94 Mr. Tribe on the Influence of Strength 
a 5 per cent, solution of copper sulphate being employed. 
The temperatures are given in the annexed table of results: — 
Temperature. 
— electrifi- 
cation. 
Intermedial 
space. 
+ electrifi- 
cation. 
+ referred to 
— as unity. 
4° C 
19 
12 
36 
1-90 
8° 
17 
12 
38 
2-23 
16° 
16-5 
14-5 
36 
2-18 
24° 
16-5 
165 
34 
206 
32° 
17 
18 
32 
1-88 
40° 
19 
20 
28 
1-47 
56° 
21 
27 
19 
0-90 
72° 
22 
31 
14 
063 
88° 
25 
36 
6 
024 
As a rule, the boundaries of the electro-deposits are nearly 
or quite straight; the peroxide-of-silver boundaries, however, 
in the experiments above 32° C. were concave. Thinking 
that this concavity arose from the time being insufficient, I 
repeated some of the experiments, prolonging the time to 
20 minutes ; but the results were practically the same. The 
intermedial spaces in the higher-temperature experiments also 
exhibited signs of slight oxidation, which I am inclined to 
attribute to the disturbing influence of convection-currents. 
It will be observed that the intermedial space increased as 
the temperature increased. This, again, agrees with the prin- 
ciple connecting the area of the spaces with electromotive 
force ; for as the temperature increased, of course the resist- 
ance of the solution decreased ; the electromotive force of the 
molecules necessarily also decreased ; and the magnitude of the 
intermedial spaces increased, in accordance with the principle 
referred to. I have not the resistances of the solutions at the 
temperatures of my experiments, and cannot, therefore, institute 
a numerical comparison. 
The very small + electrifications at the high temperatures 
is very noticeable ; and I have thought tnat this may be not 
unconnected with differences in the action of heat itself on the 
opposite electricities. 
It will be noticed that one feature common to the experi- 
ments described is the inequality in the magnitude of the elec- 
trifications of opposite sign on the several analyzing plates. 
This fact naturally attracted my attention some years ago 
(Proc. Roy. Soc. no. 181, 1877); and the work of this paper 
was undertaken mainly in the hope of throwing light on the 
subject. I cannot say it has brought about the desired result. 
It has, however, cleared away one or two speculations, sug- 
gested the direction of further inquiry, and shown, among 
