CHAPTER XV 



THE SENSES 



A MAN knows what is going on around him in five ways. 

 He can feel, see, hear, smell, and taste. 



280. Feeling. Nerves of feeling go to every part of 

 the body. Most of them end in the skin. When any- 

 thing touches them, they carry a message about it to the 

 upper part of the brain. These messages are of three 

 kinds : touch, pain, and temperature. 



281. Touch. When anything touches the body, but 

 does not harm it, the nerves carry a message simply of 

 touch. By means of this message the brain tells whether 

 the substance touched is hard or smooth, or round or 

 pointed, or has other qualities. 



The tip of the tongue and the ends of the fingers are 

 very sensitive. The fingers can feel two pins distinctly 

 if they are only one twelfth of an inch apart, while the 

 back feels them as one if they are two inches apart. We 

 use the tips of the fingers if we wish to feel with accuracy. 



By education, the sense of touch can be made very deli- 

 cate. Blind persons learn to do things by touch almost as 

 well as we do by sight. 



282. Pain. If anything touching the cells is harming 

 them, we no longer feel a touch, but only a pain. Then 

 we do not think whether the substance is hard, or smooth, 

 but only that it is doing us harm. So pain tells us if any- 

 thing is harming the body. A toothache shows that a 



