22 



NA TV RE 



[May 4, 1893 



the orthobaric liquid and gas ; and trustworthy data exist only for 

 these liquids and for a few others which resemble them closely, 

 ^.^. fluorobenzene, bromobenzene, &c. Also to calculate s, i.e. 

 molecular surface, it is necessary to linow the molecular volume 

 of the liquid, and to raise it to the |rds power. Hence Z'' = s, 

 or molecular surface ; i.e. it is possible to compare different 

 liquids on the surfaces of which equal numbers of molecules 

 lie. 



Measurements were made at - 89'''8, the boiling point of 

 nitrous oxide under atmospheric pressure, with ether, methyl 

 formate, ethyl acetate, and the two alcohols ; the other sub- 

 stances are solid at that low temperature. These observations 

 confirmed the rectilinear relation with the first three ; but in 

 the case of , the two alcohols evidence was obtained of molecular 

 association, as also with acetic acid. It is possible to calculate 

 the amount of association at any temperature in such cases. For, 

 as K is approximately constant for the molecular surface of the 

 " normal " liquids, the equation 



where d is the differential coefficient of an associating liquid, 

 and X is the molecular aggregation, gives the number of simple 

 molecules which have united to form a compound at the temper- 

 ature chosen. For the alcohols at -90°, and for acetic acid a 

 20°, the association of molecules approximates to (CjHjO.,)^, 

 (CHjO)^, and (C,n„0)4. 



We have thus a method by which it is possible to ascertain 

 the molecular complexity of undiluted liquids. The results 

 with the alcohols are shown to agree within resonable limits 

 with those indicated by experiments with strong solutions by 

 Raoult's method. 



It is incidentally shown in the course of the paper that there 

 is no angle of contact between liquid and glass, when the liquid 

 surface is in contact only with its own vapour. Ordinary 

 measurements of capillarity give inconstant, and probably inac- 

 curate, results, for it is not the surface tension of the liquid 

 which is measured, but that of a solution of air in the surface 

 film of the liquid. 



The paper contains tables and curves exemplifying and illus- 

 trating the statements given. 



Chemical Society, March 16. — Dr. W. H. Perkin, Vice- 

 President, in the chair. — The following papers were read : — The 

 limitsof accuracy of gold bullion assaying and the losses of gold 

 incidental to it, by T. K. Rose. Assays of gold bullion by the 

 ordinary method may be rendered more accurate by the use of 

 a more sensitive balance than is usually employed. The amount 

 of copper or silver contained in the assay piece very consider- 

 ably influences the " surcharge " ordifference in weight between 

 the gold originally present in the assay piece and the cornet 

 finally obtained. The presence of antimony, zinc, tellurium, 

 iron, or nickel reduces the surcharge by quantities which the 

 author has determined. It therefore follows that to ensure 

 accuracy check assays must be made on alloys of the same com- 

 position as those under examination. Variations in the sur- 

 charge are also caused by changes in temperature of the muffle 

 furnace used in cupellation ; a rise of 5° '" 'he temperature 

 usually worked at, viz. about 1064°, is accompanied by a reduction 

 in the surcharge of abouto'oi per 1000. If attention be paid to the 

 points enumerated above, the gold in bullion of a high degree of 

 purity can be determined within ± o'o2 per 1000, the limits of 

 accuracy having been previously considered to be ± O'lo per 

 1000. The author has estimated the losses of gold in bullion 

 assays. These are due to absorption by the cupel, volatilisation 

 in the muffle and dissolution in the parting acid. — The volatilisa- 

 tion of gold, by T. K. Rose. The author has determined the 

 loss of gold incurred on heating test pieces of the pure metal 

 or its alloys at temperatures between 1045° and 1300° under 

 various conditions. The loss of gold increases as the tem- 

 perature rises, pure gold losing four times as much at 1245° as 

 at 1090°. A large amount of gold is volatilised in an atmosphere 

 consisting mainly of carbonic oxide, whilst a small amount only 

 is lost in coal gas. A comparatively small amount of gold is 

 carried away by the more volatile metals, copper appearing to 

 exert an exceptional influence. Metals which are easily vola- 

 tilised do not appear to be completely driven off at the highest 

 temperatures attained. A larger proportion of gold is lost by 

 alloys which form flat buttons on the cupe! than by those which 

 form spherical buttons ; i it would hence seem that the condi- 

 tions which lower the surface tension of the gold button also 



NO. 1227, VOL. 48] 



raise the vapour pressure of the metal. — Note on the boiling- 

 point of nitrous oxide at atmospheric pressure, and on the 

 melting-point of solid nitrous oxide, by W. Ramsay and J. 

 Shields. Nitrous oxide boils at - 89°'8, and melts at - I02°'3. 

 — The isomerism of the paraffinic aldoximes, by W. R. 

 Dunstan and T. ,S. Dymond. The importance of the author's 

 discovery of the existence of two acetaldoximes in connection 

 with the theory of the isomerism of oximesis pointed out. The 

 behaviour of the isomerides towards reagents is very similar, 

 the acetyl derivatives prepared from the liquid and solid modi- 

 fications appearing identical. Both acetaldoximes are con- 

 verted by hydrogen chloride into the same hydrochloride. The 

 action of phosphoric chloride on the crystalline aldoxime in 

 ethereal solution at a low temperature yields a product which 

 on hydrolysis gives ammonia and acetic acid, as well as melhyl- 

 amine and formic acid ; the same products are obtained in 

 almost the same proportion from the liquid aldoxime at a 

 a high temperature. The two isomerides yield only ammonia 

 and acetic acid when treated with phosphorous chloride. Pro- 

 pionaldoxime, Et.CH : NOH, has hitherto been known only as 

 a liquid boiling at 132° ; the authors find, however, that it 

 may be obtained in two forms, the one a liquid and the other a 

 solid melting at 22°. The solid modification is converted into 

 the liquid one by heating, and the liquid form changes slowly into 

 the solid one on cooling ; this behaviour is quite similar to that of 

 the isomeric acetaldoximes. The action of reagents on the 

 acet- and propion-aldoximes is also analogous. It would appear 

 from the above results that further study is needed to establish 

 criteria of stereochemical isomerism in the case of these oximes ; 

 the authors are therefore still engaged upon the subject. — 

 The mineral waters of Askern, in Yorkshire, by C. H. 

 Bothamley. The author gives analyses of the waters 

 of four wells or springs at Askern. These waters 

 are accredited with considerable therapeutic value. — Note 

 on the distribution of acidic and alkalinic radicles in a 

 solution containing calcium, magnesium, carbonates, and sul- 

 phates ; and on the composition of mineral waters, by C. H. 

 Bothamley. The author concludes that if the question of ionic 

 dissociation in solution be put on one side, and mineral waters 

 and solutions of calcium, magnesium, and the carbonic and sul- 

 phuric acid radicles, be represented as containing salts as such, 

 the sulphuric radicle must be regarded as combining by prefer- 

 ence with magnesium and not with calcium, as is generally sup- 

 posed. — A magnesium compound of diphenyl, by W. R. Hodg- 

 kinson. Magnesium has no action on dry aniline, toluidine, 

 form- and acet-anilid and phthalanil ; phenylhydrazine begins to 

 act on magnesium at about 150°, and at higher temperatures the 

 reaction becomes very violent. Aniline, benzene, ammonia, 

 and nitrogen are evolved and a solid whitish substance contain- 

 ing the metal remains in the retort ; on heating this residue an 

 oil is obtained which contains diphenyl. These results sug- 

 gest the presence of magnesium diphenyl. — Note on acetanhydro- 

 citric acid, by F. Klingemann. The author criticises the recent 

 work of Easterfield and Sell on this acid. — The dissolution of 

 gold in a solution of potassium cyanide, by R. C. Maclaurin. 

 The author shows that the dissolution of gold in potassium 

 cyanide solution is conditioned by the presence of oxygen, and 

 that the amounts of oxygen absorbed and of gold dissolved are 

 in the proportion indicated by Eisner's original equation — 



4Au + 8KCN -f O2 -f 2H„0 = 4AuCN, KCN -I- 4KnO. 

 Furthermore, it is sho" n that the rate of dissolution varies with 

 the strength of the solution and that it passes through a maxi- 

 mum in passing from dilute to concentrated solutions ; this 

 variation is traced to a decrease in the solubility of oxygen in 

 solutions of potassium cyanide as the concentration increases. 



March 27 — Annual General Meeting. — Prof. Cnim Brown, 

 F.R.S., President, in the chair. — The President delivered an 

 address in which he discussed «the history of the phlogistic 

 theory and its gradual displacement by more modern views. 

 The iialance-sheet for the past year was then presented, and the 

 usual votes of thanks passed. A ballot was then taken for the 

 election of officers and Council for the present year. 



Mathematical Society, April 13.— Mr. A. B. Kempe, 

 F. U.S., President, in the chair. — The President, calling atten- 

 tion to the title of a paper he had read at the January meeting 

 on the application of Clifford's graphs to ordinary binary 

 quantics {atile, p. 382), .'■aid that the subject being there regarded 

 from Prof. Clifford's point of view, he had, following the pre- 

 cedent set in a paper by the late Mr. Spottiswoode on Clifford's 



