The albumen--or the "white"--of an egg is greatly altered by cooking.
When heated beyond boiling point it becomes a very indigestible
substance. Eggs cooked at a temperature of about 170° F., leaving the
whites soft, are easily digested. A raw egg is ordinarily digested in
1-1/2 hour, while a baked egg requires from 2 to 3 hours. Eggs _baked_
in puddings, or in any other manner, form one of the most insoluble
varieties of albumen.

GELATIN.

Gelatin is obtained from bones, ligaments, and other connective
tissues. In combinations with other foods it has considerable
nutritive value. The place given to it by scientists is to save the
albumen of the body; as it does not help to form tissue or repair
waste it cannot replace albumen entirely. Gelatin will not sustain
life, but when used in the form of soup stock, etc., is considered
valuable as a stimulant.

* * * * *

LEGUMES--PEAS, BEANS AND LENTILS.

These vegetables contain as much protein as meat; yet, this being
inferior in quality to that contained in meat, they can scarcely be
given a place in the same class; therefore we will give them an
intermediate position in food value between meat and grains. From the
standpoint of economy they occupy a high place in nutritive value,
especially for outdoor workers. (See Recipes.)