of Electrolyte on the Area of Electrification. 
93 
As already mentioned, the same strength of current flowed 
for equal times in the several experiments. It may therefore, 
I think, be assumed that the same quantity of electrification 
was set up on the analyzers, and, further, that the differences 
in the magnitude of the electrifications were determined by 
an influence or influences other than that of the quantity of 
electricity which flowed into the electrolyte. The resistance of 
a solution of copper sulphate increases, as is well known, 
with its dilution; and as the current was constant throughout, 
the electromotive force of the molecules of the several solu- 
tions necessarily increased in the same proportion as their 
resistances. The variations in the electromotive force must 
therefore again be regarded as the chief cause of the differ- 
ences in the magnitude of the electrifications, and consequently 
also of the intermedial spaces. It is certain that the electro- 
lytic radicals of sulphate of copper were separated on the 
analyzers in each of the experiments; but it by no means 
follows that the molecular decompositions were identical in 
each case; for it is known that the molecular constitution of 
salts in solution varies within certain limits with variations in 
the proportion of water. The relation already shown to obtain 
between the intermedial space and the electromotive force of 
similarly constituted molecules would lead to the conclusion 
that the intermedial spaces in this series of experiments would 
be inversely proportional to the resistances of the solutions, 
supposing that their molecular constitutions were similar. I 
have not the resistances for the exact strengths of the solu- 
tions ; but, taking approximations to these, I find the rela- 
tion referred to holds good in solutions varying from 6 to 
12 per cent, of copper sulphate — i. e. where the viscosity on 
the one hand, and the tendency to decomposition of the me- 
tallic salt on the other, perhaps differ so little as to be practi- 
cally inappreciable. The data &c. are set out in the annexed 
table : — 
Strength of copper- 
sulphate solution. 
Approximate 
resistance. 
Intermedial 
space. 
Eesistance X by 
intermedial space. 
6 per cent. 
8 
10 „ 
12 „ 
1-6 
1-3 
1-16 
1-04 
14 
16 
18-5 
22 
22-4 
20-8 
21-5 
22-8 
III. Influence of Temperature. — In this series of experiments 
the current was also constant, an ampere being again em- 
ployed. The strength of electrolyte was likewise constant, 
Phil. Mag. S. 5. Yol. 16. No. 98. August 1883, I 
