THE FUNCTIONS OP THE NERVOUS SYSTEM. 269 



whose function is supported by stimuli peculiar to themselves, being still 

 supplied with nerves, of the use of which Haller gave no satisfactory account. 

 It appeared to me that the question could only be determined by some expe- 

 riment capable of directly ascertaining whether the excitability of muscles 

 is maintained by the influence they receive from the nei-ves, or impaired as by 

 other stimuli. On trial, the latter was found to be the case. Muscles whose 

 nerves had been divided, sustained the action of the same stimulus longer than 

 those whose nerves were entire, and which consequently were exposed to the 

 action both of the nervous power applied by the will of the animal and the 

 artificial stimulus*. The power of the muscle, therefore, is independent of 

 the nervous power, and is affected by it in the same way as by other stimuli. 



Tlie experiments by which all the other functions just mentioned, with the 

 exception of the maintenance of animal temperature, have been ascertained to 

 be functions of the nervous power, I have laid before the Society, which has 

 done me the honour to publish them. From these experiments it appeared 

 that the functions in question were always destroyed by depriving their 

 organs of the influence of the nervous system. That the maintenance of 

 animal temperature is a function of the nervous system, properly so called, 

 appears from a variety of facts generally known, the temperature either of a 

 part or of the whole body being lessened by any cause that impairs the action 

 of particular nerves in the former instance, or of the whole nervous system in 

 the latter. The question then is, is the nervous system capable of all these 

 functions after the sensorial power is withdrawn ? 



At the moment of what we call death, the sensorial functions cease, the 

 animal no longer feels or wills. Whether the nervous functions properly so 

 called still continue, can only be determined by experiment. That the nei-ves 

 when stimulated are still capable of exciting the muscles of voluntary motion 

 is a fact generally admitted ; and that they are still capable of exciting the 

 action of the muscles of involuntary motion, appears from many experiments 

 related in the second paper, which I had the honour to present to the Society, 

 and which was published in the Philosophical Transactions of 1815. That 

 the nervous system is capable of causing the evolution of caloric, which 

 supports animal temperature after the sensorial power is withdrawn, appears 

 * My Treatise on the Vital Functions, third edition, Exper. 34, 35. 



