his makes the water very much purer, but it is not so certain to make
the water safe as is boiling it. Bad water makes nearly a quarter of a
million of our people sick every year and kills twenty thousand of them.

=How much Food does the Body Need?=--Most people eat too much.
Overeating overworks the stomach, poisons the body, makes one feel
lazy, and causes headache. If you chew your food fine and stop eating
as soon as hunger is satisfied without tempting the appetite with
sweets, you are not likely to overeat.

About one seventh of a pound of building food is needed daily to keep
the body in repair, and a quarter of a pound of fat and a pound of
starches and sugars are required to help the body do a hard day's
work. A half pound of bread, beans, and meat each, a pound of
potatoes, a pint of milk, and a quarter of a pound of butter and sugar
each, will give a working man all the food he needs for a day.

[Illustration: FIG. 10.--Bird's-eye view of Plymouth, Pennsylvania,
showing where the waste from one sick room was thrown on the bank of a
stream which several miles below supplied the town with water and
caused over one thousand cases of fever and more than a hundred deaths
within seven weeks.]

=Beer and Wine as Foods.=--It was once thought that beer and wine were
good foods, but hundreds of late experiments show that these drinks
are very poor and expensive foods. A half glass of milk is of more use
to the body as a food than a full quart of beer. The use of much wine
or beer may seem to satisfy the appetite because they deaden the real
feeling of hunger. Neither of these drinks can be used by the young
without danger of doing much harm.

[Illustration: FIG. 11.--The little glass of milk contains nearly twice
as much food for building flesh and blood as the large glass of beer.]

PRACTICAL QUESTIONS

1. Why does the body need food?

2. Why do you weigh less after working?

3. What is oxygen?

4. From what do we get body-building foods?

5. In what is starch found?

6. How much water does the body need?

7. Where have people been made sick by using bad water?

8. How can we prevent sickness from bad water?

9. What harm does overeating do?

10. What can you say of beer as a food?

CHAPTER IV

FOOD AND HEALTH

=Meats.=--Beef is the best of all meat for food. Nearly one fifth of
it can be used to repair the worn-out parts of the body.