MILK 199 



made of white duck will last a long time and can be sterilized almost 

 indefinitely. 



The milker may not only be the source of a very large number 

 of harmless bacteria, but the largest source of disease germs that 

 get into milk. The milker may be the immediate source of dis- 

 ease germs or may transmit them from another person. The disease 

 germs that get into milk are largely from human origins, infectious 

 diseases that pass individual to individual. A grave mistake has 

 been made in the past by allowing persons ill with contagious dis- 

 eases to enter a cow stable or dairy where milk is handled. Many 

 an epidemic of diptheria, scarlet fever and typhoid has been traced 

 to a case of illness on the dairy farm, which was not properly quar- 

 antined and cared for. One high grade milk handling concern 

 requires that if a case of contagious disease arises in the dairy of one 

 of its patrons, that the milk supply be withheld till the patient has 

 passed the danger limit of conveying the disease germs. The milk 

 produced, however, is paid for during the quarantine. It is very 

 difficult to make the average individual understand or even believe 

 that our worst diseases are caused by special kinds of bacteria, and 

 that these bacteria can be transmitted to a healthy individual, who 

 is likely to-contract the same disease. (Conn B. 51.) 



Bacteria Decrease in Milk After Drawing. In contrast with 

 this generally accepted opinion, investigators have from time to 

 time made the statement that for a certain length of time the num- 

 ber of bacteria decreases, so that milk when a few hours old contains 

 a smaller number of organisms than it did when first obtained. 

 Which of these conditions actually takas place in milk is of great 

 practical importance to all milk handlers, since it bears upon the 

 importance of immediate cooling. If all the bacteria contained in 

 the fresh milk developed from the very outset, the value and im- 

 portance of immediate cooling can not be over-emphasized, but if, 

 on the other hand, there is a falling off in all species during the first 

 few hours, it would only be necessary to cool the milk before the 

 time of minimum numbers had passed and they again commenced 

 to multiply. 



The decrease in the numbers of the normal milk bacteria dur- 

 ing the first few hours after milking is not properly to be attributed 

 to germicidal condition or property possessed by the milk, but 

 simply of the natural dropping out of those species which do not 

 find the milk a suitable medium in which to develop. (Conn. 

 B. 37.) 



Kinds Rather than Numbers. The great host of bacteria are 

 workers for the common good. They are transformers, cleaning up 

 the accumulations of plant and animal life that would otherwise clog 

 and encumber the soil to the extent of preventing the existence of 

 even plant and animal life, on the earth. All these products they con- 

 vert into absolutely necessary plant foods. There are a few kinds 

 of bacteria which are harmful to man and animals in that they 

 produce disease. It would be very unreasonable to condemn the 

 whole group of plants because there are a few poisonous plants. 



