1 86 PHARMACEUTICAL BACTERIOLOGY 



Freshly drawn milk is not germ-free, even under the most aseptic and 

 sanitary conditions and surroundings. As a rule even the milk in the 

 udder contains some germs, in spite of the fact that milk possesses de- 

 cidedly bactericidal properties. However, the milk from different animals 

 varies in this regard. The bacterial impurities of freshly drawn milk are 

 traceable to the skin of the cow, the dust and filth about cow stables, the 

 vessel containing the milk, and above all to the hands of the milkers. 

 The milker is often the cause of inoculating the milk with disease germs, 

 as typhoid, acute dysentery, diphtheria, scarlet fever, small-pox, and tuber- 

 culosis. The medical journals cite cases of typhoid epidemics traceable 

 to milkers who were "t3^hoid carriers" without actually suffering from 

 the disease. Cows are very susceptible to tuberculosis, and the milk from 

 tuberculous animals has infected thousands upon thousands of children 

 and many adults. 



Since milk is an excellent culture medium for a great variety of germs, 

 it is evident that, under favorable conditions, it may be a fruitful source 

 of infections. Serious epidemics of typhoid fever and of diphtheria have 

 been traceable to and exactly limited to the milk route of a certain dairy- 

 man. Tuberculous infections of the children in a number of families have 

 been traceable to the milk from a single animal. As a rule mixed milk 

 (that is the milk from many animals) is safer than the milk from a single 

 animal, though this is not necessarily always the case. The milk from 

 animals that are free from disease and that are tested regularly once each 

 year) for tuberculosis, and that are kept under sanitary conditions, is 

 absolutely safe, provided the containers are clean and the milkers and 

 others in the dairying establishment are free from latent or active com- 

 municable disease and are cleanly in their habits. The number of germs 

 in freshly drawn milk varies from looo to several millions per cc, and is 

 directly proportional (within the limits indicated) to the cleanliness and 

 sanitary conditions of the dairying establishment. The bacterial content 

 of milk from the same source is of course higher in warm and hot weather 

 than it is in cold weather, other things being equal. Certain dairying 

 estabhshments supply what is known as " certified milk," or milk which is 

 certified by the board of health as coming from animals that are regularly 

 tested for tuberculosis and which are kept under the sanitary conditions 

 imposed by the milk commission or by the board of health, furthermore, 

 such milk must be bottled in sterilized bottled which are hermetically 

 sealed and placed on ice at once and kept on ice until delivered to the 

 consumer. There is, however, a lack of uniformity in the regulations 

 governmg the supply of certified milk in different communities. The 

 following conditions should prevail: 



a. All cows should be healthy, that is, free from diseases of all kinds. 



