206 THE PHENOMENA OF MOTION 



all these manifestations of force ; it is merely the con- 

 ductor of force. 



We observe, further, in this wire, phenomena of at- 

 traction and repulsion, which we must ascribe to the 

 disturbance of the equilibrium in the electric or mag- 

 netic force ; and when this equilibrium is restored, the 

 restoration is accompanied by the development of light 

 and heat, its never-failing companions. 



All these remarkable phenomena are produced by 

 the chemical action which the zinc and the acid exert 

 on each other ; they are accompanied by a change in 

 form and structure, which both undergo. 



The acid loses its chemical character ; the zinc en- 

 ters into combination with it. The manifestations of 

 force produced in the wire are the immediate conse- 

 quence of the change in the properties of the acid and 

 the metal. 



One particle of acid after another loses its peculiar 

 chemical character ; and we perceive that in the same 

 proportion the wire acquires a chemical, mechanical, 

 galvanic, or magnetic force, whatever name be given to 

 it. According to the number of acid particles which 

 in a given time undergo this change, that is, according 

 to the surface of the zinc, the wire receives a greater 

 or less amount of these forces. 



The continuance of the current of force depends on 

 the duration of the chemical action ; and the duration 

 of the latter is most closely connected with the carry- 

 ing away, by conduction, of the force. 



