people often grow very fleshy from drinking beer, because it contains alcohol, as you will soon learn. But they can not work any better on account of having this fat. They are not really any stronger for it.

REVIEW QUESTIONS.

CHAPTER III.

NERVES.

You have all seen the telegraph wires, by which messages are sent from one town to another, all over the country.

You are too young to understand how this is done, but you each have something inside of you, by which you are sending messages almost every minute while you are awake.

We will try to learn a little about its wonderful way of working.

In your head is your brain. It is the part of you which thinks.

As you would be very badly off if you could not think, the brain is your most precious part, and you have a strong box made of bone to keep it in.

Diagram of the nervous system.

We will call the brain the central telegraph office. Little white cords, called nerves, connect the brain with the rest of the body.

A large cord called the spinal cord, lies safely in a bony case made by the spine, and many nerves branch off from this.

If you put your finger on a hot stove, in an instant a message goes on the nerve telegraph to the brain. It tells that wise thinking part that your finger will burn, if it stays on the stove.

In another instant, the brain sends back a message to the muscles that move that finger, saying: "Contract quickly, bend the joint, and take that poor finger away so that it will not be burned."

You can hardly believe that there was time for all this sending of messages; for as soon as you felt the hot stove, you pulled your finger away. But you really could not have pulled it away, unless the brain had sent word to the muscles to do it.

Now, you know what we mean when we say, "As quick as thought." Surely nothing could be quicker.

You see that the brain has a great deal of work to do, for it has to send so many orders.

There are some muscles which are moving quietly and steadily all the time, though we take no notice of the motion.

You do not have to think about breathing, and yet the muscles work all the time, moving your chest.

If we had