Why does it beat too fast?--"Because it is hurrying to drive the alcohol out of the body."

In what other way do alcoholic liquors hurt the heart?--"They produce disease in it."

Tell one way by which the heart becomes diseased through alcoholic liquors?--"Alcohol softens the fibres of the muscles of the heart, and fills them with fat."

What harm does this do to the heart?--"It makes it too weak to do its work, which is to pump the blood through the body."

What sometimes happens when the heart is thus weakened?--"It stops beating, which causes sudden death."

What harm does alcohol do to the blood?--"It uses up the water of the blood; it destroys the goodness of the red part; it makes the blood thin, impure, and unfit to do its work." See Appendices on Alcohol and Tobacco.

[Ill.u.s.tration: THE LUNGS.]

1, 2, the larynx, the upper part of the windpipe.

3, the windpipe, or trachea.

4, where the windpipe divides to right and left lungs.

5, the right bronchial tube.

6, the left bronchial tube.

7, outline of the right lung.

8, outline of the left lung.

9, the left lung.

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 ma.s.s, through which the air cannot pa.s.s.

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, I must keep all parts of my body warm, I must not change my winter clothing too early in the spring, I must avoid draughts of cool air, I must not rush into the cold when I am in a perspiration, I must not poison my lungs with alcohol or tobacco.

QUESTIONS FOR THE FORMULA.

1. What are the lungs?

2. Describe the lungs.

3. How do you breathe?

4. Why can you not live without breathing?

5. What is necessary if you would have healthy lungs?

THE AIR AND THE LUNGS.

The air which enters through the nose and mouth pa.s.ses into a tube of muscles and ring-like pieces of cartilage. The upper part of this tube is the voice-box or _larynx_, covered by a spoon-shaped lid which closes when we swallow; the lower part is the _trachea_, and the two parts are the windpipe. The trachea divides into two branches, _the bronchial tubes_, one for each lung. These tubes divide again and again like the branches of a tree, and end in exceedingly small sacs or bags. The air in these sacs, or air-cells, gives _oxygen_ to the blood in the tiny blood-vessels of the lungs and takes from them the poison, _carbonic-acid gas_, water, and impurities, which it carries back through the windpipe into the outside air.

QUESTIONS ON THE LUNGS AND RESPIRATION.

Of what are the lungs composed?--"Of a soft, fleshy substance, full of small air-cells and tubes."

Of what use are the lungs?--"They are the breathing machines of the body."

How do the lungs appear when healthy?--"Porous and spongy."

How does the air get into the lungs?--"The air flows through the nose and mouth, into the windpipe and along the air-tubes, into the air-cells of the lungs."

What does the air do in the lungs?--"It swells the lungs and causes the chest to expand."

What do you mean by expand?--"To increase in size."

How is the air expelled from the lungs?--"The chest contracts and sends the impure air through the tubes and windpipe, the nose and mouth, into the atmosphere."

What do you mean by contracts?--"Becomes smaller."

What do you mean by atmosphere?--"The air."

Of what use is the air when it is in the lungs?--"It makes the blood pure."

Why can you not live without breathing?--"Because, if I do not breathe, pure air cannot get into the lungs to make the bad blood pure, and I cannot live if the dark, impure blood is sent back again through my body."

Why must you live in the sunlight?--"Because the sunlight helps to purify the blood and strengthen the body."

Why must you wear loose clothing?--"Because tight clothing stops the circulation of the blood."

Why must you avoid tight-lacing?--"Because tight-lacing crowds the ribs against the lungs, so that the lungs cannot move freely."

Why should you wear clean clothing?--"That nothing impure may pa.s.s into the body through the pores of the skin."

Why should you keep the body clean?--"That the pores of the skin may not be closed, but remain open to let the perspiration pa.s.s through."

What has the cleanliness of the body to do with the health of the lungs?--"If the body is not kept clean, the perspiratory pores become clogged."