84 HISTORY OF GALVANISM. 



Volta more fully still established his claim as 

 the main originator of this science by his next step. 

 When some of those who repeated the experiments 

 of Galvani had expressed a wish that there was 

 some method of multiplying the effect of this elec- 

 tricity, such as the Leyden phial supplies for com- 

 mon electricity, they probably thought their wishes 

 far from a realization. But the voltaic pile, which 

 Volta described in the Philosophical Transactions 

 for 1800, completely satisfies this aspiration ; and 

 was, in fact, a more important step in the history 

 of electricity than the Leyden jar had been. It 

 has since undergone various modifications, of which 

 the most important was that introduced by Cruik- 

 shanks, who 4 substituted a trough for a pile. But 

 in all cases the principle of the instrument was the 

 same ; a continued repetition of the triple combi- 

 nation of two metals and a fluid in contact, so as 

 to form a circuit which returns into itself. 



Such an instrument is capable of causing effects 

 of great intensity ; as seen both in the production 

 of light and heat, and in chemical changes. But 

 the discovery with which we are here concerned^ 

 is not the details and consequences of the effects, 

 (which belong to chemistry,) but the analysis of 

 the conditions under which such effects take place ; 

 and this we may consider as completed by Volta 

 at the epoch of which we speak. 



4 Fischer, viii. p. 683. 



