HYGIENE OF THE SKIN. 275 



well wash their hair every day, as it takes so long to dry; 

 but there is no reason why a man should not immerse his 

 head when he takes his bath. Except on parts of the skin 

 especially exposed to contamination, soap should only be 

 used occasionally say once or twice a week; its employ- 

 ment is quite unnecessary for cleanliness, except on ex- 

 posed parts of the body, if frequent bathing is a habit and the 

 skin be well rubbed afterwards until dry. Soap nearly al- 

 ways contains an excess of alkali, which in itself injures some 

 skins, and, besides, is apt to combine chemically with the 

 sebaceous secretion and carry it too freely away. Persons 

 whose skin is injured by soap, will find in cornmeal 

 a good substitute. No doubt many folk go about in very 

 good health with very little washing; contact with the 

 clothes and other external objects keeps the skin excretions 

 from accumulating to any very great extent. But apart from 

 the duty of personal cleanliness imposed on every one as a 

 member of society in daily intercourse with others, the mere 

 fact that the healthy body can manage to get along under 

 unfavorable conditions is no reason for exposing it to them. 

 A clogged skin throws more work on the lungs and kid- 

 neys than their fair share, and the evil consequences may 

 be experienced any day when something else throws an- 

 other extra strain upon them. 



Bathing. One object of bathing is to cleanse the skin; 



How often should soap be used in the bath? Why is the too fre- 

 quent use of soap not desirable? What is a good substitute for it in 

 cases where soap is injurious to the skin? How does an unclean skin 

 influence internal organs? When are its results apt to show them- 

 selves? 



glands secrete more vigorously when the body is heated, and so cool it and keep 

 down its temperature. In most fevers the sweat glands are paralyzed; and the 

 abnormally warm body is not cooled by loss of the heat, which in health would 

 have been carried off by the evaporating sweat. 



