LECT. X. ITS ORIGIN. 211 



current circulates in the muscle, from the tendinous ex- 

 tremity to the muscular surface. 



In arranging this pile, we must carefully avoid exposing 

 the internal part of the muscle, and we must especially 

 place one element in contact with another, in such a man- 

 ner that the tendinous extremity touches the surface of the 

 muscle, and never its interior : indeed, the latter ought to 

 be as far as possible from the tendon. Without this pre- 

 caution there will be, in the circuit, the muscular current 

 which, being directed from the interior to the surface, would 

 have a direction precisely the reverse of that of the proper 

 current. The existence of the proper current of the frog, 

 in all animals in the way described, was found at the same 

 time by M. Cima, by M. Boy-Raymond, at Berlin, and by 

 myself. 



Having thus ascertained the conditions on which the 

 proper current depends, I think that I may generalize its 

 origin, and connect it with the muscular current. This 

 community of origin is principally demonstrated by the 

 identity of action which the different circumstances that 

 modify the organism and life of animals, exercise upon the 

 muscular current. In fact, whether the current be muscular 

 or proper, the action exercised on it by heat, narcotics, 

 sulphuretted hydrogen, and the degree of integrity of the 

 nervous system is the same. 



Anatomists, and especially Bowman, have lately demon- 

 strated, that the elementary muscular fibres are immediately 

 continuous with the tendinous fibres, and that the sarco* 

 lemma which invests the muscle, ceases abruptly where the 

 tendon begins. We may, then, with some probability, con- 

 sider the tendon as being in the same electric condition as 

 the interior of the muscle; and, therefore, when we form, 

 by means of a good conductor, a circuit or communication 

 between the tendon and the sarcolemma, we put into cir- 

 culation a portion of the muscular current 



