Chapter I: Keeping Well

How many times have you been absent this term? No oftener than you were obliged to be, I am sure; for it's almost as bad as being "put in Coventry" to come back and hear about the good time the rest of the class have been having, and feel that you "weren't in it." Of course, sometimes, when you are not well, you have to be absent; it is best that you should be. But it is better still to know how to keep well, so you won't have to be absent, and won't have to miss any good times in work or play all your life.

You remember that all the parts of your body are fed and ventilated by the blood, which is pumped to them from the heart. So long as this blood is pure and has plenty of oxygen in it, it does good to every part of the body to which it comes. But the moment that poisons and dirt and waste begin to pile up in the blood, then the blood that comes to the different parts of the body may be poisonous to them, instead of helpful.

Such poisons in the blood are particularly harmful to the nerves and the brain, because these are among the most delicate and sensitive of all the structures in the body.

Often we think of the body as a beautiful house. Now a house does not look very beautiful when it has dust and crumbs on the floor, buckets of greasy dishwater in the kitchen, and smoke from the furnace in the air! You could not live in such a place. No, the smoke must go out up the chimney, the dust and crumbs must be swept away, the dirty water must be drained off in pipes; the house must be not only cleaned, but kept clean all the time. This is true of your body, too.

Now Mother Nature sends the smoke from the body out through the lungs, and the crumbs and solid dirt down and out by means of the food tube. But the waste water--how does she get rid of that? The waste water, you remember, is in the blood vessels, mixed with the blood. How does she get it out of the blood? She sends it through three magic cleaners, or strainers,--the _skin_, the _liver_, the _kidneys_.

That the skin is a strainer, you already know; for you know how the skin lets out the waste water in perspiration, or sweat, and how important it is that we keep the little holes of the strainer open and clean. And you know, too, that most of the water that passes out of the body goes first to the kidneys.

The liver, however, is the largest cleaning machine of all and has to work very hard. The blood comes to it full of foods and poisons. This wonderful cleaner picks out the food it needs and takes up many of the poisons, too. "What does it do with the poisons?" you ask. Some of them it changes into good food, and others it makes harmless and sends away down the food tube in a fluid called _bile_. If we are strong and healthy, the liver has the power to kill many of the disease germs that get into the body. That is why sometimes, when you have had a chance to take mumps or grippe or some other "catching" disease, you don't take it. Your liver kills the germs, or seeds. See how carefully Mother Nature has planned that we may be clean inside as well as outside.

Compare this with the diagram on page 26, and see how the liver
partly overlaps the stomach.]

But you must not over-work your liver. If you do, it may become too tired to do anything at all. Then all these poisons will spread through the body; the skin and the whites of the eyes will grow yellow, and you will be what is called "bilious." When this happens, the poisons go to your brain, too, and make you feel sad; your tongue looks white instead of pink, and you have a disagreeable taste in your mouth. Your happiness depends very much on your liver.

"How shall I keep my liver rested and in good working order?" By eating only sound, wholesome, pure food, and avoiding dirty milk; by going to the toilet regularly every morning after breakfast; by keeping your windows open and avoiding the poisons and disease germs in foul air. Then, if you run and play and work out of doors, so that the muscles move a great deal and you breathe in plenty of oxygen to keep the body fires burning briskly, that will help a great deal.

Last summer up in the mountains I saw a big log close by the path. It had been sawed across so that the end was smooth. It was brown and weather-stained, so of course I knew that it had lain there a long time. How surprised I was to see a pile of fine fresh sawdust on the ground beside it. As I came nearer, I saw piece after piece of sawdust dropping, dropping, dropping, one after the other, from a hole in the log. I looked into the hole, and what do you think I saw? Hundreds of little brown ants, busy as could be carrying the sawdust, throwing it out, and then scurrying back to get some more. Several feet inside the log, other ants were cutting the sawdust, hollowing out the rooms of their house; and in another part others were getting food for the workers, and still others taking care of the baby ants. They were all helping one another, and whatever one ant did helped all the rest. That is the way with the parts, or organs, of the body. When one part works well, it helps all the rest; when one squad of tiny cells in the muscles or liver or heart is doing its duty, like the little ants, it helps all the other cell-workers in the body to keep healthy.

If you eat proper food, you help not only your stomach but your liver, too; for it has not so many poisons to get rid of. While you are helping your stomach and your liver, you are helping your heart and your brain, and so on. So what you do to help one helps all.

There are, however, some poisons that the liver cannot get rid of; but these the skin or the kidneys carry away. Have you ever seen kidney beans? The bean is the shape of a kidney. The kidneys are in the middle of your back, packed close to your backbone, on a line with your waist. This is a picture of them. Do you see the little tubes leading down from the kidneys, carrying the waste water and poison down into a kind of bag? The walls of this bag, called the _bladder_, will stretch, and it will hold about a pint of waste water. From the bladder a tube carries the water down out of the body.

The large tubes are the artery and the vein that carry blood to
and from this part of the body.]

You can help your kidney-strainers by emptying your bladder at certain times each day. Some children have to empty the bladder much oftener than others, but most children can form what we call _regular habits_ about it, by trying to do it at the same times each day. If you are quite strong, five times a day is often enough: when you first get up, at recess, at noon, at four o'clock, and at bedtime. Many children do it much oftener than this; but as they grow older and the muscles grow stronger, they slowly outgrow this trouble, if they try to form the right habits.

There are many diseases of the kidneys; for, like the liver, they are sometimes over-worked and do not carry the poisons from the body. You are helping your kidneys when you drink plenty of fresh clean water every day, and also when you play or work hard enough to get into a good perspiration; for, as perspiring carries out some of the poisons, it leaves less for the kidneys to pour out. You ought to get into a good perspiration at least once every day, or better, three or four times, if you wish to keep healthy. The Bible says, "In the sweat of thy brow shalt thou eat bread"; and you must earn health and happiness at the same price.