of different things with oxygen. If oxygen ceased to
combine with the wood or gas or whatever fuel you use, that fuel could
not burn; how could it when "burning" _means_ combining with oxygen?
The heat in your body and the energy with which you move come entirely
from the burning (oxidation) of materials in your body; and that is
why you have to breathe; you need to get more and more oxygen into
your body all the time to combine with the carbon and hydrogen in the
cells of which your body is made. Plants breathe, too. They do not
need so much oxygen, since they do not keep warm and do not move
around; but each plant cell needs oxygen to live; there is burning
(oxidation) going on in every living cell. Fishes breathe oxygen
through their gills, absorbing the oxygen that is dissolved in the
water. They do not take the water apart to get some of the combined
oxygen from it; there is always some free oxygen dissolved in any
water that is open to the air. It is clear that fires would all go out
and everything would die if burning (combining with oxygen) stopped.

The reason things would not decay is that decay usually is a slow
kind of oxidation (burning). When it is not this, it is the action
of bacteria. But bacteria themselves could not live if they had _no_
oxygen; so they could not make things decay.

Not only would the dead plants and animals remain in good condition,
but the clothes people were wearing when they dropped dead would stay
unfaded and bright colored through all the storms and sunshine. And
the iron poles and car tracks and window bars would remain unrusted.
For bleaching and rusting are slow kinds of oxidation or burning
(combining with oxygen).

Here are two experiments which show that you cannot make things burn
unless you have oxygen to combine with them:

EXPERIMENT 94. Light a candle not more than 4 inches long and
stand it on the plate of the air pump. Cover it with the bell
jar and pump the air out. What happens to the flame?

EXPERIMENT 95. Fasten a piece of candle 3 or 4 inches long to
the bottom of a pan. Pour water into the pan until it is about
an inch deep. Light the candle. Turn an empty milk bottle
upside down over the candle. Watch the flame. Leave the bottle
over the candle until the bottle cools. Watch the water around
the bottom of the bottle. Lift the bottle partly out of the
water, keeping the mouth under water.

The bubbles that came out