212 



Dairy Bacteriology. 



tion by a modification of the Farrington acid test. Dis- 

 solve one alkaline tablet in an ounce of water. A unit 

 volume of this solution added to a unit volume of milk 



FIG. 41. POOR MILK. 



A plate culture inoculated with 1/1000 of a cubic centimeter of 

 market milk containing 1,680 colonies, which equals 1,680,000 

 bacteria per cubic centimeter. Such milk has poor keeping 

 qualities. 



is equal to 0.1 per cent of acidity. If two measures are 

 provided, one for the alkaline solution holding just 

 twice as much as that used for the milk, the approxi- 

 mate acidity can be quickly determined by mixing a 

 measure of each in a common white cup. If the acidity 

 is above 0.2 per cent the color will remain white; if a 

 pink color develops, it indicates an acidity less than 



