246 ADVANCED PHYSIOLOGY 



himself thoroughly awake, arouse his nerve centers and start 

 the human machine going for the day. 



Hot Baths. There are times when hot baths are desirable. 

 Warmth is sure to produce an expansion of the blood vessels 

 of the skin, and thus to a certain extent draw blood from the 

 internal organs. This may be very beneficial; for example, 

 it may enable one to get to sleep, or rest when restless, since 

 it draws blood from the brain. When one has the first symp- 

 toms of a cold, a hot bath, or even heating the feet in hot 

 water, may withdraw the blood from the inflamed throat or 

 nasal cavities and check the onset of the cold. This method 

 of causing the expansion of the vessels is not so good an 

 exercise for the skin as the cold bath, and is not really an in- 

 vigorating stimulant; it tends to leave the skin soft and deli- 

 cate, and the body should be warmly covered after such a 

 bath, and not exposed to any chill. Hot baths should never 

 be taken immediately after meals, for the blood rushing to 

 the skin to fill the relaxed capillaries is taken from the diges- 

 tive organs which then need it. Skin activity is the best 

 guard against the various skin diseases. A skin kept healthy 

 by bathing and friction will ward off many an attack of para- 

 sitic bacteria to which an unhealthful skin would yield. 



CLOTHING 



Much contradictory advice is given concerning the kind and 

 amount of clothing it is best to wear. Fortunately the body 

 so easily adapts itself to conditions that it can get along with 

 many differences in method of treatment.. While specific 

 rules for clothing cannot be given, certain principles are 

 involved. 



Clothing serves two purposes: (1) to conserve warmth, and 

 (2) to absorb the perspiration of the body. The amount of 

 warmth that any fabric seems to give is dependent not only 

 on its thickness, or weight, but also upon the size and num- 

 ber of air spaces in the cloth. Air is a very poor conductor 



