Human Physiology. 181 



CHAPTER III. 



THE FIVE SENSES. 



"Sense of Touch Skin and Nerves of Sensation Taste Aided by Smell 

 Papillae of the Tongue Uses of Taste Smell Odours Powers of 

 Smell in Men and Animals- Hearing Phenomena of Sound Struc- 

 ture of the Ear Uses of Hearing Sight Structure of the Eye- 

 Wonders of Vision. 



THE soul of man, in this bodily life, holds its ordinary com- 

 munication with the external world through the medium of five 

 senses touch, taste, smell, hearing, and sight. These are 

 the usual, but not the only modes of receiving sensations or 

 impressions of the objects around us. 



By the sense of touch we receive sensations of heat, cold, 

 and an agreeable, exhilarating, or uncomfortable and depress- 

 ing state of the atmosphere, perhaps its electrical condition; 

 of the qualities of the bodies with which we come into contact, 

 as being gaseous, liquid, solid, hard, soft, rough, smooth, 

 sticky, slimy; of the forms of bodies, and the texture and quali- 

 ties which we cannot so well judge by sight. People judge of 

 silk, woollen, and cotton textures, the edges of cutting instru- 

 ments, and many things by feeling better than by sight. 



Nerves of touch are thickly distributed in the skin over the 

 whole body in the true skin under its protecting scarf, the 

 horny cuticle. There are thousands of nervous extremities in 

 every square inch of skin over the entire surface, for the 

 smallest prick causes pain; but the nerves are more numerous, 

 and the touch more exquisite in some parts than in others 

 notably on the end of the tongue, the lips, and the ends of the 

 fingers. Take a pair of fine-pointed dividers, and you can 

 distinguish the two points nearer together in such sensitive 

 regions than on less sensitive portions of the body, as the arms 

 or thighs. 



