THE NERVOUS SYSTEM. 35 



a pin would not be felt. If you touch your body on 

 its skin surface anywhere, even with the fine point 

 of a needle, you are sure to disturb one or more of 

 the nerves of feeling. Quicker than thought they 

 report the impression, according to the degree of its 

 severity, to the brain, which, if the situation at the 

 surface demands it, will promptly return an order, 

 over the nerves of motion, to the muscles of the 

 endangered part, to do their best to get it out of the 

 way of harm. For instance, a mosquito may alight 

 on your forehead so lightly as to make no 

 impression on your nerves of feeling, and, con- 

 sequently, you are not aware of it. But now he 

 punctures the skin and touches a nerve with his 

 wonderful little stiletto. The news of his attack has 

 been received by the brain, and an order sent back 

 for defense and protection. Quicker than thought 

 your hand has come up and routed or crushed the 

 little assassin. 



But the impressions which the nerves df feeling 

 carry to the brain and mind are not all alarming or 

 painful. Many of them are impressions of comfort 

 or pleasure. A gentle breeze fans your body on a 

 hot summer day. Hundreds of nerves are telling 

 it to the mind, which enjoys it as a pleasure. Light 

 impresses the nerve of sight, and beautiful views 

 of form and color are spread before the mind. 

 Sound excites the nerve of hearing and the charms 

 of music are enjoyed. Invisible particles from a 

 rose come in contact with the nerve of smell and we 

 are delighted with the fragrance of the flower. 



