38 



HUMAN BIOLOGY 



other at San Antonio, Texas, during the 1911 maneuvers on the 

 Mexican border. 



35. Water supplies. — In country districts each house 

 usually has its own well, and so the family becomes account- 

 able for its own water supply. In this case great care should 

 be taken to place the well in such a position that none of 

 the drainage from the house or barn can soak through the 

 soil into the well-water. Those who live in large towns 

 and cities almost always obtain their water supply from a 

 common source. This sometimes becomes contaminated 

 by typhoid and other germs, and a disease epidemic then 

 follows. Hence, if there is any doubt as to the purity of a 

 water supply, boards of health should notify the house- 

 holders, and the water, when used for drinking purposes, 

 should then be boiled and kept in bottles on ice until used. 



36. Milk supplies. — Many families in rural communities 

 keep their own cows, and so they can be sure of clean milk 

 if they only take the necessary trouble. Cows, like human 

 beings, need plenty of light, air, wholesome food, and clean 

 surroundings. If any of these are wanting, the animals 

 are likely to become diseased, and the milk is then affected. 

 Great care should be taken also at milking time to see that 



