ANALYSIS OF THE GALVANIC PILE. 129 



Third Bisection of the Pile. 



Exp. 13. Cessation of every effect with this dissection, 

 as in Exp. 6. 



Such are the leading experiments with respect to the Exp. 13. 

 mode of action of the pile ; hut before I come to their gene- 

 ral conclusions, I must return to the particular circum- Circumstance 



stance belonging; to Exp. 5 and 12, namely, that at the apparently fa- 



ft • ' * . vourable to 



game time that no chemical effects were produced in the wa- Mr. Davy's 



ter of the glass tubes, no residua of electric signs remained theory 

 perceptible in the points a, e, b of the circuit. This cir- 

 cumstance might appear favourable to Mr. Davy's idea on 

 the mode of action of the pile, thus expressed at p. 45 of his 

 paper above mentioned. 



" In the voltaic pile of zinc, copper, and a solution of 

 '< muriate of soda, in what is called its condition of electric 

 " tension, the communicating plates of copper and zinc are 

 " in opposite electrical states. And with respect to elec- 

 * e tricities of such very low intensities, water is an insulating 

 " body : every copper plate consequently produces, by 

 " induction, an increase of positive electricity upon the 

 ■• opposite zinc plate; and every zinc plate an increase of 

 *' negative electricity on the opposite copper plate; and the 

 " intensity increases with the number, and the quantity 

 " with the extent of the series. When a communication is 

 ** made between the two extremities, the opposite electri- 

 " cities tend to annihilate each other ; and if the fluid me- 

 " dium could be a substance incapable of decomposition, 

 p the equilibrium, there is every reason to believe, would 

 ** be restored, and the motion of electricity cease." 



1 shall not consider for the present that system in itself, differently ex* 

 but only on account of the connexion which it may appear plained. 

 to have with the above 5 and 12 experiments. For as at 

 the same time that, in these experiments, the process called 

 decomposition of water had ceased in the glass tubes, no 

 residua of the electric fluid were perceptible by the conden- 

 ser in any part of the circuit', it might be supposed, ac- 

 cording to Mr. Davy's idea, that the motion of the electric 

 fluid had really ceased. But the following experiments 

 will show, that the cause of no residua appearing in the 



Vol. XXVI.— J ene, 1810. K. cage* 



