This change in size is very simply but ingeniously carried out by two sets of tiny muscles. One set of these muscles runs in a ring right around the pupil; and when they shorten, the opening is contracted or narrowed. The other set runs outward through the iris like the spokes of a wheel; and when they shorten, they pull the pupil open. If anyone has had "drops" (atropin) put into his eyes in order to have them fitted with glasses, he will know what a disagreeably dazzling thing it is to have the pupil permanently enlarged, so that it cannot contract in a bright light.



CHAPTER XXIV

THE SPEECH ORGANS

The Voice, a Waste Product. It is one of the most curious things in this body of ours that what we regard as its most wonderful power and gift, the voice, is, in one sense, a waste product. So ingenious is nature that she has actually made that marvelous musical instrument—the human voice—with its range, its flexibility, and its powers of expression, out of spent breath, or used-up air, which has done its work in the lungs and is being driven off to get rid of it. It is like using the waste from a kitchen sink to turn a mill.

The organs that make the human voice were never built for that purpose in the first place. Unlike the eye and the ear, nature built no special organ for the voice alone, but simply utilized the windpipe and lung-bellows, the swallowing parts of the food passage (tongue, lips, and palate) and the nose, for that purpose, long after they had taken their own particular shapes for their own special ends.

The important point about this is that a good voice requires not merely a large and well-developed "music box" in the windpipe, but good lungs, a well-shaped healthy throat, properly arched jaws,—which mean good, sound teeth,—clear and healthy nasal passages, and a flexible elastic tongue. Of course, the blood and the nerves supplying all these structures must be in good condition, as well. So practically, a good voice requires that the whole body should be healthy; and whatever we do to improve the condition of our nose, our teeth, our throat, our lungs, our digestion, and our circulation will help to improve the possibilities of our voice. There are, of course, many exceptions; but you will generally find that great singers have not only splendid lungs and large vocal cords, but good hearts, vigorous constitutions, and bodies above the average in both stature and strength.

How the Voice is Produced. The chief parts of the breathing machine that nature has made over for talking purposes are the windpipe, or air tube, and the muscles in its walls. In the neck, about three inches above the collar bone, four or five of the rings of cartilage, or gristle,—which, you remember, give stiffening to the windpipe,—have grown together and enlarged to form a voice box, or larynx.



The upper edge of this voice box forms the projection in the front of the throat known by the rather absurd name of the "Adam's apple." This grows larger in proportion to the heaviness of the sounds to be made, and hence is larger in men than in women and boys. When the boy's voice box begins to grow to the man's in shape and size, his voice is likely to "break"; for it is changing from the high, clear boy's voice to the heavy, deep voice of the man.

Inside of this voice box, one of the rings of muscle that run around the windpipe has stretched into a pair of straight, elastic bands, or strings, one on each side of the air pipe, known as the vocal cords, or voice bands. These are so arranged that they can be stretched and relaxed by little muscles; and, when thrown into vibration by the air rushing through the voice box, they produce the sounds that we call talking or singing. The more tightly they are stretched, the higher and shriller are the tones they produce; and the more they are slackened, or relaxed, the deeper and more rumbling are the tones.

This is why, when you try to sing a high note, you can feel something tightening and straining in your throat, until finally you can stretch it no tighter, and your voice "breaks," as you say, into a scream or cry.

All musical instruments that have strings, are played, or produce their sounds, upon this same principle. The thinner and shorter the string, or the more tightly it is stretched, the higher the note; the heavier and longer the string, the lower the note. But no musical instrument ever yet invented can equal the human voice in the music of its tones, in its range, in the different variety and quality of tones it can produce, and in its wonderful power of expression. The human voice is a combination of reed organ, pipe organ, trumpet, and violin; and can produce in its tiny music box—only about two inches long by one inch wide—all the tones and qualities of tones that can be produced on all these instruments, except that it cannot go quite so high or so low.

All the musical instruments in the world, from the penny whistle to the grand piano, are but poor imitations of the human music box. The bellows, of course, of the human pipe organ are the lungs; while the tongue furnishes the stops; and the throat, mouth, and nose, the resonance, or sounding, chambers.

Just as a violin, or guitar, has two main parts,—a string, which vibrates and makes the sound; and a box, or hollow body, which catches that sound and enlarges it and gives it sweetness and vibration and quality,—so the human voice has two similar parts—the vocal bands, which make the sound; and a sound box, or rather series of three resonance boxes,—the throat, the mouth, and the nasal passages,—which enlarge and soften it and improve its quality.

You would naturally think that the strings, or cords, were the most important part both of the voice and of a musical instrument; and in one sense they are, as it could make no noise at all without them. But in another sense, far more important are the sounding boxes, or resonance chambers. The whole quality and value, for instance, of a Stradivarius[32] violin, which will make it readily bring ten thousand dollars in the open market, are due to the skill with which the body, or sound box, was made; the quality of the wood used; and, odd as it may seem, even the varnish used on it—the strings are the same as on any five-dollar fiddle. This is almost equally true of the human voice. While its size, or volume, is determined by the voice box and vocal bands, and its power largely by the lungs and chest, its musical quality, its color, and its expression are given almost entirely by the throat, mouth (including the lips), and nose. The proper management of these parts is two-thirds of voice training, and all these are largely under our control.

How a Good Voice may be Developed. If the nasal passages, for instance, are blocked by a bad cold or a catarrh or adenoids, then nearly half the body of your violin is blocked up and deadened; half your resonance chamber is destroyed, and the voice sounds flat and dead and nasal. If, on the other hand, your throat be swollen, or blocked, as by enlarged tonsils or chronic sore throat, then this part of the resonance chamber is muffled and spoiled, and your voice will be either entirely gone or hoarse; though perhaps by driving it very hard you may be able to make a clear tone.

If you have an attack of inflammation or cold further down, and the vocal bands swell, or the mucous membrane lining the voice box becomes inflamed and thickened, then the voice is lost entirely, just as the tone of a violin would be if a wet cloth were thrown across the strings. But disturbances in the voice box, or larynx, cause only a very small percentage of husky, poor, or unmusical voices.

A far commoner cause, indeed probably the commonest single cause of a poor, squeaky, or drawling, unmusical voice is careless and improper management of the mouth and lips. In the first place, you can easily show that such marked differences in sound as those of the different vowels are all produced by the mouth and lips. If you will prepare to say the vowels—a, e, i, o, u—aloud, and begin with a, and then hold your mouth and lips firmly in the same position, you will find that all the other vowels also come out as a. If, on the other hand, you begin with your mouth and lips in the rounded and somewhat thrust-out position necessary to say o, and try to repeat the rest of the vowels, you will find that you cannot say them at all, but only different forms of o. When you have convinced yourself of this, repeat the vowels loudly and clearly without stopping to think about the position of the mouth, and notice how your lips, the tip and base of your tongue, and your soft palate and throat all change their positions for each successive vowel.

If you will try to sing the scale, beginning with a comfortable note about the middle of your voice range, and letting your mouth take the shape for that note unconsciously, you will find that, as you sing up the scale, you change the shape of your mouth, lips, and tongue at every note, thrusting the lips and mouth further forward as if to whistle, narrowing the opening and closing up the back of your throat for the high notes.

On the other hand, as you sing down, you tend to open the mouth and lips more widely, to drop the bottom of your mouth—that is, the base of your tongue—toward your throat, and your chin down toward your chest. Again you will find, just as in the case of the different vowels, that you can sing any tone clearly and musically after putting the mouth in precisely the shape that best fits that tone; and learning how to do this is a most important part of vocal training.

What we call words are simply breath sounds and voice-box sounds chopped into convenient lengths by the movements of the tongue and lips and throat. So when we come to the question of clear and pleasant speaking, or, as we term it, articulation, the lips and tongue have almost everything to do with making the difference between a clear, musical, and refined enunciation, which is so easy to understand that it is a pleasure to listen to it, and a slurred, drawling, squeaky, nasal kind of speech, which is as hard to understand as it is unpleasant to listen to.

Few of us can ever hope to develop a really great singing voice; but anyone who will take the pains can acquire a clear, distinct, and pleasing speaking voice; and perhaps half of us can learn to sing fairly well. But to do this, we must first have good, healthy, well-developed lungs and elastic chest walls, which can come only from plenty of vigorous exercise in the open air, combined with good food and well-ventilated rooms. We must have a healthy stomach, which will not fill up with gas and keep our diaphragms from going down and enlarging our chests properly; we must have clear nasal passages, good teeth, well-shaped mouths and flexible lips, which we are willing to use vigorously in articulating, or cutting up our voice sounds; and we must have good hearing and a well-trained ear. In short, the best way to get a clear, strong, pleasant voice is to have a vigorous, well-grown, healthy body.

FOOTNOTES:

[32] A famous violin-maker who lived about 200 years ago in Cremona, Italy. Fifty thousand dollars has been asked for an unusually choice "Strad."



CHAPTER XXV

THE TEETH, THE IVORY KEEPERS OF THE GATE

Why the Teeth are Important. The teeth are a very important part of our body and deserve far more attention and better care than they usually get. They are the first and most active part of our digestive system, cutting up and grinding foods that the stomach would be unable to melt without their help. In all animals except those that have horns or fists, the teeth are their most important weapons of attack and defense. So important are they in all animals, including ourselves, and so closely do they fit their different methods of food-getting and of attack and defense, that when scientists wish to decide what class, or group, a particular animal belongs to, they look first and longest at its teeth.

The shape and position of the teeth literally make the lower half of the face and give it half its expression. A properly grown and developed set of teeth not only is necessary to health and comfort, but helps greatly to make the face and expression attractive or unattractive. Few faces with bright eyes, clear skin, and white, regular, well-kept teeth are unpleasing to look at. Beauty and health are closely related, and we ought to try to have both. In fact, nine times out of ten, what we call beauty is the outward and visible sign of inward health. The healthier you are, the handsomer you'll be.

It is particularly important to understand the natural growth and proper care of the teeth because there are few organs in the body for which we are able to do so much by direct personal attention. Our stomachs, our livers, and our kidneys, for instance, are entirely out of sight, and more or less out of reach; but our teeth are both easily got at and in full view; and, to a large degree, upon the care that we give them while they are young, will depend not only their regularity and whiteness, but also the length of their life and the vigor and comfort of our digestion all our lives.



The first thing to be remembered about the teeth is that, hard and shiny and different from almost everything else in the body as they look, they are simply a part of the skin lining the mouth, hardened and shaped for their special work of biting and chewing. Much of the care needed to prevent decay should be given, not to the teeth themselves directly, but to the gums and the mucous membrane of the whole mouth. The gums and the mouth literally grew the teeth in the first place; and when they become diseased, they secrete acids which slowly eat away the crowns and roots of the teeth. Their diseases come chiefly from irritation by decaying scraps of food, or from the blocking of the nose so that air is breathed in through the mouth, drying and cracking the soft mucous membrane. After the acids from the diseased gums have attacked the teeth, the poisons of the germs that breed in the warmth and moisture of the mouth cause the teeth to decay. Eight times out of ten, if you take care of the gums the teeth will take care of themselves.

Structure of the Teeth. The upper half of the tooth, which pushes through and stands up above the jaw and the gum, we call the crown; and this is the portion that is covered with enamel, or "living glass." The body of the tooth under the enamel is formed of a hard kind of bone called dentine. The lower half of the tooth, which still is buried in the jaw, we call the root. Wrenching the lower or root part of the tooth loose from its socket in the jaw is what hurts so when a tooth is pulled. The crown of the tooth is hollow, and this hollow is filled with a soft, sensitive pulp, in which we feel toothache. Tiny blood vessels and nerve-twigs run up from the jaw to supply this pulp through canals in the roots of the tooth.



Kinds of Teeth. If you look at your own teeth in a mirror, the first thing that strikes you is your broad, white, shiny front teeth, four above and four below, shaped like the blade of a rather blunt chisel. Their shape tells what they are used for. Like chisels, they cut, or bite, the food into appropriate sizes and lengths for chewing between the back teeth; and from this use they are called the incisors, or "cutters." From having been used for so many generations upon the kind of food we live on, they have grown broader than the canines, the teeth next to them, and almost as long.

The canines are of a cone-like shape, although it is a pretty blunt cone, or peg. Those in the upper jaw lie almost directly under the centre of each eye, and are called the "eye-teeth"; though their proper name, from the fact that they are the most prominent teeth in the dog, is the canine teeth. These are our oldest and least changed teeth; and as you might guess from their shape, like a heavy, blunt spear-head, were originally the fighting and tearing teeth, and still have the longest and heaviest roots of any teeth in our jaws. If you slip your finger up under your upper lip, you can feel the great ridge of this root, standing out from the surface of the gum.

Lastly, looking farther back into our mouths, we see behind our canines a long row of broad, flat-topped, square-looking teeth, which fill up the largest part of our jaws. Again their shape tells what they are used for. They are not sharp enough to cut with, or pointed enough to tear with, but are just suited for crushing and grinding into a pulp, between their broad, flat tops, any food that may be placed between them; and from this grinding they are called the molars, or "mill" teeth. If you will look closely at the back ones, you will see that each of them has four corners, or cusps, with a cross-shaped, sunken furrow in the centre, where they come together. After they have been used in grinding food for some years and rubbing against each other, these little corner projections become worn away, and their tops become almost flat. Those in the upper jaw have three roots, and those in the lower jaw have two, so that they are solidly anchored for their heavy, grinding work. The first two molars in each jaw, behind the canines, are smaller than the others and made up of only two pieces instead of four, and hence are called the bicuspids, or "two-cusped" teeth.

As we are what the scientists call an omnivorous, or "all-devouring," animal, able to eat and live upon practically every kind of food that any animal on earth can deal with,—animal and vegetable, soft and hard, wet and dry; fruits, nuts, crabs, roots, seaweeds, insects, anything that we can get our teeth into,—we have kept in working condition some of every kind of teeth possessed by any living animal; and the most important rule for keeping our teeth in health is to give all these kinds something to do.

Just as in other animals the teeth appear when needed, and grow into the shape required, so they grow in our own mouths when they are wanted, and of the size and shape required at the time. We are born without any teeth at all; and it is only when we begin to need a little solid food added to our milk diet,—when we are about seven months old,—that our first teeth appear; and these are incisors, first of all in the lower jaw. Then, at average intervals of about three months, the other incisors and the canines appear and, last of all, the molars, so that at about two years of age we have a complete set of twenty teeth. These are called the milk teeth.

Most animals (mammals) have formed the habit of growing two sets of teeth—a smaller, slighter set for use during the first few months or years of life, and a larger, heavier set to come in and take their place after the jaws have grown to somewhat more nearly their permanent size. In our mouths, at about seven years of age, a larger, heavier tooth pushes up behind the last milk tooth,—called the "seventh year molar,"—the milk teeth begin to loosen and fall out, and their places are taken by other new teeth budding up out of the jaw just as the first set did. These take a still longer time to grow, so that the last four of the full set of thirty-two do not come through the gums until somewhere between our eighteenth and twentieth years. These last four teeth, for the rather absurd reason that they do not appear until we are old enough to be wise, are known as the "wisdom teeth." Instead of being, as one might expect, the hardest and longest-lived of all our teeth, they are the smallest and worst built of our molars and among the first of our permanent teeth to break down and disappear. Not only so, but our jaws are so much shorter than they were in the days when man fought with his teeth and knew nothing about cooking and had no tools or utensils with which to grind and prepare his food, that there is scarcely room in them for these last teeth to come through. They often cause a great deal of pain in the process, and may even break through at the side of the jaw and cause abscesses and other troubles.



Care of the Teeth. The most important thing for the health of any organ in the body is to give it plenty of exercise, and this is especially true of our teeth. This exercise can be secured by thoroughly chewing, or masticating, all our food, of whatever sort, especially breads, biscuits, and cereals. Thorough chewing not only gives valuable exercise to the teeth, but, by grinding up these foods thoroughly, makes them easier for the stomach to digest; and, by mixing them well with the saliva, enables it to change the starch into sugar. Meats, fish, eggs, cheese, etc., do not need to be mixed with the saliva, nor to be ground so fine for easy digestion in the stomach, and hence do not require such thorough chewing, though it is better to make a rule of chewing all food well. We can exercise our teeth also by eating plenty of foods that require a good deal of chewing, especially the crusts of bread, and vegetables such as corn, celery, lettuce, nuts, parched grains, and popcorn.

It is most important to keep the nasal passages clear and free, and the teeth sound and regular by proper dental attention, so that the jaws will grow properly, and each tooth will strike squarely against its fellow in the opposite jaw, and both jaws fit snugly and closely to each other, making the bite firm and clean, and the grinding close and vigorous. If we are mouth-breathers, our jaws will grow out of shape, so that our teeth are crowded and irregular and do not meet each other properly in chewing. Pressure upon the roots of the teeth, from meeting their fellows of the opposite jaw in firm, vigorous mastication, is one of the most important means of keeping them sound and healthy. Whenever a tooth becomes idle and useless, from failing to meet its fellow tooth in the jaw above or below properly, or from having no fellow tooth to meet, it is very likely to begin to decay.

The next important thing in keeping the teeth healthy is to keep them thoroughly clean. The greatest enemies of our teeth are the acids that form in the scraps of food that are left between them after eating. Meats are not so dangerous in this regard as starches and sugars, because the fluids resulting from their decay are alkaline instead of acid; but it is best to keep the teeth clear of scraps of all kinds. This can best be done by the moderate and gentle use of a quill, or rolled wooden tooth-pick, followed by a thorough brushing after each meal with a rather stiff, firm brush. Then use floss-silk, or linen or rubber threads to "saw" out such pieces as have lodged between the teeth.

This brushing should be given, not merely to the teeth, but to the entire surface of the gums as well; for, as we have seen, it is the gums that make or spoil the health of the teeth, and they, like all other parts of the body, require plenty of exercise and pressure in order to keep them healthy. In the early days of man, when he had no knives and gnawed his meat directly off the bones, and when he cracked nuts and ground all his grain with his teeth, the gums got an abundance of pressure and friction and were kept firm and healthy and red; but now that we take out the bones of the meat and stew or hash it, have all our grain ground, and strip off all the husks of our vegetables and skins of our fruits, though we have made our food much more digestible, we have robbed our gums of a great deal of valuable friction and exercise. The most practical way to make up for this is by vigorous massage and scrubbing with a tooth-brush for five minutes at least three times a day. It will hurt and even make the gums bleed at first; but you will be surprised how quickly they will get used to it, so that it will become positively enjoyable.



It is good to use some cleansing alkaline powder upon the brush. The old-fashioned precipitated chalk, which makes the bulk of most tooth powders, is very good; but an equally good and much cheaper and simpler one is ordinary baking soda, or saleratus, though this will make the gums smart a little at first. Any powder that contains pumice-stone, cuttle-fish bone, charcoal, or gritty substances of any sort, as many unfortunately do, is injurious, because these scratch the enamel of the teeth and give the acids in the mouth a chink through which they may begin to attack the softer dentine underneath the "glaze" of enamel.

Antiseptic powders and washes, while widely advertised, are not of much practical value, except for temporary use when you have an abscess in your gums, or your teeth are in very bad condition. It is almost impossible to get them strong enough to have any real effect in checking putrefaction of the food or diseases of the gums, without making them too irritating or poisonous. If you keep the gums and teeth well brushed and healthy, you will need no antiseptics.

Not only should the teeth be kept thoroughly clean and sweet for their own sake, but also for the sake of the stomach and the health of the blood and the whole body. The mouth, being continually moist and warm and full of chinks and pockets, furnishes an ideal breeding ground for all kinds of germs; and the average, uncleansed human mouth will be found to contain regularly more than thirty different species of germs, each numbering its millions! Among them may sometimes be found the germs of serious diseases such as pneumonia, diphtheria, and blood-poisoning, just waiting, as it were, their opportunity to attack the body. In fact, a dirty, neglected mouth is one of the commonest causes of disease.



CHAPTER XXVI

INFECTIONS, AND HOW TO AVOID THEM

What Causes Disease. The commonest and most dangerous accident that is likely to happen to you is to catch some disease. Fortunately, however, this is an accident that is as preventable as it is common. Indeed, if everybody would help the Board of Health in its fight against the spread of the common "catchable" diseases, these diseases could soon be wiped out of existence. Every one of them is due to dirt of some sort; and absolute cleanness would do away with them altogether.

Diseases that are "catching," or will spread from one person to another, are called infections; and all of them, as might be supposed from their power of spreading, are due to tiny living particles, called germs—so tiny that they cannot be seen except under a powerful microscope. Nine-tenths of these disease germs are little plants of the same class as the moulds that grow upon cheese or stale bread, and are called bacteria, or bacilli. The different kinds of bacteria, or bacilli, are usually named after the diseases they produce, or else after the scientists who discovered them. For instance, the germ that causes typhoid fever is called the bacillus typhosus; that which causes tuberculosis is called the bacillus tuberculosis; while the germ of diphtheria known as the Klebs-Loeffler bacillus, after the two men who discovered it.

A few kinds of disease germs belong to the animal kingdom, though all germs are so tiny that you would have to have a very powerful microscope to tell the difference between the animal germs and the bacilli, or little plants. Most of these animal germs are called protozoa and cause diseases found in, or near, the tropics, like malaria and the terrible "sleeping sickness" of Africa. Smallpox, yellow fever, and hydrophobia—the disease that results from the bite of a mad dog—are also probably due to animal germs.

So far as prevention is concerned, however, it makes practically little difference whether infectious diseases are due to an animal or a vegetable germ, or to one bacillus or another. They all have two things in common: they can be spread only by the touch of an infected person, and "touch" includes breath,—indeed "by touch" is the meaning of both infectious and contagious; and they can all be prevented by the strictest cleanness, or killed by various poisons known as germicides ("germ-killers"), or disinfectants. Most of these germicides are, unfortunately, poisonous to us as well; for, as you will remember, our bodies are made up of masses of tiny animal cells, not unlike the animal germs. Most of the germicides, therefore, have to be used against germs while they are outside of our bodies.

Scripture says that "a man's foes shall be they of his own household," and this is true of disease germs. They grow and flourish—and, so far as history tells us, the diseases they cause seem to have started—only where people are crowded together in huts or houses, breathing one another's breaths and one another's perspiration, and drinking one another's waste substances in the well water. This fact has, however, its encouraging side; for, since this habit of crowding together, which we call civilization, or "citification," has caused and keeps causing these diseases, it can also cure them and prevent their spread if all the people will fight them in dead earnest. No amount of money, or of time, that a town or a county can spend in stamping out these infectious diseases would be wasted. Indeed, every penny of it would be a good investment; for, taken together, they cause at least half, and probably nearly two-thirds, of all deaths. Not only so, but most of the so-called chronic diseases of the heart, kidneys, lungs, bones, and brain are due to the after-effects of their toxins, or poisons.

How Disease Germs Grow and Spread. But perhaps you will ask, "If these bacteria and protozoa are so tiny that we have to use a microscope, and one of the most powerful made, in order even to see them, how is it that they can overrun our whole body and produce such dangerous fevers and so many deaths?" The answer is simply, "Because there are so many millions of them; and because they breed, or multiply, at such a tremendously rapid rate." When one of these little bacilli breeds, it doesn't take time to form buds and flowers and seeds, like other plants, or even the trouble to lay eggs like an insect or a bird, but simply stretches itself out a little longer, pinches itself in two, and makes of each half a new bacillus.

This is known as fission or "splitting," and is of interest because this is the way in which the little cells that make up our own bodies increase in number; as, for instance, when a muscle is growing and enlarging under exercise, or when more of the white blood cells are needed to fight some disease. Remember that we and the disease germs are both cells; and that, if they are numbered by millions, we are by billions; and that we are made up of far the older and the tougher cells of the two. Except in a few of the most virulent and deadly of fevers, like the famous "Black Death," or bubonic plague, and lock-jaw, or tetanus, ninety-five times out of a hundred when disease germs get into our bodies, it is our bodies that eat up the germs instead of the germs our bodies. Keep away from disease germs all that you reasonably and possibly can; but don't forget that the best protection against infectious diseases, in the long run, is a strong, vigorous, healthy body that can literally "eat them alive."

Grow that kind of body, keep it perfectly clean inside and out, and you have little need to fear fevers, or indeed any other kind of disease; for you will live until you are old enough to die—and then you'll want to, just as you want to go to sleep when you are tired. Remember that this fight against the fevers is a winning fight, this study of disease germs a cheering and encouraging one, because it will end in our conquering them, not merely nine times out of ten, but ninety-nine times out of a hundred.

We are not making this fight just to escape death; what we are fighting for is to live out a full, useful, and happy life. And we already have five chances to one of gaining this, and the chances are improving every year; for science has already raised the average length of life from barely twenty years to over forty. Broadly speaking, if you will keep away from every one whom you know to have an infectious disease; wash your hands always before you eat, or put anything into your mouth; keep your fingers, pencils, pennies, and pins out of your mouth,—where they don't belong; live and play in the open air as much as possible and keep your windows well open day and night, you will avoid nine-tenths of the risks from germs and the dangers that they bring in their wake.

Children's Diseases. We have already studied two of the greatest and most dangerous diseases, and the way to conquer them—tuberculosis, or consumption, in the chapter on the lungs; and typhoid fever, in the chapter on our drink. One of the next most important groups of "catching" diseases—important because, though very mild, they are so exceedingly common,—is that known as the "diseases of childhood," or "diseases of infancy" because they are most likely to occur in childhood. So common are they that you know their names almost as well as you know your own—measles, mumps, whooping cough, scarlet fever, and chicken-pox. Though they are in no way related to one another, so far as we know (indeed, the precise germs that cause two of them—measles and scarlet fever—have not yet positively been determined), yet they can be practically taken together, because they are all spread in much the same way, they all begin with much the same sort of sneezing and inflammation of the nose and throat, they can all be prevented by the same means, and, if properly taken care of, they result in complete recovery ninety-five times out of a hundred.



Any child who has sneezing, running at the nose or eyes, sore throat, or cough, especially with headache or backache, a flushed face and feverishness, ought to be kept at home from school and placed in a well-ventilated, well-lighted room by himself for a day or two, until it can be seen whether he has one of these children's diseases, or only a common cold. If it turns out to be measles, scarlet fever, or whooping cough, he should then be kept entirely away from other children in a separate room, or, where that is impossible, in a special hospital or ward for the purpose; he should be kept in bed and given such remedies as the doctor may advise. Then no one else will catch the disease from him; and within from two to five weeks, he will be well again. The most important thing is not to let him get up and begin to run about, or expose himself, too soon; five times as many deaths are caused by taking cold, or becoming over-tired, or by injudicious eating, during recovery after measles, scarlet fever, and whooping cough, as by the disease itself. This one caution will serve two purposes; for, as a sick child's breath, and the scales from his skin, and what he coughs out from his mouth and nose are full of germs, and will give the disease to other children from two to four weeks after the fever has left him, he ought to be kept by himself—"in quarantine," as we say—for this length of time, which is just about the period needed to protect him from the dangers of relapse or taking cold. Boards of Health fix this period of quarantine by law and put a colored placard on the house to warn others of the danger of infection.



Colds and Sore Throats. A milder and even more common kind of infection is that known as common colds. These, as shown by their name, were once supposed to be due to exposure to cold air, or drafts, or to becoming wet or chilled. But, while a few of them are so caused, at least eight, and probably nine, out of ten are due to germs caught from somebody else. They are never caught in the open air and very seldom in cold, pure fresh air of any sort, but almost always in the hot, foul, stuffy, twice-breathed air of bedrooms, schoolrooms, churches, theatres, halls, sleeping cars, etc. The colds, for instance, that you catch when traveling, are usually due not to drafts or damp sheets, but to the crop of cold germs left behind by the last victim.

You have probably known of colds that have run through a family or a school or a shop. It is well worth trying to keep away from the infection of colds, because not only is their coughing and sore throat and hoarseness and running at the nose very disagreeable and uncomfortable, but they may cause almost as many different kinds of serious troubles in heart, kidneys, and nervous system as any of the other infections. In fact, they probably cause more than any other, because they are at least ten times as common and frequent. For instance, many cases of rheumatism, or rheumatic fever, come after attacks in the nose and throat, which cannot be distinguished from a common cold or ordinary tonsilitis. Indeed, it is more than probable that one of the ten or a dozen different germs that may get into your nose or throat and give you a cold, is the germ that causes rheumatism. At all events, it would be fairly safe to say, "No colds, no rheumatism."

Whenever you have a cold, keep away from everybody that you possibly can and stay at home from school or business for a day or two. You will do no good to yourself or others, working in that condition; and you may infect a dozen others. If you find anyone in your class or room or shop, sneezing or coughing or running at the nose, report him to your teacher or foreman; and if he won't send him home, keep away from him as much as possible.

Diphtheria. Another common and serious disease, until quite recently very fatal, is diphtheria. This is caused by getting into your mouth or nose the germs from another case of the disease. This disease also is most likely to occur in childhood, though it may attack a person of any age, and is always serious. It may be prevented from spreading by keeping children who have it shut up in rooms, or wards, by themselves and keeping all other children away from them, or from their nurses or those who have anything to do with them. Up to about thirty years ago, it was one of the deadliest and most terrible diseases that we had anything to do with. We knew absolutely nothing that would cure it, or even check its course; and nearly half of the children attacked by it died.

About that time, however, two scientists, Klebs and Loeffler, discovered that, by taking some of the membrane, or tough growth that forms in the throat in this disease, and by rubbing it over a plate of gelatin jelly, they could grow on that gelatin a particular kind of germ. This germ, or bacillus, they then put into the throats of guinea pigs, and found that it would give them diphtheria.

This is the way disease germs are discovered, or, as we say, identified; but of course this did not give at once any remedy for the disease. Scientists soon found, however, that, if a very small number of these bacilli were put into a guinea pig's throat, it would have diphtheria, but in a very mild form. If, when it had recovered, it was again infected, it would stand a much larger dose of the bacilli without harm. This made them suspect that some substance had been formed in the guinea-pig's blood that killed the bacillus or worked against its toxin, or poison; and soon, to their delight, they succeeded in finding this substance, which they called antitoxin (meaning "against poison"). Then came the idea that if they could only get enough of this antitoxin, and inject it into the blood of a child who had diphtheria, it might cure the disease. A guinea pig is such a tiny animal that the amount of antitoxin which it could form would be far too small to cure a man, or even a child. So larger animals were taken; and it was finally found that the largest and strongest of our domestic animals, the horse, would, if the diphtheria germs were injected into its blood, make such large amounts of antitoxin that merely by drawing a quart or two of the blood—and closing up the vein again—enough antitoxin could be got to cure fifty or a hundred children of diphtheria. This treatment has not the slightest harmful effect upon the horse. The pain of injecting is only like sticking a pin through the skin, while the pain of bleeding is no greater than cutting your finger. There are now at our great manufacturing laboratories whole stables full of horses, for the production of this wonderful remedy.



With this remedy, our entire feeling toward diphtheria is changed. Instead of dreading it above all things, we know now, from hundreds of thousands of cures, that, if a case is seen on the first day of the disease, and this antitoxin injected with a hypodermic needle, it is almost certain that the patient will recover; not more than two or three cases out of a hundred will fail. If the case is seen and treated on the second day, all but four or five out of a hundred will recover; and if on the third day, all but ten. In fact, the average death rate of diphtheria has been cut down now from forty-five per cent to about six per cent.

We now have antitoxins, or vaccines, for blood-poisoning; for typhoid fever; for one of the forms of rheumatism; for boils; for the terrible cerebro-spinal meningitis, or "spotted fever"; and for tetanus, or lock-jaw. And every year there are one or two other diseases added to the list of those that have been conquered in this way.

None of these vaccines is so powerful, or so certain in its effects, as the diphtheria antitoxin. But they are very helpful already; and some of them, particularly the typhoid vaccine, are of great value in preventing the attack of the disease, as small doses of it given to persons who have been exposed to the infection, or are obliged to drink infected water, as in traveling or in war, very greatly lessen their chances of catching the disease.

Vaccination, the Great Cure for Smallpox. Another valuable means of preventing disease by means of its germs is by putting very small doses of the germs into a patient's body, so that they will give him a very mild attack of the disease, and cause the production in his blood of such large amounts of antitoxin that he will no longer be liable to an attack of the violent, or dangerous, form of the disease. Vaccines, for this purpose, usually consist either of a very small number of the disease germs, or of a group of them, which have been made to grow upon a very poor soil or have been chilled or heated so as to destroy their vitality or kill them outright. When these dead, or half-dead, bacilli are injected into the system, they stir up the body to produce promptly large amounts of its antitoxin. In some cases the reaction is so prompt and so vigorous that the antitoxin is produced almost without any discomfort, or disturbance, and the patient scarcely knows anything about it. In others there will be a slight degree of feverishness, with perhaps a little headache, and a few days, or hours, of discomfort. When this has passed, then the individual is protected against that disease for a period varying from a few months to as long as seven or eight years, or even for life.

The best-known and oldest illustration of the use of these vaccines is that of smallpox. A little more than a hundred years ago, an English country doctor by the name of Jenner discovered that the cows in his district suffered from a disease accompanied by irritation upon their skins and udders, which was known as "cowpox." The dairymaids who milked these cows caught this disease, which was exceedingly mild and was all over within four or five days; but after that the maids would not take smallpox, or, as we say, were immune against it. Smallpox at that time was as common as measles is now. Nearly one-fourth of the whole population of Europe was pock-marked, and over half the inmates in the blind asylums had been made blind by smallpox. So common was it that it was quite customary to take the infectious matter from the pocks upon the skin of a mild case and inoculate children with it, so as to give them the disease in mild form and thus protect them against a severe, or fatal, attack; just as in country districts, a few years ago, some parents would expose their children to measles when it happened to be a mild form, so as to "have it over with."

It occurred to Dr. Jenner that if this inoculation with cowpox would protect these milkmaids, it would be an infinitely safer thing to use to protect children than even the mildest known form of inoculation. So he tried it upon two or three of his child patients, after explaining the situation to their parents, and was perfectly delighted when, a few months afterward, these children happened to be exposed to a severe case of smallpox and entirely escaped catching the disease. This was the beginning of what we now call vaccination.

The germ of cowpox, which is believed to be either the cow or horse variety of human smallpox, is cultivated upon healthy calves. The matter formed upon their skin is collected with the greatest care; and this is rubbed, or scraped, into the arm of the child. It is a perfectly safe and harmless cure; and although it has been done millions of times, never has there been more than one death from it in 10,000 cases. In a little over a hundred years it has reduced smallpox from the commonest and most fatal of all diseases to one of the rarest. But in every country in the world into which vaccination has not been introduced, smallpox rages as commonly and as fatally as ever. For instance, between 1893 and 1898 in Russia, where a large share of the people are unvaccinated, 275,000 deaths occurred from smallpox; in Spain, where the same condition exists, 24,000. In Germany, on the other hand, where vaccination is practically universal, there were in the same period only 287 deaths—1/1000 as many as in Russia; and in England, only a slightly greater number.

Another illustration, which comes closer home, is that of the Philippine Islands. Before they were annexed by the United States, vaccination was rare, and thousands of deaths from smallpox occurred every year. In 1897, after the people had been thoroughly vaccinated, there was not a single death from this cause in the whole of the Islands.



This discovery of Jenner's was most fortunate; for vaccination remains until this day absolutely the only remedy of any value whatever that we possess against smallpox.

Quarantine, inoculation, improvement of living and sanitary conditions, the use of drugs and medicines of all sorts other than vaccination, have no effect whatever upon either the spread or the fatality of the disease. The author, when State Health Officer of Oregon, saw the disease break out in a highly-civilized, well-fed, well-housed community, and kill eleven out of thirty-three people attacked, just as it would have done in the "Dark Ages." Not one of the cases that died had been vaccinated; and, with but one exception (and in this the proof of vaccination was imperfect), every vaccinated case recovered. Vaccination will usually protect for from five to ten years; then it is advisable to be re-vaccinated, and in six to eight years more, another vaccination should be attempted. This third vaccination will usually not "take," for the reason that two successful vaccinations will usually protect for life.

Unexpected as it may seem, vaccination is not only a preventive of smallpox, but a cure for it. The reason being that vaccinia, the disease resulting from successful vaccination, being far milder than smallpox, runs its course more quickly,—taking only two days to develop,—while smallpox requires anywhere from seven to twenty days to develop after the patient has been infected, or exposed. So, if anyone who has been exposed to smallpox is vaccinated any time within a week after exposure, the vaccine will take hold first, and the patient will have either simple vaccinia, with its trifling headache and fever, or else a very mild form of smallpox.

Some persons object to having children deliberately infected with even the mildest sort of disease; but this is infinitely better than to allow, as was the case before vaccination, from one-fourth to one-fifth of them to be killed, twenty-five per cent of them to be pock-marked, and ten per cent of them to be blinded by this terrible disease. So far as any after-effects of vaccination are concerned, careful investigation of hundreds of thousands of cases has clearly shown that it is not so dangerous as a common cold in the head.

Infantile Paralysis. Another disease that has been unpleasantly famous of late is also caused and spread by a germ. This is a form of laming or crippling of certain muscles in childhood known as infantile paralysis. It is not a common disease, though during the last two years there has been an epidemic of it in the United States, especially in New York and Massachusetts. The only things of importance for you to know about it are that it begins, like the other infections, with headache, fever, and usually with "snuffles" or slight sore throat, or an attack of indigestion; and that its germ is probably spread by being sneezed or coughed into the air from the noses and throats of the children who have it, and breathed in by well children. The best known preventive of serious results from this disease is the same as in the rest of infectious diseases, namely, rest in bed, away from all other children, which at the same time stops the spread of it. It furnishes one more reason why all children having the "snuffles" and sore throat with fever and headache should be kept away from school and promptly put to bed and kept there until they are better.

The reason why the disease produces paralysis is that its germs specially attack the spinal cord, so as to destroy the roots of the nerves going to the muscles. Unless the harm done to the spinal cord is very severe, other muscles of the arm or the leg can very often be trained to take the place and to do the work of the paralyzed muscles, so that while the limb will not be so strong as before, it will still be quite useful.

Malaria. Practically the only disease due to animal germs, which is sufficiently common in temperate or even subtropical regions to be of interest to us, is malaria, better known perhaps as ague, or "chills-and-fever." This disease has always been associated with swamps and damp marshy places and the fogs and mists that rise from them; indeed its name, mal-aria, is simply the Italian words for "bad air." It is commonest in country districts as compared with towns, in the South as compared with the North, and on the frontier, and usually almost disappears when all the ponds and swamps in a district are drained and turned into cultivated land or meadows.

About four hundred years ago, the Spanish conquerors of America were fortunate enough to discover that the natives of Peru had a bitter, reddish bark, which, when powdered or made into a strong tea, would cure ague. This, known first as "Peruvian bark," was introduced into Europe by the intelligent and far-sighted Spanish Countess of Chincon; and, as she richly deserved, her name became attached to it—first softened to "cinchona" and later hardened to the now famous "quinine." But for this drug, the settlement of much of America would have been impossible. The climate of the whole of the Mississippi Valley and of the South would have been fatal to white men without its aid.



But although we knew that we could both break up and prevent malaria by doses of quinine large enough to make the head ring, we knew nothing about the cause—save that it was always associated with swamps and marshy places—until about forty years ago a French army surgeon, Laveran, discovered in the red corpuscles of the blood of malaria patients, a little animal germ, which has since borne his name. This, being an animal germ, naturally would not grow or live like a plant-germ and must have been carried into the human body by the bite of some other animal. The only animals that bite us often enough to transmit such a disease are insects of different sorts; and, as biting insects are commonly found flying around swamps, suspicion very quickly settled upon the mosquito.



By a brilliant series of investigations by French, Italian, English, and American scientists, the malaria germ was discovered in the body of the mosquito, and was transmitted by its bite to birds and animals. Then a score or more of eager students and doctors in different parts of the world offered themselves for experiment—allowed themselves to be bitten by infected mosquitoes, and within ten days developed malaria. At first sight, this discovery was not very encouraging; for to exterminate mosquitoes appeared to be as hopeful a task as to sweep back the Atlantic tides with a broom. But luckily it was soon found that the common piping, or singing, mosquito (called from his voice Culex pipiens) could not carry the disease, but only one rather rare kind of mosquito (the Anopheles), which is found only one-fiftieth as commonly as the ordinary mosquito. It was further found that these malaria-bearing mosquitoes could breed only in small puddles, or pools, that were either permanent or present six months out of the year, and that did not communicate with, or drain into, any stream through which fish could enter them. Fish are a deadly enemy of the mosquito and devour him in the stage between the egg and the growth of his wings, when he lives in water as a little whitish worm, such as you may have seen wriggling in a rain-barrel.



It was found that by hunting out a dozen or twenty little pools of this sort in the neighborhood of a town full of malaria, and filling them up, or draining them, or pouring kerosene over the surface of the water, the spread of the malaria in the town could be stopped and wiped out absolutely. This has been accomplished even in such frightfully malarial districts as the Panama Canal Zone, and the west coast of Africa, whose famous "jungle fever" has prevented white men from getting a foothold upon it for fifteen hundred years. Since the young mosquitoes, in the form of wrigglers, or larvae, cannot grow except in still water, draining the pools kills them; and, as they must come to the surface of the water to breathe, pouring crude petroleum over the water—the oil floating on the surface and making a film—chokes them.

The common garden mosquito, while not dangerous, is decidedly a nuisance and can be exterminated in the same way—by draining the swamps and pools, or by flooding them with crude petroleum,—or by draining swamps or pools into fresh-water ponds and then putting minnows or other fish into these ponds. There is no reason why any community calling itself civilized should submit to be tormented by mosquitoes if it will spend the few hundred, or the thousand, dollars necessary to wipe them out. It is prophesied that the use of quinine will soon become as rare as it is now common, because malaria will be wiped out by the prevention of the mosquito.

Disinfectants. So far we have been considering how to attack the germs after they have got into our bodies, or to prevent them from spreading from one patient to another; but there is still another way in which they may be attacked, and that is by killing, or poisoning them, outside the body. This process is generally known as disinfection, and is carried out either by baking, boiling, or steaming, or by the use of strongly poisonous fluids or gases, known as disinfectants.

While fortunately none of these disease germs can breed, or reproduce their kind, outside the human body, and while comparatively few of them live very long outside the human body, they may, if mixed with food or caught upon clothing, hangings, walls, or floors, remain in a sort of torpid, but still infectious, condition for weeks or even months. Consequently, it has become the custom to take all the bedding, clothing, carpets, curtains, etc., that have touched a patient suffering from a contagious disease, or have been in the room with him, and also any books that he may have handled, any pens or pencils that he may have used, and either destroy them, or bake, boil, or fumigate them with some strong germicidal, or disinfectant, vapor.



This is usually done by closing up tightly the sick-room, putting into it all clothing, bedding, pictures, books, hangings, and other articles used during the illness (except wash-goods, which, of course, can be sterilized by thorough boiling; and dishes and table utensils, which also can be scalded and boiled); draping the carpet over chairs so as to expose it on all sides, opening closets and drawers, and then filling the room full of some strong germ-destroying fumes.

One of the best disinfectants, and the one now most commonly used by boards of health for this purpose, is formaldehyde—a pungent, irritating gas, which is an exceedingly powerful germ-destroyer. This, for convenience in handling is usually dissolved, or forced into water, which takes up about half its bulk; and the solution is then known as formalin.

When formalin is poured into an open dish, it rapidly evaporates, or gives up its gas; and, if it be gently heated, this will be thrown off in such quantities as to completely fill the room and penetrate every crevice of it, and every fold of the clothing or hangings. One pound, or pint, of formalin will furnish vapor enough to disinfect a room eight feet square and eight feet high, so the amount for a given room can thus be calculated. The formalin vapor will attack germs much more vigorously and certainly if it be mixed with water vapor, or steam; so it is usually best either to boil a large kettle of water in the room for half an hour or more, so as to fill the air with steam, before putting in the formalin, or to use a combination evaporator with a lamp underneath it, which will give off both formalin and steam. This, if lighted and placed on a dish in the centre of a wash-tub or a large dishpan, with two or three inches of water in the bottom of it, can be put into the room and left burning until it goes out of its own accord.

Another very good method is to take a pan, or basin, with the required amount of formalin (not more than an inch or two inches deep) in the bottom of it, get everything ready with doors and windows fastened tight and strips of paper pasted across the cracks, pour quickly over the formalin some permanganate of potash (about a quarter of a pound to each pound of formalin), and then bolt for the door as quickly as possible to avoid suffocation. The resulting boiling up, or effervescence, will throw off quantities of formaldehyde gas so quickly as to drive it into every cranny and completely through clothing, bedding, etc. The room should be left closed up tightly for from twelve to thirty-six hours, when it can be opened—only be careful how you go into it, first sniffing two or three times to be sure that all the gas has leaked out, or holding your breath till you can get the windows open; and in a few hours the room will be ready for use again.

Another older and much less expensive disinfectant for this purpose is common sulphur. From one to three pounds of this, according to the size of the room, is burned by a specially prepared lamp in a pan placed in the centre of a dishpan of water, and the vapor thus made is a very powerful disinfectant. This, however, is a very poisonous and suffocating gas (as you will remember if you have ever strangled on the fumes of an old-fashioned sulphur match) and, compared with formalin, is nearly five times as poisonous to human beings, or animals, and not half so much so to the germs. Where formalin cannot be secured, sulphur is very effective; but its only merit compared with formalin is that it is cheaper, and more destructive to animal parasites and vermin such as bugs, cockroaches, mice, rats, etc., when these happen to be present. Formalin has the additional advantage of not tarnishing metal surfaces, as sulphur does.

It is a good thing for every household and every schoolroom to have a bottle of formalin on hand, so that you may sniff the vapor of it into your nostrils and throat if you think you have been exposed to a cold, or other infectious disease, or make a solution with which to wash your hands, handkerchiefs, pencils, etc., after touching any dirt likely to contain infection. Half a teaspoonful in a bowl of water is enough for this. A saucerful of it placed in an air-tight box, or cabinet, will make a disinfecting chamber in which pencils, books, etc., can be placed over night; and a teaspoonful of it in a quart of water will make an actively germ-destroying solution, which can be used to soak clothing, clean out bedroom utensils, or pour down sinks, toilets, or drains. It is a good thing also to pour a few teaspoonfuls occasionally on the floor of the closets in which your shoes, trousers, dresses, and other outdoor clothing are kept, as these are quite likely to be contaminated by germs from the dust and dirt of the streets.

Formalin is one of the best and safest general disinfectants to use. Its advantages are, that it is nearly ten times as powerful a germicide as carbolic acid, or even corrosive sublimate, so that it may be used in a solution so weak as to be practically non-poisonous to human beings. It is so violently irritating to lips, tongue, and nostrils as to make it almost impossible for even a child to swallow it, while the amount that would be absorbed if taken into the mouth and spit out again would be practically harmless, so far as danger to life is concerned, though it would blister the lips and tongue.

Bacteria, our Best Friends. While, naturally, the bacteria that do us harm by producing disease are the ones that have attracted our keenest attention and that we talk about most, it must never be forgotten that they form only a very, very small part of the total number of bacteria, or germs. These tiny little germs swarm everywhere; and the mere fact that we find bacteria in any place, or in any substance, is no proof whatever that we are in danger of catching some disease there.

All our farm and garden soil, for instance, is full of bacteria that not only are harmless, but give that soil all its richness, or fertility. If you were to take a shovelful of rich garden earth and bake it in an oven, so as to destroy absolutely all bacteria in it, you would have spoiled it so that seeds would scarcely grow in it, and it would not produce a good crop of anything. These little bacteria, sometimes called the soil-bacteria, or bacteria of decay, swarm in all kinds of dead vegetable and animal matter, such as leaves, roots, fruits, bodies of animals, fishes, and insects, and cause them to decay or break down and melt away. In doing this they produce waste substances, particularly those that contain ammonia, or nitrates, or some other form of nitrogen, which are necessary for the growth of plants or crops.

This is why soil can be made richer by scattering over it and plowing into it manure, waste from slaughter houses, or any other kind of decaying animal or vegetable matter. This is promptly attacked by the bacteria of the soil and turned into these easily soluble plant foods. The roots of the plants grown in the soil could no more take this food directly from dead leaves or manure than you could live on sawdust or cocoanut matting.

So, if it were not for these bacteria, or lower plants, there could be no higher, or green, plants. As animals live either upon these green plants, such as grass and grains, or upon the flesh of other animals that live upon plants, we can see that without the bacteria there would be no animal life, not even man. No bacteria, no higher life. It would be safe to say that, out of every million bacteria in existence, at least 999,999 are not only not harmful but helpful to us.

One large group of bacteria produces the well-known souring of milk; and while this in itself is not especially desirable, yet the milk is still wholesome and practically harmless, and its sourness prevents the growth of a large number of other bacteria whose growth would quickly make it dangerous and poisonous. Many races living in hot countries deliberately sour all the milk directly after milking, by putting sour milk into it, because, when soured, it will keep fairly wholesome for several days, while if not soured it would entirely spoil and become unusable within twenty-four hours.

Another group of bacteria, which float about in the air almost everywhere, are the yeasts, which we harness to our use for the very wholesome and healthful process of bread-making. Millions upon millions of bacteria of different sorts live and grow naturally in our stomachs and intestines; and while they are probably of no special advantage to us, yet at the same time the majority of them are practically, within reasonable limits—not to exceed a few billions or so—harmless.

Insect Pests. One kind of "dirt" that should be avoided with special care is insects of all sorts. No one needs to be told to try to keep a house, or a room, clear of fleas, bed-bugs, or lice; indeed to have these creatures about is considered a mortal disgrace. Not only is their bite very unpleasant, but they may convey a variety of diseases, including plague and blood poisonings of various sorts. But there is another insect pest far commoner and far more dangerous than either fleas or bed-bugs, whose presence we should feel equally ashamed of; and that is the common house fly. This filthy little insect breeds in, and feeds upon, filth, manure, garbage, and dirt of all sorts, and then comes and crawls over our food, falls into our milk, wipes his feet on our sugar and cake, crawls over the baby's face, and makes a general nuisance of himself. Take almost any fly that you can catch, let him crawl over a culture plate of gelatin, put that gelatin away in a warm place, and you will find a perfect flower-garden of germs growing up all over it, following the pattern made by the tracks of his dirty feet. In this garden will be found not "silver bells and cockle shells and pretty maids all in a row," but a choice mixture of typhoid bacilli, pus germs, the germs of putrefaction, tubercle bacilli, and the little seeds which, if planted in our own bodies, would blossom as pneumonia or diphtheria.



The fly is an unmitigated nuisance and should be wiped out. No half-way measures should be considered. Fortunately, this is perfectly possible; for his presence is our own fault and nothing else, as he can lay his eggs and hatch only in piles of dirt and filth found about our own houses, barns, and outbuildings. He is not a wild insect but a domestic one and is practically never found more than a few hundred yards away from some house or barnyard. His favorite place for breeding is in piles of stable manure, especially horse manure; but neglected garbage cans, refuse heaps, piles of dirt and sweepings, decaying matter of all sorts, which are allowed to remain for more than ten days or two weeks at a time, will give him the breeding grounds that he needs.



It takes him about two weeks to hatch and get away from these breeding places; so that if everything of this sort is cleaned up carefully once a week, or if, where manure heaps and garbage dumps have to remain for longer periods, they are sprinkled with arsenic, kerosene, corrosive sublimate, chloride of lime, or carbolic acid, he will perish and disappear as surely as grass will if you wash away the soil in which it grows. The presence of a fly means a dirty house or a dirty yard somewhere, and to discover a fly in your house should be considered a disgrace. Until people are aroused to the need of such cleanliness as will make flies disappear entirely, in most places it will be necessary, as warm weather approaches, to screen all doors and windows, and particularly all boxes, pantries, or refrigerators in which food is kept. If you cannot afford screens, use fly paper. These are all, however, only half-way measures and will give only partial relief. The best prevention of flies is absolute cleanliness. No dirt, no flies.

Dust, a Source of Danger. Dust is an easily recognized form of dirt. It is dangerous in itself and nearly always contains germs of one sort or another mixed in with it. Shops and factories whose processes make much dust are usually very unhealthy for the workers, who are likely to show a high death-rate from consumption.

Dust should be fought and avoided in every possible way. City streets should have good modern pavements,—preferably asphalt or some crude petroleum, or sawmill-waste, "crust," or coating,—which will not make any dust, and which can be washed down every night with a hose. In smaller towns where there is no pavement, dust may be prevented by regular sprinklings during the summer, preferably with some form of crude oil. Two or three full sprinklings of this will keep down the dust for the greater part of the summer.

If these measures are properly carried out, they will prevent most of the dust that accumulates in houses, as nearly all of this blows in through the windows or is carried in on shoes or skirts. When this has once floated in and settled down upon the walls, furniture, or carpets, be very careful how you disturb it; for, as long as it lies there, it will do you no harm, however untidy it may look. The broom and the feather duster and the dry cloth do almost as much harm as they do good; for while they may remove two-thirds of the dust from a room, they drive the other third right into your nose and throat, where the germs it contains can do the most possible harm. Dusting should always be done with a damp cloth; sweeping, with a damp cloth tied over a broom; and, wherever possible, a carpet sweeper, or, better still, a vacuum cleaner, should be used instead of a broom.

Carpets, window curtains, and any hangings that catch dust should be abolished—rugs that can be rolled up and taken out of doors to be shaken and beaten should be used instead; and too many pieces of bric-a-brac and ornaments should be avoided. All surfaces of walls, ceilings, and floors should be made as smooth and hard and free from angles, ledges, and projecting lines as possible. The colds usually caught by members of the family during "spring cleaning" are usually due to the swarms of germs stirred up from their peaceful resting places. Let those sleeping germs lie, until you can devise some means of removing them without brushing, or whisking, them straight into your nostrils.



CHAPTER XXVII

ACCIDENTS AND EMERGENCIES

Ordinarily, Accidents are not Serious. Accidents will happen—even in the best regulated families! While taking all reasonable care to avoid them, it is not best to worry too anxiously about the possibility of accidents; for a nervous, fearful state of mind is almost as likely to give rise to them as is a reckless and indifferent one. Fortunately, most accidents, especially with growing boys and girls, are comparatively trifling in their results, and to a considerable extent must simply be reckoned as part of the price that has to be paid for experience, self-control, and skill. To have keen senses, vigorous and elastic muscles, and a clear head, is better protection against accidents than too much caution; it is also the best kind of insurance that can be taken out against their proving serious. The real problem is not so much to avoid accidents as to be ready to meet them promptly, skillfully, and with good judgment when they occur, as they inevitably will. As the old masters of swordsmanship used to teach, "Attack is the best defense."

Luckily, healthy children are as quick as a cat and as tough as sole-leather—if they weren't, the race would have been wiped out centuries ago. Children in their play, on errands, going to and from school, and in excursions through the woods and the fields, run, of course, a great many risks. But in spite of all these dangers, the number of children killed, or even seriously injured, in these "natural" accidents, is not half of one per cent of those who die from disease or bad air or poor food or overwork.

Another cheering thing about accidents is that ninety-nine out of every hundred of them are not serious; and if you are only wise enough to know what to do—and still more what not to do—in taking care of them, you can recover from them safely and quickly. The bodies of healthy children have an astonishing power of repairing themselves. Their bones are not so brittle as those of "grown-ups"; and even when one of them is broken, if properly splinted and dressed, it will heal up in a little more than half the time required by the adult. And wounds and scratches and bruises, if kept perfectly clean, will heal very rapidly.

Probably the commonest of all accidents are cuts and scratches. So common is it for us to "bark" our knuckles, or our shins, or scratch ourselves on nails and splinters and drive pins into ourselves, or let our pocket knives slip and cut our fingers, that, if the human skin had not the most wonderful power of repairing itself,—not merely closing up the cut or the scratch, but making the place "as good as new,"—we should be seamed and lined all over our hands, arms, faces, and limbs like a city map, or scarred and pitted like a tattooed man, before we were fifteen years old. But of course, as you know, the vast majority of cuts and scratches and tears heal perfectly. They hurt when they happen; and they burn, or smart, for a few hours, or hurt, if bumped, for a few days afterward; but they heal soon and are forgotten.

On the other hand, some cuts and scratches will fester and throb and turn to "matter" (pus) and even give you fever and headache and blood poisoning. What makes the difference? It is never the size, or depth, of the scratch or cut itself, but simply the dirt that gets into it afterward. If a cut, or scratch, no matter how deep or ragged, be made with a clean knife-blade or sliver and kept clean afterward, it will never "matter" (suppurate) or cause blood poisoning. So if you know how to keep dirt out of cuts and scratches, you know how to prevent ninety-nine per cent of all the dangers and damage that may come from this sort of accident.

Not more than one cut or scratch in a thousand is deep enough to go down to an artery, so as to cause dangerous bleeding, or to injure an important nerve trunk. So, though no one would by any means advise you to be reckless about getting cut and scratched, yet it is better and safer to run some risk of cuts and scratches in healthy play when young, and learn how to keep them clean, than to grow up pale and flabby-muscled and cowardly.

How to Prevent Infection in Wounds. It is not just dirt that is dangerous,—although dirt of any sort is a bad thing to get into wounds and should be kept out in every possible way,—but dirt that contains those little vegetable bacteria that we call germs. The dirt most likely to contain these germs—called pus germs, because they cause pus, or "matter" in a wound—is dirt containing decaying animal or vegetable substances (particularly horse manure, which may contain the tetanus, or lock-jaw germ) and the discharges from wounds, or anything that has come near decayed meat or unhealthy gums or noses or teeth. This is why a cut or scratch made by a knife that has been used for cutting meat, or by a dirty finger-nail, or by the claw of a cat, or by the tooth of a rat, is often likely to fester and "run." Animals like rats and dogs and cats often feed upon badly decayed meat; and hence their teeth, or claws, are quite likely to be smeared with the germs that cause decay, and these will make trouble if they get into a wound.

Fortunately, the care of a cut or scratch is very simple and practically the same in all cases. Just make the wound thoroughly clean and keep it so until it is healed. For a slight clean cut or scratch, a good cleanser is pure water. Hold the hand or foot under the faucet or pump, and let the cool water wash it out thoroughly. If you are sure that the thing you cut it with was clean, let the blood dry on the cut and form a scab over it. If the wound is large, or there is any danger of the water of the well, or tap, having sewage in it (see chapter IX), it is better to boil the water before using it. Unless the blood is spurting in jerks from a cut artery, or bleeding very freely indeed, it is better to let the wound bleed, as this helps to wash out any dirt or germs that have got into it. When the bleeding has stopped, do not put on sticking plaster, because this keeps out the air and keeps in the sweat of the skin surrounding the wound, which is not healthful for the wound, and may also contain some weak pus germs.

If the wound is small, the old-fashioned clean white rag that has been boiled and washed is as good as anything that can be used for a dressing. Tear off a narrow strip from one to two inches wide and as many feet long, according to the position of the wound, roll it round the finger or limb three or four times, and then take a turn round the wrist or nearest joint, to keep the bandage from slipping off. If the wound be likely to keep on oozing blood, put on first a thickness of surgeon's cotton, or prepared cotton-batting, an ounce of which can be purchased for ten cents at any drugstore. This is an excellent dressing, because it not only sucks up, or absorbs any oozing from the wound, but is a perfect filter-protection against germs of all sorts from the outside. Ninety-nine simple wounds out of a hundred dressed in this way will heal promptly and safely without danger of pus, or "matter."

If the wound happens to have been made with a knife or tool that you are not absolutely sure was perfectly clean, or if the wound gets manure or road-dirt or other filth rubbed into it, then it is best to go at once to a doctor and let him give it a thorough antiseptic dressing, which consists of cleaning it out thoroughly with strong remedies, called antiseptics,—which kill the germs, but do not injure living tissues,—and then putting on a germ-proof dressing as before. This is one of the "stitches in time" which will save not only nine, but ninety-nine.

If you have a wound with dirt in it, and cannot reach a doctor, one of the best and safest antiseptics to use is peroxide of hydrogen. This is non-poisonous, and can be poured right into the wound. It will smart and foam, but will clean out and kill most of the germs that are there. Another safe antiseptic is pure alcohol. It is a good thing to have a bottle of one of these in the medicine-closet, or in your "war-bag" when camping out. A package of surgeon's cotton and two or three rolled bandages of old cotton, linen, or gauze also should be on hand.

Dog-bites, rat-bites, or cat-bites should always be dressed by a doctor, or made thoroughly antiseptic, mainly on account of the germs that swarm round the roots of the teeth of these animals, and also because treatment of this sort will prevent hydrophobia—although this danger is a rare and remote one, not more than a few score of deaths from mad-dog bites occurring in the whole United States in a year.

The wonderful progress made by surgery within the last twenty or thirty years has been almost entirely due to two things: first, the discovery of chloroform and ether, which will put patients to sleep, so that they do not feel the pain of even the severest and longest operation; and, second, but even more important, keeping germs of all kinds out of the wound before, during, and after the operation. That sounds simple, but it really takes an immense amount of trouble and pains in the way of baking the dressings; boiling the instruments, and scrubbing with soap, alcohol, hot water, and two or three kinds of antiseptics, or germ-killers, the hands of the surgeon and of the nurse and the body of the patient. How enormous a difference this keeping of the germs out of the wound has made may be gathered from the fact that, while in earlier days, before Lister showed us how to avoid this danger, surgeons used to lose seventy-five per cent of their amputations of the thigh, from pus infection, or blood poisoning, now they can perform a hundred operations of this sort and not lose a single case. We can open into the skull and remove tumors from the brain; open into the chest and remove bullets from the lungs, and even from the heart itself; operate in fact upon any part, or any organ, of the body with almost perfect safety and wonderful success. Whereas, before, two-thirds of the patients so operated upon would die, probably of blood poisoning.

How to Treat Bruises. Bruises are best treated either by holding the injured part under the faucet, or pump, if convenient, or by plunging it into very hot water and holding it there for ten or twelve minutes. Then if the bruise still continues to throb or ache, wrap it up lightly with a bandage of soft, loose cotton or linen cloth, and pour over it a lotion of water containing about one-fourth alcohol until the bandage is soaked, moistening it again as fast as it dries. This is also a useful treatment for wounds that have been made by a fall, or by something blunt and heavy, so that there is bruising as well as cutting. Most of the household applications for wounds or bruises, such as arnica, camphor, witch-hazel, etc., owe their virtues to the five or ten per cent of alcohol they contain, which, by evaporating, cools the wound and relieves inflammation, kills germs and so acts as an antiseptic, and cleans the wound and the skin around it very thoroughly and effectively.

Bruises of all sorts, however, unless very severe, are much safer than cuts or scratches, because they do not break the skin, and consequently no germs can get into the tissues of the blood. Our skin, as you remember, is one of the most wonderful water-proof, germ-proof, hot-and-cold-proof coatings in the world; and as long as it remains unbroken, none but a few of the most virulent disease-germs can get through it into the body.

Boils and Carbuncles, their Cause and their Cure. Boils and carbuncles are almost the only instances in which pus germs can get into the body without some actual cut, tear, or breaking of the skin. They come always from other boils or ulcers or discharging wounds and are caused by the pus germs in these either being rubbed into the skin until it is almost chafed through, or else being driven down into the mouth of one of the hair follicles, or "pores." Here they proceed to grow and form a little gathering, which soon turns to pus; and this stretches the skin and presses upon the sensitive nerves in it so as to cause much pain. The best way to treat them in the beginning is to give a thorough scrubbing with hot water and soap, and then to drop right over the point, or "head," of the gathering two or three drops of a strong antiseptic, like formalin or peroxide or carbolic acid. If this does not check them, then they had better be opened up freely with a sharp knife that has been held in boiling water, or a needle that has been held in a flame until it is red hot and allowed to cool. Then pour peroxide into the opening, put on a light dressing, and keep soaked with alcohol and water, as for a bruise. This evaporating dressing is far superior to the dirty, sticky, germ-breeding poultice. If this does not clear it up within twenty-four hours, go to a doctor and have him treat it antiseptically.

How to Stop Bleeding. If a cut should go deep enough to reach an artery the size of a knitting needle, or larger, then the blood will spurt out in jets. There is then some danger of so much blood being lost as to weaken one. Our blood, however, has a wonderful power of clotting, or clogging, round the mouth of the cut artery, so that the risk of bleeding to death, except from quite a large artery, like that of the thigh, or the armpit, is not very great.

For a wound in the hand or foot, that spurts in this way, it will usually be sufficient to grasp the arm firmly above the wrist or the elbow, or the ankle, as the case may be, with the thumb over the artery, or even to press directly over the wound, until the bleeding stops and the blood is thus given a chance to clot. If the wound is small and deep, like that made by the stab of a knife, or the slip of a chisel, then firm pressure directly over the wound itself with a thumb, or both thumbs, will usually be sufficient to stop the bleeding.



Should, however, the spurting be from an artery like that of the pulse, or from that at the bend of the elbow or the knee, then the best thing to do is to tie quickly a handkerchief or strip of tough cloth loosely around the limb above the wound and, slipping a short stick or bar into the loop, twist upon it, as shown in the picture, until the blood ceases to flow from the wound. It is much better to use a handkerchief or piece of cloth than a cord, because the latter may cut into and damage the tissues, when drawn as tight as is needed to stop the circulation. It is not best to allow a bandage twisted tight enough to stop the circulation—called a tourniquet—to remain tight for more than half an hour at a time, as this may give rise to very dangerous congestion, or serious "blood starvation" of the tissues below it. It should be gently untwisted every half hour until the arm, or limb, below it reddens up again, and then, if the spurting begins, should be tightened as before. There is, however, a good chance that if the cut artery is not too large, the blood will have clotted firmly enough in this time to stop the bleeding; though the tourniquet had better be left on the arm, ready to be tightened at a moment's notice, until the doctor comes.

The Treatment of Burns. Burns require more careful treatment on account of the wide surface of the skin usually destroyed. The layer of the skin that is most alive and most active in the process of repair is the outer layer (the epithelial, or epidermis). A burn, or scald, if at all severe, is likely to destroy almost the entire thickness of this, over its whole extent. This gives both a wide surface for the absorption of pus germs and a long delay in "skinning over," or healing. As the same heat that made the burn has usually destroyed any germs that may be present, it is not necessary to wash or clean a burn, like a wound, unless dirt has been rubbed or sprinkled into it after it has been made. The first thing to be done is to coat it over so as to shut out the air; and this, for a slight burn, can be very well done by dusting it over with baking soda or clean flour or with one of the many dusting, or talc, powders on the market, containing boracic acid, or by laying over the burn a clean cloth soaked in perfectly clean olive oil or vaseline. If the oil or vaseline is not perfectly clean, put it on the top of a stove and heat it thoroughly before using. Dress with soft, clean cotton rag or lint as before, keeping wet with the alcohol lotion (one part of alcohol to eight of water) if there be much pain, or throbbing.

If the burn is deep or the pain at all severe, it is best to call in a doctor, as bad burns are not only agonizingly painful, but also very dangerous on account of the wide, raw surface that they leave open to entrance of pus germs for days and even weeks. Until a doctor can be secured, coat it over with some non-irritating powder or oil, as for lighter burns, or hold it in warm water to exclude the air. Do not try to clean a burn. You only increase the pain of it and probably add to the risk of infection.

If your clothing ever catches fire, wrap yourself up at once in a blanket or rug to smother the flame. Remember that running will supply more air to the flame and cause it to do more damage. If you have nothing at hand in which to wrap yourself, lie down on the floor, or ground, and roll over and over until you have smothered the flame.

What should be Done in the Case of Broken Bones, or Fractures. Broken bones, or fractures, as they are called, are more serious, but fortunately not very common. They should, of course, always be treated by a doctor, to prevent shortening of the limb, or to prevent the bones from growing together at an angle, or in a bad position, so as to interfere with the use of it. Where a doctor cannot readily be had, or the patient has to be taken to him,—as, for instance, where the accident occurs out in the woods,—take two light pieces of board, or two bundles of straight twigs, or two pieces of heavy paper folded fifteen or twenty times—two folded newspapers, for instance—and, wrapping them in cloth or paper, place one on each side of the broken limb, at the same time gently pulling it straight. Then take strips of cloth, or bandage, and bind these splints gently, but firmly and snugly, the length of the limb, so that it cannot be bent in such a way as to make the ends of the bone grate against each other. The patient can then be lifted, or carried, with comparative comfort. Most fractures, or broken bones, in children or young boys or girls, heal very rapidly; and if the limb be properly straightened and splinted by competent hands, it will be practically as good and as strong as before the accident.

Sprains. Sprains are twists or wrenches, of a joint, not severe enough to "put it out," or dislocate it, or to break a bone. A mild sprain is a very trifling affair, but a severe one is exceedingly painful and very slow in healing. The best home treatment for sprains is to hold the injured joint under a stream of cold water for ten or fifteen minutes and then to bandage it firmly and thoroughly, but gently, with a long "figure-of-eight" bandage, wound many times, and to keep this moist with an alcohol lotion. Then keep the limb at rest. If the cold water does not relieve the pain, plunge the joint into water as hot as you can comfortably bear it and keep it there for ten or fifteen minutes, adding fresh hot water to keep up the temperature; then bandage as before.

If the pain should not go down under either of these treatments within six or eight, certainly within ten or twelve, hours, it is far wisest to call a doctor, because severe sprains very often mean the tearing of some important tendon or ligament, and the partial fracture of one of the bones of the joint. Unless these conditions are promptly corrected, you may be laid up for weeks, and even months, and left with a permanently damaged—that is, stiffened—joint. You will often hear it said that a sprain is harder to heal than a fracture; but that kind of sprain usually includes a fracture of some small portion of a bone, which has escaped notice and proper treatment. If the sprain is mild, so that it does not pain you when at rest, then the bandage should be removed every day, and the joint gently rubbed and massaged, and the bandage replaced again. Should there be any one in reach who understands massage, a thorough massaging right after the accident is quite helpful; but no amateur had better attempt it, as unskilled rubbing and stretching are likely to do more harm than good.

What to Do in Case of Poisoning. Poisoning is, fortunately, a rare accident; and the best thing to be done first is practically the same, no matter what poison—whether arsenic, corrosive sublimate, or carbolic acid—has been swallowed. This is to dilute the poison by filling the stomach with warm water and then to bring about vomiting as quickly as possible. This can usually be done by adding a tablespoonful of mustard to each glass of warm water drunk. If this cannot be had, or does not act within a few minutes, then thrusting the finger as far down the throat as it will go, and moving it about so as to tickle the throat, will usually start gagging; or a long feather may be dipped in oil and used in the same way. It is also a good thing to add milk or white of egg or soap to the water, or to mix a little oil or plaster scraped off the wall with it, as these tend to combine with the poison and prevent its being absorbed. If the poison happens to be an acid, like vitriol, then add a tablespoonful or more of baking soda to the hot water; if an alkali, like lye or ammonia, give half a glass of weak vinegar. The main thing, however, is to set up vomiting as quickly as possible.



Another rather frequent and most disagreeable accident, which may happen to you when out in the woods, is poisoning by poison ivy. This is due to the leaves or twigs of a plant, which many of you probably know by sight, touching your hands or face. If you do not happen to know what poison ivy looks like, you had better get some one who knows to point out the shrub to you the next time you go into the woods, and then you should try to keep as far away from it as possible. It is sometimes called poison oak, but both these names are incorrect, as the shrub is really a kind of sumac. It takes its different names because it has the curious habit of either climbing like a vine, when it is called "ivy," or growing erect like a bush, or shrub, when it is called "oak."

All sorts of absurd stories are told about the leaves of the shrub being so poisonous that it is not safe to go within ten feet of it, when the dew is on it, or to walk past it when the wind is blowing from it toward you. But these are pretty nearly pure superstitions, because it has been found that the substance in the leaves or bark of the shrub which poisons the skin is an oil, which is non-volatile, that is to say, will not give off any vapors to the air and, of course, cannot be dissolved in dew or other watery moisture. You must actually touch the leaves in order to be poisoned; but, unfortunately, this is only too easy to do without knowing it when you are scrambling through the woods or hunting for flowers or picking berries.

The remedy for poison ivy is a very simple one, and within the reach of anybody, and is as effective as it is simple. This is a thorough scrubbing of the part poisoned, just as soon as it begins to itch, with a nail-brush and soap and hot water. This makes the skin glow for a little while, but it washes out all the burning and irritating oil and, if used promptly, will usually stop the trouble then and there. It is a good idea if you know that you have touched poison ivy, or even if you have been scrambling about actively in woods or patches of brush where you know that the ivy is common, to give your hands a good washing and scrubbing with sand or mud, if there is no soap at hand, in the first stream or pool that you come to. This will usually wash off the oil before it has had time to get through the natural protective coating of the skin.

Snake-bite is one of the rarest of all accidents and not one-fiftieth as dangerous as usually believed. Not more than one person in twenty bitten by a large rattlesnake will die, and only about two in a hundred bitten by small rattlers or by copperheads. The average poisonous snake of North America cannot kill anything larger than a rabbit, and any medium-sized dog can kill a rattlesnake with perfect safety. Our horror-stricken dread of snakes is chiefly superstition. Of those who die after being bitten by North American snakes, at least half die of acute alcoholic poisoning from the whiskey poured down their throats in pints; and another fourth, from gangrene due to too tight bandaging of the limb to prevent the poison from getting into the circulation, or from pus infections of the wound from cutting it with a dirty knife. Alcohol is as great a delusion and fraud in snake-bite as in everything else; instead of being an antidote, it increases the poisoning by its depressing effect on the heart. If you should be bitten, throw a bandage round the limb, above the bite, and tighten as for a cut artery. Then make with a clean knife two free cuts, about half or three-quarters of an inch deep, through the puncture, one lengthwise and the other crosswise of the limb, and let it bleed freely. Then throw one or, if there be room, two or three other bandages round the limb, three or four inches apart, and tighten gently so as to close the surface veins by the pressure, without shutting off the flow in the arteries. After thirty or forty minutes loosen the first bandage to the same tightness and leave it so unless the heart weakens or faintness is felt, in which case tighten again. If this be done, there isn't one chance in a hundred of any serious result.