2O2 ELECTRIC EXCITATION CAUSES 



such cells in each prism, a pile would be pro- 

 duced, at the two extremes of which the greatest 

 differences in the electric conditions would be 

 found ; and the intensity of the discharge would 

 thus depend upon the number of elements in the 

 pile ; while its quantity would be proportional to 

 the multiplication of the separate prisms. 



" This is precisely what holds good in Nature ; 

 for the electric discharge of the gymnotus is far 

 more intense than that of the torpedo, as might 

 be expected from the multiplication of its cells ; 

 so that, according to Professor Faraday, 'a single 

 medium discharge from this animal gives a shock 

 equal to that of a battery of fifteen Leyden jars, 

 containing 3500 square inches, charged to its 

 highest degree.' Further evidence, that the force 

 which enables electric fishes to give sensible man- 

 ifestations of electricity is the same as that which 

 excites contraction when transmitted to the mus- 

 cles, is derived from the close conformity between 

 the conditions under which the two phenomena 

 respectively occur. The connection of the organs, 

 specially appropriated to each of these actions, 

 with the nervous system, the dependence of their 

 functions upon the integrity of this connection, 

 and upon the will of the animal, the influence 

 of stimulation applied to the nervous centres or 

 trunks, the effect of ligature or section of the 

 nerve, and the results of poisonous agents, are 

 all so remarkably analogous in the two cases, 



