The body and its defenses

Front matter

GUL1CK HYGIENE SERIES!

BY FRANCES CUUCK JEWETT

L.n

Contents

Chapter Pack

I. Boxe and Muscle Records i

II. Danger from the School Desk 7

Introduction

In the following pages emphasis is laid on function rather than on structure, on bodily health rather than on the mere mechanical operation of bone, muscle, gland, and tissue. So much of structure is, however, included as is necessary to show that we are personally responsible for the kind of service which we receive from the organs of the body ; and that we are equally responsible for the habits of bone and muscle which determine the physical representation of ourselves to others.

Attention is drawn to right and wrong habits of sitting, of standing, and of walking; to the relation of the school desk to spinal curvature ; to laws of growth, through the knowledge of which correct habits of posture may be secured; to the value of physical exercise as an aid to general health ; to the development of muscular vigor and to the renewal of tissue through food and exercise.

By natural transition the work of the muscles leads to a study of the source of their energy, — the blood. Simple tests, easily applied, acquaint the reader with the cause of rapid and slow heart beat, with methods of training the heart to increased power, with reasons

VI why an untrained heart should not be overtaxed, with the work of the lymphatics and the nature of the exchanges made between lymph and plasma. The insidious effects of alcohol on the heart and on the entire circulatory system are emphasized.

Certain conditions of breathlessness are discussed, and reasons are given for the statement that a man runs as much with his heart and with his lungs as with his legs. In natural sequence, this explanation involves not merely the structure and the function of the lungs, but also a study of the exchange of gases both in the tissues and in the air sacs.

The notable experiments of Professor Chittenden with United States soldiers in New Haven, and of Dr. Cannon with cats in the Harvard Medical School, necessarily add a touch of picturesque reality to the otherwise prosaic subject of digestion. I hrough this introduction to the subject prominence is given to the change of food from solid to liquid form, and to its absorption by the villi ; also to the food requirements of the body under differing conditions of age and activity; to the value of bulk in the food supply; to the functions of the liver and of the kidneys, and to the influence of alcohol in undermining their power for work ; to the relation of sweat glands to bodily heat, and to the interdependence of work, heat, and fuel in the operations of the body.

INTRODUCTION vil

In close connection with the physiology of the text, several chapters discuss communicable disease and its prevention. They study tuberculosis, its cause, how to avoid it, and how to cure it ; also typhoid fever as related to pure water and clean milk ; dangers from the common drinking cup and the common towel, from the fly, the mosquito, and unsanitary surroundings; also the cause of specific epidemics and ways of escape from them through vaccination, antitoxin, cleanliness, and general physical vigor.

The closing chapters of the book are devoted to the nervous system, to its structure and its function, to methods of governing it through mental processes, and to the training of the senses.

These and other related topics have been brought to the notice of the students of this volume with the hope of imparting such enthusiasm for personal health, and such clear notions of how to secure it, that the bodies of growing children may be strengthened as well as straightened, that lives may thereby be lengthened, and that through increased physical well-being the sum of human happiness may itself be increased.

Not merely is it the purpose of this series to teach scientific facts, but also, and especially, so to arrange and present these facts that from page to page they shall hold the reader’s close attention and inspire personal loyalty to the laws of health. To further this purpose viii THE BODY AND ITS DEFENSES

side headings have intentionally been omitted, so that each chapter may make its first appeal to the reader as a unified whole rather than as a series of disjointed fragments. While the disadvantages of side headings in interrupting the continuity of thought have been avoided, all their advantages are secured through the questions at the end of the volume, which, in a better form, answer the same purpose.

In so far as possible, the instruction of this text-book is everywhere reenforced by illustrations. Special mention should be made of indebtedness to the American Journal of Physiology for illustrations used by Dr. Cannon in his article on “ The Movements of the Stomach studied by Means of the Rontgen Rays” (1898), and to Professor Chittenden for photographs of the soldiers with whom he carried on his food experiments.

Other valuable illustrations have been reproduced from Practical Hygiene by Alice Ravenhil], from The Human Mechanism by Theodore Hough and W. T. Sedgwick, from Alcohol and the Human Body by Sir Victor Horsley and Mary D. Sturge, and from Unser Korper by F. A. Schmidt. To each of these and to many other important works this little book is indebted not merely for illustrations but also for valuable facts which have been used in the preparation of its subjectmatter.

F. G. J.

Chapter I Bone And Muscle Records

f.

Many cases are on record where a man has tried to hide his face when he thought his photograph was to be taken. He has seemed to understand that the photograph might betray him some day and lead to his being arrested again.

But some of our largest cities have adopted a new and surer way of keeping a reminder of their captured men. They measure each man carefully in different directions,— height in standing and in sitting, distance from the outstretched finger tip of one hand to the outstretched finger tip of the other, length and width of head and face and right ear, length of left foot, of left middle finger, and of left forearm. Scars are noticed and recorded ; also the color of the hair and eyes, the shape of the nose, the number of teeth, etc.

In addition, the photograph is taken. And, queer though it may seem, the photograph is less important than the measurements in identifying a man if he is ever arrested again and brought to the police station. The reason is that our bone measurements change little after we are twenty-two years old. Ever after

that the size of face and head, the length of arms, of fingers, and of legs are all as they will continue to be until we die.

This, then, is a sure and sensible way of keeping the record of a man. When a criminal arrives at the police court, no matter how violently he declares that he has never been there before and that this is his first offense, the officers measure him at once and also search their written records. If they find there any set of measurements which is a duplicate of those just taken,

Taking the Length and the all the man s denials are in Width of his Head vain. Those officers kllOW that

A caliper compass is used neyer ^ twQ peop]e

been found who had precisely the same dimensions for all the bones which were measured.

It takes but ten minutes for the officers to get their record of a man — photograph and all. But it took the

BONE AND MUSCLE RECORDS man himself twenty-two years of life to make that body which is now his physical record of himself.

As a rule the body of a baby is very perfect; but even in its cradle and before it can walk a step or speak a word it begins to receive daily training of muscles and bones, of eyes and hands and brain. During these early months also older persons feel great responsibility for the child.

Notice any nurse or careful mother with the baby in her arms. See her hold a firm hand against the back of the head as she supports the backbone and holds the child up for a look at the world. She knows, as the doctor does, that for months there is more cartilage than bone in the supports of that small body, and that, while bones are in this condition, they cannot be trusted to do independent work.

Certain Indians have known this for centuries. A

Seated to be Measured

With his back against the upright scale they measure the height of his trunk famous tribe that admired flat-headed men used to secure these heads for their boys by a clever contrivance.

They simply fastened a board by a hinge to the head of the cradle and allowed it to press down upon the forehead of the baby whenever he was strapped in place. As months passed the small skull not only continued to grow

but also set itself hard and firm in the desired shape.

And once firmly set there was never any hope that the grown Indian could restore his head to the perfect shape which it had when he was born.

Thus some of our bones and muscles are trained by other people before we are old enough to make decisions for ourselves. Yet, whoever is responsible for results, two laws of bone growth should never be forgotten :

1. Many bones can be compelled to take a bend in this direction or that while the child is growing.

2. Almost no bone can be forced to make a new bend after it is twenty years old.

But there is other training which is more complex and for which we ourselves are responsible.

On a certain day two boys entered the same shop and asked for work. The first boy was refused, the second was accepted, and the explanation lay with the

The Middle Finger is measured by a Caliber Compass

BONE AND MUSCLE RECORDS bones and the muscles, which had made different records for the two bodies to which they belonged. The first boy walked with a shuffle and had a slouching body. Before he had spoken a word the business man who met him was unfavorably impressed and ready to reject him.

The second boy walked as if he respected his body thoroughly. His head was erect, his shoulders well squared, and each muscle gave the impression that he was in the habit of doing things with energy. This boy was accepted as promptly as the first was refused.

Imagine a man who needs the help of other men in carrying on some undertaking.

I hen try to picture the sort Chinook Baby in his Cradle

of body that will serve him The weight on his forehead will TUmL U 1 • heIP turn llim int0 a flat-headed

best, think how his success jndian

or his failure will be influenced by bone and muscle, by the way he stands and walks, by the way he uses his back and arms and legs and feet.

Let two women enter a store or a schoolroom, a theater or a church. Which will be served most quickly, she who shuffles as she walks, has crooked shoulders and a head thrust forward, or the woman who steps forward gracefully, who walks as if her body were her best possession, as if it were her true representative ? Surely the second woman is queen wherever she goes. Without question, at every stage of growth the body proclaims the story of what has happened to it and of all that it has done with itself since it began to live.

The point of this chapter, then, is not that police measurements of size and shape make very much difference to us, but that it is more or less within our own power, while we are growing, to make the records which are to represent us the rest of our lives.

If a man by his own acts or his own carelessness must live miserably in a shanty when he might have lived gloriously in a palace, we are apt to blame him more than we pity him.

Chapter II Danger From The School Desk

For the sake of making discoveries about yourself, stand before a mirror and study the outline of your back, your chest, your shoulders, and your legs. Try to stand precisely as you do every day at home and at school, so that you may get a correct notion of the records your bones and muscles have made for you thus far in life.

Let your eyes be keenly critical. Are you standing squarely on both feet?

Are your knees bent or straight? Is your back erect enough to hold your head up where it belongs, or does your head droop forward so that your chin sticks out too far in front? Are your shoulders on a level with each other, or is one higher than the other?

Is your chest rounded out like that of a soldier, or is it flat and curved in like a scoop between the shoulders ? Rub your hand across your back to

He stands correctly

(Copied from Practical Hygiene , by Alice Ravenhill)

see whether or not a corner of a shoulder blade reaches out like a young wing starting from the wrong place.

If you can give creditable answers to these questions, your future course is easy. Simply keep on growing as

you have begun, and when your bones are hard you will have the shape you wish. If, on the other hand, you are not perfectly satisfied with what you find, rectify each item of your posture separately, while you still look at yourself in the mirror.

Stand as nearly as you can as follows : both feet on the floor, each bearing its own share of weight; both knees stiff; both shoulders square and on a level with each other. Draw in your chin until the back of your neck would touch a stand-up collar if you had one on. Inhale a breath so full and deep that your chest looks like that of a drum major ready for his regimentals. Now your back has its correct shape for standing. It should be slightly curved in its stretch from neck downwards.

Later in the day test yourself again. You are now seated. Perhaps you are in the schoolroom. If you have time for it, take different positions and note the

He lessens his Lung Capacity

(Copied from Practical Hygiene, by Alice Ravenhill)

DANGER FROM THE SCHOOL DESK feelings in connection with each. First, sit with feet squarely on the floor, back straight, head erect, and chest raised. Are you comfortable? Can you draw a full, deep breath? Test this thoroughly.

Now slip down in your seat, curve your head forward, let your back be bent, let your chest fall in, and once more try to take a full, deep breath. Notice that here in the schoolroom, where your brain needs oxygen for its work, you have reduced your supply by the way in which you have doubled up your lungs.

For the sake of variety take another position. Sit with one elbow on the desk, or with one foot drawn up under you, or with some bend at the waist line that will give a twist to the spine near the hip. The objection to taking any one of these as the usual position is that gradually the relation of the bones to each other will be so altered as to give the body an undesirable shape. In no wise does it harm any of us to twist this

He curves his Back and crowds his Lungs

(Copied from Practical Hygiene, by Alice Ravenhill)

IO way and that, to bend as far as we can in one direction or another. Indeed, all such exercise is most wholesome, provided no one position is taken often enough, or held long enough, to become a habit.

Sidewise twists which have become permanent are receiving much attention from doctors and school examiners to-day. These men claim that although the large majority of the curves are very slight, and although most of them will, in all probability, never become serious, still it is not safe to allow a curve either to form or to increase after it is formed, because we cannot tell what the outcome may be.

Dr. F. A. Schmidt, a scientific writer in Germany, says that Dr. W. Mayer examined the backs of three hundred and thirty-six girls and found that one hundred and eighty-nine of the number had what is called lateral curvature of the spine. He found that girls between seven and thirteen years of age had much more trouble than

Curved Back and Hollow Chest

(Copied from Practical Hygiene , by Alice Ravenhill)

DANGER FROM THE SCHOOL DESK

1 1

those who were under seven, and he concluded that the habits of sitting formed at the school desk explained the difference, because the older children had spent more hours, days, and years in the schoolroom than those who were younger.

Another German investigator found that in a certain group of children eighteen per cent of the boys and forty-one per cent of the girls had these same curved spines.

This looks as if the girls of that group had been more careless than the boys in the way they sat at their desks. Or it may be that the boys had saved themselves by taking more exercise out of the schoolroom. (After Schmidt)

Follow for yourself the work of muscle and bone, and understand what happens when a child gets into the habit of sitting at his desk with elbow up on one side, shoulder lifted, and body half screwed round. Notice that

He twists his Back

If he takes the same position day after day, some of the vertebrae will finally become wedge-shaped. Habits of the school desk may thus change his shape for life if you tip lip one hip the spine curves sidewise as a balance. If you raise one shoulder it pulls the spine accordingly. Evidently each separate movement of the muscles of the back brings its result in the curves of the spine,

and the same curves, repeated day after day at the same desk, hold the bones and the cartilage which lies between them in wrong positions, until they are as truly pressed into a new shape as if the change were planned for.

So far as health is concerned, the main objection to these lateral curves is that if they are allowed to go on and become serious, they will interfere with the successful work of the large organs of the body. Then, too, when a curve becomes permanent — although it may be small — the nerves themselves are often affected by it, and the body suffers at the point which is supplied by these nerves. A person enduring this pain may not know its cause, but his ignorance will not save him from suffering.

But prevention is best of all. Children may save themselves by being careful to balance the exercises which they allow the muscles of their backs to take. All that is

Curved by the Way he is Held

If his nurse will carry him as often on one arm as on the other, no harm will be done to the vertebrae

DANGER FROM THE SCHOOL DESK needed is a little knowledge and a firm purpose. Whoever allows himself to be shaped by undesirable habits of muscle and bone will have cause for keen regret in later years. But he who, in his youth, controls his habits and shapes his body with care, will never regret it. Four rules will help:

1. Do not sit day after day in the same twisted position.

When you have been seated in one way for a while, then change and sit in some other way.

2. Do not cany a heavy weight of books on the same

arm back and forth from school every day. Carry as few books as possible on either arm, and let each arm do its share of the work.

3. Do not carry a baby brother or sister on the same hip every day. The weight just there will tend to give a wrong twist both to your back and to his.

4. If you must stand for hours at a stretch, learn to rest one leg by using the other. Don’t let one side sag down from habit. Change sides.

Notice his Shoulders

If this position becomes a habit, the boy will have a crooked body when he is a man

Chapter III Muscles Contracting And Stretching

The coal heaver round the corner has a superb set of muscles over the working part of his back. They are so well developed that, as he stands bent over his work, it

is evident that these muscles give him a back of tremendous strength. By their help he shovels coal for hours at a time through the days and the weeks of the year. Moreover, when he has finished his day’s work he does not seem overtired. He is still ready for his joke and his laugh with his children at home. He even jokes at the expense of his own back, fcr although it is so well developed and so tireless, still the man himself frankly acknowledges that it is sadly bent, and that by no effort on his part can he stand straight or walk as would please him best. He

says that that is the price he has had to pay for the

Bent by his Work

MUSCLES CONTRACTING AND STRETCHING kind of work he has chosen as a life occupation. More people have round shoulders developed in some such way than are troubled with any kind of lateral curvature of the spine.

A bicycle rider whom I know has a back quite as bent, although from a different cause. It is muscular, strong and efficient, but it never looks well except when he is working his legs fast on his wheel. It is bent from the position it has been allowed to take, rather than from the work it has done in that position.

Something must be wrong, however, and we wonder what it is.

Here are these men and multitudes of others whose backs are splendidly developed, but who are so bent as to look almost deformed.

For years no one could entirely explain the cause of the combination— the strong but bent back.

Bent by Bicycling

At last, however, close observation and logical reasoning have made the case clear. I give the explanation in the fewest words possible. T he value of this explanation will be measured for us by the use we make of the law :

i6

Muscles stay in the position in which they do their heaviest work.

A man of my acquaintance who travels a good deal, says that when, for a few weeks, he carries his suit case persistently with the same hand, that shoulder becomes an inch or an inch and a half lower than the other, while, at the same time it becomes stronger. This shows how a muscle can be lengthened even while it is being strengthened.

Stretch a muscle out and work it hard, as a coal heaver does when he curves his back over for the shoveling and the lifting of the coal, and those muscles, being obliged to work hard, even while they are stretched, will gain their strength in that position and will stay elongated even when they are not at work. Let their size and their strength increase while they are stretched and you have given them their permanent shape.

Two oarsmen illustrate this law in opposite ways. One does all his hardest rowing with a straight back, the other with a back that is curved. Their work continues day after day until each back is as strong and as muscular as the other. But see what the results are. One man walks as if he had spent his boyhood curved over a school desk without a thought about what might be happening to his spine. The other man looks as if he might have spent those same years at West Point with officers and fellow-students who compelled him to stand

MUSCLES CONTRACTING AND STRETCHING 17

straight whether he wished to or not. Yet the boyhood of the two men may have been the same. Indeed, the difference just now lies entirely with the two positions in which they did their rowing. Their muscles, when they walk, simply betray some facts about their recent history.

Look at the hand of a piano player, — it is open because he always exercises it hard in that position ; and the hand of the oarsman,

— see how his fingers curl up as if they were ready to grasp his oar even when it is not in sight. An oarsman’s hand tells the story about his occupation.

From the man who digs to earn his daily bread on the farm or in the coal mine, to the man who climbs a mast and risks his life in the tempest, — through each occupation of life the muscles of the body are called upon to do their hardest work in special positions. And it sometimes seems as if numberless human beings would have to submit to their fate and accept muscles which their work has forced on them; for after a man has chosen his life work he cannot leave it simply because he objects to the shape which it is giving to his body.

Bent by Age i8

Fortunately, however, there is a happy outlook even for such people as are obliged to work with their backs bent, for there is another important fact about this law of contracting and stretching. I give it concisely:

Brief, vigorous exercise hi the right position will undo much of the harm of long-continued exercise in the wrong position.

If a man who works in a bent posture all day will spend five minutes a day in taking vigorous exercise with his back straight, alternately tightening hard and then relaxing the muscles of his back and neck, he will find that, within one month, there will be an improvement. By this simple device a man may save himself from his rounded back and be able to hold his head where it should be.

Let the oarsman who objects to hands that curve like stiffened claws spend several minutes each day in first extending his fingers forcibly, then in relaxing them, and he will be sure to see results.

From these facts we learn that by the vigorous exercise of one set of muscles for a few minutes each day, we may be able to overcome the harm which is done by the long-continued plodding work of another group of muscles.

It often happens that the muscles of the chest become thin and flabby for lack of exercise, even while the back has become very strong. But these muscles may

MUSCLES CONTRACTING AND STRETCHING 19

be saved. Throw the shoulders well back and exercise chest muscles hard in this position. Exercise them while they are thus stretched and they will grow large and prominent in spite of what the man’s occupation may be.

In this work of changing the shape and the power of a muscle the greatest strain must be put on the last third or the last quarter of the contraction which it makes. Remember that each muscle is inclined to stay in the shape which it takes when it does its hardest work ; in other words, the law of the body is that doing a thing makes the body shape itself to that act.

Chapter IV

The audience was greatly interested, for the doctor who gave the lecture had just said that, with very little

trouble, each man present could increase the size of his arm three quarters of an inch within one month, and could increase his chest measure an inch and a half during the same length of time. Those who listened were business men, and they were specially pleased with the part of the lecture which told them how they might set to work to secure this astonishing growth

Exercise for the Biceps f ,

for themselves.

To show what he meant, the lecturer asked his friend, a medical student, to illustrate the points one by one as he himself explained them. The student was well-knit and well-built. No unnecessary fat concealed the shape of his muscles, and he was ready to show the other men what they also might do in behalf of their own development.

For a while it sounded as if the whole talk were to be a lecture on the size and shape of different muscles; for the doctor asked his friend to show his muscles one after the other in quick succession. “ Now,” said he, “ show us the effect on the biceps of rotating the arm; the forearm; now the leg, — the big muscles; show that tensor. Now again will you go through four or five exercises that bring into play in succession first one arm, then the other, and so on ?”

The student acted on the suggestions as fast as they were given. I I is smooth back and anus gave no sign of separate muscles while he stood quietly waiting to be told what to do. But as soon as he followed directions and used arm, leg, back, or shoulders, there sprang into view a succession of splendid muscles that seemed to have been lying in ambush under the skin.

In all this the student held no apparatus, but he used arms and legs as if he were pulling against some invisible weight. He was, in fact, pulling against the force of his own other muscles, — antagonistic muscles they are called. 1 ry this for yourself with your forearm or with your back. Decide to bring out one muscle and see how many others are called into action.