394 HUMAN PHYSIOLOGY 



the circulation and uses up the oxygen which should be applied 

 to the oxidation of food, then the weight may increase, but it is 

 by the retention of poisonous matter which ought to be removed. 

 No other one cause creates so much disease of the kidneys as does 

 the use of alcohol. Imperfect oxidation of food develops poisons 

 which the kidneys are overtaxed to remove. This may be caused 

 by eating too much, or by eating unwholesome food, or too much of 

 certain kinds of food, as sugar especially; or it may be caused by 

 alcohol. * Fatty degeneration of the kidneys ' is a frequent result 

 of the use of alcoholic drinks. The cells of the tissues become so 

 altered, also, that they fail to act normally by removing only the 

 poisonous substances, and they allow the valuable elements in 

 the blood to be drained off with the waste. This is seen in the 

 serious disease called ' Bright's disease ' in which the albumin 

 which is necessary to health is excreted by the kidneys." — Macy, 

 Physiology. 



The Effects of Alcohol upon the Kidneys. — Dr. McMichael, in the 

 Dietetic and Hygienic Gazette, says, '' Alcohol produces disease 

 of the liver and of the kidneys because these glands are most con- 

 cerned in the throwing out of any poison, and are always, until 

 they are deranged in structure, engaged in removing it from the 

 body.'* He further says that the disease almost universally 

 caused in the liver by alcohol, is one in which the connective tissue 

 framework of the liver increases, taking the place of the liver cells, 

 until the liver is no longer able to perform its function. 



The kidneys may undergo a change similar to that of the liver 

 when alcohol is used, even in moderate amounts, for a long period. 



The Skin 



Structure of the Skin. — In man, the skin is composed of two 

 layers, an outer layer called the epidermis, and an inner layer called 

 the dermis. The outer part of the epidermis is composed of 

 flattened dead cells. It is part of this layer that peels off after 

 sunburn, or that separates from the inner part of the epidermis 

 when a water blister is formed. The epidermis frequently forms 

 callous places which are called into existence by much use of the 



