PASTEURIZATION. 189 



Care of Milk. ' ' says : ' ' The greater attention paid to 

 scrupulous cleanliness in handling milk at all stages, 

 the shorter time that elapses between the drawing, 

 straining, and cooling of the milk, and the lower the 

 temperature to which it is cooled, the greater will 

 be its freedom from micro-organisms ; the longer it 

 will retain its normal condition ; the more profitable 

 its production will be and the more wholesome will 

 it be for old and young." In these few words we 

 find the secret of success in handling milk and 

 cream. 



240. Clarification and separation. When a large 

 quantity of milk is handled at one plant for city 

 supply and shipped or hauled to the plant for a 

 considerable distance, it is of the utmost importance 

 if the milk is not very clean, that it be clarified. 

 By clarification I mean that the milk is to be sep- 

 arated and milk and cream run together again be- 

 fore it is used. This should be done whether the 

 milk it to be pasteurized or not. After clarification 

 it should be immediately cooled to as low a temper- 

 ature as possible unless it is to be pasteurized at 

 once. It has been ascertained that in the process of 

 separation a large number of tubercle bacilli and 

 lactic germs are deposited in the separator slime. 

 Grotenfelt in his "Modern Dairy Practice" says: 

 "I have verified in numerous trials that a large num- 

 ber of the bacteria present in milk were removed 

 from the cream and skim milk by the centrifugal 

 force and went into the separator slime." 



241. The grading of mUk. In order that a uniform 

 grade of milk be placed upon the maTket it is neces- 

 sary to select, by an acid test all milk that may indi- 



