DIRTY MILK 75 



in stale, warm, and dirty milk frequently found upon the 

 market. 



While the number of bacteria are not so dangerous as the 

 kind, there is, however, no safety in numbers. We have 

 to judge the good bacteria by the company they keep, and 

 therefore must look askance upon bacteria -laden milk. 

 The number of the bacteria in milk at once gives a clue as 

 to (1) the cleanliness of the methods employed, (2) the 

 temperature at which the milk has been held, and (3) the 

 age of the milk. Bacterial counts, then, are of great prac- 

 tical use to the health officer. In fact, bacterial counts have 

 become indispensable in order to control and regulate the 

 milk supply. With bacterial counts as a guide it is compar- 

 atively easy to determine the cause of trouble or to locate 

 just where the trouble takes place. With a proper diag- 

 nosis it becomes easy to institute proper treatment and 

 to prevent its recurrence. 



The enumeration of bacteria in milk is, therefore, the 

 readiest and cheapest method at our disposal to determine 

 the general sanitary quality and grade of the milk. The 

 laboratory results serve as a guide to direct the efforts 

 of the inspector, and they also may be used to confirm the 

 conclusions arrived at from an inspection of the dairies 

 and dairy farms. 



It should be borne in mind that while the bacteriological 

 examination of milk has its uses, it also has distinct limi- 

 tations. Some of these have already been noted. From a 

 practical standpoint the long time required to obtain re- 

 sults is its greatest drawback. Professor Theobald Smith 

 states: — 



One of the serious limitations to the present bacteriological 

 examination of milk as practiced by boards of health, even where 

 the most elaborate laboratory tests are carried out, fail to trace 

 the evils to their sources, since only mixed milk is examined. It 

 may be compared to hunting in the Mississippi River delta for 

 what has been poured into the river at Minneapohs. It would be 



