摘要:

ANNUAL RKPORTSON TAP,PROGRl<SS O F CHEMIS'I'RYANNUAL REPORTSJ. N. COLLIE, P1i.D.) F.R.S.A. W. CROSSLEE-, D.Sc., Ph.D., F.R.S.ON THEJ. C. PHILIP, D.Sc., P1i.D.F. L. PYMAN, D.Sc., Ph.D.PROGRESS OF CHEMISTRYE. C. C. BALY, F.R.S.T. V. BARKEX, M.A., B.Sc.H. 111. DAWSON, D.Sc., Ph.D.F. G. HOPKINS, M.A., M.B., D.Sc.,F.R.S.F O R 1915.J. C. IRVINE, D.Sc., Ph.D.G. CECIL JONES, F.I.C.N. H. J. MILLER, P1i.D.F. L. PYMAN, D.Sc., Ph.I).A. W. STEWART, D.Sc.ISSUED BY THE CHEMICAL SOCIETY.tllbifor :J. C. CAIN, D.Sc., Ph.D.$3 ub- 6;bitor :A . J. GREENAWAY.&3saiatrrat %Tsub-&;bitrrs :CLARENCE SMITH, D.dc.VOl. XII.LONDON:GURNEY & J A C K S O N , 33, PATERNOSTEll ROW, E.C1916PBINTED I N GREAT BRITAIN BXRICHARD CLAY ANTI SONS, LIMITED,BRUNSWICK STREET, STAMFORD STREET, S.E.,AND BUNGAY, SUFFOLKCONTENTS.PAGEGENERAL AND PHTSICA4L CHEMISTRY.By H. M. DAWSON, D.Sc.,INORGANIC CHEMISTRY. By E. C. C. BALY, F.R.S. . . . . 27Part ~.-ALIPHATIC DIVISION. By J. C. IRVINE, D.Sc., Ph.D. . , 63Part II.-HOMOCYCLIC DIVISION. By F. L. PTMAN, D.Sc., Ph.D. . . 88Part III.-HETEROCYCLIC DIVISION. By A. W. STEWART, D Sc. . . 128ANALYTICAL CHEMISTRY. By G. CECIL JONES, F.I.C. , . . . 171PHYSIOLOGICAL CHEMISTRY. By F. G. HOPEINS, M.A., M.B., D.Sc.,F.R.S. . . . . . . . . . . . . 187AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.By N. H. J. MILLER, Ph.D. . . . . . . . . 210MINERALOGICAL CHEMISTRY. By T. V. BARKER, M.A., B.Sc. . . 234P h . D . . , . . . . . , . . . .1ORGANIC CHEMISTRY :A . . . .Avner. J. Ph?;siol.Ainer. J. Sci. .Analyst . .knnalen . .Ann. Bot. . .Ann. Chinz. .Ann. Chim anal.Aim. Chim. ApplicalaAnn. Chim. . .Ann. Inst. Pasteur .Ann Physik . .Ann. Physique . .Ann. Report . .Apolh.-Zeit. . .Arch. Int. Med.Arch. Pharm. . .Arkiv. Xem. Mia. Geol.Atti E. Aced. LiiLcei .Ber. . . . ,Ber. Deut. hot. Ges. .Ber. Deut. yharm. Ges.Ber. Dcut. physikd. Ges.Bied. Zent?-. . .Bicchent. Bull. . .Biochem. J. . .Biochenz. Zeitsch. .Bull. Soe. chim. .Bull. Soc. franc. Min.Centr. Bakt. Par. .Chew&. Nmx . .Chem. FVeeWnd .Chm. Zeil. . .Chin. Zentr. . .Compt. rend. . .Gazzetta . . .Gummi- Zeit. . .Inter. Zeitscl~. Phys. -chenz.Biol. . . . .Jahrb. Radioaktiv.Elek-tronik . . . .J. Agric. Sci. . . .REFERENCES.TABLE OF ABBREVIATIONS EMPLOYED IN THEThe year is not inserted in references to 1915.JOURNAL.Abstt acts in Journal of the Chemical Society.Anierican Jouriial of Physiology.American Journal of Science.The Analyst.Justus Liebig’s Annalen der Chemie.Annals of Botany.Annales de Chimie.Annalrs tie Chiiiiie analytique appliqnde h l’hdiistiie,Annali di Chiniica Applicata.Annales de Chimie.Annales de 1’Institut Pasteur.Annalen der Physik.Annales de Ph ysiqne.Annual Reports of the Chemical Society.Apotheker Zeitung.Archives of Internal Medicine.Archiv dcr Phnrniazie.Arkiv for Kemi. Mineralo4 och Geologi.At ti della Reale Avcadem7a dei Lincei.Berichte der Deutschen cliemischen GesellschaftRerirhte iler Dentschen botanischen Gesellschaft.Herichte tler Deutschen pliarmazeutischen Gesell-Bericlitc dcr Deutsclicn physikalisclien Gcsellscliaft.Biedermatiii’s Zentralblntt fiir Agrikulturcliemie nndBiochemical Hullet in.The Riochemicd Journal.Biocheniische Zeitwhrift.Bulletin dc la SociQtd ehimique de France.Bulletin de la Socidte’ franqaise de MinBralogie.Centralblatt fiir Bakteriologie, Parasitenknnde nndInfektionskrankheiten.Centraleblatt fiir Mineralogie, Ceologie 11 n d Pa-laeon tologie.Chemical News.Cheinisch Weekblad.Chemiker Zeitung.Ciiemisches Zentralblatt.Comptes rendus hebdomadaires des Sfances deGazzetta chimica italiana.Gummi-Zeitung.111 ternationule Zeit schrift f i r physikaliscli d i e m ischeJshrbuch der Radioaktivitiit und Elektronik.b I’Agriculture, B la l’harmacie et h la Riologie.schnft.rationellen Landwirtschafts-Betrieb.1’Acade’mie des Sciences.BiologieJournal of Agricultural Scienceviii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.J.Anzer. Chcm. SOC. . .J. Siol. Cheiii. . . .J. Bd. Agric. . . .J. Ind. Eng. Chem. . .J. Phnrm. Chim. . .J. Physical Chcm. . .J. Physiol. . . .J. pr. ChenL. . . .J. Rq. Agric. floe. . .J. Russ. Php. Chem SOC. .J. SOC. Chm. Ind. . .J . Wcishington Acad. Sci. .Kolloid- Zeitsch. . .Lnndw. VemrcJwStat. .Monatsh. . . . .Aion. Sci. . . . .Nzrovo Ci7L * . .Phawn. J. . . . .Phnrm. IVcekbLnd . .Phil. Meg. , . .Physiknl.Zeitsch. . ,P . . . . * .Proc. Cainb. Phil. SOC.Proc. K. Akad. Wetc?mh.Amsterdam. . . .Proc. Nett. Aced. Sci. . .Proc. hoy. Soc. . . .Proc. Roy. SOC. Edin. .Rcc. tyav. china. . . .Sci. Proc. Boy. Dubl. SOC. .Sitzunysber. K. Aknd. Wiss.Berlin. . . . .Stat. spcr. agmr. Itnl. .T . . . . , .Trans. Faraday Soc. . .Tmns. Xoy. SOC. Cnfinda .Zeitsch. anal. Chem. . .Zeitsch. angew. Chenz. .Zeitsch. nnorg. Cliem. . .Zeitsch. Biol. . . .Zeitsch. Eleklrochcm. . .Zeitsch. Kryst. Min. , .Zeeitsch. physikal. Chem. .Zeitsch. physiol. Chem. .Zeitsch. wiss. Mikroskop.JOURNAL.Journal of the American Chemical Society.Jouinal of Biological Chemistry, New York.Journal of the Board of Agriculture.Journal of Indnstrial and Engineering Chemistry.Journal cle Pharmacie e t de Chiinie.Journal of Physical Chemistry.Journal of Physiology.Journal fur praktische Chcniie.Journal of the Royal Agricultural Society.Journal of the Physical and Chemical Society ofJournal of the Society of Chemical Industry.Journal of the Washington Academy of Sciences.Kolloid-Zritsc hrift.Die landwirtschaftlichen Versuchs-Stationen.Rlonatshefte fur Chemie nnd verwandte Theile andererMonittwr scientifique de Qnesnevillc.I1 Kuovo Ciinento.Tho l’harmaceutical Journal.Fharmaceutisch Wcekblad.Philosophical Magazine (The London, Edinburgh andPhysikalische Zeitschrift.Proceedings of the Chemical Society.Proceedings of the Cambridge Philosophical Society.Koninklijke Akadeniie van Wetenschappen te Anister-Proceedings of the National Academy of Sciences,Proceedings of the Royal Society.Proceedings of the Royal Society of Edinburgh.I:,.cneil des travaux chimiques des Pays-Bas et de laBelgiq ue.Scientific Proceedings of the Royal Dublin Society.Si tzungsberichte der Koniglich Preussischen Akademieder Wjssenschaften zu Berlin.Stazioni sperimentali agrarie Italiani.Transactions of the Chemical Society.Transactions of the Faraday Society.Transactions of the Royal Society of Canada.Zeitschrift fur analytische Chemie.Zcitschrift fur angewandte Chemie.Zeitschrift fur anorganische Chemic.Zeitschrift fiir Biologie.Zeitschrift fur Elektrochemie.Zeitschrift fiir Krystallographie und Mineralogie.Zcitschrift fiir physikalische Chemie, SttkhiometrieHnppe-Seyler’s Zeitschrift fiir physiologisthe Cheniie.Zritschrift fiir wissenschaftliche Elikroekopie u i dBussia.Wissenschaften.Dublin).dam.Proceedings (English version).JVashington.iind Verwandtschaftslehre.mikroskopische Technik

ISSN:0365-6217    

DOI:10.1039/AR91512FP001

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.THE year’s work cannot be said to contain any outstandinginvestigation such as cliaracterised that of 1914. On the otherhand, in spite of the fewer number of papers published, the recordof work is one of considerable interest t,o the inorganic chemist. Itwould perhaps be invidious to make special reference to anyparticular investigation, f o r such cannot but largely be a questionof the personal element.Atomic Weights.I n its Annual Report the International Committee has adoptedchanges in the atomic weight of the elements carbon, helium, lead,lutecium, praseodymium, radium, sulphur, tin, uranium, ytterbium,and yttrium. I n the case of helium (4*00), radium (226*0), andytterbium (173.5) the new values were mentioned in last year’sReport on Inorganic Chemistry.The’ work leading t o the newvalues for the remaining elements may be briefly described asfollows :Cnrbo~/.-The new value of 12.005 that has been adopted forcarbon is based on the neutralisation of pure fused sodium carbon-ate with hydrobromic acid.1 The relation between liydrobromicacid and silver was separately determined.Lead.-Lead bromide was analysed by dissolving the pure fusedsalt in dilute acetic acid and then quantitatively treating it witha solution of silver nitrate, the silver bromide also being weighed.The value of 207.19 was obtained f o r the atomic weight. A similarmethod with lead chloride gave the value of 207*21.293 The meanvalue, of 207.20 has been adopted by the Committee.I n connexion with the recent work on the isotopes of lead itmay be mentioned that in the above work eleven specimens oflead salts were obt,ained from non-radioactive sources, but noevidence of any dissimilarity was found.1 T.W. Richards and C. R. Hoover, J . Amer. Chem. SOC., 1915, 37, 95;A., ii, 96.2 G. P. Bexter and T. Thorwaldson, ibid., 1020; A . , ii, 455.a G. P. Baxter and F. L. Grover, ibid., 1027; A., ii, 456.228 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Some further work has appeared on the atomic weight of leadof radioactive origin.4 Twenty kilograms of purest selectedJoachimsthal pitch-blende were extracted with pure reagents, andthe lead thus obtained had an atomic weight of 206.405. A crystal-line uranium ore from an old primary geological formation inMorogoro, German East Africa, gave lead with an atomic weightof 206.046, whilst broggerite from Moos, Norway, gave 206-063.The arc and spark spectrum of common lead and lead with anatomic weight of 206.046 showed absolute identity.This identitybetween the, spectra of common lead and lead from radioactivesources has independently been confirmed between the limitsh=3500 and h=4100.5 An accurate investigation of the spectrumline with a wave-length of h=4058 with a Fabry and Perot Qtalonmade with both types of had showed that if there be any differ-ence in the wave-length of the lines in the two cases, such differencemust be less than 0.003 Angstrom.Prnseodymiurn.-Pure praseodymium chloride was prepared inthe following way 6 : Ten kilograms of praseodymium ammoniumnitrake containing much lanthanum and cerium salts were sub-mitted to a prolonged fractional crystallisation from dilute nitricacid. The pure salt was then converted into oxalate and thenignited to the oxide.The oxide was dissolved in nitric acid andagain precipitated as oxalate and then again ignited t o oxide. Theoxide was then dissolved in hydrochloric acid and the chloridethree or four times recrystallised by passing hydrogen chlorideinto the concentrated solution a t Oo. The atomic weight by pre-cipitation with silver nitrate was found t o be 140.92. The valueof 140.9 has been adopted by the International Committee.SuZphur.-The molecular weight of sodium sulphate was deter-mine'd by conversion of pure sodium carbonate into sodium sul-phate, the molecular weight of sodium carbonate having beenpreviously detpermined.7 .The atomic weight of sulphur was foundto be 32.06, taking carbon as 12.005.li~,aitiitm.--Uranium bromide was prepared by heating a mixtureof uranium oxide and carbon in bromine vapour. The atomicweight of uranium was determined from the ratio UBr, :AgBr,and was found t o be 238-175.8 The International Committee hasadopted the value 238.2.4 0. Honigschmid and Mlle. S. Horovitz, Monatsh., 1915, 36, 355;5 T. R. Merton, Proc. Roy. s b c . , 1915, [ A ] , 91, 198 ; A , , ii, 119.6 G. P. Baxter and 0. J. Stewart, J . Amer. Ghem. Soc., 1915, 37, 516;8 0. Honigschmid, Zeitsch. Elektrochem., 1914, 20, 452 ; Gompt.rend., 1914,A . , ii, 636.&4., ii, 263.158: 2004; A . , 1914, ii, 662.7 T. W. Richards and C. R. Hoover, ibid., 108; A., ii, 96INORGANIC CHEMISTRY. 29Tiri .-Staiinic chloride was prepared by direcb union of itselements and purified by fractional distillation.9 A portion of thefinal fraction of this purified material was further fractionatedtwice and collected in weighed bulbs in a sealed and exhaustedapparatus. The solutions for analysis were prepared by breakingthe bulbs in dilute nitric acid containing either oxalic acid o rtartaric acid, and were then treated with a slight deficit of silvernitrate. The slight deficit of silver was made up by the additionof a measured volume of a dilute standard silver solution. Theprogress of the titration and the attainment of the end-point wereascertained by nephelometric measurements.Fifteen distinctfractions of stannic chloride were analysed, and the atomic weightof tin was found to be 118.70.Lutetium.-Ytterbium was fractionally separated into ytterbium(neoytterbium) and lutecium.1° The atomic weight of both elementswas determined by conversion of the oxalate into the oxide, andthat of lutecium was found to be 175.0, a value which has beenadopted by the International Committee.Yttrium.-The atomic weight of yttrium was determined by thoconversion of yttrium sulphate, dehydrated a t 400°, to the oxidea t high temperature. The mean of six determinations gave theatomic weight of 88.75.11 The mean of all experiments, includingsome previous debrminations,l2 is 88.7, which has been adoptedby the International Committee.Tantalum.-The determinations of the atomic weight of tan-talum up to the present have not given satisfactory agreements,and a new determination has bebn made from the1 ratios2TaCl,:Ta20, and TaC1,:5Ag.The results of the latter ratio gavevalues of the atomic weight between 180.90 and 181.36.13 Thesilver chloride was precipitated in thel presence of 5.5 per cent.hydrofluoric acid. I n view of the somewhat large divergencesbetween the atomic-weight values the investigation is to becontinued.Cadm.ium.-It was found that cadmium can be purified by therecrystallisation of cadmium bromide. The method adopted for thedetermination of the atomic weight was the electxolysis of cadmiumchloride solutions using a mercury cathode, and the value of 112.417H.V. A. Briscoe, T., 1915,107, 63.lo C. A. von Welsbach, Nonatsh., 1913, 34, 1713; A . , 1914, ii, 130.l1 R. J. Meyer and M. Weinheber, Ber., 1913, 46, 2672; A., 1913, ii,l2 R. J. Meyer and T. Wuorinen, Zeitsch. anorg. Chem., 1913, 80, 7 ; A .l3 G. W. Sears and C. W. Balke, J . Amer. Ciiem. SOC., 1915, 37, 833; A .962.1913, ii, 323.ii, 35130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.was found.14 This is distinctly higher than the Internationalvalue, and is confirmed by the electrolysis of cadmium bromidesolutions, but the investigation is being continued. This result hasbeen criticised by Hulett and Quinn,l5 and therefore the matter isstill sub judice.MoEybdenum.-Pure molybdenum was prepared by the reduc-tion of MOO, in a stream of pure hydrogen.The atomic weight wasdetermined by conversion of molybdenum into the trioxide byheating i t in a current of air and oxygen, the value obtainedbeing 96.029.16Columbium-Sodium metacolumbate, Na20,Cb,0,,7H,0, wasprepared and then dehydrated a t 800O. The anhydrous salt washeated in a current of sulphur chloride vapour, when it was con-verted into sodium chloride. As a mean of seven determinationsthe atomic weight was found to be 93.13.17Molecular Weights.The application of Avogadro's law, which is valid for saturatedvapours, to the determinations of the volume, pressure, and tem-perature corresponding with a given weight of water vapour showsthat the molecular weight is 18.016 only a t 32O.18 As the tempera-ture rises above 32O the molecular weight continuously increases,due to the formation of H402, a t 270° the percentage of associationbeing 41.41.A t temperatures below 32O the molecular weightdiminishes owing to spontaneous ionic dissociation of the watervapour. It is found that these phenomena are functions of theconcentration and depend on Le Chatelier's law of mobile equili-brium.The general opinion that the vapours of the ammonium haloidsalts are entirely dissociated refers only to the unsaturabd vapours,for some experiments on the saturated vapours have shown thatthis dissociation is not by any means complete.19 The methodemployed was that of the static isoteniscope.20 It was found thatammonium chloride vapour between 280° and 330° is dissociatedto the extent of 67-63 per cent., the degree of dissociation decreas-14 G.P. Baxter and N. L. Hartmann, J. Amer. Chem. SOC., 1915, 37, 113 ;1 5 G. A. Hulett and E. L. Quinn, ibid., 2046; A., ii, 782.l8 J. H. Miiller, ibid., 2046; A., ii, 782.1' E. F. Smith and W. K. van Haagen, ibid., 1783 ; A., ii, 692.19 A. Smith and R. H. Lombard, J. Amer. Ghem. Soc., 1915, 37, 38; A . ,2O A. Smith and A. W. C. Menzies, ibid., 1910, 32, 1412, 1434; A., 1910,A., ii, 98.G. Oddo, Guzzettu, 1915, 45, i, 319; A., ii, 683.ii, 86.ii, 1036, 1037INORGANIC CHEMISTRY, 31ing slightly between these two temperatures. I n the case ofammonium bromide a t 320° the vapour is dissociated to the amountof 39 per cent., and a t high temperatures the percentage dissocia-tion decreases linearly to 10 per cent.a t 388O. Ammonium iodidevapour, on the other hand, is associated, especially a t low tem-peratures, but as the temperature rises the amount of associationdecreases. The last result is confirmed in a later paper, in whichare also given the densities of the saturated vapcur of phosphoruspentachloride between 90° and 1 60°.21 The saturated vapour issomewhat dissociated at 90°, and there is approximately a constantamount of 4 per cent. dissociation between l l O o and 1 6 0 O . Thelatent heat of evaporation of the pentachloride is 15,500 caloriesper molecule.Specific Heats.Certain determinations of specific heats have been made during1915 of which mention may be made.That of platinum a t hightemperatures has been determined by measuring the changes inthe temperature of an incandescent platinum filament caused bythe sudden suppression of a definite small resistance in the circuit.22The values obtained were as follows :to. cv. CP.980 1.118 1-2061178 1.116 1.2731353 1.187 1-3091440 1.213 1.3441543 1.240 1.382The values of Cu were calculated from those of C p by the Nernstand Lindemarin formula, which for platinum is :Cp = Cu[l+ 63 x 10-6(7'+ 273)].It- is interesting t o note that the specific heat rises with increase oftemperature, even a t high temperatures, which is contirary towhat would be expected.Reference was made in the report of 1913 to the determinationby Dewar of the specific heatns of the elements at very low tem-peratures.Further data are now available as regards the specificheats of copper and lead. The method adopted was as follows: Ameasured quantity of heat was developed within a block of themetal and the increase of temperature noted, the whole operationbeing carried out in a liquid hydroge'n thermostat. The followingvalues f o r their atomic heats were obtained 23 :21 A. Smith and R. H. Lombard, J. Anzer. Chem. SOC., 1915, 37, 2055;22 L. Fabaro, Nuovo Cim., 1915, [vi], 9, i, 123; A., ii, 672.23 W. H. Keesom and H. K. Onnes, Proc. K. Akad. Wetensch. Amsterdam,A., ii, 767.1915, 17, 894; A., ii, 8332 ANNUAL REPORTS ON THE PROGRESS OF' CHEMISTRY.Lend.Copper.m ,-- '______\ Atomic heat. t. abs. Atomic heat. t . abs.1.56 I 4.1 '3' 0.05 15.24"2.98 22.31 0.14 21.5055.04 46.255.67 40.86The general results agree with those calculated from Debye'sformula.Some determinations of the specific heat of ice of varyingdegrees of purity are worthy of record.24 From experiments withfour samples of ice it was found that the specific heat, s, in 20°calories a t any temperature 8 is given by s=0.5057+0-0018638-79-75 l/@, where 1 is the difference between Oo and the initialfreezing temperature of the water from which the ice was obtained.From this it may be seen that the specific heat of pure ice isgiven by s=0*5057+0*0018638. The latent heat of fusion of icein 20° calories was found t o be 79.76.I n the report f o r 1913 reference was made to some measurementsof the specific heat of helium and various diatomic gases, and theincrease in the ratio of the two specific heats obtained a t theboiling point of liquid air.Recently a, somewhat similar increasein the ratio of the two specific heats of certain gases, due t o theeffect of increase of pressure, has been published.25 The gasesinvestigated were air, carbon dioxide, sulphur dioxide, ammonia,and ethylene, The measurements were made by Behn and Geiger'smodification of Kundt's method,26 taking into account the devia-tions from the gas laws. The ratio of the two specific heats increasesin all cases with increase of pressure, and the increment increaseswith the magnitude of the deviation of the compressibilities fromthose required by Boyle's law.The following values may bequoted :cp/cv. Pressure.Air ............ 1.404 0-5 Atmosphere.1.411 3.5CO, ............ 1.288 0.5SO, ............ 1.273 0.51.307 3-671.347 2-5NH, ............ 1.297 0-51.410 3.5C,H, ............ 1.275 0-51-334 3-6724 H. C. Dickinson and N. S . Osborne, J. Washington Acad. Sci., 1915, 5,25 K. Scholer, Ann. Physik, 1914, [iv], 45, 913; A . , ii, 220.26 Ber. Deut. physikal. Ges., 1907, 5, 657; A . , 19OS, ii, 99.338; A . , ii, 412INORGANIC CHEMISTRY. 33I n last year’s Report some prominence was given to the con-troversy between Strutt on the one hand and Tiede and Domckeon the other as regards the formation of active nitrogen.Whereasthe former maintained that the presence of oxygen was unnecessaryin the production of the active gas, the latter experimenters con-cluded that they had proved that traces of oxygen were absolutelynecessary. A somewhat unsatisfactory conclusion was published ina joint paper under the names of H. B. Baker and the three authorsmentioned above. It was stated that the contradictory resultswere largely due to the difference in the apparatus used, and i twas considered probable that the production of active nitrogen isfavoured by traces of oxygen, although in a suitable apparatus theresult can be obtained even with the purest nitrogen. The writerpointed out, however, that no real explanation was given in thispaper of the non-production of active nitrogen by Tiede andDomcke, except possibly the somewhat unsatisfactory reference todifferences in the apparatus.This unsatisfactory conclusion wasfully recognised by Strutt himself, who deals with the question ina further paper.27 After Tiede and Dorncke’s visit t o this countryStrutt still felt convinced that although nitrogen could be pre-pared which gave an increased glow when oxygen was added to it,yet nitrogen containing less than 0.001 per cent. of oxygen gives avery decided glow, this nitrogen being prepared by treating com-mercial nitrogen for a long time with cold phosphorus. Sornefurther experiments, however, have now shown that i t is possibleto prepare nitrogen which gives very little glow by exposing com-mercial nitrogen for some hours t o the action of the liquid alloyof sodium and potassium a t 300O.The reduction of the glow isvery noticeable after the alloy has been heated several times withsuccessive fillings of the nitrogen. The addition of oxygen a t oncerestores the glow, the maximum effect being observed when theconcentration of oxygen is about 1/750 of the whole.An extended series of experiments has proved the fact that manyother gases act as catalysts in the formation of the glow. Methane,ethylene, acetylene, carbon monoxide, carbon dioxide, sulphurdioxide, hydrogen sulphide, chlorine, and water and mercuryvapours all cause a restoration of the glow, the most active beinghydrogen sulphide. The general conclusion thus is arrived a t thatfor the optimum formation of the afterglow a catalyst must bepresent, and that this need not be oxygen.The explanation of the27 (Hon.) R. J. Strutt, Proc. Roy. SOC., 1915, [ A ] , 91, 303; A , ii, 336.KEP.-VOL. XII. 34 ANNUAL REPORTS ON TEIE PROGRESS OF CHEMIS‘TRY.formation of the glow as being due t o an oxidising effect, in theopinion of Strutt, thus falls to the ground.Now that the controversy has reached the present stage outsidecriticism is admissible, and the writer would point out that twentyyears ago he convinced himself that it was quite possible t o obtaina specimen of nitrogen which, a t any rate in an ordinary vacuumtube, shows no trace of afterglow. This occurrence of the after-glow is familiar enough t o anyone who has worked on the spectraof the permanent gases, although its explanation was discoveredrelatively recently by Strutt.I n criticising the most recent workon the subject, the effect of the catalysts may be considered, and theconclusion seems inevitably to follow that really pure nitrogenwould give no glow a t all, even in Strutt’s apparatus. The methodof purification of the nitrogen would seem at once t o bO cumber-some and unsatisfactory. I n actual fact, the preparation of theliquid alloy of sodium and potassium free from hydrocarbons is amatter of extreme difficulty. The catalytic effect of three hydro-carbons has already been discovered, and hence i t is advisablerigidly to guard against the presence of any hydrocarbons. I nsome experiments on the thermal expansion of hydrogen underdiminished pressure, the hydrogen was prepared from its compouiidwith sodium.28 Hydrogen under atmospheric pressure was bubbledthrough liquid sodium in a glass vessel until the sodium hadabsorbed as much of the gas as possible.The temperature wasthen raised and the pressure reduced, when pure hydrogen wasevolved. It was then found necessary to repeat the operationseveral times in order to obtain the hydrogen free from hydro-carbons.Again, the complete absence of oxygen from the nitrogen doesnot seem to have been clearly established. It may savour of hyper-criticism, but it may be questioned whether the liquid alloy is asgood an absorbent for oxygen as might a t first thought beimagined. The first action of the alloy would be to dry the nitrogenand oxygen mixture absolutely, and then the fact that sodiummay be distilled unchanged in pure, dry oxygen comes to the front.The easiest, way to prepare small quantities of pure, dry nitrogenis to use the method described by Ramsay and Travers in theirwork on the rare gases,”g namely, to place a small pellet of phos-phorus in a fairly strong tube full of mercury and inverted overmercury.The top of the tube is warmed with a Bunsen flame28 E. C. C. Baly and (Sir) W. Ramsay, Phil. Mug., 1894, [v], 38, 301;29 (Sir) W. Ramsay and M. W. Travers, Proc. Roy. SOC., 1901, 67, 329;A., 1895, ii, 38.A , 1901, ii, 237iiiztil the pellet of phosphorus melts. Air, previously freed fromcarbon dioxide, is then driven into the tube by a capillary.Thepllosphorus inflames a t once, care being taken to admit the airsufficiently rapidly to cause vigorous combustion. Nitrogen SOmade does not seem t o give any glow whatever.Further, no evidence is forthcoming in Strutt’s paper that anyone of the catalysts he used was free from contamination by oxygen.F o r example, the preparation of carbon monoxide free from admix-ture with oxygen is exceedingly difficult, the only test for theabsence of oxygen being that i t gives the Swan spectrum whenexamined a t low pressure.Again, the evidence afforded by the oxygen containing catalystsis indecisive, since all four, carbon monoxide, carbon dioxide,sulphur dioxide, and water vapour tend to decompose into theirelements when subjected under diminished pressure to the electricdischarge.The one possible exception is mercury vapour, whichdoes seem of itself alone able to restore the glow in nitrogen. Itmust not be forgotten, however, that mercury always contains con-siderable amounts of oxides dissolved in it, and the removal ofthese is abnormally difficult. Even when the mercury has beendistilled in a vacuum it is still contaminated, as may be seen atonce when it is shaken with pure water in a stoppered bottle.Possibly these oxides may have been decomposed completely in therepeated heating which Strutt applied, although this is question-able.Finally, Strutt’s claim that pure nitrogen can be prepared bythe action of cold phosphorus on commercial nitrogen is not verysound.Ozone and low oxides of phosphorus are always formed,and the latter are by no means easily removed. Their presence inthe nitrogen when the discharge is passed might produce sufficientoxygen t o give rise to the glow.Some further results on the production of helium and neon invacuum tubes during the passage of the electrical discharge maybe noted.30 The work of Collie, Patterson, and Masson was fullydealt with in last year’s Report. The new results are entIirelynegative. The electric discharge was passed with three differentsize coils, three different types of interrupters, through varioussized and shaped tubes with palladium, platinum, and aluminiumelectrodes of various shapes and sizes. The analyses of the residualgases were carried out by phosphorus and charcoal in various ways,but no change of the gases, such as the production of helium orneon, was detected.A theoretical discussion shows that it would seem to be impossible30 A.C. G. Egerton, Proc. Roy. SOC., 1915, [ A ] , 91, 180; A , , ii, 132.c 36 ANNUAL REPORTS ON THE PROGRESS OF' CHEMISTRY.for helium t o be produced by the association of hydrogen atoms ormolecules together. First of all, the probability is dealt with thathelium can be produced by a fourfold collision of hydrogen atoms,and it is shown that there would have t o be a t least 7.7 x 108 suchcollisions per second in order t o produce a detectable quantity ofhelium in ten hours. I n the second place, the possibility that thehelium might be produced by the collision of a cathode particlewith two molecules of hydrogen, and it is shown that the probabilityis that only one helium atom would be produced in aboutyears.On the other hand, it would seem possible that the heliummay be formed by the disintegration of the metallic electrodes orof the oxygen, silica, and other constituents of the glass or gases inthe discharge tube.Allotropy.I n the section of last year's Report dealing with this subjectreference was made t o the fact that copper, cadmium, and zinc hadbeen added t o the list of metals which exhibit allotropy. Thework in this field has during this year considerably been extended.Further experiments on bismuth 31 have shown that the transitiontemperature between the a- and P-modifications of this metal, a tfirst considered t o be 7 5 O , depends on the previous history ofthe meta1.32 Finely divided bismuth which has been in contactwith a 10 per cent.solution of potassium chloride for twelve hoursdiminishes in volume a t 70°, whereas the same sample of the metalbefore treatment shows an increase in volume between 7 5 O andlooo.Pure lead, con-taining not more than 0.001 per cent. of copper and 0.0006 percent. of iron, has D:' 11.3299. After immersion for some days ina 40 per cent. solution of lead acetate containing 100 C.C. of nitricacid (D 1.16) in a litre, the lead undergoes a marked change inappearance. No gas is evolved and the metal contracts, so that itis obvious that the change is a physical one.The density of thechanged lead as obtained at 1 5 O , 2 5 O , and 50° is found to be11.3415, 11.3283, and 11.3129 respectively. These results wouldseem to prove the existence of several allotropic modifications oflead. The change in the physical characteristics of the lead inAgain, it seems that lead exhibits allotropy.3331 E. Cohen, Proc. K . Akad. Wetensch. Amsterdam, 1915, 17, 1236;33 E. Cohen and A. L. T. Moesveld, Chent. Weekblad, 1913, 10, 656;33 E. Cohen and W. D. Helderman, Proc. K . Aknd. Wetensch. Amsterdam,A . , ii, 471.A , , 1913, ii, 779.1914, 17, 823; A , , ii, 58; Zeitsch. piiysikal, Chem., 1915, 89, 733; A . , ii, 457INORGANIC CHEMISTRY. 37lead acetate solution has independently been observed,34 as hasalso the change of lead when kept in lead nitrate and lead chloridesolutions. The change does not occur in acetic acid, nitric acid,or sodium acetate solutions, and therefore is due t o the presenceof lead ions.Further, the metals antimony, potassium, and sodium have alsobeen found to exhibit allotropy.I n the case of antimony, theordinary form consists of two modifications with a transitiontemperature very near 1 0 1 O . If, however, the dilatometer contain-ing the powdered metal is heated for fifty minutes a t 150° beforeexamination a t 96O, a diminution in volume a t this temperatureis observed, followed by a steady increase in volume. It is con-cluded that a t 96O three allotropic modifications are present inantimony.35Potassium consists of two modifications with a transitiontemperature of 59.6-59-B0, the ordinary forin being a metastablemixture of both modifications.3GSodium also exists in two modifications, the P-form being lessdense than the a-forin.379 38 The change 8- a takes place mostrapidly a t about 9 5 O .Since under the same conditions liquidsodium is formed more rapidly from the &form than from thea-form, i t appears that the change P-+ a is exothermic.39Some further work may also be recorded on the allotropy ofsulphur.40 The preparation and properties of the modification S,were described in the Report f o r 1913, and now these must be addeda fourth modification, S+,. Concentrated hydrochloric acid a t Oois added t o a cold solution of sodium thiosulphate, and the aqueoussolution is then shaken with toluene.After a short time S,separates from the toluene as orangeyellow crystals. There islittle doubt that SA, S,, S,, and S, represent four different mole-cular complexes with definite and distinct properties. It isbelieved that S,, is S,, S,,+, is S,, and that S, is Si. The solutionsof S+ are less strongly coloured than those of S,, and the differ-ence between the two forms is definitely proved by their solubili-34 H. Heller, Zeitsch. physilial. Chetri., 1915, 89, 761 ; A . , ii, 674.35 E. Cohen and J. C. van den Bosch, Proc. K. Akud. Wetensch. Aiiisterdtrut,36 E. Cohen and S. Wolff, Proc. K . Akad. Amsterdam, 1915, 17, 1115 : A ,37 E. Cohen and G. de Bruin, ibid., 1916, 17, 996; A . , i i , 83.E. Cohen a i d S.Wolff, ibid., 1916, 18, 92; A . , i i , 634.3g For R general ilccouiit of Professor C‘olien’s work sw 13. (‘olien niitlW. D. Helderman, Proc. K. rlknrl. Wetemch. A)nsterdunz,, 1915, 17, 1238;A . , i i , 417; and E. Cohen, Truns. Puruduy Soc., 1915, 10, 216; A . , ii, 565.4o A. H. W. Aten, Zeitsch. physikal. Clzem., 1914, 88, 321 ; A . , ii, 254.1914, 17, 645; A . , ii, 58; Zeitsch. physikal. Chew., 1915. 89, 757; A . , ii, 471.ii, 25838 ANNUSL REPORTS ON THE PROGRESS OF CHEMISTRY.ties. Some difficulty was found in the experimental work owingto the existence of two forms of S,, the ordinary insoluble formand an unstable liquid form which is soluble. The difficulty layin proving that a solution of S, or S+ is not z solution of S,.Itmay be stated, however, that the experimental evidence is clearlyin favour of S, and S, and S, being three separate and distinctmodifications of sulphur.It may perhaps be mentioned here that a new crystalhe varietyof silver has been prepared.41 Spongy silver is first made byigniting in a crucible pure and dry precipitated silver tartrate.Nitric acid (D 1-42), from which the lower oxides of nitrogen havebeen removed by boiling with carbamide, is allowed t o act on thespongy silver a t the ordinary temperature. A t first some actiontakes place, with the formation of silver nitrate and nitrous acid,but after a time the solution of silver ceases, and on allowing themixture t o remain, with occasional shaking, for about a fortnight,the remaining silver is converted into long, needle-shaped crystals.This is considered t o be a new variety of crystalline silver belong-ing t o the cubical system.Bale n,c y .I n the Annual Report for 1913 a brief account was given of thework carried out by Ephraim on the ammine derivatives ofbivalent metals, the object of this series of investigations being t ocompare the secondary valencies of the metals in these compounds.Since the publication of t h a t report this work has been carriedconsiderably further, especially in connexion with the secondaryvalencies of the central atoms in complex anions.I n order t ocompare the stability of complex anions with that of complexcations, a considerable number of acid chlorides of organic baseshaving the general formula M[CI(HCl)] were prepared, and thedissociation pressure of the hydrogen chloride a t various tempera-tures was determined.42 It was found that the dissociationtemperature for a given pressure varies very little for the majorityof acid salts of the tertiary amines.The relation between theatomic voIume and the secondary valeiicy of the bivalent metalshas further been investigated by a study of the ammines of thechlorates, bromates, and iodates of the metal~.~3 It was found,however, that in the two former series of compounds the dissocia-tion curves are limited by the explosive nature of the compounds.I n the case of the iodates, the dissociation occurs at relatively low4 1 T. C'. Choudhri, J . Amer. Chsm. Soc., 191 5,37.PO37 ; di., ii, iG8.42 F, Ephraim, Ber., 1014, 47, 1828; A . , 1914, i, 827.43 F. Ephraim and A. Jahnsen, ibid., 1815, 48, 41; A., ii, 166ISORGANIC CHEMISTRY. 39temperatures. It seems definitely found once more that theconstant product v v . $T, where u is the atomic volume and T theabsolute dissociation temperature for a given pressure, is slightlyhigh for nickel and decidedly so for cadmium. It is probable thatthese discrepancies are due to an alteration in the atomic volumewhen the combination with ammonia takes place, and it may bepointed out that this view is supported by a comparison of themolecular volumes of the compounds.I n general, i t is found that those factors which increase thestability of the molecules with complex cations, notably the small-ness of the central atoms, work in exactly the opposite directionin the case of complex anions.44 Thus the salts of complex metallo-hexammine cations decrease in stability with the atomic volume ofthe metal, whilst the hydroxides, carbonates, nitrates, sulphates,and peroxides of the alkaline earth metals, M[O(H,O)], M[O(CO,)],M[O(N,05)], M[O(SO,)], M[O(O)], increase in stability.The effectof the atomic volume of the central atom in the cation is verydefinite, but that of the atomic volume of the central atom in theanion is doubtful. It follows from this that the stability of theammines, M(NH,),X,, depends not only upon the metal, but alsoon the central atom of the ani0n.~5 The influence of these twooppose one another.The stability of the molecule as a whole,therefore, is the result of two influences, and consequently theremay be found no direct parallelism between analogous compounds.F o r example, the hexammine and pentammine swim of nickeland zinc with the same acid radicles are not analogous to oneanother. An independent measurement of the affinity forammonia in the hexammines of nickel and cobalt has shown thatthis increases in the order chloride, bromide, iodide,*6 but in thecase of the monoammines i t would seem that the reverse is thecase.- -Some measurements of the physical constants of hydrogen andthe halogen hydrides have been made. The density of liquidhydrogen, determined by the displacement method, was found t obe 0.07105 a t -252.83O and 745.52 111111.47 I n the case of thehalogen hydrides, the following values were found for the meltingpoints and boiling points: hydrogen chloride, m.p. -111*4O, b. p.45 F. Ephraim, Ber., 1916, 4.8, 624; A . , ii, 441.45 F. Ephraim and E. Boller, ibicl., 638; A . , ii, 464.4F W. Riltz and B. Fdkenhauer, Zpitsch. aizorq. Che???., 1914, 89, 134; A . ,47 8. Augustin, Ann. Physik, 1915, [iv], 46, 419; A., ii, 117,ii, 46640 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTHY.-83'4O; hydrogen bromide, m. p. -88*1O, b. p. - 6 7 * l 0 ; hydrogeniodide, m. p. -50*9O, b. p. -35.5°.48Mention may also be made of the melting points of the metalslithium, sodium, and potassium, which have been redeterminedwith great accuracy, and are now recorded as 180'1°, 97*6O, and62.04O respectively.49I n connexion with the alkali metals, careful search has beenmade for an alkali element of higher atomic weight than czsiuiii.-j"Rather more than 3.5 kilos.of caesium nitratel was prepared frompollucite, and the whole of this was subjected t o a prolongedfractional crystallisation, since it seemed likely from the solubilitiesof the nitrates of the alkali metals that the nitrate of any alkalimetal of higher atomic weight than czesium would be the leastsoluble of all. After eighteen series of crystallisations, the leastsoluble fraction, which contained about 3 grams of czsium nitrate,was carefully examined. The spectrum of this fraction showed nodifference from that of one of the intermediate fractions, nor didthis least soluble fraction show any sign of radioactivity.Finally, the atomic weight of the metal in the least solublefraction was determined by the analysis of the chloride.Theaverage result of the determinations gave the value 132.82, whichagrees closely with that adopted by the International Committee,namely, 132.81. It is clear that these experiments give no indica-tion of the existence of an unknown alkali element.Reference was made in the Report for 1912 to the preparationof a chemically active form of hydrogen by heating metallic fila-ments of tungsten, palladium, or platinum t o high temperaturesin hydrogen a t very low pressures.sl The hydrogen appears t odissolve in the metals as atoms, and these atoms diffuse out andhave little opportunity of joining together again t o form molecules.The losses of heat from tungsten wires have been measured inhydrogen a t pressures from 0.01 mm.up t o ordinary atmosphericpressure,52 and the results of these experiments have now beenapplied t o the calculation of the degree of dissociation and theheat of formation of molecular hydr0gen.5~ A large) amount ofchemical evidence has also been accumulated. I f hydrogen a t lowpressures comes into contact with metallic wires a t temperaturesabove 1300O abs., part of the hydrogen is converted into an active48 0. Maas and D. McIntosh, Trans. Roy. SOC., Canada, 1914, [iij], 8, 65;49 A. Bernini and C . Cantoni, Nuovo Cim., 1914, [vi], 8, ii, 241; A . , i i , 82.50 G . P. Raxter, J .Amer. Chem. SOC., 1915, 37, 28G; &4.. i i , 97.61 I. Langmuir, ibid., 1913, 34, 1310; -4., 1912, ii, 1162.62 I. Langmuir and G. M. ,J. Mackay, ihid., 1914, 36, 1708; &4., 1914, ii, 717.63 I. Langmuir, ibid., 1916, 37, 417; A , , ii, 249.A . , ii, 314INORGANIC CHEMISTRT. 41inodificatiou which remains adsorbed on glass surf aces for longperiods of time. This active hydrogen can react a t room tem-perature with oxygen or with many reducible substances, or candissolve in metals such as platinum. There are good reasons forthinking that this active hydrogen is hydrogen in the atomic con-dition. A new series of experiments was made in order to measuremore accurately than before the) heat losses from a tungsten wirea t temperatures from 8006 to 3500O abs.and a t pressures ofhydrogen ranging from 0.01 mm. up to atmospheric pressure.Similar experiments were made with nitrogen.A t temperatures below that a t which dissociation occurs theheat loss from the wires decreases steadily as the pressure isdecreased. Only a t pressures above 200 inm. do convectioncurrents play any important part. The normal heat conductivityis easily separated from the abnormal effect due t o dissociationof the’hydrogen. With nitrogen there is no abnormal increase inthe heatl loss a t high temperatures.The dissociation of the hydrogen does notq occur in the spacearound the wire, nor by the impact of molecules against its surface,but takes place only among the hydrogen molecules which havebeen absorbed (dissolved?) by the metal of the wire.Within themetal the reaction occurs so rapidly that, equilibrium may beassumed to prevail a t all t,imes. The equilibrium constant withinthe metal may, however, be very different from that in the gasp h jlse .It is assumed that there is no “adsorption film ” on the surfaceof the wire through which the hydrogen has to diffuse, but thatthe3 absorption takes place by the collision of the molecules (oratoms) against the surface of the wire. A certain proportion ofthe molecules striking the surface may be reflected without’ absor6-tion. Thus, of all the hydrogen molecules striking against thesurface, i t may be assumed that a certain fraction a2 is absorbed,whilst the fraction 1-az is reflected. Similarly, of all thehydrogen atoms striking the surface, the fraction a, is ahorbed.I n general, ths partial pressures of atomic hydrogen in the gasimmediately surrounding the wire will not be that correspondingwith the equilibrium a t the temperature of the wire.The partialpressure of atomic hydrogen immediately around the wire dependson, first, the rate a t which atomic hydrogen escapes from the wire;secondly, the rate a t which atomic hydrogen is absorbed by thewire; and thirdly, the ratel a t which it can diffuse’ away from thewire.It has been found possible by thermodynamical reasoning todevelop a quantitative theory by which the dissociation constantc42 ANNUAL REPORTS ON TRE PROGRESS OF CHEMIS‘I‘RY.X (in the gas phase) may be calculated in terms of W the heatcarried from the filament by dissociation, q the heat of reaction,2) the diffusion-coefficient, and the two coefficients o1 and a2.Theresulting general equation is of the form :where P is the total pressure. By comparing this equation with theexperimental data, i t is found possible so to choose the quantitiesI%, q, D, a,, and a2 that the resulting equation agrees excellentlyNith the experiments a t all temperatures and pressures. At thesame time the values of K conform t o the thermodynamical require-ment given by van’t fioff’s equation, dl n K / d T = p/RT2.The values of the quantities 11, q, D, nl, and a2 which were usedin these calculations, and found t o give the best agreement betweenexperiment and theory, are as follows :Dissociation, Coxstaiit X.-The dissociation constant is defined byZhe equation- K=p12!p2, p1 and p2 being the partial pressures (inmm.) of atomic and molecular hydrogen respectively.It is foundthat log,o K = 7-77 - 19700/ !Z’, whence i t is calculated that thedegree of dissociation a t 760 mni. is 0.0033 a t 2000°, 0.014 a t2300°, 0.031 a t 2500°, 0.17 at 3100°, and 0.34 at 3500O abs.H e a t of 1~’ormcttion of Hydrogen iVolec&s.-By applying van’t‘IIoff’s equation i t is found that the heat of reaction for 2 gramsof hydrogen is 84,000 calories at constant volume and 90,000calories a t constant pressure.Diffzcsio,z-coefficie~it of A toniic Hydrogeu i i t Mdecular Hydrogen.-This quantity is found t o be 0=2.14.10-3 2‘.This result is4.2 times greater than that found previously (Zoc. cit.) by calcula-tion from tlis principles of the kinetic theory. This differencesuggests that the hydrogen molecules are more or less “trans-parent ” to hydrogen atoms. The effect is probably quite analogoust o that of the abnormal mobility of the hydrogen and hydroxylions in aqueous solutions.T h e Coeficiettts a1 and a,.-The coefficient a, is found to beconstant and equal to unity, whilst a2 is apparently constant andequal to 0.68. I n other words, all the hydrogen atoms strikingthe filament are absorbed by it, and 68 per cent. of all the hydrogenmolecules are absorbed. The velocity of the reaction is thus deter-mined, practically entirely, by the equilibrium conditions withinthe wire.The rate a t which hydrogen a t very low pressures is dissociatedby a tungsten wire a t 1200-1500O has been calculated, and foundto be eight to ten times greater than the greatest observed rate a tK= [( TV/ q)“P/D + 1 /.1)2]/[P - ( n / ./ q ) ( P / D + 1 /a*)],which active hydrogen is deposited on glass surfaces. I n view ofthe marked fatigue effects characteristic of this adsorption of activINORGANIC CHEMISTRY. 43hydrogen by glass, the agreement is close enough t o lend furthersupport t o the theory. The quantitative evidence of the dissociationof hydrogen may therefore be said to extend over a temperaturerange from 13@Oo to 3500O abs., in which the degree of dissociationincreases in the ratio 1 :70000.Experiments from the heat losses from tungsten wires in mixturesof nitrogen and hydrogen also yield results in accord with thetheory.The diff usion-coefficient of hydrogen atoms through nitro-gen is found to be D=2*5(T/273), which is in excellent agreementwith the value calculated from the kinetic theory.It is a well known fact that the addition of sulphuric acid insufficient quantity t o the saturated solution of a hydrated saltwith which the acid does not react, will cause the salt t o crystallise,either as a lower hydrate or in the anhydrous condition. It ispossible in certain cases to use this means of preparing lowerhydrates in order to determine all the stable hydrates which anormal sulpkate can form a t a given temperature. The methodhas been av-nlied t o the determination of the hydrates of coppersulphate a t 2 5 O , and the results have been plotted as a curveshowing the range of conditions under wliicli each of the threehydrates, CiiS0,,5H,O, CuS0,,3H20, and CuSO,,H,O, is €ormed.MThe conditions for the trihydrate are very narrow; the penta-hydrate has the widest range, being stable in contact with solutionscontaining as much as 49 per cent.of sulphuric acid.Very few cuprous salts of oxygen acids are known, and i t issoinetimes erroneously stated that such compounds do not exist.Two new cuprous salts have been prepared, namely, cuprousoxalate 55 and cuprous carbonate.56 The best known member ofthis class of compounds is red cuprous sulphite, Cu,SO,,H,O. Aconcentrated solution of sodium hydrogen sulphite is added t o asolution of cupric sulphate, the slight precipitate is filtered off,and the filtrate is gently warmed.Sulphur dioxide is evolved andthe red salt crystallises out. This is sprinkled little by little intoa hot solution of an excess of oxalic acid. Much sulphur dioxideis evolved and the colour of the solid changes from bright red tobrown. The precipitate is collected, washed with water, andfinally with alcohol. Analysis shows that the salt is cuprousoxalate, Cu2C,0,,2H,O. When the salt is heated a t about 9 5 O fortwo hours the colour changes to dark grey. When heated alonein a crucible the substance changes to grey and then to greenish-grey, giving off traces of water, and finally undergoes violentG * L.C. Daniels, J . Amer. Chem. SOC., 1915,37, 1167; A . , i, 493.5; P. Carles, Bull. SOC. chim., 1915, [iv], 17, 163; A., ii, 459.56 3. W. Foote, J . Amer. Chem. SOC., 1916, 37, 258; A., ii, 97.c* 44 ANNUAL REPORTS ON THE PROGRESS OF CHEMIS’I‘RT.tleconiposition. The grey substance has the same compositioii asthe original brown compound.When metallic copper is exposed to the action of air and liquidammonia i t becomes coated after a time with copper carbonate andthe action ceases. Jt7hen the copper thus coated is left in contactwith the ammonia the blue colour of the surface changes t o greenand then slowly to reddish-yellow, which is permanent. Thematerial may be detached by boiling water, and is cuprous carbonateproduced by the reducing action of the copper.Mention may also be made of two new sodium borates contain-ing more boron trioxide than ordinary borax, namely, Na,0,3B,03and Na20,4B20,, which melt a t 694O and 783O respectively, whilstordinary borax qelts at. 730O.57Group 11.A new determination has been made of the critical temperatureof mercury.The mercury was heated in sealed quartz tubes, andthe changes in the volume of liquid and vapour phases observedup to 1400°.5* In order to obtain the density of the saturatedvapour a t high temperatures, similar tubes were heated, and thetemperature a t which the liquid just disappeared was determined.From the data obtained i t was found that the critical temperaturemust be lower than 1650O. It is, however, higher than 1500°, f o rin one experimetit the temperature was raised to this value andliquid mercury was still present.Some investigations have been made of the effect of small pro-portions of salts of certain organic bases and also of gelatin on theelectrolytic deposition of zinc from a solution containing zinc andammonium sulphates, a pure zinc anode and a brass cathode being~ised.59 When very small amounts of these substances are presentand when the current density is low, a homogeneous, uniform, fine-grain deposit is obtained, but if either the proportion of the addedcompound o r the current density is increased the zinc then sepa-rates irregularly in nodular masses.It is invariably noticed thatthe first uniform deposit oiily dissolves slowly in hydrochloric acid.It is suggest.ed that the organic substance present in the1 neigh-bourhood of the cathode is absorbed by the1 metallic granules whichseparate initially in a state of high dispersion, and so renders thedepcsit fine-grained.At a later stage the organic compound tendsto coat the cathode with a morel or less impermeable varnish, and57 J. Bonomarev, Zeitsch. anorg. Chem., 1914, 89, 353 ; A ., ii, 449.58 J. Bender, Physikal. Zeitsch., 1915, 16, 246; A . , ii, 673.59 A. Mazzucchelli, Atti R. Accad. Lincei, 1914, [v], 23, ii, 503, 626; A . , ii,670, 671INORGANIC CHEMISTRY. 45thus induces passivity. At certain points of the cathode whichare accidentally favoured, deposition may continue a t an increasedcurrent density, tliei crystalline, nodular masses being thus formed.So f a r as they have progressed, tlie experiments indicate that thecathodic deposition of tlie zinc is influenced more than the anodicdissolution.Some interest attaches to an investigation of the displacementby zinc of certain metals from solutions of their salts.60 I n thecase of copper salts a zinc ,plate, attached by means of wax t o aglass stirrer, was kept in continual motion in a solution of coppersulphate of definite initial concentration, and tlie alteration in thelatter was determined a t regular intervals by titration withN / 100-sodium thiosulphate solution.Experiments were made withAT/ 100- and S, 20-copper sulphate solution a t the ordinary teni-perature and a t 25", the surface of tlie zinc being polished inevery case.The results obtained show that the velocity-constantof the reaction increases during the' first half hour, but that thereis no sharply defined period of induction. The reaction follows tlieequation of the first degree, a s is required by the theory of diffu-sion, so that its velocity is proportional t o the first power of theconcentratioii of tlie copper sulphate.I n order t'o determine the lapse of time between the immersionof the zinc and the commencement of the deposition a t its surfaceof the other metal, some further experiments have been made withsolutions of copper sulphate and of nickel and cobalt chlorides,sulphates, and nitrates. The zinc cylinders used were coated withwax, except, over one end-surface, which was polished and arrangeduppermost in the liquid in order to admit of examination under alens. Zinc reacts with copper salts far more readily than withthose of nickel and co'balt, and in solutJons of chlorides the actionbegins decidedly earlier than in solutions of the correspondingsulphates.With nickel and cobalt nitrates no action occurs,although in a concentrated solution of the former a precipitateof the hydroxide gradually appears. In solutions of coppersulphate the reaction does not give rise t o the liberation of gas,but in nickel chloride and sulphate solutions the deposition of themetal is followed some time later, and in cobalt chloride, veryconsiderably later, by the evolution of gas bubbles. The1 gas isprobably hydrogen, resulting from the decomposition of the waterby the zinc-nickel or zinc-cobalt couple.The deposition of the1metal is not influenced by tlie presence of NO, ioiis, and twoeciiiivalent solutions containing (1) nickel siilpliate and potassiu 1116O M. Centnerszwer and J. Drulrker, J . Russ. PAYS. C'he,rz. Soc., 1915, 47,528 ; A., ii, 56346 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.nitrate, and (2) nickel nitrate and potassium sulphate gaveidentical results.It is concluded that a period of induction exists, not only inthe displacement of hydrogen, but also in that of metals by zinc.I n the latter case, however, this period of induction is far shorterthan in the former, and is noticeable only with very dilute solu-tions of the salts.The retardation, therefore, of the dissolution ofzinc in acids during its initial period must be due to the difficultywith which the hydrogen ions are converted into gaseous hydrogen,and to the resistance offered by the dielectric layer formed by thedischarge of the hydrogen ions at the surface of the electrode.I n the displacement of metals by zinc, “local elements” areformed very shortdy after the initial deposition of the metal on thezinc, the velocity of the reaction being proportional t o the sumof the currents of all these cells. Since the resistances of thelatter are small, the, electrochemical interchange of metals proceedswith great rapidity, and the velocity of the reaction is conditionedsolely by the rate of diffusion of the dissolved salt from the solutionto the surface of the zinc; in this phase, therefore, the reactionfollows the theory of diffusion.I n the displacement of hydrogen by metals the bubbles ofhydrogen pass away from the surface of the metal, and the causeof the establishment of local cells is thus absent.Such localgalvanic elements may, however, be formed in this case (1) inconsequence of the presence of admixed metals, and (2) owing tosolution of hydrogen in the zinc. Since both of these causes act veryslowly, the period of induction is greatly prolonged in this case.Some work may be recorded on the peroxides of the alkalineearth metals and of zinc.61 When hydrogen peroxide is added t obarium hydroxide solution the octahydrate, Ba0,,8H20, is alwaysobtained when more than one’ molecule of barium hydroxide ispresent per molecule of hydrogen dioxide.Above 60° i t is formed,whatever the composition of the solution. The anhydrous per-oxide cannot be1 obtained from aqueous solution. Below 40° thediperoxyhydrate, Ba0,,2H20,, is obtained from solutions contain-ing much hydrogen peroxide. A compound, BaO,,H,O,, may alsobe obtained between 30° and 60°.Anhydrous strontium peroxide is obtained from very concen-trated solutions above 50°, otherwise the octahydrate is formed.The diperoxyhydrate is n o t obtained by direct precipitation, buhmly by the action of concentrated hydrogen peroxide on the octa-hydrate a t low temperatures.405; 90, 150; A., ii, 449, 454.61 E. H. Riesenfeld and W.Nottebohm, Zeitsch. anorg. Chem., 1914, 89INORGANIC CHEMIS'1'RY. 47Calcium peroxide separates in the anhydrous form from veryconcentrated solutions near Oo, and above 40° even from verydiIute solution. The octahydrate is obtained from dilute solutionsa t the ordinary temperature. A dihydrate may be prepared fromthe anhydrous compound. The diperoxyhydrate resembles that ofstrontium. By the action of water, all these compounds are slowlyconverted into the octahydrates.If hydrogen peroxide is added t o an ammoniacal solution of zincnitrate a t -5O, a white, amorphous precipitate is obtained which,after being dried, gives the ratio ZnO : active oxygen : water =1 : 0.84 : 0.71. If the powder is stirred with concentrated hydrogenperoxide, this ratio may be increased to 1 : 0.91 : 0.87, which indi-cates the presence of zinc peroxide, ZnO,.The lime-sulphur wash, which is used extensively as a fungicide,is prepared by boiling together one part of quicklime, two or moreparts of sulphur, and ten parts of water.62 The concentrated com-mercial product generally contains the polysulphides, thiosulphate,sulphite, and sulphate of calcium, the polysulphides and the thio-sulphate preponderating.There is no doubt that much of thesulphur in the lime-sulphur solution is in a very loosely combinedcondition, for some early experimeiits showed that i t was possiblet o extract it with sulphur solvents. Some objection arose to theseexperiments on account of the non-exclusion of oxygen and carbondioxide.Extractioii of the fluid with sulphur solvents causes a continuousremoval of free sulphur.This continuous formation of sulphur isdue to the hydrolytic dissociation of the polysulphides, whichaccounts also for the strongly alkaline nature of the solution.Since also hydrogen sulphide is readily liberateid in quantity whenthe liquid is heated, the formation of the sulphur is probably dueto the following equilibria :CaS + 2H,O Ca(OH):! + H,S,,HZS, HZS + (X - 1)s.Attempts were made t o detect the existence of a more stablepolysulphide in solution by measuring the sulphur removed a tstated intervals, and although, by themselves, the results cannotbe regarded as conclusive, owing to experimental difficulties, yet itis significant that a lower rate of extraction sets in when the ratiobetweeii the polysulpliide sulphur (S,) plus inonosulphide, sulphur(S,) and the monosulphide sulphur alone is between 1.6 and 2.3.Attempts were made to prepare calcium disulphide by boilingtogether lime and sulphur in the calculated proportions, but inS .J. R.I. Auld, T., 1915, 107, 480; A , , ii, 3448 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.every case Herschell’s crystals were obtained. The analytical resultsshow that the main product in these crystals corresponds with theformula Ca0,CaS2,7H,0.It is concluded that in the absence of air, lime and sulphur reactin aqueous solution, with the formation only of calcium poly-sulphides (or oxysulphides) and calcium thiosulphate. When anexcess of sulphur is used, the ratio of (S, + S p ) / S 1 ) L usually liesbetween 4.5 and 5.0, but may exceed the latter figure under certainconditions.The formation of the polysulphides from lime and sulphur mayprobably be expressed by the equations5Ca(OH), + 6s = ZCaS2,Ca0 + CaS,O,+ 5H,O,CaS,,CaO + ZS + H20 = CaS, +, + Ca(OH)2.By obtaining the redissolution of precipitated sulphur in the poly-sulphide solution, evidence was obtained indicating the possibleexistence of polysulphides a t least as high as CaS,.It is suggested that the polysulphides of calcium possess theconstitutionSSCa<ll>S*Y*P.. .the atoms of sulphur in the chain becoming progressively more1 o osel y attached .Group ZII.I n the last three reports accounts were given of the work carriedout by Stock an3 his co-workers on the hydrides of boron, and thepreparation and identification were described of the four com-pounds B,H,, B4Hlo, B6HI2, and BIoHl,.Some difficulty as regardsthe valency of boron towards hydrogen arises, since it would seemthat i t must be quadrivalent. An iri vestigation therefore has heenmade into the action of the halogens on these compounds, moreparticularly on B,H,, with the view of throwing some light on thequestion.63I n the first place, some improvements were made in the prepara-tion of the starting material, B,H,,. The crude gas, prepared bythe action of hydrochloric acid on the “magnesium boride,” is firstpassed through a tubs a t -40°, whereby white crystals of B10H14,1n.p.99-5O, are collected. The gas is then passed through a largeU-tubel a t -80°, and the’rein a little1 B4H10, some! silicon hydride,and chiefly B6HI2 are condensed. Finally, the main bulk of thegas is condensed by cooling with liquid air. From 100 grams ofthe boride there were obtained 0.02 grain of BloHl, and 95 C.C.(Oo and 760 niin.) of B,H,,. The B,H,, when heated a t looo63 A. Stock, E. KUSS, and 0. Priess, Ber., 1914, 47, 3115; A., ii, 340JNORGANIC CHEMISTRY. 49decomposes fairly rapidly, and the only gaseous products arehydrogen and B,H,. The B,H, from this process was condensed ina bath made by stirring liquid air into alcohol until the mass isalmost solid. I n this way a temperature of - 1 2 5 O to - 1 1 5 O maybe maintained in a Dewar vessel for some hours.The density of B,H, is found to be 13.9'7.The gas condensesin needles when cooled slowly, and a t the ordinary temperature itis not attacked by oxygen t o any extent after some days. It isdecomposed, however, a t once by traces of moisture, but i t is notacted on by hydrogen sulphide even a t looo. If the liquid issuddenly exposed t o air it inflames. The action of chlorine andbromine on the hydrides has been the subject of an exhaustivestudy. I n the case of the solid hydride, B4HI0, the reaction isvery sluggish, and it is found t h a t displacement cf the hydrogenby the halogen takes place, and not addition. When the solid isleft in a large excess of bromine for six months, the residue, afterevaporation, gives on analysis a result agreeing with a formulabetween B,,H,,Br, and B,,H,,Br,.Definite compounds seem t obe isolated by fractional crystallisation from a mixture of benzeneancl light petroleum. The alkaline solutions of these compoundsreduce permanga1iat.e solution, and then 011 acidifying yield B,H,,.The acid solutions also reduce permanganate solution and slowlyevolve B4HI0, together with other as yet unknown boron com-pounds.I n the case of B,H,, chlorine causes explosions a t the ordinarytemperature, whilst bromine reacts only very slowly even in thelight. The reaction is, however, complete after a few hours a tlooo. I n every experiment it was found that' half of the halogenused is returned as the halogen hydride, and thus it follows thatthe action is one of substitution and not addition.If the halogenis in excess, the unimolecular haloids BCI, and BBr, are formed,and not B2ClG and B,Br,. Since this fact is of great importance,an investigation was made into the intermediate stages involved inthe conversion of B,H, into the unimolecular haloid. The reactionwas studied with ail insufficient quantity of halogen, ancl the ex-planation was found in the action of bromine. When BZHG istreated with about one-third of the quantity of bromine necessaryf o r the complete reaction, the intermediate compounds B,H4Br2,etc., are not formed. The products obtained are almost exclusivelythe two extreme compounds B,H,Br and BBr,. The intermediatecompounds, although initially formed in small amounts, readilyundergo rearrangement into the two extreme compounds.Indeed,the monobromide, B2H5Br, itself decomposes into B,H, after Rshort time. The formation of hydrogen bromide was neve50 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.observed, and no evidence could be obtained of the existence ofBHBr,, BH2Br, B2H2Br4, B2HBr6, or B,Br6. The reaction withchlorine is similar, but the intermediate compounds and the mono-chloride, B2H,Cl, are f a r more volatile and labile than the corre-sponding bromine derivatives, and consequently the mechaiiisni ofthe reaction was somewhat obscured.It follows, therefore, t h a t by the action of chlorine o r bromineor an excess of B,H, the derivatives B,H,X, and B,H,X, are firstformed, and these rapidly decompose and rearrange themselvesinto B2H,X and B,H, on the one hand and BX, on the other.The monochloride, B2H5Cl, is a spontaneously inflammable gas,whilst the monobromide, B2H5Br, is a colourless gas with anirritating odour.The monobromide melts a t -104O, and thevapour pressure rises from 3 mm. a t - 8 O O t o 335 mm. a t - 5 O .The boiling point a t 760 mm. is calculated t o be loo. It burnswith a pale green flame, and fumes in the air owing to thereaction with waterB2H5Br + 3H,O =B,O, + HBr + 5H2.It reacts immediately with potassium hydroxide, like B,H6, toform the hypborate, KOBH,. No appreciable reaction takesplace when it is treated with sodium, and an attempt t o convert i tinto B,HIo failed.It is clear from these results that boron must be quadrivalent,and hence the highest negative valency must be four.The highestpositive valency is three, and hence it is evident that boron doesnot' obey the Abegg and Bodlander rule t h a t the sum of the twovalencies is eight. Some substances have been described, notablyBOCl, and B2S5, in which the positive valeiicy is supposed t o befive, but the constitution of these is very questionable.All attempts to prepare a hydride of boron with only one atomof boron in the molecule have failed. Boron trialkyls have beenprepared, but they are as unsaturated as triphenylmethyl, whilstthe corresponding hydrides, BH, and CH,, seem to be equallyimpossible of isolation.Concomitantly with the above work, the properties of the twounimolecular haloids of boron, BCI, and BBr,, have been studied.The boron trichloride was prepared by the action of chlorine 011Moissan's boron in a glass tube, the temperature being so regu-lated that the glass was attacked as little as possible.64 The gasobtained was condensed a t - 8 O O and then shaken with mercury.It was freed from hydrogen chloride and silicon chloride by frac-tional distillation in a high vacuum from a bath a t - 7 8 O . The64 A.Stock and 0. Priess, Ber., 1914, 47, 3109; A., ii, 339INORGANIC CHEMISTRY. 51fractions were collected in a vessel cooled in liquid air, and thefirst and last fractions were rejected. The pure substance meltsa t -104O and boils a t 13O/764 mm. The vapour density is 58’43and the vapour pfessure rises from 4 mm.a t -8OO t o 753 mm. a t12.4O. The boiling point a t 760 mm. is calculated t o be 12.5O.The vapour reacts energetically with fat, and therefore a specialvalve was designed t o eliminate the use of taps in the apparatusemployed.Boron trichloride does not attack hot mercury, nor does it com-bine with chlorine even a t -8OO.Boron tribromide was prepared by passing bromine vapour overboron a t a dull red heat.65 The product was purified by shakingwith mercury, and it was then fractionally distilled under atnio-spheric pressure. The compound is a liquid with m. p. - 4 6 O andb. p. 99.1°/740 mm. The molecular weight as found by the cryo-scopic method in benzene is 252. Its vapour pressure rises from0.7 mm. a t -5OO to 730 mm.a t 90°. The vapour attacks fat asenergetically as does t h a t of the chloride.The effect of electrolysing solutions of sodium and potassiumborates with varying proportions of alkali hydroxide has beenexamined.66 No perborate is formed even when the anode isthoroughly cooled, and even very concentrated solutions only yielda minute quantity. Perborates introduced into the anode com-partment are destroyed owing t o the formation of hydrogenperoxide.Mention may be made of the preparation of pertetraboric acidand its salts. These, for example the sodium salt, Na,B,O,,, areprepared by the action of hydrogen peroxide, or a mixture witha meballic peroxide, on pyroboric acid, preferably a t below OO.67As was noted in the Report for 1912, Riesenfeld and Mau differ-entiated between the true percarbonates and the ordinarycarbonates containing hydrogen peroxide of crystallisation.Somefurther work has been published dealing with compounds whichseem to belong t o the latter class.G8 The addition of hydrogenperoxide t o the alkali metal carbonates causes the forma-tion of compounds such as CsC03,2H,0,, I~,C0,,2€~,0~,~H2O,Na,CO,,l*H,O,. These substances exhibit the properties of per-t~ ,4. Stock and E. Kuss, Ber., 1014, 47, 3113; A . , ii, 340.G6 W. G. Polack, Trans. Faraday SOC., 1915, 10, 177; A . , ii, 557.67 J. Auer, D.R.-P. 281134, J . ~S’oc. Chem. I n d . , 1915, 34, 613; A.: ii, 557.68 P. V. Cazanecki: J . Russ. Phys. Chem. SOC., 1914,443, 1110; A . , ii, 33252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.oxides, and decompose at the ordinary temperature with the evolu-tion of carbon dioxide and the formation of the correspondingmetal hydrogen carbonate as a result of the perhydrolysis of thecarbonates.Magnesium carbonate and hydrogen peroxide in solu-tion give a substance t o which is assigned the formulaMgO,,+MgCO,,H,O, but it may be pointed out that it is moreprobable from analogy t o the alkali metal compounds that theformula is MgO,;MgCO,,H2O2. All these salts react with titanicacid o r chromic acid arid sulphuric acid, and they yield ozone withconcentrated sulphuric acid and chlorine with concentrated hydro-chloric acid. Since with neutral potassium iodide they evolveiodine only slowly, these compounds conform to' the test estab-lished by Riesenfeld and Mau for the carbonates containinghydrogen peroxide of crystallisation.I n the estimation of unsaturated hydrocarbons by treatment withbromine, some uncertainty arises if carbon monoxide is present inlarge amounts.This is due t o the formation of carbonyl bromide,and the conditions under which it is formed have been investi-gated.69 The extent t o which the action proceeds in sunlightdepends upon the proportion of water vapour that is present, andwhen the carbon monoxide and bromine have been carefully driedthe velocity of reaction is very low. The reaction takes place intwo stages, CO + Br, = COBr, and COBr, + H,O = CO, + 2HBr. Inthe first stage, equilibrium is reached with a small concentrationof the carbonyl bromide, which must be removed as i t is formedin order that the reaction may continue.Some information has been obtained as to the nature of thechanges which occur during the extraction of metallic lead fromgalena by the roasting process. The equilibrium conditions in thesystem lead-sulphur-oxygen have been investigated by the deter-mination of the dissociation pressures between 500° and 800° andexamination of the solid phases present under varying conditionsof temperature and pressure70When sulphur dioxide is removed froin a mixture of leadsulphide and lead sulphate, five successive univariant systems withthree solid phases can be recognised : (1) PbS-PbS0,-PbO,PbSO, ;(2) 'Pb-PbS-PbO,PbSO, ; (3) Pb-PbO,PbSO,-2PbO,PbSO, ;(4) Pb-2PbO,PbSO,-3PbO,PbSO, ; (5) Pb-SPbO,PbSO,-PbO.From the vapour-pressure curve for the first system i t is foundthat the thermal value of the reaction PhS + PhSO, = 2Ph+ 2S0, is- 99,543 caloriesINORGANIC CHEMISTRY 53111 the 1tel)orL for 1913 reference was niacle t o work 011 the pro-duction and properties of red lead.An investigation of the dis-sociation pressures of the higher oxides of lead may now berecorded.71 The oxide was heated a t various temperatures, whichwere kept constant within 0.2 per cent. by an ingenious electricaldevice in cmnexion with a manometer, pump, and oxygenreservoir. Red lead, purified by repeated heating with lead nitrateo r acet'ate solution, reaches equilibrium only very slowly when dis-sociating.The pressure-temperature curve between 445O and 607'is quite smooth, and there is no evidence of a solid solution ofthe monoxide, PbO, in red lead, Pb,O,, or of any intermediateoxide. The monoxide thus prepared is yellow, with a greenshade when obtained a t high temperatures. The same pressuresare obtained in the reverse process, namely, when oxygen isadmitted t o lead monoxide which has been prepared from thedecomposition of red lead in a vacuum. The red modification ofthe monoxide prepared in the wet way only absorbs oxygen veryslowly a t 540°, and retains its colour. The reactivity varies withthe mode of preparation.The dissociation of lead peroxide gives unstable products downt o PbO,.,, a t 3 6 1 O . Red lead is not formed, but the products aresolid solutions of varying compositions, unstable in regard to redlead.The limit is reached a t PbOl.,G, beyond which lithargeappears a t a new phase. The formation of definite oxides, suchas Pb,O,, Pb,07, or Pb,O,, has not been confirmed.A systematic study has been made of the plumbichlorides, whichare prepared by mixing solutions of the acid, H,PbCl,, with solu-tions of the chlorides of the metals o r bases.72 The compoundsare anhydrous and have the general formula X,PbCl, or(R*NH,),PbCl,. I n those cases where the crystalline system couldbe measured, regular and rhombic forms predominate. The com-pounds of the alkali metals and of derivatives of the pyridine andquinoline series are especially stable, whilst the aliphaticammonium compounds tend t o decompose in the air, the crystalsbecoming white and chlorine being evolved.Hydrogen peroxideexerts an immediate reducing action, plumbous chloride beingseparated and gas evolved. Concentrated ammonia solution yieldsa pale brown and a dilute solution an almost black precipitatecontaining lead dioxide.Reference may also be made to two investigations of ceriumcompounds. A double potassium perceric carbonate was describedi1 W. Reinders and L. Hamburger, Zeitsch. anorg. Chem., 1914, 89, 71;i 2 A. Gutbier and M. Wissmiiller, J . pr. Chew., 1914, [ii], 90, 491 ; A . , i, 217.A . , ii, 467541 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.by Job, and was given the formula Ce,03(C03)3,4K,C03,12H,0.7~The salt was prepared by the interaction of cerium ammoniumnitrate and hydrogen peroxide in a concentrated solution ofpotassium carbonate.The process has been modified as follows.7*A saturated solution of potassium carbonate is treated withhydrogen peroxide, and then cerous ammonium nitrate is added.The mixture is heated rapidly to 60°, and kept a t that tempera-ture as long as the colour deepens. Carbon dioxide is then passedthrough the solution until no f iwther potassium hydrogen carbonateis precipitated, and then the mixture is cooled to Oo until as muchas possible of the potassium hydrogen carbonate has crystallisedout, the passage of carbon dioxide being continued. The mixtureis filtered through glass wool and left to remain a t 5O. Thecrystals which separate are dried in the air, and on analysis arefound to have the formula Ce204(C0,)2,4K2C0,,12H20.The saltreadily loses its water of crystallisation, and then changes in colourfrom transparent ruby t o opaque orange-yellow. It is found thatof the available oxygen in the compound, two-thirds is to beregarded as peroxidic oxygen. Reference may also be made to thesimilar compound prepared by Baur, Ce,04(C0,),,4K,C0,,10H20.~~An examination of the hydrolysis of cerium sulphate has beenmade, and on the basis of the phase rule a pale yellow, basicsulphate, Ce0,,S03,2H,0, has been isolated.76 This salt issparingly soluble in water, and is hydrolysed thereby, giving anacid solution. When sulphuric acid is added t o concentrated solu-tions of ceric sulphate, it is probable that basic salts of a deepred colour are produced.When ceric sulphate, after being drieda t 1 1 5 O , is heated for thirty hours a t 1 0 5 O , it is converted into awhite compound having the formula 3Ce02,4S03. This substanceappears to exist in two modifications, which are both hydrolysedby water, but yield differently coloured, insoluble residues.When ceric sulphate or the compound 3CeO2,4S0, is heated fora prolonged period a t temperatures below red heat cerium dioxideis formed, which is pure white. The oxide becomes yellow onheating, but the colour is lost on cooling if the heating has notbeen too intense or persistent. If the white oxide is stronglyignited in a blowpipe flame it shrinks visibly in volume andbecomes slightly yellow.This change is probably due to poly-merisa tion.i3 A. Job, Compt. rend., 1899,128, 178, 1098; A., 1899, ii, 486.74 C. C. Meloche, J . Amer. Chem. SOC., 1915, 37, 2338; A., ii, 776.75 E. Baur, Zeitsch. anorg. Chem., 1902,30, 256 ; A., 1902, ii, 398.sG J. F. Spencer, T., 1915,107, 1265; A . , ii, 777I K 0 R G AN I C C H E hl. I STRS . 55Group 1'.Soiiie iiiterestiiig iiivestigations have been iuade on certainreactions with hydrazine.i7>m Pure anhydrous hydrazine is pre-pared by boiling the partly dehydrated hydrazine hydrate f o rthree hours under reflux with about a 50 per cent. excess ofbarium oxide. The liydrazine is then distilled under diminishedpressure in an atmosphere of hydrogen. The product on analysiswas found t o contain 99-7 per cent.of hydrazine. Sodium deriv-atives of hydrazine inay be prepared by the action of eithermetallic sodium or sodamide on anhydrous hydrazine. Thesesubstances are extraordinarily explosive, and from analysis appearto have the formuk NaN,H3 and Na,N,H,. The former compoundhas independently been prepared in glistening leaflets.Y9The solutions of the sodium hydrazides have been subjected toelectrolysis, for they readily conduct electricity. Nitrogen andhydrogen are simultaneously evolved a t both the anode andcathode. For each atom of copper deposited on the coulometercathode, 1.1-1.5 atoms of nitrogen ar0 liberated a t the anodewhen the' electrolytel is rather dilute. With a more highly concen-trated solution the ratio Cu: N varied from 1 : 2.1 t o 1 : 2.6.The solubilities have been determined of a considerable numberof element's and inorganic salts in anhydrous hydrazine.Of themetallic elemelits the alkali metals are the only ones that areappreciably acted on and dissolved. The solubility increases withthe atomic weight. Sulphur and iodine are very readily soluble,and chemical decomposition takes place with rapidity, especially inthe latter case. The solubility of the metallic haloids appears toincrease with the atomic weight of the halogen. I n the case of thealkaline earth metals, crystals separate from the solutions on keep-ing, which are probably hydrazinated salts. The carbonates area t most only very spaingly soluble, whilst the oxides ar0 insoluble.The nitrates, with the exception of those which react with thehydrazine, are, in the majority of cases, soluble.Sulphates andsulphides are only sparingly soluble. Ammonium salts, excepttriammoniuin phosphates, are soluble, with the evolution of muchammonia. This reaction is due t o hydrazinolysis ; bismuth chloridedissolves and reacts with the hydrazine, metallic bismuth beingquantitatively precipitated. Cadmium carbonate and sulphide aminsoluble, but the haloids are very readily soluble without anyvisible chemical reaction. The mercury salts, with the exception of77 T. W. €3. Welsh, J . Arnm. Ghem. SOC., 1915,37, 497; A., ii, 256.79 W. Schlenk and T. MTeichselfelder, Ber., 1915, p8, 669; A . , ii, 445.T. W. B.Welsh and H. J. Broderson, i b i d . , 1915,37, 816, 825; A., ii, 33756 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.mercuric sulpliide, which is insoluble, react chemically with tlieliydrazine immediately with the formation of metallic mercury.It is very probable that nickel and cobalt salts dissolve and reactchemically t o form hydrazine additive compounds. I n the caseof cobalt chloride a slow, continuous decomposition takes placewith the formation of a cobalt mirror. Copper and lead salts areall soluble with more or less decomposition, whilst in the caseof silver salts the formation of a silver mirxor is always observed.A study of the reactions which occur with hydrazine as solventhas shown that tlie following take place. Cadmium and zinc sul-phides can be precipitated by the' action of hydrazine sulphide onthose salts of these metals which are soluble in anhydroushydrazine. A zinc hydrazide is probably precipitated when sodiumhydrazide acts on a hydrazine solution of zinc chloride.Sodiumprecipitates the metals cadmium, zinc, and iron from solutions oftheir salts, but does not precipitate magnesium, calcium, andbarium. I n general, i t may be said tha.t reactions take place inanhydrous hydrazine similar t o those which occur in water, liquidammonia, and certain other dissociating solvents.A further addition has been made t o the work on the ammoniasystem of acids, bases, and salts. It has already been shown t h a tthe " ammono-acids " or acetamides react with potassamide inliquid ammonia.It is now found that salts may be obtained byusing insoluble metallic amides, imides, o r nitrides. A numberof such compounds are described, such as silver benzenesulphon-amide, S0,Ph*NHAg,2NH3, cupric benzenesulphonamide,(SO,Ph.NH),Cu, 4NH3,and potassium acetobenzylamide, CH,*CO=N(CH,Ph)K,NH,.*OWhen potassamide is added in limited amount to a liquidammonia solution of aluminium iodide a soluble ammonobasiciodide of aluminium is formed in accordance with the equationZAll, + SKNH, = Al(NH,),,AlI, + 3KI. A t the ordinary tempera-ture the salt separates with three molecules of ammonia of crystal-lisation. and a t low temperatures a highly ammonated salt separateswith 18 t o 20 molecules of ammonia. If potassamide js added t othe solution of this salt an insoluble ammonobasic aluminium iodideis precipitated, Al( NH,),, Al(NH,),I,NH,, which on heating losestwo molecules of ammonia to give Al(NH,),,AlNHI.Silver amide dissolves readily in a solution of potassamide inliquid ammonia.It is found that potassium ammonoargentate isformed. Jn accordance with the equationAgNH, + KNH, =AgNHK + NH,.80 E. C. Franklin, Proc. Nnt. Acad. Sci., 1915, 1, 68; J . -4mer. Chem. Soc.,1015, 37, 847, 852; A., i, 950; ii, 345, 348ISORGANIC CHEMISTRY. 57The compound separates from the concentrated solution in crystalswith the composition AgNHK,NH,.This work has been extended to include the reactions betweenpotassamide and salts of cadmium, nickel, and Withcadmium tliiocyanate or potassium cadmium cyanide, eithercadmium amide, Cd(NH,),, or potassium ammonocadmiate,Cd(NHK),,2NH3, is formed according as t o whether the cadmiumsalt or tlie ammono-base is in excess.The latter compound hasalready been described by Franklin. The former is a wliitepowderwhich reacts violently with water, and when suddenly heatedexplodes, with liberation of metallic cadmium. When heated a t1 8 0 O in a vacuum it loses ammonia, and is converted into cadmiumnitride, Cd,N,, a black, amorphous powder which explodes violentlywhen brought into contact with water, and deposits metalliccadmium.\Vlieii approximately equivalent amounts of potassium nickelcyanide and potaesamide are mixed, a lemon-yellow, curdy precipi-tate is formed. After a few washings with liquid ammonia thissubstance crumbles to a heavy powder having the compositionK(CN),Ni*NHK. With a large excess of potassamide a deep redsolution is formed, which on keeping yields deep red crystalshaving tlie composition Ni3N,,H,,K,(CN),.By varying the concentration of ammonia in ammonium liydr-oxide solutions of nickel thiocyanste, crystalline ammonia deriv-atives of this salt are formed with 3, 3, 4, and 53 molecules ofammonia.Under suitable conditions a fifth compound with8; molecules of ammonia is produced. A solution of nickelthiocyanate in liquid ammonia when treated with an equivalentamount of potassamide solution gives a precipitate of nickel arnide,Ni(NH,),. This substance is a red, flocculent mass which whenheated a t 1 2 0 O in a vacuum gives nickel nitride, Ni,N,.The nickelamide dissolves in an excess of a potassamide solution to give adeep red solution, which deposits red crystals of aminopotassiuinnickel amide, TU'i,N,K,,GNH,.Pure red phosphorus has been obtained by the action of phos-phorus tribromide on mercury.82 When a mixtue of these twosubstances is heated in a sealed tube a t 100-170° for several daysthe product extracted with ether, and the residue again heatedwith phosphorus tribromide, there is obtained a pure red phos-phorus as a cinnabar-red, micro-crystalline powder. The substancebecomes brownish-black a t 250°, but regains its colour on coolingand lias T)? 1 .Pi(;. It is iiisoluhle i n carbon tlisulpliide, is not81 Ci. S. Roliai-t, J .PhysicaZ C'hem., 1!)15, 19, 5:37; . 4 . , ii, 7 7 ; .R1 L. Wolf, Ber., 1916, 48, 1272; d., ii, 65458 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.blackened by ammonia, oxidises slowly in moist air, and inflamesin air a t approximately 300O.Some work on the constitution of pyrophosphoric acid and someof its metallo-derivatives may be mentioned. I n general, theproperties of this acid suggests that it possesses an unsymmetricalstru~ture.~3 The ionisation constants of the first two hydrogenions are almost identical and very near that of the first ion oforthophosphoric acid. Those of the third and fourth hydrogenions of pyrophosphoric acid are near to one another, but widelydifferent from the first. It is suggested that the most probableformuk for (I) pyrophosphoric acid and (11) orthophosphoric acidare :OH OH!! )P-OH II \ p ) H&-y /OH,‘?/&/G ‘0GH5/\\/0 0O=Y-OH : i \p-OH(1.) (11.1The facts that pyrophosphoryl chloride, P,O,Cl,, decomposes intoP O a , and P0,Cl when distilled under 19 mm. pressure, and thati t reacts more violently with water than does phosphoryl chloridesupport the unsymmetrical constitution. Sodium pyrophosphatereacts with phosphorus pentachloride in a sealed tube above 200°according to the equation :h’a,P,O, + 3PC1, = NaPO, + 3NnC1+ 4Poc1,.This reaction can only be accounted for by the unsymmetricalformula.Many insoluble metallic pyrophospha tes are soluble in alkalipyrophosphates to give solutions which fail to show many of thereactions of the metals. Several salts of complex metallo-pyrophos-phoric acids have been prepared,84 and it may be mentioned thatthey are analogous to the salts of ferriphosphoric acid.85 By drop-ping a solution of manganese sesquioxide in cold concentratedhydrochloric acid into a saturated solution of sodium pyrophos-phate, sodium manganipyrophosphate, Na(MnP20i) ,5H,O, isobtained.Potassium forms two salts, K(RlnP20,),5H,0 and 3H,O,the former being pale violet and stable below loo, whilst the latteris pale red and is decomposed only by boiling water. The saltsD. Ralareff, Zeitsch. nnorg. Chem., 1914, 88, 133; A . , ii. 446.R4 A. Rosenheim and T. Triantaphyllides, Rer., 1915, 48, 5 8 8 ; A , , i i , 463.85 R. F. Weinland and F.Ensgraber, Zeitscli. aitorg. G’hem., 1913,84, 340;A . , 1914, ii, 132INORGANIC CHEAIISTRY. 59Ag(R/InP,07),3H,0 and Ba(MnP,0,),,5H20 are obtained byprecipitation.Siniilarly, the alkali metal chromipyrophosphates, M(CrP20i),and sodium bismuthipyrophosphats, Na(BiP,O,), 3H,O, andsodium molybdenopyrophosphate, Na(MoP20,),12H,0, have beenprepared. More complex derivatives are described, such as sodiumthallopyrophosphate, Na5[T1(P,0,),],6H,O, orNaTlP,O,,Na,P,O,, 6H,O,and two sodium f erripyrophosphates, Na,Fe,(P,0,)3,9H,0 andNa,Fe4( I',0,),,28H20.Since cerium pyropliosphate is readily soluble in hydrochloricacid it may be noted that this may be used as a rapid and quanti-tative method of separating cerium and thorium, as was firstdiscovereld by Carney and Campbe11.86Group VZ.Ths extensive use of elementary selenium as the basis of plioto-electric cells and the valu5 of these instruments in modern physicaland astrophysical research is now fully recognised.A pasticularlysensitive form of selenium has been prepared.87 If vitreousselenium, melted a t ZOOo, is cooled rapidly under pressure i t istransformed into a new variety, violebgrey in colour. Itl consistsof slender crystals which are very sensitive photoelectrically, butvery unstable. By using a solid solution of this substance invitreous selenium it is possible t o prepare a very sensitive photo-metric cell.An int'eresting investigation has been made of the equilibriumconditions existing in aqueous solutions of sulphurous acid, thealkali metal hydrogen sulphites and metabisuIphites.@ The lightabsorptive power of sulphur dioxide' as gas and in solution is wellknown, and i t was thought possible that evidence might be gainedof the constitution of the isomeric forms of metallic sulphites froma spectrophotometric examination of these salts.This expectation,however, has not been realised. When sufficient care has beentaken in the preparation of the solutions i t is found possible alwaysto obtain the1 same values for the light absorptive power of sulphur-ous acid. It was otherwise, however, for the alkali metal hydrogensulphite solutions, for the absorptive power was found in these toincrease with time. Owing to the limits set by the apparatus, themost convenient strength was found to be O*06SO2/2.Solutions of86 R. J. Carney ant1 E. TI. C'ampbell, J . L t ) ) j e r . C'11e)n. ,Yoc., 1914, 36, 1 1 : ~ ;87 L. Angel, Bull. SOC. cAiu2., 191.5. riv]. 17, 10; A.3 ii, 163.68 C. S. Garrett, T., 1915, 107, 1324; A., ii, 714.A . , 1914, ii, 58360 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ammonium, sodium, potassium, and rubidium hydrogen sulphiteswere made, and their absorptive power examined from time t otime. This was found t o reach its maximum within about four t ofive weeks. A solution of sodium hydrogen sulphite was thenfreshly prepared, part being kept in the dark and part in thelight. After twenty-six days both were examined, and while thelight solution showed the maximum absorptive power, the darksolution exhibited only very little selective absorption. On expos-ing the dark solution to the light i t developed in ten days amaximum absorption similar t o the light portion, and remainedconstant.Similar results were obtained with solutions of themetabisulphites. Obviously, theref ore, the seat of the light absorp-tion does not’ lie in thel equilibrium :NaHSO, + NaHSO, S Na,S,O, + H,O.Again, the normal alkali sulphites exhibit no selective absorptioneven after long exposure t o light. It may be mentioned t h a t theregion of selective absorption observed with the above solutionscorresponds with that which appears in the spectrum of sulphurdioxide. The absorption cannot, however, be due t o an hydrolysisof the ordinary type,NaHSO, + H20 = NaOH + H2S0,(S0, + xH,O),since in that case the absorptive power would decrease with thebasicity of the metal, but the reverse is actually observed.Thewhole plienoniena are to be explained by the reactions:I. H20 + NazS20, Z 2NaHS0, (reaction in solution).111. H,SO, z? S0,,xH20 (reaction in solution).From the measurements of the’ absorptive power the relative quanti-ties of SO,,xH,O present in equivalent solutions of the variousacid sulphites am calculated, and these quantities are found toincrease’ with increasing strength of t h s base, that is to say, equili-brium I1 is shifted more to the right the stronger the parent baseof the! acid sulphite.Mention may be made of work on the preparation and proper-ties of the tetrathionates. The usual methods for the preparationof these compounds are unsatisfactory owing primarily t o the factthat the presence of any thiosulpliate accelerates the decompositionof the tetrathionate.Pure sodium and potassium tetrathionatescan be prepared by the following method, in which the thiosul-phate is not allowed to. remain in presence of the htrathionate.89To a cool solution of iodine in alcohol a saturated aqueous solutionof sotliuiii or potassium thiosulphate is added drop by drop. The99 &I. Sander, Zeitsch. angew. CItem., 1915, 28, 9’73; A . , ii, 629.11. NaHSO, + NaHSO, Na2S03 + H2S0, (light reaction)INORGANIC CHEMISTRY. 61tetrathionate, wliich separates as i t is formed, is collected andwashed with alcohol in order to free i t from iodine and iodide.The salt is then dissolved in water and again precipitated byalcohol. After drying over sulphuric acid the salt may be keptfor many months without undergoing decomposition. Aqueoussolutions of tetrathionates slowly decompose, the principal reactionbeing K2S,0G = K,SO, + SO, + 2s. Some thiosulphate is, however,formed a t the same time. The decomposition is very slow even a t1 OOo, but the presence of thiosulphates catalyses the reaction.Tetrathionic and persulphuric acids not only possesa similarconstitutions, OH*S02*S-S*S02-O13 and OH-SO,*O*O.SO,-OH re-spectively, but exhibit various anal~gies.~O The tetrathionates formwith ammonia, pyridine, and hexamethylenetetramine compoundscorresponding in composition, external form, and solubility withthose given by the persulphates.91 Compounds of liexamethylene-tetramine with magnesium, cobalt, and nickel tetrathionates, likethose of the corresponding persulphates, contain 8H,O. The follow-i ng have been prepared : ZnS,0,,4NH3, T\TiS,0,,6NH3,where M stands f o r zinc, cadmium, copper, nickel, and cobalt;MS,0,,2C,H1,N,,8H,O, where M stands for magnesium, nickel, andcobalt.MS,0,,4C,H,N,Some new measurements of the vapour pressure of iodine havebeen made between 50° and 95O92 which form an extension of someearlier measurements between Oo and 55°.93 The method employedwris tile passage of a measured volume of air over pure iodine. Theair and iodine1 were1 passed into a solution of sodium carbonate,which was afterwards acidified. The liberated iodine was reducedwith hydrazine and then precipitated as silver iodide. The results,together with those of the previous investigation, can be1 expressedby log p= -- 106.3930 +- 46.611 log 1'- 0-031677T, and still better bylog p=97622 - 2863*54j(T - 19).If iodine is dissolved in anhydrous perchloric acid, cooled by iceand salt, and t h e solution oxidised with ozone, iodine perchlorate,I(C10,)3, 2H,O, separates in greeuieh yellow needles which may be90 F. Calzolari, Atti R. Accad. Lincei, 1915, Lv], 24, i, 921 ; A . , ii, 629.91 G. A. Barbieri and F. Calzolari, Zeitsch. anorg. Chern., 1911, 71, 3 4 7 ;p2 G. P. Baxter and M. R. Grose, J . -4rner. Chent. Xoc., 1915, 37, 1061;93 G. P. Baxter, C. P. Hickey, and W. C. Holmes, ibid., 1907, 29, 127;A . , 1911, ii, 889.A . , ii, 416.A., 1907, ii, 25362 ANNUAL REPORTS ON THE PROGRESS OF CHEMTSTRP.washed with cold perchloric acid. The reaction takes place asfollows : I, + 6HC10, + 03= 31(C104), + 3H20.94On heating basic iodine sulphate with sulphur trioxide ill asealed tube a t 100-120° for one hundred and forty hours, iodinesulphate, 12(S04)3, is obtained in yellow crystals. Iodine iodate,1(103)3, is formed on warming iodic acid with concentrated phos-phoric acid (D 1.70).The statements made as to the preparation of the various modi-fications of manganese sulphide are somewhat contradictory, andmethods are given for the preparation of these without difficult^.^^The green modification may be prepared by the addition of freshly-prepared ammonium hydrogen sulphide t o a solution of manganouschloride cr eulphate containing some ammonium chloride. Therose-coloured modification is first precipitated, but soon changesinto the green modification. If hydrogen sulphide is passed forsome time through a faintly acid solution of a manganous salt thered modification is precipitated. Rose-coloured manganese sulphideis precipitated by tlie addition of an alkali sulphide to a solutionof a manganous salt. Both the rose and re'd varieties are convertedinto the green modification by trituration,E. C. C. BALY.94 F. Fichter and I€. Kappeler, Zeitsch. anorg. Chem., 1915, 91, 134; L4.,95 V. M. Fischer, J . Russ. Phys. Chem. SOC., 1914, 46, 1481, 1519; A., ii,ii, 253.462, 487

ISSN:0365-6217    

DOI:10.1039/AR9151200027

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART I.-ALIPHATIC DIVISION.IT may a t once be said that the review of the literature of thepast year dealing with the chemistry of aliphatic compounds hasnot proved to be a particularly satisfactory task. Although thereis, on every hand, abundant evidence that research of the mostvaried and valuable nature is a t present being vigorously prose-cuted, it is, nevertheless, not from the pages of the scientificjournals that this information is to be gleaned. Recent publica-tions, in fact, give little o r no index of the directions in whichmost of the research on organic compounds is now being con-ducted, and although much might be said as the result of anexamination of recent patent specifications, i t would not be inharmony with the character of the Annual Reports to limitthe account of the year’s work to technical applications of thescience.This state of affairs is, after all, only a natural conse-quence of the abnormal conditions which prevail, but the impres-sion left in the mind of the reviewer after an impartial scrutinyof the literature, both home and foreign, is that the purely scien-tific advances recorded during the1 year in this branch of the subjecthave indeed been meagre.The bulk of the journals remains very much the same as usual.The number of papers, and the general nature of the problemsdescribed, also show an apparent similarity to those of previousyears, b u t the papers themselves generally lack a definite objective,and are in many cases interim communications published with theview of disposing of incompleted topics.This tendency, which isrecognisable in journals from all sources, may be unavoidable, butis an aggravation of what was in normal times a regrettable featurein many publications.With these factors in operation, the present Report must ofnecessity differ in many respects from its predecessors. Severalimportant branches of aliphatic chemistry automatically disappearfrom the review owing to a reason which must appeal to all workersin this branch of the subjec6lack of the necessary material.664 ANKUAL REPORTS ON THE PROGRESS OF CHEMISTRY.With theee restrictions, it, has been no easy matter t o weave theisolated results into a connected narrative, and no apology isneeded for the1 fact that different groups of compounds are treatedin widely varying detail, which, on first inspection, might, appeardisproportionate.Hydrocarbons.Substances which are in universal and urgent demand areunlikely to be the subject of detailed scientific examination solong as attention is, f o r the time being, focussed on their economi-cal production and use.It is therefore not surprising to findthat, during the period under review, the simpler hydrocarbonshave been studied by the engineer rather than by the chemist,and that the pagers of the scientific journals contain few referencesto1 these compounds. After a search through patent and statisticalliterature i t is almost refreshing to fall back upon the strictlyacademic discussion as to the origin of petroleums, which is stillbeing continued with some vigour.The great efficiency of cata-lysts, and the controlling influence of pressure in promoting thesynthesis of hydrocarbons of varied constitution, have again beenquoted in support of the idea that natural paraffins arise frominorganic sources, and not from biological decompositions.1 It isperhaps well that such views should be freely ventilated, as theymay lead t o results of practical importance, but if they are acceptedit is difficult tol explain away the existeam of optically active petrol-eums, even by the ingenious suggestion2 that, as the primarycause of optical activity in organisms is unknown, the occurrenceof the phenomenon in natural paraffins is no index of theirorigin.Evidently much systematic work remains to be doneon this subject before any definite conclusions can be drawn, buti t would appear that if the statement that the optical activityof mineral oils is diminished by exposure to a high temperaturecan be definite'ly verified, or refuted, the whole question would befinally settled .3So far as aliphatic hydrocarbons are concerned, the chief interestof the synthetic chemist is evidently, far the present, centred onthe reactions of unsaturated members. Catalytic methods ofhydrogenation continue to attract much attention, but show littlevariety, either in the choice of catalysts o r in the conditions underwhich they are used, althongh there is a natural tendency to avoidprocesses which involve either high temperature or heavy pres-sures.There is also little1 progress to report in connexion withN. Kishner, J . Russ. Phys. Chem. SOC., 1914, 46, 1428; A., ii, 473.2 A. E. Tschitschibabin, ibid., 1915,47, 714; A . , i, 637.3 C. Engler and W. Steinkopf, Bey., 1914,47, 3358; A,, i, 205ORGANIC CHEMIS'I'KY. 65the caoutchouc problem, although Harries has contributed alengthy paper,4 where many new experimental facts are recorded,which lead to still another formula for natural caoutchouc. It isdifficult to resist the feeling that, in this respect, we are calledon to change our ideas too frequently, and i t may be we'll todelay any detailed discussion of these results, but the essentialidea in tlie new formula is the construction of a Cz0 sing by therepetition of the group *CIT2-CH:CMe*CH,* five times.The struc-ture tl.us obtained certainly accounts readily f o r the facts thatat least two distinct varieties of ( ( regenerated caoutchouc " areknown, and that the ozonides obtained from them yield differentdecomposition products, but the time has not yet come for thefinal adoption of a structural formula for the caoutchouc complex,particularly as the controversy regarding the polymerisationproducts obtained from pure isoprene is still unsettled.5 Appa-rent-ly, however, there is no inherent objection to the adoption of ahomocyclic structure containing no fewer than twenty carbonatoms, as evidence is accumulating which points t o the idea thatthe stability of a ring system is affected by many other considera-tions than that of tension alone.6Greater satisfaction is found in directing attention to the variedand useful reactions which are now being carried out withacetyleae.Alt'hough foreshadowed by the work of the past threeo r four years, t$is development has now assumed amazing propor-tions, and ha; opened up the way for many processes of technicalimportance\. It is almost impossible to give an idea of the varietyof the synthetical reactions based on acetylene, particulaxly whenpromoted by catalysts, but an excellent account, which deals withfundamental examples, has been contributed by Tschitschibabin.7The conditions are there described under which acetylene reactswith ammonia to give several pyridine bases, the reaction probablytaking place through the intermediate formation of aldehyde-ammonia.Similarly, the hydrocarbon reacts with hydrogen sul-phide to give thiophen, apparently in good yield and in a conditionreadily purified. Of considerable interest, also, is the statementthat acetylene, in contact with alumina, is converted a t 400°into a mixture of aromatic hydrocarbons in which benzene ispresent to the extent of less than 10 per cent. From the resultsof other investigations it is probable that the methyl homologuesof benzene are formed in this reaction, and there is much to be4 C. Harries, Annalen, 1914, 406, 173;5 C. Harries, Ber., 1915, 48, 863; A . , i, 703.N. A. Rosanov, J. Russ. Pliys. Chem. Soc., 1915, 47, 691; A ., i , 657.7 A. E. Tschitschibabin, i b i d . , 7 0 3 ; A . , i, 635.REP.-VOL. XII. DA . , i, 27766 ANNUAL REPOnTS ON THE PROGRESS OF CHEMISTRY.said f o r the suggestion,* recently revived, that the reactions ofacetylene are responsible f o r the formation of the coal-tar hydro-carbons and their accompanying derivatives. This idea is furthersupported by the observation that phenol is produced in reactionsin which certain transformations of acetylene were carried outunder free access of air. The field of technical application whichis opened out by these results promises to be highly fruitful, parti-cularly as various other reactions of acetylene have now beenutilised in patented processes. Thus, the conversion of the hydro-carbon into acetaldehyde by the action of acids containing mercurysalts 9 has by simple modifications 10 been elaboratied into methodsf o r obtaining acetic acid.From every point of view it may be said that the study ofunsaturated aliphatic hydrocarbons is in a satisfactory condition,as new problems are continually being unfolded, which are notonly in themselves of great int'erest, but give promise of highlyimportant applications.AIcohols and their Derivatives.Although the simpler aliphatic alcohols are a t present thesubject of much investigatioa, the results are seldom to be foundin the lkerature, and, in addition, the references to such closelyrelated derivatives as aldehydes and ketones are, for the mostpart, meagre and unattractive.No useful purpose would be ,servedby summarising any but a few of t'he papers which deal with thisbranch of the subject, but reference may be made, in passing, toa few specific reactions that have le'd to the formation of importantindividual substances or mark an advance in experimental methods.Thus, f o r example, Wohl describes an extension of his workon the synthesis of aldehydes through the agency of the corre-sponding acetals,ll which has resulted in the isolation of glycer-aldehyde in d- and Z-forms.The resolution into active constituentswas effected by treating r-P-aminolactaldehyde dimethylacetal withZ-menthylcarbimide and separation of the active earbamides thusformed by crystallisation. The process was obviously not unat-tended with difficulties, and, after removal of the amino-group bymeans of nitsous acid followed by hydrolysis under mild conditionswith dilute sulphuric acid, the corresponding active forms ofglyceraldehyde were obtained, unfortunately only as syrups. A8 R.Meyer and H. Fricke, Ber., 1914, 47, 2765; A . , i, 207.9 Fr. Pat., 474246; A., i, 773.10 Fr. Pat,, 473158; A., i, 645; Pr. Pat., 467778; A., i, 2 ; Fr. Put., 467515;l1 A. Wohl und F. Momber, Ber., 1914,47, 3346; A., i, 216.d., i, 2ORGANIC CHEMISTRY. 67significant statement made in the original paper is that theseproducts polymerise with ease, and this suggests that the directsynthesis of the active fructoses and sorboses may yet be carriedout on the lines laid down by Schmitz.12Research of the above nature on unstable aldehydes has un-doubtedly made great progress in recent years, and mention shouldbe made of a reaction which may add to the number of thesecompounds available for examination.By means of a, standardapplication of the Grignard reagent one of t'he two alkyloxy-groups of an acetal may be eliminated, saturation being, of course,completed by the addition of an alkyl group. Taking ethoxyamtalas an example,l3 two products result, which yield, on hydrolysis,the same substituted acetaldehyde :OEt CH,*CH(O Et ), + 0 Et* CHR* CH,*OE t --+ R*CH,*CHO.OEt *CHR*CH,*OEt -+ CHR :CH*O Et 1 The mechanism of the final hydrolysis evidently differs in the twocases mentioned above, but the process appears capable of con-siderable application, and may prove useful, although the hopealways remains that, with the extensive study of catalysts now inprogress, the universal method of preparing aldehydes may yet befound in the oxidation of the corresponding alcohol.It would bevery desirable if the formation of ketones could be similarlycon trolled.PoEyhydroxy-compounds.-Work on these compounds has f o r themost part followed standard lines, but nevertheless presents somefeatures of interest. Thus, for example, it has been shown thatthe tendency displayed by ethylene glycol to be transformed intoacetaldehyde extends to other compounds of the general typeCH2X*CH2Y, and the change may be brought about by very simplereagents.14 This is an important observation, as the capacity ofthe group CR,(OH)*CH(OH)* t o pass into CH,*CH< in simplereactions has a direct bearing on the vexed question of themechanism of fermentation.It may be noted a t this stage thatthe use of Grignard reagelnts in the preparation of glycols fre-quently gives rise t o irregular results, and fresh examples illus-trating this lack of uniformity have recently been encountered.15For example, starting with ethyl dimethylmalonate and magnesiummethyl iodide, the essential products obtained were0 H CM%* C Me2= C O,E t and OH* CMe,*CMe2- CMe,*OH.l2 Ann. Report, 1913, 77. 13 E. SpBth, Monatsh., 1915, 36, 1 ; A., i, 262.l4 C. Neuberg and B. Rewald, Biochem. Zeitsch., 1914, 67, 127; A., i, 214.C. Neuberg and 0. Rubin, ibid., 77 ; A., i, 215; C. Neuberg, ibid., 71 ; A., i, 214.l6 A.Kalischev, J. R'USS. Phys. Chem. Soc., 1914,443, 427; A., 1914, i, 918.0 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.This tendency of the ester groups t o react unequally is more pro-nounced when ethyl diethylmalonate is similarly treated, as in thiscase no glycol was formed. The same result was also obtainedwhen homologues of methyl iodide were employed in the prepara-tion of the Grignard reagent, and the generalisation is made thatthe normal reaction only proceeds smoothly according to the mole-cular proportions CRlRZ(CO,Et), + 4MgR31, where R1, R2, andR2 represent methyl groups.The subject of ring formation from glycols has also receivedattention,16 and it is evident, in the glycol series a t all events, thatthe general principles governing the formation of alkylene oxidesare not yet fully understood.On the other hand, definite evidenceis now available which establishes the constitution of the cyclicstructures formed when polyhydroxy-compounds enter into con-densation with aldehydes or ketones, a problem bearing onsynthetical work in the sugar group. Taking glycerol as anexample, the two alternative formula: of these derivatives may berepresented by y H,--0, f: il ;O Hand in the case of glycerol isopropylidene ether and glycerolbenzylidene ether both compounds are constituted according t oformula II.17 The method adopted was to methylate the com-pounds and, by hydrolysis, to isolate the corresponding glycerolmethyl ether. I n each case the same product resulted, and themethyl group was shown to be situated in the a-position.Thestructure thus established seems to be general in its applicatioiiand extends to methyleneglycerol, which is resolvable into activecomponents, and thus also corresponds with formula 11.18 Workof this nature is obviously capable of extension to the problem ofsolving the consLitution of the glycerophosphorie acids, althoughit is to be noticed that a distinct advance has been made in thissubject during the year. Thus, a-glycerophosphoric acid has beensynthesised19 by the oxidation of sodium ally1 phosphate, and anexperimental method devised whereby the a- or P-substitution ofthe glycerophosphates may be determined with some degree ofcertainty.20 As the whole question of the preparation of estersl6 A.Franke and F. Lieben, Monatsh., 1914, 35, 1431; A., i, 490.l7 J. C. Irvine, J. L. A. Macdonald, and C. W. Soutar, T., 1915, 107, 337;l9 0. Bailly, Compt. vend., 1015, 160, G G 3 ; A . , i, 492.2o L. Grimbert and 0. h i l l y , ibitl., 207; A . , i, 7 3 .A., i, 209. 18 D. H. Peacock, ibid., 815; A . , i, 767ORGAN I C CHEMISTRY. 69fruiii glycerol is beset with difficulties, attention may with advantagebe drawn to a number of papers which are suggestive in theirexperimental details. Thus, the varying effect of different catalystsin the preparation of triacetin has been ascertainedtl and althoughit is shown that sulphuric acid is the most effective catalyst, thefact that less energetic reagents may be employed with advantagewill find applications. Another useful practical detail is mentionedin a description22 of the preparation of fly-distearin.As is wellknown, the production of this and similar compounds fromBy-dibroniopropyl alcohol is complicated by the simultaneousformation of triglycerides and fatty acids. These difficulties maybe overcome by the substitution of lead salts for sodium salts, andalthough the yield of distearin in the particular reaction nowunder consideration did not exceed 20 per cent., the result. wustbe considered satisfactory.Turning t o related problems, the1 study o€ mixed glycerides, whichrecently promised to a.dd. materially to the interest of this sectionof the subject, has languished during the past two years, althoughthere seeins no good reason why the complete stiructure of theseiniportaiit compounds should not be fully determined with thoexperimental methods now available.Then, again, the catalyticreduction of unsaturated fats having been brought within therange of manufacturing processes is another subject which is nowless prominent in the literature than formerTy. This is, of course,a perfectly natural development, and recent papers have, f o r themost part, been restricted to tho academic discussion as to whethermetallic nickel or an oxide of nickel is the responsible agent incatalytic hydrogenation. The evidence is now clearer than twoyears ago, and reference may be made to two investigations23 theresults of which, taken conjointly, point emphatically t o the ideathat metallic nickel is an inferior reagent in this important reactiont o the oxide o r other oxy-compounds.In last year’s Report attention was drawn to the fact that theconfiguration of optically active polyhydric alcohols involves con-siderations which are usually ignored.I n a compound of thisnature, such as the alcohols related to the sugars, the terminalCH,*OH groups apparently do n o t possess the property of freerotation, bub in virtue of the attractive and repulsive forcesexercised by the remaining liydroxyl groups assume preferentiallyJ. B. Senderens and J. Aboulenc, Compt. rend., 1914, 158, 581; A . ,1914, i, 379.22 R. R,. Renshaw, J . Amer. Chem. SOC., 1914, 36, 537; A., 1014, i, 477.23 E.Erdmann, J . pr. Chem., 1916, [ii], 91, 469; A . , i, 770; W. Siegmundand W. Suida, ibid., 442; A., ii, 62670 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.fixed positions. The idea was originally put forward to explaincertain reactions of mannitol, and has now been tested by physicalmethods.24 Mannitol, s&dimethyl mannitol, and y&l;-tetramethylmannitol all possess the property of increasing the conductivity ofboric acid to very much the same extent, while other methylatedmannitols give negative results. Again, mannitolmonoacetone andmannitoldiacetone occasion only very slight changes in the con-ductivity of boric acid, so that evidently the two terminal hydroxylgroups of the parent mannitol are differently arranged in spacerelatively to the neighbouring hydroxyl groups.The results thussubstantiate the formula for mannitol which was referred to lastyear, and point to the existence of a new complexity in a subjectalready sufficiently complex.Before leaving this subject, mention should be made of anothermethod whereby the properties of fractions of polyhydroxy-mole-cules may be studied. Partly methylated derivatives of thesecompounds are already known, and similar compounds in whichsome of the hydroxyl groups are replaced by acyl residues haverecently been described.25 Compounds of this type offer manyopportunities for structural research, and a single example willindicate sufficiently clearly how they are obtained. Mannitoltri-acetone was converted by partial hydrolysis into mannitolmono-acetone, which, by the action of benzoyl chloride in presence of abase, was acylated to give tetrabenzoylmannitolmonoacetone.When hydrolysed under mild conditions the unstable acetoneresidue was removed, and a tetrabenzoylmannitol was thus formed.The examples quoted in the original paper are sufficiently strikingto show that the principles involved are of general application, and,as already stated, the future possibilities of these compounds areof the utmost importance.The Sugar Group.I n last year’s Report it was indicated that current views regard-ing the structure of the reducing sugars are in a state of fluctua-tion, and that future research would add further complications t othe constitution of even the simpler carbohydrates.I n this con-nexion attention was drawn t o Fischer’s discovery of a third formof methylglucoside,26 the existence of which might be dependenton a new, and hitherto unsuspected, type of attachment of a methylgroup to the reducing group of the sugar, or, alternately, to a24 J. C. Irvine and Miss E. S. Steele, T., 1915,107, 1221; A., ii, 669.25 E. Fischer, Ber., 1915, 4$, 266; A . , i, 118.2R Rer., 1914, 47, 1980; A., i, 57ORGANIC CHEMISTRY. 71different internal linking in the sugar molecule. The second ofthese alternatives is the more attractive, as its adoption involvesthe recognition of new types of reducing sugars. There is now nodoubt, in the particular case of glucose a t least, that the oxygenatom of the ring may connect not only the a- and &carbon atoms,but other pairs of atoms as well.Thus, i t has been shown27 thatFischer’s (( y-methylglucoside ” is a mixture of two stereoisomerides,and, on methylation followed by hydrolysis, gives rise t o a formof tetramethyl glucose different from that prepared from a- o rP-methylglucoside. This a t once proves the existence of a newf orm of glucose, resembling the y-oxidic varieties with respect toglucoside formation, but differing in a remarkable degree in itsbehaviour towards most reagents. As this form of the sugar,termed provisionally I ‘ y-glucose,” has not been isolated in, the freestate, its properties can only be deduced from those of the corre-sponding tetramethylated derivative, but it is evident that itsreactivity far exceeds that of a- o r P-glucose.Thus, the compoundenters into condensation with alcohol with extreme ease, andreduces alkaline permanganate solution instantly. I n the lattercase, the reaction gives rise t o a new form of tetramethylgluconicacid, which, in turn, may be converted into an isomeric variety cftetramethylgluconolactone. From this result, and from theevidence afforded by reduction, the f ormulze provisionally ascribedto tetramethi1 y-glucose and to the parent sugar from which i t isderived areMeO*CH,[CH*OMe],*CH*CH*OH and ~O*CH,*[CH*OH],*CH:.CH.OI-IL@J ’ I -0-I n all probability the other reducing sugars exist in similar forms,and thus a most extensive field of research awaits development.16 is highly desirable that the structure of y-glucose should bedefinitely settled, as it is most unlikely that derivatives of thisspecially reactive form of a common sugar are unrepresented inimportant natural processes, but many experimental difficultiesstand in the way.I n the future development of the problem thecharacterisation of P- and y-lactones of the hexonic acids willdoubtless play an important part, and the work on this subjectinaugurated by Nef is invested with a new interest, and is fortu-nately being continued.28Another experimental development in the sugar group, the resultsof which should in time be far-reaching, is the preparation ofdefinite derivatives in which selected hydroxyl groups are substi-27 J. C . Irvino, A. W. Fyfe, and T.P. Hogg, T., 1915, 107, 524; A , , i, 381.28 0. F. Hedenburg, J. Amer. Chem. SOC., 1915, 37, 345; A., i, 7672 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tuted while the remaining hydroxyl groups are exposed, and canthus take part in further reactions. The partially methylated sugarswere the first representatives of this type of compound, and theirpreparation has opened up the way for the production, on similarlines, of other derivatives. Up t o the present, however, the experi-mental work in this field has t o a large extent been appliedto polyhydric alcohols rather than t o sugars, and this is anadvisable preliminary in dealing with the members of the sugargroup, but a considerable advance has been made by clearing upthe many difficulties which attend the preparation of glucose-monoacetone.29 Reference has already been made to the prepara-tion of dibenzoyldulcitol and tetrabenzoylmannito130 by acylationof the corresponding isopropylidene compounds, followed by theremoval of acetone by gentle hydrolysis.It is easy t o see thatthese compounds will receive useful application in sugar synthesis,but in the meantime attention may be drawn to a simpler but lesseffective method of combining different acyl groups with the sugarI 11 olecule .31By decomposing tetra-acetylbromoglucose with silver benzoate,a benzoyltetra-acetyl-P-glucose has been obtained, and the generalreaction is capable of wide variation, although it is difficult t o seewhat the ultimate object of synthetical work of this descriptionmay be beyond improving the details of general practical methods.Interest is, however, attached t o a series of papers by Hudsonand his pupils describing the properties and constants of anumber of penta-acetates of simple sugars as prepared by well-developed processes. Many interesting points are raised in thesepapers, particularly the observation that galactose penta-acetateexists in three distinct forms.32 The variety of the compound firstisolated by Erwig and Koenigs, and subsequently described byFischer and Armstrong, melts a t 14Z6 and shows [a], + 2 5 O inchloroform solution.As is usually the case with such compounds,when boiled with acetic anhydride and zinc chloride it is convertedinto an isomeric variety (m.p. 95'5O) which is strongly dextrorota-tory in all solvents. It is now shown that the direct acetylationof the sugar gives rise t o a third, more soluble, penta-acetate, themelting point of which is not far removed from 95O, but which isdecidedly lzevorotatory. There is a strong probability that thiscompound is derived from a form of galactose corresponding withthe new y-glucose, particularly as evidence already exists pointing23 3. C. Irvine and J. L. A. Macdonald, T., 1815, 107, 1701.3O E. Fischer, Zoc. cit.31 G. ZemplQn and E. D. LBsz16, Ber., 1915,32 C. S. Hudson and €1. 0. Parker, J. Anzer. Chenz. Xoc., 1915, 37, 1689;915; A . , i, 651.A . , i, 652 ; C. S. Hudson, ibid., 1591; A . , i, 651ORGANlC CHEMISTRY. 73to the fact that galactose shows a distinct tendency to form deriv-atives of three types.33 The examination of the rotatory powersof isomeric a- and P-penta-acetates of sugars has also been continuedwith the object of testing Hudson's generalisations on this sub-ject, with the general result that fresh evidence in support of thistheory has been obtained.Thus, the sum of the molecular rota-tions of the glucose penta-acetates is in good agreement with thesame value determined for the two acetylated methyl glucosideswhen the rotations are taken in solvents other than benzene.34This disposes of an apparent exception to Hudson's rule.Other problems connected with the optical activity of sugarscontinue to attract workers, and, in particular, the phenomenonof mutarotation has received considerable attention.The vexedquestion of the part played by water in promoting the, changea Z P in a reducing sugar has again been raised, and resultsobtained which, on first inspection, appear to be contradictory.It has been shown, f o r example, that the mutarotation of sugarsproceeds normally in anhydrous f ormamide solution,35 the solutesalso showing a normal molecular weight in this solventl. Thisevidence is certainly opposed to the, hydrate theory of muta-rotation, but, on the other hand, a definite proof is now availablethat in aqueous solution the rotatory changes are due to associa-tion with the solvent. When tetramethyl a-glucose, which containsonly one hydroxyl group, is dissolved in dilute aqueous boric acidsolution the conductivity of the system gradually rises to a maxi-mum, which persists when mutaxotation is complete, The reason-able deduction from this result is that a second hydroxyl groupbecomes attached t o the sugar molecule, and that the final equili-brium is not between the siniple a- and P-sugars, but between thecorresponding oxonium h~drates.3~ The deductions made in thepaper now under discussion are, of course, dependent on the prin-ciple established by Boeseken 37 that exaltation in the conductivityof boric acid is only induced by compounds where two hydroxylgroups are attached to neighbouring carbon atoms.It may benoted, however, tha€ numerous results recently to hand substantiateBoeseken's views,3* and indicate that they may be applied to consti-33 J.C. Irvine and A. Cameron, T., 1905, 87, 900.34 C. S. Hudson and J. K. Dale, J . Arner. Ghem. Xoc., 1915, 37, 1264; A., i,35 J. E. Mackenzie and S. Ghosh, Proc. Roy. SOC. E d i n . , 1914-15, 35, 22;36 J. C. Irvine and Miss E. S. Steele, T., 1915, 107, 1230; A., ii, 661.37 Ann. Report, 1913, 79.38 J. Boeseken and pupils, Rec. traw. chim., 1915, 34, DG; A . , ii 136; ibic!.,501.A., ii, 301.2 7 2 ; A . , ii, 667.D'74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tutional problems with a considerable amount of certainty, parti-cularly as they are supported by the results of othex physicalinvestigations.39 Returning to the problem of mutarotation, itwould appear that the mechanism of the process varies with thenature of the solvent employed, but the whole question, like everyother problem in the sugar group, is rendered vague and uncertainuntil i t has been shown what part (if any) is played in the processby isomeric forms of the sugar conforming t o the y-type.Although numerous processes ar0 available whereby reducingsugars may be degraded to lower members, they generally offerconsiderable experimental difficulty, and a simple method of effect-ing such changes will be welcomed, particularly as i t seems to beof general application and to give good yields.When glucono-lactone in alcoholic solution is saturated with ammonia, dglucon-amide is formed, and this, on subsequent treatment with hypo-chlorous acid, is decomposed according to the scheme:R*CH(OH)*CO*NH, + R*CH(OH)*N:C:O -+ R-CHO.The change is thus an application of the Hofmann reaction, andthe fact that a 50 per cent.yield of d-arabinose was obtained inthe example quoted above speaks for itself sufficiently.40 Befmeleaving the subject of the simpler carbohydrates, attention shouldbe drawn to two important papers which deal with structuralproblems of some interest. In the course of a research,41 theinitial object of which was apparently the elimination of theamino-group from the glucosamic acid residue, nitrous acid wasallowed to act on ethyl benzylideneglucosamate. Under theseconditions of substitution, it might have been expected that thecustomary dehydration which accompanies this reactioa in thecase of glucosamine derivatives would have been avoided, but theunespctled r e d t was the formation of a diazo-ester :This relaction may be manipulated to explain the Walden inversionalready recorded in the conversion of glucosamine into eitherglucose cu: mannose, but it is in some ways opposed to the view42that the essential action of nitrous acid on amines is the formationof the simple nit'rite.The result mentioned above is, however, of4O R. A. Weerman, Proc. K . Akad. Wetensch. Amsterdam, 1915, 17, 1163;41 P. A. Levene and F. B. La Forge, J . Biol Chem., 1915,21, 345; A., i, 786.d2 P. Neogi, Z'., 1914, 105, 1270.G. Calcagni, Gazzetta, 1914, &, ii, 447; A., ii, 14.A., i, 387ORGANIC CHEMISTRY. 75considerable importance, particularly as evidence is now available 43that chitose may be regarded as as-anhydromannose.GEucosides.After a period of marked activity and success, the biochemicalsynthesis of glucosides by means of enzymes has in the past yearfailed to yield any outstanding results.Although numerouspapers on this subject have appeared,44 they are, for the most part,records of hedious processes and experimental difficulty. This isnot surprising considering the nature of the hydroxy-compoundscoupled with the sugar residue.On the other hand, by means of methods more familiar t o theorganic chemist, several important glucoside syntheses have beeneffected. I n particular, attention should be drawn to the usemade by Fischer of theophyllineglucoside, one of the purine gluco-sides already described by him.The introduction of a phosphoricacid residue into the compound, and the consequent synthesis ofa definite nucleotide, is not only in itself of great importance, butthe experimental method adopted is probably quite general in itsapplication. The essential reagent employed was phosphorylchloride, and the reaction, which was carried out in pyridinesolution, ultimately yielded hydrated theophyllineglucosidephos-phoric acid, t o which the empirical formula :[C7H70,N,*C,H90,*HP0,], 2H,OPurine Glucose Phosphoricresidue. residue. acid residue.is ascribed.45 This successful development of glucoside synthesisis most gratifying, but is evidently surrounded by profound experi-mental and constitutional difficulties. Other examples of increas-ing the substitution in glucosides are furnished by the alkalinecondensation of helicin with various hydroxy-ketones.46 Takingone specific case in illustration, the reaction between the glucosideand phydroxyacet'ophenone proceeds according to the scheme :CH:C H* COG*O-C,H,*CHO + CH,*CC)*C,H,*OH --+ G*O/\ /\1 / 1 1\/ \/OHwhere G represents the sugar residue.The essential reactioninvolved is, of co8urse1, a st'andaxd one, but the research is worthy43 P. A. Levene and F. B. La Forge, J . Biol. Chem., 1915,21, 351 ; A . , i, 782.44 E. Bourquelot, M. Bridel, and A. Aubry, Compt. rend., 1015, 160, 214,45 E. Fischer, Ber., 1914, 47, 3193; A., i, 296.46 G. Bargellini, Gazzetta, 1914, 44-, ii, 520; A., i, 62.571, 674, 823; 161, 41; A., i, 76, 382, 501, 703, 82976 ANNUAL REPORTS ON T H E PROGRESS OF CHEMISTRY.of mention, as the synthesis of glucosides with long side-chains isof great importance, and must be extended so as to throw light onthe general mechanism of cleavage reactions.I n otlier respects, the synthesis and examination of glucosideshave promelded on perfectly normal lines.Disaccharides and Polysaccharides.Comparatively few papers dealing with this division of thecarbohydrates have appeared during the past year, and the resulfsdescribed are frequently amplifications or corrections of oldobservations. Some points, however, should be noted.Those whohave worked with maltose o r lactose are well aware of the diffi-culty in fixing standard values for the melting points or specificrotations of simple derivatives of these sugars, the identificationof which is in consequence restricted to osazone-formation. I n thecase of the octa-acetates, the values have now been standardised.47The important point emerges in the course of this work thatbenzene is not a suitable solvent in which to compare specificrotations in the sugar group, and, further, evidence is furnishedthat the linking of the glucose and galactose residues in lactoseis the same as that of the two glucose residues in cellose.Thisis an impolrtant observation which, in time, may be of value whenthe structure of cellulose once more receives attention.Naturally enough, investigations on cellulose have recently foundno place in the scientific literature, but some progress has beenmade in the study of the structure of starch.It has been shown48that, by biochemical agency, rice starch may be degraded intodefinite polyamyloses in much the same manner as potato starch.Whatever prospect there may be, however, of solving the questionof the constitution of the starch complex by this or other methodsis seriously affected by the increasing evidence that the small phos-phorus-content in starch is not adventitious, but exists as a definitecombine'd c ~ n s t i t u e n t . ~ ~It is with considerable diffidence that any reference is made t orecent papers by Panzer,50 in which it is claimed that, when certaincarbohydrates are acted on successively with hydrogen chlorideand ammonia, the products acquire diastatic properties.Thisresult, if substantiated, is of obvious importance, and is evidentlythe outcome of Panzer's earlier work 011 the action of these reagents47 C. S. Hudson and J. M. Johnson, J . Amer. Chem. SOC., 1915, 37, 1270 ;48 H. Pringsheim and F. Eissler, Ber., 1914, 47, 2565; A . , i , 382.49 A. W. Thomas, Biochem. Bull., 1914, 3, 403; A., i, 6.1276; A., i, 502, 503.Zeitsch. physiol. Chem., 1915,93, 316, 339; 94, 10; A., i, 325, 326, 653ORGANIC CHEMISTRY.. 7’1011 enzymes. It must be admitted, however, that the experimentaldetails are by no means convincing, and it is perhaps sufficienta t this stage merely to call attention to the work.Acids and their Derivatives.Standard methods of preparing the simpler aliphatic acids area t the present time gradually giving place to processes whichdepend on catalytic effects, and numerous instances might bequoted to illustrate this point.The methods referred to are, how-ever, generally described in patent literature and present no theo-retical novelties, aIthough i t is interesting t o note that, in theparticular case of the catalytic oxidation of acetaIdehyde to aceticacid, manganese compoucds are extremely efficient agents whichwork smoothly without the use of oxygen under pressure. Thisefficiency of manganese salts in oxidation processes is a developmentwhich was only to be expected, and deserves wide recognition anduse. Among other compounds which may ultimately be u t i l i din working methods for oxidising aldehydes to acids axe the simpleorganic per-acids, the examination of which has recently beenconsiderably exten$ed,51 but, on the whole, no strictly novelpreparations o r reactions involving aliphatic acids have beennoted.Optical Activity.As in last year’s Report considerable space was devoted to opticalactivity, it is perhaps undesirable that the, subject should be sorully dealt with on this occasion.Several valuable and suggestivepapers bearing on this topic have, ‘however, appeared during theyear, and as the compounds involved are, for the most part acidsor their simple derivatives, i t is most conveniently dealt with a tthis st’age. Practical advantage has been taken of the scheme bymeans of which the configurations of the active lactic and glycwicacids were detlermined,5z in that Abderlialden is now in a positionto assign a definite configuration t o d-epibromohydrin in virtue ofits conversion into Z-glyceric acid.53 .The various steps in the trans-formation are shown below, not so much with the assurance thatthe configurations involved are established in these changes, bul,as examples of reactions which open up a route t o the synthesis oioptically active fats and similar derivatives.5451 J. D’Ans and A. Kneip, Ber., 1915, 48, 1136; A., i, 768.52 Ann. Report, 1914, 65.53 E. Abderhalden and E. Eichwald, Ber., 1915, 48, 113; A., i, 115.64 I b i d . , 2880; L4., i, 21078 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Allylamine + ap-dibromoaminopropane -+ d-dibromohydrin(bromine.) (resolved by tartaric acid.) (nitrous acid.)d-dibromopropionic acidd-dibromohy drin\ *Oa % d-epibromohydrin + Z-bromolactic acidEvidently most of the above reactions were complicated by exten-sive racemisation and the possibility of inversion is very great, butinspection of the scheme shows that a number of importantreagents are now available in active forms, and these should addmaterially to the resources of the synthetical chemist.At thesame time it may be remarked that the reactions of epichloro-hydsin and epibromohydrin are frequently complex, and the appli-cations of these compounds fall short of what might reasonably beexpected from consideration of the highly reactive groups presentin the molecules.Additional examples of such irregularities arefurriished by the varied action of Grignard reagents on these com-pounds, and it may be well, a t this stage, to call attention oncemore to the fact.55An advance of a more fundamental nature is the realisation ofthe, idea that optical resolution may take place when an inactivecompound is crystallise'd from an active solvent.66 This result wasobtained in the course of a research the object of which, equallyfundament'al in its nature, was to resolve an inactive, acid by com-bination with another active acid in place of a base. On adding amolecular proportion of Z-malic acid to a solution of potassium racemate, crystals having the composition of potassium hydrogen race-mate separated. The product was, however, dextrorotatory owing tothe presence of a salt of d-tartaric acid.Alteration of the condi-tions showed this result to be invariable. Again, when potassiumhydrogen racemate was dissolved in a hot aqueous solution ofZ-malic acid and the liquid cooled, the material which separated,although consisting essentially of unaltered race'mate, was dis-tinctly dextro'rotatory, and thus contained some potassium hydro-gen d-tartrate. There is a peculiar satisfaction in the fact thatthese results were obtlained with compounds which have played animporta.nt part in the history of optical activity, and the develop-ment of the research will be awaited with much interest.From studies of resolution it is but a step to the considerationof racemisation and the Walden inversion, and it is significantthat many publications deal with the latter type of problem.55 S .I. Iocitsch, J . Russ. Phys. Chem. SOC., 1904, 36, 6 ; A., 1914, i, 375.56 A. McKenzie, T., 1915, 107, 440; A., i, 380ORGANIC CHEMISTRY. 79Attention may be drawn to a suggestive paper,67 in which it isshown that active phenyl-ptolylacetic acid is much more prone toracemisation than mandelic acid. This a t once shows that theattachment of carbonyl and hydroxyl to the asymmetric atom doesnot of necessity result in extreme optical instability, and that thelability of a hydrogen atom is probably the responsible agent insuch cases of racemisation.This may be explained in various ways, the simplest view beingthat a purely desmotropic change of the following nature takesbut in order to accommodate the effect of catalysts, the authorsmake the further suggestion that an unstable additive compoundis first formed.The possible transformations of this complex arefully discussed in the original paper, and afford not only a satis-factory explanation of this special type of racemisation, but areminder to the synthetical chemist that the carboxyl group is byno means so simple as is generally supposed. The whole questionof the mechanism of addition to unsaturated molecules is evidentlyone which still requires e~t~ensive research, and the suggestion thatthese reactions take place in three distinct stages should not bei g n o're d .58I n an important study of racemisation,59 recently contributed,some highly novel results are described which add a new featureof complexity to the change.Optically active Z-phenylbromoaceticacid reacts readily with water, and, as in the case of the corre-sponding chloro-compound, the hydroxylation is accompanied byextensive racemisation, and results initially in the formation of amixture of r- and Z-mandelic acids. This does not, however, markthe end of the reaction in this particular instance, as the opticalrotation gradually assumes a positive value owing to the ultimateforrr.ation of a slight excess of the d-acid. Not only so, but, parti-cularly when aqueous acetone is used as the solvent, the racemisa-tion is complete before the halogen has been entirely displacedfrom the bromo-acid.Several factors might contribute t o theseresults, but, of various alternatives, i t is difficult to find anexplanation which is more satisfactory than that put forward bythe authors, who suggest that the following consecutive reactionstake place(:57 A. McKenzie and Miss S. T. Widdows, T., 1915, 107, 702; A . , i,s8 S. Reich, J. pr. Chem., 1914, [ii], 90, 177; A . , i, 206.69 A. McKenzie and Miss N. Walker, T., 1915. 607, 1685,81480 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I. Hydroxylation of the Z-bro'mo-acid (rapid),Z-Ph*CHBr*CO,H + H20 =11. Bromination of the hydroxy-acids (slow),r- and Z-Ph*CH(OH)=CO,H + HBr =111. Hydroxylation of the bromo-acids (rapid),r- and d-Ph=CHBr*CO,H + H,O =A new feature in the study of the Walden inversion is maskedby an attack on the problem from the physical point of view, inwhich the influence of the solvent in affecting the change is takeninto account.That the effect of the solvent is considerable wasonly to be expected, but the fact that in acetonitrile the resultsmay be the opposite of those obtained in aqueous solution empha-sises once more the difficulties which accompany all transforma-tions of optically active compounds.6° The importance of takingthe effect of the solvent into account is further enforced by theevidence, now available, that, in the particular case of the con-version of phenylchloroacetic acid into mandelic acid, the hydro-lysis is essentially due to the action of the solvent water on theanion.61Although the individual effect of reagents in promoting opticalinversions remains t'o a large extent obscure, and apparently i r r egular, some definite generalisations have been developed in thecourse of the voluminous work on this subject. One example ofsuch regularity is the fact that when thionyl chloride and silveroxide are used successively to substitute and regenerate a hydroxylgroup, the process always results in inversion.I n view of thisuniformity, the changes may proceed according to either of thetwo alternative routes shown below :HBr + T- and Z-Ph-CH(OH)*CO,H.H,O + r- and d-Ph*CHBr*CO,H.HBr + T- and d-Ph*CH(OH)*CO,H.d-X*CI -+ Z-X*OH ./+ (1) . . .where X denotes the part of the molecule attached to the groupundergoing substitution.No attempt is made in this scheme toallocate an inversion effect to the individual reagents, as thegeneralisation extends only t o their successive action. As is wellknown, active lad,ic acid has been the subject of considerable6o G. Senter and H. D. K. Drew, T., 1915, 107, 638; A., i, 535.G. Senter, T., 1915,107, 908; A., ii, 538ORGANIC CHEMISTRY’. 81attention in this type of inquiry, and it has now been showiiG2that, in its behaviour towards the above reagents, the compoundundergoes inversion according to the second scheme. This addsanother example to the list of cases which show that reactions ofthe type (2) occur only when an alkyl group is attached to theasymmetric carbon atom. I n the same paper a suggestive com-parison is made of the action of phosphorus pentachloride andthionyl chloride as chlorinating agents, and a description is givenof the isolation of intermediate sulphinyl chlorides from bothlactic acid and ethyl lactate.I n view of Fischer’s recent workon a related subject, intermediate compounds of this descriptionassume a new interest.It is probably as much the duty of the writer of this Reportto give his opinion of results which appear to him to be mislead-ing as t o direct attention to genuine advances, and, in thisconnexion, some criticism must be applied to Erlenmeyer’s work,to which reference was made last year with some diffidence. Theimportant claim that benzaldehyde can be (‘ activated ” by treat-ment with &tartaric acid seems, on closer inspection, t o be base-less, and evidence is now forthcoming, from the originator ofthe theory of asymmetric induction, that such is the case.Thefact, which might in the light of recent work have been foreseen,that benzaldehyde condenses Gith tartaric acid to give benzylidene-dioxysuccinic acid which is partly esterified, doubtless aff mds theclue to the existence of ‘( active ” benzaldehyde. These benzylidenederivatives are generally highly active and, in this particular case,are l ~ ~ o r o t a t o r y . ~ 3 They are also very soluble in benzaldehyde,and the fact that the ‘(active” specimen of the aldehyde was notdistilled justifies any adverse criticism which may bO made againstErlenmeyer’s claims.64A considerable amount of experimental work of a highly impor-tant nature has recently been carried out on tartaric acid deriv-atives in continuation of previous studies on rotatory dispersivepower and optical superposition, but the detailed consideration ofthe results would involve overlapping with other sections of theReport, and is thus omitted.Attention may, however, atthis stage be directed to a useful practical application whichinay be made of the effect of different solvents in altering therotation of a dissolved substance. This effect was first applied byPatterson to discriminate between compounds of closely relatedstructure, and may be used in the measurement of reaction veloci-62 P. F. Frankland and W. E. Garner, T., 1914,105, 1101.63 E. Erlenmeyer and G.Hilgendorf, Biochem. Zeitsch., 1914, 68, 351 ;e4 E. Wedekind, Ber., 1914, 47, 3172; A., i , 256.A., i, 40882 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ties. I n a recent study of the rotation of ethyl tartrate in solu-tion, the optical effect of isomeric or similarly constdtuted solventshas been a~certained.~5 The results are striking, and indicate thatethyl tartrat'e is a suitable and sensitive medium for use in thisoptical method of settling questions of structure, and itt3 applica-tion is probably unaffected by the observation that it is anextremely difficult matter to obtain ethyl tartrate in an opticallyhomogeneous condition.Balogen Compounds.Nothing need be said under this heading, as a careful scrutinyof published papers has failed to reveal any reaction or theoreticaldiscussion which would make a general appeal.The Grignardreaction still continues to attract workers, but the problemsattacked belong more particularly t o the second section of thisReport, and have generally been developed on standard line,s,although the list of " abnormal " results steadily grows in lengthand complexity. Oxalyl chloxide likewise continues to be a popularreagent, but, in this case also, there are no results which seemto call f o r special mention.Nitrogen Compounds.Diversity of opinion may well prevail as to the precise natureof the nitrogen compounds that may be appropriately discussed inthis part of the Report, and, to avoid overlapping with othersections, i t will be well to adhere to recent practice and to limitconsideration, as far as possible, to compounds which are essen-tially open-chain structures. Adopting this principle, the moreimporbant subjects described in numerous and, in many cases,lengthy papers which have recently appeared fall roughly intothree class-.Reactions of Simple Nitrogen Compozcnds.-The use of amino-compounds of simple type as reagents in condensation reactionsis so widely spread that, in all probability, some importance mayultimately be attached t o the successful preparation of methylensdiamine in the free state, as the result of a series of reactionswhich do not appear to be unduly difficult.66 By the condensationof formamide with formaldehyde, dif osmomethylenediamide maybe produced in good yield, and this, on hydrolysis with hydro-chloric acid, is easily converted into the dihydrochloride ofmethylenediamine :2H*CO*NH2 + R*CHO -+ CR,(NH*CHO), + CH2(NH2),.65 T.S. Patterson and E. F. Pollock, T., 1914, 105, 2322.66 P. Knudsen, Ber., 1914, 47, 2698; A., i, 220ORGANIC CHEMISTRY. 83The free base, which is unstable, was only isolated in solution,and, although comparatively few of its reactions are described,many possible applications of the compound will a t once suggestthemselves now that i t is readily accessible. The higher homo-logous diamines display a great variety of reactions, and theirpreparation by a new method has been rendered available in thecourse of the systematic work carried out by Curtius on thehydrazides and azoimides of acids belonging to the succinic acidseries.67 By application of the scheme shown below, the estersof adipic and pimelic acids were respectively converted into tetra-and penta-methylenediamines, the reactions being also applicable t ocyclic dibasic acids :+ [CH,],&(NH*CO,'Et), + [CH,'In(WH,),(111.) (IV.)The only noteworthy reaction in the above series is the trans-formation of the diazoimide into the dicarbamate (stage 111), butthis change, which is easily effected by heating in alcoholic solution,is simply due t o addition of two molecules of the solvent andelimination of two molecules of nitrogen, followed by rearrange-ment according to recognised principles.I n another paper, which deserves careful study, the questionof the structure of aldehyde-ammonia is once more raised andanswered in a manner which will a t least facilitate the task of theteacher in dealing with this reaction.The formula for acetalde-dydeammonia suggested by Delepine represented the compoundas the trihydrate of trimethylhexahydrotriazine,but in a research the ariginal object of which was t o isolate thecompound in the geometric isomerides demanded by this formula,evidence has been obtained which leads to quite different views.68Working with a specially pure preparation of the compound, themolecular weight, determined by the cryoscopic method in aqueoussolution, is initially in agreement with the formula (C,H,ON),,but the value diminishes until it corresponds with that requiredfor (C,H,ON),.This easy degradation from a trimeride to adimeride is opposed to Dele'pine's formula, which represents astable ring structure, and the suggestion is therefore made thatthe acetaldehydeammonias consist of two o r more of the above67 T. Curhius, J. pr. Chern., 1915, [ii], 91, 1; A . , i, 124.0. Aschan and Y. Vaskio, Ber., 1915, 443, 874; A . , i, 64884 ANNUAL REPORTS ON THE PROCRESS OF CHEMISTRY.residues linked through nitrogen.trimeride may be regarded as:According to this view, theOH*CHMe*NH,(OH)*CHMe-NH2(0H) *CHMe*NH,,and this, in aqueous solution, gradually undergoes molecularrupture as indicated a t the dotted line, being thereby convertedinto the dimeride:It is interesting t o observe that chloral-ammonia loses ammoniaspontaneously, giving rise to a product analogous to the abovedimeride, and, a t the same time, gives diliydroxybistrichloroethyl-ideneimine, NH[CH(OH)*CCl,],, the structure of which is compar-able with that of (‘ benzaldehyde-ammonia.”Considering the value of diazomethane as a reagent, all unex-pected reactions of the compound are specially important, andattention should be directed to the irregular result to which itgives rise in the case of 1 : 2 : 4 : 5 - t e t r a ~ i n e .~ ~ I n place of yieldinga dimethyltetrazine, the reaction involves three molecules of diazo-niethane and the consequent addition of three methylem groups a tthe double bonds: /”? Y==N N--T IN--N CH,<&--N->CH,8 H kH -+ 3CH,N, = 3N, + C H QHApparently the above type of reaction is capable of considerablevariation, as ethyl diazoacetate behaves in a similar mannertowards ethyl azodicarboxylate, in this case a substituted niethylenegroup becoming attached t o the nitrogen atoms with the formationof an authentic derivative of hydraziacetic acid.Co2Et’f + N Il>CH*CO,R + N, + CO,Et.N Co2Et ‘T >CH.CO,E~.C0,Et.N NCar6amides.-It is somewhat surprising to find that reactionsinvolving the use of carbamide a t comparatively high temperaturesstill continue t o attract workers. Naturally enough, i t is difficultt o disentangle any generalisations from the results thus obtainedor to find good reasons for the selection of reacting materials.Among the simpler of these reactions is the observation that, a t atemperature of 170°, carbamide and acetoplienone enter intosymmetrical condensation t o give CPhMe:N*CO*N:CPhMe, but, onthe other hand, under similar conditions ethyl acetoacetate occasions69 E.Miillcr, Rer., 1914, 47, 3001 ; A ., i, 609ORGANIC CHEMISTRY. 85a reaction of greater complexity.70 I n this case, a molecule ofalcohol is lost and the potential ketonic group enters into condensa-tion with two molecules of the carbamide. Speculation as t o thepossible progress of this reaction must be a t least empirical, andis best avoided. The same criticism applies t o the observation thatcarbamide sometimes reacts with unsaturated esters to give theamino-ester where the action of ammonia results in the formationof the acid amide.71 I n such cases it is obviously not the carb-ainide as such which reacts, but its decomposition products, andthese only come into operation a t a temperature at which amide-formation is extremely slow or entirely suspended.A method for the preparation of symmetrically substituted carb-ainides which, although somewhat restricted in scope, will neverthe-less be useful in many ways, consists in the direct reaction of acarbamide with a primary amine in the presence of acetic acid.The normal change is the formation of a symmetrical dialkyl-carbamide according t o the scheme2NH2R + CO(NH3)2= CO(NHR), + 2NH3,but starting from a monoalkylcarbamide and using an amine witha different alkyl group i t is possible to obtain derivatives where Rand R, are unlike.72 Inspection of the original paper gives theimpression that the experimental methods employed are by nomeans difficult and may be developed into satisfactory processes.Evidently all the reactions of carbamide have t o be viewed interms of more than one formula for the compound, and indirectevidence in favour of tlie cyclic structure NH:C<-I is quoted 0in the course of a discussion on the constitution of cyanamide.73I n order t o explain the stability of this compound, and above allits polymerisation by both acids and alkalis, the suggestion is madethat it exists in aqueous solution as an equilibrium mixture ofacidic and basic forms.Y H,NiC*NH, - NH :C: N H c-(acidic form.) (basic form.)On this basis, the different routes followed in the auto-condensa-tion of the compound receive a ready explanation, as in the1 presenceof acid and alkali respectively the basic and acidic forms areremoved from the system, and two different types of molecularrearrangement thus come into operation.70 M.Scholtz, Arch. Pharm., 1915, 253, 111; A . , i, 846.71 E. Philippi and E. Spenner, Monatsh., 1915, 36, 97; A . , i, 222.72 A. Sorin, Ber., 1914, 47, 2437; A . , i , 394.73 E. A. Werner, T., 1915,107, 715; A., i, 78486 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Acid polymerisation-hasic form removed.N N XYNH * 2cF.. -+ N H , ~ \C.NH,“H \NH, \”\NH, \N H...... \NH/A lkaline polym erisa t io n n c i d i c form remozl ed.NH--f XH:C/ \C:NHN J 3 2 2# + 2cNThese ideas serve t o explain a number of the reactions of cyan-amide, including the fact that nitrous acid acts on the compounda t first vigorously and thereafter only slowly, the assumption beingthat the initial action disposes of the free amino-form and that thesubsequent formation of this variety, owing to the readjustmentof equilibrium in the system, is slow.Again, the remarkablereluctance with which cyanamide adds on the elements of waterpoints t o the idea that carbamide and cyanamide are not simplyrelated, and that the open-chain structure for the former compoundis thus not upiversally applicable.A mino-acids.-As t’he result of several recent researches, adistinct advance has been made in the experimental treatment ofoptically active amino-acids, a6 it; is now possible to obtain themethyl homologues of these compounds without danger of race-misation o r the risk of losing trace of the configuration in virtueof Waldeii inversions taking place.These difficulties, in additionto others, attended the older methods of preparation, in which thecorresponding active bromo-acids were decomposed with methyl-arnine, and are overcome by starting the syntheses from the parent.amino-acid in an active form. The various steps involved are bestillustrated by reference to a particular case, and for this purposethe preparation of d-methylalanine from d-alanine may beselected.74By the action of p-toluenesulphonyl chloride, one hydrogen atomof the amino-group is displaced, and the remaining atom may thenbe methylated by t$e jojnt action of methyl iodide and sodiumhydroxide.75 I n the particular case under consideration, theremoval of the arylsulphonyl residue is easily effected by concen-trated hydrochloric acid, and takes place without appreciableracemisation, the complete scheme beingCH,*CH(NH,)-CO,H + CH,*CH(NH*SO,*C,H,) CO,H +CH3*CH(NMe*S0,*C7H7)~C02H + CH,*CH(NHMe)*CO,R,HCl.I n certain cases, however, some trouble was experienced in decom-’* E.Fischer and W. Lipschitz, Ber., 1915, 48, 360; A , , i, 242.7 5 E. Fischer and M. Bergmann, Annulen, 1913,398, 96; A., 1913, i, 710ORGANIC CHEMISTRY. 8 7posing the arylsulphonyl derivatives, but this was overcome by theuse of hydriodic acid and phosphonium iodide. A noteworthyexample involving the application of this joint reagent is the con-version of E-tyrosine into N-methyltyrosine, which has been provedto be identical with natural rhatanin.76 The above general methodwill doubtless be applicable even in cases where the parent amino-acid is not readily available in an active form as the equilibriummethod of resolving inactive acids, first applied successfully t obenzoylalanine,77 is capable of resolving inactive ptoluenesulphonyl-alanine with an accuracy equal to that attained by Fischer in thefirst stage of the scheme illustrated above.78Other work relating to amino-acids is less definite in character,and is largely concerned with the capacity of these compounds t oform anhydrides under conditions which appear t o be so drasticthat all speculation as to the mechanism of t h O changes involvedis excluded.Some dubiety still exists79 as to the part played byglycerol in promoting the different types of anhydride formation,but the essential facts recorded are simple. I n a lengthy paperthe conversion of a number of amino-acids into cyclic anhydridesby heating with glycerol is described, and as the compounds whichresulted are already known, i t is possible to form an approximateidea of the reactions involved. The changes were accompanied bysecondary reactions, and it is not surprising that only racemic pro-ducts resulted.80 I n a more detailed study of the same problem ithas been shown81 that the first product formed is the eyelo-anhydride, followed on continued action by open-chain compounds,the formation of which is, however, attended by decomposition.I n the original paper the supposed function of the glycerol in pro-moting these changes is explained by an ingenious structuralscheme which, in view of the claim that the reactions are com-parable with those resulting in the natural formation of proteins,deserves mention.It would be undesirable t o close this section of the Report with-out reference to new observations which have a bearing on theformation of internal salts from amino-acids.The work wascarried out with cyclic acids, the evidence of ring-f ormation beingbased on changes in optical activity, and leads to the conclusionthat salts of the type H<-'*->O can exist in aqueous solutionNH376 E.Fischer, Ber., 1915, 48, 93; A., i, 138.77 W. J. Pope and C. S. Gibson, T., 1912, 101, 939.'* C. S. Gibson, P., 1914, 30, 32.79 F. Graziani, Atti R. Accad. Lincei, 1915, [v], 24, i, 822, 936; A., i, 781, 869.80 L. C. Maillard, Ann. Chim., 1915, [ix], 3, 48; A., i, 462.Ibid., 1914, [ix], 2, 210; A., i, 12188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.when the ring produced contains as many as six atoms.82 On theother hand, no such cyclic structure containing seven o r moreatoms is formed, the open-chain, NH2*R*C0,H, then persisting.The work referred t'o is interesting as a good example of the useof the polarimeter in the study of constitution and in furnishingstriking examples of the optical effects which accompany ring-formation.JAMES COLQUHOUN IRVINE.PART II.-HOMOCYCLIC DIVISION.THERE has been no lack of material for this section of the AnnualReport this year, for the output of work generally has been fairlywell maintained, and rather more than a year's supply of Germanand Austrian periodicals has become available.Attention may bedirected to H. S. Fry's electronic formula f o r benzene,l which hasbeea recently discussed a t considerable length by its author, andcriticised by A. F. Hollemanz and R. F. Brunel.3 The subject isnot, however, suitable for condensation into a small space, and theorigiiial papers should be consulted.Beact ions.Nitration.-Last year it was mentioned4 that of the six possibletrinitro-derivatives of toluene only three were known, namely, thecommercial product which is 2 : 4 : 6-trinitrotoluene, and the 2 : 3 : 4-and 2 : 4 : 5-trinitrotoluenes.The 3 : 4 : 5- and 2 : 3 : 5-derivativeshave now beeln prepared by decomposing the diazonium nitratesderived from 3 : 5-dinitro-p and o-toluidines respectively withsodium nitrite,5 and a sixth isomeride, which can only bO the2 : 3 : 6-derivative7 has been isolated from the products of nitrationof toIuene.6 Several intexesting papers deal with the relative82 W. A. Noyes and R. S. Potter, J. Amer. Chem. SOC., 1915,37, 189 ; A . , i, 79.1 Zeitsch. physikal. Chem., 1911, 76, 385, 398, 591 ; J . Amer. Chem. SOC.,1914,36, 248, 262, 1035 ; 1915,37, 855, 2368; A . , 1911, i, 431 ; 1914, i, 263,675 ; 1915, i, 391 ; ii, 760.2 ibid., 1914, 36, 2495 ; A., i, 9.3 ibid., 1915, 37, 709; A., ii, 332.Ann.Report, 1914, 99.W. Korner and A. Contardi, Atti R. Accad. Lincei, 1914, [v], 23, ii, 464;6 E. Molinari and M. Giua, Zeitsch. yes. Schiess-Sprengstoff-wesen, 1914, 9,1915, [v), 24, i, 888; A . , i, 875, 790.239 ; A., i , 790ORGANIC CHEMISTRY. SYdirecting influence of substituents in the benzene nucleus on theposition taken up by an entering nitro-group, and others with theinfluence of nitro-groups on the elimination of substituents from asubstituted nitrobenzene. A study of the nitration of mixeddilialogenobenzenes to mononitro-derivatives leads t o the followingresults.’ I n o-chlorobromobenzene the substitution velocities causedby chlorine and bromine have the ratio C1 : B r = l : 0.8.I n thecase of o-chloroiodobenzene the ratio is C1 : 1=1 : 1.84. By calcu-lation, then, the ratio in t h s case of o-bromoiodobenzene should beBr : I- 1 : 2-30. As the result of experimentl, however, it is foundto be 1 : 1.75, and i t would, therefore, seem that the two substitu-cnts modify each other’s properties, but the results are not exact,for it is impossible t o estimat\e exactly the error due t o the elimina-tion of iodine from the iodo-substituted benzenes.I n p-clilorobromobenzene the relative velocity of substitutioncaused by the two halogens is Cl : B r = l : 0.96, a ratio differingfrom that found in the case of the ortho-substituted derivative.Nitration of pbromotolueile gives a mixture of 4 : 2- and 4 : 3-hromo-nitrotoluenes, in which tlie former predominates.83-Chloro-5-bromotoluene, which contains three different substitu-ents symmetrically arranged in the nucleus, gives a mono+, di-, andtri-nitro-derivative, all of which are apparently homogeneous.Thefirst nitro-group to enter takes up the position between the methylgroup and the bromine atom, whilst the second most probablyenters the position between the methyl group and the chlorineatom.9Aniline when nitrated in concentrated sulphuric acid solutiongives a considerable proportion of m-nitroaniline. Anilides suchas acetanilide, however, give only the ortho- and para-nitro-deriv-atives. The question, therefore, arose as t o how the anilides ofstronger acids would behave, and the nitration of the anilides ofmono-, di-, and tri-chloroacetic acid has been studied.Theseanilides yield solely ortho- and para-substituted nitro-derivatives,even when nitrated in concentrated sulphuric acid solution. It isnot, therefore, tlie combination of the amino-group with a strongacid that causes aniline in concentrated siilphuric acid t o yieldm-nitroaniline, but possibly a ineta-directing influence of theammonium salt grouping.10When trinitro-$-cumene is heated with alcoholic ammonia, tlie6-nitro-group is readily displaced, 3 : 5-dinitro-6-1,h-cumidine (I) being’ A. F. Hollemaii, Proc. X . Aknil. Wetensch. Amsterdam, 1914, 17, S46 ;Rec. trav. chim., 1915, 34, 204; A . , i, 59, 659.8 A. F. Holleman, ibid., 283: A., i.875.lo E. VotoCek and J. Burdrt, Ber., 1915,48, 1002 ; A . , i , (362.J. B. Cohen and W. J. Murray, T., 1915. 107, 847 ; A . , 79190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.formed. The latter substance is only obtained with difficulty from6-chloro-3 : 5-dinitro-$-cumene, and cannot be obtained from 6-bromo-3 : 5 - dinitro - $ - cumene. I n 5-bromo-3 : 6-dinitro-$-cumene (11)NH,/)3le No2/)Me NO,/\MeMe Ale MeNO,\,NO, B r ( j N 0 , NO,,,,!B~Me Me RiIe(1.1 (11,) (111.)neither the bromine atlom nor the 6-nitro-group is readily displacedby the amino-group, and in 3-bromo-5 : 6-dinitro-11/-cumene (111)similar displacement cannot be eff ected.11Nitroveratrole is hydrolysed to 4-nikroguaiacol (I) by alkalinereagents and t o 5-nitroguaiacol (11) by acids.This interestingresult receives an explanation in the light of the theories of Wernerand Flurscheim. The distribution of affinity in nitroveratrole isshown in 111, in which the thickened lines represent strengthenedaffinities, and i t will be seen that the point of attack for hydroxyl/O-Me0 c-c\N--C’ \C--O-Me o/ \c-c/(1.1 (11. ) (111. )ions would be a t the para-positions with respect t o the nitro-group,whilst the methyl group of the meta-methoxy-group would be themore likely t o be removed by means of hydrogen ions.12Nitration of dimethyl-m-phenetidine a t 70° yields 4 : 6-dinito-3-nitrosomethylaminophenetole (I) and a t 2 5 O a mixture, of thissubstance with 4 : 6-dinitro-3-dimethylaminophenetole (11). Boththe original base and the nitromamine give 4 : 6-dinitro-3-methyl-nitroaminophenetole (111) when nitrated in acetic anhydridesolution.Similar series of compounds were obtained by the nitra-Et OEt OEtNO,/\ ?JO,/\ I INMe-NO,NO, NO*(111. )( , , h e 2 \/W(j vNMegNO0 2(1. ) (11.1tion of diniethyl-ni-anisidine and diethyl-m-phenetidine.13 It isparticularly interesting to note that compounds of the type ( p )AcNH-C6H4-NMeR, where R=MeJ Et, o r Bz, all give on nitrationl1 A. Huender, Rec. trav. chim., 1915, 34, 1 ; A., i, 129.12 D. Cardwell and R. Robinson, T., 1915,107, 255; A., i, 134.l3 F. Reverdin, Bull. SOC. chirn., 1915. [iv], 17, 190, 278 ; A , , i, 524, 878ORGANIC CHEMISTRY. 91the same productl, formulated below, R being expelled, and replacedby the nitro~o-group.~4NHAcNO,! INO,/\h i e - N oSuZph om tion.-Although the naphthalenesulphonic acids aremost important substances in the dye industry, the publishedinformation as to their properties is incomplete, and not whollyaccurate.An interesting paper on the preparation and propertiesof naphthalene-P-sulphonic acid has recently appeared.15 This acidis readily obtained by the sulphonation of naphthalene with con-centrated sulphuric acid (93.7 per cent.) a t 160°, and is freed fromthe small proportion of the a-isomeride, formed a t the same time,by the crystallisation of its trihydrate. Naphthalene$-sulphonicacid forms a well-defined monohydrate also, and it is shown thatseveral of the salts lose their water of crystallisation in two1 stepscorresponding with these two hydrates.The author suggests thatthe oxygen atoms of the sulphonic acid grouping are '' infected " bythe sexavalent sulphur atom of this group, with an inclination tomultivalency andfollowing formulae710H7o":s:o'l0"-H Ibecome quadrivalent.f o r the anhydrous acid and the two hydra€es :This view leads to theIOH OHThe effect of aqueous alkalis on sulphonic acids a t high tempera-tures has been studied. Benzenesulphonic acid is only slowlyattacked by 10 per cent. sodium hydroxide a t 320°, but thenaphthalenesulphonic acids readily give good yields of the purenaphthols.16 The position is reversed in the preparation of thehydroxy-derivatives from the chloro-hydrocarbons, f o r in this casechlorobenzene is smoothly converted into phenol by 15-20 percent.aqueous sodium hydroxide a t 300°, whilst a-chloronaphthaleneonly slowly gives a moderately good yield of a-naphthol.17 Inmethyl-alcoholic solutioa, however, a good yield of a-naphthol froma-chloronaphthalene is obtained.1814 R. Meldola and W. F. Hollcly, T., 1915,107, 610 ; A., i, 587.l5 0. N. Witt, Ber., 1915, 48, 743 ; A . , i, 515.l6 K. H. Meyer and F. Willson, ibid., 1914, 47, 3160 ; A , , i, 232.l7 K. H. Meyer and F. Bergius, ibid., 3155 ; A., i, 231.l8 D. R.-P., 281175 ; A . , i, 67492 BNNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.C'l~Zori~z~stio~~.-Com~arison of tlie directing influences of variousgroups in the chlorination of aromatic coinpounds shows that theamino-group far surpasses all others, and is followed by the groupshydroxyl, alkyloxyl, and acetylamino in this order 19 :NH2>OH>OAlk>NHAc.The chlorination of phenacetin, which contains the two lattergroups, by liypochlorous acid,20 o r by chlorine evolved from acliloroamine aiid hydrochloric acid,21 gives a product which consistslargely of 2-chloroaceto-pphenetidide (I).The isomeric 3-chloro-OEt 0 Etp , c 1\/N EIAc/\()Claceto-pplieiietidide ('11) is obtained by the acetylation of 3-cliloro-pphenetidine. This substance is obtained in a yield of 90 percent. of the theoretical by tlie reduction of. pnitroplienetole withtin aiid liycirocliloric acid.22 The formation of by-products con-taining chlorine has frequently been observed in the reduction ofaromatic nitro-compounds t o amiiio-compounds in this manner, aridis proliably due t o tlie intermediate formation of aryl-hydroxyl-amines and cliloroamines,~3 which can be represented in the presentcase as follows:0 E t OEt OEt OEt/\ /\ /\ /\\/I I -+ I I + 1 I -+ I\)*NH,\/NHCI\/NHlOII NO2Tlie fact that 3-chloro-p-phenetidine is obtained in this niannerunaccompanied by 2-chloro-pphenetidine may well be due t o thegreatly superior directing infiuenoe of the amino-group t o that ofthe ethoxy-gr ou p .It is interesting to note that whilst 2-nitroresorcinol dimethylether gave a mixtnre of 2-aminoresorcinol dimethyl ether, and achloro-2-a1ninoresorcinol dimethyl ether on reduction with tin and19 F.S . Kipping, K. J. P. Orton, S. Ruhemann, and J. T. Hewitt, Brit.30 F. Reverdin and F. Diiring, Ber., 1899, 32, 152 ; A., 1899, i, 366.21 I<. J. P. Orton and H. King, T'., 1911, 99, 1190 ;22 Miss W. G. Hurst and J. F. Thorp, Zoc. cit.23 E. Bamberger, Ber., 1805, 28, 245 ; S. Gabricl and R. Stelzner, BcT.,Assoc. Report, 1915 ; Chert&. News, 1915,112, 152.compare Miss W. G.Hrirst' and J. F. Thorp, ibicl., 1915, 107, 934 ; A . , i, 707.1896, 29, 303; A., 1895, i, 217; 1806, i, 320ORGANIC CHEMlS'l'RY. 93hydrochloric acid, the formation od a chlorinated by-product inthe reduction of 2-nitroresorcinol diethyl ether does not appear toIiave been observed.24Bmminntion.-The bromination of aromatic amines by a solu-tion of bromine in acetic acid tends to give1 rise, with meta-substi-tubed anilines and aniline itself, t o tribromo-derivatives ; withortho- and para-substitnt'ed anilines, t o dibromo-derivatives.Theamino-group is of greater directive influence than any other grouptested ; thus ptoluidine, acetyl-pphenylenediamine, and pphenet-idiiie all give 2 : 6-dibromo-aniline~.~5When benzylideneaniline dibromide is heated with absolutealcohol, benzylidene-p-bromoaniline hydrobromide is formed. A.Hantzsch and 0. Schwalo26 formulate'd the hydrobromide as a truesalt, C6H4Br*N:CHPh,H3r, in saite of the fact that it yieldsbenzaldehydo-pbromoaniline, CGH,Br*NH*CHPh*OH, when heatedwith aqueous sodium carbonate.C,H,Br*NH-CHBrPh,which these ruthors rejected, has been supported during the yearby H.Franzen and A. Henglein,27 but on insufficient grounds, asIIaiitzsch28 has clearly shown; for the salts of Scliiff's bases areinsoluble1 in ather, and behave physico-chemically as the salts ofweak bases ; moreover, the hydrochlorides can bO converted intoplatinichlorides. 'The formation of benzaldehydo-pbromoanilinefrom benzylidene-pbromoaniline hydrobromide may be an instanceof pseudo-base1 formation :The alternative formula,Retlzictioii .-The value of the1 arylsulphonyl derivatives of amino-compounds for the isolation of this class of compound is seriouslytl i r n inislied hy tlie difficulty of regenerating the original amino-~oitipouiid. Hitherto, concentrate'd hydrochloric acid a t looo o rhigher temperatures has been employed f o r the hydrolysis, a methodwliich frequeatly gives rise t o racemised products in the case ofoptically active amino-compounds, such as amino-acids.It is nowfound t h a t arylsulphonamides and their derivatives readily sufferreduction and fission into thiophenols and amino-compounds whenheated with fuming hydriodic acid and phosphonium iodide a tPh*SO,*NHR + 7HI = Ph-SH + R*NH,,HI + 61 + 2H20.70-100° :24 E. E. Turner, T., 1915,107, 469.25 W. Fuchs, Monntsh., 1915, 36, 113 ; A . , i, 530.2G Bey., 1901, 34, S22 ; A., 1901, i, 37s.27 J . p r . Chem., 1915, [iiJ, 91, 245; A., i , 330.28 Bey., 1015, 48, 1340 ; A . , i, 105394 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The methold is especially suitable for the recovery of optically activeamino-acids from their arylsulphonyl derivatives.Like the arylsulphonamides, arylsulphonyl chlorides may also bereduced t o thiophenols by hydriodic acid, but the free sulphonicacids and their esters cannot be reduced in this ~ a y .~ Q A numberof mono- and poly-thiol-benzenes and -naphthalei= have been pre-pared by the reduction of arylsulphonyl chlorides by zinc or tinand hydrochloric acid.304-Benzeneazoresorcinol diethyl ether (I) gives on reduction withalcoholic stannous chloride, 4-aminoresorcinol diethyl ether. The,product obtained from 2-benzeneazoresorcinol diethyl ether (11)under the same conditions is not identical with 2-aminoresorcinoldiethyl ether, and is probably 4 : 4’-diamino-3 : 5 : 3’ : 5I-tetraethoxy-diphenyl (111), since the reducing agent employed is specific f o rinducing the benzidine change.31OEt OEt f- OEt; 1(1.1 (11.1 (111.)Attempts t o transform m-halogenostyrenes into m-halogenoethyl-benzenes by catalytic reduction we,re unsuccessful, for halogen waseliminated, and the corresponding saturated hydrocarbons wereobtained.Benzyl chloride, under similar conditions, gives toluenein good yield, benzylidene chlorides gives toluene and a smallamount of s-dichlorodiphenylethane, CHClPh*CHClPh, whilstbenzotrichloride, PhCCl,, gives only s-tetrachlorodiphenylethane,CPhC1,=CPhC12.32Hydrogen and palladinised charcoal reduce aryl aminoalkylketones, R* CO*C”H,*NH,, t o the corresponding carbinols,in good yield, whereas other reducing agents givel poor results.33Ozidatio.n.--Little is known as to the nature of the oxidationproducts of polyhydric phenols.Some years ago i t was shown thatpyrogallol became oiidised by air in the presence of barium hydr-oxide to 2 : 3 : 4 : 2’ : 3’ : 4/-hexahydroxydiphenyl (I),34 and it is nowR*CH(OH)*CH,*NH,,29 E. Fischer, Ber., 1915, B, 93 ; A., i, 138.30 T. Zincke and J. Ruppersberg, ibid., 120 ; H. Rennert, ibid., 459 ;J. Pollak (in part with A. Wienerberger), Monatsh., 1914, 35, 1445, 1467 ;A., i, 135, 531, 528, 529.31 E. E. Turner, T., 1915,107, 469; A., i, 396.32 W. Borsche and 0. Heimburger. Ber., 1915, 48, 542 ; A., i, 527.35 C. Mannich and E. Thiele, Arch. Pharm., 1915, 253, 181 ; A., i, 812.34 C. Harries, Ber., 1902, 35, 2954 ; A., 1902, i, 771 ; M.Nierenstein andF. W. Rixon, Annalen, 1912, 394, 249; A., 1913, i, 180ORGANIC CHEMISTRY. 95shown that it yields with air and potassium hydroxide a hex*hydroxytriphenoquinone, which appears to have the co,nstitutionrepresented by formula 11.35OH O H OH OH OH OH OH OH OH OH(1.1 (11.)Similarly, orcinol on oxidation with air in aqueous potassiumhydroxide gives a crystalline quinone, which yields a triaoetate, andprobably has the formula (HO),C,H,Me*C,HMe( :0),*OH.36Resorcinol, when fused with sodium hydroxide, gives, besidesphloroglucinol, a quantity of tetrahydroxydiphenyl (diresorcinol).Since the yield of the latter increases a t the expense of the yield ofphloroglucinol on raising the temperature, it is probable thatphloroglucinol is an intermediate product in the formation olfdiresorcinol.This view supports the constitution usually assignedto the latter substlance, where the hydroxyl groups occupy the3 : 5 : 31 : Ci’-positions.37The easlier results obtlained by oxidising phenols containingunsaturated sidechains with strong ozone were unsatisfactory,resinous products being largely formed; when, howe’ver, 1 per cent.dry ozone is used, eugenol and isoeugenol yield the normal mono-ozonides, which on reduction with zinc dust and acetic acid inethereal solution give homovanillin and vanillin respectively ingood yield.38Friedel and C‘raf ts’ Rea.ction.-An instance of intramolecularcharge has been observed in the, hydrolysis of the alkyl e’thers ofphenol-ketones by Gatt’ermann’s method.When 4etholxy-a-naphthylmetlhyl ketone is heated with aluminium chloride in benzene solu-tion, the normal product, 4-hydroxy-a-naphthyl methyl ketone (I)is obtaine~d, but when no diluent is employed, l-bydroxy-8-naphthylmethyl ketone (11) is produced, together wit(h a-naphthol and thedi-substituted derivative (111) under the combined analytic andOH OH OH‘ COMesynthetic actions of the reagent.35 M. Nierenstein, T., 1915, 107, 1217 ; A., i, 883.36 F. Henrich, W. Schmidt, and F. Rossteutscher, Ber., 1915,48,483 ; A.,i,37 0. von Friedrichs, Arlciv Kern. Min. Geol., 1914, 5, No. 19, 1 ; A . , i, 811.38 C. Harries and R. Haarmann, Ber., 1915, My 32 ; A., i, 133.56496 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.When a-naphthol is heated with glacial acetic acid and zincchloride, a 30 per cent.yield of l-hydroxy-/3-naphthyl methyl ketone(TI) is obtained. The addition of acetic anhydride to the materialsused in the reaction increases the yield t o 80 pe.r cent., and thisfact suggests that the primary product of the reaction is a-naphthylacetate, which then suffers rearrangement.39 I n the analogous casecf phenol, however, neither the addition of acetic anhydride northe use of ready-made phenyl acetate has a favoiurable influenceon the yield, so that the foregoing explanation is not of generalapplicability. It may well be that the intermediate produck in thissynthesis is an organo-metallic derivative, just as is assumed for theFriede'l and Crafts' relaction, and i t is suggested that the yellowcolour pro'duced by the action of zinc chloride on phenol and aceticacid is an indication of the formation of such a compound.40The condensation of s-m-xylenol methyl ethes with acetyl chloridein the presence of aluminium chloride gives a surprising result, forthe acetyl group enters t$e olrtho-position to the methoxy-group.Similarly the xylenyl acetatel gives the ortho-substituted hydroxy-ketone (I), and as a by-product the' diortho-substituted compoundOH OH(11) .41/'\COMeMe! IMe\/(1.1 (11% )The chlorides of anthraquinone-l- and -2-carboxylic acids can becondensed with hydrocarbons by Friedel and Crafts' reaction, giv-ing 1- and 2-benzoylanthraquinones, but the reaction only proceedssmoothly with the coinpounds of the latter type.42 The productsdiffer considerably in their properties, 2-benzoylanthraquinonesyielding colourless antliranols on reduction, whilst l-benzoylanthra-quinones give highly coloured substances which are insoluble insodium hydroxide, and are therefore not anthrano(ls.43The condensation of phthaloyl chloride with aromatic hydro-carbons in the presence of aluminium chloride leads to a mixtureof the corresponding phthaloylic acids and phthalides; thus witho-xylenei, o -xylylpht,haloylic acid, C02H*C,H,*CO*C6H3Me2, anddi-o-x yl ylp hthalide, (C,H ,Me,),C<~f~>CO, are formed ,4439 0.N. Witt and 0. Braun, Ber., 1914, 47, 3216 ; A . , i, 414.40 H. Pauly and K. Lockemann, ibid., 1915,pS, 25 ; A ., i, 146.42 A. Schaarschmidt, ibid., 831 ; A., 566.43 A. Schaarschmidt, ibid., 973 ; A., i, 696.44 M. Copisarow and C. Weizmann, T., 1915,107, 878 ; A., i, 686.K. v. Auwers, ibid., 90 ; A., i, 145ORGANIC CHEMISTRY. 97Phthaliminoacetyl chlorides of the general formula,C,H,O,: N-CR,*COCl,condense with benzene and aluminium chloride to give phthalimino-acetophenones, C,H,O,:N-CR,*COPh, together with by-products (I)and (11) formed by the participation of one of the phthaloylcarbonyl groups in the reaction.459H4*y Ph---?CO---N*CR,*COThe skric arrangement of the methyl groups in mesitylenepermits the introduction of alkyl and acyl groups by means ofFriedel and Crafts' reaction, but not that of the esters of halogen-fatty acids, for instance, met81ipl chloroformate, chlosoacetate, orP-iodopropionate.46The Friedel and Crafts and the Nencki methods have it limitedscope of application to syntheses of phenolic ketones.An importantnew method of synthesising these substances, which are closelyrelated to many natural products, is an extension of Gattermann'smethod of synthesis of phenolic aldehydes from a phenol, hydro-cyanic acid, and hydrogen chloride. By the use of a nitrile in theplace of the hydrocyanic acid, a ketoneimide hydrochloride of thetype CRR':NH,HCl is formed, and this on hydrolysis yields thOketone R-COR'. The entering group takss up the para-position withrespect to a phenolic hydroxyl group.*'Grignard's Beaction.-Magnesium methyl bromide combines withbenzaldehyde in equimolecular proportions in ethereal solution toform a crystalline precipitate.On the addition of a secondmolecular proportion of the aldehyde, the precipitate changes toa viscous mass, which on decomposition with water yields aceto-phenone and benzyl alcohol :PhCHO + MeMgBr = PhCHMwOMgBr.PhCHMe*OMgBr + PhCHO + H,O =It is evident that combinat'ioa takes place between the magnesiumphenylmethylcarbinyl bromide and the second molecular proportionof benzaldehyde, for the supernatant ethereal liquor contains onlytraces of the 1atte.r. The view is put forward48 that an ortho-compound, PhC(OMgBr)(O*CH,Ph)Me, is formed as an intermedi-ate product. The second molecule of benzaldehyde acts as anPhCOMe + PhCH,*OH + OH-MgBr.46 P.Freytag, Ber., 1915,4$, 648; A., i, 543.46 F. Wenzel, Monatsh., 1914, 35, 945 ; A., i, 541.47 K. Hoesch, Ber., 1915,48, 1122; A., i, 820.48 J. Marshall, T., 1915, 107, 509 ; A., i, 409.REP.-VOL XII. 98 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.oxidising agent, itself becoming reduced to benzyl alcohol, a reactionwhich is very similar to the simultaneous oxidation and reductionof benzaldehyde in the presence of sodium hydroxide.2Ph-CHO + NaOH = PhC(ONa)(OH)*O*CH,Ph =The methyl hydroxytoluates behave normally with the GrignardPh*CO,Na + Ph*CH2-OH.reagents, giving hydroxytolyldialkyl-(or ary1)-carbinols,HO*C,H,Me*CR,*OH 49 ;methyl 2-hydroxy-3-naphthoate behaves similarly,50 but methyll-hydroxy-P-naphthoate frequently yields ethylene derivatives ornaphthaquinones owing to the instability of the tertiary carbinols.61The influence of the positions of the halogen and carboxyl groupsin the esters of halogenated aromatic acids on the reaction withmagnesium is as follows: When both groups are in the side-chain,the compounds react with magnesium; when both are uniteddirectly t o the nucleus the tendency to react is much diminished;when the halogen is in the nucleus and the carboxyl in the side-chain, the former is rendered slightly more mobile (ethyl pbromo-phenylacetate does not react, whilst the ortho-compound does so) ;when the carboxyl is in the nucleus, and the bromine in the side-chain, the esters exhibit increased activity towards magnesium ;thus, ethyl o-bromo-o- and m-toluates react,, forming compounds,C,H,Me*C( OH) (CH,*C,H,*CO,H),, although here also the para-derivative is inactive.52A useful method of preparing the otherwise difficultly accewible substituted phenylacetaldehydes has been described, Ethoxy-acetal reacts with the Grignard reagent to give a mixture of twoethers, thus :(OEt),CH*CH,*OEt + MgRX -+ OEt.CHR*CH,*OEt.OEt*CHR*CH,*OEt + MgRX + CHR:CH*OEt.Both ethers are readily hydrolysed by hot 50 per cent.sulphuricacid, giving the same aldehyde, R*CH,*CH0.53Steric Influence.The stezic effect of substituents on the formation of formanilidesfrom substituted aromatic amines, C,H,X*NH, (where X = Me,OMe, C1, or Br), has been studied. I n comparing the relative ratesof formation (with which the percentage of anilide formed runs49 H.Berlitzer, Monatsh, 1915, 36, 191 ; A., i, 533.6o P. Lammer, ibid., 1914, 35, 171 ; A., 1914, i, 409.51 F. Preissecker, ibid., 889 ; A., 5 , 525.52 J. Zalkind and A. A. Schmidt, J . Russ. Phys. Chem. SOC., 1914,46, 681 ;53 E. Spath, Monatsh., 1915, 36, 1 ; A., i, 262.A . , i, 407ORGANIC CHEMISTRY. 99approximately parallel) of the ortho-, meta-, and para-isomerides,the steric hindrance is in the order o>m>p. Comparison of theeffects of the different groups shows that in the o-series the stericinfluence is in the order OMe>Me>Br>Cl; in the 712,Me>Cl>Bs; in the p, OMe>Me>Cl>Br, but the differencesbet$ween the values f o r the halogen atoms is only slight.5‘2 : 6-Diethoxybenzonitrile cannot be caused, under any conditions,to pass into the corresponding ketone, CGH,(OEt),*COR, by theaction of a Grignard reagent, RMgX.55The effect of steric hindrance, on (a) the rate of formation of thenitrates of subst’ituted benzophenones, ( b ) the yield of Schiff’sbases obtained by the condensation of substituted benzophenoneswith aniline and its homologuee, and ( c ) the rate of hydrolysis ofthese Schiff’s bases has been studied.56 The last case is particu-larly interesting.Schiff’s bases yield with alcoholic hydrogenchloride cdoured additive compounds which gradually fade andbecome colourless as hydrolysis takes place. The times requiredfor complete decolorisation we.re as follows :Benzophenone-mil ...................................30-35 seconds.Benzophenone-o-tolil ............................. 44-5 minutes.Benzophenone-m-tolil ............................... 35-40 seconds.Benzophenone-p-tolil .............................. 50-60 ,,p-Tolylphenylketone-anil ........................ 50-60 ,,o-Tolylphenylketone-anil ........................ 19-20 minutes.Benzophenone-mesil ............................ l O + - l l hours.The influence of ortho-substituents is well marked, as one wouldexpect, but it is certainly remarkable that the ortho-methyl groupof phenyl o-tolyl ketone should have so much greater influence thanthe ortho-methyl group of o-toluidine. This result is held tosupport Pfeiffer’s theory of halochromy,57 which requires that theaddition of water to a C:N-linking on hydrolysis should take placeat the carbon, and not a t the nitrogen atom.Thus:Ph,C:rPh + Pb,v==NPh + Pb,CO + HCI,NH,Ph\1 H a H20 H C ICondensation.The condensation of y-ketonic acids with aldehydes has beenstudied with interesting results. The simplest y-ketonic acid,13evulic acid, presents the possibilities that condensation with benz-aldehyde may take place (1) as with a derivative of acetone, yield-ing /3- or $-substituted benzylidenelawulic acids, or (2) as with a54 0. C. M. Davis and F. W. Rixon, T., 1915,107, 728 ; A . , ii, 537.titi E. E. Turner, T., 1915,107, 1459.66 G. Reddelien, Ber., 1915, 48, 1462; A., 1916, i, 48.57 Annalen, 1910,376, 285; 1911,383, 92; A., 1910, i, 852; 1911, i, 788.E 100 ANJSUAL REPORTS ON THE PROGRESS OF CHEMISTRY.derivative of acetic acid, forming the a-substituted acid.Earlierwork has shown that condensation in alkaline solution leads to theb-acid, whilst the &acid is formed by heating the components withanhydrous sodium acetate.58 It has now been shown that, whensodium lzvulate is heated with benzaldehyde and acetic anhydride,that is, under the conditions use'd in Perkin's synthesis of cinnamicacid, a product is formed which has the probable constitution givenbelow, for it yields a-benzylidenelzvulic acid on hydrolysis.59PhCH:$!.CII,*~Me*O.$!~~e*~H,.q:CHPhco--0 O--- coP-Benzoylpropionic acid, CH,Bz*CH,*CO,H, when condensed withbenzaldehpde in the presence of alkali hydroxides o r hydrogenchloride, behaves as a derivative of acetophenone, yielding P-benz-oyl-B-benzylidenepropionic acid (I), which readily gives 3-benzoyl-a-naphthol (11) on heating.When sodium 8-benzoylpsopionate ,J heated with benzaldellydeand acetic anhydride, however, two molecular proportions of waterare eliminated, and y-phenyl-a-benzylidenecrotonolactone isformed 60 :Phy=CH-$!H, + PhCHO Ph$!:CH*y:CH PhOH HOoCO + 0-coy-Ketonic acids also suffer condensation a t the a-position whentheir sodium salts are heated with phthalic anhydride and aceticanhydride,61 the products being double lactones of the type (I)shown below:CH--$=C*C H ?H2 CO*9,H4 I 16 4.CH--- ER~OH HO~CO + 6-co * 8R*O*CO O*CO(1.1The condensation product of 8-ptoluoylpropionic acid andphthalic anhydride, which has been most fully studied, is convertedby sodium ethoxide into the sodium derivative of the diethyl ester(11) of the corresponding dicarboxylic acid.The diethyl ester ie58 H. Erdmann, Ber., 1885, 18, 3441 ; Annalen, 1889, 25p, 182; 1890,258, 129; E. Erlenmeyer, jun., Ber., 1890, 23,-74; A . , 1886, i, 241 ; 1890, i ,375, 495, 1129.59 W. Borsche, ibid., 1915, '€8, 842 ; A., i, 691.6O W. Borsche, ibid., 1914, 47, 1108; A., 1914, i, 686.W. Borsche, ibid., 2708 ; A., i, 251ORGANIC CEEMISTHY. 101unstable, and when liberated from the sodium derivative passesinto the lactone (111) :$XX,--F):C(ONa) *C6H4'C02Et ~ H---yH* CO C,H,* C 0,E tC0.R C0,Et c K*O-CO(11.) (111.)This substance, when heated, loses a molecular proportion ofalcohol, and yields an isomeride of the original condensationproduct (I), which can only be a stereoisomeride, owing its separateexistence to the ethylene linking in the molecule.Both isomeridespass smoothly into the furan derivative (V), possibly through theintermediate product (IV), when he'ated with alcoholic sulphuricacid :C H---fi*CO,H CH--s*CO,H~ R - O H HOOC,H,-CO,H -+ 8 R~O~C~C,H,~CO,H*(IV. 1 (V- 1y-Phenylisocrotonic acid, itself, like its y-hydroxyl derivative(the enolic form of P-benzoylpropionic acid) can be condensed withphthalic anhydride under the same conditions, yielding a-phthalyl-idene-y-phenylisocrotonic acid (VI), which is readily converted intocinnamylidenephthalide (VII). This substance when treated withsodium alkyloxide gives an unstable compound (VIII), which isanalogous to the substance 11, but immediately suffers the loss of amolecular proportion of alcohol, giving the sodium derivative of1 : 3diketo-2-styrylhydrindesne (IX) 62 :PhCH:CH*C===C*C H PhCH:CH*CH:y*$?,H, ~ 1 1 6 4 + bO,H O*CO o*co(VI. 1 (VII.)C( ONa) PhCH :CH-CH: C( ONa) - C,H,*CO,Et --+ Ph c' fT : C H*C<-CO->C,B,(VIII. ) (IX.1The condensation of methyl 2-hydroxy-3-naphthoate with benz-aldehyde in the presence of hydrogen chloride gives methyl2-hydroxy-1-chlolrobenzyl-3-naphthoate (X), in which the halogenC(CHPhCI):y*OH C H ( CHP 11 Cl ) $? 0Or C 6 H 4 < ~ ~ - - - - - CA<CH---- C°CO,Me -----C* C@,'L\lle(X. )atoms are extremely reactive, being readily displaced by othergroups, such as hydroxyl o r anilino-groups.63 When the same esteris condensed with terephthaldehyde a similar product is obtained,only one of the aldehyde groups entering into the reaction.64 Ethyl62 W.Borsche and G . Heimbiirger, Ber., 1915, 4$, 966 ; A . , i, 680.63 F. Friedl, Monatsh., 1910, 31, 917 ; A., 1910, i, 741.64 K. Lugner, ibid., 1915, 36, 143 ; A., i, 546102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.1 : 3-dihydroxy-2-naphthoate similarly forms a condensation product(XI) with benzaldehyde and hydrogen chloride :C(CHPhCI):y*OH CH( CHPhCI)*yO(XI- 1C6H4<c(~~)===~~c0,~t Or C,H4<C(O~~)---r=C.C0,EtThe halogen atom in this substance is even more reactive thanthat in the corresponding monohydroxy-derivative (X).65An unusual and important type of condensation has beenemployed in the synthesis of l-n-pentadecyl-2 : 3-dimethoxybenzene(hydrourusliiol dimethyl etlier).66 After many fruitless attemptsto prepare this compound by the more obvious methods, the follow-ing procedure was adopted : 2 : 3-Dimetlioxyphenylpropionyl chloridewas condensed with sodium dodecinene, and the resulting unsatur-ated ket.one was reduced first to the saturated ketone by hydrogenand platinum-black. Further reduction by Clemmensen’cs method 70gave the required compound :Dynamic Isomerism.T.M. Lowry and IT. SteeleT1 discuss the nomenclature of thephenomenon which is perhaps most generally termed tautomerism,and urge that the expression dynamic isomerism should be used forall cases in which isomerism passes from a static to a dynamiocondition, whilst the words tautomeric and desmotropic shouId beused in the sense of the original definitions.Tautomeric substances are, in this sense, compounds which maybe represented by two alternative formulae; they are not isomwic,but identical, as, f o r instance, 1 : 2- and 1 : 6-di-derivatives ofbenzene.The term desmotropy is reserved for those cases in whicha definite grouping of atoms passes over into an isomeric groupingby a rearrangement of bonds consequent on the displacement ofa hydrogen atom. Several interesting cases of dynamic isomerismhave been investigated this year.a- and a’-Chlmocamphors undergo mutarotation in the presenceof alkali, so that each substance is converted into the same mixture65 H.Nowak, Monatsh., 1914,35, 909 ; A., i, 545.66 R. Majima and J. Tahara, Ber., 1915,4$, 1606 ; A , , 1916, i, 35.i o Ann. Report, 1914, 123.i1 T., 1915, 107, 1382; A , , i, 976ORGANIC CHEMISTRY. 103of isomerides in equilibrium.72 On this fact is based a method ofpreparation of a’-chlorocamphor. a-Chlorocamphor is convertedinto the equilibrium niixture by means of alkali in alcoholic solu-tion. The solution is acidified to prevent further isomeric change,and most of the a-chlorocamphor is then removed by crystallisationa t - 1 8 O . The mother liquors then yield a crude a’-chlorqcamphor,which is purified by fractional crystallisation. Pure a- and a’-chloro-camphors yield on nitration a-chlaro-a’-nitrocamphor and a’-chloro-a-nitrocamphor respect4ively, but on brominatioii each chlorocam-phor yields the same mixture of the two stereoisome4ric chlorobromo-camphors.It seems, therefore, that nitration of thesel ketones takesplace by direct substitution, whilst bromination is the result of theaddition of bromine t o the common enolic form of a- and a’-chloro-camphors, and subsequent elimination of hydrogen bromide. Thelast result affords strong confirmation of Lapworth’s theory 73 of the1halogenation of ketones.H. Leuchs‘4 has sliown that the optically active o-carboxy-2-benzyl-l-hydrindone yields with bromine a mixture of 90-95 percent. of the inactive and 10-5 per cent. of the active brominatedketonic acid :It was to be expected that the addition of bromine to the enolicform of the ketonic acid would yield an optically inactive product,and this author ascribes the formation of the active acid to directsubstitution.Both A.Lapworth75 and K. H. Meyer76 point out that itsformation may be due to asymmetric synthesis caused by the addi-tion of bromine to the enolised form of the acid in the presence ofthe unchanged optically active keto-form, a view which had beenpretiously considered and rejected by Leuchs. Neyer compares theasymmetric synthesis with that of benzaldehydecyanohydrin,77 butLeuchs78 denies the analogy, and points out that i t is difficult t osee why methane, into which substituente such as halogen may beintroduced, should become incapable of substitution when unitedto a ketonic carbonyl group.Incidentally, i t may be noted thatchlorination of the ketonic acid has given a similar result t o thatmentioned ab0ve.7~Formyldeoxybenzoin occurs in two enolic forms, which might be72 T. M. Lowry and V. Steele, Zoc. cit., compare F. S. Kipping, P . , 1905,i3 T., 1904, 85, 30.76 P., 1913, 29, 289.i7 Ann. Report, 1912, 177.i 9 ibid., 1915,48, 1015 ; A., i, 694.21, 125.‘4 Ann. Report, 1913, 63, 102.76 Ber., 1914, 47, 826 ; A . , 1914, ii, 35178 Ber., 1914, 47, 2528; A., i, 411104 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.either structural isomerides having the formulz PhCO*CPh:CH*OHand PhG(0H) :CPh*CHO, or stereoisomerides, both having one ofthese two structural formula. The folrmer view was held pre-viously,SO the first formula being assigned t o the yellow varietyfrom analogy t o benzil, and the second to the colourless variety,which was the more reactive towards Schiff's reagent, this indicat-ing the presence of the aldehyde groap.It is now shown that bothvarieties are oxidised by ozone t o benzil and formic acid, andconsequently have the first formula. They are, therefore, stereo-isomerides.81Acetylacetone forms condensation products with ammonia,primary amines and diethylamine, with loss of water, but not withinethylaniline o r benzylmethylamine; methylacetylacetone,MeCO CHMe* COhIe,combines with ammonia and primary amines, but not with diethyl-amine; dimethylacetylacetone, MeCO*CMe2*COMe, does not suffercondensation with ammonia.These facts suggest that the con-densation is preceded by the addition of the amine t o the enolicform of the ketone, and not to the carbonyl groups2:NeC(OH):CH*COMe+ NH,R -+A case of keto-enol isomerism in it phenol of the naphthalenegroup has been recorded.83 Juglone (8-hydroxy-1 : $-naphtha-quinone) gives on reduction two isomeric hydrojuglones, which arereadily interconvertible. Both yield the same triacetate, but onlyone variety reacts as a ketone, forming a semicarbazone and anoxime. The latter, therefore, has one of the two formula:MeC( OH) (NHR)*CH,*COMe-+ MeC( :NR) *CH,*COMe.CO---RH CO-QH,0H'C6H3<CH( OH) CH Or O=*c64<C(OH) :CH ,whilst its isomeride is 1 : 4 : 8-triliydroxynaphthalene.Evidence has been brought forward in support of the view thatphenylpyruvic acid exists in two desmotropic forms, the free acidbeing in the enolic form, and the normal salts in the ketonic form.The existence of the enolic form, first suggested by S.Ruhemannand H. E. Stapleton,S4 has been indicated by the preparation of anacetzte having the constitution CHPh:C(OAc)*CO,H.85 Phenyl-pyruvic acid and benzaldehyde condense with aqueous sodium80 W. Wislicenus and A. Rutting, AnnaZen, 1911,379,229 ; A . , 1911, i, 303.82 L. Rugheimer, ibid., 2759 ; A., i, 224.f 3 R.. Willstiitter and A. S. Wheeler, ibid., 2796 ; A . , i, 265.84 T., 1900, 77, 239.65 J, Bougault and Mlle. R. Hemmed& Comnpt. rend., 1915, 160, 100 ;J. Scheiber and G. Hopfer, Ber., 1914, 47, 2704 ; A., i, 267.L4., i, 78ORGANIC CHEMISTRY.105hydroxide to give y-hydroxy-a-keto-By-diphenylbutyric acid. Thissufl'ers the loss of a molecular proportion of water when warmedwith hydrochloric acid, giving a substance for which two formulzeare possible :co---yo C(0H) *COCHPh<CHR*OH Co*Co2H + CHPh<CHR.o Or C W C a R - ~(1.) (11.1(R = Ph in the above case. )The same end-product results from the condensation of phenyl-pyruvic acid and benzaldehyde with hydrochloric acid, and manysimilar products have been obtained with other aromatic aldehydes.When piperonaldehyde or cuminaldehyde was used, a mixture oftwo isomeric lactones was farmed. Each of these gave a distinctawtyl derivative, and the view was put forward that they wereskreoisomerides, having, therefore, the ketonic formula I, of whichtwo stereoisomerio modifications are possible, rather than theenolic formula 11, which does not admit the existence of suchisomerides.The amtyl derivatives were represented as C-substitutedco--yo sqCHR*O 'derivatives, OAc*CPh<A similar condensation product obtained by the action of form-aldehyde and hydrochloric acid on a-oximino-8-phenylpropionicacid, and evidently formed by the condensation of formaldehydewith pyruvic acid, has now been examined. It gives an intensecoloration with ferric chloride, and is found by titration by I(. H.Neyer's method to consist almost entirely of the enolic form. Ithas no ketonic properties, nor have its acyl derivatives, whichbehave like O-acyl derivatives. Its properties thus show that i thas the formula I1 (R = H).87The conclusions of Erlenmeyer and Lapworth as to the constitu-tion of t,hese lactones are thus opposed but each of them is appa-rently warranted.It is clear that further investigation of thesubject is required.St ereoisomerism.Racemisation of A cids.-The literature dealing with the raoemisa-tion of acids has been reviewed and discussed by A. McKenzie andMiss S. T. Widdows.88 Optically active acids having the asym-metrio carbon atom in the a-position are readily racemised bymeans of alkali only when a t least one of the groups attached to86 E. Erlenmeyer, jun., Ber., 1905, 38, 3119; A., 1905, i, 783.references given in the next paper.87 N. Hall, J. E. Hynes and A. Lapworth, T., 1915,107, 132.s8 T., 1915,107, 702; A., i, 814.See alsoE106 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the asymmekric carbon atom is a hydrogen atom. Thus, opticallyactive mandelic acid, OH*CHPh*CO,H, and phenyl-p-tolylaceticacid, C,H,*CHPh*CO,H, are readily racemised under these condi-tions, whilst atrolactic acid, OH*CPhMe*CO,H, is not.I n theformer cases, dynamic isomerism is possible, as represented by theexpression RR,CH-CO,H RR,C:C(OH),, whilst in the last caseno such change can take place. The authors, however, do notregard t.his expression as completely satisf actory, and suggest thattlie behavionr of acbive phenyl-ptolylacetic acid (for instance)towards alkali might be represented by some such scheme as tlief o'llowing, whichciated acid:(Active.)postulates the' addition of0 ,..' '.,K OH(Active. )the base t o the undisso-I.',I . * .K VH(Inactive.) (Inactive. )The constitution of the two inactive forms of a substance con-taining two similar asymmetric carbon atoms has been determinedin comparatively few cases. Only two years ago the constitutionsof the two inactive fosrms of a symmetric dialkylsuccinic acid (thedimethyl derivative) were determined f o r the first time by theresolution of one of them.89 a-Diphenylsuccinic acid has now beenresolved into its optically active components by the fractlonalcrystallisation of the brucine salt, and is, therefore, the racemicform. P-Diphenylsuccinic acid is the meso-form, and attempts toresolve it were unsuccessful. Here, also, as in the case of dibromo-and dimethyl-succinic acids, the isomeride of lower melting pointis the racemic acid, whilst in the tartaric acid group the reverseis the case.90 d-Diphenylsuccinic acid has also been obtained,together with diphenyl, d-a&dihydroxy-ap/3-triphenylethane,OH*CHPh*CPh,*OH,P-diphenylsuccinic acid, and diphenylacetic acid by the action ofmagnesium phenyl bromide on Z-phenylchloroacetic acid 91 :C6H5*QH*C0,HCO,H*CH*C,HI, I - C6H5*CHC1*C02H + d-89 A.Werner and M. Basyrin, Ber., 1913, 48, 3229; A., 1913, i, 1302.90 H. Wren and C. J. Still, T., 1915, 107, 444; A., i, 406.91 A. McKenzie, H. D. K. Drew, and G. H. Martin, T., 1915, 107, 26ORG$NIC CHEMISTRY. 107Another interesting resolution is that of the plieiiylglyceric acidderived from cinnamic acid by oxidation.The stereoisomericinactive phenylglyceric acid derived from allocinnamic acid wasresolved many years ago,92 but its isomeride could not be resolveda t thatl time, and there was some discussion as to the reason for itsnon-resolution. It has now been shown that the acid in questionmay be resolved by crystallisation of its morphine salt from absoluteacetone.93Cinvcimic .4 rids urid StiZbeiips.-The configuration of the steseo-isomeric stilbenes has been determined by a method similar t o thatemployed for the cinnamic acids.94 The stable Z-nitro-a-phenyl-cinnamic acid and the labile rrlla-acid behave differently in chemicalreactions. The former when reduced and diazotised yields plieii-anthrene-9-carboxylic acid (111) readily, whilst the latter fails togive a trace of this substance.Moreover, the amino-acid obtainedby reducing the allo-nitro-acid can only exist in the form of saltsor of the lactam, 3-phenylcarbostyril (IV). The stable acid has,therefore, the cis-configuration (I), and the labile acid the trans-configuration (11), the terms cis and trans referring here t o therelative positions of the phenyl groups :(111.) -(11.1 (IV.)When trans-2-nitro-a-phenylcinnamic acid is reduced and theamino-group replaced by hydrogen, allo-a-phenylcinnainic acid isobtained. This has, therefore, the tram-configuration, and i t followsthat the stable a-phenylcinnamio acid has the cis-configuration.These acids lose carbon dioxide when heated a t 300° with bariumoxide under diminished pressure, and the cis-acid yields isostilbenewith a little stilbene, whilst the trans-acid yields much stilbene withsome isostilbene.isostilbene has therefore the cis-, and stilbenethe trans-~onfiguration.~5 The two known modifications of a-methyl-cinnamic acid (m. p. 81--8Z0 and 73-74O) prove to be dimorphousforms of the same acid. Both form the same methyl ester, andcannot be converted into methylindone. Either can be1 converted by92 J. Plochl and B. Mayer, Ber., 1897,30, 1600; A., 1897, i, 525.93 C. N. Riiber, ibid., 1915, 48, 823 ; A., i, 544.94 R. Stoermer and P. Heymann, ibid., 1912,445, 3099 ; A., 1912, i, 974.9s R. Stoermer, Annaten, 1915, 4.09, 13; with L.Prigge, ibid., 20; A.,i, 682, 683.E* 108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the light of a quart,z lamp into aZZo-a-methylcinnamic acid (m. p.91-92Oj, a new modification which forms a distinct methyl ester.This acid is easily converted into 2-methylindone, and hencecontains the phenyl and carboxyl groups in the &-positions toeach other 96 :CO,H c* C €3,C6H5*CH C,H,*C HyO--fl* CH, +The stereoisomeric stilbene dibromides behave differently withpyridine, the a-f orm losing bromine with regeneration of stilbene,whilst the @-form of lower melting point loses hydrogen bromidein thO normal manner, yielding bromostilbene (m. p. 31O). Thisdifference i t i chemical behaviour of stereoisomerides is also shownt o some extent by the dibromocinnamic acids, but here the a-formonly suffers the loss of bromine as such to the extent of 62 per cent.,the remainder losing hydrogen bromide to give a-bromocinnamicacid.8-Z)ibro~mocinnamic acid gives a quantitative yield ofa-bromocinnamic acid. I n the case of aliphatic compounds ofsimilar constitution, dibromocrotonic acid and dibromosuccinic acid,both forms lose hydrogen bromide when treated with pyridine.97I n this connexion, some experiments on the elimination ofbromine from dibromoaiiisylideneacetophenone,OMe*C,€14*CHBr* CHBr. COPh,are of interest. This compound readily exchanges one bromineatom for alkyloxyl when boiled with methyl or ethyl alcohols.When boiled with propyl, isobutyl, or benzyl alcohols, or glacialacetic acid, it is converted into monobromoanisylideneacetophenone,and when boiIed with isopropyl or tert.-butyl alcohols, acetoneor benzoin, into anisylideneacetophenone.98Asymmetric Synthesis.-E.Erlenmeyer, jun.,99 has shown thatwhen benzaldehyde is heated with d-tartaric acid in alcoholic solu-tion, the original rotatory power of the solution is increased, andt h a t the solution, after thorough washing to remove tartaric acid,remains slightly hvorotatory. From this ' Z-benzaldehyde ' amandelo'nitrile having slight Z-power, and a mandelic acid havingslight d-power, were prepared in a chemically, but not opticallypure state. It now appears1 that this 'Z-benzaldehyde' owes itsoptical activity t o certain non-volatile impurities, namely, benzyl-96 R.Stoermer and G. Voht, Annalen, 1915,4#, 36 ; A., i, 684.97 P. Pfeiffer, Ber., 1912, 45, 1819 ; with K. von Swidzinski, ibid., 1915,48, 1048; A , , 1912, i, 618; 1915, i, 793.913 F. J. Wilson and A. A. Boon, Pharm. J . , 1915,94, 486; A . , i, 413.gg Ann. Report, 1914, 68.1 E. Erlenmeyer, jun., Biochem. Zeitsch., 1914,66,509 ; A.,i, 257 ; with G .Hilgendorff, ibid., 1914,68, 351 ; A . , i, 408; E. Wedekind, Ber., 1914, 47,3172 ; A . , i, 256ORGANIC CBEMISTLXY. 109and its etliyl ester, O*CH*CO,HidenedioxysucciniG acid, CHPli<O.~II.CO,H,and there is no longer any de,finite evidince that benzaldeliydemay be regarded as a substance with 'induced' asymmetry having/Hthe formula CPh/ OL, where L represents an unoccupied posi-\Ltion, or an electron.2The formation of optically active mandelonitrile and mandelicacid is held by Erlenmeyer to demonstrate the temporary existenceof 'I-benzaldehyde,' but i t appears more probable that these sub-stances result from asymmetric synthesis.Spir 0-co mpoun ds.An interesting study has been carried out with the aid of splro-compounds.3 I n accordance with Baeyer's strain hypothesis, thenormal angle of the tetrahedron (109O28') has to be altered to anangle of 120° to produce the cyclohexane ring.The question ariseswhether the two side-chains attached to a carbon atom of this ringtake up a symmetrical position with respect to each other and thetwo valencies participating in the ring, in which case the anglebetween them is found by calculation to be 107O16' (hypothesis a),or whether their direction is independent of those of the twovalencies participating in the ring, so that they still remain inclinedto one another a t the tetrahedral angle of 109O28' (hypothesis 6 ) .C,C,(IOT'lG') (j/ C/ 1 ~ o > c < ( 1 O i " 1 ~ ) \c-c~(,o,~&~(a.) (be )If hypothesis a is correct, there should be a greater tendeiicy toform the spiro-compound I than there is to form the ring-com-pound 11, owing to the closer proximity of the groups attached tothe carbon atoms of the side-chains in the former case, and, more-over, the ring-compound I should be more stable than the ring-compound 11:CH,*CH 2>C<CHBr*CO, R -HBrCH2<CH,-CH, CH,*CO,R --+-CH *CH QH*CO,RCH2<cH;*CH :>c<c€€*co21t(1.1CR2<CHBr *CO,R -+ CH*C02RCH,.CO,R -HBr CR2<bH.Co2R(11. )H.Pauly, Biochem. Zeitsch., 1914, 67, 439; A., i, 257.R. M. Beesley, C. K. Ingold, and J. F. Thorpe, T., 1915,107, 1080; A.,i, 816110 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.whereas if hypothesis 71 is correct, then the tendency should bethe same in both cases. The results of experiments on the forma-tion and stability of ring compounds of the two types point clearlyto the correctness of hypothesis a.Organic Rudicles.Siiice the discovery of triphenylmethyl, a large amount of workhas been carrjed out 011 allied substances of the general formulaR,C, and this has been reviewed in previous Reports from time totime. This year there are again several interesting papers on thissubject), and, moreover, different workers have recently beeninvestigating the dissociation of ‘peroxides, hydrazines, anddisulpllides icto free radicles; a brief accocnt of this developmentof the work is given below.ilf etuqziiiioiioid or TP.iar?ll?riethyl.-The removal of the halogenatoms from tetraphenyl-m-xylylene dichloride by means of metalsgives rise to a hydrocarbon, for which two different formulae havebeen advocated.\-CPh, 6 /\CPh,Cl ~ /\CPh,1 1 \) iC‘Pb,\/UPb,ClCP11,(1.1 (11.10. Stark and 0.Garben,4 finding that the properties of the sub-stance were similar to those of Tliiele’s tetraphenyl-p-xylylene, andespecially that i t was indifferent to oxygen, proposed the meta-quinonoid formula (11).W. Schlenk and M. Braunss cannot con-firm Stark and Garben’s results, and find that the product is veryeasily oxidisable. They now show that i t is a bistriarylmethylhaving the formula (I). The reaction proceeds in two stages.One of the halogen atoms is easily removed, giving a substancehaving the properties both of a triarylmetliyl and of a triaryl-methyl chloride, whilst the second halogen atom can be removedby more vigorous treatment, g.iving a bistriarylmethyl. The factthat tetraphenyl-m-xylylene dichloride yields a bistriarylmethyl,whereas the isomeric para-dichloride yields a quinonoid substance,is an indication that metaauinonoid substances do not exist.The intention to prepare the corresponding ortho-compound 6was not realised, for the required tetraphenyl-o-xylylene dichlorideAnn.Report, 1913, 107.Ber., 1915,48, 661 ; A . , i, 517.W. Schlenk and M. Brauns, ibid., 716 ; A . , i, 518ORGANIC CHEMISTRY. 111could not be obtained, the action of all chlorinating agents on t.hecorresponding glycol forming the anhydride.The question whether the coloured triarylcarbinol salts are tobe regarded as carbonium compounds o r quiiionoid derivatives( I ' quinocarbonium " salts) is still under discussion. Two inde-pendent investigations have been carried out with the view ofpreparing tri-a-thienylcarbinol, IIO*Ci ( - C < ~ " ~ ~ ) , , in order t ocompare it with triarylcarbinols. Neither resulted in the isolationof the pure carbinol, owing to its instability; but W.Schlenk andR. Ochs7 prepared the perchlorate in a pure state, and find thati t closely resembles triphenylmethyl perchlorate in physical proper-ties. They hold that the former cannot be represented in thequinonoid form, and that i t is therefore unnecessary to assumesuch form for salts of the latter type, for which the carbonium-salt formula, R,C-X, is adequate. A. E. Tschitschibabin andN. N. Gavrilov,* who prepared a double chloride of trithienyl-carbinol and zinc, 2(C,H3S),CC1,ZnCl2, offer the! alternative ex-planatdons that the chloride has either the carbonium-salt formulaor a formula I analogous to the quinocarbonium " formula 11.(1.1 (11.)Attempts to prepare phydroxytriphenylmethyl have been un-successful. Both fuchsone (111) and p-hydroxytriphenylcarbinol(IV) yield phydroxytriphenylcarbinyl chloride on exposure tohydrogen chloride, hence the usual equilibrium between the twoisomeric forms of the chloride must be assumed.When this sub-Pb,C=/-\-O -+ Ph2C=, /-\/OH\-/-- \-/\GI N (111. )P b,C( OH) C,H,* OH +stance is treated with molecular silver, a molecule of hydrogenchloride is removed instead of the usual single chlorine atom,giving, consequently, fuchsone instead of p-hydroxytriphenyl-methyl. pCarboe thoxy-, pbenzoxy-, and pacet ox y-trip henylcarb-Ber., 1915,4$, 676 ; A . , i, 579.J . Russ. Phys. Chem. Soc., 1914,443, 1614; A., i, 578.Ph,CCl C,H,* 011(IV. 112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.inyl chlorides, however, yield the respective free radicles, but theseare too unstable to be isolated as such.9a-Ketomethyl or Aroxyl RadicZes.-Space forbids more than apassing reference to the organic radicle derived from hydroxy-dinaphthalene oxide (I).It possesses a tervalent carbon atom andhas the “a-ketomethyl” formula (11), but can also react in theisomeric “aroxyl” form (111) with a univalent oxygen atom.1°Methyl-&naphthol can be oxidised to dehydro-l-methyl-P-naphthol,for which there are three possible formulae./\/\/ /\/\:oI ‘ I I l l/\/\/I l l\/‘\/ \/\/ \/\/(IV. ) (V. ) (VI. 1The peroxide formula (IV) is supported by the oxidising proper-ties of the substance; the other two formulae (V and VI) by thesensitiveness to permanganate in indifferent solvents.The com-pound combines with triphenylmethyl t,o f o m triphenylmethyll-methyl-P-naphthyl ether, which has the formula (VII), not (VIII),since i t is not sensitive to permanganate.(VII. )Me CPb,\//\/\:0I l l\/\/(VIII. )It is possible that the formation of this substance is due to thedissociation of dehydrel-methyl-&naphthol into an aroxyl radicle,9 M. Gomberg and R. L. Jickling, J. Amer. Chem. SOC., 1915, 37, 2575;A . , 1916, i, 29.10 R. Pummerer and F. Frankfurter, Ber., 1914,47, 1472 ; A., 1914, i, 714ORGANIC CHEMISTRY. 113but the existence of this cannot be proved by molecular-weightdeterminations or optical methods.11Hydrazines.-The study of the dissociation of tetra-aryl-hydrazines into free radicles has been continued by H.Wieland.12The introduction of nitro- or phenyl groups into the aryl nucleihinders the dissociation, whilst the introduction of methyl,methoxyl, or dimethylamino-groups favours it in increasing degree.Tetra-p-dimethylaminotetr aphenylhydrazine,(NMe,=C,H,),N*hT(C,H,*NMe,),,is colourless in the solid condition, but gives intense yellow solu-tions in indifferent solvents. Molecular-weight determinationsshow that it dissociates t o the extent of 10 per cent. in benzeneand 21 per cent. in nitrobenzene. Its decomposition in solutionis very largely due to the dissociated fragment bis(dimethy1amino-phenyl)nihrogen, (NMe,*C,H,),N, for the decompwition takes placetwice as quickly in nitrobenzene as in benzene solution.Triphenylhydrazine 13 represents an interesting case, f o r thereare two possible ways in which it may dissociate, namely,(1) Ph,N*NHPh + Ph2N+NHPh and (2) Ph,N*NHPh +Ph,NH + NPh.Study of its decomposition in boiling xylene solution indicatesthat the second expression represents the course of the reaction,for the products found are diphenylamine, azobenzene (presumablyproduced by polymerisation of NPh), and quinoneanildiphenyl-hydrazone, NPh:C,H,:N-NPh,.This substance may well beformed by the addition of thO phenylnitrogen (PhN) radicle t o anintact molecule of triphenylhydrazine, and subsequent loss ofhydrogen from the product.J. Stieglitz and G. 0. Curme14 have shown that the spontaneousdecomposition of liydrazobenzene into azobenzene and anilinebehaves as a unimolecular reaction, and represent the course ofthe reaction as a dissociation of hydrazobenzene into aniline and afree radicle, PhN, with univalent nitrogen, proceeding a t ameasurable speed, followed by polymerisation of the PhN radicle(1) NHPhONHPh + YhN + H,N*Ph(2) 2PhN + NPh:NPhto azobenzene with immeasurably great velocity.H. Wieland 15observes that dissociation of a hydrazine containing only twophenyl substituents is contrary to experience, and holds that thel1 R. Pummerer and E. Cherbuliez, Ber., 1914, 47, 2957 ; A., i, 417.l2 H. Wieland, ibid., 1915, 48, 1078; A . , i , 848.l3 H. Wieland and A. Reverdy, ibid., 11 12 ; A., i, 851.l4 Ibid., 1913,46, 911 ; A., 1913, ii, 398.lS Ibid., 1915, 4& 1098; A., i, 850114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.decomposition of hydrazobenzene takes place in two stages, asfollows :(1) NHPh-NHPh + NPh:NPh + 2H,(2) NHPh*NHPh + 2H + 2PhNH,,of which the first proceeds a t a measurable speed, whilst the secondtakes place with immeasurably great velocity.I n order to dis-criminate between the two views, he has studied the spontaneousdecompositions of asymmetric hydrazo-compounds of the typeC6H,*NH-NH-C6H4X. If the view of Stieglitz and Curme iscorrect, a mixture of the three azo-compounds NPh:NPh,NPh:N*C,H,X, and XC,H,*N:N*C,H,X should result, but Wie-land finds that the homogeneous asymmetric azo-compound,NHPh-NH*C,H4XJ is alone produced, as required by his ownhypothesis.Bisz~Zphides.-Tlie properties of diphenyl disulphide have beencompared with those of hexa-arylethanes.The change of colourof the former in benzene and xylene obeys Beer’s colorimetricdilution law, so that a dissociation equilibrium, PhS*SPh BPhS,is not supported.16Diazo-compotcnds.Diazopli enoZs.-The constitution of the internal diazo-oxides, orso-called diazophenols, has again received attention. Last yearKlemencJ17 discussing the three possible f ormulz, pointed out thatWolff’s work had rendered the cyclic diazocoxide structure (I)improbable, and supported the diazonium formula (11) as against(1.) (11.1the quinonediazide formula (111) on the grounds that, (i) diazo-phenols dissolve in concentrated acids without decomposition,(ii) they are only sparingly soluble in organic solvents, and (iii)they are formed in acid solution.G. T. Morgan and J. W.Porter18 now reject formula (11), and conclude that (I) is moregenerally serviceable than (111), although the last two are notirreconcilable. Klemenc’s argument (i) is not answered, but it isshown that sparing solubility in organic media and formation inacid solution are not general properties of internal diazo-oxides.The yellow colour of these internal diazo-oxides, and the non-existence of internal metadiazo-oxides,lg furnish strong argumentsH. Lecher, Ber., 1915,4$, 524; A., i, 532.l7 Ann. Report, 1914, 102.la T., 1915, 107, 645; A., i, 599.l9 See also E. Bamberger, Ber., 1916,4$, 1354; A., i, 1056ORGANIC CHEMISTRE'. 115in favour of the quinonediazide formula (111).The latter formulais also supported by the marked contrast between the reactivityof the internal diazo-oxides and the inertness of ortho-diazoiminesand ortho-diazosulphides. On the other hand, it is urged in favourof the cyclic diazo-oxide formula (I) that (a) the colour of thesubstances i n question is not incompatible with the presence intheir molecules of the group *N:N*O*, for this group is also pre-sent in the coloured diazo-oxides, R*N:N*OR; ( b ) the diazo-complex in internal diazo-oxides may have the same structure asin Wolff's diazotetronic anhydride (IV) in spit.e of the differencesin their properties, for these may be ascribed to the absence of an0 N:N*O/\ /\/\I l l\/\/(IV. 1 (V.)aromatic nucleus in the latter compound; ( c ) the existence ofperidiazo-oxides, such as (V), renders the quinonediazide configura-tion generally inapplicable.CoupZing.-K.H. Meyer20 holds the view that the coupling ofdiazonium salts with phenols or phenolic ethers is due to the addi-tion of the diazo-salt to a double bond or to the conjugate'd doublebond of the second component, whilst K. von Auwem and F.Michaelis21 suppose that the first stage is the addition of thediazo-salt to the oxygen atom of the hydroxyl o r alkyloxyl groupby reason of its residual affinity. P. Karrer22 now brings forwardcertain evidence to show that the addition of diazo-salts to aminestakes place a t the nitrogen atom. When diisoamylaniline iscoupled with sodium diazobenzene-psulphonate, an alkyl group iseliminated, and the monoalkyl derivative,C,H,,*NH C6H4*N:N*C6H,S0,Na,is obtained ; whereas dialkylanilines with small alkyl groups, suchas dimethylaniline, give the normal dialkylaminoazobenzeiie-sulphonates. Now, the1 heavy isoarnyl groups absorb more ofthe residual affinity of the nitrogen atom than the methylgroups ; consequently, in the former compounds certain affinities,marked in the formula given below, are strengthened as com-pared with t,hose in dimethylaniline.Accordingly, if Meyer's2o Ann. Report, 1914, 100. Ber., 1914, 47, 1275; A . , 1914, i, 744.Ibid., 1915, 48, 1398; A., i, 1073116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.view were correct, diisoamylaniline should couple more readilythan dimethylaniline, but this is not the case.It does not couplea t all until one of the alkyl groups has been eliminated. If,however, the addition takes place a t the nitrogen atom, the factsare readily explained; the diisoamyl groups absorb so much ofthe affinity of the nitrogen atom that addition of the diazoniumsalt is impossible until one of the alkyl groups has been eliminated.These and other considerations, such as the steric hindrance tocoupling observed with orthesubstituted amines or phenols, andthe existence of intermediate products of the type PhO*N:N*R,present astrong case f o r the view that coupling takes place by theaddition of the diazonium salt to the oxygen o r nitrogen atom ofphenols and amines, forming intermediate oxonium or ammoniumcompounds, which subsequently undergo intramolecular change.The mechanism of coupling has also been discussed by G.Charrier,23 who suggests that i t takes place according to thefollowing scheme :PhOH+ NiN(0H)Ph --f HO*C,H,*N:NH(OH)Ph+Binzonium Perha1oids.-F.D. Chattaway 24 records the fact thatammonium perhaloids, of which he has prepared two new examples,NH,Cl,I and NH,ClBrI, are readily soluble in water and lose two-thirds of their halogen when exposed to a vacuum over lime. Thediazonium perhaloids, on the other hand, are sparingly soluble inwater and stable when kept in a vacuum over lime. Contrastingthese properties of the two classes of substances, he finds supportf o r his view25 that diazonium trihaloids are not perhaloids a t all,but N-trihalogenohydrazines, R*NX*NX2.M. 0. Forster 26 criti-cises Chattaway’s conclusion, and A. Hantzsch 27 brings forwardevidence against it. The latter author points out that benzene-diazonium perbromide, NiNPhBr,, should be compared ratherwith phenyltrimethylammonium perbromide, PhMe,N*Br,, thanwith ammonium perbromides containing unsubstituted hydrogenatoms on the nitrogen atom. Phenyltrimethylammonium per-bromide, however, is sparingly soluble in water and stable whenexposed to a vacuum over lime, just like benzenediazonium per-bromide. The former can only have the formula PhMe3NBr,,and there is consequently no necessity to assume for benzene-diazonium perbromide, any formula other than NiNPhBr, toexplain the nature of its solubility and stability.Forster discusses the formation of phenylazoimide by the action23 Gazzetta, 1914, 44, ii, 503; A ., i, 66. 24 T., 1915,107, 105.25 Ann. Report, 1909, 97. 26 T., 1915,107, 260; A . , i, 181.27 Ber., 1915, 48, 1344; A., i, 1073.HO*C6H,*N:NPhORGANIC CHEMISTRY. 117of ammonia 011 benzenediazonium perbromide, and points out thatif the diazonium perbromides are to be regarded as N-tribromo-hydrazines, as Chattaway claims, there appears to be no altern-ative to the cyclic structure, Ph*N<g, for phenylazoimide. Thediazonium perhaloid representation, however, permits the explana-tion of the formation of phenylazoimide in two ways, as follows:N(1) NiNPhBr,Br,+NH3 -+ [KiNPh*N] -+PhN<# or PhN:NiN.(2) NiNPhBr+NH,Br + PhN:N*NHBr + PhNINiN.The second explanation depends on the production andmomentary existence of bromoamine giving rise to a diazobromo-amine which loses hydrogen bromide, owing to 6he excess ofammonia present.Evidence of the possibility of this explanationis afforded by the fact that the action of chloroamine on adiazonium salt yields a certain amount of the azoimide.Polycy clic A Toni a tic Hydro carbons.1ndene.-The methylene' group in indenel is capable of condensa-tion and alkylation. With benzaldehyde, benzylideneindene(phenylbenzofulvene) (I) is formed, and this on reduction yields3-benzylidene (11), of which the constitution follows from thefact that it can be condensed with benzaldehyde, forming benzyl-idenebenzylindene, and therefore contains a methylene group.When indene is alkylated by means of benzyl chloride and alkalii t also yields 3-benzylindene in the place of the expected l-benzyl-CH CH* CH*CH,Ph/\/\CH /\/\CH /\/\CH I 'C:CHPh I 1 IIC*CH,Ph I I "OH v- \/-- \/-(1.1 (11.1 (111)indene (111).To explain this and similar phenomena, Thiele28put forward the theory of the oscillation of the double linking inthe indene nucleus. C. C0urtot,2~ however, has now shown that inthis case and others both the 1- and 3-substituted indenes can beisolated, and there is therefore no necessity for Thiele's theory.It is the alkali used in the condensation of benzyl chloride withindene that is responsible for the change to the isomeric form.Thus, l-benzylindene can be prepared by the action of benzyl2a Ann.Report, 1906, 134.29 Compt. rend., 1916, 160, 523; A., i, 392118 ANNUAL REPORTS OK THE PROCIRESS OF CHEMISTRY.chloride on magnesium indene bromide, but alcoholic potassiumhydroxide converts it into 3-benzylindene. The 1- and S-benzyl-indenes differ in physical and also in chemical properties, the lattercombining with bromine to form an unstable compound whichalmost immediately loses hydrogen bro’mide, leaving benzylidene-indene, whilst the former gives a liquid ,dibromide which does notspontaneously lose hydrogen bromide, and when treated withpyridine only yields resinous products.FZuorene.-Dinaphthafluorene is obtained in a 60 per cent. yieldby the action of glacial phosphoric acid on di-a-naphthylcarbinolf o r one hour at 175O.3O Attention may also be drawn to the dis-covery31 that the red hydrocarbon, often formed as a by-productwhen condensations with fluorene are carried out in the presenceof sodium ethoxide, is a&bisdiphenylene-Aay-butadiene,A ~i,thmce~~e.-The constitution of the compounds obtained bythe action of mineral acids on liomopiperonyl and homoveratrylalcohols has now been established. These substances are derivativesof 2 : 3 : 6 : 7-tetrahydroxy-9 : 10-dihydroanthracene.Tetramethoxydihydroanthracene is, however, best prepared bythe condensation of veratrole with formaldehyde by means of60 per cent.sulphuric acid, when i t is obtained in a quantitativeyield. The dihydroanthracene ring suffers disruption when thiscompound is nitrated, 6 : 6/-dinitro-3 : 4 : 3’ : 4/-tetramethoxycliphenyl-methane being formed.32A method for the preparation of 9 : 10-diphenylanthracene is asfollows.o-Phthalaldehydic acid treated with magnesium phenylbromide in boiling anisole yields o-a-benzhydrylbenzhydrol,OH*CHPh*C,H,-CPh2*OH,which on boiling with hydrobromic acid gives 9 : 10-diphenyl-anthracene. This substance does not yield anthraquinone, buto-dibenzoylbenzene, on oxidation with chromic acid.33The oxidation of quinizarin (1 : 4-dihydroxyanthraquinone) in30 A. E. Tschitschihahin and 0. J. Magidson, J . pr. Chem., 1914, [ii], 90,31 W. Wislicenus, Ber., 1916, 48, 617; -4., i, 519.32 Mrs. G. M. Robinson, T., 1915,107, 267; A., i, 233.33 H. Simonis and P. Remmert, Ber., 1915,4$, 406; A., i, 136.1G8; A ., i, 23ORGANIC CHEMISTRY. 119hot benzene solution with lead dioxide leads to 1 : 4 : 9 : 10-anthradi-quinone, which has typical quinonoid properties. Attempts to pre-pare 1 : 4 : 5 : 8 : 9 : 10-anthratri-quinone from alizarin and 1 : 4 : 5 : 8-tetrahydroxyanthraquinonerespectively were unsuccessful.3~A cen~.~ht~,yleize.-Acenaphthylene polymerises under the in-fluence of light, giving a mixture of the two cis-fruits isomericheptacyclenes (I), both of which on reduction yield diace-naphthyl (IT).1 : 2 : 9 : 10-anthradiquinone and(1.1 (11.1Each heptacyclene yields two dibromo-derivatives, all of whichundergo oxidation quantitatively to a-bromonaphthalic anhydride,this fact indicating the formula: given below for the two dibromidesof each hydrocarbon.35Hydrocyclic Compounds a?.)zd Terpenes.Isomerisation of ring compounds usually proceeds in such amanner that cyclic compounds containing a side-chain are trans-formed into larger rings, whilst those without side-chains givesmaller rings with side-chains.Thus, cyclopentyl nitrite, preparedby the action of silver nitrite on cyclopentyl iodide, yields l-nitro-l-methylcyclobutane, amongst other products of the reaction, whentreated with concentrated alkali hydroxide solution,7H2'CH2>CH-N0, CH,*CH, + CH,<E~2>CYe-N0,,2whilst iodomethylcyclopentane yields with silver nitrite principallyl-nitro-l-methylcyclopentane with some o-nitromethylcyclopentaneand traces of nitrocyclohexane. The isomerisation of a five- to asix-membered ring is also illustrated by the formation of cyclo-hexene from cyclopentylcarbinol by the action of oxalic acid.3634 R.Lesser, Ber., 1914, 47, 2526; A., i, 420.35 K. Dziewonski and C. Paschalski, ibid., 1913, 4& 1986; 1914, 47, 2680;36 N. A. Rosanov, J . Russ. Phys. Chem. Soc., 1915, 47, 591; A . , i, 657.A., 1913, i, 847; 1915, i, 229120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The iodohydrin of cyclohexanediol when treated with silvernitrate yields ~ycZopentanal~~7 but the reaction takes a differentcourse with certain homologues of the iodohydrin. Thus, 2-iodo-l-phenyl-4-met,hylcyclohexan-1-01 (I) yields l-phenyl-3-methylcyclo-hexan-6-one (111), l-phenyl-5-methyl-~~-cycZohexen-2-01 (11) beingformed as an intermediate product.38Ph>C<CHT.CH2>CKMe -+ HO*C<CPh*CH2>CHMe CH,*CH, + OH CH, *CH2(1.1 (11.)C O < ~ ~ ~ ~ * ~ ~ ~ > C H M ~ CH2---C H(111. )Cyclic a-chloroketones are converted on treatment with alcoholicpotassium hydroxide into cyclic acids with the number of carbonatoms in the ring diminished by one. Thus, 2-chlorocyclohexanoneyields cyclopentanecarboxylic acid. The carboxyl group is alwaysfound a t the carbon atom to which the chlorine atom is united inthe chloroketone, and thO following scheme may represent thechange : 39c."CC*C*C(OH), c* c* C( OH) C * i >O + ,>CH*CO,H. q*c*~'lcl ~ Q*C*SH--Two interesting researches carried out in each case to .determinethe position of an unsaturated linking may be noted.It has beenfound that l-benzylcyclohexan-1-01 and phenylcyclohexylcarbinolyield the same hydrocarbon on dehydration. The specific refrac-tion of this substance favours the view that it has the configura-tion of 1-benzyl-Ax-cyclohexene (I) and not of benzylidenecyclo-hexane (11), which contains a conjugated double linking. Chemicalevidence to the same end has now been adduced. The nitroso-chloride of the hydrocarbon was converted into the oxime. Thiswas hydrolysed to the ketone and the latter reduced. l-Benzyl-Al-cyclohexene should yield l-benzylcyclohexan-2-one by this treat-ment :37 M. Tiffeneau, Compt. rend., 1914,159, 771; A., i, 12.38 M. Le Brazidec, ibid., 774; A., i, 12.39 A. Favorski and V. Boshovski, J . Buss.Phys. Chem. SOC., 1914, 46,1097; A , , i, 411ORGANIC CHEMISTRY. 121whilst beiizylidenecyclohexane should yield benzoylcyclohexane,CPh (: NOH)-CCl<cHz. H2° CH2 CH2> CIT2 + COP h CH<CH2. CH2* c H2> c 2.Actually, the final product is not identical with benzoylcyclo-hexane, and is therefore assumed to b0 l-benzylcycZohexan-2-0ne.~~The reduction of 1 : 3-dimethyld3-cycZol~exenylidene-5-acetic acid(111) might le'ad either to 1 : 3-dimetl~yl-A4-cycZohexenyl-5-acetic acid(IV) if the substance behaves as an aBy8-unsaturated acid or tothe A3-acid (V) if the semicyclic linking becomes reduced beforethe endocyclic linking. It has now been shown that reduction(111.)leads t o the acid (IV).41The oxidation of alicyclic carbinols and aldehydes with nitricacid leads to the formation of dibasic fatty acids with the samenumber of carbon atoms in the molecule as were contained in thering ; thus, cycZohexylcarbino1 and cycloliexanealdehyde yieldadipic acid.The alicyclic acids, however, in this case cyclohexane-carboxylic acid, are practically unattacked by nitric acid, andcannot therefore be regarded as intermediate products in thedegradation of the carbinols and aldehydes.42The action of dilute nitric acid on the three bicyclic hydro-carbons camphane (I), camphenilane (11), and isocamphane (111)has been studied.43 Camphane yields a mixture of a- and a'-nitro-40 K. von Auwers and W. Treppmann, Ber., 1915,4$, 1207 ; A., i, 789.41 K. von Auwers and W. Treppmann, ibid., 1377 ; A., i, 1058.42 S.S. Nametkin and Mlle. A. K. Rushenceva, J . Russ. Phys. Chem. SOC.4a S. S. Nametkin and collaborators, ibid., 1915, 47, 405, 409, 414, 425:1914, 46, 1540; &4., i, 513.A., i, 698, 699, 700, 701122 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.caniphane and camphoric acid. Camphenilane yields /3-nitro-camphenilane, P-isocamphenilone (W), and 4 : 4-dimethylcyclo-C H,. 7 H--OH, CNe,*$l H-C H, CMr,--F] E--CH,C H Me CH--C H, C H2* CBle-- C: H, I QA2 I I p e 2 1 I T H 2 1 CH,--CH--C: H,(1.1 (11.1 (111.)C M P , * ~ H--CO C Jle,*~H*CO,HCH,--CH*CO,H CH,-CH--CH, I YH2 I QH2 I(IV.) (V.)pentane-1 : 3-dicarboxylic acid (V). isocamphane yields a mixtureof stereoisomeric nitrecompounds, which on oxidation with per-manganate gives two isomeric ketones, termed isocamphones.These are probably /3- and /3'-isocamphones, having the formulaC31e2*7 K-CO C Me, 7 E-COH I 7 " 2 I Me I QH2 I H>C-CK-CH, 3fe>C-CH--C:H,aDehydrocamphenic acid (VI) yields on oxidation with nitric acidlactone-dicarboxylic acid, C9HIPOG, for which several differentformulze have been proposed (0.Aschan, W. N. Haworth, andA. T. King44 P. Lipp,*5). P. Lipp46 has now synthesised thelactonic acid and a stereoiso'meride by the action of bromine onisocamphoronic acid (VIII), and thus confirmed the formula (VII)which he assigned t o it previously.CH,*? H*CXe,*CO,H GI€,-? H--?Xe2 CH,--C]H-C]Me,+ I $!H*O*CO +- 1 YH, C0,HC0,H CO,H C0,H C0,H(VJ. 1 (VII.) (VIII. )Distillation of oximinocamphor (I) with phosphorus penta-chloride leads to cyanolauronyl chloride (11), but a portion of thiscompound suffers loss of carbon monoxide and hydrogen chloridein the course of the reaction and passes into camphoceenonitrileCH,*F H-C:NOR CH,*y 13-CN CH,* vH* CN I ?Me, I + 1 $Me, + I ?Me2CH2*CMe- CO CH,*CMe COCl CH=CMeI F H 2CH=C*CO,H(11947(1.1 (11.) (111.)4* Ann. Report, 1912, 149; 1913, 119.45 Ibid., 1914, 119; Ber., 1914, 47, 871; A., 1914, i, 542.46 Ibid., 2994; A,, i, 553.47 W. Borscho and W. Sander, ibid., 1916,4.8, 117 ; A., i, 148ORGANIC CHEMISTRY. 123Several papers have appeared on the autoxidation of terpenes.Limonene (IV)48 gives a mixture of products, amongst which arefound carvone and carveol (V). Ths lat'ter substance had notpreviously been prepared in a pure skte.(IV.>CH,:CMe=CH<CH:--CHd CH *CH(OH)) CMe(V.)Pulegone (VI) yields acetone, /3-methyladipic acid, and a keto-lactone, which probably has the constitution (VII),49 whilst(VII.)citronellaldehyde 5O gives a large number of degradation products.The Orgaizic Con~pounds of Seletiium.Several new methods for the introduction of seleniuin into thenucleus of aromatic compounds have been described in the lastfew years.The most important is an adapbation of the methodsof Sandmeyer and Gattermann. Potassium selenocyanate is added toa solution of a diazonium salt which has been neutralised bu Congo-red paper by means of sodium acetate. The aryl selenocyanate,R*SeCN, thus formed is readily converted by means of alkali intotlie selenol, R-SeH, which becomes spontaneously oxidised in theair to the diaryl diselenide, RSe.SeR.51 Somewhat similar is thepreparation of a mixture of diaryl diselenide, R2Se2, and diarylselenide, R2Se, by the action of potassium diselenide, K2Se2, ondiazonium salts.52 Compounds with a labile halogen atom, such aso-chloronitrobenzene, react with sodium hydrogen selenide 53 orpotrassium selenocyanate 5.1 to give aryl selenols or aryl seleno-cyanates.Selenium and its chlorides combine with diphenylamineon heating to give selenodiphenylamine.5548 A. Blummn and 0. Zeitschel, Ber., 1914,47, 2623; A., i, 426.49 E. Sernagiotto, Atti R. Accad. Lincei, 1915, [v], 24, i, 1065; A., i, 826.6o E. Sernegiotto, ibid., 850; A., i, 889.51 H.Bauer, Ber., 1913, 4-43, 92; A , , 1913, i, 263; G. T. Morgan and 3. C.52 R. Lesser and R. Weiss, ibid., 1912, 45, 1835; 1913,46, 2640; 1914, 47,s3 H. Bauer, Eoc. cit.64 E. Fromm and K. Martin, Annulen, 1913, 4.01, 177; A., 1913, i, 1323.65 C. Weizmann and H. Stephens, P . . 1913, 29, 196; W. Cornelius, J . pr.Elliot, P., 1914, 30, 248.2292, 2505; A., 1912, i, 642; 1913, i, 1184; 1914, i, 1083; 1915, i, 404.Chern., 1913, [ii],SS, 395; A., 1913, i, 1090124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Selenic acid reacts with benzene and toluene to. give arylseleniousacids, in the latter case ortho- and para-substituted derivativesbeing formed,56 but aniline selenate does not yield paminophenyl-selenious acid on heating in the same way that aniline sulphateand arsenate yield sulphanilic and arsanilic acids,57 f o r the acid isreduced to selenium.The action of Grignard’s reagent on the chlorides of seleniumhas given interesting results.It was shown sorLe years ago158 thatelementary sulphur o r selenium readily react with this reagent,giving thiophenol and diphenyl disulphide, or ths correspondingselenium analogues. Incidentally, i t may be remarked that this is avery convenient method for the preparation of diphenyl diselenide.Sulphur chloride also yields the disulphides with magnesium phenylor benzyl haloids, whilst thionyl chloride gives the sulphoxides withthe same reage11ts.5~ Selenium dichloride, however, whilst yieldingwith magnesium phenyl bromide the normal product diphenyldiselenide together with some diphenyl aelenide, behaves abnorni-ally with magnesium benzyl chloride, giving besides the normalproduct, dibenzyl diselenide, a considerable quantity of dibenzylselenodichloride, Se( CiHi),Cl,.This product presumably resultsfrom the decomposition of selenium dichloride, into seleniumand selenium tetrachloride, for the latter compound yields thesame product with magnesium benzyl chloride. The productsobtained from selenyl chloride are not analogous to those preparedfrom thionyl chloride, f o r they do not contain oxygen; magnesiumphenyl bromide gives diphenyl selenide, and magnesium benzylchloride gives dibenzyl selenodichloride.6° The action of seleniumbromide on magnesium alkyl and aryl haloids bas also beenstudied.61The Orgunic Compounds of Arsenic.The development of this branch of organic chemistry down t othe preparation of salvarsan, 4 : 4’-dihydroxy-3 : 3’-diaminoarseno-benzene dihydrochloride, was ably reviewed in the Annual Reportsfor 1911.Since then the importance of salvarsan as a remedy forsyphilis has led to an enormous amount of work on aromatic arsenic56 H. W. Doughty, Arner. Chem. J., 1909, 41, 326; H. W. Doughty andF. R. Elder, Eighth Inter. Cong. App. Chem., 1912, 6 , 93; A., 1909, i, 296;1913, i, 962.57 F. L. Pyman, P., 1914, 30, 302.58 H. Wuyts and G. Cosyns, Bull. SOC. chim., 1903, [iii], 29,689; F. Taboury,ibid., 1903, [iii], 29, 761; 1906, [iii], 35, 668; A , , 1903, i, 686, 748; 1906, i, 834.59 W.Strecker, Ber., 1910,43, 1131; A . , 1910, i, 532.60 W. Strecker and A. Willing, ibid., 1915, 4$, 196; A., i, 238.61 A. Pieroni and C. Coli, #azzetta, 1914, 44, ii, 340; A. Pieroni andG. Balduzzi, ibid., 1915, 45, ii, 106; A., 1914, i, 1198; 1915, i, 956ORGAKIC CHEMISTRY. 125compounds. Salvarsan is chiefly administered by intravenousinjection, and for this purpose the aqueous solution of the salt,which is strongly acid, has to be mixed with sufficient sodiumhydroxide to neutralise the hydrochloric acid and redissolve theinsoluble base as phenoxide. This procedure, which requires careand skill to give a sterile solution, is undertaken unwillingly bymany medical men, and in any case gives an alkaline solution.Many attempts have therefore been made t o supersede salvarsanby some derivative that would be immediately soluble in water,giving a neutral solution, and equally efficacious in the treatmentof disease.This work led to the preparation of many simplederivatives of salvarsan, such as neosalvarsan, a condensation pro-duct of salvarsan with sodium formaldehydesulphoxylate, in whichoae of the amino-groups of the original product becomes*NH-CH,*SO,Na. It is readily soluble in water and neutral, butopinions differ as to its therapeutic value compared with salvarsan.A great number of substituted arsenobenzenes, many of themsubstituted salvarsans, have been prepared during the period underreview (1912-1915), but none has been found to be an improve-ment on this substance.Amongst the substituted salvarsans we may note the N-dimethyland N-tetramethyl derivatives, which are ten times as toxic assalvarsan ; and the N-hexamethyldiammonium salts, which arethree to five times as toxiq62 5 : 5/-diaminosalvarsan and its di-o-methyl ether,63 a stilbene derivative of salvarsan G4 (I),OH OH OH CIH(1.1 (11.)6 : 6/-dihydroxysalvarsan, and 5 : 5’-diamino-6 : 6/-dihydroxysalvarsan(11), which have an augmented toxicity but no correspondingtherapeutic value,65 and the two isomeric 5 : 5’- and 6 : 6l-dicarb-oxylic acids derived from salvarsan.66An important new general method for the synthesis of aromaticarsinic acids is the replacement of the amino-group of an aromaticamine by -AsO(OH),.This operation is easily carried out by add-ing the diazotised solution of the amine to a solution of sodiumP2 A.Bertheim, Ber., 1912, 45, 2130; A . , i, 818.63 P. Karrer, i b i d . , 1914,47, 2275; A., 1914, i, 1100.64 P. Karrer, ibid., 1915,418, 305; A., i, 333.155 H. Bauer, ibid., 509; A., i, 606.66 P. Karrer, ibid., 1058; A., i, 855126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.arsenite and heating the mixture with sodium hydroxide.yield is about 30 per cent. of the theoretical.67TheR*N,Cl + (NaO)3As -+ RAsO(ONa)2.Another new method for the introduction of arsenic into thepara-position of a substituted benzene derivative is announced.Benzene derivatives are readily converted into chloromercuri-compounds, R*HgCl, in which the chloromercuri-group occupies aposition para to that of the substituent in the benzene nucleus,and it has now been found that the chloromercuri-compoundsreadily yield dichloroarsines when heated with arsenic trichloride.R*HgCl+ AsCl, = HgCl, + R*AsCl,.The reaction is surprising, since the similarly constituted mag-nesium alkyl haloids give only tertiary arsines with arsenic tri-chloride.68A change in the reverse direction is effected by treating aromaticcompounds containing tervalent arsenic with mercuri-salts inaqueous solution, when mercury diaryls and arwnious acid aref ormed.69Other important new methods in this field are as follows.The reduction of an equimolecular mixture of two aromaticarsinic acids, R*AsO(OH), and R'ASO(OH)~, leads to the forma-tion of an asymmetrical arsenobenzene, R-As:As*R1.70 Hypo-phosphorous acid is a specific reducing agent for the arsinic acidgroup, 50 that aromatic arsinic acids containing a nitro- or azo-group can be reduced by this acid to arsenobenzenes still contain-ing these groups.71 The reduction of aromatic arsinic acids withmetals and mineral acids leads to the arsines, R*AsH,,72 which maybe condensed with (a) arylarsenious oxides or haloids to givearsenobenzenes : 73R*AsH2 + OAsR1 + R*As:As*R1,or ( b ) with antimony trichloride, substituted stibine dichlorides, orbismuth trichloride to give the compounds R*As:SbCl, R-As:Sb*R,and R*As:BiCl respectively.74Aromatic arsine dichlorides, R*AsCl,, combine with phosphorus,67 H.Bart, D.R.-P., 250264; A , , 1913, i, 115.68 G.Roeder and N. Blasi, Ber., 1914,47, 2748; A., i, 331.69 D.R.-P., 272289; A., i, 34.70 D.R.-P., 251104; A., 1913, i, 116.7 1 P. Karrer, Ber., 1914, 47, 2275; A., 1914, i, 1100.72 D.R.-P., 251571; A., 1913, i, 117.74 P. Ehrlich and P. Karrer, Ber., 1913, 40, 3564; A., 1914, i, 99.73 D.R.-P., 254187; A., 1913, i, 416ORGANIC CHEMISTRY. 127arsenic, antimony, selenium, and tellurium liydrides, f orniingcondensation products, such as, in the last case,H C1,NH2* C6H,*AsTe.75Arsenobenzenes also yield additive compounds with the salts ofthe noble metals.76The methylation of arsenobenzenes and arylarsenious oxidesleads to interesting results. The former suffer fission when heatedwith methyl iodide, giving an arylarsonium iodide and an aryl-arsine di-iodide??R*As:As*R + 3MeI = R*AsMe,I + R-Ad,.Aromatic arsenious oxides combine with alkyl haloids in thepresence of alkali, yielding arylalkylarsinic acids, which on reduc-tion yield diaryldialkyldiarsines,Ph*As(ONa)2 + Me1 = Ph*AsMeO*ONa + NaI -+PhMeAs- AsMePh.4 : 4’-Dihydroxy-3 : 3’-diaminodiphenyldimethyldiarc;ine has beenmade in this way; it is closely related to salvarsan, but its toxicityis greater and its therapeutic action less.78The Organic Conipozinds of Antimony.The antimony analogue of salvarsan has been prepared bymethods similar to those used for salvarsan.Monoacetyl-p-phenylenediamine is diazotised and mixed with sodium antimonite,yielding pacetylaminostibinic acid. This is nitrated and the pro-duct hydrolysed, when 3-nitro-4-hydroxyphenyl-l-stibinic acid isformed.Reduction of the nitro-acid with sodium hyposulphitermults in the formation of 4 : 4’-dihydroxy-3 : S’-diaminostibino-benzene.79FRANK LEE PYMAN.75 D.R.-P., 269699; A . , 1914, i, 609.713 D.R.-P., 268220, 268221; P. Ehrlich and P. Karrer, Ber., 1915, 48,1634; A., 1914, i, 345; 1916, i, 95.77 A. Bertheim ibid., 1914, 47, 271; A., i, 344.A. Bertheim, ibid., 1915, 4$, 350; A., i, 331.7s D.R.-P., 254421, 259875, 268451; A., 1913, i, 416, 1122; 1914, i, 21G128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.PART 111.-HETEROCYCLI c DIVI s ION.LAST year the outbreak of the war rendered it impossible to surveythe contents of the German and Austrian journals beyond July,so that in the present Report it has been considered advisable t odeal with certain papers which in point of date actually belong toan earlier volume.I n this way it is hoped that the Report,although technically incorrect in its title, will nevertheless serve amore useful purpose than it would have done had the materialsstanding over from last year been omitted entirely from the review.It must be admitted that, even with this addition, the materialwhich the writer had a t his disposal is not of a character thatlends itself to interesting treatment. It is true that the chemistryof the anthocyanins has progressed very rapidly since the lastAnnual Report was published, but the development in this fieldhas been largely a matter of steady progress in detail rather thanan advance in main principles; and as a result, although the newknowledge thus gained is of the greatest importance, it does notconduce to the production of a readable narrative.The chemistry of chlorophyll had already begun to show adecline in the period covered by last year’s Report, and sinceWillstatter has turned his energies in another direction it isunlikely that we shall see i n the immediate future any further flowof connected researches like those which were published in thelast five years.Investigation is going on, but it is improbable thati t will be conducted on the same gigantic scale.The pigments of the blood and ot the bile still furnish a steadystream of contributions to our knowledge, although it must beadmitted that the difficulties of following the trend of discoveryin this line are greatly increased by two factors, namely, the con-tinual changing of nomenclature and the violent polemics inwhich the various investigators indulge.The subject is one ofintense difficulty, both on the experimental side and in the deduc-tion of probable conclusions from the multitude of perplexing datawhich are brought to light, and it seems regrettable that investi-gators who are engaged in such laborious and important researchescannot avoid the waste of time and energy which these contro-versies enhail both on their authors and on those who are followingtheir wosk.Our knowledge of the alkaloids has not increased much on thetheoretical side during the current year, but a vast amount ofinformation is being accumulated with regard to new and littleknown compounds of this class.This side of the subject appearORGANIC CHEMISTRY. 129t o have taken a fresh lease of life, and numerous investigators areturning their attention to it.Compounds containing a pyrone nucleus have attracted a con-siderable amount of attention during the period under review, andin this region of the subject there seems to be considerable scopef o r work along the lines which have been st.ruck out by variousworkers.Some new heterocyclic compounds have been synthesised inwhich atoms of silicon, arsenic, and titanium are present asmembers of the rings. Among the nitrogen compounds, also, con-siderable advances in our knowledge 'have been made, and thesynthesis of silver pentazole, although strictly speaking it belongsrather to inorganic than to organic chemistry, has furnished uswith a most remarkable example of the aptitude with whichnitrogen atoms lend themselves to the formation of cyclic com-pounds.Apart from these subjects, there is, of course, a vast amount ofmaterial which a Reporter cannot utilise owing tp the exigenciesof space; and a general survey of the papers published shows thatthere is no sign of the heterocyclic section of organic chemistryfailing in its attraction for numerous workers.Some New Heterocyclic Types.The chemistry of the heterocyclic compounds has of recent yearstended more and more towards the building up of extremely com-plex rings, and it is rather a relief to find that this year one ortwo substances of much simpler character have furnished materialsfor research.Of these, the most interesting is a cyclic compoundwhich contains a silicon atom among the members of the ring.Hitherto, cyclic silicon compounds have not been very closelyexamined. Some have been obtained1 by the action of sodium ona mixture of silicon tetrachloride and trimethylene bromide (oro-dichlorobenzene), but the compounds resulting from this reactionwere of a somewhat indefinite nature. The application of theGrignard reagent has led t o the synthesis of more satisfactory sub-stances,2 and the heterocyclic chemistry of silicon seems to be onthe verge of an interesting advance.When a Grignard reagent obtained from as-dibromopentane isallowed to react with silicon tetrachloride, cyclopentamet.hylene-Hart, Brit.Assoc. Rep., 1887, 661.A. Bygdh, Ber., 1915, 48, 1236; A . , i, 912.REP. -VOL. XII. 130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.silicon dichloride (I) is produced, which is hydrolysed by water toform a polymeride of cyclopentamethylenesilicone (11). Whendimethylsilicon dichloride is substituted for silicon tetrachloridein the first reaction, the end-product contains the methyl groupsin place of the two chlorine atoms of formula I, and has beentermed dimethylcyclopentamethylenesilicane.The preparation of a simple six-membered selenium derivativeof the heterocyclic series has been undertaken3 with the object oft2sting the properties of the new substance from the point of viewof a dye, and also, ultimately, as a drug in the treatment oftrypanosomiasis.In neither respect has the compound been satis-factory, so that its chief interest is purely chemical. The outlineof the method employed to prepare it is as follows. pp’-Diamino-diphenylmethane is acetylated, nitrated, and reduced. The result-ing od-diamino-&-diacetyldiaminomethane is diazotised and thentreated with potassium selenoselenate. By means of concentratedsulphuric acid the acetyl radicles are eliminated, and the end-product of the reaction is found to be 3 : 6-diaminoselenopyronine,which is isolated in the form of its chloride:CHRather more complex than this is a substance which was origin-ally supposed to be benzophenoneselenone, but has now been shownto’ be a dilacbonel4 derived from a hypohhetical diphenylselenoxide,di-o-carboxylic acid or from the corresponding dihyaroxy-com-pound, C02H*~6H4*Se(OH),*C6H4*C0,H.The structure of thedilactone appears now to be established asso that it is an example of a heterocyclic substance somewhat akinin type to the spirans. Various derivatives of selenoxanthone-(1.1 (11.)carboxylic acid (I) have also been examined, and selenoxanthoneitself (11) has been obtained by heating the acid with lime.The pharmacological value of arsenic has led, in recent years, toa very careful study of the arsenic derivatives, and in the presentP. Ehrlich and H. Bauer, Ber., 1915, 4$, 502; A . , i, 579.4 R.Lesser and R. Weiss, ibid., 1914, 47, 2510; A . , i, 445ORGANIC CREMISTRY. 131year a new type of heterocyclic derivative has been obtained5which contains two arsenic atoms in the ring. By acting on5-nitro-2-methylphenylarsinic acid with so,dium hydroxide, dyes areobtained which, when reduced in alkaline solution, yield5 : 5’-diamino-2 : 2’-stilbenediarsinic acid, and from this compound,by means of hyposulphite, i t is possible to produce 5 : 5’-diamino-I : 1’-arseno-2 : 2’-stilbene :Derivatives of this substance have been prepared, but the physio-logical result of their action is apparently disappointing.One or two titanium derivatives6 might be regarded as comingwithin the limits of this section of the subject. When tita,niurntetrachloride is treated with various organic acids, compounds areproduced which apparently contain a titanium atom as a memberof a ring.Thus, when salicylic acid reacts with titanium tetra-chloride, a compound is formed which, when treated with pyridinein alcoholic solution, produces a salt, formulated by Rosenheimthus :Salicylic acid plays a part in the formation of another hetero-cyclic substance the ring of which contains a metallic atom.’When sodium p-methoxybenzoate reacts in aqueous solution witha mercuric salt, the corresponding mercury salt is produced, whichappears to have the structure (OMe-C,H,*CO,),Hg. On boilingwith water, this substance is converted into a new compoundwhich does not show any of the ordinary reactions of mercury, andits formula is therefore supposed to be I.Since this substanceis produced without the intervention of any hydroxyl radicle (thehydroxyl of the acid being methylated), and since a perfectlyanalogous reaction occurs when salicylic acid itself is employedinstead of its methyl ether, it seems reasonable to assume that thesubstance derived from salicylic acid has the structure shownin 11.Rather more complex than any of the foregoing is the new sub-s P. Karrer, Ber., 1915, 48, 305; A., i, 333.‘I H. Lajoux, J . Pharm. Chim., 1915, [vii], 11, 279; -4., i, 537.* R. Stoermer and E. Barthelmes, Ber., 1915, 48, 502; A . , i, 152.A. Rosenheim, ibid., 447; A., i, 537.F . 132 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.stance coumarinoline, which is produced by the reduction ofo-nitrobenzylidenecoumarone with sodium hyposulphite in aqueous-alcoholic solution.The reduction leads Lo the formation of thecorresponding amino-derivative, but this a t once undergoes iiitra-molecular rearrangement, with the formation of the substancewhich has received t,he name coumarinoline, o,n account of itskinship with quindoline and thioquindoline.Some Dericatives of Hydrazincetic Acid.It will be remembered that ethyl diazoacetate and ethylfumarate interact with the formation of the triethyl ester ofpyrazolinetricarboxylic acid, and that the latter compound, whenheated, evolves nitrogen and yields ethyl trimethylenetricarb-oxylate :NCO,Et*CB:CH*CO,Et + $j.>CHaCO,Et =C0,E t *CH* CH*CO,E t>CH,*CO,Et = N, + \/ C0,Et.G CH(C0,Et)NH CH*CO,EtN---An analogous reaction has been obswved when ethyl fumarateis replaced by ethyl azodicarboxylate,g but in this case the firstproduct is a heterocyclic compound containing four nitrogen atomsin 'Its nucleus, whilst the end-product of the reaction is a derivativeof the true hydraziacetic acid :C0,Et.N NI I + II>CH*CO,R = C0,Et.N NCO,Et*r-y H*CO,EtC0,Et.N NN\/CO,Et-NI >CH*CO,Et + N,C0,Et-NThis reaction takes place in alcoholic solution; but if the tworeagents be permitted to interact without any diluent, and if, a tthe same time, the reaction temperahre does not exceed 120°, atotally different product is obtained.This new compound has thecomposition C5R9O3N3, and when it is hydrolysed it yields hydr-azine, ammonia, and glyoxylic acid. One possible formula for sucha substance is NH,.CO*CI3[:N*NH*CO,Et, and when a compoundof this structure was synthesised its properties were found to beidentical with those of the product obtained from ethyl diazo-E.Muller, Ber., 1914, 47, 3001; A., i, 509ORGANIC CHEMISTRY. 133acetate and ethyl azodicarboxylate, so that the constitution isdefinitely established.A variation was introduced into the procedure by replacing theethyl azodicarboxylate by azodicarbonamide, with the object ofpreparing an amide of hydrazimethanetricarboxylic acid ; but thismethod did not yield the results which had been expected. Theend-product of the reaction was found to be isomeric with thecompound obtained in the previous case, but its hydrolysis productsare differeat.When treated with concentrated hydrochloric acid ina sealed tube, it yie'lded alcohol, carbon dioxide, ammonia, hydr-azine, and glyoxylic acid ; hydrolysis with dilute sulphuric acidgave rise to the semicarbazone of glyoxylic acid, and when thesubstance was merely boiled with water, it yielde'd the semicarb-azone of ethyl glyoxylate. From these data i t seems probable thatthe conipound has either of the structures shown below, the right-hand one being the more probable of the two:YH-7 H*CO,Et F]O-NH,CO NHNHN-- \/ A~>CH*CO,E~ 'Azodibenzoyl, when treated with ethyl diazoacetah, yields as theend-products of the reaction ethyl dibenzoylhydraziacetafe,TBzNBzMuch more complicated is the substance which results when1 : 2 : 4 : 5-betrazine is treated with diazomethane.Here threemolecules of diazomethane react, and three molecules of nitrogenare eliminated with the final formation of trimethylenetetrazine :>CH*CO,Et, and a small quantity of tribenzoylhydrazine.CH,N-N/\which, on hydrolysis with dilute sulphuric acid, decomposes intof ormaldehyds and hydrazine.9 zoirnide and its Derivatives.The action of azoimide on pbenzoquinonelo appears to be muchmore compJicated than might have been expected a t first sight.The earliest stage seems to be the attachment of the azoimidenucleus to the quinone nucleus, followed by the reattachment of10 E. Oliveri-MandalB and. E. Calderaro, Gazzetta, 1915, 45, 307 ; A., i, 909 ;E.Oliveri-MandaIiL, ibid., ii, 120; A., i, 1013134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the two hydrogen atoms (one from the azoimide and one from thequinone nucleus) to the oxygen atoms of the quinone:O:C,H,:O + N3H =HO*C,H,N,*OH.The second stage consists of an interaction between the new com-pound and a second molecule of p-benzoquinone, which becomesreduced to quinol:HO*C,H,N3*OH + O:CGH,:O = O:C,H,N,:O + HO*C,H,*OH.The quinol then attacks a third molecule of pbenzoquinone t o formquinhydrone. The fourth stage in the reaction is furnished by aninteraction between this quinhydrone and a second molecule ofazoimide which produces quinol and the compound HO*C,H,N,*OH.A fifth reaction occurs between quinol and the compoundO:CGH,N,:O, with the formation of pbenzoquinone andHO*C,H,N,*OH.Thus the end-products of the series of reactions are quinhydroneand the azide of quinol.Triazoquinol, HO*CGH,N,*OH, is quite stable towards shock, butexplodes violently when heated.When heabd with aqueous alcoholor treated with cold acid or alkali, it yields nitrogen and azoimide.With ammonia solution, it gives a green coloration, which changesto red, nitrogen being evolved.The Thiophen Group.When ethyl B-aminocrotonate is allowed t o react with chloro-acetyl chloride it forms ethyl B-amino-a-chloroacetyl crotmate, andit has now been found that the action of potassium hydrosulphideon this ester yields a hydroxythiophen derivative.NH,*CMe:C(CO,Et)*C'O*CH,Cl+ KHS +CMe:Q'CO,EtNH,*CMe:C(CO,Et)*CO*C H,*SH -+ S<cH =c.OH + NH,.The hydrogen atom in the position 2 is very reactive, and in con-sequence of this the substance has been found capable of under-going various condensations. Thus, in the presence of concen-trated hydrochloric acid two molecules of the ester take part in areaction which leads t o the formation of ethyl 3-hydroxy-5 : 5'-di-methylbis-2 : 3/-thiophen-4 : 4'-dicarboxylate (I) :CO,Et*E-g*OH C0,Et y:CMe CO,Et*~--~-O-CO*y:CMeMoC C- C=CH >' RIeC C---- C-CH >s'\/S\/S(1.1 (11.ORGANIC CHEMISTRY. 135The corresponding acid yields a lactone of the structure 11, andwhen this lactone is distilled with lime the lactone o,f a new acidis produced, which has tlhe structure\/SThe original ester reacts with formaldehyde, giving a conipound ofthe type (A), whilst benzaldehyde yields an analogous substance.With phenylhydrazine a phenylhydrazino-derivative is produced,which undergoes condensation in the presence of warm acetic acid :Further reactions of the substance are described in the originalpaper.11CO,Et-g--g*NH *N H P h C0,ED: $--g-N H-/\MeC CH + MeC C--- 0 \/S\/S(A*)The action of phthalic anhydride on thiophen in the presence ofaluminium chloride leads to the production of o-2-thienoylbenzoicacid,l2 C,H3S*CO*C6H,*C0,H.This substance forms two isomericesters, f o r in addition to the ethylation of the carboxyl group inthe normal manner a second type of reaction leads to the produc-tion of a $-ester having the structure 111.The $-ester reacts withC,H,S-C( OE t)<--'-)CO(111.)c6H4alcoholic ammonia to form the corresponding $-amide, but thenormal ester does not appear to react with ammonia a t all. Withhydroxylarnine hydrochloride and aqueous potassium hydroxideo-thienoylbenzoic acid yields an anhydro-oxime which has thestructure IV, whilst thiophenanthraquinone can be obtained fromthe acid by the action of phosphoric oxide o r concentratedsulphuric acid.Some further study of the thianthren group has been made, butthe results are such as to make reference t o the original necessary.13Some GoiLdensntioit Reactions of o-Thiolbenzoic Acid.Coinpounds containing the keto-methylene group lend themselveswith readiness to certain types of reaction, and during the presentl1 E.Benary and A. Baravian, Ber., 1915,48, 593; A . , i, 576.l2 W. Steinkopf, Annalen, 1914, 4Q7, 94; A., i, 155.l3 K. Fries and E. Engelbertz, ibid., 194; A . , i, 155136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.year a fresh field has been opened in this section of the subject.14It will be recalled that o-thiolbenzoic acid has already been foundsusceptible to many condensation reactions, such as that whichleads to the formation of thioxanthone :C6H4<i2H + c6H,5 -k 0 = CtiH,<-c~>c,H, -k 2H20.Further investigations have nosw been made, in which aliphaticderivatives are substituted f o r the aromatic compounds, and theresults may be expressed concisely in the following equations:c6H,<!0>cH2 + H20 + CO, + CH,*CO,HC,K4<~~>C€Iz + 2CH,*C02HI n the case of the second reaction another product is usuallyformed along with 3-oxy(l)thionaphthen, as the reaction mayproceed further, as indicated by the formulz below:/\-c/\co i I I + H,O + EtOH\/\P\/CHCH3With o-tliiolbenzoic acid, dibenzoylmethane yields 2 : 2-dibenzoyl-S-oxy( 1) thionaphthen (I), whilst benzoylacetone produces 2-benzoyl-3-oxy( 1)thionaphthen (11), the latter of which can readily beconverted into " thioindigo " :C6H4<:6>CBz2 C6H4<-F>CH(1.) (11. )Analogous condensations hake place between o-thiolbenzoic acidand other ketomethylene derivatives, but the course of the reactionis not always so simple as those shown above.l4 S.Smiles and R. N. Ghosh, T., 1915, 107, 1377OKGANlC CHEMISTRY. 13'7Pyrrole and its Allies.A considerable amount of work has been carried out on thepyrrole group during the period under review, and some of i tappears worthy of notice. It is well known that pyrrole deriv-atives under certain conditions are peculiarly liable to undergointramolecular rearrangement, and any investigations which throwlight on this point are of value. The reactions of the metallicderivatives of pyrrole are rendered somewhat obscure owing to thefact that our knowledge of their exact mode of reaction is stillrather vague, and the work which has been carried out on theisomerism of the organo-metallic compounds of pyrrole under theaction of ethyl chlorocarbonate and ethyl carbonate deserve ex-amination.Potassiopyrrole yields differently substituted pyrrolederivatives according to the reagent used to replace the potassiumatom. Thus with alkyl iodides it gives mainly l-pyrrole deriv-atives; with the chloroanhydrides of acids the yield is made upof 1- and 2-derivatives in almost equal proportions, whilst theaction of anhydrides furnishes 2-derivatives as thO chief product.This behaviour may be explained on either of two assumptions, forwe may assume that in all cases a l-compound is produced whichunder the conditions of reaction may be transformed to a greateror less extent into a 2-derivative, or we may suppose that the2-compounds are formed by a single reaction and that no inter-mediate stage exists in the reaction.Now, in the case of theGrignard reagent, i t is necessary to assume that if isomerisationtakes place a t all i t must occur before the magnesium atom isremoved from the molecule, and this might lead us to the deduc-tion that the organo-metallic complex always enters the pyrrolenucleus in the 2-position. This view, however, has received a shockfrom the recent experiments with ethyl chlorocarbonate and ethylcarbonate. When magnesium pyrryl bromide reacts with the firstof these compounds, the result is a 2-derivative, whereas whenethyl carbonate is used the main product is ethyl pyrrole-l-carb-oxylate. Thus the organo-magnesium compound behaves just likepotassiopyrrole, and it seems reasonable tol suppose that both aremixtlures of the 1- and 2-forms, and not homogeneous substances.Unless it is assumed that the whole magnesio-bromide radiclewanders intramolecularly, we are driven to the conclusion that theGrignard reagent attacks both the 1- and the 2-positionssimultaneously.The Grignard reagent has come into use in another section ofl5 V.V. Tschelincev and S. G. Karmanov, J. Rum. Phys. Chem SOC.,1915, 47, 161 ; A., i, 297.F138 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the pyrrole group, for it has been shown16 that this reagentfurnishes a simple means of distinguishing between tertiary andsecondary pyrroles. The results, which were a t one time disputed,appear to be accurate, and no action takes place with tertiary com-pounds, whilst the secondary substances do react with the Grignardreagent.The formation of tripyrrole by the union of three molecules ofpyrrole is one of the well-known reactions in the heterocyclicseries, and itl has hitherto been assumed that the polymeric com-pound had the structureI l l I I I l l\/--\/-\/NH NH N HThe evidence in favour of this view may be summed up verybriefly.When heat,ed, tripyrrole decomposes into ammonia,pyrrole, and indole, a reaction which can be expressed by thefollowing f ormulze :;C;. H--YH-YII--F;H--FK-EH CH=CH-$-C + EH-SHCH CH-CH CH-CH CH jNH3+dH=CH-C C C CH\/ \/ \/N H NH NH\/ \/N H NHFurther, it was found that when 2- and 3-monosubstituted pyrroleswere used in place of pyrrole itself, the end-products of polymerisa-tion were not tripyrrole derivatives, but were substances of thebinary type which yielded indole derivatives when heated withsulphuric acid.A new series of investigations17 has thrown very grave doubton the older method of formulation; and since the subject isimportant from the point of view of some naturally occurringpyrrole derivatives, some account of the new work must be givenin this place.Tripyrrole hydrochloride is prepared by passing dry hydrogenchloride through a benzene solution of pyrroIe.I f t l e aboveformula (Dennstedt’s) were correct, magnesium propyl iodideshould react with tripyrrole, giving a derivative containing threeMgBr residues. Actual experiment proves, however, that only oneimino-hydrogen atom reacts with the Grignard reagent, so that itseems reasonable to conclude that either of two cases has presenteditself. On the one hand, the reactions of the two remaining imino-groups of the Dennstedt formula may be masked in their actionby some inhibitory mechanism, or on the other there may be onIylo B.Oddo, Ber., 1914, 47, 2427; A., i, 451.l7 V. V. Tschelincev, B. V. Tronov, and B. I. Voskresenski, J . Russ. Phys.Chem. SOC., 1915,47, 1224; A., i, 1008ORGANIC CHEMISTRY. 139a single imino-gro,up in the tripyrrole structure. It is safer tochoose the second possibility and investigate it before examiningthe first.Three structures may be suggested for tripyrrole, each of whichcontains only a single imino-radicle :(111.)The first of these may be ruled out, as under the influence of theGrignard reagent it would probably pass by tautomeric changeinto the Dennstedt structure and show the reactions of threeimino-radicles.The remaining two formulae can be brought intoline with the decomposition reaction of tripyrrole, with the forma-tion of indole. The decomposition would be represented (in thecase of formula 11) on lines similar to those employed in the olderformulation by Dennstedt, while in the case of formula I11 theready decomposition of tripyrrole with the liberation of ammoniafinds a close parallel in the case of the amidines. A further pointin favour of the two new formuh as against that of Dennstedtlies in the fact that tripyrrole hydrochloride contains only a singlemolecule of hydrogen chloride, whereas since there is no markeddifference between the irnino-groups of the Dennstedt structureone might reasonably expect to find either a di- or tri-hydrochlorideformed by the substance.The polymerisation of pyrrole to tripyrrole is a well-known re-action, but it was not until recently18 that any study had beenmade of similar condensations in the case of the trisubstitutedpyrrole series.The results obtained are said to throw light onthe constitution of certain pyrroles which are of interest fromtheir relation to the bile acids. Thus, hzmopyrrole-e is regardedas polymerised cryptopyrrole, hzmopyrrole-g is supposed to be animpure phyllopyrrole, and hzmopyrrole-f is taken to be anotherdimeric form belonging t o the same class.The aldehydes of pyrrole have also been submitted to investiga-lS H.Fischer, Ber., 1915, 4$, 401; A., i, 460.F* 140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion, and two methods of preparing pyrrole-2-aldehyde aredescribed in the year's literature. Magnesium pyrryl bromidereacts with ethyl formate to produce the required aldehyde,lg andthe same substance ig obtained by the action of isoamyl formateon pyrrole in presence of sodium.20 I n this connexion, it isinteresting to note that Angeli and Alessandri g1 have put forwardthe view that the compound in questmion is not a true aldehyde, buthas the hydroxymethylenic structure :The synthesis of a new colouring matter from pyrrole22 seemslikely to yield materials for further investigations, for the newsubstance is allied on the 'one hand to the triphenylmethane dyesand on the other to difluorene, fulvene, indigotin, and possibly t ohaemin and chlorophyll as well.The reaction between benzo-phenone and pyrrole (in alcoholic solution with a trace of hydro-chloric acid present as a catalyst) yields two main products, namely,diphenyl-2-pyrrylcarbinol and diphenyldi-2-pyrrylmethane. Thelatter is derived from the former by the interaction of a secondmolecule of pyrrole. It appears that the carbinol can be preparedalso by the action of magnesium pyrryl bromide on benzophenone,and the removal of the elements of water from it results in theformation of a colouring matter which has the following structure :N l j l\/ x CPb,Treatment with zinccoloured base into theThe colouring matterappear to be stable.dust and hydrochloric acid converts thecorresponding leuco-compound,dyes tissues raspberry-red, and the tintsC,H,N*CHPli,.Pyridin e.10 the Report of last year23 attention was called to the use ofpyridine as a solvent and catalytic reagent, and during the presenttwelvemonth there has been a further addition t o our knowledgein this branch of the subject.24 When thiophenol is dissolved in19 V.V. Tschelincev and A. Terenthev, Ber., 1914, 47, 2652; A., i, 452.2O L. Alessandri, Atti R. Accad. Lincei, 1914, [v], 23, ii, 65; A., i, 452.21 A. Angeli and L. Alessandri, ibid., ii, 93; A., i , 454.22 V. V. Tschelincev, B. V. Tronov, and A. P. Terentdev, J. Russ.Phys.23 Ann. Report, 1914, 146.24 M. Raffo and G. Rossi, Gaxzetta, 1915, 45, i, 28; A., i, 86.Clhern. SOC., 1915, 47, 1211 ; A., i, 990ORGANIC CHEMISTRY. 141pyridine, the solution, on boiling, yields phenyl disulphide as aprincipal product. The evolution of hydrogen sulphide indicatesthat other reactions also take place in the solution. A pyridinesolution of thiobenzanilide also liberates hydrogen sulphide wheni t is boiled, and if the heating is continued until no further evolu-tion of gas takes place, the principal product is a substance whichmay be either NPh:CPh*NPh-CSPh or NPh:CPh=S*CPh:NPh.Similar treatment converts phenylallylthiocarbamide into hydrogensulphide, allylthiocarbamide, and N-phenylpropylene-q-thiocarb-amide : YHMe- s>c.NHPh.C H,---NAn examination of some selenium compounds shows that theyalso are decomposed by heated pyridine.Diphenylseleniocarbamideyields hydrogen selenide and carbodiphenylimide ; but furtherreactions then occur which end in the production of aniline,triphenylguanidine, and carbanilide.Pyridine is acted on by sodium a t the ordinary temperature,and when the reaction is carried out in an atmosphere of nitrogenthe product is obtained quite pure.25 No gas is evolved, and inthe final substance it is found that pyridine is present in theproportion of two molecules of pyridine to one atom of sodium.When the experiment is carried out with the reagents in otherproportions there is always a residue of the substance present ingreatest quantity.The compound (C5H,N),Na thus obtained seemsto be analogous to the ammonia derivative (NH3),Na. Picolinebehaves in the same manner as pyridine so far as this reaction isconcerned.Another new reaction of the pyridine nucleus26 appears to becapable of wider exteasion. Sodamide is allowed to react withpyridine and the temperature is maintained below 120O. Whenthe reaction has run its course, the product is decomposed withwater, and it is found that a 70 per cent. yield of 2-aminopyridineis obtained. The reactions involved are evidently the following :C,H,N + NH,Na = C,H4N*NHNa + H,,C5H4N*NHNa + H,O = C,H4N*NH2 + NaOH.Further action of sodamide on pyridine is found t o lead to thedisplacement of both a-hydrogen atoms by amino-radicles, so thak2 : 6-diaminopyridine is produced.The latter substance seems likelyto have a technical importance, since it can be coupled with diazo-compounds, yielding true azo-dyes. Various other compounds have25 B. Emmert, Ber., 1914, 47, 2598; A . , i, 454.26 A. E. Tschitschibabin and 0. A. Zeide, J . Russ. Phys. Chem. Soc., 1914,46, 1216; A., i, 590142 ANNUAL REPORTS OK THE PROGRESS OF CHEMISTRY.been obtained by the action of sodamide on pyridine derivatives,but it is unnecessary here to enter into details.The nitration of pyridine itself presents very considerable diffi-culties, but the presence of an a?mino-group in the molecule appearsto increase the readiness with which nitration takes place, andit is found that 2-aminopyridine undergoes nitration with almostthe same ease as aniline.27 The chief product of the reaction is5-nitro-Z-aminopyridine, although i t is accompanied by an isomericsubstance which may be 3-nitro-2-aminopyridine.The nitro-pyridines resemble the nitroanilines to a certain extent, beingyellow compounds of feeble basicity. When an attempt is madeto diazotise the nitroaminopyridines, no diazo-compound can beisolated; but if the reaction is conducted in concentrated hydro-chloric acid solution the amino-group of 5-nitro-2-aminopyridine isreplaced by a chlorine atom, so that evidently under these condi-tions diazotisation does occur.Another amino-derivative of pyridine is obtained by heating4-chloropyridine with fresh zinc ammonium chloride to 220-230°in a sealed tube.28Sulphonation of the pyridine nucleus is readily accomplishedif t<he reaction be carried out in the presence of vanadyl sulphate;other catalysts have been examined, but their effect is not so good.Impure pyridine appelars to be much less easily sulphonated thanthe pure substan~e.~gPentaaole Compounds.Some very interesting compounds containing a five-memberedring built up entirely from nitrogen at'oms have been synthesised 30during the current year, and it seems probable that valuableresults may follow when the field has been further examined.If hydrazine hydrate is warmed with an alcoholic solution ofcyanotetrazole, ammonia is liberated and a yellow precipitate ofpent'azolylacetohydrazidine (I) is formed.More ammonia is evolvedr : N >N~cH,~c(:NH)~NH-NH', N: N(1.) (11.1when this substance is boiled with aque,ous potassium hydroxide,and the end-product of the reaction is the potassium salt of penta-zolylacetohydrazide (11).Oxidation of this last substance with potassium permanganate in27 A. E. Tschitschibabin, J. Russ. Phys. Chem. SOC., 1914,46,1236; A.,i, 591.28 B. Emmert and W. Dorn, Ber., 1915, 48, 687; A . , i, 584.3O I. Lifschitz, Ber., 1915, 4$, 419; A., i, 465. [Compare, however, T.H. Meyer and W. Ritter, Monatsh., 1914, 35, 765; A., i, 715.Curtius, A. Darapsky, andE. Muller, ibid., 1614: A., 1916, i, 84.ORGANlC CHEMISTRY. 143hot aqueous solution eliminates the hydrazine group with theforrnatio,n of the potassium salt of pentazolylacetic acid (111).When a suspension of pentazolylacet80hydrazine in a solution con-taining excess of sodium nitrite is treated with hydrochloric acid,>N C(: NOH) CO N H* NH,r : N y:N,>N*CH,*CO,H N:?J N:B(111.) vv.)pentazolyloximinoacetohydrazide (TV) separates out in red crystals ;this substance readily undergoes change in either of two ways.When heated in alcoholic solution with a little hydrochloric acidi t can be hydrolysed t o pentazolyloximinoacetic acid (V), whereasif i t is allowed to undergo spontaneous condensation it eliminatesy:N>N*C(:NOH)*CO,H N:N(V. ) (VI. 1a molecule of water and forms an unstable triazolone deriv-ative (VI).Pentazolyloximinoacetic acid is slowly oxidise’d by an ammonia-cal solution of silver nitrate, yielding, apparently, pentazolylgly-osylic hcid (VII):>N*CO*CO,Hr : NN:N(VII.)The silver salt of t h e oximino-acid is soluble in warm potassiumhydroxide solution, and when the solution so obttained is treatesdwith silver nitrate and nitric acid a colourless, flocculent precipi-tate is formed which apparently consists of silver pentazole, N,Ag.From the foregoing i t will be, seen that even five-memberednitrogen rings exhibit a marked stability, and further investiga-tions in this field cannot fail to yield results of very considerablevalue.The Reactions of the y-Chloroketones.A study of the interactions between various y-chloroketones andcertain amino-derivatives has resulted in the discovery of whatappears t o be a general method for the preparation of certainheterocyclic substances.31 The behaviour of various chloroketonestowards ammonia, hydroxylamine, hydrazine hydrate semi-carbazide, and phenylhydrazine leads to the following results.Alcoholic ammonia and ethyl y-chloro-n-butyl ketone do not appearto yield any appreciable yield of a base, for the principal productof the reaction is a trimethylenic ketone.The action of hydroxyl-amine proceeds in two stages, the first of which is oximation, whilst31 H. Wohlgemuth, Ann. Chim., 1914, [ix], 2, 40.3: A . , i , 164144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the second produces a cyclic compound. Thus, in the case of ethyly-chloro-n-butyl ketone, the oxime can be isolated, and when i t isheated with pyridine the product is chiefly 6-methyl-3-ethyl-5 : 6-di hydroiso oxazine :CH2<CEt:N*OH + C H q C E t ~ N H > O .Ethyl y-chloropropyl ketone reacts analogously, producing 3-ethyl-5 : 6-dihydroisooxazine. With hydrazine hydrate, the y-chloro-ketones give rise directly to cyclic compounds, For example, ethyly-chloropropyl ketone yields 3-ethyltetrahydropyridazine,CH,*CHMeCi CH, CHMeWhen a concentrated aqueous solution of the hydrochloride of thelatter compound is allowed to react with potassium cyanate, theresult of the process is t o produce l-carbamyl-3-ethyltetrahydro-pyridazine. This substance is also obtainable from ethyl y-chloro-propyl ketone and semicarbazide.The semicarbazide is firstformed, and on heating in pyridine solution i t passes over into thepyridazine derivative, as shown below :The action of phenylhydrazine on the chloroketones seems to takeplace in one stage with the production of N-phenyltetrahydro-pyridazines. F o r instance, in the citse of ethyl y-chloro-n-butylketone, the end-product of the reaction is l-phenyl-6-methyl-3-et hyltetrahydropyridazine,It will be seen that this reaction is capable of wide extension, andmay serve to simplify the syntheses of certain heterocyclic sub-stances.Some Blue Adsorption, Compounds of Iodine.Three years ago, a series of investigations was carried out onthe adsorption of iodine by various substances, such as cholalicacid, saponarin, and other natural compounds,32 and this line ofwork has now been extended t o the heterocyclic division of organicchemistry, for it has been observed33 that numerous synthetic sub-stances of known structure also possess the faculty of formingadsorption compounds with iodine.The newer data are of especialinterest, as they open up a line of research which may eventually32 G. Barger and Miss E. Field, T., 1912, 101, 1394.33 G. Barger and W. W. Starling, ibid., 1915, 107, 411ORGANIC CHEMISTRY. 145throw a clear light on the relations between chemical constitutionand adsorptive power.Blue compounds are not formed by substances in the moleculardisperse condition, nor do preformed crystals show absorptionphenomena to any noticeable extent. I n order to obtain the bluecompounds with iodine, it is essential that the adsorbing substanceshould be present as a colloidal solution or as an amorphous gel.When in the crystalline condition, some of the substances ex-amined gave mixed crystals with iodine, and it was occasionallyobserved that the blue adsorption compound on keeping becameconverted into these mixed crystals.It will be sufficient t o mention here the classes of compoundswhich have been investigated, as it would occupy too much spaceto deal in detail with the results that have been obtained.Abouttwenty derivatives of a-pyrone were examined, some of which gavemixed crystals, whilst others yielded adsorption compounds. Adozen derivatives of y-pyrone showed an analogous behaviour. I nthe case of xanthone and its derivatives no mixed crystals wereproduced, although adsorption phenomena were observed.I n theflavone group, both adsorption and mixed crystal formation werenoticed, but it was found that flavanones containing a reducedpyrone ring are indifferent to iodine. The behaviour of pyronederivatives containing sulphur (such as thiocoumarin, thioxanthoneand its allies) was found to be similar to that of the other classes,mixed crystals being observed in some cases, whilst adsorptioncompounds were formed in other experiments. The thioflavonesare similar to the oxygen analogues, except that in the case of theformer the adsorption requires longer time to make itself marked.As regards the influence of chemical structure on the adsorptionphenomena, the following facts appear to be important. Takingthe case of the pyrone derivatives, it has been found that certainsubstances give blue compounds, whereas others, very closely alliedto them chemically, do not exhibit the phenomena of adsorptionto any extent.Thus even a trifling alteration in chemical struc-ture seems to exert a marked inhibitive effect on the process. Thepresence of a crossed conjugated double linking seems to be ofCHR:CH*C):O ,CHICHI3especial significance in the problem. An increase in the numberof the aryl groups in a molecule tends t o raise the adsorptivepower, whilst the heaping up of alkyl radiclw appears to have, anopposite effect. On the data available it seems probable that thechief factor in the question is residual affinity, but a t present i146 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.is difficult to go bejyond this very general statemeat.Furtherdetailed information will probably lead t o most interesting con-clusions.Tetranitromethane as a Reagent for Measuring Residual A finity.It has already been pointed out 54 that tetranitromethane yieldscolorations when mixed with compounds containing atoms whichare capable of exercising a higher degree of valency, and this workhas now been carried further.35 The following heterocyclic sub-stances have been examined : pentamethylene sulphide, 1 : 4-thioxan, tetrahydro-1 : 4-thiopyran, and 1 : 4-dithian. Quantitativeinvestigation with the spectrograph shows that in each case themixture of tetranitromethane and the compound under examina-tion has selective absorption with a maximum at l / h 2850 and apenetration depending on the time which has elapsed since mix-ing.This points to the formation of a series of very similar com-pounds in the mixture, and the increasing penetration of the bandis clearly due to the increase in thO amount of the product formedas time goes on. Thus the rate of increase in the persistence ofthe band may be utilised as a test of the velocity of the reaction,and hence as an index of the reactivity of the compound whichis reacting with the tetranitromethane. These deductions havebeen tested in certain cases by comparison with experimental dataobtained from actual reactivity measurements, and the agreementbetween the two sets of results is a close one.Certain inhibitive factors have been detected in some cases.Thus the presence of a halogen atom in the molecule appears todiminish the reactive power of the compound as compared withthat of its halogen-free analogue, and similar results are notedwhen conjugation occurs within the molecule.It is pointed out that alkyl nitrites may replace tetranitro-methane, and yet the same type of selective absorption is pro-duced, and on this evidence i t is assumed that the colorations arenot produced by ordinary tetranitromethane, but arise only afterthe tetranitromethane has undergone intramolecular change intoa “nitritic” form. This view is supported by a spectrographicexamination of tetranitromethane under various conditions.Theinfluence of the solvent on the reaction has also been studied insome detail.34 H.T. Clarke, A. K. Macbeth, and A. W. Stewart, P., 1913, 29, 161.35 E. M. Harper and A. K. Macbeth, T., 1915, 107, 87; A. K. Macbeth,ibid., 1824ORGANIC CHEMISTRY. 147kX/?OH1/ HIt appears probable that this line of investigation is open tomuch wider applications, and as it throws a certain amount of newlight on the vexed question of intermediate compounds or inter-mediate “molecular phases” i t is to be hoped that further re-searches will be carried out.ICMe,-O--CPhI I /YH 11CH CPh---/ HSome Oxoitiiiin Compounds.The interaction of magnesium phenylacetylene bromide andbenzoyldimethylcarbinol yields a pinacone (I) which, on boilingwith 20 per cent.sulphuric acid, is converted into 4-hydroxy-2 :4-diphenyl-5 : 5-dimethyl-4 : 5-dihydrofuran (11) :36 A. Favorski and Mlle. E. Venus, J . Russ. Phys. Chenz. SOC., 1915, 47,133; A., i, 289148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRI'.oxonium salts of 9-phenylxanthonium has been carried out withthe following results: 37/\ I 41 \?'xThe unsubstituted salts exist only in the solid state or in presenceof a large excess of a strong acid; the introduction of methylgroups in the positions 2 and 7 has little influence, but the sub-stitution of methyl for hydrogen in the positions 3 and 6 appar-ently increases the stability of the salts to a t least a hundred timesthe original value. The presence of a carboxyl group a t the posi-tion 2' lowe'rs ths stability markedly, but the esterification of thecarboxyl group tends to raise the stability of the oxonium deriv-atives again.A somewhat more extensive series of investigations in the samedirection has been commenced, of which the first part has beenpublished." The substances chown for examination belong t o six-membered cyclic systems of the following types :(V.1 (VI.1 (VII. )0 0 0 0 /\/\c() /\/\GO /\/\CH /\/\coI l l I I ICO I 1 IlCH I I ICH\ / \ P H 2 \/\/ \/\/ R(3%\/\/CH(XI.)0 0(VIII. (IX. 1 (X.)37 F. Kehrmann and A. Bohn, Be?., 1914,47, 3052; A., i, 575.38 B. N. Ghosh, T., 1915, 107, 1588ORGANIC CHEMISTRY. 149I n order to study the basic properties of these oxygen derivatives,perchloric acid has been selected, and with this reagent the follow-ing results have been observed.When one oxygen atom alone is a member of the ring, the powerof salt-formation is much influenced by the nature of the remainderof the molecule. Thus tetrahydropyran (I) and dihydrobenzpyran(111) yield no salts, but the presence of further unsaturatedradicles seems to enhance the basicity of the oxygen atom, sincesalts are formed by l-methylene-l : 4-benzopyran (X), thecoumarins, and the y-pyrone derivatives.Somewhat similar pheno-mena are observed in the case where the six-membered ring isbuilt up partly from two oxygen atoms. Dioxan (11) and benz-dioxan (IV) yield no perchlorates, but the power of addition isgained when extra unsaturatian is found in the molecular struc-ture, as in the case of diketodioxan (V), di-aP-naphthdioxin (VI),diketobenz-PP-naphthdioxin (VII), ketodihydrobenzdioxin (VIII),and diketodihydrobenzdioxin (IX), all of which yield perchlorates.From these results it seems fair to deduce that the power ofbivalent oxygen to form additive compounds with acids is in-creased by the entrance into the molecule of (( negative ” radiclessuch as the ethylenic bond or the carbonyl group.Further investigations on the nature of dimethylpyrone hydro-chloride have been and from evidence based on con-ductivity measurements it is concluded that the substance is a truesalt which is correctly represented by the oxonium formula. I nthis connexion it, may be well to mention that a study of certainamino-derivatives of camphoric acid 43 leads to the conclusion thatcyclic salts are formed having the structure R<-’O->O,- so thatthe views of Werner on the nature of “onium” salts receive nosupport in this region.NW,Pyrones and their Allies.An attempt41 has been made to obtain reduction products ofdimethylpyrone by means of various agents.As was already known,zinc dust and glacial acetic acid do not effect this reduction, butthe addition of concentrated hydrochloric acid produces a bluish-violet coloration. When magnesium powder is substituted for zincdust., the process seems to be facilitated. The reduction product39 H. N. K. Rordam, J . Amer. Chem. SOC., 1915,37, 557; A., i, 292; compareAnn. Report, 1914, 130, and A. Baeyer and J. Piccard, Annalen, 1915, 4Q7,332; A., i, 290.40 W.A. Noyes and R. S. Potter, ibid., 189; A , , i, 79.41 A. Baeyer and J. Piccard, Annalen, 1916, 407, 332; A., i, 290150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.has not been isolated, but its perchlorate appears to have the com-position C14H1602,HC104. The reduction of dimethylpyrone bymagnesium powder, glacial acetic acid, and methyl alcohol in theabsence of air produces a leuco-compound of the colour base men-tioned above. This leuco-compound seems to have the formulaC14H1s02, and shows no reaction with alkalis, ammonia, potassium,cold beazoyl chloride, or phenylhydrazine. In acetone solutionit is oxidised by air when an aqueous mineral acid is present. Aglacial acetic solution of the leuco-compound in an atmosphere ofcarbon dioxide takes up two atoms of bromine and is convertedinto a derivative of the colour-base.Two further atomic propor-tions of bromine can react with this last substance, giving adehydro-derivative.Another, and apparently cleaner, method of reduction whichcan be employed in the pyroiie series is the action of hydrogen inthe presence of palladium and gum arabic. I n this way 4-pyroneis reduced to the tetrahydro-derivative, whilst dimethylpyrone andethyl chelidonate yield analogous products. It has been observedthat the reduced compounds boil a t much lower temperatures thando the parent substances.A study of the condensation of aldehydes with B-diketones49 hasled to the syntheses by this method of certain reduced pysone deriv-atives, and as the results appear to demonstrate the errors of aprevious experimenter,U they may be given here in some detail.The action of benzaldehyde on acetylacetone in the presence ofalcoholic hydrogen chloride doee not produce the expected condensa-tion product CHPh:CH*CO*CH,*CO*CH,, but yields a, substancecontaining chlorine which, when heated in a vacuum, forms an oilycompound having the structure CH,*CO*C(:CHPh)*CO*CH,.Thereaction can be made to take another course by introducing twomethyl radicles in place of hydrogen atoms in the methylene groupof the acetylacetone. When this is done the condensation withbenzaldehyde yields bright red crystals which when exposed to aireliminate hydrochloric acid and become colourless.The colourlesssubstance has the composition C25H2302Cl, and when heated withpyridine it produces a crystalline substance of the compositionC,,H,,O,. The latter compound reacts with hydroxylamine andwith bromine; additive compounds are formed in each case betweenone molecule of the compound and one molecule of hydroxylamineor bromine. Prolonged boiling with alkali has no effect on thecolourless subst'ance, which is therefore not a @-diketone derivativeof the normal type. The reaction with hydroxylamine points to42 W. Borsche, Ber., 1915, 4$, 682; A., i, 574.43 H. Ryan and J. 35. Dunlea, ibid., 1914, 47, 2423; A., i, 416.44 M. G. Heller, ibid., 887, 2998; A., 1914, 563, 417ORGANIC CHEMISTRY. 151the presence of the grouping *C:C*CO* in the molecule, whilst theformation of an unstabIe red additive compound with hydrochloricacid indicates that the substance contains a pyrone nucleus.Thesubstitution of methylacetylacetone for the dimethyl derivativemakes no alteration in the end-product of the reaction, whencei t follows that one or more methyl radicles evidently are eliminatedduring the operations. This and other evidence leads to the con-clusion that the series of reactions can best be formulated in thefollowing manner :Ph*CHO + CH3*CO*C(CH,),*CO*CH3 + HC1=Ph*CH:CH*CO.CH(CH,)*CO.CH, + HzO =Ph*CH:CH*CO*CH,*CH, + Ph;CHO =The latter compound is then changed into an isomeride (I) whichPh*CH:CH*CO*CH(CH,)*CO-CH, + H,O + CH,Cl.Ph*CH:CH*CO*CH,*CH, + CH,*CO,H.Ph*CH:CH*CO*CH(CH,)*CHPh*OH.CE-1Me.C: fd Pit CH&L.---- CHPh H“o<CH2--CHPh >’ Co<CH(CHPhC1)*CHPh>o<CI(1. ) (11.)CHMe--- CH Ph>O CO<CHMe--CHPh>Oco<CH(CHPhCI) C 11 Pi1 C(:CHPh)*C HPh(111.) (IV. 1reacts with benzaldehyde and hydrochloric acid to form theunstable red oxonium salt (11). Hydrochloric acid is then elimin-ated, with bhe result that (111) and (IV) are produced in suc-cession.Following upon previous studies of the reactions shown bysubstances containing one ox more “ keten ” group6,45 a furtheradvance has been made in the current year.46 It has already beenshown that diacetylacetone can be converted, by loss of the elementsof water, into either dimethylpyrone or orcinol, and it has nowbeen found that when the latter compound is condensed wit’hacetylacetone, which also contains the “ keten ” group, two newbasic substances are produced, which belong to the benzopyranolseries, and are therefore allied to natural dyes, such as apigenin.The two substances have the structures shown below:nGives lernon-yeflowhydrochloride.nCH,Gives orangehydrochloride.45 J.N. Collie, T., 1907, 91, 1806.46 J. N. Collie and G. N. White, ibid., 1915, 107, 369152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.It is possible t o write the structure of these compounds in thequinonoid form thus :0\/\/\CMe\/\P"0I t 'Me CMebut it should be noted that attempts to prove the presence of acarbonyl radicle have failed in each case, whereas acetylation ofthe hydroxyl group appears to be relatively simple.The acetylderivatives seem to have lost the power of salt-formation which ispossessed by the parent substances. The following explanationappears to cover most of the facts. In the free state or in the formof salts both subst'ances are quinonoid; when the acetyl derivativeis formed no quinonoid structure can be produced, so that thecompound is colourless. I n sodium hydroxide solution, whichfavours the production of the hydroxyl form, the substances areweakened in coloizr, in one case becoming almost colourless.Benzopyrone aizd Flavone Derivatives.When ethyl acetoacetate is condensed with phenols in thepresence of sulphuric acid the reaction produces coumarin deriv-atives, as shown in (I); whereas the interaction of a m-dihydroxy-phenol and acetyl- or benzoyl-acetone in the presence of hydrogenchloride results in the formation of methylenesubstituted pyronesa0 in (11):\/ 0/\OH /\/\c()1 ' C(CH,):CH*CO,Et * ' ICH \/- \/\..I(1.1 hH3/\/\c*80+ OH*C(:CH,)*CH:CX*OH + I { [IGH\/ \/\/(11.) CH,The corresponding reaction has now been studied 47 with ethylacetoacetate, in which the active hydrogen atoms have beenreplaced by alkyl groups.In the case of the dimethyl derivative*' S. Jacobson and B. N. Ghosh, T., 1915, 107, 424, 959, 1051ORCX AN IC CHE h21 STRY . 153of ethyl acetoacetate no condensation occurred a t all. The mono-ethyl derivative yielded a mixture of two substances which weresupposed to be a y-benzopyrone and a coumarin; whilst whenethyl benzylacetoacetate was used, the product was found to be ay-benzopyrone.These results establish the fact that the com-plexity of the substituent group has a very marked influence onthe course of the reaction.It is possible to assume that when there is no substituentpresent the reactivity of the hydrogen atom is very great, and thatthe hydroxyl group of the ester condenses a t once with thehydrogen atom in the ortho-position with respect to the hydroxylgroup of the phenol, whilst in the second stage of the reaction amolecule of alcohol is eliminated, as is shown in (I). On the otherhand, when a monomethyl-substituted ester is employed, the, reac-tivity of the1 remaining hydrogen atom in the met.hylene groupis diminished by the substitution, and it is unable to condensewith t h s hydrogen atom attached t o the benzene nucleus.It hasstill sufficient reactivity left t o enable it to condense with thephenolic hydroxyl group, and the reaction ends with the elimina-tion of ethyl alcohol and ring-formation as shown in (111). A very(\OH + CO,Et*CR:C(CH,)*OH -+\/n n(111)considerable amount of data has been accumulated with regard tothe influence of substituents on the reaction, but it is impossibleto deal with the matter fully in a Report.A richly hydroxylated flavone derivative48 has been prepared bycondensing 2 : 4 : 6-trimethoxyacetophenone with the trimethylether of methyl gallate in the presence of sodium, and demethylat;ing the product by boiling it with hydriodic acid.Under thistreatment the initially formed hexahydroxybenzoylacetophenoneloses the elements of water and yields 5 : 7 : 3' : 4' : 5/-pentahydroxy-flavone. Attempts were made, to reduce this substance by thOaction of hydrogen and palladium-black under low pressure, butno resulk were obtained.I n continuation of the work begun last year49 further attempts48 G. Bargellini and L. Monti, Gazzetta, 1915, 45, i, 64; A., i, 84.4~3 Ann. Report, 1914, 133154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.have been made50 with the object of deepening the colour of flavonederivatives by the introduction into their nuclei sf auxochromegroups. Luteolin and morin ethers have been nitrated, and thenitro-groups have been reduced to amino-groups.The influence ofthe new auxochromes has been studied spectroscopically, and i t hasbeen found that a multiplication of auxochrome groups results ina widening of the principal absorption band and a slight shiftin its position towards the red end of the spectrum. The effecton the second band which lies in the violet and ultra-violet isapparent in the spectroscope; but so far as visible appearances gothe alteration in this band has little influence on the colour of thesubstances.A new synthesis of fisetin51 has been devised which is based onthe following scheme of reactions. The yield obtained is, how-ever, only 5 per cent. of the theoretical in the case of fisetintrimethyl ether, and a further loss will naturally occur beforefisetin itself can be liberated :OMe*C6H,<$o>CH, + OMe*CBH,<~~>C:CH*C6H,(OMe)2OMe*C,II,<~~>CCl CHCl* C,H3(OBle) -+An entirely new type of flavone derivative, has been obtained thisyear52 which may become of considerable technical importance.Itmay be well to illustrate its relation to the ordinary members ofthe flavone series by formulze:Flavone. Diflavone.0 0 0co co coDiflavanone. Chromone.0/\/'CHPhcoI l l\ / \ P H 2Flavanone.0 0Dichromone.The new substance has been termed diflavone, and the namesso A. G. Perkin and E. R. Watson, T., 1915,107, 198.5l K. von Auwers and P. Pohl, Ber., 1915, 48, 85; A., i, 154.52 H. Ryan and Miss P. O'Neill, Proc. Roy. Irish Acad., 1915, 32, 48, 167;A ., i , 707, 1071ORGANIC CHEMISTRY. 155dichromonel and diflavanone have provisionally been attached to thestill unknown but corresponding substances.Diflavone is obtained as follows : Dimethyldiacetoresorcinol whenallowed to react with benzaldehyde produces the dimethyl ether ofdihydroxydichalkone, from which by acetylation and brominationthe diacetate of dihydroxydichalkone tetrabromide was synthesised.The latter compound (I) when acted on by alcoholic potassiumhydroxide, produces a mixture of diflavone (11) and dibenzylidene-dicoumarinone (111) :C H , ~ C O ~ O ~ ~ ~ O ~ CO-CH,CHPhBr* CHBr COI ICO*CHBr*CH PhBr \/0 0CPb/\/\/\CPh ()-/\-()cO-\/-O cH\/\/\/CHCHPh:C! 1 1 h:CHPhI Ico co(11.1 (111. )I l l I I ;Another metho,d of synthesis starts with dibenzoylacetoresorcinoldimethyl ether, which, on boiling with concentrat'ed hydriodic acid,is converted in two successive stages into benzoylacetomethoxy-flavone, and finally diflavone :nOwing to the fact that diflavone contains no auxochrome groupsi t is not to be expected that it would be strongly tinted, and itsactual colour is a very faint yellow, scarcely differing from ordinarycolourless Eavone.The effect of auxochromes on the molecule isa t present under examination.Plant Pigments and Allied Materials.In this field of investigation our knowledge is becoming verymuch more extensive than seemed likely a few months ago. A tpresent the methods of research are chiefly being directed to acquir-ing a general knowledge of many of the plant pigments rathe156 ANNUAL REPORTS OK THE PROGRESS OF CHEMISTRY,than a detailed acquaintance with single derivatives, but none theless a considerable amount of information with regard t o particularcompounds is being acquired.Certain yellow flavonol derivatives have been submitted to gentlereduction,53 and the substances resulting from this operation havebeen compared with natural cyanin.Resemblances can be tracedbetween the natural and artificial compounds in the followingrespects : (1) Stability in acid solution; (2) absorption spectrum,consisting of a single broad band, which becomes flatter towardsthe violet and extends over a great part of the green and blueregions; (3) oxidation in acid solution with the production ofcolourless products; (4) loss of colour on reduction, with restora-tion of the colour on addition of hydrogen peroxide; (5) formationin neutral solution of violet or reddish-violet compouiids, givingred oxonium salts with acids and blue or bluish-green compoundswith alkalis; (6) instability in presence of alkalis; (7) decolorisa-tion in neutral solutions (due to isomerisation) and quantitativereturn of the colour on adding acid.This is explained by Everest by the scheme:0 OH 0 OH/\O H HColourless product.6HAnthocyanin pigment frommyricetin.and this explanation is supported by evidence from other workers.Some investigations of rutin have led to the discovery of a redanthocyanin which may prove identical with cyanin, but the proofof identity is not yet complete.The colouring matter of the rose has been investigated," and ithas been shown that the anthocyanin present in this plant isidentical with that previously discovered in the cornflower.Thisfact is established by an examination of the absorption spectra,specific rotations, solubilities in ethyl alcohol, and dilute hydro-chloric acid of the cyanin chlorides, and it is further supportedby the hydrolysis of the substances to cyanidin and dextrose(2 mol.), which has been carried out quantitatively.The formula of cyanidin chloride has h e n modified by furtherinvestigation. The substance has been found to retain one molecule53 A. E. Everest, Proc. Rog. Soc., 1914, [ B ] , 88, 326; A., i, 25; compare64 R.WillstLtter and T. J. Nolan, Annalen, 1915, 408, 1; A., i, 282.Ann. Report, 1914, 140ORGANIC CHEMISTRY. 157of water with great tenacity, and this had been included in the'early formula for the substance. The actual composition of cyanidinchloride is therefore C,,H,,O,Cl, and not Cl6HI30,C1. This newfcrmulation cf cyanidin is of importance,ss since it brings into onenatural family pdargonidin, cyanidin, and delphinidin, whichdiffer from each other in the number of hydroxyl groups that theycontain. It seems probable that cyanidin chloride has the follow-ing structure, whilst pelargonidin chloride' contains one hydroxylgroup less (that in the 3'-position), and delphinidin chloridecontains an extra hydroxyl radicle in the 5/-position:Cl6 OHThe colouring matter of the whortleberry (Vacciwium vitis idaea)has been isolated and has received the name idaein.56 It is closelyallied to cyanin.On hydrolysis, it yields galactose (1 mol.) andcyanidin, which is identical with the cyanidin obtained from thecyanin of the row and cornflower.The flowers of scarlet pelargonium (Pelargoniz~m zonale, var.meteor) have now been found67 to contain only a single colouringmaterial, which is termed pelargonin. It forms scarlet oxoniumsalt^, and occilrs in this form in the flowers. On hydrolysis i t yieldsdextrose (2 mols.) and pelargonidin.Further investigations in this field 58 have been concerned withthe colouring of the hollyhock (Althaea rosea), which is due toalthaein; of the wild mallow (iilalva silvestris), the anthocyanin ofwhich has been named malvin; and of the peony, which is producedby peonin.Controversy has arisenS9 with regard to the results obtained inthe past with regard to the colouring matters of the grape andof the bilberry.From the results now a t our disposal, Willstiitterand Zollinger suggest that myrtillidin chloride (from bilbe'rries)and enidin chloride (from grapes) are respectively the 7-mono-methyl and the 3 : 4I-dimethyl ethers of delphinidin chloride.The anthocyanin delphinin occurs in the flowers of the larkspur(Delphinium consolida), and has been extracted from them by a55 R. Willstatter and H. Mallison, Annulen, 1915,408, 15; A., i, 282.5 6 R. Willstatter and H. Mallison, ibid., 15; A., i, 282.57 R.Willstiitter and E. K. Bolton, ibid., 42; A., i, 283.58 R. Willstatter and K. Martin, ibid., 110; R. Willstatter and W. Mieg,59 R. Willstiitter and E. H. Zollinger, ibid., 83; A., i, 285.ibid., 122; R. Willstatter and T. J . Nolan, ibid., 136; A , , i , 287-8155 ANNUAL REPOnTS ON THE PROGRESS OF CHEMISTRY.simple method.60 When hydrolysed with hot hydrochloric acid,delphinin chloride is converted into dextrose (2 mols.), phydroxy-benzoic acid (2 mols.), and delphinidin chloride(, C,,H,,O,CI, theconstitution of which was mentioned above. Delphinidin chlorideis a quinonoid oxonium salt which forins blue salts with alkalis andred salts with acids, whilst in neutral solution i t passes into theThis investigation has been of exceptional interest from thetheoretical point of view for the following reason: Delphinindiffers from other anthocyanins which have hitherto been examinedin one important respect.When it is dissolved in neutral solventsit remains stable and is not converted into a $-base, and sincei t is insoluble in water and also in concentrated alcohol i t can beisolated without the us0 of chemical reagents. When this is donei t is found that the substance occurs in flowers unaccompanied byany mineral constituent. Now in earlier papers Willstatter andhis collaborators advanced the theory that the varied colours ofmany flowelrs were produced by a single anthocyanin, which,acting as an indicator, exhibits a red, violet, or blue colour accord-ing as the cell-juice of the plant in that particular case is acid,neutral, or alkaline.The isolation and examination of the colour-ing material has confirmed this view. The violet colouring matteris neutral. The addition of alkali alters the colour to blue, whilstthe acidification of the substance changes its tint to red. Thissubject is dealt with in more detail in a further paper.61$-base.The Alkaloids.I n former years the main lines of research in this field pointedin the direction of the determination of the constitutions of c a b i nbetter-knowr, but still unsynthesised alkaloids ; in the period a tpresent under review, however, this trend has been less marked,and, instead, the attention of chemists seems to be mainly directedtowards the isolation of new natural substances and to the tenta-tive experiments which mark the first steps in our knowledge ofsuch compounds.It will be convenient to deal chiefly with thecommoner alkaloids in the first place, and after this some of thenewly discovered compounds will be discussed.It may be recalled that there is a general agreement with regardto the probable formula for cinchonine, although the exact positionof a methylene group has n o t been determined with absolutecertainty; and in any of the recognised structures for the alkaloidthere, are two points a t which a reducing agent might make its80 R. Willstatter and W. Mieg, Annalen, 1915, M8, 61; A., i, 284.61 R. Willstatter and H. Mallison ibid., 147; A., i, 289ORGANIC CHEMISTRY. 159attack. These two points are the vinyl group and the pyridinenucleus.It has been shown62 that the application of Tafel’s elec-trolytic method yields a product containing four extra hydrogenatoms, but a se-examination of the products has led to resultssomewhat more complicated than were originally described.Instead of a single reduction product, a mixture of two bases wasobtained, the one of which is crystalline, whilst the other is oily.Both have the composit’ion C,,H,,N,. The nature of the crystal-line base appears to be placed beyond doubt by the fact thatoxidation converts i t into deoxycinchonine, from which evidenceit seems safe to assume that the base itself is dihydrode’oxycin-chonine. When it is reduced by means of sodium and amyl alcoholit is converked into a viscous oil which is apparently tetrahydro-deoxycin c honin e .The fact that during the reduction of the dihydro- to the tetra-hydrecompound two extra hydrogen atoms have attached them-selves to the partly reduced pyridine nucleus and have not dis-turbed the vinyl group appears to be supported by the followingevidence. Paal’s method of reduction when applied t o cinchonineproduce8 cinchotine by an attack on the vinyl radicle; it might beexpected that similar results would be obtained in the case ofdihydrodeoxycinchonine.When this compound is reduced inaqueous alcoholic solution in the presence of hydrogen and colloidalplatinum, however, it does not yield the tetrahydrodeoxycinchonine,but an isomeride, which, from analogy, should be dihydrodeoxy-chonine. I n this substance it seems reasonable to assume that thevinyl group has been reduced, as was the case in cinchonine itself,so that the isomeric compound obtained by the reduction withsodium and amyl alcohol is probably a tetrahydropyridine deriv-ative which contains the vinyl group intact.The action of chlorine on quinine and some of its derivatives hasbeen very fully studied.63 The method employed was to dissolvequinine hydrochloride in hydrochloric acid and then treat it withone, two, or three molecular equivalents of chlorine.When thealkaloid and chlorine interact in equimolecular proportions anadditive product, quinine dichloride, C,,H2,02N2C12, is formed,which behaves as a diacidic base, the derivatives of which resemblethe corresponding derivatives of quinine.Energetic treatmentwith alcoholic potassium hydoxide eliminates two molecules ofhydrogen chloride from the base and produces dehydroquinine.The action of two molecules of chlorine on a single molecule of62 M. Freund and J. A. W. Bredenberg, Annulen, 1914, 407, 43; A . ,a A. Christensen, Ber. Deut. pharm. Cfes., 1915, 25, 256; A., i, 711.i, 159160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.quinine hydrochloride produces the dihydrochloride of a basewhich is suFposed to have the following formula:When three molecular proportions of chlorine act on quinine hydro-chloride an unstable base is produced having the compositionC,gH,,0,N2Cl,; and a similar base containing one atom lessoxygen is formed by the action of chlorine on hydrochloroquinone.The difference between the two substances is ascribed to the dis-placement of the hydroxyl group by hydrogen in the sidechain ofthe first substance.Both bases liberate iodine from potassiumiodide, so it seems probable that each contains the grouping*CO*CC12 in the quinoline nucleus.When quinine dichloride is allowed to react with two furthermolecular proportions of chlorine, it does hot yield the baseproduced by the direct action of three molecular equivalents ofchlorine on quinine hydrochloride, but instead a new compound isf osmed having the composition C,gH,,0,N,C14. This has beenfound to contlain only one active chlorine atom, displaceable bythe action of potassium iodide.Reference may be made to some work on strychnine andbrucine,64 and also to the establishment of the fact that oxalicacid and an amino-acid of the composition C,,H,,O,N, occur asfission products 65 of strychninolonic acid-a.Before entering into the recent work on the constitution ofpavine66 it may be well to indicate briefly the relations betweenthe alkaloids of this family so that the general bearing of theinvestigation may be appreciated.The following scheme willsuffice :Papaverine Tetrahydropapaverine Dihydropapaverine (Pa vine)CzoH2sO4NandC20H2104N 2 0 25°4N .1 .1N-Meth y lparine and N-Methyl- Laudanosinepapaverinuirn + c,,H,?o,N Cz,H 2 i wsaltsWith regard to the formation of tetrahydropapaverine from papa-verine and of laudanosine from N-methylpapaverinium salts, the64 R.Ciusa and L. Vecchiotti, Atti R. Accad. Lincei, 1914, [v], 23, ii, 480 ;65 H. Leuchs and G. Schwaebel, Ber., 1915, 48, 1009; A., i, 713.66 F. L. Pyman, T., 1915,107, 176.A , i, 893ORGANLC CHEMLSTHY. 161reaction depends oil the reduction of the isoquinoline t o a tetra-liydroisoq~xinoline nucleus, as is shown in the following f orniulze :Papaverine. Tetrapapaverine.The operation which results in the formation of pavine frompapaverine is not so clear. Pavine is a secondary base, so thatone of the two new hydrogen atoms certainly has attached itselft o the nitrogen atom. This leaves the second hydrogen atom stillunaccounted for, and it might be supposed to attach itself a t eitherthe 1-, 3-, or 4-position.Pavine might thus be supposed to haveone of the three structures represented below :CH*CH2*C,H,(OMe), C*CH,*C,H,( Ohfe),\/\NHNCH CH CH(1.1 (11.)(111.)It is well established that 1 : 2-dihydroisoquinoline derivatives arereadily susceptible t80 oxidation and reduction ; pavine, on the con-trary, is stable towards oxidising and reducing agents, so thaton this ground it is possible to exclude the first formula fromconsideration. This leaves a choice between I1 and 111. Nowwhen Hofmann’s degradation method was applied to $-methyl-pavine methohydroxide, C,zH,80,N*OH, the first product on boil-ing with conce’ntrated aqueous potassium hydroxide was foundto be the corresponding methine, C,,H,70,N, and oxidation of thissubstance with aqueous potassium permanganate produced a dicarb-oxylic acid, C,,H2,0,N, a reaction which points t’o the presence ofthe group *CH:CH* in the methine.Further, since there has beenno loss of carbon atoms during the oxidation, i t is clear that theunsaturated grouping is not essential to the coherence of themolecule.Them facts cannot be brought into accordance with formula 11,for if pavine had a structure of this type, N-methylpavine metho-hydroxide would have, the formula IV and might form either ofREP.-VOL. XII. 162 ANNUAL REPORTS ON THE PROCIRESS OF CHEMISTRY.the metliines represented by V and VI, neither of which couldyield a dibasic acid on oxidation without the loss of carbon:Psvine must therefore have the structure represented in 111, andits me'thine can be represented by VII, which would readily yieldthe required dicarboxylic acid :CH,*C,H,(OMe)2,?<NMe, )\pH C'H(VII. )Further evidence in support of this view is obtained from thebehaviour of the methine methiodide towards water and methylalcohol, whereby trimethylamine hydriodide is readily eliminated,a reaction which tends to show that the grouping *NMe,I isattached to the carbon atom of a negative group-in this case thebenzene nucleus.The synthesis of alkaloid derivatives of high molecular weight 67has been studied in the condensation of papaverine with form-aldehyde and with opianic acid in the presence of sulphuric acid.Opianylpapaverine and methylenedipapaverine have thus beenproduced, but the only point of interest in the work appears tolie in the fact that the methylenedipapaverine thus formed differsfrom that obtained when no sulpliuric acid is present.68I n the hydrastine group very little work of interest has beendone during the present year.A new synthesis of hydrastininederivatives 69 by the condensation of homopiperonylamine com-pounds of the type CH,:0,:C,H3*CH,*CHAlk*NR*CH0 (whereR=hydrogen, alkyl, or arylalkyl) has been patented, and a some-67 M. Freund and K. Fleischer, Ber., 1015, 48, 406; A., i, 449.68 W. Iionigs, ibid., 1899, 32, 3599; A . , 1900, i, 189.69 E. Merck, D.R.-P. 279194; A., i, 709ORGANIC CHEMISTRY. 163what analogous method70 has been applied to the1 preparation ofhydrohydrastinine and its homologues.I n the morphine group, the main progress of the year has beenmade in the increase of our knowledge of the action of aceticanhydride on the morphine derivatives.71 It has been shown thatthe morphine series can be separated into three classes accordingto the effects of the action of acetic anhydride on the variousmembers.Morp hothebaine, apocodeine, apomorphine and itsderivatives behave, in the presence of acetic anhydride, in a manneranalogous to the tertiary benzylamines ; fission of the moleculesoccurs a t the nitrogen atoms. A double fission a t the nitrogenatom and also a t a carbon atom takes place in the case of thebaine,codeinone, and $-codeinone. The members of the third class ofcompounds, which comprises codeine, morphine, thebainone, andphenyldihydrothebaine, undergo no change in structure.Tiffeneau suggests that the action of acetic anhydride takesplace in two successive stages in those cases where fission occurs;the first step is the addition of the anhydride t o the tervalentnitrogen atom, whilst the subsequent fission is to be attributed tothe instability of the grouping containing quinquevalent nitrogen.This view is supported by the fact that when polarimetric read-ings of thebaine in the presence of acetic anhydride are taken, thereis a marked falling off in the lzevorotation during the first twenty-four hours.A t this stage, treatment with water regenerates theoriginal alkaloid from the additive product, but if the reaction isallowed to proceed further, fission occurs.A very careful examination of the reactions of dihydro-berberine 72 has been made, but neither the experimental work noreven the arguments deduced from the results can be summarisedhere without occupying much more space than could be spared.Those who are interested must therefore read the eighty-page paperfor themselves.The current year has been marked by the closer investigation ofcertain of the less known members of the alkaloid group, andalthough the results in most cases have not sufficed to throw adefinite light on the constitutions of these substances, none theless they seem worthy of mention here. That interesting sub-stance, yohimbine (or quebrachine), h a been subjected to a mostcareful examination, with the following results.73 It appears to70 E.Merck, D.R.-P. 280502; A., i, 710.71 M. Tiffeneau, Bull. SOC. chim., 1915, [iv], 17, 67, 109; M. Tiffeneau andPorcher, ibid., 114; A., i, 448-9; compare also M. Freund and E. Speyer,Ber., 1915,4$, 497; A., i, 560.72 M. Freund and K. Fleischer, Annulen, 1915, 409, 188; A., i, 982.73 G. Barger and Miss E. Field, T., 1915,107, 1025.a 164 ANNUAL REPORTS ON THE PROGRESS 9 F CHEMISTRY.have the composition C,,H,O,N, and contains one methoxy-group.It is a monacidic tertiary base and forms a methiocdide whichcrystallises with one molecule of water. When brominated inchloroform solution, i t combines with a molecule of bromine with-out any evolution of hydrogen bromide, producing the hydro-bromide of monobromoyohimbine, whilst further bromination ofthis substance yields the hydrobromide of dibromoyohimbine.Both bromo-derivatives, like the methiodide, contain a molecule ofwater more than the base itself.Yohimbine, wnen treated withconcentrated sulphuric acid, yields a sulphonic acid, and this fact,taken in conjunction with the results of bromination, appears t opoint to the presence of one benzene ring in the yohimbine mole-cule. The possibility of a second benzene ring being presentappears to be excluded by the high hydrogen content of the base.Oxidation of yohimbine has not led to any very marked advancein our knowledge, although various reagents were tried. Degra-dation of the alkaloid by means of soda-lime led to the isolationof a substance which appears to be an indole derivative, andanother compound which seems to contain a pyridine ringassociated with a benzene nucleus.The problem of aconitine74 has again been attacked in the lasttwelvemonth, but the results do not carry us much beyond whatwas already known, although a new method of oxidation has beendevised which produces oxonitin in yields much higher than havehitherto been obtained.The older method consisted in decorn-posing aconitine permanganate with sulphuric acid, but it nowappears that considerable loss occurs owing t o the hydrolysis ofthe permanganate by the sulphuric acid employed in the reaction.When the method is modified by using permanganate in acetonesolution and employing glacial acetic acid, the reaction gives a90 per cent.yield of oxonitin.Further investigations of the angostura alkaloids have beencarried out, the nature of isocusparine being the object in view,75but the results do not lend themselves t o summarisation here.The degradation of colchicine 76 has been investigated, with thefollowing results. When oxidised with hot potassium perman-ganate solution, the alkaloid yields a trimethoxy-o-phthalic acidthe nature of which is determined from the fact that it producesgallic acid when it is boiled with hydriodic acid. The action ofnitric acid on colchicine produces a mixture of succinic, oxalic,?* G. Barger and E. Field, T., 1915,107, 231.75 J. Troger and W. Muller, Arch. Pharm., 1914, 252, 459; A., i, 459.76 A. Windaus and L.Krellwitz, Sitzungsber. Heidelberg. Akad. Wiss. Math.Naturw. Klasse., [ A ] , 1914, 18; A., i, 708ORGANIC CHEMISTRY. 165and picric acids, whilst thO two1 aliphatic acids are obtained fromcolchicinic acid by treatment with potassium permanganate.Fusion with potassium hydroxide and subsequent oxidation withhot potassium. permanganate converts colchicine into terephthalicand trimellitic acids, and the same compounds are obtainable fromcolchicinic acid by simple fusion with alkali. This tends to showthat colchiciiie contains a pyrogallol ring and, in addition; a secondring which yields terephthalic and trimellitic acids on fusion withalkali. The action of iodine on an alkaline solution of colchicineresults in simultaneous substitution and oxidation, with the resultsexpressed in the following equation : C,,H,,O,N + 4HI + 5NaOH =@20H220,NI + 3NaI + Na,CO, + 3H,O.The new substance does notgive the ferric chloride reaction of colchiceine, nor is this reactionobserved even after the iodine atom has been removed from thenucleus.The study of the alkaloids contained in Turkish tobacco has ledto definite results.77 Four substances have been isolated : nicoteine,isonicoteine, nicotoine, C8HllN, and nicotelline. isoNicoteine,Ci,Hi2N,, shows reactions which point t o its having the followingstructure :The pareira root alkaloids have been examined,7* but the resultsdo not seem suitable for condensed description. Eserine, derivedfrom the Calabar bean, has been studied and several of its deriv-atives have been prepared.79 A new alkaloid of the bean,g e n e ~ r i n e , 7 ~ ~ has beea isolated, and its reactions have been care-fully examined.Another new member of the alkaloid class,struxine, has been discovered in samples of nux vomica which hadbeen subjected to the ravages of insects and had become partlydecomposed owing t o prolonged exposure on wet fields.60 It issupposed to be a decomposition product of strychnine o r of brucineunder the conditions of fermentation or oxidation which had pre-vailed in the previous history of the beans in which it was dis-covered. Sempervirine, a third alkaloid from gelsemium, has beenisolated and examined; but the results are merely in the pre-liminary stage, and reference must be made to the original paper77 E.Noga, Chem. Zentr., 1915, i, 434; A., i, 711.78 M. Scholtz and 0. Koch, Arch. Pharm., 1914, 252, 513; A . , i,79 M. Polonovski, Bull. Xoc., Chim., 1915, [iv], 17, 235; A., i, 891.79n M. Polonovski and C. Nitzberg, Bull. SOC. Chim., 1915, [iv], 17,244, 290 ;8o H. H. Schaefer, Pharm. J . , 1915, 94, 241; A., i, 86.450.A . , i, 892, 987166 AKNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.for fuller information.81 Channa,82 describ,ed as ‘‘ a delicacy ofthe Hottentots,” has been found t o owe its interest t o the alkaloidmesembrine, C16H,,0,N, the action of which is said to resemblethat of cocaine, although i t is distinct from that drug.Chlorophyll.I n last year’s Report the decline in interest with regard tochlorophyll was noticeable, and during the current year very littlefresh information has been acquired in this field.A summary ofour knowledge on this and allied topics is to be found in a paperby Willstatter,83 but as the matt,er has been very fully dealt withduring previous years, i t seems unnecessary to go over the groundagain in this place.The fluorescence of different varieties of chlorophyll has againbeen examined,84 and the results in the main concord with whathad already been published on the subject. The chlorophyll ofgreen plants is apparently composed of two fluorescent substances,( a ) having a band a t h68-65.5, whilst ( b ) has a band a th65.8-65.3. On the other hand, the chlorophyll derived fromPhaeophyceae, Diatornaceae, and Hydrurus is quite different. I nthO living state it shows only one band (that of a ) , whilst whendead it gives a second band, a t 64*0-63*0, which is quite distinctfrom that of b , and apparently may correspond with the chloro-phyll constituent c, the existence of which seems t o be in doubt.A physiological theory of the action of chlorophyll has beenput forward by Ivanovski,85 and this author considers in turn theinfluence which the different pigments of plants exert during thevital processes.The original paper should be consulted for thedetails.More purely chemical is another investigation,86 in which thevarious pigments occurring in the green leaf have been separatedand the action of light on each of them has been studied. It isfound that when chlorophyll, xanthophyll, and carotin are exposedto light in presence of excess of oxygen, they may act as oxydases,not only t o themselves, but also t o other substances, such as litmus,hydriodic acid, or guaiacum.It is therefore unnecessary to assume81 A. E. Stevenson and L. E. Sayre, Pharm. J . , 1915, 94, 159; A., i,82 C. Hartwich and E. Zwicky, Apoth.-Zeit., 1914, 29, 925, 937, 949, 961 ;83 R. Willstatter, Ber., 1914, 47, 2831 ; A., i, 289.84 A. Wilschke, Zeitsch. wiss. Mikroscop., 1915, 31, 338; A . , i. 829.8 5 D. Ivanovslii, Ber. Deut. bot. Ges., 1914, 32, 433; A., i, 705.A. J. Ewart, Proc. Roy. SOC., 1915, [B], 89, 1 ; A., i, 706.85.A . , i, 710ORGANIC CHEMISTRY. 167that peroxides are formed during the photo-oxidation of thesepigments.Chlorophyll and xanthophyll decompose during photo-oxidation into formaldehyde and certain waxy solids which containoptically active hexoses. The results vary according as the atmo-sphere is moist or not. I n dry air free from carbon dioxide thereaction tends to produce relatively more formaldehyde and lesssugar, whilst the reverse is found when moisture is present.Carotin oxidises more rapidly than either chlorophyll or xantho-phyll, and the end-products in its case are a small amount offormaldehyde and much colourless, waxy, solid material.Chlorophyll combines with carbon dioxide5 with the formation ofxanthophyll and a waxy solid. This reaction takes placevigorously in sunlight when water is present. Oxygen is evolved,and this in sunlight.may oxidise the xanthophyll t o formaldehyde,sugar, and the phytyl radicle, from which chlorophyll may againbe built up.Xanthophyll can readily be converted into carotin by the actionof magnesium powder or zinc dust in water; the reaction proceedsin the dark.These results show that the assimilation of carbon dioxide bythe plant is a very complex process. Chlorophyll and xanthophyllboth play their part in the reactions; the equilibrium between theproducts and the reacting substances determines the direction ofthe reaction, and light has a strong influence.One of the most suggestive researches on the chlorophyll problemhas resulted in the synthesis of a pigment which appears t o presentmany of the properties shown by natural chlorophyll.87 Thematter is so important that a detailed description of the resultsseems justified. Chlorophyll might be regarded as a productformed by the oxidation and polymerisation of aniline accordingto the equationGPhNH, + 150 = C3,H3,04N + 6H20 + 5N0.Now, when nitrous acid is added drop by drop to a very concen-trated solution of aniline in alcohol, a white deposit is formedwhich turns rose-coloured. Heat is then developed, energeticeffervescence takes place, and the deposit becomes green. A t theend of the reaction the walls of the vessel are found to be coatedwith a green o r reddish-brown substance, and a dark residue isfound a t the bottom. By shaking with benzene, a green, fluores-cent solution is formed, which becomes red on exposure to air andlight. A brown precipitate forms which has the properties ofPringsheim’s hypochlorin. I f the benzene solution is evaporated8’ Albert and A. Mary, Mon. Sci., 1915, [v], 5, 121 ; A., i, 979168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in the dark, dichroic crystals are formed, which are said t o besynthetic chlorophyll.The reaction may be altered by the addition of sodium hydrogencarbonate to the solution when it becomes green. All the colour-ing matter can t,hen be extracted by means of benzene, but thesolution under certain conditions has the colour of dead leaves.It. is claimed that the colour changes which chlorophyll undergoesin nature can thus be artificially brought about in the course ofa few minutes. Similar colour reactions can be produced withnatural chlorophyll.It must be frankly admitted that if these results prove t o beaccurate, they will revolutionise the whole of our views on chloro-phyll and will invalidate all the work which has been done inrecent years; for, since no magnesium is present in the reactingsubstances, no magnesium atom can be essential to the productionof chlorophyll, and consequently the whole of Willstiitter’s con-clusions wovld go by the board a t a stroke. It is as yet too earlyto pronounce definitely on the question, but further results will beawaited with considerable anxiety.The Bile a d Blood Pigments and their Allies.The chemistry of the bile pigments has of recent years becomeone of the most perplexing and confusing of all the subjects in-cluded in the present section of the Annual Reports, and i t seemsalmost too much to hope that’ we are approaching a solution ofthe difficulties which confront investigators in this branch of thesubject. Data which appear to be fairly based on accurate experi-ment turn out next year t o be erroneous, and the final stage ofthings seems to be even worse confounded than the crudebeginnings. To add to the difficulties of the Reporter, the variousinvestigat-ors delight in acute controversy, and polemical papersabound. During the past year the work in this division of chem-istry has consisted f o r the most part of scattered researches whichcannot be welded into a consecutive narrative, so that it seemsbest in this place t o give short summaries of the various investi-gations without attempting to follow the matter into any greatdetail.mesobilirubin, and mesobilirubinogen 80 have beensubmitted to further examination, and some new reactions havebeen recorded. The authors have prefaced their papers by Rsummary of their previous work so as to assist the reader. Certainphenomena point t o the possibility that bilirubin is a mixture of88 W. Kiister, Zeitsch. physiol. Chern., 1915, 94, 136; x4., i, 829.89 H. Fischer, Zeitsch. Biol., 1014, 65, 163; A . , i, 148ORGANIC CHEMISTRY. 169two modifications, and that a solvent may disturb the equilibriumbetween the two. The substance now termed mesobilirubinogeiiis what used to be called hemibilirubin. This continual shiftingof nomenclature is by no means the least of the troubles whichbeset those who wish t o read up the subject. When heated witha 10 per cent. solution of potassium methoxide a t 150°, mesobili-rubinogen is converted into mesobilirubin, but if the temperatureis raised to 170° the reaction takes a different course and xantho-bilirubic acid is also formed. A further rise in temperature to190° results in a better yield of the acid. Mesobilirubin can beconverted into mesobilirubinogen by the act.ion of sodium amalgam,but biological methods do not seem capable of producing thischange.Some work has been done on the constituents of gall-stones.90A paper on hzematoporphyringl is largely taken up with con-troversial matter, and delfinite data bearing on the crucial pointsa t issue are not available. Arguments are adduced againstWillstatter’s views, and certain experimental evidence is broughtforward with the idea of disproving his conclusions. The con-troversy appears t o centre about the existence of auxiliaryvalencies in the hzmin group, and as there appears to bel consider-able doubt as t o whether or not such things exist a t all, i t seemsbest to leave the matter until better evidence is obtainable.Anot\her speculative paper 92 containing a summary of previouswork on the subject has been published on hzmopyrrole. It alsotreats of the possible constitution of hzmin. The extraordinarydifficulty of work in this branch of the subject is well exemplifiedby the fact that a substance originally called phyllopyrrole, andthen rechristened haemopyrrole-d, is now found to contain a secondcompound, which has received the name haemopyrrole-g, and isprobably 2 : 3-dimethyI-4 : 5-diethylpyrrole. Phonopyrrolecarboxylicacid-a can be converted into the picrate of hEmopyrrole-b, andsince the constitution of the latter is known, i t is possible to deducethe structure of phonopyrrolecarboxylic acid-a, which is apparentlyMe :C Me >C*CH,*CH,*CO,H. NH--CHNow, since the oximes of phonopyrrolecarboxylic acid-b and phono-pyrrolecarboxylic acid-a are isomeric, and both give the samehzematic acid, it follows that phonopyrrolecarboxylic acid-b (some-times called isophonopyrrolecarboxylic acid) must be 2 : 5-diniethyl-W. Kiister, Zeitsch. physiol. Chew,., 1915, 94, 163; A . , i, 831.91 W. Kiister and H. Bauer, ibid., 172; A., i, 853.92 0. Piloty, J. Stock, and E. Dormann, Annulen, 1914,406, 342 ; A., i, 451.G170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTKY.pyrrole-4-P-propionic acid. Since phonopyrrolecarboxylic acid-c(also called xanthopyrrolecarboxylic acid) gives the same oxinie andthe same hzematic acid as plionopyrrolecarboxylic acid-b, i t isassumed that it is probably 3-metliyl-5-ethylpyrrole-4-~-propionicacid. Phonopyrrolecarboxylic acid-d is supposed t o be 2 : 3 : 5-tri-methylpyrrole-4-P-propionic acid. These four acids are obtainedby the action of hydrogen iodide on hzemin in glacial acetic acid.Q3I n the same paper it is pointed out that hzemopyrrole-e cannotbe 2 : 3-dimethyl-l-ethylpyrrole, because a pyrrole derivative ofthis structure has now been synthesised, and it is found that itspicrate differs froin that of hzmopyrrole-e.Another polemical paper 94 contains, in addition to controversialmaterial, an account of certain experiments on the condensationof glyoxal with members of the pyrrole series, whilst still anothercontribution95 is largely taken up with a claim f o r priority,although it also describes the formation of some dipyrrylmethanederivatives by the interaction between pyrrole compounds, chloro-form, and alkali.Annual Reports are by their very nature somewhat lacking incoherence, but in former years the Reporter has been able t ocomfort himself with the idea that he has a t least drawn attentionto one or two outstanding lines of research and has sketched theirprogress in its broad outlines. I n the foregoing Report he is onlytoo conscious that such sections are conspicuous by their absence.The study of the heterocyclic compounds during the last twelvemonths has not produced any researches which in themselves canbe termed epoch-making, and with the best will in the world onecannot make bricks without straw. It would, however, be a mis-take to suppose that this indicates a failure of research in thefield a t the present time. Annual Reports are only a by-productof chemical investigation, and the fact that a Report is somewhatdry should not suggest that the subject is bankrupt. I n the caseof the present year, much useful knowledge has been added to ourstock, and if the researches of the p a s t twelve months have notpresented anything of a spectacular nature they have laid a verysound foundation for work in the future.A. W. STEWART.93 It seems desirable to note that the formation of the oximes referred toabove is not a direct reaction, since none of the acids contains a ketoniccarbonyl radicle.94 H. Fischer, Ber., 1914, 47, 3266; A., i, 309.96 0. Piloty, W. Krannich, and H. Will, ibid., 2531; A., i, 461

ISSN:0365-6217    

DOI:10.1039/AR9151200063

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.COMPARED with other years, 1915 saw scarcely any diminution inthe number of papers relating to analytical chemistry, but, as mightbe expected, many well known names will be absent from thisyear's index, their owners being engaged o,n work of more immedi-ate importance than analytical research. Of the papers published,a much smaller proportion than usual are suitable for mention inthis Report, which will, in con::,equence, be short compared withthose of other p a r s .Physicnl A izalysis.The incidence of cathode rays on certain salts produces immedi-ately vivid colours on the salts, which in the dark and a t low tem-peratures may persist in some cases for many years. Thus sodiumchloride becomes amber-coloured, potassium chloride violet, potass-ium bromide deep blue, sodium fluoride rose, lithium chloridebright yellow, and potassium carbonate red.The colours are sensi-tive to heat in very different degrees; for instance, that of sodiumchloride is comparatively stable, but those of potassium chlorideand bromide disappear even a t tropica.1 temperatures. The disap-pearance oi colour in daylight is generally accompanied by theappearance of marked fluorescence. Similarly, solid solutions ofthese salts even in extreme dilution, in substances such as potassiumor sodium sulphate, which are not themselves affected by cathoderays, also acquire characteristic colours, generally different fromthe colour given by the pure substance. Thus, one part of potassiumcarbonate in 25,000 parts o r more of the sulphate produces a greencolour, whilst in some cases quantities of an admixture estimatedat one part in on0 million, may produce a perceptible tint.Thesereactions afford a very sensitive method for detecting impuritiesin salts, even when more than one impurity is present, since thecolours pro'duced by different impurities generally disappear a tdifferent sates in daylight- or on increasing the temperature.Potassium sulphate, f o r example, generally turns dark grey a tfirst, owing to the presence of a trace of sodium chloride, but thislil G* 172 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.colour disappears in a short time in daylight, leaving only a vividgreen due to the carbonate. Since the colorations produced bydifferent salts of the same metal vary so much, i t is probable thatthey are due primarily to the acidic group.This assumption isstrengthened by the fact that the halogen derivatives of aceticacid are coloured by the cathode rays, whilst acetic acid itselfremains colousless. These phenomena are probably accounted forby a decomposition, notb however, of the ordinary kind in whichthe components are entirely set free, but merely a ‘‘ distention,” thecomponents remaining a t a short distance from one another, and,if the absorptive power is weakened by heating, o r the chemicalaffinity strengthened by the energy of daylight, recombinationagain ensues. The effects of cathode rays and P-rays are reallythe effects of the ultra-violet light produced by the stopping ofthose rays, and hence ultra-violet light also produces similar coloureffects on salts.1Using a fluorescence microscope, nearly a hundred differentsubst’ances have been examined in ultra-violet light, and morethan a third of them are found to fluoresce!.It is suggested thatthe fluorescence of arsenic trioxide, sodium uranyl acetate, sodiumpyrantimoniate, silver and mercurous haloids may prove useful inqualitative analysis.2Only a single paper need be cited in connexion with the use ofthe interferometer for the analysis of solutions. I n this paper theremarkable claim is made that a mixture1 of potassium and sodiumsulphates can be analysed by this means with an accuracy evengreater than that attainable by the most careful gravimetric work.3The ease and rapidity of the method were long since demonstrated.A new method for the estimation of acidity has been based onthe observation that the addition of a strong capillary-inactive acid(a strong acid which, on dissolving in water, does not lower thesurface tension of the1 solvent) tot the capillary-inactive salt of aweaker capillary-active acid sets the weak capillary-active acid freeand causes a lowering of surface tension, from which the quantityof strong acid added can be calculat’ed.4 Alkalis are similarlyestimated by the lowering of the surface tension of solutions of thesalts of alkaloids with strong acids.5The1 method for the determination of hydroxyl-ion concentration,6based on the velocity of hydrolysis of nitrosotriacetonamine, has1 E.Goldstein, Rep. Brit. ASSOC., 1914, Chern. News, 1915, 111, 27.3 L. H. Adams, J. Amer. Chem. Xoc., 1915, 37, 1181; A . , ii, 478.4 I. Trauke and R. Somogyi, Inter. Zeitsch. Phys.-chem. Biol., 1914, i,6 Ann. Report, 1913, 162.W. Lenz, Zeitsch. anal. Chem., 1915, 45, 27; A., ii, 275.479; A . , ii, 101. I. Traube, Ber., 1915 4.8, 947; A , , ii, 571ANALYTICAL CHEMISTRY. 173been so modified that its accuracy has been much increased withbut slight increase in the time necessary to compleh a determina-tion. A serious defect of the nitrosotriacetonamine method was thefact$ that between concentrations of 0.05N and 0.3N the unimole-cular constants " drifted," and the method was consequentlyinapplicable within those limits.By the use of nitrosovinyldi-acetonamine or nitrosoisobutyldiacetonamine, however, it has beenfound possible to bridge this region of ionic concentration, and themebhod in one or other of its modifications se'rvw to determineall values of hydroxyl-ion concentration.7Inorganic A?2nlysis.Qualitative.-A few qualitative tests are deserving of notice.For the detection of white phosphorus in matches a mor0 sensitiveand more rapid test than that of Thorpe has been devised. Itdepends on the volatility of white phosphorus with steam and itsluminescence in contact with oxygen, and will detect 0.1 mg. sus-pended in 10 C.C. of water.* Ilinski and Knorre's reagent for cobalt(u-nitroso-j3-naphthol)9 has never been much used as it is veryunstable, and, in certain circumstances, untrustworthy. It hasnow been shown that the sodium salt of the oxime is much morestable in solution, and that it will readily detect less than one partof cobalt in one million parts of water.Only large quantities ofnickel interfere, and it is easy to precipitate the bulk of the nickelby means of dimethylglyoxime or u-benzildioxime.10 F o r manypurposes the flame test for sodium is too sensitive. Most othermethods are troublesome. A method has recently been described,depending on the separation of poltassium perchlorate or boro-fluoride and detection of sodium by the insolubility of the silico-fluoride in alcohol. An advantage of t'he method is that the previousseparation of magnesium, a troublesome operation, is unnecessary.Lithium does not inte'rf ere.11&uantitatiue.-Fox the titration of small quantities of hdoidsVolhard's method is not entirely satisfactory, requiring one dropof N / 10-solution to determine the end-point,.A method dependingon the far more de'licate reaction between iodine and starch, usingAT /SO- or N / 100-potassium iodide for titrating back the excess ofsilver, has been found much more satisfactory. The haloid isF. E. Francis, F. H. Geake, and J. W. Roche, T., 1915,107, 1651.E. R. Phelps, V.S. Hyg. Labor., Bull. 96, 51 ; A., ii, 65.Ber., 1885, 18, 699.lo F. W. Atack, J. SOC. Chem. Ind., 1915, 34, 641; A . , ii, 652.l1 F. C. Mathers, C. 0. Stewart, H. V. Houseman, and 1. E. Lee, J . Amer.Chem. SOC., 1915,37, 1915; A., ii, 5801’74 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.precipitated in the presence of a known amount, of free nitric acidwith excess of AT/50-silver nitrate, the precipitate is coagulated byshaking with a few drops of octyl alcohol, the mixture filtered, andthe filtrate mixed with a mixed reagent containing sodium nitriteto liberate iodine, starch, and a sodium salt of a weak acid inamount equivalent t o the nitric acid present.The mixture is thentitrated with A7/50- o r N / 100-potassium iodide.12As the result of a critical examination of the most generallyapproved methods for the analysis of hypochlorite solutions,Bunsen’s original method, namely, delivery of the bleach liquorinto an excess of potassium iodide solution, addition of acetic acid,and titration of the liberated iodine with thiosulphate, is found tobe unapproached in accuracy or in speed by any more recentmethod.That the method has tended to give way to Penot’smethod, or t o Mohr’s more convenient modification of it, is mainlydue to the fact that these methods are more economical of iodideand make use of solutions the titre of which remains constantfor long periods. The latter characteristic constitutes such a realadvantage that Mohr’s method of adding excess of arsenite andtitrating the excess with standard iodine is likely to remain in usein many laboratories. If i t is recognised that the method is empiri-cal and not exact and a suitable correction is applied, results of avery satisfactory degree of accuracy can be obtained.13I n the Annual Report for 1912 the attention of agriculturalchemists was drawn to Brearley and Ibbotson’s lead molybdatemethod f o r the estimation of phosph0rus,~4 a method long in usein steel works, but one that has become known only slowly t oworkers in other fields.It is satisfactory to be able to record thatthe method has now been applied with success t o the estimationof rr inute quantities of phosphorus in physiological material15A new and rapid method for the estimation of nitrates (andnitrites) depends on the fact- that they are reduced to ammoniaquantitatively and almost instantaneously by titanous hydroxide.16A new and rapid, yet accurate, method for the estimation oflead depends on separation as sulphate, decomposition of thesulphate by melans of hydrogen sulphide, and titration of theliberated sulphuric acid.17 It is more accurate than Alexander’s12 F.C. McLean and D. D. Van Slyke, J . Amer. Chem. SOC., 1915,37, 1128;A . , ii, 479.13 M. L. Griffin and J. Hedallen, J . SOC. Chem.. I n d . , 1915, 34, 530; A . ,ii, 551.l5 H. S. Roper, Biochem. J . , 1914, 8, 649; A . , ii, 66.16 E. Knecht, J . SOC. Chem. Ind., 1915, 34, 126; A . , ii, 105.l7 F. D. Miles, T., 1915, 107, 988; A., ii, 651.l4 Ann.. Report, 1912, 219ANALYTICAL CHEMISTRY. 175original molybdate method and quicker than Low’s modificationof it.18Of more importance, perhaps, than any new method for theestimation of copper is a report of the Sub-committee on Methodsof Analysis of Non-Ferrous Alloys of the American ChemicalSociety.It embodies methods generally accepted in the UnitedStates for standard analysis by both producers and consumers ofcopper and copper products.19 F o r the analysis of electrolytic andlow resistance copper the method recommended is essentially thatof Heath.20 F o r lower grades of copper special methods aredescribed which circumvent the difficulties introduced by the com-moner impurities of commercial copper, whilst keeping the tech-nique as simple as possible. A new modification of the iodinemethod depends on the action of sodium fluoride on acid solutionsof ferric salts, with the iron of which it forms a stable compound,Fe2FG, preventing any subsequent reaction between these1 salts andpotassium iodide.The method is applicable to all kinds of cuprousmaterials from low-grade ores to regulus, and, although onlyrecently published, has been in daily use for fifteen years, duringwhich its results have been repeatedly checked by refined modifica-tions of the electrolytic method.21 According to another newmethod, cupric solutions are titrated with a standard solution ofsodium nitroprusside, the end-point being found by a spotting testwith an alkaline sulphide applied to a few drops of the filteredliquid. Neither ferric salts, zinc, alkaline earth metals, manganese,aluminium, tin, nor lead intlerfere.22 A method f o r the estimationof cuprous and cupric sulphides in mixtures of both has beenbased on the fact that cuprous sulphide reacts with silver salts, withthe formation of equivalent amounts of metallic silver and silversulphide, whilst under similar conditions cupric sulphide gives riseonly to silver sulphide.23 For the estimation of copper in steel, amethod has been described depending on precipitation as thio-cyanate, treatment of the waahed precipitate with a measuredquantity of potassium iodate solution of known titre, and estima-tion of the excess of iodate by addition of potassium iodide andtitration with thiosulphate.The relation 7KI0, = 6Cu is all thatis necessary t o calculate the results, but the reactions involved aresomewhat intricate, and may be stated as follows:“ Technical Methods of Ore Analysis,” 1911, 149.l9 W. B. Price and others, J.Ind. Eng. Chem., 1915, 7, 546.2o Ann. Report, 1911, 168.21 A. Fraser, J. SOC. Cltem. Id., 1915, 34, 462; L4., ii, 582.22 G. Zuccari, Ann. Chint. Applicata, 1914, 2, 287; A., ii, 68.23 E. Posnjak, J. Amer. Chem. SOC., 1914, 36, 2475; A., ii, 24176 ANSUAC REPOKI'S ON THE PROGRESS OF CHEMISTRY.4CuCNS + 7KI0, + 14HC1=4CuS0, + 7IC1+ 4HCN + 7KC1+ 5H,O . . (1)7IC1+7KI=141+7KCl . . . . * (2)KIO, + 5KI + 6HC1= 6KC1+ 3H,O + 61 . . . (3)Equations (1) and (2) show that 7KI0, oxidises 4Cu with forma-tion of 7IC1, which, on dilution and treatment with potassiumiodide, liberate 141, o r KI03=21, whereas each molecule of iodatein excess of that required by the copper liberates 6 atoms of iodinein accordance with the familiar equation (3).Therefore, one-thirdof the oxidising power of the potassium iodate taking part inreaction (1) is reclaimed on addition of iodide, and the net con-sumption of iodate by copper is given by the relation 4Cu=3 of7KI0, o r 6Cu = 7K10,.24A method for the estimation of aluminium in the presence ofof iron has been based on the fact that aluminium chloride is pre-cipitated completely as the hydrated compound, A1,C1,,6H2O, whenits concentrated solution is mixed with a solution of 1 part ofacetyl chloride in 4 parts of acetone, ferric chloride remainingsoluble under these conditions.25 An excellent colorimetric methodfor the estimation of small quantities of aluminium (0.005 to 0.05mg. in 10 c.c.) depends on the use of alizarin (red) S, the sodiumsalt of alizarinmonosulphonic acid.The coloured compound is nota lake, but the aluminium salt of alizarin S. One part ofaluminium can be detected in 10 million parts of water, and themethod is as nearly quantitative as a colorimetric method can be,even when iron and chromium are present in amounts 1000 timesgreater than the amount of aluminium.26 The work of Dittrichand his collaborators in reducing the uncertainty of the end-pointin the titration of ferrous iron in silicate rocks after decompositionof the rock by means of hydrofluoric acid27 has been carried furtherby Barnebey, who shows that the1 most' convenient reagent forarresting the tendency of the pink colour t o disappear, when thetitration with permanganate should be complete, is boric acid,which has the added advant,age that ferrous borofluoridel is remark-ably stable towards atmospheric oxygen (air bubbled through thesolution for an hour does not lower its titre), whereas ferrousfluoride is very unstable.Moreover, in the presence of boric acidthe customary manganese phosphate solutions may be used tocounteract the influence of hydrochloric acid if simultaneouslypresent, whereas in absence of boric acid either manganese salts24 TV. D. Brown, J . Ind. Erbg. Chem., 1915, 7, 213; A . , ii, 284.25 H. D. Minnig, Amer. J . Sci., 1915, [iv], 39, 197; A., ii, 107.26 F. W. Atack, J . SOC. Chem. Ind., 1915, 34, 936; A., ii, 842.27 Ann. Report, 1911, 165ANALYTICAL CHEMISTRY. 1’77or phosphates tend to make the end-point very uncertain if hydro-fluoric acid is present.28The accurate analysis of commercial zinc has assumed increasedimportance with the phenomenal rise in the price of spelter dueto the war.No new methods of importance have been described,but a most valuable report has been issued by a Sub-committee onNethods of Analysis of Non-Ferrous Alloys of the AmericanChemical Society. The methods recommended are those actuallyin use in the laboratories of the more important producets andconsumers of zinc in the United States. They include an eledro-lytic method for lead as well as a very accurate, yet simple, modifi-cation of the sulphate method, a method for cadmium dependingon the separation of pure cadmium sulphide, which is subsequentlyconverted into, sulphate and weighed, an alternative electrolyticmethod for cadmium, and directions for the exact estimation ofvery small quantities of iron by means of N / 100-permanganate.29I n the Annual Report on Analytical Chemistry, 1912, the writermade a very strong claim for the recognition of the perchloratemethod, especially the modification of this due t o W.A. Davis, asthe most accurate method available for the estimation ofpotassium.30 Thin and Cumming have since cited the writer assharing the view that the perchlorate method falls short of exact-ness. It does, like most human efforts, and in 1912 the writerwas unwilling to put his case too high, especially as he was publiclycastigating a great Department of State for perpetuating the useof the costly, troublesome, and less accurate platinum method.Most of Davis’s results published in 1912 were obtained before heeffected his final improvement in the method, namely, washing theprecipitate with alcohol saturated with potassium perchlorate, butthis improvement was fully described in Davis’s original paper, andhas been followed by Davis and his collaborators a t Rothamsted,by the writer, and many others ever since.Thin and Cumminghave done good service in showing that this final improvement ofDavis reduces the error of the method to less than 0.5 mg.31Perhaps now the Board of Agriculture may begin to considerwhether the use of this method for official purposes should bepermissive.The year has witnessed the appearance of a most important paperon the analysis of platinum.Although an unusually good andlong abstract appeared in the Journal, no one interested in this0. L. Barnebey, J . Amer. Chem. SOC., 1915,37, 1481; A . , ii, 583.W. B. Price and others, J . Ind. Eng. Chem., 1915, 7 , 457.R. G. Thin and A. C. Cumming, T., 1915,107, 361; A., ii, 281.3O Ann. Report, 1912, 217178 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.subject can do less than study the original paper.32 Fortunately,since German journals are accessible t o few just now, the wholepaper has been translated and pubiished in English.33 It dealswith the detection and estimation of all the ordinary constituentsof commercial platinum in great detail. Fourteen qualitativereactions of each of the six platinum metals in 0.1 per cent.solu-tion are tabulated, the method of carrying out colorimetric estima-tions with solutions of the chlorides in presence of hydrogenchloride is described, and a siniple process for the analysis by pre-cipitation of dissolved platinum alloys is recommended. Thebehaviour of ruthenium chloride towards ammonium chloride isexplained by means of new experiments, and the existence ofiridium mercaptide proved. Methods of separating the platinummetals from one another have been tested and improved, and aspecial method is proposed and described in detail for the quanti-tative analysis of technical platinum. Finally, for the detectionof impurities in high-grade platinum, a method is described as asupplement to that recommended by Finkener, and tested byMylius and Forster, for the precipitation of the metal.Few papers have been published this year on the separation ofthe rare earths. One may be cited.I n i t experiments aredescribed which show that fractional electrolysis of mixtures ofthe rare earths yields quite rapid separations in some cases, andthat these separations can be effected with far less expenditure oftime and labour than by the customary methods of fractionalcrystallisation or precipitation. The method adopted was theelectrolysis of somewhat concentrated, neutral solutions of salts ofthe rare earths, using a mercury cathode, kept clean by violentagitation with air, and a platinum anode. The most notable resultwas the complete separation of lanthanum from praseodymium bya very small number (6) of fractional electrolyses.About twiceas many operations suffice to separate lanthanum from admixturewith praseodymium, neodymium, and samarium, the lanthanumbeing in each case the last t o come out of solution. Yttrium canbe almost completely freed from erbium in five operations, but itis much less easy t o obtain erbium free from yttrium.34I n the application of Johnson’s or similar methods35 for theestimation of vanadium in steel, difficulty is often experienced inproducing a colourless or old-rose shade with ferrous sulphate in32 F. Mylius and A. Mazzucchelli, Zeitsch. anorg. Chem., 1914, 89, 1 ; -4.,ii. 491.33 Chem. News, 1915, 112, 88, 104, 125. 134, 144, 155.34 L. M. Dennis and B.J. Lemon, J . Amer. Chern. SOC., 1915, 37, 131 ;A . , ii, 99.C. M. Johnson, ‘‘ Analysis of Special Steels.ANALYTICAL CHEMISTRY. 179the solution containing an excess of permanganate after the pre-liminary oxidation of the vanadium. A method recently described,depending on oxidation of vanadium with nitric acid, avoids thisdifficulty. The blank correction is larger than is desirable, butappears to be independent of the weight of the sample, of thepresence of chromium, or-within limits-of the carbon content,and the method will estimate proportions of vanadium of the orderof 0-2 per cent. with an error not exceeding 0.007 per cent. onthe stee1.36The estimation of columbium in presence of tantalum is thesubject of a most important paper by Levy, who has investigateda number of methods, and has so far improved on a method devisedby Osborne in 1885 that this improved method is likely to begenerally adopted, except in cases where time would permit andcircumstances might dictate resort to Marignac’s original method,which, like all methods depending on fractional crystallisation, isvery tedious.Osborne’s method 37 depended on solution ofpotassium columbium oxyfluoride in hydrochloric acid, reductionwith amalgamated zinc and a piece of platinum foil, and titrationwith permanganate. It never came into general use, mainlyperhaps because Osborne’s statement that reduction proceeded asfar as a hypothetical oxide, Nb,O,,, rested apparently on a singleexperiment. Under Levy’s modified conditions, reduction onlygoes as far as Nb,,HI7, but under his conditions, which are nota t all difficult to attain, reduction does appear to reach and tostop a t this point with widely varying quantities of columbiumpresent.Several statements long current and having an importantbearing on the estimation of tantalum are shown to be erroneous.38O r p ? i i c A ttalysis.The usual colour tests for salicylic acid, although extremelydelicate, are none of them perfectly characteristic. By combiningKobert’s test with Itandelin’s, however, a series of colour changesis obtained which is quite distinctive of salicylic acid and salicyl-ates. The reagent is made, by mixing equal volumes of 40 percent. formaldehyde soluton and concentrated sulphuric acid andcooling the mixture.A portion of the substance to be tested ismoistened in a porcelain dish with this mixture, a little ammoniumvanadat(@ is added, and the whole stirred. If salicylic acid ispresent, a Prussian-blue colour appears immediately, rapidly36 G. T. Dougherty, J . Ind. Eng. Chem., 1915,7, 419; A . , ii, 490.37 T. B. Osborne, Amer. J . Sci., 1886, [iii], 30, 329; A . , 1886, 393.3t3 A. G. Levy, Analyst, 1915, 44l, 204; A . , ii,:491180 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.changing t o greenish-blue, and finally to green. A distinct reactionis given by 0.02 mg. of salicylic acid. A large number of sub-stances, mostly of phenolic constitution, have been tested. Manyyield colours, but none can be mistaken for a salicylate.39 A newtest has been described which serves t o detect 1 part of oxymorphinein 20,000 parts of solution and to distinguish this alkaloid frommorphine, codeine, thebaine, apomorphine, quinine, strychnine,brucine, atropine(, and caffeinel.40For the estimation of bromine and chlorine in organic com-pounds a method has been based on the fact that organic substancescontaining these elements give them up entirely in a volatile formwhen heated with a mixture of chromic acid and sulphuric acid.The final estimation is by titration according to Volhard’s method.The results are as accurate as those obtainable by Carius’s method,and can be obtained more quickly, with less consumption of theanalyst’s time, less expense, and no personal risk to the operator.41Some useful notes on the Kjeldahl and Dumas methods of estimat-ing nitrogen are included in a paper dealing with the analysis ofcoal.It is found that coal and probably some other substancesmust be digested for a considerable time (two hours) after theliquid is colourless if accurate resulix are to be obtained by Kjel-dahl’s process. The1 use of permanganate after the colourless stageis reached shortens the process. It is shown that Dumas’s methodmust always over-estimate nitrogen unless the copper oxide isheated f o r several hours in a vacuum and cooled in carbon dioxidebefore using it for a nitrogen determination. Otherwise nitrogenwill always be over-estimated and small proportions enormouslyover-e~timated.4~The estimation of toluene in commercial toluol and in commer-cial solvent naphtha having become of great importance, owingt o the demand f o r the hydrocarbon for the manufacture of trinitro-toluene, two empirical methods for the purpose have been workedout by Colman and Northall-Laurie respectively. Colman’s methodf o r commercial toluol consists in distilling 100 C.C.of the sampleunder prescribed conditions (such that fractionation is reducedt o a minimum) and measuring the fraction passing over below 1 0 5 Oand that remaining in the still when a temperature of 1 1 7 O isreached. By reference to a table the percentage of toluene maythen be read off directly if the mixture under examination con-39 P. A. W. Self, Pharm. J . , 1915, 94, 521; A ., ii, 382.40 L. Grimbert and A. Leclbre, J . Pharm. Chim., 1914, [vii], 10, 425; A.,41 P. W. Robertson, T., 1915,107, 902; A., n, 573.42 A. C. Fieldner and C. A. Taylor, J . Ind. Eng. Chem., 1915, 7, 106;ii, 76.A., ii, 177ANALYTICAL CHEMISTKY. 181sists solely of benzene, toluene, and xylene, and contains from 50 to75 per cent. of toluene. Samples with less than 50 per cent. oftoluene are mixed with a known proportion of pure toluene beforedistillation, whilst high-grade toluols must be diluted with knownamounts of benzene and xylene. Correction for paraffins is madeby distilling 100 C.C. through a 12-bulb “pear ” column and detm-mining the specific gravity of the fraction distilling between 1 0 7 Oand 1 1 5 O . For every 0.001 that the specific gravity is found below0.868, a reduction a t the rate of 9 per cent.is made on the amountof toluene found by the distillation test and reference to thetable construcbd f o r mixtures of pure benzene, toluene, and xylene.Colman fractionates commercial solvent naphtha, collects the frac-tion distilling below 138O, mixes this with pure toluene and purebenzene in the proportions 7 : 10 : 3, and analyses the mixture in themanner above described.43 Northall-Laurie distils 200 C.C. of com-mercial toluol, collects the first 50 c.c., rejects the next 100 c.c., andthen determines the boiling point of the first fraction and of theresidue in the still. On reference to a graph prepared as a resuItof experiments with known mixtures, the percentage of toluene isread 0ff.44Attention was directed in 1912 t o Simmonds’s modification ofDenighs’s method for the detection and estimation of methyl alcoholin the presence of ethyl alcohol.45 This method has recently beensubmitted to a critical examination, which showed that close at’ten-tion to detail was essential if accurate results were to be obtained.The particular details t o which attention must be given are nowknown, however, and if this is given there is no doubt the methodis the most accurate yet described, whilst i t is among the simplestand quickest.46 Thorpe’s original method, depending on a differentprinciple, although ussful in its day, was very much behind Sim-monds’s modification of Denighs’s method in sensitiveness, and wastending to fall into disuse.Depending as i t did on the measure-ment of the carbon dioxide yielded by the oxidation of methylalcohol, i t had the disadvantage that under Thorpe’s conditionsethyl alcohol itself yielded a notable amount of carbon dioxide,and, although this amount could be kept fairly constant, thecorrection was large, and with small quantities of methyl alcoholpresent might equal or exceed the amount of carbon dioxide derivedfrom methyl alcoho1.47 With comparatively little methyl alcoholpresent, therefore-and this is the most important case in practice43 H. G. Colman, J . Gas Lighting, 1916, 129, 196, 314; A., ii, 184, 185.44 D. Northall-Laurie, AnaEyst, 1915, 4.0, 384; A., ii, 703.45 Ann. Report, 1912, 212.47 T. E. Thorpe and J.Holmes, T., 1904, 85, 1.G. C . Jones, Analyst, 1915, 4.0, 218; A., ii, 493182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.-considerable doubt attached to the indications of the method.I n this respect the method has been greatly improved by Wilks,who has succeeded in finding conditions of oxidation which reducethe production of carbon dioxide from ethyl alcohol to less thanone-fifth of what i t might be under Thorpe’s conditions. Wilks’sconditions of oxidation not only reduce t3h0 correction t o beapplied, but keep that correction much more nearly constant thanwas the case with Thorpe’s method.48The, estimation of cellulose and the analysis of cellulose deriv-atives have been subjects of controversy49 so acute that a perusalof the literature by a chemist with no special knowledge of thesubject leaves the impression that no existing method can betrusted.I n these circumstances a paper by Briggs is of specialvalue. There being no question of the author’s knowledge of theliterature any more than of his practical experience, i t is matterf o r congratulation that he has not sought to display his erudition,but is content wit’h reference to a few papess and books of out-standing importance. Yet it would be difficult to formulate aquestion on thel estimation of cellulose or the analysis of cellulosederivatives that this paper of Briggs does not answer in termsreadily understandable by any chemist, no matter how scanty hisprevious knowledge of this particular subject.50Reference has been made in earlier Reports t o the cryoscopicmethod f o r the det’ection and approximate estimation of addedwater in milk.51 Most of the early work was carried out inAustralia and Holland, and workers in these countries have againbeen acti~e,5~ but i t is satisfactory to be able a t last t o record thatthe method has been thoroughly investigated in Great Britain.I n a report t o the Local Government Board, Monier-Williamsexpresses the opinion that the freezing point appears to be themost constant of any of the properties of milk.Owing, however,to experimental difficulties involved in obtaining trustworthyresults, he doubts whether the method is capable of general applica-tion for purposes of milk contro1.53 It has now been shown whythe freezing point o r osmotic pressure is the most constant factorof pure milk.Genuine but abnormal samples of milk with48 W. A. R. Wilks, Bull. Wellcome Trop. Res. Lab., 1914, 1, 1 ; L4., ii, 589.49 Ann. Report, 1912, 212.50 J. F. Briggs, Analyst, 1915, My 107; A., ii, 186.51 Ann. Report, 1911, 173; 1912, 214; 1913, 183; 1914, 178.52 J. B. Henderson and L. A. Meston, Proc. Roy. Soc., Queensland, 24,165; A . , ii, 28; G. A. Stutterheim, Pharm. Weekblad., 1914, 51, 1311; A.,ii, 29 ; J. J. van Eck, J. D. Filippo, F. H. van der Laan, A. Lam, A. van Raalte,and L. T. Reicher, Chem. Weekblad, 1015, 12, 108; A., ii, 112; N. Schoorl,ibid., 220; A., ii, 189.53 G. W. Monier-Williams, L.G.B. Food Reports, No. 22, 1914ANALYTICAL CHEMISTRY.183unusually low non-fatty solids, but normal freezing point, havebeen found to be cliaracterised by an abnormally high content ofsodium chloride, and there seems no doubt that the mammaryglands of the cow, when unable t o obtain the correct proportion ofmilk-sugar and other foodstuffs, adjust the osmotic pressure byadding an extra proportion of sodium chloride from the blood.54I n Germany it has been found necessary to devise a specialmethod for the detection of potato starch in bread. This dependson the fact that potato starch takes up certain coal-tar coloursmuch more rapidly than wheat o r rye starch. The best colour forthe purpose1 is thionin, but neutral-red o r methylene-blue serves.55Among new colour reactions for alkaloids, only one has beensufficiently tested to justify inclusion among these notes.Thedevelopment of a wine-red colour when heated with sulphuric acidcontaining 2 per cent. of formaldehyde serves to distinguish cocainefrom a t least nine other common alkaloids. Papaverine gives asomewhat similar colour, but this changes to yellow, reddish-brown,or orange, whilst the coloration due to cocaine disappears ‘on keep-ing, leaving a brownish-grey precipitate.56In view of the difficulty introduced into fat analysis by theintroduction of hydrogenated products, a newly described colourreaction of marine animal oils, which persists even in artificiallyhardened fats derived from them, assumes some importance. Thereaction depends on the fact that these oils and fats contain achromogenic substance which reacts with bromine to form a com-pound that imparts a bright green colour to a chloroform solutionof the fat or oil.The test appears to be specific of fats and oilsof marine animal origin, and is given by lard substitutes contain-ing as little as 5 per cent. of hydrogenated marine animal oil.57A test which will detect with certainty as little as 5 per cent. ofparaffin-wax in beeswax has been based on the fact that whengenuine beeswax is saponified with alcoholic potash under definiteconditions, the temperature to which the resulting solution can becooled without the appearance of a cloud is remarkably constant,whereas this temperature is notably raised by small additions ofparaffin-wax.58There is still no better agreement as to the best method ofestimating caoutchouc in raw rubber than there was when the54 J.B. Henderson and L. A. Meston, Chem. News, 1915, 111, 51.55 G. Schutz and L. Wein, Chem. Zeit., 1915, 39, 143; A., ii, 185.56 F. Pisani, Rend. SOC. Chim., Ital., 1914, 6, 132; A., ii, 191.57 E. Fortelli andE. Jaffe, Ann. Chim. Applicata, 1914, 2, 80; A., 1914, ii,822.58 M. S. Salamon and W. M. Seater, J. SOC., Chem. I d , 1915, 34, 461;A., ii, 587184 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.subject was last noticed in these Reports.59 The difference methodis still the method most used in routine technical analysis, and,within the year, Schidrowitz, in the course of a review of recentadvances in the analysis of rubber and rubber goods, has voicetlthe widely held view that for such work the difference method isthe most satisfactory yet available.For research purposes, how-ever, he admits that the direct methods must be kept in view.G0Of the older of these methods there is little new to record. Asthe result of an examination of several methods, Pontio 61 expressesthe opinion that the ultimate solution of the problem of estimatingcaoutchouc directly will be found in some development of Budde’stetrabromide method.62 I n its present state, however, that methodshows no advantage over the best of the simpler solution methods.Of these methods, that of Marquis and Heim62a is condemned byPontio61 on the ground that chloro.fo3.m and other solvelnts ofsimilarly low boiling point fail to dissolve rubber unless it be quitefreshly coagulated or precipitated. I f a solvent of higher boilingpoint, such as xylene, is employed, the solution filtered, concen-trated under diminished pressure, and poured into alcohol, resultsare obtained quite as good as those yielded by any direct methodyet described.Results obtained by such a method, if they con-firm results obtained by the method of difference, lend addedsignificance to the latter; if they differ, in the present state of ourknowledge the results of the difference method should be preferred.Of Alexander’s original nitrosite method 63 there is nothing newto record, but a modification of it, depending on the determina-tion of the carbon content of the nitrosite precipitate, referred totwo years ago, has been further investigated and shown t o be fairlytrustworthy.64 When the analysis of rubber was last consideredin these Reports, Vaubel’s method was one of a score the historyof which had got no farther than the author’s original paper.Ofthe score, it is the only one to have attracted criticism, and thisseems to have been met a t least as satisfactorily as has the criticismdirected against Budde’s original method or any of its develop-ments. Vaubel treats a solution of rubber in carbon tetrachloridewith potassium bromate, and titrates the excess of the latter inthe usual way. The reaction is stated to becloHl6 + 6Br = C10H14Br4 + 2HBr.6560 P. Schidrowitz, Analyst, 1914, 40, 223; A., ii, 496.61 Pontio, Arner.Chim. anal., 1914,19, 60; A . , 1914, ii, 301.62 Ann. Report, 1907, 214; 1911, 176 ; 1913,184.62a Ibid., 1913, 184. 63 Ibid., 1907, 214; 1911, 176.64 L. G. Wesson, J . Ind. Eng. Chem,, 1914, 6, 459 ; A., 1914, ii, 593.66 W. Vaubel, Gurnmi-Zeit., 1912, 26, 1879; A., 1913, ii, 630.Ann. Report, 1913, 184ANALYTICAL CHEMISTRY. 185It. has been alleged that the amount of hydrogen bromideeliminated largely depends on the purity of the reagents, tempera-ture, and concentration.66 This criticism seems to have been metsatisfactorily, but the author of the method admits that it requiresfurther development before it can be regarded as generallydppli~able.~’Agricultural Analysis.Several old methods for the estimation of ammonia in soils havebeen examined and found defective, and a new one believed t o besatisfactory has been described. Schloesing’s method fails, becausedilute hydrochloric acid does not extract the whole of the ammoniafrom soils.Of ammonia added as sulphate, not more than 70 percent. can be recovered. For the same reason Baumann’s method,which also depends on extraction with hydrochloric acid, must fail.E. J. Russell’s later method:* depending on distillation with veryweak alcoholic potassium hydroxide, also fails to return allammonia added to the soil as sulphate. His earlier method, andall methods depending on distillation with magnesia, lead to thedecomposition of organic nitrogenous compounds. The newmethod is a modification of Folin’s method for physiological liquids,the soil being mixed with sodium carbonate solution and theammonia carried over with standard acid by means of a current ofair.69 M.Steel’s modification 7O of Folin’s method, althoughapparently an improvement where urine is t o be analysed, is quiteunsuited to soils. His reagent-weak alkali hydroxide in satu-rated brine-has the merit of decomposing crystals of magnesiumammonium phosphate, which always separate on adding ammoniato urine, but the concentration of ammonia and water-soluble phos-phate in soil is so low that no such crystals are likely t o form inthe course of soil analysis; and, moreover, Steel’s reagent bringsabout very serious decomposition of the organic, nitrogenous con-stituents of soil, so that the ammonia in some cases is over-esti-mated 200 per cent.The view that soils when treated by the newmethod of Potter and Snyder do not form triple phosphate crystals,with corresponding underestimation of ammonia, is supported bythe fact that seven very different samples gave identical resultswhether treated by their method or by Folin’s modification, inwhich potassium oxalate is used to prevent the formation of mag-nesium ammonium phosphate.66 F. Iiirchof, Gu?nnzi-Zeit., 1913, 27, 9 ; A . , 1913, ii, 830.6 7 W. Vaubel and E. Wienertli, ibicl., 1913,28, 92; A . , 1914, ii, 301.68 J. Agric. Sci., 1910, 3, 233; A . , 1910, ii, 1104.69 R. S. Potter and R. S. Snyder, J . Ind. Enq. Chern., 1915, 7, 221; A., ii,277. ‘O J . BioZ. Ghem., 1910, 8, 365; A., 1911, ii, 68186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Substances exist in plant material which are soluble in 80 percent.alcohol, are not precipitated by basic lead acetate, are un-fermentable by ordinary yeasts, and reduce Fehling’s solution afterother sugars present have been fermented. From the fact that thereducing power of such substances, when calculated as a mixtureof arabinose and xylose, corresponds with a proportion of pentosenearly identical with that calculated from the Krober-Tollensphloroglucide distillation, it is assumed that free pent,oses areactually present, and that the furfuraldehyde formed on acid dis-tillation does not arise from gums, pentosans, o r other sugarspresent. From the results of nearly 400 fermentation experimentsmade with extracts of leaves, the amount of the residual reducingpower after fermentation with pure cultures of distiller’s yeasthas been found to be proportional t o the pentoses present as esti-mated by the Krijber method. When only small quantities ofother sugars are present, the direct distillation method, with sub-sequent weighing of the phloroglucide, is quite accurate, but inthe presence of large quantities of other sugars these should firstbe fermented away before applying Krober’s process.71The presence of water-soluble compounds of arsenic in arsenicalinsecticides is objectionable, as such compounds are injurious tofoliage, and the laws of the United States set a limit (0.75 percent. of A%03) to the amount that may be present in arsenate oflead sold f o r agricultural purposes. As in most cases where asoluble constituent has t o be estimated in admixture with a muchlarger quantity of insoluble material, and especially in theadministration of a penal statute, it was necessary to prescribe aparticular method of analysis. It has recently been shown thatthe prescribed method does not extract as much as 70 per cent. ofthe soluble compounds of arsenic, and a new method has beendescribed yielding results which on the average are 50 per cent.higher than those yielded by the official method. It is also shownthat the new method does actually extract soluble compounds, andthat the higher results are not due to hydrolysis or other chemicalaction. The new method consists in macerating the sample(5 grams) with water, transferring the mixture to a filter, andwashing it with nearly 1000 C.C. of hot water free from carbondioxide and ammonia. The soluble arsenate is then estimated inan aliquot portion of the filtrate in any convenient manner.72G. CECIL JONES.71 W. A. Davis and G. C. Sawyer, J . Agric. SOC., 1915, 6, 407; A., ii, 72.72 R. H. Robinson and H. V. Tartar, J. Ind. Eng. Chem., 1915, 7, 499A., ii, 581

ISSN:0365-6217    

DOI:10.1039/AR9151200171

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

PHYSIOTAOGICAL CHEMISTRY.I REMARKED in last year’s Report on the growing bulk and import-ance of the biochemical rese’arches published in the United States.It is not surprising that during the past year the relative promin-ence of American contributions has still further increased. Papersfrom the Journal of BioZogicaZ Chemistry will be found indeed t oyield a somewhat large proportion of the material dealt with in thisReport. Considering the special circumstances of the year, ourown output may, it is true, be looked upon as something more thanrespectable, but very few French, Italian, o r Rumian papers havebeen published. The record of German work in the abstracts isincomplete, and I have myself been able t o consult but few of thepapers in the original.Animal calorimetry in particular has been developed with greatenterprise across the Atlantic, and has reached a degree of accuracypreviously unequalled. I am tempted to begin this Report bydealing, in this connexion, with one o r two aspects of genmal meta-bolism which have received no recent comment.Geiiernl Jfeitabolism : t h e Basal illetaholism of Neiz aiid TVomeia :the “Surface Lnut’’: tJie Specific Dynamic A c t i o n of Food.F.G. Benedict has maintained the tradition of his associationwith Atwater, and has continued, with many co-workers, his admir-able calorimetric studies in the Nutrition Laboratory a t Boston,where the difficult technique of the subject has been greatlydeveloped under his guidance. G. Luskl has established a small,but accurate: calorimeter in the Cornell University Medical College,which has been successfully used in many experiments on infantsand on animals.Owing to Lusk’s inspiration and influence, itcalorimeter for clinical observations is working under admirableconditions a t the Russell Sage Institute of Pathology, which isassociated with wards of the Bellevue Hospital, New York.2 I nthis country comparatively little enterprise has been shown on these1 Arch. Int. Med., 1915, 15, 793.1 s72 Ibid., 805188 ANNUAL ‘REPORTS ON THE PROGRESS OF CHEMJSTRY.lines, but we are fortunate in knowing that Macdonald has anefficient instrument, built on the Atwater-Benedict principle, inuse a t Liverpool.3Benedict and other American workers have given much attentionto what is now known as “ basal metabolism,” and have determinedit on a large number of men and women.This basal metabolismrepresents the minimal energy exchanges of the body, and ismeasured when the individual is in a recumbent position andperfectly quiescent. It is determined, moreover, when no digestionor absorption of food is in progress, in what Benedict calls the“post absorptive” period, some fifteen to eighteen hours after ameal. F o r men weighing near the average of 70 kilos. this basalmetabolism is closely equal to one large calorie per kilo. per hour;but any considerable departure from the mean weight involves anappreciable change in the value when it is expressed, as above, interms of the unit of body-weight.It is a matter of some importance t o decide how nearly we can,by any method of calculation, obtain a definite numerical valuef o r the “normal” metabolism of a given species of animal.Whendepartures from the normal are suspected, observations meant t odecide on their magnitude have often to be made on compara-tively few individuals; sometimes on one alone. Individuals.however, quite apart from the possession of that particular anomalyor special character which is under study, may differ greatly fromthe mean in respect of such fundamentals as size and body-weight.How can the effects of such non-significant variations be best elimin-ated; or, what is the same question in different terms, from whatnormal baseline can we1 measure the effect of the significant varia-tions? This is not an academic question; i t is of practical import-ance to physiologists and pathologists, and, no less, to agriculturistsconcerned with ths raising of stock.I n the endeavour to eliminate to some degree the effect ofindividual variation in size, it has long been customary to expressall metabolic data in terms of the unit of body-weight; but it hasalso long been recognised that values when expressed per kilo.ofbody-weight do not necessarily become comparable values. Normalmetabolism is not simply proportional to body-weight. I n the caseof human beings Benedict’s newer data make this abundantly clear.Another method commonly supposed to be more justifiable ist o express all values on the basis of metabolism per square metreof body-surface. The wide use of this method is largely duet o the influence of Rubner. Underlying the teaching of thisphysiologist is the idea that the animal body, being subject toSee J.Physiol., 1914, 48; PTOC. Physiol. Soc., xxxiiiPHYSIOLOGICAL CHEMISTRY. 189Newton’s law of cooling, so metabolises that the loss of heat due tocooling may be exactly replaced. On this view, indeed, it is theloss of heat, itself a function of the us face, which definitely deter-mines, in a causative sense, the rate of metabolism; the velocity ofchemical change in the tissues is determined directly by the extentof the body-surface. This conception Rubner has elevated to theposition of a “physiological law,” and upon it as dogma he hasbuilt up an elaborate body of doctrine concerning living matterand its energy exchanges.4 Recent research seems to show thatthere is nothing absolute or exclusive about the relation betweensurface and metabolism.Cosrelation between the two there is, andmust be. When thers is a marked difference of size between twowarm-blooded animals, as may be the case in individuals of distinctspecies, it is clear that the smaller, with its relatively much greatersurface, and consequent relative greater loss of heat, will demandmore rapid oxidations f o r the maintenance of its body-temperature.The rate of metabolism per unit of weight in the mouse is, need-less to say, enormously greater than that in the elephant. Whatmay be questioned is the dogma that loss of heat by the surfaceis the sole contributing f actor-is the essential cause-of meta-bolism.I f it were, if the rate of change in the bodies of allnormal individuals were determined by the extent of body-surfacealone, then, when placed in similar circumstances, all such indi-viduals would display equal metabolism per square metre ofsurface. We should then have a simple and definite means forreducing all OUT observations made on different individuals toa common measure; but there are no relations so definite as these.The available evidence for the existence of the surface law,read strictly, has, in respect of the animal kingdom as a whole,been recently summarised, and shown to be unsatisfactory by A.Krogh.5 Benedict’s6 recent studies made on men and women seemto be conclusive against it.A glance a t the curves given by him,in which the heat production of normal individuals is plottedagainst their calculated body-surfaces, shows a t once how irregularis the relation. The extreme variations found we’re, in the case ofmen, from 693 to 958 calories per square metre of surface pertwenty-four hours, and, in the case of women, from 633 to 905calories. The individuals studied by Benedict (eighty-nine men“ Die Gesetze des Energieverbrauchs,” Franz Deutsche, Leipsic andVienna; “Kraft und Stoff im Hanshatte der Natur,” Leipsic, Akad. Ver-lagsgesellschaft.“ The Respiratory Exchange of Men and Animals,” Monographs ofBio-chemistry, Longmans, 19 16.J. Biol. Chern., 1915, 20, 263; A ., i, 475; see also ibid., 231, 243, 253;A, i, 474, 475190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and sixty-eight women) were all such as would be called " normal,"although they varied somewhat widely in size, age, and occupation.Even within a small, carefully selected group of persons variationin the relation between surfam and heat production may be con-siderable, as is shown by the observations of W. JV. Palmer, J. H.Means, and J . L. Gamble.7 Benedict in a summary remarks thatwhilst certain disturbances in the supposed relationship betweenthe two variables may correctly be ascribed t o errors in the formulzused for calculating body-surface, nevertheless the vast bulk of theevidence shows that the variations between metabolism and surfaceare far outside any possible errors in formulz.The essential factorswhich determine the1 grade of metabolism are the amount of activeprotoplasmic material in the body and the degree of its activitya t any moment. The degree of activity depends on more than onecircumstance. This, after all, is what, in the absence of doctrinaireviews, we should expectl. Surface has an important influence onmetabolism, but other influences may be also of sufficient import-ancel t o obscure any simple relation between them.I may now quote some observations made on individuals withinmore carefully selected groups. Palmer, Means, and Gamble 8 madetheir determinations on young medical men closely agreeing inage. They found a variation of 1 2 per cent.in tthe heat evolvedper square metre of surface. J. R. Murlin and B. R. Hoobler9have stludied the energy metabolism of ten hospital childrenbetween the ages of two months and one year. They have alsocalculated, from studies published by others, the average heatevolved per unit of surface in the case of sixty-one Americaninfants. They find the average deviation from the mean value of39.3 calories per square metre and hour is 11 per cent.; when theresults are calculated petr kilo. of body-weight the deviation is12.1 per cent. F. C. Gephart and E. F. DuboislO have determinedthe basal metabolism of normal men, and in discussing their results,together with others available in the literature of the subject, theyconcluded that among groups of men of varying weight metabolismis more nearly proportional to surface than to weight.They never-theless admit that the departure of normal men from the average,as based on surface, is such that a given condition cannot be saidto be definitely abnormal unless the Variation from the mean is ofthe order of 15 per cent.If one surveys all that has been published on the subject theconclusion is reached that. to calculate metabolism per unit ofJ . Biol. C'hem., 1014,19, 239; A, i, 1914, 1184. 8 LOG. cit.9 Amer. J . Diseases of Children, 1915, 9, 81.10 Arch. Int. Med., 1915, 15, 835PHYSIOLOGICAL CHEMISTRY. 191surface is somewhat more accurate than to calculate it per unit, ofweight, especially when the individuals t o be compared vary con-siderably in size.The existence of any ‘( law,” involving a constancyof metabolism per unit of surface is, however, imaginary.The physiologist is, indeed, always face to face with difficultiesdue t o individual variations in men and animals. I n metabolismexperiments the supposed normal ‘(control ” is often the weakestspot. Accuracy in technique does not suffice; the living organismis itself the uncertain factor. The re’medy can, however, sometimesbe found in patience. I f the existence of a metabolic variation ofsmall or moderate degree is to be established, a proportionatelylarge number of individuals must be studied. By comparing, forexample, a large number of individuals suffering from severediabetes with m equal number of normal individuals of the sameweight and height, Benedict and Joslin l1 have proved conclusiveIythat there is in that disease an increment in metabolism amountingto 15 or 20 per cent.I n the following table I have collected figures from recent papersshowing the basal metabolism (defined as above) of men, women,and infants :Heat per l‘wenty-four Hours in Calories.Per kilo.ofCla.ss.body weightAthletes ........................... 26.0Untrained individuals com-parable with the above.. .... 24.4Women ........................... 26.0Men of approximately equalheight and weight ............ 26.5Normal men of variousheights ........................... 25.964.8 Average of 61 infants ............Per squaremetreof surface.86-380.777.081.983.294.3Observers.H. M.Smith.F. G. Benedict andF. G. Benedict andH. M. SmithF. G. Benedict andL. E. Emmes.F. G. Benedict andL. E. Emmes.F. C. Gephart andE. F. Dubois.J. R. Murlin a.ndB. R. Hoobler.It will have been understood that all the figures previously givenrelate to metabolism during rest and abstinence. It is a matterof great interest to decide how far this basal metabolism is affectedby the mere taking of food. Suppose an individual whom basalmetlabo~lism has been dekrmined remain completely a t rest, sothat the exlarnal calls on the body remain as before; will theabsorption of food, by itself, affect the rate’ of metabolism? This,l1 Carnegie Institution, Publication No. 176, 1912192 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.again, is by no means an academia qumtion; for if a considerabledegradation of energy occurs during, and as a result of, the assimi-lation processes, such energy will not be available in support ofthe specific activities of the tissues. We shall have to deduct it, o rsome fraction of it, when appraising the real availability of thefood eaten.Rubnelr during a number of years carried out experimenh t otest this question.He decided that whereas fats and carbohydratescause comparatively little rise in metabolism during their diges-tion, absorption, and assimilation, the case of protein is verydifferent. When protein is eaten, some 30 per cent. of its availableenergy can, if the experimental conditions are rightly adjusted,be shown to appear as hefat during the assimilation period.ThisRubner called the specific dynamic action of protein. Its quanti-tative estimation offers, ho8wever, considerable experimental diffi-culties, and it's precise meaning is yet under discussion. Lusk 12 andhis co-workers have contributed some interesting papers to thesubject during the past year.The theory of Zuntz that the postrprandial rise in metabolism isdue simply t o increased activity of the digestive glands and theintestinal musculature is now known to be insufficient, and notsupported by the weight of the evidence. Rubner has attributedthe rise to the liberation of energy in those intermediary che,micalprocesses which precede the utilisation of protein as a source ofenergy for the true basal cell metabolism. Roughly speaking, itrepresents, on Rubner's view, the energy lost during the convessionof part of the protein into carbohydrate and fat.Intermediaryproducts are simply oxidised with the production of extra heatwhich is in no way involved in the true life processes of thecells. It is, indeed, essential to Rubner's conception of metabolismthat we should look on the significant energy exchanges ofliving matter as fixed and definite in amount, save as affected byvarying ratles of heat loss. An increase in the supply of materialcould not affect this essential metabolism. G. Lusk, however, takesanother view, returning in a sense to the original teaching of Voit.His experiments have led him to believe that products derivedfrom protein directly stimulate the tissue cells to increased activity.I n his earlier papers13 he ascribed this action to unaltered amino-acids, but the work published during the past year has led him tothe conclusion that it is certain acid intermediary metabolitesderived from the amino-acids which actually stimulate the tissues ;l2 J.Bid. Chem., 1915, 20, vii, A , i, 614; ibid., 555; A , i, 614.l 3 Ibid., 1912-13, 13, 158; A . , 1913, i, 123PHYSIOLOGICAL CHEMISTRY. 193glycollie and lactic acids, for iiistanre, in tIie case of glycine anda 1 a n in e respective 1 y .Certain experimental results obtained by Lusk may be quoted.Fifty grams of dextrose given to a fasting dog increased the basalmetabolism 30 per cent., and 70 grams 35 per cent.There waslittle differeace due t o the increase of sugar. “Twenty grams ofglycocoll increased it 35 per cent., and the same amount of alanine32 per cent. Combined, 50 grams of glucose and 20 grams ofglycocoll are the glucose equivalent of 66 grams, and yet when theywere given together the metabolism increased 56 per cent. Glucoseand alanine in similar quantities are a glucose equivalent of70 grams, and caused an increase o l 53 per cent. in the heatproduction. i t is obvious t h a t an increase in the quantity ofglucose, when this is given in large amounts, scarcely affects meta-bolism, whereas when the chemical stimulus from the’ metabolismproducts of tlie amino-acids acts on the cells, in conjunction wit11R plentiful supply of glucose, the resultant effect is nearly equalto the sun1 of the two individual influences.This points to adistinct difference between the cause of the specific dynamic actionof glucose and t h a t of alanine, which latter is convertible intolactic acid and eventually in&o glucose.” 14Metabolism is increased by the injection of sugar o r fat, b u t this,according to Lusk, is not because they, o r their products, stimulatein any special sense. The increase is simply due to plethora, totlie fact t h a t a high concentration of mat’erial surrounds the cells.When 10 grams of laevulose are given to a phloridzinised dog thereis no increase of metabolism as measured by heat evolution; thewhole of tlie lzvulose being excreted as dextrose: b u t when12.5 grams of glycine are given, an amount of the amino-acidwhi’cli aleo yields 10 grams of dextrose t o thO urine, there is alarge increase of metabolism due to the stimulativel action ofproduct’s intermediate between the amino-acid and the dextrose.There is a difficulty always present in animal experimentc; devisedto demonstrate the influence of food ingestion or other similarfactors on the basal metabolism.It is almost impossible to securecontinuous quiescence of the animals. Movements which followon the process of feeding may be themselves responsible for a largeincrease in the heat evolved. Needless to say, in the techniqueused by Lusk this source of error was foreseen and eliminated sofar as possible. I n the endeavour t o eliminate it altogether,C.G. L. Wolf and T. S. Hele15 have worked with decerebratels J . Biol. Chem., 1915, 20, vii-xvii; A . , i, 614.l5 J . Physiol., 1914, 48, 428; A . , 1914, i , 1186.REP.-VOL. XII. 194 AXNLJAL BELWltTS ON THE PROGRESS OF CHEMISTRY.animals. They show that t’he injection of glycine into the circu-lation of decerebrate dogs causes a sharp .rise in metabolism, con-firming, therefore, the view of Lusk. The actual quantitative valueof experiments of this kind is somewhat lessened, however, by thefact that the basal metabolism continuously falls during the experi-ment owing to the1 treatment received by the animal.The Chemistry of Proteins: Some Aspects of ProteinMe ta b olism.A valuable addition to the technique of protein chemistry isfound in F.W. Foseman’s16 method of separating the dibasic acidsfrom the mixture of amino-acids which is obtained on hydrolysingproteins. The calcium salts of glutamic and aspartic acids can beprecipitated quantitatively from their aqueous solutions by meansof alcohol. When so precipitated from an amino-acid mixture, andliberated from their lime salt5, these two acids can be purified bytaking advantage of their insolubility in cold glacial acetic acid.Foreman 17 shows that glutamic acid is converted into l-pyrrolidone-carboxylic acid when its aqueous solutions are boiled, and thechange occurs to a small eatent even a t the temperature of evapora-tion on the water-bath. To make the above process fully quanti-tative, therefore, it is probably necessary to carry out all opera-tions a t a temperature below 4 5 O .Any addition to analyticalmethods which are really quantitative cannot but be welcomed byall concerned wit’h the study of proteins, whether from the physio-logical or chemical point of view. P. HartJey,l8 in an elaborateand careful study of the proteins of ox- and horseserum, has shownhow very successful the metlhod of Van Slyke can be in givinginformation as t o the amounts of various amino-acids containedi,n any protein, and in enabling us to compare one protein withanother. A doubt has often been felt and expressed with regardto the existence of real chemical distinctions between the proteinswhich have been fractionated from blood serum. The real differ-ence might well be only physico-chemical, one type of protein beingeasily convertible into another.Various observers, i t is true#, haveobtained more o r less conclusive evidence for chemical differences,but the exhaustive study made by Hartley leaves no doubt aboutthe matter, a t least as regards a distinction between albumins andglobulins. The former contain a notably greater proportion ofdiamino-acids, and especially, as Hartley demonstrates, of lysine.They contain also peirhaps twice the quantity of cystine found in16 Biochem. J . , 1914, 8, 463; A . , 1914, i, 826.l7 Ibid., 481; A . , 1914, ii, 1205.l8 Ibid., 641; A . , 1914, i, 1206PHYSIOLOGICAL CHEMISTRY. 195the globnlins. 011 the other hand, the different tJypes of glahuli~iagree in respect of their amino-acid coiiteiit, and the fact thatn thepseudo-globulins ” and * * euglobuliris ” thus agree lends supportto the view of Harriette Chick19 that tlie euglobuliii of serum isrnerely a mechanical complex of pseudoglobulin and lipoid.Theproof that the albumins and globulins of blood are chemicallydistinct lends great interest t o thel problem of their physiologicaldifferentiation. Have they different origin and different functions ?Hartley‘s figures, i t may be noted, do not show such differencesbetween the corresponding protein fract’ions from ox blood andhorse blood respectively as to supply a basis for those specificcharacters which other evidence has led us t o recognise; but themethod used offers, of course, no evidence concerning the groupingof the constituent amino-acids within the molecule of the protein.In this there are infinitel possibilities for variation.So many workers are now employing D.D. Van Slyke’s methotlthat i t may be well to point out that he has recently introducedsome improvements into it, and has recommended a iniiior niodi-fication in the apparatus for his micro-method. He has alsopublished a correction in the formula for calculating the amount ofhistidine.20I gave a good deal of space in the Report f o r 1913 to H. D.Dakin and H. W. Dudley’s21 views concerning the racemisation ofproteins by treatment with alkali, a phenomenon which theyexplain as an effect of keto-enol tautomerism a t the! peptide link-ing.22 The subject seems to me very important, and as a papercriticising Dakin and Dudley’s view has recently appeared it willbe well to refer to it.P. A. Kober23 has made a spectrophobometricstudy of amino-acids and polypeptides, and finds that the absorp-tion of aliphatic acids is only of a general s o r t in the extremeviolet. On the other hand, the aromatic acids (tyrosine and phe’nyl-alanine) show marked bands, which may be useful f o r demonstrabing their presence in unknown polypeptides. The chief point inthe paper, however, is the demonstration that the spectra of di- andtri-peptides show no special absorption bands in acid or alkalinesohtion, but only the absorption due to the constituent amino-acids. The fact that this is true of alkaline solutions, in whichracemisation is said to occur, yields in Kober’s opinion -evidenceagainst the occurrence of the tautomeric phenomena which Dakinand Dudley’s hypothesis demands.Previous work, that in con-lD Biochem. J., 1914, 8, 404; A., 1014, i, 1145.2o J . Biol. Chem., 1915, 22, 281 ; A . , ii, 851 ; i b i d . , 23, 407 ; R . , 1916, ii, 61.21 Ann. Report, 1913, 192.22 J . Biol. Chenz., 1915, 23, 411.28 Ibid., 22, 433 ; A . , ii, 716.H 196 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.nesioii with the acetoacetic series, for example, would lead to tlieexpectation of specific absorption in the case of the peptides ifdyiizmic tautomerism exists in coiinexion with linkings. Koberfurther ponts out, that since, according t o Fischer and Abderlialden,trypsin digests many, and erepsin all raceniic polypeptides, it isremarkable, that the “racemised” protein is found t o bel whollyindigestible.The fact seems t o suggest that a more profound changein the molecule has occurred in the process of “racemisation.”Of the remaining criticisms brought forward by Kober I mustgive space t o one only. It will be remembered that on hydrolysisof racemised protein certain of the amino-acids liberated are in theoptically inactive form, but others are still active. Dakin suggeststhat tlie latter occupy terminal positions in the molecule, wliexetheir amino- o r carboxy-groups share in no peptide linking. Koberpoints out that recent evidence has shown that native proteins havefew, if any, unlinked groups of this kind.D. D. Van Slyke andF. J. Bircliardg4 found, by trhe use of Van Slyke”s reagelnt, thatgelatin and casein contain only one type of free aniino-groups,namely, that corresponding with the second amino-group of thediamino-acid lysine. This point has been confirmed by Hartley,’5who finds that the1 fre’e amino-nitrogen of the blood albumins andglobulins is, in each casel, equal t o one-half of the lysine nitrogen.Exactly the same1 relation has beeln shown by T. B. Osborne, D. D.Van Slyke, C. S. Leavenworth, and M. Vinograd26 t o hold in thecase of gliadin, lactalbumin, and the protein of the rice kernel.I n eight distinct protleins, thereforel, of varying type and origin thesecond amino-group of lysine appears t o be tlie only one! whichtakes no share in the peptidel linkings.The work of the variousauthors quoted in this connexion well illustrates the progress whichis being slowly made towards an understanding of the internalstructure of the, protein molecule.T. B. Osborne and L. B. Mendel27 have continued their interest-ing studies dealing with the varying capacity of individual proteinst o maintain the animal or t o promote growth. They bring furtherevidence to show how t.hel relative failure in nutrition of certainprotleins can be compensated and removed by the artificial additionof those amino-acids which, in such protleins, are present inrelatively too small an amount.This effect is seen, for example, when cystine is added t o casein,and lysine to edesbin.24 J .Biol. Chem., 1913-14, 16, 530; A . , 1914, i, 212.25 Biochem. J . , 1915, 9, 269; A., i, 735.26 J . Biol. Chem., 1915,22, 259; A., i, 1018.27 Ibid., 20, 351; A . , i, 476PHYSIOLOGICAL CHEMISTRY. 197A point of some importance is to be noted in the exceptionalefficiency of lactalbumin as a supporter of growth. I n this proteinthe balance of amino-acids seems to be particularly favourable.When, in Osborne and Mendel's experiments, the protein formed9 per cent. of the food, individual rats gained some 90 grams onlactalbumin and in the same period gained only 59 grams oncasein.It is clear t h a t the quantitative balance of amino-acids presentin the protein eaten will affect, not) only the amount necessary tomeet the minimal requirements of the animal under various condi-tions, but also the optimum ratio of the protein in the diet.E. V.McCollum and M. Davis26 have determined the effect of varyingratios of protein. They find that the weights of rats can be main-tained on diets in which the proportion of protein, when it is milkprotein, is so low as 3 per cent. As i t is increased from 3 per cent.t o 8 per cent. the velocity of growth of the animals proportionatelyincreases. Proteins from wheat elnibryo are as efficient as milkprotein, but those' of the whole wheat grain are inferior. A dietarycontaining 6 per cent. of the latter has less power of supportinggrowth than one with 4 per cent. of the former.Some experiments have been described which illustrate how rapidare the processes of probein metabolism.F. A. Csonka 29 has shownthat tlie simpler amino-acids require for their total metabolismunder optimal conditions a period of about nine hours' duration.Dextrose when fesd, as such, t o a phloridzinised dog was found torequire nearly the same length of time for its excretion as does thesugar derived from equivalent quantities of glycine and alanine.From this observation the coiiclusioii is drawn t h a t the entireseries of metabolic changes leading t o the synthesis of dextrosefrom amino-pcids, together with the excretion of the sugar formetloccupies a period of time but slightly in excess of that necessaryfor the simple absorption and assimilation of tlie correspondingamountl of dextrose directly ingested.N. W. Janney,30 quite indepen-dently, has shown that prot'eins themselves, when given to diabeticdogs, are1 so metabolised t h a t all the extra dextrose and nitrogenare eliminated by the ninth hour after ingestion. I n a separatepaper Jannsy combines his own results with those of Csonka, andconcludes t h a t the processes involved in the pliysiological treatmentof proteins, including tlie hydrolysis into amino-acids, the absorp-tion and deamination of these, the synthesis of dextrose and ureaanti their elimination, all occur in a period that is but little longerthan that occupied by tlie simple process OF absorption anti elimina-2R J . Biol. C ' l i c ) ~ , 1!)15, 20, 415; -,I., i, 476.29 Ibid., 639; A . , i, 616. 30 Ibid., 22, 191 ; d., i, 1026198 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion of dextrose.That the velocity of chemical change in the bodycan be so great makes clear how difficult is a.ny endeavour t o studythe individual st'eps in intermediary metabolism.The Metaholism of Carbohydrates aizd Fats.An important paper from Starling's laboratory by V. H. Moos-house, S. W. Patterson, and M. Stephenson 31 deals with metabolismin depancreatised dogs. The research described was clearly verycarefully planned and organised, whilst the technique used seemsabove criticism. The gaseous metabolism was determined inthe small regpiratory calorimeter devised by Benedict, andspecia1 attention was given to the respiratory quotient. Thedextrose :nitrogen (DIN) ratio was determined, as we11 as theexcretion of the acetone substances.Eight dogs were studied. Itis clear that in experimental studies of the kind described in thispaper the difficulties due to individual differences in basal meta-bolism largely disappear. Each animal wa.s studied first whennormal and afterwards in the depancreatised condition. It isinteresting t o find that the rise in total metabolism due to thecondition averaged 15-20 per cent., the same figure as that foundby Benedict and Joslin f o r human diabetes.I n its bearing on the still moot question as to whether in theabsence of the pancreatic influence there is over-production ofsugar, o r whether the error is rather in the failure t o utilise it,the low respiratory quotient observed in pancreatic diabetes isclearly important.Respiratory quotients may, i t is true, beaffected by several factods, and conclusions must be drawn fromthem with due caution ; but the authors, having duly consideredthe possibilities, conclude, no doubt justly, that their experimentson respiration offer very little evidence of the utilisation of sugarin the fully depancreatised dog. The diminished rise, o r theabsence of any rise, in the value of the quotient after the directadministration of dextrose is certainly strong evidence againstutilisation. From the analyses of the urine and their respiratorydata Moorhouse, Patterson, and Stephenson calculated the percent-age share in the total metabolism taken by protein fat and carbo-hydrate respect'ively.When fed on meat the normal dog callson protein for about 15 per cent. of its metabolism; the diabeticanimal uses i t t o the extent of some 25 per cent. Fats appear, fromthe results given, t o be unexpectedly well dealt with in theanimal witliout a pancreas, and may support by far the greaterpropc?rtion of tlie total metabolism. Calculations on the lines just31 Biochewt. J . , 1915, 9, 171 ; A . , i , 476PHYSIOLOGICAL CHEMISTRY. 199indicated strengthen the evidence derived from the respiratoryquotient in showing how small is the utilisation of sugar.I n the Report f o r 191332 I felt justified in saying that currentwork suggeeted that the pancreas is concerned in stabilising thecarbohydrate sources of the body rather than in promcting theactual utilisation of sugar. The work just quoted seems to pointonce more in the opposite direction.This problem-certainly one ofthe most important in pathological chemistry-is extraordinarilyelusive.The somewhat extraordinary observation has been made that theinjection of invertase can diminish the excretion of sugar in pan-creatic diabetes, and even stop i t altogether when the dose is suffi-ciently large.33For an understanding of the chemical changes involved in theutilisation of sugar a knowledge of what is the precursor of lacticacid in muscle is of prime importance. G. Embden34 and his schoolbelieve that this precursor is hexose-phosphoric acid. If this bea fact, it is one of great interest, especially in connexion with thesynthetic production of the aame substance by the yeast cell.Thecompound has, however, not yet been isolated from the muscle,although Embden and Laquer have fractionated muscle juice andobtained products which contain organically combined phosphorusand a reducing, optically active, component. The chief fact relied onin proof of the nature of the “lactacidogen” is the gradual libera-tion in expressed muscle juice of lactic acid and free phosphoric acidin equimolecular propcrtions. When hexose-phosphoric acid is addedto the juice the production of lactic acid and phosphoric acid isincreased. These researches are of interest, but the results are asyet by no means conclusive.I may call attention here t o the observations of H.7 N . Dudleyconcerning the variation of glyoxalase in blood. This catalyst,discovered by Dakin, is concerned, i t will be remembered, in theconversion of methylglyoxal into lactic acid. Dudley found thatglyoxalase activity, whilst very constant in the blood of a givenspecies, shows definite variations when different species of animalare compared. Those animals which display high glyoxalase valuesare those with high tolerance f o r sugar; those with lower valueshave less well-developed power of assimilating sugar. Such observations tend to confirm the view that methylglyoxal is a metaboliteintervening be’tween sugar and lactic acid.I n the intermediary metabolism of fatty acids two lines of32 Ann. Report, 1913, 202.33 I?. La Franca, Biochern.Zeitsch., 1014, 67, 332; 21.. i , 24.34 See series of papers in Zcitsch. physiol. C‘hcnr., 191.1. 93, 1-144 ; A . , i ,344-346200 ANNUAL REPORI'S ON 'I'HE PROGRESS OF CHEMISTRY.chemical change have been demonstrated. The first is the familiar&oxidation process brought t o light by the work of Knoop; thesecond is a preliminary desaturation occurring in the liver, towhich Leathes called the attention of physiologists. The latter hasreceived less attention from experimentalists than the former, butV. H. Mottram has published several papers dealing with thesubject. I n coiljunction with R. C00pe35 he has now broughtforward evidence to show, first of all, that the transport of thefats from the depots t o the liver is a physiological process; i t isseen, f o r instance, as a prominent phenomenon in late pregnancyand early lactation.A t these times the livers of rabbits show adefinite fatty infiltration with an increase of total fatty acidamounting to 50 per cent. above the normal mean. I n a laterpaper containing abundant experimental data Mottram and Coope 36show that the iodine value of the fats found in the liver lies charac-teristically between the values for the depot fats and tissue fatsrespectively. This, of course, is what would be eapected if thedepot fat is desaturated in the liver before proceeding t o the activetissues f o r utilisation. At the time of parturition the iodine valuesof the liver fatty acids lie nearer t o those of the depot fatty acidsthan in normal control animals, a fact yielding further evidenceof an infiltration of the liver with fats from the depots.Exogenous Growth Hormones.I dealt with vitamines a t some length in my last Report, butmainly on critical lines.The subject of accessory food factors is agrowing one and requires some further reference here.I n April, 1915, E. V. McCollum and M. Davis37 published apaper describing experiments in which growth approximating t othe normal rate, together with reproduction and rearing of a por-tion of the young, was obtained on synthetic dietaries composed ofcomparatively pure materials. This paper has, not unnaturally,been thought to yield evidence against the existence of unknownaccessory food substances, or a t least to disprove the assumptionthat' they are essential to growth.To anyone well acquainted with the circumstances i t was quitet o be expected that the extraordinarily small amounts of thesesubstances which are sufficient t o determine the difference betweenan efficient and a non-efficient dietary, would lead t o the publica-tion of such results as those of McCollum and Davis.It should heunderstood, however, that these authors, in the papers just referred35 J . PhysioZ., 1914, 49, 2 3 ; 9., i , 69.36 IFid., 49, 157; A . , i, 477.37 J . B i d . Chem., 1915, 20, 641 ; A . , i, 617I’HTSLOLOGICAL CHEXISTRT. 202to, expressly disclaimed for themselves any desire t o put forwardtheir experiments in disproof of the necesiity of vitamines orhormones in the diet.Their synthetic dietaries contained lactose,and although Merck’s and Kaklbaum’s preparations of the sugarwere employed i t was recognised that such material was possibly notpure enough f o r experiments of this type.The later experience of the same authors is most instructive. I nextending their experiments, and especially while studying thedietary deficiencies of rice,38 they found t h a t impurity in thelactose was undoubtedly the cause of the growth obtained in theirearlier experiments. Using properly purified casein, butter fat, andsalts, with dextrine replacing the lactose, they were unable toobtain appreciable growth even during the first month of feeding.That the effect of lactose is not due t o its special qualities as acarbohydrate is shown by the varying effect of different samplesand also by the fact that when other carbohydrates are employed,as in my own experiment^,^^ growth is quite normal if the hormonefactor be duly supplied.t h a t there arenecessary f o r normal nutrition during growth two classes ofunknown accessory substances, one soluble in fats and accoinpanyingthem in tlie process of isolation of fats from certain foodstuffs, andthe other soluble in water, but apparently not in fats.” They them-selves,40 and also Osborne and Mendel,41 have published observa-tions showing t h a t certain fats, in particular butter and cod liveroil, promote growth, whilst others, such as tallow and lard, haveno such power.Some vegetable fats belong to the former category,some t o the latter.This variation is due, not t o the essentialnature of the fats themselves, but because of a varying contentof the hormone factor.McCollum and Davis now claim t h a t when the remaining con-stituents of a synthetic dietary are sufficiently well purified theaddition of butter f a t alone fails to promote growth. The secondfactor (soluble in water and alcohol) is also necessary. This explainswhy C. Funk and A. B. Macallurn42 have been unable t o obtaingrowth when butter alone is added.No one who properly appraises the evidence now available willdoubt for a moment t h a t growth in the animal calls f o r constituentsin tlie diet which have nothing t o do with the energy supply, and,in all probability, nothing t o do with the supply of actual structuralThese authors have now coiiie t o the coiiclusion38 J .BioZ. Chew., 1915, 23, 181, 231.an J. PhysioZ., 1912, 44, 425; A . , 1912, ii, 779.40 J . Biol. Chem., 1915, 21, 179; A . , i, 61741 I b i d . , 1914, 17, 401; A . , 1914, i, 619.42 Zeatsch. phystol. Chem. 1914, 92, 13; rl., 1914, i , 1017.H’202 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.material. It should be fully recognised t h a t we have absolutely noknowledge of the chemical nature of such substances. Some nega-tive evidence in this connexion is n o t without interest. Butteruiidcubtedly contains a specific growth hormone. Now Osborne andRIeiidel claim that centrifuged butter f a t contains neither nitrogennor phosphorus,43 although this was doubted by MaCollum andDavis.Punk and Macallum found 0.0008 per cent. of nitrogen.44Osborne and Mendel have proved t h a t when butter f a t is fraction-ally crystallised from alcohol all the specific growth factor remainsin the less crystallisable fraction of low melting point, t h a t is, inthe butter (‘oil.” 45 Osborne and A. J. Wakeman 46 have estimated thephosphorus in this fraction a t 0.0006 per cent. These figures are sosmall t h a t it seems unlikely t h a t the growth substances containeither nitrogen o r phosphorus, but i t would be dangerous to dogma-tise on the evidence available. I feel t h a t the name I have placeda t the head of this section is, so long as we are ignorant of thensture of these substances, to be preferred t o that of vitamines.The Enzymes of Blood and the Action of Serum on other Eiazymes.The Abderhalden reaction, which was discussed i n my lastReport, has formed the subject of a number of papers publishedduring the year.It has also stimulated interest in the bloodferments generally.As regards the reaction itself, opinions still differ as to its speci-ficity and trustworthiness. Some report favourably.47 One observerfound t h a t the optical and dialysis methods harmonised in twentyout of twenty-eight cases, and that in nineteen of these they werein agreement with clinical diagnosis.48 It is stated t h a t whendifferent organs in the body are ligatured off from the circulationand the serum then tested by Abderhalden’s methods, a proteolyticferment is found in the blood.This is specific for the organ whichwas cut off from the circulation, and does not act on the proteinsof other oxgans.On the whole, however, the weight of the evidence is againstthe specificity of the Abderhalden reaction, and doubt has beenthrown on the accepted views as to its nature. It has been claimed,f o r instance, t h a t normal serum shows non-specific proteolyticactivity so soon as its content of anti-trypsin is removed.49 I n46 Lac. c i t . 43 J. Biol. Chem., 1915, 20, 382; A . , i, 477.46 Ibid., 1915, 21, 91; A . , i, 623.47 Compare J. Rosenbloom, Biochem. BUZZ., 1914, 3, 373; A., i, 42.49 J. and K. M. Scott, Proc. SOC. Expt. Biol. Med., 1915, 12, 137; A . , i, 472.‘4 LOG. cit.G. Hiilsen, Biochem.Zeitsch., 1914, 67, 277; A., i , 340.also J. Bronfenbrenner, Biochcni. Bull., 1915,4, 87 ; A , , i, G 2 G PHYSIOLOGICAL CHEMISTRY. 203pregnancy, on this view, the anti-substance combines with theplacenta antigen, and 50 sets free the one and only protease whichis present in all seruiri. I n the Abderhalden test i t is not theplacental substrate which is digested, but the serum itself. Othersclaim t h a t normal serum has a weak proteolytic activity of its own,even when it. has received no treatment of any kind. This increaseswith age of the individual, and is also increased in conditions otherthan pregnancy.50The blood undoubtedly contains an amylase, and starc? injectedinto the circulation is saccharified.51 The amount of amylasepresent does not, however, depend on the diet o r feeding habitsof the animal, for the seruni of the goat, which is entirely herbi-vorous, has only about one-twelfth the ainylolytic activity of t h a tof the dog or cat.The ferment is almost certainly derived fromthe pancreas and salivary glands. Pancreatic disease leads t o adiminution i n the blood- and urinary-amylase.52 For some reasonremoval of the pancreas also reduces the nuclease content of theblood and tissues.53The factor in serum which accelerates the fat-splitting power ofpancreatic juice (auxolipase) is distinct from the co-enzyme withthe same action contained in the pancreatic extracts, since i t isnon-dialysable. It is, however, thermostable. Mellanby andWoolley have suggested t h a t serum activates lipase merely becauseit contains anti-trypsin ; this prevents the destructive action whichtrypsin otherwise exerts on the fat-splitting ferment.This does notPeem t o be the case. K. Isuji b4 and J. A. Shaw-Mackenzie 55 haveindependeiitly shown t h a t there is no parallelism between theamount of anti-trypsin in the serum and its power of acceleratinglipolysis. The latter observer finds also t h a t when the serum isheated to a temperature sufficient t o destroy anti-trypsin it stillexhibits marked influence on lipase.The frequency with which the serum affects, in one sense oranother, the velocity of enzyme reactions is a noteworthy physio-logical fact. The last case t o be studied is t h a t of urease. Thesera of various animals greatly accelerate the action of theferment of t h e soja bean.Human serum increases it about eight-fold, and the amount of the auxo-urease is here very constant, beingseemingly unaffected by the most varied pathological conditions.5660 L. H. Sloan, Amer. J . Physiol., 1915, 39, 9 ; A . , i, 1077.5l H. McGuigan and C. L. von Hem, ibid., 36, 359; A . , i, 186.b2 C. E. King, ibid., 1914, 35, 301; A . , i, 3 5 ; V. Stavraki, Biochem Zeitsch.,1915,69, 370; A . , i, 735.53 Stavraki, loc. cit.55 J. Physiol., 1915, 49, 216; A . , i, 473.66 R. Neumann, Biochem. Zeitsch., 1915, 69, 134; A . , i , 613.54 Biochem. J., 1915, 9, 53; A , , i, 473.H* 204 ANNUAL REPORTS OH THE PROGRESS OF CHEMISTRY.Au active preparation can be prepared by precipitating sheep’sserum witli alcohol and extractin? the precipitate witli water. Itis remarkable that the subqtance t Iiur ol)tained is, unlike the naturalauxo-6ubstance, dialysable and not destroyed by peptic digestion.577qt teriial Secretions.It is now some time since attention was given in these Reportsto the organs of internal secretion.No progress of a startling sorthas been made during the last year o r two, but some useful workmay be chronicled. Attention has been given in particular t o thepituitary body, the importance of this gland t o the organism beingnow very clear. The history of our knowledge concerning theorgan was brought up t o date by Professor Halliburton in hisReport for the year 1909. On the chemical side the facts knownup t o 1913 are given by Barger in his very useful book, “TheSimpler Natural Bases.” 58To the earlier-known physiological effects of extracts of thisgland (a direct stimulation of involuntary muscle and a diureticaction) there have been more recently added a power t o increasethe flow of milk and stimulate the ovary.These last functionshave received some attention during the year. The galactagogueaction was first observed by Ott and Scott,5Q and was studied insome detail by J. Hammond.60 Hammond found that the injectionof pituitary extracts produce an immediate increase in the flowof milk which is followed by a period of decreased flow, the actualdaily yield being only slightly increased as the result of the injec-tion The milk formed is particularly rich in fat.This authorbelieved t h a t the effect was not on the muscles of the mammarygland, but on the epithelium cells, a true secretory stimulus. R. L.Hill and S. Simpsono1 found t h a t when ox-pituitary extract isinjected into the goat there is a marked increase in the amount ofmilk obtained fifteen minutes later; the next milking, a few hourslater on, shows a. corresponding decrease. The same authors testedthe effect of pituitrin on a human subject.62 The injection of20 milligrams of the dried infundibular portion of the gland into awoman during lactation was followed in ten minutes by a note-worthy increase in the amount of milk secreted. The milk with-57 M. Jacoby and N. Umeda, Biochem. Zeitsch., 1915, 68, 23; A ., i, 186.6 * Monographs on Biochemistry, Longmans, 1914.69 Therap. Gazette, 1911.61 Ibid., 1914, 8, 103; A., i, 45.O2 Amer. J . Physiol., 1914, 35, 361; A , , i, 45.Quart. J. ezppt. Physiol., 1913, 6, 311; A . , 1913, i, 1133PHYSIOLOGICAL CHEXISTRY. 205drawn after the injection was rich in fat, containing 5 5 per cent.as against 3.5 per cent. in the milk produced without pituitrin. I nthe milk produced a day after the injection the f a t was still 531118-what above the normal.The authors just quoted hold, like Hamniond, t h a t tlie actionis on the secretory cells, and not on the muscular tissue, sincebarium chloride, a specific stimulant of muscle, causes no milkflow. E. A. ScliCfer,63 however, criticises their conclusions, andmaintains t h a t the discharge of milk is due t o the contraction of thesmooth muscle in the walls of the glandular alveoli.A secondinjection of pituitrin does not, he states, yield any milk untiltime has been allowed for fresh secretion to accumulate. It is notcertain, Schafer holds, t h a t barium chloride acts on the muscleof the gland, whereas pituitrin is known to act powerfully on most,if not all, smooth muscles. W. L. Gaines,64 experimenting withgoats, confirms Schafer's conclusions. 1,. A. I. Maxwell and A. C. H.Rothera,G5 however, strongly support the view t h a t pituitrin is atrue secretory stimulant. They point out t h a t when injections aregiven immediately after milking, the amount of milk immediatelyobtained is too large in amount to arise from a further emptyingof the exhausted gland by muscular contractions.On measuring theintramammary milk pressure they found that the rise in this duet o pituitrin is a gradual process, and the increased pressure is longmaintained. If the action were merely on muscles a rapid initialrise would be expected, followed by a fairly rapid fall. It is cleart h a t the nature of the mechanism of the action is still uncertain,and t h a t some crucial experiment must be devised capable of givinga definite decision. It would certainly be of interest to be surethat the gland possesses a specific action on mammary gland cells.The economic importance of the artificial use of pituitrin in thisconnexion is probably negligible, since the immediate increasein the milk would seem to be always followed by a compensatoryfall.Several observers have shown during the last year or two thatpituitary extracts have a stimulating action on the ovary. Thishas led certain American workers 60 try if it be possible by adminis-tering pituitrin to increase the output of eggs by the domesticfowl.Injection of extracts of the anterior lobe into the abdominalcavity during tlie period of moulting had no effect,66 but the samepart of the gland when taken from growing mammals and given by6J Quurt. J . Ezpt. Phghiol., 1915, 8, 399; A , , i, 1'31.6 5 J. Physiol., 191.5, 49, 463; .4., i, 1033.-1mer. J . PhysioZ., 1915, 36, 360; A., i , 191.R. Pearl and F. 11. Surface, J . Biol. C'hem., 191.5, 21, 9 5 ; A , , i, 620206 AX'KUAL REPORTS ON THE PROGRESS OF CHEI\IIS'lRY.the mouth is stated t o have produced a noteworthy increase in eggproduction.67We have as yet no definite knowledge as t o the chemical natureof the active principle o r principles contained in the pituitary body.The evidence seems to point t o the existence of more than one.Farbwerke vorm.Meister, Lucius & Briining by the use of pll05-photungstic acid as a precipitant obtained a crystalline sulphate,G*which Fuhner 69 afterwards separated by fractional crystallisationinto four different substances, all of which seemed t o contributeto the activity of the gland. F. Hoffmann, La Roche & Co. havealso patented a method of obtaining a crystalline product. Duringthe preparation of this last product evidence of more than oneactive principle also came t o light.A substance acting on theintestines appeared to be more soluble in chloroform than anotheracting on the blood vessels and uterus.70 A. Hunter's71 work seemsalso t o show t h a t different actions of the gland may be due t odistinct substances.Extracts of the organ give Pauly's histidine reaction, and thereis considerable probability t h a t one a t least of the active constitu-ents is a histidine derivative. T. B. Aldricli was unable to obtainother histidine reactions, but, as H. Pauly72 points out, the diazo-reaction is twenty to fifty times more delicate than any other,and its significance should not be disregarded because others fail.M. Guggenheim 73 calls attention to resemblances between the actionof the pituitary substance and t h a t of acetylcholine.He believest h a t the gland contains an ester-like derivative of an alkanolaminewith an acetyl residue.I n about 10 per cent. of the glands removed from the ox colloidmasees are found between the two lobes. F. Fenger74 has examinedthese, but finds the substance is without physiological action. Ionly mention his paper t o record the fact that in preparing thecolloid for study he used material derived from a t least 30,000cattle, This illustrates how difficult i t may be to work a t somedetails of tissue chemistry for those who are not, like the authorquoted, in touch with such sources of supply as the firm of Armourof Chicago !\Vhen iodine was first discovered in the thyroid gland by67 L.K. Clark, .Amer J P h y s i o l , 1915, 22, 485; z4., i, 1031.68 See A., 1914, I , 7 5 6 .69 Zeitsch. f . d . yes. m p t . Med., 1913, 1, 3977 0 See *4., I , 857.71 Qunyt. J . Ezpt. Phy,iol., 1914, 8, 243, 267.7: Zeitsch. physiol. Chem., 1915, 94, 427; A , , i , 917.73 BLochenL. Zeitsch., 1914, 65, 189; A., 1914, i, 1021.74 J . Biol. Chem., 1915, 21, 288; A . , i, 739PHYSIOLOGICAL CHEMISTRY. 207Bituiiian~i, it wab generally assumed that the organic iodine com-pound present was responsible for the peculiar activities of theorgan. Later on, for a period, this was doubted, in particularbecause it was believed t h a t glands known t o be normal in functioncould be shown h be free from iodine.Of late evidence 1ia.s accu-mulated to show t h a t the earlier opinion was right. Improvedmethods of detecting the halogen have demonstrated its presencewhere it was missed before, and although the amount present inthe organ varies through a wide range i t is probably never absent.A. T. Cameron75 in three very full reports has given an accountof the distribution of iodine in the tissues of animals and plants.Many interesting data are collected o r supplied. All marine speciesof animals contain iodine. As advances in evolution are madethere is more differentiation in the distribution and probably lesstotal iodine in the whole organism. Much of the material whichhas been found t o contain the element is in the nature of anexternal secretion (a secretion on the outer surface of the body).Ofvertebrate tissue the thyroid alone is of importance in connexionwith the storage of iodine. Fenger has found that human f e t a lthyroid contains iodine during the last three months of pregnancy.'GThe limits in the amounts found in dry thyroid are 0.01 and 1.16per cent.77 There seems little doubt t h a t the main cause of thevariation is t o be sought in the diet.During the administration of iodides (to dogs) the thyroidgland is the only organ retaining organically combined iodine.It is the only organ capable of transforming the inorganichalogen into iodine-protein compounds and of thus acting as astorage f o r iodine in the body.78 The quite special affinity ofthyroid tissue f o r the element is demonstrated by the observationsof D.Marir1e.7~ In one set of experiments various isolated organswere perfused with a mixture of blood and Ringer's solution t owhich potassium iodide was added. Only the thyroid retained theiodine, and this only during the period of its survival. The deadtissue retained none. I n other experiments iodides were fed tothe living animal. -4s much as 18.5 per cent. of the iodide givenwas retained in the thyroid, with none elsewhere, and this whenthe weight of the gland was t o the body-weight in the ratio ofonly 1 t o 687.7 5 J. Bid. Chem., 1914, 16, 465; A . , 1914, i, 227; i b i d . , 1914, 18, 335;-4., 1914, 1, 1154; ibid., 1915, 23, 1.7 7 The highest figure refers to the gland of an elasmobranch fish.I n themammal the maximum found is 0.629 per cent. (dog's thyroid). On thissubject see also Hunter and Simpson, J. Bid. Chem., 1915,20, 119; A . , i, 192.78 F. Blum and R. Griitzner, Zeitsch. physiol. Chem., 1914,92,360; A , , i, 343.79 PTOC. SOC. ezpt. Biol. Med., 1915,12, 132; A . , i, 478.76 Ibid., 20, 695; A . , i, 620208 ANh’UAL REPORTS ON THE PROGRESS OF CHEMISTRY.These recent experiments confirm very fully the fact that thereexists within the thyroid a specialised chemical mechanism for tliearrest of the halogen in an organic form. The proof of so specifica property in a particular tissue has general bearings, and makesit easier to believe in highly selective tissue affinities in other caseswhere tlie concrete chemical facts are less easy to demonstrate.It would seem from the work of J.M. Rabe, J. Rogers, G. G.Fawcett, and S. P. Beebeso that stimulation of the vagus canundoubtedly cause discharge of iodine compounds from the glandinto the blood, an important observation in connexion with therelation between the nervous system and hyperthyroidism.If iodo-protein compounds are responsible f o r the physiologicalproperties of the organ, it would be interesting t o know whetherthese properties are attached to the complex as a whole or whetherthey are more particularly due to some amino-acid grouping withinthe protein molecule; the group, o r groups, that is, with which theiodine is directly associated. From what we know of artificialhalogen-proteins we should expect the iodine t o be associated withone or more of the aromatic groups.It is noteworthy, therefore,to find t h a t certain effects produced by the thyroid are also broughtabout by di-iodotyrosine. Thus M. Morse81 has shown that accelera-tion of the metamorphosis in tadpoles which is seen on feedingwith the gland is also produced when 3:S-di-iodotyrosine is given.The metamorphosis may occur in three days instead of requiring thenormal fortnight. C. H. Frazier and M. M. Peet@ state thatdi-iodotyrosine acts like extracts of the gland in slowing the rate ofsecretion of cerebrospinal fluid.E. C. Kendalls3 claims, on the other hand, to have shown thatpart a t least of the iodine of tlie gland is in association with theindole nucleus.After hydrolysing the gland tissue with 1 per cent.sodium hydroxide in 90 per cent. alcohol he isolated a productidentified as di-iodohydroxyindole. This is stated t o have givenresults on administration similar t o those of thyroid feeding. Ifthe observation should be confirmed it is certainly one of greatinterest.Uric Acid in Blood.I have devoted no section to purine metabolism this yearas, f o r the most part, the work done is unimport.ant, but i tis essential t o note a paper by S. R. Benedictsd dealing with theso -4mer. J . Physiol., 1914, 34, 72; A . , 1914, i, 022:J . Bid. Chem., 1914, 19, 421; A . , i, 45.81 Amer. J . Physiol., 1915, 38, 93; 8., i, 737.83 J . Amer. Med. Assn., 1915, 64, 2042; see also J . Biol. C ’ h e i ~ . , 1915, 20,501 ; A . , i, GOO. J . Bid. Chem., 1915, 20, 033; A . , i, 612PHYSIOLOGICAL CHEMISTRY. 202)existence of conjugated uric acid in mammalian blood. If thefindings of the author are confirmed and shown to have generalbearings they will considerably modify a11 future studies of uricacid in health and disease. Using a colorimetric method previouslydescribed by himself, Benedict found t h a t ox blood yields on theaverage half a milligram of uric acid. This we should have hithertorecognised as being the total content of t h a t substance. It was,however, accidentally observed t h a t after certain treatment of theblood the uric acid increased t o a remarkable degree, and finally i twas discovered t h a t if the blood proteins be removed with colloidaliron and the filtrate concentrated in the presence of hydrochloricacid the amount of uric acid found may show an increase over the“free” acid of as much as 1000 t o 1300 per cent. It was thenfound t h a t the combined uric acid is gradually liberated in theblood by the action of an enzyme present. Ox blood containingonly 0.5 milligram when fresh yieIded 7 . 5 milligrams after remain-ing for a fortnight in the presence of antiseptics. Whatever thenature of the combination may be in which uric acid exists i t iscertainly not associated with protein. The remarkable fact nextcame t o light t h a t whilst in the mammalian blood the uric acid iswholly contained in the corpuscles, in bird’s (chicken’s) blood i t isalmost entirely confined t o the serum. These relations have not beensuspected hitherto. It is clear t h a t they have important bearings onthe physiology of purin metabolism, Benedict wisely avoids specula-tion on the subject until further experiments have been made, buti t is tempting, a t any rate, t o believe t h a t uric acid which can befurther metabolised circulates in combination, whilst that which ist o be directly eliminated circulates free.Conce/ztrcctio/L of A n t i g e n s .G. S. WalpoleBj has described very valuable methods forstandardising collodian filters suitable for ultrafiltration ” andpressure dialysis operations. Certain members of the standardseries, defined by their weight and content of nitrogenper sq. cni., are especially valuable for separating antigens. Theyare impermeable t o all such, although allowing water-salts andrimpler molecules t o pass freely. I n a paper published withA. T. Glenny he illustrates the use of his method. I n particular,a process f o r the concentration and purification of diphtheria toxinis fully described. The paper makes i t clear t h a t a very definiteadvance in technique has been reached. The membranes areirnpernieable t o enzymes, but allow to pass secretin, the pituitaryactive principle, the co-enzyme of zymase, and the toxic constituentof Witte’s peptone.e5 Biocheni J . , 1915, 9, 284; .I., ii, j4‘3.F. G. HOPKIKS

ISSN:0365-6217    

DOI:10.1039/AR9151200187

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.THE year 1915 has not differed much from previous years eitheras regards the number of investigations published or the import-ance of the results obtained, and no results of obviously outrstanding interest have t o be recorded.Among publications may be mentioned the If Journal of the Asso-ciation of Official Agricultural Chemists,” which will contain theProceedings of the Annual Conventions, formerly published asBulletins of the Bureau of Chemistry, U.S. Department of Agricul-ture; Soils: their Properties and Management,” by T. L. Lyon,E. 0. Fippin, and H. 0. Buckman; ‘ I Soils and Plant Life as Relatedto Agriculture,” by E. J. Russell; and ‘‘ Die Ernahrung der land-wirtschaftlichen, Kulturpflanzen,” by W.Schneidewind.The Atmosphere.A series of analyses of daily collections of rainwater, extendingmer fourteen months, has been made a t Melbourne and a t Canter-bury, six miles distant, in which the amounts of nitrogen asnitrates and nitrites were estimated.1 At Canterbury the totaloxidised nitrogen amounted to 0.503 kilo. per hectare per annum,and the relation of nitric to nitrous nitrogen was about 1 O : l .I n the summer months the concentration of nitrous nitrogen wasless, and in winter much higher, than the average f o r the year,whilst the nitric nitrogen was highest in the autumn and summer,and lowest in winter.Although local thunder-storms increase the amounts of oxidisednitrogen in the air, their effect is comparatively slight, and someof the highest results were obtained when there was no storm.The highest amounts of oxidised nitrogen occur when the airthrough which the rain falls has circulated over an area which has,for a long period, been subjected to continuous electrical discharges.The rain collected during Lropical storms of the extreme summertype brought down 0.039 kilo.of oxidised nitrogen per hectare;in the usual summer type of tropical depression the average amountwas 0.026 kilo., and in spring and autumn depressions 0.018 kilo.1 V. G. Anderson, Report Brit. Assoc., 1914, 338; 8., i, 860; &uo.rt. J . Roy.M e t . Soc., 1915, 41, 99.21AGRICULTURBL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 211Very different results were obtained with antarctic depressions,when the average amounts of oxidised nitrogen varied from 0'0017to 0*0046 kilo.according t o the type.It seems doubtful whether t h e conclusions drawn from therelation of nitrous t o nitric nitrogen axe quite justified. Whilstseveral results obtained in other localities also show higher amountsof nitrites in the summer than in the winter months, this doesnot invariably seem t o be the case. It must also be borne in mindt h a t t h e rain falling after a period of fine weather will wash outthe nitrates accumulated during the whole period, whilst the nitrousacid, unless present in the more stable form of salts, will onlyrepresent the last day o r two.The investigation, which is tha first satisfactory attempt tocorrelate the amounts of constituents found in rain and the weatherconditions, seems t o promise interesting results, and it shows thedesirability of adequate meteorological data in connexion withinvestigations of a i r and rain.A t Ottawa t h e series of analyses of rain-water, now in its eighthyear, has been continued,2 and estimations of organic, nitric, andnitrous nitrogen, ammonia, chlorides, and sulphates have beenmade a t Mount Vernon, Iowa.3Soils.I n addition t o the movements of water in soils caused by gravi.ta.tion and capillarity, i t has been shown t h a t soil water is subjectt o osmosis.4 Experiments were made in which a column of soil,6.5 cm.deep, wes employed as semi-permeable membrane, and aconcentrated soil extract as solution. Results were obtained show-ing an osmotic pressure equal to t h a t of a column of water about3 m.high. The soil resembles the usual semi-permeable mem-brane, being probably in a colloidal state, and in absorbing watermore readily than a soil solution, so t h a t the movement is towardsthe soil solution as the liquid least absorbed.Investigations of Japanese soils 6 have shown t h a t when steepedin different solutions the increase in volume varies according t othe substance employed, being greatest in alkalis, next in acids,then in solutions of salts and in wates, and least in alcohol.The gel forms vary according to the reagent employed, and thesoil constituents from which they are formed are not uniformsubstances. When soils are dialysed and the residues compared2 F.T. Shutt, Trans. Roy. SOC. Canada, 1914, [iiil, 8, 83; A , , i . 836.3 W. K. Knox, Chern. News, 1915, Ill, 61; A . , i, 204.C. J. Lynde, and J. V. DuprB, Proc. Roy. SOC. Canada, 1914, [iii], 8, 133;T. Tadokoro, J. COG. Agric. Tohoku, 1914, 6, 27, 117; A., i, 636.A., i, 76221.2 ANIVUAL REPORTS ON THE PROGRESS OF CHEMISTRYwith the original soils it is found t h a t the differences are veryslight; the colloids which dissolve in water are, therefore, not ofimportance in this connexion.I n accordance with van Bemmelen's results, i t is shown that tliepowers of adsorption of dyes and nutritive solutions possessed bysoils diminishes with dilution. The adsorption of dyes is closelyrelated to the changes in volume and to the hygroscopicity, allbeing intimately connected with the amounts of solid colloidspresent..The power of absorbing ammonia, on the other hand,seems to be more complicated, and has no regular relation t o theadsorption of dyes, the increase in volume, and the hygroscopicity,which depend only on the surface of the colloid portion of thesoil. The coefficient of ammonia absorption is greater in normalammonium phosphate than in normal ammonium chloride, prob-ably owing to the liberated phosphoric acid forming insolublecompounds with aluminium.Comparing different kinds of soils it is found t h a t the increasein volume and the adsorption of dyes is greatest in humus soils,less in clay soils, and least in sandy soils. I n the case of hygro-scopicity the order of humus and clay soils is reversed.With mineral-acid soils the increase in volume is greater thanwith neutral soils containing plenty of humus, but it is sometimesless than that observed with neutral soils deficient in humus.The differences in increase in volume observed with differentreagents are much greater in the case of mineral-acid soils thanwith neutral soils, indicating t h a t the colloids of the acid soilshave mobile, unstable forms.Hygroscopicity does not seem tovary much in the different acid soils as compared with the neutralsoils. The adsorption of dyes and absorption of ammonia areusually greater in mineral-acid than in neutral soils ; there is,however, no great difference between the lowest results obtainedwith the former and the highest obtained with the latter.With reference to the acidity of upland soils containing verylittle organic matter, which has been attributed t o absorption ofbases by colloids, it has been pointed out that the silicates reactwith soil solutions forming a soluble hydroxide, o r salt, which iseither assimilated by plants or else removed in drainage, and acomparatively insoluble acid silicate.6 The failure of acid soilst o take up equivalents of the different bases from salt solutions,which is partly responsible f o r the colloid theory, is clue t o t h esparing solubility of the acid silicates and their neutralisationproducts.When tlie opportunity for secondary reactions is eliniiliated asf a r as possible by treating very finely powdered soil with large6 E.Truog, Science, 1915, N S., 42, 505.iGRICUJ.’RJRAT, CHEMISTRP AXD VEGETABLE PHPSIOLOGY. 213mnounts of salt solution far a short time, i t is shown that verynearly equivalent amounts of the different bases are taken up.Soil acidity can be estimated by stirring 25 grams of soil, mois-tened with 35 C.C. of water, with an excess of barium hydroxidesolution f o r one minute, after which carbon dioxide is passedthrough. The whole is then evaporated to dryness and the excessof barium liydroxide ascertained by estimating the carbonate. Thefact t h a t either sodium, barium, or calcium hydroxide may be em-ployed is evidence t h a t the acidity is due to acid, and not to colloids.The results of a number of experiments with different soils7showed t h a t i n order to obtain a knowledge of the amount ofcalcium carbonate which should be applied, it is desirable toertimate the acidity rather than the carbonates present.Carbonatesmay be absent in neutral soils and present, locally, in acid soils.It was found that addition of calcium carbonate t o soils, accordingto the acidity as indicated by the bicarbonate method, a t onceshowed increased ammonia production and greater plant growthin pot cultures. Calcium carbonate and oxide have the same effectuntil the point is reached a t which the acidity is neutralised, afterwhich the oxide has partial sterilisation effects, to which referencewill be made later on.Some interesting results were obtained by estimating the acidityof different samples of the same uncultivated soil which wereselected according to the predominating plants.Taking theextremes, it was found that the percentage amount of lime requiredby the soil with wild white clover was 0.22, whilst the sorrel soilshowed a requirement, of 0.53 per cent. The soils with Festuca,gorse, and Yorkshire fog occupied intermediate positions.The results of pot experiments in which clover was grown in asandy clay loam, showing a lime requirement of about 0’06 percent., indicated t h a t low yields are obtained when a great excessof precipitated calcium carbonate is applied.8 High results wereobtained, however, when calcium was applied as silicate (wollas-tonite), with magnesium silicate (serpentine), and with a mixtureof calcium and magnesium silicates.I n a silty loam of the sameacidity the growth was in each case very much less; much thehighest results were obtained with the mixed silicates.Investigations on the calciphobe behaviour of lupines have some-times given conflicting results, and it has not yet been possible toobtain any quite satisfactory explanation. The results of experi-ments extending over three years9 seem to show, i n agreement7 H. B. Hutchinson and K. McLennan, J . A g k . Bci., 1915, 7, 55.8 W. H. MacIntyre and I,. G. Willis, J. I n d . Eng. Chem., 1914, 8, 1005;9 T. Pfeiffer and E. Blanok, Mitt. tandw. Inst. Univ. BTeslau, 1914, 7, 201 ;A , , i, 52.A., i, 201214 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,with results obtained in earlier investigations, t h a t one injuriouseffect of the application of calcium Carbonate is to prevent theassimilation of sufficient iron ; there is, however, no doubt tliatother injurious actions take place. Limestone is found t o be lessiiijurious t o lupines than precipitated calcium carbonate, andcalcium sulphate, although injurious, is less so than carbonate;lupines manured with gypsum take up less calcium than whencarbonate is applied.Calcium nitrate has an unfavourable effectwhen applied along with the carbonate ; potassium nitrate has,however, the same effect, so t h a t the increased injury must, in bothcases, be attributed to the physiologically alkaline reaction of thenitrates.Applications of limestone to lupines has a retarding effect onthe formation of root-nodules, and consequently on nitrogen assimi-lation; it also has a marked effect on the assimilation of phos-phoric acid, except when ammonium sulphate is applied as well.Soil Gases and Aeration.An examination of the air of soils collected a t a depth of 15 cm.has shown t h a t the free air is very similar in composition toatmospheric air, but t h a t i t contains more carbon dioxide andcosrespondingly less oxygen, and shows greater variations incomposition.10 The sum of the percentages of the carbon dioxideand the oxygen is usually only slightly less than t h a t of the atnio-sphere; there is, however, a perceptible fall in the amounts ofoxygen during periods of active nitrification, and a still greaterfall in wa.ter-logged soils.This free air does not represent the whole of the gases presentin soils.By keeping a mercury pump a t work f o r several daysafte? the flask containing the soil has been exhausted, a furthersmall amount of gas is obtained from the water and colloids ofthe soil, consisting mainly, and finally almost exclusively, of carbondioxide with very little, if any, oxygen. These results suggest thepossibility of simultaneous aerobic and anaerobic bacterial activityin soils.Confining attention t o the free air of the soil, it is showq t h a tthe fluctuations in composition depend mainly on fluctuations inbacterial activity, and t h a t the curves are similar t o those showingthe amounts of nitrate and the numbers of bacteria. The maximumvalues occur in the late spring and again in autumn, whilst theminimum values occur in summar and winter.I n the autumn thebacteria increase first, then the carbon dioxide, and finally thenitrates. From November t o May the curves closely follow thosefor the temperature of the soil, which seems to be the dominating10 E. J. Russell and A. Appleyard, J . Agric. Sci., 1916, 7, 1; A , i, 635AGRICULTURAL CHEMISTRY Ah’D VEGETABLE PHYSIOLOGY. 215fartor, and from May to November they follow the rainfall, and,t o a less extent, the soil moisture curves, the beneficial effect ofrain, apart from soil moisture, probably Iieing due t o tlle dissolvdoxygen.Grass-land usually contains more carbon dioxide and less oxygenthan arable land; there was, however, no evidence to show t h a t agrowing crop has any marked influence in increasing the amountof carbon dioxide in the soil air.Weather conditions, such asbarometric pressure, wind velocity, and variations from the meantemperature, do not seem to have any important influence on theatmosphere of the soil.I n India a very comprehensive investigation of soil gases hasbeen made in which the total amounts of soil gas and the amountsof its various constituents (including argon, hydrogen, andmethane) were estimated in samples obtained under differentconditions.11Experiments with Bihar alluvium showed t h a t whilst the volumeof water was increased during rains t o about four times the amountpreviously present, the volume of gas is usually not decreased t oone half.The gases from swamp rice-land showed high ratios of nitrogento argon, indicating liberation of soil nitrogen.Considerableamounts of hydrogen were found, as well as some methane, whilstthe percentage of oxygen was very low.Soil samples obtained near roots of different crops, yielded gasescontaining very large amounts of carbon dioxide, very smallamounts of oxygen, and almost always some hydrogen, b u t nomethane. Hydrogen was found near the roots of three differentcrops-san hemp, indigo, and maize.As regards the influence of nitrification on the soil oxygen, it isshown t h a t after abundant nitrification, resulting from a heavy rainin June, the soil contained almost the same amount of oxygen asbefore.From these results, and some others obtained in experi-ments on nitrification in closed vessels, with both small and largeamounts of air, the conclusion is drawn t h a t the diffusion of gasesin soils is sufficiently rapid to prevent a deficiency of oxygen. Itshould, however, be borne in mind t h a t the rain must have con-tributed a good deal of dissolved oxygen, and t h a t the water perco-lating through the soil will draw into the soil large amounts ofair from above. The assumption t h a t aeration, as a n importantresult of tillage, is put out of court by these results, and that thebenefits of tillage must exclusively be due to other effects, doesnot seem t o be very probablel1 J. W. Leather, Mem. Dept.Agric. India, Chern. Ser., 1915, 4, 85; A , ,1916, i, 110216 ANNUAL REPORTS OX THE PROGRESS OF' CHEMISl'RY.It has been found in Russia12 that the best crops of wintercereals are obtained after the so-called black fallow and tlie Aprilfallow, and that a definite connexioii exists between the mannerof working tlie fallow and t h e hurrlidity of the soil. I n order toascertain the effects of the different types of fallow on aeration,four types were selected for investigation : the black fallow, whichbegins in the autumn, the April fallow, and two June fallows, onecf which is characterised by the soil being much trodden by cattleput on to graze. I n soil samples collected from June t o Sep-tember lst, it was found that the black fallow soil contained51-81 C.C.of oxygen per litre, April fallow soil 65-81.4 c.c., andthe June fallow soils, without and with cattle, 52-65 C.C. and32-48 C.C. respectively. A t the time of sowing (August 1st) therelative amounts of oxygen with the four fallows were 100, 107,86.5, and 54.2 C.C. I n April, samples of the soil under rye wereexamined in order to show the effect of the winter season, and itwas found that the amounts of oxygen in the soils (taking thefallows in the same order as before) had fallen to 49.3, 45.4, 43.5,and 24.0 C.C. per litre of soil.Further experiments on the influence of temperature, diffusionof gases, percolation of water, and wind on the composition of thesoil air showed t h a t percolation of water during periods of rainis the most active factor.I n the alluvial soils of the Indo-Gangetic plain aeration is diffi-cult, owing t o the readiness with which hard crusts are formedafter heavy rain or irrigation, and in some parts to the rise ofthe water table t o within a few feet of the surface.13 The cropsin these regions frequently suffer from asphyxiation, and can onlybe saved by breaking the crust and aerating t o as great a depthas possible.Deficient aeration has also been observed on similarsoils under quite different climatic conditions. When greenmanuring is adopted, the necessity f o r aeration is still moremarked, and it is suggested t h a t the injury to fruit trees causedby grass is due to excessive production of carbon dioxide. Thereis, however, no direct evidence t o support this view.Under other conditions, it has been found t h a t green manuring,besides acting as a manure, actually increases, indirectly, thesupply of oxygen in the soil.14 I n swamp rice soils it has beenshown t h a t the surface becomes covered by an organised film con-l2 A.G. Dojarenko, Bull. Agric. Intell. Plant Diseases, 1915, 6, 1299.la A. Howard and G. L. C. Howard, Bull. Agric. Research Inst. Puaa, 1915,l4 W. H. Harrison and P. A. Subramania Aiyer, Mcm. Dept. Agric. India,No. 52.Chem. Ser., 1914, 4, 1 ; A . , i, 202AGRICULTURAL CHEMISTRY A S D VEGETABLE PHPSlOLOGY. 217taining bacteria which oxidise hydrogen and methane and producecarbon dioxide, which is assimilated by a l p with liberation ofoxygen.The activity of the film bacteria is increased by greenmanure, and this gives rise t o a n increased production of oxygen.The oxygen dissolved in the water entering the soil is, however,one of the chief factors on which the crop dependsAn investigation on the production of nitrates in the black soilsof the arid regions in Russia, extending over several years, showedthat, under favourable conditions of tilth and temperature, nitrifi-cation may be very active, and nitrates may accumulate in con-siderable amounts.1: Comparing the different fallows, t o whichreference has been made in conliexion with aeration, it is shownt h a t the greatest amount of nitrates is produced on the black”fallows and the April fallows, the greatest accumulation beingfound towards the beginning of August, The sooner the fallow isploughed in spring the greater the accumulation of nitrates.Thedepth to which cultivated land is ploughed seems t o have no greatinfluence.I n plots with winter cereals, the nitrates diminished rapidly,being, to a great extent, taken up by the crop. When the soil isbroken up after the harvest of winter cereals, nitrates may beformed i n considerable amounts by the end of September providedt h a t the weather is favourable. The results accord with the resultsof crop experiments on the different fallows, and they indicatethat aeration is of greater importance than temperature.On these soils, applications of dung result in only slightlyincreased production of nitrates.HlI?ll118.Whilst a good deal of progress has been made in recent yearsin our knowledge of the various definite organic compounds whichoccur in soils, it cannot be said t h a t recent investigations on humushave resulted in any very material advance. The papers pub-lished in 1915 deal mainly, not with soil humus, but with the sub-stances obtained by the action of acids on carbohydrates andproteins.When zein and tryptophan are hydrolysed separately, nointensely black solution is obtained.16 With a mixture of the twosubstances there is, however, a rapid development of an intenseblackness, and the addition of dextrose t o tryptophan enable5about 90 per cent.of the nitrogen of the tryptophan to be re-l6 R. A. Gortner aiid M. J. Ulibli, J . Awer.C‘he/u. boc., 1915, 37, lti30;S. M. Toulaikoff, Bull. A g r i c . IlLtelZ. Plailt L ) ~ ~ e c r o c i , 1915, 6, 795.A . i. 7 2 6 218 ANNUAL REPORTS O S THE PROGRESS OF CHEMISTRY,covered as humin. No humin was obtained from a mixture ofhistidine and a carbohydrate.As carbohydrates yield small amounts of furfuraldehyde whenboiled with mineral acids, it is suggested that in the productionof humin the reaction involved is a condensation of tryptophanwith an aldehyde.The artificial humic acids hitherto obtained from sugar by theaction of acid contain more carbon than humic acid from soil. Ithas been found, however, t h a t when natural humic acid is extractedwith absolute alcohol, the product ha5 the same composition ashumic acid from sugar." It is not clear what became of thenitrogen of the humic acid obtained from peat.By boiling mucin and egg-albumin with hydrochloric acid foreight hours, 2 to 3.5 per cent.of humic acid was obtained.Caseinogen and purified egg-albumin, on the other hand, yieldedpractically no humic acid when subjected t o the same treatment.I n order to throw some light on the value of soluble humus asa food for plants, pot experiments have been made in which foursuccessive crops-wheat, mustard, rye, and mustard-were grownin garden and arable soils, and in the same soils after removingnearly all the soluble humus by extracting with 2 per cent. sodiumhydroxide The first crop gave better yields, and took up morenitrogen in the extracted soil than in the original soil; and infive out of eight cases the extracted soils parted with rather morenitrogen than the unextracted soils.By combining all the resultsobtained with the four crops in each case, it is shown that thepIants obtained slightly more nitrogen from the extracted gardensoil than from the original soil, whilst with the arable soil theresults were reversed. The differences are, however, very slight,not only as between extracted and unextracted soils, but alsobetween the garden and arable soil. The total nitrogen removedfrom the untreated garden soil, which contained 0.315 per cent.of nitrogen, amounted t o 1.07 gram, whilst the extracted arablesoil, containing 0.109 per cent. of nitrogen, parted with just thesame amount. Expressed as percentages of the amount of nitrogenactually present, the four crops assimilated about 7 per cent.ofthe nitrogen (soluble and insoluble) present in the garden soil andabout 20 per cent. of the insoluble nitrogen remaining in theextracted arable soil.It was further shown that the extraction of humus, which ofcourse involves an initial treatment with dilute acid as well as1 7 \V. 13. Hottouilry, Bull. d g r i c . IitkZZ. Platit Diacctaea, 1'315, 6, 1162;18 W. \Velr, J . ilg/ic. Sci., 1915, 7, 246.B i o c / i e / ~ . J . , 1915, 9, 260AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 219extraction with alkali, produced changes which are observed inpartial sterilisation with antiseptics-a fall in the number ofbacteria followed by a great increase, increased ammonia produc-tion, and diminished nitrification.Unlees the treatment of the extracted soils ictroduced somelasting stimulating effect to compensate for the loss of directlyavailable nitrogen, the results seem to indicate that insolublehumus is broken down a good deal more rapidly than has beensupposed.It would be desirable to prolong an experiment of thiskind, and to ascertain by subsequent extractions, a t suitableintervals, the rate at which soluble humus is produced. Sinceabout 40 per cent. of the total soil nitrogen is extracted by alkali,and about 20 per cent. of the rest can be removed by four crops,it should not take long to reach the point when ntirogen hungerbecomes evident.Tetracarbonimide has been obtained from soils in Florida,Virginia, Naryland, and Washington, 'D.C., in quantities sufficientf o r purification and identification, and i t is estimated that ahectare of soil to a depth of 30 cm.contains about 8 kilos. of thissubstance.19 As uric acid is not known to occur in soils or plants,i t seems likely that the tetracarbonimide found in soils is derivedfrom purine bases. Xanthine, hypoxanthine, and adenine all occurin soils, and guanine has been found in a heated soil.Partial Sterilisation of Soils.Further experiments on the partial sterilisation of soils showedthat with any particular antiseptic no increase in the amountemployed over the amount required to produce the usual partialsterilisation had any further effect.20 Paraffin hydrocarbons giverise to a depression in the number of bacteria and a decidedincrease in the ammonia, without, however, suppressing the nitri-fying organisms and the protozoa.Results similar t o these,although less marked, are obtained by merely air-drying the soilsin thin layers f o r twenty-four hours. Substances which are notcompletely removable from the soil leave a lasting effect on theflora. With lower concentrations two or three species of bacteria,according t o the substance employed, multiplied temporarily to anenormous extent, without, however, increasing ammonia or nitriteproduction.Whilst volatile aiitiseptics are undoubtedly effective in increasing the productiveness of a soil under pot-culture conditions, they1 9 E. C. Shorey and E.H. Wdtors, J . 85vic. Rcsearcli, 1014, 3, 175; d., i,1092.20 \V. Buddin, J. Bgric. Sci., 1914, 6, 452; A., i, 112220 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.are unsuitable for application on a large scale. For that purposea solid substance is desirable.Some experiments with frozen soils showed a decided increasein the number of bacteria.21 The results are difficult to accountfor, but i t is suggested t h a t if the change is due t o the same causeswhich give rise to the increase in soils partly st.erilised by heator antiseptics, a cold winter may be expected to be more beneficialt o crops than a warm one.Further results of an investigation on the employment oflime22 for the partial sterilisation of soils, to which reference wasmade last year, showed t h a t whilst the amount of lime required bydifferent soils may vary considerably, and that both a deficiencyand an excess are t o be avoided, it is not a difficult matter toascertain by laboratory experiments the approximate amount oflime which should be applied t o obtain the desired results.For thispurpose samples of the soil (100 grams) are treated with calciumoxide in quantities of 0.1 to 1 gram and 50 C.C. of water, shakena t intervals for a few hours, filtered, and washed with a further200 C.C. of water. The amount of lime which gives a filtrate, thewhole of which requires 5-10 C.C. of #/lo-acid f o r neutralisation,may be taken as the limit t o which lime must be applied. Theamounts of lime required t o produce an alkaline reaction agreeclosely with the amounts which produce the characteristic partialsterilisation effects as indicated by the destruction of protozoa andthe inhibition of nitrifying organisms.The results of pot experi-ments showed t h a t the amounts of lime as indicated by the abovemethod coincide with the amounts required for the maximumproduction of dry matter and also the maximum production of drymatter in the first four crops, Larger amounts of lime increasedthe production of ammonia and nitrates, but not the crop.The results of experiments on the relation of protozoa to bacteriaare conflicting. On the one hand, it has been shown t h a t additionof protozoa to an ammonifying solution resulted in a decidedlimiting effect on the number of bacteria, whilst some evidence, notabsolutely conclusive, was obtained t h a t t h e protozoa had aninhibiting effect on the production of ammonia.I n soil experi-ments it was found t h a t by inoculating sterilised soil with protozoaand bacteria, and with bacteria alone, there was a marked reductionin the bacterial numbers when protozoa were present.22aOther experiments have indicated that the presence of 10,000protozoa per gram of soil failed to reduce the bacterial content11 H. J. Coiiii, A'ew YorL Agiic. EXJJ~T. Ktcct. II'echti. Bull., 35.23 H. B. Hutchinson mid I(. 1\IoLennaii, loc. c i t .~ f i A. Cunningham, J . Bgric. Sci., 1015, 7, 49AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 221of a soil t o the level of a soil containing no protozoa kept underconditioiis Favourable t o the trophic existence of aiimliz andflagellates." It was iiot found possible by inoculatioii withprotozoa to restore to soils which had been partly sherilised thefactor which limits bacterial activity, and from these results theconclusion is drawn t h a t the limiting factor is not of protozoanorigin.In reference t o the last results it has been pointed out t h a tby inoculating partly sterilised soils with hay infusion the normalsoil fauna is not added, and t h a t the addition of protozoa to apartly sterilised soil, somewhat changed in the process, does notmake i t correspond exactly with the original untreated soil.24Iii accordance with previous observations, it has again beenshown t h a t by heating soils tlie solubility of some constituents isiucreased.25 Extracts of heated soils showed an increasing depthof colour with each rise in temperature and an increase in conduc-tivity; whilst in the case of soils heated to higher temperaturesthe extracts showed an increased depression of freezing point, abouthalf of which is due t o electrolytes.Another effect of heating wasa change in tlie texture of the soil, resulting in an increased powerof retaining water.Soil Bacteriology.The examination of a large number of soils showed t h a t Aaoto-h n c t CT is less widely distributed than is generally supposed, andt h a t it is not always found in soils containing sufficient amountsof basic substances, although the basic character of the soil is themain factor on which its presence de~ends.~B It occurs verycommonly in soils which contain sufficient calcium carbonate t oeffervesce when acid is added, b u t is rarely found in neutral soils,and scarcely ever i n acid soils, and its disappearance from a soilis usually caused by the absence of basic substances, especiallycalcium and magnesium carbonates, and not by the presence of atoxic substance.As regards phosphoric acid, indications wereobtained t h a t when a mannitol solution free from phosphatesproduces a vigorous growth of Azotobacter after inoculating witha soil, it may be assumed that the soil is not deficient in phosphoricacid.I n the soils of Danish forests Azotobacter was found in only twoout of sixty-four localities, and both the soils which gave positive23 T.Goodey, Proc. Roy. SOC., 1915, [B], 88, 437.24 E. J. Russell, ibid., [B], 89, 76.25 A. Wilson, Sci. PTOC. Roy. Dublin SOC., 1915, 14, 513; A . , i, 1090.H. R. Christensen, Centr. Bakt. Par., 1915, ii, 43, 1; A . , i, 196222 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.results were from beech woods and contained carbonates.27 Theorganism, wliicli was not the usual form, but probably A . Nrzjer-orckii or .1. mtwu//L, was also found in a black peat which effer-vesced with acid. The forest soils rarely contained enoughcarbonate t o effervesce, but were frequently neutral o r slightlyalkaline.It is considered probable t h a t the absence of Azotobacter maybe due partly to the low temperature, a deficiency of calciumcarbonate, and an excessive amount of humus.The nitrogen supplyof the soils would seem to be obtained by some other organism.The results of weekly inoculation experiments with Pusa soilsshowed t h a t the fixation of nitrogen is most active from June toSeptember, which is the rainy season with fairly high temperature;whilst the lowest results were obtained from October t o January,being coincident with the drying of the soil and lower tempera-tnres.28As regards the amounts of water most favourable to nitrogen-fixation, it has been found i n experiments with a light sandy soilkept a t a temperature of 28-30° t h a t the greatest amounts ofnitrogen were fixed when the soil contained 20-24 per cent.ofwater. The former amount corresponds with the optimum asindicated by physical tests.29Experiments have been made on the fixation of nitrogen inculture solutions by Azotobacter in the presence of various organiccompounds, both non-nitrogenous and nitrogenous.ciO On the whole,the substances employed had not much effect, and the action wasgenerally different from what has been obswved with plants, Ofthe different non-nitrogenous compounds employed, quinol andsalicylaldehyde were found t o be the most toxic, whilst esculin,quinic acid, and borneol acted as stimulants. As regards nitrogencompounds, nicotine, picoline, guanidine carbonate, and scatole allshowed the toxic properties usually ascribed to them; caffeineseemed t o stimulate growth.Several compounds, especially thesimpler ones, such as carbamide, glycine, formamide, and allantoin,had a depresing effect on nitrogen-fixation, possibly owing t o thesubstances being assimilated in preference to elementary nitrogen.In order to ascertain to what extent Azotobacter is able t o27 F. Weis and C. H. Bornebusch, Bull. Agric. Intell. Plant Diseases, 1915,28 J. H. Walton, Mem. Dept. Agric. India, Bact. Ser., 1915, 1, 97; A., i,28 C. B. Lipman and L. T. Sharp, B d l . Agric. Intell. Plant Diseases, 1915,80 H. S. Reed and B. Williams, Centr. Bakt. PUT., 1915, ii, 43, 166; A , , i,They contained, however, calcium in other forms.6, 546; Det forstl. Pors$gsvaese in Danmark, 4, 319.1039.6, 1167; Bot. am., 1915,59, 402.196AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.223ntiliae humus and the non-nitrogenous compounds which occur insoils, experimentb have been made on the behaviour of the organ-ism towards humates ant1 a number of sugars, alcohols, acids, a i dother ~ u b s t a n c e s . ~ ~As regards humates, it was found that the potassium and calciumsalts are not utilised in absence of additional combined nitrogen, andt h a t whilst there was growth when ammonium liumate was supplied,no nitrogen was fixed. With polysaccharides, especially gum traga-canth and inulin, with arabinose, xylose, lmulose, and some othersugars, nitrogen fixation mas vigorous; with lactose less nitrogenwas fixed. Of the different alcohols employed, ethylene glycol gavethe highest results, and then mannitol ; whilst with methyl, ethyl,and propyl alcohols the amounts of nitrogen fixed per gram wererespectively 2.1, 4’0, and 9.2 milligrams. Good results wereobtained with some of the acids (as calcium salts), especially lacticacid; succinio acid came next, whilst with maleic and glycollicacids oi21y small amounts of nitrogen were fixed, and with mecoiiicacid none a t all.Fatty acids were found to be readily utilised, theamount of nitrogen fixed riring with the increase in molecularweight from 1.47 milligrams with formic acid to 6.08 milligrams wit11butyric acid. Most of the naturally occurring glucosides, and allthe benzene derivatives employed, were found to be unsuitableas souxces of energy f o r Azotobacter.I n the case of the four fatty acids it is shown t h a t the ratios ofnitrogen fixed to the heat of combustion are almost constant, andt h a t the same holds good in the case of starch, dextrin, and gumarabic, allowing for experimental error, which is greater withthese substances than with the simpler compounds.This closerelation is not, however, general, and no regularity is observed withthe series of monohydric alcohols.Whilst the failure of potassium and calcium humates to supportthe life of Aaotobacter, if confirmed, seems rather remarkable,although practically not of much importance, since some of theproducts of the decomposition of humates would probably be avail-able, the results on the whole indicate t h a t i n normal soils suit-able food of some kind may generally be expected t o be present insufficient amounts.The absence of antagonism between calcium and magnesiumchlorides f o r B.subtilis, as an ammonifying osganism>2 has beenexplained on the assumption t h a t calcium is not essential forbacteria as i t is for chlorophyllous plants.33 It is now shown t h a tthis explanation is inadequate, since it has been found t h a t in the31 F. A Mockeridge, Biochem. J . , 1915, 9, 272; A., i, 754.32 C. B. Lipman, Bot. Gaz., 49, 41. 33 0. Loew, i b i d . , 304224 ANKUAL REPORTS ON THE PROGHESS OF CHEMISTRY.case of A i o t o b u r t f r cliroococcum calcium carbonate overcame thetoxic effect of magnesium carbonate.34I n water cultures, calciuni carbonate was found to act as astimulant towards ilzotobncter in concentrations up t o 2 per cent.,whilst magnesium carbonate is toxic in concentrations of not morethan 0.1 to 0.2 per cent.Addition of calcium carbonate to culturescontaining 0.2 per cent. of magnesium carbonate became effectivewhen the amount reached 0.75 per cent., and the maximumantagonistic effect was obtained with 1.25 per cent.I n soil cultures (a sandy soil was employed), calcium carbonatealone had no effect up t o 1.4 per cent. of the dry matter of thesoil, aiid larger amounts were toxic. Magnesium carbonate provedt o be more toxic in soil than in solutions, nitrogen fixation beingalmost completely inhibited by 0.1 per cent. With this amountof magnesium carbonate, addition of calcium carbonate has a pro-tective action, the best results being obtained when the ratioCaCO, : MgCO, was about 15 : 1.The toxic action on Azotobucter of calcium carbonate when soilscontain more than 1.5 per cent.is of considerable interest, althoughit seems likely t h a t the amounts which are toxic will vary withdifferent types of soil, and in some cases may be a good deal higherthan in the case of the sandy soil employed in these experiments.The results seem clearly t o indicate the desirability, in the case ofsoils which require calcium carbonate, of ascertaining how much isactually required, so as to avoid a large excess. If soils in whichAzotobacter may be assumed to be active do not, as time goes on,become more nitrogenous, they would, no doubt, become poorer innitrogen if the activities of the microbe are in any way checked.As the toxic effect of magnesium carbonate has been attributedto its alkalinity, i t should be mentioned t h a t the alkalinity wasfound to be favourable rather than otherwise.Certain compounds of arsenic have been found to stimulate thefixation of nitrogen by Azotobacter.35 Of the different substancesemployed, lead arsenate gave the best results, and it was also foundto be the least toxic, as much as 400 parts per million being harm-less.Paris green, which is very toxic, even when only 120 partsper million are present, failed to produce stimulation i n any con-centration. The results resemble those previously obtained innitrification experiments. The stimulation of A zotobacter byarsenic is greatest when the water-soluble arsenic amounts t o about10 parts per million.In the case of soils containing plenty of34 C. €3. Lipmon and P. S. Burgess, J. Agric. Sci., 1914, 6, 484; A., i, 72.35 J. E. Greaves and H. P. Anderson, Centr. Bakt. Par., 1914, ii, 42, 244;A . , i, 484AGRICULTURAL CHEMISTRY AND VEGETAELE PHYSIOLOGY. 225organic matter, addition of arsenic resulted in as great an increasein the amount of nitrogen assimilated as when inannitol was addedwithout arsenic.Only one type of Azotobncter was isolated which was stimulatedby arsenic. The stimulation is attributed t o the organism beingenabled t o utilise more economically its source of carbon. I n soils,the favourable effect of arsenic is considered.to be partly due tothe destruction of undesirable species. A number of soils wereemployed in these experiments, differing widely both physically andchemically.A study of the influence of phosphates and sulphates onammonification in peptone solutions, with both pure and mixedcultures, showed that potassium dihydrogen phosphate greatlyincreased the production of ammonia, especially a t the end of thefirst two days. Bone-ash had no effect, whilst calcium andpotassium sulphates slightly increased ammonifi~ation.3~ The in-creased production of ammonia in the presence of potassiumdihydrogen phosphate is not due to increased efficiency, b u t t o anenormous increase in the numbers of the bacteria.I n soils it was found t h a t potassium dihydrogen phosphatecaused a distinct gain in ammonification, and t h a t trjcalcium phos-phate also stimulated ammonification by increasing the niultiplica-tion of the bacteria.Calcium, magnesium, and potassium sulphatesalso had stimulating effects.All these compounds, especially the phosphates, increased theproduction of carbon dioxide. It would seem, therefore, t h a t apartfrom their direct manurial value, the manures act indirectly inincreasing the supply of available nitrogen, and also the supply ofavailable minerals as a result of increased amounts of carbondioxide.A new nitrite organism has been isolated from Pusa soil37 whichis stimulated by an atmosphere containing 50 per cent. of carbondioxide, whilst further amounts have a retarding effect.I n thepresence df phosphates, the organism produces nitrites froinammonium salts, asparagine, and carbamide ; when, however, phos-phates are absent, only ammonium carbonate is readily convertedinto nitrite. Calcium carbonate, which is more suitable than mag-nesium carbonate for providing a base, seems to have an inhibit-ing effect in the case of ammonium carbonate and carbamide. Theaction of the organism is inhibited by 0.4 per cent. of dextrose inOmelianski's solution, and retarded by 0.4 per cent. of asparagine.s6 E. B. Fred and E. B. Hart, Wisconsin Agric. Exper. Stut. Research Bull.,35, 1915; A . , 1916, i, 104. '' N. V. Joshi, Mem. Dept. Agric. India Bact. Ser., 1915,1,85 ; A . , 1916, i, 105.REP.-VOL. XII. 226 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Experiments with a number of soils showed t h a t their power ofdecomposing peptone varies very considerably, and depends bothon chemical conditions, in which phosphoric acid has an importantshare, as well as on biological factors.38 Application of calciumcarbonate was generally without effect, and none of the soils wasinfluenced by addition of humus.It was found that, as a rule, alow power of decomposing peptone was coincident with conditionsunfavourable t o the growth of plants.The decomposition of cellulose was not affected by inoculationalone, and depends on chemical composition, lime and phosphoricacid being important factors.The conversion of sulphides in soils into sulphates is shown tobe due mainly to bacterial action, although small amounts ofsulphide may be oxidised chemically.s’J Free sulphur is convertedinto sulphates much less readily than sodium, potassium, and calciumsulphides.The optimum amount of water in the soil for sulph*fication is 50 per cent. of the amount required for saturation.Aeration has an important influence, and i t is found that addi-tion of sand to soil in gradually increasing amounts results in acorresponding increase in sulphates until 50 per cent. is added;further addition of sand, up t o 90 per cent., gradually diminishedthe production of sulphates, owing t o deficiencies of humus andmineral nutrients. The effect of organic matter on the produc-tion of sulphates depends on the nature of the substance employed.Carbohydrates, such as sucrose, starch, and cellulose, had a depress-ing effect, and applications of very large amounts of horse and cowmanures and clover hay resulted in a considerable reduction in theamounts of sulphates produced, and, coincidently, a similar de-pression i n the growth of timothy in a duplicate series.This wasfollowed by an increased production of sulphates and also anincrease in the crop. Addition of calcium sulphate t o the soil wasfound to have a very marked stimulating effect on the conversionof sulphides and sulphur into sulphates.The sulphur compounds present in organic manures seem t o beconverted into sulphates very rapidly.I n the production of sulphates from iron sulphide in i t isstated t h a t the iron alone is first oxidised, and t h a t the sulphurthus liberated is subsequently converted into sulphate.A number of organisms have been obtained from soils and dust,etc., which have the power of utilising benzene derivatives as thes8 H.R. Christensen, Zoc. cit.sg P. E. Brown and E. H. Kellogg, Iowa Agric. Exper. Stat. Research Bull.,40 H. Kappen and E. Quensell, Landw. Versuchs-Stat., 1915,86, 1 ; A . , i, 203.18, Dec., 1914; Centr. Bakt. Par., 1915, ii, 43, 552; A . , i, 763AGRICULTUUAL CfIEMISTRY AND VEGE I'ABLE PHYSIOLOGY. 2270x11~ sources of carbon.41 Plienol and phloroglucinol, f o r instance,are oxidised €0 carbon dioxide, benzene to fatty acids and carbondioxide. Catechol is oxidised, probably to hydroxyquinol, andtoluene, xylene, and guaiacol were also decomposed.Resorcinol,pyrogallol, tannin, aniline, naphthalene, and anthracene were notdecomposed.Plant -Vutrition a7id Manures.Although it seems fairly evident that the elementary nitrogenacquired by leguminous and other plants having root-nodules mustbe fixed initially in the root-nodules, and not in the leaves as hasbeen suggested, the few experiments made in this connexion havenot been very convincing. The question has now been settled ina satisfactory manner42 by experiments with soja-beans and COW-peas which were grown in Woulfe's bottles through which a mix-ture of oxygen and carbon dioxide and air respectively werepassed; the stems and leaves of the plants were exposed t o the air.The results showed t h a t almost no nitrogen was fixed except whennitrogen had access to the roots.Some slight gains of nitrogenwere obtained i n the case of the plants grown with oxygen andcarbon dioxide which are attributed to air dissolved in the waterof the gas-holders. I n an ordinary atmosphere the plants producedlarge amounts of roots and root-nodules, whilst without nitrogenthe development of roots and root-nodules was very restricted.Incidentally, the results indicate the importance of aerationwhen leguminous crops are grown.Bacteria belonging t o the Bacillus radzcacola group have beenfound i n the root-nodules of Ceanothus americanus growing wildin North Ameri~a.~3 The microbes obtained both from C.trmericnnus and C. welutiiLiu were found to fix nitrogen i n amountssimilar t o those obtained with the bacteria from Alnus andElzagnus nodules.I n the root-nodules of the Cycadacea, both Baczllus radicicolaand Azotobacter have been found.44It has been found in water-culture experiments with rye andbarley that, within fairly wide limits, the concentration of thenutrient solution is not very important provided t h a t the solutioni s frequently ~hanged.~5 When the solution is not changed, thereis a marked depression in the rate of growth, probably due t o the41 R.Wagner, BLed. Zentr., 1915, 44, 212; A . , i, 628.42 A. L. Whiting, Univ. Illanozs Agric. Exper. Stat. Buli., 179, 1915.43 W. B. Bottomley, Ann. Bot., 1915, 29, 605.44 E. R. Spratt, ibzd , G19.45 W. Stdes, Bull. Agrzc.Intel2. Plant Diseases, 1915, 6, 563.1 228 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.absorption of the different ions a t different rates, resulting after atime in a change' in the relative proportions of the different sub-stances.The weakest solution employed in these experiments containedabout the same amounts of potassium and phosphoric acid as werecalculated by Cameron to be present in the soil solution, so that itmay be considered to be probable t h a t the concentration of the soilsolution, although low, is sufficient to produce healthy, if not verylarge, plants.On the assumption t h a t the tricalcium phosphate of rock phos-phates is rendered available by the action of carbon dioxide andwater, dicalcium phosphate and calcium hydrogen carbonate beingformed, the amount of soluble phosphate obtained will depend onthe amount of calcium hydrogen carbonate which is removed bythe plant or i n other ways.46 From this it seems to follow thatplants which contain relatively large amounts of calcium have arelatively high feeding power for the phosphoric acid of crudephosphates, and vice vers8.Peas, beans, clover, lucerne, andcruciferous plants contain relatively high amounts of calcium,whilst in maize, oats, rye, wheat, and millet the amounts are rela-.tively low. According to this theory, i t should be possible to ascer-tain by analyses of the ash of a plant whether a soluble phosphaticmanure is required. Other factors have, of course, t o be con-sidered. The employment of ammonium salts, f o r instance, willincrease the solubility of the rock phosphate by assisting in theremoval of the calcium hydrogen carbonate.I n its general application to insoluble plant foods, the theorywould be t h a t the assimilating power of a plant for insoluble sub-stances depends, first, on the solubility of the substance in waterand carbon dioxide, and next on the removal by the plant of allthe products of the reaction in the proper proportion, so t h a t thereaction can continue indefinitely.The injurious effect of vanillin on plants has been shown to varywith different soils.47 I n experiments with clover, an applicationof 100 parts of vanillin per million, which was gradually raised to300 parts per million, resulted in a reduction of 53 per cent.inthe yield ; the plants, however, remained healthy in appearance.I n the case of wheat, i t was found t h a t vanillin has injuriouseffects in an infertile sand and in an unproductive sandy loam,whilst the plants grown in a productive loam were not injured byas much as 500 parts per million, the vanillin no doubt beingoxidised. I n plot experiments, applications of vanillin a t the46 E. Truog, Science, 1915, 41, 616.47 J. J. Skinner, U.S. Dept Agric. BuZZ, 164, 1916; A , 1916, i, 111AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 229rate of 320 kilos. per hectare t o cow-peas, peas, and beans resultedin stunted growth, although the plants slowly matured and wereharvested.Under favourable conditions, vanillin may remain a consider-able time in the soil.I n the case of a heavy, silty clay loam, forinstance, injurious effects were observed six months after vanillinhad been applied.I n another series of experiments in which the effects of organicsubstances on the growth of wheat i n water-cultures and i n soilwere compared,4R it was found t h a t whilst 500 parts per million wasfatal t o wheat in water-cultures, twice that amount applied to soilfailed t o have any effect. Salicylaldehyde, which varies i n itseffects on wheat according to the soil, is not toxic up t o concentra-tions of 500 per million, whilst pbenzoquinone is beneficial inconcentrations below that amount, and coumarin and dihydroxy-stearic acid are slightly injurious. In water-cultures all these sub-stances have a pronounced toxic action.An investigation of the effects of vanillin and coumarin49 onwheat in water-cultures, in sand-cultures, and in soil showed t h a tboth quartz sand and soil have ameliorating effects on the actionof vanillin, whilst coumarin has the same effects in sand as inwater-cultures; addition of a smaI1 amount of soil t o water-culturescompletely destroyed the toxic action of coumarin, b u t had noeffect in the case of vanillin.From these results the conclusion isdrawn t h a t vanillin is only toxic when present in a solution whichcompletely envelops the roots in a continuous layer. I n the caseof coumarin, the effects of additions of soil in amounts too smallfor the adsorption of the relatively large amounts of toxin isattributed to the oxidation of the coumarin.The healthy appearance of the plants which received the highestamounts of vanillin and coumarin, and the absence of inhibitingeffects on the growth of the roots, seem t o indicate t h a t the de-pressed yields of wheat were not due t o toxicity a t all, and t h a tthey may be attributed t o the general effects of soluble, non-nutrient organic matter, which may affect the micro-flora of thesoil, and t o some extent the physical conditions of the soil, byforming protective films, or it may interfere with the absorption ofcertain nutrients by plants.From this point of view vanillin andcoumarin, and presumably some other toxins, have no direct actionon plants, b u t influence growth by influencing certain soil con-ditions.The results of these experiments make it evident t h a t i t is rash48 F.W. Upson and A. R. Powell, J . I?zd. Eny. Chent.. 1915, 7, 420; A , , i, 635.( @ J. Devidson, J. Amer. SOC. Agron., 1915, 7, 146, 221230 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.t o draw conclusions from water-culture experiments as to whatmay occur in field experiments. I n view of the difficulty ofexplaining the effects of definite substances which can be takenfrom one soil and added t o another. it seems undesirable definitelyt o attribute injurious effects to toxins which have not been seenand possibly do not exist.A number of experiments have been made on the action ofradium on germination and growth of plants.50 I n the case ofpea seedlings which were subjected to the action of emanationfrom radium bromide contained in sealed tubes, a decided retard-iiig effect was observed; whilst a solution of radium bromide con-taining 0.001 inilligram had no effect.TYTTEen, however, differentplants were grown under bell jars along with radium contained inan ebonite box covered with mica, so t h a t the emanation coulddiffuse, growth was considerably accelerated. On examining theplants grown with radium, it was found that the cells of the stemswere narrow and of greater length than those of the check plants,resembling etiolated plants.I n plot experiments with a considerable number of vegetablesapplications of extracted radium ore, containing two o r three milli-grams of radium per ton, at the rate cf 28-225 kilos.per hectare,nearly always increased the yields. The quality of potatoes andtomatoes was improved.51A t Reading the experiments with radium which were com-menced last year have been continued, the number of radioactivesubstances employed being increased from three t o nine.52 Stimu-lat,ion was observed in a number of cases, the results with onionsbeing especially favourable.Pcsitive results have also been obtained with ‘‘ radioactin,” whichconsists mainly of aluminium silicate and contains a small amountof radium salt and larger amounts of thorium. Application of0.2 gram t o a kilo. of soil increased the yield of oat grain about18 per cent.63Applications of radium barium chloride solution and of solidradium barium sulphate at the rate of 0.01-1 milligram ofradium per acre failed t o produce any regular increase in theyield of maize.54It seems generally t o be recognised, although not always, thatthe employment of radium is not likely t o be remunerative.It hasso H. Agulhon and T. Robert, Ann. I n s t . Pasteur, 1915, 29, 261; A., i, 925.5l 1%. H. Rusby, Bull. Agric. Intell. Plant Diseases, 1015, 6 , 1318.62 Scottish Farmer, 1915, 23, 563.53 B. Schulze, Landw. Versuchs-Stat., 1913, 87, 1; A , , i, 926.54 C. G. Hopkins and W. H. Sechs, Science, 1915, 41, 732AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 231been estimated t h a t an acre of soil, t o a dept.h of 12.5 cm., containsabout 1 milligram of radium, and t h a t the emanation given off bythe soil is fifty t o one hundred times as much as the amount givenoff by the upper 12.5 cm.So t h a t t o double the emanation in thesoil i t would be necessary to apply about 76 milligrams per acre.The amount would, qo doubt, vary with different soils; the exam-ination of a number of soils in Minnesota showed t h a t the veryfertile soils always contained more radium and thorium emanationsthan the inferior soils.55A number of experiments have again been made on the effectsof vegetation of salts of heavy metals and other compounds notusually employed as manure. I n the case of aluminium salts itwas found that concentrations of 0.005 per cent. retarded thegrowth of maize, beans, and other plants, whilst solutions contain-ing only 0.0001 per cent..slightly increased growth.66 Other experi-ments with maize indicated t h a t aluminium je essentia1 t o growth.57Fluorine is also stated t o be essential for the development ofmaize.58 I n experiments with various other plants the action offluorides, although usually found t o increase growth and the pro-duction of seed, seemed in a few cases t o have a retarding effect.69Experiments have also been made with salts of manganese,so lead,and copper,61 and with boron and iodine.02Reference has already been made to the relatively slight effectof sulphates as compared with phosphates on the soil flora. As asulphur manure, the application of calcium sulphate to a silt loamincreased the yield of clover 23 per cent., whilst in the case ofrape and radishes the sulphate applied in addition to a completemanure increased the yields by 17 and 9 per cent.respectively.63The presence of sulphates had a marked effect on root development,especially of red clover and rape, resulting in a inore extendedfeeding area f o r the plants.Elelnentary sulphur was generally found to be injurious, evenwhen plenty of calcium carbonate was added.By means of a bacterial test it has been found t h a t plant foodaccessories are present in fresh stable manure, and that the amount55 J. C . Sanderson, Amer. J . Sci., 1915, 39, 391.56 E. Kratzmann, Bttll. Agric. Intell. Plant Diseases, 1915, 6, 403.67 P. MazB, Compt. rend., 1915, 160, 211; A , , i, 110.5 8 P.hfazb, loc. cit.59 A. Gautier, Compt. rend., 1915, 160, 194; A , , i, 111.6o G. D'Ippolito, Ann. Chim. AppZicnta, 1914, 2, 342; A., i, 52; B. Schulze,Landw. Versuchs-Stat., 1915,87, 1. A . , i, 926; G. Mason;, Staz. sper. agrar. ital.,1915,48, 822.61 J. A. Vodcker, J . Roy. Agric. SOC., 1914, 75, 306.62 P. MazP, loc. cit.63 E. B. Hart and W. E. T0ttingham.J. Agric. Research, 1915, 75, 232232 ANXUAL REPORTS ON THE PROGRESS OF CHEMISTRY.increases as the organic matter of the manure decomposes.64 Theamount even in manure two years old seems, however, t o be small ascompared with bacterised peat, since half a gram of the latter gavea better result than 10 grams of manure. Plant food accessorieswere also found in root nodules from bean plants.As regards the manurial value of bacterised peat a number ofexperiments have been made a t Woburn with barley, peas, mustard,and tomatoes.05 The beneficial effect of the peat manure was verymarked in the case of mustard, whilst the yields of barley andpeas were also increased.I n these experiments, which were madein pots, one part of bacterised peat was mixed with eight parts ofsoil, forming the top 15 cm. This would correspond with anapplication of about 100,000 kilos. per acre.Apart from these experiments there does not seein t o be verymuch evidence as to the value, or otherwise, of the peat, manure.Reference was made last year t o some experiments on the effectsof applying nitrates a t different depths. A new series of experi-ments has been made, in which ammonium sulphate was similarlyapplied t o sugar-beet on a loamy soil.@ It was found that thebest results were obtained when the manure was dug in to a depthof 10 cm., whilst very satisfactory results were also obtained onthe plots dug to 30 cm.When the manure was applied as a topdressing, or was dug in t o a depth of only 5 cm. growth was moreprolonged and there was a predominance of leaf over root.The results of estimations of nitrates in the soil at differentperiods indicated t h a t no loss of nitrate occurred under the condi-tions of the experiments.The application of manures in little heaps, with each seed, bymeans of a special drill, has been found t o result in considerablyincreased yields in grain and straw in the case of wheat manuredwith superphosphate and with vetches manured with basic slag.67Satisfactory results were also obtained with oats manured withsodium and calcium nitrates, ammonium sulphate, dried blood,potassiuiii chloride, and manganese sulphate respectively ; whilstwith potassium sulphate and especially with cyanamide the resultswere unfavourable.Experiments have been made on the production of nitrates fromsewage sludges applied to three different soils.68 The sludges con-64 W.R. Bottomley, Proc. Roy. SOC., 1915, [R], 89, 102.65 J. A. Voelcker, J. Roy. Agric. Soc., 1914, 75, 318.66 L. Nalpeaux, La Vie agric. rurale, 1915, 5, 61 ; Bull. Agric. Intell. Plant67 L. BrBtignibre, J. Cartier, and L6v&que, Ann. &cole N n t . Agrlc. Grignon,BB C. B. Lipman and P. S. Burgess, CaZifornia Agric. Ezper. Stat. Bztll., 351.Diseases, 1915, 6 , 1170.1915, 4, 1 ; Bull. Agric. Intell. PZant Diseases, 1915, 6, 1459AGRICULTURAL CHEMISTllY AND VEGETABLE PHYSIOLOGY. 233tained from 1.23 t o 2.66 per cent. of nitrogen. The results showedt h a t the amounts of nitrates produced from the different sludgesin the same soil varied considerably, and t h a t variations alsooccurred with the same sludge in different soils. That is, of course,t o be expected.As compared with other organic manures, such as dried blood,tankage, fish guano, and cottonseed meal, it was found t h a t thenitrogen of the sewage sludge was greatly superior to t h a t of theother manures, being much more readily convested into nitrates.The results of a number of manurial experiments with sewagesludge made in different parts of England69 are not so encouragingas those just referred to. The general results seem to indicate that,under the conditions of the experiments, the nitrogen of the sludgeonly slowly becomes available; too slowly, in fact, f o r such cropsas potatoes and roots. So that the manure would seem to be bestsuited to certain pastures and meadows, on which, however, theapplications would have t o be more limited than on arable soil.Further experiments are evidently needed.A new method has been devised for the preservation of liquidmanure in the pit, which is based on the existence of lactic acidbacteria having the power of preserving fresh urine.70 Ten percent. of a broth made froin sugar-beet is mixed with 90 per cent.of water inoculated with Bacillus ciicumeris ferrneiztati, which isemployed f o r preserving potatoes, and thrown into the manurepit. Instead of sugar-beet, 5 per cent. of molasses or 10 per cent.of a mixture of sweet potatoes can be employed.The amount of sugar required to preserve 100,000 kilos. ofliquid manure is stated t o be 500 kilos., corresponding with 3,100kilos of sugar-beet. The bottom and walls of the p i t should bemade water-tight with tar, and it is desirable t o add a smallamount of oil to exclude air.N. H. J. MILLER.6Q J . Board Agric., 1915, 22, 235.'O Schmoeger, Bull. -4qiic. Intell. Plant Diseases, 1916, 6 , 1308

ISSN:0365-6217    

DOI:10.1039/AR9151200210

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

BIINERALOGICAL CHEMISTRY.THE present Report is similar in its scope to last year’s account,and is divided fairly equally between the three principal topics :X-ray work, experimental mineralogy, and chemical crystallo-graphy. Whilst recognising to the full t h a t such a selection isinvidious and possibly unsatisfactory, the writer must point outt h a t a selection has, perfosce, now t o be made in view of the recentfundamental extension of the old, familiar lines of investigation.The principal deficiency of this and the two previous Reportsundoubtedly lies on the side of systematic mineralogy; it is t h e r efore fortunate t h a t this want of completeness is fully compensatedby the recent appearance of the third Appendix to Dana’s ‘ I Systemof Mineralogy,” dealing with the years 1909-1915.X-Ray 1l.l ethods of Exploring Crystal Structure.”This subject is becoming so important that we may with advan-tage commence with an epitome of the salient features of thegeneral advance; these are :X-Rays and Crystal Structure,”by 1%’.H. and W. L. Bragg, whose brilliant discoveries have beenrecently recognised by the award of a Nobel Prize. The work isnot only welcome as providing a clear and fascinating resume ofwhat has already been briefly noted in these Reports, but also* A very full and complete bibliography of papers relating to X-rays sincethe “Laue-year” 1912 is included in a booklet by I. Malu-er (“Unter-suchungen uber die Hochfrequenzspektra der Elcmente ” (Lund, 1915), whohas extended some of Jloseley’s investigations (compare Ann.Repcrt, 1914,277). It will be remembered that onc of the many fundamental, chemicalconsequences of ilIoseley’s work is that the atomic numbers of cobalt andnickel are in the reverse order of that presented by the atomic weights. Onthe other hand, it is now found by Malwer that in the case of iodine andtellurium the atomic numbers do follow the order of atomic weights, althoughthe latter are just as much a t variance with the periodic classification ; thewave-lengths of a series of X-rays emitted by iodine are all greater than thecorresponding wave-lengths emitted by tellurium.234(1) The appearance of the booMINERALOGICAL CHEMISTRY. 235because i t contains a considerable amount of matter not hithertopublished.(2) A marked.advaiice i n the theoretical interpretation of therelative intensities of reflection of X-rays a t various structuralplanes.T!ie interpretation has now assumed a quantitative form,involving the atomic masses of the diffracting centres.(3) The independent elucidation of the structure of the spinelgroup by different methods. Nishikawa (of Tokyo) employed theapparently cumbersome Laue method, involving a study of X-radio-grams, whilst W. H. Bragg’s analysis was founded on the resultsobtained by the X-ray spectrometer. The results were identical.Although, of course, the two methods really depend on the samefundamental behaviour of crystal structure when confronted withX-rays, there can be little doubt t h a t the dual achievement shouldreassure a general reader, who might otherwise be disposed t owonder whether the rapidity of recent progress may not eventuallyprove to have been a t the cost of permanence.(4) The measurement by F.Canacl of a crystal of sucrose by theX-ray spectrometer instead of the goniometer ! The mean resultfrom various measurements can be put in the form a: b : c =1.260 : 1 :0.879; p= 103O30’. The accepted values derived fromthe goniometer are a : b : c = 1.259 : 1 : 0.878 ; fi = 103O30’. Suchmethods have obviously a great future.Any exploration of a particular crystal structure, when carriedout t o t h a t degree of intimacy we have learnt to expect from theresearches of W. H. and W. L. Bragg, involves certain problemswhich (at any rate, in the relatively simple cases so far examined)may be held t o be distinct and two in number; first, we have whatmay be termed the discovery of the grosser aspect of crystal archi-tecture, namely, the discrimination of the Bravais space latticeon which the [‘ structural units ” are disposed ; secondly, the probingof the much finer details, namely, the dissection of this unit, bothwith respect to its mass (“molecular weight”) and to the relativearrangement of its constituent atoms.An infinitely extended Bravais space lattice is merely the regularspacial multiplication of a parallelopipedal cell.I n crystallographyits description is generally given in the form of the ratios a : b : cof its three edge lengths (and the angles a, P, and y).On thoother hand, the spectrometric determination of the various angles, 8,a t which any structural plane intensely reflects X-rays, leads imme-diately t o a knowledge of the absolute distance, d , between succeg.sive layers of units-for in the fundamental equation = 2d sin 0the term h is now known i n absolute units, and the term n, express-Compt. rend., 1914,159, 405.I* 236 ANNUAL REPORTS ON TIIE PROGRESS OF CHEMISTRY.ing the order of the reflection (whether first, second, third, orfourth), can generally be determined cursively ; if any mistakes weremade in I I the error would be detected when other structural planesare put to the test of experiment. It will be obvious t h a t thedetermination of the grating-distances, d,, d,, d,, f o r three non-tautozonal structural planes of known inclinations, are sufficient todetermine the skeleton of the crystal.I n certain complicated cases,amongst which may be enumerated the aragonite group, ammoniumchloride, sodium chlorate, hematite, corundum, quartz, and sulphur,the investigation has not progressed beyond this preliminary stage.Now from the general properties of isomarphous series it can beinferred that the relative distances apart of corresponding struc-tural planes should be substantially in the ratios of the cube rootsof the molecular volumes; this expectation has been fully realisedby the Braggs in the only cases so far compared, namely, the groupsodium chloride, potassium chloride, and bromide, and the membersof the calcite group, including sodium nitrate.The nest step is the deduction of the mass associated with thestructural unit.The principle employed is best illustrated in termsof a rectangular cell, since its volume assumes the simple formd,d,d,, say, D. Then the mass associated with the cell is Dp, wherep is the density of the crystal. Let ;z: be the required fraction ofthe molecular weight, 111 the molecular weight, and m the mass ofan atom of hydrogen. A little consideration will show thatDp = z(Mlz), whence IC may be evaluated. I n the case of ammoniumchloride 5 is found t o be unity, whilst in potassium chloride 2 hasthe value 0.5. This demonstrates t h a t the two substances havefundamentally different structures, a conclusion which was previ-ously deduced by another method.2I n order to solve successfully the riddle of the atomic arrange-ment account must be taken of the various reflection-intensities.The mean values derived from a considerable number of crystallinesubstances point t o a regular diminution of intensities accordingt o the inverse square law, indicated for the first four orders by theratios 100:29:7:3.* Now this “normal” fall of intensity isbelied by certain structural planes.The abnormalities have receiveda satisfactory explanation; they are supposed t o be due t o aninequality of spacing between successive planes (as, for example, inthe octahedral planes of diamond) or t o a difference in atomic2 T. V. Barker, Min. Mug., 1907, 14, 235; A . , 1907, ii, 240.*The reasons for this diminution are somewhat obscure. W.H. Braggis disposed t o interpret the falling off as due t o an inequality in the distributionof the scattering centres (electrons 1 ) throughout the mass of the atom(Phi2 Trans., 1915, [ A ] , 215, 266)MINERALOGICAL CHEMISTRY. 237composition of these planes (as, f o r example, in the octahedralplanes of sodium chloride) or to both factors combined. It mustbe noted t h a t the effect of the first factor is purely a matter ofgeometrical optics; on the other hand, the quantitative treatmentof the second factor requires a n assumption or hypothesis.The assumption is, t h a t the reflective power of an atom is afunction of its mass. When first made it was in harmony withBarkla’s classical work on X-rays? and its initial employed in theFIG. 1.A e Breconstruction of potassium chloride and bromide * and of fluorspartheref ore carried a considerable degree of conviction.Furthersupport is forthcoming from the recent work on the calcite group.The atomic arrangeiiient of the calcite group is indicated byFig. 1. The upper portion, A , gives a general idea of the positionof the calcium and carbon atoms. E is the point of emergence ofthe principal axis; the three faces of the rhomb represent theCompare G. W. C. Kaye, ‘‘ X-rays ” (1914).* It may be pointed out that an investigation of rubidium chloridebromide, and iodide should furnish results of much greater weight than can beobtained from any group as yet examined, inasmuch as the atomic weightof bromine is not only almost identical with that of rubidium, but also liesbetween the atomic weights of chlorine and iodine (also note the greatsimplicity of the compounds).The series involves, in short, a doubleexperimentum crucis238 ANNtJAL REPORTS ON THE PROGRESS OF CHEMISTRY.cleavage planes. The lower portion, B, represents successive hori-zontal layers of A , and also includes oxygen atoms. It must benoted t h a t theee successive strata have the alternate composition Ca(at. wt. 40) and CO, (total wt. 60). The mass-difference of succes-sive layers is therefore 20. The same structure holds for the sub-stances isoniorphous with calcite, the full group being NaNO,(mass-diff. 37), (Ca,Mg)CO, (28)) CaCO, (20), MnCO, (5), andFeCO, (4).Now the fundamental assumption demands t h a t thefirst order of intensity of reflection from the basal plane shouldgradually fall with the mass-difference of successive layers, andvanish altogether when the two layers hsve equal masses. Fig. 2indicates how closely this expectation is realised ; the intensitiesyielded by manganese and iron carbonate were too small to beregistered by the spectrometer.Further work on calcite4 and other crystals has suggested thatthe amplitude of the wave reflected by an atom is proportional t oits mass. Now the square of the amplitude represents the intensityFIG, 2.M a s s - d i f f . 37i i NaNO, (Ca,Mg)CO, CaCO, BlnCO, FeCO,(energy) of the reflection; the intensity of reflection, then, a t anystructural plane is given by the square of the mass represented bythe chemical composition, for example, 402 and 602 f o r the succes-sive basal strata of calcite.A general formula has been derived5which enables the calculation of the theoretical intensities of thefirst, second, third, and fourth order reflections a t any structuralplane of an assemblage or reconstruction under examination. Theapplicatioh of this formula t o the elucidation of the crystal struc-tures of calcite, sodium chloride, zinc blende, iron pyrites, andmagnetite has been attended with great success. I n the case ofcalcite, for example, the ratio rc:d of Fig. 1 ( B ) , expressing therelative positions of the oxygen and carbon atoms, has now a definitevalue lying between 0.25 and 0'27, instead of the previouslysuggested approximation 0.30.Sp'izel Group.-This well-known group of minerals, of whichmagnetite, Fe,04, and ruby-spinel, MgA1,04, are prominent mem-W.H. Bragg, Phil. Trans., 1915, [ A ] , 215, 266.W. H. and W. L. Bragg, '' X-rays and Crystal Structure," 121MINERALOGICAL CHEMISTRY. 239bers, has the general formula R”R,”’O,. For the present kind ofwork i t is necessary to emphasiae (as Nishikawac points out) t h a twhilst oxygen atoms play a relatively insignificant r81e in the X-raybehaviour of magnetite, thoy acquire some importance in spinelowing t o the comparatively lower atomic weight of magnesium andaluminium. The method adopted by Nishikawa was t o analysethe radiograms obtained by symmetrical and unsymmetrical expo-Fro.3.0 R“0 R-o o6 Csures of the crystals, and compare them with the diamond radio-grams and structure. By an extremely ingenious train of reason-ing a structure was finally obtained which satisfies all requirements.Fig. 3 is a direct reproduction of Nishikawa’s diagram. The upperportion ( A ) is Braggs’ diamond structure.” I n the spinel group thecarbon atoms are replaced by R” atoms. The positions of theS. Nishikawa, Tokyo Szigaku-Buturigakkwai Kizi, 1915, [ii], 8, 199.* A comparison of A with Fig. 3 of last year’s Report will betray anunessential difference in the respect that a different group of eight cells wasselected. This selection was made advisedly, because it led to a cleardiagrammatic appreciation of the chief character of the diamond structure,namely, the tetrahedral environment of every carbon atom240 AXNUAT; REPORTS ON THE PROGRESS OF CHEMISTRY.oxygen atoms are shown in the lower portions, i? and C‘; thearrangement is seen to be tetrahedral about the centres of bothcells.On the other hand, the R”’ atoms, being half as numerousas the oxygen atoms, are restricted t o bhat kind of cell, C, thecentres of which are vacant. The whole assemblage possesses tetra-gonal screw axes and glide planes of symmetry, and belongs t o theclass Oh7 of schGnflies.7The above arrangement is typical of the spinel group as a whole,The individual members differ from each other (1) in the absolutemagnitude of the cells, and (2) in the relative positions of the El”and 0 atoms on the cell diagonals.Consider the diagonal CO ofFig. 3 (C); f o r Epinel Nishikawa deduces the distance of the oxygenatom from G to be 0.36 times the corresponding distance of thealuminium atom, whereas in magnetite the corresponding ratio issomething between 0.33 and 0‘35. This appears t o be the firstexperimental indication t h a t literally isomorphous crystals (that is,those exhibiting exactly equal angles) possess individual internalcharacteristics.The method adopted by W. H. B r a g * was t o analyse thevarious reflections given by the (loo), (110), and (111) planes ofmagnetite. This immediately suggested a structure of the diamondtype, the carbon atoms of the latter being replaced by Fe,O, mole-cules.Considerations of symmetry, the high value of the atomicweight of iron as compared with t h a t of oxygen, and, finally, thecalculation of the theoretical intensities, led t o the structure inde-pendently deduced by Nishikawa. Spinel itself is a t present underinvestigation.Lcczte X-Rnclio6/ru?,is.-Friedel’s theoretical deduction, t h a t thesymmetry of a radiogram should be identical with the crystalsymmetry t o which has been added a centre of symmetry, hasderived extensive support from the comprehensive investigationsof Haga and Jaeger.9 The earlier results of one of these workers,whilst confirming the truth of the Friedel theorem for crystalsbelonging t o the isotropic and uniaxial groups, seemed t o disclosea want of agreement in the case of biaxial crystals.Thus the planes(100) and (010) of cordierite, (010) and (100) of sodium ammoniumd-tartrate, and (010) of hambergite gave radiograms, characterisedby a single plane of symmetry, whereas two mutually perpendicularplanes are t o be expected from the rhombic symmetry of thecrystals, Later and more comprehensive researches have to some7 A. Schonflies, ‘‘ Krystallsysteme und Krystallstruktur ” (1S91), 545.* W. H. Bragg, Phil. Mag., 1915, [vi], 30, 305.F. M. Jaeger, Proc. K . Akad. TVetensch. Amsterduni, 1915, 17, 1204;H. Haga and F. 11. Jaeger, ibid., 430; 1915, 18, 542, 559MINERALOGICAL CHEMISTRY. 24 1extent explained such anomalies ; thus the identical hambergitesection previously employed was found to give a normal distributionof spots in certain of its parts and abnormal in other parts.Theauthors conclude that the unsymmetrical results are referable to alack of perfect homogeneity [probably the same heterogeneity as hasbeen observed by the Braggs i n all crystals of rock salt as comparedwith crystals of calcite]. The heterogeneity is too delicate to bedetected by ordinary optical methods; it must be remembered,however, that the shorter wave-length of X-rays renders them nmuch finer structural probe. The following exposures are alwaysabnormal: (100) and (010) of cordierite, (100) and (010) of hemi-morphite, (010) of zinc sulphate, ZnS0,,7H20. The remainingpinacoidal exposures of all the rhombic substances and the wholeof the exposures obtained with isotropic and uniaxial substances(including basal plane, first and second order prisms), are inagreement with, and substantiate the truth of, the Friedel theorem.Some idea of the indefatigable character of the author’s work maybe obtained from the following enumeration of the substancesinvestigated, which, i t will be observed, represent the majority ofthe crystal classes concerned :C‘rtb ic.-d- and I-Sodium chlorate ; ammonium-iron, and potass-ium-chromilim alums.T~tmgoi~nl.-d- and 7-Triethylenediaminecobaltic bromide.Hexccgo~~n7-rhoiriboherlml.-Beryl, apatite, ethyl sulphates of therare earths; nepheline ; calcite ; dolomite, phenakite ; tourmaline ;quartz, cinnabar.Bhomhrc.-Aragonite (pseudo-hexagonal), topaz, anhydrite, cor-dierite, hambergite ; hemimorphite, struvite ; sodium ammoniumd-tartrate, I-asparagine, zinc sulphate (d- or I- not specified, a).Another important observation of Jaeger’s is that the mineralbenitoite, previously supposed by others to exemplify one of thehitherto missing classes of trigonal symmetry, is really opticallybiaxial; moreover, a “basal” exposure proves the mineral to bemerely pseudo-trigonal.The papers are illustrated with a beautifulseries of photographic reproductions.The appearance of the first instalment of a valuable comparisonbetween the results of X-ray work and the theory of the Fedorov-Schonflies generalised point systems may be put on record.10The recent advances in our knowledge of crystal structure due toX-ray work has attracted the notice of several mathematical physi-cists.Attention may be drawn in this connexion to a suiek offour papers by Crehore,ll who has derived the equations f o r thelo A. Schonflies, Zeztsch. Kryst. Min., 1915, 54, 546.l1 A. C. Crehore, Phil. N a g . , 1913, [vi], 26, 25; 1915, 29, 750; 30, 257,613; A . , ii, 92242 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.mechanical forces between atoms and also indicated methods ofconstructing theoretical molecules and crystals having the proper-ties actually observed. These theoretical investigations alreadyembrace crystals of sodium chloride and diamond, and chemicalmolecules of hydrogen and the hydrocarbons. The last paper inparticular may be recommended to the reader as worthy of perusal,since it contains a description, with diagrams, of mechanically stablemolecules of important aliphatic and aromatic hydrocarbons.Thework may be regarded as the first serious attempt t o lay down astereochsmioal theory of precision of the chemist’s molecule.Crehore concludes that the essential difference between crystal struc-ture and molecular structure is that atoms in the former, undercertain mutual restrictions, may revolve about non-paraIlel axes,whilst in the latter all atomic rotations are necessarily parallel.GcizeTal Co7zclztsiotis.-~umerous researches have proved t h a t thequality and quantity of the characteristic X-rays emitted by anelement are independent of its state. of chemical combination andvalency. Thus it has been shown t h a t the absorption-coefficients ofthe rays emitted by the following iron compounds are identical:ferrous sulphate, ferric oxide, magnetite, and ammonium ferro-cyanide.12 A little later we had the more quantitative proof thatthe amount of X-rays emitted by a given weight of tin is unchangedafter the metal has been converted into the oxide.13 Finally, it wasshown by Chapman14 t h a t the characteristic rays of bromine andiodine are emitted by vapours of ethyl bromide and methyl iodiderespectively.The scattering of X-rays, then, is a purely atomiceffect, and i t therefore follows t h a t the recent explorations of crystalstructure, whilst leading t o a knowledge of the mean positions ofthe various atoms, cannot from the nature of the case throw anydirect light on such purely chemical questions as the existence o rnon-existence of molecules in the crystalline condition.Thermal Studies of MiiLerals.The extremely valuable work published by the American Geo-physical school demonstrates how important it is t h a t increasedfacilities should be offered t o such workers as have already shown areal aptitude f o r research. The work t o be reviewed is so extensivet h a t the writer finds i t a matt.er of some difficulty to project itsmain outlines in true perspective. An idea of its volume mayperhaps be gauged from the statement t h a t Rankin and Wright’scontribution occupies some seventy pages of tabularly arranged factsl2 J.L. Glasson, Proc. Camb. Phil. SOC., 1910,15, 437; A ., 1910, ii, 674.l 3 J. C. Chapman and E. D. Guest, (bid., 1911, 16, 136; A . , 1911, ii, 068.14 J. C. Chapman, PhiZ. Mag., 1911, [vi], 21, 446; A . , 1911, ii, 357MINERALOGICAL CHEMISTRY. 243and closely reasoned arguments, embodying the results of 1000experiments and 7000 heat treatments and microscopic examina-tions. Were it not for the fact t h a t a diagram can often conveymuch more t o the understanding than a corresponding amount ofdescriptive Drint, i t would be simply impossible to do justice t osuch comprehensive researches. For a description of the methodsemployed the reader is referred t o last year’s Report (pp. 252-255).Ternary System, Ca0-A1203-Si0,.15-It may be stated a t oncet h a t the fourteen substances t o be dealt with do not form “ solidsolutions” to any extent; this feature materially simplifies theproblem. Of the three components the melting points of lime andalumina lie a t 2570O and 2050O respectively.16 Cristobalite, thehigh temperature modification of silica, melts a t 1625O o r above.The main features of the three binary systems are as follows: Thesystem alumina-silica is quite simple, f o r the only compound issillimanite, A1,Si05 ; its eutectic temperatures with alumina andsilica are 1810O and 1610O respectively.It will presently becomeobvious that the temperature-concentration diagram is presentedby the right elevation of the model of Fig. 5. The system lime-alumina is more complicated, since four distinct compounds occur,namely, Ca.,AI,O,, Ca5AlsO14, CaA41,0,, and C3All,Ol8.Four com-pounds require five discontinuities; in the left elevation of Fig. 5are seen four eutectic dips, and the “ alteration point ” between CaOand Ca3A1,0, as a sudden change in the gradient, a little way upthe ‘‘ CaO mountain.” The third binary system, lime-silica, alsogives rise t o four compounds, Ca,SiO,, Ca,Si04, Ca,Si,O,, andCaSiO,; but, inasmuch as the first mentioned does not separateout from the fusion (owing its origin to a combination of CaO andCaSiO, when the conglomerate is cooled below 1900°), there areonly three “ effective ” compounds, and consequently four breaks.Three of these breaks (eutectics) are well shown on the back contourof the model, whilst the fourth, an alteration point between Ca,SiO,and Ca,Si,O,, is but faintly indicated.So much f o r the binary systems.I n order t o map out theternary system experiments were made with mixtures of fhe threecompounds representing 5 per cent. intervals of composition. Bythe application of the methods described in last year’s Report i twas then possible t o dekermine the nature and composition of thesolid phase which is the last to disappear on heating, and also thetemperature a t which the final trace of solid disappears. Havingin this way explored the main outlines of the system, the authorsproceded t o the examination of additional mixtures, appropriatel5 G. A. Rankin and F. E. Wright, Amer. J. Sci., 1915, [iv], 39, 1 ; A . , ii, 50.16 C. W. Kanolt, J. Washington Acad.Sci., 1913, 3, 3 1 5 ; A . , 1913, ii, 705244 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.for t.he final fixing of details. I n addition to the three originalcomponents and the binary compounds already mentioned, therenow appeared three ternary compounds. Two of these, namely,anorthite, CaAI,Si,O, and Ca,A1,SiOi (pure gehlenite a ) , arestable a t their melting points, whereas the third compound,Ca,A1,Si08, is unstable, and has consequently no place in thefollowing stability diagram and space model. The stability diagram(Fig. 4) is constructed on the equilateral principle, generallyadopted f o r systems of three components. Each and every pointinside the triangle represents a definite relative concenfration of thethree components.Thus, the point 3 a t the centre of the triangle,being equally distant from the corners, must obviously correspondFIG. 4.1 ...2 ...3 ...4 ...5 ...G ...7 ...Ca,Al,SiO .CaAl,O,.SiO,.CaAl,S,iO,.A1,0,.AI,SiOS.~a,A1,,0,,.with 339 per cent. each of lime, silica, and alumina. The point B,on the other hand, is closest to the silica corner and most remotefrom the alumina corner; it must therefore correspond with amixture in which silica preponderates over lime, and lime overalumina. boundary curves ” intofourteen stability fields, and in this way indicates the particularsolid phase which first crystallises from each and every conceivablemixture; thus the mixture A deposits the compound Ca,A1,SiOi;the mixture B, CaSiO, (pseudo-wollastonite), and so on.The faintlydrawn curves represent a few isotherms. Thus the mixture Bbegins t o deposit its pseudo-wollastonite as soon as the fusion iscooled t o 1400O; the mixture 3, its Ca,A1,SiOi, a little above 1400O.Any point on a boundary curve represents a particular mixture,The diagram is divided by thicMINERALOGICAL CHEMISTRY. 245wliicli on cooling wilI deposit two solid phases simultaneously ; thusthe mixture C commences t o crystallise a t 1700°, and forthwithforms a conglomerate of A1,0, and Al,SiO,>. The1 arrows on theboundary curve give the direction of falling temperatures. ‘‘ Quin-FIQ. 5.From a photograph of tiolid model showing relation of binary systemsCaO-Al,O, and Al,O,-SiO, to the ternary system.tuple points” like D and E , where three boundary curves meet,represent compositions which on crystallising immediately producea, triple conglomerate of solid phases.D is an absolute eutectic,since the temperatudes fall towards i t along all three curves; onthe other han’d, the point E is a quasi-eutectic, since the curve12-14 falls away from it.If i t is borne in mind t h a t the isotherms of the diagram (Fig. 4246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.are completely analogous t o the elevation-contour lines on a typo-graphical map it will become clear that the diagram is really a mapof the space model of Fig. 5 , in which the vertical dimension repre-sents temperature. The model, of course, gives a far better idea ofthe variations of temperature through the whole system.It must now be observed t h a t the diagram, or space model, isincomplete in one important particular, the nature of which cannow be described.Consider the fused mixture corresponding incomposition with the point B, in which silica preponderates overlime, whilst lime greatly preponderates over alumina. When crystal-lisation sets in, the first phase t o separate, namely, CaSiO,, has notthe composition of the fusion; more especially i t contains noalumina. The residual fusion accordingly becomes richer and richerin alumina ; its composition is no longer represented by B, but bya succession of points, the main trend being an approach towardsthe alumina corner of the diagram. It must now be stated that animportant part of the paper deals with the discussion of the trackof this moving point for every conceivable original mixture.It isseen from the diagram that this movement must soon bring B tothe boundary curve 7-12, and any further cooling must be followedby the appearance of the new phase 12, in the composition of whichalumina is represented. Further cooling leads t o a movement alongthe boundary curve 7-12 in the direction of falling temperature,namely, towards D. Finally, when the temperature of the residualfusion has attained this point a third phase appears, namely, silica(tridymite), and any further cooling is distinguished by a simul-taneous crystallisation of the triple eutectic conglomerate.Eutectic crystallisation of alloys is generally characterised by apeculiar interwoven structure-the so-called eutectic structure,which has frequently been invoked t o explain certain peculiaritiesin the texture of rocks.The authors have never been able to detectany trace of this structure i n the course of their work.The above few pages may perhaps convey a general idea as to thescope of a successful and complete investigation of a ternarysystem of minerals. Such work when prudently interpreted canbe made tc, yield real information as opposed t o “opinions” orspeculations ” concerning petrological problems. Whilst promisinga future discussion of this side of their work, the authors contentthemselves with pointing out t h a t the prediction they made t h a tthe main constituents of portland cement clinker must be the com-pounds CaSiO,, Ca,Si05, and Ca,Al,O,, has been decisively corro-borated by the subsequent work of P.H. Bates, of the Bureau ofStandards, Pittsburg. Another interesting point of detail is asfollows : The constituent Ca,SiO, occurs in three polymorphouMINERALOQICAL CHEMISTRY. 247modifications, a, /3, and y, the transformation /3 + y being accom-panied by a 10 per cent. increase of volume, which shatters thespecimen into fine dust. This behaviour is a matter of every-dayobservation in the burning of portland cement, and is technicallyknown as ‘( dusting.”System, dnorthite-Forsterite-Silica.’7-Adopting for the timebeing the fiction t h a t the system is ternary, we may proceed imme-diately t o a consideration of the general diagram (Fig.6). We see,of course, a division into several fields of stability; a few contourlines (isotherms) ; two quintuple points, 11 and B, having exactlythe same significance as in the preceding system. We may also notefrom the arrows t h a t silica and anorthite form an eutectic ( 1 3 5 3 O ) .Since the composition of forstarite is Mg2Si0,, it will be readilyappreciated t h a t the binary system, forsterite-silica, is a part ofthe more general system MgO-SO,, which was described in lastyear’s Report (p. 254). Kow the last binary system t o be con-sidered is not a little puzzling : mixtures corresponding with pointsbetween F and G deposit forsterite, and mixtures between K andL anorthite. That is quite regular; mixtures between G and K ,however, do not deposit a possible “molecular compound ” forster-itGanorthite, but the mineral spinel, MgA1,0,.There is, then, achemical reaction between the two supposed components; hence i tl7 0. Aiidersen, Amer. J . Sci., 1915, [iv], 39, 407; A , , ii, 361248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.follows t h a t the supposed ternary system cannot be completelyexplored per s e ; i t is an integral part of the quaternary systemCaO-MgO-Al,O,-SiO,, the successful working out of which will re-quire years of labour. Although the spinel stability field is repre-sented by the relatively small triangle GKLW, the separation of spinelhas a direct influence on the larger province FLM. With the exceptionof this province, the whole of the relationship can be elucidatedon the lines of a ternary system, with anorthite, fosterite, andsilica as components.Amongst other features of the paper are avery lucid account of the more important types of ternary systems,and a discussion of the petrological significance of the present work,which naturally throws a flood of light on magmatic resorption ofolivine and on the hitherto perplexing appearance of spinel incertain rocks.Effect of Temperature ou Crystnl dizgZes.-This subject has beeninvestigated by Rimel* within the wide limits of -170° and+600°. At -165O the rhombohedra1 angle of calcite is 74O44‘,whilst a t 596O the angle has increased t o 75O534’; the value accepteda t the ordinary temperature is 74O55’ (Wollaston).The variationof the rhombohedra1 angle with the temperature is not so great inthe case of the other carbonates, the order being calcite, rhodo-chrosite, dolomite, and chalybite. The variation of the angle(001) : (070) f o r the plagioclase felspars was also studied, the orderof magnitude being albite, hbradorite, and anorthite.Diff eretbtintion in Silicate Piisioizs.The differentiation of an originally homogeneous liquid magmainto chemically distinct layers o r sections by processes of diffusion,gravity, convection currents, and the like, has frequently beeninvoked by petrologists in the interpretation of the complex localproblems presented by rocks. It would appear that the operationof gravity in bringing about a sinking of relatively heavy crystalsin the fluid magma has lately acquired disfavour, but the experi-mental work of Bowen 19 serves to establish its truth beyond dispute.The work may be regarded as a petrological extension of the purelyphysico-chemical research noted in last year’s Report, The cruciblecontaining suitable charges of diopside and enstatite was held f o rdifferent periods of time a t a temperature appropriate for a crystal-lisation of 4 per cent.of forsterite, and then chilled so as t o vitrefythe remaining 96 per cent. of liquid. A vertical section cut throughthe mass permitted the microscopical determination of the amountF. Rinne, Centr. Min., 1914, 7 0 5 ; A . , ii, 367.l9 N. L. Bowen, Amer. J . Sci., 1915, [iv], 39, 175MINERALOGICAL CHEMISTRY.249of settling of the forsterite crystals due to gravity. The photo-graphic reproductions are conclusive. A similar gravity-differentia-tion was proved t o hold for mixtures which yield pyroxene insteadof forsterite. By measuring the velocity of settling and by utilisingthe results of other researches on mineral, rock, and magma densi-ties,20 the viscosity of the fusion was estimated t o be about fourhundred times t h a t of water, or, say, about half t h a t of glycerol.117hen crystallisation of such fusions as first deposit forsterite(olivine) was allowed to complete itself the upper part of the masswas found t o consist of pyroxene and free silica, the lower part ofpyroxene and olivine-the dissociation of pyroxene into forsteriteand silica involved in these experiments was discussed last year.This differentiation occurs in the field in a large scale in thePalisade diabase, described and correctly interpreted by Lewis.*’Play o f Colozirs ( A venturiscstion) in Felspcrr.Many gem stones owe their pretty effects t o a play of colourbrought about by the reflection and interference of light a t theupper and lower surfaces of visible, included lamellre of anothermineral. The property is shared by many felspar specimens t o agreater o r lessextent, as in (‘ sunstone ” and in ‘‘ aventurine ” varie-ties respectively. The moonstone and labradorite effects arepossibly due to a similar cause; but the lamelle, if existent, aresub microscopic.A notable contribution t o the subject of aventurisation has beenrecently published by Anderwn.22 The minerals investigated in-cluded albite, oligoclase, and micrccline-perthite from various locali-ties.An intelligent use of the two-circle goniometer enabled a veryprecise determination of the internal structural planes along whichthe generally platy hamatite lamella are arranged. The coloureffect on (001) is chiefly caused by lamella along the plane (112)and to a less extent (Ira), whilst the effect on the surface (010) isalways due to lamella parallel t o the structural planes (150) and(150). Less important planes of lamellation are ( i i q , (iio), (IIO),(021), ( O l O ) , and (001). The edges of the lamellae do not appeart o favour any particular orientation.Postulating a refractiveindex of 3 f o r hematite, Andersen deduced from the polarisationtints a thickness 50-100 ,up for the thinnest and 100-400 ,up forthe average lamell=. The longest lamella: observed measured3.5 mm. The platy face of the lamelle agrees optically with the* O A. L. Day, R. B. Sosmaii, and J. C. Hostetter, Amer. J . Sci., 1914, [iv],37, 1.21 J. V. Lewis, ‘‘ Annual Rep. State Geologist New Jersey,” 1907, 127.z2 0. Andersen, Amer. J . Sci., 1915, [iv], 4.0, 351250basal plane of hamatite. It will be noticed that the structuralplanes most favoured by the lamella are of extremely rare appear-ance on felspar crystals. This observation may be used as anargument against the view that the hEmatite crystals were depositedon the faces of the growing felspar crystal.Thermal experimentsprove t h a t the lamellze only disappear a t a temperature of 1 2 3 5 O , a twhich incipient fusion of felspar can dissolve hamatite. The mostsatisfactory view of the origin of the lamelle is that they existedin the original felspar in solid solution, and that subsequent coolingled t o an unmixing of the hamatite along certsin planes (of glidingor translation 1).ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Polymorphhm.The need was expressed in last year’s Report f o r a trustworthymethod of distinguishing between polyinorphous and isomeric(including tautomeric) modifications. An ingenious method hasbeen devised during the yeir by Sidgwick,23 depending on thesolubility. If to a saturated solution of the more soluble of twopolymoi-phous modifications some of the other modihation is addedthe concentration of the solution will not increase, since the twoforms give the same molecule in solution ; on the contrary, it willdiminish t o a greater or less extent, depending on the differencein solubility of the two forms, although this difference may be toosmall t o measure.If, on the other hand, the two forms are isomericor tautomeric, the addition of the less soluble form will cause anincrease in the concentration of the solution, f o r chemically differentmolecules do not seriously influence each other’s solubility. As ameasure of the concentration of the solution, Sidgwick determinesthe cryohydric point, using an ordinary Beckmann apparatus.Thecryohydric points are determined in some suitable solvent f o r thetwo forms separately and then f o r the two forms together. Ifpolymorphous, the mixture of the two forms will give a point lyingbetween those of the separate forms; but if isomeric (or tautomeric)the point given by the mixture will lie below that of the moresoluble form, the depression of freezing point by the two togetherapproximating t o the sum of the individual depressions. I n thecase of camphoric anhydride, f o r example, the d-form alone gave adepression of 0.99l0; the (7- and I-forms together, a depression of1‘7870. The method has already been used in connexion with someof Chattaway’s polymorphous substances and certain derivatives ofcryptopine, t o be described by W.H. Perkin. The method has thegreat advantage that, as i t takes only a few minutes t o carry outa t a low temperature, the probability of the two forms (if indeed23 N. V. Sidgwick, T., 1918,107, 672; G. Bruni claims priority, A . , ii, 827MINERALOGICAL CHEMISTRY. 251they are not polymorphous) coming t o tautomeric equilibrium inthe course of the experiment is greatly diminished.The effect of pressure on the polymorphous temperature, as alsoon the melting point, of some thirty compounds has been investi-gated by Bridgman24 with an apparatus allowing of the employ-ment of a pressure of 12,000 kilograms per sq. cm. The results a.reepitomised in a series of curves, and prove that the phenomena ofpolymorphism are extremely complicated ; although in most casesan increase of pressure either steadily raises or lowers the transitiontemperature, there are others, as, for example, mercuric iodide, inwhich the curve rises to a maximum and then falls without betray-ing any discontinuity.Two papers by Chattaway and Lambert 25 on the polymorphism ofcertain organic compounds are of a special interest.The firstcontains a description of the monotropic p-bromoacetanilide and2 : 4-dibromoacetanilide. It is shown that both these compoundsare particularly suitable for demonstration or lecture purposes. Thebeliaviour of the two substances is much the same; on allowing abeaker of an alcohclic solution t o cool, a copious formation of thelabile modification takes place.The crystals consist of fine needles,and are so bulky as t o fill the vessel completely. After some timecompact crystals of the stable form make their appearance a t thetop of the mass, and, growing a t the expense of the needles, gradu-ally sink down t o the bottom of the beaker. The various stages areillustrated by an excellent. series of photographs. The suggestionis made that some of the accepted examples of monotropism mayreally be cases of enantiotropism with a low transition 'temperature.The second paper relates t o some new examples of enantiotropism,and incidentally cont'ains the first recorded experimental verificationof a law originally deduced by van't Hoff concerning the relativesolubilities of reversible modifications in different solvents.Enan tiomorphism.With the possible exception of the puzzling element nitrogen, thehistory of stereochemistry has been mainly occupied with the ex-ploitation of the original tetrahedral hypothesis of carbon valeaciesand it5 logical application t o other quadrivalent elements. It isonly quite recently t h a t we owe a new departure t o the geniusof Werner,20 who has enriched chemistry with an entirely noveltheory of chemical constitution, embodying the co-ordination of a24 P.W. Bridgman, Proc. Nut. Acad. Sci., 1915,1, 51 3.25 F. D. Chattaway and W. J. Lambcrt, T., 1915, 107, 1766, 1773.26 A. Werner, " Neuere Anschauungen auf dcm Gebiete der anorganischenChernie " (1013)252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.number of atoms o r groups round a central nucleus by virtue ofsubsidiary valencies.The co-ordination number is generally fouror six; the first alternat'ive needs no special comment, inasmuch asthe arrangement is probably tetrahedral. I n hexa-co-ordinatedcompounds, however, the special arrangement has had t o be deducedde VOZIO, and Werner has demonstrated with a high degree ofcertainty that the groups are arranged round the central atom a tthe six corners of an octahedron. The octahedral structure neces-sarily introduces new possibilities of isomerism and, more parti-cularly, molecular enantiomorphism. One property of the arrange-inent may be noted; the higher symmetry of the octahedron, ascompared with the tetrahedron, allows of a highly symmetrical typeof snantiomorphism.Thus, in the luteotriethylenediamine cobalticsalts of the general formula [Coen3]X3, in which en is the conven-tional abbreviation of the symmetrical group. . . NH,-CE€,*CH,*NH, . . .and X any acidic group, the positive ion [Coen,] can exist in thetwo enantiomorphous configurations indicated below, formulzwhich exhibit the symmetry of the quartz class :en en<I 17L-1 'd/ ' '0 d e n en\-'' ~-~ I -~ \ \en enThe crystallographic examination of a number of optically activecompounds of the above series has been undertaken by Jaeger27with the following results. The perchlorate and nitrate,[Co en3](C10,), and [Co en,](NO,),, both crystallise in'--the rhombicsystem, and .clearly show a hemihedral or sphenoidal development.On the' othe'r hand, the optically active bromides (and chlorides)crystallise with two molecules of water in the tetragonal system;there is no geometrical sign of hemihedrism, and the result of etchingexperiments also' agree with hololiedral symmetry.The same failureto prove anything but holohedral symmetry attended the investiga-tion of the optically active rhombic iodides, [Co en3]13,Hz0, and theanhydrous thiocyanates, [Co en,](CNS),. After stating that i t isdogmatic t o accept the Past,eur principle in view of the presentwork, Jaeger raises the question whether it is not possible for thesehighly symmetrical, enantiomorphous molecules t o yield a holo-hedral structure, which shall nevertheless rotate the plane of2 7 F.M. Ja?gx, Proc. K . Akad. Wetensch. Amsterdam, 1915, 17, 1217;18, 1 ; A . , ii, 399MINERALOGICAL CHEMISTRY. 253polarised light by virtue of the enantiomorphism of the componentmolecules, and he considers that his facts establish the possi-bility.*The number of biaxial crystals of proved rotatory power issteadily increasing. The rhombic, bisphenoidal magnesium salt ofZ-malic acid, C4H,0,Mg,5H20, has a rotatory power of - 1 2 O forsoldium light, whilst I-asparagine gave the value - 6 7 O (1 cm. thick-new in both cases).28 The rotatory dispersions are moderate. Thelatest addition is lithium sulphate, Li,S04,H,0, a well-knownexample of the enantiomorphous class of the monoclinic system.2gThe axial plane is perpendicular t o (OlO), and the expectation thatthe rotatory power should have equal values along the two axeswas realised. The mean value for 1 mm.thickness is 1°48/f39/(Na light). I n a dextrorotatory crystal the analogous pyroelectricpole lies a t the positive end of the symmetry axis. A notable itemof thel paper is a description of a new mechanical arrangementf o r obtaining perfect crystals a t any constant temperature. Itis inberesting to note t h a t the rotatory power of lithium sulphatewas anticipated by Barker and Marsh,30 who suggested for the salta spacial configuration founded on the constitutional formula[SO3(OH)2ILi,*I n a brief paper by Barlow and Pope31 i t is pointed out that28 V. V. Karandhev, “The Measurement of Rotary Power in Biaxial29 A. Johnsen, Centr.Min., 1915, 233.30 T. V. Barker and J. E. Marsh, T., 1913, 103, 837.31 W. Rarlow and W. J. Pope, T., 1915, 107, 700; A , , ii, 527.Crystals ”-Russian (1913).* Those who are familiar with the history of stereochemistry will rccognisethat Jaeger’s conclusions amount to a re-opening of the Walden-Traukecontroversy. Whilst expressing the view that Jaeger’s work on the Fa--chlorates and nitrates must acquire historical imFortance, the writer of thisReport must say that both the experimental evidence and the theoreticalconclusions relating to the bromides, iodidcs,and thiocyanates leave somethingto be desired. The general forms ( h k 2) were only developed in the singlecase of the thiocyanates. I n the diagram of the d-crystal thay are prcEEntcdholohedrally as very small facets ; but in the case G f the E-crystal the forms0:121j and w f l l l ) are actually drawn hemihedrally.The evidence withregard to the remaining compounds consists of etch figures; but such figurescan be symmetrical for the same structural causes which operate in theproduction of a holohedral form. Moreover, added to these matters ofdetail, there is a general difficulty (which is insurmountable, unless anyoneis willing to transform fundamentally the question a t issue by subscribingto the view that optical activity is to be expected in a non-enantiomorphousstructure). Jaeger’s crystals are optically active, as far as he probed thematter. If this optical activity is not due to the enantiomorphous crystalstructure (Jaeger’s contention), it must be due to enantiomorphism of themolecule.Enantiomorphous molecules (all dertro or all Zaevo), however,can not be built together to yield a holohedral crystal structure254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Barker and Ailsrsh3° have fallen into an error in concluding thatany optical activity in a biaxial crystal must necessarily be attri-buted to an enantiomorphous configuration of the chemical molecule, f o r i t is potsible to conceive homogeneous assemblages ofatomic centres, which, although enantiomorphous as a whole, are,nevertheless partitionable into. non-enantiomorphous moleculargroups of atoms. As examples are quoted those assemblages inwhich i t is possible t o trace spiral axes that are simultaneouslydigonal for one kind of atomic centre and tetragonal or hexa-gonal f o r another kind.lsom or phis m.Two papers are t o be noted, one by Jaeger,32 the other byJaeger’s researches refer t o the iscmorphous group of Tutton.33rare earth ethyl sulphahs of the, general formulaR”’( SO,Et),,SH,O,in which R”’ represents yttrium, lanthanum, cerium, praseodym-ium, neodymium, samarium, europium, gadolinium, dysprosium,erbium, thulium, and neo-ytterbium.The crystallisation is hexa-gonal, the symmetry t h a t of apatite-as was indicated by a Lauuradiogram and etch-figures. The crystals were very well developedand the angles trustwortthy; the deviations in going from one saltto another are only a matter of a few minutes, so that the probablevalue c:a=O~5062+0*0012 can be accepted for the whole series.The molecular volumes, however, are distinctive, so that the individu-ality of each salt reappears in the form of topic axee. The corre-sponding compounds of indium and scandium do not belong to thesame series, and in order to probe their crystallographic relation-ships more fully the author prepared and examined acetylaceton-ates of scandium, indium, aluminium, ferric iron, and glucinum,and found that the first three metals produce an isomorphousseries.The monoclinic glucinum compound exhibits such extra-ordinarily high dispersion of both optic axes and principal opticdirections as have probably never been observed in any othercompound.Excoption to some of Jaeger’s theoretical conclusions has beentaken by Tutt’on, who shows that the above work does not in theleast invalidate the conclusions derived from twenty years’ workon the simple and double sulphates and aelenates. A t least threefactors operate towards the extreme closeness in the angular valuesobserved by Jaeger: (1) small vasiations of the atomic weightsconcerned, (2) the mass effect of the remainder of the molecule,32 F.M. Jaeger, Rec. traw. chim., 1914, 33, 343; A . , 1914, i, 797.s3 A. E. H. Tutton, Phil. Trans., 1915, [ A ] , 216, 1; A . , 1916, ii, 38MINERALOGICAL CHEMlSTRY. 255(3) the high symmetry of the hexagonal sysbem. Jaeger's resultsare tlierefore to be expected. Tutton's paper is mainly occupiedwit,h the systeir-atic, morphological, and optical examination of thesalts (NH,),M(S0,)2,6H,0, in which M denotes nickel, cobalt, man-ganese, copper, and cadmium.The general results of the workare now so well known that i t need only be stated that the presentresults amply confirm all previous deductions concerning thecrystallographic position of ammonium in the alkali series.Morpho tropg.Certain new morphotropic relationships among compounds ofcyclic structure are discussed in a recent paper by Groth,34 who, itwill be remembered, was the first t o call attention t o the desiraibility of investigating closely allied organic series of compoundswith a view to discover any laws which might govern the mutualreplacement of simple radicles. Full use is made of topic axes inorder to emphasise the quantit'ative side of the following resem-blances :X .4. w. B.Imide of succinic acid ... 3.193 : 4.048 : 5.527 : 90'0'Imide of s-dimethyl-Imide of tetramethyl-succinic acid ............ 3-982 : 4.351 : 5.762 : 100 10succinic acid ............ 3.415 : 5.425 : 7-063 : 02 8A comparison of the above values is believed t o lay bare certainmorphotropic regularities due to the regular type of chemicalreplacement. Now the st'ock example of this kind of regular pro-gression is that given bellow, in which there would seem to be aprogressive alteration of the crystal structure when hydrogen isreplaced by methyl, ethyl, and propyl groups:a : b : c X - 4. a'.NH,I ............ 1 : 1 : 1 3.860 3-860 3.860NMe41 ............ 1 : 1 : 0.7223 5.319 5.319 3-842NEt,I ............1 : 1 : 0.5544 6.648 6 648 3.686NPr,I ............ 0.776: 1 : 0.6283 6.093 7.851 4.933It has, however, been recently urged by Barlow and Pope% thatthe indices (100) and (111) of the tetramethyl compound shouldbe replaced by (110) and { l O l } , the justification being that thenew indices are simpler and a much bet8ter reflection of the dodecaihedral habit of the crystals. The proposed change invdvee a modi-fication of the ratio c : a by the amount y'2; the new value becomes1*0214, and indicates pseudo-cubism. It is then concluded thattopic axes are of little o r no value in morphotropic comparisons;34 P. Groth, Zeitsck. Kryst. Min., 1915, 54, 498.35 W. Barlow and W. J. Pope, Phil. Mag., 1915, [vi], 29, 745; A., ii, 427256 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRYthe geometrical constants of some twelve substances, chemicallyallied t o ammonium iodide, are passed in review, the final conclu-sion being that all the structures concerned are pseudo-cubic.The divergent views indicated above merit a little discussion,since they bear on the general subject of crystal morphology. Itmay be observed that Groth was guided by cleavage in the choicehe made of the alternative methods of describing the tetragonalcompound.The only reason Barlow and Pope give f o r changingthe setting is simplicity of indices.” * The connexion betweenindices and crystal structure deserves a little examination.I n text-books i t is generally stated that the fundamental lawof geometrical crystallography is the law of rational intercepts orindices. However true this may be, i t is, nevertheless, not thelaw of morphologica.1 crystallography.The law of rational indicescontains no limitations on the number and nature of faces actuallydeveloped on a crystal; for example, the law will allow of crystalsbeing “spheres,” since a sphere can be regarded as a myriad ofplane faces having the general indices { co - 112, c%, - 1 ~ , co - p }, inwhich 00 is meant t o connote a very large number as comparedwith m, n, and p . Fortunately, observations show that crystals arebounded by a certain number of plane faces; to treat crystallo-graphy as a purely geometrical problem is t o shut one’s eyes tothe main facts of the science.It is frequently added as a corollary in the textrbooks that theindices are simple numbers.This marks a real advance, but i t isstill unsatisfactory unless it is simultaneously pointed out that sim-plicity of indices largely depends on a happy choice of axial direc-tions A , R, C. The anorthic isomorphous series, typified byethyleaediamine manganese sulphate, C2H,(NH3),SO,,MnSO,,4H20,as described by Rosickjr,3’j has the form development: (OlO), (110),(8 : 24 : 3). Them complicated indices by a suitable transformationbecome term for term (TlO), (TOl), ( O i l ) , ( l l l ) , ( O l l ) , (101), (lll),The question as to how far a crystal obeys a law of simple indicescan only be quantitatively probed if we can decide on a measure ofsimplicity ; whether, for example, simplicity is t o be measured bythe actual summation of indices or of the indices squared.I n his(iio), (ooi), (m), (i33), (4 : i Z : 31, (4 : 18 : 3), (263), @3), (803)-( i l l ) , (oio), (loo), (iii), (31 I).36 V. Rosickjl, Zeitsch. Kryst. Min., 1909, 46, 3 5 7 ; A., 1909, i, 458.* They would, however, seem to think that it is not necessary t o adheret o this principle throughout the whole of their paper; for in subsequentattempts to support their thesis of pseudo-cubism they have recourse in somethree cases to a multiplication or division of an axial ratio by 2, a procedurewhich leads to complicated indicesM I SE It A LOG1 C AL CH E 3.1 1 ST R Y . 257comprehensive examination of this question, Fedorov 37 adopted thelatter criterion.As a result of this work it must be concludedthat crystal morphology does agree, in the main, with the p ~ n c i p l eof simple indices-provided the descriptive conventionalities nowin vogue are mercilessly discaxded. I n the rhombic system, forexample, one must be willing to adopt no fewer than four systems ofselecting the Rxial directions A , B, C ; one must also be preparedto adopt a system of four axea and indices, not merely in hexa-gonally developed crystals, like quartz, belonging to the hexagonal-rhombohedra1 system, but also in certain crystals of the rhombic,monoclinic, and anorthic systems. The’ proviso first mentionedactually leads t o great confusion, for faces of the same form mayacquire t o b lly different indices.Whilst adopting a judicious urnof the hexagonal form of indices (for crystals of the “hypohexa-gonal type ”), Fedorov shrank from carrying through the principleto its logical conclueion.A rigorous employment of this principle, of simple indices isreally a purely morphological queskion-that is to say, it needhave no reference to the structure, but if we bear in mind that thegeometrical axes A , B, C, thus located, must be identical withcertain structural directions of the lattice, we see that the selectionof a standard set of axial directions and ratios, a : b : c, by meansof the principle of simple indices, is practically equivalent withthe discrimination of crystal structure by means of the Bravaisprinciple.The sole difference lies in (generally small) quantitativedetails; in the cubic system the two methods are identical. Theprinciple of indices could never be regarded by a crystallographeras anything but provisional; i t was therefore a logical step tosubstitute for i t a structural conception like reticular density orarea, especially as the substitution greatly lightens tEe actualprocess of analysis of crystal morphology; for example, there needbe no recourse to four distinct selections of A , B, C in a rhombiccrystal. Fedorov 38 foreshadowed this substitution in the year 1903.Simultaneously, but quite independently, Friedel 393 40 was exam-ining morphology in the light of the Bravais principle. I n anextremely important series of papers, which appear to haveattracted little, IT any, attention, Friedel demonstrated that crystalfaces can be regarded as due to the development of the most highlybeset planes of the structural lattice.Although these are frequentexamples in which anticipated planes are not actually observed,37 E. S. Fedorov, various papers in Zeitsch. Kryst. Min., 1902-1903.’* Ibid., 1903, 38, 321.39 G. Friedel, “ ]Etude sur les groupements cristallins” (1904).40 Bull SOC. franp. &tin., 1907, 30, 326; 1908, 31, 5.REP.-VOL. XII. 258 ANNUAL REPORJ‘S ON THE PROGRESS ok‘ CHEMIS’lHYthere is, nevertheless, a remarkable agreement on the whole. Acursory inspection of Friedel’s studies will reveal the fact that theorder of reticular densities do- not in general follow the orderof simplicity of the indices allotted to the faces. This is partlydue to his adoption of the conventional rules for selecting -4, B, C ;the want of harmony is, naturally, especially marked in pseudo-hexagonal crystals.The work of Fedorov and Friedel is so recent that it has nothad time to make itself felt in crystallography. It serves to accen-tuate the truth that the work of the average morphologist is super-ficial. The measurer of crystals has been content to fall back onthe great latitude allowed by the law of rational indices, even whenhe is occupied in such ambitious work as deducing morphotropicresemblances. It is surely obvious that such work has no exactmeaning or consequence when no effort has been made to analysethe morphological data and so circumscribe the infinite numberof possibilitiee allowed by the law of rational indicm. Whetherthe resemblances or comparisons are expressed in terms of axialratios, topic axes, or equivalent parameters has no bearing on thepoint a t issue. Cogency, of course, is not to be denied to all thepublished resemblances. I n absence of any experimental method ofprobing crystal structure,* the cogency of a reputed resemblancecan only be estimated by the success with which it undergoes thetest of the Bravais principle-a principle which, indeed, epitomisesthe simple relabionship between the1 various faces observed oncrystals of some thousands of substances.With regard to the particular morphotropic resemblances underdiscussion, the application of the Bravais principle reveals someessential structaral differences, for certain lattices are central whilstothers are not; to this extent are Barlow and Pope supported intheir objection, On the other hand, the principle does not confirmBarlow and Pope’s idea of pseudo-cubism. It must be noted thatthel question of pseudo-cubism has been thoroughly thrashed outby French crystallographers. Both Mallard and Wallerant have intheir time subscribed to the view that a good many crystals arepseudo-cubic. The question was finally put a t rest by Friedel, whoshowed that pseudo-cubism is a universal property of crystals,whex the structural space lattice is regarded in a purely geometri-cal sense.T. V. BARKER.* I t need scarcely be stated that the recent development of X-ray workpromises to afford trustworthy experimental evidence. It will, however,probably be some years before the method becomes general in crystallographiclaboratories. I t is, perhaps, too much to expect the general physicist t oacquire an interest in matters of crystallographic detail

ISSN:0365-6217    

DOI:10.1039/AR9151200234

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

INDEX OF AUTHORS' NAMES.Abderhalden, E, 77.Aboulenc, J., 69.Adams, L. H.. 172.-4gulhon, H., 230.Aiyer, P. A. S., 216.Albert, 167.Aldrich, T. B., 206.Alessandri, L., 140.,411en, H. S., 2.Sllmand, A. J., 26.,4ndersen, O., 247, 249.*4nderson, H. P., 224.,4nderson, V. G., 210.Angel, L., 59.*4ngeli, A., 140.Appleyard, A., 214.-4schan, O., 83.Atack, F. W., 173, 176.Aten, A. H. W., 37.,4ubry, A., 75.Auer, J., 51.Augustin, H,., 39.Auld, S. J. M., 47.-4uwers, K. von, 96, 121, 154.Baeyer, A., 149.Bailly, O., 68.Balareff, D., 58.Balduzzi, G., 124.Balke, C. W., 29.Baly, E. C. C., 6, 7, 23.Bamberger, E., 114.Baravian, A., 135.Bargellini, G., 75, 153.Barger, G., 144, 163, 164.Barker T. V., 21, 253.Barlow: W., 253, 255.Barnebey, 0.L., 177.Bart, H., 126.Barthelmes, E., 131.Bates, P. H., 246.Bauer, H., 123, 125, 130, 169.Baxter, G. P., 27, 28, 29, 40, 61.Beebe, S. P., 208.Beesley, R. M., 109.Benary, E., 135.Bender, J., 44.Benedict, F. G., 187, 188, 189.Benedict, S. R., 208.Bennett, G. M., 8.Bergius, F., 91.Berlitzer, H., 98.Bernini, A., 40.Bertheini, A., 125, 127.Biltz, W., 39.Birchard, F. J., 196.Blanck, E., 213.Blasi, N., 126.Blish, M. J., 217.Blum, F., 207.Blumann, A., 123.Boeseken, J., 73.Bohart, G. S., 57.Bohn, A., 148.Bohr, N., 1, 2.Boll, M., 24.Boller, E., 39.Boltina, (Miss) M. IT., 5.Bolton, E. K., 157.Bonomarev, J., 44.Boon, A. A., 108.Bornebusch, C. H., 222.Borsche, W., 94, 100, 101. 122. 150.Bosch, J.C. van den, 37.Boshooski, V., 120.Bottomley, W. B., 218, 227. 232.Bougault, J., 104.Bourquelot, E., 75.Bowen, N. L., 248.Bragg, W. H., 234, 236, 238. 240.Bragg, W. L., 234, 236, 238.Bramley, A., 17.Braun, O., 96.Brauns, M., 110, 111.Bredenberg, J. A. W., 159.BrBtigniBre, L., 232.Bridel, M., 75.Bridgman, P. W., 251.Briggs, J. F., 182.Briscoe, H. V. A., 29.Broderson, H. J., 55Bronf enbrenner, J, 202.259 K 260 ISDEX OF AUTHORS’ NAMES.3rown, W. D., 176.3rown, P. E., 226.3ruin, G. de, 37.3rune1, R. F., 88.3runi, G., 250.3uddin, W., 219.3urda, J., 89.3urgess, P. S., 224, 232.3ygd6n, A., 129.Calcagni, G., 74.Calderaro, E., 133.Calzolari, F., 61.Cameron, A. T., 207.Campbell, E. D., 59.Canac, F., 235.Cantoni, C., 40.Cardwell, D., 90.Carles, P., 43.Carney, R.J., 59.Cartier, J., 238.Cazanecki, P. V., 51.Centnerszwer, M., 45.Charrier, G., 116.Chattaway, F. D., 116, 251.Cherbuliez, E., 113.Chick, H., 195.Choudhri, T. C., 38.Christensen, A., 159.Christensen, H. R., Bl, 226.Ciusa, R., 160.Cohen, E., 36, 37.Cohen, J. B., 89.Coli, C., 124.Collie, J. N., 151.Colman, H. G., 181.Conn, H. J., 220.Contardi, A., 88.Coope, R., 200.Copisarow, M., 96.Cornelius, W., 123.Courtot, C., 117.Crehore, A. C., 241.Csonka, F. A., 197.Cumming, A. C., 177.Cunningham, R., 220.Curtis, W. E., 2.Curtius, T., 83.Dakin, H. D., 195.Dale, J. K., 73.Daniels, L. C., 43.D’Ans, J., 77.Davidson, J., 229.Davis, M., 197, 200.Davis, 0.C. M., 99.Davis, W. A., 186.Dawson, H. M., 18, 20.Day, A. L., 249.Dennis, L. M., 178.Dickinson, H. C., 32.D’Ippolito, G.. 231.Do jarenko, A. G., 216.Dormann, E., 169.Dorn, W., 142.Dougherty, G. T., 179.Drew, H. D. K., 80, 106.Drukker, J., 45.Dubois, E. F., 190.Dudley, H. W., 195, 199.Dunlea, J. M., 150.Dunoyer, L., 4.DuprB, J. V., 211.Dziewonski, K., 119.Eck, J. J. van, 182.Egerton, A. C. G., 23, 35.Ehrlich, P., 126, 127, 130.Eichwald, E., 77.Eissler, F., 76.Elliot, J. C., 123.Embden, G., 199.Emmert, B., 141, 142.Engelbertz, E., 135.Engler, C., 64.English, S . , 9.Ephraim, F., 38, 39.Erdmann, E., 69.Erlenmeyer, E., jun., 81, 108.Evans, E. J., 2.Everest, A. E., 156.Ewart, A. J., 166.Fabaro, L., 31.Farbwerke vorm.Meister, Lucius, &Bruning, 206.Favorski, A., 120, 147.Fawcett, G. G., 208.Felkenhauer, B., 39Fenger, F., 206.Fichter, F., 62.Field, (Miss) E., 144, 163, 164.Fieldner, A. C., 180.Filippo, J. D., 182.Fischer, E., 70, 72, 75, 86, 87, 94.Fischer, H., 139, 168, 170.Fischer, V. M., 62.Fleischer, K., 162, 163.F Q O ~ , H. W., 43.Foreman, %. W., 194.Forster, M. O . , 116.Fortelli, E., 183.Francis, F. E., 20, 173.Franck, J., 3.Franke, A., 68.Frankfurter, F., 112.Frankland, P. F., 80.Franklin, E. C., 56.Franzen, H., 93.Fraser, A., 175.Frazier, C. H., 208.Fred, E. B., 225.Freund, M., 159, 162, 163.Freundlich, H., 14, 15.Freytag, P., 97.Fricke, H., 66iNDEX OF AUTHORS’ NAMES.261Friedrichs, 0. von, 95.Fries, K., 135.Fromm, E., 123.Fry, H. S., 88.Fuchs, W., 93.Fiihner, 206.Funk, C., 201, 202.Fyfe, A. W., 71.Gaines, W. L., 205.Gamble, J. L., 190.Garner, W. E., 80.Garrett, C. S., 5, 59.Gautier, A., 231.Gavrilov, N. N., 111.Geake, F. H., 20, 173.Gephart, F. C., 190.Ghosh, B. N., 136, 148, 152.Ghosh, S., 73.Gibson, C. S., 87.Giua, A%., 88.Glagoleva, (Miss) A. A., 9.Glenny, A. T., 209.Goldstein, E., 172.Gomberg, M., 112.Goodey, T., 221.Gortner, R. A., 217.Goudriaan, F., 52.Graziani, F., 87.Greaves, J. E., 224.Griffin, M. L., 174.Grimbert, L., 68, 180.Gsose, M. R., 61.Groth, P., 255.Grover, F. L., 27.Griitzner, R., 207.Guggenheim, M., 206.Gntbier, A., 53.Haagen, W.K. van, 30.Haarmann, R., 95.Haga, H., 240.Hall, N., 105.Hamburger, L., 53.Hammond, J., 204.Hantzsch, A., 93, 116.Harper, E. M., 146.Harries, C., 65, 95.Harrison, W. H., 216.Hart, E. B., 225, 231.Hartley, P., 194, 196.Hartmann, N. L., 30.Hartwich, C., 166.Hase, E., 15.Hauser, O., 14.Hedallen, J., 174.Hedenburg, 0. F.. 71.Heimbiirger, G., 94, 101.Helderman, W. D., 36, 37.Hele, T. S., 193.Heller, H., 37.Heller, M. G., 150.HemmerlB, (Mlle.) R., 104.Henderson, J. B., 182, 183.Henderson, J. P., 3.Henglein, A., 93.Henrich, F., 95.Hertz, G., 3.Hess, C. L. von, 203.Hevesy, G. von, 10, 11.Hewitt, J. T., 92.Hilgendorff, G., 81, 108.Hill, R. L., 204.Honigschmid, O., 28.Hoesch, K., 97.Hoffmann, La Roche & Co., F., 206.Hogg, T.P., 71.Hollely, W. F., 91.Holleman, A. F., 88, 89.Hoobler, B. R., 190.Hoover, C. R., 27, 28.Hopfer, G., 104.Hupkins, C. G., 230.Horovitz, (Mlle.) S., 28.Hostetter, J. C., 249.Houseman, H. V., 173.Howard, A., 216.Howard, G. L. C., 216.Hudson, C. S., 72, 73, 76.Hiilsen, G., 202.Huender, A., 90.Hulett, G. A., 30.Hunter, A., 206, 207.Hurst, (Miss) W. G., 92.Hutchinson, H. B., 213, 220.Hynes, J. E., 105.Ingold, C. K., 109.Iocitsch, S. I., 78.Irvine, J. C., 68, 70. 71, 72, 73.Isuji, K., 203.Ivanovski, D., 166.Jacobson, S., 152.Jacoby, M., 204.Jaeger, F. M., 9, 240. 252, 254.Jaffe, E., 183.Jahnsen, A., 38.Janicki, L., 5.Janney, N. W., 197.Jickling, R. L., 112.Johnsen, A., 253.Johnson, J.M., 76.Jones, G. C., 181.Joshi, N. V., 225.Kahn, J., 9.Kalischev, A., 67.Kanolt, C. W., 243.Kappeler, H., 62.Kappen, H., 226.Karandhev, V. V., 253.Karmanov, S. G., 137.Karrer, P., 115, 125, 126, 127, 151.Keesom, W. H., 31.Kehrniann, F., 148262Kellogg, E. H., 226.Kendall, E. C., 208.King, C. E., 203.Kipping, F. S., 92.Kirschbauni, M., 4.Kishner, N., 64.Knecht, E., 174.Kneip, A., 77.Knox, W. K., 211.Knndsen, P., 82.Kober, P. A., 195.Koch. O., 165.Kohler. W., 5.Komer, W., 88.Krannich, W., 170.Kratzmanii, E., 231.Krellwitz, L., 164.Krogh, A , , 189.Krotkov, D., 9.Kunzer, R . , 4.Kiister, W.. 168, 169.Kurnakov, I., 9.Kws, E., 48, 51.INDEX OF AUTHOHS' NAMES.Laan, F. H. van der, 182.La Forge, F.B., 74, 75.La Franca, F., 199.Lajoux, H.. 131.Lam, A, 182.Lambert, W. J., 251.Lamble, A, 20.Lammer, P., 98.Landsberg, G. S., 26.Langmuir, I., 40.Lapworth, A . , 18, 19, 103, 105Laquer, F., 199.LBsx16, E. D., 72.Leather, J. W., 215.Leavenworth, C. S., 196.Le Brazidec, M., 120.Lecher, H., 114.Leclkre, -4., 180.Lee, I. E., 173.Lemon, B. J., 178.Lenz, W., 172.Lesser, R., 119, 123, 130.Leuchs, H., 103, 160.Levene, P. A., 74, 75.LBvGque, 232.Levy, A. G., 179.Lewis, W. C. M., 20.Lewite, A, 14.Lieben. F., 68.Lifschitz, I., 142.Lipman, C. B., 222, 223, 224, 232.Lipschitz, W., 86.Lockemann, K., 96.Loew, O., 223.Lombard. R. H., 30, 31.Lugner, K., 101.Lipp, P., 122.Lowry, T. M., 102, 103.Lusk, G., 187, 192, 193.Lynde, C.J., 211.Maas, O., 40.Macallum, A. B., 201, 202.Macbeth, A. K., 146.McCleland, N. P., 8.McCollum, E. V., 197, 200.Macdonald, J. L. A., 68, 72.McGuigan, H., 203.JlcIntosh, D., 40.MacIntyre, W. H., 213.Mackay, G. M. J., 40.McKenzie, A., 78, 79, 105, 106.Mackenzie, J. E., 73.McLean, F. C., 174.McLennan, J. C., 3.McLennan, K., 213, 220.Magidson, 0. J., 118.Maillard, L. C., 87.Majima, R., 102.Mallison, H., 157, 158.Malpeaux, L., 232.Alannich, C., 94.Marcelin, R., 10, 11Marine, D., 207.Marsh, J. E., 253.Marshall, J., 97.Martin, G. H., 106.Martin, K., 123, 157.Mary, A., 167.Masoni, G., 231.Mathers, F. C., 173.Maxwell, L. A. I., 205.MazB, P., 231.Mazzucchelli, A., 44, 178.Mleans, J.H., 190.Meldola, R., 91.Meloche, C. C., 54.Mendel, L. B., 196, XI, 202.Menaies, A. W. C.. 30.Merck, E., 162, 163.Merton, T. R., 23, 28.Meston, L. A., 182, 183.Meyer, H., 142.Meyer, K. H., 91, 103.Meyer, R., 66.Meyer, R. J., 29.Mieg, W., 157, 158.Miles, F. D., 174.Millard, E. B., 17.Minnig, H. D., 176.Mitchell, A. D., 8.Mockeridge, F. A., Z3.Molinari, E., 88.Momber, F., 66.Monier-Williams, G. W., 182.Monti, L., 153.Moorhouse, V. H., 198.Morgan, G. T., 114, 123.Morse, M., 2W.Mottram, V. H., 200.Miiller, E., 84, 132IKDEX OF AUTHORS' NAMES. 263Muller, J. H., 30.Muller, W., 164.Murlin, J. R., 190.Murray, W. J., 89.3Iylius, F., 178.Kametkin, S. S., 121.Nazarov, A. V., 26.Neogi, P., 74.Keuberg, C., 67.Xeumann, R., 203.Newberg, E., 18.Kierenstein, M., 95.Kiggemann, H., 5.Nishikawa, S., 239,Xitzberg, C., 166.Xoga, E., 165.Solan, T.J., 156, 157.Kordeiisen, H., 13.Korthall-Laurie, D., 181.Nottebohm, W., 46.Nowak, H., 102.Noyes, W. A., 88, 149.Ochs, R., 111.Oddo, B., 138.Oddo, G., 30.Oksman, M., 9.Otiveri-Mandala, E., 133.0 Neill, (Miss) P., 154.Onnes, H. K., 31.Orton, K. J. P., 92.Osborne, N. S., 32.Osborne, T. B., 196, 201,Palmer, W. W., 190.Panzer, T., 76.Parker, H. O., 72.Paschalski, C., 119.Patterson, S. W., 198.Patterson, T. S., 82.Pauly, H., 96, 109, 206.Peacock, D. H., 68.Pearl, R., 205.Peet, M. M., 208.Perkin, A. G., 154.Pfeiffer, P., 108.Pfeiffer, T., 213.Phelps, E. B., 173.Philip, J.C., 17.Philippi, E., 85.Piccard, J., 149.Pieroni, A., 124.Piloty, O., 169, 170.Pisani, F., 183.Pive, A., 52.Pohl, P., 154.Polack, W. G., 51.Pollak, J., 94.PoIlock, E. F., 82.Polonovski, M., 165, 166.Pontio, M., 184.Pope, W. J., 253, 255.202.'orcher, 163.'orter, J. W., 114.'osnjak, E., 175.'otter, R. S., 88, 149, 185.)owell, A. R., 229.'owis, F., 13, 14, 18.'reissecker , F., 98.'rice, W. B., 175, 177.?riess, O., 48, 50.'rigge, L., 107.'ringsheini, H., 76.'ummerer, R., 112, 113.Iurvis, J. E., 5.Puschin, X. A, 9.F'yman, F. L., 124, 160.Juensell, E., 226.Juinn, E. L., 30.Raalte, A. van, 182.Rabe, J. M., 208.Ltaffo, M., 140.Ramstedt, (Miss) E., 19.Rankin, G. A., 243.Rau, 2.Reddelien, G., 99.Reed, H.S., 222.Reich, S., 79.Reicher, L. T., 182.Reiman, C. K., 20.Reinders, W., 52, 53.Remmert, P . , 118.Remy, H., 16.Rennert, H., 94.Renshaw, R. R., 69.Reverdin, F., 90.Reverdy, A., 113.Rewald, B., 67.Rice, F. O., 6.Richards, T. W., 27, 28.Riesenfeld, E. H., 46.Riiber, C. N., 107.Rinne, F., 248.Ritter, W., 142.Rixon, F. W., 99.Robert, T., 230.Robertson, P. W., 180.Robinson, (Mrs.) G. hi., 118.Robinson, R., 90.Robinson, R. H., 186.Boche, J. W., 20, 273.Roeder, G., 126.Rordam, H. N. K., 149.Rogers, J., 208.Rona, (Misa) E., 11.Roper, H. S., 174.Rosanov, N. A., 65, 119.Rosenbloom, J., 202.Rosenheim, A., 58, 131.Rossi, G., 140.Rossteutscher, F., 95.Rothera, A. C.H . , 205.Rubin, O., 67264 INDEX OF AUTHORS’ SAMES.Iiiigheimer, L., 104.l-tuhemann, S., 92.Rup ersberg, J., 94.:Rus%y, H. H., 230.Rushenceva, (Mlle.) A. K., 121.Russell, E. J., 214, 221.Ryan, H., 150, 154.Sachs, W. H., WO.Salarnon, M. S., 183.Sander, A., 60.Sander, W., 122.Sanderson, J. C., 231.Sawyer, G. C., 186.Sayre, L. E., 165.Schaarschmidt, A,, 96.Schiifer, (Sir) E. A., 205.Schaefer, H. H., 165.Schaefer, K., 5.Scheiber, J., 104.Schidrowitz, P., 184.Schlenk, W., 55, 110, 111.Schmidt, A. A., 98.Schmidt, W., 95.Schmoeger, 233.Schonilies, A., 241.Scholer, K., 32.Scholtz, M., 85, 165.Schoorl, N., 182.Schucht, H., 15.Schiitz, G., 183.Schulze, B., 230, 231.Schwaebel, G., 160.Scott, J., 202.Scott, K.M., 202.Seaber, W. M., 183.Sears, G. W., 29.Seeliger, R., 5.Self, P. A. W., 180.Senderens, J. B., 69.Senter, G., 80.Sernagiotto, E., 123.Sharp, L. T., 222.Shaw-Mackenzie, J. -4., 203.Shorey, E. C., 219.Shutt, F. T., 211.Sidgwick, N. V., 250.Siegmund, W., 69.Simonis, H., 118.Simpson, S., 204, 207.Skinner, J. J., 228.Sloan, L. H., 203.Slyke, D. D. van, 174, 196.Smiles, S., 136.Smit, M. J., 9.Smith, A., 30, 31.Smith, E. F., 30.Snethlage. H. C . S., 21.Snyder, R. S., 185.Somogyi, R., 172.Sonn, A., 85.Sosman. R. B., 249.Soutar, C. W., 68.Spgth, E., 67, 98.Spencer, J. F., 54.Spenner, E., 85.Speyer, E., 163.Spratt, E. R., 227.Stark, J., 1, 2, 4, 5.Starling, W. W., 144.Stavraki, V., 203.Steele, (Miss) E.S., 78, 73.Steele, V., 102, 103.Steinkopf, W., 64, 135.Stephens, H., 123.Stephenson, M., 198.Stevenson, A. E., 165.Stewart, C. O., 173.Stewart, 0. J., 28.Stiles, W., 227.Still, C. J., 106.Stock, A,, 48, 50, 51.Stock, J., 169.Stoermer, R., 107, 108, 131.Strecker, W., 124.Strutt, (Hon.) R. J., 3, 4, 23, 33.Stutterheim, G. A., 182.Suida, W., 69.Surface, F. M., 205.Sutton, T. C., 11.Svedberg, T., 15.Swidzinski, K. von, 108.Tadorkoro, T., 211.Tahara, J., 102.Tartar, H. V., 186.Taylor, C. A., 180.Taglor, H. S., 19.Terentkev, A., 140.Thiele, E., 94.Thin, R. G., 177.Thomas, A. W., 76.Thorpe, J. F., 92, 109.Thorwaldson, T., 27.Tian, A., 25.Tiffeneau, M., 120, 163.Tottingham, W. E., 231.Toulaikoff, N.M., 217.Traube, I., 172.Treppmann, -W., 121.Triantaphyllides, T., 58.Troger, J., 164.Tronov, B. V., 138, 140.Truog, E., 212, 228.Tryhorn, F. G., 6, 7.Tschelincev, V. V., 137, 138, 140.Tschitschibabin, A. E., 64, 65. 111, 118.Turner, E. E., 93, 94, 99.Turner, W. E. S., 9.Tutt,on, A. E. H., 254.141, 142.Umeda, N., 204.Upson, F. IV., 229ISDEX OF AUTHORS’ NAMES. 263Vaskio, Y., 83.Vaubel, W., 185.Vecchiotti, L., 160.Venus, (Mlle.) E., 147.Vinograd, M., 196.Voelcker, J. A., 231, 232.Voht, G., 108.Voskresenski, B. I., 138.VotoEek, E., 89.Wagner, R., 227.Wakeman, A. J., 202.Waliaschko, N. A., 5.Walker, (Miss) N., 79.Walpole, G. S., 209.Walters, E. H., 219.Walton, J. H., 222.Washburn, E. W., 17.Watson, E. R., 154.Wedekind, E., 81, 108.Weerman, R. A., 74.Weichselfelder, T., 55.Wein, L., 183.Weinheber, M., 29.Weir, W., 210.Weis, F., 222.Weiss, R., 123, 130.Weizmann, C., 96, 123.Welsbach, C. A. von, 29.Welsh, T. W. B., 55.Wendt, G., 2, 4.Wenzel, F., 97.Wereide, T., 12.Werner, A., 251.Werner, E. A., 85.Wesson, L. G., 184.Wheeler, -4. S., 104.White, G. N., 151.Whiting, A. L., 227.Widdows, (Miss) 1. T., 79, 105.Wieland, H., 113.Wienerberger, A., 94.Wienerth, E., 185.Wilks, W. A. R., 182.Will, H., 170.Williams, B., 222.Willing, A., 124.Willis, L. G., 213.Willson, F., 91.Willstatter, R., 104, 156, 157, 158, 166.Wilschke, A., 166.Wilson, A., 221.Wilson, F. J., 108.Windaus, A., 164.Wislicenus, W., 118.Wissmuller, M., 53.Witt, 0. N., 91, 96.Wohl, A., 66.Wohlgemuth, H., 143.Wolf, C. G. L., 193.Wolf, L., 57.Wolff, s., 37.Wood, R. W., 4.Wren, H., 106.Wright, F. E., 243.Wuorinen, J., 29.Zalkind, J., 98.Zeide, O., 141.Zeitschel, O., 123.ZemplBn, G., 72.Zincke, T., 94.Zollinger, E. H., i57.Zuccari, G., 175.Zwicky, E., 166

ISSN:0365-6217    

DOI:10.1039/AR9151200259

出版商:RSC    

年代:1915

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Absorption spectra. See Spectra, ab-AcenapIt hylene, 119.Acids, racemisation of, 105.aliphatic, 77.Acidity, estimation of, 172.of soils, estimation of, 213.Aconitine, 164.Adsorption, reversed, 15.Aeration of soils, 214.*4%nity, residual, measurement of,A ricultural analysis, 185.Akohols, 66Aldehydes, ks.Alkali metal carbonates, compounds ofhydrogen peroxide and, 51.Alkaline earth metals, peroxides ofthe, 46.,4lkaloids, 158.Allotropy, 36.Alloys, non-ferrous, analysis of, 177.Aluminium, estimation of, 176.Amino-acids, 86.Ammonia, estimation of, in soils, 185.Ammono-compounds, 56.Analysis, . agricultural, 185.sor tion.with tetranitromethane, 146.inorganic, 173.organic, 179.physical, 171.Anthracene, 118.Antigen?, concentration of, 209.Antimony, allotropy of, 37.-4ntimony organic compounds, 127.Aroxyl radicles, 112.Arsenic, estimation of, in insecticides,Arsenic organic compounds, 124.Asymmetric synthesis, 108.Atmosphere, the, 210.Atomic structure, 1.-4zoimide and its derivatires, 133.Bacteriology of soils, 221.Basal metabolism, 188.186.weights, 27.Benzoic acid, o-thiol, reactions of, 135.Benzopyrone derivatives, 152.Bile, pigments of, 168.Bismuth, allotrop of, 36.Blood, enzymes o[ 202.Boron hydrides and haloids, 48.Bromination, 93.Bromine, estimation of, 180.pigments of, 168.uric acid in, 208.Cadmium, atomic weight of, 29.Caesium, atomic weight of, 40.Calcite group, W7.Caoutchouc, estimation of, 183.Carbamides, 84.Carbohydrates, metabolism of, 198.Carbon, atomic weight of, 27.Carbonyl bromide, formation of, 52.Catalysis, 18.Cellulose, estimation of, 182.Cerium compounds, 53.Chemical change, temperature-coeffi-cient of, 11.Chlorination, 92.Chlorine, estimation of, 180.y-chloroketones, reactions of, 143.Chlorophyll, 166.Cinnamic acids, 107.Cobalt, detection of, 173.Cocaine, detection of, 183.Colchicine, 164.Colloida,l solutions, 13.Colouring matters of plants, 155.Columbium, atomic weight of, 30.estimation of, 179.Condensation, 99.Copper, specific heat of, 31.estimation of, 175.Coupling, 115.Crystal angles, effect of temperaturestructure, X-ray method of ex-on, 248.ploring, 234.Cuprous salts, new, 43INDEX OF SUBJECTS. 267Diazo-compounds, 114.Diazonium perhaloids, 116.Diazophenols, 114.Disaccharides, 76.pr-Distearin, preparation of, 69.Disulphides, organic, 114.Dynamic isomerism, 102.Earths, rare, separation of the, 178.Electric discharge, 33.Emulsions, 13.Enan tiomorphism, 251.Enzymes, action of serum on, 202.Eserine, 165.Fats, metabolism of, 198.Felspar, play of colours in, 249.Flavone derivatives, 152.Fluorene, 118.Food, specific dynamic action of, 187.Friedel and Crafts’ reaction, 95.Galena, roastin of, 52.Gases, specific f e a t of, 32.of soil, 214.Geneserine, 165.Glucosides, 75.Glycols, ring formation from, 68.Grignard’s reaction, 97.Halogen compounds, 82.Haloids, estimation of, 173.Helium, production of, 35.Heterocyclic compounds, 129.Hormones, exogenous growth, 200.Humus, 217.Hydrates, 16.Hydraziacetic acid, derivatives of, 132.Hydrazine, reactions with, 55.Hydrazines, 113.Hydrocarbons, 64.polycyclic aromatic, 117.Hydrocyclic compounds, 119.Hydrogen, electric discharge through,active, 40.peroxide, compounds of alkali metalHydroxyl-ion concentration.measure-Hypochlorite solutions, analysis of, 174.Ice, specific heat of, 32.Indene, 117.Inorganic analysis, 173.Insecticides, estimation of arsenic in,186.Iodine, vapour pressure of, 61.blue adsorption compounds of, 144.compounds, 61.through hydrogen, 23.of blood, 202.analysis of, 183.23.carbonates and, 51.ment of, 172.Iron (ferrous), estimation of, 176.Isomerism, dynamic, 102.Isomorphism, 254.a-Ketomethyl radicles, 112.Kinetics, molecular, 10.Lead, atomic weight of, 27.allotropy of, 36.specific heat of, 31.extraction of, 52.estimation of, 174.Lead compounds, 52.Lime-sulphur wash, 47.Liquids, pure, molecular complexityLiquid mixtures,Lutecium, atomic %?iii %, 29.Manganese sulphide, modifications of,Manures, 227.Mercury, critical temperature of, 44.Mesembrine, 166.Metabolism, 187.of, 8.62.basal, 188.of carbohydrates and fats, 198.of proteins, 194.Metals, displacement of, by zinc, 45.Metaquinonoid substances, 110.Methane, tetranitro- as a reagent, 146.Methyl alcohol, detection and estima-Methylenediamine, preparation of, 82.Milk, detection and estimation of waterMinerals, thermal study of, 242.Mixtures, binary liquid, 9.Molecular complexity of pure liquids, 8.Molecules, configuration of, 15.Molybdenum, atomic weight of, 30.Morphotropy, 255.Neon, production of, 35.Nickel compounds, 57.Nitrates, estimation of, 174.Nitration, 88.Nitrogen, active, 33.estimation of, 180.Nitrogen compounds, 82.Nutrition of plants, 227.Optical activity, 77.Organic analysis, 179.Oxidation, 94.Oxonium compounds, 147.Oxymorphine, detection of, 180.Pentazole compounds, 142.Pentoses, estimation of, 186.Pertetraboric acid, 51.tion of, 181.in, 182.kinetics, 10.weights, 30268 INDEX OF SUBJECTS,Phosphorus, red, pFeparation of, 57,Phosphorus, detection of, 173.estimation of, 174.Photochemical reactions, 24.Physical analysis, 171.Pituitrin, 204.Plant nutrition, 227.Plant pigments, 155.Platinum, specific heat of, 31.analysis of, 177.Polyhydroxy-compounds, 67.Polymorphism, 250.Polysaccharides, 76.Potassium, allotropy of, 37.Potential differences in non-aqueousPraseodymium, atomic weight of, 28.Proteins, chemistry of, 194.Protein metabolism, 194.Pyridine, reactions of, 140.Pyrones, 149.Pyrophosphoric acid, constitution of,Pyrrole group, 137.Racemisation of acids, 105.Radicles, organic, 110.S-Radiograms, 240.Rain-water, analysis of, 210.Reactions, photochemical, 24.Reduction, 93.Rubber goods, estimation of caoutchoucSalicylic acid, detection of, 179.Schiff’s bases, 99.Secretions, internal, 204.Selenium, sensitive form of, 59.Selenium. organic compounds, 123.Sempervirine, 165.Serum, action of, on enzymes, 202.Silicate fusions, differentiation in, 248.Silver, new crystalline variety of, 38.Sodium, allotropy of, 37.Soils, 211.estimation of, 177,media, 17.58.in, 184.detection of, 173.borates, new, 44.partial sterilisation of , 219.bacteriology of , 221.estimation of ammonia in.185.Soil aciditv, estimation of, 213.Soil gases,. 214.Soret’s phenomenon, 12.Specific heats, 31.Spectra, absorption, 5.Spinel group, W8.Spiro-compounds, 109.Starch, potato, estimation of, inbread, 183.Stereoisomerism, 105.Steric influence, 98.Stilbene compounds, 107.Struxine, 165.Sugars, 70.Sulphites, absorptive power of, 59.I Sulphonation, 91. I Sul hur, atomic weight of, 28.~ agotropy of, 37.Surface Law, the, 187.~ Synthesis, asymmetric, 108.Tantalum, atomic weight of, 29.Temperature-coefficient of chemicalTernary system#, 243, 247.Terpenes, 119.Tetrathionates, preparation of, 60.Thiophen group, 134.Tin, atomic wei ht of, 29.Tobacco, Turkist, alkaloids in, 165.Toluene, estimation of,. 180.Transport numbers in non-aqueousTriamtin, reparation of, 69.Triarylmet yl, 110.Uranium, atomic weight of, 28.Uric acid in blood, 208.Valency, 38.Valency-volume theory, the, 21.Vanadium, estimation of, 178.Vapours, metallic, spectra of, 3.Vitamines, 200.Walden inversion, the, 78.Weights, atomic. See Atomic weights.Yohimbine, 163.Zinc, electrolytic deposition of, 44.displacement of metals by, 45.commercial, analysis of, 177.peroxide, 47.line, 1.of metallic vapours, 3.Ichange, 11.media, 17.i Yttrium, atomic weight of, 29.PRINTED IN GREAT BRITAIN DY R. CLAY AND SONS LTD..BRUNSWICS STREET, STAMFORD STREET. S.E.. AND BUNGAY, SUFFOLK

ISSN:0365-6217    

DOI:10.1039/AR9151200266

出版商:RSC    

年代:1915

数据来源: RSC