358 MAN --AN ADAPTIVE MECHANISM 



alkalies and acids, most of the cellular phenomena 

 of animals could be reproduced. 



After exhaustive studies of nerve currents, Williams 

 and Crehore, making observations with an Einthoven 

 string galvanometer, constructed an artificial nerve 

 which gave convincing evidence that the nerve action 

 current is identical with electricity. An extract from 

 the report of these experiments of Williams and Crehore 

 to the Society for Experimental Biology and Medicine, 

 reads as follows : 



" Nearly two centuries ago it was surmised that the 

 nervous impulse might be of the nature of an electric 

 current, but in the absence of definite proof the hypoth- 

 esis was rejected, especially as objections were raised 

 to it which seemed insuperable. It is difficult, if not 

 altogether impossible, to reconcile all experimental 

 results with the consequences of the molecular theory. 

 If, however, we regard the nerve as an electrical con- 

 ductor with distributed capacity, we are able to ac- 

 count for many of the fundamental experimental 

 phenomena and also to predict the results of new ex- 

 perimental conditions. It has long been known that 

 the speed of electricity on wires is less than the speed 

 in free space and the formulae for calculating these 

 velocities are well understood. The rate of propaga- 

 tion of electricity in a conductor similar in form, size 

 and material to a nerve fiber should be, according to 

 these formulae, of approximately the same order of 

 magnitude as has been measured for the rate of the 

 nervous impulse. 



" The enormous reduction of velocity (about ten 

 million times) is chiefly attributable to the great ohmic 



