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Full text of "Physiology for beginners"

physiology 
begInners 



COLEMAN 



CORNELL UNIVERSITY. 
THE 

THE GIFT OF 

ROSWELL P. FLOWER 

FOR THE USE OF 

THE N. Y. STATE VETERINARY COLLEGE 

1897 



Cornell University Library 
QP 37.C69 

Physiology for beginners, 



3 1924 001 040 991 




Cornell University 
Library 



The original of tliis book is in 
tlie Cornell University Library. 

There are no known copyright restrictions in 
the United States on the use of the text. 



http://www.archive.org/details/cu31924001040991 



PHYSIOLOGY FOR BEGINNERS 



rt^^^ 



PHYSIOLOGY 



FOR BEGINNERS 



BY 
WALTER MOORE £OLEMAN, A.B. '/ 

AUTHOR OF " ELEMENTS OF PHYSIOLOGY," ETC. , 

LIB 
WITH AN APPENDIX ON NATURE STUDY 






'Nt'm gotfe 
THE MACMILLAN COMPANY 

LONDON: MACMILLAN & CO., Ltd. 
1903 

T 

Aii rights reserved 



COLEMAN'S PHYSIOLOGICAL SERIES. 

PHYSIOLOGY FOR BEGINNERS. For Interme- 
diate and Lower Grammar Grades. Illustrated with 
many half-tone engravings and figures. i8l pages. 

THE ELEMENTS OF PHYSIOLOGY. For an ex- 
tended course in Graded Schools and Rural Schools, 
and for a review course in High Schools, Academies, 
and Normal Schools. With 248 illustrations, including 
colored plates and manikin, xi + 358 pages. 



6^P 
37 



Mo. H(e' 
Copyright, 1963, 
By the macmillan company. 



Set up, electrotyped, and published July, 1903. 



_Fa-&^1. 



■ NortvdoJ Press 

y. S. Cushing & Co. — Berwick & Smith Co. 

Noriuood, Mass., U.S.A. 



TO THE TEACHER 

This book is taken up chiefly with inculcating 
practical truths concerning the health, most of the 
difiiculties of the important science of physiology 
being deferred for later study. 

Correct and practical ideas about health cannot 
be safely deferred, however ; for it is probable that 
the mistakes made in the physical life of fast-devel- 
oping children form one of the chief causes of 
failure of health in adult life. The cigarette habit 
alone warns us that boys should be taught at an 
early age reverence for their bodies. That girls 
should grow up with better ideas of taking care 
of themselves than they usually have, is shown 
by the widespread ill health existing among women. 
Dr. Cyrus Edson stated in the North American 
Review that he and a friend wrote out a list of four 
hundred and twenty ladies of their acquaintance 
in New York City, and that only twenty-seven of 
them possessed what could be called sound health. 
Lack of exercise and the wearing of deforming 
clothing are probably the chief causes of this de- 
plorable state of affairs ; the only hope of remedying 



6 TO THE TEACHER 

the evil is to instill correct ideas into the minds 
of girls of ten or twelve years of age before in- 
jurious habits of life are formed and before the 
rapid development of the adolescent period begins. 

Want of respect for the body is even more preva- 
lent among boys than among girls. In some com- 
munities half of the boys smoke cigarettes and 
weaken themselves for life. Teachers often find 
it best to supplement the instruction with a private 
talk with a boy who has begun this suicidal habit ; 
' not only for his own good, but because, owing to the 
popular indifference and -recklessness about health, 
the habit may spread from one boy to a whole private 
or public school. Prevention is a hundred times 
better and easier than cure. A private talk often 
convinces the boy of the teacher's personal and un- 
selfish interest in his welfare and prepares his mind 
to receive the instruction in class. 

The purpose in writing this book has been to 
bring the study of physiology near to the life of the 
community and especially to the life of the child; 
for no other study presents so good an opportunity 
to connect school and society. Nevertheless, it is 
hoped that every statement, even when made ap- 
parently in the most informal manner, will be found 
to have been as carefully weighed as if written for 
older minds. No attempt has been made to avoid 



TO THE TEACHER 7 

the warmth and friendliness of style that is natural 
in addressing the pupils for whom this book has 
been written ; neither has there been an attempt to 
use childish language, although the language is 
simple. 

The book contains innovations in method which 
it is unnecessary to discuss with professional teach- 
ers. The changes had their origin in those funda- 
mental principles of pedagogy which are universally 
accepted; as to the skill with which they have been 
carried out, it remains for the teacher and for use 
in the school to decide. The language used is 
as simple as that of fourth readers. While in- 
tended for recitation in the two grades next higher, 
it is believed that the book is likewise well adapted 
for use in the fourth school year as supplementary 
reading, accompanied by the oral instruction of the 
teacher. Thus it may supply work in three years 
of the graded school course. 

Work in elementary natural history is included 
in order that the book may in part supply a con- 
necting link between the nature study of the pri- 
mary grades and the biology of the Jiigh school, 
the author's " Elementary Physics " and his " Ele- 
ments of Physiology" (with the usual books in 
geography) completing the science work for the 
grades below the high school. 



CONTENTS 

CHAPTER PAGE 

I. The Skeleton ii 

II. The Brain and Nerves . .... 27 

III. The Breathing 41 

IV. Hygiene of the Lungs 54 

V. The Blood 67 

VL Hygiene of the Circulation 77 

VII. Food . 89 

VIII. Digestion ... 98 

IX. Stimulants and Narcotics in 

X. How we Move 118 

XI. The Covering of the Body 130 

XII. The Special Senses 147 

XIII. The Care of the Health 157 

APPENDIX. 

Nature Study 169 



PHYSIOLOGY FOR BEGINNERS 



CHAPTER I 

THE SKELETON 

A Beautiful House. — A man who wrote a book 
about the body called it " The House I Live In " ; 
another writer has called it " The House Beautiful." 
In these books the body was compared to a house, 
and parts of it were named from the parts of a 
house, as the framework, the pantry, the door, the 
hall, and- the windows. Can you tell your teacher 
what was meant by the door, the hall, and the 
other parts mentioned ? But who ever heard of a 
house that was alive and walked ! 

A Curious Custom. — In England sometimes poor 
people who are able to build only very small houses, 
go from village to village to work or to peddle, by 
placing their houses on wheels, and moving them 
with horses. Thus they travel around the country, 
eating and sleeping in their houses. Sometimes 
they have a little shop in one end of the house, 
where the man cobbles shoes or sells and mends 
tinware or gives Punch and Judy shows. Such a 
house is called a van. 

Van is a short word, but you may never have 



12 



PHYSIOLOGY FOR BEGINNERS 



19 



heard it because we have no such vans in America. 
The roads here are usually not so 
smooth and well paved as in Eng- 
land, and the towns are not so close 
together. 

Would you like to see a van 
moving along with the smoke 
going out through a little stove- 
pipe? 

Jolts and Jars. — Vans must 
have good strong frames, for they 
are more likely to fall to pieces 
than the house which remains in 
one place. So this wonderful 
house in which we live must be 
built well, for it moves quickly 
from place to place. It has a 
strong and perfect framework 
called the skeleton. 

The backbone, or spine, is the 
main pillar or column that sup- 
ports the building. Although 
called a bone, the backbone is not 
one bone, but a number of bones 
put one on top of the other, form- 
ing a tall pile. Between the bones 
are little pads of gristle, which are 
elastic, though not so elastic as 
rubber. They help to lessen the 
force of any shock or jar, just as 

the springs of a carriage lessen the jolting. 



.23 



Fig. I. — The Backbone, 
or Spinal Column. 

Can you count the bones 
in it ? Do you see the 
places for the pads of 
gristle 7 



THE SKELETON' 1 3 

The master of the house lives in a room called 
the skull, situated on top of the main pillar. It 
is not square, like most rooms, but round. If there 
were sharp corners, the walls would be more likely 
to be injured. The walls are firm and stout. The 
two windows through which the master looks are 
placed in front and high up in ihe wall, so that he 
can see a great distance. That these delicate win- 
dows may not be easily injured, the bones forming 
the brow, the nose, and the cheek stand forward 
around them. The nose, which tests the odors of 
things that come into this beautiful dwelling, is con- 
veniently placed just above the mouth, or doorway. 
Before you study much about this house, perhaps 
you will conclude that it is not only the most 
beautiful and convenient, but also the most wonder- 
ful house to be found in the whole world. 

There are only two more rooms in the house, and 
they are in the large part called the trunk. The 
two rooms, or cavities, are called the chest and the 
abdomen (ab-do'men). The chest contains a perfect 
pump called the heart, and a pair of large bellows, 
called the lungs, for bringing in fresh air and send- 
ing out impure air. The lungs and the heart are 
very delicate. They are protected by twenty-four flat 
ribs, which curve from the spine around the chest 
somewhat like the hoops of a barrel, and unite in 
front with the breast bone. The abdomen is just 
below the chest, and is separated from it by a fleshy 
partition. It contains the stomach, liver, intestines, 
and several other important organs. The organs are 



14 PHYSIOLOGY FOR BEGINNERS 

supported from beneath by two large bones called 
hip bones. These bones form a kind of basin 
(Fig. 5), the edge of which can be felt at the hips. 

The shoulder and arm are as well arranged as the 
rest of the body. In order that the arm may be 
held out from the trunk and have greater freedom 
of motion, it is not joined directly to the trunk, but 
to the shoulder. The shoulder blade is a broad, 
three-sided bone. At one end is a shallow cavity, 
into which the round head of the arm bone fits. 
The shoulder blade would not stand out alone from 
the trunk, so the collar bone acts as a brace to 
hold it in position. You can feel the collar bone 
above the chest like slender crossbeams running 
from the breast bone to the shoulder blades. Move 
the shoulder up and down. Does the collar bone 
move up and down } Put your right hand on your 
left shoulder. Does the shoulder blade move } The 
collar bone is sometimes broken by falling heavily 
on the shoulder. Boys who are reckless climbers 
have broken it in this way by falling from trees. 
After the collar bone is broken the shoulder falls 
forward, as there is nothing to keep it in position. 
A broken bone in a boy heals in about six weeks. 

A joint is a place where two bones are joined to- 
gether. There are several kinds of joints in the 
body, each allowing a different kind of motion. The 
shoulder joint is called a ball and socket joint be- 
cause the round end of the arm bone fits into a 
socket on the shoulder blade. At the shoulder 
joint you can move the arm up and down, backward 



THE SKELETON 



IS 



and forward, and in all. directions. A ball and 
socket joint allows motion in all directions. (Fig. 6.) 

The arm is divided into the upper arm, forearm, 
and hand. The upper arm has only one bone. (See 
Fig. 2.) The forearm has 
two bones. One of them 
turns around the other, thus 
allowing the hand to be 
turned over; this is a great 
convenience in using the 
hand. (Try turning the 
hand ; will it go all the way 
around, or only half around ?) 
To the forearm is joined the 
wrist, which is made up of 
eight little bones, shaped 
somewhat like blocks and 
fitted together like the 
bricks in the pavement. 
Since they glide over one 
another as the wrist bends, 
these joints are called glid- 
ing joints. See how smooth 
and curved the wrist is when 
it is bent. This is because 
there are several joints in- 
stead of one. (Fig. 7.) 

You see by the picture that the fingers appear to 
extend to the wrist. This is because the palm is 
made up of five bones shaped like those of the fin- 
gers. In the skeleton hand, the difference between 




Fig. 2. — The Skeleton. 



l6 PHYSIOLOGY FOR BEGINNERS 

the fingers and the palm is not noticeable. Which 
could you better afford to lose by accident, a thumb 
or a finger ? A thumb or two fingers ? Could you 
do more with the thumb and forefingerjthan you 
could do with all of the fingers without the thumb ? 
Why is the thumb so much more useful than any 
one of the fingers ? What kind of people talk with 
their fingers ? Did you ever hear of any one who 
could read with his fingers ? 

The legs have the same number of bones as the 
arms. There is no bone in the arm corresponding 
to the knee cap at the knee. There is, however, 
one bone less in the ankle than in the wrist, so the 
numbers are equal. The upper bone of the leg is 
called the thigh bone. It is the largest and strong- 
est bone in the body. It is so large and heavy that 
the warriors of savage tribes sometimes carry as 
weapons the thigh bones of slain enemies. The 
thigh bone joins the two bones of the lower leg at 
the knee. (See Fig. 2.) The knee cap is a flat, 
round bone that protects the knee joint from injury. 
If you straighten your leg and rest the foot upon 
the floor, you can move the knee cap with your 
hand. Can you move it from side to side or up and 
down? 

The two bones of the lower leg are the shin bone 
and the splint bone. The splint bone is very slender. 
The surface of the shin bone can be felt just under 
the skin. Can you feel it all the way from the knee 
to the ankle } 

The seven ankle bones are not so regular as those 



THE SKELETON 



^7 




Fig. 3. — A Vertebra. 

One of the bones of the 
spinal column. 



in the wrist, and one of them, the heel bone, is nearly 
as large as the other six together. The bones of 
the ball of the foot correspond to 
those of the palm, and the bones 
of the toes to those of the fingers. 
Which toe has only two joints ? 
The bones of the foot taken to- 
gether form an arch, so that the 
middle of the foot hardly rests 
upon the ground. Upon this firm 
but springy arch the weight of the 
whole body is thrown at every 
step, without shaking or jarring the other bones or 
the delicate organs. (Fig. 9.) 

The Joints. — The pieces in the framework of the 
van, or the little house on wheels, are fastened firmly 
together, so that not one piece of the framework 
can get out of place. Most of the parts in our 
skeletons, or framework, are joined together in such 
a way as to allow motion. Can 
you state what a joint is .? We 
have over two hundred bones in 
our frame. All the joints are 
movable except those in the hips 
and the skull. 

The Joints of the Skull. — The 
round bony case called the skull, 
which holds the delicate brain 
and protects it from injury, is made of eight bones 
beautifully fitted together. Look at the picture 
(Fig. 10), and you will see how the bones are put 




Fig. 4. — The Skull. 



PHYSIOLOGY FOR BEGINNERS 




together at the top of the head and how their edges 
are notched. They fit into one another like the 
notches at the corners of a chalk 
box, but the notches in the skull 
are not all of the same size and 
shape. The skeleton has immov- 
able joints where delicate organs 
are to be protected, and movable 
joints where motion is necessary. 
Which bone of the head is fas- 
tened by a movable joint ? Why 
are most of the joints immovable.? 
Try to pick up a pencil from the 
desk without bending a joint of the 

Fig. s.— The Bones of hands. YoU See hoW hclplcSS yOU 

would be were the joints immov- 
able. Joints that 
allow movement 
back and forth like 
a door are called hinged joints. Can 
you tell why they are called hinged 
joints.? A straight rounded ridge on 
the end of one bone fits into a groove 
in the end of the other. The elbow 
joint does not allow so free move- 
ment to the forearm as the shoulder 
joint allows to the whole arm. De- 
scribe the motion of the elbow joint. 
What joint in the leg is like it? 

The leg can swing outward at the hip as well 
as backward and forward. You learned when study- 



the Trunk. 

The upper room has ribs 
of bone in its walls. 
The lower room has 
walls of muscle. 




Fig. 6. — The Two 
Bones of the Shoul- 
der, and the Ball 
on the Bone of the 
Arm fitting into a 
Hollow in the 
Shoulder Blade. 



THE SKELETON' 



19 




ing the arm that a joint which, like the shoulder and 

hip, allows motion in all directions, is called a ball 

and socket joint. (See Fig. 6.) It 

allows motion in all directions because 

one bone has a round ball-like end 

which fits into a cuplike cavity, called 

a socket, in the other bone. Which 

joint allows freer motion, the shoulder 

joint or the hip joint .? Why are you 

glad that it is so ? The bones at the 

hip are separated, or dislocated as it Fig. 7. 

is called, less easily than the shoulder How many bones are 
, . , . . , , ^ . in each finger ? In 

jomt; this is because the socket is the skeleton of the 
deeoer *'^"'^' ^'^^ ^°^^ 

P * each finger appear 

Some joints allow motion somewhat ^° ^^"^ ^" ^='"'* 

. joint ? 

like a wheel turning on an axle or a 

top turning on its point. Such joints are called 
pivot joints. The forearm allows 
the hand to turn in this way. 
This is because one of the bones 
of the forearm turns over the 
other, its upper end being fas- 
tened at the elbow, the bone 
turning like a wheel on a pivot. 
There is only one more pivot 
joint in the frame besides those 
in the forearms. Can you find 
it.? 

You learned when studying 

the bones of the wrist that they glide over one 

another and form what are called gliding joints. 




Fig. 8.— The Hand of a 
Monkey, holding to a 
Limb. 

How does it differ from a 
man's hand ? 



20 



PHYSIOLOGY FOR BEGINNERS 




Fig. 9. — Bones of the Foot. 



Can you now name the four kinds of movable joints 
and give an example of each ? What kind of joint 
is found in the fingers ? Name the four ball and 

socket joints. What 
kind of joints do you 
think is most numerous 
in the body ? 

The joints of the spine 
are hard to classify. One 
bone does not move over 
another, as in the mov- 
able joints, yet as they allow a little motion, these 
joints cannot be called immovable. This motion is 
possible because the pads of gristle, or cartilage, 
between the bones can be squeezed together a little 
at one side and stretched a 
little at the other. If sitting 
or standing, you bend too 
far forward, the cartilages 
become V-shaped and the 
spine is rounded backward. 
If you write at too high a 
desk or always carry school- 
books and other things -in the 
same hand, the spine may, 
in time, become bent to one 
side. Such joints are some- 
times called mixed joints. 

You did not know that you are taller in the morn- 
ing than you are at night. The weight of the body 
during the day compresses the pads of cartilage in 




Fig. 10.— Top View of the Skull, 
showing Immovable Joints. 



THE SKELETON 21 

the spine ; but when you lie down during the night 
they regain their usual size. Early in the morning 
let some one tack a strip of wood to a post so that 
the strip just touches the top of your head. Stand 
under it again in the evening. Does your head still 
touch it? 

The ribs that join the breast bone are fastened 
by one cartilage, just as the bones of the spine are 
fastened to one another. (See Fig. 5.) 

The immovable joints (where are they found.?) 
have no cartilages in them. The mixed joints have 
one cartilage each. The movable joints have two 
cartilages, one on each bone, so that the surfaces of 
the bone do not rub together, but the smooth, white 
cartilages rub together instead. If the hard bones 
in the movable joints touched one another, a sud- 
den jar might break them. The layer of tough 
gristle or cartilage over the ends of the bones pre- 
vents this. Cartilage is not brittle like bones. 
Would you like to feel cartilage } Then you may 
feel your ear. It is all cartilage except the skin 
which covers it and the fat that is in the little lobe 
at the bottom. Is cartilage tough t Does it bend .? 
Is it elastic .? Is it hard or soft } Did you ever see 
the shiny white cartilage on the end of a fresh bone, 
as the bone of a fowl .? Dry bones have lost their 
cartilage. 

Something besides cartilage is necessary for a 
joint. Suppose you put two bones together that 
belong together. See how readily they fall apart. 
To keep the bones together, the joints are provided 



22 



PHYSIOLOGY FOR BEGINNERS 




Fig. 1 1. — The Topmost Ver- 
tebra showing the Two 
Sockets in which the Skull 
rests, and the Hole for the 
Peg of the Second Vertebra. 



with stout bands or cords called ligaments, which 
fasten the bones together. They are very strong. 
Children sometimes make the joints of the fingers 
crack. This should not be done, as the joints are 
weakened by stretching the liga- 
ments. The bones of the joints 
move noiselessly. This is be- 
cause there is in the joint a 
slimy liquid, like the white of 
an egg. Did you ever see this 
liquid when the joint of a fowl 
or .a soup bone was being dis- 
jointed in the kitchen ? One 
of the bands or ligaments is like a collar, and keeps 
this slimy fluid in the joint. The more you use the 
joint, the faster the liquid is formed, so there is 
always just as much as is needed. Did you ever 
hear of machinery that oiled itself.'' 
one should make you a present of 
a beautiful sewing machine or a 
bicycle. Would you not take great 
care of it? We should take even 
greater care of the perfect body 
given us, so that it may remain per- 
fect in form and grow strong and 
healthy. 

Are you becoming "round-shoul- 
dered " or flat-chested } If it takes you two years to 
become round-shouldered because of carelessness in 
sitting and standing, how long will it require with 
care for you to regain a correct shape } If you put 



Suppose some 




Fig. 12. — Second 
Vertebra showing 
the Peg for the 
Pivot Joint with 
the First Vertebra. 



THE SKELETON 



23 




poisons, like alcohol and tobacco, into the body, they 

will prevent the bones from growing to full size and 

becoming sound and strong. Do you know of any 

boys who have smoked cigarettes for. several years ? 

Are they as strong and large for their ages as 

other boys ? Are they rosy-cheeked and healthy ? 

Did you ever know a 

father who advised his 

son to use tobacco, 

even though he used 

it himself ? Fresh air 

and sunlight, work and 

play, are good for the 

bones. 

The rule for sitting : 
Sit as far back in the 
seat as you can. Never 
allow yourself to slide 
forward in the chair. 

The rule for standing : Head up, chin in, chest for- 
ward, hips back. This is also the right position for 
walking. 

A sprain means that a ligament has been stretched 
and partly torn, or that one of its ends has been 
torn partly or wholly from the bone. It is some- 
times more serious and harder to recover from than 
a broken bone. Rest and patience are needed while 
the parts are growing together again. Proper care 
of our bodies is always wise. Who more often have 
sprained ankles, boys or girls ? Who wear broader 
heels to their shoes '^. Who take more exercise .'' 



Fic. 13. — This boy was told by his teaclier 
tliat he was nearly a half inch lower at 
night than in the morning. He could 
hardly believe it, and he is tacking a 
strip so that it just touches the top of his 
sister's head. He maybe surprised when 
she stands under it again at night. 



24 



PHYSIOLOGY FOR BEGINNERS 



Compact 
>A or dense 
tissue 



A dislocation means that a bone is out of its 
place at the joint. The bones of the spine are some- 
times slightly dislocated when a 
rude or thoughtless child with- 
draws a chair from some one who 
is about to sit down. 

If a baseball bat is broken, you 
repair the break by wrapping wire 
around it. If a pitcher is broken, 
you may glue it together. But a 
broken bone heals itself if the broken 
ends are placed in proper position. 
It must be kept in place with 
splints until it heals. The healing 
usually takes five or six weeks, 
but the bone is weak for a still 
longer time ; a person with a broken 
bone should be careful for several 
months. After it is firmly healed 
it is so strong that the bone is just 
as likely to break again at another 
point as in the same place. If the 
wire is taken from the bat, the 
Fig. 14. — A Hollow picccs come apart, showing that 

Bone The femur, or ^j^^ brokcU picCCS haVC UOt United 
large bone of thigh, _ '■ 

showing two kinds of like a broken bone. 

l^^tr wthTnl The body is more wonderful and 

forms a ball and socket Convenient than any house. With 

joint ? A hinge joint ? . , . . , , - , 

proper care it repairs itself and 
keeps itself in order. The bone, in life, is covered 
with a tough coat through which blood vessels enter 




M *■ — ■ '^- 



THE HKKLETON 2$ 

and carry the blood that enabl.es the bone to repair 
itself. When bones of a drunkard or of a sickly 
person are broken, more time is required for them to 
unite than for those of a well or a temperate person. 

When a bone is healing, at the end of the first 
two weeks the new bone that is forming is only a 
kind of jelly. The harder part, called the mineral 
matter, is deposited later. 

Bones are composed of two kinds of matter, — 
the animal matter, which is like gelatine and glue, 
and the mineral matter, which is somewhat like lime- 
stone. Why cannot a bone be destroyed by burn- 
ing it.? Did you ever see a piece of bone which 
had been in a fire a long time ? Was it more or less 
brittle than before ? Was it lighter or heavier ? 

The bones are two thirds mineral and one third 
animal matter, or gelatine. The animal matter can 
be removed by boiling or by burning. The animal 
matter, gelatine, remains in the water after the bones 
are taken out ; the water and gelatine after cooling 
take the form of the vessel. Glue is made of 
gelatine. 

The mineral matter may be removed from a bone 
by soaking it in strong vinegar. Take a hog's rib 
or the leg of a fowl and soak it for three days in 
very strong vinegar. You can then tie the bone in 
a knot ! Your teacher may then wash the vinegar 
away and keep the bone in a bottle of glycerine, or in 
a bottle of alcohol and water. There is less mineral 
matter in young children's bones than in the bones 
of older people. Why should babies not be urged 



26 



PHYSIOLOGY FOR BEGINNERS 



to walk ? What deformity may result from walking 
too early ? 

Since the bones of older people contain less animal 
matter they are more brittle than the bones of chil- 
dren. Why should young people help old persons 
over rough places ? What is the use of each of the 
kinds of matter found in bones ? 




Fig. 



IS- 



Can you name each animal whose skeleton is shown above ? Has every one of 
these animals a backbone ? Shoulder blades ? One bone in first joint of limbs ? 
Two bones in second joint of limbs ? Which ones have finger bones and toe 
bones ? 



CHAPTER II 

THE BRAIN AND NERVES 

Questions you can hardly Answer. — " Why do you 
become hungry every few hours, eat food, and 
drink water ? What is food ? Why are some things 
'good to eat,' and others poisonous? What hap- 
pens to the food that you swallow? Why does 
a man become thin and weak if starved, or poorly 
fed ? How is it that your body is always warm 
not only in summer time, but on the coldest win- 
ter days ? Why do you feel hot when you run ? 
why do you then pant for breath and why does per- 
spiration make your skin quite wet? Why does 
your chest rise and fall about sixteen times a 
minute ? Why do you breathe in air and then 
' puff it out ' with the help of these movements ? 
Why do you choke if you grasp tightly the front 
of your neck with your hand and why does a man 
soon become choked if shut up in an air-tight box ? 
Of what is the blood, which you see whenever you 
cut yourself, composed ? What is the heart doing 
when you feel it beating against the left side of 
your chest ? What is the pulse which you can feel 
throbbing in your wrist ? How do the eyes see, the 
ears hear, the tongue taste, the nose smell, and 
the skin feel ? Lastly, how is it that you can move 

27 



28 PHYSIOLOGY FOR BEGINNERS 

the parts of your body, walk, run, and train your 
hands to skilled uses ? " 

The Science that Answers these Questions. — These 
were the questions put by a teacher of physi- 
ology in England to a class beginning the study. 
Arithmetic, grammar, and geography help us to 
answer many useful questions. Physiology helps 
us to answer questions like those above. I think 
you will agree that there is no more useful study 
than physiology. For, after studying it, you will 
probably be able to answer every one of the ques- 
tions, although you cannot answer one of them now. 

Physiology teaches us about ourselves, how we 
live, and how the parts of the body called organs, 
such as the bones, muscles, heart, and lungs, do their 
part in helping us to live. The special duty or work 
that each organ has to do is called its function. The 
science of health is called hygiene and it is founded 
upon physiology. In studying physiology and hy- 
giene, we are learning how to keep healthy and 
how to regain health if it has been lost. 

Many wonderful things also are learned in this 
study. Some of the most wonderful are about our 
moving and thinking. Suppose your teacher says 
"Fold your arms"; you know what to do because 
she told you. But suppose the teacher says, " You 
may each do something without my telling you." 
How many different things would be done! Who 
told John to put out his tongue, or Mary to nod her 
head ? No one. The thought of doing so came 
from their own brains and there the actions started. 



THE BRAIN AND NERVES 29 




Fig. 16. — The Brain, the Spinal Cord, the Nerves. 



30 



PHYSIOLOGY FOR BEGINNERS 



The Brain. — Can you describe a cow's brain, or a 
hog's brain, that you saw in the kitchen or at the 
meat market? What can you say about the color 
of the outside ? Of the deeper portions ? Was it 
smooth or uneven ? Strange to say, such brains look 
very much Ijke our brains, but they are not so large 
as ours. Some one has said that the many wrinkles 
and foldings of the outer gray part of a man's brain 
look like the kernel of a hickory nut or a walnut. 
The brain is the part of the body in which the 
mind works. It is here we think, and feel, and will. 

It is to the body what the 
general is to the army, or 
the mayor is to the city. 
The Chinese suppose that 
the soul is located in the 
stomach. We do not merely 
suppose, we know, from what 
men who study physiology 
have proved, that thinking 
and willing are carried on in the brain. But do not 
therefore conclude that there is no mystery about 
thinking and willing. There are many mysteries 
about our minds and our bodies ; we do not know 
what the mind is, or how it is connected with the 
brain. Physiologists have solved many questions, 
but there are many more that they, and all the other 
scientists, have failed to solve. 

How the Brain controls the Body. — Suppose you 
are asked to tap your foot on the floor and you do 
so. How is it that the brain causes the foot to 



,4 W^. • ^^-^•; 



Fig. 17. — A Well-developed 
Human Brain. 



THE BRAIN AND NERVES 3 1 

move although at some distance from it? The 
answer will be given you at once, lest you may 
think that this book has too many puzzling ques- 
tions. It has been found that there are small shiny 
white threads, called nerves, made of still finer threads, 
called nerve fibers, which connect the brain with 
every part of the body. The brain sends an impulse 
along the nerve fibers down to the muscles in the 
lower part of the leg. This impulse through the 
nerve fibers causes motion in the muscles, and thus 
the foot is moved and the toes tap upon the floor. 
The mayor of a town can send messages to the 
firemen, policemen, or scavengers in all parts of the 
town by means of the telephone wires. He can re- 
ceive messages likewise, and so can the brain. If 
any one steps on your toe, the news is carried to the 
brain, which superintends the body, by means of the 
nerves. Where these nerves leave the brain, most of 
them are together in a big bundle called the spinal 
cord. Did you ever see the marrow in the back bone 
of a hog ? That was the hog's spinal cord. How 
large was it.? A man's spinal cord is somewhat 
larger than a lead pencil. Smaller nerves branch 
from it and connect it with every part of the 
body. 

Questions to Think Out. — How do we know that 
a nerve goes to every tooth ? How can you know 
that a nerve goes to the root of every hair ? How 
can you know that there is no nerve in the hair ? 
How can you show that nerves go to two places on 
the skin only a hair's breadth apart ? 



32 PHYSIOLOGY FOR BEGINNERS 

The Two Kinds of Nerve Fibers. — The nerves carry- 
ing the impulses which set the muscles to working 
are called nerves of motion, or motor nerves. The 
nerves that bring impulses from the skin, eye, ear, or 
any part of the body and cause us to feel, are called 
nerves of feeling, or sensory nerves. No doubt you 
have had your foot "go to sleep." This was because 
you sat in such a position that the nerves were 
pressed upon and paralyzed for a time. The impulses 
could not pass and the foot could scarcely move or 
feel. If all the nerves had been interfered with, the 
foot would have been completely paralyzed for a time. 

How to find where the Sensory Nerves Abound. — 
Take a cork and thrust two pins into it so that the 
heads of the pins will be about one fourth of an inch 
apart. Blindfold a boy, or get him to turn his head 
and look in another direction. Find out if he can 
tell whether you touch the back of his hand with 
one pin head or with both. Try the finger tips next. 
Thus you can find which part of the skin has most 
nerve fibers. The place with the greatest number 
of nerve fibers gives the brain the most accurate 
report about the pins. On some parts of the skin 
the sensory nerves are so numerous that the two 
pins can be felt if only a small fraction of an inch 
apart. In other places they are felt as one pin un- 
less they are separated an inch or two. Test the 
sensitiveness of the wrist, the arm, the back of the 
neck and other parts with the cork and pins, mov- 
ing the pins farther apart when it is necessary to do 
so in order that they may be felt as two. 



THE BRAIN AND NERVES 33 

A Curious Experience. — Once a boy was careless in 
handling his gun and it discharged accidentally, shat- 
tering his right hand. The doctor had to amputate 
(cut off) the arm below the elbow. One day the boy's 
right hand itched, as he thought, and he reached 
over to scratch it with the other hand. He was 
startled for the moment by not finding it there. 
Crossing a footbridge one day he reached toward- 
the trunk of a tree as if to steady himself with his 
right arm, and fell into the water. You will soon 
learn how he came to make this mistake. After 
several years the ghostly hand stopped itching and 
he no longer thought of it as being on the arm. 

When a Finger itches, where is the Feeljng ? — It 
is natural for us to suppose that it is in the finger. 
But the incident of the boy who lost his hand shows 
that the itching seems to be in the finger even after 
it is destroyed. We therefore conclude that the 
itching never was in the finger, but in the brain. 
The mind thought of it as in the finger, because 
every time impulses came to the brain along certain 
nerves they were found to come from that finger. 
An infant has to learn such things gradually, and 
may burn his finger in the candle without knowing 
whether to move the hand or the foot to stop the 
pain. When the boy's hand was first cut off, any 
itching in the stump was, from habit, referred to the 
hand, until this habit of the mind was gradually 
overcome. Many old soldiers found that the scar 
made when an arm or leg was amputated, drew to- 
gether the skin too tightly in healing, and caused 



34 PHYSIOLOGY FOR BEGINNERS 

constant itching, seemingly in the foot or hand. 
The thing to do was not to dig up the buried leg 
or arm and place it in an easier position, as some 
people foolishly believed, but to make a slight gash 
and allow the scar, in healing a second time, to cover 
the part more loosely. 

The "funny bone" is so called because striking the 
nerve that passes over the bone at the elbow causes 
a tingling that seems to be in the fingers. Cross 
two fingers and touch the tip of the tongue with 
them. Why do there seem to be two tongues .? 
Because heretofore when these two points on the 
fingers were touched, we found that two objects 
located a short distance apart were touching 
them. 

Voluntary and Reflex Action. — Did you ever acci- 
dentally touch a hot stove, or other object, and find 
your hand jerking itself away vigorously without 
any effort of the will } Did you ever dodge or shut 
your eyes when you were trying to remain perfectly 
motionless ? Such acts carried on without any effort 
on your part are called reflex acts. Acts that are 
performed by an effort of the will are called vol- 
untary acts. In reflex action the impulse passes 
along the sensory nerve to small bodies in the 
spinal cord, called nerve cells, and comes back along 
the motor nerve to the muscles. Such acts are 
quickly performed, and many times save the body 
from injury when a voluntary act would take too 
long a time. Did you ever see any one kill a 
chicken.? What did you see to convince you that 



THE BRAIN AND NERVES 35 

reflex action could take place without the aid of the 
brain ? If the chicken stops jumping, how can you 
start it jumping again ? Why does this make it 
jump? 

In a copy of the following list, show to which 
class of acts each one belongs by writing R before 
reflex acts, R V before those which are either reflex 
or voluntary, and V before those which are vol- 
untary. 

winking hiccoughing smiling 

walking chewing jumping 

coughing vomiting the beating of 

dodging seeing the heart 

laughing throwing breathing 

talking swallowing blushing 

A Busy Brain and an Idle Brain. — You all know 
that the muscles grow strong and steady by using 
them properly. Likewise, the brain and nerves 
grow sound, vigorous, and active through use. The 
idle boy's brain will not grow strong as. does that 
of the wide-awake, thinking boy. If the brain is 
often confused by strong drink, the mind loses its 
clearness. If the hands are trembling and unsteady 
from smoking cigarettes, the nerves never have the 
strength they would have had if they had not been 
poisoned by the use of tobacco. 

Habit. — The brain and nerves can be trained not 
only for strength, but they can also be trained into 
good or bad habits. A habit is formed by doing a 
thing repeatedly in the same way. Suppose you al- 
low yourself to fret or worry, or whine when things go 



36 



PHYSIOLOGY FOR BEGINNERS 



Fig. i8. a Nerve Cell, 
A, and a fiber from it, B. 
The fiber has a white,fatty 
covering. A reflex action 
can take place with tvifo 
cells, each having a long 
branch, and connected by 
their short branches. 



wrong. When you grow to be a 
man or a woman, is it likely that 
you will be brave and cheerful 
when trials come, and patiently 
struggle until you triumph over 
them .? If you get angry fre- 
quently, will you be strong and 
self-controlled when you grow up, 
or will the habit . of losing your 
temper be likely to remain with 
you all your life ? You can even 
help to make yourself sick by 
worry ; you can help in getting 
well by being cheerful. 

Alcohol acts upon the little bodies 
called nerve cells, found chiefly in 
the spinal cord and brain. The 
cells shrink and shrivel to a smaller 
size. Some of the fibers that 
branch from the cells first swell 
up, then become knotty and waste 
away. It is no wonder that the 
drunkard acts like a crazy man 
and is sick at the end of his 
spree. Neither is it surprising 
that he loses his strength and 
industry and shortens his life. It 
was formerly supposed that the 
changes in the nerve cells and 
fibers resulted from the contin- 
ued use of alcohol. Men have 



THE BRAIN AND NERVES 37 

found by examining a rabbit's brain, after com- 
pelling it to take alcohol, that this condition occurs 
the first time alcohol is used. Although the brain 
may almost recover from one poisoning by alcohol, 
it will never entirely recover. It is not wise to drink 
alcohol even once, if we care for the health of the 
delicate substance of the brain. Alcohol, by injur- 
ing the brain, weakens the mind to such an extent 
that insanity may result. The fighting and the 
base crimes committed by drunkards prove that they 
are temporarily insane. 

Rest and Sleep. — Idleness and excitement weaken 
the brain, but regular work strengthens it. After 
using the brain, we must allow it to rest. Sleep is 
the time when tired nerves, brain, and muscles rest. 
Children need more sleep than grown persons be- 
cause they are growing and are so very active while 
awake. A child who is weak or sickly in body, but 
active in mind, should be taken out of school and 
allowed to work and play out of doors most of the 
time. Fresh air and exercise increase strength 
and health. Some parents allow weak children 
to study too hard in order to get ahead of children 
of their own age. This often results in vain 
and foolish as well as sickly children. A healthy 
child should study more than a sickly one. 

How do Rest and Sleep help the Brain ? — Sleep 
gives the blood time to repair the waste of the body. 
You will soon study about the blood and learn how 
it does its work. You will learn that it flows 
through blood vessels to all parts of the body. 



38 PHYSIOLOGY FOR BEGINNERS 

carrying the food which has been prepared by di- 
gestion and the oxygen which is obtained from the 
air in the lungs. At the same time that the blood 
takes nourishment to the organs, it carries away the 
used-up materials, the waste matter. This expla- 
nation gives the reason why sleep is so refreshing. 

AN INDIAN STORY 

Once upon a time there was an Indian who went 
on a long journey to get flints with which to make 
arrow heads. The country of the Flint Rocks was 
many, many hundreds of miles from his own country. 

After getting the flints, he started home. His 
supply of parched corn and smoked venison failed 
when he had many days' journey before him; so 
with his tomahawk he dug up roots of plants for 
food and traveled on. But the roots were so poor 
a food that he became very weak and hungry. He 
began to chew the leaves also. By the side of the 
trail he found growing a tall weed that bore large, 
fleshy leaves. He plucked several of the leaves and 
ate them, but they had a burning and bitter taste. 

Soon he felt so faint and sick that he staggered 
as he walked, and sinking down at the foot of a 
large tree, he murmured to himself that he would 
never see his squaw or his papooses again. He 
tried to rise but fainted away. 

Meanwhile, the warriors of the tribe, thinking he 
had been long on the journey, started out and found 
him under the tree. They gave him food and carried 
him to his wigwam. 



THE BRAIN AND NERVES 39 

When he recovered, he told the medicine man of 
the tribe that he beHeved it was eating the plant with 
the fleshy leaves and bitter taste that had made him 
give way on the journey. He showed him the plant 
and the medicine man ate some. It made him sick 
too. So the medicine man said to himself, there 
must be some great charm or power in the plant. 
The Great Spirit has given it a bitter taste and sick- 
ening effect in order to keep man from eating it and 
gaining this power. So he dried it and chewed a 
little day by day, and found that it ceased to make 
him sick. He grew fond of the plant ; it made him 
feel so dull and dreamy that no trouble gave him 
any uneasiness. The young warriors all learned to 
chew it. After a while the medicine man found that 
if he ceased chewing the weed, he felt miserable and 
uneasy without any cause. He grew so weak with 
age before his time that he could not follow the war 
path but had to stay at home with the squaws to 
take care of the camp. He told the young warriors 
that the plant had weakened him, but that he could 
not do without it because it had mastered him. But 
they would not believe that a weed could hurt them. 

When the pale faces came to America from across 
the sea the Indians told them of the plant that gave 
strength, as they believed. The white men also began 
to use it. They knew no more about the Great Spirit 
than the Indian, and they thought that the Great 
Spirit made good things and hid them from men by 
bitter tastes. In this they were greatly mistaken. 
God has made the good things pleasant to the taste, 



40 



PHYSIOLOGY FOR BEGINNERS 



and the poisonous things repulsive to the taste, in 
order to keep man from eating them and injuring 
himself. But man is headstrong and wise in his 
own conceit and thinks he knows better. 

The white men as well as the Indians also learned 
to smoke this weed. Can you tell the name of the 
weed } 




Fig. 19. — The Tobacco Plant. 



CHAPTER III 

THE BREATHING 

We breathe all the time, awake or asleep, but the 
breathing usually goes on so quietly that we do not 
notice it. Hold one hand near the nose and place 
the other on the chest. When the air comes out of 
the nose, what happens to the chest wall } What 
happens to it when the air goes in.? Find out in 
the same way what happens to the waist and to the 
abdomen. As the body walls move outward by 
the action of the muscles, the size of the chest in- 
creases and the air rushes in to fill the empty space. 
When the walls move inward, the air is driven out 
again. 

The chest measure is the distance around the 
chest. Get the tape measure from your mother's 
sewing basket and find your chest measure. The 
difference between the size of the chest fully ex- 
panded and contracted as much as possible is called 
the chest expansion ; and the difference in the 
measurement of the waist expanded and contracted 
is called the waist expansion. (See Fig. 20.) Would 
you like to know your waist expansion? Your 
chest expansion ? By standing before a mirror you 
can find your own chest expansion. Read the tape 
measure when the chest is contracted and let the 

41 



42 



FHYSIOLOGY FOR BEGINNERS 



measure slip through your fingers until the chest is 
fully expanded, then read it again. Subtract the 
first number from the second ; the remainder is 
your chest expansion. Which boy and girl in the 
class have the greatest expansions 'i 



Name of PiipiL . 


Waist 


Chest 


Measurement when expanded 






Measurement when contracted 






Difference between measurements, or 
waist expansion and chest expansion 







Sometimes boys make the muscles on their arms 
swell and harden to see who is the strongest. 

A better way to test 
strength is to measure 
the size and expansive 
power of the chest. 
The boy with the great- 
est chest expansion is 
able to run faster and 
longer without becom- 
ing tired. He can 
hold out longer in any 
kind of work or ex- 
ercise, and can sing, 
speak, and think bet- 
ter. He feels stronger 
and better than a 



\ 

1 




i 



Fig. 20. — This little girl is finding how 
much her chest expands. She is using 
a tape measure l)erure a mirror. 



boy with smaller chest expansion. 



THE BREATHING 



43 



Respiration is another name for breathing. It 
consists of an inspiration and an expiration. In an 
inspiration the air rushes into the lungs ; in an 
expiration it is driven out again. 

How the Muscles enlarge the Chest. — During 
inspiration the chest moves upward and outward. 
This movement is made by the muscles lifting the 
ribs. If you are not fleshy, you can, with the fin- 
gers, feel the ribs move up and out during an inspi- 
ration, and down 
and back during 
an expiration. 

But the hollow 
cavity of the chest 
also enlarges 
downwards. This 
result is due to 
another muscle, 
the broadest and 
flattest in the 
body, called the 
diaphragm (di'a- 
fram). The dia- 
phragm forms the floor of the chest and divides 
it from the abdomen, the lower part of the 
trunk. The diaphragm is hollowed upward like a 
bowl turned over. By contracting, it flattens and 
forces down the organs into the abdomen, increas- 
ing the space above. At the same time the abdo- 
men expands or swells out a little in front and at 
the sides to make room for the organs forced down 




Fig. 21. — The Lungs and Heart. The dia- 
phragm is shown separating the chest above 
from the abdomen below. 



44 



PHYSIOLOGY FOR BEGINNERS 



by the diaphragm. Draw a deep breath and find 
out whether the abdomen enlarges or diminishes 

during an inspiration, — 
during expiration. 

Where do you feel the 
muscles contract when 
you cough "i When you 
laugh ? Those you feel 
are the muscles in the 
walls of the abdomen 
contracting and forcing 
the stomach and liver up 
against the diaphragm. 
Does the breath go in 
or out in coughing and 
laughing ? 

Why we Breathe. — 
Perhaps you do not 
know why we- breathe. 
Fig. 22. — Showing portions of the We breathe for the pur- 

windpipe""^"' '"°""' *'°''' '"'' P°S^ of *^^^"g i"tO the 

body the part of pure air 
called oxygen and for 
the purpose of. sending 
the impure air out of 

the lungs. The oxygen makes the blood bright 

red although it may have become dark owing to 

the impurities contained in it. 

We can breathe through either the nose or the 

mouth, but it is better to breathe through the nose. 

There are hairs in the nose which catch the dust 




u, spinal column ; b, gullet ; c, windpipe 
(lower part) ; d, windpipe (larynx) ; 
e, epiglottis ; / soft palate and uvula ; 
k, tongue ; /, hard palate. 



THE BREATHING 4S 

and keep it from going into the lungs. When the 
weather is cold, breathe through the open mouth and 
notice whether you can feel the cold air in the throat. 
By taking the air through narrow passages, the nose 
warms the air before it reaches the delicate organs. 
The air goes from the nose to the throat, where a 
little trap door made of gristle covers the entrance 
to the windpipe. When this door is lifted, the air 
enters the windpipe. 

The upper end of the windpipe is a kind of box 
(the larynx) made of gristle, called " Adam's apple." 
You can easily feel it in your throat. When you 
swallow, this organ moves upward, bringing its 
upper end under the root of the tongue. This aids 
the trap door, or lid, in preventing food and drink 
from going into the windpipe. Across, the gristly 
box, below the lid, two elastic strips are stretched. 
These strips are called the vocal cords. As the 
breath coming from the lungs passes through the 
opening between these cords it causes them to 
vibrate, thus producing the voice if the cords are 
close together and drawn tightly. Feel the wind- 
pipe below the " Adam's apple." Is it smooth or 
in ridges ? It is made of rings of gristle, which keep 
the windpipe open so that we may not choke or 
smother if anything presses on it. 

The Lungs. — About four inches below the throat 
the windpipe begins to branch, looking like a tree 
turned upside down. It first divides into two tubes, 
and these in turn divide into still smaller tubes, 
called bronchial tubes. This branching occurs a 



46 PHYSIOLOGY FOR BEG/Arj\rEJiS 

number of times and the smallest tubes end in 
a number of little air cells. These cells are round 
and are arranged on the ends of the air tubes like 
bunches of grapes. In these cells the true function of 
breathing is performed. The walls of the cells are as 
thin as tissue paper. Into the tiny blood vessels 
between the cells part of the fresh air, called oxygen, 
passes and is carried along by the blood. At the 
same time some of the impurities in the blood pass 
through the thin walls into the air cells and are 
carried out in the breath. All these tubes and 
cells taken together form the lungs. The lungs 
are so light when partly full of air that they float if 
thrown into water. The many tubes brought to view 
when the lungs are cut give them the appearance 
of a sponge ; but the tubes are arranged in a more 
orderly manner than those in a sponge. 

Why we Breathe. — Do you know what the lungs 
are for ? Can you tell why we breathe ? You say 
to supply the blood with oxygen and take away the 
impurities. But why is it necessary to supply 
oxygen.? What are the impurities that are taken 
away ? If you will try the easy experiments given 
below, and think carefully about what you read, you 
will have no trouble in understanding the work of 
oxygen. Its work is most important, for without it 
we could not live. No one knows what life is, but 
we do know that the process called oxidation is at 
the basis of life. 

Below are some experiments which will teach you 
what is meant by oxidation. 



THE BREATHING 



47 



Experiments. — Get a large glass jar, a short 
candle, and some matches. Light the candle and 
put it on the table, near the edge, covering it with 
the glass jar. The flame slowly smothers and goes 
out. Why is this ? Is the air now in the jar differ- 
ent from that which was in it before the candle was 




'f^ ''l*WS' 




Fig. 23. — Breathing into 
a jar through a tube 
or hollow stem, passed 
through a card. What 
happens to a lighted 
candle inserted into the 
jar? Explain this. 



Fig. 24. — The bottle has 
been inverted on the 
table, the card slipped 
away, and the lighted 
candle lifted into the 
bottle to see whether 
it will still burn. 



lighted .? Some change must have taken place or 
the candle would continue to burn. Do you think 
the candle will ever burn again under the jar with- 
out changing the air? Let us try an experiment. 
Slide the jar to the edge of the table and let the 
candle drop out. Light the candle and slip it up 
into the jar again, the jar being held with its mouth 
a little over the edge of the table to receive the 
candle. (Fig. 24.) The flame goes out at once. 



48 PHYSIOLOGY FOR BEGINNERS 

Evidently the air in the jar is not the same as the 
air outside. Take up the jar and wave it to and 
fro a few times, so as to change the air. The 
candle now burns in it again with a bright flame 
as at first. So we conclude that the candle will 
not continue to burn unless there is a constant 
supply of fresh air. 

Carbon Dioxid (di-ox'id). — If you should pour some 
clear lime water into the bottle after the flame goes 
out, the lime water would become white and milky. 
This shows that there is a new gas in the bottle. 
This gas (carbon dioxid) is formed by the union 
of the oxygen of the air with the carbon in the 
tallow. The oxygen of the air in the bottle is used 
up in forming the carbon dioxid, so the candle does 
not burn. Oxygen, therefore, is the gas which makes 
it possible for a fire to burn. The union of oxygen 
and other gases is accompanied by heat, and some- 
times by light ; it is called oxidation. Carbon dioxid 
is a gas that prevents anything from burning ; this 
gas smothers fire. Here we come to the important 
point. The fresh air going to the lungs carries 
oxygen with it, but the air we breathe out has much 
carbon dioxid and very little oxygen. 

Another Easy Experiment. — Let me tell you how 
to prove that our breath is as impure as the air 
that smothered the candle. Place a cardboard over 
the mouth of a bottle containing pure air. Take a 
long straw, the hollow stem of a weed, or a sheet of 
stiff paper rolled into a tube, and pass the tube into 
the bottle through a hole in the cardboard.- Now 



THE BREATHING 49 

breathe into the bottle through the tube several 
times, drawing the air from the bottle back into the 
lungs each time. (Fig. 23.) Place the bottle on the 
table as in the former experiment, afterward with- 
drawing the cardboard. Move the bottle to the 
edge of the table and pass the lighted candle up 
into it. Does the flame go out as quickly as in 
the former experiment.? If you breathe through 
a tube into clear lime water, the water turns milky. 
What does this prove .'' 

Sometimes carbon dioxid is found in wells. It is 
then called choke damp. If a lighted candle lowered 
into a well continues to burn, it is safe for a man to 
go down into the well. Air that is so impure as 
to put out a candle would soon smother a man. 

Oxidation in the Body. — The air which we breathe 
out has much carbon dioxid and very little oxygen, 
because carbon dioxid is constantly forming in the 
body of a human being as well as in the flame of a 
lighted candle. The food we eat corresponds to 
the tallow in the candle; the air furnishes the oxy- 
gen for the candle flame and for the human body. 
Oxidation gives- rise to heat and motion. If the 
oxidation is rapid, as in running, the heat is com- 
paratively great. The oxidation in the body is 
much slower and at a lower temperature than the 
oxidation in the candle flame. The colder the 
weather the more food we use to keep up the heat 
of the body. 

Charcoal is almost pure carbon. Nearly all foods 
contain some carbon. That there is carbon in sugar 



50 PHYSIOLOGY FOR BEGINNERS 

can be shown by putting sugar on a hot stove or 
a hot shovel. The water in the sugar is driven off, 
and the black charcoal remains. Corn turns black 
when it burns, and so does bread if it is left in the 
oven too long. If this bread had been eaten before 
it was charred, it would have been oxidized in the 
body by the oxygen brought in by the lungs. Part 
of it would have formed carbon dioxid and would 
have been exhaled. For some reason we cannot 
eat and digest pure charcoal as found in charred 

sugar or bread. 

When you are older and 
study chemistry you will learn 
about many other substances 
besides carbon and oxygen. 
You will learn that although 
one fifth of pure air is the 
active gas called oxygen. 

Fig. 25. — Breathing through about four flfths of it is an 
lime water. . , . n 1 •■ 

inactive gas called nitrogen. 
Nitrogen does not readily unite with other elements. 
If you hold a piece of cold glass above the candle 
flame, or if you notice a lamp chimney when the 
lamp is lighted and before the glass has had time to 
become hot, you will see moisture collecting on the 
glass. This has been formed by the union of the 
oxygen of the air with the hydrogen that was in 
the tallow or oil. Hence water, a liquid, is made 
up of these two gases. Water is thus formed by 
the oxidation of hydrogen in our own bodies. 
Some of the water that forms a " cloud on . the 




TliE BREATHING 5 1 

breath " on a cold morning, or the water that 
collects when you breathe upon a cold window 
pane, is formed in the body in that way. 

Oxidation, the union of oxygen with other sub- 
stances, may take place rapidly and cause great heat, 
as when a log burns : it may also take place slowly, 
as when wood rots ; but even then it is accompanied 
by a little heat, and sometimes by light, as you may 
have noticed. (You probably called it "fox fire.") 
When iron oxidizes, rust is formed. Rusting is 
oxidation. The oxidation that keeps up the heat 
and strength and life of the body is of the slower 
kind. In the moist body, oxidation takes place 
slowly. 

A Comparison. — Do you know of anything besides 
an animal that is warm and moves? It needs a 
continual supply of fresh air and fuel in order to 
move. If the supply gives out, it becomes cold and 
motionless. Likewise, it uses only the active oxy- 
gen of the air, not the lazy nitrogen, and fuel takes 
the place of man's food. No doubt the boys can 

tell what it is. It is called a 1 . It differs 

from an animal in many ways, the chief difference 
being that an animal can control his actions. It 
needs to be controlled when it is moving. 

Review Questions. — Where is the organ located 
that controls all parts of man's body ? What is a 
nerve ? a nerve fiber ? Is breathing voluntary or 
involuntary, or may it be either.? What is a reflex 
action ? What is a voluntary action .? Where is 
the spinal cord } How can you prove that feeling 



52 PHYSIOLOGY FOR BEGINNERS 

is not in the fingers ? What is the effect of alco- 
hol upon the nerve cells ? upon the nerve fibers ? 
upon the mind ? How is a habit formed ? 

A SHIP IN A STORM — ITS IGNORANT CAPTAIN 

" There was once an emigrant ship that sailed 
from Liverpool. The men and women and children 
on board were going to leave England to work in a 
strange land. One night a dreadful storm arose. 
The ship tossed about so much that the captain 
ordered the sailors to send all the men and women 
and children down into a large room under the deck, 
because he was afraid they might be in the way. 
The sailors fastened the doors so that they could 
not get out. The storm went down in a few hours, 
when the captain told the sailors they might open 
the doors, or hatches, as they were called. The sail- 
ors took a candle, because the room where these 
poor creatures were put was quite dark. When 
they entered, the candle went out. They lighted it 
again, and it went out a second time. This was 
done several times. At last it remained alight, and 
so they were able to descend. And what do you 
think they found ? Nearly all the men, women, and 
little children lying on the floor — some of them 
dead, others unconscious. The only air they had 
had to breathe was the air that had come out of 
their mouths. And as that was not fresh air, it had 
poisoned them. 

" This is a sad story, but it taught a great lesson, 
for no one now puts either people or animals into 



THE BREATHING 53 

rooms where fresh air cannot get in; though few 
people, even among those who know something of 
physiology, are quite as particular about methods of 
getting fresh, clean air into their houses as they 
should be. 

" It was because the air was dirty, or poisonous, 
that the people shut up in the ship died, for our 
bodies need all the oxygen that is in the air. Each 
time any of these poor people took in a breath, 
more of the wholesome oxygen was used up ; each 
time any of them breathed out a breath, more of the 
poisonous carbon dioxid was in the room ; and the 
absence of the oxygen and the presence of the car- 
bon dioxid was what caused some to die, and others 
to become unconscious."^ 

1 " Health in the House," by Mrs. Buckton. 



CHAPTER IV 

HYGIENE OF THE LUNGS 

How the Lungs are injured by Alcohol. — We may 
smell alcohol in the breath soon after it has been 
swallowed. This is because the alcohol has made 
its way into the blood and the lungs are doing their 
best to remove it. The alcohol in wine, beer, and 
whisky hardens and thickens the walls of the deli- 
cate air cells so that they cannot do their work well. 
The oxygen and carbon dioxid cannot be exchanged 
so rapidly through the thickened walls of the air 
cells. Alcohol also weakens the blood vessels in the 
lungs, so that they readily swell and become the steat 
of inflammation, such as pneumonia and bronchitis. 
(An old drinker sometimes breathes and speaks with 
a wheezy or hoarse sound because of the hardening 
of the air cells and the injury to the vocal cords.) 

Doctors formerly thought that alcohol was a cure 
for consumption. It is now known that it does not 
afford any relief to one suffering with consumption. 
The injury that alcohol does the lungs sometimes 
brings on an incurable form of the disease. 

Tobacco and the Lungs. — If the walls of the tubes 
and air cells of a man's lungs could be flattened and 
placed side by side, they would cover a surface equal 
to the walls, floor, and ceiling of a small room. 

54 



HYGIENE OF THE LUNGS 55 

Smoke from a pipe or cigar is not usually inhaled 
because the poison is too strong. Most of the 
smoke would be coughed up before it went farther 
than the windpipe. If a man or boy smokes cigar- 
ettes, the weaker smoke can be drawn into the 
lungs, or "inhaled," as it is called. Which does the 
greater harm, weak cigarette smoke in the large and 
tender lungs, or strong tobacco smoke in the tougher 
mouth .? Instead of having strong, well-developed 
lungs, cigarette smokers often grow up with weak 
and flattened chests ; severe pains in the chest fre- 
quently result. The habit of smoking cigarettes 
often grows on some people so that they smoke 
a hundred a day. Such smokers are sometimes 
killed by the habit in a few years. 

A boy named James B in a certain town died 

from the effects of cigarette smoking, the habit 
being so strong that he smoked them on his death- 
bed. The day after his funeral, two boys went into 
a store to buy cigarettes, and asked the salesman to 
give them the same kind of cigarettes that killed 

Jimmie B . Were these two boys brave boys 

or simpletons .? 

A smoker may be offensive to others because of the 
disagreeable odor from his clothing and the dis- 
agreeable manner in which some who smoke indulge 
in the habit. They force all who sit or pass near 
to submit to a sickening odor. They do not take 
the trouble to remove the odor that the tobacco 
leaves upon their clothing and bodies, if indeed 
it could be removed at once. They spit upon 



56 PHYSIOLOGY FOR BEGINNERS 

the floors of cars, stations, courthouses, and hotels. 
Too frequently a man with a vile pipe or cigar sits 
SO" that the wind carries the odor of the tobacco 
to others who have been wise enough not to form 
the habit. In Mexico people smoke even in the 
theaters. 

The body is the' dwelling place of the soul, and 
no one has a right to injure even his own body. 

It is a public danger to have people carrying fire 
about and dropping lighted matches and cigar stubs. 
Millions of dollars' worth of property has been de- 
stroyed as a result of this habit. 

Thought Questions. — Answer the following ques- 
tions, remembering that the oxygen of pure air, after 
it enters the body, burns the food and thus keeps 
the body warm. It gives us strength with which to 
move and think and work. 

Touch the iron frame of the desk. Feel your 
neck beneath the collar. Which is warmer.? 
What causes this difference } 

Why does staying out in the fresh air give a 
good appetite ? Why does it make us still more 
hungry if the air is cold as well as pure ? Why do 
we eat more in winter than in summer .? Why does 
living in close, unventilated rooms cause a person to 
lose his appetite ? Why do you get hot when you 
exercise ? Why should babies carried in the arms 
be clothed more warmly than older children .? 

Why should you breathe deeply ? Which causes 
you to breathe more deeply, moderate or violent 
exercise.? Which causes you to expand the lungs 



HYGIENE OF THE LUNGS 



57 



more, running or walking? Which develops the 
lungs more ? 

Why should a person who faints in a crowded 
house be carried into the open air to recover ? 

How can you put out a fire in the stove with- 
out using water? How can you tell by the touch 
that an animal is dead ? 

Have you noticed that you can learn a lesson 
better after recess than before ? Is a headache ever 
cured by going out into the 
fresh air? 

Developing the Lungs. — If a 
person does not have healthful 
outdoor occupation, it is well to 
form the habit of taking deep 
breaths in the open air for a few 
minutes twice each day. Throw 
the windows wide open ; stand 
with head erect and chest up; 
draw in just as much air as possi- 
ble, allowing the walls of the chest 
and abdomen to expand. After a few seconds allow 
the breath to escape slowly, until the lungs are emp- 
tied. Keep up this deep breathing for five minutes. 
If one were to do this every day, his lungs would 
become so large and strong, and his blood so pure,, 
that he would have no need to fear lung diseases. 
Such a person would seldom have a bad cold. 

How does breathing purify the blood ? How do 
large lungs and deep breathing keep the blood 
purer than small lungs and shallow breathing? 




Fig. 26 



58 PHYSIOLOGY FOR BEGINNERS 

How the Plants help us. — The carbon dioxid 
from our breathing and from the fires in our houses 
and factories is absorbed by the plants through 
tiny openings on the under side of their leaves, and 
the carbon is used to build up the plant. In turn, 
the plants, by the aid of the sunshine, send out the 
oxygen for man and animals to breathe. We 
should encourage the planting of 
trees and should take care of those 
that are growing, even of the com- 
monest kind. The trees protect 
us from the heat of the sun in 
summer and catch much of the 
dust that, but for them, would be 
blown into our houses. 

Other Impurities besides Carbon 
„,^ . , Dioxid. — What is called dust is 

Fig. 27. — A man's sus- 
penders should slide on vcry iujurious to the lungs, so 

thaChenotstuVe: «^^ch SO thatthe luUgS of pCOple 

is raised, the suspender who Hvc in citics have a grayish 

on that side may be- ... 1 -i 1 1 t . ., 

come longer as the tmt, whllc pCOplc wh© llVC lU the 

other one becomes country have pink luugs. Dust 
consists of particles worn from 
stone, hair (from carpets), meat, cotton, wood, wall- 
paper, etc. Even the cleanest room, when kept 
closed for a number of days, has a close, unpleasant 
smell, which should be removed by a thorough air- 
ing before the room is used. Sometimes the houses 
in cities where poor people live are so tall and 
crowded that the fresh air and sunlight hardly reach 
the rooms to purify them. Cleanliness is more im- 




HYGIENE OF THE LUNGS 59 

portant there than in more comfortable houses. 
But often we find houses of people who are not 
poor, where the sunlight and fresh air are kept out 
of the rooms by dark curtains which catch and 
make more dust. Such people fear that the sunlight 
will fade the paper and carpets. They are often 
pale and unhealthy, and have such weak nerves that 
they easily lose their tempers, and make themselves 
and others unhappy. 

What Unhealthful Homes lead to. — These persons 
are also likely to lose their appetites for healthful, un- 
stimulating food, and to wish food highly seasoned, or 
to crave even stronger stimulants. People who live 
in unhealthful homes, whether rich or poor, are often 
downhearted, and many of them, for this reason, 
fall into the habit of drinking liquors to "drown 
their sorrows," as they think. " But alas! they may 
drown their souls, instead." 

To live in houses that are dark and dusty or 
filled with bad air, is to destroy our appetites, 
strength, and healthful appearance. The health and 
happiness of one child is of more value than any 
number of carpets and curtains. No intelligent 
mother should allow her pride in fine things to cause 
her to put carpets into a bedroom or to use dust- 
catching curtains there instead of simple window 
shades. No room should be re-papered unless the 
old paper is first removed. 

Notice the millions of particles of dust playing in 
the sunbeams that enter a dusty room. Go to the 
window and with a mirror send a beam of sun- 



6o PHYSIOLOGY FOR BEGINNERS 

light across the room in search of dust in the air. 
The lungs of a coal miner wfere found, after his 
death, to be as black as coal itself. Another man 
coughed up coal dust seven years after he stopped 
working in the mines. 

Impurities from the Body Itself. — But the impu- 
rities coming from the breath and skin of a human 
being are often more injurious than the dust from 
furniture. Would you like to try an experiment with 
your own breath ? You know that carbon dioxid is 
a colorless, odorless gas. Breathe several times into 
a bottle and quickly cork it up air-tight. After a few 
days remove the cork and smell the air in the bottle ! 
The odor arises not from carbon dioxid, but from parti- 
cles from the digestive organs, nose, lungs, or teeth, 
that pass off in the breath, and have decayed in the 
bottle. Impure air in churches and schoolhouses 
causes headaches, sleepiness, and dullness. 

Ventilation. — Some persons think that if a bed- 
room is aired once a day the air in it will be pure; 
but this is not enough. While any one remains 
in it, whether in the daytime or at night, the air is 
all the time being made impure ; hence the air 
should be changing all the time. The air of a 
closed schoolroom becomes very impure and un- 
healthful in ten minutes. 

To prevent a draft, a board as long as the width 
of the window may be put on its edge under the 
lower sash after slightly raising the latter, the board 
filling up the opening. The air will come in be- 
tween the two sashes and be turned upward. 



HYGIENE OF THE LUNGS 6l 

Another way to prevent drafts, and the easiest 
way, is to open the window only a fraction of an 
inch. The draft cannot be felt more than a foot or 
two from the window. Some people who have 
never tried very small openings in a window, think all 
small openings make drafts that " cut like a knife." If 
the people who are so fond of raising windows high 
and chilling every one would hold a hand to a small 
opening in cold weather, and remember that the open- 
ing is many times as large as the combined size of 
all the nostrils in the room, and that the air enters the 
opening more briskly than it is inhaled, they would 
see that there is enough ventilation. Sometimes 
one eighth of an inch is enough, if the weather is 
very cold, and there are only two or three people 
in the room. Air always enters an opening more 
rapidly in cold weather because there is a greater 
difference between the temperature outside and in 
the room. Why do we need more oxygen in cold 
weather than in warm weather.? The force with 
which air enters an opening can be felt with the 
hand, or shown by dangling a thread before the 
opening. 

The Black Hole of Calcutta. — Did you ever read 
the story of " The Black Hole of Calcutta " .? In 
the year 1756, a cruel tyrant in India, having cap- 
tured in war a hundred and forty-six Englishmen, 
forced them one hot night into a room with only 
two small windows, each about two feet square. 
Then he closed and barred the door. The prison- 
ers soon began to suffocate, and to struggle and 



62 PHYSIOLOGY FOR BEGINNERS 

fight for places near the windows. When at last 
the terrible night was over and the door was opened, 
only twenty-three were found alive. Most of these 
were in a crazed condition, and only a few of them 
ever regained their health. 

How to ventilate a Room. — Ventilation should fur- 
nish air having two qualities : it must be pure and 
of the right temperature, neither too warm nor too 
cold. As you learned when studying about the 
wind in geography, cold air is heavier and settles, 
thus causing the warm air to rise. Its weight 
causes it to spread out and to displace the warm air. 
On this account, the coldest air in a room is near 
the floor, and there is usually cool air in the room 
moving along the floor toward the stove or fire- 
place. Because of this current along the floor, some 
people take cold if they wear slippers. Since the 
cold air goes from the opening to the stove, it is 
best to place the stove near a window and let the 
air enter through the window. The air should come 
in on the side of the house against which the wind 
generally blows in the coldest weather. The stove 
should be on that side. If the stove is near the 
inlet, the air is heated as soon as it enters. The 
outlet for the air should be on the side of the room 
opposite the stove, so that the warm, pure air must 
cross the room and give warmth and oxygen to the 
occupants before passing out. How can you ascer- 
tain whether the air is coming in or going out .? If a 
window near the stove is opened at the top, the hot 
air, as it rises, passes out at once, and the warm air 



HYGIENE OF THE LUNGS 63 

does not circulate through the room. Some persons 
have mistaken ideas about opening windows at the 
top. The wisdom of ventilating in this way depends 
on the circumstances. 

Ventilation and Sleep. — Many mothers have 
doubtless learned that when children are restless 
in their sleep, throw off the coverings and toss 
about, it is often because the air in the room has 
become impure with carbon dioxid. The nerve 
centers are poisoned, causing a struggle for fresh 
air. A window is opened, and one falls into a sweet, 
sound sleep. On rising in the morning, the bed- 
clothes should not be spread neatly over the bed at 
once, but they should be first thoroughly ventilated 
in the open air. Beds should always be well aired. 

Correct Breathing. — You have learned that you 
must take long, deep breaths; also that you must 
breathe through the nose. If you sit or walk with 
the chest flattened, you do not get enough pure 
air, even if the room is perfectly ventilated or if you 
are out of doors. You have learned two reasons why 
you should not breathe through the mouth but only 
through the nose. The nose warms the air before 
it reaches the delicate lungs. The hairs in the nose 
catch the dust and prevent it from going into the 
lungs. There are other reasons. Breathing through 
the nose prevents short, shallow breaths. If, when 
running, you breathe only through the nose, you 
can run twice as far before getting tired. If 
you run, or take other hard exercise with the mouth 
open, you will soon be panting and gasping for 



64 PHYSIOLOGY FOR BEGINNERS 

breath. Breathing with the mouth open develops a 
weak and unpleasant expression of the face. So — 

" If you wish to grow healthy, wealthy, and wise, 
Shut your mouth and open your eyes." 



THE ARCHITECT AND HIS TWO FRIENDS 

AN ALLEGORY 

Once in the city of New York there lived a great 
architect. This architect had two friends who ad- 
mired him for his wonderful wisdom and the great- 
ness of his works. Both of the friends lived in 
houses which had been built for them by this archi- 
tect. They found the houses to be most gracefully 
built and to possess a convenience of arrangement 
that was perfect. 

One of them thought, however, that the founda- 
tion of his house was a trifle large in front, and built 
too straight in the rear, and it is said that he forced 
the pillars in front closer together, and slipped bits 
of leather or other flimsy stuff under the rear, and 
made it gracefully tapering and, as he thought, not 
at all top-heavy. The house showed great wisdom in 
its construction; but he thought the hall was a little 
too spacious, compared with the other parts, and 
that it allowed too much room for the movements of 
his family, and too much chance for strong drafts of 
air. So by means of metal stays and cables of stout 
fiber he drew in the walls of the hall, and in his 
opinion gave it a size that was proper for such a 
house. 



tiYUiKNE OF THE LUNGS 65 

He knew that the builder of the house was not 
only an architect of perfect skill but likewise of per- 
fect taste, yet the material in the wall was not of the 
exact tint that the owner desired, so he painted it, 
and obscured the delicate natural tint of the wall. 
He hung heavy curtains upon the most delicate 
parts, overlooking the strong brackets and other 
parts more suited to the purpose. 

He loved the house, for it was his home, and he 
loved the architect, who was his friend ; but he al- 
"lowed dirt and dust to accumulate around the door, 
where it would be blown in upon the finely finished 
interior. He even used the pantry as if it were a 
warehouse or storehouse and not a pantry. He was 
afraid the architect would not know how he appre- 
ciated the beautiful dwelling, nor know how wise he 
believed him to be ; so he went sometimes as often 
as once a week to the house of his friend and told 
him what a great architect he was and how perfect 
was every work of his hand. In fact, his voice could 
be heard leading the chorus of praise and gratitude. 

The other friend was also grateful for his beauti- 
ful home, and likewise believed in the wisdom of the 
architect. He let the foundation stay as it was. 
He liked the roomy hall and said that it gave free- 
dom and pleasure to all the family. The architect 
often passed that way and often visited him in his 
house ; and when the architect saw that the house 
was well preserved, and clean not only on the outer 
wall but in every passageway and pantry, and every 
proportion kept as originally planned, he saw that 



66 PHYSIOLOGY FOR BEGINNERS 

the faith and gratitude of his friend were not hypoc- 
risy. But whenever he saw a house, whether on 
broadway or street or avenue, that had been altered, 
or improvements attempted, according to the notions 
of certain foolish people, he knew that the owner 
believed more in such people than in him. 

The name of the first friend was Fop, and the 
name of his wife was Style. The other friend's name 
was Truth. 

This allegory is intended to teach reverence for 
the body as a work of God. What is meant by 
changing the foundation.? By making the hall 
narrow ? By misusing the pantry ? Were Mr. Fop 
and his wife hypocrites or did they deceive them- 
selves } 



CHAPTER V 

THE BLOOD 

You learned in the last chapter that part of the 
food is burned in the body like fuel in a stove. 
You were no doubt surprised and some of you may 
have asked yourselves the questions, " Is it worth 
while to put food into the body to have it de- 
stroyed? How can it burn in my body? There 
is no fire in my body ! " You soon learned that 
it is not an ordinary fire. The bodily heat of 98 
degrees, as shown 
by the thermom- 
eter, is one proof Fig. 28. — Thermometer for testing temperature 
, 1 , • 1 . ■ • of body by placing it under the arm or in the 

that oxidation is mouth. 

going on in our 

bodies. In the depth of winter, in the icy regions 

near the north pole, when the thermometer is 40 

degrees below zero and the mercury itself freezes in 

the thermometer, man's heat is still 98 degrees, on 

account of this internal oxidation. 

Where in the body does this oxidation take place ? 
It was once thought that the materials in the blood 
were burned up by the oxygen while the blood was 
passing through the lungs. Now it is known that 
the combustion goes on in the different organs to 
which oxygen is carried by the blood. Were all the 
heat of the body furnished by the lungs, the tem- 

67 



68 PHYSIOLOGY FOR BEGINNERS 

perature would be far too great for that organ. 

The fact is that the blood is warmer on entering 

the lungs than on leaving them. 

If you cut the skin slightly, the blood flows out 

in drops ; if the cut is large and deep, it flows 

in a stream. Why does 
the blood flow from a 
wound.? If your hand is 
cut, the blood still comes 
out, even though you 
hold your arm above your 
head. Does it simply leak 
out of the cut, or is it 
pushed out ? By placing 
your hand upon your chest, 
a little to the left of the 
middle line, you can feel 
the beating of the heart. 

Fig. 29. — The Heart. t-i 1 , i i-i 

Ihe heart works like a 
force pump, and the beating is evidence of the work 
it does in forcing the blood through the body. The 
beating of the heart forces the blood to. flow from a 
wound or cut. 

The heart is in the chest, between the lungs. It 
is a pump and is composed of muscle. It is shaped 
like a strawberry. Would you like to know its size ? 
Close your hand and look at your fist ; this is about 
the size of your heart. But why are not candy 
hearts and the pictures of hearts on valentines 
shaped like a strawberry? On the heart, near the 
top, there is a shallow groove filled with fat. This 




THE BLOOD 



69 




yellow fat forms a notch in the outline of the red 
flesh or muscle. The first pictures of the heart 
were drawn to show only the red 
part of its surface. Thus the cus- 
tom arose. 

Lay the forefinger lightly upon 
the cheek, just in front of the ear, 
and feel the throbbing of the pulse. 
The throbbing may be felt also in 
the neck, and in the wrist back of 
the thumb. One beat of the heart 

, . ,1 C-- ^1 Fig. 30. — These fig- 

occurs betore each pulse, bmce the ures show the reia- 

heart is a pump, it forces on the blood "^^, .^'^^^ °^ ^ *,* 

^ y ' _ ventricles of a dog s 

at each stroke. You have noticed heart contracted 
similar action while pumping water. ^""^ expanded. 
This pumping of the heart makes the pulse which you 
feel. The blood is not held in the body like water 
in a sponge, but it is in tubes called 
blood vessels. Blood vessels are 
found in every part of the body. 
The tubes which carry the blood 
from the heart are called arteries ; 
the tubes which bring it back 
are called veins. The very small 
blood vessels which carry the blood 
from the arteries to the veins are 

Fig. 31. — Diagram of 

the Heart, showing its Called capiUaties. Ihe capillaries 
are very tiny tubes which, by con- 
necting the arteries with the veins, 

enable the blood to circulate through the body. 

Wherever you stick a pin into the skin, you reach 




Chambers and Blood 
Vessels. 



70 



PHYSIOLOGY FOR BEGINNERS 



one of these tiny tubes. Notice how the blood flows 
when you prick the skin with a pin. Blushing is 
caused by the filling up of the capillaries.- 

The blood has many important functions. On 
its way through the lungs the blood receives oxygen 
from the air in the air cells, and 
gives up carbon dioxid. In the 
digestive organs it takes up 
food. It carries oxygen and 
food to all the organs and tis- 
sues, each taking what is needed. 
From all the organs and tissues 
it carries the carbon dioxid 
and other waste substances. 
Through the lungs and kidneys 
and skin, it passes off waste 
material. Lastly, the blood, as 
it circulates, distributes to all 
parts of the body the heat pro- 
duced by the activity of the muscles and glands. 
Of these two kinds of organs you will learn more 
later. Briefly, it may be said that the blood has 
two functions : to take nourishment to all parts of 
the body and to take away the waste material. 

The appearance of the blood under the microscope 
differs from its appearance when seen with the 
unaided eye. You have all seen blood and know 
that it is red and thicker than water. Under the 
microscope it does not appear to be a red liquid at 
all, but a watery looking fluid, with many little 
white and colored corpuscles floating in it. The 




w 

Fig. 32. — Diagram of a Net- 
work of Capillaries. A, 
artery, B, vein. 



THE BLOOD 



71 



blood appears red, just as water in a pan, with many 
red cranberries or strawberries floating in it, looks 
red. 

The parts of the blood are really three in number. 
First, there is the thin watery part composed of 
water and of the 
food which is eaten. 
The nutritious 
parts of the food 
are taken up by 
the capillaries in 
the walls of the 
stomach and intes- 
tines, and carried 
into the veins. 

Second, there 
are the corpuscles, 
so flat and round, 
known as the red 
corpuscles. Al- 
though looking at 
them singly, under ^'°- 33- 
the microscope, 
they are yellowish in color, they appear red when 
many are seen together. Each one of them carries 
a load of oxygen gas from the lungs to the organs, 
as boats carry coal down the river. The corpuscles 
lose their bright color when they give up their oxy- 
gen to the brain and other organs. The blood now 
appears dark and purplish in color until the corpus- 
cles get another load of oxygen in the lungs. 




-The General Distribution of the 
Blood Vessels. 



72 



PHYSIOLOGY FOR BEGINNERS 



Lastly, there are the white corpuscles, which are 
like policemen. They arrest any harmful germs or 
particles that get into the blood. Instead of put- 
ting them into jail, they de- 
vour and thus destroy them. 
The white corpuscles are 
much larger than the red 
ones, though the red ones 
far exceed the white ones in 
number. If a splinter gets 
into the skin a number 
of white corpuscles gather 
around the splinter and 
keep it from doing further 
injury to the body. After 
a while they cause the place 
to fester, and succeed in 
pushing the splinter out. 
Perhaps you have noticed a 
whitish appearance around 
a splinter or sore. 
It has been stated that the heart pumps the blood 
in two directions ; from the heart to all parts of the 
body, and from the heart to the lungs to be purified. 
One pump cannot send two streams of water in dif- 
ferent directions. The heart really is a double 
pump. The left side of the heart is one pump, 
moving pure blood ; the right side is another pump, 
moving the impure blood. Each pump has two 
chambers. (This makes how many chambers all 
together in the heart T) The upper chambers of the 




Fig. 34. — Blood Corpuscles as 
seen under a Microscope. 

r, red corpuscles, lying flat ; r' , red 
corpuscles, on edge; r" , red cor- 
puscles, gathered in rows ; p and 
g^ white corpuscles. 



THE BLOOD 



73 




pump are called auricles; they receive the blood. 
The blood passes from the upper chambers to the 
lower chambers, which are called ventricles. The 
latter force the blood out of the heart. 

You are now prepared to 
give a complete account of 
the circulation of the blood, 
starting at some point in 
its course, and naming the 
organs in order through 
which . it passes until it 
reaches the same point 
again. Let us begin with 
the impure blood as it enters 
the heart, coming from the 
body through two large veins, 
and entering the right auri- 
cle. The auricle contracts (remember that the heart 
is a hollow muscle) and sends the blood into the right 
ventricle below it. Next, the right ventricle con- 
tracts ; at the same time a valve composed of three 
flaps closes up against the opening between the right 
auricle and the right ventricle, so that the blood 
cannot go back into the auricle, but is sent through 
the pulmonary artery to the lungs. After passing 
through the capillaries of the lungs and exchang- 
ing carbon dioxid for oxygen, the blood comes back 
to the heart by four veins and enters the left auricle. 
By the contraction of the auricle it goes into the 
left ventricle, passing through a valve of two flaps. 
The ventricle contracts, the flaps of the valve being 



Fig. 35. — The Chambers and 
Valves of the Heart. 



74 PHYSIOLOGY FOR BEGIMNERS 

closed against the opening between the auricle and 
ventricle by the blood which would otherwise rush 
back to the auricle, and forces the blood out through 
one large artery, which soon subdivides into smaller 
ones. The smaller arteries carry the blood to all 
parts of the body. It passes through the various 
organs in very small tubes, much smaller than a 
hair, called capillaries. Through the thin-walled 
capillaries the blood gives to' each organ the special 
substances needed for its particular work (like an 
expressman delivering packages in a city). It 
takes up carbon dioxid and other waste materials. 
The capillaries then unite to form tiny veins. These 
unite to form larger ones, till at last they form 
two great veins which bring the blood back to the 
right auricle again. Thus you see why the move- 
ment of the blood is called its circulation ; it goes 
over the same path again and again, making a circuit 
each time, as if it were going around in a circle. 

STORY OF A BLOOD CELL, OR THE FAIRY'S BOAT RIDE 

Did you ever hear of a fairy ? One evening after 
a teacher went home from school, he fell half asleep 
and a very strange story came into his mind. He 
imagined he was a little fairy that lived under the 
water and went riding in a little red boat called a 
blood cell. 

The boat was floating in a stream, called the 
blood, which flowed in the body of a boy who was 
not very large, though he seemed a giant to the 



THE BLOOD 75 

little water fairy. There were thousands of other 
tiny red boats in every small drop, so that the blood 
appeared red. The boat floated on until it came to 
the stomach, through the walls of which food, made 
from the eggs, bread, and milk the boy had eaten 
for breakfast, came into the stream. The boats 
went floating on, and came to a large place with four 
rooms, called the heart. So many came in that the 
heart was soon filled. 

The fairy had been wondering what caused the 
stream on which this boat was floating without row- 
ing to flow so fast. He now found out, for the heart 
gave the boats a hard squeeze, and sent them in a 
great hurry to the lungs. It was a delightful place 
in the lungs. The air the boy was breathing took 
away the impurities of the blood and gave a load of 
oxygen. The cells, which had been dark red, at 
once became bright red, and his boat, or cell, looked 
as strong and good as new. After the boat passed 
through the small tubes of the lungs it floated back 
to the left side of the heart. 

The heart again gave a hard squeeze, and sent 
the boats out with a merry bound through a big 
blood-tube called an artery. This tube soon branched 
into two, and the fairy's boat whirled (for it was as 
round as a tub) into the branch going toward the 
boy's feet. As it went toward the surface of his 
body, it came to a wonderful maze, or tangle of wind- 
ing passages. These passages, or capillaries, were 
all very small ; the little fairy thought his boat would 
never get through. The boats moved very slowly. 



y6 PHYSIOLOGY FOR BEGINNERS 

one after another. The bones and the muscles and 
the skin were very hungry and unloaded the boats 
of their cargoes of food and oxygen, and loaded them 
down with carbon dioxid and other impurities. 
At first the muscles were weak because they were 
loaded down with waste matter ; now they became 
strong and active again. The fairy saw some boats 
lodged in the tiny tubes, looking very dark, for the 
boy had been lazy and his muscles did not move 
enough to help the heart push all the boats along. 
Every time the heart beat, the boat received a little 
shove. It got through at last and came out into a 
loose, baggy pipe called a vein. It floated slowly 
back, first to the right side of the heart, then to the 
lungs, to exchange its load of waste matter for oxy- 
gen, then to the left side of the heart. When it left 
the heart again it took the fairy through a tube lead- 
ing to the brain. The brain was busy thinking and 
studying. The oxygen which the boats brought 
made the boy's mind active, so that he could learn 
his lessons readily. As the boats were going back 
through his cheek, a big mosquito drew this fairy 
boat and many others into his long sucking tube. 
The boy slapped the mosquito and broke his suck- 
ing tube. The little fairy escaped, but he never 
heard what became of his poor boat. 

Be ready to write, or to tell your teacher, the story. 
Tell where the fairy boat went, and what happened 
to it in the stomach, luiigs, heart, maze of winding 
channels, and brain. 



CHAPTER VI 

HYGIENE OF THE CIRCULATION 

Does your face ever flush, even though you are 
not blushing, or sitting by a fire ? When you are 
older and study an advanced book in physiology, 
you will find out how muscular exercise affects the 
circulation. The glow and warmth resulting from 
active play and work are more beneficial to the body 
than the warmth which comes from a fire. The 
heart is stimulated by exercise. 

People who sit at their work all day long find 
that their circulation becomes sluggish because the 
brain and other organs do not get enough pure 
blood. Such people feel dull, lose their appetites, 
and become low spirited. Some of them take alco- 
hol or other drugs to stimulate the circulation. What 
they really need is to take exercise. This makes 
deep breathing necessary and causes the heart to beat 
more rapidly. It does this without poisoning the 
body by alcohol and other drugs. Boys should not 
run, or girls jump the rope, long enough to injure the 
heart by making it do too much work. By running 
or exercising a little longer each day, the heart 
becomes so strong that it does not readily begin to 
thump when much effort is put forth. 

A very cool bath, followed by vigorous rubbing, 

77 



78 



PHYSIOLOGY FOR BEGINNERS 





promotes the circulation better than poisonous 
stimulants. 

It is more dangerous to cut an artery than a vein. 
This is because the walls of the veins are thin and 
flabby, so that when cut they have a tendency 
to fall together and close the opening. There is 
little danger from a cut vein unless it be one of 
the large veins of the neck, armpit, or thigh. On 
the contrary, the walls of the arteries are stiff and 

tough and do not 

readily close up, 

even if pinched 

together. The 

cut end often has 

to be tied to keep 

it closed. 

The heart is 

pumping blood 

into the arteries at 

This action forces 
the blood out of a cut artery in jets 
rather than in a steady stream. 

If the blood comes in a slow, steady stream, we 
may know that a vein has been cut; if it comes 
in jets, an artery. Why is there this difference ? 
What makes the pulse beat? Why is there no pulse 
in the veins ? Which do you think should pass 
along close to the bones, deep below the surface — 
your veins or your arteries ? Why ? The arteries 
are the ones that are so located and they are there- 
fore less likely to be injured than the veins. 



Fig. 36. — Showing the 
Valves in the Veins open 
to allow blood to go to 
the heart and closed to 
prevent a backward flow. 

every contraction. 




Fig. 37. — Show- 
ing How the 
Blood Clots after 
it coagulates. 
The clot is 
shrunken and 
floating in the 
watery part. 



HYGIENE OF THE CIRCULATION 79 

Bleeding from a severe wound may be stopped 
by tying around the limb close to the wound a 
handkerchief, towel, or anything at hand suitable 
for a bandage. Put a stick under the bandage, 
twisting it round and round, so as to hold the band- 
age tight and cause the knot to press upon the 
blood vessel. If an artery has been cut, the pres- 
sure must be applied on the artery between the 
wound and the heart. Why ? If a vein has been 
cut, the pressure must be applied on the side of the 
wound away from the heart. Give the reasons for 
this, remembering that the blood flows from the 
heart to the arteries, from the arteries to the capil- 
laries, from the capillaries to veins, and from the 
veins to the heart. 

When blood is exposed to the air, it thickens or 
coagulates, and the coagulated blood, by filling up 
the cut, stops the flow. The thickening is caused 
by little strings that form in the watery portion of 
the blood and entangle the corpuscles. Blood 
thickens more quickly if the cut is bathed in hot 
water; bathing the cut in cold water retards the 
thickening. 

The heart like the other muscles must rest ; it 
does rest after each beat. These many little pauses 
or rests amount to about eight or nine hours during 
twenty-four hours. You breathe about twenty times 
in a minute, and your heart beats about four times 
as fast as you breathe, — about eighty times a minute. 
The hearts of grown persons do not beat so 
rapidly. 



80 PHYSIOLOGY FOR BEGINNERS 

A Boy with Presence of Mind. — Mrs. Barnett 
gives the following account of a brave boy who 
saved his sister's life by using his wits and the little 
physiology that he had learned : 

The boy was about twelve and his sister some 
three years younger. They were out playing in a 
hayfield. The sun shone, the sky was blue, and 
soft fleecy clouds floated overhead. 

While the haymakers went to eat their dinner 
under the shady hedge at the other end of the 
sixteen-acre field, the boy took up the scythe to try 
his hand at mowing. Two or three strokes went 
well, but at the fourth effort the scythe slipped over 
the grass instead of through it, and Mary having 
come too near in her eagerness to watch his prow- 
ess, received the stroke of the sharp instrument on 
her leg, just above the ankle. 

In a moment she fell with a scream, the blood 
pouring out all over boot, stocking, and frock as she 
lay on the ground. 

What would you have done ? Run screaming 
across the hot field to fetch the haymakers ? If you 
had, Mary would have been dead before you came 
back. This her brother knew. 

" Don't scream, Mary," he said. " It will be all right." 

Fortunately he remembered about the blood in 
the arteries heing red -and that in the veins being 
blue, or dull purple red. 

Mary's was red ; there was no doubt of that ; red 
as red could be, as it came out in little jerks and 
made almost a puddle by its quantity. 



HYGIENE OF THE CIRCULATION 8 1 

Off came Jim's necktie and round the leg he 
bound it, near the wound, but on the heart side 
of it. Being a boy, he could tie a knot, and so the 
necktie was tied tight, and the blood stopped flow- 
ing, and Mary was saved. Then he hallooed and 
shouted till the haymakers heard and came and car- 
ried the child home, where she lay in bed till the 
parts that had been cut — the muscles and the artery 
— had joined together again, and in the meantime 
the blood had to go by other ways and use more 
and other capillaries to take it back to the veins. 

Everybody was pleased with Jim for saving 
Mary's life, and Jim himself was not a little proud, 
I can tell you, though sometimes he gave his teacher 
credit for teaching him what to do. 

Effect of Alcohol upon the Heart. — The nervous 
system controls the heart. There are two sets of 
nerves which exercise this control ; one set of nerves 
increases the heart beats and the other decreases 
them. If the heart beats either too rapidly or too 
slowly, it can be regulated. The nerves that diminish 
the heart action may be compared to the balance 
wheel of a watch which keeps the spring from " run- 
ning down " all at once. They may be compared also 
to the brake on the wheel of a wagon. Disconnect 
the balance wheel and the watch ticks wonderfully 
fast for a time ; if the brake is taken off, the wagon 
dashes down the hill at a rapid rate. Alcohol af- 
fects the heart by acting chiefly upon this last set 
of nerves which serve as a " brake." When these 
nerves are deadened, the heart beats more rapidly. 



82^ 



PHYSIOLOGY FOR BECmNERS 



Hence, the so-called stimulating effect of alcohol 
is really a deadening effect upon the nerves. A nar- 
cotic is something that deadens the nerves or stupe- 
fies the brain. Alcohol is therefore called a narcotic. 
The rapid beating of the heart shortens the rests 




Fig. 38. — The Circulation through the Heart and Lungs. 
The shading denotes impure blood. Begin at 11 with the blood com- 
ing from the body and follow the arrows with ' a pencil and see 
whether the pencil comes out at 10. The blood will have gone 
twice through the heart and once through the lungs, and at 10 is 
returning to the body. 

and tends to weaken the organ, frequently resulting 
in a diseased condition. Although stimulating and 
injuring his heart by drinking alcohol, the drinker 
gains no advantage in the end. The heart soon 
becomes tired and beats more feebly than before the 
alcohol was drunk. 

Alcohol and the Blood Vessels. — There are nerves 
in the walls of the veins and arteries which cause 
them to expand or contract just enough to keep 



HYGIENE OF THE CIRCULATION 83 

the necessary amount of blood flowing through 
them. But if one drinks beer, wine, cider, brandy, 
whisky, or any other alcoholic drink, these nerves 
are at once deadened and allow the vessels to 
expand more than they should. The flushed face, 
or the red, blotched nose of the drinker, shows the 
effect of this deadening of the nerves. 

Effects of Alcohol upon the Blood. — Alcohol in- 
jures the red corpuscles of the blood. Why does 
this affect the supply of oxygen in the body.? 
Alcohol also injures the white corpuscles and 
lessens their power of protection against disease 
germs. In the South, where the dreadful disease 
of yellow fever formerly raged, drunkards were 
among the first to be attacked and among the 
first to die. The experience has been similar in the 
case of other contagious diseases. 

The "Tobacco Heart." — Tobacco also is a nar- 
cotic. The beat of the heart is quickened, but 
the strength of the beat is lessened. Excessive 
smokers are often afflicted by severe pains in the 
region of the heart. The tobacco heart, from 
which tobacco users often suffer, is caused by the 
irregular action of the heart (beating either too 
rapidly or too slowly). Have you ever noticed how 
your heart thumps when you are startled .? This 
thumping is called palpitation. The " tobacco 
heart " is either palpitating or beating too feebly. 
Many volunteers wishing to join the army in the 
late war with Spain were rejected because they 
were suffering from the " tobacco heart. " 



84 PHYSIOLOGY FOR BEGINNERS 

Review Question. — Why does the effect of alcohol 
upon the heart resemble the effect of removing the 
brake from a wagon, not that of adding strength to 
the horses. 

Thought Questions. — Does Alcohol make the Body- 
Cold ? — What color has the face of a man who has 
just been drinking? What are the effects of 
alcohol upon the nerves which control the muscular 
walls of the blood vessels .? Can you explain why 
alcohol makes one red in the face } Does this red- 
dening of the skin make one feel warm or cold 1 
Why does blushing cause your face to feel warm .? 
Do the nerves of feeling end near the surface or 
deep in the body? When you feel warm or cold, 
what part of the body is really warm or cold ? 

Where does the warm blood come from that 
warms the surface? Is it warmer or colder when 
it gets back to the heart? Why must you wrap 
up a hot iron or brick when you wish it to re- 
main hot? Why then is the blood cooler when 
it leaves the surface ? How do some people use a 
spoon in order to cool hot soup ? Does alcohol 
cause all the blood to become cool at once, or a little 
at a time, as in cooling the soup ? What parts of 
the body are chilled by the cool blood that leaves 
the skin? Is it more important to have a warm 
skin or a warm heart ? How does alcohol deceive 
the drunkard about the temperature of his body ? 

Alcohol also makes him think he is strong when 
he is weak, wise when he is foolish, rich when he is 
poor. What does the Bible say of wine ? What does 



HYGIENE OF THE CIRCULATION 85 

it say of the man who is deceived by strong drink ? 
Is it true that alcohol " warms up the inner man " ? 

Give a connected account, either orally or in writ- 
ing, as your teacher may direct, of " How Alcohol 
makes the Body Cold." The lumbermen of Maine, 
and others whose business takes them out in the 
severe winter weather, have learned that people who 
drink whisky to keep warm freeze to death more 
quickly than those who abstain from drinking. 

" Nowhere is it so cold as in the Arctic regions. 
A while back a brave set of men offered to go and 
try to find Sir John Franklin, who was, alas ! lost 
amid those vast lonely ice-fields. The ship was 
built and packed, and a plentiful supply of whisky, 
gin, and brandy was put in for the men's use ; and 
all safely reached the land of ice and snow, and soon 
began their search. A ' nightcap,' as they called it, 
was served out to each one as he was huddled up in 
the skin bag that served for his bed and blankets, 
and then the last man out took an extra strong dose 
himself, and joined the others ; and they were only 
too glad when morning came if they found no one's 
ear ready to drop off or his nose dead because cir- 
culation had stopped and the frost had bitten it. 

" If ever it was cold, it was there ; if ever grog 
could 'keep the cold out,' then was its chance. 

" Once a little band of the sailors tried to get 
across a great ice-field to see if something they saw 
by the field-glass was either the lost ship or the huts 
of the men they had come to find. It was very 
rough, hard walking, and the grog-barrel had to be 



86 PHYSIOLOGY FOR BEGINNERS 

left behind. What grumbles there were at no ' night- 
caps ' ! What fears that they should be frozen without 
the grog to keep the cold out ! But when morning 
came one man after another confessed to his fellows 
that he had been warmer than usual that night. 

" The news spread ; other men tried to do without 
the ' nightcap,' with the result that at last nearly all 
refused it, finding it useless. 

" I could tell you other stories about beer, and 
how the soldiers marching in the sweltering heat of 
Afghanistan found no strength in beer, and left it 
all behind in the desert." — Mrs. Barnett. 

Clothes and the Circulation. — Which are more 
interfered with by pressure, the veins or the arteries } 
Which are situated nearer the surface. The veins, 
you will remember, have thin walls and are not 
directly affected by the beating of the heart. Tight 
garters often cause cold feet. Bands around the 
waist tight enough to support skirts interfere with 
the return of the blood to the heart from the lower 
part of the body. Tight collars or other tight cloth- 
ing around the neck, may cause weak eyes, a dizzy 
feeling, headaches, and frequent colds. Even a 
tight shoe may interfere with the circulation and 
add to the work of the heart. 

How all the Organs depend upon the Blood. — If you 
realize how the work of eyery organ in the body 
depends upon the heart, you will be careful not to 
weaken it or add to its load by wearing tight cloth- 
ing, by neglect of exercise, or by doing anything 
else that will injure it. 



HYGIENE OF THE CIRCULATION 



87 



Unless the brain is supplied with pure blood, the 
mind lacks clearness and cannot do its work well. 
The chest must be sufficiently expanded to allow 
the blood to circulate through the lungs freely and 




Fig. 39. — Men of the Lifc-sa\ing Service at work on the shore. Do you see 
the lifeboat ? The storm is too great for it to be used. Do you see the 
cannon? The men are shooting a ball to which is attached a cord. The 
people on the ship will draw over the rope that is on the spool and come 
to shore in a basket. Suppose the Life-saving crew had shot down the flag 
of distress on the mast and said all was well; that is the way people do who 
take headache medicines, cough medicines, etc., to stop the pain. 

to secure an abundance of fresh air, so that the 
blood may be enriched with oxygen and the waste 
matter carried out. 

Every part of the body is unfavorably affected by 
impure blood. To do its work well and remain in 
a healthful condition, each organ must be supplied 
with pure blood. If the muscles are not properly 



88 PHYSIOLOGY FOR BEGINNERS 

nourished, they soon become fatigued and work is 
performed with difficulty. 

The stomach needs blood to aid in digesting the 
food. Unless the skin is properly supplied, it loses 
its healthful color and becomes pale, or dark and 
dingy. Even the strength and soundness of bone 
depend on the kind of blood suppHed to it. 



CHAPTER VII 

FOOD 

Review Questions. — What is the element in the 
air that we take into our bodies through the lungs ? 
What does this element do in the different organs ? 
What gas is thus formed ? How does the body get 
rid of this gas ? What is chest expansion ? Waist 
expansion ? 

The Alimentary Canal. — We take air into the 
body through the lungs, but we take all solid and 
liquid food through the mouth, which is the begin- 
ning of the alimentary, or nourishing, canal. This 
canal is a tube nearly thirty feet long in grown per- 
sons, but it is folded in such a way that it takes up 
very little room. 

The food builds up and repairs the body, and by 
burning keeps the body warm and enables it to 
move. Thus the food serves several purposes. 
Since the muscles and other organs differ 
from the food which is to nourish them, it must 
undergo a change before it can be used by the 
body. Food cannot pass through the walls of the 
alimentary canal in the condition in which it is 
when eaten. Digestion is the change which the 
food undergoes in the alimentary canal. After 
food is digested it can pass through the walls of 

89 



go PHYSIOLOGY FOR BEGINNERS 

the canal and can be dissolved by the blood just 

as sugar or salt are dissolved by water. 

Oxidation. — You learned that oxidation in the 

body and the burning of a candle alike take place by 

the union of two things. What are they .'' Which 

of the two things in the body corresponds to the 

tallow of the candle .? 

Of two horses eating the same 
quantity of food, which is more 
likely to be fat, the idle horse or 
the horse that works hard? Do 
you have a better appetite when 
you work and play or when you 
do nothing.? Which are more 
likely to have good appetites, 
boys or girls } Why ? The facts 
suggested by these questions go to 
show that food enables us to do 
work. If we do not breathe pure 
air, food does us but little good. 
Explain why. Pure air contains 

Fig. 40.— The Sugar- oxygen. How does oxy gen enable 

cane supplies great ^ j^ ;> 

quantities of sugar. U&LUWUIK. 

Oxidation is always accompa- 
nied by heat ; the oxidation of the food in the body 
gives rise to the heat which keeps the body warm. 
Sugars, starches, and fats are the foods which give 
most heat and power. They are also stored up in 
the body as fat. 

Tissue Making. — The stove furnishes a means for 
the oxidation, or burning, of wood, the lamp wick 




FOOD 



91 



for the oxidation of oil, and the tissues for the oxi- 
dation of food. The tissues, like the lamp wick, are 
oxidized slowly and have to be repaired. Certain of 
the foods that we eat are used by the tissues in repair- 
ing themselves. They are called the flesh-forming, 
or tissue-making, foods. All foods of this kind con- 
tain a substance called proteid (pro'te-id). The albu- 
men, or white, of an egg is an example of a proteid. 

You may have heard that the body is entirely 
renewed every seven years. Very active parts, like 
the heart, are probably renewed in two or three 
months, but the less active organs, such as the 
bones, require a longer time. 

Food also enables the brain and nerves to act, 
hence it enables us to think. Now name all the 
uses of food that have been mentioned. 



Foods that are chiefly 
Tissue builders (Proteids) 


Foods that are chiefly 
Fat and Heat Givers 
(Fat, Starch, Sugar) 


Foods belong- 
ing to both 
Classes 


cheese 


butter and cream 


milk 


white of egg 


fat meat, lard 


eggs 


lean meat 


honey, sugar 


meat 


the gluten or 


starch of flour 


chestnuts 


sticky part of 


and meal. 


pecans 


flour and meal 


corn, rice 


and other 


beans 


cottonseed oil 


nuts 


peas 


olive oil 
potatoes, turnips 


fruits 



Some foods contain very little nourishment, being 
made mostly of water and woody fiber, as green 



92 



PHYSIOLOGY FOR BEGINNERS 



vegetables. Fruits contain much water, but not much 
woody fiber. Water and salt are important foods ; 
they are not placed in either 
column, as they enable us to 
use the heat-giving and tissue- 
building foods. In which 
column would you put to- 
bacco? Some persons chew 
tobacco. Why do they not 
swallow it? What is the dif- 
erence between a fat person 
and a fleshy person .? Which 
of the two has the greater 
strength .? Name two foods 
of which we may eat freely in 
summer; less freely. Name 
two foods of which we may eat 
freely in winter. Are hearty 
eaters or light eaters more 
likely to suffer from heat in 
summer .? 
An Eskimo boy prefers a tallow candle to cheese. 
Explain why. 

Meat is a nourishing food, but if more than a 
proper proportion is eaten, the albumin forms a 
substance which tends to make one cross and irri- 
table. 

Fats give more heat than starch or sugar. The 
best kind of fat to eat is in foods that are not cooked, 
as butter, olive oil, and oily nuts. Hickory nuts, 
butternuts, pecans, and walnuts are oily nuts. They 




Fig. 41. — Olive Branch and 
Fruit. Olives and nuts 
supply nutritious oils. The 
olive is nearly black when 
ripe. Green olives are of 
no value as food. 



FOOD 93 

should not be eaten early in the autumn as they 
may not then be perfectly ripe. They should be 
thoroughly chewed. 

Cottonseed oil mixed with lard is used in cooking. 
This oil is shipped to Europe, refined, and sold as 
olive oil. Much of it comes back to 
America under that name. 

Many things which we eat contain 
several kinds of food. Wheat flour 
contains starch, sugar, and proteid 
called gluten. Peas and beans are 
rich in starch, and contain more tis- 
sue-making food than any of the 
grains. Irish potatoes contain starch ; 
they are more than two thirds water. 
Corn contains starch, gluten, and oil. 
Yellow corn has more oil than white 
corn. Lime and phosphorus are also 
found in grains : with gluten they help 
to make bones and teeth. Hence the 
whitest flour, which is mostly starch, 
is not so good as the flour which con- 
tains all the elements found in the 
grain. What kinds of food are con- 
tained in milk? In eggs.? Eggs do ^'°- 42— wheat 

1 r 1 • • supplies more 

not contam so much of heat-givmg food than any 
food as of tissue-making food. The °"'" s'^'" ^;=- 

'-' cept rice. It 

former is not needed, for the hen contains much 
keeps the unhatched chick warm with pfo'^id. 
her own body. Hence the yolk is smaller than the 
white of the egg. 



94 



PHYSIOLOGY FOR BEGINNERS 



Water is the most necessary of all foods. Many 
nations use no other drink. Nearly three fourths 
of the body is water. Fruits and vegetables con- 
tain miich water. Besides the water we get in our 
food we should form the habit of drinking freely 




Fig. 43. — Rice in the Hull. 

Rice feeds more people than any other grain. It is chieiiy starch. In what coun- 
tries is it the chief food supply ? In those countries the people eat peas or beans 
or cheese or nuts to supply the proteid which is lacking in rice. 

every day good, pure, cool water. Dr. Tanner lived 
forty days, almost six weeks, without taking any food 
or drink other than water. If he had done without 
water also, he would probably not have lived a week. 
Sometimes tired and thirsty people drink glass 
after glass of ice water. Such recklessness may 



FOOD 95 

lead to congestion of the blood in certain organs 
and result fatally. Ice water does not quench 
thirst like cool water. Drinking much of it makes 
one thirsty. If you cannot get any water to drink 
except ice water, either sip it very slowly or wait 
until it is cool instead of cold. 

Besides common salt, which is found in the earth, 
other salts are needed as food. We cannot digest 
them in their mineral form, but they are found in 
fruits and green vegetables. In this form they are 
digestible. The salts of iron and phosphorus are 
the most important of these. It is iron that gives 
the red color to the blood ; it gives the red color 
to tomatoes also, and the brown color to wheat and 
other grains. 

Besides the salts, green vegetables contain very 
little nourishment for man. They resemble grass. 
Such substances are very useful as food for cattle ; 
with them digestion is a slower process than with 
man. Cows and sheep have four stomachs and can 
digest grass. 

How many of the girls in the class are learning to 
cook ? They should begin with the easier dishes. 
If a girl wishes to learn music, she should begin 
with an easy instrument like the guitar. If she 
cannot learn to play it, she will know that she can- 
not learn the piano. But many a girl who is making 
a failure with music could become expert in cook- 
ing. Good cooking keeps half the food from being 
wasted, saves half the doctor's bills, and doubles the 
happiness of the home. 



96 PHYSIOLOGY FOR BEGINNERS 

THE FOX WITHOUT A TAIL 

A fox was once caught by the tail in a trap. He 
knew that he would be killed if the hunters found 
him there. So he managed to get away, leaving his 
tail in the trap. 

He felt very much ashamed to be without a tail, 
and tried to keep from meeting any of his friends. 
He was afraid they would laugh at him. 

After a while he called his friends together and 
talked to them about it. 

" You really can't think," said he, " what a nice 
time I have without a tail. Tails are so much in 
the way. I can get about much more easily since I 
lost mine. 

" I am sure you would all look a great deal better 
and be much happier, if you would have your tails 
cut off." 

" If you think so,," said an old fox, " why didn't 
you have your tail cut off before ? I think you 
would be very glad to get it back again if you could. 
You want us to have our tails cut off only that we 
may look as bad as you." 

Once there was a boy who learned to smoke. He 
began by using cigarettes which are about half as 
big as your little finger. They are so weak that a 
boy who is hardly more than a baby could smoke 
one by drawing the smoke into his mouth and it 
would not make him sick. 

Very soon this boy learned to smoke a number of 
cigarettes each day and to draw the smoke into his 



FOOD 97 

lungs. This made him weak and he became a slave 
to cigarettes. Everybody lost respect for him. He 
did not grow so fast as the other boys and was not 
so sound and strong. He could not study and keep 
up with his class. 

He was afraid the other boys would laugh at him, 
so he said to them, " You really can't think what a 
nice time I have with cigarettes. They are not at 
all in the way and I am sure you would look better 
and be much happier if you learned to smoke them." 
. But one of the boys said, " You only want us to 
smoke cigarettes so that we will not get along any 
better than you do." 



CHAPTER VIII 

DIGESTION 

Review Questions. — At what temperature is the 
body kept ? What furnishes the heat that keeps it 
warm ? What are the two functions of the blood ? 
How does alcohol make the body cold ? What is 
the length of the alimentary canal ? Why is it nec- 
essary for food to be digested before it can become 
tissue? Of what does the change called digestion 
consist ? 

The Teeth. — In order that the digestive fluids 
may penetrate the food and make it soluble, it must 
first be ground very fine. Look at your teeth in a 
mirror. Use a hand mirror. (Have your back to 
the light so that the mirror may reflect the light 
into the mouth.) Also feel the teeth with the fin- 
gers. What is the shape of those in front ? Of 
those in the rear part of the jaw ? Which are suitable 
for cutting ? Which for grinding ? How many cut- 
ting teeth are there ? 

The Two Sets. — When a child is about six years 
old, the teeth of the first set, usually called the milk 
teeth, begin to drop out, and the secondj or perma- 
nent set, takes their place. This set numbers thirty- 
two teeth and is not completed until the person is 
grown. 

98 



DIGESTION' 



99 



In the center of each tooth there is a hollow con- 
taining pulp, consisting chiefly of blood vessels and 
a nerve. Most of the substance of a tooth is made 
of dentine, something like bone. The part outside 
the gum is covered with a thin layer of enamel, a 
very hard, shiny substance comjoosed of mineral. 

Decay of the teeth results from fermentation of 
particles of food lodged between the teeth. In this 



The Grind-ero 



The Chewera The Bog Teeth The Biters 
(Bifioid'C) iC"int) {l-,cisors). 




Fig. 44. — The Teeth Classificil. 

This figure shows the eight teeth in one half of the jaw. Hence, aUhough there are 
but three molars, two bicuspids, one canine, and two incisors in the figure, there 
are actually four times as many of each in the wliolc set of teeth. 

way an acid is formed. The acid dissolves the min- 
eral matter of the teeth. This acid is readily formed 
from sugar. Perhaps you have heard some one say to 
a small child, " Let me look at your teeth ; I want to 
see whether you bother your mother's sugar barrel." 
The excessive eating of sweet things at meals or eat- 
ing sweets between meals is injurious to the teeth. 

Many persons like to eat a dry crust after finish- 
ing a meal. If they stop eating with a sweet taste 
in the mouth, the mouth may become sour. If one 
cracks hard nuts with the teeth or chews rock candy, 



100 PHYSIOLOGY FOR BEGINN^ERS 

the teeth are apt to slip, and in striking against one 
another the enamel is cracked. 

Washing the teeth helps to preserve them. 
Wooden toothpicks are very useful, but the best 
way to keep the teeth healthy is to use them on food 
that is tough and hard enough to require good chew- 
ing. Some young people refuse to eat the crusts of 
bread, and bread that is tough, because it has not 
been " shortened " with lard. One would think 
they were old people without any teeth. 

Cows and sheep are believed to have had upper 
front teeth a long time ago. By forming the habit 
of using the tongue instead of those teeth, when 
grazing, they have lost them through disuse. The 
upper jaw of a little calf has the beginnings of those 
teeth, but they disappear later on. Any gift that is 
not used is soon taken away. The fish in the waters 
of dark caves lose their eyes and become blind. The 
mole has almost lost its eyes because it uses them so 
little. In order to preserve the teeth, we should eat 
food that needs chewing and we should chew it well. 

There is another reason for chewing the food well. 
By chewing, the saliva is thoroughly mixed with the 
food. If you chew some grains of wheat, a cracker, 
or some bread, for a long time, you notice that it 
acquires a sweet taste. This is because part of the 
starch in the food has been turned to sugar by the 
saliva. Thus one important step of digestion is per- 
formed in the mouth. The proteids and fats are 
not acted upon by the saliva. 

Fear, anxiety, and other strong feelings prevent 



DIGESTION 



lOI 



the flow of saliva. In India people suspected of 
thieving are sometimes made to chew rice. If the 
rice remains dry, the man is deemed guilty. 

The saliva is secreted, or formed, by six organs 
called salivary glands. The saliva should never 
be wasted by 
useless spit- 
ting, such as 
smoking or 
chewing to- 
bacco induces. 
Chewing-gum, 
unlike tobac- 
co, contains no 
poison; the 
saliva arising 
from the use 
of the gum is 
usually swal- 
lowed. This 

irritates the stomach. Nevertheless, chewing gum 
is not nearly so injurious as chewing tobacco. 

The gullet is a fleshy tube leading from the throat 
to the stomach. You can feel the gristly windpipe 
in the front of the neck. The gullet is behind the 
windpipe, hence the food has to pass the upper end 
of the windpipe to enter the gullet. The windpipe 
has a lid that covers it when we swallow. It would 
not do for food to enter the windpipe. (Fig. 22.) If 
you talk or laugh when there is food in the mouth, 
the food may be sucked into the windpipe before the 




Fig. 45. — Salivary Gland, drawn slightly enlarged to 
show the many little sacs opening into the ducts. 
This gland is in the cheek. It swells in a disease 
called mumps. 



I02 



PHYSIOLOGY FOR BEGINNERS 




Fig. 46. — The Stomach, showing the 
direction of its Muscular Fibers. 



lid can close. Sometimes a slap on the back helps 
one who is choking to cough up the obstacle. 

The stomach is a pear-shaped bag placed across the 
upper part of the abdomen just below the diaphragm. 

It is capable of holding 
about two quarts. The 
larger end is on the left 
side where the gul- 
let enters; the smaller 
part is toward the 
right side and opens 
into the intestine. The 
stomach has two open- 
ings or mouths. Are 
both openings on top } 
(See Fig. 46.) Around the opening into the intes- 
tine is a band of muscle which regulates the size 
of the opening and the passage of the food. 

The lining of the stomach is soft, like velvet, and 
contains many little glands which secrete a liquid 
called the gastric juice. Have you ever seen a 
piece of tripe at the meat market .? This is the 
stomach of an ox or a sheep, and gives you an 
idea of the thickness of the wall of the human stom- 
ach. It also shows the velvety appearance of the 
lining. Outside of the soft lining there is a layer 
containing muscular fibers which contracts in such 
a way that the food is gently moved from one end 
of the stomach to the other. This movement mixes 
the food with the gastric juice. 

Only one kind of food is digested in the stomach; 



D/GEST/OJV 



103 



this is the proteid matter. Give examples of such 
food. Chyme is the name given to the food in the 
stomach, when, after two or three hours' digestion, it is 
reduced to a pulpy and 
almost fluid condition. 
Some of the food that 
is already digested is 
absorbed by the blood 
vessels in the walls of 
the stomach, but the 
greater part gradually 
passes into the intes- 
tine. In order to pass 
through the narrow 
opening into the in- 
testine, it must be 
sufficiently softened, or 
the band of muscle 
called the pylorus (or 
gate keeper) will not 
allow it to pass. Could 
a carpenter make a a 

gate which would open Fig. 47.— AU of the Alimentary Canal ex- 

itself at the right time "p' ^^^ "°""' ^"'^ g"'^^'- 
and allow certain peo- 
ple to pass yet stop- 
ping others .? 

In the first part of 
the intestine the chyme mixes with two fluids, 
called the bile and pancreatic juice. The bile 
comes from the liver, and the pancreatic juice 




Where does 
the stomach join the small intestine ? 
Does the small intestine join the large 
intestine, or colon, on right or left side ? 
The colon goes up, across, down, then 
has an S-shaped curve and a straight 
portion. 



104 



PHYSIOLOGY FOR BEGINNERS 



GUUrr {(EsopKagwi). 



comes from the pancreas, a long flat gland placed 
behind the stomach. The bile acts upon the fats, 
which withstand the action of both the saliva 
and gastric juice. The pancreatic juice is the 

most impor- 
tant of all the 

The stomach Door dip'PStivP fluids" 
.^(Cardiao Orifice,. UlgCOUl VC UU1U3 , 

this changes 
to sugar any 
starches that 
the saliva does 
not digest. It 
likewise acts 
upon the pro- 
teids which the 
gastric juice 

Fig. 48.— The Stomach and the Beginning of the doeS not diofCSt ' 
. Small Intestine, and their Connections. , . , . , 

and With the aid 
of the bile it act upon the fats. The pancreatic juice 
is the only fluid that acts upon three kinds of foods. 

The bile is secreted by the liver at all times; it 
is stored until needed in a little greenish bag, 
called the gall bladder. Thus a sufficient amount 
can be stored up ready for use. Some animals 
have no gall bladder ; the horse is one of these. 
You may have noticed in the kitchen that the cook, 
when cleaning a fowl, is very careful not to burst 
the gall bladder. The bile is bitter, and if it were 
spilt upon the fowl, it would spoil the taste of the 
meat. 

The liver not only produces bile to digest the 




DIGESTION- I OS 

fats, but it is also a scavenger. It removes from 
the blood by burning them up the poisons of al- 
cohol, coffee, tobacco, and drugs ; thus it partly 
saves the other organs from being injured by them. 
Lastly, the liver is a storehouse, keeping in store a 
kind of sugar which is formed from starchy food. It 
gradually gives this sugar to the blood as the body 
has need for it. How many purposes are served by 
the liver.? Name them. 

You learned that the blood vessels take up most 
of the food when it has been absorbed from the ali- 
mentary canal. Thus the food is carried all over 
the body by the circulation. The blood always 
remains in the blood vessels, going the same round 
over and over again. The food, in order to get into 
the hungry tissues and feed them, must soak through 
the walls of the capillaries, thus leaving the circula- 
tion. The red corpuscles never go out into the 
tissues, but some of the watery portion of the blood, 
containing the food, passes through the walls into 
the tissues. After passing through the walls it is 
a colorless liquid called lymph (limf). When the 
tissues have used as much food as they need, the 
colorless, water}"^ lymph goes back to the blood in a 
very curious way. There are many little tubes, 
called lymphatics (lim-fat'ics), which begin with 
open ends in the tissues of the body. Every 
motion of the body serves to push some of the 
lymph into the open ends and to move it along the 
lymphatics. The lymphatics, unlike the blood ves 
sels, have no heart to push the lymph along, but 



I06 PHYSTOLOGY FOR BEGINNERS 

it is moved forward by the pressure of muscles 
and by movements of the body. The small lym- 
phatics unite with larger ones until the lymph 
is finally carried into two large lymphatics which 
empty the lymph into the blood near the neck. 
Thus waste of the food is prevented. Our bodies, 
like an economical housekeeper, allow no nourish- 
ment to be wasted. 

The lymphatics called the lacteals have another 
use. The blood vessels themselves absorb all the 
food but the fats. The lacteals, which are the lym- 
phatics around the small intestines, absorb the 
digested fat. The fats thus get into the blood in an 
indirect way. The lacteals empty into the large 
lymphatics, which, in turn, empty into the large veins 
near the neck, as stated before. 

When the food enters the blood it becomes a 
part of the body. Up to this time it cannot be 
called a part of the body, although, in one sense, it 
is in the body. 

The part of the food which is not absorbed by 
the blood is carried through the small intestine 
into the large intestine. 

The glands which secrete the digestive fluids are 
affected by the mind as well as by the food. Nerves 
excite the glands to secrete when we taste, see, 
smell, or even think of food. At the same time the 
nerves dilate the blood vessels in the glands, so that 
the glands may have plenty of blood with which to 
carry on their work. The food digests most readily 
if one when eating is in a cheerful, happy frame of 



DIGESTION 107 

mind. An old Eastern story tells of a stranger who 
met the Plague coming from Bagdad. " You have 
been committing great havoc there," said the 
stranger, pointing to the city. " Not so great," re- 
plied the Plague ; " I killed only one third of those 
who died; the other two thirds killed themselves 
with fright." 

The glands of the digestive organs tire as well as 
the rest of the body; so do the muscles in the walls of 
these organs. The stomach and intestines should not 
be made to work all the time, or at all hours, or they 
will surely wear out. If good food is properly eaten 
at regular times, the stomach can do its work in two 
or three hours after each meal and have time to get 
rested before the next meal. If indigestible food is 
eaten, or if food is eaten between meals, the stomach 
does not get any rest. It cannot be expected to do 
its work well without rest. 

Do you remember what the temperature of the 
body is .? The stomach must be at the same tem- 
perature in order to work. Ice water is often not 
much above freezing point. If taken freely at 
meals or soon after, digestion stops until the tem- 
perature of the stomach is equal again to th& bodily 
temperature. Such interruptions of the stomach's 
action are a fruitful source of indigestion. The 
person who eats ice cream very slowly is not only 
more polite, but also enjoys it more. Food digests 
more rapidly if eaten slowly. 

If water is used at meals, it should never be 
taken while there is food in the mouth, because it 



I08 PHYSIOLOGY FOR BEGINNERS 

checks the flow of the saHva. Dry food is as 
necessary for the action of the salivary glands as 
hard food is for the health of the teeth. Soft, 
moist foods interfere with the flow of saliva. 
It is better to drink plenty of water between meals, 
as it may dilute, or weaken, the gastric juice if taken 
at meals. But persons who do not drink enough 
water at other times, find that health and digestion 
are aided by drinking at meals, because the body 
needs a certain amount of water. 

Hot drinks, such as hot coffee, toughen the 
lining of the mouth, and may cause the gums to 
shrink back so as to expose the part of the teeth 
not covered with enamel and thus hasten their 
decav. 

Are the requirements for healthy living burden- 
some or is life made more pleasant by meeting the 
requirements? Which has the greater pleasure, 
the one who bolts his food and gulps his drink, 
or the one who eats slowly and spends more time 
at his meals ? Which enjoys the pleasures of the 
table the more, tke one who eats regularly or the 
one who, like a chicken, is always ready to eat, and 
who, by munching candy and nuts between meals, 
destroys the appetite for meals.? We enjoy the 
taste of food when we are hungry. If we eat when 
we are not hungry, we may be punished for it by 
having indigestion. 

Some persons lose their appetites because their 
lives are not active enough ; they do not work enough 
to burn up, the food they eat. They are always put- 



DIGESTION 109 

ting fuel into the furnace, but never have enough 
fire to burn it. So they lose appetite for good and 
simple food, but they are not wiUing to stop eating 
until the appetite returns. They put mustard, 
pepper, and other hot seasoning into the food to 
wake up the nerves, thus enabling themselves to eat 
food that they do not need. If a little pepper were 
to get into the eye, the eye would smart, become 
inflamed, and pour out tears to protect itself. The 
lining of the stomach also is delicate and easily 
inflamed. The hot seasoning put into the food 
causes mucus to flow to protect the stomach, but it 
does not increase the gastric juice or aid digestion. 
How can such people get honest and natural appe- 
tites.'' What kind of people usually have the best 
appetites? Sometimes, when the appetite is gone, 
kind friends attempt to awaken it by making broths 
and other delicacies. This is usually unwise, de- 
priving the stomach of needed rest. How is it 
that living in overheated rooms or wearing too 
warm clothing decreases the appetite as much as 
lack of activity does. 

We should not eat when we are very tired. 

We should rest from work for half an hour after 
a meal or take only gentle exercise. 

We should not eat heartily at supper. We 
should not eat between meals nor should we ever 
omit a meal unless we have no appetite. When 
the stomach is in the habit of digesting at a certain 
hour, the glands secrete the digestive fluid at the 
proper time. When food comes into the stomach 



no PHYSIOLOGY FOR BEGINNERS 

at an unexpected time, the juices do not flow so 
freely. The stomach works better when it contains 
a moderate amount of food than when it contains a 
very large or a very small amount. Both the glut- 
ton and the one who eats between meals make its 
work hard. 

If you pour alcohol on the white of a raw egg, 
the white becomes hard. Alcohol also hardens 
lean meat and other proteid food. You learned 
that the work of the digestive organs is to soften 
and dissolve the food. Anything which hardens 
the food interferes with the work of the stomach 
and intestines. 



CHAPTER IX 

STIMULANTS AND NARCOTICS 

Review Questions. — What effect upon growth do 
alcohol and tobacco have (Chapter I) ? What effect 
upon the nerve cells of the drinker does alcohol 
have ? Upon the nerve fibers ? Upon his mind 
and character (Chapter II)? Why are cigarettes 
worse for the lungs than cigars (Chapter IV)? 
What is the result when people try to drown their 
sorrow by drinking alcohol ? Explain how the so- 
called stimulating effect of alcohol upon the heart 
is really a narcotic or deadening effect (Chapter 
VI). Is the rapid beating of the heart any gain in 
energy to the drinker in the end ? What kind of 
food is made indigestible by alcohol (Chapter VIII) ? 
Is a stimulant something that takes strength out of 
a man or something that puts strength into him? 
What two things unite to form carbon dioxid? 
How is carbon dioxid gas formed in a fire ? How 
is carbon dioxid gas formed in the body? 

Foods that Spoil. — You know that there are 
many foods which do not keep fresh and pure. 
They spoil in a short time and become unsuited for 
food. Milk becomes sour, butter becomes rancid, 
meat decomposes. In this chapter you are to learn 



112 PHYSIOLOGY FOR BEGINNERS 

about the spoiling of sugar and of foods that contain 
sugar. You may have noticed that sweet preserves 
sometimes spoil, or " work," as your mother calls the_ 
change, and bubbles of gas form at the top of the 
glass jar. This gas is carbon dioxid, about which 
you have already studied. One other substance is 
formed by the spoiling of the sugar ; it is the poison- 
ous liquid, alcohol. 

The fresh juice pressed out of apples is sweet 
because it contains sugar. It is called sweet cider, 
a pleasant drink. The sugar was formed in the 
apples as they ripened in the sunshine. The cider 
does not remain sweet unless the weather is very cold. 
It loses its sweetness because the sugar changes into 
the same gas and liquid which form when preserves 
spoil. It is then called hard cider. 

You could not imagine what causes this change. 

The change is caused by tiny plants which grow 
upon the moist sugar. If the sugar is warm as well 
as moist, the yeast plants grow very rapidly. These 
plants are so small that they cannot be seen without 
a microscope. They float in the air. When you look 
about you in the room, you may think there is noth- 
ing floating in the air. If you close the shades, or 
shutters, and allow a sunbeam to come in beneath 
one window shade, you see countless specks of dust 
in the sunlight. 

The yeast plant is much smaller than a speck of 
dust. It can be seen with the aid of a microscope. 
Yeast plants are usually found on the skins of fruit, 
as well as in the air. They can do no harm so long 




STIMULANTS AND NARCOTICS 113 

as the skin of the fruit is unbroken, because they 

cannot reach the sugar. When the apples are 

crushed, the yeast plants are 

washed into the juice, and in 

a few hours, if the weather is 

warm, they begin to grow. 

The change produced in the 

sugar by the growth of the 

yeast is called fermentation. 

On account of fermentation, 

it is better to eat the fruit than ' '*^''~ 

to drink the juice, unless the latter has been pressed 

out only a short time before. 

A Delicious Drink. — The juice of ripe fruit, such 
as grapes, blackberries, or raspberries, may be made 
into a delicious drink if the juice is heated as soon 
as it is pressed out, in order to kill the yeast plants. 
It should then be sealed while boiling hot, in air- 
tight jars or bottles, so as to keep out the yeast plant 
which causes the fermentation. 

Sometimes people make blackberry cordial, wine, 
or persimmon beer, and say that it contains no 
alcohol because they put in none. If they do not 
keep the yeast germs out, it is not necessary to put 
in alcohol, for yeast plants soon produce it. If bub- 
bles of gas are seen in root beer, alcohol is forming 
along with the gas. About one twentieth of cordial 
is alcohol ; the rest of it is water, sugar, and flavors. 

We have found that alcohol is the product of de- 
cay, or the result of rotting. You need not think it 
strange that alcohol is a poison. It is so poisonous 



1 14 PHYSIOLOGY FOR BEGINNERS 

that after a good deal of it has formed, it kills even 
the yeast plants forming it, and then alcoholic fer- 
mentation ceases. There is another kind of germ 
which also gets into the cider if the latter is exposed 
to the air. This germ forms acetic acid. 

Acetic acid is the acid in vinegar which gives it the 
sour taste. Vinegar is no more a food for man than 
alcohol. The second fermentation, called acetic acid 
fermentation, soon changes all the alcohol to acetic 
acid. The cider has changed to vinegar. If you 
were to drink a glass of vinegar, it would be very 
injurious, and there is no advantage in using it in 
small quantities. Do you remember the reason 
why some people use vinegar and other seasoning 
as given in the last chapter? Most of the vinegar 
sold at the present day is not made from apples 
and is often adulterated with acids more poisonous 
than acetic acid. Sometimes silly girls drink weak 
vinegar to reduce fat. It usually accomplishes the 
purpose. It does so by breaking down their health. 
Even if they recover their health, they are weakened 
for life. It is much easier to retain health than to 
regain it after it is lost. 

A process of decay does not furnish food. The 
products of decay cannot support life.. Food is pro- 
duced by growth in the sunshine, not by decay. 
The bright rays of the sun give energy to the plant 
afid enable it to live and store up food for its 
own use and for the use of animals. It is strange 
that some men have been deceived so long, that 
they seek to get life and strength, not from sun- 



STIMULANTS AND NARCOTICS 115 

shine, oxygen, and food, but from things that are 
rotting. 

When we consider the sorrow, sickness, and misery 
which the use of alcohol brings on the human race, 
it seems stranger still that the race has been so long 
in comprehending the true nature of alcohol. Many 
of the boys and girls now growing up have a chance 
to learn the whole truth. As men and women they 
will be able to exert much influence upon those who 
are ignorant from lack of opportunities for educa- 
tion. Those who have begun the use of alcoholic 
drinks ignorant of the consequences are to be pitied. 
Many of them become such slaves to the habit that 
they have not strength of will to abstain even after 
learning the truth. 

The use of fermented drinks probably began a 
long time ago, for men were unwilling to throw 
away grape juice, simply because it had fermented. 
Grapes spoil quickly and men did not know how 
to prevent fermentation by the easy method men- 
tioned above. Now with many persons the taste 
for pure, strengthening food has been changed into 
an appetite for stimulating poison. Men take ad- 
vantage of this appetite in order to make money, 
and make into beer even grain, which keeps sound 
for a long time. Barley is mostly starch and does 
not ferment, so it is kept in a warm, moist place 
until it sprouts ; the starch then changes to sugar. 
The sprouting grain is next heated enough to kill 
the sprouts ; the sugar is allowed to ferment, and thus 
beer is produced. About one twentieth of beer is 



ii6 



PHYSIOLOGY FOR BEGINNERS 



alcohol ; about one tenth of wine is alcohol. In 
Mexico a drink called pulque is made by fermenting 
the juice of the agave, or century plant. In Russia 
mares' milk is allowed to ferment and a drink called 
koumyss is the result. 

Water, lemonade, milk, and other healthful drinks 
satisfy thirst. But stimulating drinks, instead of 




Fig. 50. — Most railway managers do not allow ^ man who drinks alcoholic 
liquors of any kind to run an engine. If you traveled on a train, would 
you prefer the engineer of your train to be a drinking man or one who 
never drank ? 

satisfying thirst, create an appetite for more. Instead 
of nourishing, they exhaust. The craving for alco- 
hol leads men to seek stronger drinks than can be 
made by fermentation alone, .so the process of dis- 
tillation is used to concentrate the alcohol in the 
fermented liquors. 

Alcohol boils at a temperature about thirty de- 
grees lower than the boiling point of water. The 
fermented liquor is heated until it is so hot that the 



STIMULANTS AND NARCOTICS Wj 

alcohol boils, and rises as vapor, but not hot enough 
for the water to boil. The vapor passes through a 
tube running through a cooler vessel, when it con- 
denses in drops. Strong alcoholic drinks, called dis- 
tilled drinks, or '' spirits," are thus made. They are 
about one half alcohol. Wine, when distilled, makes 
grape brandy ; cider, apple brandy ; pulque, mescal ; 
beer, whisky. If juniper berries are added to the 
whisky for flavor, the mixture is called gin. In the 
West Indies, molasses that has fermented is dis- 
tilled and rum is produced. 

Whisky is often diluted with water for the sake 
of cheapness, and leather, tobacco, and acids are 
added to restore its strength. Drinks sold as wine 
are often made of things other than grapes. For 
instance, the wine called champagne, which is sold 
in England and America, is made mostly of cider, 
sugar of lead, and a poisonous berry called cocculus 
indicus, brought from India to London for the pur- 
pose. If a bird in India eats this berry, it dies 
before it can fly far away from the tree. 

Which are more apt to seek a stimulant, calm, 
brave, strong men, or excitable, nervous, anxious 
men ? Which is more apt to become a drunkard, a 
man who stops work when he is tired, or one who 
does not know when to stop, but goes on until he is 
exhausted .'' One who is cheerful, or one who has 
the "blues".? Men do not take alcohol because they 
like its taste, but because of its dulling effect upon 
the mind. By means of this effect it hides, for the 
time, feelings of weakness and thoughts of trouble. 



CHAPTER X 

HOW WE MOVE 

Review Questions. — What is a joint (Chapter I) ? 
Name three kinds of movable joints. What is a 
Hgament.? How many bones form the shoulder.? 
What is reflex action (Chapter H).? 

How Muscles Work. — The organs used for mov- 
ing the body are called muscles. The ends of the 

muscles are usually attached 
to the bones by strong 
bands called tendons ; the 
part of a muscle between the 
tendons is formed of flesh. 
The lean part of beef is 
muscle. A muscle is usually 
attached to two bones which 
form a joint between the 
points where the muscle 
is attached. 

Fig. (I. — The Biceps Muscle. »,^, 

When a nerve carries an 
impulse to a muscle, the muscle shortens and thick- 
ens. The shortening or contraction causes a move- 
ment of one of the bones to which the muscle is 
attached, the other usually remaining in position. 
The large muscle of the upper arm (the biceps) is 
fastened at one end to the shoulder blade and at the 

ii8 




HOW W£ MOVE 



119 



»!Poinfc of Origin 
of the Muscle. 



other to the forearm below the elbow joint. When 
this muscle contracts, its middle part swells up, and 
the' forearm, moving on a hinge joint at the elbow, 
closes up against the upper arm. If you catch hold 
of an immovable bar above your head, contracting 
this muscle as you do so, the shoulder is pulled 
upward toward the bar. Thus a muscle can, at 
different times, move either 
of the bones to which it is 
fastened. 

The Control of Muscles. — 
If the head receives a severe 
blow or shock, the brain 
suddenly ceases to control 
the muscles that keep the 
body upright, and the man 
faints and falls in a heap. 
The ligaments, or stout 
cords at the joints, keep the 
bones in their places so well 
that usually only a slight 
muscular effort is necessary 
to keep the body erect. 
This effort is under the control of the nervous sys- 
tem. Such acts as standing, walking, and moving 
the hands are performed when we will to do so. 
Voluntary muscles are those usually controlled by 
the will. Can you give an instance when voluntary 
muscles act without an effort of the will ? 

Other muscles, such as those of the heart and 
stomach, work without any -thought on our part. 




Fig. 52. 



I20 



PHYSIOLOGY FOR BEGINNERS 



We cannot cause them to contract, nor can we stop 
their action by any effort of our own. Muscles 
that are never under the control of the will are 
called involuntary muscles. Remember that their 
action is controlled by the nervous system, although 
not by the will. We did not say that voluntary 
muscles are always under the control of the will. 
Walking may sometimes be reflex, as in sleep- 
walking. Nearly every voluntary 
muscle may contract at the same 
moment, as when one jumps at 
the sudden slamming of a door. 
When we studied the nerves, what 
did we learn is the name given to 
such an act ? 

Structure of Muscle. — If you 
notice beef that has been boiled 
a long time, long enough to pull 
the muscles apart easily, you see 
that a muscle is made of thread- 
FiG. 53. like parts, or fibers. The micro- 

Running is good exercise, scope shows that each of these 

Both feet are off the '^ 

fibers is made of still smaller 




ground together a part 
of the time. 



fibers. When a muscle contracts, 
every one of its fibers thickens and shortens. 

Tendons. — What are tendons } Tendons may be 
felt very plainly in the bent elbow and under the 
knee. If the muscles contract very strongly, the 
tendons may feel as hard as bone. They are very 
strong. The butcher hangs up a whole hog by 
one tendon. Move the fingers, one at a time, and 



HOIV WE MOVE 121 

see the tendons on the back of the hand rise. 
The strongest tendon in the whole body is at the 
heel. Feel it with your fingers and notice it move 
as you move the foot on the ankle joint. 

What name is given to the nerves that carry 
impressions to the brain.? (See Chapter II.) What 
name is given to nerves that carry orders from the 
brain to the body 1 What besides two such nerves 
is necessary for reflex action ? 

In voluntary actions, the nerve, acting something 
like a telegraph wire, takes an impulse from the 
brain to the muscle, setting the muscle in motion 
unless it is so fatigued that it cannot act. Let us 
learn how the muscle gets the strength to move. 
The muscles continually build up their substance 
from the oxygen and food brought to them by the 
blood as it circulates through them. When the 
nerve excites the muscle to contract, the chemical 
change called oxidation takes place in the substance 
of the muscle, which gives off carbon dioxid to the 
blood. At the same time the muscle contracts and 
becomes warm. What is oxidation ? 

When gunpowder is exploded in a gun, the shot 
is forced out and the barrel of the gun becomes 
hot. The powder in the gun could have been ex- 
ploded by pulling a string attached to the trigger, or 
by sending electricity along a wire to the powder. 
The string or the wire corresponds to the nerve 
which goes to the muscle. The barrel of the gun 
corresponds to the muscle cells ; the powder corre- 
sponds to the food and oxygen stored up in the 



122 



PHYSIOLOGY FOR BEGINNERS 



muscle. The powder has to be supplied again ; 

likewise, the muscle substance, as soon as it breaks 

down, has to be built up again by the oxygen 

from the lungs and the food from the stomach. 

The waste -material of the muscle is carried away by 

the blood. It is chiefly carbon dioxid. 

Benefits of Exercise. — When people have only 

thin, flabby muscles attached to their bones, they 

are weak and cannot do 
much work. See what 
slim little legs many 
children in the city have. 
Children in the country 
climb hills, do work, and 
walk a long distance to 
school. They are more 
likely to be strong than city . 
children. This is because 
muscles are developed by 
use. 

Exercise has a favorable 

_ -, -.., ,. effect not only upon the 

Fig. 54. — Nerve ribers ending -' J^ 

among the muscle fibers which mUScleS, but Upon all partS 
they stimulate to contraction. ^j ^j^^ ^^^^^ Running, 

jumping, and brisk walking strengthen the arms, 
legs, and back ; but, more important still, such exer- 
cise makes the blood flow more rapidly, and a greater 
amount reaches the various organs. The blood 
causes the lungs to expand, because deep breathing 
is necessary to supply the air. It cleanses the skin 
and takes off waste matter by causing perspiration ; 




HOiV WE MOVE 123 

it develops a better appetite and keeps the digestive 
organs healthy. Vigorous exercise just after a meal 
is not good for the digestion ; a slow walk or other 
gentle exercise does no harm. We should not eat 
when we are very tired. No one should spend all his 
time doing one kind of work; this brings certain 
organs into play to the neglect of others. Organs 
become tired and rnust have rest, as we have 
seen when studying the heart. Change of occupa- 
tion brings different organs into play and gives the 
tired ones time to rest. A person who has been 
working all day with his hands or brain is rested 
by a brisk walk out of doors. The vessels in the 
tired organs are filled with blood. When the blood 
vessels in the brain are full of blood, the mind 
cannot rest. When the other organs are used, 
the blood is drawn away from the brain, giving it 
time to recover from the fatigue. One who has 
been walking all day, as in plowing, is rested by 
reading. 

" The voluntary muscles are very obedient ; they 
do exactly as we tell them. Sometimes' they do 
things without our knowing that we have told them ; 
but that is only because we have told them so often 
that they have got used to acting without fresh 
commands. I think it is a very beautiful fact, and 
it should help us very much to know that our wills 
can command our bodies, that even our ^fingers 
move because we order our muscles to move them. 
It should help us in times of temptation, for though 
it is true to say ' the flesh is weak,' it is also true 



124 PHYSIOLOGY FOR BEGINNERS 

to say ' the will is strong ' ; and as the poet has 
written it — 

" So nigh is grandeur to our dust. 
So near is God to man. 
When Duty whispers low, ' Thou must,' 
The youth repUes, ' I can ! ' " 



DIALOGUE BETWEEN FRANKLIN AND THE GOUT 
Paris, Midnight, October 22d, 1780. 

Franklin. — Eh ! oh ! eh ! What have I done to 
merit these cruel sufferings ? 

Gout. — Many things ; you have eaten too freely 
and too much indulged those legs of yours in their 
indolence. 

Franklin. — Who is it that accuses me ? 

Gout. — It is I, even I, the Gout. 

Franklin. — What ! my enemy in person ? 

Gout. — No, not your enemy. 

Franklin. — I repeat it — my enemy ; for you not 
only torment my body to death, but ruin my good 
name ; you reproach me as a glutton, and all the 
world that knows me will allow that I am not. 

Gout. — The world may think as it pleases, but I 
very well know that the quantity of meat and drink 
proper for a man who takes a reasonable degree of 
exercise would be too much for another who never 
takes any. 

Franklin. — I take — eh ! oh ! — as much exer- 
cise — eh ! — as I can, Madam Gout. You know 
my occupation, and on that account it would seem. 



HOW WE MOVE 125 

Madam Gout, as if you might spare me a little, see- 
ing it is not altogether my own fault. 

Gout. — Not a jot ; your rhetoric and your polite- 
ness are thrown away ; your apology avails nothing. 
If your business requires much sitting, your amuse- 
ments, your recreations, at least, should be active. 
But let us examine your course of life. While the 
mornings are long and you have leisure to go 
abroad, what do you do? Why, instead of gain- 
ing an appetite for breakfast by healthful exercise, 
you amuse yourself with books, pamphlets, or news- 
papers which commonly are not worth the reading. 
Yet you eat a large breakfast — four dishes of 
tea, with cream, and one or two buttered toasts, 
with slices of hung beef, which, I fancy, are not 
the things most easily digested. Soon afterwards 
you sit down to write at your desk or converse 
with persons who apply to you on business. 

Thus the time passes till one, without any kind 
of bodily exercise. But all this I could pardon, in 
regard, as you say, to your business. But what is 
your practice after dinner .? Walking in the beauti- 
ful gardens of those friends with whom you have 
dined would be the choice of a man of sense; yours 
is to be fixed down to chess, where you are found 
engaged for two or three hours ! This is your per- 
petual recreation, which is the least suitable of any 
for a sedentary man, because, instead of hastening 
the motion of the fluids, the rigid attention it 
requires helps to retard the circulation and obstruct 
internal secretions. What can be expected from 



126 PHYSIOLOGY FOR BEGINNERS 

such a course of living but a body full of impuri- 
ties, ready to fall a prey to all kinds of dangerous 
maladies, if I, the Gout, did not occasionally bring 
you relief by disturbing those impurities. Fie, then, 
Mr. Franklin ! But amid my instructions I had 
almost forgot to administer my wholesome correc- 
tions ; so take that twinge — and that ! 

Franklin. — Oh ! eh ! oh ! oh-h-h ! As much 
instruction as you please, Madam Gout, and as 
many reproaches, but pray, madam, a truce with your 
corrections ! 

Gout. — No, sir, no, I will not abate a particle of 
what is so much for your good ; therefore — 

Franklin. — Oh ! eh-h-h ! It is not fair to say 
I take no exercise, when I do very often, going out 
to dine and returning in my carriage. 

Gout. — That, of all imaginable excuses, is the 
slightest and weakest, if you allude to the motion 
of a carriage suspended on springs. By ob- 
serving the degree of heat obtained by different 
kinds of motion, we may form an estimate of the 
quantity of exercise given by each. Thus, for 
example, if you turn out to walk in winter with cold 
feet, in an hour's time you will be in a glow all over ; 
ride on horseback, the same effect will scarcely be 
perceived by four hours' round trotting ; but if you 
loll in a carriage, such as you have mentioned, you 
may travel all day and gladly enter the last inn to 
warm your feet by the fire. Flatter yourself, then, 
no longer that a half hour's airing in your car- 
riage deserves the name of exercise. Providence 



HOIV WE MOVE 127 

has appointed few to roll in carriages, while it has 
given to all a pair of legs, which are machines far 
more convenient and useful. Be grateful, then, and 
make a proper use of yours. 

Franklin. — Your reasoning grows very tiresome. 

Goui. — I stand corrected. I will be silent and 
continue my office ; take that, and that ! 

Franklin. — Oh ! oh-h ! Talk on, I pray you ! 

Gout. — No, no. I have a good number of 
twinges for you to-night and you may be sure of 
some more to-morrow. 

Franklin. — What, with such a fever ! I shall go 
distracted. Oh ! eh ! Can no one bear it for me ? 

Gout. — Ask that of your own horses ; they have 
served you faithfully. 

Franklin. — How can you so cruelly sport with 
my torments ? 

Gout. — Sport! I am very serious. I have here 
a list of offenses against your own health distinctly 
written and can justify every stroke inflicted on you. 

Franklin. — Read it, then. 

Gout. — It is too long a detail but I will briefly 
mention some particulars. 

Franklin. — Proceed. I am all attention. 

Gout. — Do you remember how often you have 
promised yourself a walk the following morning, say- 
ing at one time it was too cold, at another too warm, 
too windy, too moist, or what else you pleased, when 
in truth it was too nothing but your love of ease ? 

Franklin. — That, I confess, may have happened 
occasionally, probably ten times a year. 



128 PHYSIOLOGY FOR BEGINNERS 

Gout. — Your confession is very far short of the 
truth; the gross amount is one hundred and ninety- 
nine times. 

Franklin. — I am convinced now of the justness 
of Poor Richard's remark that " Our debts and our 
sins are always greater than we think for." 

Gout. — So it is. You philosophers are sages in 
your maxims and fools in your conduct. 

Franklin. — But do you charge among my crimes 
that I return in a carriage when I dine out } 

Gout. — Certainly ; for having been seated all 
the while, you cannot object to the fatigue of 
the day and cannot want, therefore, the relief of a 
carriage. 

Franklin. — What, then, would you have me do 
with my carriage ? 

Gout. — Burn it if you choose ; you would at least 
get heat out of it once in this way ; or, if you dislike 
that proposal, here's another for you : observe the 
poor peasants, who work in the vineyards and 
grounds about the villages of Passy ; you may find 
every day among these deserving creatures four or 
five old men and women, bent and perhaps crippled 
by weight of years and too long and too great labor. 
After a most fatiguing day these people have to 
trudge a mile or two to their smoky huts. Order 
your coachman to take them home. This is an act 
that will be good for your soul: and at the same 
time, if you return on foot, that will be good for 
your body. 

Franklin. — Ah, how tiresome you are ! 



HOW WE MOVE 129 

Gout. — Well, then, to my office ; It should not be 
forgotten that I am your physician. There ! 

Franklin. — Oh-h-h ! What a horrible physician ! 

Gout. — How ungrateful you are to say so ! Is 
it not I, who in the character of your physician, have 
saved you from palsy, dropsy, and apoplexy, one or 
other of which would have done for you long ago, 
but' for me ? 

Franklin. — Oh ! oh ; for heaven's sake leave me, 
and I promise faithfully never more to play at chess, 
but to take exercise daily, and live temperately. 

Gout. — I know you too well. You promise fair, 
but after a few months of good health you will re- 
turn to your old habits ; your fine promises will be 
forgotten like the forms of last year's clouds. But 
I leave you with an assurance of visiting you again 
at a proper time and place; for my object is your 
good, and you are sensible now that I am your real 
friend. — By Benjamin Franklin (abridged). 



CHAPTER XI 

THE COVERING OF THE BODY 

The skin, under the microscope, is seen to consist 
of two coats, the lower, or inner one, called the 
dermis ; the upper, or outer one, called the epidermis, 
or scarf skin. 

The epidermis is composed of several layers of 
cells, all of which are flattened and horny except 
the lower layers near the dermis. Near the dermis 
the cells are soft and more nearly round. The cells 
of the epidermis lying next to the dermis contain 
the coloring matter of the skin ; it varies in amount 
with different races and peoples. 

The dermis, or inner coat, is made of tough fibers 
and contains nerves and blood vessels. Beneath 
the dermis is found a layer of fat which acts as a 
cushion and prevents the heat of the body from 
escaping into the air. 

The skin protects the softer tissues beneath, and 
since it is elastic, it prevents the blood and lymph 
from collecting in the blood vessels of the lower 
part of the body. 

At the lips and nose, the skin changes into a soft 
and more delicate covering, called the mucous mem- 
brane, which extends into the body and forms the 
lining of most of its organs. You can understand 

130 



THE COVERtNG OF THE BODY 



131 



that food in the mouth or alimentary canal is not 
a part of the body and is not really in the body. 
To get into the body it is necessary to pass through 
the skin or mucous membrane. 

The epidermis may be raised up and separated 
from the dermis. This happens in the case of a 



THE UPPER I 
SKIN OR i 
EPIDERMIS ' 




UAIR eiix B 

Fig. 55. — The Skin as it would look if sliced through and viewed 
under a microscope. 

blister, when watery material or blood is forced 
between the two layers of the skin. The delicate, 
pink skin seen beneath the blister is the surface 
of the dermis, or true skin. 

The outer skin has no nerves or blood vessels. 
Boys have proved this by putting a pin through 
the outer skin, without causing the blood to flow 
as it does when a blood vessel is cut. Nor does 



132 



PHYSIOLOGY FOR BEGINNERS 



the entrance of the pin cause pain, 
if a nerve had been touched. If 




The Skin, more highly magnified than in Figure 55. The 
outer layers of the scarf skin are dead. See E.c. The 
outer skin is being built up continually from the layers 
of live cells at E.m. All the rest is dermis, or true 
skin; it is full of veins (v) and nerves (k). The nerve 
ends in a coil in a little oval body t.c. gl is a svireat 
gland; trace it to the surface. 

sand times as large a scale, or flat cell. 



as it would do 
there were no 
outer layer, we 
should suffer 
pain and in- 
jury all the 
time, from ob- 
jects touching 
the nerves or 
hurting the 
blood vessels. 
The scarf 
skin may be 
said to consist 
of a countless 
number of 
horny cells or 
scales, laid one 
upon another, 
as you might 
imagine the 
covering of a 
fish which had 
a dozen or 
more layers of 
scales. Only 
you must re- 
member that 
the scale of a 
fish is a thou- 
in the scarf skin. 



THE COVERING OF THE BODY 



133 




The outer cells of the skin are constantly wearing off 

and new ones are growing beneath, next to the true 

skin. Snakes, lizards, frogs, and insects put off the 

whole skin all at once. 

You may have found 

the skin of a snake 

lying on the ground 

after it had been shed. 

Birds moult, or lose 

their feathers, one at 

a time, and new ones p,q 

come in their places. TheSkuUoftheTortoiseischieflyofepidermis, 
• ^, , . , . supported by the ribs. 

We shed our skms 

in such tiny, powdery scales that we do not notice 
them. If one rubs hard while taking a bath, 
the epidermis sometimes peels off in little white 
rolls. The skin of the scalp sometimes becomes 
coated with dandruff. There is usually some dan- 
druff, even on the healthiest and cleanest scalp. Yet 
careful and cleanly persons by 
brushing the scalp prevent it 
from becoming coated with dan- 
druff. 

The hair and nails belong to 
the skin. The hair grows from 
little sacs or bags in the skin. 
Fig. 58.— Two Hairs with ^^d the uails grow from grooves 

their Oil Glands. r 1 , • 1 i • -r-? 1 • 

or folds m the skm. Ihe hair 
is made of scales like those of the scarf skin. 
Some of the cells contain pigment, or coloring 
matter, which gives them their color. This pig- 




134 PHYSIOLOGY FOR BEGINNERS 

ment ceases to form in the hair of very old persons. 
To the roots of the hair muscle fibers are attached, 
enabling the hair to stand on end. You may have 
seen a cat bristle up when a dog came near. 

Each hair is oiled by two little glands at its side. 
The oil which they furnish is a natural dressing for 
the hair. This oil softens the skin and also keeps the 
hair soft and glossy. Well-kept hair is one of the 
most beautiful ornaments of the body. 

The oil glands on the nose are relatively very 
large, although the hairs on the nose are very small. 
Sometimes the openings of the glands become swol- 
len by the oil and dirt which fill them. When 
in this condition, they are called blackheads. The 
use of face powder frequently causes blackheads. 
By keeping the face clean, the swollen openings 
gradually decrease to their natural size. 

Sometimes the face and hands chap, that is, the 
skin becomes hard, and crocks for the want of oil. 
Some other oil or cream is put on to fill the place 
of nature's hair oil. Thorough brushing of the hair 
makes the glands more active, and the hair glossy 
and smooth. A brush which irritates the scalp 
should never be used. 

" Long and thick hair is such a great beauty, that 
it is curious why more girls do not take pains to 
obtain it. Cleanliness and frequent brushing are the 
best ways to get good, long, and thick hair. The 
people in different countries have different ideas 
about hair. The women in Egypt and the Eastern 
lands do not think it modest or becoming to show 



THE COVERING OF THE BODY 



I3S 




Fig. 59. — Sweat 
Glands. 



any hair at all, and they cover their heads and ears 

with long draping cloths, while the ladies of Japan 

undergo the most elaborate hair-dress- 
ing. Indeed, the process takes so long 

a time that it is not usually done more 

than once or twice a week. Each hair 

is brushed and pomatumed and gummed 

until it lies in its proper place. To rest 

the head on a pillow would upset it all, 

so the Japanese women forego pillows, 

and sleep resting the head on small 

neck-rests, which allow the hair to 

remain untouched. Is it not a strange 

custom .? " — Mrs. S. A. Barnett. 
There is another kind of glands 
called sweat glands. The perspira- 
tion, or sweat, is collected by the 
glands. It is not pure water, but 
contains impurities which would 
harm the body if retained. The 
openings of the sweat glands are 
called pores. Besides removing 
impurities from the body, another 
function of the sweat is to cool the 
body. When the weather is hot, 
openings of the sweat qj. ^heu wc work hard, the skin 

glands. 

becomes flushed with blood, and 
the sweat flows so freely that it stands on the skin 
in little drops. We are always perspiring whether 
we are warm or not, although we may not see the 
sweat on account of the smallness of the quantity. 




Fig. 60. 
Magnified view of the Skin, 
showing the pores, or 



136 



PHYSIOLOGY FOR BEGINNERS 



The evaporation of the sweat from our bodies cools 
them. This cooling of the surface also cools the 
blood, because a great amount of it is brought to the 
surface of the body. The body is sometimes cooled 
by damp and wet clothing. If you are caught in the 
rain, the dampness will do no harm, so long as you 
keep moving, and keep the body warm by exercise. 
Damp clothes or shoes should be 
changed for dry ones as soon as 
possible. 

The nails protect the ends of the 
fingers and toes. They are like 
beautiful pink shells if they are kept 
clean. Nails should be cut regularly. 
Some people have the habit of biting 
the nails. This is a very bad habit ; 
it makes the fingers not only sore, 
but stumpy at the ends, so that it is 
impossible for them to do the deli- 
cate work for which they are in- 
tended. The nails have a natural 
polish and should not be scraped 
with a knife. 

Impurities may enter the body 
through the skin. Cheap toilet soaps, perfumed to 
hide the rancid odor, are sometimes made from the 
fat of diseased animals. By use of such soaps, im- 
purities may be taken into the body through the 
pores of the skin. Sometimes soldiers, in order to 
shirk duty, put a piece of tobacco in each armpit. 
The poison that is absorbed reaches their nerves ; 




Fig. 6l. — Flax with 
Blossoms. 

Linen, suitable for 
clothing in warm 
climates, is made 
from the stems of 
this plant. 



THE COVERING OF THE BODY 



m 



they become sick, and the surgeon sends them to 
the hospital. 

Painters who do not keep their hands clean 
suffer at times from what is called painters' colic, 
caused by the lead that is absorbed through the 
skin. Hair dyes and face powders, or even stock- 
ings that are poorly dyed, may injure the skin. Cos- 




FlG. 62. — Twig of Mulberry, and Eggs, Caterpillar, Cocoon, and Chrysalis. 
Moth, and Silkworm that spins sill;, a fabric warmer than cotton but 
cooler than wool. 



metics sometimes cause dark spots or sore places on 
the cheek, or pimples in the face. Nothing but 
pure blood and good health can give a clear skin 
and rosy cheeks. It has been said that "beauty is 
but skin deep." Explain why this saying is false. 

It is one of the sad things in life to see the roses 
fade from the cheeks of healthy and happy boys and 



138 



PHYSIOLOGY FOR BEGINNERS 



girls because they cannot or will not live in the 
pure air, take enough exercise, and dress properly. 

The pale and sallow skin of the cigarette smoker 
shows what havoc the poison makes with health. 
The odor of tobacco is continually passing through 
the skin to the clothes of the user, until they be- 
come so filled with it that they may even be offen- 
sive to persons passing along the streets. 

Care of the Skin. — The first condition for keep- 
ing the body clean is to live in a clean house. 
Every child should learn to shun dirt, and to un- 
derstand the danger that lurks in it» He should 

learn to remove dirt, not to 
hide it. If, after a room is 






Fig. 63. 



Fig. 64. 



Figs. 63-64. — Natural Feet and Deformed Feet. Should the shoe be longer 
in the middle or on one side ? 

swept, the dust is allowed to settle upon the furni- 
ture and the tops of the picture frames, the posi- 
tion of the dirt has only been shifted from one place 
to another. It might as well have been left upon the 
floor. Rooms should be thoroughly aired while they 
are being swept and for a long time after, in order 
to get rid of the dust. All unnecessary things 



THE COVERING OF THE BODY 



139 



should be removed from a room and stored in a 
proper place until needed. Otherwise they simply 
become receptacles to catch and hold dust. 

The bath should be taken in a warm room. We 
should try to get used to cool baths and a dash of 




Fig. 65. — Part of a Cotton Plant, showing leaves, flower; closed boll and 
open boll, or ripe fruit. The seeds supply valuable oil, and the hairs on the 
seeds furnish a greater amount of material for clothing than is obtained 
from any other source. 

cold water at the end of the bath. The skin should 
be rubbed until it glows. All persons cannot safely 
remain in the bath for the same length of time. It 
is not safe for weak people to take very hot or very 
cold baths. It is best to take a warm bath in the 



I40 PHYSIOLOGY FOR BEGINNERS 

evening just before going to bed. If it is taken 
just before going out of doors, a cold is likely to 
follow — especially if the dash of cold water is 
omitted at the end. It is best to take a cold bath 
upon rising in the morning. 

Exposure after a warm bath, or cooling off sud- 
denly when one is perspiring, may cause a cold by 
stopping the perspiration for a considerable time. 
A bath should not be taken just after eating. 
When bathing, one should not stay in the water 
until he is chilled. 



LIFE IN THE VILLAGE OF X 

A few years ago the village of X could be seen 
nestling among the trees on the banks of a river 
which flows through one of our great states. Its 
people were intelligent, simple-hearted, and prosper- 
ous. Soon a railroad was built through the village, 
which began to grow. The stores, which had been 
few, increased in numbers, and factories were built 
upon the river bank. 

The traveling men who came to sell goods to the 
merchants told the clerks and other young men 
that their town would never prosper, and they them- 
selves would never amount to anything, unless they 
dressed according to the fashions of London and 
Paris. Thereupon, the young men ordered hats, 
shoes, and clothes of the kind that the traveling 
men wore and had for sale. Now it seems that there 
were many dandies in Paris who had nothing to 



THE COVERING OF THE BODY 141 

do but to waste the money and tarnish the good 
names that their fathers had left them. • They idled, 
stiffened their necks, and held their heads high 
because of what their fathers had done. Their 
necks became very thin and lean, so they had col- 
lars made which came up nearly to their ears and 
hid their necks. The young men in the village of 
X soon had their stout and manly necks incased in 
collars of the same height ; but they led busy lives 
and could not hold their necks stiff enough to keep 
from rasping them upon their collars. From over- 
protection, their necks became so sensitive that they 
had many colds, coughs, and lung troubles. It was 
much warmer in X than in Paris, but they clung 
to their tall collars and sweltered all the summer 
through. The gay young men of Paris changed 
the shape of their hats and the cut of their coats 
quite often, for they had little to think of but 
clothes. When the baker and butcher boys of Paris, 
and the clerks and other young men of the village 
of X, adopted the new fashions, the dandies at 
once changed again, for they could not bear to 
see so common men dressing as they did. The 
clerks could not bear to dress any other way, 
because they thought that was the only way to live ; 
for so the drummers who wanted to sell them the 
clothes had told them. The rich young men in 
Paris wore tight shoes and drove in their carriages ; 
the young men in X wore tight shoes and 
trudged. Corns and bunions came, which caused 
them to suffer cruel tortures. 



142 PHYSIOLOGY FOR BEGINNERS 

Some of the maidens in the village of X went off 
to boarding school, where they learned to paint pretty 
blue roses and other flowers and to repeat a few 
sentences in French. The most important thing 
they learned was to make their clothes like the 
pictures in the monthly Excruciator and another 
magazine called La Mode de Paris. The sisters of 
the millionaire dandies of Paris and London wore 
their dresses very long to display the fine fabric. 
When they went out, they had only to step into 
their carriages standing under the covered drive- 
way of their mansions. The young ladies in the 
village of X at once had their skirts made of equal 
length and carried them until their arms ached ; and 
then they dropped them and dragged them through 
the filth of the street until their backs ached. Later 
they hung the soiled skirts in the closets of their 
homes. The rich lady in the city would have her 
measures taken by the corset maker, who for ten 
dollars would make a corset to fit her form ; the 
maiden in the village would buy a cheap, ready-made 
corset for two dollars, and fit her form to it. The 
ladies in Paris ruined their complexions by much 
indoor life and overeating and had to cover their 
dingy faces with powder and paint; so the maidens 
in the village covered their smooth, rosy skins with 
cosmetics and made them dingy too. The city 
-ladies, before going to balls, would have their 
hairdressers come, and while reclining upon easy- 
chairs, their hair would be done into many a curl 
and ringlet. The village maidens struggled for 



THE COVERING OF THE BODY 143 

an hour, until their arms ached with the tedious 
crimping. When with tired hands and hair 
scorched by hot irons, they went to parties, they 
were too tired to enjoy themselves, although most 
of them had strength enough left for their most 
popular amusement, a game called, " Simon says 
wigwag." The rich ladies had many fine hats. 
They had also ladies' maids to care for their finery 
when they went on journeys ; the maidens in the 
village of X (is it a long way from here ?) tried with 
cheaper material to make hats equally gorgeous, 
but when they went on journeys they lugged their 
bandboxes along with their own hands. 

A traveler in Paris told the Countess of B. about 
these doings and she laughed a silvery little laugh, 
which she had been taught at a fashionable school, 
and said, " Poor, silly things ! " The fine ladies gave 
away their dresses and had others made each season 
in a new fashion ; the girls of the village could not 
afford to waste good cloth, so with much time and 
labor and contriving, they made over their dresses ; 
or at first they often made them of flimsy material 
which soon wore out, resulting in waste of time and 
labor. The fine ladies cut off their breath with 
tight clothes, and while dressed up, never made any 
exertion even so much as to call a servant, merely 
pressing the button of the electric bell when one 
was needed. The young ladies in the village of 
X cut off half their breath of life, talked in strained 
tones to forty school children, sat at sewing machine 
or typewriter, or stood behind a counter all day, or 



144 PHYSIOLOGY FOR BEGINNERS 

did some other useful thing, such as a fine lady 
seldom does, so they became haggard and broken 
before their time. A lady visited the town and gave 
a talk to the ladies' club on artistic, healthful dress, 
and showed how tight clothing makes the muscles 
weak and flabby, and causes the human figure to lose 
all its natural gracefulness; but she failed to con- 
vince the women of X. 

An artist who was painting the beautiful scenes 
near the village perceived the folly and ugliness of 
the prevailing styles, and wrote a letter to the weekly 
newspaper, in which he said that nothing shows lack 
of refinement so much as affectation of tone or voice, 
or imitation of the ways of others; that people of 
self-respect live their own true lives, and do not 
lose health and happiness copying other people ; 
that Americans can have as much taste and in- 
dividuality as the people of any other country ; that 
when it is the style to wear "cart-wheel" hats, the 
woman with a small face should not do so, or her 
face would look like a bullet, as he uniquely ex- 
pressed it; that a woman with a very large head 
should not adopt the fashion when hats become the 
size of saucers, or her head would seem as large as a 
water bucket ; that a woman with a long nose who 
wears her hat on the back of her head because others 
do so, makes it seem like a day's journey from the 
hat to the end of her nose, and that a pug-nosed 
woman who wears her hat low on the forehead, 
makes her nose seem to point skyward still more. 
The artist said, too, that fat women who wear tight 



THE COVERING OF THE BODY 145 

dresses simply show how dumpy they are ; that thin 
ones who wear them lead kind-hearted friends to 
think they need to go to the hospital ; and that 
neither a stovepipe nor a stovepot is a good model 
for a man's hat, etc. 

But the artist's words had no effect upon the 
fashionable girls and young men whose only 
idea was to make themselves conspicuous by 
coming out in every new fashion, however ugly 
or unhealthful. But their conduct amused the few 
old-fashioned girls of the village, who were ruddy- 
faced and strong from leading simple, active lives. 
They made their dresses of fine, durable cloth which 
lasted several years, and only laughed when the 
other girls told them they looked as if they had come 
out of the ark. These old-fashioned girls and their 
brothers still sang the sweet old songs instead of 
the ragtime tunes that the stylish boys and girls 
sang ; they still read the beautiful old books instead 
of the latest novels that the others read. When the 
old-fashioned girls married, they had strength and 
health that made them good housekeepers and 
cheerful wives. On the other hand, the stylish girls 
at twenty-five looked like old women ; they were 
always having aches and pains, and when the hus- 
band of one of them saw the number of bottles of 
medicine on the shelves, it seemed as if he lived 
in a drug store instead of a home. The women of 
style said they were sick because God intended 
woman to be weak and sickly. 

Of course the rich idlers of Paris and London 



146 PHYSIOLOGY FOR BEGINNERS 

were slow to believe the scientific proofs of the 
poisonous effect of alcoholic drinks and they still 
used such liquors. When the village gave a public 
banquet in honor of a senator who visited there, the 
stylish young men said it would not be fine enough 
without champagne. The people of temperance 
principles turned their glasses down when the cham- 
pagne was passed around. It was a mixture of even 
poorer stuff than fermented grapes ; but the young 
men were happy, for they thought it the same as 
that drunk by the people they were trying to ape. 

Some of the young men of the town injured their 
health much more by indulgence in cigarettes and 
beer than the girls hurt themselves by tight clothes 
and lack of exercise. Many of the men went in 
vain hope to inebriate asylums, while the women 
visited noted surgeons in the large cities, hoping to 
be cured of chronic ill-health. Thus much money 
went out of the town and with intemperance and 
doctors' bills and drug bills, and quantities of goods 
in the stores that were out of style, the people had 
a hard struggle instead of prospering as the com- 
mercial travelers had promised some years before 
when the village was small. But the people of 
X had grown wiser as well as older. They 
taught their children that being a lady or a gentle- 
man does not consist in wearing fine clothes or in 
copying the clothes and habits of others, but in 
being modest and gentle and honorable ; that health 
and happiness come, not from pride and display, 
' but from simplicity and truth. 



CHAPTER XII 

THE SPECIAL SENSES 

There are five ways by which we may receive 
messages from the world about us: Through — 
I. The eye, sensitive to light; 2. The ear, to 
sound; 3. The nose, to smell; 4. The tongue, to 
taste ; 5. The skin, to touch, heat, and cold. 

No organ can perform the function of another 
organ ; the eye cannot hear, the nose cannot taste, 
the ear cannot see. Pressure on the eye may cause 
a man to see forms, and a sudden jar or jolt may 
make him "see stars," because the nerve of sight 
feels pressure or jars. In olden times men counted 
seven special senses instead of five ; the two addi- 
tional senses were the " voice " and " animation," or 
life. The voice is not a sense, but a result of mus- 
cular action, and as to animation, or life, no one 
knows what it is. Hence we may say we have five 
special senses. 

We have also a general sense which acts through 
nerves that come from the blood vessels, lungs, and 
digestive organs, and tells us the condition of our 
own bodies. It is by the general sense that we 
" feel well " or " feel ill." Beyond this, we are not 
usually conscious of digestion, breathing, or the cir- 
culation of the blood. 

H7 



148 PHYSIOLOGY FOR BEGINNERS 

Pain is the result of any one of the sense organs 
being too strongly stimulated. Pain is very useful 
to us, for it warns us when to take care of ourselves. 

TOUCH 

The true skin projects into the epidermis, or 
scarf skin, forming tiny hillocks or ridges. (Fig. 56.) 
In most of these projections, small oval bodies, 
known as touch corpuscles, are found. A nerve 
fiber ends in each of the corpuscles. By means of 
these nerve fibers in the skin, we feel the sensation 
of touch and pressure, heat and cold. By touch we 
can tell whether an object is hard or soft, rough 
or smooth, etc. In what part of the body are the 
nerves of touch very numerous ? (Chapter II.) The 
ridges in the palm and fingers show where rows 
of projections containing the touch corpuscles are 
found. 

The muscular sense consists of the special sense 
of touch and the general sense. By means of pres- 
sure on the skin and on the sensory nerves which 
end in the joints and muscles, we learn the position 
of the body and limbs and how much effort our 
muscles are making. 

TASTE 

The surface of the tongue is roughened by 
numerous little projections. In some of them are 
found the ends of the fibers of the nerves of taste. 
Things taste (i) sweet, (2) sour, (3) bitter, or 
(4) salt. Flavors are not detected by the sense of 



THE SPECIAL SEJVSES 149 

taste, but by the sense of smell located in the nose ; 
hence a cold in the head destroys the flavors of 
food we eat. An apple seems without flavor if you 
hold your nose when you bite it, although it still 
tastes sweet. 

Substances must be dissolved in a liquid before 
they can be tasted, because only liquids can affect 
the nerves of taste. Soluble substances not in a 
state of solution are readily dissolved by the saliva. 
The sweetness of sugar can be tasted if there is 
only one part of sugar to 83 parts of water, while the 
deadly poison called strychnine can be tasted, as 
bitter, if there is only one part of strychnine in 
2,000,000 parts of water. Coffee has a bitter taste. 
The first man who used it could not have had any 
respect for his natural instincts. Sometimes chil- 
dren, by putting milk and sugar into coffee in order 
to hide its taste and deceive the faithful tongue, 
learn to like it; but they should never drink it. 
Tea is no better than coffee. Many grown people 
use tea and coffee and seem to escape evil effects by 
using them moderately. On the other hand, many 
people find by ceasing to drink tea and coffee, that 
headaches, indigestion, and other troubles are cured 
at once. 

Few people like to drink pure coffee. In some 
sections of the United States and in many countries 
of South America, there are coffee topers who are 
enslaved by its use. The Brazilian topers, who 
drink twenty to thirty cups daily, say that 
coffee, to be good, must be as black as night, as 



I so PHYSIOLOGY FOR BEGINNERS 

bitter as gall, and as hot as fire. They drink it for 
its effect, not for. its taste. 



SMELL 

The nose is divided in the middle by a partition 
of bone and gristle, making the two nostrils. The 
floor of the nose and the roof of the mouth are 
formed by one partition called the hard palate. 
The floor of the skull is pierced in front by a 
number of small holes through which branches of 
the nerve of smell pass into the nose from the brain. 

We breathe chiefly through the lower part of the 
nose and smell with the upper part. By sniffing, 
air is drawn into the upper part of the nose and an 
odor is more easily detected. In many of the lower 
animals the sense of smell is far more sensitive 
than in man. Give an instance that shows how 
wonderfully acute smell is in lower animals. The 
sense of smell in some persons is so injured by 
catarrh that they have almost lost it. Civilized men 
do not have so acute a sense of smell as savages ; 
this is because the former make very little use of 
this sense in selecting their food. 

How we Smell. — The perfume of a flower or the 
odor of any substance which we smell is caused by 
tiny particles of the object floating through the air 
to the nose. These particles are too small to be 
seen even with a microscope, but they touch the 
nerves of smell and give us the odor. The sense of 
smell not only enables us to choose good food and 



THE SPECIAL SENSES 



151 



to avoid spoiled food, but it also warns us to keep 
away from unheal thful and unpleasant places. 



SIGHT 



Touch, taste, and smell bring us in contact with 
the bodies that we perceive through these senses. 
But the senses of sight and hearing give us knowl- 
edge of things at a distance as well as of those at 



Sdet'Olic Coat 

2. The Colouied Coat- 

{Choroid Coat). , 

3, The Network Coat 

{Betinal. 




7. The Horny Coat (Coriwoi. 
8 The Water Chamber 

{Aqutms Humour). 
10 The Round "Window 

{pupm. , 

9. The Curtain (Irui). 



'rureous Humour . (Crystalhne Ims). 

Fig. 66. — Section of Eyeball, showing its two chambers, etc. 

hand. The sense of sight enables us to look at a 
thing within a few inches of our faces one second, 
and at something else, miles away, the next second. 
There are things so far away that nobody has ever 
measured the distance, yet we can see them. What 
are they ? 

The eyeball is set into a deep bony socket. 
There is a cushion of fat between the eye and the 
hard wall of the socket ; this cushion sinks in when 



152 PHYSIOLOGY FOR BEGINNERS 

the eye is struck, so that the eye may not be injured. 
A large nerve, called the optic nerve, goes from 
the brain to the eyeball, passing through an opening 
in the- back part of the socket. 

The eyeball is tough and almost round. Its 
tough outer wall or covering is lined with delicate 
membranes. Most of the wall is white, but the 
front part of the wall, called the cornea, is colorless 
like glass, and bulges out a little. If you look- for 
it in a mirror, you cannot see it well in your own 
eye. If you look at the side of another person's 




Fig. 67. — Showing how the Lens brings the Rays of Light from 
an object to a focus on the retina and forms a small image. 

face, you can see the transparent cornea bulging 
out in the front part of the eyeball. Behind the 
cornea is a space filled with a watery fluid, form- 
ing the front chamber of the eye. At the back of 
this chamber hangs a curtain called the iris 
(meaning rainbow), which gives the color to the eye. 
The color of the iris is due to the pigment it contains. 
Persons with much pigment in the skin, making it 
dark, usually have dark eyes also. In the center 
of the iris is a hole called the pupil. 

When we go from a dark room into a lighted 
room, the eyes are pained by the entrance of too 




Fig. 68. 



THE SPECIAL SENSES 1 53 

much light. Soon the iris contracts around the 
pupil, which becomes smaller and smaller, until it 
shuts out enough' light to cause the pain to cease. 
In going from a light 
room into a dark room, 
one is unable to see 
anything at first. By 
and by the pupil of the 
eye dilates, until it ad- 
mits sufficient light to 
enable one to see things 
clearly. 

Just behind the iris 
and the pupil is a transparent rounded body called 
the crystalline lens. This lens brings the rays of 
light to a point, or focus, in the back of the eye, so 
that a picture is formed. There is a chamber in the 
eye behind the lens, much larger than the chamber 
in front of the lens. 

This chamber contains a clear, jellylike substance. 
The optic nerve spreads out on the lining of this 

chamber. - Its lining is 

called the retina (ret-i-na). 

Upon the retina the light 

is brought to a focus, 

forming pictures which 

remain for a moment and 

then gradually fade away. 

A bright light looked at for a short time may still 

be seen as a dim image for a few seconds after 

the eyes are closed and the head turned away. 





154 PHYSIOLOGY FOR BEGINNERS 

For the same reason a stick with a glowing coal 
at one end, whirled around at night, looks like a 
bright ring. 

Without the optic nerve to carry the impression 
to the brain, we could really see nothing. Although 
the picture might be made in the eye, we could 
not see it unless the brain could get the message. 

Nearsightedness is caused by the eyeball being too 
long, the light coming to a focus before it reaches 
the retina. (Fig. 68.) Farsightedness is caused by 
the eyeball being flattened slightly, the light coming 
to a focus behind the retina. (Fig. 69.) The figures 
show the two forms of eyeball, and the kind of 
lenses used in glasses for each kind of eyes. 

Care of the Eye. — We should be careful to have 
our work fifteen inches or more from the eye. If 
we put the head down close to the work, we are in 
danger of becoming nearsighted. Fine print and fine 
sewing or embroidery are bad for the sight, because 
we are apt to bring them too near to the eyes. 

The light should not shine directly on the eyes. 
We should never gaze at a bright light. If the eyes 
feel in the least tired, we should rest them. The 
light should come over the shoulder when we are 
reading. When we are writing, the light should 
come over the left shoulder. We should not rub 
the eyes. We should not read when lying down, or 
in the twilight, or when recovering from any sick- 
ness, or for a long time after recovering from scarlet 
fever or measles. The use of tobacco may seriously 
injure the sight. 



THE SPECIAL SENSES 



ISS 



THE HEARING 

Why is it almost as great a misfortune to be deaf 
from birth as to be blind? (What usually accom- 
panies deafness ?) 

The ear has three divisions, called the outer, 
middle, and inner ear. We can see the part of the 
outer ear that is outside of the skull. It is com- 




FiG. 70. — The Ear. 



posed of cartilage and is formed to catch sound. 
The outer ear continues inward in the form of a 
tube, which is about an inch long. Across the 
inner end of the tube a delicate membrane is 
stretched. It is the drum skin, although often 
called the drum. The middle ear is the drum; it 
is a cavity containing air, situated just beyond the 
drum skin. Three of the tiniest bones in the body, 




156 PHYSIOLOGY FOR BEGINNERS 

called the hammer, anvil, and stirrup, stretch acrqss 

the drum cavity from the drum skin to the inner ear. 

The inner ear is a bony cavity made up of small 

spiral tubes and loops, hollowed out in the solid 

- bone. This complex cavity 
is filled with a liquid. The 
nerve of hearing passes 
from the brain to the inner 
ear and its many fibers come 
to an end in this cavity. 
'■L-3»*3 Sound travels in waves 

that follow one another 

Fig. 71. — The Three Bones of the .„ ^^^. . 

Ear (magiiihe I four times). rapidly. When you throw 

The Hammer is more lilce a club than a StOUe in a pOnd, yOU See 

a hammer; the anvil is something p;^p„1ar wa Vf^c cf artrnfr frnm 
like an anvil; while the third bone ClTCUiar WaVCS Startmg trom 

is as neat a httle stirrup as one the point whcre the StOUe 
could wish to see. '■ 

struck. Sound waves are 
in the air like spheres instead of like circles, and 
spread in all directions from the source of the 
sound. Reaching the ear, the waves pass through 
the canal of the outer ear and set the elastic drum 
skin to shaking, just as a drum vibrates when it 
is struck. The three little bones are set to vibrat- 
ing in turn, and the last of the three bones, called 
the stirrup, sets in motion the liquid of the inner 
ear. This liquid makes an impression upon the 
ends of the nerve fibers. The nerve of hearing 
{A, Fig. 70) carries a nerve current (not a sound 
wave) to the brain. 

A tube leads from the middle ear and opens into 
the throat behind the nasal passages. {R, Fig. 70.) 



THE SPECIAL SENSES 157 

A chronic cold in the. head may affect the ear 
through this tube and injure the hearing. 

Care of the Ears. — Cold water should never be 
put into the ear. Diving in deep water or bathing 
among the breakers sometimes injures the ears. If 
there is water in the ears after bathing, the head 
should be held to one side and the water allowed to 
run out. Earache is sometimes caused by sleeping 
where the wind may blow upon the ears. Putting 
cotton into the ears to protect them from the cold 
only makes them more sensitive. Never pick the 
ears, as by so doing the drum skin may be injured. 
The tube of the outer ear secretes a yellow, bitter 
wax, which prevents insects from entering the ear. 



CHAPTER XIII 

THE CARE OF THE HEALTH 

Is it more difficult to understand physiology or to 
practice the laws of health after you have learned 
them ? It has been said that the Golden Rule, if 
followed, would cure all the evil and selfishness in 
the world; likewise a few simple laws of health, if 
followed, would prevent most of the sickness and 
suffering. 

Perhaps you have known persons who believed 
in oxygen as the greatest need of the body, yet who 
kept their rooms tightly closed ; who believed in 
deep breathing, yet bound the ribs with tight 
clothing. 

Teachers have been known to give very interest- 
ing lessons on the benefit of fresh air, while at that 
very time the schoolroom was entirely without ven- 
tilation, its air being so foul that a newcomer would 
find the odor sickening. 

Most people know that stimulants deceive ; the 
Bible said many hundreds of years ago that " wine is 
a mocker, strong drink is raging," but stimulants are 
still one of the saddest of all curses of the human 
race. Some men drink in winter to keep out the 
cold. The same men drink in summer in order 

158 



THE CARE OF THE HEALTH 159 

to bear the heat. People drink in some coun- 
tries because the cHmate is so moist, and in others 
because it is so dry. They give every reason for 
drinking but the true one, which is that they wish 
to rob themselves of to-morrow's strength before 
to-morrow comes. 

Many persons care so little for health that they 
are far more likely to live properly if they think that 
by so doing they will improve their looks, than they 
are from the knowledge that right living will make 
them healthier and stronger and more useful in the 
world. 

People know that work with the muscles is neces- 
sary to keep the blood fresh and pure, yet from 
indolence or for fear of soiling their clothes or for 
other trivial reasons, many neglect it entirely. 

People know also that those who work little should 
eat little, yet they eat what they like and as much as 
they like. They know that tobacco is injurious, yet 
cannot give it up. 

They injure their eyesight and nerves while 
striving after knowledge without wisdom, by bend- 
ing over books. They exhaust themselves by worry, 
while they know that such a course injures them. 

They lose their health and become invalids and 
then go from one doctor to another, and take one 
drug after another in vain. Thus they act as if they 
believe there is more health in powders and pills 
than in sunshine, useful labor, pure air, simple food, 
and a calm and contented mind ; yet these natural 
remedies would probably restore them to health. 



l6o PHYSIOLOGY FOR BEGINNERS 

We should be careful that we do not deceive our- 
selves by saying that we believe the truth when we 
do not believe it. 

CIGARETTES 

Some boy may say : " I do not believe that tobacco 
is very harmful. My grandfather uses tobacco and 
it has not killed him. He is eighty years old and 
he still smokes cigars or a pipe every day." But 
this boy's grandfather did not begin smoking when 
a boy and thus stunt his growth, but waited until 
he was a man ; moreover, he certainly did not smoke 
cigarettes. If, instead of smoking a pipe or a cigar 
once or twice a day, he had smoked dozens of cigar- 
ettes every day, he would have died long ago. As it 
is, he undoubtedly would have been a still stronger 
and sounder man if he had never used the poisorw 

Since no one can say any good of cigarettes, why 
is it that some boys learn to use them ? There was 
a man that lived some years ago who taught that 
people are akin to monkeys and apes; this man 
might have said that boys learn to smoke just by 
imitating or aping other boys, but the author will 
try to give the true reason. The boys that have 
already learned to smoke cigarettes want company in 
their evil habit and hence they persuade other boys 
to smoke. Again, finding themselves slaves to a 
little cigarette only half as big as the little finger, 
they do not wish other boys to be strong and free 
while they are nervous and weak. Besides, the more 
boys that smoke, the more likely they are to get free 



THE CARE OF THE HEALTH 



l6l 



cigarettes if they are out of money for a time. For 
it is no slight thing for a cigarette smoker to be com- 
pelled to miss taking a smoke. Some of them can 
hardly wait from one recess to another, so strong is 



the craving. 



In order to keep the smokers away from the other 
pupils, a principal once made a rule that boys could 




From the Cosmopolitan. 

Fig. 72. — The Elephant at Work. 

The elephanf is an intelligent animal. Once a man by way of a joke gave an 
elephant some tobacco. It was chewed a short time and rejected in disgust. 
Some months afterwards the man passed by again. The elephant remembered 
him, and, filling his trunk with dirty water from a pail near by, he gave the man 
a ducking. 

smoke only in one corner of the school ground. 
The poor cigarette smokers had to stay there at 
recess nearly all the time. 

There was a boy named Tom B. whom a teacher 
tried to prevent from smoking, for she noticed that he 
could not keep his mind on his books long enough 
to study and that he was lean and pale. Tom saw 



1 62 PHYSIOLOGY FOR BEGINNERS 

that she was his true friend and he knew that 
cigarettes were ruining his happiness, so he prom- 
ised her to give them up. It was a terrible struggle ; 
his eyes glittered, he was fidgety and uneasy all the 
time. After a while he got over some of the bad 
effects of smoking and began to get stronger. But 
one day, soon after recess, he asked to be allowed to 
go out. The teacher noticed a very eager look on 
his face, and she stepped out into the hall and looked 
through the window ; there was Tom, smoking again. 
The little cigarette had conquered. Tom had fallen, 
and he thought he did not have the strength to try 
again. Of course this was a mistake ; if he had been 
willing to undergo the suffering, he could 'have con- 
quered in the end. He soon stopped school, for he 
could make no progress in his books, and his life, 
like that of many cigarette smokers, was a failure. 



GOOD TASTE AND HEALTHFULNESS IN DRESS 

It is right that a girl should spend some time and 
thought upon her clothes and that they should be 
pretty and becoming; it is also right that she should 
take care that they do not deform her by their weight 
or tightness, or add to the work of the heart and 
lungs. The most healthful dress is not only the 
most becoming, but it preserves the good looks 
of the wearer. Unhealthful dress deforms the body 
and causes the loss of its natural grace. The 
human form is by nature one of the most graceful 
in the whole animal kingdom and has been called 



THE CARE OF THE HEALTH 1 63 

the " human form divine " ; we are told that man 
was made in the image of God. Anything that 
prevents free and easy movement or interferes with 
any of the organs, soon causes the body to lose 
health as well as grace. 

God has made the waist the most movable part 
of the body. There the walls of the body swing 
gently in and out in natural, perfect breathing. The 
heart and liver and other vital organs partake of the 
benefits resulting from this freedom of motion. But 
because the waist is most free to move, it can be 
most easily deformed. Unfortunately, advantage 
is too often taken of its very perfection to bring 
about deformity. 

The injury comes from stopping the motion of 
the waist in breathing. This injury is inflicted 
when, the skirts are suspended from bands tied 
around the waist. The practice usually begins at 
the age when the girl is growing most rapidly ; thus 
development at the waist is stopped. The organs 
there cease growing or grow down out of place. 

If, by natural growth, a girl's waist would have 
reached the size of twenty-eight inches, do you think 
she can be strong and well when a woman if her 
waist measure is only twenty-four inches, the same 
size it was when she was but twelve years of age ? 
Read again the allegory called " The Architect and 
his Two Friends" (p. 64). 

If elastic bands are used to support the stockings, 
they should be carefully adjusted so as to be barely 
tight enough to do so. 



1 64 



PHYSIOLOGY FOR BEGINNERS 



Some people act as if they think God knows 
how little boys should grow to be men, but that 
it is left for the fashion makers to find out how 

Instead of sup- 



little girls should grow into women 




Frmii ll[c Cti^iiiiipolitan. 

Fig. 73. — Under the Big Guns of the Flagship Olyiiipia. 

In this ship Admiral Dewey won the battle of Manila Bay. Notice that the 
admiral wears a white uniform. In a hot climate like that of the Philippines, 
white clothing is the most healtiiful because it reflects the rays of the sun. 

porting the clothes from the strong, bony, muscular 
shoulders, the most delicate part of the body is 
selected for the purpose. If they try to do better, 
such people get deceptive " health waists," which 



THE CARE OF THE HEALTH 1 65 

they fasten so tight around the waist that the shoul- 
der straps are loose and support no weight at all. 
If the mother says to her daughter, "My dear, I 
think your dress is too tight," the girl may reply, 
" No, it cannot be, for see ! when I send out my 
breath, I can get my hand beneath my belt." Of 
course she can get her hand beneath her belt. If she 
should draw the belt to the smallest size of the waist 
when the breath is out, the breath would scarcely 
come back and she would be in danger of smother- 
ing. If the belt or skirt is tight enough to be held 
in place by the pressure, it is interfering with her 
breathing and with free and perfect growth. If she 
takes exercise or plays active games in this condi- 
tion, she may be injured instead of being benefited. 
Every boy and girl should have, as the standard 
of growth, the fullest development that the " human 
form divine" is capable of reaching with perfect 
freedom and healthful living; and both boys and 
girls should so live as to reach their ideals. 

THE LIVING TEMPLE 

Not in the world of light alone, 
Where God has builtihis blazing throne, 
Nor yet alone on earth below, 
With belted seas that come and go. 
And endless isles of sunlit green. 
Is all thy Maker's glory seen ; 
Look in upon thy wondrous frame, 
Eternal wisdom still the same! 



l66 PHYSIOLOGY FOR BEGINIVERS 

The smooth, soft air, with pulselike waves, 
;2i Flows murmuring through its hidden caves, 
Whose streams of brightening purple rush. 
Fired with a new and livelier blush, 
While all their burden of decay 
The ebbing current steals away ; 
And red with Nature's flame they start 
From the warm fountains of the heart. 

29 No rest that throbbing slave may ask, 
Forever quivering o'er his task, 
While far and wide a crimson jet 

32 Leaps forth to fill the woven net. 
Which in unnumbered crossing tides 
The flood of burning life divides ; 
Then kindling each decaying part. 
Creeps back to find the throbbing heart. 

But, warmed with that unchanging flame, 
Behold the outward moving frame ; 
2 Its living marbles jointed strong 

With glistening band and silvery thong, 
16 And linked to reason's guiding reins 
By myriad rings in trembling chains. 
Each graven with the threaded zone 
Which claims it as the Master's own. 

See how yon beam of seeming white 
Is braided out of seven-hued light ; 
66 Yet in those lucid globes no ray 
By any chance shall break astray. 



THE CARE OF THE HEALTH 167 

Hark how the rolling surge of sound, 
70 Arches and spirals circling round, 

Wakes the hushed spirit through thine ear 
With music it is heaven to hear. 

17 Mark then the cloven sphere that holds 
All thought in its mysterious folds ; 
That feels sensation's faintest thrill. 
And flashes forth the sovereign will ; 
Think on the stormy world that dwells 
Locked in its dim and clustering cells ! 
The lightning gleams of power it sheds 

18 Along its hollow, glassy threads ! 

O Father ! grant thy love divine 
To make these mystic temples thine ! 
When wasting age and weary strife 
Have sapped the leaning walls of life, 
When darkness gathers over all. 
And the last tottering pillars fall. 
Take the poor dust thy mercy warms, 
And mold it into heavenly forms. 

— Oliver Wendell Holmes. 



From " The Autocrat of the Breakfast Table," by permission of Houghton, 
Mifflin & Company. The numbers refer to pictures in this book. 



APPENDIX 



NATURE STUDY 
I. Animals 

The Grasshopper, or Locust. — Examine one of these 
insects. You will see that the body is in three principal 
parts : head, chest, and ab- 
domen. Which part is made ^^ ^raiS '"^^^*' 
of rings.' How many legs 
has the grasshopper .' Which 
is the largest? The small- 
est .' Why cannot this in- 
sect run fast .' 

The grasshopper is called 
an insect because it has six legs and three principal parts 
in its body. Define an insect. How many parts are there 
in a grasshopper's leg .' The feet have four parts. Watch 
a grasshopper and find how it jumps, flies, and eats. How 
many wings has it } Which wings are long and slender ? 
The wings of which pair are folded like a fan .' The 
grasshopper belongs to the family of fan wings. Other 
fan wing insects are crickets, katydids, and devil horses. 
Insects breathe through little holes in the side of the body. 





Fig. 74. 



Can you find these holes in the grasshopper.' Do you 
know where grasshoppers lay their eggs .■' Did you ever 
see one shed its skin, or moult ? 



t7o 



APPENDIX 





Fig. 76. 



Fig. 77. 



TOPIC. 


INSECT. 


SPIDER. 


Body. 


Three parts. 


Two parts, 


Rings. 


Plain. 


Hidden. 


Skin. 


Hard ; shed only in sev^^al 


Soft and leathery ; shed at in- 




stages. 


tervals during life. 


Legs. 


Three pairs ; each made up of 


Four pairs ; each made up of 




five joints. 


seven joints. 


Eyes. 


Two compound, two or three 


All simple ; two to twelve. 




simple. 


usually eight. 


Wings. 


Two pairs or less. 


None. 


Feelers. 


True feelers. 


Foot-jaws, with fangs and tube 
leading to poison-glands. 


Spinning. 


Not at all; or only in grub 


Through spinnerets ; webs for 




stage. Thread comes through 


traps and cocoons for egg- 




mouth. 


cases. 


Breathing. 


By air-tubes. 


By sacs under body. 


Development. 


Egg, grub, pupa, and perfect 


Egg hatches and little spiders 




stage. 


moult as they grow. 



Compare the Moth and the Butterfly. See Figs. 62, 
78, 79, 80. 




Imva pwpa imago. 

Fig. 78. Fig. 79. 

The Stages in a Butterfly's Life. 



Fig. 80. 



PARTS. 


MOTH (CANDLE FLY). 


BUTTERFLY. 


Body. 


Large. 


Slender. 


Sliiu. 


Scales abundant. 


Scales fewer. 


Wings. 


Horizontal when at rest. 


Vertical when at rest. 


Feelers. 


Usually feathery or branching. 


Usually club-shaped. 


Habits. 


Night flyer. 


Day flyer. 



NATURE STUDY 



171 



Caterpillar. — See Figs. 62 and 78. How many legs are 
on front part of body .' On hind part .' How do the legs 
differ? Which are only thick folds of the skin.' Are 
there hooks on the ends of the fleshy feet? What do 




OKUB CHRYSALIS 

Fig. 81. — Common Ant. 

divisions of body look like ? How many rings are there ? 
Notice mouth ; jaws. Some caterpillars make brown 
cases; others make silk cases called cocoons, snug and 
warm; some produce moths, others butterflies. 




DRONe 

Fig. 82. — Bees. 

Comparison of the Cow and the Horse. — Your teacher 
will probably have you write the following topics on the 
board in one column, and " Cow " and " Horse," respec- 
tively at the head of two blank columns, and then fill out 
a few topics the first day, fiUing out the others after you 
shall have made observations on the two animals: 

Horns, toes, gait, lying down, rising, mane, end of tail, 
use of tongue, use of lips, teeth, stomach, cud, use of nos- 
trils, means of defense, sweat, warts, motion of ears, 



172 



APPENDIX 






ivi. 83. Fig. 84. Fig. 85. 

tongue, shape of head, voice, ears (shape and use), length 
of life, eating, breathing, position in sleeping. 

Compare the dog and the cat, the jay bird and the hen, 
the hen and the cat, etc. 




Fig. 86. — Claw of Cat. 
Showing the ligament that holds the claw up and the tendon that draws it down. 



The Cat — The head of the cat is 
89.) The ears are and can be 



and 



(Fig. 



when the animal 



is in pursuit of prey. The sense of hearing is very acute. 
The eyes are ; the pupils are and can be expanded 




Fig. 87. — Lion. 





Tiger. 



Fig. 89. — Head 
of Cat. 



SO that they can see as well by night as by day. The 

tongue is rough, being covered with sharp turned 

. Its roughness enables the cat to from . 

Feelers, or whiskers, grow on each side of the nostrils ; by 
these the cat can tell whether . The neck is , 



NATURE STUDY 



173 



the body , and the hind legs than the fore legs. 

There are toes on each front foot, and on each 

hind foot. The toes are . There are naked pads on 

the ball of the foot, and under each . The nails or 

claws are , , and . (Fig. 86.) The cat attacks 

by . When wild, it does not live in packs, like wolves, 

but has a definite home or lair. Therefore it is more at- 
tached to than to . The cat drinks by , 



turning the tip of the tongue 



Find out how many 



teeth the cat has. What is their shape 1 Why are four of 
the teeth very long .' 

{Note to the teacher. The different ways in which the pupil may 
answer the questions in the foregoing and the following outlines are 
given in the author's " Socratic Lessons in Science," a teachers' guide 
for two hundred oral lessons ; price 50 cents. Southern Publishing 
Company, Huntsville, Texas.) 

The Dispositions of Animals. — Name an animal that is — 



skillful 

patient 

imitative 

obedient 

faithful 



restless 

gentle 

neat 

intelligent 

self-denying 



persevermg 

watchful 

teachable 

affectionate 

treacherous 



The Movements of Animals. — Name an animal that — 



creeps 

swims forward 
swims backward 
walks on two feet 
walks erect on two feet 
walks on sole of foot 



walks on toes 
jumps 
flies swiftly 
flies noiselessly 
flies by day 
flies by night 



crawls 

dives 

hops 

scratches 

climbs 

burrows 



The following hsts, while being studied, should be written 
in columns on the blackboard, like the two lists above, and 
the names of the animals written after the Usts : 



i;4 



APPENDIX 



Instinct. — Name an animal that feigns hurt; feigns 
death; places sentinels; knows direction; is weather- 
wise; builds a home; seeks water when hatched; mi- 
grates; goes into winter quarters. 

Voice and Language. — Name animals that quack ; war- 
ble ; gobble ; trill ; whistle ; peep ; coo ; hoot ; twitter ; 
drum; caw; chirp; pipe; chatter; sing; whir; flutter; chir- 
rup ; buzz ; hum ; grunt ; bleat ; croak ; hiss ; roar ; click ; 
trumpet ; moo ; low ; bellow ; squeal ; bray. When does 
a hen cackle, cluck, chuckle, croon, give sound of remon- 






Squirrel, 



Boar. 



Hog. 



strance, of warning .' When does a horse neigh, whinny, 
snort .■" When does a dog bark, snarl, whine, yelp, growl, 
howl.-" When does a cat pur, mew, spit, squeal. 

Sociability. — Name an animal that is solitary; that is 
social — in feeling; in defense; in work; in play; in using 
voice ; in migration ; in hibernation ; that builds home ; 
mates for life ; cares for young ; trains the young. 

Escape. — Name an animal that escapes because of its 
color; shape; hard shell (see Fig. 90); bad odor; swift- 
ness ; that escapes into holes. 

Tongue. — Name an animal whose tongue is fleshy ; 
horny ; forked ; fastened in front ; that has a coiled 
"tongue." What animal uses its tongue for lapping; 
scraping bones ; taking in food ; catching prey. 

Jaws and Teeth. — Name an animal that swallows its 
food whole ; has a large mouth ; moves its jaws up and 
down ; moves jaws from side to side ; chews cud. Name 
an animal that catches prey with its teeth; gnaws; has 



NATURE STUDY 1 75 

pointed teeth ; has grinding teeth ; has three kinds of 

teeth ; has huge tusks for digging, or for use as crowbar. 
Name animals having the features referred to below : 
Eyes. — None ; many ; buried ; on stalks and movable ; 

that can see in dark ; keen ; simple and compound ; with 

narrow pupils. 

Limbs. — Legs: many, six, ten, eight, four, two, none. 

Toes: one, two, four, five; five in front and four behind; 




Fig. go. 

five in front and five behind ; webbed. Claws : none, 
blunt, sharp, retractile. Hoofs: cushioned, blunt, pointed. 
Wings: four, two, long, gauzy, scaly, hard. 

Homes. — Burrows ; wells ; traps ; galleries ; holes ; 
cocoons ; galls (balls on stems or leaves) ; wax cells ; 
mud cells; dams; in tree tops; nests (in sand, on crags, 
in trees, on the ground, in hollows ; made of mud, coarse 
sticks, down, strings). 

Eggs. — Covered by hard shell ; by skins. Round ; 
oval. Deserted by mother ; carried by mother. Hatched 
by setting; by sun. Laid in other nests; in masses; in 
the water ; in the earth ; on food for young ; in food for 
young. 

Food. — Name an animal that eats roots ; bark and 
twigs; grass and herbs; fruit and seeds; decayed wood; 
insects ; fish ; small animals and birds ; both animal and 



176 



APPENDIX 



vegetable food ; carrion ; juices of plants ; blood of ani- 
mals; nectar of flowers. 

The Elephant. — Size and strength compared with size 
and strength of other animals. Ears : shape and position. 
(See Fig. 72.) Size of eyes. State facts about skin, 
proboscis, tusks. What is the shape of the legs } Why .' 
Where have you seen ivory ? 




Fig. 91. 
Birds. (To be drawn.) 



Migrations. — The pupils may fill out three columns on 
the blackboard in an unused corner, taking several months 
in spring or fall for the work. First column, birds that stay 
all the year. Second column, birds that come from the 
south and are here in summer only. Third column, birds 
that come from the north and are here in winter only. 

Haunts. — Name some birds that are found most often in 
the following locahties : about our homes, in gardens and 
orchards, fields and meadows, in bushes, in the woods, in 
secluded woods, around streams of water, in thickets, in 
pine woods. 



NATURE STUDY 1 77 

II. Plants 

Seed Travelers. — Why do seeds need to travel .' Find 
various kinds of seeds and study how they travel. Find 
seeds that steal rides and return no benefit; seeds that 
ride and pay their way; seeds that fly; seeds that jump ; 
seeds that float. 

Twigs. — Get a twig of hickory (or other tree with large 
buds), a foot in length. Notice carefully : (i) The bark 
(color, toughness, rough or smooth). (2) The leaf scars 
(shape, size, position of dots, marking where there were 
woody fibers in the leaf stalk). Are leaves all of same 
size.' {^ Position of scars. Distance apart ? How many 




Fig. 92. 

A Daisy blossom is made of many little blossoms. 

do you find in going around the stem once 1 Why are 
some leaves out of line.' (4) A ring of narrow scars 
around stem in one or more places, showing the begin- 
ning of a year's growth. Appearance of bark above and 
below this ring } How many inches of growth were there 
last summer.' Summer before last.' How old is twig.' 
In what ways can you prove this.' (See rings of wood 
shown at end of stem.) 

Parts of a Flower. — Study a fully opened flower. 
What flower is it .' What colors do you see in it .' 



178 



APPENDIX 



Where is the green part ? This part holds the rest of the 

flower in it, so it is called the flower cup, or calyx. 

How many colored parts has it? These parts are 

called the flower leaves, or petals. What do the parts 
in the center look like.' Count the 
threadlike parts. Are they all alike ? 
Are there one or more different from 
the others.' What kind of end has 
this oiie.' What is on the ends of 
the others.' (Little heads, with yel- 
low powder on them.) This yellow 
powder is called pollen, and the parts 
that bear it are called pollen-threads, 
or starhens. The thread in the center 
is called the seed-thread, or pistil, 
because the seed-box, or ovary, is at 
the bottom of it. The pollen feeds 
the little seeds, or ovules, that they 
may grow into perfect seeds. 

Divisions of the Flower Parts. — 
(i) Calyx — sepals. (2) Corolla — 
petals. (3) Stamens — filament (stem), 
anther (usually two-celled), and pollen 
(dustlike). (4) Pistil — stigma (raw 

upper end), style (stem), and ovary (seed-case). 

Comparison of Two Flowers. — Compare rose and lily, 

rose and pink, rose and peach, jessimine and morning 

glory, etc. What are the differences in the cups (length, 

color, etc.).' In the flower leaves (number, color, etc.)? 

In the pollen-threads (number, shape of seeds)? In the 

seed-threads ? 

Cotton (see Fig. 65). — Do you know plants that have 

hairs on their stems? On their leaves? What is cotton? 

Do you know other plants that have a similar growth ? 

How many cells are there in a seed-vessel or ball ? How 




Fig. 93. 

The Dandelion is in the 
daisy, or sunflower, family. 



NATURE STUDY 



179 




many seeds in a cell ? As it ripens, what causes the boll to 
split open ? (The pod of cotton.) What is the cotton for ? 
(To enable the plant to „^„r,^^^ 

spread to new places ; the 
wind blows the seeds along 
the ground or through the 
air.) The hairs of the cot- 
ton plant are long tubes, 
flattened like tiny ribbons, 
thickened at the edges, 
with veinlike markings in 
the center. In drying, 
they twist. Other exam- 
ples of this among plants 
(pea-pods, etc.). Why is 
this of value in spinning 
threads .'' (The fibers take 

hold of one another. Thus the strength of the cotton is 
increased. This quality of the cotton fibers allows them to 
stretch and makes the thread elastic.) What other qualities 
increase the value of cotton fiber for spinning } (Its length 
and fineness.) The fibers, of the best cotton are from one 
and a half to two inches in length, and so fine that ten 
thousand placed side by side cover only half an inch. This 
" long staple " is used for making the finest muslin and laces, 
and sewing-thread. (Grown on sea islands on Georgia and 



Fig. 94." 

The Pea and the Bean have five petals in a 
blossom. Name them. Find other blos- 
soms like this. 




Carolina coast, in southern Texas, in Queensland (see map), 
and in Egypt.) "Short staple" is from one fourth to three 
fourths of an inch long, and is used for coarse goods. In 



l80 APPENDIX 

Mexico and India, a cotton plant grows for several years, 
becoming treelike in form and fifteen feet in height. Do 
you know any plant that has a flower like the cotton plant, 
with the threadlike parts united in a column in the center ? 
(Hollyhock, okra, mallow.) 

Shapes of Leaves. — Which leaf in Fig. 95 resembles the 
egg in outline, or is egg-shaped ?' Which is heart-shaped 1 
Oval ? Wedge-shaped ? Arrow-shaped .' Round .' Lance- 
like } Needlelike .' Can you find leaves on plants re- 
sembling each of the shapes named ? 

Parts of a Leaf. — Get a large leaf and find the foot 
stalk, the blade, the edge, the tip, the base, the midrib, 
the branching veins. 

The Edges of Leaves. — In Fig. 95 find a leaf with a 
smooth edge, toothlike edge, sawlike edge, wavy edge, and 
scalloped edge. 

Collection of Leaves. — Let the pupils find which of them 
can make the largest collection of leaves, keeping the leaves 
in an old book and learning the names of the plants whence 
they came. 

Contest. — To see who can find the greatest number of 
things in the following list before other pupils find them. 
They are to be found as they form in the spring and 
placed on the teacher's desk in the morning, with name 
attached. Pine cone. Sweet gum ball. Acorn. Hickory 
nut. Sycamore ball. Elder key. Maple key. Persim- 
mon blossom. Elm seed. Wild cherry. Fig blossom. 
Cedar seed. Keep the record on the blackboard. 



List 



Date Found 



Name of Finder 



Pine cone. 

Sweet gum ball, etc. 



NASAL BONES' 



^, 3^-THE CRANIUM. 

t-MALAR(cHEEK)aONC. 
[r"--SUPERIOR MAXILLARY BONES 
f-iNFERIOR MAXILLARY BONE 
'-■SPIMAL COLUMN. CEBVICAL REeiON. 



--CLAOiCLE(COLlAR BONE) 



SHOULDER BlUDE 



HUMERUS 



.ULMA- 




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Containing chapters on the Physiography of the State, Agricultural Industries, 
Ranching, Fisheries, Railroads, Manufacturing, Mineral Resources, Political 
Divisions, Government, Education, and History. 



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