1^2 CONTROL OF THE MILK-SUPPLY. 
and consequently the drinking of such milk is far worse than drinking 
fresh milk which is, most likely, supplied chiefly with lactic bacteria. 
Sterilized milk, if it does retain a single spore, will be in time, more 
dangerous than ordinary fresh milk. For this reason, among 
others, this practice of treating milk to superheated steam for the 
purpose of absolute sterilization has disappeared. 
The term sterilization is sometimes applied to the simple boiling 
of milk. This was recommended by physicians long before its 
real significance was understood and has been very widely used in all 
civilized countries. Its ease of application explains the reason for 
its popularity. It is only necessary to place the milk upon the 
stove and allow it to come to a boil, and the end is reached. In 
some countries very little milk is used without such previous boiling, 
and even the children are taught in school that it is dangerous to 
drink milk without such treatment. The purpose aimed at in this 
wide use of boiling, which is commonly, though not properly, 
called "sterilization," is simply to destroy the danger of distributing 
diseases by the destruction of pathogenic bacteria. This purpose 
is certainly achieved, for the boiling temperature does destroy all the 
pathogenic bacteria which are likely to be in milk, since none of 
these are spore producers. 
But several practical objections have arisen: 
1. The bacteria spores are not destroyed, and such milk, if kept, 
will surely undergo a fermentation. But this is of little importance 
if the boiled milk is to be used at once. 
2. The milk acquires the well-known taste of boiled milk which 
is, to most people, unpleasant. People are willing to take boiled 
milk upon an emergency as an ivalid diet, but few will continue its 
use. The taste is not enjoyed, and, rather than drink boiled milk, 
the majority of people will give up drinking milk altogether. This 
is certainly not desirable, since milk forms one of the best and 
cheapest foods. Any treatment which greatly reduces the amount 
used is, in itself, undesirable; and the practice of boiling milk 
certainly does reduce the amount used. 
3. Milk treated to a temperature as high as boiling becomes 
somewhat less easy of digestion and assimilation. The heat pro- 
