300 THE OUTGO OF ENERGY 



from the longitudinal surface to the cross-section 

 of the whole muscle. The region of maximum 

 positive potential is thereby brought towards the 

 obtuse angle of the oblique cross-section, and the 

 region of maximum negative potential is dis- 

 placed towards the acute angle, as actually 

 observed. 



When it was found by Bernstein, Hermann, 

 and others, that uninjured muscle showed no 

 difference of potential, DuBois-Eeymond as- 

 sumed that in the natural, uninjured state the 

 end of the muscle in contact with the tendon 

 (the " natural cross- section ") is composed of a 

 layer of molecules which have their positive in- 

 stead of negative surface turned towards the 

 tendon. 



The highly artificial and complicated structure 

 which DuBois was compelled to erect on this 

 foundation in order to explain all the electrical 

 phenomena of living tissue, cannot be discussed 

 here. The chief argument against the molecular 

 theory of muscle and nerve currents is that the 

 phenomena can be explained in a simpler way. 



Alteration Theory. This hypothesis, in the 

 making of which Hermann and Hering have 

 been especially active, explains the electromo- 

 tive forces of nerve and muscle by alterations in 

 the chemical composition of the tissue at the 



