loU EULOGY ON ALEXANDER VOLTA. 



coutact aud the iuterpositiou between these same parts of a third sub- 

 stance. The fuudameutal principle of the Voltaic theory, far from being 

 shaken, only acquired a much greater generality. Metals no longer 

 formed an exclusive class. Analogy led to the fact that two dissimilar 

 substances, whatever their nature, give rise by mere contact to a 

 development o*f electricity. 



There was nothing henceforth serious in the attack of the galvanists. 

 Their experiments were no longer confined to very small animals. 

 They produced strange nervous movements in the nostrils, tongue, and 

 eyes of an ox killed for several days, thus strengthening more or less 

 the hopes of those to whom galvanism had seemed a means of resusci- 

 tating the dead; but they threw no new light on the theory. By 

 borrowing arguments, not from nature, but the grandeur of the effects, 

 the adepts of the Bolognese school strongly resembled that savant, 

 who, to prove that the atmosphere is not the cause of the rise of the 

 mercury in the barometer, conceived the idea of substituting a large 

 cylinder for the narrow tube of this instrument, aud then cited, as a 

 formidable difficulty, the exact number of quintals of liquid raised. 



Volta gave a death-blow to animal electricity. His conceptions were 

 constantly verified by experiments, but these were not well understood, 

 and by means of them it was hoped to undermine him. His conclusions 

 had not, aud we may add that they could not have, as yet the entire and 

 unprejudiced approval of physicists. The contact of two metals, of two 

 dissimilar substances, gave rise to a certain agent which, like electricity, 

 produced spasmodic movements. About this fact there was no doubt ; 

 but was the agent in question really electrical 1 Were the proofs 

 given sufficiently satisfactory ? 



When two dissimilar metals are placed on the tongue in a certain 

 order, at the moment of coutact an acid taste is produced. If the 

 order of these metals be reversed, the taste becomes alkaline. Xow, 

 by simply applying the tongue to the conductor of an ordinary electri- 

 cal machine, the taste is acid or alkaline, as the conductor is charged 

 plus or minus. In this case, the phenomenon is undoubtedly due to 

 electricity. "Is it not natural," said Volta, "to infer an identity of 

 causes from a resemblance of the effects ; to assimilate the first experi- 

 ment with the second ; to find but one diflerence between them, namely, 

 the mode of producing the principle which excites the organ of taste?" 

 No one questioned the importance of this comparison. Volta's pene- 

 trating genius saw in it the basis of a thorough conviction. Most physi- 

 cists required more explicit proofs. These proofs, these incontestable 

 demonstrations, before which all opposition must vanish, Volta found 

 in a capital experiment which can be explained in a few words. 



Two polished disks of copper and zinc, with insulated handles, are 

 brought exactly in contact, with nothing intervening ; by means of 

 these same handles, the disks are then suddenly separated ; aud, finally, 

 each in turn is presented to the ordinary condenser, armed with an elec- 



