THE SKIN 21 



27. Review of Functions of the Skin. Its chief function, 

 one of more importance than all others combined, is protec- 

 tion of the body. The dead outer cells well fit it for this, as 

 does its peculiarity of becoming thicker where friction is 

 greater. Savage man's only protection for his head from 

 the heat of the sun and the blows of enemies, is his hair. 



28. Physiologists usually mention the absorbing power of 

 the skin, but this is very slight ; if it were great, the skin 

 would lack part of its ability to protect. As it is, man can 

 handle poisons without harm, provided there is no break in 

 the epidermis. He can suck with safety the poison from a 

 bite made by a rattlesnake if there is no raw place or break 

 in the mucous membrane of the mouth. If the poison 

 should be swallowed, the stomach would destroy it. Some 

 volatile poisons like the poison ivy can penetrate the skin. 



29. Some writers mention the respiratory or breathing 

 power of the skin and speak of the skin as a third lung, 

 but this is a great exaggeration. The skin probably has 

 about one fiftieth of the breathing capacity of the lungs. 

 The pathetic story told concerning a child who was gilded 

 to represent an angel in a pageant held in honor of one 

 of the popes, may be true. The child is said to have 

 died in a few hours. Death was probably due to some 

 poison absorbed in the process of gilding. A man 

 can live after his body is varnished or covered with a 

 layer of impenetrable substance. But varnishing the skin 

 of an animal covered with fur leads to its death from 

 loss of heat, as the varnish destroys the non-conducting 

 property of the fur. 



30. The skin is an organ of sensation, the nerve fibers 

 going not only to the papillae, but some of the finer fila- 

 ments penetrating even among the deeper epithelial cells. 



31. The skin is an organ of excretion, the chief sub- 

 stances excreted being water, salt, ammonia, and a slight 

 trace of a crystalline solid called urea. 



