MODIFIED MILK 171 
be noted, is in the protein content. Cow’s milk con- 
tains more than twice the amount of protein found in 
human milk. But this is not all: the casein of cow's 
milk has an acid reaction while that of the human is 
alkaline. The acid condition of the milk casein causes 
it to clot when taken into the stomach which, in the 
case of the calf, does no harm because its stomach is 
adapted to handle such clots. With the baby the situa- 
tion is different; with a small stomach and a small open- 
ing leading from it into the intestines, where the greater 
share of digestion takes place, a clot will cause the baby 
a great deal of discomfort. The alkalinity of human 
milk prevents to a great extent the formation of clots. 
Method of Modifying Milk. As pointed out, cow’s 
milk contains fully twice as much protein as human 
milk, and it is this excessive protein that must be gotten 
rid of in adapting cow’s milk for infant feeding. To 
show how this may be done, we will suppose that ap- 
proximately 225 pounds of modified milk is to be made. 
Take 150 pounds of whole milk and run it through 
a cream separator. Place the skim-milk in a vat, heat 
it to 100° F. and add rennet extract at the rate of 3 
to 4 ounces per 1,000 pounds of milk. When curdled, 
cut the curd in cubes as in Cheddar cheese making and 
stir, gradually bringing the temperature up to 108° to 
110° F. In the course of about 30 minutes the whey 
can be removed from the curd. The whey obtained in 
this way from the 150 of milk will amount to about 
120 pounds. This whey will contain about 0.9 pound 
of protein consisting chiefly of albumen. 
Next take 100 pounds of whole milk and add enough 
of the cream skimmed from the 150 pounds of milk to 
give it a fat content of 3.5% when mixed with the 
