METHODS OF PURIFYING WASH- WATER 271 



water does not carry enough oxygen in solution to supply the 

 germs which form the real filtering agency. 



If the intermittent process is used, the first water filtered after 

 the intervening period should not be used. During the inter- 

 mission, or during the time that the water is shut off, germs 

 develop and come through the filter-bed with the water that is 

 filtered. 



Advantages of Purifying Wash-water for Butter. The chief 

 advantage of purifying wash-water for butter is that the keeping 

 quality of the butter is improved, and if the proper skill and 

 care have been applied in the other steps of manufacture, a pure 

 sanitary product is obtained. The sanitary efficiency reached 

 by purifying the wash-water constitutes no small consideration. 

 Germs producing contagious diseases are thus prevented from 

 spreading. 



