300 The Rev. Dr. Rosinson on the Effect of Heat in lessening the 
If several cells be combined in a battery, it is also known that & and R are the 
sums of those quantities for each cell, even when the chemical actions in them are 
unequal, or in some of them antagonistic; the latter case belonging to the for- 
mula 
Ee 
ee ea 
e and y being the mtensity and resistance of the negative cell. Let us apply this 
to the common voltameter, containing water, acidulated with sulphuric acid to 
make it a better conductor, and provided with platinum electrodes. This cell, 
before it is made part of the circuit, is of course inert; but the current, decom- 
posing the water, coats the anode, or positive platinum, with a film of oxygen 
retained there, either as peroxide of hydrogen, or, as seems more probable, con- 
densed into the fluid state by the enormous force which capillary phenomena 
prove to exist at the surface of solids ;* the hydrogen being similarly attached to 
the cathodes. These, with the platinum, act against the current with the nega- 
tive intensity, o.p + h.p — h.o;f and unless its £ be considerable, arrest it; till 
they are weakened by the gradual solution of the condensed gases in the electro- 
lyte. But if the battery have sufficient power, the decomposition proceeds, till 
the capillary force of the electrode surfaces can no longer detain the accumulated 
gases, and theinexcess escapes, the peculiar charge of the electrodes being still 
maintained. ‘The continued evolution of the gases adds another negative, h.o ; 
and as p./ is most probably insensible, the expression of this force, which I call 
electrolytic intensity, becomes 
e=op —2ho. (c) 
* Charcoal absorbs in this way 9.25 times its bulk of oxygen. Supposing the carbon to be as 
dense as diamond, it would occupy about one-third of the space; were the condensed gas to fill all 
the remainder, its pressure must be at least fifteen atmospheres, but as it is probably in a film of 
evanescent thickness, the force is very much greater than even this. 
+ This is probably the intensity of the gas battery, but I have not access to one of these 
curious instruments. The quantity 0.p — h.o can be obtained by measuring the intensities of a 
combination of zine and platinum, excited with dilute sulphuric acid, and then with that and sul- 
phate of platinum, being their difference. Ifthe cathode be a metal easily oxidated, its affinity is 
substituted for that of the condensed hydrogen, and the expression is, say for zinc, 
e’ =0.p — ho — 20, 
by means of which a wide range of them may be determined. 
