THEORY OF GALVANISM. 



the change which can be produced upon the ori- 

 ginal hypothesis of Volta ; the only fundamental 

 positions of which are, that the electrical equili- 

 brium of the two metals is destroyed by placing 

 them in contact, and that the water, when inter- 

 posed between the plates, conducts the electricity 

 so as to destroy the equilibrium. In this state of 

 things the apparatus will be nearly inert, at least 

 it will have no more power than that produced by 

 a single pair of plates ; for all the intermediate 

 ones, being in contact with water, will be brought 

 to a state of equilibrium. 



Dr. Wollaston, as I have already remarked, was chemical 

 the first who decidedly pronounced the chemical yp< 

 action of the pile to be the primary cause of its 

 effects ; but in establishing this point, he did not 

 proceed to explain the nature of the operation, or 

 show what was the train of events which contri- 

 buted to the final result. This was attempted by cuthber<- 

 Mr. Cuthbertson, who, in the essay to which I s n o' n s . pl ~ 

 referred above, after pointing out the inaccuracy of 

 the experiments that were brought forward by 

 Volta in favour of the electric hypothesis, offers 

 some observations in support of the contrary opi- 

 nion. He conceives that the chemical action of 

 the interposed fluid upon the zinc alters the elec- 

 tric properties of the metal, and disposes it to part 

 with electricity ; that this evolved electricity can- 

 not enter into the remainder of the zinc which has 

 not been acted upon, because it retains its former 

 electric state, but that it is " propelled forwards 



6 



