NERVOUS SYSTEM. 367 



review of the vital functions, we noticed some of 

 the operations, is the agent employed by nature 

 for this important office of a rapid communica- 

 tion of impressions. The velocity with which 

 the nerves subservient to sensation transmit the 

 impressions they receive at one extremity, along 

 their whole course, to their termination in the 

 brain, exceeds all measurement, and can be 

 compared only to that of electricity passing 

 along a conducting wire. 



It is evident, therefore, that the brain requires 

 to be furnished with a great number of these 

 nerves, which perform the office of conductors of 

 the subtle influence in question ; and that these 

 nerves must extend from all those parts of the 

 body which are to be rendered sensible, and 

 must unite at their other extremities in that 

 central organ. It is of especial importance that 

 the surface of the body, in particular, should 

 communicate all the impressions received from 

 the contact of external bodies, and that these 

 impressions should produce the most distinct 

 perceptions of touch. Hence we find that the 

 skin, and all those parts of it more particularly 

 intended to be the organs of a delicate touch, 

 are most abundantly supplied with nerves ; each 

 nerve, however, communicating a sensation dis- 

 tinguishable from that of every other, so as to 

 enable the mind to discriminate between them, 

 and refer them to their respective origins in dif- 



