LECTURE II. 61 



ceptions of those who are accustomed to 

 exercise their auditory nerves in attending 

 to musical sounds. A train of nervous ac- 

 tions having often taken place, they, like 

 similar actions in muscles, become conca- 

 tenated, and are liable to occur in suc- 

 cession, when one of them is accidentally 

 induced. Both nerves and muscles re- 

 quire temporary respites from action, and 

 are refreshed by sleep. 



The supposition of actions occurring in 

 the nerves, explains many circumstances 

 connected with diseases. Vehement ac- 

 tions may occur in the tangible extremi- 

 ties of nerves, independent of impulses, 

 and occasion severe pain. This seems to 

 happen in the disease called tic douloureux. 

 Ordinarily, actions beginning in the tan- 

 gible extremities of nerves, are regularly 

 transmitted to the brain ; but in cases of 

 nervous pains, actions sometimes seem to 

 begin in the middle of nerves ; and it is 

 probable, that actions beginning in the 

 sensorial extremities of nerves may be pro- 



