vo prnvcil 

 iouiul tliat 

 moloc'iilur 

 Li8 capabli" 

 :)9ec()iuliivy 

 loinpiunds 

 1)V wliicU 



Initx. 



mil (if till' 

 I" uiiivcisal 

 1 till' mode 

 spt'i'.-ion of 

 s clu'iniciil 

 ) the Mtiuly 

 conimimi- 

 I versify, by 

 f tliis puiiur 



P > 



11'7 I 

 100 



rJ 



L'l'6? 



I8:i , 



24-7 



7-8:. 

 2;v4: 



12'1 



noi 



74 

 nlioiit G 1 



, i;v2 



44 

 130 

 l.iO 

 HI 

 20-4 



I 27'U.' 



18-fi.' 



! 24-V. 



I',)'4 



'.)'8 



21-;! 



TRANSACTIONS OF SECTION B. 



675 



l^osldes tlie increased data thus obtninod, fresh li|rht has been thrown on 

 (1) 'Hh? phv'-ical question nt tlie basis of the inquiry. Additional proofs have 

 biM'n piven that specific refraction is constant (or nearly so) notwithstanding 

 solution or chan<?e from the f^aseous to the liquid or solid condition. (2) The 

 Tefnietion equivalents of the elementary bodies. A revision f tlio old list (' Phil. 

 Trans.' 18()i)) in the lifjlit of our present knowledfre has led to the results embodied 

 ill the table ^iveu above. Many of the figures will doubtless require future modi- 

 :iicatiou. (•'») The cliemienl structure of many compounds, especially araoiifr organic 

 bodies rich in carbon. Some of these deductions have already become the subject 

 of controversy in the scientific journals of the (,'oiitiiient. 



o. On the Blffumm of Metals. Bij Professor W. Ciiandlei; RoiiDRis, i^.J^.^S*. 



6. Oil. some Tlienomend of Solntion iUnstnitt^d hy the case of Sodium 

 Sidphate. By Professor William A. Tilijex, B.Sc., F.B.S. 



From a study of the solubility of sodium sulphate in water at temperatures 

 above 100° C, the autlior (in conjunction with Mr. Shenstone) has arrived at 

 the conclusion that at these high temperatures the salt dissolves in the anhydrous 

 state. In order to determine whetlK^r this salt dissolves in water at lower 

 temperatures in the anhydrous or in the hydrated state he has made a series of 

 calovinutric measurements of the thermal changes which attend the act of solution 

 ■of Na.SO, in water at tenqiuratures below and abovi; y;J°-o-4°, the critical point in 

 th' curve of solubility. The following are the chief results : 



Calorimetric etlect, C, of dissolving Xa.SOj in n molecules of water at t°. 



n. 

 100 

 100 

 100 

 100 

 100 



31-70 

 3o-40 

 42-8o 

 40-10 

 uo-00 



a 



1740 

 1522 

 1342 

 1071 

 985 



These figures esta])li.shthe fa'-t that by dissolving anhydrous sulpliate of sodium 

 in water at temperatures above 33°-34° the therinai change is still positive, 

 although a diminishing quantity, and hence that the act of solution is still attended 

 at these temperatures by chemical combination between the salt and a ]K)rtion of 

 the water. These results when plotted out give a line which is nearly parallel 

 with the solubility curve between these limits of temperature. 



7. A Theory of Solution. By W. W. J. NicoL, M.A., B.Sc. 



This paper contained a r('.v«Hu' of the experimental evidence accumulated by 

 the author in support of his theory, a comjdete enunciation of which was given in 

 a paper read before the Royal Society of Edinburgh in January 1883, and pub- 

 lished in tht! ' Philosophical Magazine ' for February of the same year. 



f^. On J'lvaporation and. Dissociation, 

 By Professor "Wii.lia.m Ramsay, Bh.D. and Sydney Youxg, B.Sc. 



The authors described experiments made with the object of ascertaining whether 

 the cidncideuce of the curves whicli re]iresen( the vapour j)ri\':siires of stable solid 

 and liquid substances at (litferent temperatures with those indicating the maxinuiiu 

 temperatures attainable by the same substances at different pro-sures, when 

 evaporating vitli a free surface, holds good also for substances which dissociate in 

 their passage to tlit> gaseous state, 'fhe substances examined were chloral hydrate, 

 nmiiioniuni carbonate, plithalic acid, succinic acid, aldehyde ammonia, aitnnoniiim 

 chloride, nitric peroxiile, and acetic acid. It was found that with chloral hydrate 



X X 'J 





i; l 

 ■si' 



