Hygiene for young people

Preface

The sources from which I have drawn material in writing this book have been very various. The standard physiologies of Howell, Ott, Schaffer, Stewart, Hall, Halliburton, and Hough & Sedgwick have been freely consulted. But on special topics I have made use of original monographs, or reports.

I am especially indebted to Sir Michael Foster's chapter on Sunlight; Professor F. W. Kelsey's article on The Villas of Boscoreale in the Chautauquan for May, 1906; Professor C. F. Hodge's article in The Physiological Aspects of the Liquor Problem; Sir Victor Horsley and Dr. Sturge's Alcohol and the Human Body; Sedgwick's Principles of Sanitary Science and Public Health; J. W. Seaver's Effects of Nicotine; Reports of the Massachusetts' State Board of Health, 1888 to 1895; Milk and its Relation to the Public Health; being bulletin 41, Public Health and Marine Hospital Service, Washington, D. C, 1908; Abbott, A. C, The Hygiene of Transmissible Disease; and The Life of Pasteur, by Rene Vallery-Radot.

Table Of Contents

CHAPTER

I. Sunlight and Plants .

II. Sunlight and Animals

Chapter I Sunlight And Plants

Come with me to a pine grove * such as may be seen on many a farm, and let us study the effects of sunlight upon the branches of the trees.

First, walk through the clump and notice those trees on which the living branches are close to the ground, and those on which the living branches are high up on the trunk. Notice also how far apart the trees stand from each other, and whether there are many or few branches according as the trees are near together or far apart.

If you are lucky in your choice of a grove, you will discover that when the trees are close

gether the only thriving branches are high up

♦While clumps of pine show the facts best, yet any clump of >vill <lo for this study.

Figure 1 . — Clump of old pines, lower branches gone.

on the trunk, and that many dead ones are below, all the way down. When the trees are young and far apart, the living branches are more numerous and grow out from the trunk all round. The branches extend from the top right down to the ground, and there are very few, if any, dead branches on such trees.

Notice the branching of the trees in figure 1. The central trees are almost without living limbs, excepting near the top; whereas nearly

SUNLIGHT AND PLANTS s5

Figure 2. — Clump of young pines, branched to the ground.

all the trees around the outside of the plot have living branches down almost to the ground, or, at least, much lower down than in the case of the central trees. What do you suppose has made the difference in the branching?

By way of contrast, look at this other picture of a smaller clump of pines — figure 2. In this group the pines are much younger and the full effect of the crowding of one tree upon the other has not yet become plain.

You see that every tree is encircled with green branches from top to bottom. There are no tall trunks such as you see in figure 1, and such as can be seen in every pine forest. Almost every branch which grew out from each stem has remained alive. Nature has done no pruning on these trees as yet.

But if you could wait for forty or fifty years and then examine this clump again, you would see that the same changes had taken place in it as in the older one. Limbs which had been crowded by trees near at hand would all be dead or dying. Trunks which had stretched upward above the others would all be green at the top, and would bear, on their lengthened sides, only the remains of former branches.

In short, the trees in figure 2 will in time come to resemble almost exactly those in figure 1.

Now look at figure 3. On each side of the gate stand pines which are half-way in age between those in figure 1 and those in figure 2.

Here the living branches are found overarching the driveway. The dead branches are found adjoining the neighboring trees. For some reason or other, the driveway has been

SUNLIGHT AND PLANTS

Figure 3. — Gate: Entrance to Grounds.

the means of keeping some branches alive; while, for some equally mysterious reason, the neighboring trees, closely crowding upon the pines, have lopped off many of their branches.

This is the way in which Mother Nature prunes the pine trees in <the forest, and give us the tall tapering trunks from which long straight beams of timber are made.

What has caused these differences in branching? Has sunshine or shade, heat or cold, rain or soil, air or food made the difference? The soil is the same under every tree in each of these clumps. The soil, therefore, cannot be the cause. Air encircles every pine and passes through amongst them. Air, therefore, cannot have lopped off most of the branches on some trees, while it has left them on others. There remains only the sunlight and shade as the cause of the difference. And this is the cause. When branches and leaves of evergreen trees are in the sunlight, they flourish; when they are in the shade they sicken and die.

So important is the influence of light on nearly all green plants, that the leaves are arranged on every growing stem so as to catch the greatest possible amount of light. Those that do not get a fair share sicken and die. For this reason you will find the upper leaves of the dandelion green and growing, while its under and shaded ones are brown and dying. Then, too, the dandelion by its shade kills some of the

SUNLIGHT AND TLAXTS 13

grass underneath it, and for the same reason, overarching trees kill even portions of a hedgerow.

Then again you must have noticed another way in which sunlight affects plants. Did you ever pick up a board on a grass plot in summer and find that the grass under it was almost white? In this case, there could be no doubt as to. the cause of the whiteness; because the bleached spot was exactly the size and shape of the board. Moreover, when the board was removed, the grass again became green in the course of a fewr days or a week. If the board were allowed to remain, the grass would, in the end, die.

If you look at a leaf under a microscope you will see why its color is green, but not all of it is green. The leaf seems to be made up of little bladders which you can see through. In the inside of each of the little bladders or sacs, are many small green balls, which in some plants move round and round in a clear liquid like water. It is these balls that give the greeo color to the leaf.

Now these green balls have a most important work to do for the plant. Each one is a kind of machine for making starch and sugar, and for converting the food of the plant into the woody stuffs — the root, stem and leaf — of the plant. These balls will not form without sunlight, and this is why grass becomes pale in color when kept from the light.

What lessons on health these plants could teach us, if we only knew enough to profit by them! Light helps us to make good blood, and good blood helps us to make healthy muscle and nerve; whereas shade and darkness will sooner or later make us pale and sickly.

1. What difference is there in the branching of an old tree and that of a young one of the same kind? How do you account for this difference?

2. Name some plants, or shrubs, that grow best in the shade of trees. Name some that will grow only in sunshine.

3. Where have you seen plants growing that are grayish or white in color? Do such plants grow on soil like most other plants, or do they grow on rotten wood. Do they grow in shade or in sunlight?

4. What is the cause of the green color of the leaves of most of our trees and shrubs? What is the use of the little green balls in the inside of the little bladders or sacs which make up green leaves?

5. Why do we cover up celery in sand?

SUNLIGHT AND ANIMALS 15

Chapter II Sunlight And Animals

Does light affect animals in the same way as it does plants? It would seem so. Even the shadow cast by an animal's own body is enough to affect the color of its under surface. This is seen in the fact that the hair and skin on the under surface of birds, snakes, frogs, toads, fish, and many other animals, is lighter in color than that on the sides or the back.

Does light affect human life in this way? If not, has it any effect? Look around you and see whether the faces of your friends or of strangers whom you may meet in towns and cities, are all equally ruddy or equally pale. Even a very brief look will satisfy you that they are not.

Some are ruddy, some are pale. Why the difference? Surely it must be due in part to the fact that some live much in the shade, and, like the grass under the board, have grown pale in the shade of the houses, shops, or factories in which they pass so much of the day. It would in from all those facts that light is as necesr*

Figure 4. — Solitary Tree, branched regularly all around, because all parts of it have been equally exposed to sunlight, shade and wind.

sary for the health of human beings as it is for the health of plants.

If you doubt this, consider some other facts. You find more pale people in crowded cities than in the country. People who live much in the open get their faces and hands tanned by the sun. What does tanning the skin mean? It means that the light, in striking on the skin, darkens it. As everyone knows, the skin is always paler in color under the clothing than it is where the sun shines on it. In fact, it would seem as if the color of the human skin

.

SUNLIGHT AND ANIMALS 17

varies with the strength of the sun's rays. People who live in hot climates have darker skins than those who live farther north, where the sun's rays are not so strong.

But the tanning of the skin is only part of the effect w^hich sunlight has on us. The light passes into the flesh, and affects the blood, and through the blood it affects every organ of the body.

Prisoners in dungeons always grow pale and weak. Of course, part of the cause of this is bad air and lack of exercise; but much of it is due to lack of light. Even if you lived in a large room and had plenty of fresh air and food, you would still grow pale and sickly if the room had not plenty of light. Just as green plants must have plenty of sunshine in order to convert their food into branches, leaves and fruit, so you also must live in the light to convert your food into red blood, ruddy cheeks, and healthy flesh.

Perhaps some of you may have read about men, women, and children who have lived for years, down in mines, and who never come out into the sunlight excepting for an occasional holiday. While a few people may live on in this way for years and may seem to be in fairly good health, yet such a mode of life is very unnatural and can only result in the growth of a weakly and short-lived race.

Some people have the notion that white cheeks in girls are more genteel than brown ones, and so girls are kept in the house much of the time or are made to wear gloves and veils when out in the sun. This is very wrong. But, of course, too much sunlight in very hot weather is not good for a person any more than too much salt or too much food.

Too much heat in summer may cause us to get heatstroke, or sunstroke as it is often called ; but, apart from meeting with an accident like heatstroke in the summer, there is not much danger of sunlight doing us any harm. Heatstroke, indeed, often comes upon people who are not exposed to the sun's rays at all. Not only does moderate sunlight do us no harm; it is something which we cannot do without, because it is needed for growing the little red discs which give redness to the blood and redness to the skin and flesh,

SUNLIGHT AND ANIMALS 19

There is one other important thing about direct sunlight which you should bear in mind. In warm weather it kills the invisible seeds of disease which you will read about further on. As a rule, disease germs live and flourish in darkness or in shade. Knowing this, you will see how necessary it is that sunlight should, if possible, be let into every corner of our dwelling houses. The windows in cellars should be large, as well as the windows in our living rooms, and neither of them should be screened all the time so as to keep out the sunlight.

Into the living rooms and bedrooms, sunlight should be allowed to stream freely. The curtains and carpets will, of course, become faded, but that is a small matter compared with the health of a household. Heavy curtains and carpets harbor dust and disease germs, and are therefore unhealthful. Our living rooms wrould be decidedly better without them, and in no case should their care be made an excuse for excluding sunlight.

Xot only should bedding be thoroughly aired even' day but it should be exposed to direct sunshine as well. Our houses should as far as possible face the south, and the windows should be large so as to admit plenty of sunlight. It has often been noted in recent years that many more deaths from consumption occur in shady rooms in tenement houses than in sunlit ones. Houses which are shaded by trees, and rooms which get no sunlight, are the ones which we should avoid if we go to live in a city.

1. What does tanning the skin mean?

2. The red color of the blood is due to an immense number of little red discs which float in the liquid part of the blood. How can the number of these discs be decreased? How increased?

3. How many windows are there in your schoolroom? Ask your teacher if they are large enough to let in all the sunlight that is necessary for health. Should the window blinds be kept down when the children are not in the school? Why not?

4. If sunlight is a good thing for children, should window panes be frosted in a school or home?

5. Why should bedding be put out in the sun every day? What is the effect of sunshine on disease germs?

FRESH AIR 21

CHAPTER in

FRESH AIR

Did you ever go into a house, a school, or a work-room, and find it stuffy? If you passed from one stuffy room to another you would, of course, not notice any difference; but if you passed from the fresh air and sunlight outside into a stuffy bedroom or school-house, you could hardly fail to notice the difference. You would soon say to yourself, "What an ill-smelling room!" And yet, stuffy rooms are exactly the rooms in which many people sleep at night and in which they work all day, because they are careless or do not know any better.

Some people have never learned that if they live in close rooms all day and sleep in stuffy bedrooms all night, they are starving their bodies. For we may starve our bodies in other ways than by not taking enough food. Our bodies need something besides what we eat and drink. They need something which we get from the air, and which we cannot get anywhere else.

The need for this something in the air is very pressing. You can prove this yourselves by closing your mouths tightly and holding your nostrils firmly together. How long can you keep from breathing? Perhaps for a minute or two. Sooner or later, however, do what you will, you are forced to breathe again. The flesh and blood cry out for that part of the air which we call oxygen.

If you went into a closet or a box, and closed it so that no air could pass into, or out of the box, you would learn, in another way, how strongly the blood and flesh crave oxygen. For a little while you would feel quite comfortable, but, as soon as the oxygen in the box became scanty through your using it up in breathing, you would begin to pant. And if you did not open the box and let in some fresh air, you would soon die.

How large a room, then, should we live in, in order not to suffer from lack of air? The answer to this question will depend upon a number of things. If no fresh air could get into it, we should die in a large room just the same as if we were in a box or small closet, only

FRESH AIR 23

we should live a much longer time. But if air is made to pass freely into and out of a room or a box, then we could live in either one until we died of hunger or thirst. What we must have is a constant supply of fresh air; and, if we have this, it does not matter much whether we live in a small room or a large one.

Of course, if a number of people sleep in a small room or work in a small room, you can easily see that they would use up the oxygen of the air much more quickly than if there were only a few people present. The air in such a room would need to be changed often; for, if not, the health of those in it would suffer.

At first you would notice very little change, if any. But in course of time it would be seen that overcrowding in even a large room makes the inmates pale and delicate. They would not have good rich blood, nor would they be able to digest their food properly; they would grow weak and be likely to catch some disease and die. So, overcrowding is bad for the health — overcrowding in bedrooms or overcrowding in schoolrooms or churches or factories or workshops.

There should be so much fresh air for everyone in a room that it would never be stuffy. If there are many people in a room each cannot get enough oxygen from the air, unless it is changed very often.

You will see, then, that the answer to the question, "How large a room should we live in?" depends upon two things. It depends upon how many people are in the room and upon how often the air is changed.

It may help you to understand how the air in a room may be changed, if you will perform the following experiment :

Provide two lamp chimneys and a tightly covered tin box — one that has held tea or starch will do very well. Make a hole about an inch in diameter near one end of the cover and over this hole place one of the chimneys, sealing it down with wax.

At the opposite side of the cover, punch a circle of small holes round a candle. Light the candle and bring the second chimney down over it. Fasten this chimney also to the box with wax, so that no air may pass into the box round the bottom of the chimney. Now watch what happens,

FRESH AIR

If you have arranged the apparatus properly, fresh air will pass into the box by one chimney, and foul air from the candle will go out by the other. In other words, the box will be ventilated. A piece of smoking paper over one chimney will show the direction of the air currents.

A small living room with a large family in it or a small schoolroom with many children in it, Should be Ventilated Figure 5.— Chimney over a

burning candle on a box.

in somewhat the same way.

Changing the stuffy air in a room for pure air is called ventilating the room. You might suppose that it would be an easy matter to do this, but it is not.

The chief thing is to draw fresh air into our houses and get the stuffy air out. How can we do this? In warm summer weather it is easily done. We have simply to keep our windows and doors open all the time; and, if we do, there will not be much trouble about getting plenty of oxygen for the blood. But in cold weather, it is a great deal harder to regulate. While we may feel the need of fresh air, we dislike cold air, and therefore, in winter, we close up the chinks about the doors and windows in order to keep the cold air out. But even in winter, ventilation is easy, if we have plenty of fuel to burn.

And now, a word or two about breathing. It is quite true that ordinary breathing is so natural a thing that it requires no teaching and no practice. But correct breathing is another matter. Of course you know that we should always breathe through the nose. But many of you do not know why. After we have been sitting quiet for a long time, it is a good thing to take a few quick, long breaths. This rapid breathing draws more blood into the heart, and makes the heart drive the blood more quickly all over the body, especially to the brain. After boys and girls have been studying hard for, say, half-an-hour, some breathing exercises have a first-rate effect. They rest one set of muscles and bring another set into play. They freshen up the brain, brighten the mind, and make study easier. This is why your teacher every now and again stops lessons, lets in some fresh air, and spends some time in giving you breathing exercises.

1. How can you tell that a room requires to be ventilated? What effect will stuffy air have upon people who breathe it?

2. If a room has only one window, is one opening enough to ventilate the room, or should there be at least two openings? Why?

3. How is the lamp chimney of a common coal-oil lamp ventilated? How is the same chimney ventilated, when it has a tightly fitting cork inserted in the bottom with a candle burning on it?

4. What brought the current of air into the box through the lamp chimney?

Chapter IV

The ventilation of our homes and school-houses depends chiefly upon two things, namely, upon keeping the rooms clean and upon having enough fuel.

For rooms are often musty and ill-smelling because they are not clean; and when they are not scrubbed and swept and dusted no amount of fresh air will make them smell sweet. But, if rooms are kept clean and there is plenty of fuel, there need be little trouble about ventilation.

Some of you will want to know what coal and wood have to do with the ventilation of a room. Well, they have a great deal to do with it. If you have followed me in what I have been saying, you will see that in ventilating any room in winter, the stuffy air must be let out, and the fresh air drawn in from the outside.

Often, however, this fresh air is very cold, and it must be warmed by a stove or furnace, otherwise people in the room will be very uncomfortable, and will probably catch cold and become ill. Now this warming of the fresh air costs money. It costs just the price of the wood or coal which must be burnt in order to heat the cold air and bring it up to the temperature of the living room; that is, about 67° F. as marked on your school thermometer. During cold or chilly weather ventilation costs a good deal of money; for the oftener you change the stuffy air for fresh, warmed air, the more money it costs to heat the house.

The extra expense for fuel is one reason why the houses of many poor people are so badly ventilated. They close up every chink around doors and windows, they bank the house with earth, and take great pains "to keep the cold out," forgetting that they are also keeping the pure air out and the impure air in, and that this impure air is all the time becoming more and more unfit to breathe.

To make matters worse, there may be a man in the house who smokes tobacco, and so the air is poisoned still more, for tobacco smoke is injurious especially to young children. Add to this the further fact, that the odor of burnt food is frequently spread throughout the living room, and you can easily understand that the air in such homes is as foul and ill-smelling as it can well be. No wonder the death rate is high among people who live in such homes.

To show you how heavily disease and death press upon people who live in ill-ventilated or very small houses, or wTho live crowded together in very big houses just the same as if they were in small houses, let me quote some figures from a paper by Dr. J. B. Russell, of Glasgow, Scotland, on the subject of overcrowding:

Size of house

Number of people living

in these

houses

Deaths Percentage ! per of year population

Percental

of

deaths

One room

134,728

3,636

24.7

27.0

Two rooms ....

243,691

6,325

44.7

47.0

Three rooms . . ♦ .

86,956

1,747

16.0

13.0

Four rooms . . .

32,742

6.1

4.3

Five rooms and upward

38,647

7.1

3.3

Public Institutions . .

6,531

1.4

3.2

Untraced

2.2

Whole city population 543,295 13,439 100 100

From this table you can easily see that the death rate is very high among people who live crowded together in homes of one or two rooms. Bad air is one of the causes of this high death rate.

While overcrowding is not nearly so common in this country as in Great Britain, nevertheless there are many homes in America in which the ventilation is very bad. Many women among us pass much of the daytime in two rooms — the kitchen and the living room.

Now, the air in these two rooms can be made fairly healthful by careful attention to ventilation. If the living room has a fireplace with a fire burning in it, as would be the case in winter, most of the stuffy air will pass up the

Figure G. — An open fireplace is a splendid means of ventilating chimney, and fresh air will be drawn in through the chinks between the windows and window frames, and between the doors and door frames. So the inmates will be kept warm and the room will be fairly well ventilated.

How about the ventilation at night? With only one or two people sleeping in a small bedroom, even if there is a fireplace in it, the air in the room will be very stuffy before morning, and the inmates will awake feeling dull and tired, and perhaps cross and with a headache. To avoid these bad effects, thoughtful people always sleep with the windows of their bedrooms open. If there are plenty of bedclothes, open windows can do no harm and the fresh air will do us a great deal of good. We shall wake up feeling bright, fresh, and rested.

In a schoolroom, again, especially in all old school-houses, it often happens that no pains have been taken to plan the rooms so that they can be properly ventilated. In modern school buildings, ventilating appliances are used to pump fresh air into the rooms or to suck the bad air out. But, in old fashioned buildings, other means must be used.

In all school-houses which are warmed with stoves, the window sashes should be arranged so that the upper one can be lowered from the top, and the lower one raised from the bottom. When the windows are arranged in this way, rooms can, with a little care, be fairly well ventilated. For most of the warm, stuffy air will pass out at the upper opening, and fresh air will come in at the bottom. The chief drawback to this mode of ventilation is that the pupils who sit opposite to the windows will be in a draught, and a draught is not good for anyone, especially in winter. For this reason it is better to open windows upon the sheltered side of the building, not upon the windy side.

A cold draught is air moving quickly and usually through a chink, striking on the body and cooling it. The colder the draught, the worse it is for you. If it strike your neck or uncovered head, it is likely to give you a cold, and it may perhaps make you very ill.

Now this draught can be largely avoided by fixing a board at the bottom of the window in a slanting direction, so that the cold air which comes in is thrown upwards into the room and over the heads of the pupils. The board should be about six inches wide, and as long as the width of the window. It should be fixed in the manner indicated in the accompanying diagram.