OR VOLTAIC ELECTRICITY. 389 



gas, and the detonation of gunpowder, are more 

 like an electric explosion than any thing else. 



The ordinary process of combustion by which 

 heat is evolved, consists in the combination of 

 oxygen with other elements. The galvanic fluid 

 is decomposed by the same process : while it 

 would be contrary to all the rules of a sound 

 induction, to suppose that two or more distinct 

 ethereal agents could be disengaged from the 

 same elements. If we reject this simple mode 

 of reasoning, we shall be compelled to admit 

 the existence of as many electricities as there 

 are modes of separating it from ponderable 

 matter, which would be absurd. It is far more 

 consistent with facts and the harmonious sim- 

 plicity of nature to suppose that one agent pro- 

 duces all the diversified powers and activities of 

 matter that it exhibits different properties and 

 appearances under different circumstances, ac- 

 cording to its diffusion, concentration, compres- 

 sion, &c. and to the mode of its combination 

 with different substances, in a solid, liquid gas- 

 eous, or imponderable state, as in the matter of 

 light. 



We have already seen, that a certain tempe- 

 rature is indispensable to combustion, fermenta- 

 tion, putrefaction, and to every process of oxida- 

 tion, however slow, as the rusting of metals, 

 that when atmospheric oxygen is thus made 

 to combine with metals, its volume is dimi- 



