﻿JflDEXED 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[SIXTH SERIES.] 



JULY 1906. 



I. The Molecular Constitution of Aqueous Solutions. 

 By William Sutherland*. 



IN the recent study of aqueous solutions most attention has 

 been given to the solute, little being devoted to the 

 equally important changes in the solvent. From the data of 

 "The 'Molecular Constitution of Water" (Phil. Mag. [5] 

 vol. 1. 1900) it is possible to calculate the effect of solute on 

 solvent, and so to arrive at a tolerably complete conception of 

 the molecular constitution of aqueous solutions. In that 

 paper, it was shown by the development of ideas of Rbntgen 

 and others that water consists of a mixture of trihydrol (H 2 0) 3 

 and dihydrol (H 2 0) 2 , ice being pure trihydrol, and water at 

 its critical temperature nearly pure dihydrol, while aqueous 

 vapour is hydrol, H 2 0. At about 15° C. water is one-third 

 trihydrol and two-thirds dihydrol, the percentages at other 

 temperatures being given in Table I. of that paper. Various 

 physical constants of both constituents are collected in 

 Table XIII. , supplying necessary data for the following 

 inquiry, in which it will be shown that a solute causes the 

 dissociation of trihydrol into dihydrol, whence the abnormal 

 behaviour of aqueous solutions. Electrolytic solutes will be 

 taken as the most general type, the results of which can be 

 applied to non-electrolytes by making the electrolytic disso- 

 ciation of these vanish. The laws of the dissociation of 

 trihydrol by solutes will be investigated by considering for 



* Communicated by the Author. 

 Phil. Mag. S. 6. Vol. 12. No. 67. July 1906. B 



