CONTROL OF CITY MILK SUPPLY 935 
The matter of sterile milk bottles means a great deal 
to the health of milk consumers, and milk inspectors 
should see to it that this phase of inspection receives the 
necessary consideration. There is urgent need, too, of 
directing more attention to milk cans. A large per- 
centage of milk shipping cans is entirely unfit for han- 
dling milk. Rusty and badly bruised cans should be con- 
demned. Another matter that should be insisted upon is 
_ to have the cans washed and sterilized before returning 
them to the milk producers. 
Pasteurization. A number of cities in the United 
States have deemed it wise to require the pasteurization 
of all milk coming from cows that are not known to be 
free from tuberculosis. If properly done, there is no 
question whatever that pasteurization of milk as it is now 
received in most cities, is a safe-guard to health. See 
chapter XII. 
Temperature and Age Regulations. To hold milk 
in good condition until it reaches the consumer requires 
that it be kept at a low temperature. Many cities have 
passed regulations fixing a minimum temperature at 
which milk shall be transported and handled, and good 
results have followed such regulations. 
Low temperatures, however, like many other good 
things, are often abused as in the case of ice cream 
manufacturers. Some hold ice cream weeks before it 
goes to the consumer, believing that no bacterial develop- 
ment takes place at storage temperatures. While cold 
materially retards the growth of all bacteria and com- 
pletely stops that of many, there is probably no minimum 
temperature at which all bacterial development stops. 
That there is abundant bacterial development in cream 
is conclusively shown in Bulletin 41, of the Hygienic 
