148 THEORY OF GALVANISM. 



states may exist while they actually remain in con- 

 tact. He speaks of the pile under the title of an 

 electro-motive apparatus, which derives its power 

 entirely from the electric action of the two metals; 

 the interposed fluid serving merely as a conduct- 

 ing body, and its chemical action being only 

 incidental. In describing the effect of this instru- 

 ment, the oxygen is stated to proceed from the 

 vitreous and the hydrogen from the resinous pole ; 

 and he proceeds entirely upon the supposition that 

 the effect depends upon the action of the metals 

 on each other, and not upon that of the fluid 

 upon either of the metals. His arguments against 

 the chemical action of the pile may be considered 

 as summed up in the following paragraph, which 

 I give the reader in the author's own words. 

 " The connexion which we observe between the 

 oxidation and the electrical state has induced some 

 distinguished philosophers to suppose that the 

 second was an effect of the first ; and the increase 

 of action which is produced by chemical decom- 

 positions have furnished them with very powerful 

 arguments in favour of this opinion. But it 

 appears to me that the experiments of Volta on 

 the development of electricity which takes 

 place from the contact of insulated metals, can 

 leave no doubt as to the principle; and the 

 less so, because if we join to this the phenomena 

 of the transfer, there is no circumstance in the ex- 

 periments which is not perfectly explained by dif- 

 ferences in the conducting power. If the chemical 



