It takes about an hour for this kind of tonic to work with this particular boy, and the dose has to be given once in a while, just because his intelligent mother knows that tired neurons and crossness go together, and that resting the one will cure the other.

The same law holds good for other children, as also for grown people of every age. Let us bear this in mind, and act accordingly. When we are cross, knowing what has probably happened to our own neurons, let us give them rest. Let us remember that each of us is master of his own living machine; that we can keep it in order or put it out of order by the way we treat it; and that it will serve us well or not, according to the treatment it receives.

In 1907 Senator LaFollette was so sure that overtaxed neurons often explain railroad accidents, that he brought the subject to the attention of the Senate of the United States. He wished to show that engineers and flagmen often have to go too long without resting their neurons, and that human lives are endangered thereby. He cited case after case to prove this. I quote a few of these cases which he took from official reports.

1. Collision. Engineer dozing; seventeen hours on duty; only six hours' rest preceding his call to this service.

2. Collision. Train not under control. Hours on duty, forty-two.

3. Collision. Signal man went back to flag; fell asleep; twenty hours on service.

4. Collision. Engineer dozing; twenty hours on service.

5. Collision. Engineer mistaking signals; twentyseven hours on duty.

Each one of these collisions preaches the same sermon, and in every instance the text of the sermon is: "When the nuclei of the neurons are already shriveled by fatigue, it is perilous to tax them further; for overtaxed neurons cannot be trusted in responsible positions."

There are times, however, when something besides fatigue and long hours makes us sleepy. To save repeating on this subject, turn to the chapters on sleep in Good Health; the present chapter has only space enough for the reasons that explain those chapters.

Why does monotony put people to sleep? Why do we feel sleepy in certain large gatherings? The answer is easy. We are not interested in what is going on, and the brain does not exert itself; without exertion it calls for little blood; without blood it grows pale; a pale brain wants to sleep. We feel sleepy then because the brain lacks blood. But let something happen in the church where various people, young and old, are feeling sleepy. Let a dog run up the aisle, or let a woman faint in the next pew; let anything be done that will compel the brain to call for blood, and sleepiness vanishes in an instant.

Impure air encourages drowsiness, but the speaker who can keep the brain of his hearer active will keep it awake in spite of the air.

A sleepy boy is trying to keep awake in a quiet room, when suddenly his excited brother and sister rush in, eyes sparkling, cheeks glowing, tongues moving fast, and in no time that sleepy boy is as wide-awake as they are. Why? Simply because the talking children set his brain to thinking; thinking meant exercise; exercise meant more blood to the brain, and no one sleeps easily in that condition.

It is, indeed, just because of this that we find people at the other extreme of perplexity. They cannot sleep. For them every device is necessary to drive blood out of the brain-a noiseless room, comfortable bed, pillow of the right size, fresh air, and a mind free from worry of every sort. The following rules may also help.

1. Enough exercise by day to secure muscular fatigue by bedtime.

2. A restful evening without mental work or excitement.

3. A hot foot bath, or a hot-water bag at the feet to increase the flow of blood in that direction.

4. A cold-water bag on the head to decrease the call for blood up there.

5. A hot bath, lasting a few moments, to draw blood to the skin.

6. A cracker or two eaten to compel the stomach to call to it some of the superfluous blood from the brain.

7. Monotonous thoughts and sounds.

To explain several of these points we must remember that we may reduce the amount of blood at one part of the body by doing that which will make it go elsewhere.

Good Health shows the need of monotony, and now we discover the reason for it. Quietness and monotony subdue the active brain and drive the blood away. Anything, therefore, that requires little thought—anything that keeps the mind from traveling at a brisk pace to the ends of the earth and back again-is a move in the right direction.

Perhaps each person must discover his own road to the blessed land of sleep. I discovered mine long ago quite by accident. And this is the way I travel upon it. I close my eyes and tell my eyeballs to stand firm, not allowing themselves to move from side to side as eyeballs are apt to do on their way to sleep. With my eyelids down, I then look straight ahead into space. I know that if I am patient I shall soon see some unexpected, lovely picture. I have no notion as to what the picture will be, but I know that something will come, and I wait with expectation for it.

Soon there seems to be a clearing in the darkness, as if I looked into an open, white sky, and the clouds roll

away in spots. Sometimes I see no large space, but only a bright point which moves across the range of my vision. I continue to gaze steadily, for it is in this open space that the picture will appear. Then suddenly I see it the side of a rustic house covered with roses, or a slender waterfall ending in spray, or a great stretch of ocean ending in sky.

The picture is always simple and small and it passes away quickly; but in connection with it comes my sleep. And that is the discovery. While I am holding my gaze steady, while I am waiting — sometimes before the first picture arrives, sometimes after I have seen one or two-suddenly, without a moment of warning, I am fast asleep.

This, then, is my path to the land of dreams. But whatever the road we take, our neurons are not wholly inactive while we tarry in that land. Some birds sleep standing on one leg; I have seen them do it. It is neurons that take care of the lifted leg and see that it stays up. There are soldiers who sleep as they march. There are children who talk in their sleep. I know a woman who sang once as she slept. And none of these acts could take place without commands from the neurons.

Other neurons never rest. Through their help heart and lungs, stomach and sweat glands, liver, and all the other organs of the body work as well when we are asleep as when we lie awake or walk about.