348 



ELECTRO-PHYSIOLOGY 



CHAP. 



potential analogous with that of the muscle prism. But the 

 same result would ensue with two other presumptive dispositions 

 of the electromotive planes. A hollow cylinder, e.g., the surface 

 of which is coated with zinc, may be filled with acid water, the 

 entire apparatus being immersed in the same : schema B (I.e.) will 

 then correspond with the distribution of potential. Lastly, if a 

 hollow zinc cylinder with copper end-surfaces is examined under 

 the same conditions, schema C will become effective (Fig. 109). 



Which of these three schemata is actually realised in the 

 muscle cannot prima facie be determined by experiment. In 

 regard to the first, it must be further observed that (in the sense 

 of the preceding observations) the one solid cylinder may be 

 replaced by any number of little cylindrical or rounded bodies 

 (" peripolar molecules"), each provided with positive longitudinal, 

 and negative transverse, sections, provided they are regularly 



cor 



3 3" 

 33i)3' 



FIG. 110. Schema of peripolar (a) and dipolar (b) molecules. (Hermann's Handb. i. 1.) 

 Parelectronomic molecules at natural section. 



arranged somewhat after the accompanying diagram (Fig. 110, a). 

 With reference to the real anatomical relations of the muscle, the 

 first case, in the modified form last stated, coincides with the 

 molecular theory of du Bois-Keymond, the second with a hypo- 

 thesis of Griinhagen, which postulates an electromotive opposi- 

 tion between muscle- fibrils and surrounding nutritive fluids, 

 while, finally, the third is fundamental to Hermann's alteration 

 theory, which presumes that electromotive action is set up at the 

 artificial transverse section. 



If any two points of different potential upon the neutral 

 sheath are joined by a deriving circuit, a branch of the current 

 will flow into this circuit, corresponding with a fraction of the 

 internal E.M.F., since these currents, particularly in the imme- 

 diate vicinity of the electromotive planes, undergo a large 

 amount of short circuiting. Therefore, as already urged by 

 Hermann, it is important in many cases to take into considcra- 



