116 ANNUAL OF SCIENTIFIC DISCOVERY. 



FURTHER RESEARCHES ON ELECTRO-PHYSIOLOGY. 



WE translate from the Comptes Rendus the substance of a paper by 

 M. Matteucci, on electro-physiology. He commences by recapitulating 

 the four principal points from which he started, and which, in some de- 

 gree, form a summary of his former labors. " 1. In each cell of the electric 

 organ of fishes, the two electricities become separated under the influ- 

 ence of the nervous activity propagated from the brain towards the ex- 

 tremities 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. 2. It has been shown by 

 experiment that the greatest analogy exists between the discharge of 

 electric fishes and muscular contraction! There is no circumstance 

 which modifies one of these phenomena, that does not equally act upon 

 the other. 3. The contraction of a muscle develops in a nerve which is 

 in contact with it the cause by which the nerve excites contractions in 

 the nerves throughout which it ramifies. Analogy leads us to consider 

 this phenomenon a proof of an electric discharge developed by muscular 

 contraction, though this has not been decided by experiment. 4. The 

 electric current modifies the excitability of the nerve according to its 

 direction : when propagated in the direction of. the ramification of the 

 nerve, it destroys its excitability ; but when propagated in a contrary 

 direction, it augments it. I shall now confine myself to communicating 

 a result which I regard as fundamental to the theory of electro-physio- 

 logical phenomena. By a *simple experiment, I have shown that an 

 electric current which traverses a muscular mass in the direction of its 

 fibres, develops in these filaments a nervous current, which direction 

 varies according to that of an electric current, relatively to the ramifica- 

 tion of the nerve. This is the reaction of electricity upon the nervous 

 force. In discovering a new and very intimate analogy between the 

 electric discharges of fishes and muscular contraction, I have shown 

 that the nervous current develops the two electricities in a determinate 

 direction, according to its own direction. In a muscular mass, the two 

 electric states, diffused through the elements of its fibres, produce a 

 current, whose direction varying with that of the electric current is es- 

 tablished, like the direction of the discharge in the torpedo fish, by that 

 of the nervous current which excites it. This foundation of the electro- 

 physiological phenomena I have taken great pains to establish. What- 

 ever may be the nature of the nervous force, it is a fact that this force 

 is propagated in the nerves, sometimes from the brain to the extremities, 

 and sometimes in a contrary direction. It is probable, that when the 

 muscles are contracted by our will, a nervous current is propagated in 

 the direction of the ramification of the nerve ; but on the other hand, 

 the nervous current follows an opposite direction when sensation is ex- 

 perienced by the stimulation of the extremities of the nerve. 



" I have shown n my former researches, by experiments, the great 

 difference between the nervous and the muscular substance, as re- 

 gards the conduction of the electric current. These experiments I 



