experienced by Animals* 287 



at the instant when the frog ceases to be thus placed in the 

 current. Volta and Fowler seem to have been the first to re- 

 mark this phenomenon, which was afterwards observed by Valli 

 and several members of the Academy of Sciences at Paris, and 

 by PfafF, the last of whom regarded it as a great objection to 

 Galvani's theory of animal electricity. Volta himself has 

 given an explanation of it ; but it would seem that this great 

 philosoper had only given it a transient consideration. He 

 speaks of it but incidentally in section 49 of his celebrated 

 memoir on the Identity of the Electric and Galvanic Fluids, and 

 in the following manner : — ' Such a contraction takes place on- 

 ly at the first irruption of the electric current, and sometimes 

 also at the moment when, by the rupture of the circuit, this 

 current is suddenly stopped, or rather driven back, as we may 

 suppose, by the obstacle which it suddenly encounters.' 



This explanation has been adopted by other natural philoso- 

 phers, as appears from section 80 of the excellent memoir pub- 

 lished in 1814, by M. Configliachi on the Identity of the Gal- 

 vanic and Electric Fluids. 



Being unable to comprehend how, in breaking the circuit, a 

 reflux of electricity could be produced, and finding the pheno- 

 mena to which it relates very remarkable, I studied the subject 

 experimentally, and began by an attentive examination of the 

 explanation of it given by Volta."" 



After detailing at great length a series of experiments on 

 frogs, by which he overturns the explanation given by Volta, 

 and establishes some new and important results, he concludes 

 with the following general remark and summary of his results. 



" Is there an animal electricity, as Galvani always maintain- 

 ed ? Or, what perhaps amounts to the same thing, is the elec- 

 tric fluid identical with the nervous fluid, as formerly conjec- 

 tured by other philosophers ? The preceding experiments put 

 us into a situation for determining this point. 



But, however this may be, the analysis which I have given 

 of the shock experienced by animals at the instant when they 

 cease to form part of the arc of communication between the 

 poles of a galvanic apparatus, afford me, I think, with cer- 

 tainty the following conclusions. 



