180 



DAIRY FARMING 



from the milk, according to the 

 logical laboratories, to determine 



FIG. 51. Influence of temperature 

 on the growth of bacteria, a repre- 

 sents one original bacterium ; 6, the de- 

 scendants of one bacterium in milk kept 

 24 hours at 50 F. ; c represents the 

 number of descendants when milk is not 

 cooled. 



cooled with ice to a temperature 

 temperature for a good ice box 

 lated below : 



method used in bacterio- 

 the number of bacteria 

 present. There were 

 found to be 13,000 bac- 

 teria per cubic centimeter 

 in the fresh milk. This 

 is a low count, showing 

 that the milk had been 

 taken under excellent 

 sanitary conditions. One 

 can was cooled at once 

 to 50 by placing it in ice 

 water and stirring. The 

 other can still showed a 

 temperature of 90. Both 

 were now put in a room 

 of 50, which is a typical 

 The results are tabu- 



The bacteria counts were made in both samples at the 

 end of 36 hours. The cooled sample contained 15,000 bac- 

 teria per cubic centimeter, and the uncooled the enormous 

 number of 52,500,000 in the same quantity. The sample 



