156 NEEVE FOKCE. CHAP. XI. 



according to, the state of nutrition of the nerve 

 tissue? Do not all these facts shew, that an intimate 

 relation exists between these two forces — between 

 the electric force in the tissue and the nerve force — 

 and therefore what right have we to suppose that 

 any other force but the electric force is connected 

 with the nerve ? 



All this may be granted, but the premises do not 

 justify the conclusion. There may be no necessary 

 connection between the electric state of the tissue and 

 nerve force beyond that of being a condition, and 

 perhaps a necessary condition, for the manifestation 

 of nerve force. I will not go so far as this, and say 

 that the electric force of the nerve has no connection 

 whatever with nerve force ; but only this, that nerve 

 force is not merely the electric force of the tissue 

 converted into current force, as it has been supposed. 

 Whether the electric force of the tissue is converted 

 into nerve force during nerve action is another 

 question, and perhaps the question for us to solve. 

 At present, we have no experimental evidence to 

 prove this supposition; for we have not obtained 

 any indication of a decided loss in the electric state 

 of the tissue, a sudden decrease in the nerve current 

 during nerve action, to indicate such a conversion. 

 The evidence, however, is not sufficiently decisive 

 of the question, and at present it may be considered 

 an open one". 



"■ I have not thought it necessary to adduce other well-known 

 evidence to shew the difference between the action of nerve 



