CHAPTER I. 



MILK AND ITS PRESERVATION. 



Milk as it comes from a liealtliy cow fed on pure food is abso- 

 lutely pure and sterile, that is, if we could secure it without ad- 

 mission of air in a sterilized bottle, it would keep if not for 

 ever for a very long time indeed. 



Practically this is of course impossible, and thousands of 

 germs (bacteria) float in the dust laden air, adhere to the 

 udder, the flanks of the cow, the hands and the clothing of 

 the milker. 



Even supposing that the utmost precaution is taken, that 

 the cows are carded and brushed, that the udder, and the hands 

 of the milker are washed, that the barn is thoroughly ven- 

 tilated just before milking, even then remains the favorable 

 breeding place for bacteria, the end of the milk duct in the 

 teats of the cow where they find the best temperature and 

 the best nutrition in the few drops of milk which remain from 

 the previous milking. 



But it must not be supposed that all these bacteria are 

 undesirable, some of them do no harm, and some of them are 

 useful, not only in the manufacture of cheese and butter but 

 also in aiding us to digest the milk. 



This explains why there is a difference of opinion among 

 physicians as to the desirability of giving infants pasteurized 

 or sterilized milk. 



I am therefore of the opinion that wherever we are sure 

 of getting milk from a healthy cow under veterinary inspec- 

 tion and with the above mentioned safeguards, as well as the 

 additional one of using only sterilized vessels, or at least those 

 which have been exposed to steam or boiling water for 10 or 

 15 minutes, we have done all that can be expected even in this 

 "antiseptic'' age. 



But, when we come to the practical task of supplying 



