70 Biographical Notice of Alexander Volta. 



endeavored to explain it by a fluid sui generis, which they 

 called animal electricity, and which they supposed to be 

 put inaction in the experiment just named. A^olta's opin- 

 ion was widely different from that of the authors of this hy- 

 pothesis. He advanced the idea, that this fluid was nothing 

 more than common electricity developed by the contact of 

 two metals, and that the frog only acted the part of a con- 

 ductor and electroscope. This simple and natural explana- 

 tion met with many objections. Galvani and the other phi- 

 losophers alleged that it was not necessary to make use of two 

 different metals, and that the contact of two similar metals, 

 or even that of the muscles and nerves of the frog, was suf- 

 ficent to produce the shock, which, it is true was much 

 weaker. Volta replied that these results preceded from this, 

 that the metals were not perfectly the same, and that the 

 nerves and muscles might also, as heterogeneous substances, 

 produce electricity by their contact. Volta must be admired 

 for the indefatigable perseverance with which he endeavor- 

 ed to prove the truth of his explanation, and of the general 

 principle, that two heterogeneous bodies in contact are in two 

 different electrical states; he was not discouraged either by 

 difficulty of execution, or by the ceaseless attacks which were 

 directed against him by philosophers rendered jealous by not 

 having been able to discover a truth which was directly before 

 their eyes. He succeeded in producing electricity simply by 

 the contact of two metals, without the aid of a frog ; he 

 shewed by means of his condenser, that the agent produced 

 in this manner, possessed all the properties of common elec- 

 tricity ; he replied victoriously to his adversaries, who dared 

 no longer to oppose him, in making to the scientific world the 

 invaluable gift of the apparatus known by the name of the 

 voltaic pile. 



Volta was led to the construction of his pile by the dis- 

 tinction which he established, between electro-motive bo- 

 dies, such as the metals, and bodies, which are not electro- 

 motive, or only in a very low degree, but which serve only 

 as conductors, such as fluids. 



Having discovered that the contact of two different met- 

 als, called a pair or a voltaic element, produces a certain quan- 

 tity of electricity, he was enabled to increase this quantity, 

 by the union of several of these elements to one another, 

 by means of one of those conductors such as water hold- 

 ing in solution a salt or an acid. 



