SENSE OF TOUCH. 159 



are the immediate instruments of touch. Although covered 

 by the cuticle and mucous web, yet the removal of these by 

 blisters or otherwise, does not increase the sense, but tends 

 to destroy and disturb it. From this arrangement, sensation 

 is communicated through the hair and nails, as well as the 

 cuticle. In animals, of the cat tribe, which are furnished 

 with whiskers, these serve as organs of touch, as their roots 

 terminate in these nervous papillae. 



9. The property of touch belongs to every part of the 

 body, though ; |he hand is considered as its special organ. 

 The great number of bones of which it is composed, make it 

 susceptible of every variety of motion, by which it changes 

 its form, and adapts itself to the inequalities of the surfaces 

 of bodies. What is called the pulp of the fingers, seems 



^composed chiefly of a tissue of blood-vessels and nerves, 

 covered by the cuticle and mucous web, and supported by 

 the nailsjj The delicacy of touch is vastly improved by 

 education and practice. This is shown in the case of the 

 blind, who often can distinguish by touch the different 

 colours, and even their different shades, t This will not ap. 

 pear impossible when we consider that difference of colour 

 may depend on the dispositions, arrangement, and number 

 of the little inequalities which roughen the surface of bodies, 

 even of such as appear the most polished, and thus fit them 

 to reflect certain rays of light, while they absorb the others. 

 That the exercise of this sense is a gratification to the 

 young, is apparent from the eagerness with which the child 

 stretches out his littlo hands to all the objects within his 

 reach, and the pleasure he seems to take in touching them, 

 in all their parts, and running over all their surfaces. 



10. t have already mentioned that the external surface of 

 the body is endowed with this special sensibility^ not only 

 that it might furnish us with a knowledge of the characters 

 of external objects, and so lead us to avoid dangers which 

 surround us, but also to be a source of positive pleasure^ 

 Though in the acuteness of the other senses many animals 



