MECHANICAL RESPONSE OF NERVE 



531 



become a non-conductor. Conduction, therefore, is not 

 alone dependent on anatomical structure, but requires also 

 a certain molecular condition. A nerve, whose continuity 

 remains uninterrupted, may nevertheless undergo paralysis 

 and cease to conduct. Recovery may then, in many in- 

 stances, be brought about by tetanisation. 



Thus, by means of mechanical response, obtained with 

 a magnification of only fifty times, we have been able to 

 demonstrate not only those results which may be observed 

 by the most sensitive galvanometer, but also others which 

 were never so detected. The magnification thus employed 

 in the Kunchangraph, however, is here, as already stated, 

 only in its lowest terms. When this is further exalted, 

 still further and important phenomena regarding the exci- 

 tatory changes in nerve are revealed, and some of these will 



described in the next chapter. 



