THE SKIN AND KIDNEYS 113 



SUMMARY 



1. The skin is made of a thick, tough part called the 



derma, and a thin protective covering of epithelium 

 called the epidermis. 



2. The derma contains blood tubes, nerves, and perspira- 



tory glands. 



3. The epidermis protects the derma and forms the nails 



and hair. 



4. Oxidation of albumin makes a substance called urea, 



which must be given off from the body. Urea and 

 carbonic acid gas are the main waste substances of 

 the body. 



5. The kidneys and perspiratory glands are coils of fine 



tubes, made of epithelial cells, which take water, 

 urea, and mineral matters from the blood. 



6. We must bathe our bodies and wash our clothes so 



as to wash away the waste matters from the skin. 



7. Slops must be carried away from the house so that the 



poisonous matter will neither get into the well nor 

 make foul gases. 



8. Alcohol causes poisons to be formed in the* body which 



the kidneys try to throw off, but they become over- 

 worked and diseased in the attempt. 



9. Alcohol weakens the skin so it cannot help the kidneys 



get rid of the waste matter. It also gives the skin 

 an unpleasant appearance, 

 ov. PHYSIOL. (INTER.) 8 



