How WE LIVE 
OR 
THE HUMAN BODY 
AND HOW TO TAKE CARE OF IT HOW WE LIVE: 
OR, 
THE HUMAN BODY, AND HOW TO 
TAKE CARE OF IT. 
AN ELEMENTARY COURSE IN ANATOMY, 
PHYSIOLOGY, AND HYGIENE. 
JAMES TOHONNOT 
BY 
AND 
EUGENE BOUTON, Ph. D. 
REVISED AND APPROVED BY 
professor of the principles and practice of medicine in the college 
OF MEDICINE, SYRACUSE UNIVERSITY J EX-PRESIDENT OF THE MEDICAL. SOCIETY 
OF NEW YORK, AND OF THE NEW YORK STATE MEDICAL 
" MEMBER OF THE BRITISH MEDICAL ASSOCIATION. 
HENRY D. DIDAMA, M.D., 
NEWYORK : 
D. APPLETON AND COMPANY, 
X, 3, AND 5 BOND STREET. 
1886. Copyright, 1884, 1885. 
D. APPLETON AND COMPANY. WHY AND HOW. 
For a long time the conviction has been grow- 
ing that there is a radical defect in an elementary 
course of study which admits technical grammar, 
but excludes physiology, and which makes more of 
the classifications of expression than of the thought 
to be expressed. The urgent need has long been 
felt of giving more attention to subjects pertaining 
to life, those that may be a guide to thrift, health, 
and happiness. 
These convictions seem to have been shared by 
the law-makers of New York and several other 
States. The recent enactments making physiology 
a part of the course of instruction in the public 
schools are evidences of'this conviction; and from 
Legislative Action. 
every point of view the measures appear wise and 
beneficent. 
If wisely carried out, this law must be pro- WHY AND HOW. 
4 
ductive of great good. The attention of pupils 
will be directed to the laws which govern their 
own being. The truths set forth will find lodg- 
ment in the brain, and in time they will find ex- 
pression in daily practice. As a result, we may 
look for improvements in food, in dress, in venti- 
lation, in habits, in hours of work and recreation, 
and in everything that pertains to living. 
Plan of the Book. 
The manifest importance of the subject is the 
“ why ” of the book. The “ how ” remains to be 
considered. 
The book is elementary, not a scientific treatise 
for advanced students. Beginning with obvious 
relations, its method is inductive, each new topic 
growing out of the one that precedes it. It aims to 
present the laws of life in such a practical and rea- 
sonable way that they will become a guide to living. 
In the treatment of each topic, function is con- 
sidered before structure. The first step is to show 
that, for purposes of life and growth, there is a 
need. Then, in answer to the query as to what is 
done to satisfy the need, a full description is given 
of the organs used and the methods employed. 
This properly subordinates structure to use, and 
shows the true relations of all the agencies of life. WHY AND HOW. 
5 
The limitations set by the term “elementary” 
have forbidden minute details, abstruse discussions, 
and ultimate analyses. All these are left for the 
“ High-School Physiology.” 
Hygienic Laws. 
An endeavor has been made to present the rela- 
tions of part to function in such a way that the 
hygienic law applicable to the case follows as a 
matter of course, and scarcely needs to be stated. 
A law derived in this way compels assent and com- 
mands obedience; while one learned from the book 
is likely to remain in the mind as a mere formula. 
At the close of each chapter a list of questions 
is appended, not on the text, but rather on subjects 
which the text suggests. The answers to these 
questions will test the pupil’s powers of inference, 
and will incite to careful observation and study in 
various directions. When the questions are not 
matters of mere inference, one at a time should be 
given out at the close of each recitation, so as to 
allow ample time for inquiry and study. The 
good which will come from a judicious use of 
these topics may be lost by a rigid demand for a 
specific answer in a specified time. 
Incentives to Study. 6 
WHY AND HOW. 
Alcohol and Narcotics. 
The provision in the new laws in regard to al- 
cohol and narcotics seems to be another wise and 
timely measure. It assumes that bad habits are 
largely due to ignorance. It would diminish the 
evils by removing the cause. It submits the solu- 
tion of a great social problem to science. It es- 
pouses no theories, but demands the exact truth. 
It calls upon the teacher to furnish the weapons 
that shall conquer prejudice, and arm the inexperi- 
enced against temptation. 
In this work, alcohol and narcotics, in their rela- 
tions to life, are duly treated. Wherever they are 
found in the body, their effects upon organ and 
function are fully described. These effects, on the 
whole, are seen to be so pernicious that a knowl- 
edge of them would seem to be an almost sufficient 
safeguard against evil example, which is continually 
inciting to evil habits. 
The.error of over-statement has, however, been 
carefully avoided. Assertion without reason weak- 
ens a cause. The facts are sufficient. A serious 
mistake is made when the suspicion is aroused that 
an effort is made to establish a case, rather than to 
ascertain and state the truth. WHY AND HOW. 
7 
Practical Application. 
This and all kindred works will be of little use 
if thought stops with the text. What is said is 
valuable only as it “ wakes up mind,” and leads to 
further study, and to the observance of hygienic 
laws in daily practices. The teacher who allows 
his pupils to sit in draughts, and pays no heed to 
ventilation and the arrangement of light, and who 
is careless in regard to his own diet, dress, and 
hours of sleep, will teach physiology to little pur- 
pose. 
The pupils should be made to see, to study, and 
to experiment. The word should lead to work. 
Principles should direct practices. The under- 
standing of conditions must precede conscious obe- 
dience to law, but obedience is the desired end. 
Full mental conception of the subject in its rela- 
tions will, in time, yield fruit in the direction of 
more healthful bodies, more vigorous minds, and 
lives made richer by the accomplishment of good 
deeds. WHAT AND WHERE, 
CHAPTER I. 
FACE 
The Body and its Parts 13 
Why we should Study our Bodies : Some Things 
easily seen—Others require Study—Natural to avoid injur- 
ing Outward Parts of the Body—Study needed to know how 
to take care of Organs within the Body—Why we should look 
well and keep healthy. About Parts of the Body ; 
The Arms—The Legs—The Limbs and Joints—Parts of the 
Body in Pairs—The Bodies of other Animals—Uses of the 
Parts of the Body. Something to Find Out. 
CHAPTER 11. 
Eating, and what Comes of It 21 
Why we Eat ; The Body always wearing out—We eat 
that we may live. What we Eat : Kinds of Food—Value 
of Different Kinds—Special Foods—Mixed Foods. How we 
Eat : Mastication—The Teeth—Care of the Teeth—How to 
keep the Teeth clean. How we Swallow : How Saliva 
flows—Amount of Saliva—How Saliva is wasted—Tobacco 
—The Esophagus. Hygiene of Mastication. Some- 
thing to Find Out. 
How Digestion Goes On 35 
CHAPTER HI. 
The Stomach : Structure—Muscular Action—Gastric 
Juice—Changes in the Stomach—Chyme—The Absorbents— WHAT AND WHERE. 
PAGE 
Drink—Alcohol in the Stomach—Absorbing Power—The 
Alcohol Habit. The Intestines : Structure—Intestinal 
Juices—The Duodenum—The Pancreas—Office of the Pan- 
creatic Juice—The Liver—Bile—Office of the Bile—Chyle—• 
Alcohol in the Liver—Absorption—The Portal System—The 
Lacteals—The Thoracic Duct—Summary of Changes. Hy- 
giene of Digestion. Something to Find Out. 
CHAPTER IV. 
How the Blood gets Purified 46 
The Heart; Its Position—The Plan of the Heart— 
Auricles and Ventricles—Pulmonary Action. The Lungs : 
Structure of the Lungs—Bronchial Tubes—The Trachea— 
The Larynx—The Pleura—How the Chest varies—Forces in 
Breathing—lnspiration—Expiration—Action in the Lungs— 
Results of Breathing—Return of tire Blood—Alcohol in the 
Lungs—An Unnecessary Burden—Tobacco in the Lungs— 
Produces Stupor—The Need of Pure Air. Hygiene of 
Respiration. Something to Find Out. 
How the Blood Nurtures the Body , . . .58 
CHAPTER V. 
Waste and Repair—The Arteries—The Capillaries—The 
Veins—Action in the Heart—Action in the Arteries—Action 
in the Capillaries—Action in the Veins—Alcohol in the Blood 
—Does not become a Part of the Blood—Hinders the Effect 
of Oxygen—lnjures the Walls of the Heart—Enlarges Mi- 
nute Divisions of the Arteries. Hygiene of Circulation. 
Something to Find Out. 
How the Body is Able to Move 66 
CHAPTER VI. 
Motion necessary to Life. The Muscles: General 
Structure—Connective Tissue—’Parts of Muscles—Tendons— 
Hollow Muscles—How the Muscles act—Voluntary and In- 
voluntary M uscles—Flexors and Extensors—How the Muscles WHAT AND WHERE. 
11 
PAGE 
gain Strength—The Muscles need Rest—Exercise for Health, 
not for Strength. Hygiene of the Muscles. Something 
to Find Out. 
CHAPTER VII. 
How the Body is Able to Stand . . . .77 
The Need of a Bodily Frame. The Bones : Uses of the 
Hones—Forms of Bones—Structure of the Bones—Materials 
of which the Bones are made—Growth and Repair of the 
Bones—Bones of the Head—Sutures of the Skull—Bones of 
the Trunk—Bones of the Arms—Bones of the Legs—Bony 
Cavities of the Body. Bodily Movements ; How the Mus- 
cles move the Bones—How Shocks are distributed. Hygi- 
ene of the Bones. Something to Find Out. 
How the Body is Covered 91 
CHAPTER VIII. 
The Usefulness of the Bodily Covering. The Skin: 
General Structure of the Skin—Layers of the Skin—How the 
Skin is kept soft—How the Skin casts out Waste Matter— 
How the Skin regulates Heat—Flow the Skin absorbs— 
Why the Skin should be kept clean—How to keep the Skin 
clean. The Hair; What it is—How to keep the Hair 
healthy—Thinning and Grayness of the Hair. Clothing: 
Why the Body should be clothed—Flow the Body should be 
clothed. Hygiene of the Skin. Something to Find 
Out. 
CHAPTER IX. 
How Bodily Motion is Directed 107 
Bodily Organs must act in Harmony. The Nervous 
System; How the Nerves are distributed—Nerve-Matter— 
The Brain—The Spinal Cord—The Ganglions—Sympathetic 
System—Use of the Nerves—Direct Nerve-Action—Reflex 
Action—Sympathetic Action—Habit and Training—Exercise 
of the Nerves—Rest of the Nerves—How Alcohol affects the 
Nerves—Staggering—Effect on the Mind—The Lower Na- WHAT AND WHERE. 
12 
PAGE 
ture in Control—How Tobacco affects the Nerves—Inherit- 
ance. Hygiene of the Nerves. Something to Find 
Out. 
CHAPTER X. 
How the Mind gets Ideas and Expresses Them . 122 
Sensations—The Need of Special Senses. The Sense of 
Taste : The Taste as a Sentinel—Flavors—Taste not a Per- 
fect Guide in the Choice of Foods. The Sense of Smell; 
Odors. The Sense of Hearing: Sound—lts Production 
—The Ear—Care of the Ear. The Sense of Seeing: 
Light—Need of Light—The Eye—lts Structure—Muscles of 
the Eye—Action of Light—Care of the Eye. The Organs 
of Speech : The Need of Expression—The Voice—Speech 
—Care of the Voice. Hygiene of the Organs of Special 
Sense. Something to Find Out. 
CHAPTER XI. 
Stimulants and Narcotics 137 
1. Stimulants: Unnecessary—lnjurious. 2. Narcotics. 
What the Words Mean 141 
Topical Analysis 156 
Bones of the Body 166 
Where to Find Things 169 HOW WE LIVE. 
CHAPTER I. 
THE BODY AND ITS PARTS. 
Why we should Study our Bodies. 
When we look at our bodies, we see that they 
are made up of parts. Each of these parts has a 
name and one or more uses. We know the most 
common of these names and uses; but, unless we 
have studied them with care, there are many im- 
portant and interesting things about them that we 
do not know. 
If any one should ask us the name of the highest 
part of the body when standing erect, we would 
answer that it is the head. We could also tell the 
names and the uses of the outer parts of the head. 
Perhaps we could make pictures of them. 
We would, likewise, be able to tell that the part 
of the body next below the head is the neck; that 
the largest part of the body is the trunk; that the 
parts attached to the upper portion of the trunk 
are the arms ; and that those attached to the lower 
portion of it are the legs. 
But, if some one should ask us about what is 
inside of the head, neck, or trunk, we would be un- 14 
HOW WE LIVE. 
able to answer from observation, and we could not 
tell either the names or the uses of the parts. Yet 
each of these inside organs has a work to do in the 
support of life; and the peculiar work which each 
does and its curious way of doing it are matters of 
great interest. 
When a bee stings us, or we burn our fingers, 
we can tell the cause of the pain ; and we shall be 
careful to avoid it in the future. But when we 
have earache or headache, we can not always tell 
the cause. By the study of those parts of the body 
which we can not see, we may so change our course 
of conduct as to avoid many aches and diseases. 
If we see a person’s tooth broken off, or his eye 
blinded by some accident, we shall never know- 
ingly expose ourselves to the same danger ; yet, by 
want of knowledge, we may neglect or abuse our 
teeth or eyes in such a way that they will be as 
surely destroyed as by a visible accident. 
Most of the internal organs are soft and deli- 
cate ; and when once injured they are afterward, in 
many cases, weak and nearly useless. By knowing 
what care they need, we may avoid injuring them, 
and so escape pain and disease. 
It is necessary, therefore, that we should know 
a great deal about the parts of the body. We 
should know not only their names and uses, but 
also what will make them stronger or weaker. 
Then we shall know how to preserve our health, 
and thus be able to keep ourselves in the best con- 
dition to do our work in the world. 
Looks are important. We like to see good- THE BODY AND ITS PARTS. 
15 
looking people. We should desire to look well, so 
that our appearance will please others. One of the 
most important elements of good looks is health. 
A sickly person loses that clearness of complexion, 
that sparkle of the eye, and that elasticity of step 
and vigor of motion which we all admire. 
By keeping in health we also enjoy life much 
better. We suffer less from bodily pain; we see 
things more clearly, and succeed better in what we 
undertake ; we can take care of ourselves, and thus 
avoid becoming a burden to our friends; and we 
are more ready to perform any duty that may pre- 
sent itself. Besides, we are more cheerful. We do 
not take gloomy views of life, and make ourselves 
generally disagreeable; and, while we are happier 
ourselves, we make others happier also. 
About Parts of the Body. 
The Arms.—We see that the arms form a pair, 
and are fastened sidewise to the trunk just below 
the neck. They extend in opposite directions, and 
end in hands, which continue in the same direction 
as the arms. The hands terminate in fingers, and 
the ends of the fingers are protected by nails. 
The Legs.—The legs are joined to the lower 
part of the trunk and extend downward, ending in 
feet, which are at right angles to the legs. At one 
extremity the foot has a heel, and at the other it 
terminates in toes, which, like the fingers, are pro- 
tected by nails. 
The Limbs and Joints.—The arms and legs 
when taken together are called limbs. All the 16 
HOW WE LIVE. 
limbs are attached to the body in such a way that 
they can move in every direction. The point of at- 
tachment is called a joint. 
If we examine a leg of mutton, or the leg of a 
chicken, which we may have on the table at dinner, 
we find in each a bone 
with a round head fitting 
into another bone having 
a cup-like cavity. These 
bones form what is called 
the ball-and-socket joint. 
Such a joint we have 
at the shoulders and the 
hips, where the arms and 
the legs are attached to 
the body. The sockets 
at the shoulders are not 
so deep as those at the 
hips, and this arrange- 
ment allows the arms 
much greater freedom of movement. 
We see that a door is attached to the jamb in 
such a way that it can swing in only two direc- 
tions, backward and forward. This kind of attach- 
ment is called a hinge. The arms at the elbows, 
and the legs at the knees, have only a forward and 
backward movement, and hence these joints are 
called hinge-joints. 
The double or compound joints at the wrists 
and the ankles admit of a great variety of move- 
ments, and are made up of several small, rounded 
bones which move about each other. The knuckles 
Fig. i.—Ball-and-socket joint of 
the hip. THE BODY AND ITS PARTS. 
17 
and the toe-joints, like those of the elbows and the 
knees, are hinge-joints. 
The lower parts of the arms 
and legs have also a turning or 
twisting motion, so that we can 
turn our hands completely over 
and our feet in and out. This 
motion is brought about in the 
arm by an arrangement of two 
bones which extend through the 
lower part of the limb, and which 
turn about one another. 
Parts of the Body in Pairs. 
—Besides the pairs of arms and 
of legs, we have two ears, two 
eyes, and two cheeks. If we 
examine closely, we shall see that the nose has two 
nostrils, and that the two sides of the mouth are 
alike in structure. This arrangement of the exter- 
nal parts of the body in pairs makes it double; so 
that, if it were divided by a line running down from 
the middle of the forehead, it would be in halves, each 
with the same parts turned in opposite directions. 
The Bodies of other Animals.—If we examine 
other animals, we shall see the same general plan 
of structure—parts in pairs, and opposite sides alike. 
The parts of other animals correspond to parts of 
our own bodies in many respects, agreeing in num- 
ber, position, and general use, but differing some- 
what in form. Thus the cat and the dog have four 
limbs each : but their arms are fore-legs; their 
hands, paws; and their nails, claws. 
Fig. 2.—Hinge - joint of 
the elbow. HOW WE LIVE. 
The horse and the cow also have four limbs 
each ; but, in the place of toes, the horse has a sin- 
gle hoof, and the cow a double one. The chicken’s 
arms are wings ; the bat’s four limbs are connected 
by a thin, delicate skin, forming wings with which 
it can fly ; the frog’s four limbs terminate in webbed 
feet for swimming; the whale’s four limbs are flip- 
pers; the fish’s four limbs are fins; and even some 
snakes, under their skin, have four tiny legs, which 
never grow so as to become of use to them in get- 
ting about. 
Uses of the Parts of the Body.—ln each one of 
us the part that thinks, or the mind, is the most im- 
portant. The mind in thinking makes direct use of 
the brain. The brain is in the head, and is pro- 
tected by the skull. 
Every time the mind thinks, a tiny part of the 
brain wears out and must be repaired. The ma- 
terials for the repair come from the blood. Hence 
we must have a way of making blood. For this pur- 
pose we have a trunk; and this is large, so that it 
may contain everything necessary for the process. 
To make blood, we must have food ; and to get 
food, we have arms to reach out and take it, and 
legs to go in search of it. We thus see that all the 
parts are made expressly for the service of the 
mind ; and that by their proper action alone can 
the mind be kept in good condition. One would 
think, then, that the mind, if it is sensible, would 
take good care of the body. THE BODY AND ITS PARTS. 
Something to Find Out. 
I. Why should we try to look as well as we 
can ? 
2. What are some of the things necessary to 
good looks that we all can attend to ? 
3. Which of the ball-and-socket joints are most 
easily put out of joint? Wh}T? 
4. What kind of joint unites the thumb to the 
hand ? 
5. How many joints have the fingers ? the toes? 
6. How does the great-toe differ from the thumb? 
8. How do the cat’s toes correspond in number 
to our fingers and toes ? 
7. How does the ankle differ from the wrist? 
9. How do the cat’s fore-paws differ from our 
hands ? 
10. What joint in the dog’s hind-legs corre- 
sponds to our hips? knees? ankles? 
11. What bone in the cat’s leg represents our 
heel? 
12, On what part of the foot do we tread? On 
what part does the dog tread ? 
13. Explain what is meant by the term digiti- 
grade—plantigrade. 
14. Give two examples of digitigrade animals— 
of plantigrades. 
15. To which of these classes does the horse 
belong? the cow? the sheep? the bear? the ele- 
phant ? 
16, Why are the bones of the skull made very 
strong ? 20 
HOW WE LIVE. 
17- What animals use their fore-paws to hold 
their food while eating ? 
18. How does the duck’s foot differ from that 
of a chicken ? 
19. What do birds have in the place of mouth 
and nose ? 
20. In what way can we best avoid mistakes in 
taking care of the body ? 
Note.—At the latter end of the book, commencing on page 156, 
will be found a topical analysis for each general subject treated in the 
several chapters. These outline statements may be made of great 
value to teacher and pupil, as showing the relations of the topics and 
sub-topics to each other, and as affording a scientific basis for exami- 
nations and reviews. CHAPTER 11. 
EATING, AND WHAT COMES OF IT. 
Why we Eat. 
Every motion that we make, and every thought 
that we think, destroys some of the minute cells of 
which the various parts of the body are composed. 
If this waste goes on without repair, the parts soon 
wear out, and the body dies. The process of re- 
pair is called nurture, and the elements of nurture 
are found in food. 
Before the food can nurture the body, it must 
undergo many changes. It must be broken up; 
parts of it must be dissolved ; different parts must 
be mixed with each other; and the useful parts 
must be separated from those which are worthless. 
The first step in this process is eating. We eat, 
then, that we may live. We eat, that every part of 
our bodies may be strengthened, and that we may 
be able to do our daily work. 
What we Eat. 
Upon our tables, for breakfast or dinner, we 
have meat, bread, potatoes, fish, fruit, and many 
other articles of food to eat; and water, milk, and 22 
HOW WE LIVE. 
other liquids to drink.* We must take this food 
and drink at regular times, to satisfy the demands 
of appetite and the needs of the system. 
As the body is composed of many different ele- 
ments, the food and drink which we take must con- 
tain these elements. If we take no food, we starve ; 
if we take food that lacks some needed element, 
after a time we starve just as certainly. 
More of the elements which the body needs are 
found in some articles of food than in others. But, 
as no one food contains all kinds and sufficient 
quantities of needed elements, we are obliged to 
take a variety of foods—one kind furnishing the 
elements which the others lack. 
Kinds of Food.—One of the most valuable of all 
the foods is the gluten, or sticky part, of flour. It 
contains all the elements which the body needs, but 
not all of them in sufficient quantity.f Nearly the 
same elements are found in the albumen, or white, 
* The pupil should here enumerate the different kinds of food in 
common use, and find out all he can about each. For example : bread 
is made of wheat ; the wheat grows in our fields ; the grain is taken 
to the mill and ground ; and the meal or flour is made into bread. This 
treatment of the subject serves to introduce both farming and manu- 
facturing operations, and to show their relation to our needs. 
Again, take rice, another common article of food. This grain does 
not grow in our fields, but is the product of a warm, lowland region. 
The description of its place and manner of growth serves to show the 
relations of food to geography, and to give a new and vital interest to 
that branch of study. In like manner, tea, coffee, sugar, salt, and many 
other articles may be made to serve a similar purpose 
f Wheat, the most valuable of our grains, contains a large amount 
of gluten. Fine white flour contains little gluten, and, when we make 
bread of it, we lose the best part of the grain. The “ new-process " 
flour retains the gluten, and makes excellent bread. EATING, AND WHAT COMES OF IT. 
23 
of eggs ; in the fibrine, which is the principal part of 
lean meat; in the caseine, or curds, of which cheese 
is made; and in the gelatine which comes out of 
meat and bones. These foods are known as proteids, 
or albuminoids. 
Another substance of great value as food is the 
starch that forms a large part of the grains and 
other vegetable products. Starch does not, how- 
ever, contain so many of the needed elements as 
gluten, and is therefore less valuable as food. Near- 
ly the same elements which enter into starch are 
found in sugar and in the vegetable gums. These 
foods are known as amyloids,* 
The third class of foods includes all oily sub- 
stances, both animal and vegetable, and are known 
as fats. They are composed of nearly the same 
elements as starch and sugar, but they so differ in 
form that they need a different treatment before 
they can nourish the body.f 
Minerals form the fourth class of substances that 
may be ranked as foods. They include lime, soda, 
potash, iron, salt, and water. These are all found 
* Starch forms a large part of all the grains. Potatoes contain but 
little besides starch and water. Peas and beans are more than half 
starch. Tapioca, sago, arrowroot, and rice are nearly all starch. Beets, 
turnips, and other garden vegetables are principally made up of starch, 
sugar, and water. 
f All the kinds of food given above not only furnish the elements 
of nurture, but each helps to furnish the heat necessary for the well- 
being of the body. But, while the proteids are best for nurture, they 
have the least of the heat-producing power. The amyloids have great 
power of producing heat, but the fats have still greater. In the frozen 
regions of the extreme north, oil is one of the most necessary articles 
of diet. HOW WE LIVE. 
24 
in the body, and must be contained in the different 
articles of food. These substances, with the excep- 
tion of salt, are found in sufficient quantities in meat, 
in fruit, and in vegetables. 
Special Foods.—Of the vegetable foods, wheat- 
flour and oatmeal contain the greatest number of 
needed elements, and come the nearest to perfect 
foods. Corn-meal is rich in starch and fats, but has 
little gluten. Peas and beans have a large portion 
of vegetable caseine, a substance that resembles glu- 
ten, and they are ranked very high as foods. As 
they are not easily digested, however, they should 
be taken only in small quantities by those who have 
weak stomachs.* 
Beef is the best of all the kinds of meat. Next 
to this comes mutton. Chicken and turkey have 
nearly the same elements, with the exception of the 
fats. Veal, lamb, and pork have less of the elements 
which the body needs, and are harder to digest. 
Eggs and milk are nearly perfect foods. Fish and 
oysters are among the best of foods. Clams, crabs, 
and lobsters are less easily digested.f 
* Graham-flour, containing the whole of the wheat-grain, makes 
sweet and wholesome bread. Rolls made of this flour, by simply mix- 
ing the flour with water or milk, and then pouring the thin batter into 
a hot roll-pan, and baking in a hot oven, are among the best forms of 
bread that can be made. The garden vegetables generally are made 
up of starch and sugar and a large amount of water. 
f Meats are best when broiled or roasted. They should be exposed 
to a hot fire at first, so that a crust may be formed on the outside to 
preserve the inside juices. 
In making soups, the meat should be put in cold water, and brought 
very slowly to the boiling-point, so as to extract the juices. EATING, AND WHAT COMES OF 17'. 
25 
Fruits are mostly made up of starch and sugar, 
but they also contain more of the mineral matter 
needed by the system than is found in most other 
foods. The acid of fruits is also an aid to diges- 
tion. Fruits are chiefly valued, however, for their 
agreeable flavors, which gently excite the digestive 
organs ; and when taken in moderate quantities they 
are very wholesome.* 
Mixed Foods.—Our study so far has shown us 
that no one substance is a perfect food, and there- 
fore that a mixture of foods is necessary to secure 
all the needed elements. Experience has taught us 
the same lesson, and the custom is general of mix- 
ing foods in such a way that one will supply the 
needed elements which the others lack. Thus 
bread, rich in gluten, lacks starch or fat, and butter 
is added ; potatoes, mostly starch, are eaten with 
meat, gravy, or butter. 
How we Eat. 
Mastication.—The first step toward reducing 
food to a condition in which it can nourish the 
When milk produces an unpleasant effect upon the stomach, it 
should be mixed with a little lime-water. 
Fish and oysters should not be eaten unless perfectly fresh. 
* Strawberries, raspberries, blackberries, currants, cherries, peaches, 
apples, melons, and oranges are all excellent, and their moderate use, 
each in its season, will, many times, make the doctor’s visit unneces- 
sary, and save us from a course of medicine. 
The puipy substance of unripe fruits is often hard and tough, and 
the juice strong and sour. When fruits, in this condition, are eaten, 
they can not be digested, and both pulp and juice cause irritation and 
pfteii inflammation of the digestive organs. Fruits are made whole- 
some by ripening and by cooking. 26 
HOW WE LIVE. 
body is chewing, or mastication. The organs di- 
rectly used in chewing are the teeth, the tongue, 
and the cheeks. The teeth grind the food. The 
tongue and the cheeks keep the food between the 
teeth so that it may be ground. 
The Teeth.—lf we examine the mouth of a cat 
or a dog, we discover four prominent teeth that are 
long and pointed. The other teeth, both front and 
back, are shorter and smaller. These sharp teeth 
can easily pierce soft substances, and seem to be of 
just the right shape for tearing flesh. 
In the mouth of a squirrel or rabbit we find the 
prominent teeth, four in number, directly in front. 
These teeth are long; but, instead of being pointed, 
they have a sharp edge like a chisel, which fits them 
for cutting hard substances or gnawing. 
If we look into the mouth of a horse, we find the 
prominent teeth broad and flat, the exact shape for 
grinding grain, or for breaking in pieces the soft 
stalks of plants. 
In our own mouths we find teeth like those of 
the dog, the rabbit, and the horse; but they are all 
nearly alike in size. The four cutting teeth on each 
jaw in front are called incisors; the four pointed 
teeth, one on each side of each jaw, next back of 
the incisors, are called canine teeth, or cuspids; the 
eight teeth next to the cuspids are the bicuspids ; 
and the twelve back teeth, six on each jaw, are 
molars. 
The parts of the teeth that lie inside the bones 
of the jaw are the roots, and the part of each tooth 
that appears outside the gums is the crown. Usu- EATING, AND WHAT COMES OF IT. 
27 
ally, the molars of the upper jaw have three roots 
each, and those of the lower jaw have two. The 
cuspids and incisors have only one root each. 
Fig. 3.—The jaws and the teeth : 1, 2, incisors; 3, canines; 4, 5, bicus- 
pids ; 6, 7, 8, molars; a, vein ; b, artery ; c, nerve ; d, vein, artery, and 
nerve. 
If we carefully examine a tooth, we find that the 
crown has a hard, smooth outside. This is called 
the enamel. Under the enamel is a softer kind of 
bone called dentine. In the middle of the tooth, and 
extending to the end of each root, is a cavity in the 
bone, through which extend a nerve and a net-work 
of blood-vessels. 28 
HOW WE LIVE. 
Care of the Teeth.—When the enamel is broken 
the tooth decays, causing severe pain and an un- 
pleasant breath. To prevent 
these troubles, the teeth 
should receive special and 
constant care. 
Some boys try to crack 
hard nuts with their teeth, but 
crack the enamel instead, and 
so spoil their teeth. Biting 
hard substances of any kind 
has the same effect. 
A pitcher when cold may 
be easily cracked by pouring 
into it a stream of hot water. 
The sudden and irregular change of temperature 
causes the break. In like manner the enamel of the 
teeth may be cracked by abruptly changing from 
cold to hot foods, as from ice-cream to hot tea. 
When food gets lodged between the teeth and is 
permitted to remain there, a kind of gas is formed 
which destroys the enamel and causes the whole 
tooth to decay. 
How to keep the Teeth Clean.—After each 
meal, the food lodged between the teeth should be 
carefully removed by a tooth-pick of wood or quill. 
The use of a pin or a penknife is apt to injure the 
teeth or the gums. On rising in the morning, after 
each meal, and before going to bed at night, the teeth 
should be cleaned with water and a tooth-brush.* 
Fig. 4.—Section of a tooth ; 
A, enamel; B, nerve cav- 
ity ; C, C, roots. 
* The tooth-brush should be stiff enough to remove all food from 
the teeth, but not so stiff as to injure the gums. EATING, AND WHAT COMES OF IT. 
29 
A little fine salt may sometimes be used with profit. 
Powdered orris-root, used sparingly, will help to 
keep the breath sweet. 
A hard substance, known as tartar, sometimes 
collects on the inside of the teeth, next the gums, 
and, if permitted to remain, will destroy both teeth 
and gums. When it begins to collect, this tartar 
may be readily removed by scraping the teeth with 
the broad end of a quill tooth-pick. 
llozv we Swallow. 
After the food has been chewed enough, it is to 
be swallowed. Before swallowing, saliva is mixed 
with it, moistening it, and making it slippery, so 
that it will go down easily. The saliva is furnished 
by the salivary glands of the mouth, and is obtained 
from the blood. 
How Saliva Flows.—The salivary glands do not 
pour out saliva all the time, but are excited to ac- 
tion in various ways. 
The movement of the jaws will produce a flow 
of saliva. In chewing, this flow is enough to moist- 
en the food, and in talking it is usually sufficient to 
keep the mouth moist. 
Touching any part of the mouth, or the presence 
of anything in it, will cause the saliva to flow, as 
every one knows who has been under the hands of 
the dentist. 
The sight, smell, or taste of food when we are 
hungry will also “ make the mouth water.” This 
may be seen by watching a cow when she is look- 
ing on while her supper of turnips is in course of HOW WE LIVE. 
30 
preparation. The saliva is produced in such quan- 
tities as to flow out of the corners of her mouth. 
Articles of a pungent taste, like mustard, pep- 
per, horse-radish, and tobacco, make the mouth 
hot, causing a free flow of saliva. 
Amount of Saliva.—We need just enough saliva 
to moisten our food. When we do not get enough, 
we find it difficult to swallow, and then there is 
trouble in the stomach. To get this amount takes 
time. Those who eat hastily, and bolt their food 
without chewing, may look forward to a time when 
they can not eat with any comfort, and when they 
will have no strength for work, or play, or enjoy- 
ment of any kind. 
We need to eat slowly and chew our food very 
fine, so that the movement of the jaws will cause 
enough saliva to pour out. Bread and vegetable 
foods need more chewing than meats. 
All flow of saliva in excess of the amount needed 
for the moistening of the food and the mouth is 
waste. The blood from which it comes is made 
thinner and poorer, and has less of the materials 
necessary for the repairs of the body. 
How Saliva is Wasted.—If we keep our jaws 
in motion when we are not eating, a useless flow of 
saliva is produced, which is waste of material and 
weakening to the body. Chewing gum and all like 
habits are therefore hurtful. 
Tobacco.—The most fruitful cause of waste in 
saliva, however, is the use of tobacco. The pun- 
gent qualities of this narcotic produce an excessive 
flow, and, when the exciting cause is constantly kept EATING, AND WHAT COMES OF IT. 
31 
up, the amount wasted often becomes serious and 
exhaustive. 
Again, by this waste the materials of the blood 
by which saliva is furnished gradually diminish. 
The saliva itself becomes weak, inactive, and unable 
to perform its special work in the stomach; and, 
besides, other materials needed elsewhere are con- 
tinually drained off. 
One other effect of the use of tobacco needs to 
be mentioned here. It gives an unpleasant odor to 
the breath, and often causes a disagreeable habit of 
spitting; so that clean, sensitive, and refined persons 
do not like to have those who use tobacco come 
near them. 
The Esophagus. The esophagus is the tube 
through which the food passes from the mouth to 
the stomach. When the food is sufficiently chewed 
and moistened, it is pressed backward by the 
tongue, and falls into the pharynx, a portion of 
the mouth which lies immediately above the esoph- 
agus. 
On its way to the pharynx it passes over the en- 
trance of the windpipe, but is kept from falling into 
it by the epiglottis, a valve which shuts down when 
the food comes along. Sometimes the epiglottis 
does not close quickly enough, and a particle of 
food, getting into the windpipe, chokes us, and 
causes us to cough until it is thrown out. By eat- 
ing slowly we avoid this danger. 
Muscles extend around the esophagus, and when 
the food enters from the pharynx they contract, the 
upper one first, and then the next in order, thus 32 
HOW WE LIVE. 
gradually forcing the food into the stomach. The 
process of eating is now done, and that of digestion 
is ready to proceed. 
Hygiene of Mastication. 
From the foregoing study of the subject we de- 
rive the following laws in regard to mastication: 
I. Take food that will best nourish the body. 
11. Eat slowly, to give the time necessary for the 
proper action of all the organs of mastication. 
111. Chew food until enough saliva is obtained 
to moisten it. 
IV. Do not injure the teeth by biting hard sub- 
stances. 
V. Avoid exposing the teeth to sudden changes 
of temperature. 
VI. Keep the teeth clean. 
VII. Swallow slowly, so as to give the epiglottis 
time to act, and thus avoid choking. 
VIII. Be sparing in the use of highly seasoned 
foods that induce too great a flow of saliva. 
IX. Do not keep the jaws in motion by chewing 
gum and other substances not needed as food. 
X. Avoid the use of tobacco, as it wastes saliva, 
weakens the body, and makes the person using it 
disagreeable. 
Something to Find Out. 
i. What other grains besides wheat are raised 
on our farms ? 
2. What garden vegetables do we raise to eat ? 
3. What part of the corn-plant do we eat ? of the EATING, AND WHAT COMES OF IT. 
33 
potato-plant ? of the beet ? of the onion ? of aspara- 
gus? of cabbage? 
4. What substance in dough makes it stick to- 
gether ? 
5. How is wheat-bread made light? 
6. Why is it more difficult to make corn-bread 
light? In making corn-bread, what is the effect of 
mixing the white of eggs with the corn-meal ? 
7. Why is fat meat more eaten in winter than in 
summer? 
8. How is the oil necessary for food obtained in 
the frozen regions ? 
9. Why is more wholesome food made from 
Graham-flour than from fine white flour ? 
10. Why is beef as a food better than pork? 
11. Why are oysters better than clams? 
12. Why is it better to roast beef than to boil it? 
13. In boiling meats, should they be put into 
cold or hot water at first ? 
14. In what condition should oysters and fish be 
when used for food ? 
15. Of what benefit is the acid of fruits? 
16. Why are green fruits unwholesome? 
17. How may green fruits be made wholesome? 
18. What kind of food should be mixed with 
the proteids ? What with the amyloids ? 
19. In cooking, what is usually mixed with maca- 
roni ? Why ? 
20. Mention other foods that are usually eaten 
together. 
2i. What are milk-teeth, and what care do they 
need ? HOW WE LIVE. 
34 
22. When the permanent teeth show signs oi 
decay, what should we do? 
23. Why should we be sparing in the use of 
mustard and horse-radish ? 
24. When people know that the use of tobacco 
is hurtful, why do they not leave it off? 
25. What is the best way to avoid the trouble of 
leaving off the use of tobacco ? 
26. What evils follow from eating too rapidly ? CHAPTER 111. 
HOW DIGESTION GOES ON. 
To nourish the body, food taken into the stom- 
ach must be converted into blood. The process of 
preparing- food to enter the blood, called digestion, 
takes place chiefly in the stomach and intestines. 
Stomach Digestion. 
Structure.—The stomach is a sack or bag in the 
lower cavity of the body, and holds from one to two 
quarts.* It has two openings. Through the up- 
Fig. 5.—The stomach. 
* The trunk has two cavities, the chest and the abdomen. These 
cavities are separated by a thick, muscular membrane, called the dia- 36 
HOW WE LIVE. 
per opening, or cardia, the food comes in from the 
esophagus; and through the lower opening, or 
pylorus, the food, when in a proper condition, passes 
out into the intestines. 
The stomach is made up of three coats. The 
outer, or serous, coat is strong and smooth. Its 
glossy surface is moistened by the serum from the 
blood, so that, when it rubs against the walls of the 
trunk, or against any of the other organs, there is 
no friction. 
The middle coat is made up of muscles, which 
extend around the stomach in both the longest and 
shortest ways. These muscles contract and ex- 
pand, giving motion to the stomach, and churning 
its contents. 
The inner, or mucous, coat is soft, and lies in 
little ridges or folds, giving a great amount of sur- 
face. This coat secretes from the blood a fluid, 
known as the gastric juice, which flows in large 
quantities when the stomach is full. The churning 
process brings the gastric juice into contact with 
the food, and thoroughly mixes the contents of the 
stomach. 
Food Changes.—The saliva, mixed with the 
food, is one of the agencies for changing the amy- 
loids into grape-sugar—a process necessary to fit 
these substances to enter the blood. 
The gastric juice dissolves the proteids, such as 
the albumen of eggs, the gluten of grain, and the 
fibrine of meat, and makes them fit to enter the blood. 
phragm. This membrane is attached to the walls of the trunk, and 
forms the floor of the chest and the roof of the abdomen. HOW DIGESTION GOES ON. 
37 
A small portion of the food is taken up from the 
stomach by little tubes, called absorbents, and is car- 
ried at once to the blood-vessels. But by far the 
greater part is converted into a slimy, fluid mass, 
called chyme, and passes through the pylorus into 
the intestines. 
Drink.—At each meal enough drink should be 
taken with the solid food to moisten the mass in the 
stomach. If too much is taken, the gastric juice is 
so diluted and weakened that it can not properly 
perform its work. 
For the action of the mucous and muscular coats 
of the stomach, and of the absorbents, the animal 
heat must be kept up. By drinking ice-water, or 
any very cold drinks, with our meals, the heat is 
diminished, and the work of digestion goes on 
slowly, or not at all, until the heat is restored. 
Alcohol in the Stomach. When wine, beer, 
whisky, or other drink containing alcohol, is taken 
into the stomach, the first effect is to excite the 
mucous coat, and increase the flow of the gastric 
juice. If the drink is continued from day to day, 
the gastric flow increases, and is excessive. In con- 
sequence, it becomes thin and weak, and is unable 
to perform its proper work of digestion. 
But alcohol has a great power of absorbing 
water. It takes moisture out of the mucous coat 
of the stomach. By continually drinking it, the 
stomach becomes hardened, and is unable to supply 
gastric juice enough for digestion. If the drinking 
is then kept up, more or less active inflammation 
always sets in, often causing long illness, or death. 38 
HOW WE LIVE. 
Alcohol has another peculiar effect. Its action 
on the stomach leaves a sickly, sinking sensation, 
which can be relieved only by alcohol; and so 
drink induces drink, until the habit is formed from 
which no one can escape without great suffering. 
While the alcohol is busy with its work in the 
stomach, the absorbents are trying to get rid of it. 
They take it up unchanged, and pass it on into the 
blood-vessels, ready to repeat elsewhere the mis- 
chief it has begun in the stomach. 
Intestinal Digestion. 
Structure.—The intestines are tubes lying in a 
coil, through which the food passes after leaving 
the stomach. The small intestine is about one inch 
in diameter and twenty feet long. The large intes- 
tine is twice as large, and five feet in length. This 
gives to the whole canal below the stomach a length 
of about twenty-five feet. 
Like the stomach, the intestines have three coats, 
serous, muscular, and mucous. The mucous coat 
secretes from the blood and pours out in small 
quantities the intestinal juices. These mix with the 
chyme coming from the stomach, and convert into 
sugar the starchy particles which have before es- 
caped digestion. 
The muscular coat of the intestines consists 
mostly of rings, and these, beginning with the one 
nearest the stomach, contract, one after the other, 
like those of the esophagus. This action forces the 
contents downward, and finally expels the waste 
portion from the bod}^. HOW DIGESTION GOES ON. 
39 
Fig. 6.—The organs of digestion :a, duodenum, leading out of the pylorus; 
b, liver; c, esophagus ; d, pancreas ; e, stomach ;/, spleen ;g,z,j\ k, m, 
n, parts of large intestine ; A, /, small intestine. 
The Duodenum.—The upper part of the small 
intestine, about twelve finger-breadths in length, is 
called the duodenum. The chyme enters this canal 
from the stomach, and on its passage receives two 
fluids known as pancreatic juice and bile, and these 
still further prepare the food for the nurture of the 
body. 
The Pancreas.—The pancreas is an organ lying 
back of the stomach, irregular in shape and about 40 
HOW WE LIVE. 
six inches long.* It secretes pancreatic juice from 
the blood, and pours it out into the duodenum to 
mix with the chyme. The pancreatic juice acts 
upon the amyloids, proteids, and fats which have 
passed through the stomach unchanged. 
When the chyme enters the duodenum, the oily 
portion lies on the surface. The pancreatic juice 
unites with it and divides it into minute particles 
and mixes it through the whole mass of chyme, as 
the oily particles of cream are divided and mixed 
in milk. A part of the oil is converted into a sub- 
stance resembling soap. 
The Liver.—The liver is a large organ lying on 
the right side under the lower ribs. It secretes 
bile from the blood and pours it out into the duo- 
denum. The portion of the food taken up by the 
absorbents and carried to the veins passes through 
the liver, and in the liver-cells soluble amyloids are 
converted into glycogen, a sugary substance which 
readily enters the blood. 
The office that bile has to perform is not fully 
understood. That it is waste matter which the 
blood must get rid of, is shown by the fact that, 
when resorption of the bile takes place, the body 
becomes yellow with jaundice. It is pretty well un- 
derstood that the bile assists the pancreatic juice in 
reducing fats ; that it supplies alkali to neutralize 
the acid of the chyme ; and that it stimulates in 
the intestines a mucous secretion which lubricates 
them and renders the passage of waste matter easy. 
* In animals whose flesh we eat, the pancreas is called sweet-bread, 
and is considered a great delicacy for the table. HOW DIGESTION GOES ON. 
41 
Alcohol in the Liver. The alcohol expelled 
from the stomach makes its next appearance in the 
whither it is carried through the portal vein. 
Here, if continued from day to day, it also changes 
the tissue, so that the work of the liver is imper- 
fectly done or suspended altogether. If the drink 
is then kept up, inflammation often sets in, causing 
much suffering and frequently ending in death. 
From the liver the alcohol passes unchanged into 
the veins. 
Absorption.—By the action of the pancreatic 
juice, and the bile in the duodenum, the chyme is 
converted into a milky substance called chyle, and 
continues its way through the intestines. In its 
passage, the portions fit to make blood are taken 
up by the absorbents and lacteals and are carried to 
the veins. 
The mucous coat of the stomach and the intes- 
tines is covered with a net-work of minute veins, 
and into these a portion of the food is carried 
directly. These veins all empty into the portal 
vein, which terminates in the liver. After a change 
effected by the liver, through the hepatic veins, this 
material is poured into the large vein ascending 
from the lower extremities. 
The Lacteals.—All along the intestines are little 
absorbent tubes known as lacteals.* These unite 
in little groups and form larger tubes. These at 
last all terminate in a single tube, about the size 
* It is estimated that these lacteals number about seven thousand 
in each square inch of surface, and that in the entire length of the 
intestines they number from three to five millions. HOW WE LIVE. 
42 
of a goose-quill, which lies in front of the spinal 
column, and is known as the thoracic duct. 
Fig. 7.—The lacteals and their connections : a, portal vein; b, g, thoracic 
duct; c, groups of lacteals ; d, e, intestine ; _/, lacteals. 
The greater part of the chyle is absorbed by the 
lacteals. It is carried to the thoracic duct. 
Ascending through that tube, it is poured into 
a vein which lies under the left collar-bone, or clavi- 
cle, and is known as the subclavian vein. It now 
finds its way to the heart through the currents from 
the upper extremities. 
Summary of Changes.—Food is masticated in 
the mouth by the teeth, and is mixed with saliva. 
The amyloids are digested by the action of the 
saliva, the pancreatic juice, and the intestinal juices, 
and by a change effected in the liver. HOW DIGESTION GOES ON. 
43 
The proteids are reduced, or dissolved, in the 
stomach by the gastric juice. 
Acids are neutralized by the alkali of the bile. 
Oily substances are reduced in the intestines by 
the action of the bile and the pancreatic juice. 
These several changes complete digestion, and 
change food so that it readily enters the blood. 
Hygiene of Digestion. 
Like other parts of the body, the digestive or- 
gans need rest. If kept constantly in action, they 
become weary and unable to perform their proper 
work. From this fact, and from the lessons which 
have gone before, we derive the following hygienic 
laws : 
I. Take food that can be digested. 
11. The food should be so prepared as to digest 
most easily. 
111. Enough food should be taken to nourish 
the body, and no more.* 
IV. Food should be taken at regular times, with 
intervals between sufficient to give the digestive 
organs a chance to rest.f 
* The best guide to the proper kind and amount of food is a health- 
ful appetite. As there is a pleasure in eating, however, there is danger 
of eating too much, especially if the food is taken rapidly. The appe- 
tite, too, may be spoiled by various indulgences, and then it ceases to 
be a guide. In such cases the only way we can determine what is best 
for us is by the study of the nature of foods, and by experience as to 
what seems to suit our own conditions best. 
f If children must eat candy and sweetmeats, the best time for 
them is directly after a meal, as the habit of eating between meals is 
very injurious. After a long process of digestion, the tiny digestive 
organs become tired, and it is wrong to overtax them. We ourselves 44 
HOW WE LIVE. 
V. At meal-times, and until digestion in the 
stomach is nearly finished, water and other liquids 
should be taken sparingly. 
VI. Avoid the use of tobacco, as it prevents the 
changes which should be made by the saliva. 
VII. Avoid the use of alcoholic drink, because 
it prevents the changes which should be made by 
the gastric juice and by the liver. 
VIII. Avoid all substances, like unripe fruits, 
that have a tendency to create disturbances in the 
intestines. 
Something to Find Out. 
i. What would be the effect if the serous coat 
of the stomach should become rough? 
2. What would be the effect if the muscular coat 
should cease to act ? 
3. What effect has the gastric juice upon starch? 
4. When the mouth is full of food, should we 
take drink to “ wash it down ”? 
5. Why is it better to take drink toward the end 
of a meal than at the beginning? 
6. What is the effect of taking ice-cream after a 
meal ? 
7. How do vinegar and sour fruit sometimes 
improve digestion ? 
8. Why are biscuits containing a large quantity 
of soda hurtful ? 
9. Under what circumstances may it be proper 
to take a little soda into the stomach ? 
need a rest after a hard task, and are discouraged, if, when our work 
seems to be done, more is given us to do. So it is with the little 
lacteals and absorbents. It is not fair to keep them constantly at work. HOW DIGESTION GOES ON. 
45 
10. Should we take food “between meals”? 
Why? 
ii. Should we eat just before going to bed? 
Why ? 
12. What is the harm of eating when we are 
tired ? 
13. Should we engage in violent exercise just 
after a meal ? 
14. What is the best condition to be in for the 
half-hour before and after meals ? 
15. What are the best foods for invalids and per- 
sons with weak stomachs ? 
16. Why is pork eaten less in summer than in 
winter ? 
17. How can we avoid the evil effects which 
tobacco causes in the stomach ? 
18. In what way is the habit of taking alcoholic 
drinks formed ? 
19. How can we avoid the suffering caused by 
breaking off such a habit ? 
20. Why do people begin the use of strong 
drink ? 
21. Among the people you know, which are in 
the better condition, those that use strong drink, or 
those that do not ? 
22. When, after eating, we have a pain in the 
stomach, what is the probable reason for it ? 
23. Should such pain teach us anything ? If so, 
what ? CHAPTER IV. 
HOW THE BLOOD GETS PURIFIED. 
The newly made blood brought by the lacteals 
and absorbents is poured into veins, where it min- 
gles with the currents returning to the heart. This 
blood is laden with materials which the body no 
longer needs, and before it can nurture the body it 
must be purified. For this purpose, it must come 
in contact with air, to which it may give off the 
waste matter it contains, and from which it may 
receive oxygen. 
The Heart. 
On its way to the air, the venous blood first en- 
ters the heart. This organ is placed in the chest 
between and partly behind the two lungs, and 
slightly on the left side. It is about as large as 
the fist, and is shaped somewhat like a pear. It 
points downward toward the front. It is made up 
entirely of strong muscular fiber, so that it can con- 
tract with very great force.* It is surrounded by 
*lt has been found that, during twenty-four hours, the average 
healthy human heart does an amount of work equivalent to raising 
92.425 tons one foot high, or of raising one ton over 92 feet high. A HOW THE BLOOD GETS PURIFIED. 
47 
a smooth, satin-like membrane, called the pericar- 
Fig. B.—The heart and large blood-vessels : A, right ventricle; B, left ven 
tricle; C, right auricle; D, left auricle; E, aorta; F, pulmonary artery. 
The Plan of the Heart.—The heart, like many 
other parts of the body, has a double structure. 
good climber can only raise his own weight g,ooo feet in nine hours, 
or 1,000 feet an hour ; while the work done by the heart is equivalent 
to raising its own -weight (ten ounces) 13,860 feet an hour. The most 
powerful engine ever made by man, the “Bavaria” locomotive of the 
Vienna and Trieste Railway, can only raise itself through 2,700 feet in 
an hour ; that is, its energy is less than one fifth of that of the human 
heart.—(“ The Heart and its Function.”) 48 
HOW WE LIVE. 
Its right and left sides are entirely separated by 
an unbroken wall of muscle. In structure, the two 
sides are nearl}r alike, but each side has its own 
separate work to do. The right side, which re- 
ceives the blood from the veins and sends it to the 
lungs to be purified, is sometimes called the pulmo- 
nary heart; and the left side, which receives the 
blood from the lungs and sends it out to nurture 
the system, is called the systemic heart. 
Each side of the heart has two cavities, the 
smaller one being above, and the larger below. 
The upper cavities are called auricles, and the lower 
ones ventricles. As the blood flows from the veins 
into the auricles gently, the walls of the upper part 
of the heart are not so thick and strong as if they 
were intended to sustain a heavy strain. 
From the ventricles the blood must be forced 
or driven, through the blood-vessels, and, in conse- 
quence, the muscular walls of the ventricles are 
thick and strong. 
Between the auricles and ventricles are valves 
opening downward, which admit blood freely from 
above, but which close and prevent its return. The 
blood-vessel leading from the right ventricle to the 
lungs is called the pulmonary artery. 
Pulmonary Action.—The currents from the veins, 
one from the upper extremities and one from the 
lower,* unite and empty into the right auricle of 
the heart. The walls of the auricle contract, and 
force the blood through the valve into the right 
* The large vein from above is called the superior vena cava ; and 
that from below, the inferior vena cava. HOW THE BLOOD GETS PURIFIED. 
49 
ventricle. The powerful muscular walls of the ven- 
tricle then contract, the valve shuts, and the blood 
is driven through the pulmonary artery to the 
lungs, where it comes in contact with the air. 
The lungs are in two divisions, occupying the 
right and left sides of the upper part of the chest. 
The Lungs. 
Fig. 9.—The cavity of the chest, showing the positions of the heart and the 
lungs : A, left lung ; B, heart; D, pulmonary artery ; E, trachea, or 
windpipe. 
The right side has three distinct parts called lobes, 
the left has two. 
Structure of the Lungs.—The lungs are made 
3 50 
HOW WE LIVE. 
up of soft, elastic tissue arranged in the form of 
minute cells. These cells are connected with small 
Fig. 10.—Air-passages in the human lungs : a, larynx; b, trachea; c. d, 
bronchi; e, bronchial tubes ; f clusters of air-cells. 
passages, which open into larger ones, uniting in a 
single pipe. All these passages, small and great, 
are called bronchial tubes, or bronchi; and the pipe 
into which these open is the windpipe, or trachea. 
Lying next above the trachea is the larynx,* which 
opens directly into the throat, and through the 
nasal passages and the mouth into the air. 
The pulmonary artery comes out of the right 
ventricle of the heart as a single tube ; but it finally 
divides into five branches, one extending to each of 
the five lobes of the lungs. 
Entering the lungs, these blood-vessels divide 
into minute passages, which extend to every part 
* The larynx makes a lump in the neck which we can feel, and 
which is called “ Adam’s apple.” HOW THE BLOOD GETS PURIFIED. 
51 
of the lungs, and surround every air-cell. Indeed, 
the lungs may be considered as made up of air- 
passages and blood-vessels, with just enough tissue 
to form the necessary cells and tubes.* The lungs 
are surrounded by a smooth membrane called the 
pleura. 
How the Chest Varies.—The capacity of the 
chest varies with the breath, increasing as the breath 
comes in, and diminishing as it goes out. This 
change is effected by the movement of the ribs and 
the diaphragm. In the process of breathing, the 
respiratory muscles contract, and move the ribs out- 
ward and upward. At the same time, by the con- 
traction of the muscles of the diaphragm, its arch is 
drawn down, and the cavity of the chest is made 
both broader and deeper. 
When these muscles relax, the ribs droop down- 
ward, the diaphragm returns to its arched position, 
and the chest is narrowed and shortened. 
Forces in Breathing.—Breathing is brought 
about by two forces—the pressure of the air, and 
the elastic force of the lung-tissue. When the ribs 
are elevated and the diaphragm is depressed, there 
is a tendency to produce a vacuum between the 
lungs and the walls of the chest. The air, pressing 
fifteen pounds to the square inch, forces its.way into 
the air-passages of the lungs, and expands the lung- 
tissue so that it fills the enlarged space within the 
* If two small trees with bushy tops were placed together in such a 
way that the branches and twigs of one were closely interlaced with 
the branches and twigs of the other, they would show how the divis- 
ions of the pulmonary artery and those of the air-passages are brought 
together in the lungs. 52 
HOW WE LIVE. 
chest. This act, of breathing the air in, is called 
inspiration. 
When the ribs and the diaphragm return to their 
passive condition, as the tendency to a vacuum no 
longer exists, the pressure of the air ceases, and the 
elastic tissue contracts, forcing the air out. This 
act of breathing out is called expiration, and the 
whole act of breathing is called respiration. 
Action in the Lungs.—At every inspiration the 
air passes through the nose * or the mouth into the 
bronchials and finds its way into every little air-cell. 
The walls of these cells, separating them from the 
blood-vessels, are so thin that air and gas readily 
pass through. In this way the impure matter of 
the blood finds its way into the air-cells, and the 
oxygen of the air enters the blood-vessels. 
Results of Breathing.—The air, which comes 
into the lungs pure, goes out laden with carbonic- 
acid gasf and other impurities. It is so foul that 
it is unfit to be breathed again. 
The blood, which comes into the lungs laden 
with impurities, gives off waste matter, and re- 
* The outer nasal passages are supplied with fine hairs, so that the 
air on its way to the lungs is filtered, and no dust is allowed to pass. 
The nose has also the sense of smell, and whenever it detects foul 
odors the air is unfit to breathe. The nose thus becomes a sentinel at 
the gate of*the lungs. For these reasons we should always breathe 
through the nose instead of through the mouth. 
f Carbonic-acid gas is one of the products of worn-out animal tissue. 
It is also produced by burning wood and coal, and in other ways. Air 
that contains much of it is unfit to breathe. It is, however, one of the 
principal supporters of vegetable life. Vegetation takes up carbonic 
acid and pours out the oxygen necessary to animals. The two great 
divisions of living things thus continually work for one another. HOW THE BLOOD GETS PURIFIED. 
53 
ceives life-giving oxygen. Its color is changed 
from a dark, dull red to a bright scarlet, and it is 
filled with the strength and health necessary to 
nurture the body. 
Return of the Blood.—The blood, thus purified 
and strengthened, flows from the small passages 
of the pulmonary artery into similar small passages 
of the pulmonary veins. These small vessels open into 
larger ones, and finally they all unite, forming four 
principal tubes, two upon the right side and two upon 
the left, and pour the blood into the left auricle of 
the heart. The blood is now purified and ready to 
be sent out to nourish all the parts of the body. 
Alcohol in the Lungs.—The alcohol which en- 
tered the veins from the liver makes its appearance 
in the lungs. As it does not become a part of the 
blood, or furnish it with any needed element, an 
effort is here made to get rid of it. The foul breath 
of those who drink whisky or beer shows how ear- 
nest this effort is. 
But the lungs have enough to do to relieve the 
blood of its waste matter. To get rid of the alcohol 
requires additional work, and this work, when ex- 
cessive and continuous, wearies and weakens. After 
a long effort in trying to expel alcohol, the lungs 
become so feeble that they readily contract diseases 
such as pneumonia and consumption, and these dis- 
eases are much more rapid and violent when they 
take hold of weakened tissue. 
If the amount of alcohol is large, the lungs can 
not get rid of the whole of it, and a portion enters 
the pulmonary veins and mingles with the currents 54 
HOW WE LIVE. 
that circulate through the body. Here, as before, 
the alcohol is in the blood but not a part of it, and 
efforts are made to expel it wherever it appears. 
Tobacco in the Lungs.—ln smoking, the fumes 
of tobacco are frequently drawn into the lungs. 
This is especially the case in smoking cigarettes. 
The effect of the tobacco upon the lung-tissue is to 
retard its action, so that all the changes effected by 
breathing are more slowly performed. In this way 
the blood goes on in its course without being suffi- 
ciently purified, and is therefore unable to properly 
nourish the body. The first result is a feeling of 
languor and repose, and this, if repeated, often be- 
comes torpor and stupidity. 
Tobacco affects children most unfavorably be- 
fore they have attained their full growth. The ac- 
tion of the organs necessary for growth and bodily 
activity is retarded, the body becomes feeble, and 
is often stunted. The mind is rendered as weak as 
the body, and many times it loses all power of effect- 
ive study. 
The Need of Pure Air.—We have already seen 
that the air once breathed is no longer pure. It is 
just as unfit for breathing again as muddy water is 
for drinking or decayed food for eating. But air 
is rendered impure in many other ways. From 
stagnant water and from decaying animal and vege- 
table substances, gases arise which make the air un- 
fit for breathing. Whenever foul air is breathed, the 
blood is not fully purified, and the body is not prop- 
erly nourished. Some of the most fatal diseases re 
suit from breathing air laden with foulness. HOW THE BLOOD GETS PURIFIED. 
55 
Hygiene of Respiration. 
As air is a necessity of life, some of the rules that 
should guide us in regard to air become obvious: 
I. When the nose detects an unpleasant odor, 
the air is foul, and we should avoid breathing it, if 
possible. 
11. We should not breathe air that is made foul 
by our own breath, or by that of other persons. 
111. We should not stay long in a crowded room, 
unless it is well ventilated. 
IV. We ought not to sleep in small, ill-ventilated 
bedrooms. 
V. Impurity of air in a room can be detected 
only when coming in from fresh air; hence extra 
care should be taken to thoroughly ventilate all 
occupied rooms every day. 
VI. We ought to keep away from the vicinity 
of stagnant water. 
VII. We should never permit decaying animal 
or vegetable matter to remain near our houses. 
VIII. We should carefully avoid breathing the 
gas from sewers, sinks, and cess-pools. 
IX. We should avoid alcohol, tobacco, and other 
articles that give extra foulness to the breath. 
X. No article of dress should be worn so tight 
as to prevent the expansion of the chest in respira- 
tion. 
XL The weight of the clothes should hang from 
the shoulders, or be so distributed as not to be felt 
as a band about the ribs. 
XII. We should never sit or stand in such a way 56 
HOW WE LIVE. 
as to cramp the chest, and prevent full and free res- 
piration. 
Something to Find Out. 
2. Why is the pericardium, which incloses the 
heart, smooth on the outside ? 
1. What parts of the body lie next to the heart? 
3. What besides the smooth surface of this mem- 
brane prevents friction ? 
4. What kind of membrane forms the pleura, 
and what is its use ? 
5. What is the name of the disease to which the 
pleura is subject? 
6. How may the lungs of a sheep or a calf, which 
we get from a butcher, be filled with air ? 
7. When these lungs are full, how is the air 
driven out? 
8. About how much force is required to inflate 
our lungs ? 
9. Why is it more difficult to breathe on the top 
of a high mountain than at the bottom ? 
10. Why is it best to have a house “somewhat 
back from a village street ” ? 
11. Why is it more healthful to travel after a 
rain than before ? 
12. What organ serves the lungs by giving warn- 
ing of the presence of foul substances ? 
13. What should we do when we get a strong 
smell of carrion ? 
14. Why should we not take a pan of live coals 
into the bedroom which we occupy ? 
15. What shall we do when we detect the pres- 
ence of carbonic-acid gas in our rooms ? HOW THE BLOOD GETS PURIFIED. 
57 
16. In what way does foul air affect the pupils 
of a school ? 
17. How should the cellar of a house be kept? 
18. What kind of sink in a kitchen is harmful? 
19. What should be done with apple and potato 
parings, and the waste part of vegetables ? 
21. Why should we particularly avoid taking 
the breath of persons who are ill ? 
20. What is to be done with tainted meat ? 
22. Why should those who drink whisky and 
beer keep distant from other persons ? 
23. Why does tobacco affect children worse than 
it does grown people ? 
24. In what way can we avoid the weakening 
effect of alcohol on the lungs ? 
25. What is the best way to avoid the stupefying 
effect of tobacco in the lungs ? 
26. In building a school-house or a dwelling- 
house, why should we place it at a distance from a 
swamp ? 
27. Why will a person coming into a room from 
the out-door air detect impure air in a room, while 
the inmates are unconscious of the impurity ? 
28, In building halls, churches, and places of 
public resort, what matter needs special attention ? 
29. When the people at church or while attend- 
ing a lecture become sleepy, what is probably the 
matter ? 
30. As the cost of ventilating a single school- 
room does not exceed twenty dollars, what excuse 
nas the district for not providing means of ventila- 
tion ? CHAPTER V. 
HOW THE BLOOD NURTURES THE BODY. 
Waste and Repair.—Every time we take a step 
or raise an arm, portions of the muscles that move 
are used up. By every motion some part of the 
body is destroyed. Each action of the stomach, 
each heave of the breath, each beat of the heart, 
consumes tissue; and, indeed, it may be said that 
every part of the body is all the time wearing out. 
But, during life, nurture also is always going 
on. Sharp little eyes are keeping watch over every 
part of the body, and nimble little fingers are busy 
in repairing and restoring. No sooner is one par- 
ticle removed, than another takes its place. On 
one side of each tiny cell the invisible sexton is 
hurrying away matter which is dead; on the other, 
the unseen builder is filling the vacant space with 
matter which is living. 
From birth to death these changes are going 
on. The agent that brings them about is the blood. 
The way in which the blood sets about its work is 
by circulation. The chief cause of circulation is 
the action of the heart. 
The Arteries.—The channels leading out from 
the heart are called arteries. They are made of a HOW THE BLOOD NURTURES THE BODY. 
59 
stiff, elastic material, so that they retain their shape 
when pressed upon, and regain it when stretched 
or bent. Like the stomach, they have three coats. 
The great artery leading out of the left ventricle 
of the heart is the aorta. This main tube divides, 
sending large branches upward to the head and 
upper extremities, and downward to the lower ex- 
tremities. These branches divide again and again, 
until they terminate in minute tubes distributed to 
every part of the body. 
The Capillaries.—From the extremities of the 
small arteries a net-work of fine, hair-like tubes, 
called capillaries, extends through nearly all the 
tissues of the body. These tubes lie so close to- 
gether that we can scarcely thrust the point ol a 
fine needle into any part of the body without pierc- 
ing some of them. 
The Veins.—The capillaries, at the extremity 
opposite to the arteries, open into minute veins. 
These veins come together and form larger ones, 
until they all unite in two principal channels—the 
superior vena cava from the upper exti*emities, and 
the inferior vena cava from the lower. These two 
receive the blood and pour it into the right auricle 
of the heart. The walls of the veins are not stiff, 
like those of the arteries, but readily yield to 
pressure. 
Action in the Heart.—As we have already seen, 
the purified blood from the pulmonary veins pours 
itself into the left auricle of the heart. The muscu- 
lar walls of the auricle contract, and force the blood 
into the left ventricle. Then the walls of the ven- HOW WE LIVE. 
tricle contract, the valve opening from the auricle 
shuts, and the blood is driven through the arteries 
into every part of the body.* To drive the blood 
so far and so rapidly requires a great amount of 
force, and therefore the walls of the left ventricle 
of the heart are very thick and strong. 
Action in the Arteries.—The arteries are usu- 
ally placed deep in the flesh, to be out of the way 
of harm. The blood is forced into them by jets at 
each heart-beat. Their elastic walls yield to the 
rush, but contract again, helping the blood along 
its course.f In this way the minute vessels are 
filled, and the beating or pulsation which began at 
the heart is carried on to the extremities, so that 
every part of the body is quivering with motion 
and life. 
Action in the Capillaries.—From the extremi- 
ties of the small arteries the blood enters the capil- 
laries. In each the stream is very minute and flows 
at an even rate. Here nutrition takes place. Oxy- 
gen from the blood unites with particles of tissue, 
* The average number of heart-beats in a minute is about seventy. 
The number is greater in children than in adults, and greater in women 
than in men. With the body in a standing position,-the heart has not 
only to force the blood to all parts of the body, but has to lift it from 
the chest to the head, and from the feet to the chest. When we lie 
down, the heart is relieved from this necessity of lifting, and its ac- 
tion is diminished. The amount of blood which the heart moves is 
estimated at eighteen pounds per minute. 
•j- At the wrist, and at some other parts of the body where the ar- 
teries come near the surface, we can feel the pulse. Each beat of the 
pulse is the yielding of the artery to a beat of the heart. One of the 
surest means by which the physician finds out the condition of the body 
is the beating of the pulse. HOW THE BLOOD NURTURES THE BODY. 
61 
and burns them, causing both the heat and the mo- 
tion of the body. The particles thus destroyed by 
use are taken up and carried away, and new par- 
ticles full of life and strength are deposited in their 
place. In this way tissue is repaired, vigor is re- 
stored, health is kept up, and life is continued. 
Action in the Veins.—The blood as it enters 
the veins from the capillaries is changed. The 
limpid current has become thick and turbid ; the 
bright scarlet has deepened to a dark, dull red. 
The jets have ceased, and the current flows on 
smoothly and evenly. All along the courses of the 
veins, valves open toward the heart, so as to allow 
the blood to freely flow in that direction ; but they 
shut, so as to prevent its return. In action, the 
muscles press upon the veins and hasten the flow ; 
so that work, play, and exercise of every kind, help 
the blood along its course.* From the veins the 
blood flows, as we have seen, into the right auricle 
of the heart. 
Alcohol in the Blood.—The alcohol which the 
lungs can not expel returns to the heart and enters 
the general circulation. Although never becoming 
a part of the blood, its power for mischief continues. 
It causes blood-particles to shrink, probably by ab- 
* Persons who are obliged to stand much of the time are often 
troubled with what are called varicose veins. The forces that cause 
circulation are not sufficient to raise the blood from the feet to the 
heart through so many hours without rest; and in consequence the 
blood presses back on the veins until they yield to the pressure and 
gradually enlarge. The valves soon become useless, increasing the 
pressure and the enlargement. The only remedy is a change to some 
employment that will require less standing. 62 
HOW WE LIVE. 
sorbing moisture from them, so that they can not 
take up the proper amount of oxygen in the lungs. 
As a result, incomplete combustion takes place in 
the capillaries ; the veins receive half-burned parti- 
cles which the lungs can not expel; dead matter en- 
ters the arteries, vitiating the blood ; and the repair 
of waste is interrupted or imperfectly performed. 
The continual use of alcohol also often changes 
the muscular tissue of the walls of the heart into a 
fatty substance which can not bear the strain put 
upon it. In consequence, when a person gets in 
this condition he has no strength to move about, 
and often he can not stand. Sometimes the weak- 
ened walls burst, causing instant death. 
The constant presence of alcohol is also felt in 
the arteries. It causes an enlargement of the minute 
vessels, so that blood accumulates in them and inter- 
rupts the usual flow through the body. This is 
shown by the flushed face of a person who has been 
drinking. The effect of a single drink will soon pass 
away, and the arteries will regain their form ; but 
the red faces and redder noses of those who drink 
to excess show that these vessels may become per- 
manently enlarged. 
Hygiene of the Circulation. 
I. We should breathe pure air, and frequently 
take long-, deep breaths, so that the blood may be 
properly purified. 
11. We should not take into our stomachs any- 
thing that enters the blood but does not become a 
part of it. HOW THE BLOOD NURTURES THE BODY. 
63 
111. We should avoid the use of anything that 
disturbs the regular action of the heart and prevents 
the full nutrition of the body. 
IV. We should relieve the heart of much hard 
labor by taking regular and sufficient exercise. 
V. Should the heart show signs of weakness, we 
may favor its recovery by taking a reclining posi- 
tion. 
VI. We may also greatly assist circulation, and 
so relieve the heart, by daily rubbing the skin 
briskly with a brush or a coarse towel. 
VII. We should avoid the use of all substances 
that tend to enlarge small blood-vessels and give a 
permanent redness to the face. 
Something to Find Out. 
1. When, and by whom, was the circulation of 
the blood first discovered ? 
2. How much blood does the heart move in an 
hour ? in a day ? in a year ? 
3, If half the blood flows to the upper extremi- 
ties, an average of one foot above the heart, one 
pound of blood is raised how many feet in a min- 
ute ? how many in an hour ? 
4. How can we tell the difference between a vein 
and an artery that is near the surface ? 
5. Which way does the blood flow in the arter- 
ies ? in the veins ? 
6. When a blood-vessel is ruptured, how can we 
tell whether it is an artery or a vein ? 
7. If a vein is wounded in one of our limbs, how 
may the flow of blood be stopped ? 64 
HOW WE LIVE. 
8. On which side of the wound should the band 
be placed ? 
9. In case an artery is wounded, where should 
the band be placed ? Why ? 
10. When an accident occurs, and blood is flow- 
ing freely, what should we use as a band ? 
11. How can we draw the band tight enough to 
stop the flow of blood ? 
12. If the wound is on the head, neck, or trunk, 
what is to be done ? 
13. In case of serious wounds, what next is to be 
done after stopping the flow of blood ? 
14. When blood flows from the veins, what 
change in it takes place from exposure to the air ? 
15. How does this change affect the flow of the 
blood from small veins ? 
16. What forces besides the heart-beat assist in 
the circulation of the blood ? 
17. How does a reclining position relieve the 
heart ? 
18. In its effect upon circulation, how does the 
work of a farmer compare with that of a clergy- 
man ? 
19, How does the work of a cook compare with 
that of a sewing-girl in its effect upon the heart ? 
20. How may a person whose business confines 
him to a sitting posture relieve his heart of extra 
work, and so preserve his health ? 
21. Why should clerks in stores be permitted to 
sit a portion of the time ? 
22. In regard to circulation, to what particular 
danger are conductors on railroads exposed ? HOW THE BLOOD NURTURES THE BODY. 
65 
23. When attending school, what should we do 
to promote circulation ? 
24. Why is exercise out-of-doors usually better 
for the health than exercise in the school-room ? 
25. If a person is found exhausted, with his skin 
pale and cold, what is the trouble as regards circu- 
lation ? What is the remedy ? 
26. When a sudden chill drives the blood away 
from the surface, what should be done at once ? 
27. What are some of the common causes of 
chills ? 
28. What are some of the ways of stopping per- 
sistent bleeding at the nose ? 
29. When persons faint, in what position should 
they be placed, and what remedies should be ap- 
plied ? 
30. In what way can we avoid the red blotches 
on the skin which come from the use of “ strong 
drink ” ? CHAPTER VI. 
HOW THE BODY IS ABLE TO MOVE. 
Motion necessary to Life.—ln finding out how 
the body is nourished, we have seen that motions 
are required. To get and prepare the food which 
the body needs, we must make many movements 
of the arms, the legs, and various other parts of the 
body. To chew the food, we must move the jaws. 
The rings of the esophagus must successively con- 
tract, in order to force the food into the stomach. 
The stomach must keep up a vigorous action, in 
order to churn its contents into chyme. The heart 
must keep on contracting and expanding, in order 
to send the blood through the arteries to the va- 
rious parts of the system. The movements by 
which breathing is carried on must never cease. 
The head must move in various directions, in order 
to pay attention to what is going on about it. In 
fact, the parts of the body are always in motion. 
Besides the motions which we notice, there are al- 
ways going on within us many movements which 
we do not notice, but which are necessary to our 
existence ; and, when we can no longer discover 
any motion in the body, we know that it is dead. HOW THE BODY IS ABLE TO MOVE. 
The Muscles. 
In order to produce all these motions, it is plain 
that the body must be provided with proper appa- 
ratus ; and, on examination, we find that the greater 
part of what we call flesh is collected into bands, 
and so fastened to the various parts of the body as 
to pull them in the different directions required. 
These fleshy bands are called muscles. They are 
about five hundred in number, and have many dif- 
ferent sizes, shapes, and lengths, according to the 
work they have to do. Besides their use in pro- 
ducing bodily motion, in which they may be com- 
pared to the ropes of a ship, they are so arranged 
as to give beauty and symmetry to the form.* 
General Structure of Muscles,—The steak which 
we eat for breakfast, and all the other lean meat 
which we have, is muscle. When we examine such 
a piece of meat especially after it has been boiled, 
we find that it is made up of fibers, all extending 
in the same direction, and bound together by a thin 
membrane called connective tissue. When the fibers 
are placed under a microscope, they are seen to be 
composed of a collection of still finer strands, or 
threads, called fibrils.f Some of the muscles are 
round, some are flat; some are not more than a 
sixth of an inch long, while others are more than 
* The plumpness of the body is still further increased by the layers 
of fat with which the muscles are surrounded. 
f In the muscles which are controlled by the will, the fibers are 
crossed by regular lines, or stripes. There are about ten thousand of 
these lines to an inch, and the muscles in which they appear are said 
to be striped, or striated. 68 
HOW WE LIVE. 
two feet in length. Most of them have a large 
body, or swell, in the middle, and gradually grow 
smaller toward the ends; but a few 
are small in the middle and large at 
the ends. 
Tendons.—Some of the muscles 
are joined directly to the bones upon 
which they act; but most of them be- 
come smaller and tougher toward the 
ends, and at last terminate in strong, 
bluish-white cords, called tendons. 
The tendons are directly attached to 
the bones. They have no power of 
contraction. Wherever the tendons 
or muscles have a tendency to pull 
away from their positions, as at the 
wrist and the ankle, they are bound 
in place by stout bands, called liga- 
ments. 
Hollow Muscles. Some of the 
muscles are not intended to connect 
one part with another, but form ves- 
sels to contain fluids. Such are the 
heart and the middle or muscular coat 
of the stomach, which have already 
been described.* 
How the Muscles Act.—All the 
muscles have power to contract or become shorter; 
and, when the exciting cause is removed, to re- 
Fig. ii.—The mus- 
cles and tendons 
of the lower arm, 
showing also the 
ligament encir- 
cling the wrist. 
* The muscular fibers of the blood-vessels, of the lymphatic vessels, 
of the alimentary canal, of the ducts of the glands, and of the iris of 
the eye, are so arranged as to form hollow muscles. HOW THE BODY IS ABLE TO MOVE. 
69 
turn to their ordinary forms. Those whose con- 
traction is under the control of the will are called 
voluntary muscles. Such are those by which the 
motions of the limbs are produced. Those which 
contract without any conscious action of the mind, 
as the heart and the stomach, are called involun- 
tary muscles. Some, like those which enable us 
to breathe, usually act of their own accord, but 
may to a certain extent be influenced by the will. 
Many of the muscles are arranged in pairs, one 
causing motion in a certain direction, and the 
other causing mo- 
tion in the oppo- 
site direction. 
The muscles 
that bend a joint 
to move any part 
are called flexors ; 
those that extend 
the parts again are 
called extensors. 
For example, 
when we bend the 
arm at the elbow, the large muscle in the front of 
the upper part of the arm contracts; and when 
we straighten the arm again, the muscle on the 
opposite side of the arm contracts. When there 
is a great variety of motions in a single joint, or in 
any organ, each distinct movement requires a sepa- 
rate muscle. The swing of the arm at the shoulder, 
the roll of the eye, the twisting of the wrist and of 
the ankle, are examples of this arrangement. The 
Fig. 12.—The left arm, showing the muscles in 
action. HOW WE LIVE. 
contraction of muscles attached to bones gives 
motion to the limbs, the trunk, and the head. The 
action of the hollow muscles gives the motions 
necessary for the 
functions of the in- 
ternal organs and 
for the circulation 
of the blood. 
How the Mus- 
cles gain Strength. 
—We have al- 
ready seen how 
the blood carries 
off the worn-out 
tissues of the 
body, and leaves 
in their place new 
material to repair 
the waste. The 
muscles are thus 
nourished by the food in the same manner as the 
other parts of the body. But Nature has also 
provided that those parts of the body which work 
the hardest shall have the most help and the most 
abundant nourishment. So, whenever a muscle is 
used a great deal, the blood carries to it an unusual 
amount of material to make and to keep it strong. 
It therefore happens that those muscles which are 
used most become largest and strongest.* 
Fig. 13.—The muscles of the legs, as in the act 
of walking. 
* The arm of a blacksmith is used so much and so vigorously that 
its muscles become, not only much larger than those of an ordinary 
person, but also much harder. The same is true of those who practice HOW THE BODY IS ABLE TO MOVE. 
71 
The Muscles need Rest.—So long as the mus- 
cles are in motion they are wearing out. To give 
time and opportunity for the repairs which are 
needed and which Nature desires to make, the mo- 
tion of the muscles must cease from time to time. 
After we have used any muscle a proper length 
of time, it becomes tired. This is Nature’s signal 
that it has done enough, and needs to be repaired. 
When a muscle is thus weakened and Nature has 
given the signal for rest, it is just as unwise to use 
it as it is to use a bridge which has been pro- 
nounced unsafe, or a rope with broken strands. Its 
use may perhaps continue for a time without seri- 
ous consequences, but it may result in permanent 
injury of the weakened part, and possibly the death 
of the offender. 
“ Exercise for Health, not for Strength.”—As 
there are in the world enough useful things to do, 
it is best to fit ourselves to do them, instead of fit- 
ting ourselves to perform useless feats of strength. 
It is the duty of every person to be as healthy as 
possible, and to so train the body that it can carry 
out the directions of the mind. Therefore, any 
kind or amount of exercise that will keep the whole 
body fresh and vigorous is desirable ; but any kind 
or amount of training that is designed to develop 
one part of the body at the expense of the rest, sole- 
ly for the purpose of display, should be discouraged. 
The amount of vitality at our disposal, and our ca- 
pacity for work, may probably be increased by judi- 
rowing, or who engage in any business requiring unusual muscular 
effort. 72 
HOW WE LIVE. 
cious exercise ; but there seems to be a limit to this 
increase. If we perform exhaustive bodily labor, 
the mind can not have so large a share of our vital- 
ity as would otherwise be the case. On the other 
hand, long and vigorous action of the mind exhausts 
so much of our vital power that the body can not 
be so active. 
This inclination of Nature to give the most help 
to the part that is working hardest or has the most 
to do, is the reason why we should not try to do 
any bodily or mental work immediately after a 
hearty meal, as the vital powers are then needed in 
the processes of digestion. For the same reason we 
should not eat more than we need ; for, if we do, so 
much vitality will be spent in digestion that we can 
not do the bodily or mental work of which we would 
otherwise be capable. 
I. We should eat plenty of wholesome food, in 
order that the muscles may grow. 
Hygiene of the Muscles. 
11. We should exercise all the muscles of the 
body, so that they may become strong and healthy. 
111. We should exercise all the muscles frequent- 
ly, to quicken the flow of blood in the veins, so as 
to take off some of the strain from the heart. 
IV. We should not exercise to such an extent 
that all the vital forces of the body are used up in 
muscular action. 
V. Any kind of exercise may become more in- 
jurious than useful, if it is allowed to overstep the 
bounds of moderation. HOW THE BODY IS ABLE TO MOVE. 
73 
VI. After each period of activity, the muscles 
need rest—daily rest after daily toil, and a long 
period of rest after the exhaustive strain of long- 
continued work. 
VII. We should carefully avoid all habits of 
Fig. 14.—Improper and proper positions in sitting. 
posture, movement, or dress that will interfere with 
the free development and action of all the mus- 
cles. 
VIII. In sitting, we should always keep the 
body as nearly erect as we can without special in- 
convenience.* 
IX. All the movements of the body should be 
* We can accustom ourselves to sitting erect by always being care- 
ful to sit well back on a chair, and not upon its edge, as the latter 
position distorts the spine and produces round shoulders. 74 
HOW WE LIVE. 
as graceful as possible, in order that they may be 
agreeable to others. 
X. Calisthenics and gymnastics are well adapted 
to give grace to the movements of the body, and 
also furnish excellent exercise for young persons. 
They should, therefore, be generally used in schools. 
XL With all their other exercise, children need 
Fig. 15.—Proper and improper positions in standing : 1, a vertical 
line ; 2, the spinal column. 
plenty of active play to keep their muscles in a 
healthful condition. 
XII. All kinds of athletic sports and manly ex- HOW THE BODY IS ABLE TO MOVE. 
ercises that are not actually dangerous should form 
a part of every boy’s education. 
XIII. Lawn-tennis, croquet, horseback-riding, 
or similar exercises, should form a part of the life 
of .every girl who is not otherwise provided with 
active physical employment. 
XIV. When work distorts the body by giving 
excessive exercise to the muscles that throw the 
shoulders forward, we should remedy the evil by 
purposely exercising the muscles that draw the 
shoulders back. 
XV. We should avoid the habitual use of beer, 
because it has a tendency to turn healthy muscle 
into a kind of spongy fat. 
XVI. When in health, we should avoid the use 
of all stimulants and narcotics, as they tend directly 
to weaken the muscles and to diminish muscular 
action. 
Something to Find Out. 
1. Why are the muscles of the right arm usually 
larger than those of the left ? 
2. Why are so many men, who work hard, round- 
shouldered ? 
3. In what way can the tendency to become 
round-shouldered be prevented ? 
4. What good comes from the practice of the 
game of base-ball ? What caution needs to be ob- 
served ? 
5. What is the effect of a tight band around a 
muscle ? 
6. When the fist is clinched, where do the mus- 
cles contract and become rigid ? 76 
HOW WE LIVE. 
7. Does the expansion as well as the contraction 
of a muscle upon one of the limbs produce motion ? 
8. Why is better exercise obtained by rowing 
than by walking ? 
9, Why is it wrong to keep children still for a 
long period at a time ? 
10. When children are restless in school, what 
are some of the probable causes ? 
11. What are some of the advantages to be 
gained by “ going a-fishing ” ? 
12. What is the best time for muscular rest ? 
13. Will it tire a horse more to travel on a level 
road, or on a moderately hilly one ? 
14. Why can not the arm hold out a weight for 
a long time ? 
15. Why should we not engage in active muscu- 
lar exercise just before eating ? 
16. After a period of hard study, what kind of 
exercise should be taken ? 
17. In running, or other violent exercise, what 
peculiar symptom tells us when to stop ? 
18. What is the consequence, if we do not obey 
the command ? 
19. What is the best employment for the half- 
hour before going to bed ? 
20. When a boy or a girl is not really ill, what 
do stooped shoulders and a shuffling gait indicate ? 
21. Why does going half a mile on an errand 
sometimes tire a boy more than walking five miles 
to see a circus ? 
22. If a person is free to choose his work, what 
principle should guide his choice ? CHAPTER VII. 
HOW THE BODY IS ABLE TO STAND. 
The Need of a Bodily Frame.—lf the body were 
made up entirely of soft materials like the muscles, 
it might be capable of motion in its different parts 
and some movement as a whole. But it would not 
be able to stand erect, or to retain any permanent 
shape. Its beautiful proportions, its graceful mo- 
tions, and its dignified bearing would all be impos- 
sible ; and a human being would be nothing more 
than a mass of flesh physically inferior to almost 
every other animal in existence. That it may be 
able to stand erect and keep its proper form, the 
body needs a strong and solid frame-work. This is 
furnished by the bones. 
Uses of the Bones.—The bones have three dis- 
tinct uses. They give shape to the body, and keep 
the various parts and organs in position. They pro- 
tect organs which would otherwise be exposed to 
injury. They afford a solid place for the attach- 
ment of muscles by means of which motion may be 
given to the various parts of the body. 
The Bones. HOW WE LIVE. 
Forms of Bones.—ln order to meet these re- 
quirements, the bones have many different sizes and 
shapes, and are arranged in the various ways best 
suited to the purposes for which they are designed. 
Those whose chief use is to protect are made strong 
and thick, and of such shape as to offer most resist- 
ance with the least material. Where several bones 
unite to protect any organ, they are placed around 
it in such a manner as will defend it most effectually. 
Those whose chief use is to furnish support to the 
body, or a base of attachment for other portions, are 
very thick and solid, and of such shape as will best 
adapt them for staying in place. Those designed 
to strengthen columns, or to produce motion, are 
long and straight. Others, which have more than 
one of these functions to perform, are so ingenious- 
ly constructed that they combine two or more of 
these features. 
Structure of the Bones.—The long bones, which 
form the frame-Avork of the limbs, consist of a slen- 
der shaft of hard, compact material, and have en- 
larged extremities composed of a soft, spongy ma- 
terial.* The shaft is hollow in the middle, and 
contains marrow. This is composed chiefly of blood- 
vessels and fat, and supplies the bone Avith nourish- 
ment. The other bones are spongy inside, and hard 
and fine in texture on the outside.f The bones are 
* The increased size and the spongy character of the extremities 
furnish better attachments for the tendons, and the increase in size 
makes up for the decrease in hardness. 
f The bones are full of fine tubes from to 5-00F0 °f an inch in 
diameter. Through these the blood passes to carry on the work of 
repair, as in the other portions of the body. HOW THE BODY IS ABLE TO STAND. 
79 
covered with a tough, fibrous membrane, except at 
the joints, where they are covered with cartilage. 
This fibrous membrane is called 
the periosteum, and when it is 
removed the bone dies. 
Materials of which the Bones 
are Made.—When a bone has 
been burned for a sufficient 
length of time it will be so brit- 
tle that it can be easily broken. 
If it be soaked in diluted muri- 
atic acid it will entirely lose its 
stiffness, and, if of sufficient 
length, can be tied in a knot. 
By these experiments it will be 
seen that the bones contain a 
mineral or earthy substance, 
which makes them stiff and hard, 
and a certain amount of animal 
matter, or gelatine, which binds 
them together and gives them a 
slight degree of elasticity. The 
earthy substance is mostly lime, and composes about 
two thirds of the weight of the bone.* In child- 
hood the bones are more largely composed of ani- 
mal matter than in old age. On this account, chil- 
dren are less likely to have their bones broken by 
Fig. 16. Upper portion 
of the right femur, sawn 
in two lengthwise, show- 
ing the difference of text- 
ure between the shaft 
and the extremity. 
* The color of bone in the living person is a pale-rose tint, inclin- 
ing in early life to red, in old age to a yellowish white. Bones assume 
a beautiful white when deprived of the oily fluids which pervade them. 
The specific gravity of fresh bone is greater than that of any other ani- 
mal substance. HOW WE LIVE. 
blows and falls ; but, for the same reason, they are 
more likely to become deformed by remaining in 
an improper position. The legs of young children 
are often bent out of shape by too much use of them 
before their bones are firm enough to support the 
weight of the body. In old persons the bones are 
so brittle as to break very easily, and when broken 
they do not readily unite again. 
Growth and Repair of the Bones.—The bones 
do not reach their full development before the age 
of twenty-five, and in persons who use the brain a 
great deal the skull is said to continue its growth 
much longer. The continual repair of worn-out 
parts is carried on in the bones as in the rest of the 
body.* When a bone is broken and the parts are 
brought together again, a watery substance is poured 
out of the fractured ends until the break is closed 
by a gristly formation. In due time, mineral matter 
is supplied to stiffen the gelatine thus provided, and 
the bone is finally restored to its original form and 
strength. 
Bones of the Head.—The bone which gives 
shape to the head and protects the brain which lies 
within is the skull. It is rounded on top somewhat 
like the large end of an egg, and in front and on the 
sides it has openings for the eyes, the nose, and the 
ears. The skull is composed of two compact, armor- 
like plates, with a layer of spongy bone between 
them. The dome-like top is the best possible form 
* If any red coloring-matter, such, as madder, be mixed with the 
food of a young animal, its effect will appear within a day or two in the 
changed color of the bones. HOW THE BODY IS ABLE TO STAND. 
81 
for resisting pressure. The spongy layer prevents 
the jar of a blow being felt by the brain. The upper 
jaw and the bones of the nose and the cheeks belong 
to the skull, and are immovable. The movements of 
the mouth are effected by means of the lower jaw. 
Sutures of the Skull.—The skull is made up of 
several parts joined by irregular, sawdike projec- 
tions and depres- 
sions on each side, 
very much as we 
can lock the fin- 
gers of our two 
hands together. 
These lines of con- 
nection are called 
sutures. In child- 
hood the parts of 
the skull are not 
very firmly united, but as the person grows older 
the union becomes more and more complete. The 
use of having the skull in several parts is to allow 
the brain to grow and to prevent a jar from affect- 
ing the whole skull. 
Bones of the Trunk.—The bones of the trunk 
are the pelvis, the spinal column, the ribs, the breast, 
bone, the shoulder-blade, and the collar-bone.* The 
Fig. 17.—The skull, showing the sutures. 
* Strictly, the shoulder-blade and the collar-bone form a class by 
themselves. “The Upper Extremity consists of the Arm, the Forearm, 
and the Hand. Its continuity with the trunk is established by means of 
the shoulder, which is homologous with the innominate or haunch-bone 
of the lower limb. The Shoulder is placed upon the upper part and side 
of the chest, connecting the upper extremity with the trunk : it consists 
of two bones, the Clavicle and the Scapula.” (Gray’s “Anatomy.”) 82 
HOW WE LIVE. 
pelvis, situated at the bottom of the trunk below the 
abdomen, affords a foundation for the trunk and a 
solid means of attachment for the 
legs. It consists of the sacrum, 
the coccyx, and the two hip-bones, 
arranged in the form of a basin. 
Attached to the pelvis, and ex- 
tending up the middle of the back 
to the head, is the spinal column, or 
backbone. It is made up of twenty- 
four small, flat bones called verte- 
bra,* placed one upon another with a 
pad of rubber-like cartilage between 
each two. The spine is the main 
connecting structure of bone in the 
body, gives shape 
to the trunk, and 
contains a channel 
through Avhich 
passes the spinal 
cord, an impor- 
tant center of 
nerve - distribu- 
tion.f 
The ribs, twen- 
ty-four in num- 
ber, are in pairs 
inclosing the 
Fig. 18. The pelvis, 
showing the hip-joint 
and the relative posi- 
tions of the spine and 
the femur. 
Fig. 19. 
The spinal column. 
* Of the vertebrae, seven belong to the neck, twelve to the back, 
and five to the loin. The sacrum and the coccyx are consolidated ver- 
tebras, and may be included in the spinal column, 
f When we look at the spine from the side, we see that it has a HOW THE BODY IS ABLE TO STAND. 
83 
chest. They are attached to the spinal column by 
a kind of joint which allows them to move up and 
down enough for the 
purpose of breathing. 
In front the upper sev- 
en pairs are attached to 
a strong, flat bone ex- 
tending up and down 
and called the sternum, 
or breast-bone.* 
Extending down- 
ward from the top of 
the trunk behind the 
arms, on each side of 
the spine, is a strong 
plate of bone, shaped 
like a triangle and called the shoulder-blade, or 
scapula. From the part of the shoulder-blade near- 
est the arm to the upper part of the breast-bone, 
extends a slender bone shaped much like the italic /, 
and called the collar-bone, or clavicle. This braces 
the shoulder-blade and helps to keep it in place. 
Bones of the Arms.—The single long bone be- 
tween the shoulder and the elbow is called the 
humerus. Of the two between the elbow and the 
Fig. 20.—Bones of the thorax, showing 
the shoulder-joint, the relative posi- 
tions of the spine and bones of the 
upper cavity of the trunk, and the 
shape of the ribs in a healthy chest. 
double curve bending back from the neck to the shoulders, then for- 
ward to the waist, and then back as it nears its lower extremity. A 
pivot-joint connects the two upper vertebras, and a hinge-joint connects 
the vertebrae with the skull, enabling us to turn the head and move it 
backward and forward. 
* The lowest two on each side are not attached in front, and are 
called floating ribs. The remaining three pairs are connected by bands 
of cartilage, and are called false ribs. 84 
HOW WE LIVE. 
wrist, the one more closely joined to the humerus 
is the ulna; the one which moves around the ulna 
is the radius. The bones of 
the wrist are eight in num- 
ber. The palm of the hand 
contains five, and the bones 
of the fingers and thumbs 
can be readily counted. 
Bones of the Legs.— 
The bones of the legs cor- 
respond almost entirely to 
those of the arms. That be- 
tween the trunk and the 
knee is the femur. The pa- 
fella covers the knee-joint. 
The main bone between the 
knee and the ankle is the 
tibia, and the one which 
braces it is the fibula. The ankle contains seven ; 
and there are five in the body of the foot. The 
bones of the toes, like those of the fingers, can be 
easily counted. 
Fig. 22.—Bones 
of the left arm, 
showing the ul- 
na and the radi- 
us in a twisted 
position. 
Fig. 21.—Bones 
of the right 
arm, showing 
their ordinary- 
positions. 
Arch of the Foot.—The bones of the foot are 
arranged in such a way as to form an arch. When 
the weight of the body is thrown upon the foot, as 
in walking and leaping, the top of the arch is pressed 
downward, and the bones spread outward, making 
the foot wider than before. In this way the body 
is preserved from shocks which would otherwise 
greatly iniure it.* 
* Tight shoes, and shoes made of coarse, heavy leather, are injuri- 
ous in many respects. They prevent the spreading of the foot, and HOW THE BODY IS ABLE TO STAND. 
85 
Bony Cavities of the Body.—The cavities of the 
body which are formed and protected by the bones 
are thus seen to be the 
skull, the chest, and the 
abdomen. The skull con- 
tains the brain, which is 
the most sensitive organ, 
and has no motion. 
Hence the skull is abso- 
lutely unyielding. The 
chest not only protects 
the organs within, but 
varies in size to accom- 
modate the lungs in res- 
piration. Accordingly, 
it is not only strong, but 
expansive. The pelvis 
supports the organs of 
digestion, and for this purpose is shaped like a 
basin. It also sustains the whole body on the pil- 
lars formed by the legs. It is, therefore, thick and 
unyielding. 
Fig. 23.—Bones of the legs, in theii 
relative positions. 
Bodily Movements. 
How the Muscles move the Bones.—The cause 
of motion in the body is the contraction of the mus- 
cles. In the hollow muscles the result of contrac- 
change the act of walking from a free, springing motion, to a stiff, un- 
natural gait. The bones become distorted and overlap one another, pro- 
ducing permanent deformity. The continued pressure upon the flesh 
produces corns, bunions, and ingrowing toe-nails. High heels throw 
the weight too far forward, and heels placed under the hollow of the 
foot not only prevent the spring of the arch, but quickly produce de- 
formity. 86 
HOW WE LIVE. 
tion is to diminish the capacity of the vessels which 
the muscles form. Where the muscles connect two 
bones, the contraction draws the connected bones 
toward each other. The lower jaw is drawn up- 
ward by a strong muscle called the masseter. This 
is attached to the cheek-bone, and acts directly to 
Fig. 24.—The arrangement of bones and muscles by which the arm is bent; 
A, the radius ; B, the elbow ; C\ biceps ; E) ulna ; F, triceps ; G. shoulder- 
joint. 
bring the jaws together. The arm is bent by a 
strong muscle called the biceps. This is attached at 
one extremity to the shoulder-blade, and at the other 
to the radius just below the elbow.* The opposite 
movement, by which the arm is straightened, is 
caused by a similar muscle, called the triceps, on 
the opposite side of the arm. This, however, is at- 
* When the biceps contracts, the radius is drawn upward toward 
the shoulder; but, as the tendon of the biceps is attached to the radius 
so near the elbow, it plainly requires more muscular effort to bend the 
arm than would be required were the tendon of the biceps attached 
nearer the wrist. The enlargement of the elbow-joint, by raising the 
tendon away from the arm, brings it more nearly at right angles to the 
radius, and thus gives it more effect in bending the arm than it would 
have were it parallel to the radius. HOW THE BODY IS ABLE TO STAND. 
87 
tached to the ulna.* The muscle which throws one 
leg across the other reaches from above the hip on 
the outside to below the knee on the inside, and is 
called the tailor’s muscle, or sartorius, because it is 
the one which a tailor uses in taking his peculiar 
position on the bench. Wherever a twisting mo- 
tion is to be produced, there is a similar arrange- 
ment. A rotary movement of the eyeball is pro- 
duced by a muscle passing through a pulley-like 
loop. 
How Shocks are Distributed.—Every one knows 
that when a person needs to jump from a high place 
the shock felt will be much less if the body is al- 
lowed to bend freely than if it is kept rigid. The 
hand of a catcher who wishes to feel the sting of 
the ball as little as possible is allowed to move back- 
ward when the ball is caught. It will be readily 
seen that, if in these cases the limbs were held rig- 
idly in a straight line, the firm ends of the bones 
could not fail to strike heavily against each other, 
much as the buffers of two railway-cars do when 
the cars collide. But when the joints are bent and 
the muscles are relaxed, the main force of a shock 
is expended in further bending the joints, and the 
shock felt by the limbs in the direction of their 
length is very slight. 
In jumping, if we strike upon the toes, the shock 
is first moderated by the arch of the foot, which acts 
like a spring. The force of the shock is further dis- 
tributed at the ankles, the knees, and the hips, by 
* This antagonistic arrangement, and this alternate action of the 
muscles, are essentially the same in all the hinge-joints. 88 
HOW WE LIVE. 
the three curves in the spine, and lastly at the joint 
which connects the spine with the skull. 
Hygiene of the Bones. 
I. The food and drink that we take must contain 
enough lime to nourish the bones,* 
11. In childhood, before the bones harden, they 
should not be made to sustain heavy weights, nor 
should they be subjected to a continuous press- 
ure.j* 
111. Exercise, giving the proper amount of press- 
ure and strain, is necessary to promote the growth 
and nurture of the bones. 
IV. The bones of the foot should not be com- 
pressed so as to prevent the free spring of the arch 
and the spreading of the bones, when the foot is 
called upon to sustain the weight of the body. 
V. No tight bands should be worn about the 
ribs to interfere with the movement of the bones in 
breathing. 
VI. We should sit and stand erect, so as to pre- 
vent the distortion of the bones which comes from 
the habit of bringing the shoulders forward and 
bending the head down. 
VII. We should avoid resting one arm higher 
* Farmers have long noticed that cattle often do not thrive in an 
old pasture. Their bones become tender and are easily broken, and 
the whole body suffers in health. The reason is that those elements of 
the soil that make bones have been used up, and the remedy is to sup- 
ply fertilizers that contain lime. 
t A baby’s legs are often made crooked by trying tco early to make 
it walk. In school, many a child has been deformed by sitting on so 
high a bench that its feet can not touch the floor. HOW THE BODY IS ABLE TO STAND. 
89 
than the other, as this practice tends to produce a 
permanent curvature of the spine. 
VIII. When a bone is injured or a joint sprained, 
we should keep perfectly quiet until the part is fully 
recovered. 
Something to Find Out. 
1. What are the appearance and composition of 
a bone after it has been thoroughly burned ? 
2. What are the appearance and condition of a 
bone after it has been soaked in diluted muriatic acid ? 
3. In making soups, what ingredient is derived 
from the bones, and how is this ingredient obtained ? 
4. What is the comparative effect of a sudden 
blow upon the bones of young and of old persons ? 
What is the effect of pressure ? 
5. When bones are broken, what are some of the 
conditions necessary for their repair? 
6. In what plays is there particular danger of 
getting bones broken ? 
7. Why is the skull at the top rounded in the 
shape of a dome ? 
8. What animal is so constructed that its upper 
jaw can be thrown back ? 
9. Why is the pelvis a large and very strongly 
constructed bone ? 
10. What is the use of the rubber-like cartilages 
between the vertebrae of the spinal column ? 
11. After a day of active exercise in work or 
play, why are we shorter than when we first arose 
in the morning ? 
12. What effect does wearing a tight band around 
the waist have upon the shape of the ribs ? upon HOW WE LIVE. 
the movement of the ribs ? upon the movement of 
the diaphragm? upon breathing? upon the posi- 
tion of the organs of the chest and abdomen ? upon 
the circulation of the blood ? 
13. Why should the soles of shoes be broad? 
Why should the heels be broad and low? Why 
should the upper leather be soft and pliable ? 
14. Why do people wear tight clothing and tight 
shoes ? 
15. What reason is there for making shoes with 
high heels, or with the heel in the hollow of the 
foot ? 
16. In what way are corns produced ? 
17. What name is applied to the lower limbs 
when the bones have become permanently bent ? 
18. In the bones of the lower arm, which bone is 
attached at the elbow, and which at the wrist ? 
19, When you saw in two, lengthwise, a beef Or 
mutton bone taken out of the leg, how does the 
interior appear ? 
20. Why are the bones and joints of the toes so 
frequently deformed ? 
21. Why does a person in catching a ball draw 
his hands back the moment the ball touches them ? 
22. Why do we strike on the ball of the foot 
when we jump ? 
23. Why, in walking or jumping, is it best to 
keep the joints bent ? 
24. When we unexpectedly step down a few 
inches, what effect is produced ? Why ? 
25. Why do so many people have a stiff, awk- 
ward gait ? CHAPTER VIII. 
HOW THE BODY IS COVERED. 
one who has met with an accident, by which a piece 
of the skin has been torn off, can understand how 
important it is that there should be some sufficient 
protection to the muscles and other sensitive organs 
which lie near the surface of the body. Besides the 
pain caused, the removal of the skin allows poison- 
ous or irritating substances to enter and injure the 
body. In addition to these well-known protective 
uses, there are many other offices which the skin 
performs. It assists in removing waste matter from 
the system, absorbs matters brought in contact with 
it, is the termination of the nerves of touch, aids the 
lungs in taking in oxygen and giving out carbonic 
acid, regulates the temperature of the body, and, in 
general, not only defends the organs within, but 
helps them when they are unable to do their full 
amount of work. It also, with the hair and its 
other appendages, does much to beautify the per- 
son and give expression to the emotions and the 
thoughts. 
The Usefulness of the Bodily Covering.—Every 92 
HOW WE LIVE. 
The Skin. 
General Structure of the Skin.—The thickness 
of the skin varies in different parts of the body. 
Where it is much exposed to wear, as on the soles 
of the feet or the palms of the hands, it becomes 
very thick and is called a callus.* In other parts it 
is very thin and delicate. At the ends of the fin- 
gers and the toes, where unusual protection is re- 
quired, it grows into shield-like plates called nails. 
On the scalp, where special protection of the brain 
is needed, it puts forth a thick covering of hair. 
Layers of the Skin.—The skin is divided into 
two principal layers. The outer one is called the 
scarf-skin, cuticle, or epidermis. It is made up of little 
cells flattened into scales. It has no blood-vessels or 
nerves, and may be cut or pinched without giving 
pain. As the cells near the surface become dry and 
hard from lack of nourishment, they fall off and new 
ones from beneath take their place.f The lower 
part of the scarf-skin contains the pigment, or color- 
ing-matter, which determines the color of different 
races and different individuals.;}; The inner layer 
* When this thickened skin is at the same time continually sub- 
jected to hard pressure, as by tight shoes, it forms an excessively hard, 
horny lump called a corn. Any means of softening the lump, as soak- 
ing it in warm water, together with the removal of the cause, will often 
remedy the evil. 
j- It is these worn-out cells, or scales, that separate from the skin in 
bathing. They also constitute the dandruff which forms on the head 
and comes off in small, white particles, especially when the hair is 
combed or brushed. 
X When the amount of coloring-matter in the pigment-cells is very 
slight, it produces a blonde complexion ; when greater, a brunette. HOW THE BODY IS COVERED. 
93 
of the skin is called the true skin, cutis vera, or derma. 
The part of this nearer the surface is composed of 
Fig. 25.—Vertical section of the skin, magnified : a, scarf-skin ; b, pigment- 
cells ; c, papillae ; d, true skin ; e, f \ fat cells; g, sweat-glands ; h, out- 
lets of sweat-glands; z, their openings on the surface of the skin ; k, hair- 
follicle ; /, hairs projecting from the skin ; m, hair-papilla ; n, hair-bulb; 
0, root of hair ; p, openings of oil-glands. 
The colors of the different races depend upon the kind and amount of 
pigment in these cells. The amount of coloring-matter is increased by 
exposure to heat and light. Every one knows that those who spend 
much time in the open air, especially in summer, become tanned and 
freckled, and that when winter comes again, or they remain in-doors 
for a time, the tan and freckles mostly pass away. This is because the 
light and the heat increase the pigment. When this takes place in 
spots, it causes freckles only; when it affects the whole exposed surface, 
it causes tan. 
When persons of a light complexion go from countries distant from HOW WE LIVE. 
94 
little elevations called papilla. These contain blood- 
vessels and nerves, and from some of them arise the 
hair-follicles, or the openings through which the 
hairs reach the surface of the skin. Below the pa- 
pillae lies the main part of the true skin ; and be- 
tween the true skin and the flesh is a layer of fat, 
which varies in thickness in different persons. 
How the Skin is kept Soft.—All over the sur- 
face of the body are little tubes which descend into 
the true skin, like the finger of a glove with the end 
downward. Some of these tubes end in little bags 
somewhat resembling clusters of grapes. These 
groups of bags are called sebaceous glands.* They 
collect oil from the blood and pour it out through 
the hair-follicles upon the scarf-skin to keep its cells 
from falling off too rapidly, and in this way the 
skin and the hair are kept soft and pliable. 
How the Skin casts out Waste Matter.—In the 
layer of fat beneath the true skin lie the coiled ends 
of tubes, which reach to the surface of the skin. 
These filter off from the blood the perspiration, and 
are called the sweat-glands.f The perspiration con- 
the equator into the very warm regions between the tropics, they be- 
come almost as dark as the native inhabitants. When the natives of 
very hot countries live for a long time in cooler latitudes, their com- 
plexion gradually becomes lighter. In some persons the pigment is 
entirely wanting. Such persons have a pallid complexion and pink 
eyes, and are called albinos. 
* The oily contents of these glands sometimes harden and form the 
black specks which appear in the skin. 
f A magnifying-glass will disclose on the ridges on the palm of the 
hand over three thousand openings of the sweat-tubes in every square 
inch. There are also great numbers on the soles of the feet; and even 
where least numerous, as on the back, there are about four hundred HOW THE BODY IS COVETED. 
95 
sists chiefly of water, but contains also a certain 
amount of waste material. In this way the skin 
aids in keeping the body free from impurities. 
Other Means of casting out Waste.—A consid- 
erable part of the waste matter of the body passes 
off through the kidneys. These organs lie in the 
abdominal cavity, one on each side, just below the 
“ small of the back.” They absorb from the blood 
impurities which can not be expelled at the lungs. 
The waste which passes off through the kidneys 
and through the skin is much alike, and in their 
action they assist each other. When the kidneys 
are diseased, the skin does more work; and when the 
skin is out of order, as from the effects of a cold, 
the kidneys become more active. 
How the Skin regulates Heat.—lt is a familiar 
fact that, in very warm weather, the heat of a room 
can be lessened by sprinkling the floor. This is be- 
cause heat is used up in changing the water into 
vapor, and so is not able to increase the tempera- 
ture. The same is true of the perspiration which 
is thrown out from the sweat-glands. Usually the 
perspiration is poured out so gently that it is not 
noticed, and is said to be insensible* But, in very 
warm weather, or when the body is heated by exer- 
present to every square inch of surface. Indeed, it has been calculated 
that there are twenty-eight hundred sweat-glands, on the average, in 
every square inch of the body, making a total in an average-sized man 
of about seven million, which is equivalent to twenty-eight miles of 
the tubing, since each tube is a quarter of an inch long.—{“ The Skin 
and its Troubles.”) 
* The insensible perspiration of an adult person amounts to about 
twenty ounces in twenty-four hours. 96 
HOW WE LIVE. 
cise, it forms visible drops. The more rapidly the 
perspiration flows out, and is changed to vapor, the 
less we feel the heat.* But we need to drink much 
more, in order to keep a proper amount of moisture 
in the body. 
How the Skin Absorbs.—The true skin contains 
a great number of blood-vessels,f which distribute 
nourishment to the papillae, the roots of the hair, 
the oil-glands, and the other parts of the skin ; and 
which carry back the exhausted blood to the heart. 
It also contains lymph-vessels, which commence as 
little spaces between the cells and fibers of the skin, 
and gradually form tiny tubes to carry away the 
lymph into the blood. Whenever any substance 
soaks through the scarf-skin, it is caught up by the 
lymph-vessels and the veins, and is hurried away to 
various parts of the system, 
Why the Skin should be kept Clean.—lt is plain 
that the natural waste of the scarf-skin, and the 
* It is on this account that “ fire-kings ” can remain in ovens heated 
as high as 6ooc. 
f The presence of red blood in these blood-vessels gives to the skin 
its ruddy color. When from any cause the blood rushes to the skin, 
this ruddiness is increased. When this rush of blood is supposed to 
be caused by some emotion, the effect is known as blushing. When 
from any cause the blood is withheld from these vessels, its absence is 
known as pallor, or paleness. 
\ The power of the skin to absorb is illustrated by the fact that 
persons have been kept alive by baths of soup and other nourishment. 
It may have been for a similar purpose that baths of wine have been 
sometimes used by luxurious persons. On the other hand, it is well 
known that persons whose work compel! them to handle poisonous 
substances frequently lose their health by continual contact with the 
materials used. Similar effects are sometimes produced by so slight a 
cause as a kiss from one who is affected by disease. HOW THE BODY IS COVERED. 
97 
pouring out of oil and perspiration from the glands, 
must result in the accumulation of much impurity 
upon the surface of the skin. It is plain, also, that 
if this mass of impurity is allowed to remain, it 
must not only be in itself offensive, but must de- 
range the action of the organs of the skin. The 
amount of impurity thus thrown out of the body is 
much increased by any unusual excitement of the 
nerves caused by excessive emotion. Besides these 
collections, the dust and dirt which come upon the 
skin in the course of our ordinary work require fre- 
quent removal. If these impurities are not speedily 
removed, they derange the action of the skin, and, 
through the skin, the comfort and capacity of the 
whole body.* 
How to keep the Skin Clean.—The only means 
of keeping the skin clean is frequent and thorough 
bathing of the entire body. This should be attend- 
ed to every day, if possible. If from any cause 
this frequency is not possible, the nearest approach 
to it should be made. Under any ordinary circum- 
stances, such a bath may be taken by every person at 
* Other animals show us the good of being clean : a badly groomed 
horse is never sound or spirited, and a dirty pig puts up one fourth 
less flesh than a clean one. Yet it may be feared that some hu- 
man beings are only thoroughly washed at birth and at burial.— 
(Mapother.) 
Many an evil action is the remote result of a neglect of cleanliness. 
When it is habitual, it brings about a degraded state of mind; and, 
even when it is temporary, its irritating effect upon the disposition is 
often noticeable. It is a fair question whether, in many cases, a bad 
boy might not be converted into a good one by means of a bath and 
a change of clothes. The public baths in many cities are really very 
important agencies in suppressing wrong-doing. 98 
HOW WE LIVE. 
least once a week. Besides this bathing of the whole 
body, those parts which especially need it should be 
washed as often as any impurity is discovered upon 
them. For merely cleansing the body, tepid or 
warm water is the most effective. But such a bath 
is relaxing in its effect, and should not be used very 
often. The cold morning-bath is very beneficial to 
perfectly healthy persons, not only for its cleansing 
power, but also for its stimulating effect. If a bath- 
tub is used, a simple plunge will in most cases be 
sufficient. The most convenient and profitable morn- 
ing-bath within the reach of a majority of persons is 
the sponge - bath. This requires only a basin of 
water, a sponge or wash-cloth, and a towel. Only 
so much soap as is necessary should be used. 
If the skin does not recover its warmth in a 
short time by vigorous rubbing of the body with 
a coarse towel, the person is not in proper condi- 
tion to profit by cold baths. The other forms of 
bathing are either medicinal in their nature, or par- 
take of the nature of luxuries.* 
* Sea-bathing is a very popular form of the natural bath, and it is 
preferable to bathing in river-water or spring-water, because the sea is 
seldom so cold as are the latter. A sea-bath has also another great 
advantage over all other forms of bath, and that is that it is taken in 
the purest air possible ; and in considering the effects of sea-bathing, 
it is impossible to separate the effects of sea-air from that of the sea- 
water. The sea-bather is also constantly inhaling the spray of the sea- 
water, and thus obtains whatever benefit is to be got in this way. If 
he can swim, he enjoys all the benefit of exercise. The motion of the 
water and the buffeting he gets from the waves act as a powerful ex- 
citant to the skin ; and, lastly, the salt in the water adds considerably 
to the stimulating action. Reaction more readily occurs after a sea- 
bath than after a river-bath.—(“ Baths and Bathing.”) HOW THE BODY IS COVERED. 
99 
No kind of full bath should be taken within less 
than two hours after a hearty meal, because the 
process of digestion will not allow so much distrac- 
tion of bodily energy. The soap used in bathing 
should not be very strong, because such soap will 
remove too much of the scarf-skin, and, in cold 
weather especially, will cause the skin to chap. 
The Hair. 
What it Is.—The follicles from which the hairs 
grow, and the oil-glands which cling to their roots, 
have already been mentioned. The hairs them- 
selves are modified forms of the scarf-skin. Human 
hairs are solid, but the central parts are made up of 
cells loosely packed together to form a pith. The 
shaft of a hair is the part outside the skin. The root 
is the part which lies below the surface. At the 
side of the hair are little muscles, by which it may 
be made to “ stand on end.” The color of the hair 
is due to a pigment in the cells. The flatter the 
hairs are, the more readily they curl.* 
How to keep the Hair Healthy.—The health of 
the hair depends mainly on the general health of 
the body. A slight, continuous shedding of the 
hair, especially in the spring and autumn, does not 
indicate ill health. The hair should always be kept 
* The hair upon the head and the face protects from cold, and 
shields the head from the rays of the sun in hot climates. It also 
breaks the force of a blow upon the head. The eyebrows prevent the 
perspiration from running from the forehead upon the lids. The eye- 
lids protect the eyes from dust and other injurious matters. The short, 
stiff hairs of the ears and the nose arc also for protection to these open- 
ings. HOW WE LIVE. 
clean by frequent washing, and by thorough but 
not rude brushing. Cutting the hair tends to pro- 
mote its growth. Great care should be taken to 
keep the scalp from undue pressure from any cause, 
and any covering of the head which prevents the 
free access of air is to be avoided. 
leads to weakness of the body will injure the hair. 
Sometimes early grayness, or the loss of the hair, is 
common in a family. Sometimes they result from a 
local disease of the scalp; but usually they indi- 
cate a general weakness of the body, or some over- 
tasking of the mind or the emotions. Severe ill- 
ness, fear, worry, anxiety, or hard mental work, 
may cause either of these results.* Various hair- 
dyes and similar preparations are sometimes used 
to restore the growth or the color of the hair; but 
most of them contain poisonous substances, which 
are liable to enter the skin by absorption, and often 
produce serious results. 
Thinning and Grayness of the Hair.—Whatever 
Clot]ling. 
Why the Body should be Clothed.—The body 
needs to be protected by clothing as much as the 
flesh and other organs need the protection of the 
skin. Savages, and people who live in warm coun- 
* The hair may become white or gray in the course of a few hours. 
In most cases this has occurred in connection with intense mental emo- 
tion. The cases of Marie Antoinette and Sir Thomas More are widely 
known, and more carefully authenticated cases leave no doubt that 
such a change may occur. It is supposed to be caused by the entrance 
of air into the pith of the shaft; but how its entrance there is effected 
is difficult to imagine. HOW THE BODY IS COVERED. 
tries, wear much less clothing than those who are 
refined, and who live in colder climates. Those 
who go without shoes come to have the skin on 
their feet so tough and thick that they can walk 
and run without pain, even over stony surfaces; 
and in savages somewhat the same effect is pro- 
duced h}" the general exposure of the body. But 
in civilized countries the general use of clothing 
has made it necessary, not only as a protection 
from hurt and from extremes of heat and cold, but 
also as a means of adornment. 
How the Body should be Clothed.—The clothes 
we wear should be carefully adapted to the needs 
of the body and the demands of good taste. Parts 
specially exposed to injury, as the feet, need the 
strong protection of shoes; and these need to be 
heavy or light according to the service which they 
are intended to perform. The head needs such a 
covering as will keep it warm in cold weather, and 
cool in warm weather. It should also be such as 
will shield the eyes from excessive light. Flannels, 
other woolen goods, and furs, are best adapted to 
retain the heat of the body. Hence they should 
be used in cold weather. Cotton, linen, and silk 
readily conduct the heat from the body, and should 
therefore be worn when the weather is warm. 
Light colors reflect much heat and radiate little; 
hence are warmer in winter and cooler in summer* 
* Very many colds are caused by insufficient clothing. Whenever a 
sense of chilliness is felt in any part of the body, it is a signal from the 
nerves that more protection is needed; and this warning should be heeded, 
no matter in what season of the year, or at what time of day, it is given. 102 
HOW WE LIVE. 
Special care should be taken to keep all parts of 
the body absolutely dry at all times. Whenever it 
Fig. 26.—Deformity of the ribs, caused by wearing clothing tight at the waist, 
is necessary to walk in the wet, the feet should be 
protected by overshoes, and water-proof garments 
and an umbrella should always be used when they 
are needed. But, as overshoes and water-proofs not 
only keep the moisture out, but also prevent the 
perspiration from escaping, they should never be 
worn in dry weather, or kept on in-doors. If, from 
unavoidable causes—as from excessive perspiration, 
being caught in a shower, or stepping into the water 
■—any portion of the clothing becomes wet, it should 
be immediately removed, and dry clothing should 
be put on.* 
* The neglect of these simple precautions has caused almost num- HOW THE BODY IS COVERED. 
103 
The clothing should never be worn so tight as 
to interfere with the entire freedom of the body. 
Very tight shoes, and tight clothing at the waist, 
are the two most serious evils in modern dress.* 
Since the skin is full of pores, some of which 
give off waste, and some of which absorb matter 
from the outside, it is very important that these 
pores be kept open. As the skin covers the en- 
tire body, it rs also important that every part of 
it should be kept soft and elastic, so as not to 
press uncomfortably upon the delicate organs 
beneath. 
Hygiene of the Skin. 
From these facts, and from the foregoing discus- 
sion, the following hygienic laws in regard to the 
skin become obvious : 
I. The skin should be kept clean, so as to allow 
waste matter to be readily carried off. 
11. We should exercise freely, so that the blood 
may circulate properly in the skin. 
111. The skin should be frequently rubbed, to 
help the circulation of the blood, to excite the secre- 
berless colds, catarrhs, and more serious diseases. Pneumonia and 
consumption often originate from so apparently slight a cause as wear- 
ing insufficient wraps or wetting the feet. . 
* The apparent tendency of the times to more freedom in these 
articles of dress is an evidence of the benefits of physiological study ; 
but a great amount of instruction is still needed. Shoes with high 
heels, by throwing the feet out of their natural position, frequently 
cause serious injury to various parts of the body, especially the eyes. 
Care should be taken to avoid any article of clothing which contains 
poisonous coloring-matter. No clothing should be worn which leaves 
any indication of color upon the skin. 104 
HOW WE LIVE. 
tion of oil which softens the skin, and to keep the 
scarf-skin from clogging the pores. 
IV. Draughts of air and sudden chills should be 
avoided, as they drive the blood away from the sur- 
face, cause the skin to shrink, and close up the 
pores. 
V. In handling poisonous matter of any kind, we 
should be careful not to let it come in contact with 
the skin, lest it be absorbed. 
VI. When, from any cause, we have but little 
vitality, we should not take a cold bath, because 
there is danger that reaction may not follow. 
VII. That the hair may be vigorous, it should 
be kept clean, and brushed often, and the dry, harsh 
ends should be clipped off. 
VIII. The scalp should be kept clean and be 
sometimes gently rubbed; then it will supply the 
hair with all needed nourishment, and will render 
the use of oil and “ hair-invigorators ” unnecessary. 
IX. Clothing should be changed with the tem- 
perature, to protect the skin from extremes of heat 
and cold. 
X. Clothing worn next to the skin is soon 
filled with waste matter, and should be frequently 
changed. The same clothing should not be worn 
day and night. 
XI. The clothing should not be worn so tight as 
to drive the blood away from the surface of the 
skin, to interfere with breathing, or to prevent the 
free use of the muscles. HOW THE BODY IS COVERED. 
105 
Something to Find Out. 
1. Why are the nails upon the fingers and toes 
harder than other parts of the skin ? 
2. Why is the skin of the head furnished with a 
thick covering of hair ? 
3. What becomes of the waste matter contained 
in the “ insensible perspiration ” ? 
4. How much waste matter is thrown off from 
the skin in one year ? 
5. What harm comes from breathing air filled 
with this waste matter ? 
6. Why should the plaster walls and ceiling of a 
school-room be frequently whitewashed with lime ? 
7. Why is out-door air better to breathe than the 
air of inhabited rooms ? 
8. How may the air of inhabited rooms be kept 
pure ? 
9. What causes the peculiar effect upon the skin 
which is called “ goose-flesh ” ? 
10. When “ goose-flesh ” appears, or the skin be- 
comes suddenly pallid, what should be done ? 
11. How does the skin appear when the blood 
circulates freely through it ? 
12. What internal organs are relieved by the free 
circulation of the blood in the skin ? 
13. To what danger are nurses exposed by be- 
ing with persons who are ill ? 
14. What particular danger should be guarded 
against in surgical operations ? 
15. Why, in taking a bath, is tepid water usually 
safer than cold water ? HOW WE LIVE. 
16. In what way is an excessive use of soap in a 
bath injurious ? 
17. Why is a boy, when dirty, more liable to do 
a mean thing, than when he is clean ? 
18. Are all children to blame for an untidy ap- 
pearance ? Should they be reproached for it ? 
19. Why is the practice of wearing fur caps and 
close-fitting hoods injurious ? 
20. What kind of head-coverings are the best 
for summer ? 
21. What peculiar head-coverings are worn by 
people in very hot climates ? 
22. Why do we need more clothing when asleep 
at night, than when we are about in the day-time ? 
23. Why should we take off rubber overcoats 
and overshoes immediately on coming into the 
house ? 
24. When we are exposed to great cold or heat, 
why is woolen clothing better than cotton ? 
23. When our feet become wet and cold, how 
may we avoid chilblains ? 
26. Why do people in the Arctic regions dress 
in the skins of fur-bearing animals ? 
27. In case of a slight burn or a scald, what part 
of the skin rises into a blister ? 
28. When the skin is burned, why should the air 
be at once excluded ? 
29. Of what use are linseed-oil, plasters of flour 
mixed with water, and plasters of clay, in case of a 
burn ? 
30. What indicates that the true skin has been 
cut or burned ? CHAPTER IX. 
HOW BODILY MOTION IS DIRECTED. 
Bodily Organs must act in Harmony.—lf each 
of the internal organs of the body should move 
without regard to the movements of the other 
organs, life could not exist; for life can be sustained 
only by all the organs acting together in harmony. 
If each of the external organs, as the arm or leg, 
were independent in its motions, the body as a 
whole would be unable to do any useful work, and 
the mind could not carry out its purposes in any 
direction. In order that nurture may go on in the 
body, and that the mind may execute its plans, all 
bodily movements, therefore, must be under orderly 
control. This control is effected by means of the 
nerves. 
How the Nerves are Distributed.—Throughout 
The Nervous System. 
the body there is a nervous system, which in plan 
and distribution is very much like the system of 
blood-vessels. The nerves, starting from a nervous 
center, divide and subdivide, until they become 
exceedingly minute, hair-like threads extending to 
every organ in the body. In the skin they form a HOW WE LIVE. 
net-work so close that the finest needle can not 
pierce the skin without coming in contact with 
some of them. 
Like the blood-vessels, the nerves are double, one 
set going out from the nervous center, and the other 
returning to it. Unlike the veins and the arteries, 
the two kinds of nerves are not distinct, but their 
fibers unite so closely that they everywhere appear 
as a single thread. 
Nerve-Matter.—The nerves are made up of two 
kinds of matter, white and gray. Under the micro- 
scope the white matter appears as minute threads 
and the gray as tiny cells. The white matter is 
much greater in quantity than the gray, but the two 
are found together in all the nerves of the body. 
The Brain.—The principal nerve-center, corre 
Fig. 27.—The brain inclosed in its membranes, and the skull: a, b, c, con- 
volutions of the cerebrum; d, the cerebellum; e, medulla oblongata j 
/, upper end of the spinal cord ; g, hy t, k, central parts. HOW BODILY MOTION IS DIRECTED. 
109 
spending to the heart in the circulation, is the brain. 
It occupies the whole cavity of the head, and is care- 
fully protected from injury by the skull. The front 
and upper part of the brain, about seven eighths of 
Fig. 28.—Upper surface of the cerebrum, showing the convolutions of the 
brain and its double structure. 
the whole, is called the cerebrum; the back and lower 
portion, the cerebellum. 
The interior mass of the brain is composed of 
white matter, but the entire surface has a thin cov- 
ering of gray. The surface of the cerebrum is made 
up of irregular rounded ridges, or convolutions, giv- 
ing to it a large amount of surface.* In the cere- 
* The convolutions of no two brains are exactly alike. In infancy 
they are scarcely visible, but they deepen and become more marked 
with age. In the civilized races the brain convolutions are deeper and 
much more numerous than in savages. They are also more extensive in 
a studious and thoughtful person than in one who does little thinking. 
The greater the number and depth of the convolutions, the greater is HOW WE LIVE. 
bellum the ridges are parallel and less rounded. A 
deep indentation extending from front to back di- 
FIG. 29.—The cerebrum, the cerebellum, the spinal cord, and the general 
distribution of the nerves. 
vides the brain into parts, so that in reality the brain 
is double, corresponding to the pairs of the external 
the amount of brain-surface, and the greater the amount of gray matter 
which covers the surface. It is therefore supposed that the gray mat- 
ter increases ■ with study and thought, and with any active business 
which depends upon thinking and demands intelligent control. 
It is estimated that in some of the most perfect human brains there 
are nearly eight hundred square inches of surface. HOW BODILY MOTION IS DIRECTED, m 
portions of the body. From the nervous mass with- 
in the skull twelve pairs of cranial nerves extend to 
different parts of the head and face. 
The Spinal Cord. —From the brain the spinal 
cord, the great center of nerve-distribution, extends 
downward through the spinal column to the lower 
extremity of the trunk. An enlarged part of this 
cord, which lies next to the cerebellum and extends 
below it, is called the medulla oblongata. Thirty-one 
pairs of nerves issue from the spinal cord and ex- 
tend to the different parts of the trunk and the 
limbs. These are called spinal nerves. 
The Ganglions.—Each of the nerves sent out 
from the spinal cord is in two parts, one coming 
out of an opening on the back side of the spinal col- 
umn, and the other from a similar opening in front. 
These parts soon unite and form a single nerve, and 
at their point of meeting is a little bunch of nervous 
matter called a ganglion. These ganglions form a 
row on each side of the spinal cord ; but, as each 
lies in the course of a single nerve, they have no 
direct communication with each other. 
Sympathetic System.—Another row of gangli- 
ons lies on each side of the spinal column deeper 
down. They are connected throughout their whole 
extent, and form an important center of nervous 
force. From this center, nerves extend to the heart, 
the lungs, and the other vital organs. Small threads 
of nervous matter serve to unite these ganglions to 
the nerves that issue from the spinal cord. 
Use of the Nerves.—As we have seen, each 
nerve issues from the spinal cord in two parts; HO W WE LIVE. 
and, though these parts unite and form a single 
thread, each part has a distinct function. The sec- 
tion which issues from the back part of the spinal 
cord carries to the brain impressions derived from 
objects, and is called the sensory nerve; the one that 
issues from the front part carries orders from the 
brain to the muscles so as to direct motion, and is 
called the motor nerve. 
For example, the naked toe comes in contact 
with a live coal. A message is immediately sent 
along the sensory nerve to the brain, telling the 
mind that the toe is burning. The mind at once 
telegraphs back along the motor nerve to the proper 
muscle an order to draw the toe away from its dan- 
gerous position. The muscle obeys, and the toe is 
saved. 
Direct Nerve-Action.—When the mind gives a 
command to a muscle, the message starts from the 
brain, and we are conscious both of the order given 
and of the act performed. This is called direct 
nerve-action. To perform this direct action, the 
mind must be informed, or intelligent, in regard to 
the matter in hand. It must have a clear purpose, 
and must issue a clear command.* 
Reflex Action.—Movements of the vital organs, 
over which the mind has no control, are constantly 
* When a pupil is intent on the study of a subject, and takes all 
possible pains to understand it, the mind controls every step, the nerve- 
action is direct, and both the brain and the mind grow. When he is 
engaged in learning and reciting the words of a text-book, with little 
or no attention to the thought, the mind is only half conscious, the 
nerve-action is almost automatic, and neither the brain nor the mind 
is benefited. HOW BODILY MOTION IS DIRECTED. 
113 
going on, and there are many movements of the ex- 
ternal organs which are automatic, or unconscious. 
Such movements have their origin, not in the brain, 
but in the other nervous centers, principally in the 
ganglions and the spinal cord. This unconscious 
movement is called reflex action. 
Reflex action has control of the vital organs, so 
that the processes of life go on without the action 
of the will. The mind has no direct control over 
the action of the heart, the liver, or any other of the 
vital organs. Were vital action under the control 
of the will, the mind might sometimes forget, and 
then life would cease. Reflex action has also gen- 
eral care of the body when the brain is at rest and 
the mind is asleep.* 
Sympathetic Action.—While the lower nervous 
centers control general vital action, the second sys- 
tem of ganglions has a peculiar function. This gan- 
glionic system, as a nervous center, sends nerves 
* Breathing is partly under the control of the will. We can sus- 
pend our breath for a brief time, but soon the motion of breathing will 
be resumed in spite of the will. A case is on record of a man who 
could by an effort of his will control the beating of the heart. He tried 
the experiment of stopping his heart “ once too often,” and it never 
began again. 
The care of the body during sleep is shown when the hand brushes 
away a fly that lights on the nose, but does not waken the mind. 
Coughing is caused by spasms of reflex action operating upon the 
muscles in the lungs. When a bit of food gets into the trachea, the 
cough-spasm throws it out. Diseases of the lungs produce the same 
feelings as the presence of foreign substances, and hence lung-diseases 
are accompanied by coughing. Sneezing is a similar spasm produced 
by foreign substances or disease in the nose. The hiccough is a nervous 
spasm of the diaphragm, caused by exhaustion, as from excessive laugh- 
ter. or from the effect of alcohol. 114 
HOW WE LIVE. 
to all the vital organs, and these organs are thus 
placed in direct communication and sympathy with 
one another. This nervous connection is called the 
sympathetic system. When the stomach is out of 
order, the sympathetic nerve gives notice, and the 
heart and lungs sympathize and become deranged 
in action. Disturbance in one organ is felt in all the 
others.* 
Habit and Training.—ln every action which 
comes from thought, the mind, through the brain, 
directs the first steps. When the actions are re- 
peated a sufficient number of times, the muscles be- 
come accustomed to the movement, and the act is 
performed with ease. When this is the case, the 
direction of such acts is given over to the lower 
nervous centers, and the actions are performed with 
little or no consciousness. 
The name given to this unconscious repetition 
of an action is habit.f The precision and rapidity 
* This sympathy gives rise to many needless fears. A person eats 
too much, and the stomach labors hard to get rid of the oppressive load. 
In sympathy with this effort, the beat of the heart becomes feeble and 
irregular. Then the terrible fear comes that the heart is diseased, and 
that death is near. The doctor comes, laughs at the fears, gives a little 
mustard, and the patient is well the next day. 
The use of tobacco produces “ heart-burn,” a trouble of the stomach, and 
this in turn, through sympathetic action, causes palpitation of the heart. 
f Habits once formed are difficult to overcome. ' Habits formed in 
youth are the most lasting. The old man is slovenly because as a boy 
he was untidy. The fine scholar can not in his oration entirely get rid 
of the inelegant expressions of his childhood. The cruel boy becomes 
the brutal man. 
Good habits are equally durable. The kindly acts of the boy or 
the girl ripen into kindness in the man or the woman. When effort to 
do things well becomes a fixed habit, it makes life rich in well-doing. HOW BODILY MOTION IS DIRECTED. 
115 
of action which come from habit constitute skill; 
and the method by which skill is obtained is train- 
ing* The training which converts acts into habits 
relieves the mind and the brain, and leaves them 
free to study new things and to perform new 
acts. 
Exercise of the Nerves.—Like the other parts 
of the body, the nerves require exercise. The food 
furnishes the elements of nerve-growth, but exer- 
cise is necessary to make their growth vigorous and 
to secure strength. When the mind is engaged in 
observing objects, finding out their qualities, and 
comparing them with other objects, it is giving 
direct exercise to the sensory nerves. When the 
hands are doing something under the direction of 
the mind, the motor nerves are brought into exer- 
cise. In both these cases, and in all thinking, the 
brain is exercised. 
If nerve-exercise is omitted, the whole body suf- 
fers, the vital organs are feeble in their action, the 
blood moves slowly in the veins and the arteries, 
waste is imperfectly made up, the muscles become 
flabby and weak, and the brain is so little nourished 
that at last it becomes incapable of vigorous action. 
The starved mind, working through the starved 
brain, gradually loses the vitality it had at first, until 
it becomes little better than idiotic. To prevent this 
* A young lady beginning to play the piano is obliged to fix her 
whole attention upon the position of her hands and upon the keys she 
is to strike. When training has given her skill, she strikes the keys cor- 
rectly without thinking, and she is able to give her whole attention to 
the music. In like manner, skill enables the workman to do his best 
work with the least conscious attention. 116 
HOW WE LIVE. 
result, the mind requires daily activity in careful 
study, or in directing some useful work.* 
Rest of the Nerves.—The nerves also need rest. 
Like the muscles, they become tired with exercise. 
Nightly sleep furnishes the necessary rest for proper 
daily exercise. If, during the day, the nerves are 
unduly exercised or strained, they become weary, 
and sleep does not restore their vigor. If the strain 
is continued, sleep is broken, the weariness in- 
creases, and the nervous system breaks down, leav- 
ing the person a helpless burden to others. Ex- 
cessive study, or excessive work of any kind, which 
requires brain-labor, often results in congestion or 
softening of the brain, or in paralysis. 
How Alcohol affects the Nerves.—Alcohol and 
other narcotics have a tendency to paralyze the 
nerves, and so diminish their power to act. This 
effect first shows itself in the nerves which con- 
trol the passage of the blood through the small 
arteries. The half-torpid nerves can not sufficiently 
control the rush of the blood, and the minute ves- 
sels are gorged. This gives to the skin a peculiar 
redness, which is very observable in the delicate 
skin of the face. The brain is affected in a similar 
manner, and is gorged with blood, causing great 
* The nerves are greatly affected by emotion. By a joyous and 
happy mood nervous action is increased, the vital organs are stimulated 
to do their work well, and a glow of health pervades the whole body. 
Grief diminishes nervous action. Sudden bad news sometimes so para- 
lyzes the nerves that the heart ceases for a time to beat, and faintness, 
or even death, is the result. 11l temper, envy, sulkiness, and all kinds 
of selfishness and meanness, diminish nerve-force, and tend to derange 
the action of the vital organs. HOW BODILY MOTION IS DIRECTED. 
activity and tumult, but not the orderly action 
which produces good thinking and leads to useful 
doing. 
If the alcohol is continued until the habit of 
drinking is formed, the derangement of the nerves 
becomes more marked. The heart is weakened and 
grows feeble in its action ; the nerves lose con- 
trol of the muscles and the limbs stagger; and there 
is a general derangement of all the organs, because 
the nerves which ought to produce harmony of 
action are paralyzed. 
Effect on the Mind.—The cerebrum is the seat 
of intelligence and of the moral nature. Through 
the cerebrum the mind directs and controls bodily 
action. The cerebellum is the seat of the nervous 
influence that more immediately affects the body, 
and it controls the regular order of unconscious 
action, like walking. Alcohol much more quickly 
paralyzes the cerebrum than the cerebellum. In 
consequence, when drink has been taken in excess- 
ive quantities, both the intelligence and the moral 
nature are dead for a time, and the appetites and 
passions have full sway. In this way a man is often 
converted into a brute, dangerous to his family, to 
his neighbors, and to himself. Continued drunken- 
ness often ends in delirium and death. 
How Tobacco affects the Nerves.—The general 
use of tobacco diminishes nervous action. Its ha- 
bitual use is not so destructive as that of alcohol, 
but still it is a substance which enters into the sys- 
tem without furnishing any needed element. It is 
in the body, but not of it. When used to excess, it 118 
HOW WE LIVE. 
has a particularly paralyzing- effect upon the nerves 
which control the muscles of the heart, weakening 
its action to such a degree as often to cause spasms 
and insensibility. 
Inheritance.—Children inherit from their par- 
ents nerves weakened by the use of alcohol and to- 
bacco, and the lives of thousands of innocent per- 
sons are thus made miserable. Usually the first 
drink and the first smoke are found to be very dis- 
agreeable, but quite often an inherited appetite 
shows itself, and the sweet breath of the child be- 
comes foul with the whisky and tobacco which can 
not be kept out of his way. Beginning with this 
unnatural appetite, habits are speedily formed which 
make his life a burden to himself and to others. 
Hygiene of the Nerves. 
As the nerves control all the movements of 
the body, both conscious and unconscious, and thus 
affect its nourishment, we need to take the greatest 
care to keep them healthy, and especially to avoid 
all courses likely to injure them. 
I. We must observe all the laws of digestion, so 
that the brain and the nerves may be supplied with 
pure blood. 
IT. We must avoid breathing foul air, or the 
nerves will be paralyzed by the impurities of the 
blood. 
111. To keep it in health, the brain should every 
day be brought into vigorous action by some form 
of study or thinking. 
IV. Active daily exercise, by either work or HOW BODILY MOTION IS DIRECTED. 
119 
play, is necessary to secure the healthful action of 
the nerves distributed through the body. 
V. We need a great variety of objects to ob- 
serve, to handle, and to study, in order that the 
sensory nerves may receive sufficient exercise. 
VI. We need a great variety of work, having the 
stimulus of a useful purpose, that the motor nerves 
and the brain may be excited to healthful action. 
VII. When we are tired we need rest, because 
as much nervous force as we can spare has been 
used up. Sleep, the natural rest from daily toil, 
should be regular, and should continue until the 
vigor of the nerves is restored. 
VIII. The hardest study and the closest think- 
ing should be done when the nerves are most vig- 
orous, and that is usually during the first half of 
the day. 
IX. We should never try to think or study 
when we are sleepy. In the first place, we then 
need sleep more than knowledge; and, in the sec- 
ond place, we gain very little knowledge when the 
mind is weary. 
X. We should avoid continued and excessive 
mental work, because it may become so exhausting 
as to break down the whole nervous system. 
XI. When the nerves have become so exhausted 
that we can not sleep, we must give up all labor 
and thinking until the nerves have recovered their 
lost strength. 
XII. Cramming for an examination is much 
more exhausting than a much longer period of 
regular study, and should be avoided. 120 
HOW WE LIVE. 
XIII. We should try to do those things which 
will form good habits, so that we may easily and 
certainly perform good deeds throughout life. 
XIY. We should take special pains to avoid 
doing anything which tends to form bad habits, 
because it will be always difficult, and sometimes 
impossible, to correct such habits when they have 
once been formed. 
Something to Find Out. 
i. In study, what should always be our object? 
2. In the study of science, what evils come from 
trying to learn the exact words of a text-book ? 
3. What is the effect of adding careful experi- 
ment to the study of a subject ? 
4. In case we do not understand a subject that 
we have studied, what is to be done ? 
5. Why is it injurious to attempt to hold the 
breath for any considerable time ? 
6. When we have eaten too much, what symp- 
toms, besides sickness at the stomach, may we ex- 
pect ? 
7. After we hs,ve learned to walk, what nervous 
action controls walking ? 
8. What trouble would come if the cerebrum 
were obliged to control walking? 
9. Why is it easier to perform an act the second 
time than at first ? 
10. What is the result of doing one act re- 
peatedly ? 
11. When we perform acts without much think- 
ing, what have we acquired ? HOW BODILY MOTION IS DIRECTED. 
121 
12. What kinds of acts lead to the formation of 
good habits ? of evil habits ? 
13. What does a person need in order to be- 
come a good base-ball player ? 
14. What term is applied to persons who do not 
like to exercise either body or mind ? 
15. What good do we get from play that we do 
not get from work ? 
16. What good results from work that does not 
come from play ? 
17. Why is night the best time for sleep ? 
18. What good comes from having sleep at regu- 
lar hours ? 
19. Why should we give up study when we are 
sleepy ? 
20. What kind of games are beneficial to stu- 
dents while attending school ? 
21. What kind of games would rather injure 
than benefit them ? 
22. Explain how a game may be beneficial to a 
farmer when it would injure a student. 
23. What class of people is most benefited by a 
week’s fishing in summer? 
24. What good comes from the use of alcohol 
when we are in health? From the use of tobacco? 
26. Why may a drunken man be considered in- 
sane ? 
25. How does alcohol affect speech? 
27. In what way can we best avoid the dangers 
and miseries which come from drunkenness? 
28. How may we escape from the danger of 
heart-trouble caused by tobacco ? 
6 CHAPTER X. 
HOW THE MIND GETS IDEAS AND EXPRESSES 
THEM. 
Sensations.—The sensory nerves receive im- 
pressions from objects and carry them to the brain. 
These impressions are called sensations. When the 
sensation is fully known to the mind, it is called an 
idea. Since the skin most directly comes in con- 
tact with objects, it has the greatest supply of sen- 
sory nerves. From nerves in the muscles we get 
ideas of pressure and weight. Through the nerves 
of touch in the skin we get from the surface of ob- 
jects the ideas which are expressed by the terms hard 
and soft, rough and smooth, hot and cold. 
But these ideas are not enough. The mind 
needs to know about flavors and odors ; it must get 
from sound its meaning and its music ; and from 
light it must learn the beauty of form and color. 
For these purposes some of the sensory nerves 
take the form of special nerves of sense, as those of 
taste, smell, hearing, and sight. 
The Sense of Taste, 
The Taste as a Sentinel.—Special care must be 
taken that improper food be not admitted into the HOW THE MIND GETS IDEAS. 
123 
stomach. The mind must keep close watch over 
all things eaten, and must reject such as will be 
likely to injure any part of the body. One of the 
agents which the mind uses to determine whether 
food is wholesome or unwholesome is the sense of 
taste. 
Flavors.—When food is taken into the mouth, 
it gives an impression which we call flavor.* The 
nerves upon which flavors make an impression give 
us the sense of taste, and are called gustatory nerves. 
They are distributed over the tongue and the back 
part of the mouth. Many substances taken in the 
mouth may be felt but not tasted. Touch takes 
notice of certain qualities of all substances; but 
taste notices flavors only, and is not aroused to 
activity until the surface of the substance yielding 
the flavor is dissolved by saliva. We can get no 
idea of flavor except through the gustatory 
nerves. 
Before flavors can be perceived, the substance 
must come in direct contact with the nerve. When 
a strong flavor has been tasted, the impression will 
remain for some time, and will prevent other flavors 
from making their proper impression. Except in 
disease, the flavor of most wholesome foods is pleas- 
* The primary and strongest flavors are sweetness, sourness, saltness, 
and bitterness. Besides these, there are the flavors peculiar to differ- 
ent fruits, such as peaches, grapes, etc., and the flavors peculiar to the 
different varieties of the same fruit, as that of Catawba and of Dela- 
ware grapes. It is thought by some that all possible flavors are made 
up of different combinations of the four primary ones; but this point is 
not settled. 124 
HOW WE LIVE. 
ant, and the necessary act of daily eating is thus ren- 
dered agreeable.* 
The Sense of Smell. 
Odors.—Another of the agents employed to test 
foods is the sense of smell. When certain sub- 
stances are brought near the nose, they make an 
impression which is called odor. The nerves upon 
which odors make an impression give us the sense 
of smell, and are called olfactory nerves.f These 
nerves are distributed through the cavities of the 
nostrils. Substances smelled do not come in con- 
tact with the olfactory nerve. Such substances 
give off something that we call aroma, or odor. In 
no way can we measure or weigh odor. It is only 
known through the sense of smell. Agreeable odors 
give us a sense of pleasure, and also stimulate the 
whole nervous system. 
* The sense of taste is not a perfect guide in the choice of foods. 
One of the conditions of good digestion is that food shall be palatable. 
But palatable food is not always wholesome, and the mind must have 
other means of deciding what shall be eaten. 
The act of eating is agreeable ; but, if we give ourselves up to the 
pleasures of the appetite, swine have an advantage over us, as they ap- 
pear to enjoy eating even better than we do. 
f The olfactory nerve notices nothing but odors. Unpleasant odors 
denote the presence of something hurtful. Food that is tainted, or that 
gives off an unpleasant odor, is unfit for the human stomach. Air that 
smells vile is unfit to breathe. A keen sense of smell is very desirable, 
and it will be well to always “ follow the nose ” when it leads away 
from bad odors. HOW THE MIND GETS IDEAS. 
The Sense of Hearing. 
Sound.—Whenever an object of any kind moves, 
a portion of the air is disturbed and set in motion. 
Whenever an object has a continued motion to and 
fro, a similar wave-like motion, or vibration, is set up 
in the air. These vibrations strike upon the ear, and 
produce an impression which is called sound* The 
nerves that receive impressions of sound are the 
auditory nerves, and the sense that has sound for its 
object is the sense of hearing. 
It is necessary that the mind should know what 
movements are going on around it, so that it may 
avoid danger, and take advantage of circumstances 
to carry out its purposes. It should be able to dis- 
tinguish different sounds for the pleasure that music 
affords. The mind must also be able to distinguish 
and produce the sounds used in articulate speech 
for the purpose of understanding and of expressing 
thought. These ends it accomplishes by means of 
the ear. 
The Ear.—The ear, which is the organ of hear- 
ing, has three parts : the outside or external ear, 
* The least number of vibrations that produce a sound which the 
ear can perceive is sixteen per second. As the vibrations increase in 
rapidity, the sound becomes higher in pitch. The highest sound that 
the ear perceives is made by about thirty-two thousand vibrations per 
second. Vibrations below sixteen and above thirty-two thousand per 
second are silent to the human ear. 
The sense of hearing may be cultivated so that the ear will detect 
sounds which are not audible to other ears, and will observe differences 
which were before unnoticed. This cultivation makes life richer by 
the new enjoyments which it affords. 126 
HOW WE LIVE. 
which we see ; the middle ear, or tympanum, which 
is a small passage through the bones ; and the in- 
Fig. 30.—The parts of the ear: a, external ear; 5, passage; c, membrane 
of the tympanum ; d—m, bones and their connections; n—r, interior 
canals and openings ; 1, 2, 3, small bones of the ear, highly magnified. 
ternal ear, which consists of several winding pas- 
sages in the bony structure of the skull. The three 
parts of the ear are separated by thin membranes 
which stretch across each end of the tympanum 
like the head of a drum. A passage, called the 
Eustachian tube, opens from the tympanum into the 
throat.* 
The vibrations of the air striking the outer mem- 
* Through the Eustachian tube, air is admitted to the inside of the 
tympanum, so that the pressure upon both sides of the “ ear-drum ” is 
equal. When we have a cold and the throat is swollen, the mouth of 
this tube is closed, and we become quite deaf for a time. The remedy 
is, not to doctor the ears, but to cure the throat. HOW THE MIND GETS IDEAS. 
brane of the tympanum cause it to vibrate, and the 
motion is conveyed to the auditory nerve, which is 
spread over the passages of the internal ear. This 
gives the impression of sound. The quality and in- 
tensity of the vibrations are in some measure regu- 
lated by a chain of minute bones within the tym- 
panum, and by the limpid fluid which fills all the 
passages of the internal ear. The auditory nerve 
notices nothing but sound. 
Care of the Bar.—The ear needs little care ex- 
cept to be kept clean; otherwise it should be let 
alone. The wax which lines the inner passage is 
bitter, and prevents insects from crawling in.* It 
should not be removed. In summer, boys, while in 
swimming, often get water into their ears. It fre- 
quently remains for a considerable time, and is very 
disagreeable. This difficulty may be prevented by 
stuffing a little cotton into the ears before going 
into the water. 
The Sense of Seeing. 
Light.—lt is now generally believed that light, 
as well as sound, is produced by vibrations. But 
while sound comes from vibrations of the air, light 
is the result of vibrations of a fluid much thinner 
than air, and which fills all the space between the 
earth, the sun, and the stars. These vibrations 
nake no impression upon any of the nerves of the 
* In spite of all care, an insect sometimes gets into the ear, where 
its movements sound exceedingly loud. When this happens, oil may 
be used to destroy the life of the intruder, and then the ear may be 
cleansed by means of a soft cloth. 128 
HOW WE LIVE. 
body except the optic nerve of the eye, and here it 
gives the impression which is called light.* 
Need of Light.—The mind needs to know the 
forms and positions of objects. The body, in travel- 
ing in search of food, must avoid the abrupt preci- 
pice, the dangerous pit, the deep water. It must 
have some sure guide to the things necessary to its 
existence. The mind must be able to judge of dis- 
tance for purposes of use and protection. It also 
has higher needs. For its own growth and happi- 
ness it must be able to see the beauty which color 
unfolds, and which is found in the shifting scenes of 
mountain and sea, and in the varying forms of ani- 
mal and vegetable life. All these come to the mind 
by means of light and through the eye. 
The Eye.—The eyes are spherical bodies about 
one inch in diameter, and are placed in bony sockets 
in the front part of the skull. On all sides, except 
the front, they are protected by strong bones and 
cushions of soft tissue. The eyelids, with rows of 
eyelashes along their edges, can close over the front 
of the eyes, so as to protect them from dust and in- 
sects. The eyebrows turn the sweat on the fore- 
head away from the eyes. Tears keep the eyes moist, 
and winking spreads the tears over their surface.f 
* By means of a prism it is shown that light is composed of many 
colors. Differences in color are supposed to come from difference in 
the rapidity of the vibrations which produce light. 
f A tube connects the tear-gland with the nose, so that extra tears 
usually flow through it. In case of great grief, or anger, the tears 
overflow, and this excess of tears is called weeping. Sometimes the 
tube leading to the nose gets obstructed, producing what is termed a 
“ weeping eye.” HOW THE MIND GETS IDEAS. 
129 
Structure.—The eye has three coats. The scle- 
rotic coat, on the outside, is strong and tough. It 
serves to keep the eye in shape, and also as a place 
Fig. 31.—Horizontal section of the eyeball: Scl, sclerotic coat; Cn, cornea; 
Ch, choroid; Ir, iris; Aqy aqueous humor; Cry, crystalline lens ; 
Vt, vitreous humor; Rt, retina ; Op, optic nerve. 
of attachment for muscles. This coat has an open- 
ing in front, in which a convex transparent mem- 
brane called the cornea is placed, very much as a 
crystal is inserted in a watch. Next, inside, is the 
choroid coat, made of softer tissue, and containing 
the blood-vessels that supply the eye. The interior 
part of this coat is black or very dark-colored.* 
The retina, or inside coat, is formed by the spread- 
* The dark interior surface of the choroid coat absorbs the light 
which is not needed for clearness of seeing. When this black coloring- 
matter is wanting, as in the case of albinos, vision is defective. 130 
HOW WE LIVE. 
ing out of the optic nerve over the back part of 
the eye. 
The crystalline lens is a transparent body, shaped 
like a convex eye-glass, only much thicker in the 
middle. It lies near the front of the eye, encircled 
by the sclerotic coat. The space back of the crys- 
talline lens is filled with a transparent, jelly-like 
substance called the vitreous humor; and the space 
between the crystalline lens and the cornea is filled 
with a watery fluid called the aqueous humor. In 
front of the crystalline lens is a colored curtain 
called the iris. Through the iris is an opening 
called the pupil, through which light is admitted. 
The muscles of the iris are so constructed that in 
a dim light they enlarge the pupil so as to admit 
more light, and in strong light they diminish the 
pupil so that some of the light is shut out,* 
Muscles of the Eye.—Muscles in the interior of 
the eye change the form and position of the crys- 
talline lens, and enlarge and diminish the iris for 
the purpose of adjusting the light. The motion of 
the whole eye is controlled by four straight mus- 
cles which move it up and down, and from right 
to left. Besides these, one muscle goes through a 
pulley, and rolls the eye around in its socket.f 
* The effect of light upon the iris may be seen by observing the 
eyes of a cat. In a strong light the pupil closes so nearly that it ap- 
pears only as a faint line. In a dim light the pupil enlarges so much 
that the iris nearly disappears. 
f When the interior muscles are too strong, the eyes are turned 
toward the nose, producing internal strabismus, or “ cross-eyes.” When 
the exterior muscles are too strong, exterior strabistnus results. These 
difficulties can be easily remedied by a skillful surgeon. HOW THE MIND GETS IDEAS. 
131 
Action of Light. The light enters the eye 
through the cornea, and passes through the aque- 
ous humor. The iris here steps in and shuts off all 
light not needed. The crystalline lens next receives 
the light that the iris permits to pass, and so adjusts 
itself that the light falls upon the retina in just the 
way to make the right impression of form. When 
vision is perfect, an exact image of the object seen 
is made upon the retina.* 
Care of the Eye.—The crystalline lens is some- 
times too convex, producing short-sightedness. 
This trouble calls for the use of concave glasses. 
As old age comes on, the crystalline lens becomes 
flattened, and convex glasses are needed. When 
we read or study, the light should be thrown upon 
the book or object, and not into the eyes. A glare 
of light in the eyes makes objects appear dim. On 
the other hand, we should avoid trying to read or 
see small objects in a dim light. If the strain which 
such a practice occasions is continued, it is liable to 
weaken the eyes and produce temporary or per- 
manent blindness. Cross-lights, or lights coming 
into a room at different angles, are hurtful to the 
eye. As these lights are of different intensity, the 
muscles of the iris become weary of trying prop- 
erly to adjust the ever-changing light. 
* Get from the butcher the eye of an ox; carefully cut away the 
sclerotic coat on the back side ; then darken a room, except one ray of 
light. In this opening place the eye, as though looking out. On the 
retina can then be seen a distinct image of objects outside, but they 
appear upside down. From the same eye may be obtained an idea of 
'die brilliancy and transparency of the vitreous humor. 132 
HOW WE LIVE. 
The mind has need to express thought as well 
as to receive it. It needs not only to learn from 
the experience of others, but also to give to others 
the result of its own experience. The most effect- 
ive means by which this interchange of ideas is 
brought about is the voice as heard in speech. Cer- 
tain combinations of sounds are called words, and 
words express ideas. 
The Organs of Speech. 
The Voice. The larynx is the prominence 
which lies immediately above the trachea. The 
triangular opening from the mouth into the larynx 
is called the glottis. Along each side of the glottis 
are thin membranes called vocal cords. These mem- 
branes usually hang loose, but they can be stretched 
and made to vibrate. They then produce sound in 
much the same way as it is produced by the vibrat- 
ing strings of a musical instrument. This sound is 
the voice. 
Speech.—The sounds of the voice will be higher 
or lower as the vocal cords are more or less tight- 
ened, and so vibrate faster or slower. By slight 
changes in the opening of the glottis the sound can 
also be made to vary in quality and quantity. The 
voice, coming out through the mouth, is shaped into 
articulate speech by the teeth, tongue, palate, roof 
of mouth, and lips, under the direction of the mind.* 
* Speech is chiefly a matter of imitation. Children who are accus- 
tomed to hear correct speech will usually speak correctly. During the 
first three or four years of school-life, distinctness of speech may be pro- 
moted by giving rather more than the usual prominence to the syllables HOW THE MIND EXPRESSES IDEAS. 
133 
Care of the Voice.—Scarcely anything is more 
to be desired than a pleasant voice. The possessor 
of such a voice is sure to be heard when no heed is 
given to others, and his presence gives pleasure 
where that ol others would give pain. To secure 
the possession of these pleasant tones, care must be 
taken not to put too great a strain upon the vocal 
cords in youth. Screaming, loud wrangling, bois- 
terous singing, and hallooing, all have a tendency to 
break or harden the vocal cords, so that afterward 
they can make none but coarse and harsh tones. 
Care must also be taken not to use the vocal cords 
much when the throat is sore from any cause. 
Hygiene of the Organs of Special Sense. 
I. When things taste bad, we should examine 
them with great care, and know that they are not 
harmful before we eat them. 
11. We should be careful not to injure the sense 
ol taste by the use of tobacco and other pungent 
substances. 
111. Things that smell bad should be avoided. 
IV. It is well to refresh ourselves and to stimu- 
late our nerves by a very moderate use of perfumery. 
V. Keep all hard instruments out of the ear-pas- 
sages. 
VI, Do not sit facing the light. 
VII. Do not use the eyes much in a dim light. 
VIII. Do not try to study or look closely with 
cross-lights or other uncertain and varying lights. 
of words. Later the same object may be gained by short daily drills 
upon the vocal elements of the language. 134 
HOW WE LIVE. 
IX. Do not attempt to see much when the eyes 
give notice of exhaustion by sleepiness or pain. 
X. Do not strain the vocal cords by continued 
loud and high tones in singing or in speech. 
XI. Use the voice gently at the period when it 
is “ changing,” and always when there is any in- 
flammation of the throat. 
Something to Find Out. 
1. What part of the skin is best supplied with 
sensory nerves, and is thereiore the most sensitive ? 
3. Why does a piece of marble feel cooler than 
a piece of fur that lies by its side ? 
2. What can we find out by the sense of touch ? 
4. Does it ever happen that the marble feels 
warmer than the fur under the same conditions ? 
5. Why can we not taste a piece of marble ? 
6. How can we tell the flavor of a fruit that we 
have heard described but have never seen ? 
7. What old fable shows the folly of deciding 
upon the flavor of grapes that grow out of reach? 
8. Why can we not relish the flavor of a peach 
just after taking quinine ? 
9. What difference does the gustatory nerve per- 
ceive between the surface of a piece of iron and that 
of a piece of soft, cotton cloth ? 
10. Why should we take considerable time for 
each of our meals ? 
11. Why should we not usually spend several 
hours at a meal ? 
12. Why are roses and lilacs so frequently plant- 
ed about houses ? HOW THE MIND GETS IDEAS. 
135 
13. What would be the effect, if fragrant flowers 
could be planted around all homes ? 
14. Why should we object to having a tannery 
or a slaughter-house put up near our dwelling ? 
15. In what way can we turn to profitable ac- 
count the decaying vegetable and animal substances 
which give off bad odors ? 
16. Why should we cultivate a liking for pleas- 
ant odors, and learn to discriminate between 
them ? 
17. What animals are noted for keenness of scent ? 
Of what use is this sense to them ? 
18. What are some of the disadvantages of being 
deaf ? 
19. What pleasures of a high character do we 
get through the ear ? 
20. What special charms has an early morning 
walk in the country in summer ? 
21. When near by, why is the shrill whistle of a 
locomotive or the clang of a gong disagreeable ? 
22. Read from Goldsmith’s “ Deserted Village” 
the description of summer evening sounds. What 
sounds are described, and why do they all make so 
pleasant an impression ? 
23. What advantage has the cultivated musician 
over one who has no taste for music ? 
24. What difference in shape do you notice be- 
tween the pupil of a cat’s eye and that of your 
own ? 
25. What differences do you notice in the iris of 
the eyes of different persons ? 
26. What in other parts of the body corresponds 136 
HOW WE LIVE. 
to the coloring of the iris, and the black coloring- 
matter of the interior of the eye ? 
27. What is the color of the eyes of an albino, 
and why is his sight defective ? 
28. What are some of the useful ideas which we 
get through the eye ? 
29. What pleasurable emotions come from trav- 
eling among the mountains ? 
30. What from observing the sea ? What from 
a walk in the garden ? 
31. How does voice differ from speech ? 
32. What are some of the disadvantages of a 
harsh voice ? 
33. What does a pleasant voice indicate ? 
34. Why should not little children be permitted 
to sing “ at the top of their voices ” ? 
35. What advantage comes from always hearing 
clear and pleasant tones in speech ? CHAPTER XL 
STIMULANTS AND NARCOTICS. 
i. Stimulants. 
Unnecessary.—Continuous exercise without in- 
termission is impossible. Even the heart, which 
seems always busy, rests more than it works. It re- 
poses and feeds between its beats. Its resting spells 
are short, but they come often. They occupy three 
fifths of the time, so that in twenty-five hours the 
heart works but ten and reposes fifteen. 
When muscular or mental exercise is too violent 
or prolonged, fatigue is felt. The w'aste of muscu- 
lar or brain substance is greater than the repair. 
Food and rest relieve the fatigue. 
The repairing materials are supplied by the 
food ; they are used during rest. 
The food should be sufficient but not excessive 
in quantity ; nutritious, easily digestible, and varied 
in quality. The time devoted to eating and repose 
should be ample. It should not be stinted nor be- 
grudged as if it were misspent. 
When the various parts of the body are in a 
healthy condition, only food and rest are required 
to enable them to exercise their functions to the best 
advantage. 138 
HOW WE LIVE. 
In disease there may be emergencies when stimu- 
lants are useful and necessary. Like the helping 
hand extended to an exhausted swimmer, they may 
save from fatal sinking. Like the whip which is 
vigorously applied to the overtasked and straining 
street-car horses, when they falter near the summit 
of the hill, stimulants may impart an artificial 
strength which shall be sufficient to overcome the 
difficulty. But stimulants are goads. They do not 
nourish. They add nothing to the material from 
which permanent strength is derived. In health 
they are useless. The horse which can do its cus- 
tomary work only while under the constant appli- 
cation of the lash is really disabled by laziness or 
disease. And the person who resorts to alcoholic 
stimulants because he thinks that without their fre- 
quent goading he can not perform the drudgeries, 
or even the ordinary duties of life, is in a pitiable 
condition. If he be in health he is mistaken. 
Observation proves that, in the long run, more 
and better mental and physical work can be done; 
hunger, fatigue, and long exposure to extreme cold 
or heat better endured ; and that the average health 
approaches more nearly a perfect standard without 
than with the habitual use of stimulants. 
Injurious.—But stimulants are injurious. Like 
the too powerful mainspring in a delicate watch, 
they produce strong and violent manifestations, but 
they wear out the works. 
The tendency of alcoholic stimulants—and these 
are the only ones now under consideration—is to 
impair the normal action of the various parts of the STIMULANTS AND NARCOTICS. 
139 
body, and even to produce serious organic disease. 
How this is accomplished is explained in various 
parts of this book. 
One of the saddest results of the use of these 
stimulants is a diseased craving, which can be satis- 
fied only by the further use of that which caused 
the craving and which intensifies it. 
Daily observation and abundant testimony prove 
that this acquired appetite may, and in numberless 
instances does, become almost irresistible, requiring 
increasing potations to appease its insatiable de- 
mands, and dragging down its helpless victims, 
through disease and loss of self-respect and blunted 
moral perceptions, and even crime, to utter ruin. 
If alcoholic stimulants are unnecessary, injuri- 
ous, and dangerous, should they not be avoided ? 
Is not the path of safety the path of wisdom ?* 
2. Narcotics. 
These are substances which first exhilarate and 
then induce drowsiness or stupor. There are many 
of them, but two only will be noticed here: opium 
and tobacco. 
* As showing how the habit of using alcoholic beverages dimin- 
ishes the likelihood of recovery from serious illness, the following 
statement is of great value. It is from the report of the Investigation 
Committee appointed by the British Medical Association. The re- 
port was published in July, 1884. 
In 1,065 cases of pneumonia there were 192 deaths. 
The mortality of the temperate was 17 per cent. ; of the intemper- 
ate, nearly 43 percent.; while of the total abstainers it was but 10 
per cent. 140 
HOW WE LIVE. 
The consumption of opium and its various prep- 
arations has greatly increased within a few years. 
While its continuous use does not seem to shorten 
materially the life of its devotees, it renders it 
miserable. It enfeebles the intellect, enervates the 
bodily powers, gives a dull and vacant appearance 
to the face, and so perverts the moral sense that 
habitual opium-eaters are habitual liars. From its 
firm grasp its victims seldom escape. Their brief 
struggles for release become more and more im- 
potent, till finally the captivity is accepted as hope- 
less. Opium should be taken only when adminis- 
tered by a wise and prudent physician. 
Tobacco affects primarily the nervous system. 
It stimulates and it soothes. It seems to furnish 
great pleasure to those who chew or smoke it. But 
it has its drawbacks. Its habitual use impairs di- 
gestion, often causes palpitation of the heart, trem- 
bling of the hands, disturbance of the delicate 
bronchial tissue, and sometimes permanent injury 
of the nerves. 
Chewing is specially filthy. Smoking is offen- 
sive to a large proportion of the best people. 
Those who have abandoned the use of tobacco 
declare that they have sweeter breath, cleaner 
tongues, better digestion, steadier nerves, increased 
power of endurance, and a higher average of enjoy- 
ment ; and that the loss of the fascinating excite- 
ment is more than offset by freedom from the result- 
ing depression. 
Should not a practice, however popular, which is 
filthy, offensive, hurtful, and expensive, be avoided ? WHAT THE WORDS MEAN. 
Ab-do'men (Latin, abdo, to hide). The largest cavity of the body, 
situated beneath the level of the diaphragm, and containing the 
liver, stomach, intestines, etc. ; the belly. 
Ab -sor'bents (Latin, ab and sorbeo, to suck up). The vessels which 
take part in the process of absorption. 
Ab-sorp'tion. The process of sucking up fluids by means of an 
animal membrane. 
Ac'id (Latin, acidus, from ace re, to be sour). A substance usually sour, 
sharp, or biting to the taste. 
Ad'am’s Ap'ple. An angular projection of cartilage in the front of 
the neck. It is particularly prominent in males, and is so called 
from a notion that it was caused by the apple sticking in the throat 
of our first parent. 
Al-bi'no (Italian, albino, whitish). A person having a peculiar white- 
ness of the skin and hair, and a redness of the iris and pupil of the 
eye. 
Al-bu'men (Latin, albus, white). An organic substance resembling 
white of egg. 
Al-bu'mi-noids (Latin, albumen, and Greek, eidos, form). A class 
of substances resembling albumen ; they may be derived from either 
the animal or the vegetable kingdom. 
Al'co-hol (Arabic, al kohl, a powder to paint the eyebrows with). The 
Al-i-ment'a-ry Ca-nal' (Latin, alimentarius, from alo, to nourish). A 
long tube, of varying form and size in its different parts, in which 
the digestion of the food, or “ aliment,” is performed. It com- 
prises the mouth, the pharynx, the esophagus, the stomach, and the 
small and large intestine. 
intoxicating element of spirituous liquors. WHAT THE WORDS MEAN. 
142 
Al'ka-Ii (Arabic, al kali, the soda-plant). A name given to certain 
substances, such as soda, potash, and the like, which have the power 
of combining with acids to form salts. 
A-nat'o-my (Greek, anatome, cutting up, dissection). The study of 
the different parts and the structure of the body. 
Am'y-loid (Greek, amulon, fine meal, and eiaos, form). A substance 
similar to amyle, which is composed of ten parts of carbon and 
eleven of hydrogen. 
A-or'ta (Greek, aorteomai, to be lifted up). The largest artery of the 
body, and main trunk of all the arteries. It arises from the left 
ventricle of the heart. The name was first applied to the two large 
branches of the trachea, which appear to be lifted up by the heart. 
Ap-pend'age (Latin, ad, to, and pendeo, to hang). Something added 
to a principal or greater thing. 
A'que-ous Humor (Latin, aqua, water). A few drops of watery, 
colorless fluid occupying the space between the cornea and crystal- 
line lens. 
A-ro'ma (Latin). The agreeable odor of plants or other substances. 
Ar-te'ri-al Blood. The bright-red blood in the left side of the heart 
and the arteries of the general circulation. 
Ar ter-y (Greek, aer, air, and tereo, to keep). A vessel conveying the 
blood from the heart outward to the organs ; so called because the 
ancients thought these vessels contained air. 
Ar-tic-u-la'tion (Latin, articulo, to form a joint). The movable 
union of bones ; a joint. 
Ath-let'ic (Greek, athleo, to contend for a prize). Belonging to 
wrestling, boxing, running, and other manly exercises and sports. 
Au'di-to-ry Nerve (Latin, audio, to hear). The special nerve of the 
sense of hearing. 
Au'ri-cle (Latin, auricula, the outer ear). The smaller and thinner 
chamber of the heart on each side, which receives the blood directly 
from the veins ; so called from a fancied resemblance in shape to a 
dog’s ear. 
Au-to-mat'ic (Greek, automates, self-moving). Self-acting ; not de- 
pending on the will. 
Bi'ceps (Latin). A muscle situated upon the front part of the arm 
above the elbow, which serves to bend the elbow-joint. 
Bi -cus'pid (Latin, bi, two, and cuspis, prominence). The name of 
the fourth and fifth teeth on each side of the jaw ; possessing two 
prominences. WHAT THE WORDS MEAN. 
143 
Bile. The gall, or peculiar secretion of the liver ; a sticky, yellowish 
fluid, and very bitter to the taste. 
Blonde. Of a fair, or light, color or complexion. 
Bone. A firm, hard substance, of a white or pale-rose color, compos- 
ing the skeleton or firmer part of the body. 
Brain. The mass of nervous substance contained in the cavity of the 
skull. 
Bron'chi (Greek, bronchos, the windpipe). The two larger branches 
into which the trachea is divided, and into which the bronchial tubes 
open. 
Bron'chi-al Tubes. The smaller branches of the trachea within the 
substance of the Lungs, ending in the air-cells. 
Bru-nette'. Of a brown or dark color or complexion. 
Ca-lis-then'ics (Greek, halos, beautiful, and sthenos, strength). The 
practice of healthful exercise of the body and limbs, to give strength 
and grace of movement. 
Callus (Latin, calleo, to be thick-skinned). Any excessive hardness of 
the skin, caused by friction or pressure. 
Ca-nal’ (Latin, canna, a pipe). In the body, any tube or passage. 
Ca-nine' Teeth (Latin, canis, a dog). The pointed teeth situated just 
outside the incisors, one on each side in each jaw ; so called because 
they are very prominent in the dog, as well as in other flesh-eating 
animals. 
Cap'il-la-ries (Latin, capillus, hair). The smallest blood-vessels, be- 
tween the arteries and the veins ; so called from their minute or 
hair-like size. 
Car-bon'ic Ac'id (Latin, carbo, coal). The gas which is present in 
the air expelled from the lungs ; a waste product of the animal 
kingdom, and a food of the vegetable kingdom. 
Car'di-a (Greek, kardia, heart). The upper opening of the stomach, 
through which the food enters from the esophagus; so called be- 
cause it is situated near the heart. 
Car'di-ac. Pertaining to the heart or to the cardia 
CarTi-on (Latin, caro, flesh). The dead and decaying bodies of animals. 
Car'ti-lage (Latin, cartilagd). A firm, elastic substance, like India- 
rubber,, attached to the bones in various parts of the body, forming 
a part of the joints, air-passages, nostrils, and ear. 
Cav'i-ty (Latin, cavus, hollow). A hollow, inclosed space. 
Ca'se-ine (Latin, caseus, cheese). The albuminoid substance of milk, 
forming the basis of cheese. 144 
WHAT THE WORDS MEAN. 
Cer-e-bel'lum (Latin, diminutive of cerebrum, brain). The little 
brain, situated at the back and lower part of the head. 
Cer'e-brum (Latin). The brain proper, occupying the entire upper 
portion of the skull. It is nearly divided into two equal parts, 
called hemispheres, by a cleft extending backward from the front 
part of the head. 
Chest. The upper part of the trunk of the body, inclosed by the 
spinal column behind, the ribs on the sides, and the breast-bone in 
front. 
Cho'roid (Greek, chorion, skin, and eidos, like). A brownish-black 
membrane forming the middle coat of the eye-ball. 
Chyle (Greek, chulos, juice). Chyme changed in the duodenum, and 
turned white by the emulsion of fats. 
Chyme (Greek, chumos, juice). The pulpy liquid formed by digestion 
within the stomach. 
Cir-cu-la'tion (Latin, circulus, a ring). The circuit or course of the 
blood through the blood-vessels of the body, from the heart to the 
arteries, through the capillaries into the veins, and from the veins 
back to the heart. 
Clav'i-cle (Latin, clavis, a key). A slender bone, shaped somewhat 
like a key, placed horizontally at the bottom of the neck, between 
the top of the breast-bone and the point of the shoulder. The 
collar-bone. 
Col'lar-Bone. The clavicle. 
Con'cave (Latin, concavus, hollow). Curved or rounded, like the in- 
side surface of a hollow globe. 
Con-ges'tion (Latin, con, together, and gero, to bring). An unnatural 
gathering of blood in any part of the body. 
Con-nect'ive Tis'sue. A tissue consisting of loose fibrous bundles, 
which is placed between the muscles and other parts. 
Con-sump'tion (Latin, consume, to take entirely). A disease of the 
lungs, attended with a fever and cough, and causing a gradual de- 
cay of the bodily powers. 
Con-trac'tion (Latin, con, together, and traho, to draw). The active 
shortening of a muscle or muscular fiber. 
Con'vex (Latin, conveho, to bring together). Curved or rounded, like 
the outside of a globe. 
Con-vo-lu'tions (Latin, convolve, to roll together). The foldings of 
the external surface of the brain. 
Cor'ne-a (Latin, cornu, a horn). The transparent, horn-like substance WHAT THE WORDS MEAN. 
145 
which covers the front part of the eyeball, through which the light 
passes. 
Crystal-line Lens (Latin, aystallum, ice). A transparent, circular 
body, rounded on its front and back surfaces, situated in the eye- 
ball, just behind the pupil. 
Cus'pid (Latin, cuspis, a point). A pointed tooth next back of the 
incisors. 
Cu'ti-cle (Latin, diminutive of cutis, the skin). The scarf-skin ; also 
called the epidermis. 
Cu'tis Ve'ra (Latin). The true skin, lying beneath the cuticle ; also 
called the derma. 
Da.n'druff. The small scales, or particles, which separate from the 
scarf-skin of the scalp. 
De-lir'i-um (Latin). A state in which the ideas of a person are wild, 
irregular, and unconnected. 
Den'tine (Latin, dens, a tooth). The bony or ivory-like part of the 
teeth, lying directly beneath the enamel. 
Der'ma (Greek, the skin). The soft, moist, and thick underlying 
layer of the skin ; the true skin, or cutis vera. 
Di'a-phragm (Greek, diaphragma, a partition). The muscular sheet 
which separates the cavity of the chest from that of the abdomen. 
Di-ges'tion (Latin, di, apart, and gero, to bear). The preparation of 
the food in the alimentary canal. 
Dig'i-ti-grade (Latin, digitus, finger, and gradi, to walk). An animal 
that walks or steps on its toes. 
Dis-ease'. An unhealthy condition of some part of the body. 
Duct (Latin, duco, to lead). A narrow tube, usually designed to con- 
vey away a secretion from the gland in which it is produced. 
Du-p-de'num (Latin, duodeni, twelve each). The first division of the 
small intestines, about twelve finger-breadths long. 
E-las-tic'i-ty. The property of bodies by which they recover their 
former figure or size after the removal of outside pressure or 
force. 
En-am'el. The dense material which covers the crown of the tooth. 
Ep-i-der'mis (Greek, epi, upon, and derma, skin). The outer layer of 
the skin ; the scarf-skin, or cuticle. 
Ep-i-gl°t'tis (Greek, epi, upon, and glottis'). A leaf-shaped piece of 
cartilage which covers the top of the larynx during the act of swal- 
lowing. 
E-soph'a-gus (Greek, oiso, to carry, and phago, to eat). The tube 146 
WHAT THE WORDS MEAN. 
leading from the throat to the stomach, through which the food 
and drink pass in eating. 
Ex-cre'tion (Latin, excerno, to purge out). The process by which the 
waste materials of the body are removed ; also the materials ex- 
creted. 
Ex'er-cise (Latin, excrceo, to keep busy). Effort or action of the body 
for the sake of training, or of keeping its organs and functions in a 
healthy state. 
Ex-pan'sion (Latin, ex, out of, and panda, to open). The act of ex- 
tending or spreading out. 
Ex-pi-ra'tion (Latin, expiro, to breathe out). The act of forcing air 
out of the lungs. 
Ex-ten'sor (Latin, ex, out, and tendo, to stretch). A muscle which 
serves to straighten or extend a joint. 
Eu-sta'chi-an Tube. A membranous canal, extending from the fore 
part of the tympanum of the ear to the side of the pharynx ; from 
Eustachi, an Italian anatomist. 
Fe'mur (Latin). The thigh-bone. 
Fi'ber (Latin, fibra, a thread). One of the string-like portions which 
constitute a part of the tissues of plants and animals. 
Fi'bril (diminutive of fiber). A very small branch of a fiber. 
Fi'brine (Latin, fibra, a fiber). An animal matter found in the blood; 
so called because, when clotted, it has a fibrous texture. 
Fib'u-la (Latin, that which serves to fasten two things together). The 
outer and smaller bone of the leg. 
Flex'or (Latin, fiecto, fiexum, to bend). A muscle which serves to 
bend a limb or joint. 
Flip'per. The broad fin of a fish. 
Forii-cle (Latin, diminutive of follis, a bag). A little pouch or de- 
pression in a membrane ; it has generally a secretory function. 
Func'tion (Latin, fungor, functus, to perform). The office performed 
by any organ of the body. 
Gan'gli-on (Greek, ganglion, a knot). A knot-like swelling in the 
course of a nerve ; a smaller nerve-center. 
Gas'tric (Greek, gaster, the stomach). Pertaining to the stomach. 
Gel'a-tine (Latin, gelo, to congeal). An animal substance which dis- 
solves in hot water, and forms a jelly on cooling. 
Gland (Latin, glans, an acorn). An organ consisting of follicles and 
ducts, with numerous blood-vessels ; it separates some particular 
fluid from the blood. WHAT THE WORDS MEAN. 
Glot'tis (Greek, glotta, the tongue). The narrow opening between 
the vocal cords in the upper part of the larynx, by which it com- 
municates with the throat. 
Giu'ten (Latin). Literally, glue ; the gluey, albuminous matter of 
wheat-flour. 
Gus'ta-to-ry Nerve (Latin, gusto, to taste). The nerve of taste sup- 
plying the front part of the tongue. 
Gym-nas'tics (Greek, gumnazo, to exercise). The practice of athletic 
exercises. 
Hiccough. A spasm of some of the muscles used in breathing, accom- 
panied by a shutting of the glottis and a sudden sound. 
Hu' me-rus (Latin). The large bone of the arm between the shoulder 
and the elbow. 
Hu'mor (Latin). Moisture : the humors are transparent contents of 
the eyeball. 
Hy'gi-ene (Greek, huygieia, health). The art of preserving health 
and preventing disease. 
I-de'a (Greek, outward appearance). The complete conception of an 
object. 
In-ci'sor (Latin, incido, to cut). Applied to the four front teeth of 
both jaws, which have sharp, cutting edges. 
In-den-ta'tion (Latin, in, and dens, a tooth). A notch in the margin 
of anything. 
In-fe'ri-or Ve'na Ca'va (Latin, lower hollow vein). The chief vein 
of the lower part of the body. 
In-flam-ma'tion (Latin, prefix in, and flammo, to flame). A peculiar 
diseased condition of any part of an animal body. 
In-gre'di-ent (Latin, ingredi, to go into). That which enters into a 
compound as one of its constituents. 
In spi-ra'tion (Latin, in, and spiro, spiratum, to breathe). The act 
of drawing in the breath. 
In-ter-cos'tal Mus'cles (Latin, inter, between, and costa, a rib). 
The muscles which are situated between the ribs, and which move 
the ribs in respiration. 
In-tes'ti-nal Juice. A sticky secretion produced by the lining mem- 
brane of the small intestine. 
In-tes'tine (Latin, intus, within). The part of the alimentary canal 
which is continuous with the lower end of the stomach ; also called 
the bowels. 
I'ris (Latin, iris, the rainbow). The thin muscular ring which lies be- 148 
WHAT THE WORDS MEAN. 
tween the cornea and crystalline lens, and which gives the eye its 
brown, blue, or other color. 
Jaun'dice (French, jaune, yellow). A disease in which the skin as- 
sumes a yellowish color, supposed to be caused by an excess of 
bile. 
Lac'te-als (Latin, lac, lactis, milk). The absorbent vessels of the 
small intestines ; during digestion they are filled with chyle, which 
has a milky appearance. 
Lar'ynx (Greek). The box of cartilage situated at the top of the 
windpipe, through which the air passes from the throat into the 
trachea ; the organ of the voice. 
Lens (Latin). Literally, a lentil; a piece of transparent glass or 
other substance so shaped as either to bring together or disperse 
the rays of light. 
Lig'a-ment (Latin, ligo, to bind). A fibrous band or cord, serving to 
attach two bones to one another. 
Liv'er. The largest gland in the body, reddish in color, situated 
mainly on the right side, below the diaphragm. From the venous 
blood passing through it, it secretes bile. The liver produces from 
the blood an animal starch. 
Lobe. A round, projecting part of an organ, as of the liver, lungs, or 
brain. 
Loin. That part of an animal just above the hip-bone. 
Lu'bri-cate. To make smooth or slippery. 
Lung. One of the two organs of respiration in an air-breathing 
animal. 
Lymph (Latin, lympha, spring-water). The colorless, watery fluid 
conveyed by the lymphatic vessels. 
Lym-phat'ic Vessels. A set of very thin, delicate vessels, which 
absorb the lymph from the tissues of the body, and convey it in- 
ward toward the center of the venous system. 
Mac-a-ro'ni (Greek, makar, blessed). An article of food, composed 
chiefly of wheat-flour made into long, slender tubes, and much used 
in Italy. 
Mar'row. The soft, fatty substance contained in the central cavities 
of the bones ; the spinal marrow, however, is composed of nervous 
tissue. 
Mas'se-ter (Greek, massaomai, to chew). A strong muscle situated 
upon the side of the face, which moves the lower jaw from below 
upward in chewing. WHAT THE WORDS MEAN. 
149 
Mas-tl-ca'tion (Latin, mastico, to chew). The act of cutting and 
grinding the food to pieces by means of the teeth. 
Me-dul'la Ob-lon-ga'ta (Latin). The “oblong marrow,” or nerv- 
ous cord, which is continuous with the spinal cord within the 
skull. 
Mem brane (Latin, membrum, a limb or member). A thin layer of 
tissue serving to cover some part of the body. 
Mi'cro-scope (Greek, mikros, small, and skopeo, to look at). An op- 
tical instrument which magnifies objects. 
Mo lar (Latin, mola, a mill). The name applied to the three back 
teeth of each side of the jaw, which are adapted for grinding the 
food, like millstones. 
Mo'tor (Latin, moveo, motum, to move). Causing motion ; the name 
of those nerves which conduct to the muscles the stimulus which 
causes them to contract. 
Mu' cous Mem'brane. The thin layer of tissue which covers those 
internal cavities or passages which communicate with the external 
air. 
Mu'cus (Latin). The sticky fluid which is secreted by mucous mem- 
branes, and which serves to keep them in a moist condition. 
Mu-ri-at'ic Ac'id. An acid consisting of one part of hydrogen and 
one of chlorine. 
Mus'cles (Latin, musculus, a little mouse). A band of fibers acting 
as an organ of motion in animal bodies. The voluntary muscles 
act in obedience to the will, and contract suddenly ; the involun- 
tary muscles do not obey the will, and contract slowly. 
Nar-cot'ic (Greek, narkao, to benumb). A medicine which, in poi- 
sonous doses, produces stupor, convulsions, and sometimes death. 
Na'sal (Latin, nasus, the nose). Pertaining to the nose ; the nasal 
cavities contain the special nerve of smell. 
Nerve (Greek, neuron, a cord or string). A glistening, white cord, 
shaped like a tube, and connecting the brain or spinal cord with 
some other organ of the body. The nerves are the telegraph-wires 
of the body. 
Nerve-Fi'ber. A very slender thread of nervous tissue found in the 
nerves ; it is of a white color. 
Nos'tril (Anglo-Saxon, nosu, nose, and thyrl, a hole). One of the 
two outer openings of the nose. 
Nurt'ure. To train up with care; the food and attention necessary 
to such training. WHAT THE WORDS MEAN. 
Nu-tri'tion (Latin, nutria, to nourish). The processes by which the 
nourishment of the body is accomplished. 
01-fac'to-ry (Latin, olfacio, to smell). Pertaining to the sense of 
smell. 
Op'tic (Greek, opto, to see). Pertaining to the sense of sight. 
Or'gan (Greek, organon, an instrument). Any part of the body which 
is adapted to perform a particular service, such as the heart, the 
stomach, the brain. 
Ox y-gen (Greek, oxus, sharp, and genein, to bring forth). A gas 
forming one fifth part, by bulk, of the atmosphere, and essential to 
respiration. 
Pal'ate (Latin, palatui7t, the palate). The roof of the mouth, con- 
sisting of the hard and soft palate. 
Pan'cre-as (Greek, pas, pantos, all, and kreas, flesh). A long, flat 
gland placed behind the stomach; in the lower animals this organ is 
called the sweet-bread. 
Pan-cre-at'ic Juice. The secretion produced by the pancreas. 
Pa-pil'lse (Latin, plural of papilla). The minute elevations in which 
terminate the fibers of the nerves of touch and taste. 
Pa-ral'y-sis (Greek, paraluo, to loosen). A disease of the nervous 
system marked by the loss of sensation, or voluntary motion, or 
both ; palsy. 
Pa-tel'la (Latin, diminutive of patina, a pan). The knee-pan ; a 
small bone. 
Pel'vis (Latin, a basin). The bony cavity at the lower part of the 
trunk ; the hip-bone. 
Per-i-car'di-um (Greek, peri, about, and kardia, heart). The sac in- 
closing the heart. 
Per-i-os'te-um (Greek, peti, around, and osteon, a bone). A fibrous 
membrane surrounding the bones. 
Per-spi-ra'tion (Latin, perspiro, to breathe through). The sweat, or 
watery fluid poured out from the skin ; when visible, it is called 
sensible perspiration ; when invisible, it is called insensible perspira- 
tion. 
Phar'ynx (Greek, pharunx, the throat). The muscular passage lead- 
ing from the back part of the mouth to the esophagus. 
Phys-i-ol'o-gy (Greek, phusis, nature, and logos, a discourse). The 
science of the functions of living, organized beings; the study of 
the natural actions of the living body. 
Pig'ment (Latin, pingo, to paint). Coloring-matter. WHAT THE WORDS MEAN. 
Plant'i-grads (Latin, planta, the sole of the foot, and gradi, to walk). 
An animal that walks on the sole of the foot, as the bear. 
Pleu'ra (Greek, a rib). A membrane covering the lung and lining the 
chest. There is one for each lung. 
Pneu-rao'nia (Greek, pneuma, air, and pnco, to breathe). An inflam- 
mation affecting the air-cells of the lungs. 
Por'tal Vein (Latin, porta, a gateway). The venous trunk formed 
by the union of all the veins coming from the intestine. It conveys 
the blood to the liver. 
Proc'ess (Latin, procedo, processus, to proceed, to go forth). Any 
projection from a surface. Also, a method of doing anything. 
Pro'te-id (Greek, protos, first, and eidos, form). An element allied to 
nitrogen ; a substance containing such elements ; an albuminoid. 
Pul'mo-na-ry (Latin, pulmo, pulmonis, the lungs). Pertaining to the 
lungs. 
Pulse (Latin, pello, pulsum, to beat). The striking of an artery against 
the finger, occasioned by the contraction of the heart, commonly 
felt at the wrist. 
Pun'gent (Latin, pungo, to prick). Sharply painful or biting. 
Pu'pil (Latin,pupilla). The central, round opening in the iris, through 
which light passes into the depths of the eye. 
Py-lo'rus (Greek, puloros, a gate-keeper). The lower opening of the 
stomach, through which the food passes into the intestine ; so called 
on account of a circular band of muscular fibers by which the passage 
is guarded. 
Qui'nine (Spanish, quina, Peruvian bark). An extract of Peruvian 
bark used to cure fever, and give vigor to the sj'stem. 
Ra'di-us (Latin, a spoke of a wheel). The bone on the thumb-side 
of the fore-arm. 
Re'flex Ac'tion. An involuntary action of the nervous system, by 
which an external impression conducted by a sensory nerve is re- 
flected, or changed into a motor impulse. 
Res-pi-ra'tion (Latin, re, denoting repetition, and spiro, to breathe). 
The function of breathing, comprising two acts: inspiration, or 
breathing in, and expiration, or breathing out. 
Ret'i-na (Latin, rete, a net). The membranous expansion of the optic 
nerve in the interior of the eyeball, which receives the impressions 
resulting in the sense of vision. 
Rib. One of the long bones inclosing the cavity of the chest. In man 
there are twelve on each side. The upper seven are called true ribs; 152 
WHAT THE WORDS MEAN. 
the other five are the false fibs, of which the last two are called 
floating ribs. 
Sa-li'va (Latin), The moisture or fluids of the mouth, secreted by 
the salivary glands. 
Sal'i-va-ry Gland. A gland which produces saliva. 
Sar-to'ri-us (Latin, sartor, a tailor). The muscle which throws one 
leg across the other. 
Scalp (Latin, scalpo, to cut). The part of the skin of the head usually 
covered with hair. It is the part cut off by Indian warriors as a 
token of victory over an enemy. 
Scap'u-la. The shoulder-blade. 
Scarf-Skin. The outer layer of the skin ; the cuticle, or epidermis. 
Scle-rot'ic (Greek, skleros, hard). The tough, fibrous outer coat of 
the eyeball. 
Se-ba'ce-ous (Latin, sebum, fat). Resembling fat; the name of the 
oily secretion by which the skin is kept flexible and soft. 
Se-cre'tion (Latin, secerno, secretum, to separate). The process of 
separating from the blood some important fluid ; the fluid is also 
called a secretion. 
Sen-sa'tion (Latin, sensus, sense). The conscious perception of an 
external impression by the nervous system ; a function of the 
brain. 
Sen’so-ry Nerve (Latin, sentio, to perceive). A nerve of sense. 
Se'rum (Latin, whey, buttermilk). The clear, watery fluid which 
separates from the clot of the blood. It contains, besides water, 
albumen and mineral substances. 
Shaft. A long, slender body, like a stem or stalk. 
Shoulder-Blade. The flat, triangular bone of the shoulder ; the 
scapula. 
Skel'e-ton (Greek, a dried body). The bony frame-work of an animal, 
the different parts of which are kept in their proper relative posi- 
tions. 
Skull (a shell or bone). The bony case which incloses the brain. 
Sock'et (Latin, soccus, a kind of low-heeled shoe). An opening into 
which anything is fitted. 
Spasm (Greek, spasmos, convulsion). A sudden, violent, and invol- 
untary contraction of one or more muscles or muscular fibers. 
Spe'cial Sense. A sense by which we receive particular sensations, 
differing from those of general sensibility ; such as those of sight, 
hearing, taste, and smeli. WHAT THE WORDS MEAN.. 
153 
Spe-cif'ic Grav'i-ty. The ratio of the weight of a body to the weight 
of an equal bulk of some other body, usually water, taken as the 
standard. 
Spher'i-cal (Latin, sphera, a globe). Having the form of a sphere. 
Spinal Col'umn. The connected vertebrae of the back ; the back- 
bone ; the spine. 
Spi'nal Cord. A cylinder-shaped mass of nervous matter situated in 
the cavity of the spinal column. 
Spine (Latin, spina, a thorn). A projecting point or ridge of bone. 
Spleen. An organ largely made up of small vessels, and situated 
within the abdomen, near the left extremity of the stomach. 
Ster'num (Greek, sternon, the breast). A flat, rectangular bone, ex- 
tending vertically along the middle of the chest, to which the seven 
upper ribs are attached. 
Stim'u-lant (Latin, stiniulo, to prick or goad on). An agent which 
causes an increase of vital activity in the body or any of its parts. 
Stri'a-ted (Latin, sh io, to furnish with channels). Marked with fine 
parallel lines. 
Sub-cla'vi-an Vein (Latin, sub, under, and clavis, a key). The great 
vein bringing back the* blood from the arm and side of the head; so 
called because it is situated underneath the clavicle, or collar-bone. 
Su-pe'ri-or Ve'na Ca'va (Latin, upper hollow vein). The great vein 
of the upper part of the body. 
Sur'ger-y. That branch of medical science which treats of manual 
operations for the healing of diseases or bodily injuries. 
Sut'ure (Latin, suo, to sew or stitch). The seam or joint which unites 
the bones of the skull. 
Sym-pa-thet'ic Sys'tem of Nerves. A double chain of nervous 
ganglions connected together by numerous small nerves, situated 
chiefly in front of and on each side of the spinal column. 
Symp'tom (Greek, sum, with, and pipto, to fall). A sign or token of 
disease. 
Sys-tem'ic. Belonging to the system, or body, as a whole. 
Tar'tar. A hard crust which forms on the teeth, and is composed of 
salivary mucus, animal matter, and a compound of lime. 
Tem'ple (Latin, tempus, time, and tempora, the temples). The part 
of the head between the ear and the forehead ; so called because 
the hair begins to turn white with age in that portion of the scalp. 
Ten'don (Latin, tendo, to stretch). The white, fibrous cord or band 
by which a muscle is attached to a bone ; a sinew. 154 
WHAT THE WORDS MEAN. 
Text'ure (Latin, iexo, to weave). The particular arrangement of tis- 
sues that form an organ. 
Tho-rac'ic Duct (Greek, thorax, the chest). A narrow tube running 
from below upward within the back part of the chest, which is the 
main trunk of the lymphatic vessels. 
Tho'rax (Greek, thorax, a breast-plate). The upper cavity of the 
trunk of the body, containing the lungs, heart, etc.; the chest. 
Tib'i-a. The principal bone of the leg below the knee. 
Tis'sue. Any substance or texture in the body formed of various ele- 
ments, such as cells, fibers, blood-vessels, etc., interwoven with each 
other. 
To-bac co (Indian, tabaco, the tube or pipe in which the Indians 
smoked the plant). A plant used for smoking and chewing and in 
snuff. It has a strong smell and a pungent taste. 
Tra'che-a (Greek, trachus, rough). The windpipe, or the largest of 
the air-passages; composed in part of rings of cartilage, which 
render its surface rough and uneven. 
Trans-par'ent (Latin, trans, through, and pareo, to appear). Capable 
of allowing light to pass through. Transparent bodies can be seen 
through. 
Tri'ceps (Latin, tria, three, and caput, head). The large muscle 
which straightens the arm, or that which extends the leg. 
True Skin. The inner layer of the skin ; the cutis vera, or derma. 
Trunk. The body, apart from the limbs. 
Tym'pa-num (Greek, tumpation, a drum). The cavity of the middle 
ear, resembling a drum in being closed by two membranes, and in 
having communication with the atmosphere. 
Ul'na (Latin, the elbow). The bone of the fore-arm on the little- 
finger side. 
Var'i-cose (Latin, vaiix, a dilated vein). Unnaturally enlarged—ap- 
plied only to veins. 
Vein. A vessel serving to convey the blood from the various organs 
Ve'nous (Latin, vena, a vein). Pertaining to, or contained within, a 
vein. 
inward to the heart. 
Ven-ti-la'tion (Latin, ventus, wind). The introduction of fresh air 
into a room or building in such a manner as to keep the air within 
it in a precondition. 
Ven'tri-cle (Latin, ventriculus, a little stomach). The larger and 
thicker chamber of the heart, on each side, which receives the WHAT THE WORDS MEAN. 
155 
blood from the corresponding auricle, and discharges it into the 
artery. 
Ver'te-bra (Latin, vertebra, a joint). One of twenty-six separate 
bones, called vertebrae, firmly jointed together to form the spinal 
column. 
Ver'te-brate. Having a backbone formed of vertebrae. 
Vi-bra'tion (Latin, vibro, to move to and fro). Quick motion to and 
fro. 
Vi-tal'i-ty (Latin, vita, life). The state or quality of being full of 
life. 
Vit're-ous (Latin, vitrum, glass). Having the nature of glass. 
Vo'cal Cords (Latin, vox, vocis, the voice). Two elastic bands or 
ridges situated in the larynx ; they are the essential parts of the 
organs of the voice. Their vibrations, communicated to the air, 
produce the sound of the voice. 
Vol'un-ta-ry (Latin, voluntas, will). Under control or direction of 
the will. TOPICAL ANALYSIS. 
CHAPTER 
I.—The Body and its Parts. 
1. The head, neck, trunk, and limbs seen. 
2. The internal organs not seen. 
3. To avoid injury of outward parts. 
4. To care for organs within the body. 
5. To secure health. 
6. To improve looks. 
7. To increase usefulness. 
Why we should 
Study our 
Bodies. 
1. The arms. 
2. The legs. 
3. The joints: ball-and-socket—hinge—compound. 
4. Parts in pairs. 
5. Bodies of other animals. 
6. Uses of parts of the body. 
7. Intelligent care of the body. 
About Parts of 
the Body. 
Something to find out. TOPICAL ANALYSIS. 
CHAPTER 
ll.—Eating, and what comes of it. 
Why we Eat. 
1. The body always wearing out. 
2. It needs repair. 
3. We eat to live. 
4. We eat to do the work we have to do. 
1. Different elements needed. 
2. Food related to the industries. 
3. Food related to geography. 
Different elements needed. 
Food related to the industries. 
Proteids : gluten —albumen 
fibrine—caseine—gelatine. 
Amyloids ; starch sugar 
gums. 
Fats: animal and vegetable 
oils. 
Minerals : lime—soda—potash 
—iron—salt—water. 
What we Eat. 
4. Kinds of food. - 
5. Special foods; vegetables—meats—fruits. 
6. Value of different foods. 
7. Ways of cooking. 
8. Mixed foods necessaiy. 
How we Eat. 
Mastication. 
1. Mastication. 
2. The teeth ; structure—names—uses. 
3. Care of the teeth: necessity—implements. 
1. How saliva flows—exciting causes. 
2. Amount of saliva. 
3. How saliva is wasted. 
4. Tobacco: wastes saliva—vitiates saliva—defiles 
the breath. 
5. The esophagus : structure—action. 
How we Swal- 
low. 
Hygiene of mastication. 
Something to find out. 158 
TOPICAL ANALYSIS. 
CHAPTER 
111.—How- Digestion goes on. 
1. Structure of stomach. 
2. Muscular action. 
3. The gastric juice. 
4. The absorbents. 
5. Starchy foods changed to sugar by action of 
saliva. 
6. Proteids dissolved by gastric juice. 
7. Chyme. 
8. Character and amount of drink. 
9. Alcohol in the stomach: 
1. Stimulates action. 
2. Hardens mucous coat. 
3. Continued use inflames. 
4. Produces abnormal cravings. 
10. Care of the stomach : 
1. Food properly prepared. 
2. Taken in proper quantities. 
3. Taken at proper times. 
Stomach Diges- 
tion. 
1. The intestines: structure—juices—action. 
2. The duodenum. 
3. The pancreas ; pancreatic juice—uses. 
4. The liver; bile—nature—uses. 
5. Alcohol in the liver: 
1. Stimulates action. 
2. Hardens tissue. 
3. Continued use inflames. 
Intestinal Di- 
gestion. 
6. The absorbents; portal vein—liver, 
7. The lacteals : chyle—the thoracic duct. 
8. Summary of changes ; 
1. Food masticated and mixed with saliva. 
2. Starch reduced by saliva and by action of 
pancreatic juice. 
3. Proteids reduced by gastric juice. 
4. Fats reduced by pancreatic juice and bile. 
5. Acids neutralized by the alkali of the bile. 
2. 
3- 
4- 
5- 
Hygiene of digestion. 
Something to find out. TOPICAL ANALYSIS. 
159 
CHAPTER 
IV.—How the Blood gets purified. 
1. The heart: shape—position—covering. 
2. The plan of the heart: 
1. The pulmonary heart. 
2. The systemic heart. 
3. The auricles, ventricles, and valves. 
3. The pulmonary artery. 
4. Pulmonary action : 
1. From vein to right auricle. 
2. From auricle to right ventricle. 
3. From ventricle to pulmonary artery. 
Movement of the 
Blood, 
1. The lungs : elastic tissue—the lobes—the pleura. 
1. Air-spaces: air-cells bronchial tubes 
trachea—larynx—glottis. 
2. Blood-flow : around air-cells return in 
pulmonary veins. 
2. The chest varies in capacity: 
1. By action of intercostal muscles. 
2. Movement of ribs and diaphragm. 
3. Forces in breathing; 
1. The pressure of the air. 
2. The elastic force of the lungs. 
4. Action in the lungs : 
1. Oxygen passes from air-cells into the blood. 
2. Impure matter from blood passes into the 
air-cells. 
Breathing, 
1. Effort to expel alcohol with the breath. 
2. Enfeebles the lungs. 
3. Induces disease. 
4. The blood imperfectly purified. 
Alcohol in the 
Lungs. 
1. Tobacco-fumes drawn into the lungs, 
2. Retards lung-action. 
3. Produces languor and stupidity. 
4. Retards bodily growth, 
5. Enfeebles the mind. 
Tobacco in the 
Lungs. 
The Need of Pure Air. Ventilation. 
Hygiene of respiration. 
Something to find out. TOPICAL ANALYSIS. 
CHAPTER V.-How the Blood nurtures the Body. 
Waste and Re- 
pair. 
1. Action wears out tissue. 
2. The blood the agent of repair. 
Channels of Cir- 
culation. 
1. The arteries ; structure—the aorta—branches. 
2. The capillaries : size—extent. 
3. The veins: structure—termination. 
1. F rom pulmonary vein to left auricle. 
2. From auricle to left ventricle. 
3. From ventricle to aorta. 
Action in the 
Heart. 
1. Place of the arteries. 
2. Jets of blood with each heart-beat. 
3. Elasticity of the walls of the arteries. 
4. The pulse, and what it indicates. 
Action in the 
A rteries. 
1. Oxygen burns living tissue. 
2. The burning causes heat and motion, 
3. Worn-out particles are removed, 
4. New particles are deposited. 
5. The color of the blood is changed. 
Action in the 
Capillaries. 
Action in the 
Veins. 
1. The current flows evenly. 
2. The valves open toward the heart. 
3. Muscular action assists the blood-flow. 
4. Varicose veins. 
1. Does not become a part of the blood. 
2. Causes red-blood corpuscles to shrink. 
3. Deprives the blood of oxygen. 
4. Interrupts combustion and repair. 
5. Changes muscles of the heart into fat. 
6. Gorges minute arteries with blood. 
A Icohol in the 
Blood. 
Hygiene of the circulation. 
Something to find out. TOPICAL ANALYSIS. 
161 
CHAPTER 
VI.—How the Body moves. 
Motion neces- 
sary. 
1. The motion of the body and its parts indicates life. 
2. Want of motion is the sign of death. 
The Muscles. 
1. The muscles produce motion and give beauty to 
the form. 
2. General structure : connective tissue swell 
muscles—hollow muscles—tendons—ligaments. 
Muscular Ac- 
tion. 
1. Contraction and expansion. 
2. Voluntary and involuntary action. 
3. Flexors and extensors. 
I. Repair of muscles : 
1. The blood supplies nourishment. 
2. Muscles most exercised receive most nour- 
ishment. 
Care of the 
Muscles. 
2. Exercise of muscles: work—games—calisthenics. 
3. Rest of muscles : after exercise—after injury. ■ 
4. Proper position : in sitting—in standing. 
5. Dress must leave the muscles free. 
6. Alcohol changes muscular fiber to fat. 
7. Agreeable occupation lightens labor. 
' I. Exercise should be for health. 
2. The body should serve the mind. 
3. Muscular development not for display. 
4. Muscles should not monopolize energies. 
Exercise. 
Hygiene of the muscles. 
Something to find out. 162 
TOPICAL ANALYSIS. 
CHAPTER 
Vll.—How the Body is able to stand. 
The Need of a 
Bodily Frame. 
1. To stand erect. 
2. To keep the body in proper form. 
1. Uses of the bones ; 
1. To give shape to the body. 
2. To protect delicate organs. 
3. To afford attachment for muscles. 
2. Forms of the bones. 
3. Structure of the bones. 
4. Materials : animal matter—mineral matter. 
5. Growth and repair. 
The Bones. 
1. Bones of the head ; skull—sutures—face. 
2. Bones of the trunk : pelvis—spinal column— 
ribs breastbone shoulder-blade—col- 
lar-bone. 
Distribution of 
the Bones. 
| 3. Bones of the arm: humerus—ulna and radius—• 
the wrist-bones—the hand. 
4. Bones of the legs ; femur—patella—tibia and 
fibula—ankle—foot—arch of the foot. 
_ 5. Bony cavities ; skull—chest—pelvis. 
( 1. How produced. 
\ 2. How shocks are distributed. 
Bodily Move- 
ments. 
How produced. 
How shocks are distributed. 
r. Proper food. 
2. Suitable exercise. 
3. Moderate exercise in childhood. 
4. Proper positions. 
5. Easy clothing. 
6. Shoes of proper form and material. 
7. Rest after injury. 
Care of the 
Bones. % 
Hygiene of the bones. 
Something to find out. TOPICAL ANALYSIS. 
163 
CHAPTER 
Vlll.—Plow the Body is covered. 
Uses of Cover- 
ing. 
X. Protects internal organs. 
2. Performs important functions. 
1. Structure varies : callus—corns—nails—hair. 
2. Layers of the skin : 
1. The scarf-skin ; dandruff—pigment-cells— 
complexion. 
2. The true skin ; papillae—hair-follicles. 
3. How the skin is kept soft: oil-tubes—sebaceous 
glands. 
Structure of the 
Skin. 
1. Casting out waste; the sweat-glands—the kid- 
neys. 
2. Regulating heat: sensible and insensible perspi- 
ration. 
3. How the skin absorbs. 
1. Cleanliness of the skin : necessity—bathing. 
2. Temperature of the skin; clothing—artificial 
heat. 
Function of the 
Skin. 
Care of the Skin. 
1. Uses of the hair; 
1. Protects from extreme heat and cold. 
2. Breaks the force of blows. 
3. Shields organs of sense from injury. 
2. Structure of hair : the pith—the shaft—the root, 
3. Health of the hair : 
1. Dependent on general health of the body. 
2. Necessity of cleanliness. 
3. Grayness and loss of hair. 
4. Effect of emotion. 
The Hair. 
1. Clothing protects and adorns. 
2. It should be sufficient in quantity. 
3. It should be suited to circumstances. 
4. It should be clean and dry. 
5. It should be easy. 
Clothing. 
Hygiene of the skin. 
Something to find out. 164 
TOPICAL ANALYSIS. 
CHAPTER 
IX.—How Bodily Motion is directed. 
1. To produce harmony of action. 
2. To nurture the body. 
3. To execute plans. 
Direction neces- 
sary. 
Distribution of 
Nerves. 
1. Resemblance to blood-vessels. 
2. Extending from nerve-centers. 
3. Reaching every part of the body. 
4. In double sets. 
Nerve-Ma tier. 
1. Gray matter : cells, 
2. White matter ; threads. 
1. The brain : cerebrum cerebellum convolu- 
tions— double structure twelve pairs 
cranial nerves. 
2. The spinal cord : the medulla oblongata—thirty- 
one pairs spinal nerves. 
3. The ganglions; general—sympathetic. 
Nerve-Centers. 
1. Sensory nerves conveying sensations. 
2. Motor nerves controlling motion. 
1. Direct from brain. 
2. Reflex from spinal cord. 
3. Sympathetic from sympathetic ganglions, 
4. Habit and training. 
Nerve-Function. 
Nerve-Action. 
Care of the 
Nerves. 
1. Exercise of the nerves. 
2. Rest of the nerves ; diversion—sleep. 
3. Effect of emotion ; joy—grief. 
1. Absorbs moisture from nerve-tissue. 
2. Diminishes nerve-action. 
3. Gorges the small arteries with blood, 
4. Weakens the heart-action. 
5. Leaves muscles without control. 
6. Deranges the vital organs. 
7. Paralyzes cerebral action. 
8. Debases the higher nature. 
9. Produces delirium. 
Effect of Alco- 
hoi. 
Effect of Tobac- 
co. 
1. Diminishes nervous action. 
2. Diminishes action of the heart. 
3. Evil effects transmitted to children. 
Hygiene of the net ves. 
Something to find out. 165 
TOPICAL ANALYSIS. 
CHAPTER X. How the Mind gets Ideas and expresses 
them. 
Use of the Spe- 
cial Senses. 
1. To carry sensations to the mind. 
2. To produce ideas in the mind. 
' 1. Taste a sentinel guarding the stomach. 
2. The gustatory nerve. 
3. How flavors are perceived. 
c 4. Palatable foods. 
The Sense of 
Taste. 
” 1. The olfactory nerve. 
2. How odors are perceived. 
3. Agreeable and disagreeable odors. 
__ 4. A guard to eating and breathing. 
The Sense of 
Smell. 
The Sense of 
Hearing. 
' 1. Sound-vibrations : the auditory nerve—hearing. 
2. The ear: external middle internal Eusta- 
chian tube. 
3. Care of the ear. 
r. Light-vibrations : the optic nerve—sight. 
2. Need of light; 
X. To protect the body from injury. 
2. To observe beauty in the world. 
3. The eye : form and position—structure—muscles. 
4. Action of light: how regulated—produces vision 
5. Care of the eye : direction of light—use of glasses 
—intensity of light. 
The Sense of 
Seeing. 
The Organs of 
Speech. 
1. The need of expression. 
2. The voice : the larynx—the glottis—the vocal 
cords, 
3. Speech: pitch—quality—quantity—articulation. 
4. Care of the voice—pleasant tones—avoid strain- 
ing the voice. 
Hygiene of the organs of special sense. 
Something to find out. BONES OF THE BODY. 
The Plead—29 Bones. 
BONES OF THE BODY. 
Front'al {frontale, frontlet—one in forehead). 
Pa-ri'e-tai {paries, wall—one on each side of head). 
Tem'po-ral {tempus, time—one in each temple). 
Sphe'noid {sphenos, wedge—one at base of skull, be- 
tween temples and cheeks). 
Eth'moid {ethrnos, sieve—one between cavity of skull 
and upper part of nose). 
Oc-cip'i-tal {occiput, back of head—one at base of 
skull). 
Skull. 
(8 bones.) 
Mal le-us (mallet—outermost of chain, one in each ear). 
In'cus (anvil—middle of chain, one in each ear). 
Sta'pes (stirrup—innermost of chain, one in each ear). 
Ears. 
(6 bones.)* 
Lacb'ry-mal {lacryma, tear—one in each orbit). 
Na'sal {nasus, nose—two, forming bridge of nose). 
Ma'lar {mala, cheek—one in each cheek), 
Tur'bi-nate {turben, whirl—one in outer wall of each 
nostril). 
Pal'a-tal {palatum, palate—two, completing skeleton 
of hard palate). 
Vo'mer (plowshare—separating nostrils). 
Su-pe'ri-or Max'il-la-ry {superior maxilla, upper jaw- 
bone—two, forming upper jaw). 
In-fe'ri-or Max'il-la-ry {inferior, lower—one in lower 
jaw). • 
Face. 
(14 bones.)} 
Ily'oid (v and eidos, form, —one in neck at 
base of tongue). 
* In early life there is a fourth bone between the incus and the 
stapes in each ear, but later it becomes a part of the incus. 
f As the teeth are developed from the mucous membrane, they are 
not usually looked upon as belonging to the skeleton. The temporary, 
or “ milk,” set contains eight incisors, four canines, and eight molars. 
The permanent set may be tabulated as follows; 
In-ci'sors (incido, to cut—four in the front of each jaw). 
Ca-nines' (canis, dog—one on each side of each jaw, behind the 
incisors). 
Bi-cus'pids (hi, two, and cuspis, prominence—two on each side 
of each jaw behind the canines). 
Mo'lars (viola, mill—three on each side of each jaw, behind the 
bicuspids). 
Teeth. 
(32 in number.) 
JL BONES OF THE BODY. 
167 
The Trunk*—57 Bones. 
Cer'vi-cal Ver'te-brse {cervix, neck seven in the 
neck). 
Dorsal Ver'te-bne (Idorsum, back twelve in the 
back). 
Lum'bar Ver'te-bros (lumbus, loin—five in the loins). 
Spine. 
(24 bones.) 
Scap'u-la (shoulder-blade—one on upper part of back 
on each side). 
Clav'i-cle {clavis, key—one on each side, between top 
of breastbone and point of shoulder). 
Shoulder. 
(4 bones.) 
Sternum (sternon, breast one extending vertically along middle of 
chest). 
Hibs. 
(24 bones.) 
True (upper seven pairs attached to spine, and tied 
directly to breastbone by cartilages). 
False (lower five pairs attached to spine ; three pairs 
tied to cartilages of preceding rib ; two pairs “ float- 
ing ” unattached in front). 
In-nom'-i-nate {in, not, and nomino, to name—two 
main bones of pelvis, forming hips). 
Sa'crum (sacred—one between innominate bones, 
formed of five consolidated vertebras). 
Coc'cyx (cuckoo—one below sacrum, formed of four 
consolidated vertebrae). 
Pelvis. 
(4 bones.) 
The Limbs—120 Bones. 
Hu'me-rus (upper arm—one in each arm). 
Ul'na (elbow—one in each forearm, joined to the 
humerus). 
Ra'di-us (spoke—one in exterior of each forearm, 
moving around ulna). 
Car'pal (carpus, wrist—eight in each wrist). 
Met-a-car'pal (meta, beyond, carpus, wrist—five in 
each hand, between wrist and fingers), 
Pha-lan'ges (battalions—three in each finger, two in 
each thumb). 
Upper. 
(60 bones.) f 
* Strictly, the scapula and the clavicle belong neither to the trunk 
nor the arms, but simply connect them. The sacrum and the coccyx 
may be classified as belonging to the spine. 
f At the joints of the thumbs and great toes are pairs of small bones, 
eight in all, called sesamoid bones (sesamon, sesame-seed, and eidos, like). 168 
BONES OF THE BODY. 
Fe'mur (thigh-bone—one in each leg). 
Pa-tel'la (little pan—one covering each knee-joint). 
Tib'i-a (shin-bone—one in each leg, between knee 
and ankle). 
Fib'u-la (clasp—one bracing tibia in each leg). 
Tar'sal (tarsus, flat of foot—seven in each instep). 
Met-a-tar'sal (meta, beyond, and tarsus—five in each 
foot, between ankle and toes). 
Pha-lan'ges (battalions—two in each great-toe, three 
in each of the others).* 
Lower. 
(60 bones.) 
* The confusion about the number of bones in the body arises from 
counting them at different ages and omitting different sets. The fol- 
lowing successive additions will explain the various numbers : 
General bones of the skeleton 200 
Bones of the ear in adults 6 
Additional bones in the ear in children 2 
206 
The permanent teeth 32 
208 
240 
The sesamoid bones 8 
248 WHERE TO FIND THINGS. 
Abdomen, 35. 
Absorbent vessels, 37. 
Absorption, 41. 
by blood-vessels, g6. 
by the lacteals, 41. 
by the skin, 91, g6. 
of the food, 37. 
Acid, muriatic, 7g, Bg. 
Adam’s apple, 50. 
Air, atmospheric, 124. 
changes in, in respiration, 52, 
carbonic acid in, 52. 
dust in the, 52. 
effects of impure, 54, 118. 
impurities in, 54. 
need of ventilation, 55, 57. 
pressure of, 51. 
provision for purifying, 46. 
waste matter expired in, 52. 
Air-cells of the lungs, 50. 
Air-passages, 50. 
Albinos, 94, 129. 
Albumen, 22. 
Albuminoid substances, 23. 
varieties of, 23. 
Alcohol, 6. 
effects upon the brain, 116. 
effects upon digestion, 37. 
effects upon the face, 62. 
effects upon the heart, 62, 117. 
effects upon the mind, Ix 7. 
effects upon the nerves, 113,116, 
118. 
Alcohol, habit of drinking, 38, 45 
hostile to life, 37, 41, 117. 
in the arteries, 62. 
in the blood, 53, 61. 
in the breath, 53, 118. 
in the liver, 41. 
in the lungs, 53. 
in the stomach, 37. 
the poisonous effects of, 38, 
unchanged in the stomach, 38. 
Alimentary canal, 68, 137. 
Alkali, 40, 43, 138. 
Amyloids, 23. 
Animal functions, 4. 
Animal heat, 23, 37. 
how produced, 23. 
regulated by perspiration, 95. 
Antagonistic muscles, 69, 87. 
Antoinette, Marie, 100. 
Anxiety affects the hair, 100. 
Aorta, 59. 
Appetite, 43. 
inherited, 118. 
Apples, 25. 
Application of knowledge, 7. 
Aqueous humor, 130. 
Arch of the foot, 84, 87. 
Arms, 15, 83. 
Aroma, 124. 
Arrowroot, 23. 
Arterial blood, 53. 
differs from venous, 52, 53. 
Aiteries, 48, 58. WHERE TO FIND THINGS. 
Arteries, distribution of, 59. 
pulsation of, 60. 
structure of, 59. 
Athletic sports, 74. 
Auditory canal, 126. 
nerves, 125. 
Auricles of the heart, 48. 
Bodily motion directed, 107. 
Body, 13. 
care of, xB. 
cavities of, 85. 
clothing of, 73, 100, xox. 
movements of, 73, 85. 
of other animals, 17. 
repair of, 58. 
temperature of, 95. 
uses of parts of, 18. 
why we should study the, 13 
Bones, 77. 
color of, 79. 
composition of, 79. 
deformity of, 85, 88, Bg, 103. 
growth of, 80. 
hygiene of, 88. 
moved by muscles, 85. 
of arms, 83. 
of head, 80, 
of legs, 84. 
of trunk, 81. 
repair of, 80. 
size and shape of, 78. 
structure of, 78. 
uses of, 77. 
Brain, 108. 
care of, 118, 119. 
congestion of, 116. 
effects of alcohol upon, 116. 
exercise of, 115, 118. 
function of, Ix 4. 
injuries of, 116. 
sensitiveness of, 85. 
softening of, 116. 
structure of, 109. 
Bread, 22. 
and butter, 25. 
Breast-bone, 83. 
Breath, effect of alcohol upon, 
53. 57- 
effect of tobacco upon, 31. 
Breathing, 51, 52, 124, 
control of, 113. 
forces in, 51. 
process of, 51. 
Bronchi, 50. 
Bronchial tubes, 50. 
Brunette complexion, 92. 
Backbone, 82. 
Ball-catcher, 87. 
Bathing, 97. 
importance of, 97. 
time and manner of, 98. 
Baths, 97, 98. 
different kinds of, 98. 
of soup, 96. 
of wine, 96. 
Bath-tub, 98. 
Beans, 23, 24. 
Beauty in the world, 128. 
Beef, 24. 
Beer, 75. 
Beets, 23. 
Biceps muscle, 86. 
Bile, 39., 
secretion of, in the liver, 40. 
uses of, 40, 43. 
Bitterness, 123. 
Blackberries, 25. 
Blacksmith, 70. 
Bleeding, how stopped, 64, 65. 
Blonde complexion, 92. 
Blood, 58. 
arterial, 53. 
change of color, 53, 61. 
circulation of, 58. 
clotting of, 64. 
course of, 60, 61. 
injux-ed by chewing tobacco, 31. 
making of, 18. 
•purification of, in lungs, 46, 52. 
uses of the, 18. 
venous, 46. 
Blood-vessels, 48, 129. 
of the skin, 96, 
absorption by, 96. 
injuries to, 60, 61, 63. 
Blushing, 96. 
Bodily covering, 91. WHERE TO FIND THINGS. 
Bunions, 85. 
Burns, 106. 
Butter, 25. 
Clavicle, 83. 
Clot, 64. 
Clothing, 100, 104. 
not to be worn tight, 55, 88, 103. 
poisonous, 103. 
should hang from shoulders, 55. 
Coffee, 22. 
Colds, 95, 101, 103, 126. 
Collar-bone, 83. 
Color, differences in, 128. 
Coloring-matter, 92, 129. 
Column, spinal, 82. 
Comfort, 97. 
Complexion, 92. 
affected by heat and light, 93. 
Connective tissue, 67. 
Consumption, 53, 103. 
Contraction of heart, 46, 59. 
of muscles, 68. 
Convolutions of the brain, 109. 
Cooking, 24. 
Cords, vocal, 132. 
Cornea, 129. 
Corn-meal, 24. 
Corns on the feet, 85, 92. 
Cotton, 101. 
Coughing, 113. 
Covering, bodily, 91. 
Crabs, 24. 
Cramming for examination, 119. 
Cross-eyes, 130. 
Crystalline lens, 130. 
uses of, 131. 
Currants, 25. 
Curvature of spine, 89. 
Cuticle, 92., 
structure of, 92. 
Cutis vera, 93. 
Dandruff, 92. 
Danger from eating, 43, 124. 
Death, 66. 
caused by alcohol, 37, 117. 
Deformity, 102. 
of bones, 88. 
of feet, 85, 103. 
of legs, 88. 
of shoulders, 74, 75, 
of waist, 88, 103. 
Calisthenics, 74. 
Callus, 92. 
Candy, 43. 
Capillary blood-vessels, 59. 
circulation in the, 60. 
Carbonic acid, 52. 
exhaled from the lungs, 52. 
in the air, 52. 
supports vegetable life, 52. 
Cardia, 36. 
Cartilage, 82, 83. 
Caseine, 23. 
Catarrh, 103. 
Cavities of body, 35. 
Cells, nerve, 108. 
Cerebellum, 109. 
function of the, 117. 
Cerebrum, 109. 
function of the, 117. 
Cheek-bone, 86. 
Cheeks, 26. 
Cheese, 23. 
Cherries, 25. 
Chest, 35. 
frame-work of, 82. 
variation in size of, 50. 
Chewing of food, 26. 
Chicken, 24. 
Chilliness, ioi, 104. 
Choroid coat of the eye, 129. 
Chyle, 41. 
Chyme, 37. 
Cigarette-smoking, 54. 
Circulation, 58. 
cause of, 58. 
hygiene of, 62. 
of the blood, 58. 
rapidity of, 60. 
through the heart, 59. 
through the lungs, 52. 
Circus, 76. 
Clams, 24. 
Cleanliness, 97. 
helps morality, 97. 
of animals, 97. WHERE TO FIND THINGS. 
Delirium, 117. 
Dentine, 27. 
Derma, 93. 
“Deserted Village,” 135. 
Diaphragm, movements of the, in 
respiration, 35, 51. 
Diet, mixed, 25. 
necessity of a regulated, 43. 
Digestion, 35. 
circumstances affecting, 43, 99. 
effects of alcohol upon, 37, 44. 
effects of tobacco upon, 44. 
general plan of, 42. 
hygiene of, 43. 
in the intestines, 38. 
in the stomach, 36. 
nature of, 35. 
organs of, 35, 38, 39, 40. 
Digitigrade, xg. 
Direct nerve-action, 112. 
Dirt, 97. 
Drainage, 55. 
Drink, 37. 
Drunkenness, 117. 
Duct, thoracic, 42. 
Duodenum, 39. 
Epiglottis, uses of, 31, 
Esophagus, 31. 
Eustachian tube, 126. 
Exercise, 71, 72. 
different modes of, 74, 75. 
effects of, 61. 
excessive, 72. 
for health, not strength, 71. 
importance of, 63, 88, 103, 118. 
of the nerves, 115. 
open-air, 65. 
Expiration, 52. 
movements of, 52. 
Extensor muscles, 6g. 
Eye, 128. 
care of, 103, 131, 133. 
muscles of, 87. 
of a cat, 130, 135. 
of an ox, 131. 
structure of, 129. 
Eyeball, 128. 
Eyelashes, 128. 
Eyelids, 99, 128. 
Fainting, 116. 
False ribs, 83. 
Farming, 22. 
Fats, 23. 
source of, in food, 23. 
Fear affects the hair, 100. 
Femur, 84. 
Fibers, muscular, 67, 63. 
nerve, 108. 
Fibrils, 67. 
Fibrine, 23. 
Fibula, 84. 
Fire-kings, 96. 
Fish, as food, 24. 
Flannels, xor. 
Flavors, 122, 123. 
Flesh, 24. 
Flexor muscles, 69. 
Floating ribs, 83. 
Flour, 22. 
Flowers, 134, 135. 
Foods, 22, 23, 24, 25, 123. 
animal, 24. 
changes of, 42. 
elements of, 22. 
Ear, 125. 
bones of the, 127. 
care of, 127. 
drum of the, 126. 
external, 125. 
foreign bodies in the, 127. 
internal, 126. 
middle, 12&. 
wax of, 127. 
Earache, 14. 
Ear-wax, 127. 
Eating, 21. 
Eat, what we, 21. 
Eggs, 23, 24. 
Elbow, bending of, 86. 
Emergencies, 64, 65. 
Emotion, 100. 
affects the nerves, 116. 
Enamel of the teeth, 27. 
Envy, 116. 
Epidermis, 92. 
Epiglottis, 31, WHERE TO FIND THINGS. 
173 
Foods, kinds of, 22. 
mixture of, 25. 
necessity for, 18. 
source of, 22, 
special, 24. 
vegetable, 24. 
Foot, 15. 
arch of, 84, 87. 
care of, 84, 88. 
Freckles, 93 
Fruits, 25. 
benefits of, 25. 
ripe, 25. 
unripe, 25. 
Full bath, 99. 
Function, 4. 
Furs, 101. 
Hair, grayness of, 100. 
shedding of, 99. 
structure of, 99. 
sudden change of color, 100. 
thinning of, 100. 
uses of, 99. 
Hair-follicles, 94. 
Harmony of bodily organs, 107. 
Headache, 14. 
Health, importance of, 15. 
Hearing, sense of, 125. 
may be cultivated, 125. 
protection of, 127. 
Heart, 46. 
affected by alcohol, 117. 
affected by tobacco, 118. 
cavities of, 48. 
circulation through the, 59. 
frequency of action, 60. 
movements of, 48. 
structure of, 48. 
valves of, 48. 
work of, 46, 60. 
Heat, animal, 23, 37. 
foods productive of, 23. 
regulation of, 101. 
Hiccough, 113. 
High heels, 85, 103. 
Hollow muscles, 68. 
Homes, 135. 
Humerus, 83. 
Humor, aqueous, 130. 
crystalline lens, 130. 
vitreous, 130. 
Hunger, 43. 
Hygiene, 5. 
of the bones, 88. 
of the circulation, 62. 
of digestion, 43. 
of mastication, 32. 
of the muscles, 72. 
of the nerves, xxB. 
of the organs of special sense, 133. 
of respiration, 55. 
of the skin, 103. 
Ganglions, m. 
Gas, sewer, 55. 
Gastric juice, 36. 
action of, 36. 
effect of alcohol upon, 37. 
Gelatine, 23. 
Geography, 22. 
Glands, perspiratory, 94. 
salivary, 29. 
sebaceous, 94. 
tear, 128. 
Glasses, 131. 
concave, 131. 
convex, 131. 
Glottis, 132. 
Gluten, 22. 
Goldsmith’s “Deserted Village,” 
135- 
Graham flour, 24. 
Grief, 116, 128, 
Gristle, 80. 
Growth of brain and mind, 115,118. 
Gum, chewing, 30. 
Gums, vegetable, 23. 
Gustatory nerves, 123. 
Gymnastics, 74. 
Habit, 114, 118, 120. 
Fland, the, 15- 
Hair, 91, 92, 99. 
care of, 99, 104. 
Ideas, 122. 
111-temper, 116. 
Impurities on the skin, 97. 174 
WHERE TO FIND THINGS. 
Incentives to study, 5. 
Inferior vena cava, 48. 
Inheritance, 118. 
Ingrowing-nails, 85. 
Insanity, drunkenness a form of, 
121. 
Insensibility caused by tobacco,! 18. 
Insensible perspiration, 95. 
Inspiration, 52. 
Intercostal muscles, 51. 
Intestinal juices, 38. 
action of, 38. 
Intestinal digestion, 38. 
Intestines, 38. 
motion of, 38. 
structure of, 38. 
Involuntary muscles, 69. 
Iris, 68, 130. 
function of, 131. 
Iron, 23. 
Lens, crystalline, 130. 
Ligaments, 68. 
Light, theory of, 127. 
action on eye, 128, 131. 
need of, 128. 
Limbs, 15. 
Lime in the bones, 88. 
Linen,lol. 
Liver, 40. 
alcohol in, 41. 
secretion of the, 40. 
Lobes of lungs, 49, 50. 
Lobsters, 24. 
Long-sight, 131. 
Looks, importance of, 14. 
Lungs, 49. 
action in, 52. 
structure of, 50. 
Lymph, 96. 
vessels, 96. 
Jaundice, 40. 
Jaw, lower, 81, 86. 
Joints, 15. 
ball-and-socket, 16. 
compound, 16. 
hinge, 16. 
motion in, 16, 
pivot, 83. 
Juice, gastric, 36, 43. 
intestinal, 38, 42. 
pancreatic, 39, 40, 43. 
Jumping, 87. 
Macaroni, 33. 
Manufacturing, 22. 
Marie Antoinette, 100. 
Marrow of the bones, 78. 
Masseter, 86. 
Mastication, 25, 
hygienic laws of, 32. 
importance of, 30. 
Meanness, xi 6. 
Meats, 23. 
the cooking of, 24. 
Medulla oblongata, 111. 
function of the, 113. 
Melons, 25. 
Membrane of the tympanum, 126. 
Microscope, 108. 
Milk, 24. 
mixed with lime-water, 25. 
Mind, effects of alcohol upon, 117. 
growth of, Ixs, xxg. 
Minerals, 23. 
More, Sir Thomas, xco. 
Morning-bath, 98. 
Motion necessary to life, C 6. 
Mucous coat, 36. 
membrane, 145. 
Muriatic acid, 79, Bg. 
Muscles, 67. 
Kidneys, 95. 
Kissing, sometimes dangerous, 96. 
Knee, 16. 
Lacteals, 41. 
absorption by, 41. 
Lamb, 24. 
Large intestines, 38. 
Larynx, 50. 
production of the voice in the, 
132. 
Layers of the skin, 92. 
Leaping, 87. 
Legs, 15, 84, 88. 
Legislative action, 3. WHERE TO FIND THINGS. 
Muscles, antagonistic, 69, 87. 
extensors, 69. 
flexors, 69. 
function of, 67, 85. 
hollow, 68. 
hygiene of, 72. 
in pairs, 69. 
need rest, 71, 73. 
of the eye, 87, 130. 
structure of, 67. 
voluntary and involuntary, 69. 
Muscular contraction, 68. 
Muscular coat, 36, 38. 
fibers, 67. 
sense, 122. 
Music, 122, 125, 135. 
Nurture, 21, 58. 
Nutrition, 60. 
Odors, 122, 124, 135. 
Oil as food, 23. 
Oil-glands, 94, 96. 
Old-sight, 131. 
Olfactory nerve, 124. 
Optic nerve, 128. 
Oranges, 25. 
Organs of circulation, 46, 59. 
of digestion, 35, 38, 39. 
of hearing, 125. 
of respiration, 49. 
of sight, 128. 
of smell, 124. 
of taste, 123. 
of touch, 122. 
of voice, 132. 
Orris-root, 29. 
Overshoes, 102. 
Oxygen, 46, 52. 
continually supplied to the at- 
mosphere, 52. 
given off by plants, 52. 
received into the blood, 52. 
Oysters as food, 24, 33. 
Nails, 92. 
ingrowing, 85. 
uses of the, 92, 105. 
Narcotic, 30, 75. 
property of, 30. 
tobacco a, 30. 
Nasal cavities, 51. 
Nerve-action, Ix 2. 
direct, 112. 
reflex, 112. 
Nerve-matter, io3. 
cells, xoB. 
fibers, 108. 
Nerves, 107. 
affected by alcohol, 116. 
affected by emotion, 116. 
affected by tobacco, 117. 
auditory, 125. 
exercise of, 115. 
functions of, ill. 
gustatory, 123. 
how distributed, 107, 111. 
hygiene of, 118. 
motor, 112. 
olfactory, 124. 
optic, 128. 
sensory, 112. 
spinal, ill. 
structure of, 108. 
sympathetic system of, m, 114 
Nervous system, 107. 
Nose, 17, 52, 124. 
Pairs of parts of the body, 17. 
Palate, 132. 
Paleness, 96. 
Pancreas, 39. 
Pancreatic juice, 39, 43. 
uses of, 40. 
Papillae, 94. 
Paralysis, 116. 
Passages, air, 50. 
Passions, 117. 
Patella, 84. 
Peaches, 25. 
Peas, 23, 24. 
Pelvis, 82. 
Perfumery, 133. 
Pericardium, 47. 
Periosteum, 79- 
Perspiration, 94. 
daily amount of, 95. 
sensible and insensible, 95. 
uses of, 95. 176 
WHERE TO FIND THINGS. 
Pharynx, 31. 
Physical strength, 71. 
culture, 73, 74. 
Piano-playing, 115. 
Pigment, 92, gg. 
Pitch of sound, 132. 
Plantigrade, 19. 
Plays, 74, 75, 121. 
Pleura, 51. 
Pneumonia, 53, 103. 
Pork, 24. 
Portal vein, 41. 
Posture, 73. 
Potash, 23. 
Potato, 23. 
Preservation of the teeth, 28, 32. 
Prism, 128. 
Proteids, 23. 
Pulmonary action, 48. 
Pulmonary heart, 48, 
Pulmonary vein, 53. 
Pulsation of the heart, 60. 
of the arteries, 60. 
Pulse, 60. 
Pupil, the, 130. 
Pylorus, 36. 
Roof of mouth, 132. 
Round shoulders, 75. 
Sago, 23. 
Saliva, 29. 
amount needed, 30. 
flow of, 29. 
secretion of, 29. 
use of, 29, 36. 
waste of, 30. 
Salivary glands, 29. 
Salt, common, 22, 23. 
Saltness, 123, 
Sartorius muscle, 87. 
Scalp, 92, 100, 104. 
Scapula, 83. 
Scarf-skin, 92. 
Sclerotic coat of the eyeball, 129. 
Screaming, 133. 
Sebaceous glands, 94. 
secretion of, 94. 
Selfishness, 116. 
Sensation, 122. 
of temperature, 122, 
of weight, 122. 
production of, 122. 
Sense of hearing, 125. 
of sight, 127. 
of smell, 124. 
of taste, 122. 
of touch, 122. 
Sense, muscular, 122. 
Senses, special, 122. 
Sensory nerves, 112, rig. 
Serous coat, 36. 
Serum, 36. 
Shocks, how distributed, 84, 87. 
Shoes, 84, 101, 103. 
Short-sight, 131. 
Shoulder-blade, 83. 
Shoulders, round, 75. 
Sight, sense of, 127. 
organs of, 128. 
Silk, 101. 
Sir Thomas More, 100. 
Sitting, 73. 
Skeleton, 80, 81, 82, 83, 84, 85. 
Skill, 115. 
Skin, 92. 
Radius, 84. 
Raspberries, 25. 
Redness caused by drink, Xi 6. 
Reflex action of the spinal cord, 
XI2. 
objects of, 113. 
uses of, 113. 
Repair, 58. 
of muscles, 70, 71. 
Respiration, 52. 
change of blood in, 52. 
hygiene of, 55. 
movements of, 51* 
object of, 46. 
organs of, 49. 
Rest, necessity for, 116, 119. 
Retina, 129. 
image on, 131. 
Ribs, 82. 
movements of, in respiration, 
51- 
Rice, 22. WHERE TO FIND THINGS. 
177 
Skin, absorption by, 91, 96. 
care of, 97. 
casts out waste matter, 91, 94. 
how kept soft, 94. 
hygiene of, 103. 
layers of, 92. 
regulates heat, gx, 95. 
rubbing of, 98, 103. 
should be kept clean, 96, 97. 
structure of, 92. 
Skull, 80. 
sutures of the, 81. 
uses of the, 80, 85. 
Slaughter-house, 135. 
Sleep, necessity for, 116, ug. 
Small intestines, 38. 
Smell, sense of, 124. 
nerve of, 124. 
uses of, 124. 
Smoking, effects of, 54. 
cigarette, 54. 
Sneezing, Ix 3. 
Soap, 98, 99. 
Soda, 23, 44. 
Softening of the brain, 116. 
Soles of the feet, 92, 94. 
Something to find out, 19, 32, 44, 
56. 63, 75, 89, 105, 120, 134. 
Sound, production of, 125, 132. 
pitch of, 125. 
Soups, 24. 
preparation of, 24. 
Sourness, 123. 
Spasms caused by tobacco, IxB. 
Special senses, 122. 
Speech, 125, 132. 
organs of, 132. 
production of, X 32. 
Spinal column, 82. 
Spinal cord, 82, in. 
functions of the, 113. 
nerves of, in. 
reflex action of, 112. 
Spine, curvature of, 89. 
Spleen, 39, 149. 
Sponge-bath, 98. 
Starch, 23. 
its change into sugar, 36, 42. 
Sternum, 83. 
Stimulants, 75. 
Stomach, 35. 
absorption in, 37, 41. 
alcohol in, 37. 
digestion in, 36. 
movements of, 36. 
secretion of, 36. 
structure of, 36. 
Strawberries, 25. 
Strength, 71. 
Striated muscles, 67. 
Study, 110, 112, 118. 
Subclavian vein, 42. 
Sugar, 22. 
Sulkiness, 116. 
Superior vena cava, 48. 
Sutures, 81. 
Swallowing, 29. 
Sweat-glands, number of, 94, 95. 
Sweet-bread, in animals, 40. 
Sweetmeats, 43. 
Sweetness, 123. 
Swell of muscles, CB. 
Swine, 124. 
Sympathetic system of nerves, 111, 
114. 
Systemic heart, 48. 
Tainted food, 124, 
Tan, 93. 
Tannery, 135. 
Tapioca, 23. 
Tartar, 29. 
Taste, 122, 123. 
as a sentinel, 122. 
injury of, X 33. 
organ of, 123. 
sense of, 122. 
Tea, 22. 
Tear-gland, 128. 
Tears, 128. 
escape of the, 128. 
secretion of, 128. 
Teeth, 26, 132. 
arrangement of, 26. 
bicuspids, 26. 
canine, or cuspids, 26. 
incisors, 26. 
molars, 26. 178 
WHERE TO FIND THINGS. 
Teeth, of different animals, 26. 
permanent, 34. 
preservation of, 28, 32. 
structure of, 27. 
Temperature of the body, 95. 
extremes of, 96, 101. 
sensations of, 122. 
Tendons, 68. 
Thinking, IxB. 
Thirst, 96. 
Thoracic duct, 42, 
Thorax, 83. 
Thought, 118. 
Throat-deafness, 126. 
Tibia, 84. 
Tight clothing, 103. 
Tight shoes, 84. 
Tissue, connective, 67. 
Tobacco, 30. 
effects upon the body, 54. 
effects upon the breath, 31, 55. 
effects upon the heart, Ix 7. 
effects upon the lungs, 54, 57. 
effects upon the mind, 54. 
effects upon the nerves, 117, 
118. 
effects upon the stomach, 31. 
filthiness of, 31, 55. 
saliva wasted by chewing, 30. 
Tongue, 26, 132. 
nerves of, 123. 
Tooth-brush, 28. 
Tooth-pick, 28. 
Touch, delicacy of, 122. 
organs of, 122. 
sense of, 122, 123. 
Trachea, 50. 
Training, 115. 
Triceps muscle, 86. 
True skin, 93. 
Trunk, 35. 
bones of, 81. 
cavities of, 35. 
Turkey, 24. 
Turnips, 23. 
Tympanum of the ear, 126. 
membrane of, 126. 
Ulna, 84. 
Unconscious movements, 113 
Valves of the heart, 48. 
of the veins, 61. 
Varicose veins, 61. 
Veal, 24. 
Vegetable food, 24. 
respiration, 52. 
Veins, 41, 42, 48, 59. 
circulation in, 61. 
distribution of, 59. 
structure of, 59. 
valves of, 61. 
varicose, 61. 
Venous blood, 46. 
changes of, in respiration, 52. 
Ventilation, 54, 57. 
Ventricles of the heart, 48. 
Vertebrae, 82. 
Vibration, 125, 126. 
Vitreous humor, 130. 
Vocal cords, 132. 
action of, 132. 
Voice, 132. 
care of, 133, 134. 
organs of, 132. 
production of, 132. 
varieties of, 133, 136. 
Voluntary muscles, 69. 
Walking, 85. 
as a means of exercise, 76. 
Waste, 58, 91, 94, 95. 
Water, 23, 95. • 
Water-proofs, 102. 
Weeping, 128. 
Wheat, 22. 
Wheat-flour, 22. 
Whisky, 37, 57, 118, 
Will, impairment of, 117. 
Windpipe, 50. 
Wine, 37. 
Winking, 128. 
Woolens, 101. 
Words, 132, 
Worry affects the hair, 100. THE PHYSIOLOGY FOR THE TIME. 
HOW we Live ; or, the Human Body, and How to Take Care of It. An 
Elementary Course in Anatomy, Physiology, and Hygiene. By 
James Johonnot, author of “ Principles and Practice of Teaching,” 
“ Geographical Reader,” “Natural History Reader,” etc., and Eugene 
Bouton, Ph. D. 
Thoroughly adapted to elementary instruction in the public schools ; 
giving special attention to the laws of Hygiene (including the effects of 
alcohol and narcotics on the human system) as ascertained from a care- 
ful study of Anatomy and Physiology; containing also a full Glossary of 
Terms, complete Index, etc. 
FOR HIGH SCHOOLS, ACADEMIES, AND ALL 
SCHOOLS OF SIMILAR GRADE. 
The Essentials of Anatomy, Physiology, and Hygiene. 
By Roger S. Tract, M. D., Sanitary Inspector of the New York 
City Health Department. 
This work has been prepared in response to the demand for a 
thoroughly scientific and yet practical text-book for schools and academies, 
which shall afford an accurate knowledge of the essential facts of Anat- 
omy and Physiology, as a scientific basis for the study of Hygiene and 
the Laws of Health, the applications of which are clearly and carefully 
stated throughout. It also treats of the physiological effects of alcohol 
and other narcotics, fulfilling all the requirements of recent legislative 
enactments upon this subject. 
Teachers and School-Officers should .correspond with us before intro- 
ducing a new work upon this subject. 
D. APPLETON & CO., Publishers, 
NEW YORK. BOSTON, CHICAGO, SAN FRANCISCO. APPLETONS’ INSTRUCTIVE READING-BOOKS. 
NATURAL HISTORY SERIES. 
Professor JAMES JOHONNOT, 
Author of “ Principles and Practice of Teaching,” “ Geographical Reader,” 
“How we Live,” etc. 
No. 1. 
Book of Cats and Dogs, and other Friends. For Little Folks. 
Friends in Feathers and Fur, and other Neighbors. For 
No. 2. 
Young Folks. 
Neighbors with Wings and Fins, and some Others. For 
No. 3. 
Boys and Girls. 
Neighbors with Claws and Hoofs, and their Kin. For 
No. 4. 
Young People. 
Glimpses of the Animate World: Science and Literature 
of Natural History. For School or Home. 
No. E. 
The publication of “ Appletons’ Instructive Reading-Books ” marks a 
distinct and important advance in the adaptation of special knowledge 
and general literature to the intelligent comprehension of pupils of ail 
grades of attainment. The importance of this movement and its value 
to the present generation of school-children can not be overestimated. 
The Natural History Series contains a full course of graded lessons 
for reading upon topics and in a style that are of the most fascinating 
interest to children and young people, while training them to habits of 
observation, and storing their minds with useful information. 
D. APPLETON & CO., Publishers, 
NEW YORK, BOSTON, CHICAGO, SAN FRANCISCO.