We have two pa.s.sages leading down our throats. One is to the lungs, for breathing; the other, to the stomach, for swallowing.

Do you wonder why the food does not sometimes go down the wrong way?

The windpipe leading to the lungs is in front of the other tube. It has at its top a little trap-door. This opens when we breathe and shuts when we swallow, so that the food slips over it safely into the pa.s.sage behind, which leads to the stomach.

If you try to speak while you have food in your mouth, this little door has to open, and some bit of food may slip in. The windpipe will not pa.s.s it to the lungs, but tries to force it back. Then we say the food chokes us. If the windpipe can not succeed in forcing back the food, the person will die.

HOW THE FOOD IS CARRIED THROUGH THE BODY.

But we will suppose that the food of our dinner has gone safely down into the stomach. There the stomach works it over, and mixes in gastric juice, until it is all a gray fluid.

Now it is ready to go into the intestines,--a long, coiled tube which leads out of the stomach,--from which the prepared food is taken into the blood.

The blood carries it to the heart. The heart pumps it out with the blood into the lungs, and then all through the body, to make bone, and muscle, and skin, and hair, and eyes, and brain.

Besides feeding all these parts, this dinner can help to mend any parts that may be broken.

Suppose a boy should break one of the bones of his arm, how could it be mended?

If you should bind together the two parts of a broken stick and leave them a while, do you think they would grow together?

No, indeed!

But the doctor could carefully bind together the ends of the broken bone in the boy's arm and leave it for awhile, and the blood would bring it bone food every day, until it had grown together again.

So a dinner can both make and mend the different parts of the body.

REVIEW QUESTIONS.

1. What shall we have for dinner?

2. What is the first thing to do to our food?

3. Why do we cook meat and vegetables?

4. Why do not ripe fruits need cooking?

5. What is said about a good cook?

6. What is the first thing to do after taking the food into your mouth?

7. Why must you chew it?

8. What does the saliva do to the food?

9. How can you prove that saliva turns starch into sugar?

10. What happens if the food is not chewed and mixed with the saliva?

11. What comes next to the chewing?

12. What is there wonderful about swallowing?

13. What must you be careful about, when you are swallowing?

14. What happens to the food after it is swallowed?

15. How is it changed in the stomach?

16. What carries the food to every part of the body?

17. How can food mend a bone?

CHAPTER XIII.

STRENGTH.

[Ill.u.s.tration: H]ERE are the names of some of the different kinds of food. If you write them on the blackboard or on your slates, it will help you to remember them.

_Water._ _Salt._ _Lime._

Meat, } Sugar, } Milk, } Starch, } Eggs, } Fat, } for fat and heat.

Wheat, } for muscles. Cream, } Corn, } Oil, } Oats, }

Perhaps some of you noticed that we had no wine, beer, nor any drink that had alcohol in it, on our bill of fare for dinner. We had no cigars, either, to be smoked after dinner. If these are good things, we ought to have had them. Why did we leave them out?

_We should eat in order to grow strong and keep strong._

STRENGTH OF BODY.

If you wanted to measure your strength, one way of doing so would be to fasten a heavy weight to one end of a rope and pa.s.s the rope over a pulley. Then you might take hold at the other end of the rope and pull as hard and steadily as you could, marking the place to which you raised the weight. By trying this once a week, or once a month, you could tell by the marks, whether you were gaining strength.

But how can we gain strength?

We must exercise in the open air, and take pure air into our lungs to help purify our blood, and plenty of exercise to make our muscles grow.

We must eat good and simple food, that the blood may have supplies to take to every part of the body.

ALCOHOL AND STRENGTH.