58 . J.ECTU11E II. 



pose it to be confined in tubes, neither 

 does the philosophy of the present time 

 require such a supposition, for no one at 

 present will doubt that a subtile substance 

 may be attached to or inhere in a chord 

 without mechanical confinement. Will not 

 a wire when electrified continue to be so, 

 if surrounded by non-conductors? Expe- 

 riments made on the limbs of animals with 

 electricity, produced in the manner first 

 explained by Volta, show that different 

 parts of the body have different conducting 

 powers. Skin and membrane being very 

 bad conductors, and brain, muscle, and 

 blood, being remarkably good ones. 



The celerity with which motions are 

 transmitted from the tangible extremities 

 of nerves most distant from the brain, and 

 the celerity with which volition is trans- 

 mitted to the muscles in consequence of 

 sensations thus induced, are sufficient to 

 convince us that such effects must be 

 produced by the motions of a very mo- 

 bile substance. It is not necessary to 

 suppose that when such motions are trans*- 



