HISTORY OF GALVANISM. 81 



effect, and will yet exhibit a higher electrical 

 tension. The power of the apparatus was found 

 to be nearly in proportion to the strength of the 

 acid employed ; and some comparative experiments 

 were instituted, for the purpose of comparing the 

 effects of acids, alkalies, and neutral salts. The 

 test which they employed to judge of the quantity 

 of effect produced by the pile, was the amount of 

 gas evolved from a fluid, subjected to the action 

 of the wires connected with its two extremities : 

 this they conceived was a more exact measure 

 of its energy than the different lengths of wire 

 which it was capable of consuming. The general 

 conclusion which they formed respecting the action 

 of the pile was, that its chemical energy depends 

 upon its tension, upon the conducting power of 

 the fluids with which it is charged, and upon the 

 facility of their decomposition. 



When they employed a very powerful battery, shock pro- 

 it was observed that considerable shocks were ^rge bat-* 

 given by it to an individual ; but that in a chain of tery ' 

 four or five persons, it was not felt in the centre ; 

 and in the extremities of the chain, that part of 

 the body received the greatest impression which 

 was nearest to the apparatus. This fact is sup- 

 posed to prove, that the electric fluid Cannot cir- 

 culate through the whole circuit, according to the 

 Franklinean hypothesis. When the battery is put 

 into strong action, its chemical effect, i. e. its 

 power of decomposing water, soon declines, or al- 



