13. What does its lining do?

14. What do the stomach and the gastric juice do to the food we have eaten?

15. How did anybody find out what the stomach could do?

16. Why must all the food we eat be changed?

17. Why do you need food?

18. Why do people who are not growing need food?

19. What does alcohol do to the gastric juice? to the stomach?

20. What is the use of the saliva?

21. How does the habit of spitting injure a person?

22. How does tobacco affect the teeth? the mouth?

23. How does the tobacco-user annoy other people?

FOOTNOTE:

[Footnote C: The food is partly prepared by the liver and some other organs.]

CHAPTER XI.

WHAT DOES THE BODY NEED FOR FOOD?

[Ill.u.s.tration: N]OW that you know how the body is fed, you must next learn what to feed it with; and what each part needs to make it grow and to keep it strong and well.

WATER.

A large part of your body is made of water. So you need, of course, to drink water, and to have it used in preparing your food.

Water comes from the clouds, and is stored up in cisterns or in springs in the ground. From these pipes are laid to lead the water to our houses.

Sometimes, men dig down until they reach a spring, and so make a well from which they can pump the water, or dip it out with a bucket.

Water that has been standing in lead pipes, may have some of the lead mixed with it. Such water would be very likely to poison you, if you drank it.

Impurities are almost sure to soak into a well if it is near a drain or a stable.

If you drink the water from such a well, you may be made very sick by it. It is better to go thirsty, until you can get good water.

A sufficient quant.i.ty of pure water to drink is just as important for us, as good food to eat.

We could not drink all the water that our bodies need. We take a large part of it in our food, in fruits and vegetables, and even in beefsteak and bread.

LIME.

Bones need lime. You remember the bone that was nothing but crumbling lime after it had been in the fire.

Where shall we get lime for our bones?

We can not eat lime; but the gra.s.s and the grains take it out of the earth. Then the cows eat the gra.s.s and turn it into milk, and in the milk we drink, we get some of the lime to feed our bones.

[Ill.u.s.tration: _Lime being prepared for our use._]

In the same way, the grain growing in the field takes up lime and other things that we need, but could not eat for ourselves. The lime that thus becomes a part of the grain, we get in our bread, oat-meal porridge, and other foods.

SALT.

Animals need salt, as children who live in the country know very well.

They have seen how eagerly the cows and the sheep lick up the salt that the farmer gives them.

Even wild cattle and buffaloes seek out places where there are salt springs, and go in great herds to get the salt.

We, too, need some salt mixed with our food. If we did not put it in, either when cooking, or afterward, we should still get a little in the food itself.

FLESH-MAKING FOODS.

Muscles are lean meat, that is flesh; so muscles need flesh-making foods. These are milk, and grains like wheat, corn and oats; also, meat and eggs. Most of these foods really come to us out of the ground. Meat and eggs are made from the grain, gra.s.s, and other vegetables that the cattle and hens eat.

FAT-MAKING FOODS.

We need cushions and wrappings of fat, here and there in our bodies, to keep us warm and make us comfortable. So we must have certain kinds of food that will make fat.

[Ill.u.s.tration: _Esquimaux catching walrus._]

There are right places and wrong places for fat, as well as for other things in this world. When alcohol puts fat into the muscles, that is fat badly made, and in the wrong place.

The good fat made for the parts of the body which need it, comes from fat-making foods.

In cold weather, we need more fatty food than we do in summer, just as in cold countries people need such food all the time.

The Esquimaux, who live in the lands of snow and ice, catch a great many walrus and seal, and eat a great deal of fat meat. You would not be well unless you ate some fat or b.u.t.ter or oil.

WHAT WILL MAKE FAT?