330 THE SENSORIAL FUNCTIONS. 



extending continuously from the external organ to 

 the brain, where they all terminate. It is also in- 

 dispensably requisite that these notices of the pre- 

 sence of objects should be transmitted instantly to 

 the brain ; for the slightest delay would be attended 

 with serious evil, and might even lead to fatal con- 

 sequences. The nervous power, of which, in our 

 review of the vital functions, we noticed some of the 

 operations, is the agent employed by nature for this 

 important office of a rapid communication of im- 

 pressions. The velocity with which the nerves sub- 

 servient to sensation transmit the impressions they 

 receive at one extremity, along their whole course, 

 to their termination in the brain, exceeds all mea- 

 surement, and can be compared only to that of 

 electricity passing along a conducting wire. These 

 nerves may, in fact, be regarded as constituting a 

 system of electric telegraphs, established by nature 

 as the general medium of instantaneous transmis- 

 sions of sensorial agencies between all, and even 

 the most distant parts of the body. 



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 lind that 

 the skin, and all those parts of it more particularly 



