260 AGRICULTURE ON THE PACIFIC SLOPE 



is allowed to run into the sewer. The water supply of 

 cities is purified in this way. 



The small filters sold for household use are worse 

 than useless, if they cannot be cleaned. If your water 

 is not pure, it should be boiled for a few minutes and 

 kept in a cool place in clean bottles. This is much 

 better than trying to filter it for yourself. 



A small filter is now sold by dealers in camping 

 outfits which permits one to suck up water through a 

 tube and filter it at the same time through a piece of 

 charcoal attached to the end of the tube. This should 

 be used when off on walking trips or excursions, except 

 where the water comes from a good spring. Wells are 

 not to be trusted, as a rule, if near houses. 



Every town should filter its water. It costs little, 

 and prevents cholera, typhoid fever, and summer com- 

 plaint. 



Bacteria in milk. A pure milk supply is so important 

 that it should be obtained at any cost. First of all 

 the cows and persons who milk them must be clean 

 when the cows are milked. Cloth should be stretched 

 over the top of the pail so that the milk must pass 

 through the cloth first. Then the milk should be drawn 

 out of the pail (without taking away the cloth) by a 

 tube (siphon) reaching to the bottom. It should then 

 be cooled and placed in bottles or cans which have been 

 steamed, and not afterwards rinsed. In cities the milk 

 should be delivered in closed bottles. Milk treated in 



