摘要:

ANNUAL REPORTSON THEPROGRESS OF CHEMISTRYANNUAL REPORTSPROGRESS OF CHEMISTRYF O R 1908.ISSUED BY THE CHEMICAL SOCIETY,Mommifter o f @xblhatirlir :E. C. C. BALY.HORACE T. BROWN, LL. D., F.R. S.A. W. CROSSLEY, D.Sc., Ph.D., F.R.S.WYNDHAM R. DUNSTAN, M.A., F.R.S.M. 0. FORSTER, D.Sc., Ph.D., F.R.S.J. T. HEWITT, M.A., D.Sc., Ph.D.R. MELDOLA, F. R.. S.G. T. MORGAN, D.Se.Sir W. RAMSAP, K. C. B., LL.D., F.R.S.A. SCOTT, M.A., D.Sc., F.R.S.T. E. THORPE, C.B., LL.D., F.R.S.JOHN WADE, D.Sc.@bit or :J. C. CSIS, D.Sc., PbD.Siub- Qbitor :A. J. GREESAWAY.,2Jstrisfatrt S2itrb--@bitur :C. H. DESCH, D.Sc., Ph.D.C. H. DESCH, D.Sc., Ph.D.A. FINDLAY, M.A., D.Sc., Ph.D.A. D. HALL, M.A.W. D. HALLIBURTON, M.D., F.E.S.A. R. LLNG, F.I.C.H. MARSHALL, D.Sc., F.R.S.G.T. MORGAN, D.Sc.W. J. POPE, M.A., M.Sc., F.R.S.Vol. v.L O N D O N :GURNEY L% JACKSON, 10, PATERNOSTER ROW, E.C.1909RICHARD CLAY A N D SONS, LIMITED,BREAD STREET HILL E X . , ANDBUNGAY, SUFFOLKCONTENTS.PAGEGENERAL AND PHYSICAL CHEMISTRY. By dLEXANDER FINDLAT,M.A., D.Sc., PLD. . . . . I . . . . . 1INORGANIC CHEMISTRY. By HUGH MA~LSHALL, D.Sc., F.R.S. . . 3'1ORGANIC CHEMISTRY.T. MORGAX, D.Sc. . . . . . . . . . . 73ANALYTICAL CHEMISTRY. By ARTHUR HOBERT LING, F.I.C. . . 180PHYSIOLOGJCAL CHEMISTRY. By W. D. HALLIBURTON, M.D., F.R.S. 210AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.By A. D. HALL, M.A. . . . . . . . . . 242By CECIL H. DESCH, D.Sc., Ph.D., and GILBEI~TCRYSTALLOGRAPHY. By mrLLLTAM JACKSOX POPE, N.A., M.Sc., F.R.S.25ERRATUM.IN last year’s Report on Analytical Chemistry (Ann. Beport, 1907,215), in referring to an investigation by Cochran, the writer overlookedt h e fact that the effect of acid niercuric nitrate solution on t h epolarisation of lactose had already been studied by J. I3. P. Harrison(Analyst, 1904, 29, 253), who had arrived at precisely the sameconclusionABBREVIATED TITLE.A . . . . . .Aincr. Chew. J. . . .dmer. J. Physiol. . .Amer. J. Sci. . . .Analyst . . . .Annden . ‘. . .Ann. Chi,n. c ~ i ~ n l . . .Ann. C’hiiii. Phys. . .i l ~ n . of Botany. . .Ann. Report . . .Apoth. Zeit. . . .Arch. expt. Path. Phann. .Arch. Hygiene . . .Arch. Pharm. . . .Atti R. Accad. Sci. To.rino.Atti E.Accad. Lineei .Beitr. chew,. P?bysioZ. Path..Ber. . . . . .BeT. Deut. bot. Ges. . .Bied. Zentr. . . .Biochem. Zeitsch. . .Boll. chim. farm. . .Bull. Acad. Xci. Cracow .BzdZ. Coll. Agr. T6LyG .B d l . SOC. chim . .Bull. Soc. chiirt. Belg. .Bull. SOC. franc. Min. .Centr. Bakt. Par. , .Centr. Min. . . .Chem. Zentr. . . .Chem. NGWS . . .chem. Rev. Fdtt-i%6r~-Iiad.Chein. Weekblad . .Chem. Jeit. . . .Com:qt. rend. . . .Gaxzetta . . . .J. Agric. Sci. . . .J. Amer. Chem. Xoc. . .J. Riol. Chem . . .J. Chim.phys. . . .J. Inst. Brewing. . .J. Path. Bad. . . .REFERENCES.TABLE OF ABBREVIATIONS EMPLOYED IN THE* The gear is not inserted in references t o 1908.JOURNAL.Abstracts in Journal of the Chemical Society, *American Chemical Journal.American Journal of Physiology.American Jouimal of Science.The Analyst.Justus Liebig’s Annalen der Chemie.Annales de Chimie analytique appliqne‘e & l’Inclustrie,Annales de Chimie e t de Physique.Annals of Botany.Annual Reports of the Chemical Society.Apotheker Zeitung.Archiv.fiir experimentelle Pathologie uncl Pharinako-Archiv fur Hygiene.Archiv der Phaimazie.Atti della Reale Accademia delle Scienze di Torino.Atti della Reale Accademia dei Lincei.Beitriiqe fiir cheniische Physiologie und Pathologie.Berichte der Deutschen chemischen Gesellschaft.Bericli te der Deutschen botanisdhen Gesellschaft .Biedermann’s Zentralblatt fiir Agrikultnrchemie undBiochemische Zeitschrift.Bollettino chimico farmaceutico.Builetin international de 1’Acadehie des Sciences deBulletin of the College of Agriculture, Imperial Uni-Bulletin de la Soci6t6 chimique de France.Bulletin de la SociBtQ chimique de Relgique.Bulletin de la Socidt6 franqaise de Mindralogie.Centralblatt fur Bakteriologie, Parasitenkunde undCentralblatt fur Minernlogie, .Geologic mid Palaeonto.Chemisches Zentralblatt.Chemical News.Chemische Revue iiber die Fett- und Harz-IndustricChemi scli e Weekblad.Chemiker Zeitung.Comptes rendus hebdomadaires des SEances LIPGazzetta chimica italiana.Journal of Agricultural Science.Journal of the American Chemical Society.Journal of Biological Chemistry, New York.Journal de Chimie physique.Journal of the Institute of Brewing.Journal of Pathology and Bacteriology.li l’Agricnlture, h la Pharmacie e t la Biologie.logie.rationell en Landwirtschafts- Be trieb.Cracovie.versity, T6kyij.Infektionskrankheiten.logie.l’bcaddmie des Sciencesviii TABLE OF ABBREVlATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.J.Pharm. Chim. . .J. Physical Chem. . .J. Physwl. . . .J. pr. Chma. . . .J. Rzcss. Rays. Chem. SOC. .J. SOC. Chem. Ind. . .Landw. Verncehs-Stat. .Mem. Manchestcr Phil. Soe.Metallurgie . . .Min. Mag. . . . .Monatsh. . . . .Mon. Xci. . . . .P$iiger's Arehiz,. . .+harm. J. . . . .Phrm. Rev. . .Pharm. Wcekblad . .Pharm. Zeit. - . .Pham. Zentr-h. . . .Phil. Mag. . . .Phil. Tram. . . .Phpikal. Zeitseh. . .Proc. . . . .Proc. Cantb: Phil.Soe.Proc. IT. Akad. Wetumch:Proe. Physiol. Soc. . .Proc. Boy. Soe. . . .Quart. J. ezp. Physiol. .Rec. trav. chim. . . .Amsterdam.Rev. interm. Xalsv. . .Sci. Proc. Roy. Dubl. SOC. .Sitztcngsber. K. Akad. Wiss.Tech. Quart. . . .Trans. . . . ,Trans. Faraclay SOC. . .Trans. &oy. XOC. Edin. .Zeitsch. anal. Chm. . .Zeitsch. anpw. Chem. .Zeitseh. nnorg. Chenb. . .Zeikch. Chcm. Ind. Kol loide.Zeitsc?t*. Elektrochem. . .Zeitsch. Kryst. Min. . .Zeitsch. Nahr. Genussm. .Berlin.Zcitsclt. tifentl. Chem. .Zeihch. physikal. Chem. .Zcitnch. physiol. Chem.. .Zeitsch. Vcr. dezct. Zuckerind.Zcitsch. wis.. . Photograph.Plwtophysik. Photocli em.JOURNAL.Journal de Pharmacie et de Chimie.Journal of Physical Chemistry.Journal of Physiology.Journal fur praktische Chemie.Journal of the Physical and Chemical Society ofJournal of the Society of Chemical Industry.Die land wirtschaftlichen Versuchs-Stationen.Memoirs and Proceedings of the Manchester LiteraryMetallurgie.Mineralogical Magazine and Journal of the Mineral-Monatshefte fur Chemie und verwandte Theile anrlererMoniteur acientifique.Arcliiv fiir die gesammte Physiologie des Menschennnd tler Thiere.Pharmaceutical Journal.Pharmaceutical Review.Pharmaceutisch Weekblad.Phar mazeu tische Zeitung.Pharmazen tische Zentralhalle.12ussia.and PhiloGophical Society.ogical Society.Wissenschaften.Philosophical Magazine (The London, Edinburgh andPhilosophical Transactions of the Royal Society ofDublin).London.Physikalische Zeitschrift.Proceedings'of the Chemical Society.Proceedings of the Cambridge Philosophical Society.Koninklijke Akademie van Wetenschappen te Amster-dam.Proceedings (English version).Proceedings of the Physiological Society.Proceedings of the Royal Society.Quarterly Journal of experimental Physiology.Receuil des traraux chimiques des Pays-Bas et de laRevue interimtionale des Palsifications.Scientific Proceedings of the Royal Dublin Society.Sitzungsbericlite der Koniglich Preussischen AkademieTechnology Quarterly.Transactions of the Chemical Society.Transactions of the Faraday Society.Transactions of the Royal Society of Edinburgh.Zeitschrift fiir analytische Chemie.Zeitschrift fiir angewandte Chemie.Zeitschrift fur anorganische Chemie.Zeitschrift fiir Chemie mid Industrie der Kolioide.Zeitschrift fiir Elektrochemie.Zeitschrift fiir Krystallographie und Nineralogie.Zeitschrift fiir Untersuchung der Nahrungs- undZei tschrift fiir offentliche Chemie.Zeitschrift fiir physikalische Chemie StochiometrieHoppe-ISeyler's Zeitschrift fur physiologische Chemie.Zeitschrift des Vereins der deutschen Zucker-Zeitschrif't fur wissensehaftliche Photographie,Belgique.der Wissenschaften zu Berlin.Genussmittel.und Verwandtschnftslehre.Industrie.Photophysik und Photochemie

ISSN:0365-6217    

DOI:10.1039/AR90805FP001

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

INORGANIC CBEMISTRY.MANY circumstances make it a matter of considerable difficulty togive within the limits of a Report such as this anything like a fair,general review of the year's progress in the department of InorganicChemistry. The field of investigation to be traversed is so large anddiversified, the ends sought and the methods of working adopted are SOvaried, that it is scarcely possible to group the results into a moderatenumber of general sections, each of which shall form in itself a moreor less consistent whole. I n inorganic chemistry it is comparativelyrare to find what is so common in the organic division, a considerablenumber of independent workers combined in a common attack on awell-defined problem, such as the elucidation of the constitution ofsome prominent group of substances, or the applications of some generalmethod of synthesis.Even when such is the case, as, for example, inthe investigation of the rare earths, the results are often so muchmere matters of detail, or are so restricted in their interest, that anextended discussion of them would scarcely be justifiable.Hitherto the method adopted in this section of the Report hasbeen to review the year's output of work under the individual elements,grouped according to the periodic arrangement; but, whilst it is inthis way possible to touch on most of the important contributions,the result is very apt to be scrappy and disconnected. On the presentoccasion an attempt has been made to approach more to the method ofgrouping referred to above, by which a somewhat more connected kindof treatment is possible. As a consequence, however, it is not possiblein the same space to refer t o so many individual matters, and it isfrequently difficult to make what might be generally approved as afair or judicious selection, so that to many the result may appear ill-balanced and unsatisfactory.The method adopted in former yearshas not been altogether discarded, and a number of more or less dis-connected facts, which might prove interesting in spite of theirisolation, have been included on the same plan as before.Constitution.It is satisfactory to find t h a t the problems regarding the constitu ionof inorganic compounds (or rather, the question of chemical constitiu32 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion in general) are receiving more and more the attention whichthey not only deserve, but require.Even at the present day it is notuncommonly taken for granted that because the compounds dealtwith in organic chemistry are generally much more complex thanthose encountered in inorganic chemistry, therefore the problems ofconstitution are also much more profound; this, however, is not so,the problems in the two cases are different in their nature. I n thecase of organic compounds the tendency to form carbon-carbonlinkings certainly leads to a great multiplicity of substances possessinghigh molecular weight and complicated structure, but even in suchcases the comparatively simple conception of a fixed valency can bemade toaccount for nearly all the observed facts.Carbon forms, forexample, no compouiids of the type M,CX,, although every otherelement in the same group does. I n the study of inorganic chemistry,on the other hand, the ordinary conception of valency proves a brokenreed almost from the beginning, and insistence on it tends only t ohamper progress. The difficulty of giving any generally acceptablerepresentation of the constitution of compounds such asK,O,, KIT, KBF,, etc.,in spite of their apparently simple composition, shows how far we stillare from possessing a workable hypothesis as to the nature of chemicalcombination between elements.Seeing that the next great development of chemical theory may beexpected t o come from the study, not of the compounds of carbon, butof those derived from other elements, it is rather unfortunate that thedifficulties to be overcome are not infrequently slurred over insteadof being boldly faced, and a very large proportion of students maketheir first acquaintance with constitutional problems only in thedomain of organic chemistry.It is somewhat difficult for those whoturn their attention t o the problems of modern inorganic chemistryonly after they have become thoroughly imbued with the spirit oforganic chemistry, to approach the subject with a sufficiently openmind ; indications of the effects of this are apparent in some of thepapers which appear from time to time,During the past year the matter of valency and constitution hasbeen dealt with from the electrochemical point of view in thePresidential Address to the Society,’ and has also been thesubject of several ordinary contributions to the Journal.2 Thesubject is also treated very fully in the latest addition to theseries of “Text-books of Physical Chemistry,” edited by SirW.Ramsay.3 A perusal of this book shows how diverce in someTram., 1908, 93, 774.J. N. Friend, The Theory of Yalcncy.* J. N. Friend, ibid., 260, 1006; H. C. Briggs, ibid., 1564INORGANIC CHEMISTRY. 33respects have been the views propounded from time to time con-cerning the constitution of many of the simplest compounds, andgives an idea of the present somewhat chaotic state of affairs.Even were it only for this reason, the appearance of the work ismatter for congratulation.The Indexing of Inorganic Xubstances.The subject of the nomenclature and classification of inorganic com-pounds is one of great and ever-increasing difficulty, and this has mxdeitself felt very considerably i n connexion with the preparation of ageneral index to the first fifty volumes of the Zeit.schrift f u ranorganische Chemie, in which journal have been published so many ofthe results of recent investigations on complex inorganic substances,A scheme has been adopted which presents many departures fromformer practice, and will doubtless arouse a considerable amount ofinterest, and also of criticism; it is described by A.Rosmheim andJ. Koppel in the preface to the recently-issued index, and also formsthe subject of an appendix to a recent number of the Zeitschrzjl.4 Theauthors point out that, a t first sight, some modification of the methodwhich Richter has so successfully applied to the indexing of organicsubstances might be expected to give equally good results in thisdepartment, but they state reasons why this is not so.For one thing,the chemist who has to establish the identity of some inorganic sub-stance which he has obtained in the course of his work does not., as arule, proceed to make first a complete ultimate analysis of it, butdepends more on the results of qualitative analysis as a guide in hisquest; in preparing an index, thereFore, it is necessary to take intoaccount, not merely the individual elements present in the substsnces,but also the well-mtrked radicles or groups, and an arrangement inwhich exact quantitative composition played an essential part wouldbe of comparatively -slight benefit.To apply Richter’s methodsystematically to inorganic compounds, would practically mean aseparate ‘‘ Lexikon ’’ for each element in turn.The limited space which is here available does not suffice to giveany adequate idea of the scheme as a whole, much less t o discuss i t ;according t o the authors, it is based primarily on : (1) the qualitativecomposition of the s ibstances; (2) the valency of the individualelements ; (3) the electro-a6nity of the individual constituents(elements or radicles) of the compound<. I n order, as far as possible,to prevent allied substances from being separdted by tlie alphabeticorder, the method of printing prefixes, like meta-, pw-, oxy-, etc., initalics and ignoring them in the arrangement is adopted on an exten-4 Ein Yerfahren zur Begistrierunq nnorqnnischer Stofe, 1908, 60, Lfg.3.REP.-VOL. V. 34 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sive scale. For a similar reason, names of Latin origin with termina-tions to indicate degrees of oxidation, etc., are entirely done awaywith, and in their place the ordinary name of the element is used inconjunction with numbers ; thus, magnelic oxide of iron is to be soughtunder Itisen, and would appear as ‘‘ 3-Eisen-4-oxyd.” From thisexample it will be seen that many names become merely paraphrasesof the formulz, and it seems a pity that the Latin names for theelement have not been retained ; for the present purpose, ‘‘ 3-Ferrum-4-oxyd ” would serve equally well, and, by adopting this method, thesymbol of the element might frequently be employed as a contractionwithout affecting the order, and so many of the longer names could beshortened.A system of indexing for general use ought to be based onnames which correspond with a universnlly-adopted set of chemicalsymbols; but then we have not yet reached even this stage. Whetheror not the system adopted for the present index is a success can bedetermined only by experience in actual use, and there has not yetbeen time for such a t e s t ; in any case, i t may be considered an inter-esting experiment, and if it prove a success, or form a starting-pointfor the ultimate achievement of success, it will certainly constitute animportant contribution Lo the progress attained during the pastyear.New Elements.It was mentioned in last year’s Report (p.38) that “ytterbium ”had been shown by Urbain to contain two distinct elements, to whichthe names of Zutecium and neo-ytteinbium had been assigned. A similarconclusion has been reached by von Wel~bach,~ who proposes for theelement with lower atomic weight the name alclebnraniwn (Ad =:172*9), and for the other, cassiopeiunz (Cp= 174.23). Urbain,6 ingiving further particulars regarding his separation, states thatvon Welsbach’s elements are identical with those obtained by himself,and claims priority.7 Whilst the occurrence of a new element in therare-earth group thus seems definitely proved, Urbain has now shownthat, on the other hand, appearances which seemed formerly toindicate the existence of other elements were illusory ; the phospho-rescent spectra of Crookes’ ionium and incogniturn are reproducedby mixtures of salts of gadolinium and terbium, whilst Bayer’sbauxium, from the bauxite of Tar, was a mixture of vanadium andtungsten with traces of other known elements.Monatsh., 1908, 29, 181 ; A ., ii, 591.Compt. rewd., 1908, 146, 406 ; A., ii, 283.7 The International Committee on Atomic weights has given eiiect to this, andCompt. rend., 1907, 145, 1335 ; Bull. SOC. chi?n., 1907, [ivJ, 1, 1158 ; A . , ii,adopted the name Iwtecium (Lu= 174).108INORGANIC CHEMISTRY.35Although the evidence is at present somewhat meagre, i t seemshighly probable that at least one new element has been discovered inthe mineral thorianite. Miss Evans,g in working through the residuesfrom about five hundredweight of the mineral from Ceylon, obtainedindications of the presence of an element giving a brown sulphidesoluble i n ammonium carbonate, but insoluble in hydrochloric acid,and difficult to oxidise by means of potsssium chlorate and hydro-chloric acid. This sulphide was separated, and by treatment withnitric acid a brown oxide was obtained, which was easily reducible bymeans of hydrogen, yielding, first, a black lower oxide, and finally,a dark grey, non-volatile metal. Only about fifty milligrams of thebrown oxide were obtained, ttie yield being less than at the rate of1 gram from a ton of the original mineral.Owing t o the smallquantity available, little could be done in the way of establishing theprecise nature of the substance, but an attempt to determine theapproximate equivalent weight of the element by reduction of theoxide in hydrogen seemed to indicate a value well above that ofarsenic, with which the element may be supposed to present certainanalogies.A preliminary description of several new elements, or compounds ofnew elements, is also given by M. Ogawa,lo who obtained them, notonly from thorianite, but also from molybdenite and reinite. Forone of these he proposes the name nipponium (Np); i t s equivalentweight is about 50 and atomic weight about 100, and it is thereforesuggested t h a t it may occupy a place above manganese, betweenmolybdenum and ruthenium.It forms a basic lower oxide and a nacidic higher one; the first, after ignition, is brown in colour, and thechloride formed from it gives a green solution. A second elementwith an equivalent weight of about 16.7 is also described as givingtwo oxides ; the higher resembles molybdic anhydride, and formssalts of lead, barium, and silver, which are similar t o the molybdatesof these metals. The oxides can be reduced by hydrogen, yieldinga metal which does not fuse at a red heat, which burns brilliantly inair, and is soluble in hydrochloric acid. Whether or not the elementdescribed by Miss Evans corresponds with either of these elements, orperhaps with a mixture of them, i t is difficult to say at present.Ogawa obtained indications of the presence also in thorianite ofa third new element, which yields a radioactive oxide.TTans., 1908, 93, 666.lo J. CoU.Sci. T6kg6, 1908, 25, xv, 1 ; xvi, 1 ; A., ii, 952, 95336 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,Atosnic TJ’eiglht8;.I n this department there has been no very great advance duringthe year. I n the case of the more important elements, there havebeen one or two re-determinations, practically repetitions of formerwork with improved precautions, whilst several workers hare extendedtheir investigations to some of the less prominent elements. Thewhole subject of atomic wei hts is being very fully discussed byBrauner in Abegg’s Hccfidbuch, and in the volume, which appearedduring last year,ll he contributes a general article on ‘‘ fundamental ”atomic weights, namely, those of sodium, potassium, silver, chlorine,bromine, and iodine, using the oxygen standard.By this method ofcollective treatment, instead of the individual treatment adopted forthe other elements, Braune is able to give a much clearer and moreconcise review of these interdependent determinations. He discussesthe results critically, and is not infrequently distinctly a t variancewith the decisions of the International Committee ; his articles arewell worth studying by those interested in this subject. A volume isannounced, which should prove of great value to the same classof reader, and to those specially concerned with analytical chemistry ;this is a collected edition of the results of the atomic weight deter-minations carried out by T.W. Richards and his pupils during thelast twenty-one years. It is being issued in German,’2 and is aresult of the interest aroused by the visit of Professor Richards toBerlin as Exchange ” Professor.The two most important re-determinations during the year are thosefor hydrogen and for chlorine. I n the former case, W. A. Noyes13has renewed experiments on the combining proportions of hydrogenand oxygen in order to test the propriety of, or eliminate the necessityfor, the corrections which he had applied to his previous determina-tions on account of occluded gases, and which brought his value intoclose agreement with that obtained by Morley.The hydrogen wasobtained by olectrolysis, generally from dilute sulphuric acid ;in some experiments it was burned directly, in others itwas first absorbed in palladium; in some it was burnedby means of cupric oxide, in others directly by oxygen (whichwas also prepared electrolytically), using palladium. I n one setof experiments of this latter class, the hydrogen and oxygen wereboth prepared by electrolysis of barium hydroxide solution in place ofdilute sulphuric acid. The results obtained in the different sets of11 Handbzcch d. anorgan. Chemvk, Bd. 11, Abt. 1.12 Expcrimenlnlle Untcrsuchitngcn iil‘w Atonzgezoichte (Voss).13 J. Aqncr. Chem Soc., 1907, 29, 1718 ; A., ii, 100INORGANIC CHEMISTRY.37experiments varied from 1.00771 to 1.00812, m i l give as the probablevalue, 1.00787 ; Noyes, taking:this value in conjunction with that ofMorley (1.00762), consii1ei.s that the mean, 1.00775, would be areasonably trustworthy value.Noyes, along with Weber,l* has also carried out a re-tletermination ofthe Cl/H ratio; the hydrogen was weighed in palladium, passed overweighed potassium platinichloride suitably heated, and the hydrogenchloride produced was collected in water, either directly or, in one setof experirnents, after having first been frozen by means of liquid air.These two sets gave similar results, and in each the two values,HCl/H and Cl/H, were obtainable. The final results give C1= 35.452or C1=35.461, depending on whether the value H=1.00762 orH = 1.00787 (see above) is taken.A set of chlorine determinationshas also been made by Edgar,l5 who burned chlorine in an atmosphereof hydrogen, using silica-ware apparatus, and condensed the hydrogenchloride by means of liquid air ; the mean results of eight experimentswere : for ratio Cl/H, directly 35.194, and from ratio HCl/H, 35,193.For H = 1.00762 these give C1= 35.462 and 35.461. This is in closeagreement with the previous determinations by Dixon and Edgar, andwith Guye’s value deduced from the density.The questions of the homogeneity of tellurium, and of the trueatomic weight of that element, have again been the subject ofinvestigation ; all the recent work goes to confirm the view that thereis not the slightest evidence of lack of homogeneity in the ordinarypurified substance.Marckwald,lG after several hundred systematicfractional crystallisations of 1500 grams of telluric acid, could find nodifference between the first and the last fractions. Lenher17 also,when converting tellurium or its oxide into chloride or double chloride,could find no difference between the element obtained from thecrystallised product and that from the residues, nor could he find anybetween the different specimens obtained by fractional precipitationfrom the tetrachloride by means of ferrous salt. The two observersdo not agree, however, with regard to the atomic weight of theelement. Marckwdd determined the proportion of tellurium dioxideobtained by the regulated heating of telluric acid, specially purified,and carefully dried to constant weight in a vacuum; in this way heobtained the value Te = 126.85, which is very decidedly lower thanthat obtained by Baker,I* namely, 127.60, and is slightly below the14 J.Amer. Chem. SOC., 1908, 30, 13 ; A, ii, 371.15 Nem. Manchester Phil. ii’oc., 1908, 52, No. 7; A., ii, 577.l6 Ber., 1907, 40, 4730 ; A., ii, 33.17 J. Amer. Chm. Soc., 1908, 30, 745 ; A . , ii, 483.l8 Ann. Report, 1907, 3638 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.value for iodine. Lenher, on the okher hand, from the ratio Te : TeO,,obtained the value Te= 127.5, which is in reasonable agreement withBaker's value. I n connexion with Marckwald's low result, it hasbeen pointed out 19 that his method of determination is untrustworthy,owing to the practical impossibility of preparing telluric acid con-taining exactly the quantity of water to correspond with the formulaH,Te0,,2X120.At present, therefore, the balance of evidence seemst o be decidedly in favour of the anomalous positions of iodine andtellurium in the usual periodic arrangement of the elements.A re-determination of the atomic weight of 1ead2O has been madeby the analysis of the chloride prepared by repeated crystallisation inplatinum vessels from solutions containing free acid ; the product didnot discolour on heating, and mas finally fused in an atmosphere ofhydrogen chloride. The proportion of silver, as nitrate, necessary forprecipitation was determined, and also the quantity of silver chlorideformed ; these gave closely concordant results.The mean of thesegives the value P b = 270.190, as compared with the present acceptedvalue, 206.9.Guye's method of calculnting atomic weights from accurate deter-minations of gaseous densities in conjunction with the gas constantshas been applied in the case of hydrogen sulphide21; the result,S = 32.070, thus obtained is an additional indication of the accuracy ofthe method.New determinations of the gaseous densities of krypton andxenon have been made, and from these the values Kr=83*01 andXe= 130.70 are obtained for the atomic weights, assuming the gasest o be monatomic. The former is distinctly higher, and the latterdistinctly lower, than the presently accepted value, but the changesdo not affect the positions of these elements relatively to others.22Other atomic weights re-determined 23 are those of bismuth andpalladium, but these need not be entered upon here; the valuesobtained are not widely different from those in present use.AIEotropy of Elements ; Moleculur Constitution.The relations between the different modifications of elements whichcan exist in more than one form, and the explanations which may beadvanced as to the causes of the wide differences which these oftenl9 Baker, Chew.Arms, 1908, 97, 209 ; A., ii, 483.20 Baxter and Wilson, J . Amer. CAem. Soc., 1908, 30, 187 ; A,, ii, 281.21 Bauine and Yerrot, J. Chinz. Phys., 1908, 6, 610 ; A., ii, 372, 940.22 R.B. Moore, TTCL~S., 1908, 93, 2131.23 Gntbier and Birckenbach, J. pr. Chenz., 1908, [ii], 77, 457; A . , ii, 600.Kemmerer, J. Awzcr. Chern. Li'oc., 1908, 30, 1701 ; A . , ii, 1046INORGANIC CHEMISTRY. 39exhibit, are problems which attract an increasing amount of attention,and there seems to be a growing tendency to refer these differencesto varying degrees of molecular complexity, similar to that so wellknown in the case OF oxygen. As the other elements concerned,however, give only one kind of vapour, evidence as to differencesof molecular complexity is generally wanting, and conjecture insome cases a t least is allowed to take its place.Further investigations into the nature of molten sulphur continueto be made, and, so far, A. Smith’s explanation of the peculiaritiesexhibited by this substance 24 receives at least general c~nfirmation.~~The suggestion is now made by H.Erdmann26 that the formation ofa second distinct liquid phase is due t o a partial splitting up of S,molecules, with formation of S , molecules, The dark variety ofliquid sulphur (Sp) is held to consist of these S, molecules, because itis supposed to be a particularly reactive form of the element, andozone, the particularly reactive form of oxygen, is known to havethe composition 0,. It is even suggested that the name thioxonemight be given to this modification, and that many polysulphidesand organic sulphur derivatives might be looked upon as additiveproducts formed by it, and should therefore be called thioxonidesand polylhioxonides.These assumptions are all made without anyevidence whatsoever as to the molecular weight of S p , and in spiteof the fact that all determinations hitherto made indicate that thesulphur molecule is S , at comparatively low temperatures, butdissociates into 8, molecules when strongly heated, giving noindication of intermediate stages. (From its effect on the freezingpoint of SX, Smith believes that Sp is also composed of S,molecules.)Similarly unfounded assumptions are made regarding variousmodifications of ar~enic.~7 The only molecular-weight determinationsfor this element which have been effected lead to the formulaas4, yet not only is it suggested that various solid modifications ofarsenic must be represented as Ass, As4, As2, and As respectively, butgraphic formulze for the first three are written, with single, double,and treble linkings, and a ring constitution for the first two.Itis assumed that the monatomic molecule must be characteristic ofthe “metailic” variety, for the simple reason that typical metaIsare monatomic; and yet, if chemical evidence counts for any-thing, the ‘‘ metallic ” variety of carbon is presumably highly poly-atomic.24 Ann. Bepod, 1907, 61.2d H. E,. Kruyt, Zeilsch. physiknl. Chcm., 1908, 64, 513 ; A . , ii, 1028.26 Anaalen, 1908, 362, 133 ; A . , ii, 830.37 H. Erdmann, 1-11zncdc?;, 1908, 361, 1 ; A., ii, 55440 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The relations between the different forms of phosphorus naturallyoccupy a prominent position in this section, and cause considerablediscussion.But, whilst there has been a good deal of wordy warfare,little real progress has resulted. Several papers deal with thecommon white and red forms,28 and a number of others with‘‘ Hittorf’s phosphorus,” which is obtaingd in. a crystalline conditionby the prolonged heating of phosphorus with lead. After a con-siderable amount of discussion as to the exact crystalline form ofthis variety of “phosphorus,” it is now stated that the substancemay contain fully half its weight of lead.29 Supposed amorphousforms of other members of this group-antimony and bismuth-whichhad formerly been described .as being produced by heating thecrystallised metals in an atmosphere of nitrogen, are now stated tobe mixtures produced by partial oxidation of the metal, resulting inconsequence of lack of purity in the nitrogen. On the other hand,the supposed crystalline form of ‘(boron,” obtained by a thermitereduction process,3* always contains aluminium, and corresponds withthe formula AlB,, ; apparently, therefore, the preparation of pureboron in a crystallised form is still unaccomplished.Further attempts to induce the transformation of graphite intodiamond, by crystallisation under very high pressures directly applied,have again been quite unsu~cessful.3~The explosive varieties of the platinum metals, obtained by alloyingthe particular metal with a large proportion of zinc and dissolvingthis out from the alloy by means of acid, have now been shownto contain occluded oxygen as well as hydrogen,33 so that theexplosive effect is not to be referred to a sudden allotropic change,but to chemical reaction between the occluded gases.Ruthenium,however, appeared to be exceptional, as this metal was found to beexplosive even when the greatest care was taken to exclude thepossibility of oxygen being present.From time to time attempts have been made to induce in otherelementary gases a polymerisation analogous to the formation ofozone, but without definite result, It had been supposed thatchlorine gave indications of forming a more reactive variety, but itis found that when highly purified chlorine is subjected t o the28 A. Colson, Compt. rend., 1907, 145, 1167 ; 1908, 146, 71, 401 ; A ., ii, 35,176, 273.29 G. E. Linck and P. Moller, Ber., 1908, 41, 1404 ; A , , ii, 48730 E. Cohen and J. Olie, Zeitsch. physikal. Chem., 1908, 61, 586, 696; A.,31 H. Biltz, Bcr., 1908, 41, 2634 ; A., ii, 762.32 R. Tlirelfall, Trans., 1908, 93, 1333.33 E. Coheri and T. Strengers, Zeitsch- physiknt. Chenz., 1908, 61, 698 ; A . ,ii, 299.ii, 198, 199INORGANIC CHEMISTRY. 41influence of the silent electric discharge in an apparatus capable ofindicating a change of volume of 1 in 8000, no appreciable changetakes place ; 34 the increased activity sometimes observed may be due.to the presence of oxygen, which could give rise to the production ofozone or of oxides of chlorine.Alloys.Possibly no branch of inorganic chemistry has during recent yearsmade such rapid strides or accumulated such a mass of new and dis-tinct observations as that which deals with the alloys ‘of the metalsand with those allied substances which for convenience may be in-cluded under the more general heading.One reason for this rapidprogress is doubtless to be found in the technical demand for steels,and similar products, possesing special properties, but perhaps thechief reason has been the great improvement in appliances and pro-cesses (as, for example, in connexion with electrical heating andpyrometry), which have made investigations of this kind more accurate and more suitable for ordinary laboratory work, together with thephysico-chemical developments which facilitate a proper interpretationof the observed phenomena.As is pointed out by G. Charpy 35 ina lecture dealing with the recent progress in connexion with one singlesection of the work, the system Fe-C, investigations in this fieldinclude the following branches : (a) deduction of an equilibriumdiagram by the application of the phase rule, ( 6 ) thermal investiga-tions, (c) isolation of definite compounds from the alloys by chemicalprocesses, (d) microscopic examination, (e) observation of the physicaland chemical properties of the alloys. The discussion of these variousmatters, as given in the lecture, is of general applicability, and mightprove useful to anyone desiring a concise resume of the subject. Cer-tain of these branches are, of course, interesting more particularly tothe physical chemist, the metallurgist, or the engineer, but the isola-tion of definite compounds comes very directly within the scope of theinorganic chemist, and the interest becomes still more pronouncedwhen, as has not infrequently been the case, the systems dealt withare not those of two typical metals, b u t include a metal and a non-metallic or ‘‘ semi-metallic ” element with which distinct compoundsare formed in the ordinary course.From the numerous results ofquite recent work, a few illustrative examples may be selected, moreor less at. hazard.Some pairs of elements, although exhibiting more or less completemiscibility in the liquid state, show no formation of definite compounds34 E. Briner and E. nurand, Zeitsch.Elcktrochem., 1908, 14, 706 ; A . , ii, 940.36 Bull. Soc. ckim., 1908, [iv], 3, 1 ; A . , ii, 69742 ANNUAL REPORTS ON TITE PROGRESS OF CHEMISTRY.and not even of mixed crystals to any noteworthy extent ; an exampleof this is given by the system A1-Si.36 These elements mix com-pletely in all proportions when fused, and the system gives a simplefreezing-point curve of two branches, with eutectic point. I n othercases the complete miscibility extends to the solid state, resulting inthe formation of homogeneous alloys ttiroughout, as in the systemFe-V.S7 I n contrast t o these, some elements which, being closelyallied, might have been expected to form mixed liquids or mixedcrystals, do not do s o ; this is the case with arsenic and bismuth,which exhibit only slight miscibility when fused, and separatecompletely on solidifying.38There are numerous examples ol the formation of ingredients which,from the point of view of chemical composition and otherwise, appearto be definite compounds, even in the case of elements where thiswss hardly to be expected; an interesting example is providedin the system Molten thallium easily dissolves spongyplatinum, and when mixtures which contain an excess of thallium arecooled, the resulting alloy shows a fine eutectic surrounding largercrystals.I f the proportion of platinum is kept below 10 per cent.,these crystals can easily be isolated by means of dilute nitric acid,and, when analysed, they prove to have the composition correspondingwith the formula TIPt.This compound loses part of its thallium onstrong heating, but retains some even a t the temperature of the oxy-hydrogen flame; it displays great similarity to the analogous leadcompound PbPt. Examples of this kind, of which there are many,show that in dealing with alloys the ordinary chemical equivalents(that is, electrochemical equivalents) have no general significance.The isolation of compounds is often a very difficult problem, owicg t othe lack of suitable solvents, which, while attacking the other in-gredients, will not also attack the compound itself. A good exampleOF such a difficulty being successfully overcome is provided by t h eisolation of magnesium silicide, Mg,Si (which is decomposed even bywater), from an alloy rich in magnesium; the excess of metal in thiscase was removed by treatment with a mixture of ethyl iodide andether.40I n the case of ‘‘alloys” derived from elements like sulphur,selenium, phosphorus, etc., which with metals form compounds of theordinary type, the results obtained by the methods under considera-tion are often much less simple than might be expected ; a t the high36 W.Fraenkel, Zeilsch. mtorg. Chem., 1908, 58, I54 ; A . , ii, 592.37 R. Vogel a d G . Tammann, ibid., 73 ; A . , ii, 502.38 K. Friedrich and A. Leroux, Metallz~~gic, 1908, 5, 148 ; A . , ii, 148.39 1,. Hackspill, Cmnpt. rend., 1908, 146, 820; A . , ii, 504.P. Lebeau and R. Bossiiet, ibid.,‘252 ; A., ii, 184INORGANIC CHEMISTRY. 43temperatiires of fusion, known compounds may become unstable andnew compounds be produced, with proportions totally different fromthe others.Thus, the only nickel sulphide that is stable in contactwith the liquid phase of the system NCS is the compound Ni,S, (atatmospheric pressure the maximum amount of sulphur present is31 per cent., owing to volatilisation), but, on cooling, transformations,take place in the solid, and the existence of the three compoundsNiS, Ni3S4, and NiS,, is clearly indicated; there is no Ni,S,although a compound, 2FeS,Ni,S, can be formed when iron ispresent.41A few years ago it was found that certain alloys, although formedfrom non-magnetic elements, w e very distinctly magnetic, and con-siderable attention is now devoted to the observation of this property ;as noted elsewhere, it has now been found that some nitrides, oralloys of nitrides with excess of the metal, are magnetic in a verypronounced degree.A branch of investigation, very closely allied to the study of alloys,deals with the problem of the separation of silicates and similar sub-stances from fused magmas, and a fair amount of work is beingsteadily accomplished in this connexion.The subject is of greatinterest petrologically, from the bearing which it has on the eolutionof problems concerning the formation of igneous rocks, etc. Theszlmegeneral methods are also occasionally used to throw light on otherquestions ; thus it has recently been shown that selenium and iodineform neither compounds nor mixed crystals ; 42 also, that sulphur andiodine form no compounds, and give only one series of mixed crystals,containing only moderate percentages of sulphur. This is a matterof some interest in connexion with the effect of iodine on theequilibrium between SX and S P .~ ~Xeduction of Oxides, etc.The reduction of certain metallic oxides by mere raising of thetemperature is a chemical process to which the student is very earlyintroduced, but until quite recently very little attention was paid tothis matter as a general phenomenon, and i t was only in isolated casesthat the reversibility of oxidation processes and the part played by theoxygen concentration in the surrounding atmosphere were properlytaken into account ; as a rule, also, the cases specially considered fromthis point of view were those in which reduction takes place from a higherI<.Bornemann, illctallwqie, 1908, 5, 13, 61 ; A . , ii, 292.*2 G. Yellini and S. Pedrina, Atti B. Accnd. Lincei, 1908, [v], 17, ii, 78 ; d.,43 F. Ephraim, Zeitsch. a x o y g . C h n . , 1908, 58, 338 ; A., ii, 581.ii, 83344 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to a lower oxide only, the case of mercury being treated as exceptionalwith regard t o the reversibility of the action between metal andoxygen. I n view of a number of recent experimental investigations,however, i t is becoming necessary to deal with the question in a moregeneral and comprehensive manner ; the results obtained show thatmany " stable " oxides: can easily undergo dissociation at not veryhigh temperatures if the other conditions are suitable, that is,provided the pressure or concentration of oxygen be kept sufficientlylow. For example, in the cathode light vacuum,44 cadmium oxideat 1000' dissociates into metal and oxygen, lead oxide does so at 750°,and bismuth oxide a t a still lower temperature; some sulphides alsodissociate, giving sulphur and metal or lower sulphide.For anumberof oxides the dissociation pressures at various temperatures have beenmeasured,45 and where possible also the temperatures have been ascer-tained at which the pressure reaches that of oxygen in the air, thisbeing, of course, the temperature a t which decomposition would setin under ordinary conditions. I n air,cupric oxide would begin to decompose in the neighbourhood of 1025'with formation of oxygen and cuprous oxide; but this is a much morestable compound, for even at that temperature its dissociationpressure is not more than 1 mm.Other determinations of a more orless similar kind have been made by other observers regarding theoxides of chromium (alone, and in presence of copper 0xides),4~1nanganese,~7 iron,4s amd iridium.49I n view of the dissociation phenomena just referred to, themechanism of the reduction of oxides by means of, say, carbon wouldappear to be uncertain; is the oxide directly attacked by the reducingagent, or does this merely act as a kind of absorbent for the oxygenliberated by dissociation ? This problem also has been recentlyinvestigatedy50 and it, would appear that, in many cases at least, carbonacts directly on the oxide ; evolution of gas takes place at tempera-tures f a r below those at which direct dissociation can be detected inabsence of carbon.It has recently been satisfactorily proved that evenmagnesium oxide can be reduced by carbon at a temperature of 1700" ;this had previously been surmised from observed facts,51 but has now44 Damm and Krafft, Ber., 1907, 40, 4775 ; A., ii, 39 ; see also W. von Bolton,45 H. W. Foote and E. K. Smith, J. Amer. Chcm. SOC., 1908, 30, 1344 ; A., ii,46 L. Woliler and P. Wohler, Zeitsch. physikal. Chem., 1908,:62, 440 ; A., ii, 387.47 R. J. Meyer and K. Rotgers, Zee'tsch. anoyg. Chem., 1908, 57, 104 ; A., ii, 191.48 P. T. Walden, J. Amer. Chem.Soc., 1908, 30, 1350 ; A., ii, 852.49 L. Wohler and W. Witzmann, Zeitsch. Elektrochem., 1908, 14,97 ; A . , ii, 301.50 H. C. Greenwood, Trans., 1908, 93, 1483.51 Lebeau, Compt. rend., 1907, 144, 799; A., ii, 1907.One example may be cited :Zeitsch. angew. Chem., 1906, 19, 1537.847INORGANIC CHEMISTRY. 45been demonstrated very conclusively 52 by dissolving the resultingmagnesium vapour in metallic copper (which itself has no action onmagnesia), and, still more conclusively, by condensing it as a metallicmirror on tho walls of an evacuated glass vessel.A study of the rates of reduction of the oxides of lead, cadmium,and bismuth by means of carbon monoxide demonstrates clearlythat lower oxides of these metals exist as definite compounds, a matterwhich formerly wits in some doubt.53 When the results are plotted,breaks in the resulting curves indicate very clearly the formation ofthe compounds Pb,O, Cd,O, and BiO. From results obtained by atotally different method, it appears, further, that these are basicoxides, yielding ions in solutioii; this method consists in showingthat the ordinary salt solutions can dissolve and re-deposit theappropriate metal.It is known, for example, that when copper isbrought into contact with solution of cupric sulphate, an equilibrium,Cu + CuSO, ZZ Cu,S04, is established ; rise of temperature shifts thisquite appreciably towards the right, and a hot solution deposits copperon cooling.54 By arranging a circuln tion apparatus, in which solutionof a suitable salt was brought into contact with metal at a heatedpart and mas then cooled at another, deposits of metal were obtainedin the case of lead, cadmium, bismuth, and thallium.55 These experi-ments, whilst pointing distinctly to the formation of lower salts, giveno evidence as to the composition of these, but it may be taken forgranted that in the first three cases they correspond with the oxidesreferred to above.With regard to thallium, however, the matter isnot so simple; the ion of the thallous salts is Tl', and a lower saltwould therefore involve the assumption of R compound ion, Tl,' ; thiswould present a certain analogy to the anion of the periodides, Is'.The preparation in ihe solid state of halogen compounds derived froma lower oxide of bismuth has actually been effected by the action ofthe metal on the ordinary halides.It is stated56 that in this way adichloride, BiCI,, can be obtained in distinct crystals, which are lessdense than an equivalent mixture of metal and txichloride mould be,and therefore must consist of a true compound ; the analogous bromideand iodide were also obtained. On the other hand, a physico-chemicalstudy of the whole system, bismuth-chlorine, leads to the conclusionthat BiC1, does not exist, but that BiCl and BiC14 do ; 57 on similargrounds, the existence of a bromide, BiBr, is upheld.52 R. E. Slade, Proc., 1907, 23, 152 ; Trans., 1908, 93, 327.6o F. J. Brislee, Trans., 1908, 93, 154.6d Ann. Beport, 1907, 45.55 H. G . Denham and A. J.Allmand, Trans., 1908, 93, 424, 833.s6 W. Hcrz and A. Guttniaiin, Zeitsch. nnorg. Chenz., i908, 56, 422 ; A , , ii, 198,5' B. G. Eggink, Zeitsch. physikal. Chew., 1908, 64, 449 ; A., ii, 104346 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Although they scarcely fall within this section, two other cases ofnew derivatives being obtained may be mentioned here. A loweroxide of titanium, TiO, has been recorded, but analogous derivativeswere practically unknown; the di-iodide, TiI,, which has now beenprepared as a distinctly crystalline substance,5s is the first definiteexample of these. It is obtained by passing the vapour of the tetra-iodide over heated mercury in an atmosphere of hydrogen, and, beingless volatile than the tetra-iodide and mercuric iodide, is easily obtainedseparately from these in the form of black lamella.It is insolublein organic solvents, and is decomposed by water and aqueoussolutions.The other new compounds referred to are a hydrated sesquioxide ofpalladium (which is thus brought more into line with its two neigh-boure, rhodium and ruthenium), and substances derived from it ; 59 inthe meantime, although the stage of oxidation is known, the exactcomposition of the hydroxide itself is not known, and it must be repre-sented by the formula Pd,03,xH,0. It is obtained by electrolyticoxidation of palladous nitrate, and separates as a brown precipitate atthe anode; the temperature must be kept low, and certain otherprecautions observed. The process can easily proceed beyond thedesired stage, not so much by direct oxidation as by the action of acid,giving dioxide and palladous salt.The new oxide dissolves easily inhydrochloric acid, forming a chloride which is unstable; but bysuspending the oxide in ether along with rubidium chloride or caesiumchloride, cooling with solid carbon dioxide and ether, and then passingin hydrogen chloride, crystalline compounds of the compositionN,PdCl, can be prepared. These are decomposed by water, givingderivatives of the lowel- chloride ; no potassium derivative could beobtained.A striking and peculiar phenomenon involving oxidation and reduc-tion has been observed in connexion with certain vanadium compoundsof the alkali metals and of silver.60 When any of these compounds isheated to a high temperature in air and then allowed to cool, it isfound that " spitting " takes place, similar t o what is so well known inthe case of molten silver; here, also, the effect is due to the escape ofoxygen.It has been proved that, at the high temperature, vanadatesare formed corresponding with the general formula M,O,xV,O, (wherex ranges in value from 2 t o 6), but that these, on cooling, change intodmble vanadyl vanadates of various compositions, part of the V,O,becoming V,O, with loss of oxygen ; this oxygen is re-absorbed whenthe vanadyl derivatives are again heated in air.68 E. Defacqz and H. Copaux, Cornpt. rend., 1908, 147, 65 ; A., ii, 699.69 L. Wohler and F. Martin, Zeitsch. anorq. Chm., 1908, 57, 398 ; A., ii, 392.6o W.Prandtl and H. Murchhauser, ibid., 1907, 56, 173 ; A . , ii, 46INORGANIC CHEMISTRY. 47Peroxides, 66 Per-scc Its," etc.The various substances which may be conveniently classed togetherunder the above heading present many points of general interest, andprovide problems for many of which no very satisfactory solution hasbeen propounded. This is reflected in the fairly considerable amountof recent work in connexion with them.One had thought that the constitution to be assigned to themembers of the two groups of higher oxides, commonly designated asperoxides and exemplified by, say, MnO, and BaO,, had been fairlysatisfactorily settled, as expressed by the general formula: M< 0 and0BE<! ; the former are oxides of the ordinary typz, possessing feeblybasic properties (capable of yielding an ion M"") or feebly acidicproperties, or possibly both, whilst the latter are " salts " of hydrogenperoxide.(The expression pel-oxidate seems to be coming into use,and is in many respects convenient.) It is now suggested, homever,61that the two best-known members of the first group, namely MnO,and PbO,, cannot possess a similar constitution, and that the leadcompound should be represented by the formula P b e ? It is rather0'difficult to see what particular character this formula is intended t oexpress; it would seem to indicate a novel kind of peroxidate, butlead dioxide does not yield hydrogen peroxide. The only reasonadduced for assiguing different constitutions is the fact thatmanganese dioxide yields dithionate when treated with sulphurousacid, whilst lead dioxide does not.I n view of the great resemblancesbetween the two oxides, this reason appears totally inadequate, unlessthere is no other way out of the difficulty; one simple explanationwould be to assume that, whilst manganese dioxide forms a normalsulphite, Mn(SO,),, which rearranges to form manganous dithionate,MnS,06, lead dioxide forms a basic sulphite, PbOSO,, which rearrangesto form lead sulphate, PbSO,.The possible existence of a defiuite higher oxide of silver has oftenformed the subject of investigation, and still continues to do so; inlast year's Report (p. 46), facts in favour of assuming an oxide, Ago,yielding a cation, Ag", were discussed.According to the evidenceobtained from electrochemical determinations,G2 it would now appearthat whilst only the oxide, AgO, can be obtained by electrolytic oxida-tion in presence of alkali, with acid electrolyte both this and a stillhigher oxide, Ag,O,, can be produced, each corresponding with aMarino, Zeitsch. a?torg. Chsm., 1907, 56, 233 ; A . , ii, 106.e2 Luther and Pckoriif, ibid., 1908, 57, 290 ; A., ii, 27748 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.definite electrolytic potential. F he establishment of the existence oftwo higher oxides of silver-not peroxidates-is interesting, and bringsthis metal into closer agreement with its neighbours in the first groupof elements, with copper through the oxide Ago, and with goldthrough Ag,O,.This oxide shows a great tendency t o adsorb silversalts, and so gives rise to the various indefinite substances which atdifferent times have been described as silver peroxide. According t oother workers,63 the dark anodic deposit formed during the electrolysisof silver nitrate solution is silver pernitrate, AgNO,, which decom-poses with formation of these indefinite '' peroxides."Reference may here be made to a new oxide of thallium which hasbeen prepared,G4 corresponding in composition with the formula TI0 ;this substance illustrates very well the problems in isomerism whichmay arise even in connexiori with comparatively simple inorganicsubstances. The oxide is obtained a t a low temperature by the actionof hydrogen peroxide on a solution of thallous sulphate andpotassium hydroxide; a red precipitate forms at first, but thisrapidly changes into a bluish-black substance having the above com-position.Three possible views might be held as to the nature ofsuch a mixture. I n view of the known molecular weight of indiumdichloride, MCl,, the existence of a simple oxide, T1:0, is a t first sightnot improbable ; taking into account more1y;the m e h d of preparation,a thallous peroxide, T1,0,, analogous t o sodium peroxide mould seema likely product ; whilst the generally accepted views regarding manythallium compounds with halogens, etc., would point to a thallous-thallic oxide, TI*O*TI:O, as being highly probable. The most generallysatisfactory assumption to make would be 'that thallous peroxidateis produced in the first instance, but rapidly rearranges into thedouble oxide ; this would he analogous t o the change which thallouspersulphate, TI,S,08, undergoes into the isomeric thallous-thallicsulphate, TL'Tl"'(S04),.Further evidence regarding the action of hydrogen peroxide onmercury and the formation of mercury peroxide65 is given by vonAntropoff 66 ; he also comes to the conclusion t h a t HgO, is mercuricperoxidate, and suggesh that probably a still less stable mercurousperoxidate, Hg,Oe, is also formed when hydrogen peroxide and mer-cury interact.The formation and decomposition of hydrogen peroxide itselfcontinue to be invest'igsted.Nernst'a view that its formation inflames is not due to the combustion process, but is merely ttie resultof the exposure of water vapour (with or without free oxygen) to highBaborovskf and Kuzma, Zeitsch.Elektrochmn., 1908, 14, 196 ; A . , ii, 378.84 Rabe, Zeitsch. nnorg. Ch,ern., 1908, 58, 2366 Ann. Report, 1907, 49.A., ii, 498.66 J. pr. Chem,, 1908, [XI, 77, 273 ; A., ii, 383INORGANIC CHEMISTRY. 49temperature, followed by rapid cooling, is confirmed by the observa-tions of F. Fischer and 0. Ringe,G7 who succeeded in showing the forma-tion of peroxide when the heating was effected by meam of ( a ) a Nernstfilament, ( 6 ) a capillary tube of magnesia, heated in a flame, (c) ahydrogen flame directly, (d) electric spark discharge ; this last resultis contrary to Nernst’s statement, and was secured by maintaining agreater velocity of the current of steam and oxygen so as to ensuremore rapid cooling.A patent 68 has been secured for the actual pre-paration of hydrogen peroxide by the method of blowing variousmixtures of steam, hydrogen, and oxygen through flames or othersuitable sources of heat, the velocity being not less than one metreper second; or the source of heat may be caused rapidly to rotate inthe mixture.According to Abe1,Gg the catalysis of hydrogen peroxide by iodine oriodides is due to the occurrence of the two reactions : (1) H,O, + I, =2H’ + 21‘ + 0, and (2) H,O, + 21’ + 2H’ = 2H,O + I,. The first isgreatly accelerated by alkalis, the second by acids, and by maintainingin the solution a suitably small concentration of hydrogen ions(addition of acetic acid and sodium acetate), the two may be made t oproceed at the same rate, so that then the only apparent change is theliberation OF oxygen.The second of Rbel’s equations might be re-presented as ( a ) H,O, + 21’ = 2HO’ + I, and ( b ) 2HO’ + 2H’ = 2H,O ;(1) and ( a ) together, then, represent more clearly the two chief modesof action of hydrogen peroxide, reducing or oxidising, according asdivision of the molecule takes place between the hydrogen and oxygen,or between the oxygen atoms themselves (mldst the alternation ofboth results in apparently simple decomposition). This behaviour cant o a certain extent be compared to that of an ‘‘ amphoteric ” nietallichydroxide, such as that of zinc, towards alkali and acid respectively :O,H HO:K OH HC1ZnO,H H O K and OH H C1’The catalysis of hydrogen peroxide is apparently not influenced bythe concentration of the dissolved oxygen present, a t least when acolloidal solution of a noble metal serves as catalyst; the rate ofdecomposition has been measured under very considerable oxygenand up to as high as 200 atmospheres no difference couldbe found.The formation of ozone (which we may here treat as a peroxide)from oxygen by means of the silent electric discharge can be renderedmore and more complete by lowering the temperature, and it has beenBer., 1908, 41, 945 ; A ., ii, 370.6* D.R.-P. 197023 ; A . , ii, 829.CD Zeitsch. Elcktrochem., 1908, 15, 598 ; A., ii, 939.70 Spear, J. Amer. Chem.. Soc., 1908, 30, 195 ; A., ii, 370.REP.-’VOL.V. 50 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.found possible,71 by maintaining the apparatus a t the temperature ofliquid air (at which temperature the vapour pressure of ozone isexceedingly slight), to convert 99 per cent. of the oxygen into ozone.Even a t this temperature the spark discharge gives less than 1 percent. of ozone, and this small amount may be due really to acmmpany-ing silent discharge.I n last year’s Report (p. 61) mention was made of the preparatiouof a new barium percarbonate, BaCO, ; additional particulars concern-ing this salt have now been published, and also a deecription of thepreparation of a series of related sodium percarbonates.72 The forma-tion and decomposition of the barium salt play a n important part inthe preparation of hydrogen peroxide by the interaction of hydratedbarium peroxide and carbonic acid; if this action is brought about inpresence of a suitable proportion of mater and at a low enoughtemperature, almost no hydrogen peroxide is liberated until morecarbonic anhydride has been passed in than is equivalent to thebarium present, but thereafter the formation is very rapid.Thecarbon dioxide apparently first unites directly with the bariumperoxide, and forms a yellow solid of the composition representedby the above formula, but it has not yet been obtained free fromwater; the compound is not rapidly decomposed by water, nor doeseither alcohol or ether remove hydrogen peroxide from it, so thatit does not seem to be merely an additive compound of the lattersubstance.It is quickly decomposed by acids, including carbonicacid, with formation of hydrogen peroxide. The sodium salts havebeen obtained in a somewhat similar manner from sodium peroxides, inpresenceof a suitable proportion of water and a t low temperatures, byaddition of gaseous or solid carbon dioxide. The peroxides used wereNa20a, Na20,, and NaHO, ; i t is stated that this last can be obtainedin two isomeric forms, namely, NaO*OH and O:Na*OH, the former bythe action of hydrogen peroxide on sodium ethoxide,and the latter, asdescribed by Tafel,73 by the action of absolute alcohol on Na20,. Thesalts obtained, having the composition indicated by the formulae, aredesignated as follows : sodium dioxide carbonate, Na2C0, ; sodium di-oxide bicarbonate, Na,C20, ; sodium trioxide carbonate, Na,C05 ; sodiumtrioxide bicarbonate, NaHCO, (two isomerides, one from each of theisomeric sodium hydrogen dioxides).The names are evidently takenmerely from the name of the oxide used in the preparation ; what theprobable constitution of the compounds is remains to be seen, andBriner and Durancl, Compt. rend., 1907, 145, 1272 ; A , , ii, 101.72 Wolffensteiri and Peltner, Ber., 1908, 41, 275, 280 ; A . , ii, 18@, 183 ; D.R.-P.73 Ber., 1894, 27, 2297 ; A . , 1894, ii, 448.138569, 196369 ; A . , ii, 180, 830INORGANIC CHEMISTRY. 51there must at present be considerable doubt even as to the truecomposition. Substances of so unstable a nature as these are,which cannot be crystallised or otherwise purified, may quite well bemixtures containing carbonate and a percarbonate in various pro-portions ; the substance NaHCO, might be Na,C,O, + H20,, and so on.The assumed existence of two isomeric substances corresponding incomposition with the formula NaHCO, is based merely on observeddifferences in the degree of stability, and this by itself is, of course,not very conclusive evidence; this also constitutes the only evidencefor the existence of isomeric peroxides.No definite indication can begiven as to whether Na2C,0, is the analogue of the potassium saltobtained electrolytically. Possibly the further investigations inwhich the authors are engaged may enable them t o clear up some ofthese points.The preparation of crystalline sodium perborateT4 can be con-veniently effected by first saturating with carbon dioxide a 50 percent.solution of sodium peroxide, adding a sufficiency of a saturatedsolution of sodium metaborate, and then cooling almost to zero.Indications have been obtained of the formation of small quantitiesof perstannates by the electrolysis of concentrated solutions of alkali~ t a n n a t e s , ~ ~ but the compounds are very unstable, and the solutionssoon decompose.I n a paper dealing with columbium and its compounds,76 C. W. Balkeand E. F. Smith describe several new well-crystallised saltsof percolumbicacid, H3Cb0,, which represents one of the most highly oxidised sets ofcompounds known. OF the salts mentioned, the most interesting fromthe theoretical Standpoint are the rubidium and caesium salts,Rb3Cb0, and Cs,CbO, ; being anhydrous, they indicate quite clearlythat the high degree of oxidation of this class of salt cannot bereferred to additive compounds with hydrogen peroxide.I n thepresent state of our knowledge, these substances are most convenientlylooked upon as columbates in which every atom of oxygen has beenreplaced by the peroxide group, -0.0-, an assumption which is inaccord with their mode of preparation by the action of hydrogenperoxide. The salts lose exactly half of their oxygen on ignition, andleave ordinary ortho-columbates.The formation and reactions of the persulphates continue to formthe subject of a considerable amount of original work, and the specialapplicability of the salts t o certain oxidation processes becomesmore and more evident. In some respects, however, there seems tobe misconception regarding the typical mode of action of these55 Coppdoro, Gazzetta, 1908, 38, i, 489 ; A ., ii, 596.76 J, Amer. Chem. ,S’oc., 1908, 30, 1637 ; A., ii, 1043.74 D. R.-T’. 193722 ; A., ii, 689.E 52 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.compounds ; although they are derivatives of hydrogen peroxide(from many points of view, some name, such as paroxydisulphonicacid, indicating this relation more clearly would be preferable topersulphuric acid), they do not in aqueous solution tend so much togive up oxygen directly as to take up metal; that is to say, thestandard mode of decomposition is comparable to the second kind ofaction observable with hydrogen peroxide, as previously noted. Thisis well exemplified by.the action of persulphates on metals, metallichalides, thiosulphates, lower salts of metals which form two basicoxides, etc., and is most conveniently expressed by the use ofionisation formuls ; in all such cases, the action is then merely theassumption of two extra negative charges by S20i', forming2SO,", for example, Zn + S,O, = Zn" + 2SO,", 2Br' + S,O, = Br, +ZSO,)', 2Fe" + S,O," = 2Fe"' + 2S0,".I n one at least of recent paperson the interaction between metals and persulphates,77 there is atendency to look upon the action as being in many cases an indirectone, through co-operation of water.It is true that not infrequentlythe final result is not just the simple one indicated above, but in thesecases the cause is to be sought in subsequent secondary actions.When ammonium persulphate is the salt used, as is generally the case,the possibility of complications occurring is considerably greater thanis the case with the potassium salt. It has been long known thatpersulphate oxidises ammonia and the ammonium radicle withproduction of nitrogen and of nitrate,7* and therefore the action of thepersulphate radicle itself on any particular substance is better observedby using the potassium salt. But even, with this salt, complicationsmay arise, due, for example, to hydrolysis of the primary product; anacid solution may be developed, resulting in hydrolysis of persulphuricacid and formation of hydrogen peroxide, which in its turn may be thesource of the free oxygen which has sometimes been observed.Theextent to which this latter hydrolysis may take place is evidenced bythe fact that in a recent; patent79 this is claimed as a mode ofpreparing hydrogen peroxide, special conditions and precautions, ofcourse, being necessary. I n circumstances where this kind of actiondoes not come into play, however, the reactions into which per-sulphates most readily enter are undoubtedly those which can bereferred to the simple ionic change already mentioned.One or two points concerning sulphur analogues of the class ofy7 M. G. Levi and others, Cazzetta, 1908, 38, 583 ; A. , ii, 581. See also Turrentine,78 See also Levi and Migliorini, Gazxettn, 1908, 38, ii, 10 ; A., ii, 535 ; KenipfJ.Physical Chcm., 1907, 11, 623 ; A . , ii, 104.and Oehler, Ber., 1908, 41, 2576 ; A , , ii, 764.D.R.-P. 199958 ; A . , ii, 1028INORGANIC CHEMISTRY. 53substances dealt with in this section may also conveniently be referredto here.From time to time conflicting statements have been made as to thetrue composition of ‘‘ hydrogen persulphide.” After first havingbeen determined to be somewhat complex, it was later assumed to berepresented by the formula H,S,, from analogy t o hydrogen peroxide ;then various higher sulphides were supposed to exist, correspondingwith the polysulphides of the metals, but this was contradicted byRebs,so who stated that whatever polysulphide might be added to anacid, the resulting hydrogen compounds were H2S and H,S, only.This in turn is now shown to be incorrect, on the authority ofindependent investigators.By fractional distillation (under lowpressure) of the oil obtained by pouring alkali polysulphidesolution into hydrochloric acid, the disulphide, H2S,,81 and the tri-sulphide, H2S3,*2 have been isolated as unstable liquids. The com-position has been exsctly determined by improved methods of analysis(the hydrogen being driven out as hydrogen sulphide, which couldbe accurately estimated), and the molecular weight by cryoscopicmethods. Evidence is also published for the existence of compoundsfrom H,S, to H2S9.83 I n discussing the constitution of these poly-sulphides, Bloch is not unfavourable to Mendelheff’s conception of apossible ‘‘ homologous series ” formed from HSH by successive re-placements of H by SH ; the general formula for such a series wouldof course be S,H,.I n view of various investigations carried out in recent years,it has been suggested that tetrathionic acid has a peroxidic con-stitution, ( H02S,)*O*O*(S202H,), and not the persulphidic constitution,(HO,S)*S*S*(SO,H), generally assumed, the reason being thatalkaline reducing agents apparently abstract oxygen directly from itssalts ; thus, alkaline arsenite solution forms arsenato as well as mono-thioarsenate.It has been shown,s5 however, that there are seriousobjections to the assumption of a peroxide union in the tetrathionates,and that Mendelheff’s persulphide formula, which fits in so well withthe general behaviour of the salts, can perfectly weil account for thesenew facts also.8O Annalen, 1888, 246, 356 ; A., 1888, 1155.81 I.Bloch and F. Hohn, Ber., 1908, 41, 1961, 1975 ; A., ii, 579.83 Eloch and Hohn, ibid., 1971 ; A., ii, 579. R. Schenclc and V. Falcke, ibid.,83 G . Rriini and A.. Borgo, Atti R. Accnd. Liiicei, 1907, [v], 16, ii, 745 ; A . , ii, 102.*4 Ber., 1908, 41, 1980 ; A , , ii, 580.Price and D. F. Twiss, Trans., 1907, 91, 2021 ; J. E. Mackenzie and H.2600 ; A . , ii, 762.Marshall, Trans., 1908, 93, 172654 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Complex salt&Although a short section under the above heading seems in manyways desirable, it is a difficult matter to treat collectively the widelydifferent mbstances which are thus brought together.I n the absenceof general guiding principles, also, any decision as to what are, andwhat are not, included under the term must appear very arbitraryand, in what follows, no attempt is made at any really systematictreatment.I n view of the great development. which certain branches of thesubject have now attained, the appearance of any collective account ofany of these branches is t o be welcomed. During the period under,review the -cobaltammine compounds have thus been treated byP. Pfeiffer,sG and the fact that the description of these substancesextends over 212 large pages gives some idea of the extent to whichthis field has been cultivated.The same author has tabulated thenumerous cases of isomerism which have been observed amongst thecomplex chromium derivatives.s7 A. Colson, who has published manypapers dealing with the green chromic sulphates, has recently given acollected statement of the results obtained by himself.s* A class ofcomplicated compounds which so f a r has not received a great deal ofsystematic investigation is the series of complex acids and saltsderived from molybdenum trioxide and analogous substances ; moreattention is now being devoted to these, and a discussion of their probableconstitution has been published by A. Miolati and R. Pizzighelli.89The polyhalides of the alkali metals may fairly well be calledcomplex salts ; their probable constitution is certainly quite obscure.It is therefore highly desirable that there should be no doubt as towhat members of the group actually exist, and at present the mattercannot be considered as settled.According to the most recent in-vestigation:* the only iodine derivatives of the metals potassium,rubidium, and caejium which can be obtained a t 25’ are : KI,, RbI,,&I,, CsI,, and K17. The compounds, RbI,, Rbl,, Cs17, CsI,,mentioned by Abegg and Hamburger could not be obtained.Complex halogen derivatives of two metals have come in for furtherexamination in the case of several members of the platinum group.I n the case of the iridium compounds, the iridi-salts {M2TrU6) presentno novel characteristics, but the iridio-salts exhibit several features OFinterest from the point of view of Werner’s theory of co-ordinated36 Gmelin-Kraut’s Eandbuch der anorgnnischen Chemie, Bd.V, Abt. 1.87 Zeitsch. nnorg. Chem., 1908, 58, 317 ; A,, ii, 594.83 Ann. Chim. Phys., 1907, [viii], 12, 433 ; A . , ii, 45.89 J. pr. Chem., 1908, [ii], 77, 117 ; A., ii, 595.90 H. W. Foote and W. C. Chalker, Amer. Chcm. J . , 1908, 39, 561 ; A ii. 586INORGANIC CHEMISTRY. 55corn pound^.^^ They can easily be prepared from the iridi-salts byreduction with normal oxalates. The salts are of two types, namely,M,IrC16 and M21rC15, the best example of the former being thesodium salt, Na31rC16,1 2H,O. The corresponding salts of the potassiummetals and of ammonium readily change into those of the other typeby the action of water ; these contain a molecule of water, which is notdriven off at 150°, and are therefore t o be looked upon as aquoiridio-pentaclilorides, M,( H20,Cl51r).The hexachlorides are easily de-hydrated.A number of analogous derivatives of rhodium have been preparedand investigated in connexion with a search for material suitable foruse in determinations of the atomic weight of that element.g2 These“rhodipentachlorides ” 93 also fall into two classes similar to thosementioned above for iridium, and in the second class the molecule ofwater again plays an important part. The corresponding brominecompounds, however, all crystallise in the anhydrous form.I n a series of papers, A. Werner continues the discussion of thepreparation and the constitution of various groups of complex cobalt-ammine compounds.94 Amongst these are a series of violeo-salts ofdichlorotetramminecobalt, [CI,Co( NH3)4] X, stereoisomerides of thepraseo-salts formerly known ; they form intensely blue crystals, andare presumably cis-compounds (1 : %constitution).To the red saltsisolated from Vortmann’s insoluble sulphate (which is a mixture of-NH red and green salts), the constitution Co(NH,),]X,is assigned, the two cobalt atoms being apparently bound throughinactive amino- and hydroxyl groups. The designation “ p-amino- ” isproposed for the former type of union, and the name of octammine-p-amino-ol-dicobalt salts is adopted for these compounds. A consider-able number of them have been prepared. Another series of di-cobaltderivatives has also been elucidated, and is represented by the formula[(NH,),COI(OH),~CO(NH,)~]X~ ; these hexamminetrioldicobalt saltsare isomeric with the dodecamminehexoltetracobalt salts,and are red in colonr.A new set of iodo-salts, obtained by Sand andBokman, has been shown to be the iodopentamminecobalt series,[CoI(NH,),]X, ; these salts are green in colour.[CO(OH)~{CO(~H~>~)3I x699l M. Delepine, Conapt. rend., 1908, 146, 1267 ; A., ii, 702. * A. Gutbier and A. Huttlinger, Ber., 1908, 41, 210 ; A., ii, 200.93 There is room for the adoption of some more systematic nomenclature forsubstances of this kind ; it seems unfortunate that whilst K,IrC15 is potassizsmiridiochloride, K,RhCI is potassium rhodipentachloride.94 Bcr., 1907, 40, 4605, 4817, 4834 ; 1908, 41, 3007 ; also J. Saud and G.Bok.Iiian, ibid., 40, 4497 ; A . , ii, 42, 43, 45, 95056 ANNUAL REPORTS OM THE PROGRESS OF CHEMISTRY.Physiochemical investigations regarding the hydrolysis and themolecular weight of the different chlorides and sulphates of chromium,with a view t o the further elucidation of their constitution, have beencarried out by various cherni~ts.~5 The results do not seem to giveconcordant indications as to the molecular complexity of the green andblue varieties. A green chlorosulphate of chromium,has been prepared, isomeric with that formerly known,[ CrC1,5H20] SO,, 3H20.96As indicated by the formulae, the new salt easily gives C1 ions insolution, but not SO, ions, just the opposite of what is the case withthe other salt.Complex salts, in which iron forms the central constituent, havebeen dealt with by several workers. New pyrophosphate derivativesare described,97 some related to ferric oxide, some to ferrous ; the best-defined of these are the ferric ones of the type M6Fe2(P207)8, andcrystallise with varying proportions of water ; the acid itself has alsobeen isolated.The analogy to the ferricyanides is pointed out (P,O,equivalent to 4CN), and it is proposed to call the salts ferripyro-phosphates ; the ferropyrophosphates, M4Fe2(B207)s, are powerfulreducing agents (see p. 58). Analogous salts derived from metalsother than iron have also been prepared.There has been a good deal of further investigation of the ferro-nitrosulphides (Roussin’s salts) referred t o in last year’s Report(p. 71 Q S ) , in the hope of clearing up their constitution, and severalco-ordination formulae are suggested for the two classes of compounds.When the salts are decomposed in various ways, the nitrogen isobtained in different stages of oxidation-nitrous or nitric oxide,hyponitrite, nitrite-according to the circumstances.99Many of the complex salts derived from molybdenum and tungstencontain twelve atoms of the respective element in the molecule.I nthe paper by Mioletti and Pizzighelli, already mentioned, it issuggested that the acids may all be represented by co-ordinationformulae of the type [R(MO~O~)~]H,, where n is 7 if R represents anelement like phosphorus, and 8 when R is an element like silicon.The formulae stated by various other investigators for substances pre-pared by them do not, however, correspond with acids of this basicity.95 J.Sand and F. Grnmmling, Zcilsch. p7~ysiknl. Chem,., 1908, 62, 1, 28 ; H. G.Denham, Zeitsch. anorg. Chem., 1908, 57, 361 ; A . , ii, 293, 294, 389.96 R. F. Weinland and T. Schumann, Zeitsch. anorg. Chem., 1908, 58, 176 ; A.,ii, 595.98 The formula HFe,(NO)$, is there printed incorrectly.99 L. Caiiibi ; I. Bellucci and P. de Cesaris, Atti R. Acead. Lineei, 1907,[v], 16, ii, 658, 740 ; 1908, [v], 17, i, 202, 424, 5 4 5 ; A . , ii, 41, 111, 388,499, 593.[ CrS0,,5H20]C1,97 P. Pascal, Compt. rend., 1908, 146, 231 ; A . , ii, 193INORGANIC CHEMISTRY. 57Mercuric cyanide reacts with a number of other mercuric salts (forexample, the perchlorate) to form complex derivatives ; from a physico-chemical study of the properties of the solutions of these compounds,lproof is obtained that the mercury in them forms part of a complexunivalent cation, (HgCN)'.A number of the salts have beenprepared in the crystalline condition ; their dilute solutions give noprecipitate on the addition of sodium hydroxide. Even the compoundof mercuric cyanide with mercuric oxide appears t o be the basic oxide,(HgCN),O, and t o give a hydroxide, (HgCN)OH, when it dissolves inwater. Similar complex cations apparently are formed from mercuricperchlorate and mercuric iodide, bromide, and chloride, the tendencyto form them decreasing in the order given, Crystalline compoundsare obtainable in the first and second case, but not in the last; thesecompounds are decomposed by treatment with water.Colloids.During recent years much interesting work has been done in con-nexion with colloids generally, and a considerabIe proportion of thenew developments have to deal with the inorganic branch of the sub-ject.Many of the papers which have appeared in the course of thepast year fall rather within the domain of physical chemistry, butothers of a more descriptive character may be referred to here.Colloidal sulphur has already been prepared by the method of usingelectrical discharges ; it is now shown that it can also be obtainedfrom the sulphur which separates when sodium thiosulphate solutionis added to cold concentrated sulphuric acid.The liquid is somewhatdiluted, heated, filtered through glass wool, and allowed to cool ; theseprocesses are repeated so long as any sulphur, which will notredissolve, is precipitated. A cloudy, yellowish-coloured mass is t, husobtained, which, on warming, forms a liquid, which is apparentlyperfectly clear ; it separates again on cooling. This mass is separatedas completely as possible by means of a centrifuge, and is partlywashed in a similar manner, after which the remaining acid is neutral-ised with sodium carbonate. The product is soluble in water, but ifthe attempt is made to remove the sodium sulphate from the hydrosolby dialysis, insoluble sulphur is very soon deposited.Dilute solutions,in which the sulphuric acid has not been neutralised, can be preservedfor a long time, but the hydrosol very easily precipitates insolublesulphur on addition of various salts.The preparation of a more or less colloidal form of graphite, speciallysuitable for lubricating purposes, has been effected by prolonged1 V. Borelli, Gnzzetta, 1908, 38, i, 261 ; ii, 421 ; A., i, 515 ; ii, 1039.2 M. Raffo, Zcitsch. Chem. Ind. Kolloide, 1908, 2, 358 ; A . , ii, 68358 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.agitation of the graphite with a solution of tannic acid ; 3 the materialthus obtained passes through filters and remains in suspension formonths, but it becomes flocculated on the addition of hydrochloricacid. The method of preparation was based on the known action oftannic acid and other substances on china-clay, by which the latter isrendered much more workable for certain pottery purposes; afluid “slip,” suitable for casting in forms, can by such means beprepared with much less water than formerly had to be used.Convenient reducing agents for the preparation of colloidal metalsand some other reduction products are found to be provided by theferropyrophosphates of the alkali metals *-salts which can be easilyprepared in solution by adding a solution of ferrous salt to a solutionof an ordinary alkali pyrophosphate.(Solutions of these and similarcomplex pyrophosphates are useful also in connexion with the electro-deposition of certain metals for purposes of quantitative analysis,)The colloidal solutions of gold and silver obtained in this way are ofa very intense colour, and.it is stated that the reaction may be used asa colorimetric method of estimating these metals.Strange to say,platinum compounds give no result with this reagent, but cupric andmercuric salts can be reduced first to the lower stage of oxidation andthen to colloidal metals. The colloidal cuprous hydroxide, which canbe obtained in this way, appears yellow by reflected light, and is saidto provide avery sensitive reaction in testing for trsces of copper.I n the state of colloidal solution, palladium still exhibits theproperty of absorbing hydrogen,5 forming a hydrosol of the ‘‘ hydride ” ;and in this state its power of absorption is much greater than is thecase when it is in the form of palladium black This absorbs, at most,somewhat less than nine hundred times its volume of the gas, but thecolloidal form takes up from nine hundred to nearly three thousandtimes its volume.(No explanation can be given for the great fluctua-tions of the value found in different experiments.) The colloidalhydride reacts rapidly with any free or loosely-combined oxygen whichmay be present, and the numbers given have been corrected for thehydrogen used up in this way.The bearing which colloidal silver and siIver compounds have inrelation t o photographic images, and to the photo-chemistry of silvergenerally, is discussed in a series of papcrs by Luppo-Cramer ; 6 heconsiders that the ‘( sub-halides ” of silver are not definite compounds,but adsorption products, and that the different appearances of the3 E.G. Acheson, J . Franklin I n s t . , 1907, 164, 375 ; A., ii, 375.4 P. Pascal, Compt. rend., 1908, 146, 862; A . , ii, 500.6 Zcitsch. Chem. Ind. Xolloide, 1907, 2, 135 ; 1908, 2, 360; 3, 33, 135 ; A,, ii,C. Paal and J. Gerum, Ber., 1908, 41, 805 ; A . , ii, 392.378, 691, 841, 945INORGANIC CHEMISTRY. 59silver images obtained with different developers are due to the more orless colloidal state of the silver and the different substances adsorbedby it from the developer. (The other view receives favourable con-sideration from T r i ~ e l l i , ~ who gives a full discussion of both theories.)A specially interesting development in the study of colloids recentlyhas been the preparation in colloidal form of a number of what wereformerly considered the very antitheses of such substances-thetypical I‘ crystalloid ” salts, such as the halides of the alkali metals ;organosols of these can be obtained by the interaction of suitablecompounds, such as ethyl ethylsodiomalonate and ethyl chloroacetate,8dissolved in anhydrous ether, benzene, etc.Similar results have alsabeen obtained with a number of salts of magnesium and the metals ofthe alkaline earths ; it appears more and more likely, therefore, thatsnbstances generally may be obtained in the colloidal form if only theycan be produced by interactions in solvents in which the solubility ofthe ordinary form of the product is sufficiently slight.Colloidalbarium sulphate can be obtained by double decomposition in glycerolsolutions of the reacting salts; the hydrosol thus obtained isparticularly stable in presence of barium nitrate, although salts ofmost other metals precipitate it ; it is also coagulated by polybasic acids,but not by monobasic. A newly-devised general method for obtainingcolloidal salts of the metals of the alkalis and the alkaline earthsconsists in actiug with the appropriate acid on tho thiocyanate of themetal, each substance being dissolved in a mixture of ether and amylalcohol.1° A number of colloidal salts of magnesium and the metals ofthe alkaline earths can also be prepared by the interaction o€ theappropriate acid on the basic oxide of the metal, dissolved in methylalcohol.11I n general, the various salts prepared by these methods can beprecipitated, as gels, by the addition of suitable liquids, and re-dissolvedin the colloidal form, by means of others which act as appropriate‘ 6 solvents.”Some interesting experiments which had for their aim the prepara-tion of gelatinous aluminium silicates, of definite composition, by theinteraction of sodium silicate and aluminium acetate, gave entirelynegative results ; 12 from their behaviour towards solvents, etc., theprecipitates obtained in this may appear to be merely mechanical7 Zeitsch. wiss.Photograph. Photophysik. Photochem., 1908, 6, 358 ; A . , ii, 1036.e C. Pad and G. Kiihn, Bey., 1908, 41, 51, 58 ; A., ii, 179.9 A.Recoura, Compt. re?&., 1908,146, 1274 ; A., ii, 692.10 P. P. von Weimarn, Zeitsch. Chem. I n d . Kolloide, 1908, 3, 89 ; A., ii, 842.11 C. Ncuberg and B. Rewald, Sitzungsber. K. A k a d . Wiss. Berlin, 1907, 820 jA , , ii, 39 ; Biochem. Zeitsch., 1908, 9, 537 ; A., ii, 495.12 H. Stremme, Ccdr, Mix,, 1908, 622, 661 ; A , , ii, 104160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.mixtures of hydrated alumina and hydrated silica. This observation,taken in conjunction with the widely variable composition of thenatural non-crystalline and clay-like substances known as halloysite,aliophane, etc., leads to the conclusion that these are not definitecompounds, but variable mixtures.:Bure Earths.As in forrher years, there has again been a considerable amount ofinvestigation carried out in connexion with this complicated group ofsubstances, but there is not much %,f it that calls for special commentin a geyeral rQsum6; the most noteworthy result, the separation ofytterbium into two components, has already been mentioned (p.34).The search for improved means of fractionation, of course, continues,and several new or modified processes are suggested. Amongst thesalts recommended for the purpose are the brornates ; l3 starting fromthe oxalates, they are obtained by treatment with sulphuric acid,followed by double decomposition with barium bromate. Other com-pounds which have proved serviceable for certain groups of elementsare the malonates, obtained directly from the hydroxides by the actionof malonic acid, and the l-naphthol-8-~ulphonates,~~ obtained From thecarbonates by the action of the sulphonic acid; the solubilities ofmany of the salts of these acids have been definitely measured.A considerable number of new compounds of the rare-earth metalshave been prepared and described, but generally they exhibit nostriking or exceptional characters.Several sulphides have beenexamined,15 and some of these have been found to give a distinct odourof hydrogen persulphide when acted on by hydrochloric acid; it istherefore suggested that, say, cerium disulphide is not a simpleS sulphide, Ce<<$, but a persulphide, and might be written Ce,S,S.Several substances, partly oxide and partly sulphide, have also beenobtained.The Argon Group.The most interesting contribution to our knowledge of this class ofelements which has been made during the year has undoubtedly beenthe liquefaction of helium by Onnes,lG regarding which a communica-tion was also made to the Chemistry Section of the British Associationat Dublin by Sir James Dewar.Premature announcements of success13 C. James, Chent. News, 1908, 97, 61, 205 ; A . , ii, 190, 498.14 H. Erdmann and F. Wirth, AmKden, 19OS, 361, 190 ; A., i, 621 ; ii, 694.15 A. Duboin, Compt. refid., 1908, 146, 815 ; A., ii, 502 ; W. Biltz, Ber., 1908,16 Proc. K. Akad. Welemch. Amsterdam, 1908, 10, 744 ; 11, 168 ; d., ii, 490,41, 3341 ; A., ii, 1037.944INORGANIC CHEMISTRY. 61had been made, but it was found that the results on which thesewere based had been obtained with impure material, and that onemilligram of- hydrogen, diffused through a space of 7 c.c., broughtabout peculiar phenomena in the highly compressed and cooledhelium, which had caused it to be assumed that liquefaction of thiselement had taken place.For the thorough purification of the material-two hundred litres ofhelium were used for the final condensation-Dewar's method of absorp-tion in charcoal at low temperatures was employed in conjunctionwith the usual chemical methods for eliminating active elements.Preliminary study of the isotherms for helium at the temperaturesproducible by liquid hydrogen had shown that the Joule-Kelvin effectwould probably be sufficient to secure condensation, so that the Linde-Hampson method of working should prove successful, and theapparatus by which the result was actually obtained was similar tothat used for the liquefaction of hydrogen.Considerable quantitiesof liquid air and hydrogen for auxiliary cooling were prepared before-hand, and three hours' work on the helium sufficed to produce fully60 C.C. of colourless, transparent liquid, having a density of only 0.15.It boils at 4 . 5 O Abs., which is within one degree of its critical point ;attempts to freeze it by rapid evaporation under diminished pressurewere unsuccessful, although the temperature reached mas probablyabout 3' Abs.Attempts have been made t o obtain compounds of argon by meansof arc and spark discharges in liquid argon, using electrodes of variousmetals, but without S U C C ~ S S .~ ~ A polymerisation of the element couldnot be expected from a monatomic gas (the formation of ozone bysimilar processes presumably depends on the preliminary rupture of thediatomic molecule). Apparently there is no tendency to form evenunstable compounds with the material of the electrodes ; suchcompounds, if formed at the temperature of the discharge, mightpossibly become fixed by the very rapid cooling.Most of the other work of the year deals almost entirely with thenatural occurrence of the various gases, and with unsuccessful attemptst o discover other members of the group. It would now appear to befairly certain that no other gases are present in the atmosphere i nappreciable quantity; the residues from about 120 tons of liquid airhave been subjected to a searching examination,lS but no indications ofany unknown element could be obtained ; other experiments have alsogiven negative results.It has been suggested by Sir WilliamRamsay that the emanation from the radioactive elements mayrepresent the higher members of this group.l7 F. Fischer and G . Iliovici, Bcr., 1908, 41, 3802 ; A . , ii, 1034.R. B. Moore, €'.roc. Roy. Soc., 1908, 81, A, 195; A . , ii, 84062 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Some very striking figures regarding the total quantity of noble gasesevolved from certain thermal springs are given by C. Moureu and R.Biquard ; l9 according to their results, one spring, the Bourbon-Lancy,must evolve in the course of a year fully sixteen thousand litres ofnoble gases, of which quantity no less than ten thousand litres consistof helium.All the waters of these springs are radioactive, a point ofconsiderable interest in connexion with the production of helium fromradium emanation.Group I.As was mentioned in last year's Report (p. 47), calcium hydridehas been suggested as a convenient and portable material for use inthe preparation of hydrogen, which is obtaiDed merely by the actionof water on it; a competitor now appears in the form of aluminiumfilings which have been treated with small quantities of potassiumcyanide and mercuric chloride.20 The hydrogen is obtained by droppingwater on the prepared metal, and the action takes place rapidly if thesupply of water is so regulated as to permit of the temperature beingmaintained a t 70" by the heat evolved in the action.One gram givesabout 1.3 litres of gas at the ordinary temperature, as compared withabout 1 litre in the case of calcium hydride.21The possible utilisation of natural silicates as sources of potassiumcompounds on the large scale has been investigated ; although potash-felspar when finely divided may be decomposed by water or aqueoussolutions of various salts, the methods so far tried do not promise t obe sufficiently economical to be practicable.22 Leucite, which is alsoricher in potassium, can be fairly easily decomposed by sulphuric acidor nitric acid, and various processes for separating potassium saltsfrom the solutions thus prepared are sugge~ted.~3The relative solubilities of metallic silver in molten lead and zinc,which are so widely different that the desilverisation of lead by zinc(Parkes' process) is the best method known, have been determined atvarious concentrations.24 At 500° the partition coefficient Zn : P b isabout 300 : 1.I n Parkes' process the separation is effected a t amuch lower temperature than this, the zinc being allowed to solidify,and under these conditions this r,ttio is increased greatly in favour ofthe zinc.l9 Compt. rend., 1908, 146, 435 ; A . , ii, 277.2o Nauricheau-Beauprd, ibid., 1908, 147, 310 ; A., ii, 829.21 I n last year's Report, the vo1ume:of hydrogen stated is only one-tenth of the2a A. S. Cushman and P. Hubbard, J.Amcr. Chem. Soc., 1908, 30, 779 ; A., ii,* C. Manuelli, Qamettn, 1908, 38, i, 143 ; A . , ii, 386.24 G. N. Potdar, J. Coll. Sci. T6ky6, 1908, 25, ix, 1 ; A . , ii, 945.correct amount.586IN ORG A N IC C HEM ISTRY. 63Finelg-divided gold is energetically attacked by fused sodiumperoxide, with formation of sodium aurate, and from this salt, bymeans of dilute sulphuric acid, auric acid, H3Au03, or, more probably,HAuO,,H,O, can be obtained. To prepare auFates satisfactorily fromthe acid, it should be treated with the pure appropriate hydroxide inan atmosphere free from carbon dioxide, and the resulting solutionshould then be evaporated in the dark.25The properties of metallic calcium and its capabilities as a chemicalreagent continue t o receive a fair amount of attentioo, and severalpapers dealing with various reactions in which it takes part haverecently appeared.These include an investigation of its action onammonia alid on amino-derivatives under various conditions ; 26 it isparticularly reactive with arylamines, producing compounds of thetype (NHR),Ca. Further information regmding the use of the metaland its hydride as reducing agents in " thermite '' processes has alsobeen published ; 27 reactions with the hydride are less violent thanwith the free metal.Within the last fern years an extensive series of investigations hasbeen carried out on the compounds formed by union of calciumsulphate and other metallic sulphatey, and a considerable numberof new salts have been obtained; during the year this work hasbeen continued, and additional double and triple sulphates, suchas Rb,Ca,(SO,), and K,Ca~Cd(SO,),,2H2O, have been prepared.28When water of crystallisation is not taken into account, salts ofthis kind are easily enough represented by ordinary constitutionalformula Anhydrous calcium sulphate (the mineral anhydrits) isfrequently treated as being isomorphous with the sulphates ofstrontium, barium, and lead; like them it forms rhombic crystals,but its axial ratios differ considerably from those of the othersulphates; it is now shown fairly conclusively that it is not iso-morphous with these.The varions salts have been preparedartificially in crystals of moderate size by deposition from solutionin hot concentrated sulphuric acid, and it is found that calciumsulphate does not form mixed crystals with the others, mhicb,however, form mixed crystals among themsel~es.~~25 F.Meyer, Compt. rend., 1907, 145, 805 ; A., ii, 47.26 H. Erdmann and H. van der Smissen, AnnaEen, 1908, 361 32 ; A., ii, 587.27 F. M. Perkin and L. Pratt, [l'mns. Farnday Soc., 1908, 3, 179 ; A, ii, 379.2* J. D'Ans, BcT., 1907, 40, 4912 ; 1908, 41, 187, 1776, 1777 ; A . , ii, 104, 182,890.P. Gaubeit, Cwnpt. I-cud., l?07, 145, 877 ; A., ii, 3864 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It would appear that bicarbonates of this group of metals can reallyexist in the solid state, although they are exceedingly unstable;30thus, when ammonium or potassium bicarbonate solution is added toa solution of calcium chloride, both being cooled to zero, a white,crystalline precipitate is obtained, the composition of which ap-proximates t o that expressed by the formula Ca( LICO,),.An interesting description is given of the working up of theresidues from 30,000 kilograms of pitchblende residues for radium.31The operations extended over two years, and the total radium con-tained in the products was equivalent t o rather more than 3 grams ofradium chloride.A final fraction of radium bromide was found tolose bromine on keeping. An atomic weight determination on thechloride gave the value Ra = 225.Group 111.There has been comparatively little work done in connexion withthis group, beyond that dealing with ‘‘ thermite ” reactions and thepreparation of alloy-like derivatives of boron and silicon.Indiumselenate has been prepared, and i t s ability t o form alums demonstratedby the isolation of the cEsium salt, CsIn(SO4),,12H,O, in octahedralcrystals .32 A number of crystallised complex silico-tungstates con-taining indium have also been described, analogous to similarcompounds formed by aluminium, iron, chromium, etc.33Group IV.The absorption of carbon monoxide by solutions of cuprous chlorideand other salts has been investigated on somewhat similar lines tothose referred t o in last year’s Report (p. 57) with regard t o nitricoxide and varius metallic salts.34 The proportion of gas absorbednever exceeds the ratio CO : Cu, and in all kinds of aqueous solutionsa definite compound, CnC1,C0,2H2O, is formed with the chloride.No absorptiov takes place except in the presence of water, ammonia,aniline, or other substance capable of forming additive compoundslike t h a t above formulated.I n addition to a fair amount of work on the preparation of silicidesand silicon alloys, and on ‘‘ thermite ” processes involving silicon,30 E.H. Keiser and others, J. Amer. Chem. Soc:., 1908, 30, 1711, 1714 ; A., ii,1036, 1037.L. Haitinger and K. Ulrich, Monatsh., 1908, 29, 486 ; A., ii, 857.32 F. C. Mathers and C. G. Schluederberg, J. Ainer Chem. Xoc., 1908, 30, 211 ;93 G. N. Wyrouboff, BUZZ. SOC. franc. MZ’?L., 1907, 3 , 277 ; A., ii, 386.34 W. Manchot and J. N. Friend, Annalen, 1908, 359, 100; A., ii, 375.A ., ii, 386INORGANIC CHEMISTRY. 65there has been a good deal of investigation as to the formation ofsilicic acids and soluble silicates. As a result, there appears to bevery considerable doubi; as to the existence of any definite hydrate ofsilica what~oever.3~ From a determination of the amount of hydrogenevolved when certain silicides and titanides are decomposed by suchagents as hydrofluoric acid, sulphuric acid, or potassium hydroxide,W. Manchot 36 seeks to show that in compounds of that class siliconand titanium form chains, but the evidence does not seem t o justifythe construction of constitutional formulae for such substances.Pure zirconium fluoride, which can beeeasily prepared by the actionof dry hydrogen fluoride on zirconium chloride, forms a snow-white,crystalline powder, which, as regards chemical character, is sur-prisingly inerL37 It is sparingly soluble in water, and does notundergo hydrolysis, but can be re-precipitated as a hydrate,ZrF,,3H20.Group KA very large amount of work in connexion with the members ofthis group has recently appeared.A considerable proportion of theinterest centres around problems connected with the technicalutilisation of atmospheric nitrogen, either by oxidation to nitriteand nitrate or by reduction to ammonia.A number of metallic nitrides have been studied, their preparationbeing effected by heating the metals in an atmosphere either ofnitrogen 38 or of arnm0nia.3~ The temperatures at which metals absorbnitrogen vary greatly in different cases : with magnesium, calcinm,aluminium, and chromium the process begins at about 800°, but withiron, copper, and some others no action occurs below 1250’.I n thefirst three cases, definite compounds are formed, namely, Mg,N2,Ca3N2, and AlN; in the other cases the proportion of nitrogenabsorbed is not sufficient t o form compounds of this “ammoniatype,” and it is doubtful whether the resulting substance is not ofthe nature of a solid so1ution;of nitrogen or metallic nitride, in themetal. An interesting character of several of these products is thatthey are magnetic; in some (chromium and titanium) this property isdistinctly noticeable, and in the case of manganese (12 per cent.nitrogen) it is almost as intense as in the case of iron.It variesgreatly with the composition, however, and attains a maximum0. Miigge, Centr. Mi?&,, 1908,-129 ; J. M. van Eemmelen, Zeitsch. anorg. Chem.,1908, 59, 225 ; H. Le Chatelier, Compt. rend., 1908, 147, 660; A., ii, 277, 838,1033.Annalen, 1907, 357, 129, 140 ; A., ii, 40, 46.I. I. Shukoff> J. Xuss. Phys. Chem. Soc., 1908, 40, 457; A., ii, 484.37 L. Wolter, Chem. Zeit., 1908, 32, 606 ; A., ii, 701.39 G. G. Henderson and J. C. Galletly, J. Soc. Chem. Ind., 1908, 27, 387 ; A,,ii, 485.REP.-VOL. V. 66 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.according to other observers 40 at a composition which would correspondwith the formula MnpN,. When metals are heated in ammoniainstead of nitrogen, the results obtained are somewhat similar; incases where no distinct fixation of nitrogen takes place (for example,tin), there is nevertheless a considerable change in the physicalcondition of the metal, and a considerable proportion of the ammoniaundergoes decomposition into its elements.The formation of definite compounds when metals dissolve in liquidammonia, assumed by Moissan and others, is denied by Kraus41 so faras lithium, sodium, and potassium are concerned, but confirmed in thecase of calcium; the compound is not represented by the formulaCa(NK,),, however, as given by Moissan, but by Ca(NH,),.The direct formation of hydrazine from ammonia can be broughtabout, with a good yield, by means of sodium hyp~chlorite,~~ pro-vided the viscosity of the solution has been increased by the additionof a small quantity of some suitable organic substance, such as glue.The further condensation of hydrazine to azoimide (hydrazoic acid)by means of oxidising agents is well known ; oxidation by means ofnitric acid forms a simple lecture experiment.A quantitative studyof the behaviour of several allied oxidising agents under certainconditions has disclosed several peculiar results.43 In presence ofsulphuric acid, potassium chlorate gives a large yield of azoimide,bromate gives much less, and iodate gives none at all ; in presence ofsilver sulphate, as well as sulphuric acid, all three give about the sameyield (averaging about 12 per cent.), which is, however, much lessthan that obtained with chlorate in absence of silver (more than22 per cent.).The actions with the halogens themselves also exhibitpeculiarities. A convenient method for the actual preparation ofazoimide is suggested 44 in the interaction of ethyl nitrite and hydrazinesalts under certain conditions; thus, a yield of more than 80 per cent.can be obtained by shaking the ester for six hours with an aqueoussolution of hydrazine sulphate and sodium hydroxide.Ebler and Schott publish a long paper 45 dealing with hydroxylamineand its derivatives, in which they give a full discussion of its probableconstitution; they accept the view that it is tautomeric, towardsalkalis acting as a weak acid, NH,*OH, and with acids acting as aH weak base, NH,:O, forming oxonium salts, NH,:O<X. Certain4u E. Wedekind and T, Veit, Ber., 1908, 41, 3769 ; A., ii, 1041.41 J.Amer. Chem. Soc., 1908, 30, 653 ; A . , ii, 486.J2 F. Raschig, D.R.-P. 198307 ; A., ii, 1029.43 A. W. Browne and F. F. Shetterly, J. Amer. Chem. Soc., 1908, 30, 53 ; A.,44 J. Thiele, Ber., 1908, 41, 2681 ; A., ii, 940.45 J. pr. Chem., 1908, [ii], 78, 289 ; A., ii, 1029.ii, 373INORGANIC CHEMISTRY. 67metals, such as zinc and calcium, can displace hydrogen from itdirectly, forming more or less unstable hydroxykbmcctes, for example,Cit(O*NH,). It is also stated that hydroxylamine reacts likehydrogen peroxide with titanium solutions, giving the same yellowcolour.I n connexion with the oxides of nitrogen, much of the recentwork bears on the synthetic production of these substances at hightemperatures, attained elec trically or otherwise ; a considerable pro-portion of t,his deals with the various equilibria which are establishedduring the formation of the oxides 40 or during their absorption by waterand ~olutions,~7 and cannot be entered upon here.Under suitableconditions, oxidation of the nitrogen may proceed as far as nitricanhydride (for example, nitrogen peroxide is rapidly oxidised into thisby ozone), and in such a case synthetic nitric acid of high concen-tration may be prepared directly. The direct production of purenitrites is another problem of great technical importance, and it isclaimed that this result can be attaiaed by oxidising atmosphericnitrogen to the appropriate extent in the electric arc, and main-taining the gases at a temperature not below 300' until absorptionin solution of alkali hydroxide has been effected; in this way theformation of higher oxides is almost entirely prevented.48 Theanalysis of mixtures of nitrogen oxides can be effected by examina-tion of their ultra-red absorption spectra ; 49 all five oxides, and alsoozone, can be detected by their different maxima OF absorption.I nthis may the nature of the products obtained under various conditionsof electrical discharge, etc., can be conveniently examined.Some interesting observations on the glowing of phosphorus andsome of its compounds have been described. The glowing of phos-phorous anhydride when mixed with oxygen has been investigated byS~harff,~o who finds that it is influenced by temperature, oxygen-concentration, presence of other substances, etc., in very much thesame way as is the glowing of phosphorus itself ; to a certain extentthis is also the case with the glowing of the sulphide P,S,.Theseresults seem to point to the conclusion that the phosphorescenceassociated with the slow oxidation of phosphorus is due, not t o theprimary oxidation of the element, but to the subsequent oxidation ofthe phosphorous anhydride so produced. This view seems to be sup-46 E. H. Keiser and L. McMaster, Anzer. Chenz. J., 1908,39, 101 ; A., ii, 223. 3'.Haber and A. Koenig, Zcitsch. Elektrochem., 1907,13, 725 ; 14, 689 ; A., ii, 34, 940.47 F. Foerster and M. Koch, Zeitsch. angew. Chew,., 1908, 21, 2161, 2209 ; A , ,ii, 941, 1031.a Radische Anilin- & Soda-Fabrik, D.R.-P. 188185 ; A., ii, 175.49 E.Warburg and G. LeithSuser, Sitzzengsjer. K. Akad. Whs. Berlin, 1908, 148 ;80 Zeitsch. physikal. Chem., 1908, 62, 179 ; A., ii, 373.A., ii, 175.F 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ported by a striking phenomenon observed by L. and E. Bloch 51 duringan investigation of the ionisation effects which are produced when airis passed over phosphorus. They found that if the speed of the aircurrent is increased, then the phosphorescence is drawn out in thedirection of the current, and, on further increasing the speed, itbecomes completely detached from the phosphorus ; with a suflicientlylong tube and suitably regulated current, a steady phosphorescentcolumn may be obtained, separated from the phosphorus by a darkregion several metres in length.I n this dark space there is neitherproduction of ozone nor ionisation, so that all three phenomena aredirectly connected. It is possible, of course, that the phosphorescenceis due to phosphorus vapour which is carried forward, but moreprobably it is due to vapour of the oxide.Several corrections of what are said to be erroneoug statementsregarding phosphorus compounds may be noted. Only three definitesulphides of phosphorus exist,’namely, P,S,, P,S,, and P2S5,52 other so-called sulphides being merely mixtures. The various ‘< polyphoe-phates ” are merely mixtures of pyrophosphate and metaphosphate.53Hypophosphoric acid corresponds with the simple formula H,PO,, asis shown by the molecular weights of its esters,54 determined ebullio-scopically on solutions in alkyl iodides.A number of papers dealing with the subject of arsine have recentlyappeared, and yield a considerable amount of detailed informationregarding its decomposition by heat,b5 its behaviour with solutions ofvarious metallic salts,56 and its oxidation.57 With silver nitrate solu-tion there is a certain amount of precipitation of silver arsenide,Ag3As, and not of metallic silver alone, as is frequently stated ; withammoniacal nitrate solution, arsenide is also precipitated, but under-goes oxidation with formation both of arsenite and arsenate, anddeposition of silver.A n interesting method of purifying, say, concentrated sulphuric acidfrom arsenic compounds has been patented ; 58 i t consists in convertingthe arsenic into chloride or‘ fluoride by addition of the appropriateacid, and then extracting with benzene, which completely removes thearsenious halide ; the benzene in turn can be purified by agitation withwater. Dichlorobenzene acts in the same way, and can be applied inb1 Compl. rend., 1908, 147, 842; A ., ii, 1032.52 A. Stock, Ber., 1908, 41, 558, 657 ; A . , ii, 274.53 N. Parravano and G. Calcagni, Atti $. Accud. Lincei, 1908, [v], 17, i, 731 ;54 A, Rosenheim and M. Pritze, Ber., 1908, 41, 2708 ; A., ii, 942.55 A. Stock and others, Ber., 41, 1319 ; A., ii, 488.56 H. Reckl9ben and others, Zeitsch. anal. Chetn., 1907, 46, 671 ; A . , ii, 36.57 H. Reckleben, ibid., 1908, 47, 105 ; A ., ii, 176.58 Chemische Fabrik Griesheim-Elektron, D.R.-P. 194864 ; A., ii, 686.A., ii, 838INORGANIC CHEMISTRY. 69connexion with a scrubbing process for gases contaminated witharsenic ; in such cases its lower volatility is an advantage.The rarer members of this group:have recently received a consider-able share of attention, .and a large number of new compounds ofthem are described, many..of them being of a complex kind. Theyinclude derivatives of so-called hypovanadic acid, V2O,,2H,O,59 whichin these compounds exhibits basic functions ; whilst most of its deriv-atives are more or less decidedly blue in colour, the double nitritesare colourless or yellow, so that complex derivatives are evidentlyformed by it.I n Balko and Smith's paper already mentioned (p. 51),various columbates, fluoro-columbates, and percolumbates are described,along with analogous tantalum compounds; many have a complexcomposition. The columbium material used by them, as well as thatsimilarly obtained from many different sources, was subjected torigorous spectroscopic examination,60 and it is shown that pure colum-'bium solutions, quite free from titanium, give a yellow coloration onapplication of the hydrogen peroxide test, so that the presence ofcolumbium vitiates this as a reaction for titanium.Group TI.The elucidation of the reactions involved in the contact processfor the manufacture of sulphuric acid, mlien metallic oxides are used ascatalysts, has given rise to a considerable amount of investigation,and, in particular, the equilibrium conditions in the dissociation ofthe sulphates of iron and of a good many other metals has been veryfully studied.61 Some of the results obtained indicate that the catalyticaction of ferric oxide is not due to alternate reduction and oxidation,since sulphur dioxide by itself is without effect at the temperaturesinvolved; nor is the action due to the union of ferric oxide, sulphurdioxide, and oxygen, forming a ferric sulphste, since the concentrationof sulphur trioxide at a given temperature is higher than whatis produced by dissociation of ferric sulphate.The action would there-fore appear to consist in the direct union of sulphur dioxide andoxygen, induced by some sort of condensation effect at the surface ofthe catalyst.The dehydration of the ordinary crystallised thiosalphates is amatter of some difficulty, which formerly gave rise to divergent view.59 Ann.Report, 1907, 59 ; G. Gain, Cumpt. rend., 1907, 146, 403 ; Ann. Chim.Phys., 1908, [viii], 14, 224; A . , ii, 284, 599.TV. M. Barr, J. Amer. Chern. Soc., 1908, 30, 1668; J. H. Hildebrand, ibid.,1662 ; A!., ii, 1045.61 G. Keppeler and others, Zeitsch. physikd Chem., 1908, 62, 89 ; Zeitsch. nngew.Chem., 1908, 21, 532, 537 ; L. Wijhler and others, Ber., 1908, 41, 703 ; Zeitsch.physikal. Chem., 19OS, 62, 641 ; A,, ii, 289, 290, 482, 58170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.regarding the constitution of these salts ; apparently, however, thedirect preparation of the anhydrous salts is comparatively simple.Bypassing hydrogen sulphide over powdered sodium sulphide at 3003, drysodium hydrosulphide is obtained, and from this the thiosulphate canbe obtained by the action of air or oxygen at 100-150°.62Most of the important work on chromium deals with the complexsalts and similar substances derived from it. The complications andisomerism apparently extend to the hydroxides ; the pure substance of'' Guignet's green " is a hydroxide, Cr,O,(OH),, which has the samecomposition as the greyish-violet hydroxide, but, whilst the formerexbibits distinct vapour pressures of 13-26 mm. at temperaturesbetween 7 5 O and S4", the latter has practically none.63G~oup VII.There is little of moment to be noted here in connexion with thehalogens; several papers have been published which deal with thedetails of electrolytic processes of preparation on the large scale, andcall for no comment.One technical matter of general interest may,however, be referred to, namely, the preparation of dry calciumhypochlorite.64 According to one process, this can be effected byacting on milk of lime with chlorine, evaporating the clear solution a ta low temperature under diminished pressure so as to crystallise outthe hypochlorite as quickly as possible, and dehydrating the crystal-lised salt, also under diminished pressure. An improvement consistsin adding fresh quantities of lime and chlorine alternately, after thefirst chlorination, by which means it is possible to obtain a good yieldof hypochlorite without evaporation.It is claimed that the dried saltis not deliquescent, and keeps well. It is, of course, much moreefficient than bleaching powder, and, on treatment with hydrochloricacid, it gives nearly its own weight of chlorine. A substance of thiskind should prove of considerable use in laboratory work.The propriety of placing manganese in the seventh group ofelements has been questioned,@' on account of its almost complete lackof relationship with the halogens, and its great similarity to membersof the eighth group. The difficulty is analogous to that which resultswhen copper, silver, and gold are classed along with the alkali metals,and shows that Mendeldeff's original arrangement is not altogether ahappy one ; although the arrangement may occasionally serve for arough classification (as in the present case), its use nowadays is hardly62 D.R.-P. 194881, 194882 ; A., ii, 689.'63 L. W'Viihler and W. Becker, Zeitsch. nngew. Chcm., 1908, 21, 1600 ; A., ii, 765.(i3 D.R.-P. 188524, 195896; A., ii, 280, 692.65 H. Reynolds, Chcna. News, 1907, 96, 260 ; A., ii, 41INORGANIC CHEMISTRY. 71justifiable.avoided by the use of longer periods.66Many difficulties, such as those mentioned above, can beGroup VIII.Interest in the metals of this group centres largely in the complexsalts formed by the various members, and in the alloys and similarsubstances of which they form constituents; in both these depart-ments there has been considerable activity during the year.The rusting of iron seems to provide a never-ending problem, anddifferent investigators continue to draw diff erent conclusions as theresult of their researches ; several additional papers have recentlyappeared.67 Two different problems are really involved in thediscussion : one the behaviour of pure iron in presence of pure waterand oxygen, and the other the behaviour of the different kinds ofiron and its alloys in ordinary use. Owing to the great difficulty ofgetting reasonably homogeneous samples of pure iron (slight differ-ences of composition may produce pronounced differences in theelectrical conditions, etc.), the first problem is one regarding whichit is very difficult to obtain a satisfactory decision, and it is one ofrelatively slight practical importance. The other, however, is amatter of the very greatest practical importance, and necessitates astudy of the effects which variations in composition and in theattendant circumstances produce on the rate of rusting underordinary conditions; the second of the papers to which reference hasbeen made is an extensive investigation of this kind.There is further evidence that platinum, when used as an anode incertain electrolytic processes, or otherwise submitted t o the action ofpowerful oxidising agents, is not quite so resistant as is generallyassumed,6s so that the possibility of traces of platinum passing intosolution in this way should not be overlooked. I n consequence ofthe highly refractory qualities of iridium and rhodium, these metalsseem to be almost ideal materials (except as regards price) for theproduction OF crucibles and other apparatus.69 '' Boiling aqua regia,fused microcosmic salt, or other phosphates with frequent additions ofcarbon, strongly heated silica or silicates with a reducing agent, boil-ing lead at a white heat, boiling zinc, and molten nickel, iron, orti6 See, for example, J. Walker, Introduction to Physical Chemistry ; A. Werner,Neucre Anscharcungen a?$ dem Gebietc der aizorganischen Chemie.67 J. N. Friend, J. I r o n and Steel Inst., 1908, 77, i, 5 ; E. Heyn and 0. Bauer,Mitt. k. i!lat.-pruf.-Aint., Gi.oss-Liziiterfeldc, 1907, 26, 1 ; -4., ii, 698, 849 ; W. A.Tilden, Trans., 1908, 93, 1356.6y Awn. Report, 1907, 73 ; C . Marie, Coinpt. rewd., 1908, 146, 475 ; R. Ruer,Zeitsch. EZektroche?iz., 1908, 14, 309, 633 ; A . , ii, 299, 601, 954.6g Sir W. Crookes, PYOC. Boy. SOC., 1908, 80, A, 535 ; A . , ii, 70272 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.gold, are without effect on the crucible, which, after cleaning, retainsits weight unchanged ” ; it is also passive under many other forms ofchemical torture.A very full investigation of the preparation and properties of theoxides of iridium has been carried out.70 No monoxide, IrO, could beobtained, although such has been said to exist; the sesquioxide,Ir203, and the trioxide, Ir03, could not be prepared in a pure con-dition; the dioxide, Ir02, however, was obtained practically pure as asolid, and also in colloidal solution. When heated, the sesquioxidedecomposes into dioxide and metal, some oxygen also being evolved.HUGH MARSHALL.7O L. Wohler and W. Witzmann, Zeitsch. anorg. Chem., 1908, 57, 323; A., ii300

ISSN:0365-6217    

DOI:10.1039/AR9080500031

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.THE present report embraces the subject matter of four separatereports i n previous annual volumes, dealing respectively withaliphatic, homocyclic, and heterocyclic compounds, and with stereo-chemistry. A glance at3 the Abstracts for the year 1908 will showthat the space allotted to summaries of organic research is equal to thatdevoted t o the rhumbs of all other sections of chemical activity. Itis therefore inevitable that references to many valuable reseaches havebeen omitted, for only by making a selection of the year’s output inorganic chemistry has it been found possible to keep this reportwithin reasonable bounds.The theoretical views implied in the conventional structuralformuh have held their own with remarkable success throughout thedevelopment of organic chemistry, but their insufficiency to expressthe whole of the facts is becoming more obvious every year, and greatuncertainty still prevails as to the nature of the changes to be madein order to bring certain of these formulae into closer accordance withthe experimental evidence.There can be little doubt that ideasderived from the consideration of plane formulae require to be con-stantly verified by reference to the steric relationships of thecomponent parts of the molecule of organic compounds. I n certaincases the uncertainty or ambiguity attaching t o the use of staticconjugations has led t o the adoption of dynamic formule. Thedirect application of such a physical hypothesis as that of the electronto organic chemistry would seem to be premature, probably becausethe hypothesis is still imperfectly developed, even in its simplerapplications t o the question of chemical affinity, but it has alreadyfurnished several suggestive qualitative ideas.The recent developments in the bheory of chemical valency impliedin such conceptions as those of principal and subsidiary valencies andco-ordinated compounds have been adopted only in very few instances.Many of this year’s researches have an important bearing on the valencyof oxygen, and afford ample confirmatory evidence as t o the quadri-valent nature of this element, particularly as manifested in the cyclicoxonium salts.On the other hand, no definite conclusion has bee74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.reached in regard to the assumed tervalency of carbon in triphenyl-methyl.A striking feature-of the year's work is the number of investiga-tions dealing directly or indirectly with the influence of unsaturation,especially of the nature and arrangement of double linkings.Theideas put forward by Thiele, in 1899, recur frequently in recent work,notably those of partial valency and of the conjugation of doublelinkings. The first will be discussed below in connexion with thequestion of colour and fluorescence; the second finds an importantplace in many discussions as to the origin of colour and the reactivityof tautomeric compounds.The Mechccnism of Reactions.The great advances made in recent years in our knowledge of thestructure of organic compounds have directed attention all the morevividly t o the gaps which remain. This is especially the case withregard to reactions.The chemical equation only represents, as a rule,the initial and final stages, the mechanism by which the resultis obtained remaining obscure, and only to be filled by the assumptionof hypothetical intermediate products, the nature of which it is oftenvery difficult to define. Much recent work has been directed to theelucidation of the mechanism of familiar reactions, such as thecatalytic hydrogenation and dehydrogenation of organic compounds bymetals, the reactions depending on the employment of magnesiumorganic compounds, the condensations in presence of aluminiumchloride and of sodium ethoxide, and the formation of esters, etc.Catalytic Action of Metals and Inorganic Substances.The remarkable results achieved by Sabatier and Senderens on thehydrogenation of organic compounds in the presence of finely-dividednickel at moderately high temperatures have led to numerousresearches on the influence of catalysts in the synthesis and decom-position of organic substances.Many aromatic compounds have been converted by the Sabatier andSenderens' method into the corresponding hydroaromatic derivatives.With hydrogen a t 200' in the presence of nickel, p-benzoquinone andits homologues are reduced quantitatively to quinols. A t 220-250' thequinols are decomposed into the corresponding phenols, and water isliberated, but a t lower temperatures the qninols undergo furtherhydrogenation, becoming converted into cyclohexane-1 : 4-diols.Quinol itself a t 160-170' gives a mixture of phenol, cyclohexanolORGANIC CHEMISTRY.75and cis- and trccns-cyclohexane-1 : 4-diols ; at 130' this cis-modificationis formed exclusively.Catechol under similar conditions gives cis-cyclohexane-1 : 2-diolexclusively, resorcinol does not yield definite products, but pyrogallolis reduced to cyclohexane-1 : 2 : 3-triol.1Other unsaturated rings may be hydrogenated by this method.yH,*CH,CH,*CH, Furan at 170' gives rise to tetrahydrofuran, >0, togetherwith a small amount of butyl alcohol and some saturated hydro-carbons.2I n some cases the reactions have showed signs of reversibility.The reverse change has been observed at 200-300' with indene andacenaph t hene when reduced to hy drindene and tetrahydroacenaph thene,but decomposition products also arise.The hydrogenation of naph-thalene to tetrahydronaphthalene which occurs at 200' is reversed a t300'.I n certain instances, hydr~genation,~ under ordinary pressures inthe presence of nickel, leads to the formation of secondary products,and even to the total suppression of the primary reaction. Quinoline,for example, is transformed into methylketol. When nickel oxide isemployed as the catalyst a t high temperatures (200-300') and underhigh pressures (100-200 atmospheres), the hydrogenation runs itsnormal course, and the method has proved remarkably successful inyielding highly hydrogenated products, which are obtained only withconsiderable difficulty by other pr;ocesses.Aniline yields principallyhexahydroaniline, together with cyclohexylaniline and dicyclohexyl-arnine. The last of these is the chief product of the hydrogenation ofdiphen ylamine.Quinoline is readily reduced, first t o tetrahydroquinoline, and thent o decahydroquinoline, an almost quantitative yield of the latter beingobtained. Anthracene can be reduced in three successive stages t odihydroanthracene, tetraliydroanthracene, and, finally, perhydro-ant hracene.Phenanthrene, which requires a higher temperature (320-370°/150-170 atmos.), is similarly reduced in stages to its dihydro-,tetrahydro-, and octahydro-derivatives, and, finally, perhydrophen-anthrene ; the yield of the last is so good that the method is recom-mended for the preparation of the compound.When potassium phthalate is mixed with nickel oxide and heated in1 P.Sabntier and A. RIailhe, Compt. rcizd., 1908, 146, 437, 1193; A . , i, 278,2 A. Eourgnignon, B i d . Soc. chiliz. Bch~., 1908, 22, 87 ; A., i, 280.3 M. Padoa and U. Ir'abris, Atti R. Accad. Lincei, 1908, [v], 17, i, 111 ; A., i,529.25576 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hydrogen at 300°/100 atrnos., an excellent yield of potassium trans-hexah ydrop hthala t e (ti*alzs-cycZo hexane- 1 : 2 - dicar boxyla t e) is produced.Sodium benzoate is readily converted into sodium hexa hydrobenzoate(cyclohexanecarboxylate), the potassium salt being less affected.Experiments conducted under ordinary pressures show that thenickel oxide acts as a catalyst only under high pressures.On theother hand, the presence of the catalyst is essential in the foregoingreductions, for heating with hydrogen alone under high pressure doesnot lead to the hydrogenation of the organic compounds.4The use of metals as catalysts at high temperatures has led to therepetition and extension of certain old experiments on the use ofplatinum-black in reductions carried out on substances in solution.Compounds containing the ethylene linking are readily reduced withhydrogen in the presence of this catalyst even at the ordinary tem-perature. Ethyl oleate in ethereal solution gave ethyl stearate inquantitative yield, and oleyl and erucyl alcohols were similarlyreduced to the fully saturated alcohols. Geraniol was convertedinto a mixture of P(-dimethyloctane and yy-dimethyloctanol.Cholesterol in ethereal solution furnished a dihydrocholesterolidentical with /3-cholestanol.Aromatic substances can be hydro-genated to hydroaroma,tic derivatives by this method, but somewhatless readily than by the high temperature processes; benzoic acid, f o rexample, gives about 12 per cent. of cyclohexanecarboxylic acid.5A powerful catalytic reducing agent has been prepared by addinghydrazine to a solution of palladium chloride and sodium protoalbinate,when the hydrosol of palladium is formed. The colloidal solutiontakes up a large amount of hydrogen, and when unsaturated sub-stances are dissolved therein, and the liquid left in contact withhydrogen, the gas is quickly absorbed, and an energetic reduction iseffected.Fumaric (maleic) and cinnamic acid in the form of theiralkali salts are converted into succinic and P-phenylpropionic acidsrespectively. The method is applicable to the unsaturated glyceridesoccurring in many fats and oils ; these substances are quantitativelyconverted into the saturated glycerides, this being the only processyet discovered which will effect this reduction at the ordinarytemperature.6Hydrogenation is not the only chemical change promoted by thecatalytic influence of inorganic materials. Dehydration of alcoholsW. N. Ipatieff, Ber., 1908, 41, 991 ; W. N. Ipatieff, W. Jakowleff, andL. Rakitin, *id., 1908, 41, 996 ; W.N. Ipatieff and 0. Philipoff, ibid., 1908, 41,1001 ; A., i, 330, 332, and 342.R. Willstiitter and E. W. Mayer, ibid., 1908, 41, 1475, 2199 ; A., i, 383, 636.C. Paal and J. Gerum, ibid., 1908, 41, 805, 2273 ; A., ii, 392, i, 599 ; C. Paaland-K. Roth, ibid., 2283 ; A., i, 599ORGANIC CHEMISTRY. 77and similar substances is induced by certain oxides. Precipitatedalumina and silica, when dried and gently calcined, promote thedecomposition of ethyl alcohol into ethylene and water at temperaturesmuch below those at which heat alone would be effective in decom-posing this substance. At 280' the alcohol is quantitatively decom-posed into water and ethylene. Prolonged calcination diminishesvery considerably this catalytic pbwer, for after being heated a t a whiteheat, the oxides have no effect on the alcohol below 400°, and thenonly a small amount of ethylene is produced.At 300' in the presence of gently-calcined alumina, ether isdecomposed into ethylene and water, the reaction being recommended asa process for preparing this hydrocarbon. Acetic and propionic acidsat 350' give respectively acetone and methyl ethyl ketone, togetherwith carbon dioxide and water.Alumina also induces the eliminationof hydrogen halides : a t 280' chloropropane gives propylene, andethylene dichloride yields vinyl chloride.Carefully-calcined gypsum promotes the decomposition of alcohol at420°, 90 per cent. of the gas evolved being ethylene and the resthydrogen. Anhydrite has no effect below 460".Aluminium silicateand kaolin have been shown to possess in some degree this catalyticpower, which is somewhat diminished by calcination.7When heated alone theprimary aliphatic alcohols decompose at a red heat into (i) water andan olefine and (ii) hydrogen and an aldehyde, but they show noappreciable decomposition below 400'. I n contact with finely-dividedcopper, nickel, cobalt, iron, and platinum, the alcohols undergodehydrogenation at about 350°, the products being hydrogen andan aldehyde. At the same temperature, certain oxides, and particularlyalumina, induce dehydration, the products now being water andan olefine.The Grignard Reaction.Although every year sees a great increase in the applications of theGrignard reaction in the synthesis of organic compounds, the exactmechanism of the process is even yet imperfectly understood, especiallyin respect of the true nature of the intermediate additive products.The complexes which the reagent forms with ether are geperallyuncrystallisable, but it has now been found * that by the employmentof amyl ether in place of ethyl ether, crystalline compounds, such as(C,H,,),O,CH,MgI, may be prepared.Whilst magnesium alkylhalides can also add on a second molecule of ether, the additive com-pounds with tertiary amines never contain more than one mol. of theJ. B. Senderens, Compt. rend., 1908, 146, 125, 1211 ; Bull. Soc. chint., 1908,[iv], 3, 633 ; A., i, 494, 496, i, 168.T. Zerewitinoff, Ber., 1908, 41, 2244; A., i, 616.A few general principles are apparent78 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.latter.They are, however, capable of combining also with a moleculeof ether, yielding mixed ether-amino complexes. Replacement ofether by amine, or conversely, may take place, the change proceedingin the one or the other direction according to the relativestability ofthe resulting additive compounds, as shown by thermochemicalmeasurements. Ethers are not capable of expelling aliphatic amines,the final product being one containing one mol. of ether and one mol. ofz~mine.~ It is concluded from these results that addition takes place attwo dissimilar positions in the molecule of the magnesium organichalide.The Grignard reaction may also take place, although less readily andless smoothly, in the absence of ether or even of a solvent.Aromatichalogen compounds combine with magnesium almost quantitatively onheating, and the products react with water, yielding the parent hydro-carbon. Aryl chlorides, and the halides of alkyls lower in the series thanamyl, must be heated in a sealed tube a t 270'. Bromo- and iodo-benzene yield some diphenyl as well as benzene, and the lower alkyliodides give rise to hydrogen and unsaturated hydrocarbons in additionto the principal product. These results indicate that the first stage inthe reaction is the direct addition of magnesium to the alkyl or arylhalide, and that the formation of an oxonium compound in the presenceof ether is a subsequent stage.10Other metals behave in a simi1a.r manner to magnesium when heatedwith organic halides.The products obtained with aluminium, indium,and thallium yield the hydrocarbons on treatment with water.l1The varying degree in which metals of different groups are capableof replacing magnesium in the Grignard synthesis has been studiedand tabulated.l2From the action of sodium and alkyl halides on certain compounds,the intermediate formation of sodium alkyl seems to be established.Thus acetophenone, isoamyl iodide, and sodium yield phenylmethyliso-amylcarbinol, OH*CPhMe-C,H,,. A mixture of sodium with amercury dialkyl, which must contain a mercury alkyl compound, mayalso be used. Thus mercury diethyl, sodium, and benzaldehyde reactin ether to form phenylethylcarbinol, identical with that obtained bymeans of Grignard's reagent.Carbon dioxide forms the correspondingcarboxylic acid with a mixture of sodium and mercury alkyl.Aromatic acids may be prepared by the action of carbon dioxide onthe same mercury alkyl-sodium mixture in presence of an aromaticW. Tschelinzeff, Ber., 1908, 41, 646; A., i, 254.lo J. F. Spencer and E. M. Stokes, !Z'mns., 1908, 93, 6 8 ; J. F, Spencer andl1 J. F. Spencer and M. L. Wallace, ibid., 1908, 93, 1827.la J. Zeltner, J . pr. Chem., 1908, [ii], 77, 393 ; A!., i, 401.M. S. Crewdson, ibid., 1821ORGANIC CHEMISTRY. 79hydrocarbon. When a side-chain is present, the carboxyl group entersthis, so that, for instance, m-xylene gives na-tolylacetic acid, and ethyl-benzene gives a-phenylpropionic acid.13Magnesium aryl chlorides, which cannot be prepared by theordinary method, are readily obtained when the reaction betweenthe metal and the aryl chloride is induced by the introduction ofa more reactive halide, such as ethyl iodide.14The chlorine in chlorodimethyl ether is not replaceable bymagnesium, even when iodine is added, but this ether reacts vigor-ously with magnesium phenyl bromide, giving benzyl methyl ether,and this reaction is found to be general.15Among new Grignard syntheses to be noted are the production of/3-ketonic esters from a-halogen fatty esters :JfgCHRBr*CO,Et -+ CH,R*CO*CHR*CO,Et ;the production of propiolic acid by the action of carbon dioxide onmagnesium acetylene bromide l7 :CHiC*MgBr+ CO, -+ CHiC*CO,H,and the preparation of thienyl derivatives from iodothiophen.ls Thus2-iodothiophen and acetone condense with magnesium in etherealsolution, yielding thienyldimethylcarbinol and P-thienylpropylene :C,SH,*C ICTe,-OH -+ C,SH,*CMe:CH,.Anhydrides of dibasic acids generally react with Grignard's reagentin such a way that both the carbonyl oxygen atoms are replaced by alkylor amyl groups, succinic anhydride, for instance, giving compounds ofthe type CH2*CR2*oH ICH,-CR, OH'Camphoric anhydride, on the other hand,reacts aboormally, only one oxygen atom being replaced, giving amixture of the isomeric dialkyl-campholides l9 :C H,-CH-CR, CH,-CH-CO I bMe, >O and 1 bMe,>.CH,*CIlEe* CO CH,.CMe*CR,I Il 3 P. Schorigin, Bcr., 1908, 41, 2711, 2717, 2723 ; A., i, 866, 881, 886.l4 A.Hesse, D.R.-P. 189476 ; A., i, 592.l5 A. Reychler, Bull. SOC. chim., 1907, [iv], 1, 1198 ; A., i, 159 ; J. L. Hamonet,l6 J. Zeltnbr, Ber., 1908, 41, 589 ; J. pr. Chem., 1908, [ii], 78, 97 ; A., i, 243,l7 B. Oddo, Gnxzctta, 1908, 38, i, 625 ; A., i, 748.ibid., 1908, [iv], 3, 254 ; A . , i, 242.759.V. Thomas, Compt. rend., 1908, 146, 642 ; A., i, 360.J. Houben and A. Hahn, Ber., 1908, 41, 1580 ; A., i, 53980 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.o-Phthalaldehyde forms dihydroxyalkylbenzenes, which on distilla-tion pass into 1 : 3-dislkylphthalans 20 :Since C-alkylated primary bases may be prepared by the action ofmagnesium organic compounds on Schiff’s bases, the hydramides,CHRT*CHR*N:CHR, which contain the characteristic grouping ofSchiffs bases twice, have been examined from the same point of view.The reaction is, however, abnormal, addition at the unsaturatedgroupings being accompanied by the resolution of a carbon-nitrogensingle linking, according to two different schemes :(I). CHPh(N:CHPh), with MgMeI, followed by water, -+CHMePh-NH, + NH(CHMePh),.(11). CHPh(N:CHPh), -+ CHO*Ph + NH,*CHMePh,magnesium aryl halides reacting only according to the second scheme.21A reducing action of magnesium organic compounds has also beenobserved in the aliphatic series.Thus ethyl hydroxypivalate,OH*CH,*CMe,*CO,Et, reacts with magnesium ethyl bromide, theketone formed being partly reduced, especially at low temperatures,with evolution of ethylene, forming pp-dimethylpentane-ay-diol,C H,Me CH(0H) * CMe,* CH,* OH.The Friedel and Crafts Reaction.In the condensation of phthalic anhydride with benzene, it is foundthat the presence of exactly one (double) molecule o€ aluminiumchloride is necessary to bring about the reaction, and the formationof an intermediate product is thus rendered highly probable :Naphthalene will not readily condense with phthalic anhydride inan indifferent solvent under the influence of aluminium chloride, butwhen benzene or one of its homologues is added, the whole of thenaphthalene reacts to form naphthoylbenzoic acid, even although thebenzene may be in great excess.Naphthalene (or anthracene) isthus capable of displacing benzene from the additive product.22When nitro-compcunds are condensed with hydrocarbons, the nitro-group is eliminated, and some oxidation takes place.Thus trichloro-nitromethane and benzene react in presence of aluminium chloride,giving triphenylmethane and some triphenylcarbinol, the latter2o F. NelkenandH. Simonis, Ber., 1908, $1, 986; A., i, 348.21 M. Busch and L. Leefhelm, J. pr. Chem., 1908, [ii], 77, 1, 20; A., i, 151,22 G . Heller and K. Schiilke, Ber., 1908, 41, 3627 ; A., i, 994.153ORGANIC CHEMISTltY. 81produced by oxidation. Ethyl nitrate under similar conditions actsas a nitrating agent, giving nitrobenzene with benzene. Benzeneamyl nitrite, and aluminium chloride give small quantities ofnitrosobenzene.23When benzene is condensed with carbon tetrachloride, the chlorineatoms are replaced in pairs, the first product capable of isolationbeing dichlorodiphenylmethane, no trichloro-compound being detected :A study of the behaviour of halogen derivatives of benzene in thisreaction, the condensation product being subsequently boiled withsulphuric and acetic acids, leads t o the conclusion that the substitu-tion is not simultaneous, but that the velocity of replacement of thesecond chlorine atom is very great.24CCl, + 2C6H6 -+ CCl,Ph2.The Claisen Condensation.Although several different explanations of the Claisen condensationhave been suggested by different workers, that put forward by Claisenin 1887 is still the most generally accepted, namely, that the ester firstforms an additive compound with sodium ethoxide. A study of thevelocity of formation of ethyl acetonyloxalate from acetone, ethyloxalate, and sodium ethoxide in alcoholic solution, as measured by thecolour produced by ferric chloride after neutralisation, is interpretedby Clark as favouring this explanation when the dependence ofthe velocity on the concentration of the reacting substances is takeninto account.25 A quantitative comparison of different reacting esters,and of the influence of catalysts shows that, as required by thishypothesis, the addition of alcoholic sodium ethoxide greatlyaccelerates the reaction between ketones and esters in presence ofsodium.26On the other hand, experiments with menthone and pulegone,reacting with amyl nitrite (instead of a carboxylic ester) in presenceof sodium ethoxide, shows that the group 'CH2*CO*CH: is attacked,not at the *CH,*CO* point, as might be expected, but at the *CO*CH:gro~p.~7 A discussion of the mechanism of this reaction leads to theconclusion that, as suggested by several authors, the metallic derivativeof the ketone must react to some extent in the C-form.In other words,there must be in the solution a real or virtual equilibrium (that is,either an equilibrium of the ions or one within the molecule itself,Q E. Bodtker, BuIl. Soc. chin?., 1908, [iv], 3, 726 ; A., i, 621.24 J. Boeseken, Rec. trav. ehim., 1908, 27, 5 ; A , , i, 189.25 R. H. Clark, J. Physical Cheqn., 1908, 12, 1 ; A., i, 124.26 J. R. Tingle and E. E Gorsline, Amr. Chenz.J., 1908, 40, 46 ; A., i, 732.27 R. W. L. Clarke, A. Lapworth, and E. Wechsler, Trans., 1908, 93, 30.REP.-VOL. V. 82 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.without actual dissociation) between the C-sodium and theO-sodium derivatives ::C:&*ONa Z :CNa*d:O.These C-metallic derivatives must react in a similar manner toorgano-metallic compounds, and the aceto-acetic ester synthesis thusbecomes a particular case of the reaction between esters and organo-metallic compounds. The authors give a theoretical discussion of thewhole question on this basis.The reversibility of the acetoacetic condensation, that is, thedecomposition of the diketone by sodium ethoxide, is found to dependon the acidity of the compound, the more acid its character thogreater being its stability.Thus methyl y-acetyldimethylaceto-acetate, CH,*CO*CH,*CO*CMe,*CO,Me, is hardly attacked by sodiumethoxide even on boiling, but when the acidity of the centralmethylene group is reduced by methylation, as in ethyl trimethyl-acetonedicarboxylate, CO,Et*CHMe*CO*CMe,*CO,Et, this power ofresistance disappears.28Esterijcation and Catalysis.Perhaps the most interesting problems in connexion with theformation of esters from acids and alcohols are the influenceof catalysts on the velocity of the reaction and the effect ofsteric hindrance, both of which have received attention during thepast year. The influence of catalysts in tha formation of ethylbenzoate has been the subject of a very extensive series of measure-rnent~,~g the results of which prove that a large number of factorsenter into the process, but do not allow any general conclusion to bedrawn.The efficiency of the catalyst could not be shown to dependon its degree of ionisation. The effect of neutral salts is also acomplex one, and dehydration plays a considerable part, as urged byH. E. Armstrong in numerous papers.An important theoretical paper has quite recently appeared dealingwith the general catalytic function of hydrogen ions.30 The treatmentof the subject is mainly physical and mathematical; so far asesterification and ester hydrolysis are concerned, the most strikingsuggestion is that the addition of water to an acid in a less basicsolvent diminishes the availability of the acid, or diminishes the28 W.Dieckmann and A. Kron, Ber,, 1908, 41, 1260 ; A . , i, 388.cg I. K. Phelps, M. A. Phelps, E:. A. Eddy, H, E. Palmer, R. JV. Osborne, andR. Smillie, Amer. J. Xci., 1908, [iv], 25, 39 ; 26, 281, 290, 296 ; A . , i, 166, 789,790.30 A. Lapworth, Tmas., 1908, 93, 2203 ; E. Fitzgerald and A. Lapworth, ibid.,2163ORGANIC CHEMISTRY. 83concentration of those u ions ” which bring about catalysis. Theseions are not identical with the “hydrogen ions” to which theelectrical conductivity is due, which are probably complex. Theideas propounded are likely to form the basis of an interestingdiscussion of the nature of catalysis.Many experiments on the catalytic function of acids in the hydro-lysis of imino-esters,31 the formation of 0ximes,3~ and the acetylation ofamino-groups 33 have also been made, and the importance of consideringthe basic character of the substances undergoing change is in allcases pointed out.An examination of the absorption spectra of certain unsaturatedketonic compounds, of which cinnamylideneacetic acid and cinnamyl-ideneacetone are types, leads to conclusions of some interest inconnexion with the different rate of esterification of different acids.%It has been conjectured that the process of esterification depenas onthe residual affinity of the carbonyl group in the acid, to which thealcohol adds itself.The spectroscopic evidence shows that theresidual affinity of a carbonyl group is greatest when the atomattached t o the hydroxylic oxygen is not ionised, the effect of addingan acid, and thus diminishing the ionisation of the organic acid,therefore being to increase the residual affinity of the carbonyl.I nconnexion with this, the effect of small quantities of hydrogen chlorideon the spectra of aromatic amino-aldehydes and -ketones has beenexamined. The development of a new band indicates that theresidual affinity of the arnino-group is increased by such addition, andthis would account for the catalytic action of acids i n the acetylationof such compounds.35The effect of steric hindrance is illustrated by experiments witharylated acetic acids.36 Triphenylacetic acid is much more difficult t oesterify than trialkylated acetic acids, the introduction of the thirdphenyl group having also a much greater effect than that of thefirst or second.The same thing is shown by a comparison ofbenzilic acid, CPh,*C(OH)*CO,H, with glycollic and mandelic acids,the phenyl group having a far greater influence than hydroxyl inretarding esterification.31 J. Stieglitz, Anter. Chem J., 1908, 39, 29, 166 ; A . , i, 167, 168.32 S. F. Acree, ibid., 300; A., i, 169.Zd A. E. Smith and K. J. P. Orton, Trans., 1908, 93, 1212.3 . ~ E. C. C. Baly and K. Schaefer, ibid., 1808.35 E. C. C. Baly and E. G. Marsden, ihid., 2108.36 J. Gyr, Ber., 1908, 41, 4308; A., 1909, ii, 33.a 84 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Simple Hydrocurbons and Aliphatic Derivatives.The complicated and much discussed problem of the behaviourof the simpler saturated and unsaturated hydrocarbons a t high tem-peratures has been submitted to further experiment, with the resultthat methane is found to be always the main product of the thermaldecomposition of ethane, ethylene, and acetylene. Methane itselfdecomposes directly into carbon and hydrogen, mainly at the contactwith the walls of the vessel, whereas the other hydrocarbons undergodecomposition throughout their mass.Acetylene is only producedin notable quantity from ethylene.37 The authors suggest that suchresidues as :CH2 and iCH have a t least a momentary existence, andgive rise to methane by combination with hydrogen. All theseprocesses take place slowly in comparison with those of combustion.The direct formationrof methane from carbon and hydrogen, whichmas questioned by Mayer and Altrna~er,~* has now been placed beyonddoubt by the production of 73 per cent.of the theoretical quantity ofmethane by the action of hydrogen on purified carbon.39Aliphatic derivatives of great complexity are of frequent occurrencein recent chemical literature, and the need of further classification hasbeen felt. Meldola 4O has proposed the grouping of open-chain systemsinto those composed respectively of similar and dissimilar atoms, andhas suggested for these, from analogy to homocyclic and heterocycliccompounds, the designations “ homocatenic ” and ‘‘ heterocatenic,”the latter including, for instance, the long chain-systems of thepolypeptides.The interesting and highly reactive group of the ketens has beenfurther studied.The parent substance, keten, CH,:CO, the isolationof which was announced last year 41 as a product of the thermaldecomposition of acetic anhydride, has been proved to have theconstitution then assigned to it. It has also been found possiblet o prepare it by the general method for the production of ketens,namely, by the action of zinc on bromoacetyl bromide :CH,Br*CO*Br + Zn = CH,:CO + ZnBr2.42The simplest polymerisation product of keten is acetylketen,CH,*CO*CH: GO,a colourless liquid, which reacts with water to form acetoacetic acid,37 W. A. Bone and H. F. Coward, Trans., 1908, 93, 1197.38 Ann. Report, 1907, 74.39 W. A. Bone and H. F. Coward, Trans., 1908, 93, 1975.4* Trans., 1908, 93, 1665, footnote.41 Ann.Xeport, 1907, 85.42 H. Staudinger and H. W. Klever, Ber., 1908, 41, 594 ; A., i, 246ORGANIC CHEMISTRY. 85and with aniline to form acetoacetanilide. With phenylhydrazine itforms a phenylhydrnzone-phenylhydra~ide.~~A new method for the preparation of dimethyl- and diethyl-ketenhas been found in the decomposition of di-substituted malonicanhydrides by heat :The anhydrides required for the above reaction are prepared byheating the semi-chlorides of the acids ; they are highly polymerised.A second method of preparation is that of treating the acid dichlorideswith aqueous pyridine.45When, instead of dialkylmalonic acids, malonic acid is treated by amethod for producing the anhydride, as by the action of acid chlorideson eilver malonate, or of silver oxide on malonyl dichloride, keten isnot produced, but in its place carbon suboxide is obtained, thehypothetical intermediate anhydride thus decomposing according tothe equation :c H , < ~ ~ > O = C<Eg 3- H,O.Dibromomalonyl dichloride, CBr,(COC1)2, readily reacts with zinc,giving a good yield of carbon sub~xide.*~These methods of preparation indicate that carbon suboxide isitself to be regarded as a keten.It combines with formic and aceticacids to form compounds in which the characteristic structure appearsto be preserved, the formic acid compound, fok instance, reacting inaccordance with the formula c02H>C:C:C<g2H. OH The acetic acidcompound breaks up in a remarkable manner on heating, yieldingacetic anhydride and a syrup which is completely converted by waterinto malonic acid.Whilst this substance may be only a polymerideof carbon suboxide, it is a t least possible that it may represent thehitherto unknown malonic anhydride, CH,<c0>o.47A comparison of the properties of the ketens now known hassuggested their classification in two groups, of which the first includesketen and its monoalkyl derivatives and carbon suboxide, all of whichare colourless, incapable of autoxidation, and are polymerised bypyridine. They are termed aldoketens. The members of the secondgroup, consisting of the di-substituted ketens, are coloured, undergoco43 F. Chick and N. T. M. Wilsmore, Trans., 1908, 93, 946.44 H. Staudingar and E. Ott, Bw., 1908, 41, 2208, 3829 ; A., i, 602, 939.45 A.Einhorn, Annalen, 1908, 359, 145 ; A., i, 312.46 H. Staudinger and S. Bereza, Ber., 1908, 41, 4461 ; A., 1909, i, 83.47 0. Diels and L, Lalin, i6id., 1908, 41, 3426 ; A., i, 9386 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.autoxidation, yield keten bases with pyridine, and, unlike the aldo-ketens, yield additive products with benzylideneaniline and quinonecontaining the groups C:N and C:O respectively, They are termedketo-ketens. Thus diphenylketen combines with quinones to formp-lactones, such as 0: C , H , ~ ~ ~ > C O , which decompose whenheated, giving derivatives of diphen ylquinonemethane. The additivecompound with dibenzylideneacetone loses carbon dioxide sponta-neously, the product being aediphenyl-y-diphenylmethylene-Aaa-pentadiene,CH:CHPhCPh,:C< C H : C HP h'a compound belonging to a class yhich may be described as acyclicfulvenes, from their resemblance to the fulvenes :CH,:C< CH:$?HCH:CH'Their colour is much less intense than that of the fulvenes, as mightbe expected from the absence of the ring structure.4sPrevious attempts to prepare the aldehyde of lactic acid, thesimplest methyl sugar, have failed, and it has been conjectured that itmust isomerise to acetol :CH,*CH(OH)*CHQ -+ CH,*CO*CH,*OH.It has now been found that its acetal may be prepared by thereduction of methylglyoxalacetal :CH,*CO*CH~OEt), -+ CH,*CH(OH)*CH(OEt),,and the latter compound, which may be regarded as the methyl ketoneof diethoxyacetic acid, may be prepared by the action of magnesiummethyl iodide on the amide of that acid.It was found better toemploy the piperidide, from which the acetal was readily prepared. Thelactaldehydeacetal obtained on reduction was readily decomposed byacids, yielding the bimolecular crystalline form of lactaldohyde, whichslowly dissociates in solution, as shown by determinations of themolecular weight .49The condensation of malonic acid with acetone in the presence ofacetic anhydride leads to the formation of the p-lactone of P-hydroxy-isopropylmalonic acid (I). It is remarkable that the only otheraliphatic /3-lactone known is an isomeride of this (11) derived fromas-dimethylmalic acid : 5O7Me,*7H*C02H ?Me,* 7"- C0,H(I) o--CQ (11) (70-048 H.Staudinger, Be?., 1908, 41, 906, 1355, 1493; A., i, 318, 410, 411.49 A. Wohl, ibid., 1908, 41, 3599 ; A., i, 941.50 A. N. Meldrum, Tram., 1908, 93, 598ORGANIC CHEMISTRY. 87The oxidation of butyric acid to acetone is probably typical of anumber of oxidations which take place in the living plant, and anexamination of this reaction proves that it is readily effected in thecase of the higher acids. Thus lauric acid iwoxidised’by hydrogenperoxide: an unstable ketonic acid is the first product, readilypassing into methyl n-nonyl ketone.50aCarbohy dyates.Further evidence for the y-oxidic formula for glucose and otherreducing sugars has now been brought forward. Thus glucoseanilideexists in two stereoisomeric modifications, and on methylation yieldstetramethyl glucoseanilide, identical with that ,prepared from tetra-methyl glucose.Similarly, glucoseoxime is methylated to tetramethylglucoseoxime methyl ether. That the tetramethyl derivatives possessthe y-oxidic structure is shown by the impossibility of furthermethylittion, since an aldehydic derivative would allow of theintroduction of two more methyl groups. The oxime therefore hasthe constitution :OMe*CH,*CH(OMe)*CH*CH(OMe)*CH(OMe)*CH*NH*OHand exists i n two stereoisomeric modifications. A similar result wasobtained with the anilides. The results of acetylation and reductionof glucoseoxime are ditficult t o reconcile with the formula proposed,but it is pointed out that the reagents used in these cases are moreliable to cause isomeric change than the methyl iodide and silver oxideused in m e t h y l a t i ~ u .~ ~The mutarotation of lactose has been shown to be due t o thegradual establishment of equilibrium between the hydrated a-modifi-cation and the anhydrous P-modification. I n the scheme below, thefirst equilibrium is attained instantly, the second only slowly : 52I I ? 0a-form + H,O z=? hydrated form Z H,O + p-form.The change of dextrosephenylhydrazone into the isomeric modifica-tion is accelerated by acids and retarded by alkalis. It is suggestedthat, if not syn- and anti-modifications, one of the isomerides may bethe true hydrazone and the other one of the stereoisomeric forms ofthe y-oxidic derivative, as suggested by Irvine for the oxime andanilide : 53OH*CH,*CH(OH)*CH C H (OH)*CH(OH)*CH*NH*NHPh.I A I50a H.D. Dakin, J. Bid. Chem., 1908, 4, 221 ; A., i, 134.51 J. C. Irvine and A. M. Moodie, l’&xns., 1908, 93, 95 ; J. C. Irvine and59 C. 8. Hudson, J. Amer. Chem. Soc., 1908, 30, 1767 ; A., i, 952.53 R. Rehrend and F. Lohr, Annulen, 1908, 362, 78 ; A., i, 765.R. Gilmour, ibid., 142988 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.When pure glycerose is polymerised by contact with colloidalbarium carbonate in methyl alcohol, a pentose is formed. It thusappears that polymerisation does not take place directly, but that thesimple sugar is first depolymerised to f~rmaldehyde.~~ The view hasalso been taken that alcoholic fermentation consists in a breakingdown of the sugar molecule to formaldehyde, followed by the conversionof this into alcohol and carbon dioxide.Formaldehyde is convertedby zinc carbonate into formic acid, methyl alcohol, acetol, and methyl-ketol. Zinc dust reacts in the same way, the product then includingseveral sugars, among which p-acrose could be detected, and poly-hydroxy-acids. Dextrose and zinc dust yield formic acid,diacetyl, methylglyoxal, and polyhydroxy-acids, but no methylThe action of dilute alkalis on the hexoses has been further studied.Since alkalis have been found to convert aldoses partly into thecorresponding hexoses, it should be found that Z-gulose and 2-idoseshould be converted into 2-sorbose, and this was confirmed. As mightbe expected from the fact that dextrose and lrevulose form an equi-librium mixture in alkaline solutions, these two sugars are found tobehave similarly on prolonged treatment with dilute alkali.Theprincipal product of decomposition is i-lactic acid, but poiyhydroxy-acids and small quantities of formic acid, carbon dioxide, and alcoholare also formed.56 The lactic acid formed in these experiments isalmost certainly produced from methylglyoxal, dihydroxyacetone,or glyceraldehyde. An examination of the polyhydroxy - acids,however, leads to conclusions which are not in accordance withthose of Nef,b7 saccharins with less than six carbon atoms beingundoubtedly present. Nef's views, also, would indicate that iso-saccharinic acid should be readily obtained from lzevulose, but this isnot the case, only a very small yield being obtained.On the otherhand, lactose gives a considerable yield of isosaccharinic acid.58Of other carbohydrate problems, that which has led to the mostdiscussion is the question of the chemical behaviour of cellulose,especially on esterification. Analyses of several anhydrous poly-saccharides indicate that the generally-accepted formula for starch,cellulose, etc. (C6H1,,05)n, is incorrect, and should be replaced by(C6Hlo05)n,H20. I n raffinose, melezitose, and mannasaccharide, = 3 ;in inulin, f i = 6.5954 C. Neuberg, Bwchem. Zeitsch., 1508, 12, 337 ; A., i, 765.55 U'. Lob, ibid., 78, 466 ; A., i, 715, 765.56 J. Meisenheimer, Ber., 190%, 41, 1009 ; A.: i, 319.57 Ann. Report, 1907, 87 ; also Annnlen, 1907, 357, 214 ; A., i, 5.58 H.Kiliani, Ber., 1908, 41, 469 ; A., i, 246.69 H. Kiliani, Chent. Zeit., 1908, 32, 366 ; A., i, 320ORGANIC CHEMISTRY, 89Cellulose formate is prepared by the action of formic and sulphuricacids on cellulose, but the number of formyl groups introduced is asyet undetermined.60 A new acetylating agent, by means of whichthree acetyl groups are introduced, consists of 100 grams of glacialacetic acid, 50 grams of zinc chloride, and 100 grams of aceticanhydride. It does not react with starch.6l When cellulose isheated with nitric acid and acetic anhydride, the latter being inexcess, only nitrates are obtained, unless sulphuric acid is alsopresent, when some of the nitrate groups are removed and aceto-nitrates are produced.62 When mixtures of anhydrous sulphuricand nitric acids, the latter in large excess, are used, the cellulosenitrate always contains less nitrate groups than when more dilute acidis employed.63Agreement has not yet been reached between different observers ast o the true nature of ‘‘ soda-cellulose.” Whilst one observer finds adistinct break in the curve representing the partition of sodiumhydroxide between cellulose and water, at the composition correspond-ing with the formula C,,Hl,0,0Na,64 another, making use of theformer data as well BS of new measurements, concludes that no defi-nite composition can be assigned to the solid substance, but that theprocess is one of adsorption, closely resembling the behaviour ofpalladium towards hydrogen, and probably susceptible of the samephysical e ~ p l a n a t i o n .~ ~Isomeric Change and Tautomerism.The influence of catalytic agents in bringing about isomeric change,as shown by the mutarotation of nitrocamphor, has been investigatedin various solvents.66 That the presence of a catalyst is essential, andthat an ionising soivent is not itself capable of bringing about thechange, is shown by the complete arrest of mutarotation when carbonylchloride is added. This reagent combines with the traces of ammoniaor amines present in most of the solutions, and thus destroys theircatalytic function. The addition of acids does not have the sameeffect, as neutral salts also exert an accelerating action.A systematic review of the different forms of structural isomerismhas been given by the original author of the theory of tautomerism.6760 J.P. Bemberg, D.R.-P. 189836, 189837; A . , i, 322.81 D. ,T. Law, Chem. Zeit., 1908, 32, 365 ; A., i, 321.62 E. Berl and W. Smith, jun., Ber., 1908, 41, 1837 ; A., i, 505.63 B. Rassow and W. v. Bong&, Zeitsch. angew. Chem., 1908, 21, 732 ; A., i, 394.64 W. Vieweg, Ber., 1908, 41, 3269 ; A., i, 857.135 0. Miller, ibid., 4297 ; A., 1909, i, 13.66 T. M. Lowry and E. H. Magson, Trans., 1908, 93, 107, 119.67 C. Laar, J. pr. Chm., 1908, [ii], 78, 165; A,, i, 74990 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The thirty-nine types are classified by him according to the number OFchanges of linking involved, and, further, into those which respectivelydo and do not involve change of valency.The scheme affords a usefulreview of the labile types of isomerism.The equilibrium between ketonic and enolic modifications has beenstudied from many points of view. Michael, in a theoretical review ofthe whole subject,0* insists on the necessity of distinguishing clearlybetween desmotropy, the reversible transformation of two isomeridesinto each other through the wandering of a labile hydrogen atom, andmesotropy, the process of irreversible isomerisation during theformation of derivatives. I n subsequent papers, he and others haveinvestigated the suitability of various reagents for distinguishingbetween enolic and ketonic substances. The best modification ofHantzsch’s ammonia reaction consists in employing triethylamine ortripropylamine, and in noting the development of heat rather thanthe formation of a precipitate.69 This is quite satisfactory when thecompound is mesotropic, only enolic substances then reacting, butdesmotropic compounds are, as might be expected, generally convertedinto the more stable modification by the amine.The results obtainedwith phenylcarbimide 70 and with acetyl chloride or acetic anhydride71are also indecisive in such cases, for similar reasons.Ethyl oxalosuccinonitrile, CN*CH,*CH(CN)*CO*CO,Et, prepared bycondensing ethyl oxalate with succinonitrile, has been obtained 72 in anenolicnnd a ketonic modification, both of which are crystalline. Thelatter form dissolves alcohol in to a violet, fluorescent solution. I fconfirmed, this would be the first case of fluorescence observed in thealiphatic series, and Kauff mann has therefore suggested the presenceof a ring ; the chemical reactions, however, indicate that the compoundhas the simple structure assigned to it.The enolic (I) and ketonic (11) modifications of ethyl methylcyclo-hexenonedicarboxylate :CH( C02E t) CMe>CE CH(CO,Et)*CMeSCHCHf%( C0,Et) : C( OH) CH2<C€€(C02Et)--C0(1.1 (11.1are stated 73 to give different vapours when distilled, although bothmodifications have the same boiling point.Desmotropy has notpreviously been observed to persist in the state of vapour.6* A. Michael, Annaleqt, 1908, 363, 20 ; A., i, 943.6o A. Michael and H. D. Smith, ibid., 36 ; A . , i, 943.7O A.Michael and P. H. Cobb, ibid., 64 ; A . , i, 947.71 A. Michael and A. Murphy, jun., ibid., 94 ; A., i, 949.72 W. Wislicenus and P. Berg, Ber., 1908, 4.1, 3757 ; A., i, 965.73 P. Rabe, Annaben, 1908, 360, 289; A., i, 530ORGANIC CHEMISTRY. 929-Nitrofluorene has been isolated in two desmotropic forms, ofwhich the mi-form, (?6H4>C:NO*OH, is comparatively stable. It is ct3 *4prepared from fluorene; ethyl nitrite, and potassium e t h ~ x i d e . ~ ~The well-known tautomerism of cyclic ketones, such as phloro-glucinol and dihydroresorcinol, is also exhibited by monoketones con-taining a simple ring i f a sufficiently powerful reagent, such as anacid anhydride, be employed to detect the enolic. hydroxyl g r o ~ p . ~ 5 I nthis way, acetyl derivatives of the enolic forms of cyclohexanpe andits three methyl derivatives, and of menthone, cyclopentanone, andsuberone, have been prepared.Camphor gave no indication of anyacetylation.An addition t o the many physical properties which have beenutilised to give indications as t o the ketonic or enolic condition oftautomeric substances is made in a recent communication, which dealswith the viscosity of liquids of this class, these compounds being mixedwith various solvents.76 The measurements show t h a t ethylacetoacetate is partly enolised, both alone and in solution.The addition of piperidine has a marked effect in increasing theviscosity.The peculiar isomerism of di-o-derivatives of benzene, referred to inlast year’s Report (p. ill), and there considered in relation t oKekulB’s formula for benzene, has received surprisingly little attention,and it is therefore uncertain how far the formation of such isomeridesis a general one.A certain number of nitrated derivatives of benzene,it is true, have been shown to exist in two modifications, but this isnow attributed by the author77 t o isomerism of the nitro-group.Thus l-chloro-2 : 4-dinitrobenzene exists in a stable and in a highlylabile form, the two forms being chemically identical. The fact thatboth modifications have the same colour excludes the possibility thatone of them has the mi-constitution.The two modifications of 2 : 4-dinitrophenol, however, differ incolour, one of them being pale green in solution or when fused.Thetwo substances give a eutectic mixture, they form similar salts, andare formulated as :OH OH74 W. Wislicenus and M. Waldmiiller, Ber., 1908, LEI, 3334 ; A., i, 973.75 C. Mannich and V. H. HAncu, ibid., 1908, 41, 564; A . , i, 275.A. E. Dunstan and J. A. Stubbs, Truns., 1908, 93, 1919.I. Ostromisslensky, J. pr. Chem., 1908, [ii], 78, 263 ; A., i, 86892 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The very remarkable changes undergone by the aromatic fulgides, ofwhich triphenylfulgide,is a type, when exposed to light have been fully ~tudied.7~ Thechange from orange to brown, brought about by light, is strictlyreversible, but after frequent repetition of the change, an irreversibletransformation occurs, resulting in the formation of ‘‘ photo-anhydrides,” the investigation of which hits not yet been published.A thewetical discussion is at present hardly possible, but it may benoted that the triarylated fulgides (with one exception) and certainof those containing two aryl groups are phototropic, whereas tetra-phenylfulgide is not.Certain compounds outside this group behavein a similar manner.An isomeric change of a more definite character, also taking placeunder the influence of light, is that of carv0ne.7~ Whilst solutions ofdihydrocarvone were hydrolysed by exposure to sunlight, thusbehaving similarly t o other cyclic ketones, carvone was converted intoan isomeride, resisting the action of permanganate. It is suggestedthat a process of ‘‘ internal polymerisation,” such as that representedbelow, takes place :I CH,:C*CH3CW.==-C--COCH3The migration of acyl groups in certain instances will be discussedlater in connexion with the structure of hydroxyazo-compounds. Themigration of aryl groups in iodohydrins during the elimination ofhydrogen iodide has been exhaustively studied.80 Thus a-l-naphthyl-propylene, C,,H7=CH:CH*CH3, on treatment with mercuric oxide andiodine, is transformed into a-1 -naphthylpropaldehyde, the iodohpdrinisomerising and losing hydrogen iodide at the same time :CloH,*CH(OH)*CHI*CH3 --+ CHO*CH(CloH7)*CR,.Similarly, P-l-naphthylpropylene passes into a-naphthylacetone :CloH7*CMe:CH, -+ CloH7*CMe(OH)*CH21 -+ CH3*CO*CH2*CloH7.A case of wandering of bromine has been observed in the trans-formation of nitroamines.81 2 : 6-Dibromo-l-nitroaminobenzene under-CH,-CH-CH,III I 1co CH-C-- i P H 2 .Y *‘=3 --3 II ICH,cH2-cH--PH,78 H. Stobbe, Annalen, 1908, 359, 1 ; A., ii, 339.79 G. Ciamician and P. Silber, Ber., 1908, 41, 1928 ; A., i, 555.80 M. Tiffeneau, Bull. Soe. chim., 1907, [iv], 1, 1205; Compt. rend., 1908, 146,29 ; 147, 678 ; A., i, 165, 166, 972.K. J. P. Orton and C. Pearson, Trans., 1908, 93, 725ORGANIC CHEMISTRY. 93goes rearrangement in the usual way t o 2 : 6-dibromo-4-nitroaniline,but at the same time a part of it forms the isomeric 2 : 4-dibromo-6-nitroanilineY the migrating nitro-group actually expelling a bromineatom, which re-enters the nucleus in a different position :BrBrII \ RrWith s-tribromo-1-nitroaminobenzene, the same change takes place,but the para-position now being occupied, the bromine is unable to re-enter the nucleus, and is found in the solution.I n concluding this section, reference should be made to theinteresting method of studying the process of isomeric change byobserving the change in rotatory power of an active solvent, not itselfundergoing change, as described in last year’s Report (p.184). Themethod is particularly applicable to the oximes, and one case has beeninvestigated, that of p -iodobenz-sym-aldoxime,:in which no other methodfor measuring the velocity of change is available. The change inrotation of n-propyl tartrate brought about by the presence of W-iso-nitromethane undergoing change to the stable nitro-compound :is less than that due to the oximes, but is still considerable.Thechange of ammonium cyanate and thiocyanate into carbamide andthiocarbamide respectively may be followed by dissolving a portion ofthe substance which is being heated from time to time in an aqueoussolution of ethyl tartrate and measuring the rotation, or in theformer case, by allowing the change to take place in the ethyl tartratesolution.82Oxonides.C,H,*CH:NO* OH --+ C6H5*CH2*N02,The value of the ozone method for recognising the presence ofethylenic linkings continues to be disputed. Whilst Molinari statesthat such linkings only are attacked by ozone, Harries finds that sub-stances containing triple linkings also react readily with ozone to formunstable products having the properties of ozonides.It is suggestedthat the differences observed may be due to the fact that Molinariemploys ozonised air, and Harries, the presumably more energeticozonised oxygen. The simpler olefines yield very stable ozonides,which may be distilled in a vacuum, when treated with ozone in an82 T. S. Patterson and A. McMillan, Trans., 1908, 93, 104194 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.indifferent s0lvent.~3taining a chain of three oxygen atoms :The formulation of such compounds as con->y-y<0 0\/0is not in accordance with their optical constants, and it appearsrather that only two of the oxygen atoms have an ether linking, thethird being “carbonyl oxygen,” but further study is required before adefinite formula can be assigned to them.The decomposition productsof ozonides of oleic acid and triolein by water and alkalis are verycomplex, although the saponification number I’ of such compounds isa fairly definiteAZiphatic Diaxo- and T~iuxo-compounds.I n 1907 an investigation of the action of sodium azide on variousdiazonium salts led to the production of a number of aromatic azides,of which the most noteworthy mere the hydroxyphenylazoimides,obtained from the aminophenols, and the t riazo-derivatives of thenaphthalene series, prepared from the isomeric nitronaphthalene-diazoniurn ~ a l t s . ~ 5An extension of this research to the aliphatic series has resulted inthe isolation of triazo-derivatives of the simplest organic compounds.By double decomposition, ethyl chloroacetate and sodium azide havefurnished ethyl :triazoacetate, N,*CH,*CO,Et, from which triazoaceticacid, N,*CH,*CO,H, and triazoacetamide, N,*CII,-CO*NH,, have beenprepared by the usual methods. The simplest triazo-ketone, acetonyl-azoimide, or triazoacetone, N,*CH,* CO* CH,, has been obtained, andcompared with its cyclic analogue, camphorylazoimide. Triazoacet-oxime has been isolated, and the isomeric ethyl a- and p-triazo-propionates have been prepared, but only the former ester could behydrolysed into a-triazopropionic acid, CH,*CH(N,)*CO,H, the p-esterbeing decomposed by caustic alkalis, and even by ammonia, with theelimination of the triazo-group.Triazoethyl alcohol, N,*CH2*CH,0H,and triazoacetaldehyde, N,*CH,*COH, mere obtained from ethylenechlorohydrin and chloroacetaldehyde ; the former mas a fairly stablesubstance, giving rise to esters, such as triazoethyl acetate,CH,*CO,*CH,*CH,N,,isomeric with ethyl triazoacetate, and the latter was an extremely explo-sive and unstable liquid, which was decomposed by hydroxylamine,phenylhydrazine, and other reagents for aldehydes.C. D.Harries and K. Haeffner, Ber., 1908, 41, 3098 ; A , , i, 846.84 E. Molinari, ibid., 585, 2782, 2789, 2794 ; A., i, 244, 849.s5 M. 0. Forster and H. E. Fierz, Tram., 1907, 91, 855, 1350, 1942ORGANIC CHEMISTRY. 95The refraction and dispersion of certain of these triazo-compoundswere determined, so also were the dissociation constants of triazo-acetic and a-triazopropionic acids, the latter determinations showingthat the effect on the strength of acetic acid produced by theintroduction of a triazo-group is less than that due to a bromine atombut greater than that due to an iodine atom.s6Bistriazo-compounds were also prepared : 1 : 2-bistriazoethane,N,*CH,*CH,*N,, and ethyl bistriazoacetate, CH(N,),*CO,*C,H,, thelatter being distilled and analysed in spite of its explosive properties.1 : 1-Bistriazoethane, CH3*CH(N,),, which was produced by thegeneral method from ethylidene dichloride and sodium azide, could notbe distilled even under greatly reduced pressure, owing to the violencewith which it explodes a t temperatures below 50".a-Triazopropionic acid, which is a racemic compound, mas resolvedby means of brucine, and the hvorotatory component reduced tod-alanine.57Ethyl diazoacetate, first discovered by Curtius, gives rise to a com-plicated series of transformation products under the influence of alkalis.A tabulated summary of some of these derivatives was given in lastyear's Report (p.158). Among the points studied since this tablewas published is the action of hydrlzziue on ethyl diazoacetate andbisdiazoacetate and their imides.Triazoacetylhydrazide (I) is produced either by the action ofhydrazine hydrate on diazoacetamide or by treating ethyl diazoacetatewith anhydrous hydrazine ; its constitution is demonstrated by thefollowing synthesis :CH,I*CO,Et Asf'3 N,*CH,*CO,Et 22 N,*CH,*CO*NH*NH,.(1.1The six-membered dihydrotetrazine ring in ethyl bisdiazoacetate (I),N,* co c<;;;,N>c-co*N3.(V.18(i J.C. Philip, Trans., 1908, 93, 918, 925.yi M. 0. Forster and H. E:. Fierz, ibid., 72, 669, 1070, 1174, 1859, 186596 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.is not affected by hydrazine, the action of which is effective only onthe carbethoxy-groups, thus giving rise to ethyl bisdiazoacetatehydrazido (11) and bisdiazoacetic acid dihydrazide (111).These hydrazides are converted respectively by nitrous acid intoethyl tetrazinedicarboxylate azide (IV) and tetrazinedicarboxylbisazide (V).88The action of cold concentrated aqueous potassium hydroxide onethyl diazoacetate leads to the production of tripotassium +-diazo-acetate (I), a compound which is transformed by this alkali at 100'into potassium bisdiazoacetate :This tripotassium salt corresponds with the amide (11) produced bythe action of liquid ammonia on ethyl diazoacetate.On treatmentwith alkali nitrite and acetic acid, this potassium salt yields potassiumnitrosodihydrotetrazinecarboxylate (III), from which reduction withhydrogen sulphide leads to dihydrotetrazinecarboxylic acid (IV), a sub-stance which, even at 60°, loses carbon dioxide and passes intoN-l-amino-1 : 3 : 4-triazole (V).*gCO,K* c < ~ ~ ~ ~ > o N o ----, CO,KG<~L.G~>CH -+8-fiT (111.) (IV. 1CH C H\/NI*=2(V. 1The compound obtained by the action of potassium ethoxide on ethyldiazoacetate is not, as was formerly supposed by Hantzsch andLehmann:o a potassium ethyl isodiazoacetate, C02Et*C<xg, but a$-diazoacetate derivative (potassium ethyl $-diazoacetate) containinga molecule of potassium ethoxide :CO,E t C<g',Ng>CK C02Et,C2H, OK.The corresponding sodium derivative is known, and both substanceshave all the properties of t,b-diazoacetates (CN-dihydro-1 : 2 : 4 : 5-tetr-azine-3 : 6-dicarboxylates).glT. Curtius and E.Rimele, Ber., 1908, 41, 3108 ; A., i, 921.89 Ernst Muller, ibid., 3116 ; A., i, 922.yo Ber., 1901, 341, 2506 ; A., 1901, i, 678.y1 T. Curtius, A. Darapsky, and Ernst Muller, ibid., 1908 41, 3140 ; A., i, 923ORGANIC CHEMISTRY. 97Further details of the transformations of ethyl diazoacetate will befound in a recently-published &sum6 of the ~ o r k . 9 ~The Terpene Group.Great activity has been shown in the investigation of the terpenes andallied substances during t b past year, and important progress hasbeen made in the establishment of the constitution of several membersof the group.The great services rendered to this branch of chemistry,as to so many others, by the discovery of Grignard's reaction areobvious on an examination of the papers dealing with terpenesyntheses. I t is in connexion with the study of the terpenes, also,that the optical method, the determination of the refractive index anddispersion, has proved of the greatest value. Several cases of apparentexception to the regularities in the relation of refractive index toconstitution have been removed recently, as the result of a morecomplete purification of the substances supposed to be anomalous.There still remain some marked apparent exceptions, some of whichmay be due to.unnoticed isomerisation during the preparation. Suchisomeric changes, usually involving the shift of a double linking, arefrequent. I n a recent instance, the process of heating with quinolineand quinoline hydriodide, a procedure sometimes adopted, is found tocause the rearrangement of methylenecyclohexane to methyl-Al-cyclo-hexene, the double linking changing its position : 93The synthesis of carvestrene94 has now been supplemented by thesynthesis of an isomeride, also of the na-menthadiene series, for whichthe name isocarvestrene is proposed, the two terpenes differing only inthe position of the double bond i n the ring.95 Starting with ethylcyclohexanone-2 : 4-dicarboxylate (I), methylation gives ethyl l-methyl-cyclohexan-6-one-1 : 3-dicarboxylate (II), which loses a carbethoxylgroup on hydrolysis, yielding l-methylcycZohexan-6-one-3-carboxylicacid (111).By reduction to the hydroxy -acid, treatment with hydrogen bromide,and subsequent removal of hydrogen bromide by diethylaniline, an* Ber., 1908, 41, 3161 ; A., i, 924.93 A.E. Faworsky and I. Borgmann, Ber., 1907, 40, 4863; A., i, 15.94 Ann. Report, 1907, 129.95 K. Fisher and W. H. Perkin, jun., Trans., 1908, 93, 1876.REP.-VOL. V. 98 ANNUAL REPOKTS ON THE PROGRESS OF CHEMISTRY.H C0,Et Me C0,Et H Me\/ \/ \/H Hd\/ C0,Et(1.)H2(111.)*2(11.1acid is obtained which is shown to be 1 -methyl-A6-cycZohexene-3-carboxylic acid (IV).Magnesium methyl iodide converts the un-saturated acid into A6-m-menthenol (V), the terpineol of the series,from which isocarvestrene (VI) is obtained by removing water withmagnesium methyl iodide.H2Me Me MeThe new terpene is found to possess somewhat remarkableproperties, the high refraction and dispersion, and the formation of adibromide instead of a tetrabromide, causing it to resemble a terpenewith conjugated double linkings, a constitution which appears to beexcluded by the conditions of the synthesis.The important synthesis of terpineol\ by W. H. Perkin, jun., in1904,96 has been completed by the production of the two activeterpineols, the original product having been inactive. This has beeneffected by the resolution of &I-1 -methyl-A3-cycZohexene-4-carboxylicacid,by crystallisation of its strychnine and brucine salts.97Another interesting synthesis from the same laboratory has beenthat of a terpineol, terpin, and terpene containing a five-memberedring.Qs Ethyl cyclopentanone-3-carboxylate (I) reacts with magnesiummethyl iodide, forming 1 -methyl- 3-isopropenol-A5-cycZopen tene (11)the terpineol of the five-carbon series, which yields the correspondingterpin (111) with acids :co CMe OH-CMe/\ /\VH VH2 p z/\p 2 p 2CH,-CH-CO,Et CH2-CH*CMe2*OH CH,-C K*CMe,*OH(1.) (TI.) (111.)96 Ann.Report, 1904, 116.97 K. Fisher and W. H, Perkin, jun., Trans., 1908, 93, 1871.98 W. N. Haworth and W. H. Perkin, jun., Trans., 1908, 93, 573ORGANIC CHEMISTRY.99A second method of synthesis leads equally to members of thisseries. Ethyl 2 -met hylcyclopentan- 2 -one- 3-dicarboxylate (IV) maybe broken down by hydrolysis to pentane-pyc- tricarboxylic acid (V),the ethyl ester' of which condenses under the influence of sodium,forming ethyl 2-met8hylcycZopentanone-3 : 5-dicarboxylate (VI). Byreduction and addition and subsequent removal of hydrogen bromide, aCHMe*CO,Hco I co CH*CO,HI A(1V.j (V. 1 (VI. )CC),Et YH QH Me /\ ?€I2 ?Me*CO,Et ?HaCH,-CH*CO,Et CYH,*CO,H CH,-CH*CO,Etmixture of unsaturated esters is obtained, from which ethyl l-methyl-A4-cycZopentene-2-carboxylate (VII) has been isolated by an ingeniousprocess. Magnesium methyl iodide converts it into the terpineol (VIII)The corresponding terpene, l-methyl-2-isopropenyl-A4-cycZopenteneCHMe CHMe CHMe/\ /\ /AfiH yH*C'O,Et g€€ QH*CMe,*OH EH FH-CMe:CH,CH--CH, CH-CH, CH--CK,(VII.) (VIII. ) (1X.j(IX) is obtained from this by dehydration [with succinic anhydride.This hydrocarbon is possibly identical with that obtained by Semrnlerfrom sabina ketone.It is only possible to make a selection from the very numeroilspapers dealing with terpene chemistry. Terpinene, although rarelypresent in natural products, is of interest from the fact that it isfrequently produced by the action of acids on other terpenes, aridtherefore appears to be one of the most stable members of the group.It has been previously suggested that terpinene is identical withcarvenene, and this is confirmed by the conversion of carvenone (I) byway of the oxime into 2-amino-A3-menthene (11), distillation of thephosphate of the latter yields a pure A' '3-menthadiene (carvenene)(111), which, from its conversion into terpinene nitrosite, appears to beidentical with ter~inene.9~ Whilst fornier preparations of terpineneMe Me Me(1.1 (11.1 (111.)have failed to show the optical exaltation corresponding with the con-99 C. D. Harries and R. Majima, Ber., 1908, 41, 2516 ; A., i, 733.H 100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.jugated double linkings, i t is exhibited by the carvenene prepared bythis method.1 A study of the oxidation products of a- and P-terpinenealso leads to the conclusion that the hydrocarbon yielding the nitrositeis A" "menthadiene (a-terpinene).2The new terpene obtained from Cyprus origanum oil, and describedas origanene, has also the properties of A1'3-p-menthadiene, and showsoptical exaltation.Its properties agree fairly well with those ofcarvenene or a-terpinene.32-Methylcarvenene has been prepared by the action of magnesiummethyl iodide on carvenone.*The first synthesis of a-phellandrene from a substance containing asmaller number of carbon atoms has been accomplished by treating~sopropyl-A2-cycZohexen-4-one, prepared by the isomerisation of sabinaketone, with magnesium methyl iodide.5Turning now to bicyclic terpenes, a comparative study of the actionof hydration in breaking down bridged linkings has been made byWallach.6 The addition is very commonly accompanied by molecularrearrangement, sabinene and pinene hydrates, for instance, probablyfirst losing water, which is then added on in a different position,yielding terpinene-4-01 and a-terpineol respectively.The relativebehaviour of three- and four-atom rings on hydration confirmsPerkin's conclusion, derived from experiments of a different kind,that the relative stability of cyclopropane and cyclobutane ringsdepends much more on the nature and position of the attached groupsthan on the number of carbon atoms in the ring.Of the two possible formula for umbellulone proposed by Tutin (I)and by Semmler (11) respectively, the first is preferred, since theCH,-CH-GOCHRle,I CH,*C-- coI/ I CH--CMe=CHsecond would require that tetrahydroumbellulone should be menthone,whereas the mixture of stereoisomeric tetrahydro-derivatives actuallyobtainediis unlike menthone.1 J.W. Briihl, Ber., 1908, 41, 3712; A., ii, 1002.2 0. Wallach, Annalen, 1908, 362, 261, 285; A., i, 811, 813 ; Semmler,however (Rer., 1908, 41, 4474 ; A., 1909, i, 110), dissents from this conclusion, andiuaintains the A1:4 constitution for terpinene.8 S. S. Pickles, Trans., 1908, 93, 862.4 H. Rupe and F. Ernmerich Ber., 1908, 41, 1750 ; A., i, 556.6 Artnalen, 1908, 360, 82; A., i, 429.7 F, Tutin, Trans., 1908, 93, 252 j F. W. Semmler, Ber., 1908, 41, 3988 ; A.,0. Wallach, Annalen, 1908, 359, 266 ; A., i, 424.1909, i, 38ORGANIC CHEMISTRY. 101Santene has received the constitution (I) on the ground that gentleOxidation with permanganate yields a glycol (11), further oxidationgiving a diketone (111), the constitution of which is proved by itsoxidation to trans-yclopentanedicarboxylic acid.8CMe*CH-CH, OH- CMe- CH-CH, I\ie*CO*CH-CH,I I IMe*COdH-CH,(1.1 (11.1 (111.)A further attempt has been made to elucidate the nature of theisomerism of the two modifications of isonitrosocamphor by the studyof the action of diaz~rnethane.~ This reagent converts the unstableinto the stable modification, and the latter into the AT-ether, which ispossibly C,H,,< C:NMe:o. I The presence of a nitroso-group is im-probable, from the absence oE a blue or green colour and of theLiebermann reaction, and the production of the N-ether is in betteragreement with the formulation of isonitrosocamphor ascoSeveral investigations have been directed to the establishment ofthe constitution of fenchone.Three formula have been proposed, duerespectively t o Wallach (I), Semmler (11), and Glover (111). Of these,CH,*CH-CHMe CH,*CH--C!Me, CH,*CH,-CMeCH,.CH-CO CH,*hMe* CO CH,*C'H--CO(1.1 (11.) (111.)the first formula is very similar to that of a-methylcamphor, and thesecond to that of aa-dimethylcamphor. Both are open to the objectionthat fenchone behaves very differently from camphor in many of itsreactions. The oxidation of fenchene and fenchone lo leads to inde-cisive resuIts, it being difficult to reconcile the reactions observed witheither of the proposed formuls.The production of dihydrofencholen-I 4 I I CMe, I CMe2 I I GI12 I I Iamide, NH2*Co*?Me* CH2>CH*CHMe,, by the action of sodamideCH,-CH,on fenchone, and the formation of apofenchene,fiMeoCH2>CH#CHMe, CH--CH,(the constitution of which is established by its oxidation through a8 F. W. Semmler and I(. Bartelt, Ber., 1908, 41, 385, 866 ; A , , i, 195, 355.M. 0. Forster and IT. Holmes, Trans., 1908, 93, 242.lo 0. Wallach, Annalen, 1908, 362, 174 ; A., i, 809102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ketonic acid t o P-isopropylglutaric acid) from the latter, is consideredto favour Semrnler’s formula.aa-Dimethylcamphor (111) should be capable of preparation fromdimethylcampholide (I) by addition of potassium cyanide, hydrolysis todimethylhomocamphoric acid (II), and distillation of the calcium salt.A comparison of this compound with fenchone should then be ofconsiderable interest.It mas found, however,12 that although theCH,*CH-CMe, CH, *C Ha CMe,*CO,H CH, CH-CMe,CH,*CMe --CO CH,*CMe*CO,H CH,*CMe-GO(1. ) (11.1 (111.)required dimethylcampholide was readily obtained by the action ofmagnesium methyl iodide on camphoric anhydride, it mas impossiblet o cause combination with potassium cyanide, isomerisation to anunsaturated acid always taking place.The preparation of a number of derivatives of a-methylcamphor hasshown 13 that this compound is entirely similar to camphor, and con-sequently unlike fenchone. or-Methylcamphor forms bromo- andsulpho-derivatives closely resembling those of camphor.The synthesis of an isomeride of /3-pinene from nopinone, describedin last year’s Report (p.132), has been modified, and decomposition ofthe unsaturated acid is now found to yield fenchene or P-pinene,according to the conditions of dehydration of the nopinolacetic acid,The fenchene is probably formed by intramolecular change of P-pinene.Since P-pinene yields bornyl chloride with hydrogen chloride, bothcamphor and camphene may be prepared from it, this being the firstsynthesis of camphor from a compound (nopinone) containing a smallernumber of carbon atoms.14A cyclooctadiene was obtained by Willstatter and Veraguth in 1905from the alkaloid $-pelletierine, and its ready polymerisationsuggested the presence of conjugated double linkings in the mole-cu3e.15 This compound derives its principal interest from the fact thatcaoutchouc is supposed to be a polymerised dimethyl derivative of thesame hydrocarbon.Since, however, the A1:5-members of this seriesalso polymerise readily, this constitution also becomes a possible one.An examination of the diozonide, which is hydrolysed by waterto succindialdehyde, proves that the double linkings are in the1 : 5-position : 16I I I I UMe, 1 >. I y e 2 I y e 2 I11 L. Bouveault and Levallois, Compt. rend., 1908, 146, 180 ; A., i, 193.l 2 G. Komppa, Ber., 1908, 41, 1039 ; A.: i, 352.l 3 W. H. Glover, Trans., 1908, 93, 1285.l4 0. Wallach, Aiznalcn, 1908, 363, 1 ; A., i, 997.19 Ann. Report, 1905, 121. C. D. Harries, Ber., 1908, 41, 671 ; A ., i, 254ORGANIC CHEMISTRY. 103QH,*CH:CH*$!H, -+ CH,*CH:CH' CH,The investigation ofFH,-CH-~H.~H, CH,*C'HO CHO-~H,--f I CH,*CH*CH*CH, CH,*CHO CHO*CH,'\/0,the polymerisation products showed that therewas no direct connexion between the constitution of the hydrocarbonand that of caoutchouc. The simplest polymeride, dicyclooctadiene,appears from its behaviour with ozone to have the constitution :~HDCH2*CH,*~-~H-CH,*CH,*QH,CH*CH,*CH,*CH CH,*CH,*CH=CH.Connected with the ethereal oils, although not a member of theterpene group, is elemicin, isolated by Semmler from elemi resin.17This is proved to be 3 : 4 : 5-trimethoxy-1-allylbenzene (I). Whendistilled over sodium, i t is converted into the isomeric propenylCH,-CH:CH, CH: CH-CH,/\ /\\/ OMd lOMe OMe(/OMeOMe(1.) (11.)OMederivative, isoelemicin (11).Permanganate oxidises it to 3 : 4 : 5-tri-methoxybenzoic acid. Sodium and alcohol reduce both elemicin andisoelemicin to 3 : 5-dimethoxy-1 -n-propylbenzene, the p-methoxyl groupbeing eliminated,CrystaZZine Liquids.The property of existing in a liquid phase, which exhibits certain ofthe optical properties of crystalline solids, for example, double refrac-tion, is possessed by many organic substances, and the relationshipwhich in all probability exists between their chemical constitutionand the development of this crystalline liquid condition is at presentunder investigation. .In p-methoxycinnamic acid, which exhibits this peculiarity, theproperty is probably due to the presence of the groupCH,*O*C,R,*CH:CR,for dianisyltetrylene, which consists of two of these radicles, stillretains the power of forming an anisotropic liquid.p-Methylamino-benzaldehydephenylhydrazone, CH,*NH*CBH,*CH:N*NH*C~H~, s-di-F. W. Qemmler, Eer., 1908, 41, 1768, 1918, 2183, 2556 ; A , i, 557, 558, 664,734104 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ethylbenzidine, C,H,*NH*C,H,*C,H,*NH*C,H,, and p-methoxy-cinnamaldazine,CH,*O* C6H,*CH :CH* CH:N*N: CH*C H: CH* C,H,*O*CH,,which likewise display this phenomenon, are either para-substitutedcompounds or possess long, straight chains.ls Cholesterol derivatives,which frequently exhibit the crystalline liquid condition, probablycontain an asymmetric group and a long, straight chain.The turbidity of many of these crystalline liquids is not due tosuspended impurities, emulsions, or inclusions of foreign substances,but is a natural consequence of the presence of differently situatedanisotropic, crystalline fragments. Moreover, perfectly clear crystalline liquids have now been prepared, some of which maintain theirtransparency in any position, whilst others are clear or turbidaccording to the incidence of the light.The chemical constitution of substances forming crystalline liquidphases warrants the view that a linear structure favours the develop-ment of the property, whilst a cruciform or many-branched configurationinhibits this condition.Para-substituted benzylidene-p-amino-a-alkylcinnamates having thefollowing general formula have been prepared and examined fromthis standpoint :para-x.C6H, * CHON C,H,*CH: CO,R.YThe tendency to develop the crystalline liquid condition reaches itsmaximum when an ethyl or a n-propyl group is introduced at R (theester radicle); it is also increased by the replacement of methoxyl atX (the para-substituent) by ethoxyl or phenyl. The lengthening ofthe side-chain Y in the order methyl, ethyl, and phenyl inhibits to anincreasing extent the property of exhibiting the liquid crystallinecondition. The property of circular polarisation is developed to aremarkable extent by the introduction of an active amyl group intoposition R.The ethyl p-azoalkylcinnamates and p-azoxyalkylcinnamates re-semble the foregoing azomethine derivatives in respect of thisproperty of assuming the crystalline liquid condition.19The simpler azoxy-derivatives (azoxybenzene, p-azoxyphenetole,the three isomeric azoxytoluenes, and azoxyanisoles) can also existin the anisotropic liquid condition, and it is stated that these modifi-cations differ from the ordinary varieties in certain chemical properties.Among other anomalous reactions, they give the Liebermann nitroso-coloration, and are not transformed into hydroxyazo-compounds.20l9 D.Vorlander, ibid., 2033 ; A., i, 641.2o T. Rotarski, zbid., 865 ; A., i, 374.T. Rotarski, Ber., 1908, 41, 1994 ; A . , i, 640ORGANIC CHEMISTRY. 105These differences are sufficiently remarkable to warrant a moreextended investigation.Optical Activity.In recent measurements of the optical activity of organic compounds,the theoretical connexion with the degree of asymmotry of the mole-cule, as expressed by Guye’s “ asymmetry product,” 21 has beenfrequently referred to and discussed, without, however, any verydefinite conclusions having been yet reached.A recent physicalinvestigation 22 leads to the conclusion that the variation in the valueof the expression with the temperature and the wave-length of thelight used must be taken into account. The author states that if asubstance containing a single asymmetric carbon atom could be found,the temperature of reversal of sign of which could be determined, ameans would be provided of testing the validity of the modified Guye’sequation, but this test has not yet been applied.The difficulty of finding any simple formula for the relation hasbeen further illustrated by the examination of a series of salts, all ofwhich contained p-bromophenyl, methyl, and allyl, the remaining groupbeing ethyl, n-propyl, isopropyl, or isoamyl.As in similar seriesexamined previously, no simple relation was dis~overed.~a Theinfluence of the constitution of the substituting groups may alsobe so great as to outweigh that of mass.24The influence of the introduction of unsaturated groups into themolecule has also been further studieda25 The alkaloid salts of anumber of acids were examined, and the rule that the change fromthe saturated to the ethylenic linking produces an increase in therotatory power was confirmed.The triple linking, however, maygive rise to a higher or a lower value in different cases, the directiondepending mainly on the asymmetric part of the molecule. Neithercould any rule be found for the comparative influence of cis- and trans-configurations. The presence of several unsaturated groups stillfurther increases the optical activity, the relative nearness of theunsaturated linkings having an important effect. The investigationwas extended to include sulphur derivatives in which the valency ofthe sulphur, and therefore the amount of its residual affinity, wasvariable. The progressively increasing unsatnration’ of the sulphurin the sulphone, R,SO,, the sulphoxide, R,SO, and the sulphide, R,S,is accompanied by a small increase in the rotation, but the conjugationAnn.Report, 1907, 178.23 E. Bose, Physikal. Zeitsch., 1908, 9, 860 ; A., 1909, ii, 2.23 H. 0. Jones and J. R, Hill, Trans., 1908, 93, 295.24 R. W. Everatt, ibid., 1225, 1789.T. P. Hilditch, ibid., 700, 1388, 1618106 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of two bivalent sulphur atoms in the disulphide, RSoSR, produces arelatively enormous effect. The results obtained with alkaloid saltsof aromatic sulphonic and sulphinic acids follow the same rule if thelatter are assumed to contain sexavalent, and not quadrivalent,sulphur, an assumption for which there is chemical evidence. If bothseries oE compounds contain sexavalent sulphur, the sulphonic acidswill be the less saturated, owing to hydroxyl, possessing some residualaffinity, replacing hydrogen : R*SO,*H -+ R*SO,*OH.No certain occurrence of optical activity has yet been observed ina compound in which the asymmetric carbon atom is not attached toother carbon atoms.Two compounds of very simple structure, chloro-sulphoncetic acid, SO,H*C€tCl*C!O,H, and chlorobromomethane-sulphonic acid, CHClBr*SO,H, one containing only two and theother only a single carbon atom, have been prepared and combinedwith various active bases, but without any resolution into opticalisomerides being obtained. If isomerism in such a case is possible,the separation of the isomerides is evidently a very difficult one.26The suggestion of van't Hoff, that enantiomorphous forms mayexist of compounds containing no asymmetric atom, but derivingtheir asymmetry from the general structure of the molecule, as inallene derivatives,a,>c:c:c<;,and that such isomerides should exhibit optical activity, is one ofgreat theoretical interest, which has not yet been put to an experi-mental test.An attempt to prepare allene derivatives of the above type,capable of combining with active acids or bases, having proved un-successful, compounds have been selected in which symmetrical closedrings replace the double linkings, of which 1 -methylcycZohexylidene-4-acetic acid,Me ~ > c < ~ ~ : ~ ~ > c : c < , " , H92is a typical example. The synthesis of this acid27 has proved to be adifficult problem, and the product obtained is impure; the test ofresolution has therefore not yet been applied.The problem is ofsuch importance for stereochemical theory that it seems advisableto mention the investigation in this place, in spite of its incompletestate.The problem of . a complete asymmetric synthesis, that is, the arti-ficial production of an optically active substance without the interven-tion of an optically active reagent, has been frequently attacked from26 W. J. Pope and J. Read, Trans., 1908, 93, 794.27. W. H. Perkin, jun,, and W. J. Pope, ihid., 1075ORGANIC CHEMISTRY. 107the physical as well as from the chemical side. The use of circularlypolarised light has often been suggested and employed for this pur-pose, so far with entirely negative results.I n the latest attempt inthis direction 28 the authors point out some of the conditions whichmust be fulfilled in order that such an attempt may have a prospectof success. The reaction by which the substance is produced must beone which is brought about by light. A reaction which proceedsindependently of illumination is not likely to be affected by polarisa-tion of the light falling on the reacting substance. A suitable reactionwas found in the removal of carbon dioxide from substituted succinic,malonic, and cyanoacetic acids by light in the presence of uraniumsalts, as, for instance :Me>c<g;2H Et -+ ",> c<"$"'CMeCl* CO,H E>c<H Me CMeCl*CO,H -+C1>C<Co,RNo optical activity of the resulting product was, however, observedwhen the light was polarised before entering the solution, and theattempt is therefore so far unsuccessful.A remarkable series of observations is recorded with reference tothe separation of active components from a dZ-mixture.29 A super-saturated solution containing, for instance, dZ-sodium ammoniumtartrate may be caused t o crystallise by the addition of a crystal ofthe active modification of a tartrate isomorphous or isodimorphouswith the dissolved salt, and the crystals separating will have the samesign as the crystal used for inoculation, !This is not surprising whenthe similarity in crystalline structure is taken into account. It isfurther stated, however, that it is not necessary that the crystal usedfor inoculation should be optically active.The experiments wereprincipally made with glycine, and when added to a supersaturatedsolution of dl-asparagine, deposition of active asparagine was broughtabout. It was impossible to predict whether the d- or the Z-formwould separate, but the same crystal of glycine always brought aboutcrystallisation of the same isomeride. It is suggested that glycinecrystals are hemihedral. If these experiments should be confirmed,and are not found to be due t o the presence of optically activesubstances in the glycine employed, a great advance will have beenmade in the artificial production of active compounds by an asymmetricsynthesis.Another line of attack which has been adopted by several workers,38 F. I-Ienlc and H. Haakh, Ber., 1908, 41, 4261 ; A., 1909, i, 6.29 I.Ostromisslensky, ibid., 3035 ; A . , ii, 913108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.is that of preparing an asymmetric compound in an active solvent,the molecules of which might reasonably be expected to exert adirecting influence on the course of the reaction. An attempt of thiskind has now been made in the nitrogen series, but without success.Benzylmethylaniline was combined with ally1 iodide in a number ofoptically active solvents, such as d-limonene, Z-menthol, and Z-menthylchloromethyl ether, but in no case was an active ammonium iodideobtained.30I n the continued series of investigations of the influence of solventson the optical activity of ethyl tartrate, Patterson and his co-workershave examined a large number of halogen and nitro-compounds.31Amongst the halogenated solvents, such as alkyl iodides, chloroform,acetylene tetrabromide, etc., many exceptions were again found to therule that specific rotation varies inversely with solution volume.Witharomatic halogen derivatives, well-marked minima of rotation wereobserved at certain concentrations. The changes of rotation withtemper'ature were also examined, and solutions in a-bromonaphthalenewere found to have a maximum rotation at 94", the case resemblingthat of dilute solutions of alkyl tartrates in water, the rotation-temperature curve of which also passes through a maximum. A widerrange of activity was observed when aromatic nitro-compounds wereused as solvents, the specific rotation at infinite dilution in a-nifro-naphthalene being about + 65", and in s-trinitrobenzene about - 30'.The relation between the maximum rotation and the temperature atwhich it occurs is fairly independent of the nature of the solvent andof the concentration.As in the problem of the relation of activityt o asymmetry, it is evident that in spite of the vast quantity ofexperimental material that has been accumulated, the completetheoretical explanation is far from having been attained.Two forms of asymmetry have been observed in nitrogen compounds,the first, in substances containing tervalent nitrogen doubly linkedwith carbon or nitrogen, as in oximes and diazo-compounds; thesecond, in substances containing quinquevalent nitrogen, So far,activity has only been observed in the latter class when the five sub-stituting groups are all different, although four different groups shouldsuffice to produce asymmetry.A new class of active substances hasnow been found, in which two valencies of the nitrogen atom are unitedto the same, or similar, atoms. Methylethylaniline oxide, for example,has been resolved into two active components by conversion into the30 E. Wedekind and 0. Wedekind, Ber., 1908, 41, 456 ; A., i, 255.31 T. S. Patterson and D. Thoinson, Trans., 1908, 93, 355 ; T. S. Patterson andD. P. McDonald, ibid., 936; T. S, Patterson, ihid., 1836ORGANIC CHEMISTRY. 109d-camphorsulphonate.very weak base, must containThe solution of the active oxide, which is ain either case, the number of different groups united with the nitrogenatom is only four. If the compound present in the solution of the basehas the second formula, the positions of the two hydroxyls cannot beidentical, since the addition of hydrochloric acid produces a salt havingthe same activity as the base. It is concluded that four of thevalencies of a quinquevalent nitrogen atom are directed, like those ofa carbon atom, to the angles of a tetrahedron, the fifth (ionisable)valency being mobile.Isomerism would then occur whenever thegroups attached by the four fixed valencies were different.32Active piperidine derivative’s having a large substituent in position2, and an alkyl attached to the nitrogen atom, have been found to yieldtwo stereoisomeric quaternary salts with alkyl haloids, only a singleproduct being obtained when the substituting group in position 3 isabsent or small.This has been further confirmed by the examinationof U- and P-pipecoline derivatives, benzyl haloids being added to theZ-bases.Turning now from the production of active substances to theirresolution and racemisation, the preparation of the two active forms ofbenzoin has now been accomplished. Z-Mandelic acid is converted intothe amide, and this is combined with magnesium phenyl bromide,yielding Z-benzoin. The d-isomeride is prepared in a similar way.With the exception of laevulose, no keto-alcohol had previously beenresolved into itts optically active c0mponents.3~The autoracemisation of active ammonium salts in solution has beenthe subject of but it now appears certain from cryoscopicmeasurements and from comparative determinations of the velocity ofdissociation and of change in rotation, that the observed alteration inrotation is due to the breaking up of the ammonium salt in solutioainto tertiary amine and alkyl halide.A case of partial racemisation has been observed in the hydrogentartrate of hydroquinaldine.36The Walden inversion has been the subject of several investigations.33 11.Schaltz, Cibid., 2005 ; A., i, 678.a4 A. McKenzie and H. Wren, Trans., 1908, 93, 309.35 E. Wedekind, 0. Wedeliind, and F. Yaschke, Ber., 1908, 41, 1029, 2659 ; A.,36 A. Ladenburg and W. Hemnann, ibid., 966 ; A., i, 364.I n neither case were optical isomerides obtained.33J. Meisenheimer, Ber., 1908, 41, 3966 ; A., 1909, i, 20.i, 334, 722 ; 8.von Halban, ibid., 2417 ; A., i, 627110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The replacement of halogen by hydroxyl or methoxyl in phenylchloro-acetic acid has been examined from this point of view, the resultsbeing expressed in the two following schemes :1.11.d-OH GHPh*CO,H4I NaoHd-CHClPh*CQ,HPCl5$? E-CHClPh*CO,HI AgaOPClS +NILOH ?$ I-OH*CHPh*CO,HAg20AgaO and Me1d-OH*CHPh*CO,H -- 3 d-OMe*CHPh*CO,HPI5MeONaZ-CHC1Ph*C02H -3 I-OMe*CHPh*CO,HIt appears from this that in the interconversion of the mandelic acids,sodium hydroxide behaves abnormally and silver oxide n0rmally.3~E. Fischer has also continued his investigations on the samesubject,38 and finds that valine (a-aminoisovaleric acid) remainsoptically unchanged after conversion into the bromo-fatty acid andback again into the amino-compound. It is suspected, however, thatthis result is due rather to a double Walden inversion than to itsabsence.This exceptional behaviour is attributed to the influence ofthe isopropyl group. Active aminophenylacetic acid is racemised sorapidly by nitrosyl bromide or nitrous acid that pure active productscould not be obtained.It is oniy possible t o refer to a few more papers dealing with stereo-isomerism. A method of determining the configuration of a-dioximesis furnished by the fact that of the possible isomerides, only the syn-modification has the property of forming complex metallic d i o ~ i r n i n e s .~ ~The method has been tested in a number of cases, arid has beenapplied to several a-dioximes of previously unknown configuration.No marked difference is to be found between the dielectric constantsof d-, L, and i-modifications of asymmetric compounds. Ethylracemate, however, has a much greater absorptive power for electricwaves than the tartrate, and, since hydroxylic groups are theprincipal cause of such absorption, this suggests that the hydroxyls aremainly concerned in the formation of the racemic compound.40The viscosity of a solution of a racemic salt is always less than thaty7 A. McKenzie and G. W. Clough, Tmns., 1908, 93, 811.3a E. Fischer and H. Scheibler, Bey., 1908, 41, 889, 2891 ; A., i, 324, 857 ;3g L.Tschugaeff, ibid., 1678 : A., i, 554. * A. W. Stewart, Trans., 1908, 93, 1059.E. Fischer and 0. Weichhold, ibid., 1286 ; A., i, 419ORGAXIC CHEMISTRY. 111of the active components, but the difference is very small. Thetransition point of the racemate also appears as a break in thetemperature-viscosity curve.41Some Reactions o j the Cyclic Hydrocarbons and theiv Derivatives.1. Aromatic from Hydroaromatic Compounds. --The conversion ofaromatic substances into hydroaromatic derivatives by hydrogen anda catalyst has already been mentioned. An interesting case of theconverse change has recently been worked out, in which phenolhas been produced from cyclohexanol in such a way that the inter-mediate products could be isolated, showing the gradual transitionfrom the saturated to the aromatic ring.cycZoHexanone, obtained by the oxidising action of bromine orchlorine from the saturated alcohol, was brominated to 1 -bromocycZo-hexanone. The elimination of hydrogen bromide led to h2-cyclo-hexenone ; addition of bromine t o this substance, followed by removalof hydrogen bromide from the resulting dibromide, finally gave phenol :Ethyl cyclohexane-2-carboxylate is converted into salicylic acid by aprecisely similar series of changes.422. Oxidation of Aromatic Substances.-Although the aromatichydrocarbons (benzene, naphthalene, etc.) are not themselves oxidisedto definite products by chromyl chloride yet, the correspondingaldehydes are readily obtained with this oxidising agent from the m-and p-nitrotoluenes and the three isomeric chlorotoluenes.I n asimilar manner, diphenylmethape and triphenylmethane are convertedquantitatively into benzophenone and triphenylcarbinol respectively.43Caro’s acid has been successfullyapplied to the preparation of tertiaryamine oxides ; tetramethyldiaminodiphenylmethane and hexamethyl-triaminotriphenylmethane having been thus converted into tetra-methyldiaminodiphenylmethane dioxide (I) and hexamethyltriamino-triphenylmethane trioxide (11) respectively.(1.1 (11;)41 A. E. Dunstan and F. B. Thole, Tmns., 1908, 93, 1815.la A. Kotz and C. Gotz, Annulen, 1907, 358, 183 ; A., i, 173.43 H. D. Law and F. M. Perkin, Trans., 1908, 93, 1633112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The reactions of these amine oxides are of interest ; sulphur dioxideand nitrous acid convert them respectively into the sulphonic acids andnitro-derivatives of the original tertiary bases.In these reactions theoxygen atoms of the di- and tri-oxides become involved, and the sub-stituents take up ortho-positions with respect to the nitrogen atoms.44The oxidation of acetyl-p-phenylenediamine by Caro’s acid results inthe formation of p-nitrosoacetanilide (green plates, m. p. 1 7 5 O ) , whichis transformed by water into its colourless, bimolecular polymeride(m. p. 181°).45The technically important conversion of p-nitrotoluene and itsderivatives into stilbene compounds has been further investigated, theresults showing that the following scheme of condensation in two stages,accompanied a t each stage by aerial oxidation, furnishes an explanationwhich is generally true of these condensations.condensation1st stage2CH3*CGH4*N02 -- 3$lH,*C,H4*N02 condensation EH*C,H,*NOCH,*C6H4*N0 211dstage CH*C H *NO __+ a 4$oxidation j,oxidatiuny3,*C6H4*N0, EH*C,H,* NO2CH2*C,H4*N0, CH*C6H,-N024-Ni tro-o-xylene and 4-nitro -2 -met hoxy + duene with methyl -alcoholicpotash and aerial oxidation gave chieflj 4 : 4’-dinitro-2 : 2’-dimethyl-stilbene and 4 : 4‘-dinitro-2 : 2’-metboxystilbene.Similar changesoccurred with 4-nitro-o-toluic acid and 2 : 4-dinitrotoluene, but in theformer case sodium hypochlorite, and in the latter, iodine wereemployed as oxidising agents.4G3. Reduction of Aromatic iVitro-conLiuozcnds.-A new phase in thereduction of nitro-groups has been observed by G.Heller andA. S o ~ r l i s , ~ ~ who also correct an earlier statement of Bamberger’s,4*that his so-called ‘‘ agnotobenzaldehyde ” has the formulaCOH* C,H,*N(OH)* O=N(OH)*C,H,*COH.This substance is really a molecular compound of o-nitrobemaldehydeand o-hydroxylaminobenzaldehyde,COH~C,H,*N0,,COH*C6H,*NH OH.They find, however, that the reduction of o-nitromnndelonitrile withE. Bamberger and L. Rudolf, Ber., 1908, 41, 3290 ; A . , i, 1011.J5 J. C:Cain, Trans., 1908, 93, 686.46 4. G. Green and J. Baddiley, ibid., 1721.47 Ber., 1908, 41, 373 ; A., i, 208.48 Ibid., 1906, 39, 4252; A., 1907, i, 163ORGANIC CHEMISTRY. 113zinc dust leads to the formation of a molecular compound of hydroxyl-aminomandelonitrile and dihydroxylaminomandelonitrile,CN*CH(OH)*C,H,*NH*OH,CN *CH(OH)*C,H,*N(OH),.This product on treatment with phenylhydraxine yields hydroxy-isatinphenylhydrazone and the a- and /3-phenylhydrazones of isatin.The reduction of nitro-compounds by alcoholic ammonium sulphide,which was first practised by Zinin in 1842, has been further developedin recent years.I n 1902 and subsequently, J. B. Cohen and othersshowed that hydroxylamino-derivatives were produced by the partialreduction of trinitrobenzene and trinitrotoluene with hydrogensulphide in the presence of a small amount of ammonia. They alsofound that chloronitro-compounds and alkyl dinitrobenzoates likewisegave hydroxylamines under similar condition^.^^ The fact that thischange, R*NO, -+ R*NH*OH, occurs generally, has been furtherdemonstrated by reducing the simpler nitro-compounds with alcoholicammonium sulphide in the cold, when excellent yields of the correspond-ing arylhydroxylamines were obtained.For example, a-nitronaphtha-lene gives a-naphthylhydroxylamine, from which a-nitrosonaphthaleneis easily produced by oxidation with silver oxide or lead peroxidein anhydrous solvents.50It has generally been assumed that the azoxy-compounds formedduring reduction by a condensation of the nitroso- and hydroxylamino-derivatives can only arise in neutral or alkaline solutions. But incertain cases this condensation may occur even in the presence ofmineral acids. The reduction of certain substituted nitro- anddinitro-compounds has been systematically examined, the resultsshowing that (1) condensation and reduction .of the inter-mediate nitroso- and hydroxylamino-derivatives both proceed at ameasurable rate whether the solution be acid, neutral, or alkaline ; (2)condensation is induced by the presence of tervalent nitrogen in thefree arylhydroxylamine, the quinquevalent nitrogen of the hydroxyl-amine salt being incapable of condensation.514. Pormation of Aromatic Hydroxylic Compounds.--In practice theintroduction of hydroxyl into the nucleus of an aromatic hydrocarbonrequires several operations, although small amounts of nitratedphenols are produced during many nitrations.According to a recentpatent, a mixture of benzene, strong nitric acid, and mercuric nitrategives a fairly good yield of picric acid, together with smaller amountsof nitrobenzene and o-nitrophenol.52The nitration process may be divided into two phases, in the second49 Trans., 1902, 81, 26 ; 1905, 87, 1257.5o R.Willstatter and H. Kubli, Ber., 1908, 41, 1936 ; A . i, 522.59 B. k’liirscheim and T. Simon, Tram., 1908, 93, 1463.51 R. Wolffenstein and 0. Boters, D.R.-P. 194883 ; A , , i, 629.REP.-VOL. V. 114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of which water is usually eliminated from the additive compoundformed in the initial phase : -’” ‘E” nitro-compound.\ €3 C*NO,/ NO,‘<OH--3 I \CHC<HThe alternative elimination of nitrous acid leads to the productionof phenolic compounds.The direct introduction of hydroxyl groups into the anthracenemolecule has been effected, and alizarin, free from by-products, maybe produced by heating anthraquinone with potassium chlorate andaqueous alkali hydroxide at 200°.53Similarly, anthrarufin (1 : 5-dihydro~yant~hraquinone) and chrysazin(1 : S-dihydroxyanthraquinone) yield respectively the 1 : 2 : 5- and1 : 2 : 8-trihydroxyanthraquinones when they are heated at 180-185Owith sodium nitrate and aqueous alkalis, a mixture of potassium andsodium hydroxides giving the best result.54Ring Pownation.The general tendency which undoubtedly exists for the formationof five- or six-membered rings in preference to those containing feweror more components, is usually explained in terms of von Baeyer’sstrain hypothesis, to which reference was made in last year’s Report(p.138). The new cases of ring formation observed during the pastyear furnish further confirmation of the validity of this general-isation.A striking illustration of the way in which the above tendencyaffects the properties of straight-chain compounds is afforded by astudy of the aminoketones having the general formulaC,H,*CO*[CH,],*NH,.A general method has been devised for preparing these substances,which consists in converting the phthalimino-aliphatic acids into theirchlorides, and then condensing these with benzene in the presence ofaluminium chloride : 55CO,H* [CH,],*N:C,H,O, -+ COC1*[CH27,*N:C,T~,0:, -+C,~~*CO*[CH2~2*,~:C,H40, -+ C,€15*CO*[CH,]z*NH, (I).Acid hydrolysis of the ketone leads to fission a t the double linking,63 D.R.-P.116526 ; A., i, 191.64 D.R.-P. 196980 and 195028 ; A., i, 807.65 S. Gabriel, Ber., 1907, 40, 2649 ; 1908, 41, 1127 ; A., 1907, i, 625 ; 1908, i,464ORGANIC CHEMISTRY. 115when phthalic acid and the salt of the aminoketone (I) are set free.It was at once seen that the stability of these compounds variedconsiderably with the value of x. The a-aminoketones correspondingwith x = 1 are only known in the form of their salts. When liberatedtherefrom, they undergo simultaneously condensation and oxidation, sothat a six-membered pyrazine ring is produced.N J 3 2 N\/NH, NThe P-aminoketones, such as diacetoneamine,CH,*CO*CH,*C(CH,),*NH,,are stable, and can be isolated without showing any tendency toundergo cyclic condensation into four- or eight-membered rings.They-aminoketones are so unstable that even in the form of theirhydrochlorides, condensation occurs with the production of a five-membered ring ; thus phenyl y-aminopropyl ketone gives rise t o2-phenylpgrroline :The 6-aminoketones are as unstable as the y-compounds. I npreparing one of these, the following series of operations mas carriedout :C,H,O,:N* [CH,],*CH( CO,*C,H,), -% C8H402: N*[CH2],* C0,H z?(C6H6 A1C13) C,H,O,:N*[ CH, J,*COCI --+- C8H402 :N* [CH,],*CO*C,H,.Hydrolysis of the final product, &phthaliminovalerophenone, gaverise, not to &aminovalerophenone, but to %phenyltetrahydropyridine,the six-membered cyclic condensation product :C,H,* F==N---CH,CH,-CH,-CH, --3 CH,*CH,*CH,'C,H5*7:0 H,N*FH, IThe eaminoketones, for example, eaminocaprophenone, which mightgive rise to seven-membered rings, are quite stable under conditionsin which the y- and 6-aminoketones condense to pyrrole and pyridinederivatives respectively.56The stabiIity of P-bubstitnted ketones disappears in the presence ofa reagent capable of condensing so as to form a five-membered ring.Methyl P-chloroethyl ketone condenses in this way with hydroxyl-amine, phenylhydrazine, or any of the reagents used in detectingcarbonyl oxygen.6G S.Gabriel arid J. Colman, Ber., 1908, 41, 2010, 2014; A., i, 648, 649.1 116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.An isooxazoline, N< CH*(?H2 is produced with hydroxylamine, 0 --C*CH,’whilst hydrazine and phenyl hydrazine yield pyrazolines,67N :CH* FH2XN-- C* CH,.A methyl group situated in an aromatic nucleus generally preservesits inert paraffinoid character, but the tendency for ring formationmay become sufficiently great to overcome this inertia, and themethane carbon atom then becomes involved in the formation of itnew ring,When the nitrosoacyl-o-toluidines are gently warmed in an anhydroussolvent, a condensation of this kind occurs and an indazole isDroduced.58\I--CH,The intervention of a methyl substituent also occurs when a mixtureof 2-methyl-1 : 2’-dianthraquinonylamine and lead oxide are added toaqueous potassium hydroxide at 170’.co CO\A/\/\I I I I v\/\/ cous-Dianthraquinon yl-p-acridone thus produced is a red substance,which on reduction gives an oxidiaable, violet leuco-derivative.59Several ortho-acridones of the anthracene series have been obtainedby the condensation of acetylmethyl-1-aminoanthraquinone and itsderivatives.CH,*?O HE--YOco N*CH, C N-CH,/\/\A -3- /\/\/’\I I I I I I I \/\/v \/\A/ co co57 RI.Maire, Bull. SOC. chim., 1908, [iv], 3, 272 ; A., i, 290.5t3 P. Jacobson and L. Huber, BET., 1908, 41, 660 ; A., i, 298.59 D.R.-P. 192436; A,, i, 456ORGANIC CHEMISTRY. 117I n these substances the methyl radicle is in an aliphatic group, but,nevertheless, the same tendency to the formation of six-memberedrings underlies the condensation.60o-Phenylenediacetonitrile (I), when warmed in alcoholic solutioncontaining a trace of sodium ethoxide, undergoes moleciilar rearraage-ment into P-imino-a-cyanohydrindene (11) :(11.1This product gives all the reactions of an imino-derivative, but whenthe cyanogen group is replaced by CO,H, C02*C2H5, or CO-NH,, thenthe structure changes to that of an aminoindene.The acid (111) doesnot lose its nitrogen until after carbon dioxide has been eliminated,when P-hydrindone (IV) is produced :C , H 4 < ~ ~ o ~ > C * N H 2 -+ C6H4<CH2>>C0. c=2(111.) UV.1The above p-imino-a-cyanohydrindene is hydrolysed by dilute acidsinto a-cyano-P-hydrindone (V) ; this compound yields a phenyl-hydrazone and a C-methyl derivative (VI), but also reacts in its enolicform (VII) to give rise to acyl and o-alkyl derivatives :(VII.)These results afford an interesting example of the formation of Lfive-membered ring, the structure of which is greatly influenced by thenature of its substituents.61The interaction of the primary aromatic amines and 2 : 3 : 5-trinitro-4-acetylaminophenol, a substance containing a singularly mobilenitro-group in position 3, leads to the production of iminazoles :OH OH OH/\NO, /\NO, /\NO,I-+ NO,(/NHPh --+ NO,j/-NPhNH*COMe lN:CMe NH-COMeDinitrohydroxy-1 -phenyl-methylbenziminazole.I n some cases the intermediate product can be isolated, but6o D.R..-P. 192201 ; A , , i, 456.61 C.W. Moore and J, F, Thorpe, Trans., 1908, 93, 165118 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.generally the ring formation occurs concurrently with the firstcon densation.62The disruption of an unstable four-membered ring, and the subse-quent formation of a more stable six-membered system, is illustratedby the condensation of primary amines and 4-nitroacetoanthranil :The process is general, for condensation occurred with extremereadiness with ammonia, methylamine, benzylamine, aniline andP-naphthylamine, and several other bases.63The well-known Slraup reaction has been utilised in the productionof technically important quinolines of the anthracene series.1-Amino-anthraquinone, condensed with glycerol in the presence of sulphuricand nitrobenzenesulphonic acids, yields anthraquinonyl-1-quinoline,Anthraquinonyl-1 : 5-diquinoline is prepared in a similar mannerfrom 1 : 5-diaminoanthraquinone : G4The Skraup synthesis, applied for the first time in the phenanthreneseries, has led to the production of 9 : 10-phenanthraquinoline from9-aminophenanthrene,G5A t the present time a special interest attaches to carbazole and itshydrogenated derivatives, owing to their possible relationship with thealkaloids of the strychnine group.Starting from the cyclohexanones,which are now readily procurable, a fairly general method has been82 R. Meldola and J. G. Hay, Trans., 1908, 93, 1659.63 M. T. Bogert and W. Klaber, J. Amer. Chem. SOC., 1908, 30, 807 ; A . , i,G1 D.R.-P. 159234 ; A . , i, 365.65 F. Herschniann, Ber., 1908, 41, 1998 ; A., i, 683.466ORGANIC CHEMISTRY. 119worked out for the synthesis of tetrahydrocnrbazole and its homo-logues :H H NHTetraliydrocarbazole.The aromatic hydrazones of these cyclic ketones undergo condensationwhen gently warmed with dilute acids.The reaction is general forall aromatic hydrazines containing one free ortho-position, but onlytakes place with simple saturated cyclic ketones, and not with thosecontaining either unsaturated or bridged rings.66Tetrahydrogenated acridines have been obtained from the cyclicketones by the following methods.1. Condensation with aromatic o-amino-aldehydes and ketones :3.\/\\/OCRNH,/l I -+H CR2. Condensation with isatin and alkali hydroxides :3. Condensation of the o-acylketohexamethylenes with aniline andThis process leads t o a mixture of n tetrahydro- its homologues.acridine with a tetrahydrophenanthridine :9133H CHHI H&JO*C 1.0 H3 NH2-!{/ /\ I --3 H A / \ / \HI I /I I\/\/\/ \ / * HH NNH2\/\1 if\/-+G6 W.Borsche, Annnlen, 1908, 359, 49; d., i, 365120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The foregoing hydroaromatic carbazoles and acridines can betransformed into the corresponding aromatic compounds by heatingwith lead oxide.67Diphenanthracridine (I) and phenophenanthracridine (11) havebeen prepared, the first by condensing 9-aminophenanthrenewith methylene halides, and the second, by treating the same basewith o-nitrobenzyl chloride and stannous chloride.68The foregoing cases of ring formation are all examples of thegeneral tendency to the production of five- and six-membered cyclicsystems. This rule is not, however, without important exceptions,and seven- and eight-membered rings do occasionally make theirappearance, The cyclooctadienes, mentioned in connexion with thechemistry of the terpenes and indiarubber, contain a ring of eightcarbon atoms.The following remarkable series of reactions, published towards theclose of 1907, illustrate the exceptional case of the conversion of abenzene nucleus into a seven-membered ring.Reference has already been made, under the heading of aliphaticdiazo-compounds, to the great variety of products obtainable fromethyl diazoscetate. One of the most remarkable properties of thisester is its reaction with benzene and its homologues.When gentlywarmed with one of these hydrocarbons, nitrogen is evolved, and thebivalent residue, CO,Et*CH<, attaches itself to two contiguouscarbon atoms of the aromatic nucleus with the formation of a bicyclicsystem, consisting, as a wholo, of a seven-membered ring, but dividedinternally by a bridged linking into two cyclic components, one contain-ing three, and the other six, members.The case of m-xylene was des-cribed in the last communication on this subject, and as it resemblesthose of toluene and benzene, it may be taken as an illustration of thiscondensation.Inasmuch as the bicyclic structure is like that existing in carone,the initial product receives a name derived by transposition from thatof the analogously constituted ketone. This methyl 1 : 3-dimethyl-norcardienecarboxylate (I), so far, retains an aliphatic character, that6' Borsche, Ber., 1908, 41, 2203 ; A ., i, 682.68 P. C. Anstin, Tm?u., 1908, 93: 1760ORGANIC CHEMISTRY. 121it yields the amide (11) on treatment with ammonia, Alkalinehydrolysis, however, converts it into a monocyclic acid (111),3 : 5-dimethylcyclo-A2'3 ' 5-heptatriene-l-carboxylic acid. The amidegives rise to the isomeric 3 : 5-dimethylcycEo-A3 : : 7-heptatriene-l-carb-oxylic acid (IV) when hydrolysed with alkalis, but under the influenceof acids the heptatriene ring is transformed again into a benzene ring,and 3 : 5-dimethylphenyl-4-acetic acid (V), isomeric with the twoheptatrienecarboxylic acids, is produced.6g(?H:CMe'$H fl>CH*CO,Me --+ C H : C M e * ? H > ~ ~ * ~ ~ , ~ e I --+ CMe:CH*CH N CMe:CH*CHCMe:CH-CH(111.)Mordant Colours as Heterocyclic Complexes.The theory that the coloursproduced on mordanted fabrics owetheir existence to the formation of heterocyclic complexes in whichthe metallic oxide or hydroxide becomes a component of the ring, hasbeen discussed by A.Werner and C. Liebermann. Both agree onthe general principle that the peculiar properties of these lakes aredue t o a ring structure involving the metallic base. The greatstability and sparing solubility of lakes, the remarkable differencesbetween their colours and those of the ordinary salts containing thesame metal, and the singular fact that in many cases the metal doesnot exhibit certain of its characteristic analytical reactions, all justifythe theory of a heterocyclic constitution for these dyes.Werner adduces many instances in which ring structure is possibleonly on the assumption that both the principal and secondaryvalencies of the metal are involved in ring formation.Benzoylacetone and similar compounds are shown to behave asweak dyes on mordanted cotton. The lakes thus produced must besimilar in structure to the closely allied metallic acetylacetonates, towhich on account of their great stability a co-ordinated constitutioni s ascribed.Accordingly these lakes are also formulated as co-69 E. Buchner and E. Delbruck, Annalcn, 1907, 358, 1 ; A., i, 87122 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ordinated compounds (I), where R is an alkyl or acyl radicle and M isthe metal.O*CRM< >CH‘0:CR,C:CH*O(1. ) (11.)This view of their constitution is justified by the fact that hydrouy-methylenecamphor, a compound in which the keto-enolic structure isthe stable form, also behaves as a mordant dye, the lakes of whichmust have the above formula (TI).Liebermann, on the other hand, assumes that in those cases wherea carbonyl group is contiguous to the hydroxyl or isonitroso-radicle,it is only necessary to make the very reasonable assumption that thisgroup reacts in its hydrated form (I11 and IV), and then the oldertheory becomes sufficiently comprehensive to include all cases ofmordant dyeing without recourse to the hypothesis of supplementaryvalency.\ H.0’ OH(111.) (IV- 1Werner, in reply, points to the fact that the ordinary theory ofvalency does not account for the great difference in colour andstability between the lakes and the colourless salts of certaindibasic acids, many of which also possess a cyclic structure :According to Werner the production of a metallic heterocycliccomplex leads to the development of colour and other propertiespeculiar to lakes only when both the supplementary and principalvalencies of the metal are involved in the structure of the ring.70Quuinmes.The interest attaching to the aromatic diketones and theirderivatives is due to the fact that the existence of these compoundsaffords justification €or the assumption so frequently made that the firstphase in the interactions of aromatic substances and various reagentsis the formation of an additive product in which the valencies of thearomatic nucleus have undergone a certain rearrangement.Whenthe new arrangement persists in the final product, this substance isregarded as a, quinone derivative or quinoid.1436 ; A., i, 441.7O A. Werner, Ber., 1908, 41, 1062, 2383 ; A., i, 440 ; C. Liebermann, ibid.ORGANIC CHEMISTRY. 123I n the simplest case of benzene, we may have the change fromC,H,II to p- or o-C6Htv.fC\/C\/C\/C v c'\/CI /\ /\Corresponding with these two types of rearrangement there existthe long known p-benzoquinone and the more recently discoveredo-benzoquinone.A t first only quinones of the ortho- and para-series were known,but lately the possibilities of quinonoid rearrangement have been con-siderably extended by Willstatter and his collaborators.In 1907 itmas shown that 2 : 6-dihydroxynaphthalene could be oxidised so as toyield the corresponding 2 : 6-naphthaquinone,71c1whilst 1 : 5-dichlors-2 : 6-dihydroxynaphthalene furnishes 1 : 5-dichloro-2 : 6-naphthaquinone, a substance possessed of considerable stability,I n continuing the study of o-benzoquinone it has been found thatwhen catechol is rapidly oxidised (15 seconds) with pure silver oxide indry ether a colourless modification of the quinone can be isolated,This colourless variety, which is very unstable and changes quickly intothe red modification, is also obtained when an ethereal solution of thelatter is cooled, The two forms are therefore in equilibrium insolution.These isomerides are represented by the following formulae,the colourless variety being regarded, not as a quinone, but as abenzene peroxide.72H HC C/\vHQ $XOHC C:OcHRed.\/ CHColourless.71 R. Willstatter and J. Parnas, Ber., 1907, 40, 3971 ; A., 1907, i, 1056.72 R. Willstatter and F. Miiller, ibid., 1908, 41, 2580 ; A., i, 731124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The colour of m-nitroaniline and its derivatives was long agoascribed by H. E. Armstrong to the existence of a dynamic formhaving a meta-quinonoid structure, and more recently Baly has re-ferred to the possibility of a meta-qninonoid rearrangement. Thesespeculations have now been justified by the revision of the constitutionof tribromoresoquinone, a yellowish-red substance originally discoveredin 1872 by Liebermann and Dittler, who prepared i t by removing twobromine atoms from tribromoresorcinol dibromide, and gave it theformulaMolecular-weight determinations in boiling benzene have now shownthat the substance has the simpler formula C,HO,Br,, and as itliberates iodine from potassium iodide, it is regarded as a meta-quinone, namely, 2 : 4 : 6-tribromo-m-benzoq~inone,~30 ..This substance gives neither oxime nor hydrazone, for hydroxyl-amine and phenylhydrazine behave towards it as reducing agents andconvert it into tetrabromodiresorcinol, C,HBr2(OH),*C,HBr2(0H),.One of the most characteristic reactions of quinones is the formationof intensely coloured additive compounds with their reduction products ;quinhydrone produced by the combination of p-benzoquinone and quinolin molecular proportions being perhaps the best known example ofthis class of substances.That this property is not restricted topara-quinones is shown by the fact that tetrachloro-o-benzoquinonecombines with tetrachlorocatechol to form octachloro-o-quinhydrone,C,C1,O2,C,H,C1,O2,~H20, a substance separating in lustrous, blackneedles.T4 Willstatter proposes to call these additive compounds,which consist only partly of a quinonoid complex, meriquinoids,whilst the quinones themselves and their derivatives (imines, etc.)are termed holoquinoids. The formation of the meriquinoids isattributed to the residual affinity of the quinonoid oxygen atoms, orin the case of the quinoneimines to that of the imino-group. Theintense colour of the additive product is considered to be due to anoscillation (isorropesis) of the quinone linking between the two7y R.Meyer and K. Desamari, Be?., 1908, 41, 2437 ; A . , i, 658.74 C. L. Jackson and P. W. Carleton, Amer. Chern. J., 1908, 39, 493 ; A., i,427ORGANIC CHEMISTRY. 125components of the molecular compound. I n this way the colour of themeriquinoids is referred to the same cause as that which is assumedby von Baeyer t o be operative in the di- and tri-phenylmethanecolouring matters, namely, the oscillation of the quinonoid conditionbetween two or three aromatic nuclei.These views on the colour of quinhydrones and meriquinoids arenot accepted unreservedly by F.Kehrmrznn,75 who objects to theparallel drawn between quinoneimines and their meriquinoid salts,on the one hand, and the triphenylmethane-imine bases and theirsalts on the other. I n the first case, the intensification of colour isdue to the introduction of auxochromic groups (NH2 or OH) withoutany modification,of the chromophore ; in the second, the bases andtheir salts are quite different in constitution, and the variation ofcolour is due to this complete change in the configuration of thechromophore. The difference in stability between the ordinaryquinhydrones and the meriquinoids (Wurster's salts, etc.) is merelyone of degree, and there is no reason for assuming that these twotypes of partial quinoids differ essentially in constitution.The coloured salts formerly obtained by 0.Wurster 76 on oxidisingalkylated p-diamines are regarded as meriquinoids by Willstiitter.The red salt produced by the action of bromine on ns-dimethyl-p-phenylenediamine is meviquinonedimethyldi-imonium bromide,I II II I/\/ \/NMe, .---------- NMe2Br( NO,)The nitrate has also been obtained, and the blue salt fromtetramethyl-p-phenylenediamine contains a sulphate which is onlyone-third quinonoid,C6H4[NMe,*HS0,],,2C,H4(NMe),,€I,S0,.Benzidine gives rise to two meriquinonoid chromates, whilst bothholo- and meri-quinoids have been obtained from tetramethyl-b e n ~ i d i n e . ~ ~Further investigations on the oxidation products of benzidine,diphenyline, and tolidine have resulted in the production of dipheno-quinonedichlorodi-imide, NC1:C,H4:C6H4:NC1, ditoluquinonedichloro-BcT., 1908, 41, 2340; A., i, 698.R.Willstatter and J. Piccard, ibid., 1908, 41, 1458 and 3245 ; A., i, 475,'13 B i d . , 1879, 12, 1803 ; 1887, 20, 2071.915126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.di-imide, h010- and meri-dichloroditoluquinonedi-imonium chlorides,the last of these having the composition 78r 01 -lNH,<-\-/-\NH, --/ \-/Me Mec1 c12HC1, xH,O.The action of alkali hydroxides on 1-phenylisoquinolinium meth-iodide and papaverinium methyl halides leads to the formation of2-phenyl-a-naphthol and 6 : 7-dimethoxy-2-mp-dimethoxyphenyl- a-naphthol, which on oxidation yield binuclear quinones having theappearance of indigotin.790 00 0The residual affinity of quinones is also manifested by the formationof additive compounds with certain inorganic chlorides.The followingare representative examples of this series : p-benzoquinone stannicchloride, C,H,0,,SnC14 (red), a-naphthaquinone antimonic chloride,C,oH,02,2SbCI, (red), P-naphthaquinone stannic chloride (green),phenanthraquinone mercuric chloride, 2C,,H,02,HgC1, (red).*OAromatic ketones behave similarly, and the following yellow com-pounds have been obtained,. benzophenone antimonic chloride,CPh20,2SbC1,,and benzil stannic chloride, (COPh),,SnCl,.F. Kehrmann refers the production of these compounds to the salt-forming capacity of quinonoid oxygen, and points out that he hadpreviously shown that phenanthrnquinone and chrysoquinone aredibasic substances forming two series of salts.81An ingenious use of the properties of pheriyliminoquinones has beenmade in the study of the tri-, tetra-, penta-, hepts-, andocta-hromo-7a W.Schlenk, Annalen, 1908, 363, 313 ; A., 1909, i, 36.79 H. Decker, ibid., 362, 305 ; A . , i, 806.so K. H. Meyer, Ber., 1908, 41, 2018 ; A., i, 731.*l Ber., 1908, 41, 3396 ; A., i, 993ORGANIC CHEMISTRY. 127derivatives of p-hydroxydiphen ylamine. I n each case, oxidation withchromium trioxide gives rise t o the corresponding quinoneanil (phenyl-iminoquinone), the colour of which becomes more intense as the pro-portion of bromine increases, t h e shades varying from scarlet to apurple so dark as to appear black.These substances readily undergo hydrolysis, so that the number ofbromine atoms present in each ring, and, in some cases, also theirorientation, are readily ascertained : 82Br Br Br Br Br BrBr Br BrB/'-\NH, + o:/=\:o.\-/ \=/Br Br BrAn extremely interesting synthesis of quinones from straight-chaincompounds has been effected by a modification of the process for pro-ducing ethyl alkyloxalacetates. A mixture of ethyl oxalate and anester of a monobasic fatty acid is treated with sodium instead ofsodium ethoxide, whenbenzene is produced :R*CH,* C0,EtCO,Et*CO,Et$.!O,EtL'O*CORCH2 \ CH,R \co*yoC0,Eta hydroxyquinone derived from a p-dialkyl-vO,E tAtmospheric oxygen intervenes in the last step of this condensa-tion, which takes place so readily that it may be employed as a lectureexperiment to demonstrate the formatio of a coloured quinoiie fromcolourless, comparatively simple, aliphatic esters.I n the foregoingscheme, R may be methyl, ethyl, isopropyl, n-butyl, phenyl, or benzyl.These hydroxyquinones are yellow, whereas their alkali salts arebl uish-viole t.Equally noteworthy is the unique hydrolysis of these dihydroxy-dialkylbenzoquinones under the influence of boiling aqueous alkali82 A. E. Smith and K. J. P. Orton, Trans., 1908, 93, 314128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hydroxides, when the ring structure disappears with the production ofsymmetrically disubstituted succinic acids,CO,H* CHR*CH( CH,R) *CO,H,which are always obtained in their two stereoisomeric modifications,so that in some cases the reaction may withadvantage be employed inthe preparation of these isomerides.I n this hydrolysis, the hydroxy-quinones react in their tautomeric form :co*co RYH* C0,HCH,R CH C0,H C(0H)-CH,R --+ RCH<C-b -+R CH<CO' C02H/\C0,H CH,k C02HThe triketocarboxylic acid containing an a-diketonic group under-goes the benzilic acid change to a dicarboxylic acid which condenses toa lactonecarboxylic acid ; this compound then takes up water and losescarbon dioxide to form the disubstituted succinic acid.The penultimate product, the lactonecarboxylic acid, was in oneinstance prepared by an independent method and shown to undergo thelast step in the hydrolysis under the influence of alkali hydr0xides.~3I n connexion with the production of quinones, reference may bemade to the more recent of Zincke's long series of researches on thechlorination and bromination of phenols.84Di-p-hydroxydiphenylmethylethylmethane yields a tetrabromo-derivative, HO*C6H,Br,~CMeEt*C6H,Br,~OH, which on furtherbromination is resolved into s-tribromophenol and the +-hexabromideof p-sec.-butylphenol ; a t 100' a $-heptabromide is produced. These$-bromides, which unlike the less brominated phenols are insoluble inaqueous alkali hydroxides without decomposition, readily losehydrogen bromide when treated with sodium acetate or sodiumcarbonate, and give rise t o quinones :C,H, CHBr,\/H CBr\/Br A B rBr" "Br \/ ..0+-p-Tribromo-sec. -butyltetra-bromophenol.(Colourless hemiquinone.)-+C H CHBr, </ C ..Br/\BrBrll I ' B ~ \/ 0p-Dibromo-sec. -butylidenetetra-bromoquinone.(Yellow quinone.)83 F. Fichter, Annalen, 1908, 361, 363; A., i, 658.84 T. Zincke and J. Goldernaim, ibid., 362, 201 ; A., i, 780; T. Zincke andE. Birschel, ibid., 221 ; A., i, 781ORGANIC CHEMISTRY. 129The tetrwhloro- and tetrabromo-dihydroxybenzhydrols (I), whentreated with hydrogen chloride and hydrogen bromide respectively,y iel d the $-pen tac hloro- and +-pen tabromo -di hy drox ydiphenylmet h y 1chloride and bromide (11). These halides, when shaken with aqueousacetone, lose hydrogen halide and furnishbromo-hydroxybenzylidenequinones (111).OH OHABr()BrIIAB r U B rOHBr()Br I0(1.1 (11.)derivative.hemiquinone.Colourless benzenoid Colourlessthe tetrachloro- andOH0(111.)qcunone.Yellowtetra-These examples suffice to show the close relationship between theappearance of colour and the development of the complete quinonoidconfiguration. Of interest in this connexion is the preparation ofcoloured hydrocarbons of the quinodimethane series, of which thefollowing synthesis is an example :Benzoyltriphenylmethane, COPh°C6H4*CHPb2, when subjected tothe Grignard reaction with magnesium a-naphthyl bromide, yields asubstituted benzhydrol, HO*CPh(C,oH7)*C,H4*CHPh2, from whichp-benzhydryldiphenyl-a-naphthylmethyl chloride (I),C1*CPh(CloH,)*C,H4*CHPh2,is readily obtained by the action of hydrogen chloride. This chloride,when heated with quinoline, loses hydrogen chloride, giving rise tothe orange-red hydrocarbon, triphenyl-a-naphthylquinodimethane (11).This hydrocarbon absorbs halogen halide, regenerating the chloride (I).These changes constitute a reversible reaction, which may berepresented as follows : 85(I.) Colourless benzenoid derivative.(I I. ) Coloured quinoid.Recently several methods of oxidising aromatic hydrocarbons toquinones have been patented, based on the indirect employment ofelectrolytic methods. For example, manganic alum, produced electro-lytically from an aqueous solution of manganous and ammonium85 A. E. Tschitschibabin, Ber., 1908, 41, 2770 ; A., i, 872.REP.-VOL. V. 130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sulphates, is recommended for oxidising naphthalene, anthracene, andphenanthrene to their respective quinones.s6Colour and Constitution.Contributions to the study of the relation of colour to structurehave again been very numerous, and in several of these a comparisonhas been made between colour and fluorescence. Starting from themuch-discussed case of nitroquinol dimethyl ether, an examination ofa large number of coloured and fluorescent substances 87 has shownthat the colour of the light emitted in fluorescence is quite commonlydependent on the solvent employed.The fluorescent band of the solidsubstance lies furthest towards the nltra-violet, then follow the solu-tions in indifferent solvents, then those in dissociating solvents, thefluorescence of the vapour exposed to Tesla-radiation lying nearest tothe red.This is true even of compounds in which it is impossibleto assume a change of constitution to be brought about by dis-sociating solvents. Changes of colour in general run parallel withfluorescent changes. The theory of partial valencies is invoked inexplanation of these facts. Considering the ordinary statical formulaeas representing an ideal constrained state of the molecule, the solidsubstance and its solutions in indifferent solvents are supposed toapproach most nearly to this, whilst a greater freedom of the partialvalencies is possible in dissociating solvents and in the state of vapour.Nitroquinol dimethyl ether is then written in the form (I), theMe0I()-NO2\/IMe0formula (11) representing the ideal limiting condition.The paler thecolour of the solution the more nearly the molecule approaches to thelimiting condition, which is, however, never completely attained.m-Nitrodimethylaniline is a good example of a compound showingvariable fluorescence. The results are unfavourable to the assumptionof a quinonoid structure. The influence of solvents in modifying thedirection of the lines of force which constitute the partial vnlenciesis illustrated and discussed.*6 D.R.-P. 189178 ; A . , i, 350.87 H. Kauffmann, Ber., 1908, 41, 4396 ; A., 1909, i, 96ORGANIC CHEMISTRY. 131Somewhat different results have been reached by a very exhaustivestudy of the triphenylmethane (or 6‘, tritane ”) series.88 It is shownthat the parallel between colour and fluorescence must not be pressedtoo far.Simple ring compounds, such as benzene, are fluorescent,although the emitted light lies in the ultra-violet portion of thespectrum, and by substitution, or by the juxtaposition of rings, theoscillations causing fluorescence may be so far retarded as t o enter thevisible region. Thus anthracene has a distinct fluorescence. Theproduction of colour occurs in a quite different way. The replacementof hydrogen in benzene by substituents, however heavy, is quiteincapable of retarding the oscillations so as to bring the ultra-violetabsorption of benzene into the visible region. The colour of benzenederivatives is brought about, not by the shifting of a previouslyexisting ultra-violet band towards the red, but by the production of anew band or bands, and for this a definite arrangement of conjugateddouble linkings is required.The author considers the key to theproblem to be given by a comparison of benzene with its isomeride,fulvene. In both compounds, the number of carbon and hydrog6n atoms,and of double linkings is the same, and only the disposition of thelatter is altered.FH:CHCH:CH >C:CH,.Benzene (colourless). Fulvene (coloured).From a comparison of a large number of coloured substances, theauthor concludes that there is only one true organic chromophore,R R RA-A-Anamely, the grouping \I II It, with three double linkings. Thisgrouping is not, however, sufficient in itself to bring about colour, butrequires some further condition (m&t frequently the closing of a ring)to produce visible colour. The reason for this is that the double link-ings must first be brought into a definite relative position before therhythmic oscillations which cause colour can b9 set up.It will beobservedgrouping,that nitroquinol dimethyl ether contains the requiredtogether with the ring :C OMeaa H. von Liebig, Anzalen, 1908, 360, 128 ; A., i, 445.K 132 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Coloured solutions of such simple coloured substances as diacetylmust contain polymerised molecules in order to render the abovegrouping possible, an assumption for which there is good evidence.Fluorescence is explained as due to a pulsating interchange ofdouble linkings in rings, brought about by impinging light-waves.The tritane derivatives examined ranged from the colourless triphenyl-methanet through compounds exhibiting both colour and fluorescence,to the penta- and hepta-acetyl derivatives of the complicated hydroxytritanol ether,OH OH OH OH <>-ox I I (/OHA- /\ICPh, CPh, YPh, QPh,co co-o-OH\/ I \/ I YI OH OHwhich exhibit colour, fluorescence, and pleochroism, a property hithertoonly possessed by chlorophyll amongst colouring matters.The picryl ethers of certain amidines have been noted as showing aremarkably strong fluorescence, a1 though nitro-groups generallyhinder the appearance of this property.89 The non-fluorescent1 : 2-diphenyl-3- benzyloxyamidine yields a highly fluorescent ether,and the same is found to be true of other non-fluorescent imide bases.The essential grouping appears to beIR C N RI .-----IN*O*CaH,(NO,),R'and that the residual affinity of the nitro-groups, acting in the direc-tion of the imino-nitrogen atom, is connected with the property issuggested by the fact that the salts of the same imides with heavymetals, which are certainly internally complex, are highly coloured .The phenyl groups are not necessary, since picryl diguanide,NH,*Q :NHNH,*C:NHy*O.C,H,(NO,), ?is also fluorescent.The effect is attributed to internal oscillations oflinking in the molecule.Pulsations of the ring-system of benzene were invoked to explainthe absorption of benzene in the ultra-~iolet,~0 it being shown that the89 H.Ley, Ber., 1908, 41, 1637; A., i, 570.90 E. C. C. Baly, W. H. Edwards, and A. W. Stewart, Trans., 1906, 89, 514ORGANIC CHEMISTRY. 133number of absorption bands corresponded with the number of distinctmodes of deformation of the ring. This hypothesis has now been putto a severe test by the examination of compounds containing morethan one ring.g1 Naphthalene itself has three bands in the ultra-violet, one of which is attributed to the benzenoid ring, and the othertwo to the conjugation of this with the ethylenic linkings of thesecond ring. When this second ring is entirely reduced in 1 : 2 : 3 : 4-tetrahydronaphthalene, only the one benzenoid band is observed.I n1 : 4 : 5 : 8-tetrahydronaphthalene, the two rings are exactly alike, andthe symmetrical arrangement resembles that of p-xylem, and the twospectra are consequently almost identical.A similar spectrum is given by acenaphthene (I), whilst acenaph-thylene (11) has, in :addition, bands due to the influence of the doublelinking outside the ring, producing colour.CHZCHThe complete absorption spectra of a number of compounds contain-ing nitro- and nitroso-groups have been examined, and the position of theband is found to depend on the nature of the atom to which the groupis atta~hed.~2 Dinitro-paraffins form both coloured and colourlesssolutions, the spectra OF the former, and of the alkaline salts of thesecompounds, being unlike those of aci-mononitro-salts, R*CK*NO,M.They are therefore assumed to contain an isomeric modification withquinonoid grouping, R* C< NO(0M) No->O, producing colour, in equi-librium with the colourless f0rm.~3In continuation of the work on the strongly-coloured aci-ethers ofnitrophenols, a dark violet aci-ether of hexanitrodiphenylamine hasnow been prepared94 from the violet silver salt, It is thereforeassumed to have the quinonoid constitution,C6H2(N02)s*N:C6H2(N02)~:No2Me.The fact that halogen-phenols, in which it is difficult to assume aquinonoid rearrangement, form both coloured and colourless silversalts 95 points to the necessity of further investigation of this kind ofisomerism, and an interesting case of the same kind has been recentlydiscovered.9691 E. C. C!, Baly and W. B. Tuck, Trans., 1908, 93, 1902.92 E. C. C. Baly and C. H. Desch, ibid., 1747.9s E. P. Hedley, Ber., 1908, 41, 1195; A., i, 382.94 A. Hantzsch and S. Opoloski, ibid., 1745 ; A . , i, 526.g5 Ann. Report, 1907, 114.96 0. Dimroth and 0. Dienstbach, Ber., 1908, 41, 4055 ; A., 1909, i, 62134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.-4-Oximino- 1 -phenyl-5- triazolone, N€’h<N -r forms three CO*C:N*OH’series of salts, yellow, red, and green, of which the red is usually t hstable form, although the red silver salt is labile, and passes into thestable green modification. Further, the benzoyl and acetyl deriv-atives, which no longer contain a labile atom, also occur in red andyellow modifications, of which the latter is the stable form.That thecase is one of chemical isomerism, and not merely of polymorphism, isshown by the fact that the red benzoyl derivative dissolves inchloroform to a deep red solution, which, however, immediatelybecomes yellow. Concentrated solutions are orange, and contain thetwo modifications in equilibrium.Many aminoazo-compounds are known to form two series ofdifferently coloured salts. The orange salts 97 resemble azobenzene incolour and must have the azo-constitution,Ph*N:N*C,H,*NR,HX,whilst the violet salts are quinonoid, as, for example,Ph*N H*N: C6H,: NMe,CI.The solid orange salts are usually labile, and are converted into theviolet salts on heating, or, in some cases, on rubbing.The violet salts were proved to be unimolecular in solution.Indifferent solvents favour the violet modification, whilst the orangemodification persists in alcohol, ether, or acetone.The solutions inconcentrated sulphuric acid are all yellow, and resemble azobenzene.The same colour relationships appear in the aminoazobenzene-sulphonic acid series, and the colour-changes in helianthin and methyl-orange have therefore received a similar e ~ p l a n a t i o n , ~ ~ the inter-mediate formation of an internal azo-salt being assumed, as representedin the following scheme :Helianthin.1/ \ Methyl-orange.I n aqueous solution. Solid andL Solid. r > in solution.Violet. Orange. Orange. Orange.C,H4* so, C6H,* so, C H *SO,H C,H,*SO,NaI S * -+ N NaOH iJ 1 + - ~ - 3 M ‘H I HzO -+ #l l I I IC,H,: NMe,Quinonoid.Azo.C6H,*NMe2H C6H4*NMe, C,H,*NMe,Azomethines are of interest from their analogy to azo-compounds.Since the simplest nzomethines and their ethers are colourless, whilsttheir hydrochlorides show an absorption band in the blue region of the97 A. Hantzsch and F. Hilscher, Ber., 1908, 41, 1171 ; A., i, 484.93 A. Hantzsch, ibid., 1187 ; A., i, 469.& ORGANIC CHEMISTRY. 135spectrum, it has been concluded 99 that the latter are quinonoid oxoniumsalts, the simplest ethyl ether hydrochloride, for instance, having theformula C6H,*CH2*N:C6H,:o<cl. EtA. recent observation 1 is of interest as showing that the possessionof residual affinity may suffice to give chromophoric properties toa group of compounds, even when no ethylenic linking is present.Iodochlorides, such asOMeare strongly coloured red.Hitherto all chromophores attached to thebenzene ring have contained a double bond.The investigations into the constitution of triphenylmethyl, whichderive their interest mainly from their bearing on such problems asthose just discussed, have added little to the knowledge summarisedin last year’s Report (p. 118). The hexaphenylethane formula seemswell established for the solid substance. An attempt to preparehexaphenylethane by heating triphenylmethyl triphenylacetate,CPh,*C02*CPh,,2yielded only an amorphous product, together with triphenylmethane.The product obtained from Gomberg’s triphenylmethyl, and formerlysupposed to be hexaphenylethane,3 is now4 proved to be p-benz-hydryltetraphenylethane, CHPh2*C,H4*CPh,.by its synthesis fromp-benzoyltriphenylmethane, which reacts with magnesium phenylbromide to form p-benzhydryltriphenylcarbinol ; condensation withaniline hydrochloride and elimination of the amino-grmp then givesGomberg’s compound, which is thus an isomeride, and not a polymeride,of triphenylmethyl. The preparation of the latter compound fromthe magnesium chloride has been improved,5 and the existence ofisomeric modifications of magnesium triphenylmethyl chloride hasbeen defended against the criticisms of Tschitschibabin. The existenceof both a coloured and a colourless modification in solutions of tri-phenylmethyl is inferred from the disappearance of the yellow colouron shaking with air, the yellow modification being the more readilyoxidised.6 On removing the peroxide by filtration, the colourless99 F.G. Pope, Trans., 1908, 93, 532, 1914.H. Kauffmann, Ber., 1908, 41, 4413; A., 1909, i, 95.R. Anschiitz, Annalen, 1908, 359, 196 ; A., i, 331.M. Gomberg, ibid., 1903, 36, 370 ; A., 1903, i, 244,A. E. Tschitschibabin, Ber., 1908, 41, 2421 ; A., i, 624.J. Schmidlin, ibid., 1908, 41, 423, 426 ; A . , i, 150.Ibid., 2471 ; A., i, 623136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.filtrate again becomes yellow, an ethereal solution in equilibrium atthe ordinary temperature containing about ten times as much of thecolourless as of the coloured form. Lowering the temperature favoursthe production of the colourless modification.The theoreticalexplanation of these facts has made little progress since last year.Aromatic Diaxo-compounds.I n last year’s Report reference was made to a new formula (11) fordiazonium salts advocated by Cain,7 which was put forward to account2(1.) (11.) (111.)for the following facts : (1) The property of giving rise to diazoniumderivatives is confined to the aromatic primary amines, and is notpossessed by the bases of the fatty series or fully saturated ringseries; (2) the facility with which nitrogen is eliminated fromdiazonium salts suggests an unstable double linking \GIN, ratherthan the single linking \CON, assumed to be present in theKekuld (IV) and Blomstrand (V) formulae?///C6H,*N:N*C1 C,H,*NCli N.(IV.) (V.1An ortho-quinonoid configuration would, however, afford an equallysimple explanation of these facts, and accordingly i t has recently beensuggested that diazonium salts might appropriately be represented bya dynamic formula, in which the valency of the triad nitrogen atomin the foregoing static ortho- and para-quinonoid formulae (I, 11, 111)is directed sucessively to the carbon atoms marked 1, 2, and 3, but isnot held continuously by any one of them. This extremely labilecondition of the oscillating linking would account for the productionof hydrazines rather than diamines on reduction.8These views on the structure of diazonium salts have beenvigorously attacked by Hantzsch,g who contends that if diazoniumsalts are hemi-p-quinoids, as represented by Cain’s formula, then onreduction they should yield p-diamines and not hydrazines.He alsorepudiates the suggestion of a. dynamic formulation, contending that7 Ann. Report, 1907, 120.8 G. T. Morgan and F. M. G. Micklethwait, Trans., 1908, 93, 617.Ber., 1908, 41, 3532ORa ANlC CHEMISTRY. 13’7this hypothesis, instead of obviating the difficulty of explaining theproduction of hydrazines rather than diamines, increases it twofoldinasmuch as a mixture of ortho- and para-diamines should result fromthe reduction of such a compound. This view of the matter, however,involves the assumption that the properties of a substance with adynamic structure are simply those of the tautomerides representingthe extreme phases of the molecular oscillation. It is at leastconceivable that the predominant properties of the compound mightbe those of the intermediate phase or phases.This conception, whenapplied to diazonium salts, furnishes a reason for the formation ofhydrazines as the main products of reduction.Cain,lo who has replied to Hantzsch’s criticisms of his formula,points out that there is experimental evidence for the view thatreducing agents would break the unstable linking, >CH*N, ratherthan the more stable azo-bond, -N:N-. He also calls attention toHantzsch’s admission that the existence of aromatic diazonium saltsand the non-formation of such derivatives of the aliphatic aminespoint to some interaction of the residual affinities of the aromaticnucleus with the unsaturated diazonium complex. He maintains thatthis connexion is more definitely expressed by his quinonoid formulathan by the vague addition made by Hantzsch to the Blomstrandconfiguration formula and expressed by the dotted line in thefollowing formula, C,H,*N2X.Euler,ll who advocatesanother para-quinonoid formula for diazoniumsalts,.-. .also lays stress on Hantzsch’s admission of the imperfection of theBlomstrand formula (V.).Although these controversial matters require further experimentalevidence for their complete elucidation, yet this’discussion has servedthe useful purpose of recalling attention to the important fact, sofrequently overlooked, that the residual affinity of the aromaticnucleus is the determining factor both in the production of diazoniumsalts, and also in many other characteristic properties of aromaticcompounds.The study of the decomposition of diazonium salts in solutions oflo Ber., 1908, 41, 4189 ; A ., 1909, i, 70.ll. Ibid., 3979 ; A , , 1909, i, 70138 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.varying strengths and at different temperatures has led to thefollowing results.121. Dry:diazonium chlorides give the maximum value for the velocityof decomposition in aqueous solutions. Freshly prepared specimensdecompose more slowly, and contain apparently traces of a protectingsubstance, the nature of which has not been elucidated.2. Diazonium chlorides and bromides in solutions of the gameconcentration decompose at the same rate.3.Increase in the concentration results in a small rise in thevelocity of decomposition, which is somewhat greater with thebromides than with the chlorides. The velocity increases as thedecomposition progresses, probably owing to the formation of halo-genated hydrocarbons by the action of the liberated hydrogen halide.4. Diazonium iodides decompose more rapidly than the chloridesor bromides, even in very dilute solutions.5. Increase of concentration has but little effect on the velocity ofdecomposition of p-nitrobenzenediazonium chloride, and only in veryconcentrated solutions is any acceleration noticed. Neither strongnor weak acids have any protecting influence.6. The less basic is the diazonium hydroxide set free by hydrolysisthe more rapidly is the diazonium acetate decomposed in aqueoussolution, Sodium chloride has a protecting influence on p-nitro-benzenediazonium acetate.7.Nitrous acid decomposes diazonium salts, not catalytically,but by actual participation in the decomposition.The experimental data on which this last generalisation is basedagree with those formerly obtained by Cain,13 and confirm hisopinion that a solution of pure p-nitrobenzenediazonium chloride andanother containing the same concentration of this salt with a traceof nitrous acid sufficient to give the starch-iodide test decompose withequal velocities under similar conditions of temperat~re.1~A study of the oxidation of primary aromatic hydrazines has led toa method of converting these substances quantitatively into thediazonium salts, from which they were obtained by reduction.In the first place, the oxidation of these hydrazines with copper,silver, and mercuric oxides leads to the deposition of the correspond-ing metal, with the liberation of nitrogen and the formation of ahydrocarbon :R*NH R*NH R N H + H N b H 4 H ~ O H -+ H ~ Hl2 A.Hantzsch and It J. Thompson, Bey., 1908, 41, 3519 ; A., i, 1021.l3 Ibid., 1905, 38, 2511; A., 1905, i, 724.l4 Ibid., 1908, 41, 4186 ; A , , 1909, i, 70ORGANIC CHEMISTRY. 139Manganese and lead ,dioxides give similar results, and potassiumpermanganate and hydroxide furnish benzene, azobenzene, anddiphenyl.The oxidation proceeds most smoothly with alkaline potassiumchromate, when a practically quantitative yield of nitrogen andhydrocarbon is produced.15Althongh the foregoing experiments give no indication of theformation of diazonium salts, yet it has been found possible to obtainthese compounds in excellent yield by introducing chlorine or bromineintolan alcoholic solution of the hydrazine a t temperatures below - 20°.This mode of procedure gives the solid diazonium salt, although asolution of the same can be obtained in glacial acetic acid by addingchlorine or bromine a t OO.16A more convenient method of obtaining the solid diazoniumbromide is first to prepare its perbromide by adding bromide to theaqueous solution of the diazonium salt.The dry perbromide, whenmixed with the corresponding hydrazine in cold alcohol, undergoes thefollowing change : 17R*NBr R*NH R-NBr R*NBrBrNBr= 3 = 3 111 + 3HBr.H I ~ H H h r N 2 1 4-The ortho- and para-aminophenols can be diazotised to diazo-oxides,but the ortho-aminonaphthols, on treatment with nitrous acid in thepresence of mineral acids, undergo oxidation to P-naphthaquinone.It has been found that these aminonaphthols and their sulphonicacids can be diazotised readily, providing that mineral acids areabsent.A solution of 1 -amino-P-naphthol-&sulphonic acid, sodiumnitrite, and sodium chloride~slowly deposits the cyclic diazo-derivative,NaS03*C,,H,<~, and this result is also obtained by treating thesulphonic acid a t 40--50° with sodium nitrite, zinc sulphate, and zinchydroxide; other metallic salts may be used instead of zincsulphate.l*Although diazo-oxides can be obtained from ortho-, para-, and peri-aminophenols, diazoimines can be prepared only from ortho- and peri-ls F.D. Chattaway, Trans., 1908, 93, 270, ls ]bid., 852. l’ Ibid., 958.D.R.-P. 189179, 195228, and 195322 ; A., i, 231, 842140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.diamines. The unsubstituted para-diamines do not give rise to diazo-imines, although certain of their arylsulphonyl and aryl derivativeshave been found to yield p-diazoimides and p-diaxoimines of varyingdegrees of stability.The simplest coml3pund of this group is the explosive phenyl-p-phenylenediazoimine l9 (I) obtained by adding ammonia to thediazonium salt of p-aminodiphenylamine, NH,*C,H,*NH*C,H,.Aeeries of increasingly stable p-diazoimines has been prodnced bygradually introducing nitro-groups into the phenyl nucleus of this base,so that when the trinitrophenyl (picryl) derivative is reached ap-diazoimine (IV) is produced, which is as stable as the p-diazoimides(V) obtained from the arylsulphonyl-p-diamines and mentioned inearlier reports.20(IV. 1 w. )I n the foregoing diagram these derivatives of the still unknownp-diazoiminobenzene are arranged in the order of their stability, whichincreases as the acidity of the substituent group becomes morepronounced. I n spiteof the great difference in stability, the membersof this series all exhibit the two properties which are characteristic ofp-diazoimino-derivatives. They combine additively with P-naphthol,and change quantitatively into the corresponding diazonium salt ontreatment with cold concentrated mineral acids.z1Wydrazones and Hyd~*oxyaxo-compounds.I n considering the diazonium salts, special stress was laid on thefact that these are known only in the aromatic series.The compoundsnow under discussion may be either entirely aromatic or mixedaliphatic-aromatic derivatives.Several important investigations on these substances have beenpublished during the last year, and a t last i t seems likely that someagreement will be reached in regard to their constitution.l9 Annalen, 1888, 243, 282, and Ber., 1902, 35, 895.2o Ann. Report, 1906, 124 and 151.21 G. T. Morgan and F. M. G. Micklethwait, Trans., 1908, 93, 602ORGANIC CHEMISTRY.141The coupling of a diazonium salt with a phenol gives rise to anaromatic hydroxyazo-compound, whilst an aliphatic-aromatic azo-derivative results from the condensation of the diazonium salt withan aliphatic substance containing the group *CH,*CO=.It is in the first place necessary to consider the constitution of thealiphatic and aromatic compounds concerned in these condensations.Aliphatic compounds containing the above group tend to conservethis ketonic configuration, even although in certain reactions thedynamic enolic form comes into play.X*QH, A X*GHY-co YOOH 7Stable ketonic form, Labile enolic form.In the aliphatic series the ketonic form is the more stable.The converse holds with the phenols. Although i t is frequentlynecessary to assume the intervention of the dynamic ketonic(quinonoid) form, this in the aromatic series is the labile condition,and whenever possible the phenol or its condensation product revertsto the stable hydroxylic (benzenoid) configuration.7H:C H 'f?H2CH: C: H *C: 0Labile ortho-$!H:CH*GH ' quinonoid form.CH:CH-&OH ,, CH:CHStable hydroxylic ' cH2<cH:cH>~obenzenoid form.Labile para-quinonoid form.Recent experimental evidence is almost unanimous in demonstratingthat these properties of the aliphatic diketones and aromatic hydroxy-derivatives are shared by the mixed and aromatic azo-compoundsrespectively, the aliphatic-aromatic derivatives tending always toacquire the hydrazone configuration, whilst the purely aromaticderivatives assume almost invariably the hydroxyazo-structure.Aliphatic series :d X*JC;'*N:NR7X*$XN*NHRy*c:o Y*C*OHStable hydrazo-form.Labile azo-enolic form.Aromatic series :$?H:CH*E*N:NR .-) QH:CH*$XN*NHRCH:CH*C*OH CH: CH*C:O -Stable o-hydroxyazo-form, Labile o-hydrazone.Stable p-hydroxyazo-form. Labile p-hydrazone142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYAn investigation of the mechanism of the coupling of diazoniumsalts and aliphatic ketones has been carried out with tribenzoyl-methane, which reacts in its enolic form, since the first product is adiazo-oxide (I) containing the diazo-complex attached to the enolicoxygen. This is proved by the ease with which the diazo-group canbe removed merely by treatment with @naphthol or a-naphthylamine,This diazooxide passes successively into two isomerides, the first, ared azo-compound (11), and the last and most stable, a colourlesshydrazone (111).a76H5 FdH5 72%fi*OXN*C,H, 7:0 Yo70 70C*N:N*C6H5 + C : N N*C6H5I /\ $0 yo-+ C/\70 70C6H5 '6*5 C6H5 C6H511.Red azo-compound. 111. White acyl hydrazone.On hydrolysis, these three isomerides give the same products, namely,'GH5 C6H5I. Yellow diazo-oxide,ethyl benzoate and the hydrazone (IV).C6H5-y0C6H5 * COY:N*NH*C,H,IV. Yellow hydrazone.These results show that in the aliphatic series the final stable pro-duct is a hydrazone rather than an azo-compound.When a very reactive group, such as nitroxyl, is present, the trane-formation of diazo-oxide into azo-compound and hydrazine derivativemay occur simultaneously,o-Dinitrotoluene, C6H5*CH(N0,)2, and its homologues couple withdiazonium salt in alkaline solutions, the first product being a diazo-oxide (I).This substance readily changes into two isomerides, a redazo-compound (11) and a white hydrazine derivative (111). In theinitial coupling, the dinitro-compound is used in the form of its alkalisalt, c6H5*C(N0,):NO*OK.W>C<N?2 ,+ C6H5 N.N*C6H,No2>C:NO*O*N,*C,€€5 11. Red azo-compound.'+ C,H,*CO*~-?f* C6H5 C6H5 I. Yellow diazo-oxide.NO, NO111. White hydrazine.The constitution of the hydrazine derivative is shown by the actionof water, which hydrolyses it first into nitric acid and nitrosobenzoyl-a2 0. Dimroth and M.Hartmann, Ber., 1908, 41, 4012, A., 1909, i, 66ORGANIC CHEMISTRY. 143phenylhydrazine, C,H,*CO*NH*N(NO)*C,H,, this compound beingfinally decomposed into nitrous acid and s-ben~oylphenylhydrazine.~~In the aromatic series the first product, the O-azo-derivative, ordiazo-oxide, has also been isolated in a few cases where the velocity oftransformation into the C-azo-derivative has been lessened by thepresence of substituents in the reactive para-position. p-Bromobenzene-diazonium chloride and p-nitrophenol couple to give p-bromobenzene-diazo-4-oxynitrobenzene, C6H4Br*N: N*O*C,H,*NO,, which at 80"becomes transformed into its isomeride, the red p-bromobenzene-2-azo-4-nitrophenol, C6H4Br0hT:N*C,H:,(NO2)*OH.Auwers 24 is inclined to regard these intermediate O-azo-derivativesas diazonium oxides, but inasmuch as they are produced only in theabsence of acids stronger than acetic acid, it seems preferable toregard them as diazo-oxides, R*N:N*OY, analogous to the diazo-amines,R*N:N *NHY, which are formed under similar conditions and undergothe same change into C-azo-derivatives.In 1907 W.Borsche succeeded in condensing o-nitrophenylhydrazineand 2 : 4-dinitrophenylhydrazine with p-benzoquinone and its homo-logues ; the products were identical with the hy droxyazo-derivativesprepared by coupling o-nitrobenzenediazonium and 2 : 4-dinitrobenzene-diazonium chlorides with phenol and its homologues. 25-----.-.-.......;O H2iN*NH*C,H4*N02 N* NH* c,H,*N02( 0 ):. . /A+ II II\/,\ _..____..\/\ A0 u 04 Unstable hydrazone(not i solnted).N:N* C,H,*NO,(o)11 I + ~O-N,*C,H4*N02 -3- I] I\/ \/633 6HStable p-hydroxyazo-derivative.These condensations are of great interest, because the products areadmittedly p-hydroxyazo-derivatives, formed by a process which oughtto give rise to p-quinonehydrazones were it not for this tendency ofthe aromatic hydroxyl derivatives to conserve their hydroxylicstructure.23 G.Ponzio and G. Charrier, Atti R. Accad. Sci. Torino, 1908, 43, 303 ;24 Ber., 1908, 41, 4304 ; A., 1909, i, 67.25 Borsche, Annalen, 1907, 367, 171 ; A., i, 66.Gazzetla, 1908, 38, i, 526 ; A., i, 482144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.When a p-quinoneoxime is employed instead of the p-quinone itselfin the foregoing condensation, then the primary product can beisolated.:.~'~..."H~~N.NH.C,H,.NO, . N*NH*C6H4*N0,i\-+ v,, . . . . . . . .It I'\/II IIgOH NOHStable p-quinoneoximehydrazone.I n this case the phenolic OH is replaced by NOH, so that the strivingis\ /""\C:O to become -(J/.-*-\ of thearomatic residue Cnon-existen t.To the foregoing evidence may be added the closely relatedtransformation of p-benzoquinonebenzoylphenylhydrazone into benzene-azo-p-phenyl benzoate under the influence of cold potassium hydroxide,already referred to in last year's Report (p. 126).The production of P-benzeneazo-a-naphthyl benzoate from as-benzoyl-phenylhydrazine and P-benzoquinone simply means that the ortho-quinonehydrazones are even less stable than the paraquinone-hydrazones and pass spontaneously into ortho-azo-derivatives.The reduction of this /3- benzeneazo-a-naphthyl benzoate has beencompared with that of its isomeride, a-benzeneazo-P-naphthylbenzoate ; the former gave benzanilide, aniline,, and N-benzoyl-2-amino-a-naphthol, whilst the latter yielded benzanilide, aniline, andN-benzoyl-1 -amino-P-naphthol.27 The corresponding acetates behavesimilarly on reduction.The reduction of benzene-o-azo-p-tolyl benzoate leads to the hydrazo-derivative, which, on heating in acetic acid, regenerates the azo-derivative and yields simultaneously N-benzoyl-o-amino-p-cresol andaniline : 28/ \...../aH3*C6E4<OH NHBz + Ph*NH2.Benzanilide was never obtained in this reduction.Bearing in view the fact that acyl groups readily shift from oxygent o nitrogen in aminophenols, Auwers considers that the foregoingThere is evidence that this compound can assume the dynamic azo-form,N0,*C,H4*N:N*C,H4'NH*OH, in certain of its reactions, as, for example, oxidation(Zoc.eit., p. 148).27 Be?-.$ 1908, 41, 403 ; A., i, 228.28 K. Auwers and M. Eckardt, Annulen, 1908, 359, 336 ; A , , i, 480ORGANIC CHEMISTRY. 145results favour the assumption that these esters are really azo-derivatives and not o-quinoneacy 1 h ydrazones.Mercuric acetate was shown by Dimroth to condense with phenolsand aromatic amines, entering the unsubstituted para- and ortho-positions with reference to the oxygen and nitrogen atoms respectively.On this account it has been employed in the study of hydroxyazo-compounds, for, as will be seen from the following formulae, thenumber of mercuriacetate groups introduced into the azo-compoundshould be a criterion of its constitution :X Xp - and o-Hydroxyazo-derivatives. p - and o-Quinonehydrazones.Considered as an azo-derivative, the para-compound (I) shouldcondense with not more than two mercuriacetate groups, whilstas hydrazone it should form a tri-substit uted mercuriacetate.Theortho-compound (11), i n its hydrazo-form, should also take up threemercuriacetate groups, but as an azo-derivative it should onlycondense with one molecule of mercuric acetate. I n every caseexamined, the result corresponded with the hydroxyazo-structure,both in the ortho- and para-~eries.2~These results, like the other chemical evidence already cited, are allin favour of the view that the constitution of both ortho- and para-hydroxyazo-derivatives is what their usual designations imply, andthat these substances have not in ordinary circumstances a hydrazonestructure.The spectroscopic evidence, as interpreted by Tuck, is, to acertain extent, against this view and in favour of the assumption thatthe ortho-hydroxyazo-compounds and their acyl derivatives have thequinonehydrazone constitution.Both Auwers and C. Smith, however,take exception to the comparisons instituted between the absorptioncurves, the former referring to the diEerence between the curve forbenzoquiaonebenzoylphenylhydrazone and those for a set of azo-derivatives, whilst the latter asserts that the curve for benzeneazo-p-tolyl benzoate, presumably a hydrazone, resembles that of benzeneazo-phenol, admittedly an azo-compound, more than t h a t of the foregoingquinonehydrazone.From the chemical evidence now available, it is permissible todeduce the general rule that a hydroxyazo-compound will be an azo-15) C.Smith and A. D. Mitchell, Trans., 1908, 93, 842.KEP.-VOL. V. 146 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.derivative or a hydrazone according as to whether its oxygenatedgenerator is an enol or a ketone respectively.The case of 2-pyridone (IV) is of interest in this connexion, forthis substance, which differs from the phenols in not giving the ferricchloride and nitrosoamine colorations and in not yielding acetyl andnitroso-derivatives, nevertheless forms an azo-compound, 5-benzene-azo-2-pyridone (I1 or 111), with benzenediazonium chloride.Theorientation of the substituents in this compound is established by thefollowing series of operations, starting with 6-hydroxynicotinic acid(I), a substance of known constitution : 30C,Hb*N:N(\ /\:o f- I/:.. c6H5*N20 NH-+ ,)OH orN NH(11.) (111.) (IT. 1This azo-derivative and the isomeric benzeneazo-3-hydroxypyridinemerit further examination from the point of view of the constitutionof hydroxyazo-compounds.Although the balance of chemical evidence is in favour of the viewthat all aromatic hydroxyazo-derivatives have the azo-structure, thequestion of the nature of their salts with the mineral acids next arises.Some years ago Hewitt showed that, on nitration, benzeneazophenolitself behaves in accordance with its hydroxyazo-c0nstitution,3~ and inthis respect differed from its sulphate, which behaves as if it were aquinonehydrazone.More recently it has been found that benzeneazophenol andits ethoxy-derivative, benzeneazophenetole, both admittedly azo-compounds, have similar absorption spectra in concentrated hydro-chloric acid.32 Accordingly the formula for the salts of benzeneazo-phenol must be applicable to the salts of benzeneazophenetole, and atthe same time should account for the chemical properties ofbenzeneazophenol sulphate.After discussing several formula?, Foxand Hewitt, who have prepared and examined spectroscopically thesalts of a series of azophenols and their ethyl ethers, decide onthe following structure : /-)NHqq: /=>:0<8(4H,)L \= c130 W.H. Mills and S. T. Widdows, Trans., 1908, 93, 1373.31 Trans., 1900, 77, 99. Tuck, ibid., 1907, 91, 450ORGANIC CHEMISTRY. 147The compounds having this constitution are characterised spectro-scopically by strong and persistent absorption in the yellow and greenand chemically by behaving towards substituting agents as quinone-hydrazones.33Heterocyclic Rings contain,ing Oxygen.The Cotmarin, Group-The coumarin condensation with malic acidor ethyl acetoacetate and the substituted phenols has been studied, theresults showing that phenols containing alkyl, hydrbxyl, or dialkyl-amino-groups in the positions indicated below give good yields of thecorresponding coumarins.XX()OH\//)OHXI vChlorine, as a substituent in these positions, has a similar effect,but to a less appreciable extent. The introduction of nitro-, carboxy-,or carbethoxy-groups prevents conde~sation.3~The condensation is affected considerably by the strength of thesulphuric acid employed; when 73 per cent.acid is used, a satisfactoryyield of 4-methylcoumarin may be obtained from phenol and ethylacetoacetate, otherwise the amount produced is very ~ m a 1 1 . ~ ~One of the most interesting, and still only partly explained, reactionsof coumarin is its hydrolysis into coumarinic and o-coumaric acids.When treated with sodium ethoxide, coumarin and 7-methylcoumnrinyield respectively ethyl o-coumarate and ethyl 4-methyl-o-coumarate.But under these conditions, 4 : 7-dimethylcoumarin, which containsone methyl group in the lactonic ring gives rise to more complexproducts, namely, 3 - [ 2 : 5-dimethylhydrocoumarilyl] - 4 : 7 - dimethyl-coumarin and 1-[2 : 5-dimethylhydrocoumarilyl]-2 : 5-dimethyldihydro-coumarone (11) respectively.A molecular proportion of the p-4-di-methylcoumaric acid produced by hydrolysis condenses with unaltered4 : 7-dimethylcoumarin, and the product then undergoes rearrange-ment 36 and a coumaryl ring is produced (I). The second product isformed from the first by hydrolysis and loss of carbon dioxide.The interaction of 4 : 6-dimethylcoumarin and sodium ethoxideleads t o the production of similar products differing from compounds(I) and (11) only in the position of the methyl substituent in thebenzene ring.The reduction of coumarin with zinc dust and alkali hydroxide33 Fox and Hewitt, Trans., 1908, 93, 333.34 A.Clayton, ibid., 2018.36 F. Peters and H. Simonis, Ber., 1908, 41, 830 ; 8.) i, 339.36 K. Fries and W. Klostermann, Annalen, 1908, 362, 1 ; A., i, 820.L 148 ANNUAL REPORTS ON THE PBOGRESS OF CHEMISTRY.CMeCMeleads to melilotic acid as the main product, and, in addition, to twoby-products, which are stereoisomeric a- and P-tetrahydrodicoumaricacids, the isomerism of which resembles that of the symmetricallydi-substituted succinic acids, and persists even when they are condensedinto tetrahydrodicoumarins.f\iCH2--- ~H-~H--cH,/\ I I\/OH HO*OC CO*OH HO\/a- and &Isomeric acids.Ia- and B-Tetrahydrodicoumarins.4 : 7-Dimethylcoumarin behaves differently on reduction, and givesrise to three products : 2-hydroxy-4-methylphenyldimethylcarbinol (I)(hydroxythymol), 2-hydroxy-a-4-dimethylstyrene (Il), and thymol(111)./\CM~,*OH /\C M 8: CH, /\CHMe2MP()OH Me(,)OH ~ e j / o a(1.1 (11.1 (111.ORGANIC CHEMISTRY.149The second product also exists in a polymeric bimolecular form.These vinylphenols and their polymerides may be produced bydistilling o-coumaric acid and its homologues under reduced pressure.The simplest member of the series, o-vinylphenol (o-hydroxystyrene),prepared from o-coumaric acid itself, readily polymerises.The bimole-cular form is insoluble in alkali hydroxides, and becomes depolpmerisedwhen distilled under the ordinary pressure, although under 15 mm.it passes over unchanged.37As the coumarins aro colourless, and do not condense with eitherhydroxylamino or phenylhydrazine, whilst the thiocoumarins areyellow and yield oximes and phenylhydrazones, it has been suggestedthat coumarin has the modified structure (I), whilst thiocoumarinretains the configuration (11) generally attributed to coumarin : 3876H4-0 CH:CH*C ' '> 7GH4-O>cs.GKCHThe FZavone Gv-oup.The residue *C:C*CO* is often associated with the development of . .colour, and i t may occur in compounds in four different ways; both*C:C* and GO* may be present in a ring, or both may occur in achain, or one may be in the ring and the other in the chain.As thecase of the ethyl linking in the ring (" cyclostatic ") and the carboxylgroup in the chain ("streptostatic") has not been studied,l-hydroxybenzoylcoumarone, a compound having the requiredstructure, has been synthesised from coumarilic chloride and phenolby the action of aluminium chloride,. .The colour is absent from the alkyl derivatives, The methylcompound is synthesised in the following manner : salicylaldehydeand p-methoxybenzophenone give 2-hydroxy-4'-methoxychalkone,OH*C,H,*CH:CH*CO.C,H,.OMe, a yellow substance containing bothchromophores in the streptostatic condition.The acetate of this compound yields a dibromide, which on heatingwith alcoholic potash furnishes the required compound, l-methoxy-benzoylcoumarone,3937 K.Fries and G. Fickemirth, Ber., 1908, 41, 367 ; A., i, 160.38 A. Clayton, Trans., 1908, 93, 524.39 F. Zwayer and 8. Jon Hostanecki, B e r . , 1908, 41, 1335 ; A., i, 443150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,The two chromophores are cyclostatic in the allied group of flavones,the hydroxy-derivatives of which exhibit colour, whereas their alkyland acyl derivatives are colourless.A series of flavones have been synthesised from orcacetophenonedimethyl ether and the isomeric isoorcacetophenone dimethyl ether,these ethers being produced by condensing acetyl chloride and orcinoldimethyl ether. One example of this synthesis will suffice to indicatethe general method.Orcacetophenone is condensed with methylo-methoxybenzoate, yielding 2 : 6 : 2’-trimethoxy-4-methylbenzoylaceto-phenone (I) ; this intermediate product, when boiled with concentratedhydriodic acid, condenses into 1 : 2’-dihydroxy-3-methylflavone (11)(greeni~h-yellow).4~A 0OH COBradin, Haematoxylin, and their Derivatives.The culminating point in a long series of researches on brazilin andhaematoxylin has been reached this year with the demonstration of theconstitution of these two substances and of the colouring matters,brazilein and hamatein, into which they are converted by oxidisingagents.Brazilein and hamatein are respectively the colouring matters ofbrazil-wood and logwood, both of which find extensive application indyeing; they stand in the same relationship to brazilin and haematoxylinas p-benzoquinone does to quinol.A s in both cases the quinol derivative is more amenable to chemicaltreatment than the quinonoid substance, the problem of ascertaining theconstitution of these substances has mainly been worked out withbrazilin and haematoxylin, The f ormer of these substances containsthree, and the latter four, hydroxyl groups, and it was found advisableto protect these by methylation before systematically breaking downthe compounds by oxidation.Trimethyl brazilin yields on treatment with potassium permanganatea number of acidic substances, all of which are of great importance intracing out a skeleton formula for the parent substance.The follow-ing are two pairs of these oxidation products.MeO/\O* CH,* CO,H CO,H/\OMeCO,Hi ’OMe2-Carboxy-5-methoxyphenoxy- sn-Hemipinic acid.40 J.Tambor, Ber., 1908, 41, 787, 793; A , , i, 349, 358.{,!CO,H \/acetic acid151 ORGANIC CHEMISTRY.0 CO,H/\OMe M ~ o ( \ ~ \ c H , CO,HCH,!,)OMe\,/\/(&OH)'CH2'CO2H 2-Carboxy-4 : B-dimethoay- co phenylacetic acid.Brazilic acid.Bearing in mind that the empirical formula of trimethylbrazilin isC,,H&,, a careful consideration of the oxidation products led to thegraphical formula for trimethylbrazilin (I) :0 0MeO/\/\ CH, HO/\/\CH, I I 'C(OH), \/\/I IC(OH)\CH CH2\-// \\.-/ \-./\A/ CHMe0 OMe HO OHI. 11. Brazilin.It will be seen that this constitution agrees with the formation ofthe foregoing oxidation products.I n confirming this formula, all themore important degradation products of trimethylbrazilin have beensynthesised with the exception of brazilic acid.O*CH,*CO,Et 0. CH2*C0,HMeof\(\/\ co co --+ co\-// \\-/Me0 OMeEthyl methoxyphenoxyacetateand m-hemipinic anhydride.\ CO2H/-\.\-/Me0 OMeI.M~o{) 0. CH, CO,H MeO(\OH1 \)\ /O-\CH CO\ / <I? Me0 OMe I-\ \-/Me0 OMe11152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Of these syntheses, one of the most important is that of brazilinicacid (I), an oxidation product of trimet hylbrrtzilin, which on reductionchanges into the lactone (11) of dihydrobrazilinic acid. Both thesesubstances have been synthesised in the manner indicated on p. 151.A similiar synthesis, using m-hemipinic anhydride with pyrogalloltrimethyl ether instead of the foregoing resorcinol dimethyl ether, ledby a precisely comparable series of reactions to the lactone (111) ofdihydrohamatoxylinic acid :Me0MeO{)O*CH2*C02H\/O-\\ACH COMe0 OMe111.a result which proves that hamatoxylinic acid and haematoxylin mustbe represented respectively by formuls IV and V.41Me0 HO 0MeOAO*CH2*C02H H O / y \ C H 2L \ l C ( O R ) \I t\/\ 'CH \CH, co\ C O P \-//-\ / \\-/ \-/Me0 OMe HU OHIV.V. Hcematoxylin.Brazilein has the empirical formula C,4H,205,2H20, losing water a t130-140O. On methylation it yields trimethylbrazilein (11) andtetramethyldihydrobrazileinol, the former of these on treatment withdilute aqueous potassium hydroxide becomes hydrated to trimethyl-brazileinol (I) ; the tetramethyl derivative has the configuration (I)with methoxyl in place of the lower hydroxyl :0 0MeO/\/\QH, I MeOf\f\FH,\/\/C(oMei \\\ \\2\)\,C(OM")\?(OH) CH, %-- c: CH2/ >- / >- \--> Me0 a MeU OH1.11.41 W. H. Ytdtin, jun., and R. Robinson, Tmws., 1908, 93, 489ORGANIC CHEMISTRY. 153The trimethyldihydrobrazileinol is reconverted into trimethylbrnzileinon heating, this reversible change being quite comparable with thechange of trihydroxytriphenylcarbinol (111) into aurin (IV), andvice versa.111.-+ f-H O f \ r ()OHC'\/\/\/\/-\\-/ ..0IV.The close relationship existing between brazilin and hsmatoxylinindicates that hamatein is hydroxybrazilein. The behaviour ofhamatein on methylation fully justifies this hypothesis. The colouringmatter is converted into tetramethylhaematein (11) and pentamethyl-dihydrohsemateinol ; the former of these, when digested with dilutepotassium hydroxide, is hydrated to tetramethyldihydrohzmateinol (I),a change which is reversed on heating :Me0 0 Me0 0M ~ o < ) / \ ~ H ~ M e O ( \ / \ C H ,\/\/c(oMe)\\--/u CH2\/ \ /C(OMe)\C(0H) OH, 2\-.-.-)- /\ tjMe0 OH Me0 0I.11.These reactions, together with more confirmatory evidence, lead tothe following formulz for brazilein (I) and htlematein (11) : 420 HO 0I. 11.The synthesis of brazan, a substance obtained from brazilin, hasP. Engels, IT. 1%. Pcrkin, jun., and R. Robinson, Trans., 19OS, 93) 1.115154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been effected in the following manner from resorcinol and 2 : S-dichloro-naphthaquinone : 430 0 00 0 00.--with zincBrazan (o-phenylene-BB-naphthylens oxide).Pyyanol Salts.I n connexion with the experiments on brazilin and hzematoxylin,the synthesis and coustitution of certain pyranol salts have beenstudied. As a typical example of these compounds, one may take theproduct obtained by condensing either resorcinol and benzoylacet-aldehyde or P-resorcylaldehyde and acetophenone.The hydrochlorideof this pyranol contains an additional molecule of water, and may berepresented by the following formulze :H C1\/0 oc1I. 11.The balance of evidence is in favour of the second formula, whichrepresents the salt as 7-hydroxy-2-phenylbenzopyranol( 1 : 4)anhydro-hydrochloride with one molecule of water of crystallisation.All thehydrochlorides examined could be formulated in this way, exceptingthat some contained even more water of crystallisation.The platinichloride of the above pyranol was obtained in bothC3 S. yon Kostanecki and V. Lampe, Ber., 1908, 41, 2373 ; A., i, 671ORGANIC CHEMISTRY. 155hydrated and anhydrous (111) forms, and all the ferrichlorides describedwere free from wafer.c1 FeCl,0 0/ \ A C - A I I I ICH CH,111. IV.Formula (IV), for example, represents the anhydroferrichlorideof 2 : 3-indenobenzopyranol(l : a), the free base having the structureindicated by (V) :FeC14/\0 1 1/\0 0 1 1\A/\/I l l\/\/\/CHf /\/\c /\ /\A/\/I I I 1 I I I I ICH*OH CH2 CH*OHV.VI. VII.The ortho-quinonoid formula is adopted for these salts because theyare coloured, and in every way comparable with those of naphtha-xanthhydrol. Formulae (VI) and (VII) represent respectively this sub-stance and its anhydroferrichloride. It will be seen that the hetero-cyclic nuclei of 2 : 3-indenobenzopyranol( 1 : 4) and naphthaxanthhydrolare similarly constituted (V and VI), and their salts, for example,the anhydroferrichlorides (IV and VII), are formed in a similarmanner with elimination of water. Now the 8 naphthaxanthhydrolanhydroferrichloride must be formulated as an ortho-quinoid whetherthe double linkings are represented as in (VII) or whether they areturned towards the naphthalene nucleus.Accordingly, it may fairlybe assumed that the same ortho-quinonoid structure exists in thesalts of 2 : 3-indenobenzopyranol(l : 4).oc1I i I (yellow)156 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The action of hydrogen chloride on 2-hydroxybenzylideneaceto-phenone (I) under different conditions affords a noteworthy example ofring formation with production of oxonium salts. Hot concentratedhydrochloric acid acting on the ketone in glacial acetic acid produces2-phenylbenzopyranol anhydrohydrochloride (II), a very soluble saltisolated in the form of its platinichloride, (C,,H,,OCl),PtCl,.Dry hydrogen chloride and the ketone interacting in etherealsolution give rise to the dichloride (111) (the hydrochloride of2 -p henyl benzopyranol anhydrohydrochloride).The original memoir should be consulted for further examples ofthese interesting pyranol salts, and for a fuller exposition of thearguments adduced in favour of their constitutional f o r m u l ~ .~ ~A closely allied series of oxonium salts has been produced fromdisdicylideneacetone (I) ; this substance when treated with alcoholichydrochloric acid undergoes condensation to a red oxonium chloride(II), which furnishes a brick-red ferrichloride, Cl7H,,O2*FeCI4.Dilute aqueous sodium hydroxide converts the Z-o-hydroxystyryl-benzopyrylium chloride (11) into the sodium salt, Z-o-hydroxystyryl-benzopyranol-2 (III), from which, however, the free carbinol couldnot be isolated, as diluto acids induce further condensation with theformation of a substance containing two heterocyclic nuclei.Thisso-called dibenzospiropyran (IT) is hydrolysed by strong acids to theoxonium salt, and by alcoholic soda to the original disalicylidene-acetone (J).45_/cH:cH \ c o * a ~ : CH-C,H,*OH -+ / \\=/I (yellow).71-/--\c*cH: CH.C,H,*OH // \-O(-jl/\=’ \=/ I1 (red).i? ,CH:CH,111 (yellow solution).Indigotin ccnd Indigoid Dyes.The investigations recently carried out on the dyes of the indigogroup fall chiefly under four headings : (1) improvements in thephenylglycine synthesis of indigotin, (2) the production of halogenated44 W. H. Perkin, jun., R. Robinson, and M. R. Turner, Trans., 1908, 93, 1085.45 11. Deckcr and H.Felser, Ber., 1908, 41, 2997 ; A . , i, 906OKGANlC CHEMISTRY. 157indigotins, (3) the synthesis of indigoid dyes containing sulphur,(4) the synthesis of more complex dyes, chiefly of the anthraceneseries, which are capable of employment in the hyposulphite vat.1. Modifications in the process of synthesising indoxyl by heatingphenylglycine with alkalis have formed the subject of many recentpatents. The addition of magnesium powder t o the fused mixture ofphenylglycine with sodium and potassium hydroxides and barium oxidemore than doubles the yield of indigotin subsequently precipitated byaerial oxidation from aqueous solutions of the melt. E'usion undergreatly reduced pressure at 200--230° gives a n 80 to 90 per cent.yield of indigotin.462.A well-defined chloroindigotin, C16H902N2Cl, has been preparedby direct chlorination of indigotin suspended in hot nitrobenzene.Bromination in the same medium has led to the formation of a tri- andtwo tetra-bromoindigotins, and more highly halogenated indigotinshave been produced, containing both chlorine and bromine. Thesubstitution of hydrogen by halogen in indigotin increases thebrilliancy and fastness of the dye, and it is noteworthy that theleuco-derivatives of these halogenated indigotins differ from indigo-white in being coloured, the shade varying from yellow to brown.47The sulphonic acids of the halogenated indigotins have also beenprepared ; their tinctorial properties differ considerably from those ofindigo carmine.483. 2-Hydroxythionaphthe11, an important compound in the synthesisof thioindigoid dyes, is obtained, together with its carboxylic acid,C,H,<;(O~)>CH or c,H~<~-?>cH,,by condensing chloroacetic and thiosalicylic acids or their esters inalkaline solutions and then heating the intermediate product, carb-methoxy-o-thiobenzoic acid, C02H*C6H4*S*CH2*C02H, with sodiumhydroxide a t 180'.Oxidation of 2-hydroxythionaphthen, or itscarboxylic acid, results in the formation of a red colouring matter,thioindigotin or 2 : 2'-bi~thionaphthenindigotin,~~Thionaphthen (I), the parent substance of this group of dyes,is now readily obtained by reducing the synthetical 2-hydroxythio-naphtha with zinc and glacial acetic acid :I. 11. 111.4(i L. Lilienfeld, D.B.-P.189021, 195352 ; A., i, 371, 797.47 D.11.-P. 193438, 193970, 193971, 195085, 195291 ; A, i, 468, 695, 798.43 C. G. Scliwalbe and H. Jochlieim, Ber., 1908, 41, 3798 ; A . , i, 1019.D.R.-P. 192075, 194237, 194254 ; A . , i, 451, 672158 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.2-Hydroxythionaphthen yields 1 : l-dibromo-2-ketodihydrothio-naphthen (11), and this, on treatment with lead acetate, gives rise tothe intensely yellow thionaphthenquinone (111). Like hydroxythio-naphthen, the dibromide and the quinone are employed in thesynthesis of thioindigoid d ~ e s . 5 ~The interaction of thionyl choride, and various styrene derivatives,at 180-270°, leads to the formation of thionaphthen compounds,up-dibromostyrene giving rise to hexachlorothionaphthen,a substance containing only carbon, chlorine, and sulphur.51furnishes thioindirubin, 2 : 3-bi~thionaphthenindigotin,~~The condensation of 2-hydroxynaphthen and thionaphthenquinoneDyes containing indigotin and thionaphthen nuclei have beenIsatin and hydroxythionaphthen give rise to thioindigo- synthesised.scarlet, 2 - t hionaph then-3-indole-indigotin,The isomerides, 2-thionaphthen-2-indole-indigotin and 3-thionaph-then-2-indole-indigotin, are obtained from indoxyl with thionaphthendibromide and thionaphthenquinone respectively.The application of peri-carboxymethylthionaphthoic acid,1 8C0,H *CH,*S*C,,H,- CO,H,in the preparation of blue thioindigoid dyes has been patented.534.Certain complex anthracene derivatives containing nitrogen havethe property of yielding colouring matters suitable for the hyposulyhitedye vat.54Flavanthren, which possesses this property, may be convenientlyconsidered a t this stage.This yellow colouring matter is remark-able because it yields a series of reduction products, most ofwhich are more intensely coloured than the original substance. Theprogressive reduction of flavanthren indicates the formation of sevenreduction products, five of which have actually been isolated.A. Eezdzik, P. Friedlander, and P. Koeniger, Ber., 1908, 41, 227 ; A , , i, 200.51 G. Barger and A. J. Ewins, Trans., 1908, 93, 2086.6a P. Friedlander, Monatsh., 1908, 29, 359, 375 ; A., i, 673.53 D.R.-P. 198050 ; A , , i, 797.D.R.-P. 197554 ; A., i, 807ORGANIC CHEMISTRY.0159OR0Flavanthren (yellow).OHa-Hexahydroflavanthren hydrate(blue).IJ/OHFlavanthrinol hydrate (blue).tiDihydroflavanthren hydrate (blue).OH/\A/\I I I I+--OHa-Te t rah ydroflavan thren hydrate(not isolated, brown solution).'xHFlavanthrine hydrate (greenish-brown).The foregoing diagram represents, according to Scholl, the successivestages in the reduction of flavanthren.The products thus isolatedcontain water of hydration, which is assumed to be attached to twocarbons united by a double linking in one of heterocyclic rings.Dihydroflavanthren (green), a-hexahydroflavanthren (blue), flavan-thrinol (blue), and flavanthrine (brown) have, however, all beenobtained in the anhydrous condition by expelling the water a t150--2OOO. This dehydration is not accompanied by any markedchange in colour. The di-, a-tetra-,and a-hexa-hydroflavanthren hydratesare obtained by alkaline reducing agents, flavanthrinol is formed byheating a-hexahydroflavantbren hydrate, and flavanthrine hydrate isproduced by reducing flavanthren or the foregoing hexahydro-hydrat160 ANNUAL ItEPOltrIS ON THE PlWGEESS OF CHEMISTRY.with red phosphorus and hydriodic acid a t 210'.A t 170°, flavan-thren, when reduced, gives rise to another tetrahydroflavanthren, towhich in solution the following constitution (I) is ascribed, althoughwhen precipitated it probably exists in the ketonic form (11). ThisP-tetrahydroflavanthron cannot be hydrated, for it already containstwo hydrogen atoms in the position occupied by water in the otherreduction products.0 OH ..0I.B-Tetraliydroflavanthrenred in solutioii (e~iol).Acids. s t--organic solvents011. Green precipitated ketonicform.This production of intensely coloured .reduction products from afaintly coloured substance is a striking example of the rule that thepartial conversion of the chromophores of a colouring matter intoauxochromic groups brings about an intensification of the colour. Thepartial reduction of yellow picric acid to dark brown picramic acid isa case in point. This generalisation accounts for the colour of theintermediate reduction products OE flavanthren. The colour of thefinal product, flavtznthrine, like that of meso- and P-anthramines, maybe referred to the fact that they are all derivatives of anthracene, ahydrocarbon which must be regarded as having a chromophoric ortho-quinonoid constitution.55Oxazine Group.The oxazine dye produced by the condensation of nitrosodimethyl-aniline and methyl gallate is termed '' prune )' (I), and an interestingseries of derivatives may be obtained from i t by the action of anilineand similar aromatic amines. Pruneanilide was formerly supposed tobe an additive compound of the oxazine and aniline, but it has now beenshown to be a substituted derivative, the dye and aniline condensing inmolecular proportions while the hydrogen which should be displacedis employed in reducing another molecule of prune to its leuco-deriv-ative.Actually, the yield of pruneanilide was doubled by blowingair through the mixture, A similar result was obtained with ccelestinblue B [the oxazine (11) from nitrosodimethylaniliue and gallamide],55 R.Scholl, Bcr., 1908, 41, 2304, 2534 ; A,, i, 696, 740ORGANIC CHEMISTRY 161the yield of anilide being considerably increased by the introductionof air.0 O H 0 OHThe constitution of pruneanilide has been demonstrated by con-densing nitrosodimethylaniline and methyl dibromogallate,C, Br,(OH),* CO,Me,when bromoprune is produced, which must have the following con-stitution (111). When this bromoprune is heated with an alcoholicsolution of aniline, pruneanilide results. Accordingly the anilino-residue occupies the position adjacent to the quinonic oxygen (IV).The anilide of ccelestin blue 13 has a similar constitution.660 OH.2 111.2% Axine Group.The relationship between azines and quinoxalines ( ' I ethopyrazines ")is well illustrated by the conversion of the two isomeric a/?-dinaphth-azines into bases of the quinoxaline series.s-ap-Dinaphthazine is first/-\ /-\\-/\NNI II>-< --3 \ - A N >-<N/ II\/\/\ \/\/\I l l 01 I 1\/\/ \/\/0co, €€"\/56 E. Grandmougin and E. Uodmer, Ber., 1908, 41, 604 ; A.. i, 289.REP.-VOL. V. 162 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.oxidised by chromium trioxide into diketo-s-ap-dinaphthazine. Thissubstance, when heated with concentrated sodium hydroxide, gives riseto 2-phenylnaphthaquinoxalinecarboxylic acid, which, on heating, losescarbon dioxide, and yields 2-phen ylnaphthaquinoxaline (" 2-phenyl-naphthapyrazine ").as-ap-Dinaphthazine is converted into 3-phenylnaphthaquinoxaline by a precisely similar series of changes.57The prasindones are a group of hydroxyazonium bases containing ahydroxyl group in the para-position with respect to the azoniumnitrogen. In some cases, water is eliminated from the azonium andphenolic hydroxyls, so that the base exists in the form of an anhydride.An attempt to prepare the simplest member of this series has not beensuccessful. o- Aminodiphenylamine has been condensed with 3-amino-4-hydroxy-o-benzoquinone, and the following series oE changes hasbeen realised, but it was not found possible to isolate the basecorresponding with the final product : the prasindone nitrate.NI I'6*5 N/\C P , NO,When 2-anilino-l-aminonaphthalene was substituted for o-amino-diphenylamine in the foregoing condensation, the synthesis was carrieda stage further, but in this case the prasindone hydrate, althoughactually isolated, could not be dehydrated.5s/\ C6H5 OHFurther evidence in favour of Kehrmann's betaine formula forisorosindone (I) has been obtained by converting it into the chloride of57 0.Fischer and E. Schindler, Bar., 1908, 41, 390 ; A., i, 221.62 F. Kehrmann and R. Schwarzenbach, ibid., 472 ; A., i, 297ORGANIC CHEMISTRY. 163its acetyl derivative (IV) by two distinct processes. In one thecompound is simultaneously reduced and acetylated by zinc dust andacetic anhydride, the product, a diacetyl leuco-derivative (II), beingthen oxidised to the chloride.I n the other process the isorosindone istreated with acetic anhydride alone, when the acetate (111) of itsacetyl derivative is directly produced, and can be converted into thecorresponding chl0ride.5~/\C,HS 0-CO-CH,(111.)Carboxonium dyes with a structure somewhat similar to thepreceding substances have quite recently been obtained by condensingm-acetylaminophenol and benzotrichloride in nitrobenzene a t 1 Go.One of these is acetylaminophenylfluorone (I), to which an ortho-quinonoid structure is ascribed. The non-acetylated base is of greatCPh CPhinterest, as on eliminating the amino-group, phenylfluorone (11) isobtained, which is the chromogen of fluorescein.Hydroxyphenylfluorone(111), produced by replacing the amino-group by hydroxyl, is identicalwith resorcinolbenzein, and is remarkably like fluorescein, which, as its69 F. Kehrmann and K. L. Stern, Beer., 1908, 41, 12; A . , i, 220.Y 164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,carboxylic acid, should, if Kehrmann's formulation be accepted, havethe formula (IV).C,H,*CO,HCPh 6(111.) (IV, 1The other condensation product is diacetylaminophenorosaminechloride (V), which yields an unstable colour base changing rapidlyinto a colourless, stable form. Hydrolysis leads to the simplest rosamine,tho salt of which is represented by (V.I).,OCPh CPh/\A/\ /\A/\I l l\/\//\/ NHAJ I I JNHA~ NH,(/\//\/NH2OCl oc1The Boaaniline Group.The researches of Baeyer and Villiger have shown that many basesof the triphenylmethane group exist iu two forms, one colourless andthe other coloured. There is little doubt that the colourless baseshave the carbinol formula, HO*C(C,H,NR,),, but some uncertaintystill exists as to the nature of the coloured amines.I n many casesthe coloured amine is the dehydrated imino-base, which has only beenobtained pure when the amino-groups are phenylated, as inC,H5N :C6H4:C( C6H,-NH*C,H5),.The metliylated rosanilines have as yet only been isolated in thecolourless carbinol form, and although the observations of Hantzschand Osswald indicate that isomeric quinoneimonium bases of thisseries may exist, these substances have not been obtained in a state ofpurity.Naphtho-blue, NMe,CI:C,,H,:C(C,H,*NMe,),, has yielded its basein two isomeric forms, the colourless cnrbinol (I) (m.p. 155') andthe dark green, quaternary ammonium hydroxide (11) (m. p.26 I"), which may possibly have the alternative pseudo-ammoniumformula (111).76H4*WH8)2 y,H,*N(CH3)2H 0.7 C,,H,*N (C HJ2(1.1~:C,,H,:N(CH,),*OHC,H, *N (CHJ 2(11.)CGH4*N(CH3)260 F. Kehrmann and 0. Dengler, Ber., 1908, 41, 3440 ; A., i, 1002ORGANIC CHEMIS'I'RY. 165(111.)Victoria-blue R, NHEtC1:C,oH6:C(CsH4*NMe2)2, has also given riseto a coloured as well as a colourless base, but these substances are notisomeric. The colourless compound is the carbinol (I) (m. p. 170°),but the coloured substance is the anhydrous imino-base (11) (m.p.1 9 2 O ) .7GH4*N(CH3)2 VBH, * N ( C H 3 ) 2HO.Q*CI,H6*NH*C9H, 7 : C IoHG: N C 2 H,C6H4*N(CH3)2 C6H4*N(CH3)2(1.1 (11.1The composition of these two pairs of diphenylnaphthylmethanebases has been confirmed in each case by complete analyses,6l whichshow that the substances were obtained in a fairly pure state.The corresponding diphenylnaphthylmethane colouring matter,containing methyl instead of ethyl in the foregoing formulz, givesrise also to the corresponding colourless carbinol and the colouredim ino-base.All attempts to isolate the quinonoid form of the bases from crystal-violet, malachite green, and o-chloromalachite green were unsuccessful ;although the coloured bases could be seen in solution, they were toounstable to be anaiysed.G2One of the nitration products of thiodiphenylamine is the dinitro-sulphoxide (I), which has been taken as the starting point in thesynthesis of 8-phenylphenazothionium hydroxide and its salts.Whencondensed with phenol or phenetole in concentrated sulphuric acid, thesulphoxide gives rise t o the sulphate of a phenazothionium base, thechloride of which is represented by formula (11).8-Phenetyl-3 : 3'-dinitrophenazothionium chloride undergoes hydro-lysis to the base 8-pbenetyl-3 : 3'-di&trophenazothionium hydr-oxide (111), but when treated with aqueous alkali hydroxide theanhydride (TV) (anhydro-S-phenetyl-3 : 3'-dinitrophenazothionium) isset free.til I<. Noelting aiid K. Yhilil)p, Bcr., 1908, 41, 579 ; A., i, 295.y2 Bid., 3908 ; A., 1909, i, 61166 ANNUBL REPORTS ON THE PROGRESS OF CHEMISTRY.NH NH/\C1 C,H,*OEt ''/ 11.Green salt.1L *7 $HydrolysisN N,A/\/\ /A//\/\HO,N:I I I I\ / \ / V N 0 2S S6,H,*OEt /\OH C,H,*OEtIV. Reddish-brown anhydride. 111. Crimson hydroxide.The chloride (11) has been reduced to a diamine, which, on oxidation,gives rise to X-phenetyl-3 : 3'-diaminophenazothionium chloride (V).N/\//\AI I I I/ \ / \ / V N H 2 HN SCorresponding phenazothionium salts have been produced containinghydroxyphenyl i n the place of ~henetyl.6~Thiopyrine, the sulphur analogue of antipyrine, is regarded byMichaelis as having the formula (I). It has now for the first timebeen converted into l-phenyl-3-methyl-5-thiopyrazolone (IV) in themanner indicated in the following diagram :N*C,H, N*C,H,/\ /\Me# -S -2 (C&5'COC1) MeRC1 E.S*Co*C6H5MeC--CH --- +- MeC-CH(I.)$0 heleg;gN N C,H,/\G*S*CO*C,H,/\ 8 g*SH HydrolysisMeC -CH f-- MsC-CH(117.)6s S, Smiles and T.P. Hilditch, Trans., 1908, 93, 145, 1687ORGANIC CHEMISTRY. 167The presence of the thiol group SH is indicated by the mode inwhich the thiopyrazolone undergoes oxidation. Alkaline hydrogenperoxide gives rise t o the sulphonic acid, whilst nitrous acid or iodinein potassium iodide solution leads to the disulphide. Nevertheless,I-phenyl-3-methyl-5-thiopyrazolone also reacts in its thiocarboxyl form,and, like phenylmethylpyrazolone, it condenses with aldehydes andketones.64AZJcaloicls.Damascenine, the alkaloid from Xigella, has been investigated, andits constitution established.Boiling with alkalis converts it into anisomeride, damascenic acid, which by a series of steps yields %amino-3-hydroxybenzoic acid, proving it to be 2-methylamino-3 -methoxy-benzoic acid (I). The alkaloid, being devoid of acid properties,appears to be a betaine (11).C0,H co.0/\NHMe /\&H,Me I lOMe (,!OM.(11.1\/(1.1Methyldamascenine, present in the same plant, proves to be themethyl ester of damascenic acid. An attempt to synthesise thealkaloid, starting from methylanthranilic acid, failed owing to theimpossibility of introducing methoxyl 01’ hydroxyl in place of theamino-group in position 3, the diazonium compound changing into astable azimino-~ompound.~~Atropine may be synthesised by a method giving a much better yieldthan does the condensation of tropine with tropic acid, by acetylationof tropic acid, conversion into the chloride, condensation with tropinehydrochloride, and elimination of the acetyl group, the last processtaking place spontaneously when the acetyltropine is allowed t o remaina short time in aqueous solution.On the other hand, when an attemptis made to replace the chlorine in P-chlorohydratropyltropine byh ydroxyl, an intramolecular change takes place, hydrogen chloridebeing transferred, and ccpoatropine hydrochloride is obtained :CH2*CH-CH2 CH,C1 CH,--CH-CR, yH2 I &Me dH*O*CO*bHPh -+ 1 :>$Me C!lH*O*CO*C!PhCH2*CH--UH, UH,--CH--UH,This apoatropine synthesis is a general one for tropeines, startingfrom a-, p-, or y-halogenated propionic or m-butyric acids.66I I 1A.Micliaclis, AnmZcii, 1908, 361, 251 ; A . , i, 685.m 0. Keller, Arc7~. Phrtrnz., 1908, 246, 1 ; A . , i, 283.fi6 R. Wolffenstein and I,. Mamlock, Ber., 1908, 41, i 2 3 ; R. Wolffenstein and,J. Rolle, iEid., 733 ; A., i, 281, 282168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A contribution t o the study of cinchonine has been made in theform of an examination of cinchoninone, the ketone obtained byoxidation of the alkaloid. This ketone is amphoteric, and also exhibitsenol-keto-tautomerism, yielding both an oxime and a n 0-benzoylderivative. By the action of nitrous acid, cinchonic acid and an oximeare obtained, the latter yielding Koenig’s meroquinenine on hydrolysis.This leads t o formulse (I and 11) for cinchoninone and cinchoninerespectively : 67CH,* CH--CH C H : C H, CH,*CH-CH*CH:CIT,I II l l I II IUH--N-CH CH-N-CH,CO* C,NH, OH* CH C,NH,(1.) (11.1Although little progress has been made towards establishing theconstitution of the strychnos alkaloids, nevertheless crystalline acidshave now been obtained by oxidation, the composition of whichindicates that both alkaloids contain a secondary alcohol grouping66When papaverinium alkyl salts are treated with very dilute alkalis,the liberated papaverinium hydroxides undergo condensation to phenol-betaines.Thus N-methylpapaveriniurn methoaulphate yields thephenolbetaine,C,H2(0Me)*CH“Me-CHC,H,(OMe),=CH,*C/ >O )I .69I n the morphine group of alkaloids, a synthesis of a compoundobtained in the partial breaking down of morphine has been effectedfor the first time.Morpholquinone is known t o be 3 : 4-dihydroxy-phenanthraquinone, and this may be prepared from 3-nitrophenan thra-quinone by reduction, diazotisation, and conversion into the 3-hydroxy-compound, nitration in the 4-position, a repetition of the reduction anddiazotisation giving morpholq~inone.~~q-apocodeine is the 3-methyl ether of apomorphine, and thusstands in the same relation to apomorphine as codeine does t omorphine. 71Much work has also been carried out on the constitution of65 P. Rabe, BcT., 1908, 41, 62 ; A . , i, 100.LM H. Lenchs, ibid., 1711 ; A., i, 563.‘jg H. Decker and G.Dunnnt, Amalcn, 1908, 358, 288 ; A . , i, 204.7o ,J. Schmidt and J. Still, Bey., 1908, 41, 3696 ; A . , i, 995.7l L. Know and F. I:nxlw, ibid., 3050 ; .4., i, 908ORGA4NIC CHEMISTRY. 169sparteine T2 by means of a study of the reactions of a-methylsparteine.When degraded by Hof mann’s reaction, methylsparteine yields methyl-hemispar teilene,CH CHThe methylsparteines behave as unsaturated bases, having a methylgroup attached to nitrogen. The isosparteine into which they may beconverted is a ditertiary base, which does not reduce acid per-manganate. The conversion may be carried out by heating a-methyl-sparteine di-iodide with water at 1 2 5 O , when isomeric change toisosparteine methiodide takes place./CH(C,HJ,N)*CHCH.CH, /c (cSH14N)0CH2\ CH ~ - CH,*CH,-- ,NMe*OH -+ CH-\CH2--- CH,’ \CH,--- CH2-+ CH ~ CHM e/Na-i\lethylsparteinium a-Methylsparteine.hydroxide./CH( CsH,,N)*C‘H,\\CH2--- C*2isoSpar te i 11 e .The reverse change may be carried out by heating a-methyliso-sparteinium hydroxide in a vacuum, when it gives a-methylsparteine.The latter compound takes up two atoms of iodine to form themethiodide of an iodo-base, which behaves as if it were an iodoiso-sparteine,CH- /CJww14PJ)*C CH(CH,I)--H~=~;~Y~I,\CH2---- CH2but it is possible that its formation is due to the isomerisation ofthe a-methylsparteine under the influence of hydrogen iodide.Jateorrhizine and columbamine, alkaloids from columba root, havebeen further in~estigated,~3 and the monomethyl ether of columbamineis found to be identical with the dimetbyl ether of jateorrhizine.The acid obtained on oxidation of this ether is a trimethoxy-o-71 C.hlourco a i d A. Valenr, Compt. wnd., 1907, 145, 815, 929, 1184, 1343 ;1908, 146, 7 9 ; 147, 127 ; BdI. Soc. chim., 1903, [iv]: 3, 674 ; A . , i, 43, 44, 103,206, 563, 736, 1006.7s K. Feist, A 7 d ~ . Phnivn., 1907, 245, 586 ; d., i, 100170 ANNUAL REPORTS ON THE PROGKESS OF CHEMISTRY.phthalic acid, but it has not yet been determined whether themethoxyl groups have the 3 : 4 : 5- or 3 : 4 : 6-position. A thirdalkaloid, palmatine, closely resembling berberine, is also presentin the root, but its relation to the other two is unknown.Polypeptides.The progress in the building up of polypeptide niolecules has beenexceedingly rapid during the past year.Perhaps the most importantstep that has been made is that of introducing tyrosine groups intothe molecule. The tyrosine group is of such frequent occurrence innatural proteins that this advance was necessary before compoundsshowing the reactions of the true proteins could be prepared, especiallyas the difference between the naturally occurring and the syntheticpolypeptides is now recognised as consisting less i n the number ofamino-acid groups present than in the conjunction, in natural sub-stances, of groups of several different kinds.The usual method of synthesis is not applicable when an amino-hydroxy-acid, such as tyrosine, is employed, because of the actionof phosphorus pentachloride on the hydroxyl group.This may beprotected by the introduction of the carboinethoxyl group, whichresists the action of phosphorus pentachloride and*acyl chlorides, andis readily removed afterwards by hydrolysis. The protecting group isintroduced by means of methyl chlorocarbonate. The products are,however, inactive.74A tetrapeptide was isolated last year from silk, and was shown toconsist of two glycine groups and one group each of d-alanine andZ-tyrosine. Several attempts to synthesise this substance have beenmade, but in every case the product was found to differ from thenatural polypeptide in not being precipitated by ammonium sulphate,or in only being precipitated from very concentrated solutions. Suchcompounds, isomeric with the tetrapeptide sought after, have beenprepared by the action of Z-tyrosine ester on chloroacetyl-d-alanyl-glycine, and by coupling glycine-d-alanine anhydride with chloro-acetyltyrosyl chloride methyl carbonate, followed by hydrolysis.Theglycyltyrosylglycyl-d-alanine obtained in the second case is probably amixture of stereoisomerides.75 Various tyrosine polypeptides, derivedfrom glycine, d-alanine, and Z-leucine, were also not precipitatedby ammonium ~ u l p h a t e . ~ ~The 3 : 5-di-iodo-Ltyrosine group has also been introduced, onaccount of its occurrence in the proteins of coral. Glycyldi-iodotyro-i4 E. Fischer, Sitzuizgsber. K. Akad. Wiss. Berlin, 190s) 542 ; A., i, 544.75 E. Fischer, Ber., 1908, 41, 850, 2860 ; A , , i, 324, 887.76 E.hbderlialden and A. Hirszowski, ibid., 2840 ; A . , i, 8S7ORGANIC CHEMISTRY. 171sine has been ~ynthesised,7~ starting from the action of iodine ontyrosine.Various dipeptides have been prepared containing the d-valinegroup, which are of interest, not only in connexion with polypeptidesynthesis, but also for the stuiy of the Walden inversion.78 Morecomplex groups have also been introduced, notably the a-aminostearylgroup 79 and P-amino-acid residues, such as those of P-aminobutyricacid and a-methylisoserine.80It is found that glycine ethyl ester, like ethyl oxalste, may bereduced with sodium amalgam, the final product, after treatment withalcoholic hydrogen chloride, being aminoacetal.81 The appiication of asimilar method of reduction to polypeptides gives unsatisfactory yields,but the corresponding aminoacetals are readily prepared by the con-densation of aminoacetal with chloroacyl chlorides and treatment ofthe products with ammonia.The presence of histidine in many natural proteins, arid the exist-ence of proline (pyrrolidine-2-carboxylic acid) in the product,s of thehydrolysis of’ gelatin, have led Fischer and his pupils to include thesegroups also in the synthetic scheme, and methods of synthesis havetherefore been devised for the purpose of preparing the materials.82Z-Leucyl-Z-histidine is stable towards concentrated hydrochloric acid,and since both Z-leucine and Z-histidine are present in oxyhzemoglobia,the dipeptide was sought for, but unsuccessfully, in the products ofhydrolysis of that substance.The use of hydrofluoric acid has been recommended for the hydrolysisof proteins, as causing less secondary reactions than any other acidBs3Synthetical Thevapeutic Agents.Considerable activity is being shown in the production of localThis substance itself is the anaesthetics of the “novocaine” type.hydrochloride of diethylaminoethyl p-aminobenzoate,NH,*C,H4*C0,*C2H4*N( C2H5),,HC1.A series of similarly constituted compounds has been prepared, andtheir physiological action has been ascertained.Some of these sub-stances have pronounced local anaesthetic properties, but are not77 E. Abderhalden and hf. Guggenheim, Ber., 1908, 41, 1237 ; A . , i, 420.78 E. Fischer and H. Scheibler, Annalen, 1908, 363, 136 ; A., i, 957.79 E.Fischer and W. Iiropp, ibid., 362, 338 ; A., i, 773.s1 E. Fischer, Ber., 1508, 41, 1019 ; d., i, 323.82 E. Fischer and A. Iirkimer, ibid., 2728 ; E. Fischer and I,. H. Cone, Annalen,1908, 363, 107 ; E. Fischer and G. Reif, ihid., 118 ; A., i, 858, 1004, 1007.83 L. Hugounenq and A. Morel, Co?npt. rend., 1908, 146, 1291 ; A., i, 706.F. W. Kay, ibid., 348 ; A . , i, 773172 ANNUAL mpoms ON THE PROGRESS OF CHEMISTRY.suitable for use in medicine, owing either to their high general toxicityor to the local irritation produced by their i n j e ~ t i o n . ~ ~I n view of these results, it is open to doubt whether the many com-pounds recently described in patents are, in general, of much therapeuticvalue.The hydrochlorides of the clialkylaminoalkyl benzoates, such asC,H4-C02*CH2*CH2*NEt,,HCl, are stated to be useful anasthetics,*5whilst the alkylaminoalkyl aminocinnamates (for example,NH,*C,H,*CH: CH*CO;CH,* CH,*N Ett2)are said to surpass the alkylaminoalkyl benzoates in this respect.86It is claimed that the alkylaminoalkyl salicylates unite theseanasthetic properties with those of salicylic a ~ i d .~ 7Salicylic acid and its acetyl derivative (“ aspirin ”) have certainundesirable physiological properties, which are said to be favour ablymodified in the recently-described :anhydrides of acylsalicylic acids,Of these products, acetylsalicylic anhydride, O(CO*C6H,*O*CO*CH,),,and cinnamoylsalicylic anhydride, O(CO*C6H,*O*CO*CH:CH*C6H5)2,appear to be the most promising.88The recent commercially successful synthesis of the powerfulhaemostatic adrenaline by the Farbwerke vorm.Meister, Lucius, andBriining has stimulated research in this direction. An interestingseries of observations on the conversion of catechol methylene ethersinto cyclic carbonates by the action of thionyl chloride may be men-tioned at this stage.89The beazoylaminoacetylcatechol ethers,. C,H4*CO*NH*CH,*CO*C,H,(OR),,when hydrolysed with aqueous acids under pressure, yield arnino-OH()OHi/ CO*CH,*N H,acetylcatechol, which is stated to have powerful hamostatic propertieslike the active principles of the suprarenal capsules.g0The root of Canadian hemp (Apocynum cannmbinum) retards thebeart in systole. Apocynin, one of its physiologically active con-84 F.1,. Pyman, TI-am., 1908, 93, 1799.D.R.-P. 187209 ; A . , i, 167.8: D.R.-P. 188671 ; A., i, 176.h8 D,R.-P. 201325 and 201326 ; A . , i, 954.89 G. Earger and A .J. Ewins, ! L ’ r c ( ~ i ~ . , 1908, 93, 563, 735, 2081.yo D.E.-1’. 189483 ; A., i, 262,*‘j D.R.-P. 157593 ; A., i, 169ORGANIC CHEMISTRY. 173stituents, has been examined, and shown to be identical with aceto-vanillone. This conclusion has been confirmed by the synthesis ofapocynin from vanillin.g10 Bz()OM,CHO4BIg M e I \/ --+OH{)OM. -+\/C'HOVanillin.OBz 0132//)OM8 {)OM,CrOs \/ ++ \/VH*OH YoCH3 CH,Benzoylapocy nin. Benzoylapocynol.I I .i. OH+(HydrolysisOHf)OMe ()OM.\/ Yo \/ f-NafEtOHTH*OH.CHsApocynol.CH3Apocynin.5 : 5-Diethylbnrbituric acid (I' veronal") and its homologues stillreceive much attention, and new methods of preparation form thesubjects of many patents.Practically quantitative yields of theseacids may be obtained by treating with nitrous acid the dialkgl-malonylguanidines produced by condensing ethyl dialkylmalonateswith guanidine.92 A detailed study of the dialkylmalonic acids hasbrought to light the interesting fact that complex anhydrides of thesesubstances may be produced by treating the acid chlorides withaqueous pyridine. The duodecimolecular anhydride of diethylmalonicacid has in ethylene dibromide or benzene a complexity correspondingwith the formula [~$>C<~~>O],,. In nitrobenzene the degreeof association is diminished to that of an octamolecular anhydride.93Orgcmic Derivatives of Arsenic.The last few years have witnessed a great revival of interest in thestudy of organic derivatives of arsenic, owing to the circumstance thatcertain of these substances have proved efficacious in the therapeuticsof diseases of protozoic origin.Sodium p-aminophenylarsonate ('' atoxyl ") and its acetyl derivativehave been successfully employed in the treatment of trypanosomiasis(sleeping sickness).The former of these substances was discovered byq1 H. Finnemore, Trans., 1908, 93, 1513, 1520,B2 D.R.-P. 189076 ; A., i, 370.98 A. Einhorn, Annalen, 1908, 359, 145 ; A . , i, 312174 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.BBchamp in 1863, but its true nature was discovered only in 1907 byEhrlich and Bertheim.p-Aminophenylarsonic acid, NH,*C,H,*AsO(OH),, is the chiefproduct of the interaction of aniline and aniline arsenate a t 180°, butPyman and Reynolds have recently demonstrated that a small amount(2 or 3 per cent,) of bis-p-aminophenylarsinic acid (I) is simultaneouslypr0duced.~40These investigators have also prepared the corresponding bis-2-aminotolyl-5-arsinic acid, so that the reaction is probably a general one.These compounds are the aromatic analogues of cacod ylic acid,AsMe,O*OH.The camphor analogue, dicamphorylarsinic acid (11),has recently been isolated from the products of the action of arseniouschloride on sodium camph0r.~5The use of arsenious chloride for the introduction of arsenicinto aromatic compounds was first studied by Michaelis andhis collaborators.The dimethylaminophenylarsine oxide,NMe,*C,H4*As0,obtained from the chloride and dimethylaniline, has now been oxidisedt o dimethyl-p-aminophenylarsonic acid (dimethylatoxyl) by alkalinehydrogen peroxide.96Aminoarsonic acids can be obtained from all primary aromaticamines having an unsubstituted para-position, and by means of thediazo-reaction the corresponding hydroxy-arsonic acids have beenprepared.97Phenylarsonic acid gives a nitrophenylarsonic acid, which, onreduction, yields an aminophenylarsonic acid isomeric with the atoxylacid. The isomeride is probably a meta-derivative; unlike atoxyl, itretains its arsenic on boiling with hydriodic acid. I n the para-seriesthe arsenic is replaced by iodine.98The arsenic in these compounds is not removed by boiling withaqueous alkali hydroxides, but when fused with these reagents it iseliminated as alkali arsenate.The alkyl esters of arsenious acid, As(OEt),, etc., may be obtainedby heating arsenious oxide with the primary alcohols in the presenceB4 Trans., 1908, 93, 1180.y5 G.T. Morgan and F. M. G. Micklethwait, ibid., 2144,96 A. Michaelis, Ber., 1908, 41, 1514 ; A, i, 590.y7 L. Benda and R. Kahn, ibid., 1672, 3859 ; A., i, 591.g8 A. Bertheim, ibid., 1455 ; A., i, 590ORGANIC CHEMISTRY. 175of an insoluble dehydrating ngent (for example, dry copper sul-hate).^^When arseniousoxide is added to an ethereal solution of magnesiumphenyl bromide, it is found to undergo the Grignard reaction, with theproduction, after about thirty minutes, of diphenylarsine oxide,[ As(C6H,),],0.Prolonged treatment leads to the formation oftriphenylarsiue, As( C,H,),. The tri-p-tolylarsine, As(C,~;CH,),, issimilarly prepared, but in this case is unaccompanied by the 0xide.lMagnesium benzyl bromide gives rise to dibenzylarsine hydroxide,As(CH,*C6H,),*OH,H20.Silicolz Compounds.The chemistry of silicon derivatives offers many points forcomparison with that of carbon compounds of similar structure,remarkable similarities and equally striking diEerences of behaviourbeing observed. Thus the silicones, the silicon analogues of theketones, are not only compounds of considerable molecular com-plexity, tending to form molecules of the form (R2SiO), and boiling atvery high temperatures, but they are not reduced by the usualreagents for reducing ketones, and do not form oximes or phenyl-hydrazones.The latter circumstance may be due to the readinesswith which the Si-K linking is broken by water. Benzylethyl-silicone, 6 5 c H2>Si:0, is prepared with ease by the action ofwater on benzylethylsilicon dichloride. Two isomeric dibenzylsilicols,Si( CH2* C6H5)2(OH)2, were obtained, differing considerably in stability,but both yielding the silicone by loss of water. The nature of theisomerism remains unexplained, and other results which have beenobtained suggest that the isomerism of silicon-oxygen compoundsmay prove to be of a nature not hitherto encountered amongst carboncompounds.Stereoisomeric silicon compounds of such optical activity as to leaveno doubt as to the occurrence of optical antipodes in this series, havenow been prepared by sulphonating benzylet hylpropylsilicyl oxide andthe corresponding compound containing isobutyl in place of propyl,and crystallising the salts of the sulphonic acids with active methyl-hydrindamines. The sodium salts of the active isobutyl compoundshave a molecular rotation nearly twice as great as that of the propylcon~pounds.~C H *CH2 5SJ W.R. Lang, J. F. Mackey, and R. A. Gortner, Trans., 1908, 93, 1364.F. Sachs and H. Kantorowicz, Ber., 1908, 44, 1031 ; A,, i, 1031.R. Robisoii and F. S. Kipping, Trans., 1908, 93, 439.F. S. Kipping, ibid., 457 ; B.D. W. Luff and-F. S. Kipping, ibid., 2004, 2090176 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The utility of the Grignard reaction is very apparent in this work.I n the researches quoted above, for instance, benzylethylsilicondichloride, Si(C7H7)EtC12, was caused to react with magnesium iso-butyl bromide, giving benzylethylisobutylsilicyl chloride, which yieldsthe required silicol or oxide on treatment with water. The siliconicacids, the analogues of the carboxylic acids, may be prepared by theaction of magnesium alkyl or aryl haloids on silicon tetrachloride, anddecomposition of the resulting compound with water. Thus silico-butyric acid (propylsiliconic acid) is prepared by the followingreactions :PraMgBr + SiCI, = PraSiC1, + MgClBr.P&3iC1, + 2H20 = PFSi0,H + 3HC1.The trichlorides form ortho siliconic esters with alcoh01.~These esters may also be prepared by the action of magnesiumorganic haloids on ethyl orthosilicate, Si(OEt),, but it is only possibleto replace one ethoxyl group by this process. I n this way, variousaryl-substituted orthosiliconic esters, such as the xylyl and a-naphthylderivatives, have been prepared, yielding siliconic acids whendecomposed with water.5Silicochloroform reacts with aniline in benzene solution to formtrianilinosilicon hydride, SiH(NHPh),. This compound is useful as asource of silicoiodoform, which is obtained from it in good yield bythe action of hydrogen iodide in benzene solntion.GSulphur Compounds.The properties of the organic derivatives of sulphur present manypoints of interest, and it is not surprising that the number ofresearches dealing with these substances is on the increase. Theisomerism and tautomerism of many of them has an importantbearing on a department of chemistry which still remains veryobscure, namely, the structural arrangement of inorganic com-pounds.The action of alkalis on sodium alkyl thiosulphates has previouslybeen little investigated. The principal action appears to be theformation of the disulphide: 2R*S20,Na -+ R,S,. It is notnecessary, for the preparation of the disulphide, that the thiosulphateshould be isolated. Thus the product of the action of p-nitrobsnzylchloride on sodium thiosulphate, when treated with sodium carbonate,yields di-p-nitrobenzyl disulphide directly.7 The same is true ofW. Melzer, Ber., 1908, 41, 3390 ; A , , i, 967.E. Khotinsky and B. Seregenkoff, ibid., 2946 ; A,, i, 1032.0. Ruff, @id., 3738; A., i, 966.T. S. Price and D. F. Twiss, Tram., 1908, 93, 1395, 1401ORGANIC CHEMISTRY. 1 7 7alkyl compounds, and the substance obtained in solutioii byGutmann 8 from sodium ethyl thiosulphate, and supposed by him tobe EtSOH, is diethyl disulphide. Other disulphides may be betterprepared by the electrolytic oxidation of thiosulphates, dithio-diglycollic esters, for instance, being prepared in this way.gCertain disulphides, such as benzyl disulphide and 4 : 4'-dithio-acetanilide, are found t o occur in two isomeric modifications, oE whichone is converted into the other by the action of light.1° The natureof this isomerism remains unexplained.The oxidation of sulphides to sulphoxides is most satisfactorilyperformed by means of hydrogen peroxide, both for aromatic l1 and fattycompounds. Thus thionyldiglycollic acid, SO(C H,*CO,H),, is preparedin this way from thiodiglycollic acid.1,The constitution of thianthren (diphenylene disulphide) has beendefinitely proved to be that of an ortho-compound, by oxidation t o thedisulphone and treatment with phosphorus pentachloride, the productsbeing benzene-o-disulphonyl chloride and o-dichlorobenzene :Organic polysulphides, uplike their inorganic analogues, are notreadily prepared by the action of sulphur on alkyl mercaptides,oxidation taking place. They are obtained in certain cases by theaction of sulphur on disulphides in absolute alcoholic solution,saturated with anhydrous ammonia, but quantitative yields of tri-sulphides are obtained by the action of thionyl chloride on mercaptansaccording to the equation4R*SH + SOCI, = R,S, + R2S, + H20 + 2HC1.14The di- and tri-sulphides are separated by fractional distillation. Thetetrasulphide of acetic acid is obtaineJ by the action of sulphur chlorideon thiolacetic acid in ethereal solution.Sulphination, or the introduction of sulphinic groups into aromaticcompounds, is carried out by passing sulphur dioxide into a mixtureof the compound to be sulphinated with aluminium chloride. Thismethod has been described independently by two groups of workera.15The process is accelerated by passing in hydrogen chloride simul-A. Gutmanu, Bes.., 1908, 41, 1650 ; A., i, 497.T. S. Price and D. F. Twiss, Trans., 1908, 93, 1645.Ibid., 2836 ; A., i, 875.l o 0. Hinsberg, Ber., 1908, 41, 626 ; A., i, 25T.I p 11. Gazdar arid Y. Smiles, FrcCIw., 1908, 93, 1833.l3 J. J. B. Dews, Ber., 1908, 41, 2329 ; A . , i, 635.R. Holniberg, A m a h i , 1908, 359, 81 ; if., i, 308.l5 S. Smiles and R. Le Rossignol, Tra?~s., 1908, 93, 745 ; E. I<iioevcna,a~l mdJ . Kenner. RcT., 1908, 41, 3315 ; if., i, 970.REP.-VOL. V. 178 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.taneously with the sulphur dioxide, The work of Smiles and LeRossignol has led to the recognition of interesting steric influences inthis reaction. The sulphination will continue beyond the stage of thesulphinic acid to those of the sulphoxide and the sulphonium compound,the process being, in the case of phenetole :OEt*Ph -+ OEt*C6H4*SO2H -+( OEt*CGH4),S0 -+ (OEt*C6H4),S*OH.The group enters the same position as the sulphonic group insulphonation. How far the reaction will proceed is dependent ontwo factors, the directive influence of such groups as ethoxyl, andsteric hindrance by accumulation of ortho-substituents. Thus, withphenetole, the sulphinic group enters the para-position, and therebeing no ortho-substituents, the reaction proceeds t o the formationof the sulphonium compound. In the ethers of quinol, sulphinationtakes place in the ortho-position, and progress beyond the snlphinicacid stage is rendered difficult, and almost impossible, by accumulationof ortho-substituents.x X<7)SO,H -\ so/---/- \-X X X OH XTho relative influence of the two factors has been investigated inseveral cases.The constitution of the aromatic sulphinic acids has been furtherstudied by the examination of their oxidation products.16 Potassiumpermanganste, in glacial acetic acid, converts them into a-disulphones,which are identical with those obtained by the combination of sulphonylchlorides with sodium arylsulphinates. This indicates that the acidsreact as R*SV102*H, and not as R*SIVO*OH. The U-disulphones, suchas C,H,*SO,*SO,*C,H,, are stable, rather inert substances, onlydecomposed by hot concentrated alkalis.Aldehydes and ketones react with alkaline sodium hyposulphite,forming compounds which appear to be esters of sulphoxylic acid,RRCO + Na2S204 + NaOH = REC(OH)-SO,Na + Na,S0,.17The sodium formaldehydesulphoxylate, known commercially asrongalite, probably has one of the two following structures :CH2<g>SNa*OH or 0H.C H,* O*SO,Na.16 T. P. Hilditch, Trans., 1908, 93, 1524.l7 E. Fronun, Ber., 1908, 41, 3397 ; A . , i, 968ORGANIC CHEMISTRY. 179It forms a dibenzyl derivative,CH,<g>S\C711,) 0. C,H, or C7H70*C H, O*SO,-C,H,,with benzyl chloride.Sodium thiosulphate and formaldehyde react to form thioform-aldehyde, which assumes the termolecular form, ( CH,S),.lSA few organic selenium and tellurium compounds have beenprepared. A similar method to that employed for the preparationof sulphonium compounds leads t o the formation of selenoaiumderivatives, namely, the condensation of phenolic ethers with seleniumdioxide in presence of aluminium chloride. The selenonium basesare very stable, their salts are hardly acted on by sodium hydroxide,but yield hydroxides with silver 0xide.1~Di-a-naphthyl selenide and telluride, ( CloH,),Se and ( Cl,H7),Te,and similar compounds have been prepared by the action of seleniumor tellurium on mercury dinaphthyl and its analogues.20Many of the researches not recorded in this Report, although ofgreat importance, are omitted because they represent intermediatestages in the att'ack on one of the outstanding problems of this branchof chemistry. At this point it is often impossible to correlate andexplain concisely the different lines along which the attack is beingdirected. But when success has been. attained, it will then be foundthat these investigations will fall naturally into their places in therecords of future reporters as necessary steps in tho execution ofanother noteworthy achievement of organic analysis or synthesis.CECIL H. DESCH.GILBERT T. MORGAN.L. Vanino, J. pr. Chin., 1908, [ii], 77, 367 ; A . , i, 318,l9 T. P. Hilditch and S. Smiles, Tmns., 1908, 93, 1384.2o R. E. Lyons and G. C. Bush, J. Amer. Chrn. Soc., 1908, 30, 831 ; A., i, 417

ISSN:0365-6217    

DOI:10.1039/AR9080500073

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.IN presenting this Report of the year’s work in analyticalchemistry, the writer wishes to emphasise the fact that, from thenature of the subject, it is scarcely possible to fulfil the objectof the ‘I Reports ” as set forth in the “ Introduction ” to Vol. I.(1904). I n the first place, the text must necessarily be somewhatdisjointed, since, in the particular branch of chemistry underreview, it is much more difficult than in others to construct aconnected narrative, for prominence can seldom be given to anyparticular researches which tend to advance our knowledge of thesubject as a whole. The broad reasons for this are not far toseek. Although there are some notable exceptions, it cannot bedenied that the number of papers found in journals devoted toanalysis in which new chemical principles are brought forward isbut few, the greater part of the literary matter which has to beperused in writing a review on analytical chemistry dealing withwhat, may a t best be described as improvements rather thanoriginal discoveries.Moreover, among this majority are to be foundsome communications which are not only valueless but actuallymisleading. For these reasons, therefore, as well as from the factthat this report makes no attempt a t being exhaustive, it is obviousthat some selection must be made, and-apart from his ownexperience-the writer has based his selection on the internalevidence contained in each paper. I n so voluminous and widelydisseminated a literature, it is possible, indeed probable, thatseveral deserving contributions to the subject may not havereceived notice, either from inadvertence or errors in judgment,but it is hoped that these omissions may amount to a minimum,and that a judicious selection has been made.I n connexion with research in analytical chemistry, it may bementioned that an important step has been taken by the (( Societyof Public Analysts and Other Analytical Chemists ” in inauguratinga scheme for the investigation of analytical processes and ofproblems in analytical chemistry, and also for the revision of pub-lished methods and their extended study when desirable.UndeANALYTICAL CHEMISTRY. 181this scheme it is suggested that the investigations might be under-taken by some of the senior students working in the larger collegesand teaching institutions, and a fund has been established by theabove Society for defraying incumbent expenses.The only con-ditions are that accounts of the researches are to be published(subject to the approval of the Editorial Committee) in TheAnalyst, and, when possible, to be brought before the Society inthe form of communications.1Inorganic Ch emist ly.Qualitative.-The system of qualitative analysis, the first twopapers on which were published last year by A. A. Noyes andW. C. Bray: has been further developed by A. A. Noyes, W. C.Bray, and E. B. Spear.3 This third communication deals with themetals of the ammonium sulphide group. It is impossible toreview such a paper as a whole, covering as it does someeighty pages, but among other things the authors show thatwhen the precipitate obtained with ammonia and ammoniumsulphide is dissolved in acid, and the solution boiled with a mixtureof sodium peroxide, hydroxide, and carbonate, the members of theiron group, including nickel, cobalt,, thallium, manganese, titanium,and zirconium, are precipitated, whilst those of the aluminiumgroup, including glucinuni, zinc chromium, uranium, and vanadium,remain in solution as sodium salts.A somewhat similar scheme,involving the use of hydrogen peroxide and sodium hydroxide, issuggest.ed by E. Ebler.4 H. Caron and D. Raquet 5 suggest sodiumperoxide as a reagent for the separation of the elements of group 111in presence of phosphates.The same compound is recommended byD. F. Calhane for the detection of chromium in presence of iron;the oxidation proceeds to the perchromate stage. For the rapidqualitative analysis of a mineral, W. B. Pollard’s 7 process consistsin fusing it with vaselin and sodium peroxide. The more posi-tive elements remain in the melt as insoluble oxides and carbonates,whilst the others exist in the highest state of oxidation as solublesodium salts; special tests must be made for mercury (on account ofits volatility) and for sodium. J. H. Walton, jun., and H. A.Scholz8 describe a method for decomposing certain slags andAnal@, 1908, 33, 41.Bid., 1908, 30, 481 ; A., ii, 538.Zeitsch. anal. Chen?., 1908, 4’7, 665 ; A . , ii, 987.BUZZ. SOC. chinz., 1908, [iv], 3, 622 ; A ., ii, 630.J. Amer. Chem SOL, 1908, 30, 770 ; A., ii, 630.Chem. News, 1908, 98, 211 ; A . , ii, 1069.Amer. Chem. J., 1908, 39, 771 ; A., ii, 732.’ J. Aster. Chem. SOC., 1907, 29, 137 : A . , 1907, ii, 391182 ANNUAL REPOKTS ON THE PBOGRESS OF CHEMISTRY.sulphide ores, which consists in fusing them with a mixture ofsodium peroxide, zinc sulphide, and potassium persulphate.In order to detect helium in minerals, F. BordasQ heats thesubstance, and passes the gas through a Dewar’s charcoal tube;the helium is much less readily absorbed @an other gases, and maybe detected spectroscopically.E. Selvaticilo advocates the use of thioacetic acid instead ofhydrogen sulphide for the precipitation of the metals of group 11.He also gives a scheme of separation obviating the use of ammoniumsulphide.H. Bollenbach 11 makes use of ammonium persulphatein separating the metals of group 11. G. D. Lander and H. W.Winter12 deal with the detection of poisonous metals.L. Tschugaeff 13 has pointed out that Pozzi-Escot’s molybdatemethod of detecting nickel 14 is less sensitive than his own dimethyl-glyoxime method.15 Pozzi-Escot 16 has modified his molybdatemethod, and more recently 17 he has described conditions wherebycobalt may be detected in the presence of 1000 times its amountof nickel. H. Grossmann and B. Schuck18 state that this methodhad been previously described by Marckwald; they also state thatas a test for nickel in the presence of cobalt it is less delicate thantheir O W ~ , ~ Q besides which there is a tendency for the precipitationof cobalt as the violet molybdate.20 H.Grossmann and W.Heilborn 21 suggest the use of dicyanodiamidine for the simultaneousdetection of nickel and cobalt. The former metal gives a crystal-line precipitate,22 and the latter an intense reddish-violet colora-tion.23W. Neumann 24 describes an electrolytic method whereby 0.008milligram of zinc in 0.1 C.C. of solution may be detected. L. W.McKay 25 draws attention to the danger of zinc sulphide re-dissolvingwhen precipitated in presence of sodium hydroxide.Compt. rend., 1908, 146, 628 ; A., ii, 430.lo Boll. chirn. farm., 1908, 47, 73 ; A., ii, 322.l1 Zeitsch. anal. Chew., 1908, 47, 690 ; A., ii, 984.l2 Analyst, 19d8, 33, 450 ; A ., 1909, ii, 95.l 3 Compt. rend., 1907, 145, 697 ; A., 1907, ii, 989.l5 B e y . , 1905, 38, 2520 ; A., 1905, ii, 613 ; Kraut, Zeitsch. angew. Chem., 1906,l6 Ann. Chim. anal., 1908, 13, 16 ; A., ii, 133.l7 Ibid,, 390 ; A . , ii, 988.l9 Bcr., 1906, 39, 3356 ; A., 1906, ii, 908.2o See, fnrther, Chem. Zeit., 1908, 32, 804 ; BUZZ. SOC. chin?., 1908, [ivl, 3, 894 ;21 Ber., 1908, 41, 1878 ; A., ii, 635. Ann. Report, 1907, 205.23 See also H. Grossmann, Chin. Zeit., 2908, 32, 315 ; A . , ii, 434.24 Zeitsch. Elcktrochcm., 1907, 13, 751 : A., ii, 67.Ann. &port, 1907, 200.19, 793 ; A., 1906, ii, 858 ; Brunck, Ann. Report, 1907, 205.Bull. SOC. chim., 1908, [iv], 3, 14 ; A., ii, 230.A . , ii, 899.J. Amer. Chem. Soc., 1908, 30, 376 ; A., ii, 431ANALYTICAL CHEMISTRY.183W. Bette126 states that molybdic acid gives, with hydrogenperoxide and a trace of ammonia, a brownish-red coloration. Amethod for the detection of ruthenium in platinum alloys bas beendevised by N. A. O r l ~ f f . ~ ~N. Schoor128 describes the appearance under the microscope ofsilver, lead, and mercurous chlorides, and later 20 that of arsenic,antimony, and tin compounds. Subsequently30 he deals with themicrochemical analysis of the sulphides of mercury, bismuth, lead,copper, and cadmium. In connexion with the well-known volatilityof mercury compounds, K. Kof and H. Haehn31 state that amoistened filter-paper placed over a 2 per cent. solution of mer-curic chloride for sixty-five hours is rendered black on treatmentwith hydrogen sulphide; also that a distinct white patch is obtainedon developing a photographic plate which has been kept for twenty-four hours a t a distance of 2 to 3 mm.from a drop of it 0.01 per cent.solution of mercuric chloride.32 J. Moir33 gives two methods forthe detection of mercuric chloride in nitrocellulose.According to M. DelBpine,34 one part of copper in 1,000,000 canbe detected by the brown coloration produced with a solution ofa dialkyldithiocarbamate. Iron gives a pink colour with thisreagent; nickel and cobalt also give colours. E. Enechts5 showsthat when titanous sulphate is added to a solution of a copper salt(limit one part of copper per 1 ,OOO,OOO), metallic copper separates.A. W. Gregory36 states that 0.01 milligram of silver may bedetected by the brown colour produced on addition of ammoniumsalicylate and persulphate.W. J. Earslake’s method for the detec-tion of manganese and chromium in mixtures37 consists in boilingthe solution in nitric or sulphuric acid with ammonium persulphateand silver nitrate, when permanganate and perchromate are formed.When shaken with hydrogen peroxide and ether, the former isdecomposed, whilst the latter dissolves in the ether with the pro-duction of the well-known blue colour.H. Caron and D. Raqueta point out that in the well-knownmethod of detecting barium in presence of strontium and calcium,*6 Chem. News, 1908, 97, 40; A . , ii, 230.27 Chernz. Zeit., 1908, 32, 77 ; A . , ii, 231.?8 Zeikch. anal. Cltem., 1908, 47, 209 ; A , , ii, 432.29 Bid., 367 ; A., ii, 777.30 Bid., 729 ; A , , 1909, ii, 96.31 Arch.Pharnt., 1907, 245, 529 ; A., ii, 69.32 Compare Zeitsch. physikal. Chem., 1907, 60, 367 ; A., 1907, ii, 732.33 Chem. News, 1908, 97, 133.34 Bull. SOC. chim., 1908, [iv], 3, 652 ; A., ii, 633.37 J. Amor. Cl~cnz. Soe., 1908, 30, 905 ; A . , ii, 635.38 Bidl. SOC. chim., 1908, [iv], 3, 453 ; A . , ii, 496.Rer., 1908, 41, 498 ; A . , ii, 270. 36 Proc., 1908, 24, 125184 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the addition of hydrofluosilicic acid sometimes leads to the deposi-tion of gelatinous silica, which may be mistaken for bariumsilicofluoride. They show 39 that barium may be eliminated fromstrontium salts by fractional precipitation by alkali chromates.J. Milbauer40 states that neodymium gives a colourless boraxbead in the oxidising, and a violet in the reducing, flame, whilstpraseodymium gives a yellowish-green bead in the oxidising, anda green in the reducing, flame. 0.Lutz41 points out that boraxbeads are to be preferred for the detection of positive, and phosphatebaads for negative, ions. J. Donau 42 describes a delicate methodof detecting gold, platinum, and silver by means of the meta-phosphate bead.For the detection of phosphates in minerals, A. P. Lidoff 43heats the finely-powdered mineral first alone, and then with mag-nesium or a mixture of it and aluminium; the fusion is gentlywarmed with 20 per cent. sodium hydroxide solution, the evolvedgases being brought in contact with copper sulphate paper.Theformation of copper phosphide (black coloration) indicates thepresence of phosphorus. J. S. Jamieson4' describes a test forbromides.Quantitative.-An important contribution to the theory ofindicators is that of J. T. Hewitt,45 who points out the insufficiencyof the ionic theory alone in explaining the colour changes ofphenolphthalein, and concludes that the assumption of tautomericchange must also be made. In the light of A. G. Green's experi-m e n t ~ , ~ ~ Hewitt assumes that this and like indicators obey thefollowing equilibrium in solution :O:X,*H Z X,*O*H Z X,*O'+H',where Xu and X, are isomeric radicles. These considerations Zedhim to recommend p-nitrobenzeneazo-a-naphthol as an indicator.It yields results similar to phenolphthalein when used for the titra-tion of alkali hydroxides with weak acids, the colour change beingfrom purple 150 yellow.The view that phenolphthalein exhibitstautomerism was put forward by S. F. Acree in 1904, but wasdenied by J. Stieglitz. Acree's latest hypothesis 47 commends itself,however, t o Stieglitz.48 A. Hantzsch and F. Hilscher49 bring39 Bull. Soc. chim., 1908, [iv], 3, 493 ; A . , ii, 496.4u Zcitsch. anal. Chem., 1907, 46, 657 ; A . , ii, 70.41 It&?., 1908, 47, 1 ; A., ii, 226.42 ZeiLwh. Chem. Ind. Kolloide, 1908, 2, 273 ; A . , ii, 434.43 J. .Buss. Pl~y.?. Chem. Soc., 1908, 40, 817 ; A., ii, 894.44 Proc., 1908, 24, 144.46 Ber., 1907, 40, 3724 ; J. Soc. Chem. Ind., 1908, 27, 4 ; A . , 1907, i, 933.J5 Amer.Chew. J., 1908, 39, 528, 649 ; A . , i, 422, 653.49 Ber., 1908, 41, 1187; A., i, 469.45 A?LaZ~jst, 1908, 33, 85 ; A . , i, 269.Bid., 651 ; A . , i, 652 ; compare Ibid., 789 ; A . , i, 653ANALYTICAL CHEMISTRY. 185forward evidence that helianthin, in the solid state, has a quinonoidstructure, but that in aqueous solution it exists as an aminoazo- andsulphonic acid-form in equilibrium, whilst its sodium salt (methyl-orange) is a sulphonate both in the solid state and in solution.J. H, Hildebrand50 has applied the Konig spectrophotometer tothe measurement of the dissociation c o d a n t of phenolphthaleindissolved in aqueous solutions of ammonia and ammonium chloride,in which the concentration of the hydrogen ions is known.It isfound to be 1*7x10-10 for solutions in which 5 to 65 per cent. ofthe phenolphthalein is dissociated.51 M. Barberio 52 has describe?a new indicator, “ resorubin,” obtained by the action of nitrous acidon resorciiiol ; the violet neutral solution becomes blue with alkalisor yellow with acids. It is said to resemble lacrnoid, but to bemore sensitive in presence of ammonium salts. E. Rupp and R.Loose 53 propose pdimethylaminoazobenzene-o-carboxylic acid as anindicator which may be used for the titration of weak bases suchas alkaloids; it can be used to titrate ammonia even in N/100-solution. To distinguish mineral from organic acids, E. Linder 54employs metanil-yellow paper, which (with the former only) becomesviolet. A. B. Lyons 65 recommends haematoxylin for titrating phos-phoric acid.J. K. Wood 56 has carefully determined the basic andacidic constants of arsenious and aluminium hydroxide. V. H.Veley’s paper on the affinity constants of bases, as determined bythe aid of rnethyl-~range,~’ is of interest to analytical chemists.S. P. L. Sorensen and A. C. Andersen58 give some useful hintson Winkler’s method of estimating hydroxides in presence of car-bonates.69 L. Clarke and C. L. Jackson60 show that rosocyanin,the substance which is produced in the test for boric acid withturmeric paper, is an isomeride of curcumin, Cl4HI4O2.I n connexion with halogen derivatives, P. Jannasch 61 has con-tinued his studies on the separation of the halogens by means ofhydrogen peroxide.62 I n its present form, his method is quantita-tive, good results being obtained for chlorine and iodine, whilst thosefor bromine are slightly low.H. Baubigny 63 has modified Hager’s50 Zeitsch 3lektrochem., 1908, 14, 349 ; A., ii, 646.51 Compare R. Wegscheider and A. Schugowitsch, Jblbid., 510 ; A , , ii, 806.52 Gaxzetta, 1907, 37, ii, 577 ; A., i, 161.53 Ber., 1908, 41, 3905 ; A., 1909, ii, 90.54 J, Soc. Chem. Ind., 1908, 27, 485 ; A , , ii, 627.55 Phnrm. Bev., 1908, 26, 9 7 ; A., ii, 532.56: Trans., 1908, 93, 411.57 Ibid., 652.59 Compare also Anclersen, Tihkr. Kem. Farm. Terapi, 1908, 11, 161 ; A., ii,( j l J. pi’. Chcm., 1908, [ii], 78, 28 ; A . , ii, 730.54 Zeitsch. anaZ. C?mn., 1908, 47, 279 ; A., ii, 534.Amer. Chem. J., 1908, 39, 696 ; A ., i, 670. 985.Ann. RepoTt, 1906, 203. 63 Compt. rend. 1908, 146, 335 ; A., ii, 321186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.method of separating silver halides.s4 When only the chloride andiodide are present, these may be separated quantitatively by treat;ment a t 70--80° with a solution containing 10 grams of ammoniumsesquicarbonate and 20 C.C. of 20 per cent. ammonia per litre; thisdissolves the silver iodide only. B. H. Buttle and J. T. Hewitto5have studied the solubility of silver chloride in mercuric nitratesolution, and arrive a t the same conclusion as Morse>@ that whenmercuric nitrate is present in large excess, chlorine only occurs asHgCl ions. For the determination of fluorine in rocks, etc., inquantities up to 3 per cent., G.Steiger67 makes use of the factthat fluorides bleach the coloration produced by hydrogen peroxideand titanium. As this is not a linear function, reference is madeto a curve. The presence of aluminium salts and phosphatesinfluence the results, which, however, are in no case trustworthywhen as much as 10 per cent. of fluorine is present. B. Carlsonand J. Gelhaar 68 deal with the detection and estimation ofchlorites and hypochlorites in chlorates. E. Knecht 69 has deviseda, volumetric method for the estimation of chlorates. D. Venditori 70makes the interesting observation that, in presence of sulphuricacid, chlorates but not perchlorates are reduced by finely-dividedaluminium. Griitzner’s method of determining chlorates andbromates by heating with formaldehyde, nitric acid, and silvernitrate71 has been extended to iodates and periodates by H.Brunner and R.Mellet.72 To prevent loss of free halogen, and toobviate working in a closed vessel, potassium persulphate is addedto the reaction mixture. H. Baubigny 73 shows that an ammoniacalsolution of silver chloride or bromide, when heated with iodicacid, only deposits silver iodide when a temperature of 200° isreached.Use has been made of sodium peroxide by S. W. Parr74 in theestimation of sulphur in pyrites, coal, and indiarubber. Pyritesis mixed with sodium peroxide, potassium chlorate, and benzoicacid, and the mixture ignited in a special bomb; the melt containsthe sulphur as sulphate. A special mixture appears to be required64 Zeitsch.anal. Chcm., 1871, 10, 341.65 Trans., 1908, 93, 1405.66 Zeitsch. physikal. Chem., 1902, 41, 709 ; A., 1903, ii, 12.67 J. Amer. Chem. Soc., 1908, 30, 219 ; A., ii, 426.68 Chem. Zcit., 1908, 32, 604, 633 ; A., ii, 731.69 J. SOC. Ghem. Ind., 1908, 27, 434 ; A., ii, 627.7O Gazzetta, 1907, 37, ii, 383 ; A., ii, 63.7 l Arch. Phamn., 1896, 234, 634 ; A . , 1897,ii) 166.p2 J. pr. Chem., 1908, [ii], 77, 33 ; A., ii, 222.TJ Compt. rend., 1908, 146, 1097 ; A., ii, 577.74 J. Aiiier. Chem. Soc., 1908, 30, 764 ; A., ii, 628ANALYTICAL CHEMISTRY. 187for each substance. Carbon in carborundum may be estimated(as carbonate) by heating the sample in this way with sodiumperoxide and “ boro-magnesium ” mixture.75 The results quotedare satisfactory (see also under Organic Chemistry).E. Jaboulay 76describes a volumetric method for estimating sulphur in steel. Fora detailed study of the various methods for this purpose, M. Orthey’spaper77 may be consulted. According to H. Kiliani,78 when alkalithiosulphate is titrated in alkaline solution with permanganate, as inReinige’s method of estimating iodides,79 sulphate and not tetra-thionate is formed, hence 8 mols. of permanganate require 3 mols.of thiosulphate for decomposition. V. LenhersO shows that in themethod of estimating tellurium by precipitation with hydrazineF1it is an advantage if the solution contains sulphurous acid; theresults are accurate.As usual, a great many papers have appeared during the yeardealing with the estimation of phosphorus and phosphates.F. W.Hinrichsen 82 has confirmed the accuracy of H. Lidholm’s process 83for the estimation of phosphorus in calcium carbide. An accuratemethod for the estimation of phosphorus in phosphor-tin has beendevised by W. Gemmell and S. L. Archbutt.84. F. Repiton85describes a modification of Malot’s method of estimating phosphoricacid by titration with uranic solution, employing cochineal, in sit@,as indicator; the results are shown to be satisfactory. For theestimation of phosphorus in iron, etc., G. Chesneau 86 weighs theammonium phosphomolybdate precipitate, and states conditionswhereby this compound may be precipitated in presence ofammonium nitrate containing constantly 1.6 per cent. of phos-phorus.With reference to the estimation of phosphoric acid asammonium phosphomlybdate,87 G. von Knorre,88 adverting to hisprevious statement that tungstic acid may be separated from phos-phoric acid almost quantitatively by precipitation with benzidinehydrochloride, points out that the results are vitiated by the insolu-75 LOG. cit.77 Zeitsch. angcw. Chem., 1908, 21, 1359, 1393 ; A . , ii, 731.78 Chem. Zeit., 1908, 32, 1018 ; A., ii, 982i9 Zeitsch. anal. Chem., 1870, 9, 39.go J. Amer. Chem. Soc., 1908, 30, 388 ; A., ii, 426.a1 Gutbier, Ber., 1901, 34, 2724 ; A., 1901, ii, 687.a2 M<tt. K. illaterialpriifs-Amt. Gross. Lichterfelde West, 1907, 25, 110 ; A .BS Zeitsch. angew. Chesn., 1904, 17, 1452 ; A., 1904, ii, 776.84 J. Xoc. Chem. lnd., 1908, 27, 427 ; -4.) ii, 629.85 Mon.Sci., 1907, [iv], 21, ii, 753, 815 ; A . , ii, 320, 428.bG Compt. rend., 1908, 146, 758 ; A . , ii, 427.s7 Compare P. Christensen, Zeitsch. nnnl. Chent., 1908, 47, 529 ; A., ii, 895 ;76 Rev. gen. chim. pure appl., 1907, 10, 193 ; A., ii, 223.1908, ii, 131.E. Rabcn, ibid., 546 ; A., ii, 896. Ibid., 37 ; A., ii, 231188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.bility of benzidine phosphate in water, but he shows that theseparation is quantitative when the homologous tolidine hydro-chloride is employed.In connexion with the estimation of carbon in iron and steel,M. Orthey89 shows that the combustion method in a current ofoxygen in presence of bismuth oxide gives good results. L. L. deKoninck and E.von Winiwarterm propose to burn the substancewith lead borate in a current of oxygen. H. Isham and J. Aumer 31show that when iron or steel is ignited in a current of oxygen alone,the carbon (but not the sulphur) is almost completely burnt.C. M. Johnson 92 describes an electric furnace for the estimation ofcarbon in iron, etc. New apparatus for the moist method have beendevised by M. Widemann93 and by T. Grzeschik.94 E. P. Mooreand 5. W. Baing5 show that during the solution of steel in potass-ium cupric chloride there may be a loss of 0-4-0.5 milligram ofcarbon per gram of steel. I n titrating lead with sodium sulphide,H. Koch 96 adds carbon tetrachloride to cause the subsidence of theprecipitate. Some useful data on the colorimetric estimation of leadas sulphide are given by H. W.Woudstra.97 Several papers dealingwith the assay of red lead have been published during the year.gsThe last-mentioned shows the limit of accuracy of the various methodsin use. Some useful volumetric methods of estimating mercury aredescribed by E. Rupp,99 and by the same author in conjunction withW. 3'. Schirmer.1 For the estimation of mercuric salts, S. G.Liversedge suggests conversion into mercuric iodide and extractionof the latter with ether; the method is particularly adapted for theestimation of small quantities of mercury. In connexion with theestimation of mercury, the volatility of its salts (see p. 183) is, as arule, ignored by authors. J. F. Spencer and Miss M. Le Pla havedevised a very accurate method of estimating silver and thalliumyQ Chefit.Zcit., 1908, 32, 31 ; A , ii, 131.go Rd1. SOC. chim. Bclg., 1908, 22, 104 ; A . , ii, 320.g1 J. Anier. CJzenz. Soc., 1908, 30, 1236 ; A . , ii, 898.93 Ibid., 773 ; A . , ii, 630.g3 Zeitseh. chem. Apparatenkunde, 1908, 3, 296 ; A., ii, 954.g4 Chem. Zcit., 1908, 32, 1092; A., ii, 1071.g5 J. SOC. Chem. Id., 1908, 27, 845 ; A., ii, 899.9s Chem. Zeit., 1908, 32, 124 ; A . , ii, 227.97 Zeitsch. anorg. Chem., 1908, 58, 168 ; A . , ii, 633.98 See for instance J. F. Sacher, Chem. Zeit., 1908, 32, 62 ; A., ii, 228 ;E. Pieszczek, Pharm. Zeit., 1908, 53, 87 ; A., ii, 228 ; E. E. Dunlap, J. Amer.Chem. Xoc., 1908, 30, 611 ; A . , ii, 537; P. Beck, Zeitsch. anal. Chcm., 1908, 47,465 ; A . , ii, 777.Chem.Zeit., 1908, 32, 1077 ; A., ii, 1073.Pharm. Zeit., 1908, 53, 928 ; A . , ii, 1073.Analyst, 1908, 33, 217 ; A . , ii, 634. ;i 2'raiu., 1908, 93, 858ANALYTICAL CHEMISTRY. 189in mixtures. W. R. Lang and J. 0. Woodhouse4 describe a’modification of Lang and Allen’s apparatus which may be employedfor the estimation of silver by Gay-Lussac’s method.G. S. Jamieson, H. L. Levy, and H. L. Wells6 propose a volu-metric method for the estimation of copper, which, on their evidence,has an average limit of accuracy of one in 300. The copper isprecipitated as cuprous thiocyanate, and the latter, after washing,dissolved in dilute hydrochloric acid and titrated with potassiumiodate and chloroform. The writer can fully confirm H. Theodor’sstatements 7 regarding the accuracy of Volhard’s titration methodof estimating copper; more than twenty years ago he used themethod of neutralising the solution with a slight excess of ammoniabefore reducing with sulphurous acid for the purpose of gettingrid of the nitric acid, which is now suggested by 0.Kuhn.8 A. K.Huntington and C. H. Deschg deal with the planimetric analysisof alloys and the structure of phosphor-copper.The fact that when titrated with permanganate in presence ofhydrochloric acid ferrous salts require more of the standard solutionthan is necessary for their oxidation to the ferric state has longbeen known. T. W. Harrison and F. M. Perkin lo find that additionof manganous sulphate retards the reducing action of hydrochloricacid, but that the colour interferes with the end point of thetitration. In discussing their paper, 0.Heher11 quoted Fre-senius’s directions, and cited a paper by Loewenthal and Lenssen.12In a lengthy paper by L. Brandt,l3 the necessity is urged ofstandardising the permanganate in presence of hydrochloric acidwhen that acid occurs in the assay liquid. Directions are givenfor the preparation of ferric oxide in a state of purity, which isrecommended as the best compound to use in standardising thesolution; the reduction is effected by stannous chloride. In otherpapers on the permanganate method, M. 31. P. Muir14 proposest o arrest the evolution of hydrogen, when the reduction of ferricsalt is accomplished with zinc, by the addition of mercuric chloride;and H.D. Newton15 employs titanous sulphate as reducing agent,destroying the excess with bismuth oxide. The results quoted areTrans., 1908, 93, 1037.J. Amer. Chem. Soc., 1908, 30, 760 ; A . , ii, 634.Chem. Zeit., 1908, 32, 889 ; A . , ii, 898.Trans. Faraday SOC., 1908, 4, 51 ; A., ii, 846.Ibid., 1907, 91, 1370.* Ibid., 1056 ; A . , ii, 1072.lo Analyst, 1908, 33, 43 ; A., ii, 228. 11 Ilk?.l2 Zeitsch. anal. Chem., 1861, 1, 329, 361.l 3 Chem. Zeit., 1908, 32, 812 ; A., ii, 899.Chem. News, 1908, 97, 57 ; A., ii, 228.lr, Amcr. J. Sci., 1908, [iv], 25, 343 ; A., ii, 538190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.very accurate. G. Edgar16 deals with the estimation of iron andvanadium in mixtures by titration with permanganate, and inanother paper 17 he has elaborated conditions whereby vanadic andmolybdic oxides may be estimated by permanganate.S. B. Jatar'smethod 18 for the estimation of iron and chromium by titration withtitanous chloride appears useful and accurate. H. Bollenbach l9proposed to titrate ferric salts with sodium hyposulphite (Na2S02).For the decomposition of ferro-compounds, especially ferro-silicon,P. Nicolardot2O heats with sulphur chloride. R. B. Moore andI. Miller21 show that iron may be precipitated from it solutioncontaining free hydrochloric acid by means of pyridine ; aluminium,chromium, and zinc are partly precipitated, whereas manganese,nickel, and cobalt remain in solution. F. C. Mathers22 shows thattraces of iron may be removed from indium by precipitation froman acetic acid solution by nitroso-&naphthol.According to A.W. GregoryF3 one part of iron in 10,000 ofcopper may be detected by the red colour given by ferric salts withsalicylic acid in presence of sodium acetate. He bases a colori-metric method on this reaction.With reference to the dimethylglyoxime and dicyanodiamidinemethods of estimating nicke1,24 0. Brunck 25 brings forward evidenceshowing the superior accuracy of the former, whilst Grossmann andSchiick 20 uphold the dicyanodiamidine method on the ground thatthe nickel compound is insoluble in strong ammoniacal alkalihydroxide solutions. H. Cantoni and M. Rosenstein 27 propose forthe volumetric estimation of nickel, titration with either ferro- orferri-cyanide, using ferric (or uranium) or ferrous icdicators' respec-tively; the ferricyanide method with the liquid faintly acidifiedwith acetic acid gives the better results.In a series of papers M.E. Pozzi-Escot deals with the estimationof both nickel and cobalt by the molybdate method and the separa-tion of these metals from others.2sl6 Zeitsch. anorg. Chem., 1908, 59, 74.l 7 Anzer. J. Sci., 1908, [iv], 25, 232 ; A., ii, 540.J. Xoc. Chem. Ind., 1908, 27, 673 ; A., ii, 778.l9 Chem. Zeit., 1908, 32, 146 ; A . , ii, 229.20 Compt. rcnd., 1908, 147, 676 ; A., ii, 1074.21 J. Amcr. Chem. SOC., 1908, 30, 593 ; A., ii, 434.22 Ibid., 209 ; A., ii, 434.23 Trans., 1908, 93, 93.25 Zeitsch. angew. Chem., 1907, 20, 1845 ; A., 1907, ii, 989.26 lbid., 1981 ; A., ii, 71.28 Ann.Chim. anal., 1908, 13, 66 ; Compt. rend., 1907, 145, 1334 ; A., ii, 229 ;Ann. C h h . n?:ccl., 1908, 13, 89 ; A., ii, 324 ; ibid., 85, 215, 217 ; A,, ii, 539,640, 635.24 Ann. Report, 1907, 205.Bull. Soc. chirn., 1908, [iv], 1, 1163 ; A., ii, 230ANALYTICAL CHEMISTRY. 191E. D. Campbell and W. Arthur29 describe a modification ofMoore’s volumetric method 30 for the estimation of nickel andchromium in steel. A. A. Blair 31 has worked out a scheme for thedetermination of vanadium, molybdenum, chromium, and nickel insteel; from the single example given, it appears to be very accurate.The estimation of vanadium in iron and steel is dealt with by E. D.Campbell and E. L. W0odhams.3~In connexion with the estimation of tin, D.B. DottB drawsattention to the solubility of metastannic acid in hydrochloricacid; he points out further that, in the analysis of ores, tin isvolatilised when a solution in aqua regia is evaporated to drynessfor the purpose of separating the silica.34 H. Reynolds35 titratesa stannous solution with dichromate, using azobenzenesulphonic acidas indicator; the restoration of the red colour of the indicatormarks the end of the oxidation. E. Schurmann and W. Scharfen-berg36 describe a modification of Clarke’s oxalic acid method forthe analysis of white metal. A. eKolb and R. Formhals37 showthat the reaction Sb,O, + 4HI f Sb,O, + 2H,O + 21, is practicallycomplete from left t o right if aufficient excess of hydriodic acid beused.L.Rosenthaler’s observations 38 respecting the quantitative pre-cipitation of arsenious and arsenic acids, the former by bariumchloride and ammonia and the latter by barium chloride andsodium hydroxide, are worthy of attention. H. Reckleben and G.Lockemaun 39 describe gravimetric, volumetric, and gasometricmethods of estimating arsine in air.P. Cazeneuve40 utters a warning against the use of arseniferousdressings as insecticides in agriculture. The Gutzeit test for arsenic,antimony, and phosphorus has been rendered more conclusive byB. Sjollema.41 I n the case of arsenic, he states that he was ableto obtain microscopical crystals with 0.005 milligram of arseniousoxide. C. H. Nieuwland,& on the other hand, was unable to2~ J. Amer.Chem. SOC., 1908, 30, 1116 ; A , , ii, 779.3O Chcm. News, 1895, 72, 92 ; A., 1895, ii, 534.31 J. Amcr. Chew. SOC., 1908, 30, 1229 ; A., ii, 900.3 3 Ibid., 1233 ; A , , ii, 901.33 PJzawn. J., 1908, [iv], 27, 486 ; A . , ii, 899.See further, Ibid., 585 ; A . , ii, 1075.35 Chem. News, 1908, 97, 13 ; A., ii, 134.36 Mitt. K. ~nterialprufgs.-Amt., 1908, 25, 270 ; A . , ii, 537.37 Zeitsch. anorg. Chem., 1908, 58, 189 ; A., ii, 599.a* Apoth. Zeit., 1907, 22, 982 ; A., ii, 322.39 Zeitsch. anal. Chem., 1908, 47, 126 ; A . , ii, 224.*O Rev. intern. Palsq., 1908, 21, 11.41 Chenz. WeekblacE., 1908, 5, 11 ; A . , ii, 431.42 Ibid., 558 ; A . , ii, 896192 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.detect less than 0.05 milligram of arsenious oxide in this way.43W.van Ryn44 points out that sodium fluoride may prevent com-pletely the formation of arsenical mirrors in the Marsh-Berzeliusmethod, although it has no influence on the Gutzeit or Fluckigerreaction. E. Salkowski 45 deals with the detection and estimation ofarsenic in urine. To detect arsenic in sulphur, J. Brand 46 extractsthe finely-powdered sulphur with ammonia.M. Orthey47 has made it careful study of certain volumetricmethods of estimating manganese in ferro-manganese ores, and heshows that the Volhard-WolE method 48 and those of von Knorre 49and Blair give results agreeing well with those yielded by theordinary gravimetric method ; the first two are specially recom-mended.51 For the detection and colorimetric estimation of man-ganese, M.Duyk52 makes use of the red coloration produced whena trace of manganese is heated with an alkaline solution ofhypochlorite in presence of a trace of copper sulphate. H. W.Rowel1 53 estimates small quantities of bismuth colorimetrically asiodide.Miss Z. Kahan54 has devised a method for the quantitativeseparation of barium and strontium. 0. Hauser, in conjunctionwith F. Wirth, has published some important data on the solu-bility of the oxalates of the rare earths in dilute sulphuric andoxalic acids.55 Later 56 he shows that the precipitation of theseoxalates is incomplete in presence of uranyl salts. M. Dittrich67describes the separation of cerium from other metals and itsestimation.To separate lithium from other alkali metals, L.Eahlenberg andF. C. Krauskopfbs take advantage of the solubility of lithiumchloride in pyridine. The precipitation of potassium as cobalti-45 For microchemical reactions of arsenic, see also G. Denigks, Contpt. Tend.,1908, 147, 596, 744 ; 8., ii, 1070.l4 Phnrm. Weekblnd., 1908, 46, 98 ; A . , ii, 224.4.i Zeitsch. physiol. Chem., 1908, 56, 95 ; A., ii, 734.46 Zeilsch. ges. Brauwesen, 1908, 31, 33 ; A., ii, 532.47 Zeitsch. anal. CJzem., 1908, 47, 547 ; A., ii, 898.48 Ihid., 1880, 20, 271 ; compare Volhard, A , , 1880, 141.49 Ibbid., 1904, 43, 643 ; compare A., 1902, ii, 108.Ibid., 1904, 43, 647 ; compare A., 1904, ii, 683.51 Compare E. W. Meyer, Zeitsch. angew. Cheni., 1907, 20, 1980; A., ii, 71 ;52 Ann. Chim. anal., 1907, 12, 465 ; A., ii, 70.63 J.Soc. Chem. Ind., 1908, 27, 102 ; A., ii, 325.64 Analyst, 1908, 33, 12 ; A, ii, 133.55 Zeilsch. anal. Chem., 1908, 47, 389 ; A., ii, 778.56 Ibid., 677 ; A., ii, 987..57 Ber., 1908, 41, 4373.58 J. Amcr. Chem. Xoc., 19OS, 30, 1104 ; A., ii, 777.L. Sacerdoti, L’lndustria Chimica, 1907, 7, 258 ; A., ii, 228ANALY'I'ICAL CHEMIS'I'HY. 193nitrites9 is dealt with by W. A. Drushe1,GO and by W. Auteiirieth,61who shows that the precipitate obtained with de Koninck's cobaltreagent is not of constant composition.For the estimation of tungsten and its separation from othersubstances, advantage may be taken of the fact that it is volatilisedas oxychlorides when heated strongly in a mixture of chlorine andsulphur chloride,62 or when heated at 500° in a current of aircharged with chlorine.63 Tungsten trioxide is reduced by hydrogenat 600-900°, and may be then volatilised by treatment withchlorine.64 G.von Knorre has applied his benzidine method@ tothe estimation of tungsten in steel containing chromium.GG F. W.Hinrichsen and L. WolterG7 state that the results are low. Theydescribe other methods of estimating both tungsten and chromium.Methods for the estimation of vanadium in presence or absence ofiron are described by T. Warynski and B. Mdivani,G8 and byG. Edgar.69Electrochemical A naZysis.-The work conducted in this depart-ment during the year indicates steady progress, and shows theincreasing utility of electrolytic methods. F. Foerster 70 summarisesour knowledge of rapid electrolytic methods, especially those inwhich rotating electrodes are employed.His claim of priority forrotating electrodes has been disputed by A. Classen,71 and a seriesof polemical papers by these authors have followed.72 F. M.Perkin 73 remarks that rotating electrodes were first described byGooch and Medway, E. Smith, and himself almost simultaneously.F. A. Gooch and F. B. Beyer 74 employ as cathode a Gooch cruciblewith asbestos filter in the case of precipitates which do not adherefirmly.The reduction of alkali nitrate to ammonia in presence of copperwas studied by Easton in 1904, and subsequently by Ingham in1905. 0. L. Shinn75 states that in order to realise Ingham's5g Adie and Wood, Trans., 1900, 77, 1076.G1 Centr.Min., 1908, 513 ; d., ii, 897.tj2 F. Bourion, C'onzpt. T C ~ Z ~ . , 1908, 146, 1102 ; - 4 . , ii, 737.63 P. Nicolardot, i b i d , , 147, 795; A . , ii, 1074.64 E. Defacqz, ibid., 146, 1319 ; d., ii, 737.G Ann. h'epwt, 1905, 192.Zdsch. nital. Chenz., 1908, 47, 337 ; A . , ii, 779.67 Zeitsch. nnorg. Chem., 1908, 59, 183 ; A., ii, 900.Ann. Chint. anal., 1908, 13, 209, 210 ; A., ii, 636, 736.69 Amer. J. Sci., 1908, [iv], 26, 79 ; A . , ii, 736.7O Zeitsch. Eleklroehent., 1908, 14, 3.i2 Ibid., 141; 208, 239; A . , ii, 432, 529.76 Amer. J. ,Ski., 1908, 25, 249 ; d., ii, 529.75 J. Amm. Chem. SOC., 1908, 30, 1378 ; A . , ii, 893.Zeitsch. cmorg. Chein., 1907, 56, 223 ; 1898, 59, 97 : A., ii, 66, 735.71 Ibid., 90.73 Ibid., 143; A , , ii, 432.REP.-VOL.V. 194 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.results, the anode must be rotated slowly; the current should be4-5 amperes a t 10 volts, and not more than 20-25 C.C. ofN/5-sulphuric acid should be present. He also finds that it issometimes necessary to add a second or even a third quantity ofcopper sulphate in order to complete the reduction.H. W. Gillett 7G describes the conditions necessary for the deposi-tion of silver in presence of copper from ammoniacal tartratesolutions ; an important point is that when the electrolysis is carriedout at a temperature below 20° very rapid rotation of the anode isnecessary. Miss M. E. Holmes77 deals with the separation ofcadmium from a large number of metals. 0. Scheen78 gives somedetails for the electrolytic estimation of antimony.I n conjunctionwith his paper should be read that of E. C0hen.7~ H. 5. S. Sandhas continued his useful studies on the rapid separation of metals,POand in a second communication81 it is shown that by means of theapparatus previously described with rotating anodes, coherentdeposits of antimony may be obtained from solutions in sulphuricacid (1 : 1) in the presence of hydrazine sulphate; the temperaturemust be kept above looo with a cathode potential measured againstan auxiliary 2N-sulphuric acid of 0.65 volt. Tin is not depositedunless the auxiliary potential rises above 0.8 volt. I n order toeffect its deposition after separating the antimony, oxalic acid isadded, the solution neutralised with ammonia, and again acidifiedwith sulphuric acid.Considering the difficulty of this separationon theoretical grounds, the results are extremely good. For theseparation of copper from iron, an apparatus is described, includinga parchment paper diaphragm. The influence of temperature onthe estimation of copper is discussed by 5. R. \Vithrow,B2 whilstE. E. Free 53 deals with the estimation of small quantities ofcopper. A. Thiels4 shows that nickel can be estimated accuratelyby the electrolysis of the nitrate provided no nitrite be present,sufficient excess of animonia be added, and a straight wire ofpassive iron used as anode (platinum anodes are attacked); hegives conditions for the separation of nickel and copper quantita-tively. F. Foerster and W.Treadwell 55 confirm Thiel and Windel-76 J. Physical Chem., 1908, 12, 26 ; A . , ii, 226.77 J. Amer. Chem. Xoc., 1908, 30, 1865.78 Zeitseh. Elektrochein., 1908, 14, 257 ; A., 5, 636.Ilbid., 301 ; A . , ii, 636.f o A m . ZZeport, 1907, 207.s1 T r a 7 ~ ~ . , 1908, 93, 1672.g2 J. Amer. CJwa. Soc., 1908, 30, 381 ; A., ii, 432.a; J. Physical Chcm., 1908, 12, 25 ; A . , ii, 227. -s4 Zciitsch. Elektt*ochena., 1908, Id, 201 ; A., ii, 535.S9 Ibid., 89 ; A., ii, 321ANALYTICAL CHEMISTRY. 195schmidt’s statement,*$‘ that in separating nickel from zinc by elec-trolysing an ammoniacal solution containing sodium sulphite aselectrolyte, the deposited nickel contains sulphur. As pointed outby A. Fischer, h0wever,~7 without sodium sulphite a much highercurrent density is required.He gives conditions for the estimationof the two metals. It would appear advisable, taking into accountthe observations of the various authors, to dissolve the nickel firstdeposited and again electrolyse. In the electrolytic estimation ofnickel, A. Schumann shows 88 that a gauze cathode is preferable to adisk or cone cathode. R. Goldschmidt,89 in the electrolysis of zincsilicofluoride, uses a stationary slanting anode, over which thesolution passes and is returned by a pump. F. J. Metzger andH. T. Beans’ method of estimating bismuth by electrolysing anacetic acid solution seems to be very accurate on the evidencegiven.go J. PesettY91 after electrolysing a bismuth salt, adds a knownweight of cadmium sulphate, and continues the electrolysis.Thedeposited cadmium is said to protect the bismuth from oxidationand to render it more adherent.G. Gallo and G. Cenni92 state that by electrolysing a solutionof thallium sulphate, faintly acidified with oxalic acid, at theordinary temperature in a Classen’s capsule with a rotatingplatinum cathode, the whole of the thallium is deposited a t theanode apparently as a new oxide, T1,0,.J. S. Goldbaum and E. P. Smith 93 have continued their experi-ments on the separation of the alkali metals95 to the chloridesof ammonium, caesium, rubidium, and lithium with satisfactoryresults ; attempts to separate potassium and ammonium wereunsuccessful.General.-Sir W. Crookes95 points out the utility of iridiumcrucibles in analysis, chiefly on account of the high resistance ofthe metal against the attack of reagents; but he states that rhodiumpossesses almost the same resistance, and its cost would be lessbecause of its lower density.It is interesting to note that fusedsilica apparatus, which is adapted for so many purposes in analysis,has recently been considerably cheapened.8fi878s899Q9192939195Zeitsch. aizgew. Cl~em., 1907, 20, 1137 ; compare A., 1907, ii, 601.Chem Zeit., 1908, 32, 185 ; A., ii, 324.Zeitsch. ungezu. Chem., 190e, 21, 2570 ; A . , 1909, ii, 97.Bull. SOC. chim. Bely., 1908, 22, 138 ; A., ii, 536.J. Amer. Chem. Soc., 1908, 30, 589 ; A , , ii, 541.Zeitsch. anal. Chem., 1908, 47, 401 ; A . , ii, 780.Atti R. Acad.Lincei, 1908, [v], 17, ii, 276 ; A . , ii, 986.J. Amer. Chein. SOC., 1908, 30, 1705 ; A . , ii, 1072.Ibid., 1907, 29, 447, 1445, 1455; A., 1907, ii, 574, 988.PTOC. Xoy. SOC., 1908, 80, A., 535 ; A . , ii, 702.0 196 ANNUAL REPORTS ON THE PROGRESS OF CHERIISTRY.A modification of the Ostwald pipette for calibrating burettesand other measuring vessels has been devised by *O. von Spindler.96Other useful apparatus in connexion with volunietric analysis isdescribed by G. Muller97 and G. Miiller and 0. Berchem.98A. Gawalowski 99 has devised an apparatus for mixing liquidsduring a reaction. A simple manometer for use when distill-ing under diminished pressure is described by N. L. Gebhard,land H. Siicht,ing 2 has devised an automatic stirring arrangementwhich can be applied to liquids liable to bump when being distilledunder diminished pressure.P. A. Kober 3 describes an apparatuswhereby Folin’s method may be applied to Kjeldahl nitrogendeterminations; and, later,4 he deals with the estimation of carb-amide by Folin’s method. A new form of pyknometer for veryaccurate work has been devised by W. R. Bousfield.5Gas A naZysis.-Useful methods for the detection of ozone,hydrogen peroxide, and nitrogen peroxide in air are describedby E. H. Keiser and L. McMaster.6 P. Mknihre7 gives a methodfor the estimation of mercury vapour in air, whilst J. Ogier andE. Kohn-Abrest 8 deal with the detection and estimation of smallquantities of carbon monoxide in air. C. A. Keane and H.Burrows 9 show that the autolysator for the automatic determina-tion of carbon dioxide in furnace gases gives accurate results.A.Fraenckel 10 deals with the estimation of phosphorus, sulphur,and silica in acetylene. W. A. Bone and R. V. Wheeler l1 describean apparatus for the analysis of mixtures of hydrocarbon gases,and A. E. Hill12 describes a new gas burette. A. Stock13 dcaIswith the uses of the mercury trough in the manipulation of gasesand their treatment with reagents. He gives some useful hints onthe re-purification of mercury. New gas analysis apparatus hasw SchweQ. W o c h . Chenz. Piiurm., 1908, 46, 145 ; A., ii, 625.97 Chem. Zeit., 1908, a, 5 3 2 ; A,, ii, 626.98 Ibid., 711 ; A., ii, 775.9y Zcitsch. m~nb. Ckem , 1908, 47, 697 ; A . , ii, 939.YP’oc., 1908, 24, 51.Zcitsch.C I I L C C ~ . Chem., 1908, 47, 755 ; A,, 1909, ii, 35.[bid., 1279 ; A., ii, 893.Trans., 1908, 93, 679.Anier. Chem. J., 1908, 39, 96 ; A . , ii, 222.Ann. Cicinz. anal., 1908, 13, 169, 218 ; A . , ii, 631, 632.J. Xoc. Chem I ~ t d . , 1908, 27, 608 ; A., ii, 735.J. Soc. Chcm. Iwd., 1908, 27, 10 ; A . , ii, 221.,?3ei*., 1903, 41, 3834 ; A., 1909, ii, 89.:3 J. Amer. ChenL. S‘OC., 1908, 30, 1131 ; A., ii, 626.7 C’onhpt. reud., 1908, 146, 754 ; A., ii, 433.lo J. Gnsbelezcclrt., 1908, 51, 431 ; A . , ii, 983.l2 Tram., 1908, 93, 1857AXALYTICAL CHEMISTKY. 197been devised by R. Ross and J. P. Leather.14 H. Franzenls hasdevised a simple apparatus by meam of which a gas may beabsorbed from a mixture containing a large proportion of non-absorbable gas.L. M. Dennis and E. S. McCarthy16 recommendan ammoniacal solution of nickel cyanide as an absorbent forbenzene in illuminating gas.lVater AnaZysis.-F. Telle 17 proposes a solution containing0.344 gram of gypsum per litre as a sta'ndard in the Clark process.The method suggested by C. J. Blacher and J. Jacoby,? of estimat-ing alkaline earths by titration with potassium stearate and phenol-phthalein, is worthy of attention. H. Nolll9 gives a method for theestimation of carbonic acid and carbonates in chalybeate waters. E.Ernyei 2o describes a method of estimating manganese in waters.A useful paper on the systematic investigation of potable watersis that by G. Romyn,21 who discusses the flora and fauna of potablewaters.22 J.E. Purvis and R. M. Courtauld23 show that organicnitrogen compounds are attacked to a certain extent by the copper-zinc couple, so that the estimation of nitrates and nitrites by thismethod in presence of organic nitrogen compounds gives too highresults. A simple apparatus for observing the rate of absorptionof oxygen by polluted waters has been devised by W. E. Adeney.Z4I<. Saito25 points out that Bacillus coli comrnunis is so widely dis-seminated that great caution must be exercised in condemning awater as polluted because of its presence.G. 0. Adams and A. W. Kimbal126 show that, in the estimationof nitrogen in sewa,ge by the Kjeldahl method, the ammoniaformed may be nesslerised. H. W. Clark and G. 0. Adams 27 statethat the odour and appearance of incubated effluents give a betteridea of their putrescibility than does the measurement of the timerequired to decolorise dyes.I4 J.SOC. C I m i . I?irZ., 1908. 27, 491 ; A., ii, 626.l5 Zeitsch. n n o ~ g . Chcni., 19OS, 57, 395 ; il., ii, 425.lo ,J. Antcr. Chma. SOC., 1908, 30, 2YS ; il., ii, 435.l 7 J. Plmrm. Chilli., 1908, [vi], 27, 380 ; A . , ii, 63%.'8 C ' l ~ ? r i . Zeit., 1908, 32, 744 ; A . , ii, 807.'Jo Chcm. Zcit., 1908, 32, 41 ; A., ii, 133.F2 C'hein. Weekblnd. Reilnyc, 1908, 3015 ; P h n ~ m l17ccX:blrrtl, 1905, 45, 1287.s Yroe. Camb. Phil. SOC., 1903, 14, 441 ; A., ii, 776.24 Sc7:. PTOC. IZoy. Dub/. ,j'or., 1903, 11, 280 : A . , ii, 781.25 Amh. Byqienr, 19OS, 63, 215.O6 J. A?)LcY.CILcm. ,Yor. 1908, 30, 1033.Zcitsch. nngezo. Chc?n., 1908, 21, 840, 1455 ; (l. T,iiiigt>, ibid., 633 ; A , , ii, 4%.Phnrin. lvcekblad, 1908, 45, 402.2; IOfd., 1037198 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Organic Chemistry.Qualitative.-This portion of the literature is as voluminous asusual, but it will only be necessary to mention a few papers.L. E. Hide128 deals with the detection of methyl alcohol in ethylalcohol. I. Lifschutz29 states that the green colour produced bywarming an acetic acid solution of cholesterol with benzoyl peroxide,although less sensitive than Liebermann’s reaction, has advantagesin the position of the absorption bands. Some colour reactionsof cholesterol and oxycholesterol are described by L. Golodetz,30 and,by the same author,31 a colour reaction with formaldehyde andbenzoyl peroxide.I n connexion with Hehner’s test for formalde-hyde in milk,32 H. D. Dakin33 characterises a number of aliphaticketones and aldehydes by the appearances and melting points oftheir p-nitrophenylhydrazones. H. J. H. Fenton and G. Barr34tabulate the colour reactions produced by formic, oxalic, dihydroxy-tartaric, pyruvic, aa-dimethylglutaric, lactic, saccharic, laevulic, andoxalacetic acids when treated with resorcinol, phenol, pyrogallol,or o-cresol in presence of concentrated sulphuric acid. Accordingto W. M. Dehn and S. F. Scott,35 sodium hypobromite givescharacteristic colours with phenols and aromatic amines. T. Silber-mann and N. Ozorovitz36 make use of the formation of resinouscondensation products (insoluble in ordinary solvents) from formal-dehyde and dihydric phenols to detect and identify the latter.F.A. Steensma’s observation^,^^ that an aromatic or heterocyclicaldehyde in presence of a mineral acid gives a colour with phenolsor with heterocyclic compounds containing the group C:CH, aremost interesting as showing that certain colour reactions canactually be predicted, a generalisation of which he cites specificinstances. The formation of an additive (red) compound withp-dimethylaminobenzaldehyde is recommended by B. von Pawlew-ski38 as a characteristic reaction of anthranilic acid. Some newdifferential reactions of the naphthols are described by Volcy-Boucher.39 C. Lefebvre 40 describes some biochemical reactions2* Analyst, 19OS, 33, 417 ; A ., ii, 1056.3O Chcm Xeit., 1908, 32, 160 ; A . , ii, 328.31 See F. von Fillinger,, Zeitsclz. Ifah?-. Genusmz., 1908, 16, 226 ; 8., ii, 902.3* J. Biol. Chem., 1908, 4, 235 ; A . , , ii, 234.Proc. Canzb. Phil. Soc., 1908, 14, 386 ; A . , ii, 438.3B J. Arne?.. C h m . SOC., 1908, 30, 1418 ; A , , i, 780.36 R i b t . SOC. SC~. B?Leuresei, 1908, 17, 41 ; A., 1909, ii, 9s.:(7 Biochenz. Zeitsclt., 1909, 8, 203 ; A,, ii, 442.3* Ber., 190S; 41, 2353 ; A., i, 638.m Am. C‘/iint. a?inE., 19OS, 13, 335 ; A., ii, 990.4o Arch. Phawi~., 1907, 245, 493 ; A!., ii, 57.2D Ber., 1908, 41: 252; A., ii, 233.31 Jbid., 245 ; A . , ii, 330ANALYTlCAL CHEMISTRY. 199(enzymic) for the detection of sugars and glucosides in the Taxacex,B.Tollens and F. Rorive 41 describe colour and spectral reactions ofsugars and their derivatives on treatment with naphtharesorcinol.B. Tollens42 uses the same reagent for the detection of glycuronicacid in ~ r i n e . ~ 3 E. C. Kendall and H. C. Sherman 44 recommendpbromobenzylhydrazide as a reagent for the detection and identifi-cation of various sugars; the hydrazone obtained from galactose isinsoluble in boiling alcohol, whilst those of mannose and lzvuloseare sparingly, and that of dextrose readily, soluble. It is well knownthat even the hexoses give traces of furfuraldehyde when boiledwith acids. C. Fleig 45 shows that furfuraldehyde gives colorationswith indole and with carbazole. L. Garnier 46 deals with somecolour reactions of digitalis glucosides.In connexion with alkaloids, C.Reichard 47 describes somereactions of tropacocaine, which serve to differentiate it fromcocaine. G. Denig&s48 gives some reactions of hordenine, andL. Krauss 49 some reactions of synthetic suprarenine.F. Schulz50 calls attention to the red coloration given when asolution of (crude, not pure) picric acid in benzene is added to amineral oil, a reaction which serves for the detection of the latter inanimal and vegetable oils. Tests for oleic acid are described byA. Manea 51 and I. Lifschutz.52&ziuntitutiva.-There are a few papers dealing with elementaryanalysis demanding notice. M. Dennstedt 53 details the precautionsto be taken in his simplified method of determining carbon indifficultly combustible substance^.^^ He describes 6j a new form ofsoda-lime absorption apparatus, and A.E. Hill56 a new form ofpotash bulbs. W. Lenz57 points out that the percentage of carbon41 Ber., 1908, 41, 1783 ; A . , ii, 638.43 See also K. Tollens, Zeitsch. physiol. Chmz., 1908, 56, 115 ; A . , ii, 740 ; andcompare 6. A. Mandel and C. Neuberg, Biochcm. Zeitsch., 1908, 13, 148 ; A., ii,993.Ibid., 1788 ; A., ii, 639.44 J. Amer. Chem. Soc., 1908, 30, 145 ; A., ii, 902.45 J. Pharm. Chinz., 1908, [iv], 28, 385 ; A . , ii, 1077.46 Ibid., 27, 369 ; A., ii, 544.47 Plinrm. Zentr.-h., 1908, 49, 337 ; A . , ii, 643.48 Bull. Unoc. chim., 1908, [iv], 3, 786 ; A., i, 735.4g Apoth. Zeit., 1908, 23, 701.51 Bulb.Soc. Sci., Bucuresci, 1908, 17, 256.Ii3 Bcr., 1908, 41, 60 ; A . , ii, 321.54 Compare J. ZtLleski, BdI. 24cad. Sci. Crrccou-., 1907, ii, 646 ; .4., ii, 132.65 CIwn. .%it., 1908, 32, 77 ; A., ii, 225.57 Zeitsch. anal. Chcni., 1907, 46, 557 ; A . , ii, 65.50 Chew. Zeit., 1908, 32, 345.Zcitsch. p12ysiol. Chenl., 1908, 56, 446 ; A . , i, 754.Proc., 1908, 24, 182200 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.obtained by the Carrasco-Plancher method58 is apt to be low onaccount of the formation of carbon monoxide. 0. Carrasco andE. Bellonisg recommend a modification of the method, in whichthe organic substance is mixed with powdered platinised biscuitporcelain as catalyst instead of cupric oxide. M. Dennstedt andF. Hassler 60 describe a method and apparatus for the simultaneousestimation of carbon, hydrogen, halogen, and nitrogen, and fromthe one example given-analysis of pyridine platinochloride-theresults would appear to be accurate enough for purposes of check.61For the estimation of the halogens and sulphur, W.Parr showsthat his method of heating with sodium peroxide and “boro-magnesium ” mixture (see p. 186) may be used. To estimate sulphurin indiarubber, he burns the sample with sodium peroxide, potass-ium chlorate, and benzoic acid.62 According to H. D. Richmond,63the higher results obtained when the nitrogen in casein is estimatedby Dumas’s method, as compared with Kjeldahl’s method, is dueto the presence of unburnt carbon monoxide in the former case.He also describes a simple method of estimating nitrogen in com-pounds containing the triazo-group.A series of papers have beenpublished by P. Blackman 64 on a new method of estimating vapourdensity.J. Herzog and V. H. H h c u 65 show that the number of hydroxylgroups present in a phenol may be determined by condensing itwith diphenylcarbamyl chloride, hydrolysing the resulting urethane,and weighing the diphenylamine formed. A. Kirpa166 points outthat methoxyl determinations in such a substance aseither by the Zeisel or by the Herzig-Meyer method are invariablylow, probably due to the wandering of the methyl group from theoxygen to the nitrogen at0rn.~7G. T. Morgan and T. CookG8 describe a useful distillation flaskadapted for use in many methods for the analysis of organic sub-5R Ai~ii.l k p o ~ t , 1906, 21 1.(io Bdr., 1908, 41, a778 ; A . , ii, 984.61 Coml~tre J . %ellenter, Prograiiim cl. Obcrrcnlschulc, Jii,7isbrucX*, 1908 ; Chcn).w2 See p. 186.64 Bcr., 1908, 41, 768, 881, 1558, 2487, 4141 ; c o i n p t ~ i ~ Pro(:., 1908, 24, S :65 Ber., 1908, 41, 638 ; A . , ii, 327. 66 Ibitl., 819 ; A., ii, 436.(;; Compare J. Werzig, Monntch., 1908, 29: 295 ; A., ii, 638.GJ Analyst, 1908, 33, 118 ; A . , ii, 424.J. Pha~in.. Ch,itii., 1008, [vi], 27, 469 ; A., ii, 631.Zmtr., 1908, ii, 635.Annlyst, 1908, 33, 179 ; A . , ii, 530.A., ii: 157, 564 ; A , , 1909, ii, 21ANALYTICAL CHEMISTRY. 201stances in which distillation is necessary. R. Corradi 69 recom-mends the gasometric (hypobromite) method of determining theammonia formed in the Kjelda,hl method.V. von Cordier70describes a modification of Hiifner's hypobromite method for theestimation of nitrogen, and a special apparatus for carrying it out.H. Bollenbach 71 has modified de Haen's volumetric process ofestimating f errocyanides, and the evidence he brings forward showsthat the results are trustworthy. A valuable paper on the analysisof commercial ferrocyanides is that by H. G. C0lman.7~ The paperdeals with the direct estimation of the ferrocyanide by titrationwith copper or zinc sulphate, the estimation of the iron and thecalculation of the ferrocyanide from the results, and the estimationof the hydrogen cyanide. G. Heikel 73 has published a useful paperon the limits of accuracy of the Messinger and Denig'es' methodsof estimating acetone.V. F. Herr 74 describes a new dephlegmatorfor the fractionation of naphtha. I. Bay75 shows that carbondisulphide may be estimated in benzene by precipitating withphenylhydrazine, and weighing the resulting phenylhydrazinephenylthiocarbazate, CS,(Ph-NH=NH,),, dried in a vacuum desicca-tor. This process is, however, not new; it is commonly used, andwas first described by Liebermann and Seyewetz.76 According toF. U ~ Z , ~ ~ when picric acid is heated with sodium hydroxide andhydrogen peroxide, the whole of the nitrogen is obtained as nitrate,and may be estimated by the " nitron " method, whilst 34. Buschand G. Blume 78 show that picric acid may be estimated by weighingit as " nitron " picrate; halides and their oxygenated salts, nitrates,nitrites, and chromates must be absent.F. Raschig79 gives amethod for estimating m-cresol in presence of the 0- andpisomerides ; it is adversely criticised by J. Rerzog.soThe methods of estimating starch in cereals, which depend ondetermining the reducing power after hydrcjlysis with either diastaseor acid, or with both successively, are lengthy and inaccurate,since reducing sugars other than those originating from the starchare invariably present among the products of hydrolysis. AlthoughRoll. cJiL',ii. fn?'jI)., 1907, 46, 861 : -A!., ii, 139.;" Z i l s c h . nnn?. CJ1e7)7., 1908, 47, 682 ; - I . ? ii, 96:;.]bid., 6 S i ; -1.. ii, 996.j 2 Analyst, 1908, 33, 261.8 . ' Chem.Zezt., 1908, 32, 75 : A , , ii, 235.Ibid., 14s ; A., ii, 232.75 Contpt. rend., 1908, 146, 132 ; A., ii, 2.26.iG Ber., 1891, 24, 788 ; A., 1891, 681.7i Zcitsck. m a l . Chwz.. 1908, 47, 140 ; .4., ii, 233.7s Zcitsch. a7~gew. CJwn., 19OS, 21, 354 ; lf., ii. 328.79 PJiccl-m. Zeit., 19OS, 53, 99; A., ii, 233.-.Zhl'd., 141 ; A., ii, 233202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.no known method gives anything but approximate accuracy, inthe writer’s hands the most satisfactory and rapid method is theDubrunfaut-Effront, which consists in triturating the ground cerealwith concentrated hydrochloric acid and polarising the solublestarch. proposed a modification of thismethod, and later 0. Wengleins2 suggested the use of sulphuricacid (D 1.7) instead of hydrochloric, under which conditions therotatory power of barley starch is found to be [.ID 191.7O.Lintnerhas confirmed Wenglein’s results,83 and adopts his suggestions.E. Ewers84 points out that substances other than starch are dis-solved, and that the results are thereby vitiated. He proposesmodifications, his latest suggestion 85 being treatment with one percent. hydrochloric acid a t looo, and clarification with ammoniummolybdate, before polarising. I n connexion with sugars, Barfoed’scopper acetate solution was put forward as one which was notreduced by maltose and lactose, and F. C. Hinkel and H. C.Sherman 86 have determined the conditions under which in a mixtureof dextrose and the reducing bioses mentioned, only the formerexhibits reducing power.F. Watts and H. A. Tempany87 recom-mend the use of dry basic lead acetate for clarifying commercialsugar solutions. H. C. Prinsen Geerligs 88 points out that the errordue to the precipitation of laevulose only occurs in the case ofcommercial samples containing impurities precipitable by the leadreagent, whilst 0. Schrefeld 89 states that this source of error is tobe avoided by the employment of neutral lead acetate. F. Wattsand H. A. Tempany 90 recommend the Fehling-Violette solutionas the least liable to auto-reduction. I n the estimation of invert-sugar in presence of sucrose, they find that one gram of the latterexerts a reducing power equal to 0.0033 gram of invert-sugar. Thewriter and T. Rendleg1 find that sucrose has no influence on theestimation of invert-sugar until its amount exceeds 30 per cent.of the total sugars; with a mixture of equal parts of the sugar,the invert-sugar would be over-estimated by 0.8 per cent.,whilst whenthe invert-sugar only represents one per cent.of the mixture, theLast year C. J. LintnerZeitseh. ges. Brauwescn, 1907, 30, 109 ; cotnpnre A . , 1907, ii, 823.Zeitseh. Nahr. Genicssm., 1908, 16,’509 ; A . , ii, 1077.82 B i d . , 1908, 31, 53.s4 Zcitsch. ofcntl. Ckrn., 1908, 14, 150; A., ii, 543.86 Chem. B i t . , 1908, 32, 996.8G J. Amer. Chem. SOC., 1907, 29, 1744 ; A., ii, 235.s8 Intcrn. Sugar J., 1908, 10, 500 ; A . , ii, 990.gR Zcitsch. Vcr. dcut. Zzcckerind, 1908, 947 ; A . , ii, 1 O i G .91 Analyst, 1908, 33, 167 ; A ., ii, 542.J. SOC. Chem. Ind., 1908, 27, 53 ; A., ii. 236.J. SOC. Chenr. Ind., 1908, 27, 191 ; A., ii, 437ANALYTICAL CHEMISTRY. 203amount returned may be 14 per cent. too much. These resultsconfirm those of Watts and Tempany,92 who, however, dealt onlywith high proportions of sucrose to inverbsugar. The writer andG. C. Jones 93 have shown that the volumetric method of estimatingreducing sugars, using ferrous thiocyanate as indicator, gives resultsquit2 as accurats as the gravimetric method, and is far more rapid.The writer would point out, however, that with commercial products,such as molasses containing iron, the ferrous thiocyanate indicatorcannot be used. It is well known that the rotatory power oflmmlose decreases as the temperature is raised, and that at 8 7 Oit is equal but opposite in sign t o that of dextrose, so that equalamounts of dextrose and lzvulose are optically inactive a t 8 7 O .For the analysis of commercial inverbsugar, the measurement ofthe change or rotatory power with rise of temperature is useful,and the apparatus described by A.P. Sy 94 for making polarimetricdeterminations at high temperatures is much to be appreciated.T. W. Harrison and F. M. Perkin95 find that the Valenta methodis untrustworthy for the estimation of tar oils in admixture withmineral oils, the latter being not absolutely insoluble in methylsulphate.96 W. H. Emerson 97 has redetermined the solubility ofstearic acid in alcohol a t Oo for the purpose of the Hehner-Mitchellmethod.R. K. Dons98 describes a modification of his method ofdetermining the caprylic acid value in butter fat. J. Lewkowitsch 99gives constants of, and other information on, carapa oil; and1 hepublishes constants of ochoco fat from the seeds of one of theMyristicacez. M. Tsujimoto gives some constants of Japanesetea oil. Such processes of determining unsaturated fats as thoseof Hub1 and Wys (iodine absorption) are often used as mereempirical tests ; the scientific principle underlying them is broughtout, however, by S. Fokin’s experiments,3 showing that the sameresults may be obtained by determining the hydrogen value (c.c.of hydrogen a t Oo and 760 mm. absorbed by one gram of thes~bstance).~ H. Matthes and 0. Rohdich,5 working on 13 kilos.of92 LOC. eit.94 J. Amer. Chcm. Xoc., 1908, 30, 1790 ; A . , ii, 1076.95 Analyst, 1908, 33, 2 ; A . , ii, 135.9f J. Amar. Chem. Soc., 1907, 29, 1750 ; A . , ii, 236.O8 Zeitsch. Nahr. Genzcssm., 1908, 15, 75 ; A., ii, 238.93 Analyst, 1908, 33, 160 ; A., ii, 541.Compare Graeffe, Ann. Beport, 1907, 211.Analyst, 1908, 33, 184.Ibid., 313 ; A., ii, 885.Chcm. Bev. F4t FIurx. I d , 1908, 15, 224.J. nZus. I’h~y?. Chem Soc., 1908, 40, 700 ; A., ii, 637.In connexion with the chemistry of Wys’ solution, see H. Ingle, J. SOC. C‘Ima.de?.., 1908, 41, 19 ; A . , i , 199.I ? d , 1908, 27, 314204 ANNUAL REPORTS ON THE PROGEESS OF CHEMISTRY.cocoa butter, failed t o isolate any constituent to which the character-istic odour could be attributed.From the unsaponifiable matterthey isolated amyrilene, C,,H,,. H. Matthes and E. Ackermann6point out that cocoa fat contains two phytosterols, the acetyl-tetra-bromides of which melt a t 180° and 1 3 2 O respectively. Thecholesterol of butter does not form an acetyl-tetrabromide. Theethyl ester value of fats is a new constant devised by J. Raniis andL. hekl C. Fleig 8 has carriedout a series of experiments which, on the whole, support XIylius’scontention that the Camoin-Baudouin colour reaction of sesame oiland Pettenkofer’s similar reaction of bile acids are due to thefurfuraldehyde produced by the mineral acid on the sugar, but theevidence is not conclusive, since lzvulose and sucrose give betterresults than certain pentoses. He also shows that the furfural-dehyde in Villavecchia and Fabris’s reagent may be replaced byother aromatic aldehydes.C. H.Hertyg draws attention to the wide variations in theoptical activity of samples of turpentine from trees grown on thesame farm in Florida. F. W. Richardson and J. L. Bowen10 haveinvestigated various methods of detecting and estimating adul-terants in turpentine, one of the conclusions being that refracto-metric determinations of the distilled fractions give some of themost useful data.11 C. T. Bennett 12 shows that for the estimationof cineol in eucalyptus oil, Schimmel and Co.’s resorcinol methodi s untrustworthy, and he points dut that the fraction of the oilboiling between 175O and 1 8 5 O consists mainly of cineol.A. Bloch l 3estimates citral in lemon-grass oil by removing it as the bisulphitecompound. E. M. Chace14 shows that 2 per cent. of turpentinemay be detected in lemon oil by conversion into pinene nitroso-chloride and examination of the crystals mounted in olive oil underthe microscope. P. Jeancard and C. Satie15 give the opticalactivity, specific gravity, and ester value of samples of Alpinelavender oil distilled in different years, whilst M. Daufresne 16 hasdetermined some constants of French and German oil of tarragon.for the detection of cocoanut oil.ti I!cr., 1908, 41, 2000 ; A . , i, 637.Zcitsch. Nahr. GenzLssm., 19OS, 15, 5 i 7 ; d., ii, 641.8 Bull. SOC. chim., 1908, [iv], 3, 984, 992 ; A . , ii, 994.‘J J. Amer. Chcm. Soc., 1908, 30, 8 6 3 ; A., i, 434.lo J.SOC. Chem. Ind., 1908, 27, 613. ~l2 Chemist and Drisggist, 1908, 72, 55.l 3 IIulZ. Sci. Pharrnacol., 1908, 15, 72 ; A . , ii, 782.14 J. A m e T . Chem. Xoc., 1908, 30, 1475 ; A., ii, 908.l5 Bull. J‘oc. chim., 1908, [iv], 3, 155 ; A . , ii, 232.l6 Bid., 300 ; compare d., i, 436.See also A. K. Turner, Oil mid Coloirr Trades J . , 1905, 503ANALYTICAL CHEMISTRY. 205S. S. Pickles17 gives some constants of origanum oil, from whichhe has isolated a new terpene, origanene.Among papers dealing with the chemistry of the proteins, thefollowing may be mentioned: G. T. Matthaiopoulos 18 makes use ofthe fact that casein forms a definite compound with sodiumhydroxide, in order to estimate it (volumetrically) in milk. Hisresults confirm Laqueur and Sackur’s observation that the molecularweight of casein is 1135.6. F. Cross, E. J. Bevan, and J. F.Brigs19 have extended the work of F. Raschig,2O and have shownthat, like ammonia, the proteins and their derivatives form chloro-amines by the action of hypochlorites. These chloroamines liberateiodine from potassium iodide, and the presence of proteins in anorganic tissue may be located by first steeping it in an acid solutionof bleaching powder, and, after washing, removing the excess ofchlorine by immersion in 2 per cent. sodium phosphate solutiona t 4 5 O , and finally treating it with a solution of potassium iodideand starch: a blue stain will be produced in those parts in whichproteins occur. R. H. Aders Ylimmer and F.H. Scott21 find thatwhen phosphoproteiiis are digested with a one per cent. solutionof sodium hydroxide for twenty-four hours a t 3 7 O , the whole ofthe phosphorus is eliminated as phosphoric acid. This serves,therefore, as a means of distinguishing these compounds from thenucleoproteins. S. P. L. Sorensen 22 proposes to measure the amino-acid formed by the hydrolysis of proteins by a method based onH. Schiff’s observation that the basic function of these compoundsis annulled by the formation of the group N:CH, after treatmentwith formaldehyde, the carboxyl group being then titrated withalkali hydroxide, using phenolphthalein or thymolphthalein asindicator. The reaction of the amino-acids, formaldehyde, andalkali is reversible, but when thymolphthalein is employed asindicator an end point (bright blue colour, obtained by four dropsof rV/5 barium hydroxide in excess of that required to producethe first colour indication) may be chosen such that the concentra-tion of the hydrogen ions is as low as 10-9.7.23 To measure therate of proteolysis, Griitzner has proposed to estimate the carminliberated from fibrin stained with that dye, but H.E. Roaf24 statesthat Congo-red may with advantage be substituted for carmin.I’ P ~ v c . , 1903, 24, 05.Zeitsch. and. G‘lum., 1908, 47, 492 ; A., ii, 783.J. SOC. CIienr. I d . 1908, 27, 260 ; A . , i, 374.211 L‘T., 1907, 40, 4586 ; Citein. Zeit., 1907, 31, 126 ; Zeitszh. mayew. Chem.,’’? Big cJwm. Z E Z ~ ~ L . , 19Oi, 7, 45 ; A . , i, 115.“3 See, fuitlier, S.P. L. Sorensen aiid H. Jesseri-Hansen, ibid., 1908, 7, 407 ; A . ,1907, 20, 2065 ; A., ii, 30. 21 Trans., 1908, 93, 1699.ii, 334. 24 Bioclzc?~~. J., 1908, 3, 188 ; A., ii, 743206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n the analysis of organic substances, increasing use is beingmade of physical methods, and numerous papers. have appearedrecently on the estimation of total solids in molasses, wort, beer,wine, spirits, etc., by means of the refractometer, which can alsobe used for the estimation of alcohol. The method is principallyto be recommended on the score of its rapidity, although in thehands of a skilful worker in a properly equipped laboratory thedetermination of specific gravity can be carried out very rapidly.On account of the heterogeneous composition of many commercialproducts, notably the varying amounts of mineral matters present,special tables must be constructed for each kind of product.Forpractical purposes the assumption that all sugars in solution oflike concentration have the same refractive index is quite justified.Tables have been prepared for sugar products by H. Main25 andby H. C. Prinsen Geerligs.26 H. Bryan,27 using Geerligs’s tables forhoney, syrups, and molasses, finds that the results are in closeraccord with the actual determinations of solid matter than arethe values obtained by the specific gravity method from Brix’stables. It should be pointed out, however, that this is not due toany defect in the specific gravity method.C. Mai and S. Rothen-fusser28 give a valuable rQsum6 of the application of the refracto-metric method of detecting the addition of water to milk.From the examination of 5000 samples, they find that thenormal refractometer value for milk is 39 divs.; any samplegiving a lower reading than 36.5 divs. contains added water.The process fails with sour milks. The application of themethod to the estimation of extract in wort is dealt with by0. M0hr,2~ and to that of alcohol and extract in beer and spiritsby J. Race.30 A. Frank31 observes that the indirect estimation ofalcohol by refraction before and after expelling the alcohol isuntrustworthy. M. Duboux and P. Dutoit 32 describe a new methodof estimating alcohol in wine; it depends on the determination ofthe temperature a t which a clear solution is formed when a fixedamount of the wine distillate is added to a fixed amount of amixture of aniline or nitrobenzene and alcohol.Some useful datain the pyknometric estimation of alcohol in fermented liquids, witha description of new apparatus, is given by W. Antoni.3325 International Sugar J., 1907, 9, 481.27 J. Amer. Chena. Xoc., 1908, 30, 1443.Zeitsch. Nahr. Cenzusm., 1908, 16, 7.Wochensch. Brau., 1908, 25, 454.30 J. SOC. Chm. Jnd., 1908, 27, 544, 547 ; A . , ii, 738.Chem. Zeit., 1908, 32, 569; A., ii, 687.32 Ann. Chim. anal., 1908, 13, 4 ; A,, ii, 136.:ja J. Amr. Chem. Soc., 1908, 30, 1276; A . , ii, 902.26 Ibid., 1908, 10, 68ANALYTICAL CHEMISTRY. 207M. E. Pozzi-Escot 34 describes a volumetric method of estimatingtart8aric acid in wine, whilst the Goldenberg method has beeninvestigated by the Cheniische Fabrik vorm.Goldenberg, Geromontand C0.,35 and conditions laid down whereby accurate results maybe obtained. L. Gowing-Scopes 3G has submitted J. von Ferentzy’smethod of estimating tartaric acid in presence of other acids37 toa critical examination, and finds it trustworthy. A. Hubert 38 hasmade the interesting observation that citric acid occurs naturallyin wines. This has been confirmed by H. Astruc 39 and by G.Denigks,*O who suggests that the reason the acid cannot be detectedin old wines is to be ascribed to bacterial influences. E. Dupont 41states that Denigks’s mercury method of detecting citric acid maybe made approximately quantitative. G.Favrel 42 proposes a testwhich depends on the forrnatisn of acetonedicarboxylic acid (whencitric acid is heated with sulphuric acid). This ketonic acid gives aviolet coloration with ferric chloride.P. Dutoit and I$. Duboux43 show that by adding successivequantities of barium hydroxide to a wine, and determining its elec-trical conductivity after each addition, it is possible to estimateconsecutively the sulphates, total acidity, and tannin substancespresent. Under the name of “ abrastol,” calcium P-naphthol-a-sulphonate is added to wine as an antiseptic and precipitant oftartrates. The acid may be extracted by amyl alcohol, andidentified by the reddish-violet coloration formed on evaporatingwith mercurous nitrate.I n connexion with brewing materials, A.C. Chapman44 hasdevised a valuable method of estimating tannin in hops byweighing the cinchonine compound, and G. C. Jones4“ has com-municated two papers on malt analysis.The paper by J. S. Ford and J. M. Guthrie,46 on the biochemistryof barley, adds considerably to our knowledge of the nature of theamylolytic enzyme of barley, and the methods they adopt are mostinteresting and suggestive. J. Wohlgemuth’s ~uggestion,~~ tomeasure diastatic activity by estimating the quantity of a diastatic. -34 32111. Xoc. chim. Belg., 1908, 22, 218 ; A., ii, 740.35 Zeikch. anal. Chem., 1908, 47, 57 ; A., ii, 237.36 Analyst, 1908, 33, 315 ; A.! ii, 905.:;’ See Ann. Report, 1907, 217.39 Ibid., 224 ; A., ii, 640.41 Ibid., 338 ; A., ii, 904.43 Compt.rend., 1908, 147, 134 ; A., ii, 781.44 J. Inst. Brewing, 1907, 13, 646.45 Ibid., 1908, 14, 9, 13.46 ]bid., 61 ; A!., ii, 218.Ann. Chiin. anal., 1908, 13, 139 ; A., ii, 544.4o Ibid., 236 ; A., ii, 640.4iz Ibid., 177 ; A . , ii, 640.B o c h e n t . Zeitsch,., 1908, 9, 1 ; A.: ii, 444208 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.solution necessary to hydrolyse soluble starch to the stage a t whichthe products no longer give a coloration with iodine, assumes thatthis is a linear function of the time, which has not been proved,and the same argument applies to W. A. Johnson’s method,lBalthough this author does compare the iodine results with thoseobtained by the cupric reduction method. C. J. Lintnef49 showsthat the law of proportionality for malt diastase holds good up toa reducing power of 35 (calculated as maltose). He adopts thewriter’s method of estimating diastatic activity. J. L. Baker andH. F. E. Hulton50 and J. S. Ford and J. M. Guthrie51 havepublished two most important papers on the question of theso-called “ strength ” of flour in its relation to enzymes. L. Briegerand J. Trebing52 call attention to the antitriptic power of humanblood-serum, and von Bergmann and K. Meyer 53 give a methodfor the measurement of its activity.W. Thorner54 describes a method of estimating water in foods,consisting in distillation with petroleum and collection of the dis-tillate in a graduated receiver, in which the water separates and itsvolume may be read off. The method is similar to that ofHoffrnann,55 and of Aschnian and Arend.56H. D. Richmond,57 in his annual report on milk, based this yearon the analysis of 35,331 samples, adds to our knowledge of thesubject. EIe has examined eight samples of human milk, and pointsout that the fat varied from 1.7 to 5.7 per cent. He draws attentionto a preservative xhich he has found in certain samples of milk,naiiiely, formic acid, mixed with dextrose. W. R. G. Atkins 5sstates that determinations of the freezing point and specific gravityof milk are sufficient to show if water has been added or Patremoved. The freezing point of milk is practically a constant,namely, 0.55O.A. Kreutz59 shows that after heating cocoa in a, flask on thewater-bath with chloral alcoholate until a homogeneous paste isobtained, the fat may be extracted by warming with successivequantities of ether. The chloral is all driven off by heating the4g J. Amcr. Chem Soc., 1908, 30, 798 ; A!., ii, 743.ao J. s’oc. Chcm I n d . , 1908, 27, 368.5l Ibid., 389.jy Bcrliz Ktin. TVocheiwdL., 1908, 45, 1041.B3 Ibid., 1673.ri4 ZciilscJt. nngctc. Chcwz., 1908, 21, 148 ; A . , ii, 222.35 Wochemch. Brau., 1902, 19, 572.jti Ufiem. Zeit., 1906, 30, 953 ; A . , 1906, ii, 814.57 A?zuEyst, 1908, 33, 113.s8 Chenb. News, 1908, 97, 241 ; A . , ii, 641.ZeztsclL. yes. Braz~wesen, 1908, 31, 421.Zeitseh. Nahr. Geitussna., 1908, 15, 680 ; 8., ii, 641ANALYTICAL CHEMlSTRY. 209fat at 1 1 0 O . The results agree well with those obtained by theordinary method. Later,6" he shows that the theobromine isextracted along with the fat by this method; when treated withcarbon tetrachloride the fat alone is dissolved, leaving the theo-bromine, which may be weighed.P. Biginelli61 draws attention to the fact that when tannic acidis used as a precipitant for alkaloids in toxicological investigations,it also forms insoluble compounds with certain solvents and mineralacids. L. Dreyer 62 describes the differentiation of tubercular fromordinary pus by its behaviour towards Millon's reagent. It is wellknown that the formation of indole from proteins is a characteristicof certain microbes, and C. Porcher63 proposes to detect indole inpus by its colour reaction with p-dimethylaminobenzaldehyde.ARTHUR R. LING.6o Zcitsch. Nahr. Gcnttssm., 1908, 16, 579.G1 Gazxetta, 1907, 37, ii, 506 ; A., i, 40." illilnch. Mcd. TVocke,wcl~., 1906, 55, i 2 8 .63 C'ompt. rend., 1908, 147, 214 ; A., ii, 769.REP.-VOL. V.

ISSN:0365-6217    

DOI:10.1039/AR9080500180

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.THE output of biochemical papers shows no sign of abatement,and one has also to chronicle the appearance of several new text-books on the subject during the past year. Carl Oppsnheimer, ofBerlin, is editing a very complete Handbuch der Biochemie, whichis to consist of twenty parts, and of these six have already appeared.The various articles in it are written by those who have paidparticular attention to the portions of the subject on which theywrite, and the chapters deal with the questions involved from boththe chemical and biological point of view. Another new text-bookis from the pen of Professor Rohmann. Abderhalden’s book hasbeen translated into English, and a second edition of the Germanversion is just to hand. Messrs. Longmans have commenced theissue of a series of important biochemical monographs under theeditorship of Drs.F. G. Hopkins and R. I€. Aders Plimmer; thefirst of these is written by Dr. Bayliss, and treats of the enzymes,particularly emphasising the catalytic nature of their action. Thenext two monographs are by Dr. Plimmer, who deals with theproteins, first as a whole, then of their cleavage products, andfinally of the attempts which have been to synthesise them. Dr.H. M. Vernon, of Oxford, has published the lectures he gave atthe University of London in the form of a book, entitled “ Intra-cellular Enzymes ”; here the part played by fermer,ks in the innerlife and metabolism of the cell is described, so far as we can a tpresent recognise such action. Dr.Vernon himself, by his dis-covery, among other things, of tissue-erepsin, has done much toelucidate this obscure and comparatively new aspect of fermentactivity, and of the importmame of such action there can be noquestion. There is, however, a tendency just now to attribute allthe chemical transformations which occur during life to enzymaticaction, and there is a danger that this idea may be overdone.Ferments may be the exclusive agents which protoplasm employs,but the proof that such agents are really ferments is, in many cases,very insufficient, and it is quite possible that, as knowledgeadvances, other mechanisms may be brought to light. In thPHYSIOLOGICAL CHEMISTRY. 211eighteenth century ‘ I vital force ” was supposed to be a t the bottomof all that could not be otherwise explained, and the conceptionof a force which no one hoped ever to understand delayed theprogress of science. We must take care in the twentieth centurythat the adoption of a new phrase, “ferment action,” is not con-sidered in itself to be a final solution of vital problems.To labelany particular chemical change as due to enzymatic activity shouldbe rather a signal for the commencement of renewed research inattempts to understand it still further.The journal familiarly known as Hofmeister’s Beitriige has dis-appeared in the struggle for existence, having been absorbed in thecomparatively youthful Biochemische Zeitsciirif t. During the fewyears this last-named publication has existed, fourteen volumes havealready appeared, and if we judge fruitfulness by quantity alone,certainly the Biochemische Zeitschrif t has been successful in aphenomenal way.I f we examine the articles published there, thequality is also of a high standard.I n selecting from the papers of the past year subjects for moredetailed and critical review, the difficulty, as usual, arises from anenzbai*ras des ?ichesses, for hardly any aspect of biochemical know-ledge has been omitted from the mass of material published. Mostof this relates to subjects which have been previously noticed inthese Reports, and works out further details which support orcorrect views already expressed. This patient exploration ofportions of the field which had escaped, or almost escaped, noticebefore, is most necessary and most praiseworthy, but it must beconfessed that, as a rule, it is also extremely dull, and hardly lendsitself for interesting treatment in an article of this nature.Theactivity of many workers among the ferments has already beenalluded to. I n the forthcoming index Abderhalden’s name will loomlargely, and his work on the polypeptides and cleavage productsof the proteins progresses in a steady stream of published papers;each one of these is a brick in the edifice of knowledge which isslowly being reared, but it may be many years before we are ableto obtain a clear view of the final construction. I n America,Osborne and his colleagues are pursuing similar work, especiallyon the vegetable proteins, and data there are being accumulated,the final evaluation of which is also for the future.Nucleic acid,that important appendage of many proteins, has received its dueshare of attention, and here it does seem that we are in a positiona t last to reduce the chaos of former years to something like order;nucleic acid, therefore, will form the subject of a fuller paragraphlater in this Report. The work of London and his collaborators intheir important study of digestion, which formed the subject of aP 212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.lengthy section in last year’s Report, progresses rapidly, and thislist of papers promiscs to rival in number those of Abderhalden;here again, however, the work has been the pigeon-holing of freshdata, and presents nothing of really new importance; this passingreference will, therefore, be all that I shall attempt this year inrelation to this branch of research.Although so little is known of creatine and creatinine as test-tube products of protein fission, their importance as products ofthe body’s katabolism is rising into prominence. The work directedfrom so many quarters to the study of these two substances datesa few years back to Folin’s investigations, and to the simplemethods he then introduced for detecting and estimating them.Although I devoted some pages last year to this subject, it will benecessary to return to it again, because an entirely new light hasbeen shed upon it by the remarkable work which Mellanby isresponsible for.Perhaps, however, the most noteworthy feature of biochemicalresearch to-day is the recognition of the importance of the lipoidsin cell life, and, therefore, a section of my Report will be occupiedwith these materials.Fresh information on the functions of the pituitary body,hitherto a subject on which we have been almost completelyignorant, has shown us the importance of this gland, both in healthand disease. Although the chemical side of the subject is as yetfar from clear, I propose to conclude my Report with a briefsummary of our present knowledge on this outgrowth of the brain.Without, however, enumerating all the sub-headings of my Report,let us a t once proceed to break it up into its various sections, andI will commence with a brief consideration of one I have not yetmentioned, namely :Protein Nomenclature.Fellows of the Chemical Society will be well acquainted with thedifficulties which attend any efforts at uniformity of terminology,and, although in our own Journal the rules about the use of suchterminations as in and h e , or of 02 and ole, are enforced, therecommendations of the Nomenclature Committee are more oftenhonoured in the breach than in the observance in other publications.This difficulty is enhanced when people speaking and writing otherlanguages are concerned.Although the nomenclature of theproteins is, and probably for long will remain, very unsettled untiltheir constitution is better known, a joint committee of theChemical and Physiological Societies sat, a year or two ago, toattempt a settlement of the more salient points, and the reporPHYSIOLOGICAL CHEMISTRY.213which this committee presented was sent over to America in orderto try and obtain uniformity in the use of names between the twogreat sections of English-speaking men of science. The report wasalso considered at the International Congress of Physiology, whichwas held last year a t Meidelberg, and although it was not receivedwith enthusiasm, we may, a t any rate, claim that the adoption ofthe word Protein as the title for the great group of albuminoussubstances by German writers is, a t any rate in part, due to ourefforts.But to return to America, for there a t least we should hope tobe successful, the report was considered by a joint committee ofthe American Physiological Society and the American Society ofBiological Chemists, and during the last year they have publishedtheir views.1 One notes with satisfaction that the American reportis in substantial agreement with our own.The points of differenceare small ones, and the chief improvement in the American classi-fication is the inclusion of the chief classes of the vegetable proteins;here the hand of T. B. Osborne, who was a member of the Americancommittee, is traceable.The main points of difference and agreement may be best statedby the following quotations from a report prepared by the ProteinNomenclature Committee of the Physiological Society, which wasadopted a t a meeting of that Society in May last 2 :“The term AZbum‘noid is retained for the sub-class namedSclero-proteins in the English report.We think the adoption ofthe new word is preferable to the retention of the old one, becausethe name albuminoid is still largely used by English and Frenchchemists as synonymous with Protein:‘ I The only noteworthy difference in the arrangement of the sub-classes is the transference of the phospho-proteins (vitellin-caseinogen group) from the simple to the conjugated proteins. Weadhere to the opinion that our own arrangement is better, becausethe phosphorus-containing group of the phospho-proteins is notsplit off from them as a true prosthetic group is, and the cleavageproducts of this class of protein still contain phosphorus.3“ A minor difference is the substitution of the term hzemoglobinsAmw.J. Physiol., 1908, 21, sxvii-xxx ; J. Biol. Chem., 1908, 4, xlviii-Ii;Proc. physiol. Soc., 1908, xxxii-xxxv ; J. Physiol., 37.This view, that phosphorus is part of the protein molecule, and not part of agroup such as nucleic acid linked to the protein, is emphasised in Dr. Plimmer’sbook already mentioned. See also paper by Plimmer (Trans., 1908, 93, 1500),which treats of vitellin, and also of a second protein in egg-yolk (livetin) which isalmost free from phosphorus. See also Plimmer and Scott on the distinctionsbetween phospho-proteins and nucleo-proteins (ibid., p. 1699).A., i, 301214 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.for the class called chromo-proteins in the English report.prefer the latter name as having the wider significance.the American report. These are:Wc“ Five additional substances are introduced a t various places in“ 1.The glutelins, the alkali-soluble proteins of vegetable origin.(‘ 2. The alcohol-solzcble proteins found in the vegetable world.“We think the inclusion of these two new classes of simpleproteins (and especially the latter) is advantageous, as it makesthe system more complete. We are prepared to accept, provision-ally, the term glutelin for the proteins soluble in alkali, althoughthey are doubtless closely allied to the globulins. The termalcohol-soluble proteins strikes us as rather cumbrous ; these sub-stances might, as Rosenheim * has suggested, be termed gliadins ;that is, the name of the principal member of the group might beextended to serve as a class name.(‘ 3.The Zecitho-proteins are added to the classes of conjugatedproteins. As it has not yet been decided whether these aremechanical mixtures, adsorption compounds, or true chemical com-binations, we see no reason for the inclusion of this group.4. The proteam : insoluble products which ‘ apparently resultfrom the incipient action of water, very dilute acids or enzymes.’‘( 5. Coagulated proteins: which result from the action of heator of alcohol.“Sub-classes 4 and 5 are placed among the primary proteinderivatives; they are of an ill-defined nature, and we see no objectin singling out for special mention a few of the infinite varietiesof insoluble modifications which proteins exhibit.”The final result of this consultation with our American confrtresis the classification of proteins into the following groups:1. Protamines.2.Histones.3. Albumins.4. Globulins.5. Glutelins.6 . Gliadins.7. Phospho-proteins.8. Sclero-proteins.9. Conjugated proteins :a. Nucleo-proteins.6 . Chromo-proteins.c. Gluco-proteins.Proc. ph?ysio7. Soc,, 1908 ; J. Physiol., 36, Iv ; Scimcc Progress, 1908. 2,696PHYSIOLOGICAL CHEMISTRY. 21510. Protein derivatives :CL. Meta-proteins (acid-albumin, etc.).b. Proteoses.c. Yeptones.d. Polypeptides.It is, of course, impossible, a t this stage in the history of protein-chemistry, to obtain absolute unanimity on minor points of classi-fication and nomenclature; but the system is now complete forpractical purposes, and its utility can only be proved by giving ita fair trial.I n the new text-books on the subject, it is alreadybeing adopted.Caseinogen and Rennin.It is an undoubted fact that the milk provided by Nature forthe growing offspring is different in the various classes of theanimal kingdom. The quantitative variations are often enormous,and it has been shown that the milk best adapted for the nutritionof the young animal is that which comes from its mother, or, a tleast, from an animal of the same species. The practical applica-tion of this rule comes home to most of us when dealing with thefeeding of children, and it is universally acknowledged that, afterall, cows’ milk is but a poor substitute for human milk.Cows’milk is, of course, diluted, and sugar and cream added, so as tomake it quantitatively like mothers’ milk, but even then thequestion arises whether the essential difference between the twokinds of milk is not deeper than one of mere quantity; and, inparticular, the pendulum of scientific opinion has swung backwardsand forwards in relation to the question whether the principalprotein, called caseinogeq, in both is really identical in the twocases. The caseinogen of human milk curdles in small flocculi inthe stomach, so contrasting with the heavy curd which cows’milk forms; and even although the curdling of cows’ milk bemade to occur in smaller fragments by mixing the milk withbarley-water or lime-water, its digestion proceeds with comparativeslowness in the child’s alimentary canal.These are practicalpoints well known to every clinical observer, and in the past theyhave been attributed, not so much to fundamental differences inthe caseinogen itself, as to accidental concomitant factors; theexcess of citric acid in human milk, for instance, or its paucityin calcium salts, having been held responsible for the differencesobserved in the physical condition of the curd and in its digesti-bility.This question is far from settled even to-day, but there ar216 ANNUAL REPORTS ON THE PROGRESS OF CHEMJSTRY.some data now available that point to a qualitative differencehetween caseinogens. Some of these depend on the application ofthe “ biological test ” carried out on the line of immunity experi-ments, which method has been so signally successful in the distinc-tion between the blood-proteins of different species of animals.Thedifferences, however, which lead to the formation of specific pre-cipitins are so slight, that ordinary chemical methods of analysisare, at present, unable to reveal them. But, in the case of milk,there are differences which the chemist can detect. One cannotlay much stress on mere percentage composition, although differ-ences have been noted in that, because we have no guarantee thatthe proteins investigated were separated from all impurities.Differences are also noticeable in the yield of monoamino-acids, butthe methods a t present employed in the estimation of these cleavageproducts are far from perfect. A deeper chemical distinctionnoted is, however, mentioned in the recent work of Bienenfeld,5who find that human caseinogen contains a carbohydrate complex,which, as is well known, is absent from that of the cow.A few years ago it was stated that human caseinogen will notcurdle with rennet, and Bienenfeld upholds this view; but itappears to be a mistake.The conditions of rennet curdling aresomewhat different in the two kinds of milk we are considering,and the factors concerned in this phenomenon in human milk havebeen worked out by Jacoby? who has paid special attention tothe action of anti-rennin, by Fuld and Wohlgemuth,’ who criticiseBienenfeld’s observations, and by Engel,* who deals mainly withthe influence of reaction.Another problem closely related to the preceding is the viewwe are to take of the ferment rennet or rennin itself.Rammar-sten’s authority is the one usually relied on for the statementthat gastric juice contains two distinct enzymes, pepsin,the proteoclastic ferment, and rennin, the milk-curdling one. Itwas Pawloff who first suggested that the rennetic action was thework also of the peptic enzyme; and Ehrlich’s convenient side-chain theory was considered to explain the double action, thecurdling being the result of the activity of one or more moleculargroups in the pepsin molecule. It is a little early to argue inthis manner, for, as Emil Fischer so wisely said in his Faradaylecture, nobody has yet ever been successful in separating out anyenzyme in a state of purity.For the same reason, one must feelchary in accepting as proved the recent statements made byRioclrem. %oitsdt., 1907, 7, 262 ; A . , ii, 121.Ibid., 376 ; A., ii, 311.ti Ibid., 1908, 8, 40 ; A . , i, 236.F Ibid., 1908, 13, 89 ; A., ii, 873PHYSIOLOGICAL CHEMISTRY. 21 7SScala.9 that rennin is a weak base consisting of a proteose nucleusand amino side-chains. However this may be, Gewin10 has cham-pioned Pawloff’s view, and maintains that pepsin and rennin arcone and the same ferment. He regards the rennet action as thefirst stage in the digestion of caseinogen. I f hydrogen ions areabsent and calcium ions are present, digestion stops and a curdseparates, but if a sufficient number of hydrogen ions are present,ordinary peptic digestion proceeds.Unfortunately, there appear to be as many and as eminentauthorities ranged on the opposite side, and during the last yearI.Bang 11 and Hammarsten 12 himself have published papers whichconclude that the two ferments are not identical.The question is an interesting one, and, perhaps, in some futureyear, we shall be abIe to relate how it has been finally settled.PZasteins.-It has long been known that the addition of rennetto a solution of “peptone” causes the formation of a precipitate,and the name plastein was given to the precipitated substance.The same occurs when gastric juice, or pepsin-hydrochloric acid, isadded to ‘( peptone ’’ solution, so the formation of plastein is notdistinctive of rennet, even if that enzyme is not identical withpepsin. When the discovery was first made, it was supposed thatone of the actions of the rennetic enzyme was to produce theregeneration of albumin ” ; this was a t a date when the exclusiveseat of the synthesis of protein from its cleavage products wassupposed to be the wall of the alimentary canal, the seat of absorp-tion.Recent research has done something to confirm this view ofthe composition of plastein, but in modern terminology we speak ofit now as the reversible action of the enzyme concerned. This viewis taken by Sawjaloff,l3 and the analytical figures he gives indicatethat the reaction is either bimolecular or termolecular. Plastein is,therefore, the result of the union of either two or three molecules ofthe proteoses from which it is formed, and its molecular weight is, onthe average, twice that of the proteoses. The plasteins used wereprepared from a large range of proteins, and an attempt is madeto classify them.Levene and van Slyke14 have made similarexperiments, and obtained the cleava,ge products of plastein ; theseinclude both mono- and di-amino acids; the total yield, however,only amounted to 39 per cent. Their conclusion as to the com-position of plastein is different from that of Sawjaloff; they regardit as a complex protein not far removed in composition from fibrin,Stnz. .~periin. agrar. itmb., 1907, 40, 129 ; A., i, 236.lo Zeitsch. physiol. C7~e?n., 1907, 54, 32 ; A., i, $1l1 Ihid., 359 ; A ., i. 236.l4 Bioclwnz. Zeit,oc77., 19OP, 13, 458 ; A.: i, 932.I? J l d . , 56, 18 ; A . , i, 5%Ibid., 54, 119; A., i, 231218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.but they were unable to decide whether it is a synthetic product,or a coagulated form of one of the fibrin proteoses.Lawroff 15 appears to have been more successful in formulatinggeneral views of the composition of these substances, although itis to be regretted that he has introduced confusion by the coiningof a new name for them. He obtained these precipitates (whichhe calls coaguloses) by the peptic digestion of proteins, as well asby their digestion in dilute mineral acids. He recognises twotypes of coagulose-yielding substances; the first are of the typeof proteoses, and the coaguloses which arise from them yield, onhydrolysis, both monoamino-acids and basic cleavage products.The second type of coagulose-yielding substances are polypeptides,and the coaguloses which arise from them yield, on hydrolysis,only monoamino-acids.The proteins which Lawroff first workedwith were caseinogen and haemoglobin, but subsequent work 16 withcrystallised egg-albumin showed that the same two types ofcoagulose-yielding substances could also be obtained from thisprotein after relatively short peptic digestion.These facts and theories are worthy of record, but I do notfancy the last word on plasteins or coaguloses has yet been written.Nucleic Acid.Nucleic acid has, in the past, been prepared from many differentsources, and differences have been noted in its percentage com-position and in its decomposition products.It has, therefore,been assumed that there are many varieties of nucleic acid, allresembling each other in containing phosphorus, in yielding purineand pyrimidine bases, and in containing a carbohydrate radicle,usuaIIy described as a pentose. The differences observed havebeen considered to be mainly due to the proportion in which thesevarious groups are combined together, and more especially to thenature of the purine and other bases contained within the mole-cule. It need hardly be said that if this view is correct, the com-plexity of the subject is enormous. But, as the years go by,and better methods for the separation and purification of nucleicacid are introduced, these difficulties are beginning to becleared up, and nucleic acids previously supposed to be differentare now to be regarded as identical.Schmiedeberg17 has beenable to give an empirical formula for the acid; and Levene andMandell8 have even advanced views as to its constitution, whichl5 Zeiitseh. physio?. Chem., 1907, 53, 1 ; A . , 1907, i, 995.l7 Arch. exp. Path. Pharm., 1907, 57, 309 : A . , i, 70.Ihid., 1908, 56, 343 ; A . , i, 844.Ber., 1908, 41, 1905 ; A . , i, 587PHYSIOLOGICAL CHEMISTRY. 219probably should be regarded more safely as provisional than final.Schmiedeberg, also, in his work has drawn attention to what heregards as a distinction between the hydrated and anhydrousforms of the acid, and to the power which the latter possesses ofgelatinising.This recognition of a gelatinous condition sometimespresented by nucleic acid and its salts is of importance, whetherthe explanation that the absence or presence of water in themolecule is the correct one or no€.A greater advance than this, however, was made a few years backby I. Bang. He prepared, from the nucleo-protein of the pancreas,a nucleic acid which is much simpler in composition than themajority of those previously investigated. It yields on decom-position three substances, namely, phosphoric acid, pentose, andonly one purine base, guanine. For this reason, he bestowed uponit the name of guanyPic acid. He also mentioned a fourthcleavage product, glycerol, but this has not been obtained by subse-quent workers, for instance, by Steude1,lg who otherwise confirmsBang’s results.The question was also taken up by v. Furth andJerusalem,20 who a t first denied the existence of guanylic acidaltogether. Bang21 pointed out how they had erred, and onre-investigating the matter they acknowledged their mistake,22and confirmed Bang’s statement, with the exception, again, thatglycerol was not found among the decomposition products ofguanylic acid.Since then, guanylic acid has been found in other organs, forinstance, in the liver, by Levene and Mande1.23Both liver and pancreas, however, contain, in addition toguanylic acid, what we may term ordinary nucleic acid, whichyields on cleavage other bases.These observers have, therefore, cleared up one previous sourceof error; there is no doubt that the older workers investigatedmixtures of nucIeic acid proper and guanylic acid, and thusobtained divergent analytical results. The discovery of guanylicacid a t first seemed to complicate the subject, but, really, it helpedto elucidate it.The next step was taken by Walter Jones,24 who, following upthe work of Schmiedeberg already referred to, has established theID Zeitsch.vhysiol. Chem., 1907, 53, 539 ; A . , i, 70.2o Beitr. chem. Physiol. Path., 1907, 10, 174; A!., 1907, i, 993.Ibid., 1907, 11, 76 ; A . , i, 70.22 Ibbid., 1908, 11, 146 ; A . , ii, 119.y5 Biochenz. Zeitsch., 1908, 10, 221 ; A., i, 587. They also describe a new methodGnanylic acid has also been for the separation of gnanine (ibid., 215 ; A., i, 586).discovered in the spleen, mammary gland, etc.24 J.Biol. Ckem., 1908, 5, 1 ; A., i, 744220 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.identity of at least three ordinary nucleic acids, namely, thosefrom the thymus, splqen, and pancreas. W-e need not follow himinto the interesting historical review of the curious “ comedy oferrors” which led to previous confusion. Most of these were dueto the different methods employed for isolating these substances,to the difficulties in estimating their cleavage products, to the non-recognition that certain bases are not primary cleavage productsbut arise by secondary reactions, and last, but not least, to admix-ture with guanylic acid.The special points worked out in deter-mining the identity of these acids were their specific rotationunder varying conditions, and the degree of viscosity of theirsodium salts. The so-called gelatinous sodium salt and the non-gelatinous salt are readily convertible one into another, andthis reversible action is believed to be a simple explanation, ifit occurs in zlizlo, of the physiological localisation and migration ofnucleic acid.He also states the following propositions, derived partly fromSchmiedeberg’s work and partly from his own, as being, a t anyrate, not far from correct:1. All “ ordinary nucleic acids ” (that is, nucleic as opposed toguanylic acid) yield the same two purine bases (guanine andadenine) and in the same proportion. Xanthine and hypoxanthine,when present, are due to the secondary action of de-amidisingferments.2.All yield the same pyrimidine base, cytosine.3. All yield lzevulic acid. This was first demonstrated byKossel, and points to the existence of a “ hexose ” carbohydrate.The previous statements about the presence of a pentose are, nodoubt, due to admixture with guanylic acid.4. There is, therefore, no insurmountable difficulty in acceptingthe hypothesis that the nucleic acids of different mammalian organsare identical substances. One must, however, be cautious a tpresent in applying this generalisation to all nucleic acids, for ithas been shown that those derived from plants and from fish eggsyield uracil, and that from the spermatozoa of fishes yieldsthymine, another pyrimidine base.Uracil obtained from mam-malian nucleic acid is derived secondarily from cytosine.5. The furfuraldehyde reaction stated to be given by nucleicacids is probably owing to admixture with guanylic acid, and dueto the guanine and pentose present.Tissue Metabolism.Metabolism was at one time only studied by what is called theThe total ingesta and egesta were measured balance-sheet methodPHYSIOLOGICAL CHEMIS'I'XY. 221and analysed, and by this means it was ascertained whether thebody was in equilibrium, or whether a deficit or the reverse wasoccurring in connesion with the main groups of body-constituents.Valuable as this method was, more important information still isobtainable by the investigation either of individual tissues ororgans, or in relation to the utilisation of one or other constituentof the food.It is this modern method of working at the subjectwhich has been successful in determining, not only the specialfunctions of each organ under varying conditions, but also ther8le played by the individual food-stuffs in their internal chemicalchanges.Many gaps exist in our knowledge still, but these are, year byyear, becoming less numerous, and from the large mass of workwhich has accumulated during the last twelve months, I am onlyable to select a, few papers which appear to be of exceptionalinterest.Respirution.-The work of Haldane and Priestley25 on theimportance of the chemical factor in breathing has been a greatstimulus to renewed work on the subject of respiration generally.Those who attend the meetings of the Physiological Societywill know the frequent discussions that occur there on the pointswhich still remain in dispute.I think, however, that Haldane'scontention, that variations in the tension of carbon dioxide in thepulmonary alveoli form the essential factor, has been very generallyconceded. The differences in the alveolar tension of this gas affectthe respiratory centre vici the blood-stream, and carbon dioxide isthe chemical stimulus par excellence which regulates the work ofthe respiratory centre in the brain. The points on which differenceof opinion still prevails are: (I) the part played by a diminutionof oxygen; (2) the relative importance of the nervous factor; and(3) whether fatigue products, such as lactic acid, may assist thecarbon dioxide in stimulating the respiratory centre.One notes an interesting piece of work relating in the main tothe second of these disputed problems by F.H. Scott.26 Fromthis work it appears that the principal respiratory nerves (thepneumo-gastrics) regulate the rate or rhythm of the xespiratorymovements, whilst the chemical factor specially regulates theamount of pulmonary ventilation, that is, the depth of the indi-vidual respiratory efforts; for when these nerves are divided, a risein the alveolar tension of carbon dioxide (or great diminution of25 See Ann. Xeport, 1905, 230.pci J. Phpsiol., 1908, 37, 301 ; A., ii, 865. A series of papers by Haldane a i dothers on the question of pulmonary ventilation has also just been published(J.Phpiol., 1908, 37, 355 ; A., 1909, ii, 66) too late for fuller iiotice here222 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the oxygen in the respired air) increases the depth, but not the rateof breathing. The vagi in reference to respiration are regardedin the same light as the sensory nerves of muscle; without thesenerves, muscular movements are excessive and even ataxic.Such researches have also cleared up the mechanism of Cheyne-Stokes breathing, that curious waxing and waning of the respira-tion which is seen slightly during normal sleep, and markedly inthe hibernating state of winter-sleeping animals, as well as inmany pathological states in man (Pembrey 27).The condition common to all these states is a decreased excita-bility of the nervous system, and especially of the respiratorycentre.The man or the animal does not breathe for a certainperiod, a.nd during this apnceic stage, carbon dioxide accumulatesuntil its amount is sufficient t o stimulate the depressed cells of therespiratory centre to execute shallow and inefficient efforts atbreathing; but as the accumulation of the gas goes on, the respira-tions become more and more forcible, and culminate in forced ordypneic breathing; this sweeps out the carbon dioxide, and theconvulsive movements become quieter, the breathing gets shallower,and, finally, it once more ceases for a period, until the same seriesof events is again repeated.The Part Played b y Leucocytes in Protein Absorption.-Theentrance 0.f oxygen by the lungs is, of course, only the start ofthe true respiratory process which occurs in the tissues.Theentrance of protein by the alimentary tract is, also, only theinitial stage of protein metabolism. In last year’s Report I dealtwith this question, and so it will not be necessary to repeat myself.Dr. Pavy, in some recent lectures published in the Lancet,2* how-ever, dissents from the view now gaining credence among physio-logists, that the proteins are absorbed as amino-acids. He holdsthe older view, that the intestinal wall is the seat of proteinsynthesis, and, further, that the lymphocytes play an importantpart as protein-carriers. This last hypothesis has received supportfrom the work of Cramer and Pringle,29 who emphasise, as Pavydoes, the increase in these cells which occurs whether the proteinbe introduced in the usual way or parenterally.The blood ofdigesting animals shows a small but distinct increase of (‘ residualnitrogen ” over that of fasting animals, and the major part of thisis in the corpuscular elements. It is impossible to deny that theincrease in lymphocytes during absorption has some significance,but their total bulk is so small that it is difficult to believe that37 J. Patla. Bact., 1908, 12, 258 ; A . , ii, 204.29 November am1 December, 1908.zy J. P h y s d . , 1908, 37, 146 ; A., ii, 709PHYSIOLOGICAL CHEMISTRY. 223they carry the whole burden, and, therefore, Cramer’s conclusionthat these cells “ partly, a t any rate,” may perform a share of thework, is probably all that it is safe to affirm at present. It will,however, be noticed that such increase in nitrogen as can be deter-mined is in ‘‘ residual,” not in “ coagulable nitrogen.” Cramer,therefore, does not go as far as Pavy, for protein synthesis, accord-ing to him, does not occur at the seat of absorption, or even afteringestion by the colourless corpuscles.Respiratory Metabolism of the Sphal Cord.-The gaseous meta-bolism of nervous tissues is, perhaps, the most difficult of allsubjects to investigate, but by the use of Thunberg’s micro-respiro-meter,30 it has been shown that even peripheral nerves participate,to some extent, in respiratory interchanges.We should anti-cipate, OK a priori grounds, that the more vascular central nervousmaterial would be more active in this direction; we, a t any rate,know that if the brain is deprived even momentarily of its duesupply of fresh oxygen, unconsciousness or fainting is the result.MOSSO, also, some years ago stated that the temperature of thebrain is a high one, and during the last year Winterstein31 hassubjected the isolated fresh spinal cord of the frog to quantitativeexperiment; he found that, on stimulation, it has a high respiratoryexchange; per unit of weight this is two or three times greaterthan that of the body as a whole. Curiously enough, stimulationby the administration of strychnine was not found to have anyeffect.Rate of Conduction in serve.-An indirect means of approach-ing the question whether any given phenomenon is chemical orphysical is the method of determining the temperature-coefficientof its velocity.Arrhenius showed that the rapidity of a chemicalreaction is a t least doubled by a rise of loo in temperature,whereas a physical reaction is not accelerated in nearly so greata proportion. Synder 32 has used this method in relation to anumber of physiological phenomena, and although his data are, inmany cases, insufficient to draw conclusions from them, he never-theless showed that, in cases where it is known that metabolismdoes occur, the coefficients observed are those of chemical reactions.The method, therefore, appears to be one which possibly maysettle the vexed question whether the propagation of the nervousimpulse is chemical or physical.Maxwell 33 made experiments onthe pedal nerve of a giant slug; he selected this, first, because it:30 A m . &:port, 1905, 231.:I1 Z c n t ~ . Pl~ysLoZ., 19OS, 21, 869 ; A, ii, 509.Ante?.. J. Physiol., 19OS, 22, 309 ; A., ii, 768.‘j3 J. Bid. C h w . , 1907, 3, 359 ; A., 1907, ii, 977..>,2% ANNUAL REPORTS ON THE PROGRESS OF CNENISTRY.is a sufficiently long nerve, and secondly, because the normal rateof conduction is sufficiently slow for purposes of measurement.From his figures he concludes that the nerve impulse is a chemicalphenomenon, although he doubts whether it is an oxidationprocess. These experiments have been repeated by Woolley34 onamphibian nerve, and although he obtains the same figure asMaxwell (1.78 to 1-79), he is, unfortunately, not so clear as toits interpretation, for he doubts whether the high figure is anecessary proof of it chemical as opposed to a physical process.The conduction rate in amphibian muscle has about the samecoefficient (1.79 to 2-01>.It is pretty certain that muscular con-duction has an underlying chemical basis, and probably theconduction process is similar in both tissues. The coefficient forthe latent period of muscle is distinctly higher (3.26 to 3*3), andthis result strengthens a supposition previously advanced on othergrounds that conduction in muscle is a propagation, not of thecontractile change, but of an independent disturbance which elicitsthe contractile change a t each point on its passage.Glycogen.-This subject is one of perennial interest in relationti0 metabolism, and some observations on rabbits made by Lochheadand Cramer35 furnish a useful contribution to the chemistry ofgrowth.In the fetal condition, the greater part of the placentalglycogen was found in the maternal portion of the placenta; thisdiminished from the eighteenth day of fatal life onwards, whereasthat in the fatal liver increased. A distinct parallelism wasfound between the growth of the fetus and the amount of glycogenwhich it contains. In the earlier stages of intra-uterine life,the fatal liver does not possess the power of storing glycogen;this power is not acquired until the last week of gestation.Duringthe earlier period, the placenta fulfils the hepatic function so faras glycogen is concerned. Investigations on the effect of diet andphloridzin appear to show that the glycogen metabolism of theplacenta and fetus is independent of that of the mother.Pfluger3G seems to have published only one paper on glycogenthis year; he finds that the administration of kvulose leads tothe formation of glycogen in the liver, but the glycogen formed isnot laxorotatory; the liver cells have, therefore, the power of trans-forming the sugar given into dextrose, and it is this from whichthe glycogen is formed.His colleague a t Bonn, I(. Grube,37 has continued his interesting3‘ cJ. Physiol., 1908, 37, 112, 122 ; A., ii, 711.22 Proc.Eoy. ,SIN., 1908, 80, K, 263 ; A . , ii? 710.PJiiger’s Archiu, 1908, 121, 559 ; A., ii, 307.37 LM., 636 ; A., ii, 307PHYSIOLOGICAL CHEMISTRY. 225experiments on the perfusion of the tortoise’s liver, and, in answerto the question what is the smallest molecule from which the livercan make glycogen, finds that by perfusing that organ with aweak formaldehyde (O.Ol-O*OZ per cent.) solution, the liver is ableto make glycogen from it.The R61e of Sagar in Muscular Activity.-In confirmation ofthe view, now so generally held, on the importance of sugar as thesource of muscular energy, Locke and Rosenheim’s 38 results on theisolated mammalian heart must be noted. They describe aningenious new perfusion method 39 by which a solution of dextrosein oxygenated Ringer’s solution can be repeatedly circulatedthrough an excised rabbit’s heart.Five to ten centigrams of thesugar disappear in from eight to nine hours. This is not due tominor metabolic or fermentative by-processes, but is associatedwith the main chemical change that underlies cardiac activity. Ifthe activity of the heart is lessened by the omission of the calcium,or still more by the omission of both calcium and potassium fromthe circulating fluid, the amount of sugar used up is lessened.The amount of carbon dioxide formed runs parallel with the dis-appearance of sugar. No evidence was found of the formationof disaccharide or of lactic acid, or of the storage of glycogen inthe heart. Nitrogenous waste was not fully investigated, but thetotal is extremely small.The last aspect of the subject has been taken up incidentally ina piece of work just published by Howell and Duke.*O Theseauthors had previously stated that an output of potassium fromthe heart’s substance occurs during vagus inhibition, and sug-gested that the increase in cardiac activity which follows stimula-tion of its accelerator nerves may be due to an output of calcium.Using the Locke-Rosenheim method of perfusion just referred to,their findings, however, were negative; neither the calcium nor thepotassium in the circulating fluid showed any variation in amountafter a perfusion lasting for hours, nor after long-continued excita-tion of the heart through its accelerator nerves.I n relation to nitrogenous metabolism, they found no output ofhypoxanthine, such as Burian has described in the case of skeletalmuscle.This may be a fundamental distinction between the twoforms of muscular tissue, or it may be due to the presence ofdextrose in the circulating fluid used by Howell and Duke,which was absent in Burian’s experiments. The heart, however,3* J. Physiol., 1907, 36, 205 ; A . , ii, 120.39 Brodie and Miss Cullis have also described a new apparatus for the heart-perfusion (ibid., 1908, 37, 337 ; A., ii, 865).1 O Amer. J. Physiol., 1908, 23, 174; A,, 1909, ii, 72.REP.-VOL. V. 226 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.gives off creatinine (or creatine) to the circulating fluid, and itwill be interesting to determine how far this elimination is asso-ciated with functional activity.Creatine and Creatinine.Creatine is absent from normal urine and creatinine is alwayspresent.I t is, in fact, next to urea, the most abundant nitrogenoussubstance found there. Amid all the inconstancies of urinary com-position, it appears to be the substance which is most constant inamount, diet and exercise having no effect on it. The old idea that;the bulk of the urinary creatinine is derived from the creatine offlesh food has been entirely abandoned, and Folin’s view that it is ameasure of endogenous nitrogenous katabolism has steadily gainedground, The close chemical relationships of the two substances inquestion led physiologists to the erroneous conclusion that creatine isthe source of the excreted creatinine.The discovery of the mistakehas led some to the equally hasty conclusion that the two materialshave no physiological connexion a t all. A relationship does existbetween them in. vivo, but it is a different one from that previouslysupposed to exist. During the past year, the papers relating tothis subject have been numerous, and although differences of opinionon points of detail are noticeable, the general trend of most ofthe results is the same.Taking Mellanby 41 first, he took as his starting-point an investi-gation of the contradictory data relating to the proportion ofcreatine and creatinine in muscle. Monari’s authority is usuallyquoted for the text-book statement that the latter increases atthe expense of the former when muscle becomes active.Mellanbyhas shown that this is not the case. Monari’s technique affordsan opportunity for the change to occur, and his precipitates wereimpure. Creatinine is never present in muscle a t all, even afterprolonged muscular work ; the original amount of creatine remainsunaltered by work, and even (in frog’s muscle) after survival forthree days.42I n addition to this, aseptic or antiseptic autolysis causes nochange in either creatine or creatinine. When, however, the musclebecomes septic, all the creatine disappears. The statements ofGottlieb and Stangassinger 43 regarding the tissue enzymes theyterm creabase and creatinase were in no respect confirmed.4441 J. Physiol., 1908, 36, 447 ; A., ii, 308.42 Cathcart and Graham Brown, however, discovered a slight increase of creatininein frog’s muscles after stimulation ; hut if the circulation is intact there is a decrease(Proc.physiol. SOC., 1908, xiv--xv ; J. Physiol., 37 ; A . , ii, 516).43 Ann. Report, 1907, 239.44 Gottlieb and Stangassinger have published a seooncl paper on these ferments PHYSIOLOGICAL CHEMISTRY. 227Invertebrate muscle contains no creatine, and Mellanby selectedthe developing bird in which to study the biochemical history ofcreatine. It is absent from the musculature of the chick up to thetwelfth day of incubation; after this date, the liver and themuscular creatine develop pari passu. After hatching, the liverstill continues to grow rapidly, the creatine percentage in themuscles increases also, although the development of the size ofthe muscles occurs very slowly.This led Mellanby to the con-clusion that the muscular creatine has its origin in the liver. Theliver is thus continuously forming creatinine from substancescarried to it by the blood from other organs; in the developingmuscles this is changed to creatine, and then, when the muscle issaturated with creatine, excess of creatinine is excreted by thekidneys. His view is, therefore, an absolute reversal of thosepreviously held; the muscles do not change creatine into creatinine,but creatinine into creatine. I f creatine (an innocuous neutralsubstance) was converted by the muscles into creatinine (a stronglybasic substance), it would really be contrary to all that is knownof the chemical changes which occur in the body.This view is upheld by experiments in which creatine andcreatinine were added to the food; feeding with the latter substanceleaves the muscles still free from that material. Feeding withcreatine has also no effect after the muscles have reached a certainpoint of saturation.The small amount of creatinine excreted in diseases of the liveralso supports the view that that organ is responsible for creatinineformation.The excretion of creatine in cancer of the liver isexplained by supposing that the muscle cells break down, and thatcreatine is liberated without conversion into creatinine beforeexcretion takes place.Verploegh and van Hoogenhuyze 45 have published an extensiveseries of observations on creatinine excretion ; they confirm Folin’sviews in the main, and also agree with Mellanby concerning theimportance of the‘liver in its metabolic cycle.Their reference toMellanby’s views, however, appears to contain a misunderstanding,for they allude to the conversion of creatinine into creatine by theliver, which was not Mellanby’s point a t all. This change theythey attribute the destruction of creatiniue and the consequent appearance of creatinewhich liver extracts accomplish t o the action of creatinase, and the subsequent dc-struction of creatine to creatasc (Zeitsc’c. physiol. Chcm., 1908, 55, 295, 322;A., ii, 515). Their statements regarding the non-participation of putrefaction inthis ferment action are confirmed by Rothmnnn (ibid., 1908, 57, 131 ; A ., ii, 967).That the transformation of creatine into creatinine in the liver is the work ofsoluble ferments is also confirmed by van Hoogenhuyze and Verploegh (ibid., 161 ;A., ii, 971). 46 Loe. cit.Q 228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRT.attribute to the creatinase of Gottlieb and Stangassinger,46 and inconditions where hepatic activity is lowered (cancer of the liver,certain fevers, and hunger), the appearance of creatine in the urineis explained by its non-conversion into creatinine.Mellanby’s views will, of course, have to be subjected to the usualtests of criticism and renewed research, and, until they have stoodthis, cannot be accepted as proved. They nevertheless provide astimulus to fresh work, and their novelty, and the fact that theydo explain some of our previous difficulties, render them attractive.He entirelydissents from Mellanby’s theory that creatinine is formed in theliver at all; neither does he agree with Folin that its amount isan index of endogenous protein metabolism.He, however, confirmsprevious statements regarding the constancy of its amount, and heplaces the figure at from 7 to 11 milligrams of creatinine nitrogenexcreted per diem per kilo. of body-weight. The excretion isconstant, not only from day to day, but from hour to hour; it isnot influenced by the volume of the urine, nor by the total nitrogenexcreted. The creatinine coefficient is parallel to the muscularefficiency of the individual, and its source is some special processof muscular metabolism.But in acute fevers, he states that itsexcretion is increased, and admits that here it is not parallel tomuscular efficiency. Creatine is absent from normal urine, but itmay be excreted in acute fevers, in women during involution ofthe uterus, and in certain other conditions in which there is arapid loss of muscle-protein.Shaffer is not the first who has pointed out a parallelism betweencreatinine excretion and muscular development.48 The smallamount in infants’ urine corresponds with the smaller amount ofmuscular development in the child. The amount of creatinine ininfants’ urine is so small that some previous observers, using theold zinc chloride method, missed it altogether.Funaro4g hasalways found it present, and its amount constant, in spite ofvariations in the food.Another lengthy paper on creatinine metabolism has recentlyappeared by G. Lefmann.50 The following are its principal con-clusions: The excretion of creatine and creatinine is prettyconstant in well-nourished animals. I f either substance is addedto the food, it is excreted unchanged. I f creatine is given by themouth, or parenterally, it is never changed into creatinine, andShaffer,47 for instance, has independent opinions.46 See footnote 44.47 Ainer. J. Physiol., 1908, 23, 1 ; A., ii, 971.49 Biochcm. Zeitsch., 1908, 10, 467 ; s4., ii, 716.5o Zeitsch. physiol. Chew., 1908, 57, 476 ; A , , ii, 1050.See Spriggs, also Amberg and Morrill, Ann.Report, 1907, 238PHYSIOLOGICAL CHEMISTRY. 229in inanition it is almost completely excreted as such. Disease ofthe liver or increased protein katabolism produces, first an increase,then a decrease in creatinine excretion, and when it is lessened, theamount of creatine excreted rises. The liver is the probable seatof creatinine formation. I f nephritis is induced by chromates,nearly all the creatinine is changed into creatine, probably by thealteration in the reaction of the urine.I have been content merely to enumerate Lefmann’s conclusionswithout comment; some agree with, some differ from, those enun-ciated by others, and the last one opens up a new possibility.None of the papers written (except that of Mellanby) haspresented a clear and consecutive view of the history ofcreatinine, and although some of his views may have to be modifiedin the future, there is a general consensus of opinion now that theliver plays an important share on the constructive side of its meta-bolism.The Lipoids.61The term lipoid is one of recent origin; it appears to have beenfirst employed by Overton in 1901 for a group of substances con-tained in the protoplasm of all cells, especially in their outer layeror cell-membrane.Overton pointed out, in his work on narcotics,that materials which act as anzesthetics (such as ether and chloro-form) are capable of obtaining an entry into the cell, because theyare soluble in the lipoids of the cell-membrane. Whether this isa correct explanation for the narcotic properties of all drugs ornot, the fact which is undoubted is the solubility of many anaes-thetics in lipoid substances, and the solubility of the lipoids inthese anzesthetic reagents.I n their solubility in such reagents asether, chkroform, alcohol, etc., the lipoids resemble the fats andfatty acids; hence their name.The interest recently bestowed on the lipoids is due, not onlyto their chemical properties, but also to their biological importance.Although present in smaller amount than proteins, they appear tobe essential constituents of protoplasm, and the labile character oftheir molecules, in many cases, is a property they share in commonwith the proteins. There seems to be a good deal of truth in theopinion expressed by Bang that the importance of proteins as“ carriers of life ” (Triiger des Lebens).has been over-estimated,whilst that of the lipoids has been neglected. The lipoids are con-tained in special abundance in that tissue, which, above all others,51 In the preparation of this section, I have been much helped by two courses oflectures delivcred a t King’s College by 0. Rosenheim, who has devoted much of histime to a study of the lipoids. The first of these lecture courses has been publishedin B condensed form in Science Progress, 1908, April and July230 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.manifests what we still may call “vital properties,” namely, thenervous tissues, and it is in the brain and similar structures wherethey have been most studied. Thudichum’s great work on brainchemistry, published in 1874, was very much neglected, probablybecause of the polemical nature of most of his writings. It was,however, valuable pioneer work, and the research of the last fewyears has done much to demonstrate its correctness.Many state-ments, attributed in text-books to more recent investigators, aremerely confirmations of what Thudichum discovered. Confusionhas been introduced into a subject already sufficiently complex bythe coining of many names for the same substances. I shallendeavour here to retain, as far as possible, Thudichum’s originalnomenclature, and although Thudichum did not employ the termlipoid, his classification of them is still the one which is adopted.The lipoids are practically all contained mixed with fat, fattyacids, and lipochromes in the ether-alcohol extract of tissues andorgans.Their separation from the fats, and from each other, isusually difficult, involving troublesome processes of fractional preci-pitation by various solvents, into a description of which I do notintend to enter. Selective extraction, however, is sometimespossible, and gives much better results; for instance, if the residueof the alcohol-ether extract is treated with cold acetone, cholesterolonly passes into solution; if extraction with hot acetone is thenperformed, the mixture known as protagon is extracted; andprotagon may be separated into its constituents by pyridine andso forth.The lipoids may be classified in the following way:1.Those which are free from both nitrogen and phosphorus.The most important member of this group is cholesterol.2. Those which are free from phosphorus, but contain nitrogen.These yield galactose on cleavage, and were termed cerebro-galactosides or cerebrosides (for short) by Thudichum. Phrenosinand kerasin are the best known members of this group.3. Those which contain both phosphorus and nitrogen, andwhich are best known by Thudichum’s name of phosphatides.They are grouped by Erlandsen52 according to the proportion ofnitrogen and phosphorus in their molecules as follows :.a. Monoamino-monophosphatides, N : P = 1 : 1, for instance,lecithin and kephalin.6 . Diamino-monophosphatides, N : P= 2 : 1, for instance,sphingo-myelin and amido-my elin.c. Monoamino-diphosphatides, N : P = 1 : 2, for instance, cuorinof heart muscle.52 Ann.Beport, 1907, 251PHYSIOLOGICAL CHEMISTRY. 231d. Diamino-diphosphatides, N : P=2: 2. One of these wasseparated from brain by Thudichum, but has not since beenexamined.e. Triamino-monophosphatides, N : P = 3 : 1. One of these(neottin) is present in egg-yolk. It differs from other phosphatidesin yielding no unsaturated fatty acids.This system of classification is obviously capable of extension,as phosphatides are discovered in which the N : P ratio is differentfrom those enumerated above.We may now take these various substances in order, mentioningin relation to each the new facts which have been made outconcerning them during t'he last year.Cholesterol.-This is found in small quantities in all forms ofprotoplasm; until within the last month it was stated to be absent,however, in heart muscle.J. A. Gardner 52 has reinvestiga ted thispoint, and finds it present there in about the same proportion asin other forms of muscular tissue. It is a specially abundantconstituent of nervous . tissues, particularly in the white sheathof nerve fibres. It occurs there in the free state, and is readilyextracted by cold acetone.Until a few years ago all that was known of its chemistry wasthat it has the formula C,,H,,O (or C,,H,,O), and that it is anunsaturated monatomic alcohol.Recent research has shown that it belongs to the terpene family,a group of substances previously known only in plants, and thefollowing formula has been tentatively put forward to indicateit's constitution :C*3 /\/\ ,'\"'\G3H7.1 1 1 1 1 J \/\/-\/\/\=/ UH3that is, five reduced benzene rings are linked together, and it isimportant to note that in order that cholesterol may exercise itsphysiological action, the double linking shown as well as thehydroxyl group must be intact."Cholesterol compounds also exhibit a physical phenomenon53 Communication made to the Physiological Society, December, 1908 : not yetpublished.C. Dorde (Proc. physiol. Soc., 1908, lviii-Iix ; J. Physiol., 37 ; A., ii,769) has also found cholesterol in ccelenterate animals.54 The function of cholesterol in enabling the body cells to withstand the actionof toxins was indicated in last year's Report (pp.252-253). A very useful-summaryof the chemistry, distribution, and biological importance of the cholesterols andphytosterols (vegetable cholesterols), with bibliographical references, is given in anarticle by W. Glikin (Biochem. Zentr., 1908, 7, 289, 351)232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.recently studied by Lehmann, namely, the formation of liquidcrystals, which is also given by several other lipoids. It is notwithin the province of this article to enter into the many interest-ing data which the study of liquid crystals has brought out; itwill be sufficient for my present purpose to point out two onlyof these, both having a biological bearing.The first of these relates to what Virchow termed I f myelin-forms’’ in 1855.If brain substance is mixed with water, threadsare observed shooting out and twisting into fantastic shapes; thesehave a superficial resemblance to nerve fibres, and the movementsoften simulate protoplasmic or amceboid movements. The term“ myelin-forms ” applied to them is somewhat unfortunate, for theword myelin has been applied to different chemical substances, and ithas now no precise chemical meaning ; it is most frequently employedsynonymously with the white sheath of nerve fibres, and no doubtthe earlier observers thought that myelin-forms were associatedin some way with the behaviour of the lecithin-like substances whichare present in white matter. Myelin-forms can also be obtainedwith cholesterol mixtures, and some have gone so far as to say,“ without cholesterol no myelin-forms.” This is not correct, forother lipoids and also certain oleates show the same phenomenon.Various theories have been advanced to account for myelin-forms,and some of these imply that in the investigation of this remarkableappearance will be found the explanation of living movement. Ithas now, however, been conclusively shown that myelin-forms aremerely distorted liquid crystals, due to the presence of cholesteroland other lipoids.The second biological outcome of a study of liquid crystalsrelates to the fat globules seen in the cortex of the suprarenal body,during cell-proliferation in cancer, and in the liver and other organsduring so-called fatty degeneration.These are not composed offat, for the polarisation microscope shows them to be anisotropic,and further investigation has shown them to be lipoids in the fluidcrystalline condition.55 There is no .doubt that cholesterol formsa very considerable constituent of these globules, but it was foundthat pure cholesterol, or cholesterol ethers, do not exhibit thephenomenon, nor do they give the characteristic colour reactionswhich are given by the white matter of nerve fibres. Whatappears to be necessary is a mixture of cholesterol a.nd fatty acid,and it has been suggested that in such mixtures the acid is incor-porated as “ acid of crystallisation,” analogous to the “ water of55 C. P. White, J. Path. Buct., 1908, 13, 3, 11 ; J. L. Sniith and others ibid.14 ; A., ii, 966, 968, 972 ; T.Panzer, Zeitsch. physio2. Chem., 1907, 54, 239 ; A . ,ii,122PHYSIOLOGICAL CHEMISTRY. 233crystallisation ” in many other crystals. It is quite probable thatthe ethers of cholesterol described by Hurthle as present in theblood are not true esters, but similar mixtures of cholesterol andfatty acid. This is rendered all the more probable if the view thatcholesterol is a protective agent against toxins is upheld; for wehave already seen that, in order that it may exercise this function,the double linking and the hydroxyl group must be intact, whichwould not be the case in an ether. We have already noted thatcholesterol occurs free in the brain, and Salkowski has shown thatthe same is true for the cholesterol of the bile.56The globules referred to, however, do not consist altogether ofcholesterol mixtures.Rosenheim and Miss Tebb have preparedfrom the suprarenal cortex a substance analogous to the sphingo-myelin of brain which shows the same appearance^.^^These investigations throw light on the possible function of thecortex of the snprarenal gland; it may be that the cells thereare engaged in the secretion of cholesterol and other lipoids, andthat this has some connexion with the regulation of growth anddevelopment; from his observations on the liquid crystals oftumours, C. P. White 58 suggests that cholesterol is associated ratherwith cell-proliferation than cell-degeneration ; and Mendel,59 inhis studies on growth in embryos, arrives a t much the same con-clusions; in the chick embryo, cholesterol disappears like the otherlipoids of the yolk, being sources of energy in growth.Before passing from cholesterol to the consideration of otherlipoids, there is one more piece of work which deserves a passingreference; I refer to that by C.Dor6e and J. A. Gardner.60 onthe excretion of cholesterol. A t an earlier date, when cholesterolwas supposed to be a mere waste material excreted by the bile,Austin Flint found in the faeces a substance which he namedstercorin, and which, as he rightly surmised, is a cholesterolderivative. This material, which was re-named coprost’erol byBondzynski, is a saturated alcohol with the formula C2,H4*0; itspresence in the faxes is, however, not constant; it was found byDor6e and Gardner in dogs’ fxces after feeding on raw brain,but in dogs fed on cooked vegetables or meat, cholesterol is presentas such.Whether this cholesterol originates from the food orfrom the bile is very uncertain, for in horses it is entirely absent;if these animals excrete cholesterol in their bile, it must thereforeeither be destroyed or re-absorbed. The substance called hippo-.56 Zeitsch. phyiol. Chem., 1908, 57, 521 ; A., ii, 1055.57 J. Physio?., 1908, 37, 348 ; A . , ii, 879.O9 Amcr. J. Physiol., 1908, 21, 77 ; A . , ii, 208.J. Path. Bact., 1908, 13, 3 ; A . , ii, 972.Proc. Xoy. Soc., 1908, 80, B, 212, 227 ; A , , ii, 514234 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.coprosterol in horses’ faxes (which was formerly supposed to beanalogous to coprosterol of human or dogs’ faeces, and considered tobe derived from the bile by bacterial reduction in the intestine) isonly present after feeding on grass, and is undoubtedly a phytosterolor cholesterol of vegetable origin.Following the usual custom oflabelling phytosterols by their plants of origin, Dor6e and Gardnerpropose to term it chortosterol to indicate that it is derived fromgrass; its formula is C27H540, and it gives none of the usual colourreactions of cholesterol.The only paper I shall allude to on the protective action ofcholesterol confirms those I referred to in last year’s Report. Itis by Minz,G1 and deals with cobra and viper venoms. Cobravenom, as is well known, contains two toxins, one which dissolvesblood-corpuscles (hzmolysin), and the other which attacks nerve-cells (neurotoxin); the hzmolytic action of the venom is aloneinhibited by cholesterol; the latter is believed to remove fromsolution the lecithide, the prolecithide, and to a less degree lecithinitself.It will be seen from this that the author accepts thestatements of Kyes and others concerning the part lecithin andlecithides play in the anchoring of toxins on to cells, statementswhich we shall presently see have been subjected to criticism.The action of the neurotoxin is not influenced by cholesterol.Viper poison also contains two toxins, a hEmolysin, and a poisonwhich leads to the occurrence of hzemorrhages (hcemorrhagin).The latter is not inhibited by cholesterol, the former is.Thehzemorrhagin, however, is destroyed by hydrochloric acid, thehzemolysin not.The Cere6rosides.-A warm alcoholic extract of brain depositsa white precipitate on cooling; if the cholesterol contained in thisdeposit is extracted with ether, the residue may still be calledprotagon, not as implying that it is a definite chemical individual,but as a convenient expression, employed in much the same wayas the term peptone is still used for a mixture of protein cleavageproducts. Protagon was originally called c&rQbrote by Couerbe ;the word protagon we owe to Liebreich, who regarded it not onlyas a definite compound, but the mother substance of the otherphosphorised and non-phosphorised constituents of nervous tissue.It has now been conclusively proved in confirmation of whatThudichum stated in 1874, that protagon is a mixture of phos-phorised and non-phosphorised substances, in such propor-tions that it usually contains about 1 per cent.of phosphorus.6261 Bi0che.m. Zeitsch,., 1908, 9, 357 ; A . , ii, 415.62 The attempted resuscitation of protagon by Cramer alluded to in last year’sReport (pp. 247-249) has led to further writing of a somewhat polemical naturPHYSIOLOGICAL CHEMISTRY. 235By treatment with appropriate reagents and recrystallisation,protagon can be separated into its constituents; the best methodis to dissolve ‘‘ protagon ” in pyridine; on allowing this solutionto stand, the constituent rich in phosphorus separates out in theform of anisotropic globules (fluid sphzro-crystals), and thosewhich are free from phosphorus and comprise about 70 per cent.of the original protagon reniain in solution.The phosphorus-richconstituent is a phosphatide sphingo-myelin which we shall dealwith under its appropriate heading, and the phosphorus-free con-stituents are the cerebrosides. Although these have received manynames, the total number of known cerebrosides is two. These arenamed, to employ Thudichum’s original terminology, phrenosinand kerasin. The former is a crystalline product, the latter ofwaxy consistency.Phrenosin yields on cleavage three substances : -(1) A reducing sugar, galactose.(2) A base termed sphingosine, about which little or nothingchemically is yet known.(3) A fatty’acid, termed neuro-stearic acid by Thudichum; ithas a higher molecular weight than stearic acid, but has not beenyet definitely identified.Kerasin also yields galactose and sphingosine, but its third con-stituent, the fatty acid, is not neuro-stearic, but another acid,which has also not been identified as yet.The only noteworthy piece of work during the last year relatingt o these substances is that by K.Takaki63 in connexion withphrenosin, which he speaks of under Thierfelder’s name as cerebron.He finds that it is one of the substances in the brain which uniteswith tetanus toxin; it is apSparently not the only brain constituentwhich acts in this way, for more of the tetanus toxin disappearswhen mixed with brain substance than can be accounted for bythat which combines with the phrenosin.It is apparently theneuro-stearic acid constituent of phrenosin which is responsible forthis action.The Phosphatides.We are now free to pass to a consideration of the phosphatides,and will deal with them under the headings already given in ourclassification a few pages back. I n the first group, the mono-(see Wilsoii and Cramer, Quart. J. exp. PhysioZ., 1908, 1, 97 ; A., i, 234 ; Rosenheimand Bliss Tebb, ibid., 297 ; also J. Physiol., 1908, 37, 341, 348.; A., ii, 879). Theadditional facts brought out by the last-named observers will, it is to be hoped, besuccessful in ‘ ‘ laying ” protagon beyond hope of further resurrection.63 Beitr. chern. Physiol. Path., 1908, 11, 288 ; A ., ii, 521236 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.amino-monophosphatides, we have to deal with lecithin andkephalin.Lecithin.-Although the empirical, and probably also the con-stitutional, formula of this substance are fairly well known, suchknowledge is largely based on conjecture, for lecithin is a mostlabile material, as recent work on its cadmium and other saltshas shown.64 We know, however, that on decomposition it yieldsthe base choline, glycerophosphoric acid, and two fatty acidradicles. The nature of the fatty acids may vary, but in thelecithins found in the body, oleic acid is always one; the fattyacid radicles are linked to glycerol as they are in ordinary fats.The place of the third fatty acid radicle of an ordinary fat istaken by the phosphoric acid radicle, and this in its turn is inethereal combination with choline.Lecithin forms compounds with many substances, with metals,with alkaloids, with proteins (lecitho-proteins), and with carbo-hydrates. Possibly many of these are adsorption rather than truecompounds.The main interest of lecithin to the biologist is the part it issupposed to play as an amboceptor in linking poisonous proteinsto cell protoplasm, as was first pointed out by Kyes in his work onthe hzmolysin of cobra venom.65 I accepted this view with con-siderable reserve in my Report last year, and my cautiousness hasbeen justified by much of the work that has been issued duringthe current twelve months.I f teleological argument is permissible,it is difficult to see the advantage in the struggle for existencewhich lecithin would confer upon living organisms.It may, ofcourse, be that the assimilation of a food protein is on all fourswith that of a toxic protein, and the nutritive value of lecithin,which has been asserted so frequently, may possibly rest upon thisamong other factors; but even this falls to the ground if theassimilation of protein matter is usually accomplished, not by theincorporation of ready-made protein, but by that of its simple(amino-acid) cleavage products.I. Bang, who stands in the front rank of modern investigators,in his attempts to repeat the work of Kyes, has entirely failed tosubstantiate his main premises.66 He finds that the existence ofcobra lecithide is unproved, and that Kyes’s lecithides are mixturesof fats, soaps, and decomposition products of lecithin.Lecithinitself is wholly inactive as an activator; the same is true forcuorin. He found the kephalin fraction to possess some activityG4 W. HeuEner, Arch. exp. Path. Phnrm., 1908, 59, 420 ; A . , 1909, i, 5 .65 Ann. Xeport, 1907, 251.GG Biochem. Zeitsch., 1908, 11, 520 ; A . , ii, 721YHYSIOLOG ICAL CHEMISTRY. 237in this direction, but there was no guarantee even here that hewas dealing with a pure substance, and he found that Kossel’sprotagon (which he speaks of incorrectly as consisting largely oflrephalin) is also inactive. What does seem to be certain is tha’cthe hzemolysis produced by snake venom depends on the existenceof a lipolytic enzyme; this view is accentuated by the careful workof v.Dungern and Coca.67 It is the scission products liberatedby such an enzyme which act hzmolytically, especially de-oleo-lecithin (th?t is, lecithin minus its oleic acid) and oleic acid itself.These observers agree with Bang that compounds of lecithin andcobra toxin do not exist, and that Kyes’s preparations are mixturesof numerous substances. Cobra poison contains no amboceptor,and the hemolysis produced by a combination of cobra poison andthe complement of serum -is due to a complex serum hEmolysinwhich acts only in certain circumstances, of which the mostimportant is that the blood-corpuscles must have taken up acertain quantity of lipase.I n this connexion it should also be noted that the Wassermannreaction of the cerebro-spinal fluid so much employed to-day forthe detection of syphilis is also due to lipolytic activity, probablyproduced by the agency of the syphilis parasite (spirochzte).Two papers deal with the estimation of lecithin in animaltissues; one of these is by W.GlikinY6* who finds a specially highpercentage of this substance in the bone-marrow of new-bornanimals, especially in those which are born in an immature con-dition. The other is by J. NerkingYG9 who has estimated the totalyield in the bodies of certain animals, as well as in their individualorgans. I n the rabbit the quantity works out as 0.4 per cent.of the body-weight. I n the hedgehog the yield is especially high,particularly in bone-marrow and suprarenal.Nerking somewhatinconsequently concludes that this may explain the comparativeimmunity the hedgehog possesses against sna ke-bite ; for if lecithinfavours the safe anchorage of snake poison, it can hardly beexpected to act also as a protection against the venom. Thehedgehog, if immune against snakes, much more probably owesits freedom from attack to its protective coating of spines.ChoZine.-This basic product of lecithin cleavage possesses a gooddeal of physiological interest ; its presence in the circulating fluidsis an exact chemical proof of the breakdown of lecithin, and soof nervous material. The methods of detecting this substanceI need not go into again, but will refer readers interested in the67 Biochorn.Zeitseh., 1908, 12, 407 ; A., ii, 866.63 lbid., 1907, 7, 286 ; A., ii, 120.69 lbid., 1908, 10, 193; A., ii, 608238 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.subject once more to my Report of last year. Choline does notpass as such into the urine; therefore if this test for nervousdegeneration is employed, the patient must be prepared to sacrificea small quantity either of his blood or cerebro-spinal fluid. Theexamination of the urine does, however, give some indication ofnervous breakdown (in the actual, not the figurative, sense), forBauer70 has shown that the trimethylamine of the urine is con-siderably increased in such circumstances. This product of lecithindegradation is also increased by the administration of foods richin lecithin.It is not increased if the nervous disease is functional(that is, figurative rather than actual).A few years ago Donath stated that choline is discoverable,at any rate, in one disease, usually reckoned as functional, namely,epilepsy. Kajiura71 in my laboratory has shown that this is notso, and has pointed out how Donath made his mistake.H. MacLean72 finds that only 52 per cent. of the nitrogen oflecithin is recoverable in the choline. He therefore suggests thatanother nitrogenous base may be present in lecithin; or, of course,it is possible that his method for the collection of the choline wasnot sufficiently accurate.C. Schwarz and R. Lederer 73 identify the substance that lowersblood-pressure in extracts of the thymus, spleen, and lymphaticglands, as choline; v.Fiirth and Schwarz74 find the same truefor the depressor substancs in thyroid extracts; and the sameobservers 75 have also stated that the secretin of Bayliss andStarling contains considerable quantities of choline. Cholineproduces a flow of pancreatic juice, but it is not identical withsecretin, the action of secretin on the pancreatic flow being onlypartly neutralised by atropine, whilst that of choline is whollyinhibited by the same alkaloid.Speaking of the antagonisms of choline leads me next to mentionan investigation by A. Lohmann,76 who finds that adrenaline andcholine are antagonistic so far as relates to blood-pressure, cardiacactivity, and intestinal peristalsis, but not in relation to thediabetic condition which adrenaline sets up.The foregoing mention of secretin leads me into anotherparenthesis, and a reference to a polemical paper by L.Popielski.77He still considers that pancreatic secretion is largely influenced7o Bcitr. CJLWL PhyslsioZ. Path., 1908, 10, 502 ; A . , ii, 717.71 Qiia;'t. J. cxp. PhysioZ., 1908, 1, 291 ; A . , 1909, ii, 71.7'L Zeitsch. physiob. Cheyn., 1908, 57, 296 ; A . , ii, 967.78 PJEuver's Archiv, 1908, 124, 353 ; A . , ii, 968.i4 Ibid., 361 ; A., ii, 968.i6 Ibid., 1908, 122, 203 ; A . , ii, 407.77 f b i d . , 1907, 120, 451 ; A., ii, 119.75 Ibid., 427 ; A . , ii, 963PHYSIOLOGICAL CHEMISTRY. 239by nervous reflexes; he finds that extracts of all parts of thegastro-intestinal mucous membrane produce the effects of " so-called secretin," and is not limited to the upper portion of theintestines.He also calls Bayliss and Starling to book for labelling,with a chemical name, a substance of which they kriow nothingchemically. This is a, piece of good advice which he unfortunatelyforgot to apply to his own work a few months later, when henamed the unknown substance in Witte's peptone which lowersblood-pressure, vaso-dilatin.78A somewhat lengthy communication on the physiological actionof choline by G. Modrakowski 79 must next be referred to ; he findsthat this substance, prepared synthetically, does not, when abso-lutely pure, produce lowering of blood-pressure, as all previousobservers have found. On the contrary, it raises blood-pressure.This, however, does not invalidate the work of those who haveused the depressor effect usually seen as a physiological test forcholine, for extraordinary precautions have to be taken to preventthe pure choline from undergoing that change which leads to thedevelopment of a depressor modification.The impurity or modi-fication which causes the fall of blood-pressure is also consideredto be responsible for some other physiological effects previouslyascribed to choline; it is neutralised by atropine, and that,according to Modrakowski's view, is the reason why even impurecholine will produce a rise in blood-pressure after an animal hasbeen atropinised.KephaEin.-This is a monoamino-monophosphatide, concerningwhich we know much less than we do of lecithin. I f an etherealextract of brain is evaporated and the residue treated with alcohol,lecithin enters into solution, but kephalin remains undissolved. Itsname indicates the waxy nature of this compound.On decomposi-tion, it yields phosphoric acid, and fatty acids which are lesssaturated than oleic and probably belong to the linoleic series. It isquestionable whether the base it contains is choline. It is foundalso in egg-yolk, and appears to be the most abundant phosphatidein nerve fibres, and that this is contained not merely in the medul-lary sheath is seen by comparing the figures for medullated and non-medullated fibres. F. Falk 8O gives the following numbers :Medullated nerve. Non-medullated nerve.Cholesterol .....................25.0 pcr ctnt. 47'0 per cent.G e phalin ........................ 12-4 , , 23'7 ,,Cerebrosides .................. 18 -2 , , 6-0 ,,Lecithin ........................ 2.9 ,, 9.8 ..78 Arch. exp. Path. Pharrn., ,SuppZ., 1908, 435 ; A . , ii, 1059.79 PJluger's Archiv, 1908, 124, 601 ; A . , ii, 974.go Biochem. Zeitsch,, 1908, 13, 153 ; A., ii, 966240 ANNUAL REPOltTS ON THE PROGRESS OF CHEMISTRY.Under the heading of the second group of phosphatides, in whichthe N : P ratio is 2 : 1, we have to consider two substances, namely,sphingo-myelin and amido-myelin.Sphingo-myelin was the name well selected by Thudichum forthis material, on account of its sphinx-like character. It is theconstituent of so-called protagon which contains the phosphorus,and it is the one which is slowly deposited from a solution ofprotagon in pyridine.It resembles lecithin in yielding choline oncleavage, but differs, among other points, from the phosphatidesalready mentioned in yielding no glycerol on decomposition. Thenature of the alcohol which takes the place of glycerol is uncertain.It may also be prepared from the cortex of the suprarenal body,and exhibits a physical phenomenon which has hitherto not beendescribed in connexion with any other substance; this was dis-covered by Rosenheim and Miss Tebb81 during their work on theoptical activity of protagon." Protagon," dissolved in pyridine, possesses a t 30° a slightdextrorotatory power, which changes to optical inactivity a t higheror lower temperatures, showing a maximum laevorotation of - 2 4 2 Oand a final constant laevorotation of [a]: - 1 3 . 3 O .Wilson andCramer had also noticed the constancy of this figure, althoughthey omitted to note the change of sign, and they took thisconstant as one of their proofs for the chemical entity of protagon.The explanation of the change is as follows: When a solution of'' protagon '' in pyridine is kept a t 20°, sphingo-myelin is precipi-tated, and it is the appearance of this precipitate of fluid sphzero-crystals which gives rise to the high lzvorotation; as the pre-cipitate settles, the laevorotation decreases, and the final lzevorota-tion is due to a minute quantity of the precipitate which doesnot settle. But if the precipitate is removed by filtration orcentrifugation, the fluid (which then contains the cerebrosidesonly) is optically inactive. I f the precipitate is once more shakenup with the fluid, high laevorotation is again obtained, whichlessens as the precipitate once more settles. This is the first timeoptical action of this nature has been observed in substances notactually in solution, and the term sphaerorotation is proposed forthe phenomenon. Although these observers express the highlaevorotation in the usual way, the optical activity of the pre-cipitated material does not follow Biot's laws.A mido-my elin.-This is another monoamino-diphosphatide de-scribed by Thudichum which has not been examined since histime. It possesses the protein-like character of being coagulableby heat.81 J. Phpiol., 1908, 37, 348; A . , ii, 879PHYSIOLOGICAL CHEMISTRY. 241The third group of the phosphatides contains those in whichthe N : P ratio is 1 : 2. Thissubstance received its name from Erlandsen,82 who first found itamong the phosphatides of heart muscle, but it has since beenfound in liver and other organs, and also (or a correspondingmonoamino-diphosphatide) in egg-yolk.83 On decomposition ityields glycerol, fatty acids, and a base, but the nature of thesela,&-named constituents has not yet been made out.The remaining groups of the phosphatides we know still lessabout, and beyond their enumeration already given in the classi-fication on p. 230, there is practically nothing to say about them.There is, however, one more substance which we must mentionin order to make our survey complete, and this is jecorin. Witha brief description of this substance, our account of the lipoidsmay be brought to a conclusion.Jecorim-This material was originally so named by its discoverer,Drechsel, who found it first in the liver, and later in other organs.Much doubt has ,been expressed concerning its chemical indi-viduality; the yield of sugar from it was found to be inconstant,and it has therefore been very generally regarded as one ofnumerous adsorption or similar compounds of lecithin and sugar,the proportion between which varies with the amount of sugarin the organ it is obtained from, The recent work of Baskoff B4has, however, shown that by a careful method of preparation it ispossible to obtain a product of constant composition yielding e l 4 percent. of sugar and a considerable quantity of incorporated ash.He has further shown that the phosphatide in combination withthe sugar is not lecithin, but a member of the diamino-monophos-phatide group.It was my intention, on starting this Report, to conclude it withan account of recent work on the pituitary body. I find nowthat I have already overstepped the limits of the space allotted tome, and so I propose to postpone the consideration of this interest-ing gland to my next Report. The work in relation to this subjectis still unfinished, so there may be a more complete story to tellthis time next year.The best known of these is cuorin.W. D. HALLIBURTON.82 d., 1907, i, 371.83 H. MacLean, Zeitsch. physiol. Chem., 1908, 57, 304 ; A . , ii, 963.84 Zeitsch. yhysiol. Chwz., 1908, 57, 395 ; A., i, 1029.REP.-VOL. V.

ISSN:0365-6217    

DOI:10.1039/AR9080500210

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.DURING the past year the activity of the many workers in thisvery varied field, which includes the chemistry of the soil and ofthe nutrition of both plants and animals, has been well maintained,although nothing very novel has come to light either in the wayof a discovery or a new point of view. We are advancing towardsan analysis and a reconstruction of all the varying play of forcesinvolved in the growth of a plant from seed round to seed again,but in reviewing the progress effected during a year one is moreconscious of the flight of time than of the lessened distance to thegoal. Very often, indeed, a large proportion of the work seemsto be devoted to the undoing of previous investigations, but theconditions under which a plant grows are so complex, and itsdevelopment represents the resultant of so many different actions,that investigations which seem t o lead to definite conclusions inthe laboratory are apt to be true only for that particular set ofcircumstances, and to have only a limited application to the openfield, where the results may be determined by some other factor nottaken into account in the experimental work.Soil Bacteriology.I n connexion with the bacteriology of the soil, attention is stillmainly directed to the question of nitrogen-fixation, for althoughthe main facts are not in doubt, there are considerable differencesof opinion as to the magnitude of the part played by the differentraces of nitrogen-fixing bacteria in Nature.As regards Azotobacter C ~ ~ O O C O C C Z L ~ , the most active of thebacteria which fix nitrogen when free in the soil, its originaldiscoverer, M.W. Beyerinck,l has abandoned the idea, which heonce put forward, that the actual fixation is effected by anotherorganism, Radiobacter, living in symbiosis with Azotobacter ; henow agrees with the many other observers, who kept to his originalopinion, that Azotobacter is the effective agent. Beyerinck suggests,1 Proc. K. Akad. Wetensch. Amsterdam, 1908, 11, 6’1 ; A . , ii, 9’15AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 243the use of calcium malate, instead of mannitol or glucose, in theculture media used for identifying the presence of Azotobacter insamples of soil, because a larger number of organisms develop intocolonies on this medium tha,n on the more usual ones containingsugar.He also makes the interesting statement that colonies ofAzotobacter seem to be associated with the roots of leguminousplants even when they are not abundant in the rest of the soil,an observation which requires careful examination to see if thisassociation is confined to leguminous plants. Krzemieniewski 2explains the superior nitrogen-fixation per gram of sugar oxidisedwhich is found when the inoculation is made with a raw soil extractinstead of a pure culture of Azotobacter, as due to the smallquantity of soluble humate that is added with the soil extract.It was found that pure cultures of Axofobacter could be stimulatedto a much greater fixation by the addition of a little sodium orpotassium humate.On the other hand, Lohnis and Pillai 3 concludethat humus alone is about the least effective source of carbon forthe Azotobacter organism, mannitol and xylose being most effective ;dextrose, starch, sodium tartrate, calcium lactate, sodium propionateare successively lower down in the scale. These authors also give aseries of measurements of the activity of the organism in soils thathave received different manurial treatment, and in the same soila t different times of the year; but their results are not veryconvincing, probably because their method of determining theactivity of the soil was not satisfactory. Among the chief desideratain connexion with soil bacteriology are satisfactory methods formeasuring the power of a given sample of soil to bring about certainkinds of bacterial action, for example, nitrogen-fixation, nitrifica-tion, production of ammonia, protein fission, etc.; for none of thosewhich have been hitherto proposed seem to give results in accordwith the field experience. Stoklasa and his co-workers4 have alsodiscussed the relationship of Radiobacter to Azotobacter, and findthe former of little value as a nitrogen fixer; they, too, havecompared the various sugars as sources of carbon for A zotobacter,and state that I-arabinose is the most effective, and that all theother monosaccharides possess much the same value, considerablyabove that of the disaccharides. The same workers have beenstudying the chemical reactions involved in the fixation of nitrogen ;they found that from dextrose the chief product was carbondioxide, but ethyl alcohol, formic, lactic, and acetic acids were alsoproduced, * and some hydrogen was always liberated.Stoklasa isBUZZ. Bcacl. Sci. Crncow, 1907, $46.Centr. Bakt. Par., 1908, ii, 20, 781 ; A , , ii, 522.Ibid., 21, 484, 620 J A . , ii, 880, 975.R 244 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.very positive above the hydrogen and the ethyl alcohol, the forma-tion of which other observers have denied; but in all probabilitythe reaction varies with the source and the activity of the particularculture of ,4 zotobacter employed.The magnitude of the part played by Azotobucter in Nature isstill a matter of uncertainty.J. G. Lipman 5 has made a numberof inoculation experiments with soil treated in various ways, butwithout any very positive results to show that the Azotobucter hadsucceeded in fixing enough nitrogen to affect the yield of the cropafterwards grown in the soil. As this author, however, verysoundly points out, the mere inoculation of a given organism intoa soil in which it was previously lacking, is never likely to resultin its establishment therein, unless a t the same time the generalsoil conditions are made suitable for it. The absence of theorganism is in itself most probably an indication that the soil isnot a fit medium for its growth, nor can it be established untilthe inhibiting factors have been removed.Since the discovery of Clostridium, Aeotohacter, and their relatedorganisms which will fix nitrogen when grown on suitable nitrogen-free media, the power of fixing a little nitrogen has been attributedto a large number of other organisms; indeed, it has been supposedto be a property common to all oxidising bacteria under fittingconditions ; Bredemann reports studies on a bacterium onlyabout one-fourth as effective as Azotobacter.Frohlich 7 makes outthat certain fungi associated with dead leaves, etc., possess thepower, whilst Hannig8 maintains that a certain grass, whenassociated with a parasitic fungus on the root, will bring some freenitrogen into combination.As regards the nitrogen-fixing bacteria associated with leguminousplants, there is nothing new to record; cases continue to be reportedwhere inoculation of the ground with the nodule organism hascaused a marked increase in the yield of the crop, but they referto relatively exceptional soils or crops ; under ordinary farmingconditions nothing appears to be gained by inoculating the seedsof such staple crops as clwer or beans.Reports appear from timeto time that the nodule organisms have been made to associatewith non-leguminous plants, but no evidence is yet forthcoming.Nitrification continues to receive some attention; L. C. Coleman 9has been studying the effect of organic matter, which the earlyinvestigators of nitrification had regarded as inhibitory of nitrifica-28th Ann. Rep. New Jersey State Agric. Exper. Stat., 1906-1907, 141 ; A ., ii,Centr. Bakt. Par., 1908, ii, 22, 44.Centr. Bakt. Par., 1908, ii, 20, 401, 484 ; A , , ii, 315.615.Ibid., 21, 162.8 Bey. Do&. bot. Ges., 1908, ii, 26a, 238 ; A . , ii, 523AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 245tion. He found, however, that small quantities of dextrose, upto 0.5 per cent., increased the rate of nitrification in non-sterilisedsoils, and a similar effect was seen when 0.02 to 0.05 per cent. ofdextrose was added to pure cultures. Karpiliski and Niklewski 10obtained similar results with humates and soil extracts, also withsugar and acetates, which latter salt Coleman found injurious tothe process. These contradictions, which are always turning upwhen the nutrition of bacteria is being examined, only emphasisethe need for caution in drawing conclusions from laboratoryexperiments as to the behaviour of soils in the field.Hall, Miller, and Gimingham 11 have examined the biologicalcondition of some of the Rothamsted soils which have become acidthrough the repeated application of ammonium sulphate andchloride.I n these soils, nitrification is practically a t a standstill,and the nitrification organisms are only to be found sparsely, ifa t all. The authors show that the acidity is mainly due to freehumic acid, although a little hydrochloric and sulphuric acids mustalso be present to a greater extent after the application of themanures than later in the year. The acid arises from the ammoniumsalts, which are split up by certain micro-fungi and moulds abun-dant in the soil of these plots, the ammonia being utilised bythe fungus and the acid set free.These acids have year by yearattacked the calcium humate in the soil and set free humic acid,which, being sparingly soluble, has accumulated. The poor growthto be seen on these acid plots may be put down to the fact thatthe grasses are driven to draw their nitrogen directly from theammonium salts without previous nitrification, and generally to themanner in which the acidity of the medium causes the replacementof the normal bacteria in the soil by a fungus flora, which competeswith the crop for manure and plant food in the soil.Hall and Miller l2 have attempted to oxidise by soil bacteria thenitrogen compounds contained in powdered rocks taken from greatdepths beyond the reach of any weathering processes, chiefly clayswhich show a considerable proportion of nitrogen.They foundthat some of this maherial was convertible by bacteria intonitrates-more than could be accounted for by the ammonia whichthey also found to be always present in these rocks. The processof nitrification is, however, very slow, and the authors considerthat some of the nitrogen compoiinds in soils may originally havebeen present in the rock out of which the soil was formed byweathering, being, as it were, in a mineralised condition unavail-able for the plant.lo Bull. Acad. Sci. Cracow, 1907, 596 ; A . , ii, 123.11 Proc. Roy. Xoc., 1908, 80, B, 196 ; A . , ii, 624. l2 J. Agric. Ski, 1908, 2, 343246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.M.C. Potter 13 has isolated an organism from garden soil capableof oxidising amorphous carbon in the form of coal, peat, charcoal,etc., which would seem to indicate that such fossilised organicmatter is even more attackable by bacteria than previous observershad supposed.The question of whether the soil bacteria aid in the solution ofsuch nutrients as tricalcium phosphate has received further atten-tion. Perotti14 considers that the attack only takes place whenthe nitrogen compound present in the culture medium is aphysiologically acid one, for example, ammonium sulphate, andthis would agree with Soderbaum’s experiments.15 Sackett, Patten,and C. W. Brown,l6 however, think that other factors come into play,such as the carbon dioxide excreted by the organism, or the specificacid it will form when supplied with an appropriate source ofcarbon.Even the potash of leucite is attacked when it is intro-duced into cultures of acid-producing moulds.17Voorhees, Lipman, and 9. E. Brown 18 have examined some of thechemical and bacteriological results of liming the soil, and findthat after an application of lime the bacterial activity of the soil,as measured by its power of making ammonia from gelatin or itsnitrate content, is considerably increased. I n their trials, purelime was more effective than a magnesian lime made from dolomite,and calcium carbonate was often more effective than either.Soil C l ~ e n ~ i s t ry .The theory of the action of fertilisers, which we owe to Whitneyand his colleagues in the Bureau of Soils of the U.S.Departmentof Agriculture, has received considerable developments during theyear. Briefly, the theory is that each plant excretes duringgrowth certain substances toxic to itself but not to other plants;infertile soils are those in which such substances have accumulated;fertilisers act, not by directly feeding the plant, but by neutralisingor otherwise putting out of action the toxic bodies excreted byprevious crops. Since last year’s Report the point of view seemsto have changed somewhat; no further work is reported on whatwas the prime hypothesis (that the soil water possesses a constantcomposition which is unaffected by the addition of fertilisers) andinstead of excretion from the plant itself, the toxic substances are‘l3 P~oc.Roy. SOC., 1908, B, 80, 236 ; A , ii, 524.l4 Atti R. Accad. Lincei, 1908, [v], 17, i, 448; A . , ii, 527.l5 Landw. Versttchs.-Slnt., 1908, 68, 433 ; A . , ii, 728.l6 Ccntr. Bakt. Par., 1908, ii, 20, 688 ; A . , ii, 415.l8 New Jersey State Aqric. Exper. Stat. Bttll., 1907, 210 ; A , ii, 317.Grazia and Camiola, Bied. Zen.fr., 1908, 37, 207 ; A . , ii, 415AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 247now supposed to arise from the action of bacteria, etc., on theresidues left by the crop in the soil. This is a different hypothesis,which, with a little extension to include the action of the bacteriathemselves, and the abandonment of the quite unnecessary sup-position that fertilisers precipitate or destroy the toxins, it is onewhich merits very careful attention, as affording an explanation ofvarious difficulties met with in the field.The most noteworthyfacts in this connexion are the isolation from certain infertile soilsby Schreiner and Shorey l9 of small quantities of two substances,picolinecarboxylic acid and dihydroxystearic acid, which the authorsregard as toxic. Both these substances were obtained from thecoloured extract which remains after an alkaline extract of theorganic matter of the soil has been precipitated by an acid; theywere prepared in crystalline form, and have been duly identified;the picolinecarboxylic acid may be regarded as a product of thedecay of protein in the soil, just as dihydroxystearic acid maywell be a derived product from some plant fat containing oleic acid,or possibly of a protein also.Evidence is brought to show thatboth these substances, and especially the ,latter, are toxic tovegetation, and the conclusion is further drawn that they con-stitute the source of the infertility of the soils from which theyare derived. From 1 kilo. of an infertile cotton soil, 0.05 gramof dihydroxystearic acid was obtained, although more was presentin the soil. It is just the evidence f6r the toxicity of these com-pounds which seems open to criticism; the method employed wasto place series of ten young wheat seedlings in bottles containingdistilled water, to which varying amounts of the substance underinvestigation have been added.The growth of the wheat seedling(which was still deriving its nutriment from the endosperm) wascontinued for about ten to twelve days, and was measured both bythe amount of water transpired and by the increase in weigh1 ofthe seedling. The following table shows the sort of numbersobtained :Transpiration. Green weight.Control-distilled water only . . . . . . . . . . . , . . . . . . . . .1 per million of picolinecarboxylic acid ... ... 140 9510 7, 9 J ,, ...... 105 10150 2, 9 , , , . . . . . . 107 98100 , 7 $ 9 , , . . . . . . 85 892oo 1 1 Y Y ,, ...... 55 70100 100To anyone acquainted with the great individuality exhibited bywater cultures, and the many ways in which such experimentswill fail even when growth is going on in nutrient solutionsand not in water alone, these figures will not appear very con-l9 J .Amer. Chem. Soc., 1908, 30, 1295, 1599; A . , ii, 889, 1067248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.vincing. No actual weights are given, and although we gatherthat the trials were made in duplicate, the two sets are not givenseparately; thus we have no means of estimating the experimentalerror, which we know must be large. Furthermore, a substancemay be very toxic in a water culture, where the plant is set togrow in distilled water and nothing else, but there is no guaranteewhatever that it will behave in the same way in the soil, whichpossesses an enormous power of withdrawing organic substancesfrom solution. The substances which Schreiner and Shorey haveisolated are of great interest, and open up a new field in the studyof the organic matter of the soil, but they demand a good dealmore investigation before they can be accepted as the causes ofthe infertility of the soil.For example, a soil rich in organicmatter-the accumulation of previous vegetation-is in most casesextremely fertile; are such soils richer or poorer than the averagein these so-called toxins?In another paper, Schreiner and Reed20 attempt to show thatvarious bodies used as fertilisers destroy or otherwise mask thetoxic action of organic plant poisons on wheat seedlings. Thefertilisers employed were sodium nitrate and calcium carbonate,the toxins, coumarin, arbutin, and cinnamic acid, and the methodof experiment has already been described.The authors give thefollowing table to show the beneficial action of calcium carbonate.rNoaddition.100133,, 25 ,, ..................... 80Control : distilled water oiily.,. .........Vanillin 1 per million .....................,, 10 ,y ..................... 126,, 100 ,, ..................... 53,) 500 ,) ..................... 25CaCO, arldcd2000 per million.2092011841831271 O iAgain no actual results are given by which the experimentalerror may be checked; the increases seen with 1 and 10 per millionof vanillin are set down to the stimulus brought about by smalldoses of poisons (no case has yet been made out for the generaltruth of this theory of stimulus), but no explanation is attemptedof the fact that calcium carbonate added to the pure distilledwater in the control experiment increased the growth from 100 to209.By parity of reasoning, the distilled water must have beenthe toxin in this case.Schreiner and Sullivan 21 claim to have extracted from (( wheat,-sick ” soil a substance toxic to wheat, and from ‘( cow pea-sick ”soil a substance toxic to cow peas, although not to wheat, but nodetails are yet given.J. Amer- C7~m. Soc., 1908, 30, 8 5 ; A . , ii, 420.a1 J. Bid. Chem, 1907, 4, sxvi ; A , , ii, 422AGRICU1,TURAL CHEMISTRY AND -VEGETABLE PHYSIOLOGY. 249We have dealt with these papers a t some length because it isonly by close attention to the details that they can be judged;each of the papers which emanates from the Washington Divisionof Soils begins with a convinced exposition of the theory to beproved, and the reader does not always see that the experimentswhich follow, although they will agree with the theory, are veryfar from a demonstration -of its truth.If the American authors of the theory seem to be weakening ontheir original hypothesis that the plants excrete the toxins, theirold view has found an independent supporter in India. F.Fletcher22was led by certain considerations as to the vigour of the plants inthe outside rows of experimental plots, the well-known “ falloweffect,” to regard this increased growth as due to the comparativefreedom of their roots from toxins excreted by neighbouring plants.He then proceeded to make water cultures with certain plants,cotton, sorghum, etc.; he grew young seedlings in well-water fortwenty-one days, three times in succession in the same liquid,the volume being kept constant by fresh additions of water.Finally, the solutions thus obtained were allowed to evaporatein a room until in each case about 20 litres of original well-water were reduced to something between 1 and 2 litres.Intothese liquids fresh seedling plants were put to grow, but werefound to wither and die very quickly, a result the author setsdown to the concentrated toxic excretion. On this part of thework certain criticisms suggest themselves-the plants grown inthe solutions were really large germinating seeds, in the stage,therefore, of breaking down the protein and other reserve materialscontained in the seed.It is well known that the roots of suchyoung seedlings will part with soluble nitrogenous and othercompounds to any solution in which they are growing, but onemust not argue from the germinating seedling to the normalgrowing plant, which, as a rule, has not such an excess of nitrogenas to be able to waste any in excretions. Moreover, these watercullares were made in broad, flat vessels, and were allowed toconcentrate by standing in a room a t an Indian temperature; inwhat sort of a bacterial condition were they likely to be a t the end,and what products may not have been formed! There is someindication that the toxicity of the solutions followed the size of thegerminating seeds utilised in each case, but data are lacking.Again, well-water, concentrated to one-tenth of its volume withoutany check against bacteria, may itself provide something toxic,and it is significant that the worst results were obtained in thecase where 23 volumes of well-water were concentrated into one foraz Mem.Dept. Agric. Zndicc, Bot. Xer., 1908, 2, No. 3 ; A., ii, 617250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the final test. Other difficulties could be raised, but these willbe enough to show that the author subjected his results to nocritical examination; it seems a property of this toxin hypothesisthat its holders set out with the theory and are content if theirexperiments will fit, without risking any crucial experiments totry whether they will fit that theory only and no other.Fletcher considers that his results show all crops to yield thesame toxin; he gives a number of reactions which the substanceshows, for example, it is precipitated by potassium hydroxide,sodium chloride, dilute sulphuric acid, among other reagents, butin view of the very doubtful origin of the material it is perhapshardly worth while considering what these reactions indicate.S.U. Piekering23 has also entered the “soil toxins” field ofdiscussion with a series of experiments showing that many seedsgerminate more slowly in soil that has been heated, the “incuba-tion” period increasing with the temperature from 60° to 1 5 0 O .I n general, the percentage germination also diminishes with thetemperature.The soils are shown to contain more soluble matter,both organic and inorganic, after heating, and it is to this increasein the soluble nitrogenous matter by heating that Pickering attrj-butes his results. He concludes that most soils contain substancesfavourable to germination which are converted into inhibitorysubstances on heating, although some soils probably containinhibitory substances at starting. Pickering also considers thatthis increase of soluble nitrogenous bodies accounts for the resultsobtained by Darbishire and Russe11,24 who found that the growthof plants is much increased by a preliminary heating of the soil,in which case the substances which retard germination eitherbecome destroyed before plant growth begins or have no necessaryconnexion with it.Pickcring dismisses soil bacteria as an effectiveagency either in his own or in Darbishire and Russell’s results, buthis original experimental figures seem to form too slender a founda-tion for the wide conclusions he draws from them.Soil Physics.This branch of the subject is still sadly neglected, although it isrecog-nised that both the soil flora and the nutrition of the plantare determined more by the movements of water and air in thesoil than by any other single factor; during the year, however, oneor two interesting papers have appeared. F. J. Alway25 has mademeasurements of the soil moisture in the semi-arid i‘ great plains ”regions of Saskatchewan and the North-West. He obtained28 J. Agric.Xci., 1908, 2, 411.25 J. Agrie. Sci., 1908, 2, 333.24 Ann. Report, 1907, 265AGRICULTURAL CHEMISTRY AXD VEGETABLE PHYSIOLOGY. 251samples, by means of an auger, down to the depth of six feet fromland which had been cropped and from adjacent land which hadbeen fallowed in order to accumulate the rainfall for a crop in thesucceeding season. By determining the hygroscopic moisture ofeach sample, that is, the amount absorbed by the dry soil from asaturated atmosphere, and regarding the difference between thisand the actual water in the soil when sampled as the ‘( free ” waterwhich would be available for a crop, the author claims to be able todecide, a t the commencement of a season, whether the land containssufficient water for the needs of a crop.The author incidentallydenies that the soil in this region is frozen permanently, or that itsgradual thawing throughout the growing season keeps the cropsupplied with moisture. Alway’s figures would seem to indicatethat the crop chiefly depends for its water upon the store in thetop six feet-or so of soil, and that the moist soil below this yieldsup very little water by capillarity to the layers above. This isthe contention of J. W. Leather,26 who made a series of determina-tions of the amount of water a t various times during the year inthe uniform fine silt which constitutes the Indo-Gangetic alluviuma t Pusa. From the fact that a t about seven feet below the surfacea layer occurred which contained the same proportion of watera t the beginning and end of the dry period, Leather concludes thatthe loss of water by evaporation is confined to the higher levels,and that movements of water by surface tension from greaterdepths up to or near the surface do not take place.Leather’sresults, however, would be equally consistent with the view thatthe layer in question is in a condition not of static, but of dynamic,equilibrium it5 regards its water content, and that instead of losingno water to the layer above during the dry period, it has beenbalancing its losses by gains from below. The point can only besettled by determinations of the actual quantity of water lostby evaporation ; considering the importance of this question of therise of the subsoil water by surface tension or capillarity, it isvery desirable that further experiments should be set on foot.Souniversally is the capillary uplift of water from the subsoil regardedas the source of the resistance of certain soils to drought, that itis surprising to find how few and untrustworthy are the databearing on the subject.The question of the flocculation of the finest soil particles bysalts2’ has again been discussed by Rohland,28 who connects itwith the plasticity of the clay, the permeability of the soil to26 Mem. Dept. Agric. India, Chenz. Series, 1908, 1, 79.27 Ann. Report, 1907, 269.28 Lnndw. Jahrb., 1907, 36, 4i3; A., ii, 59252 ANNUAL REPORTS OX THE PROGRESS OF CHEMISTRY.water, and its surface tension and absorptive power, all of whichproperties depend on the colloidal substances in the soil formedby the weathering of the felspars.Chemist? of the Growing Plant.The supposed photosynthesis, outside the plant, of formaldehydeand then of starch, by Priestley and Usher 29 has been subjectedto severe criticism,3O and their work is generally only regarded asaffording support to the hypothesis that formaldehyde is the inter-mediate step between carbon dioxide and a sugar, although E.Baur31 discusses the possibility of oxalic acid being the first stagein the synthesis.The formaldehyde theory is supported by B.J. Harvey Gibson,32who has published a short note outlining a theory of photosynthesis,according to which the passage from carbop dioxide and water toformaldehyde is brought about by electric currents in the leaftissue, generated by the incidence of the light rays. He is ablet o show by a new test that formaldehyde is present in all greenleaves, the amount present bearing a definite relation to theillumination, and he also shows that a silent electrical dischargewill generate formaldehyde in a solution of carbon dioxide.Theelectric currents in the leaf tissues and their variation with theillumination have been demonstrated by other investigators.S. Strakosch 33 has been studying the other end of the assimilationprocess as it goes on in the leaf of the beet; he finds only dextrosein the mesophyll; sucrose appears later in the leaf veins aftermigration of dextrose has begun. Starch is not found until laterstill, after there has been some accumulation of sugars in the leaf.The formation of sucrose is dependent on light, but the amountof monosaccharides in the leaf remains almost constant whetherthe leaves are exposed to light or kept for some time in the dark.The sucrose migrates from the leaf to the root without undergoingany change, whereas, according to F.S t r ~ h m e r , ~ ~ when the reversenigration takes place in the second year of the plant’s growth, thestored sucrose in the root is converted into invert sugar before itcan be moved back to the leaf, where it is re-synthesised.The old question of whether t-he endosperm of barley and similar* Proc. Boy. Soc., 1906, B, 77, 369; A . , 1906, ii, 299.90 Ewart, ibid., 1908, B, 80, 30; A., ii, 217 ; Mameli and Pollacci, Alti 3.31 Zeitsch.physikal. Cham., 1908, 63, 683 ; A., ii, 790.32 Ann. of Botany, 1908, 22, 117.33 Zeitsch. Vcr. deist. Zuekcriizd., 1907, 1057 ; A . , ii, 125.34 Oesterr.-umg. Zeitsch. Zuckerind. Anndw., 37, 18 ; A , , ii, ’126.Accnd. Lincci, 1908, [v], 17, 1, 739; A., ii, 881BGIiICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 253seeds possesses any vitality, or is to be regarded as a dead magazineof reserve food, has continued to attract attention. D. Bruschi35brings evidence to show that the vitality varies with the natureof the seed; all gradations may be observed between maize, in whichthe glutinous part of the grain is alive, and rye, in which theendosperm is wholly dead ; wheat and barley being intermediate,in that a few layers of cells below the aleurone layer retain somevitality.F. Stoward 36 shows that the purely endospermic tissueof both barley and maize will respire and exchange carbon dioxidefor oxygen, thus bringing evidence of another character in favourof the continued vitality of these cells.The changes taking place in the nitrogenous compounds ofplants when the proteins are hydrolysed during the germinationof seeds and subsequently reformed in the growing shoot, continueto attract much attention, since on these very complex actionsdepend a good many technical differences of importance which thepractical man sums up under the name of quality ” in the seedsor their products. H. T. Brown has published two importantpapers37 on the soluble nitrogen compounds in malt and on themovements of such bodies from the endosperm into the embryo,as studied by presenting them to the detached embryo in watercultures.Asparagine was found to be the best nutrient, and wasproved to exist in malt, but it was not settled whether it was to beregarded as a down- or an up-grade product. N. Wassilieff,38 instudying the formation and migration of proteins during theripening of seeds of lupins, finds asparagine in the unripe fruits,but regards it as a,n intermediate stage in the upbuilding ofproteins from amino-acids, previously formed by the hydrolysis ofproteins in the husks, etc. Scurti and Parrozzani39 came to theconclusion that in the germination of sunflower seeds asparagine isnot a down-grade product formed directly from the proteins, sinceit only is found during the more advanced stages of the germinationprocess when the up-grade actions have begun.The organic phosphorus compounds of seeds and plants areattracting increasing attention, and a number of papers 40 have35 Ann.of Botany, 1908, 22, 449.57 Trans. Gainness Lab., 1, ii, 288; A., ii, 882 ; J. Inst. Brewing, 1907, 13,38 Ber. Ueut. bot. Qes., 1908, 26a, 454 ; A . , ii, 976.40 Stutzer, Biochem. Zeitsch., 1907, 7, 471 ; A., ii, 124 ; Suzulri and Yoshimura,Bull. COX Agric. T6ky6, 1907, 7, 495 ; A . , ii, 124 ; Winterstein and HiesstandZeitsch. physiol. Chin., 1908, 54, 288 ; A., ii, 218 ; W. Windisch, Jahrb. Yers.Lehr. Braucri, 1907, 10, 56 ; A., ii, 528 ; E. Schulze, Chent.Zeit., 1908, 32, 981 ;A . , ii, 977.36 Ibid., 415.394 ; A., ii, 883.Gazzetta, 1908, 38, i, 216 ; A., ii, 417254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.appeared on the determination of lecithin, phosphatides, phytin,etc., in plants. No general conclusions can yet be drawn, but thesesubstances will have to be kept in mind in connexion with problemsof ripening and quality.I n opposition to Willstatter,41 Stoklasa, Brdlik, and Just 42maintain that chlorophyll contains phosphorus, and is a lecithin-like substance which yields choline and glycerophosphoric acidamong its decomposition products.M. Wagner43 describes a series of experiments to ascertain howvariations in the nutrition, such as a deficiency or an excess ofnitrogen, will affect the development of the plant in such charactersas the relation of straw to corn, the time of ripening, etc.Theexperiments were made in pots with barley, oats, buckwheat, andmustard. It is not possible to draw any very general conclusionsfrom the results, although the paper should not be neglected byanyone interested in the specific functions of the elements ofnutrition; amongst other things, it is noticeable that the author’sopinion is against the view that phosphoric acid gives a specialstimulus to root development.E. Molz 44 has published a long study of the well-knownphenomena of chlorosis which occurs in the leaves of the vine andother plants, generally when growing on heavy calcareous soils. Heassociates its appearance with the formation of a putrefactive layeron the surface of the root, followed by the entry of calcium car-bonate and the consequent neutralisation of the sap, and bringsevidence to show that such conditions as would further any ofthese actions are recognised in practice as favourable to chlorosis.I n one or two districts in England, fruit trees and allied plants aregrown with difficulty because of their tendency to assume thischlorotic condition; the causes of the disease have never beencleared up, and it would be well if the cases were re-examined inthe light of Molds conclusions.The stimulus to the growth of plants which has been ascribed tothe salts of manganese forms the subject of several papers45 publishedduring the year, but the subject has received no real advancement,because it has not been settled if the supposed stimulus is due todirect action of the manganese on the plant or to some secondarydl A m a l w , 1908, 358, 267 ; A ., i, 199.42 Her. Deut. bot. Ges., 1908, 260, 69 ; A . , i, 279.43 Landin. Versorchs.-S’tnt., 1908, 69, 161 ; A . , ii, 1066.44 Centr. Bakt. Par., 1907, ii, 20, 71.H. vori Feilitzen, J. Lnmiw, 1907, 55, 289 ; -4., ii, 61 ; Uchiyama, Bdl. Imp.Centr. Agric. ExpeT. Stat. Japan, 1907, 1, 37 ; A . , ii, 126; W. F. Sutherut,.Transcaal Agric. J., 1908, 6, 437 ; A., ii, 628 ; Gre‘goire, Hendrick, and Carpiaux,BuEL Inst. Chim. Baet. Gembloux, 1908, No. 75, 66 ; A . , ii, 529AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 255action on the soil. In all these stimulus effects the prime fact of theexistence of increased growth also requires to be put beyond thereach of doubt, just as in the kindred case of the action of high.tension electrical discharges on plants, an old question which hasarisen again this year as the outcome of a large scale experimentnear Worcester.46Manures und Manuring.As regards fertilisers and manures, the record of the year issingularly blank.The new nitrogenous fertilisers, calcium cyan-amide (either “ kalk-stickstoff ” containing free lime or ‘( stickstoff-kalk ” containing calcium chloride) and nitrate of lime, continueto be the subject of a number of field trials, because they arebeginning to be put on the market in considerable quantities, buttheir behaviour is pretty much what was indicated in the earliesttrials.Considerable dispute still rages as to the exact nature ofthe decomposition calcium Cyanamide undergoes in the soil, andwhether bacteria are essential in bringing about the change, aswas originally maintained by Lohnis. A. D. Hall47 has alsopublished some experiments on the losses of ammonia experiencedby cyanamide on storage under moist conditions, and on the prac-ticability of mixing the f ertiliser with superphosphate before sowing.The heat developed is not unmanageable, there are no losses ofnitrogen, but the soluble phosphoric acid of the superphosphatebecomes precipitated ; the mixed fertiliser is, however, much moreconvenient for sowing than the original cyanamide.M. Popp 48 has continued the well-known experiments of Wagneron the f ertilising value of different compounds containing nitrogen,the experiments being made in pots, in some cases continued forthree or four years.From the final summary, giving the mean ofall the experiments, numbers like the following were obtained :I f the returns from nitrogen in sodium nitrate be taken as 100,then an equivalent amount of nitrogen in dried blood will return72, in horn meal 71, in castor cake 65, in bone meal 52. It hasnever been found possible to confirm these ratios in field work,where other factors come into play, particularly the influence ofthe fertiliser on the texture of the soil.Chemistry of Animal Nutrition.Since i t is generally accepted that during digestion the proteinsof the food are very completely broken down to amino-acids, etc.,before they are reconstructed in the intestinal wall, among the dataNature, 1908, 78, 331.Landw. Verszcchs.-Xtat., 1908, 68, 253 ; A , , ii, 727.J.Board Agric., 1908, 14, 654256 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.required for an adequate theory of animal nutrition is a knowledgeof the products of hydrolysis of all the proteins commonly occurringin feeding stuffs. Practical graziers know by experience that theproteins of all foods are not of equal value, nor is the same proteinequally suited to all animals, but it is only recently that we seeany means of placing these empirical results upon a, scientificbasis. Osborne and his co-workers have taken up this problem ofthe resolution of the vegetable proteins into their constituent amino-acids with great vigour, and during the year report49 the resultsof the hydrolysis of amandin, gliadin, hordein, zein, vignin,legumin, legumelin, leucosin, and vicilin. A.Kleinschmitt 50 hasalso reported a hydrolysis of hordein. The imperfection of maizeas a food is attributed by S. Baglioni51 to the imperfect digestionof the zein, which yields on partial hydrolysis large quantities ofphenylalanine in addition to phenolic compounds. The author seessome similarity between the symptoms of phenolic poisoning andtiJose exhibited by animals dying through exclusive feeding onrmize flour, but he does not seem to have taken into account theexperiments of Miss Willcock and Hopkins,52 who associate thenitrogen starvation which sets in when zein is the only nitrogenousfood with the absence of tryptophan (and also lysin) from the zeinmolecule.0. Kellner 53 discusses the lack of agreement between the amountof digestible protein in a feeding stuff as determined by pepsin,etc., and the figures, varying in themselves, obtained from estima-tions of the nitrogen in the fzces of different animals. Forexample, the digestion coefficient of the crude protein of potatoes,as determined by feeding experiments, was 31.9 with sheep and58.8 with pigs. Kellner considers that these differences are onlypartly due to the intestinal slime, etc., containing previouslydigested nitrogen, but are in t:ie main caused by the bacteria inthe intestine which build up insoluble proteins in the fzces fromprotein matter that has previously been digested, or from non-protein nitrogen compounds in the food. The many other paperswhich have been published on nutrition and digestion questionsare mainly of technical interest and do not break new ground.49 Amer. J. Physiol., 1908, 20, 470, 477, 493 ; A., i, 115 ; Amer. J. Physiol.,1908, 22, 362, 433 ; A., i, 744, 843 ; J. Bid. Chcnz., 1908, 5, 187; A . , i, 928, 929.6O Zeifsch. p h p i o l . Chem., 1907, 54, 110; A., i, 69.51 Atti Iz. Accad. Lincei, 1908, [ v ] , 17, i, 609 ; A . , ii, 619.82 Ann. Izcport, 1907, 276. 53 Ladw. Terszcchs. -Stat., 1908, 68, 463AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 257,4 nalytical.Attention may be directed to two papers on the determinationof small quantities of nitrogen and carbon in soils by Chouchak andPouget,5* which may occasionally prove useful when only a smallamount of material is available, although it is difficult to see whatsuperiority the method for nitrogen possesses over the Kjeldahlprocess followed by an estimation of the ammonia in the distillateby nesslerising, nor does the method for carbon promise to be moreaccurate than the modified wet combustion process.65A. D. HALL.Ii4 Bull. SOC. chin&., 1908, [iv], 1, 1173, 3, 75 ; A., ii, 223, 225.Ii5 Trans., 1906, 89, 595.REP-VOL. V.

ISSN:0365-6217    

DOI:10.1039/AR9080500242

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

CRYSTALLOGRAPHY.THE modes in which the behaviour and properties of crystallinesubstances can influence chemical theory may be roughly classifiedunder two headings. First, including those in which, with ourpresent knowledge, no special interest attaches to the crystallinenature of the solid substance; into this category fall all questions ofthe solubility of crystalline substances, and of the equilibriumbetween liquid and crystalline phases, or between two crystallinephases. Questions of this kind are not discussed in thepresent Report, because their experimental treatment has not yetprogressed so far as to render of importance the differences insurface character presented by the various kinds of crystal facesoccurring on one substance, and also because they properly formpart of the report on physical chemistry.The second categoryembraces the relation between the crystal structure and thechemical nature of substances, and to this subject alone the presentReport is confined.As a result of the study of crystalline structure, both in its ex-perimental and theoretical aspects, during the past hundred years,it may be stated that the whole of the physical, geometrical, andmechanical properties of crystalline substances are in harmony withthe following geometrical definition. A crystalline structure is ahomogeneous one, that is, a structure the parts of which are uni-formly repeated throughout, corresponding points having everywherea similar environment. The correspondence between this statementand the facts is so complete as to prove definitely that the charac-teristic which distinguishes crystals from all other bodies is this homo-geneity of structure.From the principle of structural homogeneitymay be a t once deduced the various forms in which the empiricallyobserved fundamental law of crystallography has been stated, suchas the law of zones, the law of rational indices, etc., and it is to beconcluded that the distinguishing feature of external regularity ofform assumed by a crystalline substance is correlated with theclass of homogeneous structure to which it belongs.An investigation into the structure of crystalline substances, aCRYSTALLOGRAPHY. 259defined above, may be regarded as involving two distinct inquiries.The first of these is concerned with the kinds of homogeneousstructure geometrically possible, and the second, with the natureof the units of which the homogeneous structure is built up.Thefirst inquiry, regarded as a purely geometrical one, has now beenprosecuted to a stage approaching finality. The second inquiryinvolves the application of geometrical methods to specific cases'which have been experimentally investigated ; its pursuit isattended with much difficulty, and it is but in the early stages ofdevelopment.The work which has been done on the possible kinds ofhomogeneity of structure has been well summarised in a report tothe British Association on the structure of crystals,' so that itwill suffice now to indicate very briefly and roughly the successivestages by which our present highly complete knowledge of thesubject has been attained.(1) Bravais (1850) effected an exhaustive inquiry into the variousways in which small identical regular bodies can be distributeduniformly throughout unlimited space, so that every one of themhas the remainder of the assemblage arranged about it in anidentical manner, and with the same orientation. The last con-dition involves the property that a linear translation of the entireassemblage, the length an4 direction of which are those of a linejoining the centres of any two of the bodies, produces coincidenceof the moved assemblage with the assemblage as it stood beforethe translation; the centres of the bodies consequently form aparallelopipedal network or a so-called " space-lattice.'' Bravaisshowed that fourteen kinds of such space-lattices exist, and thatthese correspond in their symmetry with the seven large crystalsystems.It may be noted that any movement or operation, such asthe translation just mentioned, which, after performance, leavesthe assemblage identical in aspect with its original, is convenientlytermed a '' coincidence movement "; in addition t o the linear trans-lations, some of the Bravajs space-lattices possess other coincidencemovements which are rotations about axes. The occurrence ofrotations about an axis as coincidence movements is expressed bynaming that axis one of symmetry, and, if the angular rotationproducing coincidence is 36Oo/m, the axis is described as one ofn-fold symmetry. The axial ratios of a crystalline substance, statedin the customary form of the value of a : b : c , represent the ratio ofthree linear translations of the space-lattice distributed in three-dimensional space.(2) Sohncke (1876) determined the possible kinds of homogeneousThese stages are three in number.Brit.Assoc. Report, Glasgow, 1901, 297.s 260 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYarrangement derivable by enlarging Bravais’s definition, the modifi-cation consisting in the abandonment of the condition that thesimilar environments of the units must be similarly orientated.This change of definition abolishes the necessity for attributing anyaxial crystal symmetry to the unit itself, and renders possible thegeometrical dissection of every symmetrical Bravais unit intoidentical smaller units devoid of axial symmetry.Substitutingmere points or small spheres for Bravais’s small regular bodies, andmaking the former as numerous as the coincidence movements,axial and translational, of the system under consideration, Sohnckemakes the configuration, namely, the coincidence movements ofhis systems of points, express all the identical repetition of partspresent. He discriminates sixty-five types of homogeneous structure,and these are known as Sohncke systems; in addition to the kindsof crystal symmetry exhibited by the Bravais space-lattices, theSohncke systems furnish types corresponding in symmetry withmost of the thirty-two crystal classes into which the seven largecrystal systems are subdivided.(3) The final step soon followed Sohncke’s important develop-ment of the possible ways of deducing homogeneous structures.It was perceived that the coincidence movements of a Sohnckesystem represent only identical repetition of parts, and leaveenantiomorphous likeness (or mirror-image resemblance) of parts tobe expregsed by some added condition.Bravais had modified theSymmetry of some of his space-lattices to meet this requirement byattributing to his small bodies the lower symmetry needed forcorrespondence with the facts. To avoid the necessity for any suchunsatisfactory contrivance, a further modification of the conditionof similar environment was now resorted to; it was seen that twopoints in an assemblage are similarly, although not iaentically,environed if the arrangement of the unlimited assemblage aboutone of them is the mirror-image of its arrangement about theother ; also that coincidence operations about centres of symmetryor planes of symmetry then perform the function fulfilled in theSohncke systems by the coincidence movements, and express therelation between similar points enantiomorphausly related.Fedoroff, Schonflies, and Barlow independently investigated theadditional forms supplied by this enlarged conception of similarityof environment, and proved that the admission of coincidenceoperations connecting similar points, the environments of whichpresent mirror-image similarity, leads to the discrimination of manymore types of symmetry ; the latter now provide representativesof all the thirty-two classes of crystal symmetry.The investigatorsjust named are agreed that the total number of types of symmetricaCRYSTALLOGRAPHY. 261.structure made possible by the further enlargement of definitiondefined above is 230, and these are described as the 230 types ofpoint-systems. As no kind of operation, other than such as areemployed in the Sohncke systems and the systems derived fromthem by mirror-image duplication, can form a component of acoincidence operation consistent with homogeneity of structure, thefirst part of the inquiry into crystal structure, that dealing withthe mode of arrangement of the parts, is virtually ended.A simple illustration will make clear the distinction betweenthe three kinds of similarity of position of members of a flock ofsimilar parts just described. Consider a stack of cubes, such as areused by children, built up in the ordinary way, so that the cubesare in face contact, and so that throughout the stack each cubecorner makes contact with seven other cube corners.The assemblageof points formed by the cube corners is a Bravais space-lattice.Each point in this space-lattice is common to twelve cube faces,each cube face being also common to two cubes in contact. Replaceone point of the space-lattice by a cluster of twelve points, onelying on each diagonal of a cube face drawn from the originalpoint, and all being equidistant from the original point.Repeatthis process throughout the system until each point of the space-lattice is similarly and symmetrically replaced by a cluster oftwelve. The assemblage built up by this symmetrical repetitionthroughout space of the cluster of twelve points about the originalcube corners of the space-lattice is a Sohncke system, and consistsof twelve interlaced space-lattices which are related by simple axialrotations: all the points are identically related to the entireunlimited assemblage.Next displace each point in a cluster of twelve from the planeof the cube face in which it lies, all the twelve being movedsimilarly, symmetrically, and in the corresponding direction, topoints just within the cubes; this operation can be so performedthat the resulting twelve-point cluster is no longer identicalwith its mirror-image.Treat an adjacent cluster in the sameway, but making the arrangement identical with the mirror-imageof the first, and repeat these operations symmetrically and alter-nately throughout space until all the original twelve-point clustershave been appropriately displaced; one of the 230 point systemsis thus generated. It consists of a Bravais space-lattice in whicheach point is replaced by a twelve-point cluster of enantiomorphousform disposed about the original point ; one-half of the clm tershave the right-handed, the others the left-handed, configuration.The assemblage may be also regarded as an interpenetration of aright- and a left-handed Sohncke system, one, namely, whicb i 262 ANNUAL REPORTS ON THE PROGRESS OF CHEMlSTRY.derived by a mirror-image repetition of either the right- or theleft-handed component Sohncke system.After this necessarily brief and incomplete sketch of the resultsarrived a t in the inquiry as to the mode of arrangement of partsholding in crystalline structures, attention may be directed towardsthe second kind of problem involved, that, namely, of the natureof the parts which are arranged.During the past century exactdata concerning the crystalline forms of some thousands of sub-stances have been obtained, and these are now being collected andrepublished by Paul Groth.2 Although until very recently nocomprehensive scheme had been advanced for reconciling thecrystalline form and chemical nature of substances in general,several results obtained, and conclusions drawn, stand out beyondothers as indications for the construction of such a scheme. Thefact that certain definite laws are revealed in the enormous numberof observations made of crystalline forms has led to the convictionthat the geometrical and physical properties of a crystalline materialare absolutely characteristic, and are, consequently, functions of thechemical composition, constitution, and configuration of the sub-stance: the discovery by Mitscherlich (1819) of the general factsof isomorphism, and that substances of the same chemical typeexhibit almost identical crystalline forms, has greatly strengthened,not, as was originally anticipated, weakened, this conviction.Pasteur’s law, that substances of enantiomorphous molecular con-figuration affect enantiomorphous crystalline structures, and thatthe crystal structures assumed by enantiomorphously related mole-cular configurations are themselves enantiomorphously related, hasbeen the subject of considerable controversy.3 The law may nowbe regarded its vindicated, and possesses importance in connexionwith the interdependence of crystalline form and chemical con-~ t i t u t i o n .~ Groth placed the subject of morphotropy on a soundbasis by pointing out that derivatives of benzene, which are not soclosely related as to be isomorphous, frequently exhibit markedquantitative resemblances in crystalline form ; this, again, indicatedthe existence of a function connecting crystalline form andchemical constitution.All these discoveries now form parts of thehistory of chemical crystallography, and have proved the basis ofimportant developments. No less importance attaches to severalmore recent extensions of our knowledge, which may now be brieflydiscussed.Chemische Krystallogrphie, Leipzig, 1806, c t seq.Wnlden, Bw., 1896, 29, 1692 ; A . , 1896, ii, 553 ; Kipping and Pope, Trans.,Pope and Harvey, Trans., 1901, 79, 828.1897, 71, 989 ; Barlow, Phil. Mag., 1897, [v], 43, 110CRYSTALLOGRAPHY. 263Tschermak has pointed out5 the frequent occurrence of astriking relation between the numerical proportions in which atomsof different elements are present in the molecule of a substanceand the nature of the symmetry presented by the crystalline form.He notes that compounds in the molecular formulz of which thenumbers 2 and 3 or 6 occur as denoting the nu;mbers of atoms ofvarious elements present, tend to crystallise in the rhombohedra1 orthe hexagonal system ; these crystalline systems are characterisedby the possession of axes of two- and three- or six-fold symmetry.As instances may be quoted the compounds of the following com-positions ; Fe203, FeCl,, A1C13,6H,0, Ag3SbS3, (C,H,),C*OH,SrCl,,GH,O, PI,, and CHI,.Similarly, those substances in themolecular formuh of which the number 4 occurs, but not thenumber 3, in a large proportion of cases crystallise in the tetragonalsystem ; this system possesses axes of two-fold and four-fold symmetry,but not of three-fold symmetry. As typical examples, the followingsubstances may be noted : ZrSiO,, G1S0,,4H20, (C,H,),Si, andC(CH,*OH),.I n the same way, compounds in the molecular com-positions of which the numbers 4 and 3 cccur tend to crystallisein the cubic system, this system possessing axes both of three- andof four-fold symmetry ; as illustrations the compositions of thefollowing cubic substances may be quoted : 3KF,ZrF,, Ag,PO,,As406, and K,S04,A1,S0,,24H,0. Tschermak’s conclusions are ofgreat significance as condemnatory of the view still occasionallyadvanced that the individuality of the atom is entirely lost whenit enters into molecular combination.The axial ratios by means of which the crystalline form of acrystalline substance are described are the ratios of some of thetranslations occurring in the homogeneous structure of the crystal.I n passing from a given substance to one isomorphous with it,the axial ratios in general change to a greater or less extent;but inasmuch as each set of axial ratios consists merely of ratios ofthe actual dimensions of the corresponding homogeneous structure,the comparison of the axial ratios of two isomorphous substancesdoes not reveal the change in dimensions which has accompaniedthepassage from one substance to the other.The three translations,the ratios alone of which are given by the axial ratios a : b : c, ingeneral all change during such a transition. More informationcan, however, be obtained by the consideration of a solid figure ofwhich the volume is the molecular volume, M , of the substance,and the iinear dimensions, x, I), and w, are in the ratio, a : b : c,of the axial ratios; the linear dimensions of the solid figure,measured in the three axial directions, indicate for a series ofTsch, Illi?~, Mitt., 1903, 22, 393264 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.isomorphous substances the absolute changes in magnitude ofcorresponding translations of the homogeneous structure commonto the substances which occur in passing from one member of theseries to another.I n either of the rectangular systems the values ofx, +b, and o, which are termed the ‘topic parameters’ or the‘ molecular distance ratios,’ are the following :$+,ac aFurther, x$w = M, and cc : b : c = x : $ : o.The molecular dis-tance ratios were introduced by F. Becke,6 and measure the absolutechanges in dimensions which a definite parallelopipedal molecularunit of the structure undergoes during the passage from onecrystalline substance to another or others isomorphous with it.They were applied by W. Muthmann7 to the investigation of thealkali permanganates, and from the differences between correspond-ing molecular distance ratios observed amongst the various saltsof the series, the conclusion was drawn that the unit of thecrystalline structure is composed of four chemical molecules. Theextension of this work to the alkali perchlorates, which are iso-morphous with. the permanganates, has furnished T. V.Barker 8with results which are not in agreement with Muthmann’:,conclusion. The way in which the axial ratios and the moleculardistance ratios are related is shown in the following table, whichgives the values for the alkali permanganates:a : b : c. M. x : q i : w .KMnO, ......... 0.7972 : 1 : 0.6491 58.526 3.8554 : 4-8360 : 3.1350RbMn0, ...... 0.8311 : 1 : 0.6662 63.228 4.0322 : 4.8517 : 3.2312CsMnO, ...... 0.8683 : 1 : 0.6853 70’042 4.2555 : 4.9009 : 3.3584NH,MnO, ... 0.8164 : 1 : 0.6584 62.126 3’9767 : 4.8711 : 3.2071It will be seen that whilst the axial ratios only measure therelative dimensions of translations in the homogeneous structurein the case of any one substance, because one axial dimension, thatof the axis b , is taken as unity, the molecular distance ratiosindicate, in addition, the relative dimensions of correspondingtranslations in the several members of an isomorphous series.The molecular distance ratios have been very systematicallyapplied by A; E.H. Tutton to the investigation of a long series ofsalts,S and the kind of information which they are capable ofyielding is well illustrated by this author’s numbers for the alkalisulphates and selenates.Sitzungsber. K. Akad. FViss. Wien, 1893, 30, 204.7 Zeitsch. Kryst. Min., 1894, 22, 497 ; A., 1894, ii, 181. * 16id., 1907, 43, 529.Trans., 1894, 65, 688 ; 1905, 87, 1183CRYSTALLOGRAPHY. 265x : J , : w .I<,SO, ........................ 3.88'10 : 3'8574 : 4.99644.0340 : 4.0039 : 5.23664.2187 : 4.1849 : 5.2366K,8e04 .......................4.0291 : 4.0068 : 5.1171Cs,SeO,. ....................... 4'3457 : 4.3040 : 5.6058Rh,SO, ........................cs,so, ........................Rh,Se04 .................... 4'1672 : 4'1315 : 5.3461The comparison of these figures shows that in passing from thesulphate or the selenate of one alkali metal to that of its neighbourin the periodic classification, the greatest change in the moleculardistance ratios is in o, which is measured in the vertical directionof the axis c ; the horizontally measured dimensions x and $Iexperience much less change. In passing from a sulphate to thecorresponding selenate, variation in the opposite sense is observed ;the values of x and $I change more than does that of o. Fromthese results Tutton concludes that the molecules of the alkalisulphates and selenates are so disposed in the crystal structure thatone atom of sulphur or selenium lies between two of the alkalimetal, and that all three are extended in the direction of thevertical axis c or of o.He claims that the further analysis ofhis results enables him to identify the particular point system ofthe 230 which characterises the crystal structure of these salts.In order that the notion of molecular distance ratios may besuccessfully applied to series of isomorphous substances, it isessential that the axial ratios used in their calculation should bethe ratios of corresponding translations in the crystal structure,cof a type common to the several members of the series; the knowncondition that the axial ratios of isomorphous substances approxi-mate closely to each other, in general renders it easy to ensure this.The molecular distance.ratios have, however, also been extensivelyapplied to morphotropically related substances, and here it isfrequently difficult to ensure that the axial ratios, and even theaxial directions, selected for the calculation, refer to correspondingdirections and dimensions in the homogeneous structures of theseveral members of the morphotropic series. The series of valuesstated in the following table are given by F. Slavik.10Crystal NH,I. NMe,I. NEt,I. NPr,I.ill ........... 57 -51 108.70 162.91 235-95x ............ 3.860 5.315 6-648 6.093I/I ........... 3'860 5.319 6'648 7.851w ............ 3 860 3.842 3.686 4.933system.Cubic. Tetragonal. Tetmgonsl. Orthorhombic.These numbers suggest that on replacing the four hydrogen atomsin ammonium iodide by four methyl or four ethyl groups, the mainlo ZeitsA. Kryst. Min., 1902, 36,'ZSS ; A., 1902, ii, 661266 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.change in dimensions of the crystal structure occurs in the direc-tions of the axes a and 6, in which the dimensions x and I) aremeasured; it is not, however, immediately evident that the values ofthe axial ratios, a : b : c, have been so chosen in the case of tetra-propylammonium iodide as to correspond with those used in thecase of the other members of the series. Another interesting seriesof alkyl derivatives, those of carbamide, has been worked out byG.Mez.11 In connexion with this question, it may be remarkedthat the practice, now very general, of publishing the moleculardistance ratios of isolated substances is useless, as the values onlypossess significance when compared with appropriately selectedmolecular distance ratios of related compounds.During the past twenty years Tutton has carried out a remark-able series of crystallographic measurements, the results of whichare, for the most part, published in the Transactions of theChemical Society. He has studied, in the majority of cases withthe aid of specially designed measuring instruments, the ortho-rhombic sulphates and selenates of potassium, rubidium, czesium,ammonium, and thallium, and many members of the series ofmonosymmetric double salts of the general compositionin which R is K, Rb, Cs, or NH,, M is Mg, Zn, Fey Ni, Co,Mn, Cu, or Cd, and D is S or Se.I n addition to the determinationof the crystalline form and the refraction constants, the coefficientsof expansion by heat, and other properties of these materials havebeen ascertained in the different principal directions of the crystalstructure. Amongst the principal conclusions which Tutton hasdrawn are that in each case the crystalline form and other proper-ties of the rubidium salt are intermediate between those of thecorresponding potassium and caesium salts; and that, in the caseof the double salts, the alkali metal exerts a predominant influencein determining the crystalline form; it is also shown that theeffect of introducing the ammonium radicle in place of a potassiumatom is nearly the same a,s that of similarly substituting a rubidiumfor a potassium atom.Tutton summarises his conclusions in ageneral law which states that,l2 in an isomorphous series in thestrictest sense, where the interchangeable elements belong to thesame family group of the periodic classification, the whole of theproperties of the crystals, morphological, optical, thermal, andphysical, in general are functions of the atomic weights of theseelements ; the sulphates and selenates of potassium, rubidium, andcaesium, of which the molecular distance ratios are quoted on p. 265,l1 Zeitsch. h-ryst. Men., 1902, 35, 242 ; A., 1902, i, 86.Proc.Boy. Soc., 1907, 79 A 381 ; A., 1907, ii, 688.RM(DO,),,6H@CRYSTALLOGRAPHY. 267belong to such a series, which, for the purpose of distinguishing thecloseness of the relations connecting its several members, is termeda (( eutropic series.” Thallium sulphate and selenate and ammoniumsulphate are only isomorphous with the previously mentionedeutropically related salts in a less rigid sense; this may be expressedby saying that thallium and ammonium are capable of changingplaces with potassium, rubidium, and czsium without alteringthe crystal system and without causing angular and structuralchanges of much greater magnitude than those produced by theinterchange of members of the same family group of elements. Anisomorphous series, in this wider sense, is defined as one the membersof which bear some definite chemical analogy and crystallise accord-ing to the same system and in the same class of that system, anddevelop the same forms inclined a t angles which only differ by afew degrees, rarely exceeding 3O. A eutropic series is one in whichthese small angular differences, and also the structural and physicalproperties of the crystals, obey the law of progression according tothe atomic weights of the interchangeable elements which give riseto the series and which belong to the same family group.Thusthallium sulphate and selenate and ammonium sulphate belong tothe isomorphous orthorhombic series, R,( S,Se)O,, whilst the sul-phates and selenates of potassium, rubidium, and caesium belong,not only to this isomorphous series, but also to the more exclusiveeutropic series included within it.The intimate relationship thusexhibited between potassium, rubidium, and caesium is of similarnature to that expressed by associating these three metals togetheras one Dobereiner triad in the periodic classification. Two generalpropositions, which could not previously be substantiated, areestablished by Tutton’s work. First, that goniometric measurementscan be made on carefully prepared materials of high purity, whichpossess a degree of accuracy comparable with that of atomic weightdeterminations. Secondly, proof is repeatedly found that the sub-stitution of one particular element by another produces a quantita-tively similar change in dimensions of the crystal structure, inwhatever salt the substitution is made; this result constitutes a greatadvance, because it shows that each atom entering into a crystallinestructure produces a definite and constant crystallographic effect,and indeed indicates the mode in which attempts should be madeto define that effect as a constant of the element concerned.The need for some distinction, such as that drawn by Tuttonbetween a eutropic and an isomorphous series, has also been recog-nised by T. V.Barker,l3 who has investigated the mode in whichl3 Trccns., 1906, 89, 1143 ; Jfi7~. Hug., 1307, 14, 235 ; 1908, 15, 42 ; A . , 1907,ii, 240 ; 1908, ii, 366268 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.substances crystallise from solution upon surfaces consistingof crystalline plates of other materials. T'he crystals whichseparate from the solution are in many cases found to assumea definite orientation with respect to principal crystallographicdirections in the crystalline surface upon which they form; theone substance is then said to form parallel growths upon the other.Examination of this property, that of forming solid solutions, anda number of others, as exhibited by the cubic cyanides and halogensalts of ammonium and the alkali metals has led Barker to classifythese compounds in two " isostructural " groups, the memberswithin either of which are especially closely related to each other.It is concluded that no direct connexion exists between the forma-tion of parallel growths and of solid solutions, although the twoproperties are favoured by the same factor, namely, similarity ofmolecular volume.Attention may now be directed to a mode of treating the secondkind of crystallo-chemical problem distinguished earlier in theReport, which offers a systematic scheme for the quantitativecorrelation of crystallographic facts of chemical importance, anddefines the relation subsisting between crystalline form andchemical composition, constitution, and configuration.W. Barlowand W. J. Pope 14 have adopted, for motives of convenience, a methodof regarding the whole of the volume occupied by a crystallinestructure as partitioned out into polyhedra, which lie packed togetherin such a manner as to fill the whole of that volume without inter-stices.The polyhedra can be so selected that each represents thehabitat of one component atom of the material, and are termedthe spheres of atomic influence of the constituent atoms. Up tothis point no assumption is made other than that clearly indicatedby the results of crystallographic measurements, namely, that eachatom present in a crystalline structure exerts a distinct morpho-logical effect--or, what is the same thing, appropriates a certaindefinite volume. The assumption is next made that the crystallinestructure, which is resolvable into individual molecules and ulti-mately into individual atoms, exists as such by reason of equili-brium set up between opposing attractive and repulsive forcesoperative between the component atoms, and that this equili-brium results in the polyhedra representing the spheres of atomicinfluence assuming shapes which are as nearly as possible spherical.The application of the new method of treatment and the assumptiondefined are shown to bring immediately into quantitative corre-spondence a great variety of crystallographic data which could notTrans., 1906, 89, 1675 ; 1907, 92, 1150 ; 1908, 93, 1528CRYSTALLOGRAPHY.269previously be interpreted, and to lead to noteworthy conclusionsrespecting valency and chemical constitution, which can be, andhave since been in part, verified by purely chemical methods.In harmony with the assumption that the spheres of predominantatomic influence tend towards sphericity, the polyhedra thus arriveda t may be regarded as derived by compression of a close-packedassemblage of deformable incompressible elastic spheres, the com-pression sufficing for the practical extinction of the interstitialspace.When such an assemblage is released from pressure it isevident that in place of polyhedra, the shapes of which approximateas closely as possible to the spherical, closely-packed spheres are pre-sented; the distances between the sphere centres can be sub-stantially in the same ratios as the distances between the centres ofthe corresponding polyhedra in the unexpanded mass, and theequilibrium condition of maximum sphericity of the polyhedra willbe represented in the expanded mass of spheres by the existenceof the maximum number of contacts between spheres.The wholemethod of treating the primary assumption thus resolves itself intofinding close-packed assemblages of spheres of various sizes repre-senting by their relative volumes the spheres of influence of thecomponent atoms of any particular crystalline structure.For illustrative purposes, the comparatively simple case presentedby the crystalline elements may be presented. I f the atoms of anelement are all similar, and if their grouping into molecular com-plexes does not appreciably affect the relationship existing betweenneighbouring atoms, the crystalline form assumed by the elementshould have the symmetry and dimensions of the closest-packedassemblage of equal spheres. There are, however, two such closest-packed assemblages,l5 one of cubic symmetry, in which thesymmetry defines all the dimensions, and the other of hexa-gonal symmetry, in which the ratio of a horizontal translation,a, to a vertical translation, c, is a:c=l:1*6330 or 1 :1'4142.Of the crystalline elements, 50 per cent.are cubic and 35 per cent.are hexagonal, and, so far as data have been collected, the axialratios of the hexagonal elements approximate to the values of a : cquoted above.Suppose, however, that some complicating factor is operative indetermining the crystalline form of the element, such, for instance,as a molecular aggregation holding certain sets of atoms togetherin positions of some restraint; this should disturb the simplicity ofthe relation indicated above, and should result in the crystallineform departing to a greater or lesser extent from the closest-packedl5 Trans., 1907, 91, 1159270 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.cubic or hexagonal arrangement of equal spheres.Those elementswhich are neither cubic nor hexagonal would therefore be expectedto assume crystalline forms approximating closely to the cubic orhexagonal arrangement indicated. An inspection of the geometricaldata for the few elements which are neither cubic nor hexagonalshows that they are all so closely allied to the forms indicated thata very slight distortion would make them wholly cubic or hexagonal.It is further very significant that those elements which exhibitcharacteristics usually associated with particular types of molecularaggregation, such as colour, existence in allotropic modifications,etc., are the ones which differ niost markedly in crystallineform from the simple cubic and hexagonal structures indicated;thus, whilst ordinary phosphorus and diamond are cubic, red phos-phorus and graphite are respectively orthorhombic and mono-symmetric. Consideration of the crystalline structure and thetwinning of diamond, together with its relations to graphite, haveled W.J. Sollas l6 to suggest the cubic closest-packed arrangementof equal spheres as representing the crystal structure of diamond,and the tetrahedrally arranged groups of four spheres, into whichthat arrangement is homogeneously partitionable, as representingthe molecules of this allotropic form of carbon.17On turning to the binary compounds, such as NaC1, KI, AgI, andZnO, a further advance is indicated. The molecules of nearly allbinary compounds consist of two atoms of undoubtedly equalvalency, and of these 68.5 per cent.are cubic and 19.5 per cent.hexagonal, the axial ratios of the latter in every case approximatingvery closely to the theoretical value of a : c = 1 : 1.6330, indicatedabove. Whilst, however, the crystal forms of the cubic and hexa-gonal elements nearly all belong, so far as is known, to the holohedralcrystal classes, those of the binary compounds belong to the lesssymmetrical hemihedral, tetartohedral, or hemimorphous classes ofthe two systems. By allocating, in the cubic or hexagonal closest-packed assemblage above referred to, one-half of the polyhedralcells, appropriately selected, to the one kind of component atoms,and the remainder to the other element present in the compound,the cubic or hexagonal crystalline form, with its appropriate corre-sponding hemi- or tetarto-hedrism or hemimorphism, can be preciselyimitated.Other peculiarities of the crystalline structure, such asthe existence of gliding planes in the alkali halogen compounds andthe interconversion of the cubic and hexagonal modifications ofsilver iodide, can also be exactly simulated. Each of the assemblagesl6 Proc. Boy. Xoc., 1901, 67, 493.I7 Compare also Sci. Proc. Roy. UuJZ. Soc:., 1897, 8, 542, and Tram., 1906, 89,1741CRYSTALLOGRAPHY. 271thus devised can be geometrically partitioned into similar unitscomposed of two adjoining spheres of atomic influence, one of eachelement; these, it may be premised, represent the molecules of thebinary compound as they occur in the crystal structure.The close imitation of the crystalline behaviour of the binarycompounds by the closest-packed assemblages of polyhedra or spheres,briefly described above, points to a conclusion of a novel kind, the cor-rectness of which has been repeatedly confirmed in the course of thework now under review. The conclusion is that the volumes appro-priated by the polyhedra representing the spheres of atomic influencein any crystalline structure are approximately proportional to thenumbers representing the valencies of the respective elements con-cerned.Further investigation seems to show that in every casehitherto studied the valency thus exhibited by an element is thelowest which its chemical behaviour assigns to it; this valency isconveniently distinguished as the fundamental valency of theelement. The crystalline forms of the substances CsI,, Tl13, andCsI,, for example, are all in accordance with the view that theconstituent elements are fundamentally univalent. The law thusenunciated is termed the law of valency volumes.It is not indicated that the volumes of the spheres of atomicinfluence are rigidly proportional to the whole numbers repre-senting the fundamental valencies ; on the contrary, the volumesonly approximate to the whole number ratios, and an analysis ofthe data for the crystalline trihalides of the alkali metals showsthat throughout the measured series of sixteen salts, the volumeof the sphere of atomic influence increases slightly in passing frompotassium to rubidium to czsium, and from chlorine to bromine toiodine.The sphere of atomic influence of thallium in thallic iodideis almost identical in volume with that of rubidium in rubidium tri-iodide. The indication thus obtained of the invariability of magni-tude of the sphere of atomic influence of any particular elementis in complete agreement with the general result drawn fromTutton’s work, namely, that the dimensional influence exercised onthe crystal structure by a particular atom is constant. The closeapproximation to identity between the volumes of the spheres ofatomic influence of rubidium and thallium in the salts TlI, andRbI, is striking in view of Tutton’s demonstration that rubidiumand thallous sulphates have almost the same crystallographic dimen-sions.18The law of valency volumes noted above indicates that a veryclose relationship exists between the crystalline form of a substanceand the fundamental valencies of the component elements.It shouldl8 h o e . Roy. Soc., 1907, 79, A, 351 ; A., 1907, ii, 688272 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.consequently be possible to elucidate by its aid all those morphotropicsimilarities between the crystal forms of substances of allied con-stitutions which in the past have been a t once so striking and somysterious; this can, indeed, be done by substituting, in the cal-culation of the molecular distance ratio;, the molecular volume bythe sum of the valencies of the atoms constituting the molecule.By this means a method is obtained of comparing the dimensionsof translations in the crystalline structures of a series of morpho-tropically related substances, on the assumption that, under suchconditions, each atom throughout the series reserves for its ownoccupation a volume proportional to the number representing itsfundamental valency.The sum of the valencies of the atoms com-posing the molecule, the so-called “ valency volume,” being W , therequired translation ratios, or the equivalence parameters,” x, y,and z, are given in the rectangular crystalline systems by :x=$?, 3 - F -..=37The further relations hold that xyz = W and x : y : z =a : b : c.If morphotropic relationships are correlated by means of theequivalence parameters, it is evident that strong confirmation ofthe truth of the law of valency volumes is obtained. The study ofa number of cases shows this prediction to be amply verified,lg andthe following may be quoted in order to show the nature of therelation established.d-Camphoric anhydride, Cl0Hl4O3, and the additive compound ofd-camphoric acid with acetone, C,,H,,0,,+(CH,)2C0, are bothorthorhombic, and are closely related through their axial ratios ;the latter values and those of the corresponding equivalence para-meters are stated below :w. a : b : c.2 : y : z .d-C,,H,,O, .. . . . . . . . . . .. .d-Cl,H,,O,, $Mr,CO . . .The axial ratios show that the whole of the morphological effectof introducing the elements of H,O,~Me,CO into the moleculeof camphoric anhydride is exerted in the direction of the axis a ;the equivalence parameters show that the magnitude of this effectis proportional to the sum of the valencies of the increment thusintroduced. Bther instances of the kind are found amongst thehumite mineralsF0 and the substances related to ‘‘ saccharin.” F. M.Jaeger has also demonstrated 21 that predictions concerning the60741’0011 : 1 : 1‘72701.2386 : 1 : 1‘71723-265 : 3’262 : 5.6334.043 : 3.265 : 5.606l9 T r a m , 1906, 89, 1680.21 B i d . , 1008, 93, 517.2o Ibid., 1686 ; 1908, 93, 1559CRYSTALLOGRAPHY.273existence of morphotropic relations, based on the considerations justput forward, are verified in actual practice.Whilst a large mass of results such as the above definitely provethe truth of the new crystallographic law of valency volumes, it isinteresting that independent evidence establishing a relationbetween valency and volume has recently been brought forwardfrom quite another source. G. Le Bas has shown22 that the mole-cular volumes of a series of normal paraffins in the liquid stateat the melting point can only be interpreted on the assumption thatthe atomic volume of carbon is four times that of hydrogen; themelting points are approximately equal fractions of the criticaltemperatures, and Le Bas has also demonstrated that the samerelation holds in a series of paraffins when examined at some otherseries of corresponding temperatures.The molecular volumes, M, ofthe normal paraffins containing from 11 to 35, or n, carbon atoms inthe molecule, in the liquid state a t the melting point, are given bythe expression :M = 2.970(6n + 2 ) = 2.970 W :W being the valencs volume; the quantity 2.970 represents theatomic volume of hydrogen in the hydrocarbons under the condi-tions specified. Somewhat similar results have been obtained byI. Traube,23 as regards the proportionality, not only of valency andatomic volume, but also of valency and atomic refraction. I n alater paper,24 Le Bas extends his conclusions to olefinic andacetylenic hydrocarbons.The definite demonstration which Le Bas has furnished of therelation between the atomic volumes of hydrogen and carbon inliquid hydrocarbons and the valency of these two elements is ofimportance in connexion with the nature of liquids; it indicatesthat the principle of close packing of the molecular aggregates stillapplies in liquids, the,main difference between the liquid and thecrystalline states being probably that, whiIst both are close-packedconditions, the latter is a structurally homogeneous state, and theformer is not.Further, since in liquids the valency volume is onlyproportional to the molecular volume under corresponding condi-tions, it is suggested that throughout series of crystalline substancesthe molecular volumes would be proportional to the valency volumesif the former values could be determined at corresponding tem-peratures.No means of defining corresponding temperatures, inthe sense of the van der Waals gas equation, for crystalline sub-stances, are as yet available, but in the light of the results now22 Trans., 1907, 91, 112 ; Phil. Mag., 1907, [vi], 14, 324 ; A., 1907, ii, 754.23 Ber., 1907, 40, 723 ; A., 1907, ii, 205.24 Phil. Mag., 1908, [vi], 16, 60 ; A , , ii, 667.REP.-VOL. V. 274 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.reviewed it would seem likely that, measured at corresponding tem-peratures, the molecular distance ratios would be directly propor-tional to the equivalence parameters throughout series of crystallinesubstances. This probability seems likely to render unfruitfulattempts to ascertain the nature of specific crystal structures bycorrelating the crystalline form, the atomic volumes of the componentelements, and the changes in molecular volume which accompanypolymorphous changes in the materials concerned.Much work ofa very suggestive character has, however, been done on this subjectby W. J. sol la^.^^As indicating the probability of the transient existence in liquidsthroughout molecularly large tracts of homogeneously arrangedaggregates of molecules, the work of 0. Lehmann, D. Vorlander,F. M. Jaeger, and others on the so-called ‘‘ liquid crystals” maybe quoted. A number of substances, many of which exhibit closeconstitutional relationships, are now known which throughoutdefinite ranges of temperature exist in liquid phases exhibitingdouble refraction and other behaviour ordinarily attributed tocrystalline structures ; in certain cases the occurrence of dimorphismand of sudden changes of optical orientation can be distinctlyobserved.As has been remarked above, the partitioning of a crystal struc-ture into close-fitting polyhedral units, each of which representsthe sphere of influence of a constituent atom, is equivalent to, andis conveniently replaced by, the building up of a system of spheresin contact with each other.The equilibrium condition-that thepolyhedra shall assume shapes as nearly spherical as possible-isimitated by arranging the spheres in close-packing; that is to say,so that the assemblage presents the maximum number of contactsbetween spheres.I f the assemblage of spheres is compressed fromall sides so as to eliminate the interstices, each sphere becomesflattened to polyhedral shape.26The construction of a model which shall represent in dimensionsand structure the crystalline form of any given substance conse-quently resolves itself into the construction of a close-packedassemblage of spheres of volumes proportional to the fundamentalvalencies of the several elements contained in the substance, theproportion in which the various kinds of spheres are used beinggiven by the molecular composition. The assemblage thus producedmust be characterised by symmetry and translations identical withthose of the crystalline substance, and must be capable of partitioninto units, each of which represents in composition, constitution,and configuration a chemical molecule.These conditions narrowly25 Proc. Roy. SOC., 1898, 63, 291. 26 Trans., 1907, 91, 1157CRYSTALLOGRAPHY. 275limit the possible assemblages of spheres which may be presentedfor any particular case.The investigation of the case of benzene in the manner justindicated has led to the production of a model which is in accord-ance with the crystalline form of the hydrocarbon, and which maybe partitioned into units, each of the composition C,H,, and posesessing a definite configuration of a novel character.27 The modelof the benzene molecule thus derived accords with the generalbehaviour of the hydrocarbon, and possesses certain advantages overthe older models; thus it shows how the ortho-para law of substitu-tion operates, it indicates why optical activity is not exhibited bycertain of the di-derivatives of benzene, and offers a very simplemechanism representing the production of benzene or its homologuesfrom the corresponding acetylene derivatives.28 In similar mannermodels representing naphthalene and anthracene have been devised.It should, perhaps, be emphasised that in constructing close-packedassemblages representing crystalline benzene or any other substanceno suggestion is made that the component atoms are packed closelytogether; the close-packing of the spheres of atomic influencemerely means that the whole of the space occupied by a crystallinematerial is occupied by the constituent atoms in the sense that anypoint chosen within it is subject to the predominant influence of someone atom and that each atom thus influences a domain which isapproximately spherical in shape.Two important questions relating to substitution and multi-valency are conveniently considered in connexion with close-packed assemblages of the same or different sizes.Firstly, if, in ahomogeneous and close-packed assemblage of spheres, homogeneouslysituated spheres each of volume m are each replaced by a group of twoor more spheres having the total volume m, a slight distortion ofthe assemblage, which does not change the grouping of the un-changed spheres, suffices for the restoration of close-packing.Thisis termed the first geometrical property of close-packed homogeneousassemblages, and indicates that in the assemblages representing thecrystal structures of substances of some molecular complexity, onekind of sphere of a certain magnitude may be replaced by severalothers of the same total magnitude, or vice versa, without neces-sitating any considerable rearrangement or " remarshalling " of theassemblage as a whole. It indicates, for instance, that if all thenitrogen spheres, each of volume 3, in the assemblage representingtriphenylamine are replaced, each by three spheres of volume 1,'77 T~mzs., 1906, 89, 1692.28 Compare J. 13. Tingle and F. C . Blanck, J. A7ner. Chenz. Soc., 1908, 30,1596 ; A., i, 893.T 276 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.representing hydrogen, close-packing can be restored to the modifiedassemblage by a slight distortion, which leaves the groups of spheresrepresenting the phenyl radicles of unchanged configuration.Thesecond point of importance arises in connexion with the so-calledsecond geometrical property of close-packed homogeneous assemblages.This states that if, in such an assemblage as that of triphenylamine,the nitrogen spheres of volume 3 are each replaced by a carbonsphere of volume 4, close-packing can only be restored by distortionunaccompanied by remarshalling, if for each extra unit of volumethus added yet another extra unit of volume is introduced. So thatif the nitrogen spheres are substituted by carbon spheres as justsupposed, the restoration of the close-packing can only be broughtabout without profound rearrangement of the assemblage by intro-ducing a sphere of volume 1 with each carbon sphere; the relationsbetween the assemblages and the molecular compositions of tri-phenylamine and triphenylmethane are thus indicated.The modesin which substitutions, such as those of iN by iCH, or of OH by *OH,*NH,, *CH,, or GN, occur whilst some large radicle in the assem-blage preserves its original configuration are thus elucidated.The second geometrical property has, however, still wider applica-tions. The replacement of the nitrogen sphere of volume 3 by thecarbon sphere of volume 4 is, under the conditions explained, geo-metrically equivalent to introducing with it another sphere ofvolume 1, such as a hydrogen sphere; and by the same argumentas before, it is necessary, in order to restore close-packing withoutremarshalling, to associate yet another sphere of volume 1 with thenitrogen sphere.By selecting a chlorine sphere of unit volume forthe latter purpose a mode is indicated by which the assemblage forammonia or tin amine can be converted into ammonium chloride orone of its alkyl derivatives, and generally by which the valency ofan element can be caused to increase by two, or a whole multiple oftwo, units.29 Further, the application of the second geometrical pro-perty elucidates immediately the well-known relationship betweenthe crystal forms of calcite, CaCO,, and sodium nitrate,NaNO,.The crystalline structures of those two substances arehighly characteristic and present striking peculiarities ; theyare of identical symmetry and of almost the same relative dimen-sions, and yet no correspondence exists between calcium and carbonon the one hand, and sodium and nitrogen on the other. The secondgeometrical property indicates, however, that if the nitrogen spheresof volume 3 present in the sodium nitrate assemblage are replacedeach by a carbon sphere of volume 4, an extra unit of volume mustbe introduced for each sphere so substituted in order that close-‘Ly Tyans., 1907, 91, 1204CRYSTALLOGRAPHY. 277packing may be re-established without remarshalling ; the similaritybetween the two crystalline substances indicates that they have thesame marshalling, and the extra unit of volume thus called for ip1introduced by, a t the same time, replacing each sodium sphere ofvolume 1 by a calcium sphere of volume 2.Incidentally it isindicated that the molecules of calcium carbonate and sodium nitratehave the same configuration. The crystalline structures of thesetwo rhombohedra1 substances have been worked out in detailto asalso have those of the similarly related but orthorhombic aragonite,CaCO,, and potassium nitrate. Several other morphotropic rela-tionships of similar kind have been recently discussed by F. M.Jaeger with the aid of the equivalence parameter^.^^Comparatively few cases of morphotropic relationship between theseveral polymorphous modifications of any particular substance havebeen recorded, but by examining the crystalline forms of such com-pounds; under the aspects suggested by the new mode of regardingcrystal structure, numerous analogies are revealed.The mode ofoccurrence of polymorphism is best illustrated by aid of a simpleexample. The cubic and hexagonal crystal structures of silveriodide have been imitated by the construction of cubic and hexa-gonal closest-packed systems of spheres of the same size; in theseconstructions equal numbers of triangularly-arranged layers ofspheres of the same sizes are packed together in two alternativemanners. The one kind of layer contains three times as manyspheres representing silver atomic domains as of those representingiodine; the other kind of layer contains three times as manyiodine as silver spheres.The arrangement of equal numbers ofthese two kinds of layers which gives the cubic closest-packedassemblage is one in which the layers are so stacked one uponthe other that the fourth layer comes exactly over the first, thefifth over the second, and so on; in the hexagollal arrangementthe layers are so stacked that the third lies over the first, thefourth over the second, and so on. The conversion of the cubicmodification into the hexagonal one is equivalent to convertingthe cubic assemblage into the hexagonal one by sliding each thirdlayer in the stack into the appropriate position. Both assemblagesare capable of geometrical partition into identical units represent-ing the molecule AgI, and so may be regarded merely as differentmodes of packing together identical molecular units.I f this iscorrect, and if polymorphously related crystal structures are to beregarded as made up of identical layers packed together in alterna-tive ways, it should, in general, be possible to determine identicalsets of translations in the several such crystal structures. This selec-3d Trans., 1908, 93, 1528. 31 Ibid., 517278 ANNUAL REPORTS ON THE PROGRESS OF CHENIISTRY.tion is obviously possible in the cubic and hexagonal assemblagespresented for silver iodide, because the horizontal translations withinthe layers are the same in both cases, and the vertical translations,or the distances between the planes of sphere centres in two adjoin-ing layers, are also the same.The morphotropic relation thusindicated, namely, the possibility of calculating the axial ratiosof one substance from those of a polymorphously related substanceby some simple change in the axial directions, has been discoveredin a number of instances. Thus, by merely changing the axialdirections in the hemimorphously rhombohedral silver antimonysulphide, Ag,SbS,, for which Miers gives the values u : c = 1 : 0.7892,axial ratios are obtained of the values a : b : c = 1.9007 : 1 : 1.0971,p = 90° ; these correspond closely with the axial ratios, a : b : c =1-9465 : 1 : 1-0973, P = 90°, given for the monosymmetric mineralof the same composition.32 Cases of isopolymorphism may be dealtwith in the same way.Thus the transposition of the axial ratios,a : c = 1 : 0.8276, of the rhombohedral sodium nitrate yields theaxial ratios, a : b : c = 1.7320 : 1 : 0.7151, values almost identical withthose stated by Jaeger 33 for the orthorhombic rubidium nitrate,namely, u : b : c = 1.7366 : 1 : 0.7106.The treatment of crystal structures as close-packed assemblagesand the interpretation of the crystal measurements by the aid ofthe equivalence parameters suggests wide developments of the wholesubject of morphotropic relationships; one of these has been fol-lowed up with success. I n the assemblage representing crystallinebenzene and in those for the simple benzene derivatives, the carbonspheres are found arranged in columns; each joint in the latterconsists of three carbon spheres arranged in triangular contact.34The presence of these columns keeps the translation measuredin their direction the same in the various assemblages inwhich they occur; in benzene itself the value of thistranslation is that of the equivalence parameter a=2.780.Itwould consequently be expected that this value should occuramongst the equivalence parameters of any benzene derivative theassemblage of which contains the columns remarked. On calcu-lating the equivalence parameters of twelve derivatives of picricand styphnic acids, it has been found that one of the three equival-ence parameters in each case assumes a value closely approaching t othe vaIue z=2.780, for benzene.35 The prediction as t o theexistence of this particular morphotropic relation has thus beenamply verified, and an indication has been obtained that the32 Trans., 1908, 93, 1531.34 Trans., 1906, 89, 1693.35 G. Jerusalem and W, J. Pope, Proc. Roy. Sot. 1908 80, A, 557 ; A . ii, 674.33 Zcifsch. Kryst. Miv., 1907, 43, 588Cli I' ST A L J,O GR A PH Y. 279occurrence in the crystal structure of the columns of carbon spheresreferred to is a general property of benzene derivatives. Theinterpretation to be placed upon the general occurrence of thecolumns is that, in the passage from crystalline benzene to somecrystalline derivative, the columns of carbon spheres move apartto a sufficient extent to allow of the introduction of the substitut-ing groups, the increase of volume thus rendered available foroccupation by spheres of atomic influence being proportional tothe increase in valency volume caused by the substitution.The fixity of arrangement of part of the crystalline structureduring changes amongst comparatively small substituting groupsin large molecular complexes, as well its the operation of the firstand second geometrical properties which are observed in the caseof the above substances, is also well exemplified by the nearapproximation to identity of the axial ratios of dibenzyl, stilbene,tolane, and azobenzene.36 The precision with which the changes ofthe equivalence parameters accord with the changes of compositionin such series of related substances as the above proves definitelythat the volumes of the spheres of atomic influence in any given com-pound are approximately proportional to the fundamental valenciesof the elements concerned. This also involves the conclusion thatwhen a considerable increase of molecular volume attends the sub-stitution of one atom by another of the same valency, as, forexample, the replacement of hydrogen by chlorine in benzene, eachcomponent sphere of atomic influence is proportionally enlarged ;the volumes appropriated in the chlorobenzenes by hydrogen,chlorine, and carbon still stand in the ratio of their respectivefundamental valencies, although those for hydrogen and carbonare actually greater than in benzene itself.WILLIAM JACKSON POPE.313 Zirngiel)I, Zc%ihc'). Kryst. Mi7t.., 1902, 36, 117 ; A . , 1902, ii, 496

ISSN:0365-6217    

DOI:10.1039/AR9080500258

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

INDEX OF AUTHORS’ NAMES.Abderhalden, E. , 170.Abegg, R., 24.Abel, E., 49.Acheson, E. G., 58.Ackermann, E., 204.Acree, S. F., 83, 184.Adams, G. O., 197.Adeney, W. E., 197.Allmand, A. J., 45.Alway, F. J., 250.Andersen, A. C., 185.Anschiitz, R., 135.Antoni, W., 206.Antropoff, A. von, 48.Archbutt, S. L., 187.Armstrong, H. E., 21, 23.Arthur, W,, 191.Astruc, H., 207.Atkins, W. R. G., 208.Aumer, J. , 188.Austin, P. C., 120.Autenrieth, W., 193.Auwers, I<., 144, 145.Baborovsky’, J. , 48.Baddiley, J., 112.Badische Anilin- & Soda-Fabrik, 67.Baglioni, S., 256.Bain, J. W., 188.Baker, H. B., 38.Baker, J. L., 208.Balke, C. W., 51, 69.Baly, E. C. C., 83, 132, 133.Bamberger, E., 112.Bancroft, W. D., 11.Bang, I., 217, 219.Rarberio, M., 185.Barger, G., 158, 172.Barker, T.V., 264, 267.Barlow, W., 268, ~t scp.Barr, G., 198.Barr, W. M., 69.Rartelt, K., 101.Baskoff, A,, 241.Raubigny, H., 185.Bauer, I<., 238.Bauer, O., 71.Baume, G., 38.Baur, E., 252.Baxter, G. P., 38.Bay, I., 201.Beans, H. T., 195.Beck, P., 188.Reeker, W., 70.Behrend, R., 87.Belloni, E., 200.Bellucci, I., 56.Eemberg, J. P., 89.Bemmelen, J. M. van, 65.Benda, L., 174.Bennett, U. T., 204.Berchem, O., 196.Bereza, S., 85.Berg, P., 90.Bergmann, von, 208.Berkeley, Earl of, 15, 16.Berl, E., 89.Bertheim, A., 174.Bettel, W., 183.Bevan, E. J., 205.Beyer, F. B., 193.Beyerinck, M. W., 242.Bezdzik, A., 158.Bienenfeld, B., 216.Biginelli, P., 209.Biltz, H., 40.Biltz, W., 60.Biquard, R., 62.Birckenbach, L., 38.Birschel, E., 128.Blacher, C.J., 197.Blackman, P., 200.Blair, A. A., 191.Blanck, F. C., 274, 275.Bloch, A., 204.Bloch, E., 68.Bloch, I., 58.Eloch, I,., 68282 INDEX OF AUTHORS’ NAMES.Blume, G., 201.Bodmer, E., 161.Bodtker, E., 81.BBeselren, J., 81.Bokman, G., 55.Boters, O., 113.Bogert. 11. T., 118.Bollenbach, H., 182, 190, 201.Bolton, W. von, 44.Bone, W. A., 84, 196.BoupB, W. von, 89.Bordas, F., 182.Rorelli, V., 57.Borgmann, I., 97.Borgo, A., 53.Bornemann, K., 43.Borsche, W., 119, 120, 143.Bose, E., 105.Bossuet, R., 42.Bourguignon, A., 75.Bourion, F., 198.Bousfield, W. R., 196.Bouveault, L,, 102.Bowen, J. L., 204Brand, J., 192.Rrandt, L., 189.Brauner, B., 36.Bray, W.C., 181.Brdlik, V., 254.Bredeniann, G., 244.Brieger, L., 208.Briggs, J. P , 205.BriIier, E., 41, 50.Brislre, F. J., 45.Hrodie, T. G., 225.Brown, C. W., 246.Brown, H. T., 253.Brown, P. E., 246.Brown, T. G., 226.Browne, A. W., 66.Rruhl, J. W., 100.Brunck, O., 190.Bruni, G., 53.Brunner, H., 186.Bruschi, D., 253.Bryan, H., 206.Buchner, E., 121.Burrows, H., 196.Burton, C. V., 16.Busch, M., 80, 201.Bush, G. C., 179.Buttle, B. H., 186.Cain, J. C., 112, 136, 137, 138.Calcagni, G., 68.Calhane, D. F., 181.Callendar, H. L., 18.Cctmbi, L., 56.Camiola, G., 246.Campbell, E. D., 191,Cantoni, H., 190.Carleton, P. W., 124.Carlson, B., 186.Caron, H., 181, 183.Carpiaus, E., 254.Carrasco, O., 200.Cathcart, E.P., 226.Cazeneuve, P., 191.Cenni, G., 195.Cesnris, P. de, 56.Chace, E. M., 204.Chalker, W. C., 54.Chnpmnn, A. C., 207.Charpy, G., 41.Charrier, G., 143.Chattaway, F. D., 139.Chemische Fabrik Griesheiin-Elektron,Chemische Fabrik vorin. Goldenberg,Chesneau, G., 187.Chick, Miss P., 85.Chouchak, D., 257.Christensen, P., 187.Ciamician, G., 92.Clark, H. W., 197.Clark, R. H., 81.Clarke, L., 185.Clarke, R. W. L., 81.Classen, A., 193.Clayton, A., 147, 149.Clough, G. W., 110.Cobb, P. H., 90.Coca, 237.Cohen, E., 17, 40, 194.Cohen, J. B., 112.Coleman, L. C., 244.Colnlan, H. G., 201.Colman, J., 115.Colson, A., 40, 54.Coninielin, J. W., 17.Cone, L. H., 171.Cook, T., 200.Copaux, H., 46.Coppadoro, A., 51.Cordier, V.von, 201.Corradi, R., 201.Courtauld, R. M., 197.Coward, H. F., 84.Cramer, W., 222, 224, 235.Crewdson, Miss N. S., 78.Crorikes, Sir W., 71, 195.Cross, C. F., 205.Cullis, Miss W. C., 225.Curtius, T., 96.Cushman, A. S., 62.Dskin, H. D., 87, 198.Damm, F., 44.D’Ans, J., 63.Darapsky, A., 96.Darbishire, F. V., 250.68.Geromont & Co., 207INDEX OF AUTHORS’ NAMES. 283Daufresne, M., 204.Decker, H., 126, 156, 168.Defacqz, E., 46, 193.Dehn, W. M., 198.Delbriick, I<. , 121.DelBpine, &I., 56, 183.Dengler, O., 164.Denham, H. G., 45, 56.DenigBs, G., 192, 199, 207.Dennis, L. M., 197.Dennstedt, M., 199, 200.Desamari, K., 124.De‘sch, C. H., 133, 189.Deuss, J.J. 13.. 177.Dieckmann, W., 82.Diels, O., 85.Dienstbach, O., 133.Dimroth, O., 133, 142.Dittrich, 31, , 192.Donan, J., 184.Dons, R. I<., 203.Dor6e, C., 231, 233.Dott, D. B., 191.Dreyer, L., 209.Drushel, W. A., 193.Duboin, A., 60.Duboux, M., 206, 207.Duke, W. W., 225.Dunant, G . , 168.Dungern, von, 237.Dunlap, E. E., 188.Dunstan, A. E., 91, 111.Dupont, E., 207.nurand, E., 41, 50.Dutoit, P., 206, 207.Duyk, M., 192.Ebler, E., 66, 181.Eclcardt, M., 144.Eddy, E. A., 82.Edgrir, E. C., 37.Edgar, G., 190, 193.Edwards, W. H . , 132.Eggink, R. G., 45.Einhorn, A., 85, 173.Emersnn, W. H., 203.Emmerich, F., 100.Engel, 216.Engels, P., 153.Epliraim, F., 43.Erdmann, H., 39, 60, 63.Erlxndsen, A., 230.Ernyci, E., 197.Euler, H.von, 137.Evans, Bliss C. de B., 35.Everatt, R. W., 105.Ewart, A. J., 252.Ewers, E., 202.Ewins, A. J., 158, 172.Fabris, U., 75.Falcke, V., 53.Falk, F., 239.Farbwerke vorni. Meister Lucius andBriining, 172.Favrel, G., 207.Faworsky, A. E., 97.Feilitzen, H. von, 254.Feist, I<., 169.Felser, H., 156.Fenton, H. J. H., 198.Fichter, F., 128.Fickewirth, G., 149.Fierz, H. E., 94, 95.Fillinger, F. von, 198.Finnemore, H., 173.Fischer, A., 195.Fischer, E., 110, 170, 1’71.Fischer, F., 49, 61.Fischer, O., 162.Fisher, K., 97, 98.Fitzgerald, E., 82.Fleig. C., 199, 204.Fletcher, F., 249.Fliirscheim, B. 113.Foerster, F., .67, 193, 194.Fokin, S., 203.Foote, H. W., 44, 54.Ford, J.S., 207, 208.Formlials, R., 191.Forster, M. O., 94, 95, 101.Fox, J. J., 147.Fraenckel, A . , 196.Fraenlrel, Tlr., 42.Frank, A., 206.Franzen, H., 197.Free, E. E., 191.Friedlander, P., 158.Friedrich, K., 42.Friend, J. N., 32, 64, 71.Fries, I<., 147, 149.Friihlich, H.. 244.Fromm, E., 178.Fiirth, G . V O I ~ , 219, 238.Fuld, E., 216.Funaro, R., 228.Gabriel, S., 114, 115.Gain, G . , 69.Galletlv, J. C., 65.Gallo. b., 195.Gardner, J. A., 231, 233.Gamier, L., 199.Ganbert, P., 63.Gawalowski, A., 196.Gmdar, Miss M., 177.Gebhard, N. L., 196.Geerligs, H. C . P., 202, 206.Gelhanr. J., 186.Geniniell, W., 187.Geriiez, D., 13.Gerum, J., 58, 76284 INDEX OF AUTHORS' NAMES.Gewin, J. W. A,, 217.Gibson, B. J.H., 252.Gillett, H. W., 194.Gilniour, R., 87.Gimingham, C. T., 245.Glikin, W., 231.Glover, W. H., 101, 102.Gotz, C., 111.Goldbaum, J. S., 195.Goldemann, J., 128.Goldschmidt, R. , 195.Golodetz, L., 198.Gomberg, M., 135.Gooch, F. A., 193.Gorsline, E. E., 81.Gortner, R. A., 175.Gottlieb, R., 226.Gowing-Scopes, L., 207.Grammling, F., 56.Grandmougin, E., 161.Grazia, S. de, 246.Green, A. G., 112, 184.Greenwood, H. C., 44.Grdgoire, A., 254.Gregory, A. W., 183, 190.Grossniann, H., 182, 190.Grube, K., 224.Grzeschik, T., 188.Guggenheim, M., 171.Gutbier, A., 38, 56.Guthrie, J. M., 207, 208.Gutmann, A., 177.Guttmann, A,, 45.Gyr, J., 83.Haakh, H., 107.Haber, F., 67.Hackspill, L., 42.Haeffner, K., 94.Haehn, H., 183.Hahn, A., 79.Haitinger, I,., 64.Halban, H. von, 109.Haldane, J.S., 221..Hall, A. ,D., 245, 255.Hammarsten, O., 217.Hamonet, J. L., 79.HBncu, V. H., 91, 200Hannig, E., 244.Hantzsch, A., 10, 133, 134, 136, 138,Hanus, J., 204.Harries, C. D., 93, 94, 99, 102.Harrison, T . W., 189, 203.Hartley, E. Q. J., 15, 16.Hartley, H., 26.Hartmann, M., 142.Hassler, F., 200Hauser, O., 192.Haworth, W. I?., 98.Hay, J. G., 118.184.Hedley, E. P., 133.Hehner, O., 189.Heikel, G., 201.Heilborn, W., 182.Heller, G., 80, 112.Henderson, G. G., 65.Hendrick, J., 254.Henle, F., 107.Herr, V. F., 201.Herrmann, W., 109.Herschmann, F., 118Herty, C. H., 204.Herz, W., 45.Herzig, J., 200.Herzog, J., 200, 201.Hesse, A., 79.Heubner, W., 236.Hewitt, J.T., 146, 147, 184, 186.Heyn, E., 71.Hiesstand, O., 253.Hildebrand, J. H., 69, 185.Hilditch, T. P., 105, 166, 178, 179.Hill, A. E., 196, 199.Hill, J. R., 105.Hilscher, F., 134, 184.Hinkel, F. C., 202.Hinkel, L. E., 198.Hinrichsen, F. W., 187, 193.Hinsberg, O., 177.Hirszowski, A., 170.Hiihn, F., 53.Holland, W. W., 14.Holmberg, B., 177.Holmes, H., 101.Holmes, Miss, M. E., 194.Hoogenhuyze, C. J. C., van, 227.Hopkins, F. G., 256.Houben, J. , 79.Howell, W. H., 225.Hubbard, I'., 62.Huber, L., 116.Hubert, A., 207.IIudson, C. S., 87.Hugonnenq, L., 171.Hulton, H. F. JL, 208.Huntington, A. K., 189.Hutchinson, G. A., 26.Iliovici, G., 61.Ingle, H., 203.Ipatieff, W. N., 76.Irvine, J.C., 87.Isaac, Miss F., 26.Isham, H., 188.Jaboulay, E., 187.Jackson, C. L., 124, 185.Jacobson, P., 116.Jacoby, J., 197.Jacoby, M. , 216INDEX OF AUTHORS' NAMES. 285Jaeger, F. M., 272, 277, 278.Jakowleff, W., 76.James, C., 60.Jamieson, G. S., 189.Jamieson, J. S., 184.Jannasch, P., 185.Jatar, S. B., 190.Jeancard, P., 204.Jerusalem, E., 219.Jerusalem, G. , 278.Jessen-Hansen, H., 205.Jessup, A. C., 1.Jessup, A. E., 1.Jochheim, H., 157.Johnson, C. M., 188.Johnson, F. X. G., 24, 26.Johnson, W. A., 208.Johnston, S. M., 20.Jones, €3. M., 26.Jones, G. C., 203.Jones, H. C., 24.Jones, H. O., 105.Jones, W., 219.Just, J., 254.Kahm, Miss Z., 192.Kahlenberg, L., 1 92.Kahn, It., 174Kajiura, S., 238.Kantorowicz, H., 175.Karpiijski, A., 245.Karslake, W.J., 183.Kauffmann, H., 7, 9, 130, 135.Kay, F. W., 171.Keane, C. A., 196.Kehrmann, F., 125, 126, 162, 163, 164.Keiser, E. I-I., 64, 67, 196.Keller, O., 167.Kellner, O., 256.Kemnierer, G. I., 38.Kempf, R., 52.Kendall, E. C., 199.Kenner, J., 177.Keppeler, G., 63.Khotinsky, E., 176.Kiliani, H., 88, 187.IZiiiiball, A. W., 197.Kipping, F. S., 175.Kirpal, A., 200.Klaber, W., 118.Kleinschmitt, A , , 256.Klever, H. W., 84.Klostermann, W., 147.Knecht, E., 183.Knoevenngel, E., 177.Knorr, L., 168.Knorre, G. von, 187, 193.Kober, P. A., 196.Koch, H., 188.Koch, M., 67.Koenig, A , 67.Koeniger, P., 158.Kotz, A., 111.Kof, I<., 183.Kohn-Abrest, E., 196.Komppa, G., 102.Koniuck, L.L. de, 188.Kolb, A., 191.Koppel, J., 33.Kostanecki, S. VOD, 149, 154.Kramer, A., 171.Krafft, F., 44.Iiraus, C. A., 66.Krauskopf, F. C., 192.Krauss, L., 199.Kreutz, A., 208.Kron, A., 82.Kropp, W., 171.Kruyt, H. R., 39.Krzemieniewski, S., 243.Iiubli, H., 113.Kiihn, G., 59.Jiuhn, O., 189.Iiuzma, R., 48.Laar, C., 89.Laar, J. J. van, 24.Ladenburg, A., 109.Lalin, L., 85.Lampe, V., 154.Lander, G. D., 182.Landolt, H., 3.Lang, W. R., 175, 189.Lapworth, A , , 81, 82.Law, D. J., 89.Law, H. D., 111.LawroF, D., 218.Leather, J. P., 197.Leather, J. W., 251.Le Bas, G . , 273.Lebeau, P., 42, 44.Le Chatelier, H . , 65.Lederer, R., 238.Leefhelm, L., 80.l.efebvre, C., 198.Lefinann, G ., 228.Lehmann, O., 274.Leithauser, G., 67.Lenher, V., 37, 187.Lenz, W., 199.Le Pla, Miss M., 188.Le Rossignol, R., 177, 178.Leroux, A., 42.Leuclis, H., 168.Levallois, 102.Levene, P. A., 217, 218, 219.Levi, ill. G., 52.Levy, H. L., 189.Lewis, G. N., 20.Lewis, W. C. Bl., 30.Lewkowitsch, J., 203.Ley, H., 138286 INDEX OF AUTHORS’ NAMES.Lidoff, A. P., 184.Liebermann, C., 121, 122.Liebig, H. von, 131.Lifschiitz, I., 198, 199.Lilienfeld, L., 157.Linck, G. E., 40.Liiider, E., 185.Ling, A. R., 202, 203.Lintner, C. J., 202, 208.Lipniari, J. G., 244, 246.Liversedge, S. G., 188.Lochhead, J., 244.Locke, F. S., 225.Lockemann, G., 191.Lob, W., 88.Liihnis, F., 243.Lohmann. A., 238.Lohr, F., 87.Loose, R., 185.Lowry, T.M,, 89.Liippo - Cramer, 5 8.Luff, B. D. W., 175.Luther, R., 47.Lutz, O., 184.Lyons, A. B., 185.Lyons, R. E., 179.McCarthy, E. S., 197.McDonald, D. P., 108.McKay, L. W., 182.McKenzie, A., 109, 110.Mackenzie, J. E., 53.Mackey, J. F., 175.MacLean, H., 238, 241.McMaster, L., 67, 196.McMillan, A., 93.Magson, E. H., 89.Mai, C., 206.Mailhe, A., 75.Main, H., 206.Mnire, hl., 116.Majinia, R., 99.Maineli, E., 252.Manilock, L., 167.Manchot, W., 64, 65.Mandel, J. A., 199, 218, 219.Manea, A., 199.Manniclr, C., 91.Manuelli, C., 62.Marckwald, W., 37.Marie, C., 71.Marino, L., 47.Marsden, Miss E. G., 83.Marshall, H., 53.Martin, F., 46.Mathers, F. C., 64, 190.Matthaiopoulos, G. T., 205.Mattheu, H., 203, 204.Maurichean-Beauprd, 62.Mayer, E.W., 76.Maxwell, S. S., 223.Mdivani, B., 193.Mears, B., 14.Meisenheimer, J., 88, 109.Meldola, R., 84, 118.Meldrum, A. N., 86.Mellanby, E., 226.Mellet, tl., 186.Melzer, W., 176.MQniBre, P., 196.Metzger, F. J., 195.Meyer, F., 63.Meyer, K., 208.Meyer, K. H., 126.Meyer, Ib., 124.Meyer, R. J., 44.Michael, A., 90.Michaelis, A., 167, 174.Micklethwait, Miss F. M. G., 136, 174.Migliorini, E., 52.Miers, H. A., 278.Milbauer, J., 184.Miller, I., 190.Miller, N. H. J., 245.Rliller, O., 89.Mills, W. H , 146.Miiiz, A., 234.Miolati, A., 54, 56.Mitchell, A. D., 145,Modrakowski, G., 239.Moller, P., 40.Mohr, O., 206.Moir, J., 183.Molinari, E., 93, 94.Molz, E., 254.Moodie, bliss A.&I., 87.Moore, C. W., 117.Moore, E. P., lS8.Moore, R. n., 38, 61, 190.Morel, A., 171.Morgan, G. T., 136, 174, 200.Jlorse, H. N., 14, 15.Morse, H. V., 14.Moureu, C., 62, 169.Miiggr, O., 65.Muller, Ernst, 96.hliiller, F., 123.Miiller, G., 196.Muir, M. M. P., 189.Murphy, A., jun., 90.Rlurschlianser, H., 46.Nelken, F., 80.Nerltin, J., 237.Neuberg, C., 59, 88, 199.Neumann, W., 182.Newton, H. D., 189.Nicolardot, P., 190, 193.Nieuwland, C. H., 191.Niklewski, B., 245.Noelting, E.. 165.Noll, H., 197INDEX OF AUTHORS, NAMES. 287Noyes, A. A., 181.Noyes, IV. A., 36, 37.Oddo, B., i 9 .Oehler, E , 52.Ogawa, Al., 35.Ogier, J., 196.Olie, J.. 40.Onnes, H. I<., 60.Opoloslii, S., 133.Orloff, N .A., 183.Orthey, M., 187, 188, 192.Orton, I<. J. P., 83, 92, 127.Osborne, R. W., 82.Osborne, T. B., 256.Ostromisslensky, I. von, 91, 107.Ozorovitz, N., 198.ott, E., 85.Paal, C., 58, 59, 76.Padoa, AT., 75.Palmer, H. E., 82.Panzer, T., 232.Parnas, J., 123.Paw, S. W., 186, 200.Parravano, N., 68.Parrozzani, A., 253.Pascal, P., 56, 58.Paschlce, F., 109.Patten, A. J., 246.Patterson, T. S., 93, 108.Pavy, F. W., 222.Paw’le-ski, B. von, 198.Pearson, Miss C., 92.Pedrina, S., 43.Pallini, G., 43.Peltner, E., 50.Perkin, F. M., 63, 111, 189, 193, 203.l’erkin, W. H., jun., 97, 98, 106, 152,Yerotti, R., 246.Perrot, F. L., 38.Peset, z., 195.Peters, F., 147.Pfeiffer, P., 54.Pfliiger, E., 224.Phelps, I.K., 82.Phelps, M. A., 82.Philip, J. C., 95.Philipoff, O., 76.I’hilipp, K., 165.Piccard, J., 125.Pickering, S. U., 250.Pickles, S. S., 100, 205.Pieszczek, E., 188.Pillai, N. li., 243.Pizzighelli, R., 54, 56.Plimmer, R. H. A., 205, 213.Pokornf, F., 47.Pollacci, G., 252.Pollard, W. B., 181.153, 156.Ponzio, G., 143.Pope, F. G., 135.Pope, W. J., 106, 268 et seq., 278.Popielski, L., 238.Popp, BI., 255.Porcher, C . , 209.Porter, A. W., 18.Potdar, G. N., 62.Potter, hI. C., 246.Pouget, I., 257.Pozzi-Escot, M. E., 182, 190, 207.Prantltl, W., 46.Pratt, L., 63.Price, T. S., 53, 176, 177.Yriestley, J. H., 252.Pringle, H., 222.Pritze, M., 68.Purvis, J. E., 197.Yyman, F. L., 178, 174.Raabe, F., 168.R n h , O., 48.Ttahe, Y., 90, 168.Raben, E., 187.Race, J., 206.Ratfo, RI., 57.Ralcitin, L., 76.Hamssy, Sir W., 4, 32, 61.Baquet, D., 181, 183.Raschig, F., 66, 201, 205.Rassow, B., 89.Ttead, J., 106.Reckleben, H., 68, 191.Recvura, A., 59.Reed, H.S., 248.Keichard, C., 199.Reif, G., 171.Rendle, T., 202.Repiton, F., 187.Rewald, B., 59.Reychler, A., 7:.Reynoltls, H., in, 191.Reynolds, W. C . , 174.Richanlson, F. W., 204.Richmond, H. D., 200, 208.Rimele, E., 96.Ringe, 0.. 49.Roaf, H. E., 205.Kobertsoii, T. H., 29.R,obinson, R., 152, 153, 156.Mobison, R., 175.Rotgers, K., 44.Rohdich, O . , 203.Rohland, P., 251.Xolle, J., 167.Romyn, G., 197.Rorive, F., 199.Rosenheim, A., 33, 68.Rossnheim, O., 225, 233, 235.Rosenstein, M., 190.Rosenthaler, L., 191288 INDEX OF AUTHORS’ NAMES.ROSS, R., 197.Rotarski, T., 104.Roth, K., 76.Rothenfusser, S., 206.Kothmann, A., 227.Rowell, H.W., 192.Ruer, R., 71.Ruff, O., 176.Rupe, H., 100.Rupp, E., 185, 188.Russell, E. J., 250.Ryn, W. van, 192.Sabatier, P., 75.Sacher, J . F., 188.Sachs, F., 175.Sackett, W. G., 246.Saito, K., 197.Salkowski, E., 192, 233.Sand, H. J. S., 194.Sand, J., 55, 56.Satie, C . , 204.Sawjaloff, W. W., 217.Scala, A., 217.Schaefer, K., 83.Scharfenberg, W., 191.Scharf, E., 67.Scheen, O., 194.Scheffer, P. E. C., 26.Scheibler, H., 110, 171.Schenck, It., 53.Schindler, E., 162.Schirmer, W. F., 188.Schlenk, W., 126.Schluederberg, C. G., 64.Schmidlin, J., 135.Schmidt, J., 168.Schmiedeberg, O., 218.Scholl, It.. 160.Scholtz, M., 109.Scholz, H.A., 181.Schoorl, N., 183.Schorigin, P., 79.Schott, E., 66.Schrefeld, O., 202.Srhreiner, O., 247, 248.Schuck, B., 182, 190.Schiilke, K., 80.Schiirmann, E., 191.Schugowitsch, A , 185.Schulz, F., 199.Schulze, K., 253.Schumnnn, A., 195.Schumsnn, T., 56.Schwalbe, C. G., 157.Schwarz, C., 238.Schwarzenbach, R., 162.Scott, F. H., 205, 213, 221.Scott, S. F., 198.Scurti, F. 253.Rudolf, L., 112.Selvatici, E., 182.Senimlor, F. W., 100, 101, 103.Senderens, J. B., 77.Seregenkoff, B., 176.Shaffer, P. A., 228.Sherman, H. C., 199, 202.Shetterly, F. F., 66.Shinn, 0. L., 193.Shorey, E. C., 247.Shukoff, I. I., 65.Sidgwick, N.V., 9.Silber, P., 92.Silbermann, T., 198.Simon, T., 113.Sirnonis, H., 80, 147.Sjollema, R., 191.Slade, R. E., 45.Slyke, D. D. van, 217.Smiles, S., 166, 177, 178, 179.Smillie, R., 82.Smisseii, H. van der, 63.Smith, Miss A. E., 83, 127.Smith, C., 145.Smith, E. F., 51, 69, 195.Smith, E. K., 44.Smith, H. D., 90.Smith, J. L., 232.Smith, W., jun., 89.Sniits, A., 26.Snyder, C. D., 223.Soderbaum, H. G., 246.8011, J., 168.Siirensen, S. P. L., 185, 205Sourlis, A,, 112.Spear, E. B., 49, 181.Spencer, J. F., 78, 188.Spindler, 0. von, 196.Stangassinger, R., 226.Stark, J., 6 .Staudinger, H., 84, 85, 86.Steensma, F. A., 198.Sollas, W. J., 270, 274.Steiger, G., 186.htekl, L., 204.Stern, K. L., 163.Stendel, H., 219.Stewart, A.W., 110, 132.Stieglitz, J., 83, 184.Stine, C . M., 24.Stobbe, H., 92. .Stock, A., 68, 196.Stokes, Miss E. M., 78.Stoklasa, J., 243, 254.Stoward, P., 268.Strdwsch, S., 252.Stremnie, H., 59.Strengers, T., 40.Strohmer, F., 252.Stubbs, J. A., 91.Stutzer, A.. 253.Siichting, H., 196INDEX OF AUTHORS’ NAMES. 289Sullivan, M. X., 248.Sutherst, W. F., 254.Suzuki, U., 253.Sy, A. P., 203.Takaki, H., 235.Tsmbor, J., 150.Tammann, G., 42.Tebb, Miss M. C., 233, 235.Telle, F., 197.Tempany, H. A., 202, 203.Theodor, H., 189.Thiel, A., 194.Thiele, J., 66.Thbrner, W., 208.Thole, F. B., 111.Thomas, V., 79.Thompson, I(. J., 138.Thomson, D., 108.Thorpe, J. P., 11’7.Threlfall, R., 40.Tiffeneau, M., 92.Tilden, W.A., 71.Tingle, J. B., 81, 274, 275.Tizard, H. T., 9.Tollens, B., 199.Tollens, I<., 199.Traube, I., 273.Treadwell, W., 194.Trebing, J., 208.Trevor, J. E., 18.Trivelli, A. P. H., 59.‘l’achelinzeff, W., 78.Tschitschibabin, A. E., 129, 135.Tschugaeff, L., 110, 182.Tsujinioto, RI., 203.Tuck, W. B., 133, 145.Turner, A. K., 204.Turner, M. R., 156.Turrentine, J. W., 52.Tiitin, F., 100.Tutton, A. E. H., 264, 265, 266.Twiss, D. F., 53, 176, 177.Uchiyania, S., 254.Ulrich, K., 64.Urbain, G., 34.Usher, F. L., 252.Utz, F., 201.Valenr, A., 169.Vanino, L., 179.Vegard, L., 15.Veit, T., 66.Veley, JT. H., 185.Venditori, D. , 186.Verploegh, H., 227.Vieweg, W., 89.Vogel, R., 42.Volcy-Bouclier, 198.Voorhees, E. B., 246.Vorliinder, D., 104, 274.Wagner, M., 254.Walden, P., 26.Walden, P. T., 44.Waldmuller, bl., 91.Wallace, Miss bl. L., 78.Wallach, O., 100, 101, 102.Tl-alton, J. H., jiiu., 181.Warburg, E., 67.Warynski, T., 193.W~ashhurn, E. W., 20.Wassilieff, N., 253.Watts, F., 202, 203.Weber, H. C. P., 37.Wechsler, E., 81.Wedekind, E., 66, 108, 109.717edekind, O., 108, 109.Wegscheider, R., 25, 185.Weichliold, O., 110.Weinland, R. F., 56.Weinmarn, P. P. von, 59.Wells, H. L., 189.Welsbach, C. A. von, 34.Wengleio, O., 202.Werner, A., 55, 121, 122.Wheeler, E., 23.Wheeler, R. T., 196.White, C. l’., 232, 233.Whyniper, It., 24.Widdows, Miss S. T., 146.Widemann, M., 188.Willcock, Miss E. G., 256.Willstatter, R., 76, l i 3 , 123. 124, 125,Wilsmore, N. ‘I?. M., 85.Wilson, J. H., 38.Wilson, R. A., 235.Windisch, W., 253.Winiwarter, E. V O ~ , 188.Winter, H. W., 182.Winterstein, E., 253.Winterstein, W., 223.Wirth, F., 60, 192.Wislicenns, IV., 90, 91.Withrow, J. R., 194.Witziiiann, W , 44, 7.2.Wohler, I,., 44, 46, 69, 70, 72.Wohler, P., 44.Wohl, A., 86.Wohlgemiith, J., 207, 216.Wolffenstein, B., 50, 113, 167.Wolter, L., 65, 193.254.wood, J. ri., 185.REP.-VOL. Y. 290 INDEX OF AUTHORS’ NAMES.Woodhams, E. L., 191.Woodhouse, J. O., 189.Woolley, W. J., 224.Wondstra, H. W., 188.Wren, H., 109.Wyronboff, G. N., 6 LYoshimnra, K., 253.Zaleski, J. , 199.Zehenter, J., 200.Zeltner, J., 78.Zenghelis, C., 4.Zerewitinoff, T., i i .Zincke, T., 1.28.Zwayer, F., 149

ISSN:0365-6217    

DOI:10.1039/AR9080500281

出版商:RSC    

年代:1908

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Absorption spectra, 83.of hydrocarbons, 131.of nitro- and nitroso-compounds,133.Acetylation of amino-groups, 83.Acridines, synthesis of, 119.Activity, optical, 105.Adrenaline, 238.Adsorption, 29.Alcohol, estimation of, in wine, 206.Aldebaranium, 34.Alizarin, prodGction of, 114.Alkali metals, separation of, 195.Alkaloids, 167.Allotropy of elements, 38.Alloys, 41.Alumina as catalyst, 77.Amido-myelin, 240.Aminoazo-compounds, salts of, 134.Ammonium chloride, dissociation of, 24.halides, crystalline structure of, 265.iodide, equilibrium pressure of, 25.persulphate, use of, in analysis, 182.reactions of, 199.Anwthetics, 171.Analysis, elementary organic, 199.Antimony, estimation of, 191, 194.Apocyniu, synthesis of, 173.Aqueous solutions, 20.Aragonite, crystalline form of, 277.Argon grocp, 60.Aromatic compounds, production of.from hydroaromatie compounds, 111.substances, oxidation of, 111.Arsenic, estimation of, 191.modifications of, 39.organic derivatives of, 173.Arsine, reactions of, 68.Asymmetric synthesis, 106.Atmosphere, gases of the, 61.Atomic weights, 36.Atropine, synthesis of, 167.apoiltropine, synthesis of, 167.Anrates, preparation of, 63.Axial ratios, 259.Azines, 161.Azoimide, preparation of, 66.Azomethines, 134.Axotobacte.r', nutrition of, 243.Bacteriology of soil, 242.Barium, detection and separation of,separation of, from strontium, 192.percarbonate, 50.sulphate, colloidal, 59.183.Barley, biochemistry of, 207.Benzene, crystalline structure of, 275.Benzeneazo-a-naphthol, p-nitro-, use of,Benzoin, preparation of two opticallyBismuth, atomic weight of, 38.Bistriazoacatic acid, ethyl ester of, 95.Bistriazo-compounds, 95.Bistriazoethane, 95.Boiling point, 25.elevation of, 19.Brazan, synthesis of, 153.Brazilein, constitution of, 152.Brazilin, 150.Brazilinic acid, synthesis of, 152.Bromides, test for, 184.Cadmium, electrolytic separation of,Calcite, crystalline form of, 276.Calcium, properties of metallic, 63.as indicator, 184.active forms of, 109.estimation of, 192, 195.194.bicarbonate, 64.ferrocyanide, vapour pressure andosmotic pressure of solutions of,16.hypochlorite, preparation of dry, 70.sulphate, double salt3 from, 63.Camphor, synthesis of, 102.isonitroso-, 101.Carbohydrates, 87292 INDEX OF SUBJECTS.Carbon, determination of, in soils, 257.estiniation of, 187.monoxide, absorption of, by culwoussnboxide, 85.in iron and steel, 188.chloride solution, 64.estimation of, in air, 196.Carboxonium dyes, 163.Carvenene, 99.isocarvestrene, synthesis of, 97.Caseinogen, 215.Cassiopeium, 34.Catalysis, 74, 82.Cellulose, 88.Cerebrosides, 234.Cerium, estimation of, 192.Chlorates, estimation of, 186.Chlorine, action of silent electric dis-charge on, 41.atomic weight of, 37.Chlorites, detection of, 186.Chlorophyll, 254.Chlorosis, 254.Cholesterol, 231.Choline, 237.Chortosterol, 234.Chromium, complex salts of, 56.Cinchonine, constitution of, 168.Cinchoninone, constitution of, 168.Citric acid, detection of, 207.Claiseu condensation, the, 81.Cobalt, complex salts of, 55.detection of, 182.estimation of, 190.Cobra venom, 234.Cohesion, specific, 27.Colloids, 57.Colour reactions, 198.and constitution, 130.lakes, 121.of salts in solution, 9.Colours, mordant, 121.Columba root, alkaloids of, 169.Colunibamine, 169.Columbium and its compounds, 51.Complex salts, 54.Conduction, rate of, in nerve, 223.Constitution, 31, 32.and colour, 130.Copper, detection of, 183.estjniation of, 189, 194.Couniarin, constitiition of, 149.group, the, 147.Coupling, mechanism of, 141, 142.Creatine, 226.Creatinine, 226.Cryst allin e structure, 25 8.Crystals, liqiiid, 274.structure of, 258.detection of, 183estimation of, 190.Cuoiin, 241.Damascenine, constitution of, 167.Desmotropy, 90.Dextrose solutions, osmotic pressure of,Diamond, crystalline structure of, 270.Diazo-compounds, aliphatic, 94.aromatic, 136.Diazo-salts, constitution of, 136.decomposition of, 137.preparation of, 139.Dielectric constants, 110.p - Diinethylaniinoazobenzei~e - o - car!,-oxylic acid, use of, as indicator,185.a-Dioximes, determination of coniignra -tion of, 110.Diphenanthracridine, synthesis of, 120.Dissociation pressures, abnormal, 24.Electrochemical analysis, 193.Electrochemistry, 11.Electronic theory, 4.Electrons, 2.Elements, allotropy of, 38.Eleniicin, 103.Ethyl tartrate, iuflueuce of solvents cjnEsterification, 82.Eutropic series, 267.Expansion, coefficient of, 2 i .Fats, analysis of, 203.Fenchone, constitution of, 101.Fermentation, alcoholic, 88.Ferrocyanides, analysis of, 201.Ferrous salts, estimation of, 189.Fertilisers, action of, 255.Flavanthren, 158.Flavone group, the, 149.Fluorescence, relation of, and colonr,Fluorine, determination of, 186.Freezing point, depression of, 19.Friedel and Crafts' reaction, 80.15.evolution of the, 1.new, 34.optical activity of, 108.rate of, of acids, 83.130.(:as analysis, 196.apparatus for, 196.Glncose, constitution of, 87.Glycogen, 224.Gold, colloidal, 58.detection of, 184.Graphite, colloidal, 57.Grigiiard reaction, 77.Growth of plants, cheniical changesduring, 252.Clnanylic acid, 219INDEX OFHEmatein, constitutioii of, 153.Hsmatoxylin, constitution of, 150.use of, as indicator, 185.Hsmatoxylinio acid, constitution of,Halogens, separation of, 185.Helium, detection of, 182.Heterocatenic systems, 84.Holoqiiinoids, 124.Homocatenic systems.84.Hydrazine, formation and oxidation of,Hydrazones, 140.Hydrindones, synthesis of, 117.Hydrocarbons, absorption spectra of,behaviour of, a t high temperatures,coloured, preparation of, 129.cyclic, reactions of, 111.Hydrogen, atomic weight of, 36.preparation of, 62.peroxide, detection of, in air, 196.persulphides, 53.Hydrogenation, 75.Hydrolysis, measurement of, 23.Hydroxyazo-compounds, 140.constitution of salts of, 146.Hydroxylan,ates, 67.Hydroxylamine, 66.Hydroxylic compounds, formation ofHypochlorites, detection of, 186.Iminazoles, sguthesis of, 117.lmino-esters, hydrolysis of, 83.Indazoles, synthesis of, 116.Indicators, theory of, 184.Indigoid dyes, 156.Indigotin, 156.separation of iron from, 190.Indium selenate, 64.Indole, detection of, in pus, 209.Inorganic substances, indexing of, 33.Iodates, estimation of, 186.Iridium, complex salts of, 54.oxides of, 72.use of, for crncibles, 195.Iron, coniplex salts of, 56.detection of, in presence of copper,estimation of, 190.rusting of, tl.Isomeric change, 89.Isomorphism, 268.Jateorrhizine, 169.Jecorin, 241.Kephalin, 239.152.liquefaction of, 60.66.131.84.formation and decomposition of, 48.aromatic, 113.190.S UI3 J ECTS.293Kerasin, 235.lietens, 84.Ketones. amino-, preparation of, 114.&Ketonic esters, synthesis of, 79.classification of, 85.Lead, atomic weight of, 38.Lecithin, 236.Lipoids, 229..Liquids, crystalline, 103.Lithium, separation of, from othw alkaliLymphocytes, 222.estimation of, 188.metals, 192.Magnesium, colloidaj salts of, 59.Malt analysis, 207.soluble nitrogen compounds in, 253.Manganese, detection of, 183.estimation of, 192.Manures, 255.Mass, conservation of, 3.Mercui ic chloride, detection of, in nitro-cellulose, 183.Mercury, coniplex salts of, 57.estimation of, 188.vapour, detection of, in air, 196.Meriquinoids, 124.Mesotropy, 90.Metabolism, 220.Metals, catalytic action of, 74.preparation of colloidal, 58.rapid electrolytic separation of, 194.Metanil-yellow, use of, as indicator, 185.Metastable state, 26.Methane, synthesis of, 84.Methyl alcohol, detection of, in ethylalcohol, 198.a-Methylcamphor, 102.%Methylcarvenene, 100.Methylethylaniline oxide, resolution of,108.Methylsparteine, 169.Migration, 92.Milk, analysis of, 208.Molecular constitution, 38.volume, 28.weight, 28.Molybdenite, new element from, 35.Molybdenum, complex salts of, 56.Morpholquinone, synthesis of, 16s.Naphtho-blue, 164.Neodymium, detection of, 184.Nickel, detection of, 182.estimation of, 190, 194.Nipponinm, 35.Nitric acid from the atmosphere, 67.Nitrides, 65.Nitrification, 244294 INDEX OFNitrites, production of, from atmos-Nitro-compounds, aromatic, reductionNitrogen, determination of, in scils,pheric nitrogen, 67.of, 112.257.fixation of, 242,peroxide, detection of, in air, 196.Nucleic acid, 218.Nutrition, chemistry of animal, 255.Oils, analysis of, 203.Optical activity, 106,Origanene, 100.Osmotic pressure, 13.Oxazines, 160.Oxidation of aromatic substances,Oxides, reduction of, 43.Oximes, formation of, 83.Oxonium salts, 154,156.Ozone, detection of, in air, 196.Ozonides, 93.formation of, 49.111.Palladium, atomic weight of, 38.colloidal, 58.hydrated sesquioxide of, 46.Palmatine, l i 0 .Paraffins, niolecular volumes of nor-Perchlorates, crystalline structure of,Periodates, estimation of, 186.Permanganates, crystalline structure of,264.Peroxides, 47.Per-salts, 47.Perstannatcs, 51.Persulphates, formation and reactionsof, 51.a-Phellandrene, synthesis of, 100.Phenolphthalein, 184.Phenols, chlorination aud broiniiiationPhenophen an t hracridine, syn tliesi s of,Phosphates, detection of, i n minerals,Phosphatideq, 880, 235.Phosphoric acid, estimation of, 187.Phosphorus, estimation of9 187, 196,mal, 2i3.264.of, 128.120.184.forms of, 40.and its compounds, glowing of, 67.sulphides, 68.Photochemical reactions, 12.Photochemistry, 11.Phrenosin, 235.Physical properties, relations between,Picric acid, estimation of, 201.Plasteina, 217.26.IUBJECTI'S.Piatinuxn, detection of, 184.Polyhalides, 54.Polypeptides, 170.Potassium, precipitation of, as cobal ti-nitrite, 192.nitrate, crystalline form of, 277.Praseodymium, detection of, 184.I'ropiolic acid, synthesis of, 79.Protagon, 234.Protein nomenclature, 212.Proteins, reactions of, 205.Protons, 1.Pruneaiiilide, constitation of, 160.Pyranol salts, 154.Quinones, 122.synthesis of, 123.Racemates, triboluminescence of, 13.Radium, atomic weight of, 64.Rare earths, 60.Reactions, mechanisni of, 74.Red lead, assay of, 188.Reduction of aromatic nitro-compounb,preparation of, from pitchblende, 64.112.of osides, 43Rcfractorneter, use of, 206.Reinite, new element froin, 35.Rennin, 215.Resorubin, 185.Respiration, 221.Rhodium, complex salts of, 55.use of, for crucibles, 195.Ring formation, 114.synthesis of a seven-membered, 120.Rings, formation of five-membered, 117.heterocyclic, coiitaining oxygen, 147.Rongalite, constitiition of, 178.Rosamine, 164.Rosaniline group, the, 164.isoRosindone, constitution of, 162.Rosocyanin, 185.Rotatory power, effect of electrolytes andRuthenium, detection of, 1%.non-electrolytes on, 24.Salts, colour of, in solution, 9.Santene, constitution of, 101.Secretin, 238.Selenates, crystalline form of alkali,265.Selenium ~onipounds, organic, 179.Selenoniuni derivatives, 179.Sensitisers, theory of, 12.Sewage, analysis of, 197.Silica as catalyst, 77.Silicon componnds, organic, 175.complex, 54.estimation of, i n acetylene, 196INDEX OF SUBJECTS.295Silver, colloidal, 58.detection of, 183, 184.estimation of, 188.photochemistry of, 56.halides, separation of, 186.chloride, solubility of, in mercuricnitrate solution, 186.iodide, crystalline structure of, 277.Skraup’s reaction, use of, 118.Soda-cellulose, 89.Sodium nitrate, Crystalline forin of, 276.perborate, 51.percarbonates, 50.peroxide in qualitative analysis, usechemistry of, 246.physics of, 250.Solutions, aqueous, 20.freezing-point depression and con-of, 181.Soil, bacteriology of, 243.ductivity of mixed, 24.Sparteine, constitution of, 169.Spectra, band, 8.Spectroscopy, 8.Sphingo-myelin, 240.Starch, estimation of, 201Steel, analysis of, 191.Steric hindrance, 83.Stilbene compounds, synthesis of, 112.Strontium, separation of, from barium,Sucrose solutioiis, osmotic pressure of,Sugar, r81e of, in muscular activity, 225.Sugars, analysis of, 202.Sulphates, crystalline form of alkali,Sulphination, 177.Sulphinic acids, aromatic, constitutionSulphur, atomic weight of, 38.192.14.reactions of, 199.265.of, 178.colloidal, 57.estimation of, 186, 196.nature of molten, 39.compounds, cyclic, 165.organic, 176.purification of, 68.Sulphuric acid, manufacture of, 69.Surface tension, 27.Synthesis, asymmetric, 106.Tannin, estimation of, 207.Tartaric acid, estimation of, 207.Tautomerisni, 89.Telliirium, atomic weight of, 37.estimation of, 187.compounds, organic, 179.Terpene group, the, 97.synthesis of, of the five-carbon series,98.Terpenes, bicyclic, 100.Terpin, synthesis of, of the five-carbonseries, 98,Terpinene, 99.Terpineol, synthesis of, of the five-Terpineols, synthesis of two opticallyTetrahydrocarbazole, synthesis of, 119.Tetrathionic acid, constitution of, 53.Tetrazines, synthesis of, 96.Thallium, estimation of, 183.Therapeutic agents, synthetical, 171.Thianthren, constitution of, 177.Thienyl derivatives, synthesis of, 79.Thioacetic acid, use of, i n analysis, 182.Thiocoumarin, constitution of, 149.Thioindigo dyes, 157.Thionaphthen compounds, 157.Thiopyrine, constitution of, 166,Thiosulphates, preparation of dry, 69.Thorianite, new element in, 35.Tin, estimation of, 191.Titanium di-iodide, 46.Toxins in plants, 246.Transport numbers, 20.Triazoacetaldehyde, 94.Triazoacetone, 94.Triazoacetylhydrazide, 95.Triazo-compounds, aliphatic, 94.Triazoethyl alcohol, 94.‘Criboluminescence, 1 3.Trimethylbrazilin, 150.Triphenylmethyl, constitution of, 135.Tungsten, estimation of, 193.coniplex salts of, 56.Umbellulone, constitution of, 100.Valency, 32.relation between, and volume, 271.volumes, law of, 271.Vanadium, estimation of, 190.compounds, 46.Victoria-blue R., 165.Viper venom, 234.Viscosity of solutions of rscemic salts,carbon series, 98.active, 98.new oxide of, 48.oxide, T1,0,, 195.scarlet, 158.refraction and dispersion of, 95-110.of tautonieric substances, 91.Ulalden inversion, 109.Water analysis, 197.Waters, radioactivity of thermal, 62.Zinc, detection of, 182.estimation of, in f’ocds, 208.electrolytic estiniatioii of, 195RICHARD CLAY AND SONS, LIMITEDBREAD ST.HILL, E.C., ANDBUNCAY, SUFFOLK

ISSN:0365-6217    

DOI:10.1039/AR9080500291

出版商:RSC    

年代:1908

数据来源: RSC