[ 440 ] 



LXIV. Further Researches on Electro-Physiology. 

 By M. Ch. Matteucci*. 



I HOPE that the Academy, which has always been pleased 

 to encourage me in my researches upon electro-physio- 

 logy, will permit me to communicate some new investigations 

 upon this subject. I cannot commence the exposition of these 

 researches without very briefly recapitulating the four principal 

 points from which I started, and which, to a certain extent, 

 form a summary of the whole of my former labours. 



1. In each cell of the electric organ of fishes, the two elec- 

 tricities become separated under the influence of the nervous 

 action propagated from the brain towards the extremities of 

 the nerves. A relation exists between the direction and the 

 intensity of the nervous current, and the position and the 

 quantity of the two electricities developed in the cell. In acr 

 cordance with this relation which has been established expe- 

 rimentally, if, as was done by Ampere in the case of electro- 

 magnetic action, we represent the nervous current by a man 

 lying extended upon the nerve, and with his face turned 

 towards the caudal extremity of the Torpedo or the dorsal 

 surface of the Gymnotus, the positive electricity of the cell 

 always exists on the left of the man: since each cell of the 

 organ forms a temporary electi'ic apparatus, this explains the 

 position of the poles at the extremities of the prisms, and the 

 intensity of the discharge being proportional to the length of 

 the prisms, as established by experiment. 



2. It has been shown by experiment, that the greatest ana- 

 logy exists between the discharge of electric fishes and mus- 

 cular contraction. There is no circumstance which modifies 

 one of these phaenomena which does not act equally upon the 

 other. 



3. The contraction of a muscle developes in a nerve which 

 is in contact with this muscle, the cause by which the nerve 

 excites contractions in the muscles through which it ramifies. 

 Although experiment has not yet enabled us to decide whether 

 this phaenomenon is an instance of nervous induction, or a 

 proof of an electric discharge developed by muscular contrac- 

 tion, we are led by all analogy to admit the second hypothesis. 



4. The electric current modifies the excitability of the nerve 

 according to its direction. The electric current, when pro- 

 pagated in the direction of the ramification of the nerve, de- 

 stroys its excitability ; when propagated in a contrary direc- 

 tion to the ramification, it augments the excitability of the 

 nerve. The phaenomena brought into play by the cessation 



* From the Comptes Rendus for April 30, 1849. 



