218 Agricultural Bacteriology. 



introduced and an outbreak of typhoid fever occurs in 

 the family. 



On the diary farm, as previously mentioned, an oppor- 

 tunity is offered for the farther spread of the disease by 

 means of the milk infected from the water or in some 

 other way. The wise course to follow is to supply thd 

 home with water that is so protected that it cannot be the 

 cause of disease, even if material containing typhoid bac- 

 teria is deposited near the well. This demands a well 

 into which no water can enter except that which has per- 

 colated through a sufficient bed of soil to insure its free- 

 dom from all harmful bacteria. This demands again the 

 positive exclusion of water from the upper layers of the 

 soil by the use of a non-porous wall, preferably an iron * 

 pipe, and the protection of the well at the surface. 



Springs are the outlet of under-ground streams. 

 Spring water is free from bacteria as it flows from the 

 ground and is, of course, an excellent water for house- 

 hold use, but there is often danger of surface pollution 

 entering the basin of the spring, unless it is carefully 

 protected. 



The first consideration in obtaining water for the home 

 should be to secure a safe supply that is thoroughly pro- 

 tected from all possible pollution with disease-producing 

 bacteria. An adequate supply is also a consideration of 

 great importance in order that the farm home may be 

 provided with the modern conveniences. These so-called 

 "modern conveniences" such as water carriage for dis- 

 posal of sewage, drinking water under pressure and also 

 hot and cold water supplies for lavatory, laundry, and 

 bath have been regarded as obtainable only in the city, 

 and yet all of these sanitary arrangements are readily 

 secured if an adequate water supply is available. 



