Young Folks’ Physiology. 
OUR BODIES. 
/ 
AND 
HOW WE LIVE: 
AN ELEMENTARY TEXT-BOOK OF PHYSIOLOGY AND 
HYGIENE, FOR USE IN THE COMMON SCHOOLS, 
WITH SPECIAL REFERENCE TO THE EFFECTS 
OF STIMULANTS AND NARCOTICS ON 
THE HUMAN SYSTEM. 
BY 
ALBERT F. BLAISDELL, M.D., 
AUTHOR OF “HOW TO KEEP WELL.” 
Cloth. Illustrated. Price 60 cents net. 
LEE AND SHEPARD, Publishers, 
BOSTON. Physiology for the Young 
OUR BODIES 
OR 
HOW WE LIVE 
AN ELEMENTARY TEXT-BOOK OF PHYSIOLOGY AND HYGIENE 
FOR USE IN THE COMMON SCHOOLS, WITH SPECIAL 
REFERENCE TO THE EFFECTS OF STIMULANTS 
AND NARCOTICS ON THE HUMAN SYSTEM 
BY 
ALBERT F. BLAISDELL, M.D. 
“WE LEARN TO LIVE BY LIVING TO LEARN" 
BOSTON 
D SHEPARD, p"tH4f^RRS 
NEW YORK 
(WAR L E S T. DILLINGHAM 
*<U l88S Copyright, 1884, 
By LEE AND SHEPARD. 
All rights reserved. PREFACE. 
It has been my aim in making this little book, to present 
clearly, concisely, and in a logical order, the most important facts 
about the build and health of our bodies. To keep any machine 
in good running-order, we must know something of the structure 
and use of its various parts. So in the study of that wonderful 
and complex machine, the human body, — “ the house in which 
we live,” — we must build a sure foundation upon its anatomy 
and physiology if we would understand its health. To this end, 
prominence has been given to such facts of anatomy and physi- 
ology as are essential to a proper understanding of the laws of 
hygiene, keeping in mind that the prime object of studying “physi- 
ology ” is to teach us how to keep well and strong. Hence, spe- 
cial emphasis has been laid upon the practical bearing of this 
branch of science upon our daily life and our personal health. As 
far as possible, each paragraph is complete in itself, and discusses 
a definite subject. No more scientific terms are used than are 
really necessary to make the text plain. 
While it is all well and good to know what a book says about 
the various structures of our body, it is not the. whole story. 
Actual observation and actual experiment are as necessary for the 
sound learning of even elementary physiology as for any other 
III IV 
PREFACE. 
branch of science. We must handle the skeleton itself if we 
would know thoroughly all its bones. We must look at a drop 
of blood under the microscope if we would get a good idea of the 
real appearance of blood. Hence, to the description and expla- 
nation of the text, has been added a systematic series of practical 
and suggestive experiments. Most of them are simple, and 
require only a little painstaking and inexpensive apparatus to 
do successfully. It is to be hoped they will be actually done, 
and not simply read as a part of the text. There is no reason 
why physiology should be called a dry and tiresome study, 
especially if it is studied from the stand-point of every-day health 
and practical experiments, which has been outlined in this book. 
In discussing the subject of stimulants and narcotics, only such 
points of their physiological action have been touched upon as are 
generally accepted by standard writers, and such as are of impor- 
tance to pupils for whom this book has been written. 
It has been my aim to be concise and practical, and to make 
every thing plain by using a somewhat simple and homely style of 
writing; in short, to make a working handbook which will be 
of every-day service to pupils in the common schools, and give 
them a suggestive and useful guide to more extended studies. 
Thanks are due to Dr. George F. Keene for many acceptable 
suggestions made during the preparation of this book. 
ALBERT F. BLAISDELL. 
Providence, R.I., November, 1884. CONTENTS. 
CHAPTER I. 
PAGE 
Introduction i 
CHAPTER II. 
The Bony Framework n 
CHAPTER III. 
The Muscles 36 
CHAPTER IV. 
Food and Drink . 51 
CHAPTER V. 
Digestion 65 
CHAPTER VI. 
The Blood and its Circulation 92 
CHAPTER VII. 
Breathing 109 
V VI 
CONTENTS. 
CHAPTER VIII. 
PAGE 
The Skin 125 
CHAPTER IX. 
The Nervous System 140 
CHAPTER X. 
The Special Senses . 169 
CHAPTER XI. 
Excretion 192 
CHAPTER XII. 
The Throat and Voice 199 
CHAPTER XIII. 
Simple Matters of Every-day Health 205 
CHAPTER XIV. 
Practical Experiments 231 
Glossary 265 
Index 279 OUR BODIES. 
CHAPTER I. 
INTRODUCTION. 
1. Animal Life.—We need not be told that we have 
bodies made of flesh and bone, whose substance we see 
and handle every day of our life. Even a child knows 
that certain parts of his body, as the walls of his chest, 
and his heart that he feels beating within it, are always 
moving of themselves. We can move of our own free 
will from one place to another. The wind may rustle the 
leaves, and a breeze may sway a strong oak ; but the leaves 
and the oak have no power to move of themselves. We 
need not wait, like the trees of the forest, for the wind to 
blow us to and fro, or, like the pebbles by the roadside, 
for some one to stir us. Like the horse, dog, bird, or any 
other animal that has life, we can move from place to 
place. Every living animal, then, from ourselves down 
to the tiniest creature that lives its brief life in a single 
day, and that cannot be seen without the aid of the micro- 
scope, has the power to move of itself. 
Again, every child must see for himself that he is warm. 
Even in the coldest day of midwinter, let the stones and 
trees be as cold as the winter wind, our bodies, except 
perhaps the tips of the fingers and toes, are always warm. 
The horse, dog, and even the birds and the bees, are 2 
OUR BODIES. 
warm. All animals, in fact, are more or less warm as 
long as they are alive. 
2. The Body compared to a Locomotive. — Our bodies 
are in some respects very much like the locomotive. The 
bones and muscles answer to the machinery of the engine, 
and the motive-power is produced by the food we eat. 
We put fuel into the furnace. The water in the boiler is 
heated, and expands into steam. Then the piston begins 
to work to and fro; this moves the wheels, joints, and 
levers : and so the whole engine is set going by the fuel 
which is put into the furnace. Now, just the same thing 
occurs in our bodies. We take food, and that food 
passes into the stomach. By reason of that food, we are 
kept warm, muscular force is developed, and the levers 
and joints within us are set working, as we see in the 
locomotive. There is, however, an important difference 
between the two. The locomotive is all the time wear- 
ing itself out. It must be stopped, taken to pieces and 
repaired by the machinist. So our bodies are all the time 
wearing out, but they are constantly repairing themselves. 
We take food, not only to warm us, but also for the build- 
ing-up and repairing of our bodies. Remember, then, that 
the body far surpasses the engine in the perfection of its 
mechanism, inasmuch as it is self-repairing. 
3. The Body and its Nervous System.—Again, if we 
exert our will, or “make up our mind,” as we call it, to 
cross the room, to write with a pen, to pick a flower, to eat 
an apple, or to repeat some familiar maxim, we can do it. 
The mind, or brain, wills to do this or that thing. It 
sends out its order by the tiny, white, thread-like cords 
called nerves; and the muscles are put in motion to do 
whatever the brain has willed them to do. INTRODUCTION. 
3 
Every child must have noticed, that when he pricks his 
fingers with a needle, touches a hot stove, or has eaten 
some unwholesome footl, like an unripe apple, pain is pro- 
duced. These same silvery-white cords, like telegraph- 
wires, carry special despatches to the central station ; that 
is, the brain : and the feeling of pain is there made knoWn. 
This is the way every part of our bodies is watched over 
and protected. If it were not so, we should be continually 
hurting ourselves. This mind, which feels and thinks, but 
which we cannot see, forms the essential part of our being. 
It is the power to feel, to know, to think, to reason, and 
to will, that makes us what we are. Our bodies are ever 
busy. We eat, drink, and sleep. We move about, and 
are warm. We feel, hear, see, talk, breathe, and think. 
We do not wonder about it, simply because it is so com- 
mon. Tut, when we do stop to think about it, how won- 
derful it is simply to be alive ! What study could be more 
important, interesting, and even fascinating, than that 
which has to do with the working of our own bodies ! We 
gaze with wonder and admiration at the marvellous work 
of some intricate machine made by man. Well we may, 
for it seems endowed with life. But, in the human body, 
we find, the more we study and think about it, not simply 
a most perfect and delicate machine, but one endowed 
with life, — a mind — a soul. Indeed, the more we study, 
and the longer we live, and reflect upon it, the more we 
shall realize the great fact that the All-wise Creator, in his 
goodness and wisdom, has made for us bodies, which, in 
the words of the Psalmist, are “fearfully and wonderfully 
made.” 
4. Anatomy, Physiology, and Hygiene.—Before we can 
tell how plants and animals live, we must know what ani- 4 
OUR BODIES. 
mals and plants arc. A watchmaker would be unable to 
describe the working of a watch or clock unless he first 
made himself acquainted with the various parts of which 
watches and clocks are made. So it is with the study of 
human beings. We must know the structure of their 
bodies before we can understand the manner in which 
these bodies act and move, or, in one word, live. 
The science which tells us about the structure, form, 
and position of the different parts of the body, is called 
anatomy. It tells us what they are, where they are, and 
how they look. The word “anatomy” comes from the 
Greek, meaning “a cutting through,” or dissection; that 
is, the act of cutting an animal in pieces for the purpose 
of study. 
The science which explains the uses or functions of the 
different parts of the body is called physiology, meaning 
“a story about nature.” 
Now, after we have learned something about the struc- 
ture and uses of different parts of the body, it is needful 
to learn how to take care of these parts, and how to keep 
them in health. We do this by the study of hygiene, or 
the science which tells us about health. The word 
“hygiene ” is derived from the name of the Greek goddess 
Mygeia, who is said to have watched over the health of 
the people. 
Take the stomach for an illustration. If we learn what 
it is, where it is, how it looks, its shape, size, and general 
appearance, its coats, etc., this would be its anatomy. 
Going on from this point, if we learn for what special pur- 
pose it is made, just what these different parts do, and 
how they do it, this would be its physiology. Finally, if 
we learn what might interfere with the proper working of INTRODUCTION. 
5 
each part, and how it is kept in good order,—what will 
injure its health, and what will do it good, —this would be 
its hygiene. 
It will, perhaps, be well at this point to explain certain 
words which will be constantly occurring in the succeed- 
ing pages. - 
5. Tissues and Organs. —A tissue is the simplest form 
in which any part of the body can exist without entirely 
losing its distinctive character. We thus speak of bony 
tissue, muscular tissue, fatty tissue, and so on. The total 
number of tissues is not great. Each tissue has certain 
features about it which mark it wherever in the body it 
may be found. They may be compared to the brick, stone, 
wood, iron, mortar, glass, and other materials, which, prop- 
erly arranged, make up a dwelling-house. 
Any part of the body which does a special work is called 
an organ. It is simply several tissues working together 
as a whole, and specially fitted to do a particular thing. 
Thus, the eye is the organ of sight, the nose of smell, the 
ear of hearing, the stomach of digestion, and so on. If. 
there are a number of similar organs scattered through 
the body, but of different size and shape, we call them a 
system. Thus, we speak of the arterial system, the ner- 
vous system, and so on. The special work which an organ 
has to do, is said to be the function, or use, of that organ : 
thus, it is the function of the eye to see, and of the 
stomach to digest food. 
6. Minute Structure of the Body. — If, now, we exam- 
ine under a microscope any tissue of the body, we shall 
find it is mainly made up of a countless number of minute 
solid particles called cells. They are so small that we 
must use a powerful microscope to see them at all. The 6 
OUR BODIES. 
cell is the original element out of which every tissue and 
part of the body is formed. In a general way we may 
compare these cells to the tiniest bags filled with a semi- 
fluid mass, in which another still smaller bag floats, and 
is called the nucleus of the larger one (Figs, i and 2). 
Fig. i. — Two cells of round or oval 
form: a, a, border of the cell; b, b, 
cell-body; c, c, nuclei, with nucleoli, 
a, d. 
Fig. 2. — a, columnar epithelial cells; b, spin- 
dle-shaped connective tissue-cells; c, star- 
like cell from lymphatic gland. 
Cells are of all shapes and sizes (though all are very 
small), round, flat, thick, and long. Thus, we shall learn 
in a succeeding chapter of the rounded cells, or corpuscles, 
which float in the blood, and of the flattened cells which 
can be scraped from the outer or scarf skin. 
The life of a cell is one of ceaseless change. It is ever 
changing its form. If we watch the cells under a micro- 
scope, we find them dividing themselves into parts with 
the greatest rapidity. In their never-ending changes, they 
are doing a remarkable work in our bodies. Some change 
their forms, and become muscle : others become fluids, 
which help digest our food. The liver-cells manufacture 
or secrete the bile, and the bone-cells help make the 
bones. Millions of blood-cells do their work and perish 
every day, while the brain-cells act in some mysterious 
way to help us think. In short, our very life exists in 
the cell. 
7. Elements found in the Body. — Now, if we put aside nvTRonucnoN. 
7 
the microscope, and call upon the chemist to help us, he 
will tell us that there are about seventy different ele- 
ments known to chemistry. Of these, only sixteen exist 
in our bodies. The most important are carbon, hydrogen, 
nitrogen, oxygen, sulphur, iron, phosphorus, soda, potash, 
lime, and magnesium. Thus, there is iron in the blood, 
lime in the bones, soda in the bile, and potash in the 
muscles. Very few of these elements exist as such in 
the body. They are mainly found as chemical compounds. 
Thus water, a combination of oxygen and hydrogen, forms 
about two-thirds of the weight of the body; and the aver- 
age human body contains about six ounces of common salt, 
which is a form of soda. 
8. General Build of the Body. — If we look at the human 
body, we cannot help noticing that it is made up of a mid- 
dle, nearly round portion, which is called the trunk. On 
the top of this is placed a kind of round ball, called the 
head; while two pairs of branches, called the extremities, 
are attached to the upper and lower corners of the trunk. 
Again, we notice that the whole body has an outer cover- 
ing, which is called the skin. Underneath the skin lie 
soft masses of red flesh, called the muscles. These muscles 
are mostly fastened to the hard parts, or hones. These 
bones make up the framework of our bodies. There are 
about two hundred separate bones in the body, which 
they serve to support. Taken together, they form the 
skeleton. The limbs are solid ; but the head is hollow, 
and holds an organ called the brain, which is the centre 
of the nervous system. A cheesy-like, silvery-white cord, 
called the spinal cord, runs from the brain down the mid- 
dle of the backbone, and sends its thread-like branches, 
called nerves, all over the body. It is through the ner- 8 
OUR BODIES. 
vous system that we are able to think or feel, or, in fact, 
know any thing. The trunk is also hollow. It is divided 
into an upper and a lower room by means of a partition 
called the diaphragm (Fig. 3). The upper room is called 
Fig. 3. —Contents of the Chest and Abdomen. 
the chest, and holds the heart and the lungs. The lower 
room is called the abdomen, and holds the stomach, liver, 
intestines, and other vital organs. 
9. General Plan of Study. — We shall now proceed to 
study the human body, or “the house in which we live,” 
under the following general topics : — IN TROD UC TION. 
9 
(/) The Skeleton, or bony framework (2) The Muscles, or fleshy parts. 
(3) The Food and Drink. (4) The Digestion of Food. (5) The Blood and 
its Circulation. (6) The Respiration, or Breathing. (7) The Skin, or outer 
covering. (8) The Nervous System and the Brain, (9) The Special Senses. 
(10) Excretion, or getting rid of waste matter. (11) The Throat and the 
Voice. 
The skeleton, or bony framework, consists of about two 
hundred bones of various shapes and sizes. It forms the 
main support of our bodies, and serves to protect the vital 
organs within. 
The muscles are the fleshy or lean parts of the body; and 
they, together with the fat, give to the body its general 
form and proportion. 
Food and drink are the materials necessary to keep up 
the warmth and growth of the body, and enable it to make 
its movements. 
Digestion is the process of changing the food into a con- 
dition suitable for absorption into the blood. 
The blood is the vital fluid of the body. The course 
of the blood through the body is called its circulation. 
Respiration is the act of breathing. It is carried on 
mainly by the lungs. 
The skin is the outer covering of the body. 
The nervous system enables us to move, see, feel, taste, 
and so on. The brain and the spinal cord are its cen- 
tral organs. 
The special senses enable us to touch, taste, smell, hear, 
and see. We often speak of them as the five senses. 
Excretion is the process by which the body gets rid of 
its waste matters, mainly through the lungs, skin, and 
kidneys. 10 
OUR BODIES, 
The voice is produced by the vibration of two little cords, 
or bands, in the top part of the windpipe. 
Each one of these topics will be treated of in the suc- 
ceeding chapters of this book, to be followed by a chapter 
on simple matters of every-day health. 
Collateral Reading. —Hooker’s Child's Book of Nature, Part II. 
TEST QUESTIONS FOR REVIEW. 
1. Motion and heat. How may the child get some idea that his body 
moves, and is warm ? 
2. What marked difference is there between all animals and all vege- 
tables ? 
3. How would you compare the body to a locomotive ? 
4. Can-you tell where the comparison fails? 
5. Explain, in a general way, how we are able to cross a room, pick a 
flower, and do many similar acts. 
6. What does the child experience when he touches a hot stove, or 
pricks his finger? What good does pain do? 
7. Why do we wonder at the marvellous actions of our bodies ? 
8. What is meant by anatomy? physiology? hygiene? Illustrate. 
What is an organ ? a tissue ? 
9. What is meant by the function of an organ ? Illustrate. 
10. Of what is the minute structure of the body made up? 
11. Tell what you know about cells. 
12. What elements are found in the body? 
13. What can you say about the general build of the body? 
14. Mention the general topics which will be discussed in this book. THE BONY FRAME WORK. 
11 
CHAPTER II. 
THE BONY FRAMEWORK. 
10. The Skeleton. — Every animal must have some 
kind of a framework or support to give its body form or 
shape. This framework in most animals is a support 
made up of a number of firm and hard substances called 
bones. The bones may be on the outside, like a coat of 
mail, as seen in the lobster and turtle ; or there may be a 
framework of bones inside of the body, moved by muscles 
outside, as seen in the codfish and shad. In fact, all 
animals that belong to the great backbone family have an 
inside framework. This bony support is called the skele- 
ton, meaning a “ dried-up body.” It is to the body what 
the ribs are to a vessel, or what the frame is to a house. 
Every one is familiar with the picture of the human skele- 
ton (Fig. 5). It shows us how the dead bones of the 
human body look when taken out, cleaned, and held by 
wires in their proper places. The human skeleton is made 
up of about two hundred separate bones,* of various sizes 
and shapes. 
* To be move exact, 28 bones are counted in the head, including the three 
bones in each ear, 54 in the trunk, and 124 in the limbs. This number de- 
pends upon the time and how the bones are counted. The 32 teeth are not 
usually reckoned as bones. Several bones, which m youth are made up of 
separate pieces, unite in old age, and make one bone. The breast-bone, for 
instance, in the child, consists of eight pieces; but in adult life it is made up 
of only three. 12 
OUR BODIES. 
The bones of the body thus arranged give firmness, 
strength, and protection to the soft tissues and vital 
organs, and form, as it were, the foundation upon which 
our bodies are securely built. 
11. How Bone is made up. — Bone is a hard and strong 
substance, made up of animal matter united with certain 
mineral earths, as lime and potash. The earthy part of 
bone makes up about two-thirds of its weight, and the 
animal portion the other third. Put a slender chicken- 
bone in a mixture of two ounces of muriatic acid to one 
pint of water, and let it soak for two or three days, and 
the earthy part will be dissolved, leaving only the animal 
matter (Exper. 3).* The form of the bone is kept ; but it 
can be easily bent, cut, torn, or even tied into a knot. 
Again, put a soup-bone into a hot fire, and let it burn for 
two or three hours (Exper. 4). Take it out carefully, and, 
while the shape is still kept, the bone is brittle, and will 
readily crumble when pinched between the fingers. The 
animal part has been burned out, and only the white bone- 
earth is left. The lime gives hardiness and firmness to 
the bones; while the animal substance makes them elastic, 
tough, and flexible. The proportion varies with age. In 
childhood the bones have more animal matter than earthy : 
hence a child’s bones do not break easily, and, when 
broken, soon knit together. In old age, there is more 
lime in the bones than animal matter: hence they are 
brittle, and easily broken. They unite slowly, and some- 
times not at all. 
12. General Structure of the Bones. — If we take a 
* The figures with “ Exper.” throughout this book refer to the number of 
the experiment in chap. xiv. THE BONY FRAMEWORK. 
13 
long bone, like that from a sheep’s leg, or even a part of 
a beef shin-bone, and saw it lengthwise, we see that the 
ends are soft and spongy, while the shaft is hard and com- 
pact (Exper. 1). it is hollow, and the central cavity runs 
almost the whole length of the bone. It is filled, in life, 
with a soft substance called marrow. If the bones were 
solid, they would be much too heavy for ordinary use. A 
bone may be hard as a rock on the outside, on account of 
its thin, dense layer of compact bony tissue, and yet be 
light because of its cavity and the trellis-work of loose, 
spongy texture at the ends. 
Bones, as we all know, are of many different shapes, 
according to the uses to which they are put (Exper. 5). 
Some are long, with hollow shafts, as the bones of the arm 
and leg; others are short, to give strength, as the bones 
of the fingers and toes ; some are flat, for protection, and 
to cover cavities, like the bones of the skull and shoulder- 
blades ; while others are of various odd shapes, and hence 
called irregular, as the bones of the backbone and ankle. 
13. Minute Structure of Bones. — When bones are 
alive or fresh, they have a pinkish-white color, caused by 
the blood which is in and flows through them. Take a 
long, slender bone, like a rib or a sheep’s leg, and we find 
that it is elastic, and will bend. Now, if we scrape down 
on the bone with a sharp knife, we find that it is wrapped 
round with a tough but very thin covering, called the 
periosteum, meaning “about a bone.” All bones are cov- 
ered with periosteum except where they go to form a joint. 
Bones die if this covering is for any cause removed. They 
have a great number of blood-vessels, which, becoming 
very small and hair-like, pass through tiny holes, or tubes, 
in the bones, and bring materials for their nourishment 14 
OUR BODIES. 
and growth (Fig. 4). The tubes through which the blood- 
vessels of the bones travel are called “ Haversian canals,” 
having been discovered by Havers, a learned English doc- 
tor, who lived-some two hundred years ago. They are 
shown with a microscope, largely magnified. Round these 
tubes the bony matter is arranged in layers, and between 
these layers are small cavities called lac mice. These are 
joined to each other, and to the canal which they surround, 
Fig. 4. — Bone: A, longitudinal section, showing the Haversian canals, a, c, d, e, and f, f, 
lacunae and canaliculi. B, transverse section, showing one complete Haversian system, a; 
part of another, b; and an outer lamina, e, e; a is the transverse section of an Haversian 
canal. 
by other extremely fine tubes, called canaliculi, meaning 
the finest of fine canals. As seen under the microscope, 
the appearance is not unlike a small animal with a great 
many legs (Exper. 2). Thus the bones are tunnelled, like 
honey-comb, with passages through which the blood — 
“the river of life” — flows in every direction. 
14. The Head. — The skeleton, or bony framework of 
the “house we live in,” consists of the bones of the head, 
THE HEAD. THE BONY FRAMEWORK 
15 
the trunk, and the extremities. The bones of the head in 
elude those of the cranium and those of the face (Exper. 6). 
Fig. 5. — Skeleton of Man. 
Together they form the strong box of bone commonly 16 
OUR BODIES. 
called the skull. The general shape of the head is that 
of an arch. The arch is the strongest shape in which 
the skull could be made, just as the arched bridge is the 
strongest-shaped bridge which can be made to bear the 
heavy loads that have to pass over it. 
15. The Cranium. — The cranium, or brain-case, is a 
kind of oval, bony shell, which holds and protects the 
brain. It is made up of eight bones closely locked to- 
Fig. 6. — The Skull. 
gather by seams or sutures, somewhat like the dovetailing 
used by carpenters. Let us arrange and describe these 
eight bones thus : — 
One Frontal (forehead), 
Two Parietal (side of head), 
Two Temporal (temples), 
One Occipital (back of head), 
One Sphenoid (“wedge-shaped”), 
One Ethmoid (“ sieve-like ”). 
The frontal bone forms the forehead. It is this bone 
which gives a beauty of form and a dignity of person seen T1IE BONY FRAMEWORK. 
17 
in no other animal in creation. Next are the two bones 
making the sides, or walls, of the head, hence called the 
parietal bones, from a Latin word meaning a wall. They 
join the two temporal bones, which lie round each ear, and 
form the “temples.” The occipital bone forms the lower 
and back part of the skull. This broad, flat bone rests 
on the topmost bone of the backbone, and is pierced by a 
large hole through which a long cord of whitish marrow, 
called the spinal cord, passes from the brain-case into the 
spinal canal, and runs down the whole length of the back- 
bone. The sphenoid or wedge bone is wedged in between 
the bones of the cranium and those of the face, and serves 
to lock together fourteen of these bones. The ethmoid or 
sieve-like bone, so called because it is full of holes, like a 
sieve, lies between the eye-cavities just at the root of the 
nose. The nerves of smell pass through the holes in this 
bone into the cavities of the nose. 
16. The Face. — All the bones of the /ace, except the 
lower jaw-bone, are firmly fixed to each other, and to the 
bones of the cranium. By their union, these bones form 
five cavities ; namely, the two large cup-like cavities called 
the orbits, the two nostrils, and the mouth. The orbits 
are hollow, bony sockets in which the eyes are placed. 
In the back part of each cavity is a crevice through which 
the nerve of sight (optic nerve) passes from the brain 
to the eye. 
The face contains fourteen bones ; viz., — 
Two Malar (or cheek) bones, 
Two Nasal (or nose) bones, 
Two Upper Jaw-bones (upper max- 
illary), 
One Lower Jaw-bone (lower maxil- 
Jary), 
Two Palate bones, 
Two Lachrymal bones, 
One Vomer (ploughshare) bone, 
Two Turbinated (spongy) bones 18 
OUR BODIES. 
Under the orbits, and overlapping the jaw-bones, we 
find the two malar or cheek bones, which in some races, 
as the American Indians, are very prominent. The two 
bones that form the upper part, or bridge, of the nose, are 
called nasal bones. The lower part of the nose is gristle, 
and not bone. Next we come to the two upper jaw-bones, 
containing, as we all know, some of our teeth. The rest 
of the teeth are fixed in the lower jaw-bone, which moves 
by means of a hinge-joint, so as to allow the opening and 
shutting of the mouth. 
The remaining bones of the face are small. Two bones, 
forming the back part of the roof of the mouth, are called 
the palate bones. Two little bones, partly forming the 
inside walls of the eye-cavities, are called the lachrymal 
bones, from a Latin word meaning a tear. There is, 
through each of them, a canal which carries the tears from 
the eyes to the nose. The vomer or ploughshare bone (so 
called from its resemblance to the share of the farmer’s 
plough) is situated between the nostrils. Two delicate 
little bones within the nose-cavity, shaped like a scroll 
or horn, are called turbinated bones, from a Latin word 
meaning a whirl. 
17. How the Bones of the Head are joined together. — 
The bones of the head are joined together in a peculiar 
way (Exper. 7). The edges of the bones of the cranium 
and face are shaped somewhat like the teeth of a saw. In 
adults, these edges fit into each other, and grow together, 
resembling the dovetailed joints in a cabinet-maker’s work : 
hence they are called sutures, from a Latin word which 
means a sewing or a seam. In infancy the bones of the 
skull do not meet, and the throbbing of the brain at 
the top of the head is easily seen. These openings are THE BO IVY FRAMEWORK. 
19 
called foutanelles, “little fountains.” The bones of the 
skull are not wholly welded together till the child reaches 
adult life. When the bones are knitted together, these 
sutures add greatly to the strength and resistance of the 
brain-case. 
THE TRUNK. 
18. The Trunk. — The trunk is that part of the body 
which supports the head, and to which the arms and legs 
are attached (Exper. 8). It has two important rooms, or 
cavities. The upper one, called the thorax, or chest, con- 
sists of a bony framework formed by the breast-bone, ribs, 
and backbone. It contains the lungs, with which we 
breathe ; and the heart, which pumps the blood through 
the body. The lower part, or abdomen, holds the stomach, 
liver, bowels, kidneys, and other important organs. Between 
the chest and abdomen is stretched a broad muscle, which 
moves up and down as we breathe. This is called the 
“midriff” by the butchers, or diaphragm, from a word 
meaning a fence or a partition. 
The principal bones of the trunk consist of those of the 
spine, ribs, and the hips. 
There are fifty-four bones in the trunk, and they arc 
thus arranged : — 
I. The Spine contains 26 sepa- 
rate bones 
7 Cervical (or neck) Vertebrae 
12 Dorsal (or back) Vertebrae. 
5 Lumbar (loins) Vertebrae. 
I Sacrum, or sacred bone. 
I Coccyx, or cuckoo-bone. 
II. The Ribs, 24 bones . . . 
7 True Ribs. 
3 False Ribs. 
2 Floating Ribs. 
TIL I Sternum, or breast-bone. 
IV. The 2 Hip-bones, 
y. The Hyoid bone. 20 
OUR BODIES. 
19. The Spine. — The spine, or backbone, serves as a 
support for the whole body. It is made up 
of a number of separate bones called ver- 
tebra, between which are placed pads, or 
cushions, of gristle (Fig. 7). These cush- 
ions are elastic* or springy, yet thick and 
strong. They serve to break the force of 
any shock or injury which the spine may 
receive, just as the springs of a carriage 
lessen the jolting which would be felt with- 
out them. These soft pads also prevent 
any grating or friction of one bone on 
another. They are also yielding ; that is, 
are readily pressed together, else the back- 
bone could not bend.f 
The spine is really a pile of twenty-four 
separate bones, resting on and above a 
strong, three-sided bone called the sacrum, 
or sacred bone, which is wedged in between 
the hip-bones. The sacrum, although reck- 
oned as one bone, actually consists of five 
distinct vertebrae, which grow together, 
however, and form a single bone in adult 
age. Joined to the lower end of the sacrum 
* The elasticity uf these plates of cartilage is so 
great, that we are actually about half an inch shorter 
when we go to bed than we were when we got up in the 
morning, by reason of their flattening out under the 
weight of the erect position. 
t These bones, again, are prevented from yielding too much by strong 
tough straps, or ligaments, which stretch between them. If the separate bones 
were allowed too much freedom of movement, the spinal cord inside the canal 
would be crushed or twisted, and paralysis or death would at once follow. 
Fig. 7. — The Backbone, THE BONY FRAMEWORK. 
21 
is a little, tapering bone called the coccyx, so named from 
its resemblance to the beak of a cuckoo. The whole spine 
forms a pillar, or column, of bones, tapering as it goes up. 
At the top are seven cavical or neck vertebrae : below 
them are the twelve dorsal or back vertebrae, from which 
spring the ribs. The five lowest bones, called the lumbar 
or loin vertebrae, are the thickest and largest. Each ver- 
tebra of the backbone is pierced with a hole through its 
centre ; and the separate bones are so placed one above 
the other, that these holes form a continuous tube, or 
canal, down which passes the spinal cord.* 
In this bony canal the spinal marrow lies protected 
from injury. From each vertebra stick out spines, or 
thorns, of bones, to which are fastened muscles, which 
keep the flexible backbone erect, and lift the head and 
shoulders. The row of spines along the whole length 
of the backbone forms a ridge, which we can feel by 
pressing with the fingers up and down the middle of the 
back. 
The spine is one of the most curious and wonderful 
things in nature, — so firm, and yet so elastic; so stiff 
that it will bear a heavy weight, and yet bending like rub- 
ber; a tapering pile of odd-shaped bones, so admirably 
planned, and so wonderfully put together, that the delicate 
brain resting upon it, and the spinal cord hidden within its 
bony canal, are not often hurt. The most daring athlete 
rarely breaks the bones of his spine, or puts them out of 
place. 
* Imagine a number of spools placed one on another. The central hole 
through each would be exactly over the other, and there would be one long 
tube, or channel, through the whole string of spools. This is just like the 
arrangement of the vertebrae of the backbone. 22 
OUR BODIES. 
How the Skull and Spine are joined together. — The spine and the skull 
are joined in a peculiar manner. The first, or topmost, of the neck vertebrae 
is called the atlas, so called from the fabled Atlas of the ancients. In olden 
times, people believed that the earth was supported on the shoulders of a 
huge giant called Atlas. As, therefore, the head is supported by this bone, it 
received the name of atlas, after the fabled giant of old. On the lower part 
of the skull are two smooth rockers, which fit into two little smooth grooves 
hollowed out in the atlas. We are thus able to rock the head to and fro. 
The second vertebra of’the neck is called the axis, and has a peg, called 
the odontoid process, or tooth-like peg, which fits into a hole in the atlas. 
Thus, when we turn the head sideways, the atlas turns around the peg of the 
axis. 
20. The Ribs. — The ribs are the slender, but strong, 
bony hoops which help make the framework of the chest. 
They pass around the chest, and strengthen it, resembling 
somewhat the hoops of a barrel. There are twenty-four 
ribs,—twelve on each side. They are joined to the back- 
bone behind, and in front to a flat, narrow bone, shaped 
somewhat like an ancient sword or dagger, called the 
sternum, or breast-bone. This bone does not go down far 
enough to allow of all the ribs being joined directly to it. 
Only the fourteen upper ribs — that is, seven on each 
side — are thus fastened : they are on this account called 
the true ribs. The next six, three on each side, come 
partly round from the spine, and then each is joined by 
gristle to tbe one above it. They are called the false ribs. 
The remaining four ribs, two on each side, spring from the 
spine, like their neighbors, but are not fastened to any 
thing in front, and for this reason are called the floating 
ribs. The spaces between the ribs are filled with strong 
muscles, one set of which raises the ribs, the other lowers 
them. This barrel-shaped framework of bones that makes 
the chest, although strong, is not rigid. It can be raised 
and lowered, owing to the joints at the back, tbe carti- THE BONY FRAMEWORK. 
23 
lages, or gristle, in front, and the muscles between. The 
space within thus becomes larger, and more room is 
allowed for the action of the heart and lungs. 
21. The Hips. — T he lower part of the trunk is formed 
by two large, irregular bones, very firm and strong, called 
the hip or haunch bones. They join the sacrum behind, 
and each other in front. The two hip-bones, with the 
Fig. 8. — The Pelvis. 
sacrum and coccyx, form a kind of bony basin called the 
pelvis, in which many important organs are held (Fig. 8). 
Each hip-bone has a deep, cup-shaped cavity, or socket, 
into which the rounded head of the thigh-bone fits. 
Note. Under the lower jaw is a little horseshoe-shaped bone called the 
hyoid bone because it is. shaped like the Greek letter v. The root of the 
tongue is fastened to its bend, and the larynx is hung from it as from a hook. 
The hyoid, like the knee-pan, is not connected with any other bone. 
THE UPPER LIMBS. 
22. The Upper Limbs. — Man has two upper and two 
lower limbs. Each upper limb consists of three parts, the 24 
OUR BODIES. 
upper arm, the fore-arm, and the hand. Each lower limb 
also consists of three parts, — the thigh, the lower leg, and 
the foot. In speaking of the bones of the upper extremi- 
ties, however, it is usual to include the two shoulder- 
blades and the two collar-bones (Exper. 9). Each upper 
limb, therefore, contains the following bones : — 
Scapula, or shoulder-blade. 
Clavicle, or collar-bone. 
Humerus. 
Upper arm 
Fore-arm 
Ulna. 
Radius. 
Hand 
8 Carpal (wrist) bones. 
5 Metacarpal Irenes. 
14 Phalanges, or finger-bones. 
Making thirty-two bones altogether. 
23. The Upper Arm. — There are two bones in the 
shoulder, and they serve to fasten 
the arm to the trunk. These are 
the scapula, ox shoulder-blade (Fig. 
9), and the clavicle, or collar-bone. 
The scapula is a large, flat, three- 
sided bone, which is placed on the 
upper and back part of the chest, 
outside of the ribs. On the outer 
side it has a saucer-like cavity 
called the glenoid cavity, into 
whi'ch the rounded head of the 
arm-bone fits. The clavicle, or col- 
lar-bone, has a double curve, like the Italic letter f It lies 
across the shoulder, like a kind of rigid bar, over and above 
the first rib. It serves, like the keystone of an arch, to 
keep the shoulders apart, and to hold them firm when the 
upper limbs are used. Its inner end is tied to the breast- 
Fig. 9. — Back of Right Scapula. THE BONY FRAMEWORK. 
25 
bone, and its outer to the shoulder-blade. The humerus is 
the long, hollow bone of the upper arm. It fits into the 
soeket of the shoulder-blade, and goes to the elbow, where 
it is joined to the two bones of the fore-arm. 
24. The Fore-arm. — The fore-arm contains two long, 
hollow bones, the ulna and the radius. The ulna is the 
larger of these two bones, and is joined to the humerus 
by a hinge-joint at the elbow. It is prevented from 
moving too far back by a process, or projection, which 
makes the sharp point of the elbow. The radius is the 
long, slightly curved outer bone of the fore-arm. It is 
smaller than the ulna. Its upper end is fastened both to 
the ulna and the humerus. Its lower end is much larger 
than its upper, and carries the hand. The radius is tied 
to the ulna in such a manner that it can glide nearly round 
it. This gives us the power of twisting the fore-arm and 
hand. 
25. The Hand. — The hand consists of three parts, the 
wrist, the palm, and the fingers, containing in all twenty- 
seven bones (Fig. io). There are eight carpal or wrist 
bones, all of which are very closely packed in two rows, 
and bound together with cords. The wrist is thus as 
strong as if made of a single bone, while at the same time 
it is capable of the most delicate movements. The meta- 
carpal bones are the five long bones which form the palm 
of the hand. They are attached to the carpal bones of the 
wrist, and to the bones of the fingers. The phalanges of 
the fingers are the fourteen small bones which are tied 
end to end, to form the fingers. Each finger has three 
bones, each thumb two. The bones of the fingers are 
arranged in three rows, as will be seen by closing the hand. 
The wrist-bones, metacarpal bones, and finger-bones are all 26 
our nonius. 
held in place by strong but flexible ligaments. By this 
beautiful contrivance, the greatest strength and elasticity 
are given to the hand, which is thus fitted for all kinds of 
Fig. io. — Palm of the Right Hand. 
work, from grasping heavy hammers to handling the pen, 
and threading the finest needle. 
THE LOWER LIMBS. 
26. The Lower Limbs. — The general structure and 
number of the bones of the legs bear a striking similarity 
to those of the arms. Thus the leg, like the arm, consists 
of three parts, the thigh, the lower leg, and the foot. There 
is only one bone in the thigh, while there are two in the 
lower leg. We see that this is similar to the arm. In 
the foot, the tarsal or ankle bones correspond with the 
carpal bones of the wrist; while the metatarsal bones and 
the phalanges of the toes take the place of the metacarpal 
bones and the phalanges of the fingers (Exper. 10). THE TONY FRAMEWORK. 
27 
The bones of the leg are, — 
Thigh 
Femur, or thigh-bone. 
Patella, or knee-pan. 
Tibia, or shin-bone. 
Fibula, or splint-bone. 
Lower leg 
Foot . 
7 Tarsal or ankle bones. 
5 Metatarsal or instep bones. 
14 Phalanges, or toc-bones. 
Making thirty bones in all. 
27. The Thigh. — The top bone of the leg is the femur, 
or thigh-bone. It is the largest and strongest bone of the 
body. It has a rounded head, which fits into the cnp-like 
cavity in the hip-bone : this deep socket is called the 
acetabulum, meaning a vinegar-cup. At the knee-joint 
the thigh-bone meets the bones of the lower leg, to which 
it is fastened by strong cords. 
28. The Lower Leg. — The lower leg consists, like the 
fore-arm, of two bones. The larger, a strong, three-sided 
bone, with a sharp edge in front, is called the tibia, and is 
commonly known as the shin-bone. The smaller bone, 
bound at both ends to the tibia, is called the fibula, mean- 
ing a clasp. It is a long, slender bone on the outside of 
the leg, and its lower end forms the outer ankle. It is 
often spoken of as the small bone of the leg. Covering in 
part the knee-joint is a flat, three-sided bone, called the 
patella, or knee-pan, which protects the joint, and gives 
firmness to the leg. 
29. The Foot. — The foot, like the hand, consists of 
three parts, the bones of which are known as the tarsal 
bones, the metatarsal, and the phalanges of the toes 
(Fig. 11). The tarsal or ankle bones are seven in num- 
ber, and form the heel, the ankle, and part of the sole 
of the foot. These seven irregular bones are tied firmly 28 
OUR BODIES. 
together by straps, or ligaments, and are strong enough 
to bear the weight of the body. The large bone, which 
projects backwards, is the heel-bone; and on the bone over 
FIBULA — 
—TIBIA 
7 TARSAL BONES 
FORMING ANKLE 
B metatarsal 
BONES f— - 
—ASTRAGALUS 
-HEEL-BONE 
id PHALANGES 
FORMING TOES 
Fig. ii.— Bones of Foot and Ankle. 
this the shin-bone rests. The heel-bone is connected with 
the great muscles of the calf of the leg by a very strong 
cord, or tendon, called the tendon of Achilles.* 
The metatarsal bones, like the palm of the hand, are five 
in number, and form the instep of the foot. They are 
the connecting link between the ankle-bones and the pha- 
langes of the toes. The bones of the toes, or phalanges, 
*' The warlike deeds of this famous Greek hero were sung by I Tomer. 
According to the story, Achilles received his death-wound in the heel, no 
other part of his body being liable to injury. TIFF. BONY FF A ME WORK. 
29 
number fourteen in all, three in each toe, with the excep- 
tion of the great toe, which, like the thumb, has only two 
bones. 
30. Uses of the Bones. — Bones serve many useful 
purposes. They keep up the general shape of the body. 
The skeleton, as we have seen, is its framework. It gives 
strength and support to the soft and fleshy parts. If 
there were no bones, and the whole body were a mass of 
flesh only, the legs would give way, and finally be crushed 
down, under the great weight of the body. Again, bones 
protect the soft organs which lie beneath them. The 
bones of the head protect the soft and delicate brain in a 
complete box of bone: the ribs protect the heart and 
lungs in a large cage of bone, and so on. Passage-ways 
and little cavities are hollowed out of solid bone to lodge and 
shield important organs. Grooves and canals are formed 
in the hard bone to receive and protect tender organs, 
delicate nerves, and t blood-vessels. Finally, the sur- 
faces of bones are fitted with grooves, knobs, and sharp 
edges, to which muscles are tied. We are thus enabled to 
stand erect, and make with ease and quickness the count- 
less movements of the body. The blood filters through 
bone as freely as it does through any other living tissue. 
The bone-structure is ever changing. Old material is got 
rid of, and new matter takes its place. 
31. Repair of the Bones. — When a bone is broken, 
blood trickles out between the injured parts, and afterward 
gives place to a sticky, watery fluid, which gradually 
becomes thicker, like sirup or jelly. This slowly hardens 
into a new bone-structure, and forms a kind of cement to 
hold together the broken ends. Nature does not spare 
her healing-cement. The excess bulges out round the 30 
OUR HOMES. 
place of union, over which a bunch is felt, for a lifetime 
perhaps, under the skin. In young people, a broken bone 
will knit together in two or three weeks ; while in grown- 
up people six weeks or more will be required. In aged 
persons, a broken bone may cripple them for life. It is 
then a tedious matter, and sometimes the bones will not 
unite at all. After a bone has been once broken, it is 
fragile for some time ; and great care should be taken lest 
it be broken a second time before it firmly unites. When a 
bone is broken, the ends tend “to ride” over each other, 
because the muscles pull the broken portions apart; hence 
the need “to set" the bone by drawing the injured bone 
into place, and keeping it so by splints and bandages, prop- 
erly applied, by a surgeon (Exper. 11). 
32. How Bones are joined together. — The place 
where two bones join together is called a joint. Joints 
vary according to the kind and amount of motion called 
for. Get a knuckle of ham, mutton, or a beef-joint at the 
market. Cut into it, and open up the joint, and study its 
structure. In all joints, the essential parts are the same. 
The ends of the bones are shaped according to the special 
needs of each joint. The ends are smooth, moist, and 
tipped with a thin layer of gristle, or cartilage. This 
smooth and glistening covering is bathed by a sticky fluid 
called the synovial fluid, so called because it is like the 
white of a raw egg. This is the oil often spoken of as 
“joint-oil,” furnished by nature to allow the rubbing-sur- 
faces to move smoothly over one another, and thus prevent 
too much wear and tear (Exper. 12). 
There are two principal kinds of joints, the fixed and 
the movable. Thus, the bones of the head, as we have 
seen, are firmly dovetailed into each other by jagged, saw- TIIE BONY ERA 1IEWORK. 
31 
like edges, which grow into each other from infancy. The 
bones of the sacrum are also firmly united to each other. 
These are the “fixed” joints. Movable joints allow the 
bones to glide on each other with more or less freedom of 
motion. They differ according to the motion needed. 
Such a joint as that at the hip is called a “ball-and-socket 
joint,” because the rounded head of the thigh-bone fits 
into the cup in the hip-bone. The ball-like head of the 
arm-bone works in the glenoid cavity of the shoulder-blade, 
and makes another ball-and-socket joint. The bones of 
the fingers also move on each other in this way. Such 
joints allow a greater variety of motion than any other 
kind. Again, bones are grooved and ridged so that one 
bone can glide over the other to and fro, like a door on its 
hinges. This is called a “hinge-joint.” Such joints are 
found at the knee, and between the lower jaw and cranium. 
Sometimes a kind of peg in one bone fits into a hole in 
another, and forms a “pivot-joint.” The two bones (atlas 
and axis) at the top of the spine are joined in this way 
(Exper. 13). 
33. How Bones are tied to each other. Ligaments.— 
The bones are tied together, kept in place, and their move- 
ments limited, by tough and strong bands, or straps, called 
ligaments, meaning “to bind.” They may be seen in any 
of the movable joints, — say of the calf, sheep, or.chicken, 
— and have the look of white, silvery cords. Some of the 
ligaments are as thin as a piece of tape ; while others, 
as at the side of the knee, or at the shoulder, are very 
thick. Some cross each other, as in the knee-joint ; while 
others go all round the joint, and completely shut it up in 
a cap. This prevents the bones from being easily dislo- 
cated, or slipped out of place. It is a difficult matter to 32 
OUR BODIES. 
carve a turkey or a fowl, because one has to cut through 
these ligaments before he can force the limbs apart to 
serve it out in portions. There is the same difficulty in 
separating the two bones in a shoulder or leg of mutton, 
because they are held firmly together by strong ligaments 
(Exper. 14). 
34. Hints about the Health of Bones. — The bones of 
children are flexible, and capable of being bent by long- 
continued strain ; because there is more animal matter 
than in later years. Therefore great care must be taken 
with the positions which children take at home, at school, 
and elsewhere. Allow a child to walk too early, before 
the legs are strong enough to bear the weight of the body, 
and “bow-legs” result. At school, the desks should not 
be too low, thus causing a forward stoop ; or too high, 
thereby throwing one shoulder up too much, and giving a 
twist to the spine. If the seats are too high, the feet have 
no support, and injury to the thigh may result. If too 
low, there is undue strain on the shoulder and backbone. 
Round shoulders and curvature of the spine may result 
from long-continued positions of this kind. The feet 
should rest firmly on the floor, and the edge of the desk 
should be about one inch higher than the level of the 
elbows. A line dropped from the edge of the desk should 
strike the edge of the seat. Three sizes of desks should be 
used in every schoolroom, and more in ungraded schools. 
Seats should be regulated according to the size of the 
pupil, and frequent changes of seats should be made. 
Young people should not get into the habit of taking 
unlikely positions, such as sliding down into the seat, 
sitting on the foot, or on the small of the back. Bending 
over too much while reading, writing, sewing, or other- THE BONY FRAMEWORK. 
33 
wise at work, is apt to cause spinal curvature and round 
shoulders. 
The prevailing fashion of using tight and high-heeled 
boots and shoes cannot be too strongly condemned as 
both hurtful and ugly. High heels throw the weight of 
the body forwards, and force the foot down on to the toes. 
This will in time not only crush all shape out of the toes, 
causing tender feet, corns, bunions, distorted joints, and 
in-growing nails, but makes the natural gait stiff and un- 
gainly. 
Note. The bones in early life readily yield to undue pressure. We 
have all heard of the distorted feet of Chinese women. These people think 
it is low-bred for women to be useful, and have big feet; so they bind a baby’s 
feet, if it is a girl, with strong bands, to prevent them from growing. When 
they grow up, these poor women are scarcely able to move about. 
Collateral Reading. Lincoln’s School Hygiene, “ American Health Prim- 
ers.” 
TEST QUESTIONS FOR REVIEW. 
1. What do you mean by the skeleton ? What are its uses ? 
2. How many bones are there in the human body ? 
3. Describe the composition of bone. 
4. What experiments show the composition of bone ? 
5. Explain the general structure of bone. Illustrate. 
6. Explain and give examples of the different kinds of bones. 
7. Describe the minute structure of bone. 
8. What is the periosteum? and what is its use? 
9. Name the principal divisions of the human skeleton. 
10. Into what parts is the head divided? 
11. What is the cranium ? Mention each bone by name. 
12. Give an account of the bones of the cranium. 
13. What is the face ? Name each bone. 34 
OUR BODIES. 
14- Describe the bones of the face. 
15. What are sutures ? Explain fully their use. 
16. What is the trunk? its two cavities ? 
17. Describe the diaphragm. 
18. Of what parts does the trunk consist? Mention each bone. 
19. Describe in full the spine. Its uses. 
20. What are the ribs ? what are their uses ? 
21. How are the hips made up? 
22. Describe the upper limbs. Mention the bones of each part. 
23. Describe the hyoid bone. 
24. Describe the three bones of the upper arm. 
25. Describe the two bones of the fore-arm. 
26. Describe the wrist, the palm, and the fingers. 
27. Describe the lower limbs. Name each bone in the three parts. 
28. Describe the thigh, the lower leg, the foot. 
29. What is the knee-cap ? the tendon of Achilles ? 
30. Explain the uses of bones. 
31. How do bones grow? How are they repaired? 
32. What is a joint ? Describe in full. Mention the different kinds 
of joints. 
33. What are ligaments? Describe them. What are their uses? 
Name some important ligaments. 
34. Give some hints about the health of bones. 
35. What is meant by a dislocation? fracture? sprain ? 
36. Give from memory the “ review analysis ” of the skeleton. THE BONY FRAMEWORK. 
35 
1 Frontal (forehead), 
2 Parietal, 
2 Temporal (temples), 
1 Occipital (back of head), 
1 Sphenoid (wedge-shaped), 
1 Eihmoid (sieve-like). 
REVIEW ANALYSIS: THE SKELETON-(206 bones). 
i. Cranium (8 bones) 
THE HEAD 
(28 bones). 
2 Malar (cheek), 
2 Nasal (nose), 
2 Upper Jaw-bones, 
1 Lower Jaw-bone, 
2 Palate bones, 
2 Lachrymal bones, 
1 Vomer (plough-share) bone, 
2 Turbinated (spongy) bones. 
II. Face (14 bones) 
III. The Ear (6 bones) . 
Hammer, 
Anvil. 
Stirrup. 
7 Cervical (neck) Vertebrae, 
12 Dorsal (back) Vertebrae, 
5 Lumbar (loins) Vertebrae, 
Sacrum (sacred bone), 
Coccyx (cuckoo-bone). 
I. Spinal Column (26 bones). 
THE TRUNK 
(54 bones). 
II. The Ribs (24 bones). 
7 True Ribs, 
3 False Ribs, 
2 Floating Ribs. 
III. Sternum (breast-bone). 
IV. Two Hip-bones. 
V. Hyoid Bone. 
UPPER LIMBS 
(64 bones). 
Upper Arm . 
Scapula, 
Clavicle, 
Humerus. 
Fore-arm 
Ulna, 
Radius. 
8 Carpal (wrist) bones, 
5 Metacarpal bones, 
14 Phalanges (fingers). 
Hand . 
LOWER LIMBS 
(60 bones). 
Thigh . 
Femur (thigh-bone). 
Lower Leg . 
Patella (knee-pan), 
Tibia (shin-bone), 
Fibula (splint-bone). 
7 Tarsal (ankle) bones, 
5 Metatarsal (instep) bones. 
14 Phalanges (toes). 
Foot 36 
OUR BODIES. 
CHAPTER III. 
THE MUSCLES. 
35. The Muscles. — The smallest child or the tiniest 
insect can move its own limbs when it pleases, but the 
largest vegetable and the sturdiest tree never move except 
some cause outside of themselves act upon them. Move- 
ment in man is made by muscles. The limbs are moved 
by muscles. Even the motions of the stomach and the 
action of the heart are controlled by muscles. Muscles 
move the skin. In many animals this action is well 
marked, as when the horse shakes his hide to get rid of 
biting flies. Muscles move the bones, the fingers, and 
toes, the mouth, and the eyelids. All motion in the body 
is dependent upon them. 
36. The Structure of Muscle. — Muscle is simply the 
lean meat, or flesh, of the body (Exper. 16). When we 
eat beefsteak or lean mutton for dinner, we are eating 
muscle. Muscles are made up of bundles of fleshy strings 
called fibres (Fig. 13), held together by a very thin web of 
tissue, not unlike the thinnest of tissue paper. Each fibre 
is made up of a great many smaller fibres, called fibrils, 
held together in the same way (Figs. 14 and 15). Each 
fibril consist of rows of little cells, arranged like a string 
of beads. This gives the muscles a peculiar striped look 
under the microscope, which marks the ordinary muscles THE MUSCLES. 
37 
of the body. When corned beef has been “ boiled to 
Fig. 12. — Principal Muscles of the Front of the Body. 
rags,” as we say, the web of connecting tissue is partly 
dissolved by heat, and the fibres are plainly seen (Exper. 17). 38 
OUR BODIES. 
37. How Muscles act.— Muscles have a peculiar 
power of their own. This is the power to contract or 
shorten themselves (Exper. 
18). In order for a muscle 
to act, it must be stimulated. 
This stimulus, or that which 
gives it the power to act, 
is the nerve-force flowing 
through the nerves distri- 
buted to the muscles. Con- 
traction is not, however, the 
natural state of a muscle. After a longer or shorter time, 
it is tired, and begins to relax. 
Even the heart, the hardest- 
working muscle of the body, 
pumping blood night and day 
all the days of our life, has a 
short time to rest between its 
beats. 
38. Kinds of Muscles. — Muscles are of two kinds, 
voluntary and involuntary. 
Voluntary muscles are those 
which can be made to act 
under the influence of the 
will. Such muscles make up 
the bulk of the red meat, or 
fleshy parts, of the body, and 
form a covering for the bony 
skeleton. The involuntary 
muscles are those which carry 
on their work without the 
use of the will — indeed, we cannot prevent them acting. 
Fig. 13. — A Muscular Bundle teased out to 
show its Fibres. 
Fig. 14. — A Fibre of Muscle, showing 
the separate Disks of which it is com- 
posed at a and b. 
Fig. 15. — Portions of Muscular Fibre highly 
magnified. THE MUSCLES. 
39 
Among these muscles may be mentioned those of the 
stomach, the bowels, the lungs, and the heart. When they 
contract, they force along the contents of these organs. 
In this way the blood is forced out of the heart, the food 
out of the stomach, and so on. If these muscles were not 
entirely independent of the will, they would cease to act 
the moment we fell asleep ; and death would be the result. 
As it is, the organs of circulation, respiration, and diges- 
tion continue their work at all times ; because the will has 
no power over them. 
39. Arrangement of Muscles. — The muscles are ar- 
ranged, for the most part, so as to oppose each other in 
action. Thus, when one set produces motion in one direc- 
tion, there is, opposite to it, another group of muscles, 
which draws the part moved back into place again. When 
a piece of lean meat is brought from the market, it looks 
like a solid mass of flesh. It really consists of parts of 
several distinct muscles. Each of these muscles, when 
separated, will have the following form : — 
A middle or thick part, called the belly. Two tapering 
ends, one attached to a fixed bone, and called the origin; 
the other connected with a movable bone, and called the 
insertion of the muscle. These tapering ends are attached, 
or tied, to the bones by means of sinews, or tendons. 
As a muscle acts only by contracting, each movable 
bone must be supplied with at least two opposing muscles. 
One of these contracts, and draws up the limb : this is 
called a flexor muscle. The other, on the opposite side, 
by contracting, stretches out the limb : this is called an 
extensor muscle. Take, for instance, the two main muscles 
of the arm. When we bend the arm, we notice that the 
muscle in front of the upper arm swells up, and becomes 40 
OUR BODIES. 
hard. This is the biceps or two-headed muscle, which 
has contracted in obedience to the will, and, by its con- 
traction, has drawn up the fore-arm. When we wish to 
straighten the arm, we do not merely relax this muscle; 
for, if we did, the arm would simply fall into the straight 
position. A muscle at the back of the upper arm, called 
the triceps, the three-headed muscle, now contracts in 
obedience to the will, and, by its contraction, straightens 
the muscle (Exper. 19). 
40. The Tendons. — If we bend the leg or arm, and 
grasp the inside bend of the joint with the hand, we feel 
the motion of cords just beneath the skin (Exper. 20). 
Fig. 16. — Showing the Muscles and Tendons of the Hand, 
These are the tendons, or sinews, forming the tapering 
ends of muscles (Fig. 16), which are fastened to the bone. 
Tendons are white, glistening cords, like belts or straps, 
which connect the muscles with the bones. They are THE MUSCLES. 
41 
exceedingly strong, but flexible. Children often amuse 
themselves by taking the leg of a fowl, a rabbit, or some 
other animal, and moving the toes by pulling a white cord 
in the leg. This cord is a tendon. 
Tendons are most numerous about 
the joints, especially the larger 
ones, like the knee and elbow. 
They save a great deal of space, 
and allow great freedom of move- 
ment, where muscles large enough 
to do the work would be exceed- 
ingly bulky and clumsy. The 
longest and strongest tendon in 
the body is the tendon of Achilles 
(Fig. 17). The tendons of the 
muscles which bend the knee, and 
are felt in the bend of the joint, 
are commonly called the “ham- 
strings ” (Exper. 21). 
41. The Bony Levers of the 
Body. — The word lever means 
simply a rigid bar, or rod, which 
moves about a certain fixed point, called the fulcrum. We 
have all seen a man trying to raise a heavy stone with a 
crowbar. He places one end of the bar under the stone, 
and presses down the other end. In this case, the bar is 
the lever, and the ground under the bar the fulcrum. The 
pressure which the man applies is called the power, and 
the stone to be lifted is called the weight. We have the 
same thing in a seesaw, where the plank is the lever, and 
the block on which it rests, the fulcrum ; while the power 
and weight ai;e first at one end, and then at the other. In 
Fig. 17.—Bones of Leg and Foot, 
and Muscles of Calf. 42 
OUR BODIES. 
a lever, then, we have three things to consider, — the ful- 
crum, the power, and the weight. Levers are divided into 
different classes, according to the position of these three 
things (Exper. 22). 
(1) First Class. — Levers of this class have the fulcrum 
in the middle. 
(2) Second Class. — In this class, the fulcrum is at one 
end, the power at the other, and the weight in the middle. 
(3) Third Class. — In this class, the fulcrum is at one 
end, the weight at the other, and the power between them. 
In the various movements of the body, we have instances 
of all three kinds of levers. 
The skull, as it nods backwards and forwards upon the 
atlas, is an instance of the first class of levers. It is like 
the seesaw we have just spoken of. The skull rests on 
the spinal column, which is the fulcrum : the muscle at the 
back of the neck is the power, and the front part of the 
skull is the weight. We have all seen a woman running 
a sewing-machine with her feet. In this case, the ankle- 
joint is the fulcrum ; the tendon of Achilles, attached to the 
heel-bone, is the power; and the weight is at the toes. 
This is another instance of the first class of levers. When 
we stand on tiptoe, the power required to raise the body 
is applied to the heel-bone by its stout tendon. The toes 
are the fulcrum, and the bones of the foot support the 
weight. We have in this case a lever of the second class. 
The third class of levers is the one which occurs most fre- 
quently in the body. Of this we have an example when 
we bend the fore-arm. The elbow is the fulcrum, the fore- 
arm and hand are the weight, and the biceps muscle, at 
its insertion in the radius, is the power which is thus 
placed between the weight and the fulcrum. THE MUSCLES. 
43 
42. How we walk.—Though we all walk without con- 
scious effort, this is done only after much practice. This 
is seen in the efforts of the child who is learning to walk. 
Let us try and understand so common an act of every-day 
life (Exper. 23). Stand erect with the heels together, and 
take a step, beginning with the left foot. The foot is 
lifted, and the knee raised : then the foot is thrust forward 
by the thigh and leg muscles, and allowed to fall on the 
ground. The trunk is thus moved over a new centre of 
gravity : the weight will be felt passing from the arch 
towards the toes as the body is thrown forwards. Mean- 
while the muscles at the back of the right leg are felt to 
contract. The knee is fixed by the thigh-muscles : then 
the muscles of the calf lift the heel off the ground, and 
allow the weight of the body to rest on the toes ; that is, 
the centre of gravity is brought forwards. As the right 
foot reaches the ground, the weight of the body falls on 
the heel first, and then on the arch of the foot. Thus, by 
pushing forward first one limb, and then another, and 
by moving the body to the new centre of gravity, we are 
able to walk. 
43. A Few Important Muscles. — There are about five 
hundred muscles in the human body, all necessary for per- 
forming the various movements and operations of this 
complicated machine, — our body. There are about fifty 
in each arm and hand. Six little muscles move each eye- 
ball. Muscles are of all kinds of shapes, —round and flat, 
long and short, fan-shaped, etc., — suited to the work they 
are to do. Some are large, like the great breast-muscles ; 
while others are very small, like the tiny muscles which 
move the delicate little bones of the ear (Exper. 24). 
Each muscle has its own name, given to it from its pecul- 44 
OUR BODIES. 
iar shape or size, or from the work it has to do. We 
chew our food by the help of two strong muscles, the tem- 
poral and masseter muscles, called the “ chewing-muscles,” 
which move the jaws. These chewing-muscles are very 
large and strong in flesh-eating animals, like the lion and 
tiger. Turn the head suddenly to one side, and the edge 
of the long sterno-vicistoid muscle is plainly seen and felt : 
one end is tied to the skull, the other to the collar-bone. 
It acts to turn and brace the head. Inside the cheek is a 
flat muscle, called the buccinator or trumpeter’s muscle. 
It is largely developed in glass-blowers, and persons who 
play on wind-instruments. The strong muscle on each 
side of the breast, or chest, is called the great pectoral. 
The large, thick muscle covering the shoulder is called 
the deltoid, because it is thought to resemble the Greek 
letter A (delta). The action of the biceps, which bends the 
fore-arm, and the triceps, which straightens it, has been 
explained. The trapezius, so called from its supposed 
resemblance to a mathematical figure, covers the shoulder- 
blade, like a monk’s hood, and helps move the shoulder. 
The latissimus dorsi, meaning the very broad muscle of the 
back, is the “ climbing ’’-muscle of the body, and helps 
pull the arm backwards. The huge gluteal muscles make 
up the fleshy portion of the back of the thigh. They 
move the thigh backwards, and help keep the body erect. 
Two strong muscles form the largest part of the calf of 
the leg, the gastrocnemius and solcus. The first literally 
means the belly, or calf, of the leg; and the second is so 
named because it is broad and flat, like a sole-fish (Fig. 17). 
The tendons of these two muscles unite to form the tendon 
of Achilles. These muscles are brought into use in walk- 
ing, standing, dancing, and leaping. They are of very TIIE MUSCLES. 
45 
great strength ; because, in raising the heel, they have to 
raise the entire weight of the body (Exper. 25). 
44. Why we need Exercise.— To be vigorous and 
healthy, every organ of the body must be used. Every 
organ and every tissue must act well its part to be of the 
best service. To keep the body in health, it is absolutely 
necessary that a certain amount of muscular action or 
exercise should be taken every day. -The reason for it 
is plain : the body is made up of certain tissues such as 
bone, muscles, and nerves. These tissues consist of a 
countless number of little cells (sect. 6), every one of which 
is born, lives its brief moment, then dies, and is cast 
out as waste or dead matter. The ever-changing blood, 
in its ceaseless current, brings them their nutriment. The 
tissues take what is specially suited to their wants, and 
return as waste matter whatever has become used up. 
Now, in every tissue, especially in the muscular tissue, 
this process is hastened by action. Exercise causes more 
frequent changes in the tissue-cells, and hence an in- 
creased flow of blood. The greater the amount of judi- 
cious exercise, the greater is the working-power of the 
individual. Muscular activity is, then, the chief agent in 
bringing about these wholesome tissue-changes. Muscles 
increase in size and strength according to the use made 
of them. The blacksmith uses vigorously the muscles of 
his right arm day after day, hence their size and strength 
become well developed. Change his business for that of 
a clerk, and the once brawny arms soon become small and 
weak. Let a muscle be kept idle for some time, and it 
loses in bulk and vigor. Some of us have heard of cer- 
tain people in India, who, as an act of worship, keep one 
arm raised above the head for many weeks. The muscles 46 
OUR BODIES. 
shrivel, and the arm becomes dried-up and useless. If a 
leg is broken, and kept in splints for six weeks or so, the 
muscles become feeble and wasted. It is only after a great 
deal of exercise, that the long idle limb regains its former 
size and vigor. 
45. Effect of Exercise on Various Organs. — Not 
only are the muscles themselves benefited by exercise, 
but, by their action, many other tissues and organs become 
more vigorous. The heart beats more vigorously in order 
to carry more blood to the tissues. More oxygen is taken 
in by the lungs, and more heat is developed. Hence the 
skin, kidneys, and lungs have to do more work to get rid 
of the waste products. Breathing is mainly done by mus- 
cular action : thus, exercise causes the lungs to draw in an 
extra amount of fresh air, and to get rid of more impure 
air. Again, exercise stimulates the muscles which con- 
trol the organs of digestion, thus giving a good appetite 
by creating a demand for food. In brief, muscular exer- 
cise keeps the whole machinery of the body in good 
working-order. 
46. Amount of Exercise. — Too much exercise, as well 
as too little, is a fruitful cause of ill-health. Exercise 
followed by fatigue, day after day, only does harm ; while 
judicious exercise with suitable rest is of great benefit. 
Hence the amount necessary to keep the body in the best 
trim is a most important and practical question. It is 
laid down as a pretty safe rule, that a person of average 
height and weight, engaged in study or any other indoor 
or inactive business, should have an amount of exercise 
equivalent to a daily walk of five miles along a level road. 
Growing children, as a rule, take more exercise than this ; 
while most men in the prime of life, working indoor, take THE MUSCLES. 
47 
nothing like this amount; and women take less. Of course, 
if one’s daily work is active and outdoor, no additional 
exercise is really necessary. Exercise may be varied in 
many ways, — the more ways the better. But, for the 
most part, it should always be taken in the open air. 
47. T ime for Exercise. — The best time to take exercise 
is about two hours after a meal. The body is the weak- 
est before breakfast. It is not best to do hard work, or 
take severe exercise, before this meal. Those who go to 
work or study before breakfast, should first eat half a slice 
of bread or a cracker, or even drink a glass of milk, — just 
enough to “stay the stomach,” and save the feeling of 
faintness, or “sinking” at the stomach. Just after a full 
meal, the stomach is busily doing its duty. Hence exercise 
at this time is apt to stop its action, and result sooner or 
later in dyspepsia. The evening is not the best time for 
exercise, because the body is tired after the labor of the 
day. It is useless to fix any exact rule. Ordinary work, 
or moderate exercise, as walking, is beneficial almost any 
time, except just after a full meal. 
48. Different Kinds of Exercise. — The kind of exer- 
cise it is best to take depends very much upon one’s 
daily occupation. Persons who sit at desks, stand at 
counters, or work in. close rooms as clerks, teachers, 
tailors, printers, etc., are prone to diseases due to lack 
of bodily exercise, and to foul air. Every person should 
know, or be taught to know, his own needs, and his own 
dangers. All sound persons should do some work, or take 
some exercise, with both body and mind every day. To 
get and to keep vigorous health, it is not at all necessary 
to increase the size of the muscles very much, or do great 
feats of strength. Walking is the best of all exercises. 48 
OUR BODIES. 
It takes us into the open air and bright sunlight. It puts 
new life into many important muscles of the chest, abdo- 
men, and limbs. With a brisk walk every day, taking 
care to keep warm and dry, no one need suffer from lack 
of proper exercise. Running, leaping, climbing, and other 
vigorous sports, are well enough, especially for children, 
if they are not kept up too long, and cause fatigue. 
Violent sports, such as base-ball and foot-ball, are severe 
exercises, and occasionally dangerous. Rowing is admir- 
ably suited to most persons of either sex. Horse-back 
riding, coasting, swimming, and skating are important 
helps to increase the bodily vigor. Certain sports also 
tend to beget self-reliance, coolness in danger, and a cer- 
tain dignity and grace of person. There is hardly any 
one kind of exercise, which, taken alone, is able to give 
even tolerable development of all the muscles. Hence 
light gymnastic exercises are cheap and convenient means 
to develop muscles not used in work and games. Grow- 
ing children should be trained every day at home or in 
school in the use of light wooden dumb-bells, light clubs 
or wands. A daily exercise of ten minutes will do much 
to develop feeble and narrow chests, to check the ten- 
dency to curvature of the spine and round shoulders so 
common with girls, and to give muscular strength and 
vigor to all parts of the body. 
49. Effect of Alcohol on the Muscles. — We have 
learned that it is the nerve-force flowing to the muscles 
which makes them contract or relax. Now, if we drink 
more or less of alcoholic liquor, the muscles are acted 
upon in a peculiar way. The nerve-force that controls the 
muscles is weakened, and they show a lack of control. 
Every one is familiar with the unsteady and staggering THE MUSCLES. 
49 
gait of a person who has drank ardent spirits. Those 
delicate movements which require the long training of 
groups of muscles, as in handling fine tools and doing 
gymnastic feats, cannot be made. A person may know 
the right way of making each movement, and may succeed, 
after a fashion, in clumsily doing it ; but, when a certain 
point of intoxication has been reached, this is impossi- 
ble. Under the influence of alcohol, the trained muscles 
become feeble and trembling, and are no longer wholly 
under the control of the will. All muscular control may 
be lost if alcohol enough is drunk, and deep breathing 
may be the only sign of life. 
This same lack of control is shown in the act of speech. 
Each and every word we utter, requires special movements 
of the muscles of the tongue, palate, and throat, all acting 
in harmony. After drinking alcohol, there is less control 
of the muscles : the reins are slackened, so to speak, words 
may be left out, cut short, or misplaced. According to the 
stage of intoxication, the words are clipped, stammered, 
or “mouthed,” or “thick,” from loss of control of the 
tongue. The muscles that move the eyes do not act in 
harmony: hence the drunken man “sees double.” The 
rapidity with which this loss of control is produced varies 
greatly with the individual, with the kind of drink, the 
rate at which it is drunk, and many other circumstances. 
Collateral Reading. Blaikie’s How to Get Strong, How to Stay So ; Blaikie’s 
Sound Bodies for our Boys and Girls; Exercise and Training, “ Health Primers.” 50 
OUR BODIES. 
TEST QUESTIONS FOR REVIEW. 
1. How do we move? Explain in full. 
2. What is muscle ? Describe its structure. 
3. Explain and illustrate contraction. 
4. Describe the two general kinds of muscles. 
5. How are muscles arranged to do their work ? Illustrate. 
6. What are tendons? Where are they found? What are their 
uses ? 
7. Explain how muscles act as levers of the three different classes. 
8. Give examples of each class. 
9. Describe in detail the act of walking. 
10. What is the number of muscles ? 
11. How are they adapted to different uses ? 
12. Mention and describe some of the important muscles of the body. 
13. Exercise. What is it? and why do we need it? 
14. The ill effects of too little exercise. 
r 5. Show how exercise affects the organs in general. 
16. How much exercise should we take ? 
17. What is the best time for exercise? 
18. Mention in some detail the different kinds of exercise. 
19. What is the effect of alcohol on the muscles ? FOOD AND DRINK. 
51 
CHAPTER IV. 
FOOD AND DRINK. 
50. Work, Waste, and Repair. — The body is in some 
ways — as we have learned in the Introduction—very 
much like a steam-engine. The bones and muscles corre- 
spond to the machinery. The motive-power is furnished 
by the food we eat. Our food is to us what coal and wood 
are to the engine. Like the locomotive, our bodies move 
about, and are warm, because a fire is always burning in 
them. This fire, like that of the engine, needs fresh fuel 
from time to time. Unlike the engine, our food is not 
burned in a separate part of the body. The food we eat 
becomes part and parcel of our body, and it is our whole 
body that is slowly burning. In order to keep up this 
bodily burning, or to oxidize the food, we must have oxy- 
gen. Without fuel and air, the fire in the engine will go 
out. So it is with the fire in our body. Without food 
and air, the combustion, or oxidation, of our bodies would 
soon flag, and we would soon die for want of them. When 
coal or wood is burned, we get ashes. When food is burned 
in the body, we get, not exactly ashes, but something like 
them, which is got rid of as useless substances. Again, 
the steam-engine wears out, and needs repair from time 
to time. So it is with our bodies. There is wear and tear 
constantly in every part. Every beat of the heart, every 52 
OUR BODIES. 
contraction of a muscle, and even our very thoughts, lead 
to waste. Every time we think, look, speak, or move, we 
do so at the expense of some minute portion of the tissues 
of the body. 
51. Why we need Food. — To make good this waste, 
there must be something taken into the body, or it soon 
suffers. The body is constantly wearing'away, and must 
be constantly built up again. Hence we see the necessity 
for food. The food, too, must contain the same things 
that the body has lost. The blood is the stream which 
carries this material for restoring the waste tissues of the 
body. Indeed, we may say that the blood is that material 
itself. It is simply the food we have eaten, in another 
form. Food must be of such a kind, and in such a quan- 
tity, as to supply an amount of nutriment to the tissues 
equal to the waste which takes place.* 
During early life, when the body is growing rapidly, 
more of tissue-food is needed than in adult life, when 
repair alone is called for. When the body has been wasted 
by disease, as typhoid fever for instance, much tissue-food 
is needed to repair the waste, and to restore the muscles 
to their former size and vigor. If but little or no food be 
taken, or if it is not of the right sort, the body slowly 
loses in weight. If we try to do without food, we grow 
chilly and cold, feeble, faint, and too weak to move. A 
point will at length be reached, at which death from starva- 
tion must take place. The bodily fire has gone out, and 
nothing but cold ashes is left. The cause of death, then, 
* The following admirable definition of a food has been given by Pro- 
fessor Henry P. Bowditch of Harvard Medical School: “A food is any 
substance, solid or fluid, which, when taken into the body, repairs the waste, 
or hinders the loss, of any of its tissues.” FOOD AND DRINK. 
53 
seems to be the chilling of the body by the loss of fuel. 
Thus it is that cold acts with starvation to bring about 
a more speedy end. 
52. Different Classes of Food. — For convenience, let 
us divide foods, or food-stuffs, into three great classes : — 
/. Nitrogenous Foods, or Albumens, sometimes called flesh- 
forming foods, contain, as their name implies, all the mate- 
rials requisite for restoring the tissues. They contain all 
four elements, — nitrogen, carbon, oxygen, and hydrogen. 
They are especially rich, however, in nitrogen, which forms 
an essential part of the animal tissues. These foods are 
called albuminoids, because they contain a certain white 
substance known as albumen, familiar to all as the white 
of an egg. Lean meat ; the cheesy part, or curd, of milk; 
pease and beans,—are rich in albumen. Wheat, barley, 
oats, and maize also contain albumen. A well-known 
group of plants with seeds enclosed in pods, or legumes, 
hence called “legumens,” is rich in a nitrogenous sub- 
stance, resembling the albumen of eggs and the gluten of 
flour. Pease, beans, and other vegetables of this group, 
are nutritious on account of this flesh-forming material 
(Expers. 26-32). 
II. Starches and Sugars contain carbon, hydrogen, and 
oxygen, but no nitrogen. They are sometimes called the 
“sugar hydrocarbons.” As their proportions of hydrogen 
and oxygen are the same as in water, we may consider 
them as carbon or charcoal dissolved in water. This class 
of food-stuffs forms a large proportion of all those vegeta- 
ble substances which are generally used as food. Wheat, 
barley, oats, rye, rice, maize, tapioca, arrowroot, sago, pota- 
toes, etc., are rich in starch. In fact, starch stands first in 
importance among the various vegetable foods. Starch 54 
OUR BODIES. 
in its natural state would be useless as food, because it is 
insoluble. It is only after it has been acted upon by 
the digestive fluids, and converted into sugar, that it be- 
comes soluble, and is capable of being taken up by the 
blood. The sugars themselves come from the fruits and 
vegetables, honey, and milk. The sugars serve as a kind 
of fuel, which is burned up by the oxygen in the body. 
The combustion of these fuel-foods develops and keeps 
up the necessary heat of the body, and the vital energy or 
strength which enables us to perform our various duties 
(Expers. 32-36). 
III. Oil and Fats contain carbon, hydrogen, and oxygen. 
They are sometimes called the “fatty hydrocarbons.” 
This class of foods is derived from the fat of meat, eggs, 
butter, and milk, also from the various oils. Most of the 
bread-stuffs contain more or less of fat or oil. The oils 
and fats supply about twice the amount of energy, whether 
manifested as heat or motor force, as that afforded by the 
combustion of an equal amount of starch or sugar (Expers. 
36-38). 
Inorganic Substances, or Mineral Foods. — Organic sub- 
stances, such as those included in the food-stuffs just 
described, are derived from living forms, as animals and 
vegetables. Besides these, the body demands a certain 
amount of inorganic substances, derived from the mineral 
kingdom. These are water, salt, iron, lime, magnesia, 
phosphorus, and potash. Except water and common salt, 
these substances generally enter the body only in com- 
bination with other food-stuffs (Exper. 38). 
53. Extra Foods, or Appetizers. — A vigorous appetite 
requires little else besides salt for an appetizer. Salt has 
been and is universally used by all animals and peoples. ROOD AND DRINK. 
55 
Salt has always been the symbol of life, health, and wis- 
dom. Animals will travel for miles to reach salt-licks, 
while men have risked their lives to get even a taste of 
salt.* Pepper, mustard, ginger, and other heating appe- 
tizers, are used to give flavor to tasteless foods, and to 
stimulate the sense of taste, and to increase the flow of 
saliva and gastric juice. So long as the “appetite comes 
with eating,” and ordinary food is enjoyed, the use of 
these stimulating appetizers is unnecessary, and becomes 
simply a matter of habit. 
54. Different Articles of Diet. — Vegetable Food.— 
The most important food of this class is bread, “ the staff 
of life.” There is no single food in the world which 
meets so many necessary wants of the body. Bread may 
be made from the flour of many kinds of seeds, such as 
oats, rye, Indian corn, etc. But, in this country, it is 
nearly always made from wheat. Wheat-flour gives us 
starch, sugar, gluten — a form of albuminous food. Hence 
wheat has nearly every thing to support life except fat. 
When we eat bread and butter, we have nearly a perfect 
food. Corn-meal is rich in nitrogen, and has a deal of 
oily matter. It is a highly nutritious and cheap article 
of food. Oatmeal is richer than flour in nitrogen and 
fat, and is, therefore, more nutritious. Rice, though rich 
in carbon, is one of the least nutritious of all the cereals. 
Pease and beans contain more nitrogen than any of the 
cereals, and are as rich in carbon as wheat-flour. The 
* In most countries, it is “cheap as dirt; ” while in parts of Africa it is 
worth its weight in gold. In India, a large revenue is raised from the salt- 
tax, salt being something which even the poorest native will buy. In old 
times, untold tortures were inflicted upon prisoners in Holland, by feeding 
them on bread alone, made without salt. 56 
OUR BODIES. 
common, or Irish, potato is a most important article of 
diet. Although it is more than two-thirds water, and has 
little nutriment, yet it is easily cultivated, easily kept, 
easily cooked, and easily digested, — a cheap and economi- 
cal article of diet. Ripe fruits, such as apples, pears, 
peaches, melons, grapes, oranges, etc., though not of much 
nutritious value, are prized for their agreeable flavor. 
Sugar and molasses are both extensively used for their 
flavoring cpialities. Their nutritious value is about the 
same as that of starch. 
Animal Food. — The foremost place among these must 
be given to milk, for it is the food of all others which 
gives us the necessary elements of nourishment in the 
simplest and best form. It contains a large quantity of 
water, casein, together with sugar and fat (Exper. 37). 
Eggs have a large amount of nutriment in a small space. 
Two-thirds of an egg is water, the rest albumen and fat. 
Eggs are cooked in many ways, and are generally easily 
digested. Meats, for the most part, consist of the mus- 
cles of the various animals. The most common are beef, 
mutton, lamb, veal, and pork. Meat is rich in albumen, 
and has more or less of fat. It is a most common and 
important article of diet, and, as a whole, is easily digested, 
except, perhaps, veal and pork. Fish is at once a cheap, 
abundant, and nourishing food. Poultry must be looked 
upon, like fish, as a useful, light food, especially for the 
sick. The flesh is easy to digest, and gives a deal of 
nourishment. 
Mineral Food.—Water is a mineral food, which will be 
described hereafter. There is about a half a pound of 
common salt in the body at any one time. But we are 
continually losing it. Tears, we know, contain salt; and FOOD AND DRINK. 
57 
it is also contained in the sweat. Many people think 
they do not eat any common salt, because they do not 
take it by itself. But they forget that most of the foods 
they eat, such as bread and meat, contain a little of this 
substance. The salts of potash are chiefly found in the 
vegetables we eat, especially lettuce. These salts help 
purify the blood. The salts of lime make the bones hard 
and strong. Iron is contained in very small quantities in 
many of the foods we eat. It helps to form good blood.* 
55. Artificial Drinks. — Our great natural drink, as we 
have learned, is pure water. Many savage nations know 
no drink save water, and require no other. Milk is also 
a natural drink. Of both milk and water we have already 
given an account. Now, from the earliest period of his- 
tory, man has contrived many ways to flavor his drink in 
some way or other. The greater portion of almost every 
drink is water; but, in various ways, other substances are 
mingled with the water, to give it a pleasant taste. Such 
drinks are artificial, and have ever been highly prized by 
all nations. Tea, coffee, cocoa, beer, wine, and distilled 
liquors, are the more common artificial drinks. All such 
beverages rank as articles of luxury, and not as the real 
necessities of life. 
56. Tea, Coffee, and Cocoa. — Tea was first brought 
to England about two hundred and fifty years ago. It 
was then sold for some ten dollars a pound, and did not 
come into general use. Its use has steadily increased, 
* Not many years ago, as the story is told, a certain gentleman desired in 
his will that his body should be burned instead of being buried. His friend, 
an eminent French chemist, saw that his wish was duly carried out; and, 
collecting the ashes of the body, he extracted from them enough of iron to 
make a mourning-ring. 58 
OUR BODIES. 
and millions of pounds are now consumed every year in 
every civilized country. The tea-plant is chiefly cultivated 
in China. When boiling water is poured on the dried 
leaves, a substance called theine is dissolved, together with 
other matters. The liquid so obtained is called a “decoc- 
tion,” and makes the common drink known as tea. 
Coffee comes to us mainly from the West Indies, Arabia, 
South America, and the East Indies. When boiling water 
is poured on ground coffee, it dissolves a substance called 
caffeine,* very much like the theine of tea. 
Coffee was first used in this country and England about 
the same time as tea. Many tons of coffee are consumed 
every year in the United States. 
The cocoa or chocolate tree is a native of tropical 
America. It has an active principle f which resembles 
theine and caffeine. 
Chocolate is cocoa ground up with sugar and certain 
spices. 
57. The Effect of drinking Tea and Coffee.—Tea 
and coffee contain a certain amount of nutritive material. 
They are useful additions to the diet, especially when used 
with milk and sugar. Cocoa is a much more nutritious 
food than either tea or coffee. Tea and coffee, however, 
are used mainly for their stimulating effects. They gently 
stimulate the nervous system, producing a slight feeling of 
excitement and a relief from fatigue. Unlike alcohol, they 
have no immediate re-action. Coffee is especially useful 
as a stimulant after severe labor, great exposure, and hard 
* Theine and caffeine are said to be the “ active principles ” of tea and 
coffee. 
t Named theo bromine, “ the food of the gods,” by Linnaeus the great 
botanist, who was fond of chocolate. FOOD AND DRINK. 
59 
study. Soldiers, sailors, miners, and others exposed to 
hardships, will thrive on scanty food if well supplied with 
coffee. There is rarely any necessity for one to drink tea 
or coffee. If drunk in moderation, they seldom do harm, 
especially for grown-up people in good health. Some per- 
sons, however, cannot drink even a single cup of coffee 
or tea without feeling the worse for it : headache, indiges- 
tion, heartburn, wakefulness at night, and constipation are 
the most common after-effects. Strong tea in large quan- 
tities should never take the place of ordinary food. Hard- 
working women and others, from choice or necessity, too 
often make their meals of dry toast and several cups of 
strong tea. Drank in excess, tea may weaken the action 
of the heart, and produce the peculiar beating after much 
exertion, known as “palpitation.” Hence we have “the 
tea-drinker’s heart.” Coffee and tea are injurious articles 
of diet for growing children. 
58. Alcohol.—Wh en the juice of apples is first pressed 
out, it is sweet. If kept warm, or allowed to stand, it soon 
begins to “work,” or ferment. The new cider loses its 
sweet taste, begins to bubble, and becomes of a very 
different taste and odor. The sweet cider has become 
“hard.” The sugar has changed into a gas, called car- 
bonic acid, which causes the bubbles, and alcohol, which 
gives a peculiar flavor. The juices of all kinds of ripe 
fruit will soon begin to “work,” or ferment, in the same 
way. The starchy grains of corn, rye, barley, and other 
cereals, if kept warm and moist, are rapidly changed into 
sugar, and then into alcohol. This change is called fer- 
mentation. Thus, wine is fermented grape-juice, and cider 
is fermented apple-juice. The carbonic acid partly evapo- 
rates, and partly remains to give life to the liquor. The 60 
OUR BODIES. 
intoxicating principle is the alcohol ; which, when it' is 
once taken up by the blood, acts upon the body in a 
remarkable manner. 
Alcohol is a clear, colorless liquid, with a burning taste. 
It is lighter than water, and mingles freely with it. It 
has a penetrating and peculiar odor. It has never been 
frozen : it burns readily, giving much heat, but little light. 
In its pure form, it was first obtained by distillation from 
wine : hence it was called “ spirits of wine ” by the Ara- 
bians, nearly a thousand years ago. 
Alcohol is a staple article of commerce, and is used in 
various trades and professions. It is extensively used by 
druggists in the preparation of drugs, by chemists as a 
solvent for many things, by the photographer in his art, 
and in hundreds of other ways. These important uses of 
alcohol are of little account compared with its use as a 
beverage. Almost every drink that intoxicates contains 
more or less of alcohol. Such beverages may differ a 
great deal, as much as old cider does from a rare wine, or 
the costliest brandy from the cheapest rum; and yet the 
intoxicating power of each one is due solely to the alcohol 
it contains, — the common ingredient of them all. Enor- 
mous quantities of alcoholic beverages are drunk in almost 
every part of the world. The effect of alcohol upon our 
bodies is a subject of the most profound importance. 
59. Principal Drinks that contain Alcohol. — Under 
the name of “ beer ” may be included lager-beer, ale, and 
porter. In a hundred pounds of good beer, there are 
from two to eight pounds of alcohol, about five pounds of 
a starch-like substance known as dextrine, and about half a 
pound of albuminoid matter. The remaining eighty or 
ninety pounds are water. The process of making beer is FOOD A AD) DRINK. 
61 
called brewing. Wine is made from the sweet juices 
of fruits, which are pressed out, allowed to ferment, and 
then bottled. Grapes are chiefly used for wine-making. 
On an average, a hundred pounds of wine contain ten to 
fifteen pounds of alcohol. 
By heating a fermented liquid, the alcohol in it can be 
readily driven off in the form of vapor : this is condensed 
in a cool receiver, and the result is a new and stronger 
liquor. This process is called distillation. The alcohol 
of commerce is distilled from whiskey. Beverages thus 
distilled from liquids which contain alcohol are commonly 
known as “spirits” and “ardent (burning) spirits.” 
Brandy is distilled from wine ; whiskey from fermented 
corn and rye ; gin from barley and rye, and afterwards 
flavored with juniper berries ; and rum from fermented 
molasses. Distilled liquors contain from 40 to 50 per 
cent of alcohol; the rest being water, flavored with various 
aromatics (Exper. 38). 
60. Alcohol as a Food. — A certain portion of a small 
dose of alcohol is probably utilized in the body as a food, 
just as tea and coffee are, and serves to hinder the waste 
of the tissues in a very limited way. Scientifically speak- 
ing, then, alcohol may be regarded as a food in the widest 
sense of the word. Now, because alcohol is a possible 
food, it by no means follows that it is a safe food. In fact, 
it is plainly evident to any sensible person, that alcohol is 
so dangerous an article of diet, that, practically, we do 
not call it a food, but a poison. Certain powerful drugs, 
arsenic for example, may hinder the waste of the tissues ; 
but we certainly should not class or use them as food on 
this account. As a beverage, alcohol in its various forms 
is the deadly enemy of human life, either from a physical, 62 
OUR BODIES. 
moral, or intellectual point of view. The position of alco- 
hol as a substitute for, or as an addition to, ordinary food, 
cannot be correctly assigned without reference to its effects 
upon the nervous system,—effects so rapid, so far-reach- 
ing, so hurtful, and so poisonous, that its influence upon 
the general nutrition is of little account. The habitual 
drinker of alcohol seldom has any well-considered grounds 
of economy or health for his indulgences (though prone to 
excuse himself in this way), but merely desires the imme- 
diate and so-called agreeable effects. The argument in 
favor of the use of alcoholic liquors, because the taste for 
some stimulant is so universal, is worth but little. All of 
us, unfortunately, wish to do many things which we had 
better not, and without much regard to the far-reaching 
results.* 
61. Alcohol and Work. — Does alcohol enable us to do 
more work ? Many experiments have been made to test 
this point ; and, like all such experiments, they are unsat- 
isfactory. According to the late Dr. Parkes, one of the 
best authorities on the subject, a small quantity of alcohol 
does not materially affect bodily labor. But more than 
two ounces daily really lessens the power of sustained and 
* Sir Henry Thompson, the eminent English surgeon, states his own 
assured conviction that there is no greater cause of moral and physical evil, 
than the habitual use of alcoholic beverages, even when restricted to an 
amount held to be quite within the limits of strict moderation. Sir Henry 
further adds, that such habitual use injures the body to an extent that few 
people are aware of, and that it is, in reality, the true cause of a very large 
proportion of the most dangerous and painful maladies that come under the 
care of the surgeon. 
Dr. Andrew Clark, an eminent physician, recently stated that he had 
gone through the wards of his hospital, and had come, after careful thought, 
to the conclusion that seven out of ten owed their ill-health to alcohol. FOOD A/YD DRINK. 
63 
severe muscular work. We shall learn in a following 
chapter, that alcohol increases and weakens the beat of 
the heart, and lowers the bodily temperature. With the 
pumping-engine of the body working more feebly, faster, 
and with less heat in the body, because of alcohol, it is not 
at all strange that the capacity for muscular exertion should 
be lessened. At first, alcohol may give a slight and short 
renewal of strength ; but it is only for the moment. It 
is rapidly followed by a diminished ability for work. 
Hence, men who are in training for boat-racing, base-ball, 
foot-racing, and other sports where great exertion is called 
for, are never allowed to use alcoholic liquors. Instinct 
and experience have taught this to uncivilized people. 
The Indian porters of South America, when they travel 
upon their hard journeys, with heavy loads upon their 
backs, are careful not to take a drop of alcoholic drink. 
Experience teaches them that they can do their severe 
work better without it. 
Collateral Reading. Edward Smith’s Health (first four chapters), and 
Foods, by the same author. 
TEST QUESTIONS FOR REVIEW. 
1. To illustrate work, waste, and repair, how may you compare the 
human body to a steam-engine ? Explain in detail. How does 
the comparison fail in some things? 
2. Why do we need food ? 
3. What are the three great classes of foods? 
4. Describe and illustrate the nitrogenous foods. 
5. What are the starches and sugars ? Give examples. 
6. Describe and illustrate the oils and fats. 
7. What is meant by the inorganic or mineral foods? 64 
OUR BODIES. 
8. What do you mean by “appetizers ”? Illustrate. 
9. Describe the principal kinds of vegetable food; animal food. 
10. What is the use of mineral food? 
11. What can you tell about artificial drinks? 
12. Tell what you can about tea; coffee; cocoa. 
13. What effects do tea and coffee produce? 
14. Show how alcohol is made. 
15. Describe the properties of alcohol. 
16. What can you say of the extent of its use as a beverage ? 
17. Mention the principal beverages that contain alcohol. 
18. What can you say of its use as a food? 
19. Has it any nutriment of any value ? 
20. Can alcohol take the place of ordinary food to any extent? 
21. Is alcohol a narcotic poison? 
22. Does experience or observation shed any light on this point? 
23. What special effect must always be considered ? 
24. Is it an easy matter to estimate this effect? 
25. Does alcohol enable a person to do more work? Illustrate, both 
from the text and from your own reading. DIGESTION. 
65 
CHAPTER V. 
DIGESTION. 
62. General Plan of Digestion. — Food substances 
cannot serve the needs of the body until they have been 
converted into blood. In order to become blood, food 
must first be dissolved. This is done in the alimentary 
canal. This canal is a long tube, which runs through the 
body from the lips to the lower end of the spine. Begin- 
ning at the mouth, this canal, continued as the gullet, 
passes down through an opening in the diaphragm (Fig. 3), 
which forms the partition between the chest and abdomen. 
Below this it swells out into a large bag, called the stomach. 
It then narrows again into the small intestine, which lies 
coiled up upon itself in the cavity of the abdomen. It 
then swells out again into the large intestine, which opens 
at the bottom of the spine, to discharge the useless parts 
of the food, together with certain waste products which 
are got rid of through the same outlet (Fig. 18). This 
long digestive tube is lined throughout by a soft, moist, 
reddish kind of very thin skin, called mucous membrane. 
Layers of muscles surround the tube, which strengthen it, 
and help push along the food. In and around this tube 
are hollow organs, called glands. They pour out certain 
fluids, which alter the food chemically, and so fit it for 
absorption into the blood. The process by which the food 66 
OUR BODIES. 
is turned into matter fit to mix with the blood, is called 
digestion. 
63. What takes Place in the Mouth. Chewing of 
the Food. — The mouth is a hollow box, with a movable 
floor formed by the tongue 
and lower jaw (Exper. 39). At 
the top is the hard palate ; 
in front, the lips and teeth ; 
and at the sides, the cheeks 
and teeth. The moment food 
is taken into the mouth, it is 
rolled over by the tongue, 
and crushed and ground into 
very small pieces by the 
teeth. This process is called 
chewing, or mastication. 
64. The Teeth. — The 
teeth are small, hard, white, 
bone-like bodies fixed in the 
jaws, pressing against each 
other as the jaws work, so as 
to cut and grind the food. 
They are fastened into the 
jaws by roots, which sink 
into the bony sockets some- 
what in the same way as a 
nail is held in a piece of wood. Teeth are made of three 
things,—dentine, cement, and enamel (Fig. 19). Dentine, 
the familiar ivory of commerce, is a bone-like substance, 
which forms the inside and body of the tooth. Outside 
of this dentine is a layer of cement; but, when the tooth 
appears above the jaw, the enamel takes its place. It is a 
Fig. 18. — Diagram of the Digestive System 
or Alimentary Canal. DIGESTION. 
67 
hard, shining kind of polish, looks like ivory, and gives 
a strong protection for the exposed part of the tooth, 
called the “crown.” The teeth are hollow: the inside 
space holds a delicate substance called the pulp, well sup- 
plied with nerves and blood-vessels, which enter at the 
root of the tooth (Exper. 40). 
The Teeth of one-half of the jaw separated. 
Fig. 19.—Vertical Section through a 
Tooth lodged in its Socket. 
Fig. 20. — The Teeth 
A child when born has no teeth : afterwards, however, 
it has two sets. The first set, or milk-teeth, twenty in 
number, are shed in childhood. The second set, or per- 
manent teeth, thirty-two in number, gradually take their 
place. The teeth are arranged in the same way, and 
number the same, in each jaw, and in each half of each 
jaw (Fig. 20). Thus, beginning at the centre of the jaw, 
there are eight incisors, or cutting-teeth, or two on each 
side. They have sharp, chisel-like, cutting-edges, which 
cut up the food. These teeth are largely developed in 
gnawing-animals, such as rabbits, squirrels, rats, and the 68 
OUR BODIES. 
beaver. Then come the canine or clog teeth, two in each 
jaw, so called because they are strongly developed in dogs, 
cats, tigers, and other flesh-eating animals. Next in order 
come the two-pointed teeth, called the bicuspids, four in 
each jaw. They are so called because they have two 
points, or cusps, for grinding the food. After these come 
the largest and strongest teeth m the head, which do the 
hardest work. They are called molars, or “grinders.” 
There are six of them in each jaw. They have broad 
crowns, with four or five cusps or ridges for grinding. 
The last molars are commonly called the “wisdom-teeth 
because they do not usually appear before the age of 
twenty, or the “age of wisdom ” (Expers. 41, 42, 43). 
Secretion. —It is well to explain at this point the exact meaning of secre- 
tion and excretion. The word secretion comes from a Latin word which 
means to “sift or separate:” excretion comes from the Latin, and means 
“to sift out from.” Both words are used to express the sifting of some 
substance from the blood. A secretion is something taken from the blood 
to be used again in the body for some special purpose; while an excretion 
is waste matter, and is thrown out of the body entirely. Thus, the salivary 
glands secrete the saliva, and the liver secretes the bile. Sweat is an excre- 
tion, sifted out of the blood by the sweat-glands. Those parts of the body 
which are engaged in secretion and excretion are called glands. There 
are a great number of glands in the body, varying in size, from the liver, 
which weighs about five pounds, to the small glands in the intestines, which 
are invisible to the naked eye. All glands, from the simplest to the most 
complex, have the same foundation structure. They are built, so to speak, 
of identical material. They consist essentially of a fine skin, or mem- 
brane, which is covered on one side with a layer of exceedingly minute 
bags called epithelial cells; .while it rests upon capillaries on the other side. 
These cells have the power of drawing the peculiar secretion of the gland 
out of the blood that is circulating through the capillaries. The moist, 
tender skin, or lining, on the inside of our lips, is a familiar example of this 
secreting-membrane. A gland may be merely a pouch in the basement 
membrane; or the membrane may be elaborately twisted, branched, made up 
like bunches of grapes, and so on, into all kinds of complex glands (Fig. 21). 
Why and how the cells in the liver make bile, and not gastric juice; those in DIGESTION. 
69 
the stomach make gastric juice, and not sweat; those in the skin make sweat, 
and not saliva; and so on, — we do not know, and we can hardly imagine. 
Excretion will be described in full in chap. xi. 
65. Mixing the Food with Saliva.—While the food is 
being chewed, it is moistened by a liquid called the saliva, 
or spittle, which flows into 
the mouth from six little 
glands. They are called, 
as a whole, the salivary 
glands (Fig. 21). There 
are three of them on each 
side, in the following posi- 
tions : The parotid gland, 
below and in front of each 
ear ; * the submaxillary, 
under the lower jaw ; and 
the sublingual, under the 
tongue, in the floor of the mouth. Each gland opens into 
the mouth by a little tube. They have a certain resem- 
blance to a bunch of grapes, with a tube for a stalk 
(Exper. 44). 
Saliva is rapidly poured into the mouth while the grind- 
ing of food is going on. Three or four pints of saliva are 
secreted daily. Sometimes these glands are busily at 
work, even before we actually taste food. Touch the 
tongue with the finger, and the saliva will flow : it also 
pours into the mouth, even at the sight, smell, or thought 
of food. This is what is commonly called “making the 
mouth water.” The saliva not only softens and mixes 
with the food, and keeps the mouth moist, but it also has 
Fig. 21. — One of the Salivary Glands. 
* This gland, especially in childhood, sometimes becomes inflamed and 
swollen. This disease is familiarly known as the “mumps.” 70 
OUR BODIES. 
the power of acting upon all starchy matters in the food, 
ancl changing them into sugar (Expers. 47-52). These 
starchy matters, as we have seen, before they are mixed 
with saliva, are insoluble ; but, when changed into sugar, 
they are quickly dissolved in the stomach, and taken up by 
the blood.* 
66. How Food is swallowed. — The food is now ready 
to be swallowed. The soft, moist mass is carried back- 
wards by the tongue and the muscles of the mouth into 
the funnel-shaped top of the gullet, called the pharynx. 
The soft palate pushes up and backwards, so as to prevent 
the food from passing into the nose f (Fig. 22). 
Now, besides the opening from the pharynx into the 
stomach, there is also one into the windpipe. To prevent 
the food from getting into this opening, and choking us, 
the top of the windpipe is protected by a little lid, a kind 
of trap-door, called the epiglottis. When we swallow, the 
tongue, raised and pushed backwards, shuts this little lid; 
and thus a bridge is made, over which the food passes 
downwards into and through the gullet, and thence into 
* We can easily prove that the saliva changes starch into sugar: hold 
some boiled starch — or a little arrowroot, which is almost pure starch — in 
the mouth for a few minutes. We find that it gradually loses its thick, pasty 
nature, and becomes thin and watery, while at the same time it acquires a 
sweet taste. The fact is, the saliva has acted on the starch, and changed it 
into sugar in order to make it soluble. This shows the necessity of properly 
chewing our food. If we bolt our food without sufficiently chewing it, the 
saliva does not act properly upon it, and a great amount of extra work is 
thrown on the intestines. 
t During ancl after a severe attack of diphtheria, scarlet fever, etc., in 
which diseases the parts of the throat are apt to be partially paralyzed, the 
soft palate is not able to shut off this passage into the nose: as a result, milk 
and other food often comes up through the nose. Such patients must be fed 
very slowly and carefully. Smokers often show off their skill in smoking by 
sending the smoke “ through the nose.” DIGESTION. 
71 
the stomach. Sometimes, however, a morsel of food 
“goes the wrong way,” — that is, is drawn into the open- 
ing of the windpipe, or down into the air-tubes,—and 
then violent coughing follows : by this means it may be 
brought up again. If the substance is hard and large, 
like a boot-button, orange-seed, or peanut, a person, espe- 
Fig. 22. — Section showing Passages to the Gullet and Windpipe. 
dally a child, may be choked to death. The gullet, or 
food-pipe, is a tube about nine inches long, hanging loosely 
behind the windpipe. Its thick walls are provided with 
hoop-like muscles, which contract with a worm-like motion, 
well seen when a horse is drinking water, and so push the 72 
OUR BODIES. 
food along towards the stomach. The pellet of food is 
passed along from above downwards by these muscles* in 
some such way as we would push a ring along inside of a 
rubber tube (Exper. 45). 
67. Digestion in the Stomach.—The food, a moist- 
ened, partly digested mass, has now reached the stomach. 
The stomach is a pear-shaped bag, or pouch, capable of 
holding about two quarts of liquid (Fig. 23). When full, 
it is some twelve inches 
long, and four inches 
broad. It is placed 
across the upper part 
of the abdomen, directly 
under the diaphragm, 
the larger end to the 
left side. It has two 
openings. The opening, 
or ring, through which 
the food enters, and 
where the gullet ends, is called the cardiac orifice. The 
other, at the right end, where the intestines begin, and 
that by which food leaves the stomach, is called the 
pylorus, or gate-keeper. 
Fig. 23. —Section of Stomach. 
* It is important to remember, that, in swallowing, the food and drink do 
not simply fall down the gullet. Their passage is controlled by the muscles 
in such a way that they grip successive portions swallowed, and pass them 
along. Even in swallowing a pill, there is the same process. The smaller the 
pill, the greater the difficulty in swallowing; because the muscles have more 
trouble to get the necessary grip on it. Some of us have seen an acrobat 
or juggler stand on his head, and drink a glass of water, and even eat in this 
position. We see the same thing every day when we notice a horse or cow 
drinking from a pail of water on the ground. When the food is pressed 
backwards by the tongue into the top of the gullet, it is no longer under the 
control of the will: it is impossible to recall the mass, and it is necessarily 
carried on into the stomach. DIGEST70IV. 
73 
The walls of the stomach consist of three coats : (i) A 
tough, outer coat of fibrous tissue, which protects and 
strengthens the organ;.(2) a coat of smooth, or involun- 
tary, muscular fibre, which rolls the food about in the 
process of digestion, with that wave-like motion which we 
noticed in describing the gullet ; (3) a third or inner coat, 
in which the blood-vessels and nerves are spread out. 
This innermost or mucous coat is next to the food, and has 
its surface honeycombed with millions of little pits. We 
have all seen this in tripe. In the floor of each of these 
tiny pits, a number of tubes open. These tubes, during 
the process of digestion, are constantly pouring into the 
stomach a peculiar fluid, called the gastric juice (Exper. 46). 
The gastric juice is a clear, almost colorless, fluid, with 
a sharp, acid taste. It contains a peculiar substance, or 
ferment, something like yeast, called pepsin, and an acid, 
both of which are necessary to the digestion of food in the 
stomach. The amount of gastric juice has been variously 
estimated,—all the way from five to fourteen pounds 
daily. There is comparatively little in the stomach at any 
one time. There is no loss, for it is rapidly re-absorbed 
by the blood. 
Now, the moment the food reaches the stomach, the 
gastric juice begins to flow, the muscles begin to con- 
tract, and the whole organ takes on a churning motion. 
The food is rolled over and oyer, and thoroughly mixed 
with the gastric juice. Two rings, one at the entrance 
and the other at the outlet, keep the food in the stomach 
while it is being churned about and digested. The gastric 
juice has scarcely any effect on the starchy matters, but 
acts on the albumens, such as are contained in meat, 
cheese, eggs, etc., to make a complete solution. 74 
OUR RODIES. 
Some of these dissolved albumens, together with some 
of the starchy matters dissolved by the saliva, are at once 
sucked into the blood by the blood-vessels in the walls of 
the stomach. The remainder of the mass, a thick, pulpy, 
soup-like substance, resembling gruel, is called chyme, 
meaning juice, with an acid odor and taste. Chyme con- 
tains more or less albuminoid matters, together with the 
starchy elements which have not been changed into sugar, 
and all the fat. The fat may be seen floating in large 
drops on the surface of the chyme. The ring at the out- 
let, or pylorus, now relaxes ; and the partially digested food 
is forced in little jets into the duodenum, or first part of 
the small intestines (Expers. 52, 53, 54). 
68. Digestion in the Intestines. — The intestine is the 
tubular continuation of the stomach. It is divided into 
the small intestine, about twenty-five or thirty feet long, 
and the large intestine, five or six feet in length. To get 
all this into the small space it has to occupy, it is doubled 
upon itself many times. The first portion of the small 
intestine,* which is directly continued from the stomach, 
is called the duodenum, because its length is about equal 
to the breadth of twelve fingers. 
Let us now see what goes on in the duodenum. Two 
pipes, or ducts, unite, and enter it. One comes from the 
gall-bladder, and brings the bile; the other from the pan- 
creas, and brings the pancreatic juice. These two tubes 
unite, and enter the duodenum at the same place. 
The Uver is the large reddish-brown organ situated just 
under the diaphragm, and on the right and upper side of 
* The small intestine includes three parts, — duodenum, jejunum, and 
ileum. The large intestine includes the colon, ccecum, and rectum. DIGESTION. 
75 
the abdomen. It is the largest organ in the body, and 
weighs about five pounds. The liver secretes from the 
blood a greenish fluid called the bile. It is stored up in a 
kind of little pear-shaped bag attached to the liver itself, 
and called the gall-bladder (Exper. 59). 
The bile is a thin, greenish-yellow, bitter fluid. Some- 
times it is olive-brown in color ; but, when acted upon by 
the gastric juice, it takes on a distinctly yellow or green- 
ish hue ; hence the appearance of vomited bile (Exper. 55). 
The chief use of the bile is to digest the fatty parts of the 
food, upon which the gastric juice does not act. The bile 
also aids in separating the nutritious from the useless 
parts of the food.* 
The pancreatic juice is very much like the saliva. It is 
secreted by a long, narrow, flattened gland called the pan- 
creas, or sweet-bread, which lies deep in the cavity of the 
abdomen, just behind the stomach. It is often said to 
resemble a dog’s tongue in shape. The pancreatic juice 
finishes the work which the saliva began. It acts chiefly 
upon the starchy matters of the food which have escaped 
the saliva, and changes them into sugar. At the same 
time, however, it follows up the work of the gastric juice, 
and dissolves any albumens which have not been dissolved 
in the stomach (Expers. 57, 58). 
The inner surface of the intestines also pours in a liquid 
* Bile is an alkaline fluid; that is, it has the properties of baking-soda. 
We have tried, perhaps, to clean a bottle which has held oil. We put in 
some soda and warm water, and then shake the bottle. The soda breaks up 
the oil into tiny drops, which float round the creamy mixture. This is 
exactly what the bile does with the fatty parts of the food. In other words, 
it makes an “ emulsion.” Cod-liver oil is often mixed with other things, to 
disguise the fishy taste. This creamy mixture, known as an “ emulsion of 
cod-liver oil,” is a familiar sight in the drug-stores (Exper. 56). 76 
OUR BODIES. 
called the intestinal juice ; which, like the saliva, acts upon 
the starchy matters. At the same time, however, this 
juice acts as a solvent on any albuminoid matters or fats 
still undissolved. In fact, this intestinal juice has the 
properties of saliva, gastric juice, bile, and pancreatic 
juice all in one. Like a prudent housekeeper, Nature 
intends that this last digestive fluid in the digestive tube 
shall act upon all matters in the intestines still left undis- 
solved by the other juices, so that no part of the food may 
be wasted. 
The chyme thus acted upon by these different fluids 
has the appearance of a thick cream, and is called chyle. 
The muscles of the intestines, like those of the stomach, 
are almost continually at work. The whole intestinal tube 
is constantly moving in a manner somewhat resembling 
the motions of a worm ; and, all this time, it is squeezing 
and forcing forward its contents. In this way the whole 
of the food is acted upon by every part of the intestines in 
turn. 
69. Absorption. How the Blood feeds on the Food.— 
The soup-like mass which left the stomach under the 
name of chyme, has now been changed into a thick cream 
called chyle. Squeezed slowly along the intestines by 
the worm-like twistings of the muscular walls, most of the 
nutritious parts of this milky fluid is sucked up drop by 
drop by the lacteals, and poured into the current of the 
blood. The process by which the digested materials are 
taken into the blood is called absorption (Exper. 60). This 
is done chiefly by two sets of vessels, — first, by the lacteals, 
or lymphatics; second, by the blood-vessels. 
70. Absorption by the Lacteals and Lymphatics. — 
The innermost surface of the intestines is not smooth and DIGESTION. 
77 
shiny, like the outside, but shaggy, or, rather, has a 
velvety appearance. This is because the inner lining is 
crowded all over with millions of little tags, like very small 
tongues, hanging down into the inside of the intestines 
(Fig. 24). These hair-like projections are called villi, 
meaning “tufts of hair.” They are tiny affairs, about 
one-thirtieth of an inch long; and a five-cent piece would 
cover five hundred of them. These give the appearance 
of the pile on velvet. We are, of course, familiar with 
this appearance in tripe. 
Fig. 24. — Piece of Inner Surface 
of Intestine, showing the Villi. 
Fig. 25. — Villi greatly magnified. A, show- 
ing Lacteal; B, showing Artery, Capilla- 
ries, and Veins. 
In each one of these villi is a network of the finest 
blood-vessels, and a tube, or canal, called a lacteal (Fig. 25), 
so called from a Latin word meaning “milky,” and because 
it carries a white, milky fluid. Millions of these lacteals 
dip down into the intestines, like little root-fibres, and 
suck up from its creamy contents the fatty matters of the 
chyle. The lacteals, after passing through a number of 
glands — like way-stations on a railroad—in the abdo- 
men, unite into larger tubes, and finally open into a little 
sac, or bag, in the loins, called the “receptacle of the 78 
OUR BODIES. 
chyle” (Fig. 26). Leading upward from this is a tube 
called the thoracic duct, which carries the fluid upwards, 
along the backbone, and pours it into a vein in the neck. 
The thoracic duct is about eighteen inches long, and 
Fig. 26. — The Absorbent System of Man. 
about as large as a goose-quill. It acts as a kind of feed- 
ing-pipe, to empty the nutritive matter absorbed from the 
food into the blood-current. Absorption has really to do 
with a work of far wider character than that of merely 
keeping the lacteals busy. The lacteals are simply those DIGESTIOiY. 
79 
lymphatics which have their roots in the villi of the 
intestines. In all parts of the body, except the brain, 
spinal cord, eyeball, and tendons, we find thin-walled 
vessels busily at work taking' up, and making over anew, 
waste fluids or surplus materials derived from the blood 
and tissues generally. They seem to start out of the 
part in which they are found, like the rootlets of a plant 
in the soil. The- tiny roots join together, and make 
larger roots. They carry a colorless fluid called lymph, 
very much like blood without the red corpuscles. The 
tubes in which this fluid flows are called lymphatics. These 
tubes have rounded bodies at many points of their course, 
scattered along like depots along a line of railroad, called 
lymphatic glands. They seem to be factories to make 
over the lymph in some way, and fit it for renewing the 
blood. Most of the lymphatics at last unite with the 
lacteals, and empty their contents into the thoracic duct, 
Thus, again, Nature, like a careful housekeeper, uses up 
even the waste matters of our bodies, in providing them 
with nourishment. 
71. Absorption by the Blood-vessels.—Soluble sub- 
stances can pass through the delicate walls of the blood- 
vessels. The inner lining of the digestive canal, especially 
the small intestine, is rich in blood-vessels. Hence those 
parts of the food which have been made liquid, and capable 
of forming a soluble mixture with the blood, are absorbed 
directly by the small veins and capillaries ; although a small 
part finds its way into the lacteals. The emulsified fats, as 
we have seen, are mostly taken up by the lacteals. Cer- 
tain materials, dissolved by the gastric juice and ingested 
liquids, are taken up directly by the blood-vessels of the 
stomach. An enormous absorbing surface is provided in 80 
OUR BODIES. 
the small intestines, by the arrangement of the mucous 
membrane in folds, and by the countless numbers of villi, 
which is constantly absorbing nutritive materials through 
the myriads of its tiny blood-vessels. It is important to 
remember that all the blood circulating in the digestive 
organs, and taking up the soluble nutritive matters, must 
pass through the liver before entering the general cir- 
culation ; and from it the liver selects-and elaborates its 
secretion. 
The spleen is a reddish, soft, and pulpy organ. It is about live inches 
in its longest diameter, and an inch thick, and situated near the left end of 
the stomach, just under the ninth, tenth, and eleventh ribs. The use of this 
organ is not known. It has probably something to do with the formation 
of blood-corpuscles. In certain diseases, like malarial fever, it may reach an 
enormous size. Two other glands, the thymus and thyroid glands, known 
in the markets as the “breast sweet-bread ” and “ throat sweet-bread,” arc 
situated in the neck. They are regarded as appendages of the lymphatic 
system. Their use is not known. 
72. The Large Intestine.—The large intestine begins 
at the lower extremity of the small intestines, and con- 
sists of three parts, the ascending, the transverse, and the 
descending colon; the last of these being continued into 
the rectum (Fig, 3). This tube, which is about six feet 
long, first passes up the right side of the abdomen, then 
across under the liver and the stomach, and, lastly, de- 
scends on the left side of the abdomen to the rectum. 
As the food-mass passes along into the large intestine, 
almost every thing which is fit to be taken up has been 
absorbed. Some digestion may go on in the large intes- 
tine, but it is of little account. It is really a kind of 
passage-way, or temporary storehouse, for undigested and 
waste matter, which should be cast out of the body as 
speedily as possible. DICES TION. 
81 
73. How much to Eat.— The quantity of food needed 
to keep the body in good health, varies very much accord- 
ing to circumstances. The general principles are these : 
Fig. 27. — Blackboard Diagram of the Digestive Canal. 
Action is the law of every living' being. Waste attends 
action : hence, in the main, the supply of food must equal 82 
OUR BODIES. 
the waste of the body. The greater the amount of exer- 
cise, the more food is called for to supply the waste. 
During the time of growth, a still greater quantity is 
needed to build up new tissues : hence growing children 
generally have a good appetite and a vigorous digestion. 
The same holds good of persons getting well of some long 
and wasting sickness. The quantity required also depends 
very much upon one’s business. Those who work hard 
and long, either with the body or mind, as teamsters, black- 
smiths, farmers, doctors, and editors, need a goodly amount 
of nutritious food. Those who work indoors, as clerks, 
milliners, students, and book-keepers, can get along with a 
smaller quantity. In cold weather, or in cold climates, 
a greater quantity of “fuel-food” is necessary than in 
warm weather or in a tropical climate.* 
An appetite for plain, simple, well-cooked food is a safe 
guide to follow. Every person in good health and with 
moderate exercise should eat well: he should have a keen 
appetite for his food, and enjoy it. Young, growing, and 
vigorous persons should eat until appetite is fully satis- 
fied, provided they have enough exercise, both mental and 
bodily. It is easy to know when we are eating too much. 
An overworked stomach makes its condition known by a 
sense of fulness, uneasiness, drowsiness after meals, and 
* Incredible stories are told of tbe enormous appetite and craving for fat 
among the inhabitants of northern and the arctic regions. In the cold, dreary 
polar regions, the Esquimau consumes about twenty pounds of blubber-fat 
daily, besides drinking several quarts of train-oil. This fat is as neces- 
sary as the fuel to keep his inward fire going, or he would perish from the 
bitter cold. Lamp-oil and candles are eaten by this people with as much 
zest as our children would relish ice-cream and bananas. The Cossacks, it 
is said, drank all the oil in the lamps, and left the streets of Paris in darkness, 
when the Allies entered the capital after the defeat of Napoleon. 83 
DIGESTION. 
sometimes a real distress. If we keep on eating too much 
and too rich food, the complexion is apt to be muddy, the 
face more or less covered with blotches and pimples, 
the breath has an unpleasant odor, and the general look 
of the face is dull and unwholesome. 
74. What to Eat. — Food should be both nutritious and 
digestible. It is nutritious in proportion to its capacity to 
furnish suitable substances to be taken into the blood. 
Foods are digestible just as they are acted upon by the 
digestive fluids. Certain foods, as the vegetable albumens, 
are both nutritious and digestible. A man will grow strong 
and keep healthy on any of them.* 
We can safely eat some animal food every day, yet it 
is well to remember that the vegetable albumens supply 
all that is needed for the nourishment of the body. A 
strong, hearty person may eat half a pound or so of meat 
daily; yet he should take other foods, such as bread, oat- 
meal, beans, rice, and milk. These foods are all good, all 
cheap, all digestible, and all palatable. Vegetable foods 
are less stimulating than animal. Hence they are more 
suitable for children. Beef, pork, ham, oysters, and rich 
pastry should be sparingly given to children. The plainest 
and simplest diet is the best. It is much better for a 
child to go to bed on a supper of oatmeal, baked apples, 
or mush and milk, than hot biscuit, cake, pie, and fried 
* The splendid races of Northern India live on barley, wheat, millet, 
and rice, as their staple food. In Southern India, millions of people live 
on pease and rice. There have been many generations of the hardiest men 
in the world in the north of England and Scotland, who lived on oatmeal 
and milk. These men would literally live their lifetime without taking any 
other food except green fruits and vegetables. The Roman gladiator was 
trained on barlev; and the Roman soldier endured his long marches and 
severe fighting on corn boiled in water, when meat could not be had. 84 
OUR BOD/ES. 
meat. Parents cannot look too sharply after the food they 
give their children. This is especially important at the 
present day, when all kinds of strange devices are resorted 
to, to furnish the public with fanciful and tempting foods. 
Students must also look sharp to their diet. It is much 
better for them to begin a day’s study with a breakfast 
of oatmeal, stale bread, a soft-boiled egg, and a glass of 
milk, than strong coffee, sausage, and hot biscuit. 
75. When to Eat. — Th ree meals a day, from five to six 
hours apart, should be eaten. These should be arranged 
mainly according to one’s occupation. The stomach, like 
other organs, does its work best when its tasks are done 
at regular periods. Hence, regularity in eating is of the 
utmost importance. Eating out of meal-times should be 
strictly avoided, for it robs the stomach of its needed rest. 
P'ood, eaten when the body and mind are tired, is not well 
digested. Rest, even for a few minutes, should be taken 
before eating a full meal. It is a good plan to lie down, or 
sit cpiietly and read, fifteen minutes before eating. Severe 
exercise and hard study just after a full meal, are very 
apt to check digestion. The reason is plain : after a full 
meal, the vital forces of the body are called upon to he!]) 
the stomach digest its food. If they are forced, in addi- 
tion to this, to help the muscles or brain, digestion will be 
hindered, and a feeling of dulness and heaviness follows. 
This, in time, often results in the common form of ill 
digestion called “dyspepsia.” 
We should not eat for at least three hours before going 
to bed. When we are asleep, all the vital forces are at a 
low ebb, and digestion is difficult, if not impossible. 
We should make it a point not to omit a meal unless 
forced to do so. Children, and even grown-up people, DIGESTION. 
85 
often have the bad habit of going to school or to work in 
a hurry, without eating any breakfast. There is sure to 
be an “all-gone” feeling at the stomach before another 
meal-time. 
The state of the mind has a great deal to do with diges- 
tion. Sudden fear or joy, or unexpected news, may take 
away the appetite at once. Hence, so far as we can, we 
should laugh and talk at our meals, and drive away all 
anxious thoughts, and unpleasant topics of discussion. If 
hunger is a good sauce, so also is a jolly laugh. 
76. Howto Eat. — Eat slowly, and thoroughly chew 
the food. Do not take too much drink with the food. 
Our teeth were made to chew our food, and the saliva to 
moisten it, and help along digestion. If the food is well 
chewed, the saliva and the gastric juice act more readily. 
It is not only bad manners to eat rapidly, but it is a 
violation of the simplest law of digestion. If we take 
too much drink with our meals, the flow of the saliva is 
checked, and digestion is thus hindered. Rapid eating, 
with a great deal of drink to wash down the food, is 
almost sure to result in dyspepsia. Do not take the food 
and drink too hot or too cold. Such substances as very 
hot bread and coffee often injure the enamel of the teeth, 
and are slowly digested in the stomach. If the food and 
drink are taken too cold, undue heat is taken from the 
stomach, and digestion delayed. The natural temperature 
is about ioo° F. If we drink freely of ice-water or cold 
well-water, its temperature will fall about 30° ; and it will 
take half an hour or more for the stomach to regain its 
natural heat. Drinking freely of very cold water when 
the body is heated is a dangerous practice, and, aside from 
its ill effects on digestion, has occasionally resulted fatally. 86 
OUR BODIES. 
It is a poor plan to bolster a flagging appetite with highly 
spiced food and bitter drinks. An undue amount of pep- 
per, mustard, horse-radish, pickles, fancy meat-dressings, 
and highly seasoned sauces, may stimulate digestion for 
the time, but, used in excess, they soon weaken it. 
Proper Care of the Bowels. — Irregularity in eating, too much finely 
bolted flour, and not enough fruit and vegetables, rich pastry, negligence 
or carelessness in attending to a regular daily evacuation of the bowels, 
lead to the very common and distressing trouble known as constipation, or 
costiveness. As we grow older, this trouble generally grows worse. Many 
persons resort to all kinds of quack pills and medicines, which for the most 
part act only for the time, and do not remove the cause of the ailment. Such 
remedies do a deal of harm after a time, and are almost sure to leave the 
bowels in a worse condition. We must pay strict attention to the proper 
action of the bowels. The formation of a regular habit is of the utmost 
importance. The bowels can be trained to act at a certain time every day. 
Take great pains in eating coarse food, such as oatmeal, corn-bread, vegeta- 
bles, stewed prunes, dates, figs, etc. Drink a glass of water just after getting 
out of bed in the morning. Rochelle or Seidlitz powders may be needed at 
times: they are safe, and will do no harm. Vigorous muscular exercise, 
especially kneading the muscles of the abdomen, is a valuable help. If these 
things do no good, consult a physician before purgative medicines are used 
in a hap-hazard sort of way, simply because some friend urges their use. 
77. Cooking Food. — The question of cooking food is 
of the utmost practical importance. The best food may 
be spoiled by poor cooking. The great object in cooking 
is to make food tender and palatable, and hence easier to 
digest. It is not to change food, —for a potato is almost 
precisely the same after as before boiling, — but to make 
it more tender, so that it may be easily broken up by the 
teeth, and to improve its flavor. The whole matter of 
cooking is so intimately concerned with the health and 
welfare of the household, that it is very properly consid- 
ered to-day too important a subject to be discussed except 
in special books, and taught by special instruction. 87 
DIGESTION. 
78. Care of the Teeth.—The care of the teeth is an 
important matter. It is our duty to take the very best 
care of them, and to keep them as long as possible. Teeth 
are prone to decay. We may inherit poor and soft teeth : 
our ways of living may make bad teeth worse. If an ounce 
of prevention is ever worth a pound of cure, it is in keep- 
ing the teeth in good order. They should be thoroughly 
cleansed night and morning with a soft brush and warm 
water. Castile soap, and some simple tooth-powder with 
no grit in it, may be occasionally used. Dentists say that 
we should always cleanse the teeth before going to bed. 
The brush should be used on the inner or back side of 
the teeth, as well as on the front side. 
The enamel once broken or destroyed is never renewed. 
The tooth is left to decay, slowly but surely : hence we 
must be on our guard against certain things which may 
injure the enamel. Picking the teeth with pins and nee- 
dles is hurtful. We should never crack nuts, crush hard 
candy, or bite off stout thread, with the teeth. Metallic 
tooth-brushes, gritty and cheap tooth-powders, and hot 
food and drink, often injure the enamel. We should never 
use any of the tooth-powders and washes, especially adver- 
tised and secret preparations, “ warranted to harden the 
gums, and whiten the teeth.” Dirty and decayed teeth 
are a frequent cause of an offensive breath and a foul 
stomach. We should exercise the greatest care in saving 
the teeth. Tire last resort of all is to lose a tooth by 
having it extracted. The skilled dentist will save almost 
any thing in the shape of a tooth. 
79. Indigestion due to Alcohol. — A common and 
annoying result of drinking alcoholic liquors, especially 
in the morning on an empty stomach, is the injury to the 88 
OUR BODIES. 
process of digestion, often called “alcoholic dyspepsia.”* 
A person begins with a slight loss of appetite for break- 
fast, “spits cotton-wool," has a dull headache, feels a little 
sick at the stomach, and may vomit. He feels languid, is 
peevish and irritable, and is not comfortable until he has 
a drink of his customary liquor. After “ bracing up his 
stomach,” as he calls it, he feels more like eating. Hence 
arises the call for “morning bitters,” cordials, wormwood, 
and other things, to spur on the flagging stomach to digest 
the breakfast. After eating, the food does not digest well. 
There is a dull, heavy feeling of discomfort, and a belch- 
ing up of much wind from the stomach. With the old 
drinker of ardent spirits, there is in the morning a dry 
throat, trembling of the tongue, and an intense thirst 
which amounts to real suffering. 
80. Effect of Alcohol on the Stomach-Digestion. 
— Alcoholic liquors act as a mild or strong irritant of 
the stomach, just as they are taken raw or diluted. Their 
habitual use leads to most distressing forms of stomach 
disease. If we could look into the stomach, as Dr. Beau- 
mont looked into the stomach of Alexis St. Martin,f just 
after taking a drink of raw spirit, we should find that the 
* “Many cases of dyspepsia are due to alcohol, solely and wholly.” — 
J. Milner Fothergii.l, M.D. 
“Nothing with such certainty impairs the appetite and the digestive power 
as the continued use of strong alcoholic liquids.”— Pavy on “ Food'' 
t The process of gastric digestion was studied many years ago by Dr. 
Beaumont and others, in the remarkable case of Alexis St. Martin, a French- 
Canadian, who met with a gun-shot wound which left a permanent opening 
into his stomach, guarded by a little valve of mucous membrane. Through 
this opening the lining of the stomach could be seen, the temperature ascer- 
tained, and numerous experiments made as to the digestibility of various 
kinds of food. DIGESTION. 
89 
inner surface would be bright red when the alcohol 
touched it, and far more so than after taking ordinary 
food. Alcohol irritates the lining of the stomach, and 
dilates the tiny blood-vessels, just as brandy dropped into 
the eye would make it look red and watery.* 
Alcohol, like any other irritant, also stimulates the gas- 
tric juice to flow, and greedily takes up all the water it 
can get from this all-important digestive fluid. Large 
doses of alcohol also act directly on the gastric juice by 
precipitating its pepsin held in solution, thus checking the 
activity of this ferment. The injury to the liver from 
alcoholic excess also adds to the disturbance in the 
stomach. 
Now, when this alcoholic irritant is poured into the 
stomach for days, weeks, and even for years, it is no won- 
der that it is altered in its structure.f There is a chronic 
inflammation of the inner coats : the walls of the stomach 
become thicker and harder, and traces of ulcerations are 
often found. Because the stomach is unable to digest food 
properly, many other organs of the body suffer as a result. 
81. Effect of Alcohol on the Liver.—The liver is pecul- 
iarly liable to diseases due to alcoholic liquors. When 
* Dr. Beaumont made a study of the stomach of St. Martin after alcoholic 
excess. He tells us that the lining was overcharged with blood, at times 
drops of blood oozing from it, and that the juice of the stomach became 
thick, unnatural, and slightly tinged with blood. 
t “The structural alterations induced by the habitual use of alcohol, and 
the action of this agent on the pepsin, seriously impair the digestive power. 
Hence it is that those who are habitual consumers of alcoholic fluids suffer 
from disorders of digestion. Heartburn, water-brash, acid stomach, and a pe- 
culiar retching in the morning, are produced.” — Robert Bartiioi.ow, M.D. 
“Alcohol in any appreciable quantity diminishes the solvent power of the 
gastric fluid so as to interfere with the process of digestion instead of aiding 
it.” — W. B. Carpenter, M.D. 90 
OUR BODIES. 
alcohol is taken up by the blood-vessels of the stomach, it 
is carried directly to the liver, and filtered through this 
great organ before it reaches the heart. This, as we have 
been told, is a part of the portal circulation. Hence the 
poisonous effects of alcohol are strongly marked in 
the liver, especially among hard drinkers and in hot cli- 
mates. The blood-vessels of the liver are overworked, and 
the capillaries engorged with blood. This causes first an 
enlargement of the liver, and then a shrivelling of the sub- 
stance of the organ, together with a rough and “bunchy” 
surface. This, in medical language, is called cirrhosis* 
meaning tawny, or orange-colored, but in common phrase 
gets the name of the “hob-nail ” or “gin-drinker’s” liver, 
from its appearance.f Again, fatty decay (called fatty 
degeneration), due to alcohol, may take place in the liver; 
this makes the organ of great size, sometimes weighing 
from fifteen to twenty pounds : and one case is related of 
a drunkard’s liver that weighed fifty pounds. 
Collateral Reading. Mace’s History of a Mouthful of Bread; Mace's The 
Servants of the Stomach; Wilson's The Summer and its Diseases; White’s The 
Mouth and the Teeth, “ American Health Primers.” 
* “Cirrhosis of the liver is notoriously frequent among drunkards, and is, 
in fact, almost, though not absolutely, confined to them.”— Rohert T. Edes, 
M.D. 
t “ Alcohol acts on the liver by producing enlargement of that organ, and a 
fatty deposit, or the “hob-nailed” liver mentioned by the English writers.” — 
W. lb Carpenter, M.D. DIGESTION. 
91 
TEST QUESTIONS FOR REVIEW. 
1. Describe the digestive tube as a whole. 
2. What is meant by digestion? Name the various steps. 
3. What is meant by chewing? 
4. Describe the structure of a tooth. Mention the number and 
situation of the teeth, giving the names of each kind. 
5. What can you tell of the salivary glands and the saliva? 
6. Explain in some detail how we swallow food. 
7. What prevents food from getting up into the nose, and down 
into the windpipe ? Explain in full. 
8. Describe the stomach. 
9. What is the gastric juice ? How is it secreted ? Describe its action. 
10. What are the intestines? 
11. Describe the liver. The bile. The pancreatic juice. The 
intestinal juice. The action of each. The spleen. 
12. How is absorption accomplished? Describe the lacteals and 
the lymphatics. 
13. Explain absorption by the blood-vessels. 
14. Describe the large intestines. 
15. How much should we eat? Various circumstances affecting this 
question. 
16. What guides have we as to what we should eat? 
17. Describe in full when we should eat. 
18. How should we eat ? Explain in detail. 
j9. Cooking food. What do you know about it? 
20. Care of the teeth. Its great importance. Give details. 
21. Describe the indigestion due to alcohol. 
22. What is the effect of alcohol on the stomach ? 
23. What is its action on the liver? 92 
OUR BODIES. 
CHAPTER VI. 
THE BLOOD AND ITS CIRCULATION. 
82. U ses of the Blood. — Every child knows, that if he 
cuts or scratches his finger, or even pricks it with a pin 
or needle, blood flows. What is true of the finger, is also 
true of every other part of the body, except the hair and 
nails. The tiny blood-vessels go everywhere, through the 
muscles and nerves, over and within the brain, through 
every particle of every bone, — the blood flows every- 
where. Every little bit of bodily tissue is bathed with 
the blood. The blood makes every thing common as it 
flies from spot to spot. Wherever it goes, it has some- 
thing to bring, and something to carry away. The blood 
lives on the food we eat, and the tissues live on the nutri- 
tive material from the blood. The blood, in its ceaseless 
round, not only brings new material for repair, but it is 
also a kind of sewer-stream that drains off waste matters, 
and carries them to organs whose duty it is to cast them 
out of the body. 
83. How Blood is made up. — Blood, as it is drawn 
from the body, is a red, somewhat sticky, fluid, thicker 
than water, and apparently all of one substance. It is not 
so simple a fluid as it looks. If we let fall a small drop of 
freshly drawn blood upon a piece of glass, and examine it 
under a microscope, we shall see that this fluid is not all T1IE BLOOD AND 1'TS CIKCUJ.A TION. 
93 
of one substance. It consists of an almost colorless fluid 
called the plasma, and an enormous multitude of little 
bodies called corpuscles, floating- in the liquid. These cor- 
puscles are two kinds, red and white* (Expers. 61, 62). 
84. Blood Corpuscles. — The liquid blood, which looks 
to the naked eye as if it were perfectly 
red, is, «in reality, not red at all, being 
nearly as white as water. The red color 
is due to millions of little red corpuscles, 
which float about in the blood (Fig. 28). 
They are so closely packed, that the 
blood, as a whole, looks uniformly red. 
In the same way, a clear white glass 
bottle, filled with red beads and water, 
would look uniformly red at a short dis- 
tance. Imagine a small brook all alive 
with little red trout, and it would give 
some idea how the red corpuscles make 
the blood appear red. The red cor- 
puscles are by far the more numerous, 
there being about four hundred of them to one of the white 
corpuscles. In shape the red corpuscles are flattened circu- 
lar disks, resembling somewhat pieces of coin. They have 
something of the shape of an India-rubber air-cushion when 
blown up with air. They are not hard and solid, but resem- 
ble tiny pieces of red jelly rather than any thing else. 
Fig. 28. — Blood Corpuscles 
of Man. 
* The total quantity of blood in the 'body is about one-thirteenth of the 
weight of the body. Ifence a man of average size has from ten to twelve 
pounds of blood. Of this amount, water makes up nearly four-fifths: only 
about one-fifth consists of dry solids. The solids consist mainly of the cor- 
puscles, the albumen of the serum, and fibrine. The blood also contains a 
small quantity of minerals and salts. The most important are iron, potash, 
soda, phosphorus, and sulphur. These arc all essential to healthy blood. 94 
OUR BODIES. 
In size they are so very small, that, if we had fingers 
delicate enough to handle them, we could pack away some 
fifty thousand of them on the head of a pin. It is said 
that some five million of them will float round in a single 
drop of blood. Under the microscope, the flat sides of 
these disks stick to one another in rolls, piled together 
like so many gold dollars. 
The red corpuscles absorb oxygen in the lungs, and 
carry it for distribution to the various tissues of the body. 
Night or day, whether we are asleep or awake, millions of 
these tiny oxygen-carriers are busy as bees. The blood 
has been beautifully called ‘'the river of life.”* This is 
especially true of the red corpuscles. They may well be 
compared to a countless fleet of little boats which are 
constantly floating along “ the river of life ” in our bodies 
(Expers. 66, 67). 
The white corpuscles are slightly larger than the red, and 
are not flattened. As we watch them by means of the 
microscope, rolling and tumbling about, we see that at 
one time they are round like a base-ball, and of such a 
size that about twenty-five hundred of them would just 
reach one inch. Shortly afterwards, however, they change 
this form, and become pear-shaped, three-sided, and so on, 
in endless variety. The function of the white corpuscles 
is not certainly known. 
85. Coagulation, or Clotting. — If a basin of fresh blood 
is allowed to stand for a short time, it will separate into 
two parts : one, a sticky, jelly-like mass, called the dot, 
settles to the bottom ; the other, a straw-colored, watery 
* So dependent is all life on this fluid, that should the blood fail, for an 
instant, to reach the brain, all consciousness would at once cease; and if for 
a few seconds, life itself would cease. THE BLOOD AND ITS CIRCULATION. 
95 
fluid, called the serum, at the top. This change of the 
blood, after it is drawn from the body, into a jelly-like, 
semi-solid mass, is called clotting, or coagulation, of the 
blood. The watery part, or serum, as it is called, is blood 
out of which the corpuscles have been strained by the 
process of clotting. It is largely made up of water with 
albumen dissolved in it. If we try to boil serum, we find 
that we cannot do it. Before it boils, it “sets” into a stiff, 
solid mass, just like the white of a hard-boiled egg. 
The clot consists mainly of two substances, — the cor- 
puscles, and a network of white, tough, fibrous threads, 
called fibrinc. It is owing to the presence of fibrine that 
the blood clots. The corpuscles get snarled into the 
meshes of the fibrine, and thus the clot is formed. 
Fibrine may be seen by whipping fresh blood with twigs, 
to which it will stick in fine threads. The same thing 
can be done by beating up a bowl of fresh blood with an 
egg-beater, just as eggs are beaten for cake. 
The power of coagulation is of the most vital impor- 
tance. When a person receives a severe wound, he would 
bleed to death unless clotting set in. Nature in this way 
plugs up the wound with clots of blood, and prevents 
excessive bleeding (Expei-s. 63, 64). 
86. General Plan of Circulation. — If all the tissues 
and organs of the body stand in such constant need of 
blood, there must needs be some special machinery to fur- 
nish them with this vital fluid. We shall find this to be 
the fact. Let us begin to study this apparatus. In the 
first place, there is in the chest a powerful forcing-pump, 
called the heart, from which pipes are distributed to all 
parts of the body. One set of pipes, called arteries, carry 
the blood from the heart. Another set of pipes, called 
■veins, bring it back to the heart. 96 
OUR BODIES. 
The manner in which blood is made to flow through 
o 
vessels of the body may be compared to the way in which 
water is supplied to a city. The heart is the pumping- 
engine which forces the blood into the main pipes for the 
supply of the several districts. 
And as through the .city the great water-mains branch 
and subdivide into smaller pipes for the supply of districts, 
streets, houses, and rooms, so in the body the blood-vessels 
divide over and over again, to furnish a supply of blood to 
the smallest organs and the most minute parts of our bodily 
frame. The parallel ends here. The water supplied to 
the city does not return to the pumping-station, whereas 
the blood returns to the heart. When the blood has been 
pumped through every part of the body, and has given to 
it its nutritive supply, it receives from the tissues certain 
waste matters, the result of wear and tear. Hence the 
blood is no longer fit for nourishment. It is now more like 
a kind of sewer-stream laden with waste matters. These, 
in due time, are brought to certain organs, as the lungs, 
the skin, and the kidneys, and cast out of the body. 
87. The Heart. — The heart 'll a hollow, muscular organ, 
somewhat like a pear in shape. It is hung almost in the 
centre of the chest, above the diaphragm, partly over- 
lapped by the lungs, and opposite the breast-bone (Fig. 3). 
It is about the size of one’s closed fist, and is composed 
of involuntary muscular fibre. The heart is of a rounded, 
conical shape (some compare it to the shape of a cocoa- 
nut), and placed with the broad part uppermost, and the 
point slanting downwards and to the left, where it may be 
felt beating, between the fifth and sixth ribs. The heart 
is a double organ, with a partition-wall running down the 
centre from top to bottom, which separates the right side TILE BLOOD AND ITS CIRCULATION. 
97 
from the left (Fig. 29). Each of these sides has two 
hollow chambers, or cavities, — an upper one called an 
auricle, from its fancied resemblance to an ear; the other 
and lower one called a ventricle, 
or belly. Hence there are two 
upper chambers called auricles, 
and two lower chambers called 
ventricles. The heart is a muscle : 
hence it can contract. When 
each of its chambers contracts, 
blood is forced to flow' into the 
next chamber or a blood-vessel, 
as the case may be. The walls 
of the ventricles are stouter 
and stronger than those of the 
auricles, and those of the left 
ventricle are much stouter than 
those of the right ventricle. The 
right auricle opens into the right ventricle, and the left 
auricle into the left ventricle ; but there is no connection 
between one side of the heart and the other (Exper. 69). 
Work done by the Heart.—The heart is a wonderfully busy machine, 
pumping away without getting tired, night and day for eighty years or more 
perhaps, at the rate of seventy-two strokes every minute, over forty-three 
hundred times every hour, and nearly thirty-eight million beats every year. 
At each stroke, each ventricle pumps about six ounces, or nearly fifty tea- 
spoonfuls, of blood. About eighteen pounds of blood are moved every 
minute, or twelve tons every day. Hence it is calculated that the total 
amount of daily work done by the heart in a full-sized man is equivalent to 
the lifting of a ton weight to the height of two hundred feet. This is esti- 
mated to be about one-fifth of the whole amount of energy which a man puts 
forth in the form of heat and motion. While the cavities are filling with 
blood, and its muscles are relaxed, the heart has a brief rest: otherwise, it 
could not keep up its patient and tireless pumping of over four thousand 
tons of blood every year, from birth to death. 
Fig. 29.—Theoretical (Vertical) Section 
of the Human Heart. 98 
OUR BODIES. 
88. Valves of the Heart.—The passages between the 
auricles and ventricles are provided with little swing-doors, 
called valves, which have the power of effectually closing 
the opening (Fig. 30). These valves may be roughly com- 
pared to folding-doors or gates, which, by opening only one 
way, allow the blood to flow in that direction, and prevent 
its flowing in any other. They are made of thin, three- 
sided flaps of tough membrane, which hang down from the 
edges of the passage into the ven- 
tricles. The valve on the right 
side of the heart consists of 
three such flaps, and is called 
the three-pointed or tricuspid 
valve. That on the left consists 
of two flaps, and is said to look 
like a bishop’s mitre : hence it is 
called the mitral valve. The 
flaps fall back to let the blood 
flow from the auricles into the 
ventricles, but float up with the 
blood so as to prevent the return 
of the blood into the auricles. 
The valves are prevented from floating over into the 
auricles by delicate cords, which tie their flaps to the 
ventricles. 
Fig. 30. — Section of Left Side of Heart. 
89. Blood-vessels connected with the Heart.—The 
aorta, which is the largest artery in the body, springs 
from the left ventricle. It carries the bright, pure blood 
out from the heart. Four pulmonary veins open into the 
left auricle. Two of these veins come from the right lung, 
and two from the left lung. They all bring back to the 
heart the blood which has been purified in the lungs. TILE BLOOD AND ITS CIRCULATION. 
99 
Two of the largest veins in the body, called the superior 
and inferior vena cava, open into the right auricle. Both 
of these great veins pour into the right auricle the dark, 
impure blood, which has been collected in various parts 
of the body by the smaller veins. The pulmonary artery 
springs from the right ventricle. Soon after leaving the 
heart, it splits into two pipes : one goes to the right 
lung, the other to the left lung. This artery carries from 
the heart to the lungs the dark, impure blood, which has 
been brought to it by the great veins. Its entrance is 
guarded by valves, called the semilunar valves. These 
valves are three little pockets placed in a circle, with their 
openings turned towards the blood-vessels, shaped some- 
what like a half-moon (hence their name). 
90. The Arteries. — The arteries are the pipes which 
carry blood from the heart to various parts of the body. 
The word artery means “air-container.” The ancients, 
when they examined them after death, found them empty : 
hence they supposed that they contained nothing but air. 
The arteries may be regarded as branches of the aorta, or 
the main artery, which starts from the left ventricle of the 
heart. After leaving the heart, the aorta rises towards 
the neck, but soon turns, downwards, forming a curve, 
called the “arch of the aorta.” This great pipe then fol- 
lows down the spine, and divides into two main branches, 
which go to the legs. The large artery on the inside of 
each thigh is called the femoral. Two large arteries, called 
the carotids, spring from the arch of the aorta, and run up 
on each side of the neck to the head. Again, there are 
two large arteries, called the subclavian, meaning “ under 
the clavicle,” which branch off from the aorta, pass be- 
neath the collar-bone, and supply branches to the arms. OUR BODIES. 
100 
The largest branch, on the inside of the arm, is called 
the brachial. While the aorta is passing down the spine, 
it gives off branches to the important organs of the abdo- 
men. 
91. The Veins.—The veins are the return-pipes that 
bring the blood back to the heart. Unlike the arteries, 
which gradually grow smaller and smaller, the veins, start- 
ing from the capillaries, grow continually larger and larger. 
The veins of the legs travel upwards, becoming gradually 
larger by the addition of other branches in the abdomen, 
until at last all the united branches are 
joined in one great vein,* which empties 
into the right auricle of the heart. The 
venous blood from the head and arms 
flows back, and empties into the right 
auricle by another large vein.f 
Veins generally lie near the surface 
of the body, just beneath the skin. We 
may see them in almost any part of the 
body. 
The veins are abundantly supplied 
with little, pouch-like folds, or pockets, which act as 
valves, and allow the blood to flow only towards the 
heart (Fig. 31). If we press the fingers along one of 
the veins in the arm, towards the hand, we shall see a 
number of little knots, or swellings, here and there along 
the vein. The blood thus forced back fills the little pock- 
ets in the vein. Take away the finger, and the knots 
will at once disappear; because the blood is left free to 
flow towards the heart. 
Fig. 31.—Valves in Veins: 
a, vein slit open,’ show- 
ing semilunar valves; b, 
side view, showing the 
valves closed. 
* Inferior vena eava. 
f Superior vena cava. TITE BLOOD AArD ITS CTRCULA TIOAT. 
101 
The Veins compared io a Sewer System. — As we compared the arteries 
to the water-supply pipes of a great city, we may now compare the veins to 
another underground network of pipes, commonly called the “ sewer system.” 
The pure, wholesome water is brought by the aqueduct-pipes to each house. 
It is used, becomes filthy with dirt, waste, and all kinds of impurities: then 
the drains from each house carry it off before it can do any harm. The 
sewer-pipes from the houses unite with those of the streets: those of the 
streets unite at last into one great main sewer, which carries away this 
unwholesome river of impurities. The veins of the 
body resemble this sewer system. The pure, whole- 
some blood is brought by the arteries, is used by 
the tissues, and becomes foul with impurities. The 
veins are the drain-pipes of the body, to carry away 
this impure blood from the tissues, and spread out 
the ir contents into Nature’s great purifying reser- 
voir, — the lungs. 
92. The Capillaries. — Between the 
end of the smallest arteries and the be- 
ginning of the tiniest veins, is a very 
close network, like the finest lace, with 
the minutest little tubes for threads 
(Fig. 32). These little tubes are the 
capillaries, or hair-like vessels. In real- 
ity, they are as much smaller than hairs, 
as hairs are smaller than cables. So 
close-set are these tiny vessels, that we 
cannot prick any part of the skin, even 
with the smallest needle, without wound- 
ing one or more of them, and drawing 
blood. Some of them are so small that 
three thousand of them placed side by side would not, in 
their united width, measure more than one inch. The 
blood-disks can only pass through them in single file. 
The nutriment brought by the red corpuscles soaks 
through,the delicate, thin walls of the capillaries, and the 
Fig. 32. — Relations of 
Blood-vessels. 102 
OUR BODIES. 
tissues are bathed with the life-giving fluid of the blood. 
It is in this way that the tissues of the body are nourished, 
strengthened, and renewed. At the same time, the worn- 
out tissues are seized and burned up by the oxygen brought 
to them by the blood in the capillaries. The products of 
Fig. 33. — Diagram of the Circulation: the Arteries are shown white, and the Veins black. 
this burning are then caught up by the blood, and sent 
along to the veins, and so on to the heart.* 
93. Circulation of the Blood. — Let us begin at the 
* By the aid of the microscope, the circulation of the blood through the 
capillaries can be readily seen. This is studied in the transparent parts of 
animals, such, for example, as the web of a frog’s foot, the tail of a tadpole, 
or the wing of a bat. TITF. BLOOD AAV) ITS C/KCIV.A TTOAL. 
103 
right auricle (Fig. 33). We find two large veins busily 
filling the auricle with dark, impure blood, collected from 
all parts of the body. As soon as the auricle is full, it 
begins to contract. The blood cannot get back into the 
great veins because it is urged forward by the great vol- 
ume of blood behind it. The door opening into the right 
ventricle lies open, through which the blood flows until it 
is full. It now begins to contract : the tricuspid valve at 
once closes, and blocks up the way back to the right auri- 
cle. The blood rushes up the pulmonary artery through 
the semilunar valve, which stands open, This artery now 
carries the blood along to the lungs. The dark, impure 
blood is urged along narrower and narrower vessels until 
it reaches the capillaries of the lungs. Here it is, as it 
were, spread out to be purified. Exposed to the oxygen 
of the air, the blood gives up its impurities and its purple 
look. It takes up a great deal of the oxygen of the air in 
exchange ; and in a purified state, and of a bright scarlet 
color, it comes back to the heart by the pulmonary veins, 
which pour it into the left auricle. From the left auricle 
the blood is forced through the mitral valve into the left 
ventricle. As soon as the left ventricle is full, it begins to 
contract. The mitral valve at once blocks up 
the passage into the left auricle ; and the blood has no 
other way open but through the semilunar valve * into 
the aorta. 
The aorta and its branches, as we already know, dis- 
tribute the blood through every tissue of the body. From 
the tissues it is again returned by the veins to the right 
* The entrance to the aorta is guarded by a semilunar valve similar to 
that at the entrance of the pulmonary artery. 104 
OUR BODIES. 
auricle of the heart, and thus the round of circulation is 
continually kept up.* 
94. Sounds of the Heart. — As the heart is doing its 
work, it gives out certain sounds. If we put our ear 
against the chest of another person, over the heart region, 
we can easily hear two “pit-pat” sounds, one longer than 
the other. The longer is called the first sound of the 
heart, and is often compared vocally to the word “lubb;” 
that is, a prolonged sound. The second, which is sharper 
and more rapid, has been likened to the sound in the word 
“dup.” These two sounds are followed by a pause.f The 
first sound takes place when the walls of the heart con- 
tract, and force out the blood. The sharp, second sound 
is heard when the doors, or semilunar valves, shut. 
When the ventricles contract, the end, or apex, of the 
heart is tilted forwards and upwards, so that it strikes 
against the wall of the chest, on the left side, between the 
fifth and sixth ribs. This is known as the “beating” of 
the heart, which makes itself felt when unusually strong, 
as after severe exercise, as running and jumping. Sudden 
joy or fear will also make the heart beat quickly. Thus, 
while we cannot make the heart go slower or faster by 
* A drop of blood goes the grand round of the body in about twenty-two 
seconds; that is, while we are counting twenty-two, the blood flows through 
the right side of the heart, passes out into the smallest capillaries of the 
lungs, is purified, absorbs oxygen, is picked up again by the veins, and re- 
turned to the left side of the heart, to be driven out through the arteries into 
the capillaries, picked up again by the veins, and returned to the right side 
of the heart, — thus making the grand round. The entire blood in the body 
goes this complete circuit in about two minutes. 
t These sounds are often masked in diseases of the heart. After rheuma- 
tism, for instance, the valves may be hardened, or thickened, and thus give 
rise to other and new sounds. TIIE BLOOD AATD ITS CIRCULATION'. 
105 
any effort of the will, it is greatly influenced by the feel- 
ings.* It is quickened by mental excitement; while a sud- 
den shock to the mind may cause such a failure of the 
heart’s action as to cause fainting, and in very rare cases 
death itself (Expers. 71, 72). 
95. The Pulse, and what it may tell us. — If the 
finger be put over an artery which lies near the surface 
of the body, like the radial artery for instance, near the 
wrist, or the temporal artery, just over the temples, a 
regular throbbing, called the pulse, will be felt. This is 
the reason for it : when the left ventricle contracts, the 
blood is forced into the arteries, already full of blood, 
faster than it can pass through them. The elastic arteries 
are stretched by the extra blood ; and their rhythmical 
throbbing, keeping time with the heart-beat, is felt by the 
finger. In a healthy grown person, the pulse beats about 
seventy-two times a minute. In children the pulse is 
quicker than in adults, and slower in old age than in 
middle life. As the pulse varies very much in its rate 
and character in disease, it is to the trained touch of the 
physician a good index of the physical condition of his 
patient. 
96. Effect of Alcohol on the Circulation.—The 
flushed face of the drunkard, or even the moderate drinker, 
* People who work hard and are poorly fed, often suffer from an irregu- 
lar beating of the heart after some exertion, as walking up a steep hill, or 
going up-stairs, or sweeping. The feeling is as if the heart were going to 
“ jump out,” and is commonly known as “palpitation.” It is purely a dis- 
turbance of the functions of the heart, and has in no wise to do with heart- 
disease, from which people die so suddenly. Palpitation of the heart is 
occasionally caused by long-continued drinking of strong tea and coffee. To- 
bacco will often bring on the same trouble. Thus we have the “ tea-drinker’s 
heart ” and the “ tobacco heart.” 106 
OUR BODIES. 
is an every-day sight. It may seem to him and to others 
a sign of health, but it is really one of the many symp- 
toms of alcoholic poisoning. The alcohol has weakened 
the nerves which regulate the flow of blood in the ves- 
sels, thus allowing more blood to flow through them. The 
arteries are relaxed, the capillaries are engorged with 
blood, and the undue amount of blood stains through 
the skin. This action, — medical men call it “ conges- 
tion,”— we must remember, is not confined to the ves- 
sels near the surface of the body, but really extends to 
every organ and every tissue. 
97. How Alcohol gets into the Blood. —Alcohol 
passes into the blood by two distinct routes. When we 
take alcoholic liquor into the stomach, some of it at once 
soaks through the coats of the tiny blood-vessels with 
which the lining of the stomach is covered, and is carried 
into the blood-current by the portal circulation. Alcohol 
is also taken up by the lacteals, and is emptied into the 
blood through the thoracic duct. Now, although alcohol 
goes to the heart, to be sent to every part of the body in 
a roundabout way through the liver, it takes only a 
moment or two for it to get into the main blood-stream. 
A glass of strong drink soon “goes to the head,” as many 
people know; showing that its effects are rapidly pro- 
duced in the remotest tissues of the brain. The rapidity 
of this absorption depends upon the kind of liquor and 
the condition of the stomach. Alcohol thus taken into 
the blood is flushed everywhere, — into each fibre, mem- 
brane, and tissue. It fills and saturates each vital organ, 
— flesh, brain, heart, liver, lung, kidney, skin, and secret- 
ing-apparatus. Wherever there is blood naturally, there 
is now blood mingled with alcohol. THE BLOOD AND ITS CIRCULATION. 
107 
98. Effect of Alcohol upon the Heart. — The nerves 
have now lost their grip on the blood-vessels, and hence 
the heart has less resistance to meet. Consequently it is 
forced to beat faster, and work harder, to fill the dilated 
vessels with blood.* This increased frequency of the 
heart’s stroke entails increased labor, more wear and tear, 
and less rest for this vital organ. With this increased 
action, there is, to be sure, a flushing of the face, a feel- 
ing of warmth, and other marks of increased activity ; but 
it is not lasting. This effect of alcohol is often called 
its stimulant action. It is not so much a real stimulant 
as merely a whip to spur the heart for the time to beat 
faster. It is more exact to call it the beginning of the 
intoxicant or poisonous power of alcohol. 
Collateral Reading. The Heart and its Function, “ Health Primer.” 
TEST QUESTIONS FOR REVIEW. 
1. Of what use is the blood ? 
2. How is the blood made up? 
3. What is the total quantity in the body? 
4. How does it look? its color? 
5. How does blood look under the microscope ? 
6. Describe the red blood corpuscles. 
7. Describe the white blood corpuscles. 
8. What is meant by the coagulation of blood ? 
* The late Dr. Parkes, an eminent English authority on matters of health, 
calculated that this extra work of the heart, when alcoholic liquors were 
consumed, amounted to the lifting of twenty-four tons of extra blood one 
foot high,each day, — about twenty per cent of additional work. 108 
OUR BODIES. 
9. How may you compare the flow of blood circulation to a force- 
pump? to the water-system of a great city? 
10. Describe the heart. 
11. Explain the terms auricle, ventricle, valve. What can you tell 
of the work done by the heart ? 
12. Describe the action of the valves of the heart. 
13. Name the blood-vessels connected with the heart. Tell with 
which part of the heart each is connected. 
14. Describe in a general way the differences between the veins and 
arteries. 
15. Describe the aorta. Some of its great branches. 
16. What large arteries can you locate? 
17. What are the veins-? Describe their valves. 
18. To what may the venous system be compared? 
19. What are the capillaries? their use? 
20. Give a general description of the circulation of the blood through 
the body. 
21. How much time does it take? 
22. Describe the sounds of the heart. 
23. What is meant by palpitation of the heart? 
24. What is the pulse? What may it tell us ? 
25. What is the general effect of alcohol on the circulation? 
26. How does alcohol get into the blood ? 
27. What is the effect of alcohol upon the heart? BREA THING. 
109 
CHAPTER VII. 
BREATHING. 
99. Why we breathe. — Night and day, without one 
moment’s rest, from the first to the last instant of our 
lives, we arc breathing. About eighteen times every 
minute, more than twenty-four thousand times every day, 
and many millions of times in a lifetime of seventy years, 
we draw in, and send out again, our breath. Most of the 
time we do not think any thing about it. We eat, talk, 
work, and sleep; and all this time our breathing goes 
quietly on. Breathing is the plainest sign by which we 
judge a person to be alive who lies otherwise motionless 
and insensible. Though we can hold our breath for a 
short time, yet, after a few seconds, we begin to feel un- 
comfortable. 
In speaking of food and the blood, we have learned, that, 
without food and fresh air, the burning, or oxidation, which 
is slowly going on in our bodies all the time, would soon 
flag, and we should, after a while, die for want of them. 
Hence we must have oxygen to keep up the burning. We 
get the oxygen from the air we breathe. Again : we have 
learned that the dark, impure, and venous blood was sent 
to the lungs from the right ventricle, and was returned to 
the left auricle as pure arterial blood of a bright red color. 
The blood has got rid of its waste matters, and become 110 
OUR BODIES. 
pure. In brief, the blood has been oxidized in the act of 
breathing. Hence in breathing we have two objects in 
view, — first, to bring a fresh supply of oxygen to the 
blood, by means of the lungs ; and, second, to get rid of 
carbonic acid and waste matters, taken up from the tissues, 
and brought to the lungs by the blood. 
100. The Air-passages. — The air is drawn into the 
lungs through the mouth, nostrils, and windpipe. The 
nostrils are really the passage-ways for the air, and warm 
the air somewhat before it goes into the lungs. The 
air passes from the nostrils into the windpipe, or trachea. 
The windpipe is a hollow tube about four inches long, and 
is protected on the front and sides by stout rings of gristle. 
But for them the windpipe would close with the slightest 
pressure, and cut off the breath. The top of the wind- 
pipe is protected by a trap-door kno\Vn as the epiglottis. 
When food is swallowed, this little door shuts tight, and 
keeps it out of the air-passages : otherwise the food would 
go the wrong way, and cut short our breath. When we 
breathe, the lid lifts up (Figs. 53, 54, 55). The upper part 
of the windpipe is a kind of box called the larynx, or organ 
of voice. In this box — which in some persons is very 
prominent, and the front of which is commonly called 
“Adam’s apple ” —are the vocal cords. These cords are 
not strings, but rather elastic strips, with free edges which 
can be made tight or slack. As the air goes to and fro 
from the lungs, through the narrow slit between them, 
called the glottis, it sets the cords to vibrating, and thus 
makes the sound of the voice. See chap. xii. (Exper. 80). 
The windpipe, after entering the chest, divides into two 
branches called bronchi, or windpipe tubes, sending one to 
each lung (Fig. 34). These, again, divide into smaller BREA THING. 
111 
tubes called bronchial tubes, Fach bronchial tube divides 
again into smaller branches, these again into smaller, and 
so on to the tiniest twigs, as 
fine as the hairs of our head. 
If we only remember that all 
these tubes, great and small, 
are hollow, we may compare 
the whole system to a short 
bush or tree growing upside 
down in the chest, of which the 
windpipe is the trunk, and the 
bronchial tubes the branches 
of various sizes.*' 
101. The Lungs. — The 
lungs are two large, pinkish, 
spongy organs, which sur- 
round the heart, and fill up 
all the rest of the chest-cavity 
(Fig. 35). The right lung is 
the larger of the two, and has 
three parts, or lobes. The left 
lung has only two lobes (Fig. 3). The inside structure of 
the lungs is really a mass of air-passages, arteries, veins, 
Fig. 34. — Windpipe and one of the 
Lungs. 
* The inside walls of the windpipe and air-tubes are lined with a mucous 
membrane, which gives out a thick, slimy substance called mucus, to keep 
the passages moist. This membrane is covered with thread-like processes 
called cilia. They are not unlike fine hairs, and resemble somewhat the 
pile on velvet. They wave to and fro, like a field of grain in a breeze. The 
motion is always upwards and outwards towards the mouth. They make 
one continuous brush, which is ever busy sweeping out the air-tubes. They 
sweep up the particles of dust and mucus from the tubes, and brush them 
out of the pipes with a sudden blast of air which we call coughing. These 
tiny cilia are simply the dusters which Nature uses to keep the air-passages 
neat and clean (Fig. 36). 112 
OUR BODIES. 
and capillaries. Imagine a thick, short tree crowded with 
leaves : imagine the trunk and branches, small and great, 
down to the smallest twigs, are hollow. Suppose that the 
leaves themselves were tiny 
bladders, blown up, a n cl 
stuck on to the smallest 
hollow twigs, and made up 
of some delicate, but very 
clastic, substance. Around 
such a framework of hollow 
branches, called bronchial 
tubes, and hollow, elastic 
bladders, called air-cells, is 
wrapped a finely woven net- 
work of arteries, veins, and 
capillaries. Imagine a child’s 
ball covered with a fine net- 
work of red and blue yarn. 
We can form some idea of the number of the air-cells 
when we remember that 
the end of the smallest bron- 
chial tube, often called a 
lung-sac,* is said to hold 
about seventeen hundred 
air-cells (Fig. 37). The lungs, 
then, consist of millions of 
these tiny air-cells, packed closely together, each air-cell 
communicating with the windpipe, and so with the atmos- 
phere in which we breathe (Expers. 73, 74, 75, 76, 77). 
Fig. 35. — The Lungs and Heart 
(viewed in front) 
Fig. 36. — Ciliated Epithelial Cells from 
the Finer Bronchial Tubes. 
* Each lung-sac bears some resemblance to a bunch of grapes, and is so 
small that forty of them would barely reach an inch. Just as the bunch of 
grapes, however, contains a large number of single grapes, so every lung-sac 
consists of a large number of separate air-cells. BREA THING. 
113 
The chest is lined, and the lungs covered, with a smooth, 
delicate lining, called thopleura. These two surfaces rub 
against each other when we breathe. This lining secretes 
a fluid which keeps the parts always moist, and prevents 
their chafing one on another.* 
102. H ow we breathe. — If we put both hands on the 
two sides of our own chest, and breathe in deeply, we 
feel that the act has carried the hands farther apart. 
Again, if we put one hand across 
the middle of our own chest, we 
feel that it is carried forward 
every time we breathe in, and 
is returned to its place as we 
breathe out. Further, if we pass 
a tape-measure round the chest, 
and draw it tight when we breathe 
out, we find that the tape must be 
let out two or three inches when 
we begin to breathe in. If we 
breathe in and out with a great 
deal of force, the changes are more marked. Hence there 
are two movements in breathing, — one in which the cavity 
of the chest is made larger in all its dimensions : this is 
when we breathe in air, and is called inspiration. The 
other movement is one in which the chest-cavity is made 
smaller in like manner : this is when we breathe out air, 
and is called expiration. The means by which the air is 
breathed in and out of the lungs makes up the mechanism 
of breathing. Let us try to understand the process. 
Fig. 37.—The Air-cells and Bron- 
chial Tubes of the Lungs. 
* When the pleura becomes inflamed, it gives rise to the disease com- 
monly known as “ pleurisy.” OUR BODIES. 
114 
The cavity of the chest is a closed air-tight chamber, 
whose only opening is the windpipe. The pressure of the 
air in the air-passages keeps the lungs stretched out so 
as to fill this cavity. Imagine now such a chamber as 
this to have a kind of false floor, capable of sliding up and 
down. When the floor was pulled down, the cavity would 
be enlarged ; and the pressure of the air would cause 
the elastic lungs to expand to a greater extent to fill up 
the extra space. 
When the floor was raised again, the cavity would be 
diminished; and the stretched lungs, being diminished 
also, would give up the extra quantity of air which they 
took in. 
Suppose these two movements were performed at regu- 
lar intervals. Then, every time the floor was pulled down, 
there would be a rush of air down the air-passages to the 
lungs ; and, every time it was raised, that same quantity 
of air would be driven out of the lungs again. 
This is exactly what happens during the process of 
breathing. The bottom, or floor, of the chest, is formed, 
as we know, by a large, flat muscle called the diaphragm 
(Exper. 79). 
When this muscle contracts, it is pulled down, and the 
cavity of the chest is enlarged. When it relaxes, and con- 
sequently rises again, this chamber is diminished. These 
two up-and-down movements of the diaphragm are the 
chief movements in ordinary, quiet breathing. 
The cavity of the chest, however, is enlarged in another 
way. The walls of the chest are formed by the ribs, which 
encircle it so as to join the breast-bone in front. Tire 
spaces between the ribs arc occupied by a set of strong 
muscles called the intercostal muscles. BREA THING. 
115 
One set of these intercostal muscles contracts, and pulls 
up the ribs, which are fastened to the backbone behind 
by a joint. When the ribs are raised, they push out the 
breast-bone in front; and thus the cavity of the chest is 
enlarged all round. This enlargement, by means of the 
side walls, takes place at the same time as the diaphragm 
descends, so that the chest is enlarged on all sides. An 
extra quantity of air then rushes into the lungs, and we 
get an inspiration. 
Immediately following the inspiration, the diaphragm 
relaxes, and, of course, rises; and, at the same time, 
another set of intercostal muscles begins to pull the 
ribs and breast-bone down. These combined movements 
diminish the cavity of the chest, and consequently the 
same quantity of air is driven out. This makes an expira- 
tion (Exper. 78). 
103. Changes in the Air from breathing. — The air, 
or atmosphere, covers the earth on which we live to a 
height of some fifty miles. It is a mixture of two gases, 
— oxygen and nitrogen,—in the proportion of one part of 
the former to two of the latter. Oxygen is the active gas, 
the feeding and warming gas, the life-giving principle of 
nature. Nitrogen is mixed with it, lest the oxygen should 
be too strong for us, and burn us away too fast. In short, 
Nature dilutes the air for us with nitrogen. If we exam- 
ine the air just as it enters the lungs, and again after it has 
passed through them, we shall find, that, while the bulk 
is almost exactly the same, the quality has been changed. 
It has left behind about one-twentieth of its oxygen, and 
taken in exchange for it nearly the same quantity of car- 
bonic acid. About twenty cubic inches of air pass in and 
out of the lungs with every breath, and about three hun- 116 
OUR BODIES. 
dred cubic feet every twenty-four hours ; amounting to 
the contents of sixty barrels. Let us now see how this 
exchange takes place. The air and blood are not in 
contact. The coats of the air-cells separate the oxygen 
and carbonic acid. Now, experiments carried on outside 
of the body prove that gases can pass through delicate 
membranes. If a bladder is filled with oxygen, and then 
hung up in a bottle filled with carbonic acid, the two 
gases will mix with each other. The oxygen will pass 
out through the walls of the bladder, and the carbonic 
acid will pass in. This is called the diffusion of gases, 
and is said to occur according to a law of nature. This 
is practically what happens in our lungs every moment of 
our lives. Thus, there is an exchange, but no robbery. 
The red corpuscles of the blood exchange a noxious gas 
for one which gives them new life and energy. The blood, 
thus renewed, travels to the left side of the heart, is 
pumped out through the aorta, and distributed to every 
tissue and organ of the body. We may, in brief, look 
upon the lungs as a kind of market-place or exchange, 
where two merchants — the blood and the air — meet to 
exchange their wares. The air, as it leaves the lungs, 
is saturated with watery vapor. This is seen when we 
breathe on the bright steel blade of a pocket-knife, a 
mirror, or any cold, polished surface. As we all know, 
the surface becomes covered with a thin film, or minute 
drops of water. In cold weather this moisture becomes 
visible with each expiration. Air, as it leaves the lungs, 
is much hotter than the surrounding air. It is generally 
about 98° F. For this reason, on a cold day we blow 
our fingers to warm them. The air also contains a small 
amount of decaying animal matter. Every one knows the BREA THING. 
117 
unpleasant odor of the air in rooms in which many per- 
sons have been closely shut up. 
104. Carbonic Acid and its Poisonous Effects. 
Carbonic acid, in its pure state, acts as a deadly poison. 
An excess of it in the air produces poisonous effects. The 
air we breathe out contains four parts in a hundred of this 
gas. Increase this to ten parts, and it will prove a deadly 
poison to warm-blooded animals. In smaller quantities, 
this gas produces labored breathing, dizziness, headache, 
and a general stagnation of the life-processes.* 
In the mines, this gas becomes the dreaded “choke- 
damp.” It is dangerous oftentimes to cross over a vat in 
which beer is actively fermenting ; for the air over the vat, 
loaded with carbonic acid, is utterly unfit to breathe. 
Persons bent on suicide inhale the carbonic acid from a 
little charcoal burning in a closed room. 
In the open air we rarely suffer any ill-effects from car- 
bonic acid, for the simple reason that Nature is always 
mingling the gas with the oxygen by means of the winds 
and the rains. A fresh supply of pure, life-giving air is 
thus furnished in the greatest abundance (Expers. 81, 82, 83). 
Like a prudent manager, Nature utilizes the carbonic 
acid as the life-food of the vegetable creation. The trees, 
the plants, and the grasses make, as it were, oxygen out 
* This same deadly gas sometimes flows naturally from the earth. Some 
of us have heard of the “ Valley of Poison ” in the island of Java, of which 
fabulous stories are told by travellers. This gas is very abundant in this 
valley, and from its weight sinks to the ground, where may be seen, it is 
said, the skeletons of birds and animals, which have been suffocated in their 
attempt to cross this death-trap. There is a lake in Italy called Avernus, 
meaning “without birds,” surrounded by thick woods. As the story runs, 
birds, in flying over the lake, are poisoned by the carbonic acid, and fall dead 
into the water. 118 
OUR BODIES. 
of the carbonic acid ; while we make carbonic acid out of 
the oxygen taken into the lungs. 
105. Impurities in the Air.—While carbonic acid and 
the waste animal matter given off with it from the lungs, 
are the most common impurities, there are many other 
things which make the air unwholesome. The poisoned 
air due to cesspools, drains, and sewers, is often a fre- 
quent source of disease. Sewer-gas is a fruitful source 
of certain diseases, as typhoid-fever and diphtheria. The 
foul air from chemical works, bone and soap factories, 
and many other manufacturing places, is more or less 
hurtful to health. Even the dust in our rooms may carry, 
it is thought, the germs of disease. 
Certain occupations shorten life by exposure to air 
loaded with impurities. Thus, there is the “miner’s con- 
sumption,” or “black lung,” due to the dust breathed into 
the lungs, acting like so many little splinters in the deli- 
cate air-cells. Those who work on steel, emery, pottery, 
etc., also suffer from the irritating dust floating in the air. 
Other impurities are highly injurious to the lungs, as the 
dust in match-factories, white-lead works, copper and brass 
founderies, and arsenic in wall-papers. Unwholesome as 
the air may be in the workrooms of many trades, the real 
danger, after all, and that which should be of more concern 
to the public generally, arises from the slow and unsus- 
pected effects of breathing air which has already been 
breathed. The peril is in our own living-rooms, our bed- 
rooms, our schoolrooms, halls, vestries, theatres, and 
churches. 
106. How to Ventilate. — The best way to rid the air 
of its impurities is by some suitable system of ventilation. 
To ventilate a place is to cause pure air to flow through it. BA'FA THING. 
119 
In other words, it is some practical plan to keep the air 
pare and wholesome. Do our best, and we cannot keep 
the air of any inhabited room as pure as the atmosphere 
outside. 
The object aimed at in ventilation, is to give an outlet 
to impure air, and an inlet to that which is pure, fresh, and 
moist. Remember that it is not at all necessary that air 
should be cold to be pure. The required amount of fresh 
air should be moved evenly through the room or building 
with a gentle current, and without a draught. An open 
fireplace is a healthy, safe, but not economical, way to heat 
and ventilate a room. Stoves in a room soon dry the air, 
unless fresh quantities from outside are constantly sup- 
plied. When rooms are warmed by heated air from 
furnaces, the warm air should enter through registers in 
or near the floor, on one side of the room ; and impure air 
should escape through outlets in or near the ceiling, on 
the other side. 
Children should be trained from infancy to sleep with 
the windows partly open for the greater part of the year. 
Adult people in vigorous health should gradually learn to 
do the same. Even in the coldest weather, some simple 
apparatus to let in fresh air is as good as any. Raise the 
window a few inches, and put in a piece of board under 
the lower sash. Pure air will enter where the two sashes 
overlap. A common window-screen, cut to the proper size, 
and covered with flannel instead of wire, will let in plenty 
of air without draught, and is suitable for cold weather. 
Again, fit an elbow of common stove-pipe into a board of 
the right size, and put it under the raised sash, with a 
damper to regulate the current of air. These and other 
contrivances are easy to make, and cost but little. They 120 
OUR BODIES. 
answer the purpose even better than those that are more 
costly and complicated.* 
107. Ventilation of Schoolrooms. — Special pains must 
be taken to ventilate schoolrooms. Pupils are sure to be 
listless, uneasy, dull, and sleepy when the air is not whole- 
some. Children may be comfortable in a well-aired room 
at 66° F., but it is very easy to let the temperature run 
up to 85° before it is noticed. Whatever the apparatus 
for ventilation may be, the doors and windows should be 
opened before and after each session, at recess, and during 
gymnastic exercises. Weakly children, those liable to 
croup, those easy to catch cold, and other ailments, must 
be carefully looked after in the mean time. Never allow 
draughts of cold air to fall directly on the heads of chil- 
dren. Guard the air of the schoolroom from the foul air 
arising from closets, outbuildings, sinks, cesspools, and all 
other possible sources of ill-health. 
108. Why the Body is Warm. — Every one knows that 
the surface of the body feels warm. Hold the fingers 
in the mouth, and we find it warm. Put a thermometer, 
made for the purpose, in the armpit, or in the mouth, for 
* The temperature in our living-rooms for this climate should be kept 
at about 68° to 70° F. Most of our rooms are apt to be overheated, 
or unequally heated, especially during cold weather. Any person, child or 
adult, may become tender and delicate in a short time by getting used to 
overheated rooms. The temperature of the sick-room depends somewhat 
upon the age of the sick person, and his disease. A temperature of 40° F. to 
50° may be suitable in typhoid-fever, while 8o° may be necessary for an aged 
person suffering from rheumatism. The greatest care in keeping any sick- 
room supplied with pure, fresh air, and at the proper temperature, is neces- 
sary. Old people generally need a higher temperature than the young and 
vigorous. The warm air in our living-rooms, to be healthy, should be kept 
moist. A shallow pan of water put on the stove, or near a register, answers 
every purpose. BREA THING. 
121 
five minutes, and it will register about 98° F., even in the 
coldest day of mid-winter. This is the natural heat of a 
healthy person ; and it rarely varies more than a degree 
or two, except in disease.* This heat is produced in just 
as simple a manner as that which results from a common 
fire or a lighted candle : it is the natural result of the 
process of combustion. We are warm ourselves, because 
we are burning away bit by bit, just as a candle does ; 
that is to say, by the union of carbon, or charcoal, with 
oxygen. There is only this difference : we burn wet mate- 
rials (the moist tissues), and do not make a flame, or give 
a light. We take our coal or tallow in the shape of starch, 
sugar, and fat, and get the oxygen from the air we breathe. 
A steam-engine at work is warm because all the energy 
set free from the fuel burned is not turned into mechani- 
cal work, but some of it appears as heat : so it is in our 
bodies. Our muscles, our organs, in fact, every tiny cell, 
are busy at work ; and their substance is slowly burned at 
a low temperature. Every time we move, feel, think, or 
exercise any function, this oxidation, or burning, is going 
on. Some of the energy thus set free by this slow com- 
bustion shows itself as heat, which helps keep the body 
warm, and at its natural temperature. Thus, animal heat 
is produced, and life maintained. Our bodies are working 
at a temperature higher than the surrounding air, except 
in the hottest weather : hence there must be a loss of 
* The rate of combustion may be much increased or lessened in various 
diseases. In pneumonia, typhoid-fever, and blood-poisoning, the physician 
may note a temperature of 105° F., or even more: hence the fever-patient 
says repeatedly that he is “burning up” with fever, and eagerly drinks 
all the cold water which is given him, and calls for more in a few minutes. 
In other diseases, such as cholera, there is a notable fall in the natural 
temperature. 122 
OUR BODIES. 
heat nearly all the time. Therefore we must keep making 
heat all the time, to make up for the continual loss. Be- 
sides this loss by radiation, as it is called, considerable 
moisture is got rid of by the skin in the form of vapor or 
sweat. The evaporation of this moisture from the skin 
acts as a kind of regulator to keep down the excess of 
heat. 
109. Effect of Alcohol upon the Lungs. — Alcohol in 
excess tends to bring on inflammation of the lung-tissues, 
and hence lessen the breathing-capacity. The apparatus 
called the “spirometer,” used by life-insurance companies 
to test the breathing-capacity of lungs, often detects 
the dram-drinker by his failure to reach the natural 
breathing-capacity. The wheezy, broken speech of the 
drunkard is partly due to this condensation of the lung- 
tissue. Again, the repeated dilatation of the lung-capil- 
laries tends to make the habitual user of alcohol more 
liable to attacks of severe cold, pleurisy, and pneumonia, 
after making due allowance for the exposure to cold and 
wet, so common with the intemperate.* 
110. Alcohol and the Bodily Heat. — Soon after taking 
even a small quantity of alcohol, there is a general feeling 
of warmth over the surface of the body. The body is not 
really warmer, but the skin feels warmer. On the con- 
trary, we are really colder; because heat is more rapidly 
lost by radiation and evaporation from the surface. The 
skin is warmer after taking alcoholic liquor : because the 
nerves that regulate the hair-like blood-vessels on the sur- 
face, being weakened, lose their grip ; hence more blood 
* According to some good medical authorities, the excessive use of alcohol 
works such a change in the lung-tissues as not unfrequently to lead to a form 
of consumption, called “alcoholic phthisis.” UREA THING. 
123 
is sent from the central parts of the body to the surface. 
There is no real increase of heat : the surface is warmed 
for the time at the expense of the inner and deeper por- 
tions of the body. This surface warmth is now rapidly lost 
by radiation, and the general heat of the body is lowered 
below its natural temperature. The bodily temperature 
is regulated by the surface circulation ; and when this con- 
trol is lost, as it is by alcohol, the body is cooled by the 
undue amount of blood carried to the surface. 
Experience has proved, time and time again, that alcohol 
lessens our power to endure extremes of heat or cold for 
any great length of time. Arctic explorers strictly forbid 
the use of alcoholic liquor among their men. It has been 
proved that the exposure to severe cold can be endured far 
better without alcohol. So well is this bad effect of alco- 
hol known by the people of the coldest regions of Canada, 
that they will seldom take even a single glass of spirits 
when exposed to severe cold. 
Army life is perhaps the best possible test. It is the 
almost universal experience of British army officers who 
have led their men through the recent campaigns in the 
hottest parts of Egypt, and who have given special study 
to the question, that alcohol, so far from being an aid to 
endure severe exertion, and to resist great extremes of 
heat, acts as a positive injury. 
Collateral Reading. Wilson’s Health and Healthy Homes, chap. vii.; 
Wilson’s Handbook of Hygiene and Sanitary Science. 124 
OUK BODIES. 
TEST QUESTIONS FOR REVIEW. 
1. What is the object of breathing? Why do we breathe? 
2. Describe the air-passages. 
3. How are they lined and protected? 
4. Give a short description of the lungs. 
5. What is the pleura ? 
6. Describe the mechanical movements of breathing. How do we 
breathe ? 
7. Describe the changes in the air from breathing. 
8. How may we compare the lungs to a market-place ? 
9. What is carbonic acid? where found? its poisonous effects? 
10. What impurities may exist in the air? 
11. What are the chief dangers from impure air?' What are the 
practical effects ? 
12. Why and how should we ventilate? Give some practical plans. 
13. The ventilation of schoolrooms, — why and how is it done? 
14. What is the proper temperature of our living-rooms ? Explain in 
some detail. 
15. Animal heat. How is the body kept warm ? 
16. Explain and illustrate this slow combustion, or oxidation. 
17. What is the effect of alcohol upon the lungs? 
18. Explain in detail the action of alcohol upon the bodily heat. 
19. Give illustrations from the text and your own reading. THE SKIN. 
125 
CHAPTER VIII. 
THE SKIN. 
111. The Skin. — The skin is the outside covering of 
the body. The parts underneath are very tender and sen- 
sitive. We all know how painful and tender is any part 
of the body when the skin has been torn, cut, blistered, 
burned, or otherwise hurt by accident. Kind Nature has 
given us a strong, elastic, and tight-fitting outside gar- 
ment. It is easily kept clean, and never wears out. It 
is soft and thin, yet strong enough to enable us to come 
in contact with objects without pain or inconvenience. 
The skin is richly supplied with nerves and blood-vessels, 
so closely netted together that it is next to impossible to 
prick the skin anywhere with the point of a needle without 
drawing blood, and feeling pain. 
112. The Scarf-skin. — The skin is made up of two lay- 
ers. The outer one has neither blood-vessels nor nerves, 
and is called the scarf-skin, cuticle, or epidermis. The lower 
layer is called the true skin, or cutis. This is richly sup- 
plied with nerves and blood-vessels, and is so highly sen- 
sitive, that, were it not for the scarf-skin, we could not 
endure life. Most of us are familiar with tlie delicate pink 
skin, very sensitive and very painful, which is exposed 
when the lowest layer of the outer skin is removed by a 
blister, or rubbed off by some slight accident. The surface 126 
OUR BODIES. 
feels raw, and oozes a little clear fluid, or, perhaps, a little 
blood. This is the deeper portion of the scarf-skin, which 
is constantly growing, and developing millions of little 
round cells to take the place of the flat, horny, and lifeless 
scales of the outer portion, which are continually dropping 
off, or being removed by friction. 
When these flattened scales are pressed together, they 
Fig. 38. — Vertical Section of the Skin. 
become flatter and flatter; and thus the hard, horny skin 
is made, which is seen on the hands of those who use 
them in hard manual work. The “callous” in the hands 
of a blacksmith, carpenter, or washerwoman, is a familiar 
sight. Undue pressure or friction from poorly-fitting or 
tight-fitting boots and shoes causes the hard bunches on 
and between the toes, which are commonly known as corns. THE SKIN. 
127 
The deeper part of the scarf-skin is called the retc niucosum, 
meaning a “mucous network.” In it are tiny specks of 
coloring-matter, hid in little cells. It is this part of the 
skin that gives it its color, commonly called the com- 
plexion. In the fairer races, these specks are of a pinkish 
color : in the dark races, the pigment-cells are brown, or 
nearly black, and more closely crowded together. The 
heat of the sun acts to darken these color-specks, as is 
seen in the parts of the body exposed to direct sunlight. 
We see every day the sharp line drawn between parts 
of the arm or neck exposed to the sun’s rays, and other 
parts generally covered with clothing. Some, however, tan 
much more readily than others.( When the pigment mat- 
ter changes in spots, we call them freckles. There may 
be other defects, such as liver-spots, moth-spots, and other 
blemishes so often found on the skin. In slight burns, 
bruises, cuts, blisters, cold-sores, and many eruptions on 
the skin, .the epidermis only is affected. Such injuries 
and diseases, therefore, heal without a scar.* 
113. The True Skin. — The true skin, or cutis, is a firm, 
elastic tissue, resting on meshes of texture something like 
damp, raw cotton, which loosely fasten the skin to the 
parts beneath. It is the true skin which becomes filled 
with water in dropsy, and which is made into leather by 
the process of tanning. In this layer also are the sweat 
and oil glands, the hairs, nerves, blood-vessels, and absorb- 
* The epidermis prevents the skin from absorbing any poisons. Lead, 
mercury, and other injurious substances, will not enter the blood, and affect 
the bodily health, unless they are actually rubbed through the scarf-skin; 
but if there is a scratch or sore, so that the true skin is exposed, the 
poisons will be drawn into the blood with great rapidity. Workers in lead, 
looking-glass silverers, and phosphorus-match makers, ought, therefore, to 
take great care to cover the smallest scratch upon their hands. 128 
OUR BODIES. 
ents of the skin. The outer surface of the true skin 
rises into little ridges called “papillae,” into which the 
capillaries and nerves are distributed. These papillae 
are very numerous everywhere, but are the thickest where 
the sense of touch is most acute, as on the tip of the 
fingers and nose. They are arranged in rows, like hills 
of corn, and are plainly seen with a magnifying-glass on 
the palms of the hands. When the true skin is destroyed, 
a scar results. White scars, especially on the hands, due 
to deep cuts, are common enough. Scars from small-pox, 
deep burns, and other injuries to the true skin, are seen 
every day. The skin is rich in its blood-supply. The 
nerves are also very abundant. The prick of a pin, or 
the sting of the smallest insect, causes pain (Exper. 84). 
114. The Hair. — The hair and nails are simply portions 
of the outer layer of the skin altered in shape and struc- 
ture. Hair is a slender thread of scarf-skin, which grows 
from little sacs in the true skin called “hair-follicles.” 
Every hair has two parts, the root and the free end. The 
root is somewhat pear-shaped, and is sunk in its sac, or 
follicle, like a post into the ground. In the bottom of 
this sac is a little hair-papilla (quite distinct from the 
papillae of the skin), from which material for the life of 
the hair comes. As long as this papilla is not destroyed, 
the hair will grow. Pull out the hair “from the roots,” 
and it will grow again. Destroy this papilla, and the 
hair never grows again.'* 
* Hence it is useless, or worse than useless, to try to rid one’s self of un- 
sightly hairs or hair-moles on the face. Pull them out with tweezers, cut or 
shave them off, and they are sure to grow again, coarser, and more unsightly 
than before. All remedies advertised to remove superfluous hairs are worth- 
less or dangerous. The hair-papillae must be destroyed to stop the growth 
of hair, and this is no simple matter. THE SKIN. 
129 
One or more little glands open into each hair-sac, and 
pour out an oily matter for its nourishment. The outside 
of the hair is quite firm : the inside is softer, and carries the 
nourishing fluids. Hairs grow from cells pressed together 
lengthwise, so as to be drawn out into fibres, instead of 
being flattened into scales. Hence they grow only in 
length. On the outer surface the cells form a sort of 
bark, overlapping each other something like the shingles 
on a roof. The coloring-matter is contained in these cells. 
When it fails, the hair turns gray or white. The hair- 
follicle is well furnished with nerves, hence it hurts to 
have the hair pulled. The hairs, or rather the skin close 
to them, are provided with the tiniest muscles. They run 
from the bottom of each hair-follicle in a slanting direc- 
tion, and end in the outer part of the true skin. When 
they contract, they cause the hair to stand more or less 
erect, and the skin to “bunch up” a little. Thus, at the 
sight of a dog, the hairs on a cat’s back become erect 
and bristling. Any one who has been frightened suddenly, 
or has taken a chilly bath, knows what it is to have 
“goose-flesh.” * 
These muscles of the skin also act to squeeze oil out of 
the oil-glands. Hairs of some sort are found all over the 
surface of the body, except the palms of the hands and 
the soles of the feet.f They serve to protect the parts 
they cover from heat and cold. On the head, the hair 
* This idea of having one’s hair “stand on end” passed long ago into 
common speech and classic literature. Compare Job iv. 15. 
t The total number of« hairs on an average head is estimated at about 
120,000. The common diameter of an average hair is about of an inch. 
The strength of the hair is much greater than one would suppose. A single 
hair has held a weight of nearly 2\ ounces without breaking. 130 
OUR BODIES. 
helps to protect the skull from injuries, and the brain from 
extremes of heat and cold. On the body, they also help 
to drain off the sweat. 
115. The Nails. —The nails are only portions of the 
scarf-skin in a hardened, form. They grow from roots 
which are lodged in a groove of the skin, something as 
a watch-crystal is fitted into its case. The part which is 
beneath the skin towards the hand is called the root, and 
the rest the body. The nail rests upon a bed, called the 
matrix, to which it is firmly fastened. Nails grow from 
the root; and, as long as this is not injured, they are not 
lost or disfigured by slivers, sores, blows, and bruises. 
Disease or injury of the root generally results in a badly- 
shaped nail. The nails serve by their horny texture to 
protect the outer portions of the ends of the fingers and 
toes from injury, and to give a support for the fleshy ends. 
Our finger-nails grow out about three times a year. 
They should be trimmed with the scissors once a week, 
leaving them long enough to protect the ends of the fin- 
gers. Nails should never be trimmed to the cpiick. They 
should not be cleaned with any thing harder than a brush, 
or bit of soft wood. They should not be scraped with a 
penknife, or any thing metallic ; as it destroys the delicacy 
of their structure, and will give them an unnatural thick- 
ness. “Hang-nails” are caused by the skin sticking to 
the nail, which, growing outward, drags the skin along 
with it, stretching it until one end gives way. To prevent 
this, the skin should be loosened from the nail once a 
week, not with a knife or scissors, but with something 
blunt, such as the small end of a tooth-brush, or an ivory 
paper-cutter. (Exper. 85). 
116. The Oil-glands. — The oil-glands are little round THE SKIN. 
131 
sacs, clustered together like a bunch of grapes, with a tube 
which opens into the hair-follicles. Generally there are 
two to each hair; but, in some places, there are as many as 
four to eight around a hair, making a kind of collar about 
it. These glands furnish a natural dressing for the hair, 
and keep it moist and glossy. They also keep the surface 
of the skin soft and flexible, and prevent it from becom- 
ing dry and hard. In some places, these glands, as upon 
the nose, chin, and forehead, are large, and the hairs very 
small: hence it often happens that they open directly 
upon the skin. In these the oil is likely to collect, and get 
hard. Bits of dust get into these glands, acting like plugs, 
and show themselves as small black specks, incorrectly 
called “flesh-worms,” because of the resemblance which 
these little masses have to a worm. This oily secretion, 
which might well be called nature’s hair-oil, is perfectly 
fluid in a healthy skin, and at the temperature of the 
body. 
117. The Sweat-glands. — The sweat-glands consist of 
very fine tubes, about one-tenth of an inch long, coiled up 
into knots, from each of which a canal, called a sweat- 
duct, opens on the surface of the skin. The openings 
of these sweat-glands are arranged somewhat regularly, as 
may be seen by a common magnifying-glass, especially on 
the palms of the hands, between the ridges of the skin. 
On the sole of the foot and the palm of the hand, they are 
very numerous, there being some three thousand of them 
to the square inch; while, on the cheeks, there are only five 
hundred and fifty in the same space, and twelve hundred 
to the square inch on the forehead. There are about three 
millions of them, it is said, in the whole body ; and, if 
they were laid end to end, they would stretch to a distance 132 
OUR BODIES. 
of three to four miles. These glands secrete the sweat, 
which is a colorless fluid, with a peculiar odor. It is a 
part of the waste matter of the tissues, which has been 
filtered from the blood, and is got rid of through these 
busy little glands in the skin. They are always at work 
pouring out sweat, though it may not be evident to the 
eye or touch. In hot weather, or after violent exercise, 
it is much increased, and collects in big drops, which run 
away in streams. The average daily quantity of sweat 
is not far from two pints. It varies very much accord- 
ing to what# we are doing, the condition of health, how 
we are clothed, and the temperature of the surrounding 
atmosphere. The object of this sweating through the 
skin is to regulate the temperature of the body by evapo- 
ration from the surface. We fan ourselves on a hot day 
to hasten this evaporation of the moisture on the skin. 
In hot weather, after taking hot drink, or a hot-air bath, 
the skin does its best to reduce the temperature, and thus 
works all the harder in pouring out the sweat more pro- 
fusely. When one is sweaty, it is highly imprudent to sit 
in a cool draught; for this evaporation may be suddenly 
checked, and we are apt to take cold. It is now easy to 
see, that if this vast secreting-surface is hindered in its 
action * by chilling it in a draught, by being too thinly 
clad, or by sudden changes in the weather, we may readily 
“catch cold,” and cause a “congestion,” as it is called, 
* If a rabbit be varnished all over, so that the action of its skin is com- 
pletely stopped, it will die within two hours, with every symptom of being 
poisoned. A similar experiment was once accidentally made upon a human 
being. When Pope Leo the Tenth ascended the papal throne, a child was 
prepared to represent in his procession the Golden Age, which was supposed 
to be dawning, by being varnished all over, and covered with gold-leaf; and 
the poor child died in six hours. THE SKIN. 
133 
of certain internal organs, like the lungs, kidneys, or 
intestines (Exper. 86). 
118. Why we should take Care of the Skin. — There 
are nearly three millions of sweat-glands in the skin, act- 
ing like drainage-tubes, nearly three miles long, together 
with the oil-glands, pouring out two pounds daily of sweat, 
oil, and other used-up matters, through the hard-worked 
skin. The sweat evaporates, and leaves the solid and oily 
matters to plug the mouths of these sewer-pipes. The 
dead scales of the scarf-skin are continually dropping off. 
They become sticky with the oil, and, getting entangled 
in the meshes of the clothing, become glued in a kind of 
thin crust to the surface of the body. This, if not regu- 
larly washed off, attracts the floating dirt and dust. Thus, 
the glands of the skin get choked up, and are not able to 
do their work properly. Other organs, such as the lungs 
and kidneys, have to do their own work, and that of the 
skin besides. The balance of health is disturbed, because 
the blood is not properly purified ; and disorders, especially 
of the skin, are almost sure to result. Hence we see both 
the importance and the real need of keeping our bodies 
clean and neat. The fireman is ever busy rubbing and 
polishing his engine, to rid it of the dust, oil, and dirt, 
and to make it bright, clean, and neat. He is thus able to 
have all the parts of the machinery running smoothly, and 
without friction. Surely we should take as good care of our 
person, especially of its surface, which is always sifting- 
out impurities, and getting clogged with dust and dirt. 
Finally, a filthy skin often becomes a breeding-place for 
the spread of those diseases and ailments which are 
“ catching,” such as scarlet-fever and measles, to say 
nothing of certain contagious disorders of the skin, by no 
means dangerous, but decidedly unpleasant. 134 
OUR BODIES. 
119. Baths, how and when to take them. — The first 
object in using soap and water on the skin is to keep 
it clean ; the second, to give vigor and strength to the 
whole body. It takes very little time, expense, or bother 
to take a daily bath of some sort. A hand-basin, a 
sponge, a strip of cotton-flannel, a piece of castile soap, 
a gallon of water, and a towel, are all that are required. 
Even rubbing the body every day, first with a damp towel, 
and afterwards very briskly with a dry one, will, in most 
cases, keep the skin clean enough during the week, and 
give a healthy re-action, provided a bath with warm water 
and soap is taken at the end of the week. Whether the 
daily bath should be taken in warm or cold water depends 
upon circumstances. Most persons, especially the young 
and vigorous, soon get used to cool, and even cold, water 
baths. The point is, to get a brisk and rapid re-action 
before the “shivers ” come on. If we shiver after a bath, 
instead of getting a warm, comfortable glow, warmer water 
should be used. The first effect of any cold bath is to 
shrivel up all the vessels of the skin, and make the surface 
pallid. Brisk rubbing should soon bring on a re-action, 
as it is called, in which the skin becomes red, and full of 
blood. A feeling of genial warmth is felt all over the 
person. Always stop bathing if the shivering comes 
on, and use the towel vigorously until re-action sets in. 
Young children and old people, unless strong, vigorous, and 
well used to it, cannot take a cold bath without some risk. 
Like all other things, it may be weakening to carry bath- 
ing to excess. Very much depends upon one’s occupation 
and the condition of the skin. In some work, the grim, 
dust, and sweat must be washed off at least once a day, 
to feel at all comfortable, to say nothing of the health. THE SKIN. 
135 
Coarse and rough towels should always be used if the 
skin will bear it. Some skins are very active common 
sewers, which are ever sending out a large amount of 
waste matters. In such cases, a daily bath, especially in 
hot weather, is almost a necessity. Hot baths, with hot 
drinks, causing free sweating, helped on by wrapping the 
person snug in bed, with a jug of hot water or a hot flat- 
iron at the side or feet, will often save children and others 
from illness, if promptly and vigorously done after expos- 
ure to cold or wet. Swimming in running fresh water or 
in the sea has a wholesome effect on the skin, and is one 
of the healthiest of all exercises. Young people of both 
sexes should be taught to practise it whenever it is con- 
venient. Never go in swimming when the body is over- 
heated or very tired. Better sit down quietly, and cool 
off for half an hour. Many are drowned every year from 
ignorance or carelessness in this one matter alone. The 
risk, of course, is from sudden cramps and colicky pains, 
which cause even a strong swimmer to sink like a lump 
of lead. For the same reason, it is not safe to take a swim 
just after a full meal. 
It is a good time for vigorous persons to take a cold 
bath just after getting out of bed in the morning. A bath 
at bedtime is refreshing, and favors sound sleep. There 
is little risk of taking cold if we go to bed at once. 
Young and feeble children should bathe two or three 
hours after breakfast. 
It adds to our health and comfort to keep the hair clean. 
The oil -glands get clogged ; and dust and dirt rapidly make 
a coating on the scalp, and get entangled in the hair. 
Hence the head should be washed, combed, and brushed, 
often and well. An occasional shampoo at home, with a 136 
OUR BODIES. 
wash made of the white of an egg and soapsuds, is health- 
ful. Even a little borax dissolved in plain water, with 
vigorous rubbing, will do much to keep the scalp neat and 
clean. 
120. Why we need Clothing.— Clothes serve to keep 
up an even temperature about the surface of the body.' In 
winter, they keep in the bodily heat, and protect us from 
cold. In summer, they shield us from the direct rays of the 
sun, and from excessive heat. The temperature of our 
bodies varies only a few degrees at the most from F. 
In our climate, the outside air has a yearly range from 100° 
or more in midsummer to 20° or more below zero in winter. 
We may even have a daily change of 20° to 40° F. Our 
body is clearly much warmer than the surrounding atmos- 
phere, and so it is continually parting with heat to the 
air. 
These frequent changes are a severe tax on the body. 
Without the protection of clothing, we could not endure 
the strain on the system. In short, clothing is our chief 
weapon of defence against the frequent changes of weather 
in our fitful climate.* 
121. Hints on the Use of Clothing.—Clothes should 
be changed according to the climate, or time of year. It 
is not prudent to leave off winter clothing too early in 
the spring, for our seasons are most uncertain. Woollen 
should be worn next to the skin, whether in summer or 
winter. A most imprudent but common error of our daily 
living is to take off our winter flannels some day in early 
* We often fail to recognize the danger of exposure to cold. One week’s 
continuous cold in London, it is said, adds over two thousand deaths to the 
usual average; and they mostly occur among the poor, under-fed, and badly 
clothed class of the population. THE SKIN. 
137 
summer because it happens to be warm. With our sud- 
den changes of temperature, a person may run great risk 
of taking severe colds, pneumonia, and even “quick con- 
sumption.” * 
To keep our persons neat and clean, we must change 
our clothes often. This not only applies to garments 
used for daily wear, but to bed-clothes and night-clothes. 
No one should sleep in the clothes he wears during the 
day. Under-garments should be frequently and regularly 
changed. All bed-clothes should be exposed freely to the 
light and air. Young children are less able to resist cold 
and sudden changes than grown-up people, hence great 
care must be taken in their clothing.f 
The legs and chests of children should not be unduly 
exposed to the bitter blasts of winter, nor the cold east 
winds of spring. Hundreds of children die every year 
from lung-diseases, due to ignorance or neglect in this 
matter. Never wear wet or damp clothes one moment 
longer than possible. If you have on wet clothes, take 
the shortest way home, rub down thoroughly, and put on 
at once dry, warm clothes. Do not let your damp skirts, 
wet stockings or shoes, dry on you, but always change 
them at once if possible. Neglect of this precaution is a 
fruitful cause of rheumatism and chest-ailments, especially 
among delicate people and young women. Do not wear 
* “ We should put off our winter clothing on a midsummer’s day, and put 
it on again the day after. Only fools and beggars suffer from the cold; the 
latter not being able to get sufficient clothes, the others not having the sense 
to wear them.” — Boerhaave. 
t The celebrated surgeon, John Hunter, gave three simple rules for the 
rearing of children ; and they are just as applicable to adults. They are, 
“plenty of sleep,” “plenty of milk,” and “plenty of flannel.” 138 
OUR BODIES. 
the clothing too tight, and thus allow it to interfere with 
free movements and easy and graceful carriage, to say 
nothing of health. Garters and elastics worn below the 
knee are apt to hinder the circulation, and cause cold feet, 
and sometimes enlarged veins. Dresses and skirts should 
never drag their full weight from the hips, but should be 
supported from the shoulders. Health and comfort should 
not be sacrificed by any strange devices to dress the per- 
son in a slavish submission to any fashion. Teachers and 
parents should take the utmost care in the matter of chil- 
dren’s clothing. See to it that they have on the proper 
outside garments on going out, and that they are taken off 
on coming indoors. Children, and older people too, should 
never run outdoors without proper covering for the head. 
Never allow pupils to sit in the schoolroom with outside 
garments on, such as waterproofs, gossamers, cloaks, rub- 
bers, rubber boots, and leggings. 
Practical Points.—Those who value their health, and beauty of com- 
plexion, should let all “perfectly harmless” cosmetics and toilet-powders 
severely alone. Pure rice-powder, bought from some trustworthy druggist, 
is good enough to remove the greasy feeling from the skin, if any thing must 
be used. 
Some people are troubled with profuse sweating, which is quite offen- 
sive, especially under the arms, or on the feet. Bathe the parts, and change 
the clothing often, using occasionally a weak carbolic wash. A tea of white- 
oak bark, applied freely, is a simple remedy. 
Ale, beer, wine, and cider are very frequent causes of skin-diseases. They 
must never be used by one who expects to get well from any such ailments. 
The skin may absorb certain poisons very readily. Lead is often thus 
absorbed, causing in time “ lead-colic ” and the “ wrist-drop.” Cheap clothing, 
as colored stockings, are often dyed with preparations of lead. Such articles 
should be thoroughly washed before they are worn. Many hair-dyes contain 
lead, and often cause symptoms of lead-poisoning. 
Collateral Reading. Bulkley’s The Skin in Health and Disease, Packard’s 
Sea-air and Sea-bathing, “ American Health Primers; ” The Skin and its Trou- 
bles, Baths and Bathing, “ Health Primers.” THE SKIN. 
139 
TEST QUESTIONS FOR REVIEW. 
1. What is the skin, and what is its use? 
2. Describe its structure in a general way. 
3. Give in detail a description of the cuticle, or scarf-skin. 
4. Where is the coloring-matter of the skin situated ? 
5. Describe the cutis, or true skin. 
6. Describe the hair; its structure; muscles; number of hairs 
7. Describe the nails. 
8. What care would you take of them ? 
9. What are the oil-glands ? 
10. Describe the sweat-glands. 
11. What is the use of the sweat ? 
12. Give some reasons why we should take care of the skin. 
13. Baths. Why, when, and how to take them. 
14. Why do we need clothing ? 
15. Give some hints about the use of clothing. 140 
OUK BODIES. 
CHAPTER IX. 
THE NERVOUS SYSTEM. 
122. How All Parts of the Body work together in 
Harmony. — We have studied the human body as a kind 
of living machine. We have examined its various parts, 
and found them adapted to some special work essential 
to the well-being of the whole. Each organ not only looks 
after itself, but it is ever ready to come to the help of other 
parts of the body. Everywhere we find organs working 
together for each other’s good. Strike suddenly at the 
eye, and the lids fall to protect it. Tickle the foot, and 
the muscles of the thigh and leg contract, and pull it 
away. When the skin is inactive, the kidneys come to 
its help. Fifty skilled mechanics might do their best at 
building a vessel or a house ; but if each man worked as he 
pleased, and took no heed of the rest, the result of their 
work would be of little account. The master-builder must 
be at his post, skilful to direct, and quick to act. So it is 
with our bodies. The wonderful agency which directs and 
governs every organ of the body is the nervous system. 
123. The Nervous System. — The nervous system is to 
the organs of the body what steam is to the engine. Shut 
off the steam, and rods, wheels, and bands, which a mo- 
ment before were whirling round, at once become still and 
useless. So with the body : any injury to the nervous sys- THE NERVOUS SYSTEM. 
141 
tem may paralyze some or all of the various organs, and 
at last produce death. 
The nervous system may be compared to nothing so 
aptly as to a complete telegraphic system. The brain 
itself is the main office; and the thousands of nerve-fibres, 
CEREBRUM-j 
MEBULLA 
OBLONGATAJ 
CEREBELLUM"] 
SPINAL CORD- 
-SPINAL COLUMN 
our trios of 
SPINAL NERVES 
Fig. 39.—Diagram of Brain and Spinal Cord. 
branching off to all parts of the body, are the telegraph- 
wires. Telegraphic despatches are constantly being sent 
to the brain, to inform it of what is going on in various 
parts of the body. The brain, on receiving the news, at OUR BODIES. 
142 
once sends back its commands as to what must be done in 
each case. 
Thus, if we accidentally pick up a hot coal, we drop it 
instantly. A message is sent from the nerves of touch in 
the fingers to the brain ; 
and, when the brain learns 
that the fingers are being 
burned, it hurries off its 
orders to the muscles of 
the fingers to drop the 
burning coal. We might 
multiply these examples 
to almost any extent. 
Every act of the will we 
make is carried out under 
the direction of the ner- 
vous system, and by the 
same process. 
The nervous system 
consists of two distinct 
parts : — 
1. The brain, spinal cord, 
and cerebrospinal nerves, 
forming an unbroken con- 
nection between the brain 
and all parts of the body. 
2. The sympathetic sys- 
tem, which is connected 
mainly with the organs of digestion, circulation, and res- 
piration. 
124. Nerve-tissue. — Nerve-tissue is the soft, marrow- 
like substance which forms the principal bulk of the brain, 
Fig. 40. — Diagrammatic View of the Brain, 
Spinal Marrow, and Nerves (from behind). THE NERVOUS S VS TEAL 
143 
the spinal cord, and the nerves. In the brain the inner 
part is white, and the outer layer is a gray or grayish-pink 
substance. In the spinal cord the inner part is gray, and 
the outer, white. The gray is richer in blood-vessels than 
the white. 
All muscular action, we have learned, results in the oxi- 
dation, or burning, of the muscles themselves. In the 
same way the work of the brain causes the oxidation, or 
burning up, of its nerve-tissue ; so that every thought, 
every sensation, every effort of the will which goes from 
the brain, destroys a part of its substance. 
The nerves are really so many portions of the brain and 
spinal cord, extending into every minute part of the body. 
A nerve is a slender silvery-white cord when seen by the 
naked eye. Under the microscope, this white part is seen 
to consist of bundles of delicate little fibres. 
125. The Brain. — The brain is the organ of the mind. 
In other words, it is the seat of the consciousness, the 
intellect, the memory, the will, the affections, and the emo- 
tions. This important organ fills the entire cavity of the 
skull, and consists of a number of separate masses of nerve- 
matter abundantly supplied with blood-vessels. Each sep- 
arate mass is the main workshop for some special depart- 
ment of the work of the nervous system, and has little or 
no connection with the other parts. The average weight 
of the brain is about fifty ounces, or about three pounds.* 
* Daniel Webster’s brain weighed fifty-three and a half ounces, and 
Ruloff’s — a notorious murdeier, but in some respects a very learned man — 
fifty-nine ounces. The brain of Cuvier, the celebrated naturalist, weighed 
sixty-four and a third ounces; and that of Dupuytren, a famous French sur- 
geon, sixty-two and a half ounces. The hats of ten gentlemen were tried 
upon the skull of Robert Burns, and the only one of the ten that could cover it 
was the hat of Thomas Carlyle. An idiot’s brain rarely exceeds thirty ounces. 144 
OUR BODIES. 
A few cases have been noted in men of great mental 
capacity, in which the brain weighed sixty-four ounces. 
Such instances are, however, far from common. As a 
rule, a large brain is the sign of a vigorous mind and 
superior faculties ; and a healthy brain, of a sound, healthy 
mind. 
The three principal masses Which compose the brain 
are, (i) the cerebrum, or brain proper; (2) the cerebellum, or 
lesser brain; (3) the medulla oblongata. 
FRONTAL PART OF BRAIN 
Fig. 41.—Upper Surface of Brain, Membranes removed, showing Convolutions, 
126. The Cerebrum, or Brain Proper. — The cerebrum 
fills the whole of the upper part of the skull, and is nearly 
seven-eighths of the entire mass. It consists of two parts, 
or halves, almost entirely separated from each other by a 
deep cleft, or fissure, from front to back. Each of these THE NERVOUS SYSTEM. 
145 
halves, or hemispheres as they are called, consists of three 
portions or lobes, so that the cerebrum is made up of six 
distinct parts. The cerebrum has a peculiar folded-up 
appearance ; its various folds, or convolutions as they are 
called, being separated by deep clefts, sometimes nearly 
an inch deep (Fig. 41). In this simple way, the surface 
of the brain is increased many fold. The interior part of 
the brain is made up of the white nerve-substance just 
spoken of. The gray matter is the outer layer, about one- 
eighth of an inch in thickness, and is spread over the 
white substance like a handkerchief crumpled up.* The 
active powers of the brain are supposed to reside in this 
outer layer; and these powers are great or small, according 
to the number and the extent of the folds, or convolutions. 
In the lower animals, the brain has no folds; but, as we 
pass to animals of a higher grade, the folds begin to appear. 
127. The Cerebellum, or Lesser Brain.—The cere- 
bellum, or little brain, lies beneath the back part of the brain 
proper, from which it is separated by a fold of the dura 
mater. It is made up of two halves, each formed of a 
number of layers of gray and white nerve-matter, curiously 
arranged, resembling somewhat the branches of a tiny tree. 
The functions of the cerebellum are not yet certainly 
known. It is supposed to exercise an influence over the 
muscles of the body, in regulating their movements. 
128. The Medulla Oblongata. — The medulla oblongata 
* The brain is enclosed within three distinct layers, called its membranes, 
— the dura mater (“hard mother”), the arachnoid (like a spider’s web), 
and the pia mater (“delicate mother”). The dura mater is the tough 
membrane which lines the inner surface of the skull, and forms a loose outer 
covering for the brain. The middle layer, called the arachnoid, secretes a 
fluid which keeps the inner surface moist. The pia mater is a’very delicate 
membrane which dips down between and lines the folds of the cerebrum. 146 
OUR BODIES. 
is the thick upper part of the spinal cord which is held 
within the cavity of the skull. It is just under the little 
brain, and makes the connecting link between the brain 
and the spinal cord. It is a small affair, only an inch and 
a half long; but it is a highly important part of the brain, 
since from it arise the nerves which regulate breathing, 
swallowing, the heart’s action, and so on. 
The seat of sensation is believed to be lodged in the 
upper part of the medulla oblongata. It has also control 
over the action of the lungs and the heart. If this part 
of the brain be broken or cut, respiration and circulation 
will at once cease, causing instant death.* 
129. The Cranial Nerves. — From the brain proceed 
twelve pairs of nerves, called crania! nerves. These nerves 
pass out of the skull through little holes in its base, and 
supply the face, certain internal organs, and the organs of 
smell, taste, hearing, and sight. These cranial nerves are 
of three kinds, sensory, motor, and mixed; i.e., combining 
both. The tenth pair is called the pncumogastric vagus, 
meaning the “wandering nerve.” This is perhaps the 
most important nerve in the body. It supplies the larynx, 
the lungs, the heart, the stomach, and the liver. It is 
partly motor and partly sensory. 
130. The Spinal Cord. — The spina! cord, or marrow, is 
a cylinder of soft nerve-tissue, extending from the base 
of the skull to the region of the loins, where it tapers off 
* Cattle are killed in great slaughtering-establishments by workmen 
skilled in striking the animals in the back of the neck, and piercing the 
medulla with a sharp instrument made for the purpose. Spanish criminals 
are executed by the “garotte,” which is an iron collar, put round the neck, 
with a sharp-pointed pin, made to pierce the medulla with a quick turn of a 
lever, thus causing instant death. The Spanish bull-fighter seeks to kill his 
enemy by pricking the “vital knot ” with his sharp sword (Exper. 88). THE NERVOUS SYSTEM. 
147 
into little threads. It is a continuation of the medulla 
oblongata, and its average length is about eighteen inches. 
Like the brain, the spinal cord consists of the two kinds 
of nerve-matter, — white and gray : but their position is 
reversed ; the gray being in the inside, and the white out- 
side. 
OLFACTORY BULSs 
Fig. 42. — Base of Brain. 
The spinal corcl receives impressions from various parts 
of the body by means of its sensory nerves, and carries 
them to the brain, where they excite sensation, or con- 
sciousness. 
Again, it sends out, by means of its motor nerves, the 
commands of the brain to the voluntary muscles. 
131. Reflex Action of the Cord and Brain. — The 148 
OUR BODIES. 
spinal cord is not merely a bundle of nerve-fibres for car- 
rying messages to and from the brain. It has a certain 
power of its own. It acts as a kind of independent centre, 
receiving messages, or sensations, from certain parts of 
the body by means of its sensory nerves, and on its own 
authority sending back orders to the muscles by its motor 
nerves, without waiting to consult the brain. This is 
what is known as reflex action. 
If one is asleep, and the feet are gently tickled, the 
Fig. 43.—Vertical Section of Brain. 
SPINAL CORO 
legs will be moved out of the way without the sleeper 
necessarily being awakened. When the spine is broken 
by an injury, causing pressure upon the cord, then all sen- 
sation and motion are lost in the paralyzed limbs. But if 
these paralyzed limbs are irritated, as by pricking the 
soles of the feet, then the legs kick out vigorously. The 
injured person does not feel the pricking, and can exercise 
no control over the kicking legs. There is here no con- THE NERVOUS SYSTEM. 
149 
scious action whatever. This unconscious action is the 
result of reflex action of the spinal cord. It is called 
reflex because the impression does not go to the brain, 
but is “reflected,” meaning “to turn back again,” to the 
seat of injury, from the sensory nerves through the motor 
nerves. 
132. Importance of Reflex Action. — We rarely stop 
to think how important reflex action is to our health, 
comfort, and safety. Because we are able to do hundreds 
of things every day without any effort of the will, we are 
apt to forget its importance. In fact, the greater part of 
nerve-power expended in the body goes to produce these 
Fig. 44.—Diagrams showing the mechanism of a simple reflex action: 1, surface, say of 
mucous membrane; 2, muscle; A, sensory nerve; B, reflex centre; C, motor nerve. 
numberless reflex actions. We are not so independent as 
one would at first think. Ten thousand acts take place, 
which tend to govern and preserve our health. We 
have as little control over them as we do over the stars 
above us. We have already been told of a few reflex acts. 
Let us call to mind a few more familiar illustrations. If 
our feet slip on the ice, without the effort of the will, the 
body tends to recover itself. The mind does not act, at 
least in the ordinary way, to pull the fingers away when 
they touch a hot stove. We try to brush the flies away 
when we are asleep. By an effort of the will, we can stop 
our breath for a moment or two : but soon the call for air 150 
OUR BODIES. 
is imperative ; and the order must be obeyed, whether we 
will or no. The great work of digestion is going on day 
after day, and we have not the least command over its 
complicated movements. 
By this wonderful provision of Nature, the thinking- 
centres are relieved of a vast amount of work. If we 
were forced to use our will-power at every step in the 
process of digestion, the brain would be put to a severe 
strain. We could not eat, and then quietly go about our 
business. If we had to plan and will every heart-beat, 
we should soon be ready to give up the struggle for life. 
If we had to exert our will every time we breathed in or 
out, we would soon get tired of it, and long to die. We 
could never sleep ; for the brain would have to be on the 
alert to decide if it were time for the next heart-beat, 
the next inspiration, and the proper time for each diges- 
tive fluid to flow (Exper. 89). 
133. The Spinal Nerves. — From the spinal cord pro- 
ceeds thirty-one pairs of spinal nerves to the trunk and 
limbs. They pass out on each side of the spinal canal 
through small holes in the sides of the backbone. Each 
of these spinal nerves has two roots, — one going from 
the front portion of the cord, and the other from the 
hinder portion. These two roots unite, and run side by 
side, forming one silvery thread as they pass out from the 
backbone. The root which goes from the front, or an- 
terior, part of the spinal cord, is the motor nerve, and con- 
trols the motions of the muscles of the body. That which 
comes from the back, or posterior, part of the cord, is the 
sensory nerve, and carries sensations from the various 
parts of the body to the spinal cord. As each nerve- 
trunk leaves the backbone, it subdivides, and sends off THE NERVOUS SYSTEM. 
151 
branches into all parts of the body. If any one of 
these nerves is cut or injured as it leaves the backbone, 
the power of feeling and movement ceases in all those 
parts to which it is distributed ; that is, those parts of the 
body are paralyzed.* The case is practically the same as 
cutting a telegraph-wire, and thus stopping the passage of 
the electric current. To a certain extent this is the case 
when our leg or arm “goes to sleep.” The fact is, some 
of the nerves have been pressed upon, and their action is 
Fig. 45. — Front View of Portion of Spinal Cord, with Roots of Nerves; one of the 
Anterior Roots divided to show the Posterior. 
stopped for the time being. Remove the pressure, and 
the nerves regain their power f (Exper. 87). 
134. The Sympathetic System of Nerves. — Besides 
the system of nerves just described, there is another set 
* A very important and interesting point to notice, is that, as the motor 
nerve-fibres leave the brain, they cross over from one side of the spinal cord 
to the other. The sensory nerve-fibres cross in the same way soon after 
entering it. Thus, the right half of the brain governs the left half of the 
body, and the left half of the brain controls the right side of the body. A 
blow on either side of the brain may therefore produce paralysis of the op- 
posite side of the body. Thus, if we see a person with left side paralyzed, 
we know that the seat of injury is on the right side of the brain. 
t Imagine a telegraph-cable of delicate India-rubber tubes filled with 
mercury: a squeeze would interrupt the continuity of the cable without 
destroying its physical continuity. Remove the pressure, and the current 
would pass along the cable as usual. 152 
OUR BODIES. 
of nerves in the body, known as the sympathetic nervous 
system.* It consists of a double chain of nerve-knots, or 
ganglia, connected by nervous cords running down in front 
and on each side of the backbone. This chain of nerves 
is not shut up within the bony tube formed by the skull 
and spine. The knots of nerves are connected with each 
other, and with the sensory roots of the spinal nerves, by 
a network of gray nerve-tissue. From these knots, nerves 
go to all the internal viscera, forming a complete system 
by themselves, and acting almost independently of the 
cerebro-spinal system. A close network of the sympa- 
thetic nerves is spread round the muscles of the heart, the 
lungs, the stomach, and the intestines, as well as round 
the walls of the minute arteries and capillaries. 
Compared with the cerebro-spinal set of nerves, the 
sympathetic nerves are very slow to act. A blush steals 
slowly up to the roots of the hair. If we go from the 
dark into a strong light, we are blinded ; the pupil is too 
large to endure it. An impression is made on the sym- 
pathetic nerves, which cause the pupil to contract slowly 
while we are shading our eyes. 
135. Sleep. — Sleep is necessary to life and health. In 
our waking-hours, rest is obtained only at short intervals. 
The muscles and nerves, the brain in particular, are in full 
activity when we are awake. Repair goes on every moment, 
whether we are awake or asleep; but during the waking- 
hours the waste of the tissues is far ahead of the repair, 
while during sleep the repair vastly exceeds the waste. 
* The name “sympathetic” is given to this part of the nervous system, 
because it is believed, that, through its agency, distant organs have sympathy 
with one another’s afflictions. Thus, for example, severe pain in any part 
of the body will cause some sensitive persons to be sick at the stomach. THE NERVOUS SYSTEM. 
153 
Hence the good mother Nature, at regular intervals, 
causes all parts of the bodily machinery to be run at their 
lowest point. In other words, we are put to sleep.* 
To be sure, the heart beats, the lungs take in air, and 
the stomach digests its food; but these great organic pro- 
cesses are carried on at their lowest point. The vital 
organs rest because they are worked at the lowest rate 
that will keep us alive. The eye, the ear, the brain, and 
the nerves, are at rest by darkness, silence, and uncon- 
sciousness. The tired muscle regains its vigor, and the 
exhausted brain is refreshed. Sleep is more or less sound 
according to circumstances. Fatigue, if not too great, 
aids it ; while idleness lessens it. Some kinds of food, as 
tea and coffee, may prevent it. Anxious thought and 
pain, and even anticipated pleasure, may prevent it. Just 
as sleep is sound, the body and mind are refreshed. The 
best time for sleep is at night. The soundest and best 
sleep is obtained during its silence and darkness. People 
who are forced to work nights, and to sleep during the 
day, have a strained and wearied look, which is easily 
recognized by the trained eye. 
The amount of sleep depends upon the occupation and 
temperament of each individual. Some require little 
sleep, while others need a great deal. Eight hours of 
sound sleep for a grown man or woman, and more for 
children and old people, is about the average amount 
required. Children naturally need more sleep, because 
their bodies need more rest during the period of growth. 
* The great classic writers of all time have symbolized sleep under all 
kinds of fanciful expressions. Shakspeare alludes to sleep as “the golden 
dew,” “our foster-nurse of nature,” “nature’s soft nurse,” “death’s coun- 
terfeit,” “the death of each day’s life,” “great nature’s second course,” 
“ chief nourisher in life’s feast.” 154 
OUR BODIES. 
Hence the infant sleeps most of the time, if well, and 
properly cared for. Children should always be put to 
bed early, and allowed to sleep in the morning until they 
awake of themselves. During hot weather, the active 
child should be undressed, bathed, and put to bed in the 
middle of the day for a good nap. We should not eat just 
before going to bed. There should be an interval of three 
hours between supper and sleep. Do not go to bed with 
the brain excited or too active. Read some pleasant book, 
laugh, talk, sing, take a brisk walk, or otherwise take a 
little recreation, for half an hour or so before going to 
bed. 
136. The Health of the Nervous System. — It is 
scarcely necessary to discuss in detail the hygiene of the 
nervous system, as we have done with other parts of 
the body. In fact, the health of every tissue and every 
organ is so dependent upon, and so woven into, the wel- 
fare of the nervous system, that it is impossible to sepa- 
rate them. A blow on the head often causes vomiting. 
If a tiny blood-vessel in the brain is broken, and forms a 
little clot as large as a pea : by its pressure on the deli- 
cate brain-tissue, a paralysis of one side may be produced. 
An overloaded stomach may make the brain dull and 
stupid for some time. Ill-digestion may change the dispo- 
sition, and make one cross, morose, and ugly. The loss 
of sleep may produce exquisite suffering. In early English 
history, people who were condemned to death by being 
prevented from sleeping, always died raving maniacs.* 
* Depriving a criminal of sleep is a frequent mode of execution in China: 
it is fearfully painful, and death occurs in eighteen to twenty days. 
After eight days, the sufferings of a criminal subjected to this process 
become so intense that he begs to be burned, strangled, shot, or put to 
death in any way that the humanity or ferocity of his jailers may suggest. THE NERVOUS SYSTEM. 
155 
Those who are starved to death become insane. The 
brain is not nourished, and they cannot sleep. A blow 
on the head, and certain diseases, may produce a profound 
and mysterious effect upon the nervous system. 
On the other hand, severe accidents to the brain may 
not produce serious results.* 
Like any other organ, the brain may be strengthened 
and increased in its power by use and education. Impres- 
sions made upon the mind in early life are both more 
readily received and more completely retained than those 
which are made when the growth of the brain is far ad- 
vanced. For this reason, education should be begun early 
in life. It is an object for which most parents are willing 
to work hard, and exercise much self-denial, to accomplish 
(Expers. 90, 91, 92, 93). 
137. Abuse of the Nervous System. — Just as the 
stomach may be overworked, and fail after a time to digest 
food properly ; and as muscles are exhausted by over-exer- 
tion, — so may the nervous system, especially the brain, 
be overtaxed. Mental work is rarely hurtful to a healthy 
person who takes good care of himself. It is not so much 
the.severe mental toil, as it is worry, that makes the 
mental wreck. It is not study, but fretting, that causes 
the student to break down in his studies. It is the fearful 
wear and tear of the nervous system in the fierce struggle 
for wealth and position, that makes an old man out of a 
young one before he is forty. Let a child have plenty of 
* A well-known case in point is of a man who had an iron drill, over 
three feet long, and more than an inch in diameter, blown entirely through 
his head while blasting rocks. The man lived many years afterwards, and 
his skull and the iron bar may be seen in the museum of the Harvard Medi- 
cal College. 156 
OUR BODIES. 
nutritious food properly given, plenty of sound sleep, 
enough of suitable clothing, and a calm and wise over- 
sight at home, and he will rarely be injured by too much 
study. It is fretting about passing examinations, worry- 
ing about promotions, and other baneful influences which 
have become attached to our educational system like bar- 
nacles to a stately ship, that make the delicate, sensitive 
child cross, peevish, and sickly, and lay the foundation for 
years of ill-health. 
Every part of the nervous system is busily at work 
doing its allotted duty. The vast sympathetic system, 
which lies at the very foundation of our nutrition, is 
severely taxed to do its work properly. Now, let a person 
fret and worry day after day over real or fancied troubles, 
abuse his digestive organs by too much or too little food, 
go without proper sleep, turn night into day, try to prop 
up his flagging energies with more or less of alcoholic 
liquors, and the strain on the nervous system will make 
a physical and mental wreck. Like a spendthrift, who 
lavishly spends his principal, and persists in calling it his 
income ; so is a man, who is indulging in all these forms 
of dissipation, really exhausting a limited amount of ner- 
vous force with frightful rapidity. Curses, like chickens, 
as the adage says, come home to roost. Rest assured, 
that unhealthy and evil habits are drafts drawn on the 
future, which must be met at no distant day. Depend 
upon it, that all Torms of sensual gratification that excite 
pleasure, only to be followed by depression, cause a great 
waste of nervous tissue, and may in time sap the very 
foundation of health and happiness. It may well be called 
“dissipation,” which dissipates or scatters a man’s nervous 
vitality, and leaves him at last a wreck of his former self. THE NERVOUS SYSTEM. 
157 
138. Stimulants and Narcotics. — There are certain 
substances used as drugs and beverages through the force 
of a depraved habit, and commonly known as “ stimulants 
and narcotics.” Thus, alcohol is said to be both a stimu- 
lant and a narcotic. Just where its stimulant action ends, 
and its narcotic action begins, is not evident. To this 
same class belong opium, tobacco, chloroform, ether, 
chloral, Indian hemp, etc., which are taken to a greater 
or less extent for their stimulating and narcotic effects. 
A person who has taken them once, has a strong inclina- 
tion to try them again. Yielding once, they beget an 
itching desire to repeat the action. This unhealthy crav- 
ing may pass away, but oftener grows fierce by what it 
feeds on. A man is no longer master of himself, but is 
the victim of a relentless craving for what may sooner or 
later destroy him. It is almost impossible for him to free 
himself from the invisible chains of his baneful habit. 
139. General Effect of Alcohol upon the Nervous 
System. — The real substance of the nerves, the great 
nerve-centres, and the brain, is made up of nerve-pulp, 
the softest and most delicate matter in the body. A rude 
touch will crush and destroy it. It is very rich in blood- 
vessels, which bring blood to renew and nourish it, and 
also to carry away the waste. This ceaseless interchange 
between the blood and the nerve-pulp maintains the vital 
action and power of the nervous system. No other part 
of the living body is so sensitive to the presence of alcohol 
as this delicate nerve-pulp. It has much water in it, to 
keep it in a moist and workable condition. Alcohol satis- 
fies its thirst by rapidly taking to itself the water of the 
nerve-pulp. Again, when alcohol is once taken up by 
the nerve-tissue, it does not easily escape. In other 158 
OUR BODIES. 
words, this unnatural agent is shut up and imprisoned in 
the nerve-structure, and is only got rid of by a gradual 
and slow process. For these two reasons, therefore, the 
nerve-tissue is peculiarly subject to the injurious effect of 
alcoholic liquors. 
140. Alcoholic Excess and the Nervous System.— 
The first symptom which deserves notice is the quickened 
action of the heart, and with it the dilatation of blood- 
vessels. The face is flushed, and there is a warm glow 
all over the body. The tiny vessels of the brain are over- 
charged, the brain becomes more active, thoughts flow 
more rapidly, and the speech becomes more fluent. 
If still more alcohol is taken, those actions of life which 
are under the direct control of the spinal cord become 
disturbed. The power over some of the muscles is lost, 
and the energy of the whole muscular system is lessened. 
The muscles of the lower lip and the legs are the first to 
feel this unnatural torpor. The speech is thick, and the 
gait uncertain. Trembling, faintness, and vomiting are 
more or less frequent. 
The nerve-pulp of the higher, or controlling, part of the 
brain is next brought within the grasp of this deadly alco- 
holic influence, and the faculties of the mind are more 
or less impaired. Reason is off duty ; and the lower, or 
animal, impulses begin to manifest themselves. First 
the control of judgment and the will * disappears ; and the 
emotional, the impulsive, and the purely instinctive part 
of our nature is laid bare. In the last stage of all, the 
paralysis of the nerve-centres and of the brain is carried 
* “Under the influence of alcohol, the weakening of the will becomes 
excessive. The extravagances, violences, and crimes committed in this 
state are innumerable.” — Dr. J. Ribot. TIIE NERVOUS SYSTEM. 
159 
to its full extent. All the inlets of the senses arc closed, 
all consciousness and sensation are lost, and > all power 
over the voluntary movements is gone. The heart still 
beats, and the blood circulates, and the breathing still 
goes on ; but these are the sole remnants of vitality, the 
slender threads by which a hold is retained upon life. 
141. The Final Result of Alcoholic Excess.—After 
a time, over-indulgence in alcohol steadily weakens the 
self-control of its hapless victim, and at last makes him 
an utter slave to his lower and animal nature.* The crav- 
ing for ardent spirit becomes well-nigh irresistible. Self- 
respect, honor, conscience, every thing, is sacrificed to get 
fresh fuel for the alcoholic fire which is burning up its 
victim. The road is now straight, which leads to some 
private “retreat,” or even the insane-asylum. 
The disease known as delirium tremens, meaning a 
trembling madness, is a terrible instance of the effect 
which alcoholic excess may exercise over the nerve-centres. 
It is marked by muscular tremors, a low temperature, cold 
and clammy skin, persistent wakefulness, muttering talk, 
then the wildest delirium, with all the horrors of hideous 
delusions which imagination can possibly conceive, f 
The extreme instances of the breaking-up of the ner- 
vous system are found in our insane-asylums, — men and 
women who have lost every attribute of humanity except 
* “O, that men should put an enemy in their mouths, to steal away their 
brains! that we should, with joy, revel, pleasure, and applause, transform 
ourselves into beasts!” — Othello, Act ii. Scene 3. 
t “The victim almost always apprehends some direful calamity; he 
imagines his bed to be covered with loathsome reptiles; he sees the walls 
of his apartment crowded with foul spectres; and he imagines his friends 
and attendants to be fiends, come to drag him down to a fiery abyss beneath.’ 
— W. B. Carpenter, M.D. 160 
OUR BODIES. 
the name; hopeless, helpless, doomed to a living death 
until they cease to be. 
142. The Inherited Craving for Alcohol. — The craving 
for alcohol may be inherited by its victim’s innocent chil- 
dren. Just as we may inherit from our parents mental and 
physical vigor or weakness, our features, and even moral 
traits, so it is possible to inherit a thirst for strong drink. 
The inherited curse of strong drink has caused many a 
good family to “run out,” and leave the children and grand- 
children pitiable wrecks of humanity. Again, the children 
of parents whose brains are injured by alcohol, are more 
prone than others to mental disease, and to those widely 
varied diseases, which, for lack of a better name, we vaguely 
call “ nervous.” * 
143. Tobacco and its Moderate Use.—The enormous 
consumption of tobacco is a matter of the commonest ob- 
servation and experience. Tobacco, as we know, is smoked, 
chewed, or used as snuff. In whatever way it is used, 
tobacco is a narcotic and a poison. Its injurious effects 
are due to its active principle called nicotine, which is of 
itself a narcotic poison. The extent to which the body 
may be injured by tobacco, depends upon its moderate or 
excessive use. Even in moderate use, it is hurtful to 
young persons, and by no means free from harm to adults. 
In mild narcotic doses, tobacco has a soothing effect upon 
the nervous system, especially of brain-workers. It pro- 
* This point has been very tersely put by a sagacious physician, the late 
Ur. Willard Parker of New York. He says, “ There is a marked tendency 
in nature to transmit all diseased conditions. Thus, the children of con- 
sumptive parents are apt to be consumptives. But, of all agents, alcohol is 
the most potent in establishing a heredity that exhibits itself in the destruc- 
tion of mind and body. There is not only a propensity transmitted, but an 
actual disease of the nervous system.” THE NERVOUS SYSTEM. 
161 
cluccs an artificial exhaustion, as it were, of the nerve- 
centres. Used in moderation, and at proper times, tobacco 
does not produce any real hurtful physiological effect upon 
a healthy adult, except so far as very small doses of any 
narcotic may do harm. It certainly does no good; and 
the tobacco habit, once acquired, generally leads to its 
excessive use. Those who have not learned to smoke do 
not miss it. The fact that the habit is foolish, costly, and 
ill-becoming, needs no physiological proof. 
144. The Excessive Use of Tobacco. — The excessive 
use of tobacco is quite another matter. When carried to 
excess, tobacco produces functional derangement of the 
nervous system, palpitation of the heart, certain forms of 
dyspepsia, and more or less irritation of the throat and 
lungs. Sometimes, after long smoking, a sudden sensation 
of dizziness, with a momentary loss of consciousness, is 
experienced. At other times, if walking, there is a sudden 
sensation of falling forward, or as if the feet were touch- 
ing cotton-wool. While the stomach is empty, protracted 
smoking will often produce a feeling of nausea, accom- 
panied with a headache.* The excessive use of tobacco 
may affect the brain. The ideas lack clearness of outline. 
The will-power may be weakened, and it may be an effort 
to do the routine duties of every-day life. The old tobacco- 
* The external application of tobacco to chafed surfaces, and even to the 
healthy skin, will occasion severe, and sometimes fatal, results. A tea made 
of tobacco, and applied to the skin, has caused death in three hours. A 
tobacco enema has resulted fatally within a few minutes. The excessive 
smoking of tobacco at one time has been known to produce violent, and even 
fatal, effects. Nicotine is one of the most rapidly fatal poisons known. It 
rivals prussic acid in this respect. It takes about one minute for a single 
drop of nicotine to kill a full-grown cat. A single drop has killed a rabbit 
in three minutes. 162 
OUR BODIES. 
user is often cross, irritable, and liable to outbursts of pas- 
sion. The memory is also quite often impaired for the 
same reason. The narcotic principle, the deadly nicotine, 
has become soaked into the delicate nerve-pulp retarding 
its nutrition. The nerve-centres are no longer able to 
hoard up their usual amount of vital energy. Hence arise 
the many and various nervous symptoms due to the abuse 
of tobacco. 
145. Effect of Tobacco upon Young People. — To- 
bacco, in any form, has a peculiarly injurious effect upon 
young and growing persons.* It not only stunts their 
growth, but produces a weakened state of the system, 
which tends greatly to impair muscular and mental ac- 
tivity. The profound effect that tobacco has upon the 
nervous system, after the first trial of smoking or chew- 
ing, is matter of familiar experience. Even after the sys- 
tem gets used to the narcotic, young people continue to 
suffer oftentimes from nausea, dizziness, headache, muscu- 
lar trembling, loss of appetite, and general weakness. The 
use of cigarettes by young persons cannot be too severely 
condemned. They are made of the meanest materials, 
and often “doctored” with refuse substances, and even 
forms of opium, in order to give some bulk and “tone” 
to the originally cheap and filthy material. Cigarettes 
arc so common and so cheap, that their use to an injurious 
* The evils of tobacco are intensified a hundred-fold upon the young. 
Here it is unqualifiedly and uniformly injurious. It stunts the growth, 
poisons the heart, impairs the mental powers, and cripples the individual 
in every way. Not that it does all this to every youth, but it may be safely 
asserted that no boy of twelve or fourteen can begin the practice of smoking 
without becoming physically or mentally injured by the time he is twenty-one. 
Sewer-gas is bad enough, but a boy had better learn his Latin over a man- 
trap than get the habit of smoking cigarettes.—New-York Medical Record. 163 
THE NERVOUS SYSTEM. 
extent by thousands of young people is really a matter of 
great practical importance at the present clay. No young 
person should learn to smoke, especially if he wishes to 
keep strong and vigorous, is ambitious, and eager to suc- 
ceed in life. 
146. Opium. — Opium, the most valuable of all medi- 
cines, is the dried juice of the white poppy. It has the 
wonderful power of relieving pain, and producing a kind 
of sleep. For this purpose it is indispensable to the phy- 
sician. Morphine is a white powder made from opium. 
When opium is soaked in alcohol, it is called laudanum. 
Paregoric is a weak form of opium combined with other 
things. Dover’s powder is made of opium and ipecac. 
The various forms of opium are very generally used in 
patent medicines. They form the “soothing” basis of lini- 
ments, “cough-killers,” “soothing-sirups,” stomach-bitters, 
cholera-mixtures, and countless other preparations, which 
people are eager to buy, hoping to get relief from some 
real or fancied disease. 
Thousands of tons of opium are smoked and chewed, 
like tobacco, in distant parts of the world, especially in 
China. This habitual use of opium is, however, a com- 
mon vice everywhere. Over half a million pounds were 
imported into this country in 1883, and a large propor- 
tion of this enormous quantity was consumed by “ opium- 
eaters.” When used by physicians to relieve pain, opium 
leaves its after-effects in dryness of the mouth, thirst, 
nausea, constipation, and a dull headache. In large or 
poisonous doses, there are giddiness and stupor. A per- 
son becomes motionless and insensible to outward impres- 
sions ; he lies quite still, with the eyes shut, and the pupils 
contracted ; and the whole expression of the countenance 164 
OUR BODIES. 
is that of deep and perfect repose. As the poisoning ad- 
vances, the features become ghastly, the pulse feeble, and 
the muscles greatly relaxed ; and, unless help is procured, 
death speedily ensues. If the person recovers, the insensi- 
bility is succeeded by sleep for one or two days, followed 
by nausea, vomiting, and loathing of food. Opium may be 
at once a blessing or a curse to mankind. Used with skill 
by a good physician, it performs wonders in relieving pain. 
Eaten or smoked habitually to satisfy a craving for it, 
opium makes a living death for its victim. A person may 
begin in the most innocent way to use a little opium to 
relieve pain : little by little, the meshes of this fascinating 
narcotic are woven about him. The opium relieves the 
suffering, and gives a soothing stupor, and even pleasant 
dreams and visions. The worst of it is, a person cannot 
leave off its use without the greatest effort. A craving is 
created which no one can realize unless he has once been 
within the fascinating toils of this wonderful drug. It is 
untold misery to quit it, and sure death to keep on using it. 
It completely changes its victim. A man, once upright 
and honest, will lie, cheat, defraud, or even murder, to get 
a dose of the fatal drug. Promises and resolutions to stop 
its use may be honestly made, but are no more binding 
than ropes of sand. The deepest melancholy settles on 
the opium-eater ; and life, once full of joy and happiness, is 
indeed a heavy burden. He would gladly commit suicide, 
but his very habit unfits him to summon the will-power to 
do the deed. Meanwhile all the vital organs are slowly 
and surely losing the power to do their work. The fat 
disappears; the muscles grow weaker ; the stomach and 
bowels fail to act; the skin becomes dry, yellow, and 
shrivelled, like yellow-leather parchment; and death at 
last puts an end to his earthly misery. THE NERVOUS SYSTEM. 
165 
147. Practical Points about Opium. — The utmost care 
should be taken in giving infants and children any of 
the so-called soothing-sirups, cough and cholera mixtures. 
There is almost sure to be more or less of some form of 
opium in them.* The child is simply drugged, and not 
cured, however “soothing” the effect may be. The only 
safe rule is, never to put opium on the list of home-reme- 
dies. A good physician often hesitates to use this drug 
with children, for he knows how dangerous and uncertain 
the effect may be. The practice of rubbing the gums of 
teething-children with paregoric, putting laudanum into a 
child’s aching tooth or ear, giving either preparation for 
“summer complaints,” and other household ways of using 
opium, should be very sparingly and very cautiously resorted 
to. Nine times out of ten, some simple and safe remedy 
will answer every purpose. Never rub any form of opium 
powder upon any abraded surface to relieve pain. It is 
rapidly taken up by the blood. “Dover’s powder” is not 
a home-remedy : a single grain has killed an infant. Re- 
member that laudanum that has been kept in the cupboard 
for a long time may become stronger, on account of the 
evaporation of the alcohol. Remember that children as a 
rule, and many grown-up people too, are very susceptible 
to the action of opium. It is well known that a child may 
be drugged by the milk of a nurse who has taken opium. 
Young boys have been made stupid, getting even the “pin- 
hole pupil,” by smoking cigarettes in excess that have 
been doctored with opium. Poultices saturated with 
laudanum are by no means safe. They are especially dan- 
gerous in the case of infants. 
* It is very certain that many infants annually perish from this single 
cause. — Reese’s Manual of Toxicology. 166 
OUR BODIES. 
The only safe rule, therefore, is to let every thing that 
has opium in it severely alone, unless it is ordered by the 
trusted family physician. Above all things, do not “ pass 
round ” to others, especially children, any opium-mixture 
that has been prescribed or used by some one else. It is 
better to endure pain.* 
148. Chloral. — Chloral is a powerful drug, capable, in 
small doses, of producing quiet sleep. This action is 
probably due to its direct action upon the brain. In full 
doses it acts to depress the action of the nerve-centres of 
the brain and spinal cord. In large doses, there is paraly- 
sis of the nerve-centres, causing death. Because chloral 
is known to induce sleep, especially in those who suffer 
from excessive mental strain, or from anxiety, or other 
like cause, it has come, of late years, to be often used 
without a physician’s advice. Like all narcotics, the dose 
must be steadily increased to get the required effect. The 
“chloral habit ” is soon formed, and the person becomes a 
slave to a dangerous drug. Without it, the chloral-eater 
cannot sleep : with it, his digestion is sadly out of order. 
He suffers from dyspepsia, shortness of breath, and palpi- 
tation of the heart. The habit begets carelessness in its 
use ; and the fatal dose is so uncertain, that chloral-eaters 
often die from an overdose. The only safe rule is, never 
to touch so powerful, uncertain, and dangerous a drug 
unless prescribed by a skilled physician. 
149. Oth er Narcotics. — Regarding chloroform, ether, 
* The system learns to tolerate opium after a time. Opium-eaters get 
used to taking enormous quantities. De Quincey, the famous author and 
opium-eater, used to drink more than half a pint of laudanum a day. 
About fifteen drops is the ordinary dose. The student should read parts of 
his weird bonk, called the Confessions of an Opium-Eater. THE NERVOUS SYS TEAL 
167 
hasheesh, or Indian hemp, and other narcotics, it may be 
said, once and for all, that they should never be used 
repeatedly or continuously, even in the smallest doses, 
unless under medical advice. They are valuable remedies 
in the treatment of disease, but dangerous agents at all 
times. They are used with great caution, even by physi- 
cians. Persons who get into the habit of tampering with 
such powerful drugs run the ever-present risk of killing 
themselves by an overdose. Inhaling ether or sniffing 
chloroform on a handkerchief, as a household remedy, to 
relieve spasms of pain, should be always severely con- 
demned. Familiarity with these and all other powerful 
drugs and narcotics is sure to beget carelessness on the 
part of those who use them on themselves.* 
Collateral Reading. Wood’s Brain-work and Overwork, “ American 
Health Primers; ” The Nervous System, “ Health Primers ; ” Mace’s The Little 
Kingdom. 
Collateral Reading (for advanced pupils). Le Pileur’s Wonders of the 
Human Body; Kingsley’s Health and Education ; Oswald’s Physical Education; 
Black’s Ten Laws of Health ; McSherry’s Health, and How to Promote it. 
TEST QUESTIONS FOR REVIEW. 
1. Show how the various parts of the body act in harmony. 
2. Draw a parallel between the nervous system and the telegraph. 
3. Give familiar illustrations to show the general action of the ner- 
vous system. 
4. What are the two distinct systems ? 
5. What is nerve-tissue ? 
* Even physicians, used to handling opium and other poisons in their 
practice, have died from an overdose of morphine, chloral, etc., after they 
became victims to the use of these narcotics. 168 
OUR BODIES. 
6. What are the nerves ? 
7. Give a short description of the brain. 
8. What is the usual size of a human brain? 
9. Describe fully the cerebrum, or brain proper. 
10. What are the functions of the cerebrum? 
11. Describe the three coverings of the brain. 
12. Locate and describe the cerebellum. What is its function ? 
13. Describe the medulla oblongata. What are its functions ? 
14. What do you understand by the cranial nerves ? 
15. How are they arranged? What is the pneumogastric nerve? 
16. Describe briefly the spinal cord. What are its functions? 
17. Explain fully what you understand by reflex action. 
18. Give several familiar examples to illustrate reflex action. 
19. Describe the importance of reflex action. 
20. What are the spinal nerves? Explain motor and sensory nerves. 
21. Describe the sympathetic system of nerves. 
22. What are the functions of the sympathetic nerves ? 
23. Why is sleep necessary ? 
24. Give some practical hints about sleep. 
25. What tends to keep the nervous system in good order? 
26. What about the abuse of the nervous system ? 
27. Explain what is meant by stimulants and narcotics. 
28. What is the general effect of alcohol upon the nervous system? 
29. What is the effect of alcoholic excess ? 
30. Describe the final results of alcoholic excess. 
31. What can you say of the inherited thirst for alcohol? 
32. Describe what is meant by “delirium tremens.” 
33. What can you tell of the moderate use of tobacco? 
34. Why is tobacco especially hurtful to young people ? 
35. What about its excessive use? 
36. Show how tobacco may be a deadly poison. 
37. Opium. What is it? for what used? what about the opium habit? 
38. Give some practical hints about opium. 
39. What about chloral ? other narcotics ? THE SPECIAL SENSES. 
169 
CHAPTER X. 
THE SPECIAL SENSES. 
150. Sensation.—In the preceding chapter, we have 
seen that all nerves belong to two classes, — motor nerves, 
which control the action of the muscles of the body; 
sensory nerves, which carry a variety of impressions from 
all parts of the body to the brain. When the brain 
receives a certain impression by means of some sensory 
nerve, we become conscious of a feeling, or sensation. Ex- 
actly how we become conscious of the thousand and one 
sensations felt by all, is one of the many mysteries con- 
nected with the human body. Some sensations, such as 
those of faintness or fatigue, spring up within us in some 
mysterious way, without any apparent cause. Most sen- 
sations, however, are produced by some stimulus, or out- 
ward agency. Thus, if we hear a child cry, or a bird sing, 
we have a sensation of sound. If we are pinched, tickled, 
or struck, we have a sensation corresponding to these acts. 
If we put a piece of sugar on the tongue, hold a rose at 
the nose, or prick the skin with a pin, certain sense-organs 
receive the impressions, and the sensory nerves carry them 
to the brain, where we become conscious of a sensation. 
Sensations may be those of pleasure or pain. Indeed, the 
same agent may be either pleasant or painful, according 
to. its degree of intensity. It is pleasant to hold out the 170 
OUR BODIES. 
hands before a glowing fire after a cold ride. Hold the 
hands too closely, and the sensation of pleasure is changed 
in a moment to one of pain. 
All sensations are produced by three distinct organ- 
isms : — 
1. An organ specially adapted to receive the stimulus 
from the outer physical agent. 
2. An incoming, or sensory, nerve to carry the impres- 
sion from the sense-organ to the brain. 
3. The brain itself, some part of which converts the 
impression into an actual sensation to the mind. 
Take, for instance, the sense of hearing. The waves 
of sound pass through the air from the outer physical 
agent. The ear is the organ specially adapted to receive 
impressions from it. The nerve of hearing, or auditory 
nerve, forms the connection between this organ and the 
brain, where the consciousness of sensation actually takes 
place. 
151. The Five Special Senses. — There are five ways 
in which the brain becomes acquainted with what takes 
place in the outer world. In other words, there are cer- 
tain sets of nerves which carry special sensations to the 
brain. We are said to have five special senses,* or 
“gateways of knowledge,” — touch, taste, smell, hearing, 
and sight. > 
152. Touch, or Feeling. — The sense of touch is the 
most widely extended of all the senses, and perhaps the 
* Thei'e is another sense, commonly called the muscular sense, which 
enables us to judge the weight of different bodies, according to the muscular 
effort required to lift or hold them. This sense becomes so highly developed 
with use, that shopkeepers and others who sell various articles by weight, 
will often tell you the weight of a body by simply balancing it in their hands. THE SPECIAL SENSES. 
171 
simplest. It has its seat in the skin all over the body, 
and in the walls of the mouth and nasal passages. By 
this sense of touch, we tell whether a body is hard or soft, 
hot or cold, rough or smooth. We have been told in 
another chapter (Sect. 113) of the thousands of tiny hil- 
locks called papillcs, and forming rows of ridges very thick 
on the tips of the fingers (Fig. 46). Now, besides a tiny 
artery and vein, finer than the finest 
hair, there is in each papilla the end of 
a sensory nerve. Where the sense of 
touch is most delicate, the papilla is 
found to contain a little oval bulb 
called the touch-corpuscle. All parts 
of the body do not have this sense of 
touch in an equal degree.* It is most delicate in the 
tip of the tongue, the tip of the fingers, and the edge 
of the lips ; and least delicate in the middle of the back 
(Expers. 94, 95). 
153. Taste. —The tongue is the principal organ of taste. 
The tongue has two coverings,—a deep, sensitive layer, 
and an outer layer. When the stomach is out of order, and 
in certain diseases, this outer layer becomes coated with a 
whitish or yellowish matter. We generally speak of the 
tongue at such a time as being furred. The deep layer 
Fig. 46. — Three Papillae 
of the Skin. 
* There is no sense so capable of improvement as that of touch. The 
female silk-weavers of Bengal are said to be able to distinguish, by the touch 
alone, twenty different degrees of fineness in the unwound cocoons, which 
are sorted accordingly. 
The sense of touch may be said to belong to every animated being, and 
is one great characteristic of animal life. In many animals the tongue is 
the instrument of touch as well as of taste. Certain animals, in addition to 
the tongue, have special organs of touch, as the whiskers of the cat and 
rabbit. 172 
OUR BODIES. 
is raised up, like the true skin, into tiny hillocks, or 
papillae, which are abundantly supplied with delicate nerve- 
fibres from two great nerve-branches leading from the 
brain. These are the nerves of taste. The tip and back 
of the tongue are supplied with different nerves. The 
papillae are small, and pointed on the tip, and arranged 
in the form of a letter V, with the point towards the back. 
Hence it makes a difference in 
the taste, whether we put a 
substance to be tasted on the 
tip or back of the tongue. 
Thus, alum tastes acid on the 
tip, and has a sweetish taste 
on the back part, of the tongue. 
In certain animals, these last- 
mentioned papillae are very 
largely developed, and give a 
roughness to the tongue. We 
have all, no doubt, noticed how 
rough a dog’s tongue is. It 
is this which enables the dog 
to strip off the flesh from a 
bone by simply licking it ; 
while the lion by the same 
means strips the skin from 
any part of the human body with one stroke of his tongue 
(Expers. 96, 97, 98, 99). 
In this sense, as in the other senses, the nerves receive 
the impression, and carry it to the brain, where it is per- 
ceived, and gives rise to the sensation of taste. 
154. Smell. — The seat of the sense of smell resides in 
the cavities of the nose, into which the nostrils open, and 
EPIGLOTTIS 
PAPILUE 
Fig. 47. — Upper Surface of the Tongue, 
showing the Papillae. THE SPECIAL SENSES. 
173 
which open behind into the pharynx, or the back part of 
the mouth. The walls of the nasal cavities are lined with 
a thick, velvety membrane, over which the nerves of 
smell are distributed. This membrane is kept continu- 
ally moist by a fluid which it secretes. At the beginning 
of a cold in the head, this membrane becomes dry and 
OLFACTORY NERVE 
/.BRANCHES OF 
/olfactory NERVE 
NASAL_ 
BONE j 
INTERIOR OF 
NOSTRIL 
Fig. 48. — The Organ of Smell. 
swollen, and the sense of smell is greatly lessened. It is 
in the roof of the nasal cavities that the sense of smell 
is most acute.* Hence, when we wish to detect a faint 
* The sense of smell varies very much in different individuals. Among 
civilized people, it is rather defective; while, in savage races, it is most 
acute. We are told that the South-American Indians can detect the ap- 
proach of a stranger, even in a dark night, by their sense of smell, and 
can also tell whether he is white or black. Many animals are more highly 
endowed with this sense than man. Thus, a dog will smell the footsteps of 
his master amid those of a hundred other people, and can trace him for 
miles, although he has been for hours out of sight. Pointers also scent 
game at a great distance. 174 
OUR BODIES. 
odor, we sniff up the air sharply. By doing so, we cause 
a rush of air into the higher parts of the cavities, where 
some of the floating particles come into contact with the 
nerves of smell. 
The sense of smell is Nature’s sentinel to guard us 
against taking improper food into our stomach, and im- 
pure air into our lungs. By this same sense, we are able 
to detect delicate and fragrant odors, which add much to 
the comfort of our daily living (Expers. 100, 101). 
155. The Sense of Hearing. — We come now to a 
special sense, which does not tell us what is going on in 
the outer world by actual contact, as in touch or taste, 
nor by particles of matter falling upon the end of nerves, 
as in the sense of smell. In this sense, impressions are 
produced upon nerves by wave-like vibrations in the sur- 
rounding air. This is the sense of hearing, only second 
in importance to the sense of sight. All sounds arc 
produced by the vibration of some body in the atmosphere. 
The body sends out these vibrations to the surrounding 
air, which carries forward a series of waves in all direc- 
tions.* 
These air-waves are received, and the impression made 
by them is sent to the brain, by a special apparatus, called 
the organ of hearing. 
The organ of hearing is lodged in the thick, inner bones 
forming the base of the skull. The ear, the organ of hear- 
* We shall understand these air-waves better if we throw a stone into a 
pool of water, and watch the result. We see a series of tiny, circular ripples 
gradually spread themselves over the surface of the water from the spot 
where the stone fell. This exactly represents the waves of sound caused 
by the vibration of bodies in the air. These air-waves travel with wonderful 
rapidity. The usual velocity of sound is about eleven hundred feet a second. THE SPECIAL SENSES. 
175 
ing, is far more complicated than any of the organs of 
sense yet described. It is divided into three parts, — the 
outer, the middle, and the inner ear. 
156. The Outer Ear. — The outer ear consists of a 
broad plate of gristle, shaped somewhat like a shell, com- 
monly called “the ear;” and of a tube about an inch long, 
called the auditory canal. This canal is hewn out of the 
solid portion of the temporal bone. It is protected by fine 
hairs, and by a set of glands which secrete ear-wax, a bit- 
ter substance, which serves to moisten the parts, catch 
particles of dust, and keep away small insects. The inner 
end of this canal is closed by a membrane stretched 
tightly across it. It resembles the parchment stretched 
across the end of a drum, and is known as the membrane 
of the drum of the ear. It is thin and elastic, but may be 
easily broken by a blow, or by pushing any thing into the 
ear. If once broken, this delicate membrane cannot be 
repaired, and deafness results. 
157. The Middle Ear. — The middle ear is a small cavity 
hollowed out in the temporal bone, between the membrane 
of the drum and the inner ear. This cavity is the “drum” 
of the ear. The most curious feature of the drum is a 
string of three of the tiniest bones, which stretch across 
it. They are called malleus, or the hammer, incus, or the 
anvil, and stapes, or the stirrup,* from some fancied re- 
semblance to these articles. The hammer-bone is fastened 
by its long handle to the membrane of the drum. The 
round head of the hammer fits into the anvil-bone. Next 
to the anvil is the stirrup-bone, which fits into a little 
oval window in the opposite wall of the chamber, or drum. 
* The “ stirrup ” is the smallest bone in the hyman body, its entire length 
being one-eighth of an inch. 176 
OUR BODIES. 
In the floor of this chamber is the opening of a passage 
called the eustachian tube * (Fig. 49). 
This tube is about an inch and a half long, and leads 
into the throat. It allows air from the throat to enter the 
drum, and serves to keep the air on both sides of it at a 
constant and even pressure.! To hear perfectly well, this 
passage must be kept open for the air to pass in and out. 
During a severe cold in the head, or a sore throat, the 
Fig. 49. — Sectional View of th*i Ear. 
lining of the tube may be inflamed and swollen. This 
gives the stuffed feeling and alteration of sounds in the 
ears. This stuffed feeling should not be neglected if it 
does not pass off in a few days. Should it continue, 
* Named after Eustachi, a famous Italian anatomist, who died more than 
three hundred years ago, and who first described it. 
t This passage is ordinarily closed; but when the orifice in the throat is 
opened, as in the act of gaping or swallowing, the air rushes into the cavity 
of the tympanum. Close the mouth, and pinch the nose, and then try to 
force air through the latter. Air is thus forced through the eustachian tube. 
A distinct crackle or clicking sound is noticed, due to the vibration of the 
membranes, and the movements of the little bones of the ear. THE SPECIAL SENSES. 
177 
it will show that more than ordinary swelling has occurred 
in the tube; and it will be found that the hearing is slightly 
impaired. 
Usually, as the cold passes off, this peculiar feeling in 
the ears passes away. 
158. The Inner Ear.—The inner ear is one of the most 
delicate and complex pieces of mechanism in the whole 
body. It is that part of the organ of hearing which per- 
ceives the impression of sound, and carries that impression 
directly to the brain, where it gives rise to the sensation 
of hearing. It is really a bony case filled with water, in 
which float the delicate parts of the inner ear. The inner 
ear consists of three distinct portions, — the vestibule, or 
hall-way, the semicircular canals, and the cochlea, or snail’s 
shell. It is enough to say, that these are winding chan- 
nels and spiral tubes hollowed out in the solid bone. The 
whole system of passages is known as the “labyrinth.” It 
is important to remember, that there is a continuous con- 
nection between all the passages of the inner ear, and 
that all the winding tubes and chambers enclose and pro- 
tect a delicate bag of membrane of exactly the same shape 
as themselves. The auditory nerve, or nerve of hearing, 
passes from the brain, through a little hole in the solid 
bone of the skull, to the inner ear, and is spread out on 
the membranous lining. 
159. How we hear.—Let us try and understand a few 
of the simplest principles of this wonderful mechanism of 
the ear. A bell is rung, or a gun fired. The vibration is 
communicated to the atmosphere around it, and passes 
away in air-waves from the sounding body, as the waves 
ripple the surface of a pond after a stone has been thrown 
in. The air-waves go into the outer ear, and strike upon 178 
OUR BODIES. 
the stretched membrane of the drum, and cause it to 
vibrate. At every vibration of the membrane, the head 
of the hammer-bone strikes upon the anvil-bone, drives it 
forward, and pushes the foot-plate of the stirrup-bone in 
and out of the oval window on the inner wall of the cham- 
ber. The watery fluid in the inner ear washes tiny grains 
of sand against the membranous bag, and so strikes 
the ends of the auditory nerves. These nerves flash the 
impression they have received to the brain. It is in 
the brain itself that the sensation of hearing takes place. 
160. Care of the Ear.—The ear is a very delicate 
organ, It is often carelessly and ignorantly tampered 
with, when it should be let alone. It is often neglected 
when skilled treatment is urgently needed. The ear-canal 
should never be rudely or hastily washed out, either with 
a syringe or a wash-rag. The utmost gentleness in wash- 
ing out the ear is all that is necessary for cleanliness. 
Children’s ears should never be pulled or boxed.* Even 
a slight blow has resulted in serious trouble. 
Never use ear-picks, ear-spoons, the end of pencils or 
pen-holders, pins, hair-pins, tooth-picks, towel-corners, etc., 
to pick, scratch, or swab out the ear-canal. It is a foolish, 
needless, and dangerous practice. There is always risk 
that the elbow may be jogged in many ways, and the 
pointed instrument pushed through the drum-head. Let 
the ear-wax take care of itself. The skin of the ear grows 
outward, and the extra wax and dust will be naturally 
* Thus, a “ box on the ear,” a blow on the ear or head of any kind, or a 
fall, may be the direct cause of permanent deafness. Sometimes the deaf- 
ness is total as well as sudden. 
Deafness from concussion, as a tumble down-stairs in childhood, or from 
a severe blow of any kind on the head, may be the foundation of deaf-dumb- 
ness, if the injury occur before the child has learned to talk. THE SPECIAL SENSES. 
179 
carried out if let alone. Never drop sweet-oil, glycerine, 
and other fluids into the ear, with the idea that the ear 
is cleaner for them. They do no good, and often irritate 
the ear. Never advise or allow any of the many nonsen- 
sical things so commonly used, to be put into the ears to 
cure deafness. Cotton wads may be gently put into the 
ears to shield them from the cold, or may be worn in 
swimming or diving, to keep the water out. Diving into 
deep water, or bathing in the breakers, often injures the 
ears. Alcohol used in excess often injures the ears by 
inflaming the throat, and thence the eustachian tube and 
middle ear. Tobacco in all its forms is apt to produce 
catarrh of the throat and nose, and hence ear-disease. 
One should never shout suddenly in a person’s ear. The 
ear is not prepared for the shock, and deafness has occa- 
sionally resulted. If the eustachian tube is closed for the 
time, a sudden explosion, noise of a gun or cannon, may 
burst the drum-head. Soldiers during heavy cannonading 
open the mouth to allow of an equal tension of air. Flies, 
bugs, ants, and the like, often crawl into the ear. This 
may cause some pain and fright, and perhaps lead to 
vomiting, and even convulsions with children. A lighted 
lamp put at the entrance of the ear will often coax insects 
to crawl out towards the light. The ear may be syringed 
out with a little warm water. Drop in a few drops of 
molasses or warm sweet-oil. When the ears run for any 
cause, it .is not best to plug them with cotton wads. It 
only keeps in what should come out. Cold water should 
never enter the ears or nostrils if it can be helped. Use 
only tepid water. Do not go to sleep with the head on 
the window-sill, or in any position that may expose the 
ears to a draught of cold or damp air. 180 
OUR BODIES. 
161. The Sense of Sight. — Sight, or vision, is a 
wonderful thing when we come to think about it. That 
we have a means by which we can tell what is going on 
in the outside world, miles away from us, is a precious 
gift. We watch a huge balloon from the time it leaves 
the ground till it is a mere black speck in the atmosphere 
above us. We follow the vessel sailing along on the dim 
horizon, and the next instant we are reading the fine print 
of a newspaper. We recognize the form, size, color, and 
distance of thousands of different objects in nature every 
day of our lives. This sense is so woven into the count- 
less acts of our every-day affairs, that we scarcely appre- 
ciate this marvellous gift, so essential, not only to the 
simplest matters of comfort, but also of prime impor- 
tance in the culture of the mind and the higher forms of 
pleasure. Sight is well held to be the highest and most 
perfect of all the senses. 
162. The Eye. — The eye is the outer instrument of 
sight, and is a most beautiful and ingeniously built object. 
This little organ, only about an inch in diameter, easily 
balanced on the forefinger, is in reality one of the greatest 
wonders in nature. The eyeball is lodged in a hollow 
cone made up of seven little bones, with the base pointing- 
outwards and forwards. This eye-socket, or orbit, is well 
protected on its edges by the dense and strong bones of 
the head. The eyeball rests in a soft and elastic bed 
of fat, which supports and protects it, and, at.the same 
time, allows it to move in all directions as freely as if it 
floated in water (Exper. 103). 
163. The Coats of the Eye. — The walls of this hollow 
eyeball are made up of three distinct coats, or coverings, 
— the sclerotic, the choroid, and the retina (Fig. 50). The THE SPECIAL SENSES. 
181 
outer covering is the sclerotic, or hard coat. It is gener- 
ally spoken of as the “white of the eye.” It is one of the 
toughest and strongest membranes in the body, and is 
intended to protect the delicate structures within. It 
is so strong, that a sheep’s eyeball may be trodden on 
with all the weight of the body, without being made 
to burst by the pressure. The sclerotic gives place in the 
front of the eye to a transparent circular plate, just as 
in a watch the gold or silver case gives place to a glass 
Fig 50.—Section of Eyeball. 
crystal over the face. This transparent plate is the 
cornea, meaning “a horn.” It forms a kind of rounded 
window for the eye.* The polish and transparency of the 
cornea are kept up by frequent, unconscious winking, 
which keeps it moist, and free from dust. 
The second coat, the choroid, meaning “ under the 
skin,” is just under the sclerotic. It is much more deli- 
* The cornea can be best seen by looking at it from the side, or by see- 
ing the reflection of a window-sash upon its surface. We usually look 
directly through it, and see only the colored iris behind. 182 
OUR BODIES. 
cate in structure, and is rich in blood-vessels and nerves. 
It is lined with a thick black coating, designed to absorb 
the surplus rays of light, which would otherwise cause a 
blurred or confused vision. 
The retina, meaning “a net,” the innermost coat of 
the eyeball, is an extremely delicate film, which covers the 
inner surface of the choroid. It is a sensitive network, 
made up of fibres proceeding from the optic nerve, spread 
out over the inner surface of the eye.* It is the retina 
that makes the eye sensible to light, so that we may well 
call it the actual or essential organ of sight. 
164. The Inside of the Eye. — To get a clear idea of 
the inside parts of the eye, let us imagine an eyeball cut 
through the middle from above downwards. Let us now 
start in front, and go backwards (Fig. 50). We shall first 
see the cornea, which has just been described. We now 
reach a space called the front chamber of the eye. In this 
chamber, and behind the cornea, hangs down a curtain, the 
iris, meaning “rainbow.” It has a hole through its centre 
called the pupil, poetically called “the apple of the eye.”f 
It is this curtain which gives the color to the eye. The 
iris has muscular fibres which expand and contract, and 
thus make the pupil larger or smaller, according as the 
light is bright or dull. When the light is very strong and 
brilliant, the iris spreads its curtain farther over the pupil 
in order to shut out some of the rays. When the light 
is faint, the curtain is drawn back from the pupil in order 
to admit as many rays of light as possible. The black 
* The retina is a film only of an inch thick, yet ten distinct layers 
have been described. 
t “Let not the apple of thine eye cease.” — Lam. ii. 18. See also Ps. 
xvii. 8, Prov. vii. 2. THE SPECIAL SENSES. 
183 
appearance of the pupil is due to the thick black coating 
which lines the inside of the choroid. It is like looking 
through a small window into a room in which the walls 
are hung with black paper. 
Just behind the iris is a clear, transparent, jelly-like 
body, called the crystalline lens. It is convex, or rounded, 
both back and front, and is about one-third of an inch in 
diameter. It is shut up in a kind of transparent bag, and 
is held in its place by a number of little bands. The 
crystalline lens separates the front chamber of the eye 
from the back chamber. The front chamber is filled with 
a clear, watery fluid called the aqueous, or watery, humor. 
The back chamber also contains a jelly-like fluid called the 
vitreous, or glassy, humor.* This fluid keeps the cornea 
uniformly convex, and allows the curtain with a hole in it 
— the iris — to float and move at freedom (Exper. 105). 
165. Mechanism of Vision. — Let us now trace the 
course of the rays of light going from any luminous body 
— a lighted candle, for example — through the different 
parts of the eye. Imagine the candle to be placed at 
about the ordinary distance of distinct vision (about ten 
inches) in the front of the eye. Some of the rays fall 
on the outer coat, or the “white, of the eye,” and, being- 
reflected, take no part in vision. The more central rays 
fall upon the cornea. Some of these are reflected, giving 
to the surface of the eye its beautiful, glistening appear- 
ance. Other rays pass through it, are brought nearer 
* This glassy humor, even in healthy eyes, contains little bodies called 
“flitting flies,” which sometimes frighten people who notice them, greatly 
magnified, moving up and down like strings of tiny bright beads. They are 
more plainly seen when looking at the bright sky or a white ceiling. They 
are in every eye, and can do no harm. 184 
OUR BODIES. 
by refraction, and enter the aqueous humor, which also 
slightly bends them. Those which fall on, and pass through, 
the outer part of the cornea, are stopped by the iris, and 
are either reflected or absorbed by it. Those which fall 
upon its more central part pass through the pupil. 
Now, if the rays of light passed directly to the retina, 
they would pass in parallel lines, and produce the impres- 
sion of light, but every thing would be dim and confused. 
Therefore it is necessary that the rays coming from any 
object should be brought together (converged) by being 
bent (refracted). That is, they must be refracted, and 
brought to a focus. This is done to a certain extent by 
the cornea and the fluids, or “humors,” of the eye, but 
mainly by the crystalline lens. This is a familiar fact in 
the use of any optical instrument. The boy changes the 
focus of his spy-glass by pulling its tubes in or out. When 
the lady looks from a distant to a near object with her 
opera-glass, she changes the focus by turning the adjust- 
ing-screw. 
Now, it is the duty of the crystalline lens to bring the 
rays of light together as they pass through it, and to bring 
them to a focus on the retina. A tiny muscle, called the 
ciliary, or hair-like, muscle, does for the eye what the 
adjusting-screw does for the opera-glass. As it contracts 
and relaxes, the elastic lens, held in its place by delicate 
cords, becomes more rounded or flatter, just as we may 
wish to look at distant or near objects. Suppose we wish 
to look at an object close at hand. The little muscle 
contracts ; and the layers of membranes, between which 
the lens lies, are the least bit relaxed ; and, because it is 
elastic, the lens becomes more rounded, or convex, thus 
bringing the rays of light to a proper focus. If we wish to 185 
THE SPECIAL SENSES. 
look at any object a long distance off, the membranes are 
drawn tight by the muscle to which they are tied, and 
the lens is flattened. In other words, our eyes adjust, 
or accommodate, themselves to the varying distances of 
objects ; just as the photographer pushes in or out the 
lens of his camera with his hand, so as to bring it farther 
or nearer from the surface which receives the image. 
The rays of light are now ready to be brought to a 
focus on the sensitive retina. The iris has regulated with 
wonderful skill the proper amount of light ; and the lens, 
LEVATOR SUPERIOR 
wPULLEV 
SUPERIOR REQTUSV. 
SUPERIOR OBLIQUE 
yTARSAL CARTILAGE 
internal RECTUS' 
OPTIC NERVE' 
'EXTERNAL RECTUS 
Fig. 51. — Muscles of Eyeball: the External Rectus Muscle divided to show the Optic Nerve, 
which has been also cut to show the Internal Rectus Muscle. 
INFERIOR RECTUS' 
'INFERIOR OBLIQUE 
with the greatest exactness, has focussed the rays on the 
retina. The dark surface of the choroid coat acts to absorb 
the excess of light, and thus prevent the reflection which 
would disturb accurate vision. As a result, an exact but 
inverted image is formed on the retina. The impression 
is carried to the brain by the fibres of the optic nerve, 
which are spread out on this wonderfully sensitive mem- 
brane (Expers. 104, 108, 109, 110, 111, 112). 
166. The Muscles of the Eye. — The eyeball is rolled 
and moved about by six muscles. They spring from the 186 
OUR BODIES. 
back part of the bony orbits, and are fastened to the front 
part of the eyeball by means of cords. Four of these 
muscles — the recti or straight muscles — move the eye 
up or down, and to the right or left. The other two, the 
oblique, are so fastened, that they turn the eyeball in 
one direction or another. Sometimes one or more of 
these muscles pull unequally, and a “squint” or “cross- 
eye” is produced (Fig. 51). 
167. The Eyelids and Eyebrows.—The eye, delicate 
organ that it is, is protected and kept clean by its eyelids, 
eyelashes, and eyebrows. The eyelids are thin, flexible 
covers, or shutters, which protect the front of the eyeballs. 
They are thin plates of gristle covered with skin. They 
are lined on the inner side with a very delicate membrane 
called the conjunctiva, because it is also joined to the eye- 
ball by a fold.* It pours out an oily fluid to prevent 
friction between the surfaces. This fluid, together with 
a constant flow of tears, keeps the cornea moist, and free 
from dust. The edges of the eyelids are provided with a 
fringe of fine hairs, the eyelashes, which help shade the 
eye, and shield it from dust (Exper. 113). 
The eyebrows form a protecting and shading ridge over 
the eyes; while the thick fringe of hairs, arranged some- 
what like the straw on a thatched roof, prevents.the sweat 
from rolling into the eyes as it trickles down the forehead. 
* This membrane covers the front part of the sclerotic, the whole of the 
visible portion, and, lining the walls of the tear-cluct, becomes continuous with 
the mucous membrane of the nose and throat, and, therefore, usually takes 
a part in a “ cold in the head.” It is, ordinarily, nearly white, with perhaps 
a few of the larger blood-vessels seen winding through it, but is very easily 
congested by local injury, or inflammation, particularly of the head, as in the 
case of the “blood-shot” eye. The characteristic yellow tinge of the eye in 
jaundice is due to the coloring-matter of bile deposited in the conjunctiva. 187 
THE SPECIAL SENSES. 
168. The Tears. — Nature provides a special fluid to 
protect the eye. This fluid is called the tears. The tear- 
apparatus consists of the gland for secreting tears, and 
the passages for draining them off. This gland pours 
out the tears over the surface of the eye, moistening it 
by the winking of the lids, and making its movements 
easy. The tears are now taken up, and carried off, by 
two fine tubes, one in the upper and one in the lower lid, 
which unite, and form the tear-duct, which leads into the 
nose. The ordinary flow of tears is thus drained off. 
Local irritation or mental emotion may excite an exces- 
sive flow, which the canals cannot carry off. The tears 
then overflow, and run down the cheeks. This is called 
crying, or weeping. Nature kindly greases the edges of 
the eyelids, to prevent, to a certain extent, the overflow 
of tears (Exper. 102). 
169. Color-blindness. — Color-blindness is the inability 
to tell certain colors. It is sometimes produced by sick- 
ness ; but generally it exists at birth, and is often heredi- 
tary.* This defect of sight is quite common. Out of the 
many thousands that have been examined, it is found that 
four or five per cent are color-blind. A person may be 
color-blind, and not know it until the defect is accidentally 
revealed. It is a matter of the utmost practical impor- 
tance to those employed on railroads, vessels, and other 
places where colored signals are used. Some are only 
partially color-blind, while others are wholly so. The 
most common form of color-blindness is that in which one 
fails to distinguish red. Women are rarely color-blind. 
170. Near-sight and Far-sight. — All eyes are not per- 
* Some years ago a physician gave a history of color-blindness which had 
existed in five generations of his own family. 188 
OUR BODIES. 
feet. Near-sight is a common defect of vision. In the 
healthy eye, the rays of light are brought to a focus on 
the retina. But in some eyes the image is blurred ; the 
outer coat, bulging backward, making the eyeball a little 
too long, thus bringing the rays of light to a focus be- 
fore they reach the retina. A person with such an eye 
is said to be “near-sighted.” It may exist at birth, and is 
very often hereditary. It is acquired by overstraining the 
eyes, in reading too fine print, by reading by a dim or 
imperfect light, and in many other ways. This defect is 
common with those who use their eyes much in reading, 
writing, and study. Sailors, farmers, and others who work 
outdoors, are rarely near-sighted. There has been found 
to be a steady increase of near-sightedness during the 
period of childhood and youth, especially among school- 
children. The statistics are so startling, that the subject 
is really one for the most serious consideration. Near- 
sightedness, in many cases, is a serious disease, which 
demands the most careful and skilful treatment by some 
good oculist. Teachers can do much to check the ill 
effects of this disease among their pupils. In far-sight the 
eyeball is too short, or the lens may be too flat. The rays 
of light are not brought to a focus. As a result, the image 
is blurred. The oculist can easily advise the proper kind 
of glasses to correct both of these defects of vision. 
171. Care of the Eyes. — The eye is an exceedingly 
delicate and sensitive little organ. It is an easy matter 
to get it out of order, and very tedious to restore it to 
health again. The eyes are often weak after certain sick- 
nesses. The utmost care must be taken of them during 
and after an attack of measles and scarlet fever. Read- 
ing poor and fine print is a severe strain on the eyes. THE SPECIAL SENSES. 
189 
The habit of reading the daily papers, with their blurred 
and indistinct type, in a car or carriage, is a severe strain 
on the eyes. We have to change the focus to suit the 
variation in the distance between the eyes and print caused 
by the constant jarring. It is a dangerous practice to read 
in bed at night, or while lying on a sofa or lounge in a 
darkened room. The outer muscles of the eyeball are put 
to a severe strain. The small type, poor paper, and press- 
work of the many cheap reprints of foreign literature, now 
so popular in this country, are very frequent causes of 
weak and diseased eyes. 
The direction in which the light comes, is an important 
matter. The worst direction of all is that from in front. 
The direct light should fall upon the print from above, and 
from the left side. The nearer an artificial light can come 
to a mellow daylight, the better. The light from a “ Ger- 
man student-lamp” is, perhaps, as safe and grateful as 
any. The flickering light from the ordinary “ fish-tail ” 
gas-burner is always bad. Its light should be regulated 
by shades and globes. The Argand burner, with its 
chimney and shade, gives an excellent but somewhat 
costly light. After reading steadily for some time, we 
should rest the eyes by looking at some distant object, 
even if only for a minute. A person should never read, 
write, sew, stitch, or otherwise use the eyes, when they 
tingle or smart, or the sight is dim or blurred. The eyes 
are weary, and need a rest. Using the eyes at dusk, or 
by artificial light in the early morning, is apt to lead to 
serious disorders of vision. The eyes should never be 
rubbed, or the fingers roughly poked into them at any 
time, and much less when they are irritated by getting 
some foreign substance into them. The sooner it is 190 
OUR BODIES. 
removed, the better. Rubbing the eye, or pulling the eye- 
lids, only makes a bad matter worse. When the eyes 
smart after going to bed, or tingle, and are “bloodshot ” 
on getting up the next morning, it is safe to conclude 
that they have been overtasked, and need rest. It is not 
a wise economy to tamper with one’s eyes when they are 
ailing. Better to do nothing than do the wrong thing. 
If a few days of rest do not give any relief, a good oculist 
should at once be consulted. 
Collateral Reading. Burnett’s Hearing, and How io Keep it; Harlan’s 
Eyesight, and How to Care for it, “ American Health Primers ; ” Carter’s Eyesight, 
Good and Bad. 
TEST QUESTIONS FOR REVIEW. 
1. What is meant by the term sensation ? Illustrate. 
2. What is the real centre of sensation ? Illustrate. 
3. What are the three organisms necessary to receive sensation? 
4. Give several examples to show this. 
5. Name and define the five special senses. 
6. What is meant by the “ muscular sense ” ? 
7. Tell how the skin acts as an organ of touch. 
8. What parts of the body are most sensitive to touch ? 
9. Does the sense of touch become more sensitive by practice ? 
10. Describe the tongue as the principal organ of taste. 
11. Where is the sense of smell located? 
12. How are we able to detect an odor? 
13. What are the uses of the sense of smell? 
14. What is the sense of hearing? 
15. Explain in a general way how sound travels through the air. 
16. Describe the outer ear. THE SPECIAL SENSES. 
191 
17. What is the middle ear? the inner ear? 
18. Explain just how we are able to hear. 
19. Give some practical hints about the care of the ear. 
20. What is meant by the sense of sight ? 
21. What is the eye? where located? 
22. Describe the coats of the eye. 
23. Explain in some detail the inner parts of the eye. 
24. Describe in full the mechanism of vision. 
25. What is meant by the term “focus ”? Illustrate. 
26. How are images brought to a focus on the retina ? 
27. Show how the eye is moved by muscles. 
28. What use are the eyelids ? eyebrows ? 
29. Tell what you know of the tears, tear-glands, and ducts. 
30. What is meant by color-blindness ? 
31. What is meant by near-sight and far-sight? 
32. Give some practical hints about the care of the eyes. 192 
OUR BODIES. 
CHAPTER XI, 
EXCRETION. 
172. Getting rid of Waste Matters. — Our bodies are 
never the same for a single moment. With every breath, 
and with every beat of the heart, they are ever changing. 
Wear and waste vie with growth and repair. We eat 
food to supply the bodily engine with fuel, and breathe in 
oxygen to feed the furnace-fire. With a steady burning, 
but without light, the engine produces not only motion 
and heat, but uses a part of its own energy to make its 
own repairs. Not this alone, but it even gets rid of 
its own soot, clinkers, and ashes, which would otherwise 
clog the machinery, and finally stop it. We have already 
learned that it is the ceaseless blood-current which carries 
fresh fuel, in the shape of the nutrient part of food, to 
the tissues ; and is a kind of a sewer-stream, that rids 
them of waste matters. The blood is ever being made rich 
by some things, and is ever getting rid of other things. 
The blood carries fuel to the tissues of the body. A slow 
burning takes place : the waste or ashes must be got rid of. 
173. Principal Waste Matters of the Body. — What 
are these waste matters ? If we take a piece of beef, dry 
it, and burn it, we shall find that it is changed into four 
things, —water, carbonic acid, ammonia, and ashes. Now, 
this slow burning of the tissues is really the same thing. EXCRETION. 
193 
Hence, in whatever way the body is burned, or oxidized, 
whether in a furnace, or while it is living, the end is 
always the same, — water, carbonic acid, a kind of ammonia 
called urea, and a small quantity of salts, or ashes. * 
Besides the water which comes from the burning of the 
hydrogen of our food, we are drinking a great deal. We 
need to keep the tissues continually moist, to help dissolve 
the food, and also to wash the body inside, and cleanse it 
of its useless matters and impurities. As we wash the 
surface of the body to keep it clean, so Nature is ever 
giving our tissues a bath, to wash away their impurities. 
The red blood-disks, as we know, are the tiny boats which 
carry the oxygen breathed in by the lungs along the blood- 
stream- to every tissue. The tissues contain carbon ; and, 
in some mysterious way, the oxygen unites with the car- 
bon, and carbonic acid is formed. The tissues, like the 
muscles and nerves, yield nitrogen. A partial decomposi- 
tion takes place ; and the nitrogen is filtered out of the 
body, through the kidneys, in the form of urea. It is a 
peculiar substance, something like ammonia, only more 
complex. Neither carbonic acid nor urea is fit to build 
tissue, or set free energy. 
174. The Organs of Excretion. —The process by which 
the body gets rid of its waste material is called excretion, 
meaning to separate from, or to sift out. The chief organs 
of excretion are the skin, the lungs, and the kidneys. The 
functions of all three of these organs are closely allied. 
* The body is made up of nitrogen, carbon, hydrogen, and oxygen, with 
sulphur, phosphorus, and some other elements. The nitrogen and hydrogen 
go to form ammonia; the hydrogen, with the oxygen of combustion, forms 
water; the carbon, carbonic acid; the phosphorus, sulphur, and other ele- 
ments, go to form the various salts of the body. 194 
OUR BODIES. 
They differ very much in appearance, but are built on the 
same principle. The blood, as it passes through the num- 
berless capillary channels in these organs, is purified by a 
sifting process. The products of excretion are, as it were, 
sifted from the blood, and finally removed from the body 
(chap. viii.). 
The lungs have also been described (chap. vii.). The 
duty of the lungs, as we have learned, is to excrete car- 
bonic acid, watery vapor, and a small portion of worn-out 
animal matter.* 
The structure of the skin has already been described. 
The main function of the skin, as we have seen, is to rid 
the body of water and other matters making up the sweat. 
175. The Kidneys. — These two important organs of 
excretion are of a brownish-red 
color, about four inches long, and 
two inches wide. They lie in the 
region of the loins, in front of the 
backbone, behind the intestines, one 
on each side, and are embedded in 
fat. A sheep’s kidney is a familiar 
sight in a market. Now, the kid- 
neys of man have the same shape, 
and look like those of a sheep, only 
a little longer. 
The name “kidney” is popularly 
given to a kind of bean, “the kidney 
bean,” because of its resemblance to the shape of a kidney. 
Fig. 52. — Longitudinal Section 
of Kidney: C, cortical sub- 
stance; M, medullary sub- 
stance: P, pelvis; U, ureter; 
RA, renal artery. 
* “ These three channels manage between them to keep the blood pure 
and fresh; working hard, and clearing off much, when much food or water 
is taken, or much work is done; and taking their ease, and working slow, 
mien little food is eaten, or when the body is at rest.” — M. Foster. EXCRETION. 
195 
A kidney is a bundle of long tubes, not so very unlike 
sweat-glands, all bound together into the kidney-shaped 
mass, whose appearance is familiar to us. The blood 
sweats urine into these glands, just as it exudes sweat 
into the sweat-glands. These glands unite into one com- 
mon tube, which carries the urine into the bladder, from 
which it is cast out of the body. The kidney purifies the 
blood by carrying off urea and other waste matters dis- 
solved in a large quantity of water.* 
The kidneys are very important organs in helping to 
keep the blood pure. They rid it of the nitrogenous por- 
tion of the waste products which it is always receiving. 
This is passed off for the most part in the urine. About 
three pints of fluid are daily discharged, on the average, 
through the kidneys, and a little over one ounce of urea, 
containing about two hundred and thirty grains of nitro- 
gen. Out of the body, the urea soon changes into carbonic 
acid and ammonia. 
The kidneys also serve to carry off various chemical 
and mineral substances that are either foreign to the body, 
or are present in the blood in too large a proportion. 
Thus, if we should drink a glass of salt water, the kidneys 
would rid the body of the excess of salt. If the kidneys 
are inactive, or fail to excrete the nitrogenous waste 
matters, the work of many other organs is seriously im- 
paired. The blood is poisoned, and death may result, from 
the powerful poisons left in the body (Exper. 114). 
* The whole of this excretion is called the urine. It is in reality water, 
holding in solution urea and several other salts. The urine is constantly 
being secreted by the kidney. It is carried to the bladder by a tube, the 
bladder serving as a reservoir. It collects in the bladder until that organ 
is nearly full, when it is emptied by contraction of its walls, aided by the 
abdominal muscles. 196 
OUR BODIES. 
176. The Health of the Kidneys. — The kidneys are 
very busy organs. Their health is a matter of prime im- 
portance to every human life. We have already become 
familiar with the hygiene of two great organs of excretion, 
— the skin and the lungs. These three sets of organs, 
then, working together in harmony, like three gangs of 
men doing some difficult work, keep the bodily machinery 
from getting clogged and choked with waste matters. If 
the balance of healthy life is to be maintained, these three 
great vital processes, or functions, must be carried on or 
regulated in strict harmony with each other. Thus, if the 
free action of the skin is interrupted, the kidneys have 
extra work to do. They make every effort to do the addi- 
tional work that is thrown upon them; but, sooner or 
later, they fail under the burden, and become diseased. 
Again, a person may overstrain the kidneys by drinking 
any fluid in excessive amount. This is especially true of 
those who drink enormous quantities of strong beer. This, 
in time, results in disease of these organs. In certain dis- 
eases, often due to alcoholic excess, the precious albumen 
is drained off from the blood through the kidneys. 
Like the liver, the kidneys are often singled out by well- 
meaning people as a favorite seat of imaginary disease. 
If a person gets cold, strains the deep muscles of the 
back, or is otherwise crippled, he is too apt to speak of 
the “crick” in the back as a “trouble with my kidneys.” 
The truth of the matter is, that the most serious and 
insidious diseases of these organs are rarely accompanied 
with pain. Hence the popular use of all kinds of nos- 
trums, shrewdly prepared to increase the flow of water, 
and called a “sure cure” for all kidney ailments, rarely 
does any good. Nine times out of ten, all such aches and EXCRETION. 
197 
pains in the back are clue to a severe cold, muscular 
cramps, or a bad strain. 
177. Effect of Alcohol upon the Kidneys. — The kid- 
neys are quick to feel the effects of alcohol. They 
become diseased in various ways, and often to a fatal 
extent, by alcoholic excess. Indeed, so powerful is the 
alcoholic poison on the vital action and structure of the 
kidneys, that physicians who are best fitted to judge, say 
that at least three-fourths of the instances of kidney dis- 
ease are due to alcoholic excess, and to this cause alone. 
In the first place, alcohol excites the kidneys to overaction 
by a chronic dilatation of the blood-vessels, thus irritating 
the delicate excreting cells of these organs. Again, it is 
known that hindering the changes of tissue-waste prevents 
the proper reduction into urea. Now, it is generally ad- 
mitted, that alcohol in excess does, in some measure, hinder 
the proper changes in the tissue-waste. Hence a large 
part passes out in a less soluble and more irritating form. 
Either from this cause, or from repeated congestion and 
irritation, alcohol leads at last to wide-spread disease of 
these vital organs in a large number of cases. The struc- 
ture of the kidneys may be so changed from alcoholic 
excess, that urea is not properly excreted ; and albumen 
is drained off instead. This may give rise to that pecul- 
iarly insidious and fatal disease known as “ Bright’s 
disease.” * It is now generally admitted, that the exces- 
* “ The relation to Bright’s disease is not so clearly made out as is 
assumed by some writers, though I must confess to myself sharing the popu- 
lar belief that alcohol is one among its most important causes.”—Robert 
T. Edes, M.D. 
“ Whether alcohol or cold be the sharper blade of the shears so apt to 
cut short life’s thread by Bright’s disease, I care not greatly, inasmuch as it 
cannot be questioned that both of them have that tendency.” — Chambers’s 
Diet in Health. 198 
oUK bodies. 
sive drinking of alcoholic liquors is a' frequent cause of 
this dreaded disease. 
The structure of the kidney is so changed, that there is 
no thoroughfare for the natural amount of urea. Thus, 
the ordinary safety-valve is shut off. The albumen, so 
essential to healthy blood, is filtered off through the dis- 
eased organ ; and the waste matters — the ashes — gee into 
the blood, and poison it. 
Collateral Reading. Foster’s Physiology, “ Science Primer Edition,” sect, 
viii., “ How the Blood gets rid of Waste Matters; ” also sect. i. of Introduction to Dr 
Tracy’s supplementary chapter on “ Hygiene,” in the same work. 
TEST QUESTIONS FOR REVIEW. 
1. Why is it necessary to get rid of waste matters of the body ? 
2. How would you compare the body to an engine in this matter of 
getting rid of waste material? 
3. Describe the principal waste matters of the “body. 
4. What are the three great organs of excretion ? 
5. How are their functions related one to the other? 
6. Describe the kidneys. 
7. What are their functions? 
8. What is the effect of alcohol upon the kidneys ? THE THROAT AND VOICE. 
199 
CHAPTER XII. 
THE THROAT AND VOICE. 
178. The Throat. — The throat is the common passage 
through which food goes to the stomach, and air to the 
lungs. It is shut in and protected by the muscles and 
bones of the neck. Both the outside of the neck and its 
interior, or the throat, are exposed to sudden and fre- 
quent changes of the weather, which oftentimes lead to 
diseases of the throat and the lungs. We have already 
learned something of the food and air passages in other 
sections (66, ioo). The only way to get a proper idea of 
the throat, is to look into a friend’s mouth. First let the 
person hold his mouth wide open, facing a good light. Hold 
the tongue down with the handle of a spoon. We are 
already familiar with the hard palate, soft palate, uvula, and 
tonsils (Exper. 39). Now, on looking directly past these 
organs, we see the middle portion of the pharynx, which 
is common to the two highways by which air and food are 
taken into the inside of the body. Look sharp at the top, 
and we see the air-passage which leads to the nose. The 
air-tract at the top has two outlets, the mouth and the 
nose. Now, if we pull the tongue forcibly forward, a lit- 
tle, curved ridge is sometimes seen behind it. This is the 
epiglottis, which, as we already know, is the trap-door which 
shuts down, like the lid of a box, over the top of the down- OUR bodies. 
200 
ward air-passage, or windpipe. The part of the throat 
directly opposite the line of vision, is the back wall of the 
pharynx, which, as the gullet, or food-passage continues 
downward. The pharynx. runs up to the base of the 
skull behind, and ends in a kind of vaulted roof,* shaped 
something like a crooked forefinger, or the top of an 
old-fashioned chaise (Fig. 22). All parts of this irregular- 
shaped region, known as the throat, are covered with a 
lining-membrane which secretes a fluid to keep them 
moist and comfortable. 
179. Care of the Throat. — Exposed as it is to un- 
healthy and unwholesome air, irritating dusts of the street 
and workshop, it is not strange that the delicate lining 
of the throat becomes inflamed. The result is a trouble 
which is popularly called “sore throat.” Almost every 
one has been at times troubled more or less with this 
ailment. The most frequent cause of throat-disease is 
the direct action of cold upon the heated body, espe- 
cially during profuse sweating. Breathing air laden with 
tobacco-smoke is apt to bring on sore throat. The habit 
of inhaling or swallowing tobacco-smoke, or breathing it 
through the nose, is hurtful to the throat, and often leads 
to disease. Eating the food hot, and then gulping down 
a deal of ice-water to cool the parts, is another source of 
sore throat. We may overstrain the muscles of the throat 
in loud talking, shouting, or by reading aloud too much. 
All classes of persons who strain the voice, or misuse 
it, often suffer from a severe kind of sore throat, popularly 
called “clergyman’s sore throat.” 
Persons subject to throat-disease should take great pains 
* This part of the throat, with the nasal passages, is subject to chronic 
inflammation, popularly known as “catarrh.” THE THROAT AND VOICE. 
201 
to wear proper underclothing. Daily baths are excellent 
tonics to the skin, and thus serve indirectly to harden 
one liable to throat ailments to ordinary changes in the 
weather. Muffling the neck in scarfs, furs, and wraps is 
not a good plan, — it only increases the liability to catch 
cold, — except, perhaps, during the coldest weather, or 
during unusual exposure to cold. 
180. The Organ of Speech. — As we have been told 
in a preceding section (ioo), the box- 
like top of the windpipe is called the 
larynx, meaning “top of the wind- 
pipe.” It is composed mainly of car- 
tilage. The sides of this box are 
made of two flat pieces of cartilage 
shaped like a shield, called the thyroid 
cartilage. The edges unite in front, 
and project to form “Adam’s apple,” 
which is easily felt, and is plainly to 
be seen on most lean people, espe- 
cially spare men (Fig. 53). This car- 
tilage shelters the delicate and mova- 
ble structure within, and shields it 
from injury without. The epiglottis 
is attached to the inner and upper 
part of this cartilage. Just below 
the thyroid is a ring-shaped cartilage 
called the cricoid. It is broad behind, quite narrow in 
front, much like a seal-ring, whence its name. This is 
easily detected under the skin, a little below the Adam’s 
apple. Two slender, ladle-shaped cartilages (called the 
arytenoid) are placed on the top of the back part of the 
cricoid. They work with a ball-and-socket joint, and have 
Fig. 53. — A Front View of the 
Exterior of the Cartilages of 
the Larynx: i, Upper Ring 
of the Windpipe; 2, Cricoid, 
or Ring-like Cartilage, the 
Base of the Laiynx; 3, Thy- 
roid, or Shield-like Cartilage 
(the figure 3 is on the Adam’s 
apple) ; 4, Epiglottis; M, a 
Membrane uniting the Cri- 
coid and the Thyroid Carti- 
lages. 202 
OUR BODIES. 
tiny muscles which regulate their movements with the 
utmost accuracy and regularity. From each arytenoid 
cartilage a band of elastic tissue passes forward, and is 
tied to the inner and front part of the thyroid cartilage 
towards its lower edge. These two bands, called the vocai 
cords, are narrow strips of firm, fibrous material, with a 
chink-like opening called the glottis, meaning the “mouth- 
piece of a flute.” This is the real organ 
of voice. All the air which goes out or 
into the lungs must go through the 
glottis. Muscles and cartilages act to 
tighten or loosen these cords. As the 
air is forced through the glottis, these 
bands are set into vibration, and thus 
sound is produced. When the cords 
are tightly stretched, and near together, 
they vibrate more rapidly, and send out 
a high tone : but when they are less 
tense, and wider apart, their vibrations 
are less rapid ; and a relatively low tone 
is the result. During ordinary breath- 
ing, the vocal cords are widely separated 
(Exper. 80). 
181. The Voice. — If the air be 
driven out of the lungs by an act of 
expiration, when the cords are in a state of tension, they 
vibrate, and produce the sound called the voice (Fig. 55). 
The different musical sounds produced in singing depend 
upon the varying degree of tension of the vocal cords. 
The compass of the voice depends upon the extent to 
which the variations can take place. A practised singer 
can at will give the requisite tension for the production 
of any particular note. 
Fig. 54. — Interior View of 
Right half of the Larynx: 
1, Upper Ring of the 
Windpipe; 22, Cricoid 
Cartilage; 3, Thyroid 
Cartilage; 4, Epiglottis; 
5, Vocal Band (Vocal 
Cord); 6, Arytenoid 
Cartilage; 7, Ventricu- 
lar Band (so-called False 
Vocal Cord). THE THRO A T AND VOICE. 
203 
The quality of a voice depends upon the structure of 
the larynx. In women and chil- 
dren*' the larynx is smaller, and the 
vocal cords shorter, than in men : 
consequently their voices have a 
higher pitch. The longer the cords, 
and the larger the larynx, the deeper 
the voice. 
Voice may exist without speech, 
as in many animals. Speech is the 
voice modified by the throat, teeth, 
palate, nose, tongue, and lips. In whispering, the sounds 
are produced by the vibration of the lips (Expers. 115, 116, 117). 
Fig. 55. — Image of the Larynx 
in Phonation: 33, Thyroid 
Cartilage; 4, Epiglottis; 5 5, 
Vocal Bands; 7 7, Ventricular 
Bands. 
Collateral Reading. Cohen’s The Throat and the Voice, “American 
Health Primers.” 
TEST QUESTIONS FOR REVIEW 
1. What is the throat ? 
2. How is it exposed to disease ? 
3. In what way can you get an idea of the throat? 
4. What parts of the throat can you see by looking into a friend’s 
mouth ? Explain in full. 
5. Describe the pharynx. 
6. Give some hints about the care of the throat. 
7. Describe the organ of speech. 
8. What are the vocal cords? Describe them. 
9. What is meant by the voice ? 
10. Upon what does the compass of the voice depend? 
11. What regulates the quality of the voice? , 
* About the age of fourteen, the vocal organs begin to enlarge rapidly. 
It causes a “ change of voice,” as it is commonly called, and is most marked 
in boys. The voices of children are very much alike in both sexes. 204 
OUR BODIES. 
REVIEW ANALYSIS: 
STIMULANTS AND NARCOTICS. 
1. Muscles. 
(Chap. iii. p. 48.) 
1. Effect of Alcohol on the Muscles (49).* 
1. Artificial Drinks (55). 
2. Tea, Coffee, and Cocoa (56). 
3. Effect of drinking Tea and Coffee (57). 
4. Alcohol described (58). 
5. Principal Drinks that contain Alcohol (59) 
6. Alcohol as a Food (60). 
7. Alcohol and Work (61). 
2. Food and Drink. 
(Chap. iv. p. 57.) 
1. Indigestion due to Alcohol (79). 
2. Effect of Alcohol on the Stomach-Digestion (80). 
3. Effect of Alcohol on the Liver (81). 
3. Digestion. 
(Chap. v. p. 87.) 
4. The Blood and its 
Circulation. 
(Chap. vi. p. 105.) 
1. Effect of Alcohol on the Circulation (96). 
2. How Alcohol gets into the Blood (97). 
3. Effect of Alcohol upon the Heart (98). 
5. Breathing. 
(Chap. vii. p. 122.) 
1. Effect of Alcohol upon the Lungs (109). 
2. Alcohol and the Bodily Heat (110). 
1. General Remarks on Stimulants and Narcotics (138). 
2. General Effect of Alcohol on the Nervous System (139). 
3. Alcoholic Excess and the Nervous System (140). 
4. Final Result of Alcoholic Excess (141). 
5. Inherited Craving for Alcohol (142). 
6. Tobacco and its Moderate Use (143). 
7. Excessive Use of Tobacco (144). 
8. Effect of Tobacco upon Young People (145). 
9. Opium (146). 
10. Practical Points about Opium (147). 
11. Chloral (148). 
12. Other Narcotics (149). 
6. The Nervous Sys- 
tem. 
(Chap. ix. p. 157.) 
* The figures in full-face type, in the parentheses, refer to the numbers of the sections in the 
preceding chapters of this book. SIMPLE MATTE PS OE EVERY-DAY HEALTH. 
205 
CHAPTER XIII. 
SIMPLE MATTERS OF EVERY-DAY HEALTH. —WHAT 
TO DO, AND HOW TO DO IT. 
182. What may be done?—Emergencies and acci- 
dents of all kinds are likely to happen at any moment. A 
friend may cut his leg or foot with a scythe or knife ; a 
child may accidentally swallow some laudanum, or push 
a bean into his nose or ear; a teamster is brought in with 
his ears frost-bitten ; a small boy falls into the river, and 
is brought out apparently drowned ; some one of our own 
family may be taken suddenly sick with some contagious 
disease, or may be suffocated with coal-gas. All these, 
and many other things of a like nature, are likely to call 
for a cool head, a steady hand, and some practical knowl- 
edge of what is to be done. These homely details of 
every-day health are easily mastered. It is simply the 
practical application of what we have studied thus far 
about our bodies. The dry facts of anatomy and physiology 
become tenfold more attractive and instructive to us when 
we thus learn to apply what we have studied to the simple 
matters of daily health. 
183. The Proper Use of Alcohol. — In thfe hands of a 
good physician, alcohol, like many other powerful aggnts, 
may prove a valuable drug. In cases of extreme weak- 
ness and bodily peril, undoubtedly alcohol, either alone or 
combined with other things, as milk, ammonia, etc., has 206 
OUR BODIES. 
helped to bridge over critical moments of disease when 
other agents would not be tolerated. Upon the doctor 
rests the responsibility of giving alcohol, as well as such 
drugs as aconite, arsenic, strychnia, opium, belladonna, and 
other poisons. It is well to remember that good physi- 
cians, as a rule, are slow to prescribe, or even to use, the 
various forms of alcohol in their professional labors. 
Alcohol is the basis of most liniments, and,fas such, is 
a useful agent. People are much inclined to use alcohol 
and rum in family use for all kinds of outward applications. 
No doubt, very cold or very hot water would do just as 
well in most cases. The indiscriminate use of some form 
of alcoholic liquor for every little ache or pain that occurs 
in the family, cannot be too severely condemned. Alco- 
holic mixtures must be used with the greatest caution, 
especially if there is any danger of stimulating the alco- 
holic appetite. We must use our common sense, and act 
honestly and consistently in this matter of using alcohol 
as in every other act of life. Black coffee, strong tea, 
hot water, cold water, hot milk, cayenne pepper, and am- 
monia water, in most emergencies, are strong remedies 
enough to use “till the doctor comes.” 
184. Frost-bite. — The ears, toes, nQse, and fingers are 
occasionally frozen or frost-bitten. No warm air, warm 
water, or fire is to be allowed near the frozen parts until 
the natural temperature is nearly restored. Great care 
must always be taken in the after-treatment, lest serious 
results should follow. Rub the affected part gently with 
snow or snow-water in a cold room. The circulation 
should be restored very slowly. Hot milk with cayenne 
pepper, and hot, strong coffee, should be freely given as 
stimulants (Exper. 118). SIMPLE MATTERS OF EVERY-DAY HEALTH. 
207 
185. Poultices, how to make them, and when to use 
them. — There are many occasions when the right kind 
of a poultice, made in the right way, and applied to the 
right spot, will give a great deal of relief from sudden and 
severe pains in the chest, abdomen, and elsewhere. The 
materials are so handy, the relief afforded so great, and 
the risk of doing harm so little, that even a child should 
know how to make a poultice, or put on a hot, outward 
application. Foremost amongst these household remedies 
is mustard. To make a "mustard paste,” as it is called, 
mix one or two tablespoonfuls of mustard and the same of 
fine flour with enough water to make the mixture an even 
paste. Spread it neatly with a table-knife on a piece of 
old linen, or even cotton cloth, of the required size. Cover 
the face of the paste with a thin piece of old muslin oi- 
lmen. Now apply the plaster with the face down. Some 
skins are easily blistered with mustard, hence it must be 
watched. About twenty minutes is long enough to keep 
it on. If the skin smarts badly, and is quite red, the paste 
should be removed. A mustard blister is painful, and hard 
to heal. It can be treated by covering it with strips of 
linen soaked in sweet-oil or vaseline. Do not put mustard 
paste on children : their skin is easily blistered with it. 
A thicker paste, or a poultice proper, can be made out 
of flaxseed, oatmeal, rye-meal, ground slippery elm, and 
bread. A poultice to be of any good, and to hold its heat, 
should be from half an inch to an inch thick. The way to 
make a good poultice is short and simple. Stir the meal 
slowly into a bowl of boiling water, just as the old-fash- 
ioned “ hasty-pudding ” is made, until a thin and smooth 
dough is formed. Fold a piece of old linen of the right 
size in the middle ; spread the dough evenly on one-half 208 
OUR BODIES, 
of the cloth, and cover it with the other. It is always 
better to cover the face of any poultice with a bit of old 
muslin if it is at hand. The secret of using a poultice is to 
apply it hot, and keep it so by frequent changes. Keep 
the poultice mixture hot on the stove, use duplicate cloths, 
and have a fresh, hot poultice to exchange in an instant 
for the cold one. Never let a poultice get cold and 
clammy : it will do more harm than good. Flannel wrung 
out in hot water, and cloths heated dry, and applied to 
painful places, are called fomentations. Simply dip the 
flannel, folded several times into the desired shape, into 
boiling water ; put it into a towel to protect the hands, 
and wring it out well. Apply it hot as possible, cover 
it carefully with larger pieces of flannel (oiled silk is the 
best of all), and use duplicate pieces to make the changes 
rapidly. These outward applications are useful to relieve 
sudden cramps and pains in the abdomen and chest, due 
to severe colds, injuries, sprains, etc. A “crick” or 
“stitch” in the side or back is quite common from over- 
straining certain muscles, and catching cold. A swollen 
face, due to an ulcerated tooth or neuralgia; flying pains 
in various parts of the body; a colicky pain in the abdo- 
men; boils and other sores tending to “point,” and very 
painful, — are a few of the many ailments for which poul- 
tices and outward applications will give a temporary relief 
from suffering (Exper. 119). 
ACCIDENTS AND EMERGENCIES 
186. Fainting. — Fainting is too familiar a sight to need 
much comment. Very little treatment is necessary. A 
fainting person should be laid out flat at once ; give plenty 
of fresh air; and dash cold water, if necessary, on the SIMPLE MATTE PS OP EVERY-DAY HEALTH. 
209 
head and neck. Loosen all tight clothing. It is well 
enough to hold smelling-salts to the nose, to excite the 
nerves of sensation (Exper. 120), 
187. Epileptic Fits, Convulsions of Children, etc.— 
Sufferers from “fits ” are more or less common. There is 
a peculiar cry, a loss of consciousness, a moment of rigidity, 
and violent convulsions come on : there is foaming at the 
mouth, the eyes are rolled up, and the tongue or lips are 
often bitten. Such a sufferer should be treated much the 
same as for fainting-fits. See to it that the person does 
not injure himself; crowd a corner of a folded handker- 
chief between the teeth, to prevent biting of the lips or 
tongue. Persons who are subject to such fits should not 
go out alone very much, and never into crowded or excited 
gatherings of any kind. Children occasionally will eat 
some indigestible substance, and suddenly be taken with 
fits. Give an emetic at once, and an enema of warm 
soap-suds. Put the child’s feet and legs into a bath of hot 
mustard-water for fifteen minutes. Children sometimes 
have fits during teething : then a hot bath is generally 
sufficient. 
188. Asphyxia, or Suffocation. — When for any reason 
the proper supply of oxygen is cut off, the tissues rapidly 
load up with carbonic acid. The blood turns dark, and 
cannot circulate. The healthy red or pink look of the lips 
and finger-nails becomes a dusky purple. The person is 
suffering from a lack of oxygen ; that is, from asphyxia, 
or suffocation, meaning “absence of pulse.” The first 
and essential thing to do is to give fresh air. Remove the 
person to the open air, loosen all tight clothing, dash on 
cold water, give stimulants, and, if necessary, use artificial 
respiration, as stated in the next section on drowning (189). 210 
OUR BODIES. 
The chief dangers from poisoning by noxious gases come 
from the fumes of burning coal in the furnace, stove, or 
range; from “blowing out ” gas, turning it clown, and hav- 
ing it blown out by a draught; from the foul air often found 
in old wells ; from the fumes of charcoal and the foul air 
of mines. 
189. Apparent Drowning. — 1'our things have happened 
to a person nearly dead from drowning. First, he is uncon- 
scious, because he has not had enough oxygen. Second, 
he has sucked water into the air-passages, and it must be 
removed. Third, he is cold, and needs warmth. Fourth, 
his blood is so full of carbonic acid, that the circulation 
is at the lowest ebb. What must be done ? Remove all 
tight clothing from the neck, chest, and waist. Sweep 
the forefinger, covered with a handkerchief or towel, 
round through the mouth, to free it from froth and mucus. 
Turn the body on the face, raising it a little, with the 
hands under the hips, to allow any water to run out from 
the air-passages. Take only a moment for this. Lay the 
person flat upon the back, with a folded coat, or pad of 
any kind, to keep the shoulders raised a little. Remove 
all the wet, clinging clothing that is convenient. If in a 
room or sheltered place, strip the body, and wrap it in 
blankets, overcoats, etc. If at hand, use bottles of hot 
water, hot flats, or hot sand round the limbs and feet. 
Watch the tongue : it generally tends to slip back, and to 
shut off the air from the glottis. Wrap a coarse towel 
round the tip, and keep it well pulled forward. 
The main thing to do is to keep up artificial respiration 
until the natural breathing comes, or all hope is lost. 
This is the simplest way to do it: The person lies on 
the back ; let some one kneel behind the head. Grasp SIMPLE MATTERS OE EVERY-DAY HEALTH. 
211 
both arms near the elbows, and sweep them upward above 
the head until the} nearly touch. Make a firm pull for a 
moment. This tends to fill the lungs with air by drawing 
the ribs up, and making the chest-cavity larger. Now, 
return the arms to the sides of the body until they press 
hard against the ribs. This tends to force out the air. 
This makes artificially a complete act of respiration. Re- 
peat this act about fifteen times every minute. All this 
may be kept up for hours. The first sign of recovery is 
often seen in the slight pinkish tinge of the lips or finger- 
nails. Because the pulse cannot be felt at the wrist is of 
little account as a sign of death. Life may be present 
when only the most experienced ear can detect the faintest 
heart-beat. When a person can breathe, even a little, he 
can swallow. Give then brandy or whiskey diluted some- 
what, or even a few drops often of the raw liquor. Put 
smelling-salts or hartshorn to the nose, and give a little 
ammonia and water if it is at hand. Meanwhile do not 
fail to keep up artificial warmth in the most vigorous 
fashion. Do not move a person who is just beginning 
to breathe again, from one place to another for some time, 
except when forced to do so from cold, or any pressing 
necessity. Above all things, do all that you do in right 
good earnest, and not in a spasmodic, half-hearted sort of 
way (Exper. 121). 
190. Sunstroke or Heatstroke. — This severe trouble is 
caused by an unnatural elevation of the bodily tempera- 
ture by exposure to the direct rays of the sun, or from the 
extreme heat of close and confined rooms, as in the cook- 
rooms and laundries of hotel basements, from overheated 
workshops, etc. The worst cases of “sunstroke” often 
happen in places where the sun’s rays never penetrate. 212 
OUR BODIES. 
There is sudden loss of consciousness, with deep, labored 
breathing, an intense burning heat of the skin, and a 
marked absence of sweat. The main thing is to lower the 
temperature. Strip off the clothing; apply chopped ice, 
wrapped in flannel, to the head. Rub ice over the chest, 
and place pieces under the armpits and at the sides. If 
there is no ice, use sheets or cloths wet with cold water. 
The body may be stripped, and sprinkled with ice-water 
from a common watering-pot. If the skin is cold, moist, 
or clammy, the trouble is due to heat-exhaustion. Give 
plenty of fresh air, but apply no cold to the body. Apply 
heat, and give stimulants. Remember that sunstroke or 
heatstroke is a dangerous matter. It may be followed by 
serious and permanent results. Persons who have once 
suffered in this way should carefully avoid any risk in the 
future. 
How to carry an Injured Person.—“If injured persons have to be 
moved from one place to another, it is worth while to know how to do it 
with the greatest ease and safety to them. If a door or shutter or settee is at 
hand, any of these will make a good litter, with a blanket or shawls or coats 
for pillows. In lifting a person upon a stretcher, it should be laid with 
its foot at his head, so that both are in the same straight line. Then one or 
two persons should stand on each side of him, and, raising him from the 
ground, slip him upon the stretcher. This can be done smoothly and gently; 
whereas, if a stretcher is laid alongside of an injured person, some of those 
who lift him will have to step backwards over it, and in doing so are very 
apt to stumble. If a limb is crushed or broken, it may be laid upon a pillow, 
with bandages tied round the whole, so as to keep it from slipping about. 
Where an injured person can walk, he can get much help by putting his arms 
over the shoulders and round the necks of two others. In case of an injury 
where walking is impossible, and lying down is not absolutelv necessary, an 
injured person may be seated on a chair, and carried; or he may sit upon a 
board or fence-rail, the ends of which are carried by two men, around whose 
necks he should place his arms, so as to steady himself; or two men may 
carry him seated on their interlocked hands, in the way known to children as 
“ Ladv to London.” To do this, each of two persons, standing face to face, SIMPLE MATTE PS OF EVERY-DAY HEALTH. 
213 
should grasp his right fore-arm with his left hand (its back uppermost), then 
he should grasp his companion’s free left fore-arm with his own free right 
hand (also with its back uppermost). W hen no litter can be gotten, the 
body may be supported by a man on each side, with their arms placed behind 
his chest and under his hips. In carrying an injured person upon a litter, or 
what serves for one, the bearers ought not to keep step; but, when they are 
not using a litter, they should keep step.” — Dulles’s Accidents and Emer- 
gencies. (Exper. 122.) 
191. Burns or Scalds. — Burns or scalds are dangerous 
in proportion to their extent and depth. A child may 
have one of his fingers burned off with less danger to life 
than an extensive scald of his back. After severe burns 
or scalds, remove the clothing with the greatest care. Do 
not pull, but carefully cut and coax, the clothes away from 
the burned places, taking some time for it. Save the skin 
unbroken if possible, taking care not to break the blisters. 
The secret of treatment is to avoid chafing, and to keep 
out the air. If the burn is slight, put on pads of soft linen 
soaked in a strong solution of baking-soda and water, one 
heaping tablespoonful to a cupful of water. It may be put 
on dry, and kept well covered with cotton-wool or band- 
ages. “ Carron oil ” is one of the best applications. It is 
simply half linseed-oil and half lime-water, shaken together. 
Soak strips of old linen in this, and gently apply. Simple 
cold water is better than flour, cotton-batting, and other 
things which are apt to stick, and make an after-examina- 
tion very painful. A deep or extensive burn or scald 
should always have good medical attendance (Exper. 123). 
192. Foreign Bodies in the Throat. — Bits of food and 
other small objects sometimes get lodged in the throat, 
and are easily got out by the forefinger, by sharp slaps 
on the back, or thrown out by vomiting. If it is a sliver 
from a tooth-pick, match, or fish-bone, it is no easy mat- 214 
OUR BODIES. 
ter to remove it; for it generally sticks into the lining of 
the passage. Holding a child up by the heels, with the 
head hanging down, and giving a few vigorous shakings, 
will often dislodge a foreign body when simpler means 
fail. If the object has actually passed into the windpipe, 
and followed by sudden fits of spasmodic coughing, with 
a dusky hue to the face and fingers, there is great danger 
of life. Surgical help must be called without delay. 
If a foreign body, like coins, pencils, keys, fruit-stones, 
etc., is swallowed, it is not wise to give physic. Let the 
bowels alone, and give plenty of hard-boiled eggs, cheese, 
and butter-crackers, so that the substance may be passed 
off in the natural way, in a bulky stool. 
193. Foreign Bodies in the Nose. — Children are apt 
to push marbles, beans, peas, fruit-stones, buttons, and 
other small objects, into the nose. Sometimes we can get 
the child to help by blowing the nose hard. At other 
times, a sharp blow between the shoulders will cause the 
substance to fall out. Do not waste time, — especially if 
it is a pea or bean, which is apt to swell with the warmth 
and moisture, — but call in medical help at once if you do 
not meet with success. 
194. Foreign Bodies in the Ear. — It is a much more 
delicate matter to get foreign bodies out of the ear than 
from the nose. The simplest thing is to syringe in a 
little warm water, which will often wash out the substance. 
If live insects get into the ear, drop in a little sweet-oil, 
salt and water, or even molasses. If the tip of the ear 
is pulled up gently, the liquid will flow in more readily. 
If a light is held close to the outside ear, the insect may 
be coaxed to crawl out towards the outer opening of the 
ear, being attracted by the bright flame. SIMPLE MATTERS OE EVERY-DAY HEALTH. 
215 
195. Foreign Bodies in the Eye. — Cinders, particles 
of dust, and other small substances, often get into the eye, 
and cause much pain. Do not rub the eye, however much 
you may feel like it. It will only make bad matters worse. 
Often the copious flow of tears will wash the substance 
away. It is sometimes seen, and removed simply by the 
twisted corner of a handkerchief carefully used. If it is 
not removed, or even found, in this way, the upper lid 
must be turned back. This is the way to do it : Seize 
the lashes between the thumb and forefinger, and draw the 
edge of the lid away from the eyeball. Now, telling the 
patient to look down, press a slender lead-pencil or pen- 
holder against the lid, parallel to and above the edge, 
and then pull the edge up, and turn it over the pencil by 
means of the lashes. The eye is now easily examined, 
and usually the foreign body is easily seen and removed. 
Do not increase the trouble by “poking” at the eye after 
you fail, but get at once skilled help. After the substance 
has been removed, keep on cloths frequently wet in cold 
water, for one day or more. If lime gets into the eye, use 
large quantities of vinegar or lemon-juice and water, one 
teaspoonful to a teacupful of water (Exper. 124). 
196. Bleeding. Hemorrhage. — Injuries to the Blood- 
vessels. — It is very important to know the difference 
between bleeding from an artery and that from a vein. If 
an artery bleeds, the blood spurts in a stream, or leaps in 
jets, comes very rapidly, and is of a bright scarlet color. 
If a vein bleeds, the blood slowly oozes out, or flows in a 
steady stream, and is of a dark and purple color. Bleed- 
ing from an artery is a dangerous matter in proportion to 
the size of the vessel, and life itself may be speedily lost ; 
while hemorrhage from the veins is rarely a serious injury, 216 
OUR BODIES. 
and generally stops of itself, aided, if need be, by hot water, 
deep pressure, some form of iron styptic, or even strong 
alum-water. When an artery is bleeding, always remem- 
ber to make deep pressure between the wound and the 
heart. In all cases where common sense would teach us, 
send at once for the doctor. Meanwhile there is some- 
thing to do. Keep cool, remember the simplest facts of 
the anatomy we have just studied, and do not be afraid to 
act at once. A resolute grip in the right place with firm 
fingers will do well enough, until a twisted handkerchief, 
stout cord, shoe-string, or suspender is ready to take its 
place. If the artery is of some size, make a knot in what- 
ever is used, and bring the pressure of the knot to bear 
over the artery. If the flow of blood does not stop, 
change the pressure until the right spot is found. Some- 
times it will do to seize a handful of dry earth, and crowd 
it down into the bleeding wound with a firm pressure. 
Strips of an old handkerchief, underclothing, or cotton- 
wadding, might be stuffed into the wound, keeping up 
the pressure all the time. 
Let us try to keep in1 mind the principal places to 
apply pressure when arteries are injured and bleeding. If 
in the finger, grasp it with the thumb and forefinger, and 
pinch it firmly on each side : if in the hand, press on the 
bleeding spot, or press with the thumb just above, and in 
front of, the wrist. For injuries below the elbow, grasp the 
upper part of the arm with the hands, and squeeze hard. 
The main artery runs in the middle line of the bend of the 
elbow. Tie the knotted cord here, and bend the fore-arm 
so as to press hard against the knot. For the npper arm, 
press with the fingers against the bone on the inner side, 
and just on the edge of the swell of the biceps muscle. SIMPLE MATTE PS OE EVERY-DAY HEALTH. 
217 
Now we are ready for the knotted cord. Take a stout 
stick of wood, about a foot long, and twist the cord hard 
with it, bringing the knot firmly over the artery. For the 
foot or leg, pressure as before, in the hollow behind the 
knee, just above the calf of the leg. Bend the thigh 
towards the abdomen, and bring the leg up against the 
thigh, with the knot in the bend of the knee. A knife 
may glance, and cut the great femoral artery. Remember 
it runs deep in the inside of the thigh, but is exposed 
when it comes out of the body below the groin. Press in 
the hollow just below the groin, about two-thirds of the 
way from the hip-bone to the middle line of the body. 
Double the thigh against the abdomen, and bend the leg 
on to the thigh, with the knotted cord in position. 
Bleeding from the Stomach and Lungs. — Blood that comes 
from the lungs is bright red, frothy, or “soapy.” There 
is rarely much, it usually follows coughing, feels warm, 
and has a salty taste. Bleeding from the lungs is a grave 
symptom. Perfect rest and quiet must be insisted upon. 
Bits of ice should be eaten freely. Loosen the clothing, 
keep the shoulders well raised, and the body in a reclining 
position. 
Blood from the stomach is not frothy, has a sour taste, 
and is usually dark colored, looking some like coffee- 
grounds. It is larger in quantity, and apt to be mixed 
with food. Do the same as before, except keep the per- 
son flat on the back instead of in a reclining position. 
Bruises. Cut and Torn Wounds. — A bruise is a familiar 
sight. It is a wound of the soft tissues, caused by blows. 
It is more or less painful, followed by discoloration due to 
the escape of blood under the skin. A black eye, and a 
lip or finger hurt by a base-ball, are familiar examples of 218 
OUR BODIES. 
this sort of injury. Soak the injured part in ice-cold 
water cloths at first, and, after the pain is easier, soak the 
parts in water hot as can be borne. If the cuts are small, 
clean the parts, bring the edges together, and stick them 
with plaster. When wounds are made with ragged edges, 
such as those made by broken glass and splinters, more 
skill is called for. Every bit of foreign substance must be 
got rid of first. Wash the parts clean with warm water, 
bring the torn edges together, and hold them in place with 
strips of plaster. Do not cover such a hurt all over with 
plaster, but leave plenty of room for the escape of matter. 
Wounds made from toy-pistols, percussion-caps, and rusty 
nails, if neglected, often lead to serious results from blood- 
poisoning. Cloths wrung out in cold water may be 
enough, but often a hot flaxseed poultice is needed for 
several days. Keep such wounds perfectly clean (Expers. 
125, 126). 
CARE OF THE SICK-ROOM. 
197. Hints for the Sick-room. — The sick-room should 
be the lightest and most pleasant room in the house. 
Some one of the family may be taken sick in the attic, or 
some inconvenient room. If possible, and especially if 
there is a prospect of a long illness, at once g&t a more 
suitable room ready. Take away all extra carpets, uphol- 
stered furniture, heavy curtains, etc. A clean floor, with 
a few rugs to deaden the footsteps, is much better than a 
woollen carpet. Carpets, extra clothing, etc., only absorb 
the impurities, and help keep the room foul. Let the 
room be accessible to sunlight and fresh air. It is gen- 
erally best to shade the room somewhat in certain dis- 
eases, yet take the time to let in all the sunlight possible SIMPLE MATTERS OE El’ERY-DAY HEALTH. 
219 
consistent with comfort. Sunlight and fresh air are far 
more efficient helps than most drugs. Besides, they 
cost nothing but a little painstaking and common sense. 
Pains must be taken to protect the patient from any 
noise which may disturb him, such as the noise of pass- 
ing steam and horse cars, heavy teams, and playing- 
children. (jive the sick-room plenty of sweet, fresh air. 
With a little pains, any room may be supplied with pure 
air. If you cannot do any thing else, cover the sick per- 
son all over with extra bed-clothes, open the windows 
and doors, and fan out the bad air. Be sure and avoid 
draughts of cold air. Have a thermometer, and keep the 
temperature as the doctor directs. Do not allow a kero- 
sene-light, with its flame turned down, to burn through the 
night. A close room with such odor for a whole night 
is enough to make a well person sick. If there is no gas, 
either use the lamp as usual, and put it, carefully shaded, 
in an adjoining room, or, better still, use a sperm candle 
for a night-light. Keep a sick-room neat and trim. Re- 
move at once all offensive matters. Never allow such 
things to remain two minutes in the room. In many 
diseases, especially scarlet-fever, diphtheria, putrid throat, 
consumption, etc., use pieces of old linen instead of 
handkerchiefs, and burn them as soon as they are used. 
Carelessness or ignorance in this matter often spreads 
contagious disease. Change the clothes of the bed and 
of the patient cpiite often. Do not let such clothing be 
put away in a closet with others. Put them to soak at 
once in boiling water, with some disinfectant added if 
necessary. Do not make a great show of bottles of medi- 
cines, spoons, glasses, etc., carefully spread out on the 
bureau or table. Keep all such things, except such as are 220 
OUR BODIES. 
absolutely necessary, in an adjoining room. To a patient 
not used to sickness, a formidable array of drugs and sick- 
apparatus is apt to be discouraging. Some simple thing, 
like an orange, a tiny bouquet of favorite flowers, and one 
or two playthings, may take their place. Never get 
behind the door, in a corner, or in an adjoining room, and 
whisper. It will fret a well person, to say nothing of its 
hurtful effects upon a sufferer whose nerves may be sen- 
sitive to the faintest noise. Whatever must be said, say 
it openly and aloud. How often a sudden turn in bed, or 
a quick glance of inquiry, shows that whispering is doing 
harm ! If the patient is in his right mind, answer his 
questions plainly and squarely. It may not be best to 
tell all the truth, but nothing is gained trying to avoid 
a straightforward reply. Do not deceive sick people. 
Tell what is proper or safe to be told, promptly and 
plainly. If a physician is employed, carry out his orders 
to the very letter, just as long as he visits you. Make a 
note of h.is directions on a slip of paper. Make a brief 
record of exactly what you do, the precise time of giving 
medicines, etc. This should always be done in serious 
cases, and by night-watchers. Then there is no guess- 
work. You have the record before you in black and 
white. All such things are valuable helps to the doctor. 
Above all, let there be cool, wise heads, willing hands, 
loving hearts, and a deal of common sense on the part of 
the helpers in the sick-room ; and a thankful submission, 
and a reasonable patience to endure, in the sick person. 
198. Poisons in General. — Poisons of various kinds 
are quite generally used in the trades, and kept about the 
POISONS AND THEIR ANTIDOTES. SIMPLE MATTERS OF EVERY-DAY HEALTH. 
221 
house and premises as medicines, as disinfectants, for 
killing insects and animals, and for many other purposes. 
People are often careless about them, and leave them 
almost anywhere, wrapped in a piece of paper, or in some 
unlabelled bottle, even in the cupboard, or on a shelf about 
the shed or stable. Children either mistake them, or are 
urged by some playmate to swallow them. All of us 
are too apt to seize a bottle or package hastily, and, 
“before we think,” have swallowed a dose of some poison. 
The many fatal accidents due to drinking carbolic acid 
by mistake is a familiar example of how stupid or careless 
people may be. All poisons should always be put in bot- 
tles carefully labelled, and the word “POISON” should 
be plainly printed in large letters directly across the label. 
Fasten the cork firmly to the bottle by wire picture-cord, 
or common iron wire, twisted into a knot at the top. 
This wire would certainly prevent a person from mistak- 
ing, in the dark, carbolic acid, oxalic acid, etc., for some 
favorite medicine. Poisons should never be kept in the 
same place with medicines or other bottled preparations 
used in the household. Put them in some secure place, 
and under lock and key. Another very simple rule is, 
never to use the contents of any package or bottle unless 
we know exactly what it is. Do not guess at it, or take 
any chances, but destroy it at once. 
Poisons are often taken when medical help, especially 
in the*country, cannot be had at short notice. Poisons do 
their work rapidly. Something must be done, and that 
at once, and in earnest. The stomach must be emptied as 
speedily as possible. Make a quart of warm soapsuds. 
Force the sufferer to gulp it down, a cupful at a time. 
Run the finger “down the throat,” and hasten the vomit- 222 
OUR BODIES. 
ing. A good emetic is made by putting a heaping table- 
spoonful of ground mustard into a pint of water. Drink a 
cupful every ten minutes until vomiting is produced. Stir 
up a handful of powdered alum in a cupful of molasses, 
and swallow this, a tablespoonful every ten minutes. Be 
in right good earnest about it, and do not waste time to 
see if the poisoned person likes such heroic treatment. 
Vomiting will not do any harm, and the poison may destroy 
life in a few minutes. 
199. Different Kinds of Poisons. — For convenience, 
let us arrange the most common poisons into different 
classes. Some are acids, like the oil of vitriol; others are 
alkalies, like lye; some are irritant mineral poisons, like 
arsenic or sugar of lead; while others are vegetable poisons, 
like aconite and Jamestown weed. We can easily remem- 
ber the general plan of treatment for each special class of 
the more common poisons. 
200. Acid Poisons. — Sulphuric acid (oil of vitriol), nitric 
acid (aqna fort is), and muriatic acid (spirits of salt), are in 
common use in certain workshops, and occasionally used 
in the household. These are caustic mineral acids, that 
rapidly burn and destroy the living tissues. Give an 
alkali. Swallow large quantities of strong soapsuds, chalk, 
tooth-powder, soda or saleratus water, magnesia, or lime- 
water. Scrape off the whiting from the wall, or dig out 
a piece of plaster. Put them into large quantities of 
water, and swallow the mixture. Follow this treatment 
with some mild, soothing tea made of flaxseed or Irish 
moss. Oxalic acid is often mistaken for granulated sugar 
or Epsom salts. P'or an antidote, use chalk, whitewash, 
plaster, etc., as before. Carbolic acid in solution is very 
commonly used about the house. It is a highly danger- SIMPLE MATTE PS OE EVEPY-DAV HEALTH. 
223 
ous poison, and generally fatal. Provoke vomiting by 
giving large quantities of soapsuds and sweet-oil mixed 
together. P'ollow with large draughts of oil or milk. Give 
very large doses of Epsom salts. 
201. Alkaline Poisons. — The common alkalies taken 
as poisons are ammonia, or hartshorn, potash, and soda, 
usually dissolved, and often in the form of lye. Horse- 
liniments and other liniments generally contain ammonia, 
and are often taken by mistake. Alkalies burn the lining- 
membranes rapidly and severely. Give acids. Drink vine- 
gar freely. Lemon-juice may be used. Take large quan- 
tities of sweet-oil, linseed-oil, and castor-oil. 
202. Metallic Poisons. — Arsenic is a white, sweetish 
powder, used to kill rats. It is occasionally taken by mis- 
take. Paris green is a form of arsenic used by farmers. 
Arsenic is also found in ratsbane and fly-powder. Pro- 
voke vomiting at once. Take large quantities of milk, 
the whites of eggs, flour and water, or oil and lime-water. 
A good antidote for arsenic is dialyzed iron, which can 
be bought at any drug-store. It should be given freely 
in tablespoonful doses, followed by a strong solution of 
salt and water. In sugar of lead poisoning, provoke vomit- 
ing, and give Epsom salts. In copper poisoning by “blue 
vitriol” and “verdigris,” give milk or white of eggs, fol- 
lowed by flaxseed tea. Children sometimes eat the phos- 
phorus from matches. This poison acts slowly, and there 
is time enough to get medical help. Give plenty of mag- 
nesia, chalk, or whiting, but no oil. 
203. Narcotic Poisons. — The various forms of opium 
are often taken by mistake, or in an overdose. The nar- 
cotic effects of the following preparations are due to 
opium : Laudanum, paregoric, morphine, Dover’s powder, 224 
OUR BODIES. 
Godfrey’s cordial, McMunn’s elixir, most cholera-mixtures, 
and many of the so-called “soothing-sirups” and “drops” 
(sect. 147). Brisk emetics must be given until they act 
thoroughly. Give plenty of hot, strong coffee without 
milk or sugar. Keep the patient awake, and do not allow 
him to fall into a deep sleep. Dash cold water over the 
head and shoulders, and slap the skin briskly with wet 
towels or with a slipper. Medical help must be called at 
once. Among other narcotic poisons occasionally taken 
without a knowledge of their poisonous character, espe- 
cially by children, are aconite, hemlock, deadly nightshade, 
Jamestown weed, monkshood, and toadstools. Use essentially 
the same treatment as in opium-poisoning. 
204. Other Poisons. — Certain kinds of fish act some- 
times as poisons to certain people, such as eels, crabs, 
mussels, etc. Fresh pork and other fresh meats occasion- 
ally act as a mild poison. Canned goods of a cheap grade 
sometimes act in the same way. Induce vomiting with 
some brisk emetic, and afterwards give a dose of castor- 
oil. Alcoholic liquors are sometimes taken in a single 
poisonous dose. Give a brisk emetic, and stimulate with 
frequent doses of a mixture made of a teaspoonful or more 
of ammonia added to a glass of water. For the sting of 
hornets, wasps, bees, etc., apply a pad of cloth soaked in 
a solution of carbolic acid, ammonia, or spirits of camphor. 
Crowd the barrel of a watch-key deep down on the hurt, 
to remove the sting of the insect (Exper. 127). 
DISEASES THAT SPREAD, AND DISINFECTANTS. 
205. How the Air may be Poisoned. — We have 
learned in a preceding chapter (chap, vii.), that the air 
may be more or less poisoned by the products of respira- SIMPLE MATTERS OF EVERY-DAY HEALTH. 
225 
tion, and other useless or injurious matters thrown off 
from healthy human bodies. We have shown the baneful 
effects of long-continued exposure in an atmosphere laden 
with these impurities. Now, in like manner, the air may 
be poisoned at certain times and places by the products 
of respiration and bodily emanations of diseased persons. 
Thus, in certain diseases, called contagious, organic mat- 
ters are thrown off in some way from the persons of the 
sick, which tend to reproduce themselves in the bodies 
of other persons. Thus, such diseases as small-pox and 
scarlet-fever are examples of severe and contagious dis- 
eases ; while whooping-cough, measles, and mumps are 
contagious, but less harmful. 
Again, the air may be poisoned with the foul gases aris- 
ing from the rapidly decomposing contents of cesspools, 
sewers, and privy-vaults. This poisoned air is popularly 
called sewer-gas. The living particles, or “germs,” of 
such diseases as typhoid-fever and dysentery, are believed 
to be contained, or developed, in the discharges, both from 
the stomach and bowels of persons suffering from these 
diseases. Diphtheria and typhoid-fever are believed to be 
due, oftentimes, to the decomposition of the contents of 
cesspools and sewers. Finally, the air may be poisoned 
by the decomposition of organic matters in the ground, 
and drawn into the house in various ways. Thus, there 
seems to be a connection between malarial fever and bad 
drainage. Certain low, damp soils are especially produc- 
tive of consumption. 
206. Disinfection. —With our present knowledge, it is 
not possible to get rid of the germs of disease after they 
are once fastened in the body. We are able, however, 
to a certain extent, to destroy them after they leave the 226 
OUR BODIES. 
body through the emanations and excreta of diseased per- 
sons. This destruction of the poisons of infectious and 
contagious diseases is called disinfection, and the means 
used are called disinfectants. We must remember that dis- 
infection cannot compensate for the want of cleanliness, 
nor of ventilation. Those things which destroy bad smells 
are not necessarily disinfectants, and disinfectants do not 
necessarily have an odor. 
207. What Disinfectants to use. — It is our aim to 
speak only of those which can be relied upon, and can be 
easily bought in sufficient quantities, even in our smaller 
villages, at little cost. There are many kinds of patented 
disinfectants, bearing some high-sounding name, and sold 
at a high price, which are of no more practical worth than 
plain brimstone and copperas, properly used. It is of the 
utmost importance, therefore, to know the comparative 
value of disinfectants, and the most effective methods of 
using them. It might be a serious mistake, to confound 
deodorisers — which simply kill the odor of disease — with 
disinfectants, which are believed to kill the germs of dis- 
ease ; and equally so to employ a powerful disinfectant in 
an ineffective way. Thus, carbolic acid, so much used 
in the sick-room, disinfects what it touches, and does not 
disinfect the air. It is a costly, uncertain preparation, but 
acts more effectively in combination with white vitriol and 
copperas. Simply to make outbuildings or a sick-room 
smell strong of carbolic acid, does not disinfect them. 
The following disinfectants are the most useful : — 
(i) Roll-sulphur or brimstone, for fumigation ; (2) Sul- 
phate of iron, or copperas,—also called green vitriol,— 
used in the proportion of one and one-half pound to the 
gallon of water, for sewers, cesspools, etc. ; (3) sulphate of SIMPLE MATTE PS OF EVERY-DAY HEALTH. 
227 
zinc, — called white vitriol,—and common salt, dissolving 
about four tablespoonfuls of the zinc, and two of the salt, 
to one gallon of water, for clothing, bed-linen, etc. 
208. H ow to use Disinfectants. — The following prac- 
tical suggestions for the use of disinfectants and the 
management of contagious diseases, were prepared for 
the National Board of Health by a committee represent- 
ing some of the ablest physicians and sanitarians in the 
country. 
1. In the Sick-room. — The most available agents are fresh air 
and cleanliness. The clothing, towels, bed-linen, etc., should at 
once, on removal from the patient, be placed in a pail or tub of 
the zinc solution, boiling-hot if possible, before removal from the 
room. 
All discharges should either be received in vessels containing 
copperas solution, or, when this is impracticable, should be imme- 
diately covered with copperas solution. All vessels used about 
the patient should be cleansed with the same solution. 
Unnecessary furniture, especially that which is stuffed, carpets 
and hangings, when possible, should be removed from the room 
at the outset: otherwise, they should remain for subsequent fumi- 
gation and treatment. 
2. Fumigation. — Fumigation with sulphur* is the only prac- 
ticable method for disinfecting the house. For this purpose, the 
rooms to be disinfected must be vacated. Heavy clothing, blank- 
ets, bedding, and other articles which cannot be treated with zinc 
solution, should be opened and exposed during fumigation, as 
* The burning of sulphur produces an irrespirable gas. The person who 
lights the sulphur, must, therefore, immediately leave the room, and, after the 
lapse of the proper time, must hold his breath as he enters the room to open 
the windows, and let out the gas. After fumigation, plastered walls should 
be whitewashed, the woodwork well scrubbed with carbolic soap, and painted 
portions repainted. 228 
OUR BODIES. 
directed below. Close the rooms as tightly as possible; place 
the sulphur in iron pans supported upon bricks; set it on fire by 
hot coals, or with the aid of a spoonful of alcohol, and allow the 
room to remain closed for twenty-four hours. For a room about 
ten feet square, at least two pounds of sulphur should be used; 
for larger rooms, proportionally increased quantities. 
3. Premises. — Cellars, yards, stables, gutters, privies, cesspools, 
water-closets, drains, sewers, etc., should be frequently and liber- 
ally treated with copperas solution. The copperas solution * is 
easily prepared by hanging a basket containing about sixty pounds 
of copperas in a barrel of water. 
4. Body and Bed Clothing, etc. — It is best to burn all articles 
which have been in contact with persons sick with contagious or 
infectious diseases. Articles too valuable to be destroyed should 
be treated as follows : — 
Cotton, linen, flannels, blankets, etc., should be treated with 
boiling-hot zinc solution, introducing piece by piece, securing 
thorough wetting, and boiling for at least half an hour. 
Heavy woollen clothing, silks, furs, stuffed bed-covers, beds, and 
other articles which cannot be treated with the zinc solution, should 
be hung in the room during fumigation, pockets being turned 
inside out, and the whole garment thoroughly exposed. After- 
ward they should be hung in the open air, beaten, and shaken. 
Pillows, beds, stuffed mattresses, upholstered furniture, etc., should 
be cut open, the contents spread out, and thoroughly fumigated.f 
* Put copperas in a pail of water in such quantity that some may con- 
stantly remain undissolved at the bottom. This makes a saturated solution. 
To every privy or water-closet, use about one pint of the solution night and 
morning. 
t The cutting open of stuffed articles may seem unnecessary, but it is not. 
The poison of contagious diseases clings to such stuffs with great tenacity 
for years, and must be destroyed before they are fit to be used again. 
“Contagious diseases are often caught at the funerals of those who have 
died of them; and the sanitary code of New-York City forbids a public 
funeral of any person who has died of small-pox, diphtheria, scarlet-fever, SIMPLE MATTERS OF EVERY-DAY HEALTH. 
229 
Carpets are best fumigated on the floor, but should afterward be 
removed to the open air, and thoroughly beaten (Exper. 128). 
Collateral Reading. Wilson’s Health and Healthy Homes; Richardson’s 
Long Life, and How to Reach it; Hartshorne’s Our Homes, “American Health 
Primers;” The House and its Surroundings, “ Health Primers;” Florence Night- 
ingale’s Notes on Nursing; Hope’s Till the Doctor comes; Dulles’s What to do 
frst in Emergencies; Turner’s Common Accidents and Diseases; Dixon’s What 
is to be Done: Ati Emergency Handbook; Tracy’s Handbook of Sanitary Informa- 
tion. 
TEST QUESTIONS FOR REVIEW. 
1. What is meant by “simple matters of every-day health”? 
2. Mention some things of the kind likely to happen. 
3. What real good may one do under such circumstances ? 
4. Give some points about the proper use of alcohol. 
5. What is frost-bite ? What would you do for it? 
6. Describe in detail the process of making poultices. 
7. When and how would you use them ? 
8. What would you do for fainting ? 
9. Fits, and what to do for them. 
10. What is meant by asphyxia? What is the treatment ? 
11. Describe in detail what is to be done in apparent drowning. 
12. What is sunstroke or heatstroke ? What would you do ? 
13. How would you carry an injured person ? 
14. What is the treatment for burns and scalds? 
15. What would you do for a foreign body in the throat? in the nose ? 
in the ear? in the eye? 
16. How would you know the difference between bleeding from an 
artery and bleeding from a vein ? 
17. On what general principles would you act to stop bleeding? 
yellow-fever, or Asiatic cholera. It is better to limit the attendance at such 
funerals to as few as possible” — Dr. Tracy’s Handbook of Sanitary In- 
formation. 230 
OUR BODIES. 
18. What would you do to stop bleeding from an artery? from a 
vein ? 
19. Can you tell the difference between blood coming from the lungs 
and that from the stomach ? If so, how ? 
20. What would you do for nose-bleed ? bruises ? cut and torn 
wounds ? 
21. Describe in detail how you would make a sick-room look neat and 
clean. 
22. How would you make a sick person more comfortable? 
23. Are persons likely to swallow poisons accidentally ? if so, when ? 
Mention some poisons often accidentally swallowed. 
24. What general treatment would you give for all poisons ? 
25. Mention the more common acid poisons. Their antidotes. 
26. Mention the alkaline poisons. Their antidotes. 
27. Mention some metallic poisons, and give antidotes. 
28. Mention some narcotic poisons. Their antidotes. 
29. What other things may act as poisons ? 
30. How may the air be poisoned ? 
31. What is meant by disinfection ? 
32. In what general way would you use disinfectants ? 
33. Mention the three most common disinfectants. 
34. Describe in detail how disinfectants should be used. PR A CTICA L EXPERIMENTS. 
231 
CHAPTER XIV. 
PRACTICAL EXPERIMENTS. 
209. Hints and Helps. — To get a thorough mastery 
of the elementary principles of anatomy, physiology, and 
hygiene, it is not enough simply to read and understand 
the text. Just as in chemistry and physics, a series of 
experiments are made, both by the teacher and the pupils, 
so should “physiology,” as it is popularly called, be illus- 
trated on the same general principles. Geology would 
certainly be a dry study without suitable specimens to 
illustrate the text-book. So, in the study of physiology, 
it is almost impossible to get an intelligent idea of the 
text, and that practical knowledge which is so desirable, 
without the aid of specimens and experiments. If we 
could have our choice in the matter, we should depend, for 
this part of our study, upon five sets of illustrations : — 
(1) The Skeleton and Manikin. 
(2) Charts, Diagrams, and Blackboard Exercises. 
(3) A systematic series of simple Experiments performed by the 
teacher and the pupils. 
(4) The systematic use of a suitable Microscope. 
(5) Experiments on the Person. 
By all means secure a skeleton and manikin, by loan or 
purchase, if possible. It is better to have some of the 
separate bones than none at all. The pupil should be 232 
OUR BODIES. 
trained to make and to copy sketches and diagrams in his 
note-book, and repeat them at stated intervals on the 
blackboard (see Figs. 18, 23, and 27). Such sketches 
may be somewhat rude, and there will be a great contrast 
in the work of different pupils ; but this is of little account. 
The teacher is advised to make for himself a series of 
diagrams, on a suitable scale for the blackboard, on sheets 
of manila paper, and have them bound, and hung up for 
easy reference in the schoolroom, somewhat in the same 
way that arithmetical or reading charts are now made. 
These sketches may be used to illustrate the text, and 
then copied from memory by the scholar. In addition to 
this, a set of physiological charts is very desirable, and 
should be secured if possible. 
By all means, depend upon a systematic series of rude, 
homely experiments, such as have been suggested in this 
chapter. Whatever we see with our own eyes, feel with 
our own fingers, and do with our own hands, in the shape 
of experiment or illustration, is of far more worth than 
merely reading the printed page. It is more like hard 
work, to be sure ; but laziness is a poor excuse in the study 
of physiology, or any other branch of science. The experi- 
ments in this book are simply suggestive. Do not merely 
copy them, but contrive others equally as good. In most 
schools, the cost is practically an important matter. Ac- 
cordingly, we have limited most of the experiments to 
such as can be done with cheap, homely, and simple appa- 
ratus, most of which can be picked up about the house, 
the market, and the village store. All these experiments 
should be done, both by the teacher and each member of 
the class. It is not enough to sit still, and see the teacher 
do them. Pupils should be encouraged to get together PR AC TIC A L EXPERIMENTS. 
233 
some of the material, and repeat some of the experiments 
on Saturday, or during a holiday. Clubs of three or four 
friends will find it both profitable and interesting to work 
together on a spare evening. If the school does not own 
a microscope, secure the loan of one, if possible, for a few 
weeks. No one ever forgets the first look at a drop of 
blood, or the circulation of blood in a frog’s foot, as re- 
vealed by the microscope. Glass slides ready for the 
microscope, and illustrating every part of the body, can 
be bought for a few cents each in any large city, and 
ordered from a printed catalogue. 
Finally, we have suggested many ways in which our 
own person, or that of a friend, may be utilized for the 
purpose of experiment and observation. The success of 
this part of the work will depend upon our skill, tact, and 
common sense. How much time and effort it is best to 
devote to this part of the study depend upon the age and 
capabilities of the class. Nothing can take their place in 
getting an accurate and thorough idea of the more essen- 
tial and practical points of anatomy. 
When specimens of bones, joints, dissections, etc., are 
carried into the schoolroom, the utmost pains must be 
taken to keep every thing neat and clean. Use large 
plates, platters, saucers, tissue-paper, with plenty of pins, 
needles, clean towels, and napkins. Cover every part 
except what it is necessary to show. Keep every thing 
covered until the proper time comes. Every little detail 
must be arranged before the recitation begins. If the fin- 
gers get soiled, remove all traces at once. Strict attention 
to all these little matters may make the difference between 
success and failure in these practical experiments. 234 
OUR BODIES. 
EXPERIMENTS ON THE BONES. 
[The figures in the parentheses refer to the sections of the text in which the 
subject of the experiment is referred to.] 
Experiment 1. To shozv the Gross Structure of Bone (12). — 
Saw lengthwise in two the bones of a sheep’s leg, or a calfs leg, 
including the knee-joint end. Save one-half. Boil, scrape, and 
carefully clean the other half. Note in the boiled half the com- 
pact and spongy parts, shaft, etc. Note on the other half, after 
trimming off the flesh, the pinkish-white look of the bone, the 
marrow and its tiny specks of blood, etc., — in other words, the 
difference between the fresh (live) bone, and an old, dry one 
(dead) easily found for the purpose. 
2. To show the Minute Structure of Bone (13).—Show the 
minute structure of bone by specimens of bone mounted on glass 
slides, and sold for microscopic use, costing only a few cents. 
If a microscope cannot be had, let each pupil draw a blackboard- 
sketch of the microscopic look of bone (Fig. 4). 
3. To show the Animal Part of Bone (l 1). — Get a chicken’s 
leg, or a sheep’s rib. Scrape and clean. Put one of the bones 
to soak into a mixture of four tablespoonfuls of muriatic acid 
to one pint of water. A wide-mouthed bottle is the best thing to 
hold it; next, an earthen bowl. Soak from five days to a week. 
It can now be bent, twisted, and even tied into a knot, showing 
that the earthy matter has been dissolved. The specimen can be 
kept for successive classes by keeping it in strong brine or dilute 
alcohol (half alcohol and half water.) 
4. To show the Earthy, or Mineral, Part of Bone (11). Get 
a large soup-bone from the table. Roast it on a bright, hot coal- 
fire for three hours. Do it carefully, and get a good specimen 
free from bone-black. The animal matter has now been burned 
out. The earthy part, a white, brittle mass, is now seen, showing PR A C TIC A L EXPERIMENTS. 
235 
every outline of the bone. Crumble parts of it between the fingers, 
and otherwise experiment upon it. 
Study of the Skeleton. — Let us now proceed to study the 
skeleton in two ways, — first, upon the mounted skeleton made 
for such use; second, by the examination of the skeleton or 
bones of our own person, or that of a friend. Every important 
part of the body can be mapped out with the fingers. Whether 
a skeleton or a chart* is used, this drill on the living body is 
essential to a practical knowledge of anatomy. Let a boy stand 
before the class ; and, as the teacher points out on his person the 
location of the various bones and bony landmarks of the body, 
each one of the class should stand, and do the same on his own 
person. The amusement of the thing will soon wear away, then 
settle down to hard drill. Do it thoroughly. Crowd the fingers 
deep down into the flesh, and trace the outline of the bones (the 
collar-bone and shoulder-blade, for example) very carefully. Do 
it all with neatness, tact, and a due regard for the feelings of all 
concerned. 
Use both the common and the scientific name for many of the 
bones. Drill thoroughly until all become perfectly familiar with 
the location of the most important and accessible bones and land- 
marks of the body. 
5. The Skeleton. —Its Study as a Whole (12). — Point out 
head, trunk, and limbs (8); long, short, flat, and round bones. 
Note how some bones protect certain parts, how others are built 
for use, beauty, and protection (30). Other such points will 
readily suggest themselves. Do the same on the person, so far as 
it is convenient. Use the chart for the same purpose. 
6. Parts of the Skeleton. — The Head (14). — Drill on the 
skeleton for the bones of the head ; the same on the person. 
Use the chart. 
7. Show how the bones of the skull are jointed; the sutures; 
* Good physiological charts for wall-use are almost indispensable. Use 
them every day if you have them. 236 
OUR BODIES. 
the plates of bones; the rough surfaces for the attachment of 
muscles; holes and notches for arteries and nerves. If nothing 
better can be had, get a part or the whole of some animal’s skull 
from the market, or even the fields (17). 
8. The Trunk. — Note the various bones as before (18). Trace 
and count each rib and vertebra. Make a special study of the 
spine.* 
9. The Upper Limbs (22).—The upper arm, fore-arm, hand. 
Experiment exactly the same as before. Every part can be care- 
fully traced on the person. 
10. The Lower Limbs (26). — Thigh, lower leg, foot. Ex- 
periment as before. 
11. Repair of the Bones (31) • — Ask some pupil who has broken 
his arm or collar-bone some time previously, to show how well the 
broken parts have united; the healing-cement at place of union, 
etc. 
12. Joints (32). — Get a part of a calf’s or sheep’s leg at the 
market. Open up the joint carefully, and carry it fresh and moist 
into the class for experiment. Note the sticky joint-oil; synovial 
fluid ; glistening surfaces of the 'ends of the bones; the gristle; 
cartilages; place where tendons, ligaments, and muscles are fas- 
tened. 
13. To show the Various Kinds of Joints (32). — Illustrate on 
the person the fixed and movable joints ; ball and socket; hinge ; 
pivot joints. Try the principal joints of the body, and see just 
how much and what motion they have. 
14. The Ligaments (33) . — In cutting open the joints, note the 
tough, firm, and gristly bands, which help hold the bones together. 
These are the ligaments. Try to tear or wrench them off from 
the bone, to see how firm and tough they are. Carefully dissect 
* Some parts of this experiment, as well as others, should be reserved for 
the privacy of one’s room. It is a most useful exercise to review the day’s 
work after undressing for the night. Be exact and precise, and do not mis- 
take fat and muscle for bone. PR A C TIC A L EXPERIMENTS. 
237 
one or two ligaments in whole or in part, leaving one end fastened 
to the bone, to illustrate their action. 
15. Bony Landmarks of the Body (p. 35). — Go over the 
skeleton or person, and locate with the fingers certain important 
“bony landmarks,” as the angle of the lower jaw; elbow-end 
of the ulna ; wrist-end of the radius ; highest point (acromion) of 
scapula; lower end of breast-bone ; upper end of tibia; lower 
end of fibula, etc. Other landmarks will suggest themselves. 
This will make an excellent review-exercise. 
EXPERIMENTS WITH THE MUSCLES. 
Experiment 16. To show the Gross Structure of Muscles (36)- 
— Get about half a pound of lean corned beef, a strip, with the 
fibres running all one way. Have it thoroughly boiled. Let it 
cool, and press it with the weight of several flat-irons. Put it on 
a firm board or table, and pick it in pieces with two darning- 
needles. Note the connective tissue, the larger muscular fibres. 
Pick with the needles until the fibres are too small to manage. 
Continue with a hand magnifying-glass. Examine the tiniest bit 
of fibre with the microscope. 
17. Again, boil a beef shin-bone for several hours. Note as 
before the coarse structure of the muscular fibres. Cut away the 
muscles, and dissect, to examine the fibrous tissue, fat tissue, liga- 
ments, and cartilage, or gristle (36). 
18. To show how Muscles contract and relax (37). — Get the 
lower part of a sheep’s leg at the market, with the foot or hoof 
still on; dissect with a sharp knife one or more muscles, leav- 
ing the insertion. Even if it is roughly done, it is no matter; 
for the fibres can be carefully smoothed into place with a knife- 
blade, stained with carmine ink, and made to look natural as 
life. Better make the dissection a week or so ahead of time, 
and let the parts harden a little in dilute alcohol. Then stain, 238 
OUR BODIES. 
and get it ready just at the time needed. The contraction and 
relaxation of muscles are thus roughly shown. 
19. Use your own biceps and triceps muscles (39) to show 
how muscles contract and relax, how they oppose each other in 
action. Repeat the same with other muscles, as the flexors and 
extensors of the fingers and toes, of the leg, etc. 
20. To show the Structure and Action of Tendons (40).— 
Take some of the material from the previous dissection, and 
examine the tendons. Get the leg of a fowl at the market, to 
show the tendons which make the toes bend. Get the butcher 
to save the hoof of an ox with one end of the tendon of Achilles 
still attached. Dissect it, and test its strength. 
21. Make a study of the tendons on your own person. 
Grasp the powerful tendons of the hip- muscles under the knee; 
of the lower leg (hamstrings) ; near the ankle; of the fore-arm at 
the wrist. Experiment with white braid tied on the tips of the 
fingers, and fastened on the arm, to show how the tendons of the 
arm work (40). T ie a ribbon tightly round the wrist to imitate 
the annular ligament, and note how differently the tendons act 
when they are under it or above it. 
22. To show how Muscles use the Bones as Levers (41).- 
First use a blackboard-pointer, broom-handle, or any other familiar 
object as a lever. Practise using it as a lever of the three different 
kinds, until the principles are familiar. Now illustrate on the 
person. Vary this experiment in many ways. Lift a book on 
the toes ; by the fingers ; on the back of the hand ; by the mouth 
by bending over to reach it; raise the book from a chair, and 
rest it on the head. Fasten a piece of braid to the neck of a 
bottle. Now tie one end to various parts of the body, as the 
middle of the arm ; the fore-arm ; the end of the fingers and foot, 
etc.; raising the bottle each time, and explaining exactly what 
kinds of levers are used, and also what kinds of muscles are used, 
— flexors or extensors. 
23. To illustrate the Action of Muscles in walking (42).— 
Walk three steps, explaining in some detail how it is done. PR A C TIC A L EXPERIMENTS. 
239 
24. To locate some Important Muscles (43). — Locate and 
describe them on the chart. Do the same, as far as it is pos- 
sible and convenient, on the person. Clutch tightly such muscles 
as the biceps, deltoid, great pectoral, muscles of the calf of the leg, 
etc. Run the lingers over the location of others, as the buccinator, 
latissimus dorsi, etc. Drill until the location and duty of the 
more important muscles become familiar. 
25. Muscular Landmarks (43) . — Use the chart, skeleton, 
and person, to locate the most important muscular landmarks, 
as the origin and insertion of the biceps; tendon of Achilles; 
annular ligament; edges of the great pectoral and biceps ; flexor 
cords of the forefinger, etc. This may be made an admirable 
drill-exercise. 
EXPERIMENTS ON FOOD AND DRINK. 
A series of most useful experiments may be made on the subject 
of food and drink. The common articles of diet greet us on every 
hand. It should be our object to understand the principles which 
underlie the matter of daily food. We should become familiar 
with the principal substances contained in the three great classes 
of foods. We can do this by exhibiting specimens, and by experi- 
ment. Specimens of the various cereals, starches, sugars, oil, etc., 
should be shown, which have been carefully collected, and kept 
for class-use in empty morphine or quinine bottles bought at the 
drug-store. Even small radish or pickle bottles are good enough. 
Each specimen should be neatly labelled with its exact name. 
Many interesting facts can be brought out about the practical use 
of these substances as foods, when we are able to touch, taste, 
smell, and see the substances themselves. 
Experiment 26. To show Albumen (52).—The albumens are 
all rich in one or more of the following organic substances : albu- 
men, casein, fibrine, gelatine, gluten, and legumen. Boil an egg 
hard. The white is albumen hardened by heat (see Exper. 28). 240 
OUR BODIES. 
27. To show Casein. — Pour some liquid rennet, vinegar, or a 
little weak acid, into some milk. A whitish substance (the curd) 
separates from it. This nitrogenous substance is casein, the chief 
constituent of cheese. 
28. To show Fibrine. — Take a piece of lean meat, and wash it 
thoroughly in water, squeezing and pressing it well in a lemon- 
squeezer. A whitish, stringy mass is obtained, which is the fibrine. 
The albumen is dissolved in the water. Boil the water after the 
meat has been washed. The heat coagulates the albumen. 
29. To show Gelatine. — Boil a bone a long time. Most of the 
animal matter will be dissolved. The substance thus dissolved is 
gelatine.* 
30. To show Gluten. — Put a handful of flour into a muslin 
bag, and squeeze it well in a basin of water. The water becomes 
milky; while a sticky, yellowish-white substance remains in the 
bag. This sticky substance is the gluten. Allow the water to 
stand, and the starch settles at the bottom in a white powder. 
31. To show Legumen. — Boil a few peas or beans in the pod, 
until they become a sticky, pulpy mass. This is the nitrogenous 
principle called legumen, and resembles the white of an egg and 
the gluten of flour. Nearly every kind of vegetable is rich in this 
flesh-forming material. 
32. To show the Starches (52). — Specimens of the more 
common kinds of foods rich in starch should be shown, and passed 
round the class in bottles. Potato, rice, sago, arrowroot, tapioca, 
corn-flour, etc., may be used for illustration. The presence of 
starch is easily proved. Boil a small quantity of flour, rice, bread, 
potato, or arrowroot in a little water, in a test-tube. Add a drop 
or two of the tincture of iodine, and the mixture will turn blue. 
33. To show the Sugars. — Cane-sugar is familiar as cooking 
and table sugar. Various specimens should be shown, including 
* You may have seen your mother boil calves’feet to make jelly for 
the sick-room. The familiar substances, glue and size, are simply gelatine 
obtained by boiling the hoofs, horns, skin, etc., of animals. PR A C PICA L EXPERIMENTS. 
241 
varieties of molasses, in two-ounce vials. To show grape-sugar, 
get some raisins, and pick out a handful of the little white grains. 
Get a cent’s worth of milk-sugar at the drug-store. 
In starch and sugar, the oxygen and hydrogen are combined in 
just the proportions necessary to form water. Sulphuric acid 
re-acts upon either starch or sugar to remove the oxygen and 
hydrogen ; and carbon, or charcoal, is left behipd. Hence, the 
name carbo-hydrates, or hydrates of carbon, is given to this class 
of substances. There are three groups, the sugars proper, the 
glucoses, and the starches and gums. In a rough way, we may 
speak of them as carbon dissolved in water. 
34. Take several wineglasses. Put some thin starch paste into 
the first, and several varieties of sugar into others. Pour in care- 
fully down the side of each glass a little sulphuric acid. The 
mixtures will turn black. The acid has precipitated the charcoal. 
Stir a little charcoal in another wineglass full of water, and pour in 
acid as before. It remains black : no change has taken place. 
35. By heat, starch is converted into a kind of sugar. This is 
called dextrine. This is a gummy substance, soluble in water, and 
is used on the back of postage-stamps. Touch the tip of the 
tongue to the back of a postage-stamp, and the sweet taste will be 
noticed. Dextrine is sold in the shops under the name of “British 
gum.” 
36. To show the Various Kinds of Fats and Oils (52).— 
Show specimens of fats that are solid at ordinary temperatures, 
such as beef-suet, mutton-suet, lard, and butter. Liquid fats are 
commonly called oils. The two principal kinds used as food are 
olive-oil and cod-liver oil. The first is obtained from the fruit of 
a tree, and the second from the livers of the cod and the haddock. 
37. Simple Experiments to show that Milk is a Model Food 
(54).—Milk is rightly called a compound food, since it is com- 
posed of at least five kinds of food-substances. Take some milk 
“ fresh from the cow,” and place it in a tall, narrow glass vessel, 
and allow it to stand for several hours. A quantity of cream rises 242 
OUR BODIES. 
to the top. Cream is the milk-fat. It is simply made up of tiny 
bags of fat, each of which has a covering of curd. By churning 
the cream about a short time, the covering is broken, and the little 
lumps of fat unite to form the yellow solid called butter. Now 
skim off the cream : what remains is called skim-milk. Add a tea- 
spoonful of vinegar, weak acid, or liquid rennet, to the skim-milk. 
Solid whitish lumps of curd will be seen separating from a watery 
fluid called whey (see Exper. 58). We have now divided the milk 
into three parts, cream, curd, and whey. Cream is the fat; curd 
is the casein, or nitrogenous part, which, when pressed and dried, is 
called cheese; and whey is milk-sugar and mineral matter dis- 
solved in water. 
These simple experiments show that milk contains flesh-forming, 
bone-making, and heat-giving materials, and that it contains these 
in the right proportions, especially for children. 
38. To show Water, the Minerals, and Appetizers (52).— 
Water is too familiar a food for experiment. If water could be 
easily obtained from some iron or sulphur springs, it would be inter- 
esting to compare the taste with specimens of hard and soft water 
from the neighborhood. The mineral matter left from Exper. 4 
shows the various kinds of lime and potash. An egg-shell is a 
familiar example of carbonate of lime. Various kinds of salt 
(forms of soda) can be got from any grocery-store. The white of 
an egg contains a little sulphur. Leave a silver spoon in it for a 
short time, and the sulphur will blacken it. 
Specimens of the most common appetizers should be shown 
(53), as vinegar, pepper, mustard, ginger, cloves, nutmegs, cinna- 
mon, allspice, etc.; also samples of substances from which bever- 
ages are made, such as tea, coffee, cocoa, and chocolate (56). 
Wide-mouthed ointment or pill bottles are useful for this purpose. 
Small bottles containing about one ounce each of the more 
common kinds of alcoholic liquors may be exhibited, to enable 
each pupil to become familiar with the look of rum, whiskey, gin, 
etc. A few simple experiments may be made with alcohol, to 
show that it is inflammable, that it has a pungent taste, etc. (59). PR A C TIC AI EXPERIMENTS. 
243 
EXPERIMENTS ON DIGESTION. 
Experiment 39. To show the Anatomy of Certain Organs, and 
Parts of Organs, of Digestion (63). — Have each pupil examine 
his own mouth, and also that of some friend. Note the lips, 
tongue, hard palate, soft palate, uvula, tonsils, and upper part of 
the gullet. Become familiar with each and every part. 
40. Tiie Teeth (64). — Get a specimen of each kind of tooth 
if possible. A dentist-friend will give you what you need. Use 
a very fine saw to saw a perfect molar in two lengthwise. If need 
be, crack the tooth open with a hammer. Note its structure in 
a general way, — its crown, body, cusps, roots, enamel, dentine, 
pulp-cavity, etc. 
41. Make a blackboard-sketch of a tooth on a large scale, 
using colored crayon to make plain the various parts of a tooth. 
42. To show the Difference of Teeth in Various Animals.— 
Get, if possible, specimens of teeth of the more familiar animals,* 
as the cat, dog, rat, squirrel, etc. Compare them with the speci- 
mens of human teeth. 
43. With the help of a mirror, let each pupil locate his own 
teeth. Note the incisors, eye-teeth, bicuspids, molars, and “wis- 
dom ” teeth if any. In the same way, note the teeth of some 
schoolmate. 
44. Locate as near as possible the position of each salivary 
gland. Press on the part of the cheek opposite the second small 
molar of the upper jaw, and notice the increased flow of saliva. 
The appearance of saliva is familiar (65). 
45. To show Location of Other Organs of Digestion (66). — 
Make a blackboard diagram, in the rough, of the organs of diges- 
tion, beginning at the cardiac end of the stomach, after having 
* No stress is laid in this book upon the subject of “comparative anat- 
omy.” Many valuable points can be made orally by the painstaking teacher. 
The subject is fully discussed in school text-books on physiology by Cutter and 
Dunglison. For reference, consult Mivart’s Lessons in Elementary Anatomy. 244 
OUR BODIES. 
studied the digestive organs on the chart (Fig. 27). Map out 
on the person in a very general way the location of the stomach, 
small intestines, and the colon, liver, pancreas, and spleen. The 
location of the stomach and liver is especially important. 
46. To show how the Walt of the Stomach looks (67) • — The 
wall of the pig’s stomach resembles the human stomach. Get from 
the market a piece of a pig’s stomach. Cut off bits of it, and 
examine it thoroughly. Scrape off the inner or mucous coat with 
the edge of a very sharp knife. Use a magnifying-glass ; find the 
openings of the gastric tubes. Pick with fine needles, and note 
the muscular coats. Contrast the pig’s stomach with that of a 
cow’s by examining a piece of tripe. 
47. To make the Saliva flow (65)- — Think of some favorite 
article of food (both at the time you are hungry and when you are 
not), and note the flow of saliva. Push a lead-pencil, or the finger, 
to and fro in the mouth several times, and note the flow of saliva. 
Chew an oyster-cracker, and note carefully how it is moistened 
with saliva. Stuff several crackers rapidly into the mouth, and 
note how difficult it is to swallow, or even chew; when there is 
little saliva. 
48. To shotv the Action of Saliva on Starch. — Chew slowly a 
piece of fresh bread.* Note how sweet it tastes after it is well wet 
with the saliva. Do the same with a mouthful of paste made of 
pure arrowroot (almost pure starch), made with boiling water, and 
allowed to cool. 
49. Take three test-tubes. Into test-tube No. 1, half full of 
cold water, add some half a dozen drops of the arrowroot paste ; 
now add one of Fehling’s Test-Tablets.f Mix thoroughly, and 
* Chew pieces of the brown crust of the bread. It is quite sweet, and 
readily dissolves; because, exposed to more heat than the rest of the loaf, the 
starch has been changed into dextrine before the bread left the oven. Hence, 
crust and toast are favorite articles of food, especially with old people. 
t These tablets have been used of late as a convenient method for physi- 
cians 4o test for sugar. It is simply an easy way to use the test usuallymacle 
with a solution of caustic potash and blue vitriol. PR A C TIC A L EXPERIMENTS. 
245 
boil over a spirit-lamp. There is no turbid brick-red deposit to 
show that there is sugar in the starch (arrowroot). 
50. Put several teaspoonfuls of saliva into test-tube No. 2. 
Dilute it with water. Add a test-tablet, mix thoroughly, and boil. 
There will be a violet color, but no brick-red deposit to show the 
presence of sugar in the saliva. 
51. Take test-tube No. 3, and put a few drops of the starch 
paste into a teaspoonful of saliva, and fill the test-tube half full of 
water. Put the mixture away for ten minutes in a warm place. 
Now add a test-tablet. Mix and boil. A turbid brick-red deposit 
will be thrown down, showing that sugar is present, due to the 
action of the saliva on starch. 
52. To show the Action of Gastric Juice on Albumen (67). — 
Take an ordinary four-ounce bottle with as wide a mouth as con- 
venient. Put into it the following : Pepsin in scales (Fairchild’s),* 
one grain, and four tablespoonfuls of luke-warm water. Make it 
acid with ten drops of strong muriatic acid. Add two teaspoon- 
fuls of finely minced egg-albumen.f Set the mixture in any con- 
venient place sufficiently warm, as in a basin of warm water, near 
the stove, or on the mantel near the warm smoke-pipe, to keep the 
contents of the bottle at about “ blood-heat.” J Shake every few 
minutes. As soon as the whole mixture becomes of a proper tem- 
* It is not at all necessary to go through the long process of getting 
pepsin from a pig’s stomach. Pure pepsin, obtained from the stomach of 
the pig, is now made by dealers for medical use; and the necessary amount 
can be bought of a good druggist for a few cents. Use only pure pepsin in 
the experiments. The student is advised to use Fairchild’s “Pepsin” and 
“ Extract of Pancreas.” 
t The albumen, or the white, of an egg, is taken as the type of albumen in 
a naturally pure state, and is well adapted to illustrate the peptonizing action 
of the gastric ferment. It should be first made ready as follows: Separate 
the white of a hard-boiled egg, and rub it through a coarse sieve, so as to 
divide it into small particles. 
J In these experiments on digestion, the temperature should never be 
below blood-heat, and never allowed abov# a point at which fluids can be easily 
borne by the mouth. 246 
OUR BODIES. 
perature, the pepsin will begin to act upon the albumen; and it 
may be seen to be gradually softened and digested. This dis- 
solved mass is now in a condition to soak through the 
moist lining of the stomach, and is known as “ peptone.” 
53. Repeat the same experiment, using half a teaspoonful of 
finely cut, cooked, and lean beefsteak or corned beef instead of the 
white of an egg. The meat will be more or less dissolved, or par- 
tially digested, in twenty-four hours. This experiment is only a 
crude way to show the action of gastric juice on meat-albumen. 
54. Get some freshly drawn blood. Whip it with twigs. Pull 
off the collected fibrine, and wash it carefully in clean water. Save 
this in dilute alcohol, and use it as a handy albumen for digestive 
experiments. Repeat as directed in Expers. 52 and 53. 
55. To show the Action of Bile on Fat (68). — Shake up a 
little sweet-oil and water. “ Oil and water will not mix,” as the 
saying goes. Get the butcher to bring you a small bottle of bile 
(ox-gall), or, better still, ask him to bring the gall-bladder itself. 
Cut it open, and bottle the contents. Shake up some oil with bile, 
and a creamy mixture called an “ emulsion ” results. 
56. To show the Action of Pancreatic Juice upon Oils or Fats 
(68). — Put two grains of Fairchild’s Extract of Pancreas into a 
four-ounce bottle. Add half a tablespoonful of warm water, and 
shake well for a few minutes; then add a tablespoonful of cod- 
liver oil; shake vigorously. A creamy, opaque mixture of the oil 
and water (called an “ emulsion ”) will result. This will gradually 
separate upon standing, the pancreatic extract settling in the layer 
of water at the bottom. It will again form an emulsion when 
shaken. 
57. To show the Action of Pancreatic Juice on Starch. — Make 
a smooth starch paste, just as the laundress does in starching her 
clothes. Put two tablespoonfuls of this paste into a goblet or 
tumbler, and, while still so warm as to just be borne by the mouth, 
stir into it two grains of the Extract of Pancreas. The starch 
paste will at once become thinner, and gradually changed into 
soluble starch, in a perfectly fluid solution. PR A C T/CA L EXPERIMENTS. 
247 
58. To show the Action of Pancreatic Juice upon the Albu- 
minous Ingredients (casein) of Milk. — Into a four-ounce bottle 
put two tablespoonfuls of cold water; add one grain of Fairchild’s 
Extract of Pancreas, and as much baking-soda as can be taken up 
on the point of a. penknife. Shake well, and add four table- 
spoonfuls of cold, fresh milk. Shake again. Now set the bottle 
into a basin of hot water (as hot as can bear the hand in), and 
let it stand for about forty-five minutes. While the milk is digest- 
ing, take a small quantity of milk in a goblet, and stir in ten drops 
or more of vinegar. A thick curd of casein will be seen (see 
Exper. 37). Upon applying the same test to the digested milk, no 
curd will be made. This is because the pancreatic ferment (called 
trypsin)* has digested the casein into “peptone,” which does not 
curd. This digested milk is therefore called “peptonized milk.”f 
59. Study of the Liver (68). — The whole of a liver is rather 
an awkward and bulky thing to handle; but it is a good plan to 
get a sheep’s liver, and devote a little time to its gross anatomy. 
Take pains to get the liver with the gall-bladder unbroken. Hav- 
ing once secured a fine specimen, it may be kept for future use in 
dilute alcohol. 
60. To illustrate the Principle of Absorption (69). — The 
manner in which absorbent vessels suck in juices may be illustrated 
in a general way as follows : Take a glass tube, and tie a piece of 
bladder, in the form of a small bag, at the end of it; pour some 
mucilage into it, and then plunge the end into a cup or glass con- 
taining water. In a few moments the mucilage in the tube will 
begin to rise, and the water in the glass will sink ; because, being 
* The active principle of the saliva which acts upon starch is often 
spoken of as ptyalin, in order to distinguish it from the starch-digesting prin- 
ciple of the pancreatic juice. Both have the same action upon starch. Ex- 
per. 57 will also illustrate the action of saliva. 
t Infants, especially those brought up on artificial foods, often suffer from 
ill digestion, “ summer complaint,” and other intestinal troubles during hot 
weather. Partially digested, or peptonized, milk is found to be of the great- 
est service at such times. 248 
OUR BODIES. 
more dense than the water, it draws it in through the bladder, and 
will continue to do so until they are equal. Again, if we put 
mucilage into the glass, and fill the tube with water, the water will 
fall in the tube until they become of the same thickness. It is on 
this principle that the absorbent vessels suck in liquids which are 
thinner than what they previously contained. 
EXPERIMENTS ON THE HEART AND THE 
CIRCULATION. 
Experiment 61. — Tie a string tightly round the finger, and 
prick the tip of it with a needle. The blood runs freely, is red 
and opaque. Put a drop of fresh blood on a sheet of clean white 
paper, and note that it looks yellowish (83). 
62. Put a drop of fresh blood on a clean white plate. Cover 
it with an inverted goblet or sauce-plate. Take off the cover in 
five minutes, and the drop has set into a jelly-like mass. Breathe 
into the goblet several times to moisten it, and replace it over the 
blood. Take it off in half an hour, and a little clot will be seen in 
the watery serum. 
63. To show the Blood-Clot (85). — Carry a clean, wide- 
mouthed bottle to the slaughter-house. A half-pound chloral 
bottle bought at any drug-store is the best. A clean horse-radish 
bottle will do. Fill it with fresh blood. Carry it home with great 
care, and let it stand over night. The next day the clot will be 
seen floating in the nearly colorless serum. 
64. To show the Fibrine of the Blood (85) • — Get a wide- 
necked bottle full of fresh blood. A pint or quart fruit-jar is the 
best for this purpose. Beat the blood vigorously for five minutes 
with some dry twigs, and hang them up to dry. Let the blood 
stand until the next day. Note that it has not clotted. Wash out 
the twigs thoroughly, and a stringy mass of elastic substance will 
be found hanging to them. This is the fibrine. Pit A C TIC A L EXPERIMENTS. 
249 
65. Take some of the serum saved from Exper. 63, and note 
that it does not coagulate of itself. Boil a little in a test-tube over 
a spirit-lamp, and the albumen will coagulate. 
66. To show that blood is really a mass of red bodies, floating 
in a fluid, which give it the red color. Fill a clean white-glass 
bottle two-thirds full of little red beads, and then fill the bottle 
full of water. At a short distance the bottle appears to be filled 
with a uniformly red liquid. 
67. To show the Blood Corpuscles (84). — A moderately 
powerful microscope is necessary to examine blood corpuscles. 
Let a small drop of blood (which may be readily obtained by 
pricking the finger with a sharp needle) be placed upon a clean 
slip of glass, and covered with a piece of thin glass, such as is 
ordinarily used for microscopic purposes. By this means, the 
blood is spread out into a film, and may be examined with the mi- 
croscope. At first the corpuscles will be seen as pale, disk-like 
bodies floating in a clear fluid. After a time they will be observed 
to stick to each other by their flattened faces, so as to form rows. 
The colorless corpuscles are to be seen among the red ones, but 
they are much less numerous. 
68. To show how Blood holds a Mineral Substance in Solu- 
tion. — Put an egg-shell, crushed fine, into a glass of water made 
acid by a teaspoonful of muriatic acid. After an hour or so the 
egg-shell will disappear, having been dissolved in the acid water. 
In like manner the blood holds various minerals in solution. 
69. To show the Sounds of the Heart (87, 94). — Locate 
the heart exactly. Note its beat. Borrow a stethoscope from 
some physician. Listen to the heart-beat of some friend. Note 
the sounds of your own heart in the same way. 
70. To find the Pulse (95). — With your right hand grasp the 
right wrist of a friend, pressing with three fingers over the radius. 
Press three fingers of your right hand over the radius in the left 
wrist, to feel your own pulse. With the aid of a watch, count the 
rate of your own pulse per minute; the same with a friend’s pulse. 250 
OUR BODIES. 
71. Dissection of a Sheep's Heart (94)- — Get a sheep’s heart 
with the lungs attached, as the position of the heart will be better 
understood. Let the lungs be laid upon a dish so that the heart 
is uppermost, with its apex turned towards you. 
The line of fat which extends from the upper and left side of 
the heart downwards and across towards the right side, indicates 
the division between the right and left ventricles. Examine the 
large vessels, and, by reference to the text (sects. 87-90) and 
illustrations (Figs. 29, 30), make quite certain which are the aorta, 
the pulmonary artery, the superior and inferior vefice cavce, and 
the pulmonary veins. Tie variously colored yarns to the vessels, 
so that they may be distinguished when separated from the sur- 
rounding parts. 
Having separated the heart from the lungs, cut out a portion of 
the wall of the right ve7itricle towards its lower part, so as to lay 
the cavity open. Gradually enlarge the opening until the chordce 
tendinece and the flaps of the tricuspid valve are seen. Continue 
to lay open the ventricle towards the pulmonary artery until the 
semilunar valves come into view. The pulmonary artery may now 
be opened from above, so as to display the upper surfaces of the 
semilunar valves. Remove part of the wall of the right auricle, 
and examine the right auriculo-ventricular opening. 
The heart may now be turned over, and the left ventricle laid 
open in a similar manner. Notice that the mitral valve has only 
two flaps. The form of the valves is better seen if they are placed 
under water, and allowed to float out. Observe that the walls of 
the left ventricle are much thicker than those of the right. Open 
the left auricle, and notice the entrance of the pulmonary veins, 
and the passage into the ventricle. 
The ventricular cavity should now be opened up as far as the 
aorta, and the semilunar valves examined. Cut open the aorta, 
and notice the form of the semilunar valves. 
72. To show the Circulation in a Frog's Foot. — In order to 
see the blood circulating in the membrane of a frog’s foot, it is PR A C TIC AI EXPERIMENTS. 
251 
necessary to firmly hold the frog. For this purpose obtain a piece 
of soft wood, about six inches long and three wide, and half an 
inch thick. At about two inches from one end of this, cut a hole 
three-quarters of an inch in diameter, and cover it with a piece 
of glass, which should be let into the wood, so as to be level with 
the surface. Then tie up the frog in a wet cloth, leaving one of the 
hind-legs outside. Next, fasten a piece of cotton to each of 
the two longest toes, but not too tightly, or the circulation will be 
stopped. Tie die frog upon the board in such a way that the foot 
will just come over the glass in the aperture. Pull carefully the 
pieces of cotton tied to the toes, so as to spread out the mem- 
brane between them over the glass. Fasten the threads by draw- 
ing them into notches cut in the sides of the board. The board 
should now be fixed by elastic bands, or by any other convenient 
means, upon the stage of the microscope, so as to bring the mem- 
brane of the foot under the object-glass. The flow of blood thus 
shown is indeed a wonderful sight, and never to be forgotten. 
The membrane should be occasionally moistened with water. 
EXPERIMENTS ON THE LUNGS AND BREATHING. 
Experiment 73. To locate the Lungs (101) . — Mark out the 
boundaries of the lungs by “sounding” them; that is, by percus- 
sion, as it is called. It simply means, to put one finger across 
the chest or back, and to give it a quick, sharp rap with another. 
Note where it sounds hollow; that is, is resonant. This experi- 
ment can be done only in a very crude way. 
74. Borrow a stethoscope, and listen to the respiration directly 
below the collar-bones. Note the difference in inspiration and 
expiration. 
75. Get a sheep’s lungs, with the windpipe attached, from a 
butcher or marketman. Ask for the heart and lungs all in one 
mass. Take pains to examine the specimen first, and pay only 
for a good one. Parts are apt to be hastily snipped or mangled. 252 
OUR BODIES. 
76. Examine the windpipe. Note the horseshoe-shaped rings 
of gristle in front, which serve to keep it open. 
77. Examine one bronchus, carefully dissecting away the lung- 
tissue with curved scissors. Follow along until small branches of 
the bronchial tubes are reached. Take time for the dissection, and 
save the specimen in dilute alcohol. Put pieces of the lung-tissue 
in a basin of water, and see if they float. 
78. To show how the Lung may be filled with Air (102).— 
Take the other lung, and tie a glass tube six inches long into its 
bronchus. Attach a piece of rubber to one end of the glass 
tube. Now blow up the lung, and then let it collapse several 
times. When distended, examine every part of it. 
79. To show the Diaphragm (102). — Dissect a rat or kitten, 
and cut out a section of the body large enough to show the dia- 
phragm and its attachments. The parts can be neatly held in 
place by pins and silk threads, and the whole kept in dilute 
alcohol. 
80. To show the Vocal Cords (100, 180). — Get a pig’s wind- 
pipe in perfect order from the butcher, to show the vocal cords. 
Once secured, it can be kept for an indefinite time in alcohol. 
81. To show that the Air we breathe out is warm. — Breathe 
on a thermometer for a few minutes. The mercury will rise 
rapidly. 
82. To show that it is moist. — Breathe on a mirror, or a knife- 
blade, or any polished, metallic surface. 
83. To show that the Air we breathe out contains Carbonic 
Acid. — Put a glass tube into a bottle of lime-water, and breathe 
out into it through the tube. The liquid will soon become cloudy, 
because the carbonic acid of the expired air throws down the lime 
held in solution (104). 
To show the Natural Temperature of the Body. — Borrow a 
physician’s thermometer, and take your own temperature, and 
that of several friends, by putting it under the tongue, closing the 
mouth tightly, and holding it there for five minutes (108). PRACTICAL EXPERIMENTS. 
253 
EXPERIMENTS ON THE SKIN. 
Experiment 84. To shozu the Gross Structure of the Skin 
(112, 113 ). — Examine your own skin in a general way. Stretch 
and pull it, to show how elastic it is. Get some idea of the scarf- 
skin by scraping off some with a sharp knife. Some one in the 
school is generally ready to exhibit a blister on the hands. Note 
any white scars, liver-spots, etc., on the skin. Examine the skin 
with much care, with the aid of a good magnifying-glass. Note 
the papillae on the palm of the hand. 
85. Hair and Nails (114, 115). — Pull a stout hair from the 
head, and examine it carefully with the magnifying-glass. Make a 
similar study of the finger-nails. 
86. The Sweat-glands (117). — Use a magnifying-glass to 
study the openings of the sweat-glands, especially on the palms 
of the hands. 
EXPERIMENTS ON THE NERVOUS SYSTEM. 
Experiment 87. To show the Brain and Spinal Cord. — Get a 
kitten or cat that has been doomed to die. Kill it by drowning, 
or by chloroform. It is a troublesome matter to dissect out the 
brain and spinal cord. The back of the animal to be dissected 
should be turned upwards, and the limbs should be securely 
fastened to the top of a small table. 
The skin is removed from the head by making a longitudinal 
incision in it, and then turning it back upon each side. The 
muscles upon the sides and back of the skull should next be 
cleared away. A hole may now be made in the top of the skull 
with the point of a pair of scissors, and the bone broken away 
piece by piece, with a pointed pair of nippers, until the upper sur- 
face and sides of the brain can be seen. In the cat, kitten, or 
rabbit, the cerebral hemispheres do not, as in man, cover the cere- 254 
OUR BODIES. 
bellum; and consequently the latter is seen when the brain is 
viewed from above. 
When the bone has been broken away so as fairly to expose the 
sides of the brain, the latter should be carefully raised by inserting 
the tips of the fingers under it on one side, and gently pulling. 
Several white cords will thus be seen passing from the under sur- 
face of the brain to the floor of the skull: these are the cranial 
nerves (129). 
To expose the spinal cord (130), the skin of the back must be 
removed, and the muscles cut away from each side of the backbone, 
as close to the bone as possible : then, beginning at the back of the 
skull, the spinal canal is to be laid open by cutting with the nippers 
the two sides of each vertebra. Care must be taken not to cut or 
tear the spinal cord, or the nerves passing off from it. When the 
spinal cord has thus been exposed, and the membranes which sur- 
round it made out, the spinal nerves (133) should be examined. 
The brain and spinal cord should now be removed, by carefully 
raising them, and cutting off the nerves by which they are attached. 
The specimen should now be neatly fastened to a thin strip of 
smooth pine-wood, firmly held in place with pins. The whole can 
be kept in alcohol and water. Great patience is necessary to 
make the dissection a success. 
88. To show the Brain. — A sheep’s or calf’s brain is to be pre- 
ferred, on account of its larger size. Get one fresh from the butcher. 
Pay him to dissect away the skin and muscles of the skull, under 
your direction, — to saw open the cranium in a circular direction. 
Take time, and remove the sawed top with great care, tearing 
away the dura mater from the bones. Now cut away this mem- 
brane enough so that the sides of the skull can be sawed and torn 
away, to allow us to lift out the brain, with proper dissection, in as 
perfect a state as need be. Put all the torn parts and membranes 
back into place. Put the whole aside to harden for three days in 
alcohol. Now it is ready for the study of its gross anatomy. Note 
the dura mater, the arachnoid lining it, and the pia mater closely PR A C PICA L EXPERIMENTS. 
255 
attached to the brain. Find the cerebrum, or big brain, the cere- 
bellum, or little brain, the medulla, and the stumps of the cranial 
nerves, especially the stumps of the optic nerves. The hardened 
brain should be first examined as a whole, and compared with the 
description given (125-129), or the pictures of the human brain 
(Figs. 41, 42, 43). 
89. Experiments on the Frog, to show Reflex Action (131).— 
The animal best suited for the study of reflex action is the frog; 
and, in order to be quite sure that the movements which take place 
in the following experiments do not depend upon the brain, the 
head should be completely severed from the body, and the space 
neatly filled with absorbent cotton. 
Let a frog treated in this manner be placed upon its abdomen, 
and the hind-limbs extended. At first, perhaps, it will remain per- 
fectly motionless, except that the heart will continue to beat. After 
a time, however, the shock produced by the operation will pass off, 
and the limbs will be drawn up towards the body. 
If the frog be now suspended by the neck, the limbs will hang 
down freely. Pinch the tip of one of the toes, and the limb will 
be suddenly drawn up to the body, and, after some time, gradually 
fall again. Scratch one side of the body with a needle. When 
this is done gently, only a slight movement of the muscles of the 
side will be observed. But, if the irritation is increased, the move- 
ments become more general, and at length the limbs will move. 
If, while the limbs are hanging down quietly, one of the toes be 
touched with dilute acid, the limb will be immediately drawn up. 
Pinch the skin upon the inside of the thigh, the legs will kick as 
if endeavoring to remove the object which is irritating it. Put a 
drop of vinegar or dilute acid upon one of the thighs, the leg 
will be quickly moved about as if to rub off the acid. If, how- 
ever, the leg be secured so that it cannot move, the leg of the 
opposite side will endeavor to rub off the acid (132). 
To show that all the above-mentioned reflex phenomena depend 
upon the integrity of the spinal cord, pass a stout pin down the 256 
OUR BODIES. 
spinal canal so as to destroy the spinal cord. It will then be 
found that reflex actions no longer take place.* 
90. Sensations are referred to the Ends of the Nerves. — Striking 
the elbow-end of the ulna against any thing hard (“ hitting the 
crazy-bone ”) where the ulna nerve is exposed, the little finger and 
the ring-finger will tingle, and become numb. 
91. Every Little Nerve is independent of any other. — Press 
two fingers closely together. Let the point of the finest needle be 
carried ever so lightly across from one finger to another, and we 
can easily tell just when the needle leaves one finger, and touches 
the other. 
92. One Part of the Body works for the Good of Another Part. 
— Tickle the inside of the nose with a feather. This does not 
interfere at all with the muscles of breathing; but they come to 
the help of the irritated part, and provoke a sneeze to clear and 
protect the nose. 
93. To paralyze a Nerve temporarily. — Throw one arm over 
the sharp edge of a chair-back, bringing the inner edge of the 
biceps directly over the edge of the chair. Press deep and hard 
for a few minutes. The deep pressure on the nerve of the arm 
will put the arm “ asleep,” causing numbness and tingling. The 
leg and foot often “ get asleep ” by deep pressure on the nerve of 
the thigh. 
EXPERIMENTS ON THE SPECIAL SENSES. 
Experiment 94. — Cross the middle finger over the forefinger, 
and shut the eyes. Hold a marble between the tips of the crossed 
fingers. There seems to be two marbles (152). 
* There are numerous illustrations of reflex action which take place 
in our daily living, and which may be simply stated in this connection 
without any special attempt to illustrate them by experiment. Many of 
them cannot well be shown in the schoolroom. Most of us have tried some 
such experiments, such as tickling the foot or nose of one sound asleep, 
more for sport than from any special interest in reflex action. PR A C TIC A L EXPERIMENTS. 
257 
95. Shut both eyes, and let a friend run the tips of the fingers 
first lightly over a hard, plane surface, then pressing hard, and then 
lightly again, and the surface will seem to be hollowed out. 
These two experiments show that we are easily misled, even by 
the sense of touch. It is mainly matter of habit and education. 
96. Put a drop of vinegar on a friend’s tongue, or your own. 
Notice how the papillae of the tongue start up (153). 
97. Rub different parts of the tongue with the pointed end of a 
piece of salt or gum-aloes, showing that the back of the tongue 
is most sensitive to salt and bitter substances. 
98. Repeat the same with some sweet or sour substances, to 
show that the edges of the tongue are the most sensitive to these 
things. 
99. Apply the points of a pair of compasses to various places 
on the surface of the body, to show the most sensitive spots. 
100. We often fail to distinguish between the sense of taste 
and that of smell. Chew some pure, roasted coffee, and it seems 
to have a distinct taste. Pinch the nose hard, and there is little 
taste. Coffee has a powerful odor, but only a feeble taste. The 
same is true of garlic, onions, and various spices (154). 
101. Light helps the sense of taste. Shut the eyes, and palata- 
ble foods taste insipid. Pinch the nose, close the eyes, and see 
how palatable a teaspoonful of cod-liver oil becomes. 
102. Gently turn the inner part of the lower eyelid downwards. 
Look in a mirror ; and the small “ lachrymal point,” or opening into 
the nasal duct, may be seen in your own eye (168). 
103. Close the eyelids, and press firmly on to the eyeball with 
two fingers. Note how firm and dense it is to what one might 
imagine (162). 
104. The Retina is easily tired. — With a hand-mirror reflect 
the sunlight on the white wall, and keep it fixed. Look steadily 
at it for a full minute, and then let it suddenly be removed. Its 
“ complementary ” color — a dark spot — will appear. Pin a round 
piece of bright red paper (large as a dinner-plate) to a white wall 258 
OUR BODIES. 
by a single pin. Fasten a long piece of thread to it, so it can be 
pulled down in a second. Gaze steadily at the red paper. Have 
it removed while looking at it intently, and a greenish spot takes 
its place. 
105. To illustrate the Action of the Crystalline Lens (164).— 
Hold a burning-glass in front of an open window in such a way 
that the image of some object outside will be brought to a focus 
upon a piece of paper. This miniature image will be upside 
down. 
106. The walls of the eyeball of a white rabbit are quite trans- 
parent. Hold a lighted candle before the cornea. An image of 
the candle will be seen reflected on the retina. 
107. To vibrate the drum-membrane and the little ear-bones, 
shut the mouth, and pinch the nose tightly. Try to force air 
through the nose. The air dilates the eustachian tube, and air is 
forced into the ear-drum. The distinct crackle, or clicking sound, 
is due to the movement of the ear-bones and membranes (157). 
108. The Retina is not sensitive where the Optic Nerve enters the 
Eyeball. — This is called the “blind spot.” Put two ink-bottles 
about two feet apart, on a table covered over with white paper. 
Close the left eye, and fix the right steadily on the left-hand ink- 
stand, gradually varying the distance of the eye to the ink-bottle. 
At a certain distance the right-hand bottle will disappear; but, 
nearer or farther than that, it will be plainly seen. 
109. Show the same thing in this way: make two black spots, 
with pen and ink, as large as two peas, upon a white card, about 
three inches apart, varying the distance as before. At a distance 
of about six inches the “blind spot ” will be noticed. 
110. Impressions made upon the Retina do not disappear at 
once. — Look steadily at a bright light for a moment or two, and 
then turn away suddenly, or shut the eyes. A gleam of light will 
be seen for a second or two. 
111. Take a round piece of white card-board the size of a 
saucer, and paint it in alternate rings of red and yellow, — two PR A C TIC A L EXPERIMENTS. 
259 
primary colors. Put it on the sewing-machine wheel, or glue it to 
a grindstone, and rotate it rapidly. The eye perceives neither 
color, but orange, — the secondary color. 
112. To note the shadows cast upon the retina by opaque mat- 
ters in the vitreous humor, popularly known as floating specks, or 
gossamer threads, look through a small pin-hole in a card at a 
bright light covered by a ground-glass shade (164, Note). 
113. To dissect an Eye. — The eyes of a fresh codfish are 
easily obtained for this purpose. Put them in the snow over night 
during winter, and freeze them with salt and ice during warm 
weather. They are far easier to cut and handle when frozen. 
Examine one specimen from the outside, however, before freezing 
dulls its bright colors. Saw out a square piece of the skull that 
holds the eye, and see just how it is held in place naturally, how 
the optic nerve enters the orbit, etc. Dissect with great care the 
frozen eye. 
The fat should be dissected off, together with the muscles, and 
the eye cut in half from above downward. This will be most 
easily accomplished by holding the eye between the forefinger 
and thumb of the left hand, upon a slice of turnip or potato, and 
then cutting it between finger and thumb with a sharp razor. 
The transparency of the cornea, lens, vitreous humor, and also 
of the retina, should be noticed, so as to compare them with the 
same parts when hardened. In the posterior portion may be seen, 
through the transparent vitreous humor, the entrance of the optic 
nerve, and the blood-vessels which radiate from this point over 
the delicate, transparent retina, the latter spreading like a film 
over the whole of the interior of this half of the eye. Remove 
the vitreous humor and the retina, so that the brightly colored 
choroid coat may be seen. 
Within the front half of the eye will be seen a portion of the 
vitreous humor and the perfectly transparent lens. 
The aqueous humor is best shown by taking an entire fresh eye, 
and cutting through the cornea, when this fluid will be seen to 
spurt out. 260 
OUR BODIES. 
Both transverse and longitudinal sections should be examined. 
The latter are best made by placing the eye upon a piece of cork, 
with the cornea downwards, and then, passing the razor through 
the middle of the optic nerve, cut the eye in half. When the 
razor is felt to be in contact with the hardened lens, cease to draw 
it, and finish the section by simply pressing it through, otherwise 
the lens will be drawn out of its place (161-165). 
114. Get a sheep’s kidney at the market. Study carefully its 
shape, size, etc., as a whole. Freeze it, if necessary, and then cut 
it in two lengthwise. Notice the difference between the inner and 
the outer portions. This is something like the difference in tex- 
ture between the pith and the hard rind of some flower-stems, 
such as the sunflower. The outer part is called the cortical part, 
which means the “bark;” and the inner is called the medullary, 
or “ marrow ” (175). 
EXPERIMENTS ON THE THROAT AND VOICE. 
Experiment 115. To show the Anatomy of the Throat (178). 
— Study the general construction of the throat by the help of a 
hand-mirror. Repeat the same on the throat of some friend. 
116. To illustrate the Passage of Air through the Glottis. — 
Take two strips of India rubber, and stretch them over the open 
end of a boy’s “bean-blower,” or any kind of a tube. Tie them 
tightly with thread, so that a chink will be left between them. 
Force the air through such a tube with a bellows, or even by blow- 
ing hard, and a sound will result if the strips are not too far apart. 
The sound will vary in character, just as the bands are made tight 
or loose. 
117. To show the Construction of the Vocal Organs (180).— 
Get a butcher to furnish two windpipes from a sheep or a calf. 
They differ somewhat from the vocal organs of the human body, 
but will enable us to recognize the different parts which have been PR A C TIC A L EXPERIMENTS. 
261 
described, and thus to get a good idea of the gross anatomy. 
One specimen should be cut open lengthwise in the middle line 
in front, and the other cut in the same way from behind. 
EXPERIMENTS ON MATTERS OF EVERY-DAY 
HEALTH. 
Experiment 118.—Imagine a pupil with his fingers or ears 
frost-bitten. Show how friction should be applied (184). 
119. Poultices (185). — Bring a small lot of the necessary ma- 
terial into the schoolroom, to show exactly how a mustard paste, a 
flaxseed poultice, or any other simple poultice, is made. A small 
poultice four inches square is large enough for the experiment. 
Let one or more pupils use the same material, and make a num- 
ber of poultices. 
120. Fainting (186) . — Select several places about the school- 
room, and show exactly how a person should be placed, supposing 
he has fainted in a crowded room. Go through every detail of 
treatment in your mind. You may have a practical test of your 
knowledge within a week. 
121. Apparent Drowning (189) . — Show exactly how artificial 
respiration is done. Let a boy lie on a settee, and illustrate the 
process in every detail. It would be an excellent idea for a 
teacher to meet his boys at their bathing-place, and show them in 
still more detail. Let two boys go through the process on a play- 
mate under the eye of the teacher, and then others might follow 
their example. Study “Dr. Marshall Hall’s treatment,” and make 
similar experiment with this if thought advisable. 
122. To carry an Injured Person (190, Note). — Take some 
one of the small boys, and show how he could be carried home 
or elsewhere in case of injury. 
123. Bin ■ns (191) . — Have a small quantity of soda, sweet-oil, 
and lime-water in the schoolroom. Imagine a pupil has burned 
his arm or hand. Show exactly what is to be done, and how. 262 
OUR BODIES. 
124. Foreign Bodies (192-195). — A thoughtful teacher can 
make several experiments to illustrate the text. 
125. Experiments on the Matter of treating Cuts and Bruises, 
and of stopping Bleeding (196).— Let red-pencil marks made on 
the face, arms, fingers, etc., stand for cuts. Apply suitable strips 
of plaster in a proper way for a great variety of imaginary cuts. 
After putting on the plaster, practise on bandaging the parts with 
strips of cotton cloth rolled for the purpose. Practise on using 
the handkerchief for a variety of bandages. 
126. To stop Bleeding from the Arteries (196). — Locate the 
principal arteries on your own person and that of a friend. Let 
red-crayon marks stand for the course of the arteries. Study this 
part of your anatomy thoroughly. Now with strings, cords, shoe- 
strings, handkerchiefs, elastics, strips of clothing, practise tying 
them so as to press deeply and firmly in the proper place. Let 
each one in the class practise at the same time on the same 
artery. Criticise and improve each other’s work. 
127. Poisons and their Antidotes (198-204). — Small samples 
of the more common and important poisons should be shown. 
Note carefully the appearance of each one. With each sample of 
poison arrange its most common antidote. Explain exactly how 
it should be given. 
128. Disinfectants (206-208). — Exhibit samples of the com- 
mon disinfectants, and show how they should be used. Most 
school-premises furnish ample opportunities to make a series of 
practical experiments on ventilation and disinfection. 
The ingenuity of both teacher and pupil will suggest many addi- 
tional experiments. 
The keynote of this chapter : Illustrate important points 
by practical experiments; try only the simplest and most 
useful things, but do well whatever is done. GLOSSARY GLOSSARY. 
The ordinary use of a glossary is to explain, in some detail, many of the more difficult words 
used in the text. The pupil will, however, find it an admirable and profitable review 
exercise, to drill himself on the spelling, derivation, and definition of each word, master- 
ing a few words every day. 
Ab-do'men (Latin abdo, abdere, to 
conceal). The largest cavity of the 
body, containing the liver, stomach, 
intestines, etc. 
Ab-sor'bents (L. absorbere, to suck 
up). The vessels which take part 
in the process of absorption. 
Ab-sorp'tion. The process of suck- 
ing up nutritive or waste matters 
by the blood-vessels or lymphatics. 
Ac-com-mo-da'tion of the Eye. 
The alteration in the shape of the 
crystalline lens, which accommo- 
dates, or adjusts, the eye for near 
and remote vision. 
Ac-e-tab'u-lum (L.acetum, vinegar). 
A little cup used by the ancients 
for holding vinegar; applied, in 
anatomy, to the round cavity in 
which the hip-bone receives the 
head of the femur. 
Ac'id (L. acidus, from acere, to be 
sour). A substance usually sour, 
sharp, or biting to the taste. 
Ad'am’s Ap'ple. An angular pro- 
jection of cartilage in the front of 
the neck. It is particularly promi- 
nent 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-bu'men, or Albumin (L. albus, 
white). An animal substance re- 
sembling the white of an egg. 
Al-bu'min-oids. A class of sub- 
stances resembling albumen: they 
may be derived from either the ani- 
mal or vegetable kingdoms. 
Al'i-ment (L. alo, to nourish). That 
which affords nourishment; food. 
Al-i-ment'a-ry Ca-nal (from ali- 
ment). A long tube in which the 
food is digested, or prepared for 
reception into the blood. 
Al'ka-li (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. 
An -aes-thet'ics (Greek an, without, 
aisthesia, feeling). Those medicinal 
agents which prevent the feeling 
of pain, such as chloroform, ether, 
laughing-gas, etc. 
265 266 
GLOSSARY 
A-nat'o-my (Gr. anatemno, to cut 
up). The science which describes 
the structure of living things. 
A-or'ta (Gr. aeireiti, to lift up). The 
largest artery of the body, arising 
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. 
A'que-ous Humor (L. aqua, water). 
The watery fluid occupying the 
space between the cornea and crys- 
talline lens of the eye. 
A-rach'noid Mem'brane (Gr. 
arachne, a spider, and eidos, like). 
The thin covering of the brain and 
spinal cord, between the dura mater 
and the pia mater. 
Ar'bor Vi'tae (L.). Literally, “the 
tree of life ; ” a name given to the 
peculiar appearance presented by a 
section of the cerebellum. 
Ar'ter-y (Gr. aer, air, and tereo, to 
contain). A vessel by which blood 
is carried away from the heart. It 
was supposed by the ancients to 
contain only air; hence the name. 
Ar-tic-u-la'tion (L. articulo, to form 
a joint). The more or less movable 
union of bones, etc.; a joint. 
A-ryt'e-noid Car'ti-la-ges (Gr. 
arutaina, a ladle). Two small car- 
tilages of the larynx, resembling 
the mouth of a pitcher. 
As-sim-i-la'tion (L. ad, to, and 
similis, like). The conversion of 
food into living tissue. 
Au'di-to-ry (L. audio, to hear) 
Nerve. One of the cranial nerves: 
it is the special nerve of hearing. 
Au'ri-cle (L. auricula, a little ear). 
A cavity of the heart. 
Bile. The gall, or peculiar secretion 
of the liver; a viscid, yellowish 
fluid, and very bitter to the taste. 
Blad'der (Saxon, bleddra, a bladder, 
a goblet). A bag, or sac, serving 
as receptacle of some secreted fluid; 
as the gall-bladder, etc. In common 
language, the receptacle of the 
urine in man and other animals. 
Bright’s Dis-ease'. A group of 
diseases of the kidney, first de- 
scribed by Dr. Bright. 
Bronch'i (Gr. bronchos, windpipe). 
The two first divisions, or branches, 
of the trachea: one enters each 
lung. 
Bronch'i-al Tubes. The smaller 
branches of the trachea within the 
substance of the lungs, terminating 
in the air-cells. 
Bronch-i'tis (from bronchos, and -ills, 
a suffix signifying inflammation). 
An inflammation of the larger 
bronchial tubes; a “ cold ” affect- 
ing the lungs. 
Bun'ion. An enlargement and in- 
flammation at the first joint of the 
great toe. 
Cal'lus (L.calico, to be thick-skinned). 
Any excessive hardness of the skin, 
caused by friction or pressure. 
Ca-nal' (L. canalis, a canal). In the 
body, any tube or passage. 
Cap'il-la-ry (L. capillus, hair). The 
smallest blood-vessels, so called be- 
cause they are so tiny. 
Car-bon'ic A'cid. The gas which is 
present in the air breathed out from 
the lungs; a waste product of the GLOSSARY. 
267 
animal kingdom, and a food of the 
vegetable kingdom. Chemical name 
is Carbon Dioxide. 
Car'di-ac (Gr. kardia, the heart). 
The cardiac orifice of the stomach 
is the upper one, and is near the 
heart; hence its name. 
Car-niv'o-rous (I.. ca'ro, flesh, and 
vo'ro, to devour). Subsisting upon 
flesh. 
Car'ron Oil. A mixture of equal 
parts of linseed-oil and lime-water, 
so called because used at the Car- 
ron Iron Works in Scotland. 
Car'ti-lage. A tough but flexible ma- 
terial, forming a part of the joints, 
air-passages, nostrils, ear; gristle. 
Ca'se-ine (L. ca'seus, cheese). The 
albuminoid substance of milk : it 
forms the basis of cheese. 
Ca-tarrhb An inflammation of a 
mucous membrane. 
Cell (I,, cella, a store-room). The 
name of the tiny microscopic ele- 
ments, which, with slender threads 
or fibres, make up most of the body; 
they were once believed to be little 
hollow chambers; hence the name. 
Cem'ent. The substance which 
forms the outer part of the fang 
of a tooth. 
Cer-e-beklum (diminutive for cer'e- 
brum, the brain). The little brain, 
situated beneath the posterior third 
of the cerebrum. 
Cer'e-brum (L.), The brain proper, 
occupying the entire upper portion 
of the skull. It is nearly divided 
into two equal parts, called “hemi- 
spheres,” by a cleft extending from 
before backward. 
Chlo'ral. A powerful drug used by 
physicians to induce sleep. 
Cho'roid (Gr. chorion, skin, and eidos, 
form). The middle coat of the 
eyeball. 
Chyle (Gr. chulos, juice). The milk- 
like fluid formed by the digestion 
of fatty articles of food in the intes- 
tines. 
Chyme (Gr. chumos, juice). The 
pulpy liquid formed by digestion 
in the stomach. 
Cil'i-a (pi. of cil'i-um, an eyelash). 
Minute hair-like processes found 
upon the cells of the air-passages, 
and other parts that are commonly 
moist. 
Cir-cu-la'tion (L. cir'cuius, a circle). 
The course of the blood through 
the blood-vessels of the body. 
Co-ag-u-laTion (L. coag'ulo, to 
curdle). Applied to the process by 
which the blood clots or solidifies. 
Coch'le-a (L. coch'lea, a snail-shell). 
The spiral cavity of the internal 
ear. 
Conch'a (Gr. konche, a mussel-shell). 
The shell-shaped portion of the ex- 
ternal ear. 
Con-ges'tion (Tv. con, together, and 
gero, to bring). An unnatural gath- 
ering of blood in any part of the 
body. 
Con-junc-ti/va (L. con, together, 
and jun'go, to join). A thin layer of 
mucous membrane which lines the 
eyelids, and covers the front of the 
eyeball, thus joining the latter to 
the lids. 
Con-nect'ive Tis'sue. The net- 
work which connects the minute 268 
GL OSSARY. 
parts of most of the structures of 
the body. 
Con-sti-pa'tion (L. con, together, and 
stipo, to crowd close). Costive ness; 
tardiness in evacuating the bowels. 
Con-sump'tion (L. consumo, to con- 
sume). A disease of the lungs, 
attended with a fever and cough, 
and causing a gradual decay of the 
bodily powers. The medical name 
is phthisis. 
Con-trac-til'i-ty (L. con, together, 
and tra'ho, to draw). The property 
of a muscle which enables it to 
contract, or draw its extremities 
closer together. 
Con-vo-lu'tions (L. con, together, 
and vol'vo, to roll). The tortuous 
foldings of the external surface of 
the brain. 
Con-vul'sion (L. convel'lo, to pull to- 
gether). A more or less violent 
agitation of the limbs or body. 
Corn (L. cor'mi, a horn). A small 
portion of the outer skin, of horn- 
like hardness. 
Cor'ne-a (L. cor'nu, a horn). The 
transparent, horn-like substance 
which covers a part of the front of 
the eyeball. 
Cor'pus-cles, Blood (L. dim. of cor'- 
pus, a body). The small disks 
which give to the blood its red 
color: the white corpuscles are 
globular and larger. 
Cos-met'ic (Gr. kosmeo, to adorn). 
Applied to articles which are sup- 
posed to increase the beauty of the 
skin. 
Cra'ni-al (L. cra'nium, the skull). 
Pertaining to the skull. 
Cri'coid (Gr. kri'kos, a ring, and eidos, 
form). A cartilage of the larynx, 
resembling a seal-ring in shape. 
Crys'tal-line Lens (L. crystal'lum, a 
crystal). One of the so-called 
humors of the eye; a double-con- 
vex body situated in the front part 
of the eyeball. 
Cu'ti-cle (L. dim. of cu'tis, the skin). 
The scarf-skin; also called the epi- 
der'mis. 
Cu'tis (Gr. skutos, a skin, or hide). 
The true skin, lying beneath the 
cuticle; also called the der'mis. 
Dan'druff. The small scales, or par- 
ticles, which separate from the 
scarf-skin of the scalp. 
De-cus-sa'tion (L. decus'sis, the Ro- 
man numeral ten, X.). A reciprocal 
crossing of fibres from side to side. 
De-gen-er-a'tion (L. degenerare, to 
grow worse; to deteriorate). A 
change in the structure of any organ 
which makes it less fit to perform 
its duty or function. 
Deg-lu-ti'tion (L. deglutire, to swal- 
low down). The act, or process, of 
swallowing. 
De-lir'i-um. A state in which the 
ideas of a person are wild, irregular, 
and unconnected. 
Den'tine (L. dens, dentis, a tooth). 
The hard substance which forms 
most of a tooth; ivory. 
De-o-do-ri'zer. An agent which 
corrects any foul or unwholesome 
odor. 
Di'a-phragm (Gr. diaphrasso, to di- 
vide by a partition). A large, thin 
muscle which separates the cavity 
of the chest from the abdomen. GLOSSARY. 
269 
Ep'i-lep-sy (Gr. epilepsis, a seizure). 
A nervous disease accompanied by 
fits in which consciousness is lost. 
The falling sickness. 
Eu-sta'chi-an (from an Italian ana- 
tomist named Eustachi). The tube 
which leads from the throat to the 
middle ear, or tympanum. 
Ex-cre'tion (L. excer'no, to separate). 
The separation from the blood of 
the waste matters of the body; also, 
the materials excreted. 
Ex-pi-ra'tion (L. expi'ro, to breathe 
out). The act of forcing air out of 
the lungs. 
Ex-ten'sion (L. ex, out, and ten'do, 
to stretch). The act of restoring a 
limb, etc., to its natural position 
after it has been flexed, or bent; the 
opposite of flexion. 
Fau'ces. The part of the mouth 
which opens into the pharynx. 
Fe-nes'tra (L). Literally, a win- 
dow ; the opening between the mid- 
dle and internal ear. 
Fi'bre (L. fibra, a filament). One of 
the tiny threads of which many 
parts of the body are composed. 
Fi'brine (L.fibra, a fibre). An al- 
buminoid substance found in the 
blood. 
Flex'ion (L. flccto, to bend). The 
act of bending a limb, etc. 
Fol'li-cle (L. dim. of fol'lis, a money- 
bag). A little pouch, or depression, 
in a membrane. 
Fo-men-ta'tion (L. fo'veo, to keep 
warm). The application of any 
warm, soft, medicinal substance to 
some part of the body by which the 
vessels are relaxed. 
Di-ar-rhce'a (Gr. diarrhein, to flow 
through). An unnaturally frequent 
and liquid evacuation of the bowels. 
Dif-fus'ion of Gases. The power of 
gases to become intimately mingled. 
Dis-in-fect'ant. Agents used to 
destroy the causes of infection. 
Dis-lo-ca'tion (L. dislocare, to put 
out of place). The name of an in- 
jury to a joint, in which the bones 
are forced out of their sockets. 
Dis-sec'tion (L. dis, apart, and seco, 
to cut). The cutting up of an ani- 
mal in order to learn its structure. 
Duct (L. du'co, to lead). A narrow 
tube : the thoracic duct is the main 
trunk of the absorbent vessels. 
Du-o-de'num (L. ditode'ni, twelve). 
The first division of the small intes- 
tines, about twelve fingers’-breadth 
long. 
Dys-pep'si-a (Gr. dies, ill, peptein, to 
digest). A condition of the ali- 
mentary canal in which it digests 
imperfectly. Indigestion. 
El'e-ment. One of the simplest 
parts of which any thing consists. 
E-met'ic (Gr. emeo, to vomit). Hav- 
ing power to excite vomiting. Also, 
a medicine which causes vomiting. 
E-mul'sion (L. emulgere, to milk). 
Oil in a finely divided state, sus- 
pended in water. 
En-am'el (French, email). The 
dense material which covers the 
crown of a tooth. 
Ep-i-glot'tis (Gr. epi, upon, and glot- 
tis, the entrance to the windpipe). 
A leaf-shaped piece of cartilage 
which covers the top of the larynx 
during the act of swallowing. 270 
GLOSSARY 
Fo-ra'men. A hole, or aperture. 
Fu-mi-ga'tion (L. fu’migo, to per- 
fume a place). The use of certain 
fumes to counteract contagious ef- 
fluvia. 
Function (L. functio, a doing). The 
special duty of any organ of the 
body. 
Fun'gous Growths (L. fun’gus, a 
mushroom). A low grade of vege- 
table life. 
Gan'gli-on (Gr. ganglion, a knot). A 
knot-like swelling in the course of 
a nerve ; a smaller nerve-centre. 
Gas'tric (Gr. gaster, stomach). Per- 
taining to the stomach. 
Gel'a-tine (I,, gelo, to congeal). An 
animal substance which dissolves 
in hot water, and forms a jelly on 
cooling. 
Gland (L. glans, an acorn). An organ 
consisting of follicles and ducts, 
with numerous blood-vessels inter- 
woven. 
Glot'tis (Gr. glotta, the tongue). The 
narrow opening between the vocal 
cords. 
Glu'ten. Literally, glue ; the glutin- 
ous albuminoid ingredient of wheat. 
Groin. The lower part of the abdo- 
men just above the thigh. 
Gus-ta'tion (L. gusto, to taste). The 
sense of taste. 
Gus'ta-to-ry Nerve. The nerve of 
taste supplying the front part of the 
tongue, a branch of the “ fifth ” pair. 
Gym-nas'tics (Gr. gumnazo, to exer- 
cise). The practice of athletic 
exercises. 
Hem'i-spheres (Gr. herni, half, and 
sphaira, a sphere). Plalf a sphere, 
the lateral halves of the cerebrum, 
or brain proper. 
Hem'or-rhage (Gr. hai'ma, blood, 
and regnumi, to burst). Bleeding, 
or the loss of blood. 
He-pat'ic (Gr. hepar, the liver). Per- 
taining to the liver. 
Her-biv'o-rous (L. her'bet, an herb, 
and vo'ro, to devour). Applied to 
animals that subsist upon vegetable 
food. 
H ic'cough. A convulsive motion of 
some of the muscles used in breath- 
ing, accompanied by a shutting of 
the glottis. 
Hu'mor. Moisture; the humors are 
transparent contents of the eye- 
ball. 
Hy-dro-pho'bi-a (Gr. hitdor, water, 
and phobeomai, to fear). A disease 
caused by the bite of a rabid dog 
or other animal. 
Hy'gi-ene (Gr. hygieia, health). The 
art of preserving health, and pre- 
venting disease. 
In-ci'sor (L. inci'do, to cut). Ap- 
plied to the four front teeth of both 
jaws, which have sharp, cutting 
edges. 
In'cus. An anvil; the name of one 
of the bones of the middle ear. 
In'di-an Hemp. The common 
name of Cannabis Indica, an intoxi- 
cating drug, known as hasheesh and 
many other names, in Eastern 
countries. 
In-fe'ri-or Ve'na Ca'va (L.). Lower 
hollow vein; the chief vein of the 
lower part of the body. 
In-flam-ma'tion (L. prefix in, and 
flammo, to flame). A redness or GLOSS A/IV. 
271 
swelling of any part of the body, 
with heat and pain. 
In-sal-i-va'tion (L. in, and sali'va, 
the fluid of the mouth). The min- 
gling of the saliva with the food 
during the act of chewing. 
In-spi-ra'tion (L. inspi'ro, spira'tum, 
to breathe in). The act of drawing 
in the breath. 
In-teg'u-ment (L. inte'go, to cover). 
The skin, or outer covering of the 
body. 
In-tes'tine (L. in'tns, within). The 
part of the alimentary canal which 
is continuous with the lower end of 
the stomach; also called the bowels. 
I'ris (L. i'ris, the rainbow). The 
thin, muscular ring which lies be- 
tween the cornea and crystalline 
lens, and which gives the eye its 
special color. 
Jaun'dice (Fr. jaunisse, yellow). A 
disorder in which the skin and eyes 
assume a yellowish color. 
Lab'y-rinth. The internal ear, so 
named from its many windings. 
Lach'ry-mal Ap-pa-ra'tus (L. lach'- 
ryma, a tear). The organs for 
forming and carrying away the 
tears. 
Lac'te-als (L. lac, lac'tis, milk). The 
absorbent vessels of the small in- 
testines. 
Lar'ynx. The cartilaginous tube 
situated at the top of the windpipe, 
or trachea; the organ of the voice. 
Lens. Literally, a lentil; a piece of 
transparent glass or other substance 
so shaped as either to converge or 
disperse the rays of light. 
Lig'a-ment (L. li'go, to bind). A 
strong, fibrous material binding 
bones or other solid parts together: 
it is especially necessary to give 
strength to joints. 
Lig'a-ture (L. ligo, to bind). A thread 
of some material used in tying a cut 
or injured artery. 
Lobe. A round, projecting part of 
an organ, as of the liver, lungs, or 
brain. 
Lymph (L. lym'pha, pure water). 
The watery fluid conveyed by the 
lymphatic vessels. 
Lym-phat'ic Ves'sels. A system 
of absorbent vessels, 
i Mal'le-us. Literally, the mallet; 
one of the small bones of the mid- 
dle ear. 
Mar'row. The soft, fatty substance 
contained in the central cavities of 
the bones. 
Mas-ti-ca'tion (L. mas'tico, to chew). 
The act of cutting and grinding the 
food to pieces by means of the 
teeth. 
Me-a'tus (L. meare, to wander). A 
passage or channel. 
Me-dul'la Ob-lon-ga'ta. The “ob- 
long marrow,” or nervous cord, 
which is continuous with the spinal 
cord within the skull. 
Mem-bra'r.a Tym'pan-i. Liter- 
ally, the membrane of the drum; a 
delicate partition separating the 
outer from the middle ear; it is 
sometimes incorrectly called the 
drum of the ear. 
Mem'brane. A thin layer of tissue 
serving to cover some part of the 
body. 
Mi'cro-scope (Gr. mikros, small, 272 
GLOSSARY. 
and skopeo, to look at). An optical 
instrument which assists in the ex- 
amination of minute objects. 
Mo'lar (L. mo'la, a mill). The name 
applied to the three back teeth of 
each side of the jaw; the grinders, 
or mill-like teeth. 
Mo'tor (L. mo'veo, mo'lum, 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. The glairy fluid which is 
secreted by mucous membranes, 
serving to keep them in a moist 
condition. 
My-o'pi-a (Gr. muo, to shut, and 
ops, the eye). A defect of vision 
dependent upon an eyeball that is 
too long, rendering distant objects 
indistinct; near-sight. 
Na'sal (L. na'sus, the nose). Per- 
taining to the nose. 
N ar-cot'ic (Gr. narkoo, to benumb). 
A medicine, which, in poisonous 
doses, produces stupor, convulsions, 
and sometimes death. 
Nerve Cell. A minute, round, and 
ashen-gray cell found in the brain 
and other nervous centres. 
Nerve Fi'bre. An exceedingly 
slender thread of nervous tissue. 
Nos'tril (Anglo-Saxon, nosu, nose, 
and thyrl, a hole). One of the two 
outer openings of the nose. 
Nu'cle-us (L. mix, a nut). A cen- 
tral part of any body, or that about 
which matter is collected. In 
anatomy, a cell within a cell. 
Nu-cle'o-lus (diminutive of nu'cleus). 
A little nucleus. 
Nu-tri'tion (L. nu'trio, to nourish). 
The processes by which the nour- 
ishment of the body is accomplished. 
O-don'toid (Gr. odous, a tooth, eidos, 
shape). The name of the bony 
peg of the second vertebra, around 
which the first turns. 
CE-soph'a-gus. Literally, that which 
carries food. The tube leading from 
the throat to the stomach; the gullet. 
O-le-ag'i-nous (L. o'leum, oil). Of 
the nature of oil; applied to an im- 
portant group of food-principles, — 
the fats. 
Ol-fac'to-ry (L. olfa'cio, to smell). 
Pertaining to the sense of smell. 
Op'tic (Gr. opto, to see). Pertaining 
to the sense of sight. 
Or'bit (L. or'bis, a circle). The bony 
socket or cavity in which the eye- 
ball is situated. 
Or'gan (L. organum, an instrument 
or implement). A portion of the 
body having some special function 
or duty. 
O s'se-ous (L. os, a bone). Consist- 
ing of, or resembling, bone. 
Pal'ate the palate). The 
roof of the mouth, consisting of 
the hard and soft palate. 
Pal-pi-ta'tion (L. palpitatio, a fre- 
quent or throbbing motion). A vio- 
lent and irregular beating of the 
heart. 
Pa-pil'la. The name of the small 
elevations found on the skin and 
mucous membranes. GLOSSARY. 
273 
Pa-raFy-sis (Gr.paraluein, to loosen, 
also, to disable). Loss of function, 
especially of motion or feeling. 
Palsy. 
Par'a-site. A plant or animal that 
grows or lives on another. 
Pa-tel'la (L. dim. of pat'ina, a pan). 
The knee-pan. 
Pel'vis. Literally, a basin. The 
bony cavity at the lower part of the 
trunk. 
Pep'sin (Gr. pepto, to digest). The 
active principle of the gastric juice. 
Per-i-car'di-um (Gr. peri, about, 
and kardia, heart). The sac enclos- 
ing the heart. 
Per-i-os'te-um (Gr. peri, around, 
osteon, a bone). A fibrous mem- 
brane which surrounds the bones. 
Per-i-stal'tic Move'ments (Gr. 
peri, round, and stello, to send). 
The slow, wave-like movements of 
the stomach and intestines. 
Per-i-to-ne'um (Gr. periteino, to 
stretch around). The investing 
membrane of the stomach, intes- 
tines, and other abdominal organs. 
Per-spi-ra'tion (L. perspi'ro, to 
breathe through). The sweat. 
Pe'trous (Gr. petra, a rock). The 
name of the hard portion of the 
temporal bone, in which is situated 
the drum of the ear and labyrinth. 
Pha-lan'ges (Gr. phalanx, a body of 
soldiers closely arranged in ranks 
and files). The bones of the fingers 
and toes. 
Phar'ynx (Gr. pharunx, the throat). 
The cavity between the back of the ( 
mouth and gullet. 
Phys-i-ol'o-gy (Gr. phusis, nature, | 
and logos, a discourse). The science 
of the functions of living, organized 
beings. 
Pi'a M a'ter (L.). laterally, the ten- 
der mother; the innermost of the 
three coverings of the brain. It is 
thin and delicate; hence the name. 
Pig'ment (L. pingo, to paint). Color- 
ing-matter. 
Plas'ma (Gr. plasso, to mould). Any 
thing formed or moulded. The 
liquid part of the blood. 
Pleu'ra (Gr. pleura, the side, also, a 
rib). A membrane covering the 
lung, and lining the chest. 
Pleu'ri-sy. An inflammation affect- 
ing the pleura. 
Pneu-mo-gas'tric (Gr.pneumon, the 
lungs, and gas ter, the stomach). It 
is the principal nerve of respira- 
tion ; also called the vagus, or wan- 
dering nerve. 
Pneu-mo'nia. An inflammation af- 
fecting the air-cells of the lungs. 
Poi'son (Fr. poison). Any substance, 
which, when applied externally, or 
taken into the stomach or the blood, 
works such a change in the animal 
economy as to produce disease or 
death. 
Por'tal Vein (L. porta, a gate). 
The venous trunk formed by the 
union of all the veins coming from 
the intestines. It carries the blood 
to the liver. 
Pres-by-o'pi-a (Gr. presbus, old, and 
ops, the eye). A defect of the ac- 
commodation of the eye, caused by 
the hardening of the crystalline 
lens ; the “ far-sight ” of adults and 
aged persons. 274 
GL OSS ARY. 
Proc'ess (L. proce'do, proces'sus, to 
proceed, to go forth). Any projec- 
tion from a surface; also, a method 
of performance; a procedure. 
Pro'te-id (Gr. protos, first, and eidos, 
form). An element allied to nitro- 
gen; a substance containing such 
elements; an albuminoid. 
Pty'a-lin (Gr. ptualon, saliva). The 
peculiar organic ingredient of the 
saliva. 
Pul'mo-na-ry (L. pul'mo, pulmo'nis, 
the lungs). Pertaining to the lungs. 
Pulse (L. pel'lo, pul'sum, to beat). 
The striking of an artery against 
the finger, occasioned by the con- 
traction of the heart, commonly felt 
at the wrist. 
Pu'pil (L. pupil'la). The central, 
round opening in the iris, through 
which light passes into the interior 
of the eye. 
Py-lo'rus (Gr. puloros, a gate- 
keeper). The lower opening of 
the stomach, at the beginning of the 
small intestine. 
Re'flex (L. reflexus, turned back). 
The name given to involuntary 
movements produced by an excita- 
tion travelling along a sensory to a 
centre, where it is turned back or 
reflected along motor nerves. 
Re'nal (L. renes, the kidneys). Per- 
taining to the kidneys. 
Res-pi-ra'tion (L. respi'ro, to breathe 
frequently). The function of breath- 
ing, comprising two acts, — inspira- 
tion, or breathing in; and expira- 
tion, or breathing out. 
Ret'i-na (L. re'te, a net). The inner- 
most of the three tunics, or coats, 
of the eyeball, being an expansion 
of the optic nerve. 
Sac'cha-rine (L. sac'charum, sugar). 
Of the nature of sugar; applied to 
the group of food-substances which 
embraces the different varieties of 
sugar, starch, and gum. 
Sa-li'va. The moisture, or fluids, of 
the mouth, secreted by the salivary 
glands. The spittle. 
Scle-rot'ic (Gr. skleros, hard). The 
tough, fibrous, outer coat of the 
eyeball. 
Se-ba'ceous (L. sebum, fat). Re- 
sembling fat; the name of the oily 
secretion by which the skin is kept 
flexible and soft. 
Se-cre'tion (L. secer'no, secre'tum, to 
separate). The process of separat- 
ing from the blood some essential, 
important fluid; which fluid is also 
called a secretion. 
Sem-i-cir'cu-lar Ca-nals. Three 
canals in the internal ear. 
Sem-i-lu'nar (L. semi, half, luna, 
mooned). Shaped like a half-moon. 
Sen-sa'tion. The perception of an 
external impression by the nervous 
system. . 
Se'rum. The clear, watery fluid 
which separates from the clot of 
the blood. 
Sock'et (L. soccus, a kind of low- 
heeled shoe). An opening into 
which any thing is fitted. 
Spasm (Gr. spasmos, convulsion). A 
sudden, violent, and involuntary 
contraction of one or more muscles. 
| Spe'cial Sense. A sense by which 
we receive particular sensations, dif- 
fering from those of general sensi- GLOSSARY. 
275 
bility; such as those of sight, hear- 
ing, taste, and smell. 
Sprain. An injury to the ligaments 
or tendons about a joint. 
Sta'pes. Literally, a stirrup; one 
of the small bones of the middle 
ear, shaped somewhat like a stir- 
rup. 
Stim'u-lant (L. stimulo, 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 (L. strio, to furnish with 
channels). Marked with fine, par- 
allel lines. 
Sub-cla'vi-an Vein (L. 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 (L. upper 
hollow vein). The great vein of 
the upper part of the body. 
Sut'ure (L. sutura, a seam). The 
union of certain bones of the skull 
> by the interlocking of jagged edges. 
Sym-pa-thet'ic Sys'tem of Nerves. 
A double chain of nervous gan- 
glia, connected by numerous small 
nerves, situated chiefly in front of, 
and on each side of, thfe spinal col- 
umn. 
Symp'tom (Gr. sun, with, and pipto, 
to fall). A sign, or token, of dis- 
ease. 
Syn-ov'i-al (Gr. sun, with, oon, an 
egg). The liquid which lubricates 
the joints; joint-oil. So called from 
its resemblance to the white of a 
raw egg. 
Sys-tem'ic. Belonging to the sys- 
tem, or body, as a whole. 
Sys'to-le (Gr. sustello, to contract). 
The contraction of the heart by 
which the blood is expelled from 
that organ. 
Tac'tile (L. tac'tus, touch). Relating 
to the sense of touch. 
Tar'tar. A hard crust which forms 
on the teeth, and is composed of 
salivary mucus, animal matter, and 
a compound of lime. 
Tem'po-ral (L. tem'pus, time, and 
tem'pora, the temples). Pertaining 
to the temples; so called because 
the hair begins to turn white with 
age in that portion of the scalp. 
Ten'don (L. ten'do, to stretch). The 
white, fibrous cord, or band, by 
which a muscle is attached to a 
bone; a sinew. 
Tet'a-nus (Gr. teino, to stretch). A 
disease marked by persistent con- 
tractions of all or some of the volun- 
tary muscles; those of the jaw are 
sometimes solely affected; the dis- 
order is then termed locked-jaw. 
Tho'rax (Gr. thorax, a breast-plate). 
The upper cavity of the trunk of 
the body, containing the lungs, 
heart, etc.; the chest. 
Thy'roid (Gr. thureos, a shield, and 
eidos, form). The largest of the 
cartilages of the larynx: the pro- 
jection in the front of the neck is 
called “ Adam’s apple.” 
Tis'sue. Any substance or texture 
in the body formed of various ele- 
ments, such as cells, fibres, blood- 
vessels, etc., interwoven with each 
other. 276 
GLOSSARY 
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 (Gr. trachus, rough). The 
windpipe, or the largest of the air- 
passages. 
Trans-fu'sion (L. transfun'do, to 
pour from one vessel to another). 
The operation of injecting blood 
taken from one person into the 
veins of another: other fluids than 
blood are sometimes used. 
Trich-i'na Spi-ra'lis. (A twisted 
hair.) A minute species of para- 
site, or worm, which infests the 
flesh of the hog : may be introduced 
into the human system by eating 
pork not thoroughly cooked. 
Tym'pa-num (Gr. tumpanon, a 
drum). The cavity of the middle 
ear, resembling a drum in being 
closed by two membranes. 
U-re'a (L. urina, urine). One of the 
principal constituents of the urine, 
secreted from the blood by the 
kidneys. 
U -re'ter (Gr. ourein, to pass water). 
The excretory duct of the kidneys. 
U'vu-la (L. uva, a grape). The 
small, pendulous body attached to 
the back part of the palate. 
Var'i-cose (L. varix, a dilated vein). 
An unhealthily distended or en- 
larged vein. 
Vas'cu-lar (L. vasculum, a little ves- 
sel). Pertaining to, or possessing, 
blood or lymph vessels. 
V e'nous (L. ve'na, a vein). Pertain- 
ing to, or contained within, a vein. 
Ven-ti-la'tion. The introduction of 
fresh air into a room or building in 
such a manner as to keep the air 
within it in a pure condition. 
Ven'tri-cles of the Heart. The 
two largest cavities of the heart, 
situated at its apex, or point. 
Ver'te-bral Col'umn (L. ver'tebra, a 
joint). The backbone; also called 
the spinal column and spine. 
Ves'ti-bule. A portion of the inter- 
nal ear, communicating with the 
semicircular canals and the cochlea; 
so called from its fancied resem- 
blance to the vestibule, or porch, of 
a house. 
Vil'li (L. vil'lus, shaggy hair). 
Minute, thread-like projections 
found upon the internal surface of 
the small intestine, giving it a vel- 
vety appearance. 
Vit're-ous (L. vi'trum, glass). Hav- 
ing the appearance of glass ; applied 
to the humor occupying the largest 
part of the cavity of the eyeball. 
Viv-i-sec'tion (L. vi'vus, alive, and 
se'co, to cut). The practice of ope- 
rating upon living animals, for the 
purpose of studying some physio- 
logical process. 
Vo'cal Cords. Two elastic bands, 
or ridges, situated in the larynx; 
the essential parts of the organ of 
voice. INDEX. INDEX. 
PAGE 
Abdomen 8, 19 
Absorption 76 
by blood-vessels 79 
by the lacteals 76 
Achilles, Tendon of 28, 41 
Acids, Poison from 222 
Adam’s apple . .. . . . . no, 201 
Air, Atmospheric 115 
Changes in, from breathing . . 115 
Carbonic acid in 117 
Impurities in 118 
renovation by ventilation. . . 119 
Air-cells of the lungs 112 
Air-passages no 
Albumens 53 
Albuminoid substances 53 
Alcohol 59 
as a food 61 
how it gets into the blood . . 106 
and work 62 
and bodily heat 122 
Drinks that contain .... 60 
Proper use of 205 
Effect of, upon nervous system. 157 
Effect of, on digestion ... 88 
Effect of, on muscles .... 48 
Effect of, upon the circulation . 105 
Effect of, upon the heart . . . 107 
Effect of, upon the lungs . . 122 
Effect of, upon liver .... 89 
Effect of, upon kidneys . . . 197 
Indigestion due to 87 
Inherited craving for .... 160 
Alcoholic excess and nervous system, 158 
TAGE 
Alcoholic excess, Result of ... 159 
Alexis St. Martin 88 
Alimentary canal 65 
Alkaline poisons 223 
Anatomy defined 4 
Animal life 1 
Animal heat 120 
how produced 121 
how regulated 122 
and alcohol 122 
Ankle-bones 27 
Appetizers 54 
Aqueous humor 183 
Arachnoid membrane 145 
Arteries 99 
Principal 99 
Artificial drinks 57 
Arytenoid cartilage 201 
Asphyxia 209 
Auditory canal 175 
Auricles of the heart 97 
Backbone 20 
Baths, how and when to take them . 134 
Bile 75 
Uses of 75 
Bladder, Gall 75 
Bleeding, how stopped 215 
Bleeding from stomach and lungs . 217 
Blood 9, 92 
Circulation of 102 
Coagulation of 94 
corpuscles, Red 93 
corpuscles, White 94 
Total quantity ok 93 
279 280 
INDEX. 
PAGE 
Blood, Uses of the 92 
Blood-vessels connected with heart. 98 
Body, minute structure of ... . 5 
General build of 7 
compared to locomotive ... 2 
and its nervous system ... 2 
Elements in the 6 
Bony levers of the 41 
Bone, how made up 12 
General structure of .... 12 
Minute structure of 13 
Bones, Hints about health of . . . 32 
how joined 30 
how tied together 31 
Repair of 29 
Test questions on 33 
Uses of 29 
Different shapes of 13 
Bowels, Care of the 86 
Brain 143 
Principal masses of 144 
Bread 55 
Breathe, How we 113 
Why we 109 
Bronchial tubes 111 
Bronchi no 
Bruises, how treated 217 
Burns 213 
Caffeine 58 
Canaliculi 14 
Canals, Haversian 14 
Capillaries 101 
Carbonic acid 117 
exhaled from the lungs . . . 117 
in the air 118 
Carpal bones 25 
Cartilage 30 
Arytenoid 201 
Cricoid 201 
Thyroid 201 
Cells 6 
Cerebellum 145 
Cerebrum 144 
PAGE 
Chest 8, 19 
Chewing of the food 66 
Chloral 166 
Chocolate 58 
Choroid coat of the eye 181 
Chyle 76 
Chyme 74 
Cilia hi 
Circulation, General plan of . . . 95 
of the blood 102 
Rapidity of 104 
through the heart 103 
through the lungs . . . . . 103 
Clavicle 24 
Clothing, Why we need 136 
Hints on use of 136 
Coagulation of the blood .... 94 
Coccyx 21 
Cochlea 177 
Cocoa 57 
Coffee 57 
Effects of 58 
Constipation 86 
Collar-bone 24 
Color-blindness 187 
Column, Spinal 20 
Conjunctiva 186 
Contraction of muscles 38 
Convulsions 209 
Cooking food 86 
Cords, Vocal 110,202 
Cornea 181 
Corpuscles, Blood 93 
Cranial nerves 146 
Cranium, Bones in 16 
Cricoid cartilage 201 
Crystalline lens 183 
Cuticle .125 
Cutis 125 
Decussation of motor and sensory 
fibres of spinal cord . . . . 151 
Diaphragm 8, 19 
Movements of the, in respiration, 114 281 
INDEX. 
PAGE | 
Diet, Different articles of ... . 55 
Digestion 9, 65 
General plan of 65 
Gastric 72 
Intestinal 74 
Disinfectants, what to use .... 226 
How to use 227 
Disinfection 225 
Drinks, Artificial 57 
Drowning 210 
Duct, Biliary 74 
Pancreatic 74 
Tear 187 
Thoracic 78 
Duodenum 74 
Dura Mater 145 
Ear 174 
Outer 175 
Inner 177 
Middle 175 
Care of the 178 
Bones'of the 176 
Elements in the body 6 
Emulsion of fats in digestion ... 75 
Enamel of the teeth 66 
Epiglottis. 7°, 11 o, 199 
Epileptic fits 209 
Ethmoid bone 17 
Eustachian tube 176 
Excretion 9, 68, 192 
Organs of 193 
Exercise, Effect of 46 
Amount of 46 
Different kinds of 47 
Time for 47 
why we need it 45 
Experiments, Hints and helps . . 231 
on bones 234 
on skeleton 235 
with muscles 237 
on food and drink 239 
on digestion 243 
on heart and the circulation . . 248 
PAGE 
Experiments on lungs and breathing, 251 
on the skin 253 
on the nervous system . . . 253 
on special senses 256 
on throat and voice 260 
on matters of every-day health . 261 
Expiration 113 
Movements of 115 
Extensor muscles 39 
Extra foods 54 
Eye 180 
Muscles of 185 
Coats of the 181 
Inside of the 182 
Eyebrows 186 
Eyelashes 186 
Eyelids 186 
Eyes, Care of the 188 
Face, Bones in the 17 
Fainting 208 
Far-sight 188 
Fats 54 
Femur 27 
Fibres, Muscular 36 
Fibrine of the blood 95 
Fibula 27 
Flexor muscles 39 
F ontanelles 19 
Food 9 
why we need it 52 
Vegetable 55 
Animal 56 
Mineral 56 
Definition of a 52 
how it is swallowed 70 
how much to eat 81 
what to eat 83 
when to eat 84 
how to eat 85 
Foods, Classes of 53 
Nitrogenous 53 
- Mineral 54 
Extra 54 282 
INDEX 
PAGE 
Foot 27 
Foreign bodies in throat .... 213 
in nose 214 
in eye 215 
in ear 214 
Frontal bone 16 
Frost-bite 206 
Function defined 5 
Gall-bladder 75 
Gases, Interchange of, in the lungs. 116 
Gastric digestion 72 
Gastric juice 73 
Action of 73 
Gland, Thymus 80 
Thyroid. < ...... 80,201 
Glands 68 
Oil 130 
Salivary 69 
Sweat 131 
Glottis. 110,202 
Gullet 70 
Hair 128 
Hand, The 25 
Head 14 
Bones of, how joined .... 18 
Hear, How we 177 
Hearing, Sense of 174 
Heart 96 
Beating of the 104 
Blood-vessels connected with . 98 
Cavities of the 97 
Circulation through the . . . 103 
Sounds of the 104 
Valves of the 98 
Work done by the 97 
Heat, Bodily 120 
and alcohol 122 
Heatstroke 211 
Hemispheres of brain 145 
Hips , 23 
Humor, Aqueous 183 
Crystalline lens 183 
Vitreous 183 
PAGE 
Hygiene defined 4 
Hyoid bone 23 
Indigestion due to alcohol .... 87 
Injured person, How to carry . . . 212 
Inorganic substances in food ... 54 
Insalivation 69 
Inspiration ,..113 
Movements of 115 
Intestinal digestion 74 
juice 76 
Intestine, Large 80 
Small 74 
Intestines. 74 
Villi of the 4 77 
Iris 182 
Iron in the blood ....... 57 
Jaw-bone, Upper ........ 18 
Lower 18 
Joint between skull and spine . . 22 
between bones of the head . . 18 
J oints 30 
Kinds of . . , 30 
Juice, Gastric 73 
Intestinal 76 
Pancreatic . 75 
Kidneys 194 
Health of 196 
Effect of alcohol upon . . . 197 
Knee-pan 27 
Labyrinth 177 
Lachrymal bone ....... 18 
Lacteals 77 
Absorption by 76 
Lacunse 14 
Large intestine 80 
Larynx 110,201 
Lens, Crystalline 183 
Levers, Bony, of the body .... 41 
Classes of, in the body ... 42 
Ligaments 31 
Limbs, Upper 23 
Lower 26 
Lime in the bones 12 INDEX. 
283 
PAGE 
Liver 74 
Effects of alcohol upon ... 89 
Locomotive, Body compared to . . 2 
Lungs in 
Structure of 112 
Lymph 79 
Lymphatic vessels 79 
Malar bone 18 
Marrow of the bones 13 
Mastication 66 
Medulla oblongata 145 
Membrane of the tympanum . . . 175 
Metacarpal bones 25 
Metatarsal bones 28 
Moutfi 66 
Muscles 9,36 
-Structure of 36 
how they act 38 
Kinds of 38 
Arrangement of 39 
Important 43 
Effect of alcohol on .... 48 
Origin of 39 
Insertion of 39 
Nails 130 
Care of the 130 
Narcotics and stimulants . . . . 157 
Nasal bone 18 
Near-sight 187 
Nerve, Auditory 177 
Optic 185 
Nerves 143 
Cranial 146 
Spinal .150 
sensory, Function of the . . . 150 
motor, Function of the . . . 150 
Sympathetic system of . . . 151 
Nerve tissue 142 
Nervous system 9,140 
and the body 2 
compared to telegraph system . 141 
Two distinct parts of ... . 142 
Health of the 154 
PAGE 
Nervous system, Abuse of the . . 155 
Effect of alcohol upon. . . . 157 
and alcoholic excess .... 158 
Nostrils no 
Occipital bone 17 
Oils and fats 54 
Oil-glands 130 
Opium 163 
Practical hints about .... 165 
Organ defined 5 
Palate bones 18 
Palpitation of the heart 105 
Pancreas 75 
Pancreatic juice 75 
Papillae . 128 
Parietal bones 17 
Passages, Air no 
Patella . 27 
Pelvis 23 
Pepsin 73 
Periosteum 13 
Peristaltic action of the stomach . . 73 
Perspiration, Uses of 132 
Phalanges 25 
Pharynx . . 70 
Physiology defined 4 
Pia mater 145 
Plasma of the blood 93 
Pleura 113 
Pneumogastric nerve 146 
Poisons and their antidotes . . . 220 
Poultices 207 
Practical points 138 
Pulmonary veins 98 
artery 99 
Pulse 105 
Pylorus 72 
Questions, Test, for review . 10, 33, 50, 
63, 9T 107, 124, i39> 
167, 190,198, 203, 229 
Radius 25 
Reading, Collateral . 10, 33, 49, 90, 107, 
123, 138, 167, 190, 198, 203, 229 284 
INDEX. 
PAGE 
Sleep, Necessity for ...... 152 
amount required 153 
Small intestine 74 
Smell, Sense of 172 
Special senses 9,170 
Speech, Organ of 201 
Sphenoid bone 17 
Spinal cord 146 
Decussation of the ..... 151 
Reflex action of 147 
Spinal nerves 130 
Spine 20 
Spleen . 80 
Starches 53 
their change into sugar ... 70 
Sternum 22 
Stimulants and narcotics . . . . 157 
Stomach 72 
Digestion 73 
Effects of alcohol upon ... 88 
Walls of 73 
Study, General plan of 8 
Sllgars 53 
Sunstroke 211 
Sutures 18 
Sweat-glands 131 
Sympathetic system of nerves . . 151 
Tarsal bones 27 
Taste, Organ of 172 
Sense of 171 
Tea 57 
Effect of 58 
Tear-duct 187 
Tears 187 
Teeth 66 
Temporary set of 67 
Permanent set of 67 
Bicuspids 68 
Canine 68 
Incisor 67 
Molar 68 
Care of 87 
Temperature of the body .... 121 
PAGE 
Red corpuscles of the blood ... 93 
Reflex action 148 
of the cord and brain .... 147 
Importance of 149 
Respiration 9, 109 
Change of blood in 116 
Movements of 114 
Object of 109 
Organs of 110,111 
Retina 182 
Ribs 22 
Movements of, in respiration . 114 
True, false, floating .... 22 
Sacrum 20 
Saliva . . . 69 
Mixing food with 69 
Salivary glands 69 
Salt, Importance of 55 
Scapula 24 
Schoolrooms, Ventilation of . . . 120 
Secretion 68 
Semicircular canals 177 
Sensation 169 
Sense of hearing 174 
of sight 180 
of smell 172 
of taste 171 
of touch 170 
Sense, Muscular 170 
Senses, Special 170 
Sewer system, Veins compared to . 101 
Sick-room, Hints for 218 
Sight, Sense of 180 
Skeleton 7, 9, 11 
Review analysis of 35 
Skin 9,125 
Scarf 125 
True 127 
Absorption from the . . 137, 138 
Care of the 133 
Practical points on 138 
Skull 16 
Skull and spine, how joined ... 22 INDEX. 
285 
PAGE 
Temporal bones 17 
Tendon of Achilles 28, 41 
Tendons 4° 
Theine 5^ 
Theobroma 5^ 
Thoracic duct 7$ 
Thorax 19 
Throat W9 
Care of the 200 
Thyroid cartilage 201 
Tibia 27 
Tissue defined 5 
Tobacco and its moderate use . . 160 
Effects of, upon young ... 162 
Excessive use of t6i 
Tongue 171 
Touch, Delicacy of 171 
Sense of 170 
Trachea no 
Trunk 19 
Bones in the 19 
Turbinated bones 18 
Tympanum of the ear 176 
Membrane of 175 
Ulna 25 
Valves of the heart 98 
of the veins 100 
Veins 100 
PAGE 
Veins compared to a sewer system . ioi 
Valves of ioc 
Ventilation 118 
of schoolrooms 120 
Ventricles of the heart 97 
Vertebrae 20 
Vestibule of the internal ear . . . 177 
Villi of the intestines 77 
Absorption by 77 
Vision, Mechanism of 183 
Vitreous humor 183 
Vocal cords no, 202 
Voice 202 
Organ of 201 
Quality of 203 
V omer 18 
Walk, How we 43 
Warm, Why the body is .... 120 
Waste matters, Getting rid of . . 192 
Principal 192 
Water 57 
White corpuscles of the blood . . 94 
Windpipe no 
Wisdom teeth 68 
Work and alcohol 62 
Work, waste, and repair .... 51 
Wrist 25 “What interests is remembered.” 
Horace Mann. 
YOUNG FOLKS’ 
HISTORY OF TOE UNITED STATES. 
By THOMAS WENTWORTH HIGGINSON. 
Small cpiarto, fully illustrated. Price $1.20. 
The distinctive character of the “ Young Folks’ History ” is, that it sets before the 
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Again, less than the usual space is devoted to the events of war, and more to the 
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The author does not consider it beneath the dignity of history to enliven his narra- 
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*** Copies furnished for examination to teachers on receipt of $r.oo. 
LEE AND SHEPARD, Publishers, 
No. io Milk Street, Boston. “A Great.Help to Teachers and a Blessing to the Children." 
LESSONS ON MANNERS. 
EDITH E. WIGGIN 
Price: cloth, 50 cents; school edition, boards, 30 cents, net. 
I. Manners in General. 
II. Manners at School. 
III. Manners on the Street. 
IV. Manners at Home. 
V. Manners toward the Aged. 
VI. Manners at the Table. 
LESSONS AND SUBJECTS. 
VII. Manners in Society. 
VIII. Manners at Church. 
IX. Manners at Places of Amusement. 
X. Manners in Stores. 
XI. Manners in Travelling. 
XII. Manners in Borrowing. 
Good manners, like good morals, are best taught by the teacher’s example; but 
definite lessons in which this most important subject can be considered in its appro- 
priate divisions, are of great value if we would have our children attain to “ that finest 
of the fine arts, a beautiful behavior.” Each lesson is preceded by a diagram for 
blackboard exercises; and the book, as a whole, is pronounced by our prominent 
educators complete in every particular. 
This little work is one which cannot fail to make an impression on such of its 
readers as indorse the old adage. 
Prolific in suggestion as to proper conduct in connection with the various matters 
of deportment upon which our boys and girls so frequently trip and fall, it is a mine of 
happy hints, useful alike in modelling youth in that most gracious of all attainments, 
a handsome behavior, and in aiding in rectifying the many errors in which one and all 
are so prone to entangle themselves. 
Easily comprehended words and concise sentences, enlivened by entertaining anec- 
dotes, lend a charm to the book that will find it hosts of eager readers among the little 
folks of the land; while much can be gleaned from it by their advisers, that will aid in 
shaping their course aright. 
It will be found especially valuable for use as a supplementary reader in the school- 
room, and we urgently recommend the book to the attention of all educators with this 
end in view. 
From George A. Walton, Agent Massachusetts State Board 0/ Education. — “The 
book [“ Lessons”] must prove a great help to teachers and a blessing to the children.” 
From Professor D. B. Hagar, Principal of State Normal School, Salem, Mass. — 
“ I am sure that the book in the hands of teachers cannot fail to be highly useful.” 
From Francis Cogswell, Superintendent of Schools, Cambridge, Mass.—“ It should 
be in every home, and on everylist of reading for schools.” 
From Thomas Tash, Superintendent of Schools, Portland, Me. — “ I shall recommend 
it at once for my own schools.” 
From A. J. Phipps, Superintendent of Schools, Lewiston, Me. — “ It is an interesting, 
practical work on a subject that should receive much more attention in schools, both public and 
private.” 
The book will be mailed to any address, for examination, upon receipt of the 
introductory price (25 cents) ; or, if wanted with a view to introduction, specimen 
copy will be sent free of charge, subject to return of same if not adopted. 
LEE AND SHEPARD, Publishers, 
No. xo Milk Street, Boston, Mass.