PHYSIOLOGY. 69 



seemingly ceased. Both powers, however, are seemingly of 

 equal duration in these respects; and neither power seems 

 to subsist long but in entire and living bodies. " It is 

 strange that Haller could overlook this. You may cut 

 through a nerve belonging to a great number of muscles, such 

 as the great crural nerve : this having lost all its connexion 

 with the brain, still, by the application of a stimulus to the 

 lower portion, the same effect takes place as if it had remained 

 entire. This experiment not only applies to living animals, 

 but if you cut a muscle out of the body, with its nerve attached 

 to it, and apply the same stimulus to the nerve, as has been 

 done by Swammerdam, the same effects will follow as if you 

 apply it to the muscle, so that both the nervous and the muscu- 

 lar power do remain for some time without any connexion with the 

 brain. They subsist also in entire bodies for some time after life 

 has seemingly ceased ; and if we were to determine the circum- 

 stance of life, it would be by saying that life subsists only so long 

 as there is a communication between the brain and other parts 

 of the system ; for every other part almost may be taken away, 

 and the parts attached to the brain seemingly have their entire 

 functions remaining. But other circumstances, such as destroy- 

 ing the functions of the brain by compression, answer the same 

 purpose as removing the parts ; in that case also, the inherent 

 as well as the nervous powers do remain. Both powers, how- 

 ever, are seemingly of equal duration in these respects. This 

 conclusion is intended for Dr. Haller. Dr. Smith's experiments 

 are quite decisive ; he never found that the irritability remained 

 longer in the muscle than the nervous power did in the portion of 

 the nerve adhering to it. Another part of the conclusion is this, 

 * and neither power seems to subsist long, but in entire and living 

 bodies.' Undoubtedly the irritability can subsist for some time se- 

 parate, but there is no instance of its subsisting for any length of 

 time. If, in a tortoise and some other animals, it subsists for some 

 days it is for some days only and it gradually ceases. Every 

 view of the animal economy leads us to consider it as a system, all 

 the parts of which mutually depend upon one another for their 

 several functions; and it will appear from what I shall say 

 afterwards, that the brain is one of the most important parts 

 of this system. Whatever modification it is under whatever 



