The Skin and the Kidneys 



195 



the physician wishes remedies to act through the skin, he 

 sometimes raises a small blister, and dusts over the surface 

 some drug in the form of a fine powder. 



4 295. Necessity for Personal Cleanliness. The surface of 

 the skin is continually casting off perspiration, oily material, 

 and dead scales. By friction and 

 regular bathing we are able to get 

 rid of a great deal of this waste 

 material. If this is not frequently 

 and thoroughly done, the oily secre- 

 tion retains the particles of waste 

 substances on the surface of the 

 body, while dust and dirt collect 

 and form a layer upon the skin. 



As this unwholesome layer is a 

 fertile soil in which bacteria may 

 develop, many skin diseases may 

 result from neglect of personal 

 cleanliness. It is also highly prob- 

 able that germs of disease thus 

 adherent to the skin may be 

 absorbed into the system. Para- 

 sitic diseases are greatly favored by 

 the presence of dirt on the skin. 



^296. Why we need to bathe. In 

 bathing we have two distinct objects 

 in view, to keep the skin clean 

 and to invigorate the body as a 

 whole. These are closely related, 

 for the removal of worn-out material from the skin in bath- 

 ing serves indirectly to give vigor to other organs. Thus 

 a cold bath is useful locally to cleanse the skin, and also 

 acts through the nervous system to call out, in response 



FIG. 105. Magnified View 

 of a Sweat Gland with its 

 Duct. 



(The convoluted gland is seen 

 surrounded with big fat cells 

 and may 'be traced through 

 the dermis to its outlet in 

 the horny layers of the epi- 

 dermis.) 



