HELMHOLTZ IN KONIGSBERG 



or neutral, and sometimes even weakly positive to the 

 longitudinal surface. Du Bois Reymond further 

 states : c But so little did Helmholtz intend to deny 

 the pre-existence of electrical forces in muscle, that, 

 on the contrary, in the paper we are here considering, 

 he allows my hypothesis of the peripolar electromotive 

 molecules full play as the cause of the muscle current, 

 and declares, in so many words, " it stands to reason 

 that the electric forces of the current-surrounded 

 molecules must be taken into account in any theory 

 of their movement." ' Further, Helmholtz suggested 

 a theory to Du Bois Reymond in which the electro- 

 motive effects were harmonised with the phenomena 

 of muscular contracility, but this does not appear to 

 have been published. 



These views of Du Bois Reymond, which had at 

 all events the qualified support of Helmholtz, found an 

 opponent in Ludwig Hermann, then professor in 

 Zurich, and now in the chair in Konigsberg, once 

 occupied by Helmholtz. He demonstrated that in the 

 absolutely uninjured frog's muscle there is no current, 

 and showed conclusively, that the current of the rest- 

 ing muscle, when it is cut in transverse section, as 

 directed by Du Bois Reymond, causes the death of a 

 thin layer of the muscle, and so produces difference of 

 potential. This difference theory refers all electro- 

 motive effects of muscle to two kinds of physiological 

 change. The first part of the theory is, that the dying 

 portion of the substance behaves itself negatively to 

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