xii THE SKIN AND THE KIDNEYS 155 



ing matter is deposited in the hair, and it becomes gray. 

 Nerves and little fibers of muscles are in contact with 

 the hair follicles. It is by means of these muscles that 

 the skin ruffles to form goose pimples and the hairs 



FlG. 80. Showing, in A, muscle fibers at rest and hairs in usual position, and, 

 in B, muscle fibers contracted and hairs standing on end. (Modified from 

 Hall by Zinns.) 



" stand on end." The hair has various useful functions 

 besides serving to adorn the human body. The growth 

 on the head protects us against cold, and excessive heat 

 from the sun's rays, and against the effect of blows. 

 The eyebrows, eyelashes, and the hair of the nose and 

 ears all serve as protecting organs. 



The hair should be washed or shampooed often enough 

 to keep the scalp clean and free from dandruff. For 

 this purpose any good toilet soap may be used. A stiff 

 hair brush and a coarse comb with blunt teeth should be 

 freely used to keep the scalp in good condition and the 

 hair in order. If the scalp is pale and the hair thin, a 

 daily massage of a few minutes will improve the circu- 

 lation, and tend to increase the growth of the hair. 



117. Care of the Skin. We have seen that the skin 

 is one of the chief organs for removing wastes, ranking 



