摘要:

ANNUAL REPORTSPROGRESS O F CHEMISTRY.ON TEANNUAL REPORTSON THEPROGRESS OF CHEMISTRYF O R 1 9 1 2 .ISSUED BY THE CHEMICAL SOCIETY.Qommiftee o f @irbIiratioir :H. BHERETON BAKER, M.A., D.Sc.,HORACE T. BROWN, LL. D., F.R.S.J. N. COLLIE, Ph.D., F.R.S.A. W. CROSSLEY, D.Sc., Ph.D., F.R.S.F. G. DOSNAN, M.A., Ph.D., F.R.S.BEENARD DYER, D.Sc.F. R. S.M. 0. FORSTER, D.Sc., Ph.D., F.R.S.P. F. FRANRLAND, Ph. D., LL. D., F. R.S.C. E. GROVES, F.R.S.A. MCKENZIE, M.A., D.Sc., P1l.D.J. C. PHILIP, D.Sc., Ph.D.A. SCOTT, M.A., D.Sc., F.R.S.S. SMILES, D.Sc.@l;bifar :J. C. CAIN, D.Sc., Ph.D.Silub-@bifox :A. J. GREENAWAY.E. C. C. BALY, F.R.S.A. D. HALL, M.A., F.R.S.W. D. HALLIBURTON, M.D., F.R.S.A. HUTCHINSON, M.A., Ph.D.G. CECIL JONES, F.I.C.R. H. LE SUEUR, D.Sc.K. J. P. ORTOX, M.A., Ph.D.G. SENTER, D.Sc., Ph.D.I!. SODDY, M.A., F.R.S.A. W. STEWART, D.Sc.V O l . IX.LONDON:GURNEY & JACKSON, 33, PATERNOSTEH ROW, E.C.1913RICHAED CLAY & SONS, LIMITED,BRUNYWICK STREET, STAXFORD STREET, S.E. ANDBUNOAY, SUFFOLKCONTENTS.PAG Ir.GENERAL AND PHYSICAL CHEMISTRY. By G. SENTEI:, D.Sc., Ph.D. 1INORGANIC CHEBIISTRY. By E. C. C. BALY, F.R.S. . . . . 36Part 1.-ALIPHATIC DIVISION. By H. R. LE SUEIJR, D.Sc. . . . 73Part II.-HOMOCYCLIC DIVISION. By K. J. P. ORTON, M.A., P1i.D. , 112STEWART, D.Sc. . . . . . . . . . . . 154ANALYTICAL CHEMISTRY. By G. CECIL JONES, F.I.C. . . . 193PHYSIOLOGICAL CHEMISTRY. By W. D. HALLIBURTON, M. D., F. R. S. 221AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY.By A.D. HALL, M.A., F.R.S. . . . . . . . . 242MINERALOGICAL CHEMISTRY. By ARTHUR HUTCHINSON, M. A., Ph.D. 255RADIOACTIVITY. By FREDERICK SODDP, JLA., F.R. S. . . . 289ORGANIC CHEMISTRY : -Part 111. -HETEROCYCLIC DIVISION AND STEREOCHEMISTRY. By A. JjrTABLE OF ABBREVIATIONS EMPLOYED I N THEABBREVL4Tgb TITLE.A . . . . . .Amer. Chem. J . . . .Amer. J. Physiol . .Bmer. J. Sci. . . .Anal. Fis. Quim. . .Analyst . . . .Annalen . . . .Ann. Chiin. a.nal. . .Ann. Physik . . .Ann. Report . . .Ann. sci. Univ. Jassy .Arch. expt. Path. Pharm. .Arch. Pharm. . . .Arkiv Kem. Nin. Geol. .Atti X. A c d . Lincei ,Ber. . . . . .Bio-Chem. J. . . .Biochem. Zeitsch. . .Bull. Acad. Sci. Cracow .Bull. A&.Sci., St. Pkters-bourg . . . .Bull. SOC. chim. . .Bull. SOC. chim. Belg. .Bull. Soc. franq. Min. .Centr. Bakt. Par. . .Centr. Nin. . . .Chem. NEWS . . .Chein. Weekblad . .Chem. Zeit. . . .Chm. Zentr. . . .Compt. rend. . . .Fold. Kozltiny . , .Gazzetta . . . .Gummi-Zeit. . . .Intern. Sugar J. . .Jahrb. Min. . . .Jahrb. Min. Beil-Bd.Jahrb. Radioaktiv. Eleklro-nik. . . . .REFERENCES.JOURNAL.Abstracts in Journal of the Chemical Society. *American Chemical Journal.American Journal of Physiology.American Journal of Science.Anales de la Sociedad Espafiola Fisica y Quimica.The Analyst.Justus Liebig’s Annalen der Chemie.Annales de Chiniie analytique appliqn8eAnualen der Physik.Annual Reports of the Chemical Society.Annales scientifiques de l’Universit6 de JassyArchiv.fur experimentelle Pathologie und Pharmako-Archiv der Pharmazie.Arkiv for Kemi, Mineralogi och Geologi.Atti della Reale Accademia dei Lincei.Berichte der Deutschen chemischen GesellschaftThe Bio-Chemical Journal.Biochemische Zeitschrift.Bulletin international de 1’Acadimie des Sciences doBulletin de l’Academie ImpBriale des Sciences doBulletin de la Societd chimique de France.Bulletin de la Socigtd chimique de Belgi ue.Bulletin de la SocidtB franpaise de MinBrJogie.Centralblatt fur Bakteriologie, Parasitenkunde undInfektionskrankheiten.Centralblatt fur Mineralogie, Geologie und Palaeonto-logie.Chemical News.Chemisch Weekblad.Chemiker Zeitung.Chemisches Zentralblatt.Comptes rendus hebdomadaires des SQances deFoldtani Kozlony.Gazzetta chimica italiana.Gumnii-Zeitung.International Sugar Journal.Neues Jahrbucli fur Mineralogie, Geologie undNeues Jahrbuch fur Mineralogie, Geologie undJahrbuch der Radioaktivitat und Elektronik.l’hdustrie,?i l’Agriculture, B la Pharmacie et B la Riologie.logie.Cracovie.St.PQtersbourg.1’AcadQmie des Sciences.Palaeontologie.Palaeontologie. Beilage-Band.The year is not inserted in references to 1912viii TABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES.ABBREVIATED TITLE.J. Agric. Sci. . . .J. A m r . Chem. Soc. . .J. Biol. Chem. . . .J. Chim. Phys. . . .J. Ind. Eng. Chem. . .J . Inst. Brewing . .J L a n d W . . . . .J. Pharm. Chim. . .J.Physical Chem. . .J. Physiol. . . .J. Physique . . .J. pr. Chem. . . .J. Buss. Phys. Chem. Soc. .J. Soc. Chem. Ind. . .J . Washington Acud. Sci. .Landw. Jahrb. . . .Landw. Verszcchs-Stat. .Hin. Mag. . . . .Monatsh.. . . .PJliiger's Archizr . . .Pham. Weekblad . .Phil. Mag. . . .Phil. Trans. . . .Philippine J. f c i . . .Physikal. Zeitsch. . .P . . . . . .Proc. Amer. Acud. . .Proc. Camb. Phil. Soc. .Proc. K. Akad. Wetansch.Proc. London Phys. SOC. .Proc. Phygwl. Soc. . .Proc. Roy. Soc. Edin. .Rec. trav. chim. . . .Amsterdam.Proc. Roy. s'oc. . . .X e d . Accad. Sci. Fk. Mat.Napoli . . . .&a. Mdt. . . . .Sitzungsber. K. Akad. Wiss.Berlin.T. . . . . .Tech. Quart. . . .Trans. Amer. Electrochem.xoc.. , . .Trans. Faraduy SOC. . .Y'rans. Roy. SOC. Canadn .Tsch. Min. Matt. . .Yerh, Ges. deut. Natcirforsch.Wochensch. f. Bmucrei .Zeitsch. anal. Chem. . .Zeitsch. angew. Chem. .Zeitsch. a w g . Chenh. . .Zeitsch. Biol. . , .AerzteJOURNAL.Journal of Agricultural Science.Journal of the American Chemical Society.Journal of Biological Chemistry, New York.Journal de Chimie physique.Journal of Industrial and Engineering Chemistry.Journal of the Institute of Brewing.Journal fur Landwirtschaft.Journal de Pharmacie e t de Chimie.Journal of Physical Chemistry.Journal of Physiology.Journal de Physique.Journal fur praktische Chemie.Journal of the Physical and Chemical Society ofJournal of the Society of Chemical Industry.Journal of the Washington Academy of Sciences.J,andwirtschaftliche Jahrbiicher.Die landwirtschaftlichen Versuchs-Stationen.Mineralogical Magazine and Journal of the Mineral-Monatshefte fur Chemie und verwandte Theile andererArchiv fur die gesammte Physiologie des Menschenund der Thiere.Pharmaceutisch Weekblnd.Russia.ogical Society.Wissenschaften.Philosophical Magazine (The London, Edinburgh andDublin).Philosophical Transactions of the Royal Society ofPhilippine Journal of Science.Physikalische Zeitschrift.Proceedings of the Chemical Society.Proceedings of the American Academy.Proceedings of the Cambridge Philosophical Society.Xoninklijke Akademie van Wetenschappen te Amster-Proceedings of the London Physical Society.Proceedings of the Physiological Society.Proceedings of the Royal Society.Proceedings of the Royal Society of Edinburgh.Raceuil des travaux chimiques des Pays-Bas et de laRendiconto dell' Accademia delle Sienze Fisiche eRevue de Mdtallurgie.8i tzungsberichte der Koniglich Preussischen AkademieTransactions of the Chemical Society.Technology Quarterly.Transactions of the American Electrochemical Society.Transactions of the Faraday Society.Transactions of the Royal Society of Canada.Tschermak'x Mineralogische Mitteilungen.Verhandlung der Gesellschaft deutscher NaturforscherWochenschrift fur Brauerei.Zeitschrift fur analytische Chemie.Zeitschrift fur angewandte Chemie.Zeitschrift fur anorganische Chemie.Zeitschrift fur Biologie.London.dam.Proceedings (English version).Belgi'que.Matematiche-Napoli.der Wissenschaften zu Berlin.und AerztTABLE OF ABBREVIATIONS EMPLOYED IN THE REFERENCES. ixABBREVIATED TITLE.Zeitsch. Chena. Ind. Kolloide.Zeitsch. Blektroeheem. . .Zeitsch. Farb. Id. . .Zuitseh. Kryst. Min. . .Zeitsch. Nahr. Genussm .Zeitsch. physikal. Chem. .Zeitsch. physiol. Ohem#. .Zeitsch. Ver. deut. Zwkerind.JOURNAL.Zeitschrift fur Chemie uud Iiidnstrie der Kolloide.Zeitschrift fur Elektrochemie.Zeitschrift fur Farbenindustrie.Zeitschrift fur Krystallographie und Mineralogie.Zeitschrift fur Untersuchung der Nahrungs- undZeitschrift fur physikalische Chemie, StochiometrieHoppe-Seyler's Zeitschrift fiir physiologische Chemie.Zeitschrift desVereins der deutschen Zucker- Industric.Genussmittel.und VerwandtschaftslehreANNUAL REPORTSPROGRESS O F CHEMISTRY.ON TH

ISSN:0365-6217    

DOI:10.1039/AR91209FP001

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

INORGANIC CHEMISTRY.ALTHOUGH perhaps the work carried out during the past year doesnot include any great and far-reaching discovery, yet it may atonce be said that a very large number of papers have beenpublished, many of which are of considerable interest and value.A great difficulty must naturally be felt in presenting a report oninorganic chemistry arising from the fundamental importance ofmany papers which perhaps may be considered more properly asbeing within the purview of physical chemistry. A few of thesewhich manifestly are of importance in relation to inorganic chem-istry have been included.I n the main the report follows in its arrangement the precedentof previous years. A section has been added on the rare earths,and as no especial reference has been made to this branch of workof late, two papers published in 1911 have been included.,4 tomic 'IVeights.During the past year a number of important papers dealing withthe determination of atomic weights have appeared.NitTogen.-Wourtzel1 has redetermined the ratio between nitro-gen and oxygen, the method involving the determination of theweight of oxygen necessary to convert a known weight of nitricoxide into nitrogen peroxide.Pive concordant experiments gave amean value for the atomic weight of nitrogen as 14.0068.Potassium and Chlorine.-Reference was made in last year'sreport to an interesting redetermination of the ratio betweenpotassium and chlorine which was based on a careful analysis ofpotassium chlorate, very great precautions being taken againstcontamination of the salt by the chloride.The final series ofresults gives the atomic weight of potassium as 39.097 and of chlorineas 35-458.2 These results have been favourably criticised by Guye,3Concpt. rend., 1912, 154, 115 ; A., ii, 248.Stahlcr mid Meyer, Zeitsch. nnorg. Chem., 1911, 71, 368 ; A., 1911, ii, 881.J. Chwn. Phys., 1912, 10, 145 ; A., ii, 552.3INORGANIC CHEMISTRY. 37who concludes that the amount of potassium chloride present inthe chlorate was a t least sufficiently eliminated to be practicallynegligible.Since the Report of the International Committee on AtoxicWeights has appeared, two papers have been published dealing withthe atomic weight of chlorine. I n one of these Wourtzel4 deter-mines the nitrogen-chlorine ratio by the formation of nitrosylchloride from nitric oxide and chlorine.As a mean of five resultsthe atomic weight of chlorine was found to be 35*460+0.003(N = 14.008).Baume and Perrot5 also determined the ration of chlorine tonitrogen from the combination of gaseous hydrogen chloride with aknown quantity of liquid ammonia, and the value found for chlorinewas 35.465 (N= 14.009).Burt and Whytlaw-Gray 6 have redetermined the density ofhydrogen chloride. The gas was absorbed by charcoal, care beingtaken to remove all mercury vapour by condensation with solidcarbon dioxide. The weight of a litre of the gas was found to be1.63915 & 0.00004, which is identical with the previously foundvalue.Bromine.-An important paper has appeared by Weber 7 describ-ing his experiments to determine the ratio between hydrogen andbromine.As a mean of ten experiments, Weber found the atomicweight of bromine to be 79.924.Fluorine.-McAdam and Smith,* as a result of experiments onthe conversion of sodium chloride into sodium fluoride, have pub-lished two preliminary determinations of the atomic weight offluorine, which are 19.0176 and 19.0133 respectively.Phosphorus.-Baxter, Moore, and Boylston 9 carried out theanalysis of phosphorus tribromide, and found as a mean of threeseries of experiments the atomic weight of phosphorus to be 31.027(Ag= 107'88).Baxter and Moore,l0 from the analysis of phosphorus trichloride,have found, as the mean of their most trustworthy experiments,the atomic weight of phosphorus to be 31.028.Mercury .-From an analysis of mercuric bromide Easley andBrannl' have confirmed the atomic weight of mercury as 200.64,This gives the atomic weight of chlorine as 35.460.C'ompt.rend., 1912, 155, 345 ; A., ii, 931.Ibid., 461 ; A,, ii, 933.Tyans. Fccia&ay SOS'~~., 1911, 7, 30 ; A., ii, 152.7 J. Amel.. Chm. SOC., 1912, 34, 1294 ; A., ii, 1162.8 ]bid., 592 ; A., ii, 549.Ibid., 259 ; A . , ii, 347.lo Ibid., 1644 ; A., 1913, ii, 43.l1 Ibid., 137 ; A., ii, 25738 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.a value agreeing with that previously found by Easley in his workon the chloride.Tellurium.-As was mentioned in last year’s report, Harcourtand Baker have thrown doubt on the work of Flint, in which thelatter claimed to have resolved tellurium into two fractions havingdifferent atomic weights.Pellini 12 has also come to a similar con-clusion. On the other hand, Flint13 has published a further paperon the subject, in which he points out that the explanation of thelower atomic weight put forward by Harcourt and Baker, namely,the presence of tellurium trioxide, is not sound. Flint gives it as hisopinion that the matter has not yet, been settled, and promises afurther paper on the subject.Dudley and Jones l4 have carried out spectrographic investiga-tions which are important in the present connexion. They findthat there is no variation in the spectrum of the different fractionsof tellurium, which indicates that no resolution of tellurium hastaken place under the conditions of fractionation.Further work ispromised in this direction.Flint’s work has been repeated by W. C. Morgan15 with largeramounts of material, and although twice as many fractionationswere carried out, no evidence of separation was obtained.Holmium.-Holmberg 16 has carried out determinations on theatomic weight of holmium by means of the sulphate method, andfinds, as a mcan of six determinations, the atomic weight to be163.45. I n the International Table of Atomic Weights for 1913this number has heen adopted.Radium-Two interesting papers on the atomic weight ofradium have appeared during the past year. I n one, Honigschmid 17found from the analysis of a large quantity of radium chloride theatomic weight of radium to be 225.95.I n the other, Whytlaw-Grayand Ramsay,18 by the conversion of small quantities of radiumbromide into chloride, found the atomic weight to be 226’36, aresult which is in agreement with the well known value of Mme.Curie and of Thorpe.Palladium.-Shinn 19 has carried out a series of determinationsof the atomic weight of palladium, the method used being thereduction of the double chloride of ammonium and palladium byP2IS141 J1617IS19Atli R. Accad. Lincei, 1912, [v], 21, i, 218 ; A,, ii, 343.J. Amer. Chem. Soc., 1912, 34, 1325 ; A., ii, 1051.Zbid., 995 ; A . , ii, 9351Ibid., 1669 ; A . , 1913, ii, 41.Arkiv Kern. Min. Geol., 1911, 4, No. 10; A., ii, 163.Momlsh., 1912, 33, 253 ; A , , ii, 523.Proc.Roy. Soc., 1912, A, 86, 270 ; A., ii, 413.J. Amer. Chm. Soc., 1912, 34, 1448; A., ii, 1178INORGANIC CHEMISTRY. 39formic acid in the presence of ammonia. As a mean of nine deter-minations the atomic weight was found to be 106.709 +_ 0.016.Uranium.-Lebeau 20 has carried out the reduction of uranylnitrate dihydrate to uranium oxide by heating the salt in a currentof hydrogen a t l l O O o , and as a mean of five experiments he obtainedthe value 238.50, thus confirming the previous value obtained.Iron.-Baxter and Hoover,21 by the reduction of ferric oxide inhydrogen, find the atomic weight of iron t o be 55.847 as a mean oftwelve analyses.Molecular Weights.RBy, Dhar, and De22 have determined the vapour density ofammonium nitrite.A weighed quantity of the salt, previouslysublimed in a vacuum, is introduced into a Hofmann tube heatedto 78O with alcohol vapour. Part of the salt decomposes intonitrogen anci water, and part into ammonium nitrate, ammonia,nitric oxide, and water, according to the equation :3NH,NO, = NH,N03 + 2N0 + 2NH3 + R20,whilst the remainder exists in the form of undecomposed vapour.The products of decomposition were estimated, and the amount ofammonium nitrite used up in their formation was calculated, Thisamount deducted from the original quantity gave the amount exist-ing in the form of vapour, and thus, as the volume of the vapour wasknown, the vapour density could be arrived at. The mean oftwenty determinations gave a vapour density of 33.5, the theoreti-cal value being 32.0.The authors point out that the presence orabsence of water made little or no difference.Ramsay23 has determined the ratio of the specific heats of neon,krypton, and xenon by comparing the wave-length of sound in thegas with that of air. He found the values as follows: Ne=1*642,Kr = 1.689, Xe= 1.666. These numbers approximate within thelimits of experimental error to the theoretical ratio 1.667, and i ttherefore follows that these three gases, like helium and argon,,must be regarded as monatomic. The molecular and atomic weightsmust be identical.Preuner and Brockmoller,2* having devised a spiral manometermade of quartz for the accurate measurement of gas pressures,determined the isothermals of sulphur, selenium, arsenic, and phos-phorus, from which they calculated the molecular weight and theCompt.Tend., 1912, 155, 163 ; A , , ii, 848.21 J. Amer. Chem. SOC., 1912, 34t, 1667; A . , 1913, ii, 55.2.2 T., 1912, 101, 1185.24 Zeitsch. physikal. Chem., 1912, 81, 129 ; A,, ii, 1145.Proc. Boy. Soc., 1912, A, 86, 100; A., ii, 25140 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY.dissociation of the vapours of these substances. They determinedthe isothermals of selenium a t 550°, 600°, 650°, 700°, 750°, and800°, and found that the equilibrium Se, 2 3Se2 takes place overthis region. A t low and high temperatures there is some evidenceof Se, and Se atoms respectively. I n the case of sulphur vapour,S,, S,, S2, and S are present in amounts depending on the conditionsof temperature and pressure.The isothermals of phosphorus andarsenic were measured a t 800°, 900°, 1000°, l l O O o , and 1200°, andfrom these curves the authors find that tetra-atomic and diatomicmolecules as well as single atoms are present.The density of phosphorus vapour has been determined withgreat accuracy by Stock, Gibson, and Stamm25 with Gibson’s mem-brane manometer.26 The investigations extended over a tempera-ture range of 500° to 1200°, and the first conclusion arrivedat is that phosphorus vapour obeys Boyle’s and Gay-Lussac’s lawsbetween 500° and 700° and 240 and 300 mm. pressure, and thati t consists entireIy of P, molecules. A t higher temperatures disso-ciation into P, sets in, especially at lower pressures. The maximumdegree of dissociation observed (twethirds of the P, having disso-ciated) was a t 1200°, and at a pressure of 175 mm.The authorsprove that the only equilibrium concerned is P, 2P2. Theyalso calculated that a t the temperature of 1300O the amount ofdissociation would be 60 per cent. a t 760 mm. and 89 per cent.at 100 mm. pressure.These results differ from those of Preuner and Brockmollermentioned above, and the authors criticise those results whichwould seem to point to there being some phosphorus atoms presenta t the higher temperatures. They point out that whereas they usedcarefully purified red phosphorus, Preuner and Brockmoller usedcommercial yellow phosphorus, which they merely washed severaltimes.Pal enc y.Some interesting experiments have been carried out by Ephraim 27on the hexammine compounds of certain metals, with the view ofobtaining a quantitative measurement of the auxiliary valencies inthese compounds.Ephraim points out that as these compoundsare formed by virtue of the secondary valencies of the principalmetallic atom in the molecule it should be possible to determinethe relative strength of these auxiliary valencies by measuring thedissociation pressure of the hexammine compounds. The author25 Ber., 1912, 45, 3527 ; A., 1913, ii, 43.2G To be described later.3 Bcr,, 1912, 45, 1322 ; A , , ii, 546INORGANIC CHEMISTRY. 41considers that if the pressure is kept constant the temperature a twhich the decomposition occurs will be a measure of the energy ofthe auxiliary valencies because the decomposition of the molecularcomplexes must be dependent on three factors, namely, the pressure,temperature, and affinities of the constituents.I n one series of experiments he finds that the temperature a twhich the dissociation pressure of the hexammine chlorides ofglucinum, nickel, cobalt, iron, copper, manganese, zinc, cadmium,and magnesium is equal to 500 mm.decreases as the atomicvolime of the metal increases. I n other words, the auxiliaryvalency of the metal is a function of its atomic volume. As Ephraimpoints out, the atomic volume is not the only factor, because copperand iron, which have the same atomic volume, have not the sameaffinity towards ammonia. The dissociation pressures of thehexammine compounds of these two metals are similar, but notidentical.The stability of the hexammine compounds alsodecreases with increase of atomic volume, and i t is an interestingfact that no single metal with an atomic volume greater than 14can form a hexammine derivative which is stable a t the ordinarytemperature. Similarly, in the case of glucinum, the atomic volumeof which is 5.26, the hexammine derivative is so stable that itdecomposes in other ways before the temperature is sufficient togive an ammonia pressure of 500 mm.He also finds that the influence of the atomic volume is less thelarger its value, for of seven hexammine chlorides examined it wasfound that the value of $F. vg was approximately constant,where T is the absolute temperature a t which the ammonia pressureis equal t o 500 mm., and v is the atomic volume.It was also found that the acid radicle has some influence on theenergy of the auxiliary valencies; f o r example, the ratio of theabsolute temperatures a t which the dissociation pressures of nickelchloride and nickel bromide is equal to 500 mm.was 1.073, and inthe case of the chloride and bromide of cadmium this ratio was1.086. This factor Ephraim calls the tension-modulus, and taking1-08 as the mean of the above two values he calculates the dissocia-tion pressure of the hexammine bromide of cadmium from theexperimentally found value for the chloride. The value obtainedis 349.3, whilst the experimental value is 347.5, which is quitewithin the limits of experimental error.I n exactly the same waythe values of the tension-moduli Br/I, Cl/I, SO,/I were measuredand found to be constant. The only exceptions were the hexamminecompounds of zinc. The constant ratio between the tension-moduliwas also found to hold good over considerable ranges of pressure;for example, the ratio for the bromide and iodide of cadmiu42 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.between the pressures of 103 and 780 mm. was found to have amean value of 1.066.This therefore appears to be a special case of Ramsay and Young'srule, and it was also found that this rule could be applied to thehexammine compounds of all the metals examined between thelimits of 200 and 700 mm. pressure. From the dissociation-pressurecurves the heat of formation, Q, was calculated from the expres-sion :T .Tz Q =L . log%.2; - Y2 p ,From the values obtained it follows that for equal dissociationpressures Q / T is very nearly constant, which corresponds withTrouton's law-.The value of the constant Q/Z' for dissociation pressures of500 mm. was found to be between 0-030 and 0.036.I n connexion with this i t is interesting to note that C'hauvenet 29found for ThC1,,18NH3 the value of &/T to be 0.032.This was previously shown by Matignon.28A llotropy.Stock, Schracler, and Stamm 30 have carried out an investigationon the transformation of yellow phosphorus into red phosphorusphotochemically. The yellow phosphorus was placed in a side-tube in an exhausted flask.By local cooling a, thin layer of yellowphosphorus was obtained on the walls of the flask, and this filmwas illuminated on the inner side by rays from a mercury lamp.The residual yellow phosphorus was removed by cooling the side-tube with liquid air for several days. It was found that the violetend of the spectrum was most active in the conversion, and thattemperature had very little influence. The density of the redphosphorus thus obtained varied from 1.95 to 2.25, the darkest incolour being tho heaviest. It is possible that some crystals werepresent.. It was also found that rapid cooling of phosphorus vapourgives red phosphorus, the amount obtained increasing with thetemperature to which the vapour was heated before being suddenlycooled.The authors conclude that the two varieties of phosphorusare chemically different, and that the red variety is formed by theunion of dissociated phosphorus particles with on0 another or withundissociated phosphorus molecules. Red phosphorus prepared inthis way is yellowish-red to blood-red in thin layers, and blackwith a violet glance in compact pieces. When ground to a powderit resembles the commercial article. I t s maximum density was2.215, and it appears to be crystalline. It is stable in air, is only2* Compt. rend., 1899, 128, 103 ; A . , 1899, ii, 273.2Q Ann. Chim. Phys., 1911, [viii], 23, 275 ; A., 1911, ii, 586.3u Ber., 1912, 45, 1514; A,, ii, 639INORGANIC CHEMISTRY. 43slowly attacked by boiling sodium hydroxide, and does not give ared solution in alcoholic potassium hydroxide solution.Hesehus21 has studied the properties of diamond, graphite, andcharcoal, and he shows that the differences between the contactelectrification of the allotropic modifications depend, not only ontheir surface density, but also on the capacity of the atoms forionic dissociation.It would seem from this result of Hesehus thatin all probability the catalytic action of the various allotropicmodifications would depend on the residual affinity.Comb us tion.Rhead and Wheeler have published papers in which they dealwith the equilibrium between carbon dioxide and carbon, and theoxidation of carbon itself. I n the first paper 32 they describe theirinvestigations into the rate of reduction of carbon dioxide bycarbon a t various temperatures.The method consisted in thecirculation for known periods of carbon dioxide over carbon heatedto different temperatures, the time taken for a complete circulationof the gas through the apparatus having been previously deter-mined. The amount of reduction of the carbon dioxide wasobtained from the increase of pressure in the apparatus. Theresults show that there is a considerable falling off in the amountof reduction taking place in a given time when the temperaturefalls below 1000°. One set of experiments was carried out with amixture containing 80 per cent. of nitrogen and 20 per cent. ofcarbon dioxide, and this has some interest from the point of viewof producer gas, because they found that owing to the short time ofcontact in the producer a temperature of more than l l O O o is necessaryfor the maximum production of carbon monoxide. The presence ofthe 80 per cent.of nitrogen causes a general retardation in the rateof reduction, and so enabled the authors to appreciate the truerelative rates a t the higher temperatures. I n the second papersthey consider the oxidation of the carbon itself. I n connexion withthe oxidation of carbon considerable evidence has been advanced,both in favour of the oxidation t o carbon monoxide and in favourof the oxidation to carbon dioxide. It is perhaps more generallyaccepted that the reaction takes place in the following way:( a ) c+o,=co,; ( b ) co,+o=2co.The work of Dixon and also that of H.B. Baker would seem tofavour the view that the carbon is oxidised first to carbon mon-oxide, as expressed by:31 J. Russ. Pliys. C h i t So,:., 1911, 43, Phys. Part, 365 ; A . , ii, 121.32 T., 1912, 101, 831.( G ) 2c 3- 0,=2CO,Ibid., 84644 ANNUAL REPOnTS ON THE PROGRESS OF CHEMISTRY.and that any carbon dioxide is due to the process:(d) 2CO + o,= 2c0,.Rhead and Wheeler point out that if the relative rates of ( a ) and(c) could be determined under conditions when the amounts of( b ) and (d) are inappreciable, the matter would be solved. Theyfind, however, that during the oxidation of the carbon at low tem-peratures neither ( a ) nor (6) takes place exclusively, and they areobliged to conclude that both carbon monoxide and carbon dioxideare simultaneouely produced by the direct oxidation of carbon.Wieland34 deals with the reaction between carbon dioxide andwater in the presence of palladium-black. He finds that the firstproduct is formic acid, which then gives carbon dioxide andhydrogen, the hydrogen being retained by the palladium. Theintermediate existence of formic acid was proved by chemicalmeans Wieland also showed that formic acid is an intermediateproduct in the hot combustion process.If a carbon monoxideflame is allowed t o play on ice, the presence of formic acid in themelted ics can readily be proved. The combustion of the hydrogenfrom the formic acid gives the water which is necessary for thecombustion t o proceed, and prevents the reversible reaction fromtaking place. Traube's view of hydrogen peroxide playing animportant part is wrong, for the hydrogen peroxide only occurs asa subsidiary product in the first stage of the combustion of thehydrogen from the formic acid.It is well known that the platinummetals catalyse the reaction :H*CO,H = E, + CO,,and in the case of palladium the catalytic influence is so greatthat the evolution of hydrogen is stronger than the absorption ofhydrogen by the palladium, with the result that hydrogen isevolved. If the palladium-black has previously been ignited, itspower as a catalyst is destroyed.F. Meyer 35 describes experiments to show that the outer zone of areversed-flame is strongly reducing, so that any substance made topass through the flame from the inside to the outside will bereduced, and remain reduced.It is necessary that the combustionproducts of the flame should be equal to one of the products formedby the reduction of the substance, for example, a chlorine-hydrogenflame must be used for the reduction of chlorides, the chlorine flameburning in a quartz jet inside hydrogen. Meyer found that thisreduces stannic chloride t o stannous chloride, arsenic chloride t oarsenious chloride, and titanium tetrachloride to titaniumtrichloride.:I4 Bcr., 1912, 45, 679; A., ii, 347.35 Ibid., 2548 ; A . , ii, 1051INORGANIC CHEMISTRY. 45rs’ulphuric Acid Munufacture.Reynolds and Taylor 315 have carried out a series of experimentswith the view of testing the theory put forward by Raschig37 of thechamber sulphuric acid process.Raschig supposes that an unstablenitrososulphonic acid is first formed by the action of sulphurdioxide on nitrous acid, as shown by the equation:and that this acid is a t once transformed by more nitrous wid intoanother unstable compound, nitrosisulphonic acid :ONS03H + €€NOz = H2NS05 + NO,and that this new acid then decomposes into sulphuric acid andnitric oxide :H,NSO,= HzS04 + NO.HNO, + SO, = ONSO,H,Raschig states that his nitrosisulphonic acid is identical with theviolet acid discovered by Sabatier.This theory was somewhat modified by Divers?* who points outthat Raschig’s nitrososulphonic acid has probably no existence, andthat the evidence is all against the existence of nityosisulphonicacid.Reynolds and Taylor confirm the conclusion of Divers thatnitrososulphonic acid has no existence, and prove by experimentthat dilute solutions of nitrous and sulphurous acids mutuallydecompose one another with evolution of nitrous oxide. They alsoconfirm Divers’ conclusion that this reaction takes place in twostages :(i) HNO,+ 2H,S0,=H2O + HON(SO,R),.(ii) HON(SO,H), 1- HNO,= 2H,S04 + N,O.According to Raschig, the nitrososulphonic acid being formed ina strong acid solution containing excess of sulphurous acid a t onceundergoes decomposition according to the second equation above.In his experiments potassium iodide was added to the solution toindicate whether excess of nitrous acid was present o r not.Reynolds and Taylor prove that the evolution of nitric oxide in theexperiment described by Raschig in support of his second equationis due to the action of nitrous acid on hydriodic acid.Raschigattached great importance to the violet acid discovered by Sabatier.He gives experiments to prove that although this compound isproduced in the reduction by mercury of a solution of chambercrystals in 85 to 100 per cent. acid, it was not formed in more diluteacid in this way, and he concluded that the chamber crystalscould not exist in acid containing less than 80 per cent. of sulphuricJ. SOC. Chem. €nd., 1912, 31, 367 ; A . , ii, 550.37 Ibid., 1911, 30, 166 ; A., 1911, ii, 272.33 I h X , 594; A . , 1911, ii, 59646 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.acid.Hence, as he found that the violet acid can be formed bythe action of sulphur dioxide on nitrous acid in a 70 per cent.solution of sulphuric acid, he maintains that the violet acid is thedirect product of the interaction between nitrous and sulphurousacids, and that it could not have been formed by the reduction bysulphurous acid and chamber crystals, because the latter werenon-existent.Reynolds and Taylor prove conclusively that chamber crystalscan exist even in 60 per cent. sulphuric acid, and they satisfy them-selves that Raschig’s explanation of the formation of sulphuric acidis wIong. Their evidence proves first that the only gaseous productin the interaction of sulphurous and nitrous acids is nitrous oxide,and secondly, that Sabatier’s violet acid is only formed in solutionscontaining chamber crystals ; thus they conclusively indicate thefutility of a l l attempts to account for the formation of the bulkof the sulphuric acid in the chambers by the intermediary forma-tion of nitrogen sulphonic acids.They believe that the old viewssubstantially represent the course of the process, namely :(i) SO, + H20 = H2S03.(ii) H,SO, + NO, = NO + H,SO,.(iii) 2NO + O,= 2N0,.The nitrous oxide which escapes may be a measure to some extentof the extent to which nitrogen sulphonic acids are formed,although the work of Moser 39 leaves it uncertain as to whether thismay not have been partly derived from the decomposition of thenitric oxide in contact with the water locally. It must be regardedas doubtful if nitrososulphuric acid (chamber crystals) plays animportant part in the process.The authors agree with Divers inexpressing a doubt as to whether it is ever formed except by theaction of sulphuric acid on one of the oxides of nitrogen, but assulphurous acid reacts with a solution of chamber crystals somesulphuric acid is possibly formed in this way.40In connexion with the contact process of sulphuric acid manufac-ture, Wieland 41 has investigated the reaction which takes placewhen moist sulphur dioxide is passed over palladium-black, oxygenbeing rigidly excluded. He found that considerable heat isdeveloped, and that after driving off the excess of sulphur dioxidewith carbon dioxide and extracting the palladium-black with water,considerable quantities of sulphuric acid are present in the solution.This sulphuric acid is formed according t o the equations:&SO, = SO, + H, and SO, + H,O = E,SO,.39 Zeitseh.anal. Chein., 1911, 50, 401 ; A . , 1911, ii, 598.40 For further experiments contradicting Raschig’s theories see Manchot, Zeitsch.41 Ber., 1912, 45, 685; A., ii, 343.angew. Chm., 1912, 25, 1055; A . , ii, 637INORGANIC CHEMISTRY. 47It was not found possible to detect the hydrogen which is pro-duced according to the first equation, for sulphur is deposited in itsplace, being formed by the action of palladium hydride on sulphurdioxide.SO, + ZH, = 2H20 + S,this being shown by the sulphur which is produced when a solutionof sulphurous acid is shaken with palladium hydride.Further, if apalladium-black is used which has initially been freed fromhydrogen, the yield of sulphuric acid is increased and less sulphuris formed, which suggests that in the contact process for makingsulphuric acid the above equations represent what really happens,the hydrogen formed in the first reaction being oxidised to waterby the oxygen which is mixed with the sulphur dioxide. Wielandpoints out that this view is supported by the fact that no uniontakes place between the sulphur dioxide and the oxygen if theseThe reaction took place according to the equation:gases are dry.The Rusting of Iron.An important contribution to the literature on the rusting ofiron has been made by Lambert.*2 I n spite of the fact that muchexperimental work has been done in recent years to prove thatordinary iron will always undergo corrosion when placed in contactwith water and oxygen, even in the absence of carbon dioxideand other acids, this work has been criticised by the supporters ofthe acid theory on the ground that sufficient care has not beentaken to remove all traces of carbqn dioxide from the apparatus.I n the present paper Lambert describes his experiments, in whichiron was exposed to pure water and oxygen, the most rigid precau-tions being taken t o exclude every trace of carbon dioxide and anyother acid.Both the oxygen and the water were subjected to avery careful spectroscopic test, and not the slightest trace of carbondioxide was found in either. The result of the experiments wasthat the rusting seemed to take place as quickly as in ordinaryair. It can no longer be maintained that carbon dioxide or anyother acid is the dominant factor in the atmospheric corrosion ofcommercial iron.As was pointed out in last year’s report, anelectrical theory has been put forward to explain this phenomenon,and Lambert develops this theory in his paper, and brings forwardconsiderable evidence in strong support of it. I n the first place,some absolutely pure iron was prepared, and it was found that notrace of corrosion took place when it was kept in contact witheither pure water and pure oxygen, or air and ordinary tap water,for an apparently indefinite time. The explanation of this fact is42 T., 1912, 101, 205648 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to be sought in the greater homogeneity of the iron. I f the ironbe really homogeneous, and all parts have the same solution pres-sure, then sufficient difference of potential will not exist, and norusting will take place.Furthermore, some pieces of this pure ironwhich have been exposed to water and air for some months withoutshowing any corrosion were carefully dried; some of the pieceswere then placed in an agate mortar and pressed strongly with anagate pestle, whilst others were left untouched. All were then putin contact with the water and exposed to the air. Those pieceswhich had been pressed rapidly corroded, rust forming on thoseparts of the iron which had not been pressed, whilst the partswhich had been in actual contact with the polished agate remainedquite bright.Those pieces of iron which had not been subjected topressure showed no sign of corrosion. Evidently, therefore, theapplication of the pressure induced a change in the iron, giving ita new solution pressure, so that electrical action was set up when itwas placed in contact with water. An interesting fact was alsonoticed in that chemically pure iron can be exposed for an appa-rently indefinite time to a saturated solution of copper sulphate orcopper nitrate without the slightest trace of copper being deposited.Copper is, however, deposited on the iron if it is pressed in anagate mortar before being put in the solution, or if pressed with aquartz rod whilst under the solution.I n the case of copperchloride, however, even the purest iron reacts, and becomes coatedwith copper immediately i t is put into the solution. The authorhas no completely satisfactory answer to the question as to whythe chloride has this abnormal effect, and for the present leaves itan open question. It is interesting to note that all the samplesof pure iron may not behave exactly in the same way, even thoughprepared from the same specimen of ferric nitrate. Some will showno corrosion after contact with water in air for an indefinite time,whilst other specimens show corrosion in a few hours. The differ-ence in behaviour cannot be due to different chemical composition,and must be due to physical differences produced by variation intempering and rate of cooling in the preparation.It would seemprobable from these results that the fundamental cause of thecorrosion of iron is not carbon dioxide or any other acid, but thatthe cause is rather to be sought in the difference of solution pressureof the different parts of the iron, differences which may persisteven in the most highly purified form of the metal.Electric Discharge.During the past year Strutt has carried out further experimentsH e finds43 that the active on his active modification of nitrogen.4J Proc. Roy. SOC., 1912, A, 86, 262 ; A . , ii, 447INORGANIC CHEMISTRY. 40modification emits its energy more quickly and reverts sooner toordinary nitrogen if i t is cooled. This would appear to be the firstcase in which a chemical or physico-chemical change is increased invelocity by cooling.If the glowing gas is compressed to a smallvolume it flashes out with great brilliance, and exhausts itself in sodoing. The glow transformation seems to be a multimolecularphenomenon. The active nitrogen may revert to ordinary nitrogenin two ways. The first way consists in a volume change accom-panied by a glow, and the second in a surface action on the wallswithout glow. This is analogous to hydrogen and oxygen produc-ing water, which may be a surface or a volume effect according tothe circumstances. In a second paper Strutt 44 describes experi-ments which prove that active nitrogen is highly endothermic, butthat its energy is of the same order as that of other chemicalsubstances.I n the reversion to ordinary nitrogen, the numberof atoms ionised is a very small fraction of the total concerned.The ionisation, therefore, is a subordinate effect, and may be dueto light of very short wave-length being emitted during the change.I n this paper further proof is adduced that the change is acceler-ated by cooling, and Strutt puts forward the view that the pheno-menon is connected with a monatomic condition of the nitrogenmolecule. Strutt and Bowler *5 describe the production of variousspectra by means of the nitrogen glow, and they do not find thatthose spectra differ materially from those produced in ordinaryways. Certain minor differences are, however, to be noticed, andthe method certainly adds to our resources in producing spectra,.I n this connexion an interesting paper has been published byLowry46 dealing with the action of the spark gap and an ozonisingapparatus on the .production of nitrogen peroxide. The presenceof this gas was detected, and its amount estimated spectroscopically.A 19.5 m.[64 feet] column of the gas was used, and the light of aNernst lamp, after passage through this, was examined with asingle-prism spectroscope, and also its spectrum photographed. Theozoniser consisted of 13 Andreoli aluminium grids, 76.2 x 76.2 cm.[30 x 30 inches], separated by micanite. I n the spark gap apparatusthere were in the first experiments three spark gaps made by fixingiron studs 0.238 cm. [3/32nd inch] apart. It was found that if astream of air was passed though the ozoniser or through the sparkgaps alone, no trace of nitrogen peroxide was visible, but if the airwas passed through the spark gaps and ozoniser arranged in series,then about 1/4000th part by volume of nitrogen peroxide wasproduced.It was also noticed that if a current of air passed44 Proc. Lay. Soc., 1912, A, 87, 179 ; A , , ii, 935.45 Ibid., 1912, A, 86, 105 ; A., ii, 214. 46 T., 1912, i01, 1152.REP.-VOL. IX. 50 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.through the spark gaps first and then through the ozoniser, aboutan equal quantity of nitrogen peroxide was obtained. This resultis somewhat extraordinary, seeing that ready-made nitrogen per-oxide is bleached on being passed through an ozoniser. Lowry alsofound that if the ozoniser and spark gap were used in parallel andthe air emerging from them was mixed, nitrogen peroxide was alsoproduced. Evidently, theref ore, the nitrogen peroxide cannot bedue to a simple electrical action, but must be the result of a chemi-cal interaction between ozone and some oxidisable form of nitrogenprbduced in the spark gap.A second spark gap apparatus was setup containing seveqteen spark gaps, and the whole of the availableelectrical energy was concentrated on this. When the air issuingfrom this apparatus was rapidly passed through the absorptiontube it showed the presence of 1/7000th part of nitrogen peroxide,and when passed more slowly it showed 1/3000th part of theperoxide. No such increase of intensity of the nitrogen peroxidewas found in the gases prepared with the help of ozone. This provesthat the nitrogen peroxide formation is gradual and not instan-taneous. As nitric oxide is only slowly oxidised by oxygen andquickly by ozone, it is conceivable, of course, that ozone acceleratesthe formation of nitrogen peroxide in the above experiment.This,however, cannot be the case, since the seventeen spark gaps onlygave a yield 30 per cent. greater than the three spark gaps withozone. Lowry believes that the nitrogen is not oxidised by theozone, but that an active form of nitrogen is produced which isreadily oxidised by ozone. It is interesting that Strutt’s activenitrogen is not the same, since the latter when mixed with ozonisedoxygen a t low pressures and cooled with liquid air gives no traceof the oxides of nitrogen.It is not unreasonable to ask whetherthe production of nitrogen oxides in any form of electric dischargeis not due to the interaction of active nitrogen and ozone or atomicoxygen.Langmuir 47 claims t o have prepared a chemically active form ofhydrogen. If metallic filaments of tungsten, palladium, orplatinum are heated to a high temperature in hydrogen at verylow pressure (0.01 to 0.001 mm.) the hydrogen slowly disappears.It dissolves in the metals as hydrogen atoms, and these atomsappear to diffuse out, and then have little opportunity of joiningtogether again to form molecules, owing to the high temperatureand low pressure, and they are absorbed on the glass walls.Cool-ing the latter improves the yield. The maximum yield was7-3 cu. mm. This hydrogen appears to be extraordinarily active,giving, for example, hydrogen phosphide with phosphorus. Hydro-47 % Amcr. Chcm. Xoc., 1912, 34, 1310; A., ii, 1162INORGANIC CHEMISTRY. 51gen phosphide was placed in the apparatus, and was entirely disso-ciated, the yellow deposit of phosphorus being clearly seen. Thiscombined with the active hydrogen regenerating a certain amountof hydrogen p hosp hide.Pho t och em is t r y .Although perhaps this subject may be considered to fall moreespecially within the confines of physical chemistry, yet it is diffi-cult to omit in a report on inorganic chemistry all reference tothe extraordinarily interesting and important work which has beencarried out during the past year on photochemical reactionsbetween inorganic substances.There cannot be any doubt thatthis line of investigation promises to throw great light on themechanism of chemical reactions and on the affinity relations ofchemical compounds which are gradually being recognised as offundamental importance as the driving force of all chemical pro-cesbes. Marmier 48 has found that a dilute solution of sodiumthiosulphate (containing less than 6 grams in 1 litre) is decomposedunder the influence of light. The action of the light from a240 watt lamp placed 6-8 cm. above such a solution is to producesodium hyposulphite and some sulphur. After seventy minutes’exposure the solution was then found to contain only sodiumsulphite. The light seemed to have no action if a stronger solutionof thiosulphate was used.Reynolds and Taylor 49 have carried out an important investiga-tion on the decomposition of nitric acid by light, and they findthat the reaction takes place according to the following equation :4HN0, = 2H20 + 2N204 + 0,.The 100 per cent.acid when kept in the dark begins t o decom-pose spontaneously after about one month. When, however, theacid contains water i t is readily decomposed by light, and thereaction is reversible.Winther 50 points out that under the influence of ultraviolet lightferrous chloride is oxidised by mercuric chloride according t o thefollowing equation :2FeC1, + 2HgC1, = 2FeC1, + Hg2Cl,;this reaction is reversible, but the reverse process moves very slowlyindeed, unless it is so arranged as to give an electric current, whenit proceeds much faster.Sometimes a potential difference of asmuch as 0.1 volt has been obtained with a current of 1 milliampere.Boll and Job51 have measured the change in conductivity of the48 Compt. rend., 1912, 154, 32 ; A., ii, 112.51 Cow@. Tend., 1912, 154, 881 ; A., ii, 407.4g T., 1912, 101, 131.Zeitsch. Elektrochem., 1912, 18, 138 ; A . , ii, 318.E 52 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hydrochIoroplatinic acids produced on exposure to light. Veryconcordant results were obtained, which showed that tbe reactionwas bimolecular. Matuschek and Nenning 52 find thah manychemical reactions are accompanied by evolution of light.Thereactions were caused t o take place in a beaker, a t the bottom ofwhich a piece of tin foil cut in the form of a star was attached,tbe whole standing on a photographic plate. The following reac-tions were found to give out light: The action between sulphuricacid, hydrochloric acid, or nitric acid and copper, tin, or lead, Alsoduring the solution of cupric oxide, cupric hydroxide, or potassiumhydroxide in acids, the slaking of lime, the setting of cement andplaster, and tho reaction between water and calcium carbide, thereis an evolution of light. This work, however, has been criticisedby Schneckenberg,53 who says that the effects obtained are probablydue to the photochemical action of the heat rays given out duringthe reaction on the photographic plate.Bennett 54 has investigatedthe photochemical reduction of copper sulphate solutions in thepresence of reducing agents, the latter being present in quantityinsufficient to cause the reduction to take place in the dark. I none set of experiments a dilute ethereal solution of phosphoruswas added to the copper sulphate solution, and it was found thatthe precipitation of copper phwphide was obtained very much morequickly under the influence of light than in the dark; in fact,when t,he relative concentrations were properly balanced, the reduc-tion would not take place in the dark at all, but took place readilyunder the influence of light.Lewis 55 has investigated the photochemical decomposition ofsodium hypochlorite solutions into sodium chloride and oxygen.The hypochlorite solution exhibits a marked absorption band inthe ultraviolet region, and i t would seem from the author’s observa-tions that this light in being absorbed produces the chemicalchange.Inasmmh as the reaction proceeds slowly in the dark,the phenomenon belongs to that class known as catalytic lightreactions. I n two papers56 a theory was put forward which wouldseem to offer an explanation of the mechanism of photochemicalreactions. Every atom in a chemical molecule possesses a certainamount of free affinity, and the force lines due t o these free affini-ties must condense together with the escape of free energy. Ittherefore follows that the reactivity of such a condensed system isless than when the system is unlocked by some suitable means.Thisunlocking may be produced by the influence of a solvent or of lightor of both together. Owing to the fact that the light is thereby6z Chem. Zeil., 1912, 36, 21 ; A., ii, 116.c4 J. Physical Cheat., 1912, 16, 782.53 Ibid., 278.65 T., 1912, 101, 2371.66 Ibid., 1469, 1475INORGANIC CHEMIS'L'RY. 53doing work against chemical forces, the light will be absorbed. 15follows naturally that the chemical reactivity of a molecular systemmay be materially increased under the influence of light of theright wavelength. This theory would also seem to explain theresults obtained by Chapman57 and his ceworkers on the photo-chemical reactions of chlorine. One of the most striking resultsof this work is the inhibiting action of nitrogen chlorides on theunion of hydrogen and chlorine.It would seem that these sub-stances exert as grsat a negative catalytic action as water exerts apositive catalytic action on other reactions. Whilst this action ofthe nitrogen chlorides might conceivably be due to their power ofabsorbing the active light rays, yet it would seem far more probablethat these substances have the power of preventing the opening ofthe closed force systems of the chlorine molecule by light. Thewriter would suggest that this may possibly be put to experimentalproof. I f a beam of light of fixed intensity be allowed to fall ona mixture of pure hydrogen and chlorine, the velocity of combina-tion can be measured, and if the light be previously passed througha tube containing chlorine the velocity of combination will bedecreased; then if a small quantity of nitrogen chloride be addedto tho chlorine in the first absorption vessel, the velocity of com-bination of the hydrogen and the chlorine in the second vesselshould tend t o increase.Colloids.Dumanski 5~4 describes the properties of colloidal arsenic tri-sulphide.It is a negatively charged colloid, which may be segre-gated by rapid centrifuging. The density of the material wasfound to be 2.938, and its specific conductivity to be 136x 10-6.The solution is coagulated by certain electrolytes, whilst othersreact with the sulphide; thus an iodine solution reacts accordingto the following equation :AS&& + 101 + 5H20 =Asz05 + lOHI + 35.SimilarIy, a solution of potassium permanganate, decolorised byhydrogen peroxide, oxidises the sulphide to arsenic oxide, no coagu-lation taking place.Solutions of alkali hydroxides and of potass-ium cyanide have no coagulating action. On the other hand, silvernitrate and copper sulphate coagulate the colloid, but the precipi-tate contains considerable quantities of silver or lead. Leadacetate coagulates the colloid, but no lead sulphide is precipitated.57 For an excellent review of the work on the influence of light on the union of55 Zeitsch. Chein, Ind. Kolloide, 1911, 9, 262 ; A., ii, 153.hydrogen and chlorine, see Chapman, Science Progress, 1912, 6, 656 ; 7, 6654 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.J. Hoffmann59 shows that the colour of ultramarine is due tocolloidal sulphur, and that a number of compounds act a6 suitablesolvents for colloidal sulphur. The silica in ultramarine can bereplaced by boron trioxide without the disappearance of the bluecolour.Furtbermore, the colour does not greatly alter when thesolvent is varied from Na,B,O,, to Na,B,,O,,. Potassium thio-cyanate when dehydrated and heated to redness becomes blue, sohere, again, a suitable solvent exists for the colloidal sulphur. Phos-phoric oxide when fused a t 900° with sodium sulphide gives a bluecolour, which, however, disappears on cooling.Hatschek 60 has carried out investigations into the production ofsubstances in the gel of silicic acid.This acid is added to a15 per cent. solution of sodium silicate, and after solidification ofthe silicic acid a hypertonic solution of a salt is added, the acid andthe positive ion of the salt being so chosen that a salt separates ofitin the solid form within the gel. I n this way lead chloride, andcopper, calcium, and strontium phosphates were obtained in thecrystalline form. I n a second paper61 the author deals with thereduction of gold in the silicic acid gel. Both solutions and gaseswere used as reducing agents. I n the former case the reducingagent was poured over the gel which contained gold chloride, and inthe latter case the gel in a test-tube was exposed to the gas. Undersuitable conditions the gold was always deposited either in thegel or on the surface of the gel, or both a t once, depending on theosmotic relationships.Furthermore, the gold was obtained inlayers, and finally acetylene was found t o give carbon and goldlayers. The results, therefore, obtained are quik similar t o thenatural deposits which can therefore be explained in this way.A certain amount of work has been done on the preparation ofmetallic sols and metallic organosols. Pappadb 62 describes thepreparation of colloidal silver, gold, and platinum. These arenegative colloids, and their reactions towards electrolytes are similar,but the most active of the three is silver. Amberger 63 describesthe preparation of metal organosols. If lanolin, impregnated withthe aqueous solution of the salt of a heavy metal, is triturated witha solution of alkali hydroxide, the hydroxide of the heavy metalin colloidal condition is obtained.I f the oxides are readily reduced,then the colloidal metal may be obtained after the removal of waterand all electrolytes. The residue will dissolve in any lanolinsolvent, and on evaporation of this solvent solid sols with a high59 Zeitsch. Chem. Ind. Kolloide, 1912, 10, 275 ; A., ii, 752.Ibid., 77 ; A., ii, 449.61 Ibid., 265 ; A., ii, 772.62 ]bid., 1911, 9, 265, 270 ; A., ii, 157, 169.G3 Ibid., 1912, 11, 97, 100; A., ii, 1053, 1059INORGAWIC CHEMISTRY. 55percentage of the metal are obtained. The lanolin acts as a protec-tive colloid, and with the lanolin alcohols (cholesterol and isochole-sterol) sols can be obtained with an even higher metal content.Colloidal gold can be obtained in this way, hydrazine hydrate beingused as reducing agent.The final product is soluble in ether,light petroleum, fats, and liquid paraffin t o a solution having adeep blue colour, their solution in chloroform being reddish-violet.The addition of alcohol to the light petroleum solution precipitatesa pasty product containing 84 per cent. of gold. Such productswhen dried are granular and golden-brown in colour. They dissolveeasily in fats or liquid paraffin, bu6 sparingly in ether or lightpetroleum.Rare Earths.Pure metallic cerium has been prepared by Hirsch64 from thetrichloride which is dehydrated, and then electrolysed after fusionin an iron crucible. The cerium thus obtained contains about 2 percent.of impurities, f o r the most part iron and cerium oxide. I norder to obtain the pure metal the impure product is amalgamatedin boiling mercury, when the impurities may be skimmed off. Theamalgam is then distilled in a quartz vessel lined with magnesia.The pure metal has a density of 6-92 a t 2 5 O , and is almost as softand malleable as lead.Dafert and Miklauz65 have prepared the nitride and hydride ofcerium. When metallic cerium is heated in a current of hydrogenit begins to absorb the gas a t 310°, and the reaction is complete a t450°, cerium hydride being formed. This compound is dark blue orblack, and is spontaneously inflammable in air. I f moist air ispassed over the substance no ammonia is formed, but when thesubstance spontaneously burns in air some nitride is formed, whichgives ammonia with moisture.When the hydride is heated to from800° to 900° in nitrogen the pure nitride is formed. This compoundis not formed when cerium itself is heated in nitrogen; no ammoniais formed in the reaction, nor is there any ammonia formed whenthe nitride is heated in hydrogen. These authors were unable toobtain any evidence of the existence of imide compounds or of anycompound of cerium with nitrogen and hydrogen.Some doubt has been thrown by von Welsbach on the elementarycharacter of both terbium and thulium. Welsbach himself does notappear to have continued these investigations, nor do they seemto have been criticised or denied by later workers.It wouldcertainly seem that they merit further and independent investiga-64 Trans. Amer. Electrochcnt. Soc., 1911, 20, 57 ; A . , ii, 258.65 Monntsh., 1912, 33, 911 ; A., ii, 94256 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.tion. I n one paper,66 which deals with the fractional crystallisationof the double o x a l a k of the rare earths with ammonium, he saysthat the terbium is found distributed in the gadolinium anddysprosium fractions. The separation of the three elements istedious, but may be carried out satisfactorily. The first and mostinsoluble product contains the gadolinium, whilst the final onecontains the dysprosium. When optically tested these two fractionsare found to be free from terbium. The oxides are coloured deepcinnamon or ochre, and they have peroxidic properties.I n this wayit may be seen that terbium has been resolved into more than oneelement. Exner and Hnschek have shown that the spectrum ofterbium contains many lines which are common to gadolinium anddysprosium. Von Welsbach repeated these spectroscopic tests, usingmuch purer materials, and obtained the same results. The linescommon to the three spectra were found to be so strong in themiddle fraction as t o leave no doubt as to the presence of thesenew elements. He calls them TbI and TbIII, the former beingclosely related to gadolinium and the latter to dysprosium. Hepoints out that these two new elements, which are present in largeamounts in the gadolinium and dysprosium fractions of the terbiumseries, should easily be separated.Welsbach67 has drawn a somewhat similar conclusion as regardsthulium, which, from a spectroscopic point of view, he believesmust consist of a t least three elements.Meyer and Goldenbergm have carried out an investigation onthe properties of scandium oxide.They separate the thorium fromscandium by the addition of potassium iodate, which is added inslight excess so that some scandium iodate was precipitated.Different specimens of scandium oxide freed in this way fromthorium gave the atomic weight of scandium as 44-1-44.2. Thisagrees with Nilson’s value. Meyer, Winter, and Speter,69 on theother hand, using scandium which had been purified from thoriumby the sodium carbonate method, found the atomic weight to be 45.Meyer and Goldenberg investigated the arc spectrum of thescandium oxide fractions which had atomic weight 44 and 45 respec-tively, and they found that there was no difference between them.They conclude, therefore, that the method is not.delicate enoughfor the detection of 0.5 per cent. of thorium. The magnetisation-coefficient, however, affords a much more delicate test, as thescandium oxide (atomic weight = 45) gives a value of + 0.04 x 10-6,86 Chem. Zeit., 1911, 35, 658.67 Monatvh., 1911, 32, 373 ; A . , 1911, ii, 607.m Chem. News, 1912, 106, 13 ; A., ii, 768.69 Zeitoch. anorg. Chem., 1910, 67, 398 ; A., 1910, ii, 854lNORGANIC CHEMISTRY. 57whilst the scandium oxide (atomic weight = 44) gives a coefficient of-0-12 x 10-6.Scandium is diamagnetic, as also are lanthanumand yttrium, which also belong to group I11 in the periodic table.Some interesting experiments have been carried out by Joye andGarnier 70 on the hydrated oxides of neodymium. It is well knownthat’ neodymium hydroxide gives a different reflection spectrumfrom neodymium oxide. By heating the hydroxide t o various tem-peratures and observing the spectra, they have succeeded in estab-lishing the existence of two new hydrates, namely, 2Nd203,3H20and 2Nd203,2H20. The first of these is formed a t 310--325O, andthe second a t 525O.Urbain and Bourion 71 have succeeded in preparing europouschloride by reducing europic chloride in hydrogen a t 400--450°. Itis a colourless, amorphous compound, which is soluble in water to aneutral solution.A t looo the solution oxidises according to theequation :12EuC1, + 30, = 8EUC’13 + 2Eu20,.The europous chloride is more stable than the correspondingsamarium compound, which is the only other lower chloride knownin the group.Two papers have been published dealing with isomorphic series ofsalts of the rare earths. In the first of these, Billows 72 describes thepreparation of a complex molybdate having the composition(NH,)6R,Mo,,02,,24H,0, where R = Ce, La (Ce La), Nd, Pr, Sm.He found that all these crystallise in the triclinic system, and areperfectly isomorphous. I n the second paper, Jantsch 73 hasdescribed the double nitrates of formula M”’(NO3),M,”,24(H2O),where M’I’=La, Ce, Pr, Nd, Sa, Gd, and M/’=Mg, Zn, N, Co, Mn.The only exception is the double nitrate of gadolinium and man-ganese, which is too soluble t o crystallise well.All the other saltsare isomorphous, and crystallise well; all melt in their water ofcrystallisation a t definite temperatures, and these temperaturesfall as the elements are substituted in both series in the order inwhich they are given above. The solubilities follow the same order,the magnesium salts being the least soluble. The cerium doublesalts, however, are less soluble than those of 1ant.hanum. Themolecular volume curves show close parallelism in the case of themagnesium, manganese, nickel, cobalt, and zinc salts. The molecularvolume of the cobalt salts is greater than that of the nickel salts,and that of the neodymium salts greater than that of the praseo-7O Compt.rend., 1912, 154, 510 ; A., ii, 352.72 Zeitseh. Kryst. Min., 1912, 50, 500; A . , ii, 560.l3 Zcitsch. anorg. Chem., 1912, 76, 303 ; A., ii, 767.Ibid., 1911, 153, 1155 ; A., ii, 16258 ANNUAL REPOnTS ON THE PROGRESS OF CHEMISTRY.dymium salts, so that in both cases the order is the reverse of thatwhich would be expected from the periodic law.A considerable amount of work has been carried out on the rareearths by James and his c0lleagues.7~ I n one paper are describedthe preparation and properties of the salts of samarium and neo-dymium of a very large number of organic acids, mainly sulphonicacids of the aliphatic series. This formed part of a search forsatisfactory salts for the purposes of fractionation.In two otherpapers,75~ 76 the application of sebacic acid is described for the quan-titative precipitation of thorium and yttrium. In the case ofthorium an aqueous solution of the acid is added to a neutral solu-tion of the thorium salt., when thorium sebacate is precipitated.This method can be used for the quantitative separation of thoriumin the presence of cerium, lanthanum, praseodymium, neodymium,samarium, and gadolinium. It is also of value for the separationand purification of thorium. Pyrotartaric acid may also be used,and when added to a cold neutral solution of the thorium salt noprecipitate is obtained, but, on boiling, the thorium pyrotartrate isquantitatively precipitated. In the case of yttrium the elementmay be quantitatively separated from certain other elements asfollows: A single precipitation with ammonium sebacate gives aquantitative separation of yttrium from sodium, whilst a doubleprecipitation gives a precipitate completely free from potassium.On the other hand, oxalic acid gives the most satisfactory separa-tion of yttrium from iron, aluminium, lithium, and magnesium.Finally, James77 has described a complete scheme for the separa-tion of the rare earths from one another.This scheme is, of course,far to9 long to be detailed in this report, but no account of theprogress of work done in this field of research would be completewithout including, a t any rate, this brief mention.Group I .Ermen78 has investigated certain basic salts of copper, and hefinds that, with N / 10-solutions, the addition of sodium hydroxideto copper sulphab until all the copper is precipitated, or the addi-tion of copper sulphate to sodium hydroxide until the copper justappears in the solution, two molecules of copper sulphate and threemolecules of sodium hydroxide always react together.The bluebasic sulphate, CuS04,3Cu(OH),, is precipitated, the same com-74 James, Hoben and Robinson, J. Amr. Chem. SOC., 1912, 34, 276, 281 ; A.,i, 233.75 Smith and James, ibid., 281 ; A., ii, 390.78 Whitternore and James, ibid., 772 ; A., ii, 690.77 Ib'bid., 757 ; A . , ii, 690.76 J. SOC. Chem. I n d . , 1912, 31, 312 ; A . , ii, 453INORGANIC CHEMISTRY. 59pound being obtained if the sodium hydroxide solution is added tothe solution of copper sulphate when boiling. On the other hand,the addition of copper sulphate t o a boiling hydroxide solutionprecipitates the black oxide of copper, which is not completely con-verted into the basic salt even on prolonged boiling.Evidencewas also obtained of the existence of a green basic salt containing3.5 of copper and 1 of SO,. On mixing cold dilute solutions ofcopper sulphate and sodium carbonate, one molecule of each saltreacts together, and the blue basic carbonate, CuC'O,,Cu(OH),,H,O,is precipitated. On keeping, this compound changes into malachite,CUCO,,CU(OH)~. From this substance sodium hydroxide removesall the carbon dioxide. When sodium carbonate solution is runinto a boiling solution of copper sulphate, the blue compound,CUSO,,~CU(OH)~, is also obtained. When copper sulphate isadded t o aqueous ammonia until a permanent precipitate is pro-duced, one molecule of copper sulphate is found t o have reactedwith .four molecules of ammonia.The addition of more coppersulphate until the solution becomes colourless gives the compoundCuS04,2Cu(OH),. If an aqueous solution of copper sulphate issaturated with ammonia gas a precipitate is obtained having thecomposition CuS0,,4NH3,H,0. This substance is also formed bytriturating copper sulphate crystals with strong aqueous ammonia,or by adding anhydrous copper sulphate to strong ammonia SO~U-tion. It is also obtained by exposing the compound CuS04,5NH,to moist air.Gumming and Gemme1179 have investigated the trihydrate ofcopper nitrate.It is best prepared by dissolving cupric oxide inconcentrated nitric acid. The salt may be recrystallised from hotconcentrated nitric acid, and may be dried on a porous tile overpotassium hydroxide. If the nitric acid is obtained by distillationfrom sulphuric acid in a current of carbon dioxide, the cupric oxidereacts with i t a t a temperature of 70-75O. Nitrogen peroxide andoxygen are evolved, the process taking place according to theequation :CUO + 6HN03= C'U(NO~)~,~H,O + 4N02 + 0,.The hexahydrate of copper nitrate when dried in a vacuum overphosphoric oxide readily loses three molecules of water, giving thetrihydrate. It would appear that the only basic nitrate of copperis Cu(N03),,3Cu(OH),, and this may readily be prepared by heatingthe trihydrate to looo or by boiling a concentrated aqueous solutionof copper nitrate with cupric oxide. The transition temperaturebetween the two hydrates of copper nitrate has been found to be24'66O with the dilatometer and 24-65O thermometrically.59 PTOC.Eoy. Sac. Edin., 1912, 32, 4 ; A., ii, 55660 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,BaubignygO finds that on heating copper sulphate solution withan excess of sodium sulphite solution so that the precipitate firstformed is redissolved, and if the resulting colourless solution isheated on a water-bath, a red precipitate is formed, which is adouble compound of sodium sulphite and cuprous sulphite, whilstthe solution contains sodium dithionate. The process takes placeaccording to the equation :2CuS0, + 4Na2S03 = 2Na,SO, + CI.$~O,,N~&~O, + Na.$3,06.If aqueous solutions of copper sulphate and sodium sulphite aremixed in a sealed tube a t the ordinary temperature, then after somehours colourless crystals are formed having the constitutionCu,S03,Na2S0,,1 2H,O.Some interesting work has been carried out by D’Ans andFriederich 81 on the preparation of derivatives of hydrogen per-oxide, in which the hydrogen atoms have been partly replaced bysodium or potassium. An ethereal solution of pure hydrogen per-oxide reacts with metallic sodium to give a white solid havifig theformula 2NaH0,,H,02.This compound is identical with that p r epared from the action of hydrogen peroxide on sodium ethoxide.82Metallic potassium acts more vigorously than sodium, and gives asubstance having the formula 2KH0,,3H20,.When an absolutealcoholic solution of potassium hydroxide and hydrogen peroxideare mixed they then give 2KH0,,H20,, a compound which haspreviously been obtained by Schone.83The phosphides of czsium, rubidium, potassium, and sodiumhaving the general formula M,P, have been studied by Hackspilland Bos~uet.*~ Two or three grams of the metal and a largeglobule of phosphorus are distilled successively into an exhaustedtube, and the mixture heated to 400--5OOO. The black mass thusobtained still contains free metal, but after continuing the heatingfor about one hundred and fifty hours this is volatilised, and thephosphide appears reddish-brown. A t temperatures between 00and looo the four compounds resemble cadmium sulphide in colour,they become darker at higher temperatures, and are almost colour-less a t the temperature of boiling nitrogen.They melt at 650°with loss of phosphorus. They decompose in air, and when treatedwith water give a solid hydride of phosphorus with a small amountof hydrogen phosphide and hydrogen.Barhieri s5 claims to have prepared a compound containinggo Cowpt. rend., 1912, 154, 434, 701 ; A., ii, 351, 447.g1 Zeitsch. unorg. Chem., 1912, 73, 325 ; A., ii, 151.d2 \Volffenstein and Peltner, Ber., 1908, 41, 280 ; A., 1908, ii, 180.83 Airnalen, 1878, 193, 276, 289 ; A., 1878, 931.a1 Compt. rend., 1912, 154, 209 ; A., ii, 252.Atti R.Acead. Lincei, 1912, [v], 21, i, 560; A., ii, 763INORGANIC CHEMISTRY. 61bivalent silver. If a solution of silver nitrate in pyridine is addedt o a cold solution of potassium persulphate, a yellow precipitate isobtained, with tliu formula AgS20,,4C,N’H,, and the substanceresembles the corresponding cupric compound. I f very dilutesolutions are used the silver and copper compounds can be precipi-tated simultaneously, and, by varying the proportions of the silverand copper, mixed crystals are formed, showing complete grada-tions of colour between the orange silver compound and the violetcupric compound, thus proving the complete isomorphism of thetwo.Group ZZ.Barre 86 has prepared the double carbonates of calcium withsodium and potassium.If precipitated calcium carbonate is boiledwith a concentrated solution of sodium carbonate, orthorhombiccrystals are formed of Na2C0,,CaC0,,2H,0. A t 9 8 O the compoundis not formed unless the solution contains a t least 21.06 per cent.of sodium carbonate. Under the same conditions potassiumcarbonate gives prismatic needles of I.,CO,,CaCO,, which arereadily hydrolysed by water, and are only stable in a solutioncontaining a t least 59-25 per cent. of potassium carbonate.Niederstadt87 has shown that aragonite and calcite may bedistinguished in that thc former is readily coloured lilac by cobaltsalts, whilst the latter only assumes a bright blue colour on pro-longed boiling. Aragonite is the more active towards manganese,zinc, and iron salts, whilst calcite more readily precipitates copper,lead, and silver.Group ZZI.An important paper has been published by Travers and Rayeson borohydrates.Magnesium powder is heated with boron trioxideto a bright red-heat in a current of hydrogen. When the resultingpowder is treated with water a yellow solution is obtained, whichhas powerful reducing properties; it is slightly alkaline to litmus,and on boiling it gives off hydrogen. The addition of dilute acidcauses an evolution of hydropn, together with a trace of someboron compound. The original solution both before and after theaddition of acid is strongly reducing. It takes up iodine, andprecipitates the heavy metals from solutions of their salts. Theauthors find that the amount of hydrogen evolved on the additionof acid and the iodine equivalent are in the ratio of 1 to 1 o r 1 to 2,86 Conzpt.rend., 1912, 154, 279 ; A . , ii, 254.137 Zeeitsch. angew. Chem., 1912, 25, 1219 ; A., ii, 760.8s Pt-oc. Roy. .voc., 1912, A, 87, 163 ; A . , ii, 93862 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.and analyses show figures that are very near to one or the other ofthese ratios. Furthermore, the solutions contain one atom of boronfor every atom of hydrogen that is evolved when the solution istreated with acid. When the aqueous solutions are evaporated ina vacuum a t low temperatures with the help of a condenser cooledin liquid air, little or no gas is evolved until all the water has beendistilled off. A viscous residue is left, which now proceeds to giveoff hydrogen rapidly, and then sets t o a semi-crystalline or glassysolid.The amount of hydrogen evolved a t this stage is equal tohalf the volume of hydrogen which is given off when the originalsolution is acidified. If the bulb containing the glassy solid is leftconnected to the pump, a further quantity of hydrogen is slowlyevolved, and the amount of this second quantity of hydrogen isequal to the first quantity. On gently heating the substance athird quantity of hydrogen is evolved, which again is about equalto the two amounts previously evolved. It is found that half theboron distils over during the evaporation, and as the distillate doesnot take up much iodine the authors conclude that this volatileboron compound is oxidised.They carried out certain experimentswhich proved that this volatile boron compound is not boric acid,and put forward the view that a polymeride of boron trioxideexists which is not acid, and is volatile; they suggest that theoriginal substances are hydrated derivatives of B402 and B,O,.A second important paper has appeared during the year, namely,one dealing with the hydrides of boron, by Stock and Massenez.89These authors prepared the hydrides from magnesium boride, andsome difficulty was experienced in the preparation of this compoundso as to obtain it good yield of the boron hydrides. The best resultis obtained as follows: one part of very finely powdered borontrioside is intimately mixed with three parts of magnesium powder,and 10 grams of the mixture are rapidly heated in a thin ironcrucible in a stream of hydrogen.The powdered product is slowlydropped into not too dilute hydrochloric acid a t 50-80". The gasevolved is fractionated by means of liquid air. Two hydrides wereisolated, namely, B4HIo and B6H12. The former was analysed bytreatment with water, when the following reaction takes place :B4HI0+ 12H20=4B(OH),+ 11H2.The results of the analysis and the density determinations agreedwith the formula B4H,,. The compound B6H1, was analysed in asomewhat similar way, and its density was also determined, butowing to the small quantities available there is still some doubtas to the number of hydrogen atoms in the molecule.The hydride B4H10 melts a t - 1 1 2 O , and boils between 1 6 O andx9 Ber., 1912, 45, 3539; A ., 1913, ii, 44INORGANIC CHEMISTRY. 6317O/760 mm. The hydride B,H,, should boil a t about looo, butboth compounds are unstable, and tend to decompose a t theordinary temperature, and give a series of further hydrides yetto be investigated. The hydride B,HI, is rapidly absorbed byalkali, and the solution slowly evolves hydrogen, the completereaction being similar to that with water mentioned above. Thehydride B6HI2, on the other hand, gives up hydrogen immediatelywhen treated with alkali.JohnsonQO has found that the alumina formed by dehydratingthe hydroxide a t low temperatures is an excellent drying agent forgases such as hydrogen phosphide, hydrogen bromide, and hydrogeniodide, where phosphoric oxide is useless.It is better than calciumbromide, zinc bromide, or zinc chloride, and is more efficient thansulphuric asid. A tube filled with this alumina can be usedindefinitely, as the substance can readily be dried again by heatingwith a smoky flama in a stream of air dried by sulphuric acid.Terni91 has prepared a peroxide of aluminium by adding anexcess of 30 per cent. solution of hydrogen peroxide to aluminiumhydroxide dissolved in the minimum quantity of 50 per cent.solution of potassium hydroxide. An amorphous, white powder isformed, having a constitution AI,O,,Al,O,,lOH,O. It is a trueperoxide, and Terni believes that the first product of the reaction isAIBO,, which is changed by hydrolysis t o the above substance.Bosshard and Zwicky 92 have investigated the perborates.Twentyof these compounds were heated t o a temperature of 55--65O, eitherunder diminished pressure or in a current of air free from carbondioxide. In only one case was a trace of hydrogen peroxide foundin the distillate. Usually the water of crystallisation distilled over,and the percentage of active oxygen in the salt was increased.Potassium peroxide perborate when dissolved in water evolves onlytraces of oxygen, and when dried in a vacuum over phosphoricoxide four molecules of the salt lose one molecule of water, so it isimprobable that the salt contains hydrogen peroxide of crystallisa-tion. Further, it is found that sodium perborate evolves oxygenwhen treated with colloidal platinum solution more slowly thanhydrogen peroxide solution under the same conditions.Theauthors conclude, therefore, that the perborates do not containhydrogen peroxide of crystallisation, and that they have theconstitution :0M*O*B<A and not M*O*O*B:O.J. Amcr. Chem. Soc., 1912, 34, 911 ; A . , ii, 847.y1 Atti It. Accad. Lincei, 1912, [vJ, 21, ii, 104 ; A., ii, 944.92 Zeilsch. nngew. Chem., 1912, 25, 993; A . , ii, 64064 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.According t o this the potassium salt mentioned above would have00the coiistitutiori K*O*O*B<I, and not K*O.O*O*B:O, as, owing tothe three oxygen atoms existing in the chain, a compound of thelatter constitution would probably be very unstable. They pointoat that Riesenfeld’s test (see under Group IV) fails with per-borates.Group IV.A certain amount of work on silicon hydride has to be reported.Adwentowski and Drozdowski 93 state that pure silicon hydride,SiH,, can only be prepared by repeated fractionation of the gasusually obtained.By the action of hydrogen chloride on mag-nesium silicide a gas is produced from which liquid fractions areobtained, which are mixtures of several silicon hydrides. The pureSiH, is spontaneously inflammable in plenty of air. The weightof one litre is 1.4538 grams. It boils a t -116°/740 mm. Itscritical temperature is - 3 * 5 O , and its critical pressure is 47-8atmospheres.Besson 94 describes certain reactions of silicon tetrahydride.Powdered magnesium with half its weight of powdered quartz isstamped into a crucible and fired by the ignition of some powderedmagnesium placed on the top of the mixture., The magnesiumsilicide obtained when treated with hydrogen chloride gives a gascontaining 6-7 per cent.of SiH,. A gas containing less than0.5 per cent. is not spontaneously inflammable, but fumes in moistair, giving a colourless solid, which varies in composition betweenH,Si,O, and H,Si,O,. In his second paper Besson points out thatthe gas from the magnesium silicide contains hydrogen phosphideand hydrogen sulphide as impurities. These impurities are readilyremoved by passing the gas through a dilute solution of iodine inpotassium iodide or hydriodic acid, and the gas may then be driedwith phosphoric oxide.During the preparation silico-oxalic acid,HzSi20,, separates as a white solid in the reaction mixture, theamount of this being from 25 to 30 per cent, of the weight of themagnesium used. The dry gas is not acted on by light, but underthe influence of the electric discharge it gives a yellow to brownsolid deposit of uncertain composition, which is spontaneouslyinflammable in air. The gas has no action on concentratedammonia solution or liquid ammonia when dry. In the presenceof moisture it gives with liquid ammonia a white solid, which whendried a t looo has the composition H,Si,O,. I f the white solid93 Bt611. Acad. Ski. Cracow, 1911, A, 330 ; A., ii, 44.94 Compt. .rend., 1912, 154, 116, 1603; A., ii, 256, 641INORGANIC CHEMISTRY.65obtained when the gas fumes in moist air is dried a t looo in avacuum for several hours, it has the composition H3Si305. Whencarefully heated in a vacuum it loses hydrogen, and the compositionof the residue approximates t o Si30,.Riesenfeld and Mau 35 discuss the constitution of the percarbon-ates, and they differentiate between t.he true percarbonate and theordinary carbonate containing hydrogen peroxide of crystallisation.Whilst the former give a quantitative separation of iodine fromneutral potassium iodide solution, the latter liberate practically noiodine.96 Even the addition of hydrogen peroxide to a solution ofpotassium percarbonate in the proportion of 2 molecules to 1 causesvery little change in the quantity of iodine liberated.A solutionof potassium percarbonate a t 15O, after keeping for an hour, stillliberates iodine quantitatively from potassium iodide solution,whilst the so-called sodium percarbonate does not liberate iodineeither a t 1 5 O or Oo or even when added as a solid. The authorsconclude that the latter possesses the constitutionSimilarly, Peltner's 97 rubidium percarbonate must have the formulaRb2C0,,3H,02. They also point out that persulphates andsulphates with hydrogen peroxide of crystallisation 96 react towardspotassium iodide in a similar way to the percarbonates. In theiropinion, therefore, this reaction may be considered as a generalone for the differentiation between true per-salts and salts contain-ing hydrogen peroxide of crystallisation.It may be pointed out,however, that the test fails in the case of the perborates (see underGroup 111). Based on the experience gained from these results,Riesenfeld and Mau have investiga€ed the salts formed by theaction of carbon dioxide on sodium peroxide. The four saltsprepared by Wolffenstein and Peltner 99 are found by Riesenfeldand Mau to be really salts of two different acids, namely, monoper-oxycarbonic, H,CO,, and monoperoxydicarbonic acid, H2C,0,, andto have the constitution Na2G04,Na2C04,H202,Na&206 andThey prove this conclusion by comparing the reactions of the foursalts with potassium iodide. They also found that the two pairsof salts were mutually convertible by the addition or withdrawal ofhydrogen peroxide. It was observed that the potassium percarbon-ate, &C206, prepared by electrolytic methods, behaves differently96 Ber., 1911, M, 3589, 3595 ; A., ii, 156.96 Compare Reisenfeld and Reinhold, ibid., 1909, 42, 4377 ; Tmatar, ibid., 1910,97 Ibid., 1909, 42, 1777; A., 1909, ii, 574.ys Willstatter, ibid., 1903, 36, 1828 ; A., 1903, ii, 537.Ber., 1908, 41, 280; A., 1908, ii, 180.Na2C03>q02,&H20 *NazC2Ot3,H%O2.43, 127, 2149 ; Reisenfeld, ibid., 566, 2594 ; A., 1910, ii, 33, 203, 290, 774, 952.REP.-VOL.IX. 66 ANNUAL REPOlllv UN THE PROGRESS OF CHEMISTRY.towards potassium iodide from the corresponding sodium com-pounds, for the potassium a salt gives a quantitative liberation ofiodine, whereas in the case of the sodium salt only about 50 percent, of its active oxygen liberates iodine.By the action of carbondioxide on potassium peroxide a compound, K2C206, was formedwhich behaves towards potassium iodide solution similarly to thesodium compound. This compound, therefore, must be isomericwith ordinary potassium percarbonate, and they suggest that itsconstitution may be represented by K*O*O*CO*O*CO*O~K, asdistinct from KO*CO*O*O*CO*OK.Stock and Praetorius 1 have contributed considerably t o our know-ledge of carbon subsulphide, C,%, first prepared by von LengyeI.2A modificatiori of von Lengyel's method was used in its preparation.An electric arc is maintained with 10 to 15 amperes a t 110 voltsunder pure carbon disulphide between a graphite cylinder ascathode and an anode of graphite and antimony.Finely powcteredantimony and graphite were mixed with sugar solution, and pressedinto rods, which after being dried were heated to carbonise thesugar, A slow stream of carbon dioxide was passed thrpugh theapparatus, and the resulting fluid was shaken with mercury andsome phosphoric oxide to remove the sulphur. When the carbondisulphide had been distilled off, the subsulphide was sublimed in ahigh vacuum using a condenser cooled with liquid ammonia. A tthe ordinary temperature C3S2 forms a clear, red, strongly refractiveliquid, and in dilute carbon disulphide solution it exhibits anabsorption band between 530 and 455 p p . Under the influence oflight it polymerises finally into a black substance, which is unaf-fected by water, hydrochloric acid, sodium hydroxide solution, orchlorine water.The subsulphide reacts a t once with aniline to givethiomalonamide :C3S2 + 2C6H5*NH2 = C'H2(C'S*NH*C6H5),.It is clearly the analogue of carbou suboxide, C,O,.Group V .During the year Franklin has published four papers describingthe preparation and properties of certain amine compounds, thuscontinuing his work based on his ammonia system of acids, bases,and salts. I n a series of papers3 in previous years he has pointedout the analogy between liquid ammonia and water as electrolyticBET., 1912, 45, 3568; A, 1913, ii, 46.Ibid., 1893, 26, 2690 ; A., 1894. ii, 90.3 Frsnkliii and Kraus, Arne?.. Chem. J., 1899, 21, 1, 8; 1900, 23, 277 ;Franklin and Stafford, ibid., 1902, 28, 83 ; Franklin, J.Arne?.. CJienz. Soc., 1905,27, 820 ; A., 1899, ii, 284; 1900, ii, 382 ; 1902, i, 748 ; 1905, ii, 581INORGANIC CHEMISTRY. 67solvents, and the analogy between the reactions which take placein the two solvents. He formulated a system of acids, bases, andsalts on the basis of ammonia as the typical substance, analogous tothe ordinary system of oxygen acids, bases, and salts as derivativesof water. During the present year the system has been furtherdeveloped, and the relationships have been shown to be fully justi-fied. I n the first paper 4 he describes the preparztion of potassiumammoniocadmiate, Cd(NHK),,2NH3, which is obtained by addingpotassamide to cadmium iodide or nitrate dissolved in liquidammonia. This substance corresponds with the zinc compounddescribed by Bitzgerald.6I n a second paper6 Franklin and Hine describe the reactionbetween titanium nitride bromide and potassamide in liquidammonia, which, although the analyses show that absolutely pureproducts were not obtained, would certainly seem to take placeaccording to the equation :NiTi*Br + 2KNH2=NiTi*NHK +I(&+ NH,.In a third paper 7 Franklin describes the action of potassamideon a liquid ammonia solution of Cu(NO3),,4NH,. These compoundsreact according to the equation:3Cu(N03),+ 6KNH,= @u3N,nNH3+ 6KN0, + (4 - n)NH, + N.The copper compound is precipitated, and when warmed to thelaboratory temperature in a vacuum it is converted into cuprousimide, @u2NH, and when heated to 160°, cuprous nitride, Cu,N, isformed.The compounds with the general formula Cu3N,nNH3readily dissolve in liquid ammonia solution of potassamide, and inthis way well-crystallised specimens of a colourless compound havingthe formula CuNK2,3NH3 were obtained. This potassium ammonio-cuprite with three molecules of ammonia of crystallisation loses onemolecule of ammonia in a vacuum at the ordinary temperature, andat higher temperatures it loses a further molecule, formingG'uNK,,NH,.In a fourth paper8 Franklin describes the preparation of thecorresponding thallium compounds. When a liquid ammoniasolution of potassamide is added to a liquid ammonia solution of athallous salt, a black precipitate of thallium nitride is formed ;thus, with thallous nitrate the reaction takes place according tothe equation:3TlN0, + 3KNH, = T13N + 3KN03 + 2NH3.J.Amer. Chem. Soc., 1907, 29, 656; A,, 1907, ii, 546.4 Amer. Chem. J., 1912, 47, 285 ; A., ii, 451.6 IW., 1912, 341, 1497; A., ii, 1168.7 &id., 1501 ; A, ii, 1174.ti J. Physical Chew., 1912, 16, 682 ; A . , 1913, ii, 52.F 68 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.This precipitate readily dissolves in a liquid ammonia solution ofaiiimonium nitrate or potassamide, and so must be assumed to beamphoteric in character. When it is dissolved in a liquid ammoniasolution of potassamide, a yellow solution is formed, from whichyellow crystals of the compound, T1NK2,4NH,, may be obtained.This potassium ammoniothallate readily loses portions of itsammonia of crystallisation, giving the compounds TlNK2,2NH, andTlNK,,l&NH,.When excess of potassamide is used, well-crystallisedproducts are obtained, which are impossible of formulation asdefinite chemical compounds. Franklin looks upon these as iso-morphous mixtures of the compound TlNK2,4NH, with potass-amide, or perhaps rather an isomorphous mixture of the unknownthallous amide and potassamide. Considerable difficulty was foundin the work owing to the great instability of these compounds.They explode violently when heated or subjected to shock, andtheir satisfactory analysis was a matter of considerable difficulty.Dafert and Miklauz9 have made investigations on the amide,imide, and nitride of lithium. Under the influence of sunlightlithiuinimide decomposes with the production of a dark red colour,the reaction being represented by the equation:2Li2NH = Li3N + LiNH,.They find that by the action of nitrogen on lithium hydride,hydrogen on lithium nitride, a mixture of nitrogen and hydrogenor of ammonia on lithium hydride or nitride, lithium-imide, -amide,or trilithiumamide, or mixtures of these compounds are formedaccording to the temperature and other conditions. Lithiumamideis formed by the action of ammonia on amorphous lithium nitriciea t 130-350°, or on crystalline lithium nitride a t 410430°, or onlithium hydride a t 440-460°, thus:Li,N + 2NH, = 3LiNH, or LiH + NH,= LiNH, + El,.At 450° hydrogen reacts with lithiumimide according to theequation :2H2 + 3Li2NH= 2Li,NH, + NH,,The trilithiumamide when heated to 600° in a stream of nitrogenreacts according to the equation:4Li,NH2 + N2 = 6Li,NH + H2.Ruff and Martin10 have prepared metallic vanadium in a highstate of purity. A mixture of vanadium trioxide and carbon aremoulded with starch into rods, and these are sintered in an electricfurnace a t 1750°, and finally fused in the arc.The product contains95 to 97 per cent. of vanadium. Vanadium carbide can be preparedHonatsh., 1912, 33, 63 ; A., ii, 253.lo Zeitsclb. aizoyy. Chm., 1912, 25, 49 ; A., ii, 16G1 NOEGAN IC CHERIISTKY. 69in the resistance fnrnace. It is silvery-white, highly crystallino,and very hard. It melts a t 2750O. This carbide if powdered andmixed with the trioxide and a little starch solution, and thenheated to 1950O in a zirconia crucible, gives the fused metal, whichon analysis is found to contain 98 per cent.of vanadium and1-91 per cent. of carbon. The authors find that the pure metalmelts at 1 7 1 5 O .Renschler has shown that ammonium metavanadate can readilybe reduced electrolytically to tervalent vanadium salts. Thecathode is placed in a porous cell; both the anode and cathode arelead cylinders, and dip in 50 per cent. sulphuric acid. Ammoniumvanadate is added to the cathode cell, and the liquid well stirred,and a current of 4 amperes passed through until the solutionbecomes green. It is then removed and kept, when ammoniumvanadium alum separates in good yield.Group VI.Von Pirani and Meyer12 have determined tlie melting points oftungsten and molybdenum, finding that tungsten melts a t3100O +_ 60° and molybdenum a t 2450O +_ 30°.Ruder13 has studied the action of acids and alkalis on wrongbttungsten and molybdenum.He finds that both metals are some-what resistant t o acids owing to the formation of a coating of oxide.Tungsten is most rapidly attacked by fuming sulphuric acid, butonly 1.2 per cent. dissolves in eight hours. Molybdenum is moreeasily attacked than tungsten, but it is fairly resistive to concen-trated hydrochloric acid below 125O, and is not affected by hydro-fluoric acid. The metals are not attacked by aqueous potassiumhydroxide, but are slowly dissolved by fused alkali.Sanger and Riegel14 have succeeded in preparing pyrosulphurylchloride and chlorosulphonic acid in the pure state.I n the pre-paration of the former a mixture of fuming sulphuric acid andsulphur trioxide is added gradually t o an excess of carbon tetra-chloride in a heated flask, when the following reaction takes place :but some chlorosulphonic acid is also formed a t the same time.The liquid is purified by repeated fractional distillation off sodiumchloride.The pure pyrosulphuryl chloride boils a t 152.5-153O/760 mm.2s0, + CCl, = coc1, + S,O,Cl,,2 c i M i . Elcktrochem., 1912, 18, 137 ; A!., ii, 356.Her., 1912, 14, 426 ; d., ii, 560.l3 J. A?ner. Chem. Xoc., 1912, 34, 387 ; A., ii, 454.l.4 Proc. dmer. Acad., 1912, 47, 673 ; Zcitsch. nnorg. CJLCIL, 1912, 76, 79 ; / I . ,ii, 75270 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Chlorosulphonic acid is obtained by passing dry hydrogen chlorideinto a mixture of sulphuric acid and sulphur trioxide, the mixtureis distilled in a stream of hydrogen chloride, and the fractionpassing over between 145O and 160° is collected.It is purified byfractional distillation a t low temperatures. It boils a t 151--152O/765 mm. and a t 74--75O/19 mm. The two compounds may readilybe distinguished, as powdered selenium or tellurium give colourswith chlorosulphonic acid and not with pyrosulphuryl chloride.Group VZZ.A further investigation into the reactions of bleaching powderhas been carried out by Taylor and Bostock.16 When bleachingpowder and thirty times its weight of water is distilled withsulphuric acid, hydrochloric acid, or nitric acid in quantity slightlygreater than is necessary t o neutralise the free lime present, hypo-chlorous acid, and a small quantity of chlorine are evolved.Whenthe quantity of acid is sufficient t o neutralise all the free lime andto decompose all the hypochlorite theoretically present, the propor-tion of chlorine evolved is considerably greater. With more acidthe quantity of chlorine is still further increased until finallynothing but chlorine is evolved. There is no marked differencebetween the results obtained with each of the three acids present.Acetic and phosphoric acids are very much alike in their action,but they differ considerably from the mineral acids in theirbehaviour to bleaching powder.Even with large amounts of theseacids the proportion of hypochlorous acid does not fall much below50 per cent. When bleaching powder is distilled with boric acidand sufficient water, almost pure hypochlorous acid is produced.There is very little difference, even if three parts of boric acid areemployed to one of bleaching powder. The aut.hors suggest thisas a very convenient method for the preparation of aqueous hypo-chlorous acid.If carbon dioxide is bubbled through a mixture of bleachingpowder and water at the ordinary temperature nothing but chlorineis evolved; when, however, the solution is warm, hypochlorous acidcomes off in an amount increasing with the temperature, untilwhen the mixture is boiled hypochlorous acid is evolved practicallyfree from chlorine.Higgins16 has contributed a further important paper on theprocess of bleaching, and he finds that the action is due to bothhypochlorous acid and hypochlorites. Since the former is lessstable than the latter i t possesses a greater bleaching effect.Henceany agent which by hydrolysis increases the amount of the freeacid in solution tends to increase the efficiency of that solution.l5 T., 1912, 101, 444. Ibid., 222INORGANIC CIIEMISTKY. 7 1Willard 17 has prepared pure perchloric acid dihydrate,HC10,,2H2O, from ammonium perchlorate by oxidation of theammonia with aqua regia. The acid has the advantage of beingvery cheaply prepared in the pure state. It is not poisonous orexplosive. As a rule it is non-oxidising except a t the boiling point(203O). It will completely displace hydrofluoric, nitric, hydro-chloric, or any other volatile acid, owing t o its high boiling point.I t s salts are soluble in water, alcohol, or acetone, and are verysuitable for electrochemical work as they are not reduced. Itsprincipal use is for the separation of sodium and potassium.Furthermore, it serves as an excellent standard solution in acidi-metry, and it may be used in place of sulphuric acid in potassiumpermanganate titratioas.Group VIZI.Hantzsch 18 has put forward a suggestion regarding the constitu-tion of the blue and red cobalt hydroxides. It is generally thoughtthat the blu0 compound is a basic salt, for when it is precipitatedfrom the sulphate by alkali and washed with cold water until nomore sulphuric acid comes out it still contains SO,.Hantzsch states that this may be removed by repeated boilingwith air-free water, without the d o u r being impaired. The redhydroxide is obtained by precipitating with excess of alkali, andwashing the precipitate with hot water in an atmosphere ofhydrogen, and giving it a final washing with alcohol and ether.It still retains some water after prolonged heating in an atmo-sphere of nitrogen a t 300°, whilst the blue compound is completelydehydrated a t 170O. Acetyl chloride and benzoyl chloride reactmore vigorously with the red compound than with the blue.Hantzsch calls this a case of chromoisomerism, and he suggeststhe formula Co(OH), and COO . . . H,O for the red and bluecompounds respectively.Recoura l9 discusses the constitution of ferric sulphate trihydrateand ferric fluoride hexahydrate. I f ferric sulphate hexahydrateis dehydrated a t 108O i t loses three molecules of water, and isconverted into the yellow Fe2(S0,),,3H,0. This substance whendissolved in alcohol gives no precipitate with barium chloride.The alcoholate, Fe,(S04)3,2H,0,2C,H,0, previously described,20I7 J. Aqncr. Chem. Xoc., 1912, 34, 1480 ; A., ii, 1163.Zcitsch.. nnorg. Chcnt., 1912, 73, 304 ; A., ii, 166.l9 Compt. rend., 1911, 153, 1223 ; 1912, 154, 655 ; A , , ii, 165, 353 ; BuU. SOC.20 Ann. Chim. Phys., 1907, [viii], 9, 263 ; Compt. rend., 1907, 144, 1427 ; A . ,chim., 1912, [iv], 11, 370, 941.1907, ii, 552, 69372 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.loses half of its water a t 1 0 5 O without changing its appearance,whilst the remainder is lost together with the alcohol at 115O, thematerial becoming txmporarily black. The alcohol molecules do notappear to be attached to the sulphuric acid as they are removedon solution in water, unlike the case of ethyl ferrisulphate. Recourasuggests for the trihydrate the formula Fe,( S0,)3(0H),, similar tothat of the green pentahydrate of chromic sulphate. He considersthat the formula of ferric fluoride hexahydrate should be writtenFe2F,(OH),,(HF),,4H20, and for this he advances the followingreasons. Only a third of the iron reacts with barium fluoride,although the phenomenon is complicated by the precipitation ofthe double salt, Fe,F6,3BaF,. When the solid salt is boiled withalcohol only one-third of the fluorine is rapidly eliminated ashydrogen fluoride, the remainder being lo& very slowly. Whenheated to 9 5 O the salt loses water rapidly and proportionally to theloss of fluorine, until one-third of the latter has been eliminated,after which no more water is lost.E. C. C . BALY

ISSN:0365-6217    

DOI:10.1039/AR9120900036

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

ORGANIC CHEMISTRY.PART I.-ALIPHATIC DIVISION.A CAREFUL survey of the research work in the Aliphatic Divisionof Organic Chemistry done during the past year shows that prac-tically all the investigations have been carried out along more orless well-known lines, and that no strikingly original discovery hasbeen made. The work nevertheless represents a steady advance inthis section of Organic Chemistry.Hydrocarbons.Pring and Fairlie1 find that a t a temperature of 1200O and a tpressures from 10 to 60 cm. carbon and hydrogen unite to give,not only methane, but also ethylene, the rate of formation of thelatter being about 1/100th that of the former. The rate of forma-tion of ethylene increases with rise of temperature, and a t 1400Othe amount of this gas is comparable with that of the methane.The amount of acetylene formed a t 1650O was sufficient t o enableits presence to be experimentally demonstrated, but at 1200O theamount was insufficient for this purpose.I n a later communication 2 i t is shown that the rate of formationof methane from its elements proceeds with increased velocity a thigh pressures, the equilibrium stage being reached in two hours,when the temperature was 1200-1300° and the pressure 30 to 50atmospheres.The relative amount of methane produced increasedwith the pressure t o the extent demanded by the law of mass actionas applied to the equation G'+ 2H,=CH4. Methane is the onlysaturated hydrocarbon formed a t any temperature between l l O O oand 2100O or pressure up to 200 atmospheres.It is probable thatby using finely divided carbon and working a t high pressures thedirect unioc of carbon and hydrogen would be sufficiently rapidto enable this method to be used for the preparation of methaneon a large scale.T., 1911, 99, 1796; Ann. Report, 1910, 102.Ibid., 1912, 101, 91.774 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Hauser and Herzfeld3 find that ozonised oxygen reacts a t theordinary temperature with methane to produce formaldehyde,CH, + 20, = CH20 + H,O + 20, and that the reaction is practicallyquantitative even for low concentrations of the reacting substances.Since methane is the only hydrocarbon which is in this mannerdirectly oxidised to formaldehyde, the reaction may with advantagebe used for the detection of this gas.This action of ozone onmethane affords an explanation of GrBhant’s observation 4 thatmethane fires much more easily with oxygen obtained by electro-lysis than with ordinary oxygen.A study 5 of the action of acetylene and of substituted acetyleneson cuprous chloride shows that the initial product of the action isthe compound C,H,,ChCI, or C,HR,CuCl. Hence the equationCRICH + CuCl= CRICCLZ + HCI fails to show that the formationof an additive compound of the reacting substances is the firstphase of the reaction, and precedes substitution.Berthelot’s experiments on the pyrogenic condensation ofacetylene have been repeated 6 on a large scale and under carefullycontrolled conditions. The acetylene was diluted with an equalvolume of hydrogen in order to minimise its decomposition intomethane and hydrogen, and the mixed gases passed through twoelectrically-heated tubes, the first of these being maintained at640-650°, and the second at 800O.The resulting t a r was of alight brown colour, had an aromatic odour, and in one experimentamounted to 63 per cent. of the weight of the acetylene used; thegases leaving the apparatus contained a considerable amount ofmethane. The tube heated a t the lower temperature gave a tar richin light oil, whereas that obtained from the other tube containedmore of the hydrocarbons of high molecular weight. The followinghydrocarbons were obtained from the tar by fractional distillation :benzene, toluene, diphenyl, naphthalene, anthracene, indene,fluorene, pyrene, and chrysene, the first-named forming aboutonefifth of the whole tar.No styrene could be found, and thesubstance which Berthelot isolated and regarded as styrene wasin all probability indene, the properties of these two substancesbeing very similar. The low percentage of acetylene in ordinarycoal gas is regarded as due to its decomposition into methane andcarbon, and also t o its condensation to cyclic hydrocarbons; in fact,the formation of the latter during the manufacture of coal gas is ina large measure due to this condensation, although it is true thatBey., 1912, 45, 3515 ; A . , 1913, ii, 77.Conapt. revad.: 1907, 145, 625 ; A., 1907, ii, 990.W. Manchot, J. C. Witliers, and H. C. Oltrogge, Annalcn, 1912, 387, 257 ;A., i, 230.6 R.Meyer, Ber., 1912, 45, 1609; A., i, 525ORGANIC CHEM ISTRY. 75Pictet and Ramseyer 7 have isolated hexahydrofluorene from coalitself.The compound 5Na,S,03,5Cu2E$0,,5Cu,C,,C,H2,10H,0 is obtainedas a red precipitate by passing acetylene into a solution of sodiumthiosulphate and copper acetate.8 It burns like gunpowder whenheated, and dissolves in water, giving a red solution, the colour ofwhich is destroyed by acids and restored by alkali only if the latteris added immediately after the removal of the colour by the acid.Caoutchouc.-W. H. Perkin 9 has published an account of thework which he and several collaborators have carried out in thedirection of the preparation of synthetic rubber by methods whichmay ultimately admit of commercial application.A careful con-sideration of the question showed that for a process to be a com-mercial success it must be capable of producing the rubber a t2s. 2d. per kilo. [Is. per lb.], or even less. This limits the choice ofraw materials t o substances such as wood, starch or sugar, petrol-eum, and coal, and of these, starchy substances would appear to holdout the most hope of success. These considerations led to experi-ments on fuse1 oil, and as a result a method was devised by whichisoprene can be obtained readily and in quantity from isoamylalcohol. Commercial fuse1 oil on distillation gives a fraction (b. p.12&130°) which consists approximately of 87 per cent. of isoamylalcohol and 13 per cent.of active amyl alcohol. This fraction wasfirst converted into the chloride by the action of dry hydrogenchloride, and then chlorinated in a special apparatus designed forthe purpose, and with the object of limiting as far as possible thechlorination to the formation of dichlorides. The resulting product'on fractional distillation gave y&dichloro-B-rnethyIbutane,C'HMe,*CHCI*CH,Cl,fl&dichloro-fl-methylbutane, CCYMe,*CH,-CH,Cl, and a8-dichlorefl-methylbutane, CH,Cl*(,'BRMe*CH,*CH,Cl. In subsequent experi-ments these isomerides were not separated, and the portion of thechlorinated product which boiled a t 140-180° was passed oversoda-lime a t 470° and the resulting vapours condensed. The liquidthus obtained was fractionally distilled, and yielded isoprene in a40 per cent.yield of that theoretically possible. The formation ofisoprene from y&dichlorclB-methylbutane is no doubt due to amolecular rearrangement of the isopropylacetylene, CHMe,*CICH,which is first formed. I n order to polymerise the isoprene to rubberit was sealed up in tubes with about 3 per cent. of thin sodium7 Ber., 1911, 44, 2486 ; A . , 1911, i, 850 ; also B L I ~ ~ C S S ant1 Wlieeler, T., 1911,* K. Bliaduri, Zeitsch. nnorg. Chcm., 1912, 76, 419 ; A., i, 597.9 J. SOC. Chin. Ind., 1912, 31, 616; A., i, 636.99, 64976 ANNUAL HEPOK'I'S ON THE PROGRESS OF CHEMTS'l'KY.wire (Matthews' sodium process), and heated for several days a tabout 60°; the dark brown product was then treated with acetone,and the precipitated rubber washed with alcohol or treated withsteam to remove acetone and any unpolymerised hydrocarbon.Metallic sodium is a very effective agent for the polymerisation ofsuch hydrocarbons as isoprene, butadiene, etc., as its action ispractically quantitative, and is not seriously affected by thepresence of other hydrocarbons which do not polymerise to rubber.Perhaps the greatest difficulty which the above process offers toits being employed on a manufacturing scale is the limited supplyof fusel oil, and in order to overcome this difficulty Fernbach10worked out fermentation processes by which, not only this substance,but also acetone can be obtained much more cheaply.Moreover,the fusel oil obtained by Fernbach's method contains a large pro-portion of butyl alcohol, from which butadiene is readily obtainedby submitting i t to a process similar to that employed for thepreparation of isoprene from isoamyl alcohol.The resultingAmy-butadiene on treatment with sodium yields a rubber of betterquality than that obtained from isoprene.llI n the third method worked out, acetaldehyde was treated withvery dilute potassium carbonate, and the resulting aldol reducedby neutral reducing agents or electrolytically, when ay-butyleneglycol was obtained. This glycol on treatment with hydrogenchloride gave the corresponding dichlorobutane, from whichbutadiene was obtained by the soda-lime method.The product obtained by the polymerisation of vinyl bromide,and known as caouprene bromide,lZ exists in three modifications,a -+ /3 -+ y, which are capable of change in the direction indi-cated when submitted to the action of ultraviolet light or boiledwith anhydrous acetic acid.Harries' butadiene-caoutchoucbromide,l3 which also exists in three modifications, is either identi-cal or isomeric with caouprene bromide, the isomerism being dueto a difference in the distribution of the bromine in the molecule.The constitution of caouprene bromide is most probably expressedby the formula:$X€,-CHEr-CH2--CHBr -CH,-yHBrCHBr*CH2*CHBr*CH2 - - - - CH2-CHBr'in which the dotted lines represent an unknown number of*CH,*CHBr* groups.Both caouprene bromide and butadienecaoutchouc bromide yieldlo Eng. Pcct. 15,203, June 29, 1911 ; zbM., 16,925, July 24, 1911.11 Harries, A m a h , 1911, 383, 157 ; A ., 1911, i, 798 ; Ann. llcporrt, 1911, 108.l2 I. Ostromisslensky, J. Russ. Phys. Chcnt. Soc., 1912, 44, 204 ; A , , i, 280.Annalen, 1911, 383, 157; A , , 1911, i, 798ORGANIC CHEMISTRY. 77the same caoutchouc when treated with zinc dust, this reactioncompleting a new synthesis of butadiene-caoutchouc :CH,:C’HBr -+ caouprene bromide _“& butadiene-caoutchouc.A large number of processes have been worked out for thepreparation of unsaturated hydrocarbons like isoprene, butadiene,etc., which admit of polymerisation to caoutchouc-like substances,and in the majority of cases these have been patented. No usefulpurpose would be served by the publication in this report of allthese various processes, because unless they eventually admit ofcommercial application the great majority of them are of littleinterest.Caout.chouc when treated with ozone free from oxozone gives thetrua diozonide, C,,H,,O,, whereas crude ozone gives the dioxozonide,C,,H,,O,, which is more soluble than the true diozonide.14 Bothozonides on hydrolysis give lmdinaldehyde and lzvulic acid, inthe proportion of 4 to 3 in the case of the diozonide, and 2.8 t o 4for the dioxozonide. Synthetic rubber gives results similar to thoseobtained with natural caoutchouc.Spence 15 and his collaborators have continued their investigationon the vulcanisation of caoutchouc.They regard as “ free ” sulphurthat portion 6f this element which is extracted from vulcanisedcaoutchouc by acetone or hot sodium hydroxide solution, the undis-solved portion being the “fixed” sulphur.From the results oftheir experiments they conclude that it is possible to vulcanisecaoutchouc SG that no “free” sulphur is present in the product,the process under these conditions being essentially a chemical onewith the formation of a product which in composition agrees closelywith that required by the formula (TlOH,,S,; this view that vulcan-isation is a chemical process is in direct opposition to the adsorptiontheory. With regard to the “ free ” sulphur present in vulcanisedcaoutchouc part only is adsorbed, the remainder being in the non-adsorbed condition. With good specimens of caoutchouc there ispractically no vulcanisation a t 40°, and only very little at 60°, butabove this temperature it increases rapidly.On the other hand,partly decomposed caoutchouc undergoes considerable vulcanisationa t 40°.Bary and Weydertl, are of opinion that the reaction of vulcan-isation of caoutchouc is a reversible one, but the numericaldata obtained are not in agreement with the law of massaction, whatever hypothesis may be adopted as to the degreeI5 I). Speiicc, Zcitsck. Chcin. h d . Kolloide, 1911, 8, 304 ; 9, 83, 300 ; 1912, 10,C. Harrics, Ew., 1912, 45, 936; A., i, 407.299 ; 11, 28 ; A., 1911, i, 657, 801 ; 1912, i, 123, 638, 706.Coiqx. ~ e 7 ~ c l . , 1911, 153, 676 ; A., 1911, i, 100378 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of polymerisation of the hydrocarbon. In the process of vulcan-isation the sulphur first becomes attached to the terminaldouble linkings of a chain, and any further vulcanisation canonly occur after depolymerisation.Bary 17 has obtained anapproximate value for the molecular weight of caoutchouc ; thus,when sulphur is added to caoutchouc in quantity insufficient forvulcanisation of the whole of the caoutchouc, and the mixturesuitably heated, the resulting product consists of the sulphide(ClOHI6)& and caoutchouc ; the former is insoluble in cold benzene,whereaslthe latter dissolves in this solvent. By gradually increasingthe proportion of sulphur in success?ve experiments a point isreached a t which there is just sufficient sulphur to convert thewhole of the caoutchouc into the compound (c!l()H16)&; in thesecircumstances the whole of the product is insoluble in benzene.Analysis of the compound thus produced shows that it containsThis 2.5 per cent.of sulphur, from which n=value of n, is in fair agreement with Weber's formula, C,,H,,S,,and it would thus appear that the molecular weight of caoutchouca t the temperature of vulcanisation (140O) is approximately 2720.Beadle and Stevens 18 have shown that the nitrogenous substancepresent in Para rubber plays an important part in the process ofvulcanisation. Natural rubber from which this protein has beenremoved vulcanises less readily, and combines with less sulphurthan the same specimen in which the protein is present. Althoughthe protein-free rubber is much more distensible than the other,yet its tensile strength is much less.The absence of protein fromsynthetic rubber no doubt renders it inferior to the naturalproduct; even if a protein is added to the synthetic rubber it isvery unlikely that it will be possible to give it the reticulatedstructure so characteristic of the protein in the natural product.I n a lecture delivered before the Verein Deutscher Chemiker atFreiburg in Breisgau, Harries dealt with synthetic caoutchoucfrom the scientific point of view, and in a second lecture byHofmann the same subject was treated from the technical side.19A series of articles by I. L. Kondakoff on '' Synthetic Rubber, itsHomologues and Analogues," have appeared during the currentyear in the Revue Ge'ne'rale de Chimie.l7 Compt.rcnd., 1912, 154, 1159; A . , i, 481.1912, 4, 554; J. SOC. Chem. Id., 1912, 31, 1099.97.5 x 32 x 2 =18.4.2.5 x 136Zeitsch. Chem. Ind. KoZZoide, 1912, 11, 61 ; A . , i, 789 ; Jndiu-ruhber Joiwn.,Zcitsch. angezu. Cliem,, 1912, 25, 1457, 1462 ; A . , i, 706ORGANIC CHEMISTRY. 79Alcohols and Aldehydes.The action of dry potassium hydroxide on various alcohols hasbeen studied by Guerbet,20 who finds that when a primary alcoholcontaining six or more carbon atoms is heated a t 230° with potass-ium hydroxide it is oxidised to the corresponding acid, the yieldbeing almost quantitative; with a lower primary alcohol the yieldof acid is less, because a considerable amount of unsaturated hydro-carbon is formed. When a secondary alcohol is submitted to asimilar treatment very little is oxidised, the greater portion con-densing to higher alcohols, thus : isopropyl alcohol gives &methyl-pentan-5-01, CHMe2*CH,*CHMe*OH, and fi&dimethylheptan-y-ol,CH31e2*GH2*C"HMe*CH2*CHMe*OH. Tertiary alcohols are scarcelyattacked by pocassium hydroxide a t 230°, but above this tempera-ture they are slowly oxidised t o acids containing fewer carbonatoms.The above reaction is suggwted as a simple method fordistinguishing between primary, secondary, and tertiary alcohols.Senderens21 has published a full r6sum6 of the work done byhimself and others on the catalytic dehydration of alcohols byvarious elements, oxides, and salts ; the comparative efficiency ofseveral catalysts being given in a tabular form.The mechanismof t.he reaction is discussed, and the view favoured is that a com-pound of the catalyst and the alcohol is first formed, and that thissubsequently decomposes. I n view of the fact that the majority ofthe work has already been dealt with in previous reports,22 thisshort notice of the present publication will be sufficient.The formation of unsaturated hydrocarbons from alcohols bymeans of sulphuric acid has been shown t o be greatly facilitatedby the presence of such a catalyst as anhydrous aluminiumsulphate,23 and the results of an inquiry as to whether the sulphuricacid itself acts as a true catalyst or merely in virtue of its powerto absorb water, point to the former alternative being the correct0118.24 For every catalytic action there is a definite temperature,below which the effect of the catalyst does not come into play.Fortertiary aliphatic alcohols and sulphuric acid this temperature isbelow the boiling point of the lowest member of the series; forsecondary alcohols it is below the boiling point of the C5 member;and in the case of the primary alcohols it is near that of the C,member ; hence all tertiary alcohols, secondary alcohols above the2o Compt. rend., 1911, 153, 1487 ; 1912, 154, 222, 713; A., i, 67, 154, 331.21 J. 13. Senderens, Ann. Chim. Phys., 1912, [viii], 25, 449 ; if., i, 406.y2 Ann Xeport, 1907, 75 ; 1908, 77 ; 1909, 76 ; 1910, 99.23 J. B. Senderens, Compt. Tend., 1910, 151, 392; A., i, 649; Ann. lieport, 1910,oA J.B. Senderens, ibid., 1912, 154, 777 ; A , , i, 331.100 ; J. B. Senderens and J. Aboulenc, Compt. rexd., 1911, 152, 1671 ; A . , i, 60080 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.C5 member, and primary alcohols above the Cs member readilyyield the corresponding unsaturated hydrocarbon when boiled with3 to 4 per cent. of their volume of sulphuric acid. In the case ofthe lower alcohols, as, for instance, ethyl alcohol, by using a largeexcesB of sulphuric acid the alcohol is prevented from boiling awaybefore the temperature at which catalytic action takes place isreached.The dehydration of alcohols can also be effected by the use oftoluenep-sulphonic acid 25 ; thus tert.-butyl alcohol is readily con-verted into isobutylene by heating with 1.7 to 5 per cent.of itsweight of the sulphonic acid.Senderens26 has shown that ketones are readily prepared bypassing the vapour of an acid or a mixture of two acids overthorium oxide heated a t 3 8 0 4 0 0 ° , and the principle of thismethod has now been extended to the preparation of aldehydes.27For this purpose a mixture of the acid and excess of formic acidis passed over titanium oxide at 250--3OOO. The formic acid isdecomposed into carbon monoxide and water, and the carbon mon-oxide reduces the other acid to the corresponding aldehyde:R*CO&C+H*C'O,E=R*CHO+ CO,+%O.The yield of aldehyde is quite satisfactory, varying from 50 percent, in the case of acetic acid t o 95 per cent. in the case of octoicacid.Romijn's 28 method for the estimation of formaldehyde is basedon the interaction of this substance and potassium cyanide, wherebythe reaction CH,O + ECN = CN*CH,=OK is supposed to take place.Kohn 29 obtained potmsium glycollate and hexamethylemtetramineas products of the interaction of these two substances when anexcess of formaldehyde was used.The action of potassium cyanideon formaldehyde has been recently reinvestigated by Polstorff andNeyer,30 who have identified ammonia, glycollic acid, iminodiaceticacid, and nitrilotriacetic acid as products of the interaction whena 25 per cent. aqueous solution of potassium cyanide and one ofabout 18 per cent. of formaldehyde are mixed at Oo, and themixture kept a t the ordinary temperature for twenty-four hours.The following equations represent the changes which take place :25 H.Wuyts, Bull. Soc. chini. Belg., 1912, 26, 304 ; A., i, 598.J. B. Senderens, Compt. rend., 1908, 146, 1211 ; 1909, 148, 927 ; 149, 213, 9951910, 150, 111, 702, 1336 ; A., 1908, i, 494 ; 1909, i, 286, 627 ; 1910, i, 11, 179,318, 489.27 P. Sabatier and A. Mailhe, ibid., 1912, 154, 561 ; A . , i, 238.28 Zeitsch. an$. Chem., 1897, 36, 18 ; A . , 1897, ii, 166.29 Monatsh., 1899, 20, 903; A . , 1900, i, 205.30 Ber., 1912, 45, 1905 ; A., i, 605 ; see also H. Pranzen, J. y?'. G'Iwm. 1912, [ii],86, 133 ; A., i, 677.ORCIANIC CHEMISTRY, 81KCN + CH,O = CN*CH,*OK.CN*CH,*OH + 2H20 = CO,H*CH,*OH + NH,.CN*CH,*OH + NH, = CN*CH2*NH, + H,O.NH,*CH,*CN + HO.CH2.CN -+ NH(CHz*CN), -+NH(CH,*CO,H),.A good yield of glycollic acid can be obtained by distilling withsteam the mixture of potassium cyanide and formaldehyde five toten minutes after mixing.An attempt 31 to determine the composition of the resin producedby the action of dilute alkali on acetaldehyde a t low temperatureshas resulted in the separation of the resin into two isomerides,C24H3606 ; these have been converted into chloro- and bromo-deriv-atives, but the form in which the oxygen is present has not yetbeen determined.Substances like acraldehyde which readily polymerise haverecently become of special interest in view of the preparation ofbaekelite and synthetic caoutchouc.I n the elimination of theelements of water from glycerol the hydroxyl group may comefrom a primary or secondary alcoholic group, and the changeswhich takes place may be formulated thus:NH,*CH,.CN + 2HO*CHz*CN--+ N(GH,*C;N),--,N(CH,*002H)3.OH*CII[OH* CH,* C( OH): CH 23 ++ OH *CH2*CO* CH, - -+ + CH,O + CH,-CHO (r)J.*,CH(OH)*CH,*OH[OH *CH,*CH:CH*OH] ++ OH*CH,*CH,*CHO -3CH,:CH*CHO (IT)Secondary alcoholic groups are dehydrated more readily thanprimary ones, and so in accordance with the above schemes theproduction of acraldehpde should be facilitated by the dehydrationof the glycerol a t a low temperature.Potassium hydrogen sulphateand the sulphates of aluminium, copper, and iron are suitablefor the dehydration, but unfortunately the acraldehyde contains a,considerable amount of sulphur dioxide; on the other hand, thesulphates of the alkaline earths and of the heavy metals yield anacraldehyde free from this impurity.Granular dehydratedmagnesium sulphate gives the best results, and by heating theglycerol with this substance a t 330-340° and in a special appara-tus, a yield of 60 per cent. of acraldehyde is obtained,32 as much asone kilogram having been prepared in one day. I f the temperatureis appreciably (30O) higher than the ane quoted then the acraldey1 T. Ekecrantz, Arkiv. Kenz. Min. Geol., 1912, 4, No. 2 7 ; A , , i, 778.32 A. Wolil and B. Mylo, Be?.., 1912, 45, 2046 ; A . , i, 677.REP.-VOL. 1X. c82 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,hyde contains a considerable amount of acetaldehyde formed inaccordance with scheme I.The preparation of aliphatic dialdehydes is always a matter ofconsiderable difficulty on account of the ease with which theypolymerise ; this difficulty is greatly increased when the dialdehydeto be prepared is also a hydroxy-compound, for hydroxy-aldehydesare very sensitive to acids and alkalis. Wohl and MyloF3 by theirpreparation of tartardialdehyde, have successfully overcome thedifficultiee associated with the preparation of a substance of thistype :EtMgBr + C,H, -+ BrMgCiCMgBr -$ (EtO),CH*CiC*CH(OEt), 2CH(OEt)jH +colloidal I platinumc (E t 0) ,CH C H( OH) CH (0 H) CH (0 E t )s y?!!CHO*CH(OH)*CH( OH)*CHO (A*)J%? (lI=tO),CH*CH:CH*CH(OEt),The unimolecular form of tartardialdehyde was obtained inaqueous solution only; this had a sweet taste, and on slow evapora-tion deposited needles which were sparingly soluble, and no doubtrepresented a polymeric form of the aldehyde.The needles hada bitter taste, and dissolved slowly in warm water, giving a sweetsolution, in which the aldehyde was present in a unimolecular form,as shown by cryoscopic measurements. When oxidised withbromine water the dialdehyde gives mesotartaric acid, a resultwhich indicates that the ethylenic acetal (A) has a cis-configuration.(EtO,),CH*CH:C)H-CH( OE t),,with very dilute sulphuric acid, the same authors34 have obtainedmaleic dialdehyde. This substance has a bitter, burning taste,and a strong, pungent odour not unlike acrolein or formaldehyde,but perhaps its most remarkable property is its yellow colour,which is even deeper than that of diacetyl.This depth ofcolour is remarkable in a compound with such a low molecularweight, and is, no doubt, due to the accumulation of double linlr-ings; and regarded from this point of view the formuke of maleicdialdehyde and p-benzoquinone are seen to be very similar :By the hydrolysis of the diacetal,CH:CH o:c<;H:c~>c:o c: o<cH; ,,>c:o.Acids, Acid Chlorides, am? Esters.The evidence in support of the view that addition precedes sub-stitution in organic compounds, especially those containing acarbonyl group, is gradually becoming more conclusive. Lapworth,Bb83 Ber., 1912, 45, 322; A., i, 161. y4 lbid., 1746. 3B T., 1904, 85, 30ORGANIC CHEMISTRY. 83some years ago, brought forward evidence in support of it by hisinvestigation of ths action of bromine on acetone, and furtherevidence in the same direction is supplied by the work of Dawsoii,Miss Leslie, and Powis 36 on the reaction between acetone and iodine,the results obtained leading these observers to the conclusion thatthe reaction takes place in three stages:CH3*CO*CH3 -+ CH2:C(OH)*CH, .. . . . . . (1)CH,:C(OH)*CH, + I, -+ CH,T.*CI(OH)*CH, . . . (2)CH,I*CI(OH)*CH, -+ CH,I*CO*CH,+HI . . . , (3)changes (2) and (3) being of relatively high speed in comparisonwith the primary isomeric change (1).The mechanism of the reaction for the preparation of a-bromeacids by th4 Hell-Volhard method is probably of the same nature,and may be formulated thus:OH Br2 IC*CH2*COC1 -+ IZ*CH:C<cl -+R*CHBr*COUl + HBr.R*CHBr*CO.Gr + HCI.R*CHBr*C-OH Pr\ClEvidence in support of the above scheme is furnished byAschan,37 who shows that the product of the action of bromineon various acid chlorides is a mixture of the brominated acidbromide and brominated acid chloride, in which the former p r edominates. A very similar result has been obtained by Smithand Lewcock38 in their investigation of the action of bromineon isobutyryl cliloride; in this case the brominated productconsisted almost entirely of a-bromokobutyryl bromide. Theevidence brought forward by Meyer,39 although leading to thesame conclusions, is based on entirely different considera-tions.Meyer points out that, according to Lapworth, if theprocess is one of direct substitution, then the reaction must bea bimolecular one, and its velocity must depend on the con-centration of both the acid and the bromine.On the otherhand, if enolisation first occurs (slowly) and is then followed byaddition (rapid) of bromine, etc., then the reaction is unimolecular,and its velocity is independent of the concentration of the bromine.Experiments on the action of bromine on malonic acid show thatthe velocity of the reaction is quite independent of the concentration of the bromine. Meyer also points out that the formation ofthe brominated acid bromide in the experiments of Aschan mayequally well be explained by the theory of direct substitution; in36 T., 1909, 95, 1864; 1912, 101, 1503.su Ibid., 2358 ; A., i, 826.37 Ber., 1912, 45,1913; A., i, 599.39 Ibid., 2864 ; A., i, 941.a 84 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.this case the hydrogen bromide set free reacts with the brominatedacid chloride :CH,*COCI ?$ CH,Br*COCl+ HBr = C€€,Br*COBr + IICljust as potassium bromide reacts with acetyl chloride to give acetylbromide and potassium chloride.Similar criticism can be appliedto the results obtained by Smith and Lewcock.Two new isomerides40 of oleic acid have been prepared fromricinoleic acid as a starting point. When this acid is reduced byhydrogen in presence of platinous hydroxide i t gives h-hydroxy-stearic acid; this latter acid when heated with hydrobromic acidyields a bromostearic acid, which by treatment with alcoholicpotassium hydroxide gives a solid and a liquid product. From thesolid product one of the isomeridea was isolated and identified asAA-oleic acid (m.p. 34-36O). The liquid product contained theother isomeride, which from its reactions is in all probabilityAK-oleic acid.The rate of absorption of halogens by unsaturated acids isundoubtedly dependent in some measure on the relative positionof the double bond and the carboxyl group; ordinary oleic acid,for instance, readily absorbs bromine, whereas the absorption ofthis element by A@-oleic acid is very slow. Further evidence insupport of this has been obtained41 .by the determination of theiodine values for undecenoic, crotonic, AP-hypogxic, and As- oleicacids; thus with AP-oleic acid the following iodine values wereobtained: 18.0 after thirty minutes, 37.7 after three hours, 76.2after twelve hours, 84.2 after twenty-four hours, and 86.8 afterseventy hours, the theoretical value being 89.7.It is suggestedthat the determination of the iodine value may help in locatingthe position of the double bond in an unsaturated acid.Fenton and Jones42 obtained oxalacetic acid (m. p. 180-184°)by the oxidation of malic acid with hydrogen peroxide in thepresence of ferrous iron, the acid being isolated from the reactionmixture by the addition of sulphuric acid and extraction withether. Wohl and Oesterlin 43 shortly afterwards obtained by adifferent method an acid having the composition and propertiesof oxalacetic acid, but melting a t 1 5 2 O ; it was shown later thatthe new acid when dissolved in sulphuric acid and extracted withether is converted into the acid melting at 184O. From a compari-son of their physical and chemical properties it was concluded thatthe two acids are geometrical isomerides, and that the acid meltingS. Fokiii, J.Ems. Phys. Chm. SOC., 1912, 44, 653 ; A . , i, 534.41 G. Poiizio a d C. Gastaldi, Gnzzettn, 1912, 42, ii, 92; A., i, 74s.4'L T., 1900, 77, 77.4J Ber., 1901, 34, 1139 ; A . , 1901, i, 365ORGANIC CHEMISTRY. 85a t 184O is hydroxyfumaric acid, the other being hydroxymaleicacid. When tartaric acid is oxidised in the presence of ferrousiron an acid, C,H,0,,2H20, is obtained, which, from its readinessto form an anhydride, etc., is regarded as dihydroxymaleic acid.44Fenton and Wilks 45 now show that the “ oxalacetic acid ” meltinga t 1 8 4 O can be directly transformed into “ dihydroxymaleic acid,”and point out that from this result it would appear that if “ t h espacial relations of the original molecule persist in the newproduct,” then the “oxalacetic acid” melting at 184O and“ dihydroxymaleic acid ” must have the same geometrical con-figuration; in other words, this is evidence in favour of ascribingthe fumaroid configuration to ‘I dihydroxymaleic acid.” Thisevidence cannot, however, be regarded as conclusive, for the resultcan be explained in other ways.The sub joined scheme summarises the various transformationswhich have been accomplished with these acids and other alliedcompounds :Malic acid Tartaric acid Glyceric acidOxalacetic acid 2% Dihydroxymaleic acid -+ DihydroxyacrylicI J.I ir2o2~e I l l ? $llzO,Fe +I1202F’clrcatacid ( 1 ) ? 1 \4&a I ’ d : y / G& . ” 3 P - L l T 2 1 / \: xGlyoxalone-4 : 5-dicarb- s * @2 Pyrazinedicarb-oxylic acid oxylic acidl&Glyoxalone Glycoll- Diliyclroxytartaric Mesoxalic Pyraziiiealdehyde acid sernialdehyde\ dc IJ. $ J. %Formaldehyde Hexoses Mesoxalic y’z Tartronic Glyoxal Glycolurilacid Fe acidDuring the last two years J. F. Thorpe46 and his collaboratot-shave published six important papers dealing with the constitutionof glutaconic acid and its derivatives. Glutaconic acid is knownin one form only, although the formula generally assigned to it,CO,H*@H,*C‘H:CH-CO,H, requires the existence of cis- and trans-44 H.J. H. Fenton, T., 1905, 87, 801.45 T., 1912, 101, 1570.46 F. B. Thole and J. F. Thorye, ibid., 1911, 99, 2187, 2204 ; JS. Flmd and J. F.Thorpe, ibid., 1912, 101, 856, 871, 1557, 1739 ; Ann. Beport, 1905, 91 ; 1910, 8986 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.modifications, but all attempts to obtain these have failed. Further,it has been shown that the a-alkylglutaconic acids,CO,H*CHR*CH:CH*CO,H,and y-alkylglutaconic acids, CO,H*CH,*C'H:CR*CO,H, are the samesubstances ; also, that a-methyl-y-ethylglutaconic acid,G'O,H*CHMe.CH:~Et*CO,H,and y-methyl-a-ethylglutaconic acid, CO,H*CHEt*CH:CMe*CO,H,are identical. To explain these facts, it has been suggested thatthe constitution of glutaconic acid is best represented by theformula CO,H*CH*CH[HJ*CH*CO,H, the hydrogen atom withinthe bracket being regarded as a mobile atom in equilibriumbetween the two neighbouring carbon atoms.An acid containingsuch a mobile hydrogen atom is termed a'mobile acid, and it isassumed that for every mobile acid there is a static stable statecalled the normal state, in which the tautomeric hydrogen atomis attached to the central carbon atom of the three-carbon system.Such an acid is called a normal acid, and its structure is similarto that of isophthalic acid.B B\9/ CO,Hy C- - C *CO,K B Y\9/ C0,H.C- -C*CO,HC H CHGlntaconic acid. isoPhthalic acid.Although the manner in which the free valencies of the twoterminal carbon atoms of the three-carbon system are combinedis left an open question, they are regarded as being on the samesides of the two terminal tetrahedrons, corresponding with themeso- or non-resolvable form, thus :HI--H.-- -I? CO, HThe normal acids are the so-called trans-modifications of theacids of this series.Attempts to prepare an anhydride from a mobile acid by theaction of acetyl chloride lead, not to an ordinary anhydride, butto an hydroxy-anhydride (11), which, on subsequent hydrolysis,yields, in the case of glutaconic acid itself, the normal form ofthe acid (I).Now, if formula (11) correctly represents the constitution of theanhydride formed by the dehydration (by acetyl chloride) of thenormal form of the acid, it is obvious that the first product ofhydration of this anhydride must be the acid (111), called thORGANIC CHEMISTRY.87labile acid. I n the case of glutaconic acid itself, only the normalform (I) is known, and the non-isolation of the labde form (111)YH- CO, H EH-CO dehydrationCH :C( OH) CH*CO,H( p 2YH >o t-s H * CO,KCH,*CO,H(111.) Labile acid(nnknown for glataconic acid).YHis accounted for by the supposition that a t the moment of itsformation from the hydroxy-anhydride, the initial momentum ofthe entering hydrogen atom is sufficient to carry it a t once intothe three-carbon system. If, however, the initial momentum isdecreased by the introduction of an alkyl group on one of thecarbon atoms, it is possible to cause the hydrogen atom to remainwithin the carbonyl system by effecting the hydration of thehydroxy-anhydride by strong alkali or dilute alkali in the presenceof casein.If, however, the hydrolysis is brought about by wateralone or dilute alkali without casein, then the normal acid results,Thus, for a-methylglutaconic acid, we have:vMo*CO,H-? p,a,ks~i alone CH*CO,HNormal acid,gMe* C0,HCH,. CO,HEMe--CO ailUte?I3 m. p 145-146".CH: C(0H) >O StroDGalkali(?= Hydroxy-anhydride, -2m. p. 74.5".Labile acid, m. p. 118".The labile acids are the so-called cis-forms of the acids of thisseries. It is evident that a labile acid should be capable ofexisting in cis- and trans-modifications, but in the case of thesimpler members of the series the very unstable character of thelabile acids causes them to pass into the stable normal form byall reactions which should give the fumaroid modification. Thestability of a labile acid, however, is greatly increased by thepresence of a heavy group attached t o one of the terminal carbonatoms of the three-carbon system, more especially if a methyl groupis also present attached t o the central carbon atom of the system;in other words, the labile form of a-benzyl-P-methylglutaconic aci88 AKNUAL 1tEPORl'S ON THE PROGRESS OF CHEMISTRY.might be sufficiently stable to admit of its isolation in both thecis- and trans-modifications.Bland and Thorpe 47 have conse-quently prepared this substance, and find that the labile acidwhich they obtain has the truns-configuration, and all attempts toget the corresponding cis-form have been unsuccessful :CH,Ph*#*CO,H CH,Ph *$*CO,HYHMe YMe -CH-CO,H CO,H* CH,The fact therefore remains that up to the present no labile formof a glutaconic acid has been obtained in both cis- and truns-modifications.The reactions of substituted glutaconic acids of thetype CO2H*CR,CH:CI-T*C0,H, in which there is no mobilehydrogen atom, are normal in all respects, and the isomerism ofthese acids is of the ordinary cis- and trans-variety, thus:Noririal acid, In. p. 148". tram-Labile acid, m. 1). 134".CO,H*CHCO,H* CR,*C 13cis-form.CO,H-EHCH CR,*CO,Htrans- form.If the dehydration of the substituted glutaconic acid,a-methylglutaconic acid, is effected by the use of phosphorus penta-chloride 48 instead of acetyl chloride, then the anhydride producedis the ordinary anhydride, CHGCHR' CH- CO 'O>O ; these ordinaryanhydrides, when distilled, are converted into the hydroxy-anhydrides :Aconitic acid may be regarded as a @-substituted glutaconicacid, and it follows, from what has been said about the glutaconicacids, that aconitic acid should exist in the normal form (I) andthe labile form (11); moreover, since it is a @-substituted acid, thestability of the labile form should be sufficient to admit of itsisolation.49-$lH*COzH EH*CO,HYH-CO,H $?*CO,H-CH*CO,H CH,* CO,H(I.1 (11.)Normal aconitic acid.When aconitic acid is treated with ordinary acetyl chloride,Labile aconitic acid.47 T., 1912, 101, 1744.4* F. Feist and G. Pomme, AnnaZen, 1909, 370, 61 ; A , , 1910, i, 9.49 N. Bland and J.F. Thorpe, T., 1912, 101, 1490ORGANIC CHEMISTRY. 89which always contains phosphorus trichloride, it is converted intothe normal anhydro-acid50 (IV), melting a t 76O, whereas if pureacetyl chloride be used, then the product is the hydroxy-anhydro-acid (111), melting a t 135O. That formula I11 correctly representsthe constitution of this latter substance is proved by t'he fact thatit gives an intense coloration with ferric chloride, behaves as adihasic acid, and on heating undergoes the following changes:heated just abovo -S/H*Co2H heated -+ -$ $!H-CO >O at 170" cH.c(oH)>~ its melting point2 H C0,Hf."--co ----CH*CO(111.) M. p. '135". (IV.) M. p. 76".Itacoiiic anhydride. Citraconic anhydride.When the normal anhydro-acid (IV) i s treated with strong alkalior dilute alkali in the presence of casein, it gives the ordinaryform (I) of aconitic acid (m.p. 19l0), whereas the hydroxy-anhydro-acid (111), when similarly treated, gives the Iabile form(11) of aconitic acid, melting a t 1 7 3 O .The labile acid is a comparatively stable substance, which,although exhibiting no points of difference from normal aconiticacid in respect of its salts, yet differs markedly from this acid inits behaviour on dehydration, since on treatment with pure ofimpure (containing phosphorus trichloride) acetyl chloride it iscompletely converted into the hydroxy-anhydro-acid. When boiledwith dilute hydrochloric acid, the labile acid is slowly convertedinto the normal acid.The reactivity51 of the acid dichlorides of fumaric acid and itshaloid derivatives is very much greater than that of the correspond-ing compounds of maleic acid.Thus, whereas all fumaroiddichlorides react almost instantaneously with aniline t o formanilides, and with methyl alcohol to form esters, the interactionbetween malenoid dichlorides and bases or alcohols is very muchslower, and in some cases requires days before it approaches com-pletion. This low reactivity of the malenoid dichlorides cannotbe due t o the proximity of the two *COCl-groups, for if this wereso, then s-o-phthalyl chloride should also act slowly, whereas experi-ments show that the opposite is the case. These differences inreactivity are explained by assigning a cyclic ketonic structure,R.Anschiitz and W. Bertram, Ber., 1904, 37, 3967; A., 1904, i, 972 ; com-pare Easterfield and Sell, T., 1892, 61, 1009.51 E. Ott, Anmlen, 1912, 392, 245 ; A., i, 82890 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.>0, t o the malenoid dichlorides, the reaction between * t C O*C*CCI ,these subs€ances and aniline being formulated thus :Rl'~-co>O + NH,Ph - Rl*~*C(oH)*NHPh >o -+ R, C* CCI, R, C--- CCI,R,*g*CO*NHPh + HC1R,*C*COCIthe remaining *COCl-group reacting in the usual way.Much evidence can be brought forward in support of this viewas to the constitution of the malenoid dichlorides, for instance,the aluminium chloride compound of chlorofumaryl dichloride isa yellow mass, melting a t 50°, and from which the chlorofumaryldichloride is regenerated by treatment with water a t 00.If,however, the yellow mass is warmed, its colour deepens, andeventually becomes reddish-brown ; the substance now melts a t 1000,and is the aluminium chloride compound of chloromaleyl dichloride,because it yields this substance on treatment with water. Thisdeepening in colour is in agreement with the formula now assignedto the malenoid dichlorides, since the aluminium chloride com-pounds of cyclic ketones are intensely coloured. The aluminiumchloride compound of chloromaleyl dichloride, when heated a t180-230°, gives carbonyl chloride as one of its decompositionproducts, a result which strongly supports the cyclic formula,especially as no acid chloride has hitherto been known to givecarbonyl chloride on heating. Further, the two carbonyl groupsbeing in conjugated positions in the fumaroid dichlorides, shouldconfer on these substances a degree of unsaturation much greaterthan that of the malenoid dichlorides, which have only one carbonylgroup, and this conclusion is proved to be correct by experiment.chloromaleyl dichloride has been obtained in two forms, whichcan be easily converted into one another, and this observationsupports the formula now assigned t o this substance, sincey-lactonea are frequently dimorphous.Lastly, the molecularvolume of chlorofumaryl dichloride exceeds that of chloromaleyldichloride by 4.4 units, which is in close agreement with thedifference calculated on the assumption that the latter compoundhas a cyclic structure.By the action of barium peroxide on an ethereal solution ofacetic anhydride, Clover and Richmond 69 obtained acetic peroxide,and showed that this substance in aqueous solution graduallyhydrolyses to molecular proportions of acetic acid and peraceticacid, and further, that the per-acid itself decomposes into aceticacid and hydrogen peroxide.These observers were, however,62 Amer. Chem. J., 1903, 29, 179 ; A . , 1903, i, 396ORGANIC CHEMISTRY. 91unable to isolate the peracetic acid. It is now shown63 that thereaction, R*CO*OOH + H,O ++ R*CO,H + H,O,, is reversible, andthat the reaction in the direction right to left is brought intoeffect by the use of such catalysts as sulphuric acid, nitric acid,etc.I n actual practice, the per-acid is best obtained by theinteraction of the acid anhydride and hydrogen peroxide in thepresence of sulphuric acid,(R*CO),O + H202= R*C02H* + R*CY)*OOR,and subsequent distillation of the mixture under diminishedpressure. The substance may also be conveniently prepared bydecomposing the mixed anhydride of boric acid and the organicacid with hydrogen peroxide,R(OAc), + 3H,02= 3Ac0,H + B(OH),.Peracetic acid is a clear, colourless, pungent liquid, soluble inwater, alcohol, ether, or sulphuric acid. I t s aqueous solution iscomparatively stable, but acids, alkalis, and salts hasten itshydrolysis to hydrogen peroxide and acetic acid. It is extremelyexplosive, and when slowly heated to llOo it explodes violently.It attacks the skin, and acts as a powerful oxidising agent, convert-ing aniline and ptoluidine into the corresponding nitroso-compounds, and manganese salts into permanganates.Per-propionic, perbutyric, and performic acids have also been prepared ;the latter is not stable a t the ordinary temperature, and couldonly be obtained as a 48 per cent. solution.Hydrochloric or hydrobromic acid is capable of convertingferricyanic acid into ferrocyanic acid 54 with evolution of chlorineor bromine, which proves that the reaction:2H4Fe(CN), + C1, + Aqc+2H3Fe(CN), + 2HCl+ Aq,is reversible. I f the halogen is removed as quickly as it is formed,and this may be done by means of silver for the chlorine, andphenol or chloroform for the bromine, then the whole of the ferri-cyanic acid is converted into ferrocyanic acid. Theoretical con-siderations lead to the conclusion that the precipitate obtained bymixing solutions containing equivalent amounts of cupric andferrocyanogen ions should have the same composition as thatobtained under similar conditions from cuprous and ferricyanogenions, and this is confirmed by experiment.65 The precipitateobtained from cupric sulphate and potassium ferrocyanide has aconstant composition only if one of the two components is in largeexcess; if the ratio CuS04: K,Fe(CN), is greater than 2.5, thena J.D'Ans and W. Frey, Ber., 1912, 45, 1845 ; A . , i, 601.51 C . Gillet, Bt~1.l. SOC. china. Be@, 1912, 26, 236 ; A . , i, 614.55 E. Muller, G .Wegelin, and E. Kellerhoff, J. pr. Chern., 1912, [ii], 86, 82A., i, 61492 ANNUAL XEPOKTS ON THE PROGRESS OF CHEMISTRY.the precipitate has the composition Cu”,Fd(CN),, but if the ratiohas a lower value, then the precipitate contains potassium as oneof its constituents.The electrolytic reduction of alkyl derivatives of ethyl aceto-acetate has been regarded hitherto as taking place in accordancewith the scheme :CH3*UO*CHR*CO,Et -+ CK3*C€12*CHK*CH,.A careful comparison of the boiling points of the hydrocarbonsresulting from these reductions with the boiling points of hydro-carbons of known constitution has led Tafel56 to the conclusionthat the reaction is not as expressed above, but that the methylgroup resulting from the reduction of the carbethoxy-group occursas part of the main chain and not as a side-chain.Thus, takingethyl isobutylacetoacetate, CH,*CO*CH(CO,Et)-CH,*CHMe,, as anexample, it should give, according to the old scheme, the hydro-carbon CH,*CH,.CH(CR,)*C~,*CHMe,, the boiling point ofwhich is 110°/763 mm. The boiling point of the product isolatedwas 117~5-118°/760 mm., which agrees with that of the hydro-carbons which would be formed according to the scheme nowproposed by Tafel:*CH,*CHz*CHz*CH2*CH2*CH<~~~ f- CH3*CO*$lH*CH2*C 11 <:;:B. p. 116‘/761 mm. Y--...- *CO,Et 3 7%--3 CH,-CH~~CH,~CH,~CK.CB,.C*‘H,B. p. 117*6”/760 nim.Wislicenus57 is of opinion that of the four known forms ofethyl formylphenylacetate only two are chemically individual ;these are: the liquid a-form, which is the enolic modification,OH*CH:CPh*CO,Et, and the solid y-form, m.p. about looo, whichis the enol-aldu-form, CHO*GPh:C(OH)*OEt. The other twoforms: the &modification (m. p. about 70°) and Michael’s modifi-cation (m. p. about 50°), he regards as mixtures of the a- andy-modifications. The modification melting a t about 70° has beenregarded hitherto as the true aldo-form, CHO*CHPh*CO,Et, butWislicenus’s view as to its composition is supported by Meyer,58who finds that the compound is entirely enolic. Michael 59 is alsoof opinion that the solid modification melting at about 70° is amixture, but recognises the existence of three forms of ethylformylphenylacetate : the a-ester, boiling a t 125--126O/9 mm.,56 Ber., 1912, 45, 437 ; A ., i, 234.57 Annalcn, 1912, 389, 265 ; A . , i, 623.Bs Ber., 1912, 45, 2843 ; A., i, 940.59 AnnuZen, 1922, 391, 235, 2 i 5 ; A., i, 861ORGANIC CHEMISTRY. 93&ester, melting a t about 40°, and the y-ester, melting a t aboutlooo.Michael's 60 statement that ethyl 1-methylcyclobutan-3-one-1 : 2 : 4-tricarboxylate (I) is formed by the condensation of ethyl citracon-ate with ethyl sodiomalonate in alcoholic solution is now 61 shownto be incorrect, the substance actually formed being ethyl CYC~O-pentan-2-one-1 : 3 : 4-tricarboxylate (11) :CH,. QH CO,E t C O , E t * ~ H - ~ O CO, Et*CH<CO,Et*CMe*CH*CO,Et CO-CH*CO,Et(I. 1 (11.)I f the condensation is carried out in such a manner that noconsiderable elevation of temperature occurs, then the product isethyl but ane-aj366-t etr acarboxylat e,CO,E t*CH,*CH(CO,Et)-CH,*CH(CO,Et),.This compound is, no doubt, an intermediate substance in theformation of the above cpclopentanone, and its production by thecondensation of ethyl citraconate and ethyl sodiomalonate is in allprobability due to the act)ion of traces of sodium ethoxide on theethyl citraconate, whereby it is transformed into ethyl ethoxy-methylsuccinate.This compound by the loss of alcohol gives ethylitaconate, CH,:C'(CO,Et)*CH,*CO,Et, which on condensation withethyl sodiomalonate, in the normal way, gives ethyl butane-apbb-t e t r acarboxylat e.The condensation of ethyl citraconate with ethyl sodiomalonatein ethereal solution has always been assumed to take place inaccordance with Michael's positive-negative rule.According toMichael, the negative portion, *CH(CO,Et),, of ethyl sodiomalon-ate should attach itself to that carbon atom in ethyl citraconate towhich the methyl group is joined, since this carbon atom, owingto the presence oi the methyl group, is more positive than the otherwhich has the hydrogen attached to it. The product would thus beethyl p-methylpropane-aa/3y-tetracarboxylate :C'0,E: t. C ,\I P C? 13 .CC E t -+ CII( CO, I3 t )2 C: Me( ('O,Ett)*C'H,* O,? E t,Thi; is now shown to be incorrect, and the compound actuallyformed when the condensation takes place in solvents like etherand benzene, which do not react with sodium, is ethyl butane-aafly-tetracarboxylate, (CO,Et),CH*CH(CO,Et)-CTHMe*CO,Et.Ruleslike the one enunciated by Michael are of little value in deter-mining the course of a condensation like the one under discussion.It seems much more probable that steric influence is the pre-dominating factor in condensation of this type, there being gener-ally great resistance to the formation of a quaternary carbon atom,Bw., 1900, 33, 3731 ; A., 1901, i, 123 ; Michael mid Schulthess, J. pr. Chem.,1892, [ii], 45, 55 ; A., 1892, i, 591. E. H o ~ J ~ , T., 1912, 101, 89294 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.more especially if the groups involved have a large molecularmagnitude.Curb ohydrat es.A new anhydride, anhydromethylglucoside, C,H,,O,, has beenobtained by Fischer and Zach 62 by warming triacetylmethylgluco-side bromohydrin with barium hydroxide solution.This anhydridedistils undecomposed a t very low pressure, forms a crystallinehydrate, and is not converted into sugar by emulsin, but acidshydrolyse it easily to a crystalline compound, C'6H1005, which isregarded as an intramolecular anhydride of dextrose, andprobably represents a new type of sugar derivative. It differsfrom the hexoses in that it restores the colour to Schiff's reagent,but strongly resembles them in many other respects, as, for instance,in its reactions with phenylhydrazine and alkalis, and in itsbehaviour on reduction and oxidation. The fact that the anhydro-sorbitol obtained from it is isomeric with styracitol, a naturallyoccurring substance isolated by Asahina 63 from Styrax obassia, isevidence in support of the view that the anhydrides of dextroseand of glucosides occur in nature.Anhydrogluconic acid probablyhas an OH group attached to its y-carbon atom, since it veryreadily forms a lactone; further, since the anhydrodextrose fromwhich it is derived forms an osazone, it follows that the onlyformulae possible for anhydrogluconic acid are limited to the threefollowing :CH,*CH*CH( OH)*CH(OH) CH (OH) *CO,H,I--() _ICH, * C H( OH) CH (0 11) CH C H( OH) CO,H,I -0 -1CH,(OH)*CH*CH( OH)*CH* CH(0H) *CO,H.I-_ 0-1Lack of material unfortunately prevented any definite conclusionbeing arrived a t as to which of these three formulae is the correctone.d-Glucosamine is the first well-defined carbohydrate compoundisolated from animal tissue, and although numerous attempts havebeen made to convert it into the corresponding hexose, these havehitherto proved unsuccessful.It is true that Tiemann 64 isolatedphenylglucosazone from it, but the osazone was obtained in asmall yield, and its melting point was inconclusive; further, theformation of the osazone still leaves open the possibility that62 Ber., 1912, 45, 456, 2068 ; A., i, 239, 678.G3 Arch. Pharm., 1907, 245, 325 ; 1909, 247, 157 ; Ber., 1912, 45, 2363 ; A.,1908, ii, 59 ; 1909, i, 288 ; 1912, i, 832.Ber., 1886, 19, 5 0 ; A., 1886, 329ORGANIC CHEMISTRY. 95glucosamine may be derived from mannose, and not from glucose.Attempts to eliminate the amino-group from glucosamine bynitrous acid or the silver nitrite method of Fischer do not lead t oa simple hexose, but to a hydrated furan derivative known aschitose.Now chitose also results from the dehydration of a hexose,and it was thought that if the bydroxyl groups in glucosamine weresubstituted the resulting compound would have its amino-groupremoved by the action of nitrous acid in the normal way, and thata derivative of the parent hexose would result. In the course ofan investigation based on the above considerations, Irvine andHynd66 obtained a methylglucosamine, which a t first appeared asif it might be identical with an aminomethylglucoside obtained byFischer and Zach 66 from dibromotriacetylglucose. If these twocompounds had proved to ba identical, this would have meant thedirect synthesis of glucosamine from glucose.A close comparisonof the properties of these two compounds has shown, however, thatthey are not identical, but isomeric, and it is concluded that themethylglucosamine prepared by Irvine and Hynd is a-aminomethyl-glucoside, whereas in Fischer’s aminomethylglucoside the amino-group may occupy the j3-, &, or €-position. As the conversion ofa-aminomethylglucoside (methylglucosamine) into methylglucosidecannot be carried out directly, it was methylated by the silveroxide reaction, and thus converted into a-dimethylaminomethyl-glucoside, from which the dimethylamino-group was removed byheating with barium hydroxide. As the resulting methylglucosidecould not b8 crystallised, it was completely methylated, and thetetramethyl methylglucoside purified by fractional distillation.The hydrolysis of this tetramethyl methylglucoside was effected intwo stages: the first stage gave tetramethylglucose, the identity ofwhich was proved by its melting point and specific rotation; andthe second stage gave d-glucose, which was also fully identified byits specific rotation, and the specific rotation and melting point ofits osazone.The conversion of glucosamine into glucose by Irvine and Hynd 137has thus been effected through the following reactions:d-Glucosamine hydrochloride (from chitin obtained from lobstershells) -+ bromotriacetylglucosamine hydrobromide -+ triacetyl-aminomethylglucoside hydrobromide -+ aminomethylglucosidehydrochloride -+ methylaminomethylglucoside -+ dimethylamino-methylglucoside -+ [methylglucoside] -+ tetramethyl methylgluco-side -+ tetramethyl glucose-+ d-glucose.The evidence is in favour of the view that no Walden inversion6b T., 1911, 99, 250.67 T., 1912, 101, 1128.66 Ber., 1911, 44, 132; A ., 1911, i, 17796 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.takes place during the series of changes which leads from d-glucos-amine to d-glucose, and that the former must consequently beregarded as a-amino&-glucose.Constitution of a-Aminomethylglucoside and i t s HomoZogue8.-The adoption of the formula1- 0--,NR2OH*CH,*CH(OH)*CH*CH(OH)* f: H*CH*OMe(where R=Me or H) for a-aminomethylglucoside and its N-alkylhomolopes is, generally speaking, in accord with the properties ofthese substances.Several objections, however, can be raisedagainst this formula; for instance, the very great difficulty withwhich it is hydrolysed, whereas such substances as a- and &methyl-glucosides, Fischer’s isomeric aminomethylglucoside, etc., are com-paratively easily hydrolysed. This resistance to hydrolysis is inti-mately connected with both the presence and position of thenitrogen atom as shown by the remarkabIe fact that when treatedwith cold dilute nitrous acid i t yields a product which has avigorous action on Fehling’s solution. The glucosidic part of themolecule thus seems to be affected whenever the amino-group isattacked.This points to the existence of a betaine-like structure in themolecule, thus :,-O-OH*CH,*CH (OH)-~H.CH(OH)-~: H-+H.N--0/ I \H H MeEvidence in support of this formula is afforded by the fact thatboth ammonia and methylamine are produced when the substanceis heated with sodium hydroxide.Only monohydric phenols have hitherto been used in the pre-paration of phenolic g’ucosides, although it is true that polyhydricphenols have been combined with sugars, but the products were ofa complicated nature, and were not ordinary glucosides.Fischerand Strauss 68 have now succeeded in preparing phloroglucinol-d-glucoside by shaking an alkaline solution of phloroglucinol withan ethereal solution of acetobromoglucose, and subsequent removalof the acetyl groups. This synthetic glucoside is identical withthe phloroglucinol-glucoside obtained by Cremer and Seuffert 69 bythe action of barium hydroxide on phloridzin, and both are hydrelysed by emulsin.Phloroglucinol-glucoide is of physiologicalinterest, because it is capable of producing diabetes. Resorcinol-Ber., 1912, 45, 2467; A . , i, 884. 63 Ibid., 2565 ; A,, i, 885ORGANIC CHEMISTRY. 97d-glucoside and 2 : 4 : 6-tribromophenyl-d-glucoside have also beenprepared by a similar method.The presence of maltose amongst the produck3 of acid hydrolysisof starch has been denied 'by early workers, but in recent yearsWeber and Macpherson 70 and others have demonstrated the presenceof as much as 20 per cent. and more of maltose in commercialglucose prepared by the acid hydrolysis of starch. This is nowconfirmed by Fernbach and Schoen,71 who have isolated and com-pletely identified maltosazone from the interaction of phenyl-hydrazine and the products of hydrolysis of starch mucilage byacids under pressure.These observers regard the processes ofhydrolysis of starch by malt diastase and by acids as essentiallyidentical, tho only difference being that in the former case thehydrolysis stops a t the maltose stage, whereas in the latter it goesa stage further.When the sugars dihydroxyacetone, erythrulose, lzvulose, sorbose,and perseulose in aqueous solution are exposed in quartz tubes tosunlight or ultra-violet light, they are decomposed into carbonmonoxide, a little carbon dioxide, and the alcohol correspondingwith the original sugar, but containing one carbon atom less.When starch in solution is exposed to X-rays it is converted intosoluble starch and dextrin.72The dehydration73 of starch in a vacuum containing phosphoricoxide shows that a t 2 5 O as much as 28 per cent, of the starch isconverted into water-soluble matber; this rises to 57 per cent.a t50°, and to 90 per cent. a t 1 2 0 O . The conversion of starch intodextrins is regarded as essentially a process of dehydration ratherthan hydrolysis, a supposition which is supported by the fact thata much better yield of dextrins is obtained when the starch isheated alone than when i t is heated with water. Starch is regardedas consisting of molecular aggregates or complexes of C6HI0O5,which are held together by water, thus:{[(CGH,,O,*OH)H],[(C,H,,O,*OH)J,H,- ,}H***.I n the process of dehydration the loss of water causes a breakingdown of these complex aggregates into simpler ones, and it is thusthat, the various dextrins result.Starch paste is converted by Bacillus macerans into substancesJ.Amer. Chew, Soc., 1895, 17, 312 ; A., 1895, ii, 296.Bull. SOC. chim., 1912, [iv], 11, 303 ; A., i, 336.7'J D. Berthelot and H. Gaudechon, Compl. rend., 1912, 155, 401 ; A . , i, 750 ;H. A. Colwell and S. Russ., PTOC. Physical SOC., 1912, 24, 217 ; A , , i, 608;J. Bielecki and R. Wurmser, Compt. re?<., 1912, 154, 1429 ; A . , i, 538 ; L. Massol,ibid., 1645 ; A., i, 538 ; J. Stoklasa, J. Sebor and W. ZdobnickJi, Biochem. Zeikclh.,1912, 41, 333 ; A., i, 606 ; W. Lob, ibid., 1912, 43, 434 ; A., i, 750.'8 G.Malfitano and Mlle. A. Moschkoff, Compt. rend., 1912, 154,443 ; A., i, 240.REP.-VOL. 1X. 98 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.completely soluble in water, and from these two crystalline dextrins,a- and 8-, have been isolated.74 The a-isomeride crystallises incolourless, hexagonal plates or lancetrshaped needles, has [a], +12P, and is doubly refractive ; determination of its molecularweight by the cryoscopic method gave values corresponding with(C6H1005)4, The P-isomeride crystallises in rhombic crystals, andhas [a]= + 1 3 6 O ; owing to its insolubility its molecular weight couldnot be determined. The generic term amylose is proposed for thepolysaccharides having the formula (CsHloOj)n.On acetylationthe a-isomeride gives a hexa-acetate, and the &compound gives anona-acetate, a result which shows that hydrolysis of the dextrinshas taken place simultaneously with the acetylation. These acetylderivatives on hydrolysis give respectively diamylose,and triamylose, (C6H,o05)3,4H20, each of which crystallises inneedles and does not reduce Fehling’s solution. The originala-dextrin is therefore tetra-amylose, and the 6-dextrin, from itsanalogous behaviour to the a-compound, is regarded as hexa-amylose,Gerber75 has shown that hydrogen peroxide, even in very dilutesolutions, is a very powerful agent for the hydrolysis of starch, theproducts being maltose and dextrins. I f concentrakd solutionsof the peroxide are used, the maltose is oxidised.Scyllite from the kidneys, etc., of certain plagiostomous fishes,quercine from acorns, and cocosite from Cocos plumosa and Cocosnucifera, are now shown to be identical, and it is proposed that infuture they should all come under the heading “ scyllitol.” 76 Theisomeric substance inositol has been obtained in two new forms:isoinositol and $-inositol.Harden and Young77 have published a detailed account of amethod by means of which glycogen free from nitrogen, yeast-gum,and pracGcaIly free (0.02 per cent.) from ash can be obtained fromyeast.Details are also given for the isolation of the yeast-gumfrom the glycogen mother liquors.When dry cotton78 is submitted to the action of ozone (2 percent.) a small quantity of carbon dioxide is evolved, and a celluloseperoxide and an acid derivative are formed; the properties acquiredby the cotton as a result of this treatment being very similar tothose possessed by cotton and linen which have been bleached byF.Schardinger, Centr. Bakt. Par., 1911, ii, 29, 188; A., 1911, i, 181 ;H. Pringsheim and A. Langhans, Ber., 1912,45, 2533 ; A., i, 832.Compt. rend., 1912, 154, 1543; A,, i, 538.(C6H1005)2,2H20,(CBH1005)6.76 H. Miiller, T., 1912, 101, 2383.77 ., 12, 101, 3928.78 Miss M. Cunninghain and C. Dorke, ihid., 497ORGANIC CHEMISTRY. 99chloride of lime and washed without the use of an '' antichlor." 79When the ozonised cotton is boiled with water or digested withalkali the acid derivative is removed, and the residual neutralproduct closely resembles the typical oxycelluloses.I n the indw-trial method of bleaching by alternate treatment with ozoneand bleaching powder, both the peroxide and the acid derivativeplay a part, the peroxide being decomposed by the bleachingpowder, and the acid derivative increasing the activity of thebleaching powder.When benzene is added to a solution of cellulose in sulphuricacid the hydrocarbon and the carbohydrate combine to form acompound which appears to have the composition C,H,O,Ph, ;toluene, xylene, and $-cumene also form analogous compounds, forwhich the generic term desoxyn is proposed. The carbohydrateresidue appears to enter the benzene nucleus in the para-positionrelative to the methyl group. Dextrose, like cellulose, also combineswith benzene to produce a desoxyn, for which two formulz aresuggested : (1) c6H,0,Ph,, representing the anhydride of dextrose,in which three hydroxyl groups are replaced by phenyl groups;(2) C,H,O,Ph,, according t o which the formation of the desoxynwould be represented by the equation:When a desoxyn is oxidised by permanganate i t gives the aromaticacid corresponding with its aromatic constituent, thus : phenyldes-oxyn gives 45 per cent.of benzoic acid, and tolyldesoxyn gives20 per cent. of terephthalic acid.80Mixtures of alcohols and ethers possess the property of dissolvingcertain varieties of nitrocellulose, although the latter compoundsare insoluble in either component. Baker81 has determined theviscosity of such mixtures, and concludes from his results that theycontain an ether-alcohol complex, and to this complex he atkri-butes the solvent power of the mixtures for nitrocellulose.Although the results show that dissociation of the alcohol,(R*OH)n 2 nR*OH,does take place, yet the function of the ether cannot be merelythat of a dissociating solvent. For if this were so, and assumingthat the solvent action is due to the non-associated alcohol, then itshould he possible to replace the ether by other indifferent liquidswithout decreasing the solvent power of the mixtures, a deductionwhich experience proves to be incorrect.Further, if the solventA. M. Nastukoff, J. Rws. Phys. Chcnt. Soc., 1902, 34, 231, 505 ; A., 1902, i,362, 747 ; Zeitsch. Farb. Ind., 1907, 6, 70 ; A., 1907, i, 413 ; A.M. Nastukofl'and1. I. Kotukoff, J. IZuss. Phys. Chem. SOC., 1912, 44, 1152; A . , i, 762.CCHIoOj + 2CGHG - 3H2O = C18H16O2.79 Cross and Bevan, Zc'itxh. nngczu. Chein., 1906, 19, 2101.I:, 1912, 101, 1409.I3100 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,action is dependent entirely on the dissociation of the alcohol, thenthe higher alcohols should prove better solvents than the lowerones, since they are less associated, whereas the opposite is the case.Nitrogen Compounds.Amines.-The new method for the separation of tertiary fromsecondary and primary asmines which has been worked out byHibbert and Wises2 is based on the instability of the additive com-pounds of the Grignard reagent with tertiary amines, and is, briefly,as follows: To the mixture of amines, either alone or dissolved inether, is added an excess of an ethereal solution of magnesium ethylbromide (or methyl iodide), and the ether distilled off.Theproduct is then heated in an oil-bath to 200-280° (dependingon the nature of the amine), whereupon the pure tertiary aminedistils over. The primary or secondary amine may be recoveredfrom the residue by addition of sodium hydroxide and steamdistillation.The results of an investigation83 of the action of acetyl chlorideon various organic bases show that in the majority of instancesan additive compound of the base and the acid chloride is theinitial product; this is certainly always the case with tertiary bases,and the compound formed has the composition R,N,CH,*COCl.This last statement is contrary to the view generally accepted thattertiary bases have no affinity for acid chlorides, and the compoundsnow described are the first of their kind.Zmino-compounds.-From the results of his researches on ‘‘ theformation and reactions of imino-compounds,” Thorpe 84 has formu-lated the following generalisations : (1) the imino-compounds reactwith sodium ethoxide in their amino-form only; (2) the 8-imino-derivatives of the ay-dicarboxylic esters are then derivatives ofglutaconic ester, and conform, as such, to the third generalisation;(3) compounds containing the complex X,C:CR*CH,X, in which Xmay be any negative group and R any univalent radicle or group,react with sodium ethoxide so as to retain the mobile hydrogenatom, and therefore yield sodium derivatives of the typein which the mobile hydrogen atom is hepresented by (*).Thereplacement of the sodium in this compound by an alkyl groupyields the alkyl derivative, X,C:CR*CHRX, and the action ofsodium ethoxide on this substance causes the replacement of themobile hydrogen atom, but the metal then takes up the mostX,C:CR&N~X,T., 1912, 101, 344.w W. M. Dehn, J. Amer. C’hem. Soc., 1912, 34, 1399 ; A . , i, 833. * T., 1912, 101, 249ORGANIC CHEMISTRY. 101negative position in the system, yielding the sodium derivative,X,CNa*CR:CRX. In certain cases the compound X,C:CR*CNaRXis also formed, but to a small extent only. The following may betaken as an illustration : CO,Et*CH(CN)*C'(NH)*CH,*C"O,Et reactsas CO,Et*C(C'N):C'(NH,)*CH,*CO&t, which with sodium ethoxideand methyl iodide yields first CO,Et*C(@N)X(NH,)*CHMe*CO&t,and then, by further action, a mixture of the two dimethyl deriv-atives, CO,Et*CMe(CN) C(NH,) :CMe*CO,Et andCO,Et*C(CN) :G'(NH,) *CMe,*CO,Et.d mides.---Storch,s5 by the oxidation of thiocarbamide, obtaineda substance having the constitutionNH,*C(:NH)*S*S*C( :NH)*NH,,which is named formamidine disulphide by Fichter and Wenk,86who have recently obtained it by the electrolytic oxidation of t h bcarbamide.The formation of this substance from thiocarbamidehas been regarded as strong evidence in support of the unsym-metrical formula, NEI,*C(:NH)*SH, for the latter. It is now shownby Werner87 that the formation of the formamidine by oxidationof thiocarbamide by means of nitrous acid only takes place in thepresence of a strong acid ioniser, such as nitric acid, sulphuric acid,etc.; and that if the oxidation be effected in the presence of aceticacid or other feeble acid ioniser, then the main product of thereaction is thiocyanic acid.To explain these and other factsWerner suggests a slight modification of the unsymmetricalformula for thiocarbamide, and proposes the formula HN:(TcT H3,which represents the result of a combination between the acidgroup, SH, and the basic group, *NH,, of the unsymmetricalformula. This formula affords an explanation of the capability ofthiocarbamide to form salts with the stronger acids only. Alsoweak acids would have no disturbing effect on such a compound,and the action of nitrous acid in the presence of a weak acid wouldbe represented thus :HN:C<?"S + HONO = HSCN + N, + 3H,O.On the other hand, a strong acid, HX, would first form the saltbs -..which would then react with nitrous acid to give formamidinedisulphide and nitric oxide.The formation of nitrogen in the firstcase and of nitric oxide in the second are in complete agreementwith experiment.85 Mon,ntslt., 1850, 11, 452 ; A. 1891, 548.86 Bcr., 1912, 45,1373 ; A . , i, 423.87 T., 1912, 101, 1167, 1982, 2166, 2180102 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.If the formula now proposed be accepted as representing theconstitution of thiocarbamide under normal conditions, that is, ina neutral solution or even in the presence of a weak acid, then anexplanation is afforded for the fact that thiocarbamide can glverise to products derived either from the symmetrical or unsym-metrical structure, thus :nSymmetrical.Norm a1 strut: t w e . Unsymmetrical.Dixon and Taylor 88 are of opinion that ‘ I thiocarbamide,”together with its monohydric substitution derivatives containinghydrocarbon radicles not attached to sulphur, has the configurationrepresented by the typical formula H,N*CS*NH,; so long, a t least,as these compounds remain in the static condition. They object tothe formula NH,*C(:NH)*SH, because a substance having that con-stitution would be (1) probably very unstable, (2) a stronglymarked base The cyclic modification of this formula proposed byWerner is, in tlie opinion of the writer of this report, free fromthese objections.The formation of carbamide from ammonium cyanate can nolonger be regarded as entirely due to isomeric change; nor to aninteraction between ammonium ions and cyanate ions, since ammon-ium cyanate in 90 per cent.alcohol is converted into carbamideabout thirty times as fact as when dissolved in water; further, puredry solid ammonium cyanate is readily transformed into ureawhen heated. The view that the carbamide results from the inter-action between free ammonia and free cyanic acid has been putforward by Michael and Hibbert,89 and is now supported by Chatta-way,M who regards the interaction between these two substances asdue to the tendency of the carbonyl group to add on groups suchas g>XH or R-OH.Chattaway formulates the reaction thus:NH,*N:U:O H*N:C:O+NH, Z HN:C<OH H,N*CO*NH,.NH2The formation of alkyl-carbamides from isocyanic esters, ofcarbamic esters from carbamide and alcohols, etc., can be explainedin a similar way.Wheeler 91 and others introduce the idea of partial valency to* 3 T., 1912, 101, 2502.T., 1912, 101, 170.y1 J. Amcr. Chem. Soc., 1912, W, 1269 ; A . , i, 752.8y Aiwt. Ikport, 1909, 70ORGANIC CHEMISTRY. 103explain the interaction of ammonia and cyanic acid, which theyexpress thus :H*N*C:OA ntino-acids.-The glycerides of amino-acids when obtained willfio doubt prove of great physiological interest, but all attempts toprepare these compounds have so far proved unsuccessful 92; thusglycerol and glycine do not combine when heated alone or in thepresence of hydrogen chloride or sulphuric acid, nor does silverglycine react with the monohalohydrins of glycerol. Bromoiso-valeric acid, sulphuric acid, and glycerol, however, interact whenthe mixture is heated at 70--80° to give bisbromoisovalerylglycerol,OH-CH(G'R2*O*C0.C,H,Br),, and it was thought that the bromineatoms in this compound would be readily replaced by the amino-group, but all attempts to do this by means of aqueous, alcoholic,or liquid ammonia only resulted in the hydrolysis of the compoundand formation of a halogenated acid amide.When glycerol and anamino-acid are heated together, the glycerol appears to act as adehydrating agent, with the result that the anhydride93 of theamino-acid is formed; in fact, this is a convenient method forpreparing these substances; thus an 80 per cent.yield of diketo-piperazine is obtained when glycine and four to five times its weightof glycerol are heated together a t 170° for some hours, By thesame method sarcosine and alanine are transformed into theircyclic anhydrides, and leucine into leucinimide.A new and simple method for the separation 94 of betaine hydro-chloride from molasses residue has been worked out by Stoltzen-berg. It is based on the fact that whereas the solubility of thealkali chlorides and 'of glutamic acid hydrochloride is very muchless in concentrated hydrochloric acid than in pure water, that ofbetaine hydrochloride is slightly greater in the former than in thelatter solvent. The molasses residues are saturated witch hydrogenchloride, and the precipitated alkali chlorides and glutamic acidhydrochloride, etc., filtered ; the filtrate is concentrated, and alcoholadded to the residue, when the betaine hydrochloride, which issparingly soluble in alcohol, is precipitated.The method is applic-able t o the separation of betaine from other mixtures.The aminotyrosine obtained by redhction of the nitro-compoundresulting from the nitration of tyrosine is not 3-aminotyrosine,E. Abdarhalclen and RI. Giiggeiiheim, Zcitsch. physiol. Chem., 1910, 65, 53 ;A., 1910, i, 226 ; R. Alpern and C. Weizniann, T., 1911, 99, 84.9d L.C. Maillard, Compt. rend., 1911, 153, 1078; A., i, 13.9 j Ber., 1912, 45, 2248 ; A . , i, 680104 ANNUAL REPORTS ON THE PROQRESS OF CHEMISTRY.but a mixture of this compound and its isomeride, 2-aminotyro-sine.95Amino-acids readily react with various sugars (dextrose,galactose, maltose, lactose, arabinose, etc.), with evolution of carbondioxide and formation of cyclic condensation products, whichappear to be identical with the melanin pigments obtained in thehydrolysis of proteins. I f this identity is confirmed,it will providean explanation for the comparatively low yield of amino-acidsobtained in those cases where amino-acids and sugars are amongstthe products of hydrolysis.96A synthesis of racemic arginine from ornithuric acid (dibenzoyl-ornithine) as a starting point has been effected by Sorensen,Hoyrup, and Andersen.97 I f ornithuric acid is hydrolysed withwarm concentrated hydrochloric acid 6-monobenzoylornithine isobtained, but by using N/5-barium hydroxide the 6-benzoyl groupis removed, and the product is a-monobenzoylornithine,NH,*CH,*C€€,*CH,*CH(NH*COPh)*CO,H.This on treatment with cyanamide and subsequent elimination ofthe benzoyl group givesNH,*C (:NH)*NH* CH,= CH,*CH,*CR( NH,) *C'O,H,which is found to be identical in every respect with racemicarginine.The isomeric 6-amino-ctguanidino-n-valeric acid was alsoprepared, and found to have quite different properties.An important step in the determination of the constitution ofthe protamine clupeine98 has been worked out.When this sub-stance is nitrated a nitro-compound is obtained, which on hydro-lysis yields nitroarginine ; this nitroarginhe on treatment withnitrous acid by van Slyke's process evolves nitrogen in amountcorresponding with the decomposition of one amino-group. Sinceneither guanidine, nitroguanidine, nor clupeine itself givesnitrogen with this reagent, it follows that the amino-group in nitro-arginine which is decomposed by the nitrous acid is not free inclupeine, but forms part of the main chain. Further, clupeine andguanidine behave similarly when nitrated, and have the same acid-fixing power. It follows, therefore, that the arginine groups inclupeine are linked up thus:***CO*NH*TH--CO-N H-TH*CO*NH***y 3 H 6 y8Hf3NH*C(NH)*NH, NH*C(NH)*NH,95 C.Funk, T., 1912, 101, 1004.96 L. C. Maillard, Compt. rend., 1912, 154, 66 ; A., i, 169.97 Zeilsch. yhysiol. Chem., 1911, 76, 44 ; A., i, 13.98 A. Kossel and A. T. Cameron, ibid,, 1912, 76, 457 ; A., i, 326ORGANIC CHEMISTRY. 105Mercuric acetate (25 per cent. solution) in the presence of sodiumcarbonate is an efficient reagent for the precipitation of amino-acids.99 The precipitate appears to be a ba& salt of a carbamicacid formed from the aminc-acid by the action of the sodiumcarbonate. The amino-acid is readily regenerated by the action ofhydrogen sulphide on the mercury salt:NH,*CH,*CO,H 5'3 COzNa*NH*CH2*C02Ka 3~ H - " ~ ~ > H ~ . H ~ oC H,*C02N€T,*CH,*CO,H + CO,.The methods available for the estimation of the amino-acidsresulting from the hydrolysis of proteins give an approximate resultonly; in fact, in the majority of cases only about 60 per cent.ofthe protein is accounted for from the amount of amineacidsobtained. With the view of devising a more accurate method,Nov6k 1 has studied the action of methyl sulphate on several amino-acids, and finds that methylation occurs a t both the nitrogen atomand a t the carboxyl group, the action being similar to that ofmethyl iodide. With methyl sulphate, however, the action is almostquantitative, and much more easily carried out. An abnormalresult was obtained with Z-aspartic acid, which was converted almostquantitatively into fumaric acid.That proline is a primary product of protein hydrolysis has nowbeen definitely proved by its direct isolation as hydantoin from theproducts of fermentative hydrolysis of casein or gelatin.lapMiscellaneous.NNCarbon pernitride, N~C*N<I I or NiC*N:NiN, has been obtained 2by the action of cyanogen bromide on a well-cooled aqueous solutionof sodium azoimide'; it forms colourless, odourless needles meltinga t 35'5--36O, and soluble in water and the ordinary organicsolvents.It sublimes when heated in a vacuum just above itsmelting point, commences to decompose a t 70°, and explodes veryviolently a t 170-180°; since it is very sensitive to shock, it shouldbe prepared in small quantities only. I n aqueous solution it soonhydrolyses, giving azoimide and carbon dioxide as final producta :99 C.Neuberg and J. Kerb, Biochem. Zeitsch., 1912, 40, 498 ; A., i, 540.* Ber., 1912, 45, 834; A., i, 337.In E. Abderhalden and K. Kautzsch, Zeitsch. pkysiol. Chem., 1912, 78, 96 j A . ,I, 492. G. Darzens, Compt. rend., 1912, 164, 1232; A . , i, 542106 ANNUAL REPOKTS ON THE PROGRESS OF CHEMISTRY.M7hen pure i t is quite stable, but in the presence of traces ofbromine it is converted into a polymeride insoluble in ether.Pure diazomethane3 has been obtained by the addition 6f analcoholic solution of chlo-roforxn t o a hot alcoholic solution ofpotassium hydroxide and hydrazine, a slow stream of nitrogen beingpassed through the apparatus, whereby the diazomethane is removedand then absorbed by ether :H,N*NI-T, + CHCI, + 3KOlC -+ >C:N*NH, + 3KC1+ 38,O>C:N*NH, -3 H,C:NiN.Pure diazomethane boils at - 2 4 O to - 2 3 O , and is an extremelydangerous substance, exploding spontaneously or by contact withiodine, etc.When carbon monoxide is passed through a 1 per cent.ethereal solution of diazomethane and the gaseous mixture heateda t 400--500°, the methylene resulting from the decomposition ofthe diazomethane combines with the carbon monoxide to formketen.A solution of tetranitromethane in petroleum or other paraffinhydrocarbon gives intense colorations with compounds containingethylenic linkings, and can be used as a delicate reagent for thedetection of this class of substance^.^ The coloration is producedby unsaturated hydrocarbons, alcohols, ketones, ethers, esters, andaromatic substances, but not by aromatic nitro-compounds or bymany unsaturated carboxylic acids.The enolic form of a taut+meric compound also produces a coloration with the reagent,whereas the ketonic form does not.Ozonised oxygen produced by the silent electric dischargecontains a t least two allotropic modifications of oxygen, that is,ordinary ozone, 0,, and oxozone, 04, the latter forming about one-third of the “crude” ozone.5 When “crude” ozone is passedthrough sodium hydroxide and concentrated sulphuric acid, theoxozone is destroyed and the residual gas forms normal ozonides.The presence of oxozone in ozonised oxygen accounts for the forma-tion of ozonides containing more oxygen than that correspondingwith their degree of unsaturation, and also for the discordantresults obtained by different workers when investigating the actionof ozone on unsaturated compounds ; thus Ap-butylene when treatedwith ozone, freed €rom oxozone by treatment with sodium hydr-oxide and sulphuric acid, gives the normal butylene ozonide,and bisbutyIeiic ozonide, (C4H80J2; the former is O-YHMeO<O- CHMe’H.Staudinger and 0. liupfer, Bey., 1912, 45, 501 ; A . , i, 245.I. Ostromisslensky, J. pr. C?tm., 3911, [ii], 84, 489 ; A., i, 1.C Harries, Ber., 1912, 45, 936 ; A., i, 407 ; Annalm, 1912, 390, 235 ; A , ,i, 673ORGANIC CH EM ISTHY. 107an oil with a stupefying odour, and the latter an odourless liquid,which explodes a t 1 2 5 O . With ‘‘ crude ” Ozone Afi-butylene gives,not only the normal ozonide, but also butylene oxozonide, C4H80,,and bisbutylene oxozonide, (C,H@,)2.By further treatment with“ crude ” ozone the normal butylene ozonide remains unchanged,whereas the bimolecular form is converted into bisbutylene oxozon-ide. When treated with boiling water all four substances aredecomposed, and yield acetaldehyde, acetic acid, hydrogen peroxide,and oxygen.As an example of the discordant results which have often beenobtained in the past by different workers when studying the actionof ozone on one and the same compound, we may take the caseof the well-defined substance cholesterol. I n 1908 Dor6e andGardiierG obtained an ozonide from it, to which they gave theformula c 2 7 1 3 4 6 0 4 ; in the same year Diels stated that the ozonidecontained more oxygen, and that its formula was C2,H4,O,; lastly,Molinari and Fenaroli8 stated, also in 1908, that the ozonide whichthey had obtained had the composition C2,H4607, and that conse-quently there were two double linkings in the cholesterol molecule.Harries 8a has recently investigated the action of ozone free fromoxozone on cholesterol, and has shown that the ozonide has thecomposition C2.;H,,(OH)03, thus confirming Tschiigaeff’s 9 statementthat the cholesterol molecule contains only one double linking.Bamberger and Suzuki lo have obtained nitroglyoxime in theform of white, silky needles by the action of concentrated nitricacid on glyoxime dissolved in a mixture of ether and water.Sincei t appears necessary that the nitric acid should contain traces ofnitrous acid it is probable that a nitroso-compound is first formed,which is subsequently oxidised by the nitric acid, the reduction ofthe latter affording a fresh supply of nitrous acid:H*$XN*OII HS02 ON y:N*Ot€ RS03 O,N*$XN*OHH*C:N*OH -+ H*C:N-OH ---* I-T*C:N*OH’That the substance is really a nitro-compound and not thenitrite (I) is very highly probable, since i t does not give a typicalLiebermaim reaction, and can also be obtained by the action ofnitrous acid on methazonic acid (11):ON*O*$XN*OH O,N*VH,H*C: N *OH H-C: N~OH(1.1 (11.)Nitroglyoxime has certain properties characteristic of nitrolicacids, in that it dissolves in alkalis to a deep red solution, and givesBcr., 1908,41, 2596 ; A , , 1908, i, 728.T., 1908, 93, 1328.Ibid., 2785 ; A., 1908, i, 882. 8IC L O C . cit.lo Bcr., 1912, 45, 2740; A , , i, 839. 9 Annalen, 1911, 385, 352; A , , i, 30108 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRP.deeply coloured salts. The substance @2H&N3, which Ulpianiobtained by the action of nitric acid on glyoxime, and which heregarded as a furoxan derivative of the constitution :0is now proved to be a mixture of nitroglyoxime and glyoxime.The various methods available for the determination of theproportion of ketonic and enolic isomerides in a deemotropic com-pound were briefly described in last year's report.11 One of these,the bromine @-naphthol process, has been applied recently byMeyer 12 to a large number of such compounds, with the followingresults : Keto-enolic tautomerism does not occur in crystalline sub-stances, the crystals consisting of one form only.The modificationin which a desmotropic substance exists in the crystalline state isnot necessarily the one which will predominate in solution; thusdibenzoylacetylmethsne is ketonic in the solid state, but in solutionin alcohol or benzene over 90 per cent. of it is enolic; also methyloxalacetate is enolic in the solid state, whereas the keto-form largelypredominates in alcoholic solution. Acetaldehyde, acetone, pyruvicacid, and acetophenone, which contain one *COR group, are presentin alcoholic solution almost entirely in the keto-form, even in thepresence of sodium ethoxide. A comparison of substances contain-ing a methylene group attached to two *COR groups (R=H, Me,Ph, OH, OMe, OEt, NH,, CO,Me, or C0,Et) shows that insimilarly constituted compounds the influence favouring enolisationexerted by various radicles increases in the order OMe, OEt, OH,NHPh, Me, Ph, CO,Et, C0,Me.Ethyl malonate consists entirelyof the keto-form. Its sodium salt in methyl alcohol solution has theconstitution CO,Et*CJH:@(ONa)*OEt, and when it is acidified theresulting enolic modification of the ester very quickly changes t othe ketonic form.Tetramethylammonium amalgam 13 is obtained by the electrolysisof a solution of tetramethylammonium chloride in absolute alcoholkept a t -34O, a mercury cathode being used. The resulting semi-solid product a t the cathode is washed free from alcohol by carbontetrachloride, and the liquid mercury removed by suction, whenthe amalgam is left as a silver-white, crystalline, metallic mass,which if kept a t 0" under carbon tetrachloride undergoes very11 Ann.Report, 1911, 100.l3 H. I?. McCoy and W. C. Moore, J. Amer. Chcm. SOC., 1911, 33, 273; A.,1911, i, 270 ; H. N. McCoy and F. L. West, J. Physical Chc?n., 1912,16, 261 ; A , ,i, 539.Rer., 1912, 45, 2843, 2864 ; A . , i, 940, 941ORGANIC CHEMISTRY. 1013little change in the course of several hours. During its spontane-ous decornposition the amalgam emits negative electricity, and theresidual mercury, if insulated, acquires a positive charge.ClmZesteroZ.-From the acid,l4 C,&4404, obtained by the oxida-tion of cholesterol, Windaus 15 has obtained the following degrad*tion products :(:,Hl,*C,7H2,*CH : CH, distillatioll "'it11 C,H,, *Cl7.t€,,* C H CH, +--(CH$O),C, / \ (C27H4404)CO,H CH,*C02H/ \CO--CH2I+02(C26H420)C,Rl ,*C17T3,,*C0,H/ \CO,H C0,HJheatedLactone, C24H3603 o2 C,H,,*C17H2,*C0,Hor f- \/ coI c,4H3803+O'CO,H*CH,~C,,H,,(CO,H), 2:~- / \(CH,),CO and 'sH1l *CMH!24*C02H(C21H3008) CO,H C0,HCH,-CO,H, etc.I $distilledC,H,l~C,,H24~C0,H+02\/ coThe ketone C2,H4,0 is the next lower cyclic homologue ofcholesterol, and since it is obtained by the distillation of the freeacid, cuH4404, it follows that the two carboxyl groups in this acidare in a 1:6- or l:7-position t o each other; consequently, incholesterol itself the ring containing the *CH*OH-group mustcontain 6 or 7 carbon atoms.The conversion of the acid, C2,H4,06,into the ketonic acid, C,H,03, is analogous to the conversion ofhomocamphoronic acid into camphononic acid 16; hence, in the acidC2,H4,06 the two carboxyl groups which disappear are also in the1 : 6- or 1 : 7-position. Further, the formation of the tribasic acid,C24H3806, from the ketonic acid, C24H3803, shows that this sub-stance has a *GH,-group next to the carbonyl group (compare con-version of camphononic acid into camphoronic acid lea), and so themode of attachment of another carbon atom in the cholesterolmolecule is ascertained. The formation of acetic acid by oxidationl4 Diels and E. Abderhalden, Bm., 1904, 37, 3092 ; A . , 1904, i, 880,la Ber., 1912, 45, 1316, 2421 ; A., i, 449, 854.Iti Lapworth and Chapman, T., 1899, 75, 986, 1003.16(c Ibid110 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.of the tetrabasic acid, GlH3008, shows that this acid contains amethyl group, and its formula, may be written:A similar conclusion as to the presence of a methyl group in theC1,Hz6 nucleus is arrived a t by Minovici and Vlahutza,l7 who haveobtained the acid C2,H,,0, by the action of hydrogen peroxide onchlolesterol.The following formula for cholesterol is now proposed byWindaus :CHMe,*CH2-CH,*CllH17C‘H CH/\The two resins, “jalapin,” from the root of Zpomoea urkz&cnsis,and “ scammonin,” from scammony root, have been hithertoregarded as identical substances, and as consisting of a homogene-ous substance of glucosidic character.Both resins have now 18 beensubmitted to a very thorough chemical examination, and shown tobe very complex substances, and to differ very considerably in theirComposition. They appear to consist to a large extent of the gluco-sides and methylpentosides of jalapinolic acid (hydroxyhexadecylicacid), CI,HN(OH)*CO2H.Hankow Chinese wood oil19 on exposure t o light in glass bottlesfitted with air-tight stoppers gradually deposits crystals, which a tthe end of a year amount to about 6 per cent. of the oil. Thesecrystals consist of the glyceride of 8-elaeostearic acid, and on hydro-lysis yield the free 8-elzeostearic acid, C18H3202 or C,,H,O,, meltinga t 7 2 O , of which several derivatives have been prepared.Both thefree acid and its derivatives readily absorb oxygen on exposure toair, but although the ethyl ester soon gains 12 per cent. in weight,yet it does not set like the Chinese wood oil. The study of thiscrystalline glyceride may help to throw light on the changes whichoccur when a drying oil is exposed to air.Fossek has shown that when the product of the interaction ofphosphorus trichloride and an aldehyde, R*CHO, is treated withwater, a31 acid of the type R*C?H(OH)*PO,H, is obtained. ThisBulZ. SOC. chim., 1912, [iv], 11, 747 ; A., i, 697.’8 F. B. Power and H. Rogerson, T., 1912, 101, 1, 398.l9 R. S. Morrell, ibid., 2082ORGANIC CHEMISTRY. 111work has been confirmed and extended by Page,zo who has suc-ceeded in preparing hydroxymethylphosphinic acid,OH*CH2-P0,H2,by using paraformaldehyde or trioxymethylene instead of theformaldehyde itself.Kipping 21 has revised the nomenclature of the organic deriv-atives of silicon, and suggested systematic names for the complexcondensation products resulting from the silicanediols.The same author22 has succeeded in preparing pure diphenyl-silicanediol, SiPh,(OH),, by the hydrolysis of dichlorodiphenyl-silicane. The isolation of the diol in a pure state presented excep-tional difficulties, as the impurities were apparently adsorbed bythe crystals. Pure diphenylsilicanediol usually decomposes andliquefies below 132O, but occasionally tho decomposition does notoccur below 160O.This apparently " double" melting point is notregarded as due to the existence of an isomeride, but is explainedas follows : the crystalline form of diphenylsilicanediol, which sepa-rates from solvents a t about 10-60°, decomposes and liquefiescomplehly a t about 128-132O, but near its melting point it is ina metastable state, and may, especially if certain impurities arepresent, change into another crystalline form, more stable a t thishigher temperature, which only decomposes a t 160° ; usually, how-ever, the pure compound decomposes and liquefies before thischange occurs.Perhaps the most cl .racteristic property ofdiphenylsilicanediol is the ease with which i t loses the element.3 ofwater, the presence of traces of alkalis or acids being sufficient toeffect this loss, four well crystallised compounds having beenisolated from the products of this change, namely:(1) anhydrobisdiphenylsilicanediol, HO*SiPh,*O*SiPh,*OH ;(2) dianhydrotrisdiphenylsilicanediol,(3) trianhydrotrisdiphenylsilicanediol,HO*SiPh2*O*SiPh2*O*SiPh2*OH ;(4) tetracanhydrotetrakisdiphenylsilicanediol,iPh,*O*SiPhO<iiPh 0.S iPh;>"The study of the formation of analogous anhydrides from mixeddiols like phenylbenzylsilicanediol, and also of mixed anhydridesfrom mixtures of, say, diphenylsilicanediol and dibenzylsilicanediol,will no doubt afford valuable information as to the structure ofthe complex inorganic silicates.r, T., 1912, 101, 423.21 Ibid., 2106. 'La Ibid., 2108, 2125112 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n a previous communication, Robison and Kipping 23 describedthe decomposition of dic hlorodibenzyl$ilicane, Eli (CH,- C6H,),C12,and stated that the products were the isomerides a-dibenzylsilicoland P-dibenzylsilicol; the same authors 24 now show that the a-com-pound is dibenzylsilicanediol, Si(CH,*C,H,),(OH),, and the/3-compound is an anhydro-derivative or oxide of dibenzylsilicane-diol, crystallised with one molecule of water, and having the com-position HO Si (CH,*C,H,),*O*Si ( CH2*C6H5),*OH,H,0, and nownamed anhydrobisdibenzylsilicanediol.H. R.I,E SUEUR.PART II.-HOMOCYCLIC DIVISION.Although a t the present. time the difficulty of tracing the genesisof an idea in Chemistry in the vast literature is an excuse for thefrequent claims to priority, which every journal contains, it seemsindeed remarkable that fifty years ago a monograph,l in which notonly was valency used in the modern manner, but also Kekule‘forestalled by more than four years in the famous benzene formula,could entirely escape notice.Loschmidt’s monograph, which hasbeen rescued from forgetfulness by Anschutz,2 will be deservedlyplaced among the ‘(cla~sics” of science. He recognises the“ polarity ” (localisation or direction) of valence, and states withrare lucidity the ideas which should be a t the basis of the ordinarystructural formuh; the analogy between benzene and marsh gasas the first members of series, and the relation between the homo-logues and derivatives of the former were perceived a t a time whenno complete hand- or text-book of organic chemistry had beenwritten, and the literature, especially of aromatic chemistry, waschaotic.That Kekul6 was aware of Loschmidt’s work is provedby his own words 3; but i t seems highly probable that he had onlyheard of the monograph from Kopp, who had come across it aseditor of Liebig’s Jahresb ericht.4 Although Loschmidt saw thepossibilities of isomerism depending on the attachment of thesubstituent to a side-chain or the nucleus, he did not go so far asKekul6 in the recognition of the isomerism of the nuclear di- andtri-derivatives of benzene.Structure of the Benzene Nucleus.-The fifty-two years which2B T., 1908, 93, 441. z k Ibid., 1912, 101, 2142, 2156.J. Loschmidt, Chemische Studien, 54 pp., Wien, 1861.R.Anschutz, Ber., 1912, 45, 539 ; A., i, 247.Bull. SOC. chim., 1865, [ii], 3, 100.1861, 335ORGANIC CHEMISTRY. 113have elapsed since Loschmidt recognised the molecule of benzene asformed of a remarkably stable ring of six carbon atoms, have addedvery. little to our knowledge as to the exact structure of thebenzene nucleus. Willstatter and Waser’s 5 recent discovery ofcyclooctatetraene has once more revived interest in the question :CH*CH/ / \YHCH =(? HCThis tetraene (like cyclobutadiene) is just such a closed systemof an even number of alternating double and eingle linkings as isbenzene. Yet in chemical properties it offers the most strikingcontrast, and behaves simply as a cyclic olefine; it reduces perman-ganate vigorously, and adds on bromine instantly; it takes up fourmolecules of hydrogen in the presence of platinum, and with nitricacid gives no substitution products, but becomes a tar. Moreover,on heating it is converted into stable, more saturated isomerides,probably by forming bridge linkings (see p.145).I n the light of this great difference in character, Willstiitterurges that there must be some fundamental difference in molecularstructure. Thiele’s theory of partial valence shows that the residualaffinity of any closed system of alternating double and single link-ings would be very much the same; and hence the chemical char-acter of two such rings would not vary greatly with the number ofatoms of which the ring is composed. Willstatter claims, therefore,that the discovery of cyclooctatetraene gives a final demonstrationthat KekulB’s formula is to be replaced by some other, and decidesin favour of Armstrong’s centric formula.6 It is suggested thatthe tetraene cannot change into a similar centric configuration onaccount of the distance of the carbon atoms from the centre offigure.The comparison of benzene, cyclooctatetraene, and naphthalene,more especially in their tendency to combine with hydrogen, leadsWillstatter to the conclusion that Harries’ formula for naphthalene(in which one ring onTy has a centric structure), based on itsbehaviour with ozone, is to be preferred.’Another interesting observation on the character of compoundswith a, para-bridge-linking has been interpreted as indicating thecentric structure of benzene.Although it is by no means unusualto find formulae in which a bridge-linking is used, the undoubtedBey., 1911, 44, 3423 ; A . , i, 17. T., 1887, 51, 264.7 Annalan, 1905, 343, 311 ; d., 1906, i, 225.HE P.-VOL. 1X. 114 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.synthesis of one in spite of many attempts has only just beenachieved by J. von Braun,* who has converted p-aminopropyl-benzene into pindole,the complete similarity between the p- and o-indoles is held to beexpressed only by a centric or diagonal structure of the nucleus.The conceptions as to the exact relations of the carbon atomsin the benzene ring are naturally dependent on the precise viewsof valency on which they are based. Accepting the constantquadrivalency of carbon, and fixity of the directions in which thevalency is exerted, the Kekul6 formula, represents benzene ashaving a much smaller ring tension, 2O35’, than a ring of sixsingly-linked carbon atoms, of which the ring tension is 5O16/, suchas the hexamethylene ring, and the ring in the centric formula.Thedifference in reactivity between the Kekul6 ring and the octa-tetraene ring may well be referred to this fact.9 With the newerand less rigid conception of valency, the relation of the membersof the ring may obviously be far more varied and elastic than isexpressed by the usual alternative formulation. Moreover, adynamic rather than a static structure has in addition been reliedon to account for many of the properties (mainly optical) of thearomatic series ; thus largely on the ground of the peculiar opticalproperties (fluorescence, etc.) of aromatic compounds, von Liebig 10911urges that a t the double linkings in benzene, a continuous rockingmotion is to be found (a suggestion which differs little from manyearlier ones), whereas in the tetraene, which is of yellow colour,there are two pairs of double linkings each analogous to the pairin a henzoquinone; the oscillations at the four double linkings donot fall into the rhythm characteristic of benzene, and hence thedifference in chemical character.In Thiele’s and Armstrong s benzene formulze, the originalvalency theory is extended, if not abandoned; in the former eachcarbon atom is quinquevalent, and in the latter each has a generalattachment to the five other carbon atoms.On the basis of Werner’stheory of a universal a f i i t y acting in all directions from atomiccentres, a new way of representing the peculiar properties of thebenzene ring is described in an interesting paper by Boeseken.12 I ne. Ber., 1912, 45, 1274; A., i, 497.9 J. Boeseken, Proc. I?. Akad. Wctensck. Amsterdam, 1912, 14, 1066; A., i,lo J. pr. Chem., 1912, [ii], 86, 175 ; A . , i, 686.430.R. Casares, Anal. Fis. Quim., 1912, 10, 14 ; A., i, 247. LOC. citORGANIC CHEMISTRY. 115order to account for the union of two like atoms to form amolecule, a certain difi’crence analogous to that between opticalisomerides, which is not a difference in energy, must exist.Thisdifference is represented by opposite rotatioils of the atoms, a deviseby which a “dynamic” condition can also be simply expressed.13When applied to the benzene ring, this idea is symbolised as in theannexed figure. It will be seen that the contrast between the ortho-and para- on the one hand, and the meta-moreover, the equality of tihe two orthGpositions. When a carbon atom is /‘groups, they occupy the angles of a tetra-hedron. I f , however, three atoms orposition on the other, is shown, and, 0 0 attached to the maximum four atoms or “0 Q”groups are attached to a carbon atom, 0 t-Josince, following Werner, a fixed valency “ 0 direction does not exist, the three atomslie in one plane grouped round thecarbon. Hence it is conceived that the six carbon and sixhydrogen atoms of benzene lie in one plane, when in a configura-tion of most stable equilibrium, and that the unsaturation orresidual affinity is evenly distributed over the whole molecule. Lessclearly defined, but somewhat similar, views are expressed by H.Kauffmann 14 in the statement of his auxochrome theory (seeThe best test of this formulation is its ability to bring intoharmony the various facts of substitution, and the other reactionsof benzene; thus a particular advantage of the centric formula,and t o a certain degree of Thiele’s modification of KekulB’s, is thatthey represent the great change of properties on adding a moleculeof hydrogen to such a derivative as terephthalic acid.I n the unsub-stitutecl benzene the even distribution of affinity will tend toprevent the local addition of chlorine or bromine, which mayprecede substitution; and, in the absence of a catalyst, i t has beenfound that even when the benzene is in excess the additive benzeneliexahaloid is alone produced.15 The addition of hydrogen tonaphthalene and other condensed rings may be an example of localaddition, but here there is a possibility of a less even distributionof residual affinity.Whether, however, substitution in benzene byhalogens in the absence of a catalyst is preceded by local additionmust a t present be left an open question; the primary additivewill, to obtain the simplest arrangement, c,p. 137).Rec. trnv cJ~iwt., 1910, 29, 86.BcT., 1906, 39, 1959 ; A., 1906, i, 811 ; ‘ I Die Valenilc*hre,” 1911.l5 T.van der Linden, Bw., 1912, 45, 231 ; A . , i, 174.1 116 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.products have not been isolated at least in this case.lG The existence of a very large number of additive compounds of the usualcatalysts with hydrocarbons, which have been recently studied,17suggests that the catalyst acts by modifying rather the benzenethan the halogen. The disturbance of the even distribution of theaffinity by the catalyst will render easy the local addition ofhalogen. The subsequent elimination of hydrogen bromide wouldobviously be accompanied by a considerable fall of chemicalpotential, but the catalyst may also accelerate this part of theprocess of substitution. In the case of nitration and sulphonationthe evidence is clear that the agents themselves provide thecatalyst, which is most probably the anhydride of the acid.In a monosubstituted benzene the residual affinity can nolonger bs evenly distributed, a fact which may be expressed inBoeseken’s diagram or by modifications of KekulB’s formula inthe manner suggested by Flurscheim 18 by the help of partial orsubsidiary valence.The presence of a group, X, attached to carbona t one end of the conjugated double linkings, 1,6 and 5,4, willaffect the power of addition a t pwitions 1 and 4 and a t the posi-tions 1 and 6, but not, or not to such an extent, a t the positions2 and 319:XR\I! ill \>’The mere presence of the group for this reason favours ortho-para-rather than metmmbstitution.Substitution will occur in the threepositions, but with very different velocities, which will vary withthe nature of X, and hence produce different proportions of thethree di-derivatives in the final products. The results of the nitra-tion of many monosubstituted benzenes give excellent illustrationsof this proposition.A second factor has to be taken into account, namely, the attrac-tion exerted by X on the substituting agent. When this is suffi-ciently great the group X will be chemically changed, as in the16 A. F. Hollenian and J. Roescken, Proc. h7. Aknd. WetensciL. A?izsterdam,1910, 18, 535; A. Werner, “Neuere Anschauuiigen,” 2nd. Ed. ; E. Fischer,Annaten, 1911, 381, 123 ; A., 1911, i, 418 ; W.Manchot, Annulen, 1912, 387,257 ; A , , i, 230.l7 Among others, B. N. Menschntkin, J. Xius. Phys. CJLem. Soc., 1911, 43,1275, 1785, 1303, 1329, 1805 ; A . , i, 98, 99, 100, 177, 193; P. Pfeiffer, Annulciz,1911, 383, 92 ; A . , i, 783.18 T., 1909, 95, 718 ; ibid., 1910, 97, 84.19 A. F. Holleman, “Die direkte Einfuhrung von Substituenten in denBenzolkern,” 1910 ; Holleman and Biieseken, Zoc. cit. ; J. Obermiller, “ Dieorientierenden Einfliisse und der Benzolkcrn, ” 1909ORGANIC CHEMISTRY. 117reduction of the nitro-group, oxidation of the thiol group, etc., orwill form only unstable additive products, which have occasionallybeen isolated, especially in the case of amines.20 The attractionbetween X and the agent may, however, under the given conditionsfall short of reaction or addition, and only result in a very rapidortho-paraaubstitution, for example, when X is hydroxyl in phenols ;or the attraction may be still slighter and meta-substitution accom-pany the ortho-para, as in toluene, the process now having a smallervelocity.Finally, the nature of X (for example, a nitro-group)may be such as t o inhibit substitution, whence it follows theposition, 2,3, which is least under its influence, will be attacked,and meta-substitution, which is always a relatively slow reaction,predominate. It is obvious that in the addition t o the 2,3 linking,a t least some ortho-derivative should be formed; and exact workhas demonstrated that, a t least so far, pure meta-substitution hasnot been observed.21 Although the group X may inhibit theaction of the ordinary substituting reagents, it may yet render thebenzene derivative more accessible to others ; then, however, anortho-para-reaction will follow.As examples will serve the replacement of chlorine by hydroxyl when orthepara to a nitro-group,and the ready reduction of benzoic acid and still more phthalic acid(to A3:6-dihydrophthalic acid) in the ortho-para-positions by hydro-gen, (These are also examples of the primary local addition.) Thereaction (or union) of the substituting agent with the group X,and the fact that the products can often be converted into nuclearderivatives (sometimes isomeric, as, for instance, nitroamino-benzenes and nitroanilines, benzoyl nitrate, and m-nitrobenzoicacid) has resulted in the popular opinion, which so often findsexpression in the literature, that these substances are necessaryintermediaries, and that the conversion, when it occurs, is intra-molecular.An intramolecular change may occur in this as inother reactions, but the evidence that such is the case must beforthcoming.22The foregoing gives a very brief summary of the views a t presentheld by those who are now engaged in studying the problem ofsubstitution in aromatic compounds. It cannot be said that therecent exposition of the mechanism of substitution in benzenecontains much that was not embodied in earlier conceptionse3; the2o H. Wieland, Be?.., 1907, 40, 4260; A., 1907, i, 1076; ibid., 1910, 43, 699 ;A., 1910, i, 242.21 A.F. Holleman and collaborators, Zoc. cit. ; and Bey., 1911, 4.4, 704; Rev.trav.-chinz., 1911, 30, 48 ; BzdZ. Xuc. chirn., 1911, [iv], 9, i.; Ber., 1911, 44, 2504,3556 ; A . , 1911, i, 364, 535, 713, 849 ; 1912, i, 20.T2 Brit. Assoc. Reports, 1910, 85 ; Xcience Progress, 1909, 4, 213.Armstrong, ibid., 1899118 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.newer views on valency have given freedom, and exact quantitativework has brought precision, but the fundamental ideas are littlemodified.Nitro-co ntpounds.The study of the absorption spectra24 of a very large iiuniber ofnitro-compounds, and of their metallic and alkyl derivatives, hasbrought to light some very striking facts with regard to the isomer-ism of this group. Up to the present there was no doubt that twodesmotropic forms existed, the true nitro-group, *NO,, and theiso- or aci-nitro-group, present always in the salts, to which variousconstitutions have been assigned.The Michael-Nef formula,RR'C:NO*OH, is more generally accepted, although the formulaRR'C*N*OH, originally put forward by Hantzsch, finds someadherentszs; but the reactions, which have been urged as evidencef o r the latter, are those exhibited by compounds in which othernegative groups (carbonyl, phenyl, etc.) are present, and hencemay be due rather to the general character of the compound thanto the particular arrangement of the nitro-group.The spectroscopic investigations of Hantzsch 26 have convincedhim that a third type of nitro-compound exists, the " conjugatedmi-nitro "-compound.I n the spectra the three types are distin-guished in that the true nitro-compound has a feeble selectiveabsorption, the uci-nitro-compound feeble general absorption, andthe " Conjugated " mi-nitro-compounds very strong selective absorp-tion. The simple aci-nitrocompounds are only found in the other-wise unsubstituted nitrclparaffins. The conjugated is the invariableform of the salts whenever a negative (unsaturated) group(NO,, CO*, CO,H, Ar, CN, etc.) is combined with the carbonatom which bears the nitro-group; and i t is found uncombinedas well as in salts, esters, etc. So fundamentally different are thespectra of the " conjugated " mi-nitro-compounds from the othertwo classes, and at the same time so little affected by the characterof the compounds in which they are present, that Hantzsch urgesthe existence of some peculiar and characteristic constitution.Asix-membered ring, which is constructed with the aid of a sub-?4 Absorption spectra are now so universally described that reference cannot bemade here to all the papers, but attention may be directed t o a research dealingexclusively with the subject of this palagraph. G . T. Morgan and collaborators,T., 1911, 99, 1945 ; ibid., 1912, 101, '1209.\/025 W. Steinkopf and B. Jiirgcns, J. pr. Chem., 1911, [ii], 84, 686 ; A . ,i, 152.26 A. Hantzsch aud K. Voigt, Ber., 1912, 45, 85 ; A., i, 151ORGAXIC CHEMISTRY. 119sidiary valence, is this chromophore, and is represented in typicalexamples, thus :I n no case has a simple aci-nitro-form been observed when the" conjugated " aci-nitro-ring is capable of existence ; the equilibriumis directly between the true nitro- and the conjugated aci-nitro-forms, and not through the aci-nitro, thus:This fact, and t,he far-reaching optical and chemical analogybetween the negatively substituted ketones and the conjugatedacd-nit,ro-compounds, has led Hantzsch to modify his former opinionas to the relation between the ketones and the salts of theenolides, which are classed as similar conjugated " compounds,-C 0.C K ~ : ~ > M , in that an int.ermediary true enolide is now regardedas superfluous. The equilibrium is dependent on the nature of themedium, the dilution, and the temperature, and hence Beer's lawis not applicable to these solutions.27 Ionisation is, as usual, notrecognisable optically ; both the ion and the non-ionised compoundshow the same absorption.The chromoisomeric salts of nitro-compounds have the typicalspectra of the conjugated aci-nitro-form.Hence the earlier opinionthat i t was the isomerism of aci-nitro- and conjugated aci-nitro-compounds is abandoned, and since polymorphism is excluded, theauthor falls back on valency-isomerism, thus :*C:O-MMoreover, grounds are advanced for the existence of an equili-brium between the two forms in solution. It is, however, highlysignificant, that a compound which shows this chromoisomerism doesnot show the equilibrium with the isomeric true nitro-compound ;and, conversely, where this type of isomerism is observed, chromo-isomerism does not exist.It is here, perhaps, that the weak spotin this otherwise wonderfully clear-cut and convincing theory lies.The nitro2henols offer a very good example of the manifoldrelations of the nitro-group; i t is only, however, in the para-seriesthat the behaviour can be interpreted.28 p-Nitrophenol and the37 J. Piccard, Annnleit, 1911, 381, 347 ; A . , 1911, ii, 561 ; A. Hantzsch,Anmbn, 1911, 384, 135 ; A . , 1911, ii, 951.See also W. P. Ureaper, T., 1911, 99, 2094120 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.stable series of ethers have typical conjugated aci-nitro-spectra, andhence have the structure (I) of these compounds. The salts andthe red labile esters exert, however, a far stronger absorption, andhence they are given a quinonoid constitution, and a t the sametime a new position for the subsidiary valence (11):A neat demonstration 29 that salt formation in aromatic nitro-compounds only causes the special type of absorption just referredto, when a quinonoid rearrangement is possible, has been given ina comparison of the spectra of the following substances in neutralor alkaline media : pnitrobenzoic acid, phenylacetanitrile andphenylacetic acid, with those of p-nitrophenylacetonitrile, ethylp-nitrophenylacetate, and finally pnitrophenylacetic acid.I n thefirst group the spectra of the two solutions are practically identical,but in the second group a characteristic additional band appearsin the alkaline solution. I n the case of pnitrophenylacetic acidthis change is only observed in the presence of considerable excessof alkali, as a salt of the type NaNO,:C,H,:C'B:*CO,Na would beextensively hydrolysed.A constitutively unchangeable nitro-compound,30 which yetexhibits intense colour, has been found in 4'-nitro-2 : 5-dimethoxy-benzophenone.The authors find in it an excellent illustration ofKauffmann's theory (see p. 137) of the division of the valence-unit, brought about in this case by the interaction of the nitro-and methoxy-groups, as the cause of colour.Another interesting ob~ervation,~~ which may be related to thatlast mentioned, is the final demonstration tha.t there are twodistinct o-dinitrobenzidines, yielding distinct acetyl derivatives anddistinct dinitrodiphenyls.It is suggested that this is anothercase of the isomerism, referred to in other places in this report,which depends on the limitation of the free rotation of singly-linked carbon atoms.Some researches which cannot be dealt with a t length show thatmuch is yet to be learnt about the reduction of nitrobenzene byvarious methods.32~ 33"3 .J. T. Hewitt, P. G . Pope, and Miss W. I. WiIlett, T., 1912, 101, 1770.3O H. Kauffmann and A. de Pay, Ber., 1912, 45, 776 ; A., i, 365.31 J. C. Cain, A. Coulthard, and Miss F. M. G. Micklethwait, T., 1912, 101,33 R. C. Snowdon, J. Physical Chrn., 1911, 15, 797; A . , i, 100.33 E. F. Farnau, ibid., 1912, 16, 249 ; A., i, 436 ; H. C. Allen, ibid., 131 ; A , ,2298.i, 249ORGANIC CHEMISTRY. 121Diphenylarnine.The chemistry of the well-known blue reaction of diphenylaminewith nitric acid and other oxidising agents34 has been up to thepresent mainly a matter of speculation ; the most attractive hypo-thesis was that the salts of the halochro,mic diphenylhydroxyl-amine 35 produced the colour.Although the first product of the oxidation of diphenylamine ist8etraphenylhydrazine,36 which in an acid medium yields diphenyl-henzidine,37 yet H. Wieland came to the conclusion 38 that the tetra-liydrazine was hydrolysed to diphenylamine and diphenylhydroxyl-amine, which then condensed, and finally oxidised to theo-quinonoid sulphate of a phenazine :a compound the constitution of which now seems extremely doubt-ful.Eehrmann 39 has now demonstrated that the diphenylbenzidineis undoubtedly formed under the usual conditions of the reaction,and, moreover, yields with oxidising agents an intensely blue saltof a haloquinoneimonium type :which was isolated as the platinichloride.reaction is to be found in the formation of this compound.The cause of the colourXeto-enol Is0 rn erism.During the year the results of some extremely interesting andimportant researches on this subject have been published; theincreasing power and delicacy of the agencies a t the command ofchemist,s is particularly well illustrated in the advances which haverecently been made in this difficult subject.The methods which can now be used, not only for the recogni-tion of a compound as an enolide or ketone, but for the quantita-tive estimation of a mixture, are various.Of the chemical methodsthe ferric chloride colour reaction with the enolide (Wislicenus)is only applicable when the transformation takes place veryslowly, for this reagent disturbs the equilibrium by its powerfulcatalytic acceleration of the enolisation. Claisen’s method of34 Merz and Weith, Ber., 1872, 5, 283.35 A. von Baeyer, ibid., 1905, 38, 583.36 F. D. Chsttaway and H. Ingle, T., 1895, 67, 1090.37 V. Kadiera, Ber., 1905, 38, 3575; A . , 1905, i, 934.39 F. Kehrmann and St. Micewicz, Ber., 1912, 46, 2641 ; A., i, 1020.Annnlcn, 1911, 381, 200 ; A . , 1911, i, 569122 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.extracting the enollde by a dilute solution of sodium carbonate isconfined to solids, and is useless for solutions or liquid mixtures.The reaction with tertiary amines4O may give correct results inisolated cases, but is certainly not generally applicable.Themethod of bromination 41 in its improved form 42 is not only exceed-ingly trustworthy, but can be used for liquid, solid, and solutionwith equal ease. A high speed of enolisation would, however, asin all chemical methods, invalidate the conclusions as to thecomposition of the equilibrium mixture, and for this reason i thas not. been found applicable in the case of the phenylindan-di~nes.~sOf the physical methods, the molecular refraction (Bruhl) hasbeen shown recently by Auwers44 to be susceptible of exact quanti-tative application : where comparisons are possible and close agree-ment has been found between this and the bromine method.Theabsorption spectrum appears, however, to be the most delicatemethod when the equilibrium in solutions is t o be examined, andhas recently been used with great success by Hantzsch (Zoc. c i t . ) .By mea.ns of the method of bromination, K. H. Meyer has madean exact study of a large number of substances, and of the equili-brium between the keto- and enol forms in the molten state or insolution. It is now possible to state approximately the relationsbetween the constitution and the relative proportions of the twoforms in an equilibrium mixture.Such equilibrium mixtures are only found in the liquid or dis-solved, but never, as has been suggested, in the crystalline state;the solid consists of one form only.I f the solid (ketone or enolide)is the metastable, i t will gradually change completely into thestable form; so far a transition point where coexistence would bepossible has not been observed. Stability of one form in the solidstate bears no relation to the composition of the equilibriummixture, either in the molten state o r in solution; thus the stableketone, acetyldibenzoylmethane, (C,H,*CO),C’H*CO~CH,, in alcoholis enolised to the extent of 90 per cent. The nature of the solventshas, of course, a great influence; for example, methyl benzoyl-acetate is enolised to the extent of 0.8 per cent. in water, 13.4 inmethyl alcohol, 15.3 in chloroform, 69 in hexane, and 16.7 whenmolten.The value of the ratio (KijR’) of the equilibrium con-stants (equilibrium constant = K = [enolide]! [ketone]) of any twocompounds, a t least when &milady constituted, is nearly the same40 A. Michael an4 H. D. Smith, Aiznnlcn, 1908, 363, 20 ; A., 1908, i. 943.41 Ann. Report, 1911, 101.4: K. H. Meyer, Ber., 1912, 45, 2843; A., i, 040.J3 A. Hantzsch, AnnnleiL., 1912, 392, 286 ; A., i, 869.44 K. Auwers, Ber., 1911, 44, 3530; A., ii, 3ORGANIC CHEMISTRY. 123whatever the medium; thus the value of R for methyl benzoyl-acetate is about 2.2 times as great as the value of h- for ethylacetoacetate. Moreover, the same relation holds often, but not souniformly, for the molten state.Ziidandiones and 0xindones.-The keto-enol isomerism of theindandiones and bisindandiones (11) has been fully investigated byHantzsch and his pupils,45 mainly with the aid of the absorptioiisnectra :(1.1 (11.)The absorption spectra of the indandiones of the type I, whichare Learly colourless and not capable of enolisation, are continuous,and not markedly or sharply affected by the nature of the solventsor subcstituents.On the other hand, the indandiones containingthe group *CO*CHR*CO* yield salts exhibiting selective absorptionwhich are oxindone derivatives, *C(OH) :CR*CO*. These indan-diones, like ethyl acetoacetate, have in solution very variablespectra; in the active solvents (alcohol, etc.) enolisation is shownby the selective absorption, whilst in indifferent solvents the colourfades and the general absorption, typical of ketones, is observed.As will be seen, these relations are the converse of those found tohold with the ketonic esters, where enolisation is most prominentin indifferent media. A comparison of the spectra of the saltswith other enolic derivatives has led Hantzsch 46 to suggest that theformer have a peculiar structure, with the metal attached by asubsidiary valence to the carbonyl group as well as to the oxygen(111) :Po\ c:,GO ..... ...... 15\CR I C,iH4\- //CR 4b--# (J C-OAC(111.) (1V.)This type is called the '' conjugated " enolide. The new observa-tions on indandiones, etc., afford strong confirmatory evidence forthis suggestion. The acyl-oxindones, which are also enolic deriv-atives of the indandiones (IV), show spectra in which the selectiveabsorption is both less and simpIer than in the salts.In thebisindandiones and the hydroxytrisindandiones :the enolides and the enolic ethers have spectra resembling, and45 Annalen, 1912, 392, 286, 302, 319, 322, 328; A., i, 869.46 A ~ H . Report, 1910, p. 80124 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.often identical with, the salts, a fact which is interpreted asevidence for a “ conjugated ” structure in these compounds as wellas in the salts. The formula (111) shows that in the conjugatedstructure a six-membered ring exists; to this is attributed thepeculiar absorptive power as a consequence of a “strong isorropesicstate of vibration ” (“ lebhafte isorrhopische Schwingungs-zustand ”).The two types of salts, both enolides, which certainindandiones yield, are distinguished by the form of this “ conju-gated” ring. The indandiones, in which R in the group*CO*CHR*CO*is an alkyl radicle, produce red salts having high selective absorp-tion, whilst those in which R is an acyl radicle or contains acarbonyl group, yield yellow salts, the selective absorption of whichis feebler. This difference is attributed to the absence of the six-membered ring in the yellow salts, which have instead as a chromo-phoric group a fivemembered ring, thus:a,m,(c~>c*co x,‘O*Malso possessing a subsidiary valence.The peculiar existence of isomeric ketonic modifications of1 : 3-diketones has been studied by Michael 47 and his collaboratorsin the case of dibenzoylacetylmethane and dibenzoylpropionyl-methane.In both cases the more stable ketonic form (8) is con-verted into a second (y) by treatment with acetyl chloride. Thesetwo compounds are both unimolecular, and have widely differentmelting points. Since this isomerism cannot be accounted for bythe usual formulze, i t is suggested that it is due to a limitation ofthe free rotation of the singly-linked carbon atoms. Generally freerotation occurs until the configuration, in which the system hasthe ‘‘ maximum entropy ’’ is attained. When there is little differ-ence in the entropy between two or more of the possible configura-tions, then these forms may exist, and, moreover, be interconvert-ible by feeble chemical agencies if the difference in entropy is suffi-ciently small.The great difficulties of the investigation of the isomerism of the1 : 3-diketones are emphasised by the recent researches on ethylformylphenylacetate.48 Until recently, this compound was sup-posed to exist in four different forms, two of which were possiblystereoisomerides. Michael’s reinvestigation (Zoc.cit.) has led himto the conclusion that there are only three forms, one liquid and47 Annalen, 1912, 390, 30; A., i, 631.48 W. Wislicenns, ibid., 389, 265 ; A., i, 624 ; A. Michael, ibid., 391, 235, 275 ;A., i, 861; K. H. Meyer, Ber,, 1912, 45, 2843; A., i, 940ORGANIC CHEMJSTRY. 125two solid, all of which are, however, enolides. Wislicenus (Zoc. cit.),on the other hand, has reduced the number to two, the liquid ester(a), the hydroxymethylene (I), and the crystalline y-form (m.p.l l O o ) , which is considered to be the enol-aldo-form (11), owing toits reaction with decolorised magenta :OH*CH:CPh*CO,Et OCH*CPh:C(OH)*OEt OCH*CHPh*CO,Et(1. ) (11.) (111 )The other forms are merely mixtures of these, whilst the truealdo-form (111) has not been isolated, but may be present inalcoholic solution. The method of bromination, however, seems tooffer a ready way of solving the problem. The liquid a-form, andthe liquid obtained by melting any of the so-called solid forms,are, as usual, an equilibrium mixture, containing about 76 per cent.of enolide, probably both (I) and (11); the y-form (m. p. llOo) is apure enolide, as is also the P-form (m.p. 50.). One of these, most,probably the y-ester, is the hydroxymethylene (I). All solutionscontain the true aldo-form in equilibrium with enolides; in 50 percent. methyl alcohol as much as 91 per cent. of the ester is thealdehyde.MetaZZic Derivatives.-Although there seems clear evidence thatmost metallic derivatives of 1 : 3-diketones and such-like compoundsare salts of the enolides, the mercury compounds seem uniformlyto be derivatives of the ketones; in fact, in the case of some bis- andtris-indandiones, these salts are the only representatives of theketonic form.49 The various formulz given in the literature showthat some uncertainty still exists as to the constitution of themetallic derivatives of compounds of the malonic ester type.Although this type reacts in the same manner as the 1 : 3-diketones,no enolide can be discovered either in the liquids or in solutionsby the methods described in the foregoing. That the relation:-CH*CO*OR C:C(OH).OKdoes hold, and that the metallic derivatives are salts of the enolide,can be readily demonstrated by the bromination method, for onadding a solution in alcoholic sodium methoxide to an acidifiedbromine solution, as much as 90 per cent.of the compound appearsas enolide. The interval of one minute is, however, sufficient forthe entire disappearance of the enolide.50Bromination of Desmotrop-c Compounds.-Since Lapworth 51 ori-ginally demonstrated that the bromination of compounds containingthe carbonyl group (ketones, acids, etc.) must be a reaction betweenbromine and an enolic form, as the speed of the reaction is indepen-dent of the concentration of the bromine, and hence most probablyfixed by some slow change of the ketonic into the enolic form, little50 K.H. Meyer, Zoc. c i ~ . 49 Hantzsch, loc. cit. 51 T., 1904, 85, 30126 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.has been added to our knowledge of the phenomena until Meyer's(Zoc. c i t . ) recent application of the process as a method of estimat-ing the quantity of enolide in an e9uilibrium mixture, and therecent study of the speed of production of the chemical 'active formby means of its reaction with iodine.52 This reaction of brominewith compounds containing this group is greatly accelerated bymany catalysts (acids, bases, ferric chloride, etc.), but it offers aremarkable contrast to the action of chlorine and bromine on mostother compounds, in that it is not accelerated by light.53 This factbrings out clearly the difference between the direct substitution andthe indirect substitution, which may be formulated thus :Whether the Hell-Volhard reaction of bromine with acidchlorides, in which both hydrogen chloride as well as hydrogenbromide is eliminated, has a similar mechanism is doubtful, forhydrogen bromide and an acid chloride yield an acid bromide andhydrogen chloride.54Of the many papers which deal directly or indirectly with thesubject of this section, reference may be made to the study of thereaction of benzylamine on acetylacetone,55 of the desmotropic alkylderivatives of benzoylacetone,56 and of the so-called '' dibenzoyl-methane," 57 and to the preparation of C- and O-alkyl derivativesin general of diketones or anilides.58Quinones and Quinoneammonium Compounds.Q&n o n e-n m m o nium Corn po unds .-0 n e of the most interestingdiscoveries of the year is that of the quinone-ammonium com-pounds 59 obtained by the extreme methylation of picra.mic and ;so-picramic acids by methyl sulphate.Three methyl groups becomeattached to t,he acid, and there is no doubt that they are combinedwith the nitrogen, for the derivatives from isopicramic acid isisomeric with dinitrociimethyl-p-anisidine,~O and secondly, demetliyla-B2 11. M. Dawson and F.Powis, T., 1912, 101, 1503.53 K. H. Neyer, Bcr., 1912, 45, 2867; A , , i, 941.54 0. Aschsn, An?znZc~i, 1912, 337, 10; A . , i, 198 ; E. lfohr, J. y". C'hem.,1912, [ii], 85, 334 ; A., i, 362.L. Riigheimer and G . Ritter, Ber., 1912, 45, 1332 ; A . , i, 474.56 W. Dieckmann, ibid., 2685 ; A,, i, 868.57 B. D. Abell, T., 1912, 101, 989, 998.58 K. Auwers, Ber., 1912, 45, 976, 994 ; A., i, 484, 486.59 R. Meldola and W. F. Hollely, P., 1910, 26, 233 ; T., 1912, 101, 912.Bo F. Reverdin and A. de Luc, J. pr. Chem., 1911, [ii], 84, 555 ; A . , 1911, i,965ORGANIC CHEMISTRY. 127tion can only be effected by vigorous treatment, which would not bethe case if one methyl group were attached to a nitro-group. Thesequaternary bases both have an ochreous colour, but the p-derivativecombines with water, forming bright red crystals.The salts,however, are colourless, and very readily hydrolysed. The com-pounds are not phenolic, and have not been acylated. The remark-able colour is confined t o the nitro-compounds, for the correspondingtrimethyl derivatives of paminophenol and of 2 : 6-dibromc~paminophenol are colourless. The exact constitution of the basesis not an easy matter to determine. The colourless salts seemobviously derivatives of dinitrohydroxyphenyltrimethylammoniumhydroxide (I), but the colour of the anhydrous bases suggests somedeeper constitutional change than a simple elimination of water(IIj. The quinonoid (111) structure, alone, necessitates the use ofthe very unusual linking of quinquevalent nitrogen entirely toO H 0 ..(IK)carbon.A quinonoid formula (IV), in which an mi-nitro-group islinked to the quaternary nitrogen, would not be open to thisobjection, and also would account for the fact that only the nitro-derivatives are coloured. The constitution of the red (‘ hydrate ’’of the p-compound is yet more of a puzzle. If the ochreousanhydrous bases are “inner” salts, i t would seem necessary thatthe neutral hydrate should also have that structure; then thodisposal. of the hydrate water (hydroxyl group) is most simplyarranged for by a quinole formula (V). The fact that this com-pound has an intense colour, whilst all known quinoles, none ofwhich are, however, nitrated, are colourless, is not a special diffi-culty, since the cause of the colour of the “hydrate,” as well asof the anhydrous base, may lie in the formation of the “inner”salt.The attachment of two hydroxyl groups to the same carbonatom is not without analogy, when the carbon atom bears thesame relation as is found here, to negative groups (for example,mesoxalic acid). The adherents of the subsidiary valence hypo128 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.thesis, which has not been called into use by the authors, shouldfind no difficulty in constructing a formula which would accountfor the exact tint. The properties of these quinoneammoniumcompounds are strongly reminiscent of the quinonediazides, ofwhich the anthraquinone derivatives are now known.61 The latterare invariably coloured, but form colourless salts, which are veryextensively hydrolysed.Assuming the absence of colour in thesalts to be due to their benzenoid diazonium structure,HO*C6H,*N2*X, i t is difficult to understand the extensive hydro-lysis. A remarkable example62 of an analogous phenomenon hasrecently been observed in 4'-hydroxy-4-diazodiphenyl,the highly unstable diazophenol is deeply coloured, and yields paleyellow, hydrolysable salts, which, however, form ruby-red hydrates(with 2H20). It is probable that similar constitutional changesare the origin of these properties. Still more striking is thesimilarity between the nitroquinoneammonium compounds and thedinitrophenylpyridinium compounds.63 An oxygen compound andthe sulphur compound, to which the formula= (VI) and (VII) areNO2 NO, NO2I O*O" \/*C5% C,H,N--- ' No", C5H5N-- I i--/\+ H\:s (or 0) f\-0NO,\/ jW.) (VIJ.) (VIII.)given, are both coloured, but form colourless, hydrolysable salts.The sulphur compound, moreover, forms a hydrate, which is farmore deeply coloured. From the resemblance to the quinone-ammonium compounds, it might be suggested, since the pyridinering is not opened, that the free base is a quinonoid " inner " salt(VIII), the colourless salts benzenoid, and the coloured hydrateof the quinole type. Since in this case the nitrogen and oxygen(or sulphur) are not respectively para or ortho to one another,and yet all the same properties are observed, the quinonoid " innersalt" structure for the free base seems the more probable.Theconstitution of the coloured " hydrates " which may be quinoles(or, it may be suggested, possibly compounds of quinhydrone type,which would harmonise with the intensified colour) is moreR. Scholl, F. Ebcrle, and W. Tritsch, Moualsh., 1911, 32, 1043 ; A . , i, 143.fi.2 E. Bamberger, Annulen, 1912, 390, 131 ; A., i, 691.63 F. Reitzenstein and J. Rothschild, J. pr. Cliem., 1906, [ii], 73, 257; A . ,1906, i, 454 ; T. Zincke and G. Weisspfenning, J. pr. CIzcm., 1910, [ii], 82, 1 ;i b i d . , 1912, [ii], 85, 211 ; A., 1910, i, 585; 1912, i, 302ORGANIC CHEMISTRY. 129uncertain; it is significant that neither have hydroxyl groups beenrecognised, nor the molecular weights determined.o-23enaopuinones.-A large number of derivatives or homologuesof o-benzoquinone have now been prepared, but the colourlessform?& in which the parent substance was originally obtained, hasonly been once again observed (3 : 4-toluquinone).Kehrmann 66urges that there is as yet not even sufficient evidence to concludethat the two forms are isomeric, much less desmotropic, andsuggests that the colourless compound is possibly the first phasein the oxidation of catechol, thus:or even a compound of the quinone with ether.Besides the study of many reactions of the quinones, a verylarge amount of preparative work is being done in the anthracene,phenanthrene, and other series of quinones or quinonoid compounds,of which this indication must suffice.Some Phthalyl Derivatives.Phthalyl Chloride.-The evidence on which the asymmetricconstitution of phthalyl chloride rests has been again examinedin detail,66 with the result that the symmetric formula is favoured.The proximity of the eCOCl-groups in phthalyl chloride is con-sidered as s d c i e n t cause for such reactions as that with ammonia,in which o-cyanobenzoic acid is formed, instead of a diamide.Thereactions with ethyl sodiomalonate and sodioacetate supply thechief grounds for this opinion, since, for example, the constitutionsof the two malonic compounds are best expressed by the formulae:Preliminary work with a few dichlorides seem to show thatabsorption spectra will be of use in distinguishing between thetwo types of constitution of this and similar dichlorides. Thisview has found definite proof in Ott's *7 elaborate investigation ofcertain acid chlorides of dibasic acids, which mainly deals with theconstitution of maleic and fumaric dichlorides.As criteria todistinguish between the lactonic and the symmetric formulze, theIX R. Willstatter and others, Ber., 1911, 44, 2171, 2182 ; A . , 1911, i, 728, 729 ;C. L. Jackson and G. L. Kclley, Amer. Chem. J., 1912, 47, 197 ; A., i, 275.Ber., 1911, 44t, 2632; A . , 1911, i, 883.cB Scheiber, Annalen, 1912, 389, 121 ; A . , i, 559 ; Ber., 1912, 45, 2252 ; A , ,6/ Annulen, 1912, 392, 245 ; A , , i, 828.REP.-VOL. IX. Ki, 701130 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.rates of reaction with aniline and methyl alcohol are taken, aswell as the molecular volume, which is known to drop by aboutfour units in the formation of a lactone ring.Both these testsindicate that ordinary phthalyl chloride is symmetrically con-stituted. Further, the author has been able to convert phthalylchloride by heating with aluminium chloride into an isomeride, acrystalline solid, melting a t 88-89O. By distillation, prolongedheating a t looo, or in the presence of hydrogen chloride, it isreconverted into the ordinary chloride. It reacts with aniline andmethyl alcohol far more slowly than the ordinary chloride, andis taken to be the asymmetric chloride:The interaction of phthalic anhydride and hydroxylamine yieldstwo isomeric oximes,a one colourless and the other yellow, whichare mutually convertible the one into the other.Both can berecrystallised, and yield red alkaline solutions, from which therespective oximes can again be isolated, and also distinst ethylethers and acetates in which the colour persists. The colour isdue mostly, if not entirely, to fluorescence. The evidence seemsin favour of stereoisomeric formulz :,--CO--, ,---co---,0-C-C,H, O-C-C,H,HO-k! andM*OHAs a contraet to these observations, the two differentlyvarieties of phthalylhydrazides, which are normal andcolourednot dso-compounds, -have been shown to be polymorphs, and notisomerides.69The chromoisomerism exhibited by a number of imides andhmides of dibaisic acids has been investigated by means of theabsorption spectra of solutions. The identity of the spectra ofdifferently coloured solid forms is taken to indicate the absenceof chemical isomerism. Thus, on this criterion, the yellow andwhite forms of pmethoxyphenylphthalimide itre not chemicalisomerides, whilst p-methoxy- and p-ethoxy-phenylmaleinimides,and the corresponding phenylfumardiamides, each of which existin two forms, are.7068 W.R. Orndorff and D. S. Pratt, Amer. Chem. J., 1912, 47, 89. CompareLassar-Cohn, Annalen, 1880, 205, 295 ; A . , 1881, 585, and R. Meyer and S. M.Kissin, Ber., 1909, 42, 2825 ; A., 1909, i, 652.69 F. D. Chattaway and D. F. S. Wiinsch, T., 1911, 99, 2253.7O A. Piutti and E. de’Conno, dlem. B. Accad. Lincei, 1911, [v], 8, 793 ; A., i,360 ; compare Piutti and Calcagni, Rend. Accad. Sci. Fis. Mat. Napoli, 1910, [iii],16, 255 ; A., 1911, i, 124ORGANIC CHEMISTRY.131Benzeins a n d PhthaZeins.Phenolphthalein.-Although there has been much discussion asto the constitution of the salts of phenol- and other phthaleins,71which cannot be considered as final, the formula of the phthaleinsthemselves has not been called in question, but von Baeyer’sformula generally accepted. When tested by the very strikingway of ascertaining the presence of “ active ” hydrogen (hydrogenlinked to oxygen, nitrogen, sulphur), which has been devised byB. Odd072 on the basis of Sudborough and Hibbert’s73 originaluse of Grignard’s reagent for estimating hydroxy- and amino-groups, phenolphthalein does not appear t o contain an activehydrogen at0m.7~ Moreover, it should be noted that throughouttho phthalein series the carbonyl group of the lactone ring isindifferent to Grignard’s reagent, with which phenolphthalein doesnot react.On the other hand, one active hydrogen is found inthe monopotassium salt, the iminophenolphthalein, and in thediacetyl, but none in the triacetyl derivative. I n fluorescein,however, two active hydrogen atoms are indicated. Since the usualformula for phenolphthalein, as well as that for fluorescein, showstwo hydroxyl groups, it is argued that the former requires modifi-cation. The formula (I) is suggested, which represents the com-pound as having an ether-like constitution, but it is hinted thata still more revolutionary formula (11) may represent free phenol-phthalein. The monopotassium salt (111) would still be repre-/-\\-/(I. 1 (11.) (111.)santed by the quinonoid formula most generally accepted. Thecause of the different structures of phenolphthalein and fluoresceinis sought in the fact that in the latter the benzene nuclei carryingthe hydroxyl groups become fixed by the formation of theanhydride, whereas in the former free rotation is possible, andt h e most stable arrangement is found in the formula (I) suggested.Recent work on the use of phenolphthalein and its derivativesas indicators76 brings out the fact that the presence of negative71 Ann.IZeprt, 1909, 66.73 T., 1904, 85, 933 ; ibid., 1909, 95, 477 ; Th. Zerewitinoff, Ber., 1907, 40,93 ; 1912, i,74 Ber., 1911, M, 2018; A., 1911, ii, 826.2023 ; 1908, 41, 2233 ; 1912, 415, 2384 ; A., 1907, ii, 509 ; 1908, i,841.74 B.Odd0 and E. Vassallo, Gazzelta, 1912, 42, ii, 204 ; A., i, 792.75 E. Rupp, Arch. Phnn., 1911, %9, 56; A., 1911, i, 301; J. W. McBain,K 2T., 1912, 101, 814132 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.groups in the phthalein nucleus, but not in the phenol nuclei,sharpens the colour change, that is, increases the rapidity of theformation of the coloured quinonoid form, and hence increasesthe value of the phenolphthalein as an indicator. The preparationof colourless monobasic and tribasic salts 76 from phenolphthalein,which contain water or alcohol, may perhaps be taken as evidencethat only the formation of the dibasic salts causes the developmentof the colour, thus : .-.Phi%ateins and Benzeins.-The complicated isomerism in thephthaleins and benzeins has been accounted for by F.Kehrmannand others 77 by constitutional formula: showing quadrivalentoxygen; the salts with acids are held t o be, on the one hand,oxonium salts (I), or, on the other hand, from the similarity withthe salts of triphenylmethyl, generally carbonium salte,78 (11),thus, in typical formulze:? 0A new light has, however, been thrown on the problem by vonLiebig's 79 final demonstration that some, if not all, of theisomerides are, in fact, easily resolvable polymerides, the correctmolecular weight of which is only found in certain solvents(acetone) ; the polymerides are, however, sufficiently stable to yieldsalts and other derivatives.In the formulze of these compoundsoxygen is not represented as quadrivalent, but the author isobliged to fall back upon limitations to the free rotation of thephenyl groups, about the central methane carbon atom, to whichthey are singly linked, in order t o account for the existence ofthe certain isomeric unimalecular fluoresceins. The polymeridesare considered to be of a quinhydrone type, and analogous to the76 P. A. Kober, and J. T. Marshall, J. Amer. Chem. SOC., 1911, 33, 59 ; 1912,34, 1424 ; A., 1911, i, 300 ; 1912, i, 865 ; R. Meyer and k'. Pouner, Bet.., 1911,44, 1954 ; A., 1911, i, 654.77 A., 1900, i, 61 ; Annalen, 1910, 372, 287 ; A,, 1910, i, 406 ; Ber., 1912, 45,3346, 3504 ; A., i, 1012.Vt( M. Gomberg and collaborators, Annalen, 1909, 370, 142 ; A., 1910, i, 55 ;J.Amer. Chem. Soe., 1911, 33, 1211 ; A , , 1911, i, 737.79 H. von Liebig, J. pr. Chem., 1912, [ii], 85, 97, 241 ; 86, 472 ; A , , i, 376ORGANIC CHEMISTRY. 133compounds of benzeins with alcohol and other hydroxy-compounds.Thus, y-resorcinolbenzein, 4C,,H,,O,,H20, which only loses watera t 240°, is given a quinhydrone formula:0 OH 0 0 OH 0-4s will be seen from the formulze, these quinhydrones are represented by definite structural formulae, with full atomic linkings;in fact, in discarding subsidiary linkings, the author is reverting toC. L. Jackson'.s original formula for quinhydrone 80 :0 OH/\/The salts with acids are not regarded as oxonium nor as carboniumderivatives, although the acid radicle is attached to carbon (rV),but it9 compounds of the quinhydrone type.It is admitted thatthe solubility in water of these salts is a difficulty, but it issuggested that in solution they are represented by (111). Basinghis conception on von Baeyer's81 recent discoveries on the methodof opening up the dimethylpyrone ring, the author considers thatthe formation both of the salts and of the quinhydrone additivecompounds is brought about by the hydrolysis of the anhydridering; the varying, sclcalled, " basicity " of this class, which isadmittedly not commensurate, a5 is usual, with the character ofthe substituents, is merely a question of the readiness with whichthis hydrolysis occurs :(111.)Diaao-corn pounds.The data of the absorption spectra of a large number of diazo-compounds of various types which have been accumulated byseveral observers make it now possible to associate the constitutionsgo Ber., 1895, 28, 1614 ; A., 1895, A., i, 513.Annalcn, 1911, 384, 208; A., 1911, i, 901134 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of the different classes with certain characteristics of the spectra,and to state the modifications in the typical spectra produced bythe presence of certain groups or radicles.Moreover, by this meansthe current conceptions as to the constitution of many diamcompounds can be checked, or in some cases corrected.82The diazo-compounds are by their absorption spectra divided intotwo groups, the diazonium salts and the azo-compounds. Thediazonium derivatives possess a characteristic deep band in theultra-violet, the exact position and intensity of which is modifiedby, but the character of which remains unchanged by, substituents.The coloured and colourless salts are quite similar in this respect,and hence have the same constitution, a view which is now heldby G. T.Morgan,m on the ground of chemical behaviour. Thispowerful selective absorption is attributed by Hantzsch to theinteraction between two “ unsaturated centres,” 84 which producesa peculiar vibratory molecular state. H e represents it by ancillarylinking or subsidiary valence. I n this case the tervalent nitrogenof the diazo-group is linked to the benzene nucleus by such avalence, thus: Ar-N-X. This structure is, however, not the same“d I 1NIas, or even similar to, Cain’s 85 quinonoid diazo-formula, N2., ‘ .,=\I __ /\--Ifor the nucleus is supposed to retain its benzenoid type, and nonitrogen-bridge linking to be formed.It is pointed out that theso-called diazo-phenols show a very different and characteristicabsorption, which is taken to indicate that they have a quinonoidstructure, not a benzenoid with a bridge linking, a formula which&/-\.‘k*,\-/has again recently found adherents. At the same time this differ-ence in the absorption between the two types is an argument for thebenzenoid structure of the diazonium salts.The spectra of the azo-compounds is quite different from that ofthe diazonium salts, and is, moreover, extremely variable. Theazo-group does not appear to be an “independent ’’ chromophore,but resembles the carbonyl, only to a higher degree, in its depend-ence on the groups to which it is linked.The azo-paraffins have anultraviolet absorption band, and the azo-benzenes have, in addi-tion, a “colour” band in the visible spectrum. Prom the great82 A. Hantzsch and I. Lifschitz, Ber., 1912, 45, 3011 ; A . , ii, 1116.83 T., 1910, 97, 1961, 2537 ; compare ibid., 1907, 91, 1311.8% See also A. K. Macbeth, A. W. Stewart, and R. Wright, T., 1912, 101, 599.85 T., 1907, 91, 1069ORGANIC CHEMISTRY. 135similarity of the diazomethane derivatives to azo-compounda, theN cyclic formula for the group >C<- - is preferred to the formulaN>C:NiN, suggested by Angeli and Thiele.86The isomeric azocyanides, Ar*N,.CN, and azosulphonates,rnAr*N,*SO,M*, behave as stereoisomerides, showing a nearly identi-cal absorption.The two series of diazotates show, however,considerable difference, the normal or (( syn "-salts showing no ultra-violet band. Further, i t is to be noted that faintly alkaline solu-tions of diazonium salts in which it has been asserted that thediazohydrate (normal) is present, are now shown by the absorp-tion to contain the diazonium hydroxide. This fact suggests thatthe conversion of the diazonium into the diazo-constitution whichwas offered as an explanation of many diazo-reactions (transforma-tion into phenol, chlorobenzene, etc.), does not a t least find con-firmation in this searching analytic method.The free iso(anti-)diazohydrate can be obtained in solution, showing absorptionidentical with that of its salts, but quite different from that of thenitrosoamines, the absorption of which resembles rather that ofthe normal diazotates. The opinion is expressed, however, thatthe normal and isodiazotates are stereoisomerides, and that thedifference in the spectra is to be attributed to the peculiar chromephoric character of the azo-group. It will be seen, however, thatit is just where a decisive proof was most needed that some uncer-tainty still remains.The evidence for the existence of the primary nitrosoamines asthe +-acids of the isodiazotates, Ar*N:N-OM f Ar-NH-NO., hasagain been examined, more particularly in the case of pnitrodiazo-benzene, and a remarkable effect of solvents discovered. I n ether(or alcohol) the absorption is that of an isodiazotate, but in chloro-form that of a nitrosoamine; moreover, the compound cannot beextracted from the latter solution by alkali, but only after additionof ether.88 Although the absence of any equilibrium mixture insolution is very singular, if not unique, the reciprocal conversionof one isomeride to the other seems to take place with the rapiditywhich would be expected of such a change.Some Reactions of Diazo-compounds.-The actions of sodiumarsenite and a mixture of potassium cyanide and sodium hydrogensulphide afford unusually clear chemical distinctions between thegG Atti 2.Accnd. Lincei, 1911, [v], 20, i, 625; A., 1911, i, 620 ; Ber., 1911,441, 2522, 3336; A, 1911, i, 845; 1912, i, 16.87 J.J. Dobbie and C. K. Tinkler, T., 1905, 87, 273. Private cominunicationsfrom C. H. Desch.E. Bamberger and 0. Baudisch, Bcr., 1912, 45, 2054 ; A., i, 733; A.Hantzsch, ibid., 3036 ; A., i, 1039136 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.various classes of diazo-compounds. With diazonium salts, thenormal diazotates, and the labile diazosulphonates, the diazo-groupis replaced by hydrogen:Ar*N:N*ONa + Na,AsO, + H20 = ArH + N2 + Na3As04 + NaOHAr*N:N*ONa + NaSH + KCN + H,O = ArH + N, + KGNS + 2NaOH,whilst the isodiazotates, the stable diazosulphonates, and azo- andaeoxy-compounds do not react. A constitutional difference for thetwo sulphonates, Ar*N2*O*S02K and Ar-N,-SO,K, is revived toaccount for this distinct reactivity ; and am-formulze are suggestedfor nitrosoacet- and nitrosobenz-anilides, Ar*N2*O*Ac, since theyreact whilst the nitroso-derivatives of amines do n0t.89Two of the simplest derivatives of azo-benzene, o-hydroxy- 90 ando-amino-azobenzene 91 have been prepared by convenient methods ;the former is obtained by coupling diazonium salts with p-acetyl-aminophenol, and the latter, of which derivatives have also beenobtained?, by condensing benzoyl-pphenylenediamine with nitroso-benzene.Aniline-black and Allied Compounds,Since aniline-black was last dealt with in the Annual Reports(1909), the two chemists who are authorities on this subject, Greenand Will~tlitter,~3 have maintained a long controversy as to theexact nature and relations of aniline-black, or perhaps more accu-rately, of tho primary products of the oxidation in which aniline-black is ultimately formed.Since Willstatter’s discovery 94 thatone-eighth of the nitrogen appears as ammonia on treatment of anyof the products with acids, it has been generally agreed that anoctzmuclear indamine-like complex is the parent substance, theleuco-fomrm of which (‘( leucoemeraldine ”), C48H42Ns, is representedby the annexed formula:The four coloured compounds derived from this contain respec-tively one, two, three, and four quinonoid nuclei. Inasmuch as allB9 A. Gutmann, Ber., 1912, 45, 821 ; A., i, 398.im J. T. Hewitt and W. H. Ratcliffe, T., 1912, 101, 1765 ; N. N. Voroschtsoff,91 F.H. Witt, Ber., 1912, 45, 2380 ; A., i, 921.;93 R. Willstatter and C. Cramer, BET., 1910, 43, 2976 ; A., 1911, i, 90 ; Ber.,1911, M, 2162; A . , 1911, i, 736; A. G. Green and A. E. Woodhead, T., 1910,97, 3388 ; 1912, 101, 1171 ; Ber., 1912, 45, 1955 ; A. G. Greenand S. Wolf€, Bcr.,1911, M, 2570 ; A . , 1911, i, 900.J. Rzus. Php. Chem. SOC., 1911, 43, 787; A., 1911, i, 818.G . M. Norman, T., 1912, 101, 1913.O4 Bar., 1909, 42, 2147, 4118 ; A , , 1909, i, 585, 976ORGANIC CHEMISTRY. 137these compounds are unstable and amorphous, and cannot be puri-fied by recrystallisation, the difficulties experienced in demonstrat-ing, much more in defining, these stages, has been very great. Will-statter relied on the quantitative reduction with the evolution ofnitrogen of the quinonoid nucleus by phenylhydrazine as a meansof measurement; but Green has shown that although accuratewithin certain limits of temperature, 80-90°, phenylhydrazineitself decomposes rapidly a t the temperatures which were used ;hence the conclusions were falsified.On the other hand, the oxida-tion of titanium chloride appears to be a more trustworthy guide;i t reduces each of the quinOnoids to the leucecompound, and notmerely to the monoquinonoid stage as was first believed.The colour-bases are all completely soluble in 80 per cent. aceticacid; their salts, with the rise in the number of quinonoid nuclei,are respectively grass-green, green, blue, and purple. The namesproto-emeraldine, emeraldine, nigraniline, and pernigraniline aresuggested for the four stages in oxidation.These compounds areunstable, and pernigraniline especially readily becomes degradedto a lower quinonoid stage. In attempts to purify, treatment withpowerful reagents, strong acids, cause, besides degradation, theformation of insoluble compounds. This instability, as well as thecolour, indicates that none of these compounds is aniline-black ;they are rather to be regarded as intermediaries in its formation.It may be suggested that aniline-black is a quinhydrone-like complexof one or more of them.Tripheny 2me thane Dyes ana? Tri p h e r y Erne t 7~ y 2.The discussions on the constitution of this group of compoundsis so closely connected with the problem of the relation betweencolour and constitution that the recent evolution of ideas on thissubject will have to be mentioned.H. Kaufhann has recently developed in a monograph 95 views asto the interatomic linkings in aromatic (and other) compounds,which are suggested by their varying behaviour in a Tesla electricfield.96 H e regards the benzene nucleus as a structure in which theinteratomic relations are most delicately balanced, and hence highlysensitive to the influences of substituents.I n this way groups actas auxochromes in varying degrees by causing changes in thechromophoric aromatic nucleus, with consequent changes in theabsorption of light (Kauffmann’s ‘‘ Auxochrome theory ”). Thesechanges are not, however, the simple conversion from the benzenoidto the quinonoid structure, but they are a t once more varied andg5 “ Die Valenzlehre,” 1911 ; Bcr., 1912, 45, 766, 781 ; A ., i, 351, 397.96 3w., 1900, 33, 1725 ; 1901, 34, 682 ; A , , 1900, i, 480’; 1901, i, 318138 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.more complex; thus in order to show the influence of a substituenton the nuclear structure, he represents dimethylaniline by theformula :in which the substituent is connected with four of the carbon atomsof the nucleus. The collection of the sub-valencies on certain atomsis looked upon aa determining the well-known direction given to asecond substituting group.It is in particular in this extreme division of the valence unit(“ Valenzzersplitterung ”), brought about by auxochromic groups(which is a t least in part merely an extension of the use ofsubsidiary valencies), that the author sees the cause of colour.Attention has been called to the fact that auxochromes are not, asmight be expected on this theory, always similarly effective; theaction holds for the aromatic series, but in the aliphatic thesegroups rather decrease selective absorption.97 The particular appli-cation to the triphenylmethane dyes well illustrates Kauff mann’sviews ; thus pararosaniline (I) and aurin (11) are represented thus :C H -NH,,f / 4- /C,H,--NH,C-C H -NH,X C6H,--NH2(111.)\ 6 *The single valenceunit of the anion.is divided in this ca.se intofour parts, which are not necessarily equal, but determined by thestrength of the auxochromic group; in the breaking up of the fourvalence-units of the central carbon atom lies the cause of thecolour.The three benzene rings are exactly alike and each modifiedto an equal extent, whereas in Fittig’s formula one only is quino-noid, and on von Baeyer’s theory98 each is successively quinonoidin the vibratory movement of the molecule, to which the colouris ascribed. One of the difficulties of the usual quinonoid formulais the fact that the salts of pararosaniline are not hydrolysed, whilstin general the salts of such $-bases containing the carbirninechromophore, *C:NH,HCl, are highly unstable. Again this theoryeasily represents the fact that on weakening the auxochromicgroups (by acetylation) the colour fades, and the molecule may besupposed to pass over finally into Rosenstiehl’s formula (III).W97 A.Hantzsch, Ber., 1912, 45, 3036 ; A , , ii, 1116.Q8 Annalen, 1907, 354, 164 ; A., 1907, i, 757.99 Compt. rend., 1895, 120, 192, 264, 331, 740 ; Bull. SOC. chim., 1895, [iii], 13,427, 431 ; A., 1895, i, 377, 476, 667ORGANIC CHEMISTRY. 139The intense halochromy of hexamethoxytriphenylcarbinol and evenof hexamethoxytriphenylmethane, would be anticipated from thegreat auxochromic subdivision of the carbon valence.1As a result of his study of the coloured compounds of metallicsalts, mainly tin tetrachloride, with the carbonyl group, Pfeiffer 2has arrived a t somewhat similar views as to the development ofcolour. I n these compounds the metallic salt or acid (called the(‘ addendum ”) unites co-ordinatively ” a t the carbonyl oxygen,X,Sn*- ....O:CRR,, thereby neutralising free affinity and renderingthe carbonyl carbon more unsaturated. The appearance of un-saturation is the cause, the degree determining the intensity ofd o u r . Hence it must depend both on the addendum and on thenature of the groups R and R’. A very large body of facts hasbeen gathered together, which affords a remarkable confirmation ofthis proposition. According to Kauff mann’s theory, the addendumwould be united both to the carbon and oxygen (and to otherpoints in the groups R and R’, or to any auxochromic groups),and the consequent breaking up of the carbon valence, which, itmust be remembered, also occurs in the increase of (I unsaturation ”of Pfeiffer, gives rise t o colour.The hypothesis of Pfeiffer has theadvantage in that these additive compounds are, in fact, more,not less, reactive, and hence more unsaturated than the originalcarbonyl derivatives ; thus the catalytic hydrolysis of an ester byan acid is accounted for by the attachment of water to the carbonylcarbon, thus :,.- 0: CRR’?EtR-C:O..---.H’I >H20Moreover, when such a (‘ ternary ” compound can be produced, andthe unsaturation of the carbon atom thereby diminished, it isfound that the colour fades. This theory can be used as Kauf€-mann’s to account for the colour of the triphenylrnethane dyes,without the assumption of the change of a benzenoid to a quinonoidnucleus, and of triphenylmethyl and the corresponding carbinolsalts.Trip~eityZmet7tyZ.-Schlenk’s 3 discovery of the unimoleculardeeply-coloured tridiphenylmethyl, (Ph*C6H4),C, supported by J.Piccard’s4 demonstration that the yellow colour of a solution ofH.Kauffinann atid F. Kieser, Ber., 1912, 45, 2333 ; A., i, 853.P. Pfeiffer, AnnaZcn, 1910, 376, 285 ; 1911, 383, 92 ; A., 1910, i, 852 ; 1911,AnnnZen, 1910, 372, 1 ; A , , 1910, i, 236.Ibid., 1911, 381, 347 ; A, 1911, ii, 561.i, 788140 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.triphenylmethyl in absolute ether increased on dilution, has con-firmed the suggestion 5 that the coloured (solutions) and colourlessforms of the latter are simply the coloured triphenylmethyl andthe colourless hexaphenylethane, which exist in the equilibrium :P h P hPh/ \PhP h b C L P h -- 2 PI@.The colour is therefore not to be ascribed to the presence of aquinonoid nucleus in a coloured bimolecular form, the ionisationof which in solution (sulphur dioxide) into quinonoid andbenzenoid triphenylmethyl is regarded by Gomberg 6 as thecause of the conductivity.On Pfeiffer's hypothesis the colouris merely caused by the unsaturation of the methyl carbon atom.I n an equally simple manner the appearance of colour in thetriarylmethyl salts (for example, triphenyl- or trianisole-methylchloride) in acid solution, or when combined with metallic salts oracids, is attributed t o the decrease in the saturation of the centralcarbon atom, and not t o the constitutional change which is shownin Gomberg's carbonium formula, Ph,C:C6H4<C,.i1 A remarkabledifference7 has been found ta exist between the absorption spectra,of t.he coloured non-conducting solutions of triphenylmethyl and ofthe conducting triphenylcarbinol or triphenylmethyl derivatives(salts) ; apparently the ion, Ph,C*, has a characteristic spectrum.Whether these facts can be harmonised with the above viewsremains to be seen. The authors regard this contrast, not as indi-cating a constitutional change, but as being in favour of vonBaeyer's 8 suggestion of a special ionisable carbonium valence,represented thus : Ph,C-X, in the triphenylmethane salts.The discovery of two isomeric tridiphenylcarbinols,( C6H5m C6H4) 3 ' OHand coloured unimolecular tridiphenylmethyls, respectively preparedfrom them, does not simplify the problem; once more the onlysuggestion offered is that one isomeride has an ionisable carboniumvalence, whilst the other has not?The simple amine bases of the triphenylmethane series,J.Schmidlin, Ber., 1908, 41, 2471 ; A., 1908, i, 623.6 M. Goniberg and collaborators, ibicl., 1907, 40, 1847 ; A., 1907, i, 504 ; ibid.,1909, 42, 406; A., 1909, i, 144; J. Amar. C'hem. soc., 1911,b 33, 531, 1211 ; A . ,1911, i, 361, 737.7 I<. H. Meycr and H. Wieland, ibid., 1911, 44, 2557 ; A., 1911, ii, 952.Ber., 1905, 38, 572; A., 1905, i, 281.J, Schmidlin, ibid., 1912, 45, 3171 ; A., 1913, i, 3ORGANIC CHEMISTRY. 141NE,*CAr,, which have for the first time been prepared,lo resemblethe carbinols so closely that they have probably been often over-looked.Ar,C*NH, + 2HC1 ZT Ar,CCl + NH,CI,but on making alkaline the triarylmethylamine is again obtained.With alcohols a carbinol ether is produced in a quantitative reac-tion, which can be used to estimate the amino-group:R3G'*NH2 + EtOH = R,C*OEt + NH,.The auramines, Ar,C:NH, which are very strong bases, offer aremarkable contrast in their stability to the triarylmethylamines.11With acids they yield dyes and an ammonium salt:Fluorescence.As an illustration of the general theory of fluorescence of organiccompounds (the luminophorefluorogen theory l2), the influence ofamino-groups as auxochromes (fluorogens) in fluorescence has beenfully studied in the case of the methyl amino- and 2 :5- and2 : 6-diamino-terephthalates.13 The displacement of the fluorescentband towards the red is most marked in the diamines, more especi-ally when the amino-groups are in the para-position with respectto one another.On acetylation or benzoylation the weakening ofthe auxochrome causes a reverse movement of the band; that is,in terms of the theory, the connexion by means of subsidiaryvalence of the nucleus (the lwninophore) with the amino-group(the auxochrome or fluorgene) is diminished. The investigationof the effect of numerous solvents on the fluorescence of thesecompounds makes clear the fact that the fluorescent colour exhibitedby a given substance depends on the dissociating power of thesolvent. The fluorescence is both intensified and of longer wave-length in alcohols and acetic acid, whilst the position of the bandis either unchanged or even shifted towards the blue by chloroform,benzene, and hexane.These effacts are, however, only marked whenstrong auxochromes are present. Carbon disulphide stands apartin nearly extinguishing all fluorescence. Among fluorescent com-pounds, methyl dimethylamiuoterephthalate is also an exceptionin that it only shows fluorescence (blue) in inactive non-dissociatingsolvents-a property which has been used to show that tin tetra-ethide belongs to this class of solvent. The author merely statesthat all these new observations are in accord with his general theoryof fluorescence.la V. Villiger and E. Kopetschni, Ber., 1912, 45, 2910 ; A . , i, 1030.i1 L.Semper, Annulen, 1911, 381, 234; A . , 1911, i, 577.l2 H. Kauffmann, Ber., 1907, 40, 838; A., 1907, ii,{ 215. See also Ann.l3 H. Kauffmann and L. Weissol, Annulen, 1912, 393, 1 ; A., i, 863.Beport, 1907, 10142 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The fact that ( ? 2 : 5-)dicyanodihydroxy-p-benzoquinone, whichhas recently been prepared by the action of alcoholic potassiumcyar.ide on chloroanil,l4 is strongly fluorescent, is difficult to explainon Kauffmann’s theory, as quinones are not luminescent, and hencenot luminophores. It is suggested that in spite of the markedcolour, the compound has a peroxide, and not the typical quinonoidstructure.An attempt16 has been made this year to formulate a generalmolecular theory of fluorescence (and phosphorescence).It isassumed that a molecule, more especially a complex molecule, mayexist in several states, in which the subsidiary valence is “satis-fied” t.0 different degrees. In the final stable state, the “residualaffinity” reaches a minimum when the maximum satisfaction ofthe subsidiary valence with the consequent loss of free energy hasbeen attained. From analogy this process is spoken of as thecondensation of the lines of force which radiate from each atom asa centre. By the absorption of light, energy is provided for the‘‘ opening up ” of the system. By the selective absorption of lightof wave-length, $, the stages 1 and 2 are brought into photo-dynamic equiiibrium. I n solution in a suitable solvent it is possibleto produce the phase (3) with absorption of light, A,. Now it isconceived that the process 1 +2 brought about by the absorptionof A*, must disturb the whole system, and as one of the possiblevibrations of the system has a frequency corresponding with A,, solight of wave-length A, will be emitted-and hence fluorescence.Very striking evidence is found in the fact that o-aminobenz-aldehyde and other similar compounds absorb in alcoholic hydro-chloric acid solution (that is, in the “opening up ” 2 -+ 3), lightof the same wave-length as they emX as fluorescence in alcoholicsolution. Moreover, it is suggested that the development of colourin concentrated sulphuric acid solutions of triphenylcarbinol maybe accounted for in the same way,since the fluorescent light of thealcoholic solution is identical with the light absorbed in sulphuricacid solution, without resource to the hypothesis of a quinonoidstructure.This suggestion as to the structure of these salts, it willbe noted, is identical with that reached by Kauffmann and Pfeifferon other grounds.This thwry has been effectively criticised from the point of viewof the Mass Law.16 It is urged that in any such system as postu-lated in the foregoing, there must be equilibrium between thevarious states, 1 -- 2 --- 3, whether when constantly illuminatedor not. Hence a “ balance of light ” would be attained in addition14 M. M. Richter, Ber., 1911, &, 3469 ; A . , i, 34.15 E. C. C. Baly and R. Krulla, T., 1912, 101, 1469.16 A. K. Macbeth, P., 1912, 28, 271ORGANIC CHEMlSTRY.143to the original absorption effect. The same argument may beapplied to the absorption of each subsequent “state” which isinduced in the system; but emission finds no place. The fluorescencewhich only occurs a t low temperatures, and the fact that the wavelength of the exciting light may vary over a wide range withouteffecting that. of the fluorescence, can also not be brought intoaccord with the theory.Hydroaromatic Compozmds, Terpenes, and ,4 llied Compounds.Physical Comqtants and Constitution.-The systematic study ofphysical constants has long been used as a supplementary guidein assigning constitutional formula: to members of the terpeneseries. Recently, work on the absorption spectra and on therefractivity emphasises the great assistance which may be expectedfrom these properties.A vivid controversy17 between the sup-porters of the respective methods has served to show that theabsorption spectra are more delicately sensitive to slight constitu-tional differences, for example, the degree of conjugation of a pairof double linkings,l8 but that the refractivity indicates with preci-sion the different types of double linking. The purity of theterpene can be accurately gauged by means of the absorptionspectra, very slight differences (0*lo) in the boiling point beingreflected in the spectra. As an example of the results of thestudy of the absorption spectra of three isomeric p-menthadienes,limonene (A’ :S) has less absorptive power than terpinolene (A1:4(*))and terpinene.As the absorptive power of the two latter isnearly identical, it is proposed to revert to the former symbol(A1:*) for terpinene, notwithstanding the fact that the chemicalevidence is decidedly in favour of the Harries’ formula (A1:3). Asthe result of much laborious statistical work, data of refraction anddispersion have now been collected,lD which render possible a sharpdifferentiation between endocyclic and semicyclic double linkings inhydroaromatic and similar compounds. Endocyclic unsaturatedcompounds are optically normal, whereas a semicyclic double linkingcauses an exaltation, both of the specific refraction and specificdispersion. I n a number of pairs of isomeric hydrocarbons, whichhave keen compared, alkylidenecy clohexanes with alkyl-A1-cyclo-l7 K.Auwers, Ber., 1911, 44, 3525 ; 1912, 46, 963; A., ii, 4; ii, 505; A,Hantzsch, Ber., 1012, 46, 663, 569, 1742 ; A , , ii, 313, 709.l8 C. R. Crymble, A. W. Stewart, R. Wright, W. G. Glendinning, and MissF. W. Rea, T., 1911, 99, 451, 1262.l9 K. Auwers and F. Eisenlohr, Ann. a p o r t , 1910, 67 ; 1911, 51 ; K. Auwersaud W. Moosbrugger, Annalen, 1912, 387, 187 ; A . , ji, 213; K. Auwers andP. Ellinger, ibid., 200; A., i, 187 ; K. Auwers, Ber., 1912, 45, 2764, 2781 ; A . ,i, 2013, 1016144 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.hexenes, the specific exaltation of the semicyclic compounds amountsto 0-28-0*47 of 8,, and to 6-10 per cent. of P,-S,. A1-cyclo-Hexenylacetic acid and its derivatives are optically normal, whilstthe isomeric cyclohexylideneacetic acid and its derivatives show aneven greater exaltation than the hydrocarbons-a behaviour whichis attributed to the conjugated double linking present with the semi-cyclic linking.It is suggested that the constitution assigned tomany hydrocarbons is in this respect erroneous; for example, manyof Sabatier and Mailhe's alkylidenecy clohexane derivatives are,in fact, endocyclic hexenes ; and Zelinsky and Gutt's 3-methyl-l-ethylidenecyclohexane must be 3-methyl-1-ethylcyclohexene.20Among the numerous observations which have been recorded,the depression in refractivity which is not accompanied by a, similardepression of the dispersing power, of unsaturated five-memberedrings, containing the group *CH:CH*CH:CH-, is shown to holdfor homocyclic as well as heterocyclic compounds.21 Previously theoptical abnormality of cyclopentadiene was thought to be due toits ready polymerisation, but the monomeric form, which is nowfound to be not difficult of preparation,2z gives similarly low opticalconst ants.In a similar manner Ostling 23 has made measurements and accu-mulated data of the refractive and dispersive powers of compoundspossessing a cyclopropane or a cyclobutane ring ; twenty-five of theformer and sixteen of the latter class were available.The incre-ment in the molecular refraction ( M a ) due to the closing of thecyclopropane ring is +0*67, and to the closing of the cyclobutanering + 0.45. The molecular dispersion is unaffected.The conjuga-tion of the cyclopropane ring with a double linking raises thevalue of the increment somewhat, but the effect of this conjugationis not perceptible when an alkyl or alkyloxy-group is attached to acentral carbon atom of the system. Data are now available formaking a preliminary comparison as to the relative sensitiveness ofmolecular refraction and magnetic rotation to constitutive influ-ences :Change in Change iiimolecular in ag u e t icrefract iou. rotation.- 2.2 - 0.6 Formation of 5- or 6-monibered ring ......,, ), cyclopropane ring ............ - 1 . 5 - 0.5,, ,, a double linking ........... - 0-5 $. 0.7cyclo 0 c tat e traen e .-T he preparation of cy clooct atet r aene, whichis one of the most remarkable discoveries of the year, by Will-'Lo Ber., 1902, 35, 2142 ; A ., 1902, i, 585.21 K. Auwers, ibid., 1912, 45, 3077 ; A . , i, 956.22 H. Stobbe and I?. Renss, Annulen, 1912, 391, 151 ; A . , i, 842.23 T., 1912, 101, 457OKGAXIC CHEMISTRY. 145stLtter 24 and Waser from N-methylgranatenine, C,H,,*NH*CH,obtained from the alkaloid t)-pelletierine, was achieved by use ofthe ve.ry elegant method of eliminating two atoms of hydrogenfirst used in preparing cycloheptadiene from suberone.2sFrom the quaternary methylammonium base from N-methyl-granatenine, cyclooctatriene (I) was obtained by distillation in ahigh vacuum:The scheme shows the series of changes in which the tetraene isfinally isolated.I n a similar manner 20 cyclohexanol was converted into benzene.The A1:3-cycZohexadiene,” which was passed en route, can be pre-pared in this way in a purer state than by treatment of cyclohexenedibromide with quinoline :C,H,,*OH -+ C,H,,, -+ C6H10B~*2 --+ C,H9*NSi~2 --+ C’,,H, --+C6H813r2 -+- C6H8(NMe,), -+ CtiH6.The octatetraene a t higher temperatures undergoes a rearrange-ment to an isomeride, which is unsaturat.ed, but no longer has fourdouble linkings, nor can be reduced to cyclooctane, but only to theconipounds C&t1, o r C,H,,.The most probable explanation of thischange is that a, more stable configuration has been produced withthe formation of a di- or tri-cyclic compound :FH*YH*C]WEHCH:CH.CH.CFi’ orSH * yH*CH: KCH*CH*CH:CRThis fact has led t o the suggestion that caoutchouc (dehydro-caouprene) has a similar cyclic structure 28 :Reducing Agents.-There has been much discussion during theperiod under review as t o the efficacy and trustworthiness of the24 Bey., 1911, 44, 3423 ; A ., i, 17.‘35 Ibid., 1901, 34, 129 ; A , , 1901, i, 223.26 Ibid., 1912, 441, 1464 ; A . , i, 544.a A. W. Crossley, jT., 1904, 85, 1103; C. D. Harries, Ber., 1912, 45, 809,2586 ; A., i, 343, 842 ; N. D. Zclinsky and A. Gorsky, Ber., 1911, 44, 2312; A.,1911, i, 847.2s I. von O~tromisslensky, J. Rim. Phys. Chrm. SOC., 1912, 44, 204 ; A., i, 280.REP.-VOL. 1X. 146 ANNUAL REPORB ON THE PROGRESS OF CHEMISTRY.reducing agents which are in use for the addition of hydrogen t ocyclic carbon compounds. Wallach 29 has pronounced in favour ofPaal’s reagent, that is, colloidal palladium (or platinum) and hydro-gen?O as being less prone to cause constitutional change than anyother.Willstatter,31 on the other hand, presses the advantageof platjnum-black and hydrogen preferably in the presence ofacetic acid-a reagent to which attention has been drawn byFokin.2 I t is claimed that this method is far superior to that ofSabatier and Senderens,% in that the hydrogenation is quantitative,and can be carried out a t the ordinary temperature. There seems,however, to be as yet some difficulty in its application,3* but this isascribed to the presence of sulphur compounds (for example, thio-phen), which inhibit the reduction of such compounds as benzene,naphthalene, benzoic acid, etc., but only retard the reduction ofcyclic olefines, such as limonene.It is noteworthy that caoutchoucdissolved in benzene is not attacked by this reagent, but the solventis reduced t o hexaiie if the caoutchouc be not vulcanised.s5Numerous applications36 of this method to the most diverse typesof compounds are €ound in the literature of the year; and a criticalinvestigation to determine the best procedure has been made bySkit a .37The synthesis of nitriles of this series by the interaction ofmagnesium alkyl bromides and cyanogen is also noteworthy; itoffers a means of preparing saturated cyclic nitriles, acids, and soforth.38During the period under review, continuous progress has beenmade with the syntheses of o-, m-, and pmenthenols, and thecorresponding menthadiene~.~g An interesting method 40 of preparingbenzo(p1ieno-)cycloheptadienes is found in the condensation of2 : 2’-dimethyldiphenyl-ww’-dicarboxylonitrile under the influence of29 Annulen, 1911, 381, 51 ; A., 1911, i, 469.3o C.Paal, A . , 1905, ii, 397, 533 ; 1907. ii, 559 : 1908, i, 599 ; 1909, i, 926 ;3l Ber., 1911, 44, 3423 ; ibid., 1912, 45, 1164, 1471; A., 1912, i, 17, 544,32 J. Russ. Phys. Chem. SOC., 1908, 40, 276, 700 ; A . , 1908, i, 311 ; ii, 637.s3 Compare G . B. Neave, T., 1912, 101, 513.a H. Wieland, Ber., 1912, 45, 484, 2615; A., i, 247, 956.55 F. M’. Hinrichscn and R. Iiempf, ibid., 2106; A . , i, 687.36 L. C. Kelber and A. Schwarz, ibid., 1946 ; A., i, 617 ; A. Kiitz and E. Schrreffer,87 Ber., 1912, 45, 3312, 3.579, 3589 ; A ., 1913, i, 53, 54, 63.38 V. Grignard and E. Bellet, Comnpt. rend., 1912, 155, 44; A . , i, 623.39 W. H. Perkin, jun., and others, T., 1911, 99, 118, 518, 526, 727 ; G. G.Henderson and R. Boyd, Z’., 1911, 99, 2159.40 J. Kenner and Miss E. G. Turner, ibid., 2101 ; P., 1912, 28, 277.1912, i, 703 ; A. Skita and H. Ritter, Ber., 1910, 43, 3393 ; .A., 1911, i, 71.545.ibid., 1952 ; A., i, 603ORGANIC CHEMISTRY. 147sodium ethoxide, when 1-imino-2-cyano-3 : 5-dibenzo-Aa : 6-cyclohepta-diem was obtained :/\ i i ,,-%,I C:NH.What promises to be a very useful general method of convertingketones and aldehydes into hydrocarbons has been found41 in theaction of alcoholic sodium ethoxide on the semicarbazones orhydrazones :The temperature must be fairly high, 16O-2OO0, but the amountof sodium ethoxide which apparently acts catalytically is of littleimportance. Fenchone and camphor are nearly quantitativelyconverted into fenchane and camphane respectively.The problem of the conversion of unsaturated hydrocarbons tocyclic isomerides, the technical importance of which is of peculiarinterest a t the present time, was fully discussed in last year'sreport (pp.107-108). The exact work on the polymerisation,42more especially of as-dimethylallene, (CH,),C:C:CH,, to cyclo-butanes, has led to interesting results. Two types of dimerides arepossible :>C:N*NH*CO*NH, + >C:K*NH, -+ >CIl,+N2.andy ' y : Cc*c:cy*f.':cc:c.c 'with three isomerides of each type.The three cyclobutanes of thefirst type have now been obtained by correct choice of conditions,and their constitutions settled by oxidation with ozone, but thereis no sign of the dimerides of the second type.The first example of the direct synthesis of a meta-linking in asix-membered ring is the formation of the norpinone 43 (bicycle-1 : 1 : 3-heptanone) :CHCH,*yB*CH,CH,*CH*CH, I c;*I *(11.) (111.)CH2(1.141 L. Wolff, Annalen, 1912, 394, 86 ; A., i, 988.*2 S. V. Lebedeff, J. Buss. Phys. Chem. Soc., 1910, 42, 949; 1911, 43, 820,1735; A . 1911, i, 26, 774; 1912, i, 173 ; compare H. Stobbe and F. Reuss,Anna.len, 1912, 391, 151 ; A., i, 842.43 0. Stark, Ber., 1912, 45, 2269 ; A., i, 868.L 148 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The distillation of the calcium salt of homohexahydroisophthalicacid results in the formation of a bicyclo-1 : 2 : 2-heptan-&one (II),44whilst similar treatment of the barium hexahydroterephthalate issaid to yield the isomeric bicycloheptan-7-one (IIJJ.46 Stark uses asimilar method, namely, the distillation of calcium hexahydroisoaphthalate.The reaction with bromine excludes the presence of adouble linking, and hence of six- or seven-membered rings witha double linking as possible constitutions.Ozonides and Ozozomides.-The abnormally large addition ofoxygen which has frequently been observed in the combination ofozone with double linkings has now found an explanation in thediscovery that ordinary strongly ozonised oxygen, “ 14 per cent,ozone,” contains another polyatomic molecule, oxozone, probably04, besides ozone.40 On washing crude ozone with sodium hydr-oxide and sulphuric acid, when the oxozone is destroyed, theabnormalities disappear and pure ozonides are obtained.Anozonide, RO,, is not converted into an oxozonide, RO,, by “ mixed ”ozone, hence pure oxozonides can only be prepared when theirrate of formation is much speedier than that of the ozonides. Sofar this condition has only been found in the case of caoutchouc.The decomposition products of the oxozonide, CI0Hl6O8, are thesame as those of the ozonide, but there is a greater proportion oflmn.dic acid than aldehyde.Terpenes a d Allied Compounds.-Of the very large number ofpapers, having as their subject the terpenes or ethereal oils, byfar the greater proportion describe the extraction of these sub-stances from various natural sources which have in recent yearsbecome more accessible.The methods of procedure appear to bebecoming standardised ; but the intricate chemistry of this vastgroup is not sufficiently explored to allow of the recognition ofmany of the compounds which have been isolated.Campherre.-Since this puzzling member of the terpene series waslast mentioned in the reports (1910), several investigators havebeen engaged with the attempt to solve the problem of its constitu-tion. There seems now no doubt as t o its individuality, and,moreover, that the materials obtained from all natural sources I areidentical.47 Wagner’s formula (I) has steadily risen in favour,replacing Semmler’s (XIV), mainly owing to the simplicity of theoxidation of camphene by ozone 48 ; dimethylnorcampholide and44 G . Komppa arid T.Him, Uer., 1903, 36, 3610 ; A . , 1904, i, 60.45 N. D. Zelinsky, ibid., 1901, 34, 3800.46 C. D. Harries, Zeilsch. Elektrochem., 1912, 18, 130 ; A , , ii, 343; Ber., 1912,45, 936 ; A . , i, 407 ; Annaien, 1912, 390, 235 ; A . , i, 673.47 0. Aschan, Annalen, 1911, 383, 1, 3 9 ; A., 1911, i, 794, 796.48 F. W. Semmler, Bcr., 1909, 42, 246, 962 ; A , , 1909, i, 170, 312 ; C. D. Harriesan3 J, Palmhn, Ber., 1910, 43, 1432 ; A., 1910, i, 497ORGANIC CHEMISTRY. 149camphenilone, the products, are certainly represented by theformulz (11) and (111), since the latter has been converted intothe acid (IV), the constitution of which has been demonstrated bydirect synthesis.49 Among other difficulties in the way of acceptingWagner's formula is the fact that some 70 per cent.of the productof oxidation of camphene is camphenic (" camphenecamphoric ")acid.60 The constitution of this acid was given by Aschan, whoproposes the formula (V) on the grounds that it only formed amonobromo-derivative, which could be converted through anunsaturated acid (VIII) to a hydroxy-acid (VII), which does notform a lactoDe. Moreover, the unsaturated acid yields the lactoneof a, tribasic acid (IX), the constitution of which was based on theresults of alkali-fusion. W. N. Haworth and A. T. King 51 have,however, synthesised in a simple manner a lactone of this constitu-tion, which differs unmistakably from Aschan's compound.Hencemuch of the evidence for the constitution ascribed to camphenicacid fails. Haworth and King suggest that since a second isomerideof the acid is known,52 Aschan's acid may have the constitution(XI), when camphenic acid would have the formula (XII).The formation from bornylene (XIII) of camphenilanaldehyde,which can be prepared simply by several different methods fromcamphene, as well as other considerations, has led G. G. Hendersonand I. M. Heilbron 53 to urge that the carbon-skeleton of campheneand bornylene is more closely related than is shown by Wagner'sand Aschan's (VI) formulae, and to suggest the revival of Semmler'sformula (XIV), as that which permits the formation of thealdehyde, with the least rearrangement from both hydrocarbons.CH,*yH-C Me,CH, CH-C: C H,(1.)CH,*QH*CHMe,CH,*CH* C0,H(IV.1CH,*?H-?Me,UH,*CH-CH1 Q"2 II QH2I FH2 fiHw.1CH,*~H-~Me, CH,*C]H-CMe,C'H,*CH-CO 1 F H 2 I CH,*CH---CO I QH2 v(11.1 (111.)CH,-~H*CMe,-CO,H CH,°FH*CM~,*CO,HCH,*CH*CO,H I QRzUH,*C(OH) *CO,H I ?"2(V. 1 (VII.)CH,*QH*CMe,* C0,H CH,* Q( CO,H)*CMe,*CO,RCB,*C*C02H I ? CH,*CO I FiH(VIII.) (IX. 149 L. Bouveault and G. L. Blanc, Compt. rend., 1908,147,1314 ; A., 1909, i, 108.50 0. Aschan, Annalen, 1910, 375, 336; A., 1910, i, 709.51 T., 1912, 101, 1975.53 W. H. Perkin, jun., and J. F. Thorp, ibid,, 1901, 79, 764.53 T., 1911, 99, 1887, 1901150 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.CH,-F]O CH,--F]( C0,H) *CH,*CO,HCMe,* C (C0,H) CH,* CO,H I ? CMe,*CO I ?(X.) (XI.)C H2--Q H*CH,*CO,H CH,*?Me-CH CH,*$!Me-x,CMe,* CH* C0,HI QRle,,CH:CH,CH,*CH-(XII.) (XIII.) (XIV.)CH,*QMe-\ CH2*QMe-\CH,*bH -I FMe2 I I CH,*CH-CH I FH2I CMe, / ‘CH*CHO I FMe2,COC‘H,*CH--(XV.1 (XVI.)This view necessitates an alteration of the formula of bothcamphenilanaldehyde and camphenilone [Henderson’s and Heil-bron’s formula3 are respectively (XV) and (XVI)]. That of thelast-named seems, however, fairly certain, and has found confirma-tiori on further recent study.%A very striking light is thrown on the constitution of campheneby its spectro-chemical properties.65 It shows a molecular opticalexaltation or increment (M,) of +2*12, which, as was stated in theforegoing, could not be caused by an endocyclic, but only a semi-cyclic ethylene linking. Moreover, the exaltation which has beenshown to be caused by a tricyclic linking, whether in cyclopropanederivatives,m or in terpenes (cyclene, etc.), does not exceed +0.9;hence camphene cannot be a saturated compound possessing such astructure.Finally, the normal refractivity of isocamphane 67(dihydrocamphene) demonstrates that the increment cannot beattributed to the carbon-skeleton of camphane. Aschan’s formulaseems, therefore, to be excluded in favour of Wagner’s, or possiblySemmler’s, both of which have a semicyclic ethylene linking.Canzphor.-Among the numerous researches dealing with deriv-atives of camphor, some of which have rather a secondary objec-tive, the investigation of the behaviour of the various groups,weighted by the camphor complex,m or a study of morphotropicrelations,59 attention may be directed to the reinvestigation, which54 S.V. Hintikka and G. Komppa, Annalen, 1912, 387, 293 ; A., i, 2i8.55 K, Auwers, ibid., 240 ; A., ii, 214.56 G. J. Ostling, T., 1912, 101, 457.57 P. Lipp, Annulen, 1911, 382, 285 ; A,, 1911, i, 731.68 M. 0. Forster and collaborators, T., 1911, 99, 478, 1982 ; 1912,101, 1327 ; A.Haller, Compt. rend., 1912, 154, 742 ; A, i, 359 ; J. Bredt, Ber., 1912, 45, 1419 ;A., i, 411 ; J. pr. Chern., 1911, [ii], 84, 786 ; A., i, 112.59 W. H. Glover and T. M. Lowry, T., 1912, 101, 1902ORGANIC CHEMISTRY. 151is accompanied by a re-naming, by Noyes and his pupils,80 of thedegradation products of camphor.It seems that in the formationof the cis- and trans-hydroxydihydrocampholytic acids from amino-dihydrocampholytic acid,if the stereoisomerism of the hydroxy-acids is accepted, change ofthe type of the Walden inversion occurs. It is worthy of mentionthat the period under review has seen the close of a famous contro-versy concerning the synthesis of camphoric acid61; i t is nowadmitted that Komppa’s synthesis 62 is well founded.Another isomeride of camphor, epicamphor, or j3-camphor,which has recently been preparedF3 but by somewhat inconvenientprocesses, has now been obtained easily from methyl bornylenecarb-oxylate.64 With hydroxylamine this compound yields the hydrox-amic acid, C,,,H,,-C(OH):NOH, which on heating decomposes intoepicamphor and ammonia.Both the stereoisomerides of isonitroso-epicamphor, together with other nearly-related compounds, havebeen prepared through phenyliminocamphor from camphorquinone,of which all the oximes are now known.65is&amphor.-A very interesting discovery has been made byWallach66 with regard to the constitution of this isomeride ofcamphor. Under conditions, the use of colloidal palladium, whichadmit of no profound change, it has been found that the reductionof isocamphor gives dihydropinolone, which is l-acetyl-3isopropyl-cyclopentane. Hence isocamphor, which is not identical with pinolone, is a l-acetyl-3-isopropylcyclopentene,>CH,YH,--CAcCH,*CHPrPfor which the name isopinolone is suggested.* J .Amer. Chem. SOC., 1912, 34, 62, 174, 1067; A . , i, 159, 786.61 G. L. Blanc and J. F. Thorpe, T., 1910, 99, 2010 ; Q. Komppa, ibid., 29.82 Ann. Pikport, 1904, 112.63 F. R. Lankshear and W. H. Perkin, jun., P., 1911, 27, 166 ; J. Bredt and W.64 J. Bredt and W. H. Perkin, jun., P., 1912, 28, 56.65 M. 0. Forster and H. Spinner, T.? 1912, 101, 1340.66 Annalcn, 1912, 392, 49 ; A,, i, 879 ; compare Annalen, 1911, 3M, 198 ; A,,Hilbing, Chem. Zeit., 1911, 35, 765 ; A . , 1911, i, 657.1911, i, 891152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Natural Products.Tannin.-With the synthesis 67 of compounds which closelyresemble tannin a great advance has been made in the attemptto determine the chemical nature of this substance.Although itwas originally supposed that tannin was a compound of sugar andgallic acid,68 the view that the essential constituents of the materialwas a digallic acid has found general acceptance, and alone appearsin the textb~oks.~g The low acidity, small electrical conductivity,and high molecular however, render this hypothesis unten-able, and, moreover, have led Nierenstein71 to abandon his viewthat tannin was a mixture of digallic and leucodigallic acids. Hisnew formula represents tannin or tannins as polygalloylleucodigallicanhydrides 72 :the optical activity being due to the leucodigallic acid, and not tothe presence of a glucose residue. Fischer and Freudenberg havesatisfied themselves (Zoc.c i t . ) that purified tannin contains a smallproportion (7-8 per cent.) of dextrose, which cannot be presentas an impurity, and to which they ascribe the optical activity. Theisolation of a crystalline glucogallic acid as a companion of tanninin certain galls as collateral evidence may be recorded.73 Theysuggest that tannin is therefore a penta$igalloylglucose,7* whichshould yield 10.6 per cent. of dextrose,[c6s2( OH),*CO*O*C6H,( OH)2CO]5C6H706.This compound is to be regarded rather as an ester than as aglucoside. Starting from tr&ethylcarbonatogalloyl chloride anddextrose, a pentagalloy$$ucose, [~6H2(OH)3*CO],,C,H706, wasprepared, which had the greatest resemblances to tannin, in taste,optical activity, slight acidity, colour reactions, and the power offorming precipitates with gelatin and alkaloids.Moreover, methyl-tannin, which is prepared from diazomethane and tannin, is identi-cal with the material obtained from pentamethyldigalloyl chloride0’ E. Fischer and K. Freudenberg, Ber., 1912, 45, 915, 2709 ; A . , i, 471, 887.@ A. Strecker, Annulen, 1852, 81, 245 ; ibid., 1854, 90, 328.1 3 ~ H. Schiff, Ber., 1871, 4, 232, 967 ; ibid., 1879, 12, 33.70 P. Walden, ibid., 1897, 30, 3151 ; 1898, 31, 5167.jrl Ann. &port, 1909, 107 ; Ber., 1908, 41, 77 ; 1909, 42, 1122 ; 1910, 43, 628 ;A., 1908, i, 90; 1909, i, 897; 1910, i, 265; compare R. J. Manning arid M.Nierenstein, Ber., 1912, 45, 1546 ; A., i, 666.72 AnnaZen, 1912, 388, 223 ; A., i, 468.73 K. Feist, Ber., 1912, 45, 1493 ; A , , i, 566.7r Compare H.C. Biddle and W. P. Kelley, J. Amer, Chem. Soc., 1912, 34,918 ; A., i, 713ORGANIC CHEMISTRY. 153and dextrose (Fischer and Freudenberg). Hence methyltannin,?6which is a mixture probably of two stereoisomerides, is a penta-[pentamethyl]digalloylglucose. It is noteworthy that by this methodcompounds of very large molecular weight can be synthesised ;thus there is no difficulty in preparing the compound from tri-benzoylgalloyl chloride and glucose with a molecular weight ofnearly 3000.76Damascenine.-The synthesis 77 of damascenine, the “ alkaloid ” ofATigeZZa dumascena, has proved that Keller’s 78 “ betaine ” formulais incorrect. Damascenine is methyl 2-methylamino-3-methoxy-benzoate, which Reller isolated, but believed to be the methylderivative of the alkaloid.Scopole tin.-Another natural product, the constitution of whichappears t o be finally settled, is scopoletin; this compound is2 : 4-dihydroxy-5-methoxyphenylpropionic acid, and can be con-verted with ease either into 2 : 4-dihydroxyanisole or 2 : 4-dihydroxy-5-methoxycinnamic acid.79The most cursory perusal of the foregoing review in this sectionwill show that much that is both important and interesting in theyear’s work is not even mentioned.I n making a selection of thesubjects to be reviewed, the extent to which they have been dealtwith in the reports irnmediately preceding, has been taken intoaccount; thus the organic compounds of arsenic and sulphur werefully considered last year, whereas little reference was made to theterpenes and hydroaromatic group.Moreover, it is obvious that alarge proportion of the work in organic chemistry must be givensimply to exploration; vast numbers of compounds which arepossible on our present theories still remain to be prepared. Theexplorers mainly follow well-beaten tracts, and the new groundwhich is mapped out by a familiar procedure only occasionallyshows features which differ more than in details from that alreadybroken. That such work is absolutely necessary, and when con-sidered as a whole forms a fine monument of achievement, is shownby several well known classic examples, but it does not lend itselfto review a t very frequent intervals.KENNEDY J. P.OBTON.75 J. Herzig, Ber., 1908, 41, 2890 ; A . , 1908, i, 183 ; Monatsh., 1909, 30, 543 ;1912, 33, 843 ; A . , 1909, i, 713 ; 1912, i, 792.76 See also H. Crompton, P., 1912, 28, 193.77 A. J. Ewins, T., 1912, 101, 544.0. Keller, Arch. Pharm., 1904, 242, 299 ; 1908, 2416, 1 ; A., 1904, i, 768;C. W. hlnore, T., 1910, 97, 2224 ; 1912, 101, 1043,1908, i, 283154 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.PART III.-HETEROCYCLIC DIVISION AND STEREOCHEMISTRY.The notable features of the year’s work appear to have been theadvances which have been made in the study of alkaloids, and alsothe growing tendency to apply the conceptions of physical chemistryto the study of stereochemical problems. I n the latter classmention may be made of the investigations of the Walden inversionmechanism, and also Michael’s application of the entropy principleto stereoisomerides.These and kindred researches suggest that wemay shortly see a considerable augmentation of interest in stereo-chemistry, and many of the problems which were left unsolved bythe older methods may yield t o the newer methods of attack.The AIkaloids.Summaries of alkaloid chemistry are exceptionally difficult to.produce in any circumstances, owing to the intricate nature of thesubject; and in the current year the task has been rendered evenless easy thsn usual, for the progress during the last twelve monthshas been very marked, and consequently an enormous amount ofmaterial has accumulated which is very hard to weld into a con-nected whole without expending too much space.A selection oftypical advances has, therefore, been made, preference being givento those points which lend themselves best to concise treatment. A tthe same time, it is hoped that a fair conspectus of the field as awhole has been furnished.I n view of the controversies which have arisen from time to timewith regard to the natural syntheses of alkaloids which go on inplants, it is not without interest to find that Paternb and Maselli,lin the course of their studies in photochemistry, have discoveredthat when acetophenone is dissolved in a concentrated alcoholicsolution of ammonia and then exposed to sunlight for severalmonths, a 20 per cent. yield is obtained of a substance whichappears to resemble the natural alkaloids in many respects.Thisproduct has the composition C,,H,,N,, gives rise t o various salts,and forms a nitroso-derivative. Up to the present, its constitutionhas not been determined.The simplest alkaloid synthesised during the year appears tobe damascenine,2 which h’as the structure :NHMe OMeCo2Me(--> .Gazzelta, 1912,42, i, 65 ; Atti R. A d . Llincei, 1912, [v], 21, i, 235; A., i, 295.Ewins, T., 1912, 101, 544ORGANIC CHEMISTRY. 155Strictly speaking, this compound does not fall into the presentdivision of the subject, but it has been included on account of itssimple structure and for the sake of completeness.I n the tropine gr0~p,3 a substance hitherto termed $-hyoscyamine,and regarded as an isomeride of hyoscynmine, has recently beenproved to be really nor-hyoscyamine, differing from hyoscyaminein having no methyl group attached to the bridge nitrogen atomin the ring:CH,* 7 H-7 €3, C H , - ~ H - - - ~ H , VaH,CH2-CH-CH, CH,*OH CH,*CH---CH, CH,*OHThia relationship has been established by the following treatment.It was shown that the alkaloid contained no N-methyl group,whilst it formed a nitrosecompound, thus proving that it was asecondary amine.The action of methyl iodide on it produced amethyl derivative, which was found to be identical withZ-hyoscyamine. Hydrolysis with barium hydroxide yielded tropicacid and nor-tropanol. Just as hyoscyamine is racemised and formsatropine, so nor-hyoscyamine can be converted into the opticallyinactive nor-atropine.I n physiological properties there is a con-siderable difference between hyoscyamine and nor-hyoscyamine, thenew alkaloid being eight times less active than the former inmydriatic action.I n the group of the cinchona alkaloids, various workers havestudied the intramolecular changes which these substances can bemade to undergo. Bottclier and Horovitz4 find that when quinineis heated a t looo with sulphuric acid, two bases result, which theyterm A and B; and these compounds are also formed when quinineis treated with hydrogen iodide. It appears that the base B isidentical with Lippmann and Fleissner’s isoquinine.5 A somewhatsimilar treatment seems to convert quinine and cinchonine intotheir poisonous isomerides, quinotoxine and cinchotoxine ; for whena salt of quinine is heated at 95-98O in aqueous solution, withor without excess of acid, it undergoes rearrangement with theproduction of quinotoxine.6 Cinchonine gives the analogouscinchotoxine.The velocity of the rearrangement appears to dependto a great extent on the strength of the acid employed; weakacids seem to favour the process, whilst strong acids, such as hydro-Carr and Rejnolds, T., 1912, 101, 946.Monatsh., 1911, 32, 793 ; 1912, 33, 567 ; A., 1911, i, 1011 ; 1912, i, 717.Ibid., 1891, 12, 327; A., 1892, 81.Biddle, Ber., 1912, 45, 526 ; A., i, 296 ; Rabe, ibid., 1447, 2927 ; A., i, 488,I TH FH*O*CO*7H 1 YMe ~ H - O * C O * ~ HNor-hyoscyaniine. Hyoscyaminc.1014156 ANXUAL REPORTS ON THE PROGRESS OF CHEMISTRY.chloric, inhibit it. Even at a temperature of 36O the changetakes place, although more slowly; and the same may be said forthe exposure of salt solutions to direct sunlight a t the ordinarytemperature.Similar results were obtained with other membersof the cihchona group.Mention may be made of some preliminary synthetic experi-ments7 in the cinchonine group, but the results could be satisfac-torily dealt with only by entering into greater detail than spacepermits.The group containing narcotine and its allies has been the centreof a considerable amount of investigation during the year. It willbe remembered that Liebermann 8 endeavoured t o producenarcotine by condensing together hydrocotarnine and opianic acid ;but that, instead of the expected product, he obtained a substance,isonarcotine.The constitution of this substance has now beenexp1ained.Q When hydrocotarnine (I) is treated with form-aldehyde, the hydrogen atom left unsubstituted in the benzenering ( 5 ) is attacked lo; and this suggested that in the condensationwhich leads to isonarcotine the same hydrogen atom might be theone which becomes replaced by the opianyl radicle. To prove this,hydrocotarnine was brominated, thus exchanging the labilehydrogen atom for a bromine atom and producing bromohydro-cotarnine (11). An attempt was made to condense the latter com-pound with opianic acid, but no reaction took place. This provesMe0 C'H, Me0 CH,(I. ) Hydrocotarnine. (11.) Bromohydrocotarnine.Me0 CH,' I / b oI \ )MeGMe(111.) GoNarcotine.CH,6H.OOMe(IV. ) Narcotine.7 Rabe, Ber., 1912, 45, 2163 ; A., i, 718.Ber., 1896, 29, 184, 2040 ; A., 1896, i, 264.9 Freund and Fleischer, ibid., 1912, 45, 1171 ; A ., i, 490,10 Freund and Daube, ibid., 1183 ; A,, i, 491ORGANlC CHEMISTRY. 157that some factor is missing in the bromohydrocotarnine which ispresent in hydrocotarnine itself; and the missing factor can onlybe the labile hydrogen atom which is present in hydrocotarnine.The constitution of isonarcotine may therefore be written as shownon p. 156 (111), and the formula for narcotine is given in (IV) forcomparison.I n connexion with the isonarcotine condensation, another pointmight be mentioned. Liebermann employed 73 per cent. sulphuricacid as his condensing agent; but later work by Kersten11 showedthat concentrated hydrochloric acid might also be used with goodeffect.The use of this reagent in the coiidensation of phenolicethers appeared to Jones, Perkin, and Robinson12 t o leave somedoubt as to the identity of products obtained in this way; andthey have therefore investigated the behaviour of various etherswhen submitted to condensation by this method. The results showthat the reaction takes the ordinary course, so that a possibleobjection to the isonarcotine structure was thus removed.The behaviour of narcotine when submitted to the action ofheat in various solvents13 has shown that decomposition ensues inalcoholic, aqueous, or acetic acid solution, whereas mineral acidshave but little influence,The condensation of cotarnine with nitromeconine produced asubstance, nitrognoscopine.14 This work has now been continued,’6and it is found that when the nitro-compound is reduced to anamino-derivative, the latter yields a hydrazine, which, on oxidation,is converted into an isomeride of gnoscopine.It is suggested thatT-narcotine should be termed a-gnoscopine, whilst the new stereo-isomeride should be called B-gnoscopine; and there is reason tobelieve that the a-modification corresponds with racemic acid, andthe fl-form with i-tartaric acid. Similar reactions16 have beenapplied to the preparation of anhydrohydrastininemeconine withvery good results. Gnoscopine17 appears to be produced whennarcotine is heated in various solvents for long periods.I f a Grignard reagent prepared from ethylene bromide andmagnesium is allowed to act on hydrastinine,lB two isomeric dihydro-hydrastinines are produced, which owe their isomerism to spatialdifferences.This reaction is similar to that discovered19 in thel1 Ber., 1898, 31, 2099 ; A., 1898, i, 702.l2 T., 1912, 101, 257,l 3 Rabe, Bcr., 1912, 45, 2927 ; A . , i, 1014.14 Hope and Robinson, P., 1910, 26, 228.l5 ]bid., 1912, 28, 16.17 Rabe, Ber., 1912, 45, 2927 ; A., i, 1014.1s Preuud arid Shibata, ibid., 855 ; A . , i, 488.1Q Freund and Kupfer, AnnnZen, 1911, 384, 1 ; A . , 1911, i, 911.l 6 X d . , 17I58 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.case o€ cotarnine. The case is somewhat complicated by thepresence of a methyl group attached to a nitrogen atom in thering ; and there is a possibility of cis-trans-isomerism entering intothe question. I f we assume such isomerism, two isomeric meso-forms of the substance would be possible.A general method whereby hydrastinine bases may be obtainedfrom berberine derivatives has been devised,zO the outline of whichis as follows.The dihydroberberine derivative (I), in which Rrepresents an alkyl, alkaryl, or aryl radicle in the a-position, isconverted into the tetrahydro-compound (II), then into thequaternary compound (111), and finally into the ammonium base(IV) and the $-base. Further elimination of water may then takeplace, or oxidation will convert the base into derivatives ofhydrastinine (V) :C,H&O,N + H2 = @2$32$304N(1.) (11.)C20€&,R0,N + Me1 = C2,H2,R04NMeIC,H2,R04NMeOH = H,O + C2,H,,RO4NMe(IV.) ( V .)( 1 11.)Turning now to thO berberine group, a comparison of theformuh of berberine (I) and hydrastine (11) will show that a(I. ) Berberine. (11.) Hyclrastine.O-CH, /\ACH I I/\/\/\/hZeO!,/,), I )CH2Me0 CO CH,(111.) Oxyberbcrine.close relationship exists between the two. Hydrastine is evidentlythe lactune corresponding with the unsaturated acid which wouldbe obt.ained if 8, methyl group could be attached to the nitrogenatom of oxyberberine (111). With a view to producing thischange,21 oxyberberine was submitted to the action of methyl iodideFreund, D.R.-P. 241136; A., i, 383.Bland, Perkin, and Robinson, Z'., 1912, 101, 262ORGANIC CHEMISTRY.159in the presence of water, but the ultimate product appears to bean isomeride of oxyberberine, which probably has the structurerepresented by :0-CH, /\;,CH I I/\/\(/\,/I '''eo(/\/NH CH:CI-I,i~w0xyberberiue.The function of the methyl iodide is apparently merely t ofurnish hydriodic acid, the presence of which is necessary to thereaction, for the conversion of oxyberberine into isooxyberberinecan equally well be produced by heating oxyberberine with hydrclchloric acid.Other work in the berberine series includes the preparation ofnumerous derivatives of berberine and tetrahydroberberine.22A considerable amount of attention has recently been paid tothe harmine group of alkaloids.Perkin and Robinson 23 considerthat the following formula, since it affords an explanation of thereactions of harmine, must be very close to the actual constitutionof the substance :Me0 COOMe/\I I CH CHHariniue. apoHarmine.If this view be-correct, then apoharmine should have the secondformula above, which is 2-methylindole in which one of the methinegroups of the benzene ring is replaced by a nitrogen atom. Suchcompounds containing a fused pyridine-pyrrole nucleus areunknown; and as each ring might be expected to modify the other'sproperties to some extent, the further experiments in the synthesesof such substances will be awaited with interest.Now when the methoxy-group is eliminated from harmine,24 abase, harman, is obtained, which, on the Perkin-Robinson view,would have either of the structures (I) and (11), according asharmine cont.ains a quinoline or an isoquinoline nucleus.To throwFreund, D.R.-P. 242217 ; A , , i, 487.ZJ T., 1912, 101, 1775.24 0. Fischer, CEem. Centr., 1901, i, 957 ; A., 1901, i, 405160 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.some lightit is foundto it. Theon this, the latter substance has been synthesised,25 andnot to be identical with harman, although very similarnew substance (11) has therefore been termed isoharman.CH/‘\I I (3rd\ \/\\/\/A/\/\\ I I 1 C*CH,\/\/\/ < I C-CH,N KH N NH(1.1 (11.1From these results, i t may be concluded that harmine itself containsan isoquinoline nucleus i19 shown above, and not one containing aquinoline group.It has been shown26 that, by heating harmic acid to 250--380°in a vacuum there is obtained from it apoharminecarboxylic acid,which in turn a t 330° decomposes with loss of carbon dioxide,yielding apoharmine.Frdm these results i t is deduced that harmicacid is apoharmine2 : 3-dicarboxylic acid. A new base 27 has beenprepared from upoharmine by applying Hofmann’s reaction. Thedecomposition does not take the usual course, but results in theformation of a substance containing four atoms of nitrogen, whichappears to be trimethyldiupoharmine. It has also been shownthat apoharmine csn be reduced to a tetrahydro-derivative inaddition to the dihydro-compound already known.28Some harmaline derivatives have been synthesised by 0.Fischerand Boesler.20P-Saphthasdphonium-quinone and the Sulphides of P-XaphthoE.When the a-sulphide of 8-naphthol, HO*C,oH6*S*C,oH,*OH, istreated with alkaline oxidising agents, i t loses two atoms ofhydrogen, and is converted into a stable scarlkt substance, firsttermed dehydro-/3-naphthol sulphide. Reduction of this leads tothe production of a naphthol sulphide, which appears to bedifferent from the original one. This series of compounds waevery thoroughly examined by Henriques,30 who was unable t o putforward any structural formulz to explain the existence of thetwo isomerides, and therefore assumed that they were stereoisomeric,the sulphur atom being supposed in some way to hinder freePerkin and Robinson, P., 1912, 28, 154.xi Hasciifratz, Conzpt.rend., 1912, 154, 704 ; A . , i, 383.27 Ibzd., 1520 ; A . , i, 577.?8 ]bid., 1912, 155, 284; A., i, 797.29 Bcr., 1912, 45, 1930; A . , i, 645.31) Ibid., 1894, 27, 2999 ; A . , 1895, i, 103ORGANIC CHEMISTRY. 161rotation of the two naphthol groups, so that the spatial formulaeof the isomerides might be written as follows :IIO*$,H6 H0*710H6B C,,H6*OH B HO* CloH,(1.) (11.1Thus, in the one case, the hydroxyl groups were on the sameside of the molecule, whilst in the second isomeride they were onopposite sides. With regard to the structure of the intermediatescarlet substance, Henriques concluded that it was a peroxide ofthe formula:C , 0 H 6 ~ ~ ? > c 1 0 H 6(111.)This structure would agree with the known reactions of thesubstance up to a certain point, and is especially suitable inconnexion with the hypothesis that the two sulphides are stereo-isomeric, since in the reduction of the peroxide it is to be expectedthat a naphthol derivative of formula, (I) (where the two hydroxylgroups are adjacent in space) would be formed in preference toone having the second formula.The investigation of this series of substances has been undertabenby Smiles and his collaborators; and their investigation has ledto wholly unexpected results.In the first place, the so-calledperoxide reacts with phenylhydrazine, forming a dihydrazone, asHenriques had shown; and this in itself tends to throw some doubton the applicability of the peroxide formula; for one would expecta true peroxide to be readily reduced by phenylhydrazine, givingthe sulphide instead of the hydrazone.Secondly, the scarlet sub-stance, when treated with alcoholic alkali hydroxide, produces anaphthathioxin. Now this result is parallel to those obtained31 inthe case of certain benzene derivatives :0 0 OH/\OH\/\ /\/\/\Me) ' I IMc -+ Me1 \ / \ / b e I \/\ /\/? ?OH OHHilditch and Smiles, T., 1911, 99, 973.REP.-VOL. IX. 162 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.so that it seems probable that the scarlet substance has thestructure (IV), and is really 8-naphthasulphonium-quinone. Anexamination of the new formula proposed for this substance showsthat it cQntains a quinonoid nucleus of a totally new type, and itsreactions are therefore of more than usual interest.When treated with hydrogen chlorideF2 the quinone is convertedinto chloronaphthathioxin ; whilst acetic anhydride in the presenceof camphorsulphonic acid gives acetoxynaphthathioxin. Takingthe case of the halogen acids, the reaction is formulated as follows:CI(V->? Q'OH blC10H6<~>~10H, * C10H6<E>C,,H6(VI. 1 (VII.)In the first place, the halogen acid attacks the quinonoid nucleus,but in 60 doing it produces a substance unstabk in the presence ofacids. This unstable substance tends to pass into a cyclic com-pound by intramolecular change; and an examination of thisintermediate compound (VI) will show that it is a $-base, whichhydrogen chloride would convert into the thioxonium salt (VII).In the presence of an alcoholic solution of sodium ethoxide, thescarlet quinone is reduced to Pnaphthol sulphide (m.p. 212O),namely, that from which the quinone was prepared. Now,Henriques, employing acid reducing agents, showed that an isomericsulphide was formed (m. p. 153O); and the possibility of a $-basebeing formed a,s an intermediate product in this reaction furnishesa clue to the cause of the different results obtained in the twocases.Turning now to the properties of the two sulphides themselves,it must be admitted that their isomerism must be of a peculiarcharacter. If the hypothesis of stereoisomerism be accepted, apostulate is made which has no parallel in stereochemistry; sothat it is clear that all other possibilities should be exhaustedbefore falling back on this.An investigation of the actions ofvarious reagents, such as sulphuric acid, potassium hydroxide, andferric chloride, on the two isomerides has been made,= and it was32 Christopher auci Smiles, T., 1912, 101, 710.3y Crymble, Ross, and Smiles, ibid., 1146ORGANIC CHEMISTRY. 163found that there are very marked differences between the twoforms. Thus, cold sulphuric acid with the stable sulphide producesnaphthathioxin oxide ; whilst the unstable isomeride yields naphtha-thiophen. A more striking difference even than this is observedwhen bromine is allowed to act on the two sulphides.34 The stablecompound yields bromo-derivatives of &naphthol, the sulphurbeing eliminated in exchange for the halogen ; the unstablesulphide, on the other hand, retains the sulphur atom and takesup three atoms of bromine in exchange for hydrogen.The tri-bromo-de,rivative formed in this last reaction readily gives uphydrogen bromide on treatment with pyridine, yielding a stablecrimson substance, which appears to be dibromonaphthasulphonium-quinone.The absorption spectra 35 of the two sulphides appear to resembleeach other to some extent in general character. Each contains twobands, which have their heads a t 3000 and 3500 units respectively.Residuul A finity and Spatid Conjugation.It is a well-known fact that when two unsaturated groups in amolecule are conjugated structurally, their mutual influence to someextent. destroys the specific character of each; for instance, thedouble bonds in the structure -C’H:CH*CTH:CH* do not behave likeordinary isolated double bonds.Now it is known that in a normalcarbon chain the positions 1:5 and 1 : 6 have certain propertieswhich lead t o the assumption that they are closely situated withregard to each other in space; and the same has been noticed withregard to the 1 :4-positions in a six-membered cyclic substance.We are thus driven to inquire whether any mutual influence canbe traced between two unsaturated groups which, although struc-turally unconnected, are placed in close proximity to one anotherin space.An examination 36 of optically active esters and salts of saturatedaliphatic acids which had two carboxyl radicles at the ends of anormal chain of carbon atoms has been made; and it was foundthat anomalous rotatory powers were shown when the carboxylgroups were in the 1 : 5- and 1 : 6-positions with regard to each other.This is an example of what is termed “spatial conjugation.’’A very complete investigation of spaceconjugation of the secondtype, in which the unsaturated groups lie in the 1 :4-position with34 Nolan and Smiles, T., 1912, 101, 1420 ; Ross and Smiles, 1912, 28, 275.35 Crymble, Ross, and Smiles, ibid., 1146.9(i Hilditch, ibid., 1909, 95, 1578.M 164 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.regard t o one another in a saturated ring, has led to interestingresults.37 The substances examined were the following :Rk 0 S 0 S S/\ /\ /'\ /\ /\ /\9 H , 9 H 2 7H2 Q", CH, CH, p z p 2 Q", QH, 7 4 FH2\/S r \/ 7CH, CH, CH, CH2 6H2 bH2 CH, CH, CH, CH, CH, CH,0\/ \/ \/ r R\/0R KPiperazines.1 : 4-Dioxan. 1 : 4-Dithian. Morpholines. 1 : 4-Thiazans. 1 : 4-Thioxan.and it will be observed that this series covers all possible permuta-tions and combinations of the three atoms : nitrogen, sulphur, andoxygen.Measurements of the reactivity of the various non-carbon atomswere made both qualitatively and quantitatively. I n the latter casethe method employed consisted in the addition of an alkyl bromideto the complex, by which means an ( ( onium " salt was formed ; andthe amount of bromine thus converted into the ionisable conditionwas estimated by titration a t fixed intervals. I n each series thecorresponding methylene compound was used as a standard ; thus,piperidine derivatives were compared with the correspondingmorpholine and thiazan compounds.It was assumed that devia-tions from the normal standard were due to the mutual influenceof the two non-carbon atoms in the 1 : 4-position with regard toeach other.cyclic compounds of the type :The chief results obtaine,d may be summarised as foCH,*CH,>y,X<C H , - c H 2in which X and Y are atoms capable of raising their vaexample, nitrogen risihg from triad to pentad), and maylows: Inency (forthereforebe supposed to have some residual affinity unsatisfied, the twoatoms X and Y do actually influence each other's reactivities.Further, if X and Y be atoms of the same element, their reactivepower is increased; whereas if X and Y are atoms of differentelements (as in the morpholines) their reactivity is diminished bythe spatial conjugation.The physical constants of the varioussubstances mentioned above have been examined, but in thisdirection the results have not been striking.These results are of considerable importance, as they establishbeyond question that two non-adj acent centres (structurally speak-ing) can influence each other's chemical reactive power to a marked37 Clarke, T., 1912, 101, 1788ORGANIC CHEMISTRY. 165degree; and i t may be anticipated that the observation that similaratoms stimulate one another whilst different elements diminish eachother’s reactivity will prove of value in further research along thesame lines, and may even provide a better knowledge of thebehaviour of such atoms when structurally conjugated.The same branch of the subject has been attacked from adifferent point of view.38 It has been shown that if the absorptionspectra of various stereoisomerides are examined, the two structur-ally identical compounds do not always exhibit identical spectra.I n those cases in which the two isomerides differ markedly fromeach other in spectra, i t was found that the change from oneisomeride to the other entailed the shifting in space with regardto one another of two centres of residual affinity; and that whenthe compounds did not fulfil this condition the difference in theirspectra was very slight, or even in some cases non-existent.Itwould therefore seem of interest if the cyclic compounds formulatedabove were investigated spectroscopically, as it appears probablethat the results might be important.The Chlorophyll Question.This subject hardly le’nds itself to annual summarisation, and infuture it would be preferable to devote a section to it at suchtimes as would enable the reporter to give a connected account ofseveral years’ work, so that the reader need not be confused withdetails carried on from year to year. I n the present section noattempt could be made to cover the whole field of work; all thatwas possible was to take up one or two points which appear likelyto have a bearing on future investigations.It may be recalled that if chlorophyll (phytyl chlorophyllide) istreated with acids, i t is decomposed into phaeophytin (phytyl phzo-phorbide); and that this substance when subjected to alkalisproduces a mixture of phytochlorine-e and phytorhodiri-y. The factthat the two latter substances are always produced in practicallyconstant quantities (1 mol.of the former to 2.5 mols. of the latter)whilst their molecular weights (after allowing for loss of phytol andmethyl alcohol) approximate t o that of chlorophyll, has suggestedthat chlorophyll may be a mixture of two substances, one of whichon degradation yields phytochlorine-e, whilst the other is a phyto-rhodin-g derivative. This view has now been shown to be correct 39by the separation of chlorophyll itself into two compounds, one ofwhich, chlorophyll-a, is bluish-green, and yields only phytochlorine-aas a degradation product, whilst the other, chlorophyll-b, is3c9 Macbeth, Stewait, niitl Wiight, T., 1012, 101, 509.39 Willstitter and lsler, Animlen, 1912, 390, 260 ; A., i, 710166 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.yellowish-green in colour, and produces only phytorhodin-g when i tis decomposed.The intermediate decomposition product of chloro-phyll, phaeophytin, has also been shown to be a mixture of twosubstances.The same process was applied a t a slightly earlier date 40 to somechlorophyll derivatives. Chlorophyll, as is known, is phytyl chloro-phyllide; and since the chief problem at issue is the constitution ofthe non-phytyl portion of the molecule, i t seemed simpler to replacethe phytyl group by ordinary alkyl radicles. I n this way methyl-chlorophyllide and its homologues are produced.These substanceshave now been shown to be mixtures of the a and b chlorophyllides,which give rise to the corresponding phaophorbides a and b .It will be remembered that in alcoholic solution chlorophyllidesand alkylchlorophyllides undergo certain changes which producesubstances different from the original one employed.41 The term“allomerism” is now applied t o such processes, and it is sug-gested that they are probably due to a rupture of the lactamgroup in the chlorophyll derivative and the subsequent formationof a new lactam form. It has been shown that allomeric changecan be catalytically accelerated by the presence of glass; it isprevented by the addition of a trace of acid, and is unaffected byeither platinumThe results offollowed on theor silver.various methods of decomposing chlorophyll can beformula below :$H-$0C0,Me*[C,lH,,N,Mg]*C~,*C20H,,Chloroph yll-a.B -( A ) If chlorophyll is submitted to the action of the enzymechlorophyllase, the a-group alone is attacked.The resulting sub-stances depend on the solvent used: in methyl or ethyl alcohol themethyl or ethyl group replaces the phytyl nucleus, whilst in aqueousacetone solution the phytyl radicle is replaced by a hydrogen atom,yielding the free chlorophyllide. ( B ) If chlorophyll is acted on byacids there occurs, as a result of gentle treatment, a displacementof magnesium by hydrogen ; and the corresponding phzeophytin isliberated.More vigorous treatment results in hydrolysis at thea-group, with the formation of free phaeophorbides. No allomerismoccurs under this treatment, showing that the original lactamgroup is unaffected. (C) The first point of attack of alkalis is they-lactam group, a new lactam group being subsequently produced.The next action is hydrolysis a t the a-group. Finally, with more40 Willstiitter and Stoll, An?taZcn, 1012, 387, 317 ; A., i, 285.dl Willstatter and Utzinger, ibid., 1911, 382, 129 ; A, 1911, i, 659167difficulty, the &group undergoes hydrolysis. At higher temperatures alkalis cause the elimination of carbon dioxide, resulting in adegradation t o phyllins and porphorins.The following diagram-matic scheme will make the results clear:ORGANIC CHEMISTRY.(4Chlorophyll-a.PC0,Me - acids -+ ~N4c3~H320]C0,C,,H,,aPhaophytin-a.Methyl chlorophyllide-a.(4 ~ Chloroph yljide-a..CO,H@)Methyl phaophorbide-a.UPhajophorbidc-a.isoChlorophyllin-e. Phy tochlorin-e.Several investigations of the absorption spectra of chlorophyllderivatives have been made during the past year,42 and the case israther an exceptional one, since it has been found that in thisseries chemical methods are more delicate than spectroscopic ones.This is probably due to the great complexity of the chlorophyllnucleus, and also to the fact that the absorption spectra were notextended far into the ultra-violet in this particular case.A considerable amount of work has been carried out on theporphorin group,43 but it does not lend itself to detailed treatmentin this place.42 Willstatter, Stoll, and Utzinger, Annulen, 1911, 385, 156 ; A., i, 40 ; Dhdrkand Rogowski, Compt.rend., 1912, 155, 653 ; A , , i, 387 ; Marchlewski, Biochein.Zeitsch., 1912, 413, 234 ; A., i, 791.43 Marchlewski and Robel, Ber., 1912, 45, 816; A, i, 376 ; Biochem. Zeitsclt.,1912, 39, 6 ; A., i, 290 ; Marchlewski and Znrkowski, Biochem. Zeitsch., 1912, 39,59 ; A . , i, 290 ; Marchlewski, An?mlen, 1912, 388, 63 ; A . , i., 238 ; Malarski andMarchlewski, Biochcm. Zcitsch., 1912, 42, 210 ; A., i, 641168 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Phyllopyrrole and Haemopyrrole.When hzmine is reduced with hydrogen iodide and phosphoniumiodide it yields among other products the substance haemopyrrole,which can also be produced as a decomposition product of chlorc+phyll.With a view to comparing the pyrrole derivatives whichform part of the nuclei of chlorophyll and hzemine, both compoundswere subjected to degradation proce~ses,~4 and it was found that thefinal hzmopyrrole produced was not a single substance, but was amixture of three pyrrole derivatives, which were named respec-tively, phyllopyrrole, hzemopyrrole,*5 and isohzemopyrrole.45 Theconclusive proof of the. constitution of these compounds by syn-thesis was not a t that time forthcoming; but in the present yeartheir structures have been placed beyond doubt. It has been shownthat when sodium methoxide or ethoxide is allowed to act onpyrrole derivatives a t high temperatures in alcoholic solution, theresult is a displacement of the hydrogen atoms of the methinegroups by methyl or ethyl radicles.By applying this process tocertain trisubstituted pyrrole compounds, the synthesis of phyllo-pyrrole has been acc~mplished.~~ The scheme below shows that theresults leave no doubt a~ to the constitution of phyllopyrrole;EMe*EHCMe CbhN H\/EMe-EEtCMe CHN H\/sMe*;CI)EtC.H CMeN H\/fiMe*EEtCMe CMe\/NHThe constitution of hEmopyrrole (Willstatter and Asahina’s iso-hzmopyrrole) has been definitely settled by a process of exclusion.47H2lemopyrrole is a trisubstituted pyrrol6, which can be convertedinto methylethylmaleimide; this proves that the ethyl group is inthe &position in the pyrrole ring.Further, when hzmopyrrole isethylated, it yields a substance which is not identical with 2 : 4di-methyl-3 : 5-diethylpyrrole ; therefore this compound obtained from44 N‘i1lst;itter and Asahina, Annalen, 1911, 385, 185 ; A., i, 41 ; H. Fischerand Bartholomaus, BcT., 1911, 44, 3313 ; A . , i, 50.45 Fischer and Bartholomaus, (Bey., 1912, 46, 1979 ; A., i, 646) propose to invertthese names, since Willstiitter’s iso-compound forms the major part of the mixture.Fischerand RartholomSus, Bcr., 1912, 45, 466 ; A . , i, 297 ; compare Colacicchi,Alti R. Accad. Lincei, 1912, [v], 21, i, 489 ; A., i, 646.Ibid., 1979 ; A., i., 646ORGANIC CHEMISTRY. 169haemopyrrole must have the two ethyl groups on the same sideof the molecule.Hence the hydrogen atom replaced in this ethyla-tion process must lie in the a-position next the ethyl radicle, whichfurnishes the following constitution for haemopyrrole :EMe*gEtCMe CLI *\/N HThis evidence is supported by the fact that a synthesis of 2 : 3-di-methyl-5-ethylpyrrole showed that this substance was different fromhaemop yrrole.A third pyrrole derivative, 2 : 4-diinethyl-3-ethylpyrrole, has beenisolated from the hzemopyrrole mixture, and to this the namecryptopyrrole has been given. Its constitution has been establishedby a comparison with the synthetic substance. The proportions inwhich these compounds occur in the volatile bases obtained fromhemine appear to be the following: phyllopyrrole, 5 per cent.;hEmopyrrole and cryptopyrrole, about 20 per cent.Piloty and Stock48 suggest that in view of the complexity ofthe haemopyrrole-phyllopyrrole mixture it would be preferable tocall all the constituents by the general name hzemopyrrole, dis-tinguishing them from each other by the suffixes -a, -6, etc., in theorder of their melting points.Thus, Willstatter and Asahina’s,isohaemopyrrole would be termed haemopyrrole-b. According toPiloty and Stock, Willstatter and Asahina’s liaeinopyrrole is amixture of two substances to which they have given the nameshaemopyrrole-b and hraemopyrrole-c according to the suggestednomenclature. There are thus four hEmopyrroles (a, b , c , and d ) ;the first of these is 3-methyl-4-ethylpyrrole ; the second is Willstatterand Asahina’s isohaemopyrrole; the third is identical with acompound, 3 : 5-dimethyl-4-ethylpyrrole9 which has been synthesisedby Knorr and Hess49; whilst the fourth is phyllopyrrole.A considerable number of other papers in this branch of thesubject have appeared.50Annulen, 1912, 392, 215 ; A ., i, 923.49 Ber., 1911, 44, 2758; A . , 1911, i, 1019.Leyko and Mnrchlewski, Bull. Acad. Sci. Cracoiu, 1911, A, 345 ; A., i, 56 :Willstatter and Asahina, Ber., 1911, M, 3707 ; A., i, 127 ; Grabowski andMarchlewski ; Bcr., 1912, 45, 453 ; A., i, 297 ; Kriorr and Hess, Ber., 1912, 45,2626 ; A., i, 900 ; Marchlewski, Zcitsch. physiol. Chem., 1912, 79, 351 ; A., i,646 ; Marchlewski and Grabowski, Zcitach.physiol. Chent., 1912, 81, 86 ; A . , i,1015170 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The Colouring Matter of the Blood.Closely connected with the chlorophyll question is the problemof the colouring matter of the blood; and as this seems to be withina few steps of its complete solution, a short summary of its laterstages may be given here.The colouring matter of the blood is composed of two portions,one of which is albuminous and is called globin, whilst the otheris non-albuminous in character, and is termed hzmatin. It iswith the latter part that we have to concern ourselves. I n thebody, it is supposed that hzmatin forms the source from whichanother substance, bilirubin, is produced; and the latter is oneof the constituents of bile.Now when hxmatin is reduced with hydriodic acid andphosphonium iodide, a series of four principal products is produced,namely, (1) a mixture of haemopyrroles, (2) xanthopyrrolecarboxylicacid, (3) phonopyrrolecarboxylic acid, and (4) haematopyrrolidinicacid.51 (See the scheme on p. 172.) Investigation of the haematinstructure on this line has been hindered by the fact that hzemato-pyrrolidinic acid is an amorphous substance which cannot becrystallised, and hence it has been impossible to make certain ofits constitution.Now, a t this point we are aided by the connexionbetween bilirubin and hzmatin. I n view of their close relationin the body,52 it seems reasonable to assume that there may be acertain relationship in structure between them53; and this idea isstrengthened by an examination of their behaviour under theaction of various reagents.When haematin is treated with acid,it yields a substance, haematoporphorin, which has the same com-position as bilirubin, namely, C16H180,Nz. When these two lattersubstances are fused with potassium hydroxide, they yield closelyanalogous products,54 of which the bilirubin derivatives are simplerthan those obtained from hamatoporphorin ; the former substancegives rise to four pyrrole compounds, whilst the latter producesonly two.Now, when bilirubin is reduced with hydriodic acid andphosphonium iodide, it yields a substance, bilic a>cid, which differsin composition from the amorphous hzematopyrrolidinic acid byonly one oxygen atom: hamatopyrrolidinic acid has the com-position C1,HZ6o2N2, whilst bilic acid is represented by C,,H2603N2.51 Piloty and Dormann, Annalen, 1912, 388, 313 ; A., i, 519.52 Kuster, Zeitsch,physiol.Chem., 1909, 59, 63 ; A., 1909, i, 319.53 It must be noted, however, that this is only an assumption, as in many casesone compound is transformed into another in the body by a series of dccompositiollsand syntheses which leave very little of thc original structure in existence.b4 Piloty and Thannhauser, Annnlcn, 1912, 390, 191 ; A . , i, 736ORGANIC CHEMISTRY. 171The chief point of practical interest, however, is that bilk acid is asubstance of a crystalline character in contradistinction from theamorphous analogue. An investigation of the properties of bilicacid is therefore much more certain of results than an examinationof the other compound.Let us now compare the effects of various reagents on these twosubstances.Both dissolve in warm water, giving a foamy liquid;neither crystallises out on cooling; but both may be salted outwith sodium chloride. Both have the faculty of holding pyrrolederivatives in loose combination (adsorption) ; and both giveamorphous metallic salts or picrates. When they are fused withpotassium hydroxide, both give similar decomposition products,although in the case of bilk acid no hxmopyrrole is obtained., Onoxidation with chromic and sulphuric acids, both produce hamaticacid and methylethylmaleinimide.The main difference between the two compounds, then, is thatIizematopyrrolidinic acid has one oxygen atom less than bilic acid;whilst bilk acid on fusion produces no hzemopyrrole fission productslike those obtained from hEmatopyrrolidinic acid.Piloty and Thannhauser 55 suggest that the following formula (I)is the most probable one to express the behaviour of bilic acid;whilst (11) would satisfy the necessities in the case of haernato-pyrrolidinic acid :IH,*CO,HCH NHQH,*CO,HCH NH/\/\ /\/\ CH,*S-QH C;H EaCH2*OHCH,*C CH CH-C*CH,*CH, CH,*C CH CH-C*CH,*CH,CH,=E-YH QH fi*CH,\/\/NH CH,\/\/NH CH,56(I.) Elic acid.(11.) Haematopyrrolidinic acid.The production of haematic acid (111) and methylethylmaleinimide(IV) from both (I) and (11) can be realised by an inspection ofthe formuh; and it will be observed that the presence of the thirdoxygen atom in bilic acid in the centxe of an alcoholic radiclewould sufficiently explain the lack of hzemopyrroles in the fissionCH,*CO,H\/NHNHA70 yoCH,*C==C*CH,*CH, - -(111.) Hzmatic acid.(IV.) Methylcthylmaleinimide.59 A ~ ~ n c c Z c ~ ~ , 1912, 390, 191 ; A . , i, 736.56 It seems possible that this group and the cthyl radicle should be interchanged172 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.products of the former substance under the somewhat trying con-ditions of an alkali fusion.Let us now turn back once more to hzmatin. On treatmentwith acids, this substance undergoes a change in the course ofwhich it loses its iron content and is converted into haema5o-porphorin; and on reducing this last substance we get a mixtureof haemopyrroles, some haematopyrrolidinic acid, phonopyrrole-carboxylic acid, and xanthopyrrolecarboxylic acid.When treatedby similar methods, bilirubin produces, among other substances,isoplionopyrrolecarboxylic acid, which is isomeric with phono-pyrrolecarboxylic acid.Xaiithopyrrolecarboxylic acid 57 has been shown to have(probably) the structure I ; and since isophonopyrrolecarboxylicacid and xanthopyrrolecarboxylic acid on treatment with nitrousacid both yield the same semi-oxime,58 it appears that isophono-pyrrolecarboxylic acid may be the homologue (11). Phonopyrrole-carboxylic acid probably has the structure represented by I11 :8 H C*CII,*CH, C H C-CH,CH 3* C---g C€T2*CH2*C0, H CH3*fi-$CH2*CH2*C02H\/NH\/NTI(I.) Xanthopyrrolecarboxylic (11.) isoPhonopyrrolecarboxylicacid. acid.C H,* fi--R CH, * CH2*C0,HCH;C CH' \/NH(111.) Plionopyrrolecarboxylic acid.The following scheme shows some of the chief relationshipsbetween the principal compounds in this group :Hzemine4H.1in organism acidBilirubin +- Hamatine -+ Hzmatoporphorin I reduction I recluction I reductionI + 4, .c. \y J. 4,isoPhono- Bilic acid Hsmatopyrrol- Phono- Xantho- Hzmo-pyrrol ecarb- idinecarb- pyrrolccarb- pyrrolecarb- pyrroleoxylic acid oxylic acid oxylic acid oxylic acid mixtureHaematic acid andinethylethylmal einimide.57 Piloty and Dormann, Annalcn, 1912, 388, 313 ; A., i, 519.Piloty and T!iannhanser, ibid., 1912, 390, 191 ; A., i, 736ORGANIC CHEMISTRY.173Complex Salts.I n recent years a considerable amount of attention has beendirected to the question of complex salts, and a short section onthis subject may not be misplaced in the present report, tcsapparently such compounds should be regarded as coming withinthe group of heterocyclic substances. It is well known that thecopper salt of glycine possesses a brilliant blue tint, even moremarked than the ordinary copper salts’ colour, and seeming moreakin to the blue solution obtained by dissolving a copper salt inexcess of ammonia. Now, copper acetate has been found capableof adding on two molecules of ammonia to form a deep bluecompound, the colour of which resembles that of the glycine coppersalt, and the assumption is currently made that these two moleculesof ammonia are directly attached to the copper atom by “ auxiliaryvalencies” so that the formula of the compound may be writtenas in (I) i f we designate the auxiliary valencies by dotted lines.On a similar assumption, the formula for the copper salt of glycinewould be written as in (11).NH,*CH, CO* 0 NHs CH,*CO*O/“’ \‘‘8>cuNI13 /‘ CHs-CO*O \ NH,*CH,*CO-0(1) (11)During the current year, a coiisiderable amount of work69 hasbeen done in this section of the field.An important class ofcompounds which has been fully studied in this connexion includesthose which give the biuret reaction. The peculiar tint obtainedwhen substances respond to this reaction is now ascribed to theformation of a complex copper or nickel salt; and the structuralconditions necessary to the production of such a salt have beenvery fully dealt with by Kober and Sugiura.60 It was found thatthe colour produced in the biuret reaction depends on the con-stitution of the complex salt formed ; substances containing oriecopper and two nitrogen atoms give a deep blue tint; those con-taining one copper and three nitrogen atoms show a semi-biuretcolour of varying shade; substances which contain one copper andfour nitrogen atoms give a red tinge.Thus, the dipeptides and59 Weinland and Biittner, Zeilsch. nnorg. Chem., 1912, 75, 233; A., i, 530 ;Costiichescu, Ann. Sci. Univ. Jassy, 1912, 7, 87; A . , i, 493; Costiichescu midSpacu, ibid., 132 ; A,, i, 494 ; Ley and Ficken, Ber., 1912, 45, 377 ; A., i, 243 ;Ley and Winkler, ibid., 372 ; A., i, 243.Bo J.Bwl. Chem., 1912, 13, 1 ; Amr. Cham. J., 1912, 48, 383 ; A , , i, 952, 9531'74 ANNUAL REPORTS ON THE PROGRESS OF. CHEMISTRY.their carboxyl derivatives give a tint like glycine; tripeptides andtheir carboxyl derivatives (excluding their amides), and the amidesof dipeptides give a semi-biuret tinge; whilst tetrapeptides and theamides of tripeptides give a purple-red colour in the biuret reaction.The further spectroscopic investigations in this direction will beof great interest when they are completed.Miscellaneous.In the following paragraphs a few points will: be consideredwhich, although of interest, do not lend themselves to the moreextended treatment which has been dealt out to the other subjectsin this section of the report.A new method of obtaining thiophen6l has been devised whichappears to give very good results.Acetylene is passed through aniron tube charged with pyrites, and so arranged that the usedpyrites can be removed. The tube is heated to 300° while tilegas is passed. On condensing the products, it is found that theyield contains 40 per cent. of thiophen; and on purification thesubstance can be obtained with a purity of 95 t o 96 per cent.Compared with the usual methods, this new one seems to beeminently satisfactory especially from the point of view of cheapness.A somewhat peculiar reaction between acetic anhydride anda-picoline has been described,62 which may be expressed by thefollowing equation :C,H,N + 2(C'H3*CO),0 = Cl2HIlO2N + CH3*C02H + 2H20.The nitrogen derivative thus obtained has no basic properties,reacts with hydroxylamine, phenylhydrazine, and semicarbazide,and condenses with two molecules of aromatic aldehydes, theproducts giving intensely coloured compounds with sulphuric acid.From the reaction with hydroxylamine, it is clear that the twooxygen atoms are true carbonyl oxygens, and are not acyl oxygens.When the substance is boiled with sulphuric or hydrochloric acid,it yields a base isomeric with indole, which, when reduced, takesup two atoms of hydrogen.The following names and formulz aresuggested for these compounds :CH CH\/ \\CH CH2Picolide. Pyrrocoline.a-Butaciienylpyrrole.61 W. Steinkopf, Yerh. Ges. deut. Natn~rforsch. Aerztc, 1912, ii, [I], 220 ; A . , i,292.62 Scholtz, Ber., 1912, 45, 734 ; A., i, 385ORGANIC CHEMISTRY. 175In the pyrazoline group, some investigations 63 have been begunwith the view of obtaining derivatives of cyclopropane by thedecomposition o,f pyrazoline compounds.Azodicarboxylimide derivatives 64 of the formula (11), in which(1.1 (11.1R is H, Ph, NH, or N:CHPh, have been prepared by the actionof an ethereal solution of iodine on the silver salts of the corre-sponding hydrazo-compounds of the formula (I). They are foundt o be decomposed by water in accordance with the equation:2fJ'co>N*R + 2H,O = N, + 2C0, + NH,*R -t $E:EE>NH. x-coA continuation of the investigation of the endoazo-compoundsdeserves notice, as the compounds described belong to the class ofspiranes in which interest is being taken a t the present time.Some glyoxaline derivatives 66 allied to the alkaloid pilocarpinehave been prepared, and their physiological effects have beentested.Mention must also be made of the very extensive investigationsof the pyrimidines 67 and hydantoins 68 which have been publishedduring the year.Molecular Asymmetry.Pope2 hasrestated his views more explicitly this yeas, and gives the followingdefinition, which seems to make his point of view clearer thanbefore." Every molecular configuration is enantiomorphous, andpresumably capable of exhibiting optical activity, which contams nocentre of symmetry ; and, conversely, every molecular configurationis potentially optically inactive which contains a centre of sym-This subject was dealt with in last year's report.'Kijner, J.Russ. Phys. Chem. SOC., 1912, 44, 165; A., i, 245.StollB, Ber., 1912, 46, 273; A., i, 225.65 DUVSI, Compt. rend., 1912, 154, 780; A., i, 398.66 Pyman, T., 1912, 101, 530.67 Johnson and Shepard, Amer. Chesn. J., 1912, 48, 279 ; A., i, 910 ; Johnsonand Hill, ibid., 296 ; A . , i, 912 ; Johnson and Moraii, ibid., 307 ; A., i, 913.68 Johnson and Hoffman, Amer., Chem, J., 1912, 47, 20; A . , i, 136;Johnson and Guest, ibid., 103, 242 ; A., i, 316, 807 ; Johnson and Nicolet, ibid.,459 ; A.. i, 585 ; Johnson and Ambler, ibid., 197 ; A., i, 799 ; Johnson, J. Biol.Chem., 1912, 11, 97 ; A., i, 390 ; Johnson and Brautlecht, ibid., 175 ; A., i.805 ;Johnsou and O'Brien, ibid., 205 ; A., i, 806 ; Johnson, Pfau and Hodge, J, Amer.Chem. Sos., 1912, 34, 1041 ; A . , i, 807 ; Johnson and Nicolet, ibid., 1048 ; A., i,808 ; Johnson and Bengis, ibid., 1054, 1061 ; A.: i, 808, 809 ; Johnson andChernoff, ibid., 1208 ; A., i, 810.Pope and Read, T., 1912, 101, 2325. A m . lieport, 1911, 71176 AKNUAL REPORTS ON THE PROGRESS OF CHEMISTRYmetry.” The confusion appears to have arisen owing to the useof the expression ‘( asymmetric atom ” in a sense different from thatin which this is usually employed. Pope’s view is that in anenantiomorphous molecular configuration every atom present isasymmetric, in the sense that it is devoid of geometrical associationwith a centre of asymmetry.In this connexion, attention may be drawn to the case of sub-stances having the general formula :Such substances exist in cis- and trans-forms, and the trans-isomeride(internally compensated) possesses no element of symmetry otherthan a centre of symmetry, whilst the cis-forms (optically active)have no cegtre of symmetry, but possess a two-fold axis of sym-metry. The case of the cis-1 : 4-diketo-2 : 5-dimethylpiperazines 3furnishes the only example of this type which has been successfullyexamined up to the present.The same kind of asymmetry exists inthe u- and p-2 : 5-dimethylpiperazines 4 which have recently beenexamined. Unfortunately, positive results were not obtained in thiscase; but the results of further experiments now in progress mayincrease our knowledge of this interesting class of isomerides.A New Method of Resolving Inactive Mixtu-res into theA ntipdes.A few years ago6 i t was found that d-oxymethylenecamphorcould be used as a reagent for determining whether a primary orsecondary arnine is externally or internally compensated.Oxy-methylenecamphor in the enolic form has the structure representedby (I), and when it is allowed to condense with secondary aminesit yields condensation products of the formula (11) :(1.1 . (11.)If the amine is internally compensated it yields only one productwith d-oxymethylenecamphor ; but two condensation products areformed by an externally compensated amine, and these can beseparated by fractional crystallisation.I n this way it is possibleto ascertain whether the m i n e is potentially optically active ornot; but the drawback t o the method has hitherto been that theamine’s two antipodic forms could not thus be obtained, as no3 Fischer, Ber., 1905, 39, 453; A., 1906, i, 145 ; Fischer and Raske,Silzungsber. R. Akad. Wiss. Berlin, 1906, 371 ; A . , 1906, i, 457 ; Ber., 1906, 39,3981 ; A., 1907, i, 18.Pope and Read, Eoc. cit. Ibid., T., 1909, 95, 171ORGANIC CHEMISTRY. 17’7method had been devised for splitting up the condensation productso as to liberate the amine portion. This defect has now beenremedied,G for it has been shown that by acting on the condensationwith bromine in carbon tetrachloride solution the hydrobromideof the base is obtainable.A syinrrie t ric Synthesis.A considerable advance in the study of this subject has beenmade by the discovery7 that an asymmetric synthesis can bebrought about by the use of an optically active catalyst, Whenbenzaldehyde and potassium cyanide are allowed to interact insolution, they yield racemic niandelonitrile ; but if benzaldehyde iscondensed with hydrocyanic acid in the presence of an opticallyactive alkaloid, the resulting mandelonitrile is found to be opticallyactive. The rotatory power of the product depends on the alkaloidemployed ; quinone produces a mandelonitrile which yields onhydrolysis Z-mandelic acid, whereas quinidine f avours the formationof d-mandelic acid.There appears to be no doubt that the alkaloidemployed enters into combination with the cyanohydrins ; and italso seems to be proved that the action of the alkaloids is a catalyticone, for the molar amounts of them necessary to produce thereactions are less than those of the products.Ra c e mism .Very little work has been done in this division of the subjectduring the year.Jerusalem 8 has examined the crystallography ofvarious active substances and the corresponding racemic forms, andfinds that a close morphotropic relationship exists between them.Such a relationship follows from Barlow and Pope’s theory, whichthus receives further support.The question of the existence of liquid racemates has been dealtwith in the case of fused methyl racemate.9 This work, which isbased on the application of measurements of the velocity of crystal-lisation, the temperaturecoefficient of the molecular surf ace energy,and the molecular heat of vaporisation, tends to prove that thefused substance is a mere mixture of the two antipodes, and not atrue racemic compound.The mechanism of the process of racemisation by heating hasbeen examined,lo and in the case of malic acid it has been shownli Pope and Read, T., 1912, 101, 2325.7 Bredig and Fiske, Biochem.Zeitsch., 1912, 46, 7 ; A., i, 983. * T., 1912, 101, 1268.lo James and Jones, T., 1912, 101, 1158.Gr6h, Ber., 1912, 45, 1441 ; A., i, 411.REP.-VOL. IX. 178 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.that fumaric acid is produced as an intermediate stage in thereaction. I n the case of the racemisation of tartaric acid, consider-able quantities of pyruvic acid were formed, and it is concludedthat the following reversible reactions play a part in themechanism :CO,H*$!H* OH - CO,H*E*OHCH(OH)*CO,H - CH*CO,HCO,H* 70CH,* C0,HThe Walden Inversion.With the present year this problem appears to have entered anew stage.The full summary which was given in last year’sreport 11 renders it unnecessary to enter into much detail here; buta single example may be given to make the matter clear. Ifd-alanine is treated with nitrosyl bromide the main reaction productis Z-a-bromopropionic acid, whereas if the d-alanine is esterified, theester treated with nitrosyl bromide, and then hydrolysed, there isobtained cE-a-bromopropioric acid ; thus in each case the startingpoint is the same dextro-acid, but in one instance the final productis dextrorotatory, whilst in the other it is the optical antipode; andtherefore a t some point or other in the series of reactions there musthave been a rearrangement of the groups around the asymmetriccarbon atom.Hitherto, those investigators who have touched on the problemhave confined their attention to this actual shifting of the groupsin space, and have brought forward the views which were summar-ised last year.Now, however, it is beginning to be realised thatthere is another side to the question, namely, the actual mechanismof the reaction, apart from any spatial considerations. It will bewell to take up these two points in the above order.Biilmann 12 has examined the explanations put forward byFischer13 and by Werner>* and he considers that although a t firstsight they appear to amount to the same thing, yet on closer exam-ination they are fundamentally different.I n the first place, takingas his example the action of ammonia on a-bromopropionic acid,Fischer assumes that the ammonia molecule which reacts with thebromo-acid is dissociated into hydrogen and the amino-group; butBiilmann, basing his conclusions on the similarity of the actionsof primary, secondary, and tertiary amines on bromo-compounds,regards this assumption as too great to be easily conceded, since,l1 Ann. Report, 1911, 60.l3 Ibid., 1911, 381, 123 ; A . , 1911, i, 418.l4 Ber., 1911, 44, 881 ; A , , 1911, i, 424.l2 Annnlen, 1912, 388, 330; A., i, 420ORGANIC CHEMISTRY. 179according to him, i t would entail the acceptance of the idea thattertiary amines also decomposed during such reactions.16 Therefore,on his view, i t is impossible to admit Fischer’s contention that theamino-group simply takes the place left vacant by the ionisedbromine atom.Secondly, to explain the optical inversion whichtakes place in the Walden change, Fischer assumes that in suchcases the following phenomena occur: the bromine atom firstbecomes ionised, and is removed from the complex; then one of theremaining three groups attached to the asymmetric carbon atammoves into the place of the bromine atom; and, finally, the amino-radicle takes up t b position left free by the shift of this group.As Biilmarin points out, this forms a possible explanation of howthe inversion occurs, but it merely carries us a step back, and leavesus still to discover why the groups should interchange their posi-tions.I n most cases it seems probable that, during the shifting ofthe groups from one position to another, racemisation would takeplace to an extent much greater than is observed in practice. Thesedifficulties might be overcome If it were assumed that the ammoniamolecule takes up a definite position sterically with regard to theother atoms concerned in the reaction; but in his paper Fischerexpressly stated that he only assumed the attachment of the amino-group to the carbon atom by residual affinity “on the grounds ofsimplicity,” and that such an attachment formed no part of theessentials of his hypothesis.16Now, according to Biilmann, Werner’s hypothesis differs fromFischer’s a t this critical point.Let us take a concrete ex-ample for the sake of clearness, namely, the action ofhydrochloric acid on a substance of the formula (I), producingAB > e H B(1.1 (11.1a substance with the formula (11). Such a change could be,assumed t o occur in either of two ways, according as the hydro-gen chloride molecule attaches itself to one side or other of theplane through ABD. If it attaches itself on the same side as thehydroxyl group, then, after water has been eliminated, the chlorineatom will occupy the same position it9 that of the original hydroxyl;if, on the other hand, the hydrogen chloride molecule attachesitself to the molecule on the side opposite to the hydroxyl, then 6hel5 Mr.P. J. Brannigan has pointed out to me that a similar dissociation of theammonia molecule is implicitly assumed in such reactions as amide formation andtlie production of aldehyde-ammonia ; which seems to destroy the force of this partof Biilmsnn’s argument.-A. W. S.l8 Fischer (Annnlen, 1912, 386, i, 187) has stated that hi3 paper was written’‘ critically ’’ rather than as a constructive explanation.N 180 ANNUAL REPORTS ON THE PROURESS OF CHEMISTRY.elimination of water will produce the mirror-image of the otherchloro-derivative, and we shall have an example of Walden’s inver-sion.Now Werner assumes this attachment of the hydrogenchloride molecule as part of his explanation; and if this be granted,it is clear that the deciding factor in the question will be theattractive forces exerted on the hydrogen chloride molecule by thevarious atoms which make up the compound ABCD-OR. Theassumption of the existence of such forces is one which we caneasily make, and from that the whole explanation of the Waldeninversion follows naturally. I f the attractive forces in questiontend to bring the hydrogen chloride molecule and hydroxyl groupto the same side of the plane ABD, then no inversion takes place;but if the tendency of these forces is to attract the hydrochloricacid to the opposite side of the optically active molecule the Waldenchange occurs.Biilmann further suggests that racemisation might be consideredas another case of intramolecular change analogous to the Waldeninversion, in view of the influence which hydroxyl ions are knownto exert on the former process.This suggestion, however, shouldbe judged in connexion with the results of James and Jones in theracemisation of tartaric acid.“He assumes thatin such reactions as the Walden inversion an additive compoundis prirr?arily produced, which is formed by the new group attachingitself to the halogen atom instead of to the asymmetric carbonatom. When the inversion takes place in the compound CabcC1,the halogen atom is supposed to be removed from the carbon,leaving three groups behind.These then vibrate in such a wayas to distribute themselves evenly about the carbon atom; but inthe course of their movement they overshoot the equilibrium point,and thus pass into a position which is the mirror-image of the onepreviously occupied. The hydroxyl group then attaches itself tothe carbon atom, and thus the inversion is accomplished. Gadamarassumes that the differing behaviour of the metallic hydroxides canbest be explained by supposing that the normal hydrolysis is due tothe action of the anion of the hydroxide, whilst abnormal resultsare due to the action of the cation. I f this hypothesis were correct,it seems probable that the temperature of the reaction mixturewould have a considerable influence on the amount of “overshootring” of the equilibrium position, and investigations in this direc-tion would be of interest.Turning now to the second problem, namely, the actualFinally Gadamar’s views may be mentioned.18See p.177. l8 Chern. Zeit., 1912, 36, 1327 ; A., i, 934ORGANIC CHEMISTRY. 181mechanism of the reactions involved in the Walden inversion, wemay begin by a summary of Biilmann's views. It is quite clearthat in the case of the reactions of the bromo-substituted acids thereare two possibilities : for if a given reagent reacts direct with thebromine atom, then we should expect a case of simple substitution;whereas if this is not the case, then we may have to deal with anintramolecular rearrangement in the course of the reaction. Let usexamine from this point of view the case of the reactions of thehalogen-substituted acids.Walden found that when 2-chlorosuccinicacid is treated with potassium hydroxide, d-malic acid is formed;whereas when silver oxide is substituted for the alkali, Z-malic acidis the principal product of the reaction. Now a t first sight thisappears strange, but a closer examination of the actual experimentalconditions helps to clear up the difficulty. I n most cases it appearsthat the reaction is not one between the halogen-substituted acidand silver oxide, but rather a mere decomposition of the silver salt;for instance, in the conversion of Z-a-bromopropionic acid intoZ-lactic acid by this method, Fischer,lg working a t the ordinarytemperature, shook together an aqueous solution of the acid andsilver carbonate.The result of this, of course, would be the forma-tion of the silver salt of Z-a-bromopropionic acid, and since thissubstance itself in aqueous solution rapidly eliminates silverbromide, Biilmann doubts whether the excess of silver carbonatehas any effect a t all beyond neutralising the lactic acid which isformed as a final product; thus in this case we are not dealing witha simple interaction between silver oxide and the bromine ion ofthe acid (since the solution must be saturated with carbonic acidduring the course of the reaction), and hence the case is not at allparallel to the interaction between the bromo-acid and potassiumhydroxide.On the basis of Senter's20 investigations of the hydrolysis ofhalogen-substituted acids, Biilmann considers that, in the first place,the bromo-substituted acids ionise, and that in consequence of thenegative charge on the acid ion the bromine atom becomes lessfirmly attached, and therefore more ready to react with the silverions in the solution.The results of this series of changes may beexpressed thus :7% Q"BvHBr+Ag+ = 7"' +AgBr.(20,- c0,-I9 BET., 1907, 40, 503 ; A., 1907, i, 192.20 T., 1907, 91, 460 ; 1909, 95, 1827 ; 1910, 97, 346 ; 1911, 99, 96 ; Zeilsch.physikal. Chem., 1910, 70, 511 ; A., 1910, ii, 276182 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.This “Zwitterion ” then unites with a negative hydroxyl ion ofwater, forming an ion of lactic acid:7 4 7%GO,- c0,-FH’ +OH- = $!H*OH.Since we are dealing with ionic reactions throughout this processi t is fair t o assume that no change of relative position takes placein the groups around the asymmetric carbon, and hence no Waldeninversion is observed.Similar arguments apply in the case of theaction of nitrous acid on amino-acids, for i t is known from analogyt o the diazo-compounds that the nitrous acid first attaches itselfto the nitrogen atom of the amino-group; so that in this case alsowe should expect to find simple substitution taking place withoutintramolecular rearrangement.Another view of the interaction between bromo-substituted acidsand alkali has been put forward by HoImberg.21 From a study ofthe change in rotatory power, rate of elimination of bromine, andneutralisation with sodium carbonate in the case of I-bromosuccinicacid, he deduces that the following process occurs.The Z-bromo-succinic ion breaks down rapidly into a bromine ion and an ion ofpropiolactonecarboxylic acid which is dextrorotatory. In neutralsolution this lactone is only slowly hydrolysed; but as more andmore malic acid is formed the hydrogen ion of this catalyticallyaccelerates the process of hydrolysis; whilst at the same time itretards the rate of lactone formation. On these assumptions theprocess of the Walden inversion would be represented thus :KOH I-bromosuccinic acid -+ d-malic acid lactone -+ d-malic acid.Senter 22 points out that Holmberg’s experimental data are con-fined to one dilution, and from his own results obtained a t anearlier period he throws further light on the question.A solutionof sodium bromoacetate was titrated a t fixed intervals with sodiumhydroxide and silver nitrate. In one case the acetate solution was,../lo, in another it was 2N in strength. The results show thatin the dilute solution iihe rates of formation of the bromine ionand the hydroxy-acid approximate closely to each other, and thereaction is one of the first order; but in the concentrated solutionthe velocity of bromine ion formation greatly exceeds that of acidformation, and the reaction in its first stages deviates more andmore from the first order. Senter concludes that these results canbest be interpreted by assuming that the mechanism of the reactioncan be expressed by the following equations:?l BLT., 1912, 45, 1713, 2997; A , , i, 603, 943.a fix, 2318 A ., i, 828ORGANIC CHEMISTRY. 183I.11. {There is also a possibility of a third reaction leading to theformation of acetoxyacetic acid. In dilute solution, Sentersupposes that the reaction is practically that which is representedby equation I, whilst in solutions of higher concentration the secondreaction comes more and more into prominence. Senter considersthat there is no evidence against the lactone formation assumed byHolmberg, t u t a t the same time points out that he himself, inapplying this very idea in his previous work, had assumed that suchinterzediate products would be very rapidly hydrolysed, and thatthere seems to be no reason for accepting the hypothesis that theywould bo very slowly decomposed under the given experimentalconditions.CH,Br*CO,Na + -0 = CH,(OH)*C02H + NaBr.CH2Br*C0,Na + CH,Br*CO,Na=CH,(O*CO*CTI,Br)*CO,Ne+ H20 =C!H,(O CO*@H,Br)*CO,Na + NaBr.CE&(OH)*CO,E + CH,Br*CO,Na.The Factors Znfluencing Optical Rotatory Power.This field still attracts numerous investigators, and the data,accumulated during the year testify to their unwearying industry.The subject, however, is complicated by so many obscure factorsthat it seems probable that a very long time will elapse before weare in a position to draw more than the most sketchy generalisationson the question of optical rotatory power regarded from the numeri-cal point of view.Those interested in the development of thequestion will find a very complete summary of its more importantbranches in the Presidential Address.*The work of the year has centred round the three main factorsin the problem, namely, the effects of temperature, solvent andconstitution, and the facts ascertained are very numerous.We mustcontent ourselves with the briefest survey of the more interestingpoints. Taking the effect of temperature first, Pickard andKenyon 24 have made a very exhaustive examination of the rotatorypower in a series of optically active carbinols having the generalformula R*CH( OH) *CH( @Ha),, where R represents methyl, ethyl,etc., up to n-decyl. The investigation hm been carried out ov0r awide range of temperature, extending a t times up to 200°, and allexcept where experimental difficulties intervened, the rotationa t the boiling point of the substances has been obtained, extrapolationbeing resorted t o in a few instances.I n the foregoing series it wasfound that the specific rotatory powers a t 20° increase as the seriesis ascended until a maximum is reached with isopropyl-lzrbutyl-23 Frankland, T., 1912,iOl, 658. Ibid., 620184 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.carbinol, after which the values decrease regularly to isopropyl-n-decylcarbinol. If we compare the values a t the boiling point,however, we find that the members of the series from n-butyl ton-decyl have a constant value of [MI, + 2 9 O (approximately); thusthe values rise regularly until R is of greater mass than theisopropyl group in R*CH(OH)*CH(CH,),, and then become practi-cally stationary.I n the course of an examination of various esters of di-trichloro-acetyltartaric acid the occurrence of a minimum 25 in the rotation-temperature curves has been observed.The influence of the solvent on the rotation of ethyl tartrate hasbeen examined,26 and certain relationships between the constitutionof the solvent and its action on the rot.atory power have beendeduced; but to enter into these in detail would occupy too muchspace. The dependence of molecular rotatory power on the concen-tration of solutions of salts of d-camphor-j3-sulphonic acid has beenstudied,27 and it was found that the changes observed cannot be theresult of the alteration of degree of electrolytic dissociation, butdepend principally on the character of the metallic atom or electro-positive grouping involved.Similar effects are produced bymembers of the same group in the periodic classification. Theatomic weight does not appear to be an important factor.In the Presidential Address,28 Frankland drew attention to apossible cause of anomalies in rotatory power in homologous series.Since on the van't Hoff theory of the asymmetric carbon atom theends of a straight carbon chain tend to approach one another whenthe chain contains five or six carbon atoms, it seems probable thatsuch a state of things might affect optical rotatory power in someway, such as producing a maximum rotation when this criticallength of chain was reached in a homologous series.Franklandquotes data which support his view, and the somewhat analogousresults of Hilditch 29 reinforce his argument. Pickard andKenyon,30 however, state that the rotatory powers in the seriesexamined by them do not agree with this conception; but as theproblem is certain to be complicated to some extent by any branch-ing in the chain, it seems best to regard the point as sub @diceuntil more data are obtained which are free from complication.I n some of his previous work Hilditch31 had established theimportance of unsaturated groups as influences on optical rotatory25 Patterson and Davidson, T., 1912, 101, 374.26 Patterson and Stevenson, d i d . , 241.28 T. ,1912, 101, 658 ; compare ibid., 1899, 75, 368.29 Ibid., 1909, 95, 1581.30 Ibid., 1912, 101, 1428.31 Ibid., 1909, 95, 331, 1570, 1678; 1910, 97, 1091; 1911, 99, 224.27 Graham, zhid., 746ORGANIC CHEMISTRY.185power, and from this he has been led to inquire whether unsatura-tion may not be a factor in producing the irregularities in rotatorypower which are sometimes observed among the lower members ofseries the higher members of which do not deviate to any markedextent from a constant rotatory power. The results obtained byHilditch and Christopher appear t o confirm this view. They haveexamined a series of menthyl esters of the a-bromo-aliphatic acids(in which the bromine atom is regarded as a centre of residualaffinity), and they find that menthyl bromoacetate and menthyla-bromopropionate possess rotatory powers markedly above thenormal; the anomaly rapidly declines in the next members to aminimum, slightly sub-normal value; thereafter it rises to anapproximately constant value when menthyl a-bromomyristate anda-bromopalmitate are reached.These investigations show that thereare still other factors to be taken into account before one can arrivea t any broad generalisation on the question of rotatory power andits connexion with chemical constitution ; and it appears improb-able that much progress will be made until an enormous mass ofdata has been accumulated. When this point is eventually reached,it seems evident that only a very clear thinker will be able topenetrate the maze of material a t his command.The Entropy Principle in, Organic C'hernistry.Michael33 has endeavoured to throw light on some of the moreobscure points of stereochemistry by an application to them of theprinciple of entropy. His views may be very briefly summarisedas follows: The factors which play a part in chemical reactionsare : (1) the bound chemical energy of atoms already united, and(2) the free chemical energy which remains over after the unionhas taken place.Free chemical energy may be converted intobound chemical energy either by the direct union of atoms or bywhat is nowadays termed space-conjugation, that is, the influenceon one another of atoms not directly united together in a chain.Now the conversion of free chemical energy into bound chemicalenergy is accompanied by a loss of energy in the form of heat, etc.,so it is clear that when a compound has settled into its most stablechemical and spatial state the entropy will be at a maximum.Letus apply this to the question of stereoisomerides. It will be remem-bered that in cltses like the tartaric acids van't Hoff in his theoryof the asymmetric carbon atom postulated that the two centralcarbon atoms were free to rotate about their common axis, and, inorder to avoid the deduction that in this way an innumerable3J T., 1912, 101, 192 ; Hilditch and Christopher, ibid., 202.33 Annulin, 1912, 390, 30 ; A., i, 631186 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.series of isomeric tartaric acids might be capable of existence accord-ing to the relative positions in which the two groups-CH(OH)=CO,H stood, he was forced to make the further assump-tion that the various forces of attraction between the differentatoms in the molecule tended to come into equilibrium in one parti-,cular favoured position.Now if we assume that the free chemicalenergy remaining in the groups *OH, *CO,H, and H can equateitself through space, then some energy will be liberated in theform of heat, etc., a t the time when the atoms pass into theposition most favourable to this change. After this there may beslight oscillatory movement in the molecule, but free rotation of thecarbon atoms will be impossible until heat is supplied t o the systemin quantities sufficient to reconvert the bound chemical energythus lost into free chemical energy.It is evident that this viewis perfectly general, and can be applied also to the case of geometri-cal isomerides of the ethylene type as well as to saturated com-pounds. Take the case of succinic acid and the corresponding un-saturated substances as an example. I n succinic acid itself, accord-ing to Michael’s view, the chemical resistance to rotation is small,and hence the cis-form passes into the stable trans-form with amarked increase in entropy. Now if two hydrogen atoms areremoved from the cis-configuration of succinic acid (one from eachmethylene group) there is an increase in the bound chemicalenergy between the two central carbon atoms and also between theremaining hydrogen atoms and carboxyl groups. I n this way thechemical hindrance to rotation is increased, which accounts for thegreater stability of maleic acid as compared with the cis-form ofsuccinic acid, and gives an explanation of the actual occurrence ofmaleic acid. Further, since the cpnversion of maleic acid intofumaric acid is accompanied by an increase of entropy, the freechemical energy of maleic acid will tend to bring about this con-version.With the aid of external energy supplied as heat, thistransmutation becomes possible.The catalytic action of hydrochloric acid on the maleic-fumarictransmutation is figured by Michael as follows: In the first place,a ‘‘ polymolecule ” of maleic acid and hyd.rochloric acid is formed.This contains more free energy than maleic acid alone, and conse-quently it is converted into the corresponding fumaroid “ poly-molecule.” Then, since hydrochloric acid has a greater affinity formaleic than for fumaric acid, the fumaroid ‘‘ polymolecule ” reactswith maleic acid, giving fumaric acid and a fresh maleic-hydro-chloric acid “ polymolecule,” so that the process continues until allthe maleic acid has been converted into fumaric acidORGANIC CHEMISTRY.187The Properties and Reactions of cis-trans-Stereoisomerides.A portion of the Presidential Address of this year 34 was devotedto a consideration of the problems involved in the additionreactions of ethylenic stereoisomerides. It is a well-known factthat in many cmes where we should expect to find two bromineatoms attaching themselves to a double or triple bond on the sameside of the molecule, we actually get in practice a trans-addition,that is, one bromine atom is attached to one side of t3he molecule,whilst the second atom becomes fixed t o tho opposite side; thus,for example, the action of bromine on maleic acid produces iso-dibromosuccinic acid, which has now conclusively been shown tobe the racemic form 35; whereas, if cis-addition took place we shouldexpect to find the internally compensated isomeride produced.Frankland has discussed the various cases which have arisen, andcriticises Pfeiffer’s hypothesis 36 to account for the phenomena. (Inthis connexion i t may be pointed out that van’t Hoff 37 had alreadybrought grave objections against Pfeiffer’s ideas.) Frankland’sown explanation of the matter is so simple that one can onlywonder why i t was not put forward a t an earlier period.If we aredealing with the relations of atoms in space, it seems inconsistentnot to carry the deductions out thoroughly, and Frankland there-fore takes into consideration the steric relations of the brominemolecule as well as those of the ethylenic or acetylenic compoundunder discussion. I f we assume that in the bromine molecule thetwo atoms are separated by a distance which is sufficient to bringthem to opposite sides of, say, a maleic acid molecule, then trans-addition is obviously the most probable process, since steric con-siderations would be against their coming into a position suitablef o r addition in t.he cis-position. This suggestion appears to clearup much of what was previously obscure.Our knowledge of the physical properties of geometricalisomerides is very scanty; for although it seems probable thatvaluable results might be obtained by a systematic survey of thefield, very few workers have gone far enough into it to provideus with material sufficient for generalisation.I n one direction thisdefect has been remedied by a very complete series of determirmtions of the viscosities of various pairs of stereoisomerides of thistype.38 For the sake of convenience we may term “adjacent” allthe isomerides of the cis-, syn-, and a-types, whilst the trans-, anti,and B-isomerides are classed as “ opposed.” Thole has shown thaty4 T., 1912, 101, 673.y6 Zeitsch. phgsikal.Chem., 1904, 48, 40 ; A., 1904, ii, 525.37 “Die Lagerung der Atome in Raume,” 3 Aufl., 1908, p. 103.38 Thole, T., 1912, 101, 552.35 hfcKenzie, G i d . , 1196188 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.acids and esters differ from one another as regards viscosity rela-tions; for the adjacent acids are less viscous than the opposedisomerides, whilst with the corresponding esters these relations arereversed. The oximes examined, with one exception (benzilmon-oxime), gave results parallel to those obtained with the acids, whilstthe phenylhydrazones appeared to give anomalous readings, and inaddition thei; configurations have not bsen determined with anycertainty.These results led Thole to the conclusion thn.t, of two compoundsthe constituent radicles of which possess small residual affinity, theopposed isomeride has the lower viscosity.This may be ascribedt o the tendency to potential ring-formation which usually existsin the adjacent isomerides, since such a condition notably enhancesviscosity values. I n compounds which possess greater residualaffinity, this factor is masked by the intramolecular neutralisationof the residual affinities, which results in inhibition of molecularassociation, and hence leads to a depression of viscosity. It wouldbe interesting to know, in view of these results, whether the spatialconjugation of unsaturated groups which have no tendency to ring-formation would affect viscosity to any great extent,The Transmutation of cis-trans-Stereoisomerides.One or two points of interest have arisen in this section of thesubject.I n his examination of the conversion of maleic intofumaric acid, Skraup 39 discovered that if hydrogen sulphide andsulphur dioxide were allowed .to interact in a solution of maleicacid, fumaric acid was produced; but that no such change in themaleic acid took place if it were added to the solution after thereaction between the other two substances had run its course; norwas maleic acid affected by the presence of hydrogen sulphide orsulphur dioxide singly. On these phenomena he based his “reson-ance ” hypothesis of transmutation, in which he assumed that everyreaction produces waves in the ether which are capable of settingin motion other reactions which are (‘ in tune ” with the first. Thisproblem has been taken up by Tanatar 40 in a somewhat similar setof reactions. Since in the Skraup reactions sulphur separates fromthe solution, Tanatar examined the action of sulphur on maleicacid. No effect was detected in the case of milk of sulphur or withthe sulphur produced when ferric chloride and hydrogen sulphideare allowed to interact in the presence of maleic acid. The actionof mineral acids on sodium thiosulphate was then tested, and it was3s Monatsh., 1891, 12, 146 ; A . , 1891, 1338..u) J. Auss. Phys. Cheni. Soe., 1911,43,1742 ; A., i, 160 ; Tanatar and Voljansky,ibid., 1912, 441, 1320; A., i, 941ORGAN I C CHEMISTRY. 189found that the presence of maleic acid prevents the normal separa-tion of sulphur, whilst a t the same time the maleic acid is convertedinto its stereoisomeride. It was further observed that the presenceof a mineral acid is unnecessary to produce the transmutation, formaleic acid in presence of s’odium thiosulphate alone is convertedinto fumaric acid. Tanatar concludes from this that in the latterreaction some product is formed which causes the transmutation,and this view makes it unnecessary to assume any “resonance ”phenomena.The action of ultraviolet light on various stereoisomerides hasbeen studied,41 and it is found that the results obtained are notby any means uniform. The influence of constitution appears tobe strongly marked, as can be seen from a comparison of the resultsobtained with the o-, m-, and p-forms of phenylnitrocinnamic acid.Ths o-compound melting a t 196O yields traces of the isomeridemelting a t 1 4 7 O ; the m-derivative melting a t 181O is partly andslowly changed into the isomeride melting at 195O, but the reversechange also takes place; whilst the p-compound, melting a t 143O, iscompletely transformed into its isomeride, which melts a t 2 1 4 O .A new exception to accepted views seems to have been discoveredin the case of a second form of oleic acid42 by keeping a specimenof ordinary oleic acid for some time at a temperature of 8-10‘].Including this new variety (which may, however, differ merely incrystalline form from the others), it appears that we now know offour isomerides in the oleic series, whilst the current stereochemicalviews-only allow for two. It is possible that this might be betterexplained under Michael’s assumptions (compare p. 185).The third isomeride of the erucic acid group, namely, isoerucichas been examined, and it was shown that it can be preparedby simply boiling brassidic acid in alcoholic solution with animalcharcoal. Its absorption spectrum was found to be different fromthose of the other two isomerides, so there appears t o be no doubtthat it is actually chemically individual. Attention might bedirected to these cases which form exceptions to the accepted views.The method devised by Patterson and McMillan44 has beenapplied to the question of the influence of solvent action on thevelocity of transmutation in the case of oximes.45 I n its essentials,this method consists in dissolving the oxime in ethyl tartrate andnoting the change in the rotatory power of the solution, which is41 Bakunin, Rend. Accnd. Sci. Fis. Mat. Napoli, 1911 [iii], 17, 372 ; A . , i,356 ; Stoermer and Heymann, Ber., 1912, 45, 3099 ; A , , i, 974.J2 Kirschner, Zeitsch. physikal. Chem., 1912, 79, 759 ; A., i, 533.Macbeth and Stewart, P., 1912, 28, 68.T., 1907, 91, 504.4J Patterson and Montgonlerie, ibid., 1912, 101, 36, 2100190 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.brought about by the change of the oxime from one isomeric forminto the other. If a neutral liquid be added to the solution of theoxime in ethyl tartrate, the effect of this third substance on therate of oxime transmutation can be deduced from the polarimetricreadings. I n this way the influence of a large number of sub-stances has been tested; for example, it is found that the followingcompounds affect the reaction’s velocity in the order given, thevelocity-constant being highest in the case of benzene : benzene,nitrobenzene, p-xylene, m-xylene, toluene, o-xylene, and mesitylene.I n the case of the aliphatic alcohols the velocity constant decreasesas the series is ascended, methyl alcohol showing most influence.The chief advantage of the method appears to be that the effect canbe traced even when comparatively small proportions of the inertsolvent are present in the reaction mixture.Esterifica tion and Hydrolysis Reactions.As is the case in other fields, the problem of residual affinity hasin recent years forced itself into the region of steric hindrance;and it is generally recognised by workers in this subject that a newfactor has to be taken into account in their investigations. It isnow assumed that in such a process as esterification, for instance,we have to take into account not only the spatial relations of thegroups involved in the reaction, but also their residual a5nity andits distribution within the molecule. I f these two factors remainedconstant, there would be little difficulty in apportioning its dueinfluence to each; but unfortunately they appear t o vary with theconditions of experiment, and thus anomalous results are oftenobtained ; for example, if we esterify acetic and trichloroacetic acidsby the direct method (heating with alcohol) the latter acid esterifiesmore rapidly than the parent substance; but when the two areesterified catalytically (by being allowed to react with alcohol inthe presence of hydrochloric acid) then the reaction velocities arereversed, and the parent substance forms an ester more rapidlythan does the chloro-derivative. Thomas and Sudborough 46 haveexplained this apparent anomaly very simply, by assuming thatboth cases are catalytic processes, but in the direct esterificationautocatalysis takes place, the acid acting as its own catalyst. Ifthis be the case, then the stronger acid, trichloroacetic, should be abetter catalyst than the weaker acetic acid, whereas in the presenceof the much more active catalyst, hydrochloric acid, this advantageis lost and the purely spatial factors come into play.With the view of testing this explanation, these authors haveexamined many acids which had already been studied by the cata-40 T., 1912, 101, 317ORGANIC CHEMISTRY. 191lytic method ; and their remlts certainly point to their explanationbeing correct. If the strengths of two acids (for example, a satur-ated one and its unsaturated analogue, which vary markedly fromeach other in the catalytic result) differ but little from each other,very little difference is observed in their esterification velocitieswhen determined autocatalytically. I n this case, the spatial factorappears to be the deciding one. When, however, this factor is over-borne by the great difference between the strengths of the two acids,the stronger acid is much more rapidly esterified than the other,although this is not the case when both acids react under theinfluence of it catalyst; much stronger than either, for in the latterinstance the spatial factor is again the deciding one.I n the esterification of the ketonic acids, Sudborough 47 has foundthat a carbonyl group in the a-position t o the carboxyl group has amarked retarding influence on the esterification velocity. I n orderto bring these results into line with the fact that the carbonylgroup of ethyl pyruvate was found by Stewart and Baly48 to beabnormally reactive, Sudborough puts forward an hypothesis withregard to the structure of the carboxyl radicle. H e assumes thatin the carboxyl group the hydrogen atom is not attached perman-ently to either oxygen atom, but oscillates from one to the other,so that the change shown below is continually taking place:Such a rearrangement would produce a highly reactive hydrogenatom, and would account for the fact that tho hydrogen atoms ofcarboxyl groups are more reactive than those of alcoholic orphenolic hydroxyl groups. On the other hand, when we come toconsider the rearrangement of valencies between the carbonylgroups postulated by Stewart and Baly:i t is clear that this could only take place a t the expense of thechange assumed by Sudborough, so that although the ketoniccarbonyl group would have an enhanced reactivity, the carboxylicgroup would decrease in reactive power. Sudborough’s suggestionsseem to fit the case very well, and it might be pointed out thatthey could, with very little modification, be brought into line withthe work of Miss Smedley,49 so that they are not devoid of supportin a totally different field.The esterification velocities of various polybasic aromatic acids 6047 T., 1912, 101, 12.27. 48 Ibid., 1906, 89, 489.Wegscheider slid Faltis, Monatsh., 1912, 33, 185 ; Wegscheider ard Black,ibitl., 207 ; A., i, 463 ; Wegscheidcr and Miiller, ibid., 1912, 34, 899 ; A . , i, 771.49 Ibid., 1909, 95, 231152 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.have been studied, and the rates of hydrolysis of various esters ofsubstituted fatty acids51 have also been examined. The results inthe latter case show that esters of halogen substituted acids aremuch more slowly hydrolysed than those of the parent acid.On re-reading the few pages of this report and comparing themwith the volume of the papers published during the year, theauthor feels only too conscious that much of importance has beenomitted, and that many subjects have been very cursorily treated.Not a few researches have been passed over on the ground thatjustice could be done t o them only by entering into details whichwould have necessitated sacrifice of space which could ill be spared;whilst others have been left out because it seemed probable thatfurther investigations would bring out clearer conclusions whichcould safely be left to the hands of later reporters when the subjecthas come into better perspective. A t the same time, it is hopedthat the main lines of progress during the year have been indicated,if not fully described, and that a fair survey of the field has beengiven. If this has been even partly accomplished, the author hasbeen more successful in the task set him than he anticipated whenhe was engaged in collecting the material on which this report isbased.A. W. STEWART.b1 Jhushel, Amer. J. Sci., 1912, [iv], 34, 69 ; A., i, 599

ISSN:0365-6217    

DOI:10.1039/AR9120900073

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

ANALYTICAL CHEMISTRY.THIS report follows the same general plan as that of last year, and,if the plan is not immediately obvious, the brevity of the reportmakes unnecessary any long explanatory introduction. It may besaid, however, that the metals are grouped as they group themselvesin the mind of an analyst rather than by reference to MendelBeff’stable, whilst in the short section relating to organic analysis thegeneral arrangement is the same as that adopted in earlier reports,but without cross-headings, which give an appearance of exhaustive-ness to which this report does not pretend. That the division ofspace between organic and inorganic analysis would be unequal wasclear t o the writer before he finally arranged his notes; theinequality could easily have been redressed, but only, in the writer’sopinion, by omitting more interesting for less interesting matter.Apology is scarcely needed for giving rather extended referenceto one or two matters of importance to analysts with commercialinterests and to some departmental inactivities.General.A new and interesting application of precise thermometry toquantitative analysis has been made.The method depends on theobservation of the precise temperature a t which a solution attainsthe same density as a given, previously calibrated float, and itsapplication is, of course, limited to cases where not more than onesubstance, in addition to the solvent, is present. Since the tempera-ture of floating equilibrium is an almost linear function of theconcentration, when a few points on the curve connecting the twovariables have been determined, the concentration of an unknownsolution may be deduced from the temperature a t which the cali-brated float just sinks in it.Conversely, the method may beemployed to calibrate thermometers by means of solutions of knownconcentration. The exact density of none of the solutions need beknown, since the method depends only on differences of density.Lest it be thought that the method has no advantage over methodsREP.-VOL. IX. 193 1% ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.which correlate concentration with actual density, the followingnumbers may be given. A particular float just sank in alcohol of98.99 per cent. strength a t 15-391O. On adding water so that thepercentage of water in the alcohol was increased from 1.01 to 3-44per cent., the temperature of floating equilibrium was 24*093O, andintermediate experiments showed that the increase of temperatureof floating equilibrium was very nearly a linear function of theconcentration of water.1 Since the float employed was so sensibivethat the temperature a t which it sank or rose could be determinedwithin O*O0lo, a simple calculation shows that the experimentalerror of the met,hod is only about one-tenth that of a methoddepending on the determination of the density of the spirit, withan accuracy of 5 5 units in the sixth decimal place, the highestdegree of accuracy with which densities can be determined withreasonable rapidity.To obtain the greatest accuracy of which themethod is capable, a thermostat capable of being adjusted to anyneeded temperature and of being kept there within 0*005° is neces-sary, and in this connexion reference may be made to a paperon t,he control of temperature in the operations of analytical chem-istrg,2 which should not be overlooked by anyone who may haveoccasion t o design buildings intended for use as laboratories.Electric heating has been made use of in ebullioscopic determina-tions for many years, but Bigelow,3 who first made use of it, pointedout that difficulties due to electrolysis would certainly be encoun-tered if the method were extended to aqueous solutions, and Beck-mann 4 described experiments which confirmed this view.Con-sideration might have convinced these authors that electrolysiscould be avoided by choosing a heating coil of resistance so lowthat the necessary heat could be imparted t o the liquid withoutthe drop in potential across the coil exceeding some assigned quan-tity That their general warning was unsound and their conch-sions only valid for their own coils of relatively high resistance, hasnow been shown experimentally by two authors, who appear to haveworked in ignorance of the work of Bigelow and Beckmann.Thenew apparatus owes its origin to difficulties encountered in %heuse of the ordinary Beckmann apparatus with substances of highmolecular weight and sparing solubility, but it is said to possessthe advantage that readings constant to O*O0lo are obtained withoutspecial precautions, and its general use where the necessary currentis available is t o be expected.6 Of less general interest, but impor-ii, 599.T.W. Richards and J. W-. Shipley, J. Anrer. Chon. SOC., 1912, M, 599 ; A.S. L. Bigelow, Amer. Chem. J., 1899,22, 208 ; A., 1900, ii, 9.E. Beckmann, Zeikch. physikal. Chem., 1908, 63, 177; A., 1908, ii, 663.T. W. Richards, 8th Inter. Cong. Appl. Chem., 1912, 1, 403.ti E. Knecht and J. P. Ratey, T., 1912, 101, 1189ANALYTICAL CHEMISTRY. 195tant in view of the very considerable difficulties which its authorshave overcome, is an apparatus for ebullioscopic determinations a ttemperatures from -36‘3 to -830 with solvents such as hyarogensulphide, chloride, bromide, and iodide.6The work of Thorpe and Rodger is proof that so long ago aa 1894it was possible t o measure viscosities with great exactness.7 Yetuntil recently viscosities of oils have been generally measured inanalytical laboratories by one or other of the commercial instru-ments which are quite unsuitable for scientific research, althoughpossessing an ease of manipulation very desirable in such work.More rarely use has been made of Ostwald’s viscometer, which ismuch easier t o set up than Thorpe and Rodger’s “glischrometer,”an instrument which demands much preliminary work, whilst themeasurements themselves are much more complicated than with theOstwald type of instrument with vertical capillary.Several investi-gations mads within the last few years have, however, pointed tothe fact that the Ostwald type of instrument holds serious sourcesof error, by far the greatest arising from the fact that no correc-tion is made for the kinetic energy imparted to the liquid on enter-ing the capillary,* that is t o say, for the term vd/8?rZt in Pouseuille’sformula 7 = ar4pt / 8Zv - vd/ 8 d t .In the course of an investigationon the viscosity of emulsions, the authors found it possible tosimplify the apparatus9 of Thorpe and Rodger, and one of themhas since described a still further modified form of instrument,which marks a very great advance, not in precision of viscometry-in point of precision the work of Thorpe and Rodger left nothingto be desired-but in the ease and rapidity with which viscositiesmay be measured with a degree of accuracy not far short of thehighest attainable.The instrument is empirical only in the sensethat it is so constructed that the exact dimensions of the capillarycannot be determined, and it must be standardised on some liquidof approximately the same viscosity as the liquids for which it isto be used, and of which the absolute viscosity is known. Thegeneral adoption of an instrument of this type in work on oils,always selecting a, capillary of such dimensions that the kineticenergy correction was less than 0.5 per cent. of the total viscosity,would give a value to future numbers which few of those publishedup to the present possess. The extra demand on the analyst’s timeE. Beckmann and W. Weber, Zeitsch.morg. Chem., 1912, 74, 297; A., ii,Sir T. E. Thorpe and J . W. Rodger, Phil. Trans., 1894,185, A, 410.M. R. Schmidt, BaZti7nore Dissertation, 1909 ; E . C. Bingham and T. C.Durham, Amer. Chem. J., 1911, 46, 278; A., 1911, ii, 968,E. C. Binghain and G. F. White, J. Amer. Chem. SOC., 1911, 33, 1257 ; A.,1911, ii, 858.0 2431196 ANNUAL REPORTS ON TEE PROGRESS OF CHEMISTRY.as compared with the use of one of the commercial instruments isnot very great, and the numbers obtained would be available forthe purpose of correlating viscosities with other physical andchemical properties, whereas the numbers obtained by the commer-cial instruments and in many citses even by Ostwald’s viscometerare insufficiently simply related t o the true viscosities to be of anyuse for such a purpose.10The most important improvements to be recorded in quantitativemicrochemical analysis are the construction of the beam and pointerof the Nernst balance in a single piece, with a glass counterpoisefused on to the beam at the end near the pointer, the substitutionof spongy platinum for asbestos fibre in the construction of theDonau filter, and an ingenious arrangement for conducting precipi-tations and transferring the precipitate to the filter without loss.11A paper which describes the application of Carius’ method to thedetermination of quantities of sulphur or halogens of the order of1 milligram is perhaps deserving of notice even by those who haveso far found no use for microchemical methods.Since 1 milligramof sulphur or halogen can be determined with an error well under2 per cent., the use of somewhat larger quantities should giveresults of sufficient accuracy for many purpoBes, with greatlyreduced risk of serious accident as compared with Carius’ method asusually carried out, besides much saving of space, time, and glass.12Gas Analysis.Last year attention was directed to a new and accurate methodfor the estimation of nitric oxide in the presence of nitrous oxide,a problem which until that date had not found a satisfactory solu-tion.13 An entirely different method, but one which is said to beequally accurate, has since been described.It depends on Raschig’sobservation that the oxidation of nitric oxide proceeds in twostages, the first of which, corresponding with the formation of thetrioxide, proceeds with great rapidity, whilst the second, correspond-ing with the formation of the tetroxide, requires an appreciabletime €or its completion.The method now described consists inoxidat.ion of nitric oxide to nitrogen trioxide and absorption ofthe latter by potassium hydroxide in the form of sticks, the forma-tion of any tetroxide being inhibited by confining the gas togetherwith some potassium hydroxide over mercury, and then admittinga measured and sufficient volume of air. I n this way the nitrogenlo G . F. White, Biochem. Zeitsch., 1911, 37, 482 ; A., ii, 61 ; also J. Ind. Eng,l1 J. Douau, Monatsh., 1911, 32, 1115 ; A., ii, 199.l2 Ibid., 1912, 33, 169 ; A . , ii, 384.Chem., 1912, 4, 106.l3 Am.Beport, 1911, 156ANALYTICAL CHEMISTRY. 197trioxide is transformed into potassium nitrite as fast as it isproduced.14A recent paper on the estimation of hydrogen and methanedescribes no new methods, of which there is already a wide choice,but it does offer very valuable suggestions in regard to four knownmethods. The author shows that the Drehschmidt capillary may bereplaced by it quartz capillary containing a short length of platinumwire of such diameter that it nearly fills the tube, one advantageof the arrangement being that there is no risk of propagation offlame from the heated portion of the capillary to an explosivemixture contained in the gas burette to which it is connected.When using the Winkler-Dennis combustion pipette there is oftendifficulty in burning the last of the methane, so that the operationextends over a considerable period, during which such an amountof mercury may be oxidised as to give rise to serious error.Thissource of error may be avoided by enclosing the electrically-heatedspiral in a quartz tube, which becomes the outer limb of thecapillary U-tube of a simple mercury pipette. The gas is passedslowly to and fro between the burette and pipette over the heatedspiral. It is shown that fractional combustion of hydrogen bymeans of palladium asbestos is successful only if the passage of thegas is slow and the temperature of 400° not exceeded, and aningenious yet easily constructed device is described for controllingthe temperature.Finally, the comparatively new method, depend-ing on the absorption of hydrogen by means of a palladium sol,together with a soluble picrate,15 is dealt with. Although it givesexcellent results, as originally described, the method is renderedtedious by the persistent frothing of the liquid. The froth isinstantly destroyed by a few drops of alcohol, but alcohol makesthe reagent useless for further determinations. For this reason,and because the absorptive capacity of the reagent falls off some-what rapidly on storage, even in the dark, the author has alteredthe whole technique of the method, which, as modified, is economicalboth of the analyst’s time and of the expensive reagent.16I n 1910 a new interferometer was described, by means of whichit was possible to solve simple problems of technical gas analysis.The authors confined themselva, however, to relatively simpleproblems, such as the determination of methane in mine air andthe examination of technical hydrogen.17 It has since been shownthat the instrument may be wed for the analysis of flue gases. I nl4 0.Baudisch and G. Klinger, Ber., 1912, 45, 3231 ; A . , 1913, ii, 74.l5 C. Paal and W. Hartmann, Ann. Report, 1910, 160 ; also 0. Brunck, C?zem.Zeit., 1910, 34, 1313, 1331 ; A., 1911, ii, 149.l6 W. Henipel, Zciitsch. angew. Chewz., 1912, 25, 1841 ; A., ii, 987.l7 Hsberaad Luwe, ibid., 1910, 23, 1393198 ANXUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the absence of carbon monoxide, the results are exact, whilst thepresence of that gas may be inferred if the sum of the percentagesof oxygen and carbon dioxide is appreciably less than it shouldbe, having regard to the composition of the fuel and to the excessof air above that necessary for combustion.18Inorganic Analysis.Qualitatzve.-Since the reference in the report for 1908 to thesystem of qualitative analysis devised by Noyes and Bray,lg twofurther papers have appeared, one by each author.The earlierone dealt with the separation of the alkali earths and the membersof the alkali group,20 whilst the last deals with acidic constituents.21The whole series of papers occupies some two hundred pages, and,since they have not all appeared in the same journal, would be ofmuch greater use if re-issued as a textbook of qualitative analysis.Necessarily these papers contain much that is familiar t o everyone,but it is obvious that they embody an immense amount of originalwork.The number of new methods is so large that the authorsare certain to incur the charge of unnecessarily multiplyingmethods, and analysts of the older school may be expected toexpress impatience of the detailed directions given, but the avowedobject of the authors was to select or devise tests of known androughly equal sensitiveness, and preference has been given tomethods which enable the experienced analyst to form an approxi-mate estimate of the quantities present. Such aims cannot beachieved without close attention to detail.The writer does not share the enthusiasm for methods of qualita-tive analysis which circumvent the necessity for the use of hydrogensulphide, because he finds a hydrogen sulphide apparatus indis-pensable for quantitative separations and for effecting reductions.The ingenuity which has been shown in avoiding the use of thegas, however, is sufficient, even if other evidence were lacking, toshow that there are circumstances where an alternative method isdesirable.Attention was directed last year to the work of Eblerin this connexion.22 The year under review has witnessed theappearance of another comprehensive scheme by an author whomakes no reference to Ebler or any other worker. No new reactionis made us0 of, so that it is possible to appraise the method roughlywithout trial, and it may be said that it might be expected to effect18 0.Mohr, Zeilsch. angezu. Chem., 1912, 25, 1313.I9 Ann. Report, 1908, 181.21 A. A. Noyes, J. Amer. Chem. Soc., 1912, 34, 609 ; A . , ii, 599.a Ann. Report, 1911, 157W. C. Bray, Tech. Quart. 1908, 21, 450; A., 1909, ii, 431ANALYTICAL CHEMISTRY. 199fairly sharp separations, whilst no unduly tedious operations areintr0duced.s It may be specially commended to the considerationof those who are impatient of lengthy descriptions. I n yet anotherpaper dealing with inorganic qualitative analysis as a whole, alarge part is occupied with a description of a scheme which dispenseswith the use of hydrogen sulphide.24It has been shown that tetramethyldiaminodiphenylmethane,previously recommended as a reagent for the *detection of lead andmanganese,25 is a very delicate reagent for gold, solutions contain-ing 1 part of gold in 5 millions developing a distinct purple colouron treatment with it.The metals of the platinum group do notinterfere.26 A microchemical test for manganese, capable of detect-ing 0.005 milligram, has also been described,27 but perhaps the mostnotable achievement in the domain of qualitative analysis has beenthe improvement in the well-known cobaltinitrite test for potassium,the sensitiveness of which has been increased a hundred-fold. Theimprovement consists in making the test in presence of silvernitrate, and depends on the much lower solubility of the doublecobaltinitrites of potassium and silver as compared with that ofpotassium cobaltinitrite or sodium dipotassium cobaltinitrite. Ifthe test is applied after removal of the heavy metals and ofammonium salts, nothing can interfere except rubidium, msium,and thallium, which will seldom be present in quantity where smallamounts of potassium call f o r detection.28&uarttitative.-Chlorate is usually determined to-day by a directiodometric method, but disagreement among different chemists hasled to periodical proposals to return t o the more troublesome distiI-lation method of Bunsen.It has now been shown that the directmethod is exact provided the chlorate be dissolved in air-free waterand the hydrochloric acid used be also freed from air.29 The exactdetermination of chlorite in admixture with chlorate, hypochlorite,and chloride is perhaps not a common problem, but should it arisea new gravimetric method depending on the insolubility of leadchlorite in 80 per cent.alcohol will prove useful, and greatlysimplify the separate estimation of the other constituents of themixture.30H. Trspp, Zeitsch. anal. Chem., 1912, 51, 475 ; A., ii, 685.24 A. Purgotti, Gatzetta, 1912, 42, ii, 58 ; A . , ii, 984.25 A. Trillat, Compt. rend., 1903, 136, 1205 ; A . , 1903, ii, 512.26 R. J. Carney, J. Amr. Chem. SOC., 1912, 34, 32 ; A . , ii, 298.27 M. Wagenaar, Pharm. Weekblad, 1911, 49, 14 ; A , , ii, 206.2* L. L. Burgess and 0. Kamm, J. Amer. Chem. Xoc., 1912, 34, 652 ; A., ii'L9 A. Kolb, Zeitsch. angew. Chem., 1912, 25, 1168 ; also Chem. Zeff., 1912, 36,30 G.Lashgue, Bull. SOC. chim., 1912, [iv], 11, 884 ; A., ii, 988.601.635200 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,It has been shown that, in alkaline solution, the reaction :NeHa + 4K3Fe(CN), + 4KOH = 4N9 + 4K,Fe(CN)6 + 4H20is quantitative until either the whole of the hydrazine or the wholeof the ferricyanide has disappeared, and on this reaction an exactgasometric method for the estimation of ferricyanide has beenbased.31 The method is equally exact when applied to the estima-tion of hydrazine, but the technique is then somewhat complicatedby the action of t h e excess of ferricyanide on the mercury usedas confining liquid, so that, so far as the determination of hydrazineis concerned, the method scarcely challenges the iodine method ofSto116,32 which leaves nothing to be dtxired.Although there is no doubt that Feld’s method for the estima-tion of ferrocyanide i s capable of yielding accurate results inexperienced hands, there is abundant evidence that the hands mustbe experienced, not merely capable, or, in other words, that theconditions which determine success in carrying out Feld’s processhave not yet been defined with sufficient exactness.% I n these cir-cumstances, a new method, apparently less dependent on thepersonal equation, is welcome.It depends on the fact that inpresence of a small quantity of cuprous chloride and excess ofsulphuric acid, all ferrocyanides-ven insoluble ones-are decom-posed with the evolution of the whole of their cyanogen as hydrogencyanide, which may be distilled and determined in the usualmanner.The simplici€y of the method, which is shown t o be exact,should recommend it even t o those who are skilled in the use ofF eld’s met hod .34The usual methods for the determination of fluorides are farfrom exact when very small quantities have to be estimated, andspecial methods which enable a food analyst to assert with confi-dence that an article contains not less than Pome stated proportionof fluorine, although useful to such analysts, are insuffieiently exactfor the purpose of those who are engaged in determining the distri-bution of fluorine in nature, whether it be in living tissues or inminerals of which fluorine is a minor uonstituent. Three papersdealing with the estimation of minute quantities of fluorine musttherefore be accounted important, as they will undoubtedly givegreater value to future statistical work of the kind mentioned.35Having regard to the immense gums paid by chemical manufac-turers for nitrate of soda, the value of which depends solely on itsY1 F’.R. F!&y and H. K. Sen, Zeitsch. anwy. Chem., 1912, 76, 380 ; A., ii, 817.32 R. StollB, J. p. Chem., 1902, [ii], 66, 332; A., 1903, ii, 100.33 Ann. Eeport, 1910, 164.34 H. E. Wilhms, J. Xoc. Chem. Ind., 1912, 31, 468 ; A., ii, 704.y5 A. Gautier and P. Clausmann. Cownt. ~ c n d . . 1912. 154. 1469. 1670. 1763 : A , .ii, 681, 805, 806ANALYTICAL CHEMISTRY. 201nitrogen content, it is remarkable that it should still be paid foron the basis of analytical reports which, in their turn, are based onthe determination of chloride and sulphate (calculated as sodiumsalt), moisture, and insoluble matter, and the subtraction of thesepercentages from 100.The method invariably overestimates thesodium nitrate, the average error being about I per cent., but itmay reach 3 per cent. Not only do all samples contain soluble saltsof calcium, magnesium, iron, and aluminium in small amount, butsodium perchlorate is occasionally present up to nearly 1 per cent.,and the percentage of potassium nitrate may exceed 8 per cent.The suggestion made a t the recent Congress of Applied Chemistrythat the time has arrived for the general adoption of a directmethod of valuing nitrate Will commend itself to all chemists, andsince t.he suggestion came from the spokesman of an importantgroup of American consumers, it may have weight even with thosewho benefit by the present arrangement.There will be lessunanimity among chemists concerning the particular method ofanalysis recommended, namely, reduction t o ammonia in alkalinesolution by means of Devarda metal and distillation from a veryelaborate apparatus.36A method for the estimation of nitrite, depending on the readi-ne,w with which nitrous acid is converted into its methyl ester, andthe low boiling point of the latter ( - 1 2 O ) , is worthy of note. Themethod affords a ready means of determining nitrite in presenceof nitrate, and, although one may not agree with its authors thatno other satisfactory method of effecting this separation exists, thesimplicity and proved accuracy of the new method commend it.Allthat is necessary is to mix the neutral solution with excess ofmethyl alcohol and a known excessive quantity of acid, to bubbleair through the mixture, and then titrate the remaining free acidwith alkali.37The observation that even a small fraction of a milligram ofselenium per litre suffices to bring about rapid destruction of theliquors of sulphite cellulose factories, with production of sulphuricacid and gypsum,38 has led to an investigation on the estimationof minute amounts of selenium in brimstone and pyrites. Brim-stone is burned in a combustion tube in a current of air, an asbestosplug sarving to catch all but an unweighable trace of the seleniumwhich passes forward as a fog with the small quantity of sulphurtrioxide which is always formed; the selenium is dissolved out ofthe tube by means of potassium cyanide, precipitated m dioxide,37 W.M. Fischer axid N. Steinbach, Zeitxh. nnorg. Chem., 1912, 78, 134; A.,38 P. Klasoii, Yereia. Zcll.Jo$ u. P~pitrchcnzikc, 1909, 61.W. S. Allen, 8th. Inter. Cong. AppI. Chenz., 1, 19.ii, 1093202 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.freed by an ingenious device from traces of sulphur, and obtainedas pure dioxide, which is then determined iodometrically.sgThe work of Allen and Johnston on the exact determination ofsulphate made our knowledge of the barium sulphate precipitationnearly complete,40 but it did not provide an easy solution of thepractical problem of valuing pyrites, the most important rawmaterial of chemical industry. A method recently described, if itdoes not solve this problem, goes so far that i t is likely to becomeand remain for some considerable time a standard method.Allenand Johnston’s work made it appear unlikely that an exact methodwould be discovered, which would be generally applicable andrequire no correction, and yet not owe its accuracy to a compensa-tion of errors. The new method is avowedly a compensation method,but it differs from earlier methods of this kind in having beenworked out after and with full knowledge and appreciation of thework of Allen and Johnston. The “barium sulphate” as broughtto the balance always contains barium chloride, but the proportionof this is never less than 0.27 per cent., nor more than 0.30 percent., and so nearly balances the negative errors that the resultsare accurate to 0.05 per cent. How far we have travelled fromtextbook methods of determining sulphate will be appreciated fromthe statement that precipitation is made in the cold, that a Goochcrucible is used, and that the quantity of barium sulphate handledapproximates 5 grams.41 It should be added that the whole methodis as simple as, if not simpler than, any method yet described forthe valuation of pyrites.A rapid yet exact method for the estimation of the free sulphurin spent oxide has long been wanted.A method recently described,depending on the conversion of the sulphur into sodium thiocyanateby digestion with an alcoholic solution of sodium cyanide andtitration of the thiocyanate, is not only rapid but more exact thanmethods depending on the oxidation of the carbon disulphideextract and determination of the resulting sulphate because someof this sulphate may be derived from compounds of sulphur solublein carbon disulphide, but useless to the sulphuric acid maker.42Miiller’s benzidine method 43 for the volumetric estimation ofsulphate has disappointed the expectations that were raised by itsappearance and by Raschig’s44 early investigation of it.For theP. Klason, Arkiv. Kern. Min. Geol., 1911, 4, No. 18, 1 ; No. 29, 1 ; A., ii,201, 990 ; Zeitsch. angew. Chem., 1912, 25, 514.40 Ann. Report, 1911, 159.41 W.S. Allen and H. B. Bishop, 8th. Inter. Cong. Appl. Chem., 1912, 1, 33.42 C. Davis and J. L. Foucar, J. SOC. Chem. Ind., 1912, 31, 100; A., ii, 384.43 W. Miiller, Ber., 1902, 35, 1587 ; A., 1902, ii, 425.44 F. Raschig, Zcitch. angew. Chem., 1903, 16, 617; d., 1903, ii, 572ANALYTICAL CHEMISTRY. 203routine analysis of a number of very similar samples it may some-times be employed with a saving of time; but in other cases thenecessary investigation to determine whether it is applicableoccupies more time than a gravimetric determination. I n manycases the composition of a solution is known within certain limits,and in such cases reference t o two recent papers may inform theanalyst a t once whether the solution is one in which sulphate canbe determined with tolerable exactness by means of benzidine.45Although copper can now be estimated with a degree of exactnessapproaching that of a mint assay of gold bullion,46 the analyticalchemistry of copper and its ores is far from being a book the lastpage of which has been written. On the contrary, the number andvalue of papers dealing with the subject tend t o increase, andsome recent ones must be referred to.Rhead's method47 for thetitration of copper by means of titanous chloride has been greatlysimplified, and shown to be as exact as a volumetric method canbe.48 A new gravimetric method, depending on the selective reduc-ing action of hydroxylamine in presence of alkali tartrate, promisesto be useful, since it is available in presence of antimony, 'zinc,bismuth, lead, iron, arsenic, and reasonable amounts of ammoniaor nitrates.49 The estimation of copper in pyrites has been simpli-fied by the discovery that the aqua regia solution may be directlyelectrolysed if certain conditions, easily realised, are compliedwith.60 A paper and discussion on the limits of accuracy attainablein copper and brass analysis must also be adjudged important, as itshould lead to a diminution in the number of certificates disfiguredby insignificant figures.51 Such figures are not peculiar t o reportson copper and brass, but extend to every branch of analytical chem-istry, and raise a very grave question, which the profession as awhole will be compelled to consider unless amendment is moreprompt than the present writer ventures to hope for.Finally, withregard to copper, attention must be directed to a paper on thedetermination of oxygen in refined copper. It was shown sometime ago that the loss of weight on heating copper drillings inhydrogen is not due entirely to oxygen from cuprous oxide andsulphurous acid, but also includes gases derived by the metal fromthe fuel and other sources, and it is usual now to heat the drillingsto constant weight in a current of carbon dioxide before proceedingk5 K. K . Jarvinen, Ann. Acad. Sci. Fennicae, A, 2, 1910, No. 4 ; 1911, No. 16 ;46 Ann. &port, 1911, 168. Ibid., 1906, 207.48 L. Moser, Chcm. Zeit., 1912, 36, 1126 ; A., ii, 1097.49 A. Baycr, Zeitsch. anal. Chcin., 1912, 51, 729 ; A., ii, 1212.5o W.D. Treadwell, Chem. Zeit., 1012, 36, 961 ; A . , ii, 998.61 E. A. Lewis, J. SOC. Chem. Ind., 1912, 31, 96.C'hem. Zentr., 1912, i, 526 ; A., ii, 486204 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to the determination of oxygen. It is now shown that similartreatment with carbon dioxide should follow the treatment withhydrogen, as copper may occlude so much hydrogen that an oxygendetermination, as commonly practised, may be 20 per cent. inerror.52As every analytical chemist knows, the technique of the Marsh-Berzelius test for arsenic was greatly improved, and the method madevery approximately quantitative in the years immediately succeedingthe unfortunate epidemic of arsenical poisoning in 1901, and every-one who has occasion to determine small quantities of arsenic is nowpractised in this method.The recent statement that for purposesof works control the Marsh test was obsolete, because of its toogreat tedium and expense, would undoubtedly have encounteredlively opposition had it not been the opening sentence of a paperwhich seems to establish the simpler Gutzeit test a t last on a trust-worthy basis. Since 1901 many authors have advocated the use ofthe Gutzeit test, but not even Sanger and Black,53 on whose workthe present authors have largely built, provided for the interferingeffect of small quantities of iron, which are, or may be, present inso large a proportion of the substances which have to be tested forarsenic. The success and general applicFbility of the method nowdescribed depend mainly on the observation that ferrous iron $usa trace of stannous chloride actually increases the sensitiveness ofthe test, and t o keep the conditions uniform, ferrous iron is addedas a matter of routine.54An unusual number of papers dealing with the estimation ofglucinum have appeared within the year.Two volumetric methods,depending on the fact that glucina is so weak a base that solutionsof its normal salh may be titrated with alkali hydroxide usingphenolphthalein as indicator, or made to liberate iodine from asolution of iodide and iodate, have been describedts whilst theconditions which determine the quantitative precipitation ofglucina have been the subject of careful study, with the result thatthese seem t o have been discovered and some older methods shownt o be 20 per cent.in err0r.M A further paper on the separation ofglucinum, aluminium, chromium, and iron should help to makefuture determinations of glucinum easier and more accurate.5752 G. I,. Heath, J. Id. Eng. Chem., 1912, 4, 402 ; A., ii, 1091.53 C. R. Sanger aiid 0. F. Black, J. Soc. Chcm. Id., 1907, 26, 7115 ; A . , 1908,54 W. S. Allen and R. M. Palmer, 8th Intern. Cong. App?. Chem., 1, 9.s5 B. B1eyt.r and A. Moormann, Zcitsch. anal. Chem., 1912, 50, 360 i A . , ii,56 R. Rleycr arid I<. Roshart, ibid., 1912, 51, '748 ; A., ii, 1211.67 M. Wundcr and T. Wenger, ibid., 470 ; A , , ii, 687.ii, 64.491ANALYTICAL CHEMISTRY. 205The difficulties which attend the estimation of chromium inchrom-vanadium steel are admirably summarised in the openingparagraph of a short paper, which proceeds to describe a goodmethod based on the fact previously established by the author inhis work on vanadium,58 that chromium can bO precipitated com-pletely by boiling the nearly neutralised (ferrous) solution withbarium carbonate, and on the observation of Noyes and Bray 59 thatchromate may be separated from vanadate by precipitation as leadchromate if certain precautions are observed.60Ferrous salts may be oxidised to ferric by iodine, provided thereverse reaction be inhibited by suppressing the ferric ion in thesolution as it is formed, and a method based on this fact, althoughlacking the accuracy of the permanganate method, should proveuseful because it is available in cases where organic matter andferric salts are simultaneously present.61 The separation of ironfrom titanium by volatilisation of the former as chloride may beaccomplished at a lower temperature, and with simpler apparatusby substituting a carefully regulated stream of sulphur mono-chloride vapour for the chlorine usually employed.@ Nitrosophenyl-hydroxylamine ( r r cupferron ”), as a precipitant of copper andiron,m has met with comparatively little use, probably on accountof its cost and of the excellent methods already available for thedetermination of copper and iron.I n special cases, however, it hasproved useful, notably as a means of separating iron from phos-phates, for example in plant ashes, as a preliminary to a colori-metric determination of the iron, with which phosphates interfere.64Among the usual host of papers dealing with the non-metallicconstituents of steel and steel-making alloys, three call for notice.It has been shown that Ledebur’s method for the determinationof oxygen in iron and steel may discover none when 0.1 per cent.ispresent, or a9 little as 0.07 per cent. when 0.23 per cent. is present.An exact method is described, but it depends on the use of a 14 kw.furnace.65 In the discussion of Blount and Levy’s paper on thedirect combustion method for determining carbon in steel,66 Arch-butt drew attention to the tendency of the results so obtained t o68 Ann. &port, 1911, 166.69 A. A.Noyes and W. C. Bray, Techn. Quart., 1908, 21, 14.J. R. Cain, J. Ind. Eng. Chem., 1912, 4, 17; A , , ii, 692.61 G. Romijn, Chem. Zeit., 1911, 35, 1300 ; A., ii, 94.a F. Bourion, Compt. Tend., 1912, 154, 1229 ; A., ii, 691.63 Ann. Report, 1910, 165 ; also R. Fresenius, Zeitsch. anal. Chem., 1911, 50,F. E. Nottbohm and W. Weissmange, Zeitsch. Nahr. Genocsm., 1912, 23,W. H. Walker and W. A. Patrick, 81h. lntcr. Cong, Appl. Chem., 1912,21, 139.35 ; A., 1911, ii, 386.514 ; A., ii, 690.66 B. Elount and A. G. Levy, Analyst, 1909, %, 94 j A., 1909, ii, 346206 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.exceed those yielded by wet methods, and other authors have noteda like tendency.67 The difference appears t o be due to the presencein the steel of dissolved carbonaceous gases, the carbon of which isincluded in the values given by the direct combustion method, andalmost wholly lost in the wet meth0ds.a Finally, two papers on theuse of tho calorimetric bomb in the estimation of carbon in steeland steel-making alloys make it appear probable that this is theonly method a t present available for the exact determination ofcarbon in certain alloys, notably high-grade f errochromes andf errosilicons.69The bismuthate method for the estimation of manganese shouldbe so firmly established by now as to need no defence, although itcontinues t o meet with but slighting reference in German text-books, which rank it with the lead peroxide method.However, amiscalculation by one of its critics last year has led to two newcritical investigations70 of the method, which is shown to be atleast as accurate as any known method for manganese, as it isincomparably simpler than any other method with any pretence toaccuracy.A useful note has been published on its application inpresence of much vanadium or chromium.71 It has been shownthat some of the disadvantages of Volhard’s method disappear whenit is applied t o solutions of manganous nitrate instead of to solutionsof the sulphate.72The estimation of magnesia in limestone is referred to amongnew electrochemical methods, of which it is a good type, whilst theestimation of potassium hydroxide in fertilisers, soils, and plantashes is the subject of extended notice among agricultural methods.A spectroscopic method for the estimation of small quantities ofrubidium in presence of much potassium, originally designed onlyto determine the order of magnitude of the rubidium percentage,has proved to be accurate to + l o per cent.73The exact determination of platinum and the preservation ofplatinum apparatus are intimately related problems.As the formerinterests comparatively few, a critical paper on the analysis ofplatinum ores,74 and another on the estimation of small amounts167 H. Isham, J. Ind. Eng. Chen~, 1911, 3, 577 ; A., ii, 387.6* A. G. Levy, AnaEyst, 1912, 37, 392; A., ii, 995.69 P. Mahler and E. Goutnl, Compt. rend., 1911, 153, 649 ; A , , 1911, ii, 937 ;70 W. Blum, J. Amer. Chcm. Soc., 1912, 34, 1379; A . , ii, 1214 ; also 8th Inter.ibid., 1912, 154, 1702; A., ii, 807.Cony.Appl. Chem., 1912, 1, 61; H. F. V. Little, Analyst, 1912, 37, 554.D. J. Demorest, J. Ind. Eng. Chem., 1912, 4, 19 ; A., ii, 690.T2 L. Karaoglanoff, Jahrbuch Univ. Sojia, 1910-11 ; A., ii, 1214.73 E. Wilke-Dorfurt, Zeitsch. anorg. Chem., 1912, 75, 132; A., ii, 686.74 E. V. Koukline, Rev. MLt., 1912, 9, 815ANALYTICAL CHEMISTRY. 207of platinum (and gold) in silver can receive no more thanmention here. A paper on the error of the ordinary parting assayof platinum and silver by means of concentrated sulphuric acid,with a practical suggestion for reducing the error,76 emphasises theconcexion between the two problems, a circumstance which is stillfurther brought out if this paper be read in conjunction with amore recent one on the protective action of a small quantity ofsulphur when evaporating sulphuric acid in platinum vessels.77 Therecent work of Crookes on the volatility of the platinum metals 7* (ortheir oxides) confirms the conclusion of Mylius and Hiittner 79 thatthe improvement in the mechanical properties of platinum by alloy-ing it with iridium is accompanied by the disadvantage thatapparatus made from such alloys suffers greater changes of weightthan purer platinum when subjected to the usual treatment ofchemical platinum apparatus. For the most exact.analytical work,therefore, pure platinum is still t o be preferred, but for manypurposes the mechanical properties of the alloy outweigh its dis-advantages.This can scarcely be said of the alloy of rhodium withplatinum. For fifty years Crookes has made the subject of thepreservation of platinum apparatus so specially his own that hisrecommendation of rhodium alloys 80 must carry weight; but againstit must be set the very careful investigation a t the Reichsanstalt ofa crucible which showed abnormal lose of weight each time it washeated, a property which the investigation appears to correlate withan abnormally high, although absolutely small, percentage ofrhodium .81a s long ago as 1899 Eaufmann showed that thorium could beprecipitated quantitatively, even from very dilute and strongly acidsolutions, by sodium hypophosphate. It has since been found thatthis reaction may be used for the determination of thorium inmonazite sand, an operation which it greatly simplifies.92 So far ithas received little application, and this is in part explained by thefact that the reagent is not yet procurable commercially.It is saidthat this difficulty will shortly be removed, but meanwhile it may75 F. P. Dewey, J. 2nd. Eng. Chem., 1912, 4, 257; also Chem. News, 1912, 106,8 ; A., ii, 810.v6 A. Steinmann, Schweiz. Woch. Chem. Pharm., 1911, 49, 441, 453 ; A., 1911,ii, 1035.?7 L. W. McCay, 8th. Inter. Cong. Appl. Chem., 1912, 1, 351.78 Sir W. Crookes, Proc. Roy. SOC., 1912, A, 86, 461 ; A , , ii, 563.79 F. Mylius and C. Hiittner, Tatigkeitsber. d. Physik. - Tech. 12eichsundalt ;Zedsch. Eleelrochem., 1911, 17, 38.Ann. Report, 1908, 195.81 3lylius and Hiittner, loc.eit.A. Rosenheim, Chem. Zeit., 1912, 36, 821 ; A., ii, 869 ; F. Wirth, Zcitsch.angew. Chem., 1912, 25, 1678 ; A., ii, 948208 ANNUAL REPORTS ON THE PROGRESS O F CHEMISTRY.not be amiss to call attention t o a paper which gives references tothe methods available for its preparation.83Last year an accurate method was recorded for the determina-tion of vansdium in the presence of chromium, but that methoddepended on the use of electrolytic appliances which are not avail-able in every 1aboratory.M Another exact method, available inpresence of chromium, nickel, titanium, manganese, and molyb-denum, and depending on the quantitative inclusion of vanadiumby the phosphomolybdate precipitate, has since been described.85A new method f o r vanadium in presence of ten times its weightof chromium appears to be exact if applied with close attention todetail,86 but how close that attention needs to be is brought outin a joint paper by its author and J.R. Cain.87I n 1909, Weiss and Landecker described a number of newreactions of tantalum and columbium, and on two of them foundeda new method for the separation of these two elements fromtitanium and from each other.88 Their test numbers showed themethod to be more accurate than other more complicated ones. Itwas clear from their paper, however, that success was dependent onthe use of not too large a quantity of nitre in a fusion which wasone step of the process, and one English abstract laid stress on thisfact, and pointed out that the authors did not define this quantitywith the exactness which might have been expected.With thisexception the paper was so convincing that it was with surprise thatthe writer read last year that two other authors had investigatedthe method and found it wholly untrustworthy.89 It has now beenre-investigated with the result that the precipitation by carbondioxide proposed by Weiss and Landecker is shown to be a colloid-chemical phenomenon, a fact which explains the influence of morethan traces of nitrate and the results of the American critics of themethod, and at the same time makes it possible to define therequisite conditions for obtaining accurate results.90 Satisfactoryresults are obtained when the nitrate is omitted altogether.A recent paper on the volumetric estimation of titanium is worthyof note, but it contains no reference to the very careful work ofGernmel1,gl which left little to be desired save increased speed.This83 11. KOSS, Chem. Zeit., 1912, 36, 686; A . , ii, 809.84 Ann. Report, 1911, 165.85 J. R. Cain and J. C. Hostetter, J. Ind. Eng. Chem., 1912, 4, 250 ; A . , ii,87 J. R. Cain and D. J. Demorest, ibid., 256 ; A . , ii, 1101.88 Ann. Report, 1909, 147.89 H. W. Foote and R. W. Langley, Amcr. J. Sci., 1910, [iv], 30, 401; A.,* 0. Hanser and A. Lewite, Zeitsch. angew. Chem., 1912, 25, 100 ; A . , ii, 262.91 Ann. Aport, 1910, 168.1101. 86 D. J. Demorest, ibid., 249 ; A . , ii, 1100.1911, ii, 72ANALYTICAL CHEMISTRY. 209the latest contribution t o the subject accomplishes.9~ For theestimation oE very small quantities of titanium, a colorimetricmethod depending on the use of thymol in concentrated sulphuricacid solution has been proposed.The depth of colour produced isstrictly proportional to the amount of titanium present and twenty-five times as intense as the colour produced by hydrogen peroxide.93As it has been shown that all phenols, especially polyhydric phenolswith adjacent hydroxy-groups, give a similar reaction with quadri-valent titanium, it may be that a reagent even more sensitive thanthymol might be selected.94Electrochemical Analysis.The perpetual rise in the price of platinum in part informs twoother paragraphs in this report. I n no branch is it more felt thanin electrochemical analysis, and a paper on practical electro-analysiswith the weight of the platinum apparatus reduced to 1 gram,which might some years ago have been passed by as a freak, mustbe regarded as a serious and valuable contribution to-day.95 Furtherevidence of the utility of the mercury cathode,96 and of the ground-lessness of the objections that have been raised to it, is adduced,and it is shown that for ordinary purposes it is unnecessary toprovide for the determination of the cathode potential.97 I n otherrespects, too, this paper is inspired by the spirit of reaction againstunnecessary complexity of apparatus which was discernible inseveral directions last year.When a sojution of iron and man-ganese in ammonium oxalah is electrolysed in the presence ofhydrazine sulphate, iron is deposited quantitativeIy, whiIst theh‘ydrazine prevents the deposition of manganese dioxide a t theanode.08 Copper, tin, antimony, and bismuth can be depositedquantitatively and fairly quickly from hydrochloric acid solutions,provided a reducing agent, such as hydroxylamine hydrochloride,is present.99 The electrolytic estimation of zinc in presence ofammonium salts must take place in acid solution, and has beenpossible hitherto only when rotating electrodes are employed.Itis now found that stationary electrodes may be employed providedthat lactic acid and an alkali lactate are present.l92 1’. W. and E. B. Shinier, Slh. h t e r . Poag. AppL Chem., 1912, 1, 4 4 5 .y3 V. Lenhcr and W.G . Crawford, ibid., 285.y4 0. Hauser and A. Lewite, Ber., 1912, 45, 2180 ; A , , i, 847.95 F. A. Gooch and W. L. Burdick, Zcitsch. anorg. Chent., 1912, 78, 213 ; Anaer.96 Ann. Report, 1910, 170 ; ibid., 1911, 168.g7 P. Bmmann, Zeitsch. anory. Chern., 1912, 74, 315 ; A., ii, 489.93 R. Belasio, Ann. Lab. GabeZEe, 1912, 6, 207 ; A., ii, 1097.J. Sci., 1912, [iv], 34, 107 ; A., ii, 986.E. P. Schoch and D. J. Brown, 8th I d c r . Cony. AppZ. Chem., 1912, 21, 81.R. Helasio, Ann. Lab. Gabelle, 1912, 6, 239 ; A . , i i , 1096.REP -\‘Or,. l X 210 ANh’UAL REPORTS ON THE PROGRESS OF CHEMISTRY.An interesting example of another type of electro-analyticalmethod is one which seeks t o determine magnesium in presence ofcalcium by titretion of the magnesium, making use of the factthat when alkali hydroxide is added to a neutral solution containingsalts of calcium and magnesium the concentration of hydroxyl ionsincreases very slowly until all the magnesium is precipitated ashydroxide and then increases rapidly t o the point a t which calciumhydroxide begins to eeparate.2 A somewhat similar method appliedto an easier problem is that which determines nitric acid in amixture of sulphuric and nitric acids by neutralising the solutionwith barium hydroxide, and then titrating it with sodium carbonateuntil the sharp rise in the conductivity announces the completeprecipitation of the barium.3 Applied to mixtures of sulphuricand nitric acids containing only traces of other substances, themethod gives accurate results, but the method of Dutoit andDuboux, for the determination of sulphates in wine,4 which sug-gested it, has now been shown to be untrustworthy.The resultsof Dutoit and Duboux are not impeached, but their accuracy isshown to be quite fortuitous.6 On the other hand, it has beenshown that calculation of the sulphate in water from the knownchloride and nitrate content and the conductivity, whateverobjection may be raised to it, is capable of yielding fair results.6Organic Analysis.Three papers on qualitative methods may be mentioned, namely,one in which the colour developed on treatment with potassiumdichromate and sulphuric or nitric acid is used to divide amino-compounds into four main groups,’ one which provides a ‘systemfor distinguishing a number of the simpler phenols: and one whichserves for the detection of small quantities of maltose, lactose, andmelibiose when these occur together.9Early this year Hibbert issued a warning that the methoddevised by himself and Sudborough for the estimation of hydroxy-,amino-, and imino-derivatives by means of Grignard’s reagent,1°was not EO generally applicable as had been supposed,11 but it hasJ. H.Hildebrand and H. S. Harned, 8th Inter. Cong. Appl. Chem., 1912,1, 217.H. Corvazier, dlon. Sci., 1912, [v], 2, I, 322 ; A, ii, 1092.Ann. lteport, 1908, 207.Chim. anal., 1912, 17, 243.Li A. Bruno and P. T. D’duzay, Coinpt. rend., 1912, 154, 984 ; A., ii, 600 ; Ann.‘I F. Dienert, ibid., 1701 ; A., ii, 807.ti J. A. Sanchez, ibzd., 1911, [iv], 9, 1056; A., ii, 209.H.Agulhon and P. Thomas, Bull. Xoc. chim., 1912, [iv], 11, 69 ; A . , ii, 308.C. Neuberg and S. Saneyoshi, Zeitsch. Ver. deut. Zuckerind, 1912, 559.lo A m . Report, 1911, 170. l1 H. Hibbert, T., 1912, 101, 328ANALYTlCAL CEEMISTRY 21 1since been shown that Zerewitinoff’s modification, using pyridine assolvent, gives theoretical results with each of the substances whichbehaved anomalously in Hibbert’s hands. The method has nowbeen extended to diamines of the aliphatic, benzene, diphenyl,stilbene, and naphthalene series, and it is found that such sub-stances react with two atoms of “active hydrogen” a t room tem-perature, and with three atoms a t 85O, but that the fourth atomdoes not react a t all with magnesium methyl iodide.The oneexception so far recorded is malonamide, which reacts with fouratoms. The hydrocarbons of the indene and fluorene type do notreact a t the ordinary temperature, but a t 8 5 O a quantity ofmethane is obtained corresponding with one atom of “ activehydrogen.” 12This report provides an opportunity for calling attention to amethod for the determination of benzaldehyde, which might other-wise escape attention, owing to its inclusion in a paper with a moregeneral title. It depends on the use of p-nitrophenylhydrazine,and is shown to be far more accurate than any other availablemethod. The same method yields even better results withanisaldehyde add vanillin, but these aldehydee can be determinedwith equal accuracy by other means.13 A new colorimetric methodfor the estimation of vanillin, simpler than th0 methods usuallyemployed, is shown to give accurate results when applied to genuineextracts,l4 but since it depends on the us0 of a reagent which yieldsa similar colour with all substances containing phenol groups,15 itcannot be applied to extracts of unknown origin.The estimationof furfuraldehyde is of importance in the estimation of pentoses andpentosans, and the description of a new method,lO which avoided theuse of phloroglucinol and promised to be more expeditious thanthe phloroglucinol method, was welcome. It depends on the reduc-tion by furfuraldehyde of Fehling’s solution, but its author erredin supposing that the ratio of furfuraldehyde to copper reducedwas independent of the concentration.However, the reducingpower over a range of concentrations covering those which occur inpractice has since been determined, and the method at the sametime simplified.17Konig and Hiihn, having applied each of the principal methotlsfor the determination of cellulose in woods and textile fibros toa number of typical raw materials, reach the conclusion thatl2 T. Zerewitinoff, Ber., 1912, 45, 2384 ; A . , i, 841.l P 0. Folh and W. Denis, J. Id. Ewg. Chem., 1912, 4, 670.B. G. Feinberg, 8th Inter. Cony. Appl. Chenz., 1912, 1, 187.0. Folin and W. Denis, J. Bid. Chem., 1912, 12, 239 ; A . , ii, 1011J. T Flohil, Chem Weekblnd, 1910, 7, 1057 ; A . , 1911, ii, 160.L. Eyno~l and J . H. Lane, AnnEyst, 1912, 37, 4 1 ; A ., ii, 305.r 212 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Konig’s method,’* in spite of the low yield of cellulose obtained,is the best one for the quantitative determination of that con-stituent. Next to Konig’s, the method of Tollens-Dmochowski 19 ispreferred, according to which hydrolysis by the Weende-Henneberg(“ crude fibre”) process is followed by oxidation with nitric acid.It is said that Cross and Bevan’s chlorination method fails toremove most of the hemi-hexosans and pentosans.20 Cmss andBevan remain convinced that the chlorination process, properlycontrolled, will remain the standard method for the estimation ofcellulose.21 Where experts differ so widely, i t is not for the presentwriter to express an opinion, but it is permissible to say that theissue seems to turn on the definition of “cellulose.”Innumerable methods have been described for the detection andapproximate estimation of small quantities of methyl alcohol.Forsome of these, based on the oxidation of the methyl alcohol toformaldehyde and detection of the latter by some old or newreagent, an extraordinary degree of sensitiveness has been claimed.I n practice, however, most of them have proved to be a t the mostbut new colour reactions of formaldehyde, for which other tests ofgreat delicacy have long been known, whilst they did nothingto advance the practical problem of detecting methyl alcohol inthe presence of ethyl alcohol, since, unless the oxidation is carefullyregulated, ethyl alcohol gives rise to acetaldehyde, which interfereswith some of the tests, or even to formaldehyde, which upsets themall.As a result of a careful study of the conditions necessary topreserve the ethyl alcohol from oxidation, one of the later proposalsof DenigSs 22 has been so far improved upon that it is now possibleto detect with certainty 0.05 per cent. of methyl alcohol in 90 percent. alcohol, and to determine larger quantities with an error notexceeding 4 per cent. of the amount of methyl alcohol present.23 Anovel proposal for the estimation of alcohol in pure aqueous solutiondepends on the fact that when sufficient potassium fluoride is addedto such solutions, two phases separate. If water be now addedgradually, a point is reached when the solution again becomeshomogeneous, and this point can be determined very closely if alittle solid spirit blue is present, since this makes a very thin filmof alcohol easily visible.The paper is accompanied by tables forJ. Konig, Ber., 1908, 41, 46 ; 1908, ii, 236.I9 R. Dmochowski and B. Tollens, J. Landw. 1910, 58, 1 ; A., 1910, ii, 554.~0 J. Konigand F. Huhn, Zcitsch. Farb. Itid., 1911, 10, 297, 236, 344, 366 ;21 C. F. Cross and E. J. Bevan, ibid., 1912, 11, 197 ; A,, ii, 1105 ; also 8th Inter.2? G. DenigBs, C‘ompt. rend., 1910, 150, 832 ; A., 1910, ii, 461.23 C. Siminonds, Analyst, 1912, 37, 16 ; A., ii, 208.19 2, 11, 4, 17, 37, 57, 77, 102 ; A , , ii, 1005.Cong. Appl. Chem., 1912, 13, 101ANALYTICAL CHEMISTRY. 213the use of the analyst.Although potassium fluoride cannot beused for the production of alcohol of a strength exceeding 97.5 percent., its dehydrating action is more rapid than that of most dryingagents, and it absorbs as much as 62 per cent. of its weight ofwater against 32 per cent. taken up by lime.24An interesting development of Walden's observation that, undercertain conditions, uranyl salts produce a marked change in thespecific rotation of Z-malic acid, is a practical method for theestimation of malic acid in fruit juices.25 The determication ofsmall quantities of salicylic acid in presence of much p-hydroxy-benzoic acid is less frequently required than the converse p r oposition, but a method by which it may be effected is interestingas an example of a new type of biochemical method of analysis.It depends on the fact that Penicillium glaucum can utilise p-(andalso m)hydroxybenzoic acid for its nutrition, whilst salicylic acid,in quantities of more than 1 per cent., greatly retards, if it does notwholly inhibit, the growth of the organism.26Attention may be directed to two papers on the volumetricestimation of azo-dyestuffs by means of hyposulphite. I f thelimitations of the method are obvious, so are its practical advan-tages in cases where the results of the titration are free fromambiguity.27The selection, for notice in this report, of methods relating tothe analysis of foods, drugs other than definite chemical substances,and still more of natural fats and oils, is attended with difficulty.Of the papers that one can point to as unquestionably of value,the majority concern themselves with constants and ratios, andalthough in the aggregats they advance our knowledge considerably,i t is only occasionally that any one or any group carries our know-ledge of some problem of general interest to a point where a sum-mary of progress made can be usefully attempted.Of new methodsexperience forbids one to expect that more than a very few willprove at the best more than alternatives for existing ones, whilstby nothing short of actual trial can one distinguish between testslike that of Halphen for cottonseed oil, which has proved specificand approximately quantitative, and the hundreds of colour testswhich have been described since, and since forgotten.EvenHalphen and those who have used his test for fifteen years have24 G. B. Frankforter and F. C. Frary, 8th Inter. Cong. Appl. Chem., 1912, 22, 87.25 P. B. Dnnbar and R. F. Bacon, J. Ind. Eng. Chem., 1911, 3, 826; A., ii,699.26 J. Roeseken and H. J. Waterman, Proc. K. Akad. Wetensch. ilmslo.dnm, 1911,14, 604 ; A . , ii, 306.27 E. Grandmougin and E. Havas, Chem. Zeit., 1912 36, 1167 ; A., ii, 1220 iW. Siegmund, Monalsh., 1912, 33, 1431 ; A., 1913, ii, 82214 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been lucky if the recent statement proves correct that Halphen’sreaction fails if the amyl alcohol employed is a carefully purifiedsample.28 Fortunately, even if true, this does not touch theprinciple of Halphen’s test, as Veley’s work did absolutely destroythe whole basis of the Girard-Cuniasse method for the determinationof the higher alcohols in potable spirits, and as Chapman’s worklimited the conclusions to be drawn from the so-called tests forcreatinine and hydrogen cyanide by means of picric acid.Thehistory of these three methods, however, one good, one bad, andone indifferently good, but all a t some time in daily use by manyfood analysts, g-oes to show that the early literature of a colourreaction is not likely to provide internal evidence by which it maybe appraised.It was stated by the reporter of 1910, whose opinion on thissubject is entitled to special respect., that the methods of Jollesand Lcmeland €or the estimation of sucrose in presence of reducingsugars, even if trustworthy, which was open to doubt, had noadvantage over existing methods.29 That neither is as accurateas might be desired has since been demonstrated, but the formeris shown to afford a ready means of determining sucrose in con-densed milk with a satisfactory degree of accuracy,30 whilst thelatter has been so far improved that, in its modified form, it isrecommended as a substitute for the Clerget-Herzf eld inversionmethod in the analysis of sugars and syrups, and especially as aroutine method for the determination of the sucrose-content oflow-grade products like hobroom goods.31Reference was made last year to a cryoscopic method for deter-mining whether a sample of milk, abnormally low in non-fattysolids, owed its abnormality to addition of water or to naturalcauses.% For three years the method has been applied to alldoubtful samples in the Government Laboratory a t Brisbane,% butunfortunately it seems to form no part of the duty of any officialin this country to investigate a method a knowledge of which mightperhaps have reduced the number of cases of miscarriage of justicein the autumn of 1911.Richmond’s annual paper on the coni-position of milk shows that the average for non-fatty solids fell inAugust, 1911, almost to the legal minimum, whilst 27 per cent. ofall the samples examined were below the standard.% In only a28 E. Gastaldi, Ann. Lab. Gabellc, 1912, 6, 601 ; A., ii, 1108.29 A m . Report, 1910, 174.H. Nowak, Zeitsch. anal.Chem., 1912, 51, 610 ; A . , ii, 1004.W. E. Cross and W. G. Taggart, Zntem. ASugar J., 1912, 14, 444.32 Ann. Report, 1911, 173.33 J. B. Henderson, AILS. Assoc. Adv. Sci., 1912, 13.3A H. D. Richniond, Aitnlyst, 1912, 37, 298ANALYTICAL CHEMISTRY. 215few cases, however, was evidence of this kind available a t the time,and in not a11 of those cases did i t carry the necessary weightbecause based on comparatively few samples.Fiehe and Stegmiiller have examined most of the methods whichhave been proposed for the examination of honey, and give detaileddirections for carrying out the tests they have found most useful.35Fiehe’s test for artificial invert sugar 36 is now firmly established,but has perhaps not reached its final form, as another new reagenthas been recommended,37 whilst useful suggestions have been madefor avoiding the interference of formaldehyde and some other sub-stances which may be present,38 and a Ihird paper gives hints onpreczutions to be observed in carrying out the process, some ofwhich may save the analyst trouble.% Langer’s serological test 40has been further studied, and i t is found that the quantity ofthe precipitate is not diminished by previously heating the honeyunless a temperature approaching looo is reached, and maintainedfor ten minutes or longer.41A new method for the estimation of shell in cocoa powdersdepends on the precipitation of cocoa-red by means of ferric chloridefrom an acetic acid extract of the cocoa.It is claimed that i t willdetect with certainty the addition of 10 per cent.of shell to“normal cocoa.” In conjunction with other tests, it may proveuseful, ’but the figures given in the paper show that, if this testwere the sole criterion, i t would be possible to add nearly 40 percent. of shell to cocoa from one part of the world, and thenplead as excuse, for its low content of cocoa-red, the normal contentof the latter in cocoa grown elsewhere.42 T. Macara has developedFilsinger’s levigation method for the determination of shell to suchan extent that the authors of a recent b00k,43 as yet the only placeof publication of the modified method, express the opinion that itis of more value than any chemical method yet available for thepurpose. Another mechanical method depends on the use of amixture of chloral hydrate, glycerol and water, having a specificgravity of 1.5, and the use of a centrifuge to separate the heavierportions of the shell (about a third of the whole) from the rest ofthe mixture.44rs Arhtit.Kaiscrl. Gesiindhcitsnmte, 1912, 40, 305.36 Ann. Report, 1910, 174 ; 1911, 174.37 G. Armani and J. Bartoiri, Ann. Lab. Gabelle, 1912, 6, 85.39 L. Stoecklin, ibid., 116 ; A . , ii, 499.40 Ann. Report, 1910. 1 7 i ; 1911, 1 7 4 .41 J. Thoni, Mitt. LcbcnPmilteltLnters~~ch. 16. Hyg., 1912, 3, 74 ; Chem. Z i t . ,42 C. Ulrich, Arch. Phnmz., 1911, 249, 524.4i “ Fatty Foods,” by E. R . Rolton and C. Revis (Churchill), 303.44 L. Kalnsky, Zeitsch. Nahr. Genwsm., 1912, 23, 654.G. lidphen, Ann.Fulsif., 1912, 5, 105 ; A . , ii, 498.1912, 11. 151216 ANNUAL REPORTS ON THE PHOGRESS OF CHEMISTRY.Concerning the best method for the determination of nicotinein tobacco extracts, there is still disagreement, but the method ofBertrand and Javillier,l5 depending on the precipitation of nicotineby means of silicotungstic acid, is now admitted by T6th-theauthor of a rival method-to leave nothing to be desired in pointof a c c u r a ~ y . ~ ~ Thus at least three methods have survived thecriticism which has been so active during the last three years.47There can be no doubt, however, that that criticism has soundedthe death-knell of the method of Ulex after a useful life of twenty-five years, although there are commercial reasons for believing thatits burial may be deferred.**Attention may be directed to a new method for the separatedetermination of citronellal and geraniol in citronella oiI,49 and toanother for the direct determination of the geraniol, which dependson the conversion of the citronellal into its oxime, which passesinto the nitrile on boiling with acetic anhydride to acetylate thegeraniol, the nitrile being unaffected by the potassium hydroxidesubsequently used to saponify the acetylated oi1.60A recent method for the determination of the preservative, softresins, in hops is probably the most accurate yet described.Thatit will prove too tedious for commercial purposes is recognised byits authors, but they have made use of it to compare the accuracyof the quicker methods in general U S ~ .~ I They find that th‘e latestform52 of Lintner’s volumetric method gives results within a fewtenths of 1 per cent. of those yielded by their own, whilst that ofBriant and Meacham,53 the first practical method evolved for thepurpose, and still the prevailing one in this country, always under-estimates the soft resins, and may in some cases underestimate therdby as much as 50 per cent. The paper is written with a clearerappreciation of earlier work than is usually shown by writers onthis subject, the literature of which is difficult to piece together.Mention is made earlier in this report of the use of the calori-metric bomb in the determination of carbon in steel. A similarmethod is now employed in the United States Bureau of Mines45 G .Bertrand and M. Javillier, Bull. SOC. chim, 1909, [iv], 5, 241 ; A . , 1909,46 J. T6th, Chem. Zeit., 1912, 36, 937 ; A . , ii, 1010.47 Ann. Report, 1911, 174.49 See, for instance, F. Porchet and P. Tonduz, Chem. Zeit., 1912, 36, 843;49 V. Boulez, Bull. Soc. chim., 1912, [iv], 11, 915 ; A . , ii, 1105.50 J. Dupont and L. Labaune, Ann. Chim. anal., 1912, 17, 210 ; A . , ii, 697.O1 H. V. Tartar and C. E. Bradley, J. lnd. Eng. Chewi., 1912, 4, 209.52 C. J. Lintner, Chem. Zeit., 1908, 32, 1068 ; see also D. Neumaun, Wuchensclb.53 L. Briant and C. S. Rleacliam, J. Insl. Brcwing, 1897, 3, 233.ii, 450 ; Ann. Chim nnnl., 1911, 16, 251 ; d., 1911, ii, 827.R. Kissling, ibid., 1321.f. Brauerei, 1910, 27, 281ANALYTICAL CHEMISTRY.217for the determination of sulphur in oils and all other combustiblematerials. Of theother methods available for this determination in oils, only thatof Carius and those depending on combustion in a current ofoxygen are accurate. None of the methods depending on combus-tion in oxygen contained in a large glass bottle is trustworthy,nor are methods depending on fusion with alkalis and subsequentoxidation, fusion with alkalis and an oxidising agent, or wet treat-ment with alkalis and oxidising agents, although the three last typesof method, of which there are many varieties, are excellent forsolid fuels.54 Ten methods, all of which find use for the determina-tion of water in petroleum, have been subjected t o a critical exam-ination, and it is found that the most accurate is that dependingon the volume of hydrogen evolved when the sample is treated withfinely-cut sodium.55Agricu l tural Analysis.Subject to correction by those exclusively devoted to agriculturalchemistry, the writer would characterise as the most importantpaper affecting British agricultural analysts, one on the estimationof potassium.56 Yet there is little in the paper that is new.It isshown that the perchlorate method is 'far superior to the platinummethod, not only on the ground of cost, but as being freer fromerror, simpler, and less likely to give rise to differences betweendifferent analysts. All this information was available a t least aslong ago as 1909, when Precht stated that the perchlorate methodhad almost superseded the platinum method throughout Germany.57The present paper includes an improvement on Neubauer 's simpli-fied method, which will prove of special value in dealing with smallquantities of precipitate, but the importance of the paper as a wholedepends less on the new information it conveys than on the fact thatit is dated from Rothamsted, and may therefore expect to resultin action by the Board of Agriculture, which apparently is notadvised of analytical progress in foreign countries.The case isurgent. Analysts under the Fertilisers and Feeding Stuffs Act arerequired to determine potassium in fertilisers by the platinummethod, t o take large quantities of substance for analyfis, and tomake declaration that the analysis was made in accordance withthese and other directions of the Board,a and these regulations neces-54 I.C. Allen and I. W. Robertson, 8th Inter. Cong. App!. Chem., 1912, 10, 25.55 I. C. Allen and W. A. Jacobs, ibid., 17.56 W. A. Davis, J. Agric. Sci., 1912, 5, 52.57 Precht, 7th Inter. Cong. Appl. Chem., 1909, I, 146 ; also 6th Congress, 1906.58 Board of Agriculture and Fisheries, Statutory Bales and Orders, 1908, No.The method is rapid and as accurate as any.9642'18 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.sarily affect the practice of other analysts besides official agriculturalchemists. I f the platinum method is to be used, the use of largequantities makes for accuracy, yet quite recently two of the bestknown London analysts differed by nearly 3 per cent.in the caseof a sample of 90 per cent. sulphate of potash.59 I n view of factssuch as these, there is no necessity or excuse for deferring theofficial dethronement of the platinum method until the perchloratemethod, which admittedly falls short of exactness, has been furtherrefined A notable feature of the paper is the frankness with whichnumbers leaving much to bo desired in point of accuracy are usedto sustain the argument and yet not overstate the case. Sincefrequent alterations of official methods of analysis are attendedwith inconvenience, the Board might a t the same time invite privatecriticism of their other methods of analysis with a view to there-casting of these. So unfortunately are they worded that thewriter has heard it suggested that they must be the work of achemist with so strong an objection to the principle of officialmethods that he drafted this set t o discredit that principle.Thewriter must not be held to endorse this opinion, but that i t can beexpressed, even in jest, reflects seriously on a document which hasthe force of law.Modern legislation has made official methods necessary, but insome cases the legislative enactments or statutory rules and ordersmade under them have been in advance of the knowledge necessaryto frame satisfactory methods. A case in point is the use of astandard solution of ammonium citrate. Such a method has beenofficial in the United States for some years, and the Americanchemists did their best to define the hydrion concentration-onwhich the results obtained by the use of the solution are closelydependenbso far as this could be done with chemical indicators.Yet i t is possible for two chemists, experienced in the method, toreport, one 3 per cent., the other 5 per cent.of insoluble phosphatein one and the same sample. If electrical appliances are availablefor determining the hydrion concentration of the standard solution,satisfactory concordance is easily established, but many labora-tories lack the necessary equipment.60 Fortunately, this test isnot official in Great Britain, but in a t least one of our colonies everyfertiliser must be registered with a declaration, which must alsoappear on invoices, that i t contains not less than so much " citrate-soluble" phosphoric acid.A proclamation by the Governor of theColony 61 defines the strength of the citric acid solution to be used59 Davis, Zoc. cit.60 A. J. Patten and C. S. Robinson, J. Ind. &zg. C h c ~ , 1912, 4, 443 ; A . , ii,61 Proclamation by tha High Commissicner for South Africa, 5 Dec., 1910.1094ANALYTICAL CHEMISTRY. 219with basic slag, which is identical with that in use in nearly allcivilised countries, but is silent concerning the more or less neutralsolvent to be applied to all other fertilisers, which demanded rigiddefinition, if indeed the use of such a solution for official purposescan be recommended a t all in the present state of our knowledge.A discussion on the methods available for the rapid yet suffi-cienhly exact determination of phosphoric acid in soils 62 was chieflyremarkable for the absence of any reference to the lead molybdatemethod?! which, if not quite so rapid as some, is probably the mostexact of tho approximate methods, and possibly the most exactmethod available where the quantity to be determined is verysmall.Water Analysis.It is on the actual concentration of hydrogen ions, and not onthe potential acidity or alkalinity as given by ordinary titration,that the rate of action of water on metals depends.Electrioalmeasurements of this concentration are difficult in some circum-stances-for example, on board ship-and require appliances nota t the disposal of every analyst. Modifications of Siirensen’smethod of colour comparison with standards prepared from thesalts N+HPO, and KH,PO,, water and standards alike being tintedwith a suitable indicator, are free from this objection, and the useof his method made possible the collection of much useful informa-tion during a cruise made for hydrographical purposes from theBaltic to the Black Sea.64 A recent proposal to state the resultsof such a comparison in a new way, although certain to arousecriticism, will commend itself to the water analyst, and do much toestablish the method as it recognised part of a complete wateranalysis. Briefly, the proposal is to state the acidity or alkalinityof a solution in terms of the acidity or alkalinity of water at thesame temperature; thus a water with a hydrion concentration of1 * 3 6 ~ 1 0 - ~ a t 1 8 O would be said to have a relative acidity of 2 orrelative alkalinity of 0.5. One advantage of the method is that theresults thus stated are nearly independent of temperature. Anotherand by no means insignificant one, is that the client without scien-tific knowledge will have less difficulty in appreciating the signi-ficance of the analyst’s numbers. The proposal is accompanied bytables which do away with all calculation, and place the method a tthe disposal of anyone who will make up two standard solutions.6563 S. J. M. Auld, Anal@, 1912, 37, 130.63 H. Rrearley and F. Ibbotson, Analysis of Eteel- Works Materials (Longnians),64 Palitzsch, Compt. rend. des Travaux tlu Lab. de Carlsberg, 1911, 10, 85 ; also55.Bwchent. Zeitsch., 1911, 37, 116; A., ii, 39.J. Walker and S. A. Kay, J. Soc. Chent. lnd., 1912, 31, 1013 ; A . , ii, 1215220 ANNUAL REPORTS OX THE PROGRESS OF CHEMISTRY.A paper which draws attention to the fact that, in carbonatedwaters, ammonia may be much underestimated, unless special pre-cautions be taken, should not be overlooked, although othermethods for securing accurate results, besides that proposed by theauthors, may readily suggest themselves.66 Since the last referenceto water analysis in these reports,67 Chamot and Pratt, in collabora-tion with Redfield, have brought to a conclusion their importantresearches in connexion with the estimation of nitrates by theGrandval and Lajoux method. Those researches have laid bare themechanism of the Grandval and Lajoux reaction, hitherto whollymisconceived, and establish on sound principles the precautionsnecessary to attain the best results of which the method is capable,but these precautions and the results are such that the authors maybe said to have assisted to destroy the method to the investigationof which they have given so much labour. To known waters themethod may often be applied, and in such cases reference to thework cited will save the analyst trouble and increase the accuracyof his results; but as a general method it cannot compare withothers which are nearly if not quite as quick and far more trust+wort hy.68G. CECIL JONES.66 G. D. Elsdon mid N. Evers, Analyst, 1912, 37, 173 ; A . , ii, 601.67 Ann. Xeeport, 1910, 181.E. M. Chrtmot, D. S. Pratt, and H. Mr. Redfield, J. Amcr. Chenz. Soc., 1911,33, 366, 381 ; A , , 1911 ii, 331

ISSN:0365-6217    

DOI:10.1039/AR9120900193

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

PHYSIOLOGICAL CHEMISTRY.DURING the year 1912 no prominent person in the bio-chemicalworld has passed away, nor are there any new books in thisbranch of science to announce. The only item of general newsnecessary to mention is the fulfilment of the hope expressed in lastyear’s report that the Bio-chemical Club founded in 1911 wouldblossom into a Society with a journal of its own. This is now anaccomplished fact. The Rio-chemical Journa2, which has hithertobeen edited by Professor Benjamin Moore and Mr. Whitley, ofLiverpool, will in future be conducted by the newly-founded Bio-chemical Society, and issued by the Cambridge University Press.As editors, the services of Professor W. M. Bayliss and Dr. A.Harden have been secured ; bio-chemists will watch with interest thenew enterprise, and wish it every success.Periodical literature, which it is the special duty of this reportto review, was never more bulky ; physiological chemistry is stillremarkable among the sciences for i@ fruitful and steady growth.The papers published deal with every corner of the science, andadd fresh bits of knowledge to many subjects.The mere fact,however, that in the general run the expression “bits of know-ledge ” is correct, renders the arrangement of a systematic resumedifficult within a reasonable space.Among the many problems a t which work has been diligentlydirected the following few are the most important. The gaseousmetabolism in individual organs is still steadily being examinedunder the leadership of J.Barcroft, but there are no striking newfacts. What has appeared relates to organs other than those previ-ously examined, the same methods with slight modifications hereand there having been employed. This sort of work is none theless valuable, but the accumulation of data is always dull workfrom the reviewer’s point of view. Closely allied to this questionis the continued discussion as to whether there are any circum-stances under which the lining membrane of the lung activelysecretes oxygen into the blood. J. S. Haldane and his co-workershave definitely abandoned the view that such secretion takes22222 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,place normdly, and investigators are now happily unanimous thatphysical diffusion alone explains the gaseous interchanges whichoccur in the lung.The upholders of the secretion theory, how-ever, still feel doubt whether that theory should be abandonedaltogether, and believe that under stress (for instance, at greataltitudes) the pulmonary epithelium is able to exercise the propertyof piling up oxygen into the blood which it inherits from theswim-bladder of ths fish. Renewed work can alone show whetherthey are right.The ductless glands are still fertile fields for work, and perhapsthe most interesting papers which have appeared on this subjectare those by Prof. Carlson and his colleagues a t Chicago on therelationship of the thyroid and parathyroid bodies to tetany. Theaction ol adrenaline again is not fully worked out yet, and quitea large number of papers have appeared on this subject.It isoften noticed that the effect of a drug on an isolated organ differsfrom that which ensues when the same organ is in the intact body:for a drug may act indirectly on an organ by stimulating thesuprarenal gland to activity, and the effect observed is really anadrenaline effect.Dale and Laidlaw 1 have worked out this ques-tion especially on the uterus and on the eye, and it appearsfikely that this factor will play an important part in future investi-gations; and no doubt other organs than the suprarenal will havealso to be reckoned with.Since the foregoing paragraph was written, a series of papers2from Starling’s laboratory has appeared, which demonstrate theimportance of the suprarenal factor in many cases of elevatedblood-pressure where it was previously unsuspected.The rise ofarterial pressure which occurs, for instance, when the splanchnicand other nerves are irritated, or when the amount of carbondioxide in the blood is increased, is in part due to the pouringout of adrenaline into the circulation.The activities of enzymes of all sorts, the lipoids, creatine andcreatinine, the scientific exploration of drug actions, the largesubject of immunity and its offshoots, such as anaphylaxis, all theseand many others claim mention in the year’s output.The wide word metabolism covers a multitude of researches, andneaqly every aspect of this important subject has received atten-tion. One may particularly single out, for a passing reference, thequestion of nuclein metabolism, and express the hope that Levene1 Proc. physiol.Soc., 1912, xii, J. Physiol, 44 A., ii, 667. Also J. Physiut,1912, 45, 1 ; -4,, ii, 854.G. von Anrep, J. Physiol, 1912, 307, 318 ; S. Itatni, abid., 338 ; A., 1913, i, 121,136.One only I will mention a little more fully in passingPHYSIOLOGICAL CHEMISTRY. 223and his fellow-workers will succeed in unravelling the constitutionof the animal nucleic acids. I dealt with the question of nucleicacid a t some length last year, and it is too soon to make freshpronouncements ; the nucleic acid which Levene made the subjectof his .noteworthy work was mainly of vegetable origin (for instance,that of yeast), and this he showed to be a complex of phosphoricacid, certain bases, and a pentose (ribose).In the acid of animalorigin (for instance, that from the thymus gland), the place of thepentose is taken by a hexose, and one awaits with considerableinterest the work already started in relation to it.sAfter this rapid review of some of the aspects of the year’s work,l e t us now pass on t o enumerate the subjects which I have chosenfor a more extended notice.I shall take up first one or two subjects suggested by the well-worn but still unsettled theme, “The origin of life.” Next Ipropose to deal with certain aspects of metabolism, namely, repair,growth, and synthesis in the animal body. Then will follow some-what more briefly a review of a few important recent papers onblood-clotting, and finally I shall conclude with equally shortreferences to two pathological subjects, namely, dropsy andneuritis.The Origin of Life.This subject loomed large on the horizon during the autumn,for it was naturally the part of Professor Schafer’s PresidentialAddress at the Dundee meeting of the British Association whichattracted popular attention.The extremely useful and lucidaccount of recent physiological progress which he gave as a sequelto the more speculative portion that opened the address passedalmost unnoticed. We should all, of course, like to know forcertain what was or what is the actual origin of life on this planet,but that, also of course, was just what Professor Schiifer failed togive us. The speculations advanced were given with due scientificcaution, and as the years go by and knowledge grows, hypothesesrest on surer foundations, bu€ the time has not yet arrived whenone can assert with safety that a living organism or a livingmolecule is only the result of chemical and physical forces operat-ing on inorganic parent material.One may perhaps be boldenough to state that it is becoming more and more difficult to denysuch an assertion,It is not, however, my object to continue in these pages thelengthy and sometimes futile discussions which sprang out of theaddress, in the newspapers, a t the sectional meetings of the Asso-ciation itself, and more recently in Science Progress. It howeverLevenenlid Jacobs, J. Biol. Uhem., 1912, 12, 377, 411 ; A., i, 926224 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.occurred to me that it might be of interest to deal with one or tworather more matter of fact pieces of original research which aresuggested by the phrase “ The origin of life,” although the relation-ship may not be obvious a t first sight.The first of these may be entitled the Continwtnce of Life.Fromthe very earliest days of scientific physiological experiment theimportance of a study of the excised portions of a dead frog’s bodywitg recognised, and our fundamental notions of such phenomenaas the contraction of muscles and the beating of the heart arederived from such investigations. The far-reaching results whichhave followed the investigation of what it is now the custom toterm (‘ surviving organs ” are known to every physiologist, and areapprehended even by the first year’s student of that science.Nowthat it is possible to apply this method to mammalian organs also,the additions to knowledge have been still greater and of morepractical benefit. Thanks to the fluid known as Ringer’s solutionas modified by Locke, one is now able to keep an isolated mam-malian heart under observation, and manifesting all its livingactivities for hours, and even for days. Thanks to Ross Harrison’smicroscopic technique, it is possible to keep snippets of embryossmall enough for histological observation, aliv’e and active in ahanging drop of lymph; one can see the cilia still moving, one canwitness the transformation of an undifferentiated protoplasmic massinto a striated muscle fibre, and, above all, one can watch the nervefibres growing out of nerve cells, and shooting forth in a distaldirection a t no mean speed.Harrison was thus able to show bydirect ocular evidence the truth of His’s doctrine that the peri-pheral nerves are the outgrowths distalwards of processes from thecentral nerve cells, a doctrine which was accepted previously oncircumstantial evidence alone.It is true that in such observations, no living properties arebestowed on the matter under observation, but the mere fact thatliving activities can be maintained by purely artificial means of achemical nature, after the organism as a whole is dead, renders itincreasingly di5cult to postulate any specific and mysterious vitalforce.Wonderful as such results are, they are entirely thrown intothe shade by the more recent achievements of certain investigatorsa t the Rockefeller Institute of New York.By the use of appro-priate culture fluids, the cells of cmcerous and other tumours havebeen watched growing and multiplying for weeks, and A. Carrel4has succeeded in keeping his tissues alive longer than two months.I n general terms the culture media employed are the plasma andJ. Experi?iz. Med., 1912, 15, 516 ; 16, 165PHYSIOLOGICAL CHEMISTRY. 225serum of blood at a suitable temperature, but the tissues remainin it latent phase in cold Ringer’s solution, and resume activitywhen warmed. His most striking experiment was done with frag-ments of heart muscle; such fragments grew and commenced topulsate, and were still pulsating in vitro three months after theywere removed from the body.Carrel was previously known for hisexpert surgical skill in transplanting blood vessels and otherorgans, an entirely different branch of research, and the NobelPrize he has just been awarded is some slight recognition of thevalue of his investigations.The other set of experiments to which we will now pass are in asense the counterpart of these, Just as organs which underordinary conditions would be dead can be made to live, 80 methodswhich were previously employed only for dead organs can now beapplied to those which are alive. I refer to what is called Zntra-vitam staining, of which Prof. Goldmann, of Freiburg, is the chiefexponent.Prof. Goldmann has published several monographs onthis subject, and his most recent one is in the Beitrage f, Klin.Chir.6 A very useful summary of his main results appeared in theProceedings of the Royal Society about the same date.6 The oldermethods in which methylene-blue was injected into the blood streamwere limited t o the differentiation of specific tissues; Ribbert wasthe first to attempt a vita1 stain by intravenous injection ofcarmine; but the results achieved were so uncertain that suchmethods never passed into general use, and the toxic effects of theinjections were usually sufficient to kill the animal.A new departure in this field resulted from the attempts to curediseases caused by trypanosomes and other protozoan parasitesthrough the agency of aniline dyes, such as trypan-red and trypan-blue; and BouflFard, of the Pasteur Institute, investigated the histo-logical appearances in the cells of the body which ensued.Quiteindependently Goldmann took up similar work, and made anextensive study of normal rats and mice injected with trypan-,isamine-, and pyrrhol-blue solutions. His early results werepublished in 1909, and since then his method has been improved,and the work extended to include pathological conditions. Aftersuch injections the animal suffers from no ill-effects, and the onlyoutward sign of a change in a white rat is that it is now a blue rat.When the animal is subsequently killed, the sections prepared fromits tissues are found to be differentiated by the stain in a chwacter-istic way; those of us fortunate enough to see the demonstrationswhich Prof.Goldmann gave before the Royal Society and thePhysiological Society were struck, not only with the beauty of the1912, 78, 1. 1912, 3, 85, 146.REP.-VOL. IX. 226 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.preparations, but also with the usefulness of the new method in theelucidation of function. The dye can be administered either intrapvenously, intraperitoneally, or subcutaneously. The actual detailsof the technique, and the chemical constitution of the dyes men-tioned and also of others which have been recently added to thelist will be found described in full in the papers already quoted.What we me mainly concerned with here are the results.The stain is embodied in the granules of specific cells throughoutthe body. Although it circulates in the blood, no blood corpuscletakes it up, nor has it any effect on the vascular lining.I n theskin it is found in the fixed connective tissue cells, but chiefly infree cells in the lower layers of the cutis and subcutis. But thesemigratory cells appear also in every internal organ (except thenervous system), and always in connexion with interstitial fibroustissue; they occur in muscles, glands, tendons, and especially inserous membranes. They have chemotactic irritability, and arephagocytic. On account of their affinity for pyrrhol-blue they wereoriginally termed pyrrhol cells, and it seems probable that theyoriginate in the bone marrow.By means of intra-vitam stains one can further differentiate theKupffercell of the liver, the reticulum cell of lymph glands andspleen, the interstitial cell of the testis, the follicular cell in thematuring follicles of the ovary, the cortical cell of the suprarenal,the epithelial covering of the choroid plexuses, and the cells whichline the convoluted tubules of the kidney.When pregnancy occurs in the stained animal, the appearanceand behaviour of the placenta are most striking; the blue colourdisappears from the skin, and is concentrated in t.he uterua, andin time the latter, forming a centre of attraction for the dye, ulti-mately dispossesses all the remaining tissues of their blue, In theuterus it is the free cells of the decidua serotina where the stainia mainly found.In quite early stages the stained cells penetrateinto the primitive placenta and cast off their stained granules,which ar0 snatched up by foetal cells in the way nutritive materialis. When once the placenta has attained maturity, however, the dyeis found only in the foetal cells which form the layer that separatesthe maternal and foetal tissues. The embryo itself remains per-fectly colourless, the stain not being able t o penetrate this protec-tive barrier. Further research haa shown another important point ;for the same cells which vigorouely absorb the vital stain store alsoglycogen, fat, and hemoglobin temporarily before these substancespass into the foetal circulation.The avidity of such cells for thedye is thua connected with their functional activity in relation toreally nutritive material; the importance of vital staining inembryological research is therefore apparentPHYSIOLOGICAL CHEMISTRY. 227Equally important are its applications to pathological research.I n the healing of wounds the pyrrhol cell appears on the sceneafter the initial emigration of leucocytes has taken place. It eats upthe leucocytes or ingests the glycogen and fat which are derivedfrom leucocytic disintegration. Eventually it becomes the spindlecell of the new connective tissue in the scar, and simultaneouslyloses its affinity, both for the blue dye and for fat stains.I n trichinosis the activity of the pyrrhol cell is prominently dis-played ; it wanders towards the uncapsuled parasites, passing in itsway through lymphatic glands.The cells then spread into theinterstitial muscular tissue, and finally, penetrating the sarcolemma,arrange themselves on the outer surface of the imprieonedtrichinae.In tuberculosis a fundamental difference was discovered in thedistribution of avian and bovine bacilli when grafted into theperitoneal cavity of the mouse. When bovine material is employed,i t first cause-s extensive tuberculosis of the peritoneum itself, andthe chief seat of further trouble is in the lungs, whither the bacilliare carried by the blood stream after penetrating the portal vein.The pyrrhol cells take no active part in this acute form of experi-mental tuberculosis.An entirely different result follows injectionof the avian bacillus. The peritoneum and the organs within itshow hardly any trace of the disease. The omentum, however, isfull of blue patches, which are composed entirely of pyrrhol cells,the blue protoplasm of which is choked with myriads of bacilli. Theliver, spleen, mesenteric glands, and to a less extent the lungs are alsostudded with similar aggregations of pyrrhol cells which have actedas phagocytes and so protect the animal from the disease. In theliver the Kupffer cells play a similar r61e. In the end, however,the protective action ceases, and the brave defenders succumb whenthe parasites increase still further. The pyrrhol cells then lose alsotheir affinity for the blue dye, and show an increased affinity forfat stains, and finally disintegrate, allowing the bacilli to be distri-buted t o the body generally uia the lymphatic vessels, and not bythe blood stream as in the case of the bovine bacilli.I n toxic degeneration of the liver produced by poisons such asphosphorus, the organisation after such non-inflammatory necrosisis attempted by vitally stained pyrrhol cells, which migrate alongthe liver lymphatics from the peritoneum towards the diseasedtissues, and eventually assist in the repair of the damage.Last, but not least, the new method appears destined to play apart in the elucidation of the mysteries of cancer and similar malig-nant growths. Here the aggregations of blue-stained pyrrhol cellsattain extraordinaq dimensions ; they swarm round the growingtumour, penetrating i t along its numerous blood vessels.I n theQ 228 ANNUAL RESORTS ON THE PKOGRESS OF CHEMISTRYinterior most of them succumb. It is just here that the interestingstory stops, or is to be continued in Professor Goldmann’s next?He is content to state that he a t present regards the appearanceof the blue cells as a specific local reaction induced by the tumourcell. No other migratory cell is attracted, and i t may be thatthese cells are the bearers of nutriment. He has, however, alreadycommenced some experiments on mouse tumour with Ehrlich’sicterogen and sodium iodophenylarsenate. These poisons producetoxic degeneration of the liver, and are more powerful in thisdirection than phosphorus. The pyrrhol cells then absorb thedegenerated products of the liver cells, preferably t-he bile-pigments,and transport them to the malignant growth.Hence the latter maywear both on its smface and in its interior a distinct yellow orjaundiced appearance. Since the tumour evidently suffers throughthe application, it does not seem improbable that the pyrrhol cellmay also be active, or may be rendered active in transportingmaterials t o the tumour which impede and even stop its growth.It will be seen that this subject promises to become one of greatimportance from the biological point of view, and zt8 time goes onthe more specially chemical aspect of it will become clearer. Themore strictly chemical side of the question, both in reference to thedyes themselves and to the method of their action on livingcells, is treated in two interesting papers by W.Schulemann.7Repair, Growth, and Synthesis in the Animal Body.Our increased knowledge of the composition of proteins, the(‘ flesh-forming ” constituents of diet as Liebig termed them, hasshown us that all of the members of that large group have veryunequal powers in repairing the body waste. It is also now recog-nised that repair of the tissues which are fully developed is notthe same thing aa the active growth of the body which occurs beforethe adult stage is reached, and that food which is efficacious inthe former may be quite ineffective in the latter condition. Recentwork on metabolism has also shown that man cannot live on proteinalone, even if it is mixed with fat and carbohydrate to supply thenecessary energy, but that there we other organic compounds ofuncertain nature which often in very small quantities are absolutelyindispensable.Another general result of this renewed investiga-tion haa been the discovery that the animal body possesses a powerof syntheeising comparatively simply food material into morecomplex substances, which waa previously considered to be thespecial feature of vegetable life.I propose in the following section to illustrate these t h a w by7 Arch. Pharm., 1912, 250, 252, 389 ; A,, ii, 791, 859PHYSIOLOGICAL CHEMl STRY. 229alluding to the more important papers in the year’s output thatsupport them.I n order to estimate the nutritive value of any article of food,experiments in vivo are absolutely necessary; no amount of merechemical analysis or observations of digestion in vitro are sufficient,however useful they may be as accessory methods of research.Thesort of work on the utilieation of individual proteins which iswanted is well illustrated by that of Mendel and Fine8 on theproteins of various cereals and legumes. Mendel, in conjunctionwith Osborne? has carried the matter further in their extensiveexperimente on rats, and shown that it is possible to keep theseanimals alive for prolonged periods (equivalent to the average lifeof the rat) when a single protein is the sole source of nitrogenoussupply; and it is by means of such observations that they havereached the important conclusion that maintenance and growthare not the same problems.From the wealth of detail which isgiven t o support this contention, I take but 2 solitary example,which is quite typical and obtained from the examination of ananimal higher than a, rat. A gliadin food mixture was given to apuppy in place of its mother’s milk; this produced typical failurein growth, although the mother dog thrived on the same diet andactually produced young, and secreted milk in sufficient quantityand quality to induce normal growth in her offspring. No strongerproof could be adduced of a power to synthesise “ Bausteine ” inthe body which are absent from the food. McCollumlO makesthe useful suggestion, seeing repair processes are of a differentcharacter from those of growth, that in cell katabolism and repairthe processes do not involve the destruction and re-synthesis of anentire protein-molecule ; this is obviously necessary during growth.A similar power t o synthesise lipoids from simple phosphorisedcompounds on a diet free from fats and lipoids was further deter-mined by the same authors.11 But restricting ourselves for thepresent to the question of proteins, one must allude next to a seriesof papers which deal with amin*acid synthesis and the chemicalpossibilities of the transformation within the body of one amine* J.Biol. Chem., 1911, 10, 345 ; 1912, 10, 433 ; 11, 1, 5 ; A., ii, 63, 271, 272.Full details inPublication 156, Part 11, Carnegie Inst. of Washington, 1911; A., ii, 271.Zcitsch.physiol. Chm., 1912, 80, 307 ; A,, ii, 957. J. Biol. Chem., 1912, 12,473 ; A., ii, ,1190. The same note, namely, the different r81e of proteins i nmaintenailce and growth, is struck by McCollum, Amer. J. Phpiol., 1911, 29, 215 ;A., ji, 63. For feeding on single proteins are also Rohmann, Binchem. Zeitsch.,1912, 39, 507 ; A., ii, 462, and Osborne, Mendel, anc! Miss Ferry, J. BWZ. Chem.,1912,13, 233 ; A . , 1913, i, 124.Proc. Amer. physiol. SOC., 1911, xii, Amer. J. Physiol, 29.lo See preceding footnote.l1 Osborne, Mendel, and Miss Ferry, J. Biol, Chcm., 1912, 12. 81 ; A., ii, 779230 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.acid into another. The early members of the series were brieflymentioned in last year's report, and G.Embden12 and his colleagueshave continued the work, and supported their contentions by actualexperiments in vivo (perfusion of liver, etc.). I do not proposehere to repeat the details, the essentials of which have alreadyappeared in our abstracts, but would merely point out that workof this kind is increasing by leaps and bounds our knowledge of theintimate processes of nutrition and metabolism, and demonstratesbeyond cavil the wonderful synthetic powers which animal csllspossess. The liver is credited with the bulk of the work, but thistendency to pile up hepatic duties is somewhat discounted by someresearches to be alluded to a, few paragraphs ahead. Another factorto be reckaned with is insisted upon by the American writers justmentioned, and that is bacterial action.It is quite possible thatsome of the new chemical permutations and combinations are theresult of the activity of micro-organisms in the intestine ; seeingthat bacteria are always with us, this possibility cannot beneglected; but knowing also that it has been shown that healthyanimal life is possible with a perfectly sterile alimentary canal, itis impossible t o resist the conclusion that the tissue cells are moreimportant than these accessory factore.Loewi, Abderhalden,13 and others alluded to in previous reportshave shown that it is possible to maintain animals alive and inhealthy equilibrium by feeding them on the simple " Bausteine "of the food if they are given in appropriate proportions. No one,however, would have ventured t o prophesy that simple ammoniumsalts could replace aminclacids, or could be synthesised into tissueprotein.This, however, appears to be probably true, and the yearjust passed is remarkable for a number of papers on this aspectof metabolism. The principal ones which deal with it are givenin the footnote below,l4 but seeing that the subject is as yet in itsinfancy, one would perhaps be wise a t present to adopt the cautiousattitude of Abderhalden, who draws the general conclusion thatalthough ammonium salts and especially the acetate influence thenitrogen balance, and may lead t o the retention of nitrogen, never-12 Biochem. Zeitsch., 1912, 38, 393, 407, 414 ; A., ii, 278, 279. See alsoAbderhalden and Hirsch on the formation of glycine in the organism (Zeitsch.physiol.Chem., 1912, 78, 292; A., ii, 579.Striking recent experiments of this kind are given by Abderhalden, 'Zeitsch.physiol. Chem., 1912, 77, 22 ; A., ii, 363.14 E. Grafe and Schlapfer, Zeitsch. phpiol. Chem., 1912, 77, 1 ; A., ii, 363 ;E. Grafe, ibid., 78, 485 ; A., ii, 659 ; Voltz, ibid., 79, 415 ; A , , ii, 780;Abderhalden, ibid., 78, 1 ; A., ii, 575 ; Abderhalden and Lamp&, ibid., 80, 160;A., ii, 956 ; Abderhalden and Hirsch, ibid., 136 ; A., ii, 957 ; Ibid., 81, 323 ; A.ii, 1189 ; Abderhalden and Lamp&, ibid., 82, 21 ; A . , ii, 1191 ; Abderhalden andHirbch, ibid., 1 ; A., ii, 1190 ; E. Grafe, ibid,, 347 ; A,, 1913, i, 125PHYSlOLOGICAL CHEMISTRY. 28 1theless the assumption that animal cells can build up proteinfrom ammonia and non-nitrogenous material (carbohydrate, etc.),is not yet proved up to the hilt; it is quite possible that the retainednitrogen may bo in other and simpler combinations than protein.Now let us return to the point about the part played by the liverin such syntheses. I n several previous reports I have dealt withthe question of protein absorption, and have throughout main-tained the position that the complete (or almost complete) cleavageof proteins into individual amheacids in the alimentary canal isfollowed by the absorption of these simple substances into the blood.Those which are of special importance in repairing the tissue waabare seized upon by the tissue cells to which the blood conveysthem, and the unused residue is deamidised, and its nitrogen ulti-mately excreted as urea. Deamidation and formation of ureaappear to be a special function of the liver, and has been generallyassumed to occur rapidly.I have always strongly combated theidea to which Abderhalden among others has committed himself,namely, that re-synthesis of protein from the amino-acids occursduring absorption in the intestinal wall.The work of 1912 has supported these contentions absolutely.I n the first place, Folin and Denis15 have published a most impor-tant set of papers which they have entitled “Protein metabolismfrom the standpoint of blood’ and tissue analysis.” Folin is justlycelebrated for t.he introduction of new and accurate analyticalmethods, and now his newly-introduced methods have been auccess-ful in proving that after the ingestion of proteins, or of amineacids, it is perfectly easy to demonstrate and estimate an increasein the non-protein and amino-acid nitrogen of the blood.A newpoint made out is that deamidation does not occur so rapidly as wepreviously thought it did.These observations have been oriticised in two directions. Folisstated that a certain amount of nitrogenous absorption occurs inthe stomach; London 16 considers this cannot be stated positivelyunless the remainder of the alimentary canal is excluded, forabsorption from the auto-digestion of intestinal juices might con-ceivably be occurring, Folin,” however, has successfully defendedhis own point of view.After all, the point is only a minor one.Speaking personally, I am inclined to think that more accurateconclusions can be drawn from normal animals than from thosewith extensive mutilations such as London employs.The other criticism comes from Abderhalden and Lamp6,18 whol5 J . Biol. Chrm., 1912, 11, 87, 161 ; 12, 141, 253, 259 ; A., ii, 271, 364, 780,l7 J. Biol. CILcm., 1912, 13, 389 ; A., 1913, i, 126.853. l6 Zeitseh. physiol. Che?n, 1912, 81, 283 ; A , , ii, 1189.Zeitsch, physiol. Chcm., 1912, 81, 473 ; A., ii, 1100232 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.also deal with a minor point, namely, a question of chemical tech-nique in the methods used. They suggest a modification for detect-ing amino-acids in the blood. The main importance of thisapparently critical paper resides in the admission that after feedingan animal on meat or on proteolytic cleavage products the blooddoes contain excess of amino-aoids which pass into it direct fromthe intestine.We can only hope that this means that Abderhaldennow definitely abandons his view that protein synthesis occurs inthe intestinal wall.19 The same question is taken up by Buglia,mand he also arrives at the conclusion that synthesis, of protein fromits cleavage products does not occur in the wall of the intestine.Let me conclude this discussion by some quotations from a paperby D. D. van Slyke,21 which puts the problem very well, and showsthat all physiological chemists throughout the world are fallinginto line in regarding the intestinal wall as no specific place forprotein synthesis, and are also beginning to doubt whether themuch-burdened liver has such multifarious duties as those it isusually credited with. He begins by describing a method forestimating amino-acid nitrogen in blood, for van Slyke, like Folin,is fertile in methods.By its use he shows that in fasting animalsthe amount of amino-acid nitrogen is 0*003-0*005 gram per 100 C.C.of blood. Absorption of 10 grams of alanine from the intestineincreases this figure, and in the normal digestion of meat theamount may be more than doubled. The rapidity with which amino-acids disappear from the blood was illustrated by injecting10 grams of alanine direct into the blood+&ream; five minutes lateronly 1.5 grams were left in the blood, and 1.5 grams passed intothe urine; so the remainder must have been taken up by thetissues. The theory that amino-acids are synthesised into blood-protein whilst passing through the intestinal wall therefore becomessuperfluous, and there can be no doubt that they pass as such intothe blood from the intestine, amd then are rapidly removed fromthe blood by the tissues.The liver, moreover, appears to play nospecially active part in picking up these acids; doubtless all thetissues help themselves. This conclusion is based on the observationthat the blood of the femoral artery during digestion containsnearly as much amino-acid nitrogen as that in the mesentericveins.I have elected to devote mmt of the preceding paragraphs in thissection to the proteins, but it must not be supposed that theLQ That Abderhalden was weakening in this view was indicated in a previouspaper (Abderhalden and Kramm, Zeitsch.physiol. Chem., 1912, 78, 382 ; A., ii,574). Here he states that his experiments do not contradict the theory.20 Zeitsch. Biol., 1911, 57, 365 ; 1912, 58, 162 ; A., ii, 182, 462..J. Biul. Chem., 1912, 12, 399 ; A., ii, 1184PHYSIOLOUICAL CHEMISTRY. 233problems of nutrition and of synthesis in the body are not alsoequally interesting in relation to carbohydrates and fats.Exigencies of space, however, preclude more than a passing refer-ence to these. In fact, I shall confine myself to two subjects only,one of which is connected with carbohydrate metabolism, and theother with one of those unknown but indispensable components ofa healthy diet to which I referred in the opening paragraph of thissection.GZycoZysis.-The disappearance of sugar from the body, and itsultimate oxidation with the formation of carbon dioxide and water,is a question of unusual interest, not only because the intermediateproducts are matters of discussion, but chiefly because the internalsecretion of the pancreas is believed to play its part in glycolysis.Of the various tissue cells investigated by Levene and Meyer,B onlyone species hitherto has shown itself capable of causing glycolysis,lactic acid being an intermediate stage in the combustion of sugar;these cells are the leucocytes of the blood.It is, however, wellknown, as was first demonstrated by 0.Cohnheim, that the com-bined action of muscular tissue and pancreatic extract causes sugaradded to the mixture to disappear. Knowing, moreover, that sugaris the main source of muscular energy, the phenomenon wasexplained by supposing that the normal action of the internalpancreatic secretion on reaching the muscles was to facilitate thecombustion of sugar; and the absence of that secretion after extir-pation of the pancreas explained the accumulation of sugar and theoccurrence of a diabetic condition. This view will certainly haveto be revised in the light of Levene and Meyer’s recent workF3 iftheir discovery is confirmed, and one cannot at present see any flawin their methods. The sugar certainly disappears, but it is notburnt up into oxidation products; in other words, sugar disappear-ance is not glycolysis in the usual acceptation of the term. Thedisappearance of the sugar is due to condensation into a poly-saccharide, and the sugar can again be recovered after hydrolysiswith acid.Here, indeed, we have a riddle that badly needs aguesser.Accessory Factors in Normal Dietaries.-The reader will nothave failed t o notice in this report how largely America has figuredin the research of the year. I attribute this largely t o the wisdomof our Transatlantic cousins in providing adequate endowment forresearch, so that the ablest and keenest of American minds meattracted to devote themselves to what is under usual conditionsunremunerative labour. My insular prejudices, however, lead me22 J.Biol. Chem., 1912, 11, 361 ; 12, 265 ; A., ii, 577, 852.23 Ibid., 347 ; A., ii, 577234 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.to congratulate myself that I am able in concluding this section toallude to an important metabolic research by a f ellow-countryman.F. G. Hopkins was one of the earliest to recognise the importanceof what for want of a better name we term the accessory factorsin a dietary; and the effect of quite small quantities of suchsubstances is admirably illustrated in his most recently publishedpaper.24 Groups of young rats were fed on a basal diet of casein-ogen, fat, carbohydrate, and salts, and compared with other ratson the same diet plus a minute ration of fresh milk.The formersoon ceased t o grow; the Iatter grew normally. The consumptionof food was practically the same throughout, but the milk adden-dum reduced the food necessary for a given increment in weightt o one-half or less. Cessation of growth occurred before loss ofappetite appeared. What the actual substances are in the milkwhich thus markedly, although in a secondary way, affect growthis not yet known.Beri-beri. Polyneuritis.The importance of minute quantities of certain materials in thediet is well exemplified in the causation of that terrible disease ofthe East known as beri-beri. The interest of the subject leads met o supplement what I said last year on this disease, and to breakthrough my usual rule in not taking up the same subject two yearsin succession.It may now be taken as proved that the diseaseis usually produced by a diet of polished rice, that is, rice deprivedof its outer layer in which the anti-neuritic substance occurs. Itcan be cured by the administration of the polishings, or of theactive substance separated from them. The rapid progress made inthe discovery of the cause, and the cure of the condition illustratesthe usefulness of animal experimentation, for the disease can beeasily oaused in birds, and now it can be as easily cured. CT. Funk,who was the firat actually to separate out the anti-neuritic prin-ciple, which he terms vitamine, has not yet fully made out itschemical composition, but he states in his latest paper25 that itsproperties suggest it is a pyrimidine base, and forms a constituentor derivative of nuoleic acid, For curing pigeons of polyneuritis,doses of 0.02 to 0.04 gram given by the mouth are sufficient. Thesame base he also separated from yeast, ox-brain, milk, and possiblyfrom limejuice.Schaumann’s hypothesis that a deficiency oforganically combined phosphorus in the food leads to a similarpoverty of phosphorus in the body, and thus to neuritis is therefore24 J. Physiol., 1912, M, 425 ; A . , ii, 779.z5 Ibid., 1912, 45, 75 ; A, ii, 856PHYSIOLOGICAL CHEMISTRY. 23 5not confirmed, and H. Wieland26 arrives at a similar conclusionfrom his experiments on mice.27Moore, Edie, and others28 a t Liverpool have also separated outthe base, and have used yeast as the material to work with.Theysuggest the name tordin. On treatment with barium hydroxide itgives off trimethylamine, and they ascribe to it the formulaC,H,,O,N,HNOs. They are, however, continuing the investigation,and the elucidation of the actual chemical composition of the basecan only be a matter of time. The important practical point isthat its existence and action have been proved.The amouut of vitamine in various articles of food has beendetermined by ascertaining how much of each must be added to adiet of polished rice in order to prevent in birds the occurrence ofpolyneuritis.28a It was found that the anti-neuritic material isirregularly distributed amongst the foodstuffs ; thus 20 grams ofbeef daily were necessary; about half this amount of sheep’s brainproved to be sufficient, and among the animal foods examinedegg-yolk was the most efficient, 3 grams being the necessary dailydose.Amongst the vegetable foods, the efficiency of lentils andunhusked barley were about equal to egg-yolk, but, of all others,yeast was the most efficient in preventing the disease, only 0.5 grambeing enough.The question will doubtless be asked, especially by sufferers fromneuritis, is this discovery of any use to them. The proof of thepudding will be the eating thereof,.and there appears no reasonwhy they should not try. Vitamine is, a t any rate, quite harmless,but whether it will be of widespread therapeutic value is anotherquestion. A cure which is scientifically sound is one thatremoves the cause of the ailment.In beri-beri, a disease due tolack of the base, the cure by the administration of the base istherefore only common sense. But neuritis is caused in other ways,by pressure on a nerve, by inflammation of the sheath of the nerve,and so forth. There is no reason t o believe that in this countrythe sufferers have been on a diet free from or even poor in thisparticular substance. So that although we may hope that thegiving of the drug may assist in alleviating the condition, it doesnot strike a t the root of the miachief, and so one must be verycautious in holding out hopes of any great relief.26 Arch. expt. Path. P?Larm., 1912, 69, 293 ; A., ii, 9152.5 The contradictory results of observers iu their attempts to cure polyneuritiswith lecithin is due to the fact that lecithin is often contaminated with vitaminewhen prepared from animal organs (H. Maclean, Bio-Chcm.J., 1912, 6, 355 ; A,,ii, 1192). 2a Bio-Chetn. J., 1912, 6, 234 ; A,, ii, i 9 4 .an E. A. Cooper, J. Hygicne, 1913, 12, 436236 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.A very remarkable cam of beri-beri has recently been describedby V. L. A n d r e ~ s , ~ ~ in which rice played no part. It occurred ina suckling infant of a Philippine mother, and was cured by with-holding from it the milk of its mother. Analysis of the milkshowed nothing noteworthy in its general composition ; the calciumand phosphorus were even higher than usual. Yet there must havebeen a failure of some substance in the milk, presumably of thevitamine, which is a normal constituent of that fluid; young dogswere fed upon it, and all of them developed peripheral neuritis,Edema, and dilatation of the right side of the heart; in fact, all thesymptoms typical of beri-beri.Such cases as this widen the outlook and form a useful comment-ary on the remarks just made concerning the multiplicity of causesthat may lead to the development of the neuritic condition.In concluding this section, I may mention the very useful term“ deficiency diseases,” introduced by Funk for beri-beri, scurvy,pellagra, and a few other pathological conditions due t o defectivediet.Coagulation of the Blood.The theory most in vogue at present to account for the pheno-menon of blood-clotting is that of Morawitz; and this theory is anamplification of Hammarsten’s, which in its original form postu-lated the existence of two factors; one of these is fibrinogen, aprotein substance in solution in tlie blood-plasma, and the other isan agent which is liberated by the disintegration of the corpuscularelements of the blood, and which on account of its enzymelikecharacters was called fibrin ferment, or thrombin.The action ofthrombin on fibrinogen resulted in the formation of fibrin fromthe latter. Hammarsten even in his earlier papers noted thatcalcium salts favoured congulation, and the prime importance ofsuch salts was fully demonstrated by the subsequent work ofPekelharing, Arthus, and others, who showed that coagulation couldbe entirely prevented by decalcifying the blood by the addition ofsmall quantities of a soluble oxalate.The analogy between blood-clotting aad milk curdling by rennet suggested that the part playedby calcium in both processes was identical. It has been proved thatthe clot in milk is a calcium caseate, and at first it was supposedthat fibrin was a calcium compound of fibrinogen. But it was soonfound that this is not the case. The part played by calcium in theclotting of blood is in the production of the thrombin, and not inthe subsequent action of thrombin on fibrinogen. Like otherenzymes, thrombin has an inactive procursor, which has receivedgg Philippine J. Sci.I 1912, 7, 67PHYSIOLOGICAL CHEMISTRY. 237the name of prothrombin, and what the calcium does is to convertthis zymogen into the active enzyme.Fibrinogen, prothrombin, and calcium are not, however, the onlythree agents which participate in the phenomenon; and it was thespecial feature of the theory of Morawitz that he assumed theexistence of an organic activator which has since received severalother names, but which is usually spoken of as thrombokinase.Much in the same way as the inactive trypsinogen of the freshlysecreted pancreatic juice requirN to be activated by the enter+kinase of the intestinal juice, so it is supposed that the thrombo-kinase acts in conjunction with calcium in the liberation ofthrombin from its mother substance prothrombin.Thrombokinaseor an analogous substance is also provided by the disintegrationof other tissues.It is well known that if blood when shed is allowedto come in contact with other tissues, such as the muscles andskin which are cut through, its coagulation is hastened. Evenalthough this is prevented by collecting the blood straight from anartery through a clean glass tube, it clots in time, and so thethrombokinase which is assumed to be necessary was furtherassumed to originate from the blood-corpuscles.Of the four fibrin factors, two therefore are present in the fluidpart of the blood, namely, fibrinogen and the calcium, and theother two (prothrombin and thrombokinase) are furnished by thecorpuscles, and especially by the blood-platelets.About this date, researchea on immunity were in full swing, andthe ideas current in that region of work were reflected in thetheories put forward concerning the action of enzymes generally.The matter was therefore complicated by the discovery of anti-enzymes. The special one in the blood which keeps it fluid underliving conditions was dubbed anti-thrombin, and according to someobservers, the assumption of an anti-kinase was also necessary.Whether the blood remained fluid, or set into a coagulum wastherefore the resultant of the action of opposing forces, some ofwhich favour the interaction of thrombin and fibrinogen, and othersof which inhibit that action.Quite a t an early stage in the development of these new ideasLeo Loeba put forward other views, especially in relation tothe part taken in the procetw by tissue extracts, and he consideredthat the coagulins of the tissues as he termed them were not merelyactivators, but entered into the actual process of fibrin-formation.An entirely new note in criticism was struck by Rettger, whoworked with Howell, and subsequently by Howell 31 himself.Theseobservers put forward grounds for believing that thrombin is not30 See Ann. Report, 1905, 180. [bid., 1910, 189238 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRS.an enzyme after all, for they found a definite quantitative relation-ship between the interacting substances, a fact which is not inaccord with the conception of the ferment-like character ofthrombin, and during last year H. Stromberg 32 supported Howell’sview. The idea that thrombin is not an enzyme has provoked muchreflection and criticism among physiologists, although, so far as Iknow, no one has yet got so far as to repel or even attack it inprint.A complicated question of this kind is not susceptible ofacademic discussion without facts to go upon, and facts take timein working out. So far, however, physiologists as a whole are notyet convinced, and still teach that thrombin is an enzyme. If infibrin formation we had only to deal with two reacting substances,thrombin and fibrinogen, the problem would be a simple one, andcould be easily settled, but when the factors are more numerous thedifficulties are increased. It is admitted by all that thrombokinaseunder one or other of its numerous aliases, whatever may be itsaction, is not an enzyme, and it may be that it was the action ofthis substance which complicated Howell’s results.The papers on the subject, published in the year 1912, havemainly emanated from Baltimore; thus Meek33 has taken up thequestion of seat of origin of fibrinogen.Dogs were bled, the bloodwhipped, and then re-injected minus its fibrin. The regeneration offibrinogen occurred with great rapidity, 100 per cent. increasebeing noted in three hours. If the liver was entirely excluded fromthe circulation, however, regeneration did not take place a t all, andthe small amount of fibrinogen left in the residual blood rapidlydisappeared. A hasty observer would have a t once jumped t o theconclusion that the liver itself forms fibrinogen, but experiencebreeds caution, and, as Dr.Meek states, there is still open anotherpossibility, namely, that the liver may influence the formation offibrinogen elsewhere by means of a hormone.The work of BayneJoness emphasises the importance of theblood-platelets in providing the corpuscular contribution to fibrinformation. He found in his experiments with platelets and puresolutions of fibrinogen that the former contain a substance, pro-thrombin, which after activation with calcium, clots fibrinogen.This is a confirmation of Morawitz’s views. He also found thatextracts of platelets cause the clotting of “peptone plasma,” a32 Biochem. Zeilsch., 1911, 37, 177 ; A,: ii, 59.33 Proc. Amer. physiol. SOC., 1911, xix, Amer. J. Yhysiol., 29 ; A., ii, 273.34 Amer. J.Physiol., 1912, 30, 74 ; A., i, 459. Cramer 2nd Pringle reached thesame conclusion by a different method, for they found that after removal of theplatelets by filtration through a nerkfeld filter from oxalate plasma, coagulationcan no longer be induced by the addition of calcium salts (PTOC. yliysiol. Soc., 1912,xi, J. Physiol., 45)PHYSIOLOGICAL CHEMISTRY. 239form of plasma which already contains thrombin, fibrinogen, andcalcium. The platelets are therefore the source of the fourthfactor, whi‘ch Morawitz would term thrombokinase, but whichBayne-Jones, using Howell’s nomenclature, prefers to call thrombo-plastin. H e explains the absence of clotting in peptone blood asdue to the presence of large amounts of anti-thrombin, and theaction of thromboplastin is t o neutralise the antithrombin.The question of antithrombin also is taken up by D.Davis.35 Hefound, as many have found before him, that injection of thrombininto the blood-stream within certain limits does not produce intra-vascular coagulation, and considers that the injection excites therapid formation of its antidote, the agent which normally preventsclotting during life.The general idea that thrombokinase is not an activating agent,but is the antagonist of antithrombin, is more fully advocated byHowe11,36 under whom both Davis and Cecil worked. Later in they e a r s he brought forward some more evidence in favour of thisview, and supplemented it by hazarding an opinion of the actualnature of thromboplastin. He considers that it is a phosphatideof a nature akin to kephalin.H e thus revives an old notionoriginally promulgated by Wooldridge many years ago. WhenWooldridge worked our knowledge of the phosphatides and lipoidsgenerally was very scanty, and the nucleo-proteins were almostunknown. When, therefore, Wooldridge spoke of lecithin as ahelp to blood-clotting, he exercised not only a tenable view of theprocess, but if Howell is correct he showed a truly propheticinstinct.Quite independently of Howell and his pupils, much the sameview has found favour with E. Zak.B He finds that a diminutionof the lipoids of the plasma leads to a delay in its coagulation, andthat the addition of phosphatides from other organs acts even morestrongly in hastening coagulation than those normally present inthe blood.Alkaloids which unite with lecithin are also inhibitoryto coagulation. Such results agree with the views of AlexanderSchmidt on zymoplastic substances, and if correct render theassumption of a, kinase in Morawitz’s sense unnecessary.We thus see that the problem of blood-clotting has entered on anew phase, and is in a more interesting condition than it has beenin for many years past.35 Amer. J. Physiol., 1911, 29, 160 ; A . , ii, 60. A papor prcceding this (ibid.,156 ; A., ii, 60) by Cecil contains many valuable hints for the purpose of obtaiuiiigand preserving pcptone plssnia and thromboplastic extracts.d(i Ibid., 187 ;A., ii, 60.38 Arch. expt. Path. Phnrm., 1912, 70, 27 ; A . , ii, 1065.37 Ibtd., 1912, 31, 1 ; A , , ii, 1078240 ANNUAL REPORTS ON TEE PROCIRESS OF CHEMISTRY.Oedema.The cedematous or dropsical condition is due to an abnormallylarge formation of lymph, the fluid which leaks from the blood asit passes through the thin-walled capillaries, and is thus an exag-geration of a normal process.It can be produced by an increaseof the capillary pressure, it9 when one ties a ligature around a, limbso as to obstruct the venous outflow. It can be also produced byan injury to the capillary epithelium, which renders the vessel wallsmore leaky. Another factor is doubtless a change in the blood,such as an increase in its water, or the development of poisonswhich, circulating in the blood, lessen the vitality of the capillarywalls, Carl Ludwig taught that increased lymph formation wasthe result of purely physical factors of this nature, and the sameposition has more recently been maintained by Starling.Heidenhainintroduced the so-called ‘‘ vital theory,” in which he bestowed uponthe living cells of the capillary wall a selective power which enablesthem actually to secrete lymph; he was further the inventor of theword lymphagogue (or lymph driver), which he applied to variouschemical agents, many of which he considered increased the lymphby stimulating the capillary cell to heightened secretory activity.Pathologists have for long wrangled over the question of therelative merits of the mechanical and vitalistic hypotheses, andthe mechanical theorists have differed according as to whetherpressure variations, cell-permeability, or blood changes such a.eihydmmia are the more potent in the causation of the condition.Non-partisan onlookers have agreed that in different cases thesevarious factors may have different values, and although most exhibitscepticism regarding Heidenhain’s extreme views, they are never-theless quite open to conviction that the cells may possibly exercise,thin though they are, a certain amount of selective action.In 1910, however, Martin Fischer, of California, published abook 39 which rather fluttered the dovecotes of the pathologists, forit denied that any of the factors mentioned were of any real conse-quence a t all, or, a t any rate, were quite insignificant in comparisonwith a new power which he considered his experiments taught himwm the main motive force in attracting fluid from the blood intothe tissues.He found by experiments on various colloids thatacidity caused them to swell more when immersed in watery fluidsthan when the reaction was neutral. Dead frog’s legs which hadbecome acid similarly absorbed more water; and put in baresta9 “CEdema,” S. Wiley and Sons, New York. See also Zciklch. Chem. Itid.Kolloide, 1911, 8, 159 ; d., 1911, ii, 309 ; Koll. Chcm Beihefte, 1911, 2, 304 ; A , ,1911, ii, 610PHYSIOLOGICAL CHEMISTRY‘. 241outline his theory of edema is that increase in the acidity of thetissues which is the result of many pathological processes causesby osmotic pressure water to be drawn from the neighbouring blood-stream. I think physiologists all felt when they read Fischer’svery clear and well-argued statements that here, at any rate, wasa new light on what is certainly a puzzling problem, but theywere not prepared to accept fully the sweeping conclusions he drew.A palpably weak point that immediately attracted notice was theadmission that an alkaline reaction was almost as potent as anacid one in promoting the swelling of colloids; and I fancy manyfelt that the experimental data, were hardly sufficient to supportall his contentions. During the present year several papers haveappeared which contest the new views; for instance, Pincussohn 40found that many tissues behave exactly in the contrary waytowards acid from what Fischer found. Gelatin, muscle, andcartilage swell more in acid, but liver, spleen, kidney, and lungdo not. It is quite evident that a rule which is not universallytrue cannot be of prime importance. A. R. Moore41 is still morepositive that Fischer is incorrect. Gies 42 severely criticises thetheory, while he does not deny the possibility that tissue changesmay have an influence; he takes the view that protein cleavageproducts, the result of the action of tissue proteases, may baefficient water attractors, but admits that up till now this has notbeen proved. Fischer 43 has defended his views, but the attackupon them has been sufficiently serious to make physiologistsdoubtful whether they can be accepted without very considerablereserve.I take the present opportunity of correcting a slip that occurredin my report of last year. Speaking of acapniu, I stated that theword had been introduced by Dr. Yandell Henderson. Dr. Hender-son has certainly made the word familiar, but as has been pointedont to me, he did not himself coin it. The late Professor AngeloMOSSO, of Turin, was the author of the word; in his “Life on theHigh Alps ” (1898) he says : “ As the ancients were not acquaintedwith carbonic acid, and had therefore no name for it, I chose theword smoke as most resembling it in a physiological sense, and socoined the word ‘ acapnia,’ which means without smoke.”W. D. HALLIBURTON.JO Zeitsch. expt. Path. Ther., 1912, 10, 308 ; A., ii, 666.41 Pflilger’s Archiv, 1912, 147, 28 ; A , , ii, 856.42 Biochem. BuZl., 1912, 1, 461 ; A., ii, 856 ; Ibid., 540 ; d., ii, 1080.43 Zeitsch. Chm. Ind. Kolloide, 1912, 10, 283 ; A . , ii, 784 ; Biochem. Bull.,1912, 1, 441 ; A., ii, 856.REP.-VOL. IX.

ISSN:0365-6217    

DOI:10.1039/AR9120900221

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

AGRICULTURAL CHEMISTRY AND VEGETABLEPHYSIOLOGY.THE year 1912 represents a period of steady progress without anyremarkable discovery or new advance to make the date memorablein the history of the science. It is perhaps hardly to be expectedthat any wide new generalisation can be attained for some timeto come. The first approximations to the truth have already beenmade, and we are a t present realising the inadequacy of theanalytical methods available to solve the very intricate questionsinvolved in all living processes. I n every direction, in thechemistry of the soil, in the nutrition of the plant and of theanimal, evidence is accumulating of the powerful effects of tracesof this or that constituent, traces which are both minute anddiEcult to identify in the complexes of which living tissue iscomposed.Perhaps the most striking example is afforded by recentwork in animal nutrition. The older investigators were concernedwith the broad quantitative facts concerning the utilisation of food-proteins to repair nitrogenous waste-carbohydrates, and fatsas sources of energy. It has now been shown, however, that ananimal may be supplied with a diet perfectly balanced from thispoint of view, pure proteins, carbohydrates, fat, and salts inadequate quantities, and will yet fail to grow or even to thriveunless a minute trace of some materials directly derived from livingorganisms, such as meat extract, milk, or fresh vegetables, is given.The amount of the latter constituent involved do not enter into thequantitative statement of the food supplied and utilised, yet theyare indispensable to the well-being of the animal.Again, in discuss-ing the chemical processes taking place in the plant, we mustadmit that we can follow no one of them accurately because of theimperfection of our analytical methods. The funda.menta1 functionof the plant is photo-synthesis and the subsequent migration andstorage of the carbohydrates produced thereby; in order to followthe sequence of this process it is necessary to estimate with accuracythe constituents of a mixture containing five- and six-carbon sugars,bioses, starch, and other carbohydrates approximating to starch,all in dilute solution and liable to change from the presence of24AGRICULTURAL CHEMfSTRY AND VEGETABLE PHYSlOLOGP.243enzymes, masked also by the presence of nitrogenous substances ofvarious stages of complexity. Until analytical methods have beenworked out capable of dealing with such complexes as this, andwith reasonable rapidity, we can neither follow the developmentof the plant nor reason about such practical aspects as its qualityor food value.Soil Chemistry.The question of the increased fertility of soils that is producedby heating to the temperature of boiling water or exposure for atime to the vapour of antiseptics haa continued to occupy theattention of investigators in all parts of the world. Russell andHutchinson have so far published no further communicationregarding their theory of the source of the increased productivity,namely, that i t is due to the destruction of a factor that inhibitsthe free development of the bacteria reducing the compounds ofnitrogen present in the soil to the state of ammonia, which factorconsists in certain forms of protozoa inhabiting normal soil; butnone of the other investigations invalidates their theory.Russell,in collaboration with F. R. Petherbridge,l has published an accountof experiments on the treatment of greenhouse soils on a com-mercial scale both by heating with steam and by the addition ofvarious antiseptics. I n the rich composts employed by marketgardeners under glass, which are constantly maintained in a verymoist condition and a t high temperatures, deterioration sets inafter a few years, and the soil has to be changed, although analysiswould still show it to be rich in all the elements of plant food.The conditions are obviously such as would favour the developmentof protozoa, but nematodes and other parasitic organisms alsoincrease abnormally and are affected by the treatment just like thsprotozoa.The authors found that such greenhouse sick soil canreadily be restored to its former condition and made even moreproductive by steam heating or by the addition of small quantitiesof various antiseptics, of which formaldehyde is the most practicallyeffective. Methods have been worked out which are commerciallyremunerative, and many of the market gardeners growing tomatoesand cucumbers are now partly sterilising their used soils as amatter of business routine.The question, however, calls for muchmore investigation, as heating t o such temperatures as loooproduces substances which persist in the soil f o r a time and areinjurious to seedlings and the earlier stages of certain plants,although not to others. The foimation, however, of these injuriousbodies is most irregular, and the results cannot as yet be predictedwith any particular soil.J. Board AgriczlEture, 1912, 18, 1923 ; 19, 809.I244 ANNUAL REPORTS ON THE PROGEESS OF CHEMISTRY.0. Schreiner and E. C. Lathropz have isolated some of thesesoluble substances that are formed in steam-heated soils. Theytook two soils of the same type, one poor and the other rich. Fromthe poor soil they obtained dihydroxystearic acid and various decom-position products of nucleic acid, namely, xanthine, hypoxanthine,guanine, cytosine, arginine, all of which substances were increasedin amount by the heating process.In the rich soil they were notpresent at the outset, but were produced by heating. The nitrogencompounds may serve as food for plants and add to the value ofthe soil, but this value is overbalanced by the detrimental effectsof the dihydroxystearic acid, which must be removed before thebenefit of steaming is realised. E. C. Lathrop, in another com-munication,3 explains his method of isolating guanine, which hasso far only been found in heated soils, probably because i t is sosubject to destruction by the micro-organisms, etc., present innormal soil. Among the most effective compounds examined byRussell and Petherbridge was calcium sulphide, to which they areinclined to attribute the fertilising value of the old form of “gaslime ” known as “ Blue Billy,” and E.Boullanger 4 finds the additionof flowers of sulphur increases the fertility of the soil. As thisincrease is not obtained with soil that has been sterilised, Boullangerconcludes that the action of the sulphur must be in some wayconcerned with the living organisms of the soil. In a furtherpaper,Q he attributes to the sulphur an activating effect upon theorganisms breaking down the insoluble nitrogen Compounds of thesoil, because only small doses are effective, further additionsreducing the fertility of the soil below the normal. A. DemolonGconsiders that the presence of free sulphur in crude ammoniumsalts from the gas works explains the manurial efficiency of thesecompounds, which is greater than can be attributed to the nitrogenalone that they contain.It would hardly seem, however, that anyvery trustworthy evidence has been produced of the activatioFofbacteria by non-nutritive substances. The whole question ofso-called “ catalytic ” stimulus of either lower organisms or plantsis still enveloped in doubt as to the facts to be explained.It is satisfactory to note that considerably increased attention isbeing paid to liming soils both in practice and in the investigationof the effects of lime on the chemical and bacteriological changesin the soil. A t one time among the most widespread of farmingoperations, liming and chalking fell into disuse with the rise inJ.Amer. Che?n. Soc., 1912:34, 1242; A., ii, 981.Ibid., 1260 ; A., ii, 982.Contpt. r e d . , 1912, 154, 369 ; A., ii, 381.With M. Dugardin, ibid., 155, 327; A., ii, 971.Cmpt. rend., 1912, 154, 524; A., ii, 382AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 245the cost of labour and the introduction of artificial manures, andit is only recently that their value, indeed necessity, on many soilsis beginning again to be recognised. In two extensive papers,0. Lemmermann, A. Einecke, and H. Fischer7 discuss the effect oflime and magnesia in various ratios on the bacterial content andactivity of the soil, and the effects that may be observed on plantsarising from either the presence or the lack of this constituent.P.E. Brown8 discusses the effect of applications of ground lime-stone up to the rate of three tons per acre on the Wisconsinexperimental plots. He finds that the base increased the numberof bacteria present in the soil; a t the same time its ammonia-making, nitrifying, and nitrogen-fixing powers had all been raised.As might be expected, the crop-producing powers of the soil hadbeen raised pari passu.E. BlanckQ has examined the laterite soils of the tropics andcompared them with the red soils of temperate countries, such asthose derived from the Permian and the Triassic formations. Hisanalysis would point to considerable similarity between the twosets of soils, although the surface of the laterite soils in proportionto the amount of silica and alumina they contain is greater,because the sesquioxides are partly in a colloidal state.D. J.Hissink10 points out that Blanck's analyses indicate a muchhigher ratio of alumina to silica in the laterite than in the redsoils, van Bemmelen having previously noted the high proportionof free alumina as a characteristic of laterite soils.As regards the study of soils in situ a survey of the soils andagriculture of Shropshire has been published by G. W. Robinson,lland contains a number of analyses, chemical and physical, of soilsderived from the Old Red Sandstone, the Wenlock Shale andother Silurian rocks, and from the Bunter and Keuper. A. D. Ha11and E. J. Russelllz report studies of the composition of the soiland of the grass growing on them of certain fields in RomneyMarsh, where some fields are capable of fattening six or eightsheep to the acre in the summer months, whereas the, land along-side, however lightly stocked, will only maintain the sheep in agrowing condition.Three pairs of such fields were studied, butdespite the great differences in their productivity, the ordinarymethods of analysis, mechanical and chemical, did not reveal anymarked causal factor which would differentiate between them. I nLandw. Jahrb., 1911, do, 174, 255 ; A , , ii, 198.Centr. Baht. Par., 1912, ii, 34, 148 ; 35, 234 ; A., ii, 670.J. Zandw., 1913, 60, 59; A., ii, 482.Ibid., 237 ; A., ii, 981.Published at Shrewsbury.J. Agric. Sci., 1912, 4, 339246 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.each pair the soil of the good and the bad field, althoughdiffering in type in the three cases studied, was similar withinthe limits of error of the method, the water content andtemperature throughout the growing season were also similar, andthe herbage neither botanically nor chemically could be distin-guished.The only constant and significant differences found werethat the good soils were slightly higher from the permanent watertable, more permeable to water, and richer in phosphoric acid,although the poorer soils could not be regarded under ordinarystandards as deficient in this constituent. The soils of the goodfields were also more active, their oxidising power and the rate a twhich they produced nitrates and ammonia were greater.Theherbage was characteristically more leafy and less steinmy on thegood fields, but the proportions of fibre and of nitrogen compounds-protein, non-protein, and digestible-revealed no significantdifferences. The general conclusions reached by the authors werethat our existing methods of analysis, both of soils and of fodder,are not refined enough to discriminate between good or bad incases of this kind.Bacteriology.One of the most important processes in the bacteriology of soilconstituents has hitherto received remarkably little attention,despite the fact that it plays a considerable part in other industrialprocesses. We refer to the fermentation of cellulose and otherinsoluble carbohydrates found in plant tissues.The broad factsthat such substances are rapidly oxidised in soil to carbon dioxide,and that humus, methane and hydrogen are possible by-products,have long been familiar, as also that the degradation process is abiological one, but the investigations of the agencies are few andincomplete. Omelianski has described two organisms which workunder anzerobic conditions and in addition to carbon dioxide, fattyacids and humus produce, the one methane, the other hydrogen,but few other investigators have continued on this line of research.K. F. Kellerman and L. G. McBeth13 have now published a pre-liminary account of a fresh attack on the cellulose organisms, whichalready leads us t o revise our conclusions on the subject, and bringsthem much more in accord with field experience.Unable to isolateorganisms agreeing with those described by Omelianski, theyobtained from him preparations of the bacteria he had described,and were able to isolate two distinct cellulose ferments from themethane-f orming, and one from the hydrogen-forming, pre-paration. All three, however, proved to be only facultativel3 Centr. Bakt. Par., 1912, ii, 341, 485AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 247anaerobes, which oxidised cellulose most readily in the presence ofoxygen. I n no case, however, did the pure culture of the organismgive rise to gas; both the methane and the hydrogen were liberatedby contaminating organisms from the products of the degradationof the cellulose.These investigators also succeeded in isolatingfrom soil eleven other organisms attacking cellulose, one of whichbelonged t o the thermophilic group. All these acted as facultativeanaxobes, and none of them gave rise to gas. Large numbers offungi were also found to have the power of dealing with cellulose.With the above exception, bacteriological investigation seemslatterly to be concerned more with the soil as a whole, with theactivity of groups of organisms bringing about a particular change,than with the work of particular organisms isolated under laboratoryconditions. The view that the ammonia-making bacteria in themain determine the formation of available nitrogen compounds,and in consequence the fertility of the soil, is gaining ground, andis strengthened by several of the researches that have been pub-lished during the year.It was long held that the higher plantscould only take up nitrogen from the soil in the form of nitrate,and after the discovery of the nitrifying organisms, it becamecustomary to regard the rate of nitrification in the soil a8 thelimiting factor in supplying the crop with nitrogen. As, however,the amount of ammonia in the soil never increases beyond verylow limits unless the nitrification organisms have been killed offby one of the processes of partial sterilisation, it becomes evidentthat nitrification normally goes on as fast as ammonia can besupplied, and that the limiting factor is the rate a t which theorganisms splitting off ammonia from the nitrogenous reaidues dotheir work, rather than the activity of the further group whichconverts ammonia into nitrates.Other evidence has shown that thenutrition of the plant by ammonia instead of nitrates takes placeto a considerable extent in the field, and is not a matter of abnormallaboratory conditions. In this connexion attention may be drawnto a paper by P. E. Brown and R. S. Smith,l4 who have beeninvestigating the bacterial activity of the soil a t different seasonsof the year, and especially after freezing has taken place. I nautumn, the number of bacteria diminishes with the fall of tem-perature, but rises again rapidly after freezing has taken place.The ammonia-making, the nitrifying, the nitrogen-fixing, and thedenitrifying power of the soil all show the same sequence, but therise of activity is most marked in the ammonia-making power.Theauthors conclude that the increase in the numbers of bacteria musttake place when the soil is frozen, but they do not seem to havel4 Centr. Bakt. Par., 1912, ii, 34, 369248 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.considered whether it may not follow very quickly on a liberationof soluble food brought about by the freezing. In dealing withplants, we have evidence that processes like freezing, by alteringthe water content of the cells, brings enzymes into play and startsor speeds up many actions which result in soluble products leavingthe cell, and by analogy one may well expect something of the samekind to take pIace in the soil, just as exposure to chloroformvapour increases the soluble constituents that can be obtained fromthe soil.P.E. Brown15 has also traced the effect of the rotation of cropson the bacterial state of the soil. He found a larger bacterialcontent and increased activity in ammonia making, nitrificationand nitrogen fixing, in soil that had been under a rotation ascompared with soil that had been continuously cropped with oneplant. The soil of plots under a long rotation again gave betterresults than that of land under a short rotation of two or threecrops only. Curiously enough, where a green crop had beenturned in there was sometimes a decrease in the nitrogen content,but this the author is inclined to attribute to the reduction of themoisture brought about by the growth and ploughing in of thegreen crop.These facts must be considered in connexion withrecent theories on the cause of the benefits due to rotations.Another interesting field study of the bacterial changes in soilis reported by R. Stewart and J. E. Greaves,lG who for some yearshave been determining the nitrates in a rich soil well suppliedwith calcium carbonate under irrigation in California. They foundthat the irrigation water increased the production of nitrates, butthe smaller quantities of water were more effective than the largerapplications. Again, the amount of nitrate varied very markedlywith the depth, and successive layers of soil, although thoroughlymoist, could contain very different proportions of nitrate.A zonerich in nitrate could be made to rise or fall in the soil, but apartfrom these vertical movements there was little or no diffusion, andno evidence that any soil solution of approximately uniform com-position, as postulated by Whitney and Cameron, was ever formed.Different crops had very varied powers of seizing on the nitrateswhen formed; lucerne (alfalfa) and oats always kept the pro-portion of nitrates and the concentration of the soil solution verylow as compared with potatoes and maize. In spring the nitratecontent of the cropped soil was higher than that of the fallow;in autumn the reverse was true, as had previously been observedby Warington and King. Vogell? has been considering thel6 Cent?.. Bakt. Par., 1912, ii, 35, 234.Ibid., 3$;115.l7 Ibid., 540 ; A., ii, 1089, 1206AGRICULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 249destruction of nitrates in the light of certain experiments in whichthe soil was placed in shallow layers in porcelain vessels. The soilcontained 15 to 20 per cent. of water, but although no freshorganic matter was present, great losses of nitrates were expe-rienced up to 60 per cent. within ten days. The reduction seemsto depend on the exclusion of air by the moisture in the littleaggregates of soil. The author suspects some purely chemicalreduction of nitrate, but the evidence against biological action doesnot seem very strong.C. B. Lipman and L. T. Sharp18 have investigated the toxiceffects of various substances, chloride, sulphate, and carbonate ofsodium, found in alkali soils, on the activity of the ammonia-forming, nitrifying, and nitrogen-fixing organisms.The nitrogen-fixing organisms, unlike those causing nitrification, are resistantto comparatively high concentrations of sodium chloride andsulphate, hence the abnormal accumiilation of nitrates observedby Headden and Sackettlg might still be due t o bacterial action.The explanation advanced that the accumulation was due to excep-tional fixation of nitrogen by A zotobacter had been criticised, notonly on the score of the absence of carbohydrate as a source ofenergy for the nitrogen fixation, but also on the ground that thechlorine in the soils increased with the nitrate to such an extentas would inhibit bacterial action, a correlation which would alsoindicate leaching and seepage as the source of both salts.J.Stoklasa 20 has studied the biological absorption of variousmanure constituents when added to soils. When solutions ofsoluble phosphates, potash, ammonia salts or nitrates are allowedto percolate through the same soil, sterilised in the one case andnot in the other, €here is always considerably greater removal ofthe fertilising constituent by the unsterilised than by the sterilisedsoil. The bacteria either utilise the material in growth and multi-plication, or arrest it in some way by temporary adsorption.Stoklasa regards the amount of absorption as proportional to thenumber of bacteria in the soil, and proposes to take it as a measureof the bacterial content, and therefore of the fertility of soil.A.Duschetschkin 21 also demonstrates the biological precipitationof phosphoric acid when solutions are placed in contact with ablack soil enriched with starch. If the soil is first sterilised, thephosphoric acid remains soluble.l8 Centr. Bakt. Par., 1911, ii, 32, 58 ; 1912, 33, 305 ; 35, 647 ; A., ii, 76, 473,l9 Ann. Report, 1911, 222; Sackett, Centr. Bakt. Par., 1912, ii, %, 81. ; A., ii,2e Chem. Zeit., 1911, 35, 1425 ; A., ii, 198.21 J. E q . Landw., 1911, 666 ; A., ii, 677.1200.670250 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Chemistry o f Plant Nutrition.It is now somewhat generally agreed that formaldehyde con-stitutes one of the early steps in the photosynthetic process wherebycarbon dioxide and water are converted into carbohydrates andoxygen.The difficulty is to isolate the formaldehyde amid themany other substances present in the green leaf. T. Curtius andH. Franzen 2 distilled large quantities of green hornbeam leaveswith water, and were able to identify very small amounts offormaldehyde in the distillate. Other green leaves when distilledalso gave positive results. They were able to isolate Aa-hexen-aldehyde from the distillate. The presence of this substance mustalso be connected with carbon dioxide assimilation, because it wasnot obtained from the same leaves if they had been kept protectedfrom the light for some time before gathering and distillation.I. Pouget and D. Chouchaks have repeated some of the earlierwater-culture experiments on the effect of the concentration ofthe nutrient solution on the growth of the plant.For each of thecritical constituents, nitrate. phosphate, and potash, they f ou udthat a t very low dilutions (for example, 0.1 milligram of P,O, perlitre) the plant gives out, and does not absorb, the constituent.As the concentration increases the absorption increases y o rntnuntil a point is reached when the absorption is exactly proportionalto the concentration of the nutrient solution. A further point isreached later when the absorption becomes less than indicated bythe increased concentration, because it is then determined by thecapacity of the plant to assimilate the material taken in. Otherunpublished experiments in England would confirm the main con-clusion of the authors that within certain limits the absorption ofthe nutrient materials and the consequent growth of the plant isproportional to the concentration of the solution, even when pre-sented to the roots in unlimited amounts.These facts afford somz-what cogent arguments against Whitney and Cameron’s soil solutiontheory, according to which the concentration of the soil water insuch constituents as phosphoric acid and potash is a matter of noaccount in the nutrition of the plant, because it can fully supplyits requirements from a solution of extreme dilution, far belowany that would be formed naturally even in the poorest soils.The method of water culture is, however, full of pitfalls, andexperiments require to be repeated in large numbers and interpretedwith great caution.E.Ramann% has continued his studies of the migration of i*ood22 Ber., 1912, 45, 1715; Annulen, 1912, 390, 89; A , , ii, 797, 978.23 Compt. rend. , 1912, 154, 1709 ; 155, 303 ; A . ) ii, 796, 975.Landw. Yersuchs. $tat., 1912, 76, 157, 165 ; A., ii, 378AGRlCULTURAL CHEMISTRY AND VEGETABLE PHYSIOLOGY. 251substances from the leaves of trees prior to the autumnal fail.He finds that the migration chiefly takes place during the com-paratively short period after the leaves have begun to changecolour. Then a considerable proportion, in some cases amountingt o one-half, of the nitrogen and phosphoric acid are returned t othe permanent parts of the tree, calcium compounds and silicataking their place. If the leaves are killed by frost before’thsyhave yellowed off and died naturally, the migration process isstopped, and the nitrogen, a t any rate, remains in the leaves.Theanalyses indicate, strangely enough, that in such cases the frozanleaves lose their potash and phosphoric acid in a few hours afterthawing, although no rain has taken place, but such a conclusionrequires further experimental support.The question of migration also enters into the practical problemof determining the optimum time a t which to cut the hay crop,which has again been taken up by C. Crowther and A. G. R U S L O ~ . ~ ~They cut “seeds” hay on four dates separated by approximatelyfortnightly intervals, and determined the total weight of the crop,its composition, and digestibility, as far as was possible by labora-tory methods.The dry matter and the true protein per acreincreased the later the cutting, but the “amides” decreased inpercentage and finally in absolute amount. The fibre and pentosansincreased both relatively and absolutely; the soluble carbohydratesshowed some absolute decrease in the latter two cuttings. Thevalue of the food produced per acre, either for maintenance orproduction, reached its maximum a t the third cutting, and thenfell off, but the results would indicate that a fair amount oflatitude may be allowed in the date of cutting without causingappreciable loss. It would be desirable to have these resultsrepeated on a larger scale, and accompanied by real digestionexperiments.The effect of traces of various metals on the growth of plantscontinues to be a subject of considerable investigation, especiallyin France, where the labours of G.Bertrand and his colleagueshave considerably advanced the question, especially in connexionwith manganese. Several recent papers 26 deal with the dependenceof Aspergillus niger on manganese and zinc in the nutrient sub-stratum. The conclusions are somewhat remarkable-that suchminute traces of manganese as one in ten thousand million havean appreciable effect in increasing the yield of Aspergillus, althoughgreat precautions have to be taken to free the materials frommanganese in order to realise this result experimentally. Again,25 J.Agm’c. Sci., 1912, 4, 305.36 G. Bertrand, Compt. rend., 1912, IM, 381, 616 ; M. Javillier, i b i d . , 383 ; A.,ii, 377252 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.in the absence of manganese, the fungus will not give rise toconidia; moreover, minute traces of iron and zinc must also bepresent before the conidia will form. A minute trace of zinc mustalso be present in the medium to enable the invertase present inthe cells of Aspergillus niqer to act; in its absence the invertasedoes not diffuse through the cell waII.The employment of manganese and other so-called ‘ I catalytic ”manures on a field scale does not make much headway. T. Pfeifferand E. Blanckfl report a number of experiments both in potsand with trial plots in the field.The results are not conclusive,however, only in so far as they indicate that the magnitude ofthe effect produced by the manganese, if any, is not of practicalimpor’tance. A. J. Brown and F. P. Worley28 have continuedtheir investigation into the extremely interesting semi-permeablemembrane they discovered enveloping the endosperm of barley.They now find that the rate of absorption of water by the barleyseeds a t different temperatures is an exponential function of thetemperature. This leads to a discussion of the constitution of waterthat would agree with such a result, from which the authorsconclude that only the simple molecules are transmitted by thedifferentia1 septum and assimilated by the starch within. Thisconclusion is confirmed by the measurements obtained for the waterabsorbed from a solution of ethyl acetate, which agree with theresults obtained for pure water, except for a possible slight associa-tive effect of the ethyl acetate on the water molecules.Chemistry of Animal Xutrition.29The most notable example of the effect of certain substancesexisting in food in minute traces only is afforded by the numerousinvestigations that have led to the discovery of the source of thedisease of malnutrition well known in the East under the nameof “beri-beri,” which has been shown to be identical with a stateof polyneuritis that can be induced artificially in fowls a d otheranimals.Beri-beri is prevalent in rice-eating communities, andvarious theories have been previously advanced to explain its origin ;for example, it has been associated with a fungus attacking ricethat is stored and allowed to become mouldy, and, again, it hasbeen attributed to the incomplete nature of the proteins containedin rice.It was noticed that many rice-eating communities, oftenof the poorest character, were free from the disease, whereas othersconsuming purchased rice of presumably good quality developed21 Landw. Versuchv. Stat., 1912, 77, 33 ; A., ii, 476.28 Proc. Roy. SOC., 1912, B, 85, 546 ; A., ii, 1086.29 See also pp. 228 et seqAGRICULTURAL CHEMlSTRY AA’D VEGETABLE PHYSIOLOGY. 253cases of the disease. The next step was the observation that fowlsfed on decorticafed or polished rice pine away and contract adisease of polyneuritis similar to and presumably identical withberi-beri.30 If, however, the fowls are fed on whole rice just asit is threshed, they remain healthy; the same diet, also, willinduce recovery from the disease induced by the decorticatedmaterial. A t this stage several lines of investigation coincide.U.Suzuki, T. Shimamura, and S. Odake31 proceeded to attackthe husk or the polishings removed in the process of preparingrice for market. These investigators satisfied themselves that thesubstance inhibiting the disease could be extracted from the husksby water or alcohol. Finally, by dealing with the alcoholic extractof the fat-free husks, they were able to prepare an alkaloidalsubstance containing nitrogen, to which the name of oryzanin hasbeen given.Small quantities of this substance will keep animalsfree from the disease that follows feeding on materials in whichit is lacking; for example, dogs fed on boiled meat and huskedrice after three or four weeks completely waste away and die ifthe diet is persisted in. The addition to the daily ration of 0.3gram of oryzanin, however, brings about a rapid recovery. Thesame investigators were able to show that the same substance, orone analogous in its effects, could be isolated from extracts of wheatand barley bran, from bread, from oats, cabbages, and othernatural foods. Similar experiments have been reported with wheatbran; the white flour from the interior of the endosperm has incertain cases proved incapable of maintaining growth, although itwas thoroughly utilised on the addition of a small quantity of thebran or its extract.To test the applicability of these facts to thenutrition of man on white or on so-called (‘ standard ” bread, L. F.Newman, G. W. Robinson, E. T. Halnan, and H. A. D. N e ~ i l l e 3 ~made experiments on themselves, each trial of one or other breadlasting a week. On the whole, absorption of the nutrients was veryuniform; from white bread about 34 per cent. more protein wasabsorbed, whilst ‘‘ standard ” bread contained rather morephosphates, which were equally well absorbed. When whole-mealbread containing more of the husk was fed, the absorption both ofnitrogen and phosphorus compounds was less. There was noevidence of any effect due to the specific cortex compounds, norcould the usual claims made for “standard” bread be substan-tiated.Indeed, the differences indicated possess no practicalimportance except when bread becomes the chief, almost the only,article of diet.30 See also L. BrBandat, J. Pharm. Chim., 1911, [vii], 4, 447 ; A., ii, 64. ‘‘ Biochein. Zeilsch., 1912, 43, 89 ; A., ii, 980.32 J. Hygiene, 1912, 12, 119 ; A., ii, 658254 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The capacity of a given food to bring about live weight increasemust, however, be distinguished from the power of merely main-taining equilibrium without growth, and this, as regards theproteins, is well brought out in several American investigations.For example, E. V. McCollums fed pigs with the so-called incom-plete proteins, zein and gelatin. For maintenance purposes,to repair the daily wear and tear of nitrogenous tissue, thepigs could utilise these proteins very effectively, up to 80 percent. with zein and 60 per cent. with gelatin, but for growth andthe formation of additional body tissue they possessed much lowervalue. The author therefore insists on the distinction betweenthe prohins required for growth and those needed for maintenanceonly.The discussion on the utilisation of the various nitrogen com-pounds can be paralleled by the question of the form in whichphosphorus compounds must be present in the food in order to beutilised. Most plants contain organic phosphorus compounds, andthe question is whether such substances are necessary to the animalor can be replaced by inorganic phosphates. Experimenting withgoats, Fingerling 34 finds that deficiency of organic phosphortlscompounds 3n fodder can be repaired by the addition of calciumand other inorganic phosphates. The matter is of some practicalimportance in the feeding of milch cows and young stock, certaindiets being deficient in ash containing phosphates.A. D. HALL.33 Amer. J. Ph,ysiol., 1911, 20, 215 ; A., ii, 63.34 Riochem. Zritscih., 1912, 39, 239 ; A . , ii, 465

ISSN:0365-6217    

DOI:10.1039/AR9120900242

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

MINERALOGICAL CHEMISTRY.THE year 1912 has not been productive of any remarkable advancesin the field of pure Mineralogy. A number of new minerals havebeen dmcribed, but few of them can be regarded as species of anygreat interest or importance; and although many analyses of well-known minerals have been published, the majority of these havebeen made for purposes of identification, and have thrown but littlelight on vexed questions of mineral composition with the notableexception of the work on tourmaline and nephelite, which we oweto American investigators.On the other hand, in the domain of theory, speculation has beenrife, and we shall have to notice some interesting suggestions as tothe possible constitution of the silicates.In the borderland where Chemistry, Physics, and Mineralogymeet considerable activity has prevailed ; thus the investigation ofbinary mixtures by thermal methods has attracted many workers,and some very important attempts to elucidate mineral formationhave been successfully carried out by synthetical methods in theGeophysical Laboratory a t Washington.I n the domain of chemical crystallography, Fedoroff has provedthat the system of classification a t which he has laboured so per-sistently affords us the means of readily identifying by its crystalform alone, any substance of which measurements have beenrecorded.Lastly, we must not omit to call attention to the publicationby the German Mineralogical Society of volume I1 of their usefulsummary entitled (‘ Fortschritte der Mineralogie, Kristallographieund Petrographie.”We will now proceed to a brief survey of the progress made inthese various directions, and will follow in the main the method oftreatment adopted in previous years.General and Physical Chemistry of Minerah.Silicate Fusions.-There has been an increasing tendency of lateto apply thermal methods to the study of many systems other than25256 ANNUAL REPORTS ON THE PROGRESS QF CHEMISTRY.those composed of silicates, and this is perhaps the reason why thereare this year but few researches in the silicate group which call forspecial comment.Among the most important of these is aninvestigation into the mutual relations of the compoundsCaAI,Si,O, and Na,AI,S~O,, carried out in the Geophysical Labora-tory a t Washington.1 It has already been shown that the former,anorthite, can readily be synthesised by fusing together calciumcarbonate, alumina, and silica.It has now been ascertained thatthe latter exists in two crystalline forms; one stable a t temperaturesbelow 1248O (about) is hexagonal, and may be termed soda-nephelite; the other, or higher temperature form, is anorthic, andis called soda-anorthite or carnegieite.Both forms can be obtained by fusing together sodium carbonate,alumina, and silica in the proper proportions, care being taken toavoid loss of soda by too vigorous heating, for if this occurs, crystalsof corundum appear in the product. Neither of these substanceshas been found in nature, although they enter into the compositionof nephelite and of certain plagioclase felspars.Crystals of soda-nephelite sufficiently large for study were obtained by crystallisa-tion from sodium tungstate. On studying the cooling curves andthe products obtained by quenching various mixtures of thesecompounds after they had been heated to definite temperatures fora sufficient length of time, it was found that soda-nephelite andanorthite form mixed crystals with a maximum content of 35 percent. of the latter substance, corresponding with the presence of7 per cent. of lime. Carnegieite, on the other hand, will only takeup at the most 5 per cent. of anorthite. As the proportion ofanorthite increases the birefringence of the nephelite diminishes,and when 23 per cent. of anorthite has been added the originallynegative crystals become isotropic, On further addition of anorthitethe crystals become positive.An investigation into the nature of Portland-cement clinker,involving the study of the ternary system limealumina-dica, wasreferred t o last year.In the course of the work evidence wasobtained which went to show that 8CaO,A1,O3,2Si0,, the ternarycompound obtained by Janecke, was really a mixture.2 The latter,however, states that melts of the above composition show a verysharp arrest on the cooling curve, and that under the microscopethin sections of the product are seen to consist of perfectly uniformcrystals with only small enclosures of glass.8A certain number of fusion experiments have also been made onN.L. Bowen, Amer. J. Sci., 1912, [iv], 33, 551; A., ii, 774.G. A. Rankin and F. E. Wright, Zeitsch. anorg. Chm., 1912, 75, 63 ; A . , ii,E. Jamecke, ibid., 76, 357 ; A., ii, 761.554MINERALOGICAL CHEMISTRY. 257natural minerals4; thus olivine (m. p. 1600°) and diopside (m. p.1363O) gave a eutectic a t 1271O containing 40 mol. per cent. ofolivine. Wollastonite and anorthite gave a eutectic containing30 mol. per cent. anorthite a t 1285O. Aegirite and anorthite gavea plagioclase f elspar intermediate between andesite and labradorite,together with the original components.A number of binary mixtures of meta-silicates of calcium, mag-nesium, iron, and manganese, both natural and artificial, have alsobeen examined, and the opt.ica1 properties of the solidified meltsdescribed in detail.5 The products include rhombic pyroxenes,diopside, choenstatite, wollastonite, and hexagonal calcium silicate.The work of Cooper, Shaw, and Loomis on the binary systemsilica-lead cxide, established the existence of the compoundsZPbO,SiO, and PbO,SiO,, and evidence was also obtained by others 6of the probable existence of 3Pb0,2Si02 and 3PbO,SiO,.Cooper,Kraus, and Klein7 have confirmed the presence of the first threecompounds in the melts, and have shown that the optical propertiesof the second and third are identical with those of the mineralsalamosite 8 and barysilite respectively.S d p h i d e Fusions.-A number of binary systems composed ofsulphides have also been subjected to thermal analysis.From themineralogical point of view the results obtained by F. M. Jaegerand H. S. van Kloosterg in their study of the thioantimonites andthioarsenites are perhaps the most important. When antimony andsulphur are melted together the only compound produced is Sb,S,,corresponding with a maximum on the freezing-point curve a t 546O.There are eutectic points a t 530° and 519O, corresponding with 61.3and 55 atomic per cent. of sulphur respectively. Mixtures of Sb,S,and Ag,S (m. p. 842O) give a freezing-point curve with two maximacorresponding with 3Ag2S,SbzS3, pyrargyrite (m. p. 483O), andAg,S,Sb,S,, miargyrite (m. p. 509O). Eutectics are found at 463”,455O, and 449O corresponding with 81, 64.5, and 28.2 mol. per cent.of Ages respectively.The minerals bolivianite, stephanite, pyro-stilpnite, polybasite, and polyargyrite are not represented in thethermal diagram, and have probably been formed from solution.The system Ag2S-As,S3 gives similar results, the compoundsformed being 3Ag,S,As,S3, proustite (m. p. 490°), and Ag,S,As,S,(m. p. 417O). Mixtures of artificial proust.ite and pyrargyrite form4 P. Lebedeff, Ann. Inst. Polytechn. St. Petersburg, 1911, I, 15, 691 ; A . , ii, 919.G. Zinke, JaArb. Min., 1911, ii, 117 ; A., ii, 359.Ann. Report, 1910, 227.7 H. C. Cooper, E. H. Kraus, and A. A. Tilein, A m r . Chem. J., 1912, 47, 273 ;8 Ann. RepoTt, 1909, 221.9 Zcifsch. anorg. Chem., 1912, 78, 245 ; A , , ii, 1169.A . , ii, 452. See also Centr. Min., 1912, 289 ; A . , ii, 645.REP.-VOL.IX. 258 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.an unbroken series of solid solutions, a point of considerable interestin view of the fact that the natural minerals only occur mixed to avery limited extent.In the case of the system PbS-Sb2S3 two compounds can berecognised, 5PbS,4Sb2S3, plagionite, and 2PbS,Sb2S3, jamesonite,but there is no evidence for the formation under these conditionsof the minerals zinckenite, warrenite, heretomorphite, semseyite,boulangerite, meneghinite, or geocronib.Similar investigations have been made of the binary systemsCu2S-Sb2S3, SnS-Sb2S3,fo and PbS-SnS.11 The former gives rise totwo compounds Cu2S, Sb2S3, corresponding with chalcostibite, and3Cu2S,Sb2S3, the main constituent of stylotypite. In the case ofthe second system the compound SnS,Sb2S3 is probably formed. Thethird system gives two series of solid solutions extending from0 to 8 per cent.SnS, and from 38-7 to 100 per cent. SnS. The existcence of a compound, SnS,PbS, although probable, has not beendefinitely established.A certain number of systems involving sulphides and other com-pounds has also been investigated; thus Quercigh12 has found thatSb,03 and Sb,S3 are miscible in all proportions in the molten state.A compound, 5Sb,S3,Sb203, is formed, which, however, does notmelt unchanged, but decomposes a t 522O into Sb2S, and a liquidphase. It gives a eutectic with Sb203, which has the composition ofthe mineral lcermesite, 2Sb2S,,Sb203. It would appear, therefore,that the latter cannot be obtained from fused mixtures of its com-ponents.The behaviour of the sulphide-chloride systems ofsilver,13 lead, and copper14 has also been investigated, and it hasbeen shown that the oxides of tin, zinc, lead, and copper, and thesulphides of the three latter metals are appreciably soluble inmolten sodium chloride.15Salt Fusions.-A very large number of binary mixtures of haloidshas been examined by various workers,l6 but we need not here domore than refer to certain investigations of binary mixtures ofsulphates of the alkali metals with those of the alkaline earths>'lo I?. Parravaiio aud P. de Cesaris, Gazzetta, 1912, 42, ii, 189 ; A . , ii, 942 ; andAtti Iz. Accad. Lincei, 1912, [Y], 21, i, 535 ; A., ii, 771.W. Heike, Metallurgie, 1912, 9, 313 ; A ., ii, 763.l2 Atti R. Accad. Lincei, 1912, [v], 21, i, 415; A . , ii, 562.l3 C. Sandonnini, ibid., 479 ; A., ii, 759.l P W. Truthe, Zeitsch. anory. Chem., 1912, 76, 161 ; A., ii, 763.l5 H. Houben, Metallurgie, 1912, 9, 592 ; A., ii, 1056.l6 Compare C. Sandonniui, Atti X. Accad. Liacei, 1912, [v], 21, i, 208, 493 ;ii, 77 ; A., ii, 350, 764, 918 ; M. Amadori, ibid., 21, i, 467 ; A . , ii, 758 ; H. Brand,Centr. Min., 1912, 26. Seealso Jahrb. Min. B d . - B d . , 1911, 32, 627 ; A., ii, 255.l7 G. Calcagui, Atti A. Acead. Lincei, 1912, [v], 21, i, 483 ; ii, 71, 240, 284 ;A, ii, 761, 918, 1056MINERALOGICAL CHEMISTRY. 259and to some work on the phosphates of lead.18 Finally, we maymention that a simple method of studying thermal dissociation hasbeen devised by I(.Friedrich,lg and applied by him t o the investi-gation of the dissociation of the carbonates of lead, zinc, iron,manganese, magnesium, calcium, and barium, including those whichoccur as minerals.Constitution of Hydrates and EEydroge1s.-G. TschermakFO incontinuation of his work on the dehydration of the silicic acids, hasmeasured the velocity of dehydration at constant temperature of anumber of hydrated salts. He finds that a well-marked retardationtakes place at certain points during dehydration corresponding withthe abrupt fall in vapour pressure which accompanies the passagefrom one stage of hydration to another. Experiments with sodiumsulphate, barium chloride, sodium phosphate, and strontium hydr-oxide gave good results, and even in the case of zeolites similarretardations were observed.The same holds good for hydrogels,retardation taking place a t certain definite points, and it wouldseem that certain hydroxides are to be regarded as containing waterof crystallisation a t the first retardation point, as, for example,2A1(0H),,H20, whilst others, such as Si(OH),, decompose, and givelower and more stable states of hydration.Constitution of the Silicates.-A work of considerable importancedevoted to this subject has recently appeared,21 but it is impossiblehere to do more than call attention to the nature of the remarkabletheory it sets forth.The silicates are regarded as derived, not from the simple hydr-oxides Si(OH), or Al(OH),, but from compounds formed by con-densation of five or six such molecules t o form respectively a pentiteor hexite group, linkage taking place through oxygen.Thesegroups may themselves be further linked together to form morecomklex groupings. By the replacement of hydroxylic hydrogenby metals, and of hydroxyl by fluorine formula= are obtained for anumber of natural silicates. Although it may be felt that theauthors g o too far when they assign formulae to certain glasees andto some of the products of the Portland-cement industry, yet theirviews deserve careful examination on the part of mineralogicalchemists.Some interesting suggestions as to the formulze of the felspars,leucite, nepheline, the zeolites, and the scapolites, have alsoA.V. M. Kroll, Zeitsch. anorg. Chm., 1912, 78, 95 ; A., ii, 1056.l9 Centr, blin., 1912, 174, 207, 616, 651, 684.2* Monatsh., 1912, 33, 1087 ; A., ii, 1140.21 ‘‘ Die Silicate in chemischer und techniucher Beziehung,” W. Asch and D. As&,Berlin, 1911.s 260 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.been made recently by H. S. Washington.22 He regards theseminerals as derived from two alumino-silicic acids, the first fourbeing obtained from the acid H,AlSi,O,, and the last fromHl,,AlSi3012, the hydrogen of these acids being replaced, not byvariable and independent atoms, but by atomic groups, the totalvalence of which is that of the basic hydrogens.Heats of Solution of Minerah-By the aid of a platinum calori-meter the heat evolved when quartz, alumina, and various silicatesare dissolved in hydrofluoric acid may be determined.23 I n this wayit has been found that the heat of solution of quartz is 29.93 cal.per gram molecule, that of vitreous silica 32.14 cal., and that ofalumina 93.86 cal.The heats of formation of certain crystallinesilicates have also been calculated, with the following results :adularia, 131.2 ; leucite, 101.8 ; microcline, 104.2 ; analcite, 85-22 ;natrolite, 95-76 ; heulandite, 59.44.Special Properties of Certain iKi.nerals.-The following interestingobservations on the solubility in water of calcite and of aragoniteare worthy of notice.? Solutions were made in silica vessels attemperatures of 25", 50°, and looo respectively, with the resultthat a t all three temperatures the solubility of aragonite was foundto be slightly greater than that of calcite, the ratio of the solubili-ties a t the several temperatures remaining, however, practically thesame.The actual solubilities observed expressed in milligrams perlitre are as follows: calcite, 14.33, 15.04, and 17.79; aragonite,15.28, 16.17, and 19.02.On determining the solubility of calcium carbonate got byremoving carbon dioxide from solutions of calcium hydrogencarbonate a t various temperatures, it was found that for theproduct obtained a t 25O the solubility was practically thq same asthat of calcite. The values for the product obtained at looo agreedwith those of aragonite, whilst the product obtained at 50° gaveintermediate results.These observations are in agreement withwhat is known as to the nature of the crystals which separate fromcalcium hydrogen carbonate solution at different temperatures.Some important work has also been done on the behaviour ofcalcium carbonate when heated under pressure in an atmosphereof carbon dioxide.25 By means of an apparatus provided withwindows of silica glass, and which could be filled with gas under apressure of 150 atmospheres and heated to 1600°, it was found thatpure calcite melts without decomposition a t 1289O when heated incarbon dioxide under a pressure of 110 atmospheres. Calcium0. Mulert, Zcitsch. unorg. Chcm., 1912, 75, 198; A., ii, 626.22 Amer. J. Sci., 1912, [iv], %, 555.24 J. Kendall, Phil. Mug., 1912, [vi], 23, 958 ; A., ii, 643.26 H.E. Boeke, Jukrb. Min., 1912, 1, 91 ; A., ii, 760MINERALOGICAL CHEMISTRY. 261carbonate and lime forin a eutectic containing 91 per cent. of theformer substance a t 121S0, but no mixed crystals or intermediatecompounds were observed. The heating curves indicate a changeof calcite into another variety a t 970°, but the optical characterremains unchanged.I n conclusion, we may mention that Meigen’s test for calcite andaragonite based on the colours they give when boiled with cobaltnitrate solution has been examined by Niederstadt,26 and thatVaubel27 has suggested that the differences in the chemicalbehaviour of these two minerals may be explained on the assump-tion that aragonite contains a small quantity of a basic carbonate.Chemical Crystallography.The most important matter to be dealt with in this section ofour report is the remarkable achievement of Fedoroff,28 who hasbrought to a successful issue the stupendous task of reducing to aform available for purposes of reference the chaotic mass of dataconcerning crystal form collected during the past hundred years.Since the days of Hauy and Mitscherlich chemists have been wellacquainted with the fact that all crystals of the same substance,even if they have been grown under different conditions and possessapparently very different shapes, can always be referred to the sameset of crystallographic constants, characteristic of the substance,except in those cases where the difference in form is due to poly-morphism, that is, t o the existence of two or more distinct varietiesof the substance.Again, it has been shown that even in the caseof isomorphous substances the angles almost invariably differ bymeasurable amounts unless they belong to the cubic system.Kow since the crystalline form is a highly characteristic propertyof a chemical compound, and as, moreover, it has actually beendetermined in the case of more than 10,000 substances, it wouldseem reasonable to suppose that the study of crystal form wouldafford a very valuable means of identification. To a certain limitedextent this expectation has been realised, for it has generally beenpossible to decide, without much difficulty, whether a certainsubstance A, produced in a chemical reaction, was identical witha known substance B, or not.I f , however, it happened that A wasproved t o be different from B, and the further question was akedI‘ Is A identical with any one of the 10,000 measured substances ? ”then the inquirer was doomed to disappointment, for until Fedoroff26 K. Niederstadt, Zeitsch. angew. Chem., 1912, 25, 1219 ; A., ii, 760.2i W. Vauhel, J. p r . Chem., 1912, [ii], 86, 366 ; A . , ii, 1180.28 E. S. Fedoroff, Zeitsch. Kryst. Mzh., 1912, 50, 513262 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.undertook the work, no classification of the data existed, and anyattempt a t comparison was a hopeless task.The apparently insuperable difficulty which has hitherto stood inthe way of any useful employment of the existing data is inherentin the fact that a very large number of compounds crystallise inthe orthorhombic, oblique, and anorthic systems.I n these systemsthe values of the crystallographic constants vary enormously withthe “setting,” that is to say, with the particular faces chose‘n asprisms, basal plane, and fundamental pyramid. Now the identityof two crystals for which different settings have been adopted canonly be established by a highly laborious comparison of angles, andthe task may be further complicated by the fact that the habit,that; is to say, the particular faces present and their relativedevelopment, may often differ greatly if the crystals have beendeposited from different solutions.The first and most important step, then, is to lay down somegeneral principles upon which to decide the choice of the particularsetting to be adopted, and thus to insure uniformity of treatmenton the part of different crystallographers measuring crystals of thesame substance produced in different ways, The great achievementof Fedoroff is that he has succeeded in developing the necessaryrules on the sound basis of the theory of crystal structure he hasdone so much to perfect.Granted, however, that the correctsetting has been ascertained, much remains to be done, and here,too, Fedoroff has succeeded in establishing order out of chaos.I n the general case presented by the anorthic system five inde-pendent angles are necessary for a complete determination of theform, and of the measured angles the following were selected fortabulation; the angle between the two prism faces, the two anglesthat these make with the basal plane, the angle from the base on tothe most important pyramid plane, and, lastly, the angle of thelatter with one of the two prisms.An index was next prepared ofthe 10,000 substances, arranged according to their systems, andaccording to the values of the above angles. To identify anunlabelled specimen of any one of these substances is now a fairlyeasy task. The crystals are measured, preferably, although notnecessarily, on a two-circle goniometer, the system is determined,the correct setting ascertained, and the characteristic angles eithermeasured, or calculated from other angles. The index is thensearched, the whole process occupying on an average not morethan two hours.The index, although complete, has not as yet been published,but when it becomes available, and crystallographers havemastered the principles which determine the correct setting, iMINERALOGICAL CHEMISTRY.263will no doubt be of immense and ever-increasing value to thechemist. The more, indeed, the chemist and the crystallographercan co-operate, or better, perhaps, be combined in the same person,the greater will be the benefits which may be expected to accrueto the workers in organic chemistry, to whom an easy, but sure andtolerably rapid method of identification is of first-rate importance.That the classification devised by Fedoroff really does what heclaims for it has been demonstrated beyond cavil by the successwith which he identified forty-eight out of fifty unlabelled speci-mens sent t o him from this country.Of the remaining two, onehad not been previously measured, and therefore was not in hisindex, and the crystals of the other were not sufficiently developedfor complete determination.It is, of course, obvious that cubic substances, which, after all,are not very numerous, are not amenable t o this mode of treatment,nor does it in most cases differentiate between the members of anisomorphous series. I n the latter case, however, the type oncedetermined, it is easy to identify the individual by other methods.Fedoroff’s work has been concerned with the co-ordination ofexisting data, but we have also to chronicle some important contri-butions to our knowledge of the crystallographic relations of groupsof analogous substances ; thus the morphology and optical charactersof the double chromates of caesium, rubidium, and ammonium withmagnesium chromate have been the subject of exhaustive study,29and it has been found that rubidium magnesium chromate andcaesium magnesium chromate exhibit crystal characters preciselysimilar in their mutual relations to those of the rubidium andmsium salts of every group of double sulphates and selenatesalready studied, whilst the position of the ammonium salt in themagnesium group is similar to that found in general for theammonium salt of any group of double sulphates or selenates ofthe series.In the field of organic chemistry, H.E. Armstrong and E. H.Rodd 30 have continued their studies of salts of p-dibromobenzene-sulphonic acid, and have shown that the lanthanum, neodymium,praseodymium, and cerium salts of this acid crystallise with ninemolecules of water in the orthorhombic system, and form a veryclosely isomorphous series. It will be noticed that the number threeplays a very important part in the economy of them salts, for theynot only each contain three phenyl groups, three sulphonate groups,and three times three water molecules, but they also possess a29 A. E. H. Tutton and Miss M. W. Porter, itfin. Mag,, 1912, 16, 169; A.,ii, 560.av Proc. Roy, Soc., 1912, A, 87, 204 ; A., i, 7562644 ANNUAL REPORTS ON THE PROGRESS OF CHEMISlRY.pseudotrigonal axis.The gadolinium salt with twelve molecules ofwater is oblique, but also possesses a pseudo-trigonal axis, and themorphology of all five compounds can be correlated with that ofp-di-iodobenzene. These facts admit of ready explanation on thePope-Barlow theory of the structure of benzene, the values of theequivalence parameters being exactly what we should expect if thebenzene structure is imagined opened out equally in all directionsperpendicular to the pseudotrigonal axis to a sufficient extent toadmit the insertion of the substituting groups in homogeneous closepacking.Another interesting piece of work has thrown fresh light on themorphotropic relationships which prevail between racemic com-pounds and their optically active components.31 Crystallineexternally compensated substances may occur either as mechanicalmixtures of the dextro- and lzvo-forms, as true racemic compounds,or as pseudo-racemic compounds, the crystals of the latter beingmade up of crystals of the separate optically active forms twinnedtogether. I n this last case the form of the compound crystal mustof necessity bear a very close relation to those of its components,but it has also been shown, that a very close morphotropic relationoften exists between the crystals of a true racemic compound andthose of its dextro- and lzvo-compounds. A particularly strikinginstance has long been known in the case of sobrerol, and to thismay now be added numerous fresh examples, such as racemiccamphoric anhydride, benzoyltetrahydroquinaldine, camphoroxime,the hydrogen racemates of potassium, rubidium, caesium, andammonium and thallium racemate. On calculating the equivalenceparameters in accordance with the Pope-Barlow theory, a very closecorrespondence is observed between the values obtained for theindividual components and for the racemic compound.The crystallographic relations of a number of salts of s-ethane-disulphonic acid have been studied by I(.Bleicher.s2 These includesalts of ammonium, lithium, sodium, potassium, calcium, strontium,barium, magnesium, zinc, cadmium, and copper. It would appearfrom the measurements that the nature of the metal is a minorfactor in determining the form, and it would therefore be ofinterest to know the form of the free acid.Unfortunately, how-ever, this could not be obtained in crystals. It was observed thatthe lithium salts-show greater analogies to the salts of the alkalineearths than with the salts of the alkali metals.This section may be fitly concluded by reference to two importantpapers of a more theoretical nature. We will begin with an31 G. Jerusalem, T., 1912, 101, 1268.32 Zeitsch. Kryslst. Mi?&., 1912, 51, 502MINERALOGICAL CHEMISTRY. 265exhaustive discussion on the part of C. Hlawatschs of the variousviews which have been held as to the nature of isomorphism. Thegeneral outcome of this discussion is i19 follows: I n the first place,i t is desirable to consider separately the three conditions usuallyconsidered necessary for isomorphism, namely, that two differentsubstances should (1) have similar crystal form, (2) have analogouschemical composition, (3) form homogeneous mixed crystals.I n thestrictest sense of the word all substances which fulfil the first condi-tion are isomorphous. As, however, the external form is merely theexpression of internal structure, we may say that those crystallinesubstances are isomorphous whose structure is analogous. Since theformation of mixed crystals and parallel growths is conditioned orassisted by analogy of structure, these phenomena afford indicationsof the existence of isomorphism. Since, moreover, similarity ofchemical composition will often result in analogy of structure, it isplain that isomorphous substances will often exhibit close chemicalanalogy.It is, however, quite possible for substances of verydifferent chemical composition t o have the same structure, and insuch cases we must be on our guard lest we seek to establishchemical relations where none as a. matter of fact exist. The forma-tion of mixed crystals cannot be regarded as an all-sufficient condi-tion for isomorphism, as the number of cases of their formation bysubstances of very different form is continually increasing.It urould seem possible, however, to classify substances accordingto their degree of isomorphism on the lines of the followingscheme :(1) The substances exhibit no chemical analogy, but show simi-larities in certain zones which frequently grow parallel.(2) The substances show analogies in their angles, but do notexhibit the same cleavages or habit.This may be termed isogonism.(3) The substances form mixed crystals, but have not analogousstructure.(4) The last case is not to be confused with that presented byisopolymorphous substances when the two modifications possess verydifferent stability.(5) The substances show like structure expressed, not merely bysimilarity of form, but by like cleavage, twinning, and habit.(6) The substances have similar crystal structure, and may formmixed crystals, but do not belong to the same crystal sub-class.(7) The substances possess similar structure with identical sym-metry, and form mixed crystals, but are not chemically analogous.(8) The substances show chemical analogy in addition to theother characters.Zcitsch.Zryst. Min., 1912, 51, 417266 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.(9) Lastly, they possess chemical analogy, form mixed crystals,have similar structure, and angular relations which are functionsof the atomic weights of the interchangeable elements.It is clear, then, that no small difficulties beset all attempts togive a precise definition of isomorphism. Some of these have alsobeen commented upon by T. V. Barker,% who has called attentionto a number of cases of what he terms unusual types of isomorphism,where close similarity of form is associated with great divergenceof chemical type. As examples may be quoted, the compoundsCuTiF,4H20, C’uCbOF,,4H20, and CuW02F,4H,0, which are allisomorphous and oblique, or KClO,, BaSO,, and KBF,, which areisomorphous and orthorhombic, or, again, the well-known case ofCaCO, and NaNO,, which are closely isomorphous and rhombo-hedra]. Barker points out that on the ordinary theory of valencyno strict chemical similarity can be demonstrated between themembers of the above groups, and the same holds good for manyothers which he enumerates.If, however, the co-ordination theoryof Werner be adopted, analogies at once become evident, as may beseen if the members of the first group of compounds quoted abovear0 written in the following form:[TiFJCu + 4H,O ; [Cb:ACu + 4H,O ; [ W$]Cu + 4H,O.I n developing his argument, Barker draws attention to the greatdifficulties which attend the application of the Pope-Barlow theoryto these complex inorganic compounds, and points out that theconception of a single valency volume may lead to conclusionswhich are mutually inconsistent. It is obvious that the views putforward in these two communications may be expected to lead tomuch further discussion and research.Artificial Formation of Minerals.The workers a t the geophysical laboratory in Washington havepublished in detail the results of an elaborate investigation into theconditions of formation and mutual relations of the mineralsulphides of iron.35 They find that crystals of marcasite can beobtained by the action of hydrogen sulphide on ferric salts or bythe action of hydrogen sulphide and sulphur on ferrous salts.Lowtemperatures and the presence of free acid favour its formation,pure marcasite being produced in a solution containing 1 per cent.of sulphuric acid.Less acid solutions and higher temperaturesgive mixtures of marcasite and pyrites. The latter mineral is34 T., 1912, 101, 2484.35 E. T. Allen, J. 1,. Crenshaw, J. Johnston, and E. S. Larsen, Amcr. J. Xci.,1912, [iv], 33, 169 ; A., ii, 354MIKERALOGlCAL CHEMISTRY. 267formed by addition of sulphur from solution to amorphous ferroussulphide or to pyrrhotite and by the action of soluble polysulphidesor thiosulphates on ferrous salts. When heated to 450° marcasiteis slowly converted into pyrite with evolution of heat, the changebeing an irreversible monotropic one.These observations are in accord with the f a c t that althoughpyrite may occur as a primary constituent of magmas, marcasite isnot so formed.Pyrite occurs in deep veins and in the neighbour-hood of hot springs, where it is deposited from water more or lessalkaline. Marcasite, on the other hand, occurs in surface veins,and was deposited from cold acid solution. On heating, pyrite isconverted into pyrrhotite, the change being a reversible one, andtaking place about 565O, for it was found that when heated at 550°in hydrogen stdphide pyrrhotite paased into pyrite, whilst thereverse change took place rapidly at 575O. Pyrrhotite is alsoproduced by heating iron with excess of sulphur, and there is strongreason to believe that the composition of pyrrhotite is not constant,the mineral being really a solid solution of sulphur in ferroussulphide. From observations of the specific volume of syntheticalpyrrhotite it is inferred that saturation occurs with 6.5 per cemtlof sulphur, a conclusion which agrees with the maximum percentageof sulphur observed in natural pyrrhotite.Examination of the synthetical crystals of pyrrhotite confirmsthe view that the substance is dimorphous.One form, a, stable athigh temperatures, is orthorhombic, with close approximation toangles of 60° in the prism zone. It is characterised by considerabledevelopment of the basal plane, and is usually elongated parallel tothe X axis. The form /3, stable at low temperatures, is hexagonal,and almost invariably forms cruciform twins. The dominant formsare the prism and a aharp pyramid.Troilite is not to be regardedas a distinct species, but is the end member of the pyrrhotite series;it has not so far been prepared free from iron.A most interesting study of the transformation and conditions offormation of the sulphides of zinc, cadmium, and mercury has alsobeen undertaken in the Geophysical Laboratory.36 It has beenfound that the change of sphalerite (zinc blende) to wurtzite is areversible one, and takes place about 1020O. The reverse changeoccurs slowly, and requires sixty-six hours to complete a t 800-9OOo.The density of wurtzite, 4.087, is slightly less than that of sphalerite,4-090, and the index of refraction of the latter, 2.3688, lies betweenthose of wurtzite, o =2*356 and e=2*378. Iron sulphide which sofrequently occurs in solid solution in natural sphalerite increases36 E.T. Allen, J. L. Crenshaw, and H. E. Merwin, A,mer. J. Sci., 1912, [iv], M,341 ; A,, ii, 1055268 ANNUAL REPORTS ON THE PROGRESS OF CHEMTSTRY.the specific volume, and also the refractive index, but greatlydiminishes the inversion point, the effects being proportional to theamount of iron present.Fair-sized crystals of wurtzite were obtained by sublimation a t1200-1300°, whilst small dodecahedra of sphalerite were got frommolten sodium chloride about 800°, and larger dodecahedra andtetrahedra from potassium polysulphide a t 350O. From aqueoussolutions both forms were deposited in crystals between 200° and400O. Hydrogen sulphide precipitates both forms from acid solu-tions at 250°, the production of sphalerite being favoured by raisingthe temperature, and that of wurtzite by increasing the acid con-centration. Cadmium sulphide exists in but one form, which canbe got in good crystals identical with those of greenockite by theaction of hydrogen sulphide on cadmium vapour.Mercurysulphide, on the other hand, exists in three forms. The first,cinnabar, D 8.176, is the most stable form, and is readily preparedby digesting either of the other forms with a solution of alkalisulphide. The second, meta-cinnabar, D 7-60, is black and cubic,and is precipitated from dilute acid solutions of mercury salts bysodium thiosulphate. The third is a new red form obtained aa afine, crystalline powder from stronger neutral solutions on additionof sodium thiosulphate.It is worthy of remark that we observe again here what hasalready been noticed in the case of pyrite, that the unstable formsof the sulphides are deposited from acid sohtions and the stableforms from alkaline solutions, although under certain conditions oftemperature and concentration they may also be obtained from acidsolutions.New Ninerals.AZbanite.-This name has been given to a black, lustroussubstance of a resinous aspect found in Albania.37A Zlcharite.-Three crystals of a mineral resembling antimonitein appearance were found with urbaite at Allchar in Macedonia.Accurate measurements obtained from one of these crystals showed,however, tha-t the angles of this substance were not only differentfrom those of antimonite, but could not be identified with those ofany known species.% The system is orthorhombic, a : b : c=0.9284 : 1 : 0*6080, and the forms present {OlO}, { l l O } , {210},A mpangabe'ite is a hydrated columbo-tantalate containinguranium found a t Ampangabe' in Madagascar, where it is met with37 C.I. Istrati and M. A. Rlihailescn, C?te?n. Zentr., 1912, i, 158T ; A., ii, 773.38 13. JeIek, ZeitsclL. Kryst. Mift., 1912, 51, 275.{Oll), (1011, (111)MINERALOGICAL CHEMISTRY. 269in large, brownish-red, elongated, rectangular crystals, which aresaid to resemble Br5gger’s %me1 odit,e.39Arduinite.-A zeolitic mineral from Val dei Zuccanti has beenanalysed by E. Billo~s,4~ who finds that the composition may beexpressed by the formula H,,CaA1,Na4Si,03,.As the properties ofthe substance differ somewhat from those of the known zeolites, hebelieves it to be a new species.Arsenoferrite.-The dark brown, pseudomorphous crystals similarin habit to iron-pyrites which occur on gneiss a t the Binnenthal,Switzerland, have been found on analysis to contain iron andarsenic in the ratio 1 : 2. It seems likely, therefore, that they origin-ally consisted of FeAs2, for which hypothetical mineral the namearsenoferrite is therefore proposed.4fBaeumZerite.-A colourless, transparent, and highly deliquescentmineral occurs in thin bands in the rock-salt of the Desdemona saltmine in the Leine valley.42 The substance possesses three perfectcleavages a t right angles to one another or approximately so. It isoptically biaxial and negative.The composition is KC1,CaC12, andaccording to Zambonini it is therefore probably identical withchlorocalcite, a mineral from Vesuvius described in 1872 by Scacchi,which has the same composition, and was described as crystallisedin cubes with cubic cleavage.43Betcljik-This mineral, a hydrated, uraniferous columbo-titanate, occurs at Ambolotara, Madagascar. It has already beendescribed as bl~mstrandite,~~ by A. Lacroix 45 now considers that itshould rank as a separate species.ChrombrugnateZZite.-A scaly, micaceous mineral occurs as lilac-coloured, lenticular masses in a bright green serpentine fromDundas, Tasmania,46 I t s composition appears to be :2MgC03,5Mg(OH)2,2Cr(OH)3,4H,0,which is somewhat analogous to that of brugnatellite,Cryptose.-From a discussion of the composition and propertiesof a felspar from San Bartholomeu, Alcobaga, V.Souza-ljlanciih 4739 A. Lacroix, Compt. rcnd., 1912, 154, 1040; A . , ii, 567. See also L’ull. SOC.franq. Nin., 1912, 35, 180.Extract from Rivista Min., 1912, 41.41 H. Baumhauer, Zeitsch. Kryst. Min., 1912, 51, 143 ; A., ii, 949.42 0. Renner, Centr. Min., 1912, 106 ; A., ii, 357.44 Ann. Bepurt, 1911, 255.45 Compt. rcnd., 1912, 154, 1040 ; A., ii, 567.46 L. Hezner, Centr. Min., 1912, 569; A., ii, 1061.47 C‘oirmun. Comm. Sew. Geol. Portugal, 1910-1911, 8, 12.F. Zambouini, ibid., 270 ; A., ii, 652.See also Bull. SOC. franc Nin.,1912, 35, 88270 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.concludes that albite can exist in polysymmetnc, oblique crystals,that is to say, in crystals having all the geometrical properties ofthe oblique system, but composad of microscopic lamelk twinnedaccording to the albite law.These lamellae may be so thin it9 t obe indistinct even under the highest powers of the pollarising micro-scope. For this variety which bears t o ordinary albite the relationof orthoclase to microcline, he proposes the name cryptose or krypto-klas.DidymoZite.-Greyish-white crystals somewhat resembling kyanibin appearance occur in crystalline limestone on the Tatarka river,Yeniseisk, Siberia.& They are oblique (a : b : c =0.6006 : 1 : 0.2867 ;p = 106”), and invariably twinned. Their composition is representedby the formula 2Ca0,3A1,03,9Si0,.Hat chit e.-Five minute crystals of a lead-grey mineral, probablya sulpharsenite of lead, were found in the Lengenbaeh quarry inthe Binnenthal in 1902. They cannot be identified with any of thenumerous minerals already described from that locality, and aretherefore regarded as belonging to a new species.49 They crystallisein the anorthic system with the following constants : a= 116O53$’,B = 85O121, y = 113°44Qf; a : b : c = 0.9787 : 1 : 1.1575.Manandorrite.-This interesting mineral has been met with incavities in the pegmatite veins of Antandrokomby, Madagascar,associated with rubellite and quartz. It occurs as white laminze, oras mamillary crusts of hexagonal plates.50 It possesses a micaceouscleavage with pearly lustre.A cleavage flake viewed in polarisedlight exhibits six regular sectors. An acute positive bisectrixemerges perpendicular to the plate, and the optic axial angle inair is about 30°. The composition may be represented by theformula Si,O5,B4A1,,Li4H2,. Water is not expelled until themineral is heated above 120O.iKeZnikowite.-A variety of iron sulphide has been described,which is said to have the same cornposition as pyrite, but is muchmore easily attacked by acids and other reagents. It is thereforeregarded as a labile form of iron disulphide, which differs frompyrite and marcasite, and the name melnikowite is proposed for it.61PaZuite.-Crystalline masses of a flesh-coloured mineral occur inthe tourmaline mines of Pala, San Diego Co., California.It hasresulted from the alteration of lithiophilite, and has the composi-tion 5Mn0,2P,O5,4H2O.62Ponite.-This name has been assigned to a greyish-pink carbonateA. Meister, Jahrb. Min., 1912, i, 403 ; A., ii, 950.49 R. H. Solly and G. F. H. Smith, Min. May., 1912, 16, 287.50 A. Lacroix, Bull. SOC. franq. Min., 1912, 35, 225.5l B. DOSS, Jahrb. Min. Bei2.-Bd., 1912, 33, 662.52 W. T. Schaller, J. Washi?tgto?z Acad. Sci., 1912, 2, 143; A., ii, 456MINERAIaOQICAL CHEMISTRY. 271of the formula FeC03,5MnC03, found in the Borca Valley,Roumania.MPreslite, see Tsumebite.Riva&.-This new Vesuvian mineral having the formula(Ca,NaJSi205, was recently described by F. Zambonini.54Salmonsite.-This name has been assigned to a manganese andiron phosphate found as buff-coloured masses a t Pala, California.55It appears to have been produced by the alteration of hureaulite,and has the formula Fe2O3,9Mn0,4P,0,,14H20.Samiresite occurs as fragile octahedra a t Samiresy, Madaga~car.5~It is related to blomstrandite and betafite, but differs from thelatter in containing more columbium and less titanium.It alsocontains a considerable quantity of lead (7.25 per cent. PbO) as wellas uranium.Sheridanite.-This mineral is a variety of chlorite approximatingto leuchtenbergite. It contains an unusually large percentage ofalumina, and a very small amount of iron, the composition beingrepresented with fair accuracy by the formula H,Mg3A12S~0,3. Itoccurs in some quantity as a foliated mass of pale silvery-grNnscales in Sheridan Co., Wyoming.57Sicklerite and 8tewartite.-These two minerals are alterationproducts of lithiophilite found at Pala, San Diego Co., California.68The former occurs as dark brown cleavage masses of high refractiveindex (1.74) and moderate birefringence, and has the formulaFe20,,6Mn0,4P20,,3 (Li,H),O.The latter, although it occurs inabundance, is so mixed with other minerals, that a pure samplecould not, be obtained for analysis. It is a hydrated manganesephosphate, and occurs as fine, pleochroic fibres of high birefringence,arranged normally to the cleavage cracks of the lithiophilite.Tsumebite or Pres1ite.-A crystalline, emerald-green mineraloccurs with azurite, zinc carbonate, and dolomite a t Tsumeb, Otavi,German South-West Africa.The density of the minute, obliquecrystals is 6-13. It is a hydrated phosphate of lead and copper ofthe composition given below, and was named tsumebite byI(. Busz:PbO. CUO. PZO5. H,O. Total.63.77 11-79 12-01 12-33 99.90These numbers lead to the formula 5(Pb,Cu)O,P,O5,8H20, theH&5( P0,),,433@,53 V. C. Butureanu, Ann. Sci. Univ. Jassy, 1912, 7, 183.O4 Rend. Accad. Sci. Fis. Mat. Napoli, 1912, [iii], 18, 223.‘55 W. T. Schaller, J. Washington Acad. Sci., 1912, 2, 143 ; A., ii, 456.O6 A. Lacroix, Compt. rend., 1912, 154, 1040; A,, ii, 567.67 J. E. Wolff, Arner. J. Sci., 1912, [iv], 34, 4’15; A., ii, 1181.58 W. T. Schaller, loc. cit272 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.ratio of lead to copper being approximately 2 : 1.The same mineralhas been described by V. ICoswky under the name preslite.59 Hisaccount agrees with that of BUSZ, except that he believes the crystalsystem to be orthorhombic instead of oblique.VoeZcke&e.-This name has been proposed for a hypotheticaloxy-apatite, 3Ca,(P04)2,Ca0, which is believed to be a constituentof many members of the apatite group.60Vrbaite.-This interesting mineral is a well-defined substanceoccurring in good crystals in a mixture of earthy realgar andorpiment a t the Allchar mine, Macedonia.61 It is orthorhombic(a : b : c = 0.5659 : 1 : 0.4836). The habit is either tabular parallelto 010, the cleavage plane; and these crystals show also faces of theforms {loo}, {331}, { l l l } , and {112}, or pyramidal with the form{ 111 } predominating.Small crystals are deep red and translucent,larger ones bluish-black and opaque. The streak is similar to thatof proustite. Tbe density is 5.3, and on analysis the substanceproved to be a thallous salt of the formula TlAs.@bS,, derived fromthe acid HA@,.I n addition to the above we must here take note of certainother substances which may possibly prove to be new species, butto which so far no names have been assigned. One of these hasbeen observed in minute, blue crystals on sandstone a t the mine,Etoile du Congo, Katanga, Congo Free State.g2 The mineral appearsto be a hydrated phosphate of copper and cobalt. It is ortho-rhombic, and the crystals are very similar, both in angles and inoptical properties to those of libethenite.Another substance not as yet fulIy determined occurs as smallnodules in the guano deposits of R6union.a It is soluble in water,and is a hydrated sulphate of ammonium and potassium, possiblythe potassium analogue of lecontite, (Na,NH4),S0,,2H2O.G.D’Achiardi 64 has recorded the existence of minute crystals of amineral containing copper and sulphur in the Carrara marble, butits exact nature remains obscure.Another mineral the characters of which do not seem to agreeexactly with those of any known species has been found in minute,green, oblique crystals on copper ore from Atacama.65 It is suggestedthat i t is a kind of natrochalcite having the formula:59 Zeitsch. Kryst. Min., 1912, 51, 521.Go A.F. Rogers, Amer. J. Sci., 1912, [iv], 33, 475; A., ii, 565.G1 B. Jeiek, Zeikch. Kryst. Min., 1912, 51, 365.63 A. Lacroix, Bull. SOC. f r a q . Min., 1912, 35, 114.65 P. Walther, Nature, 1912, 89, 322.G. Ceshro, Ann. SOC. Gkol. Belg., Publ. red. au Congo Belge, 1912, Fasc. 11, 41.I’roc. verb. SOC. Toscam Sci. Nat., 1912, 20, 54, 77.See Ann. Report, 1909, 224MINERALOGICAL CHEMISTRY. 273Mineral Analyses.A ZZophane.-Discussion still continues as to the nature of thesubstances grouped together under this name. The view held byStremme 66 that they consist of mechanical mixtures of colloidalhydrated alumina and silica being combated by S. J. Thugutt,67 whopoints out many differences between the natural minerals and arti-ficial products.He supports his contention by analyses of anauxiteand cimolite, which point to the individuality of these species.AZumgen.-As the result of an investigation of an occurrence ofalunogen and halotrichite from New Zealand, J. Uhlig68 has cometo the conclusion that the formula of the former mineral isAl,(S0,),,16H20, whilst it is still an open question whether thelatter is FeA12S,0,,,24H,0 or FeA1,S40,,,22H20. He points outthe special value of refractive index determinations for the identi-fication of these substances.Amphibole Group.-A number of members of this group havebeen nnalysed, and we may call attention to an emerald-greenactinolite from Sardinia,69 to two hornblendes from CentralFrance,70 which contain but little titanium, and to an amphibolefrom Hungary 71 exceptionally rich in this element.d patit e GToup.-The analysis of a calcium carbonato-phosphatecalled dahllite (= podolite) occurring in minute, hexagonal crystalsa t Tonopah, Nevada, has given occasion for a critical discussion ofthe published analyses of the apatite group.7, As a result of this,Rogers concludes that the members of the group are to be regardedas isomorphous mixtures of fluor-apatite, 3Ca3(P0,),,CaF2, chlor-apatite, 3Ca3(P04),,CaCl,, and carb-apatite, 3Ca3(P0,),,CaC03,together with a substance not hitherto recognised as entering intothe composition of the group, namely, oxy-apatite, 3Ca3(P04),,C'a0,for which the name voelckerite is proposed.H e also points outthat carbon dioxide has been recognised for some time as anessential constituent of apatite, and that 3Ca3(P0,),,CaC0,actually exists, not only as dahllite, but also as the main constituentof certain ill-defined rock phosphates. He has, moreover, made theAnn.Rcport, 1911, 253.G7 Centr. Jii?i., 1912, 35 ; A., ii, 267. See also Th. A. Nikolaevski, Bull. Acad.Imp. Sdi. J't. Pdtcrsbowg, 1912, [vi], 6, 715, who proposes the name shangavskitefor a hydrated colloidal alumina containing about 41 per ceut. of water.G8 Ibid., 723, 766.69 D. Lovisato, Atti 1:. Accad. Lincei, 1912, [v], 21, i, 105 ; A., ii, 358.70 P. Gonnard and P. Barbier, Bull. SOC. f r c q : . AfiiL., 1911, 34, 228 ; A., ii, 360.71 13. hlauritz, PijZd. Koxlony, 1910, 40, 551.t2 A. F. Rogers, Amer. J.Sci., 1912, Liv], 33, 475 ; A., ii, 565.KEl'.-VOL. 1s. 274 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.interesting observation that some varieties of pyromorphite alsogive indications of the presence of carbon dioxide.Somewhat similar conclusions have been reached by W. Tschir-winsky,73 who, in the course of his study of Russian phosphorites,distinguishes the following five groups : (1) fluor-apatites, (2)podolites, (3) those with the composition 2Ca3(P0,),,CaC03,CaF2,(4) those with the composition 3Ca3(P0J2,2CaC03, (5) phosphoritesin which the cementing material consists largely of aluminium andiron phosphates.74It is interesting to note that fluor- and chlor-apatites have beensynthesised by fusing calcium phosphate with fluorite or calciumchloride respectively, and it has also been shown that the twoapatites form a continuous series of mixed crystals.75A waruite.-Steel-grey, irregular grains of this mineral from thegold-washings on the Pelly River, Yukon, contain 74.34 per cent.of nickel and 21-35 per cent.of iron.76Aximite.-An analysis of hair-brown crystals from Nickel PlateMountain, British Columbia, has been published by R. A. A.Johnston.77Bddeleyite.-The occurrence of minute crystals and grains ofthis very rare and interesting mineral, native zirconia, is reportedfrom near Bozeman, Montana, where it is found in a corundum-s yenit e.78Bastnaesite.-This rare mineral has been met with in Madagascarin cleavage masses somewhat like the zinc-blende from Santanderin appearance.79 The mineral is optically uniaxial, and the smallerof the two indices has been found to be 1.7145 (Na).It is solublein sulphuric acid with evolution of carbon dioxide and hydrofluoricacid, and on examination with the spectroscope absorption bandsdue to didymium were seen. A quantitative analysis proved it to bea fluocarbonate of cerium, lanthanum, and didymium similar incomposition to the bastnaesite from Cheyenne Mountain, nearPike’s Peak. The same mineral has also been met with a t Welge-vonden, S. Africa, in hexagonal prisms.80Bauxite.-The composition of a number of bauxites especiallyfrom Croatia has been determined by M. KiGpatiE, who has likewisediscussed the mode of origin of the substance and the accessory73 Jahrb.Min., 1911, ii, 51 ; A., ii, 173.74 For analyses of a number of other Russian phosphorites, see A., ii, 949.75 R. Nacken, Ccntr. Bin., 1912, 545 ; A., ii, 1061.76 R. A. A. Johnston, Summary Rep. Geol, Surv. Canada, 1911, 256 ; A., ii, 358.i7 Ibid.7* A. F. Rogers, Amer. J. Sci., 1912, [iv], 33, 54 ; A, ii, 172.79 A. Lacroix, Bull. Soc. franc. hfin., 1912, 35, 108.D. P. McDonald, Trans. Geol. SOC. S. Africa, 1912, 15, 74MISERALOGICAL CHEMISTRY, 275minerals it contains.81 From his observations he has come to theconclusion that bauxite is a residue derived from dissolved lime-stones and dolomites, and consists for the most part of a colloidalhydrated aluminium oxide, Al,O,,H,O, which he terms sporogelite,together with diaspore, hydrargillite, and certain characteristicaccessory minerals.As it is a mixture of variable composition onecannot speak of pure or impure bauxite. E. Dittler andC. Doelter 82 have also occupied themselves with the composition,classification, and nomenclature of bauxite and allied substances.They have declared themselves adherents of the view that bauxiteconsists of a colloidal aluminium hydrate, and by treating thesesubstances with dyestuffs they distinguish between true bauxiteand a mixture of the gel with diaspore, hydrargillite, limonite, andkaolin, thus adopting the position of Cornu, who gave the namekliachite to the isotropic bauxite substance.Beryl.-From their examination of the beryls of Madagascar,Duparc and his assistants came t o the conclusion that two typesof this mineral exist.One is of prismatic habit, exhibits few.forms,has a relatively low density and indices of refraction, and containsbut little alkalis; the other is tabular in habit with a large basalplane; it possesses a higher density and refraction indices than theother type, and contains a considerable quantity of rubidium andczsium. These conclusions were criticised by Lacroix, who believesthat the beryls form a continuous series.83 I n a recent paper,Duparc84 maintains his original position, and quotes in support ofhis view two new analyses: (I) of a blue aquamarine from Ambato-lampy, and (11) of a green aquamarine from Sahanivotry, both ofwhich belong to his first type. The composition and properties ofthese beryls are very similar to those of the pink beryl fromTsilaisena, but differ considerably from those of the tabular berylof Maharitra, which is typical of the second type, and may reason-ably be classed as a separate variety under the name vorobyeviteproposed by Vernadsky.I n reply, Lacroix86 has reviewed all theascertained facts as to the properties, especially the density, ofberyls from Madagascar, and expresses his conviction that it isimpossible to admit the existence of two distinct types of beryl.It is interesting to notice that his views are confirmed by the resultof a recent careful study of the composition and properties of threeberyls from Elba.8681 Jahrb. Min. Bei1.-Bd., 1912, W, 513.82 E. Dittler and C. Doelter, Centr. Min., 1912, 19, 104.83 Ann.Report, 1911, 254.84 L. Duparc, 11. Wunder, and R. Sabot, Bull. SOC. f r a q . Nin., 1912, W, 239 ;86 L. Maddalena, Atli R. Accad. Lincei, 1912, [v], 21, i, 633 ; A., ii, 775.A., ii, 360. 8s A. Lacroix, ibid., 1912, 35, 200.T 276 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Bismuth.-An interesting occurrence of bismuth is reported fromthe pegmatite vein of Madagascar, where the element has been foundnative and SLS sulphide, both converted for the most part into abasic carbonate.87Clintonite Group.-A specimen of brandish from Tiriolo (Catan-zaro) was found to be unusually rich in magnesia.aCarnotite.-An anaIysis of a small quantity of this mineral foundas a light yellow powder at Mount Pisgah, Pennsylvania, supportsthe view that the species is a definite one belonging to the uranitegroup.The formula is (Ca,K2)(U02)2(V04)2,zH20, a result inharmony with those of analyses of material from Colorado andSouth Australia.89Ce2estite.-A specimen containing 3.2 per cent. of bariumsulphate, but no calcium, has been found in limestone near Inns-br~ck.~ODolomite.-Minute, rhombohedra from the limestone of theWetterstein, near Innsbruck, were found on analysis to have asomewhat abnormal composition, the results agreeing roughly withthe formula 7CaC03,4MgC03.91 A specimen of brown spar from thesame district may be represented as 4CaC03,4MgC03,FeCY),.A white mineral observed as thin seams along the joint-planes ofcoal proved on analysis to be ankerite.93 One specimen had nearlythe normal composition, 2CaC03,Fe(Mn)C03,MgC03. An analysishas also been published of a ferriferous dolomite from the SimplonTunnel .93Ep'dote.-Good crystals of epidote occur in pegmatite veinstraversing granulite a t Notodden, Telemark.94 These have been thesubject of a thorough crystallographic and optical study, and bothgreen and red crystals have been analysed.The results lend supportto the idea that the red colour of many epidotes is due to thepresence of tervalent manganese. A consideration of the seriesiron epidobclinozoisite leads to the conclusion that a change inthe amount of ferric iron of 0.3 per cent. alters the birefringencet o the extent of 0.001.Pelspur Group.-I?. Gonnard and P. Barbier 95 have continuedtheir work on French felspars, and have published two analyses ofmicrocline and two of orthoclase, whilst to N.Orloff is due ana7 A. Lacroix, B16zl. SOC. franq. Jfin., 1912, 35, 92.88 U. Panichi, Atli R. Accad. Lincei, 1911, [v], 20, ii, 518 ; A., ii, 57.89 E. T. Wherry, Amtr. J. Sci., 1912, [iv], 33, 574 ; A . , ii, 774.A. Haas, Jnhrb. Vin., 1912, i, 1 ; A . , ii, 564.91 Ibid.92 T. Crook, Min. Mug., 1912, 16, 219 ; A., ii, 565.y3 M. Delgrosso, Riv. Hin., 1912, 41, 56.S4 0. Andersen, Archiv Math. og ATnlz~rv., 1911, 31, No. 15 ; A . , ii, 1183.95 Bull. SOC. Min., 1911, 34, 235 ; A., ii, 359MINERALOGICAL CHEMISTRY. 277investigation of a number of anorthoclases from Pyatigorsk,Caucasia 96; the latter all contain barium, but no strontium.Speci-mens of labradorite sufficiently pure to repay detailed chemical andphysical examination have been described in recent years by Fordand Bradley and by Bonillas 97 respectively. Material very similarto the above has been found in basalt dykes in Co. Down, 1rela11d.O~The density of the perfectly fresh transparent crystal fragments is2.706. The indices of refraction are a=1*5630, P=1*5665, andy=1*5712, and t h e extinctions are - 1 1 O on c(OO1) and -23O onb(010). The composition of the mineral is closely represented bythe formula 33NaA1Si30,,5KA1Si,0,,62CaA12Si208.FichteZite.-A crystallographic investigation of this curioushydrocarbon, C18H23, has shown that the natural crystals fromKolbermoor, neax Aibling, have no plane of symmetry, but belongto the hemimorphic class of the oblique system.ggGarnet Group-In the course of an important investigation ofthe chemical composition of the crystalline schists, cordierite rocks,and sanidinites of the Laacher See region, R.Braunsf quotes anumber of analyses by J. Uhlig of the included garneb.Hniiyne.-Good crystals of the variety of this mineral termedberzeline, pure enough to repay careful analysis, have been found inpeperino near Ariccia.2 Their composition agrees very closely withthat calculated from the formula proposed by Brogger and Biick-strom, (Si04)3Al,(A1*S0,Na)Na4, which may be written in a formanalogous t o that of the garnet formula.ZhZeite.-An orange-yellow hydrated iron sulphate found as anefflorescence on graphite a t Mugrau, Bohemia, witg described bySchrauf in 1877 under the name ihleite.A very similar substancehas recently been observed with iron ores a t two localities in theisland of Elba.3 On examination under the microscope the mineralwas seen to consist of minute, rhombic or hexagonal plates possess-ing optical characters in accord with orthorhombic symmetry. Onanalysis the material from both localities was found, after deduct-ing impurities, to agree with the formula 2Fe20,,5S0,,16H2O. Acomparison of the properties of the substance with those of twospecimens of copiapite, one from Tierra Amarilla and the otherfrom Copiapo, leads to the conclusion that ihleite is identical withcopiapite, and that the latter mineral is to be regarded aa ortho.96 Annuaire Gkool.Min. Eussie, 1911, 13, 21 ; A., ii, 950.97 Ann. Report, 1911, 257.98 A. Hutchinson and W. C. Smith, Min. A l f a g . , 1912, 16, 267.99 A. Rosati, Zeitsch. Kryst. Min,., 1912, 50, 126.1 Jahrb. Milt. Bed.-Bd., 1912, %, 85.a N. Parravano, Atti R. Accad. Lincei, 1912, [v], 21, ii, 631.3 E. Manasse, Proc. verb. SOC. To~cann Sci. Nut., 1911, 20, 65278 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.rhombic, and not as oblique as is generally stated.4 Analysm ofthe specimens from Tierra Amarilla and from Copiapo confirm theformula given above.IZmenite.-The view that ilmenite is tm be regarded as FeO,TiO,,rather than as Fe203,Ti203, receives support from analyses of atitaniferous ore from Ekersund, and of an ilmenite crystal fromthe Urals.6 Titanium was precipitated by boiling a solution of thepotassium hydrogen sulphate melt, iron being first reduced bysulphur dioxide.Total iron was estimated in a solution reducedby sulphur dioxide and ferric iron iodometrically in a hydrochloricacid solution made in absence of air. Confirmatory evidence infavour of this view is found in the fact that whereas compoundscontaining tervalent titanium evolve hydrogen when treated withalkalis, ilmenite does not. Its behaviour, moreover, towardssulphuric acid is similar to that of a mixture of titanic acid and afarrous salt.1ridosmine.-Very small quantities of this mineral have beenfound in battery concentrates a t the New Rietfontein Mines, SouthAfrica.6 A sample analysed was found to consist of 95.5 per cent.of iridosmina containing about 45 per cent.of iridium. In thisconnexion attention may be called to a useful summary of all theelements found native compiled by W. Vernadsky.7Rornerqzne.-Some crystal fragments, seagreen in colour, andsufficiently transparent to be cut as gem-stones, have recently beendescribed by A. Lacroix from the pegmatites of Madagascar.* Thedensity is 3.27, and the refractive indices as follows: a=1*6613,p= 1.6733, y = 1.6742. The composition is represented by theformula 6 (Mg,Na,,&,H,) 0,4 (AI,Fe),03,5 SiO,, which differs some-what from the formula, MgO,A1,O3,SiOz, usually accepted for themineral.Lorandite.-A single crystal of this rare thallium compound,TlAsS,, has been identified on a matrix of iron-pyrites and barytesfrom the Rambler mine, near Encampment, southern Wyoming.9Libneburgite.-The results of a new analysis of this mineral maybe expressed by the formula Mg3(P04),1*77H3B03,6H20.10 Thedehydration curve shows that 6H20 are lost sharply at ZOOo, theremainder passing away slowly up to 600O.Marcasite Group-The important work on the mineral sulphidesAnn.Xeport, 1907, 298.W. Manchot aud B. Heffner, Zeitsch. anorg. Chem., 1912, 74, 79 ; A., ii, 265.C. B. Horwood, Trcms. Geol. Xoc. S. Africa, 1912, 15, 51.Centr. Mi%., 1912, 758.8 Cmpt. rmd., 1912, 155, 672 ; A . , ii, 1182.9 A. F. Rogers, Amer. J. Sci., 1912, [iv], 33, 105 ; A., ii, 265.lo W, Biltz and E. Marcus, Zeitsch. anorg. Chem., 1912, 77, 124 ; A., ii, 1181MINERALOGICAL CHEMISTRY. 279of iron carried out at the Geophysical Laboratory in Washingtonhas been already referred to, and attention must here be called toa lengthy discussion on the part of A.Beutell11 of the relationshipsof marcasite, mispickel, and glaucodote. He comes to the conclusionthat the composition of mispickel is FeS,+nFeAs,; the normalmineral is not, however, to be regarded as an isomorphous mixtureof FeS, and FeAsz, but as an individual compound, variations ofcomposition being due to admixture of marcasite on the one handor of labile Fe,As, on the other. Marcasites which contain arsenicare to be regarded as mixtures of marcasite and mispickel. Theformula of mispickel is a t least Fe,S,As,, and its constitutionJ?,<S'AI">Fe.The glaucodotes are not isomorphous mixtures of s- A sFeAsS and CoAsS, but mixtures of normal glaucodote, FeCoS,As,,of constitution similar to that of mispickel, with marcasite, Fe2As,,and usually mispickel also. The cobaltites are mixtures of Co,S,As2with FezS2As2, and usually pyrites, FezS4, normal cobaltite being/ C d ,represented as Aqm/hs.Nica Group.-The composition of a sericite which occurs ingreen talc-like aggregates in cracks in quartz strings near Tan-y-bwlch, North Wales, approximates very closely to that of amuscovite from Bengal, and conforms to type I of Clarke's formulae,Al( SiO,*R,) (SiO,=A1),.12MoEy bdenite.-Analyses have been published of specimens foundin quartz in the Stilo district of Calabria.13NepheZite.-The difficulties which stand in the way of a satisfac-tory representation of the composition of nephelite were referredto last year,l4 and it was then pointed out that the analyses alwaysshow an excess of silica above that required for the formulaNablSiO,.The view that this excess is present as silica held insolid solution has received confirmation from recent synthetical~0rk,15 which has demonstrated that when silica, alumina, andsodium carbonate are fused together in the proportions required t oform NaAlSiO,, some of the sodium volatilises, but whereas theexcess of alumina separates as corundum, no free silica can bedetected by the microscope. The mineral can, however, be repre-sented it9 consisting of mixtures of the three molecules, NaAlSiO,(soda-nephelite), KAISiO, (kaliophilite), and NaA1Si30, (albite).l1 Centr.Min., 1912, 225, 271, 299 ; A . , ii, 652.l2 A. Hiitchinson and W. C. Smith, Min. Mag., 1912, 16, 264.l3 R. Nasioi and E. BJschieri, Atti R. Accad. Lincei, 1912, [v], 21, i, 692l4 Ann. Report, 1911, 260.l5 N. L. Bowen, A7ner. J. h'ci., 1912, [iv], 33, 49 ; A . , ii, 176.A., ii, 773280 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Analyses 16 of nephelite occurring in intimate association with albitetend to show that the maximum value of the silica ratio is 2.2.Penninite.-Colourless, transparent, roughly hexagonal platesoccur associated with the ophicalcite at Recess, Connemara, Ireland,and have approximately the same composition17 as the compactvariety of penninite known as pseudophite, of which numerousanalyses from different localities have from time to time beenpublished.Pickeringit e.-A reexamination of a substance, called picro-allumogene, by Roster in 1876, and to which the formula2MgS0,,A12( S04)3,28H20was assigned, has established its identity with pickeringite,MgS04,A12( S0,),,22H20.18The latter formula has been confirmed by analyses of specimensfrom an iron mine in Elba, from crevices in slate near Lehesten,Saxe-Meinigen, and from the alum-shales of Wetzelstein, near Saal-f eld.l9PZagionite.-An elaborate crystallographic examination of speci-mens from Oruro, Bolivia, has been made by F.Zambonini. Thecomposition of these crystals agrees closely with that required bythe accepted formula 5PbS,4Sb2S3.20 The results of this investiga-tion have led Zambonini to discuss the relations existing betweenplagionite, heteromorphite, and semseyite.He traverses the viewput forward by Spencer that these minerals form a morphotropicseries, and believes rather that they constitute an isomorphous seriesof mixed crystals, of which the end members are 5PbS,4Sb,S3 and5PbS,2Sb2S,. He finds support for his conclusions in the syntheti-cal work of Jaeger and van Klooster,21 who, by the thermal analysisof the binary system PbS-Sb2S3, have demonstrated the existenceof two compounds, 5PbS,4Sb,S3 (plagionite) and 2PbS,Sb2S,(jamesonite), but have obtained no evidence of the formation ofcompounds corresponding with zinckenite, warrenite, hetero-morphite, semseyite, boulangerite, meneghinite, or geocronite.PyrophyZZite.-A. Haas22 has analysed an earthy, dull green t obrown mineral found in small quantities in ‘‘ Muschelkalk,” nearInnsbruck.I n composition it is intermediate between pyrophylliteand giimbelite.H. W. Foote and W. BI. Eradley, Amer. J‘. Sci., 1912, [iv], 33, 439; A., ii,569.I7 A. Hutchinson and W. C. Smith, Min. Mag., 1912, 16, 264.l9 H. Hess von Wichdorff, Centr. Uin., 1912, 42 ; A., ii, 266.2o Bivista Min., 1912, 41, 1.21 F. ill. Jaeger and ti. S. van Klooster, Zeitsch. nnorg. Chem., 1912, 78, 245 ;G. D’Achiartii, Proc. verb. SOC. Toscnna. Sci. Nut., 1310, 19, 25 ; A., ii, 174.A., ii, 1169. Jnhrb. Min., 1912, i, 12 ; A., ii, 564MINERALOGICAL CHEMISTRY. 281Pyroxene Group-In the course of a description of the rocksof the Los Archipelago, West Africa, A.Lacroixs has noticed agabbro which contains a monoclinic pyroxene. This mineral con-tains much magnesium, is almost uniaxial, and belongs to thegroup of substances described as enstatite-augites by Walil, and towhich Winchell assigned the name of pigeonite. Analyses havealso been published of interesting augites from the province ofR0me;4 and from the plateau of Central France25; the latter con-tains a considerable amount of titanium, and may be called titan-augites .Revdimkite.-An apple-green ferrimagnesian silicate containing6.2 per cent. of NiO, found in small quantities in a deposit ofchrome-ironstone in the Caucasus, has been referred to this species.2GRutiZe.-The composition and mutual relations of the mineralsof the rutile group have been discussed by W.T. Schaller.27 Heincludes in this group rutile, cassiterite, mossite, tapiolite, nigrine,iserite, ainalite, ilmenorutile, and striiverite, and from an exam-ination of the published analyses he concludes that all thesesubstances are to be regarded as isomorphous mixtures of two ormore of the following compounds : ferrous columbate, Fe(CbO,),,ferrous tantalate (tapiolite), Fe(TaO,),, ferrous titanate, Fe(TiO,),titanyl titanate (rutile), (TiO)(TiO,), stanyl stannate (cassiterite),(SnO)(SnO,), and ferrous stannate, Fe(SnO,),. Small amounts ofzinc arsenate, zinc stannate, ferrous arsenate, and manganous tan-talate may also be present.Of the minerals mentioned above as composing the group, onlytapiolite, rutile, and cassiterite are to be regarded as distinctspecies.Mossite is columbium tapiolite. Nigrine and iserite areiron rutile, ainalite is tantalum cassiterite, while striiverite fromPiedmont is to be considered a mixture of 29.9 per cent. of ferrouscolumbate, 27.4 per cent. of ferrous tantalate, 2.6 per cent. offerrous titanate, and 40.1 per cent. of titanyl titanate.It has recently been suggested that rutile may owe its colour tovanadium rather than to iron oxide, and the wide distribution ofvaoadiuni and chromium in small quantities has been confirmedby the analysis of various rutiles in which V,O, and Cr,O, have beenfound in quantities ranging up to 0.55 per cent. and 0.39 per cent.respectively.28Salt.-The older salt beds exploited in the Berlepsch mine a t23 Bull.SOC. franc. Min., 1912, 35, 26.24 N. Pnrravano, Atti X. Accad. Lincei, 1912, 21, ii, 469 ; A., ii, 1182.25 F. Gonnsrd and P. Barbier, Bull. SOC. fmne. Min., 1911, %, 228.% N. Besborodko, Jnhrb. Min. Bed. -Bd.: 1912, 341, 783.28 T. L. Watson, J. Washington Acad. Sci., 1912, 2, 431 ; A., ii, 1179.3 2 6 1 1 . U.S. Geol. Survey, 1912, No. 509, 9 ; A., ii, 773282 ANNUAL REPORTS ON THE PROGRESS OF CHENISTRY.Stassfurt have been the object of an elaborate and interestingchemicemineralogical in~estigation.~g Representative samples weretaken a t various depths in the deposit, and their constituentminerals were isolated and identified, and their relative proportionsdetermined.They include anhydrite, carnallite, kieserite, langbein-ite, loewite, salt, sylvite, polyhalite, and vanthoffite. The composi-tion of a specimen of the latter mineral agrees with the formula3Na2S04,MgS04. A discussion of the conditions of formation ofthis deposit in the light of van’t Hoff’s work leads to the conclusionthat the temperature could not have been less than 7 2 O when thesebeds were laid down.The crystallisation of salt from pure aqueous solutions, fromsolutions containing carbamide, and from an artificial ‘‘ sea-water ”have been carefully studied by C. Fastert.30 The principal resultsof this interesting piece of work are i ~ 9 follows: I n pure aqueoussolution the faces of a distorted cube grow equally fast.Additionof carbamide increases the solubility of the salt, and, as is wellknown, gives rise to the combination of cube and octahedron. Therelative development of these faces and their velocity of growthdepend on the amount of carbamide present. On evaporating anartificial sea-water a t 25O, salt crystallises in octahedra within thelimits of the upper carnallite region and the bischofite region ofvan’t Hoff. At 83” it crystallises in cubes, except within thebischofite region, where octahedra are obtained. Under these con-ditions the presence of magnesium chloride is the determining factorfor the production of the octahedral form.Sapphirine.-This mineral is present in small, greenish-blackgrains associated with rutile in a considerable dykelike mass con-sisting largely of ilmenite occurring in anorthosite rocks a t St.Urbain, Quebec.31 Their composition is given under I below.Trans-lucent crystal fragments of the same mineral have also beenreported from the pegmatites of Madagascar.32 They are deep bluein colour, and present a general resemblance to the Greenland speci-mens, although their density,. 3.31, and refractive indices,a=1*7042, 6=1*7074, y=1*7097, are somewhat less than those ofthe Greenland mineral. The results of an analysis are given under11. A comparison of the molecular ratios given under Ia and 110will show that in neither case do the results agree well with thecommonly accepted formula, 5Mg0,6A1,Os,2 SiO, :29 0. Riedel, Zeitsch.Kryst. Mila., 1912, 50, 139 ; A . , ii, 265.30 Jahrb. Min. BeX-Bd., 1912, 33, 265.31 C. H. Warren, Amer. J. Sci., 1912, [iv], 33, 263 ; A . , ii, 360.A. Lacroix, Compt. rend., 1912, 155, 762MINERALOGICAL CHEMISTRY. 283I. 11. Ia. IIa.SiO, ........... 13 *44 1 4 *90 2 '00 2 .ooA1,0, ............ 62 '98 62.55 5.54 4 *96 ............ 4.46 21 *201.78 } 4'54MgO 15 '28FeO ............ 9.08Spodumem.-Ths behaviour of spodumene on heating, and itsrelation to the products obtained by fusing together silicates oflithium and of aluminium have been the subject of several investi-gations.33 As regards its melting point, i t has been pointed outthat the true melting point is the temperature a t which the sub-stance passes from the anisotropic to the isotropic-amorphous condi-tion.It has been found that in this mineral double refractiondisappears in the case of fin0 powder after heating to 950O. Thedensity which is unaltered by heating to 920° is reduced from3.147 to 2.370 at 980°, whilst the heating curve shows a markeddiscontinuity at 950O. All these facts point to the melting pointbeing 950°, a temperature which marks, therefore, the upper limitof formation of the oblique crystals of spodumene. On heating to atemperature of 1O1Oo there seems reason to believe that a furtherchange occurs.34 In connexion with this work we may note thatthe thermal study35 of the binary system composed of the meta-silicates of lithium and aluminium has established the existenceof two compounds, 2Li,Si03,A12(Si0,), and Li,Si0,,A1,(Si0,)3.Thelatter appears to be very different from spodumene, which givesrise, however, to the same product when fused and cooled slowly.Striivem'te.-Black, lustrous grains from a tin-bearing alluviumon the Sebantun River, Kuala Kangsar district, Perak, have thefollowing composition 36 :TiO,. Ta,O,. Cb,O,. FeO. MnO. SnO,. SiO,. H,O. Total.45'74 35-96 6'90 8.27 trace 2.67 0-20 0.50 100*2.1These results support the view that struverite is an isomorphousmixture of tapiolite, Fe(Ta,Cb),06, in rutile, TiO,. A mineralwhich is probably a member of this group has lately been found inMadagascar in large, tetragonal crystals.37SuZphates.-Hydrated sulphates of aluminium, iron, and mag-nesium have been observed in veins in the Sonnenburg Tunnel ofthe Brenner Railway.% The material appears t o consist for themost part of halotrichite and altered epsomite, accompanied bymirabilite, picromerite, and glaserite.33 K.Endell and R. Rieke, Zeitsch. anorg. Chem., 1912, 74, 33 ; A . , ii, 266.a4 A. Brun, ibid., 75, 68 ; A., ii, 569.35 R. Ball6 and E. Dittler, ibid., 76, 39 ; A., ii, 758.96 T. Crook and S. J. Johnstone, Min. Mag., 1912, 16, 224 ; A., ii, 566,sI A. Lacroix, Compt. rend., 1912, 154, 1040 ; A., ii, 568.P8 A. Brunuer, Rivista Min., 1911, 40, 47284 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Synchysite.-The identity of synchysite with the fluo-carbonateof cerium metals, parisite, suggested by Palache and Warren,sQ hasbeen confirmed by the study of the optical properties of the twominerals.As, moreover, the density is the same, and partialanalyses gave R,O,=60*95 and 60.71 per cent., CaO=11*96 and10.70 per cent. for synchysite and parisite respectively, theiridentity may be regarded as securely established.40Thorianite.-Three specimens of this mineral have recently beenanalysed. The first from Ceylon41 contains more uranium oxide(23'5 per cent. U,O,) and less thoria (65.4 per cent.) than mostof the thorianite previously examined. This may be explained byassuming that the mineral is an isomorphous mixture of uraniumand thorium oxides. The results obtained with the second lead theanalyst, M. Kobayashi,42 to the conclusion that two distinct typesof thorianite exist, the ratio Tho, : UO, being almost exactly 6 : 1in the one case and 2 : 1 in the other, the corresponding percentagesbeing Tho,= 78 and 60, U,O,= 15 and 33.The existence of thesesimple ratios does not support the view that thorianite is to beregarded as an isomorphous mixture of the two oxides. Thereappears, moreover, to be a certain amount of difference between thecrystals of the two varieties, those with blunt edges containing morethorium than those with sharp edges. The third specimen contains74-2 per cent. of Tho, and 14.1 per cent. of U02?TozcrmaZine.-A very important contribution to our knowledge ofthis mineral has been made by W. T. Schaller,44 who has attemptedto throw light on some of the difficulties-it presents by determiningthe physical characters (density, axial ratio, and refractive indices),as well its the chemical composition of carefully selected materialfrom the following localities, mostly in California : (1) pink crystalsfrom Elba, (2) red crystals from Mesa Grande, (3) pale greencrystals from Mesa Grande, (4) green crystals from Haddam Neck,Connecticut, (5) blue crystals from Pala, (6) black crystals fromRamona, (7) black crystals from Lost Valley.The most important of his conclusions are: (1) that Penfield andFoote's general formula, E120B2Si,0,,, holds good; (2) there is noreason to suppose that foreign material is held in solid solution inthe tourmaline; (3) the amount of alumina varies inversely as theamount of bivalent oxides present; (4) a large number of com-394041172.434344Ann. Report, 1911, 261.E.Quercigh, Atti B. Accnd. Lincei, 1912, [v], 21, i, 581 ; A., ii, 773.W. Jak6h ant1 S. Tottoczko, Bulb. Acad. Sei. Cracow, 1911, A, 558; A., ii,Sci. Rep TShokis Imp. Unit,., 1912, i, 201 ; A . , ii, 1181.S. D. Kusnetzoff, Bull. Acnd. Sci. St. Petersboztrg, 1912, [vi], 361 ; A . , ii, 456.Zeitsch. Kryst. En., 1912, 51, 321MINERALOGICAL CHEMISTRY. 285ponents, not less than eight, have to be assumed if the mineral isto be represented as an isomorphous mixture; (5) the physical pro-perties vary with the composition, but the data at present availableare too meagre to allow of the deduction of exact relationships.Tridymite.-It has recently been found 45 that tridymite canreadily be prepared in the form of minute, hexagonal plates byfusing sodium silicate with three times its weight of sodium phos-phate for six hours a t 1000°.Another variety of silica, cristo-balite, can be obtained by heating silica-glass in a porcelain furnace.When in a fine state of division the different varieties of silica differlittle in their behaviour towards sodium carbonate solution, butvary greatly in their solubility in hydrofluoric acid; thus, whenheated for an hour with 1 per cent. hydrofluoric acid, the percent-ages dissolved are as follows: quartz, 5.2; tridymite, 20.3; cristo-balite, 25.8; amorphous silica, 52.9.Tscheff kinite.-A black mineral somewhat resembling euxenite inappearance, but easily fusible before the blowpipe and readilydecomposed by acids with gelatinisation, is found in the pegmatitesof Madaga~car.~o Two analyses indicate that the mineral isanhydrous and contains large quantities of cerium, lanthanum,didymium, and titanium.l'urpuoise.-A very interesting occurrence of crystallised tur-quoise is reported from near Lynch Station, Campbell Co., Virginia,where it is found in minute, anorthic, bright blue crystals, whichpossess nearly the same habit and angles as crystals of chalco-siderite.47 An analysis of pure material gave results in harmonywith the formula, 6A1(OH),,Cu(OH),H,,(P04),, assigned to themiaeral by Penfield.Zeolite Group-The commonly accepted formula for analcite isNa,Al,(Si0,)4,2H,0, which requires that soda, alumina, silica, andwater should bs present in the ratio 1 : 1 : 4: 2.The ratios actuallyobserved agree with this formula so far as soda and alumina areconcerned; the silica and water ratios are, however, in most casesconsiderably too high, although the proportion 2 : 1 is approximatelymaintained. An attempt to clear up this discrepancy by analysesof carefully selected homogeneous material from various localities,has merely confirmed the results of early observations, the meanvalue of the ratios for six different specimens, each of which wasanalysed in duplicate, being as follows 48 :N+O : A1,0, : SiO, : H,O = 1 : 1.06 : 4-36 : 2.20.It is probably related to tscheffkinite.45 R. Schwarz, Zeitsch. anorg. Chcm., 1912, 76, 422 : A., ii, 756.A. Lacroix, Compt. rend., 1912, 155, 672 ; A., ii, 1182,W.T. Sclialler, Amer. J. Sci., 1912, [iv], 33, 35 ; A , , ii, 173.4 4 W. H. Foote and \V. M. Bradley, ibid., 433 ; A., ii, 568286 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.The empirical formula must therefore be written in the formNa,Al,(SiO,),, 2H20 + sEf&5205, which may be interpreted to meanthat some other molecule, possibly Na2A1,Si60,,, 3H,O, is present insolid solution, the case being similar to that of nephelite. Excess ofsilica has also been noticed in an analcite from Vesuvius.49Among other zeolite analyses may be noticed one of Zuumontitefrom Heimbach, near Oberstein, where the mineral occurs in largewhite to reddish-white crystals, and three of phdZipsite61 from tbleucite-basanite of the Eulenberg, near Leitmeritz.The latter areremarkable as showing wide divergences in composition.Meteorites.Some interesting speculations on the origin of meteorites, moreparticularly of those exhibiting chondritic structure, have beenmade by L. L. Fermor.52 He believes that the material of suchstony meteorites was once part of a garnet eclogite existing a t aconsiderable depth below the surface of some primeval stellar body.The sudden diminution of pressure which took place on the disrup-tion of the body caused the garnet to liquefy with increase ofvolume, and the subsequent rapid fall in temperature lead to therecrystallisation of the material in radial aggregates of enstatiteand olivine, so characteristic of the meteoric chondules. He findssupport for this theory in evidence he has collected for the exist+ence a t a considerable depth below the terrestrial surface of a zoneof rocks rich in garnets.An important general investigation of an experimental characteris that carried out by F.Berwerth and G. Tammannu on thenatural and artificial ‘(burnt” zone of meteoric iron, and thebehaviour of Neumann’s lines in heated kamacite. The latter areprobably due to twin-lamellz revealed on etching, and if this viewis correct the lines ought to be weakened or disappear altogetherwhen the kamacite is annealed. This has actually been observedto be the case when plates of the Mount Joy meteorite were heatedat about 870O. In the case of the AvCe meteoric iron, the lines arenot visible in the outer layer of granular kamacite, but on goinginwards a layer of irregular structure is met with, containing frag-ments of the lines, which in turn gives place to the normal internalstructure.An artificial burnt zone exhibiting similar appearancescan be produced by heating to incipient fusion sections c.f kamacitewrapped in asbestos paper.49 S. J. Thugutt, Centr. Mi%., 1911, 761; A., ii, 176.50 V. Diirrfeld, Zeitsch. KryYt. Min., 1912, 50, 257; A., ii, 359.51 J. E. Hibsch and A. Scheit, Tsch. Min. Mitt., 1911, 30, 469; A., ii, 774.52 Asiatic Society of Eengal, 1912, Sept. 4.53 Zeitsch. anorg. Chem., 1912, 75, 145; d., ii, 652.For other analyses of zeolites, see A., ii, 57, 175, 176.Abs. Nature, 1912, 90, 213MINERALOGICAL CHEMISTRY. 287The question as to the possible cosmic origin of certain glassybodies from Oberkaunitz continues to excite interest.Weinschenk,one of the principal upholders of this view, classed them as tektite~,6~and based his opinion partly on the abnormal composition of theobjects. It has, however, been pointed out recently55 that frag-ments of an old glass vessel, probably of Venetian origin, haveapproximately the same composition as the Oberkaunitz tektites,and exhibit the same sort of surface markings as the glasses fromHuttenberg described by Weinschenk. It would 'appear, therefore,that the composition and surface markings of these bodies cannotbe regarded as affording evidence of their cosmic origin.Among individual meteorites we may note the following :Arabia.-A meteorite reported to have fallen in the El Hejazregion of Arabia in the spring of 1910 has been examined byJ.Couyat.66 It consists essentially of olivine, enstatite, and clineenstatite, with a small quantity of felspar, troilite, and nickel-iron.Brittany.-S. Meunier 57 has called attention to two meteorites,both of which fell in Brittany in recent times, but which have notas yet been properly examined. One fell on June 30th, 1903, inthe Canton of Rochefort-en-Terre, Morbihan. It consists princi-pally of olivine with a certain amount of pyroxene and minutegrains of nickel-iron. Chondrules are very rare.The other fell on July 4th, 1890, a t Saint Germain-du-Puel, Ille-et-Vilaine. The stone weighs 2-74 kilos., and has a very remark-able shape, for when pieced together with a fragment broken offfrom it before reaching the ground and found 3 kilometres away,it forms a plate 30 cm. long, 15 cm. wide, and only 5 cm. thick.From a study of the surface markings it is, moreover, evident thatthis plate must have traversed the atmosphere with one of its flatfaces foremost! An examination of a thin section shows that thismeteorite is rich in chondrules of enstatite dispersed through agroundmass composed of olivine, pyroxene, and grains of nickel-iron.El A'akhZa.-A shower of meteoric stones fell near the village ofE l Nakhla El Baharia in the Nile delta on June 28th, 1911. Thestones, which are coated with a glossy black skin, consist of a friableaggregate of crystalline grains, of which the larger part, about75 per cent., is diopside, the rest being mainly a brown olivine. Ina thin section a certain amount of interstitial matter can be seenbetween the grains, resolved by the microscope into an aggregateof felspar laths with augite and magnetite. No metallic iron is64 Ann. Report, 1911, 267.66 A. Rzehak, Centr. Min., 1912, 23.68 Compt. rend., 1912, 155, 916; A . , ii, 1183.67 Ibid., 154, 1739 ; A., ii, 776288 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.present. Three bulk analyses of the meteorite have been made byPrior,SB Pollard,sg and Meunier Go respectively, with concordantresults.Prior and Pollard agree that the composition of the diopsidemay be approximately represented as 3MgSi0,,3CaSiO3,2FeSi0, butwhilst the former has shown that the other main constituent isolivine approximating to 2Fe,Si0,,Mg,Si04, the latter has describedit as hypersthene. As Prior's identification rests on an analysis ofselected grains confirmed by a determination of the optical proper-ties, there can be little doubt as to its correctness.This meteorite approaches most nearly t o the Angrite group,but may be regarded as a new type, for which the name nakhliteis proposed.61HoZbrook.-A shower of meteoric stones took place on July 19th,1912, near Holbrook, in Navajo County, Arizona, and over 14,000separate individuals ranging in weight from 6665 grams to less than0.1 gram have been collected. The material consists of enstatite(50-60 per cent.), divine, diallage, and glass, with small amounhof nickel-iron, pyrrhotite, magnetite, and chromite. Well-markedchondrules of enstatite are present.62KroukL-A meteorite found near the place of this name in theGovernment of Minsk, Russ'ia, has been described by Gristchinsky.63It is a typical pallasite, and so exceedingly similar to the Braghinemeteorite that it seemed probable that it was really a representativeof the same fall.64 There seems, however, to be good reason forbelieving that it fell quite recently, in 1892 or 1893, and, if so, wehave the curious coincidence that two meteorites of similar com-position have fallen in the same district a t widely separated dates.Its externalappearance has been described by T. Hiki.65 Another more recentfall has also been recorded from the same country. It took placeon July 24th, 1909, and a number of stones were collected. Theseare composed of olivine and bronzite with small amounts of nickel-iron and troilite. A bulk analysis of the stone has been publishedby T. Wakimizu.660kano.-This meteoritic iron fell in Japan in 1904.A. HUTCHINSON.G. T. Prigir, Min. Mug., 1912, 16, 274.59 J. B. Pollard, Survey Department (Egypt), 1912, Paper NO. 25.60 S. Meunier, Compt. rend., 1911, 153, 785; Ann, Iteport, 1911, 267.e2 W. M. Foote, AnLer. J. Sci., 1912, [iv], 34, 437 ; A., ii, 118363 Awn. Geol. Aiin. RUSS., 1911, 13, 72.ti4 L. L. Ivanoff, i b i d . , 114.65 Ueitrage z. Min. Japnn, 1912, 4, 142(i6 Ibid., 145.See also F. Berwerth, Tsch. Mix.. Nitt., 1912, 31, 107

ISSN:0365-6217    

DOI:10.1039/AR9120900255

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

RADIOACTIVITY.The Atomic Weight of Radium.Two new determinations of the atomic weight of radium have beenmade. In one1 a much larger quantity of radium was availablethan in previous determinations, the total weight of purified radiumchloride being 1.35 grams. It was observed that a part of thispreparation, which had been kept two years in a stoppered quartztube, had absorbed oxygen, for on heating to 300° in nitrogen nowater was evolved, but on fusion in hydrogen chloride it evolvedchlorine and water and lost 5 per cent. in weight. The surfwe ofthe quartz tube wits completely disintegrated by the action of theradiations, Quartz is an unsuitable material to use for thepreservation of radium preparations. By fractional crystallisationof the material from aqueous hydrogen chloride, the value of theatomic weight found rose rapidly to 225.95, and did not furtherincrease after numerous further fractionations. The atomic weightwas determined by the aid of the methods and apparatus employedby T.W. Richards by finding the ratios RaC12/AgC1 and RaCl,/Ag.Radium chloride, dried in nitrbgen below 200° and fused in aplatinum boat in hydrogen chloride at 900°, was the starting point,this compound being rendered less hygroscopic and more stable inair by fusion. The mean value obtained in both series of deter-minations was 225-95, individual estimations not differing from themean by more than 0.03. Both in methods of purification and ofestimation the work was in the main a repetition of Madame Curie’sinvestigation, in which the vaTue found was 226.34 on the presentvalues for silver and chlorine.The main points of difference werethe preliminary fusion of the salt in hydrogen chloride, the precipi-tation of the solution with silver in the cold, and the correction forthe solubility of the silver chloride by the nephelometer. Thesedifferences, taken in conjunction with the greater quantity ofmaterial employed, no doubt account for the slightly different valueobtained, so that the number 226.0 may be taken to represent theatomic weight of radium, within a very narrow margin of error,when purified and estimated by these methods.0. Honigschmid, Moimtsh., 1912, 33, 253 ; A., ii, 523.U 289 REP.-VOL IX290 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.I n the other determination 2 very small quantities of material,usually between 2 and 3 milligrams of radium bromide, wereactually employed, and the determination was carried out on amodified form of Steele and Grant's micro-balance. The finalmaterial was prepared by the fractional crystallisation of 330 milli-grams of about 70 per cent.radium bromide, derived from Cornishpitchblende, from water and aqueous hydrogen bromide. Themethod of determination was also new, the bromide being con-verted into chloride and vice versa by ignition in hydrogen chlorideor bromide respectively, which had the advantages that there wereno transferences of the material during the whole determinationand only gaseous reagents were employed. The result for theatomic weight was 226.36, a number which is almost identical withthat of Madame Curie. The result is interesting mainly on accountof the methods, both of purification and of estimation employed.On account of the small quantity of the material and the novelmethod of weighing adopted, it is, however, impossible to comparethis result with the others until the errors have been quantitativelyevaluated. The single result given, in which a value practicallyidentical with the international figure was obtained for the atomicweight of barium, using as the material 3.5 milligrams of thechloride, is not sufficient to allow of this being done.As isdiscussed in the following section, fresh determinations of theatomic weight of radium by methods, both of purification and ofestimation, differing as much as possible from those followed byMadame Curie, are called for before this constant can be consideredcompletely known.The International Radium Standard.The primary object of the International Radium Standards Com-mittee has been fulfilled.A standard containing 21.99 milligramsof radium chloride, prepared by Madame Curie by methods identi-cal with those which she employed in the determination of theatomic weight and sealed up in a thin glass tube, has been acceptedas the International Radium Standard, and is now preserved atthe Bureau International des poids et mesures, SBvres, near Paris.A careful comparison, by various y-ray methods of this preparation,with three others containing respectively 10.11, 31'7, and 40.43milligrams of radium, prepared by Honigschmid in the course ofhis atomic-weight determination, showed that all four preparationsagreed with one another within the limits of experimental error,and certainly within 1 part in 300.One of the Austrian prepara-R. Whytlaw-Gray and Sir William Ramsay, Proc. Roy. Soc., 1912, A, 86,270 ; A., ii, 413KADIOACTIVITY. 291tions is to be preserved as a secondary standard a t Vienna, and incountries requiring them the National Testing Laboratories are tobe provided with sub-standards measured against both the Inter-national and Vienna standards. The funds necessary for thepurchase of the radium, both for the International and for theBritish sub-standard, have been privately raised in this country,and it is expected that the British standard will shortly be preparedand handed over t o the Nationd Physical Laboratory, where regularprovision will be made for the official teating of radium prepara-tions.The results of the comparison made in Paris of Madame Curie’sand the Austrian preparations show that, provided a raw materialis employed, such as Joachimsthal pitchblende, containing no oronly negligible quantity of thorium, independent workers using thesame methods can reproduce at will radium standards agreeing withone another and with the accepted International standard.Ifthorium is present in appreciable quantity in the radioactivemineral, the presence of mesothorium in the radium extracted wlll,of course, entirely vitiate the results, as it will yield, in additionto the practically constant y-radiation of the radium, a continu-ously varying y-radiation of the same order of penetrating power,due to mesothorium and its products.The absolute purity of the preparations so obtained is anotherquestion.For the present it suffices that the degree of purity isdefinite and can be reproduced a t will, as this is the primaryrequirement of any standard.The absolute purity of radium chloride fractionated by crystal-lisation from barium chloride to a constant chemical equivalent hasalready been called in q ~ e s t i o n . ~ I n the fractional crystallisationof isomorphous salt mixtures, the end product of the process is thatof minimum (or maximum) solubility.It is not invariably thecase that this minimum solubility is possessed by one of the twopure components; it may belong t o mixed crystals possessing adefinite composition. I f Honigschmid’s value, 225.95, is the trueatomic weight of radium, that of lead, calculated from it by deducbing five times 3.99, the atomic weight of helium, would be 206-0,and of uranium, by adding three times 3.99, would be 237.92.Whereas, if it be supposed that the mixture of constant composi-tion obtained by fractional crystallisation still contains 1 per cent.of barium chloride, the atomic weight of radium would be 227.0,from which 207.05 and 238.97, numbers more in accord with theaccepted values, would be the calculated values for lead anduranium.Since, however, in Madame Curie’s final preparations3 W. Marckwald, Physikal. Zeilsch. 1912, 13, 732 ;. A , , ii, 323.u 292 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.an addition of 0.6 per cent. of barium chloride notably strengthenedthe barium lines in the spark spectrum, it is very difficult to believethat preparations prepared by these methods still contain as muchas 1 per cent. of barium chloride. The experimental investigationof the point now being made will be awaited with interest. If othersalts of radium and barium are fractionaIly crystallised, as, forexample, the bromide, the proportion between the two elements forthe product of constant composition should not be the same as forthe chloride if mixed crystals of minimum solubility exist.a-R ay s .Further progress has been made in the exact determination ofthe ranges of the a-rays, with a view to testing the Geiger-Nuttallrelation between the range of the u-ray and the period of the changein which it is expelled.* I n the uranium-radium series the difficultquestion as to the character of the very low-range u-rays of uraniumitself has been elucidated by a careful comparison by a specialmethod of the range of the u-rays of pure uranium oxide with thoseof ionium and polonium, under conditions such that the absorptionof the rays in the active film was identical in each case.The formof the curves connecting ionisation with range was, as is to beexpected for homogeneous a-rays, identical with ionium andpolonium, but the uranium curve was different, and could becompounded out of two such curves shifted relatively to oneanother by 4 mm.of range. This indicates that the two a-particles,known to be expelled from the uranium atom in its first change,differ in range by 4 mm. The separate ranges in air at 1 5 O weredetermined to be 2.9 and 2-5 cm.6Confirmation of this has been obtained by the redeterminationof the proportion of ionisation contributed by the u-rays of radiumand uranium respectively from a uranium mineral, in which theseelements are in equilibrium.6 Boltwood’s ratio of 45 : 100 7 isobviously at variance with the fact that the range of, and thereforethe ionisation contributed by, the single u-particle of radium isgreater than that of either of the a-particles of uranium.Theratio calculated, on the present exact data between range andionisation, assuming the ranges of the a-rays of uranium to be, it9recently found, 2.9 and 2.5 cm., and that of radium to bo 3.3 cm.,is 58:lOO. The experimental value, obtained by comparing theAnn. Report, 1911, 275.6 H. Geiger and J. M. Nuttall, Phil. Mag., 1912, [vi], 23, 439 ; A . , ii, 408.6 Stefan Meyer and F. l’aneth, Sitzztngaber. K. Akad. Wiss. IVien, 1912, 121,7 Ann. Repo~t, 1909, 269.Ha, 1404RADIOACTIVITY. 293a-rays from films of pure uranium oxide of negligible thickness withthose from the equivalent quantity of pure radium, was found tobe 57.3:100, which a t once confirms the direct determination ofthe ranges, and renders it improbable that uranium emits twoa-particles, one of range about one-half that of the other, as hadformerly been inferred.8The apparatus employed in the determination of the ranges ofthe a-rays of uranium, the construction of which involved consider-able experimental skill, has been utilised in a much-needed reviewof the ranges of the a-rays from the products of the thorium andactinium series.9 The collected final results for all three series arecontained in the following table:Ranges in cm.a tSubstance.Uraniuiii-1 .................U ran ium-lZ ..................Ioniuni ........................Radium .....................Radium emanation .........Rad iuni . A ..................Radium-C' ..................Radiuni-F ..................Th oriuin .....................1< adio t hori iini ...............Thorium -X ..................Thorium ernanation ......Thorium-A ..................Thorium-C ..................Thorium-C' ..................Radioactininm ............Actiniun-X .................Actinium emanation ......Actinium-A ..................Actinium-C ..................0".2.372.752-853-133.944 *506-573 *582.583'674-084.745 '404 *558.164 '364-175'406.165.121592.502.903 -003-304-164 7 55-943.772 -723.874'305 '005 *704.808'604-604-405 -706.505.40Initial velocityx lo9 cm./sec.1-471 -541 *561 *611 '741'822 '061-681-511 *701 *751-851.931.822'211 -801-771 *932 '021-89The Geiger-Nuttall relation has been considerably strengthenedand extended as the result.I n all three series the curves obtainedby plotting the logarithms of the radioactive constants and of theranges as ordinates and abscissze respectively are in each seriesessentially straight lines of similar slope. For products of similarperiod the range of the rays of the uranium products are least, thatof the actinium products greatest, the thorium products being inter-mediate. Although the differences between the three series aresmall, they are undoubtedly of very great interest. Any a-particleis experimentally indistinguishable from any other, so long thevelocities are adjusted to equality, it9 can quite easily be arrangedby causing the swifter first to pass through a suitable thickness ofan absorbing medium.A11 are radiant helium atoms. The law of8 Ann. &port, 1911, 274.Geiger and Nuttall, Phal. Mag., 1912, [vi], a, 647 ; A . , ii, 1022294 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.retardation of the velocity during passage through an absorbingmedium and the law of increase of ionising power with loss ofvelocity are identical for all a-particles, and are independent of thenature of the parent atoms from which they have originated. Theprecise initial velocity of expulsion appears to be a function of theperiod of transformation, which is the same for all the members ofone series, but is different for different disintegration series. Hencethere must be some peculiarity of atomic structure preserved intactin the successive members throughout a series of disintegrations,pertaining to that particular series, and distinguishing it from otherseries. I f these data are confirmed, they are therefore obviously ofprime importance in connexion with the evolution of the elements.The clear exceptions to the rule are the a-rays of thorium itselfand of radioactinium.For the former the great difficulty of pre-paring the material free from subsequent products and of the deter-mination, on account of the lowness of the range, may account forthe discrepancy. For the latter, the range of the a-particles ofradioactinium is somewhat longer than that of actinium-X, and itis to be expected, therefore, that its period of average life should beless instead of greater.It is possible that one of these two periods,either that of 28.1 days ascribed to radioactinium, or of 15 daysascribed to actinium-X, may be in error. Naturally this hasfocussed attention on these two products, and already a preliminaryannouncement has been made that radioactinium consists of twosuccessive products, the first having the period of average life of28.1 days hitherto ascribed to radioactinium, but emitting no, orbut little, radiation, and a subsequent product of period about19 hours, emitting a-, P-, and y-rays. The method of separation,however, is not stated.10The substances for which the ranges, but not the periods, areknown, are uranium-ZZ, radium-C’, and thorium-C’. For the twolatter the very short periods indicated by the long ranges of thea-rays are about 1 0 - 6 and 10-11 second respectively, and thereforeare quite beyond the present methods of direct determination. Thenew value for the range of the a-ray of uranium-2, 2.5 cm., fits thecurve for the series much better than the previous value.Thecalculated values for the periods of uranium-ZZ and ionium arerespectively 2 x 106 and 2 x lo5 years. I f these are correct, thereshould exist per gram of uranium about 1 milligram of uranium-ZZ,a chemically non-separable element of atomic weight 234.5, thepresence of which, however, will only affect the accuracy of theatomic-weight estimation of uranium in the third decimal place.The quantity of ionium in minerals should be about eighty times10 J.Chadwick and A. S . Russell, Nature, 1912, 90, 403RADIOACTIVITY. 295greater than the quantity of radium, or 24.6 grams per 1000 kilos.(25 grams per ton) of uranium. I n view of this the failure todetect the spectrum of ionium calls for comment Op. 321).Attempts have been made to find a theoretical basis for the a tpresent empirical relation between range and period.11 It is clear,however, that it will not be easy to do so. The ranges of the a-raysfrom any one product are all alike, whereas the actual periods oflife of the individual disintegrating atoms are widely different, themean only of all the values being constant. Yet the relation holdsbetween the range, which is truly a constant for each individualdisintegrating atom, and the period, which is only a statisticalconstant. Any explanation of the rule would undoubtedly throwlight on the nature of the process of disintegration itself.In viewof the increasing number of far-reaching deductions which dependon the rule, its present purely empirical character must not be lostsight of. The rule explains a t once why no a-particles of a veryshort range, as, for example, 1 cm., have been detected. I f it holdsgenerally, the life of the product emitting such a radiation wouldbe so long that the number of rays emitted would be far below thelimit of experimental detection, even by the most sensitive methods.The string electrometer has been successfully employed in placeof the usual quadrant type, in the work of counting, by the electri-cal method, the number of a-particles expelled from a radioactivesubstance.I n conjunction with a photographic arrangement forrecording the jerks of the electrometer mirror, great advances inthe accuracy and trustworthiness of the method have been made, asmany as 1000 a-particles per minute being photographically regis-tered. The method should enable the fundamental constant, QJ12the number of atoms disintegrating per gram of radium per second,to be determined to almost any required degree of accuracy. A t thesame time the apparatus has been improved in sensitiveness andsteadiness by the use of carefully purified helium instead of air asthe medium ionised, and it is expected that even the individualrecoil-atoms, the kinetic energy of which is about fifty times lessthan that of the a-partikle, will ultimately come within its rangeof detection.13The scattering of the a-particles by collision with the atoms ofmatter is of two types, which have been distinguished by the terms“ single scattering ” and “ compound scattering.” The first appliesto the result of the multitude of very small deflections suffered byl1 H.A. Wilson, Phil. Mag. 1912, [vi], 23, 981 : A., ii, 617 ; F. Butavand,Lc Radium, 1912, 9, 203 ; A , , ii, 723 ; R. Swinne, Physikal. Zeitsch., 1912, 13, 14 ;A , ii, 219.l2 Ann. Report, 1909, 234.l3 H. Geiger apd E. Rntherford, Phil. Mag., 1912, [vi], 24, 618 ; A., ii, 1021296 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.all the a-particles in successive encounters, and the second to theoccasional and comparatively rare deflections of the a-particlethrough large angles as the result of single collisions, on whichsuch important theoretical deductions have been based.It has beenshown that the scattering, experimentally observed, agrees well withwhat is to be theoretically expected.14 The theoretical variation ofrange due to the varying chances of collision of the individuala-particles with the gas molecules has also been discussed.15Some interesting results have been obtained in the microscopicexamination of the tracks of single a-particles from polonium in aphotographic film. Under high magnifications up to 1700 diametersthe straight tracks are resolved into straight rows of dark points,corresponding with the granules of the emulsion.It is stated thatnot all the granules in the direct tract of an a-particle are affected,but there seems to be some lack of clearness on this point, and theopposite could certainly be argued from other facts in the paper.If the a-particles before reaching the film are caused first to traversevarying distances of air, the length of the track in the film and thenumber of affected granules which constitute the track, bothdecrease in constant proportion to one another and linearly withthe distance of air traversed. The range of the a-particle in aircan thus be deduced by a new method from a photomicrographicstudy of the tracks.16A simple method of measuring and of demonstrating to anaudience the range of the a-particle by projection has been devised.It depends on the fact that an atmosphere laden with fumes ofammonium chloride and acted on by an electric field clears whenionised.I f one of the edges of a rectangular transparent chamberis coated with an a-ray-giving substance, an electric field beingmaintained between the opposite faces, and the chamber is filledwith fumes of ammonium chloride, these clear away rapidly overthe region penetrated by the a-rays, leaving a sharp dividing linebetween the cloud and the cloud-free space."/3- and y-Rays.With the complete elucidation of the physical nature of thea-rays, the attention of investigators has largely been transferred t othe &rays, which continue t o yield results of the highest theoreticalsignificance.The actual photographs which have been published1912, [vi], 23, 901.l4 H. Geiger, Proc. Boy. SOL, 1912, A, 86, 236; C. G . Darwin, Phil. May.l5 K. F. Herzfeld, Physiknt. Zeitsch., 1912, 13, 547.l6 W. Michl, Sitmtgssber. K. Akad. Wiss. Wien., 1912, 121, IIa, 1431.K Przibram, ibid., 221R ADlOACTIVITY. 297of the “magnetic spectra ” of line sources of &rays, resolved intoseparate beams by a magnetic field, are full of interest, and revealthe extraordinary complexity of the phenomenon.’* A t leasttwenty-nine sets of distinct &radiations have been recognised inthe photographs of the rays of radium-B and -C. The &rays ofuranium-X and radium-E and the swifter &rays of mesothorium-2and of thorium-C+-D have not yet been resolved, and theirmagnetic spectra consist of, or contain, broad bands, which mayor may not prove to be resolvable into distinct lines by morepowerful methods.I n the other cases the &radiation has beenresolved and for each product several distinct beanis have usuallybeen recognised. I n the products of the thorium series thirteendistinct beams and two bands exist. This is in striking contrastto the a-rays. Each a-ray-giving product yields only one type ofa-radiation, or, to put it even more explicitly, each disintegratingatom gives one a-particle, the initial velocity of which is, withinthe narrow limits of experimental detection, the same for all thedisintegrating atoms of the same kind.Both types of radiation,however, suffer a loss of velocity in passage through matter, whichfor the 8-rays is much greater for the slower than for the fasterrays.19 Passing the radiation through absorbing screens causes themagnetic spectrum to be spread out. Hence these kind of experi-ments can only be done with preparations of infinitesimal massas sources of B-rays, such as the active deposits, or the radiumemanation enclosed in tubes of minimal thickness, in which theabsorption of the radiation in the preparation itself is negligible.In view of the large number of distinct types of 8-rays thatexist, the number of B-particles emitted per atom disintegratingis of great interest. The researches so far made, by measuring thenegative charge transported by the &rays from preparations inwhich the number of atoms disintegrating per second can beevaluated, indicate that most probably only one &particle isexpelled from each disintegrating atom.20 The number, forexample, found both for radium-B and for radium-C was 1.1, forradium-E less than one, and for uranium-X, thorium-D andactinium-D, deduced from previous measurements, 1, 0.8, and 1.4respectively.I n any case it is clear that the number is far lessthan one for each of the numerous distinct types of &radiationrecognised. Using the Loreatz-Einstein theory for calculating theJ. Danysz and J. Gotz, ?:bid.,0. v. Baeyer, 0. Hahn, and L. Meitner, Physikal. Zeitsch., 1912,E. Rutherford, “RadioactiveJ. Danysz, Le Rncliwm, 1912, 9, 1 ; A., ii, 219.6 ; A , , ii, 220.13, 264 ; A ., ii, 409.Suhstances and their Rodiations,” Cainb. Univ. Press, 1912, p. 253.l9 Baeyer, Zoc. cit.0. v. Baeyer, ibid., 485.Fig. SOc.H. G. J. Moseley, Proc. Boy. Soc., 1912, A, $7, 230; A . , ii, 1014298 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY,kinetic energy of the 13-particle a t various speeds, the kineticenergies of the numerous successive groups of &radiation givenout by radium-C can be well expressed by a relation of the formpE,+pE,.21 The values of E, and E, are respectively 1.12 and0.356 ( x lO13e ergs), p and p being integers having values between0 and 9 and 0 and 2 respectively.For radium-B, the successive groups show a nearly constant dif-ference of energy X3? which is nearly one-half of E, (0.173 x 10%ergs).The theory has been advanced that the 8-particles from anyone disintegrating radio-element are, like the a-particles, initiallyall the same as regards speed, but that, unlike the a-particles, theysuffer, whilst still within the parent atom, successive decrements ofenergy which is utilised in the production of the y-rays.TheP-rays are known to be very easily deflected after expulsion bycollision with the molecules of matter, whereas the a-particlesplough their way for the most part straight through them. Onthis view the y-rays are regarded as analogous to the characteristicX-rays excited in the elements by catlode-rays of above a certaincritical velocity. A t the time the theory was proposed, theseradiations had not been experimentally produced in elements ofhigh atomic weight on account of the difficulty of artificiallygenerating cathode-rays of the necessary velocity.It is to beexpected, however, that such characteristic radiations would havea penetrating power closely in accord with that possessed by theknown y-rays, whilst the energy of the cathode-rays necessary toexcite them would accord with that possessed by the faster &raysof the radio-elements. The view adapts itself to the conception ofthe “Saturnian” atom, in which a very large positive charge isconcentrated as a single nuvleus a t the centre and is surroundedby rings of electrons external to it and rotating in planes. I ntraversing these external rings of electrons, the ejected &particlesuffers its successive decrements of energy, each of which correspondswith the production of a y-ray.Thus, in the case of radium-C,the emission of the &particles is accomplished by the productionof p y-rays of one kind and p y-rays of another kind. Thesesuggestions are, no doubt, to be considered as more or less tentative.If further investigations establish the fact that the decrements ofenergy of the &particle occur by definite quanta during its passagethrough the parent atom, and if though p + p y-rap are produced,not p+ p kinds of y-fays but two kinds only result, the complexityof the &rays and the apparent homogeneity of the y-rays wouldbe accounted for, although the structure of the parent atom pro-21 E.Rutherford, Phil. Mag., 1912, [vi], %, 453, 8931 A., ii, 1024 ; 1913, ii, 4RADIOACTIVITY. 299ducing this result would require further elucidation. At first sight,however, the complexity of the &rays and apparent simplicity ofthe y-rays, taken in conjunction with the existence of 8-rays ofhigh velocity unaccompanied by y-rays, to be considered later(p. 313), seems additional evidence in favour of regarding the twokinds of radiation as not necessarily causally connected.The changes which attend the character of the @-radiation duringpassage through absorbing materials still occupy investigators.The gradual reduction of velocity in aluminium without, a t least,the complete destruction of the homogeneous character of the beam,is well brought out in the photographs of the magnetic spectra ofthe &rays of the thorium active deposit after passage throughaluminium foil.= Screens of different metals retard the rays pro-portionally to the density of the metal. The same conclusion hasbeen reached in experiments on the absorption of &rays renderedhomogeneous by magnetic sorting.23 The radiation is a t firstreduced in velocity, with an increase of the specific ionising power.I n consequence, the ionisation is a t first increased by passage ofthe radiation through aluminium foil.Only after 0.04 cm. of foilhas been traversed is the ionisation reduced by the absorbingscreens. However, in passage through platinum a totally differentcourse is followed. The homogeneity of the beam is completelydestroyed, and the ionisation, even when absorbing screens ofaluminium are used, now decreases according to the usualexponential law.Probably too little account, in former experi-ments both with /3- and y-rays, has been taken of the specific actionof the absorbing material. Light metals, like aluminium, behavevery differently from heavy metals, like platinum and lead.The y-rays of radium are so superior in penetrating power toordinary X-rays that it is hardly possible to decide whether ornot the two radiations are of the same type. The y-rays obey the“density law” of absorption much more closely than X-rays, butof recent years the recognition of characteristic secondaryX-radiations has gone far toward explaining the peculiaritiesexhibited in the absorption of X-rays by different substances.Thegap between the two types of radiation may be considered to havebeen definitely bridged by a research in which, in the first place,it has been shown that when the very soft type of y-rays, such asthose produced by radium-E, are used for comparison, theabsorption phenomena encountered are in no way distinct fromthose exhibited by X-rays. Even more important is the proof thatthe y-rays of radium-E are capable of exciting the same charac.0. v. Bneyer, Zoc. eit. J. Danysz, Compt. rend., 1912, 154, 1502 ; A., ii, 617. * W. Wilson, Proc. Boy. Soc., 1912, A, 87, 310; A., ii, 1023300 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.teristic radiations as are excited by penetrating X-rays24 in theelements with atomic weights between silver and neodymium.Undoubtedly, in the course of time, the few anomalies encounteredin the absorption of the y-rays, in which the “density law” isdeparted from, will be rendered clearer by this conception of theexistence of radiations characteristic of the atoms of matter andindependent of the character of the exciting radiation, so long asthis exceeds a certain minimum of what, in acoustics or optics,would correspond with pitch or frequency, necessary t o stimulatethe atoms into radiation.Even a-rays, it would appear, possess the power of exciting thischaracteristic radiation.The preliminary announcement has beenmade that an excessively small but detectable amount of y-radiationis excited when the a-rays of radium4 impinge on matter.Theconclusion which follows, that all the radio-elements expellinga-rays must give a small amount of y-radiation also, is supportedby very recent experiments, in which it was found that a veryrich preparation of ionium emits some y-rays, but no detectable&radiation. Three types of y-rays were distinguished, with thevalues of p / D in aluminium 400, 8.2, and 0.15 (cm.)-1. These, i tis concluded, are probably characteristic radiations of ionium orthorium in three different series. The value for the middle series,8.2, corresponds roughly with that found for the (( L ” series excitedin thorium by X-rays.26Further results with 8- and y-rays are more conveniently dealtwith in the sections Multiple Disintegration and y-zay Methods ofMeasurement .&Rays.The low velocity electrons emitted by surfaces under the impactof a-rays are of general interest, because their formation has beenrecognised as the analogue in solids of the process which in gasesresults in ionisation.Certain conclusions seem gradually to have been placed on afirm basis.The &rays appear to be emitted with a velocity follow-ing Maxwell’s distribution law for gas molecules. No definiteupper limit can be assigned to this velocity for the same reasonas in the case of the velocity of the gas molecules, but for the6-rays from a polonium-coated metal plate, velocities correspondingwith a fall of potential of as much as from 33 to 43 volts have beenrecognised.With a-rays from another source bombarding a metalplate, the maximum recognisable velocity of the b-rays corresponds25 J. Cliadwick and A. 5. Eussell, Nature, 1912, 90, 463.J. A. Gray, Proc. €by. Soc., 1912, A, 8’7, 489RADIOACTIVITY, 301with 15 to 20 voIts, and the most probable velocity with 6 volts.From polished surfaces the electrons can escape under their owninitial energy of motion, but with rough surfaces, such as thosecoated with soot, an electric field is necessary to assist them toescape.26 Certain conclusions that the &rays, when first produced,possessed no definite velocity, their velocity being acquired sub-sequently to their formation, have now been withdrawn27It has been proved that X-rays behave similarly to a-rays inproducing b-rays, and a detailed investigation has established thatit is the secondary &rays, which X-rays generate on impact withsolids, which produce the &rays.If surfaces struck by X-rays arecovered with paper, very few P-rays are generated, and theb-radiation is also suppressed. The b-rays so generated are in everyrespect identical with those produced by u-rays. The feature ofperhaps the most interest appears to be that the speed of theb-rays is independent both of the nature and temperature of themetal in which it is generated and of the nature of the excitingradiations, and is to be ascribed to some mechanism common to allionisation. The incident and emergent 6-particles produced bya-rays in passing through a thin sheet of metal are also alike inall respects.28Evidence has, however, been obtained that the layer of adsorbedgas on the surface plays a certain part in the production ofb-radiation.When such surfaces are exposed to a-rays in a highvacuum, the &rays generated diminish notably in quantity withlapse of time. No such “fatigue” is noticed with surfaces fromwhich the film of gas has first been removed.29 The characteristicsof the b-rays are, however, in no way different in the two cases,and it is impossible, however completely the gas film is removed,completely to prevent the emission of 6-rays. Indeed, the numberof &rays is only reduced by about 30 per cent., a figure which iswithin the variation in the number of ions produced by the samea-rays in different gases.As is well known,30 the curves connectingionisation and range of a-rays have different forms in differentgases, when gases of widely different density are compared.Whereas the analogous 6-ray-range curves 31 have, unexpectedly,the same form when surfaces so different in density as those ofaluminium, copper, gold, lead and platinum are compared. Theemission of b-rays is thus not four square in all respects with the26 Fr. Hauser, Physikal. Zeitsch., 1912, 13, 936; A , , ii, 1026.27 N. Campbell, Phit. Mag., 1912, [vi], 23, 462; 24, 527 ; A, ii, 411, 1027.2d N. Campbell, ibid., 23, 46, 462; 24, 527, 783 ; A , , ii, 221, 411, 1027, 1121.29 Pound, ibid., 23, 813 ; 24, 401 ; A,, ii, 514, 886.30 Ann. Reporf, 1907, 312 ; 1909, 287.31 Ibid., 1911, 281302 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.production of ions.That all is not known is shown by the recentdiscovery of a new radiation itself completely absorbed by a singlealuminium foil, 0.64 x 10-4 cm. in thickness, corresponding withan air equivalent of only 0.58 cm., which causes the emission ofb-rays from surfaces on which it is incident. It has been suggestedthat part, if not all, of the b-rays and of the ionisation producedby ionising radiations is due to the intermediate production of thisnew radiation.32 Doubtless it accounts for many of the difficultiesexperienced in the investigation of the subject (see also RadioactiveRecoil).X-Ra y s.Space must be allowed for a brief reference to the excitingdevelopments now in progress as a result of the discovery thatthe X-rays are capable of showing up the actual space-lattice ofa crystal as theoretically conceived by crystallographers.33 A platewas cut from a crystal of zinc-blende, parallel to a cube face, andperpendicular to one of the principal cubic crystallographic axes.A narrow beam of X-rays was directed perpendicularly through iton to a photographic plate.On development, the plate revealed anumber of light spots on a dark background. A t the centre wasa circular spot 0.5 cm. diameter, surrounded symmetrically bysixteen smaller elliptically-shaped spots, arranged iu a square,each side consisting of four spots separated by 0.5 cm., the cornersof the square being free from spots.Other fainter systems of spotswith similar cubic symmetry, parallel or diagonal with the first,appear. One is inside, and the others are outside and a t con-siderable distances from the main square. These spots wereascribed to an interference diffraction photograph of the space-lattice of the crystal.The activity which followed the original discovery of the X-rayshas been revived.34 It has been shown that the X-rays, ‘which, ofcourse, do not obey the ordinary optical laws of reflection, arestrongly and regularly reflected in accordance with these laws whenthey impinge on the cleavage planes of a crystal a t nearly grazingincidence. Crystals of rock salt and mica sheets have been used,and it is probable that this type of reflection, from the internalcrystal planes, accounts fully for the diffraction patterns of thespace-lattice obtained.It is almost certainly not surface reflection,a H. A. Bumstead and A. G. McGougan, Phil. Mag., 1912, [vi], 24s 462 ; A., ii,53 M. Laue, W. Friedrich, and P. Knipping, Sitzzcngsber. K. Ahad. Miinchat,Compare A. E. H. Tutton, Naluw, 1912, 90, 30;.34 W. H. Bragg, Xature, 1912, 90, 219, 360; W. L. Bragg, ibid., 410 ; C. G.1026.1912, 303, 363.Barkla and G. H. Martyn, ibid., 435RADIOACTIVITY. 303although a mica strip only 0.1 mm. thick reflects as strongly as athick crystal. By bending the mica into an arc, the X-rays canbe brought to a line focus. These discoveries cannot fail to exerta profound influence on the search for a theory, which shallembrace equally all the properties of light, X-rays and y-rays, andreconcile the conflicting aspects of the wave and corpuscularhypotheses.The Cloud Method of Re~izdering the Tracks of Rays Visible.This interesting new method, described last year,Jb has quitefulfilled the expectations that it would prove to be an exceedinglypowerful means of settling some of the most difficult questions asto the connexion between ionising radiations and the ionisationthey produce. A fine selection of photographs, comprising thetracks of u- and /%rays, and of the secondary 8- and cathode-raysproduced by beams of y- and X-rays, has been published, togetherwith full details of the vastly improved methods employed in theirproduction.36 In the first place, the whole clear conception of thenature of the a-rays, with their almost straight paths, their sharplydefined range, the increase of the ionisation as the ray penetratesthe gas and is slowed down, the columnar ionisation, the (‘single”and ‘( compound ” scattering, which previous researches have dis-closed, is shown to be accurate to the minutest particular in thesevisible records.Minor new points of great interest also appear.At the “ single scattering ’’ which usually characterises the end ofthe path, whenever the angle of deviation is large, a backwardshort extension of the new path, or (‘spur,” appears. This isprobably due to the atom which has been struck and which causesthe sudden abrupt deflection, itself acquiring sufficient energy toionise for a short distance.A t the beginning of the path of ana-ray, when it is possible to see the beginning, as in the a-rayexpelled from an atom of emanation, for example, an enlargedhead appears. This probably marks the ionisation due to therecoil-atom of radium-A , which, also, has been otherwise demon-strated by recent experiments.Likewise, with regard to the &rays, the general view as to theirionisation and scattering has been confirmed. It is possible to seeon the photographs the siugle pairs of drops corresponding withindividual pairs of ions, and even to count the number producedper cm. of path, with results in fair agreement with existing data.In addition to the regularly spaced pairs, clusters of 20 t o 30 dropsalso appear, which indicate that some of the atoms struck them-35 Ann.&port, 1911, 275.36 C. T. R. Wilson, Proc. Roy. SOC., 1D12, A, 81, 277304 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.selves liberate cathode-rays possessing energy sufficient to ionise forshort distances. The scattering is almost wholly of the cumulativeor compound type. Gradual and considerable curvature, ratherthan abrupt changes of angle, characterise the tracks of &rays soloiig as their velocity is high.The X-ray photographs show no trace whatever of directionisation apart from the secondary cathode-ray liberated from theatoms of the gas, and thus fully bear out the contention thatX-rays only ionise indirectly. These cathode-rays are of muchlower velocity than the P-rays of radium, and show both kindsof deflection, the gradual or cumulative deviation being muchthe more important factor in scattering.But abrupt deflections,often through 90° or more, also occur, especially a t the end of thepath. The cathode-rays start apparently in all directions, and norelation between these directions and that of the primary X-raybeam has yet been made out. The appearance of these photographsis that of a mass of interlaced fine threads, no one of which isstraight, all being both curved and bent characteristically. Onclose examination, and with enlarged pictures, the individual dropsof the clouds and the dotted appearance of the tracks are clearlyseen.Ionisa tion.That ionisation is not fundamentally atomic, but depends tosome extent on chemical combination, is recognised as one of thevery few points of contact between the new subjects dealt with inthis report and the older molecular sciences.Thus sulphur dioxideis a denser gas than hydrogen sulphide and absorbs X-radiation ofall degrees of penetrating power to a greater extent in consequence,yet the relative ionisation in layers of equal thickness is 1-24 timesgreater in the latter than in the former. I n a mixture of oxygenand hydrogen sulphide the ionisation is 1.17 times greater than ina mixture of hydrogen and sulphur dioxide of the same com-position.37 The variation in the number of ions produced indifferent gases by a-rays has long been recognised. A recent com-parison of the ionisation-range curve in mercury vapour a t 330°and 451 mm., with that of air a t the same temperature and a t apressure adjusted to make the ranges equal, showed that theionisation produced in mercury is nearly 40 per cent. greater thanin air.% Yet in these cases the molecular ionisation has beenrecognised as mainly, at least, an additive property of the atoms3’ C.G. Barkls and L. Simons, Phil. Mag., 1912, [vi], 23, 317 ; A., ii, 222.38 T. 5. Taylor, ibid., 24, 296 ; A., ii, 888RADIOACTIVITY. 305of the molecule,39 and not a constitutive property as in the caseof X-ray ionisation just cited.The number of pairs of ions produced by the single a-particle ofpolonium in air has been estimated to be 164,000, the mean energyabsorbed in producing one pair of ions, obtained by dividing theenergy of the a-particle by this number, being 5.3 x 10-11 erg.40The extraordinary results obtained from the study of positiverays in vacuum tubes, in which a host of novel types of molecularaggregations have been recognised,41 belong properly to the subjectof Gas Analysis, and cannot be dealt with in detail.Some interest-ing conclusions as to the true nature of ionisation are, however,put forward. The atoms in a molecule are probably not oppositelycharged. Thus, in a molecule of hydrogen or oxygen, the twoatoms are not charged respectively with positive and negativeelectricity. Each atom is, more probably, electrically neutral,containing equal numbers of opposite atomic charges of electricity.The chemical affinity is conditioned by the disposition of thesecharges with reference to one another.We may infer from thisthat a single bond holding two similar atoms in a diatomic moleculeis not well represented by the conventional symbol, but it neces-sarily double, such as might graphically be represented by 5o:nesuch symbol as:This is of interest because a molecule so constituted would possessone degree of freedom less than that with the conventional singlebond.An important paper dealing with the mathematical theory ofionisation by moving electrified particles can only be mentionedhere.42y-Ray Methods of Measwement,I n dealing with the radio-elements, the proportion of the elementin different preparations and therefore the relative atomic weightof the element can be determined exactly by methods for the firsttime essentially different from those so familiar in the cese ofordinary elements. I n the case of radium, f o r example, the ahinicweight, in terms of those of the other elements involved, couldbe obtained with fair accuracy by y-ray measurements without asingle weighing on a number of different compounds, such as thechloride, bromide, carbonate, and so on.y-Ray measurements3@ Ann. a p o r t , 1907, 314. 40 Phit. Mag., 1912, [vi], 23, 670 ; A , , ii, 412.41 Sir J. J. Thonison, ibid., 24, 209 ; A., ii, 885.43 Ibid., 23, 449 ; A., ii, 410.REP.-VOL. IX. 306 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.would invariably be employed, by preference, because theabsorption of y-rays in the substance itself can readily bearranged to be negligible.Thus, y-ray measurements andthe accuracy that can be attained through them are of con-siderable interest. A t Paris in the comparison of the radiumstandards two main methods were employed. In one,43 the radiumtube was placed on the centre of a large horizontal circular plateof lead, 1 cm. thick, which formed the upper plate of a condenser,the distance between the plates being only a few centimetres. Theupper plate was connected to one pole of a battery of 800 volts,the other pole of the battery being earthed, and the lower plateis connected with the one pair of quadrants of an electrometer,the other pair being earthed. A t a given moment an earthconnexion of the lower condenser plate is broken, and the ionisationcurrent between the condenser plates is exactly neutralised by theCurie quartz electric balance, in which a weight of several kilo-grams, held in the hand of the operator, is gradually applied tothe pan of the instrument so as to keep the needle of the electro-meter as near zero as possible.With practice this apparentlydifficult operation can be accomplished with marvellous precision.As soon as the full weight is applied, the needle swings away fromthe zero off the scale, and the time is taken. The weight employeddivided by the time gives the relative measure of the strength ofthe y-rays. The absolute measure of the ionisation current can,if required, be readily deduced from the constant of the electricbalance, and does not involve the capacity of the system.In the second method44 a form of optical bench was employed,a t one end of which a small, shallow, cylindrical ionisation chamberof lead was mounted with the axis parallel to the bench, the radiumpreparations being supported in the line of the axis on a lightaluminium stand sliding on the bench.The ionisation currentdue to the y-rays of radium was balanced against the ionisationcurrent due to a surface of uranium oxide, kept constant duringthe comparison. Balance was obtained by sliding the radiumpreparation along the bench. In comparing two radium pre-parations X and P, if A and B denote the balance distancesrespectively, measured to the inside surface of the nearer end ofthe ionisation cylinder, and I is the length of the cylinder, theratio of the two preparations X/ P =B(B + Z)/A(A + I ) .Thisratio is subject to a very small correction for the different absorptionof the y-rays in the air a t the two distances.The two methods gave concordant results with the various radium‘3 A. Debierne, Le Badium, 1912, 9, 169.4 E. Rutherford and J. Chadwick, Proc. Physical Soc., 1912, 24, 1-41 ; A., ii, 520RADIOACTIVITY. 305standards employed, and the error of measurement was estimatedas certainly less than 3 parts in 1000. As an example, the numbersfound for the 31.13 and 10.11 milligram Vienna standards bycomparison with the Paris standard were, in single determinations,31.24 and 10.13. I n absence of other substances giving y-rays,the quantity of radium in a sealed tube can now be estimatedwithout opening the tube with a t least an accuracy of 0.3 per cent.The second method has been used to measure the absorptioncoefficient of y-rays of radium in gases and light substances.45 Thevalues of p / D , where p is the absorption coefficient and D is thedensity, for y-rays after traversing 0.3 cm.of lead are 0.048,0.051, and 0.047 for air, carbon dioxide, and hydrogen respectively,and for the first two for y-rays after traversing 1 cm. of lead,0.046 and 0.047. For air at Oo and 760 mm., .the value givenfor p is 0-0000624.46 The ‘‘ average path” of the y-ray in air isthus about 150 metres. For a great variety of substances of widelydifferent densities, from that of wood to that of lead, p / n variesfrom 0.0401 t o 0.0599, and has a minimum value for substancesof intermediate density.It is greater both for lighter and heaviersubstances, the difference being the more pronounced the lesspenetrating the y-rays employed, as found previously.I n another research the absorption coefficient of the &rays ofradium in air has been directly measured.47 For radium pre-parations sealed in glass test-tubes and for short ranges, 0.6 t o1.6 metres, of air, p is 0*0033(~m.)-~, and for longer ranges, 2 to5 metres, 0.0045. The value obtained for the y-rays was, however,less than half that given above. The interesting and possiblyimportant observation was made that, for the &rays from a baresurface of radium active deposit, the value of p, is about 0.012.This value does not alter with time, when the proportion ofradium-C t o radium-B is increasing in the active deposit.Thisindicates that radium4 as well as radium-B emits a considerableproportion of very easily absorbed &rays.Solutions have been published of some important mathematicalproblems in the absorption of y-rays in materials of various form.48Helium and Neon.In an investigation of the mineral waters of the King’s Well,Bath, the interesting observation was made that the proportions45 J. Chxdwick, Le R d i ~ n ~ , 1912, 9, 200 ; A., ii, 718.46 Compare also V. I?. Hess, Xitzungsber. K. Aknd. Wiss. Wien, 1911, 120, IIn,1205, where the valne found for p was 4-47 x 10-5(cm.)-1.47 A.S. Eve, Trans., Roy. SOC. Canada, 1911, 5, iii, 59 ; A , , ii, 717.H. Thirring, Physikal. Zeitsch., 1912. 13, 266. E. v. Schweidler, ibid., 453.L. V. King, Phil. Mag., 1912, [vil, 23, 242.x 308 ANNUAL REPORTS ON THE PROGRESS OF CREMISTRY.of argon, neon, and helium therein differ notably from theatmospheric proportions, and that hydrogen and oxygen are absent.There is 0.78 times as much argon, 188.1 times as much neon, and72.8 times as much helium as in the same volume of atmosphericair. The water contained 1.73 x 10-9 curie, and the evolved gas33-65 x 10-9 curie of emanation, t u t only 0*14xlO-g gram ofradium was present in the water, per litre.49The absence of oxygen and hydrogen, such as might be expectedfrom the radioactive decomposition of the water, and the greatpreponderance of neon is taken as indirect evidence that neon isproduced by the action of the emanation on the water.Neon insuch a quantity, however, is an exceptional constituent of mineralspring gases, whereas radioactivity of the degree of the Bathwater and higher is comparatively common.Neon, together with helium, was found to be present in thegases produced from a solution of thorium nitrate, which had beentreated with several quantities of radium emanation. The coldcharcoal method of separating the helium a.nd neon was employed,whereas a chemical reagent, such as lithium or calcium, which doesnot absorb the atmospheric argon, if present, is to be preferred incases where the origin of a small quantity of neon is a t issue.Theunabsorbed gases had a volume of 0.485 cu. mm., and the spectrumshow both helium and neon brilliantly. It was judged from theappearance of the spectrum that from one-third to one-fourth, thatis, about 0’177 cu. mrn., consisted of neon. The gases absorbed inthe cold charcoal were treated for argon, but hardly any wasrecovered. The conclusion was arrived a t that the air-leakage wasinsignificant, and that the neon must have been produced by theaction of the emanation on the solution.The conclusion, however, is hardly borne out by the evidence.For it was found that 0.5 C.C. of air, which contains 0.006 cu. mm.(not 0.06, as stated), gave a spectrum ‘(comparable in brilliancywith, but not so brilliant as, that of the neon separated from thegases of the thorium solution,” which from spectroscopicexamination had been adjudged to contain 0-177 cu.mm. of neon.I n a preliminary communication 60 it is stated that neon has beenobtained by bombarding fluorite, prepared by precipitation, wash-ing, and heating to dull redness, with cathode-rays in a tube towhich oxygen is admitted as required to maintain the pressure a tthe value best suited for the production of cathode-rays. Thesurface turns purple, and silicon fluoride, oxygen, and carbon49 Sir William Rainsay, Chem. News, 1912, 105, 133 ; A . , ii, 417 ; T., 1912, 101,1367. J. I. 0. Masson and Sir W. Ramsay, ibid., 1370.Sir William Ramsay, Nature, 1912, 89, 502RADIOACTIVITY. 309monoxide are expelIed.The gases evolved during the first fewdays were rejected, and tbe fifth quantity pumped off was examined.After absorption of the condensable gases by cold charcoal, theresidue was pure neon, withollt a trace of helium.Researches on the proportion of the rare gases in French naturalsprings show that, with the exception of helium, the other membersof the family occur in proportions of the game order as in theatmosphere. The conclusion, with regard to neon, is, however,provisional only, owing to the difficulty of accurately estimatingthis constituent. The springs of the CGte d’Or contain 10 percent. of helium in the nitrogen and rare gas fraction, whilst theSource Carnot a t Santenay is equally rich, and is estimated t oyield 17,845 litres of helium annually.51 The question arises as tothe origin of this helium, for the quantity furnished by the SourceCarnot requires for its steady annual production some 70,000 kilos.(about 70 tons) of pure radium, equivalent to some hundreds ofmillions of kilos.of rich uranium minerals. The same questionarises with regard to the natural gas in certain parts of America,several of which are stated to contain over 1 per cent. of helium,62which must be evolved in enormous quantities.Tiiermo-radioactivity .With the large quantity of radium chloride of definite puritypossessed by the Radium Institute of Vienna, determinations havebeen made of the heat generated and other constants. Underconditions in which the whole of the a- and &radiation and anestimated fraction of 18 per cent.of the y-radiation were absorbedin the calorimeter, the heat generated per hour per gram of radiumchloride was 100.66 calories, or per gram of radium, 132.26 calories.These figures refer to radium in equilibrium with its first fourshort-lived producfs.53 The energy of the rest of the y-rays wouldincrease the figure by an amount, still somewhat indefinite, butprobably from 3 to 5 calories per gram of element. The valuesagree so well with the figures calculated from the known data asregards the kinetic energy and number of the a- and @-particlesand of the recoiling atoms, that the very important conclusion isarrived a t that no appreciable part of the energy of the radiationescapes transformation into heat.No appreciable part, that is tosay, is absorbed in doing any other kind of work than that involvedin raising the temperature of the surrounding matter.A further determination of the heat generated by radium, freed51 C. Moureu and A. Lepape, Conapt. rend., 1912, 155, 197 ; A., ji, 833.5L Ann. Beport, 1907, 323.53 St. Meyer and V. F. Hess, Monatsh., 1912, 33, 683 ; A . ii, 716310 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.from all its disintegration products,54 gave the value 25.2 caloriesper gram of radium per hour, and, as in this case there is nopenetrating radiation, the figure is definite. This leaves 107.1calories for the heat generated by the emanation, radium-A, -B,and -C, under condifions such that the whole of the a- and Praysand 18 per cent.of the y-rays are absorbed. What must be con-sidered as a truly remarkable result is that this figure, 25.2 calories,agrees within 1 per cent. with the value calculated from Joule'sequivalent, and the number, mass, and kinetic energy of thea-particles expelled from radium, taking into account the energyof recoil, and assuming that the whole of the kinetic energy sufferstransformation into heat.An independent analysis of the heat in calories generated perhour per gram of radium in equilibrium with its first four productsis given in the following table as the result of an exhaustiveexperimental investigation with the radium emanation and itsproducts, interpreted in the light of the other data applying tothese products.66a-Rays.&Rays. ?-Rays. Total.Radium ................. 25 -1 - 25 -1Emanation.. ............. 28.6 - 28.6Radium- A ............ 30.5 - 30.5Radium-B + -C ......... 39'4 4.7 6'4 50 *5Total ............ 123 '6 4.7 6-4 134'7- --The heat from a tube containing a given quantity of radiumemanation in equilibrium with its products was first measured, theemanation was removed as quickly as possible, and from the changewith lapse of time in the amount of heat generated, it was deducedthat of the total heat 29, 31, and 40 per cent. respectively camefrom the emanation, radium-A and radium-B+-C. From thevelocities of the various a-rags, the proportion should have been28.8, 30.9, and 40.3 per cent., but taking into account the factthat probably about 4 per cent.of the total energy is due to0- and y-rays which come from radium-B and -C only, the heatgenerated by radium$ appears somewhat less than theory indicates.Whether this small difference is significant remains to be seen.On the assumption that the heat effects are proportional to theionisation produced by the rays, an attempt was made to estimatethe proportion of the total heat due to p- and y-rays, and fromthese experiments the figures in the table are deduced. They differfrom preceding estimates 66 in the increased proportion ascribed tothe &rays. This is because the measurements were done in theF*l V. F. Hess, Sitzungsber. K. Akad. Wiss. W i e n , 1912, 121, IIa, 1419.65 E. Rutherford and H. Robinson, ibid., 1491.56 Ann.&port, 1911, 283RADIOACTIVITY. 311special glass tubes capable of allowing even the a-rays to escape,whereas in ordinary tubes, even the thinnest, a large proportionof the softer @-radiation is absorbed.It is estimated that the polonium in equilibriuni with 1 gramof radium will generate a further 25.86 calories per hour, theamount produced after one year's accumulation being about1 calorie per hour. The calculated saturation current (in termsof E.S.U. x 106) from a gram of radium, free from products, in theform of an infinitely thin film so that there is no absorption, is1-28 (when half of the radiation only escapes to produce ionisation),whereas that experimentally found was 1.22. The total saturationcurrent calculated for 1 curie of emanation in vessels of infinitedimensions is 2.75, and for the emanation together with its productsof rapid change, 6-10, these figures agreeing closely with the variousexperimental determinations, extrapolated to correspond withvessels of infinite dimensions from the formula of Duane andLaborde.57 It is clear that the standards of radium employed inthe past by different investigators do not differ very widely fromthat adopted as the International standard.58A determination of the heat generated by a specimen of orangite,estimated by a radioactive method to contain 36 per cent. ofthorium, gave in two series 25.4 and 19.4 ( x 1 0 - 5 calorie per gramper hour), which is about ten times that found for thorium oxideby other observers, and is greatly in excess of that indicated byradioactive theory.Possibly some chemical change in the materialmay have caused the result, but until the repetition of the experi-ments now in progress is complete, discussion may be reserved.59Multiple Disintegration.Thorium-C or -C, and -C,.-The most definite case of multipledisintegration a t present appears to be that of thorium-C. Adopt-ing the view that each mode of a dual disintegration obeys the lawof a single radioactive change as though the other mode did notoccur, at rates indicated by the radioactive constants A, and A,respectively, the parent substance divides itself so that the fractionh1/hl + A, disintegrates according t o the first mode and the fraction]\z/hl + according to the second.The radiation decays exponen-tially according to the equation I = 1,e - ( A i + W , independently ofwhether the rays result in both modes or in one only of the twomodes of disintegration.6057 A m . Rcport, 1910, 256.58 H. Itlache and St. Meyer, Physikal. Zeilvch., 1912, 13, 320 ; A . , ii, 580.Mcyer and V. F. Hess, Monalsh., 1912, 33, 588 ; A., ii, 716.59 H. H. Poole, PhiZ. Mug., 1912, [vil, 23, 183.60 F. Soddy, ibid., 1909, [vi], 18, 739 ; A., 1909, ii, 952.St312 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.If A, and A, are quantities of the same order, as appears to bethe case with thorium-C, the process is much easier to follow experi-mentally than if A, and h2 are of widely different value, as appearsto be the case with radium-C. From t.he general manner in whichthe radioactive constants vary widely from member to memberand from series to series over an extreme range at present knownof 1 : 103O, it is to be expected that the cases in which A, and h2happen to be similar will be few in comparison with those in whichthey are widely different.There is little doubt that many of thscases of disintegration a t present regarded as simple may proveon closer examination to be multiple, with A, and A, widely different.A single parent element may thus give rise to many end-productsvarying enormously in relative amount, the ratio A,/A, fixing alsothe ratio of the relative amounts of the two end-products in a dualdisintegration.For every 100 a-particles given by the thorium emanation, 100are given by thorium--4, whilst 35, of range 4-55 cm., and 65 ofrange 8.16 cm.are given by thorium-C, indicating that thorium-Cundergoes a dual disintegration with hl / %= 35 / 65 .61 In the caseof the a-particles of range 8-16 cm., the period estimated by theGeiger-Nuttall relation is 10-11 second.Thorium-C disintegrates according to an exponential law withperiod of average life 1 / ~ = 7 9 minutes, so that, on the viewtaken, l / A l + A,= 79 minutes, and the separate values of h, andA, would be 225.7 and 121.5 minutes. It is these separate periodsand not the apparent period which would fix the range of anya-particles emitted in the changes. The first period agrees wellenough with the range (4.55 cm.), but it is clear that the longerrange a-particle (8.16 cm.) must come from a change with periodof the order of 10-11 second, and this change must follow the121.6 minutes period change of thorium-C.In the first place, very numerous attempts to detect any lack ofhomogeneity in thorium-C were unsuccessful.Under all circum-stances, the 35/65 ratio between the two sets of a-particles holdsgood, and this is maintained unaltered as the radiation decays.Thorium-C, which had been separated by recoil from the activedeposit, by volatilisation a t various temperatures and by immersingplates of various electrochemical potentials in the solution of theactive deposit, always gives this same ratio. Similarly, when veryshort exposures to the emanation were given, the active depositbehaved normally, the a-radiation rising to a maximum in twohucdred and twenty-five minutes, and maintaining the ratiobetween the two sets of a-particles unchanged.All this is evidence61 T. Bnrratt, Proc. F'h.gslsicn2 sbc., 1912, 24, 112 ; A . , ii, 408RADIOACTIVITY. 313that thorium-C is a homogeneous type of matter, the atoms ofwhich can disintegrate in two distinct ways.62 Just aa, accordingto present ideas, there is no inherent difference recognisable betweenatoms of the same radio-element which are about to disintegrateimmediately and those which are destined to survive possibly severaltimes the period of average life, the selection following the laws ofprobability, so in thorium-C there seems to be no recognisable differ-ence between those atoms which will expel low-range u-rays (C,)and those which will expel high-range u-rays (Cz), the laws ofprobability controlling the number following each mode as thoughit alone took place.A most interesting point has, however, transpired.Per atom ofthorium-C disintegrating one and not two a-particles are expelled,and therefore one &particle also is expelled.63 I f thorium-D were,%or I urn 3eries.as previously supposed, the product solely responsible for the &rays,and if i t gave, as in other cases, one &particle per atom disintegrat-ing, it would follow that thorium-D must result from both modesof the disintegration of thorium-C. This means that the series afterbranching must join together again, which is in the highest degreeimprobable.A closer examination has brought to light the follow-ing new facts. All the y-rays, but only a portion, the relativelysmaller portion, of the &rays, come from thorium-D. The greaterpart of the B-rays, some 65 per cent., come from thoriumC, and areunaccompanied by y-rays. The &rays expelled by the C memberare considerably swifter and more penetrating than those expelled62 E. Marsden and C. G . Darwin, Proc. Roy. Soc., 1912, A, 87, 17 ; A., ii, 823.63 Ann. Report, 1911, 282314 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTHY.by the D-member. Hence it is reasonably concluded that thedisintegration runs as shown in the diagram on p. 313.The three circles lettered C refer to the same substance, disin-tegrating dually, both modes of disintegration proceeding simul-taneously, not successively.The hypothetical, shortclived parent ofthe 8.16 cm. range a-ray has been designated C" for want of abetter term. The periods refer to the periods of average life. Thefacts as regards the 8- and y-rays are well established by entirelyindependent investigation^.^^ The mixed &rays of thorium8 + -Dare half absorbed in 0.41, of pure -D in 0.32, and of pure -C (calcu-lated) in 0.48 mm. aluminium. The &ray curve of pure thorium-Crises from an initial value 0.72 to a maximum, reckoned as unity, inten minutes, whereas the y-rays rise from an initial value of only0.06 to a maximuin in fourteen to sixteen minutes.Thus the dual disintegration of thorium47 occurs either as anu-ray or a &ray disintegration.I f the a-ray is first expelled, theproduct gives P- and y-rays, whereas if the &ray is first expelledit is unaccompanied by y-rays, and the product disintegrah withimmeasurable rapidity, giving a-rays. Here we have evidence forthe first time of penetrating l3-rays unaccompanied by y-rays.Evidence, however, has been published of a partial separation bychemical methods of thorium-C into two numbers responsible forthe two kinds of a-radiati~n.~S I f this is correct, it completely upsetsthe preceding explanation. Since the evidence is indirect, and allthe details of the methods of separation are not fully stated, it may,theref ore, be left over, witshout prejudice, for subsequent considera-tion, when fuller evidence is forthcomiDg.The explanation hereadopted fits all the known facts provided thorium-C is homogeneous.Should it prove separable into distinct products, -C, and e2, thenthe dual disintegration must occur earlier, for example, a tthorium-B. But in this case thorium-C, and -C2 must have the sameperiod. Otherwise, the a-radiation would not decay exponentially.The relative number of a-particles emitted by the successive pro-ducts shows that a dual disintegration does occur.In the whole thorium series six u-particles are expelled per atomof thorium; the calculated atomic weight of the end-product istherefore 232.4 - 23.94 = 208.46, and the nearest known atomicweight is that of bismuth. Two end-products, however, with thesame atomic weight in the ratio 35 : 65 must 'result, if both branchesof the series end as the diagram shows.Badium-C, and -C2.-There is not much new experimental evidence64 E.Ifarbden and C. G, Darwin, Zoc. c l t . 0. Hahn and L. Meither, PhgsikEnZ.65 L. Meitner, PhysikaZ. Zeitsch., 1912, 13, 6 2 3 ; A., ii, 723. Compare alboZ~zlsch., 1912, 13, 390 ; A,, ii, 514.von Hevesy, PhiE. Mag., 1912, [vi], 23, 628; A . , ii, 414RADIOACTIVITY. 315in the case of radium-C, but an explanation analogous to that ofthe thorium dual disintegration may be put forward.66 I n this casethe name radium-C, has, unfortunately, been applied to a distinctproduct, of period of average life 1.9 minutes giving &rays, but nota-rays, separable in very small quantity only by recoil fromradium-C, that is, from the complex product of period 28.1 minutes,giving a-, /3-, and y-rays.At first the minuteness of the quantityrecoiled was attributed to the substance being produced by a &raychange. But in other &ray changes, for example, that of radium-E,no trace of the product has been observed to recoil. Adopting theview that the relative minuteness of quantity of radium-C, is realand not merely apparent, it appears that radium-C undergoes adual disintegration with the ratio hl/h2 about 3/10,000. That is,some 3 atoms out of every 10,000 of radium4 may be supposed to-0 28.1 rninRadrum Seriesdisintegrate, with expulsion of an a-radiation, of a range which canbe calculated to be about 3.9 cm., but which has not yet beendetected, producing radium-C2, which then expels &rays, andpossibly y-rays also.The remaining 99-97 per cent. of the atomsexpel j3- and y-rays, and produce a product of estimated period10-6 second, which on disintegration gives the long range a-raysand produces radium-D. In the diagram the hypothetical shortrlived product has been termed " C'," but it is clear that the wholenomenclature needs to be recast if it should be proved that thethorium and radium series are analogous. These diagrams mayprove to be premature. At least, they are interesting.Evidence in favour of the real relative minuteness of quantityK. Fajans, Physikal. Zeitsch., 1912, 13, 699; A . , ii, S24316 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.of radium-C, is obtained from the study of the time-b-ray curves ofpure radium-B, in which the proportion of 8-rays contributed byradium-C2 was too small to be detected.67Incidentally, these experiments confirmed the conclusion ofSchmidt, which had been called in question, that radium-B emitssome penetrating P-radiation.About 1.5 per cent. of the ionisationis due to &rays [p = 13(cm.)-lAl], identical with those of radium-C,the remainder being due to the @)-rays [ p = 91 (cm.) -lAl] commonlyascribed to radium-B. No evidence of still softer rays (p.890)found by Schmidt was obtained.Following this up, it was found that radium-B also emits y-rays,and 12.7 per cent. of the ionisation produced by the y-rays ofradium-B and -C in equilibrium were found to be due to radium-B.The absorption-coefficient in lead between 0.3 and 0.6 cm. was4 (cm.)-l, and between 0.97 and 1-72 cm., 6 (crn.)-l.These y-raysare thus of very feeble penetrating power compared with those ofradium-C, and through 2.3 cm. of lead no y-rays due to radium-Bcould be detected.Radioactive Recoil.A recoiling atom possesses some fifty times the mass and one-fiftieth of the velocity and energy of the a-particle from which itrecoils, but, like the u-particle, it appears to be capable of ionisingthe molecules of the atmosphere in which it is produced.68 Probablyrecoil atoms constitute part of the new radiation referred to atthe end of the section &Rays. I n the case of radium-C, the energyof the a-particles is very great, and the recoiling atoms of radium-Dpossess a “range” one-five hundredth of that of the a-rays ofradium-C, or about 0.14 mm.of air at atmospheric pressure. Atdistances within this from a surface of radium-C, the recoiling atomsof radium-D produce five times as much ionisation as is producedby the a-rays. The fraction of the total ionisation contributed bythe recoiling atoms is, however, less than 1 per cent. So far ascan yet be seen, the ionising power of the recoil atoms diminishesas the distance traversed in the gas increases, which is the converseof the law holding for a - r a y ~ . ~ ~Similar experiments with polonium (Ra-F), from which the stillunidentified and hypothetical end-product of the series must recoil,were unsuccessful until a preparation of the requisite degree ofpurity was prepared to give a layer thin enough (less than 10pp) toallow the recoil-atoms to escape.Then the ionisation due to the67 K. Fajans and V;. Makower, Phil. Mag., 1912, Ivi], 23, 292 ; A., ii, 220.6a Ann. aport, 1910, 273.69 L. Wertenstein, Le Radium, 1912, 9, 6 ; A., ii, 222RADIOACTIVITY. 317recoiled atums became manifest, and the range was estimated as7 cm. in air a t 1 mm. pressure, or rather less than 0.1 mm. atatmospheric pressure. The ratio of the ranges of the recoil-atomsof Ra-C and Ra-F are nearly the same as the ratio of the rangesof their a-particles.70 This is the first experimental evidence of theexistence of an ultimate product of a disintegration series, asrequired by the theory.The absorption of recoil-atoms in passing through a gas has beeninvestigated in the case of radium-C.The range of the recoilingatoms of radium-B is 10.5 cm. in air a t 1 mm. pressure. Hydrogenat 6 mm. pressure is equivalent in every respect to air a t 1 mm.I n air a t 1 mm. the diminution of the number of atoms in acanalised stream of recoil-atoms is unimportant for the first 5 cm.,and then increases rapidly t o the end of the range. In hydrogen at6 mm. the diminution is much more abrupt, the lighter atoms ofhydrogen probably scattering much less than in the case of air. I neach case the ionising power of the recoil-atom diminishes alongits path, but the diminution is much more rapid in air than inhydrogen.The amount of recoil product (actinium-D w'as the productstudied) collected on a negatively charged surface is diminishedby intense ionisation of the gas.The recoiling atoms behave inthis respect like positive ions. Increase in the concentration ofthe ions in the atmosphere increases the chance of their recombina-tion with ions of opposite sign before they arrive a t the electrode.71ZnfZuence of Temperature on Radioactive Changes.The Existence of Chemical Compounds of Short-livedRadio-elemen ts.A complete explanation has been obtained of the small changesin intensity of the less penetrating types of radiation during theheating and cooling of tubes containing the radium emanation andactive deposit.72The effects are not a t all due t o real changes in the radioactivity,but to alteration of the position of the radiating materials withrespect to the measuring instrument by volatilisation and condensa-tion, whereby the mean distance of the source of rays from theinstrument and the fraction of the radiation absorbed by the wallsof the containing vessel is altered.73 Thus, if a spherical bulb isemployed it can readily be understood that the absorption of the70 B.Bianu and L. Wertenstein, Compt. rand., 1912, 155, 4 i 5 ; A., ii, 887.T1 A. F. Kovarik, Phil. Hag., 1912, [vi], 24, 722 ; A., ii, 1121.72 Ann. Repod, 1910, 273.73 A. S. Russell, Proc. Roy. Soc., 1912, A, 86, 240 ; A., ii, 416318 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.radiation in the walls must be less, if the active matter is all in thestate of gas, than if it is all deposited uniformly on the walls.I nthe latter case a greater proportion of the rays reaching an externalinstrument are tangent to the surface of the bulb, and thereforehave paths passing through a maximum thickness of the wall.Surprising variations occur, however, in the degree of volatilityof the various numbers of the (‘ active deposit ” groups in differentexperiments, which were traced to the nature of the atmospherein which volatilisation took place.74In a vacuum, actinium-B, deposited on a surface of platinum orquartz, begins to volatilise a t 600°, and volatilisation is neaflycomplete at 900°. I f the deposit is first exposed to various gaseousreagents, such a6 chlorine or hydrogen iodide, its volatility isincreased.Hydrogen chloride, whilst not affecting the volatility,increases the amount of actinium-B which can subsequently be dis-solved by water, the actinium-C being hardly at all soluble underthese conditions. I n experiments in which a long mica strip wasinserted in a tube hotter at one end than the other, a wire coatedwith actinium-B being placed a t the hot end, condensation of thevolatilised actinium-B occurred in air mostly a t places heated above1000°, but in hydrogen the maximum amount was deposited on thesurface at a temperature becween 615O and 675O.Similarly with the radium active deposit, in hydrogen volatilisa-tion of all three products, radium-A, -B, and -C, is complete a tabout 650°, but in an atmosphere containing oxygen no volatilis&tion of radium4 occurs below 1200°, and neither of the threeproducts is volatile below 700O.In hydrogen volatilisation ofradium-C commences even a t 360O. For this substance there isthus a difference of 800° in the volatilisation temperature inhydrogen and oxygen respectively.75These remarkable differences point strongly to the existence ofdifferent chemical compounds of these short-lived radioelements ;thus in hydrogen the substance may exist in elementary or metallicform, which is relatively volatile compared with the oxide formedin presence of oxygen. The whole direction in which the subjectis moving shows that it is by no means so impossible as appears atfirst sight to investigate the chemical nature of these ephemeralsubstances, although they only exist in quantities below themillionth of a milligram.74 H.Schrader, PJriZ. Mag., 1912, [vi], 24, 125 ; A . , ii, 722.i5 A. S. Russell, ibid., 134 ; A., ii, 723RADIOACTIVITY. 319Electrochemistry of the Radio-elements.The foregoing remark applies aptly to the electrochemistry ofthe radio-elements, for in this subject a standing reproach has beenthat the theory often deals with concentrations entirely beyond therange of verification, as is instanced, for example, by the electro-chemical determination of the solubility of almost insoluble sub-stances. Applied t o the radieelements of short-lived period inwhich a detectable radioactivity is associated with a billionth of amilligram by weight, the electrochemical theory leads to the resultthat such substances should be deposited from solution in detectableamounts by differences of potential far below the decompositionvoltage.In a neutral solution some detectable quantity of a shortrlived radio-element should be deposited on any metal, and thistheoretidal deduction has been verified for all metals, including thenoble metals gold and sirver, in the case of fifteen separate short-lived raclio-elements.76Using concentrations of the order of 10-16 g. p0r c.c., the v a r ktion of the ratio in which the -B and -C members of the seriesdeposited was investigated, as the electrochemical potential of themetal was varied from the cas8 of silver in silver nitrate solution,where the metal is positive t o the solution, to that of zinc in zincsulphate, which is negative.I n the first case the C-member isdeposited almost pure, but as the potential of the metal decreasesand changes sign the B-member is deposited in increasing quantityuntil it is in excess of the equilibrium ratio. The B- and C-membersof the three series exhibit identical electrochemical behaviour, andare deposited in equilibrium ratio when the metal is 0.63 voltnegative to the solution.Not the least interesting development was a radioactive methodof determining single electrode potentials, for which electrochemicaltheory cannot be directly tested, from the ratio of the -B and -Cmembers deposited, and the known variation of this ratio with theP.D.actinium-B and -C furnishes the quickest, and thorium-B and -Cthe most accurate indicator for this purpose, radium-B and -C beingunsuitable. The ratio is deduced from the a-ray decay curve of thedeposit; thus for a copper electrode immersed in pure water forone minute the potential difference between metal and solution was-0*7V., a-nd for an immersion of 0.2 second, -2V. With longerimmersion the normal electrochemical potential of copper isapproached. These are beautiful illustrations of how deductionsfrom the theory of solution pressure in cases where the ionicconcentration of the metal approaches zero may be tested.7776 G. von Hevesy, Phil. .Wag., 1912, [vi], 23, 628 ; A., ii, 414.77 G. von Hevesy, Phpsikal. Zeikc?h., 1912, 13, 715320 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Von Lerch's general method of separating the -C member fromthe -B member in a pure state by deposition on nickel dependspartly on the abnormal negative potential of the nickel electrode,which is connected with its passivity, and on the use of an acidsolution in which the -B member deposited is preferentially dis-solved.In the three series radium-C is the easiest and thorium-Cis the most difficult to separate from the -B member in the purestate, whereas from the molecular equilibrium ratio in the threeseries, actinium-C should be t h s most difficult of the three. Thisanomaly would be explained if thorium-C really consisted of twoseparate substances, C, and C,, of which only the one, C,, givingthe.shorter range a-rays and present in less proportion, is analogousto the other C-members. The point is, however, too crucial t o besettled by such indirect evidence.To nium .Homogeneity o f Chemical Elements.The results of experiments that have been in progress over thepast s v e n years on the growth of radium from large quantities ofuranium in solution purified in various ways have recently beencollected and discussed.78 A minute growth, which, expressed inunits of 10-12 gram of radium per kilogram of uranium per year,varied from 12.4 for the first t o 2.0 in the last quantities purified,was observed in all the uranium preparations, but, so far as canbe seen, it is proportional to the time and is due to minute tracesof ionium originally present.No indication of an increased rateof growth of-radium, such as must occur if ionium in appreciablequantity was forming during the time of observation, has yet beenobserved. It may be calculated that, if ionium is the only long-lived intermediate substance in the series between uranium andradium, its period of average life must be a t least 100,000 years,which is forty times longer than that of radium, and the quantityin uranium minerals must be a t least 12'3 grams per 1000 kilos. ofuranium. The total quantity of ionium and thorium together inJoachimsthal pitchblende is such that the maximum estimate forShe period of ionium can hardly b0 greater than a million years,and has recently been estimated by this method on certain assump-tions to be not more than 250,000 to 300,000 ~ears.7~ These esti-mates are supported by the failure to detect the growth of ioniumfrom uranium-X, the product of which remains experimentallyunknown.80 They all involve the assumption that no unknown7* F.Soddy, Royal Institution Lecture, Mnrch 15th, 1912 ; Xnlurc, 1912, 89, 203.70 St. Meyer and V. F. Hess, Sitzrcngsber. K. Aknd. Wiss. Wiea, 3912, 121, 11. ;d., ii, 603.Ann. Report, 1909, 262RADIOACTIVITY. 321intermediate substances of long life intervene, On the other hand,the period of 200,000 years, estimated from the range of the ioniuma-particle (p. 294), does not involve this assumption, and is ingood agreement with the other estimates.The question, whether unknown long-lived intermediate membersof the series still remain to be discovered, has, however, been raisedin an acute form by the failure t o detect, in the arc spectra of thestrongest ionium-thorium preparations, a single new line due toionium.81 Such preparations, from the intensity of their a-radia-tions, must contain more than 10 per cent.of ionium if the periodis 100,000 years, and, it is reasonably certain, should show at leastsome of the lines of the ionium spectrum. The strongest line ofthe radium spectrum can be detected in a barium preparationcontaining only a few parts of radium in a million. Not a singleunknown line has, however, been observed. I n one investigationin addition to the thorium spectrum, only five of the stronger linesof scandium were observed.In the other investigation, cerium,scaiidium, yttrium, and some of the rare earths were detected. Itmay be mentioned that the proportion of ionium and thorium in apreparation of the oxides is not affected by heating in the electricarc.The com-plexity of “uranium” and the view that it consists of two non-separable elements, uranium-Z and uranium-ZZ, differing in atomicweight by four units, raises the question whether uranium-X, theproduct of “uranium,” is the product of uranium-Z or ofuranium-ZZ. There is really no experimental evidence whatevercapable, at present, of deciding between the two alternativeschemes :Ur-I -> Ur-11 --P+ Ur-X -!+ 10 -> etc.Ur-I-> Ur-X -!+ Ur-II -> 10 > etc.An interesting line of thought may now be pursued.Hitherto, the first has always been assumed, but the second ismuch the more probable.For the first scheme is an exception tothe rule that the expulsion of an a-particle reduces the valencyby two units, the step being always from the family of evenvalency into the next, the family of odd valency being alwaysmissed.82 The second scheme not only conforms to this rule, butexhibits also the well-marked alternation, shown in other cases, inwhich the next change, in which an a-particle is not expelled, causess1 F. Exner and E. Haschek, Sitzungsber. K. Akad. Wiss. Wien, 1912, 121,IIa, 1075 ; A. 5. Russell and R. Rossi, Proc. Roy. Soc., 1912, A, 87, 478.52 Soddy, “ Chemistry of the Radio-Elements,” p. 30.REP.-VOL. IX. 322 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the atom to revert t o its original groupfollowing comparison of the uranium and thorium series :Th -'?+ MsTh -5 RaTh -> Th-X -> Eiii -> etc.IV.I I. I v. 0.This is shown by theUr-I -> Ur-K -!+ Ur-ZI -> 10 -'$ Rn -$ Em -> etc.The figures refer to the families in the Periodic Tables to whichthe elements belong. All the members in both series designated bythe same numeral (0, 11, IV, and VI) are chemically identical, sofar as is known.83Obviously, if uranium-ZZ, and not ionium, is the product ofuranium-X, the experiments above referred to with the lattersubstance do not furnish a minimum estimate of the period ofionium, as hitherto supposed, but of that of uranium-ZZ. Thereasoning, however, as regards the absence of growth of radiumfrom uranium remains unmodified, for the two uraniums neces-sarily always exist together in equilibrium proportion.The simplest, if somewhat heterodox, view t o take is that ioniumis a long-period element, and that its spectrum, as well as its wholechemical behaviour, is identical with that of thorium.It is clearthat the conception of chemical elements as necessarily homogeneousis undermined, and that different elements with different atomicweights are chemically identical, not as an exception, but as aconsequence of the way in which the known disintegration serieshave been shown t o run their course. In non-radioactive matterthis heterogeneity cannot be distinguished. Not so in the case ofmatter actually in the process of evolution.VI.IV. VI. I v. XI. 0.Chemical Action of the Rays of Radium.In an investigation of the ozonisation of oxygen by a-rays thenumber of ozone molecules formed was found to be of the sameorder as the number of pairs of ions produced. The ratio betweenthese two quantities varied capriciously, and was in no case greaterthan 1 : 2, frequently being less. The results were consistent withthe view that the ozone results in a reaction between the oxygenions and molecules, but that unknown causes produced a loss of theozone formed, which varied according to the conditions.@The statement that radium emanation exerts a decomposing effect83 Compare A. Fleck, Paper read before Section B, British Association Meeting,Durtdee, 1911 ; Chem.News, 1912, 106, 128. The full results, obtained in theauthor's laboratory, cre in course of publication. Some of them bear on thesubjects discussed in this section.S. C. Lind, Monatsh., 1912, 33, 295; Le Radium, 1912, 9, 104 ; A, ii, 513RADIOACTIVITY, 323on sodium urate, converting it into easily soluble substances, hasbeen submitted to an exhaustive examination, and disproved.85Many of the reactions accelerated or brought about by light 01ultraviolet light have been examined under the influence of thepenetrating rays, of radium. The effects produced by the latterare often very small by comparison. No increase in the rate ofesterification of benzoic acid by alcoholic solution of hydrogenchloride, no effect on p-benzoquinone in alcoholic or etherealsolution, and no action on normal aqueous solutions of oxalic acidat 25O, could be observed, although very powerful radium prepari+tions and long exposures were employed.The formation of theacid from o-nitrobenzaldehyde in alcoholic or benzene solutionswas accelerated by radium rays, although to an extent between10,000 and 20,000 times smaller than is produced by ultravioletlight from a quartz mercury lamp a t 8 cm. distance. As with ultra-violet light, the rays of radium effect a marked increase in therate of inversion of unsterilised neutral sucrose solutions, but theyact oppositely to ultraviolet light in favouring the growth of mouldin sugar solutions.86The liberation of iodine from solution of alkali iodides by thepenetrating rays of radium is notably increased by presence of freeacid, as though the alkali produced had a retarding action, and,like most photochemical actions, is not much influenced by increas-ing the temperature.Potassium iodide is far more sensitive to thisreaction than sodium iodide.87 Similarly, a t least in acid solution,bromine is liberated from solutions of potassium bromide, but theaction is less marked than with the iodide. Acidified potassiumchloride solutions are unaffected.The velocity of decomposition of hydrogen peroxide is greatestin acid and least in alkaline solutions, and no difference wasobserved when paraffined glass vessels were employed. Ferricsulphate, especially in the presence of sucrose, is reduced by pene-trating radium rays as it is by light.88Biocheni ical Effects of Badioactiuity.Three important'communications deal with the differences broughtabout by radioactive agencies in the development of plants, thesprouting of buds of different woods, and the growth of seeds.In95 E. v. Knaffl-Lenz and W. Wiechowski, Zeitsch. physiol. L'hm., 1912, 77, 303 ;A . , ii, 522.bfi A. Kailan, Sitzirngsber. K. Aknd. 1Viss. Wien, 1912, 121, IIa, 1329 ; A . ,1913, ii, 8.87 A. Kailan, Monatsh., 1912, 33, 71; A , , ii, 522.~3 Ibid., 1329 ; A., 1913, ii, 7.Y 324 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.the first,89 watering with radioactive water from Joachimsthal, of300 to 2000 Mach units strength, some seven varieties of plants(Triticum vulgar'c, Hordeum disticum, Vicia faba, Pisium satiuum,Lup*nus angustifolias, Trifolium pratense, and Pisium aruense)produced after a week strikingly favourable effects on the growth.The roots and stalks increased several times in length, and theweight of dried matter in the stalks was from three to five timesgreater than in the case of plants watered with inactive waterof the same chemical composition.On the other hand, variousbacteria (13. mycoides, fluorescens lipuefaciens, pyocyaneum, andfilefaciens) were harmfully affected by the active water, whereasA zohacter chroococcum, the nitrogen assimilating bacterium, wasnot so much affected.I n the second paper,g0 it was found that the winter buds ofvarious woods such as Syringa uulga?-is, when exposed for one ortwo days to the rays of strong radium preparations, or, better,under a bell-jar in an atmosphere containing a few millicuries ofemanation, sprouted when subsequently cultivated in the hot-housein the light, whereas other buds not treated did not sprout at allor only much later.Too little exposure to the rays is withouteffect, and too much exposure is harmful or fatal to the plant. A tother periods of the year no result is produced, and the effect isquite distinct from that produced on the growing plant.Lastly,Ql the influence of the radium &rays of different penetratring power on the development of small seeds, under 0.7 mm.diameter, has been studied. It was found that the growth washindered by irradiation with 6-rays from 8 milligrams of radiuma t a distance of 1 cm., independently of the chemical constitutionof the seed (starch and fat content), which varied widely, and wasgreater for the less penetrating than for the more penetrating rays,when rays of equal ionising power were compared. The retardationof the growth is not noticeable for short exposures (five hours).Aft.er the fifth hour for the first day, the retardation increasesrapidly with the exposure, and then increases less rapidly for longerexposures up to three or four days.It is possible that very shortexposures have a favourable influence on Sinapis nigm and Panicurngermanicum.Various.It is convenient to collect together a number of observations ofEmanations.-The actinium emanation is dissolved by variousHans Molisch, Sitzungsber.K. Akad. Wiss. Wien, 1912, 121, I, 121.special rather than general interest.@ J. Stoklasa, Conqt. rend., 1912, 155, 1096.91 E. D. Congdon, if&., 1911, 120, IIn, 1327RADIOACTIVITY. 325liquids and by charcoal very much as in the case of the otheremanations, but is rather more soluble. The coefficient of solu-bility in water is 2, that of the thorium emanation being 1, andof the radium emanation, 0.33.92 There is no difficulty in detectingthe presence of actinium in a uranium mineral by means of itsemanation, provided small containing vessels and rapid currents ofair are employed.93 The diffusion of the actinium emanation hasbeen further studied, and compared with that of the thoriumemanation.All that can be said is that the molecular weightsof these two emanations must be nearly eq~a1.9~,4ctive Deposits.-Two researches have been made on the dis-tribution of the active deposit of radium under various conditionsbetween the positive and negative electrodes.95 The proportion ofthe active deposit finding its way to the cathode varies much inthe same way as the ratio of the ionisation current in the gas tothe saturation current under the same conditions. To account forthe deposition of the active products on the anode, it is suggestedthat the positive charge on the atoms of radium-A a t formationis neutralised, and in the case of some 2 per cent. reversed bycombination with negative ions in the gas.Negative Results.-No radioactivity is produced in such metalsas bismuth, antimony, and iron by the application of a highfrequency alternating magnetic field,Q6 nor in various chemicalreactions, such as the decomposition of hydroferrocyanic acid byheat, the reduction of potassium dichromate by heating with oxalicacid and of potassium permanganate by heating alone or withreducing agents.97 The radioactivity of rubidium and potassiumsalts is unaffected by exposure to light. No a-rays could be detectedfrom these compounds, and the thermal effect of their radioactivityis too small to be observed.98As regards the existence of radio-uranium, no evidence exceptnegative evidence is forthcoming.99Uranium-P also must be classed with the substances the existenceof which is in need of confirmation.92 G.von Hevesy, Physikal. Zeitsch., 1911, 12, 1214 ; A., ii, 117.9y Idem., ibid., 1213 ; A,, ii, 116.g4 Miss M. S. Leslie, Phi2. Mag., 1912, [vi], 24, 637; A,, ii, 1032 ; J. C.95 E. M. Wellisch and H. L. Bronson, ibid., 23, 714 ; A., ii, 521 ; G. Eckmann,96 J. H. Vincent and A. Bursill, Proc. Physical Soe., 1912, 24, 71 ; A., ii, 417.y7 W. A. D. Rudge, Proc. Camb. Phil. SOC., 1912, 18, 465; A . , ii, 519.98 E. H. Biichner, Proc. R. Akad. Wetemch. Amsterdam, 1912, 15, 2 2 ; A., ii,it9 H. Sirk, Monalsh., 1912, 33, 289; A . , ii, 519.McLennan, ibid., 370 ; A . , ii, 589.Jahrb. Xadioaktiv. Elektronik, 1912, 9, 157 ; A., ii, 620.724326 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.Radioactivity of the Earth and Atmosphere.The fusion method of estimating radium in rocks1 has beenused in a systematic revision, characterised by the feature that,instead of samples of individual rocks, mixed samples composed ofa large number of specimens of different rocks of the same classwere dealt with.Only undifferentiated materials are included.These results establish a substantial difference between the radiumcontent of igneous and sedimentary rocks, which had been ques-tioned by another investigator. I n terms of units of 10-12 gramof radium per gram of rock, the means for igneous rocks, dividedinto three classes, are: (1) acid, 3.01; (2) intermediate, 2'57;(3) basic, 1-28, whilst for sedimentary rocks the mean is 1.4,excluding the calcareous sediments for which the mean is O*8.2The mean of the previous results obtained by the solution method,excluding Joly's results, which are higher, are distinctly lowerthan these new determinations, being, for the three classes ofigneous rocks, 2-17, 1-28, and 0.58 respectively.If 2 is taken as a mean quantity of radium for all the rocks ofthe crust, and 2 x 10-5 gram of thorium per gram of rock isincluded, the heat generated is 25 x 10-14 calorie per gram persecond, and a depth of 17 kilometres would supply all the heatreaching the surface of the earth from the interior.The increaseof temperature at the base of this 17 km. layer would be only2 4 6 O under equilibrium conditions. I f the internal heat is to beentirely attributed to radioactive changes and a state of thermalequilibrium is postulated, it is necessary to suppose that the radio-active layers are less rich than the average surface materials andextend to a greater depth than 17 km.For as Joly has deducedin a general manner, a given quantity of the radio-elements willgenerate a t the base of the layer a higher equilibrium temperaturethe more they are diluted with inactive material, and the greaterthe depth of the layer in consequence.So far as investigations have proceeded, there does not appearto be any systematic variation of the radium content of rocks withthe depth from which they are taken, and rocks from a greatvariety of localities exhibit results closely in accord with the generalmean.3A number of investigatione deal with the emanation content ofAnn.Report, 1911, 293 ; compare E. Ebler, Zeitsch. Elektrochem., 1912, 18,J. Joly, Phil. Mag., 1912, [vi], 24, 694 ; A., ii, 1032; A. L. Fletcher, ibid.,E. H. Buchner, Proc. K. Akad. Welensch. Amsterdzm, 1912, 14, 1063 ; A . , ii,532 ; A . , ii, 723.23, 279 ; A., ii, 224.525RADIOACTIVITY. 327air drawn from the underground soil a t various depths, and theescape of emanation into the atmosphere. It is clear that thequantity of emanation in the atmosphere is continuously main-tained by the amount escaping from the soil. The air drawnfrom even a metre or less below the surface of the ground is severalthousand times richer in radium emanation than the atmosphere,a mean value in one series being 2 x 10-lo curie per litre. Thesupply of emanation is, as is to be expected, not exhausted by thecontinuous withdrawal of the air. Even so, it has been estimatedthat only about 1/70th of the emanation generated by the radiumin the soil escapes into the underground air, and this also is whatis to be expected from the known small proportion of emanationwhich ordinarily escapes from solid substances containing radium.For the purposes of comparison, it may be stated that the 5000litres of gas escaping daily from the Bath springs are estimatedto contain 1.7 x 10-4 curie of emanation. Volume for volume, thisis about 200 times richer in emanation than the underground air,for example, in the neighbourhood of Cambridge and Dublin.The escape of emanation into the atmosphere, and the consequentimpoverishment of the underground air in emanation, is facilitatedby a strong wind and hindered by frost and rain, but the fluc-tuations of the barometer, apart from accompanying stornis andrain, is without direct influence.4In a voyage from Valparaiso to the East Indies, the emanationcontent of the sea water was found to change to an extraordinarycontent with the locality, increasing with the specific gravity andtemperature of the water. The active deposit in the atmospherewas probably not derived from the emanation in the ocean, butfrom emanation carried from the land by winds.5The question of the origin of the earth's penetrating radiation,whether it comes from the earth or the atmosphere, is attractingattention. Most investigators believe that in the free air thepenetrating rays come from the earth, although very near thesurface the effect of a superficial active deposit from the atmospherecan be detected.6 It is noteworthy, however, that in two recentballoon voyages, one a t night and the other during the day, inwhich a specially constructed thick-walled Wulf electrometer wascarried, a t heights f o r the most part about 200 metres from theearth, although the maximum height was about 1000 metres, nodefinite diminution of the effect due to penetrating radiation wasL. B. Smjth, Phil. Mag., 1912, [vi], 24, 638 : A., ii, 1031 ; J. Satterly,Proe. Camb. Phil. Soc., 1911, 16, 336, 356, 514; A., ii, ll?, 118, 522.W. Knoche, Physikal. Zeitsch., 1912, 13, 112, 152 ; A., ii, 223.A. Gockel, Jahrb. Radioaktiv. Elektronik, 1912, 9, 1 ; A, ii, 416 ; W. Strong,Terrestial Magnelism, 1912, 17, 49328 ANNUAL REPORTS ON THE PROGRESS OF CHEMISTRY.observed.7 A t 200 metres from the earth's surface, reckoned as auniform source of y-rays of radium of infinite extent, the absorptionof the air should reduce the intensity of radiation as much as alayer of 1.83 cm. of mercury, and this should, of course, be verynoticeable.8 Probably, however, the instrument was not sufficientlygood to use for the purpose. As is recognised by everyone whohas attempted to reduce the natural leak of an electroscope to itsabsolute minimum, the effect of the radioactivity of the walls isthe chief contributor to the natural leak unless very special means,which it is not wise to leave to the instrument maker, are adopted.This seems to have been the case in the present instance. Theinfluence of the varying amount of ballast carried by the balloonhas also been alluded to.QThe spectrum of Nova Genzinorum (1912), which shows a generalresemblance to that of the solar chromosphere, contains lines whichhave been ascribed t o radium and its emanation. This has ledto the spectrum of the solar chromosphere during the eclipses of1898, 1900, 1901, and 1905 being re-examined, with the resultthat agreement has been found between some of the lines andthose of the radium spectrum. The evidence, however, is con-flicting, and the fact that radium is the source of these linesappears extremely difficult to bclieve.10FREDERICK SODDP.7 V. F. Hess, Sitxicngsbcr K. Akad. Wis8. Wkn, 1911, 120, IIn, 1575.8 An exact expression for the absorption is given by L. V. King, Phil. Mag.,9 L. TT. King, Zoc. cit.lo Astronont. Xachr., 4582, 4589, 4600.1912, [vi], 23, 211

ISSN:0365-6217    

DOI:10.1039/AR9120900289

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

INDEX OF AUTHORS' NAMES.Abderhalden, E., 103,105,230, 231,232.Abell, R. D., 126.Aboulenc, J., 79.Acree, S. F., 35.Adler, A., 17.Adwentowski, K., 64.Agulhon, H., 210.Allen, E. T., 266, 267.Allen, H. C., 120.Allen, I. C., 217.Allen, W. S., 201, 202, 204.Alpern, R., 103.Amadori, M., 258.Amberger, C., 54.Ambler, J. A., 175.Andersen, A. C., 104.Andersen, O., 276.Andrews, V. L., 236.Angeli, A., 135.Anrep, G. von, 222.Anschutz, R., 112.Archibald, E. H., 20.Armani, G., 215.Armstrong, H. E., 263.Arrhenius, S., 26, 27.Asahina, Y., 94, 168, 169.Asch, D., 259.Asch, W., 259.Aschan, O., 83, 148, 149.Auerbach, F., 34.Auld, S. J. M., 219.Auwers, K., 122, 126, 143, 144, 150.Bachmann, W'., 30.Bacon, R. F., 213.Baeyer, 0. VOIJ, 297, 299.Baker, F., 99.Bakunin, M.189.Ba116, R., 283.Baly, E. C. C., 142.Bamberger, E., 107, 128, 135.1Bancroft, W. D., 34.Barbier, P., 213, 276, 281.Baibieri, G. A., 60.Barger, G., 27.Barker, T. V., 266.Barkla, C. G., 302, 304.Barratt, J. 0. W., 33.Barratt, T., 312.Barre, M., 61.Bartell, F. E., 15.Bartholomiius, E., 168.Bartoni, J;, 215.Bary, P., 17, 78.Baschieri, E., 279.Batey, J. P., 194.Baubigny, H., 60.Baudisch, O., 135, 197.Baumann, P., 209.Baume, G., 37.Baumhauer, H., 269.Baxter, G. P., 37, 39.Bayer, A., 203.Bayne- Jones, S., 238.Beadle, C., 78.Beckmann, E., 195.Belasio, R., 209.Bellet, E., 146.Bengis, R., 175.Bennett, C. W., 52.Berkeley, Earl of, 15.Berthelot, D., 97.Bertrand, G., 251.Berwerth, F., 286, 288.Besborodko, N., 281.Besson.A., 64.Beutell, A., 279.Bevan, E. J., 212.Bhaduri, K., 75.Rianu, B. 317.Biddle, H.' C., 152, 155.Bielecki, J., 97.330 lNDEX OF AUTHORS’ NAMES.Biilmann, E., 178 et seq.Billows, E., 57, 269.Biltz, W., 24, 278.Bingham, E. C., 12, 195.Bishop, H. B., 202.Bjerrum, N., 10.Black, S., 191.Blanc, G. L., 151.Blanck, E., 245, 252.Bland, N., 85, 88, 158.Bleicher, K., 264.Bleyer, B., 204.Blum, W., 206.Boeke, H. E., 260.Boaseken, J., 114, 116, 213.Boesler, W., 160.Bottcher, B., 155.Boll, M., 51.Boshart, K., 204.Bosshard, E., 63.Bossuet, R., 0.Bostock, C., 70.Boulez, V., 216.Boullanger, E., 244.Bourion, F., 57, 205.Bousfield, W. E., 5.Bousfield, W.R., 5.Bowden, R. C., 32.Bowen, N. L., 256, 279.Boyd, R., 146.Boylston, A. C., 37.Bradley, C. E., 216.Bradley, W. M., 280, 285.Bragg, W. H., 302.Bragg, W. L., 302.Brand, H., 258.Brann, B. F., 37.Braun, J. von, 114.Braune, H., 25.Brauns, R., 277.Brautlecht, C. A., 175.Bray, W. C., W, 198.BrBaudat, L., 253.Bredig, G., 25, 177.Bredt, J., 150, 151.Bridgman, P. W., 1.Brockmoller, I., 39.Bronson, H. L., 325.Brown, A. J., 252.Brown, D. J., 209.Brown, P. E., 245, 247, 248.Brun, A., !283.Brunner, A., 283.Bruno, A., 210.Buchner, E. H., 325, 326.Buttner, E., 173.Buglia, G., 232.Bumstead, H. A., 302,Burdick, W. L., 209.Burgess, L. L., 199.Burgeas, M. J., 75.Bursill, A., 325.Burt, F. P., 37.Butavand, I?., 295.Butureairu, V.C., 271Cain, J. C., 120.Cain, J. R., 205, 208.Calcagni, G., 258.Callendar, H. L., 5.Cameron, A. T., 104.Campbell, N., 301.Carlson, A. J., 222.Carney, R. J., 199.Carr, F. H., 155.Carrel, A., 224.Casares, R., 114.Cash, G., 13.Cecil, H. L., 239.Cesaris, P. de, 258.&ho, G., 272.Chadwick, J., 294, 300, 306, 307.Chamot, E. M., 220.Chapman, D. L., 53.Chattaway, F. D., 102, 130.Chauvenet, E., 42.Chernoff, L. H., 175.Chouchak, z?., 250.Christopher, H., 162, 185.Clarke, H. T., 164.Clausmann, P., 200.Colacicchi, U., 168.Colwell, H. A., 97.Congdon, E. D., 324.Conno, E. de’, 130.Cooper, E. A., 235.Cooper, H. C., 257.Cornish, Miss E. C. V., 32.Corvazier, H., 210.Cost&chewu, N., 173.Coulthard, A., 120.Couyat, J., 287.Cramer, C., J36.Cramer, W., 238.Crawford, W.G., 209.Cremer, M., 96.Crenshaw, J. L., 266, 267.Crompton, H., 153.Crook, T., 276, 283.Crookes, Sir W., 207.Cross, C. F., 212.Cross, W. E., 214.Crowther, C., 251.Crymble, C. R., 143, 162, 163.Cumming, A. C., 59.Cunningham, Miss M., 98.Curtius, T., 250.D’Achiardi, G., 272, 280.Dafert, F. W., 55, 68.Dale, H. H., 222.D’Ans, J., 60, 91.cl’OSSl8y, A. W., 145INDEX OF AUTHORS’ NAMES. 331Danysz, J., 297, 299.Darwin, C. G., 296, 313, 314.Darzens, G., 105.Daube, A., 156.D’Auzay, P. T., 210.Davis, C., 202.Davis, D., 239.Davis, W. A., 217, 218.Dawson, H. M., 83, 126.De, T., 39.Debierne, A., 306.Dehn, W. M., 100.Delgrosso, M., 276.Demolon, A., 244.Demorest, D.J., 206, 208.Denis, W., 211, 231.Dewey, F. P., 207.Ilhar, N., 39.l)h6&, C., 167.Dieckmann, W., 126.Dienert, F., 210.IXttler, E., 275, 283.Divers, E., 45.IXxon, A. E., 102.Iloelter, C., 275.Uonau, J., 196.I)o&e, C., 98.Ilormann, E., 170, 172.Iloss, B., 270.Ureaper, W. P., 119.IhozdowBki, E., 64.I)rushel, W. A., 192.h c l a u x , J., 5.Dudley, W. L., 38.Durrfeld, V., 286.Dugardin, M., 244.Dumanski, A., 53.Dunbar, P. B., 213.Dunstan, W. R., 17.Duparc, L., 275.Dupont, J., 216.Duschetschkin, A., 249.Duval, H., 175.Easley, C. W., 37.Eberle, F., 128.Ebler, E., 326.Eckmann, G., 325.Edie, E. S., 235.Einecke, A., 245.Ekecrantz, T., 81.Elissafoff, G.von, 33.Ellinger, P., 143.Ellis, R., 31.Elsdon, G. D., 220.Embden, G., 230.Endell, K., 283.Ephraim, F., 40, 41.Ermen, W. F. A., 58.Eve, A. S., 307.Evers, N., 220.Ewins, A. J., 153, 154.Exner, F., 321.Eynon, L., 211.Fairlie, D. M., 73.Fajans, K., 315, 316.Falk, K. G., 21.Faltis, F., 191.Farnau, E. F., 120.Farrow, F. D., 32.Fastert, C., 282.Faust, O., 11.Fedoroff, E. S., 261.Feinberg, B. G., 211.Feist, K., 152.Fenton, H. J. H., 85.Fermor, L. L., 286.Fernbach, A., 76, 97.Ferry, Miss E. L., 229.Fichter, F., 101.Ficken, K., 173.Fiehe, J., 215.Field, Miss E., 27.Fine, M. S., 229.Fingerling, G., 254.Fischer, E., 94, 96, 116, 152, 178, 179Fischer, Hans, 168.Fischer, Hugo, 245.Fischer, M. H., 240, 241.Fischer, O., 160.Fischer, W.M., 201.Fiske, P. S., 177.Fleck, A., 322.Fleischer, K., 156.Fletcher, A. L., 326.Flint, W. R., 38.Flohil, J. T., 211.Forster, F., 16.Fokin, S., 84.Folh, O., 211, 231.Foote, H. W., 208, 280, 285.Foote, W. M., 288.Forster, M. O., 150, 151.Foucar, J. L., 202.Fowler, A., 49.Frankforter, G. B., 213.Frankland, P. F., 183, 184, 187.Franklin, E. C., 66, 67.Franzen, H., 80, 250.Frary, F. C., 213.Freudenberg, K., 152.Freund, M., 156, 157, 158, 159.Freundlich, H., 28.Frey, W., 91.Friederich, W., 60.Friedrich, K., 259.Friedrich, W., 302.Funk, C., 104, 234, 236.Gadamer, J., 180.Garnier, C., 57.Gamer, M. M., €1332 INDEX OF AUTHORS’ NAMES.Gastaldi, C., 84, 214.Gaudechon, H., 97.Gautier, A,, 200.Geiger, H., 292, 293, 295, 296.Gemmell, A., 59.Gerber, C., 98.Getman, F.H., 35.Gibbons, V. L., 35.Gibson, G. E., 40.Gies, W. J., 241.Gillet, C., 91.Glendinning, W. G., 143.Glover, W. H., 150.Gockel, A., 327.Gotz, J., 297.Goldenberg, H., 56.Goldmann, E., Z 5 .Goldschmidt, F., 33.Goldschrnidt, H., 25.Gomber M., 132, 140.Gonnart F., 273, 276, 281.Gooch, F. A., 209.Gorsky, A., 145.Goutal, E., 206.Grabowski, J., 169.Grafe, E., 230.Grandmougin, E., 213.Grave, E., 16.Gray, J. A., 300.Greaves, J. E., 248.Green, A. G., 136.Grignard, V., 146.Gristchinsky, 288.Gr6h, J., 177.Grube, G., 17.Grunmach, U., 11.Guerbet, M., 79.Guest, H. H., 175.Guggenheim, M., 103.Gutmann, A., 136.Guye, P.A., 36.Haas, A., 276, 280.Haber, F., 19.Hackspill, L., 60.Hahn, O., 297, 314.Hall, A. D., 245.Haller, A., 150.Halnan, E. T., 253.Halphen, G., 215.Hantzsch, A., 71, 118, 119, 122, 123,Harden, A., 98.Hardman, R. T., 21, 35.Hardy, W. B., 28, 30.Harkins, W. D., 23.Harned, H. S., 210.Harries, C. D., 76, 77, 78, 106, 107,Harris, A. B., 33.Haschek, E., 321.Hasenfratz, V., 160.125, 134, 135, 138, 143.145, 148.Hatschek, E., 30, 54.Hauser, F., 301.Hauser, O., 74, 208, 209.Havas, E., 213.Haworth, W. N., 149.Headden, W. P., 249.Heath, G. L., 204.Heffner, B., 278.Heike, W., 258.Heilbron, I. M., 149.Hem el, W., 197.Henferson, G. G., 146, 149.Henderson, J. B., 214.Herzfeld, H., 74.Herzfeld, K. F., 296.Herzig, J., 153.Hesehus, N.A., 43.Hess, L., 169.Hess, V. F., 307, 309, 310, 311, 320,Hevesy, G. von, 314, 319, 325.Hewitt, J. T., 120, 136.Heymann, P., 189.Hezner, L., 269.Hibbert, H., 100, 210.Hibsch, J. E., 286.Higens, S. H., 70.Hiki, T., 288.Hilbing, W., 151.Hildebrand, J. H., 210.Hilditch, T. P., 161, 163, 184, 185.Hill, A. J., 175.Hill, J. R., 17.Hine, T. B., 67.Hinrichsen, F. W., 146.Hintikka, S. V., 150.Hirsch, A., 55.Hirsch, P., 230.Hissink, D. J., 245.Hlawatsch, C., 265.Hoben, F. M., 58.Hodge, W. W., 175.Honigschmid, O., 38, 289Hoyrup, M., 104.Hoffman, C., 175.Hoffmann, J., 54.Hofmann, F., 78.Holland, W. W., 13.Hollely, W. F., 126.Holleman, A. F., 116, 117.Hollnagel, H., 9.Holmberg, B., 182.Holmberg, O., 38.Homfray, Miss I.F., 26.Hoover, C. R., 39.Hope, E., 93, 157.Hopfgartner, K., 20.Hopkins, F. G., 234.Horovitz, S., 155.Horwmd, C. B., 278.Hostetter, J. C., 208.Houben, H., 258.328INDEX OF AUTHORS’ NAMES. 333Howell, W. H., 239.Huhn, F., 212.Huttner, C., 207.Hutchinson, A., 277, 279, 280.Hynd, A., 95.Irvine, J. C., 95.Isgarischeff, N., 35.Isham, H., 206.Isler, M., 165.Istrati, C. I., 268.Itarni, S., 222.Ivanoff, L. L., 288.Jackson, C. L., 129.Jacobs, W. A., 217, 223.Jaeger, F. M., 257, 280.Janecke, E., 256.Jarvinen, K. K., 203.Jakbb, W., 284.James, C., 58.James, D. I., 177, 180.Jantsch, G., 57.Jsvillier, M., 251.Jerusalem, G., 177, 264.Jetek, B., 268, 272.Job, P., 51.Johnson, F.M. G., 63.Johnson, T. B., 175.Johnston, J., 266.Johnston, R. A. A., 274.Johnstone, S. J., 283.Joly, J., 326.Jones, E. G., 157.Jones, E. V., 38.Jones, H. O . , 177, 180.Joye, P., 57.Jiirgens, B., 118.Kailan, A., 323.Kalusky, L., 215.Kamm, O., 199.Karaoglanoff, L., 206.Kauffmann, H., 120, 137, 141.Kautzsch, K., 105.Kay, S. A., 219.Kayes, F. G., 34.Kehrmann, F., 121, 129, 132.Kelber, L. C., 146.Kellerhoff, E., 91.Kellermann, K. F., 246.Kelley, G. L., 129.Kelley, W. P., 152.Kempf, R., 146.Kendall, J., 21, 23, 260.Kenner, J., 146.Kenyon, J., 183, 184.Kerb, J., 105.Kieser, F., 139.Kijner, N. M., 175.King, A. T., 149.King, L. V., 307, 328.Kipping, F. S., 111, 112.Kirschner, A., 189.liii3p:p;ltiE, M., 274.Klason, P., 202.Klein, A.A., 257.Klinger, G., 197.Klooster, H. S. van, 257, 280.Knaffl-Leuz, E. von, 323.Knecht, E., 194.Knipping, P., 302.Knoche, W., 327.Knorr, L., 169.Kobayashi, M., 284.Kober, P. A., 132, 173.Konig, J., 212.Kotz, A, 146.Kohnstamm, P., 10.Kolb, A,, 199.Komppa, G., 150, 151.Kondakoff, I. L., 78.Kopetschni, E., 141.Koref, F., 9.KOSS, M., 208.Kossel, A., 104.Kotukoff, I. I., 99.Koukline, E. V., 206.Kovarik, A. F., 317.Kramm, I?., 232.Kraus, E. H., 257.Kroll, A. V. M., 259.Krulla, R., 142.Kupfer, O., 106, 157.Kusnetzoff, S. D., 284.Laar, J. J. van, 4.Labaune, L., 216.Lacroix, A., 269, 270, 272, 274, 275,Laidlaw, P. P., 222.Lambert, B., 47.Lamp5, A. E., 230, 231.Lane, J.H., 211.Langhans, A., 93.Langley, R. W., 208.Langmuir, I., 12, 50.Lankshear, F. R., 151.Lapworth, A., 21, 35.Larsen, E. S., 266.Lashgue, G., 199.Lathrop, E. C., 244.Lau,e, M., 302.Lebeau, P., 39.Lebedeff, P., 18, 257.Lebedeff, S. V., 147.Lemmermann, O., 245.Eenher, V., 209.Lepape, A., 309.Lepkowski, W. G. von, 30.Leslie, Miss M. S., 83, 325.Levene, P. A., 223, 233.276, 278, 281, 282, 283, 285334 INDEX OF ALTHORS’ NAMES.Levj, A. G., 206.Lewcock, W., 83.Lewis, E. A., 203.Lewis, G. N., 34, 35.Lewis, W. C. M., 35, 52.Lewite, A, 208, 209.Ley, H., 173.Leyko, L., 169.Liebig, H. von, 114, 132.Lifschitz, I., 134.Lind, S. C., 322.Lindemann, F. A., 7, 8.Linden, T. van der, 115.Lipman, C. B., 249.Lip , P., 150.LittTe, H.F. V., 206.G b , W., 97.London, E. 8., 231.h m i s , N. E., 35.Loschmidt, J., 112.Lovisato, D., 273.Lowry, T. M., 49, 150.Luc, A. de, 126.McAdam, D. J., jun., 37.Macara, T., 215.McBain, J. W., 23, 32, 131.Macbeth, A. K., 134, 142, 165,McBeth, L. G., 246.McCay, L. W., 207.McCollum, E. V., 229, 254.McCoy, H. N., 108.McDonald, D. P., 274.McGougan, A. G., 302.Mache, H., 311.MacInnes, D. A., 24.Maclean, H., 235.McLennan, J. C., 325.Maddalena, L., 275.Mahler, P., 206.Mailhe, A., 80.Maillard, L. C., 103, 104.Makower, W., 316.Malarski, H., 167.Malfitano, G., 97.Manasse, E., 277.Manchot, W., 46, 74, 116, 278.Many&, R 26* J., 152.MarcMarchlewski, L., 167, 169.Marckwald, W., 291.Marcus, E., 278.Marmier, L., 51 .Marsden, E., 313, 314.Marshall, J.T., 132.Martin, W., 68.Martyn, G. H., 302.Maselli, C., 154.Masius, M., 28.Massenez, C., 62.Massol, L., 97.Masson, J. I. O., 308.189.Matuschek, J., 52.Mau, W., 65.Mauritz, B., 273.Meek, W. J., 238.Meister, A, 270.Meitner, L., 297, 314.Meldola, R., 126.Mendel, L. B., 229.Menschutkin, 13. N., 116.Merwin, H. E., 267.Meunier, S., 287, 288.Meyer, A. R., 69.Meyer, F., 36, 44.Meyer, G. M., 233.Meyer, H., 80.Meyer, K. H., 83, 92, 108, 122, 124,125, 126, 140.Meyer, R. 74, 132.Meyer, R. J., 56.Meyer, S., 292, 309, 311, 320.Rlicewicz, S., 121.Michael, ,4. 92, 124, 185.Michl, W., 296.Micklethwait, Miss F. M. G., 120.Mihailescu, M., 268.Miklauz, R., 55, 68.Millar, W.S., 25.Minovici, S., 110.Mohr, E., 126.Mohr, O., 198.Molisch, H., 324.Montgomerie, H. H., 189.Moore, A. R., 241.Moore, B., 235.Moore, C. J., 37.Moore, C. W., 153.Moore, W. C., 108.Moormann, A., 204.Moosbrugger, W., 143 .Moran, R. C., 175.Morgan, G. T., 118, 134.Morgan, W. C., 38.Morrell, R. S., 110.Morse, H. N., 13.Moschkoff, Mlle. A., 97.Moseley, H. G. J., 297.Moser, L., 46, 203.Moureu, C., 309.Muller, E., 91.Muller, H., 98.Muller, N. I;.. 191.Mulert, O., 260.Myers, C. N., 13.Mylius, F., 207.Mylo, B., 81, 82.Nacken, R., 274.Nasini, R., 279.Nastukoff, A. M., 99.Neave, G. B., 146.Nenning, 52.Nernst, W., 6, 7, 8, 10, 19INDEX OF AUTHORS’ NAMES.Neuberg, C., 105, 210.Neville, H.A. D., 253.Newman, L. F., 253.Nicolet, B. H., 175.Niederstadt, K., 61, 261.Nierenstein, M., 152.Nikolaevski, T. A., 273.Nolan, T. J., 163.Norman, G. M., 136.Nottbohm, F. E., 205.Novsk, J., 105.Nowak, H., 214.Noyes, A. A., 21, 23, 198.Noyes, W. A., 151.Nuttall, J. M., 292, 293.O’Brien, W. B., 175.Odake, S., 253.Oddo, B., 131.Ostling, G. J., 150.Oltrogge, H. C., 74.Onnes, H. K., 18.Orloff, N., 276.Orndorff, W. R., 130.Ornstein, L. S., 10.Osborne, T. B., 229.Oschan, O., 126.Ostromisslensky, I., 76, 106, 145.Ott, E., 89, 129.P a l , C., 146.Pa e, H. J., 111.Paitzsch, S., 219.Palmh, J., 148.Palmer, R. M., 204.Paneth, F., 292.Panichi, U., 276.PappadA, N., 54.Parravano, N., 258, 277, 281.Paternb, E., 154.Patrick, W.A., 205.Patten, A. J., 218.Patterson, T. S., 189.Pa , A. de, 120.Pehni, G., 38.Perkin, W. H., jun., 75, 146, 151, 157Perrot, F. L., 37.Petherbridge, F. R., 243.Pfau, G. M., 175.Pfeiffer, P., 116, 139.Pfeiffer, T., 252.Piccard. J.. 119. 139.et seq.Pickard; R‘. H.; 183, 184.Pictet, A., 75.Piloty, O., 169, 170, 171, 172.Pincussohn. L.. 241.Pirani, M.’vo& 69.Piutti, A., 130.Planck, M., 6, 10.Pollard, J. B., 288.Pollitzer, F., 8.Polahrff, K., 80.Ponzio, G., 84.Poole, H. H., 311.Pope, F. G., 120.Pope, W. J., 175, 176, 177.Porchet, F., 216.Porter, A. W., 12.Porter, Miss M. W., 263.Posner, F., 132.Pouget, I., 250.Pound, V. E., 300.Power, F. B., 110.Powis, F., 83, 126.Prztorius, P., 66.Pratt, D.S., 130, 220.Preuner, G., 39.Prjng, J. N., 73.Pringle, H., 238.Pringsheim, H., 98.Prior, G. T.> 288.Przibram, K., 296.Purgotti, A., 199.Pyman, F: L., 175.Quercigh, E., 258, 284.Rabe, P., 155, 156, 157.Rakowski, A. W., 28.Ramann, E., 250.Ramsay, Sir W., 38, 39, 290, 308.Ramseyer, L., 75.Rankin, G. A., 256.Raschi F., 45.Ratcliff;, W. H., 136.RAY, P. R., 200.Ray, R. C., 61.Rea, Miss F. W., 143.Read, J., 175, 176, 177.Recoura, A., 71.Redfield, H. W., 220.Renner, O., 269.Renschler, E., 69.Reuss, F., 144, 147.Reverdin. F.. 126.RAY, P. c., 39.Reynolds; W.‘ C., 45, 51, 155.Rhead, T. F. E., 43.Richards. T. W.. 194.Richmond, H. D:, 214.Richter, M. M., 142.Riedel, O., 282.Riegel, E.R., 69.Rieke, R., 283.Riesenfeld, W., 65.Ritter, G., 126.Ritter, H., 146.Robel, J., 167.Robertson, I. W., 217.Robinson, C. H., 58.Robinson, C. S., 218.Robinson, G. W., 245, 253.Robinson, H., 310.33336 INDEX OF AUTHORS’ NAMES.Robinson, R., 157, 158, 159, 160.Robison, R., 112.Rodd, E. H., 263.Rogers, A. F., 272, 273, 274, 278.Rogerson, H., 110.Rogowski, W. de, 167.Rohmann, F., B9.Romijn, G., 205.Rosati, A., 277.Rosenheim, d., 207.Roshdestwensky, A., 35.Rosickg, V., 272.Ross, K., 162, 163.Rossi, R., 321.Roth, W. A,, 24.Rubens, H., 9.Ruder, W. E., 69.Rudge, W. 8. D., 325.Rugheimer, L., 126.Ruff, O., 68.Rupert, F. F., 35.Rupp, E., 131.Rum, S., 97.Russell, A. S., 294, 300, 317, 318, 321.Russell, E.J., 243, 245.Ruston, A. G., 251.Rutherford, E., 295, 297, 298, 306, 310.Rzehak, A., 287.Sabatier, P., 80.Sabot, R., 275.Sachanoff, A. N., 20.Sackett, W. G., 249.Sanchez, Z. A., 210.Sandonnini, C., 258.Saneyoshi, S., 210.Sanger, C. R., 69.Satterly, J., 327.Schaeffer, E., 146.Schaller, W. T., 270, 271, 281, 284, 285.Schardinger, F., 98.Scheiber, J., 129.Scheit, A., 286.Schlapfer, V., 230.Schlenk, W., 139.Schmidlin, J., 140.Schmidt, G. C., 26.Schneckenberg, E., 52.Schoch, E. P., 209.Schoen, M., 97.Scholl, R., 128.Scholtz, M., 174.Schrader, H., 42, 318.Schreiner, O., 244.Schulemann, W., 228.Schwarz, A., 146.Schwarz, R., 285.Schweidler, E. von, 307.Sebor, J., 97.Semper, L., 141.Sen, H.K., 200.Senderens, J. B., 79, 80.Senter, G., 182.Seuffert, R. W., 96.Sharp, L. T., 249.Shepard, N. A., 175.Shibata, K., 157.Shimamura, T., 253.Shimer, E. B., 209.Shimer, P. W., 209:Shinn, 0. L., 38.Shipley, J. W., 194.Siegmund, W., 213.Simmonds, C., 212.Simons, L., 304.Sirk, H., 325.Skita, A., 146.Slyke, D. D. van, 232.Smiles, S., 161, 162, 163.Smith, C., 83.Smith, E. F., 37.Smith, G. F. H., 270.Smith, R. S., 247.Smith, T. O., 58.Smith, W. C., 277, 279, 280.Smyth, L. B., 327.Snethlage, H. C. H., 25.Snowden, R. C., 120.Soddy, F., 320, 321.Sorensen, S. P. L., 104.Solly, R. H., 270.Souza- HranGo, V., 269.Spacu, G., 173.Spence, D., 77.Spencer, J. F., 35.Spinner, H., 151.Stahler, A., 36.Stafford, 0.J., 12.Stamm, E,., 40, 42.Stark, O., 147, 148.Staudinger, H., 106.Stegmuller, P., 215.Steinbach, N., 201.Steinkopf, W., 118, 174.Steinmann, A., 207.Stevens, H. P., 78.Stewart, A. W., 134, 143, 165, 189.Stewart, R., 248.Stobbe, H., 144, 147.Stock, A. 40, 42, 62, 66.Stock, J.,’ 169.Stoecklin, L., 215.Stoermer, R., 189.Stoklasa, J., 97 249, 324.Stoll, A., 166, 167.Stoll6, R., 175.Stoltzenberg, H., 103.Strauss, H., 96.Strumberg, H., 238.Strong, W., 327,Strutt, Hon. R. J., 48, 49.Sudborough, J. J., 190, 191.Sugiura, K., 173INDEX OFSuzuki, U., 107, 253.Swinne, R., 10, 295.Tafel, J., 92.Taggart, W. G., 214.Tammann, G., 286.Tanatar, S. M., 188.Tartar, H. V., 216.Taylor, J., 102.Taylor, Miss M., 32.Taylor, R.L., 70.Taylor, T. S., 304.Taylor, W. H., 45, 51.Terni, a4., 63.Thannhauser, S. J., 170, 171, 172.Thiele, J., 135.Thirring, H., 307 .Thoni, J., 215.Thole, F. B., 85, 187.Thomas, E. R., 190.Thomas, P., 210.Thomson, Sir J. J., 305.Thorpe, J. F., 85, 88, 100, 151.Thuesen, 9., 25.Thugutt, S. J., 273, 286.Titoff, *%., 26, 27.Tonduz, P., 216.T6th, J., 216.Tot~oczko, S., 284.Trapp, H., 199.Travers, M. W., 61.Treadwell, W. D., 203.Tritsch, W., 128.Trouton, F. T., 14.Truthe, W., 258.Tschermak, G., 259.Tschirwinskp, W., 274.Tschugaeff, I;. A., 107.Turner, Miss E. G., 146.Tntton, -4. E. H., 263, 302.Tyrer, D., 11.TTdby, O., 25.'I_Thl.ig, J., !273.Vlrich, C., 215.Grbain, G., 57.1-tzinger, >I., 166, 167.Vassallo, E., 131.Vaubel, W., 261.Vernadskv, W., 278.Villiger, V., 141.Vincent.J. H.. 325.Vlahutza, E., 110.Voltz, W., 230.Vonel. J., 248.T7nY$,; I<:, 118.Voljansky, I.. 188.Voroschtsoff, S. N., 136.Wagenaar, M., 199.Wnkimizu, T., 288.IIEP.--VQL. I.Y.AUTHORS' NAMES. 337Walden, P., 10.Walker, J., 219.Walker, W. H., 205.Wallach, O., 146, 151.Walther, P., 272.Warren, C. H., 282.Wartenberg, H. von, 12.Waser, E., 113, 145.Washburn, E. W. 24.Washington, H. d., 260.Waterman, 11. J., 213.Watson, T. L., 281.m'eber, H. C. P., 37.Weber, W., 195.Wegelin, G., 91.Wegscheider, R., 191.Weinland, R. F., 173.Weissel, L., 141.Weissmann, L., 33.Weisspf enning, G., 128.Weisswange, W., 205.Weizmann, C., 103.Wellisch, E. M., 325.Welsbach, C. A. von, 55, 56.Wenger, T., 204.Wenk, W., 101.Werner, A., 178.Werner, E. A., 101.Wertenstein, U., 316, 317.West, F. L., 108.Weydert, L., 77.Wheeler, A. S., 102.Wheeler, R. V., 43, 75.Wherry, E. T., 276.White, G. F., 12, 195, 196.Whittemore, C. F., 58.Whptlaw-Gray, R., 37, 38, 290.Wichdorff. H. H. von. 280.Wiechowski, W., 323.Wieland, H., 44, 46, 117, 121, 140, 146,235. ~- -Wilke-Dorf urt, E., 206.Wilks, W. A. R., 85.Willard, H. H., 71.Willett, Miss W. I., 120.Williams, H. E., 200Willstatter, R,, 113, 129, 136, 144, 145,146, 165, e t seq.Wilson, C. T. R., 303.Wilson, H. A . , 295.Wilson, W., 299.Windaus, A., 109, 110.Winltler, H., 173.Winther, C., 51.Wirth, F., 207.Wise, A., 100.Wislicenus, W., 92, 124, 125.Withers, J. C., 74.Witt, F. H., 136.ll'ohl, -4., 81, 82.Wolff, J. E., 271.W~lff, T A . , 147.338 INDEX OF AUTHORS’ NAMES.Wolff, S., 136.Wollmann, Mme. E., 5.Woodhead, A. E., 136.Worley, F. P., 252.Wourtzel, E., 36, 37.Wright, F. E., 256.Wright, R., 134, 143, 165.Wiinsch, D. F. S., 130.Wunder, M., 204, 275.Wurmser, R., 97.Wuyts, H., 80.Young, W. J., 96.I Zach, K., 94.~ Zak, E., 239.Zambonini, F., 269, 271, 280.Zawadzki, J., 19.Zdobnickjr, W., 97.Zelinsky, N. D., 145.Zerewitinoff, T., 131, 211Zincke, T., 128.Zinke, G., 257.Zinn, J. B., 13.Zurkowski, B., 167Zwicky, K., 63

ISSN:0365-6217    

DOI:10.1039/AR9120900329

出版商:RSC    

年代:1912

数据来源: RSC

摘要:

INDEX OF SUBJECTS.Acapnia, 241.Acetic anhydride, interaction of a-pico-Acetylene, pyrogenic condensation of,compound of cuprous chloride and,line and, 174.74.74.Acid chlorides, 82.Acids, organic, 82.Adsorption, investigations on, 27.Adsorption formulz, 26.Agricultural analysis, 217.Albanite, 268.A41cohols, 79.Aldehydes, 79.Alkaloids, 154.Allcharite, 268.Allophane, 273.Allotropy, 42.Aluminium compounds, 63.Alunogen, 273.Aniides, 101.Amine compounds, 66.Amines, 100.Amino-acids, 103.Ammonium nitrite, molecular weightAmpangabdite, 268.Amphibole group, 273.A4mylose, 98.Analcite, 285.Analysis, inorganic, 198.Anhydroniethylglucoside, 94.Aniline-black, 136.Animal body, repair, growth andsynthesis in the, 228.Apatite group, 273.Aragonite, distinction of calcite from,61.Arduinite, 269.r-Arginine, synthesis of, 104.of, 39.-4romatic compounds, substitution in,Arsenic, molecular weight of, 39.trisulphide, colloidal, 53.estimation of, 204.Arsenof errite, 269.Asymmetry, molecular, 175.Atmosphere, radioactivity of the, 326.Atomic heats, 9.Atomic weights, 36.Auxochrome theory, 137.Awaruite, 274.Axinite, 274.Azo-colouring matters, estimation of,213.Azo-compounds, absorption spectra of,134.cnclo-Azo-com ounds, 175.Azodicarboxyrimide derivatives, 175.116.Bacteriology, 246.Baddeleyite, 274.Baeumlerite, 269.Bastnaesite, 274.Bauxite, 274.Benzaldehyde, estimation of, 211.Benzeins, 131, 132.Benzene nucleus, structure of the, 112.Benzidine, o-dinitro-derivatives, 120.Benzocycloheptadienes, synthesis of,o-Benmquinones, 129.Berberine and its derivatives, 158.Beri-beri, 234.Beryl, 275.Betafite, 269.Rilic acid, 171.Bismuth, occurrence of, 276.Bleaching, process of, 70.Bleaching-powder, reactions of, 70.146.33340 INDEX OF SUBJECTS.Blood, coagulation of the, 236.colouring matter of the, 170.Boron compounds, 61, 62, 63.Bromine, atomic weight of, 37.Butadiene-caoutchouc, 76.a-Butadienylpyrrole, 174.cycloButanes, preparation of, 147.Caesium nitrate and law of massCalcite, distinction of aragonite from,Calcium carbonate, double salts of, 61.Camphene, 148.Camphor, 150.isocamphor, 151.Camphorylphenylthiosemicarbazide,gelatinisation of, 30.Caouprene bromide, 76.Caoutchouc, synthetic, 75.a.ction of ozone on, 77.molecular weight of, 78.vulcanisation of, 77.action, 24.61.Carbamide, formation of, 102.Carbohydra,tes, 94.Carbon, allotrophy of, 43.dioxide, reduction of, 43, 44.oxidation of, 43.pernitride, 105.Percarbonates, constitution of, 65.Carbon subsulphide, 66.Carnotite, 276.Catalytic action of hydrogen ions, 24.Celestite, 276.Cellulose, ozonisation of, 98.estimation of, 211.nitro-, solution of, 99.Cerium, metallic, 55.hydride and nitride, 55.Charcoal, animal, adsorption by, 28.Chinese wood oil, 110.Chlorine, atomic weight of, 36, 37.Perchloric acid dihydrate, 71.Chlorophyll, 165.Chlorosulphonic acid, 69.Cholesterol, action of ozone on, 107.Chrombrugnatellite, 269.Chromium, estimation of, 205.Cinchona alkaloids, 155.Citronella oil, analysis of, 216.Zlrutonite group, 276.Clupeine, constitution of, 104.Cobalt hydroxides, 71.Cocoa, estimation of shell in, 215.Colloidal solutions, theory of, 30.Colloidal state, relation betweencrystalline state and, 28.Colloids, 53.Combustion, 43.degradation products of, 109.Conductivity, molecular, anomalouscurves of, 20.thermal, of gases, 12.Copper, salts of, 58, 59.estimation of, 203.Cryptose, 269.Crystalline state, relation betweencolloidal state and, 28.Crystallography, chemical, 261.Damascenine, 153, 154.Desmotropic compounds, brominationof, 125.Dasoxyn, 99.Dextrin, isomeric forms of, 98.Diamond, atomic heat of, 9.Diazoacetic acid, ethyl ester, rate ofdecomposition of, 25..Diazo-col.l;lpounds, 133, 135.Diazomethane, preparation of pure,1%.Didymolite, 270.Dihydroh dtastinine, isomeric formsof, 16.1 : 3-Dlketones, 124.5-Dimethylsminoanilo - 3 : 4 - diphenyl-cyclopentane - 1 : 2 - dione, gelatin-isation of, 28.a- and 8-2 : 5-Dimethylpipera~ines~ 176.Diphenylamine, 121.Disintegration, multiple, 311.Dissociation of gases, 12.Dolomite, 276.Dysprosium, separation of, 56.Earth, radioactivity of the, 326.Earths, rare, 55, 58.8-Elzostearic acid, 110.Electric discharge, 48.Electrical resistance of metals, 18.Electrochemical analysis, 209.Electrodes, standard, 34.Electrolytes, influence of, on electricalendosmose, 33.strong, ionisation of, 21.Electrolytic conduction, mechanism of,19.Electromotive force, measurements of,34.Elements, chemical, homogeneity ofthe, 320Emanations, 324.Emulsions, oil, stability of, 31.Endosmose, electrical, influence ofelectrolytes on, 33.Energy quanta, 6.Entropy principle, 185.Epicamphor, 151.Epidote, 276.Esters, 82.isomorphous salts of, 57INDEX OF SUBJECTS.341Esterification, 190.Europium dichloride, preparation of,57.Felspar group, 276.Ferrocyanides, estimation of, 200.Ferrous chloride. See under Iron.Fichtelite, 277.Fluorescence, 141.Fluorine, atomic weight of, 37.Formylphenylacetic acid, ethyl ester,forms of, 92.Gadolinium, separation of, 56.Garnet group, 277.Gas analysis, 196.Gases, specific heat of, 10.Gels, formation of, 29, 30.Glucinum, estimation of, 204.Glucosamine, conversion of, intoGlucose, conversion of glucosamineGlutaconic acid, constitution of, 85.Glycine, copper salt of, 173.Glycogen, preparation of, 98.Glycolysis, 233.Glyoxaline derivatives, 175.Glyoxime, nitro-, 107.8-Gnoscopine, 157.Gold, colloidal, 54, 55.detection of, 199.estimation of, 200.dissociation and thermal con-ductivity of, 12.glucose, 95.into, 95.Hatchite, 270.Haematin, 170, 172.Haematopyrrolidinic mid, 171.Hmopyrrole, 168.Harmaline derivatives, 160.isoHarman, 160.Harmine group, 159.Haiiyne, 277.Heat theorem, Nernst's, 10.Helium, 307.Holmium, atomic weight of, 38.Honey, analysis of, 215.Hops, estimation of soft resins in, 216.Hydantoins, 175.Hydrastinine bases, preparation of,Hydrates, constitution of, 259.Hydroaromatic compounds, 143.Hydrocarbons, 73.into, 147.Hydrogels, constitution of, 259.Hydrogen, active form of, 50.dissociation of, 12.peroxide, metallic derivatives of, 60.Hydrogen ion, mobility of the, 20.Hydrogen ions, catalytic action of, 24.158.conversion of ketones and aldehydesHydrogenation, 145.Hydrolysia, 190.Ice, new forms of, 1.Ihleite, 277.Ilmenite, 278.Imino-compounds, 100.Indandiones, 123.p-Indole, 114.Inositol, isomeric forms of, 98.Iodine, blue adsorption compounds of,Ionic mobilities, measurements of, 20.Ionisation, 304.of stron electrolytes, 21.Ionium, 3gO.Iridosmine, !278.Iron, atomic weight of, 39.equilibriumof water and, 1.27.rusting of, 47.salts, constitution of hydrates of, 71.Ferrous chloride, oxidation of, 51.See also Steel.Iron, estimation of, 205.Isomerism, keto-enolic, 108, 121.Isomorphism, nature of, 265.Jalapin, examination of , 110.Kornerupine, 278.Krypton, molecular weight of, 39.Laumontite, 286.Lauric acid, sodium salt, electricalconductivity of, 32.Life, origin of, 223.Light, evolution of, in chemicalreactions, 52.Iii uids, molecular weight of, 10.Likium, nitrogen compounds of, 68.Lorandite, 278.Liinebergite, !2"8.Maltose, production of, from starch,Manandonite, 270.Manganese, estimation of, 206.Marcasite group, 278.Mass action, caesium nitrate and lawMelnikowite, 270.Mercury, atomic weight of, 37.Metals,.passivity of, 16.Meteorites, 286.Methane, formation of, 73.Methyl alcohol, detection of, 212.a-Meth ylglucosid e, amino-, con stitu ti onMethylphosphinic acid, hydroxy-, 111.Mica group, 279.97.of, 24.electrical resistance of, 18.electrical resistance of, 18.of, 96342 INDEX OF SUBJECTS.Milk, analysis of, 214.Minerals, artificial formation of, 266physical chemistry of, 255.special properties of certain, 260.heats of solution of, 260.Molecular heats, 9.Molybdenite, 279.Molybdenum, properties of, 69.Myristic acid, sodium salt, electrical8-Naphthasulphonium-quinone, 160.&Naphthol, sulphides of, 160.isoNarcotine, 156.Neodymium, oxides of, 57.Neon, 307.molecular weight of, 39.Nephelite, 279.Nicotine, estimation of, 216.Nitric acid. See under Nitrogen.Nitriles, synthesis of, 146.Nitrites.See under Nitrogen.Nitrogen, atomic weight of, 36.active modification of, 48.compounds, organic, 100.peroxide, production of, 49.Nitric acid, decomposition of, byNitrites, estimation of, 201.conductivity of, 32.light, 51.Nitro-compounds, 118.Nor-hyoscyamine, 155.Nutrition, animal, chemistry of, 252.cyclooctatetraene, 113, 144.Oedema, 240.Oil, emulsions of, stability of, 31.Oleic acid, isomerides of, 84.Organic analysis, 210.Osmosis, 33.Osmotic pressure and pore diameter,15.measurement of, 14.in concentrated solutions, 15.of sucrose, 13.Oxindones, 123.Oxozonides, 107, 148.d-Oxymethylenecamphor, use of, forOzonides, 106, 148.Palaite, 270.Palladium, atomic weight of, 38.Palmitic acid, sodium salt, electricalPassivity of metals, 16.Penninite, 280.Peracetic acid, 91.Per-acids, organic, 91.Percarbonates. See under Carbon.Perchloric acid.See under Chlorine.Petroleum, estimation of water in, 217.Phenolphthalein, constitution of saltsresolving inactive mixtures, 176.conductivity of, 32.of, 131.Phillipsite, 286.Phloroglucinol-d-glucoside, 96.Phoaphides, metallic, 60.Phosphorus, atomic weight of, 37.molecular weight of, 39.allotropy of, 42.Photochemical reactions, mechanisriiPhotochemistry, 51.Phthaleins, 131, 132.Phthalyl derivatives, 129.Phyllopyrrole, 168.Physical constants of organic comPickeringite, 280.Picolide, 174.a-Picoline, interaction of acetic an-Picramic acid and asopicramic acid,isoPinolone, 151.Plagionite, 280.Plant nutrition, chemistry of, 250.Platinum, properties of, 207.colloidal, 54.electrical resistance of, 18.estimation of, 206.Polyneuritis, 234.Ponite, 270.Potassium, atomic weight of, 36.detection of, 199.estimation of, 217.Preslite, 271.Pyrazoline group, 175.Pyrimidines, 175.Pyrophyllite, 280.Pyrosulphuryl chloride.See underSulphur.Pyroxene group, 281.Pyrrocoline, 174.of, 52.pounds, 143.hydride and, 174:methylation of, 126.Quinone-ammonium compounds, 126.Quinones, 126.Racemism, 177.Radioactive changes, influence ofdeposits, 325.recoil, 316.Radioactivity of the earth and atmo-sphere, 326.biochemical effects of, 323.Radio-elements, electrochemistry ofthe, 319,short-lived, existence of chemicalcompounds of, 317.temperature on, 317.Radium, atomic weight of, 38, 289.Kadium-6’., 314.Radium rays, chemical action of the,Radium standard, international, 290.322IKDEX OFRays, cloud method of making,visible, 303.S - and y-Rays, 296.&Rays, 300.X-Rays, 302.Reducing agents, 145.Residual affinity, 163.Revdinskite, 281.Rivaite, 271.Rotatory power, optical, factors in-Rubidium, estimation of, 206.Rutile, 281.Salicylic acid, estimation of, 213.Salmonsite, 271.Salts, complex, 173.Salt beds, 281.Salt fusions, 258.Eamiresite, 271.Sapp hirine, 282.Scammonin, examination of, 110.Scandium, researches on.56.ScoDoletin. 153.U - ~ Y S , 292.fluencing, 183.Scvhitol. 98.Selenium. molecular weight of. 39. -estimation of, 201.Shangavskite. 273.Eheridanite. 271.Sicklerite, 271.Silicates, constitution of, 259.Silicate fusions, 255.Silicon compounds, 64.organic, 111.Silver. colloidal, 54.iodide, heat of formation of, 10.Soap. nature of aqueous solutions of,Sodium hypochlorite, photochemical31.clecomDosition of, 52.thiosulphate, decomposition of, bylight. 51.Soil chemistrv. 243.Solids, specific heat of, 9.Solubility product, 23.5olutions. concentrated, osmotic pres-Spatial conjugation. 163.Specific heats, theory of, 6.Epodumene, 283.Staining . in t ra - vi t am, 225.Starch, chemistrv of, 97.Steel, analysis of, 205.Stereochemistrv, 175.Ftereoisomerides, reactions of, 187Ftewartite. 271.Ftriiverite, 283.Sucrose.osmotic pressure of, 13.estimation of, 214.Sulphates. Pee under Sulphur.Sulphide fusions, 257.sure in. 15.SUBJECTS. 343Sulphur, molecular weight of, 39.colloidal, 54.dissociation of , 12.Pyrosulphuryl chloride, 69.Sulphuric acid manufacture, 45.Sulphates, mineral, 283.EuIphur, estimation of, 202, 217.Synchysite, 284.Synthesis, asymmetric, 177.Tannin, 152.Tellurium, atomic weight of, 38.Terbium, separation of, 56.Terpenes, 143, 148.Tetramethylammonium amalgam, 138.Thermo-radioactivity, 309.Thiocarbamide, constitution of, 101,Thiophen, preparation of, 174.Thorianite, 284.Thorium, estimation of, 207.Thorium-C., 311.Thulium, nature of, 56.Titailium. estimation of, 208.Torulin, 235.Tourmaline, 284.Tridymite, 285.Triphenylmethane colouring matters,Triphenylmethyl, 137, 139.Tscheffkinite, 285.Tsumebite, 271.Tungsten, properties of, 69.Turquoise, 285.IYtramarine, colour of, 54.Uranium, atomic weight of, 39.Valency, 40, 112.Vanadium and its compounds, 68.estimation of, 208.Vapour pressure, 11.Tiscosity, 11.measurement of, 195.Pitamine, 234,Voelckerite. 2 12.Vrbaite, 272.Wa13en inversion, the, 178, e t seq.Water. colour and constitution of, 5.102.137.compressibility of, 3.specific heat of, 5.equilibrium of ice and, 1.Water analysis, 219.Weight, atomic. See Atomic weights.Weights. molecular, 39.of liquids: 10.Xenon. molecular weight of, 39.Yeast-gum, isolation of, 98.Zeolite group. 285

ISSN:0365-6217    

DOI:10.1039/AR9120900339

出版商:RSC    

年代:1912

数据来源: RSC