262 ANALYSIS OF THE GALVANIC PILE. 



Propagation of After having shown distinctly what are the electric effects 

 the effect. produced hy the conjunction of zinc and capper, and in 

 pile. what manner the condenser manifests these effects, I come 



to their propagation from each group along the pile, on 

 one side negative and on the other positive. The following 

 experiments will show the first steps, which will be easily 

 extended throngh the whole. 

 Exp. 33. Exp. 33. Upon a zinc disk, of the same size as the 



others, I fixed a piece of Dutch-gilt paper, the copper side 

 next to the zinc, and the paper outside, held by a little 

 paste all around. This association is to represent one group 

 of the pile, considered for the present only on the copper 

 side, with the paper, which, in the pile, separates it from 

 the next group on this side, and more directly from the zinc 

 plate of that group. Holding on my hand the zinc side of 

 the former group, I repeated on its paper, with the insu- 

 lated zinc disk, the alternate contacts with the condenser ; 

 and by 20 repetitions a sensible negative divergence was 

 produced in the electroscope of the latter. The same effect 

 takes place in the pile at the copper side of every group ; it 

 takes, through the paper, some electric Jiuid from the zinc 

 of the next, group; but as zinc must always possess more of 

 this jiuid than the copper with which it is connected, the 

 zinc of that next group takes more from its own associated 

 copper, which then, through the paper, takes more from 

 the zinc of the following group ; which effect goes on in- 

 creasing, up to the end of the pile on this side. I shall 

 only add to this experiment, that, as the property of a group 

 composed of zinc, copper, and paper on the latter, is to 

 have this side negative, whatever be the metal with which 

 the above alternate contacts are performed, they produce 

 the same negative effect on the condenser. 

 Condenser ^ n order to complete directly the first step here in view, 



does not direct- ty taking one group as an example, it would be desirable, 

 th^zf.'c' yields thtit h f P ldC,n o a piece of paper on the zinc side of this 

 electric fluid to group, in order to represent the separations of the groups in 

 the next group: the ^ ^ ^ direction, ft should manifest directly by the 



condenser, that zinc yields some electric fluid to the next 

 group; but I have not been able to obtain such a direct 

 proof, on account of a circumstance which I shall now in- 

 dicate, as peculiar to that quantity of electric flutf set in 



motion 



