n is used for food are the
glutens of the grains, the legumes, nuts, cheese, the white of egg,
and lean meat.

STARCHES

The starches are by far the most abundant of all elements in human
food. They enter largely into the composition of nearly all plants and
seeds. Under the influence of the sunlight, the green-colored plants
gather up the CO_{2} of the air and, with the water absorbed from the
ground, build up starch. The plant takes all the carbon from which
starch is made from the air, but while the atmosphere contains almost
eighty per cent of nitrogen, the plant is unable to use it; it must
secure its nitrogen from the decaying refuse of the soil. Thus the
plant utilizes the waste products found in air and earth in the
building of its food substances.

Starch exists in the form of small granules. Since each little starch
granule is surrounded by a woody envelope of cellulose, it becomes
necessary to cook all starches thoroughly in order to burst this
cellulose envelope and thus enable the saliva to begin, and other
secretions to continue, the work of digestion.

FRUIT SUGARS

The sugar of fruits represents a form of food requiring practically no
digestion; while the sugar found in beets, the cane plant, and the
maple tree, must be acted upon by the digestive juices of the
intestine before their absorption can take place. During the winter,
the maple tree stores its carbohydrates in its roots in the form of
starch. With the advent of spring Mother Nature begins the digestion
of this starch--actually turns it into sugar--and in the form of the
sweet sap it finds its way up into the tree trunk to be deposited in
the leaves and bark in the form of cellulose, a process very similar
to that performed by digestion in the human body, where starch by
digestion is first turned into sugar, and afterwards deposited in
another form in the liver and muscles.

Dextrine is a form of sugar resulting from thoroughly cooking or
partially digesting starch. There are about twenty-five stages or
forms of dextrine between raw starch and digested starch or fruit
sugar. Dextrine is found in the brown-colored portions of well-toasted
bread.

FATS

Fat is a combination of glycerine and certain fatty acids. As a food,
it is derived from both the animal and the vegetable kingdom. Animal
fat consists of lard, suet, fat meat, etc., while fat of animal origin
is represented by cream, butter, and the yolks of eggs. The vegetable