e some of the most useful organs of the body.

This box is divided across the middle by a strong muscle, so that we may
say it is two stories high.

The upper room is called the chest; the lower one, the abdomen ([)a]b
d[=o]'m[)e]n).

In the chest, are the heart and the lungs.

In the abdomen, are the stomach, the liver, and some other organs.

THE STOMACH.

The stomach is a strong bag, as wonderful a bag as could be made, you
will say, when I tell you what it can do.

The outside is made of muscles; the lining prepares a juice called
gastric (g[)a]s'tr[)i]k) juice, and keeps it always ready for use.

Now, what would you think if a man could put into a bag, beef, and
apples, and potatoes, and bread and milk, and sugar, and salt, tie up
the bag and lay it away on a shelf for a few hours, and then show you
that the beef had disappeared, so had the apples, so had the potatoes,
the bread and milk, sugar, and salt, and the bag was filled only with a
thin, grayish fluid? Would you not call it a magical bag?

Now, your stomach and mine are just such magical bags.

We put in our breakfasts, dinners, and suppers; and, after a few hours,
they are changed. The gastric juice has been mixed with them. The strong
muscles that form the outside of the stomach have been squeezing the
food, rolling it about, and mixing it together, until it has all been
changed to a thin, grayish fluid.

HOW DOES ANYBODY KNOW THIS?

A soldier was once shot in the side in such a way that when the wound
healed, it left an opening with a piece of loose skin over it, like a
little door leading into his stomach.

A doctor who wished to learn about the stomach, hired him for a servant
and used to study him every day.

He would push aside the little flap of skin and put into the stomach any
kind of food that he pleased, and then watch to see what happened to it.

In this way, he learned a great deal and wrote it down, so that other
people might know, too. In other ways, also, which it would take too
long to tell you here, doctors have learned how these magical food-bags
take care of our food.

WHY DOES THE FOOD NEED TO BE CHANGED?

Your mamma tells you sometimes at breakfast that you must eat oat-meal
and milk to make you grow into a big man or woman.

Did you ever wonder what part of you is made of oat-meal, or what part
of milk?

That stout little arm does not look like oat-meal; those rosy cheeks do
not look like milk.

If our