430 Dr. Wollaston’s Experiments on 
upon being burnished, was evidently copper ; but the opposite 
wire had no such coating. 
Upon reversing the direction of the current of electricity, the 
order of the phenomena was of course reversed ; the copper 
being shortly redissolved by assistance of the oxidating power 
of positive electricity, and a similar precipitate formed on the 
opposite wire. 
Exper. 5. A similar experiment made with gold wires of 
an inch diameter, in a solution of corrosive sublimate, had the 
same success. 
The chemical agency, therefore, of common electricity, is thus 
proved to be the same with the power excited by chemical 
means; but, since a difference has been observed in the compa- 
rative facility with which the pile of Volta decomposes water, 
and produces other effects of oxidation and de-oxidation of bodies 
exposed to its action, I have been at some pains to remove this 
difficulty, and can at least produce a very close imitation of the 
Galvanic phenomena, by common electricity. 
It has been thought necessary to employ powerful machines, 
and large Leyden jars, for the decomposition of water; but, 
when I considered that the decomposition must depend on duly 
proportioning the strength of the charge of electricity to the 
quantity of water, and that the quantity exposed to its action at 
the surface of communication depends on the extent of that 
surface, I hoped that, by reducing the surface of communica- 
tion, the decomposition of water might be effected by smaller 
machines, and with less powerful excitation, than have hitherto 
been used for that purpose ; and, in this hope, I have not been 
disappointed. 
Exper. 6 . Having procured a small wire of fine gold, and 
