THE MILK SUPPLY OF CITIES. 631 



amount of milk which is used raw is really very small, and appar- 

 ently its use in this condition is destined to cease. The younger 

 generation of physicians are now being taught that raw milk is a 

 dangerous food, and in some countries even the children in the 

 schools are being taught that it is not safe to drink raw milk. Such 

 teaching can have only one result, and that is the reduction in the 

 amount of milk consumed. Much less milk is used in Europe than 

 in this country. It is used for tea or coffee or for cooking, and 

 of course for infant feeding, but for any one to drink milk as we 

 do in this country is certainly a rarity. The suspicion under which 

 milk has been placed has decreased its use. 



The dangers which are feared in milk are of course connected 

 with the distribution of disease. Most persons who thus hesitate 

 to use milk have simply a vague fear, without knowing just what 

 is to be feared. When we put together all the facts in our posses- 

 sion we find that there is good reason for believing that milk is 

 sometimes concerned in the distribution of the following well- 

 known diseases and some obscure ones: The first is tuberculosis, 

 which is a disease attacking the cow, and, if located in the mam- 

 mary gland, may infect the milk with tubercle bacilli, and may sub- 

 sequently produce the disease in the person who drinks the milk. 

 It should be stated, however, that there is good reason for believing 

 that the danger from this source has been overrated. Second, we 

 have diphtheria, which apparently may also attack the cow. The 

 diphtheria germs may get into the milk from the cow, and they cer- 

 tainly do get into the milk occasionally from secondary sources. 

 Scarlet fever apparently is distributed by milk, though whether this 

 disease may come from the cow or only by secondary contamination 

 of the milk is not yet positively settled. Typhoid fever has in a 

 large number of cases been traced to the milk supply. This disease, 

 however, does not occur in the cow, and the germs always get into 

 the milk from a secondary source, such as water or contact with a 

 person who has the disease. Cholera may be. distributed by milk, 

 but this is of course of little importance. Of these disease bacteria, 

 the tubercle bacillus probably never grows in milk, while the ty- 

 phoid and diphtheria germs do. The most common of all troubles 

 attributed to milk are those somewhat obscure intestinal diseases 

 which attack people especially in the summer months, and are par- 

 ticularly common among children. Prominent among these stands 

 cholera infantum. These latter troubles, according to our present 

 knowledge, are not produced by distinct species of bacteria finding 

 entrance into the body and growing there, as are the other diseases 

 mentioned. They appear to be produced by bacterial poisons which 

 are in the milk. The bacteria probably several different varie- 



