digestion.

The principal animal fats are butter, cream, lard, suet, the fat of
mutton, pork, bacon, beef, fish and cod liver oil. The vegetable fats
and oils chiefly used as food are derived from seeds, olives, and
nuts. The most important fats and oils for household purposes are:

BUTTER.

Butter, which contains from 5 to 10 per cent. of water, 11.7 per cent.
fat, 0.5 per cent. casein, 0.5 per cent. milk sugar (Konig). The
addition of salt to butter prevents fermentation. Butter will not
support life when taken alone, but with other foods is highly
nutritious and digestible.

CREAM.

Cream is one of the most wholesome and agreeable forms of fat. It is
an excellent substitute for cod liver oil in tuberculosis. Ice cream
when eaten slowly is very nutritious.

LARD.

Lard is hog fat, separated by melting.

SUET.

Suet is beef fat surrounding the kidneys.

COTTOLENE.

Cottolene is a preparation of cotton-seed oil.

OLEOMARGARINE.

Oleomargarine is a preparation of beef fat provided as a substitute
for butter.

OLIVE OIL.

Olive oil is obtained from the fruit, and is considered to be very
wholesome; in some cases being preferred to either cod-liver oil or
cream for consumptives.

COTTON SEED OIL.

Cotton seed oil is frequently substituted for olive oil.

NUTS.

Nuts contain a good deal of oil.

CHAPTER VII.

Carbohydrate Foods.

The idea of starchy foods is usually connected with such substances as
laundry starch, cornstarch, arrow root, etc. These are, of course,
more concentrated forms of starch than potatoes, rice, etc. Many
starchy foods contain other ingredients, and some are especially rich
in proteids.

The following table may help to make this clear (Atwater):--

PERCENTAGE OF STARCH IN VEGETABLE FOODS.

-----------------+-----------
| Per Cent.
-----------------+-----------
Wheat bread | 55.5
Wheat flour | 75.6
Graham flour | 71.8
Rye flour | 78.7
Buckwheat flour | 77.6
Beans | 57.4
Oatmeal | 68.1
Cornmeal | 71.0
Rice | 79.4
Potatoes | 21.3
Sweet Potatoes | 21.1
Turnips | 6.9
Carrots | 10.1
Cabbage | 6.2
Melons | 2.5
Apples | 14.3
Pears | 16.3
Bananas | 23.3
-----------------+-----------

It is estimated that starch co