摘要:

ANNUAL REPORTSOh’ THEPR;OGRESS OF CHEMISTRYF O R l 1 9 1 7 .LSSUED BY THE CHERIIC‘AL SOCIEFY.&ommittat o f @itblicatioii :A. CHAbTOX C H A I ’ M A S .M. 0. ~ O l W l E l : , I>.Sc., Ph.D., F.R.S.A . W. C~:OSSLEY, C.N.G., D.Sc., F.R.S.A. HAHI)ISK, D.Sic.., PII.D., F.1i.ST. A. I ~ E Y R Y , D Sc.T. R1. L o ~ v i t ~ , 0. B. E., D. Sc.. F.R.S.J. C‘. I ’ I I I I . I P , D.Sc., 1 ’ 1 1 . 1 ~ .J. F. ‘I’IIOI<PE, C.13.E., I).Sc.., l)li,I),,F. K. S.&bitor:J. c!. CAIX, D.Sc.Siib-Qbitor :A.TJ. GREENAWAY.Go irt ri b 11 tor E; :B. C. C’. I ~ A L Y , P.R.S.T. T. I ~ A R K E ~ : , M.A., 11. Sc.H. bl. DAWSOR, D.Sc., 1% D.F. GOWLANII HOPKIKH, M A . , M.B.,D. Sc., F. K.S.V O l . XIV.L O N D O N :GURNEY & J A C K S O N , 33, PATERNOSTEl< ROW, E.C.4.1918PRINTED I N OREAT BRITAIN txHICHARD CLAY AND SONS, LIMITED,SUUlrBH i C K STREET, STAMFORD BTHEET, tj.24h’D BUNYOLI. BUTTOLHC 0 N T E N T S .PAGEGENERAL ANI) PHYSICAL CflEMIS'l'RY. By H. ill. I)A\v\os, L).Sc.,1'h.D. . . . . . . . . . . . , 1INORGANIC CHEMISTRY. By E. C. C. HALP, F.R.S. . . . . 27ORGANIC CHEMISTRY :-Pait ~.-ALIPHATIC D r r ~ s r o ~ . I3y J. c'. ~ ~ ~ V I N E , D.S(z., F'h.L). . . 61Part II.-HOMOCYCLIC DIVISIOF. Ry F. L. PYMAN, D.Sc., P11.D. . . 92Part III.-HICI.E:IIOCTCLIC DIVI~ION. By A. W. Q'~P,WART, D.Sc. . . 119ANALYTICAL CHERtISTRE'. By C'. AINSWOI:I'H NITCHELL, F. 1.C'. . . 146PHYSIOI~OCJICAI, CHEMISTRY.D Sc., Y.R S . . . . . , . . . . . . 171By F. GOWLAND HOPKISS, N.A., 11.K.,AGRICULTURAL CHEMISTRIT ANI) VEBJ3'I'AI:LE PHYSIOI>O(=T.By E. ,J. RVSSELL, O.K.E., D.Sc., F.R.S. . . . . . 197H . S c . . . . . . . . . . . 626C'RYSTALL(X8RAPHT AKD ;1IINEItALOGJ'. By T. Tr. I$AI:KEI:, Jl.A.TABLE OF ABBREVIA‘L‘IONS EMPLOYED I N THEREFERENCES.J u u KN A L.Atistiacts in Jouimal of the f lieriiical Po(siet\-. ’Abliaiitilniigen dei. Hohmisclien Ak:uleiiiirs.A cta Societatis Scieiitiarum Fcnnicae.Allgenieine Bran- iind I-Ioptii-Zeit iiiig.Aii~rri air Cliemicnl Jnuriial.Aiiiericnn Jonrrial of Science.Ailales tle In Societlntl KsiiaEola Fisica y Quimicn.Anales de 1:t Socittdati Chimica Armtitiiia. . ‘!’he Aiialyst... Annals of Botany.. Annales de Chiniie... Annali di Chiniica Apihlicata.. . Ariitnlrs tles hliiies. .Aniiales tle 1’Iiistitut Pasteiu. . Aniialen der Pliysil;... Aiiiialcs deh Scit.iict,s Agi.onomiqiies. . Arlwiteii der I)t.ntschc.li I,aii(lsu.ii tschi~ftlicli~ 11. Archivio di Fariiiatwlogia cperimviitale e St:it.nze aiiiij:.. hrcliiv der 1’h:ii.ninzie.. Arlriv liir Iicnii. Jlineialogi och Geologi. . Astiupli) .Licit1 .lg)iiri;al.. Atti cle!la Ke;ilt. Aiwdeniia dei 1,iiict.i. . Bericlite (lei, Dviitschen clieniischen Gesellscliaft . Rerirlit,. cler D e i ~ t s i ~ l i e ~ i hotanisc!ieii Gesellschaft. .. 13eric:lite CItAr Ih~iit?;c*hr~n l’1i:tniiazentisctleli C;esc~ll-Jiistiis Liebig’s Aiiiialen iler Chemie.Annales cle Chiiiiie atial! tiqne :ilq~liquBe al’Intlustrie,h l’Ag,t.icultnrc, B la I’hwrniacie et b la 13iologic.Alinales de (’hiillit; et de l’hysiqiir.Annnnl Re1:orts ot’ tlie Clicniical Socicty.(:esrllsc.lrat’t..sc h n ft,.* The ycnr i s not inserted in references t o 191viii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ABBKEVtATED TITLE.Bull. Amer.Inst. M ~ L Eng.Bull. Assoc. Chiin. Sucr.Dist. . . . .Bull. Sci. PhrwmacoE. .Bull. SOC. chim. . .Bull. ,Yo'oc. franc Miir. .Centr. Rakt. Par. . .Centr. Miqt. . . .Chew IVeekbZnd . .Chm. Zeil. . . .Chem. Zentr. . . .Compt. rend. . . .Deut. Landvi. Presse . .Xng. and Milt. J. . .Fr, Put. . . . .Fuhli.I&gs Landw. Zeit. .Qazzettu . . . .Illustr. Lrc~clw. Zeit. . .lnt. Mi:. Rodenkunde . ,Inter. Zeitsch . Phys. -&em.Rid. . . . .Jahrb. Mix. Beil. Bd. .Jahrb. Radwdtiv.Elek-troaik . . . .J. Agric. Resenrch . ,J. Amer. Chcnz. SOC. . .J. Biol. Chem. . . .J. Bd, d y r i c . . . .J. C7hl:m. Md. a d dlin. SOC.S. Africa . . .J. Ch.im. p h p . . . .J. Gcol. . . . .J. Bygiene . . .J. I d . Eng. C'hem. . .J. Laudw. . . . .J. Path. Bacf. . . .J. Pharm. Chim . .J. Physical Chern. , .J. Yhysiol. . . .J. pr. Chen~. . . .J. R,y. Agric. Xoc. . ,J. RUSR. Phys. Chem Soc. .J, Agric. Sei. . .J. SOC. Chem. Ind. .J . 7Vmhi.ILgton Acad. Sci.Jourti. Chem. Sac. .Koll. Chlj>n. Beilzqfte .Ko Ela id-& Ltsch.Laircct . . .Land w. Vermchs- Stat.Metid. Nobl Inst. .Mew. % I / . Sci. Kyat6JOURNAL.Hulletiii of the Anierican Institute of MillingBnlletiii de 1'Association des Chimistes de SacrerieBulletin (les Sciences Phartnacrllogiqucs.Bulletin de la Societ6 chimique de France.Bulletin tle In.Soci6t6 friinpaise de MinBralogie.Centralblatt fiir Bak teriologie, Parasitenkunde undCetitralblatt fiir llinerdogie, Geologie uiid Palaon-Cheiniscli Weekhlad.Chemiker Zeitung.Uheniisches Zeiitralblatt.Comptes rendus hebdomadaires des SQances de1'AcadQmie des Sciences.Dentsdie Laird wirtschaftliche Presse.Engineeriug ant1 Mining Journal.French Patent.Fiililings L;Liiirwirtschnftliciie Zeituug.Gazzetta chiniica italianaI1 1 nstrirta Lnndwirtscl t aftliche Zeitung.Internationale Mitteilungen fiir Bodeiikunde.Internationale Zei tschrift fiir physikalisch-chernisoheNeues Jahrbuch fiir Minerxlogie, Geologie undJahrbuch der Radioaktivitat und Elektronik.Engineers.et de Distillerie.Infektionskrankheiten.tologie.Biologie.PaI:eontologie, Beilitge-Band,Jouriial of dgricultural Research.Jouriial of Agricultural Science.Journal of the Anierican Chemical Society.Journal of Biological Chemistry, New York.Journal of the Board of AgricultureJoiirtral of the Chemical, Metallurgical and Mineral-ogical Society of South Africa.Journal de Chitnie physique.Jouriial of Geology.Jouriial of Hygieiip..lournd of Itidustrial and E~igirieering Chemistry.Jouriial fiir Landwirtschat't.Journal of Pathology and Bacteriology.Journal de Pharrnacie et de Chimie.Journal of Physical Chemistry.Journal of Physiology.Journal fiir praktische Chmiie.Jonrnal of the Royal Agrivul!ural Society.Journal of the Physical arid Chemical Society ofJouriial of the Society of Chemical Industry.Journa! of the Wasliiiigton Academy of Sciences.Jouriial of the Chrniical Society.Iiolloidcheniische 13e11; et'te.Kolloid-Zei tschrift.The Lancet.Die landwirtschaftlichen Versuchs-Statiunen.Ale(lde1andeii frail Kongl.Vetenska1)sakademiensRleinoirs of the Coll(!ge of Science, Kyat6 ImperialRussia.Nobel-Institut.Uriiversi ty TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCE. isABBREVIATED TITLE.Mem. Xaitchcstcr P h i l . SOC.Xet. Chcm. Eny. . .Alin. Mag. . . .Mitt. deut. Landiu. Ges. .Monutsh. . . . .Munch. Afed. Woch. . .Nachr. Ges. IViss. GotlingcicXatimwiss. Bmdsehau .Oestcrrcich. Zeilsch. Zucker-irrri?.. . . .P . . . . . .Phnrm. Weekblnd . .Philippine J. Sci. . ,Phil. Mag. . . .Phil. l’ranv. . . .Proc. K. Akad. Welemch.Amslcrdmn. . . .Proe. Physiol. Xoc. . .Proc. Roy. Irish Acad. ,Proc. Roy. Soc. . . .Proc. Roy. Soc. Edin. .Proc. Xoc. Exp. Biol. dled. .Quart. J exp. Physio2.Rec. trav. chim. . .Biv. Min. Crist. Ital.Schweiz. Apoth. Zcit.Skand. Arch.iv Physiol.Soil Sci. . . .T . . . . .Trans. Faraday Soc. .U.S. Pat. . . .Wien. klin. Wwh. .Wien. Landw. Zeit. .Zeitsch. anal. Chem. .Zeibch. angew. Chent.Zeitsch. nnorg. Che?)~. .Zeitsch. Elektrochem. .Zeitsch. Hyyiene .Zeitsch. Kryst. Min. .Zeitsch. Nahr.-Genussm.Zeitsch. physiknl. Chem.Zeitsch. physiol. Chem. .JOURNAL.Memoirs and Proceedings of the Manchester LiteraryMetallurgical and Chemical Engineering.Mineralogical Magazine and Journal of the Mineral-Mil theilniigen der deuischen LaadwirtschaftliclienMonatshefte fiir Chemie und verwandte Theile andererRliincheiier Medizinische Wochensclirift.Naciirichten voii der Ko!iigliclien Gesellscliaft tlerNaturwissenschaftlich Runclscliau.Oesterreichische Zritschrift fiir Zuckerirtdustrie.and Philosophical Society.ogical Society.Gesellschaft.Wissenschaften.Wissenschaften zii Gijttingen.Proceedings of the Cheniical Society.Pharmacmtiscli Weekhlad.Philippine Jourtial of‘ Science.Philosophical Magazine (The London, Edinburgh autlPhilosophical Trmsactions of the Royal Society ofKoninklijke Akadeniie van Wetenschappen te Ainster-dam.Proceedings (English version).Proceedings of the i’hj siological Society.Proceedings of the Royal Irish Academy.Proceedings of the Royal Society.Proceedings of the Royal Society of Edinburgh.Proceedings of the Society for Experimental BiologyQuarterly Journal of Expzriinental Pliysiology.Rzcueil des travaux chimiquea des Pays-Has et de laItivistn di Mineralogia e Cristnllografia Italiaiia.Schweizerische Rpotlieker Zeitung.Sksndinavisches Archiv fiir Yhysiologie.Soil Science.Transactions o f the Chemical Society.Transactions of the Faraday Society.United States Patent.Wiener klinische \Vochenschtift.Wiener 1,andwirtschaftliche Zeitung.Zeitschrift fur analytische Chemie.Zeitschrift fur angewandte Chemie.Zeitschrift fiir anorganische und allgemeine Chemie.Zeitschrift fur Elektrochemie.Z ei tschri f t fur H ygieii e und 1 n fek t ionsk rank hei ten.Zeitschrift fiir Krystallographie und Mineralogie.Zeitschrift fiir Untersnchung der Nahrnngs- undZeitschrift fiir physikalische Chemie, StochiometrieHoppe-Seyler’s Zeitschrift fur physiologische Chemie.Dublin).Londot I .and Medicine.Helgique.Genasrrii ttel.und Verwandtschaftslehre

ISSN:0365-6217    

DOI:10.1039/AR91714FP001

出版商:RSC    

年代:1917

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.THE past year has been marked by a very considerable reductionin the number of papers that have come under review. Thisdecrease is more pronounced in those papers which deal with thedetermination of atomic weights and with the more theoreticalside of inorganic chemistry.Among the latter, however, is one which perhaps merits morethan a passing notice, namely, Professor Harkins's paper on thegenetic relationship between the atoms. There is no doubt thatradioactivity, together with the discovery of the existence ofisotopes, has reawakened an interest in the question of the genesisof the elements. The conception of the hydrogen-helium structureof all atoms with an atomic weight greater than 4 was firstenunciated two years ago, and the evidence in its favour is soremarkably convincing that i t surely must receive earnest COP-sideration by all chemists.The papers which deal with the preparative side of inorganicchemistry show but little decrease in number, and, in general, itmay be said that the work carried out during the past twelvemonths exhibits more bhan the usual interest.A tomic Weights.The past year has been remarkable in the fact that much lesswork has been published on the determination of atomic weightsthan during the preceding year.The International Committeedirect particular attention to this, and point out that i t is due in themain to the entry of America into the war, for i t is in this countrythat so many important atomic weight determinations have beencarried out in recent years.No change in the values as adoptedfor 1917 has been rcommended by t'he Committee, and, indeed, theCommittee has decided to intermit its annual reports.Attention may be directed to a suggestive paper dealing withthe genetic relationship between the atoms of the elements.* InW. D. Harkins, J . Amer. Chem. SOC., 1917, 39, 856 ; A., ii, 303.228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.previous papers on this subject’, i t has been suggested that theelements are intra-atomic compounds of hydrogen.213 Thehydrogen first becomes helium, and this becomes a secondary unitof fundamental importance in the formation of all the elementswith atomic weights greater than its own. The ninety-one knownelements, other than hydrogen, fall into two series.At any rate,among the elements of low atomic weight, the atoms having eve’natomic numbers are in general built up of helium atoms, and there-fore may be said to have the general formula nHe’, whilst thosehaving odd atomic numbers seem to have the general formulanHe’ + HIg, these formulze representing intra-atomic, and notchemical compounds. If the elements actually belong in two series,as the hypothesis indicates, then the distinction between the twoshould be apparent in a t least one fact concerning the respectiveelements. It was shown in the previous papers that the atomicweights of the elements, interpreted in the light of the method bywhich radioactive elements disintegrate, give almost conclusiveevidence in favour of the theory.Extremely striking additionalevidence is now adduced in support of this hypothesis. Theordinary periodic system appears to be a relationship which ex-presses graphically the variation in the arrangement and thenumber of external electrons, especially the valency electrons, inthe atom, which finds its expression in the chemical and physicalproperties of the element. The hydrogen-helium system is mostfundamentally related to the structure of the nuclei of the atoms,and this structure should not affect the arrangement of the externalelectrons if the nucleus is extremely minute, since this arrange-ment would depend on the number of electrons, which in turndepend on the nuclear charge, but not on the internal structureof the nucleus except in so far as this structure affects the totalcharge.The structure of the nucleus should, however, affect itsstability, which would have an expression in the abundance of therespective elements. There is another factor, too, which wouldhave an effect on the abundance, and that is the relative abund-ance of the special materials used in the formation of the elementin question. The abundance of the elements in the earth’s crustmight seem to give the best information in this respect if it werenot known that the surface of the earth has been subjected tovery long-continued differentiative processes, and so has a verylocal character. The meteorites, on the other hand, Lome frommuch more varied positions in space, and a t the same time show2 W.D. Harking and E. D. Wilson, J . Amm. Chem. Sac., 1915, 37,3 W. D. Harkins and R. E. Hall, ibid., 1916, 38, 169; A., 1916, ii, 241,1367, 1383, 1396 ; A., 1915, ii, 543, 544INORGANIC CHEMISTRY. 29much less indication of differentiation. In the meteorites, theelements of even atomic numbers on the average are about seventytimes more abundant than the odd-numbered elements, and, more-over, if the elements are plotted in the order of their atomicnumbers, it is found that the even-numbered elements are in everycase very much more abundant than the adjacent odd-numberedelements. Almost more striking than this is the fact tliat thefirst seven elements, in the order of their abundance, are all even-numbered, and, furthermore, make up 98.78 per cent.of thematerial. Both the iron and the stone meteorites separately showthe same relations. Thus the stone meteorites contain 97.6 percent. and the iron meteorites 99.2 per cent. of even-numberedelements. It is remarkable that the highest percentage found forany odd-numbered element in any class of meteorites is 1.53, whilstamong the even-numbered elements larger percentages are commonand range even as high as 90.6 per cent. I n the lithosphere,whilst the relationship is not so striking, the even-numberedelements are still seven to ten times as abundant as those whichare odd, depending on whether the calculations are made by weightor by atomic percentage. Among the rare earths, the even-numbered elements are the more abundant.Among the radio-active elements, the odd-numbered element is in each case eitherof a shorter period than the even-numbered or else as yet undis-covered. All the five unknown elements are of odd numbers.The elements of low atomic numbers are found to be much moreabundant than those of higher atomic number, both in meteoritesand on the earth. Thus the first twenty-nine elements make upabout 99.9 per cent. of the material, while the remaining sixty-three are either extremely rare or comparativeIy rare.The above results seem t o show that the elements fall into twoseries, as predicted from the hydrogen-helium structure hypothesis.The variation in the abundance of elements would seem to be theresult of an atomic evolution, which is entirely independent of theMendeleev periodic system. The formation of the elements seemsto be, however, related to the atomic number.The hydrogen-helium structure of the atoms is seen to be on as firm a basis as alarge number of the ideas of physics or chemistry which areaccepted without question, since the predictions originally madehave been verified in so striking a way. The first prediction wasthat' the elements of low atomic number would be found to showevidences in their atomic weights that their atoms are built upaccording to the general plan, in relation to which the radioactiveelements (of high atomic weight) disintegrate. The second p r ediction was that the elements of even atomic number would sho30 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.a marked difference in abundance from those of odd atomic numberThe agreement with both these predictions is very much morestriking than was a t first expected, and this agreement involvessuch a large number of data that it is 011 this account even themore remarkable.I n general reference to the stability of the elements, it is to beexpected that the composition of the nucleus should affect its ownstability, which from radioactive evidence means the stability ofthe atom.From this point of view, i t is reasonable to supposethat the atoms of one of the series, the even or the odd, should bemore stable than those of the other. There is a t least one otherfactor than stability which must be considered in this connexioa.Since the formula for the odd-numbered elements is nHe'+ HI,, itis evident that, if the supply of H, was relatively small a t the timeof formation, not so much material would go into this system.Thiswould be true whether the H, represents three atoms of hydrogenor one atom of some other element. With regard to the latteralternative, i t is a t least remarkable that' the H, occurs eleventimes in the system for the first twenty-seven elements, whilst H,and H each only occurs once, and it may also be mentioned thatthe atomic weight of nebulium has been determined by interferzacemethods to be 2.7, and this is believed to indicate a real atomicweight of 3.4It has been shown in support' of the above theory that in thecase of the elements with atomic numbers 81 to 92, the numberof known isotopes in a pleiad and the character of the predominantradiation show a periodic variation of the type to be expectedfrom the theory.5 It appears that the isotopes of even-numberedelements are more numerous than those of odd-numbered elements.The former show a well-marked tendency to undergo disintegrationwith the emission of a-rays rather than of 6-rays.These factsaccord with the hydrogen-helium hypothesis,Phosphorescence.An important paper has been published dealing with thephosphorescence of zinc sulphide, which especially treats of theeffect of various impurities on the brilliancy and also on the natureof the illumination.6 One statement in this paper is so categoricallyopposed to the now generally accepted theories of this phenomenonC.Fabry and H. Buisson, Astrophys. J . , 1914, 40, 256.N. F. Hall, J . Amer. Chem. Soc., 1917, 39, 161G; A . , ii, 438.Miss E. MacDougaII, A. W. Stewart, and R. Wright, T . , 1917, 111,663 ; A . , ii, 471I NO RG A N IC CH EM ISTKY. 31that it is worthy of careful consideration. I n general, i t mightbe considered that phosphorescence is a physical phenomenon, andhellce can scarcely find a place in a discussion of recent advancesi a inorganic chemistry, but the principle involved is one of greatimportance to inorganic chemists, and more particularly to thoseengaged in work on the rare earths. The statement in questionis that pure zinc sulphide, when suitably treated, exhibits phos-phorescence.Now it would seem to be established beyond anyquestion of doubt by t h s work of Lenard and Klatt,' and byUrlsain and Bruninghaus,* that it is a cardinal principle of thisphenomenon that no pure substance phosphoresces, and that phos-phorescence is essentially a property of diluted matter. Thephenomenon of phosphorescence is one of the most valuable adjunctsto work on the rare earths, for it is one of the most stringenttests known as to the individuality of a rare earth. The methodof work employed by the French school is the' fractionation of amixture of rare earths by some suitable method. The equivalentsof the successive fractions are determined, and these are plottedon a graph against the numbers of the fractions. As the workproceeds, the curve shows flat portions, due t o the separation ofdefinite individuals or of mixtures which cannot be separated bythe method adopted.I n order to determine whether the frac-tions with constant equivalents contain one individual or a mix-ture, their power of phosphorescing is tested. If any phosphor-escence is exhibited, then it is known that the substance is amixture and not one single individual. It follows, therefore, that,if it be established that a pure substance can phosphoresce, thengrave doubt is a t once thrown on the whole of the work of theGerman and the French schools. Very great care should be takento test in the most rigid way possible the absence of any impuritybefore such a statement is made that pure zinc sulphide phos-phoresces.As an example of the phosphorescence of a smalledpure material may be quoted the case of lime prepared irolncalcite. It certainly might be thought that in this case the phos-phorescence is that of a pure substance. It' was proved, however,that the luminescence is in reality due to the presence of tracesof manganese. A second instance, now almost classic, is eookes'swork on samarium and the citron band of phosphorescence. Bythe adopiion of a suitable method of fractionation, it, was foundpossible to obtain fractions which a t first showed this band withincreased intensity. A continuation of this separation produceda material which suddenly lost its power of phosphorescing, aP. Lenard and V. Klatt, Ann. Physik., 1904, [iv], 15, 285, 485, 633.0.TJrbain, Ann. Chinz. Phys., 1909, [viii], 18, 222, 28932 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.startling enough result until the explanat,ion was forthcoming inthat pure samaria does not phosphoresce.It would seem that in the case of the zinc sulphide the authorsdid not take any absolutely rigid precautions against the presenceof any impurity in the samples examined. Possibly they werenot aware of the fundamental importance of their statement thatthe pure zinc sulphide does show luminescence. It is to be hopedthat this statement will not be accepted as proven until the mostrigid precautions have been taken, and that the authors them-selves will be able further to investigate the phenomenon fromthe particular point of view of the total absence of all impurity.It would indeed seem that the variation observed by them in thephosphorescence caused by added impurity is in itself evidencethat the luminescence is due to the presence of impurities hithertounrecognised.This must not in any way be considered as an adverse criticismof the work under discussion, which in general forms a distinctcontribution to the literature on the phosphorescencg of inorganicsalts.A t the same time, the section of the paper dealing withthe phosphorescence of pure. zinc sulphide is so brief that onecannot believe that the authors were aware that their statement,if true, would controvert the results of very many years’ workcarried out with the most extraordinary care by the Germanphysicists and the French chemists.Exactly the same criticism must be made of a similar statementregarding magnesium sulphide, and in this case the author claimsspecifically to have prepared pure magnesium sulphide and to haveobserved the phosphorescence.9 The compound was made by pass-ing a stream of hydrogen and sulphur vapour over red-hot granularmagnesium.In this way, a crude product was obtained contain-ing 30 to 50 per cent. of sulphur. The free metal in the crudesulphide was removed by distillation a t 600-700° in the vacuumof a mercury pump, or by adding bromobenzene to an etherealsuspension, the sulphide being quite unaffected. Pure magnesiumsulphide is stated to have been prepared in this way, but it is veryquestionable whether any trust can be placed in the statementthat pure magnesium sulphide shows phosphorescence when sucha statement is based on the phenomena exhibited by a compoundprepared in the above way.I n the first place, it is legitimate toask whether the magnesium used was absolutely pure and whetherthe hydrogen and sulphur were free from all suspicion of impurity.What evidence is there that no impurity was derived from thebromobenzene or the ether in the one case or from the mercuryE. Tiede, Ber., 1916, 49, 1745; A., 1916, ii, 619INORGANIC CHEMISTRY. 33vapour in the other? This evidence can carry no convictionthat' such an important discovery has been made as that an abso-lutely pure chemical individual shows phosphorescence.Val en cy .In this section, few papers have been published.Ephraim hasextended his observations on the formation of addition complexesand their dissociation pressures, but consideration of these may bepostponed until the theoretical developments are more complete.Mention may, however, be made of a paper on the structure ofinorganic compounds which presents points of some interest.1°The view had already been put forward that every element possessespositive and negative affinity, and that atoms may be united toeach other by one of these or by both a t the same time. I n theformer case, ioiiisable atoms are formed, due to one affinity beingfree and therefore able t o combine with the solvent. I n the lattercase, non-polar compounds are produced, such as methane andcarbon tetrachloride.Since the elements, for example, copper andcobalt, do not' combine with ammonia, they do not possess negativeaffinity. On the other hand, in their salts, having lost electrons,they develop negative affinity, and hence they can combine withammonia. The more electrons lost, the greater the negativeaffinity, this being shown by the fact that the cobaltic hexamminesare more stable than the cobaltous hexammines, and that cuprouschloride only combines with three molecules of ammonia, whilstcupric chloride combines with six molecules of ammonia. Ingeneral, three types of chemical combination are recognised.(1) Combination due to the saturation of primary affinity oiily,which gives strong electrolytes.(2) Combination due to the saturation of secondary affinity only,which gives molecular compounds (polymerisation, etc.).(3) Combination due to the saturation of both primary andsecondary affinities, which gives non-polar compounds, such asinethane and carbon tetrachloride.Positive and negative affinity are defined as the tendency tolose or gain electrons.Secondary affinity is that which is developedwhen the primary affinity has come into play. The above threecategories only represent extreme types, and most compounds takeup intermediate positions between the three extremes.l o S. H. C. Briggs, T., 1917, 111, 253; A . , i i , 254.REP.-VOL. XIV. 34 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Colloids.Heference was matle in last year's Report to a very intei-ehtingexperimental method of cleteimiuing the condition in which waterexists in certain inorganic hydrogels, more particularly precipi-tated silica, alumina, and ferric hydroxide.71 The water exists inone of three conditions, namely, free, combined, or capillary water.The method employed is to cool the gel under light petroleum ina dilatometer and t o observe the volume changes as the tempera-ture is lowered.As was pointed out, the free water freezes sharplyat - 6 O , whilst the capillary water slowly freezes as the tempera-t a r e falls, and the combiiietl water, of course, is without effect. It'the free and capillary water can be determined and the total watercontent is known, the combined water can a t once be found bydifference. Some further most interesting results have beenpublished which merit a description in some detail, the object ofthe extended observatioiis being the more accurate determinationof the combined water in the three hydrogels mentioned.Thegeneral method of investigation is simple. I n the case of freewater only, such as is realised by wet sand, the dilatometer read-ings show a steady diminution in volume as the temperature fallst o -6O, when there is a sudden expansion due t o the freezing ofthe water. Further cooling causes a contraction, which is a linearfunction of the temperature. If the dilatometer is now againallowed slowly to return to the ordinary temperature, the originalreadings are recovered. That is to say, the cooling and heatingcurves are identical a t - 6 O and below.On the other hand, ifcapillary water is present, this is not frozen a t - 6 O , but graduallyfreezes as the temperature is reduced. The result is t h a t the cool-ing curve below - 6 O is not a straight line, but is concave t o thetemperature axis. It is possible to recognise the point. a t whicht h e capillary water is all frozen by the cooling curve becoming astraight line. I f the whole of the capillary water is frozen bycooling a t - 7 8 O and the temperature of the dilatometer thenallowed slowly to rise, the first portion of the heating curve islinear. If this straight portion be extrapolated up to the tempera-ture of -6O, the amount of capillary water is estimated from thedifference between this extrapolated line and the cooling curve at,- 6 O .The free water is calculated from the expansion originallyobserved a t -6O.Three samples of precipitated aluminium hydroxide were used,11 H. W. Foote and B. Saxton, J. Amer. Che?n. h'oc., 1016, 38, 688 ; A . ,1916, i i , 230. la Ihid., 1917, 39, 1103; -4., ii, 364INORGANIC CHEMTSTRY. 35one which had been cligestetl with a large excess of water fortwenty-four hours a t looo, whilst the other two had not been 90heated, and differed merely in the length of time they had beenkept. The first sample was exposed to the air until it was onlyslightly moiBt, and was then found to contain no capillary waterand 36 per cent. of combined water. The other two samples con-tained a little capillary water and 37.8 per cent.of combined water.The compound Al(OH), requires 34.6 per cent. of water, and theexcess of combined water must be in solid solution.The case of ferric hydroxide is more complex, for in general*,here is some uncertainty due t o the presence of capillary water,which freezes only a t very low teinl)ei*atures. The combinedwatei., foiind after heating the hycliwsitle with water at 100° fortwenty-four hours, corresponds with the einpirical formulaFe,0,,2*4H20. After three days’. heating, the combined water fellt o the amount corresponding with the empirical formulaFe20,,0.53H,O. After twelve days’ heating, it was necessary toadd a few drops of ammonia, so as to coagulate the gel, whichthen had the formula Fe,0,,1*04H20. I n this case, the repre-ci p i t a t i on 11 n doubted 1 y increased the combine ti water , whichhappens t o be close t o one molecule.Evidently the combinedwater is slowly given off, when the precipitate is heated with water,with no tendency towards simple ratios between oxide and water.It is difficult t o avoid the conviction t h a t no well-defined compoundof precipitated ferric oxide and water exists containing more than0.6 mol. of water. When once dehydrated to this composition, thematerial shows no tendency t o take up water. The evidence allpoints to a combination between ferric oxide and water in jiidefiiiiteproportions, which is essentially a case of solid solution.The results with silicic acid which has not been heated givefairly constant figures, the combined water amounting to a littlemore than 30 per cent.(approximately Si02,1.5H,0). On digest-ing with water a t looo, the ainount of combined water. decreasesuntil, after seven days, it reaches 23 per cent. (SiO,,H,O). Againthe results point t o indefinite combination, t h a t is t o say, solidsolution.A number of papers have appeared tlescyibing the preparationof inorganic colloids, and of these a few present considerableinterest. One of these contains an extension of the nucleus methodfor the preparation of hydrosols, more particularly those of gold.’?Solutions of colloidal gold, which are very uniform in size of theirparticles, may be obtained by bhe use of solutions containing goldnuclei, prepared by the reduction of slightly alkaline solutions ofl 3 R.Zsigmondy, ZeifscA. cil>orv. Phent., 1917, 99, 105 ; A . , ii, 364.c 36 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.gold with phosphorns. These nuclei grow by deposition, and thenumber of particles is determined by the quantity of the nuclearsolution used. The spontaneous formation of nuclei may be sup-pressed, without hindering the growth, by the addition of ammonia,potassium ferrocyanide, or potassium ferricyanide, whilst thegrowth may be diininished, without appreciably altering theformation of nuclei, by the addition of alkali haloids, hydrogensulphide, or colloidal sulphur. A second method of procedure isto use a solution in which the growth is so rapid t h a t the supplyof gold is exhausted before the spontaneous formation of nucleihas become appreciable.Using water which has been distilledfroin potassium permanganate with a gold condenser, and addingthe nuclear solution to the gold chloride before adding the hydr-oxylamine hydrochloride, with or without alkali carbonate, veryclear, deep red solutions are obtained in which the number ofparticles is strictly proportional to the volume of the nuclear solu-tion used. Blue solutions are obtaiiied when a larger quantity ofal&ali is used. Similar results are obtained with hydrazine, theaddition of alkali being then unnecessary. These results havei n d epe n de n t 1 y b ee n confirmed .I 1Some workIj>lC has been carried out recently on the oxidationreactions with solutions of potassium dichromate and potassiumperinanganate in the' absence of acid.The reactions studied arethose between stannous chloride and potassium dichromate, ferroussulphate and potassium dichromate, ferrous sulphate and potassiumpermanganate, ferrous chloride and potassium permanganate, andin general the stoicheiometric relationships are the same as thoseobtained in the presence of acid. When potassium dichromate isadded in the theoretical quantity to a solution of stannous chloridein the absence of acid, brown and greenish-blue gelatinousmasses are formed, which dissolve to form a clear, deep olive-greensolution when the whole of the potassium dichromate has beenadded. These solutions, which appear red by transmitted light,contain potassium and chromium chlorides, together with colloidalsolutions of hydrated stannic and chromic hydroxides.Ondialysis, a clear solutioii of the approximate compositionCr20a, 6Sn0,is obtained, and this sol contains the whole of the tin aiid ab2utone-half of the chromium used in the reaction.I n the oxidation of ferrous chloride by potassium permanganate1 4 J. Reitstiitter, Koll. Chem. Reihefte, 1917, 9, 221 ; A . , ii, 451.1 5 Bi. Neidle and J. C. Witty J . Amer. Ckem. SOC., 1915, 37, 2360; A . ,16 M. Yeidlt and J. N. Crombie, ibitl., 1916, 38, 2607 ; A . , ii, 93.1915, ii, 780 ; ibid., 1916, 38, 47 ; A . , 1916, ii, 256INORGANIC CHEMISTRY. 37tl!e collateral oxidation of the chloride ion is practically avoidedby adding the permanganate gradually and stirring the solutionvigorously.The products of the reaction are the chlorides of man-ganese, potassium, and ferric iron, together with colloidal hydratedferric oxide. When ferrous sulphate is substituted for the ferrouschloride, the corresponding sulphates are formed and also hydratedferric oxide, which is precipitated by the sulphate ion. One grani-equivalent of potassium permanganate, dissolved in about 600 C.C.of water, was slowly added t o one gram-equivalent of ferrouschloride, dissolved in about 1 litre of water, and the resulting clear,deep brownishred solution diluted t o 2 litres. This solutionremained perfectly clear for several weeks, then gradually becamemore and more turbid, until finally a suspension separated. Untiltliis stage is reached dialysis yields a perfectly clear, brownish-redhydrosol of hydrated ferric oxide.After the suspension has settled,dialysis gives a hydrated ferric oxide hydrosol, which is slightlyturbid in reflected light, but perfectly clear in transmitted light.The turbidity which appears on standing is due to the hydrolysisof tlie ferric chloride. The ferric ion protects the colloid againstprecipitation by the manganese and potassium chlorides. Hydro-lysis of the ferric chloride decreases the concentration of the ferricion, and, when this is reduced below the value necessary for pro-tection, the colloid coagulates. This coagulation is, however,reversible, f o r the turbid mixture on dialysis yields a sol that ispractically clear.Methods have been described for the rapid preparation of thehydrosols of ferric, aluminium, and chromic hydroxides by dialysisa t 75-80.17 The solution in a beaker is kept a t the required tenl-perature by a srnall flame, and a parchment bag is suspended inthe hot liquid.This bag is made by tyiiig the membrane to theflanged end of a glass tube, and a current of water througll tliisbag is rnaiiitaiiied continuously. A general method for the prepara-tion of the sols is to dissolve the freshly precipitated hydratedoxide in a solution of the chloride and t o dialyse this mixture. Inthe case of aluminium and chromium hydroxides the solutions maybe dialysed a t once when hot, but, if it be desired to prepare thoclear, brownish-red sol of hydrated ferric oxide, the solution nlustfirst he dialysed iii t'he cold uiitil 110 more iroil passes through tllsmembrane.The t8emperature iitay then be raised to 80° or even t othe boiling point without affecting the iiature of the colloid. Tfthe solution is heated a t the commencement of dialysis the yellowochre variety of colloidal ferric oxide will be formed. It is foundmore convenient in preparing tlie solutioii t o add ammonia to tlie1: 11. Xeidle and J. Barab, J . Amer. Chein. Soc., 1017, 39, 71 ; A., ii, 26338 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.clilorides in insufficient amount to forin a permanent precipitate ofthe hydroxide. I n this way better yields of the colloids areobtained and their solutions are clearer.It was found t h a t colloidal cliromic and aluminium hydroxidespass through the membrane to a certain extent, so t h a t the yield isconsiderably smaller than theory would predict.The actual yieldsobtained were : Fe(OH),, 89.9 per cent. ; Cr(OH),, 53.3 per cent. ;Al(OH),, 41.3 per cent,. As regards tlie time taken in tlie pre-paration of these sols by dialysis of hot solutions, it was shown, forexample, t h a t the purity of the chromic hydroxide sol obtained bydialysis of the boiling solutions in ten hours is greater than thatobtained by dialysing a similar solution for seventy-three days a tt 11 e ordinary temper a t ur e .Iridium hydrowls 18 can be prepared by reduction of alkalilieiridium solutions with hydrogen, hydraziiie hydrate, sodiumforinate, or forinaldeliyde in presence of sodium protalbate orlysalbate as protected colloid.A clear solution of iridium chlorideobt,ained by the addition of hydrogen chloride is added to a solutionof tlie protective colloid when rust-brown or olive-green precipi-tates of the protalbate or lysalbate are produced, the colour beingdependent, apparentlS;, on the amount of free hydrochloric acid.These precipitates dissolve in sodium carbonate or hydroxide toform the blood-red hydrosols of iridium triliydroxide. Witl1 a11excess of sodium hydroxide the sol becomes oxidised on exposureto air, giving the blue hydrosol of iridium tetrahydroxide. If tliesol with sodium lysalbate as protective colloid is acidified, some ofthe lysalbic acid is left in solution and the gel is thereby eiiricliedin iridium.By redissolving this in sodium hydroxide and repeatingtlie process a few times, a so1 may be obtained wliich, on drying,coiitaiiis as iiiucli as 73 per cent. of iridium.C;I.olrp I .Ail iiiterestiiig series of papers lias beeii published 011 tlie titra-tioii of the phosphoric acids and tlie constitution of the alkali inetalpliospliates.19 It is well known t h a t the neutral point obtained intitrating phosphoric acid with alkali differs with the indicatorused, i t being believed that sodium dihydrogen phosphate is neutralto metliyl-orange aiitl that tlisodiunl Iiydrogen phospliate is neutralto ~)heiioll,litlialeiii. It is fouiid, however, if the titratioii is carrieduut, a t the ordinary teniperatiire, that this is far froiii correct. 0 1 1the other l i a ~ i ( l , t lie values obtaiiierl iii the titratioii vary consider-ably witli the teiiiperatiir~, a i l ( ] i t is shown that a t a temperature1 8 c.‘.Pnal, Be,.., 1917, 50, i 2 2 ; -.I., ii, 375.l9 J. H. Smith, J . &“oc. Cliem. Iiztl., 1917, 36, 415 ; d., ii, 3091NORGANIC CHEMISTRY. 39of 55O the neutral points observed agree very closely with thequaxtitative formation of the two salts, sodium diliydrogen phos-phate and disodium hydrogen phospliate. A method of volumetricaaalysis was devised, by means of which it is possible to calculatethe percentages of practically all the phosphoric acids and theirsalts, t h a t may exist together in a compound, including the c a r h n -ates and the free alkali that niay be present with them.The appli-cation of this method to tlie analysis of ordinary commercial plios-phates has led t o an investigation of the alkali metal phosphates.A specimen of ordinary sodium phosphate was found to containNa,HPO, = 38.02, Na,PO, = 2.41, H20 = 59.5'7, whilst theory re-quires- Na2HP0, = 39.64 per cent. Some clear crystals of trisodiumplicjsphate contained Na,PO, = 41.90, Na,O = 2-01, Na,C03=0*66,H,O = 55.43, whilst theory requires Na3P0, ~ 4 3 . 1 3 , H20 = 56-87per cent.It might be assumed that in preparing disodiuni hydrogen phos-phate, if the theoretical amount of ortliopliosphoric acid and sodiumhydroxide were brought t'ogether in solution, there would be nodifficulty in obtaining the pure crystallised salt.This was found,liowever, iiot to be the case, and crystallisation can oiily be inducedby the addition of a few crystgals of the commercial salt. An analysisof the product slio~7ed t h a t i t has a niolecular composition of93.93Na2HP0,,G.07Na,P0,.. In the second preparation when thecrystals were dried a t l l O o , the composition was94.5Na,HP0,,5'5Na3P0,.Coininercial disodium hydrogen pliospliate has a siniilarcoiuposition wliicli approxiinates t o 1 7Na,HP04,Na,P0,. Crys-tals can also be obtained with a greater proportion of Na,PO,, andtlie following have beeii identified : 8Na,HP0,,Na3P0, ;GNa,HPO,,Na:,PO,;3Na,HPO,,Na,PO4 ; 3Na2HPO,,2Na,I'O,.I n the case of sodium diliydrogen phospliate, it is possible t oimpare this salt in a pure state by bringing t,ogetlier the theoreti-cal aniouiits of orthophosphoric acid aiid sodium hydroxide antiby conceiitratioii of the resulting solution.Difficulties were also found in the preparation of trisodiuin phos-phate.011 bringing together the theoretical proportions of acidaiid alkali. hydroxcle, followed by considerable concentration, crys-tsls are obtaiiied having a constitution Na,HP0,,2Na3P0,. Theiiiother liquor, on further coiicentration, gave crystals of the coin-position 18Na3P0,,Na,0, tlie water content in each case not beingdetermined. By using a slight excess of sodium hydroxide overthe amount required by theory, the crystals \?rliich first separateIiave tlie conipoeitioii 1 7*5Na3P04,Na20, and it is believed t h a t th40 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.correct molecular composition of this salt is represented by1 8Na3P04,Na,0.A new phosphate of sodium, Na,P,O,,, is also described, contain-ing a much higher proportion of acid oxide than is represented bysodium dihydrogen phosphate or metaphosphate.The new salt isreadily prepared in an impure state by evaporating mixtures ofsodium hydroxide o r carbonate with phosphoric acid in sufficientexcess, and igniting the residue. Any excess of the acid is vola-tilised during the ignition, so that the proportion of acid is thehighest with which sodium oxide is capable of combining to form asalt stable a t a red heat. The salt forms a fused, glassy mass,which dissolves slowly in cold and more readily in warmwater.The solution is nearly neutral t o both methyl-orange andphenolphthalein. On prolonged boiling with water, it is convertedinto sodium metaphosphate and free orthophosphoric acid. I n thepresence of free mineral acid sodium orthophosphate is formed.A remarkable property of this salt, t o which the name of sodiumpolyphosphate is given, is its exceedingly energetic corrosive actionoil glass, porcelain, and even platinum and silica vessels. Thisaction is, naturally, most pronounced a t the high temperature offusion, when the glaze of porcelain vessels is readily attacked. Silicavessels are also sensibly attacked, and silica enters into the coni-position of the resultant salt. A platinum vessel was stronglyattacked, becoming brittle in the places where i t had been in con-tact with the fused salt.I n the case of a nickel vessel the residueconsisted entirely of a mixture of sodium and nickel pyrophos-phates. This conosive action renders iZ, almost impossible toprepare the salt in a pure condition.Some further work may be noted on silver peroxynitrate,ZO whichhas been the subject of very many investigations in the past. Whenan aqueous solution of silver nitrate is electrolysed betweeninsoluble electrodes, silver is deposited a t the cathode and silverperoxynitrate a t the anode, there being presumably a simultaneousformation of nitric acid. Both deposits are crystalline, and theygrow rapidly towards one another in arborescent crystals. Theanode crystals soon become detached, and they are then attackedhv t'he free nitric acid and pass into -olution with the liberationof gas.The composition of these crystals is doubtful, m.any viewshaving been expressed. Experiments are now described in whichthe electrolyte is kept in continuous circulation, and the decom-posing action of the nitric acid is avoided by means of suspendedsilver carbonate. Two strengths of solution were used, namely,one containing 5 per cent. and the other 20 per cent. of silver2 O M. J. Brown, J. Physica,l Chew, 1016, 20, 6SO ; A . , ii, 88INORGANIC CHEMISTRY. 41nitrate. The percentage of silver in the compound varies from79.03 t o 79-82, and the coulometer ratio of the compound to copperdeposited in the same circuit varies from 2.98 to 2.69, but there isapparently no relation between t>lie fluctuations in the coulometerratio and tlie silver content.The compound cannot be a pure oxide,because the oxides up t o Ag,O, have too high a silver content, andAg,O, has far too low a coulonieter ratio; neither can it be ahydrated oxide of definite composition. The determinations agreewith the formula 2Ag,0,,AgN03, which requires 79.9 per cent. forthe silver content and 2-97 for the coulometer ratio. The smallcliff erences between the calculated and observed values are probably(1 11 o to secondary dist,urbances.In the rlrytlimical precipitation of silver chroinate by means ofaiiimonium clichromate the small crystals of ammonium nitrate,which also separate rhythmically, are coloured by silver chromate,being yellowish-green t o red, according to the concentration.2lSimilar coloured crystals are obtained when a solution of ammoniuinnitrate containing a little ammonium dichromate is mixed with a.drop of silver nitrate and allowed t o evaporate on a glass slide.Both silver chromate and dichromate can take small quantities ofammonium or potassium nitrate into solid solution.The colour ofpure silver chromate is always greenish-black, and the red sub-stance usually supposed to be a separate modification is a mixtureof silver chromate and the solid solutions with the nitrates.Certain double fluorides of rubidium and czesium with the metalsof the fourth group have been prepared and examined.22 Thegeneral method is to add the alkali carbonate to a solution of thequadrivalent metal oxide in hydrogen fluoride, but in tlie case oflead the solution of the acetate in hydrogen fluoride was used.Theresulting solutions give characteristic crystals of the double saltsOYI being allowed to remain. The following salts are described:Rb,SnF,, Cs,SnF,, Rb,PbF,, Cs,PbF,, Rb2GeF,, and Cs,GeF,.Yotassium stannichloride can conveniently be prepared by theoxidation of the stannochloride by means of chlorine.23 A concen-trated solution of the salts in tlie molecular proportion of two partsof potassium chloride and one part of stannous chloride is preparedwith the addition of a few drops of concentrated hydrochloric acid.A slow stream of chlorine is passed in for about three hours, whentlia solution is treated with a little concentrated hydrochloric acidand slowly evaporated a t 50-70° for about two hours.After sometime crystals of the staniiichloride separate out. The method was2 1 F. Kohler, Zeitsch. anorg. Chem., 1916, 96, 207 ; A., ii, 32.22 A. Xkrabal and J. Gruber, Monatsh., 1917, 38, 19 ; A . , ii, 263.23 J. G . F. Druce, T., 1917, Ill, 416; A . , ii, 309.C42 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYtmted with mixtures of potassium chloride and manganese chlorideand of potassium chloride and lead chloride, but wit,hout success.Group I I .The melting point of glucinuni has been determined and fount1t o be 127S0+ 5°.21 The element, prepared electrolytically fromsodium glucinum fluoride, was pressed into pastilles and fused in amagnesia tube in hydrogen.The product contained 99.5 percent. of glucinum, the principal impurity being the carbide. Themelting point was found from the heating and cooling curves. Anapproximate determination of the heat of fusion gave 277 cal.per gram.The literature contains many references to the preparation andproperties of zinc peroxide and its hydrates, and some furtherwork is to be added t o the list.25 The addition of a solution ofzinc sulphate to excess of a solution of sodium hydroxide containinghydrogen peroxide gives a quantitative precipitation of the zinc ashydroperoxide. A more convenient method was found to be asfollows. Freshly ignited pure zinc oxide was left for several hourswith the calculated quantity of 30 per cent.hydrogen peroxidesolution a t -loo. A product was obtained which above 2O formeda pasty mass, and when dried on a porous plate a t 35-40° oversoda-lime was obtained as a white powder. It contained 8.04 percent. of active oxygen and corresponded almost exactly with thecomposition 2Zn0,Hz02 o r Zn,O<gzH. Towards water, alcohol,or ether a t the ordinary temperature i t is quite stable, and is onlyslowly decomposed by 2N-sodium hydroxide. It does not appear,however, to be a simple chemical individual, since by triturationwith water it can be separated into fractions containing varyingquantities of active oxygen. Similar products are obtained byboiling zinc carbonate with excess of 30 per cent.hydrogen peroxides 01 u t ion.It is concluded t h a t zinc perhydrate generally consists of a mis-ture of substance5 derived from Zn(OH), and O(ZnOH),, the hydro-peroxides being of the types OH*Zn*O*OH andZn(OH)*O*Zn*O*OH.By a study of the equilibrium relations in the ternary systemformed by the alkaline earth metal haloids, the corresponding hydr-oxides, and water, certain basic haloid halts of these metals havebeen investigated.26 The basic salt, CaI,,3Ca0,16H20, is stable in24 G. Oesterheld, Zeitsch. anorg. Chem., 1916, 97, 1 ; A . , ii, 89.25 F. W. Sjostrom, ibid., 1917, 1 0 , 237; A . , ii, 533.2 6 J . Millikan, Zeitsch. physikal. Chem., 1917, 92, 59 ; A . , ii, 257INORGANIC CHEMISTRY. 43contact with soliitions containing from 28.44 t o 66*68 per cent.cfcalcium iodide. The only basic chloride of otrontium has thecomposition SrCl,,SrO,SH,O, and this only exists in contact withsolution at, temperatures above 2Ci.5O. Strontium bromide andstrontium iodide respectively form the two basic salts,8rBr2,Sr0,9H,O and SrI,,2Sr0,9H20.The basic phosphates of calcium have also been studied by asimilar method, this work being tlte fourtli contribution t o ourknowledge of the calcium phosphates by the same author.27 Thepresent investigation deals with the region lying between thosewhich are characterised by tlie existence of dicalcium hydrogenphosphate and calcium hydroxide as stable solid phases, and theobservations were made a t 2 5 O , looo, and 170---200°. Two, andonly two, phosphates of calcium more basic than dicalciuni phos-p1iat.e exist, which can be in stable equilibrium with an aqueoussolution ht.2 5 O and, probably, a t any temperature. Tliese are tri-cal c i u rn phosphate , Ca sP,08, aiid h y d r oxy a pa t i t e,There is no evidence for the existence of phosphates between dical-cium hydrogen phosphate and tricalciuin phosphate, or of theformation of solid 29 Hydroxyapatite is the only stahIesolid phase over a range of acidity of great practical importance, asi t can exist in contact with faintly acid, neutral, or alkaline solu-tions. It is probable that this compound is the only calciiim phos-phate t h a t can permanently exist under normal soil conditions.The importance of hydrosyapatite is obvious in relation to thenature of bone phosphate, and this is considered to be a mixture ofhydroxyapatite and calcium carbonate with small amounts ofadsorbed bicarbonates of sodium, rotassium, aiid magnesium.A study has also been made of the ternary system CuS0,-CuO-€I,O with the object of ascertaining the cause of the varying com-position of the mineral brochantite.30 Series of observations weremade a t 2 5 O , 3 7 .5 O , and 50'. and it was found that in all proha-bility the solid basic substances obtained are not definite com-pounds, but are rather t o be regarded as a tliree-component systemin wliich all three components (CuSO,, CuO, H,O) are continuouslyvariable within certain limits. The maximum number of moleculesof CuO that can be taken up by one molecule of CuSO, is two, andthe formula for the most basic salt is probably CuS0,,2Cu0,2H20.2 7 H.Bassett, jun., Zeilsclt. at2os.g. Chem., 1907. 53, 34, 1 9 ; 1908. 59, 1 ;A., 1908, ii, 676 : T., 1917, 111, 620 ; A., ii, 413.2 8 F. K. Cameron and A. Seidell, J. Amer. Chem. SOC., 1905, 27, 1503 ;A., 1906, ii, 163.2 9 F. K. Cameron and J. 11. Bell, ibid., 15522; A., 1906, ii, 164.3 0 S. W. Young and A. E. Steam, ibid., 1916, 38, 1947 ; A., 1916, ii, 621.(Ca3P,O&,Ca(OH)2*c" 44 ANNUAL REPORTS ON THE PROGRESS OF CHEMIS'I'RT.I n general, the experiments indicate the existence of a series ofmetastable sulphates, and go to show that i t is t o be expected t h a tbrocliantite would evidence variable composition according to theconditions of its for ilia t ion.of purerecrystalliserl catliniu~n cliloride anti silver nitrate in a mortar,water being added from time t o time until the filtrate gave noindication of excess of either of tlie parent substances.On evapora-tion in a vacuum over sulphuric acid, bright pale yellow crystalswere obtained with the composition Cd(NO,),. On heating, thissalt begins t o decompose slowly a t 1 5 0 O . As nitric oxide is tlie chiefga5eous product, the main portion of the salt evidently decomposesaccording t o the equation 3 C ~ l ( N 0 ~ ) ~ = 2CdO + Cd(NO,,),i- 4N0,siiice the brown residue was found to be cadniiuni nitrate mixedwit ti cadmium oxide. A parallel decompositioii also takes placeaccording to the equation Cd(NO,), = CdO 3- NO + NO,.The solu-tion obtained by the interaction of zinc sulpliate and bariumnitrite evolves nitric oxide when concentrated by evaporation , andtlie residue consists of basic zinc nitrate.Tlie compound, gluciiiiim metavanadate,sz G1(VO3),,4H2O, hasbeei! prepared by boiling equiinolecular solutions of glucinum hydr-oxide and vanadium pentoxide with water for about one hour, afterwhich the solution was filtered and concentrated. This, while hot,wau poured into a large volume of 95 per cent. alcohol, when acopious deposit of yellow particles was produced, which in twenty-four hours had settled to a voluminous layer of yellow crystals.The salt is sparingly soluble in cold water, but readily so in hot.water. It is practically insoluble in chloroform, ether, o r absolutealcohol, but is soluble in pyridine to about the same extent as inwater. The crystals lose the whole of their water of crystallisationover sulpliuric acid.( 'adiiiiiini iiitrite :iI lias been 1)reparetl by triturationGroup 111.An alkaline solution of gallium hydroxide in sodium hydroxide,on electrolysis a t the ordinary temperature, u s d l y depositsgallium as liquid globules on the cathode.It is found, however,t h a t such a solution, after separation of the indium, on electrolysisa t Oo, deposits the nietal in black, arborescent forms.33 Thesegallium trees are hard and are permanent so long as they are kepta t a temperature loo below the melting point. Although black31 P. C. R$y, T., 1917, 111, 159; A ., ii, 208.32 P. H. M. P. Brinton, J . Amer. Chem. SOC., 1916, 38, 2361; A . , ii, 32.33 H. S. U1Jt.r and P. E. Browning, Amer. J . Sci., 1916, [iv], 42, 389;A . , ii, 34INORGANIC CHEMISTRY. 45in external appearance, they present, when cut, the usual silverylustre of pure gallium. When placed in water, gas is slowlyevolved, and the metal becomes coated with black, grey, and whitepatches. A specimen of electrolytic gallium coiitaining a traceof zinc was purified by heating the metal in a current of dryhydrogen a t a dull red heat, when the whole of the zinc sublimetl.The separation of gallium from indium may be effected (i) bysolution of gallium hydroxide from the mixed hydroxides by sodiumhydroxide, (ii) by crystallisation of the ammonium alums froiii'TO per cent.alcohol, and (iii) by crystallisation of the caesiumalums. A gallium preparation containing 10 per cent. of indium,with traces of zinc, copper, and lead, was practically pure afterten crystallisations of the caesium alums.A continuation of the investigation of the action of acids onaluminium may be noted.34 The previous experiments 35 dealt, withnitric acid, and the new investigation deals with acetic acid a tvarying concentrations and temperatures. The aluminium, con-taining Al=99*1, Si=0*45, Fe=0*43 per cent., was used in theform of thin, rolled strips, which were generally anilealed beforeuse. The surface of the metal was cleaned with sodium hydroxideand washed with dilute nitric acid before each experiment.I n the case of boiling dilute acid, the rate of dissolution risescontinuously until the concentration of the acid falls to 1 per cent.The dissolution is greatly affected by the products of the inter-action, the disturbance growing very rapidly with increasing dilu-tion. A definite reason cannot yet be assigned, b u t it has beeiifound that acid which has become highly active can be distilledwithout losing its activity. Solutions of acid which have beenboiled in contact with aluminium become turbid after a period,and the nature of the turbid solutions varies in the different cases.With acids of concentration between 60 and 5 per cent., theturbidity appears to be due to the separation of basic acetate oracetates of aluminium. I n the case of acids of about 0.2 per cent.concentratmion, the turbidity may be due to the formation of acolloidal solution of aluminium hydroxide. Solutions containingbetween 5 and 0.2 per cent.of acetic acid yield turbid solutionsof ail intermediate character.Except in the case of the anhydrous acid, aluniiniurri is uniformlyattacked by boiling acetic acid a t all concentrations, no evidenceof local action having been observed.I n general, aluminium is only slowly attacked by cold aceticacid, the rate of dissolution increasing with increasing dilution of31 R. Seligman and P. Williams, J . SOC. Chewt. I I L C ~ . , 1917, 36, 409 ; -4.,ii, 317. 3 5 Ibid., 1910, 35, 865; A , , ii, 43546 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYthe acid, the highest rate so far observed occurring with all aci(1coutaining 0.03 per cent.acetic acid. The rate is frequently higha t first, but rapidly falls, and then remains constant over loiigperiods. I n most cases the attack is uniform, b u t local action hasbeen observed a t concentrations between 70 and 95 per cent,., andin cases in which the metal has been allowed to remain in contactwith thin films of dilute acid, which have thereby become subjectedto extensive aeration.The action of boiling acetic acid, (about 10 per cent.) onduiniiiiuin is practically unaffected by the addition of up to 1 percent. of sodium chloride, potassium bromide, iodide, or nitrate,whereas an equivalent amount of sodium sulphate raises the rateof dissolution appreciably. With the cold acid, on the other hand,the rate of dissolution is increased tenfold by 1 per cent of sodiumchloride, whereas potassium bromide affects a smaller increase, andpotassium iodide and nitrate are without action; 0.5 per cent.ofsodium sulphate causes a fourfold increase in the rate of dissolu-tion. The most serious effect of the addition of substances wasnoted in the case of the boiling 80 per cent. acid. Here the rateof dissolution is raised by 1 per cent. of sodium chloride from 390to 16,000, by 1 per cent. of potassium bromide the rate is onlyinFreased from 290 to 485, whilst potassium iodide and potassiumnitrate are practically without effect. Sulphuric acid (0.5 percent.) in the for? of sodium sulphate somewhat increases the rateof dissolution.In the Report for 1913, refereiice was made t o the existence ofborohydrates which possess very interesting properties.36 Somefurther work has been carried out on these substances and maybriefly be described, especially as some of the original conclusionshave been modified.37 The new experiments show t h a t when amixture of 2.25 parts of inagnesiuin powder and 1 part ofanhydrous boric acid is heated in a current of hydrogen until thereaction is complete, solutions are obtained by treatment of theproduct with water which are free from boric acid and magnesiumborate, and contain only substances which are described as boro-hydrates.The main product of the action of water is an insolublecompound of magnesium oxide with a borohydrate, reaction takingplace in accordance with the equationMg,B, + 6H20 = Mg,B,(OH), + 3H2.The soluble borohydrates and gaseous coinpounds of boron and3G M.W. Travers and R. C. Rey, Proc. Roy. SOC., 1912 ; [A], 87, 163 : &4.,1912, ii, 938.37 M. W. Travers, N. 31. Guptn, and R. C. Rey, Pamphlet, 1916, p. 46 ;A . , ii, 307I N ORG A N I C CH EM IS'VRY. 47hydrogen, which are also formed, are attributed to secondaryreactions.The solutioiis of borohydrates are unstable, but the stability isincreased in presence of traces of ammonia. On the addition ofacids to the solutions, hydrogen is evolved, and the acid solutionsdecolorise iodine Analyses and molecular weight determinationsindicate that the mean coinposition of the borohydrates is repre-sented by H,B,O,.When the solutions are evaporated to drynessand the residue heated, a mixture of the oxide, B20,, with mag-nesium oxide is obtained.If the mixture of magnesium boride and boric acid is insuffici-eiitly heated, or if excess of boric acid is employed in preparingthe mixture, the solutions obtained by the action of water differfrom those described above in that they contain magnesium borateand boric acid, as well as one or more borohydrates.When magnesium boride, after prolonged treatment with water,is acted on by strong ammonia, a solution is obtained which doesiiot lose hydrogen when kept in an exhausted tube and does notoxidise in contact with the air. On addition of acids to this solu-tion, hydrogen is rapidly evolved, and the acid solution reacts withiodine.When the solution is evaporated t o dryness a t low tempera-ture in a vacuum, a white, crystalline residue remains, which givesoff hydrogen when heated and is transformed into the oxide, B40,.This oxide dissolved in water with the formation of a yellow solu-tion, which rapidly absorbs oxygen in contact with the air, thereaction being represented by the equation2B,O, j- 0, + 12H20 = 8B(OH),.Molecular weight determinations of the substance in theainmoniacal solution prepared as described above seem to showt,hat the compound has the formula H,,B40,,2NH,. Whenammoniacal solutions of the borohydrates are evaporated to dry-ness and treated with water, a small quantity of insoluble residueis left, which appe,ars to be a hydrated derivative of an oxidecontaining less oxygen than those previously referred to.I n discussing the above results, the work of Stock and his pupilsmay be recalled on the hydrides of boron obtained by the actionof acid on magnesium boride.This work was described a t somelength in the Reports for 1912, 1913, 1914, and 1915.An improvement in the method of the preparation of carbonsuboxide has enabled this gas to be prepared in l a r p quantities,with the result that the physical constants have been determine48 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with greater accuracy than has previously been possible.38 Thepoor yields usually obtained by the action of phosphoric oxide onmalonic acid are largely due to the polymerisation of the suboxideunder the catalytic action of the phosphoric oxide.If the sub-oxide is removed rapidly by carrying o u t the reaction in a goodvacuuni and condensing the product by means of liquid air, avolume of the gas corresponding with as much as 25 per cent. ofthe malonic acid can be obtained The melting point of carbonsuboxide is -111.3O and its boiling- point Go, and the vapourpressure a t Oo is 587-589 min. The gas is very readily solublein carbon disulphide or xylem. It is interesting to note t h a t thepolymerisation of the gas t o the red substance, which is soluble inwater, is catalysed remarkably by the polymeride itself. The gasmay sometimes be kept f o r days, but as soon as polymerisationsets in, it completely disappears within a day.I n contact withphosphoric oxide, the gas polymerises within a fraction of a minute.Carbonyl sulphide39 can be prepared by the action of hydro-chloric acid on commercial ammonium thiocarbamate, accordingto the equation NH,*CO*S*NH, + 2HC1= COS + 2NH,Cl. The gasis purified by being bubbled through a 33 per cent. solution ofsodium hydroxide, which absorbs carbon dioxide and hydrogensulphide, after which it is dried by means of calcium chloride andphosphoric oxide; it is then condensed by means of liquid air, andfinally fractionated. The gas is fairly readily soluble in weakersolutions of alkali hydroxide, but only slowly dissolves in a 33 percent. solution. It is odourless and is slowly decomposed by water,but in the dry state it is permanent even in sunlight.One partof water dissolves 0.54 vol. a t 20°, and one part of alcohol andone part, of toluene a t 2 2 O dissolve 8 vols. and 15 vols. respectively.It has D-87 1.24, m p. -138.Z0, b. p. -50*2°/760 mm.A considerable amount of work has been done on zirconiumdioxide and zirconium salts. The possibility of the use of thedioxide as the basis of glazes for metal ware and of scientificapparatus has long been recognised. As regards its use in makingapparatus, difficulties have been found in t h a t cracks readilydevelop in the finished articles. If, however, the dioxide is firstinelted a t a very high temperature and the solidified fusion finelyground, the powder so obtained can be used for making apparatussimilar to porcelain ware, for the apparatus is perfectly souiid andtloes not develop cracks.The nielting point of pure zirconiuiridioxide is about 3000°.403 8 A. Stock and H. Sboltzenberg, Ber., 1917, 50, 498; A , , ii, 308.39 A. Stock and E. KUSS, ibid., 150 ; A . , ii, 305.do E. Podszus, 8eitwhG angew. C h e i ~ . , 1017, 30, i, 17 ; A . , ii, 48QJ NORG ANIC CHEMISTRY. 49Other experiments have been made on the fusibility of mixturesof zirconia with other oxides.41 Zircoiiia containing 98-73 per cent.of ZrO,, the remainder being SiO, and Fe,O,, melts a t 2563+10°.Glucina, alumina, yttria, and thoria are suitable for addition tozirconia, causing little volatilisation a t high temperatnres, whilstiiiagiiesia causes fuming and silica lowers the me1 ting pointexcessively.For the preparation of crucibles, the addition of1 per cent. of alumina is recommended for use a t 2000°, 1 percent. of thoria for use a t 2200°, and from 1 to 3 per cent. of yttriafor use a t 2400O. The addition of larger quantities increases theporosity and has no advantage.It appears t h a t the hydrate of zirconium fluoride does notpossess the usually assigned composition ZrF,,3H20, but is reallya hydrate of acid zirconyl fluoride, ZrOF2,2HF,2H,0.42 Thearguments are based on the fact that this compound a t 140° indry air loses 2 niols of water, giving the anhydrous acid fluoride,which when heated above 140° in air loses 2 mols. of hydrogenfluoride, giving zirconyl fluoride, ZrOF,. This compound whencold reabsorbs 2 mols, of hydrogen fluoride.The anhydrous normalzirconyl fluoride may also be obtained by crystallising the hydratedacid fluoride from dilute aqueous solution and drying the pro-duct, ZrOF2,2H,0, a t 120O. If the anhydrous or hydrated acidfluoride is heated a t 200° in an atmosphere of hydrogen fluoride,zirconium fluoride is obtained which, in the cold, absorbs hydrogenfluoride, probably to form fluozirconic acid, H,ZrF,.Somewhat analogous relationships are exhibited between thebromides of zirconium. By the evaporation of a solution ofzirconium hydroxide in hydrobroniic acd on a water-bath, thehydrate of zirconyl bromide, ZrOBr2,8H,0, is obtained. Thiscompound, when dried in a vacuum or in a current of dry air, givesthe hydrate, ZrOBr2,3*5H,O, which is stable u p to 60--7OO.Abovethis temperature, it loses both water and hydrobroinic acid, givingthe compound ZrOBr,,ZrO,. This basic bromide is also slowlydeposited from an AT/ 100-solution of zirconyl bromide on longkeeping. By the addition of ether to an alcoholic solution ofzirconyl bromide, the compound, ZrOBr2,Zr0,,2H,0, is obtained.I n a current of hydrogen bromide a t a red heat, the basic bromideis converted into zirconium bromide, ZrBr,.By mixing varying molecular proportions of zircoiiiuiu oxide aiitlsulphuric acid and drying the products a t 300°, a series of sub-0. Ruff aid C;. Lauschke, Zeitsch. m o r g . c'/wti., 1916, 97, 731 ; A . .42 E. CL1~ur'aii9t, L ' i ~ j z ~ ~ f ~ /*en Z., 1017, 169, 630, 727, 816, 864, 946 ; A , ,ii, 95.ii, 264, 321, 322, 37150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.staiices has been obtained the conipositioii of which, by the methodof densities, appears to be Zr( SO,),, Zr(S04),,ZrOz,5Zr(S04)2,7Zr0,,3Zr(S04)2,5Zr0,, Zr( S04),,2Zr02, Zr(S04),,3Zr0,. It would seemmore probable, however, t h a t these are in reality zircoiiyl sulphates.A new class of basic salts of zirconium has also been described.43A basic sulphat~ of this element, of indefinite composition, is pre-pared by partly neutralising an impure dilute solution of zirconiumsulphate in sulphuric acid with ammonia This basic sulphate isreadily decomposed by aqueous ammonia in the cold, giving ahydroxide readily soluble in acids.By the crystallisation of itssolution in hydrochloric acid, an oxychloride is formed, which isnot a uniform substance.By recrystallisation of this oxychloridefrom hydrochloric acid, i t is separated into two salts, the normaloxychloride, ZrOC1,,2H20, and the new compound, Zr,0,C14,22H20.This new oxychloride is a crystalline salt, very readily soluble inwater, and can be recrystallised unchanged from hydrochloric acidsolution.Soluble sulphates precipitate from solutions of 5 : 4-basiczirconium chloride an insoluble sulphate, Zrj08( S0,),,zH20, whereLC is probably 14. This is a non-crystalline compound, soluble inconcentrated sulphuric acid. Corresponding with the 5 : 4-chlorideand the 5 : 2-sulphate is a hydroxide prepared from either of theseby the action of ammonia.It is distinct from normal zirconiumhydroxide, since, when redissolved in hydrochloric acid, i t formsthe 5 : 4-basic chloride. From analogy, its composition is given asZr,08(OH),. It is suggested that the new salts have structuralformulze of the type Zr(O*ZrO*Cl),, which would account for theirremarkable stability . A basic sulphate is also described, producedby the addition of sulphuric acid to a boiling solution of zirconiumoxychloride. ZrOC1,,8H,O. This appears t o have the same com-position as the 5 : 2-sulphate, although i t is otherwise distincttherefrom. Evidence was also obtained of yet another oxychlorideof zirconium.The very remarkable analogy between the above new salts ofzirconium and those of tin has not been commented on by theauthor.It may be pointed out' that there is a basic chloride oftin, prepared from metastannic acid, H5Sn5015, which has the com-position Sn508C1,,7H20, and is clearly the analogue of the newzirconium oxychloride. A t the same time, the 0-stannic hydr-oxides and chlorides do not appear properly to have been system-atised. Metastannic acid is usually considered to have the coin-position H,Sn5OIl,4H,O, owing to the fact that the metastannatesl 3 E. H. Rodd, T., 1917, 111, 396; A . , ii, 322INORGANIC CHEMISTRY. 51have the coiiiposition M.',SII,O,~,~H,O. This foriii gives rise tothe oxychloride Sn50,C1,,4H,0 (metastaunyl chloride). On theother hand, the oxychloride Sn508C'1,,7H,0 must be derived froma metastannic acid of the composition H4Sn,012,3H,0, and thiswould be the analogue of t h e new zirconium hydroxide. Judgingfrom analogy, therefore, i t would seem that the conclusion thatthe new zirconium hydroxide has the compositim H4Zr,OI2 is f d l yjustified, although perhaps it' may be combined with three mole-cules of water.Again, by boiling metastaniiic acid with water, parastaiiiiic acidis obtained, and the composition of this is usually represented asII,Sn,O1,,2H,O, since it gives an osychloride with the compositioiiSn,O,Cl,,ZH,O.The ratio between tin and chlorine is the sameas in metastaiiiiyl chloride, but the properties of the two oxy-chlorides are different. The suggestion may be made, therefore,that the second new basic zirconyl sulphate is related to the firstin exactIy the same way as parastannyl chloride is ielated to meta-stannyl chloride.A method is described for the preparation of pure bismuth fromtiin, commercially pure metal.44 The nitrate, if already of fairpurity, is dissolved in half its weight of 8 per cent.nitric acid andmixed with an equal weight of the concentrated acid. The crystals,which separate on cooliiig to Oo or -loo, are washed with a littleice-cold nitric acid. All impurities are thus concentrated i n themother liquor. The nitrate is converted into the oxide by heat,ant1 the oxide is then reduced by fusion with potassium cyanide,A further purificat'ion, if necessary, is effected by melting the metaluiider paraffin and removing the first (purest) crystals by means ofa glass spoon.Purified bismuth melts a t 271.0°, and when pressedinto wire a t 195O has a specific electrical resistance of 1-20.Some experiments with nitrogen tricliloride may be noted,together with some investigations of the reactions between chlorineand ammonia."> 46 The nitrogen trichloride was prepared by theHentschel method,47 using, however, carbon tetrachloride as thesolvent in place of benzene. The solution of the trichloride incarbon tetrachloride may be preserved for several weeks in the dark44 F. Mylius and E. Groschuff, Zeitsch. anorq. Chent., 1916, 96, 2.37 ; --I.,45 C. T. Dowell and W. C . Bray, J . Amer. Chenz. Soc., 1917, 39, $96 ; --l.,4 6 W. C. Bray and C. T. Dowell, ibid., 1017, 39, 905 ; 8., ii, 307.*? W.Hentschel, Ber., 1897, 30, 1792 ; .4., 1597, ii, 447.i j , 37.i, 30852 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.before they become greatly contaminated with chlorine from thedocomposition of the tricliloride. Only one reducing agent wasfound, namely, sodium sulphite, which reduces nitrogen trichloridequantitatively to ammonia ; this reaction occurs in accordance withthe equation 3Na,SO, + NCl, + 3H,O = 3Na,S04 + 2HCl-f- NH,Cl.In the case of tlie other reducing agents investigated, some nitro-gen is evolved in a secondary reaction. These were ferrous sulpliate,arsenions acid, sodium arsenite, hydrogen sulpliide, and potassiuiiiiodide in acid solution. Iodine reacts with nitrogen tricliloride,setting free nitrogen and forming chlorides of iodine; on the adcli-tioii of water t o the resulting solution, iodic acid is precipitated.Sodium hydroxide reacts with nitrogen trichloride, giving a rapidevolution of nitrogen, b u t tlie reaction is not quantitative) sincesome ammonia is also formed.Quinol is converted into hexachloroquinol, whilst carbamide inacid solution is not acted on, hut in neutral solution there is a slowevolution of nitrogen.Nitrogen tricliloride reacts slowly withdilute ammonium chloride solution and more rapidly with a con-centrated solution to give nitrogen and hydrogen chloride) NH,Cl+NC1, = N, + 4HC1.The reactions have been considered which occur when ammoniaand chlorine react in acid solution, in alkaline solution, and indilute solutions of ammonia and liypochlorous acid.It has beenshown previously 4* that, when chlorine gas reacts with 0.5 per cent.ammonia solution, the reaction takes place in accordance with theequation 3NH, + 6C1, = N, + NCI, + 9HC1, equimolecular quantitiesof nitrogen and nitrogen trichloride being produced. This reac-tion, which is of the nintli order, has been criticised, and as a resultof a number of experiments i t is concluded that the reaction is onlythe resultant of a number of intermediate reactions, the first ofwhich is the formation of monochloroamine, according t o the equa-tion NH, + C1, = HCl + NH,Cl.Solutions of nitrous acid may be prepared far more readily bythe interaction between equivalent quantities of barium nitritea i d sulphuric acid than by the action of hydrochloric acid on silvernitrite.49 I n the latter case the reaction rarely passes to comple-tion owing to the coating of the silver nitrite with the insolublesilver chloride.Measurements of the velocity of decomposition ofnitrous acid were made a t O0, 21°, and 40°, and they show t h a tthe reaction is uniniolecular. The velocity-coefficients at these threetemperatures are 0.00014, 0.00022, and 0.00057 respectively. Ac-4 8 W. A. Noyes and A. C. Lyon, J . Anher. Chem h'oc., 1901, 23, 460 ; A . ,4 9 P. C. RBy, M. L. Day, and J. C. Ghosh, T., 1917, Ill, 413; A . ,1901, ii, 601.ii, 301INORGANIC CHEMISTRY. 53cording to conductivity determinations, the dissociation constantof nitrous acid a t Oo is 6.0 x 10-4. The most concentrated solutioiiof the acid t h a t can be obt'ainec' a t 0" by the above method isAn investigation lias been matle of the reduction of vaiiadic wit]by hydrioclic acid.20 Several papers have been publislied in wliiclithis reactioii has been discussed, and very contradictory resultshave beeii obtained.Amongst the most recent work may be men-tioned t h a t of Ditz and Bardach, who stated t h a t the product ofthe reaction is vanadium trioxide.51 This conclusion is a t variancewith the results of previous workers, and in consequence the presentinvestigation was undertaken. It was found t h a t the reactioii isinfluenced very considerably by the oxidation of the hydrogeniodide by means of air, and care was therefore taken to excludeair by means of a current of hydrogen.Tlie iodine set free in thereaction was removed by means of carbon disulphide, the additionand removal of carhoii disulpliide being continued until 110 furtheriodine was extracted after several hours' keeping. Tlie combinedcarbon disulpliide solutions were then titrated with sodium thiosul-pliate solution. It was concluded from the results obtained t h a ttlie reduction only proceeds to quadrivalent vanadium ; further, tliereduced vanadium solution is blue, and not green, as i t oixglit to beif a tervalent vanadiuni coinpound be present.It would seem probable t h a t the oxidatioii of hydrogen iodide byair is catalysed by vanadium pentoxide.Reference may be made to the preparation of certain dottblesalts of bismuth chloride with chlorides of bivalent metals.5" Thebismuth chloride is dissolved in the smallest* possible quantity ofconcentrated liydrocliloric acid, and the solution is treated wit,llth5 carbonate o r hydroxide, or in a few cases the chloride of thebivalent metal.The latter was added in some cases so long as itdissolved, in other cases in amounts less than this. I n 110 casedid the solution of bismuth chloride (1 mol.) dissolve more than1 rmol. of the bivalent chloride. The solutions are then concen-trated over sulphuric acid until the double salts crystallise. Thesedouble salts are colourless (except when a coloured cation has beenadded), hygroscopic, and are decomposed by water, bismuth oxy-chloride being precipitated.Three series of salts have beenobtained. The first series may be regarded as the derivatives ofpentachlorobismuthic acid, H,BiCl,, and of these are described61 H. Ditz and F. Bardach, Zeitsch. anorg. Chew., 1915, 93, 97 ; -4., 1916,68 R. F. Weinland, A. .4lber, and J. Schweiger, Arch. Pharm., 1916, 254,0.1 85 S .G. Edgar, J . Amer. Chem. SOC., 1916, 38, 2369 ; A . , ii, 36.ii, 347.521 ; A . , ii, 37454 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.BiC13,MgC‘1,,8H,0 ; BiC13,CaC1,,7H,0 ; BiCl,,SrC1,,8H20 ;BiC13,BaC1,,4H,0 ;BiC1,,CoC1,,6H2O ; BiCl,,NiCI,, 6H,O. The second series may belooked upon as the derivatives of tetraclilorobismuthic acid, HBiCl,,and is exemplified by 2&C93.CaC1,,7H,0 ; 2BiCl,,SrCl,, 7H,O ;2BiC1,,BaC1,,5H20.The third series contains derivatives of hepta-clilorodibismnthic acid, HBi,CI,, and is exemplified by4BiCl3,MgCI,,16H,O ;4BiC13,S’rC1,, 12H20 ; 4BiC13,MnCl,,1 2H,O ; 4BiCI3,FeCl,,12H,O ;4BiCl3,CoC1,,12H,O ; 4BiCl3,KiC1,,12H,O.Group V I .The behaviour of ( ( potassium ozonate ” on keeping, slid on treat-ment with water o r dilute acids, has been discussed.53 This coni-pound loses its colour on keeping and changes into potassium hydr-oxide, oxygen, and potassium tetroxide. Since potassiumtetroxide, on treatment with water, yields oxygen and hydrogenperoxide, i t may be written as K*O*O*K,O,, and, therefore, thereactions of the ozonate, t o which may be ascribed the composition(KOH),O,, may be expressed as follows : 3[(KOH),O,] =21i,O,,O, + 2KOH + 2H,O, 3[(KOH),O,1 = 2K,O, -t 2H,O + 0,) aridK,O, + (KOH),O, = K,O,,O, + 2KOH.It is supposed t h a t ozonedecomposes into oxygen and atomic oxygen in contact with thealkali, and t h a t i t is only the latter which reacts. This wouldaccount for the fact that no more powerful oxidising agent isobtained .Rubidium and msium hydroxide form orange-red ‘ I ozonates,”and m i u m carbonate also becomes temporarily orange-coloured in acurrent of ozone.When a current of ozonised oxygen 5-1 is passed through aceticacid, acetic anhydride, ethyl acetate, chloroform, or carbon tetra-cliloride a t the ordinary temperature a blue solution is obtained,tlie colour persisting for more than fifteen t o twenty hours with thetwo last-named solvents, but disappearing more rapidly with theothers. Comparative experiments with a current of oxygencontaining approximately 6 per cent.of ozone indicated t h a tcarbon tetrachloride dissolves seven times as much ozone as anequal volume of water, and, when saturated, contains three timesas much ozone as the original ozonised oxygen.The reactions of ozone with iodine, iodides, iodates, and periocl-atea have been investigated.55 Ozone react,s with solutions of53 W. Trauhe, Ber., 1916, 49, 1670 ; A., 1916, ii, 613.5 4 F. Fischer and H. Tropsch, ibid., 1917, 50, 765 ; A . , ii, 463.5 5 E. H. Riesenfeld and F. Benclter, Beitsch. nnorg. Chent., 1916, 98, 167 ;A , , ii, 201INORGANIC CH EMISTRT. 55potassium iodide instantaneously, even below 0°, but the finalequilibriuiii in the solution between K', OH', I', Io', 1 0 ~ ' ~ andTO,' is only attained after some days.The higher the concentra-tion of the ozone in the oxygen used the greater is the influence ofthe hydroxyl ions. I n acid solutions the ordinary reaction iaaccompanied by one in which three atoms of oxygen from a mole-cule of ozone take part. This may consist of an addition of ozoneto iodine ions, forming iodate ions, or of a formation of hydrogenperoxide. Ozone is without action on neutral and acid solutionsof potassiuin iodate, but in alkaline solution oxidation to periodatetakes place. .No evidence wasfcund for the existence of a modification of oxygen containing morethan three atoms, tlie differences observed by Harries between theresults of gravimetric and volumetric estimations being due to theaction of hydroxyl ions.This conclusion, however, is not acceptedby Harrie~.~GThe preparation of certain new salts of bivalent chromium,together with the properties of cliromous salts, may be noted.Ckomic salts may be electrolytically reduced to chromous saltswith a cathode of pure lead.57 This reduction has been studiedquantitatively by measuring the amount of chromous salt produceda t any moment by adding excess of iodine and titrating the unusedportion, and also by following tlie course of the reduction byreadings a t a voltameter and a t the electrolytic cell of the volumeof hydrogen liberated in a given time. To protect tlie solutionsagainst the air they are covered with light petroleum.The mostfavourable conditions are the electrolysis of the violet chromic saltsin moderately .wid concentrated solutions with a current densityof 2.5 amperes per sq. ticm. The 1110re cDmmon green salts inequivalent solutions require a greater expenditure of current thanthe violet salts, but they yield much more concentrated solutions.They are, thel-efore, more suitable in the end for the production,a t any rate, of solutions rich in chromous salts, but not entirelyfree from chromic salts. The same slower reduction of the greellcomplexes is observed when t.he solutions are treated with zinc,By mixing a well-cooled, concentrated solution of chromouschloride with various alkali salts of organic acids, the followingnew salts have been obtained 58 : chromous formate,Cr(HC0,),,2H20,re 3 cuhes ; cliromous ammonium formate, NH4Cr(HC02)3, palebrownisli-red needles ; red chromous glycollate, Cr(C,H,O,), ; Bor-cleaux-red chromous malonate, CrC3H20, ; blue chromous sodiunl6 G C.Harries, Zeitsch. anorg. Chem., 1917, 99, 196 ; A . , ii, 464.5 7 W. Tranhe and (Miss) A. Goodson, Ber., 1916,49, 1679 ; A . , 1916, ii, 625.E S W. Traitbe and W. Passarge, i b i d . , 1962 ; A . , 1916, ii, 626.Ozone has no action on periodate56 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.malonate, Na,Cr(C,H,O,),. The solutions of all these salts have theusual blue colour of chromous salts.Chromcus salts are gradually oxidised, especially in acid solu-tions, with the liberation of hydrogen, thus : 2Cr0 j- H,O =Ck,0,,+H2, and for this reason they are able in the presence ofwater to reduce compounds with double o r triple linkings.Acetylene is reduced t o ethylene, but not t o ethane.For example,on shaking 1200 C.C. of this gas with a solution of chromouschloride, made by adding an excess of zinc to 70 grams of greenchromic chloride dissolved in 120 C.C. of 25 per cent. hydrochloricacid, complete reduction occurred in less than an hour. Nitrousoxide -in the presence of alkali hydroxide is reduced quantitativelyto nitrogen ; similarly, nitric acid and liydroxylamine are reducedquantitatively t o ammonia. The yield of aininonia obtained, liow-ever, by the reduction of nitrous acid is not quantitative.Although chromium phosphate has formed the subject of a nuin-ber of investigations during the past sixty years, many of its pro-perties appear to have been unrecorded.Some new investigations011 this salt may be noted.59 When cold solutions of equal weightsof chrome alum and disodium hydrogen phosphate are mixed, nviolet precipitate of amorphous chromic phosphate is produced.This precipitate, when allowed to remain in the solution for a dayor two, is converted into a violet, crystalline hexahydrate. It isessential that the first amorphous precipitate be not left too longin contact with the ~olution, as after a week it becomes entirelyconvered into a green, amorphous tetrahydrate. This change iscatalysed by sodium sulphate solution o r chrome alum solution,the latter being the more powerful catalyst, and is greatly influ-eixed by temperature.If the violet hexahydrate is heated a t looo for some time, or,better, if boilej with water for half an hour, it is completely con-verted into a green, crystalline hydrate, CrP0,,4H20.On boilingthe violet, crystalline hexaliydrate with acetic anhydride, i t formsa green, crystalline dihydrate similar in appearance t o the tetra-hydrate. Both these green hydrates are stable in the presenceof moist air or water. When heated to low redness they quicklybecome converted into a fine, black, amorphous chromic phosphate,and when strongly heated this changes into a green basic salt..Amorphuus, green chromium phosphate is prepared by precipitat-ing a hot chrome alum solution with excess of disodium hydrogenphosphate, and washing repeatedly with boiling water.I n a, desic-cator a t the ordinary temperature this compound rapidly losesweight until the composition is CrP0,,4H20. When heated a t 60°5 9 -4. I?. Joseph arid W. N. Rae, T., 1917, 111, 106; A., ii, 210INORGANIC CHEMISTRY. 57i t loses two molecules of water, and a t dull red heat i t is convertedinto brown, amorphous chromic phosphate.By the interaction 60 of chromyl chloride and phosphorus tri-chloride or phosphorus tribromide in dry carbon tetrachloride solu-tion, precipitates are obtained which, when collected, washed witlicarbon tetrachloride, and dried in a current of dry, C0,-free air,liave the composition CrOCl ,POCl, and CrOBr,POBr, respectively.The react'ion being extremely violent, i t is carried out in 0**2 mol.soltitions, and takes place according t o the equation 2CrO,CI, +PCl,= 2(CrOC1,POCl3) + PCl,.These double compounds are ex-tremely deliquescent and react, with water with development ofheat, according t o the equation CrOCl,POCl, + 2H,O = CrCl,+-HCl+ H,PO,. On ignition, the compounds CrOCl (or Cr203,CrC1,)aiid CrOBr (or Cr,O,,CrBr,) are obtained.Molybdenum pentasulphide, Mo2S5, has been prepared by reduc-ing a solution of ammoniuni molybdate, containing more than%3 per cent. of sulphuric acid, with zinc, until the colour is darkred, and then diluting, filtering, and saturating the solution withhydrogen sulpliide.61 The precipitate is collected and washed withliot water and then with alcohol.It is shaken repeatedly withcarbon disulphide, washed with ether, and dried a t 68-75O, whenit has the composition Mo2S,,3H,O. One molecule of water is losta t 1 35-140°, but further heating causes decomposition. Carefullieating in carbon dioxide gives the anhydrous sulphide, Mo2S3,which is almost black. When the hydrated compound is heated inliydrogen sulphide the compound, 2Mo,Sj,3H,S, is formed.Group "11.The iriecliaiiisiii of the conversion of alkaline solutioiis of sodiimiliypochlorite into sodium chlorate has been studied.62 At a terri-perature of 50° the reaction is of the second order rather than of thethird, and, therefore, the first stage is represented by the equation2NaClO = NaClO, + NaCl.There is also an evolution of oxygen,which evidently occurs according to the equation 2NaC10 = 0, -+3h'aCI. Further, the transformation of the chlorite into chlorateis a biinolecular reaction, and follows the equation NaClO -t-NaClO, = NaC10, + NaCl. The formation, therefore, of chloratefrom hypochlorite occurs according t o the equations (1) 2NaClO =-KaC10, + NaCI, and (2) NaClO 1- NaClO, =: NaCIO, + NaCl. TheH. S. Fry and J. 1,. Domelly, J . .4??ie?'. Chem. Soc., 1916, 38, 1923 ;61 F. Jlawrov and M. Nikolov, Zeitsch. anorg. C'hem., 1916, 95, 188 ; A . ,6 2 F. Foerster and P. Dolch, Zeitsch. E'lektrochcm, 1917, 23, 137 ; .4., ii, 367.A . , 1916, ii, 626.ii, 47958 ANNUAL REPORTS ON THE PROGRESS OF CIIEMISTRY.latter reaction proceeds inucli inore rapidly than tlie former.Thefoliowing velocity constants have been obtained : K1, 50° = 0.0019,25°=0*00010 ; K,, 50°= 0.050, 2 5 O = 0.0035. The temperature-coefficient of K , is 3.15, whilst that of K , is 2.88.(7-'l'ozq1 I7IZl.There is considerable uncertainty regarding the existence offerric trisulphide, Fe.,S,,, and some light has heen thrown on thematter by further work. When moist ferric hydroxide, or ferrichydroxide suspended in water, is treated with hydrogen sulphide,i t becomes black, owing to the formation of ferric trisulphide, inaccordance with the equation 2Fe(OH), + 3H, = Fe,S, + 3H20.G3I n a inoist condition in the abseiice of air, or in the presence ofexcess of hydrogen sulphide, i t is transfobed into a mixture ofthe disulphide and sulphide, thus : Fe,S, = FeS, + FeS.This changetakes about a week a t tlie ordinary temperature, but oitly a fewhours a t GOO. The mixture produced, being only partly solublein dilute hydrochloric acid, may easily be distinguished froin theoriginal trisulphide, which is readily aiid completely soluble.When dried in a vacuum over phosphoric oxide, ferric trisulphideis very stable.When exposed to the actioii of the air in presence of alkali,ferric trisulphide gradually becomes pale yellow, sulphur beingdeposited. The product resembles liinonite in appearaiice, andwhen dried gives a fine, yellow powder contaiiiiiig a constant per-centage of water, which is less than that corresponding withFe(OH),.When precipitated ferrous sulphide is boiled with flowers ofsulphur, iron disulphide is formed.Ferric disulphide is also pre-cipitated when a solution of sodiuiii trisulphide is ndded slowly t oa boiling solutioii of ferrous sulphate, sulphur being liberated titthe same tinie.Since ferric clisulphide is the filial product of the actioii ofhydrogen sulphide on ferric hydroxide iii the abseiice of alkali, theproduction of iron pyrites iu nature caii be explained.A very conveiiieiit method has been described for the prepara-t joii 01 chloroplatiiiic acid, which obviates all difficulties arisingfroin the f orina t ioii of nit rosopla t inic chloride and chloroplatiiiousacid, the removal of which is so troublesonie when aqua regia isused .fi4 The iiiethod consists i n the use of hydrogen perosicle, which63 IF.Rodt, Zeitsch. angew. ('hem., 1916, 29. j , 41'2 ; .I., ii, 142.R4 P. Rudnick atid H. E. Cooke, J . A m e v . C'hei,z. Yoc.. 1 9 t 7 . 39, ( i 3 3 ; .4.,ii, 264INORGANIC CHEMISTRY. 59readily effects the dissolution of platinum black in hydrochloricacid, yielding a solution which is a t once free from uitrosoplatinicchloride and entirely oxidised to chloroplatinic acid. The methodmay be described in detail, and consists in covering 10 grams ofplatinum black, dried, b u t not ignited, with 50 C.C. of hydrochloricacid. The mixture is heated to 50-60°, and hydrogen peroxide(3-30 per cent.) is slowiy added a t such a rate as to maintain ainoderate evolutioii of chlorine. When the platinum has entirelybeen dissolved, the solution is coiiceiitrated. Wheii a 3 per cent.solution of hydrogen peroxide is used, it may be necessary t oevaporate the solution to a smaller bulk iii order to effect the coni-plete dissolution of the platinum.Reference may be made t o some work on the oxides of rutheiliuni,rhodium, aiid osmium. Finely powdered ruthenium oxidisesrapidly when heated in oxygeii, the maxiinnin of absorption ofoxygen corresponding very closely with the oxide, R u O , . ~ ~ Thevalue is, however, slightly lower, owing to voIatilisatioii. It isindependent of the temperature between 700' aiid 1000°, althoughthe rate of foriiiatioii of ruthenium dioxide varies considerably.The formation of the volatile tetroxide begins a t GOOo aiid increasesrapidly with the temperature, beiiig 4000 times as great a t 1200Oas at 700O. The sublimate of tetroxide, however, coiltailis crystalsof the dioxide.On the other hand, when rhodium is heated in air or oxygeiiat, temperatures froiii 600° to 1000°, the greyish-black oxide,Rh,O,, is always formed, the rate of formation increasing rapidlywith the temperature.G6 A t 1150°, the oxide is completely clecoiii-posed, the iiietal being obtained.Colloidal solutioiis of osmium dioxide are obtained by the reduc-tion of the alkali osiiiates with alcohol or by the hydrolysis of theohi~ichlorides.G7li,OsO, 4- 2H20 + C',H,*OH = Os0,,2H20 + 2KOH -1- C,l140 ;By the additioii of electrolytes to the neutral solutions, the dioxidecall be precipitated, but it forms a colloidal solution again wheiitreated with acids, alkali hydroxides, or ainiiioiiia, or washed freefrom eIectrolytes. Concentrated solutions of the colloidal oxideitppear black by reflected light or blue by traiisiiiittecl light.The oxide prepared by reduction or by the hydrolysis ofThe reactions are as follows :KZOsCI,; -r 4H2O = OSO,,~H,O 7 2KC1+ 4HC1.'j A. Gutbier, G. A. Leiiclis. H. \Viessiiianri, mid 0. Alaisch. %cifs(*h. onoig.6 6 A. Gutbier, A. Huttlinger, ~ i i d 0. JIaiscli, [bid., 95, 225 ; -4., ii, 46;;.6 7 0. Ruff and H. Rathsburg, Ber., 1917, 50, 484; A4., ii, 323.C'hewi., 1916, 96, 182 ; A , , ii, 3860 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.arrlmoiiiuni osrqichloride retains alkalis and organic substancesvery firmly. As the result, the dry powder may kindle on ex-posure to the air or detonate on warming. An old preparation orone t h a t has been warmed with water for some time is not sodangerous, but i t then contains much metallic osmium.Amorphous osmium dioxide, containing about 1 per cent.. ofsodium chloride, is obtained on heating potassium osmichloridewith pure sodium hydroxide solution in the absence of air. Thedried powder has the composition Os0,,2H20. It loses one mole-cule of water a t looo and the other a t ZOOo, the residue being abluish-black powder. This oxide reacts with hydrogen with almostexplosive violence, and with oxygen readily to give osmiumtetroxide. When heated in an indifferent atmosphere, it becomesdark brown, and decomposes a t about 500° into osmiuin andosmium tetroxide. The reaction is reversible, as the pure dioxidecan be obtained by heating very finely divided osmium withosmium tetroxide a t G50° in an atmosphere of nitrogen. Whenthe dioxide is heated in an atmosphere of osmium tetroxide (partialpressure about 100 mm.) a t 640°, it changes into a crystallineform. A copper-coloured sublimate is usually deposited, and it ispossible t h a t the volatile oxide to which this sublimed dioxide isdue is a trioxide, thus : OsO, + OsO, = 2 0 ~ 0 , .E. C. C. BALY

ISSN:0365-6217    

DOI:10.1039/AR9171400027

出版商:RSC    

年代:1917

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART I.-ALIPHATIC DIVISION.DURING the greater part of the period embraced by the currentreview, the writer had the feeling that if the Annual Report waxto preserve its reputation for being a fair index of contemporaryresearch, the section on aliphatic compounds would on this occasioiibe brief, disconnected, and even uninteresting. The publicatio1t.lwhich appeared during the second half of the year did much tomodify this first impression, but it has been a case of making thebest of things, and the Report is thus presented with a full know-ledge of many shortcomings. The task of following and studyingthe course of organic research during the past twelve months hascertainly afforded many compensations t o the writer, and toinstitute comparisons between recent work and the product ofmore peaceful days would be unfair to those who have kept formalresearch alive despite the distractions of the times.I n any case,wch criticism as might be called for does not apply t o our owiiJournal, the pages of which are unsullied by those records of mean-ingless compound-making so prominent in other periodicals to whichgood taste prevents more pointed reference. 'There has been nosacrifice of standard in order to preserve bulk, and there has beenin many cases a gratifying combination of experiment and specula-tion, so that, taking everything into account, there in reason t o benioderately satisfied with a year's steady if unexhilarating progress.Hydro curb ons .I n collecting the material for this section of the Report, thewriter anticipated a difficulty which has not been forthcoming.I11few classes of compounds more than in the aliphatic hydrocarbonsdid it, seem probable that care would be necessary t o restrict selec-tion to topics of general theoretical importance, and leave moretechnical subjects to the Reports on Applied Chemistry.No such critical selection has, however, been necessary, as thenumber of publications on aliphatic hydrocarbons has been small6 2 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and in only a limited nuniber of cases do they admit of synopsisor brief discussion. For the time being, systematic ysearch 011simple representatives seems to be at a standstill.Ae has recently been the case, a number of papers have appeareddealing with the conversion of paraffins into aromatic hydrocarbons,and the impression has gradually been gained t h a t the actualresults obtained must give greater promise of ultimate technicaladoption than the published descriptions would lead one to expect.As a general rule, the conversion from the paraffinic to the aromatictype is effected by “cracking,” and a prominent feature of recentwork in this field is the steady rise in the pressures and a corre-sponding diminution in the temperatures employed .I > 2 Inciclent-ally, i t may h e remarked that somewhat similar considerationsapply to the degradation of aromatic hydrocarbon; 2 in the absenceof catalysts.Unsaturated compounds still continue to demand most atten-tion in this section, and the synthetical applications of acetylene,to which reference has repeatedly been made in recent Reports,may well revolutionise many methods of preparation in the nearfuture.Under this heading, few new results have been forth-coming in the past year, and published references t o acetylenehave been disappointing. I n a somewhat different field, attemptshave been continued to trace the part, played by acetylene in theformation of heterocyclic 4 compounds, arid although iiumerousaromatic products have been obtained by subjecting the hydro-carbon to the action of hydrogen sulphide, ammonia, or steam a thigh temperatures, the work leaves the impression of being in somedegree empirical.Greater interest’ will be taken in the suggestion 5 that copperacetylide plays a definite part, when used as a catalyst, for theconversion of benzenediazonium chloride into chlorobenzene, incontributing its carbon atoms to the final product.The ideaoriginally put forward by Sandmeyer, t h a t the catalysis is in thefirst place due t o the formation of copper chloride, does not takeinto account the destiny of the acetylene thus liberated, but, asa result of the study of secondary reactions, it is now maintainedt h a t such is the case.G. Egloff and T. J. Twomey, M e t . C’hem. Etig., 1916, 15, 246 ; A.. 19lG,W. F. Rittman, Brit. Pat., 9163 of 1915 ; A . , i, 14.Synthetic Hydro-Carbon Co., Fr. Pat., 479786 ; A . , i, 16.R. Meyer and H. Wesche, Ber., 1917, 50, 422 ; A., i, 313.IT.V. Scharvin and N. T. Plachnta, J . Russ. Phyls. CAevi. SOC., 1916,i , 786.4$, 253; A . , i, 179ORGANIC CHEMISTRY. 63Researches on the polymerisation of olefinic hydrocarbons havebeen coiitiiiued oii iiornial lilies and have given results which arecoiisisteiit, with earlier observations,c but there is a marked falling-off in papers dealing with caontchoiw. In last, year’s Reportl, con-sitlerable space was devoted to the discussion of several papers onthis subject by Ostromisslenski, and further contributions fromthe same worker are now available. His views as to structureand isomerism of caoutchoucs have been slightly simplified, buthe continues to apply the expressions I ‘ normal ” and I ‘ abnormal ”to these compounds according to the physical properties of thecomplexes, and without reference to the chemical behaviour of theozonides prepared from them.Descriptions are now given 7 of‘the caoutchoucs obtained by polymerising various hydrocarbons, ormixtures of hydrocarbons, which agree fairly well with the observa-tions of earlier workers, and several conflicting results, which havebeen the cause of much discussion in the past, are now explained.He points out t h a t although the polymerised product from pureisoprene is naturally different from t h a t obtained from theisoprene-amylene mixture, i t is impossible to detect even con-siderable proportions of the ainylene constituent by analysis, andmaintains that variation in physical property alone gives anyindex of composition.Another point of interest is the conversionof the isoprene-amylene caoutchouc obtained by the sodiummethod into an isomeric P-form by the action of either bariumperoxide or beiizoyl peroxide. It would appear, so far as anygeneralisations caii be established in these reactions, that the useof peroxides as polymerising reagents generally gives a differentproduct from t h a t formed by the action of sodium. An exceptioiiis, however, furnished by the case of erythrene caoutchouc, ofwhich one variety is produced, irrespective of the reagent employedin its formation.I n a further paper,8 the same author furnishes some resultswhich are more attractive to the organic chemist. Accepting t h a tthe polymerisation of vinyl bromide gives rise to the symmetricalbromide of erythrene caoutchouc, he has attem?ted t o correlatethe corresponding chloride of the complex with polynierised vinylchloride.The latter compound in the Iiquid condition is rapidlytransformed under the influence of light from a mercury lampinto a-caouprene chloride. This particular variety is soluble, anclthus the molecular weight could be determined, giving a resultS. IT. Lebedev and A. A. Ivanov, ? J . Rtrss. Phyq. C‘hcn,. SOC., 291G, 48,997 ; A . , i, 126.I. I. Ostromisslenqki, ibid., 1Oi1 ; --I., i, 399.l. I. Ostromisslenski, ibid , 1916, 46, 11:<3 ; A . , i, 10464 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in close agreement with the formula C3,H,18Cll,;. Apparently thecompound is saturated, and i t is thus regarded as a single ringstructure containing the fragment -CHCl*CH,- repeated sixteentimes.So far, the results described are convincing, but theevidence on which the statement is made t h a t the chloro-com-pound is identical with the symmetrical chloride of erythrenecaoutchouc could only be valuated by those who have personalexperience in this type of work. What is claimed to be the un-symmetrical chloride of erythrene caoutchouc has also been pre/pared directly from the hydrocarbon complex by treatment, incarbon tetrachloride solution, with t h e appropriate amount ofchlorine similarly dissolved. On the evidence produced, however,i t is difficult to draw any real distinction between this productand caouprene chloride.It is evident that Ostromisslenski brings to the caoutchoucprobleni both fresh ideas and new working methods, but, for thetime being, he has this field of research t o himself.Very little work has recently appeared dealing with unsubsti-tuted alcohols, and attention may be restricted to one or twoinvestigations which deal with structural problems in t h e poly-hydroxy-series.Since the appearance of Boeseken’s papers on theconductivity changes which ensue when boric acid is added tosolutions of polyhydroxy-compounds, much interest has beendisplayed in the application of his principles to questions of con-stitution. According to Boeseken, the reaction between the acidand the alcohol is limited to cases where hydroxyl groups arefavourably situated, and a positive result is indicated by a markedexaltation in conductivity and also, in the case of optically activecompounds, of the rotatory power.These views have in recentyears been supported in a number of ways, and a further stephas now been made by the preparation of definite compounds ofinannitol and dulcitol wit.h metallic metaborates.9It is true t h a t the isolation of such compounds has only a nindirect bearing on Boeseken’s views, but, in some particulars, theresults are suggestive. Thus, in the case of mannitol, the rotatorypower is b u t little affected when the amount of acid present isincreased beyond equimolecular proportions, b u t this does not holdfor the case of met$allic borates, where apparently the reaction isindependent of the configuration of the alcohol.I n investigations9 &I, Griin mid H. Xossowitsch, Mowatsh., 1916, 37, 409 ; A . , 1916, i , $87ORGANIC CHEMISTRY. 65of this nature, some danger is involved in the possibility that theinethod of allocating hydroxyl groups t o structural positions 011the evidence of conductivity may be applied in cases whereexternal factors may vitiate the result. This applies with specialforce to hydroxy-acids, which are proPoundly affected by varia-tions in the concentration of their solutions, and some idea of thecomplications thus introduced is gained from inspection of recentresults obtained with pyruvic and lactic acids.10 I n any case,in work of this description, due regard must be paid to the degreeof hydration attained by boron trioxide in solution, and to thepossibility of organic molecular complexes being formed by com-bination with different boric acids.Until recently, comparatively little use has been made of theGrignard reaction in research on polyhydroxy-compounds, butobviously this is largely explained through lack of appropriatesolubilities.This difficult-y may, however, be overcome by the useof soluble derivatives, from which the substdtuting groups canafterwards be removed, and further examples involving thismodification are now forthcoming.11 Starting from a fullyacetylated gluconolactone, reaction with magnesium acyl haloidsgives the corresponding sorbitol derivatives, of which aa-dibenzoyl-sorbitol may be quoted as an example. By a similar process,aa-dibenzoyldulcitol has been obtained from tetra-acetylgalactono-lactone, and an unusual feature of the compound in question isthe ease with which it is converted into the internal anhydride.o----I 1 H O H 1 HAny evidence as to the formation of definite anhydrides in thisseries is valuable, in view of the obscurity in which simiIar changesin the sugar group are enveloped, and i t should be possible t oestablish relationships between ring-formation and configurationby further work similar to that now described.AZdehydes and Ketones.The steady and persistent' demand for the simpler aliphaticaldehydes which has been apparent for some, years has focussedlo J.Boeseken, L. W. Hansen, and S. H. Bcrtram, Rec.trav. citint., 1916,35, 309 ; A., 1916, ii, 200.l1 C. Paal (with C. Kiister and C. Roth), Bw., 1916, 49, 1583 : d., 1016,i, 787.REP. - VOL, XIV. 66 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.att,ention on the inadequacy of the usual oxidation methods ofpreparing these compounds. No doubt, so far as acetaldehyde isconcerned, processes commencing from acetylene will go far t osolve this difficulty, and new variations of this reaction have beendescribed .I2 Not only the preparation, but the identification, ofsimple aldehydes and their isolation in a pure condition are mattersof concern to those who work in this field, and thus a welcomewill be accorded to a review in which the behaviour of typicalmembers towards various reagents is surnmarised .I3 The resultsdescribed show that lower members oi' the series of aliphaticaldehydes are best characterised as nitrophenylhydrazones, whilstfor higher members, seniicarbazone formation is more satisfactory.As has recently been the experience of workers in the sugar group,the use of diphenylmethanedimethyldihydrazine, as a reagent forthe identification of aldehydes generally, has met with strikingsuccess.Before leaving this subject, it may be mentioned thatthe isomeric o-bromophenylhydrazones of glyoxylic acid have nowbeen examined in greater detail, and the conditions governingtheir formation established. The reactions of the two compoundsare more diagnostic than is often the case with such stereo-isomerides, and thus spatial formulze have been ascribed to themwith some degree of certainty.14Although the function of formaldehyde as a methylating agentin certain cases has long been recognised and utilised in workingprocesses, no very satisfactory explanation has been offered as tothe mechanism of its action.The problem is, however, greatlysimplified as the result of a study15 of the changes in whichmethylamines are formed by this agency. I n particular, theidentification of methyl f ormate and .carbon dioxide as significantproducts when ammonium chloride reacts with impure form-aldehyde under mild conditions, and the successive drop in yieldof these products when mono- or di-methylammonium chloridesare employed, show that, during the process, oxidation changesare operative in varying degree.The suggestion is made that thefirst stage of the reactions which lead to the formation of mono-and di-methylamines is the production of methyleneimine.I. H*COH + NH,(HCl) + H*CH<OH -+ CH,:NH(HC!I).NH212 Union Carbide Co., U.S. Puts., 1213486 and 1213487 ; A., i, 318.l3 C. D. Harries, Chcm. Zentr., 1916, ii; 991 ; A., i, 210.11 M. Busch, F. Achterfeld, and R. Seufert, J. pr. Chem., 1915, [ii], 92,l5 E. A. Werner, T., 1917,111, 844 ; A., i, G32.1 ; A., i, 228ORGANIC CHEMISTRY. 67I n the presence of formaldehyde, simultaneous oxidation andreduction then ensues, the reaction iilvolving a molecule of water.11. CH,:NH(HC'I) + H,O + H*COH + CH,*NH,,HCl+ H*CO,H.'The extension of similar principles to the interaction of form-aldehyde and alkylammonium chlorides accounts for the productionof dimethylamine, and indicates that the tertiary amine is not adirect product of the reaction.The paper to which reference isnow made contains niore than the theoretical discussion, as goodworking directions are given for the preparation on the large scaleoE methylamine arid dimethylamine salts.Now that clearer views prevail as to the nature of aldehyde-ammonia, more interest is attached to synthetical reactions involv-ing the use of the compound, although, as a rule, its behaviour issomewhat fickle. An additional example of this is furnished1G bythe fact that, when condensed with y-benzoquinone, the amino-groups of the aldehyde-ammonia play a part in the reaction, as theessential product has the structure indicated by (I).On the ot,herhand, the behaviour towards anthraquinone is entirely different,as a nitrogen-free derivative (11) is produced.0IIThis variation is not entirely due to the structural differencebetween the quinones which take part in the reaction, and is prob-ably attributable to the temperature conditions, as, in the onecase, the aldehyde-ammonia doubtless reacted as such, and, in theother, as a mixture of free aldehyde and ammonia.The difficulties attendant on the study ot glyoxal are one byone disappearing as the result of much patient research, and thereis now ample choice in the reagents by means of which the poly-merised aldehyde may be converted into the monomeric form.l7Of these, the most successful is acetic anhydride, but it is t o benoted that prolonged action with this reagent results in the forma-tion of the symmetrical tetra-acetate, C,H,(OAc),, which pre-sumably has an acetal structure.The compound in question iswell defined and displays so many reactions characteristic of mono-l6 P. C. Ghosh, T., 1917, 111, 608; .2., 1, 517.K. Hess and C. Uibrig, B e y . , 1917,50, 366 ; A . , i, 310.0 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.meric glyoxal that, in the future, it may play an important partin the development of this difficult subject.A further step has also been made in a problem which has adirect' bearing on the vexed question of the curious degradationswhich ensue when a hexose is acted on by ammonia.Some yearsago, it was shown that ammoniacal zinc oxide reacts with glucoseto give methylglyoxaline, and the probable course of the reactionis now indicated by the results of a further research.'* It hasbeen found that methylglyoxaline is f orined immediately on add-ing ammoniacal zinc oxide to methylglyoxal and formaldehyde inaqueous solution. This a t once gives a clue to the formation ofmethylglyoxaline from the sugars, and it is significant that, in asimilar test, dihydroxyacetone reacted only slowly.As experimental difficulties are frequently encountered in pre-paring cyanohydrins, a brief reference may be made to modifica-tions of the usual procedure.19 Of the variations suggested, themost useful is to dissolve the aldehyde in a solvent immiscible withwater and shake with an aqueous solution of potassium cyanideand ammonium chloride.This particular process answers well, andits application is not restricted, as indicated in the paper, to caseswhere the cyanohydrin is insoluble in the extraneous solvent used.Turning to ketones, attention should be directed to evidence20showing that dry* acetone combines with dry calcium chloride intwo proportions, as it is satisfactory to have a definite explanationof the tenacity with which the pure ketone is retained by thisdrying agent.Presumably as a side issue of other work, several papers haveappeared on the condensation of pyrrole with simple ketones.21The results described are, however, by no means simple, as ingeneral the products, although definite and crystalline, containfour pyrrole residues united to four ketonic residues, and are thusof the same order of complexity as chlorophyll and hzemin.Thereis a special interest attached to sparingly soluble, stable deriv-atives of ketones, as their formation may possibly be elaboratedinto methods of estimating acetone in the presence of related sub-stances. This possibility is supported by the fact that acetoneand methyl ethyl ketone react very unequally with yyrrole,22l8 B. J. Sjollema and Mlle. A. J. H. Kam, Rec. t m v . chim., 1916, 36, 180 ;l9 A. Albert, Ber., 1916, 49, 1382; A., 1916, i, 823.2o L. S. Bagster, T., 1917, 111, 494 ; A . , i, 493.21 V. V. Tschelincev and B. V. Tronov, J.Russ. Phys. Chem. SOC., 1916,22 V. V. Tschelincev, B. V. Tronov, and S. G. Karmanov, ibid., 1210 ; A . ,A . , 1916, i , 791.48, 105 ; A . , i, 91 ; 1916,48, 127 ; A., i, 93 ; 1916,48, 1197 ; A . , i, 411.i, 412ORGANIC CHEMISTRY. 69but, on the other hand, enter into simultaneous condensation withthe reagent to give a ‘‘ mixed” compound of similar type. Afurther idea of the complexity of these reactions is given by theresults obtained in the condensation of pyrrole with form-aldehyde,23 as i t has been shown that the reaction can be modifiedso as t o give various types of products. Thus, under mild con-ditions of alkaline condensation, 2 : 5-dimethylolpyrrole,>NH, 7 :C(CH,*OH)CH:C(CH,*OH)is formed, but in the presence of acids, the polymeride ofis produced in excess.Even in the absence of acids, the cha,ngesinvolved are obscure and give rise to substances very easily affectedby polymerising reagents.Acids and their Derivatives.As a preliminary to more complex subjects, reference may bemade to attempts to prepare simple derivatives of the commonacids which may aid their identification. 21-Nitrobenzyl bromidehas been suggested as a useful reagent for this purpose, as it reactssmoothly with the alkali salts of acids, and the resulting estersare, as a rule, readily crystallised. So far as aromatic acids areconcerned, the products appear to be easily ~haracterised,~~ but, inthe case of many aliphatic acids, the melting points of the estersare inconveniently low and not sufficiently far apart to bediagnostic.This may, in some measure, be compensated for bythe fact that the yields are g00d,~5 but the process breaks down ina number of examples where characteristic tests are hard to find.On the other hand, the normal p-nitrobenzyl esters of malonicacid homolog-ues are easily distinguishable, but, unfortunately, 110result was obtained with lzevulic or mucic acids.26Numerous references in the patent literature show that thepreparation of acetic acid from acetylene has been improved, POas to run as a continuous process, by the use of prefornied aceticacid as a solvent. The technical preparation of acetic anhydride23 V. V. Tsclielincev and B. V. Maksorov, J . Russ. Php. Chem. SOC., 1916,23 E. Lyons and E. E.Reid, J. Amer. Chem. SOC., 1917, 39, 1727 ; A.,25 E. E. Reid, ibid., 124 ; A . , i, 333.2 6 J. A. Lyman and E. E. Reid, ibid., 701 ; A., i, 334.48, 748; A . , i, 164.i, 55970 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.has also been modified,27 and simple methods are now describedwhereby the compand can be obtained free from chlorinated by-products, which are of frequent occurrence when sulphur chloridesare used as the anhydrideforming reageiits.28 I n this and othersimilar cases, acetic anhydride functions as a suitable diluent,which serves t o moderate the reaction and limitl the formation ofextraneous products.29Before leaving the subject of anhydrides, inentioii should bemade of new results obtained by the use of thionyl chloride.Asis well known, the metallic salts of organic acids are acted 011 bythionyl chloride t o give the corresponding anhydrides, but, undercertain conditions, further reaction takes place and the acidchloride results. The mechanism of these changes has alreadybeen carefully investigated,30 and the earlier views are now s u pported by fresh evidence.31 Apparently thionyl chloride acts onsalts in consecutive reactions as shown below:I. 2R*CO,M + SOC1, -+ (RCO,),SO + 2NaC1.The intermediate product, which can be regarded as a derivativeof sulphurous acid, may decompose according to the scheme:--11. (RCO,),SO --+ SO, + (RCO,),O,or, in the presence of excess of thionyl chloride, in terms of theequationThe above explanation is founded on the behaviour of silver saltstowards thionyl chloride, but it is only on rare occasions t h a t theintermediate sulphurous ester is sufficiently stable to admit ofisolation.Another example is, however, provided when potassium xanthateis used in the reaction, which is then arrested definitely a t thefirst stage,2EtO-CS-SK -+ (EtO*CS.S),SO.It may be remarked t h a t when sulphur chloride is employed inthe production of anhydrides, similar intermediate compounds areformed which are exceedingly well defined and comparativelystable.Much patient research has been expended on the subject of theoxidation by hydrogen peroxide of the homologrles of isobutyric111. (RCO,),SO + SOC1, + ZR-COClt 2S0,.2 7 H.Dreyfns, Brit. Pat., 17020 of 1915; A . , i, 194.2 8 H.Dreyfus, Brit. Put., 100450 of 1916 ; A., i, 441.2 9 H. Dreyfus, Pr. Pat., 478951 ; A . , i, 2.3O W. S. Denham and Miss H. Woodhouse, T., 1913, 103, 1861.31 M. &I. Richter, Rer., 1916, 49. 1026; A . , 1916, i, 70ORGANIC CHEMISTRY. 71acid.32 The results obtained are simple, inasmuch as the oxidationproducts are few in number, but their forniatio3 is by no meanseasily explained. Thus, as a rule, two ketones and one aldehydeare produced, as represented below :{CH hTe,*[CH23,,-CH2*CH0CHMe,*[CU21,.[CH,],*C02H~ CHMe2*[CH2 ,*COMeXe*CO*MeOne generalisation which has emerged from this work is thatlengthening of the chain between the carboxyl group andtertiary carbon atom diminishes the yield of acetone, which isthethethepredominating product from lower members of the series.I n arelated subject of research,33 it' is interesting to note that hydrogenperoxide is capable, under certain conditions, of oxidising sodiumbutyrate, with the production of a notable yield of succinic acid.The main attack of the oxidising agent is in this case directedt o the terminal methyl group, a result somewhat unexpected in viewof earlier observations, which showed that oxidation involves thesection of the carbon chain nearest to the existing carboxyl group.One of the few papers dealing with structure which have beennoted is a publication34 on the disputed question of the constitu-tion of meconic acid. The usual view, that the compound is apyrone derivative, will probably require modification, as, oncatalytic reduction under mild conditions, it is converted intotetrahydroxypimelic acid.This result could, of course, be ex-plained on the assumption that, during reduction, the pyrone ringbecame ruptured, but the behaviour of authentic 4-pyrones, whensimilarly treated, lends no support to this view. On the whole,even admitting the irregular properties of meconic acid, the sugges-tion that the compound is a pentahydroxyketopimelic acid,CO,H*C( OH),*CH( OH)*CO* CH,*C( OH),*CO,H,will be accepted with reserve.In the course of experiments on the addition of bromine inaqueous solution to unsaturated acids, some interesting resultshave come to light. The fact, too often ignored, that both bromineand chlorine water contain halogen hydride and the correspond-ing oxy-acid in equilibrium, naturally complicates such reactions,but it has been shown,35 in the case of fumaric acid, that theessential result is the formation of bromohydroxysuccinic acid,CO,H*CH:CH*CO,H + CO2H*CHBr*CH(OH)*CO,H,32 P.A. Levene and C. H. Allen, J . Biol. Chem., 1916, 27, 433 ; A . , i, 3.33 E. Cahen and W. H. Hurtley, Biochem. J . , 1917, 11, 164; A . , i, 535.34 W. Borsche, Ber., 1916, 49, 2538; A., i, 117.36 E. Biilmann, Rec. Irav. chim., 1917, 36, 313; A . , i, 37872 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.thus eniphasising the important part played by hypobromous acidin these additions. Crotonic acid behaves similarly to fumaricacid, and the observation that the normal addition of bromine isfavoured by the presence of potassium bromide is consistentl withthe fact that the equilibrium between halogen hydrides and theiroxy-derivatives is displaced by the presence of halogen salts.Other evidence of a different nature pointing to the comparativelylarge proportion of hypobromous acid present in bromine waterhas been furnished as a result of estimating the relative amountsof ethylene bromohydrin and ethylene dibromide formed onabsorbing ethylene in aqueous bromine.36Halogen acids of the aliphatic series continue to occupy theattention of many investigators, and, as a rule, the object of theseinquiries is t o gain evidence as to the mechanism of changes inwhich the substituting halogen atoms are replaced.Consideringthe frequent anomalies encountered in such reactions, i t is notsurprising that, as the result of physical studies, many perplexingfeatures are disclosed for which no ready explanation can befound.The observation37 that, during the action of sodiuminethoxide on sodium monobromosuccinate, the proportion ofbromine ionised exceeds the corresponding decrease in the alkalititre, may no doubt be accounted for on the supposition that inter-mediate compounds are formed, and this seems t o be anotherfeature of &substituted acids which is not shared by a-isomerides.Naturally enough, considering the interest attached to work ofthis nature, there is a tendency for researches to overlap to someextent. Thus, the decomposition of bromoacetic acid in alcoholicsolution has been studied with results which, with one exception,may be classified as normal.38 When, however, the change ismodified by exposure t o powerful light, under conditions whichexclude access of alkali, the solvent alcohol and the bromo-acidreact so as to give the simple oxidation and reduction products.CH,Br*CO,R + C2H,*OH + CH,*CO,H + CH,*COH + HBr.Another research forming part of a general study of the reactivityof halogen atoms in organic combination39 deals with the actionof alkalis on alkali bromopropionates or bromoacetates, and is lessrestricted in scope than the paper discussed above in that theeffect of solvents in influencing the displacement of the halogenis established.During the period now under review, comparatively few papers31 J.Read and Miss M. M. Williams, T., 1917, Ill, 240; A., i, 313.37 E. H. Wadsen, Zeitsch. physikal. Chem,., 1917, 92, 98 ; A., ii, 250.38 H. W. Cassel, ibid., 113 ; A., ii, 249.33 G. Senter and H. Wood, T., 1916, 109, 681 ; A . , 1916, ii, 523ORGANIC CHEMISTRY. 73have been concerned with simple haloids, and, as it is thusimpossible to deal with them in a separate section, they mayperhaps be discussed a t this stage. An old problem, the isomerisa-tion of isobutyl bromide, has again been exhaustively studied.When carefully purified, the compound proves to be unexpectedlylabile, being transformed wit'h comparative ease into the tertiaryisomeride. The change is not only accelerated by various agents,but is retarded by a number of negative catalysts, including iso-butyl alcohol, so that the real instability of the haloid .is notrevealed until a high degree of purity is attained.4O Curiouslyenough, although isobutyl bromide rearranges t o the tertiaryisomeride in the gaseous state, the change is but little affected bythe catalysts which are most reactive in the case of the liquidcompound.These observations afford a ready explanation of theresults described in a closely related investigation on the dissocia-tion and rearrangement of the isomeric butyl bromides.41Recent studies of organo-metallic compounds are, of course, onlydistantly connected with the subjects now under discussion, and,in any case, the objective of such work lies within the province ofanother section of this Report, but i t may not be out of place t odirect attention to evidence which is strongly in favour of the ideathat the four valencies of lead are interequivalent and are prob-ably symmetrically arranged in space.42Esters.Of the organic reactions which are periodically rediscovered,few can compete with that in which an interchange of alkyl groupstakes place between an ester and the solvent alcohol under theinfluence of metallic alkyloxides.Another instance is forth-coming43 in the case of ethereal oxalates, which can be intercon-verted by treatment with the appropriate alcohol containingpohssium hydroxide in solution. Reactions of esters, which inthe strictest sense are novel, have not been prominent recently,and, in a field so well explored, it is not surprising that much ofthe current work involving these compounds is of a semi-physicalnature and is largely concerned with isomerism or tautomericchanges. Thus, methyl formylphenylacetate has been very4 0 A.Michael, E. Scharf, and K. Voigt, J . Amer. Chem. SOC., 1916, 38,4 1 R. F. Brunel, ibid., 1917, 39, 1978; A , , i, 626.42 G. Griittner and E. Krause, Ber., 1917, 50, 202; A . , i, 256.43 N. C. Qua and D. McLaren, J . Amer. Chem. SOC., 1916, 38, 1803; A , ,653 ; A . , 1916, i, 361.1916, i, 709.D74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.thoroughly examined 44 aiid its reactions described in great detail.As in the case of the corresponding ethyl compounds, two modifi-cations have been isolated, and the a-form, which is remarkablystable, is regarded as possessing the enolic structureOH* CH: CPh*CO,hTe.The &form is likewise stable and does not seem to be readilytransformed into the more reactive a-isomeride, but perhaps themost valuable aspect of the work is the warning issued against' atoo ready acceptance of evidence as to structure which is basedon the colour reaction towards ferric chloride.When dissolved inmethyl alcohol, the enolic form of methyl f ormylphenylacetategives a positive result with the reagent, but the colour fades, anobservation wh%h might be attributed to conversion into the aldo-isomeride. The evidence, however, is, in this case, inconclusive,as a definite methyl alcoholate is formed which gives no colorationwith ferric chloride, although, in justice to the colour reaction, i tshould be stated that this additive compound is doubtless derivedfrom the aldo-form, and its formation is thus a proof of tauto-meric change.Our information on the ethereal formylphenyl-acetates is certainly becoming more definite, but the view thatisomeric forms attain a keto-aldo equilibrium in solution is notwithout its criti~s.~5Clear and well-defined evidence has now been obtained whichidentifies the labile hydrogen atoms involved when &diketones or&ketonic esters undergo enolisation. Selecting the test case ofthe compound hitherto termed ethyl diacetylmalonate, it has beenshown that the irregular constitution ascribed to the substanceis no longer tenable.The fact that many properties of the com-pound, both positive and negative, are not in agreement withthe formula [CH,:C (OH),],C( C0,E t)2 receives ready explanationfrom the suggestion that it is in reality the normal acetate ofenolic ethyl monoacetylmalonate, CH,* C (OAc) : C(CO,Et), . Theproof on which this claim is based involves the direct preparationof the substance by the acetylation of ethyl acetylmalonate, andalso the fact that the acetylation of ethyl propionylmalonate andthe propionylation of ethyl aoetylmalonate give rise to products,figured below, which are isomeric and not identical.Pro>& C<C02Et AcO>C:C<CO,EtMe CO, Et Et C02Et 'This disposes of a case, apparently irregular, in which enolisationhad involved hydrogen unattached to the carbon atom situated44 W.Wislicenus and pupils, Annalen, 1916, 413, 206 ; A , , i, 268.45 W. Dieckmann, Ber., 1916, 49, 2213; A., 1916, i, 820ORGANIC CHEMISTRY. 75between the carbonyl groups, and, in the paper quoted,46 convincingevidence is produced which refers ethyl acetylmalonate and acetyl-acetone to enolic structures of normal type.Still another explanation of the conversion of ethyl acetate intoethyl acetoacetat'e is rendered possible through the observationthat the latter compound is produced from dimeric keten by theaction of alcohol containing sodium ethoxide. On this basis, thesuggestion is made that the first effect of the sodium used in thereaction is to convert the simple ester into a metallic alcoholateof the keten type, CH,:C(ONa)*OEt.I n this coniiexion, it may beremarked that a considerable amount of research is being devotedto ketens generally, and a good case has been made for the claimthat dimeric ketens are not, after all, to be regarded as deriv-atives of cyclobutane-1 : 3-dione, although they may be readilytransformed into such conipounds.47 I n order to settle this point,various cyclobutanedione derivatives have been examined andfound to respond to the usual ketone reactions, and to differ inpractically every respect from the related dimerin, ketens. Furtherstudies have also been made of the polynierisation of ketens, andit has been shown that the introduction of the carboxyl groupenhances the instability of the compounds. Attempts, based onthis special reactivity, to pass directly from a keten-monocarb-oxylic ester into the corresponding cydobutane derivatives have,so far, met with no S U C C ~ S S , ~ ~ as substituted pyrones were formed.Work of this description is hampered not only by the experimentaldifficulties encountered and the instability of the products, butalso by the fact that the prediction of even the approximateproperties of the compounds is invested with much uncertainty.49~ 60The Sugar Group.The special feature of the past year's publications dealing withthe simpler sugars has been the renewed attention paid to opticalproperties, and more particularly to the phenomenon of muta-rotation.On first inspection, there could be no more unpromisingfield in which t o search for relationships between structure andoptical rotatory power, but the results accumulated during thepast ten years have strengthened the conviction that, in the sugargroup, configuration and specific rotation are simply related, andthus optical values may serve as a guide to constitution.4fi K.von Auwers and E. Auffenberg, Ber., 1917, 50, 929 ; A., i, 627.4 7 G. Schroeter and pupils, ibid., 1916, 49, 2697 ; A., i, 145.4 8 H. Staudinger and H. Becker, ibid., 1917,50, 1016 ; A., i, 629.4 s H. Staudinger and H. Hirzel, ibid., 1024 ; A., i, 630.H. Staudinger and H. Hirzel, ibid., 1916, 49, 2522 ; A., i, 178.D* 76 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A t the same time, mutarotation continues to display ever-increasing complications, but its study, as is inevltably the casewhere exact physical measurements are concerned, has resulted inthe development of improved methods for preparing and purify-ing the compounds examined.These considerations have beenapparent in directing niuch of the current work on sugars. Thus,it has been shown51 that glucose of exceptional purity may beobtained by using acetic acid as a crystallising medium, and that,moreover, either the a- or P-form may be separated by modifyingthe conditions of solution. I n the writer’s experience, the use of‘acetic acid is most effective, and, in the case of P-glucose, is some-what more convenient than the older method of crystallising frompyridine. The latter method, however, still continues to be usedAnother sugar preparation to which attention should be directedis that of mannose, which can be obtained by acid hydrolysis ofvegetable ivory, and may even be isolated in the solid form with-out the intermediate formation of the phenylhydra~one.~4 Thismarks a very substantial step, as research on mannose has alwaysbeen restricted by the comparative inaccessibility of the purecrystalline sugar.The above examples, although typical, do notby any means exhaust the list of improved methods of preparationwhich have recently been described, but they are sufficientlystriking to indicate one of the indirect benefits conferred by thestudy of mutarotation.Turning to some of the optical results which have been described,special interest will be taken in new data contributed in supportof Hudson’s generalisation affecting the molecular rotations of aand P-forms of sugars.The essential feature of Hudson’s view,namely, that the difference between the molecular rotations of thea- and P-forms of mutarotatory sugars is a constant, is now widelyaccepted, and has recently been put to the test in the case ofthirteen natural or synthetic sugars.55 The compounds selectedshow considerable diversity of type, yet, on the whole, the general-isation is well supported. Somewhat discordant results wereobtained with mannose, lyxose, and rhamnose, although, in thecase of the last-mentioned sugar, this is not surprising. It may51 C. S. Hudson and J. K. Dale, J . Amer. Chem.SOC., 1917, 39, 320; A . ,i, 320.52 A. W. Mangam and S. F. Acree, ibid., 965 ; A., i, 446.53 J. E. Mackenzie and S. Ghosh, Proc. Roy. Soc. Edin., 1916, 36, iii, 204 ;64 C. S. Hudson and H. L. Sawyer, J . Amer. Chena. Soc., 1917, 39, 470;5 5 C. S, Hudson and E. Yanovsky, ibid., 1013 ; A., i, 445.successfully.~2~ 53A . , i, 79.A . , i, 321ORGANIC CHEMISTRY. 77be remarked that the initial values of the specific rotations quotedin the paper were arrived at by the indirect method based onsolubility measurements,56~ 57 and new maximum values have inthis way been attached to several comiiion sugars.An important extension of Hudson's views is marked by theappearance of a paper58 in which the specific rotations of thephenylhydrazides derived from acids related to the sugars arecompared. Analysis of the data shows that the asymmetric systemattached to the a-carbon atom exerts a preponderating influenceon the activity of these compounds and determines the sign of therotation.The result has been substantiated from othersources,59~60 and another example has thus been added to the casesin which the polarimeter serves as a guide to structure. Thesearch for simple optical generalisations of this nature is a develop-ment' which is certain to attract many workers, and signs are notwanting that the quest is being extended.61With regard to the action of reagents on simple sugars, thereis little to report. Attempts to isolate definite thio-derivatives ofglucose have been continued, but have met with scant success.62On the other hand, in a closely related topic, an interesting resulthas been obtained in decomposing glucose ethylmercaptal by onemolecular proportion of mercuric chloride,63 The reaction yieldeda crystalline ethylthioglucoside, which presumably has thestructureOH*CH,*CH(OH)*CH.[C Fl*OH],*CH*SEtand a considerable enlargement of the chemistry of glucosides mayquite conceivably result from this single observation.Mention should perhaps be made a t this stage that full work-ing details of the method of degrading sugars, by the action ofsodium hypochlorite on the amides of the corresponding acids, arenow available in an accessible form.The process has been referredto in previous Reports, and, considering the excellence of themethod, an account of the working conditions will be welcomed.64Little support will be given by workers in this field to the popularI ()--I5 6 C.S. Hudson, ,J. Amer. Chern. Soc., 1904, 26, 1065; A . , 1904, i, 974.5 7 T. M. Lowry, T., 1904, 85, 1551.5 8 C. S. Hudson, J. Anzer. Chem. Soc., 1917, 39, 462; A . , i, 318.5 9 P. A. Levene and G. M. Meyer, J. Biol. Chem., 1917,31, 623 ; A., i, 631.Go R. A. Weermnn, Rec. trav. chim., 1917, 37, 52 ; A., i, 548.E. Bourquelot, Cornpt. rend., 1916, 163, 374 ; A . , 2916, i, 792.G 2 W. Schneider, Ber., 1916, 49, 1638 ; A . , 1916, i, 791.63 W. Schneider and J . Sepp, ibid., 2054; A., 1016, i, 792.64 R. A. Weerman, Rec. trcrv. chim., 1917, 37, 16 ; A., i, 54078 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.impression that sugars are readily characterised by means of theirosazones, and it is not surprising to find that research is stillapplied to the discovery of well-defined sugar derivatives suitablefor identification.p-Tolylhydrazine has been used to someextent,65. G6 but many of the products show an undesirable tendencyto melt, a t practically the same temperature. This objection doesnot apply so forcibly to the use of diphenylmethanedimethyl-dihydrazine, which appears to act in precisely the cases in whichphenylhydrazine gives inconclusive result~.~79 63The discovery of two new natural sugars is in itself noteworthy,but particularly so when both compounds belong to t,he heptoseseries. From the aqueous extract, of the avocado pear, a crystal-line mannoketoheptose has been isolated which shows the normalproperties of a reducing sugar, although it has not yet beenseparated into mutarotatory forms.69 Complete evidence as tostructure was obtained by reduction and osazone formation, andpoints to the configurationH H OHOHOI I I1 OH o ~ ~ , - L ~ - ~ - .OH dH €!I J!IThe sugar is not fermentable by yeast, and the same holds truefor sedoheptose, which has been isolated from the leaves and stemsof Sedum spectabile.7Q Not the least interesting feature of thelatter heptose is the apparent ease with which it is converted intoan anhydro-derivative by processes which are much less drast,icthan those necessary for the formation of an hydroglucose.Although during the past year research on standard lines hasobviously been somewhat limited so far as reducing sugars areconcerned, much attention has been paid to problems which havea more immediate bearing on existing conditions.Of these, onlyone need be mentioned here. Commercial syrupy glucose has longh e n recognised as a highly complex mixture, but it will come asa surprise t o many to learn that the glucose content of averagesamples may be as low as 12 per cent., and that the proportionof maltose present generally exceeds that of glucose.716 5 A. W. van dsr Hear, Rec. trav. chim., 1917, 36, 346 ; A., i, 380.6 6 Ibid., 1917, 37, 108; A . , ii, 515.6 7 E. Vot.oZek, Ber., 1917, 50, 35 ; A . , i, 250.6 8 J. von Braun, ibid., 42 ; A., i, 251.F. B.La Forge, J . Biol. Chem., 1917, 28, 511; A., i, 118.7 0 F. B. La Forge and C. S. Hudson, ibid., 30, 61 ; A., i, 444.71 J. A. Wesener and G. L. Teller, J . Ind. Erzg. Chem., 1916, 8, 1009; A.,i, 7ORGANIC CHEMISTRY, 79Glucosides.The synthesis of glucosides by the agency of tetracetylbromo-glucose still gives profitable results, and the work is marked byone or two features which are worthy of note.Mention should be made, in the first instance, of the successattending Fischer’s efforts t o synthesise mandelonitrile-glucoside:which has been obtained in the racemic form and also in the d-and Z-varieties. The key to the synthesis is the use of ethyl61-mandelate in the reaction with tetracetylbromoglucose, a pro-ceeding which limits the condensation to the hydroxyl group.Thereafter, the racemic product is converted into the mixture ofamides, which are separable by crystallisation into the two activeforms. After dehydration, so as to produce the correspondingnitriles, the acetyl groups are removed by the action of ammonia,and, although the change is accompanied by racemisation, thisenabled the resulting dZ-mandelonitrile-glucoside to be identifiedwith natural prulaurasin.The ultimate resolution does not seem to have been undulytroublesome, and both d- and Z-mandelonitrile-glucosides wereultimately obtained.The former proved to be identical withsambunigrin, and this result by no means exhaush the featuresof a highly important paper.72As is well known, when tetracetylbromoglucose enters intoreaction with an alcohol or phenol, the liberated hydrobromic acidgenerally effects the gradual removal of the substituting acetylgroups, and thus complex mixtures are formed which are trouble-some to separate.To overcome this difficulty, quinoline, or evensoluble alkaloids, may be employed, and the efficiency of the formerreagent is well marked in some of the recent work described byFischer. For example, the glucosides of phenol,73 menthol, andresorcino174 have been obtained by this method, and it wouldappear that the work is being carried out with the ultimate objectof preparing glucosides of physiological importznce. This is amost desirable development, as only too frequently the synthesisof glucosides appears to be directed merely to the preparation ofnew compounds of little permanent value.A t the same time, theidea that glucosides are uniformly more reactive physiologicallythan the parent substances has not been well maintained, and tothe numerous exceptions already recognised may be added the case74 E. Fischer and M. Bergmann, Ber., 1917, 50, 1047; A , i, 657.73 E. Fischer and L. von Mechel, ibid., 1916, 49, 2813 ; A., i, 216.7 4 E. Fischer and M. Berpann, i b i d . , 1917’; m, 711 ; A., i , 46780 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the glucoside of dihydrocupreine.75 Although they are interest-ing compounds, the alkaloidal glucosides as a class have been butlittle studied, and this is not surprising, as, judging from results,their examination by ordinary methods can give but littlesatisf action.76A slight variation of the customary type of glucoside synthesisis introduced by the interaction of tetracetylbromoglucose withthe silver salts of organic acids.The acetylated glucose estersthus produced are peculiarly prone to undergo hydrolysis, andattempts to remove the acyl groups result,ed in complete ruptureof the complexes. The work has nevertheless yielded one interest-ing observation, in that, when silver salicylate is used in the con-densation, two isomeric substances are formed.77 Of these, oneis the expected salicylate of tetra-acetylglucose, whilst, the otheris a salicylic acid tetra-acetylglucoside. From this result, thereasonable conclusion is drawn that silver salicylate exists in twomodifications,and, in view of the behaviour generally of the silver salts ofhydroxy-acids, it would actually appear that, in such compoundsthe metallic atom is distinctly labile and can react either in thecarboxy- or hydroxy-posit,ion .Disaccharides and Polysa cc harides.Authentic syntheses of disaccharides by biochemical agency ismaking gradual progress, and the results will be more widelyappreciated now that definite crystalline compounds are beingisolated from syrupy mixtures.The characterisation of twomutarotatory galactobioses 7 8 9 79 marks a distinct step and givespromise that, in this way, more light will be shed on the complexproblem of how monosaccharides are structurally linked. Alreadythere seems good grounds for the belief that our blackboard illus-trations will soon require modification in this respect.Otherresearch on disaccharides has, on the whole, followed normal linesand discloses few outstanding features.One exception to this statement is presented by t,he synthesis7 5 P. Knrrer, Ber., 1916, 49, 1644; A . , 1916, i, 832.7 6 A. Heiduschka and H. Sieger, Arch,. Pharm., 1917, 255, 18 ; A., i, 407.7 7 P. Karrer. Ber., 1917, 50, 833 ; A., i , 539. '* E. Bourquelot and A. Aubry, Compt. rend., 1917, IW, 521 ; A . , i , 250.7 9 Ibid., 443, A., i, 250ORGANIC CHEMISTRY-. 81of the sulphur and selenium analogues of isotrehalose.80 Startingfrom that invaluable reagent tetra-acetylbromoglucose, the actionof potassium hydrogen sulphide in alcoholic solution couples thetwo hexose residues through the sulphur atom, and, by the agencyof alcoholic ammonia, the acyl groups were then eliminated.Thethioisotrehalose thus formed is a definite crystalline compoundwhich is notably stable towards mineral and organic hydrolysts,and the same holds true for the corresponding selenium derivative.Even admitting that the formation of these disaccharide analoguesappears to have been accidental, their discovery is not, withoutimportance.From year to year great variation is shown in the number ofpapers dealing with polysaccharides, and the period under reviewhas been more fruitful than usual, although, naturally enough,the results described are often vague and obscure. Among themore definite investigations may be noted a further study of thetrimethylglucose obtained from methylated cellulose by hydro-lysis.R1 The compound in question may be regarded as a frag-ment' of the cellulose complex in which the original hydroxylgroups are alkylated, and thus the structure becomes an importantconsideration. For various reasons, the constitution is repre-sented by0 M e*CH,*CH (OH) CH.CH (0 Me). C H (OM e) - C He OHI 0 Iand a distinct advance has been made in relegating the compoundto the butylene-oxide type.As has recently been the case, publications on the chemistry ofstarch have been fairly numerous, but the results are less definitethan t'hose to which reference was made in last year's Report.The suggestion that formaldehyde may display diastatic proper-ties towards starch82 has been vigorously disp~ted,~3 and haselicited in reply a tabulation of the evidence in favour of theview.84 Considering, however, the fact that the action of form-aldehyde on simple disaccharides85 or on hexoses is still obscure,it would appear that, even if the diastatic action is substantiated,little progress will have been made in studying the degradationof the polysaccharide.W.Schneider and F. Wredo, Bey., 1917,50, 793 ; A . , i, 540.81 W. S. Denham and Miss H. Woodhouse, T., 1917, Ill, 244; A., i, 320.82 G. Woker, Ber., 1916, 49, 2311 ; A . , i, 61.83 W. von Kaufmann, ibid., 1917, 50, 198; A . , 1, 251.84 G. Woker, ibid., 679 ; A . , i, 447.8 5 A. Heiduschka and H. Zirkel, Arch. Pharm., 1916,254, 456 : A , , i, 44682 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Optical Activity.As stated in the preceding section of this Report, much recentwork on optical activity has been concerned with members of thesugar group, and as many of the results have a structural appli-cation, they are appropriately described under carbohydrates.With reference to optical activity generally, somewhat new groundis being opened up by the collection of data as to the specificrotations of optically active ketones and diketones, but the workhas not proceeded far enough .to render possible more than quali-tative relationships between structure and rotatory power.R6 I nother fields, however, a number of definite observations have beenmade, and in the first instance attention may be directed to thesuccessful preparation of diaminoglycerol in d- and I-forms.87Inspection of the Reports for the past two years will give an ideaof the research of which this forms part, and of the special difficul-ties encountered in previous attempts to obtain the desired activecompound.Starting from optically active glycerol ap-dibromohydrin, reac-tions designed to displace the halogen atoms by amino-groupsresulted uniformly in the destruction of the asymmetric system.*This difficulty has now been got over by deferring resolutionuntil after the intsoduction of the amino-groups into the requiredpositions, so that the synthetical scheme commences with methylally1 ether. The various stages are summarised below:CH,:CH*CH2*OMe 1: CH2Br*CHBr-CH,*OMe alcoholicNH3 +inactive CH,( NH,)*CH(NH,)*CH,*OMe +d- or Z-CH,( NH2)*CH(NH,)*CH,*O~e ;zd- or Z-CH2( NH,)*CH(NH,)*CH,*OH.The reaction between thO dibromohydrin and ammonia gave verypoor yields, and the resolution, which was carried out on thediaminomethoxypropane, appears to have given trouble, but theresult is a triumph over a combination of severe experimentaldifficultiee.The appreciation of the writer is in no way diminishedby the fact that, some years ago, in an attempt to solve the con-stitution of glycerol methyl ether, he attempted precisely the sameseries of reactions, but without success.86 H. Rupe and S. Wild, AnnuZen, 1917,414, 111 ; A,, i, 538.13' E. Abderhalden and E. EichwaId, Ber., 1916,49, 2095 ; A., 1916, i, 795.* In the Report for 1916 (p.74) the inactive diaminohydroxypropaneobtained by Abderhdden was incorrectly described as being internallycompensated, a mistake for which the writer of the Report is alone responsible.-J. C. IORQANIC CHEMISTRY. 83The application of physical methods to the study of opticalactivity is on the increase, and is contributing to the formationof clearer views as to the mechanism of optical inversions. Underthis heading, reference should be made t o some results obtainedin converting active bromosuccinic acid into the correspondingthiolmalic acids and xanthosuccinic acids. I n the case of thelatter compounds, the reaction has been shown88 to proceed intwo different ways, one direct and the other through the inter-mediate agency of the active lactone of malic acid.d-xanthosuccinic acidAI-Bromosuccinicacid ---.d-malolactone -2 Z-xanthosuccinic acid.Reaction A is thus one of direct substitution, whilst B involvesaddition of potassium xanthate to the lactone. The two reactions,although simultaneous, proceed at different speeds, and the changecan be controlled so that successive crops of the product show adiminishing dext,rorotation until ultimately the sign of activity isreversed. Obviously in one of these competing reactions a stereo-chemical change must take place, and, as the result of a carefullyconceived series of tests, the conclusion is drawn that the changein question occurs during the direct replacement of bromine.I-CO,H*CHBr*CH,*CO,H + KS*CS*OEt +d-C 02H C H ( S C S o 0 E t) CH,.C0,H.Most of the results summarised above are based on the determina-tion of reaction velocities, but other physical measurements canalso be used to good effect in studying optical transformations.Thus, as an extension of previous work on similar lines, thesystematic determination of the dissociation constants of phenyl-bromoacetic and phenylbromopropionic acids has been under-taken*99g0 as part of a general study of the Walden inversion.I n this connexion, attention should be directed to fresh resultson the effect of solvent media in influencing these optical changes.Taking as a test case the conversion of phenylchloroacetic acidinto the corresponding amino-compound, the reaction has beenconducted in twelve different solvents, with results which showthat inversion occurs in half of the examples studied.Thebehaviour of water and liquid ammonia as solvents is showngenerally to be similar, although, in the latter case, the pre-8 8 B. Holmberg, Arkiv. Kern. Min. Geol., 1916, 6, No. 8 ; A., i, 115.8 R G. Senter and S. H. Tucker, T., 1916,109, 690; A . , 1916, ii, 524.G. Senter and G. H. Martin, $bid., 1917,111, 447 ; A . , ii, 30184 ANNUAT, REPORTS ON THE PROGRESS OF CHEMISTRY.dominant reaction is accompanied by the formation of iminodi-phenyldiacetic acid .91Many synthetical possibilities are involved in the use of optic-ally active glyceraldehyde, and some recent, results are worthy ofnote. It appears 92 that d-glyceraldehyde dimethylacetal is some-what more stable than might have been expected from the natureof these compounds, and, for complete hydrolysis, requires theuse of 0.1 N-sulphuric acid a t 50°.The active product' thusobt,ained, when subjected to the cyanohydrin reaction and sub-sequent hydrolysis, gives a mixture of active acids. On oxidationof the primary alcohol group, &tartaric acid is the only activeproduct isolated, so that it is now possible t o correlate the activeglyceraldehydes with d-glucose and to apply to the former com-pounds the expressions d- and I-, according to the conventionalsystem. As the dextrorotatory form of the aldehyde is the varietywhich gives Z-tartaric acid, it is regarded as the d-compoundrelated to d-glucose.Even to those who have no personal experience in work onoptical activity, i t must be evident that few branches of researchpresent greater difficulties.Inversion effects, racemisation, andthe uncertainty of deciding when a compound is optically pure oroptically homogeneous, are obstacles which frequently have to befaced, but when special experimental difficulty is encountered inthe preparation of test compounds, the prospects are notencouraging. The latest contribution to the optical study of thediphenylsuccinic acids furnishes a case in point, as work designedto convert the meso-ester into a mixture of the active acids in un-equal amounts broke down through the unexpected stability ofthe Z-menthyl esters. Not only so, but the formation of the normalmenthyl esters of the active acids was accomplished only in onecase, and even such a trustworthy reagent as thionyl chloridefailed to overcome this difficulty.93Nitrogen Compounds.During the period now under review, publications dealing withnitrogen compounds have been numerous, and it has been a matterof more than usual difficulty to draw even an approximate linewhere true aliphatic compounds end and heterocyclic compoundsbegin.The policy, recently followed, has therefore been con-91 G. Senter and H. D. I<. Drew, T., 1916,109, 1091 ; A . , 1916, i , 525.92 A. Wohl and F. Momber, Ber., 1917, 50, 455; A., i, 319.93 H. Wren and C. J. Still, T., 1917, 111, 513 ; A., i, 456ORGANIC CHEMISTRY. 85tinued of limiting consideration, as far as possible, to compoundswhich are essentially open-chain structures.The preparation and study of simple amines has occupied aprominent place in recent literature, and reference has alreadybeen made to an explanation which has been put forward t oaccount for the formation of mono- and di-methylamines by theagency of formaldehyde.I n addition, the method of preparingamines which is based on the interaction of potassium phthalimideand chloro-compounds has been considerably modified as the resultof the observation that, when applied to a-chloro-n-propyl alcohol,the product formed is a derivative, not of isopropylamine, but ofn-propylamine. Investigation of this abnormal reaction hasshowng4 that the first stage is the removal of hydrogen chloride,with the consequent formation of propylene oxide, which thencombines additively with a molecule of phthalimide.0/\CH,*CHCI*CH,*OH + CH,*CH-C:H, +CH; CH(0H) C H, N H,.This has resulted in the use, in the same general reaction, of pre-formed alkylene oxides, several of which have been found to reactwith potassium phthalimide 95 to give ultimately primary amines.By the use of such compounds as epichlorhydrin in place of anunsubstituted oxide, a phthalimide derivative of the typeis obtained, and as chlorine can be readiIy disphced by brominein this compound, i t will a t once be seen that the syntheticalpossibilities thus opened out are very numerous.Other routes t obrominated amines are, of course, possible, and, in example, thecases may be cited in which bromoethylamine96 and bromoiso-propylamine 97 have been prepared from the corresponding amino-alcohols. Before leaving the subject of amines, it may perhapsbe noted that fresh complications have been added to the problemas to the function of small quantities of iron and free acid inreducing nitro-compounds.It has been stated98 that nitro-paraffins are reduced to the corresponding amines by this agency,B4 S. Gabriel and H. Ohle, Ber., 1917, 50, 804 ; A., i, 563.95 S. Gabriel and H. Ohle, ibid., 819; A., i, 565.O 6 S. Gabriel, ibid., 526 ; A., i, 541.O 7 S. Gabriel, ibid., 1916, 49, 2120 ; A., 1916, i, 794.H. Krause: Chem. Zeit., 1916, My 810; A., 1916, i , 79386 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.even when the system is allowed to become alkaline, and in suchcases it is evident that ferrous hydroxide rather than ferrouschloride must be regarded as one of the effective reducing agents.So far as efficiency is concerned, the process mentioned above isin no sense inferior to catalytic methods for reducing nitro-com-pounds.I n this connexion, mention may be made of the indirectproduction of primary amines from alkyl nitrites, by reductionunder conditions which lead t o the transient formation of thecorresponding nitro-compounds .99Considering the importance of reactions involving silver saltsand alkyl haloids, and the so-called ‘‘ abnormalities ” displayed bysilver cyanide in particular, new ideas on the structure of thelatter compound are welcome.From the fact that silver cyanideand methyl iodide react a t the ordinary temperature t o give(AgNC),,MeI, whilst a t 40° the product contains an additionalmolecule of the haloid, and is doubtless (AgNC,CH,I),, the sug-gestion has been inadel that the silver salt may be represented bythe structure Ag*N:C:NeAg. This idea certainly accounts forthe successive addition of two molecules of methyl iodide, andappears t o be consistent with many other reactions of the salt.Considerable interest will be taken in the marked revival ofwork on aliphatic diazo-compounds, no fewer than eleven con-secutive papers on this subject being contributed by Staudingerand his pupils. I n dealing with a mass of experimental results,which is almost unwieldy, the desirable policy has been followedby the author of prefacing the series of publications by a generalintroduction .2The methods of preparation adopted involved either the use ofnitrosomethanes on modified lines or the mild oxidation ofappropriate hydrazones, and the properties of a considerablenumber of new diazo-compounds have now been described.Mostof these are substituted diazoniethanes, and special attention hasbeen paid to diphenyldiazomethane, which appears to be com-paratively stable.3Although it readily gives the normal reactions of such com-pounds, attempts t o utilise the reagent for the production ofdiphenylsulphen met with no success. Nevertheless, in order t oaccount for the products actually formed, a suggestive structuralC9 9 P.Neogi and T. C. Chowdhuri, T., 1917, 111, 899 ; A., i, 686.E. G. J. Hartley, ibid., 1916, 109, 1296; A., i, 83.H. Staudinger, Ber., 1916, 49, 1884; A., 1916, i, 847.H. Staudinger, E. Anthes, and F. Pfenninger, ibi&., 1928; A., 1916,i, 861ORGANIC CHEMISTRY. 87scheme has been forthcoming which involves the transient forma-tion of the desired CPh,:SO,.4 Research 011 a number of consti-tutional problems has also been undertaken in the course of thework, and amongst these may be mentioned a study of the actionof hydrogen sulphide on diazo-compounds generally. The fact thatunder the influence of this reagent most diazo-compounds arereduced to hydrazones has in the past been used as an argumentfor assigning derivatives such as diazo-anhydrides t o a differentstructural type.It is now shown, however,5 that, in addition tohydrazone formation, ot'her reactions resulting in the productionof thiols or thiodiazole derivatives may occur, and, such being thecase, there seems no good reason for discriminating sharply betweentrue diazo-compounds and diazo-anhydrides. Another ingeniousstructural scheme has been used as the basis of attempts t osynthesise a second form of diphenylenediazomethane, and thussecure a representative for each of the rival formulze:This, unfortunately, broke down,6 but the results may be inter-preted as furnishing additional arguments for the open-chainstructnre.The action of acid chlorides on diazo-esters has also beenstudied,7 and the reaction given by ethyl diazoacetate appears t obe typical in that two ester molecules react unequally, as shownbelow :It is evident t,hat, in the aliphatic diazo-series, generalisations arehard to find.Great variety is shown even in the colour of thecompounds, but there seems to be no definite relationship betweencolour and stability, so that even in this respect speculations onstructure have been necessarily restricted. Our views of the con-stdtution of these compounds are thus still uncertain, and i fStaudinger is content to compromise between the cyclic and open-chain types, few will be inclined to dispute his opinion.Another lengthy series of papers, dealing particularly with theazides and hydrazides of aliphatic hydroxy-acids, has appearedfrom Curtius' laboratory. The usual methods of preparation havebeen adopted and the results are normal, but, in the case of lower* H.Staudinger and F. Pfenninger, Ber., 1916, 49, 1941 ; A., 1916, i, 852.a H. Staudinger and A. Gaule, ibid., 1961 ; A., 1916, i, 853. ' H. Staudinger, J. Becker, and H. Hirzel, ibid., 1978; A,, 1916, i, 865.H. Staudinger and J. Siegwart, ibid., 1918 ; A., 1916, i, 84988 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.members, the actual products are ill-defined, although their deriv-atives crystallise well.* This naturally places restrictions ondetailed discussion.Carbamides.-From a publication which appeared during theyear,g i t would seem that the reaction between nitrous acid andcarbamide has been too readily accepted as following the usualcourse in which primary amino-groups are eliminated by thisreagent. In the particular case of carbamide, nitrogen and carbondioxide should be evolved in the volumetric proportion of two toone, but in practice this is never realised, thus pointing either toan entirely different mechanism of reaction or to the occurrence,in notable degree, of scondary changes in which part of thenitrogen is retained.The decomposition with nitrous acid, more-over, only takes place in the presence of an acid which combineswith urea, so that, strictly speaking, the reaction is confined tosalts. I n addition, cyanic acid has now been detected as one ofthe primary products of the change, and this intermediate com-pound may undergo subsequent decomposition, the nature of whichvaries according to the conditions.Under the action of excessof nitrous acid, carbon dioxide and nitrogen are eliminated, butwith low concentrations, ammonia is formed by simple hydrolysis.The combined results are held to be consistent with the ring struc-ture for urea, but the whole problem of the reaction betweennitrous acid and cyclic compounds conforming to the betaine typeis beset with difficulties.The equally complex problems presented by thiocarbamide havealso been the subject of considerable research, m d the number ofadditive salts isolated has been enlarged,'(' whilst the reactionbetween thiocarbamide hydrochloride, and acetaldehyde has beenascribed t o a curious change in which the salt-forming acid mole-cule migrates from the base t o the aldehyde.11 These observationson saltrformation are of import'ance as a further step towardslocalising the intramolecular changes in thiocarbamide, and havebeen considerably extended in another paper,12 to which appreci-ative reference should be made.Additive compounds of thio-carbamide and alkyl haloids have been known and studied for aconsiderable time, and it has now been shown that the alkyl saltsof inorganic acids are similarly capable of direct union with thebase. On the other hand, esters of organic acids do not combine8 T . Curtius, J . pr. Chem., 1917, [ii], 95, 168; A . , i, 635.E. A. Werner, T., 1917, 111, 863; A . , i, 639.lo A. E. Dixon, ibid., 684 ; A ., i, 546.11 A. E. Dixon and J. Taylor, ibid., 1916,109, 1244; A , i, 11.l 2 J. Taylor, ibid., 1917, 111, 650; A., i, 514ORGANIC CHEMISTRY. 89directly with thiocarbamide, but this difficulty has been overcomeby double decompositions in which thiocarbamide methyl sulphatehas been successfully employed. The structure of these additivecompounds admits of at’ least three possibilities, but strong evidenceexists which favours the constitutionwhere R denotes an alkyl group. Another interesting feature ofthe same paper is the isolation of thiocarbamide benzyl sulphatein a new form, which is interconvertible with the varietypreviously known. This result does not stand alone by any means,but the isomeric varieties of these and similar derivatives may besatisfactorily accounted for by reference to “sulphonium ” orammonium ” types.Further evidence bearing on the constitution of thiocarbamideand related compounds is furnished by the somewhat unexpectedreactions which they display towards mercuric nitrite.13 Thechanges undergone are complex, and in the particular case of thio-carbamide involve the successive reaction of two molecules of themetallic nitrite, followed by the disengagement of nitrous anhydride.Incidentally, it may be remarked that one outcome of the worknow referred to is the isolation of definite compounds containingseveral sulphur atoms in direct attachment, and in which interest-ing examples of the variations in the sulphur valencies can betraced.Turning to a related subject, it has been found that when thio-carbamide is dissolved in aqueous alcoholic ammonia, and is there-after treated with mercuric oxide, guanidine is formed in smallquantities in addition to polymerised cyanamide.The lat,ter com-pound originates in monoineric cyanamide, some of which evidentlyescapes polymerisation through reaction with ammonia.14 Thesechanges are best explained by the adoption of the formulaNiC-NH, for cyanamide, and this view is strongly support.ed bythe molecular refraction values determined for cyanamide and itsalkyl derivat ives.15Anzino-acids.-In last year’s Report, brief reference was madeto work which had been commnced on the action of chloroamineson proteins and amino-acids, and a further publication on similarlines is forthconiing.16 It is now evident that “ chloramine-T ’’has to be regarded as a chemical reagent of considerable utility, andl3 P.C‘. Rby, T., 1917, 111, 1 0 1 ; A . , i, 194.l1 E. Schmidt, Arch. Pharm., 1016, 254, 626 ; A . , i, 449.E. Colson, T., 1917, ill, 554 ; A . , i, 445.l6 H. D. Dakin, Biochem. J., 1917, 11, 7 9 ; A., i, 5490 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.may well play a useful part in the formation of compounds whichare somewhat inaccessible. Thus, sodium glutamate may be con-verted into either P-aldehydopropionic acid or P-cyanopropionicacid, according to the proportions of the reagent used, andnumerous other examples are quoted which indicate t h a t by thisagency semi-aldehydes may be rendered more available.Before leaving the subject of the decomposition of amino-acids,mention may be made of a related topic which, although belongingto another section of this Report, should not pass unnoticed.Thepoint will not be disputed t h a t future developments in the chem-istry of proteins will depend largely on improvements in conduct-ing the fermentative degradation of polypeptides, as i t is only byselective graded hydrolysis t h a t the overwhelming isomerism ofsuch compounds is likely to be elucidated. Although these com-plexities are generally recognised, the point is emphasised byrecent calculations of the number of possible isomeric forms ofsimple polypeptides.17 Special interest is thus attached to thesystematic attempt now being made to secure accurate conditions,controlled by physical methods, under which enzyme action 011polypeptides should be conducted.l*It is satisfactory that the revival of synthetical work in thisfield still continues.Two years ago, reference was made to theimproved method of obtaining the N-methyl derivatives ofd-alanine and related acids under conditions which exert no dis-turbing influence on configuration. This opens out the possibilityof a partial resumption of synthetical work without the indecisionas to structure attending all reactions which may be accompaniedby Walden inversions. Thus, Z-a-bromopropionic acid reacts withmethylamine19 in the same steric sense as with ammonia, as it givesZ-N-methylalanine. Several other examples are quoted which givepromise t'hat, i n the synthesis of amino-acid complexes, somecontrol may be maintained of the configuration changes involved.As is well known, during the hydrolysis of natural proteins,varying amounts of carbon dioxide and animonia are formed, andalthough there are many potential sources of these products,analogous cases are furnished by synthetic polypeptides of amodified nature. As an issue of investigations on acid azides,complexes have been isolated which contain diamides coupled withamino-acid residues, and these compounds on hydrolysis giveammonia, amines, and carbon dioxide, i n addition t o the parentE.Fischer, Zeitsch. physiol. Chern., 1917, 99, 54 ; A., i, 381.E. Abderhalden and A. Fodor, Permentforschziny, 1916, 1, 533 ; it.,i, 306.l9 E. Fischer, and L.von Mechel, Ber., 1916, 49, 1355 ; A., 1916, i, 802ORGANIC CHEMISTRY. 91amino-acids. This observation has led to the synthesis of newexamples of such complexes, the experimental method followedbeing a combination of two known processes. Starting from anacid azide, this is converted into the corresponding carbimide,which, in turn, is coupled with the ester of an amino-acid. There-after, by consecutive formation of the hydrazide and azide, a newcarbimide is obtained, which is capable of further reaction witha second amino-acid molecule. The steps of the synthesis areillustrated below in the case of a typical example:Hippuric acid + CH2(NHBz)*CO*?JH.NH, -+CH2(NHBz)*CO*N3 + CH,(NHBz)*XN:CO ethglglyci;;eCH,( NHBz)*NH.CO*NH*CH2*C0,Et.The free ester group in the last compound formulated above isthen converted into the corresponding acethydrazide, on which theseries of reactions can be recommenced .20 The scheme is certainlyingenious as a variation of ordinary polypeptide synthesis, andthe products behave on hydrolysis in the expected manner, in thatcarbon dioxide and ammonia are produced in addition to thenormal products.Another example of the preparation of amixed ” polypeptide is furnished by the successful synthesis oftyrosy3glycine-hydantoin,21 and, in this case also, hydrolysis givesa series of products closely resembling those obtained lrom proteins.Much sympathy will follow the examination of known poly-peptides and the preparation of new representatives, which has asits object the identification of the precise position in the moleculeoccupied by any pa.rticu1ar amino-acid residue.The constructiveunits of the scheme are thus amino-acids, which possess diagnosticreactions suitable for identification purposes, but, in addition,attempts are being made to determine the position of free amino-groups in the complexes.22 This is accomplished by introducingthe naphthalenesulphonyl group into the amino-position, and asthe substituting group is not readily removed by hydrolysis, itpersists in the cleavage products. To take a case in point, ifdiglycylcystine is converted into the corresponding di-B-napht halene-sulphonyl derivative, treatment of the latter with hydrochloricacid gives cystine and ,f3-naphthalenesulphonylglycine. This a tonce indicates that the glycyl residues in diglycylcystine preservethe amino-groups intact.The process bears a certain resemblance? O T. Curtius, J . pr. Chem., 1916, [iij, 94, 55 ; A . , i, 199.B. Johnson and Miss D. A. Hahn, J . Amer. Chem. Soc., 1917, 39,23 E. Abderhalden and E. Wybert,, Be?., 1916, 49, 2449, 2838 ; A . , i: 119.1255; A . , i, 47592 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,to the method of establishing the structure of sugar derivatives bymethylation, followed by hydrolysis.After tedious synthesis, it' is often the fate of an organic com-pound to be promptly destroyed, and this seems to have been thecase with a number of synthetic betaines* of the typeK*YH-YON(Me);OWhen decomposed by heating, these compounds invariably yielda-unsaturated acids, and this is a result not without significance, asacids of the same class are common plant products which aregenerally associated in the living organism with tertiary amines.I n all probability, the future study of betaines will do much tothrow light on the fate of nitrogenous compounds in plants andthe mechanism of their transformations.I n closing this section of the Report, it should be stated thataccess to most of the original papers has been restricted, and i thas been neoessary in many cases to work almost entirely from theabstracts.Whenever possible, these have been compared with theoriginals, and the writer feels that, on this occasion, as in each ofthe preceding four years, he owes much to the abstractors.Itmay not be out of place to express this indebtedness.JAMES COLQUHOUN IRVINE.PART II.-HOMOCYCLIC DIVISION.Reactions.Halogenation.-Bromiiiation and iodination of aromatic hydro-carbons can 'be effected readily by the action of bromine and iodinein the presence of nitric acid,l whilst iodination of phenols andnitrophenols can be carried out in quantitative yield by means ofnitrogen iodide or by a solution of iodine in potassium iodide incon junction with ammonia.2Reduction.-The wider use of ferrous sulphate and ammonia forreducing nitro-compounds has been advocated: and reduction inR. L. Datta and N. R. Chatterjee, J. Amer. Chem. Soc., 1916, 38, 2545 ;*'j S.Koma4tsu, Mena. Coll. Sci. Kgr?td, 1916, 1, 369 ; .4., i, 1.79.1917, 39, 435 ; A . , i, 15, 327.a R. L. Datta and N. Prosad, ibid., 441 ; A., i, 332.W. A. Jacobs and M. Heidelberger, ibid., 1435 ; A., i, 559ORGANIC CHEMISTRY. 93concentrated sulphuric acid by means of aluminium powder hasbeen studied.* It has been found that in the electrolytic reductionof aromatic nitro-compounds the yield of aminohydroxy-compundsis increased and that of amino-compounds correspondingly dimin-ished by the use of a cathode of two or more metals. I n the case ofnitrobenzene, a plain lead cathode gave paminophenol and anilinein the proportion of about 2 to 3, whilst a copper cathode withlead in the electrolyte gave them in the proportion of 5 o r 6 to 1.5Secmdary A ry1arnines.-The preparation and purification ofmonoalkylated aromatic ainines have been investigated.The pre-paration may be effected by treating the amine with an aliphaticaldehyde in the presence of a reducing agent in a medium notpossessing a strongly acid character, when the resulting anhydro-aldehyde-amine, or Schiff base, is simultaneously reduced to theinonoalkyl aromatic aniine ; aniline and formaldehyde thus givemethylaniline when reduced with zinc dust and sodium hydroxide."I n the preparation of secondary arylamines by the condensationof a primary amine with an alcohol, the product is always con-taminated by some unchanged primary amine, which is often diffi-cult t o remove owing t o the proximity of the boiling points of thetwo compounds.It has now been found7 that separation can beeffected by heating the mixture with ethyl oxalate and fractionat-ing the product, the primary amine yielding an oxamic ester,ArNH-CO*CO,Et, of higher boiling point, whilst the secondaryaniine remains unchanged,Aryl-substituted Aliphatic Acids.--Several methods for the pre-paration of these compounds have been described. The condensationproducts of aromatic aldehydes with diethyl malonate or ethylcyanoacetate yield on reduction and subsequent hydrolysis aryl-methylmalonic acids which give arylpropionic acids on heating :R*CH,* CH( C02H), + Re CH,*CH,*CO,HR*CHO + CH,(CO,Et), + R*CH:C(CO,Et), +Hydroferulic and hydrocaffeic acids have been synthesised in thisway.8Substituted naphthylacetic acids have been prepared by twomethods.The first is an application of a method previously em-ployed for the preparation of substituted phenylacetic acids? and4 A. Eckert and R. Pollak, Monulsh., 1917, 38, 11 ; A., i, 345.SOC. Chem. Ind., Basle, Brit. Pat., 18081 of 1915; from J . SOC. Gliern.G. T. Morgan, Brit. Pat., 102834; from J . SOC. Chem. Ind., 1917, 36,Ind., 1917, 36, 129;207 ; A . , i, 197.A . , i, 197.7 J. Thomas, T., 1917, 111, 562; A . , i , 451.A. Lapworth and F. H. Wykes, ibid., 790 ; A., i, 572.9 F. Mauthner, Annulen, 1909, 370, 368; A., 1910, i, 11594 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.has been used for substituted a-naphthylacetic acids only. Forinstance, a-naphthaldehyde is condensed with hippuric acid, givingan azlactone, which, on hydrolysis with sodium hydroxide, yields 811a-napht.hylpyruvic acid, from which a-naphthylacetic acid isC,,H7*CH0 + FH,*NK*COPh ~CO,Hobtained by oxidation.1° The second method has been applied to thepreparation of both a- and P-naphthylacetic acids; these are ob-tained in yields of 40 to 50 per cent.of the theoretical by a seriesof reactions which may be represented as follows 11 :R*Ne --+ R*CH,Br + R*CH,.CN + R*CH,*CO,H.Halogenob emenes with Mobile Halogen.It is well known that mobility is conferred on the halogen of ahalogenobenzea e by two nitro-groups in the oo- or oppositions, andprevious work has shown that one of the nitro-groups may be re-placed by other groups, such as the cyano- o r benzoyl groups, with-o u t preventing the mobility of the halogen.Further study in thisfield is now recorded, and the test of activity employed is the reac-tion with ethyl sodiomalonate and ethyl sodioacetoacetate inethereal suspension. It is shown that one nitro-group alone is notsufficient to render a halogen atom mobile, as, for instance, ino-bromonitrobenzene. Of the compuunds formulated below, onlyCN CN CVMe(1.1 (11.1 (111.)COXe COPh COPh(IV.) (V. 1 (VI. 1those numbered (I) to (V) reacted with ethyl sodiomalonate, andonly (I) and (111) with ethyl sodioacetoacetate. These facts confirmthe previous observation that a nitro-group has a greater influencelo F. Mauthner, J . pr. Chem., 1917, [ii], 95, 55 ; A., i, 337.l1 F.Mayer and T. Oppenheimer, Ber., 1916, 49, 2137 ; A., 1916, i, 8160 RG h N 1 C C H EM IS'IXY. 95on tlie mobility of an ortho- than of a para-'halogen atom, andit was also found that the cyano-group has a greater effect in confer-ring mobility than the acetyl residue, whilst both are far superiort o the benzoyl residue.12Whilst, however, the mobility of the halogen in the ortho-halogenobenzophenone (VI) was insufficient to answer the parti-cular test employed, yet the benzoyl group alone confers consider-able mobility on a halogen atom in the ortho-position, for 2-bromo-henzophenone, like benzophenone itself, gives benzhydrol whentreated with alcoholic potassium hydroxide, the bromine atom beingdisplaced by hydrogen, whereas the 3- and 4-bromobenzophenonesyield 3- and 4-bromobenzhydrols. The fact that 2-bromobenzhydrolis itself stable t o alcoholic potassium hydroxide shows that tlieelimination of bromine precedes the reduction of the ketone, andth2 mobility of the halogen is due, therefore, to the proximity cfthe benzoyl substituent .13Alkyl Ethers of Polyhydric Phenols.The orientating influence of the alkyloxy-groups in catecholethers has been the subject of several papers.14 The first substituentinvariably takes up a para-position, so that in the case of veratroleonly 4-nitro- and 4-bromo-veratrole are obtained.Further treat-ment then yields a 4 : 5-disubstituted derivative in nearly everycase, but an exception is found in the action of bromine on 4-nitro-veratrole, which yields 6-bromo-4-nitroveratrole.M7ith derivativesof veratrole in which a first substituent occupies the ortho-positionwith respect to a methoxy-group, the orientation of a second sub-stituent is generajly influenced by the polarity of the first substitu-ent in the sense that when this is positive i t enhances, and whennegative counteracts , the influence of the iiei g hb ou r i ng met h oxy-group. Thus, on nitration, 3-acetylaminoveratrole gives 5-nitro-3-aminoveratrole, but o-veratraldehyde gives 6-nitro-o-veratralde-hyde :OMe OMe OMel2 W. Borsche, L. Stackrnann, and J. Makaroff-Semljariski, Ber., 1916, 49,13 P. J. Montagne, ibid., 2243 ; A., i, 35.l4 C. S. Gibson, J. L. Simonsen, and M. G. Rau, T., 1917, 111, 69 ;2222 ; A., i, 15..4.,i , 203 ; J.L. Simonsen and M. G. Rau, ibid., 220 ; A . , i, 336 ; T. G. H. Jonesand R. Robinson, ibid., 903; A., i, 69096 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.An e'xception to this generalisation is found in the behaviour ofo-veratric acid, which yields 5-nitro-2 : 3-dimethoxybenzoic acid onnitration :OMeI n the preparation of 3 : 4 : 5-derivatives from 4 : 5-disubstitutedcatecliol sthers, the new substituent enters the ortho-position withrespect to the inore negative of the groups occupying the positions4 and 5 unless one of these groups is powerfully ortho-directive.Thus :NO2 NO2MeO/)NO, --t MeO'\NO,. MeO/'Br MeO/ \BrMeO!., Br ' Med lMe Med,,)Me \,' M~O(, B~ \/Two further observatiom in this field may be mentioned. Thereduction of compounds coiitaining the methylenedioxy-group isknown to lead in certain instances t o one 15 or both l6 of the possibleinonophenols :It is now found 17 that 4-nitrocatechol methylene ether (I) yields5-nitroguaiacol (11) on treatment with sodium metlzoxide in methyl-alcoholic solution :(1.) (11.1 (111.)This is not, however, a case of reduction, but of hydrolysis, forthe use of sodium ethoxide in ethyl-alcoholic solutions gives a quan-titative yield of 5-nitro-2-ethoxyphenol (111).The second discovery 18 is that halogens, like the nitroxyl group,can replace aldehydo- and carboxyl groups in catechol ethers.Thuspiperonylic acid (IV) is converted by the action of bromine in(IV.) (V-)15 G. Ciamician and P. Silber, Ber., 1890, 23, 1162 ; A., 1890, 965.16 F.L. Pyman and F. G. P. Remfry, T., 1912, 101, 1595.l7 Mrs. G. M. Robinson and R. Robinson,ibid., 1917, 111, 929; A . , i, 692,Is Jones and Robinson, Zoc. cit. ; compare also Miss A. M. B. Orr, R.Robinson, and Miss M. 31. Williams, T., 1917, 111, 946 ; A., i, 703ORGANIC CHEMISTKY. 97aqueous sodium carbonate into 4 : 5-dibromocatecliol rnethyleneether (V), wliicli gives a characteristic colour reaction, and maytherefore prove useful in the investigation of acids obtained by thedegradation of natural products. The question of the displacementof one group by another-not necessarily in the case of alkyloxy-clerivatives-has recently been reviewed in connexion with a studyof the displacement of sulphonic acid groups in aminosulphonicacids by halogen atoms.lg It may be noted here t h a t many phenolicethers call lie deinetliylated by melting them with aniline hydro-c hl or i d e .?‘)Two discoveries of general importance in coniiexioii with desmo-tropic compounds are reported, namely, the influence of soft glassoti the melting points of the solid compounds, and the formation o fa (1 d i t ive com p o u n d s with a 1 coli o 1 s .The keto-form of dibenzoylacetylmethane, CHBz,*CO*CH3, waspreviously believed to exist in two forms, nieltiiig a t 107-110’’and 1 4 9 O respectively, the second form being obtained from the firstby heating with acetyl chloride.It is now 21 found t h a t the sub-stance which has not come into contact with alkali melts a t 150°in Jena-glass tubes and a t 107-110° in soft glass tubes.Afterwashing with dilute sodium acetate, however, it melts a t the lowertemperature even in Jena-glass tubes ; the depression of the meltingpoint in soft glass tubes is therefore due t o the alkali of the glass.The fact t h a t after heating with acetyl chloride the substance meltsa t 150° even in soft glass tubes is explained by the presence in thereagent of chlorides of phosphorus, which leave on evaporatioritraces of non-volatile acids sufficient t o overcome the alkalinity ofthe glass. The substance melting a t 107-110° therefore owes itslow nielting point to rapid enolisation in the presence of alkali, andis not a distinct variety; consequently, there is no need for thehypothesis put forward by Michael 22 t o explain the existence of twostereoisomeric keto-forms of dibenzoylacetylmethaneEarlier observations of the melting points of the enolic form ofthis coinpound and of the ketonic and enolic form of tribensoyl-methane are corrected in the light of this discovery, and i t isshown23 in a similar manlier t h a t Michael’s &form of ethyl forniyl-l 9 J.J. Sudborough and J. V. Lakhunialani, T., 1917, 111, 41 ; A . ,* O A. Klemenc, BeT., 1916, 49, 1371 ; A . , 1916, i, 820.21 W. Dieckmann, ibid., 2203 ; A . , 1916, i, 822.22 AN^. Report, 1912, 124.23 W. Dieckmann, Ber., 1916, 49, 2213; A . , 1916, i , 820.REP.--T’OL XIV. Ei, 12898 ANNUAL REPORTS ON THE PIZ0G:RESS OF CHEMIS'I'ItY.plienylacetate, whicli Wislicenus 24 regarded as a mixture of tliea- and y-forms, is the y-forin coiitaiiiin,ztetl wit81i traces of alkali.Further light has been thrown on tlie constit,iition of' t h e formyl-pheiiylacetates by studies of the inetliyl ester.25 This occurs iii twocrystalline forms, t h e a-form nieltiiig a t 40-41O and tlie &forma t 91-93O.Both are apparently enolic, since they combine withbremine readily and completely, and show no difference in theirbehaviour to dilute alkali. I n other respects they differ, t h e a-formreacting more readily with ferric chloride, copper acetate, ant1plienylcarbimide, whilst the P-form more readily restores tlie coloiirt o magenta decolorised by sulphurous acid ; t h e P-form gives noini~iiecliate coloiir reaction with ferric chloride.A solutioii of t h e P-form in methyl alcohol yields a crystallineadditive product, C,,H,,O, + MeOH, after keeping for a short tinit?and then cooliiig with ice and salt, whilst tlie same additive coin-pound can be isolated from t h e methyl-alcoholic solution of t8hea-form only after keeping for a much longer time. It thereforeappears tliat only the P-form is capable of combining with methylalcohol, and t h a t the formation of the additive product from thea-form is preceded by isomerisation of the a- t o t h e /3-form.Theadditive product does not give a coloration with ferric chloride; i tis unstable and readily parts with methyl alcohol, leaving a liqiii(1wliicli gives a deep coloration with ferric cliloride and eventuallytleposits t h e crystalline a-form.The ascertained facts have been very fully discussed, but no com-pletely satisfactory interpretation can be given.It is consideredmost probable tliat t h e a- and &forms are cis-t7nr,s-isoii.lerides, a dt h a t tlie difference in behaviour towards ferric cliloride may beexplained by the steric arrangement which permits the formationof co-ordination compounds with the vis-forin only :H OH\/CI'C/\C,H, C0,Mea-Estel..The formation ofH O\/\ c Fe</[ i c othe methyl alcoholHO H\/ c&/\C6H5 C'0,Bfe&Ester.additive product and itsprobable condition in niethyl-alcoholic solution a r e represented forthe time being by the following scheme:A . , 1915, i, 241.W.l3icckmanii, Rer., LnlS, 50, 1.375; A . . 1918, i . 15.24 Ann. Report, 1912, 125 ; see A. Michael, Annulen, 1914, 4.06, 137;25 W. Wislirenus and collaborators, ibir?.. 1916, 413, 206; A . , i, 2fiS ORGAN I C CH EM 1 S'I'R 1'. 99CH*oH CHO C'H*OHI -+ CPhi +- tCO,Mc! C0,MeProceeding slowly. Pi*oreeding inow rapidly. On evaporrltion.1Jut it remains to be seen whether or not this view will be niodi-Geti when more facts collie t o light and are fully considered. Ac-cording to a preliminary aiiiioiiiicenieilt,~, methyl oxalacetate,wliicli is enolic in the solid state but mainly iioii-eiiolic in alcoholicsolution, also forms an additive compound with methyl alcohol ;this cannot) be represented iii the same way as the additive corn-p n n d with methyl fol.niylplienylacetate, a n d yet it would appearthat, the two cwes are coinparable.It may be noted that the exist-ence of alcoholates of the forniylplieiiylacetates, which was SIIS-pectetl earlier,27 and has now been established, invalidates manyprevious explanations of the bellaviour of these and other desnio-tropic compounds in alcoholic solution.Whilst ethyl oxalacetate has hitherto been isolated iii oiily onesolid modification (the eiiolic), it has been found possible to preparen substituted derivative of which both the enolic and ketonic modi-ficat ions are st able.28 This is tlietliyl a-oxalo-P~-diplieiiyli~ropj 311 ate,aiul here the keto-form is the more stable of the two:-+ --3 I IUHPh + RLOH CHPh UPh thIeOHf- 1 +- jC'0,ACe C0,MeQO C0,E t ~(OH)*CO,l(:tPh,CH*CH* CO,F,t Ph,C H*C*CO,EtOther compounds which have been isolated in desmotropic formsare formyl~iaplitl~ylacetic esters,29 prepared by the condensation ofa- and P-naphthylacetic esters with ethyl formate, and ethyl 0- and~)-bro~iiocyaiioplieiiylpyruvates, which exist in colourless ketonicand coloured eiiolic forms, to which the following forinul~e areattributed :CcH,Br*CH( CN)*CO*CO,R C,H,Br*C(CN):C(OH)*CO,R.C'olo ur N u d C o ~ i s t i t I! t ion.I n recent papers 31 the coloured additive compounds of quinonesand phenols (quinhydrones) and those of aromatic nitro-componnds2 6 W.Wislicenus and K. Eble. Ber., 1917, 50, 250 ; A . , i, -371.2 7 A. Michrt~4, Annnlen, 1912, 391, 275 ; A .. 1912, i. 801 ; W. Dicckmrtnn.2 R Wislicenus and Ehle, Eoc. c i t .2 9 W. Wislicenus and H. Elvert, Ber., 1916, 49, 2520; A . , i , 202.30 S. Opolski, L. Czaporowski, and J. Zacharski, ihid., 2283 ; A . , i , 29.31 P. Pfeiffer, Anwalen, 1914, 404, 1 ; 1916, 412, 253; A., 1914, i , 551 ;Ber., 1916, 49, 2213: A . , 1916, i , 820.1917, i , 205; J . J. Sudborongh. T., 1916, 109, 1339; A . , i , 84.E 100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.with aromatic compounds generally, are brought into line with thecoloured coinpounds of ketones with inorganic acids and salts, thecolour of which is ascribed by Pfeiffer to halochromy.32 Conipoundsof the type of quinhydrones can be obtained from quinones aiiclhexamethylbenzene, and consequently do not depend on tlie pres-ence of phenolic hydroxyl groups, but rather on an attachmentbetween the carbonyl group and the unsaturated hydrocarbonnucleus, which may be represented as follows :CGHG.. . O:C,H,:O . . . CeH,.The function of the amino- and phenolic 1iydroxyI substitiients ofthe benzenoid component of quinhydrones is coiisidered to be auxo-chromic. Lifschitz, who was previously 33 unable t o acceptPfeiffer’s views on the constitution of the quinliydrones 011 account-of his experiences in the spectrocheniical examination of benzo-quinhydrone, now 31 finds that this inem%er is not representativeoi the class, and accepts Pfeiff er’s representation. The compoundsuf s-trinitrobenzene and aromatic compounds are probably of aeimilar type to tlie quinhydrones, their formation being due toattachment between t 11 e u 11 saturated nitro -gr ou p a lid the ii iisa t u r -ated hydrocarbon nucleus, R-NO, .. . C,H,. The so-calledI‘ picrates ” of aromatic hydrocarbons are merely a special case ofthis type of compound. Confirmation of t’he above view of the con-stitution of these compounds is afforded by examination of tlieadditive compounds of s-trinitrobenzene.35 In these, the number ofmolecules of the nitro-compound with which one molecule of theammatic compound can combine, does not vary with the number ofamino-, substituted amino-, hydroxyl, or alkyloxyl groups present,but rather with the number of aromatic nuclei, the additive com-pound containing in most cases one molecule of the nitro-coln-pound for each aromatic nucleus.111 this comexion, a condensedsystem of benzene and heterocyclic rings, such as naphthalene andquinoline, has to be regarded as a single nucleus, but compoundssuch as s-diplienylethane and diphenylamine combine with twomolecules of the nitro-compound by virtue of their two separatenuclei .H. Ley36 has attempted to correlate the degree of unsaturationof certain compounds with their colour. H e finds t h a t the absorp-t,ioii spectrum of stilbene is modified by the introduction of a methylgroup in the a-position in the direction of the saturated compounddibenzyl. Moreover, stilbene gives a deeper yellow fusion with32 Compare Ann. Report, 1916, 109.33 I. Lifschitz and F. W. Jenner, Rer., 1915, 48, 1730; A ., 1916, i, 4.5,34 I. Lifschitz, ibid., 1916, 49, 2060; A , , 1916, i , 823.S 5 Sudhorough, loc. cit. 3 4 Ibid., 1917, 50, 243; A , , i , 2ClORGANIC CHEMISTRY. 101s-triiiitroheiizene than a-inetliyl- or a-phenyl-stilbene, wliicli indi-cates that stilbene is tlie iiiost unsaturated of the three compounds,according to Werner’s rule that, the more unsaturat.ec1 the hydro-carbon, the more deeply coloured is the inolecular compound.H. Ka~ffmaiin,~7 conimenting on this paper, points out inaiiydifficulties, and holds t h a t whilst unsaturated character is a factoriti tlie formation of cliromopliores, it is by no means tlie factorwhich determines tlie degree of chromophoric activity. I n con-trast to Ley’s results, lie finds t h a t substitution of an a-liydrogeiiatom of 2 : 5-diniethoxystilbene by carboxyl or cyano-groups, whichtire known to increase tlie degree of saturation of the double link-ing, actually causes an increase in tlie colour of the compouiid :(nfeO),C,~I,* CH :CHPh (MeO),C,H,*CH: CPli*CO,R(&!eO),C,H,* C‘H:CPh(CN).Deep greenish.yellow.White. Pale greeilisli-yellowIn aiiotlier paper, H.Kauffmann38 gives an accouiit of certaiiieliromoplioric groups wliicli have also auxochromic f uiictioiis. Ifoiie considers compounds of the type I and I1 (where Clir. is tlie(1. ) (11.)clironiophoric group), i t is seen that (I) contains tlie strongly auxo-cliroinic g r o u p NMe,, which has no chromophoric properties, andconsequently behaves normally towards the chromophoric group intlie p-psitio:i without regard to any auxochromic function of tlielatter; in (11), however, the question as to whether tlie chromo-yhoric group has auxochromic properties is all-important.If it114s not, there is no reason why a compound of this type slioulcl bemore deeply coloured than the parent compound, C,H,*Chr, as, f o riiistaiice, pdinitrobenzene and nitrobenzene, b u t if the chronio-plioric groups have auxoc’liroinic functions, each acts on tlie otherin the usual way, the effect being to produce a deeper colour thant h a t of the compound C,H,-Chr. In a case where the styryl radicleis the chromophoric group, p-dimethylaminostilbene,NMe,* C,H,*CH: CHPh ,is white, whilst p-distyrylbenzene, PhCH:CH*C,H,*CH:CHPh, isyellow.The socliuiii and potassium salts of ethyl o- arid pnitroplienyl-acet’ate have been isolated 39; they are all deeply coloured, andpresumably have the quinoiioid formula,EtO*CO*CH :C’,H,:NO,Na (K),s 7 Ibid., 630 ; A ., i , 391. 3a 16id., 516 ; A . , i, 394.39 8. Opolski and T. Zwislocki, ibid., 1916, 49, 1606 ; A . , 1916, i, 81102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.like tile salts of p-iiitroplienylacetouitrile.~(J Coloured salts a ~ i desters of o- and rn-nitrophenylacetoiiitrile have also been prepared 41; these are of interest in conliexion with the question of theexistence of meta-quinonoids, for the ortho-, meta-, and para-com-pouiids are so similar t h a t if the ortho- and para-compounds areto be regarded as quinonoids, so also must the meta-compounds.C/?irurrioiso//(e,,i.s~ri.-In contiiiuatioii of earlier work,@ Pfeiffer 43has published a second paper on the chromoisomerism of the iiitro-inethoxystilbenes, in which it is recorded that only those coni-pounds containing the methoxyl group in the para-positioii yieldcliromoisomeric salts.2-Nitro-4’-methoxystilbene-4-carboxylic acidoccurs iii a yellow aiid au orange form. These give orange aiiclyellow pyridiiie salts respectively, from which the original varietiesof the acid can be recovered by treatment with hydrochloric acid.The orange pyridiiie salt, however, passes into the yellow salt wheiitreated with excess of pyridine, so that it is possible to pass fro111the yellow to the orange acid through the pyridiiie salts, whilstthe reverse change can he brought about by heating the orangeacid.The two forms of the acid are oiily capable of existeiice iiithe solid form, so that the phenomenon would appear t o be that ofpolymorphism were it not for the fact that each caii be convertedinto the other, as explaiiietl above. Elucidation of the coiistitu-tioii of such chromoisoinerides will require further work, and inthe meantiine Pfeiffer regards the subject as beiiig on the borderline between polymorphism and chemical isomerism, aiid terms itH. Kauffnianii 44 has prepared two coiripounds, ethyl a-cyaiio-2 : 5-diinethoxyciiinaillate (I) and phenyl cyano-2 : 5-cliiiiethoxy-styryl ketone (11), each of which occurs in two foriiis, which differcryptoisomerism.’OMe OMe OR99(1.) (11.) (111.)iiot oiily in colour but also i n the iiiteusity ; i i i ( I colour of theirfluorexeiice. A possible ex1)laiiatioii that tlie plienonieiioii is due4 0 Ann. Report, 1916, 110iz Ann.Reporf, 1916, 108.23 Rer., 1916, 49, 3126 ; A . , i, 140.S. Opolski, Z . Kowalski, and J. Pilewski, Ber., 1316, 49, 2 2 7 6 , d., i, 25,Is I b i d . , 1324 ; d., 1916, i, 817ORGANIC CHEJf 18'L'RY. 103to cis-fraiis-isoiiierisiii is negatived by the fact t h a t t! : klinietliosy-benzylidenenialononitrile (111) behaves similarly. Another ex-planation must therefore be sought, and i t is suggested t h a t themolecule undergoes changes in internal state other than actualalteration in constitution. The author's views are eiiuiiciated asthe Principle of Variable States, for further particulars of whichthe origiiial paper should be consulted.11'11 c 1'11 11 !/ e i i t l J r i ti ci p l r s o f C: / 11 !/The results of three independent iiivestigal ions 4,; 011 the puiigciitpriiiciples of ginger, which have been carried out iii this country,the United States of America, aiid Japan respectively, have beenpublished almost siniultaneously .The inost iniportant is that ofLapworth aiid his collaborators, the other two papers coveriiig oulypart of the ground explored by these authors, The earlier workof Thresh aiid of Gariiett aiid Grier had showii t h a t the puiigentprinciples were coiitaiiietl in a viscous oleo-resin, * ' gingerol," fromwhich 110 crystalline derivatives wei*e obtained.Wlieii this sub-stance is iiiethylatetl bj7 iiiethyl sulphate and alkali, i t yielcls ;iiiiixture of ail oil with R crystrtlline coinpouiid. terniecl iiietliyl-giiigerol (Nelhoii, L a p ~ o r t h ) , which is obt ;tined ill varying amountaccording to the purity of the ' ' giiigerol," the hest yiclcl l~eing60 per cent. RiIetliylgiiigerol is decomposed I)y the actioii of heator boiling aqueous alkalis wit 11 the forniatioii of l~iet2iyl~iiigcro11c,C',,H1603, and aliphatic alclehytles, chiefly ii-~ie~,laltleliyclc. IZ'lietimethylziiigeroiie is oxidisetl hy iiieaiis of aqu~wus w r l i i i i i i hypo-hromite, i t yields P-3 : 4-diii~etlioxypheiiyl~~ro~~iotiic acid (1) a i i ( 1lironioforni, which iiiclicat es t h a t it is 3 : 4-rli11~ctho>;y~~lie1iyletliyliiietliyl ketone (11).This view wax confirmet1 by the syiitliesis ofthe ketone by reduction of veratrylideiieacetoiie ( N o I ~ ~ L w ~ , Lap-worth).The constitution of methylgiiigerol is iiot quite clear, IJut thecutl\po~~iicl is p r o l ~ ~ b l y it11 alrlol-coiiclciisatioii lJro(1 uct of 11 liel't -r 5 E. K. Xelsvn, J . -4,rier. C'12eiti. A'oc., 1917, 39, 1466 ; A . , i , 572 ;H. Xomuw, T . , 1917, I l l , 769 ; A , i , 570; -1. Lapworth, Jlrs. L. K.Pearcjoii, aid F'. .I. Rujle, hid., 77'7 ; A . , i , 571 ; A. Lapworth and14'. €1. IVylies, i!Jid., 7'30 ; L4., i, 372104 ANNUAL REPOR‘I’S ON THE PROGRESS OF CHEMISTRY.aldehyde aiid its lower homologues with metthylzingerone, and iiiaybe represented as follows (Lapworth) :CH,*CH,*CO*CH,*CH(OH)*[CH,],,*CH,/\The oleoresin “giiigerol ” siinilarly gave a iiiixture of fattyaldehydes, chiefly ti-heptaldehyde, and a phenolic ketone,zingerone, CllHl4O3, when heated alone or with acids or alkalis.Zingerone gave methylzingeroiie on inelhylat ion, a i d therefore hadoiie of the forniulz (I) or (11).CH,* CH,* COBle CH,*CH,*COMe/\ /\\/ \/ I ]OHOMe1 loR.IeOH(1.) ( J I .)I t s identity with the substance of forniula (I) was establishedsynthetically iii two ways : (1) by reduction of vanillylideneacetone(Nomura), and (2) by reduction and hydrolysis of ethyl vanillyl-ideneacetoacetate (Lapworth).CH:CH*COMe c1 H 2* C H ,* C 0 Me CH:C A C* CO,Et/A /\ /\\/ I JOMe --+ I 1 0 ~ e \/ \/ + I lo&OH OH OHSo far as the question of the groupings essential to the pungencyof gingerol, zingerone, and similar coinpounds has heeii investi-gated, it appears to be certain that the presence of a free phenolichydroxyl group is necessary, and also probably that of a ketoniccarbonyl group suitably disposed in a saturated chaiii attached t othe phenolic residue.“ Paradol,” the pungeiil principle of graiiis of paradise( A wio??~utiz Me/eguetcc), behaves like ‘‘ gingerol ” on methylation,giving a mixture of a crystalline substance with an oil, and, it isinteresting to note, the crystalline compound has proved to beidentical with niethylgingerol (Nelsoii).Sy 17 t h ese c of A‘ CI t I ( i*crl Ph e 11 ol i c li e t on e 8.K.Hoesch’s method 46 for the preparation of phenolic ketoneshas been successfully applied to the syntheses of niaclurin and4 6 Ant&.Report, 1915, 970KC)ANlC CHEMlSTHY. 105phloretin. Rfaclurin is obtained by tfhe condensation ofpro t oca t echuon it r ile with phl or og 1 u ci n 01,47 it Y for mu1 a t ion as2 . 4 : 6 : 3’ : 4 ’ - l ~ e n t a h v ~ l l . o x 3 . b e n z o ~ ~ i ~ ~ ~ ~ ~ ~ ~ (I) being thereby con-CO OH OH(1.1 (11.)firmed, whilst phloretin (11) results from t’he conclenqation of1111 1 ore t on i t r i I e (P-p-hyd r ox y pheii y 1 pro pi o 11 it r i le ) ph 1 or n -glucinol.4*For the preparation of the nitriles of hydroxybenzoic acids,which are required as starting materials in these condensations,several methods are available.Protocatechuoiiitrile was first pre-pared froin piperonylonitrile by E ~ i n s , ~ g using Barger’s methodfor the hydrolysis of methylene ethers.50 It may also be obtainedby treating protocatechualdoxime with acetic anhydride, when thediacetyl derivative of protocatechuonitrile is obtained, from whichthe dihydroxy-nitrile can be prepared by careful hydrolysis.51(HO),C,H,*CH:N*OH + (AcO),C,H3*CN + (HO),C,H,*CN.Phloretonitrile was made by a third iiiethod ; phloretamide wasacetylated to protect the phenolic hydroxyl group, aitd the acetylderivative was then dehydrated with phosphoryl chloride, yieldingacetylphloretonitrile, from which the acetyl group was removed bymild hydrolysis.‘)?A c 0 C’,; 13,- C H ., * c‘ H CO N 11, + A c 0 C,H4 C H,* CH C N +wit hHO*C,H,-CH,*CH,*CNEtliylcne Orrides.The properties of a group of complex ethylene oxides, obtainedby the action of sodium ethoxide on o-halogenoacetophenones i l lthe presence of an aromatic aldehyde,C HBr0 ’ Ar°CO*CH,Br t Ar*CHO + Ar*CO*CH< Ihave been studied, most completely in the case of anisoylphenyl-ethylene oxide, lMeO*C,H,*CO*CH <gHph, which is obtained from4 7 K.Hoesch and T. von Zarzecki, Be?.., 1917, 5Q, 4G2, G G O ; A . , i, 342.48 E. Fisclier end 0. Nouri, ibid., 011 ; A , , i, 303.4 9 T., 1900, 95, 1488.50 Compare A i i ? ~ . Repoyt, 1916, 104.Hoescli mid von Zarzecki, Zoc. c i t . Fischer and Nouri, loc. cit.E106 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.w -chloro-pmethoxyacetophenone and benzaldehyde 53 By theaddition of the elements of hydrogen chloride, under different con-ditions,* i t forms two chlorohydrina,MeO*C,H, *CO CHCl CH (0H)Ph MeO*C,H,-CO*CH (OH).CHClPh.(1.1 (IT.)the constitutions of which follow from the results of treatmentwith sodium ethoxide, when (I) is reconverted into the ethyleneoxide, whilst (11) yields anisyl benzyl diketone.When anisoylphenylethylene oxide combines with hydroxyl-amiiie under varying conditions, it yields three isomeric com-pounds, all of which lose a molecular proportion of water and, when give 5-phenyl-3-anisylisooxazole,boiled with acetic acid containing a little concentrated sulphuricacid. Of the three isomerides, two, namely (Iu) and (IIu), canbe prepared from the chlorohydrins (I) and (11) respectively, andthese are formulated as derivatives of 4 : 5-dihydroisooxazole.MeO*C,H,* CH: YPhN--- 0NeO*C,H,* 8 *CH,*(JOH)Ph PIIe0*C6H4* 9 ‘C H(OH)*yHPhN-- 0 N------ 0(Ia.) ( IIn.)The third isomeride, which appears to be the normal oxime,IMeO°C6H,*c(:NOH)*CH<~HP”, is transformed by a trace ofmineral acid into the compound (IIcc).Anisoylphenylethylene oxide can be converted by careful treat-ment with alcoholic sodium hydroxide into the isomeric compoiind,anisyl o-hydroxystyryl ketone, OMe*C,H,*CO*C(OH):CHPh, theenolic form of anisyl benzyl diketone, but prolonged treatment withalkalis results in the formation of a-hydroxy-fl-phenyl-a-anisyl-propionic acid, MeO*C,H,*C(OH)(CH,Ph)*CO,H, through t h ebenzil transformation of the diketone first formed.Phthaleins.The quantitative decomposition of phenolphthaleinoxime intoo-4-hydroxybenzoylbenzoic acid and p-aminophenol by boiling withdilute sulphuric acid can be explained by assigning the formula(I) to the oxime, and assuming t h a t it undergoes the Beckmann63 0.Widman, Ber., 1916, 49, 477, 2778; A . , 1916, i, 406; 1917, i, 221;H. Jbrlander, ibid., 2782 ; 1917, 50, 406 ; A . , i , 222, 343 ; S. Bodforss, ibid.,3916,49, 2795 ; A., i , 223ORGANIC CHEMISTRY. 107rearrangement, giving the substance (11), which then suffershydrolysis, 64 o-4-Hydroxybenzoylbenzoic acid is converted quanti-tatively into phenolphthalein by heating with phenol, and maywell be an intermediate product in the formation of this substancefrom phenol and phthalic anhydride.It also condenses with otherphenols t o form niixed phthaleius, as, for iiistance, with a-naphtholt o form a-naphtholphenolphthalein,739CTro c ,lj c li c C' o n z po ID e r i i w f i ~ r s of cycloPropr/e.-The action of different reagentson cyrlnpropane derivatives of the following general formula,where R is hydrogen or an alkyl group, and A r is aii aromaticds il ?i d T e r pe I i o s .(2) (3)A rCH-CH*COArresidue, has been found to result in fission of the cyclopropanenucleus in the three possible ways.55 On reduction with nascenthydrogen, the ring is opened between the 1- and 3-carbon atoms,giving substances of the formula (I), whilst alkalis bring aboutfissioii between the 2- and 2-carbon atoms, yielding substances ofArSE*CH2*COA r ArCH:$!-COArCH(CO2R >2 CH(C*,R),(1) (11.1the formula (11).The addition of hydrogen bromide proceeds intwo ways, the ring opening between the 1- and 2-, and also between5 4 W. R. Orndorff and Miss R . R. Murrfig, J . Arne?.. Chem. Soc., 1917, 39,5 5 E. P. Kohler and J. R. Conant, i b i d . , 1404. 1699; A . , i , 566, 568 ;679; A . , i, 339.E. P. Rohler, G. A . Hill, and I,. A. Bigelow, i b i d . , 2405.E* 108 ASNUAI, REPORTS ON THE PROGHESS OF CHEMISTRY.the 2- aiid 3-carbon atoms, yielding the bromo-acids (111) and (IV).which are very readily transformed into lactonic acids.ArCH Rr*$!H*CO *A r ArCH Br*C(C10,R)2*CH,*COA rCH(CO,R),(TII.) (IV.)nrrt'/wf i PPS of cyclonri i ' o ~ ~ P.-Condensation of dialkylacet one-tlicarboxylates (I) by meaiis of sulphi1ric acid leads to clialkyl-cyclobutane-1 : 3-dionecarboxylates (IT), which readily suffer fissioii+ EtO*CO*CHMe*yO E t 0.CO *$?Me 70CO-CHRLe EtO*CO.CH Rle(1.1 (IT.)when boiler1 with water, or when treated with hydrazine, hytlroxyl-a in i 11 e , or a 11 i 1 i 11 e , y i el tl i 11 g d e ri vat i ves of d i a1 k y 1 ace t o 11 ed i c a r 1)-oxylates.Treatineiit of ~ialkylc~rlobutaiiedioncca~boxylates with alkylhaloids ant1 sodium ethoxide in alcoholic solution leads-presiun-ably through unstable tl.ialkylc!/clobutanedioiiecarboxylates (ITI)-to t rialkylacetoiiedicarboxylates (IV). When heated with(111.) (IV.)aqueous baryta, the dialkylc.ycl,,butaiiedionecar'uoxylates yieldclialkylc!/c7obutaiie-l : 3-diones, R*CH<:g> CHR.These differin many important respects from dimeric ketenes, which caiiiiottherefore be derivatives of c,yclobutaiie-l : 3-cliones, as was believedprevio.usly.56X n 11 t IL ogcr 1/07, ri I ) r 1- i iw t i 1 P of c y cl ope 11 t e / t e . -X a 11 t hog allol wasdiscovered by Stenhouse,~7 who prepared i t by the action of bromineand water on tribromopyrogallol, and assigned to i t the formulaC,8H,06Br14. This empirical formula was confirmed later byTheurer,5* who proposed for the substance a structural formulainvolving three reduced benzene rings connected by oxygen atoms.Recently, the substance and its reactions have been thoroughlyinvestigated by F. J. Moore and Miss R.M. Thoinas,59 who haveshown, by analysis, that xanthogallol contains no hydrogen, aiidhas the formula Cj0.,Br4, confirmed by determiiiatioii of the mole-cular weight. They consider i t to be a cyclopentene derivative5 6 G. Schroeter, Rer., 1916, 49, 2697; A , , i, 145.s 7 Journ. Chem. SOC., 1876. 28, 1.5 4 .4nn~Zeiz., 1855, 245, 327 ; A . , 1888, 1084.59 J . Antel.. Chein. SOC., 1917, 39, 974 ; A . , i, 460ORGANIC CHEMISTRY. 109(111), aud iuterpret its formation from tribroiuopyrogallol (I)tlirough tetrabromocyclohexenetrione (11) as follows :Br CBrC BrC;Br ~ U I * ~co-co(111.)fl\This formula satisfactorily explains the fact that xaiithogallolforms a quiiioxaliiie derivative, and yields on treatment withsodium hydroxide a conipouiid, xaiithotoilic acid (IV or V), whichis converted smoothly by bromine water into peiitabroiiioacetoiieaiid oxalic acid.C *OH C*OHYBr CHBr, or CHBr YBr,CO*CO,H H0,C-CO(IV.) (IT*)/\ /\ -+ CBr,*CO*CHBr, + (CO,H),Y'he Syrhthesis of Priicltorie.-L. IiiiziCl~~ 60 has effected the coin-plete synthesis of ?*-feiichone, and thus confirmed Semmler's formulafor this ketone.Ethyl l-methylc.yc/opentan-4-one-l-carboxylate(I) was condensed with ethyl bromoacetate, aiid water waseliminated froin the resulting compound (11), giving ethyl dehydro-C H,*CMe*CO,Et CH,*CN e*CO,EtI I + i CH, -+I CH2I 1 CH2I UH,*b(OH)*CH,*CO,EtCH,*CO(1.1 (11.)CH, CMe*CO,E t CK,*CMe*C02EtCH,*C: C H* CO,EtI I -+ I CH, + I I 1CH,* b H CH,* CO,E t(111.) (IV.)CH2*CMe*C0 CH,*CMe*CO CH,*CMe*COI h H 2 1 + 1 uH, I + I C'H, Ic H b H --u H M~ C'H,*GH- C M ,(V.1 (Vl.) (VLI.)I 1I I Ic' H , * C H--U A1 0,I 16 o B e y . , 1917, 50, 1362; A , 1918, i, 22110 ANKUAL EtEPOlt'l'S ON THE PROGRESS OF CHEMISTRY.methylnorhoniocainphorate (111). By reduction, ethyl inethylnor-homocamphorate (IV) was formed, the lead salt of which gavernethylnorcamphor (V) on distillation. This was treated twicewith methyl iodide and sodarnide, when a mixture of fenchosaiiten-one (VI) and feiichone (VII) resulted.propose an altera-tion in the nomenclature of fenchenes. They employ the termsa- and P-fenchenes, using the former for the substance which yieldsthe hydroxyf enchenic acid and fenchocamphorone of higher inelt-iiig point.Wallach's UZ-fenchene is therefore Z-a-fenchene, and hishd-fenchene is d-P-fenchene. They have completed the synthesisof r-a-fenchene (111) 62 by preparing it from 9.-a-fenchocamphorone(I), which had been synthesised previo~isly,~~ and find t h a tI--a-fenchene is identical with isopinene. The synthesis was effectedby the action of magnesium methyl iodide on ~.-a-feiichocainphoroiieand distillation of the resulting alcohol (11) under atmosphericpressure, when water was eliminated.CH,*CH-CH, CH,*CH-OH, CH,*CH-OH,Fetichenes.-G. Komppa and R. H. RoschierIII &Me, I I I CMe,, ' I , UMe, I +CH,*CH---CMe*OH CH,-~'H-C:CH-,ICH,&H-CO(1.1 (11.) (111.)It has been proposedG4 that terpenes which retain the originalfenchane ring system, and thus differ from the fenchenes, shall becalled fenchylenes; a fenchylene (IV) has been prepared by theCH*CMe*CMe,d is t i 1 la t i on of met h y 1 is o f e n ch y 1 x a n t h a t e .Salz tene.-The hydrocarbon obtained by the removal of hydrogenchloride from camphenilyl chloride was previously termedcamphenilene. It now proves to be a mixture, and can also beprepared by the dehydration of camphenilol (I) by sodium hydrogensulphate a t 200O.The main constituent of the mixture is a hydro-carbon identical with santene (111), and it is proposed to retain(il , h a d . ScL Fenizicne, 1915, [ A ] , 7, 1 ; A . , i, 398.6 2 G. Koinppa and R. H. Roschier, ibid., 1916, [ A ] , 10, 3 ; A . , i , 466.64 S. S. Nametkin and Mlle.A. K. Rushenceva, J . Buss. Phys. Chem. SOC.Ann. Report, 1914, 120.1916, 48, 450 ; A . , i, 152OltGAXlC CHEMISTRY. 111the term camphenilene for the constituent (11) present iii smallercl u a n t i t y .'jjCH,*CH--Clllle, CH,*CH--CMe, CH2*CH--CMeCH,*C= =CH CH,* CH--Cr/LeI II-+ I ?HZ I aiid CH, I I +H2 I CH,*CH--CH*OIF(111. )The complete synthesis of santeiie has now been effected, forcamphenilone, from which campheiiilol is obtaiiied, was synthesisetlpreviously.66Cholesterol.A . Windause7 has now achieved by chemical ineaiis a reactioiiwhich hitherto has been effected only in the living organism,namely, the reduction of cholesterol to coprosterol. Whilst thehydrogenation of cholesterol in the presence of platinum yieldsB-cholestanol,GE the use of nickel a t 200° gives rise to a new pro-duct, y-cholestanol, which has the same melting point and specificrotatory power as fbcholestanol, b u t differs from i t in crystallisingfrom dilute alcohol without water of crystallisation.y-Cholestanolhas proved to be an additive compound (partial racemate) ofB-cholestanol (about 50 per cent.), $-coprosterol (ikholestanol),and s-cholestanol. The @-variety was removed by precipitation withdigitonin, b u t the other two could not be separated directly.Advantage was therefore taken of the fact t h a t on boiling withamyl alcohol and sodium amyloxide, s-cholestanol is converted intoB-cholestanol to the extent of about 90 per cent., whilst $-coprosterolis only converted into coprosterol to the extent of about 10 percent.After treatment of the mixture of s-cholestanol and$-coproster01 in this way, the B-cholestanol and coprosterol wereremoved by precipitation with digitonin, when the filtrate con-tained $-coprosterol contaminated with only a small amount ofs-cholestanol, and after a repetition of the treatment the first wasobtained practically free from its isomerides. Finally, theq-coprosterol was converted into the equilibrium-mixture contain-ing about 20 per cent. of coprosterol by the action of sodiumethoxide a t 1 8 0 O . The mixture was treated with digitonin, when6 6 G. Komppa and S. V. Hintikka, Bull. SOC. chim., 1017, [iv], 21, 13 ;66 G. Komppa and S. V. Hintikka, Ber., 1914, 47, 1550; -4., 1914,13' Ibid., 1916, 49, 1724; -4., 1916, i , 513.6 8 Consult Ann.Report, 1916, 119, for the relations between the reduction.4., i, 214.i , 852.products of cholesterol, and for their partial formulz112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the coinpound of digitonin and coprosterol separated, from whichcoprosterol was recovered by extraction with boiliiig xylerie.It appeared recently (i3 that Windaus had modified his partialforinula for cholesterol, the foriiiula (I) beiiig replaced by (11).CHAIe,*CH 2*CH,*C11H,7CH C H/\/\/\\/\/CH,CH CH,/\/\CH,CH CHRlob H , AH, 6 H hH26H 6 HHO*CH CH(1.1 (11.)The reasoils for this iiiodificatioii have since been published,TrIand are as follows. The keto-carboxylic acid obtained by theoxidation of cholestenoiie was previously believed to have theformula C,,H,,O,, and to be formed in accordance with theequation below :C,,H3,*CH:CH2 C2,H,;CO,H/\CH,*CO+50= /\ + CO, + H,O.CH,~COA large number of analyses have now shown that, it, containstwo more atoms of hydrogen, and should be formulated C,,H,,O,.It cannot therefore be formed from cholestenone by the oxidationof a vinyl group, and is now represented as resulting from thefission of an unsaturated ring, in the following manner :.____~ C22Hm\/I I'22*39I I 1C22H39\/\/ICH2 &H 6H + 40 = CH, CH CO,H = CH2 C'H, bO,HCO\/\CO C0,H CO CH+ co,.Support for the new foririula is found in the previously knownfact t h a t the unsaturated nitro-cholesterol can be converted readilyinto a keto-alcohol, cholestanonol, in which the keto-group is con-tained in a fully hydrogenised ring.This reaction is now repre-sented as follows:I AH, dH &H + AH2 AH b * N 0 2 --+ b H , dH (20\/\/HO-CH CH,\/\/HO*CH CH\/',/HO*CH CHG 9 dtm. Reporl, lglti, 119.' 0 A, Windaus, Ber., 1917, 50, 133; d., i, 265ORGANIC CHEMISTRY. 113A z oxy-co t r i p u rzds .-The unsynim etrical for mu la tioii of azoxy-benzene as PhNO:NPhil is supported by the hehaviour of azoxy-veratrole (I) aiid azoxypiperoiial (111) 011 nitration, for whilstcoiiipouiids coiitaiiiiiig two veratrole nuclei syiiiiiietrically placed,for ex ample, diver a t r y 1111 e t h a ii e a ii d a z over a t ro le , ct o ii o t y i e IdInolionitro-derivatives, but give synirrietrical dinitro-derivatives as -first products, azoxyveratrole yields a inononitro-derivativewhilst azoxypiperoiial gives a ii uiisym met rical iii trocarboxylic(IV) .72--+\/(1.1 (11.)UV.1In the case of o-hydroxyazoxybeiizeiie, which has Ioiig beenknown t o occur i n two foriiis. the siiiiple explaiiation that theseare to be formulated as (V) aiicl (VI) is iiot coiiipletely satisfactory.It does iiot explain why oiie form is readily soluble iii tlilutcHO*C,H,*N: IS OPh HO*C,H,*NO: NYI1alkalis, is easily oxidised by alkaliiie periiianganate, aiitl dyes silkaiid wool, whilst the other ( i s o ) form lacks these properties.0.Baudischis iiow suggests that whilst the iiiore active form hasthe formula (V), the i.so-fQrm may be represeiited by the formula(V.) (VI.)An azoxy-compound has beeii obtaiiied by the oxidation ofphenylazocarbonamide with hydrogen peroxide,PhN:N*C'O*NH, -+ I'hNO:N*CO*NH,.Arari.Report, 1916, 122.i r Mrs. G. M. Robinson, T., 1917, 111, 109; A . , i, 226.73 Eer., 1017, 50, 333 j A . , i, 356114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYHot aqueous acids or alkalis deconipose it, with the production oftphe transforiiiation products of diazobenzeiie.74L)iutzoyl~ei~oZs.-The iiature of the anhydrides foriiied by thediazotisatioii of amiiiopheiiolsulphonic acids has recently beeniiivestigated.’S 011 diazotisatioii, 0- and paminophenols givecoloured diazo-oxides, whilst ainiiiosulphoiiic acids give colourlessanhydrides, such as the well-known “ diazobeiizeiiesulphoiiic acid, *’and there are therefore two possible alternatives for the course ofthe reaction with amiiiopheiiolsulphonic acids.Three such acidswere diazotised, namely, o-aiiiinophei:ol-4-sulphonic acid (I),11-aniinophenol-2-sulphonic acid (II), aiid 712-aminophenol-4-sulphoiiic acid (111).OH OH OHS0,H(1.1 (11. ) (In.)The first gave a yellow anhydride, aiid the colour of its aqueoussolution was not appreciably altered by the addition of aqueousalkalis, whence it appears t h a t the free anhydride aiid its alkalisalts have the same chemical coiistitutioii ; this anhydride is there-fore an o-diazo-oxide or o-quinonediazide.76001‘\/SO,H( K)\/SO,H(K)~~-An~i1iopheiiol-3-sulyhonic acid gives a colourless tliazo-deriv-ative, which forms yellow alkali salts.The colour chaiige indicatesa change in constitution from internal diazonium-sulphonate top-diazo-oxide or pdiazoquinone.OH ,---0 0I 1()SO,K .N=N\//\i4 A. -hgeli, Atti Id. dccatl. Liricei, 1917, [v], 26, i, 95, 207 ; -4., i, 528,75 G . T. Morgan R I ~ C ~ H. P. Toniljns, Z’., 1917, 111, 497 ; -4., i , 481.7 @ For previous work on the comparative merits of the possible alternative417.formulae of internal diazo-oxides, uee Ann. Report, 1915, 114ORGANIC CHEMISTRY. 115The diazo-derivative of ~~~-aminoyhei~o1-4-sulphoiiic acid is a colour-less internal diazouiuin-sulphonate, and on treatment with alkalidecoiiiposes and shows no tendency to form a meta-diazo-oxide-atype of conipouiid which does not appear to exist.An advance has also been made in the investigation of theallied diazoimides by the preparation of the hitherto inaccessibleacyl derivatives of 11-diazoiminobeiizene, by diazotisiiig acyl-11-~,heiiyleaediamiiies with liquid nitrous anhydride iii dry acetoiie.77---N CORFissio/r of fiytZ?wzi~ies.-A study of the properties of o-ainino-P-benzylphenylhydrazine has led H.Franzen and B. von Fiirst 78t o express views on the mode of decomposition of substitutedhydrazobenzenes. By heating a t 120-1 30°, o-amino-P-benzyl-pheiiylhydrazine ( I ) is converted into benzaldehyde-o-aminophenyl-hydrazone (111), benzylamine, and o-phenylenediamine. Thisreaction is explained by the assuniptioii that the hydrazine is firstdissociated into two unsaturated residues, which are then reduced/\NH, I INH*NH*CH,Ph ')NH2 I + PhCH,*NH-" (I.) \/NH-by a second molecule of the hydrazine.This thereby becomesosidised to an azo-coinpound (11), which suffers rearrangement tothe isomeric benzaldehyde-o-aminophenylhydrazone. The whole/\NH, I lNH*N:CHPh(111.) m*c,,,,, \/ (I*.) ' \/course of the decomposition is similar to the spontaneous changeof hydrazobenzene into a mixture of azobenzene and aniline, whichthe authors interpret in the same way,2PhNHeNHPh + 2PhNH - + PkiNH*NHPh +ZPhNH, + PhN:NPh,holding, contrary to the view of Wieland,i9 t h a t there is no reasoilwhy diphenylhydrazines should not be supposed to dissociate intofree radicles, as do the tetraphenylhydrazines.7 7 G.T. Morgan and A. W. H. Upton, T'., 1917, 111, 157; A . , i, 300.Annalen, 1916, 412, 14 ; A . , i, 58.7 9 Ann. Report, 1915, 113116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Wheii u-amino-B-benzylphenylhydrazine is heated with dilutehydrochloric acid, it uiidergoes a series of transforrnatious, whichare best explained by the assuniptioii that, hydrogen chloride isadded a t the N-N liiikiiig with the forniatioii of o-phenylenedi-aiiiiiie aiid )Jeiizylchloroainiiie, and it is pointed out that a siiiiilarassuniptioii in t'he case of substituted hydrazobeiizeiies affords ailexplaiiatioii of the formatioii of azo- and ainiiio-coiiipounds, andof the benzidiiie arid semidiiie transforiuatioiis.1. PhNHONHPh + HCl + PhNH, + PhNHCI.2.(a) PhNHCI + PhNH*NHPh --+ PhNH,,HCl t PhN:NPh.+PhNH, --+(4 PhNHCl + PhNH, --+ PhNH*C,H,*NH,...I rcto.ritltct i o i ~ of ~~'!/~l/.tr,.o/ies.--The autoxidation of benzaldehyde-p h en y 1 hydra zoxi e i ii a 1 co h ol i c s ol u t i o ii yields a coin plic a t ed m is t u r eof products from which diphenyldibenzylideiiehydrotetrazone,PhCH:N*NPh*NPh*N:CHPh, benzaldehyde, and benzoic acid werepreviously iso1ated.BO A more detailed examination 81 of the courseof the reaction and the components of the product has giveniiiteresting results. If the autoxidation is carried out in indifferentsolvents, such as hydrocarbons, benzaldehydepheiiylhydrazone per-oxide can be isolated. This substance is uiistable, and is readilyconverted into benzoylpheiiylhydrazine and beiizoylazobenzene.PhSH*r*NHPh --t PhCO*NH*NHPh + PhCO*N:NPh0---0When the autoxidation takes place in alcoholic solution, the per-oxide caiiiiot be isolated, but benzoylphenylhydrazine and com-pounds presumably derived from benzoylazobenzene are found.Thus, the formation of benzoyldipheiiylbeiizylidenehydrotetrazoiie* O H.Stobbe aid K. Xowak, Ber., 1913, 46, 2'887 ; 3., 1913, i, 1200.81 31. Buach and W. Dietz, ibid., 1914,47, 3377 ; A . , 1915, i, 307 ; M. Buschand H. Kunder, ibid., 1916, 49, 2345 ; A . , i, 56ORGANIC CHEMISTRY. 117may be explained by the addition of benzoylazobenzen~ to theunchanged hydrazone.PhCO*N:NPh + PliNH*N:CHPh +PhCO *KH NPh* NPh N :C' HPh .An other constituent o f t h e m i x t u r e , b en zo y 1 p he n y 1 hydra z i n o b e n z-aldehydepheiiylhydrazone, PhCO*NH-NPh*CPh:N*NHPh, igderived from this hydrotetrazone, froni which it may be preparedby keeping in alcoholic acetic acid solution.Other substancesisolated were benzeneazodiphenylmethane and its isomerisntionproduct,, benzopheiioiiepheiiylhydra~one,NPh:N*CHPh, + NHPh*N:CPh,,besides the three compounds which had been identified previoiidy.Z I I f )-N / I / olpc ~ I I N ~ G I ) N n y e .--Sirnu1 t aiieous oxict a t ion an tl reductionwithin the molecule bring about the conversion of substitiit)e(ln-nitroinandelic acids into derivatives of 2 : 2'-axobenzoic acid :b 0 2 H C02H /I .)N====3 \) ; ~ ~ o H ) * C o P + ) p H +/ *This reaction, which was first observed on heating 6-nitro-3 : 4-methylenedioxyinandelic acid with nitrobenzene,@ can also bebrought about by the action of hot aqueous alkali hydroxides onthe acid, b u t in this case about a quarter of the acid is convertedin to the azoxy-compound .@3 Other subst it uted o-nit romandel icacids undergo the same change-for instance, 6-nitro-3 : 4-dimeth-oxymandelic acid N and 6-chloro-2-iiitroiiiaiidelic acid .85 The trans-formation resembles that effected by the action of hot aqueousalkalis on derivatives of 1)-nitrotoluene, when azoxystilbenes areformed, together with nitroso- and azo-stilbenes.86A 171 I ) / n I ) i I ( C o / I ! 110 I I ) I (1s .-The p re pa 1' at ion of ani ni o ii i u in con 1 -pounds of a new type has been continued. and other examples maybe added to t h a t of triphenylmethyltetramethylammoniu~n,CPh,*NMe, .h7 Instances are beiizylte~ramethylanimoniuni,PhCH,*NMe,,x2 Mrs.G . &I. Robinson and l i . Robinson, T., 1914. 105, 1466: 1915,R3 Bfrs. G. 11. Rohinson, illid., 1917, 111, 109 ; A . , i , 226.84 Mrs. G. hl. Robinson and R. Robinson, loc. cit.R 5 S . Reich and W. Rlerki, Bull. SOC. chim., 1917, [iv], 21, 8 ; A . , i, 3.37.R 6 F. Bender and G. Schultz, Ber., 1886, 19, 3334; A . , 1887, 205 :A n x Report, 1916, 111 ; W. Rchlenk a n d J. Holtz, Ber., 1917, 50,107, 1763; .4., 1916, i , 166.P. Karrer, ibid., 1915, 48, 305 ; A . , 1916, i, 333.262, 274, 27G ; A . , i, 255, 263118 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and di-p-tolylaminotetraniethylanimoi~iuni, (C7H7),N*NMe,, whichare obtained by the action of tetramethylammonium chloride onsod iu m be nz y 1 a 11 d pot a ssi o- d i - p- t o I y 1 a mi 11 e respect i ve 1 y .Sod i u mbenzyl is itself new, and is obtained by the action of sodium onmercury dibenzyl. It is a red, crystalline compound which inflamesin the air. It is ionised in ethereal solution; thi.; indicates t h a tthe metallic atom is linked by a carbonium valeiice, as in the caseof sodium triphenylmethyl, which it resembles closely.0 rgn n o-nz e t cdlic Compounds./,eat?.-The synthesis of lead tetra-alkyls containing fourdifferent primary alkyl groups has now been achieved. Mixedlead tetra-alkyls, containing only primary alkyl groups, whentreated with halogens a t - 7 5 O , yield lead trialkyl haloids withthe loss of one alkyl group, which is invariably the smallest ofthose present.Thus, lead trimethylethyl yields lead dimethylethylhaloids, which on treatment with magnesium n-propyl haloids givelead dimethylethyl-n-propyl. By a similar series of operations, thisis converted successively into lead methylethyl-n-propyl haloid andfinally into lead methylethyl-n-propyl-n-butyl.**Lead tetra-alkyls containing secondary alkyl groups, however,behave differently, the secondary alkyl groups being less firmlyattached to the lead atom than the primary radicles. Thus, leadtetraisopropyl loses two alkyl groups when treated with halogena t - 75O, giving lead diisopropyl dihaloids, and lead diethyldiiso-propyl yields lead diethyl dihaloids.@ I n the case of the leadtetra-primary-alkyls, treatment with halogen a t a higher tempera-ture, -ZOO, is necessary to remove two alkyl groups, and the leaddialkyl dihaloids so formed are then stable towards halogen a t theordinary temperature.g0 When these dihaloids are treated withmagnesium alkyl haloids, mixed lead tetra-alkyls of the typePbR,R’, are obtained ; thus, lead tetramethyl can be convertedthrough lead dimethyl dichloride into lead dimethyldiethyl.91Another method of preparing the same compound is as follows:lead tetraphenyl yields with bromine lead diphenyl dibromide,from which lead diphenyldiethyl is obtained by Grignard’s reac-tion; on treatment with hydrogen bromide, this yields lead diethyldibromide, which reacts with magnesium methyl iodide to givelead dimethyldiethyl.92 Halogen hydrides can also be employed8 8 Q.Griittner and E. Krause, Ber., 1917, 50, 202 ; .4., i, 256.8* Ibid., 674; A., i , 384.s o Ibid., 1916, 49, 1415; A . , 1916, i , 799.91 Ihid., 1546; A . , 1916, i, 800.92 9. Mijller and P. Pfeiffer, ibid., 2441 ; A , , i, 122ORGANIC CHEMIS’rRY. 119to prepare lead trialkyl haloids from lead teti-a-alkyls, and the leadtrialkpl haloids when treated with silver hydroxide in aqueou3solution give alkaline solution3 of lead trialkyl hydroxideu, fromwhich other salts may be p~epared by ~ieutralisation with acids.83FRANK LEE PYMAN.PART III.-HETEROCYCLIC DIVISION.A FEW words of explanation are necessary in order to define thescope of this section of the Reports.Year by year, with the dura-tion of the war, the regular circulation of foreign journals hasbeen more and more interrupted until, in the past eighteen months,i t has been difficult to procure any recent Continental periodicalswithin a reasonable time after their publication. Thus some ofthe journals for 1916 did not come to hand until the present year.and when it became necessary t o draw up this Report, i t wasfound that. several important papers had escaped notice in the1916 volume, to which they properly belonged. In these circum-stances, it seemed best to include them in the present Report ratherthan allow them t o pass without reference. The Reporter is awaret h a t this decision to some extent oversteps the limits set him, buthe believes t h a t the reader’s judgment in the matter will coincidewith his own.The section headings of the Report give an idea of its contents,so it is scarcely necessary to expatiate on the various subjectsin this place.Mention, however, may be made of the new synthesisof tropinone and also of the iiiiportant paper on the naturalsynthesis of alkaloids. Hitherto, it has been assumed by Guareschiand Pictet that alkaloids are formed in the plant as a result, ofdegradation, and not by direct synthesis from simpler compounds ;b u t Robinson has now indicated methods whereby t h e directsynthesis might be attained in simple ways, and it appears, fromhis own synthesis of tropinone, t h a t these methods are not merelytheoretical, but may be achieved in practice.N e i r Heferocpclic Types.Last year, mention was made of some new heterocyclic rings inwhich elements hitherto unknown in t h a t guise played their partsg3 P.Pfeiffer, P. Truskier, and P. Disselkamp, Rer , 1916, 49, 2446 ; A . ,i, 129120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.as members of the cyclic system.' Further details are now avail-able with regard to some lead clerivativeu.2By t,he interaction of lead diethyl dichloride and the magnesiumcompound of as-dibromopentnne, diethylryc7opentamethylene-pliimbine has been isolated :This substance, when treated with bromine, yields lead diethyl-c-bromoamyl bromide, a compound which appears to react abnorm-ally, since with magnesium ethyl bromide it yields lead diethyl-E-bromoamyl, the reactive halogen atom being left unaffected int h e end-product.The cyclic lead compound also is abnormal, in that it is oxidisedin the air, and it is suggested that this variation from the usualstability of tetra-alkyl lead derivatives should be ascribed to thetension in the ring.The argument may be sound, but there seemsno reason why a six-membered ring should n o t be reasonablystable, if one may judge from analogy to carbon compounds.Possibly some other factor lies a t the root of the matter.Soz oiodol-Mercwy Compounds ,The majority of the organic compounds of mercury which areemployed in pharmacy may be divided into two classes. I n thefirst group lie those substances which contain mercury in theionisable form, such as mercury salts of organic acids; whilst, thesecond set comprises compounds in which the mercury is not inan ionisable condition, but is attached directly t o the organicnucleus.It is found that some of these compounds are insolublein water, but are capable of being dissolved by a solution of sodiumchloride. There is no great, difficulty in accounting for this pheno-menon in the case of the two classes just mentioned. I n the caseof the organic salts of mercury, double decomposition is assumedto take place between the mercury salt and the sodium chloride,with the formation of a sodium salt and mercuric chloride, whichthen dissolve in the water present. With regard t o the substancescontaining organically combined mercury, i t is assumed that.theyform sodium salts of chloromercuri-aromatic acids by the additionof sodium chloride, and that these new compounds are soluble inwater.Ann. Report. 1916, 131.C:. Griittiicr and E. I<rause, Bev., 1910, 49, 2666 ; A , , i, 122ORG A NI C CHEM I STRE’, 121An iiispectioii of the formula of sozoiodol-iiiercury,shows t h a t it belongs to neither of the classes already nientioiietl.It is not a mercury salt of the ordinary type, iior is its mercuryatom held to the nucleus by linking it with a carbon atoni. Nonethe less, it is soluble in a solution of sodiuiii chloride.Sozoiodol-mercury is prepared 3 (1) by the actioii of yellowiiiercuric oxide on sozoiodolic acid (2 : 6-di-iodopheiiolsulphoiiicacid) ; (2) by the interaction of mercuric nitrate and sotliuiiisozoiodolate; or (3) by adding a warm aqueous solution of sodiuiiisozoiodolate to an equivalent amount of mercuric acetate solution.When a solution of sozoiodol-mercury in aqueous solution is ex-tracted with ether, mercuric chloride is removed in a proportioilwhich indicates t h a t the following equation probably representsthe interaction between sozoiodol-mercury and sodium chloride :C,H,I,<-O->Hg + 2NaCl= HgC1, + Na9*C, K,T2*S0,Na.so3It appears, therefore, t h a t sozoiodol-mercury behaves aiialogouslyt o ordinary organic salts of mercury.It con-taiiis only two chromophoric groups in the ordinary seiise--theiodine atoms-although the benzene ring might also be regardedas a possible third.Fromthe results given in the paper under review, i t appears possiblethat the group *O*Hg*O* possesses a chromophoric character,A second problem is suggested by sozoiodol-mercury.None the less, i t is orange in colour.(:!/ cl ic SN I p JL id es .A coniplete group of sulphides has been exaiiiiiieti coiit a iiiiiigfour-, five-, six-, and seven-membered rings, one ~neiiiber of eachring being a sulphur atom . 4 The compounds were syiitliesised bythe action of sodium sulphide on t,he appropriate dihalogeii cleriv-ative of a paraffin, wherein the two halogen atoms are attachedto opposite ends of the chain. Iii most cases, the product containsa mixture of substances, namely, the uiiimolecular sulphide, a poly-inerised sulphide, and a third product, which is probably adihalogenated thio-ether. I n the case of the four-inenil)erecl ring,the yield is small.All these sulphides behave l j ke open-chain sulphides on oxida-tion, sulphones being formed on oxidising them with permanganate.E.Rupp and A. Herrmann, Arch. Pharm., 1916, 254, 4 8 8 ; A . , i , 516.E. Grischkevitsch-Trochimovski, J . Russ. Phys. Choti. SOC., 1916, 48,880, 901, 928, 944, 951,7959 ;: A . , i, 163-158122 ANNUAL REPORTS ON THE PROGRESS OF CHEMIISTRY.With iiiethyl iodide, triiiietliyleiie sulphide foims a peculiar iiieth-iodide having the composition C3H,jS,2MeI, in which both theiodiiie atoms are precipitable with silver nitrate. The six- aiidseven-membered sulphides f orin the ordinary type of additive pro-duct, having one iiiolecule of iiiethyl iodide attached t o the sulphide.All the sulphides unite with niercuric chloride, giving coinpouiidsof the type R,HgC'l,, where R represents oiie iiiolecule of thes ul 11 hide.As R class, the iiew sulphitles are colourless, mobile liquids withuiipleasaiit odour ; they distil uiiclecoiiiposetl, are iiisoluble iii water,but soluble iii ordinary organic solvents.Cheiiiically , they a reakin to the aliphatic thio-ethers. They do iiot react with beiizoylchloride, alkalis, or sodiuiii. With broiiiiiie, they foriii very 1.111-st able add it i ve coin pounds.Owing to the fact that diethyleiie disulphide rnethiodide sliowsit certain parallelism with the iiiethiodides of tertiary cyclic iinines,i t was thought that analogous results of exhaustive methylatioiimight be expected iii the case of the rriethiodides of the iiew cyclicsul phi d es ,but it was foutid that there are esccptioiis t o the geiicrnlreaction.When heated with pot assiuiii hydroxide solutioii,2 -111 e t h y I tetra h y d rot h i o p h e 11 111 e t h i o( 1 i d e be haves i ii a cc o i- cl a ii ce wit 11aiiticipatioii, yierdiiig ail open-chain sulphide :I 4HO*CH A f e*CH; CZ'I,*CH,*SMe1CHBle: CH CH,*CH,*S*EUIeSimilar treatnieiit of pciitaliiethyleiie sulpliitle iiictliioclicle, how-ever, aimply results in the regei1eratiolt of the parent p i i t a -rnethylene sulphide, no opening of the ring taking place. On theother ha ii d , 2 -111 e t h y 1 pe ri t a m e t 11 y 1 m e P u 1 pli i d e 111 e t h io tl ide g i v ecl a iiopen-chaiii sulphide in the iiormrtl manlierORGANIC CHEMISTRY.123\\’it11 regard to physical properties, the iiew sulplrides showabnormality in their refractive indices. If the refraction constantfor the sulphur atom is calculated by subtracting the iioriiial valuesfor the carbon aiid hydrogen atoins from the total refractivity ofthe molecule, it is fouiid that the figure thus obtained is very closeindeed to the value for sulphur in the thiopheii series, instead ofapproximating, as might be expected, t o the value for sulphur illthe alkyl sulphides. This, coiiibiiied with other abiioriiial proper-ties, suggests that these iiew sulphides will forin an interesting fieldof research; there inust be some reasoii for the approxiiiiatioti ofrefractive power of the sidphur atoms iii the sulphides and thethiopheii series, although i n the one case there is an atoiii incapableof inaiiifestiiig aiiy increase of valeiicy, whilst iii the case of thesulphides the sulphur atoiiis can show quadi-i- aiid eveii sexa-valeiicy .111 the Aiiiiiial Rel’ort for 1914” it was iiieiitioiiecl that theactioii of iiiercuric chloride 011 thiopheli gives rise to both riioiio-ant1 di-iiiercurichloricles.This reaction has now been extended,aiicl proves to be a iiieaiis of preparing other conipoands of interest.\:hen thiopheii ~iiercurichioride i:, t watecl with two iiiolecules ofsodiuiii iodide, the product of tho reaction is fouiid to be mercuryclithieiiyl iu altiiost quantitative yield :W,H,S,HgCl+ 4NaI =- Hg(C,H,S), t 2NaC! + €Ig12,2Nal,Ny sl1l)s.t it lit i tig foi.thio1)herl iiiet.c.ui.ic.hloi.ic!e other iitialogf)lih ( 0111-pouiids, a whole series of mercury derivatives of t hiophen has beenprepared. All these substaiices behave siiiiilarly when treated withinercuric haloids in acetoiie solution, regeiieratiiig the originaltliiopheii ~iiercurihiiloitl derivative. l‘hus the p a r e i ~ t substa iicc’,iricrcury clithienyl, regeiierates tliio1)heii iiiercurichloriclc in accurtl-aiice with the followiiig equatioii :The oiily exception hitherto observed in this series is the sub-stance 2 : 5-dimethylthiophen-3-mercurichloride, which remains uii-changed when ail attempt is inade t o bring it into reaction withsodium iodide.It is suggested that if t’his abiioriiial behaviour ofcoinpotiiids with niercury in the P-posit ioii proves to lje general, i twill furnigh a einiple iiietllocl of distiiiguishiiig the a- alid P-deriv-atives from each other.Y. 1-38.IV. Steinkopf and A i . Bauermeister, .-1rznc1Zcn, 1917, 413, 310 ; A , , i, 30124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.By utilisiiig the iiiteractioii of thiophen niercurichloride ormercury diethienyl with arsenic trichloride, it has been foundpossible to prepare arsenic derivatives of thiophen. Thus whenarsenic trichloride is shaken with powdered mercury dithienyl, amixture of three thiophen arsenic derivatives is obtained : thienyl-chloroarsine, C,H3S*AsCl, ; dithienylchloroarsine, (C,H,S),AsCl ;aiid trithienylarsine, (C,H,S),As.A new and simple method of preparing thieiiyl ketones7 hasbeen worked out, based on Lecher's method of synthesising theaiomatic ketones.Thiophen, mixed with about 2 per cent. byweight of phosphoric oxide, is allowed to react with acetyl chloridea t 98-130°, and the product contains a 52 per cent. yield of%acetothienone. Other acid chlorides give corresponding thiopheiiketones. The reaction is supposed to take place in the followingthree stages when an acid anhydride is used:(1) P,O, + 2Ac,O = 2PO,*OAc.(2) PO,*OAc + C,H,S = C,H3S*COMe + PO,*OH.(3) PO,*OH + P02*OAc = P20, + CH,*CO,H.When an acid chloride is substituted for an anhydride, the firststage is modified into(la) P205 + CH3*COC1= PO,*OAc + PO,c'l,aiid the third stage becomes( 3 ~ ) PO,*OH + P02C1= P,O, + HC1.One special advantage of the reaction in the thiophen series ascompared with the benzene derivatives lies in the fact.t h a t muchlower temperatures are required in the fornier group iii order t ucarry through the process.Among the numerous types of heterocyclic compounds, the deriv-atives of pyrrole appear t o rank high as a class which furnishes astarting point for varied and numerous researches. I n 1914, theproduction of alkylated pyrroles by different methods occupiedinvestigators; in 1915, the centre of interest wap transferred to thepolymerisations of pyrrole compounds ; whilst in the earlier partof 1916 the main line of research tended towards the study of t'heaction of oxidising agents on menibers of the pyrrole group'I JV, Steinkopf, Annaleti, 1917, 413, 343 ; A ., i, 278ORGAN 1 C C: H EM I STR 1’. 1%During the latter part of the year, however, a fresh field was foundin the condensation of pyrrole with various ketones and aldehydes.sFour main products of the condensation of pyrrola with acetonehave been isolated, namely, (1) a crystalliile substance, C‘,,H,N, ;( 2 ) an aiiiorphous substance, C28H3(i0N4 ; (3) a uon-crystalline sub-stance, C25€132N4 ; and (4) a crystalline compouiid, (C28H3jON4)t3.When the condensation is carried out in acetone solution, (1) and (2)are obtained in almost equal proportions. I n alcoholic solution at theordinary temperature, the results are similar, but in hot alcoholicsolution the elid-product is almost entirely the compound (1).Inaqueous solution a t the ordinary temperature, the compound (1)still makes its appearance, but the inain bulk of the product iu thehubstance ( 5 ) . In presence of mineral or common organic acids,the reaction yields compound (1) as before, but, in ar~dition, mn-pmnd (4) makes its appearance.The compound (3) appears to be formed by a simple condensationreaction between four molecules of pyrrole and three molecules ofacetoiie :4C,H,N + 3COMe,= C,,H,N, + 3H20.It, is therefore referred to as the tetrapyrrole-triacetoiie ” deriv-ative. On heating with hydrochloric acid in presence of acetone,it is converted almost entirely into the compound (l), which ist,herefore termed the ‘‘ tetrapyrrole-tetra-acetone ” derivative.Compound (1) is also formed when the compound (4) is heatedwith hydrochloric acid.Compounds (1) and (3) are evidently related t o etioporphorin,since on oxidation they yield maleinimide, whereas etioporphorinitself when oxidised gives a substituted maleinimide.From thevolume of gas evolved when (1) and (3) are treated with magnesiumpropyl iodide, i t has been deduced that the four imino-groups ofthe pyrrole residues are still intact, and the products of this reac-tion show a behaviour similar t o t h a t of carbamic acids. Fromthe production of unsubstituted maleiiiiinide from (1) and (3) byoxidation, i t is safe to argue that, in the coiidensation reaction bywhich they are formed, no attack has been made a t positions 3and 4 of the pyrrole ring.This limits the problem t o condensationa t position 2, and from certain facts observed in connexion withthe distillation of the compound (l), i t has been assumed that (3)has the structure shown below:* V. V. Tschelincev and R. V. Tronov, J . Rvtss. P h p . C‘hem. SIoc., 1910,48, 106; 127, 1197 ; A . , i , 91, 9:$, 41 1 ; Tschelincev, Tronov, and S. CJKarmanov, ibid., 1210 ; A . , i , 412126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.whilst compound (1) is supposed to have the follclwing formulawhich recalIs Kiister's formula for haemin :.-A further serieq of investigations haq been carried out involvingthe condensation of pyrrole with other ketones, the results beingannlogons to those detniletl above.Substitution of formaldehyde for acetone and the use of acidcondensing agents produces a compound which appears to havethe structure (I), and when t)he condensation is carried out in(1.) ( rI.)presence of potassium carbonate, the product is a glycol, 2 : 5-di-methylolpyrrole (II), which, on oxidation, produces pyrrole-2 : 5-tlicarboxylic acid, so that the reaction forms a method of preparingacids of this type.The new method of methylating pyrrolidyl isopropyl alcoholmentioned in last year's Report'o has been extended to other sub-stances, and has been shown to be a general reaction." Thusa-2-pyrrolidylbutyl alcohol when heated with formic acid and 40per cent.formaldehyde solution a t 105-110° in a sealed tube isconvert,ecl into a-l-methyl-2-pyrrolidylbiityl alcohol.Pyridiri P cind Piperidin P .Less attention than usual has been paid to this class during thecurrent year. When the sodium compound of pyridine, C5H,NNa,is treated with moist ether, a mixture of tetrahydropyridyls isforme(l,*Z and from the fact that antoxidation of the mixture yields2 : 2'-dipyridyl and 4 : 4/-dipyridyl, it may be assumed that thetetrahydro-compounds are similarly constituted.In the Annual Report for 1914,'s attention was directed to theV. V. Tschelinccv and R. I T . Maksorov, J . Rzis.9. PAp. Chem. Soc., 191 6,48, 748, 779 ; A . , i , 161-5.l o Aizn. Report, 1916, 141.l 1 K. Hess, C. Uihrig and A.Eichcl, B e y . . 1017, 50. 311 ; A . , i, 351.B. Emmert, ihid., 31 ; A . , i , 221. l 3 P. 146ORGANIC CHEMISTRY. 127use of pyridine a s a solvent and reagent, ant1 the cilrreiit year hashrought to light wine atltlitinnal examples l 4 of its utilivation int h k brflncli of the subject. Thiis when thiocai~baniitle is boiled inpyri(liiie solution, i t is converted into guanidine thiocyanate anda compound which is regardetl as ammonium trithiocarbonate.Similar treatment converts thioaminophenol into cliaminophenylsulphide,ZSH*C,H,*NH, -+ H,S + S(C(;Ha*NHe)2,whilst thioacetanilicle, in pyridine contaminated with water, pro-duces acetanilide and hydrogen sulphicle. I'iperidiile appears t ohave properties similar to those of pyridine in tlie capacity forremoving hydrogen sulphicle from coml~oun~ls,The Znilole G'ro?/li.A study of the absorption spectra of various derivatives ofindigotin has been carried out,13 and it has been found that markedalterations are observed when sulphuric acid is substituted for itsolvent compounded of chloroform and stannic chloride.The colourchanges observed in the indigotin series closely resemble those foundin the case of the halochromic all-unsaturated ketones, which alsochange their tint in presence of acids. In order to account for thooptical data obtained, it is siiggesied that the forniula for indigotinshould be written thus :NH NHC,H,( "..... >C:C( '";. )C,H,.c':0 c.0 + +It must be frankly confessed t h a t a formula of this type suggestsb u t little to the ordinary chemist, and i t seems doubtful whethermuch is gained by the use of such schemes.T n recent times therehas been a good deal of this kind of thing, and many authors seemt o imagine that they have '' explained " the Occurrence of colourmerely by putting a few dotted lines into their forniulz. Even it'we suppose that such partial valencies exist in molecules, their mereoccurrence does not give u s any idea of the origin of colour i n thecompounds represented. The introduction of an arrow and ndotted line into the indigotin formula can scarcely be iegarderi as astep towards the explanatioii of the physical origin of the tint ofthe substance itself. Residual affinity and the occurrence of colouroften can be proved t o co-exist, but unless we get some clear physical31.Rnffo and 0. Ralduzzi, (Tazzettcr, 1917, 47, i , 6 5 ; .4., i , 382.l 5 I. Lifwhitz and H. LonriB, Rev., 1917, 50, 8 9 i ; A . , i, 586128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRI'.idea connecting the two phenomena, progress is likely to be slow.I n many cases, i t looks ae if the art of formula-mongering hadbecome an end in itself, divorced altogether from any idea of thephysical side of the subject.Heller'c has suggested t h a t the various salts of isatin and itsethers and oxiines owe their clifferences of colour mainly to thedifferent mode of attachment of the metallic atoms to the nucleus,and he states that the N-salts are deeper in tint than the O-salts.CIaasz,17 on the other hand, criticises this view adversely.Hebases his objection on the fact that no K- or C-metallic salts areknown in which the metallic atom is not removed by solution inwater; and yet, none the less, isatin gives a blue salt which, owingto its dissolving unchanged in water, can only be an O-salt. Claaszpoints out that isatin gives three O-salts, to which he ascribes thefollowing formulae.The structure (11) corresponds with the red salt of the red isomerideof isatin discovered by Heller 16 (see below) ; formula (111) repre-sents a blue salt, soluble in water, and its enhanced colour leads totlhe quinonoid structure being applied to it. The deep blueiV-sodium salt of isatin changes to red on solution in water, owingt o its conversion into an O-salt.It, would scarcely be safe toascribe the blue tint, solely t o the X-attachment of the metallicatom, since there is a blue O-salt known also, the colour of whichcould not, be accounted for on this basis. Heller has suggested t h a tits structure should be represented by (IV), but Claasz objects t othis on the ground of insufficient chromophores, and proposesinstead the formula (V) wit,h the quinonoid structure :(IV. 1 (V. 1HellerlR has applied his views to the case of the dioxindole sodiumsalts, one of which is violet, whilst the other is colourless. Heascribes this colour change to the tJransformat,ion of the N-salt intothe O-salt, as shown below:1 6 G. Heller, B e y . , 1916, 49, 2767; A , , i, 219.1 7 M. Claasz, ibid., 1917, 50, 511 ; A., i, 413.1* C.Heller and H. Heino, ibid., 1916, 49, 2775 ; A . , i, 220ORQANIC CHEMISTRY. 129AII iiiterestiiig case of isonierisrii has beeii detected in theisatiiis.19 The lactani and lactirn ethers of isatin (correspondingwith the formulze -4 and L? below) have long been known, but isatinitself was found only in one form, the second desmotropic possi-bility not having been realised in practice. This gap in our know-ledge has now been filled by the discovery of an isomeride of isatin,termed isatol, to which the structure C is ascribed.A . B. C.Tsatol is prepared by acting on the N-silver salt of isatin withbenzoyl chloride and benzene, silver chloride being formed andisatol being liberated. It is a red, crystalline substance which isinsoluble in ammonia, whereas isatin is soluble.A Doubly Condensed Tndobe.A new type of derivative of the indole group20 has been obtainedThe stages in by a double application of Lipp's indole synthesis.the process are shown by the formulae below:/\-SBr \/\ I I-","'XH2 NH2I *I\/\ CBr-\/NH NH2/\-/\/\I l l i l l\/\/-\/NH(111).The substance (I) is prepared from uu-dibromo-2 : 2/-dinitrostilbeneby reduction with stannous chloride dissolved in a solution ofhydrogen chloride in glacial acetic acid.The conversion of (I)into (11) takes place by boiling for a shortl time with alcoholicpicric acid, and the second stage of the condensation is attainedby prolonged boiling of (11) with alcoholic potassium hydroxide.The compound (111), for which the name "dindole" is proposed(a contraction of di-indole), is very pale yellow. Condensed nucleiof this t,ype are known in the pyrrole group, but this appears tobe the first example of such a structure in the indoles.l9 G. Heller, Ber., 1916, 49, 2757 ; A ., i, 219.20 P. Ruggli, ibid., 1917, 50, 883 ; A , , i, 586.REP.-VOL, XIV. 130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The Relative Stability of Cyclic Bases in th,e Hofnzann Readion.The Hofmann reaction referred to in the title of this sectionmay perhaps be more easily recognised under the title of '(ex-haustive methylation," and. is used to indicate the reaction bymeans of which an unsaturated tertiary open-chain base is derivedfrom a cyclic quaternary ammonium hydroxide by the eliminationof water.The experiments 21 which have recently been carried outin this field show that' the elimination of water is not a necessarypart of the reaction, as hydroxy-amines are' frequently formed.When various cyclic bases are submitted t o the reaction, and theamount of decomposition in each case is estimated from an ex-amination of the end-products, it is found that t3he stability of thering increases in the following order : tetrahydroisoquinoline,dihydroisoindole, pyrrolidine, piperidine, dihydroindole, and tetra-hydroquinoline.Another reaction which causes fission in these cyclic systems isfound in the application of cyanogen bromide on the molecules inquestJon. Curiously enough, in this case also the order of stabilityis almost exactly the same as that given in the last paragraph.Since the two reactions are so very different from each other, i tis suggested that the stability of the cyclic system in such cases isintimately connected witah the nature of the forces a t work in themolecule as a whole.Criss-cross Addition t o Conjugated Systems.In glacial acetic acid solution, benzaldazine readily takes up twomolecules of cyanic acid, forming 5 : 3/dihydroxy-3 : 5'-diphenyldi-hydro-1 : 2-triazolotriamle :(''CHPh CH/A N 2N--C:*OH\\N (%)N (b)111 + I + C*OH -+ I I I1V'HOG ("N Ill HO*C--N3 NCHPh(4 \\ NCHPhAn examination of the formula will make it clear that the additivereaction has taken place in what may be termed an abnormalmanner.From analogy to other reactions of conjugated doublebonds, it might have been expected that one molecule of cyanicacid would aCtach itself t o the positions 1 and 4 of the benzaldazine2 1 J. von Braun, Ber., 1916, 49, 2629; A., i, 169ORGANIC CHEMISTRY. 131chain, leaving the second molecule to fix itself in positions 2 and 3.Actually what occurs is that one molecule of cyanic acid attackspositions 1 and 3, whilst the other attaches itself a t 2 and 4, aprocess which may conveniently be described as ‘‘ crisscross ” addi-tion.22 Two factors seem to militate against the possibility of thenormal action of the conjugated system in this case. In the firstplace, addition of cyanic acid in the positions 1 and 3 would entailthe formation of a new bond between two carbon atoms, whereasthe actual coarse of the reaction permits the formation of the newring by means of linked carbon and nitrogen, which is a muclimore common additive reaction. Secondly, the actual course of thereaction ends in the production of two five-membered rings, whichare usually marked hy stability, whereas if the addition took placeat the positions 1, 4, and 2, 3 the substance produced would containone six-membered atid one four-rnembered ring, a much less stabletype. It seems probable that these two factors give the key to thisapparently abnormal behaviour of the conjugated system.Thep i n t is of interest, and if there are any new cases of the kinddetected in future it may serve t o throw light on the still veryobscure problem of unsaturation.When the triazolotriazole is dissolved in 10 per cent.aqueouspotassium hydroxide and subjected to steam distillation, part of i tis converted into a compound which appears to have the structure(I); whereas when oxidised with concentrated nitric acid below looi t yields (11):The Constitution of Jieconic Acid.An attempt23 has been made to establish the constitution ofmeconic acid, which has hitherto been regarded as the trihydrateof 3-hydroxy-4-pyrone-2 : 6-dicarboxylic acid :0CO,H R/\G C O,HHC,,C*OHco22 J. R. Bailey and N. H. Moore, J . Amey. Cliem. SOC., 1917, 39, 279 ;*3 TV. Borsche, Ber., 1916, 49, 2538; A . , i, 117.A,, i, 355 ; J. R. Bailey and A. T. McPherson, ibid., 1322 ; A ., i, 587.F 132 ANXUAL REPORTS ON THE PROGRESS OF CKENISTRY.It is now sliowii that 011 retlriction by means of hydrogen iiipre:ence of colloidal palladiuiii i t yields aPyet,etraliydroxypimelicacid, C0,H*CH(OH)*C'H(OH)*CH(OH)*CH~-CH(O13)*C02H. Now0 0H C / \ ~ HHO 8,8 Hco(1.) (11.)when comenic acid (I) and pyromeconic acid (11) are reduced, thepyrone bridge is not broken and the end-products of the reactionsare pentamethylene oxide derivatives. The conclusion is drawnthat meconic acid is not constituted analogously to comenic andpyromeconic acids, and that instead of being a true pyrone deriv-ative i t is really an open-chain compound of tlie following consti-tution : C0,H-C(OH)2*CH(OH)*CO*CH,*C(OH)2-C0,H. Bearingin mind the difference in constitution between the various com-pounds assumed to be analogous, the evidence may be taken f o rwhat i t is worth.The presence of two hydrtoxyl radicles attached toa single carbon atom in the grouping *CH,*C(OH),*CO,H appearsto be scarcely in accordance with experience.7'11 e illeckcciiism of Pseudo-hme Coiidensation .I n conliexion with some reactions of berberine derivatives, a newtheory of the reactions between pseudo-bases and pseudo-acids hasbeen suggested by Mrs. G . M. Robinson and R. Robinson.24 Whena dilute aqueous acetic acid solution of cotarnine is mixed withnitromethane and sodium acetate is added, the product of the reac-tion is anhydrocotarninenitroniethane. Now cotarnine, under theconditions of the experiment may be supposed to contain eitherof the groups (I) and (11), the former being the carbinolamine formwhilst the latter represents an unsaturated ammonium hydroxide.*CH(OH)*NMe* *UH:NMe(OH)*(1).(11. )From a survey of the evidence a t their disposal, the authors coii-dude that (11) represents the reactive form of this part of thecotarnine chain. Originally,25 the suggestion was made that thereactioiis of such substances could best be expressed as a resultof the interactions of ions; but this view is now displaced by thehypothesis of a simple addition. The ionic hypothesis when applied24 Mrs. G. M. Robinson and R. Robinson, T., 1917, 111, 958; A . , i, 706.2s E. Hope and R. Robinson, ibid., 1911, 99, 2119ORQ A N 1 C C H Ell I STK 1‘. 133to the reaction between a pseudo-acid and a pseudo-base, demandedthe assumption of two intxamolecular changes, which are dispeiisedwith in the later suggestion.Applying the addition hypothesis to a general case, the followingscheme results :...._..HL_,It will be seen t h a t on the l e f t we have tlie two reagents couiingwitliiii each other’s reaction-sphere, and t h a t each reagent isassumed t o display certain partial valencies. I n the second phaseof the reaction, a complex is formed which is held together by thepartial valencies. I n the filial stage of the reaction, rupture ofthe original Imnd between H and X OCCUI’S, acconlpanied by theelimination of water. The second and third stages of thecotarnine-nitrometliane reaction mentioned above are shown in thescheme below :I n order t h a t these changes may be clearly understood, i t isnecessary to point out that a further assumption with regard topartial valency is made in those cases where disruption of a mole-cule results froin the reaction.The case of the formation of ammon-ium chloride will make the matter clear. Iu the first place, whena pair of partial valencies is assumed to exist in a molecule, thevalency utilised in forming the partial valencies is supposed t o hederived from the normal valencies of the molecule; and hence thesenormal valencies become1 weakened. Thus hydrogen chloride dis-playing no partial valency would be represented with a full valencybond between the atoms : whilst when the partial valencies arecalled into play, the bond between the atom is weakened and is tlo1-w repwwc”tec1 by a clottecl liiie :H--C1 .. .H . (21.. 134 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.The formation of ammoniuin chloride would therefore be expressedby the following scheme:CH,A final point inust be indicated. When a normal valency isweakened in order to provide two partial valencies, the two partswill have the same polarity, being either positive or negative;whereas when a Zcrteizt valency (such as exists in tervalent nitrogen)gives rise to two partial valencies these will be of opposite signs.Applying this to the scheme given above for the interaction ofiiitromethane and cotarnine, i t will be found that the polarity ofthe partial valencies engaged in the ring-formation (complex-formation) is representable according t o the following arrange-ment :This theory has been applied to other organic reactions, such c?sthe bromination of ketones and the mechanism of diazo-coupling ;but the reader may be left to trace its full development for himselfiil the original paper.A New Synthesis of Tropinoiie.The drawbacks of the classical method of alkaloidal synthesis areapparent t o anyone.Starting, often, with out-of-the-way materialswhich themselves are obtainable only with considerable difficulty(suberone in the Willstatter synthesis of tropine, f o r example) ,the alkaloidal skeleton is built up laboriously by adding group t ogroup and chain to chain untii the structure is complete.In favourof this method i t may be adduced that i t places beyond doubt theconstitution of the finished product; and from this point of viewthe step-by-step mode of synthesis will always retain its value.From two other points of view, however, it is deficient in manycases. It is often expensive, and therefore its products cannot COM-Pete with the natural alkaloid in commerce ; and, further, i t throwslittle light on the inetliods whereby plants carry out their syn-thetic processes which result in the formation of the alkaloid class.Entirely fresh ground has been broken by a novel synthesis oORGANIC CHEMISTRY. 135tropinoae,26 for the new method appears on the one hand capable ofyielding a cheap product, whilst on the other it holds out the hopet h a t we are a t last on the track of natural uynthetic processes.An examination of the formula of tropinone shows t h a t i texhibits a marked symmetry of structure; and if the structure beimagined as disrupted a t the dotted lines, i t becomes evident t h a ti t consists of a succinyl radicle, a methylamine nucleus, and anacetone group :CH,-CH--’--CHNMe COI _..I : “, .. I 1CH,-CH--’-CH,Tropinone.Following this line of thought, succindialdehyde, acetone, andmethylamine were allowed t o interact in aqueous solution for half-an hour, a t the end of which tropinone was found t o be presentill the mixture. As a test for tropinone, the dipiperonylidenederivative was used, which is readily formed when piperonal actson tropinone.Modifications of the above method of synthesis have also beenfound successful.I n one of them ethyl acetonedicarboxylate isscbstituted for acetone; in another, the calcium salt of acetone-dicarboxylic acid is used. By the latter method no less than a42 per cent. yield was obtained of tropinone, calculated on theweight of succindialdehyde employed.J t will be seen t h a t this new method of synthesis opens u p a verywide field owing t o its simplicity and the good return for thematerial employed; and it marks a great advance on the oldermethods of preparation.,4 Theory of A41k.nloidal Synthesis in Plants.The niechaiiisni by means of which certain plants are able t o syn-tliesise the complicated structures of the alkaloidal type hasIiitherto baffled the ingenuity of most chemists.It is self-evidentthat the processes employed in our laboratories are not akin to thoseen1.ployed in the natural formation of the alkaloid class; for theplant is forced to work within a very limited range of temperature,and the reagents a t its disposal can scarcely be assumed to com-pete in variety with those of the investigator. Clearly, then, thenatural processes must be of a simple nature; they must be capableof acting a t the ordinary temperature and they must not demandcomplicated reagents for their work.2 6 R. Robinson, T., 1917, 111, 762’; -4., i, 581136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Robinson27 has put forward a series of suggestions as to themanner in which many of the familiar alkaloidal skeletoiis maybe produced in the course of comparatively simple reactions, andhis paper should be studied by all who are interested in theproblem.Unfortunately, its ingenuity would lose by condensation,so that only the barest outline of i t can be indicated in this place.Examples are given of possible lines of synthesis in the pyrrolidine,piperidine, quinoline, and isoquinoline groups, which gives someidea of the breadth of outlook taken in the paper.The author assumes for the linking of carbon to carbon in thealkaloidal chain only two simple reactions : (1) the aldol condensa-tion, and (2) the similar condensation of the carbinol-amines (con-taining the group *C(OH)*N*) with substances containing the group*kH*CO*. For the production of the carbinol-amines he relies oncombination of a ketone or aldehyde with ammonia or an amine.After the alkaloidal skeleton has been built u p by these methods,it is necessary to assume further reactions : oxidations, reductions,eliminations of water, or methylation by means of formaldehyde.The work of Collie28 on the polyketen class is quoted in support ofcertain steps in the arguments, and itl is suggested that acetone-dicarboxylic acid may be an intermediate compound in the pro-duction of acetone by the photochemical decomposition of citric acidin presence of the catalyst uranium oxide.The following scheme gives an outline of the possible synthesisof tropinone in the plant:Robinsotz’s Suggested Phytoch emicnl Synthesis of Tropinone.NH,*CH,*CH2*CH,*CH(NH2)*C0,H + 3CH,OMethylation 4 and oxidationCHO*CH,*CH,*OHO + 2NH,Me + CO,condensationCH,*CO,HdH,*CO,HcondensationFH2*CH(OH)>NMB CH,*CH(OH) + (40 (extra reagent)CE,*CH-CH*CO,H CH,*CH-CH,CH2*CH-CH, CH,*CH--CH*CO,H27 R .Robinson, T., 1917, 111, 876; A . , i , 664.28 J. N. Collie, ibid., 1893, 63, 320; 1907, 91, 1806.- 2c02 I &Me 60 + I I I kMe b0 - I I ORGANIC CHEMISTRY. 137\I’itlioat exaggeration, i t inay be said that this paper marks anepoch in the consideration of alkaloid syntheses, and i t opens up anew line of thought which may react strongly on the practicalmethods employed f o r the commercial production of compoundsof this class. Coupled with the same author’s synthesis of tropin-one, which was dealt with in the preceding section, i t suggeststhat we are on the edge of developments in the study of the alka-loids which were undreamt of a t the time last year’s Report waspublished.The Morphine Alkaloids.The experimental work in this branch of chemistry has led inreoent years to conflicting results in more than one case, and inconsequence there has been a good deal of confusion as to themorphine structure.A critical survey29 of the whole subject hasnow been published, in which i t is sought to harmonise all theexperimental data and draw up a formula for morphine itselfwhich will agree with the established facts. As a result of thissifting of the material, the following structures are proposed formorphine and thebaine respectively :I i \ /\/OH’MeOMJ\ / I\/’MeMorphine.Thebaine.A point of some interest has been raised in connexion with thephysiological activity of codeine, It will be recalled that in thecase of cocaine substitutes the peculiar physiological activity of thenatural substance is paralleled by the behaviour of certain syn-thetic substances which bear a more or less remote structuralresemblance to the true alkaloid’s constitution. F o r example, the20 F. Faltis, Arch. Pharm., 1917, 255, 85 ; A., i , 411.F138 ANNUAL REPORTS ON THE PROGRESS OF CUEMIWRY.following f ormulz indicate, the kinship in structure between cocaineand eucaine:CH2* CH-CH*CO,Me I NMe CH*OBzCH,*CH-CH,I II I I CH,*i'Me-bH,Cocaine. Eucaine.An attempt has now been made 30 to ascertain whetlier transposi-tions of groups in the morphine nucleus leave the physiologicalcharacter of the compound unaffected; but the results appear topoint to the true codeine structure being necessary in order toproduce the physiological effect.Thus if the basic properties ofthe codeine nitrogen atom is destroyed by any means, the alkaloidloses its physiological activity, and does not regain it even when anew amino-group is introduced into the molecule by attachment t othe aromatic nucleus of the alkaloid. Hence it is not the merepresence of the amino-group which lends codeine its peculiar char-acter; but, in addition, the amino-group must be active and situ-ated in a particular position in the skeleton.Transposition of thecodeine liydroxyl radicle gives analogous results. The new cum-pound has much less physiological activity than codeine. Finally,when a compound is synthesised containing all the characteristicgroups of codeine (a methoxylated benzene ring, a nitrogen ringwith niethylated nitrogen, and an alcohol group), this " pseudo-codeine '' shows no resemblance to true codeine in its physidogicaleftects. From this it may be deduced that the root-factor in thephysiological activity of both codeine and morphine is to be soughtl i l the position of the nitrogen with regard to the bridged hexa-methylene ring.A new relatioii has been established between thebaine andcodeine by the discovery that when the former is oxidised undercertain conditions it yields a hydroxylic ketone, the oxime of whichis identical with that derived from brornocodeinone.slThree new methyl derivatives of morphine have been prepared,so that the seven possible ones are all now known.g2The UmC Acid Group.For some time this region of the subject has been almost dor-mant; but an enormous flood of new material has recently been3 O J.von Rrauii a.nd K. Kinder, Ber., 1916, 49, 2656; A . , i, 103.31 M. Freund and E. Speyer, J. p r . Chem., 1910, [ii], 94, 135; A., i, 217.32 C. Mannich, Arch. Pharin., 1916, 2!X, 349 ; A., i, 473OltGANIC CHEMISTRY. 139published, which serves to throw a certain amount of light onsoine minor points. It is quite inipossible to suminarise the papers,and attention will therefore be directed oiily to outstaildingsubjects.A series of new reactions of uric acid has been described.3 Amethod of preparing alloxan, suitable for lecture demonstration,is mentioned.34 The formulais suggested for alloxanic acid.35 Some spkohydantoins have beenproduced from certain of the uric acid derivatives.36 A new andsimpler method of preparing 9-methyluric acid is described.37One point of interest has been cleared up in the course of thiswork.It will be remembered that one of the puzzles of the uricacid group was found in the occurrence of three isomeric methyl-uric acids for which only one formula seemed available, since all ofthem were supposed to contain a methyl group in the 3-position.These three compounds were designated respectively : a-methyluricacid, 8-methyluric acid, and j-methyluric acid.It is stated thatb-methyluric acid is the true 3-methyluric acid, the other two com-pounds being mixtures containing more or less 9-methyluric acid.38Further evidence, however, based on an examination of the crystal-line form, absorption spectra, solubility, and acid strength of thethree substances leads t o the conclusion that the a-acid also isreally a molecular compound containing both the S-methyl- andthe 9-methyl-uric acids .39The rest of this series of papers is occupied with an account ofderivatives of various uric acids which i t is unnecessary to cataloguein detail in this place.40The Ipecacuaizha Alkaloids.During the period covered by this Report a considerable advanceIn has been made in our kno,wledge of the ipecacuanha alkaloids.33 H.Biltz and M. Heyn, Annalen, 1916, 413, 7 ; L4., i., 286.31 H. Biltz and M. Heyn, ibid., G O ; A . , i, 280.35 H. Biltz and M. Heyn, ibid., 68 ; A . , i , 289.36 H. Riltz, M. Heyn, and M. Bergius, ibid., 7 7 ; *4., i, 290.37 H. Biltz and M. Heyn, ibid., 87 ; A . , i , 291.38 H. Biltz and 31. Heyn, ibid., 98; A . , i, 292.39 E. Biilmann and J. Bjerrum, Ber., 1916, 49, 2515 ; 1915, 50, 887 ;A., i, 177, 688.4O H. Biltz, K. Strufe, P. Damm, and M. Heyn, Annalen, 191G, 413, 124 ;A., i, 293; H. Biltz, M. Bergius, and F. Max, ibid., 1917, 414, 54; A.,i , 5S9.F* 140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.1914,41 three alkaloids from this source had been examined :eiuetine, cephaeline, and psychotrine, and the relations betweenthen1 had been established.Psychotrine was found to have theconipositioii C,8H3,,0,N,. On reduction, i t yielded a mixture ofcephaeline and isocephaeline, both of which had the compositionC,,H,,O,N,. Emetine was shown t o have the formula C,,H,,04N,and to be the monomethyl ether of cephaeline. On oxidation,emetine yielded 6 : 7 - dimethoxyi.~oquinoline - 1 - carboxylic acid,thereby establishing the fact t h a t the alkaloids belonged t o theisoquinoline group.Anew alkaloid has been isolated, which proves to be the O-methylether of psychotrine, and has, in consequence, been named methyl-psychotrine. On reduction it yields three bases, namely, emetine,isoemetine, and a third substance termed for convenience " Base C'.',Along with methylpsychotrine occurs yet another base, to whichthe.name '' emetamine " has been given. Methylpsychotrine anderrietine when oxidised produce rubremetine.Psychotrine and methylpsychotrine contain the imino-group, andit appears probable that the reduction of methylpsychotrine resultsin the saturation of an ethylenic linking, and not of the linkingC:N. The fact t h a t the reduction of psychotrine (or of its methylether) results in the formation of two isomeric compounds isascribed t o the creation of a new asymmetric carbon atom in themolecule of the reduction product.The following table indicates the relations existing between thomembers of the group and their derivatives:An extension of this investigation has now been published.42Cephaline - methyla- ---+ EmetineC,,H,,O,N, tion (329 H, 0°4N2 Oxido tionHubremetine.?+H2 ?+H2 ---+Psydotrine - rnethyla- + Mithyl- osi~stio~'28 A36°4N2 tion psychotrine ,/*I I$+HZisocephaeline'2RH 38'dN2Base CC28H30S8N2 Or C29H3803N2Two other papers have been published,4~~ 44 but they do not throwthe same amount of light on the problem.4 1 F.H. Carr and F. L. Pyman, P., 1913, 29, 226 ; T., 1914, 105,1591.4 * F. L. Pyman, T., 1917, 111, 419; A . , i, 410.43 0. Keller, Arch. Pharm., 1917, 255, 75 ; A., i, 400.44 P. Karrer, Ber., 1917, 50, 5S2 ; A., i, 409ORGANIC CHEMISTRY. 141Corydalis d llkloids.The complications introduced by steric factors are well exempli-fied in the case of the corydalines.4j When dehydrocorydaline isreduced, two corydalines are produced.Both are, inactive, and i tappears that they are probably stereoisonieric, one of thein beingr-corydaline and the other 1.-mesocorydaline . By choosing theexperimental conditions properly, either of the two compoundsmay be obtained alone as the product of the reduction reactioii.Separation is effected if necessary by taking advantage of the factthat r-mesocorydaline alone crystallises from an ethereal solutionof the mixture.Now when r-mesocorydaline is resolved into its optically activecomponents, i t is found that the cl-form is not identical with natur-ally occurring d-corydaline, so that i t seemed probable that thenatural alkaloid was d-corydaline. Attempts to establish this bythe resolution of r-corydaline into its antipodes failed, so thatanother method of proof was tried.By the sulphonation ofr-corydaline i t was possible to prepare rcorydalinesulphonic acid,and this substance was then resolved by the aid of brucine. Thenatural d-corydaline, in turn, was sulphonated and its opticalactivity was compared with that of the &antipode of the syntheticsulphonic acid. The identity of the two was thus established,whence i t follows that natural aiid synthetic 6-corydalines areidentical.Yo him b i ) L e a ti d Q ilc e b rac h i rLe .The problem of the identity or non-identity of these two alkaloidshas evidently not yet been solved.46 Although they appear t o beeasily mistakabre f o r one another in purely chemical tests, i t isstated that they are distinguishable in physiological activity,*7although in their behaviour pharmacologically they have much incommon.On this ground, i t is suggested that they are not identi-cal, but are members of the same pharmacological group. Atten-tion is directed to the fact that they both, in cominoii with strych-nine, give Vitali’s reaction.Other Papers 01% t h e Blknloids.A number of papers on the cinchona alkaloids have appeared,although none of them can be dealt with in detail here. When a4 5 J. Gadamer and W. Klee, Arch. Phartn., 1916, 254, 395; &4., i , 47.’.46 Compare Ann. Report, 1916, 161.4 7 E. Filippj, Arch. Farm. sperim., 1917, 23, 107 ; A . , j, 582142 ANNUAL KEPORTS ON THE PROGRESS OF CHEMISTRY.quinine salt is treated successively with chlorine and ammonia insolution a green product, thalleioquinine, is obtained.This sub-stance ‘has now48 been examined, and i t is suggested t h a t i t ischlorohydroxy-5 : 6-diketocinchonine :co ?,H,,N( On) CH( OH)-C H,C1/\A70 fi FHC H C C‘Hto which one moleculo of ammonia is loosely attached. Somedegradation reactions in the cinchona group are described, dealingwith cinch ole up one,*^ iso~inchonine~5~ dihydrocinchotoxine,51 andcinchotine.52 A new series of ‘‘ systematic ” names for the variousalkaloids has been proposed, which may in the end help t o make thesubject clearer, although a t present i t merely burdens the readerwith a double set of titles t o remember. Some substances allied toquinine have been synthesised.53Cyanogen bromide has been employed as a reagent for opening upcertain nitrogen ring-compounds, and the new method is of especialinterest on account of the fact t h a t the point a t which it producesa rupture in the ring is different from that a t which the breaktakes place in the Hofrnann reaction of exhaustive methylation.Both hydrohydrastinine and hydrocotarnine have been tested withthis reaction, and they are found t o give good results; so it appearsas if the reaction might he of more general application.54Papers on scopoline br~mide,~S pyraconitine and pyraconine,sGpelletierine,s7 and methylpelletierine 58 may be referred to by thoseinterested in these subjects.The Bile Pigments.It will be recalled t h a t hzematine, the non-albuminous componentof the blood pigment, is the source of bilirubin, a constituent of4 8 A. Christensen, Bey. Deut. phnrm. Ges., 1916, 26, 249 ; &4., i, 51.4 9 P. Rabe, Ber., 1016, 49, 2753 ; A . , i, 216.so P. Rabe and R. Riittcher, ibid., 1917, 50, 127; A . , i, 281.5 1 A. Kaufmann and P. Haensler, ibid., 702 : A . , i, 472.53 A. Kaufmann, E. Rothlin,and P. Brunnschweiler, ibid., 1916, 49, 3299 ;53 P. Rabe,.R. PastBrnack,and K. Kinder, i b i d . , 1917, 50, 114 ; A., i, 284.i34 J. von Braun, ibid., 1916, 49, 2624; A . , i, 163.5 5 E. Schmidt, Arch. Pharm., 1917, 255, 7 2 ; A., i, 409.5t3 H. Schulze and A. Liebner, $bid., 1916, 254, 667;K. HOSS, Ber., 1917, 50, 368; A., i, 349.6 8 K. Hem and A. Eiohel, ibid., 380; A., i, 350.A . , i, 50.A . , i, 470ORGANIC CHEMISTRY. 143bile. I n the present year, the chemistry of bilirubin has advanceda stage, although i t must be confessed that the new work rendersthe problem of the bilirubin constitution even more complicatedthan before.Crystalline bilirubin obtained from the gall-stones of the ox hashitherto been constantly associated with some sulphur compoundwhich is difficult to remove ; but a recent research 59 has brought tolight a method of purification that appears to answer admirably.From the crude bilirubin, a compound, bilirubin-ammonia, is pro-duced by the action of ammonia in dry methyl alcohol, and exam-ination shows that this new derivative is a mixture of two sub-stances, to which the names bilirubin-ammonia-A and bilirubin-ammonia-B have been given. The A-substance is stable, whilst theR-modification is unstable. When boiled with chloroform, bothsubstances yield a parent bilirubin, and as these are slightly differ-ent in properties they are designated as bilirubin-A and bilirubin-l).Both of them are free from sulphur, but they contain traces ofchlorine derived from the chloroform. Further purification hytreatment with methyl alcohol and ammonia and a final boilingwith methyl alcohol results in complete purification.I n this way, two bilirubins, known as bilirubin-A A and bili-rubin-BB, are obtained, which appear to be isomeric compounds ofthe composition C3,H3,0,N,.An investigation of the properties of these two substances showsthat the A-compound is partly converted into the B-modificationucder the influence of ammonia, whilst the reverse change isfavoured by the presence of chloroform. It is suggested thatbetween the -4- and B-compounds there may exist several other(intermediate) bilirubins.Those who have followed this intricate subject during the lastfew years and who have watched with increasing scepticism thelaunching of formula after formula, will perhaps feel but littleenthusiasm in their minds for the latest offspring of this class; butC====Z C--- CCMeICMe: C--C*CI=== C 1 >NH NLCH,*CH,/IC( 0 H)=--- CY Me \ CO,H*CH,*CH,*GCMeKueter's formula for bilirubin.6 9 W. Kiister, Zeilsch. physiol. Chem., 191 7, 99, 86 ; A , , i, 421144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.for the sake of historical completeness i t may be well to, includeKiister’s recent suggestion in the hope that possibly it may turnout t o be a true expression of the structure of this puzzling sub-stance.The A nthocyunitis a~id other Ylcitit C’olouring Mirtters.During the period which falls t o be dealt with in the presentReport, the study of the anthocyanins has been extensive; but theresults do not lend themselves to sunimarisation in a readable form,as they are concerned less with the constitution of typical sub-stances than with an examination of numerous anthocyanins drawnfrom many different plants. From this wide-ranging investiga-tion,GO however, it is becoming clear that the almost infinitediversity of colour and tint exhibited by flowers does not implythe existence of an equally diverse series of plant colouring mate-rials. Even from the results which have already been establishedi t seems reasonable t o conclude that tliroughout the flower kingdomonly comparatively few basal colouring materials are distributed ;and from these simple foundations the infinite variety of floralshades and colours is built u p by slight alterations in structure, suchas methylation, or by varying the type, number, and mode cfattachment of sugar molecules t o the chromophoric part of thecolouring matter. Pelargonidin, cyanidin, and delphinidin seemto play a preponderant part in the chemistry of plant colouringmaterials.Thus the scarlet-red flowers of Salvia coccitzea and S. splendenscontain an anthocyanin, salvianin, which has been shown t o be aglucoside of pelargonidin, although i t differs from any of thehitherto discovered pelargonidin derivatives. The foundation oftha colour of the winter aster (C‘hrysanthemeum indicum, L.) isfound to be a cyanidin monoglucoside, whilst the colour of thesummer aster (Callistephrts Chinensis) is due t o the presence ofpelargonidin. The plum, the cherry, and the sloe owe their tints tocyanidin. The pansy is found t o contain a delphinidin glucoside,termed violanin. Delphinidin is found also, in the form of deriv-atives, in petunias. Even the poppy seems t o owe its colour t o oneof the previously known basal compounds.From this i t becomes evident that the study of the plant colour-in2 materials will not be so difficult in the future as it appearedlikely to be when the work was begun. Instead of facing aninfinite variety of individual pigments, the investigator has, in6o R. Willstatter, E. I<. Bolton, C. L. Burdick, E. H. Zollinger, and F. J.Weil, Annulen, 1916, 412, 113; A., i , 42ORGANIC CHEMISTRY. 145geceral, fewer complications to unravel, for a t the backbone of thesubject i t seems probable t h a t there stand only a limited numberof chromcphoric groups which have been pressed into service andburned to t h s most varied uses by different plants.Some other work in the same branch of the subject must bementioned. An examination has been made61 of four typicallichens which are used in Ireland for the domestic dyeing of woolin yellowish-brown shades. The most interesting fact which hascome to light in this work was found in the case of Pnrmelict snan-tilis. This yielded stereocaulic acid and salazinic acid. The latterconipouiid is colourless, yet in spite of this it is the chief dyeingconstitcent, as i t acquires a t i n t on oxidation.A synthesis of hydroxyquercetin has been carried out on thelines of Kostanecki’s quercetin synthesis.62A. W. STEWART.H. Ryan arid W. M. O’Riorclan, Proc. Roy. Irish .-2cd., 1017, 33, 91;A . , i, 342.E 2 M. Nierensteiii, T., 1917, Ill, 4 ; A . , i, 119

ISSN:0365-6217    

DOI:10.1039/AR9171400061

出版商:RSC    

年代:1917

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THE influence of the war on chemistry in general is reflected inthe utilitarian character of many of the recent contributions toanalytical chemistry, which have dealt with methods for the ex-amination of industrial by-products or of substances to take theplace of those no longer available. This lack of materials has alsoled to the introduction of methods alternative to those involvingthe use of reagents, such as glycerol, methyl alcohol, and aceticacid.1 which are now practically unobtainable, whilst alloys con-sisting, in the main, of gold and palladium have been used in placeof platinum for the manufacture of chemical apparatus.2A large proportion of the analytical papers published duringthe past year has been of American origin, and there has been apronounced diminution in the number of European contributions.Some of the latter, published in 1916, were not available in timefor the Annual Report of that.year, and are therefore mentionedin the present one.I n connexion with analytical apparatus, mention should also bemade of a paper dealing with the tests to which porcelain labora-tory vessels should be subjected.3Physical Metlbods.It, was pointed out in last year s Report 4 that the method nowin common use of stating the results of viscosity tests in theempirical degrees of particular instruments was unsatisfactory,however carefully those instruments had been standardised, andthat to bring the test into line with other physical tests it wasadvisable that all results should be expressed in terms of absoluteviscosity.This is especially necessary in the case of new methods,or of those in which new types of instruments are used, which haveAlso Met. Chem.Compare T. Back, Wien. klin. Woch., 1917, 30, 465 ; A . , ii, 520.See Fahrenwald, J . Ind. Eng. Chem., 1917, 9, 509.H. Watkin, J . SOC. Chem. Ind., 1917, 36, 749.Ann. Report, 1916, 165.Eng., 1917, 16, 533.ANALYTICAL CHEMISTRY. 14’7not yet been subjected to variable conditions of working. Thisnecessity has been recognised by the authors of new methods devisedduring the past year. One of these methods is intended for theexamination of minute quantities of oil, such as are frequentlyseparated in analytical work, for which the ordinary standardinstruments are quite unsuitable.5 The apparatus, which is termeda ‘‘ mercurial viscometer,” consists essentially of a capillary tube, inthe middle of which is blown a small bulb.The tube has a stop-cock a t the base and a receiving cap at the top, and is surroundedby a water-jacket a t the required temperature. The tube is filledwith mercury, and the oil is introduced into the cap so that i t restson the mercury, and is brought to the definite temperature. Thetap is then opened, and the time taken by the mercury in fallingfrom a point above to a point below the capillary bulb is recorded.The efflux velocity may be converted into Redwood degrees bymeans of the formulaR = k ,dwhere t represents the observed time, cl the density of the oil atthe temperature of the test, and Ic a constant, which may be obtainedby parallel determinations in this and in Redwood’s instrument ofthe efflux velocity of some oil of which larger quantities are avail-able.The absolute viscosity may also be calculated by means ofa simple formula, since variations due to the “ head ” of so smalla quantity of oil o r to differences in the specific gravity are negli-gible; but i t is essential to accuracy that the dimensions of thecapillary bulb tube should be such that the oil does not fall witha sinuous motion.The standard instruments are also unsuitable for use with veryviscous fluids, and the absolute viscosity of such liquids may bemore conveniently determined by means of a method based on themeasurement of the velocity of the fall of a smooth, rigid sphere,such as a polished steel ball, through the liquid.6 The absoluteviscosity may be calculated by the application of Stokes’s law,K SglZ‘(s - s’)-7v- ’where Ii‘ represents the coefficients of viscosity, V the observedvelocity of fall, g the gravitational constant, s the density of thespherical body, s‘ that of the liquid, and R the radius of the sphere.Corrections based on data empirically determined must also beF.M. Lidstone, J . SOC. Chern. Ind., 1917, 36, 270.S. E. Sheppard, J . Id. En3. Chern., 1917, 9, 523; A . , ii, 359148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.applied, since Stokes's law demands that the liquid shall be ofinfinite extent.The value of the spectroscopic method of identifying phenolshas, in the main, been confirmed, but the method demands themost' accurate observation, and it is therefore advisable to make agraph of the absorption bands shown by various solutions of thephenol derivatives.*A physical method9 affords the most rapid means of accuratelyestimating the strength of sulphuric acid .I0 The heat' of dilutionof the acid with water is measured, a vacuum-jacketed tube beingused as calorimeter, and the amount of sulphuric acid is calculatedby means of the formulaII: = 100 - 7.6 (3.994 - R),which is based on the mean volume of acid delivered by thepipette, the water equivalent of the calorimeter, and the meanresults obtained by Pickering.llAn interesting application of a physical phenomenon as ailindicator in analytical work has been introduced.12 In titratinglead with ammonium molybdate solution, the colloidal leadmolybdate suddenly coagulates when the reaction is complete, andthe end-point may be ascertained more sharply in this way thanby using tannin as indicator.Gas A ~ r l y s i s .There has been further discussion as to the relative merits ofdifferent absorbents for oxygen in gas analysis.13 The use of asolution of sodium pyrogallol*4 is admitted to be cheaper and aspecifically more effective absorption agent than potassium pyro-gallol, but these advantages are more than counterbalanced by thelonger time required for complete absorption of the oxygen .I 5Another reagent recommended as a substitute for alkaline pyro-gallol is a 10 per cent.solution of hyposnlphite of zinc or sodium.IaFor the estimation of ozone in air, a method has been basedon the fact that a solution of ammonium ferrous sulphate is.7 H. GselI, Zeitsch. anal. Chem., 1916, 55, 417 ; A., 1916, ii, 584.J. Formanek and J. Knop, ibid., 1917,56,273 ; A . , ii, 503.H. D. Richmond and J. E. Rlerreywethcr, Analyst, 1917, 42, 273 ; A . ,ii, 503.10 Compare H. Howard, J . SOC. Chem. Ind., 1910, 29, 3.l1 T., 1890, 57, 64.12 J. F. Sacher, Kolloid-Zeitsch., 1916, 19, 276; A . , ii, 180.13 See -4nn. Report, 1916, 168.14 J. W. Shipleg, J . Amer. Chem. Soc., 1916, 38, 1687; A . , 1916, ii, 571.16 R P. Anderson, J . Ind. Eng. Glum., 1916, 8, 999; A . , ii, 39.16 L. Deacamps, Bull.Assoc. chim. Sucr. Pi&., 1916, 34, 34 ; A., ii, 216ANALYTICAL CHEMISTRY. 149immediately oxidised by ozone, but not by air free from ozone,and 011 the titration of the unoxiclised iron salt by means ofstandard permanganate solution.17The objection to this method is that i t is not specific for ozone,the ferrous salt being oxidised as readily by hydrogen peroxide asby ozone. Similar criticism may be brought against other methods,such as those in which the ozone is oxidised by potassium per-manganate,ls or in which potassium iodide or bromide is used asthe reagent.19 The most trustworthy method of estimating atlmo-spheric ozone in the presence of nitrogen oxides and hydrogenperoxide is by the use of a slightly alkaline solution of sodiumnitrite.20 This is oxidised to nitrate by ozone, whilst nitrogen per-oxide yields nitrate and nitrite, and hydrogen peroxide is notaffected. I n making an estimation, two samples of the air aretaken, one of which is passed through a tube containing chromicacid and manganese dioxide, and the other through a tube con-taining chromic acid only.The nitrite solution is then introducedinto the two bottles, aiid the amount of nitrite subsequentlyestimated colorimetrically. The first bottle will contain onlynitrogen peroxide, and the increase in the quantity of nitrite willafford a measure thereof; in the second bottle, both ozone andnitrogen peroxide will be present, and the difference between thetwo estimations will be equivalent to the ozone present.The method of estimating gasoline vapour in air by combustionand condensation with liquid air21 has been found to be1 untrust-worthy, the combustion being incomplete when more than 5 or 6per cent.of gasoline is present!22Since colorimetric methods, when trustworthy,23 have theadvantages of speed and sensitiveness, a colorimetric methodof estimating carbon dioxide in the air appears likely toprove a useful addition to tests which have often to be em-ployed a t a distance from the laboratory.24 The principle ofthe process is that when a solution of sodium hydrogen carbonatebecomes saturated with the carbon dioxide present in a current ofair, the reaction of the liquid will afford a measure of the relativeamounts of carbon dioxide and sodium hydrogen carbonate, whilstDavid, Compt.rerzd., 1917, 164, 430 ; A . , ii, 216.E. H. Keiser and L. McMaster, Amer. Chem. J . , 1908, 39, 96.l9 Compare W. Hayhurst and J. N. Pring, T., 1910, 97, 868.* O F. L. Usher and B. S. RSLO, ibid., 1917, Ill, 799; A., ii, 602.21 G. A. Burrell and I. W. Robertson, J . Ind. Eng. Chem., 1915, 7, 112;22 R. P. Anderson, ibid., 1917, 9, 142; A . , ii, 338,23 Compare W. M. Dehn, J. Amer. Chem. SOC., 1917, 39,1392; A., ii, 499.24 H. L. Higgins and W. M. Marriott, ihid., 6 8 ; A., ii, 270.A., 1915, ii, 184150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the proportion of carbon dioxide absorbed is a function of itspartial pressure iii the particular air and is not affected by thevolume of air wliich passes through the liquid after the latter hasbeen saturated with carbon dioxide.I n applying the test, the air is passed through a standard solu-tion of sodium hydrogen carbonate containing a suitable indicator,such as phenolsulphonephthalein,25 until no further change ofcolour appears, and the colour is then compared with those ofstandard solutions of potassium hydrogen phosphate and disodiumhydrogen phosphate prepared to correspond with air containingknown quantities of carbon dioxide.A method of estimating gases of the argon group has been basedon the fact that, unlike nitrogen and other gases, they are notabsorbed by metallic calcium heated to dull redness (450O to 550°).26Argon may thus be directly separated from air, but in the caseof gaseous mixtures, a preliminary separation of such gases ascarbon monoxide, carbon dioxide, and methane is advisable.ApicuZtu~*aZ .4 nalysis.There have been few additions during the past year to analyticalprocesses as applied to agriculture, although several well-knownmethods have been studied and modifications of them devised witha view to obviate possible errors.For example, in the estimation of nitrates i n soil by the phenol-disulphonic acid metliod,27 i t has been found that the colour of thereaction mixture is affected by light, and that the comparison musttherefore be made as rapidly as possible. The loss of nitratescaused by the presence of chlorides and sulphates may be p e -vented by adding a small excess of calcium hydroxide before theevaporation and flooding the residue with a large excess of thereagent.By the use of this modification, no loss of nitrates needbe feared if potassium alum, which is the most efficient flocculatingagent, be used for treating the soil solution.2PAmmonia may be accurately estimated by slowly distilling amixtare of the soil with magnesium oxide and water underdiminished pressure, and finally passing a current of ammonia-freeair through the flask. The distillate is collected in standardCompare H. A. Lubs and S. F. Acree, J . Amer. Chem. SOC., 1916, 38,p6 A. Sieverts and R. Brandt, Zeitoch. angew. Chm., 1916, 29, 402; A.,3772 ; A,, ii, 97.ii, 103.C. W. Davis, J . Ind. Enq. Chern., 1917, 9, 290; A., ii, 329.See Water Analysis, p.169ANALYTlCAL CHEMI.STHY. 151sulphuric acid, which is subsequently titrated with standard alkali,Congo-red being used as indicator. In addition to ammonia,volatile amines and bases will also distil, but the ammonia maybe separated by precipitation as ammonium magnesium phosphateand distillation of the precipitate with sodium hydroxide. It hasbeen found, however, that the amounts of amines and volatilebases distilling with the ammonia, either from soils or liquidmanures, are practically negligible.29I n the estimation of nitrogen in soils by the Gunning method,the addition of a small amount of copper wire during the digestioncauses the subsequent distillation to proceed more regularly, whilstthe results will then agree closely with those obtained by Kjeldahl'sinethod.30The method of estimating organic carbon by combustion withcopper oxide frequently gives higher results than the wet method,in which potassium dichromate and sulphuric acid are used forthe combustion.This does not necessarily prove that the formermethod is the more accurate, for it has been found that in thecase of soils which contain calcite included within quartz grains, thecombustion with copper oxide causes liberation of carbon dioxidefrom the calcite.31A convenient apparatus has been devised for the rapid estima-tion of carbon dioxide from the carbonates in soil. The flask inwhich the soil is treated with hydrochloric acid is connected witha mercury manometer, and the pressure of the gas acts on a float,the movements of which are mechanically recorded.The rate ofevolution of the carbon dioxide thus affords an index of the natureof the carbonates in the ~0i1.32Further attention has been given to the question of the solu-bility of phosphates in acids.33 It has been found that certainorganic acids dissolve more phosphoric acid from superphosphatesthan from mineral phosphates. The high solubility of phosphoricacid in citric acid solutions is due t o the formation of a complexcitrophosphate in combination with aluminium and ferric iron,and it is probable that similar complex compounds are formed inthe case of other organic acids, such as formic and acetic a ~ i d s . 3 ~Both tricalcium and dicalcium phosphates are soluble in 2 perl9 W.I. Baragiola and 0. Sohuppli, Landw. Versuchs-Stat., 1917, 90,a0 W. L. Latshaw, J . Ind. Eng. Chem., 1016, 8, 1127; A., ii, 100.E. C. Shorey and W. H. Fry, ibid., 1917, 9, 685; A., ji, 423.3a Q. Hutin, Ann. CA,im. anal., 1917, 22, 158 j A . , ii, 541.O3 See Ann. Report, 1916, 170.ii4 A. Ah, Ann. Chim. Applicata, 1917, 9, 200.123 ; A., ii, 380152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYcent. citric acid solution, and helice this reagelit, cannot be used t odifferentiate between the two phosphates, as commonly accepted.This affords a further reason against the use of the citric acidmethod of estimating phosphoric acid .35The Pemberton method of estimating phosphoric acid by pre-cipitation as phosphomolybdate gives trustworthy results providedthat the precipitation is made with not too old a reagent andbetween 30° and 40°.I n applying the method to acid phosphates,it is advisable to make a parallel estimation on a standard phos-phate rock, adding the same amount of sulphuric acid, after solu-tion in nitric acid, as was used in the case of the sarnple.36Organic Analysis.Qzditative.-The principal addition, during the past year, tothe methods of identifying organic compounds has been based onthe properties of the various crystalline derivatives formed by theinteraction of p-nitrobenzyl bromide and alkali salts of organicacids. These esters have definite melting points and differ in theirsolubility in alcohol, and so may be used for distinguishing betweenthe different acids in a mixture.37 By this means, it has beenfound possible to identify benzoic acid in presence of acetic, tartaric,citric, salicylic, and ptoluenesulphonic acids, but the method isless suitable for the identification of aliphatic acids, many of whichyield oily instead of crystalline derivatives.38 I n some cases, theuse of pnitrobenzyl chloride or iodide is preferable, the iodide, forinstance, yielding with dibasic acids very insoluble esters, fromwhich the unaltered iodide can readily be separated.39A modification of the method may be used for the identificationof alcohols.The alcohol is heated with phthalic anhydride, andthe sodium salt of the resulting acid est'er is converted by meansof p-nitrobenzyl bromide into the corresponding mixed phthalicester, which in many cases has a distinctive melting point.40Phenols also may be identified in a similar manner by tmhecharacteristics of the ethers obtained by the interaction of thepotassium o r sodium phenoxide and p-nitrobenzyl bromide.41A new method of identifying the fatty acids in a fat is basedon the hydrolysis of glycerides by heating them in a sealed tube36 A.A. Ramsay, J . Agric. Sci., 1917, 8, 277; A.,ii, 413.36 P. M. Shuey, J . I n d . E n g . Chem., 1917, 9, 367 ; A., ii, 269.8' E. E. Reid, J . Amer. Chern. SOC., 1917, 39, 2 4 ; A., i, 333.3* E. Lyons and E. E. Reid, ibid., 1727; A., i, 559.39 J. A. Lyman and E. E. Reid, ibid., 701 ; A., i, 334.40 E. E. Reid, ibid., 1249; A,, i, 455.41 E. E. Reid, ibid., 304; A., i, 333ANALYTICAL CHEMISTRY.153with a11 aromatic amine, such as aniline or a-naphthylamine, theresulting amides having distinctive melting and boiling pointsunder diminished pressure. The decomposition is not quantitative,but is approximately proportional to the amounts of fatty acidspresent .42Another new group-reaction has been based on the formation ofazomethines by the condensation of aromatic aldehydes withsulphonated aromatic amino-compounds. Many of these azo-methines have characteristic colours, which may be used for theidentification of the aldehydes.43A general method for the detection of aldehydes, ketones, andphenols in essential oils depends on the fact that these compounds,unlike alcohols and hydrocarbons, give distinctive colorations withsodium arsenotungstate or arsenotungstomolybdate.44Turning to the reactions of individual Substances, it will befound that a few new tests have been devised, and the sensitive-ness of some of the older tests has been ascertained.For thedetection of hydrocyanic acid ,45 the guaiacol, or Schonbein-Pagenstecher's method, is the most sensitive reaction, being c a pable of detecting 0*00001 per cent. of cyanogen, but it is not specific,and for general purposes the Prussian blue test is the most trust-worthy, although under certain conditions the thiocyanate testmay be useful. The picric acid test is less sensitive than any ofthese tests, and has also the drawback that similar colorations areobtained with reducing substances, such as sugar and sulphurdioxide.46Both citric and malonic acids are oxidised by an acetic acidsolution of potassium permanganate to acetone, which may beidentified by the iodoform test. Citric acid may then be dis-tinguished from malonic acid by yielding a crystalline bariumci t rat e .47A solution of titanic acid in sulphuric acid affords a means ofdistinguishing between the two naphthols, a-naphthol giving abright green and &naphthol a blood-red coloration .48Resorcinol may be detected by the green coloration which itgives with a solution of cobalt chloride followed by concentratedammonia and alcohol. Under similar conditions, catechol and42 E. de'Conno, Gcrzzetk, 1017, 47, i, 93: A . , i, 356.43 P. Pooth, Schweiz. Apoth. X e d ., 1916, 54, 357 ; A . , ii. 52.4 4 1,. Cuglidmelli, Ana?. SOC. Q7tim. Aqwntinn. 1917, 5, 1 1 ; A , , ii, 514.4 6 See -4n)i. Repopt, 1916, 173.4 8 Q. TV. Anderson, J . Soc. Chew. Ind., 1917, 36, 195 ; A . . ii, 183.4 7 T. C. N. Broeksmit, P?aco.m. Ti'eekbEntl, 1917. M, 686 ; A . , i i , 429.48 G. Deniggs, Ann. China. anal., 1016, 21, 343 ; A . , ij, 4s154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.pyrogallol give a brown coloration, whilst a solution of phenolremains colourless.49This sugar,when heated with o-tolylhydrazine, yields an o-tolylhydrazone(in. p. 1 7 6 O ) , whereas no corresponding hydrazone is formed byarabinose, xylose, rhamnose, dextrose, mannose, or laevulose.50Quantitative.-As the micro-balance required for Pregl’s methodof micro-combustion 51 is now unobtainable, a modification of themethod has been devised, in which larger quantities of material(11 to 22 milligrams) are weighed with an ordinary balance.Thepacking of the combustion tube has also been modified, whilst soda-lime in a tube with a ground-in joint replaces the potash absorptionbulb. A ‘‘ blank” estimation should be made under parallel con-ditions t o obtain the correction for the hydrogen results, whichare sometimes 0.1 t o 0.15 per cent. too high. With this correction,the results agree well with those obtained by the ordinary methodsof combustion.52For the rapid estimation of halogens in organic compounds, thesubstance is fused with a mixture of sodium peroxide, potassiumnitrate, and powdered benzoic acid or sucrose (to ensure uniformfusion).The oxidised mixtire is treated with excess of silvernitrate prior to acidification with nitric acid, and the excess ofsilver titrated. Hydrazine sulphate is added to the hot solutioncontaining the precipitated haloid to reduce any halogen oxy-acidswhich may have been formed.53A trustworthy method of estimating silver in organic compoundshas been based on the interaction of alkali cyanides and silversalts, and precipitation of the silver in the metallic form or assulphide from the argenticyanide solution.54I n the ordinary method of estimating mercury in organic com-pounds by combustion with quicklime, the distilled mercury isfrequently contaminated with tarry matter. This may be obviatedby mixing the mercury compound with dry calcium sulphate andexcess of quicklime, and distilling the mercury in the usual way.55I n estimating ethyl alcohol by DuprB’s method,56 the preliminary4 9 F.C. Krauskopf and G. Ritter, J . Amer. Chem. SOC., 2916, 38, 2182:5 0 A. W. van der Haar, Rec. tmv. chiin., 1917, 37, 108 ; &4., ii, 515.61 E. Abderhalden, “ Handbuch der Riochem. Arbeitsmethoden,” [ii], 5,62 L. E. Wise, .J. -4nzer. Chew. SOC., 2917. 39, 2056 : -4., ii, 541.53 J. I?. Lemp and H. G . Broderson, ibid., 2069 ; A . , ii, 539.6 4 H. J. Lucas and A. R. Kemp, ibid., 2074; A . , ii, 542.5 5 J . E. Marsh and 0. G. Lye, dnalyst, 1917, 42, 84; il., i i , 219.5 6 A. DuprB, Jocirn. Chem. Soc., 1867, 20, 495.A new reaction for d-galactose has been described.A ., ii, 48.1307ANALYTICAL CHEMISTRY. 155separation of the alcohol is often not quantitative. Better resultsmay be obtained by removing the alcohol by means of a current ofair, absorbing it in concentrated aulphuric acid, oxidising the mix-ture with potassium dichromate solution, and distilling the aceticacid. Acetaldehyde and ethyl acetate also yield acetic acid onoxidation, whilst methyl alcohol is oxidised t o carbon dioxide andwater, but acetone is only slightly ~xidised.~'The most satisfactory means of estimating water iii alcohol is todetermine the specific gravity of the liquid before and afterdehydration with potassium carbonate.58 The percentage of alcoholmay then be obtained by reference to a curve.59A new method of estimating butyric acid mixtures containingalso formic acid and acetic acid depends on the solubility ofquinine butyrate and the insolubility of quinine formate andacetate in carbon tetrachloride.Quinine butyrate may beidentified by its melting point, 77.5O.WA large amount of experimental work has been done in con-nexion with Duclaux's method of estimating volatile fatty acidsby distillation in a current of steam,61 and various applications ofthe method have been tested. Experiments with mixtures of purepropionic, butyric, valeric, and hexoic acids have shown that thevalues obtained under the specific coiiditions previously deter-mined62 may be regarded as trustworthy. When only two acidsare present, the amount, of each may be obtained from the resultsof the distillation, and the ratio between them calculated for eachfraction.I n the absence of other acids, there should be a fairlyclose agreement between the ratios, and the mean ratio will givean indication of the molecular proportion.63 By a slight, modifi-cat*ion, the method may be used for the estimation of butyric acidin acetic anhydride and for testing the purity of substitutedmalonic acids.64I n one modification of the method, the volume of the aqueoussolution is kept a t a constant volume of 150 C.C. Under such con-ditions, the results, when plotted on a logarithmic chart, form astraight line in the case of a single acid, but a curve when a mix-5 7 A. W. Dox and -4. R. Lamb, J . Amer. Ckem. SOC., 1916, 38, 2561; A , ,68 Compare E.Mallinkrodt and. A . D. Alt, J . Iizd. EMJ. Chew., 1916, 8,5 9 R. L. Perkins, ibid., 1917, 9, 5 2 : -4., ii, 393.c o J. K. Phelps and H. E. Palmer, J . Rid. C'henz., 281i, 29, 199 ; A . , i i , 278-E. Duclaux, Ann. Insf. Paslew, 1895, 9, 265 ; A . , 1896, ii, 604.H. D. Richmond, Anatyst, 1908, 33, 305 ; A . , 1908, ii, 495, 754.H. D. Richmond, ibid., 1917, 42, 125; A . , i, 316.H. D. Richmond, ibid., 133 ; A., ii, 277.ii, 47.507; A , , 1916, ii, 583156 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ture of acids is present, and the probable composition andapproximate proportion of these acids may be found by referenceto the chart.65The method has been subjected to criticism on the ground thatby the use of Duclaux's constants, practically identical results maybe calculated for mixtures of totally different proportions ofacids;66 but' in reply to this criticism, experiments have been citedto show that the figures are quite trustworthy when based onresults obtained with pure acids, although not more than threeacids can be satisfactorily estimated in the same fraction.67 Iffour or more acids are present, it is essential to separate the liquidinto fractions containing three acids.The main essential is thatthe distillation should always be made in a uniform manner.6*It is a general, although incorrect assumption, that in estiin-ating phenol in tar acids, the fraction distilling up to about ZOOocontains the whole of the phenol.69 It is possible, however, by theaddition of a suitable proportion of o-cresol t o prepare a mixturewhich will yield the whole of its phenol in the first fractions ofthe distillate.70 By determining the crystallisation points ofsuccessive fractions distilled from a tar oil and reference to a table,the proportion of phenol may be estimated with sufficient) accuracyfor commercial purposes.71 For more accurate work, however, it isnecessary to distil the purified sample under standard conditionsand to redistil the united lower fractions, so as to obtain a finalfraction distilling up to 1 9 7 O .From the specific gravity andcrystallisation point of this fraction, the percentage of phenol maybe obtained by reference to standard curves.72A colorimetric method of estimating minute quantities of anilinehas been based on a comparison of the coloration given by thesolution on treatment with standard solutions of calcium hypo-chlorite and sodium hydroxide with the colorations obtained underthe same conditions with standards containing up to 0.07 milli-gram of aniline. The method is accurate within about 0.003milligram.736 5 D.C. Dyer, J . Biol. Chem., 1917, 28, 445 ; A . , ii, 157.6 6 F. W. Upson, H. M. Plum, and J. E. Schott, J . Amer. Chem. SOC., 1917,6 6 L. J. Gillespie and E. H. Walters, ibid., 2027 ; A., ii, 549.69 Compare R. Masse and H. Leroux, Compt. rend., 1916, 163,361 ; A . ,7 0 J. J. Fox and M. F. Rnrker, J . h'oc. Chew. Ind., 1917, 36, 842; A . ,71 R. Masse and H. Leroux, BdI. SOC. c l i h ., 1917, [iv], 21, 2.72 J. 31. Weiss and C'. R. Downs, J . Ind. Eng. Chem., 1917, 9, 569 ; .4,,73 E. Elvove, ibid., 953 ; A . , ii, 554.39, 731 ; A . , ii, 277. 6' A. R. Lamb, ibid., 746: A., ii, 277.1916, ii, 650.i i , 513.ii, 428ANALYTICAL CHEMISTRY. 15'7The inetliod of estiniatiiig nit rotolueiies by reduction withstannous chloride, followed by the addition of alkaline tartrateand titration with iodine, is not altogether trustworthy, especiallywhen alcohol has to be used to dissolve the compound. Betterresults may be obtained by omitting the treatment with alkalinetartrate and titrating the excess of stannous chloride with an acidsolution of iodine. The results are usually about 96 per cent.below the theoretical amounts.74A few new methods of analysing fats have been introduced.Glycerides may be fractionally separated by dissolving the fat intwo or more solvents, such as alcohol and ether, one of which ismore volatile and has a greater solvent action than the other.Then, by aspirating air through the solution, gradual evaporationaccompanied by a considerable reduction of temperature takesplace, and the glycerides may be successively removed as theyseparate in the order of their insolubility. Similar fractions arecombined and subjected to further fractionation. By this means,the mixed glycerides, oleodistearin and dioleopalmitin, have beenisolated from tallow.The method is also applicable to the detec-tion of beef and mutton fat in butter fat', the latter yielding avery much smaller amount of insoluble' glycerides than butt%r fatcontaining 20 per cent.of tallow .75The calorimetric method of measuring the thermal values ofoils76 has been extended to the determination of the Maumen6value, and i t has been shown that the values thus obtained understandard conditions with typical oils stand in close relationship tothe iodine values.77An analytical method based on catalytic hydrogenation has beendevised for the detection of rape oil in olive oil. An etherealsolution of the more unsaturated fatty acids, separated by thelead-ether method, is hydrogenated in the presence of finely dividedpalladium, and the resulting product is fractionally crystallisedfrom alcohol. I n the presence of rape oil, behenic acid, formedby the hydrogenation of the original erucic acid, will be obtained,and may be identified by its melting point and sparing solubilityin alcohol .78The oxidisability valne of oils79 affords a means of determining7 4 E.de W. S. Colver and E. €3. R. Prideaux, J . Soc. Chem. IwZ., 1917,7 s A. Seidenberg, J . I n d . Eng. Chem., 1917, 9, 855 ; A., i, 626.76 See Ann. Report, 1916, 180.v 7 J. W.Marden and (Miss) M. V. Dover, J . Ind. Eng. Chem., 1917, 9, 858.7 8 R. Biazzo and S. Vigdorcik, Ann. Chim. Applicata, 1916, 6, 185.7B See Ann. Report, 1916, 180.36, 480 ; A., ii, 512158 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the suitability of oils and fats for medicinal purposes. I n the caseof fresh fats, this value should not exceed 10, but castor oil, evenwhen old and having a high acid value, contains only small amountsof volatile aldehydic and ketonic compounds, and therefore showslow oxidisability values.8OReference may also be made to a simplified volumetric methodof analysing sulphonated oils, the results obtained being in closeagreement with those given by the usual gravimetric method.81For the estimation of sucrose, dextrose, laevulose, and maltose inadmixture, methods based solely on the cupric reducing powermay give erroneous results, owing to cupric oxide dissolving in thehot alkaline solution.82 I n such cases, the method of oxidising thesugars by means of bromine83 is more trustworthy.Bromineoxidises dextrose and maltose quantitatively a t the normal ternpera-ture, whilst lzvulose is only oxidised to a limited extent.Whendextrose is the only other sugar present, lzvulose may be directlyestimated by the bromine oxidation method. The results thusobtained in the analysis of honey and jam are sufficiently trust-worthy for commercial purposes, although the method is lessaccurate than the more tedious method of enzymic hydrolysi~.~~I n other cases, the method may be conveniently used in conjunc-tion with determinations of the cupric reducing power and opticalrot ation.A sensitive method of detecting and estimating laevulose in thepresence of dextrose has been based on boiling laevulose with a0.2 per cent. solution of orcein and 85 per cent. phosphoric acid, ayellow coloration being produced.This is matched with the colora-tions obtained under the same conditions with standard solutionsof laevulose. When applied qualitatively, the test is capable ofdetecting laevulose in 1 C.C. of a 0.08 per cent. s0lution.8~Free and combined galactose may be estimated by a modifica-tion of Creydt's method,86 in which the solution is oxidised withnitric acid and the resulting mucic acid separated and weighed.Tables showing the corresponding quantities of galactose have beenconstructed.87For the estimation of aldose sugars, a new method has been8o G. Issoglio, Ann. Chirn. Applicata, 1917, 7 , 187.R. Hart, J. Ind. Eng. Ghern., 1917, 9, 850.(Miss) E. G. Wilson and W. R. G. Atkins, Biochem. J . , 1916, 10, 504 ;A., 1916, ii, 652.p3 E.C. Kendall, Analyst, 1912, 37, 205 ; A., 1912, ii, 393.dl W. R. G. Atkins, ibid., 1917, 42, 12; A., ii, 157.8 6 L. Loewe, Proc. SOC. Exp. Biol. &fed., 1917, 12, 71 ; A., ii, 49.8 6 Creydt, Diss., Erlangen, 1885.O7 A W'. van der Haar, Chem. Wcekblad, 1916, 13, 1204ANALYTICAL CHEMISTRY. 159based on their quantitative oxidation by means of a solution ofiodine in sodium carbonate solution, the excess being afterwardstitrated with thiosulphate. The method has the drawback thatother substances besides aldose sugars will reduce hypoioditesolution.8*In eatimating sugars in the presence of gum arabic, the lattermay be more completely precipitated by a mixture of alcohol withbasic lead acetate than by basic lead acetate alone, but, even theii,the presence of gum in the filtrate interferes with the polarimetricestimation of invert-sugar .89I n a method of estimating glutose, the non-fermentable sugarin cane molasses, the pentoses are first' destroyed by fermentingthe dilute acidified solution for three days with a bottom-fermenta-tion yeast, and determining the reducing power of the clarifiedfermented liquid.For this purpose, the reducing power of glutoseis taken as half that of invert-sugar.90For the polarimetric estimation of starch in the presence of otheroptically active substances, advantage has been taken of the factthat lead tannate will precipitate starch, even after gelatinisationby heat. The amount of starch may be calculated from theresults of the polarisation before and after the precipitation.91A new method for the direct estimation of starch has also beendescribed, in which the starch is dissolved in calcium chloride solu-tion and precipitated with iodine, the starch-iodide being thendecomposed with alcohol and the starch weighed.92Several modifications of the methods of estimating alkaloids havebeen published.The inaccuracies of the ordinary methods ofestimating theobromine are obviated by precipitating the alkaloidas the silver compound, estimating the nitrogen in the precipitateby Kjeldahl's method, and calculating the amount of theobrominefrom the result. The presence of even considerable quantities ofcaffeine does not interfere with the estimation.93A trustworthy method of estimating morphine has been basedon its quantitative oxidation in a dilute sulphuric acid solution bymeans of iodic acid, two molecules of the alkaloid absorbing threeatoms of oxygen.Other alkaloids, including codeine and narcotine,8 8 J. Bougault, Compt. rend., 1917, 164, 1008; A . , ii, 395.8 9 G. Savini, Ann. Chim. Applicata, 1916, 6, 250.O 0 H. Pellet, Ann. Chim. anal, 1917, 22, 43; A., ii, 223.y1 C. Baumann and J. Grossfeld, Z5itsch. Nahr. Genussm., 1917, 33, 97 ;O2 T. von Fellenberg, Mitt. Lebensmittelesnters. Hyg., 1916, 7 , 369 ; A , ,93 Mrs. N. Radford and G. Brewer, Analyst, 1917, 42, 274; A., ii, 519.A., ii, 223.ii, 342160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.also absorb oxygen, so that the method is unsuitable for theestimation of morphine in opium.94Attentioii has been directed to the possibility of errors in thecolorimetric method of estimating creatine and creatinine, owingto the presence of impurities in the picric acid.Much of the com-mercial picric acid now sold gives colorations with sodium hydr-oxide, and is quite unsuitable for the pprpose of this estimation.9~Inorgatbic Analysis.Qualitatice .-A modification of Penfield's test for water maybe used for the detection of carbon in minerals and other sub-stances. The finely divided substance is mixed with lead chromate,which must be free from carbon, and the mixture is heated in ahorizontal, narrow glass tube, one end of which is closed, whilstnear the open end there is a bulb containing a clear solution ofbarium hydroxide. I n the presence of as little as 0.003 milli-gram of carbon, a white film will be produced on the surface ofthe reagent.96 Another delicate test for carbon is to heat the sub-stance with a large excess of potassium azide, which in the presenceof carbon will produce potassium cyanide, easily recognisable bythe Prussian-blue test.The reaction is rendered more sensitiveby adding metallic potassium to the mixture.97The method of detecting phosphorus by the reduction of itscompounds to phosphorus hydride by means of zinc and hydro-chloric acid is slow, but under the best conditions is capable ofdetecting 0.0025 gram of phosphorus in the form of hypophosphite.The reduction should be effected a t about 55O, the gas absorbedby means of silver nitrate solution, and the precipitate againreduced.The coloration of the phosphorus flame may be recog-nised as distinctly by the unaided eye as by the use of the spectro-Traces of manganese may be detected even in the presence ofother met,als by the rose-red coloration which they give whentreated in slightly alkaline solution with an alkali oxalate, followedby acetic acid.99The value of the hydrogen peroxide test for copper' has been94 J. N. Rakshit, J . SOC. Chem. Ind., 1017, 36, 989 ; A . , ii, 553.9 5 0. Foliri and E. A. Doisy, J . B i d . Chem., 1917, 28, 349; A . , ii, 169.90 W. G. Mixter and F. L. Haigh, J . Amer. Chem. SOC., 1917, 39, 374 ;9 7 E. Muller, J . p r . Chem., 1917, [ii], 95, 53 ; L4., ii, 269.98 H. J. Lemkes, J .Pharm. Chim., 1917, 15, 177.s9 V. Macri, Boll. chim. farm., 1917, 56, 377; A . , ii, 511.1 Compare J. Sperber, Schweix. Apoth. Zed, 1915,53, 717 ; A . , 1916, ii, 314.scope.98A . , ii, 267AN A LY TI CAL CH 6MI STRY. 161conlirmed, and it has been found that the sensitiveness of thereaction is increased by the addition of sodium hydrogencarbonate.2 The violet coloration produced when hydrogen per-oxide is treated with tartaric acid and a ferrous salt and thenwith an alkali hydroxide, is due to the formation of a ferric com-pound of hydroxytartaric acid. It is not, a trustworthy reactionfor tartaric acid, but under certain conditions may be used as asensitive test for hydrogen peroxide.3A delicate test for gallium has been based on the insolubilityof gallium ferrocyanide in dilute hydrochloric acid and the relativesolubility of the metals which are usually separated with gallium.For the separation of gallium from aluminium, before applyingthis test, the mixed chlorides may be treated with ether, in whichgallium chloride is soluble.*For the detection of germanium and its separation from arsenic,the zinc oxide or other substance under examination is distilledwith concentrated hydrochloric acid, to which potassium perman-ganate6 has been added to prevent reduction of arsenic sulphideand distillation of arsenic.I n the presence of 0*0001 gram ofgermanium, the distillate will give a white precipitate withhydrogen sulphide.6The difference between the respective solubilities of the fluoridesof calcium, barium, and strontium affords a rapid and fairly delicatemeans of detecting calcium in the presence of the other metals.On adding a solution of barium fluoride to 10 C.C.of a solutioncontaining as little as 0.003 gram of calcium chloride, a distinctturbidity is a t once produced, even in the presence of seven timesthe quantity of strontium chloride and one hundred times thequantity of barium chloride.'I n using palladium chloride as a test for iodides, i t is necessaryto take into account the fact that thiocyanates, ferrocyanides, andferricyanides interfere with the reaction. The addition of anexcess of the reagent and boiling the liquid tend to check theinterference.82 F. Mayer and W. H. Schramm, Zeitsch.anal. Chem., 1917, 56, 129 ; A .,* P. E. Browning and L. E Porter, Amer. J . Sci., 1917, [iv], 4141, 221 ; A.,Compare G. H. Buchanan, J. Ind. Eng. Chein., 1916, 8, 5 8 5 ; A., 1916,ii, 334.ii, 544.ii, 486.F. Mayer and W. H. Schramm, loc. cit.P. E. Browning and S. E. Scott, Amer. J . Xci., 1917, [iv], 44, 313 ; A . ,ii, 546.Z. Karaoglanow, Zeitsch. anal. Chem., 1917, 56, 138 ; A., ii, 333. * L. J. Curtman and B. R. Harris, J . Amer. Chem. SOC., 1917, 39, 266;A., ii, 267.REP.-VOL. XIV. 162 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Many alkaloids form insoluble perchlorates, and so may be usedfor the detection of the perchloric ion. For example, strychnine,brucine, and morphine yield perchlorates which may be recognisedunder the microscope by their crystalline form.Of the threealkaloids, strychnine sulphate is the most sensitive reagent, beingcapable of detecting the perchloric ion in a 0.1 per cent. solution.!)Q zcantitntive .-Among other criticisms against the use ofpotassium dichromate as a standard for volumetric methods,10 i thas been asserted that liberation of iodine may occur in the courseof the oxidation of the potassium iodide solution, probably owingto the formation of an intermediate iodochromat'e, ICr0,K. Sucha source of error, if unavoidable, would render the method untrust-worthy, but experiments have shown that, in the case of dilutesolutions, a t all events, there is no risk of the formation of thiscompound .11Oxalic acid, when purified by recrystallisation, is one of the mostsuitable standards for alkalimetry.12 The most accurate method ofusing it is to titrate its solution with alkali until the neutralisationpoint is nearly reached, then to add sufficient calcium chloride toprecipitate the whole of the oxalic acid, and, after the addition ofmethyl-orange, to complete the titration.Ammonia may betitrated in the same way, preferably after the addition of boricacid to prevent loss by evaporation.13The use of yellow mercuric oxide has also many advantages asan original standard, since i t is readily obtainsd in a pureanhydrous condition and is not hygroscopic. When treated witha solution of potassium iodide, i t yields an equivalent quantity ofpotassium hydroxide, and this is titrated with the acid to bestandardised, using methyl-orange, methyl-red, or phenolphthaleinas indicator.14Alkalimetric methods of estimating phosphoric acids and alkaliphosphates in admixture usually give only approximately correctresults, but by maintaining the solution at 5 5 O during each of thetitrations, i t is possible to estimate any of the alkali phosphatesin a mixture with an accuracy within 0.5 per cent.15I n many cases methyl-red (pdimethylaminoazobenzeneo-carb-oxylic acid) may advantageously replace methyl-orange as anG.Denigbs, Ann. Chim. anal., 1917, 22, 127; A , , ii, 345, 419.la Compare Ann. Report, 1916, 183.l1 G. Rruhns, J . pr. Chern., 1917, [ii], 95, 37 ; A . , ii, 266.l2 G. Bruhns, ibid., 1916, [ii], 93, 73, 312; A., 1916, ii, 337, 581,Is G.Bruhns, Chem. Zeit., 1917, 41, 189 ; A . , ii, 270.l4 G. Incze, Zeitsch. anal. Chem., 1917, 50, 177; A , , ii, 327.l5 J. H. Smith, J . SOC. Chem Ind., 1917, 36, 415; A., ii, 330ANALYTICAL CHEMISTRY. 163iurlicator, siiice it is more seiisitive to hydrogen ions. It showshllarp end-points with oxalic acid, alkali borates, and cyanides, butis unsuitable for sulphites. With carbonates and sulphides, it pro-duces intermediate colorations, and the titration must be con-tinued until a, bright pink t.int is obtained.16For the estimation of lime and magnesia in limestone, and forthe analysis of ammonium salts, thymolphthalein has been founda useful indicator, owing- to its not being sensitive to traces ofalkali, even in boiling solutions.17Further applications of differential iodometric methods have beendescribed.18 For the estimation of available oxygen in commercialpermanganate and other oxidised forms of manganese which coii-tain small amounts of iron, advantage is taken of the fact t h a tferric iron reacts so slowly with potassium iodide in phosphoricacid solution that it is possible by regulating the acidity of thesolution to estimate iodometrically the available oxygen before theferric iron reacts with the iodide.I9 The same principle may beused for the iodometric titration of.chromic acid in the presenceof ferric iron.20 I n the case of oxidised manganese ores contain-ing a large proportion of ferric iron, this method is not trust-worthy, but a suitable differential method of estimating the avail-able oxygen has been based on the facts t h a t on treating finelyground pyrolusite with hydrochloric acid and potassium iodide,liberation of iodine takes place; t h a t ferric chloride in acid solu-tion also liberates iodine, and that ferrous chloride is immediatelyoxidised by excess of iodine.21 I n another method of analysirigpyrolusite, the finely divided sample is treated with potassiumiodide, sodium phosphate, water, and phosphoric acid, and theliberated iodine titrated after about an hour.22 On the whole,however, the ferrous sulphate and direct iodometric methods givethe most trustworthy results in the evaluation of pyrolusite.23The red coloration which is sometimes produced in the iodo-metric titration of hydrogen sulphide IS probably due to hydro-lysis of the starch indicator to erythrodextrin.No effective meansl6 I?. Lehmnnn slid C,. Wolff, Arch. P h a ~ n . , 1917, 255, 113 ; A . ,l7 J. Moir, J. Chem. Met. and Miti. SOC. S . Ajricn, 1917, 17, 129 ; A . ,18 Compare Ann. Report, 1916, 186.l9 0. L. Barnebey and W. C. Hawes, J . Anlev. Cltem. SOC., 1017, 39, 607 :2o 0. L. Barnebey, ibicl., 604 ; A . , ii, 274.22 E. Rupp, Arch. Pharm., 1916, 254, 135; A . , i i , 390.23 0. L. Barnebey, J. Ind. Eng. Chern., 1917, 9, 961 ; A . , ii, 581.ii, 326.ii, 386.A . , ii, 274.0. L. Barnebey and G. M. Bishop, ibid., 1236 ; A . , ii, 390.a 164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of rendering the end-point of the reaction inore definite has beeiifound.24For the iodomeiric estimation of cadniiuiri in the presence ofzinc, a convenieiit though somewhat slow method is to remove thezinc by cryktallisat ion as sulphate.The solution containing thecadmium is then treated with hydrochloric acid and excess cffT/ 10-iodine, and the remaining iodine titrated with thiosulphate.25I n estimating magnesium by Stolba's method of titrating theprecipitate of magnesium ammonium phosphate with hydrochloricacid, it is essential that the solution should be neutral and thatthe amirioiiia should be added after the phosphats solution. Theforinatioii of the salt Mg3P0, is prevented by keeping the solu-tion just alkaline during the precipitation, and that of the saltMg(NH,),(PO,), by avoiding an excess of ammonium salts.Forthe accurate estiinatioii of niagnesiuin by precipitation asammonium magnesium arsenate and iodometric titration of theprecipitate, special precautions are also necessary. Thus a largeexcess of sodium arsenate must be used for the precipitation, whilstduring the titration of the liberated iodine the solution must bekept decidedly acid t o prevent a reverse action taking place. Thesolution must also be freed from ammonium salts.25I n another volumetric method, the magnesium is converted intomagnesium oxalate by means of oxalic acid, the excess of which istitrated with alkali solution.27The volumetric estiinatioii of chromium in ferrochroine by thesodium thiosulphate and potassium dichroinate methods is moreaccurate than by the permanganate method.With the latter, itis necessary to use the empirical value 0.3165 for chromium insteadof the theoretical value 0.310.2*A trustworthy method of estimating molybdenum has been basedon its reduction to Mo,O, by means of hydrochloric acid andamalgamated zinc, the reduced solution being received in a vesselcontaining a chilled solution of iodine chloride in hydrochloric acidand titrated with standard potassium iodate solution, This rapidlyoxidises the molybdenum t o Mo205, the further oxidation to NoO,being negligible provided thati care be taken to exclude directsunlight .2Q24 A. R'. Jagson and R. E. Oesper, J. Ind. Eng. Chem., 1917,9, 975 ; L4.,26 E. J. Ericson, ibid., 671 ; A., ii, 421.26 F.W. Bruckmiller, J. Amer. Chem. Soc., 1917, 39, 610; A . , ii, 271.27 N. Busvold, Chem. Zeit., 1917, 41, 4 2 ; A . , ii, 218.28 W. Herwig, Stahl. u. Eisen, 1916, 36, 6 4 6 ; A., ii, 104.2s G. 5. Jamieson, J. Amer. Chem. SOC., 1917, 39, 246; A , , ii, 275.ii, 577ANALYTICAL CHEMISTRY. 165Another volumetric method, particularly applicable to theestimation of molybdenum in steel, is to reduce the acidified filtratefrom the iron with standard titaiious chloride solution, the exce-ssof which is then titrated with standard ferric chloride. If thesolution does not contain more than about 0.05 gram5 per litre ofmolybdenum and inore than about 1 per cent. of hydrochloricacid, the oxide MOO, is quantitatively reduced to Mo,O,. I n likemanner, the vanadium oxide V,O, is reduced to V204.30The principal source of error iii the estimation of silica is thesolution of the precipitate in hydrochloric acid, the amount dis-solved varying with the proportion and strength of the acid, thetemperature, and the time of contact.The most' satisfactorymethod of dehydrating silica is to heat it for thirty minutes a t120° to 150°, and boiling the precipitate for three minutes with60 per cent. hydrochloric acid usually gives as pure a silica as isobtained by longer boiling or the use of more concentrated acid.3'The low results obtained in certain cases in the estimation ofiiitrogen by Kjeldahl's method when mercury is added during theacid treatment32 is due to the formation of mercury ammoniumcompounds, which are not' subsequently decomposed.This sourceof error may be obviated by using potmsium arsenite t o decomposethese cornp0unds.~3 For the estimation of nitrogen in nitrates andnitrites, the solution may be distilled with magnesium chloridesolution and a finely divided alloy of copper and magnesium,and the distillate collected in standard acid, the excess of whichis titrated as in Kjeldahl's method.34Under ordinary conditions, the precipitation of platinumsulphide is incomplete, owing to the formation of a stable colloidalsolution, but by the addition of magnesium chloride, the hydrosolis converted into an insoluble hydrogel. A method of estimatingi>latinum has been based on this fact, aiicl gives results in closeagreement with those obtained by electrolytic methods.35A rapid method of separating iron from lead has been basedon the insolubility of basic ferric nitrate, which is formed onevaporating the mixed salts with nitric acid and heating the resi-due a t 1000.36For the separation of iron from aluminium, advantage may beso Travers, Comnpt.rend., 1817, 165, 362; A., ii, 545.31 F. G. Hatvley, Eng. and 1Min. J . , 1917, 103, 541 : A., ii, 33-3.32 Compare Ann. Report, 1916, 187.33 E. Justin-Mueller, Bull. Sci. PhawmcoE., 1916, 23, 167 ; A . , ii, 39.34 T. Arnd, Zeitsch. angew. Chent., 1917, 30, i, 169 ; A . , ii, 504.3 5 V. N. Ivanov, J . Russ. Phys. Chem. SOC., 1916, 443, 5 2 7 ; A . , ii, 154,86 J. F. Sacher, Chem. Zeit., 1917, 41, 245 ; A . , ii, 245166 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.takeii of the fact t h a t ferric chloride is soluble in ether, whereashydrated aluminium chloride is insoluble in that' solvent.37The blue coloration formed when cobalt aminonium thiocyanatedissolves in ainyl alcohol has long been known as a sensitive testfor cobalt in nickel salts.It may also be used as a quantitativecolorimetric method under specified conditions as to the concentra-tion of the solutions, whilst by the addition of sodium pyrophos-phate the formation of ferric thiocyanate is prevented, and nofiltration is required .38When hydrogen peroxide acts 011 a cobalt salt in the presence ofammonium chloride and ammonia, it forms a cobaltic ammoniumsalt which can be precipitated by ammonium molybdate, whereasnickel under the same conditions remains in the protoxide coiidi-tion and is not precipitated by ammonium molybdate.On thesefacts, a new method of separating cobalt and nickel has been based.The presence of molybdate in the filtrate does not interfere withthe precipitation of nickel by the dimethylglyoxime method.39A satisfactory separation of nickel from copper may be effectedby means of dimethylglyoxime, the solution being treated withsufficient potassium sodium tartrate to keep the copper in solutionwhen the liquid is rendered alkaline for the precipitation of thenickel .4OVarious discordant statements have been published as to thesolubility of calcium carbonate in water. The discrepancy is dueto the slow dissociation of the carbonate by boiling water, with theloss of carbon dioxide.This dissociation and solution may be pre-vented by the addition of a small amount of sodium carbonate,and advantage may be taken of this in estimating calcium in theform of Carbonate. The precipitated carbonate is washed withboiling water containing a trace of sodium carbonate, is then dis-solved in standard hydrochloric acid, and the excess of acid titratedwith standard alkali hydroxide solution. The error due to sodiuincarbonate retained by the precipitate is negligible.41Elrc.tr.oc.hrr,ric.ctl ,1 trctlysis.The electroinetric method of ascertaining the end-points of reac-tions in volumetric analysis, which has been shown to give good37 S. Palltin, J . I/?<]. Ejzq.C h e / ~ . , 1017, 9, 951 ; A., i i , 581.3 R A. D. Powell, J . *Soc. C'hem. IlifJ., 1917. 36, 373 : A., i i , 220.n s A. Oarnot, COWIJ~. W H I ? . , 1917, 164, 807; A., ii, 391.4 0 T€. Grossnmnii n n t l J. Ri~lnnhcim, Zeif.cclr. r / u g e w . Cl/cn/., 191 7, 30,i , l,J!l; -4., ii, 512.A. Cavazzi, Gazsettcc, 1017, 47, ii, 49 ; A , , ii, 53:'ANALYTICAL CHEMISTRY. 167results in the estimation of vanadates42 and of vanadium andchromium in stee1,43 has now been utilised for other estimations.For example, in the titration of zinc with potassium ferrocyanide,advantage is taken of the difference of the E.M.F. of a platinumelectrode when immersed in a solution of potassium f errocyanideand in a solution of a zinc salt. The two electrodes (one ofplatinum wire and the other of calomel) are placed in the hot solu-tion of the zinc salt, which is then titrated with the ferrocyaiiidesolution until the pointer of the galvanometer, which, during thetitration, has been slowly deflected from zero in one direction,swings sharply in the other direction on the addition of one dropin excess of the reagent.If more than a trace of cadmium ispresent, it must be removed prior to the t i t r a t i ~ n . ~ ~The method may also be used for the estimation of certainbivalent metals in solutions of their sulphates. Barium hydroxideis preferable to sodium hydroxide for the titration, since it showsa much sharper end-point. Accurate results are thus obtained inthe estimation of copper, nickel, and cobalt, and the method mayalso be used for estimating magnesium in the presence of calcium,but is not applicable to cadmium, which appears to form a basichydroxysulphate.45Several methods have been devised in which substitutes are pro-vided for platinum electrodes. For example, tin may be estimatedin a hydrochloric acid solution of its salts by the use of a coppercathode and graphite anode,46 whilst a copper cathode and an anodeof passive iron may be used for the estimation and separation ofzinc and cadmium .47Platinum electrodes may also be replaced by silvered glass basiiis,a thin strip of platinum foil being bent over the edge of the basinto make the contact with the metal coating.Basins thus preparedmay be used for the electrolytic estimation of copper, cadmium,zinc, nickel, and cobalt.After use. the coating is removed withnitric acid, and the basins resilvered.48Another device to economise platinum has been adopted in amethod of estimating manganese, which is deposited as manganesedioxide, from a solution of manganous sulphate, in which is43 G. L. ICelIey and .J. B. Coiiant, J . Amer. Chem., SOC. 1916, 38, 311 ;43 G. L. Kelley and J. B. Conant, ibid., 719 ; A . , 1916, ii, 640.4 4 F. R. von Richowsky, J . Washington Acad. Sci., 1917,7, 141 ; A . , ii, 219.4 5 H. S. Hanied, J . .4mcr. C'heni. Soc., 1017, 34, 262 ; A . , i i , 272.4 6 T. Batuecas, AnaE. Pis. Q ~ i n t . , 1916, 14, 495 ; A., ii, 106.*' J. de Guzman Carrancio and P. Poch, ibid., 1917, 15, 236 ; A., ii, 509.4 8 J.Gewecke, Chem. Zeit., 1917, 41, 297; A . , ii, 334.*4., 1916, ii, 274.168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.immersed a rotat'ing anode of platinised glass. This is preparedby coating a tube of lead glass with a glycerol emulsion of chloro-platinic acid and heating the glass until it softens. The manganesedioxide is converted into manganous sulphate, which is dried a t450°, and weighed as the anhydrous ~ a l t . ~ QAn electrolytic method for the evaluation of iron sulphide hasbeen based on its decomposition with hydrochloric acid and zinc,and absorption of the evolved hydrogen sulphide in a solution ofcadmium chloride. The precipitat,e is dissolved in hydrochloricacid, the cadmium precipitated by sodium hydroxide, the cadmiumhydroxide dissolved in potassium cyanide solution, and the cadmiumelectrolytically estimated.The amount of sulphur correspondingwith the cadmium thus separated is about, 0.5 per cent. too low.60Water Analysis.For the removal of nitrites, the presence of which rendersWinkler's 61 method of estimating oxygen in water untrustworthy,various methods have been suggested.62 To these may be added amethod of treating the water with concentrated carbamide solutionand dilute sulphuric acid, the use of weaker solutions of the reagentcausing the results t o be too high. The trustworthiness cfWinkler's method is increased by using sodium hydrogen carbonatefor the conversion of the manganous hydroxide into manganous~arbonate.6~Winkler's method of estimating carbon dioxide in water bytitration with sodium carbonate solution54 has been shown t o beuntrustworthy,65 and its author has therefore recalculated thecorrection which must be applied to the results.56 Precipitation ofdissolved carbon dioxide or alkali hydrogen carbonate by means ofbarium hydroxide and titration of the excess of precipitant givesinaccurate results, owing to the precipitate containing occludedbarium hydroxide.I n the absence of magnesium salts, however,more trustworthy results may be obtained by titrating both liquidand precipitate together, using phenolphthalein as indicator.674 g F. A. Gooch and M. Kobayashi, Amer. J..Bci., 1917, [iv], 4.4, 53 ; A . ,ii, 426.H. Williams, Chem. News, 1917, 116, 1 3 ; A., ii, 425.61 L.W. Winkler, Zeitsch. anal. Chem., 1914, 58, 665; A . , 1915, ii, 277.68 Ann. Report, 116, 191.68 H. Noll, Zeitsch. angew. Chem., 1917, 30, i, 105 ; A . , ii, 602.I4 L. W. Winkler, ibid., 1914, 53, 746; A . , 1915, ii, 281.J. Tillmans and 0. Heublein, Zeitsch. Nahr. Genussm., 1917, 33, 281 ;L. W. Winkler, ibid., 1917, 33, 443; A . , i i , 423. A., ii, 332.IT' J. Tillmans and 0. Heublein, loc. cilANALYTICAL CHEMISTRY. 169The presence of carbon dioxide in excess of 28 parts per millioiirenders the results obtained by Blacher's method of estimatingliardness in water 5y i~nt'rust\Yorthy, but the aniount may be readilyreduced below that limit by aspiratioii. Sodium chloride in quanti-ties up to 2000 parts per million has no appreciable influence onthe results.It is essential, however, especially when the watercontains both calcium and magnesium salts, that in the final titra-tion the end-point should be taken when the phenolphthaleinbecomes intense pink, and not a t the first sign of coloration.59 Forascertaining the true neutralisation point of water, the use ofmethyl-red with a-naphtholphthalein gives more sensitive resultsthan the mixture of methyl-orange and phenolphthalein ordinarilyused as indicator. As little as 0.1 part of sulphuric acid or 0.2 partof calcium hydroxide in 100,000 parts of water may thus bed e t e c t e d .60The accuracy of the usual method of titrating chlorine in wateris increased by using a definite proportion of chromate solution(0-7 to 1 C.C. per 100 C.C. of water) as indicator. The presence offree acids, iron salts, or phosphates renders the method less sensitive,but borax has no influence on the results.61An indirect method of estimating strontium gives trustworthyresults provided that great care is taken to ensure the purity ofthe precipitates by reprecipitation. The weighed mixture of pureoxalates of calcium and strontium is dissolved in sulphuric acid,the solution titrated with standard permanganate solution, andthe proportion of strontium calculated from the results.61 Lithiumalso may be indirectly estimated by dissolving the mixed weighedchlorides of potassium, sodium, and lithium in water, and estim-ating the potassium and total chlorine in aliquot portions of thesolution. Prom these results, the data are obtained for calculatingthe amount of lithium.62The colorimetric method of estimating nitrates by means ofphenoldisulphonic acid is rapid, but involves several possible sourcesof error. For example, if chlorides are present, the addition ofsulphuric acid to the dry residue produces heat, which causeschlorine and nitric acid t o be liberated. This may be preventedby adding the sulphuric acid prior to evaporation of the mixtureto a small residue, but not to dryness. It is preferable that the5 8 C. Blacher, Y. Griiiiberg, and 31. Kissa, Chem. Zeit., 1913, 37, 56; A.,5 9 A. S. Behrman, Philippine J . Sci., 1916, 11, [A], 291 ; A., ii, 542.6o J. Moir, J . Chem. Met. and Min. SOC. S. Africa, 1917,17, 129 ; A., ii, 386.61 I. M. Kolthoff, Pharm. Weekblad, 1917, 54+, 612; A., ii, 379.S. D. Averitt, J . Ind. Eng. Chem., 1917, 9, 684; A., ii, 423.1913, ii, 153.Q170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.temperatmure during the evaporation should not exceed 70°, and ifthe proportion of chlorine is very high, evaporation underdiminished pressure is advisable. It is also essential for accurateresults that the proportion of nitrates to reagent should fall withindefinite limits.63 I n the case of waters rich in magnesium salts, at,urbidity due t o magnesium hydroxide is produced on neutralisingthe acid liquid. The addition of ammonium chloride will preventthis precipitation, but i f iron is also present, the neutralised liquidmust be filtered before making the colour comparison.64 A simplemethod of removing nit,ric acid from sulphuric acid for use in thistest is to shake the acid with mercury in a Lunge’s nitrometer.65C. AINSWORTH MITCHELL.83 W. F . Gericke, J . I n d . Eng. Chem., 1917, 9, 5 8 5 ; A., ii, 421.64 M . S . Nichols, ibid., 1917, 9, 186; A., ii, 421.65 H. D. Steenbergen, Ghern. IVeekblad, 1917, 14, 647 ; A . , ii, 421

ISSN:0365-6217    

DOI:10.1039/AR9171400146

出版商:RSC    

年代:1917

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.PROGRESS during the Fast year seems to have been made chiefiy oncertain special lines. I have dealt with some of these ratherfully, and have therefore grouped my remarks under comparativelyfew headings.The Alkaline Reserve of the Body.The myriad chemical reactions which in ths living body togetherconstitute ‘ metabolism ’ can progress normally only when certaingoneral conditions are steadily maintained. Normality of tempera-ture, osmotic pressure, and hydrion concentration in the fluids andtissues is essential to the normality of metabolism as a whole, andthe permissible range of variation is surprisingly small, especially inthe case of the factor last mentioned. The existence of mechanismst o secure, automatically, a fine adjustment in hydrion concentrationis a striking characteristic of the physiological machine.To ourknowledge of these physiological and chemical mechanisms the workof the last few years has brought new and satisfactory precision.The acquirement of this on the physiological side may be said tohave begun when it was shown how exceedingly sensitive is therespiratory centre to changes of carbon dioxide tension,l or, as verysoon became clear, to any change in hydrion concentration.2 Witheven the most minute increase in this there is stimulation of thecentre with a consequent increased elimination of carbon dioxidethrough the lungs, and so an ailtomatic return towards the normalI€, however, the lungs, as controlled by the respiratory centre, weresolely responsible for the regulation, the animal could certainly notdisplay the relatively equable rhythm of respiration which is charac-teristic of normal life.The sensitiveness of the kidney epitheliumto fluctuations in C, provides a second physiological regulatorymechanism which is constantly in action. The organ promptlyexcretes hydrions when they are in excess. Associated with theJ. S. Haldene and J. G . Priestley, J . Physiol., 1905, 32, 225 ; A . , 190.5,ii, 400.C. Liinsgaard, Biochem. J . , 1912, 41, 247.171 G* 172 ANNUAL REPORTS ON ‘rim PROC~RESS OF CHEMISTRY.physiological mechanisms are chemical means for regulation, a i dthese, in normal circumstances, are suacient to spare the formerfrom having t o deal with more than minor fluctuations. The buffersalts of the blood and the possibility of certaiii nietabolic readjust-iiients forin a first line of defence against gross changes of reactioii.Our knowledge with regard to these has recently gained greatly inclearness largely owing t o the work of L.J. Henderson 3 and t o theresearches which ’his writings have stimulated. The chemical deter-minants of hydrion equilibrium in the blood are the carbonates, thephosphates, and the proteins contained in it. Henderson has madei t clear that of these the carbonates play by far the most importantpart; in the plasma, indeed, almost an exclusive part. An aqueoussolution of about 0*12L’\’-sodium liyarogen carbonate exposed to aproper tension of carbon dioxide will, in respect to the changes inC, produced by adding varying amounts of acid, serve as a simplemodel of the plasma.4 A determination in the plasma of the ratioH,CO,/NaHCO, may, as Hasselbalch 5 has shown, give even a bettermeasure of the C, than any obtained by the gas-chain method.Intimately related to the actual hydrion concentration, but requir-ing separate consideration, is the “ alkaline reserve ” of the bloodand tissues.Any appreciable change in the former only OCCLWS inthe blood under conditions of extreme abnormality, but two indi-viduals displaying a t any moment a normal blood reaction, and boththerefore free from the symptoms which follow on a disturbance inthat reaction, may yet be in very different metabolic positions. I none the alkaline reserve may be untouched and normal; in theother it may be near exhaustion and the individual in danger.“ Free carbonic acid is present in the body fluids in such concen-tration that i t automatically converts into bicarbonate all bases notbound by other acids.T h e bicarbonate therefore represents tJreexcess of base which is left after all the non-volatile acids have beenneu tralised, and is available for the immediate neutralisation offurther ecids. I n this sense i t constitutes the ulkaline reserceof tJbe body. The bicarbonate concentration of the blood is repre-sentative of that of the body fluids in general, and is normally main-tained a t a definite level. Entrance of free acids reduces it t o anextent proportional to the amount of the invading acid.” It isfound that plasma obtained by drawing blood from a vein of thearm contains a t 3 7 O and normal carbon dioxide tension approxi-mately 60 vols.per cent. of carbon dioxide bound as bicarbonate.Compare J . Biol. Chem., 1911,9, 403 ; A . , 1911, ii, 752. Ergebn. Physiol.1909, 8, 254.K. A. Hasselbalch, Biochem. Zeitsch., 1916, 78, 112 ; A . , i,490.Not of the blood, as implied by Michaelis (“Die Wasserstoffionen-Koncentration, Berlin, 1914)PHYSIOLOGICAL CHEMISTRY. 173This nleaiis that, with the average tension in arterial blood(43 nim.), the ratio of unbound t o bound carbon dioxide (H,CO,/NaHCO,) = 1 / 20. I f abnormal quantities of acid enter the blood,the organism is able, until a large part of its bicarbonate reservehas become exhanst,ed, t o maintain by accelerated respiration theabove ratio a t its normal value.The C,, being, as we have seen,proportional to this ratio, also remains normal.It is clear that quantitative knowledge concerning the availablebicarbonates is desirable both- in physiology and pathology. Iiiipor-taiit contributions to the technique of estimations and a number ofvaluable data have been published during the year from the Rocke-feller Institute f o r Medical Research in a series of papers by D. n.vaii Slyke and his co-workers. 111 a prelinlinary paper,R froin which'I have already quoted, the considerations briefly slretclied above arefully and clearly dealt with. Various methods which have hithertobeen used for the detection of acidosis are reviewed and shown tobe essentially means, sometimes rough or approximate, for the esti-mation of bicarbonates. Much experimental work is also describeddealing with points which needed investigation before the methoddescribed in the second paper7 could be critically applied to theproblem.I n this method a special form of apparatus is used whichpermits of an estimation of bound and unbound carbon dioxideon very small quantities of blood, such as can be withdrawn withoutinconvenience from human subjects. The apparatus is essentiallysimple, and its description is likely t o stimulate in the immediatefuture valuable work from the hands of many observers. Illustrat-ing the present tendency in biochemistry t o strive after accuratemicro-analytical methods is the further description of a modificationof the apparatus which measures within one volume per cent. thesmall amount of carbon dioxide (0.1-0.15 c.c.) contained in 0.2 C.C.of blood plasma, a quantity which can be obtained on pricking thefinger.Technical points which arise in connexion with the use cfeither form of apparatus are fully discvssed, and tables are sup-plied whicli simplify the calculations.The ideal method for determining the alkaline reserve is t o esti-inate the bicarbonate in arterial blood when exposed t o the parti-cular tension of carbon dioxide actually existing in the vessels ofthe subject or pat.ient, as measured, for instance, by the alveolartension in his lungs. I n routine work i t is sufficient to use theeasier experimental conditions offered by the use of venous bloodpreviously exposed (in apparatus described in the paper) to theD.D. van Slyke and G. E. Cullen, J . BioE. Chem., 1917, 30, 289 ; A . ,D. D. van Slyke, ibid., 30, 347 ; A , , ii, 422.i , 521174 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.normal mean tension. The results are equally definite in theirsignificance.The third paper 8 in the series under review deals with the electro-metric titration of plasma as a method of measuring its alkalinereserve. This can be carried out on much snialler quantities of bloodtlian ordinary titration would require, and gives much sharper end-points. The well-known gas-chain method with calomel cells wasused, every precaution being taken t o secure the highest grade ofaccuracy.A definite amount of standard acid was added t o ameasured volume of plasma on the assumption that the resultantchange in C, will be greater the less the alkaline reserve. Since theinitial reaction of all plasmas is practically constant, and since, asdirect observations showed, the curve of titration got by addingsuccessive amounts of acid is almost a straight line, the claim ismade that i t is possible to condruct a curve from one determina-tion, and from i t to determine the amount of acid required to bringthe plasma t o any desired reaction. To obtain comparable resultsi t is necessary to bring all samples to a definite carbon dioxidecontent. Two procedures were adopted: the plasma was eitherfirst shaken with a known volume of air and an equal volume ofN /50-hydrochloric acid then added, or of acid sufficient t o liberateall the carbon dioxide from the carbonate (two volumes of N/50)was first added and the carbon dioxide then removed.I n each casethe acidified plasma was transferred to a Clark electrode and theresultant C, determined. The results obtained by the two methodswere, of course, not identical, but they were found to run parallelunder varying conditions. Experiment showed that the hydrogenexponent (Sorensen) of plasma when mixed with 1 volume of N/50-acid becomes, in the case of normal human blood, 7.00. When twovoiumes of N/50-acid are added i t becomes 5.6. These are averagefigures, certain fluctuations occurring during the day.I n extremecases of diminished alkaline reserve exponents were obtained as lowas 5.7 after the addition of one volume of acid, and of about 4.8after adding two volumes.The renal mechanism is, as I have already pointed out., continu-ously concerned with the adjustment of PIT in the blood, It is ofgreat interest, therefore, t o know how far quantitative relationscan be shown t o exist between the production of acid in metabolisinand the rate of excretion of hydrogen ions, or, in other terms,between the existing alkaline reserve and the contemporary excre-tion of acid.I n last year’s Report the formula of Anibard and Weil wasbriefly discussed. This empirical formula professes t o relate theG. E. Cullen, J . Biol.Chem., 1917, 30, 369; A., i, 521PHYSIOLOGICAL CHEMISTRY. 175coucentration of eubstances in the circulation with their concentra-tioil in the urine and with the rate of their elimination. With somereservations it may be said to hold satisfactorily in the case of ureaand chlorides. Does it obtain in the case of acids? I n the fourthpaper9 of the series under review we are given experimental evi-dence which suggests that i t does.Ambard and Weil's formula may be put in the form Cb=A x~ D / w J ~ ~ , where Cb is the concentration of the substance in thebhod above the excretion threshold, Cq6 its concentration in theurine, and D the rate of its excretion; and u) is the body weight.Before any attempt to decide as to how far acid excretion followsthis law, certain considerations must be borne in mind.I n the firstplace a great part of whatever acid is produced in metabolism inexcess of available mineral bases is neutralised by ammonia. I n thesecond place i t must be noted that C b in the above equation refersto concentration in excess of a certain threshold value, and in thecase of acid we need some definition for this value. Experimentsshow that the acidity of urine titrated (by Folin's method) withphenolphthalein as indicator, approaches zero when the concentra-tion of the blood bicarbonate corresponds with 80 volumes per cent.of carbon dioxide. I n these circumstances the excretion of ani-monia also approaches zero.I n applying Ambard's formula to the excretion of acid, D wastherefore made t o represent the rate of excretion of N/lO-acid, plusammonia, for a twenty-four hour time unit, and Cu became thenumber of C.C.of N/lO-acid, plus ammonia, per litre of urine. Onth: assumption that acid accumulation in the blood is proportionalto the fall in carbon dioxide below 80 vols. per cent., the relationbetween the blood accumulation and acid excretion becomes :- -- Retained acid = 80 - observed CO, of plasma =constant x d D / w . dCl7The constant proved. t o be unity, so we have:Plasma CO, capacity = 80 - J D jw 2 Clr.It should be understood that the formula, although suggested bythe researches: of Ambard and Weil, is wholly empirical, and wasemployed solely because no other expression fitted the experimentalresults EO well.The margin of error found, when results calcu-lated from the formula were compared with direct determinationsof the carbon dioxide bound in plasma, was about 10 volumes percent. Of thirteen observations made on normal individuals, someof whom were given bicarbonate by the mouth, eight showed anerror of less than four volumes per cent. The average of the deter-s R. Fitz and D. D. van Slyke, J . BioZ. Chem., 1917, 30, 389, A . , i, 522176 ANNUAL REPORTS OX THE PROGRESS OF CHEMISTRY.minations was 71.3 C.C. of carbon dioxide per 100 C.C. plasma, theaverage of the calculated results was 71.6.In a fifth paper10 figures are given f o r the quantitative relationwhich obtains between the alveolar carbon dioxide tension and theco-existing plasma bicarbonate.The former was determined byFredericia’s modification of Haldane’s method, and the latter byvan Slyke’s method as described above. The range of plasmacarbon dioxide was found t o be between 53 and 75 C.C. bound asbicarbonate. Gettler and Baker,” using essentially the samemethod, found the range in thirty individuals to be between 56 and78 C.C. The. extreme range for normal adults may now be lookedon as established, being from 53 to 78 C.C. The ratio-plasmaCO,/mm. alveolar C0,-varies from 1-27 to 1.80, the average valuebeing about 1.5. Approximate information as to the existing alka-line reserve may be obtained therefore by multiplying the observedalveolar tension by the latter figure. The variations must not beforgotten, however.It has been found that digestive activitycauses a rise in alveolar carbon dioxide tension, and the fact hasbeen explained on the one hand l2 as being due to an increase in thereserve alkali of the blood, caused by the secretion of hydrochloricacid in the gastric juice; on the other hand,l3 as a change in theirritability of the respiratory centre. The occurrence of this rise isconfirmed in the present research, and the experiments describedfavour on the whole the latter explanation.The main purpose of the wries of researches just discussed wasto make i t possible to determine the relationship of the blood bicar-bonate as directly estimated to that estimated indirectly from theexcretions of the lungs and kidneys. The sixth and last paper14describes the application of the various methods to a number ofcases of diabetes.The indications given by the methods were thuscompared, whilst data were obtained as t o the relationship of plasmabicarbonate deficiency to the clinical severity of acidosis. I n twenty-one cases the alveolar tension of carbon dioxide, the bicarbonateof the whole blood and of the plasma, the hydrogen-ion concentra-tion, and the index of acid excretion were all determined. Curvesare given in the paper which show the variation in these factorsfrom day to day. On the whole, the curves are remarkably parallel.The alveolar tension in diabetic patients under treatment is, how-lo D. D. van Slyke, E. Stillman, and G. E. Cullen, J . BioZ. Chena., 1917, 30,401 ; A ., i, 523.l1 A. 0. Gettler and W. Baker, ibid., 1916, 25, 211 ; A., 1916, i, 576.l2 H. Erdt, Deutsch. Arch. KZin. Med., 1915, 47, 497.l3 H. L. Higgins, Amer. J . Physiol., 1914, 24, 114 ; A . , 1914, i, 613.l4 E. Stdlman, D. D. van Slyke, G. E. Cullen,and R. Fitz, J . Biol. Chern.,1917,30, 405 ; A,, i, 523PHYSIOLOGICAL CHEMISTRY. 177ever, often much too low to indicate the true level of the bloodbicarbonate, although in severe acidosis this discrepancy disappears.On the other hand, the consistent agreement of the figures forplasma carbon dioxide directly determined and those calculated asabove from the index of acid excretion by the kidney is striking,and certainly very ifiteresting. Only when bicarbonate is beinggiven by the mouth or when the acidosis is very severe, does thisagreement fail. Of the two indirect measures of alkaline reservethat given by the lungs appears to be more trustworthy when thereserve is very low and coma threatened, whilst that given by thekidney is to be preferred in the more common intermediate stages.The results point to the following relations between the degree ofacidosis and the bound carbon dioxide in 100 C.C.of the plasma:normal adult, 77-53 ; mild acidosis, 53-40 ; moderate acidosis,40-30 ; severe acidosis with definite syiiiptonis of acid intoxication,below 30. The lowest volume of plasma carbon dioxide recorded inwhich recovery occurred is 16. It may be noted that, as pointedoiit. in the first paper of the series, there is at present confusion in theliterature with respect to the term acidosis. Different authors regardacidosis as ‘’ acid intoxication,” as a condition in which acetonesubstances are formed, or as an actual increase in the hyclrogeii-ion concentration iii the blood.I t is here defined as a c>onditioiiin which the concentration of bicarbonate in the blood is reduceJbelow the normal level. In cases where C, is actually increased, theterm “ uncompensated acidosis ’’ has already been employed. It isnow proposed t o speak of “ compensated acidosis ” when, despitedecreased bicarbonate, the respiratory mechanism succeeds in keep-ing the ratio H,C03/NaHC03, and therefore the C,, within norma1limits.A special form of apparatus for gas analysis also applicable tothe determination on small amounts of material of the free andcombined carbon dioxide in blood or serum has been described byY.Henderson and W. H. Morriss.15 Their paper contains valuesobtained from the blood of patients in the gynaecological wards ofthe Yale School of Medicine. Van Slyke’s method was comparedwith that of the author’s, and the results were consistent. J. F.McClendon 16 and his co-workers have published diagrams by meansof which the alkaline reserve may be ascertained when either thealveolar carbon dioxide tension, ths total carbon dioxide of theserum, or its C, under known tensions of carbon dioxide has beendetermined.l 5 J . Biol, Chem., 1917, 31, 217; A., ii, 506.J. F. McClendon, 4. Shedlov, and W. Thomaon, ibid., 1917, 31, 519 ;A., i, 671178 ANNUAL REPORI'S ON THE PROGRESS OF CHEMISTRY.It will have been noticed that the researches described in theforegoing paragraphs have for the most part been carried out withplasma or serum and not with t'he whole blood.The use of eitherof the two former adds greatly to the ease of estimations, andthere would seem to be sufficient evidence to show that the plasmabicarbonate is a real index of the alkaline reserve of the &oleblood and of the tissues. It is an index because there exists anacid-base equilibrium between corpuscles and plasma and betweenblood and tissues, which on the occurrence of any change is rapidlyreadjusted.Moreover, when we speak of the reaction of the blood we refer,strictly speaking, to the reaction of its plasma.It is this whichis measured by an electrode immersed in the whole blood; thecorpuscles merely remain suspended indifferently in the fluid, aridmay be removed without altering the E.M.F. reading. Doubt-less, moreover, i t is the reaction of the plasma which comes intodirect' contact with the tissues that is of importance physiologically.When corpuscles and plasma are in equilibrium under any givenconditions, the removal of the former will produce no change inthe ionic equilibrium provided that the conditions remain un-changed. Towards a change of conditions, however-of carbondioxide tension, for example-the separated plasma will behavedifferently from the whole blood, because the corpuscles play soconsiderable a part in determining the equilibrium condition.17To understand the behaviour of the whole blood when, forinstance, carbon dioxide or other acids enter it as they arise inmetabolism, we must take account of the corpuscles.We must doso, indeed, if we are considering the actual alkaline reserves of theblood.It was long ago shown18 that with increasing carbon dioxidetension, hydrogen chloride (or rather the chlorine ion) leaves theplasma for the corpuscles; and a recent paper19 contains evidenceto show that the SO, ion does the same. Apparently under thesame conditions, potassium and sodium also leave the corpuscles.Thus increasing tension of carbon dioxide increases the alkalinityof the plasma, and reverse changes follow with diminishing tension.Hasselbalch20 has directly shown that the P, of the whole blood,that is, of the plasma in contact with corpuscles (see above), changesmuch less with changes of tension in carbon dioxide than does thatof plasma, serum, or simple solutioiis of bicarbonate.Hasselbalchl7 Compare T. K. Parsons, J . Physiol., 1917, 51, 440.la Gurber, Sitzungsber. physik. med. Ges. Wurzburg, 1896, 21.l9 S. de Boer, J . Physiol., 1917, 51, 211 ; A., i, 671.2o K. A. Hasselbalch, Biochem. Zeilsch., 1916, 78, 112 ; A . , i, 490PHYSIOLOGICAL CHEMISTRY. 179does not attribute this simply to the influence of the corpuscles asrepresenting a separate phase across the surface of wnich ionic iater-changes occur, or to the xeal, if minor, influence of the phosphateswit,hin the corpuscles, but rather to the special influence of oxy-hzemoglobin as an ampholyte.This substance becomes the moreacid the more alkaline the reaction of its milieu. It acts as bufferto a degree of which the plasma proteins are incapable and pro-motes decomposition of bicarbonates during diminishing tensions ofcarbon dioxide. The properties of haemoglobin in this conliexionare of physiological importance, since, when the blood is taking upcarbon dioxide from the tissues, the oxyhzmoglobin becomesreduced, and reduced hzeinoglobin is less acidic.As a result of observations involving ingenious technique a i dmade partly in continuance of interrupted work by R. A. Peters.T. R. Parsons 2 1 ~ ~ has shown that the of fully oxygenated bloodat a given tension of carbon dioxide is less than that of completelyreduced blood by 0.038, and that the difference between arterialand venous blood is approximately 0.02.The effect of oxygen inexpelling carbon dioxide from the blood is due to the increase ofacidity it produces. The author claims that changes in the relativenumber of corpuscles to the extent actually observed in patho-logical conditions exerts an appreciable effect on the reaction ofthe blood in the body, and so on the respiratory equilibrium.Some Aspects of Sictrition.The present shortage in the food supply of the world makesiniportant every detail of knowledge concerning human nitrition .Even facts which seem academic need scrutiny, in case a t somepoint or other they may find application in the direction ofguidance for economy.I n the present section I shall considertogether, without much regard t o order, the results of a numberof recent researches into various aspects' of nutrition.Particularly desirable just now is any scrap of knowledge con-cerning the cereals. Except in arctic climates, bread and cerealsare always important items in the food of mankind, and exceptwhere wealth has accumulated and luxury come in its train, theyare by far the most' important. Circumstances have to be veryexceptional indeed when the growing of cereals does not yield anenergy supply for the worker at less cost and with less relativeeffort than any other method of food production. Economic andsocial factors usually tend to make bread by far the most con-venient form in which the cereals can reach the individual consumer.21" L O C , cit180 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The nations of the West have acquired the habit of demandinga well-piled loaf, and for this the special properties of wheat glutenseem necessary.Hence the reliance on wheat in the West. Yeti t has been calculated that, after all, no more than a fourth ofmankind relies on wheat, and when a relative shortage in thiscereal renders it desirable that other cereals should accompany itin bread, the consequences should not be prejudged.Experiments on animals show, indeed, that wheat when coiii-pared with other grains has no outstanding merits as a nutrient.No cereal forms a perfectly balanced food when eaten to theexclusion of everything else; but except of milk, and of that onlyas a food for infants, the same may be said of every other individualfoodstuff.I n countries like Australia, where wheat is especiallyabundant, efforts to use i t instead of oats for working horses, andto employ i t largely in the raising of stock, have resulted inrelative failure. A ration wholly from the wheat plant-grain plusstraw-when fed to heifers has been shown to be entirely in-adequate for reproduction, and in some instances even for continuedgrowth .21Pigs when given wheat alone, even although certain mineraldeficiencies in the grain are made good, soon cease to grow anddevelop pathological symptoms, proving wheat, in this particularcase, to be inferior to maize.22 To remedy completely the defici-encies displayed, i t would seem that not only must the balance inmineral salts be improved and accessory factors of the vitaminetype be increased in amount, but the protein of the grain mustbe improved by the addition of other proteins.It is claimed thatpart of the symptoms displayed by animals on an exclusive wheatdietary containing the whole grain are due to a toxic factor.23 Iam not quite sure that the evidence for this view is yet sufficient.Still further observations of a quantitative sort involving theadjustment of deficiencies seem first called for. Nevertheless, anoil with definitely toxic properties has been extracted from thewheat embryo.It may be noted that some inherent deficiency in a diet maynot be fully disclosed until animals fed 011 it are allowed tobreed.Complete failure to rear young may characterise ailabnormal state of nutrition which is not obvious in the parent21 E, B. Hart, E. V. McCollum, and G. C. Humphrey, Exp. Stut. Research22 E. B. Hart, and E. V. McCollum, J . Riol. Chem., 1914, 19, 373; A . ,23 E. B. Hart, W. 8. Miller, and E. V. McCollum, ibid., 1916, 25, 239;Bull., 17 (1911).1914, i, 620.A., 1916, i, 681PHYSIOLOGICAL CHEMISTRY. 181animal itself. This failure seems t o be generally exhibited byanimals on ail exclusive wheat diet .24Agriculturists have long recogiiised the illadequacy of maize asa sole diet for animals. This inadequacy is due to various causes.When i t is fed to working horses, the effect of a relative excess ofcarbohydrate and deficiency of total protein makes itself felt.I nthe case of growing animals, mineral deficiency and errors in theamino-acid balance of its proteins have to be recognised. Recentresearches have given us a more accurate analysis of these variousdeficiencies. Apparently, whilst one of them is the more importantto one kind of animal, another may be of greater moment to anotherspecies. For example, the mineral deficiencies of maize aretolerated much better 6y pigs than by rats; its protein deficiencies,011 the other hand, are borne more readily by the latter.Z5 Suchdifferences, however, are only relative. Pigs, for instance, when fedon maize-meal, fortified by the addition of extra proteins derivedfrom maize itself, showed little or no growth, but when suitablesalts were added, approximately normal growth was observed.26Nevertheless, on this diet perfectly normal reproduction couldnever be obtained.Young were born, but the mother failed torear them.27 Maize, like other grains, is quantitatively deficientin a factor to which I shall later make further reference, the sub-stance called “ f a t soluble A ” by McCollum. Animals thrivebetter 011 maize diet when an extra supply of this is given innatural butter or in the form of an alcoholic extract derived frommaize itself. Some particularly interesting data concerning maizeas a foodstuff have been published by A. G. Hogan,Zs His experi-ments confirm the generally accepted view that the chief mineraldeficiency is one of calcium.The low nutritive value of theproteins is shown strikingly in experiments with pigs. Thus oneset of animals of which the protein supply was wholly in themaize showed an average gain in weight, in 780 days, of only5 kilos. Another set of which the diet was the same but for asmall addition of casein (1.22 per cent’. of the whole ration andabout 10 per cent. of the whole protein) gained in the same timean average of 81 kilos. The vast superiority of casein as a proteinfor growth is obvious. The nature of the deficiency in the proteinwas brought out in experiments on rats. These experiments,2 4 E. V. hIcCollum, N. Simmonds, and W. Pitz, J. Biol. Chem., 1916, 28,Hart, McCollum, and Humphrey, Zoc.cit.25 A. G. Hogan, J. Biol. Chem., 1916,29,193 ; A., 1916, i, 861.O6 E. B. Hart and E. V. McCollum, ibid., 1914, 19, 373 ; A., 1915, i, 39. *’ E. V. McCollum, N. Simmonds, and W. Pitz, ibid., 1916, 28, 153; A . ,211 ; A., i, 184.i, 192. 2a J . Bio2. Chem., 1917, 29, 485 ; A . , i, 363182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.whilst chiefly confirmatory of previous work by others, gave par-ticularly clear results. The whole proteins of maize, and zein alone,were supplied iu the basal dietary. On this diet the animals werenot maintained. The additioii of lysine alone led t o no iinprove-ment, but added tryptophan greatly iinproved the condition.When both these amino-acids were added, health and growthbecame normal.Tryptophan, theref ore, is the first limiting factorin the nutritive value of maize protleins, but when this is supplied,lysine proves to be a second limiting factor.It, seems probable that in the case of oats the nutrient factorsare, from the point of view of the animal, better balanced than isthe case in either wheat or maize. Many observers, i t is true, havereported failure in attempting to keep animals in health on oatsalone. I n the case of rabbits, the symptoms which appear havebeen ascribed to simple acidosis, as they are prevented by theadministration of sodium hydrogen ~arbonate.~g This observationhas been recently confirmed .30 In guinea-pigs, however, a moreserious condition develops, for, as is well known from the originalexperiments of I-Iolst and Frohlich,3I an exclusive oat diet, no lessthan one coiisistiiig solely of other grains, induces symptoms in theseanimals which are indistinguishable from those of scurvy.Theseanimals placed 011 a grain dietary have been much used, tharefore,to demonstrate the presence of anti-scorbutic factors in various food-stuffs. The results obtained, both in the way of prevention andof cure, have seemed striking enough. Doubt, however, has beenrecently thrown on the view that scurvy is really a “deficiencydisease.” E. V. McCollum and W. Pit232 claim to have shown thatthe symptoms, in the guinea-pig at any rate, are due, not to theabsence of an anti-scorbutic vit’amine, but simply to a retention ofmaterial in the cxcum, owing to the unfavourable physicalcharacter of the diet.This leads to bacterial poisoning. Thesymptoms, according t o these authors, can be prevented by theadministration of substances which depress the growth of micro-organisms in the digestive tract or which facilitate the eliminationof the faeces. I have read their paper without being convincedthat their case is established. The experimental results are veryirregular, and in this respect, unlike those obtained by others whohave used fresh vegetables or fruit’ juices for prevention or cure.3329 A. Morgen and C . Beger, Zeitsch. physiol. Chem., 1916, 94, 324 ; A .30 C. Funk, J . Biol. Chem., 1916, 81, 229 ; A., i, 696.31 J . Hygiene, 1907, 7 , 034.32 J . Biol. Chem., 1917, 81, 229; A ., i, 004.33 A. Holst, J. Hygiene, 7, 619 ; Harriette Chick and Margaret Hume,1915, i, 922.Tmnn. h’oc. Trop. Med. ccnd Hygiene, 1917, 10, (8), 141PHYSIOLOQICBL CHEMISTRY. 183It is very hard t o believe, inoreover, that the remarkable appear-ance of aiiti-scorbutic power in grains and seeds at the moment ofgermination could depend 011 ail acquirement of laxative orelimillative propert ies.34 Nevertheless, the observations ofMcCollum and Pitz must be carefully borne in mind in any futurework on this subject. Fuiik,3j strange to say, has found that' theguinea-pig, when on an oat diet, is but little protected by theadministration of anti-scorbutics ; the only fresh products he used,however, were milk and potato juice. He found the former t o bethe more efficacious of the two, a result which does not agree withthe observations of others.36Reviewing what has been said of the variow cereals, it will, Ithink, be admitted that what we know of their nutritive propertiesfrom animal experiments does not suggest that wheat takes anypre-eminent position.As any one of the cereals proves when eatenalone to make an ill-balanced dietary, it is likely that admixtureof two or more may actually improve the balance of nutritiveelements in bread.Another question arises in connexion with grain foods which isof great practical importance a t the present time. What is theeffect of increasing the percentage extraction of grain 011 thenutritive value of flour and bread? Do we gain by such anincrease, or does the small digestibility of the added fraction nullifysuch gain? I need only refer to the report of the Royal SocietyFood (War) Committee on this subject.Careful and sufficientlyprolonged digestibility experiments on twelve individuals, com-paring a bread made from wheat flour of approximately 80 percent. extraction with one made from 90 per cent. flour, showed, inspite of a slightly lessened digestibility, a marked gain in actualnutriment when the latter was employed-a gain in availableenergy equal to something like a month's supply of cereal food forthe nation. An interesting point shown by these experiments isthe great uniformity displayed by individuals in the power ofdigesting a dietary. Of the total calories contained in the dietcomprising the 80 per cent.bread, 96-14 per cent. were on theaverage digested. The extreme departures from this were 95.1 percent. in one case and 96.96 in another. The average agrees closely,moreover, with that obtained in experiments made a t Cambridgesome years ago with four quite different individuals.37 On aClOSelY similar but not identical bread, the calories digested wereFbt, Zeitsch. Hygiene, 1912, 72, 121.36 c. Funk, J . Bid. Chem., 1916, 25, 409 ; A . , 1916, i , 696.'* H. Chick and M. Hume, ZOC. cit.97 J. Hygiene, 1912, 12, No. 2, 110184 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.97.27 per cent. of the whole. I n the Royal Society’s experiuLauts,the diet containing bread made from the flour of higher extrac-tion showed on the average a digestibility (in respect of its calories)of 94.5 per cent,.Such figures show how little basis has the ilotuncommon belief that even the present-day Government regulationflour (80 per cent.) has qualities which lead to a serious wastage ofits food value.Miss Harriette Chick and Miss Margaret Hume have, in verythorough experiments, studied the precise distribution of the anti-neuritic vitamine in the grains of wheat, rice, and maize. Pigeonswere fed on a basal daily ration of about 2.6 grams of polishedrice. On this alone the birds usually develop symptoms of neuritisin from fift’een t o twenty-five days. The various parts of the grainwere tested either as preventitives, when they were added to therice from the beginning of the experiment, or as curative agentsby administration after the symptoms had developed.It wasfound that in all the grains the vitamine is concentrated mainly inthe germ or embryo, and that it is present to a less degree in thebran (pericarp and aleurone layer), probably mor0 particularly inthe aleurone layer.As the subject of vitamine has received a good deal of attentionin recent Reports, I had, as a matter of fact, intended to omit ithere, thinking further reference to i t might await the arrival ofreal knowledge as to the nature of these substances. The work ofthe year has rather forced my hand, however.Itl was to be expected that conceptions new and foreign to viewslong held would have to submit to a period of criticism.I havejust dealt with doubts thrown on the hypothesis of anti-scorbuticvitamines, although these doubts proceed from authors who stronglybelieve (and whose own work deeply commits them to the belief) inthe part played by vitamines when growth and the maintenance ofgeneral nutrition are in question.F. Rohmann,38 however, has lately published in Germany abrochure in which the importance of such factors is repudiated.This publication I have myself been unable t o obtain, but it isquoted and dealt with in a recent paper by Osborne and MendeL39Rohmann asserts that “accessory foodstuffs are, a t any rate, notnecessary for the continued maintenance of f ull-grown animals.”I n this he inay be right if by ‘‘ continued maintenance” he meansmaintenance for somewhat long, although by no means indefinitePeriods.He goes further, however, and expresses the belief that** F. Rohmann, ‘‘ Ueber Kiinstliche Ernahrung und Vitamine,” Berlin,1916.3D T. B. Osborne and L. B. Mendel, J . BioE. Cheln., 1917, 31, 149 ; A.,i, 603PHYSIOLOGICAL CHEMISTRY. 185the long familiar factors of energy, protein, salts, etc., if properlyadjusted, suffice for the growth of the young animal and for allpurposes. Osboriie and Mendel, in the paper referred to, havecriticised the comparatively few experiments on which Rohmannapparently relies for proof t h a t animals (mice) can grow andultimately produce young on pure synthetic dietaries. The foodpreparations used seem t o offer quite insufficient guarantees t h a tvitamilles were absent from them.For my part, I am convincedfrom a careful re-perusal of all the published evidence, as well asfrom my own experiments, that the existence of factors of un-known nature, present in most natural foodstuffs, essential togrowth, and active in very small concentration, is now proved. Asto how they exert their effect, whether by directly stimulating thegrowing tissues, or, as is possible, along lines much more indirect,we are wholly ignorant. I have said that the vitamines are sub-stances of unknown nature, b u t if one return for a moment to theanti-neuritic agent or agents (which are not necessarily the sameas the growth factors), reference should, I think, be made t o thetruly remarkable statements of R.R. Williams. This author hasfound that certain pyridine derivations exist in two isomeric formsof different stability. I n t h e case of 2-hydroxypyridine, forinstance, there is an unstable form crystallising in needles and astable form crystallising differently. Now the first' form (whichhas probably a betaine structure), but not the second, is said tohave a powerful and rapid influence in curing birds which havedeveloped neuritis after polished rice feeding. Analogous facts, itis claimed, hold with other pyridine derivations, as, for instance,nicotinic acid. I find it somewhat hard t o believe that we havehere disclosed the actual nature of anti-neuritic substances as wefind them in natural foodstuffs; but. even if the author has madea pharmacological rather than a physiological discovery, it is nonethe less a remarkable one.Unfortunately, however, the firstattempt t o repeat the observations has failed.40Owing to the initial work of McCollum and Davis,41 belief isbecoming established in the existence of two substances each ofwhich is essential to growth; of these, one is soluble in water andthe other is soluble more particularly in fats. McCollum alldKennedy,42 feeling that the name vitamine, due to Funk, connotes40 A. Harden and S. S. Zilva, Biocitem. J., 1917, 11, 172 : A . , i, 612.41 E. V. McCollum and M. Davis, J . Biol. C'hent., 1916, 23, 181, 251 ; A . ,42 E. V. McCollum and C. Kennedy, J. Biol. Chem., 1916, 24, 491 ; A . ,See for the most recent contributions to this subject, J .B i d .The paper appeared too late for treatment in1916, i , 184.1916, ii, 451.Chem., 1917, 32, 309 and 347.the text186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.more than it should, and holding t h a t the term "accessory foodsubstances " as originally used by myself is too indefinite, proposeto give to these two substances of unknown nature the 11011-com-mittal labels '' fat-soluble A " and '( water-soluble B " respectively.I n coiiiiexioii with this point", the practical question has arisenas to how far the various brands of margarine on the market sufferfrom a deficiency in the fat-soluble substance which is abundantlypresent in butter. W. D. Halliburton and J . C. Drumrnond43 havecarried out, a valuable pioneer research on this subject.Thecurves of growth-rate presented in their paper constitute furtherevidence for the real existence of the factors in question. Theyfind t h a t the fat-soluble growth accessory is present in margarinemade from beef fat and oleo oil. The vegetable oils, natural orhydrogenated, contain little or none of the substance, andmargarines made froni them alone are therefore, in this particularrespect, inferior to butter. It is, of course, necessary to view suchfindings as these in proper perspective. Margarine is seldom eatenexcept in dietaries which contain other sources of the accessoryof growth substances. The facts, nevertheless, are by no means ofacademic interest alone.The question as to whether free fatty acids have a nutritive valuefor man and animals is of decided interest a t the moment, theavailable supply being, for obvious reasons, exceptionally great.Physiologists have known for half a century 44 that the animalcan synthesise neutral fats from fatty acids given by the mouth,the necessary glycerol being provided by metabolism; but the limitsof this capacity were not defined, and we have been uncertain as t owhat would be the effect of considerable quantities of free fattyacid on the intestine itself.Some feeding trials have been recentlymade on pigs, in which free fatty acids were made to replace twoand a-half times their weight of the carbohydrate present in acontrol dietary. The animals receiving the fatty acids did as wellas those on the control diet, but the experiments were of somewhatshort duration.4j J.F. Lyman 40 has found t h a t palmitic acidwhen fed to dogs is well absorbed, showing a utilisation of morethan 80 per cent. When given to cats, it was found deposited astripalmitin.Another point with respect t o iiutritioiial values which is of veryreal importance a t the present time concerns the potato. Ourdependence on our potato crops is likely to increme. Although4 3 J . Phjlsiol., 1017, 51, 233 ; A., i, 073.4.1 S. Radziejewslti, Ceiztwlbl. nied. TViss., 1866, S o . 23.4 5 A. Lauder and T. W. Fagan, J . SOC. Cken2. Iitd,, 1917, 36, 1069.46 J . Biol. Chem., 1917, 32, 7, 13 ; A . , i, 714PHYSlOLOQlCAL CHEMISTRY. 187nitrogeiious coiistituents in the tuber are present in relatively smallainount, it is a comfort t o know that the protein has apparentlyail exceptionally high nutritive value, presumably because theamino-acids in i t are well balanced from the point of view of animalrequirements. The fact' was earlier suggested by the observationsof M.Hindhede47 and of K. Thomas,48 and i t has recently receivedconfirmation from the work of Mary S. Rose and Leima F. Cooper.4!'They got satisfactory nitrogenous equilibriuiii with a daily iiitakeof 4-23 grams of nitrogen (0.096 gram per kilo.), a result whichcertainly could not be obtained with a single cereal protein or withmeat. It is probable t h a t the potato will support the niaiiiten-aiice metabolism of the adult on, say, 0.4 gram of protein per kilo.If a reasonable amount of f a t is available, the iiecessary caloriesupply can on a potato diet be obtained with this low level ofi~it~rogen intake.Y'h e G 1.0 1 ~ 1 t 1~ PTO c C.SS ; E ) I t! OY e I I o I I s CCI t ( I 7~ .S t s .I n the previous section I have dealt, more or less incidentally,with animal growth as a process affected by agents which may beclassed as exogenous hormones. Growth, however, is also con-trolled by endogenous hormones, by agents arising within theanimal itself.Whether there is any kind of relation between theexogenous and endogenous factors we do not knou7. The latterare cont'ained in the internal secretions of glands, certainly inthose of the thyroid, the pituitary organ, and the sexual glaiicls.The subject of internal secretion in general does not, however, callfor attention this year, but I feel t h a t an exception should be madein the case of studies by T.B. Robertson so on the influence of thepituitary gland 011 growth.I devote thissection t o them, however, chiefly because of the experimentalmaterial on which they are based. Theories apart, this suggestst h a t even the time relations of growth in iiiainmals may prove tobe very complex, a circumstaiice which must not be overlooked byother workers.During recent years, Robertson has written iiiaiiy papers deal-iiig with the general nature of the growth process.51 His views,however speculative, doubtless call for consideration from thoseThe opiiiioiis of this author challeiige attention.4 7 Skand.Archiu Physiol., 1913. 30, 97.4* Arch. Ph?ysiol., 1909, 319.49 J . Biol. Chem., 1917, 30, 201 ;5 0 lbid., 1916, 24, 349; A., 1916, i, 350.51 For references, see J. Biol. Chein., 1916, 24, 363.A . , j , 524188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.who are interested in the chemical aspects of growth; I refer tothem without prejudice. They are, indeed, too complex andtechnical for efficient treatment here, but a few paragraphs quotedaImost verbatim from the author must be given in explanation ofwhat he considers to be the significance of the results got in pituitaryfeeding experiments. He believes from observation and experi-lnent that the gr0wt.h of man and of animals consists of a numberof phases or growth cycles which succeed one another and t o someextent merge into one another a t the transitional period.Eachof these cycles is characterised by an initial period of slow growthsucceeded by a period of rapid growth, and that in turn by aperiod of slow growth, the entire cycle forming a single S-shapedcurve which is symmetrical about' its centre or moment of maximumvelocity.The chemical syntheses which constitute the growth of an animalare therefore of such a nature that during the first half of anygiven growth cycle the velocity of synthesis is progressively in-creased in proportion as i t has already proceeded; in other words,i t is auto-catalysed or self-accelerated, and as with all auto-catalysed reactions, in the latter half of the cycle growth synthesesare retarded by the progressive accumulation and mass action ofthe products of synthesis.Robertson claims that the formula ofautocatalysis, log x/ A - x = K ( t - t ' ) , accurately represents thequantitative relationships of the growth process as observed when-ever accurate measurements made on a sufficient number ofindividuals have been available. Auto-catalysis implies the exist-ence of catalysts, and these are supplied by the glands of internalsecretion.s2 The author believes that two types of growth may berecogiiised, called by hini respectively the auto-kinetic type, inwhich a growth accelerator progressively increases in amount, andthe auto-static, in which accelerating factors progressively diminish.For reasons fully discussed by the author, but which cannot begiven here, i t is suggested that increase in the mass of the catalystwill lead to an acceleration of the latter half of an auto-static orthe initial half of ail auto-kinetic cycle, whilst a like increase inthe catalyst will retard the latter half of an auto-kinetic or theintial half of an auto-static cycle.The influence of the pituitary secretion was studied on whitemice.As a preliminary to the study, a very perfect technique forI do not pretend to understand the autlior's positionhere. If growth be an auto-catalysed process, o m would suppose thatthe velocity would be controlled by factors arising during the process itself,and therefore taking origin, not in specialised organs, but in each growingtissue.62 See Zoc.cit., p. 364PHYSIOLOGICBTJ CHEMISTRY. 189dealillg \yitll tile animals was developed. A gre;lt llunlber of,lormal growth curves urel-e recorded, and a mass Of statistics COD-cerlliilg variation was obtained.The mouse displays three separate extra-uterine grow‘th cycles.The first cycle attains its maximum velocity at Sol“ time shortlyprior to Seven days after birth, and culminates a t fourteen days.The second attailis to its n~axiniuln velocity at tWenty-011e t otwenty-three days, and culminates soon after the twenty-eighth day.The third reaches a maximum velocity at about the sixth week, andthereafter decreases in velocity continuously but very slowly, sothat growth still continues between the fiftieth and sixtieth weekssucceeding birth.Previous observations on the results of the administration ofpituitary gland have suggested that material contained in theanterior lobe retards the growth of young animals.53 Shafer’s 54experiments, however, gave an indication that although there wasretardation a t early stages, there was later oil no such effect, but,if anything, acceleration. Robertson’s results, based on thebehaviour of a much greater number of animals, confirm this.Hefound that the “administration of 0.125 grain per day per animalof fresh anterior lobe tissue to iiiice, beginning at’ four weeks afterbirth (conclusion of the second growth cycle), leads to retardationof growth during the earlier portion of the third growth cycle,that is, between the sixth and twentieth weeks.In the latter partof the third growth cycle, however, from the twentieth t o thesixtieth weeks after birth, the growth of the pituitary-fed animalsis markedly accelerated, so that they not only catch up tha normals,but’ actually, a t about one year of age, come to surpass the normalsin weight.” Presumably, therefore, the third growth cycle in miceis, in the author’s sense, ‘ auto-static.’ The administration of thepituitary substance means an increase in the concentration of acatalyst, and its effect is, according to him, similar in character t othat of other catalyses of growth.The effects are not marked, and only because they are based onmuch material and because the observer has so carefully consideredthe effect of individual variations are the experimental resultsworthy of attention.Robertson has effected a partial separation of a substalice fronlthe gland which on administration has precisely the Sanle effect ollgrowth as the gland substance itself.This he has calledsee, however, E. Goetsch, Buzz. Johns Hopkins Univ., 1916, 146 ; alsowith regard to invertebrates. R. Wulzen, J. Biol. Chem., 1916, 25, 625 ; A*,1916, i, 692.u Quart. J . Exp. Physiol., 1912, 5, 203190 ANKUAL REPORTS ON THE PROGRBSS OF CHEMISTRY.'' tethelin ''. (T+X&S, growing). It is precipitated by ether fro111an alcoholic extract of the gland. It is a hygroscopic substancecontaining phosphorus and nitrogen in the proportion of four atomsof the latter to one of the former. It gives colour reactions suggest-ing the presence of an iminazole group, and is said to yield i-inositolon acid hydrolysis.The method of preparation, however, givessmall guarantee for purity. I n a quite recent paper,s*j experi-ments intended t o throw light on the effect of pituitary feeding onthe earlier growth cycles of the mouse are described. The attemptwas made t o influence the suckling by feediag the mother withtethelin. Negative results were obtained, which may have beendue t o the fact that tethelin fails to enter the milk. Later, duringthe second cycle (second to fifth weeks), acceleration of growthoccurred, followed by retardation a t the beginning of the thirdcycle, in spite of the fact t h a t administration ceased a t the end ofthe fifth week.When administered hypodermically to mice,tethelin is said t o exert a remarkably stimulating action on thehealing processes in granulating wounds.56Chemistry of Bncterinl GrowtJi.The chemistry of bacterial activity is not abstracted as part ofthe subject with which this Report is formally supposed t o deal.I feel, however, that it is legitimate ground for one's attention.By the chemistry of bacterial activity, I mean the study of cleanreactions which substances of known constitution undergo underthe influence of the organisms. This study, although it began longago, has been neglected during the development of bacterial techno-logy with its special aims and empirical technique. Itl is nowawakening into marked activity, and I believe it will be of funda-mental importance to general biology.Unfortunately, I can sayvery little about it in the present Report.The chemistry of species-the difference in chemical constitutionand in metabolism which is associated with and underlies morpho-logical difference, always a suggestive study-can be investigatedwith special advantages in the unicellular organisms. All thedifferential diagnostic methods of bacteriology are, of course, basedon the variation in the metabolism of allied species.There is something fascinating in observations such as t h a t madeby T. S a ~ a k i , ~ ~ who found t h a t when 13. protezcs acts on tyrosine, it6 5 T. B. Robertson and M. Delprat, J . BioZ. Chem., 1917, 31, 667 ; A . ,66 J . Amer. Med.ASSOC., 1916, 66, 1009.67 Acta Scholae Xed. Kyoto, 1916, 1, 103 ; .4., i, 107 ; also J . BWZ. C'hem.,i, 673.1917, 32, 633191 PHYSIOLOGTCATA CHEMISTRY.fornls c~-hydroxypheiiyl-lactic acid, whereas u. . s . ~ J tilis actillg 011the Same substance forms I-hydroxyphenyl-lactic acid. Specialinterest, attaches to the fact that the products are the same, 110matter whether the parent substance be d- or I-tyrosine. This is alieat case of antipodal differences in the chemical make-up of twospecies belonging to the same order. One would like to know whatelse in met,abolism is correlated with a difference of this sort andhow such differences arise in evolution. It is likely that a sym-rrletrical intermediary compound is in each case first formed fromthe tyrosine, and the respective optical isomerides then synthesisedulider the direction of asymmetrical catalysts.The synlmetricalintermediary might be hydroxyphenylpyruvic acid, which is formedin the animal orgaiiisiii by the deamination of tyrosine, or it’ mightbe hydroxypheiiylacrylic acid. €1. Raistrick,58 a t least, has foundthat histidine, when deaminated by various bacilli of the Colit!/plwsic,s group, gives iminoazolyl-&acrylic (urocanic) acid.This is an interesting observation, as i t is quite possible thatbiological deamiiiatioii of amino-acids may always begin in thisway, the resulting unsaturated acids being oxidised to hydroxy- orketo-acids by a secondary process.As is well known, different species of bacteria under varyingconditions deal with the side-chain of tyrosine (and of otheraromatic amino-acids) in various ways. Dea,mination or decarb-oxylatioii occurs, followed by oxidations of varying intensity.Theside-chain may completely disappear. An anaerobic organism has,for instance, been recently isolated by A. Berthelots’J from theintestine which, acting on tyrosine, produces, under ordinarycultural conditions, about ten times as much phenol as the lnostactive known phenologenic species. It gave under special conditionsa yield of phenol from tyrosine equal to 80 per cent. of thetheoretical.Two new points coiicerning the general nutrient needs of bacteriahave’ come to light of late. F. A. Bainbridge60 showed that manybackria are unable to decompose pure proteins, an observation.since confirmed, and shown to be true even in the case of organismsof the putrefyilig type.61 It.has been further shown that, as alnatter of fact, small amounts of free amino-acids are necessary forthe initial growth of many, if not of all, bacteria.62 S. lv. ColeBiochenz. J . , 1917, 11, 71 ; A . , i , 499.69 Compt. rend., 1917, 164, 196; A . , i, 305.6o J . Hygiene, 1911, 11, 341.J. A. Sperry and L. F. Rettger, J , Biol, Chem., 1915, 20, 455; A . ,1916, i, 482.62 Rettger, Berman, and Sturges, J . Bncteriol. Baltinjore, 1916, 1, 15192 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.alld H. Onslow 63 have described a medium '' tryptalnine '. con-taining free amino-acids from almost completely digested casein a sa successful substitute for neutral peptono media.Organislnswhich are naturally saprophytic, or which may have been madesaprophytic by laboratory subculture, apparently make lessdenlands 011 the specificity of the medium than do those whichare more strictly parasitic. The latter are adjusted to live in theconiplex media represented by living tissues, and apparently needfor their development special stimulating factors. It has long beenrecognised that blood or tissue extracts must be added t o artificialmedia if such organisms are to be successfully grown. The workof Dorothy J. Lloyd64 on the meningococcus seems to make i t cleart h a t the growth of this organism calls, as a matter.of fact, forvitamines. S. W. Cole and D. J. Lloyd65 find t h a t the facts arethe same in the case of the go~~ococcus.I t is noteworthy t h a t themetabolism of bacteria should resemble that of animal cells in deal-ing primarily with amino-acids, and t h a t certain micrcorganisms.a t any rate, should be dependent upon growth stimulants,These considerations lead me t o refer to a somewhat remarkableseries of papers by M. Jacoby. It was found t h a t certain bacteriadiscovered by U. Friedemann in plant tumours were capable ofdecomposing urea.66 An urease can be isolated from the organism,although imperfectly. During the progress of researches with thesebacteria the author recognised t h a t in the urease was to be foundail easily detectable endocellular agent offering, in a sense, analogiest o toxins and the like.He therefore set himself the legitimate andhappily conceived task of studying the various nutritive conditionswhich might make for or against the production of the agent in thecell. On Uschinski's medium, which contains glycerol, ammoniumlactate, sodium aspartate, and inorganic salts, the bacteria remainalive and capable of reproduction; b u t growth is poor and ureaseproduction is small. The addition of serum or of an alcoholic (notan ethereal) extract of serum 67 immediately stimulates both pro-cesses, and so does the presence of mere traces of bouillon.68U p t o this point we seein t o have before us an instance of thenecessity for a vitamine-like factor. It was found, however, thatdextrose 69 in small amounts greatly stimulates the formation ofurease, and the author became of the opinion t h a t the production of6s Lancet, 1916, 11, 1011.6 5 Ibid., 1917, 21, 267.O6 Biochem.Zeitsch., 1916, 74, 109; A . , 1916, i, 529.67 Ibid., 1916, 77, 402; A . , i, 106.68 Ibid., 1917, 80, 359; A., i, 430.69 Ibid., 77, 405; A., i., 106.6 4 J . Path. Bad., 1916-17, 21, 113PBYSIOLOGlCAL CHEMISTRY. 193feriiieiit is increased by the sugar, not merely indirectly, by stimu-iation of general metabolisni, liut because an act.ual precursor, in achemical sense, of tlie urease is supplied. H e believes t h a t suchstudies will ultimately throw light on the actual chemical nature oftlis ferment. It became important, therefore, to define more closelythe nature of substances capable of producing urease.Greatlyefficient is d-galactose; efficient t o a less degree are d- and Z-arabin-ox?, rhamnose, d-mannose, and many other substances tested proveineffective. It is possible to note a common configuration in theeff octive sugars.70 The 3-carbon derivatives ‘of dextrose, namely,glyceraldehyde, dihydroxyacetone, pyruvic acid, and iactic acid, arevery effective. Certain (but not all) amino-acids induce greaterurease production when added t o a medium already reinforced bydestrose and bouillon. From the results of the latest experiments i tis claimed t h a t good production can be obtained in the presence ofsimple substances only, without vitamines, t h a t is, in Uschinski’smedium with the addition of the special carbohydrates or theirderivatives and certain amino-acids, for instance, leucine and iso-1 euci ne.At, this stage, the remarkable observation was made t h a t syn-thetic leucine could not take the place of natural leucine in promot-ing growth or ferment-formation.The author leaves this factwithout clear explanation. If tlie natural leucine was made bycrystallisation after pancreatic or other fermentive proteolysis, or i f ,as is likely, they were separated from molasses, an explanation is,I think, forthcoming; otherwise one sees none. The author’s earlierexperiments show how extremely small an amount of bouillon iseffective in promoting growth. Only so much, for example, as isi1;troduced when organisms from a bouillon-containing medium aresubcultured into one which is bouillon-free.Now the medium int!ie latest experiment was intentionally made t o contain no bouillonor blood, t h a t is, no vitaniine supply. I will here venture to men-tion an experience of my own. There had remained in my labora-tory for ten years a specimen of tyrosine prepared from an autolysedpaitcreas. In the course of certain experiments, the aim of which1 need not go into, it was found t h a t the specimen contained thetissue kinase which coagulates blood plasma. A few milligrainsadded t o 5 C.C. of stable fowl’s plasma induce coagulation in fifteenminutes ; after the tyrosino had been thrice recrystallised fromwater it induced coagulation in t’hirty-five minutes. A specimen oftyrosine prepared by acid hydrolysis of pure casein had, as was tobc: expected, no coagulative effect whatever.Enzymes and otherbiological catalysts derived from living tissues are often associated‘O Biochem. Zeitsch., 1917, 81, 332 ; A., i, 52s ; ibid., 79, 35 ; A., i, 305.REP.-VOL. XIV. 194 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in this close way with apparently pure crystalline preparations. I nthe case of growth-promoting vitainines the effective concentrationmay certainly be as sinall as that of such an agent as thrombo-kinase. Without knowing their origiii, one cannot, of course, say,but I think it is possible that the natural leucines in Jacoby’s experi-ments were effective’ because they introduced an agent from whichthe synthetic product was, of course, free.At least I am glad ofthe opportunity of asserting that in experiments of the kind almostinfinitesimal amounts of material must be reckoned with.I have given much space to Jacoby’s work because I think theideas underlying it are suggestive. Unfortunately, i t seems, how-ever, by 110 means certain that the substances which promote theformation of the endocellular ferment are, as the author supposes,it.; actual chemical precursors, able t o throw light, therefore, on itsconstitution. It remains possible that they promote general meta-bolism and stimulate the formation of the ferment only indirectly.The Pancreas and Diabetes.The extraordinarily voluminous literature bearing on the influ-ence of the pancreas in carbohydrate metabolism continues to grow,although there is as yet no indication that a complete understand-ing of that influence is a t hand.Whoever first thinks of thee.xperinzent~~m crucis which will give us clear light in this darkregion will earn the gratitude of students of metabolism. A paperfrom the laboratory of G. Embden 71 adds something definite t o ourknowledge. When dextrose is perfused through the liver of anormal dog i t is, in part, converted into lactic acid by a reactionwhich is reversible. If the animal be first depancreatised, however,it:: liver no longer yields lactic acid from perfused sugar, but aceto-acetic acid instead. Here is something very tangible, but, as is usualin this domain, i t is by no means easy to correlate the new factswith the old.G. Winfield and I,72 in experiments which have notyet been fully described, found that pancreas extracts inhibit theformation of lactic acid in muscle, and we regarded the result asfurther evidence to show that the pancreatic factor stabilises carbo-hydrate. There is perhaps no actual contradiction in these tworesults, but correlation is difficult. J. R. Murlin 73 having foundthat when alkalis are introduced directly into the duodenum ofdiabetics there is diminution of the glycosuria and hyperglycaemia,and finding, further, that if in the dog the pylorus is tied or the71 G. Embden and S. Isaac, Zeitsch. physiol. Chem., 1917, 99, 297; A . ,i, 496.72 Proc. Physiol. SOC., 1915 ; J . Physiol., 50, V.7 3 J. R . Murlin and J. E. Sweet, J .Biol. Chem., 1916, 28, 261 ; A . , i , 104PHYSIOLOGICAL CHEMISTRY. 195stomach excised before pancreatectomy, the glycosuria whichusually follows the operation is prevented or lessened, decides t h a twhen the pancreatic operation is performed alone i t is the acid ofthe gastric juice, unneutralised in the absence of the gland, whichpoisons the liver and leads t o glycosuria. I cannot think t h a tthese observations help towards an tinderstanding of clinicaldiabetes.G 1cc( n idi IZ e n nd Te t CI r ~ y .As one of the results of an important research 74 into the physio-logy of the parathyroid glands carried out' in the laboratories ofGlasgow University, we are presented with a striking case of acirculating metabolite of known constitution bearing responsibilityfor the control of a normal function, and, when abnormally in-creased, for the production of pathological symptoms. D. NoelPaton and L. Findlay, whilst studying the condit'ioii of T e t m i t rp~r'afhyeoprizw, found t h a t present views concerning the immediatecause of the tetany are unsatisfactory, and were led by certaiiisuggestions iii their work and others in the literature to considerthe possibilit,y t h a t guanidine might be responsible for the familiarpicture of the condition. They found on experiment that thesymptoins of guanidine poisoning closely resemble those producedby removal of the parathyroids. D. Burns and J. E. Sharpedetermined, by a process (satisfactorily controlled) which finishedby the weighing of the bases as gold salts, the guanidine andinethylguaiiidiiie in the blood and urine of normal and para-thyrectoniised dogs, and in the urine of children suffering fromidiopathic tetany. The amounts found in the pathological condi-tions were froni five-fold to eight-fold normal. It was further foundt h a t there was close similarity in the metabolic disturbances pro-duced respectively by removal of the glands and by the administra-tion of a salt of guanidine. The conclusion drawn from theseresearches is t h a t the parathyroids regulate the metabolism ofguanidine, and thus indirectly control the tone of the muscles.Formation of Pigmelit in t h e Skin.The chemical mechanism by which pigment is produced i n theskin has always been a subject of curiosity, because of the greatbiological significance of epidermal coloration. On the discoveryof the oxydases which produce black or coloured products fromaromatic amino-acids, attention was naturally directed to them inthis connexion. Tyrosinases, which certainly play a part in the7 4 Quart. J . exp. Physiol., 1917, 10, 175.IF196 ANNUAL REPORTS ON THE PELOGRESS OF CHEMISTRY.productiou of some animal melanins have been credited withresponsibility for producing skin piginentatioii, Lut the evidencefor this has iiever been stroiig. Tyrosine itself has not offered quitesatisfactory evidence of being concerned in the process. B. Bloch7jhas recently found that 3 : 4-dihydroxyphenylalanine is undoubtedlyacted on by a specific oxydase actually present in human and otherskins, oxidation and condensation leading under its influence to theformation of a black pigment. The evidence t o show t h a t this isreally a physiological phenomenon occurring during life seems tome strong. The precursor itself has not been found in animaltissues or in the products of protein hydrolysis, but was isolatedfrom the juice of F‘icicr Fcrijiu by Guggenheim. It is possible, ofcourse, t h a t it is formed in the animal body from tyrosine else-where than in the skin. The substance is endowed by Bloch withthe uneuphonious ‘ portnianteau ’ name “ dopa,” and we are tospeak of “ dopaoxydase ” and ‘‘ dopamelanin.”F. GOTVLAND HOPKTNS.7 5 Zeitsch. physiol. Chew., 191’7, lo, 22G ; A . , i, 675

ISSN:0365-6217    

DOI:10.1039/AR9171400171

出版商:RSC    

年代:1917

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.THE special circumstance that most countries where agriculturalscience is studied are now absorbed in war gives a somewhatartificial air to many of the published papers. The War hasrevealed weak places in our agricultural systems and research pro-grammes, which the more strenuous of the investigators are engagedin strengthening, and in the process they are overhauling theirstock of ideas and evolving better and more living programmes forfuture work. It could scarcely be expected, however, that theweak places should be announced, and whatever information canbe gleaned from what is stated or omitted in papers publishedelsewhere is better utilised in other ways. In gener~l, thepublished work has dealt with old problems, some of which areobviously being rounded off and got out of the way to make roomfor other and more important work that is not revealed. It seemsinevitable, however, that agricultural science will benefit.Theclose co-operation now existing between the farm and the laboratorycan scarcely fail to let in a flood of new ideas, facts inconsistentwith old hypotheses, and new problems demanding solution, whichwill put out of the running many of the stock problems of thepast, some of which were sadly out of touch with reality. ThisWar is a great' destroyer of artificiality, and is giving us an oppor-tunity of revising our ideas and gaining a truer perspectiire thanwe had in the more easy-going days of the past.The soil is made up of three components : mineral matter, organicmatter, and soil moisture.The mineral matter is derived from theoriginal rock; the particles have been broken up and decomposeduntil they are reduced to dimensions varying from 1 mm. indiameter downward, larger particles being regarded as gravel orsmall stones. Intimately mixed with these are residues of plantsand animals in all stages of decomposition, and the whole is kept1!'198 ANNUAL REPORTS ON THE PKOGKESS OF CHEMISTRY.moist by the soil water. The larger mineral particles call bestudied by petrographic methods. It has been shown 1 t h a t calciumis most commonly present in the coarser materials, such as horn-blende, plagioclase, and epidote, with traces of other minerals. I tdoes not appear, however, t h a t the minerals recognised in thecoarser particles are particularly active in the soil.Thus, neitherorthoclase nor pegmatite appears to react with lime,2 with theliberation of potash, as might have been expected. These coarserparticles seem t o be more important from the physical than fromthe chemical point of view.Unfortunately, petrographic methods cannot be applied t o thefiner particles, the silts and the clay fraction, which contain byfar t h e greater proportion of the reactive mineral matter of thesoil, and no simple method has yet been devised to deal with these.Some information can be obtained by studying their reactions withother substances. So f a r as the more important fertilising sub-stances are concerned, t h e interactions have already been shown 3to resemble adsorptions rather than double decompositions, andmore recent' work4 with a number of salt solutions of varying con-centration shows that the ordinary adsorption equation holds verygenerally.I n working out the details of the adsorption, it is foundadvantageous to use a dye, such as methylene-blue, instead of asalt as the adsorbed material; the phenomena are similar and theobservations can be made much more rapidly. No relationshiphas yet been traced between the amount of adsorption and theamount of colloidal material in the soil,5 nor is any simple methodyet known for estimating the total amount' of colloidal material,although some interesting results are promised from the physicalside.6It is of considerable importance in soil management t o be ableto dislodge the adsorbed potassium from its loose combination sot h a t it may become available as a plant nutrient, and a list hasbeen drawn up showing the order of effectiveness of the varioussalts in this respect; ammonium chloride and calcium sulphate havebeen found t o be considerably more effective than calciumcarbonate.1 E. C.Shorey, W. H. Fry, and W. Kazen, J . Agric Research, 1917,8, 57. * I,. J. Briqgs an? J. F. Breazsale, ibid., 21 ; A . , i, 511.&4., i , 247.who has studied the effect of various cations.And again confirmed by K. Miyake, Soil S c i . , 1916, 3, 583 ;4 J. E. Harris, J . Physical Chem., 1917, 23, 451 ; A , , ii, 443.6 W'. Graf zu Leiningen, Kolloid-Zeitsch., 1916, 19, 165 ; A ., ii, 112.6 H. A. Tempany, J . Agric. Xci., 1917, 8 , 312. This paper deals par-ticularly with the shrinkage of soilsAGRICULL'URAL CHEMETRY ASD VEGETABLE PHYSIOLOGY. 199The inorganic phosphorus compounds of the soil have receivedIt is argued 7 that hydroxyapatite, some attention.is the only calcium phosphate likely to exist in the soil, since italone is stable over the whole range of alkalinity and acidity knownto occur in most soils.A considerable part of the soil phosphorus is in organic com-bination, and only becomes available for the plant when theorganic matter is decomposed. Thus it' was found that some ofthe soils of Brittany responding markedly to phosphates werealmost equally benefited by lime.Investigations showed 8 thatonly little mineral phosphate was present, but after appropriatetreatment with lime, the amount became nearly doubled.The liquid phase of the system, commonly spoken of as the soilsolution, is of great practical importance, because i t is the mediumfrom which plants draw many of their elements of nutrition, andit has formed the subject of a great deal of discussion. It is byno means easy to reniove i t from the soil for experimental pur-poses, because the soil possesses marked colloidal properties andgreat powers of adsorbing substances from solutions. A centri-fugal method of extraction has been used, but it is troublesome inapplication. Displacement methods would be easier if one couldbe certain that the adsorption relationships were not thereby beingupset; paraffin oil is saidQ to be unobjectionable and effective,yielding a soil solution that contained 0.07 to 0.13 per cent.oftotal solids, which was thus more concentrated than ordinary drain-age water. The proportions of nitrogen, potassium, calcium, mag-nesium, and phosphorus were found t o vary in the extracts obtainedfrom various soils, and not to be constant', as had been anticipatedon Whitney and Cameron's older view.A pressure method of extraction has also proved effective, especi-ally for soils containing much clay or humus. I n Ramann'slaboratory, 3 kilos. of soil were subjected to a pressure of 300 kilos.per sq. cm. The amounts of calcium and of potassium were foundto vary considerably in different extracts obtained from the surfacesoil, the proportions relative to the other constituents increasingas the solution became concentrated by dry weather and fallingas the solution became diluted by rain.I n extracts prepared fromthe subsoil, on the other hand, the amount, of calcium showed lessvariation, except only for a rise a t midsummer. There was evidenceof a transportation of calcium and potassium from the subsoil t o(Ca3P,O,),Ca(OH,)'H. Bassett, jun., T., 1917, 111, 620; A . , ii, 413.C . Vincent, Compt. rend., 1917, 164,_409.J. F.-Morgan,-SoiZ-Xci., 1917, 3, 531200 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the surface during a prolonged period of drought. No indicationwas obtained, however, that soil adsorptions exercised any regu-lating effect on the concentration of the soil solution; an exchangeof bases took place only wheh the proportions between the dissolvedsubstances were altered .lo The pressure method has also beenadopted in van Zyl's laboratory, and here again the concentrationof the solution varied according to manurial treatment and theseason of the year; i t is claimed, however, that' the percentagecomposition of the ash remained constant .I1 A long, theoreticalpaper on the subject has also appeared12 pointing out the effects ofthe displacement of equilibrium by the action of climate, plantroots, etc.Some of the reactions of the soil solution are very important.I n certain circumstances, iron is dissolved in the upper layer ofthe soil and precipitated a little lower down, forming animpermeable layer or '' pan" through which water will not pass.Formerly, this was considered t o be an alternate oxidation andreduction, and the possibility of bacterial oxidation still remains.'"The action is now, however, generally regarded as a coagulation.This view has recently been critically discussed, and a study hasbeen made of the effects of composition of soil, of climate, and ofvegetation .I 4Another and most important property of the soil solution is itsreaction, whether acid, neutral, or alkaline. Plants will onlytolerate a limited range of variation, and some are much moresusceptible than others. Periodical additions of lime or of calciumcarbonate are needed in order that a proper reaction may be main-tained.Hitherto, the acidity has been expressed in terms of theamount of alkali or of lime necessary to effect neutralisation. Ifwe knew the nature of the soil acids this would suffice, but we donot; the most diverse views are held, some regarding them asorganic acids, some as iron and aluminium salts, whilst others denythe existence of acids and regard the phenomena as colloidal mani-festations. The present methods do not allow of sharp discrimina-tion between these conflicting ideas, and indeed it is possible thatall three cases, and others as well, occur in nature. Evidence hasbeen adduced to show that a clear distinction must be madebetween the base-absorbing power and the absolute acidity of thelo G.Ramrtnn, S. Marz. and H. Rauer, Int. Mil. Boclenkunde, 1916, 6, 27 ;l1 J . P. van Zyl, J . Landw., 1916. 64. 201 ; A . , i, 439.l2 0. Nolte, ibid., 1917, 65, 1 ; A . , i, 621.l3 P, E. Brown and G. E. Corsoii, Soil Sci., 1916, 2, 549; A., i , 248.l4 H Stremme, Kolhid-Zeitsch., 1917, 20, 161 ; A., i, 512.A , i , 311AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 201~0il.15 A new method is therefore needed. Several attempts havebeen made to see if the hydrogen-ion concentration will give usefulinformation, and it seems quite promising. The drawback of thetitration method is that i t indicates only the amount and not thenature of the acid present; it does not, for example, show whetherthe acid is vigorous or only feeble in nature. The hydrogen-ionconcentration does give this information.Sorensen showed som0years ago that measurements of the hydrogen-ion concentrationwere of considerable value in dairy investigations, and cleared updifficulties which appeared insoluble on the older methods.Attempts are now being made to apply the method to the studyof the soil. So far, only details of technique have received muchattention ; it is found 16 that electrometric and colorimetric methodsgive substantially the same results. The exponents (on the schemesuggested by Sorensen17) vary in the soils so far examined from4.4 to 8.6. As an instance of the possible use of the method, twosoil types in North Maine have been studied.18 Both are ex-tensively cropped with potatoes; on one (Washburn loam) thepotato scab is common, on the other (Caribou loam) the scab israre.I n the former case the exponent is 5.2, in the latter it is3.9, the more intense acidity of the Washburn loam being beyondthe limits of toleratJon for the organism-causing scab. Investiga-tions have shown that certain other micro-organisms cease t o growwhen the exponent is less than 5.3. It is also claimed that roseinildew only occurs within a certain limited range of soil reaction.20The limits of tolerance of barley have been studied,21 and theresults show that t'he hydroxyl ion is even more toxic than thehydrogen ion ; in practice, however, the hydroxyl-ion concentrationis not likely to reach the toxic limit in normal soils.The third great component of the soil complex is the organicmatter. This is largely derived from plants, and its characteristicis that it is perpetually undergoing decomposition, so that all stagesare present, from the original plant constituents, the starting pointin the long chain of decomposition, to the final products, carbonicacid, nitrates, and water.H. R.Christensen, Soil Sci., 1917, 4, 115; A., i, 684; compare alsoL. J. Gillespie, J . Washington Acad. Sci., 1916, 6, 7 ; A., 1916, i, 303.17 S. P. L. Sorensen, Biochem. Zeitsch., 1909, 21, 131 ; A., 1909, i, 861.18 L. J. Gillespie, and L. A. Hurst, SoiZ Sci., 1917, 4, 313.19 W. M. Clark and H. A. Lubs, J . Bact., 1917, 2, 1. Othermeasurements are recorded by 0. M. Gruzit, Soil Sci., 1917, 3, 289; A.,i, 430.20 A. Stutzer, Biochem..Zeitsch., 1917, 80, 143 ; A., i., 439.C . J. Schollenberger, Soil Sci., 1917, 3, 279 ; A . , i, 440.D. R. Hoagland, Soil Xci., 1917,3, 547 ; A., i, 619.H202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The general method of investigation is to study the decompositionof plant constituents in the laboratory, and then to see whetherthe same products occur in the soil; if they are present in quantity,it' is assumed that the process in the soil has been identical witht h a t i n the laboratory. Most of this work has been done in theUnited States, very little having been achieved in this country.Two main groups of cornpouncls have been studied, theproteins and the carbohydrates. Perhaps the most striking pro-duct, and certainly the one t h a t for long claimed most attention,is humus, a black, rather indefinite substance, soluble in dilutealkalis, but largely precipitated on addition of acids.A similar-looking substance has been prepared in the laboratory by the inter-action of reducing sugars and amino-acids722 and attempts havebeen made to establish the identity of this artificial black substancewith soil humus; proof of the identity would represent a greatadvance in soil chemistry. I n other investigations,23 sucrose orsome other polysaccharide occurring in plants is heated or treatedwith acids, and the product is studied in the hope t h a t some lightwill thereby be thrown on the formation of humus in the soil; theinformation obtained does not always, however, necessarily beardirectly on the soil problem. Recently, doubts have been expressedwhether the soluble part of the humus really is as important a soilconstituent as the older chemists thought.Weir showed24 in1915 t h a t soil from which soluble humus had been largely removedby alkalis was as productive as the original soil. The experimentis not entirely convincing, because of the possibility t h a t otherchanges brought about by the treatment might obscure the effect,but a t any rate i t throws doubt on the traditional view t h a t solublehumus is indispensable t o soil fertility. It is urged in favour ofthis view that soils which are made productive by the addition oforganic manures contain quantities of humus proportional t o thegrowth of the crop,25 but the experiment really only proves thatthe quantities of hurrius are proportional to the added manure.Asounder method has been followed by Gortner,26 who shows t h a tfresh vegetable matter yields to alkalis an extract which is verysimilar to that yielded by soil, except that it is colourless, andfurther, t h a t the amount of humus is greatest immediately afterthe manure is added and before the supposed humifying organisms22 L. C. Maillard, Aan. Chim., 1917, [ix], 7, 113 ; A . , i, 251.23 Miss M. Cunningham and C. Dorbe, T., 1917, 111, 589; A . , i , 513.A. T~OUSSOV, Selskoie Khoxiaistvo i Lesorodstco. Petroqrad, 1914, 74, 233 ;A . , i, 189.zi W. Weir, J . Agric. Sci., 1915, 7, 246.25 R . H. Cam, Soil Sci., 1917, 4, 515.2G R.A. Gortner, ibid., 1910, 2, 395, 539; 1917, 3, 1 ; A . , i, 218, 311AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOG Y. 203have begun l o work. It is therefore argued that the soluble humusis not a soil product a t all; the black piginent only is the resultof soil deconipositions, but this forms not more than 30 t o 40 percent. of the soluble humus, i t contains only a relatively small pro-portion of the soil nitrogen, and is of no great importance in theproblem of soil fertility. I n this investigation, also, no evidencecould be obtained t h a t the phosphorus compounds in the alkalineextract were of more value to plants than those extracted by acids,as had been assumed by Grandeau and taught by his school.Turning now to the second great group of plant products, theproteins in t h e plant break down in the soil with the formation ofammonia, which oxidises to nitrites and finally to nitrate.Thefirst stage in the process is supposed to be the ordinary proteindegradation studied in the laboratory. The van Slyke method ofprotein analysis has been applied t o a number of soils27 of varioustypes, and the results show t h a t the distribution of the nitrogenamong the various fractions is substantially the same in all thesoils examined. It is assumed, therefore, t h a t the same organiccompounds of nitrogen occur widely in different soil types. It isnot possible to compare the figures with those directly obtained inthe laboratory hydrolysis of protein, because the presence of thesoil mineral matter somewhat affects the result.Besides these attempts to group the soil constituents, effortshave been made, also largely in the United States, to isolate andidentify individual compounds present.The number of possibili-ties is considerable, and the labour involved is correspondinglygreat, b u t a good deal of success has been achieved. This yeartwo new constituents have been isolated, namely, cyanuric acid 28and a-crotonic acid ; 29 the latter possibly arises from cellulosethrough the intermediary of the 8-hydroxy-acids, or else from ally1cyanide, which is present in the ethereal oils of certain plants.I n addition t o this descriptive work, attempts have been madeto trace out t h e mechanism of the change. Micro-organisms appearto be the active agents, and a vast amount of work has been doneto elucidate their relationships t o one another and to soil fertility.A great cycle of changes has been recognised; in the up grade, theliving plant takes up the nitrates and other simple salts from thesoil and elaborates them into complex organic substances rich inenergy derived from sunlight; in the down grade, the organisms inthe soil decompose t h e dead leaves, stems, etc., of the plants, pro-27 C.A. Morrow and R. A. Gortner, Soil Sci., 1917, 3, 297 ; A . , i , 512.28 L. E. Wise and E. H. Walters, J. Agric. Research, 1917, 10, 85 ; A . ,29 E. H. Walters and L. E. Wise, ibid., 1916, 6, 1043 ;i, 622.A . , i, 376.H* 204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ducing again the simpler salts out of which the plant had builtup its substance, and liberating in the process tthe energy storedup by the plant during its lifetime, which energy serves for theneeds of the soil population.111 an extended series of observationson the Rothamsted plots, the curves showing the rate of productionof carbon dioxide and of nitrate sufficiently resemble the curvesfor the bacterial numbers as revealed by counts on gelatin platesto justify the view that a causal relationship exists between thesequantities.30 The curve for nitrate accumulation, however, alwayslagged two or three weeks behind that for bacterial numbers, thusindicating that the formation of nitrate is dependent on someprevious change, which in turn is dependent on the bacterialnumbers.An obvious possibility is that the first change is theproduction of ammonia, which goes on simultaneously with theincrease in bacterial numbers, and that this is followed by theproduction of nitrate, which is independent of the organismscounted on t'he gelatin plates; the lag then would represent thetime required for the conversion of ammonia into nitrate. Thisis not a sufficient explanation, however, because it is known31 thatthe amount of ammonia in the soil is normally a t a minimum, andtherefore that the rate of conversion of ammonia into nitrate mustequal or be greater than that of the production of ammonia. Ifwe are to regard the curves as related, the dividing up of the reac-tions must go further back, and the forination of ammonia must besupposed to involve two stages, the first being brought about bybacteria capable of growing on gelatin plates, and therefore fluctu-ating according to the numbers there recorded, whilst the second issubsequently and more slowly broughtl about by the organisms, or inanother way. This delay in the production of ammonia has alsobeen observed in studies on protein bacteriolysis.32 It has beenargued33 that the rate of the production of ammonia can be ex-pressed by the usual equation for autocatalysis, namely,log x/ A - x = K ( t - t J , where x =amount of ammonia produced a ttime t, A =total ammonia produced during the process, andt,=time in which half the total ammonia is produced; i f thisobservation should turn out to be well founded, it would throwimportant light on the whole process.Another observation that may have an important bearing onso E.J. Russell and A. Appleyard, J . Agric. Sci., 1917, 8, 385.31 E. J. Russell, ibid., 1910, 3, 233 ; confirmed by P. L. Gainey, Soil Sci.,32 R. H. Robinson and H. V. Tartar, J . Riol. Chem., 1917, 30, 135 ; A . ,33 K. Miyake, SoiZSci., 1917, 4, 321 ; A., i, 718.1917, 3, 399 ; A., i, 529.i , 498AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 205the subject is t h a t soil organisms appear by preference to attackcarbohydrates, and so long as they can get these they make verylittle effort to break down proteins and release ammonia.34It must not be assumed t h a t bacteria are the only organismsconcerned in t h e decomposition processes.Evidence is accumu-lating t h a t there is a characteristic fungal flora in the soil whichalso plays a part in the reactions.35The circumstance t h a t semi-arid soils forin a large area in theUnited States has led investigators t o consider whether the solublesalts occurring in these soils cause any fundamental niodificationin the bacterial decompositions taking place there. No f unda-mental difference has been observed, although there are indicationsof certain differences. For example, in the case of humid soils, therate at which ammonia is produced from organic substances, suchas dried blood, mixed with the soil often gives a useful indicationof the fertilising values. I n arid soils, however, the rate a t whichnitrate is produced is considered to give a better i n d i ~ a t i o n .~ ~ Ifthis should turn out t o be correct, it would indicate t h a t nitrifyingbacteria are affected by the soil conditions in much the same wayas the higher plants, whilst some of the ainrnonifying organisms arenot. A certain amount of evidence in this direction has beeiiadduced.37 The effect of irrigation has been studied in some detail,and data have been accuniulated; it was fouiid3s under the condi-tions obtaining a t Utah t h a t the growth of a crop caused an increasei l l the number of the organisms (presumably because of the cropresidues thereby added t o the soil), and that watering the fallowsoil also caused an increase, whilst watering the cropped soil didiiot.It is possible t h a t the failure of the bacteria to increase i nnumbers is brought about by some other lirniting factor, whichbegins to operate when the iiunibers reach the 6 or 7 millions pergram attained in these experiments.More important, however, than the watering is the effect of thesoluble salts usually present in some arid soils. The effect is com-plex and ~ a r i a b l e . ~ g Broadly speaking, the acid radicle is found 40t o play the more important part in controlling the rate of produc-tion of ammonia, the order of decreasing toxicity being usually:chlorides, nitrates, sulphates, carbonates. The phenomena closely3 4 S. A. Waksman, J . Amer. Chern. SOC., 1917, 39, 1.503 ; A . , i, 613.35 S . A. Waksman, Soil Sci., 1917, 3, 565.36 C.B. Lipman and P. S . Burgess, ibid., 3, G R ; A . . i , 243.37 P. E. Brown and E. B. Hitchcock, ibid., 4, 307; A . , i, 717.38 J. J. Greaves, R. Stewart, and C. T. Hirst, J . Agric. Research, 1917,89 W. P. KelIey, J . Agric. Research, 1916, 7 , 4 1 7 ; A . , i, 431.40 J . J . Greaves, Soil Sci., 1916, 2, 443 ; A . , i , 243.9, 293206 ANNUAL REPORTS ON THE PROGRESS OF CEEMISTRY.resemble those shown by plants; in each case, similar quantities ofthe various salts cause similar reductions in growth, a d in eachcase, also, the toxicity of certain salts is readily counteracbd byt h e addition of sufficient calcium salt.41 Whilst the increasedosmotic pressure exerted by the added salts is no doubt an importantfactor, it is probably not the only one in retarding bacterial activityin the soil.It was shown some years ago t h a t the organisms decomposingthe plant residues, with the production of ammonia and nitrate,cannot be regarded as the sole inhabitants of the soil; there existsanother group, including the soil amcebz and possibly other forms,which on the whole are detrimental, b u t are more readily killed;hence partial sterilisation of the soil increases the rate of the pro-duction of nitrate, and therefore the fertility of the soil.Sincethis view was first published42 in 1909, there has been a consider-able volume of research on the subject, which has recentlybeen conveniently summarised ; 43 well above 300 papers arediscussed.It has been supposed that, some physical effect is brought aboutduring the partial sterilisation, but i t is not clear that.this wouldplay any great part in the matter, because the increased fertilityis no more when the soil is extracted wit'h the antiseptic (forexample, toluene) than when the two are simply brought intocontact.44Simultaneously with the laboratory investigations, attempts arebeing made t o apply the results in practice, in this country inglasshouse culture 45 and in France in outdoor nursery work.Toluene, carbon disulphide, and bleaching powder are all effectiveagents;46 an emulsion of carbon clisulphide is proving very satis-factory a t the National Reconstruction Nurseries a t Versailles.47No review of chemical and biochemical investigations of the soilwould be complete without some reference t o the work on soilphysics.The problem attracting most attention is the relation-ship between the solid and the liquid components of the soil,especially the distribution of the liquid between the soil and theplant. Freezing-point determinations have indicated a connexionbetween the concentration of the soil solution and that. ofthe root, sap, which becomes especially marked a t a certain low41 G. P. Koch, J . Biol. Chem., 1917, 31, 411 ; A . , i , 622.42 E. J Russell and H. B. Hutchinson, J . Agric. Sci., 1909, 3, 111.43 N. Kopeloff and D. A. Coleman, Soil Sci., 1917, 3, 197.4 4 J. P. du Buisson, {bid., 353 ; A . , i, 529.45 E. J. Russell, Country Life, Dee. 8, 1917, p. 548.46 11. Miege, Compt.rend., 1917, I@, 362.47 Country Life, Oct. 20, 1017, p. 366AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 207water content of the ~0il.48 Relationships are also indicatedbetween the amount of so-called ‘ ‘ unfree ” water (the water which,according to dilatonieter measurements, does not freeze a t- 3 O ) and the so-called wilting coefficient, or water t h a t is notavailable to plants.49 Further, work has been done on therelationship between the so-called ‘‘ hygroscopic coefficient,” theamount of moisture absorbed by dry soil from a moist atmo-sphere and the water-holding capacit’y of the soil .SO Numerousmeasurements of the movement and distribution of water in soilehave also been collected and discussed.51Critical examinations are much needed of these various“coefficients” t h a t have been set up froin time to time by differentinvestigators.The permeability of the soil to water, which is nodoubt a related phenomenon, is influenced by the presence of dis-solved salts, and the effect is probably as much chemical as it isphysical in character.52 It is shown also t h a t the electrical con-ductivity of the salts is much affected by the soil colloids.~3Soil Formation and Soil Surueys.Evidence is gradually accuinulating that a twofold origin mustbe sought for the soluble salts in alkali soils. Formerly, it washeld t h a t the whole of the salts arose by weathering, and remainedi n sitic because the rain was insufficient t o wash them out. Now i tis considered t h a t this action, although it may take place, is toorestricted to account for all the phenomena.The alkali issupposed to arise mainly from salts pre-existing in the underlyingrock and deposited originally from the inland seas and lagoon.which in past geological ages occurred in the regions in question.These salts are brought to the surface by irrigation water as soonas irrigation begins, and they come into contact with other saltsalso carried by the water or present in the soil; various inter-actions then take place. These account for the salts actuallyfound on the surface; the iiivestigations are also suggesting methodsby which the trouble can be 0vercome.5~ The possible effect. ofcolloidal humus substances has also been discussed .5548 h1.M. McCool and C. E. Millar, Soil Sci., 1917, 3, 113.49 G. J. BOU~OUCOS, J. Agric. Research, 1917, 8, 195 ; A . , i, 510.s1 F. S. Harris and H. W. Turpin, ibid., 10, 113 ; (Utah Soils), H. E.s2 D. J. Hissink, Bied. Zentr., 1917. 46, 138 ; A . , i, 509.5 3 M. I. Wolkoff, Soil Sci., 1017, 3, 423 ; A . , i , 621.s 4 R. Stewart and W. Peterson, J. Ayric. Research, 1917,10,331.s5 H. Puchner, Kolloid-Zeitsch., 1917, 20, 209 ; A., i, 532.F. J. Alway and G. R. McDole, ibid., 1917, 9, 27 ; A . , i, 509.Pulling, Soil Sci., 1917, 4, 239208 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Soil Surveys.-During the year, an interesting survey of thesoils of North Wales has been published, and the relationshipsbetween the various soils is discussed.56 The soils differ from thoseexamined by Hall and Russell; in particular, their coarse frac-tions are much more complex in composition, containing quantitiesof alumina and iron oxides instead of being composed almost whollyof silica.They resemble the “Steinboden” of Ramann, and forrnan interesting contrast with those hitherto studied in this country.It is gratifying that an investigation into their characteristics hasbeen undertaken; i t may reasonably be expected to throw muchlight on many of the problems of soil formation.I n this part of the subject much more work has probably beendone than has been published. The reason for this reticence ismainly the intimate relationship between f ertilisers and explosives.The nitrogenous fertilisers naturally attract most attention.Ever since Sir William Crookes’s famous address t o the BritishAssociation in 1898, chemists have attempted to prepare nitrogenousfertilisers direct from atmospheric nitrogen.The problem hasbeen solved, and enormous quantities of ammonia and of nitricacid are now being synthesised on the Continent. A sufficientlygeneral account of some of the British experiments has beenissued.67 It may be inferred that very considerable quantities ofthese substances will be available as fertilisers after the War, andthat agricultural practice will undergo certain modifications inconsequence.Calcium cyanamide, in particular, is likely to come into con-siderably extended use. As hitherto prepared, it suffers from thedrawback that i t is too fine a powder t o be easily applied to thesoil; i t blows about, gets into the eyes, ears, and noses of theworkmen, and is a cause of considerable friction with them.Onemethod of overcoming the difficulty, said to be successful inGermany, is to add 15 per cent. of coal tar.58 Another methodgives a product satisfactory from the physical point of view, butnot from the chemical, since i t leads to a certain amount of poly-merisation to dicyanodiamide. Indeed, perhaps the chief draw-back to cyanamide is that it is liable in certain circumstances t ochange to dicyanodiamide, which has little if any fertilising action,and is even harmful in excess. It is essential for the success of56 G. W . Robinson, J . Agric. Sci., 1917, 8, 338.57 E.B. Maxted, J . SOC. Chem. Ind., 1917, 36, 777 ; A . ii, 465.58 Schmoeger and Lucks, Mitt. deut. Landw. Gesell., 1917, No. 10, 156AGRICULTURAL CHEMISTRY AND VEGETABLE PBYSTOLOGY. 209the new industry that this change should be studied very fullyand that some method of reversal should be discovered. Severalmethods of estimating the amount of dicyanodiamide have beendevised, based on the fact that cyanamide gives a precipitate withsilver nitrate and ammonia, whilst dicyanodiamide does not .59Investigations have also been published on the constitution ofcyanamide,60 and a reaction which yields guanidine,61 which mayhelp to throw light on the transformation it undergoes in the soil.It is well known that sulphate of ammonia produces harmfuleffects in acid soils, but whether this results from increased aciditydue to removal of ammonia or to some definite toxic effect of thesalt itself is not clear.Evidence has this year been adduced toshow that the latter is the cause62 where barley is concerned; onthe other hand, the results with buckwheat appeared t o 110diff erent8.63The shortage of nitrates and ammonium salts has brought intoprominence other possible sources of nitrogen. First and fore-most, it is essential to economise as much as possible the nitrogencompounds in the farmyard manure produced on the farm itself,which is by far the commonest and the most important of allmanures. I n this country, some 37 million tons of farmyardmanure are produced annually, worth probably about .$ll,OOO,OO@ ;all other fertilisers consumed in the United Kingdom added togetherdo not exceed 1.1 million tons per annum, worth about 24,540,000.It has been shown64 that the losses of nitrogen from farmyardmanure as ordinarily treated on the farm may easily amount t oonehalf of the total quantity, whilst the value of the lost materialis still higher, because the most available compounds go first,.Theinvestigation showed that loss was due. to three causes : washing outof soluble compounds by rain-water percolating through the heap,volatilisation of ammonia, and an evolution of gaseous nitrogen.This last reaction was studied in considerable detail. It was foundnot to go on under complete anaerobic or complete aerobic condi-tions; thus it is neither a simple reduction nor a simple oxidation.It, requires a combination of aerobic and anaerobic conditions, suchas readily occurs in an ordinary manure heap, and a general hypo-thesis is put forward to account for the reaction.The investiga-69 G. Hager and J. Kern, Zeitsch. angew. Chem., 1917,30, I, 53 ; R , ii, 618 ;A. Stutzer, Zeitsch. angew. Chem., 1916, 29, 417 ; A . , ii, 159.8o E. Colson, T., 1917, 111, 554 ; A., i, 448 ; compare also E. A. JTerner,T., 1916, 109, 1325 ; A., i, 82.61 E. Schmidt, Arch. Pharm., 1916, 25p, 626; A . , i, 440.6a H. G. Soderbaum, Bied. Zentr., 1916, 46, 454 ; A . , i, 192.63 R. C. Cook, and F. E. Allison, Soil Sci., 1917, 3, 487 ; A . , i, 623.R 4 E. J. Russell and E. H. Richards, J. Agric.Sci , 1917, 8, 495210 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion brought out the fact that the ideal conditions for storageare complete absence of air and a temperature of about 2 6 O ; underthese conditions no loss of nitrogen occurs, but only a breakingdown of the complex nitrogen compounds with the formation ofammonia, which is entirely beneficial. These conditions are notattained on an ordinary farm, but investigations have been putin hand to devise methods for securing them.Attempts have been made t o reduce the loss of nitrogen byadmixture of various substances, and it is claimed t h a t both gypsumand sulphur are e f f e ~ t i v e . ~ ~ I n a long-continued series of fieldtrials a t Ohio,66 the addition of gypsum to farmyard manure wasfound to be beneficial.It is arguable, however, that the result isdue to the well-known beneficial effect of gypsum in alkalineconditions.Attempts have also been made to utilise the fermentation pro-cesses of the manure heap for increasing the solubility of the phos-phates in rock phosphate. The older efforts a t mixing rockphosphate with manure gave no clear indications of any increasein solubility; i t is claimed,67 however, that the further addition ofsulphur does bring this about.I n order t o reduce the fly pest in manure heaps, American ex-perimenters have suggested the addition of boron compounds.Experiments have been made to ascertain whether quantitieseffective as a larvicide are harmful to the crop. It appears thatthey are not; the soluble borates, which would be injurious if theyremained as such, are converted in the heap into insoluble andinnocuous compounds .68The liquid manure which drains away from the heap or thestables is rich both in nitrogen and in potash, and considerableattention has been paid to the proper method of storing and usingi t .I n Germany this is regarded as one of the best ways of over-coming the shortage of nitrogen f ertilisers of which agriculturalwriters are complaining.69 A method said to answer well is t ostore the liquid in a tank under a floating wooden cover, and thento cover the whole with a thin layer of oil. This keeps out airand reduces loss of nitrogen.70The New sources of nitrogenous fertilisers are being exploited.6 5 J. W.Aines arid T. E. Richmond, Soil Sci., 1917, 4, 79.66 Ohio Agrk. Expt. Station.,G7 P. E. Brown and H. W. Warner, Soil Sci., 1917, 4, 269. J. G. Lipman68 F. C. Cook and J. B. Wilson, J. Agric. Research, 1917, 10, 591 ; A , ,6o E. Blanck, Puhlings Landw. Zeit., 1917, 265.'0 C. Ortman, Arb. Dewt. Lnndw. Ges., 1916, 282.Circ. 144.and H. C. McLean, ibid., 337.i, 721AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 21 1fertilising value of city wastes is receiving attention in America,and it is shown t h a t city refuse can be treated so as t o yield bothf a t and a fertiliser.71Efforts are also being made to obtaiix a fertiliser from wasteleather which cannot be used otherwise. The leather is digestedwith sulphuric acid until it dissolves; on cooling, it sets t o a glue-like substance, which can be ground to a powder. So far, theproduct has not, commended itself to agricultural chemists in thiscountry, b u t it is used in some countries as a base in compoundingmixed manures; the French experiments appear to have been moresuccessful than others.72The methods of analysis of organic manures of this kind, manyof which are very indefinite in composition, are naturally ratherconventional ; reasons have been adduced for preferring the directnitrification test rather than the aininonification test ,73 althoughthe alkaline permanganate method is also said to give good results.74Much more interesting than these attempts to find new fertilisers(valuable although these are) are the efforts to utilise bacteria asagents in nitrogen fixation.The method is attractive, because itseems t o hold out the prospect of getting something for nothing,which always appeals to frail humanity. Certain bacteria areknown to absorb gaseous nitrogen and build it8 up into proteiii.This process has been carried out on the laboratory scale, and thenecessary conditions are tolerably well known ; there is no funda-mental reason why it should not succeed on the large scale. Twotypes of organisms can bring it about: free living organisms suchas Azotobacfer, and organisms living in or symbiotic with legu-minous plants, clover, etc. Since the reaction is endothermic, i t isobviously necessary to supply a source of energy ; easily oxidisablecarbohydrates are found the most suitable.This, of course, limitsthe practical possibilities, niannitol, perhaps the most suitablesource of energy for Azotohctcter, being very costly. Thepentosans, however, are found to answer, and these are morecommon; i t has been shown75 that horse fzces favour the fixation,but their value depends on the diet the animal is receiving, beillgconsiderably higher on a corn and hay diet than on one of grass;under favourable conditions, 4 milligrams of llitrogell a1.e fixed forevery gram of fzeces oxidised. Bullock faeces also serve so long as71 P. J. Schroeder, J . I n d . Eng. Chem., 1917, 9, 613.72 It. Guillin, Ann. Sci. Agron., 1916, 33, 337.73 C. B. Lipman and P. S. Burgess, Sod Sci., 1917, 3, 63 ; A ., i, 243;7 4 C. H. Jones, Vermont Agric. Expt. Stwtion, 1913, Bull. 173.7 5 E. H. Richards, J . Agric. Sci., 1917, 8, 299.J . Agric. Research, 1916, 7, 47212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYthe animal is receiving cake, but not when he receives grass only.The investigation opens u p a number of interesting possibilities.Attempts have been made to increase the effectiveness of theclover organism by inoculating suitable strains on the seed beforesowing, and this method is being recommended in Germany tohelp in overcoming the shortage of nitrogenous manures ar:dproteins.76 It appears also that inoculation of non-leguminouscrops with nitrogen-fixing organisms has been attempted, althoughfull details are not yet available.77 Danish trials made between1905 and 1910 have again been sumniarised; inoculation is shownto have been effective for the first and second years on lucerneaiid lupines growing on unmanured land .78 Russisn experimentshave also given satisfactory results, the increase generally varyingfrom 20 t o 40 per ~ e n t .7 ~The shutting off of the supplies of Stassfurt, salts has led 10many efforts t o obtain potassium salts from other sources. Whilstthese efforts are not yet completely successful, they hold out con-siderable promise for the future. Blast-furnace flue dust is beiiigused as raw material in this and the wash-water fromwool scouring has been suggested.81 I n the United States, dustfrom cement works,82 kelp, and certain natural deposits of salts insome of the Western States of America 83 are being used; the totaloutput in 1916 was equivalent t o 10,000 “short” tons of potash(K20), this being ten times the output for 1915.84 I n the mean-time, substitutes are being suggested.Sodium salts have longbeen known t o serve, and the Rothanisted experiments have showlit h a t both the sulphate and the chloride are effective for a periodof years, although not, of course, permanently. They are beingwidely recommended as partial substitutes for potash even iu76 L. Hilt’ner, “ Vermehrte Futtergewinnung aus der heimischen Pflanzen -7 7 L. Hiltner, Mitt. Deut. Landw. Ges., 1916, Heft 36.78 H. R. Christensen, Centr. Bakt. Par., 1016, 46; also in Tidskrift f.‘9 I. A. Makrinov, Petrograd, 1916.An English account is given in Bull.80 H. T. Cranfield, J . Board Ayric., 1917,24, 526 ; compare also 24, 852.81 A. F. Baker, J . Leeds Univ. Tertile ARSOC., 1915, 4, 69.82 W.H.Ross,andA. R.Merz., J . Ind. Eng. Chem., 1917,9,1035, and numer-ous other papers in the same journal. From the circumstance that a newGerman substitute “Germaniaphosphat” (63 per cent. K,O, 8-7 per cent. P,O,)is produced at the Germania Portland Cement Works a t Hanover, we mayperhaps infer that this kiln dust is being used in Germany also. (SeeFuhlings Landw. Zeit., 1917, 66, 65.)welt,” Stuttgart, 1917.Plantearl, 21, 97.Agric. Intell. Rome, 1917, 8, 196.83 J. E. Pogue, Smithsonian Institution Bull., No. 102, Part 2, 1917.8 1 U.S. Commerce Rept8., 1917, No.46, p. 728AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 213Germany, where, contrary to expectation, the shortage of potassiumsalts appears to be felt.Rs Ground phonolitc is being recommendetliii Austria as a substitute for Stassfurt salts.86Gypsuni is often said t o increase the supplies of potash t o theplant, but on wholly inadequate grounds ; the Rotharnsted experi-ments are completely against this view. American experienceshows, however, that gypsum is undeniably a good fertiliser at times.It appears to act best on alkaline soils; it should never be used onan acid ~0i1.87 Its effectiveness appears to depend on the reactionof the soil, being determined by physiological basicity, and not byshortage of potash.Lime is also considered to increase the supplies of potash to theplant by breaking down the complex insoluble compounds in thesoil, but here there are other and more important actions as well,in particular the neutralisation of acidity in the soil and theimprovement of the physical condition of the clay.Limestone alsoserves, but in this case much depends on the size of the particles.The finer the grinding, the greater is the activity. I n practice,however, there is no advantage, and some disadvantage, in goingbeyond the sieves having 60 to 80 meshes t o the linear inch.88The action of sodium and magnesium salts on wheat has beentested in the Woburn pot-culture e~periments.~g I n each case, theeffect depends on the anion. Magnesiuni oxide had previouslybeen shown to cause a marked increase in the nitrogen content ofthe grain; magnesium sulphate did not have this effect, althoughit caused an increase both in grain and in straw; the chloride alsocaused an increase a t low concentrations, but proved toxic a t higherconcentrations.Sodium compounds behave in similar manner ; thehydrate and carbonate increased the crop and also the percentageof nitrogen in the grain; the chloride gave a t low concentrationsan increase and a t higher concentrations a decrease, whilst thesulphate gave the increase only. These results are similar to thoserecorded on p. 212; they differ, however, from the water-cultureresults obtained by Breazeale.90The calcium phosphates, both natural and artificial, have con-tinued to receive attention. It is shown91 that tricalcium phosphateand hydroxyapatite [ (Ca3P,08)3,Ca(OH),] are the only two phos-8 6 E.Blanck, Fiihlings Landw. Zeit., 1916, 65, 441 ; A . , i, 624.I6 J. Stoklasa, Oesterreich,. Zeitsch. ZuckerintE, 1916, 45, 42 1.87 0. Nolte, J . Landw., 1917, 65, 6 7 ; A., i, 624.88 N. Kopeloff, Soil Sci., 1917, 4, 19.J. A. Voelcker, J . Roy. Agric. Soc., 1917, 77, 251.J. F. Breazeale, J . Agric. Research, 1916, 7, 407; compare alsoH. Bassett, jun., P., 1917, 111, 620; A . , ii, 413.F'. B. Headley, E. W. Curtis, and C. S. Schofield, ibid., 1916, 6, 857214 ANNUAT, REPORTS ON THE PROGRESS OF CHEMISTRY.phates which can exist in statble equilibrium with an aqueous solu-tion a t 2 5 O , and probably a t other temperatures also.It is furthersuggested that bone phosphate is a mixture of hydroxyapatite ant1calcium carbonate with small quantities of adsorbed hydrogencarbonates of sodium, potassium, and magnesium. The mineralphosphates have also been discussed and a series of constitutionssuggested, based on the proportions of calcium and phosphorus insuccessive extracts and also on the changes observed on heating t h ephosphate.92 Artificially prepared phosphates have been esamine(1and their solubility in citric acid demoiistrated.93Plant Growth.It is well known t h a t germination goes on best in pure water;dissolved substaiices usually cause a retardation, and a t higherconcentrations inhibit germination. The limiting concentrations ofnon-toxic salts which just prevent germination show an interestingrelationship.When expressed in gram-molecules per litre, theywere, for sucrose, sodium chloride, and potassium f errocyanide, as1 : 2 : 5, these numbers being also proportional to the number ofions formed by dissociation.94After germination, the seedling usually has a sufficient supply ofnutrient from the reserves stored in the seed to allow growth to goon for some tJme. Thus when peas are put into ordinary distilledwater prepared in glass vessels, they will germinate and make con-siderable growth without further additions. If, however, theexperiment is made in quartz vessels with very pure water distilledinto a quartz condenser and receiver, then growth very rapidlystops, and the roots are glabrous and not hairy.95 The view thatpure water is toxic could not be sustained; it was shown t h a t thestoppage arose from the circumstance t h a t seedling growth is limitedby the amount of calcium present.The reserves of calcium in theseed are only small, and as pure water stored in quartz vessels isfree from calcium, it does not allow of further growth. Distilledwater, however, dissolves out sufficient. calcium from ordinary glassvessels to keep the plant going for some time.Sodium chloride and ammonium sulphate produced much smallereffects, which were traced to the liberation of calcium from theenvelopes of the grain. Curiously enough, however, excess ofcalcium also prevents the formation of root hairs on Lepicliuwz92 G. S.Robertson, J . Agric. Sci., 1916, 8, 16.93 A. A. Ramsay, ibid., 1917, 8, 277 ; A., ii, 413.9 4 P. Lesage, Compt. rend., 1917, IM, 639.9 5 L. Maquenne and E. Demoussy, ibid., 979 ; 165,45 ; A., i., 53AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 2 I 5s(itivunz (ordinary cress).gG It is suggested that this is an intoxica-tion effect.The circuinstaiice t h a t the shortage of calcium in the seedseriously limits growth unless i t is made good lends some colour t oan Italian suggestion for manuring the crop by soaking the seedin solutions of the nutrient salts rather than applying these saltsto the soil as manures. It is claimed t h a t the plant has most neetiof the salts during the early periods of its life, and therefore thatthey should be supplied a t the outset so t h a t they can be absorbeda t once97 without risk of loss.It is claimed that considerableimprovement in crop production is obtained thereby, but no greatnumber of experiments has yet been made.I’hint Growth.-Few problems in connexion with the growth ofplants have been more frequently investigated than the possibilityof root excretions. I n the earlier days, plants were supposed to beanalogous t o animals, and excretions from the roots were assumedas a matter of course; this view has always remained popularamong practical men. Later on, when the soil was regarded as amineral mass and the changes going on were considered to be purelychemical, it seemed natural t o suppose t h a t the root excretionsshould be acid and should dissolve some of the soil substances forthe use of the plant.Still later, when it was recognised that thesoil was the abode of vast numbers of organisms, bringing aboutthe most varied changes, the necessity for assuming root excretionsdisappeared, and a more critical investigation of the evidenceseemed to show that nothing more than carbonic acid was involved.As the well-known experiment on colouring of litmus paper or thecorrosion of marble by plant roots is ordinarily done, the roots runconsiderable risk of being broken, when, of course, some of the acidsap may exude.98 The experiment has therefore been repeated bygrowing plants in gelose coloured blue with tournesol. A rosecolour is duly produced, showing that’ the medium becomes acid,and under the conditions of the experiment there is no possibilityof root fracture.The action is not, however, confined t o root hairs,as was formerly supposed; it extends to all the surface cells of thebark, both in the hairy and the glabrous regions; i t begins directlythe root is formed and continues all through the life of the plant.The author suggests, b u t without offering proof, that the acid ismalic acid.One of the difficulties in the way of accepting the view that plantroots excrete any quantity of acid is the circumstance that the96 H. Coupin, Compt. rend., 1917, 164, 041.97 C. Rossi, “ Nuovo process0 per la, cultivazione dei cereali,” Milan, 1917.gR H. Coupin, Compt. rend., 1917, 165, 564216 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.water or sand used as the medium tends to become alkaline aftera time.It is shown99 that plants vary in this respect; yellowlupine (Lupinfus Juteus), and to some extent buckwheat and hemp,accumulate no bases in the solution, but tend to make i t acid,whilst Camelim sativa leaves an alkaline residue which injures thecrop if it accumulates. From the narrow point of view of techniquethis is interesting, because i t indicates that modifications of theformula for a culture solution which hinder the accumulation ofbases in the solution during plant growth are likely to be beneficial.From the broader, physiological point of view the observationsafford interesting evidence of the kind of interaction taking placebetween the plant root and the soil solution.The changes in reac-tion are not necessarily due to root excretions, but might be causedby selective absorption; certain ions are more needed than others,and are therefore t'aken u p t o a greater extent, whilst those leftunabsorbed impart the reaction to the solution.Selective absorption does not, however, explain another set ofphenomena investigated a t the Woburn Fruit Farm. Plants suffervery considerable diminution in growth when they are grown i nsuch a way that the water supplied to them has had to come incontact with the roots of other growing crops.1The effect is quite general; it is produced by all the plants ex-amined. The water does not retain this toxic character for long,and if exposed to air the toxin is not only lost, but converted intosomething useful to the plant.Accepting the obvious explanationthat the roots excrete a toxin, it appears to be necessary to sup-pose, further, that a plant is a t least as much affected by its owntoxins as by those produced by its neighbours. Plants grown inpots divided up into compartments, so that each individual rootwas kept distinct from its neighbour, made no better growth thanplants grown in undivided pots, where the roots of the differentplants mingled freely. Further, within certain limits as t o distanceapart, the weights of the plants obtained are inversely proportionalto the bulk of the soil in which they grow, or, in other words, thetotal plant growth is the same whatever the number of plants.Pot experiments made a t Rothamsted2 show that wheat grown alongwith poppy, black bent, or spurry made better growth per in-dividual plant than wheat grown alone (the total number of plantsper pot being kept the same); thus, the individual wheat plantsuffered less from the presence of the weeds than from an equalnumber of wheat plants.*O E.A. Gemtchoughenikov, Reports Moscow A@. Inst., 1916, 10, 337.S. U. Picliering, Ann. Bot., 1917, 31, p. 181.Miss W. E . Brenchley, New Phytobyist, 1917, 16, 63AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 217When the amount of space per plant becomes coiisiderable aiidsufficient care is taken to eiisure soil aeration, very good growthbecomes possible. Methods have been suggested for increasing thegrowth of wheat on the large scale by allowing more space perplant and repeatedly cultivating and earthing up.3It is well known that plants generally take up their nitrogenin the form of nitrates from the soil; they can utilise other com-pounds, including ammonium salts, but they usually thrive best 011nitrate. Maize, however, takes up various organic nitrogen com-pounds and also sulphate of amn1oiiia, and with some of these, in-cluding sulphate of ammonia, it is said to make better growth thanwith sodium nitrate.4 Ammonia absorbed in this way is supposedto be transformed into asparagine, which is then converted intoprotein.Some plants, barley, maize, pumpkin, etc. , readily takeup ammonia and effect the conversion ; 5 others, such as peas aiidvetches, only assimilate ammonia in the presence of calciumcarbonate; whilst others, such as lupine, will not take up ammoniaa t all, even in presence of calcium carbonate.It is suggested thatthis difference is due to the different quantities of carbohydratesa t the disposal of the plant; by increasing or diminishing theamount of carbohydrate, it is possible to pass from one type toanother. I n a state of inanition, the faculty for forming asparagineis lost; with plentiful supply of carbohydrate, on the other hand,even plants of the lupine type did not suffer from ammonia, butconverted it into asparagine. An interesting difference is thusbrought- out between plants and aiiimals. The animal organismcan protect itself economically against the bad effect of ail accumu-lation of ammonia by excreting i t as urea in which the carbon isfully oxidised, so that no calories are lost.This simple plan is uof,however, open to the plant, should an accumulation of ammoniaarise through derangement of the normal protein synthesis orbecause ammonium salts are offered direct to it. The plant cannotexcrete ammonia, but, being better supplied with carbohydratethan the animal, i t can afford the luxury of making asparagine,which is richer in carbon than urea. Asparagine can accumulatein t'he plant without detriment, and can be built up into proteinwhen sufficient carbohydrate is present.On the other hand, if for any reason the plant is insufficientlysupplied with carbohydrate, these conditioiis no longer obtain ; i t isthen worse off than the animal, because it, has no mechanism whereby'I* K.0. Brighatti, Soil Pci., 1917, 3, 155; -4.. i, 374.11. Devaiix, Compt. r o d . , 1017, 164, 191.D. N. Prianichnikov, Mo.scow A p i c Instit., 1916, 10 ; Bull. Ayric.l n t e t i . Rome, 1017, 8, 204; A., i, 616218 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the ammonia can be excreted ; accumulation may produce disastrouseffects. It is not difficult to imagine conditions in which thismight happen. The common mosaic disease of tobacco, the causeof which is not yet understood, may be a case in point; as amatter of fact, ammonia has been found in tissues affected by thedisease, although it is absent from healthy tissuea.6 I n this case,it is suggested t h a t the ammonia may arise from the reduction ofnitrate, since nitrites were also found.Normally, this action isprevented by the oxydases, but it goes on when the plant is infectedwith nitrate-reducing organisms, and not only yields ammonia,which is toxic, b u t it also reduces the amount of nitrogen avail-able for useful purposes in the plant.I n discussing the transformation of nitrogen compounds in theplant, it is unsafe t o confine attention solely t o the ammonia,amino-acids, and proteins. Another group of compounds, thecyanogenetic glucosides, is widely distributed in plants, and onemust also consider the possibility t h a t hydrogen cyanide is in someway involved in protein formation. The synthesis7 of mandelo-nitrileglucoside, sambunigrin, and similar plant constituents fromethyl mandelate and ammonia is therefore of considerable interestas showing the possibilities of converting ammonia into a cyano-genetic glucoside.The carbohydrate constituents of plants come in for a good dealof investigation.Various sugars occur in the leaves, and furtherdeterminations of their amounts have confirmed the justice ofthe view p u t forward by XI. T. Brown, and supported by W. A.Davis and others, that the first product of assimilation issucrose .8The more complex carbohydrates have proved more difficult tostudy, and some of them are only vaguely characterised, because oftheir insolubility or their colloidal properties. Further studieshave been made of the pectin substances, which are important con-stituents of the carbohydrate group.The method of extractionhas been improved: and evidence is adduced t o show t h a t thepectin of the cell membranes of plants is a calcium magnesium saltof a complex anhydro-arabino-galactose-methoxy-tetragalacturoriicacid.10 The pectin of wood, however, appears t o be different;ll theP. A. Boncquet, J . Amer. Chem. SOC., 1916, 38, 2572 ; A . , i, 74 ; P. A.A., i , 683.E. Fischer and M. Bergmann, Ber., 1917, 50, 1047 : A., i , 657.Boncquet and Mary Boncquet, ibid., 1917, 39, 2088 ;8 W. Cast, Zeitsch. physiol. Chem., 1917, 99, 1 ; A . , i , 433.0 S. B. Schryver and Miss D. Haynes, Biochem. J . , 1916, 10, 539; A . ,lo F. Ehrlich, Chem. Zeit., 1917, 41, 197: A., i , 321.l1 T.von Fellenberp, Mitt. Lebensm'ttelunters. Hyg., 8,_1 ; A., i, 61 6.i , 245AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 2 19problem has been studied by measuring the quantity of methylalcohol yielded on decomposition.From a study of their electrical properties, it has also beensuggested t h a t the pectin substances, besides acting as the bindingmaterial of plant tissues, constitute a means for regulating thecontent of hydrogen- and hydroxyl-ions in the circulating fluids ofthe tissues and maintaining the cell contents in a slightly acidcondition; they form a reserve of insoluble acid which is, never-theless, readily available for the neutralisation of any alkalinesubstance brought into contact with the cell .I3Other constituents of plants have also received attention ; a iiewiiiethod of testing for flavones has been described, and in view ofthe results obtained,13 i t is suggested that these substances serveto absorb ultra-violet rays of sunlight and protect the living proto-plasms from their injurious action.The methods of detecting carotinoids have also been studied.I4An investigation on solanine from potato shoots indicates t h a t theformula is CjzH91018N, and t h a t on hydrolysis i t yields equi-iiiolecular proportions of dextrose, galactose, rhaninose, andsolanidine, to which the formula C,,H,70,N is assigned.Thedevelopment of Molisch's microchemical methods has extended thenumber of known plant con~tituents.~5Attention has been devoted to the variation in composition ofplants with variations in the conditions of growth. It is wellknown t h a t the seed is only slightly alterable in composition, andin particular that changes in manuring and in culture have onlya small, and from the practical point of view almost negligible,effect.Seasonal factors are more potent, and attempts have beenmade t o reproduce them by artificial changes in water supply. Aprolonged investigation of the composition of wheat grown underdry farming and under irrigation in Idaho16 has, however,revealed no differences between varieties grown under these verydifferent moisture conditions. Each variety keeps its own charac-teristics regardless of the changes in conditions of growth. Theonly practicable method of altering the composition of the wheatgrain appears t o be to carry into one variety the properties andconstituents of another, which can be done within certain limitsby suitable breeding methods.S.OdBn, Int. Zeitsch. ph?ks. chem. Biol., 1917, 3, 7 1 ; A . , i, 436.K. Shibata, I. Nagai, Ftnd 31. Kishida, J . Biol. C'hein., 1916, 28, 0 3 : A . ,i , 107.l 4 C. van Wisselingh, Flora, 1917, 177. 371 : A . , i i , 554.l6 H. Molisch, Ber. Dezit. t o t . Oes., 1916, 34, 154 : 1917, 35, 99: A . , i , 695,l6 J. S. Jones and C. W. Colver, Idaho Agric. E q t . Sta. Bull., 88, 1916.506, 607220 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The vegetative parts of the plant, however, are more susceptiblet o variation in composition, although here again the essentialfunctioning materials of the plant may remain uniform in com-position, whilst the variations in the whole plant may be due tothe precipitation of substances that have been absorbed, but, arenot ueeded,17 or t o a variation iu size of the storage vessels allow-ing greater accumulation of storage products.The classicalinstance is afforded by the sugar-beet. By growing seed oiily fromthe roots richest in sugar, the Germans have steadily increasedthe percentage of sugar in the ordinary crop. The French chemistshave now obtained as good results as the Germans.'*These and other instances have satisfied practical meii t h a t thecomposition and quality of crops can be altered fairly consider-ably. There are, however, limits beyond which change does notgo which are not' always clearly recognised.Thus the orangegrowers of California consider that large dressings of ammoniumsulphate sweeten the fruit, and t h a t potash increases the acidity;chemical analyses do not bear out these views.19One of the difficulties of the investigation is the number ofvarieties and sub-varieties of the different plants. I n comparingone plant with another, the greatest care is necessary to ensuret h a t the two are really comparable. Whether the botanical differ-ences are associated with chemical differences is not yet clear ; thework is so far only in the early stages. As an example, the proper-ties of millet specially adapted to a dry climate are being studied,and although the work is as yet still in the botanical stages, itpossesses considerable interest for agriculturists.20Differences in composition of different.varieties are, of course,oiily to be expected, and whilst nothing very definite has yetemerged, some few observations have been made, which, however,require careful investigation. Thus it is stated 21 that the com-position of the essential oil varies according to geographical posi-tion, even with plants of the same species; the iodine number(which indicates the relative proportions of the triglycerides ofoleic, linoleic, and linolenic acids respectively) increasing as the1 7 A few attempts have been made to trace the means whereby the $antdisposes of non-essential materials presented to the roots and taken upby them.Saligenin appears to be transformed into salicin, quinol intoglucoside. G. Cinmician and C. Ravennn, Ga-xetta, I91 7, 47, ii, 99 ; A ,i , 681.18 E. Saillnnl, Compf. r e d . , 1017, 165, !318.l9 H. D. Young, J . Agric. Resecwc?t, 1917, 8 , 127.20 C. A. Bielov, Pctroyrad. Bd1. oJ Applied Botqny, 1916, 9, 333 ;21 G. V. Pigulevski, ,T. Rms. Phys. Chem. SOC., 1916, 48, 324 ; .4., i , 189.Birll.Agric. Intell. Rome, 1917, 8, 1093AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 221geographical distril>utioii of the plant extends Curther to thoiiorth.It is iinportaiit, for the plaiit that sonie a t least of the reactionstaking place i n its cells should proceed rapidly, and as i t cantolerate neither rise of temperature nor increased concentrationof the sap beyond certain limits, the activation has to be broughtabout by catalysts.The enzymes of the cell are therefore extremelyimportant. Of these, oxydases have received a good deal of atten-tion. They are stated2z to increase as the plant is improved bycultivation and selection. In the case of the Japanese niecilar, forexample, the iniproved variety, with its longer biological cycle andlonger, larger, sweeter, and less acid fruit, is, under equal condi-tions, richer in oxydases than the less cultivated variety withshorter biological cycle, and fruit which is round, small, moreacid, and less rich in sugar. In other cases also the amount ofoxydase was found to be inversely related to the amount of acidand directly related to the quantity of sugar present.It is furthersuggested t h a t the increase in the amount of oxydase in the culti-vated varieties may be associated with the additional supply ofnitrogen in the soil resulting from the use of additional fertilisers.7'7nnt ~'oisons.-Studies of the effect of coal gas on plants 23have shown that gas itself is harmful a t certain concentrations, butthe poisonous constituent is neither carbon monoxide, ethylene, noracetylene; i t was not identified with certainty. Cress was muchless sensitive than tomatoes, salvia, and other plants.34Poisoning from copper is reported from a copper tailing regionin the United States. Most of the flora of the district seem t ohave been destroyed, and among the larger shrubs only the wildrose flourished.The surviving plants contained i n their tissuesappreciable quantities of copper, arsenic, antimony, and tin, asmuch as 0.62 per cent. of copper being present25 in some cases.Diseased leaves of citrus trees affected by mottling have beenexamined, b u t no great amount of information has been obtained.They contained on the average more calcium, magnesium, antiphosphorus than healthy leaves,26 which seems t o indicate somefunctional derangement, but' throws no light on its nature.22 A. Degli, Annuli della R. Scimlo Sup. di Agric. Portici, 1917. 14.23 C. Wehmer, Ber. Deut. hot. Ges., 1017, 35, 4 0 3 ; A . , i., 618.2 4 illifis S. L. Doubt, not. Gux., 1917, 63, 209 - A . , i, 619.25 W. G. Bateman, and L.S. Wells, J. Amer. Chem. SOP., 1917, 39, 81 1 ;A.. i, 372.C. A. Jenssn, J . Agric. Research, 1917, 9, 157, 253222 ANNUAT, REPORTS ON THE PROGRESS OF CHEMISTRY.Feedivg Stuffs.Although the physiological aspects of animal nutrition are moreproperly discussed in another section, reference may be made hereto certain agricultural applications of some of last year's work.The War has reduced the supplies of certain hitherto widelyused feeding stuffs and brought into prominence others less knownin this country. Palm-nut cake is one of the most importailt ofthese, and i t has formed the subject of several interesting investi-gations a t Leeds. It is more digestible and contains more foodunits than undecorticated cotton-seed cake,27 and it comparesfavourably i n keeping qualities with other cakes.'* Apparentlyits f a t does not pass as such into the milk of the cow, but is sub-ject to some selective action, the acids of lower molecular weightbeing transferred in greater proportion than those of higher mole-cular weight; further evidence is needed, however, before this canbe regarded as definitely established.29Dried yeastappears to be distinctly promising, and it proved as digestible asany food on the farm.30 Horse chestnuts have been studied bothin France and in Germany.The older attempts to utilise themfailed, because the cost of collection was too great. Further, theshell causes a good deal of trouble; it can be removed withoutdifficulty in the fresh state, but i t adheres to the cotyledoqous masswhen dried.Moreover, the shell contains both aesculin and atannin known as zesculitannic acid. The dry, cotyledonous part isvaluable; it contains 20 to 30 per cent. of starch, 6 to 7 per cent.of nitrogenous matter, and 2 to 3 per cent. of fat, b u t no zsculinor tannin. It contains, however, a saponin, which has a markedphysiological action on the blood system, and therefore it cannotbe used direct for cattle feeding. This substance can be washedout with l/lOOO-hydrochloric acid, and no doubt with other acids;20 to 25 per cent. of a beautiful, white, tasteless and odourlessstarch, which can be extracted and used for alcohol or even food,whilst the residue can serve as cattle fo0d.31Although the German methods of treatment of horse chestnutshave not been divulged, they are evidently considered satisfactory,Other possible feeding stuffs have been examined.27 C.Crowther and H. E. Woodman, J . Ayric. Sci., 1917, 8. 429.28 W. Godden, ibid., 419.29 C. Crowther and Miss H. Woodhouse, ibid., 451.3O C. Crowther and H. E. Woodman, ibid., 448.31 A. Goris, Compt. rend., 1917, 165, 345 ; see also P. Dechambre, Compt.rend. Acad. Agric. de France, 1917, 3, 926AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 223as no less than 150 marks per ton is paid for them.Sz Acorns areconsidered even more valuable, their price being 190 marks perton. It is said that cattle food is being made in Germany fromwood meal, heather meal, and certain lichens. It has been shownin this country that’ both acorns and horse chestnuts yield a con-siderable quantity of alcohol on fermentation, some 145-164 litresof absolute alcohol per ton of nuts as picked.33Experiments have been made in Germany with certain newfoods and substitutes-‘‘ Ceralis,” “ Maizena,” ‘‘ Kornerblutfutter,”etc., the composition of which is not indi~ated.3~ It has beensuggested in America that insects might make good food for poultry,especially as the van Slyke method shows that the protein of grass-hoppers and “June bugs ” is similar to that of very tender roastbeef or breast of turkey.35More complete studies have also been made of the ordinary feed-ing stuffs of the farm.The potato is being exalted as humanfood, Hindhedes’s older *demonstration of the high nutritive valueof its nitrogen compounds being supported by more recent deter-ininations.36 Wheat, on the other hand, is shown to be an iii-complete diet for animals (like most other single foods); the“deficiency” effects are seen not only in the animal, but also i nits offspring.37 Maize deficiencies ” have also been studied,38 andthe question is raised whether lysine is the limiting amino-acid inits protein.Lastly, serious attempts are being made in Germanyto improve the feeding value of straw by digesting it with dilutesodium hydroxide s0lut~ion.39The old problem of silage fermentation has received furtherattention. It is now generally recognised that the changes arebrought about partly by the enzymes of the plant and partly bymicro-organisms.Determinations of the rates of the variouschanges have shown that the production of acid is expressible bypeaked curves similar to those often given by bacterial actions,whilst the hydrolysis of the proteins and the evolution of carbon32 Borgmann, Tharandter Forst. Jahrbuch, 1916, 67, 367 ; atis. in Rz~ll.4gric. Intell. Rome, 1917, 8, 1127.33 J. L. Baker and H. F. E. Hnlton, Analyst, 191 7,42, 351.32 A. Richardsen, Landw. J . , 1916, 49.36 M. S. Rose and L. F. Cooper, J . Riol. Chem., 1917, 30, 201 : A . , i, 52.4.37 E. 13. Hart,, E. V. McCollum, H. Steenbock, and G. C . Humphrey, J .Agrdc. Research, 1917, 10, 175 ; E. V. McCollum, N. Simmonds, and W. Pitz,J . Biol. Chem., 1916, 28, 211; A., i, 184.38 E. V. McCollum, N.Simmonds, and W. Pitz, J . Biol. Chem., 1916, 28,153; A., i, 192; J . Bbl. Chem., 1917,28, 483, A., i, 185.39 Deut. Landw. Presse, 1917, 44, Ncs. 2, 4, 8, 9, 16 ; Illustr. Landut. Zeit.,1917, 37, Nos. 3 and 4 ; and Wiener Landw., Zeit., 1917, No. 5229.J. 8. McHargue, J . Agric. Research, 1917, 10, 6332% ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.dioxide are expressible hy amootli curves resembling those ofteiishown by enz y in es .40Mannitol is said t o be one of the products of the decompositionof the sucrose, although after a few days i t suffers de~omposition.4~Milk .The distribution of the fatty acids in the milk f a t of the cowand the sheep has been determined.42 It has been shown t h a t therate of increase of the growth of lambs is related t o the milk yieldof the ewe.43Perm e n t n t ion .It has been shown by Buchner and Albert that yeast on treat-ment with acetone yields a white powder capable of fermentingsugars. This material, known as zymin, owes its fermenting powerto two constituents (or groups of constituents), each necessary to thework of the other, known respectively as*the enzyme and the co-enzyme.The latter can be washed out with water; the residual“ washed zymin” is then inert towards sugar. The extract has beeninvestigated, but the precise active agents have not been absolutelydetermined. Phosphates were shown by Harden and Young t o beessential, b u t not the sole agents. When, however, potassium pyru-vate is added as well as the phosphate, the power of effecting ferment-ation is completely restored .44 The addition of acetaldehyde andpotassium or ammonium phosphate, b u t not sodium phosphate, hasthe same effect.These observations are interesting in connexionwith a hypothesis, favourably regarded by many investigators, thatacetaldehyde is an intermediate product in alcoholic fermentation,being reduced to alcohol by hydrogen liberated a t a previous stageof the process. The acetaldehyde is thus supposed t o start thereaction by ‘‘ accepting ” the hydrogen. Whether or not acet-aldehyde is the co-enzyme cannot, of course, be stated withoutmore exhaustive investigation of the extract ; some other reduciblesubstance might play the same part. The investigation has, how-ever, carried the problem a distinct stage further by proving thenecessity in the co-enzyme of phosphates, potassium or ammoniumions, and acetaldehyde or some similar substance.40 A. R. Lamb, J. Agric. Research, 1917, 10, 361 ; see also 0. W. Hunter,41 A. W. Dox and G. P. Plaisance, J. Amer. Chem. ~S‘oc., 1917, 39, 2078;42 C. Crowther and A. Hynd, Biochem. J., 1917, 11, 139; A . , i, 608.43 E. G. Ritzman, J. Agric. Research, 1917, 8, 29.4 4 A. Harden, Biochem. J., 1917, 11, 64 ; A . , i, 501.ibid., 75, and C. 0. Swanson and E. L. Tague, ibid., 275.A., i, 683AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 225is well kllow11 that yen.;t juice contailis x powerful digestiveeilzyllle of the trypsin type, and i i i consecjuellce that i t steaclilyloses its albumin on keeping. This enzyme can also bring aboutthe decomposition of polypeptides, but the change is co~nplex,depending not only as to its rate, b u t also to some extent as t o itsnature 011 the conditions of the experiment.45 The effect of thehydrogen- and hydroxyl-ion concentration was studied in somedetail, but i t was recognised that other factors came in as well,some of which were rather indefinite, such as the unexplained con-dition of the ferment. The enzyme is most stable with a hydrogen-ion concentration of about, 3 x 10-7. The resulting ainino-acidsretard further decomposition. The results indicate a similarity inaction with that observed by Bredig on inorganic ferments, andthey do not necessitate the view that the ferment is activ2 onlytowards a definite grouping of atoms.The nutrition of the yeast plant is of enom~ous practical interestnowadays, in view of the circumstance that yeast is capable ofserving as food for human beings and for animals, and t h a tit can rapidly synthesise protein from inorganic nitrogen orfrom carbamide. Circunistant8ial accounts are received fromGermany of the successful production of considerable quantitiesof food in this way. Organic acids (citric, acetic, tartaric),glycerol, asparagine, mannitol, and carbohydrates, includingin suitable circumstances the pentosans, can all serve as sources ofcarbon.46 Where sugar is used, the weight of yeast can be increasedcoiisiderably by the addition of suitable quantities of gum arabic,rye gum, or the humic substances of The effects of frac-tional additions of sugar, of added alkali, and of nitrogen nutrienthave been studied.4* Instead of amnioniuin salts, other nitrogencompounds can serve, including pyridine, piperidine tartrate,con i n e , nicotine , cinch o nic acid , qui n i 1 I e , br u c i ne ~ coca in e , a 11 timorphine, but these are of less practical interest .49It has been suggested that the fermentation of sugar by A . c ~ w -.f/i/Ztl.v nigw is an oxidation proceeding in three stages, producingcitric, oxalic, and carbonic acids respectively, and by regulating theconditions it has been found possible to check the reaction a t thefirst stage so as to obtain a considerable yield of citric: acid.50E. J. RUSSELL.4 5 E. Abderhalden and A. Fodor, Fewnentforschung, 1916, 1, 5 3 3 ;47 L. Lindet, Compt. rend., 1917, 164, 58 ; A . , i, 188.48 T. Bokorn~, All{/. Brau. Hopfen. Zeit., 1917, 57, 447 ; A . , i, 681.49 F. Ehrlich, Biochem. Zeitsch., 1917, 79, 233 ; A-., i, 309.50 J. N. Currie, .I. Riol. CfIm., 1917 31, 1 5 ; A . , j, 614.n., i, 306. 46 T. Bokorlly, Miinch. Med. Tl'och., 1916, 63, 791 ; A . , i, 72.REP.-VOL. XIV.

ISSN:0365-6217    

DOI:10.1039/AR9171400197

出版商:RSC    

年代:1917

数据来源: RSC

摘要:

CRYSTALLOGRAPHY AND MINERALOGY.‘;THE two years that have elapsed since the last Report have beelllnarked by a great diminution of published researches, especially ofthose we could ill dispense with. This is o d y to be expected, sincethe energies of man17 workers are now directed in other channels.I n such times as these, it is no easy matter either to collect thebricks or to erect those that are shapely into an orderly structure,so t h a t a certain degree of indulgence may well be claimed of areader. A brief estimate of general tendencies and results willserve as an introduction t.0 the systematic discussion of details.The X-ray methods of investigating niolecular structure havebeen fundamentally extended by Debye and Scherrer,* who havedevised a method of experimentation which is not merely applic-able to a crystal-aggregate (say, a graphite pencil), but even toordinary liquids.Unfortunately, these publications are not atpresent accessible for detailed study, so that a full appreciationof this remarkable advance must be postponed. It may, however,be stated t h a t the authors have deduced the crystal structure ofgraphite and the molecular dimensions of the liquid benzene mole-cule! The former proves to be rhombohedral; the absolutedimensions of the rhombohedral cell ( a = b = c) are 4.48 x 10-8 cm.,* The former title of this Report (“ Mineralogical Chemistry ”) wasinitially adopted on the principle that Reports should as far as possiblefollow the main divisions into “ Abstracts.” It is, however, manifestlyimpossible for a Reporter on “ Mineralogical Chemistry ” to adopt thiscounsel of perfection: in the first place, because the centre of gravity ofmineralogical research has shifted from chemical analysis to the investigatior!of mineral problems from the point of view of physical chemistry ; and,secondly, because the main results of crystallography are spread over thephysical, inorganic, and organic abstracts.The present title is a com-promise between “ Mineralogical Chemistry ” and “ Crystallography ” *it is, perhaps, satisfactory as not being altogether at variance with the subject-matter discussed-an objection which has been good-humouredly lodgedagainst the present writer’s previous Reports.1 P. Debye and P. Schemer, Nachr.Ges. Wiss. Qdttingen, 1916 ; PhysiLaZ.Zeitsch., 1917, 18, 291 : A , , ii, 437 ; compare also S. Kyropoulos, ZeitRchonorq. G h n . , 1917, 99, 197; A . , ii, 468.22227 CRYSTAL1,OCIHAPHY AND MINERALOGY.which gives ~ l , ~ ~ = 3 . 4 1 x 1 0 - 8 cni., a value agreeing well wit11l<ragg‘s l>yeliinil1ary deteriiiiliatioii .? The iiiolecule of I ) e ~ z e ~ l efulfjls lllost clielllibal expectat jotis ; its for111 is that of r e g ~ l a rllexagoll, with a11 edge-dilneilsioii equal to 6.02 X all(l a “ thick-lless ” of soinething under 1.19 xRle11tion may well be made here of the publication of a seriesof papers by Fedorov, who has niade a critical study of w. 13. andW. L. Bragg’s results.Apart from the above, the progress of X-ray investigation is ofa mixed character.Our most notable _Y-ray analysts3 have un-doubtedly unravelled t.he intricacies of some point systems, andhave thereby laid the foundations of a crystal-structure of pre-cision; but there \\oulcl seeiii t o Ile sigtis that it would be moreprudent to devote some tiine to the examination of two funda-mental properties, uamely, the falling away of reflection-intensitywith increase of order,” and the quantitative relationship betweenreflection-intensity and atomic mass or number, than t o addanother reconstruction or two to the present list. After all, thefuture reconstructions of crystal edifices ultimately depend on thesetwo fundamentals, and the investigation of the simplest possibleisoinorphous groups (especially the group rubidium chloride,bromide, and iodide) would go f a r to standardise these pointsd’appui. In any case, numerous crystalline substances have nowbeen thoroughly investigated, and i t is possible to estimate thedegree of cogency of some previous beliefs; both topic-axes and theBravais principle have received a measure of support.On theother hand, the question of the existence or nonexistence of rnole-cules in a crystal, although actively discussed, has, perhaps notunnaturally, made no headway.The appearance of the fourth volume of Groth’s ‘‘ ChemiseheK r y s t a 1 1 og r ap h i e , ” isannounced.A certain degree of interest is attached t o the first example ofa medical application of crystallo-chemical analysis . 4 Theidentification as salol (pheiiyl salicylate) of a crystal of i11testinalol-igin presented no difficulties, and was, i n fact, effected in sixty-five minutes.Steady progress has been made in the examination of silicateequilibria by the American Geophysical School.To quote Bowell :‘ I It is not long since the discussion of the theory of the crystal-lisation of igneous rocks was carried out by describirlg the crystal-de a 1 i ng with m on oc y cl i c c o m p o u 11 d s ,H- and W. L. Bragg, “ X-Rays and Crystal St,riictiire,” 174.W. H. Bragg, T., 1916, 109, 25,”.7’. 1:. Barker, Lancet, 1917 ( J k y 26th), 7082’28 ANKUAI, REPOH‘I’S ON THE PROGRESS OF C‘HEMISTKY.lisatioll of sollle Sinlple bi1ial.y eutectic iiiixture, S U C ~ as saltwater, alld wiiidiilg.111) with the st atemetit that the crystallisatiollof the iglleous rock is i l l some tiieasiire aualo@~s.” Our know-ledge of silicate equilibria has now certainly advanced beyond thatstage, for the accurate investigations of Bowen and others havereached the point from which i t is possible to sketch the mainoatlines of petrogenesis ; the painstaking field observations ofgenerations of petrographers, leavened not merely by the priiicilllesbut also by the practice of physical chemistry, are rapidly givillgrise t o a science of petrology.The last topic to be discussed is crystal growth (and dissolution).The characteristic, plane-polyhedral form assumed by a growingcrystal is as pleasing to behold as i t is difficult to “explain.”Drops of a liquid, separating in a state of suspension from another,usually assume spherical forms-bodies having the least area for Rgiven volume.Not so crystals ; although isolated examples areknown partly or wholly bounded by curved surfaces, whilst others,owing to an all-round, richly faceted development, would seem toapproximate towards a spherical form, it is nevertheless certaitithat the most frequent styles of development are the thin plateor fine needle-shapes which are extreme examples of a maximumof area for a given volume. This “anomaly” Curie attempted toreconcile with the principle of minimum surface energy by assuin-ing that plane faces are developed because they have lowercapillarity constants than curved faces. His theory has beenexceedingly fruitful, for i t has stimulated research in a provincewhich otherwise might not have been explored.Recent work,however, has proved i t to be untenable for macroscopic crystals.Further, i t is not generally known that the problem had beenpreviously, and more satisfactorily, handled by Gibbs in his workon the Phase Rule. Gibbs, indeed, foresaw that the principle ofminimum surface energy might only operate in the case of micro-scopic crystals. The‘ present appears to be a suitable time toreview the problems of crystal growth, inasmuch as future work islikely to take other directions. The inverse question of crystaldissolution is even inore complex, but some regularities have beennoted.Generul R e s u l t s of X-Ruy Methods of Investigation.The most, efficient form of installation for the preparation ofS- radiograms has been discussed by Itinne.5 The employme~~t ofthe Lilienfeld X-ray tube is advocated as permitting a steadyF. Rinne, B e y .K . Suchs. Ges. lVis.g., [Math.-Phys. I<Za.we], 1915, 67,303CRYSTALLOGRAPHY AND MINERALOGY. 229stream of rays of any desired hardness. Analysis of a radiogralrlis shown to be most directly and easily effected by the help of agnomonic projection, from which the stereographic projection canbe readily obtained. Great care must be employed when adjustingthe crystal, otherwise a want of symmetry may appear in theradiogram (it is to this cause t h a t Rinne refers some anomalousresults obtained by Jaeger). The paljer is accompallied by amagnificent series of exposures, including cya1;ite (anorthic) ;diopside, epidote, scolecite, and sucrose (monoclinic) ; aiihydriteand aragonite (orthorhombic) ; calcite and dolomite (rhonlbo-hedral) ; quartz, carborundum, and beryl (hexagonal) ; cuprite androck-salt (cubic)-as well as others illustrating typical *‘ abnormali-ties.” Rinne’s elegant employment of the gnomonic projectioll isadmirahly illustrated by a basal exposure of anhydrite, which COIFtains no fewer than 424 spots, contributed by as many planesbelonging to 112 different crystal forins, most of which have neverbeen observed as actual faces.The astonishing accuracy withwhich such complex crystal planes as (66.5.30), (88.45.40),(42.65.30) register their positions on the photographic film maybe regarded as a most impressive demonstration of the orderlynature of crystal structure.The molecular structure of a mixed crystal has been investi-gated by Vegard and SchjelderupG by means of the X-ray spectro-meter.It is found t h a t the reflection angles of mixed crystals ofpotassium chloride and potassium bromide vary regularly with thecomposition as deduced from Fock’s solubility curves (the crystalswere not chemically analysed). The mixed crystal, then, behavesas a single individual, and cannot be regarded as an intercalationof two independent lattices.S-Ray spectra produced by curved crystal faces have been studiedby Cermak.7The chemical aspects of crystal-structure are being freely dis-cussed. I n the first place, it has been pointed out that Groth’sdenial of molecules is a t least premature, if i t is not clearlyerroneous.R Further arguments for the existence of molecules aregiven by Smits and Scheffer,g who suggest valency models for rock-salt and calcite.Other chemists draw an analogy between co-ordination and crystal-structure ; for example, Pfeiff er points outL. Vegard and H. Schjeldernp. Physikal. Zeitsch., 1917, 18, 93 ; A . ,ii, 243. P. Cermnk, ?:hid., lOl6, 17, 405, 556.A. Foclc, Ccntr. Mil?., 1916, 392; A., i i , 12!).A. Smits aiid F. E. C . Sclicffcr, Proc. K. Akurl. IVptpnsclt. Amstcrda?n,lo P. Pfeiffer, Zeitscli. anory. C’hern., 1916, 97, 161 ; A . , 1916, ii, 228 ;1916, 19, 432 ; A . , ii, 78.compare also P.Niggli, ibid., 1916, 94, 207; =t., 1916, ii, 300280 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.that rock-salt may be regarded as made tip of [NaCl,] and [ClNa,,].The chemical constitution of crystals is also discussed in Vegard'spapers, but other practising X-ray analysts leave such questionsseverely alone. Chemists naturally look forward to the adoptionof the idea of valency; crystal-physicists, on the other hand, haveso far eschewed any appeal to valency, perhaps because the appealwould, from their point of view, imply another assumption. I t is,however, possible that the appeal will ultilnateiy have to be madcin a case like sodium chlorate.The appearance of theoretical papers by Niggli,"? l 2 Johiiseii,'"Sc h o n fl ies , who discusses en anti om or ph ism, Beck en k a in p , I Tr a iidRiiiiie'G may be put on record.Pcdorov's C~iticcd Survey o f t h e 1I-oi.k of 11-.ff. c c u d11'. L. BI*ny!j.It itlust be remarked a t the outset t h a t the material used byFedorov is restricted to the well-known book '' S-Rays and CrystalStructure," a copy of which was sent out t o him as soon as pub-lished. The main results of his analysis are presented in fourpapers.17The first paper ("Results of the first stage of the experimentalinvestigation of crystal-structure ") is devoted to a critical surveyof Bragg's results from the point of view of his own contributionsto the theory of crystal-structure. Each crystal is studied indetail ; the structural parallelohedron and point-system-symbol aredetermined ; the various elements of symmetry (planes, glide-planes, axes, alternating axes, screw axes) are presented in theform of a structural diagram.I n this way, rock-salt, ammoniumchloride, cuprite, blende, diamond, fluorspar, calcite, dolomite,pyrites, zincite, and sodium ch1orat.e are passed in review. Nowthe experimentpal investigation of these suhstances was not attendedwith equal success; for example, W. H. and W. L. Bragg regardtheir investigations of ammonium chloride, cvprite, zincite, andsodium chlorate as incomplete. These cases are examined a t Pomelength. It is pointed out that atoms generally occupy favouredpsitiions in the structure; they are generally situated at pointswhich are the intersections of several axes and planes of symmetry,11 P.Niqgli. Bcr. I<. Sacha. &s. 1Vis.r.. [Mnth.- Phys. HlnmP1, 191 5 , 67. 364.l2 Idem, Cmfr. Mitz., 1916, 197 ; 1917. 313.IR A. Johnseii, i b i d . , 1916, 385.j 4 A. Schdnflies, Zeit.wh. K ~ , t / s t . A f i ~ . , 1916. 55, 321 :'6 J. Beckenkamp, Centl.. M i w , 1917, 97 : . 4 . , i i , 206.4 . , i i , 4-17.*F. Riiiiie (two papers covering inwh t h e same ground), Jnhrb. A'Mi?z.,1016, ii, 47 ; Zeitsch. anorq. Ohem., 1016, 96, 317 ; A . , i i , 18, 166.l i E. S. Fedorov, Bull. 4cacl. Sci. Petrogmd, 1916, 10, 359, 435, 547, 1675CRYSTALLOGRAPHY AN D hi1 N ERALOG Y . 231aud i t might be concluded therefrom that the syminetry of ailatom approximates to that of a sphere. This, however, cannotreally be true, because it is iiicompatible with the property of'valency, the operation of which must deform the atom ; moreover.the zinc atoms in zincite must be polar if they are t o account forthe undoubted hemimorphism of structure.These considerationsare held in view when Fedorov proceeds t o suggest suitable struc-t ures for ammoniuiii chloride, cuprite, and sodium chlorate. Theoptical activity of the last substance is fully discussed, and theauthor finds himself compelled to postdate asymmetry of the at 0111.In the second paper (which cont'ains some important correctionsto the first) Fedorov enunciates The fundamental law of chemicalcrystallography." Following is, perhaps, the most concise way ofstating the law: The whole of the atoms of a crystal are situateda t (some of) the nodes of a single, ultimate space-lattice.Variousdeductions can be made from the law. For example, it necessarilyfollows t h a t a plane passing through any three atoms is a possibleplane of development (face). Moreover, i f we take an atom asorigin, and three space-co-ordinates defined by the position of threeother atoms of the same composition not lying in a plane with it,then the position of any other atoms can be stated in the form ofco-ordinate numbers, which are small whole numbers or fractions.Thus, in the case of rock-salt, if the general co-ordinates of thesodium atoms are (000), the co-ordinates of the chlorine atoms are($00) ; for blende we have Zn($OO) and S(+, +, $) ; for ammoniumchloride, Cl(OOO), N(+, 3, +), €I($, +, 3) ; for sodium chlorate,Na(+, $, i), C1( - +,2,4,), O(tO0) ; for calcite, C(OOO), Ca( aOO),O(-I- 1 2 9 - ; 2 0), and so on.The author points out that as the lawimplies certain limitations 011 the possibIe positions of atoms, itcan be employed in the deduction of the probable positions ofatoms when the definite positions of others have once been settledby S-ray methods, and he is not afraid to amplify missing detailsin the structure of corundum and haetiiatite (in which amplificationsconsiderations of the centre of gravity of particular geometricalforms are relied on). Quartz and magnetite are also discussed withsome detail. Suitable structures are also suggested for the follow-i n g cul:, ic su 11 s t a nces : hexa m et h y 1 en e t et ram i t i e , t e t ram ethyl-pyrazine, garnet, and potassium silicofluoride.In the third paper (" The cheniical side of crystal-structure " ) ,Feflorov discusses briefly the coniiexioii between ntoinic conipositionant1 atomic tlista~ices.The main coiicliisioil (there :ire others) i \that relative contiguity of two atonls is iilvel*sely relatec1 t o i l l f Acheniical degree of similarity ; there is, however, A lilrlitatioll w i t hregard to bivalent atoms232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n the fourth paper (“A contribution to the problem of thedetermination of ntomic reticular densities in crystal planes ”), theauthor applies himself to a question, which is obviously of greatcrystallographic interest for the following reasons.U p to thepresent time, considerations of reticular density have suffered fromtwo disabilities : (1) a total absence of intimate, experimental know-ledge has always implied a purely theoretical treatment ; (2) thetheoretically possible point systems were relatively so complex thatmost crystallographers confined their practical attention to themuch simpler space-lattice-in the hope that they may possiblyultimately advance from the simple to the complex; with the con-viction t h a t the opposite, alternative line of procedure would leavethem permanently in the air. I n spite of the above disabilities,the study of reticular densities has been both suggestive andfruitful. It has suggested a consistent way (that is, a way governedby a principle) of restricting the infinite number of axial ratiosallowed by Haiiy’s law; i t has been one of the factors (but not theonly one) that has made it possible to apply crystal measurementsto the identification of chemical substances.Fedorov recognisesthat i t is now possible to study the subject of reticular densitieswith all exactness, and in the paper under review he discusses theproblems opened u p by atomic vistas. ( I t may be remarked,parenthetically, t h a t somewhat similar problems were treated in avery interesting way many years ago by Sohncke).Is Successiveparallel strata frequently differ greatly in reticular density, and ashe takes the’ view that the reticular density of the densest stratumcarries most weight in the determination of the external form ofthe crystal, Fedorov determines these highest densities.As inprevious work, the results are given in the form Az, where A repre-sents reticular density. All Bragg’s cubic substances are studied.‘:’l8 L. Sohncke, Zeitsch. Kryst. Min., 1887, 13, 214.* The above digest may be of some value, although I heReporterhasnot beenable to devote much time to the papers. Puhlished in a generally inacces-sible language, without anyFrenchrbsum6, they are as good as lost to WesternScience ; an English translation is imperative before they can ever receivethe attention they deserve. Professor Fedorov has published several otherpapers, but he has been unable to send separate copies owing to Russianpostal regulations of a temporary character.Cross-references, however,indicate that some of these papers are devoted to a further developmentof crystallo-chemical analysis. As mentioned above, X-ray work entailsmuch revision of some previous ideas. The Rcporter has made an examina-tion of the application of the Bravais principle (as employed before theadvent, of X-ray mcthods) to the new ntninic i*e-constrnctions, and finds thattho principle reveals the correct primttry spnce-lattico (that is the t hrwprincipal trnnslatioii rat ins of the wholc structure) in every case elucidatedby tlie X-ray analysts, but leads to erroneous conclusions in every possiblCRYSTALLOGRAPHY AND MINERALOGY. 233Ster.eochemica1 Reconstructions.S;lnce the appearance of the last Report, the following crystalshave been fully elucidated.Silver, Gold, coid Lead.---In the case of silver,1g the firsborderreflection-angles agree closely with d,, : d,,, : d,,, = 1 : 1 / d2 : 2 3 ,ratios which are characteristic of the f ace-centred, cubic lattice,and a calculation of the number of atoms in the unit-cell confirmsthe deduction.The same structure was deduced for gold andlead,20 the lead crystal having been obtained artificially byimmersing zinc in a solution of lead acetate. I n both cases, theinvestigation had to be restricted to the octahedral plane, owingto a platy habit. The structural deduction was based: (1) on thevalues of the glancing angles, and (2) on a normal distribution ofintensity over the first three orders.These investigations provethat silyer, gold, and lead have the structure previously deducedfor copper by W. I;. Bragg.,4 natase, TiO,.-This polymorphous modification of rutile hasbeen investigated by Vegard,21 who finds the structure to be ofBragg's diamond type, but) elongated along a fourfold axis to anextent implied by the ratio c :a= 1.765. Each titanium atom hastwo oxygen atoms (one above and one below) a t distances equal toabout one-fifth the vertical distance between successive titaniumatoms.A rnni onknz Iodide and Te frametl~ylainmoniztm, Iodide.--TheS-ray investigations of these two substances we also owe toVegard.22 I t is to be expected from its close crystallographicsimilarity that the firsLmentioned compound should have preciselythe same structure as rock-salt, and Vegard concludes that this isso, and that' the nitrogen and iodine atoms interpenetrate, one setcentring the cell faces of the other set,.* The position of thecase (in the hexagonal and rhombohedra1 systems it cannot theoretically gowrong) with respect to the number and method of interpenetration of theseprimary lattices.Stated in other words, the principle reveals the correctaxial ratios.l9 L. Vegard, Phil. Mag., 1916, [vi], 31, 8 3 ; A., 1916, ii, 186.2o Idem, ibid., 32, 65; -4., 1916, ii, 405.21 Idem, ibid., 32, 605; A., 1916, ii, 593.22 Idem, ibid., 1917, [vi], 33, 395; A., ii, 296.* Vegard does not appear to have calculated the theoretical intensitiesSome values worked out by the Reporter for demanded by his structure.the octahedral reflections are given here :-Order ........................ 1st 2nd 3rd 4thObserved .....................100 90 2 0 20Calculated .................. 100 46 7 4.5The, discrepancies can scarcely be regarded with equanimity.I"It mw234 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hydrogen atoms could not be fixed, owing to their relatively smallmass. It is interesting to note that amnionium iodide is therebyproved to have a differelit structure from aninioriiuin chloride, a.conclusion which had been deduced previously by other methods.The structural dissection of the tetragonal tetrainethyl derivativeis, of course, a much more complicated problem. The dimensionsof the elementary cell were f.ound to be in accordance with truicpthe accepted axial ratio c : a = 0.71, but the natural expectationthat the lattice should also have this double value led to no satis-factory reconstruction. In view of this, Vegard made the pro-visional assumption that the lattice has, indeed, the simple ratioc : n = 0.71, and eventually arrived a t a reconstruction,$ which can-not be described for lack of space.I? I / t ile G‘roup.-This well-known isomorphous group of minerals,consisting of rutile, TiO, (TiTiO, ?), cassiterite, SnO, (SnSnO, ?),zircon, ZrSiO,, and xenotime, YPO,, has been subjected to a search-ing analysis by two independent workers, Vegard and Williams ;the former examined the whole group; the latter confined hisattention t o rutile and cassiterite.I n his first examination,Vegard 23 drew the conclusion that xenotime occupies a peculiarposition structurally, but as a result of a later series of ineasure-irieiits,24 with an improved form of spectrometer, he revises thisconclusion. An apparently suitable structure for the whole groupwas offered by Vegard, but i t appears from Willianis’25 work(which was just ready for publication a t the time Vegard’s paperappeared) t h a t Vegard’s reconstruction rests on the faulty basisthat the 7 O 4 4 ’ (100)-reflection of rutile is a first-order reflection.This reflection was, indeed, also obtained by Williams, b u t i t ispreceded by a more intense reflection a t ail angle of 3O52’. Whilstthe experimental data of the two workers agree quite well in otherrespects, it need scarcely be stated that the discovery of a ‘‘sub-first ’ ’ order renders Vegard’s reconstruction untenable.Follow-ing are the essentials of the structure suggested by Williams.however, be obser\-ed that Vegard had t o grind octahedral planes on hiscrystals. May the discrepancies be due to errors of grinding ?* It must be pointed out t h a t such a result is riot merely surprising butexceedingly disconcert,ing. Unfortunately, i t would seem t o presage acertain want of trustworthiness in any dissection of crystal-structurewhich is not carried successfully t o the utmost atomic limits. An extremeview t o take would be that an X-ray dissection of crystal-structure must becompleted before i t has any value whatsoever.It is to be hoped that furtherwork will serve to clear up this “ irregularity.”23 Idem, ibid., 1916, [vil, 32, 65, 505; L4., 1916, ii, 593.2 4 Idem, ibid., 1917, Lvi], 33, 421 : A., ii, 296.2 5 C. M. Williams, Proc. Roy. Soc., 1917, [A], 93, 418 ; A., ii, 4.50CRYSTALLOGRAPHY AND MINERALOGY. 235The fuiidamental tetragoilal cell (Fig. 1 ), haxriiig the ratio(* : There are two s i t t i p l f , waysof fulfilling this coiiditioii: one is to centre the cell, t’he other tocentre the basal plane. Neither of these two simple possibilities,however, is reconcilable with the experimental data. The struc-ture finally offered is that given by Fig. 2 for the metallic atoms.[It can be regarded as niade up of eight interpenetrating space-lattices, each having the proper translation-ratio c : i i = 0.644. I Aclue to the position of the, oxygen atoms was obtained froni theabiiorinal intensities of the second-order (001)-reflections, whichpoint t o an intercalation of oxygen atoms in these structuralplanes.The calculated and observed iiitensities agree very well.The original paper gives a picture of the complete structure, whichexhibits tetragoiial screw-axes and eujoys holohedral symmetry.G~n~rcir! ~O~IcJLI.~iOtis.----The work of W. H. and W7. L. Bragg 011calcite and sodium nitrate, as well as Vegard’:, work 011 zircon andFIG. 1. FIG. 2.== 0.644, contains two molecules.xenotime, brings to the forefront a questmion of the utmost cheniicalimportance, naniely , the chemical constitution of inorganic com-pounds.The work shows that the sft.reochrnLiorI f o r m u l ~ ofcalcium carbonate and sodium nitrate on the one hand, and ofzirconium silicate and yttrium phosphate on the other, are just assimilar as, say, potassium sulphate and rubidium sulphate. Nowthe chemical similarity of the last pair is sanctioned by “ constitu-tional ” or “ valency ” formulie, but this is not true of the first andsecond pairs. It need scarcely be pointed out, t h a t the constitu-tional formulae of inorganic chemistry have been largely promptedby ideas derived froni organic chemistry, and do not take sufiicientaccount of ionic dissociation. A certain revision of inorganicformulze is involved in the idea of co-ordination, and it appearslikely that future developments of the theory of co-ordination willeventually restore consistency to ” valency formul~,” (Are thecrystal formulae ” stereochemical or are they ‘‘ stereophysical ” 1 )1” 236 ANNUAT, REPORTS ON THE PROGRESS OF CHEMTSTRY.Top’c-axes.The fuiidameiital c:orr.ectiiess of’ the conception of topic-axes wasiiivolvecl in Rragg’s demoiist,rat,ion that the reflection angles of tJheisomorphous potassium chloride and broinide have the siniplerelationship demanded by their respective molecular volumes.Apaper by Tutton26 is, however, none the less worthy of attention,since it deals with the more general cause of the orthorhonibicsystem. It is shown t h a t Ogg and Hopwood’s 27 preliminary resultsprove conclusively t h a t the absolute spacial distance of the mole-cular centres, in crystals of potassium, rubidium, msium, antiammonium sulphate, are indeed progressively increased t o the ex-tent precisely demanded by the molecular volumes, and t h a t topic-axes are therefore a trustworthy measure of relative moleculardistances in an isomorphous series.On the other hand, it ispointed out by Vegard28 that topic-axes are liable to yield a con-siderable amount of misinformation in ‘‘ morphotropic ” as opposedt o isomorphous comparisons. For example, the morphotropic regu-larities, supposed t o exist by Groth, between ammonium iodide andtetramethylammonium iodide, have no real existence. This con-clusion bears out a warning previously given by Barlow and Pope cQt h a t little, i f any, value attaches t o an indiscriminate calculationof topic-axes.A. Ledoux3O has published a paper on the question whether thetopic-axes of isomorphous mixtures are a purely additive functionof the composition-whether they are representable by straightgraphs.The rhombic and monoclinic pyroxenes are selected asmaterial, and the already existing data are supplemented by anextensive series of new measurements and density-determinations.I n order t o make the most rigid comparisons, i t is necessary to“ evaluate” the monoclinic angle fl to 90°, and the author gives amathematical solution of the problem. The general conclusion isthat topic-axes are an additive function, except, of conrse, in casesof double-salt-formation.Th e I‘alency Voltt r)i e Th ewy.A paper 013 the law of valency volumes has been published byBarlow,31 who appears to take the view t h a t the truth of the law26 A.E. H. Tutton, PTOC. Roy. SOC., 1917, [A], 93, 72 ; A . , ii, 244.27 A. Ogg and F. L. Hopwood, Phil. Mag., 1916, [vi], 32, 618; A., 1916,29 W. Barlow and W. J. Pope, ibid., 1915, [vi], 29, 745 ; A . 1915, ii, 427 ;30 ,4. Ledoiix, Bull. Xoc. frang. Min., 1916, 39, 232; A . , i , 49G.ii, 594.compare also Ann. Report, 1915, 255.2s L. Vegard, ibid., 1917, [vi], 33, 419.11’. B:arIow, Min. Mag.. 1910, 17, 314 ; A . , 1916, ii, 328237 CH Y STALLOGKA YH Y AND MI N ER ALOG Y.has beell established by previous work, aiid t h a t the law can accorcl-ingly be used as an iristrumeiit to probe the crystallographicrelatioiiships of allied substances.For example, in a series of con?-parisons between pairs of sulphates, it is shown that two out ofthe three spacial dimensions (given in the form of modified equi-valence parameters) preserve a relatively constant ratio, whilst thethird dimension varies as the total valency volume. This is heldto lend support to an idea that strata of sulphate radicles and ofnietallic atoms pervade the crystal structure.Oggand Hopwood 27 have subjected the isomorphous potsssium,rubidium, msium, and ammonium sulphates to a most thoroughX-ray examination, aiid have obtained results which prove that thefour salts are isotactic. The full working out of the intimatedetails has unavoidably been postponed, but the authors tentativelyconsider the struct,ure is based on a face-centred lattice having theordinarily accepted axial ratios n : 7) : c = 05737 : 1 : 0.7418 (potassiurtisalt). A brief examinatioii is msde of the bearings of their workon the valency volume theory.Z R a y data prove, for exarnple,t h a t the replacement of an atom of potassium by an atom of msiumproduces twice the distension brought about by the introdnctionof an ammonium group consisting of five ztorns. This result isheld to furnish conclu~ive evidence against the general truth ofthe theory. The difficulty of replacing one valency volume bywveii, without extensive structural clerangenieiits. is developed byTut tou,2G who points out, in a general discussion, that equivalenceparameters obscure the crystallographic relationship betweellpotassium, rubidium, anti caesium salts 011 the one halid and themmioniurii salts on the other.The theory has been commented on in two other papcm., ~ o ? n ( : irn po?.f(i it t ~ ~ ~ s t n ~ ~ o ~ ~ t .c r ~ ~ h i ( . h? csc frrch Y S .R,Ni( SeO,),,GH,O,i i i which R = K , Rb, C’s, aiid NH,, have been subjected to athorough niorphological, volume, and optical investigation byTuttoii.:;2 The results confirm all previous conclusions obtained i i iformer sttidies of this well-known group of double sulphates andselenates. I t is also pointed out that the crystallographic regu-larities of potassium, rubidium, and cmiurn salts may be referredto a regular sequence of atomic numbers iii lieu of atomic weights.The great value of a crystallographic investigatioa in doubtfulcases of isomerism is demonstrated by a recent paper by Bennett.3332 A.E. H. Tutton, Phil. Trans., 1917, [AJ, 217, 199; A., ii, 415.3 3 G. M. Bennett, T., 1917, 115, 490; A., i, 449.‘The i~io~oclinic double seleiiates of the general foruiul238 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It is shown that the a- and P-forms of sodium ferrocyanide arereally crystallographically identical. This, of course, rules out anypossibility of isomerism. The same is true for the reputedisomerism of potassium ferrocyanide.A more frequent use of the polarising microscope in chemicalinvestigations is advocated by Wright,”l who has done much t oimprove inicroscopic methods.3~ The maximuin and minimum re-fractive indices of a crystal can be rapidly determined to thesecond (perhaps the third) decimal place.The identification ofsugar-osazones and alkaloids is illustrated by numerous examples.The author, however, does not seem to be aware of the existenceof immense tables (built up on similar lines) by Kley SF a i dBolland si-the Reporter came across them accidentally.Karand6ev38 has added still another example to the list ofbiaxial crystals of proved rot’atory power. The new example isquercitol, C6H,(OH),, originally measured by Lewis. The authoraccepts Lewis’ axial ratios and amplifies the description by thedetermination of the correct setting and complex-symbol. Theoptic axes lie in the plane of symmetry, and consequently mayhave different rotatory powers. This theoretical possibility is ex-perimentally realised ; for 1 cm.thickness the respective rotationsfor, say, sodium light are - 3 5 O and -46’. It is also interestingto note that a solution is dextrorotatory. The whole investigationis an excellent example of the efficiency of the most recent gonio-metrical and optical methods.An interesting case of racemisrn and pseudo-racemism has beeninvestigated by Miss Kaplanova.39 The active modifications of thehydrochloride, hydrobromide, and hydriodide of glutamic acid areisomorphous with the dl-forms of the hydrochloride and hydro-bromide, but the d’l-form of the hydriodide cryst,allises in anothersystem, and is therefore a true racemate.V.Rmicky40 has courageously attempted to unite crystsl densi-ties and refractive indices in a novel way with a view to comparethe values of the new constants in isomorphous series.A new case of tetramorphism is announcecl,41 namely, that of2 : G-dinitro-p-toluidine.3 4 F. E. Wright, J . Amer. Chent. SOC., 1916, 38, 1647 ; i t . , 191G, ii, 571.s 5 F. E. Wright, J . Washington Acad. Sci., 1916, 6 , 466.36 P. D. C . Kley, Rec. trav. chim., 1903, 22, 367 ; A . , 1904, ii, 99.37 A. Bolland, Sitzungsber. K . Aknd. Wiss. Wien [Abt. 11. h. (Chemie),1908, 107, 671 ; 1910,119, 275, 1191.38 V. V. Karandeev, Bull. Acad. Sci. Petrograd, 2915, 9, 1285.y9 L. Kaplanova, Abh. B6hm. Akad., 1915, No. 23 ; A . , i , 547.40 V. Rosicky’, Rozpravy c’eske Akad.Prag, 1911, 20, No. 5 ; A , , ii, 433.41 E. Artini, Atti R. &4ccad. Lincei, 1917, [v], 26, i, 392 ; A., i, 389CRYSTALLOGRAPHY AND MINERALOGY. 239Eutectic structures in binary mixtures of organic coinpounds(varying proportions of camphor and benzoic acid, p-uitroaniline,p-dibromobenzene, phthalic anhydride, naphthalene, acetamide,salicylic acid, methyl thiocyanate) have been studied by Efreinov .42There are numerous excellent plates.An interesting example of eutectic structure is that known t omineralogists as “ graphic granite.” Thiq complicated phenomenonis being investigated by Fersinan,43 who has succeeded in deducinga law which governs the relative orientation of felspar and quartz ;the prismatic zone of felspar is parallel to the rhombDhedra1 edgeof quartz.It is shown t h a t all previous observations fit in withthis law. The author is preparing a monograph on this interestingsubject.The linear force of growing crystals is discussed in a paper byBecker and Day.45 It is shown that a growing crystal has thepower of raising a superimposed weight: provided no other crystals(free from weights) are present in the solution. This interestingobservation receives a satisfactory theoretical explanation ; theeffect of a load is to increase the solubility of the individual crystal.Graphic granite is probably not a e~tectic.4~A considerable body of literature on anisotropic liquids is to benoted. I n the first place, a long series of papers has been pub-lished by 0.Lehmann,46 who is evidently nursing quite a collec-tion of grievances and is distressed to find that some of his viewshave been annexed by others without a suitable acknowledgmeiit.It is a pity that the Karlsruhe physicist cannot bring himself towrite out a calm statement having a low coefficielit of irritation,for some of us wish to read him. It would also be a help if newobservations were rigorously segregated, On the other hand. ajudicious estimate of our present knowledge of liquid cryst,als ”has been given by Voigt,47 and the value of his contributions areenhanced by a mathematical treatment; but it is to Frenchobservers that, we owe the most interesting developments. Thenotable experiments of C. Mauguin (who a t present ( ( i s gloriouslycarrying out his duties in the trenches which defend the approaches42 N.N. Efremov, Bull. Acad. Sci. Petrograd, 1915, 9, 1309.43 A. E. Fersman, ibid., 1211.44 J. de Lapparent, Bull. SOC. frang. Miu., 1917, 40, 111.45 G. F. Becker and A. L. Day, J . Geol., 1916, 24, 313.46 0. Lehmann, Ann. Physilc, 1915, [iv], 46, 832 ; 4$, 177, 725 ;47 W. Voigt, Physikal. Zeitsch., 1916, 17, 76, 128, 152, s05.1916,51, 353; 1917, 52, 445, 527, 541240 AKNUAL REPORTS ON THE PROGRESS OF CEEMISTRY.to Nancy”)48 were described in the 1914 Report. As early as1913, Mauguin 49 made the observation that “ liquid crystals ” ofazoxyanisole take up a definite orientation on a cleavage surface ofmica (muscovite) ; a similar observation was independently madeby “ Captain-of-Artillery ” Grandjean,5O who extended the observa-tions, and has recently brought them to the publication stage.The experimental materia1 consisted of ten organic substaiices andthe following minerals : orpimeiit, blende, phlogopite, bmcite, talc.pyrophyllite, muscovite, rock-salt, sylvine, and leadhillite.Freshcleavages must be used. Regular orientations were obtained iiininety cases out of the possible hundred; in some cases the orienta-tion is independent of the temperature; in other cases it chaiigeseither discontinuously or continuously with the temperature. Thecontinuous variation proves that the property is not necessarilydue to an alignment of the molecular axes of the liquid on a rowof structural particles in the crystal-lattice, but is an equilibriurriproperty of a more general, capillary nature The author believesthat the observations point to (what the Reporter reads t o he)action a t a dist’ance.Mi7i eralogicnl Ch enaist ry ,A valuable paper on “ secondary enrichment ” deserveh thegeneral attention of mineralogists.I t is well known that thesurface oxidation of copper ores gives rise to copper and ironsulphates; the latter is rapidly hydrolysed to hydroxide, and theliberated sulphuric acid and copper sulphate percolate through theunoxidised ore and cause a secondary enrichment. The problemsof secondary enrichment are of great chemical interest and of con-siderable economic importance, and are being extensively studiedin America from all points of view.A recent paper by Zies,Allen, and Merwin51 throws much light on the chemical changesinvolved. The action of acidified solutions of copper sulphate 011redruthite, Cu,S, covellite, CuS, erubescite, Cu,FeS,,52 chalco-pyrite, CuFeS,, pyrrhotite, FeS +- ) I S , pyrites, FeS,. blende, ZnS,and galena, PbS--was investigated a t temperatures up to ZOO0 witha proper equipment o€ a u t ~ c l a v e s . ~ ~ In most cases, the real (as48 Presidential Address, Bull. SOC. franc. Min., 1915, 38, 5.49 C. Meuguin, Compt. rend., 1913, 156, 1246.50 F. Grandjean, Bull. SOC. franp. Min., 1916,39, 164 ; A . , ii, 451 ; i b d . ,61 E. G. Zies, E. T. Allen, and H. E. Merwin, Economic Geology, 1916,62 E. T. Men, Amer. J. Sci., 1916, [iv], 41, 409 ; A . , 1916, ii, 301.53 G.W. Marey, J . Washington Aoad. Sci,, 1927,7, 205 ; A., ii, 305.1917,40, 69.11, 4 0 7 ; A,, ii, 91CRYSTALLOQRAPHY AND MINERALOGY. 241opposed to “ descriptive ”) chemical equations have beeii determine(1.Thus the alteration of pyrites to reclruthite is strictly according t othe equation5FeS, + 14CuS0, + 1 3FI20 = 7c1ils + 3FeS0, + 12H,SO,.The geiieral effect of copper sulphate solution is expressed ahfollows : chalcopyrite -+ covellite + redruthite, which is vei-ystable a t the ordinary temperature, ant1 even a t 200° is oiily traiis-formed very slowly into copper and sulphuric acid. Secon(1a.i.yreactions begin to play an iniportaut r6le a t high teniperatures ;thus cupric and ferrous sulphates are partly transformed iiit ocuprous and ferric sulphates, and subsequent hydrolysis may givehrematite, FeLO:$, cuprite, Cu,O, and nietallic copper.Cuprouysulphate is more reactive than cupric sulphate. The general effectof free sulphuric acid is to retard the formation of cuproilssulphate.The iriuch vexed questioii of the various f o r m of c.alciuiiicarbonate has, perhaps, received a final solution a t the hands ofJohnston, Merwin, and W i l l i a r n s ~ n . ~ ~ These authors conclude froina critical survey of previous investigations, supplemented wheunecessary by new observations, t h a t the only real forms are calcite,aragonite, and a new form, p-calcite, which is not very stable inpresence of water, Further, there is a definite hexahydrate.Four reputed forms are considered t o be superfluous: vaterite is aporous calcite, coiichite and ktypeite are porous aragonites, whilstlublinite has beeii definitely proved by Quercigh55 to be ;I’‘ variety ” of calcite.Under ordinary pressure, calcite is the stableform a t all temperatures. Aragonite changes pseudoniorphouslyinto calcite a t rates which increase with the temperature, thechange being almost instantaiieous a t 470O; it also changes moreor less rapidly in presence of water-at looo, two weeks are neces-sary. There is, however, indirect evidence for a reversible tram-formation at. - looo (private corninuiiicatioii of R. (’. Wells). Thepreparation of p-calcite is iiot a suitable lecture experinlent. I t i +best obtained a t 606, and is always contaniiuated with calcite ant1aragonite ; D = 2.54 or higher ; p, = 1-55, ,u2: 1.65.Syhtenl.hexagonal. The hexahydrate is irioiioclinic ; 2E = 7 2 O 3 O ; a -1.460, p = 1.535, y = 1.545.carbonate has been discussed by Johnston and Williamson .56The r61e of inorganic agencies in the deposition of calciuin15* J. Johnston, H. E. Merwin, and E. D. Williamson, ,411~er. J . S c i . , 1916,5 5 E. Quercigh, Rivista Min. Crbt. Ital., 1916, 44, 65.s6 J. Johnston and E. D. Williamson. J , Geol., 1916, 24, 729: A . , ii. 313,[iv], 41, 473 ; A . , 1916, i i , 433242 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.W. F. Hallimond57 has published a study of the crystallographyand dehydration of the complex copper uranyl phosphate,torbernite, Cu(U0,),(P0,),,8H20. The most probable axial ratiois c : LI = 2.974 ; there is no weighty crystallographic evidence againstthe system being tetragonal.The pt-dehydration curve oftorbernite -+- meta-torbernite I (the change is irreversible) wasmapped out in an ingenious manner. The author has observedt h a t loss of water is confined to the edges or pyramidal faces of thecrystals, and he makes the interesting suggestion that loss of waterthrough the basal plane is prevented by the high reticular densityin this plane, demanded alike by perfect cleavage and the highvalue c : ( I .Mention must be rnacie of a “paper” of 1200 pages by Wash-ington,58 in which all igneous-rock analyses published in the period1884-1913 are critically discussed.Tker??zul ,!!tudirs of i%fiii e m 1 Lsystenzs.As melltiolled in the introduction, the thermal studies of mineralsystems, undertaken especially by American workers, are alreadyleading t o important practical conclusions.It must be noted thatattention is no longer confined to anhydrous systems. A mostcomprehensive investigation of the system ?rlnter-i,otns.~iut~l m e tn-silicnte-siEica has been undertaken by Morey.59 The Reporter muststate quite frankly that he has not yet succeeded in reducing theresults of this investigation to a moderate compass; so, for thepresent, he asks leave to proceed to some anhydrous systems.Bii?c(r!j S y s t ~ ? ? z , Soncc-1i4yheli?i,e-l.’otnsli-?iep?~eli?ze, (Na,K)AlSiO,.-For the essential details of this system, consult the abstract.60SysteitL, LTroti-OL?.yy/ei/ .-The portion of this system which relatest o the important minerals hzematite, Fe,O,, and magnetite, Fe304,has been subjected t o a remarkable experimental study by Sosmanand HostetterjG1 who have determined the pressures of oxygen (dueto dissociation) in a specially constructed vacuum-furnace.Aseries of measurements was carried out a t l l O O o and 1200O. Thedissociation pressures are quite small; thus a t l l O O o the pressureis 0.37 mm. over hzmatite and <0.005 over magnetite.The change 3Fe,O, 0 + 2Fe30, is proved to be reversible, for57 W. F. Hallimond, Min. Mag., 1916, 17, 326; A., 1916, ii, 258.58 H. S. Washington, U.S. Geol. Survey, 1916, Professional Paper 99.59 G. W. Morey and C. N. Fenner, J.Arner. Chern. SOC., 1917, 39, 1173;6o N. L. Bowen, Amer. J. X c i . , 1917, [iv], 43, 115; A . , ii, 178.61 R. B. Sosman and J. C. Hostetter, J. Amer. Ghem. SOC., 1916, 38, 807;A , , ii, 370.A., 1916, ii, 331CRYSTALLOGRAPHY AND MINERALOGY. 293idelltical oxygen pressures are obtained indifferently by oxidationof magnetite or by dissociation of pure ferric oxide. The twooxides form a continuous series of solid solutions. Further workby the same authors62 shows that ferric oxide exhibits a small butmeasurable dissociation when heated in air a t 1100-1300°, andthat the amount of dissociatioii increases with the temperature.Again, the equilibrium relationships of hzematite and magnetitehave been probed63 by a determination of the magnetic suscepti-bility of a carefully analysed series of natural and artificial pro-ducts.This susceptibility is proved t o be approximately proportioxla1 to the ferrous oxide conteiit. Finally,64 the interestingobservation was made that certain crystals of hzematite from Elbaexhibit a zonal structure, in which magnetic susceptibility goeshand in hand with the amount of ferrous oxide in the variouszones; the authors’ researches indicate that such variations can bereadily interpreted as due to fluctuations of temperature andpressure during crystal growth.Te7.n or? System , CaO-Al,O,-MgO . 65-Consul t abstract.TPrtiory S y s t e m , Dioyride-Albite-rl northif e.66-Boweii’s experi-mental study of the equilibrium relationships of these three coin-ponents derives great importance from its high petrological signifi-cance; although it is true that pure substances were advisedlyemployed (whereby the system becomes less complicated than theaverage natural rock system), yet the results obtained can safelybe held t o present the main fe.atures of the natural history ofbasalts and diorites, and, with proper prudence, may even beapplied to the elucidation of more remote problems.Of the threebinary systems concerned, the plagioclase series of solid solutions(albite-anorthite) has been described in a previous Report.67 Diop-side and anorthite present an ordinary eutectic a t 1270O (42 percent. anorthite) ; finally, the position of the eutectic diopside-albite(about 97 per cent. albite) could only be obtained by extrapola-tion, owing to the sluggishness of crystallisation of albite fusions.The ternary system was explored by the quenching method,6* and,as is only to be expected froni the existence of continuous solidsolutions of plagioclase, does not present any absolute ternary62 J.C. Hostetter and R. B. Sosniati, J . Amer. Ghetn. Soc., 1916, 38, 118 ;&4., 1916, ii, 440.6 3 R. B. Sosman and J. C . Hostetter, B d l . Amer. Inst. Min. Engineers,1917, 907.6 4 Idem, ibid., 933.6 5 G. A. Rankin and H. E. Nerwin, J . 9mer. CIhent. SOC., 1916, 38, 568 ;66 N. L. Bowen, Amer. J . Sci., 1915, [iv], MI 161 ; A . , 1915, ii, 694.67 Ann. Report, 1913, 254..4., 1916, ii, 249.68 Ibid., 1914, 15244 ANNUAL REPORTS ON THE PROGRESS OF CHEMLSTRY.eutectic.This disposes of a whole mythology of iieolithicantiquity. The results are conveniently embodied in the usualequilateral diagram (Fig. 3), reference t o which will facilitate adiscussion of the course of crystallisation of two typical mixtures.The composition of the first mixture (50 per cent. diopside, 25 percent. albite, 25 per cent. anorthite) is represented by the point F.The dotted isotherms indicate t h a t cryst,allisation begins a t 1275O,and, as pure diopside separates, the conipositioii of the residualfusion moves along the h i e FG until the bouiidary curve tliop-side-plagioclase is reached. Further cooling is now signalised bytrhe appearaiice of plagioclase (and, of course, more diopside), thecomposition of the plagioclase, as deterniiiied experimentally, beingAb,An4 (the point H of the diagram).Any subsequent coolingleads to a simultaneous separation of diopside and a series of plagio-clases-richer and richer in albite ; contemporaneously, previousgenerations of plagioclase crystals, if sufficiently minute, will dis-solve progressively, but, on the other hand, they may be protectedby a zonal coating of material having an equilibrium-composition,and in that way survive. Under ordinary conditions (that is245 CRYSTALLOGRA PHI' AND MINERALOGY.\+7]1el) protected by zoning), the final cornposition of the last traceof liquid lies a t some point, on the boundary curve beyond Jf, hutLllider ideal conditions t,he l i t h i solidifica tioil w0ulcl he a t M .The secolld type of rnixture is t h a l i l l which plagioclase is thelirst to crystallise.A mixture, I? (10 per cent. diopside, 90 percent. AbI8Ang2), begins to crystallise a t 1480°, with the separatiollof Ab,An9,,, and the composition of the liquid follows the curve/ClY. The path of such curve is no light matter to determine, butan ingenious combination of isotherms and '' isofracts " (curves ofequal refractive index; note : refractive index determines thechemical composition of a mixture) was found to suffice, At thepoint X (1245O) diopside begins to appear, and the subsequentcourse of crystallisation is similar in principle to that describedabove.Relying 011 the above investigation and on similar researches ofprecision, already noted in these Reports, Bou7en89 proceeds to amasterly discussion of the problem of the origin of igneous rocksin general.H e shows that there is no necessity to postulate eitherthe existence of a number of magmas or the differentiation of anorigiiial magma into two or more immiscible fluids prior to crystal-lisation. On the contrary: an originally basic magma will, oncooling, give rise to a series of minerals ranging from ultra-basicto ultra-acidic ; moreover, a sinking of relatively heavy crystalssupplies just t h a t sorting-out process which is needed for the forma-tion of rocks of such different types as peridotites, basalts, diorites,granites, and syenites. Bowen's arguments are punctuated by awealth of field evidence, chiefly collected by Anierican geologists.I n a later paper,TO he examines the question as t o the origin ofmono-mineralic rocks, especially the anorthosites, which have beenobserved in immense masses in the Adirondaclrs and in the MorinDistrict of Canada.Two truths are pretty obvious from thediagram (Fig. 3) : (1) a copious crystallisation of plagioclase can0111~ Occur after a large proportion of pyroxene ha5 separated, and,presumably, sunk by virtue of its high density; (2) when plagio-clase crystals have separated in quantity, there is but little residualliquid, and i t would seem t h a t the magma should now be too viscousto p n e t r a t e surrounding rocks in the form of dykes. Fieldevidence does, i n fact, demonstrate the absence of intrusive out-liers from the main mass, and also that the adjoining syenites aredue t o a later stage of crystallisation.issmd as a supplement, and bound with.J . Gee?., 1915, 23.6* N. 1;. Bowen, " The later stages of the evolution of igneons rocks "-'O N. Ti Rowen, ibid., 1917.25, 209246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.S t u h i f i t y of t l i r I’/(itio ,5’/ii / t i r p o t i ( I ~ i ~ o w i t l g (‘taystuf.General observation of crystal forms warrants the conclusionthat a plane-faced polyhedron represents the natural boundary ofa gr-owing crystal. The conclusioii derives support from numerousexpriments. It was early observed that when an artificially frac-tured crystal is placed in a supersaturated solution, i t grows morequickly a t the fractured part, and the common statement is thatit gradually takes up its original form.Most’ diverse observationson this point are recorded by Rauber,’I who was so struck withthe inherent powers of a **mutilated” crystal t o heal itself thathe was led t o propound the theo’ry that crystals are controlled byvital forces. Rauber’s studies were purely qualitative. Laterinvestigations in this interesting province we owe to Artem6ev,72who by the help of the two-circle goniometer checked the “heal-ing ’’ process with exact measurements. The method adopted wasto grind a crystal hemisphere of 5 or 10 mm. diameter and cementit to a corresponding glass hemisphere. The comDosite sphere wasthen suspended in a slightly supersaturated solution, taken outfrom time t o time, and examined on the goniometer.The systemsstudied were cubic, monoclinic, and anorthic. The generalbehaviour is as follows. I n the first period of growth, the sphereexhibits a number of glittering spots (on the goniometer) corre-sponding with the most important faces. The rest of the surfaceremains matt, but’ later becomes covered with tiny crystals inparallel position, each of which contributes a part t o sharp gonio-meter reflections of the important forms ; simultaneously, reflectionscorresponding with less important forms appear as glimmeringpoints. As growth proceeds, the less important faces disappear,the tiny, parallel crystals coalesce, and the final result is a hemi-crystal wholly bounded by common faces.Artem6ev’s method islikely t o receive considerable attention on account of the valuablelight it throws on other problems. Thus, inasmuch as the transi-tory faces often include general forms { h k l j , the class of symmetrymay be elucidated; for example, in the case of alum, the form{ 210) is hemihedrally developed as the pentagonal dodecahedron.Again, the method might be employed with advantage wheneverthe natural crystal fails to develop those facets which are necessaryfor a full calculation of the axial ratios.51 A. Rauber, “ Die Regeneration der Krystalle,” 1895-1896.7 * D. N. ArtemBev, ZeitscJt. Kryst. &fin., 1910, 48, 417 ; A . , 1911, ii, 24CRYSTALLOGRAPHY A N D MINERALOGY 247I’h I‘ C U I - I - ~ J , ! ,SIII f t r r c Y o/ ( 1 D i x x o l i ~ ~ i t g Crgsttrl.Experimental attention to this question appears historically tohave passed through three well-defined phases, nalnely : (1) etchingstudies of crystal-faces ; (2) observations of the successive f o r massumed by a sphere when subjected to an all-round action of adissolvant ; and (3) investigations of the alteration of form broughtabout by a reversal of the growth process owing to the action ofslightly unsaturated solutions.Observations belonging to the firstand second class are largely coupled with the use of “chemicaldissolvants.” I n recent years, we owe much to the work ofV. Goldschmidt 73 and his co-workers. Thus, extensive investiga-tions have been made on the etching of both natural crystals andspheres of calcite by means of phosphoric, hydrochloric, nitric,formic, and acetic acids.The sphere is first etched in tracts corre-sponding with those natural faces which are especially prone toattack, namely, c { l l l } , T { loo}, and t(T11). A total disappear-ance of the etch-figures marks the next stage; the entire surfacebecomes affected, the poles of the above-mentioned faces becomingmost sharply pronounced Cornem of curved faces. This emphasisesthe inverted relationship of growth and dissolution. As solutibngoes on, these inversion-corners shift slightly (but their movementsare in accordance with crystal-symmetry) until a t last a “finalform ” is reached which dissolves without change of shape. Thefinal form appears to depend, first, on the original form of a naturalcrystal (not, of course, if a sphere has been ground), and, secondly,on the acid used and its concentration.I n any case, it is whollybounded by curved faces. Similar results were obtained with zincblende.74 The above investigations have thrown much light. on themanifold corrosion forms exhibited by natural crystals of thediamond .75Results in substantial agreement with the above have beenobtained by Schnorr76 in his study of the dissolvanb action ofslightly unsaturated solutions of sodium chloride (containing carb-amide) on crystals of rock-salt. The first action is t o bevel thecube edges with the form { h k 0 ) ; the value k/X: changes pro-gressively. The cube-corners are then modified by faces of theicositetrahedron { hkk 1, which reduce and finally extinguish the(ItkO} forms; the value h / k depends on the degree of unsaturationV. Goldschmidt and F.E. Wright, Jahrb. Min. Beit.-Bd., 1903, 17, 355 ;The first paper contains a copious bibliography of earlier work,7 4 P. Hochschild, ibid., 1908, 26, 178.18, 335.including ordinary etch-figuros.7 5 A. E. Fersman and V. Goldschmidt, “ Der Diamant,” 191 1.70 W. Schnorr, Zeitsch. Kryst. Alin., 1915, 54, 289 ; A , , ii, 469248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the solution, but in any case [IhkX:} represents the final forin.The behaviour of a sphere is very instructive. Etch-hollows firstappear on the octahedron-poles ; then corners of the icositetrahedroilappear a t the cube-poles, the final form being the icositetrahedron.Numerous experiments with solutions containing different amountsof carbamide proved t h a t the final form obeys Goldschmidt, andll’right’s law of polarity ” ; the corners of a dissolving crystal(.orrespond with the face-poles of a growing crystal.Curie’s C a p * l l a d y Theory.Acording to Curie’s theory,77 the most stable form which can beassumed by a crystal as a r e s u l t of capillary forces is t h a t forwhich t h e total surface energy is a minimum. Each crystal facehas its specific capillarity constant, measured by the work involvedin increasing the extent of the face by the unit of area.If wedenote the areas of the various faces by S,, S,, S,, . . ., and thecapillarity constants by A , , A,, A,, .. ., then the stable form ofthe crystal will be t h a t for which 2(A,S,+A&,+A,S, . . .) is aminimum for a given volume. It will be clear that a knowledgeof, these capillarity constants would enable us to predict the formof a crystal; for example, in the case of a cubic crystal like commonsalt, in which the cube and octahedron faces are frequentlyobserved, the crystal could alternatively only develop cube or octa-hedron faces accordingly as Aloe: All, < l / d3 or > J%. Anattempt was made to determine the constants for common salt bymeasuring the angle t h a t the edge of a drop makes with the faceon which i t lies,78 such angle being supposed to be related to thecapillarity constant by a formula given by Gauss.Although thevalues fluctuated considerably for different specimens, they appearedto demonstrate the existence of capillarity differences ; moreover,the relative values cube : octahedron were reversed by addition ofa sufficient amount of carbamide, the presence of which is wellknown to favour an octahedral development. These results, how-ever, were unfavourably criticised by pock el^.'^Curie’s theory acquired considerable notice from its inclusion inOstwald’s “ Lehrbuch.” The theory demands t h a t large crystalsmust grow a t the expense of small ones in favourable circumstances,as, for example, when the temperature is fluctuating slightly. Thequestion whether small crystals are the more readily soluble wasinvestigated by Hulett,so who determined the sparing solubilities77 P.Curie, Bull. Xoc. frang. Min., 1885, 8, 145.7 8 S. Berent, Zeitsch. Kryst. Min., 1896, 26, 629.7y F. Pockels, Naturwiss. Rundschau, 1899, 14, 383.G. A. Hulett, Zeitwh. physikal. Chem., 1901, 37, 385 ; A . , 1901, ii, 493CRYSTALLOGRAPHY' AND MINEKALOQT. 249involved in the cases of gypsum and barium sulphate in terms ofelectric conductivity. For the former substance, he was able todemonstrate a temporary exhaltation ; particles having approxim-ately a radius of 0.0003 mm. gave a solubility of 18.2 millimols. perlitre, whilst particles with a radius of 0.002 mm. gave the normalsolubility of 15.33 millimols. Similar results were obtained withbarium sulphate. It is important t o note how small must be thecrystal particles in order to obtain differences of solubility, owingto surf ace tension.R eltr t i tic 1' r loc i f it.s of G r o t ?I .Crystallographically, Curie's theory first acquired something1110re than academic interest when Wulff s1 published ail importantresearch on the relative velocities of growth of crystal-faces, t h a tis, the relative rates a t which each face advances from the centreof the crystal.(monoclinic), and the following rates of growth were determined :(Oll)=2-77. Accepting Curie's theory, Wulff essayed to go a stepfurther by offering a proof t h a t these relative velocities of growth,which can be easily determined, are, in fact, proportional to thecapillarity constants. It was, however, pointed out by Hilton 82t h a t the method of proof was faulty; a rigorous proof was advanced.Another proof has been given recently.83 Now, Wulff adopted theview that the t r u t h of the theory was established by his work; butFriedelR4 has recently pointed out that Wulff obtained the sameresults with crystals of different habits, and this shows that a dis-torted crystal does not tend to approach an ideal form.Fastert'sssobservations on the growth of common salt point the same way.The substance selected was Mohr's salt,(NH,),Fe( SO,),,GH,O(201) = 1-00, (110) = 1-96, (001) =2-25, (111) = 2-50, (iii) d - 6 4 ,R el c( ti u e Y e I o c i t i es of I ! issol u t ion .Experimental determinations of rates of solution can, from thenature of the case, never be exact. The faces become pitted; theedges round off; the crystal altogether faiis to preserve the ciean-cut edges and plane faces characteristic of steady growth.Wulff81 G. Wulff, Zeitsch. Kryst. M i n . , 1901, 34, 386. The work appeared inRz H. Hilton, ( ' c n / r . M i ) ) , , 1901, 573. Also consult his " Mathematicnl.93 II. Liebinniin, Zeitscli. KT!JS/. .,IIi)i., 1914, 53, l i l .H 5 C . Fastert, Jahrb. Min., Bei1.-Rd., 1912, 33, 265.Russian in 1895.Cryst n l l c ~ g r ~ i ~ ~ h ~ ," 1903, 105.( i . li'rictlel, J . Chim p h ? ~ ~ . , 1918, 11, 478 ; A . , 1913, ii, 8-14250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.found that all faces of Mohr's salt dissolve a t the same rate.I<orbs,86 however, found different rates for a few substances (especi-ally potassium ferrocyanide) out of a much larger number iavesti-gated.Nave GrysIul Ficces Diffevetit Soliihilitie.v?The assumption that different faces have different solubilities isreally involved in Curie's theory, for without the assumption i t isimpossible to conceive how a distorted crystal can assume the trueequilibrium form (with minimum surface energy) when suspendedin a saturated solution unless certain faces dissolve whilst othersgrow.The earlier attempts to settle the question were indirectand have led to nothing but controversies. Le Blancd7 was thefirst t o point out t!hat the oiily satisfactory way of decidiiig thequestion is to see whether it is possible to realise such a concen-tration of solution t h a t one face of a crystal grows whilst anotherdissolves. Experiments on the " prism " (which prism 12) andcleavage pinacoid of potassium dichromate were cautiously held tobe inconclusive. A notable research by Valetons8 appears to hedecisive. A solution was made to circulate through two vessels(held in separate thermostats), one containing the crystal underexamination, the other containing a supply of solid solute. Therelative temperatures of the two vessels could then be varied everso slightly, so as to cause growth or dissolution a t will. Growthor dissolution was detected by examining the crystal on the gonio-meter ; a growing crystal gives sharp reflections, a dissolving crystala band of reflections. The thermostats could be held constant t oO.O0lo. An increment in the temperature difference of thee twovessels amounting to 0'003O was sufficient to transform uiimistak-able growth iiito unmistakable dissolution. A long series of ex-periments proved that. i t was not possible to obtain conditions a twhich cube or dodecahedron faces of alum dissolve whilst octa-hedron faces grow. The crystals investigated varied between 2and 20 mm. in diameter.86 A. Korhs, Zeitsch. Kryst. iMin., 1907, 43, 433.87 M. Le Blanc and G. Eiissafov, Eer. K. Sachs. Ges. l V i s s . , [Math.-Ph~/s.31. Tie Bhnc and I. I. Andr&ev, Zeitsch. physik.rl. Chein., 1911, 77,8 8 J. J . P. V:i.lctoii. EPr. J<. A'iiah.s. QPS. W~SR., L]Mnth.-Ph?/s. K l n s s ~ ] , 191 5,Klccsse], 1913, 65, 199; A . , 1914, ii, 268.635.67, I 25 1In his work, “ On the equilibrium of heterogeneous sulmtaiices,”and some years before Curie published his theory, Gibbs $9 deducedthat $(L4,S,+ ,4,S,+ . . .) has a minimum value for constantvolume; but he went further, and made the deduction that thetcirtlciic:,l of CL crystcrl t o tcilce up tI((1 equilibi-iu?rt f o r m i s ?‘?t vrrselypi-oporf iouui t o i t s l i i 7 ~ ~ 1 ’ d i m ensiotto. In a n interesting discussioii011 crystal growth, he adds: “ On the whole, i t Feeins iiot improbal~lethat the form of very minute crystals in equilibrium with solveiitsis principally determiiied by the conditioii t h a t 2(.41bY, + . . .)shall be a minimum for the volume of the crystal, but as they grow(in a solvent no more supersaturated than is necessary to makethem grow a t all), the deposition of new matter on the differentsurfaces will be determiiied more by the nat,nre (orientat ion) of thesurfaces and less by their size and relations t o the surrouiidiiigsurfaces. ”The coiiiiexion between capillarity coiistants and solubilities hasbeen discussed by Berthoud .go Theri.nodynamic conditions ofThe latter.crystals, ifequilibrium are studied by Valeton and by Friedel.coucludes t h a t “ Curie’s theory is applicable to liquidwch crystals exist.”T. V.8“ J. IV. Gibljs, “ Scieiitific Phpws,” 1906, 1. :!20-326.!Io A. Berthoud, J . C ~ ~ U E . . p7/5ps., 1912, 10, 624 ; A . , 1913,BARKER.i, 305

ISSN:0365-6217    

DOI:10.1039/AR9171400226

出版商:RSC    

年代:1917

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INDEX OF AUTHORS’ NAMES.Abderhalden, E., 82, 90, 81, 235.Achterfeld, F., 66.Acree, S. F., 10, 15, 16, 76, 150.Aita, A., 151.Alber, A4., 53.Albert, A., G8.Allen, C. H., 71.Allen, E. T., 240.Allen, H. S., 4.Allison, F. E., 209.Alt, A. D., 155.Alway, F. J., 207.Ames, J. W., 210.Anderson, G. W., 153.Anderson, R. P., 148, 149.Angeli, A., 114.Anthes, E., 86.-4ppleyard, A., 20-1.Arnd, T., 1G5.Artini, E., 238.Atkins, W. R. G., 158.dubry, A., 80.Auffenberg, E., 75.Auwers, K. von, 75.Averitt,, S. D., 169.BZck, T., 146.Bagster, L. S., 68.Bailey, J . R., 131.Baker, A. F., 212.Baker, J. L., 223.Baker, W., 176.Balduzzi, O., 127.Barab, J., 37.Baragiola, W. I., 151.Rardach, F., 53.Barker, M. F., 156.Barker, T. V., 10, 227.Barlow, W., 236.Barnebey, 0.L., 163.Bassett, H., jun., 43, 199, 213.Bateman, W. G., 221.Batuecas, T., 167.Baudisch, O., 113.Bauer, H., 200.Bauermeister, M., 123.Baumann, C., 159.Bazzoni, C. B., 4, 5.Beckenkamp, J., 7, 230.Becker, G. F., 2RO.Becker, H., 75.Becker, J., 87.Behrman, ,4. S., 101).Eencker, F., 54.Bennett, G. hf., 337.Rergius, M., 139.Bergmann, M., 79, 218.Berman, 191.Berthelot,, A., 191.Bertram, S. H., 63.Biazzo, R., 157.Richowsky, F. R. von, 167.Rielov, C. A., 220.Bigelow, L. A, 107.Riilmann, E., 71, 139.Biltz, H., 139.Bishop, G. M., 163.Bjerrum, J., 139.Blanck, E., 210, 213.Bloch, B., 196.Bodforss, S., 106.Boeseken, J., 65.Boer, S. de, 178.Bottcher, B., 142.Bokorny, T., 225.Bolton, E.K., 144.Boncquet, M., 218.Boncquet, P. A., 218.Rorgmann, 223.Rorsche, W., 71, 95, 131.Bougault, J., 169.Bourquelot, E., 77, 80.BOU~OUCOS, G. J., 207.Bowen, N. L., 242, 243, 246.Brctgg, W. H., 227.Brandt, R., 150.Braun, J. von, 78, 130, 138, 142.Bray, W. C., 51.Breazeale, J. F., 198, 213.Brenchley, (Miss) W. E., 216.Brewer, G., 159.25254 1X;DE;YBriggs, L. J., 195.Briggs, S. H. C., 10, 33.Rrigharn, R. O., 217.Rrinton, P. H. 31. P., 44.Broderson, H. G . , 154.Hroeksmit, T. C. .I;., 1.53.ISrown, B. M., 16.Brown, 11. J., 40.Hrown, P. E., 200, 205, 210.Browning, P. E., 44, 1 6 1 .Rruckniiller, F. W., 164.Hruhns, G., 16'7.Hrunel, R. F., 73.Hrunnschweiler, P., 142.Uuchanan, G. H., 161.Ruisson, H., 30.Kuisson, J.P. dn, 200.Burclick, C. I,., 144.Hurgess, P. S., 2U5, 1 1 1.Burns, I)., 19.5.Busch, M., 66, 116.Husvold, N., 164.Hyl, A. J., 9.Crthen, E., 71.Carnot, A., 166.Carr, R. H., 202.Cassel, H. W., 72.Cavazzi, A., 166.Cermak, P., 229.Chatterjee, N. R., 92.Chauvenet, E., 49.Chick, (Miss) H., 182, 183, 184.Chowdhuri, T. C., 86.Christensen, A., 142.Christensen, H. R., 201, 21'7.Ciamician, G., 220.Claasz, M., 128.Clark, W. M., 201.Close, H. W., 16.Cole, S. W., 191, 192.Coleman, D. A., 20(iColson, E., 89, 209.Colvcr, C. W., 219.Colver, E. de W. S., 157.Conant, J. R., 107, l(i7.Conno, E. de', 153.Cook, F. C., 210.Cook, R. C., 209.Cooke, R. E., 5s.Cooper, L. F., 187. 22.3.Corson, G. E., 200.Coupin, H., 216.Cranfield, H.T., 212.Crann, T. W., 16.Crombie, J. N., 36.Crowther, C., 222, 224.Cullen, G. E., 173, 174, 176.Cunningham, (Miss) M., 302.Currie, J. N., 225.Curtis, E. W., 213.Curtius, T., St), 91.OF AUTHOIiS' NAMES.I Curtman, L. J., 161.Czaporowski, L., 99.Oakill, k1. L)., 89.Dale, J. K., 76.Damm, P., 139.Datta, R. L., 92.David, 149.Davis, C. W., 150.Davis, M., 185.Dawson, H. M., 10.Day, A. TA., 239.Debye, P., 5, 9, 226.Dechambre, P., 222.Degli, A., 221.Dehn, W. &I., 149.Delprat, M., 190.Demoussy, E., 214.Denham, W. S., 81.DenigBs, G., 153, 162.Descamps, L., 148.Devaux, H., 217.Dey, M. L., 52.Dieckmann, W., 74, 97, 98, 99.Dietz, W., 116.Disselkamp, P., 119.Ditz, H., 53.Dixon, A.E., 88.Doisy, E. A., 160.Dolch, P., 57.Donnelly, J. L., 57.Dorbe, C., 202.Doubt, (Miss) S. L., 221.Dover, (Miss) M. V., 167.Dowell, C. T., 51.Downs, C. R., 156.DOX, A. W., 155, 224.Drew, H. D. K., 17, 84.Dreyfus, H., 70.Druce, J. G. F., 41.Drummond, J. C., lS6.Dyer, D. C., 156.Eble, K., 09.Eckert, A., 93.Edgar, G., 53.Efremov, N. N., 239.Egloff, G., 62.Ehrlich, F., 218, 225.Eichel, A., 126, 142.Eichwald, E., 82.Ellis, J. H., 11.Elvert, H., 99.Elvove, E., 166.Embden, G., 194.Emmert, R., 126.Ericson, E. J., 164.Fa'ury, C., 30.Fagan, T. W., 186255Ftthrenwald, 146.Pajans, K., 2, 3.Fadtis, F., 137.Fedorov, E. S., 230.Fellenberg, T. von, 15'3, 218.Veimer, C. N., 242.Fernau, A., 23.Fersman, A.E., 239.Filippi, E., 141.Findlay, L., 195.Fischer, E., 79, 90, 105, 218.Fischer, F., 54.Fiscliler, J., 2.Fitz, R., 175, 176.Fock, A., 7, 229.Fodor, A., 90, 225.Foerster, F., 57.Folin, O., 160.Foote, H. W., 34.Pormaiiek, J., 148.Fox, J. J., 156.Franzen, H., 115.Freund, M., 138.Friedemann, U., 192.Fry, H. S., ST.Fry, W. H., 151, 198.Fiirat, B. von, 115.Funk, C., 182, 183.Gabriel, S., 85.Gadamer, J., 141.Gainey, P. L., 204.Gast, W., 218.Gaule, A., 87.Gemtchoughenikov, E. A., 21 6.Gericke, W. F., 170.Gettler, A. O., 17G.Gewecke, J., 167.Ghosh, J. C., 52.Ghosh, P. C., 67.Ghosh, S., 76.Gibson, C. S., 95.Gillespie, L. J., 150, 201.Godden, W., 222.Goetsch, E., 189.Gooch, F. A., 168.Goodson, (Miss) A., 35.Goris, A., 222.Gortner, R.A., 202, 203.Grandjean, F., 240.Greaves, J. J., 205.Grischkevitsch -Trod] imovski, E. , 12 1Groschuff, E., 31.Grossfeld, J., 159.Grossmann, H., 166.Gruber, J., 41.Griin, A., 64.Griittner, G., 73, 1 I S, 120.Gruse, W. A., 1G.Gruzit, 0. M., 201.Gsell, H., 148.Guglialmelli, L., 153.Guillin, R., 21 1.Gupha, N. A i . , 46.Gutbier, A., 59.Guye, P. A., 1.C1uzmaii Ctwr&nc'io, J. de, lti7.Haar, A. W. van der, 78, 154, 1.78.Haensler, P., 141.Hager, G., 209.Hahn, (Miss) D. A., 91.Haigh, F. L., 1GO.Hall, N. F., 2, 4, 30.Hall, R. E., 28.Halliburton, W. D., 180.Hallimond, W. F., 242.Hamburger, L., 24.Hansen, L. W., 63.Harden, A., 185, 224.Harkins, W. D., 3, 27, 2s.Harried, H.S., 167.Harries, C., 55, 66.Harris, B. R., 161.Harris, F. S., 207.Harris, J. E., 19s.Hart. E. B., 280, 223.Hart, R., 158.Hartley, E. G. J., 86.Hasselbitlch, K. A., 172, ZiS.Hawes, W. C., 1G3.Hawley, F. G., 165.Haynes, (Miss) D., 218.Hazen, W., 198.Headley, F. B., 213.Heidelberger, M., 92.Heiduschka, A., 80, 81.Heine, H., 128.Heller, G., 128, 129.Henderson, Y., 177.Herrmann, A., 121.Herwig, W., 164.Hess, K., 67, 126, 142.Heublcin, 0.. 168.Heyn, M., 139.Higgins, H. L., 149.Hill, G. A., 107.Hiltner, L., 212.Hinrichs, G. D., 1.Hintikka, S. V., 11 1.Hirst, C. T., 205.Hirzel, H., 75, 87.Hissink, I). J., 207.Hitchcock. E. B., 205.Hoagiand, D. R., 201.Hoesch, K., 106.Hogan, A.G., 1S1.Holmberg, B., 83.Holtz, J., 117.Hopkins, F. G., 191.Hopwood, F. L., 9, 236, 237.Hostetter, J. C., 242, 243.Hudson, C. S., 76, 77, 7s.Hiittlinger, A., 59256 INDEX OF AUTHORS' NAMES.Hulton, H. P. E., 223.Hume, (Miss) RI., 182, 183, 1st.Humphrey, (4. C . , 223.Hunter, 0. W., 224.Hnrst, L. A., 201.Hurtley, W. H., 71.Huthi, G., 151.Hynd, A., 224.Inczc, G., 162.Isaac, S., 194.Issoglio, G., 158.Ivanov, A. A., 63.Ivanov, IT. N., 165.Jacobs, W. A., 92.Jacobp, M., 192.Jamieson, G. S., 164.Jayson, A. R., 161.Jenner. F. W., 100.Jeiisen, C. A, 221.Jorlander, H., 106.Johnsen, A., 230.Johiison, T. B., 91.Johnston, J., 241.Jones, C. H., 211.Jones, J. S., 219.Jones, T. G. H., 95, 96.Joseph, A. F., 56.,Justin-Mueller, E., 163.Kam, (hllle.) -4.J. H., 68.Kaplanova, (Miss) L., 2RY.Karandeev, V. V., 238.Karaoglanow, Z., 161.Karmanov, S. G., 68, 125.Krtrrer, P., 80, 140.Katz, J. R., 26.Kauffmann, H., 101, 102.Kaiifmann, A., 142.Kaufmann, W. von, 82.Keller, O., 140.Kelley, G. L., 167.Kelley, W. P., 205.Kemp, A. R., 154.Kennedy, C., 155.Kern, J., 209.Kindler, K., 138, 142.Kishida, M., 219.Klee, W., 141.Klemenc, A., 07.Knop, J., 148.Kohayashi, M., 168.Koch, G. P., 200.Kohler, F., 41.Kohler, E. P., 107.Kolthoff, I. M., 169.Komatsu, S., 92.Komppa, G., 110, 111.Kopeloff, N., 206, 213.liowalski, Z., 102.Krauso, E., 73, 11 8, 120.Kraiise, H., 85.Krauskopf, F. C . , 1:'i+.Kiister, C., 05.Kiister, W., 143.Kunder, H., 116.Kuss, E., 48.Kyropoulos, S., 220.La Forge, F. R., 7 8 .Lakhumalani, J.V., 07.Lamb, A. R., 165, 156, 224.Langmuir, I., 7.Lapparent, J. de, 239.Tlnpworth, A., 93, 103.Latshaw, W. L., 151.Lnuder, A4., 186.Lnuschlre, G., 49.LM\ou\-, A., 236.Lchinann, F., 163.Lehinann, 0.. 239.Leiningen, W. (Craf) zu, 19%Lembert, M., 3.Lemkes, H. tJ., 100.Lemp, J. F., 154.Leroux, H., 136.Lesnpe, P., 211.Leuchs, G. .I., 59.Lcvciie, P. A, 71, 77.Lewis, W. C. M., 18, 19.Ley, H., 100.Lidstom, F. M., 147.Liebmann, H., 249.Liebner, A., 14.'.Lifschitz, I., 100, 127.Lindet, r,., 223.Lipman, C. B., 20.5, 21 1.Lipman, J. G., 210.Lloyd, D. J . , 192.Loewe, L., 1.58.Louri6, H.. 127.Lubs, H. A., 150, 201.Lucas, H.J . , 13-1.Liicks, 208.Lye, 0. (2.. 154.Lyman, J. A,, 69, 1.52.Lyman, J. F., 180.Lyons, E., 69, 132.hbedev, S. V., 63.McBain, J. W., 18.McClsndon, J. F., 177.McCollum, E. V., 180, 181, 182, 185,McCool, M. M., 207.McDnvid, J. W., 22.McDole, G. R., 207.MacDougall, (Miss) E., 30.McHrtrgue, J. S., 223.RlacInnes, D. A., 11.223INDEXMackenzie, J. E., 7G.McLaren, D., 73.McLean, H. C., 210.SIcPherson, A. T., 131.JIacri, V., 160.Xadsen, E. H., 72.?rI#rz, S., 200.3lnillard, L. C., 203.Maisch, O., 59.Xaknroff -Seinljanski, J . , 9.5.llnkrinov, I. -1.. 213.Mnksorov, B. V., 69, 126.Jlnllinkrodt, E., 155.’_\Iflingam. -4. W., 76.JIannheini. J., 166.IIannich, C‘., 138.Macliiennc, L., 214.Marden, J. W., 157.Murriott, W.-$I., 1.49.JtarsL, J. E., 154.lIcirtin, G. H., 16, 83.Mason. 1 1 7 . . 23.Massr, R.. 1.56.Nauprii. C’., 239.Mauthner. F., 94.Mawrov, F., 3 i .Jlas, F., 139.?c.last*d, E. B., 30s.llnycr. F., 92. 161.JIechc.1, L. T - o ~ , 79, 90.Mentlel. I,. R., 184.Merki, li-,, 117.Mcrreyn-ether, J . E., 148.JIerton. T. I%., 5 .JIwwin, H. E., 240, 241, 243.Mor.~, &A. R., 212.”yrr. c:. >I., 77.J I ~ y e r , I:.. 62.AIiciitic~l. -4.. 73.1\Iivgc, M., 206.~ I l l l a r , C’. E., 40;.Jliller, \V. S., 1SO.Milli kc??i, J., 43.Jl1ste1. \v. a., 160.Jliyak~., K., 198, 204Jloller, S.. 118.Morller, \I-. , 35.AIoir, #J., 1G3, 169.Molez, I.:., 1.JIoii-ch, IT., 219.‘Jlointer, I?., S1.Slontnpnc, P. J.. 93.Jloore, F. J., 10%I\Iooi*e, S.H., 131.Norey, C:. \IT., 240, 242.Maqp111, ( :. T., 93, 114, 115.Morgan, J . P., 199.JIorriss. \T. H., 177.3iorron-. (*. -4., 20.1.Aliillvr. I.:. . 160.Aiur~l!~. J . It., 194.RIurrny, (Miss) R. R., 107.Jfylius, F.. 31.l{EP.--\‘OL. xiv.OF AUTHORS’ NAMES.Sagai, I., 219.Nametkin, X. X . , 110.Ncidle, >I., 36. 37.Nelson, E. I<., 103.Seogi, P., 86.Newbery, E., 14.Xichols, 31. R . , 150.Nicholson, J. W., 5 .Nierenstein, X., 14.5.Niggli, P., 239, 2 3 0 .Nikolov, M., 37.pr’oll, H., 168.Solte, O., 200, 313.Noinura, H., 103.Nossowitsch, H . , 6 4 .Souri, O., 103.OciOn, x., 219.Oesper, R. E., 164Oesterhelcl, G., 42.Ogq, A . , 9, 336, ‘737.Ohle, H., 55.Olic, J., jun., !I.On4ow, H., 192.Opolski, S.: 99, 101.102.Oppenhrirner, T., 94.O’liiordan, W. M., 143.Or!i(lorff, W. It., 107.Om, (JIiss) A. 11. I < . , 96.Ortmmi, (2.. 210.Ostroinisslcnski, T. I . , 63.O ~ ’ > O Y I ~ P , T. B., I S4.257l’asl, C., 35, 6 3Palkin, S., 1 t XPalmer, H. E., 15.5.Parker, I<., 11.Parsons, T. R., 178, 17%Passarqe, W., 55.Pastt3rnaclc. R., 142.l’nton, I). N., 195.Paul1, w. “3.Pearwn, (Jlrs.) L. K.. 10:;Pcllnt, H., 159.Prrkins, I<. L.. 1.53.i’ettxrs, 1%. A., 179.T’etwson, W., 207.Pfcmniiicpr, I*‘. , 86, 87.i’hclps, J. I<., 135.Pickering, S. U., 2118.l’igulcvski, G. IT., 2%.Pilewski, J., 102.Pitz, W., 181, 152, 2.‘::.Plachutn, N. I., 62.Plaisance. G . P., 224.Plum, H. M.. 136.Poch, J’., 167.POdSIUS, E., I S .rJdgLle, J.E., 212.PfPiffer, r., 7 , 99, 102, 1 l b . 119. 22:Pollnk, R., 93.I258 ISDEX OF ATI‘I‘HORS’ SAMES.Pooth, P., 253.Porter, L. E., 161.Powell, A. D., 166.Prianichnikov, D. N., 217.Prideaux, E. B. R., 1.57.Prosad, K., 92.Prsheborovski. J. S., 13.Puchner, H., 207.Pulling, H. E., 207.Pynian, F. L., 140.Qua, X. C., 7 3 .Quercigh, E., 241.Rabe, P., 142.Rabinovjtsch, A. T . , 13.Radford (airs.) X., 159.Rae, JT. S.. 18, 56.Raffo, >I., 127.Raistrick, H., 191.Rakshit, J. S.. 160.Ramann, G., 199, 200.Rnmsay, A . .4., 162, 214.Rankin, G. A . , 243.Kao, 13. s., 149.Rathshurg. H., 39.Rau, 31. G., 95.Ravcniia, C., 220.RAY, 1’. C., 44, 51, 89.Ray. R. C., 46.Read, ,J., 72.Reich, S., 117.Reid, E.E., 69, 152.Rcindcrs, IT., 24.Reitstiitter. J.. 36.Rettger. 191.Richards, F,. H., 209, 211.Richards, T. JV., 2.Richardseii, A . , 223.RicIiardso~i, 0. ITr., 5.Richmond, IT. I)., 148, 155.Richmond, 1’. E., 210.Richter. 31. &I.. 70.Riwenfeld. E. H., 54.Rinne, F., 7 , 22Q, 230.Ritter, G . , 1.74.Rittmnn, W. F., 62.Ritzman, E. G., 2224.Robertson, t i . S., 214.Robertson, T. B., 187, 190.Robinson, (111.9.) G. 31.. 96,132.113, 117,Robinson, G. W., 208.Robinson, R., 93, 96, 115, 119, 132,Robinson, R. H., 204.Rodd, E. H., 50.Rodt, V., 55.Rohmann, F., 184.Roschier, R . H., 110.135. 136.Rose, Jf. S., lS7, 2 2 3 .Rosiclii, V., 235.Ross, W. H., 212.Rossi. C., 216.Roth, C., 6.5.Rotlilin, E., 1-12.Royle. F.A., 103.Rudnick, P., 58.Ruff, O., 49, 59.Ruggli, P., 129.Rupe, N., 52.Rupp, E., 121, 163.Rushenceva, (Jllle.) A. K., 110.Russell, E. J . 204, -306, 209.KuziEka, L., 109.Ryan, H., 14.5.SacIimov, A. S., 13.Sacher, J. F.. 148, 16.5.Saillard, E., 220.Sasaki, T., 190.Sastry, S. G., 21.Savini, G., 169.Sawyer, H. L., 7G.Saxton, 13.. 34.Scharf, $3.. 7 3 .Scharvin, V. I.., ti?.Scheffer, F. I?. C . , 7 , 19, 229.Scherrcr, I).. !I, 22G.Schjcldrrup, H., 8, 229.Schlcnk, W., 117.Schrnidt. E:., 89, 142, 209.S clim o eger . 20 Y .Sclineidcr, W., 7 7 . 81.Sclinorr, IT-., 247.Schonflies, A., 230.Scliofieltl, C. S., 119.Schollenberger, C. .J., 2 0 1 .Schott, J. E . , 1.3;.Schramm, \V.H., 1 6 1 .Schroedcr, P. J., 2 1 1.Schroetcr, G., 7.5, 10s.Schryvcr, S. H., 21s.Scllulze, H., 142.Schuppli, O., 151.Schweiger, J., 53.Scott, s. E., 161.Scidenberg. A . , 1.57.Seliqman, R., 4.5.Scnter, G., 16, 17. 72, 83, $1.Scpp, J.. 77.Scufert, R., tiG.Rharpe, J. E., 193.Bhedlov, X., 177.Sheppard, 8. E., 1-17.Shibata, K., 219.Shipley, J. W., 148.Shorey, E. C., 151, 198.Shixey, P. &I., 152.Siegbahn, M., 3 .Sieger, H., 80.Siegwnrt, J., 87IKDEX OF AUTHOHS' SXMES. 2.59Sieverts, -I., 150.Siniinunds, S., lS1, 223.Simonwii, J. L., 95.Sjostrom, F. W., 42.Sjolleina, B. J., 68.Skrabal, -I., 17, 41.Slyke, D. D. van, 173, 175, 176.Sinitti, .T. H., 38, 162.Sillits. X., 6, 18, 2251.SOP. Chern. Ind.Haslth, 93.Sotlerhntini, H. G., 209.Sosinan, R. B., 242, 243.Sperk, --I., 17.S p e y ~ r , E., 138.Strwkmnim, L., 93.S t a r k . J., 7 .St'andinger, H., 7 5 , 88. 87.Stearii, -4. E., 43.Stetnl.wrpen, H. D.. 170.Stcc.nboc.li, H., 223.St,einliopf, W., 123, 124.Stenst,riim, w., 3 .St.e.M.art,, A. w., 30.Stewart, R., 205, 207.Still, C. J., 84.Stillman, E., 176.Stock, A , , 48.Stoldasti, J., 213.Ktolt.zenberg, H., 4sStreriiine, H., 200.St,rufP, K., 139.Sturgee, 191.Stutzer, A., 201, 209.Sudborough, J. J., 97, 99, 100.Swanson, C. O., 224.Sweet, J. I<., 194.Synt,hetic Hydro-Carbon Co., (52,Kzyszkowski, R. de, 12.Soddy, F., 2.TaSue, E. L., 224.Tartar, H. l'., 204.Taylor, H. S., 16.rritvior, J., 88.rraylor, IV.A., 10.T(.llcr, C:. L., 78.Teqxmy, H. A., 198.7'hoin;tb, J., 93.'rholnds, (Miss) R. JI., 10s.r~holllsoI~, w . , 177.Tliornton, W. 31.. 20, 21.'t'iede. E., 32.Tillrnans, J., 168.Tornlins, H. P., 114.rrrauije, TV., 54, 5.5.Tra\.ers, 165.'rravers, M. W., 46.'rronov, B. V., 68, 125.'rropsch, H., 54,Troussov, A. , 202.Truskier, P., 119.T,chelincev, V. V., 68, 69, 125, 126.Tricker, S . H., 83.Turpin, H. W., 207.'rutton. -1. 12. H., 9, 23G, 237.Tnoinry, T. J., 62.Valeton, J. J . E., 250.Vgdorcik, d., 157.Vinccnt, C., LUO.Viola, C., 8.V o d c l i ~ r , J. A., 213.Voigt, K., 7 3 .VotoEek, E . , 'is.T'egard, I,., 8, 229. 233, 23-4, 236.I'oigt, w., 239.\t'aksmaii, 8. Al., 305.LValters, E. H., 130, 203.Wmner, H. W., 210.Washhurn, 13. W., 10, 11.Washington, H. S., 242.\Vatkin, H., 146.Weerman, R. --I., 77.\Vehmsr, C., 221.\Veil, F. J., 144.\Z7einlancl, I<. F., 5 3 .Weiss, J . Ji., 13(i.Wells, L. S.. 221.Wells, K. C., 241.Werner, E. A. 66. 88, 209.Wesche, H., 62\Yesener, J. A., 78.\Vheeler, R. V., 21, 23.Widman. O., 106.Wiessmann, H., 59.Wild, S., 83.Williams, C. &I., 234.Williams, H., 168.Williams, (Miss) 31. M., 72, 9 G .Williams, P., 45.Williams, R. R., 185.Williamsoii, 13. D., 241.Willstatter. R., 144.Wilson, E. D., 28.Wilson, (Miss) El. G., 158.Wilson, J. B., 210.Winciaus, A, 111, 112.Winfield, G., 194.Winkler, L. W., 168.Wise, L. E., 151, 203.Wjslicenus, W., 74, 98, 99.Wisselingh, C. van, 219.Witt, J. C., 36.K 260 IXDEX OF AUTHORS' NAMES.Wohl, A., S4.Woker, G., 81.Wolff, G., 163.Wolkoff, M. I., 2 0 i .Wood, H., 16, 72.Woodhouse, (Miss) K., 82, 222.Woodman, H. F., 222.Wren, H., 84.Wright, F. E., 238.Wright, R., 30.Il'ulzen, R., 189.Wybert, E., 91.Wykes, F. H., 93, 103.Yanovsky, E., 7G.Young, H. D., 220.Young, S . W., 43.Zacharski, J., 99.Zarzecki, T. von, 105.Zies, E. G., 240.Zilva, S. S., 185.Zirkel, H., 81.Zollinger, E. H., 144.Zsigmondy, R.. 35.Zwislocki, T., 101.Zyl, J. P. va,n, 200

ISSN:0365-6217    

DOI:10.1039/AR9171400253

出版商:RSC    

年代:1917

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Acetaldehyde-ammonia, reactions of,Acetic acid, preparation of, 69.Acetic anhydride, preparation of, 69.Acids, aliphatic, aryl substituted,67.preparation of, 93.halogen, 72.fatty, detection of, 152.estimation of, 155.organic, and their derivatives, $9.strong, catalysing power of, 16.detection of, 152.detection of, 153.Agricultural analysis, 150.Alcohols, 64.Aldehydes, 65.Alkaline reserve of the body, 171.Alkaloids, theory of synthesis of, inplants, 135.cinchona. 141corydalis, 141.ipecacuanha, 139.morphine, 137.estimation of, 159.Aluminium, action of acids 011, 45.Amines, preparation of, 85.Amino-acids, 89.Ammonia, estimation of, in soil, 150.Ammonium compounds, organic, 117.iodide, crystalline form of, 233.Analysis, agricultural, 150.electrochemical, 166.gas, 148, 177.inorganic, 160.organic, 162.physical, 146.-Znatase, crystalliiie form of, 2 3 3 .Aniline, estimation of, 156.Anthocyanins, 144.Aragonite, 241.9rgon, separation of, from air.150.Arsenic organic compounds, 124.Arylamines, secondary, preparation of,Stoms, genetic relationships between,93.o rAtomic structure, 3.weights, 1. 27.Azoxy-compounds, 11 3.Bacterial growth, 190.Bases, cyclic, relative stahility o f . 130.$-Bases, condensation of, 132.Benzaldazine, action of cyanic acid on,Benzene, halogen derivatives, 94.Benzoic acid, detection of, 162.Bile pigments, 142.Bilirubin, 142.Bismuth, preparation of, 5 1.chloride, compounds of, 53.Body, alkaline reserve of the, 1 i 1Boron compounds.46.Brochantite, 43.cycZoButanr, derivatives of, l o b .Butyric acid, estimation of, 133.Cadmium, estlintttion of, 164.nitrite, 44.Czsium doublr fluorides. 41.Calcite, 24 1.Calcium, detection of, 16 I .estimation of, 1GG.carbonate, forms of, 211.basic phosphates of 43.130.Caoutchouc, 63.Capillarity theory, Curie’s, 243.Carbamicles, 88.Carbon, detection of, 160.estimation of, in soil, 151.dioxide, estimation of, 149. 131, 168,suboxide, 47.177.Carbonyl sulphide, 48.Catalysts, endogenous, 187.Ceric hydroxide. colloidal solutions of,Chemical constitution and colour, 99.23.dynamics, 15.equilibrium, 19.reactivity, radiation hypothesis of,18262 INDEX OF SLJBJEC’I’S.Chlorine, estimation of, 169.C‘hloroplatinic acid, preparation of, 58.Cholesterol, 1 1 1 .Chromium, estimation of, 164.Chrornoisoinerisiu, 102.Cinchona a,lkdoids, 14 1.Cobalt,, estimation of, 166.Colloids, 23, 34.Cswelling of, 2G.Colour and const,itution, 99.Colouring matters of plants, 144.Copper, detection of, 160.salts, 33.urnny I phosphate, crystallographysulphate, the sysfvem, copper oxide,of, 242.watort and, 43.Corydalis alkaloids, 141.a-Crotonic acid, occurrence of, in soil,Cryptoimrnerism, 102.Crystal faces, solubility of, 260.203.growth and dissolution, 246.structure, 6.relative swlocities of, 249.Federov’s work on, 230.S - r a y method of exploring, 2-38.tion of, 249.Crystals, relative velocity of dissolu-dissolving, curved surfaces of, 247.growing, linear force of, 239.stability of t,he plane surface on,246liquid, 239.Cy mioh ydrins, G 8.Cyanuric acid, occurrence of, in soil,203.Desmotropic compounds, 97.Diabetes, 194.Dialkyl carbonates, rate of hydrolysisof, 17.Diazo-compounds, aliphatic, 8G.Diazophenols, 11 4.Dindole, 129.Dioxiiidol?, sodiurn salts, colour of, 128.3 : .j’-Diphetiyldtliydro-l : 2-iriazolo-triamle, 5 : 3’dihydrouy- 130.Disaccharides, 80.Dissociation, ionic, 11.Dopamelanin, 196.Dopaqxydase, 196.Dynamic isomerism, 97.Electrical conductivity of solutions, 10.Electi~ochemical analysis, 166.Emetamine, 140.Endogenous catalysts, 187.Enrichment of minerals, secondary,Equilibrium, chemical, 19.Esters, 73.240.Ethyl alcoHol, estimation of, 134.Ethylenc~ oxides, 103.estimation of vater in, 1.55.EuteCt I C St J’liCt lll‘f’s, 239.Fats, analysis of, 13i.Feeding stuffs, 22-3.Ferichenes, nomenclatiire of, 110.Fenchone, synthesis of, 109.Fermentation, ’324.Ferric trisulphidp, 38.Fer t i l i s e r ~ , 2 08.Fo rmal de h ydr, i n t t h y la t 1 on ~v i t il , 0 6,93.Galactobioses, 80.d-Galactose, detection of, 1.34.Gallium, metallic, 44.detoction of, 161.Gas analysis, 148, 177.Gaseous mixtures, electrical ignition of,Gelatin, structure of, 23.Germanium, detection of, 161.Ginger, pungent principles of, 103.Glucinum, melting point of, 42.Glucosides, 79.Gliitamic acid, crystallography of saltsof, 238.G!ycerol, diatmino-, cl- and E- forms of,82.Clyosal, $7.Gold, crystalliiit: form of, 233.Growth, 187. ---20.metnvaimdatc, 44.bacterial, 190.G uariidine in metabolism, 193Halogens. estimation of, in organicHalogen acids, aliphatic, 72.Halogenation. 92.Heterocyclic rings, new, 119.Hydrates, crystalline, rate of dehydra-Hydrazines, fission of, 1 13.Hydrazobenzenes, substituted, decom-Hydruzones, autositlation of, 11G.Hydrocarbons, 6 1.Hydrocyanic acid, detection of, 133.Hydrocyclic compounds, 107.Hydrogen peroxide, detection of, 1G1.Hydrouy -acids, azides and hydrazidescompounds, 154.tion of, 18.position of, 116.of, 87.Ignition, electrical, of gareous mixtures,Ignition-temperatures, determinationIndigotin, constitut~on of, 127.Indole, a doubly condensed, 129.Indole group, the, 127.20.of, 2 2 ISDES OFhorgniiir analysis,Intramolecular change, 117.totlides.detcxtion of, 161.lodometry, 163.Conic dissociation, 1 1 .Ipecncuanha allialoids, 139.Iron, separation of. 165.sulphide, evaluation of, 16s.1<i>tins, isorncrisrn i n the, 129.Iwtin coinpoiinds, c o l o ~ ~ r o f , 128.Isiltol, 129.Isomerism. dynamic, 97.l.;otopes, 2.coinpouiids, structure of. 10, 33.Jellies, structurc of: 2.3.I,ch;Ltl. crystalline form of. 233.c.stiinut.ioii o f , 148.organic coiiipo~mds, 11S, 1’20.Licliens, colouring matters of, 14.5.T,i (1 ui ds ~ a 1 iisn t ropic . 2 3 9.Litliiiiin, estimatioi! of, 169.Magnesinrn, estinlation of. lG4.sulp?iidt, p h o s p l ~ o r ~ ~ s w n ~ ~ of, 3 2 .JI,zndcloiiitrite-filncosidt..synt,llesis o f ,Manganese, detection of, 160.JEsiiiiulietoheptose, 7s.31annosc, preparatioii o f , 76.31a11ure7 208.Meconic acid, const itutioii of, 51, 131.3lri.curic oxide, iise of, in \ToliimetricJlereury, estjmntion of, in organici 9 .analysis, 162.eoIIIpoUndS, 154.organic coriipounds, 120, 123.Jictrtbolim~. influence of guanidiiic in,influcnw of t,hc paiicw:w in, 194.195.3Iet,h~lI,sycliotriile, 140.Mc:~liyl-i*(d, as a.n indicator, 162.Milk, 224.JIiiiera.1 systems, thermal stucties of,JIolecular hypothesis and crystnlMolybdenuin, estimntioii of, 161.Morphine allialoicts, 137.SaphthoZs, detection of, 133.Sickel, sepratjon of, 166.Sitrat,es, est,imat,ion of, 150, 169.Xitro-compounds, arornat,ic, coloiir of,‘42.struct.ure, (5.pentasiilphide, 57.99.Xiti~ogeii, estiiiiat ior) of, 131, I(ie5.coinpouiids.tiroiiiatic, 1 1 3 .organic, S4.trichloride, 51.Sitroils acid, 52.Nutrition, I i 9 .Oils. analysis of. 13i.Optical :tcti\-ity. S 2 .Orgaiiic analysis. 152.Organo-metallic coin1munds. 1 1 S.Osmiiim oxidr.s, 59.Osalic acid, use o f . in alkaliiiit~t ry, 1 Ci?.Oxygen, estirnatioii o f , 1 6 3 , ! (is.Ozonates, 54.Ozo11c, rcactiolls of, 54.estimation o f , 14s.Ovc~l*volt,ape, 14.I’m ic‘ I Y > ~ S , i 11 f l iieiic~ ( ) f , i l l iiiot a1 )ol is111 ,Partticlia suzntilis, colotiriiig mattc>rPerchloric wid, detectioii o f , 16-3.Phenol, estimation of, 156.Pl-ii~iiols, detection of, 148, 152, 153.polyhydric, nlkyl et,hers of.9.5.Phc :nolp h t ha1 e iiio xi in r- , dec o m p o s i t io iiPlilort: t i 11, synt,l ic.sis o f , 105.Phosplintvs, coilstitiit.ioii of, 38.P 11 osp lio rescencc , 3 0.Phosphoric acid, cstimatioii o f . 131 ,194.of, 145.of, 106.162.acids, tit,r*ntioii of, 38.PIiosplior11s, dc.tcAct ioii of: 160.Pht.lialeins, 10Pigrnciit, foriiintio~i of, i l l the. skin, 195.Pigments o f bile, 142.l’ipcridint, 1 ?{ti.I’lnnt growtl1. 21 t , 213.yoisons, 22 1.Pln n t s, t h r x o ry o f a1 li nl c) i d a1 sy ii t.11 csi Hi i l , 1:15.coiiatitriciits of. 218.t:olouririg inatters of. 144.elect rotles, subst.itutt.s f u r , 16i.Plat iiinni, cstiriint ioii of, 166.Polypeptides.90.I’olysacchnridw, YO.I~’otassiuiri diuliro~nizt~e, use of, iii\~oluniet.ric analysis, 162.OZOllatf’: 54.stniinichloridr, prepnratioii of? 4 1 .Principle of varjatble states, 103.cycZoI’ropane, tleri\rati\-rs of, 107.Pyridine, 126.Pyrolusite, analysis of, 163.Pyrrole and its derivatix-es, 124.condensation of lietolies and, 68264 INDEX OFQ uebrachine, 141.Quercitol, crystallography of, 338.Quiiiliydrnncs, colour of, 99.Radiation hypothesis of chemical re-X-Rays, in\-cstigat,ion of crystds by,Reactivity, chemical, radiation hypo-Reduction, 92.Regulator mixtures, 17.Resorcinol, detection of, 163.Rhodiuni oxides, 59.Rocks, igneous, origin of, 245.Rubidinm dou!,!e fluorides, 4 1.Ruthenium oxides, 59.Rutile group, cryqtalline form of the,actions, 18.-- .,.?&t!iwis of, 1s.‘3-1.Salvianin, 144.Santene, syiitliesis of, 1 LO.Sedoheptosc.. i 8 .S(-!enates, tioirble, crystallography of,Silica, estimation of, 165.Silver, crystalline form of, 333.2 3 7 .estimation of, in organic compounds,clironiate, rhythmical precipitationcyanide, structure of, 86.peroxynitratc, 40.151.of, 41.Skin, formation of pigment in the,Sodium ferrocyanides, crystallographyhypoehlorite.conversion of, intopolyphospliate, 40.Soil, chemistry of, 197.formation. 207.physics, 206.surveys, 208.Solaniche. 219.Solnnine, 2 19.Solutions, electrical conductivity of, 10.Sozoiodol-mercury compounds, 120.Spectra, emission, 5 .Starch, 81.~5timation of, 159.Strontium, estimation of, 169.196.Qf, 238.elllorate, 5 i .SUBJECTS.Sugars, 75.Sulphides, organic, cyclic, 121.Sulphuric acid, estimation of, 145.Systcms, conjugated, criss-cross addi-mineral, thermal studies of, 242.estimation of, 158.tion to, 130.Terpenes, 107.Tetany, 195.Tethelin, 190.Tetmmet2iylainnioniuni iodide, crystal-line form of, 233.‘rctramorpliimi, ILPW ~ ; l ~ c of, 238.Thicnyl ketones, 1.24.Thionyl chloride, preparation of anhy-Thiophen cortipound~, 123.‘l?hymolplithnlein, as <in indicator.163.Tin compounds, 50.Toluene, nitro-compounds, estimationof, 157.p-Toluidinc,, 3 : 6 dmitro-, tetramor-Toplc axes, 236.Tropinone, synthesis of, 134.Tryptaminc, 192.Tyroaylglycine-hydantoin, 91.Uric acid group. the, 138.Valencp, 33.Valency volume theory, 236Vanadic acid, reduction of, 63.Velocity of reactions, method ofViolanin, 144.Viscosity, determination of, 147.Vitamines, 184.drides with, 70.phism of, 238.in plants, 136.recording, IS.\Valden inversion, 16, 83.Water analysis, 168.Weights, atomic. See -4tomic weights.Xanthogal!ol, 108.Yohimbine, 141.Zinc peroxide, 42.Zirconium CompoEds, 48.sulphide, phosphorescence of, 30.PRISTED IS GREAT BRITAIN BY R. CLAY AXD SONS, LTD.,BRGNSWICK STREET, STAMFORD STREET, S.E. 1, AXD BUNQAY, S L l t b I K

ISSN:0365-6217    

DOI:10.1039/AR9171400261

出版商:RSC    

年代:1917

数据来源: RSC