iv ELECTROMOTIVE ACTIOX IX MUSCLE 345 



witnessed in the adductor muscle of Anodonta. Each muscle- 

 cell must therefore be regarded as free from current in the 

 uninjured state. If the longitudinal current disappears entirely 

 on injuring a polymerous muscle when the progress of rigor is 

 arrested at the nearest tendinous intersection, the question arises 

 whether there is no means of limiting the invading process of 

 mortification from the artificial cross-section in a monomerous 

 muscle, and thus abolishing the muscle current. The excised 

 muscle cannot possibly be saved, but it is conceivable that if 

 circulation were maintained, a muscle cut transversely might 

 heal up again. Engelmann (I.e.) found in fact that ordinary 

 skeletal muscle (frog's sartorius) did become gradually current- 

 less again after subcutaneous incisions ; if the artificial section 

 loses its negative potential under the influence of normal condi- 

 tions of nutrition, the natural ends of the fibres, during life, 

 could certainly not be the seat of electromotive action. 



All these facts concur to show that striated muscles are 

 free from current when perfectly uninjured, and that the " current 

 of rest in muscle " implies the existence of artificial cross-sections, 

 mechanical, thermic, or chemical. 



Passing to the different attempts at explanation of electro- 

 motive action in the injured " resting " muscle, it must in the 

 first place be remarked that one of the two theories which till 

 recently stood in sharp contrast must now be regarded as dis- 

 proved, at least in the form in which it was originally pro- 

 pounded by du Bois-Keymond. Since Hermann's epoch-making 

 work, the view has more and more gained ground, that in the 

 complicated processes within the living substance, chemical action 

 deserves at least as much attention as the physical symptoms, 

 and that from any one given phenomenon it is not permissible 

 to draw a parallel between tissue (e.g. living muscle or nerve) 

 and a purely physical schema, and to treat it on this assump- 

 tion. Yet on account of its historical interest, as well as in 

 regard to future discussion, we must give a brief account of du 

 Bois-Reymond's " molecular theory " ; the more so because an 

 attempt has recently been made to revive it, although in a 

 different form (Bernstein). Moreover, it gives an opportunity of 

 discussing some facts that are important to the sequel, with 

 regard to the distribution of current in animal conductors. 



If a body, such as the transversely bisected muscle, is the 



