640 
It was soon pointed out by bacteriologists that Soxhlet’s process 
was not sufficient to sterilize the milk, and that the remaining organ- 
isms grew and, according to Fliigge, were capable of producing 
harmful results. 
Further, it was found that the heating of milk for prolonged pe- 
riods or at high temperatures was neither necessary nor desirable; 
and recourse was then had to the pasteurization process. As will be 
shown later, the confusion between “ sterilized ” and “ pasteurized ” 
milk has been largely instrumental in throwing discredit upon the 
latter process. 
Harm has also been done by the misleading use of the term “ pasteu- 
rized milk,” which has popularly been construed to mean a superior 
quality of milk, in the same sense that antiseptic surgery is a great 
advance upon the old time methods. “ Pasteurized milk ” really 
means heated milk, and is not necessarily synonymous with “ clean 
milk,” “ good milk,” or “ pure milk.” The particular object of the 
heating is to destroy the harmful bacteria. In order to correct this 
misconception concerning “ pasteurized milk,” it would be better to 
discontinue the use of the term and use in its place “ heated milk,” 
stating the degree of heat and the time of exposure on each bottle, as 
well as the date on which the milk was heated. 
Pasteurization does not mean simply the heating of milk ; the sub- 
sequent rapid cooling is a very important part of the process. 
If heated milk is cooled slowly it remains at a temperature be- 
tween 20° and 37° C. for a long time. This is the best temperature 
for the development of bacteria and their toxic products, and it 
requires only a few hours under such conditions to produce an 
enormous growth. 
Pasteurized milk must be handled at least as carefully as raw milk, 
if not more so. Pathogenic bacteria grow more readily in heated 
than in raw milk. The “ germicidal ” properties of the milk are 
destroyed by high heating, and finally the surviving bacteria do 
not have so hard a struggle for existence in the heated milk. It 
must not be forgotten that pasteurization kills only the major por- 
tion of the nonspore-bearing bacteria, and that a large number of 
micro-organisms remain and, if permitted to grow and multiply, they 
may occasionally produce undesirable qualities or perhaps poisonous 
properties in the milk. 
It must be quite evident to anyone who gives the matter thoughtful 
attention that the heating of milk, like the use of antiseptics, is an 
expedient, rather than an ideal procedure. “Antisepsis ” was a great 
improvement in surgery, but “ asepsis,” or the absence of germs, is the 
ideal. In the same sense, heating improves bacteria-laden and dirty 
milk, but clean milk is the end we must seek. “ Pure milk is better 
than purified milk.” 
