THE KIDNEYS AND SKIN. 449 



Persons whose skin will not stand soap can find a good sub- 

 stitute, for washing the hands and face, in a little cornmeal. 

 No doubt many folk go about in very good health with very 

 little washing; contact with the clothes and other external 

 objects keeps its excretions from accumulating on the skin 

 to any very great extent. But apart from the duty of per- 

 sonal cleanliness imposed on man as a social animal 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 than their fair share on the lungs and kidneys, and the 

 evil consequences may be experienced any day when some- 

 thing else puts another extra strain on them. 



Animals, a considerable portion of whose skin has been 

 varnished, die within a few hours. This used to be thought 

 due to poisoning by retained ingredients of the sweat. But 

 the main cause of death seems to be an excessive radiation 

 of heat from the surface of the body, dependent mainly on 

 dilatation of the cutaneous vessels caused by the varnish, 

 though possibly the retention of some poisonous substance 

 usually excreted by the skin may have an influence. The 

 bodily temperature falls in consequence of the great loss of 

 heat until it reaches the fatal point, about 20 0. (68 F.) for 

 rabbits. If the animal be packed in raw cotton or kept in 

 an atmosphere at a temperature of 30 0. (86 F.) it does not 

 die as a consequence of the varnishing, or at least not nearly 

 so soon as it would otherwise die. 



Bathing. The general subject of bathing may be consid- 

 ered here. One object of it is that above mentioned to 

 cleanse the skin; but it is also useful to strengthen and in- 

 vigorate the whole frame. For strong healthy persons a cold 

 bath is the best, except in extremely severe weather, when the 

 temperature of the water should be raised to 15 C. (about 

 60 F.), at which it still feels quite cold to the surface. The 

 first effect of a cold bath is to contract all the skin-vessels 

 and make the surface pallid. This is soon followed by a 

 reaction, in which the skin becomes red and congested, and a 

 glow of warmth is felt in it. The proper time to come out is 

 while this reaction lasts, and after emersion it should be pro- 

 moted by a good rub. If the stay in the cold water be too 

 prolonged the state of reaction passes off, the skin becomes 

 cold and pale and the person feels chilly, uncomforta- 



