170 CITY MILK SUPPLY 



may perhaps be somewhat less safe than natural ice. Despite the fact 

 that there is little danger to be apprehended from the ice supply care 

 should be taken that it is pure for while infection from impure ice is 

 not likely, it is possible. 



Human Contamination of Milk. Man himself is an important source 

 of contamination and sometimes of infection of the milk. The dis- 

 charges of the mouth, nose, ears, anus and urinary bladder are most 

 important. The operations of the toilet are such that the hands are 

 almost inevitably soiled in its use, consequently employees should be 

 instructed to wash their hands thoroughly before leaving the closet. 

 It is the habit of man to be constantly fingering his mouth and picking 

 his nose and ears consequently the hands most of the time are unclean. 

 So, it is important that milkers and others should wash their hands care- 

 fully before beginning work. They should be taught there is an invisible 

 dirt on the hands which is likely to seriously injure the product and that 

 for this reason it is for the interest of the dairy that the hands should be 

 kept away from the milk as much as possible. The practice of milking 

 with wet hands is to be condemned as one that is sure to contaminate 

 the milk. Milk is sometimes polluted and possibly infected by the cough- 

 ing of one handling it. Fine drops of saliva are ejected into the air and 

 fall with their contaminated germs into the milk. The clothes of people 

 working about milk should be clean because if they are dirty they are 

 foul-smelling and so may impart odor to the milk and also dirt and germs 

 get into the milk from the clothes. Certified dairies make a point of the 

 milking and the subsequent handling of milk being done by employees 

 dressed in clean and sometimes in sterile clothes. It is too much to 

 expect the ordinary dairyman to attempt anything of the sort but he 

 can conveniently, and without increasing the expense of laundering, have 

 clean overalls and jumper for milking in, that he can use for ordinary 

 farm work when they become soiled. 



Contamination of Milk by Domestic Animals and Vermin. There 

 is some danger of milk being contaminated by domestic animals and 

 vermin. There are dairies where cats are kept to catch mice and rats 

 and at milking time puss gets at the milk if she can. In the inferior 

 class of dairies, the doors of the milk house are often left open consequently 

 hens get in, and their droppings as well as those of mice and rats fall 

 into any utensils that are carelessly left standing mouth upward. Once 

 in a great while it is reported that a rat has been found drowned in a 

 can of milk that has been left uncovered in the creamery over night. , 



Contamination of Milk by Flies. While this sort of contamination 

 is disgusting it is not of common enough occurrence to make it very 

 important but the contamination of milk by flies in summer is constant 

 and serious. Many of the best dairies are trying to cope with it. Flies 

 are fond of milk and swarm wherever it is exposed, consequently in the 



