THE SUPPLY OF MILK 



301 



Most large cities now send inspectors to the farms from which 

 milk is supplied. Cards are used which score the health of the 

 cows, the cleanliness of their surroundings, the health of the work- 

 ers, the care and construction of the utensils, and the methods of 

 handling the milk. Farms that do not accept certain standards 

 of cleanliness are not allowed to have their milk become part of 

 the city supply. 



Tuberculosis and Milk. — Many dairy herds in this country are 

 infected with tuberculosis. It is also known that the tubercle 

 bacillus of cattle causes 

 some kinds of tuberculosis 

 in young children. Fortu- 

 nately, the tuberculosis 

 germ does not grow in milk, 

 so that even if milk from 

 tuberculous cattle should 

 get into our supply, it 

 would be diluted with the 

 milk of healthy cattle. In 

 order to protect our milk 

 supply from these germs it 

 would be necessary to kill 

 all tubercular cattle or to 

 pasteurize the milk so as to 

 kill the germs in it. 



Other Disease Germs in 

 Milk. — We have already 

 learned how typhoid may 

 be spread througii milk. 

 Usually such outbreaks of 

 typhoid may be traced to 

 a single case of the disease, 

 often a person who is a 'Hy- 

 phoid carrier," i.e. one who 



is not suffering from the effects of the disease but who carries the 

 germs in his body. Sometimes the milk cans may be washed in 

 contaminated water or the cows get the germs on their udders 

 by wading in a polluted stream. Diphtheria, septic sore throat. 



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Typhoid may be spread in a city through 

 an infected milk supply. The black spots 

 mean cases of typhoid. A, a farm where ty- 

 phoid exists. The dashes in the streets repre- 

 sent milk routes. B, a second farm which 

 sends part of its milk to A. The milk canf3 

 from B are washed at farm A and sent back 

 to B. A few cases of typhoid appear along 

 j5's milk route. How do you account for 

 that? 



