THE SKIN 25 



ebb cold baths may be weakening if prolonged beyond a 

 few seconds. For one with skin relaxed and body sluggish 

 from indoor life, cool baths arouse activity, tone up the 

 body, and may be as beneficial as outdoor exercise in restor- 

 ing vigorous health. As with every hygienic measure, 

 each person must find out by experience what suits him 

 best. 



Clothing was first employed for ornament. In cold climates it aids 

 in maintaining the uniform temperature of the body ; to it man owes 

 his distinction of being the most widely distributed of animal species. 

 Clothing prevents rapid escape of bodily heat by confining air, a non- 

 conductor of heat, in its meshes. Hence, the effect of clothing varies 

 with the weave] likewise with the tendency of its fibers to keep dry, for 

 if water replaces air in the meshes, the body loses heat rapidly. For 

 cool clothing the weave should be hard and tight, for warm clothing it 

 should be soft and loose. The warmth of clothing is affected more by 

 its weave than by its weight. The weave may be tested by stretching ; 

 the fabric with softest weave will stretch the most (Exp. 8). Linen 

 makes the coolest of all clothing because it weaves hard with small 

 meshes ; silk ranks next in coolness. When warmth is desired, linen 

 or cotton garments should be made of fabrics woven like stockings. 

 Linen and cotton both absorb water rapidly and dry rapidly (Exp. 6) ; 

 if woolen did also, it would make the warmest of all clothing, but it 

 dries so slowly (Exp. 7) that it cools the body after the activity is over 

 instead of drying rapidly and, as with linen and cotton, keeping the 

 body cool during the exertion (Exp. o) . Woolen weaves with the 

 largest air meshes of all materials ; hence its warmth increases perspi- 

 ration, but woolen removes perspiration most slowly and tends to relax 

 the skin if the wearer has an active skin or makes active exertion. 

 Woolen is best for underclothing during extreme cold only or for per- 

 sons who never make such vigorous muscular exertion as to perspire. 

 In general, cotton or linen is best for underwear. They possess the 

 added advantages of less cost and of not shrinking out of size and 

 shape when washed. A mixture of cotton and silk or of cotton and 

 wool is more durable than either alone. Cotton and linen, unlike 

 woolen, are not attacked by insect pests. 



It is better to depend more upon outer clothing than underclothing 

 for warmth. In the Gulf states the wearing of woolen outer clothing 

 indoors during warm weather (which lasts eight months) is unhealth- 

 ful and uncleanly because of the perspiration absorbed; this is as 



