Categories: OUR DRINK
Sources: A Handbook Of Health
The Need of Water in the Body-Engine. If you have ever taken a long
railway journey, you will remember that, about every two or three hours,
you would stop longer than usual at some station, or switch, for the
engine to take in water. No matter how briskly the fire burns in the
furnace, or how much good coal you may shovel into it, if there be no
water in the boiler above it to expand and make steam, the engine will
do no work. And an abundant supply of water is just as necessary in our
own bodies, although not used in just the same way as in the engine.
The singular thing about water, both in a locomotive and in our own
bodies is that, absolutely necessary as it is, it is neither burned up
nor broken down in any way, in making the machine go; so that it gives
off no energy, as our food does, but simply changes its form slightly.
Exactly the same amount of water, to the ounce, or even the teaspoonful,
that is poured into the boiler of an engine, is given off through its
funnel and escape-pipes in the form of steam; and precisely the same
amount of water which we pour into our stomachs will reappear on the
surface of the body again in the form of the vapor from the lungs, the
perspiration from the skin, and the water from the kidneys. It goes
completely through the engine, or the body, enables the one to work and
the other to live, and yet comes out unchanged.
Just how water works in the engine we know--the heat from the furnace
changes it into steam, which means that heat expands it, or makes it
fill more space. This swelling pushes forward the cylinder that starts
the wheels of the engine. The next puff gives them another whirl, and in
a few minutes the big locomotive is puffing steadily down the track.
Water is Necessary to Life. Just how water works in the body we do not
know, as most of it is not even turned into steam or vapor. But this
much we do know, that life cannot exist in the absence of water. Odd as
it may seem to us at first sight, ninety-five, yes, ninety-nine per cent
of our body cells are water-animals, and can live and grow only when
literally swimming in water.
The scaly cells on the surface of our skin, our hair, and the tips of
our nails are the only parts of us that live in air. In fact, over
five-sixths of the weight and bulk of our bodies is made up of water.
Some one has quaintly, but truthfully, described the human body as
composed of a few pounds of charcoal, a bushel of air, half a peck of
lime, and a couple of handfuls of salt dissolved in four buckets of
water. The reason why nearly all our foods, as we have seen, contain
such large amounts of water is that they, also, are the results of
life--the tissues and products of plants or animals.
Water Frees the Body from Waste Substances. Water in the body, then,
is necessary to life itself. But another most important use is to wash
out all the waste substances from the different organs and tissues and
carry them to the liver, the kidneys, the lungs, and the skin, where
they can be burned up and got rid of. We must keep our bodies well
flushed with water, just as we should keep a free current of water
flowing through our drain-pipes and sewers.
It Keeps the Body from Getting Over-heated. In summer time, or in hot
climates the year round, an abundant supply of water is of great
importance in keeping the body from becoming overheated, by pouring
itself out on the skin in the form of perspiration, and cooling us by
evaporation, as we shall see in the chapter on the skin.
The Meaning of Thirst. None of us who has ever been a mile or more
away from a well, or brook, on a hot summer's day needs to be told how
necessary water is, for comfort as well as for health. The appetite
which we have developed for it--thirst, as we call it--is the most
tremendous and powerful craving that we can feel, and the results of
water starvation are as serious and as quick in coming as is the
keenness of our thirst. Men in fairly good condition, if they are at
rest, and not exposed to hardship, and have plenty of water to drink,
can survive without food for from two to four weeks; but if deprived of
water, they will perish in agony in from two to three days.
We should Drink Three Pints of Water a Day. Although all our foods,
either as we find them in the state of nature, or as they come on the
table cooked and prepared for eating, contain large quantities of water,
this is not enough for the needs of the body; to keep in good health we
must also drink in some form about three pints, or six glassfuls, of
water in the course of the day. Part of this goes, as you will remember
(p. 16), to dissolve the food so that it can be readily absorbed by our
body cells in the process of digestion.