chapter we find that water composes
three-fifths of the entire body. The elasticity of muscles, cartilage,
tendons, and even of bones is due in great part to the water which
these tissues contain. The amount of water required by a healthy man
in twenty-four hours (children in proportion) is on the average
between 50 and 60 ounces, beside about 25 ounces taken as an
ingredient of solid food, thus making a total of from 75 to 85 ounces.
One of the most universal dietetic failings is neglect to take enough
water into the system. Dr. Gilman Thompson gives the following uses of
water in the body:--

(1) It enters into the chemical composition of the tissues; (2) it
forms the chief ingredient of all the fluids of the body and maintains
their proper degree of dilution; (3) by moistening various surfaces of
the body, such as the mucous and serous membranes, it prevents
friction and the uncomfortable symptoms which might result from
drying; (4) it furnishes in the blood and lymph a fluid medium by
which food may be taken to remote parts of the body and the waste
matter removed, thus promoting rapid tissue changes; (5) it serves as
a distributer of body heat; (6) it regulates the body temperature by
the physical processes of absorption and evaporation.

Salts (Mineral Matter).--Use of Salts in Food.

(1) To regulate the specific gravity of the blood and other fluids of
the body; (2) to preserve the tissues from disorganization and
putrefaction; (3) to enter into the composition of the teeth and
bones. These are only a few of the uses of salts in the body, but are
sufficient for our purpose. Fruits and nuts contain the least quantity
of salts, meat ranks next, then vegetables and pulses, cereals contain
most of all (Chambers). Sodium chloride (common salt) is the most
important and valuable salt. It must not however be used in excess.
Potassium salts rank next in importance.[4] Calcium, phosphorus,
sulphur and iron are included in this class.

The quantity of salts or mineral matter contained in some important
articles of vegetable and animal food is shown in this table (Church):

_Mineral Matter in 1,000 lbs. of 14 Vegetable Products._

Lbs.
Apples 4
Rice 5
Wheaten flour 7
Turnips 8
Potatoes 10
Barley 11
Cabbage 12
Bread