OF CHEMICAL FORCES. 5 



that the process of nutrition proceeds in those parts of 

 the body where the nerves of sensation and voluntary 

 motion are paralyzed, exactly in the same way as in 

 other parts where these nerves are in the normal condi- 

 tion ; and, on the other hand, that the most energetic 

 volition is incapable of exerting any influence on the 

 contractions of the heart, on the motion of the intes- 

 tines, or on the processes of secretion. 



The higher phenomena of mental existence cannot, 

 in the present state of science, be referred to their 

 proximate, and still less to their ultimate causes. We 

 only know of them, that they exist ; we ascribe them to 

 an immaterial agency, and that, in so far as its manifes- 

 tations are connected with matter, an agency entirely 

 distinct from the vital force, with which it has nothing in 

 common. 



It cannot be denied, that this peculiar force exercises 

 a certain influence on the activity of vegetative life, 

 just as other immaterial agents, such as Light, Heat, 

 Electricity, and Magnetism do ; but this influence is not 

 of a determinative kind, and manifests itself only as an 

 acceleration, a retarding, or a disturbance of the pro- 

 cess of vegetative life. In a manner exactly analogous, 

 the vegetative life reacts on the conscious mental ex- 

 istence. 



There are thus two forces, which are found in activity 

 together ; but consciousness and intellect may be ab- 

 sent in animals as they are in living vegetables, without 

 their vitality being otherwise affected than by the want 

 of a peculiar source of increased energy or of disturb- 

 1* 



