130 THEORY OF GALVANISM. 



consequently, produces by induction an increase of 

 positive electricity upon the opposite zinc plate, and 

 every zinc plate an increase of negative electri- 

 city on the opposite copper plate ; and the inten- 

 sity increases with the number, and the quantity 

 with the extent of the series. 



" When a communication is made between the 

 two extreme points, the opposite electricities tend 

 to annihilate each other ; and if the fluid medium 

 could be a substance incapable of decomposition, 

 the equilibrium, there is every reason to believe, 

 would be restored, and the motion of the electri- 

 city cease. But solution of muriate of soda being 

 composed of two series of elements, possessing op- 

 posite electrical energies, the oxygen and acid are 

 attracted by the zinc, and the hydrogen and alkali 

 by the copper. The balance of power is moment- 

 ary only/, for solution of zinc is formed, and the 

 hydrogen is disengaged. The negative energy of 

 the copper, and the positive energy of the zinc, are 

 consequently again exerted, enfeebled only by the 

 opposing energy of the soda in contact with the 

 copper; and the process of electro-motion conti- 

 nues as long as the chemical changes are capable 

 of being carried on."* 



This hypothesis agrees with that of Volta, in 

 ascribing the train of actions to the electric condi- 

 tion of the metals, yet it differs from it in many 



* Phil. Trans, for 1807, p. 45 : and Elements of Chemical 

 Philosophy, p. 168, et alibi. 



