248 INDUCTION OF 



wards the acid, resisted) constitutes, on the other, 

 the electric state. 



But the dilute acid being a compound body, there 

 exists in it, as before noted in the atmosphere, a 

 double current ; the oxygen moving towards, the 

 hydrogen away from, the point of chemical union. 

 The impulse of the hydrogen being imparted to the 

 particles of the platinum, and the motion resisted 

 in the latter by its cohesion of structure, there is 

 produced in it, as in the zinc plate, a state of electric 

 tension, but in a direction away from the point of 

 chemical action. These two tensions, therefore, are 

 really in one direction : unite them by a conductor 

 of that special form of motion, and what ensues but 

 a current, adding the momentum of the tension of 

 the platinum to that of the zinc, and facilitating by 

 so much the union of the zinc with the oxygen ? 



This view of the production of galvanism by 

 chemical action receives strong confirmation from 

 the state of tension generated in portions of gold by 

 hydrochloric and nitric acid, separated by a porous 

 partition. From what cause can such tension arise 

 but from the attraction of the chlorine resisted by 



