7i 



mitted along the nervous chords, an evident 

 motion of the visible matter of those chords 

 should be induced. Electrical motions 

 take place along a wire without occasioning 

 any visible motion of the metal itself. 



Formerly, it was thought that the mo- 

 tions of the nerves that cause sensation, 

 were the effect of an impulse made on 

 their tangible extremities, which was pro- 

 pagated along the chord to the brain. 

 It seems to be an improvement in modern 



physiology, to attribute sensation to an 



- 



action begun in the nervous fibrils, in 

 consequence of the stimulation which they 

 suffer from such impulses. This opinion 

 is contended for by Doctor Darwin, in 

 his paper on Ocular Spectra, published 

 in the Philosophical Transactions ; and Sir 

 Everard Home has further shewn, that 

 the living principle of nerves has an ir- 

 ritability belonging to it, resembling that 



