56 LECTUllE 11. 



knee, it was the seat of the disorder. In 

 like manner, persons who have had their 

 limbs amputated, can scarcely believe that 

 they are removed, because of the pain and 

 other sensations they still seem to feel in 

 them. In either of these cases, motions 

 being excited in the middle of nerves, and 

 transmitted to the brain, are attributed to 

 a disordered state of those parts from 

 which such motions have heretofore ori- 

 ginated. 



If, then, it be admitted that sensation 

 exists in the brain, and that volition pro- 

 ceeds from that organ, it necessarily fol- 

 lows that motions must be transmitted to 

 and fro along the nervous chords, whenever 

 they take place. It was fornierly supposed 

 that these chords were passive, and might 

 be made mechanically to vibrate, but their 

 want of elasticity and tension, and their 

 pulpy origins and terminations, are circum- 

 stances which render such a supposition 

 inadmissible. Physiologists were there- 

 fore led to conjecture that the nervous 

 fibrils were tubular, and that they contained 



