rUESENT STATE OF ORGANIC ELECTllICITY. 327 



muscular substance clurinf; its life, and in the intervals of 

 contraction, is in a state of electric tension ; and that there 

 are in it an infinite number of electromotor centres in connec- 

 tion with closed circuits, according to the laws alreaily stateil ; 

 and AvJiicli must be infinitely stronger than those derived 

 currents which are i>rocured from a muscle, or a portion of it, 

 by means of the galvanometer. 



Du I'xns la'vmond having observed that the cun-ent de- 

 rived from a longitudinal section and from a natural transccrsc 

 section was generally weaker than that from an artificial trans- 

 verse section, and that it was even occasionally not obtainable 

 "when the electric tension of the muscle was much diminished 

 by cold, found, on further investigation, that it was necessary 

 to admit the existence of a layer of pecidiar electromotor 

 elements at the ends of the muscular fibres in contact with 

 the tendon. He denominates this the pardcdronomic layer, 

 as it produces a current opposed to the general nmscular 

 current, and must therefore present its positive elements 

 towards the tendon. For the puqiose of including this layer 

 in his general theory, he modifies his conception of the elec- 

 tromotor molecules, and illustrates the entire action by a cor- 

 responding change in his model. Instead of the molecules 

 being, as he had denominated them, j)^'i'^polar — possessing an 

 equatorial positive and two polar negative zones, he substi- 

 tutes for each of such molecules a pair of dipolar molecules 

 with their positive poles in contact, and their negative directed 

 away from one another. If, now, i\\Q parcledronmnic layer be 

 conceived as formed of one set only of such dipolar molecules, 

 they must necessarily have their positive poles next the ten- 

 dinous surface. 



This hj'pothesis not only satisfies the general law of the 

 muscular current, but also aftbrds a reason for the count<»ract- 

 ing inlluence of the natuiid transverse section, and the facility 



