214 HISTORY OF ELECTRICITY. 



Thus our conclusion with regard to this subject is, that if we wish 



O v 



to form a stable physical theory of electricity, we must take into 

 account not only the laws of statical electricity, which we have been 

 chiefly considering, but the laws of other kinds of agency, different 

 from the electric, yet connected with it. For the electricity -of which 

 we have hitherto spoken, and which is commonly excited by friction, 

 is identical with galvanic action, which is a result of chemical combi- 

 nations, and belongs to chemical philosophy. The connexion of these 

 different kinds of electricity with one another leads us into a new- 

 domain ; but we must, in the first place, consider their mechanical 

 laws. "VYe now proceed to another branch of the same subject, Mag- 

 netism. 



Theory than I have done here. This difference is principally due to a consr 

 deration of the present aspect of the Theory of Heat. 



