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Proceedings of the Chemical Society, Vol. 9, No. 120 |
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Proceedings of the Chemical Society, London,
Volume 9,
Issue 120,
1893,
Page 37-50
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Iswed 28/2/1893. PROCEEDINGS OF THE CHEMICAL SOCIETY. No. 120. Session 1892-93. February 16t,h, 1893. Professor A. Crnm Brown, F.R.S., in the Chair. It was announced that the following changes in the Council mere proposed by the Council :-As President : Professor II. E. Armstrong, vice Professor Crnm Brown. As Vice-presidents : Dr. E. Atkinson and Mr. C. O’Sullivan, Y~CP Professor Hartley and Nr. Warington. As Secretary : Professor Dunstan, vice Professor Armstrong. As ordinary members of the Council : Messrs. C. F. Cross, Beimard Dyer, D.Sc., Lazarus Fletcher, M.A., and W. A. Shenstone, vice Mr. H. Bassctt, Professor Ferguson, Mr. J. Heron and Mr. S. U. Picliering. Messrs. Holland Crompton, T. S. Dymond and Dr. T. A. Lawson were appointed to audit the Fociet,y’s acconnt’s.Ordinary certificates were read for the first time in favour of Messrs. Lawrence Augustns Baine, Dipton, Lintz Green, Newcastle- on-Tyne ; George Clayton, School of Pharmacy, 100, Burlington Street, Manchester ; Robert George Grimwood, 41, Lady Margaret Road, St. John’s College Park, N.W. ; Alfred Rowland Gower, 39, Stafford Street, Barrow-in-Furness ; Hooper Albert, Dickinson Jowetdi, 3, Fern Bank, Lancaster ; Herbert Lloyd, Philadelphia, U.S.A.; Edmund George Lamb, 29, Great Cumberland Place, W.; James Mason, Cambois, Blyth, Northumberland ; Henry John Nonson, 15, Palace Street, Buckingham Gate, London, S.W. ; William Henry Oates, Broomhall Park, Sheffield ; S. Parrish, 15, Fenton 38 Street, Woodlioase Lane, Leeds ; Frank P.Vandcnbeigh, B.S., M.D., Buffalo, New York ; A. F. Watson, 11. York Place, Edinburgh. Tile following 1~7ei-e duly elected Fellows of the Society :-John Pedrozo D’Albuquerquc ; William Thonias Boone ; John Edwin Rrockbank ; Edward Brooke ; George Tlavej-; Daniel 0. Sydney navies ; Charles Dreyfns, P1i.D.; Samiiel Felix Dufton, B.A., 11.Sc.; Francis P. Dnnnington : A1ex;inder Stanlcy Elmore ; Frederick George Fuller ; Albin Hnlley ; George Nevi11 Huntly ; Arthur John Heath ; Wesley Lambert ; Cliarles If. Lnx-mol~c; Fred. Marsden ; Hcrbei-t Bloome Mole ; Williani J. Ma~tin, ;Juu., M.D. ; Robert Henry Owen ; Charles Plntt, A.C. ; Janics Robert Thackrah, M.A., P1i.D. ; Charles Thomas Tyrcr ;John William Towers ; John Charles IJmney ; Henry C.White : Willougliby JVnlkc~; Chilyles E. Waite ; TVilliRm Ernest Wheclcr. Of the following papers those marked* wei~trrnd :-@113. “Note on the preparation of platinous chloride, and on the inter- action of chlorine and mercury.” By W. A. Shenstone and C. R. Beck. In a paper read before the Society last year (C. S. Trans., 1892,445) we gave the results of the analysis of the gas evolved on igniting various specimens of platinons chloi%ie in z‘acuo, showing that in every case very sensible qnantities of hydrogen chloride and oxygen were present. The greatest amount of impurity was found in a specimen derived from the salt prepared by heating hydrogen platinichloride in uucuo in a tube containing solid potash, as recommended by Pigeon (Compf.yeizd., 1892).This last fact and Pullinger’s description of his method of preparing anhydrous plat.inic chloride (C. S. Tyans., 1892, 422) led us to conclude that probably a more satisfactory pro- duct, at any rate as a source of chlorine, would be obtained by heating hydrogen platinichloi*ide at a high temperature in a current of dry hydrogen chloride. ExTeYiinent I.-Some hydrogen platinichloride was heated at the boiling point of mercury in a current of dry hydrogen chloride during 15 hours, and the hydrogen chloride was then displaced by dry air. A part of bhe product was ignited in vaouo, and the gas which was given off was examined in the manner previously described (Zoc. cit.). We found that the residue from the action of mercury only amounted to 0.156 per cent.This residue was partly soluble in water as before. The gas ma,de in this way therefore contained 99.84 per cent,. of chlorine. Experiment 11.-A portion of the product of the first experiment was heated in a current of dry hytll-ogen chloride at about 300" during many hourd, by yiaciiig it in a glass tube sui*rounded by a well-fitting glass jacket iinmersed in a bath of molten nitre; at the end of the operation, the hyclrogeii chloride was expelled by means of dry air. The process was rather difficult to carry out, as the coin-plete decomposition of thz salt easily takes plwe if the temperature too much exceeds the melting point of silver chloride, some decompo- sition occurring even at that tempei*ature. A portion of the product of this experiment was placed in a glass tube, which was then exhausted as in our previous experinlents ; it contained no drying iiiate~ial, but both the tube and its contents were heated to drive OE moisture.Chlorine was generiit ed from the chloride by igniting it, i?i TCICUU, and the residual platiiiunl liaviug beeii removed, one end of the tube was broken nnder niercury. Although we had intentionally neglected to dry the gas, we were at oiice struck with the fact that the action between this sjnmplc of chlorine and mercury was decidedly less actire tlittn in the case of any of the specimens previously examined, and when the uction of meicury was at an end so little 1-csidue was left that its nnnlysis by the method formerly clescribecl seemed useless.The part of tlle narrow tube which had contained the residual gas was therefore cut OE and calibrated : it was thus found that the rcsidue mioiinted to oiily 0.06 per cent. of the gas taken. The residue was partly soluble iii water. We have not deteiamined the total chlorine in the platinous chloride iiiade iii this way, as we do not think it coiisisted of pure platinous chloride ; it probably contained a little platinum, but as a source of chlorine it seems to be very superior to the product of the iiioro fbmiliar processes. We bavo p~evic~uslysuggcsted tliat th markocl activity of even the most carefully dried chlorine towards mercury is probably due to thc presence of impurities in thc gas.The sluggish action of chlorine and mercury observed iu our secoiid experiment, in which the chlor-iiic employed, though not quite clry, contained much less hydrogeii uliloridc and oxygen thm my that wc have prcviously examined, is therefore interestiiig aid suggestive. Shortly after tlie publicatioii of our formel. payer on this subject, Professor Victor Meyer called our attention to the fact that in his later experiments on the density of chlorine lie assured hiniself that the other gases present in the chlorine employed were insufficient in quantity to materially affect the chief conclusion he drew from his results (Be)..,13,1721). We are anxious to mention this, although we made no direct referewe to the subject in our paper, as one of our remarks might relay pcssibly bo supposed to imply the contrary.D~SCIJSS~ON. Mr. GROVEShaving asked whether the authom had made any furthe13 experiments in the directicii of fractionally evaporating liquid chlorine, Mr. SHENSTOSE,in reply, stated that by fractionating the liquid they had obtained chlorine which, wheii tested by mercury, was found to be almost as nearly pure as that obtained from platiiioub chloride. This chlorine, however, acted rapidly on mercury, even after it had beon highly heated, and he mas inclined to snspect the presence of traces of oxy-compounds in it. It was worth while men- tioning that recently roasted chlorine does not appear to cause the adhesion of mercuyy to glass in anything like the same degree that ozone or uiiroasted chlorine does.Whether this ia due to a change in the gas or to a change on the surface of the glass he could not say. *114. “The action of phosphoric anhydride on fatty acids. Part 111.” By F. Stanley Kipping, Ph.D., D.Sc. Results of an investigation of the behaviour of some of the fatty acids with phosphoric anhydride have been commuliicated to the Society in previous papers (Trans., 1890, 532, 980) ; it is now shown that caprylone, (C,H,j)2C0, nonylone, (CeH17),C0,and myristone, (C,,H27),C0, can be easily prepared from the corresponding fatty acids and phosphoric anhydride. The hydroxitnes of these ketones, the sec0ndar.y alcohols obtained from the ketones by radiiction and the acetyl derivatives of some of the alcohols have been prepared and characterised, and are described in the papers.It is also shown that mixed ketones of the general formula RnC0.R’ are produced when a mixture of two fatty acids is treated with phosphoric anhydride at u moderately high tempera- ture ; the mixed ketone is accompanied by two simple ketones, just as is the case when a mixture of the barium salts of two fatty acids is submitted to dry distillation. The question of the existence of isomeric modifications of the liydroximes of fatty asymmetrical ketones is briefly referred to. It would appear from thc results described in this paper and from those already recorded, that treatment rith phosphoric anhydride is one of the simplest and most rapid methods by which a fatty ketone of the general formula (C,,H2,z+1)2C0can be prepared from a fatty acid CltH2tL02,the product being easily isolated and the yield fairly good, especially in the case of the higher acids.“115. “Regularities in the melting points of certain paraffinoid com- pounds of similar constitution.” By F. S. Kipping, Ph.D., DSc. Having obtained considerable quantit,ies of many of the fatty ketones (C,H,,+,),CO, the author was able to prepare and charac- terise tbeir more important derivatives ; e.g., various members of the series of hydroximes R2C:NOH, secondary alcohols R,CH*OH and ethereal salts R,CH*OAc. Attention is drawn to certain regularities observed on contrasting the melting points of these compounds; it, is also pointed out that the melting points of all ketones of the general formula C,H,,O cannot be calculated by means of the formula suggested by Mills (Phil.Mug., 1884,), inasmuch as isomeric ketones frequently melt at different temperatures. DiscnssIoN. Mr. A. R. LINGdrew attention to the similarity in the melting points of many chlorinated derivatives of p-benzoquinone and of the corresponding quinols and their diacetyl derivatives as compared with those of the analogous bromo- and chlorobromo-compounds. The agreement seems to be wanting in the para-dihalogen derivatives, but in all other cases, it is sufficiently close to be remarkable. The displacement of chlorine by bromine is usually attended by a rise in the melting point, but metachlorobromoquinone and its derivatives melt at slightly lower temperatures than the corresponding dichloro- compounds.Only two iodoquinones are known, but their melting points do not exhibit the least similitude as compnred with those of their analogues. 116. ‘(Some relations between constitution and physical constants in the case of benzenoid mines.” By W. R. Hodgkinson and Leonhaxd Limpach. A study of the formyl and acetyl derivatives of certain homologues of aniline shows, amongst other things, (a) that the entry of alkyl groups int-o the nucleus affects the melting and boiling points in a regular manner ; (p) that the conversion of formyl into acetyl also involves an alteration in physical properties in extent the same as that produced by introducing CH, into the nucleus in an ortho-or paya-posit*ion relatively to the amido-group ; and (y) that the same (or any?) alkyl group entering the nucleus in the mcta-positions has no effect on melting or boiling point.Several numerical regularities are also apparent. Thus, taking the melting points of the methylamidobenzenes as first examples :-Formanilid ......... 46” Acetanilid ......... 114” Formylxylid.. ...... 76 Acetxylid ......... 144 --Difference ...... 30 Difference ..... 30 42 That the introduction of methyl into the meta-position has no influence on the melting point is shown by the fact that the following substances melt at the same temperature within a degree :-.Acetmesidid................ NHAc :Me :Me :Me = 1:2 : 4 : 6. M. p. 216" Acettetramethylamiciobenzene. NHAc : Me :Me : Me : Me = 1:2 :3 :4 :6. M. p. 215O. Acetpentamethylamidobeiizene NHAc : Me : Me : Me :Me :Me =1:2:3:4:6:6. M.p. 214-2 15O. That the CH, of the acetyl has an effect on the ortho-and para- position in the iiucleus seems evident, as 1:2 :4-formylxylid has the same melting point as acetanilid (114"). Similarly, 1:3 :5-acetxylid and I :2 :3 :4 :5-tetramethylformanilid have the same melting point', viz., 144'. The tetramethylformanilid can be imagined as built up of 1:3 : 5-formylxylid and 1:2 :4-formylxylid. Melting point of 1 : 2 : 4-formylxylid ............ 113.5" 9, 1:3:5 ............ 76.577 190.0 7, formanilid.............. 4G.0-7) 1:2 : 4 : 5-tetramethylformanilid. 144.0 Formylmesidid and acetylxylid, NHAc : Me :Me = 1: 2 : 6, have the same melting point (176"). In this case, the influence can only be exerted on one positioii (the para-), as both the ortho-positions are occupied. Similarly, formylmesidid and 1:2 :3-acetmetaxylid both melt at about 176", and acetmesidid and 1:2 :3-propionylxylid at about 216". As an example of numerical relations, taking formyl compounds, formanilid m.elts at 46", pentamethylamidobenzene at 217" : now the melting point of formanilid (46") pZus 2(34) = 114", which is the melting point of formylmetaxylid, NHF :Me : Me = 1:2 :4 ; again, the melting point of formanilid plus 4(34) = 182", which is the melting point of XHF :Me : Me : Me :Me = 1:2 :3 : 4 :6.The formyl compounds of aniline, p-toluidine, 1 :2 :4-metaxylidine and mesidine form a series:-Aniliue (46"); p-toluidine (52") ; 1: '2 : 4-xylidine (114i") ; 46 =46+6 46 + 6 + 62 mesidine (176"), &c. = 46 + 6 + 2(632). 43 Similarly in the case of the corresponding acetyl compounds :-Aniline (114') ; p-toluidine (147") ; 1:3 : 4-xylidine (181") ; = 46 + 2(34) = 46 + 3(34) 46 + 4(34) mesidine (216'). 46 + 5(34). The different positions are not in all cases of equal value. Thus, pentamethylformanilid melt's at 217", and 46 + 5(34) = 216', which might indicate equality of bhe methyl groups, or rather of the positions in benzene. But when CH, is introduced into 1:2 :4-xylidine to form mesidine, the melting point rises 62", so that the formula becomes- 2 x 34 = 62" 1 x 62 = 62 1 x 46 = 46 -176 On introducing methyl into the meta-position, the melting point rises to 182" in the case of 1-amido-2:3 :4 :6-tetramethylbenzene. The CH, groups appear again equivalent.Again, taking away a methyl in the ortho-position leaves a pseudo-Me ~cumidine, I I , melting at 121", a, drop of 62". Me\ /gH2 These examples will suffice at present to show that definite relations between melting points apparently do exist in the case of methyl-arnidobenzenes. The authors have examined a number, and are gradually preparing other, alkylamidobenzenes containing ethyl, butyl &c., and find also great regularities from which they hope to be able to state a general law.Many of the published data relating to melting points undoubtedly require careful revision. "117. " Electrolysis of sodic ethylic camphorate." By J. Walker, D.Sc. By electrolgsing sodic ethylic camphorate, prepared by the direct union of camphoric anhydride and sodium ethoxide, the author has obtained the ethylic salts of two new acids, C8H1,*COOH and C,,H,,(GOOH),, which he proposes to term campholytic acid and camphothetic acid respectively. Camphothetic acid is a colourless, crystalline solid melting at 132". 44 It behaves as a saturated bibasic acid, forming well characterised crystalline salts. Campholytic acid is a monobasic, unsaturated acid. It boils at 240-242", and is lmvorotatory.Its ethylic salt boils at 212", and is dextrorotatory. Both readily take up bromine in the cold, forming dibromides. The dibromo-acid, C,H,,Br,*COOH, is a white, crystal- line solid which melts at 110". Its alkaline salts at once decompose in aqueous solution according to the equation CsH,,Br,*COONa = C,H,,Br + CO, + NaBr, the compound C8H,,Br being unsaturated, readily uniting with bromine in the cold. It is pointed out that from the nature of the electrolysis and the above mentioned decomposition of the dibromo-acid, camphoric acid itself must contain the group H$-COOH -q-COOH' DISCUSSION. Dr. COLLIEhaving pointed out that the method by which Dr. Walker had obtained campholytic acid was such that there was little probability any fundamental change occurred in the camphoric mole- cule during the process, Dr.ARMSTRONGsaid that electrolytic oxygen was probably by no means a mild agent, and he thought that in the present instance, as well as in the cases studied by Crum Brown and Walker, it was not improbable that the change was brought about by oxidation : the formation oE unsaturated acids especially favoured this view, as these might be regarded as resulting from the displace- ment of carboxgl by hydroxyl and the subsequent separation of water, or an analogous set of change&. Dr. Walker's ingenious application of Fittig's conclusions was open to question, on the ground that we knew very little at present of the behaviour of closed chain bromo- acids; moreover, the fact that camphoric acid did not yield a fluoresce'in appeared to preclude the idea that camphoric acid was an acid of the succinic type.He was of opinion that, on the whole, the evidence was in favour of the view that camphoric acid was an acid of the glutaric type, and that Dr. Walker's acid was probably a tetrahydrometaxylene derivrttive containing the carboxyl in one of the methyls. Dr. WALKER,in reply to Dr. Armstrong, stated that he did not consider it probable that the formation of either the synthetic or un-saturated ethereal salts during the electrolysis was due to oxidation at the anode. Murray had shown in the case of the electrolysis of potassium acetate that there was no sort of proportionality between complete oxidation to carbonic anhydride and "partial oxidation " to ethane, as niight be expected if the formation of ethane was due to oxidation. The conditions of the electrolysis found most favourable for the production of synthetic products were such as would almost ensure corqlete oxidation of the dissolved substance if the primary action was the decomposition of water into oxygen and hydrogsn.“158.“The hydrates of hydrogen chloride.” By S. U. Pickering. The determinations of trhe densities of solutions of hydrogen chloride made by Kolb, and also some made by the author, show a strongly marked break indicative of the presence of a trihydrate. They are represented by an appreciably straight line from 0 per cent. up to the composition of that hydrate (40 per cent.), after which the deviation from straightness is very considerable.On performing a series of freezing point determinations the trihydrate was obtained in large, transparent crystals meIting at -24.9”; this melting point is lowered by the addition of excess either of water or of acid. This hydrate and the dihydrate, already isolated by Pierre and Puchot, are the only crystalline hydrates which were obtained. The densities indicate the existence of a change of curvature of a very minor character at a point corresponding to the composition of a hexhydrate, and similar indications are noticeable both in Berthelot’s and Thomsen’s heat of dissolution determinations. The author’s freezing point determinations can afford no evidence for or against such a hydrate, on account of there being a change in the crystal- lising substance at the point in question, but they indicate the existence of a decahydrate.Roscoe and Dittmar’s determinations of the influence of pressure on the composition of the boiling acid suggest the presence of an octohydrate. It seems, therefore, probable that these three hydrates exist in solution, and that they are com- paratively st,able, as solutions of acid of strengths between the hexhydrate and the decahydrate may be dist.illed with very little change in spite of great variations in pressure, and are altered in composition to a very small extent by tlie passage of a current of air through them at temperatures between 0”and 100”.139. “A new base from Corydalis cava.” By James A. Dobbie, M.A., D.Sc., and Alexander Lauder. The authors describe under the name of corytwberine a new alkaloid which they have obtained b-j- exhausting crude corydnline with hot water; it crystlallises from a hot aqueous or alcoholic solution in beautiful silky needles, soluble in cold solutions of sodium hydrate and ammonia, moderately soluble in benzene, and nearly insoluble in ether and chloroform. When heated it begins to blacken about 800",and then slowly decomposes without melting. Its aqueous and alcoholic solutions are slightly dextrorotatory. Analyses lead to the foimnla ClgHzsN04. The chlorhydride, C1gH25NOa*HC1, is obtained in small, well formed, rhombohedra1 crystals when a solution of the base in chlorhydric acid is evaporated to dryness.The sulphnte, is(C,gH25N04)2*H,S04, obtained by the interaction of the chlor-hydride and the calculated quantity of silver sulphate. The platini-chloride, (C,,H2,N04)z*H2PtC16,is precipitated in the form of a pale- yellow, crystalline powder, slightly soluble in water, on adding hydrogen platinichloride to a solution of the chlorhydride in water. Corgtuberine is only soluble to a slight extent in methyl iodide, but the methiodide, C,6Hz,NOa*CH31, can be prepared by digesting an alcoholic solution of the alkaloid with methyl iodide during sercml hours. When treated with concentrated solution of hydrogen iodide, one molecular weight of corytuberine gives two molecular proportions of methyl iodide, showing that, only two of the oxygen atoms are present as methoxy-groups ; corydaline on the ot,her hand has all its four oxygen atoms in this form of combination.The authors also give some notes on yet another alkaloid which they consider to be distinct not only from corydaline and corytuber- ine but from all the bases of CorydaZis cava hithert'o described. EXTRAMEETING.-February 20th, 1893. The Right Hon. Lord Plaj-fsir, K.C.B., LL.D., F.R.S., Vice-president, i 1-1 the Chair. Kopp Memorial Lecture. 120. " The life work of Hermann Kopp." By T. E. Thorpe, D.Sc., F.R.S. Kopp was barely 32 years of age when, so far bad;. RS 18-19,hewas elected a Foreign Member of the Society. Born, October 30, 1817, at Hanau, at 18 he proceeded to Heidelberg, where he studied chcm-istry under Leopold Gmeliii.He graduated at Marburg in 1838, the thesis which he presented being on "A method of predetermining the density of the oxides," a proof that he had already, when barely 21 years of age, been attracted by the problems which were to con- stitute the chief experimental labours of his life. From Marburg he went to Giessen, where, at Liebig's itistigation, he studied tthe mode of decomposition of mercaptan by nitric acid, practically the only investigation in pure chemistry that Kopp ever published. In 1841 he became Privat-Docent at Giessen, and was appointed Extraordinary Professor in 1843. In 1852, 011 Liebig’s removal to Xunich,Kopp and Will were together made Ordinary Professors, but after a year he resigiied the whole control to his friend and colleague, continuing, however, to work iu the laboratory.He remained at Giessen nearly five-and-twenty years, and all his most important ex- perimental work was done there. In 1863 he accepted a call to Heidelberg, and repeated attempts to induce him to accept a posi-tion elsewhere were unavailing ; “ even Bunsen alone,” he was wont to say, “keeps me fast in Heidelberg.” Kopp is best known to the literary world by his History of Chew isti-y,the first volume of which appeared in 1845, and the fourth and last in 1847. Hofmann, his life-long friend, has told us that by the publication of this classical woi-k, Kopp-then barely 30 years old- suddenly found himself famous.Much of the later historical matter he published grew out of materials collected for the preparation of an enlarged and improved edition of the great work, which Kopp postponed year after year in the hope of being able to make a further study of certain special periods. On the death of Berzelius, in 1548, the leaders of the Giesseii school determined to carry on the work which had mainly occupied the closing years of his life, and established Liebig and 11opp’s Juhresbericht, which Kopp continued to edit until 1862. In 1851 he joined Liebig and Wohler in the production of the A4nnuZen der Chernie unci Pl~uri~zucie,and his name appears on the title page of no fewer than 190 voliimes of this famous periodical.He also found time to write his Introduction to Crystallogruphy, the section on Theo- retical Chemistrj in Graham Otto’s Lehrbuch, and not a few minor essays. As ail investigator, he occupies an almost unique position, the one consistent purpose of his work having been to establish a connection between the physical and chemical nature of substances-to prove, in fact, that all physical constatits are to be regarded as functions of the chemical nature of molecules. When he began his enquiries very few boiling points were known eren approximately ; the thermal ex- pansions of barely half-a-dozen liquids had been measured, and the very methods of making such measurements with precision had to be worked out. In fact, at the outset of his investigation, he found the physical constants with which he was more immediately corrcerned very much as Berzelius found Dalton’s values of the relative weights of the atoms.His more important memoirs naturally fall into comparatively few groups :-viz., 1,those concerning the relations between the relative densities of substances and their molecular weights ; 2, those treating of the relations between boiling points and chemical composi- tion; and, 3, those relating to the specific heats of sdids and liquids. In nothing was his originality and ingenuity niore strikingly moni- fest than in the construction of his apparatus; to a great extent hc was his own instrument maker, and his materials were for the most part glass and cork ; but no Japanese worker with his few and primi- tive tools evein produced results which in point of delicacy, finish and accuracy surpassed those which Kopp obtained by means of his simple contrivances.In discussing Kopp’s variou s investigations, Professoy Thorpe first coiisiders his work on specific heats and its bearings. His observations on the relation of boiling point to compositioii are next discussed, and the various later observations of other enquirers are taken into account. Kopp’s researches on specific volumes form the last section of tlie lecture, this subject being dealt with in a very comprehensive manner, not only Kopp’s work but also that of subsequent observers being fully taken into account, the historical development, of the subject being explained and abnndantly illustrated.It is pointed out that by the examination of the very large quan- tityof experimental material which is now before us, we are driven to the conclusion that molecular volunie is not a purely additive pro- perty. There is no longer room for doubt that the molecular volumes of substances are affected by fala more conditions than we have hitherto taken cognizance of. The value CH2 = 22 has no other significance than as expressing the average increment in volume in successive members of an homologous series : it is doubtful whether even this mean value is correct ; later observations appear to show that the value augments as the series is ascended. The relatiou C = 2H no longer applies to carbon compounds in general.What is true of carbon and hydrogen is equally true of oxygen, whethe11 :LY carboiiyl or as hydyoxyl oxygen : no definite or uniform values cau bc: assigned to oxygen such that the niolecultti- volume of a liquid call be np~ioridetermined. The values given by Kopp are simply meail values, but the actual volumes are affected by coriditions of which its yet we have no very precise knowledge or any certain means of measuring. The values for other elements arc aff-’ected by the same considerations : that of chlorine, for example, as it is obtained on the assumption that the values for carbon and hydrogen are comtalit. At the conclusion of this section reference is made to Kopp’s critical memoir on the subject, published in Liebig’s ,41~nuZestshortly before his death, discussing the outcome of the various researches which followed his own : we rise from its perusal, says the lecturer, with the conviction that after all the work sunirnurised takes us bnt 49 little beyond the threshold of the fundarnent'nl truth of which Kopp was the first to perceive the indication.Lord Playfair, in the course of his remarks at the conclusion of the lecture, mentioned the fact that he had known Kopp 52 years ago- they were pupils together niider Liebig. He was with him when he was making his first specific volume determinations, and Kopp daily came to him to discuss the results. In the historical survey given by the lecturer there seemed to be one name missing, that of Dalton ; it was by reading a memoir by Dalton on specific volumes of solu-tions-% memoir which was rejected by the Royal Society and pull-lished privately-that he had been led to pay attention to t,he subject: this memoir was full of suggestions.Dr. Gladstone had known Kopp as far back as 1847-48, when he worked in Liebig's laboratory. Kopp's individuality undoubtedly in those days exercised a strong influence over the students. Professor Rucker spoke of the publication oE memoirs desci-ihing the life work of men like Kopp and discussing its bearings and development as a very happy idea on the part of the Society and as likely to be of great value to scientific workers. HOFMANN MEMORIAL LECTURE. An extra meeting of the Society will be held on Friday, May 5t8h, 1893, the anniversary of the death of A.W. von Hofmann, when addresses will be delivered by the Right Hon. Lord Playfair, K.C.B., F.R.S., V.P.C.S.; Sir F. A. Abel, C.B., F.R.S., V.P.C.S.; Dr. W. H. Perkin; F.ES., V.P.C.S. Meetings of the Society during the remainder of the Session. Thursday, March 2, 16. *Monday, ,, 27. ?Thursday, April 20. ,, May4,18. $Friday, 5.3, Thursday,June 1,15. * Annual General Meeting. + It is proposed that there shall be no meeting in Easter week. $ Hofmann Memorial Lecture. 50 At the next meeting, on March 2nd, the following papem will be read :-“ Notes on optical properties as indicative of structure ” (post-poned). By H. E. Armstrong. “ The ethereal salts OF active and inactive glyceric acid.” Ry Professor P. Frankland and J. MacGregor.‘‘ The limits of accuracy of gold-bullion assay and the losses of gold incidental to it. The volatilisation of gold.” By T.K. Rose. “ The interaction of alkali-cellulose and carbon disulphide. Cellu-lose thiocarbonntes.” By C. F. Cross, E. J. Bevan and C. Beadle. “A new atomic diagram and periodic table of the elements.” By R. M. Deeley. HARltISON AXD SONS, PRINTRRS IN ORDINARY TO ’HER MA.JESTJ’, ST, 3fIARTIX’S LANE,
ISSN:0369-8718
DOI:10.1039/PL8930900037
出版商:RSC
年代:1893
数据来源: RSC
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