10, the right lung.

* * * * *

PART IX.

FORMULA FOR THE LESSON ON THE LUNGS AND RESPIRATION.

1. My lungs are the bellows or breathing machines of my body.

2. They are composed of a soft, fleshy substance, full of small air-cells
and tubes. They are porous and spongy when healthy, but in some diseases
become an almost solid mass, through which the air cannot pass.

3. I breathe by drawing the air through my windpipe, along the tubes into
the cells of my lungs, swelling them out, and causing my chest to expand;
then the chest contracts, and the impure vapor in my lungs is pressed out
through the same tubes, windpipe, nose, and mouth, into the atmosphere.

4. I cannot live without breathing, because if the air does not go down
into my lungs, the dark blood in them is not changed into pure red blood,
and goes back through my body dark blood, which cannot keep me alive.

5. If I would have healthy lungs,
I must breathe pure air,
I must live in the sunlight,
I must keep my body clean,
I must wear loose clothing,
I must wear clean clothing,
I must sit and stand erect,