XVI REFORMS IN CONDITIONS OF SUPPLY 287 



strainers, is placed the filtering medium, consisting of a specially 

 prepared cotton-wool. A cup-shaped lid with apertures fits on 

 top of this, the whole being kept in position by means of a 

 curved cross-piece which acts as a spring. A fresh piece of 

 the prepared cotton-wool must be used for each batch of milk 

 filtered. 



Cooling. — In every case it is desirable, and in all cases 

 in which the milk has to go by train, or be otherwise kept 



jt^ — 



Fig. 26.— "Ulax" strainer. 



before distribution, it should be imperative, that the milk be 

 cooled. Where proper cooling appliances are not installed 

 the milk churn should be stood in cold water changed several 

 times, but this is a very inefficient substitute for a proper 

 cooling apparatus. 



To prevent bacterial multiplication in transit the value of 

 thorough initial cooling cannot be exaggerated. Milk in bulk 

 in churns cools very slowly, as the following experiment shows. 

 One srallon of milk was warmed in a steam steriliser to about 

 33° C, and the contents poured into a cool two-gallon churn. 

 The rate of cooling was as follows : ^ 



