60 ILLINOIS ACADEMY OF SCIENCE 



SANITARY ASPECT OF MILK SUPPLIES. 



p. G. HMNEMANN. 



Sanitary milk is a much debated question in modern times. 

 \l\\k is one of the most important articles of food and, in- 

 cluding milk products — such as butter, cheese, buttermilk, 

 etc., — forms the basis for dishes or beverages at every meal. 

 During the first year of human life milk is practically the only 

 food. Milk is also excellent food for bacteria, which multiply 

 in milk at an enormous rate. The production of milk is one 

 of the oldest industries known. Methods of production have 

 been brought down through many generations and conse- 

 (|uently are difficult to change. The tendency of the milk 

 traffic of today is towards concentration. Still there are prob- 

 ably more producers of milk in relation to the total amount 

 of milk consumed, than of any other commodity. 



Improvement in milk supplies must come from various 

 sources and the problem must be attacked from various angles. 

 Education of producer and consumer is the keynote to the 

 situation. The methods in vogue at present for improving 

 milk supplies are concentrated necessarily on elimination of 

 disease germs. The presence of these germs in milk or water 

 and other articles of food is difficult to detect. Disease bac- 

 teria, if present, multiply but slowly in milk, if it is kept at 

 low temperatures. Also, the number of disease germs is usual- 

 ly small if compared with the number of harmless bacteria 

 always present in milk. With modern bacteriological 

 methods, therefore, disease germs are easily overlooked. In- 

 dicators have to be used in milk as well as in water. In water 

 the presence of colon bacilli is usually taken as an indication 

 of the presence of disease germs. Colon bacilli come from the 

 intestinal canal of man and may indicate the presence of 

 germs of intestinal diseases. Colon bacilli from other sources 

 are of no value in this respect. Colon bacilli in milk indicate 

 fecal contamination, but since they are derived from the cow, 

 they do not lead us to assume that disease germs are present, 

 since cows are not susceptible to intestinal infections of man. 

 Fecal contamination, direct or indirect through dust, is the 

 most common source of bacteria in milk. It is clear from 

 the foregoing argument, that total numbers of bacteria in 

 milk are, as far as present knowledge goes, the only index by 

 which we can judge milk. 



The question now is obvious, whether a low bacterial 

 count is sufficient to guarantee safety of milk. AVe do not 

 think so. A low count gives no adequate assurance that patho- 

 genic germs from "germ carriers" have not entered. Carriers 



