I$2 PHYSICAL CHEMISTRY IN MEDICINE. 



As soon, however, as the one electrode is placed upon 

 an artificially produced cross-section of a muscle in other 

 words, along the contents of the fibrils the well-known 

 current of rest passes in the outer circuit toward the 

 negative exposed portions of the muscle plasma. The 

 experiments of BERNSTEIN have shown that this current 

 follows very accurately the typical laws governing ionic 

 concentration chains. The same holds for the current 

 of rest in nerves. Stimulation of the nerve brings about 

 the well-known phenomenon of negative variation, in 

 that it alters the permeability for ions. 



Similar phenomena are observed in the electric organ 

 of the torpedo, which has been studied by BERNSTEIN 

 and TSCHERMAK. This organ consists of numerous 

 plate-like cells arranged upon each other in a way similar 

 to the plates of a voltaic pile and possessing a nervous 

 end brush upon one side only. 



When through nervous stimulation this side becomes 

 more permeable for negative ions, an electric shock is 

 produced through summation of the charges of the single 

 cells, the intensity of which does not need to exceed that 

 of a muscle current. As measurements indicate, the pro- 

 duction of electricity in the electric organ seems also to 

 follow in the main the thermodynamic laws governing 

 concentration chains. 



Let us return once more to the current of rest in muscle, 

 which we have attributed to the semi-permeability of the 

 plasma membranes for ions. If we imagine the per- 

 meability of this plasma membrane to be altered through 

 some agency that precipitates protein or causes it to go 

 into solution, then we may expect parallel variations in 

 the current of rest. When HOBER dipped the surface of 



