56 PHYSIOLOGY AND TEMPERANCE. 



apt to draw off too much heat from the body and lessen its 

 vitality. 



10. Some Common Skin Affections. The skin is sub- 

 ject to a variety of diseases. Some of them are due to local 

 causes, such as the irritation of vegetable or animal poisons. 

 The sting of a nettle, the effect of poison ivy, the sting of a 

 bee, or the bite of a mosquito, are examples of these. Certain 

 parasites find in the hair and skin suitable ground for lodg- 

 ing. They grow and multiply, and often cause much irrita- 

 tion of the skin. They are contagious in the sense that they 

 are easily transferred from one child to another. Constant 

 care and watchfulness are necessary to prevent these vile 

 little creatures from infecting a school. 



Stoppage of an oil gland may produce a pimple. If many 

 are affected together, a sort of boil may result. 



The skin may become congested or inflamed from too much 

 heat, as in scalds or burns. The hot sun of summer will 

 burn and inflame parts of the body not accustomed to being 

 exposed to its rays. Erysipelas (St. Anthony's Fire) is 

 an inflammation of the skin, which spreads rapidly and is 

 often very severe. It is contagious, and should be carefully 

 watched. 



11. Effects of Alcohol on the Skin. We will find, 



when we come to speak of digestion, that a part of the food 

 goes to supply the heat of the body. It is a sort of fuel that 

 is regularly fed to the system to keep the body warm, just as 

 a stove is kept going by fresh supplies of coal. In a stove 

 the amount of heat is regulated by opening and closing of 

 draughts and dampers. In the body the heat is kept at a 

 constant standard by the opening and closing of the pores of 

 the skin. The chief duty of the skin is to regulate the heat 

 of the body. Does alcohol affect the skin in any way, so as 

 to interfere with the proper discharge of this duty ? 



The first effect of alcohol upon the skin is to dilate the 



