1887.] 
Mr W. Durham on Laws of Solution. 
381 
5. On the Minute Structure of the Eye in certain Cymo- 
thoiche. By Frank E. Beddard, Esq., M.A., E.Z.S. 
8. On the Mean Height of the Land of the Globe. By 
John Murray, Esq. 
7. The Ohsetopoda Sedentaria of the Firth of Forth. By 
J. T. Cunningham, Esq., B.A. 
Monday, 1 8th Jidy 1887. 
Sheriff EOBBES IEVINE, Vice-President, in the Chair. 
The Chairman intimated the foundation by Dr Gunning of the 
Victoria Jubilee Prize , and the conditions of award which have 
been approved by the Donor, and added that the Prize of One 
Hundred Guineas from this source had been this year awarded by 
the Council to Sir William Thomson, for a remarkable series of 
papers on Hydrokinetics, especially of Waves and Vortices, forming 
some of the most valuable that have been communicated to the 
Society. 
The following Communications were read : — 
1. Laws of Solution. Part II. By V . Durham, Esq. 
From the note in my former paper on the above subject it is 
easy to deduce the following formula, which expresses the relations 
between the heats of chemical combination and the heats of solu- 
tion : — 
Heat of Combination. Heat of Combination. 
f [M,X 2 ] l , 
: [M,0,Aq]| 
l - [H 2 X 2 , Aq] / 1 
l - [H 2 0] / 
Heat of Neutrality. Heat of Solution. 
[MOAq,H 2 X 2 Aq] ± {MX 2 ,Aq + }. 
This formula is perfectly general for chlorides, bromides, iodides, 
sulphates, and nitrates, and whether the oxides and salts are soluble 
nr insoluble. It shows that the heats of solution pass from negative 
