1 66 HUMAN PHYSIOLOGY CHAP, xn 



12. The skin may be kept clean and in a healthy condition 

 by proper bathing whenever necessary. This may be twice a 

 week or oftener, depending upon the season and occupation. 



13. A cold sponge, shower, or plunge bath taken in the 

 morning has a very invigorating effect upon the entire system. 

 A warm bath is most beneficial after severe muscular exertion, 

 and in the evening before retiring. 



14. A bath should not be taken immediately before or after 

 a full meal or severe physical or mental exertion. About three 

 hours after a full meal the body is in the best condition for 

 a bath of any kind. 



15. The clothing should permit the utmost freedom of 

 movement to all organs and members of the body, and contrib- 

 ute to the fullest extent to physical comfort. 



16. All garments worn at night, as well as the bedclothes, 

 should be thoroughly aired and sunned so as to keep them per- 

 fectly dry and free from disease germs. 



17. The kidneys are the most important organs for the 

 excretion of salt, water, and urea; they also excrete other 

 wastes. They cooperate with the skin and lungs in keeping 

 the blood free from all organic waste products. Disease of any 

 one of these organs throws an extra amount of work upon the 

 others. 



18. Disease of the kidneys results in serious impairment of 

 health. The skin and lungs cannot assume the functions of 

 the kidneys. 



19. Diseases of the kidneys may be due to numerous causes, 

 such as : exposure to colds, use of alcohol, condiments, and 

 too much rich food, dislocation of abdominal organs, and 

 infection by certain bacteria. 



