THE SKIN. 349 



which consists in passing an electric needle down 

 along the root of each hair to the hair papilla, which 

 is then destroyed by a weak current of electricity. 

 The hair is then readily removed and does not re- 

 turn. The loss of hair on the scalp is due to a va- 

 riety of causes, many of which we cannot explain. 

 It often accompanies a prolonged illness, such as 

 typhoid fever, and is then doubtless due to a general 

 emaciation resulting in lack of proper nourishment 

 of the scalp. The loss of hair in such cases is only 

 temporary. Certain neurotic diseases result in a 

 permanent loss and the same may be attributed to 

 some germ diseases of the scalp that infest and de- 

 stroy the hair papillae. In other cases baldness 

 seems to be hereditary. It naturally follows that a 

 healthy condition of the scalp will contribute to a 

 rich growth of hair. Regular massage with a stiff 

 brush no doubt accelerates the blood flow and thus 

 brings about a better nourishment and growth to the 

 hair. 



The natural preservation of hair after death is 

 well known. In Egyptian mummies the hair is well 

 preserved even to its natural color. The hair is thus 

 an important factor in the identification of unknown 

 deceased persons. 



THE NAILS. 



The nails are epidermal structures that are mor- 

 phologically analogous to the hoofs and claws of 

 lower animals. Each nail may be divided into a 

 body, the part that is exposed, and the root that is 

 hidden from view and lies in a fold of the skin. The 



