THE NERVOUS SYSTEM. 117 



at length we arrive at man, who possesses it in its highest 

 form of development. The functions over which the brain 

 presides, are (the sensations, the voluntary motions, and the 

 intellectual and moral faculties?) 



19. (The mind itself is immaterial-*-a principle superadded 

 to matter ; but the brain is the instrument which it employs 

 in all its operations. Though it is not matter, yet it works 

 by means of matter. In like manner, the eye is not sight, 

 but the instrument of sight ; the ear is not hearing, but the 

 organ of hearing ; so the brain is not mind, but the organ 

 of mind. Revelation teaches us all we know, with respect 

 to the powers and capacities of mind, when separate from 

 the body. 



20. The spinal marrow and the nerves are of subordinate 

 importance ; as organs of the nervous system, their use 

 seems to be, to transmit impressions from the organs of 

 sense to the brain ; or the influence of the brain in a con- 

 trary direction to the muscles which are employed for 

 motion. 



21. tThe first class of functions which pertain to the brain 

 are the sensorial.t Though the brain is the actual seat of 

 all impressions, yet the organs of sense and the nerves seem 

 to be the immediate seats of sensation. Indeed, no sensation 

 can be excited in any part or organ, unless- its nervous con- 

 nection with the brain be entire. For example, the sense 

 of touch seems to reside in the ends of the fingers, and that 

 of sight in the eye, yet if the nerve which connects these 

 parts with the brain be divided, no impression is felt, no 

 sensation whatever is excited ; showing conclusively that it 

 is the brain that perceives all impressions made on the organs 

 of sense. 



22. It is a curious fact connected with this subject, that 

 though the brain is the real seat of the sensation, yet it is 

 always referred to the part or organ, on which the impression 

 is made, so that there seems to be a double action, viz., from 

 the organ to the brain, and from the brain back again to the 



