CHAPTER XIII.
WHY AND HOW WE BREATHE.
~1.

An Experiment.~--Let us perform a little experiment.

We must have a small bit of candle, a fruit jar, or a bottle with a large mouth, and a piece of wire about a foot long.

Let us notice carefully what we are about to do and what happens.
~2.~ We will fasten the candle to the end of the wire.

Now we will light it, and next we will let it down to the bottom of the jar.