550 MILK 



frequently carried out by inexperienced persons who are unable to 

 interpret results. The significance of Bacillus coli, of strepto- 

 cocci, and of cellular elements can be reasonably interpreted only 

 by experts. A variety of problems confront the worker. Is the 

 presence of large numbers of bacteria due to early pollution or to 

 multiplication during transportation? Are large numbers of Ba- 

 cillus coli in pasteurized milk the result of inefficient pasteuriza- 

 tion, or are they due to the multiplication of a few heat-resisting 

 individuals? Does the presence of streptococci mean pus or 

 multiplication of harmless varieties? What is the real significance 

 of cellular elements in milk? Is a relatively low fat content due 

 to manipulation, or is it a case of dealing with milk from cows 

 whose milk naturally yields small amounts of fat? 



Questions of this nature must confront the laboratory worker, 

 and to decide the quality of a milk after a single test may result 

 in doing an injustice. As many tests as possible should be made, 

 and the results correlated, if a real history of the milk is to be 

 obtained. If laboratory tests give rise to suspicion that there is 

 something wrong with the milk-supply, the inspector's business is 

 to go up-stream, watch the tributaries, and by the use of appro- 

 priate tests trace the trouble. 



Inspection is an important factor in milk hygiene. It com- 

 mences in the barn, where the veterinary inspector examines the 

 animals for disease. The sanitary inspector looks after cleanli- 

 ness in methods of milk production, care for the well-being and 

 comfort of the cow; he sees to it that the food of the cow is whole- 

 some; that the utensils in use are of good quality and kept clean; 

 that the milk is promptly cooled; that the bottling machine is 

 kept in good condition and that the bottles are clean; that manure 

 and other waste are promptly disposed of, and that proper drain- 

 age takes care of liquid waste. Supervision of equipment and 

 methods of production, of conditions during transportation and 

 delivery are of as much importance as bacteriologic and chemical 

 examination. Laboratory examinations serve as the final control 

 and as reliable indicators when one or more links in the chain 

 are defective. They are a guide to efficient inspection. 



Milk inspection is all important for milk control. Unfor- 

 tunately, there are undesirable inspectors. An inspector should 

 have some knowledge of chemistry, bacteriology, animal hus- 

 bandry, diseases of cattle, farm sanitation, and all the practical 

 elements that enter into the producing and handling of milk. 

 This is not all. He should be a man of personality, who is able 

 to impress the producer with his knowledge, and still one to 

 approach the dairyman as a kindly and interested instructor 

 rather than as a police officer. With the use of tact on the in- 



