106 
JNO. M. PARKER. 
tient and favoring fermentive changes in the milk. It is to 
the feeding bottle and its contents that attention must be spe¬ 
cially directed in the prevention of autumnal diarrhoea. 
It only occurs in hot weather. A temperature of 6o c F. or 
over favors the development and multiplication of the various 
micro-organisms that are the prime cause of this disease. There 
is no specific micro-organism present, but the presence of all 
toxicogenic bacteria (or bacteria that give off poisonous gases) 
in milk or food of any kind must be avoided. Infants fed ex¬ 
clusively on sterile foods are not liable to be attacked, and vari¬ 
ous methods have been tried to prevent the development of these 
organisms in milk. The principal of these are the pasteurization 
and the sterilization of milk, and in European countries and in 
the West these methods are adopted quite extensively. 
The pasteurization of milk consists in the placing of milk in 
sterile bottles or jars and exposing them to a temperature of 
from i50°F. to i8o°F. Milk treated in this way, cooled to 41 °F. 
and kept at a temperature below 6o°F. will keep sweet and pure 
for several days and “sweet milk may be heated to i8o°F. with¬ 
out any coagulation or burning or any material change taking 
place.” (Year Book Dept, of Agr., 1895.) To pasteurize milk 
with the best results, however, milk must be fresh. It should be 
perfectly pure, and as free as possible from bacteria. Where 
there are any great number of micro-organisms present, and where 
there is the least tendency to sour, even when so slight as not to 
be perceptible to taste, the heat will coagulate the albumen, ren¬ 
dering it more or less indigestible. 
All germs are not destroyed at 180° F., however, and some 
even multiply at that temperature. To totally destroy all germs 
sterilizing at a temperature of 230° F. is required. On the other 
hand, that amount of heat would cause a coagulation of casein, 
and would injure the taste and appearance of the milk, but all 
germs and spores can be destroyed by interrupted heating, i. e ., 
by submitting the milk to a temperature of 180° F. and cooling, 
repeating the process for five or six consecutive days. The 
rapid change of temperature from hot to cold favors the keeping 
