THEORY OF GALVANISM. 109 



of them, and is transferred to the conductor. From 

 the conductor it may be communicated to a variety 

 of other bodies that are placed within the sphere 

 of its influence ; but, in all these cases, it is re- 

 tained by them for a certain space of time only, 

 and is continually passing off, more or less rapidly , 

 to all the surrounding bodies. 



But besides this temporary transfer from one Electricity 

 body to another, without their undergoing any far- 

 ther alteration, they occasionally experience a more 

 permanent change in their electrical state, when, 

 in consequence of their acquiring different physical 

 and chemical properties, their capacity for electri- 

 city is entirely altered. When their capacity is 

 diminished, a more gradual, but more continued 

 discharge of the electric fluid takes place ; and in 

 this appears to consist the essential action of the 

 pile, as contrasted with that of the machine. In 

 the action of the machine, by which the electric 

 fluid is set at liberty, and transferred from one 

 body to another, no change appears to take place > ' 

 in the substances employed, except the alteration 

 in their respective quantities of electricity. Their 

 attraction for it is neither increased nor dimi- 

 nished ; and, consequently, they have a tendency, 

 the one to lose, and the other to acquire, the elec- 

 tricity which has been thus, as it were, forced into 

 the one, and out of the other. According to the 

 nature of the action by which the electricity is 

 evolved, whether the substances experience any 

 permanent change in their capacity, or whether 



