600 SPECIFIC OFFICE OF THE 



ception, memory, volition, instinct, and all the 

 attributes of mind, to direct the various move- 

 ments of the body, but not to supply the moving 

 power, to generate ideas, but not organic pro- 

 ducts. It is very true, that the nervous system is 

 far more highly developed in warm than in cold 

 blooded animals ; but we shall see presently, that 

 this is owing to the greater activity of nutrition 

 in the former. It is also very true, that when the 

 nerves going to a voluntary muscle are irritated, 

 contractions are produced, and that, when di- 

 vided, it can no longer contract in obedience to 

 the commands of the will. But if the locomotive 

 organs be not supplied with arterial blood, they 

 become cold, insensible, and paralytic, whatever 

 the condition of the brain may be. And if the 

 blood be not supplied continually with caloric by 

 respiration, it cannot excite the brain to think 

 and will, the nerves to feel, the muscles to con- 

 tract, and the glands to secrete.* 



* In his late History of the Inductive Sciences, Mr. Whewell 

 observes, that " the phenomena of the nervous system bring us 

 in a striking manner to the passage from the physical to the 

 hyperphysical. sciences;" and he adds, that " the nervous fluid 

 can neither be mechanical, chemical, nor physical, that it must 

 cease to be a fluid before its motions can become sensation and 

 thought." (Vol. iii. pp. 422 430.) But if the nervous fluid be 

 neither mechanical, chemical, nor physical, it must be a nonentity, 

 or a mere metaphysical quiddity, and should therefore be excluded 

 from the inductive sciences. " What can we reason but from 

 what we know ?" Yet Mr. Earle has described the circulation of 

 the nervous fluid with as much confidence as if it were a real 



