PHYSICAL ANt> LITERARY, ^h 



mediately dependent on their influence; 

 fince opium, which produces its efFeds, yo/f /y, 

 by aflFeding the nervous fyftcm (m, n & 

 o)y deftroys thofe powers fo fuddenly. 

 I know it has been lately argued by a cele- 

 brated author, that the irritability of the 

 mufcles muft be independent of the nerves, 

 becaufe the mufcles of animals preferve a 

 power of moving when irritated, for fome 

 tim€ after the communication between them 

 and the brain, by means of the nerves, is cut 

 off*. But lince a folution of opium applied 

 to the abdominal mufcles of frogs, merely 

 by its adtion on the nerves, puts a flop to 

 the irritability or moving power of the heart, 

 much fooner than the deftrudtion of the brain 

 and fpinal mai;row (g) ; is it not reafonablc 

 to conclude, that the tremulous motions of 

 irritated mufcles after their nerves are tied, 

 proceed from the integrity of the nervous 

 filaments below the ligature, and the ner- 

 vous power ftill remaining in them or in the 

 mufcular fibres themfelves "^ 



The tying or cutting of a nerve, only 

 prevents the derivation of any new infiumce 



from 



• A£la Gotcing. vol. ii. p. 134, 5:c. 



