.30 THE FUNCTIONS OF LIFE. 



substance, and consisting of a soft, pulpy matter, of 

 a greyish-white colour, exhibiting traces of a fibrous 

 structure. This substance has been termed wewviwe. 

 The name of hrain is given to a particular mass of 

 neurine placed in the interior of the body, where it 

 is carefully protected from injury. 



The sensations, for exciting which the brain is 

 the material instrument, are the result of certain 

 impressions made on particular parts of the body, 

 and conveyed to that organ by the medium of fila- 

 ments, composed of a similar substance, and termed 

 7ierves. In this way, then, it has been provided 

 that a communication shall be established between 

 the sentient principle and the external objects, by 

 which its activity is to be excited, and on which it 

 is to be dependent for the elements of all its affec- 

 tions, both of sensation and of intellect. A consi- 

 derable portion of this treatise will be occupied 

 with the developement of the series of means by 

 which impressions from external objects are made 

 on the appropriate organs that are provided to 

 receive and collect them, so as not only to give rise 

 to varied sensations, but also to convey a know- 

 ledge of the existence and different qualities of the 

 objects which produce them. This latter faculty is 

 termed Perception. 



But in the formation of animals it was not the 

 intention of Providence to endow them with the 

 mere capacity of being affected by surrounding 

 objects, and of deriving from them various sensa- 

 tions of pleasure and of pain, without granting 

 them the power of controlling these effects, and of 

 acting on those objects in return. The faculties of 

 sensation and perception, in beings destined to be 



