PUBLIC SCHOOL DOMESTIC SCIENCE

CHAPTER I.

The Relation of Food to the Body.

In order to understand the relation of food to the sustenance and
repairing of the body, it will be necessary to learn, first, of what
the body is composed, and the corresponding elements contained in the
food required to build and keep the body in a healthy condition. The
following table gives the approximate analysis of a man weighing 148
pounds:--

Oxygen 92.1 pounds.
Hydrogen 14.6 "
Carbon 31.6 "
Nitrogen 4.6 "
Phosphorus 1.4 "
Calcium 2.8 "
Sulphur 0.24 "
Chlorine 0.12 "
Sodium 0.12 "
Iron 0.02 "
Potassium 0.34 "
Magnesium 0.04 "
Silica ? "
Fluorine 0.02 "
------
Total 148.00 pounds.

As food contains all these elements, and as there is constant wearing
and repair going on in the body, it will be readily seen how necessary
some knowledge of the relation of food to the body is, in order to
preserve health.

Hydrogen and oxygen combined form water, hence we find from the above
calculation that about three-fifths of the body is composed of water.
Carbon is a solid: diamonds are nearly pure carbon; "lead" of lead
pencils, anthracite coal and coke are impure forms of carbon. Carbon
combined with other elements in the body makes about one-fifth of the
whole weight. Carbon with oxygen will burn. In this way the carbon
taken into the body as food, when combined with the oxygen of the
inhaled air, yields heat to keep the body warm, and force--muscular
strength--for work. The carbonic acid (or carbon dioxide) is given out
through the lungs and skin. In the further study of carbonaceous
foods, their relation to the body as fuel will be more clearly
understood, as carbon is the most important fuel element. Phosphorus
is a solid. According to the table, about one pound six ounces would
be found in a body weighing 148 pounds. United with oxygen, phosphorus
forms what is known as phosphoric acid; this, with lime, makes
phosphate of lime, in which form it is found in the bones and teeth;
it is found also in the brain and nerves, flesh and blood. Hydrogen is
a gas, and like carbon