1912, [iv], 37, 79 ; A., 1912, ii, 19.Proc.Roy. h'oc., 3913, A, 89, 158; A., ji, 82732 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which he gives the specific heats of the elements between the tem-perature of boiling nitrogen and boiling hydrogen. The sub-stances were cooled in boiliiig nitrogen and then dropped intoliquid hydrogen, a fall of temperature of 57.5O. The volume ofhydrogen thus evaporated was measured. The amount of hydrogenevolved from the calorimeter when a t rest was well under 10 C.C.per minute, and this was corrected for. As in each experimentthe time occupied in the evolution of the hydrogen was about fifteenseconds, this correction only amounted to about 2 C.C. Certain othercorrections were necessary, but they need not be described in detail.The accuracy of the work is well shown by the case of lead, themean value of the specific’heat of which was found to be 0.02399,the extreme values being 0.0247 and 0.0233.The mean value givesthe atomic specific heat of lead as 4.965, whilst from Nernst andLindemann’s formula it is calculated as 5.18. At least three piecesof every substance were used The results obtained rarely variedby more than 2 to 3 per cent., and frequently they were within1 per cent. Altogether fifty-three elements were experimentedwith, about two hundred separate observations being made.Dewar finds that when atomic specific heats are plotted against,tomic weights, a periodic curve is obtained which closely resemblesLothar Meyer’s atomic volume curve. It is probable that if thespecific heats were taken between the boiling points of hydrogenand helium, the atomic specific heats would be very small andnearly constant. The investigation is being continued with theview of determining the molecular specific heats of a series ofinorganic and organic compounds.Dewar states that until moreaccurate values are obtained with purer elements and with a moreimproved form of calorimeter, it is advisable to postpone anytheoretical discussion of his results.I n connexion with Dewar’s statement as to the probability ofthe atomic specific heats, if taken between the boiling points ofhydrogen and helium, being very small and nearly constant, it isinteresting to note some results of the determination of the specificheats of some metals between Oo and looo.The specific heats14were determined of copper, aluminium, iron, zinc, silver, cadmium,tin, and lead, and their values a t Oo are given by the formulaS=4.084 x A -0.95, when S is the specific heat, and A is the atomicweight. By extrapolation it is found that a t absolute zero theatomic specific heat of the above metals has a mean value of4.813.lA E. H. Griffiths and E. Griffiths, Phil. 2”rans., 1913, A, 213, 119 ; A . , ii, 75INORGANIC C HEM ISTRY. 33Atlo tropy.Yet another allotropic modification of sulphur has been dis-covered.15 If the solution of sulphur in sulphur chloride saturateda t the ordinary temperature is heated to 150° and then cooled, itdissolves a further and considerabIe quantity of sulphur.Thiscannot be explained by the formation of Sp, since S p a t the ordinarytemperature is only sparingly soluble in sulphur chloride, andseparates out quite easily on cooling a hot solution. Systematicsolubility determinations were made of sulphur in sulphur chloridewhich had previously been heated with varying quantities of sulphura t definite temperatures and cooled to 25O, Oo, or -6OO. Again,when sulphur is heated to 125O and rapidly cooled, it becomes moresoluble in sulphur chloride. These results point to a new modifi-cation of sulphur which is named S r . Further investigation showsthat when sulphur is heated to 170° and rapidly cooled, it containsjust as much S r as when it is heated to 445O and rapidly cooled.Also it is found that heated sulphur is more soluble in toluenethan unheated sulphur, and the solubility is greater the more solidsulphur that is present..All solutions containing S r are deepyellow; f o r example, a carbon disulphide solution containing 18atoms per cent. has a colour analogous to that of a concentratedaqueous solution of potassium chromate. On cooling such asolution to -SOo, the whole of the SA separates out, leaving onlyS n in solution. Attempts were made to obtain solid S r byevaporation of such solutions, but a t first only Sp was obtained.It was found, however, that if the solution were evaporated in avacuum a t a temperature of -80°, the residue left was almostentirely soluble in toluene, a very small quantity of Sp being left.It is extremely unlikely that solutions of S?r are really solutionsof Sp.Confirmatory evidence of this was found in the action oflight on the solutions. Two solutions, one containing SA and theother containing SA and S r , were exposed to a strong light; ineach case Sp was immediately precipitated, but much less wasobtained in the case of the solution containing both SX and S?rthan in the case of the solution containing only Sh. Clearly, ifSA and Sp were identical, more Sp would have been precipitated inthe case of the solution containing SA and S r .Note may also be made of the discovery of two enantiotropicmodifications of bismuth.16 The transition temperature is 7 5 O a t760 mm. pressure, and the transition of the a-modification into thel5 A.H. W. Aten, Zeitsch. physikal. Chem., 1912, 81, 257; 1913, 83, 442; A.l6 E. Coheu and A. L. T. Moesveld, Chem. Weekblnd, 1913, 10, 656 ; A . , ii, 779.REP.-VOL. X. Dii, 40, 58034 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.&modification is accompanied by a considerable increase in volume.The P-modification is shown t o be capable of metastable existencebelow the transition tempera~ture.A. Smits17 has made an interesting application of his theory ofmolecular species to the passivity of metals. He states that metalsare built up of different molecular species, each of which has adifferent reactive power. When the metal is treated with areagent that tends to dissolve it, the equilibrium between themolecular species will be disturbed, and if the equilibrium is onlyrestored very slowly the metal will become passive.Two forms of tellurium18 have been found t o exist in dynamicequilibrium with one another, the equilibrium depending on thetemperature.The densit.y varies between 6.272 and 5.949. It ispointed out that, with the exception of the atomic weight, all theconstants of tellurium are to be doubted, owing to the existence ofunknown amounts of Te, and. Te, in all specimens of tellurium.Oxidation.Reference was made in last year’s report to Rhead and Wheeler’sinvestigation on the oxidation of carbcn, in which they find thatboth carbon monoxide and carbon dioxide are simultaneouslyproduced. During this year two further papers 19 have appeared,in which a theory is put forward to account for the experimentalfacts.It is suggested that the oxidation of carbon takes placethrough the intermediate existence of a complex of carbon andoxygen. When carbon is placed in an atmosphere of oxygen, thecarbon atoms seize the oxygen atoms owing to there being aphysico-chemical attraction between she two. On heating carbonin oxygen, the molecules become fixed, that is to say, the oxygenmolecule actually enters the carbon molecule, a rearrangementtaking place. With this process heat is evolved, so that someoxygen atoms acquire enough energy t o seize hold of carbon atomsand depart with them in the form of carbon dioxide; some of theoxygen molecules become dissociated into atoms, and theref ore leavethe carbon molecules in the form of carbon monoxide.Some doubt was thrown on the experimental work leading tothis theory by EL B.Baker. He found that if absolutely dryoxygen were used, the oxidation product of carbon was almostentirely carbon monoxide, and since it is well known that carbonmonoxide and oxygen when dr;. do not readily give carbon dioxide,these results seem to point to the fact that carbon monoxide is,l7 Proc. K. Akad. Wetensch. Amsteydam, 1913, 16, 191 ; d., ii, 851.l3 E. Cohen and J. F. Kroner, Zeitsch. physikal. Chem., 1913, 82, 587 ; A., ii, 315.l9 T., 1913, 103, 461, 1210INORGANIC CHEMISTRY. 35after all, the primary oxidation product of carbon. On repeatingthese experiments, using oxygen which had been dried for fourweeks over phosphoric oxide, Rhead and Wheeler find no essentialdifference from their previous results, when the oxygen was driedonly by concentrated sulphuric acid; that is to say, they find bothcarbon monoxide and carbon dioxide in the oxidation products.I n connexion with these iesults, it is interesting to note thatboth carbon monoxide and carbon dioxide have been proved to beformed when various samples of charcoal are oxidised by dilutesolution of bleaching powder.2o The amount of carbon monoxidevaries, and in some cases as much as 9 per cent.was found.The theory advanced by Rhead and Wheeler seems to be a specialcase comprised in the general theory of chemical reaction putforward by the writer. Every chemical molecule is surrounded bya condensed force field of electromagnetic type, and if molecules ofdifferent substances are brought together they tend to form anassociated system, which in many cases has been proved to be thefirst stage in the chemical reaction between these two substances.The existence of these electromagnetic force fields explains theformation of the carbon oxygen complex as postulated above.Aslight modification of the mechanism put forward by Rhead andWheeler would seem to be advantageous. Similar cases of theformation of complexes are to be found in the absorption ofhydrogen by palladium and of oxygen by silver respectively. I nthese cases the hydrogen and the oxygen have been proved to existin the atomic condition. It is reasonable therefore t o make theassumption that in the case of carbon the oxygen also exists inthe atomic condition.The simultaneous production of carbonmonoxide and carbon dioxide from the carbon-oxygen complexwould seem to be more easily explained on these lines than onRhead and Wheeler’s explanation, according to which some of theoxygen becomes atomised during the oxidation process.The action of ozonised oxygen on certain inorganic salts hasbeen studied.21 The experiments were so devised that a givenvolume of ozonised oxygen could be divided into two parts, oneof which was used for the oxidation experiment, and the otherwas used for the determination of the ozone content. It was foundthat in the case of stannous chloride the whole molecule of ozoneis effective according to the equation:3SnClz + 6HC1+ 0, = 3SnC1, + 3H20.I n the cases of potassium arsenite, thallous and mercurous nitrates,and ferrous ammonium sulphate, only onethird of the oxygenmolecule is effective, according to the usual equation : 0, = 0, + 0.K.A. Hofmann, K. Schumpelt, and K. Ritter, Ber., 1913, 46,2854 ; A . , ii, 954.21 Y. Yaniauchi, Amer. Chem. J., 1913, 49, 55; A . , ii, 131.0 36 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n the case of the thallous salts the tliallic oxide precipitated canbe collected and weighed, and the method affords an accuratequantitative method for the estimation of ozone.An interesting investigation 22 may be mentioned here, namely,the action of nitric acid on certain metals and alloys. I n thecases of copper and silver in the presence of dilute nitric acid,approximately half the nitric acid is reduced to nitrous acid.Theexperimental results show that with silver the following expressesthe reaction :2Ag + 2HN03 = AgNO, + AgNO, + H,O.I n the case of copper the reactions are most probably as follows:~ C U + 6HN03-3C~(N0,)(N02) + 3H20,3Cu(N03)(N0,) + 2HN03 = 3Cu(N03), + H,O + 2N0.No gas is given off when dilute nitric acid is used, and the amountof reaction taking place is increased by the addition of free nitrousacid.Valency.Further work has been carried out by F. Ephraim23 on theammine derivatives of bivalent metals since that described in lastyear’s report. Certain errors have been found to be liable inthe dissociation pressure measurements of the ammines due toincomplete drying, and to the absorption of air by the finelydivided compounds.Every precaution was taken to avoid theseerrors, and the results as to the constancy of the tension-modulihave been confirmed. Calculation from the Nernst equation showsthat in the case of the hexammines of bivalent metals dissociationoccurs by the splitting off of one molecule of ammonia. This,however, is not the case with the hydrate compounds, this perhapsbeing due to the formation of solutions in the case of these com-pounds. Investigation has been extended t o the study of theammines of the sulphates of nickel, cobalt, iron, copper, manganese,zinc, cadmium,, mercury, tin, lead, calcium, strontium, and barium.The results obtained were exactly analogous to those previouslyrecorded for the halogen salts.It was again found that the value ofis constant, where T is the absolute temperature a t which theammonia pressure is equal to 500 mm., and v is the atomic volume.The mean value for the hexammines and pentammines was 13.8.It was also found that the value of:7’. 7irrJT. Jv-J. H. Stansbie, J. Soe. Chem. Ind., 1913, 32, 311 ; A . , ii, 501.Zeitsch. physiknl. Chem., 1913, 81, 513, 539 ; 83, 196 ; A . , ii, 129, 130, 496 ;Ber., 1913, 416, 3103, 3742; A , , ii, 1061 ; 1914, i, 17INORGANIC CHEMISTRY. 37was constant, being about 36.5. The ammines of cadmium sulphatewere exceptional, witK values 16.1 and 42.3 respectively. Themodulus T,/T,o, in the cases of nickel, cobalt, iron, manganesewas 1.22, and that of cadmium and zinc 1.05 to 1.13.Thehexammine derivatives of various nickel salts were compared, andi t was found generally that the stronger the acid the more stableis the ammine; certain exceptions were, however, noted. Thestability of these ammines is approximately analogous to that ofthe corresponding ammonium salts. It was found that very similarresults were obtained with the derivatives of the halogen salts ofnickel, cobalt, iron, manganese, copper, cadmium, and zinc, inwhich methylamine, ethylamine, propylamine, dimethylamine, andtriinethylamine were used in place of ammonia ; substitutedhexammines were only obtained in the case of cobalt, nickel, andmanganese, and an increasing difficulty in the preparation of thesehexammines was found with increase of molecular weight of thesubstituted aminps.I n spite of these difficulties, the conclusionsdrawn from the ammonia compounds were again confirmed, andcertain new observations made. F o r example, it was found thatthe values ot YY'. 7; were constant, and also the moduli:l B r C1 C1were constant for the same amine.Since nickel iodide shows the greatest affinity and tendency toform double compounds with ammonia and substituted ammonias,these ammines were compared and arranged in order of theirstability. It was found that this series runs parallel with the273 + T molecular volumes of the bases, and with the values of -- Pwhere T and P are the critical temperatures and pressures of thebases.These investigations have been criticised adversely,2* butEphraim has shown that these criticisms are unfounded.25Electric Discharge.A most remarkable series of papers has appeared during theyear on the production of neon and helium in vacuum tubes underthe influence of the electric discharge. 8ome time ago it had beennoticed by Collie that many minerals change colour when bom-barded by cathode rays, and that this change of colour is especiallyiioticeable in the cases of sodalite and fluorspar. When the gases2.1 W. Hiltz, ZcilscJ),. physikal. CJbem., 1913, 82, 688 ; A., ii, 404; F. Priedrichs,ibitl., 1913, 83, 242; d., ii, 497.25 Zeitsch. physiknl. Ghmn., 1913, 83, 257 ; 84, 98; A , , ii, 578, 67738 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in the vacuum tubes in which the bombardment had been carriedout were pumped out and analysed, they were found to containsmall quantities of neon.Ramsay had also found that on pumpingout and analysing the residual gases in old X-ray bulbs theycontained helium and a small quantity of 118011.26.During this year this phenomenon has been independentlyinvestigated by Collie and by Patterson, and the results werepublished jointly.27 Some calcium fluoride was prepared in thepurest possible condition, and this was submitted to bombardmentby cathode rays. The gases evolved consisted mainly of oxygen,hydrogen, and carbon monoxide. They were sparked, and thentreated with charcoal cooled by means of liquid air. A smallamount of neon was then found.A sample of glass wool wastaken, and, after being cleaned with potassium dichromate andconcentrated sulphuric acid, it wits washed and dried a t 120O. Itwas then exposed t o the bombardment, and an analysis of thegases produced showed the -presence of neon. The glass wool wasthen taken out of the tube, and about 3 to 4 C.C. of hydrogen waslet into the tube, little by little, the pressure being kept low. Thetube was heated during the passage of the discharge, and aftersome time the hydrogen was pumped out and found t o contain asmall quantity of neon. It is obvious that the neon was eitherformed inside the tube or that it leaked in. A series of blankexperiments proved conclusively that no such leak had occurred.A large amount of the glass used in the vacuum tubes waspowdered, washed with chromic acid, and heated in an exhaustedtube until it fused.The gases evolved contained no neon.Similarly, the electrocies, which were made of aJuminium, wereheated in a vacuum until they fused; a considerable quantity ofhydrogen was obtained, but no neon. The possibility still remainedthat the glass walls of the vacuum tubes might be porous to neonuntil t'he influence of cathode rays. The discharge tube thereforewas then sealed inside another tube, which was connected to asecond mercury pump. The wires carrying the current to theelectrodes of the inner tube were so insulated that no dischargetook place in the outer tube. The outer tube was filled with neonup to about half an atmosphere pressure, while hydrogen wasadmitted t o the inner tube as in the previous experiment.Afterthe discharge had passed through the inner tube for some time,the hydrogen was pumped out, and was found to contain the sameamount of neon as usual. The neon in the outer tube was thenreplaced by helium, and after the experiment was finished no26 Sir V-. Ramsay and J. N. Collie, Nature, 1912, 89, 502.27 T., 1913, 103, 264INORGANIC CHEMISTRY. 39helium was found in the inner tube, but only the usual amount ofneon. When the experiment was carried out with the outer tubecompletely exhausted, the usual amount of neon was found in theresidues pumped from the inner tube. A little oxygen was thenlet into the outer tube and pumped out again.On treatment ofthis oxygen with charcoal cooled by means of liquid air, anuncondensable residue was obtained about fifty times the volumeobtained from the inner discharge tube, and this residue consistedmainly of helium with a small quantity of neon. When oxygenwas admitted into the outer tube to a pressure of about 15 mm.with hydrogen 5s usual in the inner tube, the same amount ofneon was found in the residues in the inner tube, while the residuefrom the outer tube gave nearly pure neon with a little helium.According therefore to whether the outer tube was entirelyexhausted or contained a small quantity of oxygen, helium con-taining a little neon or neon containing a little helium was foundin the outer tube. These experiments were independently carriedout by both Collie and Patterson.Sir J. J. Thornson28 has givenan account of a long series of experiments which he has carriedout on somewhat similar lines. His method of investigation wasto submit the gases from a vacuum tube, through which varioustypes of discharge had been made t o pass, to analysis by his well-known positive ray method. H e in this way discovered theexistence of a new gas, having an atomic weight of 3, as well asone with an atomic weight of 20, which is probably neon. Hepoints out that there is no obvious connexion between the natureof the gas experimented with and the appearance of these lines.The line of the gas having the atomic weight 3 was seen whenthe vacuum tube was filed with hydrogen, nitrogen, air, helium,or mixtures of hydrogen and oxygen.The experiments were under-taken with the object of finding the circumstances which favourthe production of the gas &, and to test whether this gas wastriatomic hydrogen or a new element. He found that the con-ditions favourable to the production of X, generally give heliumand neon. I n the majority of cases when traces of helium andneon were found, X, was present in large quantities. Two vesselswere used, one in which the gases were treated with the positiverays, and another in which the various processcs were tried forgenerating &. The two vessels were connected through a stop-cock. When the generating processes were finished, some of thegas could thus be admitted into the testing vessel and examined.The most plentiful supply of X, was obtained by: (1) bombardingmetals and other substances with cathode rays; (2) discharge from28 Nc~ture, 1913, 90, ti440 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.a Wehnelt cathode through gases a t low pressure; (3) arc dischargein gases a t comparatively high pressures.The following resultswere obtained with the arc discharge in hydrogen a t 3 cm. pressure,using iron electrodes. After the arc had been passed for about anhour, X,, helium, and neon were found. The experiments wererepeated next day, and gave the same results; on the third day,the same electrodes still being used, the arc was passed throughoxygen. The X, line was much fainter, and the presence of heliumand neon very doubtful.The experiment was again repeated onthe fourth day, and this time none of the lines were seen. Thisseems as if the production of these gases was due t o hydrogen,but the replacement of the oxygen by hydrogen, still using thesame electrodes, gave no result. On using new electrodes, the threesubstances were again obtained. This clearly points t o the factthat the electrodes were the source of these gases. Exactly similarresults were obtained when certain substances were bombardedby cathode rays. When a substance was bombarded by cathoderays, considerable quantities of X,, helium, and neon were obtaineda t first; the amount steadily decreased until no more was produced.An old sample of lead was found t o give off considerable quantitiesof these gases.Chemically pure lead was found t o give off muchless, while freshly precipitated lead gave none. The addition ofhydrogen and oxygen does not seem to increase the amount ofgases produced, and the experiments seem t o prove conclusivelythat the gases are always obtained from the substances bombarded.It is surprisingly difficult to get rid of these gases from a givensubstance by ordinary methods. For example, a sample of leadwas kept boiling in a vacuum for about three t o four hours; notrace of helium or X, was evolved; the lead, however, on beingbombarded by cathode rays, was found to give off both heliumand X,.Collie and Patter~on,~g on the other hand, find that electrodesare not necessary for the production of neon, for if a powerfuloscillating discharge is passed through a coil of wire wound rounda bulb containng a little hydrogen, helium and neon are to befound in the hydrogen.They pointed out that all mercury vapourmust be removed from the hydrogen. When a heavy discharge ispassed through a vacuum tube, very considerable quantities ofhydrogen can be made t o disappear. A gas is produced whichgives a carbon spectrum. This gas disappears when sparked withmercury vapour, and it is not easily condensed by liquid air, noris i t oxidised by sparking with oxygen. Possibly this gas is thesame as X,, described by Sir J. J. Thomson. Collie and Patterson’sP., 1913, 29, 217INORGANIC CHEMISTRY. 41results have been independently confirmed by J. I. 0. Mass~n.~*He finds that after some time neon ceases to be formed in thedischarge tube, but if a mixture of oxygen and hydrogen be added,neon again begins to form.The question arises a t once as regardsthe origin of the helium and neon in these experiments. WhereasCollie and Patterson and also Ramsay incline t o the view that theyare the production of a synthetic process, Sir J. J. Thomson holdsthe view that they are actually contained in the glass or the metals,and that they are evolved under the influence of the discharge.The difficulty in connexion with the latter view is the questionas to how the gases find their way into these substances in thefirst place. For example, Thomson poinlx out that X3 does notoccur to any appreciable extent in the atmosphere.He says thathe has sometimes ventured into the speculation whether they donot represent the partly abortive attempts of ordinary metals t oimitate the behaviour of radioactive substances ; whereas in thesesubstances the a-particles and the like are emitted with suchvelocity that they get clear away from the atom, in ordinary metalsthey have not sufficient energy to get clear, but cling to the outerparts of the atom, and have to be helped by the cathode rays toescape. If this view of Sir J. J. Thomson’s is correct, the questionarises as to the other products of radioactive degradation of themetals. Possibly, of course, these products may be non-volatile,and consequently may not be capable of detection by the methodsof experiments used by these investigators.Some years ago the writer put forward the view that the variouswell-known phenomena observed in the electric spark betweenmetallic electrodes such as the enhanced lines may be due to anassisted radioactive degradation of the metals.If the X, andhelium can be a-particles arising from these radioactive changes,then the enhanced lines may be due to other products of thechange. It would be very interesting to know whether any experi-mental inetliods would reveal the presence of the enhanced linespectrum of lead, for example, or platinum, in these dischargetubes.c o I20 ids.Reference was made in last year’s report to the preparation ofcertain of the organo~ols.~~ Similar organosols of palladium andplatinum have now been prepared.3s The method of preparation isbriefly as follows: lanolin is impregnated with an aqueous solutionP., 1913, 29, 233.31 An*&.lieport, 1912, 54.m 0. Amberger, Kolloid. Zeitsch., 1913, 13, 310, 313 ; A . , 1914, ii, 6042 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of either platinous or palladous chloride; it is then triturated withalkali carbonate, and finally treated with a solution of hydrazinehydrate. The lanolin acts as a protective colloid, and theorganosols so obtained are soluble in chloroform, carbon tetra-chloride, ether, light petroleum, etc. The preparation made in thisway contained as much as 16 per cent. of palladium and 18 percent. of platinum. I n an exactly similar way an organosol ofplatinous hydroxide wa8 prepared containing as much as 31.1 percent.of Pt(OH),.It ha,s been found that if the fusions obtained by the action ofmagnesium, potassium, or sodium on boron trioxide axe extractedfirst with hydrochloric acid and then several times with water, anaqueous filtrate is obtained, which possesses a decided colour, andcontains a colloidal boron in solution.% These solutions ar0 veryreadily oxidised and very readily coagulated ; they contain about0.06 per cent. of boron. The colour of the solution varies accordingto the metal used in the reduction of the boron trioxide. I fmagnesium or potassiuni is used, the solution has a reddish-browncolour, but when sodium is used the solution is blue.A simple method has been published of obtaining colloidal silversolutions.31 When dry pyridine solutions of silver nitrate andpyrogallol are mixed, a pale yellow solution is obtained, which ontreatment with water gives solutions of colloidal silver.The colourof these solutions varies from yellow to orange, and finally violet,by transmitted light. When the solution contains 0.05 per cent.of silver it is fairly stable, and the colloid may be separated bycentrifugalisation. Analogous results were also obtained withcupric sulphate.The preparation has also been described of colloidal solutions ofsilver and mercuric sulphides by mixing dry pyridine solutions ofhydrogen sulphide and silver nitrate or mercuric acetate.Group I .Some experiments on Schutzenberger’s allotropic copper 35 haveled to the conclusion that it is colloidal, and its production hasbeen explained by the protective colloid theory.36 Cupric acetate ispartly hydrolysed in solution with the formation of a basic saltor the hydroxide which remains in suspension.This wanders tothe cathode during the electrolysis, and acts as a protective colloid33 A. Gutbier, Kolloid. Zeitsch., 1913, 13, 137 ; A., ii, 860.34 A. Pieroni, Gnmctfn, 1913, 43, i, 197 ; A., ii, 393.36 Conzpt. rend. 1878, 86, 600 ; A , , 1878, 548.36 T. R. Briggs, J. Physical Chem., 1913, 17, 281 ; A., ii, 606INORGANIC CHEMISTRY. 43to the copper there deposited. The metal, therefore, is precipitatedin the form of a solid gel.The alkali metals have been prepared in an absolutely pure stateby heating the anhydrous chlorides with metallic calcium.37 Anexhaustive study has been made of the properties of these metals,of which the following may be quoted:Na.K. Rb . cs.Dcnsity at 0" ............... 0.9723 0.859 1-52,? 1-903Critical temperature ...... 2025" 1965" 1857" 1627"The increase of electropositivity with rise in atomic weight iswell shown by the following figures, which reprwent the lowesttemperatures a t which any action with water can be detected :Na, -98"; K, - 1 0 5 O ; Rb, - 1 0 8 O ; Cs, - 1 1 6 O .The electrical properties of these elements are dealt with in asecond paper.%The preparation of ammonium hydroperoxide has already beendescribed.39 It has now been found possible by the same method toprepare ammonium per~xide.~O Dry ammonia is led into an absoluteethereal solution of hydrogen peroxide (98 per cent.) a t - loo; ina short time crystals are obtained of the ammonium hydroperoxide,NH40,H[(NH,),0, + H,O,].These crystals melt a t 1 4 O . I f theaction of ammonia is continued, a heavy, oily layer separates, andthis oil can be frozen a t -4OO. The crystals thus obtained can bewashed with ether a t -400, and are found to be ammoniumperoxide, (NH,),O,. The compound begins to lose ammonia a t-loo, and melts a t - 2 O ; it readily loses ammonia, and afterremaining all night a t + 2 O it gives pure crystals of the hydro-peroxide.The preparation of pure anhydrous sodium and potassium hydro-sulphides by the action of hydrogen sulphide on the ethoxides ofthese metals dissolved in absolute alcohol, and subsequent precipi-tation by the addition of benzene or ether, was described two yearsag0.41 The work has been followed up by a study of the prepara-tion of pure anhydrous sodium monosulphide.42 The reactionbetween sodium ethoxide and sodium hydrosulphide is found to bereversible, and.although sodium monosulphide can be preparedby the mutual action of these substances in alcoholic solution, usingan excess of sodium ethoxide, yet this method is not satisfactory,37 L. Hackspill, A m . Chint Phys., 1913, [viii], 28, 613 ; A., ii, 503.a8 I,. Hackspill and W. Hroniewski, ibid., 1918, [viii], 29, 455.39 P. G. Melikov and 11. Pissayjevski, Rer., 1897, 30, 3114 ; 189S, 31, 152, 4-16 ;40 J. D'Aus and 0. Wedig, ibid., 1913, 46, 3075 ; A., ii, 1051.dl A.Rule, T,, 1911, 99, 558.43 J. S. Thomas and A. Rule, ibid., 1913, 103, 871.A . , 1898, ii, 161, 219, 29244 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.owing to the difficulty of removing the sodium ethoxide from thesalt. By heating sodium hydrosulphide with gradual rise oftemperature and continuous removal of the hydrogen sulphide ithas been found possible to obtain a quantitative yield of sodiumsulphide, Na,S. This method was found necessary owing to thefact of the dissociation of the hydrogen sulphide with the resultingformation of varying amounts of polysulphides. The Na,S obtainedis therefore coloured strongly yellow. When prepared by themethod described the Na2S is a faintly buff powder, and onlycontains very small traces of polysulphide sulphur.Group 11.Metallic glucinum has been obtained by the electrolysis of afusion consisting of sodium fluoride (one mol.) and glucinum fluoride(two mols.).43 A nickel crucible is used as cathode and a carbonrod as anode.The current used was from 7 to 10 amperes a t 15volts. The crystals of glucinum thus obtained had a density of1.842. They cannot be melted in air to form a compact mass owingto surface oxidation. If, however, the crystals are compressed andheated in an electric vacuum furnace a compact mass is obtained.The metal melts at 128Oo&2O0, and is not very easily attacked byalkalis.Metallic bariuni44 may very readily be obtained in a pure stateby heating a mixture of silicon and barium oxide in an exhaustedsteel tube, when the following reaction takes place:3Ba0 + Si = BaSi03 + 2Ba.The barium distils away, and is deposited in the cooler portionsof the tube.Bythe reaction between glucinum hydroxide and phosphoric acid,monoglucinum orthophosphate, GlH4(P04),, was obtained as colour-less, very hygroscopic leaflets ; triglucinum orthophosphate,G1,P20,,6H,0, was obtained as a loose precipitate by the actionof disodium phosphate on glucinum salts in the presence of aceticacid. I n the presence of sodium hydroxide, a basic orthophosphateis precipitated having a constitution 2G13P,08,G10,1 3H,O.By pre-cipitation of glucinum salts with sodium pyrophosphate, glucinumpyrophosphate, G1,P,0,,9H20, was obtained as a white, amorphousprecipitate.The following metaphosphates were also prepared :Gl(PO,), and 2Gl(PO,),GlO. Glucinum phosphite,4G1HP03,G10,7H,0,and glucinum hypophosphite, G1H4P204, have also been obtained.9 series of phosphates of glucinum has been described.45a F. Fichter and K. Jablczynski, Bcr., 1913, 46, 1604 ; A . , ii, 594.C. Matignon, Conzpt. rend., 1913, 156, 1378 ; A., ii, 504.45 B. Bleyer :jnd B. Miiller, Zcitsch. nnorg. Chsnt., 1912, 79, 263 ; A . , ii, 137INORGANIC CHEMISTRY. 45C?-oztp 112.Some further work has been carried out on the hydrides ofboron.46 I n last year's report two hydrides of boron were described,namely, B,H,, and B,HJ,. When the former compound is kept a tthe ordinary temperature it slowly undergoes decomposition, andthe only gaseous products are hydrogen and a third boron hydridehaving the formula B2H,.This reaction is catalysed by ultra-violet light, and a t 100') the decomposition is completed in a fewhours. The compound B2H, is a colourless gas, which boils a t- 8 7 O t o - 8 8 O ; it is more stable than B4H10, and reacts withwater according to the following equation :This afforded a method of analysis of the compound, and it wasalso analysed by explosion with excess of air. The density of thecompound was found to be 27.8, the theoretical value for B,H,being 28. It may be pointed out that the formula B,H, shows theexistence of boron in a quadrivalent condition. The compound isstable when pure and stored over mercury a t the ordinary tem-perature, but in the presence of air it tends to give compoundscontaining oxygen. On heating, B,H, decomposes to give hydrogenand a series of solid hydrides of boron.47 If a horizontal tubefilled with B2H, is heated along one-half of its length t o a tem-perature of 1 1 5 O to 120° during forty-eight hours, the other halfof the tube being kept cooled, long needles are deposited, whichon analysis are found to have the constitution BI"H14.Altogether,three solid boron hydrides are formed by the decomposition of B2Hs,one of which is volatile in a vacuum, namely, B,,H14; the othertwo are not volatile, and one of these is colourless and soluble incarbon disulphide, and the other is yellow and insoluble in carbondisulphide. The compound Bl,Hl, is soluble in alcohol, ether, orbenzene, and is not acted on by water.It melts a t 99.5O; a t 600°to 700° it decomposes into boron and hydrogen. Its molecularweight was determined by the freezing point of its solutions inbenzene. The two other hydrides of boron have not yet beencompletely investigated, but it would seem that the yellow com-pound contains five atoms of boron t o four atoms of hydrogen,whilst the colourless compound has twelve atoms of boron in themolecule. Certain other compounds of boron and hydrogen stillremain to be investigated.Some doubt has been thrown on the existence of aluminates asdefinite compounds,48 the suggestion being made that the solubilityB2HG + GH2O = 2H3B0, + 6H2.46 A. Stock and K. Friederici, Ber., 1913, 46, 1959 ; A., ii, 699.'7 A.Stock, K. Friederici and 0. Priess, ibid., 3353 ; A . , ii, 1053.E. G. Mahin, D. C. Ingraham and 0. J. Stewart, J. Amer. Chern. Soc., 1913,35, 30 ; A., ii, 13946 ANNUAT, REPORTS ON THE PROGRESS OF CHEMISTRY.of aluiiiiniuiii Iiydroside in alkali is largeIy due to its colloidalproperties. In a more recent paper this conclusion has been dis-pr~ved.~’JA series of electromotive force measurements with solutions ofaluminium chloride during the precipitation and redissolving ofthe’ aluminium hydroxide on the addition of alkali has provedthat a reaction takes place between exactly one molecule of Al(OH),arid one molecule of NaOH or KOH; in other words, aluniinatesmust exist with the formula KAlO, or NaAlO,.Group ZV.The heats of combustion of diamond and graphite have beendetermined and found to be 7896 & 3 and 7854 & 1 calories per gramrespectively.50 The latter seems generally to be independent ofthe salts of the graphite.Purified graphite from cast iron fromthe blast furnace gave a value of 7855 to 7865 calories, which isvery near the value given above.Some work has been carried out on the production and propertiesof red 1ead.51 Red lead is shown to exist in two forms, onecrystalline and the other amorphous, and its specific gravity variesfrom 8.32 to 9’-16. The optimum temperature for production ofred lead varies with the starting material used. About 425O to430° is best for white lead, 450° t o 470° for litharge and leadsponge, and about 45OC for converting lead hydroxide and metalliclead into red lead.It would seem that 450° is most probably thetemperature a t which red lead can be most economically producedfrom any suitable starting material. At 525O to 530° red leadis rapidly reduced to litharge. Both yellow and red litharge aremore slowly roasted to red lead when they have been treated withwater.The conversion of litharge into red lead in an atmosphere ofoxygen has been studied a t temperatures between 325O and 520°,and under pressures varying from 1 to 12 atmospheres.52 It wasfound that the equilibrium is independent of the pressure, althoughit is sooner arrived a t with increasing pressure. A t a temperatureof from 470° to 480° a quantitative yield of red lead wit^ obtainedin three hours; above and below this temperature the yield issmaller.I n view of the theory of the production of petroleum deposits,49 W.Blnm, J. Amer. Chcnz. SOC., 1913, 35, 1499 ; A , , ii, 963.51 0. W. Brown and A. B. Nees, J. Ind. Eng. Chem., 1912, 4, 867 ; A., ii, 410.5J J. Milbauer, Chcm. Zeit., 1912, 36, 1436, 1484; A,, ii, 138.IT. A. Roth and H. Wallasch. Ber., 1913, 46, 896 ; A., ii, 384INORGANIC CHEMISTR’I‘. 47some interesting analyses have been published of the gases evolvedby the action of water on the carbides of uranium, thorium,53 andthe metals of the cerium group.54 The carbides of uranium andthorium give mixtures of hydrogen, methane, ethane, propane,butane, ethylene, propylene, and homologues, together with someacetylenic hydrocarbons.I n the case of the cerium metal carbides,no methane is produced, but there are found acetylene, allylene,and the higher homologues, together with small quantities ofethylene, ethane, and homologues ; some free hydrogen is present,and therefore it is possible that the ethylene and ethane hydro-carbons are formed by the hydrogenation of acetylene and itshomologues. The metal is always converted into the hydratedsesquioxide.Group V .Some doubt has been thrown on the method of formation ofStrutt’s active nitrogen.55 The view has been put forward that itsformation is due to the presence of small quantities of oxygen. Onthe other hand, Strutt56 more recently has published results whichprove that the presence of oxygen is not necessary, since 2 percent.of oxygen entirely stops its formation. This has also beenindependently confirmed.57Some chemical reactions of active nitrogen have been studied.58If ‘the active nitrogen is passed into the vapours of mercury,cadmium, zinc, arsenic, sodium, and sulphur, the nitrides of theseelements are formed, and they give ammonia when treated withwater or with alkali. Sulphur chloride, when treated with activenitrogen, gives the ordinary yellow nitrogen sulphide. Acetylene,benzene, pentane, methyl bromide, ethyl iodide, ethyl chloride, andether, when treated with active nitrogen, all give hydrogen cyanide.Some further study 59 has been made of the alkali metal phos-phides, M2P,, mentioned in last year’s report.60 These compoundswhen treated with very dilute acetic acid give a yellow solid, whichis found to be H2P,.The solid hydrogen phosphideel previously53 P. Lebeau and A. Damiens, Compt. rend., 1913, 156, 1937; A., ii, 700.54 A. Damiens, ibid., 1913, 157, 214 ; A . , ii, 777.5s F. Comte, Physikal. Zeitsch., 1913, 14, 74 ; A., ii, 210 ; E. Tirde, Ber., 1913,58 Physikal. Zeitsch., 1913, 14, 215; A., ii, 316.s7 A. Koenig and E. Elod, ibid., 165 ; A . , ii, 316.58 R. J. Strutt, Proc. Roy. SOC., 1913, A, 88, 539 ; A., ii, 696.5B L. Hackspill, Compt. rend., 1913,156, 1466 ; A., ii, 584.68 Ann. Report, 1912, 60.46, 340 ; A., ii, 210.&-Stock, W. Bottcher #and W. Lenger, Ber., 1909, 42, 2839 ; A,, 1909, ii,72748 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.described, on being lieateti in a vacuum to 80°, gives gaseoushydrogen phosphide, and leaves a residue of H2P,.This substaiicehad acid properties, and the phosphides, K2P5, Rb,P,, etc., maybe prepared from it.Two years ago it was shown that hydrazine sulphate is decom-posed by liquid ammonia 62 according to the following equation :Since ammonium sulphate is insoluble in liquid ammonia, i t ispointed out that this might give a practical method for thepreparation of hydrazine. The reaction has now been furtherstudied,63 and it is proved to be quantitative, a 90 to 95 per cent.yield of hydrazine being obtained. The process is carried out inan apparatus especially designed for the extraction of substancesby liquefied gases.I n the experiments described, the apparatus ismade of glass, but it might easily be constructed of iron, and thenwould be suitable for the preparation of hydrazine on a commercialscale.Hydrazine nitrite may be prepared by mixing solutions ofbarium nitrite and neutral hydrazine sulphate.64 The filtrate fromthe barium sulphate is evaporated in a vacuum over phosphoricoxide. The white residue may be crystallised from a mixture ofalcohol and ether. It forms hygroscopic crystals, and explodesviolently on being struck and less violently on heating. It decom-poses according to the equation : N2H,HN0, = NH, + N,O + H,O.As this reaction is accelerated by free nitrous acid, i t is obviousthat hydrazine dinitrite cannot be obtained.Some interesting work has been carried out on some of theoxides of nitrogen.I n the case of the t8etroxide,65 the vapour-pressures were determined between the temperatures of - 40.5O and- 1 1 O . The calculations of the vapour-pressures were made fromSchreber's f ormula,66 and, as these calculated values were smallerthan those actually obtained, it is clear that some of the N204 inthe gaseous phase is dissociated into NO, even a t these low tem-peratures. The amount of the dissociation increases from 0.06 at- 40'5O to 0.084 a t - 10'8O.It would seem that in the case of nitrogen pentoxide67 noneof the data concerning its physical constants hitherto published iscorrect, since it appears never to have been prepared in a pure62 A. W. Browne nud T. W. B.Welsh, J. Amer. C h m . Soc., 1911, 33, 1728;6J F. Friedrichs, itid., 1913, 35, 244 ; A., ii, 316.64 F. Sommer, Zeikch. anorg. Chem., 1913, 83, 119; A., ii, 952.c5 F. RUSS, Zeitsch. physikal. Chcm., 1913, 82, 217; A., ii, 186.66 Zeitsch. physikal. Cheni., 1897, 24, 651 ; A., 1898, ii, 153.67 F. Rues and E. Pokoruy, Monatsh., 1913, M, 1027, 1051.N2H,,H,SO, + 2NH,= (NHJ2SO4 + N2H4.A., 1911, ii, 1084INORGANIC CHEMISTRY. 49state. An account has been given of its preparation by the well-known method of the fractional distillation of a mixture of con-centrated nitric acid and phosphoric oxide. The vapours ofnitrogen pentoxide thus obtained are, however, far from pure.The distillation is carried out in a stream of ozonised oxygen, andthe mixed gases passed through a tube containing more phosphoricoxide.I n this way complete dehydration of the nitrogen pentoxideis obtained, and all tendency for it to dissociate into lower oxidesof nitrogen is prevented by the ozone. The nitrogen pentoxide isthus obtained in an absolutely pure state,. and may be completelycondensed a t - 80°. The vapour-pressures of this substance havebeen determined between the temperatures of - 80° and + 17'5O.It is found that above Oo the vapour is partly dissociated. Inasmuchas the pressure reaches one atmosphere before the substance melts,i t may be pointed out that nitrogen pentoxide has no true meltingpoint or boiling point.A further investigation has been made on the so-called nitrogenhexoxide, NO,, which is produced when nitric oxide is passed intoliquid oxygen.** This substance, when suspended in liquid oxygen,is coloured green, and as the oxygen boils away the fine flocksunite to a compact powder, which has a dull greyish-blue colour.It appears that this change of colour is accompanied by a chemicaldecomposition, and that a loss of oxygen occurs.The dull bluecompound has been obtained free from oxygen by repeated washingwith liquid nitrogen. It is found that during the washing a certainamount of oxygen is given off, and that the resulting dull bluepowder has a formula NO, or N,O,. It is obvious that the sub-stance is not the same as the ordinary nitrogen tetroxide, becausethe latter substance exists as wkiite crystals a t low temperatures.It is concluded from these experiments that the green substancewhich is produced when nitric oxide is passed into liquid oxygenis the nitrogen hexoxide, NO,, and that on washing with liquidnitrogen i t loses a portion of its oxygen, and is converted into anisomeride of nitrogen tetroxide.This substance is named nitrogenisotetroxide.An exhaustive study has been made of the physical constants ofnitrosyl ~hloride.~g The nitrosyl chloride was prepared by threedifferent methods ; a mixture of chamber crystals and potassiumchloride, previously dried in a vacuum over phosphoric oxide, washeated to about 80°. I n the second method pure chlorine andnitric oxide, after drying by means of sulphuric acid, were allowedto mix and to pass over animal charcoal a t about 50°.It wasF. Raschig, Zeitsch. anorg. Chem., 1913, 84, 115; A., 1914, ii, 49.69 E. Briner and Mlle. 2. Pylkov, J. Chim. phys., 1912, 10, 640 ; A . , ii, 317.REP.-VOL X. 50 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.found, however, that the animal charcoal was not necessary for theunion between the two gases, as just as good a yield of nitrosylchloride was obtained by simply mixing the gases a t the ordinarytemperature. The third method of preparation was based on thereaction between hydrogen chloride and nitrogen trioxide. Thestream of hydrogen chloride was led into the nitrogen trioxide ina vessel cooled by a freezing mixture. The following reaction takesplace : N203 + 2HC1= 2NOC1+ H20 ; when the reaction was carriedout in the presence of phosphoric oxide, nitrosyl chloride wasobtained free from water.I n each case it was found necessaryto purify the substance, and this was done by a series of fractionaldistillations and recrystallisatioas. It was found that the densityof the compound varies from 1.550 at - 5 5 O to 1.221 at + 4 9 O . Thevalues of the surface tension, according to Ramsay and Shields’method,70 show evidence of a slight amount of association, butfrom the formulae of Kistiakowski77l o r Dutoit and Mojoiu,72 orWaldeii,73 it appears that nitrosyl chloride is unimolecular in theliquid state. The vapour pressure rises from 13 cm. a t -60° to142 cm. a t +loo. The boiling point a t 760 mm. was found to be-5.5O. A series of thermochemical data are given of the forma-tion of nitrosyl chloride from its elements, and other reactions.Group VI.Some attention has been paid to the action of sulphur trioxide onvarious compounds.For example, when molten sulphur trioxideand silicon tetrachloride are mixed. a slow reaction sets in; a t atemperature of 50° the reaction is complete in from six to tenhours.74.2SiC1, + 250, = Si20C1, + S20,C1, ;with a large excess of sulphur trioxide a second reaction takesplace : Si,OCl; + 6S0, = 2Si0, + 3s,O5c1,. Silicophosgen is notformed.The action of sulphur trioxide on certain salts of sodium,potassium, and ammonium has also been studied.75 A weighedquantity of the salt was placed in a specially devised desiccatorwhich contained sulphuric acid, and the apparatus was thenIt takes place accord:ng to the following equation :70 T., 1893, 63, 1089.7l Zeitsch.Elektrochem., 1906, 12, 513; A., 1906, ii, 655.72 J. Chim. phys., 1909, 7, 160 ; A . , 1909, ii, 479.7y Zeitsch. Heklrochem., 1908 14, 713 ; A . , 1908, ii, 1014.7* C. R. Sangor and E. R. Riegel, Zeitsch. anorg. Chem., 1913, 80, 262 ; A., ii,75 W. Traube, Ber., 1918, 46, 2513, 2525 ; A , , ii, 947.405INORGANIC CHEMISTRY. 51exhausted. In this way all traces of moisture were removed fromtlie salt and from tlie walls of tlie apparatus. The sulphuric acidwas then removed and replaced by fuming sulphuric acid, and theapparatus once more exhausted. The various salts were left forseveral days exposed to the sulphur trioxide vapour.All thesulphur trioxide was carefully removed from the apparatus beforethe compounds were brought into the air. The increase in weightof the salts was determined, and they were also analysed. I n thecase of the chlorides two molecules of sulphur trioxide were absorbedby one molecule of the salt with the production of the chloropyro-sulphonate, foi example, ONa*S02*O*S02C1. I n the case of sodiumnitrite one molecule takes up three molecules of sulphur trioxide togive the nitrosotrisulphon+te, NOe(S03),Na, a salt that reactsviolently with water with evolution of oxides of nitrogen.Sodium and potassium persulphates give perpyrosulpliatesaccording t o the equation K,S,08 + 2S0, = KS,O,*O,-S,O,K. Theseperpyrosulphates deliquesce in air without the evolution of oxygen,and the solution thus obtained contains hydrogen peroxide andpersulphuric acid in varying proportions.When placed direct intowater they dissolve with violent hissing, and give off ozonisedoxygen. The solution then only contains traces of hydrogenperoxide and persulphuric acid.I n the case of the fluorides only one molecule of sulphur trioxideis absorbed with the formation of the fluorosulphonate, for example,FS03Na, which can readily be dissolved from the insolublefluorides by extraction with alcohol. Ammonium fluorosulphonateis easily prepared as a stable salt, and can be recrystallised fromhot water in the form *of needles, which melt a t 245O. The fluoro-sulphonates are obtained also by heating together the dry fluorideand pyrosulphate.If ammonium fluoride is heated with fumingsulphuric acid, fluorosulphonic acid distils over in good yield.The fluorosulphonates are neutral to litmus. When the sodiumsalt is heated in an atmosphere of carbon dioxide, a gas is evolvedwhich is probably sulphuryl fluoride, produced according to theequation : 2FS03Na = Na,SO, + S02F2.Some double compounds of hydrazine and chromous salts havebeen described.76 Chromous acetate is suspended in air-free water,which is then covered with a layer of light petroleum; exactly thenecessary quantity of acid is added t o dissolve the salt, and asolution of hydrazine hydrate or hydrazine sulphate is then added,when the double salts are precipitated. For example, CrC122N,H,and CrBr22N2H4 were prepared, in the form of lilac powders. Thesalts generally are fairly stable.76 W. Traube and W. Passarge, Ber., 1913, 40, 1605 ; A . , ii, 604.E 52 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.An exhaustive study has been made of the metallic tell~rites.~7I n the case of the alkali metals, mono-, di-, and tetra-tellurites havebeen prepared. The first two are obtained by fusing telluriumdioxide with the calculated quantity of alkali carbonate, the lastby the action of water on the ditellurites. I n the case of othermetals, the tellurites are prepared by the action of sodium telluriteon a soluble salt, usually the chloride. The alkali metal salts aresoluble in water, those of the alkaline earth metals are sparinglysoluble, whilst the salts of the heavy metals are insoluble. Theyare all somewhat unstable, being decomposed by carbon dioxide,and when heated in air t o 440° t o 470° they are oxidised. Thefollowing compounds were studied : K,Te03,3H,0 ; K2Te20, ;K,Te40,,4&0 ; NazTe03,5Hz0 ; Na2Te20, ; Na2Te409,4H20 ;5MgTe03,9H20 ; 3CdTe03,2H,0 ; Ag2Te0,; NiTe0,,2H20 ;CoTe03,H20 ; and 3PbTe03,2H20.Grozrp ?71Z.If a freshly prepared solution of sodium or potassium hypo-bromite is heated a t 80° for a few minutes and then cooled andtreated with an excess of ammonium chloride, it still retainsoxidising power towards alkali arsenite.78 The amount of oxidisingpower is about one-tenth of that of the original solution. Itwas analytically proved that the solution contains sodium orpotassium bromite. It was also found that in the spontaneouschange of hypochlorite or hypobromite solution into clilorate orbromate the chlorite or bromite exists as a definite intermediatephase. These salts were found to exist in solutions of hypo-chlorites and hypobromites which had been kept for a considerablelength of time. The view has been put forward that the firststage in the reaction is the formation of the chlorite or bromite,and that this is then oxidised by a further quantity of hypochloriteor hypobromite to the chlorate or bromate.Group VZII.By the action of fluorine on metallic osmium heated in aplatinum tube, OsF,, OsF,, and OsF, have been prepared.79 Theoctafluoride can readily be separated from the others by exhaustingthe tube, and condensing the compound in a vessel cooled by liquidair. The osmium was77 V. Lenher and E. Wolesensky, J. Amer. CJwn. Soc., 1913, 35, 718 ; A., ii, 582.7* J. Clarens, Compl. rend., 1913, 156, 1998 ; 157, 216; A., ii, 693, 772.79 0. Ruff and F. W. Tschirch, Ber., 1913, 46, 929 ; A . , ii, 416.It forms yellow crystals, melting a t 34'5O1 NORGANIC CHEMISTRY. 53prepared from the dioxide by very careful reduction in an atmo-sphere of hydrogen and carbon dioxide. From one gram of metalabout 0.6 gram of OsF, was prepared. A series of vapour densitymeasuiements showed conclusively that i t has a formula OsF,,and in this way the octavalence of osmium is clearly established.E. C. C. BALY

ISSN:0365-6217    

DOI:10.1039/AR9131000028

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART I.-ALIPHATIC DIVISION.'I'm subdivision into three parts of the section of the AnnualReports dealing with Organic Chemistry has naturally simplifiedthe work of the reviewers considerably, but has restricted theopportunities t o make a general survey of the developments inthis branch of the subject. It would be unfortunate if the changeof policy, desirable in itself, had the effect of banishing from thepages of the Reports those critical reviews, embracing the wholefield of organic research, which have in the past been conspicuousand useful features of this section. I n the meantime, however,there is libtle necessity t o make provision for a general introduction,as the accounts given in preqious volumes of the tendencies andprinciples which appear t o be operative in organic research canbe applied equally well to the position of Organic Chemistry a tthe present time.A survey of the investigations in the aliphatic series publishedduring the past eighteen months fails to find any one particulardiscovery which can be ranked as of outstanding importance, oras likely to produce revolutionary changes in our ideas.Dramaticdiscoveries are fortunately rare in organic chemistry, and even themost important observations may pass unnoticed, through lack ofthe necessary perspective, when records of research are compiledannually. It is nevertheless evident that original work in thealiphatic series continues t o be of a high quality, although, inmany ways, i t is more restricted in scope than was formerly thecase.I n several classes of compounds little or no progress hasbeen made, and research shows a distinct tendency to concentrateon a comparatively limited number of specific problems. To acertain extent, particularly in the remarkable developments whichhave recently been noticeable in the chemistry of hydrocarbonsand reactions involving catalysis, this result is largely due to thepressure of technical influences, but a t the same time the effect ofother controlling forces is apparent. The renewed interest inbiological problems has undoubtedly stimulated research in the5ORGANIC CHEMISTRY. 55aliphatic series, and the rapid progress now being made in syn-thetical reactions promoted by enzymes may be quoted as a con-spicuous but by no means unique example of this, but it is equallyevident that the application of physical methods to the con-stitutional problems of organic chemistry is the most significantfeature of recent research.Papers of a purely descriptive natureare now less frequently encountered, and, as a necessary result,much of the work now being done has a definite object in viewand is strictly continuous. There is still, however, a regrettabletendency in some quarters to publish results in small and apparentlyunconnected fragments, or to describe isolated syntheses withoutgiving any idea of the ultimate object of the research.With regard to the arrangement of the present Report, i t needhardly be said that no attempt has been made to cover the wholeground, nor has the writer restricted himself to publications whichhave only appeared during the past year.' A s far as possible,attention has been directed to work which has resulted in definiteconclusions, but occasionally topics which are incompletely developedare discussed when the present position of the subject shows featuresof special interest. Owing to the fact that recent PresidentialAddresses have dealt exhaustively with such broad theoreticalquestions as the Walden inversion and the relationship betweenconstitution and optical activity, thwe subjects have been leftpractically unreviewed, so as t o afford more space for othertheoretical problems. Within limitations, the writer has nothesitated to devote special treatment to the subjects in which heis particularly interested, while keeping in the foreground the ideathat the Report may appeal not only to the mature researchworker, but may also be within the scope of the student who hasreached that difficult stage in his career when text-books areinsufficient and original literature too unwieldy or too difficult.Hydrocarb o m .The vigorous research which has lately been applied to theproblem of the synthesis of caoutchouc still continues t o addmaterially to the bulk of the literature, and has doubtless conveyeda certain indirect stimulus to the study of hydrocarbons generally.It must, however, be confessed that, with the exception of workwith a technical aspect, comparatively few researches on aliphatichydrocarbons can be viewed as being, in the best sense, systematicand continuous; the exceptions t o the above statement are con-sequently invested with a special interest.Further evidence bearing on the vexed question of the origin ofnatural paraffins is being gradually accumulated as the indirec56 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.result of various investigations.For example, in the last two orthree years, it has been shown that the catalytic formation ofmethane and other hydrocarbons can be brought about by a largevariety of metals which in scjme cases appear to act simultaneouslyas oxidation and reduction catalysts, and viewing these results asa whole, support is lent to the idea that processes of a similarkind are, in all probability, operative in nature. These catalyticreactions will be referred to in detail in a subsequent section, and,in the meantime, attention may be directed to another point.Theoptical activity observed in certain natural paraffins does notof necessity imply the existence, in the specimen, of active hydro-carbons of the paraffin series, and the caution with which suchobservations must be regarded is again emphasised by the resultsobtained in an examination of a technical sample of liquid paraffin.1The dextrorotatory constituents of the specimen were found t oaccumulate in the portions of higher boiling point, and these, ontreatment with nitric acid, became quite inactive. As opticallyactive hydrocarbons of the paraffin series are not affected by thisreagent, the conclusion is drawn that the original activity was dueto the presence of polynaphthenes. This is by no means anisolated observation, as other workers have obtained similar results,and it is evident that further reBearch on this important problemis necessary before even superficial generalisations can be made ast o the origin of natural paraffins.Before leaving the subject of saturated hydrocarbons, attentionmay perhaps be drawn to a convenient method of preparing puremethane.2 The process consists in decomposing aluminium carbidewith water, and, after absorption of acetylene in the usual manner,the free hydrogen is removed by direct union with oxygen.Theproduct, as finally purified, was shown to be free from bothhydrogen.and oxygen, and, considering the importance of puremethane as a test substance in researches on the mechanism ofcombustion, the method will doubtless find many applications.With the exception of papers of a purely technical nature, com-paratively few publicatioiis have recently dealt with unsaturatedhydrocarbons, but the question of the structure of halogen sub-stitution products of acetylene has been re-opened by Biltz, whoexpresses concern that Nef’s ideas regarding the nature of thesecompounds should pass into the permanent literature without moredefinite proof.3 1, number of arguments are submitted in favourof the view that dihalogen derivatives of acetylene are to beJ. Marcusson and C. Vielitz, Chem. Zeit., 1913, 37, 550 ; A., i, 581.C.Campbell and A. Parker, T., 1913, 103, 1292.Ber., 1913, 46, 143 ; A , , i, 241ORGANIC CHEMISTRY. 57regarded as constituted according to the simple structure CXiCX,and many objections are offered to Nef’s alternative formulae,CX,:@> and CX,:C<. The paper gives a summary of the some-what unexpected reactions of these compounds which may proveuseful. Several other publications have been concerned with thenature of the compounds formed by the union of acetylene withvarious metallic salts, but, naturally enough, the evidence regardingthe structure of these substances is somewhat scanty, and no usefulpurpose would be served by discussing the results in detail.An example of the synthesis of an acetylenic hydrocarbon,through the agency of diquaternary ammonium bases, is instructiveas furnishing a convenient method of increasing the unsaturationof a hydrocarbon.* Starting from the dibromide of butadiene,a8-tetramethyldiamino-AB-butylene, NMe,*CH&H:CH*CH,*NMe,,was obtained by the action of dimethylamine. The correspondingdiquaternary ammonium base, when heated under diminishedpressure according to the modern method of conducting suchdecompositions, yielded vinylacetylene, CHI C*CH: CH,, as theessential product.The distribution of valencies in a compound ofthis description offers many possibilities for research, but, as theboiling point of the hydrocarbon is low, the experimental difficultieslikely to be encountered may limit its examination in greaterdetail.Caou tchouc.-Much ingenuity continues to be expended on theproblem of preparing isoprene and similar hydrocarbons, and thereferences on this topic to be found in the patent literature are noless numerous than last year.Little would be gained by anyattempt t o systematise these methods, as no process seems tooimprobable to merit publication or registration. There is, however,a growing tendency to fall back on metho4s which depend oncatalysis for the preparation of unsaturated hydrocarbons generally,and doubtless in this direction lies the successful reaction to thediscovery of which so much research is being devoted. On theother hand, considerable progress had been made in attempts t ogain an insight into the nature of the caoutchouc complex, andthe main result is the identification of an eight-carbon ring as theessential part of the structure.By saturation of a chloroform solution of natural caoutchoucwith hydrogen chloride, bromide, or iodide, definite additionproducts corresponding with the formula Cl,H16,2HX can be pre-cipitated by the addition of alcohol.6 It is pointed out in theoriginal paper that, although similar products are obtained fromR.Willstntter aiid T. Wirth, Bw., 1913, 46, 535; A., i, 330.C. D. Harries, ibid., 733 ; A . , . i, 38058 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.caoutchouc prepared from isoprene, the additive compound withhydrogen iodide contains only one molecule of the halogen acid. Atthe same time, it would appear thAt the dihydriodide is formedonly with dificulty, as in a parzllel research on natural caoutchouc,in which similar methods were used, only the monohydriodide,C,,,HIG,HI, was isolated.6 The halogen hydride present in theseadditive compounds may be removed by the action of pyridine,and the products thus obtained are not identical with natural/caoutchouc, but reaemble the substance prepared from isoprenethrough the agency of sodium.If, however, the removal of thehalogen acid is effected by treatment with alkalis, an entirelydifferent form of caoutchouc is formed. I n view of the fact thatthese " regenerated caoutchoucs " react imperfectly with ozone, ithas, in the meantime, been suggested that their molecules includea conjugated system of double linkings, and the following formulzehave been proposed:It is important t o notice that the above structures are based onthe idea that caoutchouc, and substances of a similar nature, arederived from eight-carbon rings.Harries, who has recentlydevoted considerable attention to this aspect of the structuralquestion, has compared the velocity of decomposition of the ozonideof '' normal " butadiene-caoutckouc with that derived fromA1 :5-cycZooctadiene. Both compounds were found to decomposea t the same rate to give practically identical amounts of succindi-aldehyde. As Harries has 1 epeated-ly shown, the decompositioncurves of ozonides constitute excellent standards of comparison,and the reasonable conclusion from the experiment just mentionedis that the caoutchouc complex is an aggregate of eighbcarbonrings.' Additional evidence of a more direct nature was obtainedfrom a series of reactions in which caoutchouc, regenerated fromthe hydrochloride, was converted into the ozonide, which was heatedwith water at 1 2 5 O .Several products were thus obtained, notablylevulinaldeliyde and cyclooctane-1 : 5-dione, and the following inter-pretation of these changes is suggested :Natural caoutchouc.One form of regenerated caoutchouc.F. W. Hinrichsen, H. Qnensell, and E. Kiudscher, Bcr., 1913, 46, 1283 ; A . ,i, 637. 7 C, D, Harries, Annalen, 1913, 395, 211 ; A . , i; 284ORGANIC CHEMISTRY. 59One feature of the paper now under review is the claim, basedon the comparison of the decomposition curves of ozonides, that“ sodium ” caoutchouc derived from both isoprene and butadienesources is essentially different in structure from the naturalcompound.Needless to say, many investigations continue to deal with suchproblems as vulcanisation and the direct addition of oxygen t ocaoutchouc, and the recent recognition of the part played by thenitrogenous constituents has also received considerable attention,but the progress made in these inquiries does not call for specialmention.Alcohols, Aldehydes, and Hetoices.With one notable exception, few investigations of the past yearhave dealt exclusively with alcohols of simple structure. Theexception referred to is the preparation of a large number ofoptically actdve alcohols of the type Et-CH(0H)-R, and although,for reasons stated in the introduction, it is not proposed on thepresent occasion to discuss optical results, the latest contribution tothis irnportant and well-developed series of investigations shouldnot pass unmentioned.8I n last year’s Report reference was made to the success whichhas attended the efforts of Wohl and his pupils in the synthesis ofdialdehydes, and i t was pointed out that work with compounds ofthis nature is greatly hampered by their tendency to polymerise.It may be noted that this change ha?.in many cases been tracedto the presence of moisture.9 Thus, on distilling glyoxal whichhad been dried- over phosphoric oxide a t 9 5 O , the unimolecularcompound was obtained, and this is in agreement with a similarresult obtained by Meisenheirner in the case of methylglyoxal.10A somewhat drastic, but apparently efficient, method for reducingaliphatic aldehydes and ketones to the corresponding hydrocarbonsdepends on the action of amalgamated zinc in presence of con-centrated hydrochloric acid.11 The process has been applied suc-cessfully to heptaldehyde, which gives a good yield of Yc-heptane,and even better results have been obtained with ketones, where,in some cases, the yields are practically quantitative.As thereaction appears to be superior In many respects to that in whichsodium and absolute alcohol are employed, its applications shouldbe both numerous and important.The reactions of #?-ketonic esters continue to yield interestingR.H. Pickard and J. Kenyon, T., 1913, 103, 1923.C. D. Harries, Ber., 1913, 46, 294 ; A . , i, 342.E. Clemmensen, ibid., 1915, 46, 1837 ; A , , i, 733.lo J. Meisenheimer, ibid., 1912, 45, 3635 ; A . , 1912, i, 83160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.results, and a new method has been described for preparing thesecompounds by a modification of Reformatski’s reaction. Thus,the action of amalgamated zinc on a mixture of ethyl ethoxy-acetate and ethyl bromoacetate resulted in the formation of ethyly-ethoxyacetoacetate, and a number of more complex examples arequoted in the original paper.12 I n this connexion, it may be notedthat a recent study of the decomposition of &ketonic esters showsthat certain of these compounds, when heated a t 200° with a smallproportion of water, undergo ketonic decomposition in practicallya quantitative manner.lS It is significant that only those &ketonicesters which are capable of undergoing enolisation can participatein the reaction, and this excludes the suggestion that the processdepends simply on the hydrolysis of the ester and the subsequentelimination of carbon dioxide.Apparently the facility of thedecomposition varies directly with the tendency of the ketonicester to enolise. The suggestion is made that the reactions proceedaccording to the general scheme:I120R*CO*CH,*CO,R/ -+ R*CO*CH:C(OH)*OR/ +R*CO*CH., + CO, + R/*OH,and in the original paper some results are quoted in support ofthis view.Another interesting series of reactions which throw light on theenolisation of simply constituted ketones is described by Favorski.14By the action of phosphorus pentachloride on diisopropyl ketone,he finds that the customary replacement of the carbonylic oxygenby two atoms of chlorine only takes place t o a limited extent, andthe main product of the reaction is isopropyl a-chloroisopropylketone, CMe,Cl*CO-CHM%.Moreover, products of the above type are invariably produced bythe action of phosphorus pentabromide.The nature of the reactionwhich ensues when a ketone is acted on by a phosphorus haloidwoulci thus appear to depend on the capacity of the ketone toundergo enolisation. When the normal ketonic structure persists,two halogen atoms are introduced into the carbonyl group, and,on the other hand, when the conditions employed are favourableto enolisation, the following scheme represents the sequence ofchanges :CHR,*CO*CHR, + CR,:C(OH)*CHR, + CR,Cl*CO*CHR2.The generalisations made in the original paper are based on apraiseworthy number of bxperimental results.T. B.Johnson, J. Anter, C‘hem. sbc., 1913, 35, 582 ; A., i, 587.13 H. Meerwein, AnmaZen, 1913, 398, 242; A., i, 858.14 A. E. Favorski, J. Buss. Phys. Chem. SOC., 1912, 44, 1339 ; A . , i, 12ORGANIC CHEMTSTRY. 61A variation of Rnorr's method of synthesising pyrrole clerivativesis involved in the condensation of amino-ketones wit11 esters of&ketonic acids in alkaline solution,15 and a simplification of theprocess consists in the replacement of the ketonic esters by ketones.I n this way, acetone and aminoacetone react to give 3 : 4-diniethyl-pyrrole, and a similar result has been obtained by the interactionof aminoacetone and ethyl oxalacetate.The use of sodamide, in conjunction with alkyl iodides, as analkylating agent has been extended to aliphatic ketones, andalthough the process was in the first instance applied to cases, suchas pinacoline, where a tertiary carbon atom is attached to thecarbonyl group, it seems to be capable of general application.16 Asa typical example, the action of the alkylating agent on diethylketone may be given. The products in this case consisted essentiallyof ethyl isopropyl ketone and diisopropyl ketone, thus indicatingthat the reagent had affected successive substitution on either sideof the ketonic group.A property which seems to be characteristicof alkylated ketones, and which may be noted, is their failure t oform oximes or other similar derivatives. Another method ofalkylation, originally designed f o r cyclic ketones, has now beenshown to be alqo applicable t o certain aliphatic compounds.l7 Theprocess, which has been developed by Kiitz and Blendermann,consists in condensing the ketone with ethyl oxalate, heating thesodium derivative of the ketonic ester thus produced with analkyl haloid, and finally hydrolysing with alkali hydroxides. I nthe meantime it is perhaps premature to claim the method as oneof general application in the aliphatic series, but, from the experi-mental point of view, it evidently possesses many advantages.As is well known, the use of acetone as a solvent and a reagentis greatly influenced by the presence of impurities, and aneconomical method of purifying the commercial product will bewelcomed. The fact that sodium iodide unites with acetone togive a crystalline compound, NaI,3C3H,0, has now been appliedt o the purification of the ketone on the laboratory scale, andinspection of the working details given in the original paper 18 showsthat the method is both convenient and efficacious.Tautornerism.During the past three or four years the experimental study oftautomeric phenomena has been greatly extended, and previousl5 0.Piloty and P. Hirsch, Annctlcn, 1913, 395, 63 ; A., i, 292.l6 A.Haller and E. Bauer, Ann. Chim. Phgs., 1913, [viiiJ, 29, 313 ; A . , i, 829.l7 A. Kotz and K. Blendermznn, J . p ~ . Chem., 1913, [ii], 88, 257 ; A., i, 1069.l8 Miss K. Shipsey and E. A. Werner, T., 1913, 103, 125562 ANNUAT, REPORTS ON THE PROGRESS OF CHEMISTRY.Reports coiitaiii copious references to the more recent developmentsiii this field. A t the present time, comparatively few confpoundsof a purely aliphatic nature appear to be employed in extendingour ideas of the keto =en01 transformation, and the subject thusfaIls naturally within the compass of another section of the Reports.Special attention should be drawn, however, to a paper dealingwith the more recent results obtained by Meyer in his systematicstudy of tautcmeric change, as, apart from the new experimentalresults described, the author makes a number of useful suggestionswhich may serve to simplify the nomenclature which has crept intouse in referring to different types of tautomeric compounds.19 Healso weighs once more the claims of existing theories of desmotropicreactions, and again comes to the general conclusions that theadditive theory is probably correct, and that the enolic variety isthe more reactive form.Despite the accumulation of evidence that,in certain changes, such as bromination, reaction proceeds throughthe enolic form, rigid generalisations on this point cannot yet bemade. An interesting result bearing on this aspect of the keto-enol question has arisen, presumably as a side issue, in the synthesisof optically active spirans carried out by Leuchs.20 Starting withoptically active l-hydrindone2-benzyl-o-carboxylic acid, he obtainedan active product after bromination and subsequent action ofalkali.The conclusion is drawn that the bromination of theoriginal acid must have taken place to a certain extent directly andwithout preliminary enolisation of the keto-group, as, otherwise, theasymmetry would be destroyed in the process, and the final productwould have necessarily been inactive. This isolated result is notin itself conclusive, and may be explained on the assumption thatthe ketonic acid is associated t o some extent, in which case theseries of reactions can be regarded as involving a “partial asym-metric synthesis.” 21Other work which bears on the application of the addition theoryhas shown that not only does hydrogen bromide convert acetylchloride into acetyl bromide, but that the converse reaction,brought about by hydrogen chloride, results in the formation ofacetyl chloride from the bromide.22 The idea is again put forwardthat this result can be best explained by the supposition that ineach case the additive compound CTH,-C(OH)BrCI is formed, andthis may part with either hydrogen chloride or bromide, accordingto the conditions.Extending this explanation to the brominatioiil9 K. H. Meyer, Annaten, 1913, 398, 49 ; A., i, 704.H. Leuchs, Ber., 1913, 46, 2435 ; A., i, 974.A. Lapworth, P., 1913, 29, 289.22 0. Aschan, Ber., 1913, 46, 2162 ; A., i, 820 ; H. Staudinger and E.Anthes,Ber., 1913, 46, 1417; A., i, 616ORUANIC CHEMISTRY. 63of acid chlorides, i t will be seen that the same intermediate com-pound will result, irrespective of the route followed by the reaction :(I) Bromination by substitution :C"H,*COCl+ Br2 + CH,Br*COCl+ HBr + @H,Br*CClBr*OH.(11) Bromination b y addition :CH,*COCl-+ CH,:C(OH)Cl+ CH,Br-CClBr*OH.The results of this research do not materially affect the positionof the addition theory, and certainly dispose of the objections to i traised in a paper describing the formation of butyryl bromide frombutyryl chloride by the action of hydrogen bromide.23A new departure in the experimental treatment of tautornericchange, which may prove useful in the future, is marked by theadoption of ozone as a reagent.24 The advantages of the processlie in the facts that the addition to the enolic form proceeds a tlow temperatures, and apparently without inducing structuralalterations in the substance under examination.As a specificexample, a chloroform solution of benzoylacetone was treatedwith ozone, and the ozonide decomposed with water. The productsconsisted of benzoic acid in almost quantitative amount, togetherwith methylglyoxal, which was isolated in the form of the osazone.Direct evidence is thus obtained pointing to the fact that, out ofsix possibilities, benzoylacetone is, under the conditions of theexperiment, enolised according to the formula :OH*CPh:CH*CO*CH,.The same result has already been indicated by observations of themagnetic rotatory power of chloroform solutions. Other examplesof the application of ozone are furnished by oxalacetone and ethylacetoacetate.I n the former case, a yield of 93.5 per cent. of oxalicacid was obtained on decomposing the ozonide, from which it wouldappear that the enolisation had also involved the acetyl group tosome extent. The ozonide of ethyl acetoacetate was produced onlyin small amount, and the products of molecular rupture corre-sponded with those t o be expected from the enolic modification.Unfortunately, although it is stated in the original paper that thespecimen of ethyl acetoacetate was enolised to the extent of about8 per cent., no details are given as to the yield of ethyl phenyl-hydrazoneglyoxylate. This is probably unavoidable in view of thesmall scale in which such experiments are carried out, but furtherinformation on this point is of evident importance, in view of theclaim that the reaction with ozone does not affect the proportionsof the two forms, and is confined to the enolic variety.A. Michael and E.Scharf, BeT., 1913, 46, 135 ; A , , i, 246.24 J. Scheiber and P. Herold, ibid., 1105 ; A, i, 49064 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Exclucliiig processes depending on the iise of optically activesolvents, polarimetric methods of studying the keto-enol changemust of necessity be of limited application and suffer from severalrestrictions. Evidently when the labile hydrogen atom is linkedto the asymmetric carbon atom, one factor necessary for quantitativework of this description is the independent existence of an activemodification of the ketonic form.On the other hand, in the specialcase of acids, i t is possible t o trace the tautomeric changes bypolarimetric observations on optically active derivatives, such asesters, and an interesting study of this nature is reported.I-Menthyl d-phenylacetoacetate exists in the solid state as theketonic modification, and is initially dextrorotatory in benzenesolution. The activity gradually alters to laevorotatory, and ulti-mately the permanent rotation is entirely due to the presence ofthe I-menthyl group. The velocity of the change varies greatly,and, as in ot’her similar cases, this can be attributed to the actionof alkaline catalysts, and several instructive examples are quotedshowing the effect of piperidine in promoting the change, evenwhen the mutarotation remains under ordinary conditionscompletely suspended.25From a spectroscopic examination of various substances con-taining labile hydrogen atoms, it has been shown, in the case ofcompounds which give only general absorption in alcoholic solutionbut display banded absorption in the presence of alkali, that thepersistence of the bands depends on the amount of alkali present.26This result is in agreement with that arrived a t by Hantzsch insimilar work on ethyl acetoacetate, and, in view of the numberand nature of the compounds now examined, would appear to begeneral.The evidence accumulated in this and similar investi-gations supports the conclusion that the bands are the spectra ofalkali salts derived from the grouping *CO*CH,*CO*, but it shouldbe noted that the .existence of bands is limited to cases where theformation of internal complex salts seems probable.Incidentally,as a side issue of the general investigation, i t was ascertained thatspectroscopic evidence is opposed to the idea that a disodium com-pound of e t h y Im a1 on a te exist s.27Catalysis.I n previous Annual Reports, considerable space has been devotedto the subject of catalysis, and it is more than ever evident;, a tthe present time, that researches on catalytic reactions are being2o H. Rupe and E. Lenzinger, AnmaZen, 1913, 398, 372 ; A., i, 884.26 P. J .Hrannigan, A. K. Macbeth, and A. W. Stewart, T., 1913, 103, 406.?7 A. K. Macbethand A. W. Stewart, P., 1913, 29, 11ORGAN I C C H EM 1 ST KY. 65prosecuted with a vigour which has seldom been surpassed in thehistory of organic chemistry. A scrutiny of the abstracts of paperspublished during the past ten or twelve years shows that thisdevelopment has gradually been gaining strength, and it is signifi-cant that a large proportion of the researches under this headingare now described in the patent literature rather than in scientificpublications. The past year has been unusually fruitful in thenumber of new applications of catalysis, and in the bewilderingvariety of catalytic agents which have been successfully employed.Beduction.-Considering the fact that distinct schools of researchare now associated with reactions involving catalytic reduction, itis not surprising t o find that many important results of this naturehave to be reviewed.Catalytic reductions naturally fall under twoheadings : (a) those conducted at high temperatures, the reducedproduct being generally removed by distillation ; and ( b ) reductionscarried out in the liquid state o r in solution a t moderate tem-peratures. Processes of the latter type, when available, are formany reasons to be preferred, and a t the present time seem toengage most attention.In an important paper describing the reduction of unsaturatedaldehydes and ketones,28 Ipatiev mentions that he failed to reduce/3-methyl-~-ethylacraldehyde by Ski ta’s process, and admits that theuniversal method for the hydrogenation of organic compounds isstill to be found.His own process, in which reduction is effectedby the joint action of finely divided nickel, or palladium, andhydrogen under pressure, continues nevertheless to give highlyinteresting results. A notable feature of the work is the steadyincrease of the pressures employed. Thus, under a hydrogenpressure of 116 atmospheres, and in the presence of palladium ascatalyst, acetylacetone is reduced to amylene PG-glycol,CH,*CH (OH) CH,*CH (OH) CH,.Under similar conditions, but substituting nickel for palladium, theaction was incomplete, and the reduced product consisted of methylfJ-propyl ketone. This is an unexpected result, and emphasises thefact that the action of nickel, when applied in this way, is some-what irregular, the efficiency of the catalyst in some cases beinginferior, and in others superior to that of palladium.An interesting application of Ipatiev’s method is found in thereduction of carbohydrates.Aqueous-alcoholic solutions ofreducing sugars may be hydrogenated at l l O o by the agency ofpalladium and under a hydrogen pressure of 100 atmospheres. I nthis way laevulose was reduced t o d-mannitol, dextrose t o d-sorbitol,whilst lactose gave dulcitol as the essential product.29 Inspection28 Ber., 1912, 45, 3218 ; A , , i, 10. ‘L9 L O C . eit.REP.-VOL X. 66 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the experimental details shows that in the two first-mentionedcases the yields appear particularly good, and the result will bewelcomed, as reduction methods and, incidentally, oxidationmethods also, are not particularly numerous in the sugar group.Another useful application of the process consists in the conversionof cyclic ketones into the corresponding saturated hydrocarbonsby the joint action of reduction and dehydration catalysts.30Reactions of this type belong t o another section of the Reports,but are of general interest in indicating the possibilities attendingthe use of mixed catalysts.From the experimental point of view, the method of hydrogen-ation now being developed by Skita and his co-workers is exceedinglysimple, and has proved of great service.The special advantageof the process lies in the fact that the reduction proceeds a t theordinary temperature and under pressures which rarely exceedone atmosphere.It is thus, as a rule, possible, as with Paal’smethod, t o follow the course of a reaction, and to arrest a reductiona t intermediate stages if desired. A useful review31 of the workingdetails shows that the use of gum arabic may be applied, not onlyto the production of colloidal solutions of palladium, but also tothe formation of palladous hydroxide in a colloidal condition.These colloidal hydroxide solutions seem well suited to certainspecific reduction processes, and, although the paper referred todeals principally with the hydrogenation of cyclic compounds, theworking details given are of a general nature.The efficiency ofthe process has been somewhat increased by taking advantage ofthe fact, previously established, that reductibn takes place morereadily in certain solvents than in others, and also by increasingthe hydrogen pressure slightly.32It would appear that in many cases the action of platinum blackas a catalytic agent in hydrogenation is highly effective, and maybo superior t o finely-divided palladium.33 Thus, acetylenic y-glycolsmay be reduced in presence of platinum to the saturated glycol (I),together with the corresponding alcohol (11) :(I) OH*CRR’*[CH,],*CRR’*OH. (11) OH*CRR’*[CH,],-CHRR’.Curiously enough, the corresponding hydrocarbon is not formedas the ultimate reduction product.The important problem of converting unsaturated fats and fattyacids into the related saturated compounds has been unusuallyprominent during the past year, and has been carefully studiedV.N. Ipatiev, Ber., 1922, 45, 3205 ; A., i, 65.J1 A. Skita and W. A. Meyer, ibid., 3579 ; A . , i, 53.32 Ibid., 3589 ; A . , i , 54.a G. Dupont, Contpt. rend., 1913, 156, 1623 ; A., i, 696ORGANIC CHEMISTRY. 67in the laboratory, and elsewhere. A variation of the customaryprocess, in which reduced nickel or other metal is used as thecatalyst, is reported by Bedford and Erdmann, who find that nickeloxide is peculiarly effective.34 Not only so, but the oxide possessesan additional advantage over the metal in that it is less readilyaffected by hydrogen sulphide. The mechanism of the processseems to depend on the conversion of the higher oxides into thesuboxide, which forms a black colloidal suspension with the oilor fat.Excluding the entries in technical or patent literature, i t isevident that the number of publications dealing with Sabatier andSenderens' method of reduction are now less numerous than haslately been the case.Among recent publications may be noted anaccount of the behaviour of heptyl alcohol when reduced a t 220°in the presence of nickel.35 The products consisted of about 62 percent. of n-hexane, 17 per cent. of a mixture of heptyl alcohol andthe corresponding aldehyde, together with carbon monoxide. Thecomplete results of the investigation go to show that the first stagein the reaction consists in the decomposition of the alcohol intoheptaldehyde and hydrogen.The aldehyde is then converted into~hexylene, which undergoes further reduction into n-hexane. Theinvestigation deserves special mention in view of the systematicattempts which were made t o trace the individual steps in theseries of reactions.Simple methods for synthesising methane by catalysis have, ofcourse, been known for some time, and several investigations havenow been devoted to elucidating the reactions involved in theseprocesses. It would appear that the conversion of carbon mon-oxide and water into methane can be effected by a great varietyof metals or oxides, but metallic nickel a t 600° gives the bestresults. Apparently metallic iron, alumina, and silica act throughthe temporary formation of carbides, which are at once decomposedby the water vapour t o give the hydrocarbon.36 It may also benoted that Ipatiev has come to the opinion that the direct synthesisof methane from its elements, in the presence of metals, dependson the catalytic oxidation of the carbon by means of metallic oxidespresent as impurities.The carbon dicxide produced is then reducedcatalytically to methane, so bhat the series of reactions dependson joint catalytic effects.370 they Examples of Catalysis.-Methods of preparing ketones34 J. pr. CJbem., 1913, [ii], 87, 425 ; A., i, 701.:j5 J. Bijeseken and G. H. van Sentlen, Eec. t r m . chim., 1913, 32, 2 3 ; A., i. 331.3: J. pr. Chew., 1913, [ii], 87, 479 ; A., i, 693.L. T i p o n , G'onzpt. reucl., 1913, 157, 131 ; A!., i, 949.F 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which depend on the catalytic action of metallic oxides orcarbonates on organic acid5 are daily becoming more numerous,and Senderens, who has been associated with this developmentduring the past four or five years, has lately published a usefulsummary of the abundant literature which has accumulated roundthe subject.38 It has now been shown that precipitated calciumcarbonate is a useful catalyst in this type of reaction, and, althoughnot so effective as thorium oxide, it retains its activity even afteri t has become coated with carbonaceous products.39 The yield ofketone obtained by this agency is, however, satisfactory only in thelower members of the aliphatic series, but even valeric acid givesa 32 per cent.yield of dibutyl ketone. I n every case the acidsmay be replaced by their anhydrides, and the process is alsoapplicable to the preparation of mixed ketones.At the same time, thorium oxide, as a catalyst in the preparationof ketones, is evidently superior in its range of application to anyother agent, and an instructive example of its value is given byPickard and Kenyon in their most recent account of opticallyactive alcohols.40 A number of the carbinols resolved in the courseof this important research (and also in the previous work of thesame authors) were obtained by reduction of mixed ketones, andthese, in turn, were prepared catalytically from the correspondingacids. One typical example may be quoted which shows theefficiency of the process.By passing a mixture of equal amountsof myristic and propionic acids over thoria heated to 420°, a 60 percent. yield of ethyl n-tridecyl ketone was obtained, and this resultspeaks for itself sufficiently. Incidentally, it may be mentionedthat the use of thorium oxide as a catalyst frequently givesirregular results, and it is difficult t o preserve the conditionsnecessary for any particular action. An additional example ofthis uncertainty is quoced by Baskerville, who states that althoughhe observed all the conditions laid down by Sabatier and Mailhe,he nevertheless failed t o obtain ethyl ether by the action of purethorium oxide on alcohol vapour a t 250O.41It has been known for some time that glucinum salts can bedissolved in various organic solvents, and this has now led to thediscovery that the ordinary process of esterification is considerablyaccelerated by the addition of glucinum acetate or hydroxide.42Better resuits were obtained when the vapours of the acid andalcohol were led over glucinum oxide heated at 310O.The products;ia Ann. Chim. Phys., 1913, [viii], 28, 243 ; A., i, 312.39 P. Sabatier and A. Mailhe, Compt. Tend., 1913, 156, 1730 ; A., i, 700.40 T., 1913, 103, 1923.41 J. Amer. Chent. Soc., 1913, 35, 93; A., i, 155.42 0. Hauser and A. Iilotz, Chem. Zeit., 1913, 37, 146 ; A., i, 246ORGANIC CHEMISTRY. 69were obtained in satisfactory yield, and the catalyst may be readilyrecovered, but, a t the same time, it is doubtful if the process ismore convenient than methods depending on the catalytic agencyof sulphuric acid, as these have now reached a high degree ofefficiency.43A rapid method of converting primary alkyl chlorides orbromides into the corresponding secondary isomerides may occa-sionally be useful, and it has been shown that the change may bebrought about by distilling the haloids over thorium chlorideheated a t 250°, and leading the products over pumice stone a t200°.44 The reaction seems to involve the temporary decompositioninto ethylenic hydrocarbons and hydrogen chloride or bromide, theproducts afterwards recombining to give the isomeric haloids.Catalytic methods of oxidation have not been specially prominentin the aliphatic series of late, but it may be mentioned thatSenderens has been engaged on a study of the direct oxidation ofalcohols as a necessary preliminary to the investigation of theeffect of metals and metallic oxides in accelerating the change.45The results so far obtained have not been specially promising, butthere is little reason t o doubt that this revival of an old reactionwill ultimately be developed on profitable lines.f l a l ogeu Co ntpounds.Systematic subdivision of the subject-matter of the Report wouldbe difficult to maintain if halogen compounds mere treated rigidlyas a class by themselves, and consequently most of the referencesto these compounds are t o be found under other headings wheresynthetical processes are discussed.So far as these practicalmethods are concerned, no specially striking development has beennoted.Alkyl and acyl haloids have found their customaryapplications ; work with Grignard reagents has been as extensiveas ever, but the reaction has now found a permanent place as astandard synthetical method, and there is no necessity to referto the many modifications of the process.I n several cases, however, researches on halogen compounds havedealt with structural problems, and many interesting results havebeen obtained. I n the course of an examination of the opticalproperties of typical monoba.sic acids and their derivatives, thevalues found f o r the refractivity and dispersive power have beencompared for the free acid, the ethyl ester, and the acid chloride.46F.Bodroux, Carnpt. rend., 1913, 156, 1079; A . , i, 440.44 P. Sabatier and A. Mailhc, ibid., 658 ; A . , i, 330.415 J. B. Senderens, ibid., 1909 ; A., i, 814.46 K. von Auwers and M. Schmidt, Ber., 1913, 46, 457 ; A., i, 33870 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Practically without exception, the values could be arranged in theorder : acid>chloridel>ester ; and extension of the determinationsto the chlorides of the oxalic acid series has shown that succinyland glutaryl chlorides must be regarded as possessing the normalsymmetrical structure. This is in conformity with the resultsobtained during the past two years by other workers who haveapproached the problem by different methods. I n the case ofchlorides derived from unsaturated acids, the results are equallyconclusive, and point to the fact that where the trans-configurationexists the resulting chloride is symmetrical.On the other hand,the optical values determined for chloromaleyl chloride clearlypoint to >** CH* CCI,cc1-co the structure I I Although in general theseconclusions are in good agreement with those arrived a t by Ott,47it may be observed that the relative positions now ascribed to thehalogen atoms are somewhat different from those previously sug-gested. It may be mentioned, in passing, that a further point ofdistinction between chlorofumaryl chloride and chloromaleylchloride consists in the fact that the former resists the reducingeffect of hydrogen and platinum black owing to paralysis of thecatalyst.The observation is interesting, but it would be prematureto claim this difference in behaviour as general in its nature orcoiinected with symmetry of structure.Acids and their Derivatives.It is somewhat rare to encounter research work which findsimmediate application in teaching, but many lecture courseswill be affected by recent work on the isomeric dibromo-succinic acids. The relationship of these compounds with meso-tartaric and racemic acids has now t o be regarded in a new light,as i t has been shown that isodibromosuccinic acid is a racemic form,and may be resolved into its active constituents.48 The followingscheme therefore represents the mutual relationships of the tartaricacids, the corresponding dibromo-acids, and t,he parent unsaturatedacids :Fumaric acid.Kz Racemic acid. ,"2" isoDibromnsuccinic acid.I \LBr2(r-fnrm. )?..2Dibromosuccinic acid. H2° Mesotartaric acid KMr'oj Maleib acid. (Meso-form . ) ---f t-Evidently the above transformations resemble those involved47 E. Ott, Annnlen, 1912, 392, 245 ; A., 1912, i, 825.48 A. Mch'cnzie, T., 1912, iol, 1196. See also P. F. Frankland, T., 1912,101, 673ORGANIC CHEMlS'fRY. 71in the Walden inversion, and two alternative explanations may beoffered. The change of configuration may take place during thereplacement of halogen by hydroxyl in the decomposition of thebromo-acids, or the addition of bromine atoms to the unsaturatedacids may follow a different stereochsmical course from the additionof hydroxyl groups by the action of permanganate.The availableevidence is in favour of the latter alternative, and i t appears likelythat the change in configuration takes place during the additionof bromine.Holmberg, who has also been en; :zed on problems similar t othat outlined above, has shown 49 that the dichlorosuccinic anhydrideobtained from maleic anhydride is a mixture of racemic and meso-forms in the proportion 5 : 1. This observation is evidently con-sistent with McKenzie's results, and i t is highly significant that thechange in configuration which accompanies the addition of halogentakes place while the anhydride structure remains intact. Afurther contribution to the stereochemistry of the halogen succinicacids shows that the formation of malic acid by the hydrolysis ofsodium Z-bromosuccinate probably takes place through the inter-mediate formation of propiolactonecarboxylic acid.The lattercompound has been found to yield eithe,r Z- or d-malic acid onhydrolysis, according as the change is effected in acid or alkalinesolution, thus adding to the already numerous list of opticalinversions encountered with these ~ubstances.5~The complicated problems connected with the chemistry of theglutaconic acids are one by one being solved as the result ofsystematic research. I n last year's Report a complete account wasgiven of the position then reached by Thorpe and his co-workersin their studies of the structural forms of glutaconic acid and itsderivatives, and consequently i t is unnecessary again to review thefundamental features of this line of inquiry.One of the pointsthen left unsettled was the provision of experimental proof thatthe normal and labile forms of a glutaconic acid possess thecis-configuration. This has now been confirmed 51 by the reductionof the two forms of ay-dimethylglutaconic acid, a substance whichis well adapted f o r this purpose. Hitherto only the normal formof the compound has been known, but the difficult task of isolatinga labile modification from the corresponding hydroxy-anhydride hasnow been carried out, so that both varieties of the acid wereavailable. After adjustment of the conditions of reduction, so ast o ensure that the process would be unaccompanied by intra.49 B.Holmberg, Suensk. Kem. Tid., 1912 ; A., i, 7.to B. Holmberg, J. pr. Chenz., 1913, [ii], 87, 456; A., i, 824.51 J. F. Thorpe and A. 8. Wood, T,, 1913, 103, 27672 ANNUAL REPORTS ON THE PROGRESS OF CIfEMISTRY.molecular changes, it was found that each isomeride was convertedinto cis-dimethylglutaric acid.Another result of more fundamental importance is the realisationof the idea, frequently emphasised in the course of these researches,that an acid of the glutaconic type should exist in three modifi-c a t i o n ~ . ~ ~ The actual compound to furnish this result wasP-phenyl-a-methylglutaconic acid, attention being directed to thisexample in view of the increased stability which follows the intro-duction of a molecularly hea.vy residue into the P-position, and theconstitution assigned t o the three isomerides is as shown below :sMe*CO,H 'yMe*CO,H EM.*CO,I tCO,H.CH, * c H co, 11 CH,*CO,~€YPh YHPh YPhtrnns-Laltile aci. I. N o r i d acifi. cis-L ibile acid.I n the course of the synthesis of the acid, a mixture of thecis- and trans-f orms of ethyl a-carbethoxy-P-phenyl-a-methyl-glutaconate was obtained, which boiled a t a constant temperature.Fortunately, the trows-variety separated in the crystalline condition,and the isolation of the substituted glutaconic acid having thesame configuration was thus rendered possible. The properties ofthe trans-labile acid are in complete harmony with the viewsexpressed regarding its structure, and the mutual relationships ofthese interesting compounds may be summarised as follows :Hydroxy-anhydridecis-Labile acidA;&+ & H3'CO c1/E'h'aOH Itrans-Labile acidNormal acid.Future work in this field will doubtless be aided by applicationof the convenient method of discriminating between the esters ofthe normal and labile acids.53 The latter type of compound alonepossesses the capacity to enter into condensation with ethyl sodio-cyanoacetate, and, except in cases where the transformation ofthe norma.1 into the labile ester occurs readily, the normal formfails t o react, The process of alkylation of ethereal glutaconates,which takes place through the intermediate formation of a sodiumderivative, is also governed by similar considerations, as alkylderivatives are only formed from the labile modifications.Workin this directioil is now so far advanced that i t has been possible52 T., 1913, 103, 1569.53 J. F. Thorp and A. S. Wood, ibid,, 1579ORGANIC CHEMISTRY. 73to effect a series of generalisations on the whole process ofalkylation, as applied t o this type of c0mpound.5~Under the heading of catalysis, special mention is made ofcatalytic methods of preparing aliphatic ketones, and it may benoted that similar methods may be employed to convert membersof the succinic acid series into the corresponding cyclic ketones.I n the meantime, the process has been confined to adipic acid, itshomologues and substitution derivatives, and it has been foundthat a quantitative yield of cyclopentanone may bs obtained byheating adipic acid to 290° in the presence of barium h y d r ~ x i d e .~ ~The reaction, which is carried out under diminished pressure andin an inert atmosphere, is evidently superior to the older methodsof obtaining such compounds by the distillation of salts, and it isin many respects unfortunate that this discovery should have beenso long delayed.I n an important paper by Scholl and Egerer, the question isrevived as t o the real nature of the oxalomalonic esters. Previouspublications contain highly contradictory accounts of these com-pounds, particularly of the ethyl ester.56 It has, however, nowbeen proved that the compound obtained by Bouveault by theinteraction of ethyl sodiomalonate and ethyl oxalic chloride, anddescribed by him as triethyl oxalomalonate, is in reality ethyloxalomethanetricarboxylate, CO,Et*CO*C(CO,Et),.Kurrein,s7 whocarried out the same reaction in benzene solution, seems to haveisolated merely a mixture of ethyl oxalate and malonate. Notonly are a number of oxalomalonic esters fully described, but ithas also been shown, in the paper referred to above, that, so longas alcohol is excluded, methanetricarboxylic esters may be employedf o r synthetic purposes in processbs which resemble those dependingon the use of ethyl sodioacetoacetate or sodiomalonate.The applications of oxalyl chloride as a synthetic agent continuet o be both numerous and important,5* and, out of many examplesof the use of this reagent, reference may be made to the synthesisof parabanic acid, together with a number of its derivatives.59 Asa rule, reaction between oxalyl chloride and carbamide takes placesmoothly in ethereal solution, and in certain cases the yieldsobtained are excellent.This is particularly the case when doublysubstituted carbamides are employed, and the reaction also applies,although imperfectly, to the preparation of thioparabanic acids.54 J. F. Thorpe and A. S. Wood, T., 1913, 103, 1752.55 D.R.-P. 256622 ; A., i, 482.56 R. Scholl and MT. Egerer, Annulen, 1913, 397, 301 ; A . , i, 588.57 H. Kurrein, Monntsh., 1905, 26, 373 ; A . , 1905, i, 413.58 See Chcm. Weckblad, 1913, 10, 214 ; A., i, 443, for a review of the literaturesince 1869. 59 H. Biltz and E. Topp, Ber., 1913, 46, 1387 ; A., i, 600'74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The possibility that oxalic acid and hydroxy-acids may play apart in the natural production of carbohydrates has again beenraised,60 and, although little evidence of a positive nature is sofar available, it may be noted that several methods are now knownby means of which oxalic acid may be reduced to glycollic acid.Further, the latter compound undergoes decomposition into form-aldehyde and formic acid under the influence of light, and thesechanges suggest a series of reactions by means of which the decom-position and the formation of sugars may be maintained as acyclic process in the plant.Work in this field has not proceededfar, but the development of the subject will be closely watched.Methods of obtaining anhydrides which depend on the use ofsulphur chloride have been known for some time, and opinionhas been divided as to the mechanism of such processes.Aninvestigation bearing on this point has recently appeared,61 whereit has been shown that the action of the reagent on the silversalts of organic acids proceeds in two stages:2R*C02Ag + S,Cl2 + 2AgCl+ (R*C02)S2.2(R*C02)S,-+ 2(R*C0),0 + SO, + 35.The anhydride ultimately produced thus results from the decom-position of an intermediate unstable compound, which may beregarded as an acyl thiosulphite. The reactions outlined above arenot only interesting from the theoretical point of view, but formthe basis of a good practical method for preparing anhydrides onthe small scale.A t the same time, the substitution of thionylchloride for sulphur chloride gives a superior working method, andthe reaction appears to be more general in its application, althoughthe capacity t o form definite intermediate compounds seems to beconfined in this case to hydroxy-acids. Theoretically, the stepsinvolved are :2R*C02Ag + (R-CO,),SO + (R*C"O),O + SO,,and, as the reactions proceed smoothly, the possibility is openedout of the preparation of normal anhydrides from hydroxy-acids.It would appear that this had already been realised in the caseof glycollic and malic acids, and a definite step has thus beenmade towards evolving a general method for the preparation ofcompounds the isolation of which is either impossible or notoriouslydifficult.It is perhaps important t o point out that when thionyl chloridereacts with certain lactones the ring is ruptured and intermediatecompounds containing both sulphur and chlorine are produced.62See also T.,E.Baur, Ber., 1913, 46, 852; A., i, 443.61 W. S. Denham and Miss H. Woodhouse, T., 1913, 103, 1861.1909, 95, 1237.P. Barbier and R. Locquin, Bull. sbc. chim., 1913, [iv], 13, 223; A., i, 336ORGANIC CHEMISTRY. 75This certainly supports the idea expressed above that the formationof thionyl derivatives from hydroxy-acids involves the hydroxylgroup.Incidentally, i t may be noted that the effect of thionyl chlorideas a chlorinating reagent leads t o variable results in the case ofoptically active compounds, save where a phenyl group is attachedto the asymmetric carbon atom.63 I n other reactions, unconnectedwith optical activity, i t has been found that many of the irregulari-ties shown by thionyl chloride can be traced to the presence ofimpurities, and as these are generally substances which are pronet o cause intramolecular changes, i t is perhaps well to emphasisethis point.64G'lycerol and A llied Compounds.At the present time, the chemistry of glycerol is evidently passingthrough a stage when special attention is being directed t oderivatives in which the hydroxyl groups are only partly sub-stituted or are replaced by different substituents. Before discussingany new synthetical products obtained from glycerol, it may bewell to refer back to results obtained a year ago in an examinationof the freezing-point curves for binary mixtures of stearin, palmitin,and olein.65 The results indicated the existence of a continuousseries of solid solutions, and this is now claimed by Holde66 asconfirming his views that in olive oil the stearic and palmitic acidsare not present as tristearin and tripalmitin, but as mixedglycerides.67 It may, however, be noted that melting-point deter-minations in the case of such compounds are liable to be vitiatedby a variety of circumstances.This is emphasised strongly byGriin, who has shown that anomalies in the consistency andmelting point of fats may be due t o the fact that certain glyceridesmay exist in two modifications, which although probably struc-turally identical, differ considerably in melting point.68There is no doubt, however, that definite mixed glycerides dooccur in solid fats, and Bomer now describes a new form ofpalmityldistearin,69 which, together with a small proportion ofstearyldipalmitin, was extracted from lard, and the same com-6s P.F. Frankland, T , 1913, 103, 720 ; A. McKenzie and G. W. Clo~xgh, T.,64 H. Meyer and K. Schlegl, illoncttsh. , 1913, 34,561 ; A . , i, 608 ; P. Barbier and65 R. Kremann and R. Schultz, Monatsh., 1912, 33, 1063 ; A., 1912, ii, 1152.66 Ber., 1912, 45, 3701 ; A., i, 158.67 Ibid., 1902, 35, 4306; A . , 1903, i, 140.68 Ibid., 1912, 45, 3691 ; A., i, 157.69 A. Romer, Zeikch. Nahr. Gcnussm., 1913, 25, 321, 364 ; A., i, 441, 442.1913,103, 687.R. Locquin, Bull.SOC. ehim,., 1913, [iv], 13, 229 ; A . , i, 33776 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.pounds have also been isolated from butter fat.T0 This line ofinquiry has naturally stimulated the synthetical production ofmixed glycerides, and, as a simple example of such work, mentionmay be made of the synthesis of a-myristo-P-stearin.71 By theaction of myristoyl chloride on glycerol-a-monochlorohydrin, theester CH2Cl~CH(OH)~CH,*O~CO*C,3H27 was obtained, and this, ontreatment with stearoyl chloride, was converted into myristostearo-chlorohydrin, CH2C1 CH (0 COO C,7H38) *CH,*O-CO*C,3H,7. Thefinal stage in the synthesis of a-myristo-P-stearin was accomplishedby the action of silver nitrite, and obvious variations in theprocesses admit of the preparation of a large number of mixedglycerides.An alternative method of obtaining an idea of the structure ofthe natural glycerides depends on the process of partial saponifi-cation of the compounds, and although sulphuric acid has hithertobeen employed as the hydrolytic agent for this purpose, it hasnow been shown that alkali hydroxides are equally effective indisplacing tihe fatty acid residues in definite ~tages.7~The use of substituted glycerols in pharmacology has in recentyears been an important factor in directing the synthesis of simplederivatives of the trihydric alcohol.I n this connexion it may benoted that the reaction between glycerol and phosphoric acid orphosphoric oxide is by no means so simple as would appear fromthe earlier publications on this topic, and, during the year, anumber of fresh observations have been made, which do not,however, lead to any final conclusions on the subject.The claimmade by Contardi that glycerotriphosphoric acid results from theaction of 3 mols. of phosphoric acid on 1 mol. of glycerol is nowcontradicted by Carre',73 and the lengthy dispute between theseworkers can apparently only be settled by approaching the problemby some entirely new route. Although a t present the whole subjectis in an incomplete state, i t deserves reference in view of itsimportance.Among derivatives of glycerol in which two hydroxyl groups aresubstituted, the compounds formed by condensation with aldehydesor ketones are of special interest. Glycerol benzylidene ether hasnow been obtained crystalline by heating glycerol and benzaldehydein the absence of a cataIyst.74 The same method has furnished atrimethylene glycol benzylidene ether, and, what is more importantfrom the structural point of view, propylene glycol also participates70 C.Amberger, Zeitseh. Nahr. Genztssm., 1913, 26, 65 ; A., i, 1040.71 A. Griin and B. Schreyer, Ber., 1912, 45, 3420; A., i, 159.72 A. Lipp and P. Miller, J. pr. Cliem., 1913, [ii], 88, 361 : A . , i, 1038.73 Compt. rend., 1912, 155, 1520; A . , i, 156.74 W. Gcrhsrdt, D.R.-P. 253083 ; A . , i, 47ORGANIC CHEMISTRY. 77in a similar reaction.hydroxyl groups attached to neighbouring carbon atom.The condensation may therefore involve theGar bohydrat es.I n &he period under review, a large proportion of the researchesin the sugar group have been concerned with the synthetic functionsof enzymes, and the results obtained are of sufficient importanceand variety to justify their treatment under a separate heading.At the same time, a considerable number of the publications ofthe past year have dealt with the application of ordinary syn-thetical processes to the sugars, and several highly interestingresearches have to be noticed.Special attention must be drawn to an investigation of funda-mental importance in which the mechanism of acrose-formation isestablished with a considerable degree of certainty.75 Fischer andTafel, in their classical synthesis of a-acrose, isolated an isomericsubstance (P-acrose), which in their opinion was allied to dl-sorbose.This conclusion has now been verified.By alkaline auto-condensation of pure glyceraldehyde, under conditions which wouldbe unlikely t o cause the a l d o s e s ketose conversion, a solid, crys-talline mixture of inactive hexoses has been obtained, from which&fructose was isolated by crystallisation from methyl alcohol.A more soluble constituent was also separated in the crystallinestate, and this was proved t o be dl-sorbose by comparison with anartificial mixture of the enantiomorphous forms. The identity wasfurther confirmed by the preparation and examination of the corre-sponding osazones. Owing to the experimental advantages gainedby working with definite solid compounds, several important pointshave been settled by the results of this investigation.The appear-ance of the ketonic group in the sugar synthesis must take placea t the triose stage, and thus the reaction is not, strictly speaking,the auto-condensation of glyceraldehyde, but resolves itself into thecondensation of glyceraldehyde with dihydroxyacetone. Limitationsare thus imposed on the number of hexoses which can possibly beproduced, and, in the original paper, it is shown on stereochemicalgrounds that the dl-varieties of fructose and sorbose should formthe essential products.Not the least striking feature of the work is the successfulmanipulation of small quantities of material, and the part playedby external collaborators in confirming the conclusions.The more recent work of Fischer and Zach on the reactions oftriacetyldibromoglucose has resulted in proving t,hat the twohalogen atoms in the compound are attached to the terminali5 E.Schmitz, Ber., 1913, 46, 2327 ; A., i, 95478 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.carbon atoms of the sugar chain, and this fact has led to theconversion of d-glucose inLo a methylpentose.76 By the action ofzinc dust and acetic acid on triacetylmethylglucoside bromohydrin,C F i Rr . CII (0 A C) * CH CH( 0 A C) C H (0 A C ) *CH OMeI 0 Ifollowed by alkaline hydrolysis, a glucosidic derivative of a methyl-pentose was obtained. This, on complete hydrolysis, gave thecorresponding sugar (termea d-isorhamnose), which proved to beidentical with the isorhodeose isolated by Vototek.In the syntheticmethylpentose the glucose configuration must evidently persistunchanged, and the following structures are consequently estab-lished :d-isoRhamnose. I-Rhamnose.CH,*~--U-$!--$!--Ctl.OH B BQHT YH pOg0- H H O H O HOH i H O H / C €1,- 7 --- y -?---?*" H -0 HI n the original paper, an interesting series of structural formulaeserves to summarise the more important derivatives which havebeen prepared from triacetyldibromoglucose, and it is evident thatthe synthetic applicatioiis of this substance are by no meansexhausted.The investigation reviewed above naturally suggests the appli-cation of reduction to other types of halogen derivatives of sugars,and this has already been carried out.77 Acetobromoglucose, whenacted on by zinc dust and acetic acid, yields a compound of a newtype, to which the formula C12H1607 applies.This product, termedacetoglucal, still contains three acetyl groups, and its behaviourtowards bromine suggests the presence of an ethylenic linking.Removal of the acyl groups gives rise to glucal, C,H,O,, whichshows the properties of an unsaturated aldehyde, and to whichthe following formula is provisionally ascribed :HO*CH,*CH*CH:CH*C H-UHOI--.- 0 2Acebbromogalactose and acetobromolactose behave similarlywhen reduced, and the change is evidently complex, and involvesunexpected alterations in the sugar molecule. Naturally enough,the application of reduction processes t o the chloraloses has led tono very definite results.78A new experimental method which may prove of service in76 E.Fischer and K. Zach, Bcr., 1912, 45, 3761 ; A., i, 164.77 E. Fischer and K. Zach, flifzungsber K. Aknd. Wiss. BedI;ra, 1913, 311 ; A., i,78 M. Hanriot and A. Kiing, Conapt. r e d , 1915, 156, 1380 ; A., i, 593.445ORQANIC CHEMISTRY. 79determining the arrangement of hydroxyl groups in space is basedon the well-known fact that orthoboric acid may be titrated in thepresence of polyhydroxy-cornpounds.79 It has now been shown thata pronounced exaltation in the conductivity of the acid is occasionedonly by compounds containing a t least one pair of hydroxyl groups,which are attached t o neighbouring carbon atoms. Further, themaximum effects are obtained when the hydroxyl groups aresituated 011 the same side of the carbon atoms, and lie in the sameplane with them.One immediate result of the research is theallocation of definite configurations to a- and P-glucose. Of thetwo forms shown below, the compound possessing the configurationA should show a greater exaltation in the conductivity than B.OH HA.H O ~ H ,B.The two conductivity values should not, however, be permanent,as, owing to the interconversion of the sugars, one ought to diminishand the other increase until they coincide, when both forms ofthe sugar attain equilibrium in solution. These deductions wereexperimentally verified, and the configuration A thus ascribed toa-glucose. An important observation which strengthens thevalidity of the conclusions is that the velocity constants for theconductivity changes were identical with those determined for thesimultaneous changes in rotation.The investigation just referred to emphavises in a novel mannerhow the reactions of a sugar are influenced by the configurationof the hydroxyl groups, and this is also shown in the varyingcapacities of the sugars to form condensation compounds withaldehydes and ketones.Views similar to those formulated byBoeseken have also been expressed in coiinexion with the pre-paration of a series of partly methylated glucoses.80 Incidentally,in the course of the latter work, evidence bearing on the applicationof Hudson’s generalisation, regarding molecular rotations in thesugar group, has been gained by a study of the mutarotationdisplayed by dimethylglucose. Owing to the fact that the com-pound showed suspended mutarotation, i t was possible to obtainJ.Boeseken, Ker., 1913, 46, 2612 ; A . , i, 1147.J. C. Irvine and J. I?. Scott, T., 1913, 103, 564, 57580 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.exact values for the specific rotations of the a- and P-forms, andthese were found to agree closely with the figures required byHudson’s method of calculation. It may be remarked that theconstitution assigned t o dimethylglucose is still uncertain, in viewof the conclusions recently arrived a t by Macdonald in a carefulstudy of the condensation of glucose with acetone.81As the examination of natural products attracts numerousworkers, a considerable number of new glucosides have beendescribed during the year, but, generally speaking, there is nofeature of these compounds which merits special attention in thissection of the Report except that their varied compositionemphasises the variety of substances which may exist in combinationwith the sugars.As an index of the high molecular magnitude ofthese natural glucosides, reference may be made to cauZosaponiiLand caulophyllosaponin, to which the formulae C,H8,0,, andC,,H,,O,, have been respectively assigned.82It is interesting to note that evidence is accumulating pointingto the fact that mannitol seems in many cases to be a fermentationproduct derived from txehalose, and its formation may be avoidedby preserving plant extracts under sterilised conditions.83 84 Thestatement that mannitol is formed on drying certain sea-weeds85 isnot inconsistent with this view, as several years ago the writerhad the opportunity of observlng specimens of Laminaria whichhad become encrusted with mannitol after the cessation of activebacterial action on the surface of the thallus.I n connexion withreferences to natural products, it may not be out of place tomention a short paper by E. 0. von LippmannsG on the occurrenceof trehalose and d-sorbitol, as, apart from the inherent interest ofthe observations, it is instructive t o notice that the organic chemiston holiday may rival the biologist in the use he makes of hisopportunities in the field.Alkaloidal glucosides as a class are not numerous, and twoexamples of such compounds which have been recently synthesisedmay be referred to.By the use of acetobromoglucose in thestandard method of synthesis, a definite morphine glucoside hasbeen prepared,87 and, in their work on bromotriacetylglucosamine,Irvine and Hynd isolated morphine glucosamine, which is thes1 J. L. A. Macdonald, T., 1913, 103, 1896.s2 F, B. Power and A. H. Salway, ibid., 191.83 F. Busolt, J. Landw., 1913, 61, 153 ; A., i, 803.Ibid., 1912, 60, 393 ; A., i, 235.85 H. Kylin, Zeilsch. physiol. Chcm., 1913, 83, 171 ; A’., i, 435.8g Ber., 1912, 45, 3431 ; A , , i, 150.C. Mannich, Artnalcn, 1912, 394, 223 ; A., i, 87ORGANIC CHEMISTRY. 81corresponding amino-compound.88 I n addition t'o the above, a largenumber of other new glucosides have been described, in the courseof the past year, which have also been prepared through theagency of acetobromoglucose.Mention should be made of a seriesof terpene glucosides,89 as work of this nature is of obviousimportance in view of the possibility that certain terpenes andsugars may have a common origin. I n this connexion, it is perhapsnot unimportant that terpenes and reducing sugars are occasionallyencountered in the degradation products of naturally occurringsubstances.90Another important series of syntheses, also carried out by meansof acetobromoglucose, has resulted in the formation of the glucosidesof sitosterol, cholesterol, and other closely related hydroxy-com-pounds.9' The sitosterolglucoside was found to possess propertiesclosely resembling the phytosterolines, and although the otherglucosides described have not yet been detected among naturalproducts, their characterisation may well prove useful in facilitatingfurther research on the occurrence of carbohydrate complexes inplants.As usual, a considerable number of publications have dealt withthe subject of photosynthesis, and the majority of the researchesunder this heading have been directed towards duplicating thereactions involved in the natural formation of plant products.Generally speaking, it may be said that much of the recent workon the distribution of formaldehyde in plants, and the trans-formations undergone by the compound under the action of light,supports the idea that the aldehyde is the original source of thesugars, but that the condensation requires light energy.An astonishing result is reported by Stoklasa, who, along withhis collaborators, has been engaged for several years in studyingthe influence of ultra-violet rays in promoting the reduction ofcarbonic acid.92 I n a prolonged experiment, carried out with agenerous supply of material a t the radium factory a t Joachimsthal,the effect of radium emanation in influencing this change has beenascertained.H e finds that hydrogen and carbon dioxide react inthe presence of potassium hydrogen carbonate to give formaldehyde,which polymerises to a mixture of reducing sugars. The latterwere converted into the phenylosazones, which, on crystallisation,89 T., 1913, 103, 41.w E. Sieburg, Arch,.Pharm., 1913, 251, 154 ; A . , i, 639.9l A. 1%. Salway, T., 1913, 103, 1022.92 J. Stoklnss, J. gebor, and W. Zdob11ick3;, C'ornpt. rend., 1913, 156, 646 ; A.,J. ITamaliiinen, Biochem. Zeitsch., 1913, 49, 398 ; 50, 209 ; A . , i, 497, 639.i, 342.REP.-VOL. X. 82 ANNUAL REPORTS ON 1HE PROGRESS 9 F CHEMISTRY.were separated into two distinct fractioas. So far, the results areconsistent with those of other researches, but the important claimis made that the sugars formed are optically active and give[a], + 17.58O. Scrutiny of the experimental details reveals the factthat this statement is based on a very small polarimetric readingdetermined on a solution containing about 1 per cent. of (pre-sumably) active material, and, in the meantime, most chemistswill share the hesitation, expressed in a footnote t o the originalpaper, with which Maquenne received this highly abnormal result.GkLcosamiue.-The chemistry of glucosamine continues to attractattention, and a considerable amount of progress has been made.I n last year’s Report, the conversion of the amino-sugar intod-glucose was described, and recently a brief account of a secondmethod of removing the amino-group has been given.93 Methyl-glucosamine, when condensed with benzaldehyde in presence ofhydrogen chloride, was converted into benzylidenemethylglucos-amine hydrochloride. This compound, when acted on with analkaline solution of sodium nitrite, was converted into abenzylidenehexose, and the final step in the series of reactions wasthe removal of the benzylidene group by the action of dilute acid.Contrary t o expectation, the hexose formed was d-mannose.Asglucosamine may thus be converted into either d-glucose ord-mannose, a change of the nature of a Walden inversion musttake place in one of the processes. I n the meantime, it wouldappear that there is no necessity to modify the views previouslyexpressed, in which glucosamine is regarded as a derivative ofglucose.Among new derivatives of glucosamine, a series of importantcompounds has recently been synthesised by Weizmann andHopwood,g4 who have succeeded in preparing complexes containingglucosamine and aminoacyl residues. The method followed was tocondense glucosamine hydrochloride with a-bromoacyl haloids inthe presence of alkali, and to act on the products with cold aqueousammonia. The ultimate compounds obtained were anhydrides ofa-aminoacylglucosamines, and the development of the research willbe awaited with much interest.The formation of a series of glucosides derived from glucosaminehas also been described in the course of the year.95 By condensingbromotriacetylglucosamine with hydroxy-compounds, in the presenceof a base such as morphine, a series of acetylated aminoglucosideswere obtained, from which the acyl groups were removed by cautious93 J.C. Irvine and A. EIyiid, P., 1913, 29, 306.g4 Pror. liuy. Sue., 1913, A, 88, 455 ; A., i, 958.95 J. C. Irvine and A. Hynd, T., 1913, 103, 41ORGANIC CHEMISTRY.83hydrolysis. Amino-glucosides differ greatly in their behaviourtowards liydrochloric acid, in some cases hydrolysis proceedingnormally, and in others only with the utmost difficulty. For thisreason it is suggested that the two types are differently constituted,the stable forms being N-cyclic compounds, whilst the others areregarded as normal glucosides. a-Aminohelicin and a-aminosalicinare among the representatives of the latter class, and compounds ofthis type may possibly occur in nature.I n this connexion it may be noted that a new glucosaminederivative, termed Zycoperdin, has been isolated from the fungus,Lycoperdum gemmatum. This compound, to which the formulaC,,H,,OgN, has been ascribed, exists in two modifications, andalthough the linking of the two glucosamine residues present in themolecule has not been determined with certainty, the substancepossesses a special interest in view of its comparative simplicity.96Incidentally it may be pointed out that the occurrence of glucos-amine among plant products does not of necessity involve thepreexistence of glucoproteins, and an instructive paper byViehoever97 shows that chitin may be the original source of theamino-sugar.A t the same time the claim made in this paper thatbacteria, like certain fungi, contain chitin cannot be regarded asfinally established in view of the results of other workers.98Tannin.On the publication last year of two papers by Fischer andFreudenberg, it was evident that the chemistry of tannin hadentered on a new phase.99 The idea then put forward that tanninmay be regarded as essentially a pentadigalloylglucose has beensupported in a number of indirect ways during the current year,and has stimulated the synthesis of complex derivatives of glucosepossessing high molecular weights.The tannin problem, althoughfar from being solved, may a t least now be regarded as one whichcan reasonably be discussed under the general heading of carbo-hydrate derivatives, and for Some time to come, work in this fieldis likely to be extended by the synthetical methods usually employedin the sugar group.I f tannin is to be regarded as a substituted glucose, the opticalactivity of the complex becomes an important factor, and recentwork1 has gone to show that in determinations of the specific96 Y.Kotake and Y. Sera, Zeitsch. physiol. C/iem., 1913, 88, 56 ; A., i, 1212.97 Ber. Deut. bot. GES., 1912, 30, 443; A , , i, 142.98 ‘1’. Iioinienski, Biill. Acad. Sci. Cracozo, 1913, 10, A, 942 ; A., i, 428.99 Bey., 1912, 45, 915, 2709 ; A., 1912, i, 471, 887.1 E. Navassait, Zcituch. Chent. Imi. Kolloide, 1913, 12, 97 ; A . , i, 383.a 84 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.rotation of tannin the effect of the solvent and of variations inthe concentration are very great. The maximum activity isshown in aqueous solution, and the value increases greatly withdilution, ultimately reaching [a] 8 9 * 7 O for c =0*08. I n alcohol,on the other hand, the specific rotation is much lower, and thevariation with change of concentration is small.It is, of course,extremely doubtful if much trust can be placed in determinationsof the rotatory power of tannin in coiicentrated solution, but thefigures quoted by Navassart for low concentrations show a generalresemblance t o those previously determined by Fischer. On theother hand, the values disagree with those recorded for tanninisolated from Turkish galls.The observation 2 that glucogallic acid occurs associated withtannin is of evident importance, and the properties of the com-pound have now been further described. The acid is opticallyactive, and although it reduces Fehling’s solution i t apparentlypossesses the glucosidic structure, and is hydrolysed to give glucoseand gallic acid.As the compound is a comparatively simple sub-stance compared with tannin, the evidence of hydrolysis may beregarded as direct and convincing, pointing t o the fact that glucose,in combination with gallic acid, is naturally associated with tannin.Unfortunately, it has proved impossible to verify the nature ofFeist’s glucogallic acid by synthesis. Through the agency of aceto-bromoglucose, Fischer and Strauss 3 have prepared a P-glucosido-gallic acid, which has the normal structure:C,H,i0,~O*C6H2(OH)2*C02H.Although the compound shows many similarities with the ‘‘ gluco-galline ” described by Gilson; i t is certainly different from Feist’sproduct. This difference cannot be explained on the assumptionthat the latter is the 3-modification of the glucoside, and the twocompounds are probably fundamentally distinct, judging from theirbehaviour on hydrolysis.A definite step towards the synthesis of a penta-m-digalloyl-glucose has been made through the discovery of an improvedmethod for preparing m-digallic acid in quantity.5 The structureof the compound has been confirmed by methylation, and it wouldappear that it is identical with the digallic acid previouslydescribed as the para-compound.The synthesis of a penta-digalloylglucose has so far not been carried out, but in view ofthe successful preparation of the glucose derivatives containingI<. Feist, Arch. Pharm., 1912, 250, 668 ; A . , i, 70.Ber., 1912, 45, 3773 ; A . , i, 180.E. Fischer and I<. Freudenberg, Bcr., 1913, 46, 1116 ; A ., i, 4f9.* E. Gilson, C m p t . rend., 1903, 136, 386 ; A., 1903, i, 355ORGANIC CHEMISTRY. 85aromatic substituents of high molecular weight, which are describedin the paper referred to, there is every reason t o hope that thesynthesis of the essential constituent of tannin will not be longdelayed. A4ttertion should also be drawn to a summary of thepresent position of the chemistry of tannin which has been givenby Fischer in the form of an address.6 This development musthave the effect of directing attention to the fact that the sugarmolecule can function as a nucleus in the formation of hugemolecular complexes, in that there seems no practical limit t o themagnitude of the substituents which may replace the hydroxylgroups.Possibly also, in future work on the cleavage of naturalcompounds, there will be less tendency to disregard, as insignificantand unimportant, the small proportions of reducing sugars whichare frequently formed in such reactions.Emym e Synthesis.Any review dealing with the action of enzymes may readilyoverlap with other sections of the Annual Reports, and consequentlyreferences which may be suitably included under the chemistry ofaliphatic compounds must of necessity be brief, and can give onlya slender idea of the volume and importance of the work nowbeing carried out in this field. Generally speaking, the presenttendency of researches on enzyme action is to concentrate on twotypes of problem, namely, (1) synthetic reactions promoted byenzymes, and (2) the mechanism of fermentations.Regarding thelatter question, the original literature up to 1910 has been includedby Harden in his monograph on alcoholic fermentation, and itthus appears desirable, in the meantime, to limit the present reviewto noting the recent advances in enzyme synthesis.A useful summary of the work which has been carried out duringthe past three years on the synthesis of glucosides by means ofemulsin has been recently compiled by Bourquelot and Bridel,7 buti t invites the criticism that a growing tendency exists to publishresults in small, fragmentary sections, and in an incomplete state.The general principle underlying enzyme synthesis is that theequilibrium between a sugar and a glucoside, when in contactwith the appropriate enzyme, can be displaced in the directionof the glucoside when the solvent contains excess of the hydroxy-component of the glucoside.Most of the recent work has thusdealt with the action of enzymes on sugars dissolved in alcoholscontaining varying amounts of water, or in some cases acetone.E. Fischer, Ber., 1913, 46, 3253 ; A . , i, 1352.7 Ann. Chim. Phys., 1913, [viii], 28, 145; A., i, 78186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.When emulsin is employed, the P-form of the hexoside is produced,Band the following may be mentioned as typical examples ofB-compounds synthesised in this way : methylglucoside, benzyl-galactoside, geranylglucoside, and cinnamylglucoside. The di-saccharide gentiobiose has also been synthesised in a similar mannerfrom glucose.9 The compounds can apparently be isolated in a remark-ably pure condition, and in some cases have been obtained crystallinewhen ordinary synthetic methods give rise merely to amorphousproducts.Considerable attention has been given to proving thatthe same enzyme carries out both hydrolytic and synthetic actions.Thus, solutions of dextrose in dilute methyl alcohol, and ofP-methylglucoside in the same solvent, undergo oppositely directedactions under the influence of emulsin, the rates of hydrolysisand synthesis are the same, and the same equilibrium is reachedfrom both directions.*O A similar conclusion is arrived a t in thecase of P-ethylglucaside, and Bayliss, in a study of the systemglycerol, dextrose, glycerolglucoside and water, has obtained thesame result.11It is evident that the possibilities of enzyme synthesis are almostunlimited, and must have an important bearing in the future onthe chemistry of the natural fats and carbohydrates, but consider-able caution must still be exercised in drawing conclusions fromthe results, owing to the difficulty in obtaining individual enzymesor even standardised mixtures of enzymes.This applies withspecial force to emulsin, which has been shown by H. E. Armstrongand others12 to contain several closely-related enzymes, and aninstructive case which emphasises this point is quoted by Krieble,who found that an ern ulsin which synthesised Z-mandelonitriloproduced the d-isomeride two years later.13In addition to emulsin, the enzyme contained in the aqueousextract of bottom yeast has also been used in the synthesis ofglucosides, but in this case the a-forms are produced.As anecessary part of this line of investigation, a considerable amountof work has been done during the past year on the proportions of8 E. Bourquelot and H. Hdrissey, Compt. rend., 1912, 155, 1552 ; A., i, 213 ;J. Hamalainen, Bwchem. Zeitsch., 1913, 52, 409 ; A., i, 888 ; E. Bourquelot andM. Bridel, Compt. rend., 1913, 157, 72 ; A., i, 888 ; J. Pharm. Chim., 1913, [vii],8, 15 ; A., i, 1007.9 E. Bourquelot, H. HBiisseyand J. Coirre, Conzpt. rend., 1913, 157, 732 ; A., i,1305.lo E. Bourquelot and M. Bridel, loc. cit. ; E. Bourquelot and E. Verdon, Compt.rend., 1913, 156, 957 ; A., i, 542.l1 W.M. Bayliss, J. f’hyszol., 1913, 46, 236 ; A., i, 919.12 Proc. 809. SOC., 1912, B, 85, 359 ; A., 1912, i, 816.13 Biochem. B,ull., 1913, 2, 227 ; A., i, 663, 1255ORGANIC CHEBIISTILY. 87various alcohols which may be employed in enzyme actions withoutdestroying the activity of the catalyst, and in ascertaining thetemperature limits of these reactions.14It would be unfortunate if the success which has attendedresearches on enzyme synthesis had the effect of distracting attentionfrom the problems involved in the hydrolytic actions of enzymes.The two types of inquiry are naturally intimately connected, andthe time seems to have come when the synthetical researches shouldbe directed, not so much t o the multiplication of new examples,as t o systematic attempts to interpret the changes involved.Apaper by Prof. and Dr. Armstrong,l5 which contains a criticaldiscussion of their experimental work on the nature of enzymeaction, with particular reference to hydrolysis, has an importantbearing on the question of enzyme synthesis. Owing to the closely-sustained reasoning involved, it is impossible to refer t o the detailsof this important paper, but the original should be consulted byall who are attracted t o the subject of enzyme action generally.Celltilose.It is only nataral that a large proportion of the currentresearches on cellulose should have a direct technical bearing, andi t is a difficult matter to select, from the mass of somewhatempirical work, such investigations as are likely to lead t otheoretical developments.It can, however, still be said that thedifficulties of the problem do not prevent numerous workers fromendeavouring to gain some insight into the structure of the cellulosecomplex, and an important step has been made as the result ofindependent researches by Ost,l6 and by Willstiitter and Zech-meister.17 The latter observers have traced, polarimetrically andgravimetrically, the hydrolysis of cellulose when dissolved in con-centrated hydrochloric acid. Their results lead to the conclusionthat the dextrose formed amounts to 96 per cent. of the value calcu-lated on the assumption that cellulose is wholly composed of dex-trose residues. Jn a subsequent paper,lR Ost criticises the validity ofWillstatter’s method, and claims, with some justice, that the olderprocess, in which cellulose is first dissolved in sulphuric acid andthe hydrolysis completed in a highly diluted solution, is less openl4 E.Bourquelot mid M. Bridel, J. Pharm. Chim., 1913, [vii], 7, 27 ; A.,i, 212, 303, 428 ; F. Keeble, E. F. Armstrong, and W. N. Jones, PTOC. Roy. SOC.,1913, B, 86, 308 ; A . , i, 803.H. E. Armstrong and E. F. Armstrong, Proc. Roy. Soc., 1913, B, 86, 661 ;A . , i, 1116.16: H. Ost aud L. Wilkening, Chem. Zeit., 1910, 34, 461 ; A., 1910, i, 364.l7 Ber., 1913, 46, 2401 ; A., i, 955. l8 Ibid., 2995 ; A., i, 114888 APiNUAL REPOICIS ON THE PROURESS OF CHEhllSTRY.to objection. The results arrived a t by both workers are, however,practically identical so far as the dextrose content of cellulose isconcerned.Further confirmation of this important point has beengained by Ost in his study of the hydrolysis and acetolysis ofcellulose, in that he finds the combined yield of dextrose andcellobiose acetates agrees with the supposition that only dextroseresidues are present in cellul0se.~9The linking of the dextrose groups in cellulose is a problemwhich has aroused considerable discussion in the past, but directexperimental evidence bearing on the question is difficult to obtain.A recent paper20 indicates, however, a new line of attack. Themethod proposed is to methylate cellulose completely, and to subjectthe product to acid hydrolysis. A mixture of methylated dextrosesshould thus bs produced, and the determination of the number anddistribution of the alkyl groups in each sugar would then give adirect clue to the union of the monosaccharide residues in theparent complex.The research has meanwhile not proceeded farenough to show if the hopes of the workers will be fully realised,but the results are interesting. The alkylation, which was effectedby means of methyl sulphate, shows a distinct tendency t o bearrested a t the definite stages indicated in the formula=Ci,H,gOg*OMe and C6H,0,*OMe.It is perhaps significant that in the latter compound the cellulosederivative still retains the capacity to form a xanthate, and thatthe methyl group survives the reaction, and is present in the“ regenerated cellulose.”Despite numerous and laborious investigations, the nature ofthe derivatives of cellulose termed (‘ hydrocelluloses ” and ‘‘ oxy-celluloses ” still remains vague and uncertain. It may be noticed 21that Ost has abandoned his previous view that cellulose and hydro-cellulose differ in composition, and he now regards the latter asmerely possessing a smaller molecular magnitude.His conclusionshave, however, already been questioned. Similarly, the opinionhas again been put forward22 that a-oxycellulose differs fromcellulose, not in composition, but only in the nature of the fibrousstructure, and that 8-oxycellulose coiisists merely of degradationproducts. This state of confusion is perhaps not to be regretted, asattention must necessarily be directed to ascertaining the r81e ofsurface conditions in affecting reactions carried out on organisedstructures.I9 Aitnalen, 1913, 398, 313 ; A., i, 833.20 W.S. Denham and Miss H. Woodhonse, T., 1913, 103, 1735..LO& cit.0. Piest, Zceitsch. angezo. Chem., 1913, 26, 24 ; A., i, 250ORGANIC CHEMISTRY. 89It is a noteworthy fact that, outside of biochemical investigations,very few publications have recently dealt with the chemistry ofstarch or inulin. Further information as to the molecular com-plexity of starch has been gained by subjecting potato starch tothe action of enzymes, and precipitating the degradation productsa t definite intervals.% The approximate mean molecular weight,when determined by viscosity measurements, showed regularvariations in magnitude.I n amylodextrins the value was above10,000, decreasing in erythrodextrins to 6200-7000, and, ulti-mately, in achroodextrins to about 3700. Finally, it has beensliown,24 by direct measurement of osmotic pressures, that themolecular magnitude of dextrin-fl is approximately 950 & 50. Itwill be seen that this value, which agrees well with those obtainedby other processes, corresponds with a hexa-amylose. The simpleramyloses are substances of considerable interest, and a detailedaccount of their properties is contributed by Pringsheim and Eisslerin a recent paper.25Nitrogen Compounds : Theories of Structure.I n view of the fact that during the past two years severalimportant papers have appeared dealing with the theoreticalquestions presented by nitrogen compounds, it has been consideredadvisable t o place severe limitations on the number of referencesto investigations which are mainly of a descriptive or purelyexperimental nature.A problem of long standing, the distribution of the nitrogenvalencies, has once more been brought within the range of discussionas the result of the isolation of amino-oxides of the type a : Nbcdin optically active modifications.26 The assumption made byMeisenheimer that the five valencies are not inter-equivalent hasnow been subjected by him t o experiment, and, selecting trimethyl-amine oxide as a test substance, he has carried out the reactionsindicated below 27 :Rle,’N:O -+ RI Me,N<I OR -+ XaOH Me,N<OH ORHC1 Me,N:O -+ Me,N<;T 2’: Me3N’OH ‘01: *It.should be noted that the final products were not isolated in thepure condition, but their reactions in solution indicate that thesubstances are isomeric and not identical. Further, the isomerism23 W. Biltz, Ber., 1913, 46, 1532 : A., i, 707.W. Biltz and TIT. Truthe, ibid., 1377; A., i, 593.Ber., 1913, 46, 2959; A., i, 1156.J. Meisenheimer, Annalan, 1911, 385, 117 ; A . , 1912, i, 25.27 Ibid., 1913, 397, 273; A., i, 59590 ANNUAL REPOlI'l'S ON THE PROGRESS OF CHEMISTRY.OR has been shown t o extend to compounds of the type Me,N<Oll,and Me3N<oR , where again the decomposition reactions lead t othe conclusion that the alkyloxy-groups are attached t o the nitrogenatom in a different manner.Other structural representations may,however, account for the isomerism. For example, the formulaeOk'Me,N:O<iR and Me3N:O<g"', which are based on the oxoniuintype, would explain the existence of two forms, but these andother alternatives are rejected by Meisenheimer. He ultimatelycomes to the conclusion that in ammonium compounds nitrogen isdefinitely quinquevalent, and the units attached to four of theprincipal valencies occupy an inner zone, exterior to which is theatom or group attached t o the fifth principal valency. Further,he imagines the outer group t o have no fixed position, and, inconsequence, to have no influence on the asymmetry. Accordingto this view, the isomerides mentioned above could be representedby such formulae as [Me,N*OR]*OR/ and [Me,N*OR/]-OR, and thesuggestion is made that similar considerations may eyen be appliedt o phosphoiiium compounds.These ideas have not been allowed t o remain long unchallenged.28It has been pointed out that if isomeric compounds of the typeMe,N(OR)OH do exist, they may be regarded as alcohols-tes of afeeble base, Me,N(OH),, and, as such, would be hydrolyticallydissociated by water to give identical products.I n order toaccount for the existence of the second isomeride, Fromm isdisposed to regard the action of methyl iodide on trimethylamineoxide as resulting in the formation of an oxonium methiodide,which, on treatment with alkali, would be converted intoMe,N :O<oH. MeThe present position of the resulting argument is that, whilst theauthors concerned agree that in ammonium compounds there arefour negative valcncies and one positive valency, Fromm is unwillingt o admit that these considerations apply equally t o amino-oxides,which he regards as exercising negative and positive valencies in theproportion 3 : 2.Another ratio, that between speculation andexperiment, will be an important factor in determining the progresslikely to be made in this discussion.A result which has a direct bearing on the nature of the nitrogenvalencies was obtained in the course of a research on the resolutionof phenylmethylethylazonium iodide,29 as, during the preparationa E. Fronim, Annatm, 1913, 399, 366 ; A . , i, 1047.B. I<. Singh, T., 1913, 103, 604ORGANIC CHEMISTRY. 91of the compound, i t was found that the order in which the alkylgroups are introduced does not affect the constitution of theresulting product. This result is opposed to the idea originallyadvocated by LeBel, but is not inconsistent with Meisenheimer’slater views.Current ideas regarding the structure of aliphatic diazo-com-pounds have no doubt been greatly influenced by Thiele’s adherenceto the view that diazomethane and hydrazoic acid may be repre-sented by the formulze CH,:NiN and HN:NiN respectively.Freshexperimental evidence on this question is now available,30 as it hasbeen shown that the action of Grignard reagents on diazocamphorand diazodeoxybenzoin proceeds, in conformity with Thiele’s views,to give the substituted hydrazone corresponding with the parentdiketone :CfiH5*7N2 MgMeI CGH5*F: N NK*C H,C,H;CO - -f C,N,*COOn the other hand, the products to be expected if the nitrogenatoms are linked in a cyclic structure would be respectively:and the possibility still remains that a<zo-compounds of this typewould escape detection in view of their ready transformationinto the isomeric substituted hydrazones. Unfortunately, thereaction between diazodeoxybenzoin and magnesium phenylbromide, which might be expected to settle this point, followed anunexpectedly complex course.The results obtained in the investi-gation now referred to are cert’ainly direct and emphatic. I n theoriginal paper it is, however, pointed out that many reactions ofaliphatic diazo-compounds which may be claimed to support Thiele’sviews are equally well explained in terms of the older cyclicformulx.Thus, the preparation of diazomethane from hydrazinewas regarded by Staudinger and Kupfer 31 as involving the changesH,N*NH, + )C:N*NH, + H,C:NiN. It is, however, possiblethat the part played by chloroform in hhis reaction consists incondensation with an amino-group, followed by the elimination of athird molecule of hydrogen chloride :cl>C<g:+ H €T,N*NH, --+ g>C:N*NH, -+30 31. 0. Forster and D. Cardwell, T., 1913, 103, 861.31 H. Staudinger and 0. Iiupfer, Ber., 1912, 445, 501 ; A.,N -+ H,C<l I N ’1912, i, 24592 SNNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Any review of theoretical developments in the chemistry ofnitrogen compounds would be incomplete without reference toviews recently expressed as to the mechanism of the formation ofcarbamide from ammonium ~ y a n a t e .~ ~ I n last year's Report anaccount was given of Chattaway's theory of the change, and thishas now been criticised by K7erner, who offers an alternativeexplanation. It is maintained that the fundamental factorsgoverning the reaction are (a) dissociation of the ammonium salt,and ( b ) the establishment of equilibrium between the isomericforms of cyanic acid as expressed by the scheme:HO-CN Enol form -+H,N*O.CN ZZ NH, + + + HN : C/rH3 -+HN:CO Keto form -+ \O NH:c<E,H~ or NH,*CO*NH,.A number of arguments and experimental results are quoted insupport of the above view, and, more recently,33 a quantitativestudy of the formation of biuret has strengthened the argumentmaterially. It has been showii that the formation and decom-position of biuret may be regarded as a reversible reaction betweencarbamide and the "keto-form " of cyiinic acid :between 135-190" + --H ~ C O I above 190"HN :C*OHAHHN:&OHEnolic form-+B,N*COk HH , N ~ OKeto-form.I n the meantime i t wouid be premature to weigh the claims ofthe rival theories, and a critical comparison of their merits maythus be reserved.A miao-compoztnds.Although a large number of investigations have lately beenconcerned with amino-compounds, the main result has been thesimplification and extension of working methods rather than thedevelopment of any novel theoretical problems.As examples ofnew or improved practical processes likely to find useful application,reference may be made to the fact that the method of preparingsecondary amines from acids has now been applied with highlysatisfactory results to the production of disecondary amines fromdicarboxylic acids,34 and, in another useful paper, directions aregiven whereby the yields of alkylamines obtained from nitriles maybe greatly improved by simple modifications of Ladenburg's33 E. A. Werner, T., 1913, 103, 1010.33 lbid., 2275. 3J 11. It. Le Sueur, ibid., 1119ORGANIC CHEMISTRY. 93method.35 Workers who have occasion to study acid amides willalso welcome the observation that Hofmann’s method of preparingthese compounds can be adjusted to give good results,36 and mayfind it necessary to consult a paper on the application of Hofmann’sreaction to dialkylacetamides.37A suggestive paper by Meisenheimer offers a novel explanationto account for the formation of dialkylchloroamines by the actionof hypochlorous acid on tertiary amines.38 The idea is put forwardthat in the first stage of this reaction a trialkylamine dichloride isformed, and this in turn gives rise to an unsaturated derivative:I n the above example, the final reactions consist in the formationof formaldehyde and dimethylamine hydrochloride, which is thendecomposed by the excess of hypochlorous acid.The theory cer-tainly seems to be in good agreement with the experimental results,but it is very doubtful if it is consistent with the properties oftrialkylamine dihaloids, so far as these are known from the studyof trimethylamine dibromide.A mino-acids.-Attempts have frequently been made to isolatedefinite condensation products from the action of formaldehydeon amino-acids, but, as a rule, the methods employed have beensomewhat drastic, and although the products show many similaritieswith the polypeptides, their formation doubtless involves profoundmolecular changes.I n recent work, which has led to more definiteresults, it has been shown that under carefully regulated conditions,the action of formaldehyde on glycine is to give a stable methylene-diglycine, CH,(NH-CH,-CO,H),, and, further, that in the presenceof reducing agents the reaction gives rise to sarcosine and dimethyl-aminoacetic acid.39 This method of methylating amino-acidspossesses many practical advantages, and will doubtless find con-siderable application.A synthetic method of building up complexes containing amino-acyl residues depends on the fact that ethyl, chloroglyoxalate maybe condensed with esters of amino-acids in the form of their salts.The product can then be coupled with a different amino-acyl groupby condensation with the potassium salt of a second amino-acid.For example, ethyl chloroglyoxalate and methyl a-aminopropionatehydrochloride give, according to the firsbmentioned reaction, methylethyloxalyl-a-aminopropionatq, C0,Et-CO-NH*C’HMe*CO,Me, andN(CH,), -+ N(CH3),C1, -+ N(CH,),(:CH,)Cl.35 J.N. Rakshit, J. Amer. Chem. Soc., 1913, 35, 444; A . , i, 606.36 H. Decker, Annalen, 1913, 395, 282; A., i, 272.37 I?. L. Pyman, T., 1913, 103, 852.3s Ber., 1913, 46, 1148 ; A., i, 447.W. LBb, Biochem. Zeitsch., 1913, 51, 116 ; A., i, 70994 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.subsequent reaction with potassium aminoacetah gives methylglycineoxal yl-a-aminopropionate,CO,H*~,~NH*CO*CO*NH*CHMe*CO,Me,which serves as a type of a large number of compounds synthesisedby this method.40It is quite evident that the investigation of complex amino-acidsis in the meantime being prosecuted by biochemical rather than bysynthetical methods, and this state of affairs will no doubt continueuntil further study of the Walden inversion has removed therestrictions and uncertainties a t present attending the synthesis ofoptically active compounds.JAMES COLQUHOUN IRVINE.PART II.-HOMOCY CLI c DIVISION.The mass of literature which comes under review for the purposesof this section of the Annual Reports has shown no falling off, butrather an increase this year; the number of papers which had tobe considered amounted nearly to 400.Within the limits whichare imposed, it is impossible to deal with the great majority of theseresearches. In this particular region of the subject m y intelligibleaccount of much of this work demands no inconsiderable space.The writer is very conscious of the fact that he has omitted muchof importance in making his selection. Many of the researches aremainly extensions in detail; an unusual number of “ new ” com-pounds have been described. Others of more general interest areobviously of the nature of interim reports, and can in consequencebe more appropriately considered at a later time. The survey ofthe results of this huge chemical activity has impressed the presentwriter with the truth of the statement made by a former Presidentof the Society, that the great obstacle to advancement lies in thelack of co-ordination of this new knowledge ; to (( integrate ” thisinformation is the preesing task.The Structure of Benzene and Naphthaleme.After the vigorous discussions on the structure of the benzenenucleus, started partly by the discovery of cyclooctatetraene, whichwas a feature of 1912, this year’s literature contains but an after-math.This renewed examination of the problem left the“centric” formula, of all the hypo€heses, as the most suitablesymbol for representing the unique character of benzene. DuringD. J. Meyeringh, Eec. tmv. chim., 1913, 32, 140; A . , i, 834ORGANIC CHEMISTRY. 95the period under review the exact meaning of the singular absenceof free affinity in benzene, and hence the question of the representa-tion of the disposal of the residual affinity, have formed the subjectof a gentle exchange of opinlbn.1Much labour has been expended on a study of the absorptionspectra of benzene and its simpler substituted derivatives. Theabsorption of the vapour has been examined rather than that ofthe solutions, as generally, owing to the absence of the dampingeffect of the solvent, the detection of the delicacies of the selectiveabsorFtion becomes possible; and, further, there is no confusion,owing t o absorption by the medium, especially in the more refrang-ible region.2-4 very careful comparative study of the ultraviolet absorptionof benzene (as vapour) and of cyclohexene and A1 :3-cycZohexadienehas einphasised the peculiar relations of the six carbon atoms ofthe benzene nucleus.3 By means of it fluorspar spectrograph Starkobtained photographic records in regions beyond those reachedby previous investigators, in fact, as far as ~=185-180pp, andhas thus found indications of extreme ultraviolet absorption bands,even in saturated hydrocarbons, such as cydohexane and camphane,as well as in uusaturated compounds.cycZoHexene and cyclohexa-diene show the two unresolved broad bands in the ultravioletregion, in both cases similar to those characteristic of the ethylenelinking. The conjugation of the linkings in the latter causes ashifting of the, bands towards the visible spectrum, and at the sametime an intensification of the less refrangible band. Benzene givesa totally different spectrum from either of these hydrocarbons ;besides the known group of narrow bands, ~ = 2 7 0 - 230 ,up,* thereis an intense group of similar narrow bands a t ~ - 2 1 0 - 190 pp. Itis urged, therefore, that in benzene a specific relation exists betweenthe carbon atoms, which is quite distinct from the ordinaryethylene (or acetylene) linkings.The term " benzene-linking " issuggested--a relation perhaps best represented in our usualsymbols by the Armstrong centric formula.H. von Liebig, i3,d., 1913, [ii], 87, 393 ; A., i, 607.Piesideiitial Address to the Chemical Section of the British Association, 1913.1638.1913, 82, 665; A., ii, 363.45, 199; A . , ii, 367.367.A . , ii, 363, 365, 366.1907, A, 208, 475 ; A., 1908, ii, 243.K. Gebhaid, J. pr. Chem., 1912, [ii], 86, 540 ; 1913, [ii], 88, 94 ; A., i, 28, 841.Compare also W, P. Wynne,J. E Purvis axid N. P. McCleland, T., 1913, 103, 1088. J. E. Purvis, ibid.,H. S. Fry, Zeitsch. physikal. Chem.,N. A. Valiaschko, J. Rzus. Phys. Cheqn. SOC., 1913,G. Weimcr, Zeitsch. tuiss. Photochem., 1913, 12, 33 ; A ., ii,J. Stark and P. Levy, Jnhrb. Iiadioaktiv. Elektronik., 1913, 10, 139, 175, 179 ;W. N. IIartley, l'., 1881, 39, 153 ; 1885, 47, 685 ; 1887, 51,152 ; Phil. l'mns.,J. J. Fox and F. G. Pope, ibid., 126396 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The most recent consideration of the molecular refraction ofben~ene,~ on the other hand, appears to indicate conclusively thatthere are three ethylene linkings in the molecule of benzene. Itmay be argued, however, that the agreement between the calculatedand found values of the molecular refraction is purely accidental ;the unique (‘ benzene-linking ” may possess a refractivity whichproduces the same divergence as three normal (conjugated) ethylenelinkiags.The complete change in the spectra (vapour), which is broughtabout by the substitution of hydrogen by a hydroxyl or an amino-group: is a difficulty in the way of such a rigid association as Starksuggests, between the spectrum, more especially in the case ofbenzene, and a particular type of carbon-linking.Naphthalene.-The unexpected properties of cyclooctatetraeneled Willstatter and Waser 7 to decide in favour of Harries’ centric-ethylene formula for naphthalene in place of Bamberger’s sym-metric di-centric formula,8 which, it should be noted, does notcontain a benzene nucleus.This symbol was, however, put forwardwith the reservahion that no formula of the usual type completelyrepresented the whole chemistry of naphthalene.9 The high con-trast between naphthalene and dihydronaphthalene on hydrogena-tion has led to a reversal of this opinion; Willstatter now leans tothe di-centric formula.1° The grounds are that hl- and A2-dihydro-naphthalene yield tetrahydronaphthalene on reduction, in thisbehaviour resembling aromatic olefines, such a8 styrene and soforth. Naphthalene, on the other hand, yields only perhydro- andno tetrahydro-naphthalene, and in consequence cannot possess anynormal ethylene linking, rn Harries’ formula demands.Recent measurements of the absorption spectrum of naphthalenevapour favour the di-centric formula 11 ; the absorption spectrumshows two groups of narrow bands in the ultraviolet region, verysimilar to the bands given by benzene, but somewhat nearer thevisible spectrum.If Stark’s contention that the nature of thecarboti valence is the main factor in absorption be granted, it mustF.Eisenlohr, Jnhrb. Radionktiv. Elektronik, 1912, 9, 315 ; A , , 1912, ii, 709.Purvis, loc. cit. ; Fox and Pope, loc. cit.Ber., 1911, 44, 3423 ; A., 1912, i, 27 ; Ann. Report, 1912, 113.* J , pr. Chenz., 1890, [ii], 42, 194 : A., 1890, 1304.E. Bamberger, Bar., 1913, 46, 1899; A . , i, 846.lo Ber., 1913, 46, 1051; A., i, 455.l1 J. Stark and P. Levy, Jnhrb. Badionktiv. Eltktronik, 1913, 10, 179 ; A , ii,366. Compare W. pr’. Hartley, T., 1885, 47, 685ORGANIC CHEMlSTRY, 97be conceded that in naphthalene a linking closely resembling thebenzene linking is present.The strains or tensions in a series of six-membered conjugatedor condensed ring systems are greater when the rings are in linearorder than when the system is angular.12 The tensions indicatethat the system becomes labile in such a series of five rings.Thetheory was, failing simple carbon compounds, w'ell illustrated byderivatives of the azine and acridine series, in which linear systemsof five conjugated. rings are found. The recent preparation ofdi- and tetra-hydrodinaphthanthracene,affords an interesting illustration of the theory 13 in rings composedsolely of carbon atoms. Inasmuch as neither yields dinaphth-anthracene on oxidation, but its deco'mposition products, it may beconcluded that the linear hydrocarbon is highly unstable, and has,contrary to the statement in the literature, never been isolated.14Friedel an.d Crafts' Reaction.Notwithstanding the very extensive use of this reaction and thelarge number of most diverse applications to which aluminiumchloride may be put, until recently little has been done to elucidatethe manner in which this and similar catalysts act.Each yearadds, not merely to the list of syntheses, but also to the types ofreactions that can be brought about by its means. I n the periodunder review an interesting development is worthy of mention,namely, the elimination of hydrogen, especially from aromaticnuclei, accompanied by the formation of more complex compoundswith condensed nuclei.15 The reaction takes placemost easily in the case of ketones, when only a/\/\ /\ relatively low temperature ( 80-140°) is necessary.1 ( ), ,! Thus 1 : 9-benzanthrone (annexed formula) is\/ "f \( produced in excellent yield from phenyl a-naphthyl\/ ketone.I n a similar way a compound containingas many as ten condensed six-rings, 5 : 6 : 5' : 6I-di-benzpyranthrone (formula on p. 98), has been prepared. 3:8-a-col2 0. Hiusberg, Anizalen, 1901, 319, 281 ; A., 1902, i, 238 ; Ber., 1903, 36,4051 ; A., 1904, i, 200 ; J. pr. Cltem., 1913, [ii], 88, 58 ; A . , i, 849.lY W. H. and Mrs. M. Mills, T., 1912, 101, 2194.l4 F. Riissig, J . p r . C / m i . , 1900, [ii], 62, 30 ; A . , 1900, i, 601.l6 R. Scholl and C . Seer, Annnht, 1912, 394, 111 ; A., i , 56. Com:lare also R.Suholl aud others, Bet,., 1907, 40, 1691 ; 1910, 43, 1734, 2202 ; A . , 1907, i, 540 *1910, i, 494, 616.REP.-VOL.X. 98 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Naphthoylpyrene, which is itself obtained from pyrene anda-naphthoyl chloride in the presence /\ of aluminium chloride, is convertedinto the pyranthrone on heating with L2\,/?/2, l6 I I 3 the catalyst at 140O.Aluminium chloride has been occa-sionally observed to behave abnor-mally, and to bring about simultane-15 , I ously a side-reaction as well as theK’\(y;’\ normal condensation.16 Phthalic angive the corresponding chlorotolybbenzoic acids, but the two bromotoluenes yield one bromotolylabenzoic acid, which is probably the ortho-compound. Similarabnormalities have been found when the phthalic anhydride isreplaced by benzoyl chloride ; from the chlorotoluenes the expectedcondensed products are obtained, but the m- and pbromotoluenesgive mixtures owing to the migration of the halogen. I n the caseof o-bromotoluene the halogen is replaced by a liydroxyl group-a reaction not hitherto observed with aluminium chloride-andphenyl hydroxytolyl ketone is the sole product.The Mechanism of Friedel and Crafts’ Renetion.-It is a well-known fact that the quantity of aluminium chloride required tobring about condensations of acid chlorides and anhydrides withhydrocarbons varies very greatly with the constitution of the react-ing substances. I n some cases traces are sufficient, whilst in othersa molecular proportion or more of the catalyst is necessary inorder to obtain a good yield, This behaviour is not analogous tothe ordinary effect of variation in the concentration of a catalyst,for it appears that a certain minimum quantity of the chloridemust be present in the system in order that a reaction shouldfollow. Similar observations have also been made with othermetallic chlorides.The isolation of additive compounds of aluminium chloride andacid chlorides, in the first instance by G.Perrier,l7 led to thegeneral belief tlhat the formation of such additive compounds wasa necessary step in the Friedel and Crafts’ and analogous reactions.The halogen compound (or the acid anhydride) is supposed tobecome active in this additive compound, and hence able tol6 G. Heller and others, Rer., 1908, 41, 3627 ; A., 1908, i, 994 ; ibid., 1910, 43,2890 ; A., 1910, i, 770; ibid., 1912, 45, 665, 792; A., 1912, i, 357, 358; ibid.,1913, 46.1497 ; A . , i, 631.l7 Conzpt. rend., 1896, 122, 195 ; A . , 1896, i, 353; Ber., 1900, 33, 815; A.,1900, i, 331. B. N. Menschutkin, J. Rum. Phys. Chent. Soe., 1910, 42, 1310 ; A . ,1911, i, 45.V\/\<,’\I l l w\/)/\6’1(, I hydride and o- and p-chlorotoluenORGANIC CHEMISTRY. 99condense with the hydrocarbon. I n recent years the knowledgeof such co-ordinative compounds, in which the two units areattached by their residual affinity, has been greatly increased(Menschutkin, Pfeiffer and others); and the newer views onvalency have given an easy means of representing them by theuse of subsidiary linkings. The most diverse types of carbon com-pounds have been found to unite with many metallic chlorides,conspicuousIy those of iron, aluminium, tin, and antimony ; thecompounds even of benzene and other inactive hydrocarbons havebeen prepared.18 There may be some evidence in a few cases thatthese co-ordinative compounds are more reactive than the simpleorganic substance, but generally it seems t o be taken for granted,sometimes on the ground that these compounds are more “ unsatur-ated.” 19It is of interest to draw attention to the somewhat similar ideaswhich have been advanced to explain the mechanism of catalysisin organic reactions in ionising media. The reactive unit in thechemical change was taken to be a complex ion which the organiccompound formed with an ion, generally the hydrogen or hydroxylion, of the catalyst (Lapworth, Bredig 20) ; this additive compoundis obviously analogous to the co-ordinative compounds, with whichthey may well be classed.I n order t,o account for the abnormali-ties induced by t h s presence of salts, called the “neutral salteffect ” by Arrhenius, in such reactions as are catalytically acceler-ated by acids and bases, the suggestion has been made that thenon-ionised catalyst or the salt also forms a chemically activeadditive compound with one of the organic reactants; again thisbelongs t o the more usual type of co-ordinative compound. Thishypothesia, which has lately been vehemently advocated,”] isclaimed as giving values for the velocity-coefficients of such reac-tions more closely in accord with the experimental numbers thanthe theory that the hydrogen and hydroxyl ions are the sole agentsin the catalysis.More fundamental and certainly as promising isLapworth’s22 attempt to attack the problem of this type of catalysisby an investigation of the thermodynamic potential of such acatalyst as hydrogen chloride in alcoholic and aqueous alcoholicmedia ; i;he hitherto inexplicable variation of the activity of thisB. N. Menschutkin, J. Kuss. Phys. Chem. Sue., 1909, 41, 1089; A . , 1909, i,897; Chem. Zmtr., 1910, ii, 378, 379; A . , 1911, i, 273; J. Chzkn. Phys., 1911,9, 314 ; A . , 1911, i, 532 ; J . Russ. Pliys. CJLcm. SOL, 1911, 43, 1329 ; 1912, 44,1113 ; A., 1912, i, 100 ; ii, 922.l 9 Among others, P. Pfeiffer, Annalen, 1911, 383, 92 ; A, 1911, i, 788.2o T., 1901, 79, 1269 ; Zcitsch.Ebktrochem., 1903, 9, 118.S. F. Acree, Anzer. Chem. J., 1913, 49, 345; A., ii, 576.22 W. J. Jones, A. Lapworth, and H. M. Lingford, Y’., 1913, 108, 252.H 100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.catalyst in a variety of reactions, when, for example, a smallquantity proportion of water is added to an alcoholic medium, nowbecomes intelligible.I n the particular case of Friedel and Crafts’ reaction it isdifficult to harmonise the known facts with the hypothesis whichgives to an intermediary co-ordinative compound the most impor-tant r61e in the condensation.23 Apart from the great difference inthe quantity of the catalyst demanded in different reactions, thereis no relation between the vigour with which various chloridesreact with hydrocarbons and their tendency t o combine withaluminium chloride ; some of the most reactive chlorides (carbontetrachloride and chloroform) do not unite with the catalyst.Many acid chlorides, on the other hand, decompose easily uuderthe influence of aluminium chloride ; this sensitiveness is alsoapparently unconnected with the formation of additive compounds.The decomposition has been mainly studied in halogenated acidchlorides; the varying and sometimes devious course of the changeis most readily understood on the supposition that a chlorine atombecomes loosened or detached. Occasionally the element is elimin-ated as free chlorine, or hydrogen and chlorine are simultaneouslydetached from adjacent carbon atoms.Researches on the dynamics of Friedel and Crafts’ and analogousreactions have not been particularly successful in elucidating thepart played by the catalyst. The difficulties of accurate measure-ment are considerable.Using stannic chloride or ferric chloride,it was found that in the chlorination of benzene the speed wasproportional to the concentration of the catalyst 24 ; the chlorina-tion of nitrobenzene and the benzylation of anisole in the presenceof stannic chloride or aluminium chloride showed a similar rela-tion.25 A study of the interaction of pbromobenzenesulphonylchloride and benzene (and its derivatives) in the presence ofaluminium chloride has, however, given more enlightening results.26These appear to show conclusively that this acid chloride at leastis reactive only in so far as it is combined with the aluminiumchloride; excess of acid chloride does not indeed enter into reaction.The accelerating effect of the aluminium chloride is, moreover,partly paralysed by excess of the product, the sulphone; hence it* ‘J.Bijeseken and others, Proc. K. Aknd. Welmsch. Amsterdam, 1909, 12, 417 ;ibid., 1911, 13, 685 ; A., 1910, i, 152 ; 1911, i, 173 ; Rec. truv. chi‘n~ , 1913, 32,1 ; A., i; 334.84 A. Slator, T., 1913, 83, 729.25 H. Goldschmidt and H. Larsen, Zeitsch. physikal. Chew., 1904, 48, 424 ; A . ,26 S. C. J. Olivier arld J. Biiesekeu, Proc. K. Akad. Wetc7m71. Amstcrclam,1904, ii, 609.1913, 15, 1069 ; A., ii, 575.B. D. Stgelp, T., 1903, 83, 1470ORGIANIC CHEMISTHY. 301may be concluded that the sulphone also combines with thecatalyst.Notwithstanding the withdrawal of the aluminiumchloride by union with these compounds, its general catalytic effectis but partly destroyed, for the speed of the reaction remainsproportional to its total concentration. The free and not thecombined aluminium chloride has, however, the most powerfulaction, as excess of aluminium chloride over the acid chlorideeffects a relatively very great acceleration of the condensation.The reaction cannot therefore be put down merely to the unionof the catalyst with one of the reactants. It seems probable thatthis action is mainly exerted on the benzene; possibly it may beassumed that the catalyst acts by disturbing (“ dislocating ”) thebenzene molecule, so that the residual affinity becomes localised onona or more of the carbon atoms, either by forming a co-ordinativecompound or by some more subtle influence falling short of aco-ordinative union.It is noteworthy that toluene, where theresidual affinity would be leas evenly distributed, reacts far morerapidly with the sulphonyl chloride than benzene.The reaction may be represented as consisting of the followingsteps :C,H,Br*SO,Cl,AlCl, + C,H, = ( 1). C,H,Br*SO,CI,AlCI,,C,H,= (11). C,H4Br.S0,*C,H,,AlC13 + HCl.Since the speed is proportional to the concentration of thealuminium chloride, it follows that reaction I is the slower changewhich is measured, whilst reaction I1 h a a relatively high velocity,and hence is not measured.That the possession of residual affinity-an idea by no means of recent date27-confers the power to formco-ordinative compounds, and is closely associated with the catalyticsctivity of the aluminium chloride, can scarcely be doubted. Thisdoes not imply, however, that these additive compounds are thenecessary intermediaries ; their formation, in fact, involves a fallin potential, and hence a decrease in reactivity. The experimentalevidence favours rather the view that the free aluminium chlorideexerts some specific catalytic influence on the reactants. It is justwhen aluminium chloride forms a stable compound with one ofthese reactants that it is least effective, and hence a larger propor-tion is required to bring about a rapid reaction.Keto-enol Isomerism.The rapid advance in the knowledge of keto-enol isomerism justi-fies a recent attempt28 to revise the meaning of the various termsin common use.“Tautomerism” is to be used to include allReactivity of Tautomeric Compounds.H. E. Armstrong, Proc. Boy. ,Sot., 1P86, 40, 285.K. €3. Meyrr, Annalen, 1913, 398, 49 ; A , , i, 704102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.compounds, which yield two series of substancm derivable fromtwo isomeric formulae, when these formulae differ only in the positionof a hydrogen atom and of one or more ethylenic linkings. Tauto-merism includes : (1) ‘‘De~motropy,~’ when the two unsubstitutedisomerides can be shown to exist, for example, ethyl acetoacetate,o-nitrotoluens, dianthronedi-imine ; (2) (‘ Pseudomerism,” when onlyone form exists, the constitution of which can be exactly fixed.This‘( pseudomeride ” can yield derivatives of the same constitution, orof the constitution of the isomeric ‘ I pseudo-form.” Examples areanilines, phenols, oxymethylene compounds, and acid amides ;(3) Cryptomerism ” denotes a tautomeric substance, existing onlyin one form, the constitution of which cannot be fixed withcertainty. Examples are prussic acid, sulphurous acid, benzo-quinoneoxime, sulphinic acids, and so forth.Reactivity of Substances showi~ag Keto-enol Tmctomerism.-Although the reactivity of compounds showing this type of tauto-merism is perhaps now more generally ascribed to the enolic formof the compound, since Lapworth’s discovery of the mechanism ofthe bromination of acetone,Zg which has been so ingeniously utilisedby Meyer as a test, the logical consequences of such view in itsapplication to a number of organic reactions have not yet beenaccepted or even realised.The “ addition-theory ” of substitutiongenerally, which owes much of its definiteness to A. Michael 30 andJ. U. Nef,31 finds far more adherents than the “substitution-theory,” especially as i t seems so particularly applicable to theWalden inversion, but evidence is nevertheless forthcoming thateven in ketones direct substitution may take place. The opticallyactive o-carboxy-2-benzyl-l-hydrindone yields the brominatedketonic acid,CO,H*C,H,* C H, C Br<zf2>C,H4.The enolic form of the hydrindone,contains no asymmetric carbon; hence if bromine only reacts withthat, the product should be optically inactive.As a matter offact, some 5-10 per cent. of the active compound is produced,mixed with much of the inactive. Obviously if the speed of enolisa,tion were great, no active compound would appear, but the result29 Ann. RPport, 1911, 101 ; ibid., 1912, 125.30 J. pr. Chcm., 1888, [ii], 37, 487 ; A . , 1588, 1054.31 J. Anzer. Chenz. Soc., 1904, 26, 1566 ; A . , 1905, i, 109. For R discussion ofmodern views on Substitution, cowpare W. P. Wynlie, Pre Adential address to theChemical Section of the British Association, 1913ORGANIC CHEMISTRY. 103shows that bromination of ketones does not necessarily involve theintermediate formation of sn0l.32A consideration of the most varied reactions of compoundscapable of keto-enolic tautomerism 33 leaves little doubt that ingeneral it is the enolic form that reacts.Even in the ketonicdecomposition of &ketonic esters,34 which has now been found totake place quantitatively by simply heating with water at ZOOo,the speed of the reaction runs parallel with the readiness of enolisa-tion, and becomes very slow in ketonic esters of the type:CH,* CO*C;RR’-CO,Et.A comparison of the reactivity of enols and enolic ethers, and inparticular of phenols and phenolic ethers, goes far in answeringthe question as to the cause of the peculiar reactivity of the enolicgr0up.~5 The familiar theory which has again been recently advo-cated by 0. Himberg36 selects the ionisation of the movablehydrogen atom as the essential fact.It is now found, however,that. the enolic ethers, >C:C-OEt, are no less reactive than theenols; the esseiitial feature is not the movable hydrogen, but theassociation of the oxygen atom with the ethylene linking, whichgives rise to an “active double-linking,” as the authors name it.As tests of reactivity the rates of reaction with alcoholic bromine,nitrous acid, diazo-solutions, and with aldehydes have been choe.en.A comparison between the speeds of reaction of cinnamic acid andbenzoylacetic acid (hydroxycinnamic acid), to choose a goodexample, illustrates well the enormous influence of the enolicgrouping as contrasted with ordinary ethylenic linking. When thehydrogen is replaced by the ethyl group, as in ethoxycinnamicacid, there is no lessening of the speeds of reaction.The reactivityof the phenols is, of course, common knowledge, and is now shownto be comparable only to that of enolides, but it is not so wellknown that the phenol ethers are no less reactive. The authorsemphasise the deduction that the phenols react as hydroxy-com-pounds, and not as ketonic pseuda-forms, as Thiele37 and othershave suggested. Moreover, in the analogous cases of anthranol andanthrone,% and of 9-phenyl-anthranol and -anthrone,sg which arerespectively desmotropes, the enolic form is alone reactive.32 €3. Leuchs, Ber., 1913, 46, 2435 ; A., i, 974.Y3 K. H. Meyer, h e . eil.34 H. Mecrwein, Annalen, 1913, 398, 242; A ., i, 858.35 K, H. Meyer and 5. Lenhardt, itid., 66 ; A . , i, 723.a J. pr. Chem., 1911, [ii], 84, 169 ; A., 1911, ii, 873.37 Annalen, 1899, 306, 122 ; A . , 1899, i, 873.38 K. H. Meyer, ibid., 1911, 379, 42 ; A . , 1911, i, 193.39 K. H. Meycr and A. Sander, ibid., 1913, 396, 133 ; A., i, 489104 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n the coupling with diazo-solutions there is but little difference - -HO OH in reactivity between the phenols and their ethers.The reaction is represented as primarily a simple \ /addition (annexed formula), and on no groundrequires the necessaxy formation of an inter-mediary oxygen-ether, Ar*N:N*O*Ar’, examplesof which have been recently i~olated.~OI n connexion with the reactivity of keto-enoltautoinerides, reference should be made to the commonly supposedrelation between the intensity of the selective ultraviolet absorp-tion and the reactivity of the keto-enol form.The peculiarityof the absorption of enolides has recently been httributed byHantzsch41 to a static cyclic structure, rather than to a dynamiccondition, and has found confirmation in some highly exact spectro-scopic work.42 Moreover, from a particularly searching experi-mental criticism t o which this relation of absorption and reactivityhas recently been submitted, it would appear not to be based on acorrect interpretation of the known facts.43That the “ active double linking ” is produced by the neighbour-hood of the groups NH,, NHR, and NR,, as well ae of oxygen,can be easny demonstrated in the pyrroles and indoles.Theassumption that the reactivity of (“ cryptomeric ”) pyrrole isiiI I\//\N:NArassociated with the tautomeric form, N< CH:(?H , which possesses CII-CH,a so-called ‘‘ reactive methylene-group,” is not justified, inasmuchas N-ethylpyrrole, which can only exist in one form, is equallyreactive; from analogy to the enolides it seems certain that theimino-form is the more reactive. The isolation for the first timeof a desmotropic pair containing respectively an amino- and animino-group is of particular interest in this connexion. The yellow,fluorescent diaminodianthryl,NH,*Cand the colourless, no,n-fluorescent dianthronedi-imine,44are analogous to the desmotropy of dianthrone and dianthranol, orto the as yet unknown desmo,tropy of aniline and its imino-form.0.Dimroth and M. Hartmann, Ber., 1908, 41, 4012; A . , 1909, i, 66.41 Ann. Rcport, 1912, 119, 123.42 P. J. Rrannigan, A, K. Macbeth and A. W. Stewait, T., 1913, 103, 406.i13 H. M. Dawson, ibid., 1308.44 K. H. Meyer and H. Schlosser, Ber., 1913, 46,29; A . , i, 295ORGANIC CHEMlSTKY. 105As a test of the constitution of enolides, ozone has recently beenrecommended, as it does notl bring about a change of constitu-tion 45; by this means it is indicated that the enolide of benzoyl-acetone has the formula OH-CPh:CH*COMe,46 since the ozonideyields on treatment with water, benzoic acid and methylglyoxal,and that of ethyl benzoylacetate in chloroform, mainly the consti-tution OH*CPh:C(COMe)*CO,Et.Niiro-compounds and the Quinofioid Structzlre.Many attempts have been made in recent years, mainly byspectroscopic methods, to elucidate the exact constitution and toinvestigate tJhe chromoisomerism of the nitroanilines.47 I n a verythoroLgh discussion of the results, Hantzsch 48 concludes that thenitroanilines have not a quinonoid, as others had previously sug-gested, but a benzenoid structure, and, further, that the peculiari-ties of absorption and the chromoisomerism (or homochromo-isomerism, when there is no difference in spectral characters) are tobe attributed to the relations of one or more of the nitro-groupswith the amino-group; this relation is exprewed by a subsidiaryvalence :Attempts to obtain chemical evidence have recently been made.49The mere fact that o- and pnitroa.nilines dissolved in alcoholicalkali with a marked development of colour is evidence a t leastof some change, probably a quinonoid arrangement, in the salts, aview which has been generally accepted in the case of o- andp-nitrophenois.50 The isolation of the potassium and sodium saltsof a number of o- and pnitroanilines gives point to this view;these salts, which are highly coloured and often exhibit chromeisomerism, in marked contrast to other similar salts, do not containthe elements of ethyl alcoho1.5145 J.Scheiber and P. Herold, Ber., 1913, 416, 1105 ; A., i, 490.46 Compare I. Smedley, T., 1910, 97, 1486.47 E. C. C. Baly, A. W. Stewartand W. H. Edwards, ibid., 1906, 89, 514; E.C.C. Baly, W. B. Tuck and E. 0. Marsden, ibid., 1910, 97, 5 8 0 ; G. T. Morgan andA. Clayton, ibid., 1911, 99, 1945; G. T. Morgan, E. Jobling and R. T. F.Rarnett, ibid., 1912, 101, 1209.4* Ber., 1910, 43, 1651, 1662; A . , 1910, i, 474, 475.49 A. G. Green and F. M. Rowe, T., 1912, 101, 2453; 1913, 103, 508.5o 1%. E. Armstrong, P., 1888, 4, 27.5l For example:-M. Busch and M. liiigel, Ber., 1910, 48, 1549; A . , 1910, i,4 72106 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Recent spectroscopic work jg on nitro-compounds and the nitro-phenols might, however, suggest that these salts belong tothe cyclic ‘‘ conjugated ” mi-nitro-type, with or without a quinonoidstructure :The spectroscopic evidence seems now fairly complete, a t leastfor a change in the nitro-group and its relations in salt formation,if not as fully for a conversion of the benzenoid into the quinonoidconfiguration of the nucleus.53 Moreover, the arguments in favourof a quinonoid structure gain considerably in force from t.herecent demonstration that the particular spectroscopic and colourchanges occur only in the case of compounds where a quinonoidrearrangement is possible.54 Nevertheless, the chemical evidencein favour of a quinonoid structure is extremely meagre, ifnot wanting.I n recent literature there is much to suggestthat the truism that the constitution can only be finally deter-mined by chemical evidence, has been partly forgotten ; spectro-scopic land physical data in general point out analogies, andcheck the dsductions from chemical investigations.The study ofthe reactions of salts of nitrophenols by Hewitt and his collabora-tors55 is from this aspect very much to the point; the reactionsof the group *ONa in compounds of the type of sodium phenoxidehave been shown to be wanting, and ths reactions of the nitro-group to be modified, in the salts of nitrophenols. Hence it may beconcluded that these salts contain neither the group iC*ONa northe group iONO,, but are derivativw of quinone-nitronic acids,to use Bamberger’s apt name. The reactions chosen as tests werethe condensation with ethyl chloroacetate, and the reduction toazoxy-compounds by sodium methoxide solution. The salts of0- and p-nitrophenols gave no response to either of these reagents,and in this respect stood apart from all the other phenolsexamiped.As an example of a spectroscopic investigation which has givenexceptionally sure indications of the constitution of nitrophenols,the study of the absorption spectra of the derivatives of nitro-aminophenols in neutral, acid, and alkaline solution is quite note-worthy.56 The absorption under different conditions is sharplydifferentiated. I n acid solution the absorption spectrum, for62 A.Hantzsch and K. Voigt, Eer., 1912, 45, 85 ; A . , 1912, i, 151 ; comparealsoG. T. Morgail and J. Reilly, T., 1913, 103, 1494.53 Ann. Report, 1912, 118, 119, 120.54 J. T. Hewitt and others, T., 1912, 101, 1770.65 J. T. Hewitt, Misq R. M. Johnson and F.G. Pope, ibid., 1913, 103, 1626.56 R. Meldola and J. T. Hewitt, ibid., 876ORGANIC CHEMISTRY. 107example, of picramic acid, very closely resembles that of 2:4-di-nitrophenol; on addition of alkali this spectrum changes to the“ alkaline ” type when the concentration of the hydrogen ions hasdropped to 10-2-10-3. I n neutral solution the curve more closelyresembles the alkaline than the acid type. The structures in thevarious media a m supposed to be as follows:OH O HAcid.0 0I I I I#O,Na N0,NaAlkaline.,0I I0-NONcn t ral.Tho absorption spectra have also been used to elucidate thenature of the peculiar isomerism of o-dinitrobenzidine 57 ; it isdeduced that the isomerism is to be attributed to both nuclei inone compound being quinonoid, whilst in the other one only hasthis structure.iMe t a puinonoids.Chemists seem less shy of using formulze with a metaquinonoidlinking than formerly, although the existence of undoubtedexamples of this type is by no means certain.Perhaps at the.present time the salts of m-nitrophenol would not be claimed asmetaquinonoid,68 whilst in other cases, for example, the so-calledtribromoresoquinone,59 the constitution was incorrectly assigned.6OThe yellow hydrocarbon, tetraphenyl-m-xylylene:l C,H,< I CPb,’which seems to be an undoubted m-quinonoid, has been preparedfrom methyl isophthalate in exactly the same manner as theisomeric yellow pcompound was obtained from the terephthalate.02The absence of reaction with oxygen, and the inability to formadditive compounds with ether, alcohol, and 60 forth, is taken toexclude the possibility of its being a triarylmethyl compound.CPh,Chromoisomerism of Helianthine and Aminoazobenzenes.A very interesting and illuminating example of the application ofthe freer ideas on valency, and of the delicate analysis by means of the57 Ann.Report, 1912, 120 ; J. C. Cain, A. K. Macletli and A. R. Stewait, T.,1913, 103, 586.58 A. Hautzsch, Ber., 1907, 40, 339; A., 1907, i, 207.59 C. Liebermann and E. Dittler, Annalen, 1873, 169, 252 ; A., 1874, 62.80 R. Mejer aud I<. Desamari, Ber., 1908, 41, 2437 ; A., 1908, i, 658 ; ibid.,1909, 42, 2814 ; A., 1909, i, 241, 657 ; ibid., 1913, 46, 1220 ; A., i, 493.0. Stark and 0. Garben, ibid., 1913, 46, 659, 2252; A ., i, 361, 849.62 J. Thiele, abid., 1904, 37, 1463 ; A . , 1904, i, 491108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.spectroscope, is to be found in Hantzsch’s63 study of the isomerismof methyl-orange (helianthine) and other aminoazobenzenes. It isnow established that the solid, red helianthines, which can beisolated as mono- an‘d di-alkylanilineazobenzenesulphonic acids, aredissolved by all indifferent media, and by alkalis as yellowhelianthines, which have been isolated in the case of anilineazo-benzenesulphonic acid. Th0 (( red ” solutions are produced onlyin the presence of hydrogen ions, whilst the “yellow” appearalways when this ion is absent, and not only when hydroxyl ionsare present. Th0 red salts have, without doubt, a quinonoidstructure ; spectroscopically they resemble very closely the rosanilinedyes in possessing the characteristic ‘( quinonoid colour-band.” Thealkyl halogen derivatives of aminoazobenzenes,Ar*N:N*C“,H,*NR,,CH,X,resemEle spectroscopically azobenzene, and are undoubtedlybenzenoid compounds; they may be termed ‘‘ azonoid ” salts.Theyellow acid salts of dialkylaminoazobenzenes,Ar-N,*C,H,*NR,,HX-in the case of helianthine, the internal sulphonate-which aregenerally unstable, are spectroscopically quite different from thisclass, and resemble closely the red salts and rosanilines; hence theyare not ‘‘ azonoid ” salts, as was formerly stated.64The suggestion that these salts are quinonoiid by virtue ofauxiliary valencies, that is, are ‘‘ hemi-quinonoid,” is negatived onaccount of the fact that the close spectroscopic resemblance to thered salts does not justify so great a constitutional difference.Hencei t is concluded that the acid salts are also (‘holoquinonoid,” andthat chromoisomerism is to be attributed to valence-isomerism(2 and 3). A further consequence of this view is that free amino-and dialkylamino-azobenzenes. which show the quinonoid colour-band, must also be quinonoid in structure. Salt formation, then,is represented thus:On the same grounds, yellow helianthines and alkaline solutions(methyl-orange) are also given a holoqu‘inonoid structure (I).The colour change of the indicator can therefore no longer berepresented as the simple reversible transformation : azonoid saltT--* quinonoid 65 salt, but is replaced by the following scheme :6s Rer., 1913, 46, 1537; A, j, 775.61 A.Hnntzsch, ibid., 1908, 41, 1172 ; A . , 1908, j , 469.85 J. T. Hewitt, Analyst, 1908, 33, 85 ; A., 1908, ii, 269 ; T., 1909, 95, 1292,A. Haittzsch, loc. cit. ; H. T. Timrd, T., 1910, 97, 2477ORGANIC CHEMISTRY. 109C,H4--N*N:C6H,: Y’CH, C: H *NH*N:C6H4~N(CH,~,I YO,H(Na) I I --- CH3 SO3 l 6 I(1) Yellow. (3) Red. 3. C H *NH*N:CGH,xN(CH3),J. I / z II01l6C H *NH*N:C6tI,:N*CH3iSO,H(4) Red.CH3 so,---- l6(2) Yellow.It will be noted that the quinquevalence of nitrogen inammonium salts is given up in these formulze for Werner’s concep-tion of a tervalent; nitrogen linked to the acid by auxiliaryvaleme.This ingenious, if complicated, theory may perhaps express thefacts wore fully than t’he simpler ideas which it replaces, but itcertainly does not seem to make plain why hydrogen ions convertthe yellow solution of methyl-orange into the red.Some Researches on Colovring Matters.The knowledge of the relation of the colour to constitution insome aromatic colouring matters has been considerably extendedby some recent researches.66 Piccard’s examination of a numberof meri-quiaonoid salts derived from N-methyl- and N-phenyl-substituted pphenylenediamines and benzidines has led to theconclusion that Nietzki’s well-known rule must be modified. Onincrease of the magnitude of the molecule, the colour of a dye,according to Nietzki, passes up the spectrum, but,, it has since beenshown, at a certain point in the series of compounds returns againnearer to the red end.Since this behaviour has an analogy tothe interference bands, in the colour of thin plates, and such-like,this second series is called the “absorption colours of the secondorder.’’ Spectroscopic study indicates that the colours of thesecond order are distinguished by absorption in the red or ultra-red,as well as in the blue end of the spectrum. A colour of the secondorder is defined as that of a substance belonging t o a homologousseries of coloured compounds, the lower members of which havealready passed through the usual colour series.Very good examples of this phenomena axe found in the meri-quinonoid salts obtained by oxidation of alkylated pphenylene-diamines.The term meri-quinonoid is used for the intensely-coloured compounds of a quinone-hydrone type, which are com-pletely stable towards water and alcohol, but cleft into their66 .J. Piccard, Bcr., 1913. 46, 7843, 1860 : A . , i, 895, 896 ; F. Straua and A.Zeiine, ibici? , 1911, 46, 2267 ; A . , i, 992 ; E. R. Watson, P., 1913, 29, 348110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.components by acids; to them is assigned formulz in which thebenzenoid and quinonoid parts of the molecule are connected bysubsidiary valence definit.ely placed between the nitrogenT--e holo-quinonoid or the ordinary quinone-imonium salts possessone or more quinonoid nuclei, and are colourless or only feeblycoloured. mera’-Quinonedi-imonium bromide is yellow ; successivesubstitution of the hydrogen atoms of the amino-group by methylor phenyl groups causes a change of colour finally to blue in thediphenyl derivative ; the colour of the tetraphenyl-meri-quinonoidsalt is, however, green, and is therefore a colour of the secondorder.The meri-quinonoid derivatives from benzidine show thisgradation even better ; the unsubstitr.ted compound is blue, whilstthe tetraphenyl derivative is yellow of the “second order.” I nthe di- and tri-phenylmethane series, numerous examples can befound; for instance, a series of blue and green dyes are derivedfrom the salts of the benzhydrol, Nhle,*C,H4=CH:CGH4:NMe,C1, byreplacement of the hydrogen of the central methane group by alkyland other groups; but in auramine,NMe2*CGH4-C ( NH2) :C,H4:NMe2Cl,an auxochromic amino-group replaces the chromophoric alkylgroups, and hence its yellow colour is of the second order.Thissuggestion is strengthened by the fact that reduction of the auxo-chromic action of the amino-group by acetylation is followed by achange of colour from yellow to blue of the “first order.” Manyanomalous relittiom in the colour of the diamino- and triamino-triphenylmethane series can be accounted for in a similar way;thus, malachite green, the tetramethyldiaminotriphenylmethanecompound, corresponds with tetramethylmagenta, a tetramethyltri-aminotriphenylmethane, the colour of which once more becomesgreen on acetylation of the amino-group; the colour of the malachitegreen is therefore of the first, and that of magenta of the secondorder.The absorption spectra of various members of the triphenyl-methane group have brought out some unexpected relations.Ithas been generally believed that only such quinonoid compounds ofthis group as possess an auxochromic group in the para-position to67 R. M’illstatter and J. Piccard, Be?.., 1908, 41, 1465 ; A., 1908, i, 915ORGANIC CHEMISTRY. 111the methane carbon atom, are dyes68 ; but the fact that fuchsone,CPh,:C,H,:O, and benzaurin, OH*C,H,-CPh:C,H,:O, on the onehand, and fuchsonimonium chloride, CPh,:C,H4:NH,Cl, and thecorresponding amino-derivative (Doebner’s violet),NH2*C,H,*CPli: C,H4: NH,Cl,also yield similar absorption curves, makes this view ~ntenable.~gAttention may be directed t o a research70 on the reduction oftriphenylmethane dyes by formic acid to triphenylmethane, andultimately to an aniIine and a diphenylmethane; and to anextended series of experiments71 on the action of ammonia andalkylamines on triphenylmethane dyes.The simple amine bases,NHR-CAr,, seem always to be the first product, but are in generalmore readily hydrolysed to the carbinol than the first examplesof the type.72The investigation of the benzoquinoneimine dyes has made clearit far-reaching similarity with those of the triphenylmethane series.73Safranine and the simpler indamine, (NH,Ph*N:C,H,:NH), werechosen, and the changes of constitution accompanying change inthe medium were mainly followed spectroscopically.Mention should be made in this section of an interesting attempt 74to refer the production of tha many dyes, aniline black, indulines,nigrosines, etc., which are obtained in the oxidation of aniline, totwo simple quinonoid reactions, namely, ‘‘ direct addition ” t o anethylene linking (I), and “indirect addition” (11).By action ofthe oxidising agent, these benzenoid products again becomequinonoid, and condensation proceeds further.X XH X X H(1.) (11.1Lakes.-The investigation of the co-01. dinative compounds, mainlyof stannic chloride with the carbonyl group,75 has led to the very68 A. von Baeyer, Annulen, 1907, 354, 152 ; A., 1907, i, 757. R. bIeyPr and 0.69 R. Meyer and 0. Fischer, Ber., 1913, 46, 70 ; A., ii, 167.70 A.Guyot and A. Kovache, Compt. rend., 1913, 156, 1324 ; A . , i, 847.71 E. Noeltiog and J. Saas, Ber., 1913, 46, 952 ; A., i, 522 ; cornitare E. Norlting72 V. Villiger and E. Kopetschni, ibid., 1912, 45, 2910 ; A., 1912, i, 1030.73 F. Kehrmanii, E. Havas and E. Graudmougin, ibid., 1913, 46, 2131 ; A . , i,75 Ann. Report, 1912, 139 ; P. Pfeiffer, Annulen, 1911, 383, 92; A., 1911, i, 788.Fischer, Ber., 1911, M, 1944; A., 1911, i, 723.and K. Philipp, Ber., 1908, 41, 579 ; A . , 1908, i, 295.908. 7J A. G. Green, T., 1913, 103, 92.;112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.interesting discovery 76 of a series of substituted tin compoundsor internal complex salts which are o3tained by merely heatingthe former in solution or suspension in benzene, thus:The co-ordinative compounds are only converted into complexsalts when a hydroxy-group is in the ortho-position with respectto the carbonyl group.Whm there are two hydroxy-groups, suchas in 2 : 4-dihydroxybenzophenone, a substituted derivative con-taining only one SnC1, is formed, whence it may be concludedthat the ortho-placed hydroxyl group is alone involved. Theco-ordinative compounds of some methyl ethers, as alizarin dimethylether, decompose in the same way, methyl chloride being evolved.I n this reaction of stannic chloride only with the o-hydroxylgroup, the hydroxy-ketones show a remarkable contrast in theirbehaviour with bases. Only those hydroxy-ketones in which thehydroxy-group is in some other position than the ortho relative t othe carbonyl group, such as 2-hydroxyanthraquinone, 2 : 6-di-hydroxyanthraquinonone, alizarin, and so forth, form pyridinesalts ; moreover, the number of molecules of pyridine which combinewith one molecule of the hydroxy-ketone are invariably less thanthe number of hydroxyl groups by the number of the ortho-placedhydroxyl groups.That the meta-hydroxyl group is more acidicthan the ortho- is shown by the following facts: Z-hydroxyanthra-quinone dissolves easily in 1 per cent. aqueous sodium carbonate,whilst l-hydroxyanthraquinone does not; and alizarin and potassiumacetate form the m-potassium salt.77The absorption spectra of hydroxyanthraquinones also indicatesome peculiar condition of the hydroxy-groups in the peri-positionto the carbonyl, as the curve of the alkali salts of l-hydroxy- isquite different from that of 2-hydroxy-anthraquinone; 1 : 4- and1 : 5-dihydroxy- resemble a l-hydroxy-anthraquinone in thisrespect.78The inhibition of normal salt formation with the o-hydroxylgroup is attributed to a relation (internal complex salt) existingbetween this group and the ketone, thus: I '\\, ; thisco-ordinative linking accounts for the conversion of the co-ordinativecompounds with tin chloride into the substituted derivatives.These SnCl, derivatives of the o-hydroxyquinones are closely relatedR-CZO()--(pH76 P.Pfeiffer, Arcizalen, 1913, 398, 137 ; A., i, 879.77 W. H. Perkin, T., 1899, 75, 434.78 R. Meyer and 0. Fischcr, Bcr.) 1913, 46, 85; A . , ii, 1CSORGANIC CHEMISTRY.113to the tin lakes, which contain no chlorine. The SnCl, derivativeof alizarin in solution in pyridine is converted by water into alake, which dyes silk and wool. It is suggested that the lakes havethe constitution :The relation is further emphasised by. the fact that in dyes ofthe mordant class the hydroxyl group is always in the o- or peri-position to the chromophoric group.Triarylmethyl and Aimlogous Substances.During the period under review a number of researches79 haveappeared which, although adding new members to this class, andremoving some obscurities, have not done much to solve themystery of their constitution or to harmonise the different viewswhich have been expressed.80I n Gomberg’s most recent publications, he still emphasises thequinocarbonium theory, and finds much additional evidence in thebehaviour of the phenylxanthone salts,81 which he maintains arecarbonium salts, whereas Kehrmann claims them as oxonium salts.82I n this series instances have now been obtained, when the colouredform, to which Gomberg ascribes the quinocarbonium form (I),is stable in the absence of excess of acid.The additional acid (orneutral salt) does not therefore cause the colour by unitingco-ordinatively with the colourless Salk c‘ halochromy ”), as Pfeiffer 83has supposed. The presence of a hydroxy-group in certain positions,and to a less degree of a methoxy-group, are the favourable con-c1(1.) (11.1ditions. This stability of the quinocarbonium salt is accompaniedby a corresponding instability of the colourless benzocarboniumsalt (11).Acetoxy- and benzoyloxy-groups have the opposite effect;the benzocarbonium salts are the more stable, and, moreover, thequinocarbonium salts, produced by addition of acids or salts, are79 W. Schlenk, Ber., 1913, 46, 1475, 1482 ; A., i, 610, J. Schmidlin, Ber.,1912, 45, 3171, 3183, 3188, 3193, 3203 ; A.. i, 32, 33, 34, 46, 50. M. Gomberg,J. Anzer. Chem Soc., 1913, 35, 200 ; A . , i, 257.*O Ann. Report, 1912, 139.81 M. Gomberg and C . J. West, J. Amer. Chem. Soc., 1912, 34, 1529 ; A . , i, 27.HEP.-VOL. X. I82 A m . Report, 1912, 132. 83 r w , 139114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.only faintly coloured.the behaviour of the pbromo-derivative :ClStriking evidence for the theory is found in(111.)the p-bromobenzocarbonium chloride (111) yields a quinocarboniumsalt (IV), which, however, passes back into a pchlorobenzo-carbonium salt (VI) with elimination of bromine.The theory also gains greatly from the proof of the desmotropyof hydroxytriphenylcarbinols, which seem.s most simply accountedfor as benzenoid-quinonoid tautomerism.The highly conflictingstatements as to the properties of this compound which are foundin the literature are thereby harmonised.84The colourless form (m. p. 162-163O) separates from the alkalinesolution on addition of ammonium chloride, and the yellow form(m. p. 139-140O) on acidifying with acetic acid. Each can beseparately crystallised from appropriate solvents, but acid mediaconvert the colourless into the coloured.Light effects the sametransformation. Both desmotropes give the same red hydrochloride,CPh2:CBH4<:H, which is identical with that obtained. fromfuchsone, and is converted into fuchsone by molecular silver.85The results of the many researches on the subject have ledGomberg t o withdraw somewhat from his former position as tothe relations and structure of triphenylmethyl, where he held thatthe biinolecular compound 86 contains a quinonoid nucleus, and isthe only coloured form. He now suggests that the equilibriumrepresented below expresses best the behaviour of this compound.87CPh, CPh,* CPh,CPh,: 4 1 C6 H4<H \ - f- CP~>C,H,:CPh2 4 184 A. Bistrzycki, Ber., 1903, 36, 2333, 3558 ; A., 1903, i, 639 ; A., 1904, i, 44.K.von Auwers A. von Baeyer and V. Villiger, ibid., 1903, 36, 2774 ; A . , i, 811.and 0. Schroter, ibid., 1903, 36, 3236 ; A., 1903, i, 820.a5 M. Gomberg, J. Amer. Chena. Svc., 1913, 35, 1038; A., i, 1056.86 Ann. Report, 1912, 140. * Ber., 1913, 46, 225 ; A., i, 259ORGANIC CHEMISTRY. 17 5Teryenes a d Hydroaromntic Compounds.The numerous recent additions to the polycyclic compounds, orcompounds with “bridged rings,” has led to several suggestions forextending and in part changing the present nomenclature.88 Theextension of von Baeyer’s system for dicyclic compounds to tri-cyclic compounds, which has re+:eived von Baeyer’s approval?g seemslikely to prove immediately useful. Since each tricyclic systemcontains two tertiary or quaternary carbon atoms in the ring whichare linked by bridges of carbon atoms, these bridges are selectedas the central fa& in the suggested nomenclature, and are repre-sented by numbers, which also give the number of carbon atomsin the bridge.The series of numbers for the four bridges, whichare always present in a tricyclic system, is called the “character-istic,” except in completely symmetric formulze it is necessary todistinguish the bridges further, by using as an index to the numberof the ‘‘ characteristic,” the figure denoting carbon atoms fromwhich a bridge starts or a t which it ends. Unfortunately thenumbering of the atoms in rings a t present in use (Richter’s‘‘Lexikon,” etc.) cannot be adapted to this system. It is suggestedthat a revised method of numbering should be adopted, in which,among other things, the numbering should always start from aquaternary (if possible) carbon atom a t one end of the shortestbridge, and then always proceed clockwise round each bridge inturn.A fuller account is not possible here, but an example willillustrate the scheme: the bornylene derivative, shown in theannexed formula, is called 4 : 5 : 5-trimethyltricycZo-[O, 1, 34,0, 21-octanecarboxylic acid :8 1\ 8 CH,*CH-CH7 UH,-CMe-CH/I 1 ~ . c M ~ , J z%H*C02H.The symbol 3496 refers to the bridge >CH--CMe,CMe< betweenC1 and C3 from the carbon atoms, 4 and 6, of which the bridge, 2,springs.Hydronaphtha1enes.-The elegant method of preparing hydro-aromatic hydrocarbons devised by Willstatter 90 has been used for6 5 488 V.Grignard, Bd.?. SOC. chim., 1912, [iv], 11, 124 ; A . , 1912, i, 177. A.BBhal, ibid., 1912, [iv], 11, 264; -4., 1912, i, 342; Ber., 1900, 33, 3775 ; A., 1901,i, 135.s9 E. Buchner and W. WeigmJ, Bcs.., 1913, 46, 2108 ; A . , i, 887.Ann. Report, 1912, 145.1 116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.preparing dihydronaphthalene for the first time in a pure state91from ac-tetrahydro-B-naphthylamine.Q2There seems to be some uncertainty as t o the constitution of thedihydronaphthalene, for Straw and Lemmel93 have convertedBamberger's A2-compound into an isomeride, which they take to bethe Al-compound; moreover, it is stated that the A*-dihydro-naphthalene is exactly identical with the compound taken byWillstatter and King to be A2-dihydronaphthalene.Menthadienes and Menthenols.94-Great advances have beenmade in the synthesis of this important group of the monocyclicterpenes since an account was given in the Annual Reports (1910).I n the m-menthadiene series (Reports, 1910) a great simplificationof the synthesis of A3:8(9h-menthadiene95 has been found in thepreparation of l-methyl-A3-cycZohexene3-carboxylic acid from1-methyl-cyclohexane-4-one ; the series of transformations is shownin the following scheme; the carboxyl group is introduced bysuccessive treatment with sodamide and carbon dioxide :Of the o-menthadienes, of which no representative has yet beendiscovered in natural essential oils, five of the six possiblementhenols and menthadienes have now been synthesised.TheA2-menthenol (Me = 1) and the corresponding menthadiene are aloneunknown.HO-C Me, €IO*CMe, HO*C!Me,I I IHO- CMe, HO*CMe, HO* CMe,I I I f\lMB\/?)Me ;OM. \/ \/(Unknown.)The syntheses of the ortho- resemble in general those used forg1 E. Bamberger and W. Lodter, Ber., 1887, 20, 1706 ; A. , 1888, 292 ; 1896, i,92 R. Willstiitter and V. L. King, ;bid., 1913, 46, 525 ; A., i, 353.L(3 Ber., 1913, 46, 232, 1051 ; A, i, 256, 455.9.1 A very lucid historical summary of syntheses in the terpene group was pre-sented by Professor W. H. Perkin, jun. , to the 8th International Congress of AppliedChemistry, VI, 224.99.g5 B. D. W. Luff and W. H. Perkin, T., 1910, 97, 2147ORGANIC CHEMISTRY.117the para-series ; starting from o-toluic acid, Al-o-menthen-8-0196 andA1:8(g)-~-menthadiene are synthesised by the steps shown in thefollowing scheme :This pair was also prepared in an entirely different way fromb-acetobutyl bromide and ethyl sodioacetoacetate, which yieldfinally l-methyl-Al-cyclohexenyl methyl ketone :from which the menthenol is obtained directly by means ofmagnesium methyl iodide. 6-Hydroxy-o-toluic acid, which is itselfprepared by fusion of naphthalene-1 : 3 : 5-trisulphonic acid withpotassium hydroxide, is the starting point of the synthesis ofA6- and A6-o-menthen-8-01. The mixture of l-methyl-A5- andl-methyl-A6-cyclohexene-2-carboxylic acids, which are obtained a tone stage in the process, could only be separated by taking advan-tage of the fact that the A5-acid esterifies, and the A5-ester hydro-lyses more rapidly than the corresponding A6-compounds.It is interesting to note in this connexion that a new terpene,crithmeneF7 has been isolated from Crithmum mam'tinurn (Sardinia).A consideration of all its characters, including the fact that ityields a crystalline dihydrochloride, identical with that fromterpinene, has led to the suggmtion that it is A1:7-4 :s-p-menthadiene,CH,: C<Eg::g2>C: C Me2, hitherto unknown.Dimeth~Zcyc1ohexadienes.-Exact knowledge of the dimethyl-cydohexadienes is yet in the main wanting. Some of the sub-stances appearing under this heading in the literature can scarcelyhave the constitutions ascribed to them.The 1 : 4-dimethyl-A1:4-cycZohexadiene, prepared by Auwers,98 has been obtained in apure state and accurately described Cantharene, obtained byPiccard from the natural cantharidine, was classed as an ortho-dimethyl derivative; it has now been shown to be 1 : 2-dimethyl-A2:6-cycZohexadiene 99 by a very simple synthesis ; l-methyl-A6-cycZo-hexen-2-one (I) yields 1 : 2-dirnethyl-A6-cyclohexen-2-01 (11), thegb: W. H. Perkin, jnn., and others, T., 1911, 99, 118, 518, 526, 727, 741.97 L. Francesconi and E. Sernagiotto, Atti R. Accnd. Lincci, 1913, [v], 22, i, 231,99 W. N. Haworth, T., 1913, 103, 1242.312, 382 ; A., i, 636. 98 Ber., 1908, 41, 1816; A., 1908, i, 520118 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.terpineol of cmtharene series, which on dehydration passes into thehexadiene (111) :.,CIMe<CMe:CH ‘CH-CH, >CH,0 (111.)Although there is no doubt of the identity of the synthetic andnatural hydrocarbon, the absence of crystalline additive halogencompounds makes comparison more difficult.I n a similar way 1 : 3-dimethyl-A1:3-cyclohexadiene is preparedCH, Another interesting and simple synthesis 1 niay be(annexed formula) from 1 : l-dimethylcyclohexane-CH2 ‘HZ 3 : 5-dione (dimethylhydroresorcinol) ; the ketone groupsare reduced, the hydroxy-groups replaced by bromine,and then the two bromine atoms eliminated by zincdust with formation of the trimethylene ring.A remarkably simple synthesis of dicyclo-[ 1,3, 31-nonanederivatives2 is worthy of note.Ethyl malonate and formaldehydeyield a mixture of methyl methylenemalonate and methyl methylene-bismalonate and methyl pentaneaayyEehexacarboxylate,3 all ofwhich are converted under the influence of sodium methoxide intomethyl dicyclo-[l, 3,3]-nonane2 : 6-dione-l : 3 : 5 : 7-tetracarboxyl-ate (I). The latter passes directly, or through a series of inter-mediaries, illto dic?yclo-[l, 3,3]-nonane-2 : 6dione (11), for theconstitution of which the authors bring forward decisive evidence.from 1 -met hyl-41-cy clo hexen-3-one.F-,--,K /\ noted in that of 3 : 3-dimethyldicycZo-[O, 1, 31-hexane\/C M ~ ~$lH,~F(CO,Me)*~O 9H2*7H-5!0CO,Me*yH QH, QH*CO,Me -+ YH2 FH, YHzCO-C(CO,Me)* CH, (70-GH-CH,(J.1 (11.1Camph,ene.-Fresh light has been thrown on the constitution ofthis hydrocarbon during t,he current year by some importantresearches.It would now appear that Wagner’s formula (I) canalone represent reactions of the compound; and is now acceptedprovisionally by Aschan,4 although this entails a profound trans-formation of the carbon skeleton during the oxidation by alkalinepermanganate, when camphenic acid is formed.1 N. D. Zalinski and A. E. Uspenski, Ber., 1913, 46, 1466 ; A . , i, 607.H. Meerwein and W. Schurmmn, Annalen, 1913, 398, 196 ; A . , i, 869.W. H. Perkin, jun., and W. N. Hawortli, T., 1898, 73, 330 ; \V. H. Perkin,jun., and J. F. Bottomley, ibid., 1900, 74, 294.Annalen, 1913, 398, 299 ; .1., i, 886ORGANIC CHEMISTRY. 119Moreover, the fact that the oxidation both of bornylene and ofcamphene by hydrogen peroxide (in the latter case also by per-manganate) yields camphenanic and isocamphenariic acids, suggestscloser relation of the hydrocarbons than Wagner's formula indi-cates.5The reaction of camphene with ethyl diazoacetate (first used byBraren and Buchner6 as a reagent with unsaturated cyclic hydro-carbons) yields 2 : 2-dimethylnorcamphane-3-spirocyclopropanecarb-oxylic acid (111), which gave on oxidation cyclopropane-1 : 1 : 2-tri-carboxylic acid.I f camphene possessed an endocyclic, as inAschan's formula (11), instead of a semicyclic linking, cyclopropme-1 : 2 : 3-tricarboxylic acid would be the final product.7I n a similar manner bornylene and methyl diazoacetate react,forming methyl 4 : 5 : 5-trimethyltricyclo-[O, 1, 34y6, 2l-octane-2-carb-oxylate (formula, see p.lls), which on oxidation yields a cyclo-propanel : 2 : 3-tricarboxylic acid. This behaviour is in accord withthe usual formula for bornylene. The optical properties of these newderivatives of camphene and bornylene show the exaltation charac-teristic of tricyclic compounds.A reinvestigation 8 of the constitution of the compounds formedby the degradation of camphenic acid, on which the constitutionof this acid was based by Aschan, has proved that Haworth andKing9 were right in their contention that Aschan had assignedan incorrect; formula t o the final product, a lactonedicarboxylicacid. This acid has now been reduced to isocamphoronic acid,C0,H*CH2*CMe,*CH(C02H)*CH,-C02H, and hence is derived froma hydroxytricarboxylic acid of the formula :CO,H*CH( OH) CMe,* CH(C0,H)*CH,-C02H.Since the lactone-carboxylic acid can also be converted into astereoisomeride, it can only have the formula IV:CH2*FH-CMe2CH,*CH-C:CH2(1.1I QH2 ICH2*CH,.ICH-CMe,I 1Q"2 I,CH-C-CH, Y \/CH*C02H(111.)C0,H-CH,*QH-QMe,9H2 GHCH,*CH-CHG. G. Henderson and W. Caw, T., 1913, 103, 1543.Ber., 1901, %, 982 ; A., 1901, i, 385.7 E. Buchner and W. Weigand, ibid., 1913, 4, 759, 2108 ; A., i, 376, 887.a 0. Aschan, Zoc. cit. Ann. Report, 1912, 149120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Collateral evidence in favour of Wagner's formula is found inthe conversion of a-chloroallocamphanecarboxylic acid (I) into twoisomeric camphanecarboxylic acids (I1 and 111) by elimination ofhydrogen chloride, a reaction quite analogous to the formation ofcamphene from bornyl chloride.10 Further, it has now beenOH,* QH-CH, CH,*FH--CH, CH,*SH-CH,UH, I CCl*CO,H CH,- --C*CO,H CH-!-- i CH*Co,HI CMe2 I I CMe2 1 I CMe2 I\ IC:CH,(1.1 (11.) (111.)I/ CH,:C\ /CMeshown that nitrogen trioxide converts camphene into a nitro-compound, l-nitrocamphene, which yields l-camphenilone and nitro-methane with alcoholic ammonia.and camphenilanaldoxime,C8H,,:CH*CH:NOH, on reduction.11/--YH\ F"H2 QH, p e ,CII,-CH--C:CK*NO, 'Fenchone and iso3'enchone.-Semmler's formula (11) for fenchoneis now accepted by Aschan, and ap analogous formula for iso-fenchone (111) suggested, as the constitution of isofenchocamphoricacid (IV) lias now been established by its conversion throughhydroxyisofenchocamphoric acid (V) to tetramethylglutaric acidCMe,* 7 H-- C H, CMe2*?H-CH, CMe2*y H-CH,I QH I f- I CH, 1 ---+ 1 7H2 I'CMeOK-- -CH CH,--CMe*CH*OH II YH2 I I YH2I HO*CH--CMe*CH,(1.)J.CMe,*~H--OR,CH,--CMe*CO1 4 CMe,*VH--CH, CMP,*FH=CO,HCO---CMe*CH, CH,-CMe*CO,Hf- 1 ( 7 3 2 I(11.) (111.)$I Me,-CO,H CNe,oQ(OH)*CO,HI $IH, --3 CH,*CMe,*CO,HCH,-CMe*CO,H(V.) (VI.)lo J. Houben and E. Willfroth, Ber., 1913, 46, 2283 ; A . , i, 970.l1 W. Jagelki, ibid., 1899, 32, 1498. P. Lipp, Annalen, 1913, 399, 241 ; A., i,1077ORGANIC CHEMISTRY. 121(VI), which has been synthesised.l2 The relation of P-pinolene (I),renamed cyclofenchene, to the fenchones is very simply explainedby the reduction of the trimethylene ring, which is remarkablysensitive to acids, but stable to oxidising agents.The opticalexaltation observed by Ostling, moreover, provides additionalevidence for this structure.13The conversion of pinene (I) into the fenchene-type of carbon-nucleus, which has been a difficulty in assigning formuh, is nowrepresented as but another instance of the pinacone-transf ormation,fenchyl chloride (11) being formed instead of the pinene hydro-chloride :CH,*QMe*C HCICII,*CH-CMe,CH=CMe*CH CH,*CClMe*CHI Y H 2 I(1.1 (11.)Fenchyl chloride, as pinene hydrochloride, reacts normallyalthough not free from side-reactions with magnesium and carbondioxide, yielding hydrof enchenecarboxylic acid ; hydrodif encheneand hydrodifenchenecarboxylic acids are the main by-products.14Ca7.yophyZZeize.s.-Although the reactions of this hydrocarbon, orrather mixture of closely allied hydrocarbons,l5 are such as to leadsome observers to consider it a naphthalene derivative, Semmler 16has now brought forward evidence which renders it more probablethat the crude material consists of a mixture of two dicyclicsesquiterpenes, which are mutually convertible into one another.By careful oxidation, primarily by ozone, and by consideration ofthe physical constants of the products, the presence of a trimethyl-cyclobutane ring il; each is demonstrated.The two hydrocarbonsare named terpcaryophyllene (I) and Zimcaryophyllene (11), fromthe analogy of the suggested structures t o those of limonene andterpinolene respectively :C €3, $' Me--C *CH: CMe,C'H-CH,-CMeC H, yMe--CH*CH,* CMe: CH,CH-CH= CMel/QMe2 I P M e 2 ll12(1.j (11.)Innalen, 1912, 387, 1 ; A., 1912, i, 198.J. I. Michaeleokn and W. P. 1Javorski, J. Russ. Phys. Chm. Soc., 1900, 32, 328 ; A., 1900, i, 586.l3 T., 1912, 101, 457.14 G. Komppa and S. V. Hintikka, Ber., 1913, 46, 645 ; A., i, 375.l5 C. W. Haarmann, ibid., 1909, 42, 1062; 1910; 43, 1505 ; A . , 1909, i, 400 ;E. Deussen, ibid., 1909, 42, 376, 680 ; Awnden, 1912, 388, 136 ;16 F. W. Semmler, Ber., 1911, &, 3657 ; 1912, 45, 1384 ; A . , 1912, i, 120, 479.1910, i, 496.A., 1912, i, 368122 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.Na turab Products.Caoutchoucs.-Harries’ 17 researches on the rate of decompositionof the diozonides of natural and of the various forms of artificialcaoutchoucs give the most exact means of discrimination yet dis-covered.The decomposition of “ sodium ” caoutchouc diozonidesfrom isoprene and butadiene is quite different from that of natural,or the artificial “ normal” caoutchoucs from isoprene or butadiene.Comparison of the decomposition curves of the diozonides of“ normal ” caoutchoucs (“ normal ” butadiene caoutchouc) andA1:f~-cycZooctadiene shows a very remarkable similarity. The di-ozonides are also alike in the amount of succinaldehyde producedin the decomposition and in the want of response t o hydrogenperoxide test. Harries is confidently of the opinion that ‘( normal ”caoutchoucs must contain an eight-ring of the type found in theoctadiene.The additive compounds of the caoutchoucs with the halogenacids are of the type C10H18X2,1* except that the synthetic caout-choucs only combine with one molecule of hydrogen iodide.Thesecompounds yield, on elimination of halogen acid, a material resem-bling artificial caoutchouc, but when sodium hydroxide is usedinstead of an organic base for this purpose, the material differssharply in its inability to form ozonides.It is suggested that the ethylenic linkings are conjugated in theeightiring in the one case (I) whilst they are not in natural or“ normal ” caoutchouc (11), thus :(1.1 (11.)Carminic A cid, Kemtes Dye, and Stick-lac Dye.lQ-This groupof (‘insect” dyes, of which the best known is cochineal (carminicacid), have long defied the efforts of chemists to determine theirchemical nature.They have now been shown t o be anthraquinonederivatives, although Liebermann 2O had decided that such was notpossible, since he failed to obtain anthracene from carminic acid bydistillation with zinc dust.Carminic acid, when pure, is now found to give a mixture ofanthracene and methylanthracene. Carminic acid yields, ODl7 C. D. Harries, Annalen, 1913, 395, 211, 264 ; A., i, 284, 287.l8 C. 0. Weber, Ber., 1900, 33, 779; A . , 1900, i, 353 ; C. 1). Harries, Ber.,1913, 4&, 733; A., i, 380. F. W. Hinrichsen, 11. Quc~isell, and E. Kindscher,Ber., 1913, 46, 1283, 1287 ; A ., i, 637.19 0. Dimioth (with W. Scheurer and S. Goldschmidt), Annalen, 1913, 399, 1,43, 62 ; A., i, 977, 980, 981.C. Liebermann and W. A. ran Dorp, ibid., 1872, 163, 97 ; d., 1872, 706ORGANIC CHEMISTRY. 123oxidation with hydrogen peroxide, finally a compound which hasbeen identified as 2 : 6-dihydroxy-8-methyl-a-naphthaquinonecarb-oxylic acid,CO*8*0HCO*C*CO,H 'CO, K*C,HM~(OH)<The position of the hydroxyl groups is determined by the resem-blance of this acid to 2 : 6-dihydroxy-a-naphthaquinone, which hasbeen specially synthesised for the purpose.21 On oxidation of theacid, carminazarin is produced, and has been shown to be2 : 3 : 6-trihydroxy-8-methyl-a-naphthaquinone-5-carboxylic acid. Byfusion with potassium hydroxide, carminic acid yields coccinin,22which is oxidised through coccinone to cochenillic acid (5-hydroxy-toluene-2 : 3 : 4-tricarboxylic acid).Since both coccinin andcoccinone give the characteristic colour reactions of hydroxyanthra-quinones, i t is suggested that their constitutions are representedby the formulae :Coocinone.fl(OH)*C*CMe -- -7 F I c:,HRT~(oH)~< I IC H---C*C(CO,H):C*OHCoccinin.Carminic acid is then taken t o possess this carbon skeleton (C14);it is supposed that the five carbon atoms, which are lost in thealkali fusion, are arranged in a side-chain, and not as an additionalfourth ring, as Liebermann suggested.23Kermasic acid, the main constituent of kermes dye, is a simplercompound, the constitution of which is shown in the formula:Cochenillic acid can easily be obtained from it.Laccaic acid, C20H14010, which is the main constituent of stick-lacdye, is not, as was formerly thought, identical with, but closelyrelated to, carminic acid.Since it yields a series of derivatives,which closely resemble those obtained from carminic acid, and alsogive the colour reactions of 2 : 6-dihydroxy-a-naphthaquinone, therecan be little doubt that it is also an anthraquinone derivative.K. J. P. ORTON.21 0. Diniroth and B. Keikovius, Annnkib, 1913, 399, 36 ; A . , i, 979.22 H. Hlssiwetz and N. Grabowski, ibid., 1867, 141, 329.23 C. Liebermann and H. Tominkel, Ber., 1904, 37, 3344 ; 1909, 42, 1922 ; A . ,1904, i, 90.3 ; 1909, i, 486124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.PART III.-HETEROCYCLIC DIVI s ION.I n drawing up a report in this section the main difficulty whichits writer encounters is certainly not a lack of material.Yet evenwhen the material is apparently plentiful the task of the reporteris not an easy one, for much of the work that is done doss not Ienditself to summarisation, whilst other portions of the field are solittle investigated that the advance of our knowledge in themduring the current year couId only bs expressed in the baldestform. Thus, on the one hand, there is a temptation t o diffusenesswhich would end in a reproduction of the original papers practi-cally verbatim; aad on the other side there is the difficulty ofavoiding a certain aridity in the style which would defeat the mainobject of the Reports. The present year has furnished examplesof both these drawbacks.From the point of view of the relation of chemistry to othersciences, the most important work has been carried out in thechlorophyll and hzemine groups; but the reasoning in this part ofthe subject is so intricate and the structures of the substances dealtwith are so complex that it appears almost impossible to do morethan touch on one or two points which appear of most importance;whilst others, which next year may appear of even greater interest,have perforce been sacrificed to lack of space and a fear of over-loading one section of the Report.Turning to other subjects, the progress of syntheses in thealkaloid group has not attained the same grade as was shown lastyear.I n 1912 this section of the subject showed a very markedadvance; but the present year has been devoted rather to theeven more difficult work of determining constitutions by means ofdegradation reactions. Needless to say, this type of work is muchmore difficult to summarise than the other, for the results of aseries of synthetic reactions can be expressed comprehensibly bymeans of formulz with hardly any further explanation, whereasthe views obtained by means of the degradation method can onlybe reproduced by a summary of reasoning which may be extremelydifficult to condense without loss of clarity. Further, the resultsobtained by the method of degradation have always to be takenwith a certain amount of reserve, as anyone who reads the backnumbers of the Journals will have realised.Among the synthetic heterocyclic substances the chief work ofthe year appears to have been carried out in connexion with indoleand its derivatives, and our knowledge in this field has beenconsiderably advanced.The, cyanogen group also has receiveda certain amount of attention, and in this connexion the discoverORGANIC CHEMISTRY. 125of carbon subnitride suggests that our knowledge of the cyanogenderivatives may be on the verge of a great extension.The problem of residual affinity is being slowly elucidated, andit is not without interest to find that it is being attacked in themost widely-differing field@ of the subject. In this way any possi-bility of a narrow outlook upon the question is automaticallyshelved, and it is to be hoped that more workers will enter thisdivision of the subject.Cyanuric Acid, Cyamelide and Ammebide.Last year Chattaway 1 put forward a comprehensive explanationto account for the reactions of carbamide, cyanic acid, and otherallied compounds.His view was based on the assumption thatail the reactions dealt with were simply examples of the well-knowntendency of the carbonyl radicle to add on groups such as R*NH*Ror R*OH, this addition being followed by a wandering of a hydrogenatom from oxygen t o nitrogen, as expressed by the followingsymbols :O H .N:C:O + HON: *N:c<~. - ONH-CO-N: .The formation of cyanuric acid from carbamide may, on thishypothesis, be represented by the following formulze :This view has been criticised by E.A. Werner: who has broughtforward another explanation to account for the phenomena.According to him, cyanic acid is so unstable as to preclude itsexistence in unimolecular form, and it must also be assumed to bea mixture of two isomeric keto- and enol-forms. The enol-formtends to pass into the keto-form in the following manner:Enol. Phase (a). Phase (a). Keto.Since an interval of time must elapse while the hydrogen atomis migrating from oxygen to nitrogen, either a valency of theoxygen atom becomes momentarily free [Phase (a)], followed imme-diately by a momentary liberation of a carbon valency [Phase ( b ) ]T., 1912, 101, 170. Ibid., 1913, 103, 1010, 2275126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.when the hydrogen atom unites with nitrogen, or, on the otherhand, when the hydrogen akom has attained the position representedin phase (a) a simultaneous liberation of the respective valenciesoccurs, their union within the molecule giving rise to the keto-formof the acid.Since this is also taken as an unstable configurationi t is concluded that the chief result will be the formation ofcyamelide by the union of three molecules in phase ( b ) , a6 shownbelow :/' 0-C(:NH),,'x. /O-C(:NH)\'0-C(:NH) /O i"+ HN:CHN:C"\*------c(: *H)Three moleculre in phase ( 6 ) . Cyamelide (Hantzscli's formula).According to this theory, cyamelide is not the result of thepolymerisation of cyanic acid pre-existing in the keto-form, but isthe product of the natural tendency t o stable equilibrium formedwhilst the acid is in the act of changing from one form to another.Thus, on this theory, the prime condition for the production ofcyamelide is that cyanic acid must exist in the enol form.A thigh temperatures, such as are found when carbamide is disso-ciated by heat, cyanic acid is assumed to be liberated in the keto-form, which at once polymerises to cyanuric acid, no cyamelideKeto. Intermediate phase. End (unstable),$3 mols. not fornied. // N----*----C (0 H )N NN c (OH)\N --+ HO-CH\N : C( OH)/HO*C .I//#' N= C( OH) (Stable result ofreaction. )'\a. ..The following scheme shows the manner in which the whole cycleof changes undergone by carbamide and biuret under the action ofheat can be expressed on Werner's hypothesis :/NH3 NH3NH:C\I = +0 HN:CO IIOCNy meriaation(KNCO), [cyanuric acid]Arnmelide.HN : c<g;2+H 0-CNi i N : C=O HH N:CL, = N H<~::::>(::NH + H,OBiuret.ORGANIC CHEM JSTRY. 127A comparison of the two suggested explanations shows that theyboth depend on the formation of unstable intermediate stages, butthat Chattam-ay assumes the formation of additive products, whilstWerner lays down the postulate that intramolecular vibration canbe adduced to cover the ground. Werner's views certainly havethe advantage of simplicity. At the present day the older ideathat all reactions take place in two stages, first addition, and thendecomposition, is coming once more into favour in some fields: andi t seems probable that it will sooner or later be more generallycombined with thO dynamic conception of the molecule; so thatthe progress of all organic reactions will be ascribed, first, tointramolecular vibration resulting in the freeing of residualaffinity, and secondly, to the formation of an unstable complex,which, by a rearrangement of affinity and possibly the eliminationof certain atoms, passes into a third and stable condition.Thestudy of such problems is a t present possible only by physicalmeans, such as refractometry or spectroscopy, and it would beinteresting to see methods such as these applied to this problem.Meanwhile, the quantitative data which have been acquired in thisregion of chemistry are of great value from the theoretical pointof view.Car b 0% Su b nitride .A compound of considerable interest has been discovered duringthe year among ths derivatives of carbon and nitrogen.3 It hasbeen obtained by heating tetraiodoglyoxaline, which loses threeatoms of iodine at 180°, and parts with the last halogen atom whenthe temperature is raised to 420O:1SO" 420" !?'*'I> I ~2 C,N,I --? C,N,.CI--NWhen the heating process is carried out in such a way that nofusion of the substance occurs, the compound obtained resemblessoot; but if the material is allowed to melt, the product has theappearance of the carbon which is obtained by the decompositionof sugar.Long heating renders the sooty substance hard andsiqilar to graphite, with a colour varying between brownish-blackand greyish-black.All forms are insoluble in indifferent solvents,and burn in a manner similar to charcoal; they have the propertyof absorbing gases, and they also are capable of removing colouringmatters from sugar solutions.With aqueous alkali or aqueous solutions of acid, neitherammonia nor hydrocyanic acid is liberated; but nitric acid attacksthe substance with the production of carbon dioxide. When heatedin a tube with soda-lime, ammonia is given off; whilst cyanogenis quantitatively produced when the substance is heated in aH. Pauly and E. Waltziuger, Ber., 1913, 46, 3129 ; A . , i, 1311128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.stream of nitrogen. If the heating is carried out in an atmosphereof carbon dioxide, carbon monoxide and free nitrogen are formed,along with cyanogen.I n many respects the new substance appears to be allied on theone hand to paracyanogen, and on the other to animal charcoal.Its relation to paracyanogen appears in the method of preparation,for just as it is obtained by heating tetraiodoglyoxaline, so para-cyanogen is prepared by heating cyanuric iodide above 200°4 :Both compounds when heated a t high temperatures are almostcompletely decomposed into dicyanogen, although in the case ofcarbon subnitride one-third of the carbon remains behind in itselementary form.This reaction throws considerable doubt on theconception of paracyanogen as a polymeric form of cyanogen, forit seems more probable that both paracyanogen and carbon sub-nitride belong to a class of substances which liberate cyanogen asthe result of some deep-rooted change in their constitutions underthe influence of high temperatures.I n its relation to animal charcoal an even more striking similarityof properties is exhibited.Carbon subnitride, as was alreadymentioned, resembles animal charcoal in its physical properties ;it has the power of absorbing gases just as charcoal does; it burnsin a similar manner, and is equally insoluble in indifferent solvents.Both animal charcoal and carbon subnitride have the property ofliberating ammonia on treatment with sodaAime ; both substancesyield cyanogen when heated to redness, but whilst carbon subnitrideis completely dissolved by molten alkali, yielding hydrocyanic acidand carbon dioxide, animal charcoal is not thus soluble.It appearsas if animal charcoal belonged to the same class of substances, butit is probably such an impure compound, as might be expectedfrom its mode of formation, that it cannot show the exact bebaviourof the pure carbon subnitride in its entirety.It might be suggested that carbon subnitride was not a truecompound, but merely a loose physical complex of carbon %ndnitrogen. The production of hydrocyanic acid from it on fusionwith alkali tells against this hypothesis, as do the facts that itsnitrogen content is not affected by pressure, and appears to beunchanged even over wide intervals of temperature. The fact thatit contains more than 40 per cent.of nitrogen, whilst ordinarycharcoal absorbs only about one-fifth per cent. of its own weight ofnitrogen, appears to eliminate this hypothesis as to the nature ofthe nitride.4 P. Klason, J. pr. Chem., 1886, [ii], 34, 159; A . , 1886, 1001ORGAN LC CHEMISI'BI'. 129The intermediate product in the preparation of carbon subnitrideis also of some interest. It has the composition (C3N21)s, and formsa sepia-tinted powder of the consistency of lampblack. It has noodour of iodine, is insoluble in all ordinary solvents and also incold acids, but hot nitric acid attacks it with the formation ofbrown solutions and liberation of iodine. When heated with 15 percent. potassium hydroxide solution i t gives off no ammonia; but it!dissolves In fused alkali, with the liberation of slight amounts ofammonia. Attempts to discover the exact position of the iodineatom in its structure by employing methyl derivatives of glyoxalineinstead of the parent substance have so far proved fruitless.It is too early yet t o ascribe a structural formula to carbonsubnibride, and it seems best to take for granted that the substancecan be represented by the empirical formula (C3N2)%.It appearsprobable that further investigation of this new class of substances,of which carbon subnitride and paracyanogen appear to be theonly representativw yet obtained in a pure condition, will lead tovery interesting results.A ntipyrinediazoniurn Salts and their Derivatives.Although the vad majority of the diazo-compounds known at thepresent time belong to the aromatic series, there are a few isolatedcasw noted in the literature in which the diazotisable amino-groupis attached, not to a benzene ring, but to a heterocyclic nucleus. Aseries of investigations5 has been begun this year with the objectof ascertaining within what limits the diazo-reaction is manifestedby bases which do not contain amino-groups attached to aromaticnuclei.It appears probable that if an amino-group is to be capable ofdiazotisation it must be attached to a nucleus containing anunsaturated group ; but the converse proposition is not necessarilytrue, for cases are known in which an amino-radicle attached to anunsaturated group is not capable of forming diazo-compounds ; forexample, 6-amino-2 : 4-dimethylpyrimidine (cyanmethine), althoughi t contains a cyclic system and an arrangement of valencies similart o that in benzene, behaves like an aliphatic amine, and does notresemble aniline in its powers of diazotisation :C'yaniiiethinr.G.T. Morgan ltud J. Reilly, T., 1913,REP.-VOL. X.103, 808, 1494.130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Several bases of the pyrazole series have been diazotised, and ithas now been found that i t is possible to isolate l-phenyl-2:3-di-methylpyrazolone-4-diazonium chloride, which is produced by diazo-tising 4 - amino-1-phenyl- 2 : 3 - dimetliylpyrazolone (4-aminoanti-p yrine).It is suggested that substances of this type may be of interestin connexion with the theory of the structure of diazo-compounds.If a co-ordination between the diazonium complex and the unsatur-ated ring be assumed, as some authors have proposed, then in thecase of the aiitipyrine derivatives an analogous conjugation mightbe expected t o take place, According to Morgan and Reilly, ageneral formula for these diazonium compounds might be repre-sented by:IWith regard to the reactions of these compounds i t appears that acertain parallelism can be traced betw,een their reactions with P-naph-thylamine on the one hand and the P-diketones and @-keto-esters onthe other.When two labile hydrogen atoms are present, condensa-tion takes place; but when only one labile hydrogen atom is foundin the compound the reaction does not follow the normal course;for example, the compound I couples with the diazonium derivative,whilst the substance I1 does not:H HC'OU pl r s.Does not couple.Acetylacetone can be coupled with the antipyrinediazoniumcompounds, yielding an azo-derivative of the following structure :but when, instead of acetylacetone, its methyl derivative,CH,-C!O-CH(CTH3)*CO-CH,,is employed, the reaction is somewhat different. Coupling occurs,but i t is accompanied by hydrolysis, resulting in the eliminationof an acetyl radicle, and i t seems probable that a compound of thetype shown below is produced: Y P h - C o > ~ ~ ~ : ~ o ~ ~ < CO*CH,N Me* CMe GH,A study of the absorption spectra6 of some of these substaricers6 The authors refer to some of their curves as " extinction " curves, but from thecontext it appears probable that they are ordinary absorption curves obtained by thousual qualitative methodORGANIC CHEMISTRY. 131has been carried out, with interesting results.The case of ethylacetoacetate will suffice to show the general nature of the dataobtained. Ethyl acetoacetate in alcoholic solution shows no selec-tive absorption. On coupling it with the antipyriiiediazoniumderivative, however, a substance is produced which has a well-marked absorption band in the region 2200-3200, with its heada t 2600. The sodium derivative of the coupling product has anabsorption spectrum practically identical with that of the azwcompound itself. Now it will be recalled that the addition of alkalito an alcoholic solution of ethyl acetoacetate results in the develop-ment of a baud in the absorption spectrum of the substance, thehead of the band lying a t 3700.From these data Morgan andReilly conclude that the antipyrineazo-compound has the saiiieenolic atructure as the P-diketone compound itself, and they furtherpoint to the results obtained in the case of the co-ordinated vana-dium derivatives of diketones7 in support of their view; and bythis line of reasoning they come to the conclusion that there is itparallelism between the structures of the ordinary metallic deriv-atives of the diketones and those of the antipyrineazo-derivativas,which may be expressed in the two equilibrium formulz below :0 0 p..I ICH,*C i4(Na) CH,*C H(Na) -A II i 7- H*C 6 H*C 0C' H (Na)CH,*C -A 1 1 ! \/B0\/ 7 R0,/ \.CH,*C k(Na)/\\/ NMe*CMe \/CH,*C' H(Na) --yP"-"O>C.N:N.C I1 i, i T- T"h-co>C.N:N.C I I 0NRle*CMeF: R (7 RThis involves, of course, the assumption that a band with its heada t a frequency of 2600 units may be traced to the same origin asone which has its head a t 3700 units, the difference being possiblyascribed to the very different molecular weights of the twosubstances .The A Zkaloids.Last year was marked by a very rapid extension of our know-ledge of tlia alkaloid group on the synthetic side, but during thei C.7'. Morgati and H. W. MOSS, T., 1913, 103, 7s.K 132 ANXUAL KEPOttTS ON THE PROGRESS OF CHEMISTRY.present year the major part of the investigations lias been directedtoward the determination of the constitution of various membersof the group by the usual process of degradation; thus the Reportfor the current year cannot seek to produce the same type ofconnected narrative which is possible when the final stages ofsynthetic work are concerned; but instead of this, all that ispossible to do is to give a rapid survey of the various sections ofthe field, and draw attention to the general trend of the year'swork.Coniine, which has already given rise t o a considerable amountof research, has again been pressed into service in the stereo-chemical field.Up to the present time only one case is known8 iiiwhich two isomeric forms of a diquaternaxy ammonium salt coii-taining two asymmetric nitrogen atoms have been isolated.Itwas thought that further progress might be rendered possible byemploying a substance which, in addition to the nitrogen atoms,contained an asymmetric carbon atom also, and with this aim anattempt was made to isolate all the possible forms of ethylenebis-d-coniine :When the nitrogen atoms in this substance are converted intoquinquevalent ones by salt-formation, there are three possibleisozeric forms which may be represented schematically by thefollowing symbols, in which the plus and minus signs refer to thedextro- or lzvo-configurations of the asymmetric atoms :I. (N+,C+) ...... (N+,C+).11. (N-,C+) ...... (N-,C+).111. (N + ,C + ) ...... (N - ,C + ) .An attempt to obtain these has been o d y partly successful, twoisomerides having been isolated, whilst the third possible isomeridehas hitherto defied preparation.It is supposed that this unknowncompound probably corresponds with the third configuration-possi-bility, and that under the conditions of experiment it is too unstableto exist, but passes into the configuration represented by the firstformula.I n the quinoline group the work of the year has not been markedby any great advance in our knowledge, and a reporter mustperforze confin0 himself to a brief mention of the vwious pointswhich ha.ve been brought forward.A simple method of preparation of hydroquinine esters has beenworked out,1o which depends on the action of hydrogen unders E. and 0. Wedekind, Ber., 1910, 43, 2707 ; A . , 1910, i, 834.E.Wedekind and F. Ney, ibid., 1913, 46, 1895 ; A . , i, 893.lo Voreinigte Chininfabriken Zimmer & Co., D.N.-P. 251936 ; A . , i, 85ORGANIC CHEMlSTRY. 133pressure in the presence of colloidal metals; for instance, whenquinine ethyl carbonate, mixed with dilute sulphuric acid and atrace of colloidal palladium, is shaken in an atmosphere of hydrogenunder pressure until no more hydrogen is absorbed, it is foundthat hydroquinine ethyl carbonate is formed. Some of them estersappear to have a therapeutic value.11The investigations of Skraup and Koenigs in previous years haveresulted in the conclusion that the alkaloids of the quinine seriesare all derivatives of a parent substance having the structureshown below, and, further, that these alkaloids may be classifiedinto a series of pairs :CH,*~H-~H.CH : CH,\/\/NChemically speaking, I-quinine closely resembles d-quinidine,and the other alkaloids of the group may be bracketed together inthe following series : cinchonine-cinchonidine, hydroquinine-hydro-quinidine, hydrocinchonine-hydrocinchonidine ; thus there ar0 fourpairs of similar compounds in the group, and an examination ofthe formula will show that there are four asymmetric carbon atomsin it, numbered (I) to ( 4 ) .It has been shown with regard to theatoms (3) and (4) that these have the same spatial arrangement ineach of the eight alkaloids, and it; therefore follows that the differ-ences between the various pairs must be ascribed to the spatialarrangements of the atoms around the asymmetric carbon atoms(1) and (2).Now if the hydroxyl group attached to the asymmetric atom (1)is replaced by a hydrogen atom it is found that (in the case ofcinchonine and cinchonidine, for example) the end-products of thereactions are still different, for cinchonine gives rise to one parti-cular product, whilst cinchonidine produces an isomeric substance.Since in the course of the reactions the asymmetry of the carbonatom (1) disappears, it is quite evident that this asymmetry cannotbe the origin of the difference between the two compounds, and it,seems very probable that the difference between them is to besought in the different arrangements of the groups round thecarbon atom (2).l1 Vereinigte Chininfabriken Zimmer & Co., D.R. -P. 253357 ; A., i, 85134 ANNUAL REPORTS ON THE PROGRESS OF CHE3IIS'I'LZT.On tlie other hand, if the secondary alcoholic radicle attachedto the carbon atom (1) is oxidised to a carbonyl group, tlie asym-metry of the carbon ato,m (2) remains, on paper a t least, just aslittle affected as in the case of the reduction of the hydroxylradicle; yet in this case the end-products from cinchonine andcinchonidine are identical, To explain this it has been assumedthat tsutomeric change takes place as shown in the formulz below,ail$ that in this way the one form can pass into the other, so thatit is impossible to isolate either substance in a pure form:2 1 *eH*&O* -C:C(OR)* .This view, however, leaves an important point out of considera-tion, namely, the bearing on the problem of the configuration ofthe groups associated with the asymmetric carbon atom (1).Now all the alkaloids of the cinchona group yield on decomposi-tion the same substance, meroquinonine (I), which can be reduccdt o ciiicholeupone (11), and from the study of the progress of the$l H,-CO,HCHyH,*CO,HCKA H,c/'+c H CN : c H , FJ,C/ >CH*CH,*CH,H,CJ ICH,H2C(,!CB, \/ NHNH(1.1 (11.)various reactions i t appears that the spatial arrangement of theasymmetric atoms (3) and (4) remains unaffected through thedecompositions.It remained to be proved, however, that, whenthe process was reversed and a synthesis of the alkaloid carriedout, the configurations of the four asymmetric atoms would possessthe configurations found in the natural alkaloids.Taking theformula of cinchotoxine to be that expressed below, it will be seenthat its conversion into cinchoninone entails the production of thenew asymmetric carbon atom (a), whilst the further step tociiichonirie leads to the formation of the fourth asymmetriccentre (1) :3 4CH,*CH--CH*CH:CH, CH,*CH--C H*CH :CH2CH II I CH, 1I t C;,H,;N*CO NK-C H, &H-N---C! H,ICinchotoxino.C,H,N*COCinch u II i no n eBRGANIC CHEMISTRY. 13.5CH;CK--CH*CH:CH,I AH2 I II f 7 4 I I2C1H-N---CH2IIC',H,NCi ri ch on ine.When such a synthesis is carried out there are two possiblecourses before us. First, the asymmetry of the two carbon atoms(3) and (4) already present in the molecule may exert no influenceon the mode of forrnation of the two new ones (1) and (2); or,secondly, owing to the presence of the asymmetric centres (3) and(4) there may be a selective formation of the new centres, suchas is found in asymmetric syntheses.I n the first case there will bea quantitatively equal yield of the four possible stereoisomerides intwo pairs of anbipodes, which can be represented by the formulzbelow :PY IH-C-NPYN-C-HI YY H-C-NPY I N-C-HI I IH-C-OH H-C-OH HO-A-H HO-C-HI I I IQuin. Quin. Quin. Quiii.whilst the second postulate leads to the assumption that certain ofthe configurations will be favoured, and consequently there willbe an unequal production of the various possible compounds in thereaction.'I'his theoretical view has been tested in the case of hydro-cinchotoxine,l~ and it has been made reasonably certain that thesesynthetic processes do proceed in an asymmetric manner.Hydro-cinchoninine, if i t were an equimolecalar mixture of two activecompounds, would produce on reduction equal quantities of hydro-cilzchonine and hydrocinchonidine, but in actual practice it isfound that the former substance is produced in 50 per cent. yield,whilst only 10 per cent. of the latter substance is found in thereaction mixture. The change of hydrocinchonicine, which containstwo asymmetric centres, into an alkaloid with four asymmetriccentres, proceeds asymmetrically, and it appears that of the fourpossible conl'igurations those which are most favoured are thosefound among the natural alkaloids, hydrocinchonine predominat-ing, whilst hydrocinchonidine ia the next in the scale of formation.A.Kaufmann and M. Huber, Bcr., 1913, 46, 2913 ; A., i, 1222136 AKXUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A study of the toxic effects of some synthetic compounds alliedt o the cinchona alkaloids has been made,13 but the results obtaineddo not seem to lend themselves to summarisation.I n the morphine group the work of the year has been confinedto one or two isolated investigations, chief among which appeart o be the following. An examination of the crystalline characterof codeine, narcotine, and other alkaloids derived from opium showsthat they can be pbtained in the superfused condition, as theycan be caused t o become solid without crystallisation taking place.They are all polymorphic, codeine having no less than five crystal-line forms.l* Attempts have been made to prepare a hydroxy-codeine from aminocodeine by diazotisation, but the results do notappear to have been very definite.15 A method of obtaining hydro-genised alkaloids of the morphine group by the action of hydrogenin the presence of colloidal palladium appears to work as well asthe corresponding method in the case of the cinchona alkaloids.16Morphine glucoside has been prepared.17 The formation ofapomorphine in solutions of morphine which have been heatedor allowed to remain has been investigated, and it appears thatthe change of one substance into the other does not take place.15An attempt has been made to synthesise apomorphine, but it wasnot successful.^^The syntheses of cotarnine and hydrastinine have been carriedont in the following manner 2o : When homomyristicylamineformate is heated it yields formylhomomyristicylamine (I), whichcan be converted into norcotarnine (11) by the action of phos-phoryl chloride and subsequent treatment with alkali :(1.) (11.)The methiodide of this substance (11) is identical with thehydriodide of cotarnine. A similar method has been employed toproduce norhydrastinine,21 and from this substance hydrastinineand various hornologues have been produced.22A study of some condensation products of cotarnine has beenA.Kaufmann, Ber., 1913, @, 1823 ; A . , i, 763.F.Ferrein, Arbeiten nus dem Pharmaz. Imt. Berlin, 9, 153 ; A., i, 750.l4 I?. Gaubert, Compt. rcnd., 1913, 156, 1161 ; A., i, 643.I6 H. and B. Oldenberg, D.R.-P. 260233 ; A., i, 1093.l7 C. Mannich, Annulen, 1912, 394, 223 ; A., i, 87.l9 F. W. Kay and A. Pictet, T., 1913, 103, 947.M. Feinberg, Zeitsch. pltyrriol. Ch,em., 1913, 84, 363 ; A., i, 643.H. Decker and I?. Becker, Annaien, 1913, 395, 328 ; A., i, 290.Ibid.22 H, Decker, kfltnlc~cn, 1913, 395, 321 ; A . , i, 290ORGANIC CHEMISTRY. 137made, and the results are of considerable importance ; the consti-tution of anhydrocotarnineacetophenone has been examined, andthis substance has been shown to be an isoquinoline derivative.%An investigation of the action of acetal on tetrahydropapa-verine2* has been carried out in the hope of throwing some lighton the constitution of corydaline, but the results have not broughtour knowledge very much forward.Instead of corydalines, thereaction appears to produce two other isomeric substances, whichhave been named coralydines, since they have the same compositionas the corydalines, but differ from these in their properties.The derivatives of dihydroberberine have been submitted to avery exhaustive examination, especially with regard to theirbehaviour when they are electrolytically reduced.25 It is foundthat alkyl- or aryl-dihydroberberine derivatives react with methyliodide to form the hydriodides of bases which are termed de-alkyl-(or de-aryl-)Z\7-metliyldihydroberberines. When reduced by theelectrolytic method, each of the de-baw yields two reduc-tion-products, a- and @-hydro-de-alkyl(or aryl-)N-methyldihydrober-berines. The nature of the alkyl or aryl group appears to haveno effect on the general character of all these compounds, so thati t appears that the general constitution of the whole series is thesame.From the fact that when the debenzyl derivative is oxidised itis converted Eito hydrastinine and 3 : 4dimethoxy-2styrylbenzalde-hyde, the deduction is made that the debenzyl compound may berepresented by the following formula :Against this, however, must be set the fact that the de-basecannot be reduced, nor does i t react with bromine, and it seemspossible that a better expression of the substance properties mightbe found by assuming that it contains a skeleton of the followingtype :CH2PhTwo complete formula= have been suggested for debenzyl-AT-methyldihydroberberine, but it is admitted that neither of themis completely satisfactory.2n E.Hope and R. Robinson, Y'., 1913, 103, 361.23 M. Freund (in conjunction with K. Fleischer, H. Commessmann, H. Haiiiniel,A. Pictet and S. Malinowski, Ber., 1913, 46, 2688; A., i, 1224.I). Steinberger and E. Zorn), Annnlen, 1913, 397, 1 ; A., i, 502138 ANNUAL REPOKTS ON THE PROGRESS OF CWEI\IISl’HY.On reduction of the R-dihydroberberines (R being a n slkyl oraryl radicle) it is found that each compound produces two stereo-isomeric R-tetrahydroberberines, from which two stereoisomericmethiodides (I) have been prepared.These two methiodides whentreated with silver oxide and subsequently with alkali, yield thesame de-base. When R is a benzyl radicle the de-base probablyhas the formula 11; if R is an isopropyl group the de-base has thestructure 111, whilst if R is a methyl, ethyl, isoamyl, n-octyl, orphenyl group, the de-base has the formula (IV):The conversion of berberine into hydrastinine 26 can be carriedout in another way. On electrolytic reduction, phenyldihydro-berberine yields two stereoisomeric phenyltetrahydroberberines, andwhen either of these is digested with silver chloride and subse-quently reduced with sodium amalgam, i t yields a base which onoxidation produces hydrastinine.The constitution of the anhydro-bases derived from tetrahydro-berberine presents another knotty problem.Tetrahydroberberineis a racemic compound, the laevo-isomeride of which is Z-canadine.It was found by Voss and Gadamer27 that the same opticallyinactive ethyl-anhydro-base can be obtained from either the racemictetrahydroberberine or the optically active canadine. Now theoreti-cally it is possible to obtain three hypothetical carbinol bases (I, 11,and 111) from tetrahydroberberine ethohydroxide, and of these (I)and (111) can lose water with the formation of the correspondingaiihydro-bases (Ia) and (IIIa) respectively :2tj E. Merck, D.R.-P. 259873; A . , i, 1095.$7 A. Voss apd J. Gadamer, Arch. Pharm., 1910, 248, 43 ; A . , 1910, i, 415ORGANIC CHEMISTRY. 139The formation of an inactive anhydro-base from I-canadine showsthat this base must have the formula IIIa, since the other formula(Ia) contains the original asymmetric carbon atom unchanged.This conclusion has been criticised by McDavid, Perkin, andRobinson28 on the ground that the formula IIIa contains a ten-membered ring and is therefore improbable.I n the present year the investigation has been carried furtherby the work of Pyman29 on I-canadine.It wa.s found that whenI-canadine methohydroxide is evaporated to dryness in a vacuuma mixture of three anhydro-bases results, which have been termedA, B, and C respectively. When the corresponding racemicsubstance (tetrahydroberberine methohydroxide) is similarly treatedonly the two bases A and B are obtained, the third base not beingfound among the reaction products.A quantitative examination ofthe reaction products shows that the base A is formed in the sameyield in both cases, whilst the yield of base B in the case of tetra-liydroberberine is almost exactly equal to the combined yields ofB + C in the cas2 of the optically active canadine derivative. Thissuggests that B is the racemic form of C, and this hypothesisaccounts for the fact that none of C can be detected when thestarting material is the racemic tetrahydroberberine derivative.With regard to the base C, Pyman concludes that i t must have28 J . W. RlcDavid, W. H. Perkin, jun., and It. Robinson, Y'., 1912, 101, 1218.29 I?. L. Pyrnan, ibid,, 1913, 103, 817140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,the following structure, which contain.; an asymmetric carboiiatom :CH, J ;'\/\(J-H/\/I SH / \ b e CH,CH2(Corresponds with In.)Siiice B, from evidence into which it is unnecessary to enterhere, may be regarded as being the racemic form of C, it also hasthe formula Ia. This leaves the constitution of the base A to beexpressed by the formula IIIa, since there are only two pmsibleformula open (In and IIIa), and Ia has already been appropriatedfor B and C.Another point now arises. It was found that the production ofthe base A from either tetrahydroberberine methohydroxide orfrom Z-canadine methohydroxide is a process which depends oncertain experimental conditions ; thus if either of the methoxidesis evaporated to dryness under atmospheric pressure, no trace ofthe bass A is produced.This has been traced to the fact that underthese conditions the base A is unstable, and is converted intotetrahydroberberine methohydroxide, which, in turn, is changedinto base B.The whole course of the formation of the three anhydro-basesmay be expressed in the scheme below30:CJ32 I I CH ! I CH, I I \/\&/\/ \/\(-JJ&/\/ \/\CH/\/,\/"-\,CH, ' I 1 -+I ,\,N"'\JCH, Z),/k--,,CH2 I\/\&*)\/H,C [\ CH, H,C CH, H,C I \ CH,Me OH Me OHmethohydroxidr. methohydroxide.I Canadiiie Base A. cll-Tetrah ydroberberiiie4 CH2 ! I \/\ (J H/\/ICH, !EH /\/N I 1 Me CHCJ%CH2/\\/&Me CH, CH2Base C. Base B.The constitution of axoiiitine3l seems to be one of the problemswhich are nearing their solution.It appears to have the structurerepresented by :The asterisks over the asymmetric carbon atoms indicate that the compoundsare optically active.31 0. L. Brady, T., 1913, 103, 1821ORGANIC CHEMIS'I'HY. I4Lso that i t is now necessary to determine the constitution of theCgH,N nucleus.It has now 32 been placed beyond doubt that the constitutions ofIiarmine and liaririaliiie are actually those suggested last year.:':'OM0/\i Il!almine. Ilarmaline.The following is an outline of the proof. The methoxy-group iseliminated from the harmine nucleus by a series of reactions, intothe details of which i t is not necessary to enter. The resultingcompound is termed harman. The point next a t issue is tomine whether harman is a quinoline derivative or a memberisoquinoliiie group.The two possible structures are A and/\I Ideter-of theH :\/\/N NH(-4.) (B. 1In order to distinguish one from the other, it became necessaryto produce synthetically a substance corresponding with one orother of the structures; and substance I1 was chosen. The usualindole synthesis was found not to be applicable when the benzenenucleus of indole is replaced by a quinoline ring; so recourse washad to another series of reactions. Condensation of o-aminobenz-aldehyde with succinic a.nhydride produces o-aldehydosuccinanilicacid (I), which is then converted into carbostyril-3-acetic acid (11).CHO L'HCH,*CO,H I 1\ / \ P O/\/ C H, C H2* C 0 HNH N(1- 1 (11.)32 IV. 11.Perkin, jun., and K. Robinson, T., 1913, 103, 1973.3.l A,c,i. Report, 1912, 159: T., 1912, 101, 1775142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The amicie of this substance when boiled witli pliosphoryl cliloride,undergoes a peculiar change, whicli resnlts in the formation ofchloronorisoharman (111) :CH(11.) (JIJ.) (IV. 1The Grignard reaction produces from this substance the corre-sponding methyl derivative (IV).This substance was found t o be isomeric with harman, and it istherefore termed isoharman. From this i t follows that liarinancannot have the quiiioline structure A , but must contain an iso-qiiinoline nuclem corresponding with the formula B above.The Naphthat hioxins.The investigation of the su1ph;des of &naphthol, which was dealtwith in last year's report,34 has resulted in the discovery of a verypeculiar case of isomerism.35 It will be recalled that two isomericforms of fl-naphthol sulphide exist, and that, when they aredehydrated, each forms a peculiar naphthathioxin.The two naph-thathioxins are not simply polymorphous substances, as they differfrom each other in chemical properties to some extent, and eachof them gives rise to a distinct set of derivatives. By the actionof acetyl chloride on fl-naphthasulphonium-quinone (I), monochloro-naphthathioxin (11) was obtained. By converting this into theoxide (111) and subsequent treatment with hydrochloric acid, itwas found possible to prepare dichloronaphthathioxin (IV) :Attempts were then made to prepare the same substances by thedirect action of hydrogen chloride on the oxide of naphthathioxin,and mono- and di-halogen derivatives were actually obtained inthis way.On examination, however, i t was found that these newJ4 A?wz. Report, 1912, 160.y5 T. J. IC'olan and S. Smiles, T., 1913, 103, 340, 901 ; P., 1913, 29, 197ORGANlC CHEMISTRY. 143derivatives did not correspond with the substances prepared by t'hcother method.Two possible explanations of this phenomenon suggest tliem-selves. I n the first place, the differences observed may be due tostructural isomerism arising from a difference in the positions ofthe chlorine atoms in the molecules; or, alternatively, there maybe a difference betwen the two parental thioxins which persists inthe derivatives.Evidence has now been brought forward whicllappears t o exclude the first of these possibilities; and furtherinvestigation has shown that naphthathioxin actually exists in twoisomeric forms, namely, naphthathioxin and isonaphthathioxin.With regard to the constitutions of these two substances, thefollowing data appear to be relevant. The molecular weights oftlie two isomerides measured in the same solvent are found tocorrespond with the simple molecular formula which results when amolecular weight of water is subtracted from two molecular weightsof &naphthol sulphide. The normal thioxin shows tlie usualCharacter of subst,ances of this class. The isothioxin appears t ocontain the thioxin ring also. Further, it appears most probablethat in both compounds this ring is attached to the naphthalenenuclei in the up-positions.From this evidence it appears that theskeletons of the two thioxins are similar; and the cause of theisomerism must be sought in the remaining portion of the molecule,namely, the naphthalene nuclei. This conclusion, however, is alsoapplicable to the isomerism of the two sulphides of P-naphthol itself,since the properties of the two forms in which it occurs recall thoseof the two thioxins. It is suggested that in all these cases thereis a difference between the distributions of affinity in the naph-thalene nuclei which might be represented by the two formulaebelow. The first formula may be taken as representing the truea-sulphide of &naphthol, whilst I1 corresponds with the isomericform which is obtained by the reduction of naphthasulphonitnn-auinone :A similar ideb was advanced by C'ollie,36 who, from spatial con-siderations, concluded that it4 was probable that one of the naphtha-lene rings was olefinic in character, whilst the other was benzenoid,although under ordinary conditions it was possible that, owing t ointramolecular vibration, each ring became olefinoid in turn.J.N. Collie, T., 1897, 71, 1017144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.WillstBtter and Waser 37 have also suggested something of the samekind. The phenomenon might be expressed thus:It is not without interest that 3-phenanthrylamine 38 behaves tosome extent like the naphthol derivatives.It occurs in two forms,one of which is obtained from the acetyl derivative of the other.Each substance gives a series of crystalline salts which, on decom-position, regenerate the isomeride from which they were produced.There appears to be no doubt that further investigations in thisline will widen our conceptions of the distribution of residualaffinity within the molecule; and since the case of the sulphides of&naphthol is evidently not an isolated one, it is to be hoped thatany further examples of the same kind which are detected will becarefully investigated.The Indole Group.Reference to the literature betrays the fact that, whilst a veryconsiderable amount of research has been carried out on thehomologues of indole, the parent substance itself has been to agreat extent neglected.The reason f o r this state of affairs mustbe sought in the fact that the hydrogen atom of indole is capableof changing its position from the nitrogen to the neighbouringcarbon atom, and vice versa. The result of such tautomeric changeis that when any reagent acts on indole the main reaction may beaccompanied by one or more minor reactions which coniplicate theend-products. Further, the decomposition products obtained whenthe indole nucleus is attacked are very liable t o undergo furtherchanges which result in t.he formation of highly complicated com-pounds the constitutions of which are very difficult to ascertain.To avoid this difficulty, sonie means must be found to fix thehydrogen atom and prevent intramolecular change during furtherreactions.Alkylation of the compound would accomplish this, butit would be practically impossible to remove the alkyl radicle a ta later stage in the proceedings. The beiizoyl radicle does not offerany such difficulty, as it can be attached to the nucleus with ease,and removed from it with equal readiness.1-Benzoylindole39 has been proved to be a most useful substancein this field; for by its aid the action of halogens on the indole37 R. Willstatter and E. Waser, Ber., 1911, 441, 3431 ; A . , 1912, i, 17.98 A . Werner and J. liunz, ibid., 1901, 34, 2525 ; d., 1901, i, ti96.K. Weissgerber, ibid., 1913, 46, 651 ; A., i, 387ORGANIC CHEMISTRY. 145nucleus can be studied without aiiy of the drawbacks which ariseiii connexion with the ordinary violent interaction between indoleand the halogens.The reaction between the halogen and l-benzoyl-indole is carried out in carbon disulphide solution, and yields ofabout 80 per cent. of the theoretical are obtainable. The benzoylderivative is then liydrolysed by rneaiis of ammonia, and in this waythe pure indole halogen substitution product is obtained.The same substance has been employed in order to produce areaction which has hitherto been unattainable in the parent indole.It is well known that in the indole homologues it is possible toopen up the pyrrole ring in such a way as to produce derivatives ofanthranilic acid; but when oxidising agents are applied t o indoleitself the reaction-products are by no means so simple as is thecase with the homologous compounds.It has been found, however,that 1-benzoylindole can be oxidised in acetone solution by meansof pernianganate with the production of benzoylantliraiiilic acid,which can easily be hydrolysed to its parent substance.A study of the action of ozonised air on solutions of the saltsof 2- and 3-indolecarboxylic acids has been made; and it appearsthat the 2-acid is not markedly affected, whereas the 3-acid producesa good yield of indigotin. The rapidity of the action is sufficientlygreat t o allow the experiment to be used for lecture demonstrationpurposes.I n the distillation of large quantities of nearly pure indole, i t isfound that a small quantity of a product of high boiling point isleft behind in the distilling flask.An examination of this sub-stance40 shows it to be a trimeric form of indole. It might havebeen expected, from analogy to pyrrole, that tri-indole could beprepared by the action of condensing agents on indole, but experi-ment has shown that this is not the case, for no characteristic com-pound is produced in these cir~umsta~nces.41 Tri-indole is of sonieinterest in certain of its characteristics. On distillation in avacuum it gives a quantitative yield of indole; acetic anhydrideproduces a monoacetyl, benzoy! chloride a monobenzoyl derivative.Benzoyltri-indole, when heated in a vacuuin, decomposes into indoleand benzoyldi-indole. These acyl derivatives of the indole seriesare apparently #-derivatives, for the, acid radicles cannot be removedfrom them by the action of the usual hydrolytic agents.Severalformuls might be suggested for the structure of tri-indole, but theone that appears most satisfactory in view of its reactions is thefollowing :40 K. Keller, Ber., 1915, 46, 726 ; A . , i, 403 ; see also H. Odtlo, Oarzetta, 1913,d1 See, however, If. Scholtz, d i d . , 1082; A . , i, 520.43, i, 385 ; A . , i, 755, and M. Scholtz, Eey., 1913, 46, 1032 ; A . , j, 520.REP.-VOL. X. 146 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Further investigations have been made during the year on thereactivity of the P-unsubstituted pyrrole ring.42 It will be recalledthat a fairly close parallelism seems to exist between the S-unsub-stituted indole derivatives on the one hand and the primaryaromatic amines and the phenols on tne other.43 It has now beenshown that the 3-unsubstituted indoles react with pyridine andcyanogen bromide, yielding dyes which have the general formula :These substances are closely allied to the pyridine dyes which canbe obtained from the aromatic amines.A new method of obtaining substituted indole derivatives 44 hasbeen discovered, which depends on the action of heat and a catalyst,such as cuprous chloride or zinc chloride, on the hydrazones ofaldehydes and ketones.For example, when methyl ethyl ketone-phenylhydrazone is heated to 180-230° in the presence of a traceof cuprous chloride, a 60 per cent. yield, of 2 : 3-dimethylindole isproduced.Another method of obtaining indole derivatives is based onthe condensation of primary atnd secondary aromatic amines withthe esters of mesoxalic acid.45 Aniline yields an ester of dioxindole-3-carboxylic acid :/' C(OH)*CO,R I i-lc*\'\/NHwhich can be saponified with aqueous potassium hydroxide in theabsence of air with the production of dioxindole.This last sub-stance, if left exposed to air in an open vessel, is rapidly oxidisedto isatin. Other aromatic amines yield the corresponding products.The synthesis of indole itself has been accomplished in a somewhatroundabout manner, starting from o-toluidine.46 The amine is con-verted into the oxalo-derivative, and then fused with some sub-42 W. IGnig and R. Schreckenbach, J. p r . Chem., 1913, [ii], 87, 241 ; A ., i, 400.4y W. Konig, ibid., 1911, Lii), 84, 194 ; A., 1911, i, 808.44 A. E. Arbuzov aiid V. M. Tichvinski, J. Buss. Phys. Chem. Soc., 1913, 45,j5 A. Guyot and J. Martinet, Compt. rend., 1913, 156, 1625; A., i, 756.Jti IV. Aiadelung, Ber., 1912, 45, 3521 ; A., i, 91.70 ; A., i, 388ORGANIC CHEMISTRE'. 147stances, such as barium hydroxide, which have the property ofacting as alkaline condensing agents without producing hydrolysisof the acyl derivatives. I n this way an indolecarboxylic acid isproduced, which, 011 distillation, decomposes into the parent sub-stance.The reactions of the methyl radicle when directly attached toan aromatic or heterocyclic nucleus are of great importance fromthe point of view of the problem of residual affinity; f o r i t is wellknown that such methyl radicles possess many properties whichbring them into line with the methyl group of an acetyl radicle.Further accumulation of facts in this field is much to be desired;and those which have come to light during the year are of nolittle interest.In the cme of 2-methylindole, the methyl group appears to bevery sensitive to the conditions under which the reaction is carriedout, f o r example, when an aldehyde is allowed to react with2-methylindole in neutral or acidic solution, a di-indylmethanederivative (I) is formed,47 whilst in a strongly acid, alcoholicsolution the end-product is an indolidene compound (TI) .48%Methylindole. ( I .) Di-indylmetliaue derivative.(11. ) Indolidene derivativc.It has beeii found49 that when compounds containing thegrouping -CH,*CO*C€I, are allowed to react with aromaticaldehydes under the influence of condensing reagents, the reactionsare influenced by the nature of the solvent. I n alkaline solutionthe methyl radicle is attacked by the aldehyde, whilst in acidsolution it is the methylene group that is acted on.Now in2-methylindole there is no carbonyl radicle, but instead of it thereis an ethylenic bond; and the question suggests itself whether thereactions of 2-methylindole lend any countenance to the idea thatthere is a parallelism between the groupings -CH,*CO-CH, andCH:C-CH,. The actual experimental results do not tend tosupport this view. I n alkaline solution, the methine group of2-methylindole reacts with aldehydes, but the reaction is not similarto the normal reaction between an aldehyde and a methyl radicle;for it is found that the alcohol which is used as a solvent plays aE.Pischer, Ber., 1886, 19, 2988; A , , 1887, 265.48 M. Freund and G . Lebach, ibid., 1905, 38, 2640 ; A., 1905, i, 663 ; C. n.49 31. Scholtz, ibid., 1913, 46, 2138 ; A . , i, 893.I I a n i e s and G. H. Miiller, ibid., 1902, 35, 966 ; A . , 1902, i, 295.L 148 ANNUAT, REPORTS ON THE PROGRESS OF CHEMISTRY.part in the reaction, giving rise to a compound of the type J. Withinethyl alcohol as a solvent, the analogous 1netliyI derivative isformed, whilst if piperidine is employe4 as a condensing agentinstead of sodium hydroxide solut,ion, a piperidiiie derivative of thetype I1 is produced:(1.1 (11.)When formic acid is allowed t o react with 2-methylindoIe, theformer substance behaves as if i t were an aldehyde, but thereaction appears to take place in two stages.In the first pliase,the iiidde derivative reacts in the indolenin form :and the two hydrogen atoms of the methylene radicle are removedalong with the oxygen atom of th: formic acid caxbonyl group.The second phase of the reaction is brought about by the inter-action between another molecule of 2-methylindole and bhe liydroxylgroup of the formic acid residue in such a way as to protliice2-niethylindolyl-2-methylindolidenemethane :A curious anomaly is shown when o-nitrobenzaldehyde is usedinstead of the oth'er aromatic aldehydes.Instead of the iiorinalcondensation, a reaction takes place which to some extent recallsaldol formation, with the result that a compound of the followingtype is producel:NO,- C~H,*CH(OH ).C<~&>NH.It niiglit be supposed that such a deviation from the normal coursemight be due to the influence of the ortho-substitution of thealdehyde ; but examination Las shown that salicylaldeliyde ando-chlorobenzaldehyde both react in a manner exactly similar t obenzaldehyde, which, of course, proves that ortho-substitution isnot the real cause of the deviation of the nitro-compound fromthe normal.When, instead of aldehydes, ketones 50 are condensed with2-methylindole, the results are quite different, for the reactionfollows another course; for example, when acetone is allowed toact on 2-methylindole under the influence of hydrochloric acid, thefollowing compound is produced :50 BI.Scholtz, Ber., 1913, 46, 1082; A . , i, 520OHGANIC CHEMISTRY. 149This reaction also is very sensitive to any change in the condi-tions under which it is carried out; thus if glacial acetic acid issubstituted for the hydrochloric acid, the reaction product is :NH<CMe C , H 4 ~ C * C M p 2 * C ~ ~ ~ ~ > N H .Methyl ethyl ketone behaves like acetone, but when an attemptwas made to utilise diethyl ketone it was found that no reactiontook place between it and the indole derivative.With ethyl acetoacetate the reaction takes another turn, for onlyone molecule of 2-methylindole reacts with the molecuIe of ethylacetoacetate. The resulting substance has the structure shownbelow :N<3g:>C*C Me*CH,* C0,Et.I n t l ~ e reactions with 2-methylindole the yields are quantita-tive, but when the parent-substance indole is substituted for themethyl derivativo the results are much less satisfactory, althoughthe same types of end-products are produced with acetone, namely:Picolide a,& Pyrindole.Wlien a-picoline is treated with acetic anhydride i t yields acompouiid having the composition CI2Hl4O2N, which has beentermed picolide.This compound appears to be an ili-acetyl deriv-ative, as it shows no basic properties; it contains a ketonic oxygenatom, condenses with two molecules of aromatic aldehydes, anddecomposes, on heating with hydrochloric acid, into a base havingthc composition C8H,N.This last substance was originally termedpyrrocoline, but it lias been re-named pyrindole.51Pyrindole is isomeric with indole, and its constitution lias nowbeen deduced to be:With regard to the constitution of picolide, the following evid-ence has been accumulated. Having no basic properties, i t isprobably an N-acetyl derivative. The second oxygen atom belongsto a carbonyl group, for picolide reacts with one molecule ofphenylhydrazine, hydroxylamine, or semicarbazide ; and when theGrignard reagent is employed, only one carbonyl group reacts with51 M. Scholtz and W. Fraude, BcY., 1913, 46, 1069 ; A . , i, 514150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTHY.it, yielding a tertiary alcohol.Picolide is easily attacked by oxidis-ing agents, and its condensation with two molecules of aromaticaldehydes tends to show that it has two free methyl groups soplaced that they are sensitive to condensing reagents.The only formula which appears to fit in with this evidence is thefollowing :and on this assumption the formation of picolide would be repre-sented by the following scheme:Picolide may be considered to be derived from a parent substanceof the structure :for which the name quinolizine is suggested.follows :The mnversion of picolide into pyrindole may be expremed asWith regard to the reactions of pyrindole, the following appearLike the indole derivatives, it reacts to b3 the aost important.with benzoquinone, yielding diquinonylpyrindole ORGANIC CHEMISTRY.1.51It condenses readily with ketones, two molecules of pyrindolereacting with one molecule of the ketone. Ethyl acetoacetate doesnot react as a normal ketone in this manner, but produces insteada substance which appears t o have the structure shown below,and as can be seen by inspection, the two compounds have reactedin molecular proportions with each other :CH, CH,-CO,Et/-\-c-c-QJd-\ \/\ - N / I \N -/L&&//\CH, CH,*CO,EtIt is not without interest to find that when propionic anhydrideis substituted for acetic anhydride in the reaction of picolideformation, the results are totally different from the " normal "reaction. Propionic anhydride and picoline yield a substancehaving the composition C,,H,,ON, which, from an examination ofits properties, appears to have the constitution :so that it is in no way analogous to picolide.Chlorophyll and Haenrin.The problems relating to the constitutions of these two substancesmay, a t the present time, be regarded as among the most intricatewhich the field of organic chemistry contains.Not only are thereactions complicated in the extreme and the decomposition pro-ducts obtained numerous and complex, but in addition the nomen-clature is to a great extent different from the ordinary; thusanyone who desires t o read up the subject is faced with difficultiesgreater than the ones which ordinarily attend the perusal ofchemical papers. Further, the work is to a great extent dependenton the interpretations that can be placed upon the progress ofcertain reactions in which the reagents are so complex that it isvery difficult t o determine the composition of the substances, o reven the number of carbon atoms which they actually contain, sothat a fairly complete narrative of the work of the year wouldentail the description of reactions and their results in much greaterdetail than is possible within the compass of a Report such m thepresent.It seems well, therefore, on this occasion, to confine theReport to a brief sketch of barest outlines of the work, and t odraw attention in particular to the suggestions put forward withrespect to the structure of chlorophyll and haeminBefore entering into detail, it may be well to recall the rneaniiigof certain terms which have come into use in this field. Chloro-phyll, obtained from plants, was shown last years2 t o be a mixtureof two components, chlorophyll-a and chlorophyll-b.These sub-stances arc derivatives of dicarboxylic acids in which the oiiecnrboxyl radicle is esterified with methyl alcohol, whilst the secondcarboxyl group is esterified with the alcohol phytol. If the pliytolis hydrolysed away, thc monomethyl ester remaining is termed ;tchlorophyllide. By the action of alkali on this chlorophyllide,hydrolysis takes place, the methyl group disappears, and a deep-scated rearrangement of the nucleus occurs, which results in theproduction of a new type of dicarboxylic acid. This new acid istermed a chlorophyllin.All the substances mentioned contain anatom of magnesium within the nucleus. This magnesium atom canbe removed, and its place is then taken by two hydrogen atoms,with the result t h a t a dicarboxylic acid called a porphorin isobtained from the phyllin class.Now just as the chlorophyll derivatives contain an atom ofmagnesium, the haernin derivatives from blood contain an atomof iron, and when this iron atom is removed, the reaction productsare called porphorins as they resemble t o some extent the corre-sponding chlorophyll compounds. From this apparent similaritybetween the chlorophyll and haemin derivatives i t was supposeduntil recently that there was a very close relationship betweenchlorophyll and haemin, and i t waa generally assumed t h a t haeminwas 3 kind of chlorophyll in which iron replaced the magnesiumof true chlorophyll.This idea appears to have been incorrect iiithe light of the present year’s work. I n the succeeding sections anendeavour will be made t o trace the steps in the reasoning whichhave led to this conclusion, and also to throw some light on thecurrent ideas with regard t o the constitutions of chlorophyll andliaernin.The I)eco?riyosition Products of Chlorophyll-a arid Chlorophyll-b.When ordinary chlorophyll is broken down, the final stages ofthe decomposition give rise to two isomeric substances, pyrrophyllinand phyllophyllin, which have the composition MgN,C,,H,,*CO,H,and cannot be converted into each other by ordinary reactions.With the discovery t h a t chlorophyll was not a single compoundbut a mixture of chlorophyll-a and chlorophyll-b came the idea t h a tpyrrophyllin might be a decomposition product of the one variety52 AIL)/.i:l~p)ort, 1012, 165ORGANIC CHEMISTRY. 153(k and i)of chlorophyll, whilst phyllophyllin was the corresponding deriv-ative of the second chlorophyll. Further investigation 53 has shown,however, that this view is incorrect, for when either chlorophyll-aor chlorophyll-b is subjected to degradation reactions, the end-products contain both pyrrophyllin and phyllophyllin. The differ-ence between the two chlorophylls is confined to the substancesthemselves and ths lialf-way stages of the degradation process ;thus in the case of chlorophyll-a the decomposition takes place inaccordaiice with the following scheme :Cllloro~~llyll-a[MgN,~,,H,8O,I(CO,H 12 4 Rubiphyllin -+ Rubiporphorin[ ~fgN,C‘,,H,,l(~O,H),-1’hytochlorin-[I t- Cliloropliyllin-a isoChlorophylliii CG --+ Ph3’tochlori1i-~-I I + [brgN,C,,H,,O](CO,H), J.I IGlaukoporpliorin t- GlaukophyllinRhodoporphorin t- Rhodophyllin drythrophyllin -+ Erythvoporphorin+Pyrroporphorint- Pyrrophyllin Phyllophyllin -+ Phylloporpliorintwhilst with chlorophyll-b the reactions are exprsssed by :Cyanophy 11 in -+ Cyan oporph ori nj / [Mg~,C,,H,,I(CO,H)* .+C&P4C,,H321(CO*H),[ %N,C3, H331 (C O,H).Chlorophyll4From the differences in the above table it is clear that althoughprobably the two chlorophylls both contain some grouping of atomswhich gives rise to pyrrophyllin and phyllophyllin, yet theirintermediate products of decomposition are not by any meansidentical.To explain the fact that a series of similar reactionswhen applied to the one chlorophyll yields results different fromthose obtained with the other chlorophyll, although the end-53 R. Willststtcr, 31. Fischer itlid L. PorsBn, Annnle?i, 1913, 400, 147 ; A . , i,121 5 154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.products are the same in each case, recourse may be had to thelactam formula for chlorophyll, which was described last year 54 :YNH-GOYi I& a Cb,Me*[C,,H,,N,Mg]* C02*C20H39Chlorophyll-a.By the action of alkali on chlorophyll the colour of the corn-ponent a is changed to yellow, whilst that of b becomes red, gradu-ally coming back to green.It is assumed, to account for this, thata lactam ring is broken and a new lactam ring then formed, whilstin the meantime the complex union with the magnesium atom isruptured. I n the c u e of chlorophyll-a the process of lactamisomerism may take place in various ways; for example, in thechange of chlorophyll-a into chlorophyllin, the lactam ring may beproduced from the y-carboxyl group and the 8-amino-radicle, yield-ing *CO*NH*, whereby the carboxy) groups a and fl are left free inthe molecule. In the change of chlorophyll-a into the isomericlactam, isochlorophyllin, the lactam ring may be formed betweenthe a-carboxyl and the y-amino-group, so that in this case twodifferent carboxyl groups, y and 8, ar0 set free.This illustratesthe production of both chlorophyllin and isochlorophyllin from thesame component of chlorophyll, chlorophyll-a. On further treat-ment with alkali these two lactam groups are abolished, and theP-carboxyl radicle also disappears, with the result that a mono-carboxyphyllin is formed in each case. These compounds aredifferent from each other, which suggests that the carboxyl groupleft in the molecule occupies a different position in each of thetwo phyllins. This leads to the conclusion that the phyllin moleculecannot be symmetrical, and the experimental evidence availablepoints also in this direction.A further line of investigation in this field is not withoutinterest. The table on p. 153 shows that when chlorophyllin-a isconverted into glaukophyllin an oxygen atom disappears, and thesuggestion has been made that a carbon atom disappears a t thesame time.This might be accounted for if it be assumed that acarbbnyl group is eliminated from the ring, and that the remainderof the nucleus produces a pyrrole ring as shown below :Y 6NH N HHC{)CH HCI-CH HC"C0 H d ICH -+\/CHWhen the great complexity of the substances is borne in mind54 A:tn. Report, 1912, 166ORGANIC CHEMISTRY, 155it does not seem very strange that the question of whether thecarbon atom remains in the molecule or not should be one whichoff ers considerable analytical difficulties. and this example willsuffice to remind the reader of the complexity of the problem andthe tentative manner in which suggestions have to be made.The Parent Substartces of t h e Yhylliizs mid Porphorins.When chlorophyll is subjected t.0 a series of degradation reactioirsthe products are phyllins, which are carboxylic acids containingmagnesium atoms in their inolecules.Further de'gradation convertsthese into the corresponding porphorins, which are carboxylic acidswith no magnesium atom in the molecule, the metallic atom beingreplaced by hydrogen atoms. Haemin, when subjected to the sameprocesses, also produces porphorins, but these are not identicalwith the chlorophyll decomposition products. The degradationproducts from hzemin and chlorophyll have this in common, how-ever, that when they are subjected tjo energetic reactions, such asoxidation or reduction, the end-products of the reaction in eithercase are found to contain identical products, such as pyrrole deriv-atives. From this it appears probable that all the porphorinscontain some common nucleus, and that the difference between themis due to the different mannei. in which other radicles are attachedto this nucleus in the various compounds.One possible difference of this kind might be sought in thedifferent positions taken up by the carboxyl groups in theporphorin nucleus, and it seemed desirable to prepare the carboxyl-free substances from which the various porphorins are derived inorder to find out whether the position of the carboxyl groups in themolecule was the governing factor in the question.This has nowbeen accomplished,55 and two compounds have been obtained, whichappear to form the nuclei from which the porphorins and phyllinsare derived.These substances have been named aetiophyllin andaetioporphorin, and their compositions are represented byC,,H,,N,Mg and C?31H36N4 respectively. The f ormulz suggestedfor them are given on p. 157.The three porphorins, phylloporphorin, pyrroporphorin, andrhodoporphorin, when heated with soda-lime, lose carbon dioxideand yield aetioporphorin, so that it becomes probable that the differ-ences between the three substances are due to the various positionsoccupied by the carboxyl groups within their molecules. Thereaction is such a violent one, however, that it seems possible thatits results are not necessarily confined to the elimination of carbondioxide ; intramolecular change might occur as well, which would55 R.Willstitiez and BY, Fischer, AmaZe)i, 1913, 400, 182 ; A . , i, 1218156 AhrNURL REPORTS ON THE PROGRESS OF CHEMISTRY.perhaps account for the three substances yielding the same end.product.Themagnesium atom is introduced into the porphorin molecule bytreating the latter in concentrated ethereal solution first withmagnesium methyl iodide and subsequently with sodium dihydrogenphosphate. . I n the case of' some other chlorophyll derivatives theintroduction of magnesium can be carried out bv heating thesubstance under pressure with methyl-alcoholic potassium hydroxideand magnesium ~ x i d e . ~ ~From aeetioporphorit~ i t IS possible to obtain aetiophyllin.The Probable Constitution of Haernin.Hzmin, when treated with hydrobromic acid under certaiiiconditions, produces hzematoporphorin, from which the iron atomof haemin is absent.I f haemin is treated with methyl-alcoholicpotassium hydroxide in the presence of much pyridine, it yieldsthe complex iron derivative of a substance called mesoporphorin,whilst haematoporphorin under the same conditions produces acompound termed haemoporphorin.57 When this is heated withsoda-lime its carboxyl radicles are split off, and the end-productof the reaction is found to be identical with the aetioporphorinproduced by the degradation of chlorophyll. Aetioporphorinhaving the composition C31H36N4, i t follows that its dicarboxylicderivative, haemoporphorin, must correspond with the formulaC,,H,O,N,, and hzemoporphorin is therefore isomeric with thedibasic porphorins derived from chlorophyll. Further, since haemo-porphorin has been shown to be produced from hzmatoporphorinwithout any alteration in the carbon content of the latter substance,it follows that haematoporphorin also must have thirty-three atomsof carbon in its nucleus.Hitherto it has been assumed that therewere thirty-four carbon atoms in the members of this series ofcompounds. It is now more probable that the following composi-tions shouid be ascribed t o the lmmin group:Haemin, C3,H,O,N4FeC1. Haematoporphorin, C33H3806N4.Mesoporphorin , C33&@,N,.Turning next to the question of the structure of these com-pounds, it is clear that the simplest derivative is aetioporphorin.Now the decomposition of the colouring matter of the blood resultsin various end-products, such as phyllopyrrole, hzemopyrrole, andkryptopyrrole, and from a consideration of the structures of thesesubstances it appears most probable that the molecule of blood56 R. Willstiitter and L. Forsh, Annulen, 1913, 396, 180 ; A . , i, 499.57 R. Willstiitter and M. Fischer, Zeitsch. physiol. Chem., 1013, 87, 423 ; A . , i,1251ORGANIC CT-lEhflS’l’RY. 157pigment contains no less than four different pyrrole nuclei, whichare united together in a very peculiar manner; and it seems likelythat these four nuclei are also to be found in the aetioporphorinmolecule. Examination of the formula for aetioporphorin,C,,H,N,, shows that the number of hydrogen atoms is small whencompared with the number of carbon atoms in the molecule,whence i t may be deduced that the four pyrrole nuclei must beunited to each other in such a way as to leave only a few positionsfree for hydrogen atoms to occupy.IV. Kiister 58 has suggested a constitutional formula for hzminwhich takes this point into consideration, but as his formulacontains a sixteen-membered ring composed of four nitrogen andtwelve carbon atoms: it will hardly recommend itself to theordinary chemist unless no simpler structure can be suggestedwhich will give equally satisfactory results. 0. Piloty and E.Dormann59 have also put forward a suggestion as to the structureof the hzemin molecule, but according to R. Wilhtatter andM. Fischer this proposed formula will not account for the produc-tion of hzinatinic acid as a decomposition product of hzemin.have themselves brought forwarda formula which they believe to cover most of the field. Accordingto their view, aetioporphorin and aetiophyllin have the followingstructures :R. Willstatter and M. FischerCHZCHI I\\N N/c--;CH,*C*CHC,H,*C--C/ \C--CH I I\C----C/\NH NH/ ICH,*C-CH Eu,//c--c\N. I I‘\N--MP--N/ IC,H,*C=== (/ \C===C*C,H,\C(CH,):C*C H,CH:CHICH,* C:C( CH,)/Aetioporphoi in.I I‘c-c: tiIIC,H,*C--C/ \c‘---.- ’ -** c//c‘ H .cI-= C/ \C===C*C,H,CH,C C(t>H,)/ \C (C H3) : C* CH,Aetiophyllin.5* Zeitsch. physiol. Chem., 1912, 82, 463 ; A., i, 210.59 Annalen, 1912, 388, 313; A., 1912, i, 519.61 Ibbid.Zeitsch. physiol. Chem,, 1913, 87, 423 ; A . , i, 1251158 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.In these formulze the small number of hydrogen atoms in themolecules is accounted for by the introduction of the vinyl groupattached to a pyrrole ring. The position of this vinyl radicle hasbeen arbitrarily chosen, and the position of the two methyl groups,as well as one or two other points, are merely provisionally allotted.Assuming this formula for aetioporphorin, Willstatter and Fischerproceed to discuss the structure of hzemin itself. It appears fromtheir work that in the decomposition of the haemin molecule theelimination of the iron atom is not a direct process, but that, inthe first place, the hzemin molecule takes up two molecules ofhalogen acid, and that thereafter it can be freed from the iron.Until the addition of halogen acid has occurred, it appears to beimpossible to split off the iron atom from the rest of the complex.To account for this, it is assumed that the hzmin molecule containsa grouping similar to that which occurs in several of the alkaloids:I n this way, the following structures for haemin and hamopor-phorin are arrived a t :N--CH:CH/I \N-F*--N/ ICH,*CH=CHCO,H -c:H,*cH,-c===c/ \C=-=C CH,* C H,*CO,H ' C (CH,) : C-CH, CH,*C:C(CH,)/ blHwmin.CH:CHI ICH,-C*CHHsnioporph orinORGANIC CHEMISTRY. 159Residua$ A finity and Spatial ConjugntaorL.I n last year's report62 attention was drawn to the fact that in asix-membered dihetero-ring compound the nature of the atoms inthe 1 : $-positions had some influence on their reactivities. Furtherevidence on this point has come to light in a different field.63 Ithas been shown that tetranitromethane is capable of producingcolours when brought into the presence of compounds containingatoms which are capable of showing a rise in valency; thus, forexample, an aliphatic sulphide contains a bivalent sulphur atomwhich is capable of becoming quadrivalent, and such sulphideswhen mixed with tetranitromethane yield colours. A group ofsix-membered cyclic substances containing all permutations of twoatoms of sulphur, oxygen, and nitrogen in the 1 :4-position to eachother has been studied, and the following results have beenobserved. A single etheric oxygen yields with tetranitromethane apractically negligible tint (pentamethylene oxide), but when themore highly unsaturated sulphur and nitrogen atoms areemployed, the substances containing them (pentamethylenesulphide and methylpiperidine) show marked tints. Two ethericoxygen atoms in the 1 :$-position with regard to each otherare able to reiiiforco each other so as to produce a colour,although a very pale one. When two sulphur or two nitrogenatoms are substituted for the oxygen ones, the tints are verymarkedly deepened ; 1 : 4-dithian gives a lemon-yellow colour,whilst 1 : 4-dimethylpiperazine produces a brown tint. Thereappears t o be a relation between the depth of the colour and theamount of residual affinity on the conjugated atoms. Finally, theconjugation of a strongly basic atom, nitrogen, with a less basicone, oxygen or sulphur, produces a golden-yellow colour, whereasthe conjugation of two weakly basic atoms, oxygen and sulphur,yields the much less intense lemon-yellow tint. It appears thatthis reaction might form a rough gauge of the amount of residualaffiity on various atoms. A comparison of cyclic substances withthe corresponding open-chain compounds tends to show that theopening of the chain makes no very marked difference in the tintsproduced.A continuation of this investigation with the spectrograph 64 hasshown that in all cases an absorption band is present which has itshead at oscillation frequency 2800-2900, no matter whether thecompound treated with tetranitromethane be an amino-compound,Ann. Report, 1912, 163.63 H. T. Clarke, A. K. Macbetli, and A. W. Stewart, P., 1913, 29, 161.IA E. M. Harper and A. K. blacbeth, ibid., 304 ; see also C. I<. Tinkler, ibitl.,-278160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.a snlpliide, o r an ethylene derivative, so that the production ofthe band is evidently due to some perfectly general process, and isnot specially concerned with the particular atom involved. It hasalso been shown that th0 penetration of the band in most casesincreases if the solutions are kept, and in this way it is possibleto estimate the relative speeds with which two compounds reactwith tetranitromethane. The nature of the solvent used is also afactor in the problem. It appears not improbable that whenthis method is further developed it may furnish a very simplemeans of estimating the residual affinity of various compounds,and by a furbher extension i t may allow of the study of t hresidual affinity of the various solvents which can be utilised.Optictrl A ctivity in t 7 ~ e Heterocyclic Compounds.One or two points of interest have arisen during the year in thissection of the subject. Previous investigations have shown thepossibility of isolating optically active forms of compounds contain-ing quadrivalent sulphur or selenium atoms, and an attempt hasnow been made to resolve an oxonium derivative into its antipodici~ornerides.~~ Ths substance chosen as a starting material was2-phenyl-6-methyl-4-pyroneY which has the advantage that its hydro-chloride is not hydrolysed in aqueous solution. From the hydro-chloride the d-bromocamphorsulphonate was prepared in the usualmanner. It has the structure shown below, and the quadrivalentoxygen atom is an asymmetric one:CH=CPh HCO<CH:CDle>O<SO,.C,,ZI,,OBr *The resolution has not yet been carried out owing to lack ofsufficient material, but the results obtained up to the present pointt o the probability of success when experiments can be carried outwith larger quantities.A case in which stereoisomerism gives rise to a very large numberof isomeric compounds has been discovered among the tetrahydro-quinaldine derivatives.66 When d- and E-tetrahydroquinaldine arecondensed with d- and I-oxymethylenecamphor, four simple opticallyactive tetrahydroquinaldinomethylenecamphors are produced, anytwo of which can combine together with the formation of a stabledouble compound ; thus the complete series of derivatives includesthe four simple active, two fully racemic, and four partly racemiccompounds, ten in all.(Ic, S . I. Levy, E. J. Holmyard, and S. Ruliemann, P., 1913, 29, 159.titi TIT. J. Pope and J. Read, T., 1913, 103, 1515ORGANIC CHEMISTRY. 161The relation between optical activity and enantiomorphism ofmolecular structure has been very much in the forefront of stereo-chemical theory during the past few years, and the classic case ofthe diketodialkylpiperazines 67 should perhaps be dealt with inthis section of the Reports. As the paper in which it is treated,however, bears on the wider field of crystalline structure it seemsbest to let the whole subject be dealt with under one head, andthe reader is therefore referred to the Report on MineralogicalChemistry in this volume.A. W. STEWART.67 T. V. Barker and J. E. Marsh, T., 1913, 103, 837.REP.-VOL. X

ISSN:0365-6217    

DOI:10.1039/AR9131000054

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THIS report follows the same general plan as that of last year, butfewer papers have been selected for notice, and these have beenreferred to a t somewhat greater length. Consideration of the fewpapers dealing with water analysis is deferred until another year,when there may be more to record, but the physiological section,omitted last year, has been restored. The determination of waterin various materials has received an unusual amount of attentionrecently, and this subject has been selected for special notice.A new method has been found for the determination of hydroxyl-ion concentration, comparable to the method for determining theconcentration of hydrogen ions, which depends on the velocity ofhydrolysis of ethyl diazoacetate.1 It was announced last year thatit appeared probable that the decomposition of nitrosotriaceton-amine by aIkalis into phorone and nitrogen would afford a meansfor the quantitative determination of hydroxyl ions,2 and furtherresults which have been obtained leave no doubt that the viewexpressed in the first communication is correct.The velocityconstants have been established in presence of aqueous solutions ofsodium, potassium, and barium hydroxides, and found t o be pro-portional, not t o the concentration of the bases themselves, but t othe concentration of hydroxyl ions as deduced from conductivitymeasurements. The importance of the method lies in the fact thatthe effect of neutral salts in ordinary concentration is negligible.I n any individual experiment the values of the velocity constantagree to within 1-2 per cent., and the results are reproducible towithin 2-3 per cent.The method is consequently available withthis degree of accuracy for the estimation of the concentration ofhydroxyl ions up t o 0*05N, and the general formula may beexpressed as follows :Concentration of OH’= XtQ/R,G. Bredig and W. Fraenkel, Zeitsclr. Elektroclrem., 1S05, 11, 525 ; A., 1905, ii,692. D. A. Clibbens and F. Francis, T., 1912, 101, 2358.16ANALYTICAL CHEMISTRY, 163where a = 1-96 x 2*20c- 30, and KIP is the observed constant at the10temperature to. Between concentrations of 0.05iV and 0*3N, theunimolecular constants '' drift," and the method is consequentlyinapplicable within these limits.The drift ceases, however, a t thelatter concentration, and the method is once more applicable, butwith diminishing accuracy, up to about 1-4A7, beyond which pointthe velocity constants change so slightly with large increases in theconcentration of hydroxyl ions that a limit is set to the range ofthe method as a means of measuring such concentrations accur-ately.3It is nearly forty years since Lecoq de Boisbaudran described hismethod for producing arc spectra. Some of the advantages of themethod were immediately apparent, but the principle has foundless extended application than would have been the case had anysimple device for producing the arc been readily obtainable. Onemay search in vain for such device in any catalogue, and the!authors of a recent paper are probably right in stating that anapparatus devised by them represents the first attempt to bringthe method within reach of everyone.They establish an arcbetween the liquid t o be examined and an iridium needle, takingcurrent from an ordinary lighting circuit a t 100-200 voits throughan adjustable resistance. The length of the arc is adjustable bymeans of a micrometer screw, and the whole apparatus is mountedon a stand facilitating vertical and horizontal adjustment of theposition of the arc relative t o the spectrometer. No air linesappear, and the iridium electrode gives rise only to lines which arenegligibly faint. The hydrogen line, 656,up, appears as a brilliantline, the line 486pp as a bright, one. With this apparatus, not onlymay magnesium be detected in concentrations of 0.1 mg.per C.C.by means of the three brilliant lines 516.8 t o 518*4pp, but calcium,strontium, and psrticularly barium, can be detected in far lowerconcentrations than is the case when a Beckmann burner or othermeans f o r producing a flame spectrum is employed. I n the caseof barium, the concentration necesary to ensure detection is reducedfrom 14 mg. to 0.006 mg. per c.c., and in that of calcium from0.2 mg. to 0.002 "8.4Advance in the technique of handling minute quantities of solidsand liquids in a quantitative manner continues to depend mainlyon a single worker. During the year improvements have beenintroduced which greatly increase the accuracy of results dependingon the handling of minute precipitates. Precipitation is now con-y F.Francis and F. H. Geake, T., 1913, 103, 1722.4 E. H. Riesenfeld and G. Pfiitzer, Ber., 1913, 46, 3140 ; A , , ii, 1074.M 164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tluctecl in small platinum dislies, in wliicli tho substance t o bearialysed is weighed, dissolved, and precipitated. After filtratioiiof the liquid through the micro-filter previously described,5 the dishis dried and re-weighed, together with the dried filter, so that nopart of the precipitate which may adhere t o the dish escapesweighing. These dishes need to be 20 mm. or more in diameter,and must be very light in proportion to their size. Thin foil isseldom free from pinholes, and it is found that dishes of theminimum weight consistent with freedom from pinholes are bestmade from two or three disks of very thin foil welded together.Directions are given for cutting and welding the disks and shapingthem into basins.Quantities as small as 1 mg. can now be manipu-lated with an error not exceeding a few tenths of 1 per cent. It ispointed out that, now that such accuracy as this is attainable, theuse of micro-methods should not be restricted to cases where verysmall quantities of substance are available. By their means manydeterminations can be made more quickly than is possible whenworking on large quantities.6 From the same laboratory a quali-tative test for bismuth and manganese has been announced. It ismentioned here rather than in a later section of this report, as itsinterest lies less in the particular results so far attained than inthe nature of the reaction and its extraordinary sensitiveness.When a drop of a dilute solution of a salt of bismuth or manganeseis allowed to fall on a piece of pure chalk or gypsum, and this isheated in a hyzrogen flame, a brilliant blue (Bi) or bluish-green(Mn) luminescence is produced.One ten-millionth of a milligramof bismuth, or one millionth of a milligram of manganese will givethe reaction.?The determination of water has formed the subject of a numberof papers during the past three years. Some of these papers areimportant as recording the results of a critical investigation ofthe methods available €or the determination of water in a particularmaterial, but, because indexed under the name of that material,will have few readers.Nearly every recent paper on the subject,however, has this general interest, that it emphasises the fact thatthe exact determination of water, whether in minerals or in organicmaterials, is one of the most difficult problems presented t o theanalyst, and no problem presents itself more often to workers inevery branch of analytical chemistry. I n simple cases, the problemis essentially identical with that of obtaining a substance truly dry,a problem so difficult that the Paraday lecturer of 1911 expressedthe view that failure to solve it had been one of the two most fertileAim Keport, 1912, 196.J. Donan, Monutsh., 1913, 34, 553 ; A., ii, 424.5 lbid., 949 ; A ., ii, 743ANALYTICAL CHEMISTRY. 165sources of error in the determination of atomic weights.* Moreoften, however, the determination of water is complicated by thefact that it cannot be expelled from the material with which itis associated without bringing about other changes in the materialbesides loss of water.For the determination of water in silicate minerals and rocks, thethe well-known method of Penfield may give results far below thetruth, unless the tube be wrapped round with platinum as Penfielddirected, and the temperature raised t o such a point that theplatinum adheres to the glass. The fact that it requires no apparatusbeyond what is to be found in every laboratory will, however, causePenfield's method to be retained for service with the large numberof minerals and rocks which yield the whole of their water atmoderate temperatures.The Ludwig-Sipocz method, consisting inheating the powdered rock with fusion mixture in a currenl; ofdry air, and collecting and weighing the water, has been improvedby the use of a silica combustion tube with groirnd joints, andby the substitution of sodium carbonate for a mixture of sodiumand potassium carbonates. All silicate rocks yield to this method,which has the added advantage that the residue is immediatelyavailable for the determination of silica, alumina, etc. If thedetermination of water is the only object, this may be attained byheating the material alone in a silica tube, provided an electricfurnace capable of giving a temperature up to 1250O is available.Given the necessary apparatus, this is the best genera1 method,provided the water be collected and weighed, since it is applicableto all rocks except such as contain fluorides.The authors of thiswork publish results obtained with a large number of namedminerals and rocks, using the above methods and others. This isuseful as showing how far the elegant method of Penfield may stillbe retained for exact work, and also as showing the errors attachingt o all methods which determine " water " by difference.9Since the publication in 1895 of a Report on Coal Analysis by aCommittee of the American Chemical Society, much work has beencarried out with the object of improving methods for the deter-mination of moisture in coal, and this work is of general interest,as the problem does not differ in essentials from that of determiningmoisture in many organic materials which may lose other volatileconstituents or absorb oxygen a t temperatures a t or below looo.The Seventh International Congress of Applied Chemistry appointeda Committee to investigate and report on methods for the deter-s T.W. Ridiards, T., 1911, 99, 1201.hl. Dittrivh aud W. Eitcl, Ze'eitsclr. mory. C ' J L C ~ . , 1912, 75, 373 ; A., 1912, ii,804 ; ibid., 77, 365 : M. Dittrich, ibitl., 78, 191 ; A . , 1912, ii, 1207166 AXNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.mination of moisture in coal, and the more important conclusionsof this Committee have since been given wider publicity by beingincorporated in a paper with the general title, ‘‘ The determinationof moisture.” The reading of this paper was followed by that oftwo others dealing with the same general subject, with specialreference to foodstuffs. For the determination of moisture inorganic materials containing no other volatile constituents, dryingin a vacuum a t the ordinary temperature has some obvious advan-tages, but since the water on the surface of a fine powder has alower effective va.pour pressure than water per se, the rate of dryingin such a vacuum as can be obtained by the use of a water pumpis very slow.Even with a vacuum of 1 mm., twenty-four hours ormore is necessary. The International Committee suggests weighingsafter one, three, and six days. Such periods as this are probablyunnecessary, and, since a two-cylinder Fleuss pump will give avacuum of 0.01 mm., or less, it is possible that the use of such apump, together with an arrangement for circulating the sulphuricacid in the desiccator, might reduce the necessary period to one ortwo hours, an important consideration in technical work.It isto be noted that, in work of this kind, phosphoric oxide is notnearly so trustworthy a desiccating agent as concentrated sulphuricacid.When the material t o be examined contains other volatile con-stituents besides water, a direct method must be used. Heating ina current of dry air, with collection and weighing of the moisturecarried forward by the air current, is not admissible in the case ofcoal or of many other naturally occurring organic materials, becausethese material!, although not affected by mere heating to looo or alittle higher for prolonged periods, suffer change when exposed t oair a t looo or less, water being one of the products.Even a smallpercentage of oxygen in the gas used may lead t o serious error, andmany materials absorb carbon dioxide. Heating in a current ofpure, dry nitrogen, with collection and weighing of the waterevolved, is therefore indicated as the only direct method likelyt o prove of wide application. When skilfully conducted, it leaveslittle to be desired in point of accuracy, but requires for its accurateconduct more knowledge and care than is commonly supposed.Notwithstanding their undoubted merits, neither the vacuum northe direct method can be expected to come into general use fortechnical purposes, which require, however, some means for deter-mining moisture in organic materials with a close approximation t oaccuracy.Drying in an ordinary oven at about looo will no doubtcontinue t o be the most usual method of determining moisture iANALYTICAL CHEMISTRY.167organic materials other than those containing appreciable pro-portions of volatile substances other than water. Old as the methodis, i t has quite recently been found possible to effect a notableimprovement in the results which can be obtained by its means.Of its inherent sources of error, that due t o absorption of oxygenis now known to be the most important.That this is so in thecase of coal has long been known, but it has now been establishedas the chief source of error in drying the most widely variableorganic materials of natural origin. As the degree of oxidation isa function of the time of exposure t o air a t a high temperature,the analyst's aim must be to expel the moisture as quickly aspossible. Renewal of the air in the oven, as frequently as is possiblewithout material reduction of temperature, is one means ofadvancing this aim. Another lies in drying a t temperaturesslightly above instead of below looo. Experience has now accumu-lated to show that a very wide range of organic materials resemblecoal in not being appreciably more affected by exposure to air a t105-llOo than by exposure to air a t 99O, and since water is farmore quickly eliminated a t the higher temperature, the use of anoven heated to this temperature by toluene vapour or other meansshould become more general.10 Reference may fitly be given toone of the ovens recently described,ll which seems particularly welladapted for drying organic materials. It ensures a uniform tem-perature of the walls of the oven, and, by having the wall area largein proportion t o the cubic capacity, a fairly uniform temperature ofthe interior.An adequate supply of pre-heated air is also securedby chimney draught.The determination of water in petroleum and its products is aproblem of comparatively narrow interest, but a recent review often methods, all of which have found more or less extended usefor the purpose, together with the reasons which lead the authorsto prefer that depending on the volume of hydrogen evolved whenthe sample is treated with sodium, may perhaps be found usefulby chemists called on to discover the most accurate means ofdetermining water in some other organic liquids.12Only a few of the more recent papers on the determination ofwater are cited here, but these papers between them almost coverthe ground, and each gives references to earlier work.lo G.N. Huntly and J. H. Coste, J. Soc. Chew. Ind., 1913, 32, 62; F. H.l1 J. H. Coste, ibid., 1912, 31, 471 ; A . , 1912, ii, 678.l2 1. C. Allen and W. A. Jacobs, Eighth Int. Cong. App. Chem., 1912, X, 17.Campbell, ibicl., 6 7 ; W. P.Skertchly, ibid., 70 ; A . , ii, 237, 238168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Gas Analysis.I n 1910 Erdmann and Stoltzenberg showed that certain simplegas mixtures could be analysed with great exactness by applicationof the principle of fractional condensation by liquid air, etc. Theparticular gas mixtures investigated by these authors can be readilyanalysed by ordinary methods, but, in calling attention to theirwork, the reporter of 1910 suggested that the principle of theirmethod might find useful application in supplementing the ordinarymethods of gas analysis in difficult cases.13 Such an application isone recently described for the analysis of mixtures of hydrogen,methane, ethane, propane, and P-methylpropane. The mixture iesubjected to the temperature of liquid air, and the hydrogen andmethane are pumped off and then separately estimated in the usualmanner.14 The mixture is now allowed to attain a temperature of- 1 2 7 O and maintained a t this temperature by suitable means, andthe pump is once more set in operation.The whole of the ethanewith some propane is thus removed, and t)he mixture analysedeudiometrically, as is the residual mixture of propane and &methyl-propane after being allowed €0 attain the gaseous state.16The use of bromine or of fuming sulphuric acid to absorb olefinesis attended with great inconvenience, and a recent announcement,that ordinary concentrated sulphuric acid containing 1 per cent.of vanadium pentoxide serves equally well, will no doubt lead tothis elegant modification being tested in many laboratories.Absorption is rapid, the absorptive capacity of the reagent high,and so far as is known no gas which resists fuming sulphuric acidis attacked by the new reagent.A new reagent for absorbingacetylene and its homologues has also been described. It consistsof a solution of mercuric and potassium iodides containing a traceof alkali hydroxide, has an absorptive capacity of 20, and olefinesare no more soluble in it than in water.16A direct method, by which nitrogen in gas mixtures can beestimated with an error not exceeding 0.3 c.c., is worthy of notice,even although the somewhat elaborate apparatus it requires willprobably restrict its use t o cases where a direct estimation isspecially desirable.It depends on the fixation of the nitrogen ascalcium cyanamide, which is then submitted t o K jeldahl’s process.Like earlier investigators, its author finds that calcium cyanamideneeds rather special treatment in the early stages of the Kjeldahlprocess, but, given that treatment, i t does yield the whole of itsl4 P. Lebean and A. Daniiens, Conzpt. r e d , 1913, 156, 144, 325 ; A,, ii, 253.l3 P. Lebean and A. Damiens, BzcZZ. SOC. chinz., 1913, [iv], 13, 366.1’ Lebeau and A. Damiens, Compt. rend., 1913, 156, 557 ; A., ii, 349.Ann. Report, 1910, 160ANALYTICAL CHEMISTRY. 169nitrogen as a1nmonia.17 The apparatus required for the quantita-tive fixation of nitrogen as calcium cyanamide, although con,sistingof many parts and requiring time to assemble, could be improvisedfrom existing appa.ratus in almost any laboratory.18Inorgaizic Analysis.Qualitative.-A very delicate test for bromine depends on theviolet-blue colour which it imparts t o filter paper which has beendipped in Schiff's aldehyde reagent and then dried between otherpieces of filter paper.The colour is readily distinguished fromthat given by aldehydes, is not given o r influenced by thesimultaneous presence of iodine or chlorine, and will detect 0.01 mg.of potassium bromide when this is warmed with chromic acidsolution and a test paper exposed to the escaping vapours. Afraction of a milligram suffices for the detection, in a similarmanner, of bromine in an organic substance, and by operating onincreasing quantities of commercial iodides or chlorides until thereaction is given, the order of magnitude of their bromine contentcan be determined.19 The procedure is simpler than that recom-mended by Denigks, who has since devised a very similar test.20Although less sensitive than the diphenylamine reaction, a newtest for the detection of nitrate in presence of nitrite is deservingof reference, because it is available in presence of ferric salts.Itdepends on the blue colour which traces of nitric acid impart to asolution of quadrivalent iridium in concentrated sulphuric acid, andwill detect 0.1 mg. of nitrate in the presence of 1 gram of nitrite.21Reynoso's method for the separation of phosphoric acid in thecourse of qualitative analysis, by boiling the nitric acid solutionwith tin, requires considerable experience for its successful conduct.Since it was recognised that the method depended on the adsorptionof phosphoric acid by metastannic acid, however, there was reasonto hope that some modification of it might be evolved which couldbe applied with confidence by any chemist in any ordinary circum-stances.22 Such a modification has now been described, the methodconsisting in boiling the nitric acid solution with a considerablequantity of metastannic acid gel, prepared in a particular manner.Less than 0.1 per cent.of the phosphoric acid present finds itsl7 Ann. Beport, 1911, 178.l8 €3. Natus, Zcitsch. nnaZ. Chem., 1913, 52, 265; A . , ii, 527.I. Guareschi, Atti R.Accad. Sci. Torino, 1912, 47, 696, 988 ; A., 1912, ii,989 ; ibid., 1913, 48, 4 ; Zeitsch. anal. Chela., 1913, 52, 607 ; A., ii, 333.2" G . Denigds, Compt. rend., 1912, 155, 721; A . , 1912, ii, 1208.21 V. N. Ivanov, J. h'iws. Plhys. Chem. Soc., 1912, 44, 17'72 ; C'Jimi. Z p i f , , 191.3.37, 157 ; A., ii, 149.W, Mecklenburg, Zeitsch. anorg. Chem., 1912, 74, 215170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.way into the filtrate, and no tin passes into solution unless chloridesare present. Iron, titanium, and zirconium are wholly retainedby the gel, portions of which may be tested directly for the presenceof iron and titanium.=To be of real service in the analysis of zinc ores, a test forcadmium must be roughly quantitative. The test devised someyears ago by Biewend, depending on reduction in a narrow glasstube with subsequent conversion of the sublimate into sulphide,makes it possible to estimate 0.01 per cent.of cadmium with nogreater error than attaches t o an estimation of arsenic by theMarsh-Berzelius method, which this test somewhat resembles.24Biewend’s test, however, requires some time, and in many cases allt h a t is required is to know whether there is less than some assignedamount of cadmium, such as 0.1 per cent., present. A test has nowbeen devised which can be blunted to this or any desired extent,by varying the amount of material taken, which only requires afew minutes t o carry out, and serves for the approximate estimationof heavier traces than those it is desired t o detect.It depends onthe production of a sublimate of cadmium oxide on porcelain.25A paper on the qualitative analysis of the zinc group is a goodexample of the work being done by American chemists to putqualitative analysis on a better basis. Other people may writetext-books or devise supersensitive tests, but Americans wantmethods of which it can be said with certainty that they will detect1 mg. in a sample of a certain size and fail t o detect some smallerassigned amount, and, so far as we possess such methods, we owethem largely t o American workers. It is not uncommon to hearAmerican methods spoken of with impatience, because such methodsinvolve the frequent use of measured quantities of reagents, butthis paper abundantly justifies the rough measurements required,and shows that such measurements are but part of the Americanmethod, which often requires, as in this case, the invention ofentirely new methods of separation. A scheme of analysis whichwill detect with certainty 0.5 mg.of zinc, manganese, nickel, orcobalt in presence of large quantities of any of the others will proveof considerable practical value to many.26Quantitutiue.-As the decomposition of silicates is often thefirst step in quantitative analysis, the first reference under thisheading may fitly be t o a paper which deals with the use of bariumcarbonate for decomposing silicates. One advantage of the method23 W. Mecklenbnrg, Zeitsch. anal. Chem.. 1913, 52, 293 ; A., ii, 529.24 R. Biewend, Berg.-Huttenm.Zeit., 1902, 61, 401 ; A . , 1903, ii, 105.25 F. C. Breyer, Eighth h t e r . Cwng. App. Chem., 1912, xxv, 1 ; A . , ii, 793.46 R. E. Lee, R. H. Uhlinger, and F. 0. Amon, J. Amer. Chew. floc., 1913, 34566 ; A., ii, 530ANALYTICAL CHEMISTRY. 171is the ease with which barium can subsequently be eliminated;another, the fact that a crucible weighing only 4 grams suffices forthe decomposition of 1 gram of felspar and the like. A temperatureof 1350O is required, but this is readily attained by means of theelectric furnaces now procurable, and the author has designed aspecial furnace by means of which a small crucible, such as sufficesfor this method, may be raised t o the requisite temperature by ablowpipe flame.27It is found that hydrogen peroxide can be determined iodometri-cally if molybdic acid is employed as catalyst.Molybdic acid isone hundred times as effective as iron salts, and has the furtheradvantage that i t appears to have no accelerating effect on thereaction between potassium iodide and atmospheric oxygen. By anextension of the method, hydrogen peroxide and ozone can beestimated in presence of each other.28Selenic acid is capable of reacting with bromides and chlorides,with liberation of the halogen and formation of selenious acid, butthe reaction in either case is a reversible one. Researches directedt o determining the conditions under which the reaction withbromide is approximately quantitative, and that with chloridealmost wholly inhibited, have been so far successful that a newmethod for the estimation of bromide in presence of chloride hasbeen based on the results obtained.29 As selenic acid obtained bythe usual methods is apt to retain impurities which interfere withits use for the above purpose, reference may be made t o a methodby which i t may readily be obtained of a satisfactory degree ofpurity.30An entirely new and very accurate method for the estimation offluorine has been described.It depends on the fact that, whensufficient ferric chloride is added to a neutral solution of an alkalifluoride the whole of the fluorine separates as a white, insolublefluoride of the type Na,FeF,. The end-point of a simple titrationwith thiocyanate as indicator is not easily seen, but when theslight solubility of the precipitate is still further repressed by alarge addition of chloride, and some ether and alcohol are alsoadded, the characteristic red colour makes its appearance in theethereal layer with such sharpness that the method is nearly asaccurate as a volumetric method can be.I n combination with acidi-metric methods it greatly simplifies the analysis of commercial27 W-. Hempel, Zeitsch. anal. Chem., 1913, 52, 86 ; A , , ii, 244.28 V. Rothmund and A. Rnrgstrtller, Monntsh., 1913, 34, 693 ; A . , ii, 524.2g F. A. Gooch and P. L. 13lumentha1, Zeitsch. aizorg. Chewz., 1913, 80, 161 ;30 P. L. P,liunenthsl, ibid., 246 ; .I., ii, 148.A., ii, 148172 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sodium fluoride, which usually contains sodium hydrogen fluorideand sodium silicofluoride.31When a nitrite is added to an acid solution of thiocarbamide thereaction may proceed in two directions, depending on the strengthof the acid; thus in presence of acetic acid the reaction takes placemainly in accordance with the equation:CSN,H, + HNO, = HSCN + N, + 2H,O,whilst in the presence of hydrochloric acid the reaction2CSN,H4 + 2HN02= C28,N,H6 + 2N0 + 2n20predominates.Since the volume of gas produced by a definiteweight of nitrous acid is the same whichever course ths reactiontakes, the fact that neither reaction can be wholly repressed is ofno importance so far as the gasometric determination of nitritesis concerned. A gasometric method based on these observationsgives exact results with silver nitrite, is shown t o be accurate inpresence of ten times as much nitrate as nitrite, and, so far as itgives results in disagreement with those obtained by the carbamidemethod, as it does with certain commercial preparations, is probablyto be preferred to that method.32Feld’s original method for the estimation of polythionate inpresence of thiosulphate and free sulphurous acid gives satisfactoryresults when the amount of sulphur dioxide in the solution issmall,33 but when much sulphur dioxide is present a large part ofit may escape before oxidation is complete.A modification of themethod has now been described which is free from this objection.It depends cn the fixation of sulphur dioxide as manganous thio-sulphate by treatment with excess of rnanganous sulphide; onsubsequent treatment with mercuric chloride the manganous thio-sulphate liberates hydrochloric acid 34 in accordance with the nowwell-known equation of Feld, on which his method for the estima-tion of thiosulphate is based.This method also has come underreview during the year, and it is pointed out that, in presence ofexcess of mercuric chloride, a solution of a bisulphik?, previouslyneutral to methyl-orange, reacts acid towards that indicator, andcontinues to do so until sufficient alkali is added to convert thewhole of the bisulphite into normal sulphite. Consequently, Feld’smethod for the estimation of thiosulphate must fail in presence ofsulphites or bisulphites. A simple modification of the method,however, meets the caee, and the above observations have beenmade the basis of a method for the analysis of mixtures of normal31 A.Grecff, Bw., 1913, 46, 2511 ; A., ii, 975.32 ilks 1\1. E. C‘ostlr and E. A. Werner, T., 1913, 103, 1039.33 W. Feld, Zeitsch. nngrzr. Chcm., 1911, 24, 290 ; A.,1911, ii 28934 W. Fold, ibid., 1913, 26, 286 ; d., ii, 617ANALYTICAL CHEM1S’IHY4 173and acid sulphite which is far more satisfactory than methodsdepending on the use of phenolphthalein.35 Another method forthe analysis of mixtures of thiosulphate with normal and acidsulphite depends on the use of hydrogen peroxide in place of Feld’smercuric chloride.36 The methods available for the estimation ofhyposulphites have been subjected to a critical review, the limits ofaccuracy of methods depending on the reduction of mercuricchloride--useful for technical purposes-have been established, andtwo other methods are shown to be exact, except in presence oflarge quantities of bisulphite, when the error may reach 0.3 p0rcen t.37One ofthem calls attention to the fact that Volhard’s method gives resultsthat may be 0.4 per cent.too high, due to adsorption of ammoniumthiocyanate by silver thiocyanate, and shows how the error due tothis came may be reduced to negligible proportions.38 The otherpaper, issuing from the United States Mint, shows that, even underthe favourable conditions of a mint laboratory, two =sayers, work-ing on identical samples of standard silver and making four estima-tions each by Gay Lussac’s method, may differ as much as 1 finein their reports.Nevertheless, the method is preferred to fire assayfor mint work. It is useless for a person who uses i t only occasion-ally to expect to attain high accuracy with it without spendingmore time on a determination than is warranted in a busy com-mercial laboratory.39Although there is a choice of good methods for the estimation ofcopper, the empirical method of Guess must have been foundspecially convenient in certain circumstances, or it would not havefound its way into textbooks such as Low’s “Technical Methods ofOre Analysis,” which ignores redundant. methods. The methoddepends on the precipitation of copper as thiocyanate, which isdecomposed on the filter by means of sodium hydroxide, and theresulting solution of sodium thiocyanate is acidified and titratedwith permanganate.Under the conditions prescribed by Guess, thereaction between thiocyanate and permanganate does not proceedquantitatively, and i t has been usual for each operator to determineand apply an empirical factor.40 Although the original methodgave satisfact’ory results in experienced hands, a recent modifica-tion, which ensures a quantitative reaction between thiocyanate andTwo papers on the estimation of silver deserve a word.35 E. Bosshard and W. Grub, Chein. Zgit., 1913, 37, 465 ; A . , ii, 525.37 E. Boshhard and W. Grob, ibid., 423, 437 ; A, ii, 428.A. A. Besson, ibid., 926 ; A . , ii, 874.V. N. Ivanov, J. Russ.Phys. Chem. SOC., 1913, 45, 66 ; A, ii, 340.P. P. Dewey, J. 2nd. Ezg. Chenz., 1913, 5, 209 ; A, ii, 340.H. Grossiiiann and L. Hdter, Chem. Zeit., 1909, 33, 348 ; A , , 1909, ii, 449174 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.perinanganate, is more likely to be of general use.*1 A recentpaper42 on the estimation of cadmium is valuable, not only becausethree good methods are described in detail, but because the specialcircumstances in which one or other is to be preferred are plainlyindicated. The clioice of method is generally determined by theamount of cadmium present, and by the ratio of this amount tothat of zinc.The titration of antimony by permanganate in sulphuric solutionfree from hydrochloric acid is the only novel feature in a recentscheme for the analysis of white metals, but the scheme as a wholeis deserving of attention because of the speed with which ananalysis can be completed with sufficient accuracy for manypurposes.43 Accurate and rapid methods are now available for thedetermination of tin in ores and alloys, but a method dependingon titration with potassium bromate may be referred to.Althoughnot published before, the method has been in use for some timein silk-works, where the fact that i t is available in the presence ofphosphates is an advantage.l4 The separation of antimony fromtin is referred to under (‘ Electrochemical Analysis.”It has been shown that all the methods generally recommendedfor the estimation of free acid or free base in commercial aluminiumsulphate give inaccurate results, the only method described inLunge’s “ Technical Methods ” actually discovering 0.25 per cent.free acid in each of a number of samples ranging from neutral tostrongly basic. An exact method has now been devised, dependingon the fact that neutral salts of aluminium are precipitated onwarming with potmsium ferr~cyanide.~bA recent method for the estimation of zinc involves the applica-tion t o an analytical problem of the mutual precipitation of twocolloids.The particular colloid selected to assist the precipitationof zinc sulphide is sulphur, sodium hydrogen sulphite being addedto the chloroacetic acid solution of zinc, through which hydrogensulphide is then passed. The paper includes some useful informa-tion on the ignition of zinc sulphide precipitates.46Attention may be called to a careful study of the sources oferror in the assay of platinum, which is foilowed by the descriptionof a metbod stated to give results correct to 1 part in 1000.47M7.D. Treadwell and K. S. Guiterman, Zeitsch. anal. Chem., 1913, 52, 459 ;41 D. J. Demore3t, J. Ind. Eng. Chem., 1913, 5 , 215 ; A., ii, 341.A., ii, 728.43 D. J. Demorest, J. Iyzd. Eng. Chem., 1913, 5, 842; A., ii, 982.45 V. N. Ivanov, J. BUSS. Phys. Chem. h’oc., 1913, 45, 57; Chem. Zeit., 1913, 37,46 I<. Bornemann, Z~ilsch. anorg. Chenz., 1913, 82, 216 ; A . , ii, i 2 7 .47 L. S. Rtiner, Oesterr. Zeitsch. Bcrg..u. Hidttenw., 1913, 61, 141, 155.F. Fichter and E. 3liiller, Chem. Zeit., 1913, 37, 309; A., ii, 347.805; A., ii, 1078ANALSTICAL CHEMISTRY.175Palladium may be separated from any of the other platinum metalsby precipitation with a-nitroso-&naphthol. The precipitate isvoluminous and coloured, and the reaction therefore serves for thedetection of very small quantities of palladium.48A t least two exact methods are now available for the determina-tion of vanadium in special steels which may also contain titanium,molybdenum, and large quantities of chromiurn.49 As these methods,however, are necessarily complicated, attention may be directed toa simpler one which meets the very common case where titaniumand molybdenum are absent and chromium is only a minor con-~tituent.5~ I n 1908, Fenton showed that dihydroxymaleic acid wasa far more sensitive reagent for titanium than hydrogen peroxide,and had the further advantage t h a t vanadium did not interfere.51Other very sensitive reagents for titanium have since beenannounced,pz and Fenton’s work received no attention until lately,when it was found that a combination of the peroxide test andFenton’s test afforded a very satisfactory method for the simul-taneous estimation of titanium and vanadium, especially in sili-cates.53 Weiss and Landecker’s method for the separation ofcolumbium and tantalum, even as modified by Hauser and Lewite,54seems dependent on.conditions not yet defined, for i t has againbeen subjected to adverse criticism. I t s latest critics revert to themethod of separation which depends on the insolubility ofpotassium tantalum fluoride and the solubility of the correspondingcolumbium compound.This method has not been without itscritics, but important modifications have been introduced which aresaid to make the precipitation of tantalum quantitative, whilst asingle re-precipitation suffices t o free it from columbium.55 Theprecipitates were tested for columbium by a new colorimetricmethod, which, unlike the gallotannic acid method, is not affectedby the presence of tantalum, and serves for the estimation of0.1 per cent’. of columbium with an error not exceeding 5 percent.56Among papers dealing with the determination of the non-metallicconstituenh of commercial metals and alloys, the following maybe mentioned. It has been shown that any oxygen in brass prob-ably exists as zinc oxide, and therefore cannot be determined byW.Schmidt, Zeitsch. an om^. Chem., 1913, 80, 335 ; A., ii, 440.C. R. blcCabe, J. Ind. Evg. Cl~em., 1913, 5, 736 ; A., ii, 987.49 Ann. Report, 1912, 208.R1 Z’., 1908, 93, 1064. 52 Ann. Beport, 1912, 209.%‘j J. W. Mellor, Traits. Eny. Cermn. SOC., 1912-13, 12, 33 ; A , , ii, 627.55 E. Meimberg and P. Winzer, Zeitsch. angew. Chem., 1913,26, 157 ; A., ii, 348.56 E. IlleimGrrg, ibid,, 83 ; A . , ii, 251.Am. Beport, 1912, 208176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the methods adopted for determining oxygen in copper; foralthough the zinc oxide is reduced by hydrogen at a high tempera-ture, in the cooler portion of the combustion tube the reversereaction O C C U ~ S .~ ~ It has since been found that reduction in carbonmonoxide is successful except in presence of tin or nickel.58 Arecent method €or the determination of carbon in steel dependson direct dry combustion and measurement of the carbon dioxideproduced. It involves the use of costly and complicated apparatus,which is justified, however, by the ease and speed with whichresults of the highest accuracy may be attained by means of it.59Another method, almost equally quick, also depends on combustionin a limited supply of oxygen, followed in this case by absorptionof the carbon dioxide in a definite volume of N/lO-alkali hydroxide,the excess of which is then determined by titration with acid andphenolphthalein.60 For the estimation of phosphorus in vanadiumsteels three new methods have been proposed.One depends on tb0separation of phosphorus from vanadium by precipitation asaluminium phosphate under closely defined conditions 61 ; anotherdepends similarly on separation as cerium phosphate,62 the separa-tion in either caae being but a preliminary to a phosphorus debr-mination by the molybdate method. The third method dependson the fact that, if vanadium compounds are reduced to the quadri-valent condition and means taken to prevent their re-oxidation,the precipitation of phosphoric acid as phosphomolybdate is com-plete, and the precipitate is uncontaminated by vanadiumcompounds.63 It is stated that methods for the estimation ofphosphorus in tungsten-bearing materials which start with an alkalifusion lead to the loss of at least two-thirds of the phosphorus.Methods suitable for use with every class of tungsten-bearingmaterial, all of them methods involving prolonged treatment withacid, are described.64Electrochemicnl Ancrlysis.Although the number of papers dealing with electrochemicalanalysis shows no falling off, there have been few striking develop-ments this year.It is found that certain reducing agents increase57 T. Turner, J. Inst. Metals, 1912, 8, 248 ; A . , ii, 148.58 T. West, ibid., 1913.‘j0 H. cie Nolly, Chein. Engiiicer, 1913, 18, 30.E. Szhsz, Zeitsch. nngew. Chcnz., 1913, 26, 281, ; A., ii, 621.C. F. Sidener and P. M. Skartvedt, J. I d Eng. Cheni , 1923, 5, 838 ; A., ii,979.62 E.W. Haginxier, Jlet. and Chem. Eitg., 1913, 11, 28.m J. R. Cain and F. H. Tncker, J. In4 Eng. CIae?n., 1913, 5, 647 ; A . , ii, 875.64 C. M. Johnson, ibid., 297 ; A,, ii, 529ANALYTICAL CHEMISTRY 177the oxidisiilg potential of the dichromate ion on platinum byamounts up to 0.2 volt. No other oxidising agent tried exhibitsa similar effect. The potential increases up to the very end pointof the reaction, and is highest when the dichromate concentrationis least. A final drop of N/lO-reducing agent often depresses thepotential by 0.5 volt. These observations have suggested animprovement in the electrometric method of titrating dichromateand ferrous salts, which makes i t both more rapid and moreaccurate than the ferricyanide method.65 Hitherto lead has beenestimated electrolytically only as peroxide on the anode.Condi-tions haLve now been determined under which it may be depositedquantitatively as metal on the cathode. Neither zinc, cadmium,iron, nickel, cobalt, nor manganese interferes, but copper, ifpresent, is wholly deposited with the lead, whilst tin and antimonyare incompletely deposited, and must therefore be absent.a Theexcellent method for antimony depending on its deposition froman electrolyte of sodium sulphide, potassium cyanide, and sodiumhydroxide, is not available for the simultaneous deposition of tinand antimony, as tin is incompletely deposited from a sodiumsulphide electrolyte. Similarly, the equally good method for tin,depending on deposition from the solution of its sulphide inammonium polysulphide, as usually carried out, breaks down whenantimony is present, since metallic antimony is appreciably solublein ammonium sulphide.If, however, this second method be somodified that, towards the end of the electrolysis, the concentrationof ammonia and ammonium sulphide becomes negligible, the deposi-tion of antimony is quantitative. These conditions can be securedby electrolysing at boiling temperature, the ammonia and ammon-ium sulphide being expelled or oxidised to ammonium sulphate.The simultaneous deposition of tin and antimony is thus madeeasy. The separation of antimony from tin is a more difficultproblem, but a method depending on precipitation of the tin asstannic hydroxide and electro-deposition of the antimony from asolution of calcium sulphide is capable of good results if somewhatcumbersome.67 A method for the separation of copper fromtungsten, which avoids the use of potassium cyanide, has beendescribed, and a modification of it is possibly the first exactmethod for the electrolytic separation of copper from molyb-denum.6865 G.S, Forbes and E. P. Bartlett, J. A?ncr. Chm. Xoc., 1913, 35, 1527 ; A , , ii,86 R. Gartenmeister, Che7n. Zeit., 1913, 37, 1281 ; A., ii, 1075.67 N. K. Chaney, J. Amer. Chem. Xoc., 1913, 35, 1482 ; A . , ii, 987.6* W. D. Treadwell, Zeifsch. El~krrochena., 1913, 19, 219 ; A , , ii, 342.984.REP.-VOT,. X. 178 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Orgn?iic A ncrlysis.One qualitative reaction of general interest has been the subjectof an important paper this year.It has been shown that thereaction between ferric chloride and alkali ferrocyanide is a time-reaction, which is retarded by high acid and saline concentrations.When testing for ferrocyanide in very dilute solutions, ferroussulphate is a far more sensitive reagent. The pale colour of theferrous solution allows the use of a large excess, which tends tocarry the reaction to completion, and there is usually enoughdissolved oxygen in the water to oxidise the ferrous ferrocyanidet o Prussian blue, sot that, with only traces of ferrocyanide present,the maximum intensity of colour is obtained instantaneously.69It is known that the presence of water-vapour materially assiststhe combustion of difficultly combustible substances.The principlehas now been applied with success to the estimation of carbon inorganic substances, as well as in steel. Lower temperatures arenecessary, and the method is especially useful in the analysis ofexplosive compounds and substances which form hard masses ofcarbon. Nitrogenous compounds, such as glycine, alanine, hippuricacid, aad carbazole, may be burnt completely at comparativelylow temperatures, without the necessity of mixing copper oxidewith the substance in the boat.70 Cerium dioxide distributed onasbestos is found to be an effective substitute for the platinisedasbestos of Dennstedt. In addition to its cheapness, the catalysthas the further merit that it is not poisoned by arsenic or leadperoxide.Its sole disadvantage, as compared with platinum, limin the fact that i t retains an amount of sulphur which varieswith the temperature of combustion, so that sulphur cannot bedetermined simultaneously with carbon, hydrogen, and halogens.71A direct method f o r the estimation of oxygen in organic compoundshas been described. It depends on the fact that when an organicsubstance is heated in pure hydrogen and the products of thereaction are passed over charcoal a t a white heat,the whole of theoxygen in the original compound is converted into water, carbondioxide, and carbon monoxide. The water and carbon dioxide areabsorbed in the usual manner, and the carbon monoxide isestimated by passing the residual gas through iodine pentoxideand absorbing the resulting carbon dioxide in soda-lime.72Many substances when submitted t o Zeisel's process for the deter-mination of methoxyl groups fail to give satisfactory results unlessD.Vorlander, Ber., 1913, 46, 181 ; A . , ii, 257.S. Hilpert, ibid., 949 ; A . , ii, 432.i1 J. Bekk, ibid., 2574; A., ii, 981.i2 Af. C. Roswell, J. Anzer. Cheni. Sot., 1913, 35, 284 ; A., ii, 334ANALYTICAL CHEMISTRP. 179heated with fuming hydriodic acid for several hours, in some casesiiiore than twelve hours. The addition of acetic anhydride, assuggested by Herzig, effects an improvement in some cases, but notin all, and, as Herzig pointed out, the presence of a methoxy-and not a methylimino-group is only indicated with certainty whenthe theoretical quantity of methyl iodide is liberated in the normaltime of one and %half hours.73 It is now found that, in most ofthese difficult cases, hydriodic acid of D 1.7 effects complete reduc-tion in the normal time, provided a little phenol is present.Tetra-methylellagic acid, the anomalous behaviour of which led Herzigt o attempi the improvement of Zeisel’s method, only yields tofuming acid even in presence of phenol, but with the exceptionof methyl nitroanisate, no substance tested has required morethan one and a-half hours.74 Reference may be made to avolumetric modification of Zeisel’s method, based on decompo&ionof the alkyl iodide by heat and titration of the iodine thusproduced. Account is taken of the fact that a little hydriodic acidis formed at the same time, and the method is sufficiently exact,but i t is scarcely simple enough to displace the original method.75Some years ago it was proposed to estimate carboxyl groups bymeasurement of the hydrogen sulphide which is evolved when evenweak organic acids are brought into contact with a solution ofpotassium hydrogen sulphide saturated with hydrogen sulphide.The method has the advantage over the titration method that mostlactones and alcohols, and phenols as such, are without effect, butwith the apparatus hitherto in use, only roughly approximateresults could be obtained.76 Apparatus has now been devised whichavoids every source of error that can be avoided. Of the remainingerrors one is constant and positive, whilst the other is negative andvariable in amount, according as the acid is mono- or di-basic.With dibasic acids, the errors nearly balance each other, but mono-basic acids are consistently underestimated by 2.1 to 2-4 per cent.77Since iodoform and carbon tetraiodide contain 96.7 and 97.7per cent.respectively of iodine, the gravimetric determination ofone of these compounds in presence of the other is practicallyimpossible. This fact lends importance to a recent proposal foreffecting the determination by a gasometric method. The methoddepends on the fact that 1 gram of iodoform yields 56.6 C.C. of gaswhen treated with silver nitrate solution, whereas 1 gram of the73 J. Herzig, Mnnatsk., 1908, 29, 295 ; A., 1F08, ii, 638.7-l F.Weishut, ibid., 1912, 33, 1165; A., ii, 78.75 A. Klemenc, ibid., 1913, 34, 901 ; A., ii, 733.i6 F. Fiichs, ibid., 1888, 9, 1132, 1143 ; 1890, 11, 363; A . , 1889, 463.77 W. H. Hunter and J. I). Edwards, J. Antcr. Chem. Xoc., 1913, 35, 452 ; A . , ii,535.N : 180 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tetraiodide only yields 42.9 C.C. The reactions are different,iodoform yielding carbon monoxide and silver iodide quantitatively,whereas the tetraiodide gives rise t o carbon monoxide, carbondioxide, silver iodide, and silver iodate, in proportions which varywith the experimental conditions, Clearly, however, this gaso-metric method is independent of the exact course of the reaction,provided, as is the case, all the carbon appears either as carbonmonoxide or dioxide.78Reference was made last year t o a method for the estimation ofmalic acid depending on the increase in rotation produced bytreating the solution with uranyl acetate.79 Since the specificrotation of d-tartaric acid is also increased by uranyl salts, themethod is not available in the frequent cases where malic andtartaric acids are present together.A method has now been devisedfor estimating both acids in the same solution, which is based onthe facts that the rotation of each is increased independently ofthe other by treatment with uranyl acetate under defined con-ditions, and that both acids can be oxidised quantitatively t o oxalicacid by heating with alkaline permanganate. I n the absence ofother substances which yield oxalic acid on oxidation and cannotbe removed before treatment with permanganate, the method givesexcellent results.80 Another recent method for the separateestimation of tartaric, malic, and succinic acids when occurringtogether depends on the fact that, under certain defined conditions(faint acidity and relatively low concentration of alcohol), all threeacids are precipitated by lanthanum nitrate, whereas other condi-tions, also closely defined, determine the precipitation of tartaricacid aIone, or of tartaric and malic acids.The method is volu-metric, a standard solution of lanthanum nitrate being used andthe end-point d’etermined electrometrically.81A third method for the estimation of tartaric and malic (andcitric) acids when occurring together introduces no new principle,but combines some older methods with Kling’s method for theestimation of tartaric acid.This method is available in presenceof succinic acid.82 Since it became recognised that precipitation astricalcium citrate does not afford a trustworthy means of estimatingcitric acid, a method proposed some years ago by Denigh hasattracted attention. This method depends on oxidation of thecitric acid to acetonedicarboxylic acid, which is then precipitated73 M. Lantenois, Compt. rcnd., 1913, 156, 1629 ; A., i, 696.ig Ann. Report, 1912, 213.*O P. B. Dunbar, Eighth Inter. Cony. App. Chem., 1912, XXVI, 375 ; A., ii, 802.81 P. Dutoit and M. Duboux, Bull. SOC. ehim., 1913, [iv], 13, 832 ; A., ii, 888.82 L.Mathieu and L. Ferre, Bu2l. Assoc. Chinz. Swr. et Dist., 1913, 30, 842 ;Ann. Chim. ma?., 1913, 18, 352; A., ii, 990ANALYTICAL CHEMISTRY. 181as ail insoluble mercury compound. At least three authors havereported adversely on it, but a volumetric modification of it, dueto Beau, one of its earliest critics, is beginning to find its way intotext-books. Within the year, Beau’s modification has been shownto be quite untrustworthy, but a t the same time a satisfactorymethod-not differing in principle from that of Denigks-has beena t last devised. Malic, lactic, and salicylic acids interfere, butaccurate results are obtained in presence of tartaric, succinic, oxalic,benzoic, acetic, phosphoric, and sulphuric acids.83A recent study of the effect of temperature, acid concentration,and time on the bromina.tion of phenol has made i t possible toestimate phenol with an error not exceeding 0.05 mg., and has alsoshortened the time necessary t o make a determination, and shownthat the large excess of reagents commonly used and supposed tobe necessary may be decreased with advantage.84 The authors ofthis work have also published a description of a method by whichi t is claimed that, in a mixture of phenol and the three cresols, thephenol, the m-cresol, and the sum cf the o- and pcresols can becalculated from the results of a single titration with iodine, pro-vided that no other substance which reacts with iodine is present,and that if any other substance is present, the total content ofphenols is known.The method is said to be accurate to within0.2 per csnt. for each constituent, but the published data do notbear out this claim. This is probably due t o typographical errors,of which there are many obvious examples elsewhere in the paper,and it is t o be hoped that the authcrs will publish some furthernotes on the method, which may be useful. This must depend tosome extent on the time occupied in solving five simultaneousequations, a point which would be made more clear by a workedexample.85A recent paper on the estimation of some organic substances(mainly phenols and derivativss of phenols) from their consumptionof alkaline permanganate86 recalls three papers of wider scope byRetper. The limitations of methods depending on the use ofpermanganate are obvious, but not only do they serve for theestimation of many substances in pure aqueous solution, but theyhave helped to solve some difficult problems, such as the separateestimation of citric, tartaric, and malic acids when occurringtogether.I n any future attempt to make use of permanganate incomplex cases like these, much time might be saved by reference t o8: L. Gowing-Scopes, Analyst, 1913, 38, 12 ; A., ii, 162..s+ 1, V. Redman, A. J. Wcitli, arid F. P. Brock, J. I~UZ, Eizg. CJwm., 1913, 5,389 : A . , ii, 632./bid., 831 ; A., ii, 988.86 C. 11. Pence, ibid., 218 ; A . , ii, 850182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Hetper’s work, which not only covered a large number of organicsubstances, but was systematic, and therefore suggests the probablebehaviour of many substances not actually tried.87A paper by Ogilvie, on the use of invertase instead of acid forhydrolysing sucrose in commercial products when carrying out theClerget method, was briefly referred to in the report for 1910.88 Bytaking advantage of a recent proposal of Pellet’s for improving theordinary Clerget process, Ogilvie improved on the invertase processof Ling and Baker, who were the first to indicate the possible valueof inversion with invertase in the analysis of low grade products ofthe sugar factory, and described experiments which confirmed theview of these authors that invertase is a selective hydrolyst, invert-ing only the sucrose (and raffinose if present) without a t all affectingthe non-sugar substances.A t the same time i t was shown thatAndrlik’s modification of the ordinary Clerget process gave resultsidentical with those obtained by the invertase method, as didPellet’s sulphurous acid process, which is more convenient, whereasthe ordinary Clerget-fierzfeld process gave results with beetmolasses which were from 0.5 t o 1.5 per cent. too low.89 Theinvestigation has now been extended to cane molasses, which yieldidentical results, whether examined by the invertase method or bythe methods of Andrlik or Pellet, but render results which are from0.4 to 1.3 per cent. too high when submitted to the Clerget-Herzfeldprocess. Whereas the error of the ClergetrHerzfeld method, whenapplied to beet products, is due to the presence of amino-acids thathave a lower rotation in alkaline than in acid solution, the error-opposite in sense-with cane molasses is due to the fact that inpresence of basic lead acetate the dextro-rotation of a cane molassessolution is increased, owing to the effect of the reagent on thelaevulose always prcsent.90 Further notes on Pellet’s sulphurousacid method, which, as originally deszribed, did not give correctresults, have been published, and its advantages, as compared withAndrlik’s process, emphasised.91 A new test for the detection ofartificial invert sugar in honey has been described.Like Fiehe’stest,92 it depends on the presence of derivatives of furfuraldehyde inall artificial invert sugar, but i t is claimed that it is somewhatmore sensitive than Fiehe’s test.9387 J.Hetper, Bull. Aead. Sci. Crncozu, 1910, A., 601 ; A., 1911, ii, 331 ; Zeitsch8s Ann. Beport, 1910, 174.R9 J. P. Ogilvic, J. Soc. Chenz. IncZ., 1911, 30, 62 ; A., 1911, ii, 232..T. 1’. Ogilvie, Intern. S7cpr J., 2912, 14, 89; A . , 1912, ii, 393.y1 %d., 624.Ann. Beport, 1910, 174 ; 1911, 174 ; 1912, 215.93 F. M. Litterscheid, C J M ~ . Zeit., 1913, 37, 321 ; A., ii, 351.anal. Chem., 1911, 50, 343 ; ibid., 1912, 51, 409 ; A., 1912, ii, 811ANALYTICAL CHEMISTRY. 183As was the case last year,94 the only paper t o be recorded, inconnexion with the cryoscopic method for the detection andapproximate estimation of added water in milk, is dated fromAustralia,gs but, although nothing has yet been published here, itis satisfactory to be able to record that the possibilities of themethod are now being investigated in this country.Polenske’s method of detecting beef .and mutton fat in lard bythe difference between the melting and solidifying points of thefatsg6 has been shown to depend mainly on the fact that thea-palmitodistearin of lard has a “difference” value of 18.4, whilstthe P-palmitodistearin of beef and mutton fat has a (‘ difference ”value of 11.8.Tristemin has a very high ‘(difference” value(19*7), but the amount of tristearin in beef fat is not sufficient t ooutweigh the greater proportion of a-palmitodistearin in lard.97The very difficult problem of determining the relative proportionsof cocoanut oil and palm keriiel oil in mixtures of these two oilswith a third (margarine mixtures) forms the subject of a recentpaper, which describes a new method, which is not claimed as anexact method of anzlysis, but which has the merit of being inde-pendent of any assumptions as to the nature of the third con-stituent.I n point of accuracy, it is probably not greatly, if a tall, inferior to methods of this class.98 The introduction of hardened(hydrogenised) fats has considerably limited the conclusions whichmay legitimately be drawn from the results of analysis of any fattymixture. When nickel is present, there is a strong presumptionthat the mixture includes a hardened fat, and methods for thedetection of minute amounts of nickel have been improved.Failureto detect a metallic catalyst, however, is by no means evidence thata hydrogenised fat is not present, and there is reason to believethat before long hardened fats, free from any trace of metalliccatalyst, will appear in commerce, if they have not already done so.I n the absence of any other good method for the detection andestimation of glyceryl acetate in essential oils, attention may bedirected to a method which depends on the separation of theglycerol and its estimation by the triacetin rnethod.99 The onlyother method available is one described in one of Schimmel’sreports, which is less convenient, probably less trustworthy, andseems to have escaped the attention of abstractors of that documentof 200 pages.Ann. IZeport, 1912, 214.s,5 J.B. Henderson and 1,. A. Meston, Proc. Roy. SOC. Queenslnnd, 1913, 24, 165.96 E. Polenske, Arbeit. Kaiserl. Gesundh.-Amt., 1907, 26, 444.yS A. Bcinier and R. Limprich, Zcitsch. Nahr. CTenussm., 1913, 25, 367 ; A., ii, 444.98 H. It. Burnett and C. Revis, Ancc7yst,*1913, 38, 255.yy S. G. Hall and A. J. Harvey, J. Soc. Chenz. Ind., 1913, 32, 61 ; A., ii, 253184 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n a report on the present state of rubber analysis, made to theSixth Congress of the International Association for TestingMaterials in 1912, Hinrichsen recommends that, in the present stateof our knowledge, caoutchouc should still be estimated by dif-ference,' but since that date he has himself done much to improvethe direct method, which depends on the formation of a tetra-bromide of caoutchouc.2 The improvement consists mainly incarrying out the reaction in chloroform solution, cooled by ice.Under these conditions, the proportion of bromine in the product isindependent of the time of exposure t o the action of bromine.3 Amodification of the nitrosite method has been described.Brie%y,it consists in determining the carbon content of the nitrosite bycombustion analysis, and is therefore independent of the exactcomposition of the nitrosite, provided this contains all the carbonof the caoutchouc and no carbon from any other source. Themethod has given excellent results, but its author issues a warningthat much further work is required before it can be generallyrecommended.5 A new method depends on the action of sulphuricacid on caoutchouc in chloroform solution.The solution is violentlyagitated with concentrated sulphuric acid, poured into alcohol, andthe precipitate, which is said to have the composition (C10H16)10,H20,is washed with alcohol, dried a t looo, and weighed.6A report on the testing of indigo-dyed or reputed indigo-dyedwoollen and union fabrics may interest comparatively few, but isof great importance to those few, for the methods of analysishitherto published afford no trustworthy means of estimating thequantity of indigo on a cloth in presence of other dyestuffs, and nomethod has yet been proposed for determining the quantity of theconcomitant dyestuff. A t the request of the Textile Institute theseproblems were made the subject of investigation at the Universityof Leeds and a t the Technical College, Bradford, and as one resulta new method of estimating indigo has been worked out, which israpid, convenient of application, and gives accurate results evenon heavy and dense cloths, whilst the results are unaffected by thepresence of other dyestuffs.It is obvious that the simple statementof the percentage of indigo on a cloth does not afford to anybodybut an expert an idea of the quality of the dye. What is requiredby manufacturers and merchants is a means of knowing whatproportion of the total depth of colour is due to the indigo present.The solution of this problem might be expected t o be difficult,F. W. Hinrichsen, Chem.Engineer, 1913, 18, 165. Ann. Report, 1911, 176.F. W. Hinrichsen and E. Kicdscher, Zeitsch. anorg. Chem., 1913, 81, 70 ; A., ii,L. G . W'esson, J. Ind. Eng. Chem., 1913, 5, 398 ; A., ii, 631.534. Ann. Report, 1911, 176.ti R. Marquis and F. Heim, BUZZ. SOC. chim., 1913, [iv], 13, 862; A., ii, 884ANALYTICAL CHEMISTRY. 185having regard to the Pact that the dyestuffs accompanying theindigo are not necessarily blue, but are frequently violet or red.The authors, than whom none could better assess in advance themagnitude of the task they had undertaken, state that i t provedfar more laborious than was anticipated. They have, however,worked out two methods, one of which is applicable even to theheaviest shades, and their results show that the maximum errorof this method, in practised hands, is 7 per cent., a satisfactorydegree of accuracy where no alternative method exists.’A gricul tural Artalpis.Reference was made last year8 to the difficulty of preparingneutral solutions of ammonium citrate. Three methods have beendescribed this year, each of which is said to be as exact as themethod based on conductivity measurements a t constant tem-perature. Of these three methods, that of Patten and Marti isincomparably the simplest.It depends on the estimation of thecitric acid in the approximately neutral solution by titration withalkali in the presence of formaldehyde, and estimation of theammonia by distillation with rnagnesia.9The writer of last year’s report on Agricultural Chemistry madeit plain that before any material advance could be made in plantchemistry a thorough revision of analytical methods was necessary.Since then the estimation of carbohydrates in plant extracts hasbeen the subject of special study at Rothamsted, and a paper hasbeen published which concludes with a scheme for the estimationof dextrose, lmulose, maltose, sucrose, and pentoses in suchextracts.Certain sources of error encountered in the estimationof sugars in plant extracts are dealt with, and prominence isgiven to the fact that asbestos, unless previously treated withsodium hydroxide, is liable to be attacked by Fehling’s solution.This fact. has been so long known to the writer that he supposedi t was a matter of general knowledge, but the authors state thatthey have been unable t o find any previous mention of it.Thisbeing so, they have undoubtedly performed a useful service incalling attention to the fact, snd no apology is needed for givingfurther publicity to it here. Of the volumetric methods for theestimation of reducing sugars, that of Ling is found to be themost accurate as well as the most convenient. I n dealing withplant extracts, owing to the accumulation of sodium acetate,7 A. G. Green and others, J. ,700~. Dyem, 1913, 29, 226, 227.I( Am. Report, 1912, 218.J. M. Bell and C. F. Cowell, J. Amer. Chern. h’oc., 1913, 35, 49; A . , i, 162;A. J. Patten and W. C. Marti, J. Ind. E??g. Chcm., 1913, 5, 567 ; A . , ii, 7PO186 ANNUAL REPORTS ON THE PROGRESS OF CHEMIS‘I’KY.inversion of sucrose by citric acid of lower concentration than10 per cent.is generally incomplete. Inversion by invertase is notinterfered with by this salt. The only available method for theaccurate estimation of maltose consists in the employment ofmaltassfree yeasts, such as S. marxianus, as suggested some yearsago by Baker and Dick, who, however, did not succeed in makingthe method quantitative.The application to plant analysis of the hydrolysis of levulosansby acids is complicated by the fact that, in the presence of sulphuricacid and oxalic acid, at least 10 per cent. of the reducing sugarsare destroyed before hydrolysis is complete, and, although in highconcentrations of acetic acid, theoretical results may be obtained,the hydrolysis of inulin requires twelve hours, and the use of 10 percent.of acetic acid introduces difficulties when the liquid isneutralised for the estimation of reducing sugars. The use ofsulphosalicylic acid in moderate concentration is free from theseob j e ctions.llA paper on the non-nitrogenous ‘( extractive ” matters in fodderand foodstuffs is more important than its title might suggest, forthe so-called non-nitrogenous extractive matters form a group ofsomewhat indefinite composition, and are estimated by difference.Moreover, the very term “extractive” matters is a misnomer,since many of these substances are not extracted directly, but arerendered soluble by hydrolysis more or less profound. I n parti-cular, the pentosans, hemicelluloaes, and a portion of the ligninoccur in various degrees of condensation, and may appear partlyin the ‘‘ extractives” and partly in the “crude fibre,” accordingto the methods employed.Hitherto the author has appeared to bemainly concerned t o show that his method for the determinationof crude fibre ought t o be preferred to other methods,12 but theimportance of this paper lies in the avoidance of controversialmatters other than nominal ones, the recognition that a sharpseparation of groups of various degrees of resistance is impossible,and the suggestion that, in these circumstances, the adoption of aninternational standard method is desirable, as making the resultsof different workers at least comparable. Not everyone will approvethe author’s terminology, but his facts are beyond dispute, and wellmarshalled to support his suggestion of an international method.l3This has now been done.1010 W.A. Davis and A. J. Dnish, J. Agric. Sci., 1913, 5, 437.11 P. L. de Vilmorin and F. Levallois, Bull. SOC. chim., 1913, [iv], 13, 684 ; A . , iiI2 Ann. aport, 1912, 211.I:$ J. Ktjnig, .%itsclt. ATahr. Genzcssm., 1913, 26, 273.736ANALYTICAL CHEMISTRY. 187Physiological.A method for the separate estimation of acetic, isobutyric,isovaleric, and a-methylbutyric acids in mixtures of all four acidsowes its importance to t'he fact that these acids correspond withthe most commonly occurring aminocacids which result fromprotein hydrolysis, and that the mixed amino-acids can be easilyconverted into the corresponding fatty acids.The method, tliere-fore, gives quantitative information concerning the products ofprotein hydrolysis not readily obtainable by older methods. Itdepends on fractional moist combustion of the fatty acids bychromic acid. A t 6 5 O oxidation of secondary chains is completed,a t looo that of ketones to acids, whilst at 170° complete oxidationto carbon dioxide is reached. The determination of the carbondioxide produced at each stage and the total acidity of the mixturegive four data from which the percentage of each of the four acidsin the mixture can be calculated.14 A recent method for the estima-tion of amino-acids, peptides, and peptones depends on the factthat these substances dissolve cupric hydroxide quantitatively inthe cold to form a metallic complex in a neutral or faintly alkalinesolution, and an extension of the method permits of the rapid andaccurate estimation of histidine in mixtures.This useful extensionof the method depends on the fact that the copper complexes ofamino-a-hexoic acid and of phenylglycine are so sparingly solublethat these acids will precipitate the copper from solution of all theother complexes examined (seventy in number), excepting that ofhistidine.15 It has been shown that cystine and tyrosine can becompletely separated by treatment with absolute alcohol saturatedwith hydrogen chloride. The tyrosine is converted into its ethylester, which dissolves, whereas the unaltered cystine remains undis-solved. The separation by means of phosphotungstic acid is nearlyas sharp, but in that case the cystine can never be recoveredquantitatively from the precipitate.le Pyrrolidonecarboxylic acidmay be separated from glutamic and other amino-acids by takingadvantage of the fact that i& silver salt is readily esterified byethyl iodide, whereas, under similar conditions, glutamic acid,aspartic acid, asparagine, and proline remain unaltered.17Ruhemann's triketohydrindene hydrate reaction 18 has been thel5 P.A. Kober and I<. Sugiura, J. Amer. Chem. Soc., 1913, 35, 1546; A . , ii16 R. H. A. Plinimer, Riockm. J., 1913, 7, 311 ; A., ii, 806.'7 E. Abderlialdeu and I<. I~auti.sch, Zeitsch. physiol. Cht?iz., 1912, 78, 115 ;l8 Ann. Report, 1911, 179.I(. Lalighe~d a i d A. Zeileis, Ber., 1913, 46, i171 ; A., ii, 443.990.A , , 1912, i, 492188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.subject of further studies. Its sensitiveness is even greater thanwas a t first supposed, 1 part of glycine in 65,000 giving a distinctblue c01oration.l~ A number of substances containing primaryalcoholic, aldehydic, and ketonic groups give colour reactions onboiling with triketohydrindene hydrate, the coloration in the caseof glycerol, dextrose, and amyl alcohol being blue, but thesereactions occur only in highly concentrated and neutral solutions,and do not take place in dilute solutions or in the cold. I n thisand in other respech they differ from the reaction with amino-acids, which occurs in the cold and even in a vacuum.20A method has been described by means of which oxycholesterolcan be estimated in the unsaponifiable products obtained fromtissues and other sources. This substance givss a colour reactionwith a mixture of acetic and sulphuric acids, which is readilyconverted to a pure green colour by addition of a trace of ferricchloride. Solutions obtained in this way give a spectrum with awell-defined band in the red, the breadth of which is proportionalto the amount of oxycholesterol in the solution. As the esters ofoxycholesterol do not give the colour reaction, i t is possible toestimate these by determining the amount of oxycholesterol presentbefore and after hydrolysis.21A novel suggestion for the estimation of urea in urine or bloodis t o convert it into ammonium carbonate by means of the uremeof soy beans, and then t o remove the ammonia in a current of air(Folin’s method).22 The ordinary hypobromite method has beensubjected to renewed criticism, the authors of one paper contentingthemselves with the observation that the results tend to be high,and recommending a blank test,23 whilst another author has shownthat the reaction does not proceed completely according to thegenerally accepted equation, but that part of the nitrogen isconverted into oxygen compounds and part of the carbon is onlyoxidised to carbon monoxide. Of the conditions which influencethe course of the reaction, the most important is the ratio ofbromine t o sodium hydroxide. Under certain conditions, statedin the paper, pure urea yields the theoretical volume of gas,although this gas is not pure nitrogen, but certain other constitu-ents of normal urine evolve nitrogen on treatment with hypo-19 E. Abderhalden and H. Schmidt, Zeitsch. physiol. Chcm,, 1913, 85, 143 ;20 W. Halle, E. Loewenstein, and E. PPibram, Biochem. Zcitsch., 1913, 55, 357 ;21 I. LiBchutz, ibid., 48, 373 ; A., ii, 350.A., ii, 643.A., ii, 992.E. K. Marshall, juii., J. Bio2. Chem., 1913, 15, 487, 495 ; A . , ii, 991.L, Grimltert and M. Landat, J. Pharnt. Chim., 1913, [vii], 7, 569 ; A., ii, 739ANALYTICAL CHEMISTRY. 189bromit'e. This source of error can be reduced, but not entirelyeliminated, by previous treatment with phosphotungstic acid, sothat the results of the most careful work tend to be high. In thepresence of dextrose the error is large, much carbon monoxidebeing formed and all the nitrogen appearing as S U C ~ . ~ ~G. CECIL JONES.24 M. Krogli, Zeitsch. physiol. Cheirz., 1913, 84, 379 ; A . , ii, 641

ISSN:0365-6217    

DOI:10.1039/AR9131000162

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.AMONG the textbooks of the year, the first volume of the thirdedition of Abderhalden’s “ Lehrbuch,” dealing with the chemistryand metabolism of proteins, fats, and carbohydrates, must bespecially mentioned. The work has been re-written, and is indeedan entirely new book. It contains references to quite the mostrecent literature. The author claims to have consulted twentythousand original papers in its preparation! It can only be saidthat the task of selection has been carried out with judgment, andthe book is another instance of its author’s almost miraculouscapzcity f o r labour. It gives a singularly suggestive presentationof the more important facts of a rapidly growing science.The second volume of v. Fiirth’s new book2 has appeared; i tsupplies an interesting account of digestion and metabolism. Neweditions of Biedl’s “ Innere Sekretion ” 3 and of Czapek’s “ Bio-chemie der Pflanzen ” 4 should be mentioned.Each successive year brings proof that biochemistry is nowattracting workers in rapidly increasing numbers.The output ofpapers in 1913 was very large, over five hundred researches beingdescribed in the Biochemische Zeitschrift alone. It is doubtful ifreally new ground has been broken. A retrospect of the yearmust for the most part deal with the development of enterprisesbegun before it opened. No paper, I think, has appeared which toa reviewer gifted with no more than ordinary insight suggests theopening of a new chapter in the science. Progress, nevertheless,has been very real.I f one were to endeavour to decide upon what is the most hopefulfeature in the progress of the moment, I think i t would be foundin the increasing provision of accurate quantitative methods applic-able t o the determination of metabolites when present in minuteamounts.For such methods physiological chemistry has long“ Lehrbuch der physiologischen Chcmie,” Abderhalden, Urban und Schmarzen-berg, Berlin and Vienna.“ Problenie der physiologischen nnd pathologiwhen Chcmie,” Von Furth, Vogel,Leipzig.Urhan nnd Schwarzenberg. Gustav Fischer, Jena.113PHYSIOLOGICAL CHEMISTRY. 191waited. When we want to study tlie eciuilibriuin between theblood and tissues we have often, from the nature of the case, todeal with substances in trivial quantities, and determine variationswhich, although profoundly significant, may be very small.I n thecase of the blood we need, tou, to be able to work upon a smallamount of total material, because it so often is necessary to with-draw i t from the living animal or from human individuals. Theservice rendered by Barcroft, Folin, Van Slyke,5 Ivar Bang,s andothers in providing trustworthy methods applicable under themconditions is extraordinarily great, as the haste on the part ofothers to use them has proved. Any lingering disbelief in thequantitative possibilities of microchemical methods must give wayin face of accomplished facts.Another very hopeful feature in current work is the proof it isbringing that the new physical chemistry, especially that chapterof it which relates to the mutual influence of colloids and electro-lytes, is directly applicable to the study of the tissues whilst stillliving, and most fertile in explaining certain aspects of theirbehaviour. No one who reads, for instance, the papers of G.R.Mines, which deal with the physico-chemical properties of circu-lating media as they affect the beating heart, can fail to rsalisethis. \%'e recognise, too, that owing to the progress of physicalchemistry, infinitely greater precision is being given to work doneupon the blood and the other colloidal fluids from the body. I f Imay again quote in illustration of this English work alone, I wouldrefer to recent papers by C. J. Martin and Harriette Chick.7I have found it impossible to devote a special section of thisreport to progress made on these lines, although it has been great.The Chemistry of Protein and Protein Metabolism.Some not unimportant advances have been made towards thebetter definition of the properties of individual proteins, and somevaluable evidence has accumulated bearing on the structure andconfiguration of the protein molecule, whilst our knowledge of theintermediary metabolism of proteins progresses in a satisfactorymanner.To illustrate the advances being made on the lines first men-tioned, I may quote the work of L.L. Van Slyke and Bosworthson caseinogen and casein. Having obtained these two proteinsJ. Biol. Chem., 1913, 16, 121 ; A . , ii, 1084.Biochern. Zeitsclz., 1913, 49, 19 ; A ., ii, 446 ; ibid., 51, 193 ; A . ii, 740; ibitl.,For example, Biochem. J., 1913, 7, 318 ; A , , i, 915.57, 300 ; A . , 1914, ii, 75.' J. EioL CIuwt., 1913, 14, 231 ; il., i, 660192 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in a form especially pure (their preparations, unlike most samplesof ‘‘ pure ” casein, were practically ash-free), they prepared firstof dl, by two distinct methods, a basic calcimn salt of each. Thesecompounds were neutral to phenolphthalein. However prepared,they showed a satisfactory constancy in their composition, whichwas such as to indicate that 1 gram of protein was in each casecombined with 9 x 10-4 gram-equivalent of calcium.It was next shown that, in the case of caseinogen, solublecompounds are formed with ammonium, sodium, and potassium,in which 1 grain of protein is combined with only 1-25 gram-equiva-lenh of the base.With calcium, strontium, and barium, on theother hand, two sets of compounds are formed. Members of thefirst set are insoluble, and correspond in composition with thealkali compounds just mentioned, whilst in members of the secondset, which are soluble, 1 gram of protein is combined with2-25 x 10-4 gram-equivalent of calcium, etc. I n the case of caseinthe interesting fact was demonstrated that although it yieldscompounds which in other respects correspond precisely with thoseof caseinogen, its molecule is in each case, except that of the basiccompound first mentioned, combined with exactly twice the quantityof base.When, therefore, caseinogen is converted into casein underthe influence of rennin its molecule would appear to be exactlyhalved. Judging from the percentages of base present in thevarious compounds described, and making certain assumptions asto the valencies of the proteins, the authors conclude that theequivalent weight of caseinogen is 8888, which agrees well withthe figures obtained by calculation from its sulphur and phosphoruscontent. The equivalent weight of casein then becomes 4444. Thequantitative work in this paper seems to be exceedingly satisfac-tory, and I quote it as an instance of the increasing precisionwith which such studies are being made.I n illustration of recent productive investigations into the consti-tution of protein, I will quote first the work of Dakin andDudley 9 on racemised casein.This work, which followed similarstudies made by Dakin on gelatin last year,1° is essentially anextension of the yet earlier researches of Kossel and Weiss,ll whoshowed that proteins, when digested at low temperatures withdilute alkali, undergo a rapid diminution of optical activity, which,however, is never completely abolished. Kossel and Weiss regardedthe phenomenon as one of protein racemisation, and since on acidhydrolysis of the racemised material they obtained optically9 J. Biol. Chem., 1913, 15, 263, 271 ; A . , i, 1249.lo Ibid., 1912, 13, 357 ; A . , i, 208.11 Zeitsch. physiot. Chem., 1909, 59, 492 ; 1910, 68, 165 ; A., 1909, i, 542 ; 1910,i, 791PHYSIOLOGICAL CHEMISTRY.193inactive arginine, etc., they came to the interesting conclusionthat certain of the protein Bausteine undergo racemisation muchmore readily when bound " intraprotein " than when free. Activearginine, for instance, is not affected in this sense by dilute alkali.Dakin advances a hypothesis t o account for the facts, which seemsentirely satisfactory. Supported by his own earlier observationson the contrasted behaviour of hydantoins and uramido-acids, hecomes to the conclusion that racemisation occurs when the peptidelinking exists, because there is then the possibility of keto-enolisomerism, of which the free amino-acids are incapable. The follow-ing formulae, representing the equilibrium between the two formsof a peptide grouping, make this point clear :r;JH*CO* -+ TH*CO*R*C H*CO*NH*CHR*CO,H f- R*C:C(OH)*NH*CHR*CO,HWhen, under the influence of the alkali, the enol form is producedeven to a small extent, racemisation must necessarily follow, sincethe asymmetry of the a-carbon atom is abolished. I n these con-siderations another important point is involved.Of the twoamino-acids concerned in the above peptide association, only thatcontaining the -CH*COm group could exhibit keto-enol isomerism,and so undergo racemisation ; that containing the free carboxylgroup would remain unchanged under the influence of the dilutealkali. The condition of the latter represents that of the terminalmembers of any complex chain of linked amino-acids such as mayexist in the protein molecule.Hydrolysis of a racemised proteinshould therefore lead to the appearance of both active and inactiveamino-acids, the former being those of which the carboxyl groupsoriginally shared in a peptide linking, the latter those of whichthe position was terminal in the peptide chains. When caseinwas racemised and afterwards submitted to acid hydrolysis, all theamino-acids obtained by Dakin and Dudley were inactive, with theexception of valine, leucine, and proline, and with the possibleexception of alanine. The valine and leucine were partly in anactive form, and the proline wholly so. I n the case of racemisedgelatin, Dakin had previously shown that glutamic acid and lysineare obtained active, although they are racemised by alkali when inthe molecula of casein.There is a strong suggestion, therefore,that their relations are not the same throughout the molecules ofgelatin and casein respectively.I n a further paper Dakin and Dudleyl2 show that racemisedcasein is unattacked when submitted to the action of pepsin,trypsin, and erepsin. So completely resistant is it that no peptidelinkings seem to remain in their original condition, otherwisela J. Bid. Chc?n., 1913, 15, 271 : A . , i, 1278.REP.-VOL. X. 194 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.splitting at such lirtkiiigs should occur. When given t o an animalthe racemised protein is excreted unchanged in the faeces.Similar to the above in its bearings ie the work of F. Obermayerand R. \Villheim,l3 who have applied Soyensen’s formaldehydetitration method, which has proved so extraordinarily useful inall work concerned with amino-acids, to a determination of therelative number of free amino-groups in diffe’rent proteins.The quotient obtained by dividing the total nitrogen by thenitrogen of the terminal amino-groups they term the amino-index, and its value differs markedly in different proteins.It is,fo,r instance, of the order of 21.5 in euglobulin and about 12 inalbumin. I n studying the bloods of widely different species theyfind marked differences in the amino-index of correspondingfractions, although results from the blood of the goose agree withthose from ~ O W W blood, and horses’ blood agrees with ox blood.The amino-index thus simply obtained will probably prove to bea characteristic stamp of an individual protein, and may assistas a criterion of purity when we are endeavouring to isolateindividuals from protein mixtures.Evidence concerning the constitution of proteins such as thatoffered by the two researches last quoted, although it may not yetcarry us very far, comes, nevertheless, to the aid of the syntheticstudies, which since Emil Fischer initiated them have gone onapace.One hm but to glance a t the recently published subjectiindex of the Journal of the Society to realise how actively thestudy of synthetic polypeptides is progressing, especially, but by nomeans exclusively, in the hands of Abderhalden and his co-workers.So much industry indeed and eo much ingenuity are being broughtto bear upon the problem that one may feel sometimes tempted tohope that the actual synthesis of a natural protein may be seenby the present generation.It is probably a far cry t o thataccomplishment, however, and it may be noted that Dakin andDudley in the paper first quoted remark that their results raise adoubt as t o whether it will ever be possible by existing methodsto synthesise a naturally occurring protein. For treatment ofcompounds containing peptide linkings with alkali occurs in allthese processes, and with large molecules of this character racemisa-tion of t’he type dealt with would most probably occur. From thebiological point of view, too, we must remember that the proteinsof the tissues are very many and very diverse; colossal labours willhave t o precede the arrival of exact knowledge concerning theconstitution and configuration of them all.Although even thisknowledge must be available before descriptive biochemistry canlY Biochem. Zeitsch., 1913, 50, 369 ; A , , i, 668PHYSIOLOGICAL CHEMISTRY. 195say its filial word on protein equilibrium iu the animal body, i t isbecoming increasingly sure that we shall not have to wait for suchfar-off knowledge before some of the most significant aspects ofintermediary metabolism become clear t o us. From some points ofview, and those wide-embracing ones, we are entitled, it seemsto me, to look upon the food proteins, and, no less, the proteinsof the living tissues, as mere stores of amino-acids.The actualchemical dynamies of the body are concerned in the main with thelatter as individuals. It is the physico-chemical properties of theintact tissue proteins rather than their exact constitution thatconcerns us at present. A preliminary hydrolysis, and that perhapsof the most complete kind, would appear to be the fate of allprotein which is to undergo metabolism, whether the processesstart in the gut or in the tissues, It is free amino-acids that enterthe paths of significant change, and studies that have alreadyproved highly profitable, and are likely to prove so for a long timeto come, deal with the special fate of individual amino-acids inthe body.One may suggest here, in parenthesis, that it is perhaps becauseneither the intact molecule of protein nor complex polypeptidessuffer oxidation, as such, in the body, that studies of proteinoxidation in vitro have led to so little of physiological interest.Nevertheless, such studies continue, and doubtless deserve atten-tion.0. Eisler,l4 continuing the work of v. Furth, has describedthe r e d t s of oxidising casein and fibroin with potassium perman-ganate. One rather remarkable result was noted in t h s case of thelatter substance. The chief oxidation product separated was acomplex containing no less than 50 per cent. of its nitrogen in thebasic form. The author compares this concentration of bases towhat happens in the formation of protamines during the ripeningof the testicle. The physiological application of the results seems,however, to be as remote as the chemistry of the process is obscure.I n previous reportcr Professor Halliburton has very fullyreviewed the gradually accumulating evidence which shows thelarge part played in metabolism by liberated amino-acids, Thematter must be further dealt with here because important workdealing with it has been carried out during the past year.Abder-halden,lb for instance, has added yet another paper to a long seriesin proof of the ability of the animal to maintain itself when fedwith a polypeptide-free mixture of amino-acids. This paper carriesthe air of finality, and would certainly seem to make any furtherevidence on the point quite unnecessary. The material fed was s9l4 Biochem. Zt,itsch., 1913, 51, 26 ; A ., i, 777.Zeitsch.physioZ. Chem., 1913, 83, 444; A., i, 419.0 196 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.thoroughly predigested as to contain no intact polypeptide materialwhatever. On this as its sole nitrogenous supply a dog lived inperfect health for one hundred days. During this period theanimal gained 10 kilos. in body-weight, and, when the experimentclosed there was nothing to suggest that it might not have beencontinued indefinitely. The dog was shaved before the specialdiet was given, and 76 grams of hair containing about 10 gramsof nitrogen were removed. This had completely re-grown by thetime the experiment was finished, and Abderhalden adducm thefact as an objective demonstration of protein synthesis! I n thisresearch, which was so conducted in all its details as to leave noloophole for criticism (the author fed and controlled the animalpersonally throughout), further proof was obtained of the factthat when tryptophan is removed the amino-acid mixture is nolonger capable of maintaining the animal, and tyrosine was alsoshown to be necessary.Such observations as these will ultimatelyhelp us to decide exactly what amino-acids the body can, or cannot,synthesise for itself.The work of 0. Folin and W. Denis and that of D. D. van Slykeand G. M. Meyer, referred to in last year’s report as giving suchcogent proof of the fa& that liberated amino-acids are absorbed assuch from the intestine and reach the blood and tissues whilst stillfree and uncombined, has in each cwe been extended.Abder-halden,l6 who has long maintained a sceptical attitude in thismatter, has now himself actually separated. from the blood a numberof individual amino-acids, and fully identified them. Needless tosay, this accomplishment involved working on an enormous quantityof material. Folin and Denis17 give us careful determinations ofvarious forms of non-protein nitrogen in the blood of a greatnumber of individuals, healthy and otherwise. Van Slyke andMeyer 18 have set themselves to trace the amino-acids as they leaveth0 blood for the tissues, and, finally, to get information as to thelocus of their transformation. It is already made clear that, in thecase of such tissues a~ the muscles, the acids are merely absorbedfrom the blood without undergoing any immediate chemicalchange.When an increase occurs in the circulation the musclecan take up amino-acids until some 75 to 80 milligrams per100 grams of their substance are present. A t this point theybecome saturahd, and remain for considerable periods in equili-brium with the blood. On the other hand, in the case of the liverthere is a much larger initial increase (up to 150 milligrams per100 grams), but the rise in the organ is followed by a period of16 Zeitsch. physiol. Chem., 1913, 88, 478.I7 J. Bwl. Chmn., 1913. 14, 29 ; A . , i, 310.-I8 did., 1913, 16, $97, 213, 231; A., 1914, i, 104, 105PHYSIOLOGICAL CHEMISTRY. 197rapid fall, during which urea increases in the blood. There can belittle doubt, therefore, that the liver plays ilr prominent part inthe more general course of amino-acid katabolism.The free amino-acids present in the tissues do not disappear during prolongedstarvation, but tend rather t o increase above the normal mean.The supply must therefore be kept up from the tissues themselves.Autolysis must occur in vivo, and, even in the case of tissueproteins, metabolism begins with the liberation of their Bwsteime.As regards the katabolic breakdown of amino-acids the year hascontributed something to the interesting collection of facts in ourpossession. H. D. Dakin and H. W. Dudley19 state that all amino-acids undergo dissociation in solution into a-ketonic aldehydes andammonia :R*CE*NH,=CO,H 2 R*CO*CHO + NH,.I f this be so, the production of the corresponding keto-acid, whichis now so universally recognised as the first stage in the break-down of an amino-acid in the body, is merely the direct oxidationof an aldehyde.I n connexion with the further stages of change,Dakin 20 has examined several previously untried amino-acids withrespect to their capacity, on the one hand, of yielding dextrosewhen givea to a diabetic animal, and, on the other, of acting asprecursors of acetoacetic acid when perfused through the liver.Seventeen have now been tested in this way, and the interestingfact has come to light that those which yield sugar do not yieldacetoacetic acid, and those which give the latter are incapable ofbeing converted into dextrose. Some of the protein Bausteinefollow, therefore, the path of carbohydrate metabolism, whilstothers ultimately join the path taken by fatty acids.Anothervery small group seems to enter on neither of these paths. I nconnexion with the special fate of phenylalanine, the work ofEmbden and Baldes 21 has given unexpected results. Phenyl-pyruvic acid does not yield acetoacetic acid in the liver, and so isprobably not, as analogy would suggest it should be, the normalprimary oxidation product of phenylalanine. Oxidation wouldseem first to occur in the ring, for I-a-phenylalanine, when perfusedthrough the liver, gives rise to normal I-tyrosine, so that furtherbreakdown would be on lines pertaining to the latter, a mostinteresting fact. The metabolic significance of the phenylalaninecontained in any protein would seem to be identical with thatof its tyrosine, if the former is in this way first converted into thelatter.l9 J.&'oL Che?n., 1913, 14, 558 ; A . , i, 925.2o Ibici., 321 ; A., i, 671.'31 Biochcm. Zeitsch., 1913, 55, 301 ; A . , i, 1279198 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The realisation of the fact that each constituent of protein hasspecial relations in metabolism and may subserve a special purposein the body, adds more than a purely chemical interest to thediscovery of new amino-acids in the protein molecule. We havefully realised that the tale of these was probably not complete,but it is rather startling to' find that the year has offered someevidence for the existence of no less than three additional ones.Abderhalden and Wei122 have obtained from the proteins ofnervous tissues the straight-chain isomeride of leucine (a-amino-llchexoic acid), which they propose to call norleucine.Foreman 23has given evidence for the existence of an a-aminobutyric acid incasein, and M. Guggenheim24 has separated from the tissues ofT i c i a faba an acid which is almost certainly 3 : 4-dihydroxyphenyl-a-aminopropionic acid. Although the latter waa not obtained byhydrolysis of protein, there can hardly be a doubt that it arisesfrom autolysis of the proteins of the plant.A few words may now be given to a quite different aspect of theproteir; question. A desire to discover what is the minimumamount of protein on which thO human body can maintain itselfis still in the minds of many.I n a research carried out byHindhede 25 a t Copenhagen, nitrogenous equilibrium, and,apparently, good health, were maintained in certain individuals onan extraordinarily low intake. I n the case of one person, Madsen,a diet consisting almost wholly of potatoes and margarine was wellborne. On this diet and under average conditions of activity theprotein consumption necessary for equilibrium was only 19 gramsdaily. 111 the presentation of such facts there is usually anunnecessary assumption that the low intake is physiologicallyvirtuous. We may set against. Hindhede's research, however, anextraordinarily interesting study of the dietetic habits of Esqui-maux by A. and M. Krogh.26 Here in actual quantitative experi-ments we find individuals consuming over 500 grams of proteindaily, with results entirely satisfactory ta themselves, and yet thisexperimental consumption fell far below that of individuals freeto follow their instincts! We find in these two researches note-worthy evidence of the wide ranges t o which the body can adjustitself. It is quite sure that the physiological optimum of proteincan only be defined in relation to personal and racial peculiarities,as well as habih and environment.22 Zeilsch.physiol. Chem., 1913, 88, 272 ; A . , 1914, i, 20.28 Biochcm. Zeitsch., 1913, 56, 1 ; A., i, 1249.24 Zeitsch. physiol. Chem., 1913, 88, 276 ; A., 1914, i, 49.25 Skmd. Archio. Physiol., 191 3, 30, 97.'L6 Ilfctldelelscr om C1'rooldand, 1913, 51 ; A ., 1914, i, 106PHYSIOLOGICAL CHEMISTRY. 199Pzcrine Metabolism.The extraordinary activity which has been displayed in quiterecent years in connexion with the constitution of the nucleic acidsand the related subject of purine metabolism has for the momentdiminished. H. Steudel27 hasbegun a study of the nucleohistone of Lilienfeld, which is likelyto add accuracy to our knowledge of that substance. He confirmsexactly the original account of its composition, although withoutclaiming that this confirmation proves it to be a chemical indi-vidual; he shows that it contains no other phosphorus than thatpresent in true nucleic acid. 11, Dohrn 28 has described a somewhatslight research on the effect of feeding thymus-nucleic acid to ayoung man.The only point of significance in the results was thatthe urea nitrogen was unaffected. The increase in the uric acidnitrogen represented under 10 per cent. of the basic nitrogen given,and the rest wm not recovered. Nevertheless, the excess phosphorusexcretion was proportionate to that present in the nucleic acidgiven. As emphaaising the exceptional position of man in excret-ing unoxidised uric acid rather than allantoin, we have the workof A. Hunter and M. H. Givens.29 They show that even themonkey (Cercopithicus) departs from the human type of purinemetabolism and excretes allantoin. The same observers 30 havegreatly added to the list of species studied in this connexion, andfind that the power to oxidise uric acid is possessed by thefollowing groups in decreasing degree : Carnivora, rodents, ungu-lates, marsupials, man.E. R. Long31 finds that the fermentadenase is absent from the human liver, and could discover nonein individual foetal tissues. I n some cases it is certainly presentin the fetus, as experiments with an emulsion of the whole bodyshowed, but it could not be localised. Certainly the most impor-tant paper of the year bearing in any way on purine metabolismis that by Folin and Denis already quoted. It is full of suggestivepoints. Among them we may note the most interesting fact thathuman blood contains several times as much uric acid as does theblood of any other animal examined, This corresponds with thehigher excretion in the case of man.I n the case of gout, however,we may have much larger quantities circulating than normalwithout increased excretion, showing, in Folin’s opinion, a failureon the part of the kidneys. This failure must be related specificallyI need quote only a few papers.Zeitsch. physiol. Chem., 1913, 87, 207 ; A., i, 1216.28 Ibid., 1913,:86, 130 ; A., i, 1016.XI J. Riol. Chem., 1913, 13, 371 ; A., i, 126.3o Proc. Amer. SOC. Eiol. Chem., 1912-13, xsiv-xxv ; J. Bid. Chew., 14 ; A. , i,558. a J. Bio,?. Che?n., 1913, 15, 449 ; A , , i, 1272200 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to uric acid, for other non-protein nitrogenous substances may benormal in the blood of gouty individuals.The Metabolism of Carbohydrates amd Fata.I n the endeavour t o establish the successive steps involved inthe breakdown of the dextrose molecule in the body, most workershave regarded cleavage into a molecule containing three carbonatoms as being the first step involved.As there is now no reason-able doubt that one line at least of carbohydrate katabolism passesthrough the stage of lactic acid, recent work on the question hasbeen largely concentrated on a search for the precursors of thatacid. Many facts already acquired point to glyceraldehyde asbeing in all probability the first-formed product from sugar; forthe moment the evidence in favour of this, although cogentenough, remains in the main of an indirect character. Meanwhile,during the past year, certain very striking researches haveawakened interest in those substances which represent intermediarystages between glyceraldehyde and lactic acid ; in particular, atten-tion is being drawn to pyruvaldehyde (methylglyoxal) and pyruvicacid, both of which can, of course, be obtained from dextrose bychemical means.Early in the year Dakin and Dudley32 publishedthe noteworthy observation that tissue extracts acting at bodytemperatura rapidly convert methylglyoxal into lactic acid :CH,*CO*COH+ H,O -+ CH,*CH(OH)*CO,H.Almost immediately after Dakin’s publication C. Neuberg 33 con-firmed the observation on independent lines, whilst P. A. Leveneand G. M. Meyer34 showed that intact leucocytw brought aboutthe same change. Later Dakin showed that the keto-aldehydeyields lactic acid when perfused through the isolated liver.To complete the account of the relationships which exist, itmust be first stated that Dakin obtained the dinitrophenylhydr-azone of methylglyoxal from lactic acid by simply mixing solutionsof the latter with nitrophenylhydrazine, whilst he proved thatmet.hylglyoxa1 yields dextrose when. administered to a glycosuricanimal, just as does lactic acid itself.Alanine also, as we haveseen, yields methylglyoxal with readinem The biological signi-ficance of this keto-aldehyde can therefore scarcely be in question,and the following equilibrium relations probably obtain in meta-bolism, the reactions involved being reversible :C6H1206 i t CH,*CH(OH)*C02H ZZ CH,*CO*CO,H Z CH,*CH( NH,)*CO,H.Biockem. Zeitsch., 1913, 51, 484; A ., i, 927.32 J, Bid. Chem., 1913, 14, 155 ; A . , i, 565.34 J. Bio2. Chcm., 1913, 14, 651 ; A., i, 932PHYSIOLOGICAL CHEMISTRY. 201The direct derivation of lactic acid from methylglyoxal involvesthe addition of a molecule of water, a process which in this casewe ought perhaps to regard (as Neuberg suggests) as a kind of“ internal Gannizzaro’s reaction.” If, on the other hand, pyruvicacid should prove to emerge as an intermediate metabolite betweenmethylglyoxal and lactic acid, there would clearly be a significantdifference in the chemical mechanisms involved. Biological interesti n pyruvic acid has been awakened by Neuberg’s observation thati t is easily fermentable by yeast, and by the fact that being theketo-acid corresponding with alanine it might well be expected toappear in metabolism.G. Embden and M. Oppenheimer35 findthat it yields lactic acid when perfused through a glycogen-freeliver. P. Mayer36 was unable t o obtain any increase of sugar asa result of aldministering i t to phloridzinised dogs. A. I. Ringer,E. 35. Frankel, and L. Jonas3’ obtained some increase, but as itwas small compared to the sugar produced from either alanine orlactic acid in similar circumstancw they concluded that pyruvicacid is unlikely to be an obligatory stage in the conversion ofalanine into lactic acid. Dakin and JanneyS8 agree with thisconclusion, and hold that in so far as pyruvic acid is a precursorof sugar in the body, i t is because i t may be directly reduced tolactic acid, which then passes by way of methylglyoxal to dextrose.Many points of interest in the papers just referred to cannot bedealt with here.It is clear that more experimental work isnecessary to render the metabolic relations between dextrose andlactic acid certain; but the very fact that the current work here,as elsewhere in studies of intermediary metabolism, is now able todeal with details shows how much progress has been made.The importance of the influence of the pancreas in carbohydratemetabolism has been before us for so many years that it is disap-pointing to feel that w0 are still in the dark as t o how it isexerted. Experiments dealing with the sugar consumption ofthe heart from normal and de-pancreatised animals respectivelyseemed to show quite definitely that the pancreatic factor wasactive at the locus of utilisation, but Starling and his co-workersnow find that these experiments give inconclusive results.Firstof all, E. W. H. Cruickshank39 finds that the heart of the de-pan-creatised animal is apt t o contain more than a normal amount ofglycogen, and S. W. Patterson and E. H. Starling4O find that the:ij Biochcm. Zeitsch., 1913, 55, 334; A., i, 1275.DG Ibid., 1913, 49, 4 8 6 ; A., i, 564.37 J. Biol. ClLem., 1913, 15, 145 ; A , , i, 937.89 J. Physiol., 1913, 47, 1 ; A., i, 1268.Ibid., 177 ; A . , i, 937.Ibid., 137 ; A , , i, 1263202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.energy necessary for its work may be obtained from this internalstore. This explains why in earlier experiments there was noconsumption of sugar from the circulating medium.Althoughthe further experiments of Cruickshank and Patterson 41 on theheart of the cat seem to point to a certain degree of diminutionin the carbohydrate metabolism of the diabetic heart, the totalevidence remains inconclusive ; Starling, indeed, is inclined toabandon the view that the essential or, at any rate, the primaryfactor i n diabetes is the absence of power on the part of the tissuesto consume sugar.The above evidence concerning the pancreas is supported by theobservations of J. R. Murlin and B. Kramer,42 who were unableto obtain as the result of injecting pancreatic extracts intode-pancreatised dogs any specific effect on the dextrose-nitrogenratio, or on the respiratory quotient which could be interpretedas an index of increased combustion of carbohydrate.This was alsothe experience of F. Verz6r and A. von FejBr.43 A. Gigon andM. Massini,44 using the alder technique of Cohnheim, were alsounable to discover that the addition of pancreas preparations hadany effect in increasing the power of crushed muscles t o destroy( 1 polymerise) sugar. The work of the year seems to suggest onthe whole that the pancreas is concerned in stabilising the carbo-hydrate sources of the body rather than in promoting the actualutilisation of sugar. VerzBr and Fej6r45 state that the intravenousinjection of sugar a t the height of the diabetes due to the removalof the pancreas has no effect whatever on the respiratory quotient,and they advance this as sufficient proof of the fact that no traceof sugar oxidation occurs.It is extraordinary if, in the absenceof its pancreas, the otherwise intact animal is really wholly unableto use sugar, that isolated organs from the same animal can appa-rently use it. An explanation of this paradox would, it seems to me,carry much of importance in its train.In connexion with the influence of other glands on carbohydrateequilibrium, I have space only to mention one very interestingresearch. L. H. Weed, H. Cushing, and C. Jacobsou46 have shownthat stimulation of the cervical sympathetic nerve, or of thO" sugar centre " in the bulb, liberates a hormone from the posteriorlobe of the pituitary body, which causes glycogenolysis and glycos-uria.They excluded any possibility of the effect being due to adirect nervous stimulation of the muscles or viscera.41 J. Ph,ysioZ., 1913, 47, 381.42 J. Biol. Chem., 1913, 15, 365 ; A . , i, 1268..u Biochem. Zeitsch., 1913, 53, 140 ; A., i, 1022.44 W d . , 1913, 55, 189 ; A . , i, 1270. q5 LOC. c i f .Airier. J. P l t y ~ i d . , 1913, 31, xiii-xiv ; A . , i, 309PHYSIOLOGICAL CHEMISTRY. 203No point in the history of carbohydrate metabolism is moreinteresting than that at which in a somewhat mysterious mannerit trenches upon the metabolism of fat. The standing questionas to why the oxidation of fatty acids fails to go to completionwhen carbohydrates or derivatives from carbohydrates are, forthis or that reason, not available, was never more to the forefrontthan now.A solution of this puzzle is, indeed, much called for,and would be a gain to practical medicine as well as to physiology.We cannot be content any more t o rest upon such phrases as“fats only burn in a fire lit by carbohydrates,” and the like; wewant an explanation in terms of understandable chemical reactions,and it may be said that most of the attempts to get a t the detailsof carbohydrate and fat metabolism are converging upon thisparticular problem. Many papers of the year have been concernedwith it directly or indirectly, but I have only space to mention afew. Those I have chosen are not necessarily the most interesting,but they contain points which are more or less new.The aceto-acetic acid which arises from successive &oxidations of the physio-logical fatty acids, and from certain amino-acids (see above), isnormally, of course, further changed in the body, but not ifcarbohydrates are absent, and not if the tissues are unable to usecarbohydrates efficiently, as in diabetes. Then we have thO condi-tion of acidosis, in which unaltered acetoacetic acid circulates inthe blood. I n explanation, some have thought of the possibilityof a condensation occurring between the keto-acid and aldehydesderived from carbohydrates, a combination yielding possibly a morereadily oxidised substance. This year one worker a t least haspostulated a combination before breakdown, and having preparedfatty acid esters of dextrose, has decided their physiological proper-ties.But the results of the research do not allow of any verydefinite conclusion being hased on them.47 Another possibilityhas, however, been advanced in explanation or partial explanationof the facts. It was shown last year by A. Loeb,48 working underthe inspiration of Embden, that acetoacetic acid can arise in theliver, not only from the oxidations of the higher fatty acids, butalso by synthesis from aceti6 acid itself. E. Friedmann49 showedthat this only occurs when the liver is rich in glycogen, a pointwhich has now been confirmed by G. Embden and A. Loeb,SO andit is clear that it is one of significance in connexion with theproblem we are considering. Friedmann suggests that acetoaceticacid is formed from acetic acid by condensation of the latter with47 W.R. Uloor, Eighth Inter. Cong. App. Chenz., 1912, XIX, 29 ; A . , i, 1014.4s Riochem. Zeitsch., 1912, 47, 118 ; A . , i, 130..N IIBid., 1913, 55, 436; A., i, 1276.Zeitsch. physiol. C h m , 1913, 88, 24ii ; A . , i, 1411204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.acetaldehyde to yield crotonic acid m an intermediate product,and J. Mochizuki51 has carried out experiments which seemindirectly to confirm this. Embden, however, shows reasons forbelieving that the simple equilibrium :CH3*CO-CHz*COzH + H20 -Z 2CH3*C02Hobtains. I n either case it is obvious that the removal of acetic acidfrom the liver cell would favour the breakdown of acetoacetic acid.Now acetylation is a process of which the body has been provedcapable, and the suggestion is that carbohydrate products mayundergo this process, and so encourage the progress of the abovereaction in the required direction.The facts offer a t least adefinite suggestion, and should encourage further research.Whether the successive removal of two carbon atoms which occursduring the course of P-oxidation in fatty acid chains really resultsin the production of acetic acid a t each step, which would makethe latter a very prominent metabolite, is yet to be proved ordisproved. If it were the case, the importance of the aboveequilibrium relation would be very great.Lipoids.Much attention has been given of late to the lipoids of thebrain. Towards the end of last year S.Frankel, P. Kirschbaum,and I(. Linnert 52 gave an account of the distribution of cholesterolin that organ, and J. I;. Smith and W. Mair53 have publishedelaborate analyses showing the proportions of various lipoids inthe humau brain a t different ages. Further valuable analyticaldata are contained in a paper by C. Serona and A. Palozzi.64Th3 pure chemistry of the cerebrosides 55 and phosphatides fromnervous tissues, although still suffering from some vagueness, bothas regards facts and nomenclature, is making good progress. I nparticular some careful work has been done on the cerebrosides(galactosides) .56 A. Lapworth has dealt successfully with thepurification of the most prominent among them-cerebrone-andhas thrown fresh light on the constitution of its basic constituent,sphingmine. The most important acid obtained on hydrolysis ofthe mixed cerebrosides from the brain is cerebronic acid, (G5HS0O3).This has been the subject of further study by Levene57 and his51 Biochem.Zeitsch,., 1913, 55, 443 ; A , , i, 1277.52 Ibid., 1912, 46, 253 ; A., i, 125.R g J . Path. Bnct., 1913, 17, 418 ; A . , i, 313.54 Arch. Farm. spcrin?., 1913, 15, 375; A., i, 1410.55 Ama. Report, 1908, 234.57 J. Biol. C'he?~z., 1912, 12, 389 ; A . , 1912,G, 1007; ibid., 1913, 14, 257; A . , i,Y'., 1913, 103, 1029.587PHYSIOLOGICAL CHEMISTRY. 205colleagues at the Rockefeller Institute. They have made i t nearlycertain that the substance is a normal a-hydroxypentacosoic acid.Another fatty acid, however, arises on hydrolysis of the cerebro-sides.This has been separated during the past year by R. Thier-felder,s8 P. A. Levene,S9 and 0. RosenheimFO all working indepen-dently. It arises from the moresoluble of the cerebrosides, and, if we accept Thudichum’s nomen-clature, from kerasin; Thierfelder, regarding it as a new acid, gaveit the name kerasinic acid. Levene, however, believes it to beidentical with lignoceric acid, and Rosenheim has come indepen-dently to the same conclusion. The last-named author61 hasdeveloped hi3 method of extracting the cerebrosides by means ofcold pyridine, which avoids any procedure likely to break downpreexisting complexes. He advances his results as yielding proofthat these substances (which he proposes to call galactosides) existfree and uncombined in the brain. With regard to the phosphatidesof nervous tissue we may note that J.P a r n a s 6 2 finds stearic acidto be the only saturated fatty acid contained in kephalin, whilstA. Baumann63 and M. H. Renal164 have independently shown thatits basic constituent is aminoethyl alcohol. A somewhat strikingcontribution t o the metabolic side of these substances is E. Salkow-ski’s65 finding that on giving kephalin by the mouth the amountof phosphatides in the brain is increased.Cholesterol has received a considerable amount of attentionduring the year. A t the riddle of its constitution Windaw andothers continue to work, but no very important new facts havecome to light, and I must not give space to the question.To thephysiology of cholesterol J. A. Gardner66 has made another con-tribution, this time in conjunction with P. E. Lander. Workingwith cats, they have obtained further evidence for the fact thatthe body deals in a highly conservative manner with its store ofcholesterol, that which is excreted in the bile being re-absorbed andutilised afresh. An interesting point is found in the probabilitythat the re-absorption occurs in the form of esters, a t any rate,when the diet is rich in carbohydrates. Addition of cholesterol tothe diet increases its amount in the blood, liver, and suprarenals,but not in the muscles, kidneys, or lungs, where the quantity is58 Zeitwh. physiol. Clem., 1913, 85, 35 ; A . , i, 747.5y J. Biol. Chem., 1913, 15, 359 ; A ., i, 1129.Trans. Internat. Congress of Med., Sect. 11, 626.61 Biochem. J., 1913, 1, 604.62 Biochem. Zeiilsch., 1913, 56, 1 7 ; A , , i, 1253.(iy Ibid., 1913, 54, 30 ; A , , i, 1041.R5 Ibid., 1913, 51, 407 ; A., i, 789.It has the formula CzaH4s02.Ibid., 1913, 55, 296 ; A., i, 1254.Biochem. J., 1913, 1, 576206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.very constaut. A special interest in this contiexion is attaclledto the suprarenals. L. Wacker and W. Hueck67 find a closeparalleliem between the amount of cholesterol in these glands andthat in the blood, a relation which is maintained in spite of thewide fluctuations induced by disease. Gardner's results are inaccordance with this, although he finds, as does Landau,68 thatin inanition there is accumulation in the blood, and almost acomplete disappearance from the suprarenala.Wacker and Hueckfind that the labile part of tissue cholesterol is that which existsas esters, and this (a suggestive point) is indicated by the workof others, including, I think, that of Gardner. F. RauderssQ haspublished very full analytical data concerning the cholesterol andcholesterol esters contained in the serum and blood corpuscles ofvarious animals. E. Schreiber and LBncird 7O stdate that oxychole-sterol is found in all organs of the body save the liver.I. Lifrschutz 71 confirms this statement, and gives evidence in supportof his belief that the substance undergoes further change in thelast-mentioned organ.The relations of cholesterol and the phosphatides t o immunityphenomena, although still a subject which inspires much work,cannot be treated in this report.I have space only to deal withone other research. A. Mayer and G. Schaeffer 72 have shown thatthe kind and amount of lipoids present in a given organ are charac-teristic for that organ. They speak of lipocytic constants andwhich main- fatty acid and cholesterolphosphorus fatty acids'indices such as the ratios:tain a constant mean value in most organs other than the muscles,and are independent of the spe'cies.C'W emist ry of R esp'ra t ion.Work on the pure chemistry of haemoglobin has made consider-able progress during the year, and most of those whw0 names weassociate with the work have published papers.R. Willstiitter and&I. Fischer 73 have obtained from blood pigment the aetioporphyrin(C,,H,N,), which had been previously obtained from chlorophyll,so that this substance constitutes a definite linking between the67 Arch. czpt. Puth. Phurm.. 1913, 71, 373 ; A . , i, 554.G8 Denitsch. mcd. Wochensch., 1913, 12, 1.7O Ibid., 1913, 49, 458 ; A . , i, 544.7l Ibid., 1913, 52, 206 ; A., i, 932.72 Cowpt. rend., 1913, 156, 487 ; 157, 156 ; A . , i, 424, 1017.73 Zeitsch. physiol. Chem., 1913, 87, 423 ; A., i, 1257.Biochem. Zeitcch., 1913, 55, 419 ; A., i, 1258PHYSIOLOGICAL CHEMISTRY. 207a-iiinial a d the plant pigment, but we are wariied by the authorsthat too much must not be made of the supposed close relationin their constitution. Important differences probably exist in theirmolecular structure.It is impossible to appraise properly in smallspace the work done in this domain. I must content myself withpointing out the interest and importance of the paper just men-tioned. It gives a large amount of information concerning thepresent position of the subject, as well as much fresh work.The physico-chemical and physiological properties of hcemoglobinand its relations with oxygen in the blood continue to receiveillumination at the hands of J. Barcroft74 and his co-workers. Asis well known from their work, the dissociation curve of oxyhzmo-globin, as it exists in the blood, is very different from that of apure solution, so potent is the influence of salts and of the carbonicacid in t-he former.A. V.Hill 75 and Barcroft 76 have published papers in which theobserved form of the blood dissociation curves receives extraordin-arily satisfactory explanation.The effect of variations in the hydrogen-ion concentration of theblood has proved to be of such practical importance that Barcrofthas felt the necessity of introducing a new nomenclature in con-nexion with it. When the hydrogen-ion concentration is normaland the dissociation curve also normal, it is proposed t o speakof the blood as mesectic. When, owing to a fall of acidity, thedissociation curve is displaced, more oxygen than normal beingtaken up a t any given tension, the blood is pleonectic. With arise of acidity the absorption of oxygen is proportionately less;then the blood is meionectic.The effect of variom conditions on the dissociation curve hasbeen fully studied.Severe exercise, for instance, producesmeionexy, even although the carbonic acid tension of the blood isreduced. This is because other acids formed in metabolism increasethe hydrogen-ion concentration. On the other hand, living a t highaltitudes may leave the blood mesectic, the lowered carbonic acidtension being then nicely compensated by the formation of otheracids. A high degree of meionexy, however, is produced by severeexercise under these conditions. The effect of moist heat, such asmay exist in factories, etc., is to produce an uncompensated lower-ing in the carbonic acid tension; the blood then becomes pleio-nectic.The results of these researches show that in circumstancesin which the blood is mesectic the subject feels in normal health,even although the blood may contain abnormal acids; whilst whenProc. physiol. SOC., 1913; J. Plzysiol., 45, slv, xlvi, xlvii; A , , i, 306.75 Biochcm. J., 1913, 7, 471 ; A., i, 1250.76 Ibid., 481 ; A , , i, 1250208 ANNUAL REPORTS ON THE PROGRESS OF CHEMIS'I'RT.i t is either pleionectic or meionectic the subject feels out of hisnormal condition, and betrays symptoms of the change which hastaken place. These considerations are likely to prove of no smallimportance in practical medicine. A study carried out on theclinical side by T. Lewis and in the laboratory by Barcroft77 andothers has already shown that clinical casa exist in which dyspnoeais a prominent symptom,but from which an equivalent cyanosis isabsent.The fundamental factor of these cases seems to be anincrease in the proportion of acids (exclusive of carbonic acid) tobases in the blood, and the symptoms are really an expression ofthe consequent meionexy.The nicety with which the hydrogen-ion concentration of theblood is regulated in normal circumstances is demonstrated by theresearches of Haldane and his co-workers.78 The kidney probablyplays the chief part in this adjustment.Whilst carbon dioxide as an acid determines the stability ofoxyhzemoglobin, it would seem, to judge from experiments, whichhave as yet been only briefly reported,'g that the presence of oxygenconversely diminishes the stability of carbonic acid compounds inthe blood.As a result of this relation, the velocity of evolutionof carbon dioxide in the lungs must be increased, and its relativetension reduced in the region of the tissues. Current work tendsto show more and more how exactly the chemical mechanisms ofthe blood are adjusted to give it the highest possible efficiency asa medium of gaseous exchange, and to indicate the great interestthat the case of hzmoglobin presents to the physical chemist.Many papers have appeared dealing with tissue respiration,especially in connexion with the nervous system. H. M. Vernon,*Oand, also, independently, F. Battelli and 1,. Stern,*1 have studiedthe depressing action of anzesthetics on the tissues oxydasm, andtheir results have an important bearing on the nature of narcosis.F. G.Alexander and S. Cserna82 find that the brain displays aconsiderable gaseous metabolism, its oxygen consumption beingof the order of 0.36 C.C. per gram per minute. Narcosis depressesthis metabolism greatly. The action of various narcotics differs,however, in detail, and any theory of anzsthesia must take account77 T. Lewis, J. H. Ryffel, C. G. L. Wolf, T. Cotton, G . L. Evans, and J. Barcroft,78 J. M. H. Campbell, C. E. Douglas, J. S. Halclane, and F. G. Hobson,59 J. Christiansen, C. G. Douglas, and J. S. Haldane, Proc. physiol. Soc., 1913, ii ;8o Biochem. Zcitsch., 1913, 47, 374; A . , i, 220.81 Ibid., 1913, 52, 226, 253 ; A., i, 929.8L Ibid., 1913, 53, 100; A., i, 1011.Proc. ph.ysio1.Soc., 1913, liii-liv ; J. Ph,ysiol., 46 ; A., i, 1022.J. Physiol., 1913, 46, 301 ; A., i, 1011.J. Physiol., 47 ; A., i, 1403PHYSIOLOGICAL CHEMISTRY. 209of such differences. S. Tasliiro 83 claims t o have measured the carbondioxide output of nerve-fibres, which is also reduced by anzsthetics.H. E. Roaf 8* has shown that during decerebrate rigidity theoxygen intake of the animal is only slightly greater than when themuscles are flaccid; whilst K. Hannemann *5 finds that removal ofthe brain markedly increases (in frogs) the total gaseous meta-bolism.Miscellaneous Papers of Interest.Fumtiorts of the Thyroid c;-'la?ztE.-Space has not allowed me todeal in a special section with the subject of internal secretions. Ihope, however, to illustrate the work of the year in this domainby referring here to two interesting researches.The first throwslight from a somewhat new experimental point of view on theimportance of the thyroid gland as a regulator of the bodily func-tions. G. F. Mansfeld, in conjunction with Fr. Muller, has shownthat the increased nitrogenous metabolism which is induced innormal animals by deficiency of oxygen does not occur in animalsdeprived of their thyroid gland. Other phenomena depending onthe same deficiency ar0 now shown by further work of the first-named author86 to be absent when the gland is absent. Normalanimals when kept a t high altitudes are well known to develop aconsiderable increase in the number of red corpuscles in theirblood. In Mansfeld's experiments (on rabbits) the control animalsshowed an increase of some 20 per cent.when removed from sea-level to a height of 1000 m. The phenomenon was wholly absent inthe case of thyroidectomised animals, the blood of which reactedindeed in an opposite sense, and showed a large decrease ofcorpuscles. I n the absence of the gland oxygen deficiency wouldseem actually to inhibit red cell formation. As a result of itsremoval the blood also regenerates more slowly and less completelyafter the administration of poisons which destroy red corpuscles.These results suggested an attempt to get an increase in corpusclesby injecting thyroid extrack into normal animals, and in Mans-feld's experiments the continued administration of such extractsdid, as a matter of fact, cause an increase which in some casesamounted to 180 per cent.Next it was shown (by Mansfeld and E.Hamburger) that thefamiliar rise in nitrogen excretion which occurs shortly beforedeath from starvation was greatly reduced as the result of previoustliyroidectomy. Finally, it was found that cliloroform and kindred8:: Amer. J, Physiol., 1913, 32, 107 ; A., i, 930.85 Biochew. Zeitsch., 1913, 53, 8 0 ; A., i, 1011.86 Pjliiger's Archiv, 1913, 152, 23, 50, 56.Quart. J, expt. Physiol., 1913, 6 , 393 ; A . , i , 1124.REP.-VOL. X. 210 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.narcotics no longer induce an increased tissue breakdown when thegland is absent. These previously familiar effects of high altitudes,starvation and chloroform poisoning, are not, therefore, directeffects; they arise indirectly from the disturbance of thyroidfunction.The Secretion of Cerebro-spinal Fluid.-W. E. Dixon and W. D.Halliburton87 have now brought to a conclusion a lengthy andimportant research dealing with the cerebro-spinal fluid. The firstpaper, which is now published, deals with the secretion of thatfluid. The process provides another instance of glandular activitycontrolled by chemical influences. The secretory mechanism ismade up of the cubical epithelium cells which cover the choroidplexuses of the brain, called collectively, by Mott, the choroidgland, Dixon and Halliburton find that the stimulating hormonemay be extracted from the gland tissue itself, but as extracts ofthe brain are equally effective the substance would seem to takeits real origin from the metabolism of tlhe latter organ. I n cases ofgeneral paralysis and brain softening the hormone is found in thecerebro-spinal fluid itself, although not in the normal fluid. Carbondioxide also acts in stimulating an increased flow, and the sugges-tion seems t o be that the whole mechanism is adjusted to removewaste products, the flow of fluid being proportional to the meta-bolism in the brain.The Secretion of Pancreatic Juice.-A fact of no small interestcoines t o light in a research due to A. Hustin.88 If the isolatedpancreas is perfused with oxygenated Locke's fluid, the glandremains long capable of secretion, but no secretion occurs. Addi-tion of secretion to the fluid is quite without effect. When againthe gland is perfused-with blood alone, secretion of juice is alsoabsent, but it becomes profuse when secretion is added to the blood.The juice so obtained is similar to that obtained from a fistula,containing all the normal ferments. The experiments of the authorthrow no very clear light on what constituent or constituents ofthe blood may be essential to the secretion. Serum containingsecretion does not activate the gland, a fact which seems to militateagainst any simple assumption concerning the nature of theinfluence of the blood.F. G. HOPKINS.87 J. Physiol., 1913, 47, 215 ; A., i, 1413.g8 Ann. et Bull. Soc. roy. dc sc. m6d. et nnt. Bmleclles, 70, 178 ; from Zentrbr.Bioeh. ii. Biophysic, xv, 83

ISSN:0365-6217    

DOI:10.1039/AR9131000190

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.WHILST nothing of very exceptional importance has to be recordedfor the year 1913, activity in research has been well maintainedand much useful work has been accomplished, especially in con-izexion with soil chemistry and bacteriology. Many investigations,too, have been made which relate to the composition of differentplants. These, however, deal as a rule with special cases, andcannot usefully be discussed as a whole.Amongst publications which have appeared during the year maybe mentioned “The Fertility of the Soil” by E. J. Russell, asecond edition of E. A. Mitscherlich’s “Bodenkunde,” and a new( ( Journal of Agricultural Research,” published by the UuitedStates Department of Agriculture, t o take the place of the variousbulletins hitherto issued by the different bureaus.The A tmoqhere.The amount of combined nitrogen present in the atmosphere ofdifferent places, as indicated by the amounts brought down by therain, and, as regards ammonia, the amounts absorbed by an acidsolution of known area, has received a good deal of attentionduring the last few years.These recent results show that theaverage amount of nitrogen, in the forms of ammonia and nitricacid, which the rain contributes to the soil is rather less thanfour pounds per acre per annum, which agrees very nearly with theaverage amount found a t Rothamsted during the last thirty years.The results obtained at different places vary, however, considerably.I n Groningen the total nitrogen amounts t o 2.6 kilos., whilst in NewZealand, near the coast, the amount is only 0.7 kilos.per acre.The greatat differences ar0 in the nitrogen in the form ofammonia, which varies from 2’0 kilos. in Groningen to only 0.3 kilos.in New Zealand.It is evident from all these results that as a source of combinednitrogen the rain is of no great importance to crops-an averageyield of wheat or barley will contain eight times as much nitrogen.The questiun possesses interest, however, in its relation to thenitrogen of the soil, since we cannot yet say whether rain and dew,P 2 21212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.apart from smoke contamination, are really supplying additionaliiitrogeii to the soil, or merely restoring soiiie of the ammoniapreviously lost.Recent analyses of rain-water 1 obtained from the Outer Hebridesand from Iceland show that the air in the north of Lewis and inIceland contains considerably less combined nitrogen than eventhe low amount found in New Zealand.A t Vifilsotodum, Iceland,the total nitrogen only amounted to about 0.45 kilos. per acre perannum, mostly in the form of ammonia; whilst a t the Butt ofLewis the total nitrogen is less than 0.35 kilos., the amounts ofnitrogen in the two forms being about equal. These results, inconjunction with those obtained at other places near the sea,indicate that the sea, a t any rate, does not contribute, as has beensuggested, any very appreciable amount of ammonia to the air,even in tropical countries.So that, apart from local smoke con-tamination, it seems probable that atmospheric ammonia must bemainly derived from the soil. We have evidence that the fairlyheavy soil at Rothamsted loses ammonia for some weeks after theapplication of ammonium salts, and it is possible that some soilsare more or less continuously giving up t o the air small portionsof the ammonia produced from organic residues. Some soils maybe expected to lose more ammonia than is returned in the rain,whilst others may gain in this manner more than they lose.Chlorides and sulpha'tes have also been estimated in numeroussamples of rain collected in Russia,2 and a large number of morecomprehensive analyses of rain-water have been made in the neigh-bourhood of Leeds, in connexion with an investigation on theinjury to vegetation caused by atmospheric impurities near anindustrial town.3 The results show that the amount of sulphur,which is mainly in the form of sulphates, is the most characteristicindication of the extent of contamination with coal smoke.At adistance of seven miles from the city the lowest amount of sulphur(as sulphur trioxide) was 58 kilos. per acre per annuin, or aboutseven times the amount found a t Itothamsted. On the other hand,the amounts of total nitrogen are not very high, being, a t adistance of seven miles, only about 3 kilos. per acre, or, if someabnormally high results are excluded, a good deal less.Soils.Whilst much attention has been given to the mechanical andchemical composition, that is to say, the separation of soils intoN.H. J. Miller, J. Scot. Met. Soc., 1913, [iii], 16, 141 ; A., 1914, i, 128.P. Kossowitsch, J. expar. Landw., 1913,14, 181 ; J. Wituynj, ibid., 1911,12, 20 ;C. Crowther and D. N. Steuart, J. Agric. Sci., 1913, 5, 391.A . , 1911, ii, 432AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 213particles of different sizes, and the estimation of the variouselements which they contain, the mineralogical composition whichmust influence both the physical and chemical properties of soils,has hitherto been rather neglected, notwithstanding recent improve-ments in methods, especially those dealing with the optical proper-ties of minerals.Recently a considerable amount of work has been done by theUnited States Bureau of Soils,4 and the methods which have beenfound most suitable have been brought together and published,along with a description of soil-forming minerals.Although it isprobable that all minerals occur sometimes, the great majoritymust be exceptional, so that the number of minerals to be lookedfor is comparatively limited. Minerals, such as leucite, which arereadily decomposed would only be found near the places of theirorigin. The usual potassium minerals which occur in soils aremuscovite, which is the most resistant, and probably of only slightvalue as a source of potassium for plants; biotite, which is theleast resistant ; orthoclase and microline The common calciumminerals ar0 epidote, which was found in most soils, hornblende,plagioclase, and garnet.The presence of quartz crystals probablyindicates a limestone origin.A study of the effects of frost on soil colloids5 showed that inthe case of soils which would be expected to be only slightly influ-enced, the soil particles become more finely divided, so that hygro-scopicity is increased, whilst in the case of soils in which thecolloids ar0 appreciably coagulated by frost the hygroscopicity isdiminished.The cause of the plasticity of clay,‘; about which opinions havebeen very conflicting, has been shown to be due to the presenceof organic aluminium compounds. h solution of humus, to whichalumina was added in order to clarify it, on being filtered andevaporated, yielded a glue-like substance, which, when decomposedwith hot concentrated hydrochloric acid, was found to containaluminium.Considerable further progress has been made in isolating theorganic constituents of soils,a and the number of compounds foundnow amounts to thirty-five, including thirteen acids, nine bases,three sugars, two alcohols, and two aldehydes, besides a hydro-carbon, a glyceride, a resin ester, sulphur and phosphorus com-pounds, and an acid anhydride. Nost of the remaining, stillW.J. McCaugliey and W. H. Pry, U.S. Dept. Agric. Bweau of Soils Bull.No. 91 ; McCaughey, J. Ind. h’7~g. Chem., 1913, 5, 562; A., i, 1035.P. Ehrcnberg and G. Freiherr von Roiiiberg, J. Lnndzu., 1913, 61, 73.J. Stewart, Eighth Inter. Cong. Appl. Chem., 1912, XV, 266.7 E. C. Shorey, U.S.Dcpt. Agric. Bureau of Soils Btdl. No. 88, 1913214 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.unexplored, portion of the organic matter is believed to consistmainly of resinous substances.Owing to the rapid decomposition of the nucleic acids even bydilute mineral acids at the ordinary temperature, it is a difficultmatter to distinguish between the organic and the inorganicphosphorus of soils, and impossible to distinguish quantitatively.When, however, tE.4 acid filtrate is immediately treated withsodium acetate and a large amount of alcohol, some of the nucleicacid can be recovered, and in this manner its presence has beendetected in a number of soils. All of the organic phosphorus isprobably in the form of substituted phmphoric acids. In organicsulphur compounds, on the other hand, the sulphur takes theplace of oxygen, and when they are decomposed, sulphur, or asulphide, is formed.The only sulphur compound so far isolatedis trithiobenzaldehyde.It must be borne in mind that whilst the organic substanceswhich have been isolated are extracted from soils by dilute alkali,they do not form a part of the humus precipitate obtained byadding acid, which, after all, is the most interesting portion of theorganic matter of soils, but are obtained from the filtrate from thehumic acid.During the last few years doubh have been expressed as tothe existence of humic acids.* It is maintained that the action ofpeat on tricalcium phosphate, from which it liberates phosphoricacid, is not necessarily due to the presence of free acid in peat,and that it may be accounted for by the absorption of bases bycolloids.Similarly, the action of peat in liberating iodine from asolution of potassium iodide and iodate is also attributed to theabsorption of the base by colloids. As regards the inversion ofsucrose by peat and the liberation of hydrogen when peat is boiledwith water in presence of powdered iron, both these actions areattributed to the action of the hot water, assisted by the saltspresent in t.he peat.The absorption of bases by peat colloids is attributed mainly tothe cell-wall of the Sphagnum, so that according to this suppositionthe substances known as humic acid, which are precipitated byacids from alkaline extracts of peat or soils, are comparativelyunimportant.The question of the existence of humic acids seems now to bedefinitely settled9 in favour of the old theory, which dates from thetime of Sprengel, by a series of experiments made with the‘‘ matiire noire ” itself, instead of with peat, thus avoiding all8 E.Gully, Mitt. k. Bap.. Moorkulturanst., 1913, Heft 5, 85 ; A . , i, 1353.9 P. Ehrenberg and F. Bahr, J. Landw., 1913, 61, 427; A., 1914, i, 50AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 215complications duo to the various other substances, whether colloidsor not, present in peat. This, of course, is in any case desirable,and especially so when physical methods, such as conductivitymeasurements, have to be employed.The crude ammonium humate employed in these experimentswilg prepared in the usual manner from peat.The solution wasfirst filtered through collodion, which allows the humate to passthrough fairly rapidly, whilst a colloidal substance is retained.10After conce'ntrating the filtrate by evaporation a t 5 5 O underreduced pressure, the humic acid is precipitated with a, smallamount of hydrochloric acid, filtered through collodion, washed,and finally freed from electrolytes by means of a Zsigmondydialyser. Eumic acid prepared in this manner readily dissolvesin alkali, even after it has been heated to looo or l l O o .It was found, in the first place, that whilst ammonium humatehas no definite dissociation pressure, its behaviour indicates thatthe ammonia is not merely adsorbed, but that it is held by thewhole of the solid humic substance.The behaviour of the saltclosely resembles that of ammonium guaiaconate, except that thelatter gives up its ammonia very much more readily than thehumate. This is in accordance with the view that humic acid isnot merely a phenolic compound, but a true acid.Further experiments on the absorption of ammonia and sulphurdioxide respectively showed that ammonia is absorbed in fargreater quantity than sulphur dioxide, the former being chemicallycombined, whilst the latter is merely adsorbed.The neutralisation point of humic acid was found by adding asuspension of the acid in water to dilute sodium hydroxide, andestimating the conductivity. The results indicated with sufficientclearness an equivalent weight of 230.It was further shown thatthe acid is probably tribasic, and, at any rate, not more thantetrabasic. So that the molecular weight of the acid would beeither 690 or 920. It was not, however, found possible to preparesalts of definite composition. When calcium chloride is added to asolution of sodium humate, most of the humic acid is precipitatedas calcium salt. The analysis of two different preparations gave,however, very low results for calcium ; in one case about 20 per cent.,and in the other nearly 30 per cent. lower than the theoreticalamount. This accords with the idea that humates are solid solu-tions, and if this view is correct, the fact that a calcium salt hasbeen obtained containing within 2 per cent.of the theoreticalamount of calcium must be attributed to chance.Pure humic acid was found to decompose about one-sixth of itslo S. Odh, Ber., 1912, 445, 651 ; A , , 1912, i, 336216 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.weight of tricalcium phosphate. Peat containing 5 or 6 per cent.of humic acid would, accordingly, liberate the phosphoric acid ofabout 1 per cent. of tricalcium phosphate.The effects of the partial sterilisation of soils by moderateheating, and by various antiseptics, to which reference haa beenmade in previous reports, have been further investigated,ll andsome additional evidence has been obtained that the beneficialresults are due to the destruction of organisms which in some wayhinder the multiplication of certain desirable bacteria.Briefly, thechief results are as follows: The immediate effect of heating soilsto 55-60°, or of the application of antiseptics, is the destructionof the large organisms (protozoa, etc.) and of nitrifying organisms,whilst the organisms which produce ammonia, and denitrifyingorganisms, remain. Ammonia is a t once produced, and goes onincreasing in amount when the soils are kept. This is shown to bedue to a rapid increase in the number of ammonifying organisms;there is no evidence that these organisms are in any way stimu-lated. The increase in numbers is still more marked when theconditions are rendered more favourable by increased temperatureand by an increased supply of moisture. This is an importantpoint, because all attempts t o obtain a regular increase in thenumber of organisms by making the conditions of temperature andmoisture more f avourable have been unsuccessful when normal,unsterilised soils were employed.I n normal soils the activity ofthe bacteria will, of course, be increased, but their numbers will bekept down, and a t times even reduced, by the coincident increasein the number of large organisms.The inoculation of partly sterilised soils with untreated soilrestores the less favourable conditions, and again reduces thenumber of bacteria. I n treated soils the increase in the number ofammonifying bacteria is sometimes accompanied by an increaseof ammonia; in some cases ammonia production ceases, whilstthe organisms continue to increase in numbers.The cessationof ammonia production, which may be brought about by addingammonia, is due to a retarding action of ammonia on the activity,but not on the multiplication of the bacteria.Finally, i t is shown that soils are temporarily benefited inprecisely the same manner by being kept for some time a t atemperature of only 3 5 O , and also by very low temperatures. Theslow return of the soils, thus treated, to their original statesupports the view that i t is t o the large organisms, rather than tothe bacteria, that the beneficial effects of partial sterilisation mustbe due.11 E. J. Itussell and H. 13. Hutchinson, J. Agric. Xci., 1913, 5, 248AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 21’1Whatever slight physical or chemical changes soils may undergowhen treated in the manner adopted in theae experiments, i t seemsevident that they cannot in any way account for the resultsobtained, which seem clearly t o point to the destruction of inimicalorganisms as the cause of the increacsed bacterial changes in thesoils.The way in which these large organisms check the multiplicationof the bacteria is not yet evident.It is suggested that they feedon the bacteria; or that in some way they enclose, or lock up,the food on which the bacteria depend. It is perhaps more likelythat their action consists in appropriating too large a share ofthe limited supply of oxygen in the soil. This, however, will, nodoubt, be made clear by a better knowledge of the numbers andhabits of the protozoa and other large organisms present in soils,and now being investigated.12 I n the meantdme the results referredto constitute a distinct advance in our knowledge of the mutualrelations of the different groups of soil organisms.Antiseptics, such as arsenic compounds,13 when applied to thesoil in small amounts, seem to act similarly t o volatile antiseptim,giving rise to increased ammonification and nitrification.Of thedifferent arsenic compounds employed, lead arsenate was found tobe the most stimulating and the least injurious, whilst Paris greenproved t o be the least stimulating and the most toxic. It wasfurther shown that with fifty per million of arsenic, soluble inwater, in the soil, both ammonification and nitrification canproceed vigorously It is not shown whether these results are dueonly to the destruction of large organisms, or whether there is, inaddition, a stimulating action on the bacteria.In connexion with the partial sterilisation of soils some interest-ing results have been obtained which throw light on the action oflime on soil organisms.14 It has been shown that the increasein the number of bacteria, produced by the application of smallamounts of lime,15 is coincident with a destruction of the largeorganisms; and that lime, i n the amounts employed, has an anti-septic action intermediate between the effects produced by heatingand by volatile antiseptics respectively. The advantages of limeover volatile sntiseptics are evident, since in addition t o immediateantiseptic and chemical action, it leaves an essential constituent inthe soil after its conversion into carbonate.The old practice ofchalking will, in any case, have to be revived, sooner or later, andl? T. Gootley, Proc. Roy. Sue. 1913, By 86, 427.l4 H. B. Hutchinson, J. Agric. Xci., 1913, 5, 320.l5 H. Fischer, Landw. Yersuchs-Stat., 1909, 70, 335 ; A., 1909, i, 602.J. E. Greaves, Biochent. Bull., 1913, 3, 1218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.if lime should prove to be a suitable antiseptic under practicalconditions it could easily be applied, a t suitable intervals, or rtlter-nately with chalk.Vegetation experiments in which 0.5 per cent. of lime was addedto arable soil, already containing calcium carbonate, showed a remarkable increase.With rich garden soil the first crop was d epressed, and the benefit of lime was only shown by the second crop,which was increased very considerably. The temporary injury inthe case of garden soil is probably similar to what has been observedwith peaty soils. It has been attributed, on the one hand, to in-creased oxidation of organic matter and the production of toxicsubstances,16 such as oxalic acid (which, as time goes on, would beconverted into carbonates); and, on the other hand, to a reductionof nitrates to nitrites in amounts sufficient to be toxic.17The chemical effects of heating soils to higher temperatures, suchas 135O and 150°, have also been investigated. At the lower tem-perature18 it was found that not only ammonia and amines areliberated, but that there is an increase in all the water-solublesubstances, and an increase in acidity.Arginine, xanthine, hypexanthine, guanine, cytosine, and dihydroxystearic acid are formed,or, if already present, their amounts are increased. Whilst bothbeneficial and injurious substances are produced, the latter havea predominating effect, and must be got rid of before the benefitsof heating can become evident.Soils which were heated t o 150°19 and dialysed were found tocontain much more soluble matter than before, and vegetationexperiments showed that more growth was obtained, and moremineral matter assimilated in the heated soil. Similar results,although less marked, were obtained by drying the soil a t 95-98Oin a vacuum.Increased assimilation of mineral matter (potassiumand phosphorus) was also observed in the case of tomatoes grownin partly sterilised soil which had been dunged.20 I n this case thel6 G. A. Ritter, Bied. Zentr., 1913, 42, 239 ; A., i, 812.A. Densch, Landw. Jahrb., 1913, 44, 331.0. Schreinor and E. 0. Lathrop, U.S. Dept. Agric. Bureau Of Soils Bull. 89,1912 ; Lathrop, Eighth Inter. Cmg. Alrpl. Chem., XV, 147; A . , i, 1036. Theauthors' statement that changes in soils brought about by the action of heat werefirst observed by Frank in 1888 is not quite correct. Warington previously showedthat aqueous extracts of heated soils contain greatly increased amounts of organicmatter (T., 1883, 41, 356), and that nitrates can be completely destroyed when soilsare heated in a moist condition (ibid., 354).Pitsch (Landw. Tersuchs-Stat., 1887,34, 217) showed that ammonia is produced wheu soils are heated.Iu J. Konig, J. Hasenbaumer, and K. Glenk, Lnndw. Ters?Lchs-Std., 1913, 79-80,491 ; A., i, 578.E. J. Russell and F. R. Petherbridge, J. Agric. ScL, 1913, 5, 248AGRICUL~URAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 219soil was only heated to 5 5 O and 98O, or treated with volatileantiseptics.In connexioil with. the question of the losses of ammonia fromsoils, a number of experiments have been made, in which differentkinds of soils, to which solutions of ammonium carbonate wereadded, were kept in closed vessels through which a rapid currentof air was passed, and the amount of ammonia which was given offwaa estimated.21 The results obtained when soil and ammoniumcarbonate alone were employed accorded with what would beexpected from the characters of the soils.That is to say, the soilscontaining a good deal of humus and clay retained the greatestamount of ammonia. When, however, calcium carbonate wasadded, different results were obtained in each case. The absorptivepower of the most retentive soil, which contained the greatestamount of organic matter and clay, and was also the most acid,was diminished by the presence of calcium carbonate, and a similarresult was obtained with the least retentive soil, which was onlyslightly acid, and contained less than 1 per cent. of organic matterand less than 4 per cent.of clay. On the other hand, two othersoils, the one very similar to the last-mentioned, and the othercontaining a, fair amount of humus and more clay, were bothbenefited, as regards absorptive power, by addition of calciumcarbonate. Further experiments showed that the effect of calciumcarbonate may not only be quite different with different soils, butthat it is also influenced by the amount of ammonium carbonatepresent. Those soils in which calcium carbonate increased the lossof ammonia when small amounts of ammonium carbonate wereapplied, diminished the losses when larger amounts were present.The increased absorptive power in presence of calcium carbonateis attributed to the production of calcium zeolites. Whether afavourable effect will be obtained when small amounts of ammon-ium carbonate are present, or only with larger amounts, seemsto depend on th0 amount of available potassium which the soilcontains.Ammonificatiolt, Nitrification, and Denitrification.A new denitrifying organism, Denitrobacterium thermophilum,has been obtained from soil which produces vigorous growth at60-65O, and decomposes nitrates, with liberation of nitrogen, bothfrom the nitrates and from the nitrogenous matter of the broth.The nitrogen of nitrates is partly converted into oxidea ofnitrogen.2221 0.Leminermanii and L. Fresenins, Landw. Jnhrb., 191 3, 45, 127.22 A. Ambroi, Cents.. Bakt. Par., 1913, ii, 37, 3 ; A., i, 568220 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.comparison of the results obtained in ammonification experi-ments in soil and in solutions indicated that the more useful indica-tions are obtained in solutions.23 I n experiments in solutions,under aerobic conditions, the amount of substance employed seemsto be without influence on the rate of ammonification. Ugderanaerobic conditions ammonification is retarded owing perhaps toan accumulation of injurious metabolic products.Whilst in theinitial stages of the process, in shallow layers of liquids, it seemspossible that aerobic and anaerobic organisms may be of equalimportance, i t is considered that aerobic organisms may predomin-ate more in the final stages of ammonification. Blood and hornmeal decompose more rapidly in soil than in solutions, exceptwhen deep layers of soil are compared with shallow layers ofsolution. Aeration would therefore seem to be one of the chiefconditions on which ammonification depends.An interesting series of experiments has been described on theammonification of dried blood in soils, as effected by antagonismbetween anionsS24 Soil to which 2 per cent.of dried blood and theoptimum amount of water were added, together with some salt insufficient quantity to be toxic and varying amounts of some othersalt, were kept a t 28-30° for four days, and the amount ofammonia which was produced estimated. It was found that anta-gonism, as indicated by ita effects on ammonification, exists betweensodium chloride and sodium sulphate, between sodium chloride andcarbonate, and between sodium sulphate and carbonate.Thestrongest antagonism is between sodium carbonate and chloride ;the weakest between sodium chloride and sodium sulphate. Whenthe actual amounts are considered, the greatest antagonism wasobserved when the soil contained 0.2 per cent. of sodium chlorideand 0.7 per cent. of sodium carbonate. Under the latter conditions70.7 milligrams of nitrogen as ammonia warns obtained, whilst withdecreasing amounts of sodium carbonate the amount of nitrogenas ammonia fell rapidly to 37.8 milligrams with 0.2 per cent.The results are of considerable interest, both theoretical andpractical, and suggest possibilities in reclaiming the large areas of“alkali” soils. The methods of flooding and draining such soilsis not only costly but wasteful, since the water carries away plantfood along with the toxic salts.The difficulty may possibly beovercome by selecting plants which resist the action of the alkali,and aiding them by the application of suitable amounts of saltswhich are antagonistic to those already present.The recent observations, in Colorado, of great accumulations of23 F. Lohnis and 13. H. Green, Ce?~tr. Bakt. PUT., 1913, ii, 37, 534 ; A., i, 797.24 C. B. Lipman, ibid., 1913, ii, 36, 382 ; A., i, 238AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 221nitrates in certain alkali soils-so great as to cause the destructionof trees-seems now to be satisfactorily accounted for withoutassuming the intervention of abnormally active nitrogen-fixing andnitrifying organisms.As regards nitrification, the results of experi-ments with arid soils in Utah25 showed that, with suitable additionof water, nitrification was considerably less active than in Rotham-sted soils.I n arid soils the nitrates are invariably accompanied by othersalts, such as calcium, sodium, and magnesium chlorides andsulphates; and as an examination of the results obtained inColorado shows that the amounts of chlorides rise and fall with thenitrates, i t may be safely assumed that the nitrates and the chlorideshave a common origin, both being derived from accumulations inthe subsoil, deposited in remote times.It has been observed that a year or 80 before alkali soils becamesterile, luxuriant crops are obtained owing to an upward movementof nitrates.Later on the salts become so concentrated that theplants are killed.The large yields obtained on arid soils, notwithstanding the smallamount of organic nitrogen they contain, has been attributed tothe fm’t that the humus is more nitrogenous than in humid soils.It is, however, considered more probable that the fertility is dueto the deposits of nitrates. It is sometimes found that owing tothe nitrates of the subsoil being taken up by deep-rooted plants,and the ploughing in af the straw, the surface soil of cultivatedarid land becomes richer in organic matter than the adjacent,uncultivated soils.I n the course of an-investigation on the amounts of nitrates inRothamsted soils about thirty years ago it was shown that, underotherwise similar conditions, soils and subsoils down to a depth ofnine feet contained very much more nitrogen as nitrates where aleguminous crop had been grown than with a gramineous crop.The conclusion was drawn that the growth and the crop-residues ofleguminous plants were more f avourable to the development ofnitrifying organisms than that of gramineous plants.26Recent experiments on nitrification in surface soils taken fromfields on which lucerne and timothy had been grown showed thatnitrification was more rapid in lucerne soil than in timothy soil,not only in the case of soils on which the crops had been growncontinuously, but; on soils which had been left fallow for twoyears.27 The greater production of nitrates in the lucerne soil was25 R.Stewart, Cent?.. Bakt. Par., 1913, ii, 37, 477.26 J. B. Lams and J. H. Gilbert, T., 1885, 47, 380.27 T. L. Lyon and J. A. Bizzell, Centr. Bakt. Par., 1913, ii, 37, 161222 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.not due to the presence of a more highly nitrogenous crop residue,because the rate of nitrification remained in the same order whenboth soils contained about the same amounts of nitrogen in theform of dried blood. Whilst addition of lime considerably increasedthe amounts of nitrates formed, the leguminous soil still showedan excess over the timothy soil. I n what way nitrification ispromoted by the growth of a leguminous crop remains to beascertained.As regards the numbers of bacteria, without reference to thekinds, present a t different depths of the same soil under differentcrops, and in different kinds of soils,28 a good deal depends on themechanical composition, and consequently the aeration.Thegreatest number occurs in the upper four inches, below which thereis a more or less gradual decrease in numbers down to five feet.I n one case samples were taken down to fifteen feet; a t that depththe soii contained about 250 bacteria per gram. Considerablenumbers of bacteria were found a t much lower depths in loess soilthan in drift soil. The greatest fall in numbers, from the surfacedownwards, occurred within th0 first eight or ten inches. When thesurface soils of different kinds are compared it is seen that loesssoil contains the largest number of bacteria, and woodlandsoil the fewest.The latter result accords with previous investi-ga tions.The most interesting of the results are those relating to differentareas of t h e same soil under various crops. It was found that arotation of crops increased the number of bacteria as comparedwith continuous cropping; and that in the top depth of four inchesthere were more bacteria with a threeyear than with a two-yearrotation. On the other hand, with a four-year rotation thenumbers were lower than those of any plots except those undercontinuous clover and maize, and a two-year rotation in which ryewas ploughed in. With continuous clover there were fewer bacteriain the top four icches than with continuous maize; at lower depthsthe differences were only slight.Whilst it cannot be said that these results in any way supportthe ones previously referred to, they are not necessarily opposed,because hsre the bacteria as a whole are dealt with.The one seriesof experiments deals with the activity of one group of bacteria;the other with the numbers of bacteria generally.The variations in the numbers of bacteria cannot be accountedfor by variations in the moisture and in the amounts of nitrogenpresent, both of which were estimated in each case. It is suggestedthat aeration may be the chief factor, or that toxic substances are2R P. E. Brown, Centr. Bnkt. Par., 1913, 5, 37, 497AGRICULTURAL CHEMISTRY AND VEGETAELE PHYSIOLOGY. 223produced by the plants. The former explanation seems to be themore probable-until toxins have been detected.A biological investigation of different kinds of peat in Den-mark,29 the one a raw peat covered with heather and containing1 to 1.5 per cent.of nitrogen, the other from more humified peatland, employed for grazing, which contained about 3 per cent. ofnitrogen, showed very considerable differences in bacterial activity.The heather peat ((( Hochmoor ”) waa found to possess compara-tively high denitrifying power, whilst the putrefactive andmannito’l decomposing bacteria showed only slight activity, andthe cellulose decomposing bacteria extremely slight activity. Nitri-fying organisms were not found. The grass peat, on the otherhand, induced vigorous denitrification, nitrification, decompositionof peptone and mannitol, and a feeble decomposition of cellulose.As regards the production of ammonia from the amino-acidspresent in soils, a series of experiments was undertaken to ascertainthe relative rate a t which ammonia is formed, and also whetherthe conversion into ammonia is quantitative.30 Known amounts ofthe various compounds were intimately mixed with definite amountsof soil, and the ammonia estimated after keeping the mixtures forsome days a t 22-27O in closed vessels.The highest amount ofammonia was obtained from glycine (81.03 per cent.) ; asparaginegave 77.47 per cent., alanine 75.58, aspartic acid 72.74, glutamicacid 72-19 per cent., whilst tyrosine, leucine, and phenylalaninegave respectively 59.65, 59.62, and 54.31 per cent.Whether the whole of the nitrogen of amino-acids can beconverted into ammonia remains uncertain ; some of the ammoniamay be nitrified. It is, however, evident that these compoundsreadily lose nitrogen in the form of ammonia, and that the rate ofammonification is influenced by the constitution of the differentcompounds.The ammonification of organic nitrogen seems to be retardedin solutions which are subjected to the influence of P- and y-rayssl;the activity of denitrifying organisms was also found to be con-siderably diminished, whilst the development of the bacteria wasnot affected.Fixation of elementary nitrogen by Azotobacter Chroococcum wasfound to be distinctly increased when the air was activated bypitchblende, somewhat better results being obtained with weakthan with stronger radioactive intensity.29 H.R. Christensen, Centr. Bakt. Par., 1913, ii, 37, 414.3o S. L. Jodidi, Eighth Inter. Cong. Appl. Chem., 1912, XXVI, 119 ; A . , i, 1036.31 J. Stoklasa, Compt. rend., 1913, 157, 879; A., i, 1421224 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.P h t Nutrl;tiotL.In a previous report (1910) reference was made to the theorythat the fertility of a soil depends mainly on the capacity of thesoil t o supply adequate amounts of water to the crop, and that theaction of manures consists not in supplying plant food, but inprecipitating toxins secreted by the plant.32 There seems to besome doubt as to whether the publication in which this theoryappeared was intended to be taken quite literally, or whetherit was not, in part, a rather drastic way of discouraging thepurchase of the more useless mixed manures offered to unwaryagriculturists. However that may be, one result is an importantand interesting investigation,33 which re-establishes the position ofmanures as essential in the nutrition of plants, and a t the sametime throws light on other conditions which affect the developmentof roots.In the first place, water culture experiments were made withwheat and barley in which the plants were grown in extracts ofsoil from some of the differently manured plots of the permanentwheat and barley fields a t Rothamsted; the solutions each receivedthe same amount of nitrogen in the form of sodium nitrate, whilstas regards ash constituents the plants depended on the amountsextracted from the differently manured soils.Carefully selectedseed was employed, and each unit consisted of ten plants, each ina separate solution, which were renewed a t intervals of two weeks.Both plants were grown in extracts of soils from both fields. Theresults of the culture experiments not only showed differences inthe different extrack, but the differences were very similar to thosein the growth of the crops on the plots themselves. To completethe evidence, analyses of the extracts were made, in which boththe total and citric acid soluble phosphoric acid and potassium wereestimated. Whilst extracts of soil from plots which received nophosphoric acid contained from 0.525 to 0.881 per million ofphosphoric acid, the ones derived from the manured plots containedabout 4 per million.The experiments were repeated (with barley soils) so as toinclude, besidw the soil extracts, an artificial culture solution ofthe same strength as the extracts from the completely manuredplots; and soil solutions from partly manured plots with theirdeficiencies in essential constituents made good by adding phos-phoric acid, or potash, or both, The conclusions drawn from theThe potassium results were similar.32 Whitney and Cameron, BdI.22, 1903, Bureau of Sods, U.S. Dept. Agric.33 A. D. Hall, W. E. Brenchley, and L. M. Underwood, Phil. Trans., 1913, B,204, 179 ; A., 1914, i, 126AGRICULTURAL C€IE1\.IISTRY AND VEGETABLE PHYSIOLOGY.225results of the first series were confirmed by the later experiments,and these showed, in addition, that the soil extracts, especiallythose from the dunged plots, were better media, for plant growththan the artificial solutions; and it is suggested that this maybe due to the presence of nitlrogenous compounds which are utilisedby the plants in the early stages of growth.As regards the theory that plants secrete toxins which areunfavourable to the growth of succeeding crops of the same kind,it was found that both wheat and barley gave almost identicalresults whether grown in extracts of wheat or barley soils; bothplants were slightly heavier when grown in solutions from barleysoil than in solutions from wheat soil. Boiling the soil extracts,which should destroy any toxins, had no effect on the results;whilst evaporating the extracts to dryness, igniting, and redissolv-ing the residue generally depressed the yields. The results seemconclusive against the toxin theory, especially when it is remem-bered that wheat had been grown continuously on Broadbalk Fieldfor seventy years.(Toxins appear to occupy, in relation to plantcherristry, a position so'mewhat similar t o colloids in soils, bothbeing found useful in explaining otherwise difficult questions ;except that whilst the colloids are there, the presence of toxinsfrequently has to be assumed.)In order to ascertain the -effects of varying concentrations ofnutritive solutions, which has generally been assumed to be of noimportance, at any rate within very wide limits, experiments werenext made in which barley was grown in solutions containing0.5 gram of potassium diliydrogen phosphate ; magnesium andpotamium sulphates and sodium chloride, 1 gram of potassiumnitrate, and 0.04 gram of ferric chloride per litre, and in the samesolutions diluted to 1/3, 1/10, and 1/20 respectively.From thecommencement the amount of growth varied with the concentra-tion of the nutritive solution, the final dry weight in the strongestsolution being about six times as much as in the most dilutesolution. Similar results were obtained when the plants weregrown in coarse sand through which large amounts of the nutritivesolutions were allowed to percolate, so as to ensure adequateamcjunts of plant food being available.It is evident, therefore,that apart from the total amount of available plant food, theconcentration has a very marked effect on the rate of growth.A further question arises whether plants growing in soil canobtain their food continuously, or whether, after the roots haveexhausted the soil solution in their immediate neighbourhood, theyhave to wait for fresh food materials to diffuse. Barley plants were,accordingly, grown in silver sand containing 20 per cent. of nutri-REP.-VOL. X. 226 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYtive solution, in which condition it contained no free water, andcould be crumbled readily. It was found that, compared withplants grown in solutions of the same strengths, there was notonly no retardation of growth in the sand, due to slow diffusion,but that there was far more growth in sand than in water. Similarresults were obtained when the nutritive solut'ions were supplied inporous cylinders which were placed in the sand in which the plantswere growing, so that in this case the plant food had to passthrough the walls of the cylinders before even reaching the sand.A comparison of the growth obtained in various solid mediawith water cultures showed in each case a higher yield in theformer.Coarse sand gave the best results, then kaolin, silt, and finesand in the order as given. The roots only developed well in coarsesand and kaolin, being very restricted in fine sand and silt, Asthese resulk seemed to point t o deficient aeration, more waterculture experiments were made, in which some were not aeratedwhilst others were aerated daily or continuously. The effect ofcontinuous aeration was t o nearly double the amount of growth,and sufficiently accounts for the greater yields obtained in sandcultures as compared with solutions.Taken altogether, these results show clearly that the compositionof natural soil solutions is by no means constant but varies accord-ing to the manures applied.Also that the, growth of crops depends,not merely on the amounts of plant food, but, within wide limits,on the concentration of the solution. And that the continuousgrowth of the same crop for sixty or seventy years does not leavebehind a specific toxin having an injurious effect on the same orother crops.,4 ssimilatioilt of Nitrogeiz Compoisnds.Whilst the question of the direct assimilation of ammoniumsalts by plants may now be considered to be decided beyond doubt,a good deal remains to be done in connexion with the behaviour ofdifferent plants towards ammonium salts and the effect of thesecompounds as compared with nitrates. Not merely the finalweights of the produce have to be considered, but also the rateof growth, and the effects of the different forms of nitrogen onthe relative amounts of seed, leaf, and roots.It has been foundin sand-culture experiments with mustard and wheat, under condi-tions of sterilisation,34 that the greatest amount of leaf w a obtainedwhen sodium nitrate was employed as source of nitrogen, whilstammonium salts gave the greatest amount of seed.Then, again,34 E. Pantaiielli aud G. Severhi, Bizd. Zmtr., 1913, 42, 98 ; A., i, 435AGRICULTURAL CHEMISTRY AKD VEGE‘I’AELE I’HPSIOLOG Y. 227as regards the behaviour of different plants, it is shown thatmustard developed most quickly under the influence of sodiumnitrate, whilst ammonium salts, especially of organic acids, gavebetter results with wheat than sodium nitrate.I n another series of cultures with peas and maize, also understerilised conditions,35 the plants received ammonium nitrate. Itwas found that the salt was not assimilated as a whole, but that thebase and the acid were taken up in different proportions atdifferent stages of growth. During the early stages of growth morenitrogen was assimilated in the form of ammonia than as nitrate,in the late period more nitrate than ammonia, whilst during theintermediate period ammonia and nitrate were taken up in aboutequal proportions. These results seem to accord with those of anold experiment with rice, in which it was found that the plantspreferred ammonium salts a t the commencement, and nitratesduring later growth.36 Whilst other ammonium salts are physio-logically acid, ammonium nitrate is, according to these results,successively acid, neutral, and alkaline.Some experiments made with etiolated seedlings showed verygreat differences in the behaviour of different groups of plantstowards ammonium salts.37 Certain plants, such as barley andmaize, were found to absorb ammonia readily from dilute solutionsof ammonium chloride and sulphate.Although addition of calciumcarbonate is beneficial, it is not essential, and even without suchaddition, asparagine is readily formed from the ammonia supplied.With peas and vetches it was found that, in absence of calciumcarbonate, salts of ammonium have a retarding effect on thedecomposition of proteins and the production. Addition of calciumcarbonate induced, however, an energetic absorption of ammoniaand production of asparagine. I n the case of lupines, the presenceof ammonium salts seems to give rise t o fundamental disturbancesin t’he synthetic processes, even when calcium carbonate is present.The different behaviour of peas and lupines towards ammoniumsalts is of considerable interest when it is remembered that bothplants will grow luxuriantly when the only combined nitrogen attheir disposal is that provided in their root-nodules by Uacillzismdicicola.The fact that the two plants belong to different groups,each requiring its own modification for inoculation, would hardlyseem to justify the conclusion that each modification makes use ofa different process in assimilating elementary nitrogen. So that,on the supposition that all leguminous plants obtain the same35 J. Scliulov, Be?.. Dew!. hot. Gcs., 1913, 31, 97 ; A., i, 685.36 0. Kellnrr aijd J. Sawatlo, Lnndzci. ~crsz~cl~s-S”tat., 1884, 30, IS.87 D. Prianischnikov, 8e.c. GCn. Bot., 1913, 25, 5.Q 228 ANNUAL 1tEPORTS ON THE PROGRESS OF CHEMISTRY.nitrogenous compound from their nodules, the compound isapparently not ammonia.As regards the assimilation of nitrites, it has been found38 thatwhen potassium nitrihe is dissolved in formaldehyde or in methylalcohol and exposed t o light, the solution contains methylamine,formic and hyponitrous acids, and hydroxylamine, whilst analkaloidal compound containing a pyrrole ring is formed.Asregards the view that nitroxyl, NOH, plays an important part innitrogen assimilation, experiments on the action of mercury lighton nitrites showed that liberation of oxygen is considerablyaccelerated by carbon dioxide, whilst substances of the nature ofa-amino-acids were obtained from potassium nitrite and carbondioxide, with ferric chloride as catalyst.I n connexion with the investigation on the soluble nitrogencompounds present in soils,39 a number of water-culture experimentshave been made in order t o throw light on the behaviour of thevarious substances towards plants.It was found that wheatplants are benefited by argenine, asparagine, choline, creatine,creatinine, betaine, glycine, guanine, histidine, hypoxanthine,leucine, nucleic acid, phytine: and xanthine. Alanine, alloxan, a.ndarbutin were also favmrable to growth when sufficiently diluted,whilst benzidine, guanidine, a-naphthylamine, neurine, picoline,piperidine, pyridine, quinoline, scatole, solanine, and tyrosine wereall found to be toxic.Both histidine and argeriine can take the place of nitrate, andwhen employed in conjunction with a nitrate, considerably lessnitrate is assimilated than when employed alone.40Glucosamine hydrochloride, which might be expected to bevery suitable as a source of nitrogen, is shown to be toxic, a t anyrate t o maize and beans. In the case of beans the substance wasadded t o the solution in amounts from 50 mg.upwards per litre,and in every case caused the plants to wither.41It is evident that the different nitrogen compounds which plantscan utilise are far from being equally suitable; it has been foundthat when two or three compounds, such as histidine, creatinine,and asparagine, are supplied simultaneously, more nitrogen isassimilated than when each one is employed singly.4238 0. B rudisch a i d E PIIayer, Bcr., 1913, 46, 115 ; A., i, 324 ; and Bmlisch,39 0.Schwiner and J. J. Skiiiner, U.S. Dept. Agric. Bureau of Soils, Bull. 87,40 J. J. Skinner, h'iyhth Iiitlr. Cony. AppL C h n . , 1912, XXV, 253.41 M. L. Hamlin, J. Amer. Chcnz. SOC., 1913, 35, 1016; A . , i, 1142.42 0. Schreiner, Eighth Inter. Cony. App. Chcm., 1912, XV, 231 ; A . , i, 1143.Z'itsch. nngetu. C~LCIIL., 1913, 26, 612 ; A . , i . 1424.1912AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 229Plant Stimulants a92d Manzcre.Whilst' a considerable amount of attention continues to be givento the stimulation of plants by small amounts of metallic com-pounds, a good deal of the evidence is conflicting, owing, no doubt,to imperfect methods. The opinion has been expressed that mostpoisonous substances will act as stimulants in certain states ofdilution; as, however, i t would be hardly possible in practice tomaintain the desired degree of dilution, and a comparatively smallchange may convert the stimulant into an active poison, the applica-tion of such compounds, even if their stimulating effect were to besatisfactorily proved, is not likely to be adopted.I n pot experiments with rice43 i t was found that sodium borate,manganese sulphate, ferrous sulphate, and zinc sulphate had favour-able effects in 1 / 1000 mol.solutions, whilst copper sulphate, nickelsulphate, and cobalt nitrate were beneficial only when applied in1/2000, l/SOOO, and 1/10,000 mol. solutions. As the rice wasgrown in soil the concentrations are considered to be higher thanthey would be in water cultures. It is probable that in watercultures the reaults would have been quite different, as i t has beenshown that barley is not stimulated by copper sulphate in culturescontaining 0.1 per million.44Different plants are affected in different degrees by stimulatingsubstances.Vines, for instance, were found to be stimulated by0.001 per cent. solutions of manganese sulphate, and injured byhigher concentrations. Garden beans showed greater stimulationthan vines, and were also found to be better able to resist theaction of stronger solutions.45 I n other experiments on germina-tion46 i t was found that whilst uranium, copper, zinc, aluminium,and cadmium oxides hinder the germination of beans, maize isstimulated.Uranyl nitrate, when applied to Melilotus albus, grown in pots,was found t o be beneficial, especially when applied at the rate of2.5 kilos.per hectare; whilst no toxic effect was observed wheneight times this amount was employed. Lead nitrate gave similarresults with oats and with buckwheat, but as little as 8 kilos. perhectare has a toxic effect.47Boron48 seems to be rather uncertain in its action on beans, andsmall amounts (1 per million as borax, or less when boric acid isM. Rocas, Bied. Zentr., 1913, 42, 41; A., i, 235.44 W. E. Erenchley, Ann. Bot., 1910, 24, 571 ; A., 1910, ii, 889.45 r,. Montemartini, Bied. Zentr., 1913, 42, 65 ; A . , i, 234.4F U. Vnrvaro, Chem. Zentr., 1913, i, 646 ; A , , i, 570.47 J. Stoklnsa,'Compt.<rend., 1913, 156, 153 ; A ., i, 324.48 E. Haselhoff, Lccnclw. Versuchs.-Stnt., 1913, 79-80, 399 ; A . , i, 429230 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.employed) acted favourably on the growth of the plants, whilstthe appearance of the leaves indicated some injurious effect aswell. I n soil cultures 0.1 per million seemed to have a stimulatingaction ; the results vary, however, with different plants.Cerium and lanthanum carbonate~,~g in very small amounts, arefound to be favourable t o the growth of hyacinths, lanthanumcarbonate having a special effect in lengthening the flower stalks.Unsatisfactory results were obtained with yttrium.The results of pot experiments a t lT70burn 5O showed that lithiumsalts, applied a t the rate of 20 per million, or less, t o wheatgrowing in smdy soil, have a stimulating effect which seems to beexerted chiefly during the germinating period.Larger amounts oflitliinm (30 per million or more) are toxic. Comparing the differentsalts of lithium, i t was found that the nitrate is the most activeas a stimulant and also the most toxic.Zinc calts also had a stimulating effect. on wheat, and were toxiconly when the amount applied reached 200 per million. Similarresults were obtained with lead salts, which considerably increasedtha yield of grain and straw. The amounts employed were 100 to300 per million, no toxic effect being observed with the highestamount.I n France a number of field experiments have been made, inwhich zinc and manganese salts were applied t o different crops.With ziac sulphate (from 1 to 10 kilos.per hectare) the yield ofmaize was increased, whilst the results obtained with oats, rye,clover, and peas were irregular.51 More striking results wereobtained with manganese sulphate,52 which increased the yield ofpeas 20 per cent., of colza 18 per cent., and of clover 15 per cent.As regards the amounts of manganous sulphate employed, the bestresults were obtained with from 30 t o 50 kilos. of the anhydroussalt per hectare. The number of successful results obtained withmanganese niake it desirable that manganese should be moresystematically looked for and estimated in soils and in plant ashes,than has been done hitherto.-4lurninium sulphate53 applied to barley, grown in pots, a t therate of 2 per million, increased the yield of dry matter 17 per cent.Larger amounts (4 per million) failed to increase the dry produce,but increased the amount of water retained by the plants.With reference to’ Loew’s hypothesis that lime and magnesia have49 W.H. Evans, Hiochsnt. J., 1913, 7, 349 ; A . , i, 1032.50 J. A To-lck~r, .J. Boy. Agric. SOP., 1912. 73, 314; A., i , 1430.51 M ,JaviIlkr, h’iP(2. Z e ~ h * , , 1913, 42. 21.5 ; A . , i, 692.52 G. Reriraiid, ibicl., 215 ; A . , i, 60253 G . Bcrtrartd and H. Agulhon, ibid. ; A . , i, ti92AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 231to be applied in definite proportions in order t o obtain the bestresults, experiments a t Woburn 54 showed that, wheat is benefitedby adding magnesia t o soil in which i t is deficient, provided thatthe amount does not exceed that of the lime.Whilst an excess ofmagnesia over lime has a toxic effect and diminishes the yield,lime in excess is noh toxic.Magnesia and lime are both capable of modifying the growth ofwheat, and altering the character of the root and the compositionof the grain.Other experiments have been made, in which beans were grownfor three years on small plots,55 the soil of which contained limeand magnesia in different proportions. The results showed that onsoils employed, the relation of lime to magnesia was without effecton beans, and that with increasing amounts of lime in the soil thepercentage of lime in the plants remained the same.From theseresults the conclusion is drawn that whilst the ratio of lime andmagnesia, and of other salts, sometimes affects the growth of plants,the hypothesis cannot be considered its applying to all soils.Results similar t o these hav0 also been obtained with a variety ofplants grown in different soils.56As regards the effect of sugar on crops, the results of pot experi-ments in which sugar was applied to a loamy sand, in conjunctionwith sodium nitrate and ammonium sulphate, showed that theyield of the first crop was depressed, whilst the second crop wasincreased. The final result showed no increase. It would seemthat the low yield of the first crop was due to a portion of thenitrogenous manure being converted into proteins under theinfluence of the carbohydrate, a i d that the proteins were brokendown in time for the second crop.57Results similar t o these were obtained in experiments on ploh,58thd yield being diminished the first year, increased the second year,whilst in the third year the application of sugar had no effect.Ammonium sulphite applied as manure 59 varies in its effecteaccording to the soil, and presumably the rate with which it isconverted into sulphate, since in water cultures it proved to be veryinjurious.I n a loamy soil it had the same effect as ammoniumsulphate, in sand its action was somewhat less favourable, whilstin peaty soil the yield was much less than with sulphate. Calciumsulphite is somewhat toxic in water cultures and perhaps in peaty54 J. A. Voelcker, J. Roy. A g i i c . Sot., 1912, '73, 385; d., i, 1429.55 P. L. Gile arid C. N. Ageton, J. Irzd. B i g . Ciicna., 1913, 5, 561 ; A., i, 1034.56 E. Hasclhoff, Lnnilw. Jcchrb., 1913, 45, 609.57 RI. Gerlacli and A. DciIscli, B i d Zentr., 1913, 42, 21.68 T. I'feiffcr and E. Rlaiick, Lnndw. Yersuclts.-hlnl., 1912, '78, 375.59 W. Tlinlnn, illid., 1913, 82, 161 ; A., i, 1089232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.soil, whilst no injurious effect was noticed in loamy and sandysoils. Sodium thiosulphate also produced no injurious results.I n an experiment with sugar beet60 the application of sulphurwas found to increase the yield slightly, but wae without influenceon the amount of sugar and the quality of the juice.The manurial value of cyanamide has been shown by the resultsof pot experiments with oats to be increased by the addition ofmolasses and by ferric oxide. The effect of molasses is attributedto increased production of carbon dioxide in the soil, whilst ferricoxide accelerates the production of carbamide. The ferric oxidecan be applied in the form of bog ore at the rate of 50 kilos. perhectare.61Met hods.From the earliest days of agricultural chemistry to the presenttime the ina?dequacy of methods of analysis has always been asource of difficulty.Amongst new methods published during the year, referencemay be made to a paper of considerable importance on the estima-tions of carbohydrates, with special reference t o plant extracts.62For the estimation of carbonates in soils, a method has beendevised in which the carbon dioxide is liberated by means of colddilute phosphoric acid, which has very little action on the organicmatter. A current of air, slow at first and rapid afterwards, ispassed through the apparatus for half-an-hour, and the carbondioxide estimated gravimetrically or volumetrically.63N. H. J. MILLER.6" J. Urban, Zeitsch. Zuckzrind. Bohm., 1913, 37, 441 : A . , i, 810.61 A . Stutzor, Eighth I'nter. Cong. Awl. C7~em., 1912, XV, 9 ; A.. i, 114462 W. A. Davis and A. J. Daish, J. Agric. Sci., 1913, 5, 437 ; this vol., p. 186.63 W. H. MacIntyre and L. G. Willis, Agric. Exper. Stat. Univ. Tcnncssee BidJ.,100, 1913

ISSN:0365-6217    

DOI:10.1039/AR9131000211

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

MINERALOGICAL CHEMISTRY.NUMEROUS lines of crystallographic inquiry all converge t o theconclusion that the striking physical differences between the pro-perties of amorphous and of crystalline matter must be referred t othe existence in the latter of a most perfect and unique homogeneityof structure. The abstract geometrical study of homogeneousassemblage8 has accordingly been indispensable to the progress ofthe theory of crystal structure; its commencement may be datedfrom the pioneering work of Hauy, whilst the discovery of the230 generalised point systems by Fedorov and Schijnflies may belooked upon as its fitting culminatioii. However satisfactory thisresult may be, there was Enti1 quite recently no experimentalmethod of elucidating the precise nature of the structural particles ;of discovering whether they are atoms, molecules or molecularcomplexes; and still less of unravelling the exact striiciure of anyparticular substance in all its stereochemical details.The recent discovery of Laue that the passage of a beam ofX-rays through a crystal is signalised by the appearance of severalsecondary beams, opens up an entdrely new field of experimentalresearch, and clearly marks the beginning of an epoch in thehistory of crystallophysical science.The method has not onlyalready led to most important iexults in the hands of its discovererand his collaborators, but has also attracted the attention of otherphysicists who were working on the phenomena produced by thereflection of X-rays from a crystal face.The work which has beendone in these two allied fields has already reached a suitable reportstage. It has, moreover, deep chemical significance, since it promisesto extend th6 domain of stereochemistry into the solid state ofaggregation. I n view of this, the writer feels that no specialapology is needed for a fairly circumstantial account.The development by Fedorov of a scientific method of classifyingmorphological data marks the chief progress to be noted in theprovince of chemical crystallography. Its need must have beenfelt by all those who are interested in the correlation of crystallineform with the chemical composition, for it is becoming increasingly23234 ANNUAL REPORTS ON TIIE PROGRESS OF CHEMISTRY.recognised that an almost unlimited choice of parametral ratiosdeprives any crystallographic description of that finality which isto be expected in a truly exact science.On the practical side thenew classification has made it possible to identify any substancewhich has previously been measured-a distinction which is deniedto all other physical properties ; whilst on the theoretical sidecrystallographic (morphotropic) comparisons between substances arefor the first time placed on a secure basis.Coming t o mineralogy proper, the discovery of several newminerals will have to be noted, as well as the synthesis of severalothers. Space does not permit of a systematic account of thevarious mineral analyses. Fortunately to a great extent they areto be found in the Abstracts for the year.Several very importantpieces of work, as, for example, the experimental study of thepolyinorphous relationships of minerals, have had t o be left overuntil next year.The writer would take this opportunity of apressing his indebted-ness t o the previous reporter, Dr. A. Hutchipson, f o r much valuableadvice as to the sources in which interesting information was likelyto be found.X-Ray Jletltods of Bxploriiig Crystal Structures.The ?Vork of Lam and others on the Diffraction of X-Rays.The experiments of Walter and Pohll on the diffraction effectsproduced by the passage of X-rays through fine slits, led themto the conclusion that the wave-length of X-rays is of the order10-9 cm., a value which is but little less than the estimated distancebetween contiguous molecules in a crystal.I n view of this i toccurred to Laue that, the space lattice structure of a crystal mightact as a grating towards X-rays, and thus lead to difTraction effectssimilar to those obtainable with an artificially ruled grating andordinary light. This expectation was fully realised,2 for it wasfound by a photographic method that if a small pencil of X-raysis allowed to impinge normally on a thin slice of a crystal, thepencil in its passage through the crystal is partly broken up intoa number of secondary beams: the photographic plate which isplaced behind the crystal shows a group of elliptical spots ofvarying intensity in addition to n round central spot due to theundeviated, primary beam.The arrangement of the spots is quitedefinite ; moreover, by shifting the plate backwards or forwardsR. Walter and K. Pohl, Ann. Physik, 1908, [iv], 25, 715.W. Friedrich, P. J<nipping aiid M. Lme, ,4~lruugsber. K. if7:ncZ. lV?ss.JIunchen., 1912, 303 ; Ann. Phgsik, 1913, [iv], 41, 971MINERALOGICAL CHEMISTRY. 235with respect to tke crystal slice, the spot assemblage is propor-tionately enlarged o r diminished, which proTes that each spot isdue t o a rectilinearly propagated beam. On the other hand, anyslight rotation of the crystal slice leads to a corresponding alterationof the pattern. Different substances give different patterns ; thelatter also depend on the direction of the slices from one and thesame crystal.Symmetry of the X-Radiogram.-The influence of the type ofcrystal structure on the diffraction effects produced is very clearlybrought o u t by comparisons of radiograms obtained with differentsubstances. The syrnnietry of the radiogram unmasks the generalsymmetry of the crystal in an unmistakal~le manner.Thus, in thephotographs obtained with sections of the cubic zinc blende, thereis a three-fold arrangement of spots when the slice is cut parallelto an octahedral face, whilst a four-f old arrangement is exhibitedwhen the slice investigated has been taken parallel to a cubeface. Similar patterns are obtained with other cubic substances,as, for example, rock salt, diamond, fluorspar, and cuprite.3 On theother hand, the pattern with a crystal of the triclinic copper vitriolshows no symmetry whatsoever. Intermediate between these twoextremes, we! have the tetragonal nickel sulphate and tin stoneexhibiting a four-fold pattern, and beryl (ernerald), which, inaccordance with its hexagonal symmetry, exhibits a six-f old arrange-ment-provided, of course, the primary beam of X-rays is directedalong the principal axis of the crystal.E'flects produced in, HemiJbedral and Eunntiomorphozts Crystals.-Although zinc blende undoubtedly possesses the symmetry of aregular tetrahedron, the crystals behave as though they possessthe full symmetry (holohedral) of the cube.It might thereforeappear that the X-ray method is not sufficiently searching as toadmit of the complete elucidation of crystal symmetry in all itsdetails.Fortunately this is not always true. For example, thepatterns afforded by slices of iron pyrites, FeS,, and hauerite,MnS,, cut parallel to a cube face, are in full accord with thepresence of a two-fold (and not four-fold) axis of symmetry.Moreover, although the two minerals have the same symmetry, thepatterns are not identical in every respect, thus proving t'hat thespecific natures of the atoms iron and manganese must be takeninto account.Experiments made with quartz crystals lead to results of greaterchemical interest. I f the primary beam is directed along theprincipal axis, the pattern of the radiogram is of a six-fold charac-ter, in so far as the position of the spots is concerned, but if the11. Laur mi F. Tank, A m .Physik, 1913, [iv], 41, 1003236 ANNTJAL REPORTS ON THE PROGRESS OF CHEMISTRY.relative intensity of the spots is taken into account, the arrangementis clearly made up of two sets of spots of different intensity-eachof a threefold nature. I n other words, the rhombohedra1 asopposed to the hexagonal system is fully demonstrated; but thereis no difference between a right- and left-handed crystal. I f ,however, the primary beam of X-rays is sent along the directionof a horizontal two-fold axis of symmetry, the differences betweenthe right- and left-handed structures is betrayed, the pattern of theone being the mirror image of that of the other. A full descriptionof these results has not been published; its appearance is eagerlylooked for.Inteyferertce Theory of Laue.-Laue supposes that the X-rays areof an electromagnetic character (non-corpuscular), and in theirpassage through the crystal set up vibrations, so that each crystalparticle becomes a centre of wave disturbance.The resulting wavesundergo interference, and a spot is produced in the radiogram whena set of vibrations are so close in phase as mutually to reinforceeach other. The general equations governing the interferenceeffect of a three-dimensional grating were developed, and theirapplicability was first tested in the case of a cubic slice of zincblende, and somewhat later a similar mathematical analysis wascarried out for a slice cut parallel to an octahedral face. Settingout from the assumption that the structure of zinc blende ismodelled on the simple cubic lattice-an arrangement in whichmolecules are equally spaced along three sets of mutually per-pendicular lines-the conclusion was drawn that the variousspots are due t o X-rays of five select wavelengths, namely,h = 0*0377a, 0*0563a, 0*0663a, 0*1951a, and 0'143cr, in which a repre-sents the least distance between two molecules, and is equal to3-38 x 10-8 cm.Each spot can then be accounted for as due t o asummation, interference effect of innumerable molecules all disposedin a particular set of parallel planes in the crystal structure.Laue's original deduction that the spectrum of X-rays is dis-continuous, consisting, as it was supposed, of five definite wave-lengths, has not been confirmed by subsequent work.The generalconsensus of opinion now holds to the view that, although thereis always present a certain amount of rays which are characteristicfor each metal used as anti-cathode, yet the main and constantportion of the radiation is continuous within a large range ofwave-lengths. It has been proved by Friedrich4 that the radio-grams are the result of the continuous spectrum, and not of thespecial radiation. The secondary beams, on the other hand, appearto be practically monochromatic, for Wagner 5 has recently foundW. Friedrich, Physiknl. Zeitsch., 1913, 14, 1079. j E. Wagner, ibid., 1232MINERALOGICAL CHEMISTRY. 237that the radiogram produced by the further passage of these beamsthrough a second crystal exhibits a relatively small number ofspots.Now a difficulty arises in the application of Laue's theoryto a continuous spectrum: the diffracted rays should not lead tothe development of well-defined spots, but rather should cause ageneral darkening of the whole of the photographic plate. Thisdifficulty has been removed by Debye,G who has pointed out thatthe crystal particles are not in reality stationary a t the ordinarytemperature, but must possess some vibratory or oscillatory move-ment by virtue of their heat energy. His mathematical analysisindicates that the intensity of the diffracted wavelets from mostplanes of the structure must be reduced to exceedingly low valuesowing to the molecular vibrations, and only in those planes in thestructure which are characterised by a fairly dense packing ofparticles will the effect survive this weakening of intensity.Suchplanes are those which are characterised by low indices in acorrect crystallographic description, and every spot in the radio-gram corresponds with the diffractive action of a particular struc-tural plane.Other Attempts at l?xplci~ia~io~a.-Other attempts have not beenwanting t o account for the formation of the spots. The first ofthese explanations7 is based on the corpuscular theory of X-rays.It is supposed that the corpuscles travel most easily in certainavenues of the crystal, each set cjf parallel avenues giving rise to aspot. It has been pointed out, however, in a paper8 in which theprinciples involved in the analysis of a radiogram are very clearlydescribed, that there are many fairly wide avenues in the crystalwhich are quite unrepresented by a corresponding spot in theradiogram.The second view advanced9 is that the spots are dueto reflections at the surface of cleavage cracks, which may be sofine as to escape detection by ordinary optical methods. Quiteapart from the obvious drawback that one must presuppose theexistence of cleavages. which have never been observed in practice,there are other weighty considerations which militate against thisview.10A novel way of interpreting %he action of the crystal on theX-rays as a pure reflection effect a t internal planes of particleswas early suggested by W. L. Bragg.11 Although recent mathe-matical developments12 prove that the Laue and Bragg viewsamount t o much the same thing, yet the reflection view has providedP. Debye, Ber.Deist. physikal. Ges., 1913, 15, 857.G Wulff, ibid., 1913, 14, 217.lo M. Laue, ibid., 1075.W. L. Riazg, Proc. Ccmb. Phil. SOC., 1913, 17, 43.7 J. Stark, Yhysikn2. Zeitsch., 1912, 13, 973.9 3. Blan~lelstarn and H. Eohman, ibid., 220.la P. P. E~ialcl, Physikal. Zcilsch., 1913, 14, 465238 ANNUAL REPORTS ON THE PROGRESS OF CHEMIS'I'RY.an extraordinary stimulus to investigation, since it has served t ocorrelate the phenomena observed by the undoubted reflection ofX-rays with the diffractive effects already described.Iwterpretation of 'CV. L. Bragg.-Each spot in the radiogram isdescribed as due to a reflection of part of the energy of the incidentbeam of rays, by a set of parallel planes of atoms in the crystal.The planes that are most likely to act as reflectors are those whichare densely packed with atoms, and the likelihood of obtaining anintense reflected beam is all the greater when the same conditionsare fulfilled, as in the reflection of ordinary light from piles ofparallel plates, namely, when 9th = 2d sin 6, where 6 is the glancingangle (that is, 90O-normal angle) of incidence, a! is the distancebetween successive parallel planes, A is the wave-length of theradiation, and n=1,'2, 3, 4, etc.When this equation is satisfied,the trains of waves reflected from each of the reflecting parallelplanes are in the same phase and will reinforce each other, sothat a reflected beam may be produced of sufficient intensity as t omake a visible impression on the phctographic plate.The positionof a spot on the plate is in all cases determined by the directionof the internal plane serving as a reflector, the angle of incidence011 that plane being equal to the angle of reflection. I n the lightof this interpretation, the Laue radiogram for zinc blende wasreconstructed by Bragg, but it was concluded that the space latticeis not of the simple'st cubic pattern. This conclusion has been con-firmed by others, and has also been developed stereochemically bythe author in a very interesting manner.I n studying the intensity of the spots, ingenious use has been madeof the two-circle goniometer,13 a cleavage piece of rock salt beingmounted in such a position that the incident beam of rays impingeson internal cube and dodecahedral planes a t the same angle.Thespot derived from the cube plane is much more intense than thatresulting from the dodecahedral plane. These two secondary rayswere then allowed t o impinge on a second crystal suitably mounted,and it was found that only one visible tertiary spot is produced,namely, that originating from a reflection of the secondary cubeplane of the first crystal a t the internal dodecahedral plane of thesecond crystal. This result could be predicted from Bragg'sequation, and thus confirms its validity in an unmistakable manner.A novel adaptation of the Laue experimental arrangement 14 is toreplace the photographic plate by a barium platinocyanide screen,whereby the direction of the secondary beams are immediatelyshown by their fluorescent action on the screen.The elliptical':; G. WuIff and N. Uspciiski, Phyrikal. Zeitsch., 1913, 14, 755.l 4 T. Terad:i, I'roc. l'okyo JIath. phys. Xoc., 1013, 7, 60A1 I N E li A LOG1 C A L C H E M 1 YTR Y . 239arrangement of groups of spots corresponding with sets of internalreflecting planes having a common zone axis is especially striking,and the effect produced on the symmetry and general arrangementof the spots by a rotation of the crysta.1 plate can be very con-veniently studied.T h e Work of 717. H . and Tf7. L. BrccggI4a and others on t h eReflection of X-Rays b y Crystals.The capital discovery that X-rays are strongly reflected a t thesurface of a crystal was made by W.1;. Bragg.15 A narrow pencilof rays was allowed to impinge on a cleavage surface of mica a ta glancing angle of lo", or, in other words, a normal angle of80°, arld after a n exposure of only a few minutes, a photographicplate revealed a strongly marked spot due t o reflection as well asthe usual primary spot due t'o a direct passage through the crystal.The relative disposition of the primary slid secondwy spots showedthat the angle of reflection is equal t o the angle of incidence. Amore sensitive method of estimating the intensity of the reflectedray was quickly devised by W. H. Bragg,16 who replaced the photo-graphic plate by an ionisation chamber, by means of which thestrength of the reflected beam can be accurately gauged.Thearrangement finally adopted is much the same as that of a spectro-meter, the ionisation chamber replacing the ordinary telescope, sothat the variatioc of the effect with the angle of incidence can beeffectively studied. Confirmatory notices soon followed from otherworkers.17The main results attained with the above apparatus18 may beepitomised as follows: The law of equality of angle of incidenceand reflection having been established, a series of experiments wasinstituted in which the ionisation chamber and incident beam wereconcomitantly varied with respect to the crystal plate, and theremarkable discovery was made that the intensity of the reflectedbeam varies enormously with the angle of incidence.Curves inwhich the intensity is plotted against the glancing angle ofincidence, for crystals of iron pyrites, rock salt, zinc blende,potassium ferrocyanide, potassium dichromate, quartz, calcite, andsodium ammonium tartrate, all exhibit three peaks, A,, B,, C,, veryclose to each other, which with larger angles may be succeeded by aI q n Prof. TV. 11. Uragg, of Lectls University, and liis son bIr. W. L. Bmgg of tliel 5 W. L. Hragg, 12-u!zc~e, 1912, 90, 410.Caveiidisli I,alm,ztory, Canil.)ri(lgc.J ( l W. H. Hragg, ?bid., 572.C. G. 13ai.kla a i d G. 11. Af:trfyii, ibid., 435, 647 ; 13. G. J. Moseley andW. H. and W. I,. Bragg, P,roc. Iloy. Soc., 1313, A, 88, 428.C. G. Darwin, ibitl., 591240 ANNUAL REPOIC'I'S ON THE PROGRESS O F CHEMISTRY.second, although less pronounced, system of peaks, A,, B,, C2,and these by a third system, A,, B,, C,.The conclusion is drawnthat in addition to the general reflection of less intensity occurringa t all angles of incidence, there is a selective reflection occurringa t certain and very definite angles. This must be attributed tothe existence in the primary X-rays of three monochromatic beamshaving specific wave-lengths. Each of these beams would beexpected t o suffer intense reflection when the equation nh=2dsin 8is satisfied. As a matter of fact, the three peaks B,, B, B, satisfythe equation most rigorously when n=l, 2, and 3 respectively.I n the above experiments the anti-cathode was made of platinum.Other metals have since then been tried.19 Since the incidentangle of maximum intensity varies for each metal, it must beconcluded that the wave-length of the special radiation is charac-teristic for each metal.Nickel, tungsten and iridium are found t ogive weaker characteristic beams. The most satisfactory materialfor anti-cathode proves t o be rhodiumF0 which gives an intenseradiation of two wavelengths, one being far stronger than theother.The effect of a change of the factor d (the distance betweensuccessive parallel, structural planes which cause the reflection) onthe value of the intense, reflecting angle has been studied byexamining plates cut parallel to the cube, dodecahedron and octa-hedron faces of rock salt. The values of the angles a t which theB peak is observed have been measured, and by means of thereflection formula quoted above, the values d l : d,: d3 can becalculated; they are found t o be 1 : 0.718 : 1-16. Now it is a simplematter to calculate these ratios by pure geometry on the assumptionof any given space lattice.Such theoretical values for the centredface lattice of the cubic system are 1 : 0.707 : 1.15. The reflectionevidence then appears to be overwhelmingly in favour of this latticein rock salt.The above work also proves that the reflecting plane is not merelythe geometrical surface of the crystal, but rather a succession(perhaps millions) of internal structural planes which lie underand parallel to the cleavage surface. This deduction is confirmedby some experimentsz1 which have been instituted with quartz andgypsum, in which the surface was roughened t o such an extent asto scatter ordinary light completely.On the contrary, the intensityof the reflected beam of X-rays is not weakened appreciably.A further valuable contribution to our knowledge of selectivel 9 W. H. Bragg, Proc. Boy. h'oc., 1913, 89, 246.2a W. H. and W. L. Bragg, ibid., 277.21 E. Huplia, Ber Deut. phgsikal. GES., 1913, 15, 369MINERALOGICAL CHEMISTRY. 241reflection has been made by Moseley and Darwin22 with anapparatus allowing of even more delicate measurements than thatof Bragg. The latter’s results have not only been confirmed, butby the use of finer slits it has been possible to resolve Bragg’ssecond and third peaks, so that there are no less than five homo-geneous series of X-rays (platinum anticathode j, each yielding areflection of the first, second, and third orders.It was early observed that the spots in the Laue radiograms arestriated, and on closer study23 it has been found that striationsare also exhibited by the spots given by the reflection method. Theactive cause of the striation appears t o be a lack of homogeneityof the crystal, parts of the latter not being quite parallel to otherparts.With regard to the penetrative powers of the X-rays, it hasbeen proved by Moseley and Darwin,*Z as also by Barkla andMartyn,24 that there is little difference between the incident andreflected radiation.It must be noted, however, that a considerableamount of comparative work on the diffraction and reflectionmethods leads to the suspicion that the effects of the crystal are notentirely identical ; although the diffracted rays retain theirfluorescent action on barium platinocyanide, rays reflected from acleavage flake of rock salt are inactive in this respect.Moreover,the wave-lengths as deduced by Laue are much lower than thoseobtained by the employment of the reflection method. It has there-fore been suggested that the ciystal may transform the incidentX-ray energy into another order of wave-length.Stereochemical Dediictioirs front the X-Bay Methods ofIwestigation.The probable arrangement of the molecules and atoms has beendeduced by W. L. Bragg25 for the binary compounds, zinc blende,rock salt, potrqssium chloride and bromide, and as far as thecalcium atoms are concerned, in fluorspar and calcite also.Boththe diffraction and reflection methods of investigation wereemployed. An analysis of the radiograms f o r all the substancesenumerated with the exception of potassium chloride points to thecentred face form of lattice. Now a considerable amount ofevidence is also deduced in favour of regarding the heavy atomsas the diffracting centres; these atoms must then be arranged onOB H. G. J. Moseley and C. G. Darwin, Phil. Mag., 1913, [vi], 26, 210.21 G. Wulff a i d N. Uspenski, Physikal. Zeitsch., 1913, 14, 783 ; M. de Broglie,Compt. rend., 1913, 156, 1153 ; M de Broglie and F. A. Lindemaun, ibid., 1461.24 C. G. Rarkla and G. H. Martyii, Proc.Loizdoit PItys. Soc., 1913, 25, 206.25 W. L. Rragg, Proc. Boy. Soc., 1913, A , 89, 248.REP.-VOL. X. 242 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the centred cube pattern. I n the binary compounds the lighteratoms can be arranged in the same pattern, and so disposed withthe heavier atoms, that the assemblage as a whole becomes of thesimplest cube pattern (see figure for sodium chloride, in which theblack-point circles represent alkali metals, light-point circles thehalogen atoms). It is then suggested that in potassium chloride,since the constituent atoms have weights of the same order ofmagnitude (39 and 35.5) both kinds of atoms act as diffractingcentres, so that the radiograms should point t o the simplest cubicarrangement. Strong confirmation is obtained from reflectionexperiments. I n the case of fluorspar and calcite, the calciumatoms would appear t o have the centred face arrangement; theposition of the lighter atoms has not yet been determined.(Note:Calcite, being rhombohedral, can be regarded theoretically as adeformed cubic crystal.)The structure of the diamond 20 has also been very thoroughlyinvestigated, the results presenting many features of exceptionalinterest. The structure suggested is modelled on the centred facepattern, but with the following complications : half the total numberof cells, selected in a symmetrical manner, have in addition afurther point placed a t their centres. The effect of this is thatthe successive planes of particles parallel t o the octahedral facesare no longer equally distant from each other; in other words, thestructure is no longer a space lattice, but an example of theFedorov-Schonflies point systems.Since the diamond is of'elementary composition, there can be 110 question as t o the morepowerful diffractive power of certain atoms as compared with others(as in the case of the halogen salts, zinc blende, etc.), and theevidence given in support of the structure advocated is very con-vincing. The chief chemical interest of the arrangement lies in thefact that each carbon atom throughout the whole structure iMINERA1,OQICAL CHEMISTRY. 243immediately surrounded by four others in a regular tetrahedralmanner.The elucidation of the space lattice structure of a cubic crystal isa comparatively easy matter as compared with the difficulties t obe expected in a crystal, say, of the monoclinic system, since notonly has the type of lattice t o be discovered, but also its relativedimensions, f o r the latter are not fixed by the symmetry.Apraiseworthy attempt to determine the space lsttice of gypsum,CaS0,,2H20, has been made by Herweg,zs who allowed a beam ofX-rays to impinge on a cleavage plate a t a glancing angle of loo,and took photographs of the secondary beams due t o reflection andrefraction. From an analysis of the results i t is inferred that thestructure is founded on the monoclinic pinacoidal lattice, tlie threeplanes of the cell being parallel to {OIO}, { l O O } , and { 101) of theusual setting.It is hardly necessary to point out that, a t any rate, some of theviews which have been described cannot be regarded as final, butmay possibly undergo considerable modification when furtherevidence has been accumulated. However this may be, there wouldseem to be little doubt t h a t in the near future the employment andfurther development of X-ray methods will lead t o a full knowledgeof the disposition of tlie constituent parts of a crystal in most ofits essentials.C 11 e t n i c CI 1 C' r y s t ( I 11 o I/ r CI 1) h y .Crystallography can perhaps only boast of two occasions onwhich it has profoundly coiitributed to chemical theory, namely,when Mitsclierlich discovered isomorphism, and Pasteur proved thecorrelation of optical activity in the amorphous condition andenantiomorpliism of crystalline form.Later investigations, in sofar as they relate t o syst'ematic researches, have served t o multiplyillustrations of these regularities. The great majority of publisheddata, however, relates t o isolated compounds, which have beenmore or less fortuitously placed a t the disposal of the crystallo-grapher by the synthetic chemist. The classification of thismaterial according t o chemical composition is obviously not likelyt o lead to any chemical progress. A classification according tothe geometrical constants of the crystal itmy, on the other hand,result in the discovery of close crystallographic resemblances, andhence of similarity of chemical constitution, between substances,wliicli might not otherwise be sought for, owing t o the retardinginfluence of a periodical stereotyping of the general outlook-afeature, inseparable from the history of science, which is just as26 J.Herweg, Plrpikcil. Zceztsch., 1913, 14, 417.R 244 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.helpful in the early stages of discovery as i t is detrimental to anyimportant subsequent advance.Difficulties in t h e TVay of a Moryhologicctl Clussificatiou ofCrystallographic B a ta.It is self-evident that no classification can be regarded assatisfactory unless i t is grounded on well-founded principles of anunambiguous character. The difficulties to be overcome incrystallography are of a special kind. The complex facial develop-ments of most crystalline substances leads to an embarrassingnumber of angular values, from which a small selection has to bemade for purpose of reference.I n describing a crystal i t is theusual practice to select certain of the angular values in order t ocalculate the parametral ratios a : b : c ; which selection has hithertobeen quite arbitrary, for other alternative angles might equallywell be chosen yielding a different set of parametral ratios. Nowthe parametral ratios of two substances may on comparison exhibita close numerical similarity; on the other Eand, if such is not thecase, i t is as a rule quite an easy matter to produce from them,by a process of trial, other sets of ratios exhibiting a cloae corre-spondence. These facts show that any close correspondence ofparametral ratios does not necessarily imply any real structuralsimilarity in the two substances compared.The same remarkapplies equally well t o the “topic axes” of Becke and the“equivalence parameters” of Barlow and Pope, which are in sub-stance parametral ratios multiplied by a constant factor, havingits origin in the molecular volume and valency volume respectively.Now wherever the primary object of a crystallographic investigationis to complete and add dignity t o a chemical description of thesubstance, it matters little in what form the parametral ratios aregiven. If, however, the investigation is to do more than provideadditional physical data and to attempt to elucidate the stereo-chemical interrelationships of two substances, i t is of paramountimportance that the ‘‘ real ” parametral ratios are employed-by“real” is meant those ratios which measure the relative edgelengths of the ultimate structural unit.It is true that in veryclose cases of chemical similarity, as, for example, those groupedunder the term “isomorphism,” the validity of a comparison canbe established by means of certain crystpallophysical methods, butin the most general case it is impossible t o estimate the objectivevalue of any alleged similarity.One of the main channels of Fedorov’s thirty years of activityhas been directed towards the development of the principles of ascientific morphological classification. The crowning success of thiMINERALOGICAL CHEMISTRY.245work, namely, the foundation of ‘‘ crystallochemical analysis,” hasbeen appreciated in its general outlines in last year’s report.Following is a short account of the prirzciples adopted by Fedorov inhis classification.The Principles of Fedorov’s Classification.It is universally recognised that every crystalline substance isbuilt up on a definite space lattice framework, although individualcrystals may vary considerably as to the number and relative sizeof the faces. One of the fundamental properties of a space latticestructure is this : the relative massing of particles “ reticular-density ” varies enormously in cfifferent planes of the lattice. Thisproperty is made use of by Fedorov, who follows Bravais in theassumption that the faces actually developed correspond in themain with lattice planes having a high reticular density.Thisassumption is so sound theoretically that i t is probably subscribedto in principle by all crystallographers. Its validity has beenemphasised by the recent work of Friedel27 on the form develop-ment of certain minerals, as also by the classical experimentalwork of Wulff28 on the velocity of growth of a crystal in differentdirections. It is also in harmony with the accepted interpretationof the X-ray work on crystals. Now reticular density is not theonly factor which influences the development of crystal faces; itis, however, the most important factor, and, what is very important,it is susceptible to exact mathematical formulation. Thus, if anyparticular space lattice be provisionally accepted for a given crystal,i t is possible to verify by simple calculation how far the facesactually developed do correspond with planes of high reticulardensity ; and since the values of reticular density are characteristicfor each lattice, a choice can be quickly effected of the particularlattice which gives the highest all-round values for the facesdeveloped.I n actual practice probably two or three space latticessuggest themselves to the expert, and their relative merits arequickly estimated either by a simple graphical method,2Q or evenby a consultation of tabular values which have been recentlyc0rnpiled.3~ The ratios of the three principal linear dimensions ofthis space lattice are nothing more or less than the true parametralratios of the substance. They are deduced quite independently foreach substance the composition of which may remain unknown ;G.Frirdcl, Bzcll. Soc. f m q . Min., 1907, 30, 326.25 G. Wnlff, Zcitseh. Kryyst. illin., 1901, 34, 449.29 E. S. Fedorov, ibid., 1909, 46, 245.Yd W. J. Sokolovand I). N. Artemiev, ibid., 1911, 48, 377246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.consequently there is no subjective attempt t o induce a numericalsimilarity to confirm any previously conceived theory.The trustworthiness of the above procedure is proved by the factthat the same set of parametral ratios is independently obtainedfor two crystals of one and the same substance, no matter whetherthe facial development is identical o r not.I t s fullest vindication,however, is afforded by cases of isomorphism; here the similarityof crystal structure demands <a corresponding similarity of para-metral ratios, and this always accrues in actual practice; in otherwords, the employment of Fedorov’s principles unerringly discoverssimilarity where such indeed exists. It must be remembered thatnothing need be known concerning the composition of the sub-stance whilst the crystal analysis is being effected.The second and concluding problem relating t o the correctsetting or description of each crystalline substance is that dealingwith the appropriate orientation (“ Aufstellung ”) 31 of the latticewith a view to uniformity of description ; this question is evidentlyassociated with the allocation of suitable indices to the faces, thechoice of specific edges to serve as vertical, left to right, and front,t o back directions.Such questions are mainly of a purelymethodological character; they are none the less of the greatestimportance for the final classification.It is in this connexion that Fedorov finds indispensable his theoryof parallelohedra, enunciated in 1885.32 The theory is really anextension of the space lattice, in that it attempts to endow thepoints of the space lattice with a corporeal shape expressing eitherthe matter of the molecule or_ its domain of influence, so that thecrystal structure ceases t o be merely a collection of points, butbecomes a system of figures, all alike and arranged in a parallelmanner, filling space without interstices.Although the assignmentof a particular shape to the crystal particle introduces debateablequestions, and might, superficially be deemed an unnecessary com-plication, yet the conception of the’ parallelohedron is of great helpin co-ordinating into one organic whole crystals belonging to dif-ferent systems of symmetry, and i t is therefore a most valuableconstructive implement. By means of i t Fedorov is enabled t ogroup together the whole of the crystal material into three grandtypes, an immense advance for the purpose in hand on the usuallyaccepted seven systems. The nature of this grouping can beindicated witlic u t further reference to the paralleloliedron.I n describing a tetragonal, rhombohedra1 (trigonal) or hexagonal51 E.S. Fedorov, Zeitsch. Kryst. illin., 1904, 38, 321.s2 E. S. Fedorov, “ Elenleiits of the Theory of Fignies” (Rum.), 1885 ; ibid.,1911, 48, 400MlNERALOGlCAL CHEMISTRY. 247crystal, i t is customary to set up the crystal with the superior axisof symmetry in the vertical position, and also to apply a distinctsystem of indices to each of the three cases. On the other hand,the rhombic, monoclinic, and ixiclinic systems do not possess asuperior axis of symmetry, and on this account, apart from theuse of the tetragonal system of indices, there has hitherto beenbut little method in the descriptive setting of the crystals. Theguiding principle now adopted by Fedorov is t o set up the crystalin such a way as t o bring out its approximation to oiie of the threehigher systems, and then make a consistent use of the appropriatesystem of indices.To take the case of a monoclinic crystal, forexample, when its space lattice has been determined by an analysisaccording to reticular density, the crystal is examined with respectt o the angular values of the principal zones, and is then set upwith that zone vertical which approximates most closely either t o90° or t o 60°. The vertical axis then approximates to a four-foldor six-fold axis of symmetry; in tho latter case the form develop-ment is scrutinised in order t o discover whether i t is best regardedas a three-fold or six-fold axis. It will now have been decidedto which one of the three main groups of crystals the substancebelongs-the tetragonaloid, trigonaloid, or hexagonaloid.Thevertical direction having been settled, the left to right and frontto back directions follow from definite rules; finally appropriateindices are allotted, and the description becomes complete anduniform.The correct setting has been determined for all the substanceshitherto measured (somewhat over lO,OOO), and the index entitled(‘ Das Kristallreicli,” which is in active preparation, will be pub-lished in about eighteen months by the St. Petersburg Academy ofScience. Crystallochemical analysis will then be within the reachof every crystallographer. I n the index the matter is classifiedaccording to the tetragonaloid, trigonaloid, and hexagonaloidgroups.The imrnediate basis of arrangement in each of thesegroups is the magnitude of the angle between the basal plane andthe primary pyramid, which varies in crystals between the limits10--80°; the division into subsections is made every half degree.The value of the angle mentioned determines any tetragonal,rhombohedral, or hexagonal crystal absolutely ; with crystalsbelonging to a system with lower symmetry, the angular deviationsfrom these ideal types are added. An ingenious system of symbolshas been devised, each crystal being represented by a symbol whichsums up its geometrical constants, and distinguishes it from anyother crystal.It’ is not suggested that Fedorov’s method is absolutely infallible248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Isolated cases (actually less than 1 per cent.) present themselves,in which the correct setting cannot be determined with finality.One result of the classification should be to stimulate anew thecorrelation of crystalline form and chemical composition, since thematerial to be compared has now been classified on a sound basis.Another interesting result of the work33 has been t o prove thechemical identity of several '' pairs of substances " which have beenhitherto supposed by chemists to be different compounds.Enan tiomorphism.Enantiomorphism of molecular configuration has been discussedin its general aspect by Barker and Marsh,34 who have pointed outthat the adoption of any single criterion fails t o meet all caseswhich might arise.Thus absence of a plane of symmetry or of acentre of symmetry does not of necessity imply enantiomorphism.The complete ccnditions for enantiomorphism, and hence ofappearance in optically active f orrns, are the simultaneous absenceof a plane of symmetry, a centre of symmetry and an alternatingaxis of symmetry.The reasons for this are best appreciated byconstructing models of objects which are in themselves completelyasymmetric, as, for example, gloves; i t is found that for any modelpossessing any one of the three specified elements of symmetry, anequal number of right and lefcl handed gloves are required, everysuch assemblage being internally compensated.It is also emphasised that an enantiomorphous assemblage neednot be entirely asymmetric, for enantiomorphism is not incom-patible with the presence of an ordinary, as opposed to alternating,axes of symmetry.An interesting case illustrating this point is thatof the cis- and tmm-forms of 1 : 4-diketo-2 : 5-dimethylpyrazine, thecis-form of which, although possessing a two-fold axis of symmetry,Me Me Me €1I NH*COC<co.r;H>C . CO'NH I,$<NH*CI) >ct I .H H H Meis optic.ally active. The tmns-form (alanyl anhydride), on theother hand, has a centre of symmetry, and as a result is internallycompensated. Exactly similar possibilities are to be mei; in lactideand succinosuccinic ester. Again, many of the co-ordinated com-pounds which have been recently so successfully resolved byWerner possess ordinary 'axes of symmetry ; for example, the com-plex chromium oxalate group, Cr(C,O,),, in the optically active33 E.S. Fedorov, Zeitseh. Kryst. J f i ! ~ . , 1912, 50, 573.34 T. V. Barker and J. E. Marsh, T., 1913, 103, 837MINEKALOGICAL CHEMISTRY. 249potassium chromium oxalate, has a three-fold (trigonal) as wellas three two-fold (digonal) ,axes of symmetry.The same paper contains a discussion of the structural relation-ships which must accompany the appearance of optical activity inthe crystalline condition, and it is concluded that the optical activityof crystals of sodium chlorate and bromate, Schlippe’s salt,Na3SbS4,9H,0, sodium uranyl acetate, NaUO,(C,H,O,),, sodiumdihydrogen phosphate, NaH,PO,,H,O, as well as in magnesiumsulphate, MgS04,7H,0, must be referred to enantiomorphism of themolecule.Suitable spacial formuk are suggested which aremodelled on an extension of Werner’s theory of co-ordination.Copaux’s conclusion that d- and I-crystals of sodium chlorate havedifferent solubilities has been called into question by Kreutz,35 whoargues that Copaux’s results require a new interpretation. Copauxmeasured the relative increase in area of d- and I-crystals whilegrowing under the same conditions, but this is not the same asmeasuring the thickness deposited on the faces since the crystalsemployed were not cubes but rectangular parallelepipeda. Thenew interpretation of the experimental results leads t o the con-clusion that an equal increase of thickness obtains with the twoantipodes. Moreover, Kreutz found that saturated solutions incontact with either antipode have the same concentration.An explanation has still to be found for the well-established andinteresting observations of Wyroubov and of Copaux on the silico-tungstates; with many of these substances I-crystals are very rarelymet with.A valuable contribution to the crystallography of opticallyactive substances has been made by Hutchinson,36 who has describedthe rhombic d-tetrahydroquinaldino-d-methylenecamphor and itsantipode, as well as tho m onoclinic, partly racemic d-tetrahydro-quinaldino-dl-methylenecamphor and its enantiomorph.Owing tothe absence o f hemihedral facets, the former pair of antipodes aregeometrically indistinguishable, but in the latter pair, enantio-morphism is elegantly indicated by the polar character of thecrystals.A close morphotropic relationship is found to existbetween the four compounds.Isomorphism.A further contribution to the well-known series of the hexa-hydrated double sulphates and selenates has been published byTutton,37 who has investigated the geometrical and optical charac-ters of Mohr’s salt, (NR4),Fe(SO4),,6H2O. The results obtained36 St. Kreutz, Zeitsch. Kryst. Min., 1913, 51, 236.36 A. Hutchinson.37 A. E. H. Tutton, Proc. Roy. SOC., 1913, A, 88, 361; A., ii, 603.See W. J. Pope and J. Read, T., 1913,103, 1515250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.completely confirm the conclusions previously derived from a studyof the ammonium salts of the same series, and again prove that,although not belonging to the eutropic series potassium, rubidium,and caesium, the structural function of the ammonium radicle isvery similar t o that ol the three alkali metals, so that the iso-morphism is of a very close character.Generally speaking, theammonium salt shows greatest approximation in its physicalcharacters t o the corresponding rubidium salt. This constant iso-morphous replaceability of a single metallic atom by a radicleconsisting of no less than five atoms is probably the most remark-able regularity known t o the crystallographer.An investigation wliich has considerable theoretical interest asbearing on the miscibility of isomorphous substances is that ofSchobert,3s who has studied the equilibria a t high temperatures ofbinary mixtures of sodium chloride, bromide, and iodide, as wellas the ternary systems obtained therefrom by the addition of wateras the third component.Fusions of sodium chloride and bromideafford an uninterrupted series of mixtures with a eutectic lying a t731°---Roozeboom’s type 111. The miscibility again is perfect fromsolution above 60°, but a t temperatures below 50*7O, which marksthe appearance of the dihydrate of sodium bromide, the miscibilityis of necessity restricted, since we have to deal wit-h an isodimorphouspair. The transition temperature of NaCl into NaC1,2H20 is a t0 * 1 5 O , below which there is a possibility of perfect miscibility, sincethe dihydrates are isomorphous. Experiments proved, however,that there is a gap in the series.Remembering that the percentagedifference of halogen is much less in the hydrates than in theanhydrous form, it is seen what a large influence must be attributedto temperature in the degree of isomorphous miscibility.Another investigation of a similar character, which was alsocarried out in the Leipzig Mineralogical Laboratory,39 relates tomixtures of sodium and potassium chromate both ir, presence andabsence of water. These substances behave in a manner preciselyanalogous t o t h a t of the correxponding sulphates, and form a doublesalt, 3K2Cr04,Na,Cr04, chromeglaserite, which is able t o take upisodimorphously a certain amount of sodium chromate. At veryhigh temperatures the sodium a17d potassium salts form an uninter-rupted series of mixed crystals, which on cooling break up intochromeglaserite and excess one cf the simple chromates.A valuable contribution t o the crystallography of the rare earthshas been made by Rodd,40 who has described a number of iso-38 E.Schobert, Diss., Lcipzig, 1912.39 E. Flack, ibid.40 E. H. Rodd, Proc. Roy. SOC., 1913, A, 89, 292 ; A., i, 1167MINERALOGICAL CHEMISTRY. 251niorphous hydrated 2 : 5-dichloro- and dibromo-benzenesulphonatesof lanthanum, neodymium, praseodymium, gadolinium, anddidymium ; also the trihydrate of 2 : 5-dichlorobenzenesulphonicacid as well as its potassium, sodium, zinc, and magnesium salts.Of these compounds the two last-mentioned are closely isomorphous,and the data given fully prove the isomorphous replaceability ofchlorine and bromine'.The author attempts t o bring the material into consonance withthe Barlow-Pope theory, aiid has recourse t o methods of interpretingthe goniometrical results, which are open to criticism.For example,having initially discarded the most simple indices in order t o get afairly close value for the monoclinic angle P , the author subse-quently employs the fractions 2ri / 3 , c / 4 for the sodium salt, and3cr/Z,c/2 for tlie potassium salt of the dichloro-acid, and the desiredmorphotropic resemblances are established between the two saltsand tlie parent substance benzene. The author is here followingthe example of Barlow and Pope' ir, regarding this device aslegitimate, but it has been iost sight of that the geometricaldevelopment of the two substances, as expressed by indices, nowacquires the extravagant form: {loo}, {320}, {342}, and (302)for the potassium compound, and { O O l } , {803}, {403}, {230},{ 4.12 .3} and { 441) f o r the sodium salt; and the absence of anyface common t o the two crystals appears t o make hazardous anycomparison whatsoever.Morphotropic Resemblances.The term morphotropy was introduced by Groth in 1870 t oconnotate tlie study of the specific effect on crystalline form broughtabout by the substitution of hydrogen in benzene by the halogensor by groups like OH, NO,, CH,, etc.Although such substitutionslead to a somewhat fundamental alteration in the crystallographicconstants, yet in a great many cases the effect appears to be con-centrated on one of the parametral ratios, the other remainingrelatively unchanged. Since then the meaning of the term hasbeen somewhat widened, so that it has now practically come tomean the general study of the correlation of crystalline form andchemical composition.I n this widened sense enantiomorphism andisomorphism axe but particular cases of morphotropy, in which theresemblance is highly pronounced.For the first time' in its history the general subject of morpho-tropy has been placed on a scientific basis as a result of Fedorov'swork on the correct description of cryst'als. During the year tw252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,important papers 41 have been contributed, in which various topicsof interest are discussed.It is pointed out that i t is impossible toset a limit to isomorphism, the variations of angle for chemically,very closely related subst?ances ranging from very small to verylarge values. Many cases are given in which two substancescrystallise in different systems and yet exhibit a very close simi-larity; this is an argument against regarding a difference of systemas a barrier against isomorphism. Another conclusion is that adifference in the water content of hydrated compounds is com-patible with a close similarity of crystalline form. It appears t othe writer, however, that many water determinations are faulty,and that more accurato determinations might bring the formulaeof many compounds into harmony.As a direct result of his classification Fedorov is enabled t o cite alarge number of cases of similarity between substances which havenot hitherto been regarded as similarly constituted, although ageneral, if only empirical, analogy is easily apparent, and the term“ isotectonic ’’ is suggested to meet such cases.The followingselection of isotectonic compounds will perhaps bring home thenature of the chemical resemblance :K,ZnCI,,K2S0,,UsHgBr,, (Me,N)2CYuCI,. Hg(OH)ClO,,K F BF,.&.I g,SiO4,A1,G1O4. KCrO,F, KRuO,.It seems likely that compounds like the above will repay furtherstudy, and perhaps be of use in recasting current views on valency.CsNO,,(hSiO,. MgFpRuO,,Hg( q,.Chromoiso m erides.The term “ chromoisomerism ” has been proposed and employedfor some years by Hantzsch in connexion with substances crys-tallising in several modifications, which are mainly distinguishablefrom each other by colour.The subject has been already criticisedin these where it was pointed out that the experimentalevidence for isomerism, as oppose,d to polymorphism, is very slight.The isomerides do not appear to possess any separate stable existencein solution, and the variously coloured forms with any given solventyield chemically and physically identical solutions. Slight dif-ferences in the absorption spectra in the ultra-violet region are,however, observable. The explanation given by Hantzsch for thevarious isomerides is founded on Werner’s theory of valencyisomerism.‘l E. S. Fedorov, Zeitsch.Kryst. Mim, 1913, 52, 11, 97.42 Ann. Report, 1911, 54MINERALOGICAL CHEMISTRY. 253One of the most striking cases of chromoisomerism, namely, thatUPhof plienylacridonium hydrogen sulphate :which is generally quoted as exhibiting a yellow, red, and greenmodification, has been recently- subjected to a very thoroughcrystallographic investigation by Pauli,43 the results of whichconfirm the view adopted on the previous report. The crystallisationwas studied from various mixtures of the three solvents, water,sulphuric acid, ana alcohol, and no less than six varieties areobtained differing either in colour or in crystalline shape, namely,stout, red, monoclinic crystals, brown plates, yellowish-brownneedles, green, triclinic crystals, green plates, and green needles.The variety which separates from solution is determined by theproportions of the thre? solvents; a large alcoholic content, forexample, favours the formation of red crystals.Goniometricalmeasurement and determination of the crystallo-optical propertiesas well as the specific gravity proved the identity of the first threevarieties on the one hand, and the three latter varieties on the otherhand. The crystallographic constants for the red (brown andyellow) are a : b : c =2*398 : 1 : 2.141 ; p =98O5/; whilst for the threegreen varieties the constants are a : b : c =0*907 : 1 : 0.739;a = 118010r, p= 114O32’, y = 59O42’. The colour of each form appearst o depend somewhat on the degree of fineness of the material, afact which is well known in mineralogy.Again, the same crystalsmay appear diff erenbly tinted when viewed in different directions ;this is due to the strong pleocliroism of the crystals.The red and green crystals, on keeping, become covered with ayellow coating; this was held by Hantzsch t o be an isomeric changeinto the yellow modification. The yel!ow coating is now found tobe crystallographically identical with phenylacridine, so that thechange really denotes a hydrolysis of the acid sulphate.The red crystals are stable on heating up to the melting point,265O, but with the green crystals a remarkable colour changebegins a t 162O and is complete a t 175O, when the colour has becomereddish-yellow. On further heating, the tint becomes more andmore red.The results obtained by sl3wly cooling the fused substances areindependent of the original modification employed.Two forms43 0. Pauli, Diss., Lripzig, 1912254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.appear, the first being brownish-yellow and optically identical withthe monoclinic red modification. The second form is greenish-yellow and optically identical with the green, triclinic modification.The above investigation has been described in some detail becausei t illustrates very well how far a crystallographic investigation maybear on a point; of chemical theory; the acid sulphate of phenyl-acridine must be regarded as dirnorphous and not trichromoisomeric.Mitzernlo9.y.T l i w r t d Stuclks of Miizerctls.The application of the phase rule to the investigation of thebehaviour of mineral mixtures continues to attract much practicalattention, especially on the part of American workers, and thepresent year is distinguished by at least one really first-class pieceof work.The methods of investigation have been so much improvedthat the accuracy of a high temperature determination may nowbe confidently trusted. The great disagreement between theselatest thermal data and those resulting from former researchesprove that the latter cannot pretend t o Guch accuracy, but mustbe looked upon as pioneering work of an orientative character.The importance of the subject, especially to the geologist, canscarcely be overrated, inasmuch as i t touches on some of themost fundamental problems connected with the natural historyof rocks.Many petrological regularities have already met with asatisfactory explanation on a physico-chemical basis, apropos ofwhich it will be sufficient to quote from Bowen’s paper: “ I n viewof the very great quantitative importance of the plagioclases inigneous rocks i t is a matter of some satisfaction to find themobeying the laws of physical chemistry t o the extent here found.”Plaglioclase FeZspnrs.-The important work of Bowen 44 on themelting phenomena of these minerals deals with the determinationof the solidus and liquidus curves for mixtures of albite,NaAlSj,O,, and anorthite, CaAl,Si,O,. I n order t o determinethe temperature a t which a given mixture begins to melt, it wassteadily kept at a certain temperature for half-an-hour, and thensuddenly cooled by quenching in mercury.Any melting is easilydetected optically by the presence of glam in the specimen, due t othe rapid quenching. By successively trying higher and highertemperatures until the presence of glass is rioted, the point on thesolidus curve is thereby obtained. Again, by raising the tempera-ture still higher, until no tr‘ace of crystalline material remains afterquenching, the whole having been melted and then solidified intoglass, the corresponding point in the liquidus curve may be realised.4J N. L, Bowen, Ainer. J. Sci., 1913, [iv], 35, 577 ; A., ii, 613MINE K A LOG I C A L CHEM I STItY. 255The temperatures were determined by a thenno-couple, and theresults are accurate to about 5O. The melting points of albite andanorthite were found to be l l O O + l O o and 1550+2O respectively(for other data see the abstract).Independent confirmation of thecomFosition of the liquid phase was obtained by a determinationof the refractive index of the glass by Becke's immersion method.The values so obtained were compared with those of Lar~en,~5 andthe a,greement is extraordinarily good. The author further testedhis results in the light of the equations deduced thermodynamicallyby van Laar, which admit of a calculation of the solidus andliquidus points from the latent heats and absolute melting pointsof the pure components. The agreement is again very striking.Of the author's two principal conclusions, the first is that albiteand aiiorthite must have the same molecular complexity in thOliquid, as also in the solid state, but the complexity in the twostates may be quite different.The second conclusion relates tothe frequently observed zonal development of the natural plagio-clases-the nucleus of the crystals is practically always relativelyrich in anorthite, the outer layers becoming richer and richer inalbite. Now the paths of the two curves are such that the differencein composition of a crystal and the liquid in equilibrium with i tmay differ by as much as 40 per cent. ; a magma consisting initiallyof 50 per cent. of each constituent will deposit crystals containing81 per cent. of anorthite; and, since diffusion in the solid crystal isvery slow, its composition will not respond t o alterations of com-position set up in the magma, the net result being that the' crystalwill become covered with successive layers of material relativelypoor in anorthite.The melting-point curve of the naturally occurring mixtures oforthoclase and albite has been determined by means of the Doelterheating microscope.*^ Most of the minerals contain small amountsof lime in the form of anorthite, which is found t o have consider-able effect in lowering the melting point.The melting interval wasabout 25O, and the lowest temperature registered was met with inthe case of cryptoperthite from Laurvik with a 58 per cent. albitecontent, thus confirming Vogt's opinion that this represents theeutectic of the series.The author believes, however, that the seriescorresponds with type Z I T of Roozebooni's classification, and not V,as suggested by Vogt.Miscellu 11 co u s E l i i s i o ris.--Tlie thermal investigation of mineralmixtures is undoubtedly beset with great difficulties, some of whichhave been recently subjected to detailed investigation.47 Mineral4i E. S. Larseti, A m r . J. S&.) 1909, 28, 283 ; A . , 1909, ii, 841.46 E. Dittler, Tsch. Mi)). Jlitt., 1912, 31, 513.47 H. Leitmeier, Zcitsch. anorg. Chem., 1913, 81, 209 ; A., ii, 613256 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.products are seldom pure, but contain in solid solution othermaterials of either much higher or lower melting point; it is thusto be expected that different values are frequently obtained bydifferent observers. Again, the melting operation is generally agradual process ; sintering (passage into a solid, amorphous form)generally takes place, and a clear liquid is not obtained until amuch higher temperature is reached.The sintering point mayvary by as much as BOO, depending on the relative coarseness ofthe grain. The author prefers to take the lower sintering point asthe melting point rather than the upper point of mobile liquefac-tion, basing his choice on the greater precision which can beattached to a change, crystal + amorphous, than to a change,glassy-amorphous + liquid-amorphous. The selection of the lowertemperature receives further justification as a result of some newdeterminations, in which the mineral wits heated to a point atwhich i t just begins to sinter, and then kept a t that temperaturefor twelve, twenty-four, or even forty-eight hours.It was thuspossible to transform a crystal of St. Gothard adularia (orthoclase)into a viscous liquid at 1145O-the temperature a t which it firstshowed signs of sintering.The thermal and optical behaviour of the sulphates of calcium,strontium, barium, and lead-that is, the minerals anhydrite,celestine, barytes, and anglesite-as also of the binary mixturesof each of these sulphates, as well as glucinum sulphate, withpotassium snlphats, has been studied in great detail by Grahmann.48It is found that all the four mineral sulphates are reversiblydimorphous with transition temperatures a t 1 1 9 3 O , 1 15Z0, 1 1 4 9 O ,and 8 5 2 O respectively.The high temperature modifications aremonoclinic, and probably all isomorphous. With the exception ofK,SO, + PbSO,, the binary systems are signalised by the appearanceof a double sulphate 1 : 2, analogous to the mineral langbeinite,K,S0,,2MgS04, in composition, but not in crystalline form. Thecalcium, strontium, and lead langbeinitw, however, are isomor-phous ; moreover, each yields another modification a t high tempera-tures, the points of transition lying a t 936O, 750°, and 544O respec-tively.A large number of thermal investigations of binary mixtureshas been carried out, chiefly in Bruni’s laboratory, by Italianworkers. Although highly interesting, they cannot be entered intohere, since they have little, if any, direct mineralogical bearing.The investigation of Zambonini 49 on the miscibility of thetungstates of cerium and lead is of some mineralogical importance,48 W.Grahmano, Diss., Leipzig, 1912.49 F. Zarnbonini, Atti R. Accnd. Lincei, 1913, [v], 22, i, 519; A., ii, 596MINERALOGICAL CHEMISTRY. 257since it is often assumed that these metals can replace each otherisomorphously in certain minerals. The two substances were,indeed, found to yield an uninterrupted series of mixed crystals-Roozeboom’s type I.Hydrothermal Formation of Minerals.h review of the present position in this branch of work byMorey and Niggli5O has appeared during the year. The papercontains a critical bibriography of all the syntheses hithertoeffected, and must be invaluable to those who take an active interestin the subject.It must be remembered that the reactions oftentake plaoe at temperatures far above the critical point of water,whilst the solid phases may have melting points at still highertemperatures. The important qumtion as to the equilibrium r6leplayed by water receives an adequate discussion. The work ofSmits 51 on the system anthraquinone-ether a t temperatures belowand above the critical temperature of ether has a very cogentbearing on this point, from which work it is inferred that too muchimportance has all along been attached to the significance of thecritical point of water on questions of silicate equilibria. Owingto the very small solubility of silicates, the passage of the waterinto the critical condition can perhaps have but little effect onthe relative stability of the minerals.It is possible that the mainpart of the chemical change takes place in the solid phase, andthis, in turn, must especially favour the formation of productswhich are not absolutely stable, but merely metastable. The fre-quent formation of tridymite when quartz is to be expected is thusexplained. Again, the stubborn persistence of metastable phasesexplains the differences noted in the products by taking the initialmaterials in a different chemical form, although in the sameult8imate quantitative proportions. The authors’ final conclusion isthat the problems of hydrothermal silicate syntheses can physico-chemically be worked out on the same lines as van’t HOE’Sresearches on the Stassfurt depoaits.With regard to the temperatures which are most favourable forthe separation of various minerals, it appears that the zeolites areeasily prepared a t temperatures up to 200O.The region betweGnthe limits 300-550° is characterised by the frequent formationof quartz, the felspars albite and anorthite, and analcite; but thesimultaneous formation of those minerals which frequently accom-pany the above in nature, namely, the pyroxenes, amphiboles,50 G. W. Morey and P. Niggli, J. Amer. Chenz. Sci., 1913, 35, 1086; A., ii, 861.51 A. Smits, Zeitsch. ph ysikal. Chetn., various papers.REP.-VOL. Y. 258 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.micas, magnetite, haematite, corundum, etc., has been only veryseldom noticed.The study of the system K,0+A1203+Si0,+H,0 by E.Baurhas been noticed in a previous report.52 The effect of the additionof ferric oxide has now been studied by Niggli,53 and with theinteresting result that the best crystallised product is potassiumzgirine, KFe(SiO,),. The heating was carried out in a steel bombfor one t o two days to a temperature of 450O. The identifiableminerals accompanying K-aegirine were hzematite, orthoclase, andhydrated K-nepheline. A relatively low percentage of alumina isindispensable for the appearance of I(-zgirine, which, by the way,does not occur in nature, although its sodium analogue,NaFe(SiO,),, is an important member of the pyroxene group.Itsnon-observance in nature is, perhsps, due to the fact that magmascontaining a large amount of potash as opposed to soda arealso always rich in magnesia and lime; the latter unite with thewhole of the iron to form augite, leaving none for the potash,which then combines with the alumina to form leucite, KAl(SiO,),.Pofnssizim nepheline, KAlSiO,, apparently identical with thelittleknown mineral kaliophilite, has been synthesised by Friedel 54by heating in a steel, copper-lined tube to a temperature of 600°a mixture of muscovite and a solution of potassium hydroxide. Thecrystals obtained are hexagonal, and very similar in their generalproperties t o ordinary soda nepheline, NaAlSiO,. The aut.hor haspreviously shown that if the reacting substances contain even avery small amount of soda, the only product is a practically puresoda nepheline.This is in harmony with the common occurrenceof the latter in nature and the rare occurrence of kaliophilite. Theauthor is of the opinion that the excess of silica found in allnephelines has not yet received a satisfactory interpretation.Anhydroth ermd S p t h e s e s of Miuerals.The most interesting synthesis of this class is certainly that ofanorthite, CaAl,Si,08, effected by Reynolds55 from a very novelsource. ThI: mainspring of this work is the author’s previousextensive researches on silicon organic conipounds, in which it hasbeen shown that the group SiN (analogous t o CN) is an integralpart of niany synthetic substances.Attempts were first made to prepare the compound Si,Al, analo-gous to cyanogen by the combination of the free elements, but52 A m .12epot-t, 1911, 247.53 P. Niggli, Zktitsch. nnorg. Chem., 1913, 84, 31.54 G. Friedel, Bull. SOL f r n q . Jli?~,-1912, 35, 471 ; A . , ii, 422.55 J. E. Reyuolds, Proc. Roy. SOC., 1913, A, 88, 37 ; A . , ii, 212M INEKALOGICAL CHEMISTRY. 259with iinperf ectly satisfactory results. I n presence of calcium,however, a well-defined substance is formed, Ca(SiAl),, termedcalcium siiicalcyanide, which from its general chemical behaviourmust be regarded as entirely analogous to calcium cyanide,Ca(CN),, in constitution. When subjected to the action of acurrent of oxygen and steam a t a high temperature, the compoundtook up eight atoms of oxygen to form CaAl,Si,O,, which whenfused and slowly allowed t o cool gave a pure specimen of anorthite,identity being established by chemical and optical methods.Thederivation and constitution of anorthite as given by the authorare expressed in the following scheme:Calcium silicalcynnide. Anortliite.Attempts were also made to isolate sodium silicalcyanide with aview to the ultimate synthesis of albite, but were fruitless, owingto soine extent to the volatility of sodium a t the high temperaturerequired.New Minerals.CIi ilZugitc."--'l'he mineral was found in Christmas Gift NorthMine, Chillagoe, in the form of tabular, translucent, yellow plates,together with cerussite. The crystalline form has not been thor-oughly determined, but appears t o be tetragonal.Analysis corre-sponds with the formula PbWO,,PbMoO,. Until further crystallo-graphic hetails are given, i t must remain uncertain whether themineral is a new species, or merely an isomorphous mixture ofstolzite and wulfenite.Czcsterite.57-The occurrence is in a limestone-granite porphyrycontact zone near Mackay, Custer Co., Idaho, the associeatedmineral being magnetite, wit,h a certain amount of garnet anddiopside. The mineral occurs in fine, granular masses, and appearsto weather into calcium carbonate; there are three distinctcleavages parallel to the forms { l l O } and {OOl}, and their relativeinclinations argue for the monoclinic system. This conclusion wasconfirmed by an optical determination carried out on the Fedorovuniversal stage.Obt. Bx. the symmet,ry axis; positive Ac. Bx.nearly normal to (001},2V,, = 60°, 2E= 1 0 5 O , @= 1.59, y-a=0-0121,H = 5, G = 2-91. Repeated twinning parallel to { 001 } .Analysis points to the formula [Ca(OH,F) ],SiO,, the ratio OH : Fbeing about 4 : 3. The mineral is therefore related to zeophyllite,cuspidine, and hillebrandite.A. T. Ullmann, J. Roy. Soc., New South Wales, 1912, 46, 186 ; A., ii, 867.57 J. B. Umpleby, W. 'l'. Schaller and E. S. Larsan, Anzcr. J. Sci., 1913, Liv],36, 385 ; A., ii, 1063.s 260 AYNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.DeZafossite.58-This mineral was first described from Siberia byFriedel in 1873, but has been hitherto looked upon as a doubtfulspecies.It has now been found at Bisbee, Arizona, in platycrystals, constituting a combination of (111) large and {loo} ofthe rhombohedra1 system: a : c= 1 : 1.94. It is found in a whitekaolin and ferruginous clay a t the fourteenth level of the Hoatsonshaft of the Calumet and Arizona property, near Copper QueenMine. The compcsition is that of a cuprous metaferrite, Cu’Fe”’O2.Epide~mine.5~-This new zeolite occurs with orthoclase as acrystalline crust on calcite a t the Gelbe Birke Mine, Schwarzen-berg, in the Saxon Erzgebirge. Analysis points t o exactly the sameformula as stilbite, and the two minerals in all probability presenta case of dimorphism. The symmetry is rhombic with a develop-ment of the three pinacoids. On some specimens a single inclinedface, say, ( l l l ) , vas observed, from which the values a : b : c =0.7315 : 1 : 0.4181 are deduced provisionally.Gyothine.“-This new mineral, which has been named in honourof Prof. P. Groth, occurs in a metamorphic limestone a t Noceraand Sarno in Campagnia, Italy. The colourless crystals belong t othe rhombic system with a : b : c=0*4575 : 1 : 0.8484. The habit ista-bular, parallel to b{010}. Porms: b{010}, c - {OOl}, m- {110},e - {101), 0- (1111, and r-{121). D=3*085. Optics, positiveAc. Bx. perp. to (loo), ax. pl. (001); 2E medium, p<v. Theamount of material as yet available does not admit of a quantita-tive analysis. Qualitative tests points to an alumosilicate of calciumwith a trace of iron.Hodgkinsonite.61-This mineral is a hydrated zinc-manganesesilicate, and occurs in the Parker Mine a t Franklin Furnace, NewJersey. It is always associated with barytes in the granularwillemite-franklinite ore of that locality. The crystals are mono-clinic with a : b : c = 1.539 : 1 : 1.1165 ; /3 = 84O33‘. The forms are :m - { l l O } , s - {Oll}, and r - { 221}, together with corrosion planeshaving complicated indices. D = 3.91, H = 5 ; mean refractiveindex=1*73, ax. pl. (010). The, colour ranges from a bright pinkto a pale reddish-brown; the lustre is vitreous, the streak white.Analyses agree with the formula SRO~SiO,,H,O, where R=Zn andMn in the ratio 2 : l ; also present small amounts of lime andmagnesia.Maucherite.62-The locality is Eisleben, Thu-ringia, the mineral55 A. 3’. ItOgCrj, Amcr. J. Sci., 1913, [iv], 35, 290 ; A . , ii, 419.59 V. Rosick3; a n 1 S. Tliugutt, Centr. mi^^., 1913, 422 ; A . , ii, 783.Go F. Zannboiiiiii, Atli h!. Accnd. Lincci, 1913, [v], 22, i, 801.G1 C. Palache aiid W. T. Schaller, J. Washington Acnd. Sci., 1913, 3, 474.62 F. Griiuliag, Ci:iit~.. Miit., 1913, 225 ; A . , ii, 516 ; A. Rosati, Atti 12. Accnd.Lincei, 1913, [v], 22, ii, 243MINERALOGICAL CHEMISTWY. 261being found in the copper shales. The symmetry is tetragonal;a:c=1:1’1185; forms: c-(OOl}, t - (223}, p - (445)’ 0- (111)’d- (554)’ v- (443}, e - (553)’ I- {221}, g - {552}, h - {331), and71 - (441). Analysis agrees with the formula Ni3A%. A producthaving this composition is often met with in metallurgical pro-ces~es, and has been variously termed ‘‘ Nickelspeis ” and “ Placo-din,” and it is interesting t o note that Rosati has been able toshow that the lately discovered mineral and the long knownartificial product are crystallographically identical.FJylroxmangife.~3--The locality is near Iva7 Anderson Co., SouthCarolina, where the mineral occurs in brown cleavage masses witha cleavage angle equal t o 8 8 O 1 0 ’ . The system is probably triclinic.Although analysis agrees with the formula (Mn,Fe)SiO,, the opticalproperties differ from those of rhodonite, and the authors accord-ingly believe the mineral t o be a new species of the manganesepyroxenes.T. V. BARKER.G < W. E. For3 and JV. M. Bradley, Awe?. J. Scf., 1913, 36, 169 ; A . , ii, 849

ISSN:0365-6217    

DOI:10.1039/AR9131000233

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

RADIOACTIVITY.IN the last section of the 1910 Report, “Chemical Relationshipsof the Radio-elements,” the existence of groups of radio-elementspossessing identical chemical properties was shown to foreshadow“ some embracing generalisation which will throw light, not onlyon radioactive processeg, but on the elements in general and thePeriodic Law.” I n 1911 the first step in this direction was made,when it was recognised that the expulsion of the a-particle causesthe radio-element t o change its position in the periodic table, notinto the next family, but into the next but one in the directionof diminishing group number and diminishing atomic mass.2 Lastyear doubtful points ifi the sequence of changes, consequent uponthe branching of the disintegration series a t the C-members, and onthe existence, in uranium, of two chemically identical elements,uranium-T and -TI, were cleared up, and the important step madethat the B- and C-members of the three series exhibit identicalelectrochemical behaviour.3 I n the meantime, a systematic studyof the chemical nature of those disintegration products not hithertothoroughly studied from a chemical point of view had resulted ina remarkable.extension of the feature which dominates thechemistry of the radio-elements.* Radioactinium was shown to bechemically identical with thorium ; mesothorium-11 with actinium ;the three R-members and radium-D with lead; the three C-membersand radium-E with bismuth ; thorium-11 and actinium-D withthallium5; and radium-A with polonium.Thus, not a single oneof the radio-elements, known a t the commencement of the year,Ann. Report, 1910, 285.F. Soddy, “ Cheiniitry of the Radio-elements,” 1911, p. 30.Ann. Rcport, 1912, 311, 321, 319. Compare also E. Marsden ant1 R. H. Wilson,Phil. Mag., 1913, [vi], 26, 354 ; A., ii, 907 ; P. Beer and K . Fajms, Physikal.Zcitseh., 1913, 14, 947 ; A., ii, 907 ; A. P,. Wood, Phil. Nag., 1913, [vi], 26, 586 ;A., ii, 908 ; K. Fajans, Physikal. Zeitsch., 1913, 14, 951 ; A . , ii, 903 ; G. vonHevesy and L von Pntnoky, Phyciknl. Zeitseh., 1913, 14, 63 ; Phil. Mag., 1913,[vi], 25, 415 ; A . , ii, 175.A. Fleck, Chem. News, 1912, 106, 128; 1913, 107, 95; T., 1913, 103, 381,1052.Compare also W. Metzener, Ber., 1913, 46, 979 ; A . , ii, 375.2GKAD i OACTLVITY.263has a peculiar chemical nature unsliared by otheri. All arechemically indistinguishable from one or other of the elementsoccupying the last twelve places of the periodic table, from thalliumt o uranium. With the sequence of changes fully elucidated andthe chemical character of the majority of the radio-elementsestablished, the a-ray rule was shown to hold generally, and, equallygenerally, a similar rule for the p-ray changes was found to apply.I n the B-ray change, the element shifts its position in the periodictable in the opposite direction to that in the a-ray change, butinto the next family, not into the next but one.6 These two simplerules, consistently applied to the three disintegration series, con-stitute a sweeping generalisation connecting the chemical characterof the radio-element, and tlie position it occupies in the periodictable with the kind of radioactive change in which it is produced.I n addition to the purely chemical discoveries considered, an electro-chemical examination of the radio-elements led independently tothe same generalisation.It was found that the expulsion of thea-particle resulted in a produst more electro-positive, and of a&particle more electro-negative, than the parent.The generalisation is illustrated in tlie chart (Fig. 1). Thissatisfactorily accounts for all the peculiar features that characterisethe chemistry of the radio-elements. Whenever, by the expulsionof a- or &rays, two o r more elements come to occupy the sameplace in the periodic table, then, independently of all other con-siderations, such as the atomic weight, the disintegration seriesto which the element belongs, its radioactive character and thenature of the radioactive changes, in which it is produced, or bywhich i t is transformed, these elements, occupying the same place,are non-separable from one another, and are, so far as is known,identical in chemical character.Each vertical row of the diagramconsists of such a group of chemically identical elements. The tenoccupied places contain over forty distinct elements, whereas ifchemical analysis alone had been available f o r their separaterecognition, only ten elements could have been distinguished. Theplaces a t the end of the periodic table, and probably elsewhere inthe table, thus represent, not single homogeneous elements as hashitherto been supposed, but groups of elements identical in chemicalcharacter. To express this newly discovered complexity of matter,the terms isotopic elements ” or ‘ I isotopes ” have been coined.Thus radiothorium, ionium, thorium, uranium-XI, and radioactiniumA.S. Russell, C?~ern. News, 1913, 107, 49 ; A., ii, 274 ; K. Fajans, Physikal.Zeitseh., 1913, 14, 131, 136; Bcr., 1913, 46, 4 3 2 ; A., ii, 276, 277 ; Ber. Deut.phyiknl. Ges., 1913, 15, 2 4 0 ; A . , ii, 493 ; LE Rndium, 1913, 10, 171 ; A . ,ii, 660 ; I!’. Soddy, Char&. Arcws, 1913, 107, 97 ; Jnhrb. Radioaktiv. Elektronik,1913, 10, 188 ; A., ii, 275264 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.are a group of isotopic elements, the calculated atomic masses ofwhich vary from 228 t o 234.They all occupy the same place inFIG. 1.Reproduced by the courtesv of the British Association from a block illustratiitg“ l’he Radio-elements and the Periodic Law,” hy F. Soddy, Section E, Birmingham,1913.the periodic table, and are chemically indistinguishable. Thismaterial identity, however, extends far beyond the chemical proRADIOACTIVITY. 265perties in the narrow sense, and embraces probably nearly all thecommon physical properties also, so that the experimental meanscapable of distinguishing and separating isotopes are very limited.’Thus, eleven years ago, the result that the radium and thoriumemanation condense at practically the same temperature seemedvery extraordinary.Now there is every reason t o believe thatisotopes will prove to be indistinguishable in volatility no less thanin chemical properties. The question whether isotopes have thesame spectrum, for example, was discussed f o r the case of ioniumand thorium last year.* Important new evidence can be urgedboth for and against the general view. The recent generalisationthat the magnitude of the atomic weight enters exactly into theseries relationships of spectra, and the expectation that has beenadvanced that, ultimately, it should be possible to determine atomicweights from these series relationships more accurately than bychemical analysis,g is obviously opposed t o the possibility thatelements of different atomic masses can have the same spectra.Neon and illetaneon.-On the other hand, what appears to bea case of isotopic elements outside the radioactive sequences hasbeen discovered. As has been remarked, very few material pro-perties depend directly on atomic mass.Fractional diffusion ofgases is almost the only property that can be expected t o effect apartial separation of a group of isotopic elements into their con-stituents. Whilst, t o detect the non-homogeneity if it exists, thenew positive ray method of Sir J. J. Thornson10 is again almostthe only one available. The examination of atmospheric neon bythis method revealed the presence of atoms, in relatively smallproportion, of mass 22, in addition t o the known atom of mass 20.The relative proportion of the two kinds of atoms was unchangedafter a prolonged fractionation of the gas by cold charcoal; butfractional diffusion showed that atmospheric neon is not homo-geneous, and a partial separation, attested by a change of density,was effected by this means.No change in the spectrum correspond-ing with the change of density was observed, however, and the twoelements appeared t o be identical in all properties, except atomicweight.11This accords with what, has been found in the case of ionium“ Chemistry of the Radio-elements.Ann. Ileport, 1912, 321.IV. M. Hicks, Phil. Trans., 1913, A , 213, 323 ; A . , ii, 810.Pdrt 11. The Radio-elements and tliePeriodic TJitw.” I3y F. Soddy : L~ngtnans, Grern & C o t 1914.lo Sir J.J. Thomson, B1keri:rn Lecture, Proc. lioy. Soc., 1913, 89, A, 1 ;l1 P. W. Asliton : Paper communicated t o the British Association, Section A.,A , , ii, 820.Xi r mingh a m, 1 9 1 3266 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and thorium, as regards th2 spectra, and in the case of the radiumand thorium emanation, as regards the volatility, and indicatesthat isotopes will prove to be identical in these respects as theyare in chemical character. A t the same time, the discovery is amost dramatic extension of what has been found for the elementsa t one extreme of the periodic table, to the case of an element a tthe other extreme, and strengthens the view that the complexityof matter in general is greater than the periodic law alone reveals.Although the complexity is greater, the problem of atomic structurehas been much simplified, because the generalisation gives aprobable explanation of the absence of exact simple numericalrelations among the atomic weights.Uranium-X2 or Breuzum.-NThen the rules were first appliedthere was one obvious lacuna between uranium-X and uranium-TI,for, by the rules, two successive 8-ray changes are necessary to shiftan element in group IV into group VI.This suggested thaturanium-X was probably complex, and that its two types of &rays,one very hard and the other very soft, result in two successivechanges, with the intervention of an intermediate element occupy-ing the place in group V, hitherto vacant. The new element wouldbe the homologue of tantalum.The resolution of uranium-X intotwo distinct radio-elements, named uranium-X, and uranium-X2,followed almost immediately.12 By application of the electro-chemical rules, it was to be expected that uranium-X, would bemore easy t o separate electro-chemically than uranium-X,, and i twas found that polished lead plates, immersed for a minute in afeebly acid solution of uranium-X, gave the hard P-rays ofuranium-X, which decayed wibh a half-period of 1-15 minutes. Thiscorresponds with a period of average life for uranium-X, of 100seconds, whereas the period of uranium-X1, the parent, is 35.5 days.The chemical analogy of the new member to tantalum is clearlyshown by other methods of separation. I f uranium-X, separatedfrom uranium, together with thorium, in acid solution, is added t oan alkaline solution of potassium hexatantalate, uranium-Xz isalmost quantitatively precipitated with the tantalic acid, whilsturanium-X, remains in solution with the thorium.Similarly, theseparation may be effected by filtering the uranium-X solutionthrough a layer of moist tantalic acid. By this and many otherreactions it was proved that uranium-Xl, of average period 35.5days, emits only the soft P-rays and produces uranium-X,, ofaverage period about 1.6 minutes, which emits the hard &rays.K. Fajans and 0. Gohring, i~~alrLrw.issenschaftcn, 1913, I, 339 ; Physikal.Zeitsch., 1913, 14, 877; A., ii, 909 ; 0. Halin and 1,. Meitner, ibid., 758 ; A., ii,821 ; A.Fleck, Phil. Mag., 1913, [vi], 26, 528R A DI 0 ti CTI V ITY. 267Although uranium-x, is chemically analogous to tantalum, itshould prove t o be separable from it, just as radium is frombarium, or polonium is from tellurium. As it is a new chemicaltype, its discoverers have given it the distinctive name Brevium.”At present it is unique among the radio-elements, in occupying aplace in the periodic table by itself. T S s distinction is, however,likely to be only temporary, as already it is necessary to postulateas isotope to account for the origin of actinium.Origin of A ctiniurn.-The unsolved .problem of the origin ofactinium has been considerably narrowed down by the periodic lawgeneralisation. Being in group 111, its parent must be in group V,isotopic with brevium, if it is formed in an a-ray change, or ingroup 11, isotopic with radium, if it is formed in a &ray change.As radium is the only member of the uranium series in group 11,the latter alternative is equivalent to supposing that radium itselfis the parent-that, in addition t o the a-ray change into theemanation, radium suffers a branch &ray change into actinium.Although this is supported by the fact that radium, and alsothorium-X, in the same place, give, in addition t o a-rays, some softP-rays, which constitute something of an exception to the simplerules, the production of actinium h o r n radium has been disproved.l3No detectable amount of actinium was found in a preparation ofradium bromide which had been kept for ten years without inter-ference, and contained 13.2 mg.of radium (element). Wereactinium the direct product of radium, this negative result wouldmean that the period of actinium must be a t least fifteen millionyears, whereas it is practicaliy certain that its period cannot beas great as one hundred years.The alternative is to suppose that actinium results from anelement in group V by an a-ray change, and, since brevium is short-lived and gives no a-rays, this requires that an unknown isotopemust exist in the uranium series. The suggestion has been madethat the series may branch a t uranium-X1, P-rays being expelledin both branches, so that two isotopic products result.14 Thebranchings so far studied have been of the character that in onemode a &ray change is followed by an a-ray change, and, in theother mode, an a-ray change is followed by a &ray change.Thesuggestion that in both branches the same type of ray is expelledis novel, and although not necessarily improbable, would, if adopted,largely increase the number of possibilities to be taken into account.One, in particular, seems wortli discussion.Uranium-Y.-In 191 1 Antonoff found that the soft &radiationl3 F. Soddy, Natuw, 1913, 91, 634.l4 0. Hnhn and L. Meitner, Ph,pika2. Zeitsch., 1913, 14, 752; A., ii, 821268 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of uranium-X decays, in certain cases, abnormally rapidly for thefirst few days after the separation of the substance from uranium,and concluded that there exists in the series a branch product,uranium-P, similar in chemical properties to, but not identicalwith, uranium-X, of half-period 1.5 days, giving soft 8-rayssirnilam t o those given by uranium-X1, as we now know.15This observation has been called in question, but repeated andreaffirmed by the original diacoverer,16 who states that the pro-portion of radiation contributed by uranium-Y is of the order tobe expected if it is the starting point of the branch actinium series.This has now been independently confirmed.*7 Not only has theabnormal decay curve of uranium-X been obtained, but also someevidence of a corresponding abnormality i n the recovery curve ofpure uranium preparations, both quite in keeping with the viewthat-of the total soft p-radiation of uranium-X, some 8 or 10 percent., is produced by a separate product of much shorter period,uranium-P. However, uranium-P appears from this work t o benot merely chemically similar to, but identical or isotopic withuranium-XI.TVhether or no the effects are obtained depends nota t all on the particular chemical separation adopted, but only onthe time of accumulation of the products before separation. Theshorter this is, the greater is the small proportion of the effectdue to the shorter-lived minor branch product. This probablyaccounts for the difficulty experienced by others in confirming thework. The direct production of two isotopes from one of the twouraniums indicates branching of the series by two simultaneouschanges, in both of which a-rays are expelled, as shown in Fig.2.Frc:. 2.(PI P a a Ur.-xl -+ Ur.-X2 --3 Ur.-II -+ 10 -+ RR, etc.(IV. 1 (V.) (1’1.) (IV.) (11.) 4 F Ur.-?L (V.1It will be observed that there is still a missing member, calleduranium-2 in the figure, to be found, which should be isotopic withuranium-X2, and should give actinium as the direct product in ana-ray change. But whether the branch occurs, as shown, a t the firstmember, uranium-Z, or a t the fourth member, uranium-ZZ, would beIri Ann. &port, 1911, 288.Ifi A. Fleck, Phil. Mag., 1913, [vi], 25, 710 ; A . , ii, 464 ; G. N. Antonoff, ibid ,1913, [vi], 26, 1058 ; A . , 1914, ii, 17.F. Soddy, ibid., 1914, [vi], 27, 215RADIOACTlVlTY. 269experimentally indistinguishable, save by indirect methods, suchas the determination of the atomic weight of actinium and itsproducts.The scheme shown would make the atomic weight ofactinium 230, whereas the alternative would make it 226, identicalwith that of radium.A generalisation in this field favours the latter alternative.18 Asa rule, in any group of isotopes, the a-ray giving members are themore stable the higher the atomic weights, and the &ray givingmembers are the more stable the lower the atomic weight. Thus,in the thorium group, the order of increasing stability and atomicweight among the a-ray members is: radiothorium (2.9 years, 228),ionium (100,000 years, 230), thorium (4 x 1010 years, 232). Sinceradioactinium is the least stable of all in this group, its atomicweight ought to be less than 228.From this generalisation theatomic weights of actinium aiid its products generally appear t obe similar t o that of radium and its products. The generalisationdoes not hold without exception, the niost notable being polonium,which a t once is the most stable and has the smallest atomic massof the six a-ray giving members of this isotopic group.ATature of the End-Products.-The connexion between thechanges and the properties of the products enables the placeoccupied, and the whole chemical character of those members, to bepredicted without uncertainty, in the case where, either by reasonof excessive instability-the d - and C"-members-or excessivestability-the end-products-the elements are outside the range ofexperimental investigation.Hitherto there has been a generalbelief that the end product of radium was lead, but there was noevidence whatever as to the nature of the end-products of actiniumand thorium. Fig. 1 shows that all the five end-products fall intothe same place, and must be the isotopes of lead. The calculatedatomic weights of the two end-products of the thorium series arethe same, namely, about 208, and that of the main end-product ofuranium is 206, whereas in the international list the atomic weightof lead figures as 207.1. This raises directly the question of thehomogeneity of lead, for if it were a mixture of the end-products ofuranium and thorium in similar proportion, the atomic weightwould be about that actually found.On the other hand, if thegeneralisation of Fajans holds good, it is to be expected that thestability of these various isotopes will be connected with theiratomic weight. I f , for example, the two supposed end-products ofthe thorium series, like the corresponding product, radium-D,expelled a P-particle in furvher very slow changes, the productlS K. Fajans, Le L!adiz6m, 2913, 10, 171 ; A . , ii, 660; Pl~pikal. Zeitsch., 1913,14, 951 ; A . , ii, 908270 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.would be, in chemical character and atomic weight, the same asbismuth; but as in the formation of these two products from theoriginal parent substances different energies have been lost, the twoisotopic bismuths so formed would not bs identical, and one ofthem might further expel an a-particle t o give thallium (204), forboth bismuth and thallium occur in radioactive minerals.This,of course, is a pure speculation. The interesting point is that, instability, the supposed end-products of the thorium series should beintermediate between radium-D and radium-G, and, theref ore, mightnot be sufficiently stable t o accumulate in minerals and t o constitutea perceptible fraction of the lead occurring therein. So that,although the atomic weight of lead, from radioactive sources asdifferent as possible in regard to uranium and thorium content andgeological horizon, should be re-examined, it by no means neces-sarily follows that any difference in atomic weight will be found.Branching of the Actinium Series.-The earlier observation,which made it appear that actinium-C gave out two types of a-rays,like thorium-C, but unlike in possessing ranges nearly the same,19has not been confirmed.I n Fig. 1 the actinium series is representedas unbranched a t the C-member. Without prejudice to this point,it appears certain that, if not the whole, a t least very nearly thewhole, of the actinium-C atoms disintegrate by the a-ray mode, andwhat is, in this series, overwhelmingly the main branch is theminor branch in both the radium and thorium series. Recentlysome evidence of a branching ha,s been obtained, precisely analogoust o that which occurs in the other two series.Z0I n addition t o the a-rays, from actinium-C, of range 5.12 cm.inair a t N.T.P., about one in 600 have been found of longer range,6.1 cm. This is very nearly the range of the a-rays of actinium-A.It must be remembered that recoiled actinium-X is always presentin the active deposit of actinium, as ordinarily prepared?’ so thatfurther discussion may be postponed.The Structure of the Atom.On Rutherford’s theory of atomic structure,22 which was putforward to account for “single scatkring”-that is, for thelarge angles through which a very small proportion of thea-particles are deflected in their passage through matter, by rare,exceptionally close, $ngle encounters with atoms-the mass of theatom, in association with positive electricity, about one unit of19 Ann. Beport, 1909, 236.2” E. Marsdennnd R.H. Wilson, Nulure, 1913, 92, 29.21 Ann. RGport, 1906, 363 ; 1907, 328 ; 1909, 246.a I b i d . , 1911, 273RADIOAC'I'IVI~I'Y. 21 1charge per two units of mass, occupies a single central nucleus ofexcessively minute dimensions, in diameter only one ten-thousandthof the atomic diameter. Around this nucleus a number of negativeelectrons, equal to the value of the positive nuclear charge, circulateas an outer ring or shell. This atom is, of course, n o t stableaccording t o ordinary electro-dynamical laws, for nothing apparentlyoperates to prevent the dispersion of the extremely concentratedcentral positive charge, but i t is now recognised that these lawsrequire modification. The model has been used with very con-siderable success, in conjunction with Planck's theory of quanta,and leads t o results, in connexion, for example, with the seriesrelationships of the hydrogen and helium spectra, in striking accordwith experimental determinations.23It now appears that the magnitude of this central positivecharge, in terms of the unit atomic charge, f o r example, that carriedby the hydrogen ion, is probably the same as what is convenientlytermed the '' atomic number."?* The atomic number is the numberof the place an element occupies in the periodic table, when thesuccessive places from hydrogen t o uranium are numbered insequence, hydrogen being unity, helium two, lithium three, and soon.If the eleven known representatives of the rare-earth group,between cerium and tantalum, exclusive, are all that exist, theatomic number for uranium would be 89.As regards the relativevalue of the nuclear charge, and its variation by units in passingfrom one place to the next of the periodic table, Fig. 1 shows thisclearly. The a-particle carries two positive atomic charges, andits expulsion causes the element to Eove two places in the table,that is, diminishes the atomic number by two. The 0-particle isan atom of negptive electricity, and its expulsion causes the elementt o alter its place by one in the opposite direction, that is, causesthe atomic number to increase by one, whereas the successiveexpulsion of two P- and one a-particle in any order brings theelement to the same place and with the same atomic number,therefore, as initially.The only assumption made is that both the a- and &particlesare expelled from the central nucleus, not from the outer ring.This is in accord with the view, everywhere accepted, that radio-active changes are much more fundamental in character than anyother known changes, aiid concern a region of the atom not affectedin ordinary chemical and physical changes.As, on the theory,the mass of the atom is concentrated in the nucleus, and the23 N. Bohr, P/i,iZ. Mag., 1913, [vi], 26, 1, 476, 857.24 A. van den Broek, Il'ature, 1913, 93, 373, 476; F. Soddy, ibid., 399, 4 5 2 ;E. Rutherford, ibid., 423272 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTHY.a-particle constitutes an appreciable part of the atomic mass, therecan be little doubt that the a-particles have their origin in thenucleus.With regard to the fl-particles, something like a directproof has been obtained. If the &particles came from the outerring and were the same electrons as are concerned in electro-chemical changes of valency, the loss of two &particles byurcmium-X, in the formation of uranium-11 should be equivalentto the loss of two electrons by uranous salts in their electro-chemical oxidation to uranyl salts, and uranium in uranous saltsshould be isotopic with thorium. Uranous and thorium salts arevery similar in chemical character, but a recent examination showsthat they are readily separable from one another by chemicalmethods.25 Hence the positively charged nucleus of the atom mustcontain some negative electrons-at least six in the case of uraniumto account for the six @rays expelled during the disintegration-which are t o be distinguished from the electrons in the outer shell.If the mass of the uranium atom were due entirely t o potentiala-particles or the nuclei of helium atoms, for which unit chargecorresponds with two units of mass, there would be about thirtynuclear electrons t o give 89 as the atomic number, whereas if, ashas been surmised, the hydrogen nucleus were a second constituentof the nuclear structure, more must be postulated, as in this caseunit mass goes with unit charge.It is the difference betweenpositive and negative charges which gives the atomic number orthe position of the element in the periodic table. Isotopes areelements f o r which the algebraic sum of opposite charges is the same,but the arithmetical sum i s different.The surprising results in crystalloqraphy and chemistry followingupon the discovery that the X-rays are regularly reflected bycrystals 26 are discussed in the report on Mineralogical Chemistry.Equally remarkable are the results in the field under discussion,for the property has enabled the wave-length of the X-rays, whichis the order of ten thousand times smaller than that of visiblelight, t o be determined.Each element gives a homogeneouscharacteristic X-radiation, and the wave-length of this characteristicradiation, equally with the wave-lengths of the luminous spectrum,is connected, by Bolir’s theory, with the magnitude of the nuclearcharge.The series of metallic elements from calcium t o zinc inthe periodic table, for which the atomic numbers extend from20 to 30, were all in turn, excepting scandium, made the anti-cathode of an X-ray tube, and the spectrum in each case wasfound, by reflection from a crystal surface, to consist of two linesonly, one strong and one weak. The wave-length of the stronger25 A . Fleck, T., 1914, 105, 247. 26 A m . Report, 1912, 302ILADIOACTJ VI‘L’Y. 273lines corresponded with the atomic numbers 19 t o 29, showing unitdifference of nuclear charge from place to place. What will be oneof the most interesting points to chemists is that the nuclear chargeincreases in the order: iron, cobalt, nickel, which is the order theelements should be placed in the periodic table, and not in theorder of the atomic weights: iron, nickel, cobalt.This is a definiteproof that the ‘‘ exceptions” to the sequence of atomic weights inthe periodic table are real, and not due t o erroneous deter-minations.2T Much remains, obviously, to be worked out in thisnew field, but the results attained are sufficient to demonstrate howmany novel methods of surprising power are converging simul-taneously on the outstanding problem of the structure of atoms.Behaviour of Radio-elements in Solution, and to Solvents.Advantage has been taken of the fact that none of the knowncakions differ widely in mobility, and that the diffusion coefficient,in the presence of great excess of anion, varies inversely as thevalency, in order t o determine the valency of the radio-elementsfrom diffusion experiments.28 The first series of determinationsgave results for the valency in accord with the chemical characterf o r those radio-elements which had already been placed in theperiodic table.Radium-E and the C-members, however, appearedt o act as bivalent, and the B-members as univalent, when firstdetermined by this method, in apparent disagreement with theisotopism of these elements to bismuth and lead respectively, asshown by the chemical examination published at about the sametime. Later a re-examination gave values in accordance with thechemical evidence.29 It was shown that, for example, thorium-B incertain circumstances acts as a univalent ion in the same way aslead does in the ion PbCl+.The chemical identity of isotopes has been extended to includethe electro-chemical behaviour.The decomposition voltage curvesfor thorium-C and radium-E are the same as that of bismuth, andfor thorilxm-B as that of lead. I n addition thorium-B may bedeposited on the anode under the same conditions as lead in theform of peroxide.30 By the use of bhese radioactive substances asindicators, the behaviour of lead and bismuth for electrode potentialslying a.bove the decomposition voltage has been studied. I n theelectro-deposition of radio-elements, the electrode potential is ofthe first importance. The passage of the current, and hence the27 H. G. J. Moseley, Phil. May., 1913, [-.i], 26, 1024.28 G.von Hevesy, YlL~ysikrtZ. Zeitsch., 1913, 14, 49 ; A . , ii, 174.30 F. Pniieth mid G. von Hevesy, Xuiinlsh., 1913, 34, 1593 ; A., ii, 1009.I d e m ihid., 1913, 14, 1202 ; A . , 1914, ii, 16.nP,P.-voL. x 274 ANNUAL REPORTS O S THE PROGRESS OF CHEMISTL1Y.diflerence between anode and cathode are entirely secondary. Inpractical electrochemical separations of one radio-element froinanother the addition of a perceptible amount of the isotope of theelement it is not desired t o separate is recommended. For example,in separating the B-members from the C-members, addition of leadhinders the deposition of the former, and results in a purer pre-paration of the C-member. An extended attempt to alter theconcentration of radium-l) t o lead in a mixture by fractionationwas unsuccessful. About twenty different methods failed t o affectthe least change in c0ncentration.3~ This identity of behaviourhas been made use of in the determination of the solubility of theexcessively insoluble compounds of lead, such as the chromateand sulphide.To the lead is added a quantity of radium-D,infinitesimal in amount, but, after the formation of the productsradium-E and -P, possessing intense radioactivity. The activityof the evaporated saturated solution of the insoluble lead compoundenables the amount of lead present to be estimated, though thisis analytically undetectable. I n this way, the solubility of leadchromhte in water a t 2 5 O was found t o be 0.012 milligram perlitre, and of lead sulphide, 0.3 milligram in water and 0.15 milligramin a saturated solution of hydfogen sulphide.Similar experimentscould be carried out with thorium, radium, or bismuth, usingionium, thorium-X, or radium-E, respectively, 2s indicators. Thepossibilities of the method are very numerous.32Two lines of work indicate that the radio-elements, althoughpresent in such infinitesimal concentrations, often behave in solutionsas colloids rather than as electrojytes. Thus polonium may beseparated from lead, radium-D and -E, by dialysing the solutionthrough animal membranes, or thin parchment paper. Thepolonium remains behind in the cell in a pure condition.33This may be used t o effect the separation, but on a large scalethe process recommended is the crystallisation of the hot saturatedsolution of the radio-lead nitrate solution, and electrolysis of themother liquor, after addition of a little bismuth, between platinumslectrodes, with a cathode potential not exceeding 0.08 volt, orcurrent strength 0.16 milliampere per sq.cm. The polonium isremoved from the electrodes by volatilisation a t 1000°. The vapourcondenses preferably on palIadium or platinum, especially theformer, rather than on other metals or on quartz, and so may be~oncentrated.3~F. Paneth and G . von Hevesy, rlionalsh., 1913, 34, 1393 ; A., ii, 1008.33 Idem. ibid., 1913, 34, 1401 ; A., ii, 1075 ; arid G. von Hevesy, Blitish33 F. Paneth, Monatsh., 1913, 34, 4bl ; A., ii, 273.34 F. Paneth and G . von Hevesy, ~?Ionntslz., 1913, 34, 1605 ; A., ii, 1011.Association, paper rend before 8;ction B, Birmingham, 1913RADIOACTIVITY.275I n acid solution, all the radio-elements dialyse normally ascrystalloids; in neutral solution the velocity of dialysis in thecase of polonium and radium-E, and in ammoniacal solution in thecase of thorium-B also, is very much reduced. The diffusion-coefficients in acid, neutral and alkaline solutions of these elementsbear out the conclusions drawn from the results of dialysis. Thechange from crystalloid t o colloid is accompanied by a change ofsign of the charge carried by the particles, the colloidal particlesnow migrating to the anode in an electric field. I n a conditionwhere both forms of the same radio-element exist together insolution, the migration of the ions to the cathode is not prevented,but only hindered, by the insertion of a parchment membrane, butthe migration of the colloid particles to the anode is almost com-pletely prevented by the membrane. The size of the colloidalparticle is probably very small, and i t consists of an aggregation ofbut few atoms compared with ordinary colloidal particles. It isaltogether beyond the range of the ultra-microscope.This is t o beexpected in view of the excessively attenuated concentrations.When it is remembered that in none of these cases is the solutiona saturated one, and, even for the most insoluble, the solubilityproduct of the ions is very far from being approached, it is clearthat the aggregation cannot be due to purely physical causes, butthat some unknown chemical or adsorption phenomena are involved.Zsigmondy has suggested that the colloidal particles may be formedby the adsorption of the radio-element by existing colloid particles,such as aluminium hydroxide o r silica, derived from the materialsof the containing vessels.This explanation necessitates the specificadsorption by the colloid particles of some of the radio-elements,and not of others. A closer examination of the adsorptionphenomena ,of the radio-elements is therefore called for. Alongthese lines may be expected an explanation of the very inexplicablefact that the radio-elements show such definite analytical andchemical reactions a t such infinitesimal concentrations.34aI n the other research, it was found that the ratio of cathodeto anode activity, obtained by the electrolysis of water containingdissolved radium emanation, could be varied in the proportion of40,000 to 1 in a manner impossible to account for if the products,radium-A, -B, and -C existed as ions, but completely in accordwith predictions made from the theory of colloids.I n pure water,the A-rnember is deposited on the anode, the B-member on thecathode, and the C-member on both electrodes, and the view talcenis that the A-member exists as a positive hydrosol, the B-member34a I?. Paneth, KoZZoid.;Teitsch., 1913,13, 1, 297 ; d., ii, 747 ; 191 4, ii, 19 ; I<. Fajansand P. Beer, Bcr., 1913, 46, 3456 ; A . , ii, 1010.T 276 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.as a negative hydrosol, and the C-member in both forms.Theaddition of acids containing hydrion, or much more powerfully, ofa multivalent cation such as that of aluminium, stabilises thepositive hydrosol, whilst it neutralises and ultimately reverses thesign of the negative hydrosol. Basic ions, such as hydroxyl, or thecitric acid anion, act in the opposite ma.nner. I n this way thedeposition on either electrode may be suppressed, and that on theother accentuated. The transport of the products by the currentis regarded as being due t o electrophoresis rather than to electro-lysis.35An interesting series of experiments on the solubility of theactive deposit of radium deposited from the emanation on surfacesof glass and metals, showed that from a glass surface only one-halfof the active deposit is removed by boiling with acids, whereas withgold and platinum surfaces the soluble part is greater.36There is little doubt that the recoil of the atom of radium-B inits production from radium-A must drive one-half of it to a perceptible depth beneath the surface, where it is protected from theattack of solvents.With radium-B deposited on a second plate,by recoil from the first, the whole is soluble. I n organic solvents,especially carbon disulphide, radium-A is soluble, whereas the othertwo members are nearly insoluble. This is in accord with theposition of radium-A in the sulphur family. When the activedeposit is formed on plates of gold and platinum, which have beenpreviously saturated electrolytically with hydrogen and oxygenrespectively, i t was found that oxygen diminishes the solubility,especially of radium-G, whilst hydrogen diminishes that of radium-A .It will be recalled that in oxygen the volatility of radium-C occursat a very much higher temperature than in hydrogen.37 Theformula of Arrhenius for the variation of velocity of solution ofmetals in acids with temperature has been tested for the radiumactive deposit, and has been found to hold approximately.Asimilar series of experiments with the active deposit of thoriumshowed that thorium-B is dissolved more quickly than thorium-C bywater, salt solutions, alkalis and acids, but less quickly by organicsolvents.38Radium.Atomic TVe;ght.-The value found for the atomic weight ofradium by analysis of the chloride,39 225'95, was confirmed by35 T.Godlcwski, Le I:ndinm, 1913, 10, 250 ; A , , ii, 1011.zG I?. Ranistedt, ibid , 159; A . , ii, 659.:;7 AWL. Report, 1912, 318.38 C. F. Hogley, Phil. Mag., 1913, [vi], 25, 330; A . , i;, 273.39 Compnse Ann. Report, 1912, 289RA DIOACTIVITP. 277converting the material into the bromide, and fractionally crys-tallising it numerous times. The value found in one set of deter-minations from the ratio RaBr,/AgBr was 225.96, and in another,from the ratio RaBr2/Ag, 225.97. A spectroscopic examination ofthe final product showed no trace of baxium. I n the motherliquors, barium was detected, aDd irCs quantity estimated as 0.03 percent. From this it is calculated that in the preparations usedthe percentage of barium in the chloride could not exceed 0.004,and in the bromide 0.002, which is insufficient to affect the accuracyof the atomic-weight determinations.A similar degree of puritymay be assumed for the International Standard, so that, beforethe barium can cause any error, the radioactive methods of com-paring standards must be increased in accuracy a h u n d r e d f ~ l d . ~ ~The atomic weight being so near the whole number suggests thatthe atomic weight of uranium should be very nearly 238 insteadof 238.5, as in the international list, if mass is conserved in radio-active changes.Vn2ency.-The bivalency of radium has been shown by a newmethod, depending on the volume of liquid transported in acapillary tube by electric endosmose, under the application of con-siderable electric potentials.The interest of the method consists inthe excessively minute amounts, 0.01 to 0.001 milligram of sub-stance required.41Estimation.-A method for the rapid estimation of radium bythe emanation method depends on the use of a micro-furnace, inwhich a tiny fragment of the mineral is heated for a few secondsto 2000° or 3000O in a cavity in a thin carbon rod, inside a smallchamber provided with a rubber balloon to allow f o r expansion.Rapid escape of emanation commences a t 750°, and is complete a tbright rednew42Technical Extraction.-The reductioii of the radiferous (I rawsulphates” has been effected by mixing the absolutely dry, finelypowdered material with finely powdered calcium hydride, andfiring the mass with magnesium ribbon and a priming mixture, asin the thermite reaction.The reduction is complete in a fewminutes, and the product is leached out with acid as quickly aspossible to avoid oxidation of the sulphides with air.43 It may bedoubted whether such a reaction could be technically advantageouson account of the high cost of the reducing agent.40 0. Honigschmi~l, Mmzntsh., 1913, %, 283 ; E. Haschek and 0. Hoi~igschniicl,ibid., 351 ; A . , ii, 268 ; S. Meyer, Plzysiknl. Zcitsch., 1913, 14, 124 ; A . , ii, 267.41 H. Fleundlicli and G . von Elisafoff, Plzysilcnl. Zeitwh., 1913, 14, 1052 ; A . ,ii, 1008.42 A. L. Fletcher, Phil. Mag., 1913, [vi], 26, 674 ; A., ii, 904.43 E.Ebler and W. Bender, Zeitsch. anorg. Chenz., 1913, 83, 149 ; A . , ii, 904278 ANNUAL REPORI’S ON THE PROGRESS OF CHEMJSTRY.Uranium-Rdium Ratio. -A new determination of the ratio ofradium to uranium in a variety of minerals, in which the uraniumwas estimated chemically and the radium by both the emanationand y-ray methods, by the use of standards checked against theinternational standard, gives the value 3.328 x 10-7.44 A review ofall the evidence available by which the periods of uranium andradium may be calculated has shown that the different methodslead t o substantial agreement, and that the half-periods, respec-tively, are 5 x 109 and 1730 years, corresponding with the average-life periods, 7.25 x l O Q and 2500 years.45 The half-periods forthorium and uranium, calculated from the range of the a-particleand the ionisation per unit weight, have been independently foundto be 1.8 x 1010 and 5 x 109 years.46Various.-The effect of very low temperatures on the penetratingradiation from radium has been carefully studied. Immersion for1.5 hours in liyuid hydrogen did not produce any variation attain-ing 0.1 per cent., and probably not 0.02 per cent.47 By an ingeniousapplication of the principle of the radium-clock, in which thenegative charge, carried by the penetrating rays, is used to chargea tube containing radium positively, very high potentials havebeen obtained.A tube of radium emanation was suspended byan insulating support in a high vacuum, and the potential itattained measured by a simple form of attracted disk electrometer.The tube quickly charged itself to a high potential.I n spite ofall precautions to obtain as perfect a vacuum as possible, theattainable potential was limited to a maximum of about 150,000volts, at which a discharge always occurred.@The Actinium Series.Period of Actinium-X.-A small change has to be recorded inthe period of actinium-X, which still, however, remains an exceptionto the Geiger-Nuttall relation, the earlier reported resolution ofradioactinium into two products having been withdrawn.49 Fromj3-ray measurements, the half-period of actinium-X, very carefullypurified, was found to be 11.6 days, corresponding with the averagelife period, 16.8 days. For radioactinium the accepted values were4* B.Heiiiraiin and W. Mai~ckwald, Phvsiknl. Zeitsch., 1913, 14, 303 ; Jahrb.45 S. Meyer, Sitzurrgsbcr. K. Akncl. Wiss. Wien, 1913, 122, (iia), 1087. * H. Ar. McCoy, Physical Reriew, 1913, 1, 393.47 Mme. M. Curie and H. K. Onnes, Lc Radium, 1913, 10, 181; A., ii, 746. * H. G . J. Moseley, Proc. Roy. S’ooe., 1913, A, 88, 471.4g Ann. Rcport, 1912, 294 ; 0. Hahn and L. Meitner, PhFsikal. Zeitsch., 1913,14, 752 ; A . , ii, 821 ; A. S. Russell and J. Chadwick, 1’hiZ. Mag., 1911, [vi], 27,112.Knclioakt. Eleklronik, 1913, 10, 299 ; A . , ii, 374RADIO ACT1 VITY, 279confirmed (19.5 and 28.2 days).50 No 8-radiation could be detectedfrom the very carefully purified actinium. I n another deter-mination, by a-ray measurements, the value 11.35 days for thehalf-period of actinium-X was obtained.51a-Ray s.Experiments on the scattering of the a-rays by gases 52 and metalfoils53 have been continued, with results in agreement with therequirements of Rutherford’s theory of the structure of the atom(p.270). The theory has been quantitatively tested, as regardsthe variation of the number of a-particles deflected when (1) theangle of scattering, (2) the thickness of the foil, (3) the atomicweight of the scattering material, and (4) the velocity of the a-raysare varied. Although the results are approximately in agreementwith the view that the positive nuclear charge is one-half of theatomic weight, i t is probable that they would be more perfectlyin agreement with van den Broek’s view that the charge is equalto the atomic number, which for heavy elements is somewhat lessthan half the atomic weight.Attention may be directed to a comparison of the ranges of thea-rays of radium4 and polonium in hydrogen and helium respec-tively,54 since this is, theoretically, a very interesting case of adenser gas allowing the a-particles t o travel in it slightly furtherthan in a lighter gas.The ranges of the a-ray of radium-C in thetwo gases a t N.T.P. are, respectively, 29-36 cm. in hydrogen, and30-84 cm. in helium. This furnishes the simplest possible proof,as previously pointed out, of the monatomicity of the heliummolecule. For, on Bragg’s law, the atomic stopping power isapproximately proportional tp the square root of the atomic weight.If the helium molecule is monatomic, the number of atoms in thepath of the a-ray will be twice as great in hydrogen as in helium,and the stopping power of each atom twice as great in helium asin hydrogen, whereas any other assumption must make the rangein helium less than in hydrogen.Pleochroic Haloes.-An attempt has been made to arrive a t theage of the pleochroic haloes occurring in the mica of Haughtonite,co.Carlow, which contains no thorium haloes, but numerousuranium haloes of all stages of development, from the smallest, dueXI 0. Hahii and M. Rothenbach, PhysilcaE. Zeitsch., 1913, 14, 409 ; A., ii, 463.51 H. N. McCoy and E. D. Leman, ibid., 1280 ; A . , 1914, ii, 17.52 $1. Rutherford and J. M. Nuttall, Phil. Mag., 1913, [vi], 26, 702 ; A.,53 H.Geiger a i d E. Marsden, ibid., 1913, [vi], 25, 604 ; A . , ii, 371.5p T. S. Taylor, ibid,, 1913, [vi], 26, 402 ; A., ii, 899.ii, 898280 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to the rays of uranium and ionium only, to the largest due t o thefully darkened haloes, completed to the range of the a-rays ofradium-C.65 The number of a-particles required to produce acertain density of staining in the mica was experimentally deter-mined, the mass of the nucleus giving the halo was estimatedmicroscopically from its dimensions, and the quantity of radiumper unit of mass assumed from analogy to the radium content oflarge zircons and cyrtolite. The last is, of course, the uncertainfactor, and the results were dealt with in all cases to yield thelower limit possible for the age.The results are interesting in thatthey confirm the somewhat excessive periods of age given by thehelium and lead contents of uranium minerals. The haloes maymost safely be regarded as of early Devonian age, and the resultspoint t o a period of not less than four hundred million yearsas being required in their formation.P-R nys.The analysis of the slower &rays given by radium-B andradium-l) showed in each case four distinct beams of velocity, interms of that of light, 0.361, 0.362, 0.412, 0.422 for the first, and0.342, 0.344, 0.390, and 0.402, for the second substance. Thedifferences between the energies of the several groups of rays arethe same for each substance, within the error of measurement.This leads t o the conclusion that in each case the rays are producedby the same mechanism.56 Taken in combination with the isotopismof the two substances, the result is very suggestive.An exhaustiveanalysis has been made of the very complex @radiations ofradium-B + -C, from photographs taken by a new method, whichenables a comparatively wide slit to be employed without loss ofsharpness.57 The velocity and energy for 16 lines from radium-Band 48 lines from rsdium-C' have been tabulated.With regard t o radium-B, no lines were observed with a velocityabove 0.832, although i t is probable that faster beams exist whichare masked by the stronger lines of radium-C. The slowest lineobserved had a velocity of 0.365.Two complex groups of lowvelocity lines shown strongly by radium-B were shown faintly byradium-C. F o r radium8 29 lines were observed over the range ofvelocity from 0.9858 to 0.946, the energy of which were all integralmultiples of E'( = 0.428 x lO13e). The integers were the alternateodd integers from 59 t o 47, and, with the exception of 45, every55 Ann. Report, 1910, 260 ; J. Joly and E. Rutherford, Phil. Mng., 1913, [vi],56 J. Danysz, Ls RndizLm, 1913, 10, 4; A., ii, 270.57 E. Rutherford a i d H. Robinson, Phil. Hag., 1913, [vi], 26, 717 ; A . , ii, 899.25, 644RADIOACTIVITY. 281integer between 46 and 24. Below this, the differences of energybetween the lines were much smaller, and the plates were crowdedwith fine lines extending right into the low velocity regions whereradium3 shows strong lines.No simple relation appears to holdbetween the energies of the radium-B lines. This is probablyconnected with the fact that whereas the y-radiation from radium8is homogeneous, that from radium-B consists of three widely-different types. The quantity E represents, on Rutherford's theoryof the origin of y-rays, the ecergy abstracted from the &particlein passing through certain regions of the atom and converted intoy-ray energy.There is one point of interest in connexion with the expulsion ofa-rays. I n the c=es most closely studied the recoil product alsocarries a single positive charge,58 so that three positive chargesresult. Two of these are accounted for by internal compensationwithin the atom, the outward sign of which is the shift of twoplaoes in the periodic table.The third is not yet accounted for.An attempt to detect the expulsion 03 a soft 8-ray from radium-Aled to no re~ult.5~ It is quite possible, however, that the thirdpositive charge may be compensated for by the loss of a 8-ray,which would not be detectable in ordinary circumstances.Radium,GO thorium-X, and radioactinium do give soft 8-rays inaddition to a-rays, and only the latter are accounted f o r in.thechange of place in the periodic table. On the other hand, the tworayless changes, of mesothorium-Z and actinium, are equivalent to8-ray changes in the alteration of place they produce. These points,which are of the nature of exceptions t o the simple generalisation,call for fuller examination.y-Rays.The chief centre of interest in the physical examination of thevarious types of rays has been successively, first the a-rays, thenthe 8-rays, and now the y-rays.On the one hand, the view hastriumphed that the y-radiation is essentially homogeneous. Thisview was put forward a.fter the exhaustive examination of they-rays of radium in various materials, from a thickness equivalentto 1 cm. of lead up to 22 cm. A repetition with larger quantitiesof radium, in which mercury was used as the absorbent, showed astrictly exponential absorption between the thickness of from 1 to22.5 cm. The value found for p/d, the absorption-coefficient68 Ann. Report, 1910, 272 ; H. P. Walmsley, Phi?. Mag., 1913, [vi], 26, 401 ;59 W.Makower and S. RUSS, Proc. London Phys. SOL, 1913, 25, 253 ; A4., ii, 654.6o Compare L. Kolowrat, Le Radium, 1913, 10, 280,A., ii, 905282 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.divided by the density, was 4.38 x 10-2(cm.)-1, in almost absoluteagreement with the former value found for lead.61 No evidence ofan ionising radiation more penetrating than the known y-rays wasobtained. Through 30 cm. of mercury it can be calculated thatno radiation could be detected, even from 10 grams of radium, sothat it would be thought that the equivalent of the 76 cm. whichsurrounds us as an atmosphere must screen us absolutely from anycosmical source of y-rays that exi& (p. 288).On the other hand, the departure of the absorption curves fromthe simple exponential type, for small thicknesses of material, hasbeen shown to be due to the existence of a large number of typesof homogeneous y-radiation, varying in penetrating power fromthose of thorium-D, for which p / d is 3.5 x 10-2(cm.)-lJ to one ofthe types given by radium-B, f o r which p / d is 85, which are hardlymore penetrating than a-rays.62 So that, just as in the case of the8-rays, fuller examination has shown that the most obvious morepenetrating types are by no means the only ones that exist.Twentytypes have so far been distinguished, as set forth with the valuesof p / d in aluminium for each type, in the following table:Element. At. wt. p/iE (Al).......... ;::; ] Radium-B 2140,188Kadium- C ......... 2 14 0.0424Radiurn-D .........210 16.50.36)Radium-E ......... 210 similar toradinm- D, bntvery feebleMesothoriurn-11.. 228Element. At. wt. p/d ( A l ) .Thorium-B ...... 212Thorium-D ...... 208 0.035Radio-actinium , , , -Actiiiiurn-H ...... -0'130'165Actinium-D ...... - 0.073Four types may be distinguished in descending order of pene-trating power : (1) The known, or old-fashioned, most penetratingtype, with p / d varying from 0.035 to 0.073. The elements longknown as y-ray producers, radium-C, thorium-D, and actinium-Dare unique in giving only this single homogeneous type. I n additionmesothorium-11 and radioactinium give a y-ray of this type, in eachcase accompanied by another of type (3). (2) Next in penetratingpower are some fairly penetrating rays, for which p / d varies from0.13 to 0.188 given by the B-members only and (4) feeblest inpenetrating power of all another set, ,u/d 44 to 85, also given onlyby the B-members.There remains to consider (3) a type, with,u/d varying from 9.2 to 16.5, given by all the elements which61 A. S . Russell, Proc. 309. Soc., 1913, A, 88, 75; A., ii, 270; compare alsoA. Eronimer, Sitzzswpber. K. Akncl. lt'iss. Wien. 1012, 121, [iin], 1563.m E. Rutherford and H. Ricliardson, Phil. LWcbg., 1913, [vi], 25, 722 ; 26, 324,937 ; A., 1913, ii, 461, 901 ; 1911, ii, 13RADIO ACT1 VITY. 283give y-rays a t all, except radium-C, thorium-D, and actinium-D.This type is probably the characteristic X-radiation of the respectiveelements of the L-series, type (1) being probably also characteristicX-rays of the R-series.Type (3) are all less penetrating thanhard 8-rays and than the X-rays of an average tube. Type (4) areof the same order of penetrating power as low-velocity P-rays, andare not greatly superior in this respect to a-rays.Thorium-X also gives a soft y-radiation, intermediate in pene-trating power between the 8- and y-rays of thorium-D.a Ifthorium-C, which gives the greater and more penetrating part ofthe &rays of thorium-R +-C, gives any y-radiation a t all, it mustbe of exactly the same penetrating power as that of thorium-D.Radium, which, like thorium-X, is anomalous in giving some soft&rays as well as a-rays, has now been found to emit y-rays also, ofintensity about 1 to 1.5 per cent.of that emitted by radium inequilibrium with radium-B + G . 6 4 The radiation appears to consistof three types with ,u/d 130, 6, and 0.1.Further details have been published of the y-rays excited by thea-rays in elements of high atomic weight,65 and evidence of suchradiation obtained for radiothorium as well as from ionium. Poloniumemits a single type of y-radiation (p/d=215) due to the poloniumitself. When deposited on copper, but not on aluminium, lead, orplatinum, a second y-radiation is present, which is probably thecharacteristic radiation of copper, in the L-series. A very smallquantity of @-rays is also emitted from polonium, which could notbe ascribed to impurity.No doubt, when all the details are worked out for the 8- andy-rays, much new light will be thrown on the structure of the atomand the mechanism a t work in radioactive processes.A beginninghas already been made in the method of studying y-rays byreflection from crystal surfaces. The y-rays from radium-B(p/d=14*7) are reflected from a rock salt crystal at angles between8O and loo, as a group of fine lines, whereas another series of finelines were observed reflected a t an angle of about 2O, probablyresulting from the more penetrating rays of radium-B and -C.@63 L. Meitner and 0. Hahu, Physiknl. Zeil9ch., 1913, 14, 8’73 ; A., ii, 906.6J A. S. Russell and J. Chadwick, Phil. Mag., 1914, [vi], 27, 112.65 A7m Report, 1912, 300 ; J. Chadwick, ibid., 1913, [vi], 25, 193 ; A .,ii, 91 ; J. Chadwick and A. S. Russell, Proc. Roy. Soc., 1913, A, 88, 217 ; A . , ii,372; Phil. May., 1914, [vi], 27, 112.E. Riitherford arid E. N. da 0. Andrack, Nature, 1913, 92, 267284 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Trans mu ta tio nal R eac tions.There is nothing new to report concerning the question of trans-mutational reactions produced by the radium emanation.67 On theother hand, the possibility of a synthesis of helium and neon underthe action of the electric discharge has been much discussed.Helium has been obtained from old X-ray bulbs, which, after pro-longed use, were broken up and heated to redness.68 The spectrumof the evolved gases, after treatment with cold charcoal, showed thehelium lines with great brilliance, and some of the brighter neonlines faintly. I n another experiment unopened X-ray bulbs wereconnected by rubber tube t o a pump, and, after exhaustion of theconnecting tube, communication between the bulb and pump wasestablished by breaking the seal under the rubber. The bulb washeated to 350° and washed cut with oxygen, which again showedthe presence of helium, and a just detectable trace of neon.Onthen breaking up these bulbs and heating them, no trace of gas,not absorbed by cold charcoal, was obt'ained. This makes it appearprobable that the helium is in some way produced by the dischargein the tubes, and only loosely held by the glass in a form readilyand completely removable by heat.The work on tlie production of neon by bombarding fluorite bycathode-rays, referred to briefly last year,69 has now been publishedin detail.70 It was found that neon was obtained, even in absenceof fluorite, when the discharge passed in hydrogen.The hydrogenwas exploded with excess of oxygen, and treated with cold charcoal.In one experiment the amount of neon was of the order of thatobtained in 1 or 2 C.C. of air-that is, of the order of 0.01 cu.mm.-but no nitrogen was found in the gas absorbed by the charcoal.Oxygen and hydrogen put through the pump in the same way asduring an experiment, without being submitted to the action ofthe discharge, gave no neon, neither could i t be obtained from theglass and electrodes by heating. From an exhausted bulb, heatedin the air t o the softening point., no neon was obtained, and to testwhether glass subjected to the cathode discharge might be poroust o neon, a bulb was completely surrounded by another attachedto a separate pump.The cathode-ray discharge was passed throughhydrogen in the inner bulb, with the outer bulb exhausted, for two67 Ann. &?port, 1909, 255.g* Sir Williani Ramsay, T., 1913, 103, 264.BY Ann. Report, 1912, 308. The reference there given to Sir William Ramsay'sletter to Nature, in wltich this iesult is quoted, is misleading in that i t oiriitted tomention that the autlinr of the work m:is Prof. Collie, who had not, a t the time,published the result himself.70 J. N. Collie and H. S. Patterson, T!, 1913, 103, 419HADIOACTIVlTY. 285days, and the usual amount of neon was found in the hydrogen.Now, however, the surprising observation was made that when theouter bulb was washed out with oxygen, a faint explosion on spark-ing showed the presence of hydrogen, and tlie residue, after coldcharcoal absorption, was about fifty times greater than the residuefrom the inner tube.This gas was mainly helium with enoughneon present to give the spectrum. A t this stage the author wasjoined by H. S. Patterson, who had obtained similar quantities ofneon independently, by very similar methods. Pure hydrogensparked in a Plucker tube and pumped out whilst the dischargewas continued showed, after explosion with oxygen and absorptionwith cold charcoal, the presence of neon, sometimes containinghelium, but always with the helium in much greater relativequantity than in the helium-neon mixture obtained by cold charcoalfrom air.The jacketed tube experiments were also repeated withthe same results, and i t was found that, when the outer tube con-tained oxygen, almost pure neon, instead of almost pure helium,was obtained from the gas in the outer vessel.I n continuation of the work,71 the joint investigators found thatelectrodes were not necessary for the production of neon, which wasformed in hydrogen, free from mercury vapour, submitted t o theelectrodeless discharge. The jacketed tube experiments were alsorepeated with the wires connecting the electrodes of the inner tubeencased in glass tubes. The apparent disappearance of 3.6 C.C. ofhydrogen under the action of the discharge was observed.Thegas from the outer tube, examined by filling the latter with mercuryand compressing the gas into a spectrum tube, gave a ((carbonspectrum.” On sparking, it decreased in volume, and the carbonspectrum disappeared. Even after absorption in cold charcoa1,which should leave pure helium and neon, this carbon spectrum isseen. The gas causing it appears to be highly uncondensable andnot readily oxidised, and it is suggested it may be the ‘(X3” dis-covered by Sir J. J. Thomson by his positive ray method. Anotherobserver, with the jacketed tube experiment, found only hydrogen,containing small and varying amounts of carbon monoxide, accumu-lating in the jacket after discharge in the inner tube. The pro-duction of neon from hydrogen sparked in the inner tube ceasedafter a time, but, on adding a mixture of hydrogen and oxygenand continuing the discharge, the production of neon recommenced.72These results have been given fully because it is difficult a t thepresent stage to compress or comment on them.That neon is notalways obtained by sparking hydrogen is shown by recent experi-71 J. N. Collie and H. S. Patterson, P., 1913, 29, 217.72 J. I. 0. Masson, ibid., 233286 ANNUAL REPORI‘S ON THE PROGRESS OF CHEMISTRY.ments, of which only the abstract is available a t the time of~ r i t i n g . ~ 3 This is in accord with experience of the writer with thecalcium method, in which the production of neon from hydrogenunder the electric discharge could not fail to have been observedif it were a general phenomenon.There must be some unrecognisedfactor contributing to the results. I n view of the care and circum-spection apparently exercised in the performance of the experi-ments, it would not be fair to conclude that the neon found mustnecessarily have been of atmospheri.; origin.Helium and neon have been commonly found in the positive-rayexperiments,74 but here, where apparently a continuous stream ofgas is kept passing through the discharge tube in connexion witha cold charcoal bulb, i t must be very difficult to be sure that theyare not derived from the atmosphere. I n these experiments it wasfound that the conditions which gave rise to a considerable amountof “X3” generally gave helium and neon also.The view nowmost favoured with regard to the nature of ‘‘ X3” is that it isprobably a modification of hydrogen (H3). It is obtained by thecathoderay bombardment of many substances, indeed, most sub-stances, but especially abundantly from potassium salts. Theproduction of hydrogen under the discharge in vacuum tubes isregarded as analogous to the production of “X3,” helium and neon,and the suggestion is made that they may represent abortiveattempts a t disintegration, analogous to those occurring in radio-active substances, in which the products require the assistance ofthe cathoderay bombardment in order t o get clear from the atomsproducing them.Chemical and Biochemical Effects of Badioactiz4ty.A very thorough investigation of the decomposition of water bya-rays has been made.For ice a t - 183O the products are hydrogenand oxygen in the same proportion as in water, but the amount ofdecomposition is only a twentieth as great as with liquid water.For the latter, 6.4 per cent. of the energy available is utilised inthe decomposition, and the number of molecules of water decom-posed is 6 per cent. greater than the number of ions produced by therays in air. A t first hydrogen is produced in excess with formationof hydrogen peroxide. Later there is a disengagement of excess ofoxygen. When the rays act on water in the state of vapour, theexcess of hydrogen attains 50 per cent. by volume.75These results therefore form an important confirmation of the73 Hon.R. J. Strutt, Proe. Eoy. Xoc., 1914, A . , 89, 499.74 Sir J. J. Thomson, Nnture, 1913, 90, 645.75 W. Duane and 0. Sclic uer, LG Acidii~iu, 1913, 10, 33 ; A , , ii, 270R A D I 0 A CTl VlTY . 287view that the number of molecules of liquid water decomposed bythe passage of an a-ray is approximately the same as the numberof pairs of ions produced by the u-ray in passage through a gas;or, in other words, if the ionisation current in the gas were expressedin faradays, the decomposition in liquid water would be expressedin moles.Researches on the decomposition of iodides by the penetratingradium rays have been extended to the iodides of the alkaline-earthelements, which show the same general behaviour as those of thealkali metals.76 Although the effects produced are of a smallerorder of magnitude than those observed with ultra-violet light, theyare of the same general character.Thus, with ultra-violet light,many organic acids in N/2- to 2N-solution were decomposed, aceticacid to the greatest extent, but with long exposures to the pene-trating rays of comparatively large quantities of radium, the effectsare excessively minute. Among positive actions of the latter maybe mentioned the reduction of silver nitrate solution to metallicsilver, the oxidation of ethyl alcohol to acetaldehyde and aceticacid, and the inversion of sterilised aqueous solutions of sucrose.77A further study has been made of the action of radium emanationon growing plants.78 A lasting injury is caused to the plant,whether the exposure is made to the seed or t o the seedling,provided that the emanation is of 'sufficient concentration, and thisin jury, unlike that caused by tobacco-smoke or coal-gas, continuesafter the plant has been brought into pure air.I n smallerquantities the emanatiori exerts in some cases a favourable influence.The injury extends not only t o the growing parts, but also to theorgans already developed, including the leaves. The fall of theleaves is, in certain cases, much accelerated by the emanation, andcan be made to occur in spring or summer, when under normalconditions no such tendency exists. Lastly, remarkable changessometimes occur in the character of the development. The budsof Sedi~m Sieboldii, instead of developing normally into trefoliatedwhorls, after exposure, i n a quite early stage of growth, to strongemanation for three days, develop with decussate pairs of leaves. I nsome ways the action of the emanation resembles that of a poison,but there is probably no poison knowii capable of producing suchgreat effects in such infinitesimal quantity.76 A~Lv. ILpoi-t, 1912, 323.77 A. I<nilan, Monatsh., 1913, 34, 359, 3209, 1245, 1269 ; A . , ii, 270, 1000, 1002278 H. Mol:sch, Silzungsber. K. Allad. 1Vis.s. ~ V ~ C I L , 1912, 221, [iia], 833.1003288 ANNUAL REPOEI'S ON THE PROGRESS OF CHEMISTRI'.T h e Penetrating Radiation of t h e Atmosphere.I n seven balloon ascents in 1912 measurements of the ionisationin a closed electroscope were carried out, and the results show thatthere is a very small decrease of the penetrating radiation between200 and 1000 metres, and then an increase, so that a t heightsfrom 1000 to 2000 metres the radiation has much the same valueas a t the surface. I n one ascent, in which a height of 5350 metreswas attained, a very considerable increase of the radiation wasobserved above 3000 metres, and the increase became very markeda t the greatest height attained. This increase above 3000 metreswas independently confirmed, and in 1913 in another voyage, inwhich 4160 metres was attained, the same slow increase from 2000to 3500 metres and rapid increase a t the highest level was observed,although the weather conditions were quite different from that ofthe earlier ascents. The conclusion is dra-wn from this that a verypenetrating radiation must enter the upper atmosphere from outsidespace, and cause part of the spontaneous iorisation in closed vesselsobserved a t the surface. This part is probably that for whichlarge and irregular variations have been noticed, but as nodiminution was observed in the ascents a t night and during a solareclipse, the source of this radiation can scarcely be the sun. It isestimated that only .one-twentieth part of the penetrating radiationobserved a t 1000 to 2000 metres height can be due t o the radium-6'in the atmosphere, assuming that this is no greater than a t thesurface. A t this height the rays from the earth's surface would beso much absorbed by the air as to be negligible. The conclusion isa somewhat sensational one. When it is considered that theatmosphere is equivalent to 76 cm. of mercury, and would reducethe y-radiation of radium to between 10-19 and 10-20 of the initialvalue, the assumption of an external radiation reaching the surfaceof the earth from outer space would seem t o involve the existenceeither of more penetrating rays than are yet known, or of cosmicalsources of radioactivity of unparalleled intensity.79FREDERICK SODDY.79 V. F. Hess, Sitz?oi,!ysber. h7. Akncl. W i s s Wicn, 1912, 121, [iia], 2@01 ; 1913,122, [iial, 1053, 1481

ISSN:0365-6217    

DOI:10.1039/AR9131000262

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

INDEX OF AUTHORS' NAMES.Abderhalden, E., 187, 188, 195, 196,Abel, E., 16.Acree, S'. F., 17, 99.Adams, L. H., 8.Ageton, C. N., 231.Agulhon, H., 230.Alexander, F. G., 208.Allen, I. C., 167.Amberger, C., 41, 76.Ambroz, A., 219.Amon, F. O., 170.Andrade, E. N. da C., 283.Anthes, E., 62.Antonoff, G. N., 268.Applebey, M. P., 5.Arbuzov, A. E., 146.Armstrong, E. F., 87.Armstrong, H. E., 13, 14, 86, 87.Aschan, O., 62, 118, 119.Ashton, F. W., 265.Aten, A. H. W., 12, 33.Auwers, K. von, 69.Bahr, F., 214.Baker, H. B., 34.Baldes, K., 197.Bamberger, E., 96.Bang? I., 191.Barbier, P., 74, 75.Barcroft, J., 191, 207, 208.Barker, T. V., 161, 248.Barkla, C. G., 239, 241.Bartlett, E. P., 177.Baskerville, C., 68.Batschinski, A. J., 5.Battelli, F., 208.Bandisch, O., 228.Bauer, E., 61.Baumann, A., 205.Baur, E., 74.Bayliss, W.M., 86.Becker, P., 136.Bedford, F., 67.198.Beer, P., 262, 275.BQhal, A., 115.Bekk, J., 178.Bell, J. M., 185.Bender, W., 277.Benedicts, C., 12, 18.Bertrand, G., 230.Besson, A. A., 173.Biltz, H., 56, 73.Biltz, W., 31, 37, 89.Bingham, E C., 5, 6, 7, 8.Bizzell, J. A., 221.Blanck, E., 231.Blendermann, K., 61.Bleyer, B., 44.Bloor, W. R., 203.Blum, W., 46.Blumenthal, P. A., 171.Bodenstein, M., 25, 26, 27.Rodroux, F., 69.Boeseken, J., 67, 79, 100.Bomer, A., 75, 183.Boer, R. B. de, 10.Bohr, N., 271.Bornemann, K., 174.Bosshard, E., 173.Boswell, M. S., 178.Bosworth, A. W., 191.Bottomley, J. F., 118.Bourquelot, E., 85, 86, 87.Bowen, N.L., 254.Bowers, P. C., 29.Bradley, W. M., 261.Brady, 0. L., 140.Bragg, W. H., 239, 240.Brag,g, W. L., 237, 238, 239, 240, 241.Brannigan, P. J., 64, 104.Bray, W. C., 20.Brenchley, W. E., 224.Breyer, F. C., 170.Bridel, M., 85, 86, 87.Briggs, T. R., 42.Briner, E., 49.Brock. F. P.. 181. I - ,REP.-VOL. X. 2S9 290 INDEX OF AUTHORS’ NAMES.Broek, A. van den, 271.Broglie, M. de, 241.Brommer, -4., 282.Broniewski, W., 43.Brown, 0. W., 46.Brown, P. E., 222.Bruin, G. de, 12.Bruni, G., 24.Bruylants, P., 29.Buchner, E., 115, 119.Burgstaller, A., 171.Burnett, H. R., 183.Busolt, F., 80.Bytebier, A,, 29.Cadwell, J. L., 6, 8.Cain, J. C., 107.Cain, J. R., 176.Campbell, C., 56.Campbell, F.H., 167.Campbell, J. M. H., 208.Cardwell, D., 91.Carr6, P., 76.Caw, W., 119.Chadwick, J., 278, 283.Chaney, N. K., 177.Chapman, D. L., 25.Chattaway, F. D., 125.Chick (Miss), H., 191.Christensen, H. R., 223.Christiansen, J., 208.Clarens, J., 52.Clark, R. H., 13.Clarke, H. T., 159.Clemmensen, E., 59.Clibbens, D. A., 162.Clough, G. W., 75.Coade (Miss), M. E., 172.Cohen, E., 10, 12, 33, 34.Coirre, J., 86.Collie, J. N., 28, 38, 40, 284, 285.Colver-Glauert, E., 24, 25.Commessmann, H., 137.Comte, F., 47.Coste, J. H., 167.Cotton, T., 208.Cowell, C. F., 185.Crowther, C., 212.Cruickshank, E. W. H., 201, 202.Cserna, S., 208.Curie (Mme.), M., 278.Cushing, H., 202.Daish, A. J., 186, 232.Dakin, H. D., 192, 193, 197, 200, 201.Damiens, A., 47, 168.Dampier, P., 30.D’Ans.J.. 43.Danysz, J., 280.Darwin, C. G., 239, 241.Davis. W. A.. 186, 232.Dawkn, H. M., 104.3ebye, P., 2, 237.lecker, H., 93, 136.lemomt, D. J., 174.Denham, W. S., 74, 88.DenigBs, G., 169.Denis, W., 196, 199.Denison, R. B., 6.Densch, A., 218, 231.Dewar (Sir), J., 28, 31.Dewey, F. P., 173.Dhar, N., 31.Dieckmann, T., 24, 25.Dimroth O., 22, 122, 123.Dittler, k., 255.Dittrich, M., 165.Dixon, W. E., 210.Dohrn, M., 199.Dolezalek, F., 3, 4.Donau, J., 164.Dormann, E., 157.Douglas; C. E., 208.Douglas, C. G., 208.Drucker. C., 21.Duane, W., -286.Dubom, M., 180.Dudley, H. W., 192, 193, 197, 200.Dudley, W. F., 29.Dunbar. P. B., 180.Dunstan, A.E:, 6.Dupont. G., 66.Dutoit, P., 180.Dux, W., 25.Ebler, E., 277.Edwards, J. D., 179.Egerer, W., 73.Ehrenberg, P., 213, 214.Eisenlohr, F., 96.Eisler. 0.. 195.Eissler, F:, 89.Eitel, W., 165.Elissafoff. G. von, 277.Elod, E.,‘ 47. .Embden. G., 197, 201, 203.Endell, K., ’11. .Ephraim, I?., 36, 37.Erdmann, E., 67.Euwen, C., 10.Evans, G. L., 208.Evans, W. H., 230.Ewald, P. P., 237.Faians. K., 262, 263, 266, 269, 275.Faforiki, A. E., 60.Fedorov, E. S., 245, 246, 248, 252.Feinbertr, M., 136.Feist, K.’, 84.Fej6r, A. von, 202.Feld, W., 172.Ferre, L., 180.Ferrein, F., 136.Fichter, F., 44, 174IKDEX OF AUTHORS' NAMES. 291Findlay, A,, 6.Fischer, E., 77, 78, 83, 84, 85.Fischer, He, 217.Fischer, M , 153, 155, 156, 157, 206Fischer, O., 111, 112.Flack, E., 250.Fleck, A., 262, 266, 268, 272.Fleischer K., J37.Fletcher, A.L. 277.Folin, 0.) 191, '196, 199.Forbes, G. S., 177.Ford, W. E., 261.Foreman, F. W., 198.ForsQn, L., 153, 156.Forster, M. O., 91.Fox, J. J., 95, 96.Frankel, S., 204.Francesconi, L , 117.Francis, F., 162, 163.Frankel, E. M , 201.Frankland, P, F., 70, 75.Fraude, W., 149.Fresenius, L., 219.Freudenberg, I<., 83, 84.Freund, M., 137-Freundlich, H., 19, 22, 277.Friedel, G., 258.Friederici, K., 45.Friedmann, E., 203.Friedrich, W., 234, 236.Friedrichs, F., 37, 48.Fromm, E., 90Fry, H. S., 95.Fry, W. H., 213.Garben, 0. 107.Gardner, J . A., 205, 206.Garknmeister, JX., 177.Gaubert, P., 136.Geake, F.H., 163.Gebhard, K., 95.Geiger, H., 279.Gerhardt, W., 76.Gerlach, M., 231.Gifford, R., 21.Gigon, A,, 202.Gile, P. L., 231.Givens, M, H., 199.Glenk, K., 218.Godlewski, T., 276.Gohring, 0.) 266.Goldschmidt, 8 , 122.Gomberg, M., 113, 114.Goinez, L., 21.Gooch, F. A., 171.Goodey, T., 21'1.Gowing-Scopes, L., 181.Grahmann, W., 256.Grandmougin, IC., 111.Greaves, J. E., 217.Greeff, A., 172,Green, A G., 105; 111, 185.Green, H. I€., 220.Grifiths, E., I, 32.Grifiiths, E. H., 1, 32.Grignard, V , 115.Grimbert, 1, 188.Grob, W., 173.Grun, A., 76.Griinling, 3' , 260.Guareschi, l., 169.Guggenheim, M., 198.Guiterman, K. S., 174.Gully, E., 214.Gutbier, A., 42.Guye, P. A., 31.Guyot, A., 111, 146.Hackspill, T, , 43, 47.Hadfield (Sir), R., 24.Hamalainen, J., 81, 86.Hagmaier, E.W., 176.Hahn, O., 266, 267, 278, 279, 283.Halban, H. von, 22.Haldane, J. S., 208.Hall, A. D., 224.Hall, S. G., 183.Halle, W., lb8.Haller, A., 61.Halliburton, W. D., 210.Hamburger, E., 209.Hamlin, M. L., 228.Hammel, H., 137.Hannemann, K., 209.Hanriot, M., 78.Hantzsch, A , 106, 108.Harries, C. D., 57, 58, 59, 122.Harper, E. M., 159.Hartley, H B., 5.Harvey, A. J., 183.Haschek, E., 277.Haselhoff, E., 229, 231.Hasenbaumer, J., 218.Hasselblatt, M., 11.Hatschek, E., 20.Hauser, O., 68.Hams, E., 111.Haworth, W. N., 117, 118.Heim, F., 184.Heimann, B., 278.Heller, G., 98.Hempel, W., 171.Henderson, G. G., 119.Henderson, J. B., 183.HQrissey, H., 86.Herold, P., 63, 105.Herweg, J., 243.Hess, V.F., 388.Hetper, J., 181.Heuse, W., 29, 31.Heusler, F., 24, 25.Hevesy, G. von, 262, 273, 274.Hewitt, J. T., 106.Hicks, W. M., 265.u 292 INDEX OF AUTHORS’ KAMES.HHHHHHHHHHHHHHHHHHBHHElH€1HHH:ill, A. V., 207.Iilpert, S., 24, 25, 178,Iindhede. 198.:inrichsgn, F. W., 58, 122, 184.:insberg, O., 97, 103.Iintikka, S. V., 121.Iirsch, P., 61.Iobson, F. G., 208.lonigschmid, O., 30, 277.lofmann, K. A., 35.[ogley, C. I?., 276.Iolmberg, B., 71.:olmyard, E. J., 160.:ope, E., 137.Iopwood, A., 82.:ouben, J., 120.luber, M., 135.luberle, R., 19.Iueck, W., 206.lunter, A., 199.lunter, W. H., 179.Iuntly, G.N., 167.lupka, E., 240.:ustin, A., 210.‘utchinson, A., 249.:utchinson, H. B., 216, 217.:ynd, A., 80, 82.Ingraham, D. C., 45.Inouye, K., 10.Iodidi, S. L., 223.Ipatiev, V. N., 65, 66.Irvine, J. C., 79, 80, 82.Ishizaka, N., 19.Ivanov, V. N., 169, 173, 174.Jablczynski, K. , 44.Jacobs, W. A., 167.Jacobson, C., 202.Jannek, J., 29.Janney, N. W., 201.Javillih, M., 230.Johnson, C. M., 176.Johnson (Miss), R. M., 106.Johnson, T. B., 60.Johnston, J., 8.Joly, J., 280.Jonas. L.. 201.Jones;Jones,W: w. J., 18, 99.N., 87.Kailan, A., 287.Kauders, F., 206.Kaufmann. A.. 135. 136.Kautzsch, ‘K. , ‘187. ’Kay, F. W., 136.Kazanskv. D.. 21.Keeble. F.. 87.Kehrmann,’ F., 111.Keller, K., 145.Kenvon. J.. 59. 6%.Kerkovius, ‘B., ‘123.Kindscher, E., 58, 122, 184.King, V.L., 116.Kirschbaum, P., 204.Klemenc, A., 179.Kling, A., 78.Klotz, A., 68.Knipping, P., 234.Kober, P. A., 187.Koenig, A., 47.Konig, J., 186, 210.Konig, W., 146.Kotz, A., 61.Kohnstamm, P., 9.Kolosovski, N. de, 7.Kolowrat, L., 281.Komppa, G., 121.Kopetschni, E., 111.Kossowitsch, P. , 212.Kotake, Y., 83.Kovache, A., 111.lioiniewski, T., 83.Kramer, B., 202.Kraus, C. A., 20.Kremann, R., 75.Kreutz, S., 249.Krieble, V. K., 86.Kroner, J. F., 34.Krogh, A., 198.Krogh, M., 189, 198.Kuenen, J. P., 5.Kuster, W., 157.Kupfer, O., 91.Kurnakov, N. S., 6, 9.Kurrein, H., 73.Kylin, H., 80.Laar, J. J. van, 4.Landau, 206.Lander, P. E., 205.Langheld, K., 187.Lantenois, M., 180.Lapworth, A., 18.62, 99, 204.Larwn, E. S., 255, 259.Lathrop, E. C.. 218.Laudat, M., 188.Laue, M., 234, 235, 237.Lebeau, P., 47, 168.Lee, R. E., 170.Leitmeier, H., 255.Leman, E. D., 279.Lemmel, L., 116.Lemmermann, O., 219.LBn&rd, 206.Lenhardt, S., 103.Lenher, V., 52.Lenzinger, E., 64.Le Sueur, H. R., 92.Leuchs, H., 62. 103.Levallois, F., 186.Levene. P. A., 200, 204, 205,Levy, P., 95, 96.Levy, S. I., 160INDEX OF AUTHORS' NAMES. 293Lewis, T., 208.Liebig, H. von, 95.Lifschutz, I., 188, 206.Limprich, R., 183.Lindemann, F. A., 2, 241.Lingford, H. M., 99.Linnert, K., 204.Lipman, C. B., 220.Lipp, A., 76.Lipp, P., 120.Lippmann, E. 0. von, 80.Litterscheid, I?. M. 182.Locquin, R., 74, 7d.Loeb, A., 203.Lob, W., 93.Lohnis, F., 220.Loewenstein, E., 188.Long, E.R., 199.Long, S. H., 19.Ludlam, E. B., 27.LundBn, H., 17.Lyon, T. L., 221.Macbeth, A. K., 64, 104, 107, 159.McCabe, C . R., 175.McCaughey, W. J., 213.McCleland, N. P., 95.McCoy, H. N., 278, 279.McDavid, J. W., 139.Macdonald, J. L. A., 80.MacIntyre, W. H., 232.McKenzie, A., 70, 75.Madelung, W., 146.Magnus, A., 1.Mahin, E. G., 45.Mailhe, A., 68, 69.Mair, W., 204.Makower, W., 281.Malinowski, S., 137.Rlandelstam, L., 237.Mannich, C., 80, 136.Mansfeld, G. F., 209.Marckwald. W.. 278. , , Marcusson, J., 56.Marquis, R., 184.Marsden. E.. 262. 270. 279.Marsh, J. E:, 161, 248.Marshall, E. K., jun., 188.Marti, W. C., 185.Martin, C. J., 191.Martinet, J., 146.Martyn, G.H., 239, 241.Massini, M., 202.Masson, J. I. O., 41, 285.Mathieu, L., 180.Matignon, C., 44.Maver. A.. 206.Ma$,er; E.; 228.Mayer, P.; 201.Mecklenburg. W., 169, 170.Meerwein, H., 60, 103, 118.Meimberg, E., 175.Meisenheimer, J., 59, 89, 93.Meitner, L., 266, 267, 278, 283.Meldola, R., 106.Mellor, J. W., 175.Menschutkin, B. N., 99.Merck, E., 138.Meston, L. A., 183.Metzener, W., 262.Meyer, A., 20.Meyer, G. M., 196, 200.Meyer, H., 75.Meyer, J., 29.Meyer, K. H., 62, 101, 103, 104.hleyer, R., 107, 111, 112.Meyer, S., 277, 278.Meyer, W. A., 66.Meyeringh, D. J., 94.Michael, A., 63.Milbauer, J., 46.Miller, N. H. J., 212.Miller, P., 76.Mills (Mrs.), AI., 97.Mills, W.H., 97.Mines, G. R., 191.Mochizuki, J., 234.Moesveld, A. L. T., 33.Molisch, H., 287.Montemartini, L., 229.Montgomerie, H. H., 21.Morey, G. W., 257.Morgan, G. T., 106, 129, 131.Morris-Airez, H., 19.Moseley, H. G. J., 239, 241, 273, 278.Moss, H. W., 131.Muller, B., 44.Muller. C.. 7.Muller; X.; 174.>fuller. F.. 209.illurlin, J.'R., 202.Natus, B., 169.Navassart, E., 83.Nees, A. R., 46.Nernst. W.. 2.Neuberg, C:, 200.Key, F., 132.Niggli, P., 257, 258.Noelting, E., 111.Nolan, T. J., 142.Nollv. H. de, 176.Nut;all, J. ~ . , 279.Gbermayer, F., 194.Oddo, B., 145.O d h , S., 19, 215.Ustling, 0. J., 121.Ogilvie, J. P., 182.Ohlon, E., 19.Oldenberg, B., 136.Oldenberg, H., 136.Olivier, S. C. J., 100.Onnes, H.K., 24, 278294 INDEX OF AU'I'HORS' NAMES.Oppenheimer, M., 201.Ost, H., 87, 88.Ostwald. W.. 20.Ott, E.,'70. 'Paitie, H. H., 19.Palache, C., 260.Palozzi, A., 204.Parieth, F., 273, 274, 275Pantenelli, E., 226.Parker, A., 56.Pamas, J , 205.Yassarge, W., 51.Patten, A. J., 185.Patterson, H. S., 28, 38, 40, 284, 285Patterson, S. M7., 201, 202.Patterson, T. S., 21,Pauli, O., 253.Pauli, W., 20.Pnuly, H., 127.Pence, C. M., 181.Perkin, W. H., jun., 116, 117, 118.Petherbridge, F. R., 218.Pfeiffer, P., 112.Pfeiffer, T., 231.Pfutzer, G., 163.Piccard, J., 109.Pickard, R. H., 59, 68.Pictet, A., i36, 137.Pieroni, A., 42.Piest, C., 88.Piloty, O., 61, 157.Pirani, M. von, 2.Plimmer, R. H. A., 187Pohl, R., 234.Pokorny, E., 48.Poma, G., 24.Pope, F.G., 95, 96, 106Pope, W. J., 160.Porter, A. W., 18.Potter, H. M., 16.Power, F. B., 80.Prianischnikov, D., 227.I';ibrain, E., 188.Priess, O., 45.Pringsheim, H., 89.Purvis, J. E., 95, 96.Putnoky, L. von, 262.Pylkov (Mlle.), Z., 49.Pyman, F. L., 93, 139.Quensell, H., 58, 122.Rainer, L. S., 174.Rakshit, J. N., 93.Namsay (Sir), W., 30, 38, 284.Ramstedt, E., 276.R<aschig, F., 49.Read, J., 160.Redman, L. V., 181.Reilly, J., 106, 129.139, 141.Renall, M. H., 205.Hevis, C., 183.Reynolds, J. E., 258.Rhead, T. F. E., 34.Richards, M. B., 22.Richardson, H., 282.Riegel, E. R., 50.Riesenfeld, E. H., 163Ringer, A. I., 201.Ritter, G. A., 218.Ritter, K., 35.Hoaf, H.E., 209.Robinson, R., 137, 139. 141Rocas, M., 229.Rodd, E. H., 250.Rogers, A. F., 260.Rohman, H., 237, 280.Romberg, G. (Breiherr) von, 213.Rosanoff, M. A., 13, 16Rosati, A., 260.Rosenheim, O., 205.Rosicky, V., 260.Ross, A. D., 24, 25.Roth, W. A., 46.Rothenbach, M., 279Rothmund, V.. 171.Rowe, I?. M., 105.Ruff, O., 52.Ruhemann, S., 16C.Rule, A., 43.Rupe, H., 64.Russ, F., 48.RUSS, S., 281.Russell, A. S., 263, 278, 282, 283.Russell, E. J., 216, 218Rutherford, E., 271, 279, 2U0, 282, 283.Ryffel, J. H., 208.Saas, J., 111.Sabatier, P., 68. b9.Salkowski, E., 205.Salway, A. H., 80, 81.Sander, A., 103.Sanger, C. R., 50.Scarpa, G., 24.Schaeffer, Q., 206.Schaller, W. T., 259, 260.Scharf, E., 63.Scheel, K.31.Scheiber, j., 63, 105.Scheuer, O., 286.Scheurer, W., 122.Schlegl, K., 76.Schlenk, W., 113.Schlosser, H., 101Schmidlin, J., 113.Schmidt, H., 188.Schmidt, M., 65.Schmidt, W., 175.Schmitz, E., 77.Schobert, E., 250.Scholl, R. 73, 97fNDEX OF AUTHORS' NAMES.SzBsz, E., 176.Szyszkowski, B. von, 18.Take, E., 24.Tammann, G., 12.Tank, I?., 235.Tanzi, B., 24.Tashiro. S.. 209.295Taylor,'H, ' S., 17.Taylor, T. S., 279.Terada. T . . 238.Scholtz, M , 145, 147, 148, 149.Schreckenbach, R., 146Schreiber, E , 206.Schreiner, O., 218, 228Schreyer, B., 76.Schiirmann, W., 118.Schulov, J., 227.Schultz, R., 75.Schulze, A., 3, 4.Schumpelt, K., 35.Scott. J. P.. 79.bebo< J., 81.Seer, C., 97.Semmler.I?. W., 121-Senden, 'G. H. van 67Senderens, J. B., 89.Senter. G.. 18.sera, Y . , S3.Sernagiotto, E., 117.Seroni, c.,' 204.Severini, G., 226.Shemtschushni, S. F., 6, 9Shipsey (Miss), K., 61.Shorey. E. C., 213.Sibley, R. L., 13.Sidener, C. I?., 176.Sieburp, E., 81.Singh, B. K., 90.Skartvedt, P. M., 176SkertchIy, W. P., 167Skinner, J. J., 228.Skita, A., 66.Smits, A., 10, 11.Slyke, D. D. van, 191, L961Slyke, L. I;. van, 191Smiles, S., 142.Smith, J. L., 204.Smits, A., 21, 34, 257Soddy, F., 263, 267, 268, 271Sommer, F., 48.Stamm, E., 11.Stansbie, J. H., 36.Stark, J., 95, 96, 237.Stark, O., 107.Starling, E H., 201Staudinger, H., 62, 91Steinberger, D., 137.Stern, L., 208.Steuart, D. N., 212.Steudel, H , 199.Stewart, A.W., 64, 104, 107, 159Stewart, J., 213.Stewart, 0. J., 45.Stewart, R., 221.Stock, A., 11, 45.Stoklasa, J., 81, 223, 229Straus, F., 109, 116.Strauss, H., 84.Strube, W., 19.Strutt (Hon.), R. J., 47, 286.Stutzer, A., 232.Sugiura, K., 187.Thalau; W.', 231.Thierfelder, H., 205.Thole, 3'. 13., 6.Thornas, A., 6, 8.Thomas, J. S., 43.'hornson (Siy), J. J , 28, 38, 265, 286.Chorpe, J. F., 71, 72, 73.Chugutt, S., 260.Cichvinski, V. M., 146L'iecie, E., 47.rimmermans, J., 9.Finlcler, C. K., 159.L'raube, W., 50, 51.rreadwell, W. D., 174. 177I'ruthe, W., 89.I'schirch, F. W., 52.Tucker, F H., 176.Turner, T , , 176.rutton, A. E. H., 249.Uhlinger, R. H., 170Ullmann, A. T., 259Umpleby, ,J. B., 259.Underhill, L.K., 25.Underwood, L. M., 224.Urban, J., 232.Uspenski, A. E., 118.Uspenski, N., 238, 241.Valiaschko, N. A, 95.Varvaro, U., 229.Verclon, E., 86.Vereinigte Chininf abriken Zinirrier &Co., 132, 135.Vernon, €I. M., 208VerzLr, F., 202.Viehoever, A., 83.Vielitz, C., 56.Vignon, L., 67.Villiger, V., 111.Viltnorin, P. L. de, 186.Visser, S . W., 5.Vixseboxse. H.. 21.ropp, E., 73.Voylcker, j. A.; 230, 231.VOI t, K., L06.Voimyander, D., 19. 178.Waeker, L., 206.Wagner, E , 236.Walden, P , 17, 21, 2296 lNDEX OF AUTHORS' NAMES,Walker, E. E., 13.Wallasch, H., 46.Walmsley, H. P., 281.Walter, B., 234.Waltzinger, E., 127.Warbury, E., 27.Washburn, E. W., 5.Watson, E. R., 109.Wedekind, E., 24, 132.Wedig, O., 43.Weed, L. H., 202.Weigand, W., 115, 119.Weil, A., 198.Weimer, G., 95.Weishut. F.. 179.Weiss, P., 24.Weissgerber, R., 144.Weith, A. J., 181.Weizmann, C., 82.Werner. E. R.. 61. 92, 125, 172. , I Wesson; L. G.,' 184.West, C. J., 113.West, T., 176.Wheeler, R. V., 34.White, G. F., 6, 8.Whytlaw-Gray, R., 30.Wilkening, L., 87.Willfroth, E., 120.Willheim, R., 194.Williams, G. Y., 5.Willis, L. G., 232.Willstatter, R., 57, 87, 96, 116, 153,Wilson, R. H., 262, 270.\J7inzer, P., 175.Wirth, T., 57.Wituynj, J., 212.Wolesensky, E., 52.Wolf, C. G. L., 208.Wood, A. B., 262.Wood, A. S., 71, 72, 73.'CTroodhouse (Miss), H., 74, 88.Worley, F. P., 13, 14.Wulff, G., 237, 238, 241.Wynne, W. P., 95, 102.Yamnuchi, Y., 35.Zach, K.,. 77, 78.Zambonini, F., 256, 260.Zdohnickj., W., 81.Zechmeister, I,., 87.Zejleis, A., 187.Zeime, A., 109.Zelinski, N. D., 118.Zorn, E., 137.155, 156, 157, 206

ISSN:0365-6217    

DOI:10.1039/AR9131000289

出版商:RSC    

年代:1913

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Acetylene, halogen cl.arivatives of, 56.Acids, organic, 70.Aconitine, 140.Actinium, origin of, 267.Actinium-X, period of, 278.Actinium series, branching of the, 270.Aetiophyllin and Aetioporphorin, 155,Affinity, residual, 159.Agricultural analysis, 185.Alcohols, 59.Aldehydes, 59.Alkali metals, preparation of, 43.phosphides, 47.Alkaloids, 131.Allotropy, 33.dynamic, 10.Alloys, magnetic properties of, 24.action of nitric acid on, 36.Aluminates, 45.Amino-acids, aliphatic, 93.Amino-compounds, aliphatic, 92.Ammelide, 125.Ammines, 36.Ammonification, 219.Ammonium fluorosulphonate, 51.peroxide, preparation of, 43.Analysis of gases, 168.agricultural, 185.electrochemical, 176.inorganic, 169.organic, 178.Anhydrides, organic, 74.Antipyrinediazonium salts, 129.Assimilation of nitrogen compounds,Atmosphere, penetrating radiation ofAtom, structure of the, 270.Atomic weight of radium, 276.Atomic weights, 29.Azobenzenes, amino-, chromoisomerism157.226.the, 280.combined nitrogen in the.211.of, 107.Barium, preparation of, 44.Benzene, structure of, 94.absorption spectrum of, 95.Binary mixtures, theory of, 3.properties of, 7.viscosity of, 5.Bismuth, enantiotropic forms of, 33.Boron, colloidal, 42hydrides, 45.Brevium, 266.Bromination, mechanism of, 63.Bromites, existence of, 52.Cadmium, estimation of, 174.Camphene, constitution of, 118.I-Cana.dine, 139.Caoutchouc, 57, 122.estimation of, 184.Carbamide, mechanism of formationCarbohydrates, 77.Carbon, oxidation of, 34.Carbon subnitride, 127.Carbonates, estimation of, in soils, 232.Carminic acid, 122.Caryophyllenes, 121.Catalysis, 16, 64, 67, 99.negative, 18.Catalytic reduction, 65.Caulophyilosaponin, 80.Caulosaponin, 80.Cellulose, 87.Cerebrosides, 204.Cerebro-spinal fluid.secretion of, 210.Chemical change, effect of pressure on,Chillagite, 259.Chlorine, interaction of hydrogen and,Chlorites, existence of, 52.Chlorophyll group, 151.Cholesterol, 205.of, 92.estimation of, in steel, 176.8.crystallography, 243.25.29295 INDEX OF SUBJECTS.Cl~romo~somerism, 107, 252.Chromous salts, compounds of hydra-zine and, 51.Chrystallography, chemical, 243.Colloids, 18, 41.Colouring matters, 109.Copper, colloidal, 42.estimation of, 173.Cotarnine, synthesis of, 136.Crithmene, 117.Crystals, reflection of s-ra,ys b , 239.Crystal structures, s ray mettocis ofexploring, 234.Custerite, 259.Cyamelide, 125.Cyanuric acid, 125.Delafossite, 260.Denitrification, 219.Diamond, heat of combustion of, 45.Diazo-compounds, aliphatic, 91.Dielectric constants of dissolved salts,Dihydronaphthalenes, 115.Dimethylcyclohexadienes, 117.Dissociation, electrolytic, 20, 22.Dynamic allotropy, 10Electric discharge, 37.Electrical conductivity of fused salts,Electrochemical analysis, 176.Electrolytic dissociation, 20, 22.Elements, isotropic, 263.R a d i o a c t i v eEmulsin, synthesis of glucosides by, 85.Enantiomorphism, 248.Enzyme synthesis, 85.Epidesmine, 260.Equilibrium, influence of the catalystFenchone and isoFenchone, 120.Fluorine, estimation of, 171.Fluorosulphonates, 51.Friedel and Crafts' reaction, 97Gas analysis, 168.Glucinum, preparation of, 44.phosphates, 44.Glucosamine, 82.Glucosides, 80, 82.synthesis of, 85.Glutaconic acids, 71Glycerides, 75.Glycerol, 75.Graphite, heat of combustlon of, 45.Grothine, 260.Haemin, 151, 156.Hrtemoglobin, 206.22.24.radioactive.elements.Seeon, 18.kl wmoporphorin, 158.Halogen compoiinds, 69.Harmaline, constitution oisoHarman, 142.*Harmine, constitution of,Helianbhine, chromoisomeHelium, nroduction of. 35, 141.141ism of, 107.atomic -weight of, 29.ITeterocyclic compounds, o p t i c a Iactivity in, 160.liodqkinsonite, 260.Humic acids, 214.IIydrastinine, synthesis ol, 136.Ilydrazine, preparation of, and itsnitrite, 48.compounds of chromous salts and, 51.Hydroaromatic compounds, 115.Hydrocarbons, 55.Hydrogen, interaction of chlorlne and,phosphides, 47.Hydrolysis, nature of, 13.Hydroxyl ions.determination of, 162.Jndia-rubber See Caoutchouc.1 ndigotin, estimation of, 184.lndole group, the, 144.1 norganic analysis, 169.I somerisni, keto-enolic, 101.Isomorphism, 249.1 sotopic elements, 263.25.Kernies dye, 122.Ketones, 59.preparation cf, 67.Lakes, 111.Lead oxides, 46.Lipoids, 204.Liquids, binary mixtures of, 7.Lycoperdm, 83.effect of pressure on, 9Magnetic properties of alloys, 24.Mancherite, 260.Manures, 229Menthadienes, 116.Menthenols, 116.Metabolism of carbohydrabes and fats,200.of proteins, 191.of purines, 199.Metals, specific heat of, 1.action of nitric acid on, 36.white, analysis of, 174.Metaneon, 265.Methane, synthesis of, 6'1preparation of, 56.tetranitro-, colours with, 159.Methoxyl groups, determination of,178INDEX OF SUBJECTS.299M ethyl-orange, chromoisomerism of,107.Minerals, hydrothermal formation of,257.anhydrothermal syntheses of, 258.new, 259.thermal study of, 254.Moisture, determination of, 166.Morphotropy, 251.Naphthalene, structure of, 94, 96.N aphthat hioxins, 142.Neon, 265.production of, by the electric dis-charge, 37, 2&4.Neutral sait action, 17.Nitric acid, action of, on metals andalloyc, 36.Nitrification, 219.Nitro-compounds, constitution of , 105.Nitrogen, valency of, 89.active modification of, 47.combined, in the atmosphere, 211.compounds, assimilation of, 226.oxides, 48,organic compounds, 89.absorption spectrum of, 96.Nitrosyl chloride, physical constantsof, 49.dicycto-[1, 3, 31-Nonane, synthesis ofderivatives of.118.Nutritions of plants, 224.Optical activity in heterocyclic com-pounds, 160.Organic analysis, 178.Organosols, preparation of, 41.Osmium fluorides, 52.Osmotic pressure, 12.Oxalyl chloride as a synthetic agent,Oxidation, 34.Oxygen, estimation of, in organicOxonides, 63.Palladium, organosol of, 41.detection and estimation of, 175.Pancreatic juice, secretion of, 210.Paraffins, natural, 56.Phosphatides, 204.Photochemical action, new theory of,Photochemistry, 25.Photosynthesis, 81.Phyllins, 155.Physical change, effect of pressure on,Picolide, 149.Plmt nutrition, 224.Plant stimulants, 229.Platinum, organosol of, 41Polymorphism, 10.73.compounds, 178.25.8.Porphorins, 155.Precipitates, minute, treatment of, 163.Pressure, effect of, on physical andProperty-composition curves, 3.Proteins, chemistry and metabolism of,Purine metabolism, 199.Pyrindole, 149.Pyroxmangite, 261.m-Quinonoid conipounds, 107.Radiation, penetrating, of the atmo-sphere, 288.R'adioactive elements, behaviour of, insolution and to solvents, 273.Radioactivit chemical and bio-charnicag'eff ects of, 286.Radium, chemistry of, 276.atomic weight of, 30.ratio of uranium to, 278.Rays, Wntgen, diffraction of, and useof, in exploring crystal structure,234.a - h y s , 275.&Rays, 280.y - h y s , 281.Reduction, catalytic, 65.Respiration, chemistry of, 206.Salts, dissolved, dielectric constantsfused, electrical conductivity of, 24.Selenium, atomic weight of, 29.Silver, colloidal, 42.estimation of, 173.Sodium monosulphide, preparation of,chemical change, 8.191.reflection of, by crystals, 239.of, 22.43.Soils, 212.estimation of carbonates in, 232.SoIids, effect of pressure on, -8.Solubility, effect of pressure on, 10.Solvent, influence of, on velocity ofreaction, 21.Specific heat, 1, 31.Spectra, arc, apparatus for productionof, 163.Steel, estimation of carbon in, 176.S'tick-lac dye, 122.Sucrose, hydrolysis of, 13.hydrolysis of, 10.Sugars, 77.Sulphur, new allotropic form of, 33.Snlphuryl fluoride, 51.Tannin, 83.Tau+omeric compounds, reactivity of,101.Tautomerism, 61, 101,specific heat of, 1.effect of pressure on the rate oftrioxide, reactions of, 50300 ISDEX OF SUBJECTS.Tellurites, metallic, 52.Tellurium, forms of, 34.atomic weight of, 29.Terpenes, 115.Thorium oxide as a catalyst, 68.Thyroid gland, function of the, 209.Tin, estimation of, 174.Triarylmethyi compounds, 113,Tri-indole, 145.Triphenylmethyl, 114.Uranium, ratio of radium to, 278.Uran ium-X 2, 266.Uranium-Y, 267.tJrea, estimation of, 188.Valency, 36.Vanadium, estimation of, 175.Vanadium steel, estimation of phosVapour-pressure curves, 3.Velocity of reaction, influence of theVinylacetylene, synthesis of, 57.Viscosity, measurement of, 5.phorus in, 176.solvent on, 21.Water, estimation of, 164.Weights, atomic.See Atomic weights.I 1-Rays. See Rays, Rontgen.I ' Zinc, estimation of, 174.R. CLAY AND SONS, LTD., BRUWSWICK STREET, STAMFORD STREET, S.E., AND BUNOAY, SUPFOLK

ISSN:0365-6217    

DOI:10.1039/AR9131000297

出版商:RSC    

年代:1913

数据来源: RSC