"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.

[Ill.u.s.tration: THE KIDNEYS AND THE BLADDER

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.

II. SOME FOES TO FIGHT

You have seen that sitting or sleeping in rooms where the air is bad, or eating the wrong kind of food, or working after you are badly tired, will poison your blood and hinder the proper working of that beautiful machine, your body. These poisons are made inside your body, and you can prevent them by living healthfully and wholesomely. But there are other poisons, which may get into the blood from outside the body; and while it is best for you not to think too much about these, or to worry over dangers that may never come, yet it is well to know just enough about some of them to be able to keep out of their way, as far as possible.

The most dangerous form of poisons from outside the body are those made by the germs of some rather common diseases, which, because you can "catch" them from some one else who has them, are called "catching," or _infectious_, or _contagious_.

Some of the germs of these "catching" diseases, like the germs of typhoid fever, of which we have spoken in connection with our drinking water, are carried in the water or milk that we drink, or upon the food that we eat; and one of the worst carriers of germs is the ordinary household fly.

Not so very many years ago, people did not know that _dirt makes people sick_. You see, they did not know anything about the disease seeds (germs) that grow so fast in dirt. They did not like to have flies about, because flies look so dirty and bite people and crawl over things and spot them. But nowadays, we will not have flies about because we know that they have been in dirty places where disease germs live, and that one little fly can carry thousands and thousands of these germs on his feet.

Have you ever looked at a fly through a magnifying gla.s.s or under a microscope? If you haven't, try it sometime. You will see that his legs are covered with little hairs; and it is on these little hairs that the germs lodge. They are too small for you to see except with a very powerful gla.s.s; but scientists have proved that they are there, and they have found that there are always typhoid germs among them.

[Ill.u.s.tration: THE COMMON HOUSE FLY

As he appears through a magnifying gla.s.s.]

Did you ever see a fly wipe his feet before he came into the house?

No, indeed; and he goes anywhere he pleases, over the bread and into the cream. Yet he was born in dirt and bred in dirt, and he lives in dirty places all the time he is not crawling over your clean things and spoiling them.

Flies are hatched from eggs; and these eggs can hatch only in piles of dirt, such as heaps of manure, or places where garbage and sc.r.a.ps from the house are dumped or thrown. We call the common fly the "domestic"

or "house" fly, because he lives only in the neighborhood of houses and barnyards where heaps of manure and piles of dirt are allowed to gather.

When the fly first hatches from the egg, it is a little white, wriggling worm called a _maggot_, like those that some of you may have seen in decaying meat or fish or cheese. The maggots must have decaying substances to eat and live upon while they are growing, and this is why the eggs are laid in manure heaps and garbage piles.

[Ill.u.s.tration: A MAGGOT HATCHING FROM THE EGG

(Greatly magnified.)]

It takes the maggot about five days to grow to its full size, and then it turns into a _chrysalis_. That is, it is shut up in a kind of case that it has spun for itself, like the coc.o.o.n of the silkworm or the caterpillar. In about five days more it breaks out of this coc.o.o.n and appears as a fly with wings.

So, you see, the eggs must stay in that manure heap about two weeks if they are to hatch. If, within that time, the manure is carted away and thrown out somewhere where it will dry, the little unhatched flies will be killed, or prevented from hatching. All we have to do, then, to be entirely rid of flies about our houses is to see that the heaps of manure and all piles of cans and garbage are taken away at least once a week.

[Ill.u.s.tration: FLY MAGGOTS ON OLD NEWSPAPER

Note the size of the maggot compared with the newspaper type.]

If manure heaps or piles of dirt cannot, for any reason, be carried away as often as this, then they can be sprinkled with something that is poisonous to flies, such as a.r.s.enic or kerosene. This will kill the maggots. If we keep every kind of waste and sc.r.a.ps from the house, and all the manure from the barn and the pig-pen and the hen-house carefully cleaned up, or sprinkled with some poison, we shall get rid of flies entirely and never need to use screens at the doors and windows. Until we do this, it is best to put screens at the doors and windows in the summer time, and particularly to screen carefully any place where food is kept or cooked; for we know that a great many cases of typhoid and of other diseases of the stomach and bowels, such as _summer sickness_, or summer _diarrhea_, and _cholera morbus_, are carried to our food by the dirty feet of flies.

Many of the germs of "catching" diseases--most of them, in fact--are carried in the air, in scales that have rubbed off the skin of the persons sick with them, or in spray that they have coughed into the air, or in saliva that they have spit upon the floor.

There is one sickness of this kind that I ought to tell you about, because it kills so many thousand people here in our own country every year. We sometimes call it the "Great White Plague." Its common name is _consumption_, and the doctors call it _tuberculosis_. I dare say you have heard of it and wondered what it meant.

A few years ago people thought it could not be cured. They thought that children had it because their parents had had it before them. But now, the cheering thing about it is that we have found that Mother Nature herself can cure it with fresh air and sunshine and wholesome food. We have found, too, that people catch it from others who are sick with it, and need not have it just because their parents did.

[Ill.u.s.tration: FRESH AIR AND SUNLIGHT ARE GOOD DOCTORS]

This means, then, that thousands of people who have it need not die, but can be cured simply by living and sleeping out of doors and eating plenty of milk, eggs, and meat, nuts and fruit. There are camps for them in almost every state in the Union now. The fresh air gives them such a big appet.i.te that they can eat more than most healthy people, and they soon get strong and well.

If all the people who now have consumption were taken out into the country and cured, there would be no one left for the rest of us to catch it from, and the disease would soon die. Some day our Boards of Health will decide to do this, and then consumption will become as rare as smallpox is now, and will kill only a few hundred people a year in the United States instead of 150,000 every year, as it does now.

People and governments are giving great sums of money, not only to cure the people who now have consumption, but to do something towards stopping the disease by keeping things so clean and people so strong that no one will ever have it. Even little children can help to fight and kill this "Great White Plague," and I'll tell you how.

We know that, when people have consumption in their lungs, what they cough and spit out of their mouths and blow out of their noses (we call it _sputum_) has the germs, or seeds, of the disease in it. So, to keep other people from catching the disease, they must hold something before the face when they cough, and they must catch the sputum in paper (newspapers or paper napkins are very good for this) and burn it, for burning kills the germs. Then, too, they must not kiss other people on the mouth, and others must not kiss them. They must use their own drinking-cups, and never lend or borrow a cup. You see, you can look out for these things, yourselves. When grown people kiss you, just turn your cheek to them, instead of your mouth. Your cheek will not carry anything to your windpipe and lungs. And be sure to carry your own drinking-cup, or, better still, make the one for which you already have the pattern, every time you need one.

[Ill.u.s.tration: HIS OWN CUP AND TOWEL]

This sounds easy enough; and it is, too. But sometimes people don't know when they have this "plague," and of course they do not feel that they must be careful. What is to be done, then?

If people won't take care of themselves, then the government has to make health laws to protect them, and the health officers have to see that the laws are obeyed. In many of the states and cities, laws have been made so that n.o.body is allowed to spit on the sidewalk or in the cars or in any other public place; and common drinking-cups are forbidden at all park fountains and at the water-coolers in schools and trains and stations and other public places.

You ought to know about these things, because, as I have just said, other sicknesses, too, are carried about in the nose and mouth.

_Grippe_, _pneumonia_ or lung fever, and what we call _colds_ are caught in exactly the same way. We used to think we caught them by being chilled; but we are much more likely to take them by being shut up in a hot, stuffy room with other people who already have them.

Mother Nature never gave us such things in her beautiful, clean outdoors. We must wear clothes enough to keep us warm when we go out, and have bedclothes enough to keep us warm while we sleep; but we need not be afraid of catching any sickness from the clean outside air, either by day or by night. Drafts are not dangerous, except when our blood is already full of poisons and germs from foul air.

Of course it is foolish even for strong, healthy people to run any risks that can be avoided, and there is one other thing that you should keep on the watch against doing; and that is, touching or kissing or playing with other children who may be sick. It is better not even to sit in the same room with them if you can avoid it.

Many of the infectious diseases--and nearly three fourths of all the diseases that children have are infectious--are caught, as we have seen, from germs that are carried in the air. That is one reason why so many infectious diseases are likely to begin with running at the nose, or sneezing, or cold in the head, or sore throat. The germs, having been breathed in with the air, catch on the sides of the nostrils or at the back of the throat, and start inflammation and soreness wherever they land. This is just the way that _measles_, _scarlet fever_, _chicken pox_, _whooping cough_, and _diphtheria_ begin. Nearly all colds in the head, and sore throats with coughing, are infectious; so the best thing to do whenever you have a bad cold in the head, or a sore throat, is to keep out in the open air as much as you can, until it is better. Of course, a cold is not such a serious thing in itself; but, if it is neglected, it may lead to some very dangerous troubles, particularly to inflammation of the lungs, and sometimes even of the kidneys or the liver or the heart. Several of these infectious diseases--measles, chicken pox, and scarlet fever, for instance--have a rash, or breaking-out, called an _eruption_, upon the skin. This is another thing easy to look out for; and if you see anyone with a rash upon his face and hands, it is a good thing to keep away from him and not let him touch you. Even if he should not have measles or scarlet fever or chicken pox, but only a disease of the skin itself, he still might spread the infection of that; for most diseases that cause a breaking-out upon the surface of the skin are infectious.

Some of these infectious diseases are so common among children that they are called _Children's Diseases_, or the _Diseases of Infancy_, just as if it were natural for you to have them while you are children, and as if they were something that you have to have as a matter of course, before you grow up.

But it isn't necessary at all to have them, if you will take care of yourselves and help your doctors and the Board of Health of your county or town or city to prevent their spreading. These diseases, although usually very mild, never do anyone any good whatever, and may do serious harm; for their poisons may stay in the blood and injure the heart or the kidneys or the nerves.

One thing I should like to urge you to do if you happen to get one of these "children's diseases"; and that is, to stay in bed or out of school or away from work just as long as your doctor tells you to.

This is important, because it is very dangerous indeed to become over-tired or overheated or chilled, or to get your feet wet or romp too hard or sit up too late, before you have fully recovered; and you will not have fully recovered until at least three or four weeks after you are able to be out of bed. But if you take good care of yourselves for three or four weeks after measles or chicken pox or whooping cough or a very bad cold, you will avoid almost all danger of their poisons injuring your heart or kidneys or nerves, and causing chronic diseases, like Bright's disease or heart disease, later in life.

Perhaps now I have told you enough about poisons and sickness. You must not be frightened about them. I have told you these things so that you may understand why you must bathe, and brush your teeth, and wash your face and hands, and wear clean clothes, and breathe fresh air, and keep your windows open, and play out of doors--in fact, keep your bodies clean inside and out. I know you will be glad enough to do these things, troublesome though some of them may be, if you know the reason why. The best of it is that when you keep perfectly clean and healthy, not even the "Great White Plague" and cold seeds, or germs, can hurt you, even though they get into your mouth or nose; for Mother Nature gives healthy bodies the power to kill germs, and quite without our knowing it.

[Ill.u.s.tration: ENJOYING "ALL OUTDOORS"

Very discouraging to disease germs!]