Primer of sanitation and physiology; being Primer of sanitation and Primer of physiology in one volume

Front matter

Health Service Befhesda. Md U.S Department of Health,

NLM 0S0S1S40 S

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Preface

“What you would have appear in the life of the people, that you must put into the schools,” is the substance of the advice given by a famous educator to his countrymen. The soundness of this advice has never been questioned, and the experience of the writer of this book has brought the conviction that in sanitary matters it can be applied with absolute literal¬ ness, — that our country can hope to shake off completely and permanently its burden of preventable disease only when the public schools give adequate instruction in the principles of preventive medicine and in the possibilities of public hygiene. The author has therefore followed with sympathy and very great interest the efforts that are being made to teach sanitation in the public schools, and has felt that the effectiveness of these efforts would be very greatly increased if they were supple¬ mented by an elementary text-book in this field. With this in mind he has tried to write down in a simple manner, and in a form suitable for school use, the more important facts in regard to germ diseases and their prevention. The public side of the question has been given considerable space, because the rela¬ tion of the government to the health of its citizens is an impor¬ tant and an intimate one, and because we seem destined to come into a realization of civic obligation largely through public sanitation.

In presenting the subject of physiology, the author has attempted to give the pupil a general idea of the plan and working of his body ; to make plain to him the possibilities of health ; and to point out the paths that lead to the realization of these possibilities.

The author believes that hygiene is best taught by giving a solid basis of structure and function for it. He has little confidence in get-wise-quick methods in any subject, and he has not hesitated to include sufficient physiology, with the anatomy that is needed to make it intelligible, to give an outline knowledge of the human mechanism. At the same

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IV

PREFACE time, the attempt has been made to select for treatment, from the vast field of physiology, topics that have direct and vital hygienic applications, — to teach hygiene through the modern physiology that lies behind it, rather than to teach hygiene by rule-of-thumb methods or to teach physiology for its own sake. It has been thought best at times to go somewhat far afield with the hope of widening the pupil’s hygienic horizon ; for the world is filled with people who for lack of a few large ideas are unable to use the many small ones that they have accumulated.

With the idea that children ought not to be taught the matter that is in a book of this kind because it may bring into their minds thoughts of sickness, the author is, of course, not in agreement. The real and vivid ideas of disease that are in the minds of children come not from books, but from personal ex¬ perience on beds of sickness ; from first-hand knowledge of the suffering of disease-stricken parents, brothers, and sisters ; and from the sudden vanishing of playmates and friends. As long as disease is in the lives of children, it will be in their minds, and the way to put it out of their minds is to banish it from their lives. The author has done his part in writing this book with the hope that it would do something to bring sunshine and happiness into the lives of the children that now are and are yet to be. He believes that modern hygienic knowledge is able to free our people from most of their illnesses, and that this knowledge ought to be given to the people by the schools that have been founded for their instruction.

Part I. Primer Of Sanitation Chapter Page

1. Why the Study of Disease Germs is Important i

II. The Cells of the Body . 3

III. Disease Germs and how they get into the Body 6

IV. The Struggle between the Body and the Germs ii

V. Bacteria . 18

VI. The Skin . 21

VII. The Pus-forming Bacteria . 24

VIII. Tetanus (Lockjaw) . 29

IX. The Air Passages and the Lungs 33

X. Diphtheria . 36

XI. Pneumonia . 42

XII. Influenza, Whooping Cough, and Colds . . 47

XIII. Tuberculosis . 53

XIV. The Treatment of Consumption . . . .61

XV. Dust and Germ Diseases . 71

XVI. Bacterial Diseases of the Intestine ... 76

XVII. Typhoid Fever . 77

XVIII. Diseases caused by Relatives of Typhoid Germ . 81

XIX. Other Bacterial Diseases of the Intestines . 83

XX. Disease Germs in Water . 86

XXI. Other Bacterial Diseases . 95

XXII. Protozoa . 101

XXIII. Malarial Fever and Yellow Fever . . . 103

XXIV. Mosquitoes . . . .110

XXV. Smallpox . 117

XXVI. Other Germ Diseases . 128

XXVII. Intestinal Worms . 135

XXVIII. The Importance of Sanitation . . . -141

XXIX. The Housefly . 145“

XXX. Disease Germs in Food . 15 1

XXXI. Disinfection . 158

XXXII. Unhygienic Habits . 164

XXXIII. Public Sanitation . 171

XXXIV. Governments and the Public Health . . 177 v

VI

CONTENTS

CHAPTER PAGE

XXXV. Practical Sanitation . 187

XXXVI. A New Kind of Disease Germ .... 194

XXXVII. New Discoveries in Regard to Germ Diseases . 200

' PART II. PRIMER OF PHYSIOLOGY

I. The Possibilities of Good Health . . . .213

II. The Human Body and the Cells of which it is Built 219

III. The Framework of the Body . . . . .228

TV. The Muscles and the Carriage of the Body . 238

V. The Heart and the Circulation of the Blood . 251

VI. Respiration . 265

VII. Ventilation . 272

VIII. Adenoids and Colds . 282

IX. Clothing and the Body Heat . 295

X. The Nervous System . 303

XI. The Care of the Nervous System . . . .314

XII. The Eye . 321

XIII. The Ear . 334

XIV. The Organs of Touch, Taste, and Smell . .341

XV. Foods and why we Need Them .... 347

XVI. The Digestive Organs and their Work . . -357

XVII. The Foods within the Body . 370

XVIII. Foods and Health . 378

XIX. The Teeth . 394

XX. Tobacco . . . . 409

XXI. Alcohol . 422

XXII. Accidents . 434

XXIII. Realizing Health Possibilities . 446

- XXIV. Further Facts concerning Health . . ... 455

XXV. Vitamins . 472

Appendix . 479

Pronouncing Glossary . 485

Index . 487

PART I

Chapter One Why The Study Of Disease Germs Is Important

Suppose that in a happy and healthful village a strange plant should suddenly spring up and give off poisonous matter into the air. Suppose that every one who passed by it became ill, and that all the people who lived near it died because of the deadly gases from the plant. Would the people of the village allow that plant to ripen its seeds and scatter them abroad so that in a short time plants of the same kind would be growing along all the streets and in all the dooryards ? Or would the people cut down the plant and destroy it root and branch ?

Suppose that poisonous serpents should appear in a town and should attack the people. Would the inhabit¬ ants of that town allow the serpents to live and multiply in the streets and about their houses? Or would they hunt out and kill the reptiles that were doing them so much injury ?

The people would certainly destroy both the deadly plant and the poisonous serpents, for no one would wish to suffer illness or death because of them.

Poisonous plants like the one described above do not exist, and, in most parts of the world, dangerous serpents are very rare. But in all the earth there is not a town or a village where there are not great numbers of very small plants and animals that attack the people and cause many of them to become sick and die. These small plants and animals are called disease germs, and they cause many of the worst diseases that afflict man¬ kind.

In a country where dangerous wild animals are found, the inhabitants know when they are safe and when they must be on their guard ; they know that their enemies lurk only in certain places, and by avoiding these places they are usually able to live in security and peace. But a stranger in such a land often imagines that monsters are everywhere waiting for him ; even when he is far from danger he is beset with constant fears ; and in spite of all his care he is likely to walk straight into the midst of his foes.

So a person who understands about disease germs gives little thought to them, because he knows when he is safe and how and when to guard himself from them. But per¬ sons who do not understand about germs often foolishly imagine that the world is full of them ; they live in con¬ stant fear and make many useless efforts to guard them¬ selves from them ; and then in some simple manner they allow the germs to get to them.

In this book we shall study about disease germs and how to avoid them. It is important for you to under¬ stand this subject; for a knowledge of it will often enable you to protect yourself from germs ; it will allow your mind to be at peace when there is no danger from them ; and it will help you to do your part in hastening the time when there will be no more disease germs in our land.

1. Everywhere very small plants and animals called disease germs are attacking people and causing sickness.

2. It is important for you to understand about disease germs in order to know how to escape them and avoid being frightened when there is no danger from them.

Chapter Two The Cells Of The Body

As a house is built of bricks and a heap of sand is composed of a multitude of small grains, so is the human body made up of a great number of very small parts called cells. These cells are so small that we cannot

FIG. i. When we look at a house FIG. 2. But when we stand close to from a distance we cannot see the the house, we can easily see the bricks in the walls. bricks of which it is built.

see them without a microscope, but if you could examine a small piece of skin or other part of the body under a microscope, you could very easily see the cells of which it is composed. The skin, the muscles, the liver, the stomach, the brain, and all the other body parts are built of these little cells.1

The cells are alive. Each one of the little cells of the body is alive. Each one takes in food and grows, and does all those things that make a living being different from sticks and stones and other things that are not

1 The cells of the body are exceedingly small. So small are they that it would take about 2500 of them placed side by side to make a row an inch long. There are 5,000,000 cells in a very small drop of blood, and accord¬ ing to one estimate, 400,000,000,000 cells in the average human body.

alive. When the cells are in health, the body is in healrh ; and when the cells are dead, the body is dead ; for the life of the body is in the cells of which it is built.

Fig. 3. When we look at the body, we cannot see the cells of which it is made.

But with a microscope the cells of the body are easily seen.

Keeping our bodies in health. Certain things are necessary to the cells of the body. They must have food, they must have oxygen from the air, they must get rid of their poisonous wastes, and they must have a con¬ stant temperature, neither too hot nor too cold. If our cells do not have all these things, they will die. They may be killed in other ways, too, as by being crushed, by electricity, and by poisons. To keep our bodies in health, therefore, we must supply our cells with the things that they need and we must keep poisons and other injurious substances away from them.

Disease germs. Our bodies are very wonderful ma¬ chines, but sooner or later sickness comes to most of us. Sometimes the stomach and other digestive organs fail to work properly, and then the cells suffer from a

THE CELLS OF THE BODY lack of food. Sometimes the heart and blood vessels become diseased, and then the blood fails to circulate through the body as it should. Sometimes the kidneys fail in their work, and then the cells are injured by poisonous wastes. But the most common of all causes

Fig. 4. A is a single cell as it appears under the microscope. B is a cell drawn to show that it has length, breadth, and thick¬ ness. C is a group of cells, showing how they are built together in the body.

Fig. 5. A section of the outer layer of the skin, as it appears under a microscope.

The outer cells die and fall off as dry scales.

of sickness is that disease germs get into the body and poison the cells. In the next chapter we shall learn more about these small germs and how they cause disease.

1. The human body is built of very small cells.

2. The cells are alive.

3. When the cells are in health, the body is in health, and when all the cells are dead, the body is dead.

4. The cells must have food and oxygen, and they must not be poisoned or injured in other ways, or they will die.

5. Disease germs cause sickness by poisoning the cells.

Chapter Three Disease Germs And How They Get Into The Body

Disease germs are the greatest enemies of mankind. Every day they kill thousands of people, and they cause the loss of an untold amount of time and money. To get an idea of the amount of sickness, sorrow, and loss that is caused by these small creatures, imagine a land where no colds, catarrh, consumption, influenza (grip), diphtheria, or pneumonia ever come ; a land where boils, blood poisoning, and tetanus (lockjaw) are un¬ known ; where there is no smallpox, measles, scarlet fever, whooping cough, or mumps ; a land without malaria, cholera, leprosy, yellow fever, or plague ; a land free from typhoid fever, and from many of the other diseases that afflict mankind. Picture to yourself a country and a people free from all these diseases, a country where many of the inhabitants pass from child¬ hood to old age without sickness or disease, and you will have an idea of what a land without disease germs would be like.1

What disease germs are. In water and in the soil there are millions of little plants and animals — plants and animals so small that they can be seen only with a powerful microscope. The body of one of these little plants or animals is composed of a single cell. The little one-celled plants are called bacteria (singular, bacterium). The little one-celled animals are called protozoa (singular, protozoon). Disease germs are bac¬ teria and protozoa that grow in the body and poison the cells.

1 It is within the power of man to cause all parasitic diseases to dis¬ appear from the world. — Pasteur.

DISEASE GERMS

Where disease germs come from. At this point you should get it firmly fixed in your mind that disease germs are living plants and animals ; and that just as a pine tree can come only from the seed of a pine

Fig. 6. The great outdoor world is practically free from germs.

tree, or as a chicken can come only from the egg of a chicken, so a disease germ can come only from an¬ other germ of the same kind. It is a common idea that germs spring from unclean and decaying matter — that “ filth breeds disease germs ” — but this idea is not correct. They are often found in unclean matter, and such matter is dangerous because germs may re¬ main alive in it for a long time. But germs can no more originate in such matter than a cow can come from the grass in the pasture, or a stalk of corn can spring up where no grain of corn has been planted in the earth. Nearly all the germs that attack us are spread from the bodies of persons who are sick with germ diseases.

The world not swarming with disease germs. From the very beginning of your study of this subject you should clearly understand that the world is not filled with disease germs that are lying in wait to attack us. It is true that bacteria and protozoa are abun¬ dant in water, that bacteria are swarming in the soil, and that they are constantly being blown about in the air. But of all the many hundreds of kinds of bac¬ teria and protozoa that are in the world, only a few cause disease. The others are harmless, and even when they get into our bodies, it is not we, but the bac¬ teria and protozoa, that suffer. The germs of most diseases quickly die outside the human body. It is a mistake to think that every breath of air is dan¬ gerous, and that all food and water contain disease germs. The winds that blow over the meadows, the rain that falls from the clouds, the trees of the forest, the grass in the pasture, and, in general, the great out¬ door world, are practically free from germs. In the bodies of persons who are sick from germ diseases, in the houses where sick people live, and wherever the wastes from the bodies of the sick go, there, and

DISEASE GERMS in most cases there only, are disease germs to be found.

The first great rule for the prevention of germ dis¬ eases. The first great rule for the prevention of germ diseases is : destroy the germs that come from the bodies of the sick. If all the diph¬ theria germs that come from human throats could be de¬ stroyed, there would soon be no more diphtheria. If all smallpox germs that come from the bodies of persons who have the disease could be destroyed, there would soon be no more smallpox.

It is easier to destroy germs as they come from the bodies of the sick than it is to de¬ stroy them after they have been spread abroad, and a little intelligent care used in keeping germs from being scattered would every year save millions of lives.

How germs enter the body. Except in a few cases which we shall discuss later, germs do not pass through the unbroken skin, but 7iearly all germs that enter the body get into it through wounds , or through the mouth or nose. In later chapters we shall learn what germs get into the body through cuts and sores; we shall study about biting insects (mosquitoes, flies, ticks, fleas, and bedbugs) that pierce our germ-proof armor (the skin) and place germs directly in the wounds that they make. We shall read of other germs that enter the body by

Fig. 7. The germs that attack us come from the bodies of the sick.

jro way of the nose, and we shall learn how very dangerous germs may reach the mouth from flies, from the hands, from drinking cups, in food and water, and in many other ways. Here we wish only to call your attention to the fact that wounds (many of them made by insects), the nose, and the mouth are the gateways through which disease germs get into the body.

The second great rule for the prevention of germ dis¬ eases. The second rule for the prevention of germ diseases is : take care of wounds, protect yourself from biting insects, and guard the mouth and nose. The first rule aims to keep disease germs from being scattered abroad. The second rule aims to keep out of the body the germs that do get scattered abroad. If we neglect either of these laws, we cannot hope to escape the dis¬ eases that are caused by germs.

1. Disease germs kill more than half the human race.

2. Disease germs are very small plants and animals.

3. A disease germ can spring only from another germ of the same kind.

4. Nearly all the germs that attack us come from the bodies of sick persons.

5. The first great rule for the prevention of germ diseases is : destroy the germs that come from the bodies of the sick.

6. Germs enter the body through wounds, through the nose, and through the mouth.

7. The second great rule for the prevention of germ diseases is : take care of wounds, protect yourself from biting insects , and guard the mouth and nose.

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Chapter Four The Struggle Between The Body And The Germs

In spite of the greatest care that we can take, all of us are certain at times to get disease germs into our bodies. Between these germs and the body there is then war. The germs attack the body. They try to grow in it and use it for food. To defend itself the body kills the germs. In this chapter we shall learn how the body resists its small foes.

How germs cause sickness. The germs of some diseases (diphtheria, tetanus) produce poisons that are .called toxins. These toxins are carried through the body in the blood, and cause sick- A ness by poisoning the cells. A little group of tetanus germs in a small wound, or a small patch of diphtheria germs growing in the throat, may produce enough toxin to poison and kill the whole body.

The germs of other diseases (ty¬ phoid fever, pneumonia) produce

r r . ' 1 Fig. 8. A shows the white

no free toxins ; but when the germs and b the red corpuscles

are killed and broken up, toxins of the blood 85 they aPPear

. under a microscope.

that have been produced within

them are set free, and the materials of which the germs themselves are made act as poisons to the cells. In these diseases the end of the illness comes when the germs have all been killed, but the faster they are de¬ stroyed the more severe for the time will the disease be.

How the body destroys toxins. One way in which the body protects itself against germs is by producing anti¬ toxins. When disease germs grow in the body and begin to poison it with toxin, the body begins to produce antitoxin. The antitoxin does not kill the germs , but it does destroy the toxin , and thus saves the cells from being poisoned until in other ways the body can kill out the germs.1

How the body kills germs. If you should examine a drop of blood with a microscope, you would find a very great number of cells floating in the liquid part of the

Fig. 9. A white corpuscle taking in a bacterium.

blood (Fig. 8). These cells are of two kinds. Most of them are red in color, and these are called red corpuscles. Their work is to carry oxygen through the body. The other kind of cells in the blood are the white corpuscles. These are the soldiers of the body, and their work is to kill disease germs.

A white corpuscle approaches a germ and flows about it, or swallows it, as you see in Figure 9. Then the corpuscle tries to digest and kill the germ, while the germ tries to grow in the corpuscle and use it for food. When the corpuscles are victorious, the germs are destroyed and the disease is stopped. But if the germs are too numerous and too powerful, the corpuscles are killed, and the disease goes on until the body dies.

1 There is a different toxin and antitoxin in each different germ disease. The toxin and antitoxin of diphtheria, for example, are different from the toxin and antitoxin of tetanus or of typhoid fever.

STRUGGLE BETWEEN BODY AND GERMS 13

Besides the white corpuscles, there is another great defender of the body, the germicidal (“ germ-killing ”) substance of the blood. There is always some of this substance in the blood of a healthy person, and when disease germs attack the body, more of the germicidal substance appears in the blood and helps to kill them. In our fight against the germs this germicidal substance is perhaps even more important than the white corpuscles.1

Why we have certain diseases only once. When germs attack us, the body manufactures more of its germicidal substances to kill them. More and more of the germi¬ cidal substance is formed, and the blood becomes stronger and stronger in its power to kill germs. Finally, if the body is successful in its struggle with its enemies, the germicidal substance and the white corpuscles get the ‘upper hand of the germs and recovery begins. After a patient recovers from some diseases (for example, small¬ pox, measles, and whooping cough), a large amount of germicidal substance remains in the blood for years, or even for life. Any germs of these diseases that get into the blood are therefore promptly killed, and a person is seldom attacked by one of these diseases more than once. Cases of infantile paralysis, pneumonia, small¬ pox, and many other infectious diseases are treated with blood from a person who has recovered from the disease. Why could such blood be expected to kill the germs ?

1 The body produces different germicidal substances in killing the germs of different diseases, just as different toxins and antitoxins are pro¬ duced in different diseases. A person therefore may have a great power of killing the germs of one disease, as, for example, smallpox, and at the jame time fall an easy victim to some other disease, as consumption.

PRIMER OF SANITATIOAT

Keeping up the resistance of the body to germs.

Through all your study of germ diseases you should bear in mind the importance of keeping up the germi¬ cidal power of the body. All of us, without knowing it,

Fig. io. Dry feet, fresh air, and plenty of sleep help to keep up the power of the body to kill germs.

take into our bodies the germs of deadly diseases. As the seeds of plants lie in the cold earth waiting for the warmth of spring to come, so these germs often lie in the body waiting for a chance to grow. The only safe way, therefore, is to keep the body always in health, so that it will be able to kill any disease germs that may enter it. Overwork, exposure to cold,' wet feet, hunger, fatigue, worry, lack of fresh air, lack of sleep, alcohol — all of these things injure the body and lower its germi¬ cidal power. It is the duty of every one to keep himself in health — to care for his body intelligently and care¬ fully — and to fail to do this is no more sensible than it would be sensible for the soldiers in a fort to open the gates and lie down to sleep in the midst of their enemies.

Alcohol and resistance to germs. Experiments on ani¬ mals prove that alcohol lessens the power of the body

STRUGGLE BETWEEN BODY AND GERMS 15 to kill germs. When alcohol is given to rabbits it is not possible to save them from rabies (hydrophobia) by the Pasteur treatment (page 129). Other experiments show that the germs which cause boils and blood poisoning are able to attack rabbits that have had alcohol more easily than they can attack rabbits that have had no alcohol. Still other experiments show that animals which have been given alcohol cannot resist the germs of cholera, tetanus (lockjaw), and other diseases so well as animals which have not been given alcohol. Experi¬ ments like these leave no room to doubt that alcohol taken into the body lessens the power of the blood to kill germs.

Many physicians have long believed that this was true, for they have known that drinkers suffer far more from many germ diseases than do those who use no alcohol. A spell of drinking often brings on an attack of pneumonia, and the death rate from pneumonia is very high among drinkers. Consumption is also very common among drinkers, the records of one foreign life insurance company showing a consumption death rate more than five times as high among brewers as among Protestant ministers. Wounds heal less rapidly in users of alcohol than in abstainers, and the inflammation is more likely to run on into blood poisoning in a drinker. So in cholera and typhoid fever it is the drinkers who suffer most, and there is every reason to believe that this is the case in all germ diseases. Drink no alcohol if you wish to keep up the power of your body to resist germs, for users of alcohol are attacked by germ diseases more frequently than abstainers, and many of them die of these diseases when they are attacked.

1 6

The third great rule for the prevention of germ diseases.

The third great rule for the prevention of germ diseases is : keep the body in health , so that it will be able to kill disease germs. A general does not risk the fate of his army on a single battle line, but behind the first line of soldiers he places a second line, and behind the second line he has still a third line of defense in case the enemy