260 



SOME CHAPTERS ON THE 



rather than introduce confusion by the employment of theoreti- 

 cally more perfect but unknown expressions. 



The explanation of these terms is simple. If in an isoelectric 

 nerve an injury be made at any point, that spot becomes electrically 



Co. 



Zn 



Figl. 



Current of iiy'ury. 



negative (zincative ! ) to the uninjured part, and this difference of 

 potential gives rise to the current of injury (Fig. 1). 



If such an injured nerve be excited, the uninjured part also 

 becomes electrically negative (zincative), and as this gives rise to 



B. 



EotxiL 



an opposing current to the current of injury, the latter appears to 

 be diminished, and therefore the result is to produce a diminution 

 or " negative variation " of the injury current (Fig. 2A). 



If an uninjured nerve be excited, the normal effect is that a 

 wave of zincativity passes down the nerve, each point becoming 



Like the zinc of a Daniell cell. 



