LECT. XIV. XV. NOT ELECTRICITY. 261 



it a soft iron cylinder. Through the nerve, thus prepared, 

 I passed the electric current but never observed constant 

 signs of the induced current in the spiral, which would 

 certainly have occurred if the current had traversed this 

 species of spiral which, it is presumed, is formed by the 

 nervous ramifications distributed over the muscles. 



Let us conclude, then, that the electric current does not 

 naturally exist in the nerves of a living animal. The laws 

 of its propagation require conditions which are not found 

 fulfilled in the nervous system ; the propagation of its force 

 is interrupted by causes which could not produce a similar 

 effect upon the electric current. 



Relations between the Nervous Force and Electricity. 

 This unknown force of the nervous system is, therefore, 

 not electricity, and still less is it the electric current. But 

 what connexion exists between it and electricity, or the 

 electrical current ? 



In order to reply to these questions, I will here sum up, 

 in a few words, the only positive result that my lengthened 

 investigations of electro-physiological phenomena of ani- 

 mals have permitted me to deduce. 



There exists, between electricity and the nervous force, 

 an analogy which, if it does not possess the same degree 

 of evidence, is, however, of the same kind as those ana- 

 logies which we know to exist between caloric, light, and 

 electricity. We have seen, when speaking of the pheno- 

 mena presented by electrical fishes, that the faculty which 

 they possess of producing electricity is obedient to the 

 nervous system. There is, then, in these animals a pecu- 

 liar organic structure, such an arrangement of parts that, 

 by an act of the nervous force they can develop the elec- 

 trical fluid. You remember the identity of causes and cir- 

 cumstances which excite and modify muscular contractions, 

 and, this function is proper to these animals. You have 



