THE SKIN AND ITS SECRETIONS. 329 



mals, as in frogs, the exchange of gas through the skin is of great 

 importance. 



As the exchange of gas through the skin in man and mammalia 

 is very small, it follows that the injurious and dangerous effects 

 caused by covering the skin with varnish, oil, or the like, can hardly 

 depend on a prevented exchange of gas. After varnishing the skin 

 there is a considerable loss of heat, and the animal quickly dies. 

 If the animal, on the contrary, be guarded from this loss of heat, it 

 may be saved, or kept at least alive, for a longer time. This effect 

 was supposed to be due to a poisoning caused by a retention of one 

 or more substances of the perspiration (perspirabile retentum), ac- 

 companied by fever and increased loss of heat through the skin; 

 but this statement has not been substantiated. This phenomenon 

 seems to be due to other causes, and at least in certain animals 

 (rabbits) death seems to ensue from the paralyzation of the vaso- 

 motor nerves. In anastomosis the loss of heat through the skin 

 seems to be increased to such an extent that the animal dies from 

 the lowered temperature. 



TJHITBBSITY 



