Excitement of Galvanic Electricity. 295 
It is to this transference of electricity, that 
Volta ascribes the whole of the phenomena, 
exhibited by Galvanic combinations. Ac- 
cording to his view, the interposed fluids act 
entirely by their power of conducting electri- 
city, and not at all by any chemical property. 
The effect of a series of Galvanic plates, or 
of a Galvanic pile, he believes to be nothing 
more than the sum total of the effects of seve- 
ral similar couples or pairs. Why the evolved 
electricity is determined to one end of the 
series, and exists there in its greatest force, I 
shall attempt to explain by the following 
illustrations, : 
If a plate of zinc be brought into contact, 
on both sides, with a plate of copper, it may 
be considered as acted upon, in opposite 
directions, by equal forces, which destroy each 
other. No alteration, therefore, takes place 
in its state of electricity ; nor does any change 
happen, even when we substitute, for one of 
the copper plates, a third metal; on account 
of the trifling difference between the electro- 
motive powers of bodies of this class. But 
liquids, possessing this power in only a very 
small degree, may be brought into contact - 
with one of the zinc surfaces, without impair- 
img the electromotive effect ; and acting merely 
as conductors, they convey the excited elsctri- 
