326 PRESENT STATE OF ORGANIC ELECTRICITY. 



of rabbits and frogs, but they are essentially the same in man, 

 in representatives of the four vertebrate classes, and in molluscs, 

 crustaceans, and annelids. 



The electromotor power, which is exhibited in the muscular 

 current, does not depend upon the areolar texture, the tendons 

 or vessels, etc., of the mass ; or on the contact of dissimilar 

 textures with the muscular fibre ; for the power is exhibited 

 when the smallest manageable portion, or even a single primary 

 fasciculus, is employed. The power evidently resides in the 

 ultimate fibre. 



Du Bois Eeymond has investigated the arrangement of the 

 electromotor elements on which this power depends. After 

 various experiments, he succeeded in constructing a model 

 consisting of a solid copper cylinder, with its cylindrical sur- 

 face coated with zinc, and suspended in or surrounded by an 

 electrolytic liquid, which fulfilled by means of the galvanometer 

 all the conditions of the current as derived from the natural 

 sections of an entire muscle. He arranged another model, 

 consisting of a number of similar but smaller cylinders, set in 

 longitudinal series, so that the positive or zinc elements were 

 directed laterally, and the copper or negative in the longitudinal 

 direction. A combination of this kind, immersed in a fluid, 

 exhibited by means of the galvanometer not only the currents 

 of the natural section of an entire muscle, but also the currents 

 of its artificial sections. Du Bois Eeymond, therefore, con- 

 cluded, that the conditions of the muscular current are fulfilled 

 by assuming in the muscular mass the existence of electromotor 

 centres, each of which may be conceived to be a molecule 

 consisting of an equatorial positive zone and two polar negative 

 zones, these molecules being arranged linearly, so that the 

 polar zones are in the direction of the muscular fibre. 



These investigations in no way anticipate the cause of tlie 

 electromotor property of the muscular fibre ; they bear only on 

 the laws of its action. They leave very little doubt that the 



