t feed you and keep you
healthy are grown by the heat of the sun. So if it were not for the
sunlight we should all starve to death.

While sunlight is pouring down from the sun to the earth, it is
warming and cleaning the air, burning up any poisonous gases, or
germs, that may be in it. By heating the air, it starts it to rising.
If you will watch, you can see the air shimmering and rising from an
open field on a broiling summer day, or wavering and rushing upward
from a hot stove or an open register in winter. Hold a little feather
fluff or blow a puff of flour above a hot stove, and it will go
sailing up toward the ceiling. As the heated air rises, the cooler air
around rushes in to fill the place that it has left, and the outdoor
"drafts" are made that we call _winds_.

These winds keep the air moving about in all directions constantly,
like water in a boiling pot, and in this way keep it fresh and pure
and clean. If it were not for this, the air would become foul and damp
and stagnant, like the water in a ditch or marshy pool. So the Sun
God, as our ancestors in the Far East used to call him thousands of
years ago, not only gives us our food to eat, but keeps the air fit
for us to breathe.

In still another way the sun is one of our best friends; for his rays
have the wonderful power, not only of causing plants that supply us
with food--the Green Plants, as we call them--to grow and flourish,
but at the same time of withering and killing certain plants that do
us harm. These plants--the Colorless Plants, we may call them--are the
_molds_, the _fungi_, and the _bacteria_, or _germs_. You know how a
pair of boots put away in a dark, damp closet, or left down in the
cellar, will become covered all over with a coating of gray mold. Mold
grows rapidly in the dark. Just so, these other Colorless Plants,
which include most of our disease germs, grow and flourish in the
dark, and are killed by sunlight. That is why no house, or room, is
fit to live in, into which the sunlight does not pour freely sometime
during the day. The more sunlight you can bring into your bedrooms and
your playrooms and your schoolrooms, except during the heat of the day
in the summer time, the better they will be. The Italians have a very
shrewd and true old proverb about houses and light: "Where the
sunlight never comes, the doctor often does."

So you see that Nature is guiding you in the right direction when she
makes you love and delight in