health--one might even say in
spite of the wilful refusal of health.

When one's body is kept rested, nature is constantly throwing off germs
of disease, constantly working, and working most actively, to protect
the body from anything that would interfere with its perfect health.
When one's body is not rested, nature works just as hard, but the tired
body--through its various forms of tension that impede the circulation,
prevent the healthy absorption of food and oxygen, and clog the way so
that impurities cannot be carried off--interferes with nature's work
and thus makes it impossible for her to keep the machine well oiled.
When we are tired, the very fact of being tired makes us more tired,
unless we rest properly.

A great deal--it seems to me more than one-half--of the fatigue in the
world comes from the need of an intelligent understanding of how to
keep rested. The more that lack of intelligence is allowed to grow, the
worse it is going to be for the health of the nation. We have less of
that plain common sense than our grandfathers and grandmothers. They
had less than their fathers and mothers. We need more than our
ancestors, because life is more complicated now, than it was then. We
can get more if we will, because there is more real understanding of
the science of hygiene than our fathers and mothers had before us. Our
need now is to use _practically_ the information which a few
individuals are able to give us, and especially to teach such practical
use to our children.

Let us find out how we would actually go to work to keep rested, and
take the information of plain common sense and use it.

To keep rested we must not overwork our body inside or outside. We must
keep it in an equilibrium of action and rest.

We overwork our body inside when we eat the wrong food and when we eat
too much or not enough of the right food, for then the stomach has more
than its share of work to do, and as the effort to do it well robs the
brain and the whole nervous system, so, of course, the rest of the body
has not its rightful supply of energy and the natural result is great
fatigue.

We overwork our body inside when we do not give it its due amount of
fresh air. The blood needs the oxygen to supply itself and the nerves
and muscles with power to do their work. When the oxygen is not
supplied to the blood, the machinery of the body has to work with so
much less power than really belongs to it, that there is great stra