WHY THERE IS A MILK PROBLEM 29 



pared with that from other possible sources of disease, 

 is a question which the data of sanitary science are 

 not as yet sufficient to answer. For present practical 

 purposes we may say, in the words of an investigator 

 who has made a noteworthy examination of the evi- 

 dence on the question, 17 that " the accumulated evidence 

 of scores upon scores of definitely demonstrated milk- 

 borne epidemics is enough to show that raw market 

 milk is always a risky food." 



A Practical Definition of "Pure Milk" 



To sum up the whole matter, we wish milk which is: 



1. Free from infection of human or animal source. 



2. Free from dirt, filth, and other foreign matter. 



3. Free from deleterious bacterial contamination or 

 development. 



4. Free from adulteration and of known food value. 

 Such milk may, in a practical sense, be termed 



"pure." 



These requirements may further be summed up in 

 the three words: safety, decency, nutrition, 



Taking safety and decency as the objects of sanita- 

 tion per se, we shall find that if we secure milk which 

 meets the requirement of decency, or cleanliness, in 

 the highest degree, we have gone a long way toward 

 obtaining also safety. But experience shows that the 

 two conditions are by no means synonymous and that 

 if safety is to be entirely ensured the product must be 

 subjected to a precautionary process such as pasteur- 

 ization before using. Neither a clean milk which is 

 still somewhat unsafe nor a safe (pasteurized) milk 

 which is unclean meets the requirements. 



