12 SELLING MILK 



milk and unclean milk, because they did not know 

 how. Some milk drinkers prefer to drink clean 

 milk. Cleanliness, therefore, has a market value. 

 There would be a market for clean milk if it 

 could be identified from the other kind. 



Cleanliness costs money. It costs money to 

 keep dairy utensils smooth and in good repair. 

 It costs money to wash and sterilize. It costs 

 money to brush and wash cows, and clean stables, 

 and to wash milkers' hands. It costs money 

 to milk carefully, and to cool milk. 



At last a way has been found to measure 

 cleanliness. This measurement consists of test- 

 ing milk for bacteria. 



