185*1.] 



Some Suggestions regarding Solutions. 



305 



Pedler, Professor Alexander, 



F.C.S. 



Reade, Thomas Mellard, F.G.S. 

 Roberts, Ralph A., M.A. 

 Rutley, Frank, F.G.S. 

 Seebohm, Henry, F.L.S. 

 Shaw, William Napier, M.A. 

 Sherrington, Charles Scott, 



M.B. 

 Stebbing, Rev. Thomas Roscoe 



Rede, M.A. 

 Stevenson, Thomas, M.D. 

 Stewart, John Heron Maxwell 



Shaw, Major- General R.E. 



Thompson, Professor Silvanus 

 Phillips, D.Sc. 



Thomson, Professor John Millar, 

 F.C.S. 



Thornycroft, John Isaac, M. Inst. 

 C.E. 



Tizard, Thomas Henry, Staff- 

 Commander R.N. 



Take, Daniel Hack, M.D. 



Veley, Victor Hubert, M.A. 



Waller, Augustus D., M.D. 



Woodward, Horace Bolingbroke, 

 F.G.S. 



Young, Professor Sydney, D.Sc. 



The following Papers were read : 



" Some Suggestions regarding Solutions." By WILLIAM 

 RAMSAY, Ph.D., F.R.S., Professor of Chemistry in Univer- 

 sity College, London. Received February 16, 1891. 



The brilliant presidential address of Professor Orme Masson at the 

 /hemical Section of the Australasian Association for the Advancement 

 Science marks a distinct advance in our ideas of solution. The 

 lalogy between the behaviour of a liquid and its vapour in presence 

 each other and of a pair of solvents capable of mutual solution is 

 striking as to carry conviction. The resemblance of the liquid- 

 ipour curve, with its apex at the critical point, to the solubility 

 irve, with its apex at the critical solution point, appears to me to 

 wove beyond cavil that the two phenomena are essentially of the 

 line nature. The address will take rank along with van't Hoff's 



sical paper on " Osmotic Pressure." 

 There are two other phenomena, which, it appears to me, are made 

 lear by the ideas of Professor Masson. The first of these has 

 jference to supersaturated solutions. The curves (published in 

 'Nature,' vol. 43, p. 348, Feb. 12, 1891) showing the analogy 

 Btween liquid-gas and solution curves, are isobaric curves, or, more 

 Jrrectly, they represent the terminations of isobaric curves in the 

 2gion of mixtures, where, on the one hand, a liquid exists in 

 jresence of its vapour, and, on the other, one solvent in presence of 

 lother (for both solvents play the part of dissolved substances as 

 rell as of solvents). M. Alexeeff's data are not sufficient to permit 

 the construction of a curve representing a similar region mapped 

 t by the termination of isothermal lines. But it is obvious that it 



