108 
THEORY OP GALVANISM. 
Excitement of nication with tlie outside air, and has not a sensible agitation in i| 
tridiyl^aifd^*^ inclosed space. Thus, the difl'erence of the electric states, M 
phenomena of produced by the action of tlje column at its extremities, is { 
the electric 
eolunin. almost entirely preserved. Now, the great increase in the | 
difference between the positive and negative states at these extre- j 
mities, resulting only from mere preservation, manifests a much 
greater electromotion produced by the simple association of 
zinc and silver plates in pairs separated by paper, than appeared 
in the column as I had first constructed it. 
After this statement of the phenomena of the electric co- 
lumn, there rerriains very little more for me to add concerning 
the second object announced in the title of this paper, which 
is, to compare these phenomena with the theories of the 
excitement of galvanic electricity collected by Dr. William 
Henry in his paper published in your number for August. 
The electfomotion in the galvanic pile is a common object 
in all these theories j and in all of them it is attributed, though 
in various manners, to chemical agency. _ Mr. Henry is very 
fair in his judgment of the theories which he successively de- 
tails j stating the objections which he finds himself against 
them, though setting out from the principles of their respective 
abthors. Had he, therefore, been informed of the phenomena 
of Mr. Singer’s column, which produces more electromotion 
than any galvanic pile which has ever existed, without any 
appearance of chemical agency, either between its extremities, 
or in itself, he would have found the solution of all the diffi- 
culties which he has himself pointed out in these theories, 
being thus informed, that no connection exists between the 
electromotion and chemical effects in the galvanic pile, j 
This interesting question. Sir, will surely be brought to an i 
' issue, if you admit this paper in your valuable Journal ; for I g 
cannot doubt, that those experimental philosophers who shall I 
not be satisfied with my arguments on this very interesting | 
point of natural philosophy, will undertake experiments to I 
discover my errors J andj on whatever side the decision shall I 
be final, it will be a fixed step in that science, which will give I 
me 
